JP3496571B2 - Brake equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake system, and more particularly to a brake system including a booster and a master cylinder.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 10-152041 discloses
A conventional example of the braking device is described. This conventional example includes (a) a brake operation member such as a brake pedal,
(b) A booster that boosts the operating force of the brake operating member, and (c) a pressurizing piston that is moved forward by receiving the operating force of the booster are fitted in the housing in a liquid-tight and slidable manner. When combined, a pressurizing chamber is formed in front of the pressurizing piston, and a hydraulic pressure is generated in the pressurizing chamber by advancing the pressurizing piston, and (d) the pressurizing chamber in the master cylinder. If the brake that has a brake cylinder connected via a fluid passage to suppress wheel rotation and (e) the predetermined pressure increase start condition is satisfied, then the hydraulic pressure of the brake cylinder is higher than that when it is not satisfied. A braking device including a pressure increasing device for generating hydraulic pressure in the brake cylinder.

[0003]

SUMMARY OF THE INVENTION In this conventional example, a pressure booster is arranged in series with a booster. Therefore, in this conventional example, the master cylinder hydraulic pressure is set by focusing on the fact that the booster can be grasped as the second booster having a boosting function like the booster. It is conceivable to design to increase pressure at a pressure increase rate. When the pressure booster is designed in this way, the final ratio, which is the ratio of the brake cylinder hydraulic pressure to the brake operating force, is the booster ratio at which the booster boosts the brake operating force, and the booster increases the master cylinder hydraulic pressure. It is expressed as the product of the pressure increase rate and the pressure increase rate.

On the other hand, the booster has a tendency that its operating characteristic, that is, the input / output characteristic, fluctuates.
It is remarkable in the vacuum booster. As is well known, the vacuum booster can be operated by using a negative pressure source as a drive source, but it is relatively difficult to accurately control the negative pressure level of the negative pressure source to a constant value in a vehicle. Yes, and therefore the operating characteristics of the vacuum booster tend to fluctuate. Further, since the booster operating characteristic affects the hydraulic pressure change characteristic of the master cylinder, that is, the relationship between the brake operating force and the master cylinder hydraulic pressure, when the booster operating characteristic changes, the master cylinder hydraulic pressure change characteristic also changes. It will be.

When the pressure booster is designed to increase the master cylinder hydraulic pressure at the set pressure increase rate as described above, the hydraulic pressure change characteristic of the master cylinder changes due to the change of the booster operating characteristic. Then, the final ratio may deviate from the target ratio by a relatively large amount. This is because fluctuations in the operating characteristics of the booster are amplified by the pressure booster connected in series to the booster by multiplication of the set pressure boosting rate and then transmitted to the brake cylinder. Therefore, in this conventional example, there is a possibility that the brake operation feeling may be impaired due to fluctuations in the operating characteristics of the booster during operation of the pressure booster.

Against this background, the present invention provides
It is an object of the present invention to prevent the brake operation feeling from being impaired due to fluctuations in the operating characteristics of the booster during operation of the booster, and the following aspects are obtained by the present invention. Each aspect, like the claims,
Divide into sections, number each section, and enter the number in other sections as necessary. This is to facilitate understanding of some of the technical features described in the present specification and combinations thereof, and the technical features described in the present specification and combinations thereof are limited to the following aspects. Should not be construed as

(1) Brake operation member and its brake operation
The booster that boosts the operating force of the work piece, and the booster
The pressure piston that receives the operating force behind and moves forward
Be fitted in a substantially liquid-tight and slidable manner on the housing
The front pressurization chamber and the rear
Side pressurization chamber is formed, and the forward movement of the pressurization piston
A master cylinder that generates hydraulic pressure in the front pressure chamber
And a liquid passage in the front pressure chamber of the master cylinder.
It has a brake cylinder connected via
The brake to be suppressed and the predetermined boost start condition are met.
If it stands, it is possible to generate pressure in the rear pressure chamber.
If the boosting start condition is not satisfied,
The brake pressure is higher than the hydraulic pressure of the rake cylinder.
Brake device including a pressure increasing device for generating a pressure . this
In the braking system, the same pressure
The operating force of the booster and the hydraulic pressure generated by the pressure booster
And an actuation force based on
Means that the booster is placed in parallel with the booster
To do. Therefore, according to this brake device, the booth
The operating force of the pressure booster is added to the operating force of the
Since it is transmitted to the rake cylinder, the conventional brake
Unlike the device, even if the operating characteristics of the booster change,
Fluctuation is amplified by the pressure booster and multiplied by the brake system.
It is prevented from being transmitted to the Linda. Therefore, this
According to the rake device, due to the fluctuation of the booster operating characteristics
To prevent the brake operation feeling from being impaired
To be done. Furthermore, according to this brake device,
As shown in the figure, a pressure booster mainly for electrical control and a mechanical control
And the booster mainly composed of are arranged in parallel with each other.
Therefore, the pressure booster and the booster cannot be operated at the same time.
Unless they fall into either the booster or booster
That boosting effect can be enjoyed in the master cylinder. Shi
Therefore, according to this brake device, the pressure booster is
As a device with parallel redundancy for the star
Associated with those boosters and boosters
Brake system tolerance to failure or failure
Tolerance is improved. In this braking device,
Is a vacuum booster driven by a negative pressure source.
Or use a hydraulic booster with a high-pressure source as the drive source.
Is possible. In addition, in this brake device
Is housed in the pressurization chamber to generate pressure.
The pressure medium, which is a fluid, can be a liquid or a gas.
May be. (2) When the pressure boosting device does not meet the pressure boosting start condition.
In this case, the pressure was not generated in the rear pressurizing chamber and it was established.
In this case, the breaker described in item (1) is generated.
Ki device. (3) The boosting start condition is set to the booster operating state.
If there is a possibility that the braking effectiveness will decrease
The booster is set so that
Suppresses the decrease in braking effectiveness due to the operating state.
Brake device described in paragraph (1) or (2)
Setting . According to this brake device, pressurization of the master cylinder
Intensifier of the type that pressurizes the piston behind it.
Causes the braking effect to increase due to the operating state of the booster.
Is suppressed. This brake device smells
For example, the booster start condition is that the booster reaches the limit of assistance.
It is set so that it will be established according to what is reached, and
The pressure booster controls the braking force characteristics.
It is possible to perform sex control. In addition,
"Pressure start condition" is established in response to booster failure
So that the booster is
Boots that suppress the decrease in booster effectiveness due to
It is also possible to perform control at the time of star failure. Na
Note that the "pressure increase start condition" described in (1) or (2) above is
For example, wheels are provided on the left and right sides of the vehicle,
The brakes are installed on the left and right wheels respectively.
Plan to reduce the running stability of the vehicle
Yaw Maume to reduce the outside yawing moment
Left and right because it is necessary to generate
Generated by the left and right wheels by the brake
If it is necessary to make the braking forces different,
Stand so that the pressure booster is
Perform vehicle stability control to control driving stability
It is possible. In addition, the "pressure increase start condition"
Applicable when the operating speed of the operating member is higher than the reference value.
So that the pressure booster is
Brake Assist to assist the brake operation force during operation
It is also possible to carry out control. (4) The booster is a vacuum driven by a negative pressure source.
A booster, the pressure boosting device being the vacuum boot
Effect of the brakes due to the
It suppresses the deterioration of the texture as described in item (3).
Brake device . According to this brake device, the master
Type of pressurizing the pressure piston of the cylinder behind it
Booster reaches maximum vacuum booster
The decrease in the braking effectiveness due to (5) The negative pressure source has a characteristic that the height of the negative pressure fluctuates.
That the vacuum booster has
Operation of the brake operating member when the assist limit is reached
The amount of the assist limit operating force that the force takes is the negative pressure of the negative pressure source.
It depends on the height, and the pressure increase start condition
However, the actual value of the negative pressure of the negative pressure source is within the fluctuation expected range of it.
If the vacuum is assumed to be equal to the lower limit of
The boost limit operation when the booster reaches the boost limit
Force when the operating force of the brake operating member reaches the force.
Brake device according to item (4) set to stand up
[Claim 1 ]. In this braking device, the brake
The operating force of the operating member changes the actual value of the negative pressure of the negative pressure source.
If it is assumed that it is equal to the lower limit of the
Relief limit when the cum booster reaches the relief limit
Actuation of the pressure booster when the operating force is reached (pressure boost control)
Is started. Therefore, with this brake device
For example, if the vacuum booster has reached the support limit?
Avoid the inconvenience that the booster cannot be activated
You can This brake system is used to reduce the actual negative pressure of the negative pressure source.
Or a physical quantity that changes accordingly is detected by a sensor.
By doing so, it is possible to determine whether or not the pressure increase start condition is satisfied.
Or the actual value of the negative pressure of the negative pressure source or a physical quantity corresponding to it
Is not detected by the sensor, but other physical quantities, namely
Sensor can detect the negative pressure of the negative pressure source more easily than the actual value
Increases pressure by detecting various physical quantities with a sensor
It is possible to adopt a mode in which the success or failure of the condition is determined. The former
When adopting the mode, the brake described in the item (2) above.
In this equipment, the pressure increase start condition is described in this section.
It seems that you do not need to set it, but detection of physical quantity
The detection characteristics of the sensor required for
Therefore, even in the former mode, the pressure increase start condition is
It is desirable to set it as described in
Yes. In the braking device described in this section, the negative pressure source
When the actual value of pressure fluctuates, the magnitude of the assist limit operating force fluctuates
However, this means that the operating characteristics of the vacuum booster vary.
Means to do. On the other hand, in this brake device
Is the actual operating pressure of the brake operating member, which is the negative pressure of the negative pressure source.
Assume value equals lower bound of its expected range of variation
When the limit operation force of the booster is reached, the booster
Since the operation is started, the actual value of the negative pressure of the negative pressure source is below that.
Pressure increase control not necessary when the limit value is not met
However, it will be done in parallel with the booster assistance. This
When using this brake device like
Due to variations in the operating characteristics of the
Actual value of Linda hydraulic pressure may be higher than target value
There is a nature. However, in this braking device
As mentioned above, even if the operating characteristics of the booster change,
The fluctuation is amplified by the pressure booster by multiplication and braked.
It is not transmitted to the cylinder. Therefore, this
The rake device allows vacuum boosters to reach the limit of assistance.
If the pressure booster cannot be activated despite reaching
The problem is that the actual value of the brake cylinder hydraulic pressure is the target value.
Brake operation feeling is impaired due to higher height
It can be avoided while suppressing the situation that (6) The master cylinder is installed in the housing.
Two pressure pistons are arranged in series with each other, which
The two front pressure chambers are formed in series with each other.
Brake device according to any one of (1) to (5)
Requirement Two ]. In the conventional braking device described above,
Two pressurizing pistons are arranged in series with each other
If the master cylinder is configured to
Pressure boosters will be installed downstream of the pressurizing chambers.
It On the other hand, in this conventional braking device,
During operation of the storage unit, the two pressure chambers corresponding to the two pressure chambers
It is desirable that the rake cylinders have equal hydraulic pressures.
Good Therefore, when operating the two pressure boosters,
The hydraulic pressure of the brake cylinders will be equal to each other.
Pay special attention to the control of those two boosters.
And are needed. On the other hand, the brake described in this section
In the equipment, the high pressure generated in the rear pressure chamber
The hydraulic pressure in the two front pressurizing chambers is increased accordingly.
At that time, the heights of the hydraulic pressures of the two front pressurizing chambers are mutually equal.
Be equal to Therefore, with this brake device
If so, the hydraulic pressure becomes equal to each other between the two front pressure chambers.
Special attention should be paid to the control of the booster to ensure
And are no longer essential. Therefore, in this brake device
According to this, during operation of the booster,
It is easy to make the liquid pressures equal to each other.
(7) The pressure booster is (a) the operation of the brake operating member.
Brake that detects the amount of braking force related to force
Operation force related quantity sensor, and (b) electrically operated before
Generates pressure in the rear pressure chamber and controls its height.
Pressure control / control device, and (c) the brake operating force
Between the related amount and the target pressure to be generated in the rear pressure chamber
In accordance with a predetermined relationship between the
Brake operation force related detected by force related quantity sensor
A target pressure is determined according to the amount, and the determined target pressure is realized.
To control the pressure generation / control device as described above.
A roller according to any one of the items (1) to (6) including a roller.
Rake device [Claims Three ]. In this braking device
“Brake operating force-related quantity” is, for example,
The physical quantity in the upstream side of the pressure booster,
The operating force or stroke of the brake operating member.
Can be a physical quantity in the downstream part, eg
For example, the hydraulic pressure of the master cylinder or the brake cylinder
It can be set to liquid pressure. "Brake operation force related
"Volume" is a pressure booster because of the design of the control theory of booster control.
Physical quantity on the upstream side of the storage device, that is, the influence of the booster
The physical quantity on the upstream side and the lower physical quantity should be selected.
A certain relationship is established with the physical quantity on the flow side, and that relationship
Replaces the physical quantity on the upstream side with the physical quantity on the downstream side.
It is possible to do so. (8) The rear pressure chamber contains a working fluid as a pressure medium.
The pressure generation / control device is in a non-operating state.
Then, the inflow and outflow of the hydraulic fluid into the rear pressure chamber.
In the operating state, it is at least activated.
It switches to a state that prevents the outflow of liquid (7).
Brake device described in. The brake operating member operates it
When operated in the direction of increasing force, the volume of the rear pressure chamber
When the operation force increases, while the operation force decreases,
The volume of the rear pressure chamber is reduced. Therefore, this backward pressure
Increase pressure control when non-compressible hydraulic fluid is stored in the chamber
During normal operation, the flow of hydraulic fluid to the rear pressure chamber is
Allows inflow and outflow, while applying back pressure during boost control.
It is necessary to prevent hydraulic fluid from flowing out of the pressure chamber.
Become. On the other hand, the brake device described in this section
The pressure generator / control device is
A condition that allows the inflow and outflow of hydraulic fluid to the pressure chamber
Yes, in working condition, at least block outflow of hydraulic fluid
Switch to the state that Therefore, in this brake device
According to this, electric energy is normally supplied to the pressure generation / control device.
If you deactivate it without supplying it, it will automatically
Inflow and outflow of hydraulic fluid to and from the pressurizing chamber is allowed, and
As a result, operation of the brake operating member in both directions is permitted.
On the other hand, during pressure increase control, the pressure generator
If Rugi is supplied and put into operation,
Hydraulic fluid is prevented from flowing out of the
The pressurizing chamber can be pressurized. (9) The pressure booster is provided in the rear pressure chamber on the discharge side.
By using the connected hydraulic pump, the rear pressure chamber
To generate pressure on any of (1) to (8)
Brake device described therein. (10) The pressure booster does not use an accumulator.
The hydraulic pressure port connected to the rear pressure chamber on the discharge side.
Pump to generate pressure in the rear pressure chamber.
The blur described in any of paragraphs (1) to (8).
Key device [Claims Four ]. According to this braking device,
Accumulator to generate pressure in the pressure chamber.
Since it is not necessary to provide a regulator, a compact pressure booster
The weight can be easily reduced. In this braking device
The "hydraulic pump" is a pump that has a high sealability against pressure medium.
A runner type or a gear type with a small discharge pressure pulsation
You can (11) The front pressure chamber and the brake cylinder are the
When the hydraulic pump is operating, the front pressure chamber and the brake system are
The Linda and the Linda are connected without interruption
Brake device according to (9) or (10) 5 ].
In this braking device, the pulsation of the hydraulic pump is
It is transmitted to the pressure piston of the master cylinder through the pressure chamber.
However, when operating the hydraulic pump, the front pressure chamber and brake
Pressure piston
The pulsation transmitted to the valve is passed through the front pressurizing chamber and the liquid passage to the pulsation.
It is transmitted to the rake cylinder. This brake cylinder
, Its pressurizing chamber has a damping effect. According to
With this brake device, the pulsation of the hydraulic pump is blocked.
Absorbed by the rake cylinder, resulting in a hydraulic pump
Transmission of brake pulsation to the brake operating member is suppressed.
Therefore, the deterioration of the brake operation feeling is suppressed. (12) The liquid passage is opened and closed intermittently.
A pressure control valve for controlling the pressure of the brake cylinder
Is provided, but with the master cylinder of the liquid passage
Install a brake cylinder between the pressure control valve and
A cut valve that continuously cuts from the star cylinder is not provided.
The brake device according to the item (11) that does not exist. This bu
According to the rake device, one state of the brake device described in the preceding paragraph.
Is obtained. (13) The pressure generation / control device is controlled by (a) the housing.
The piston is fitted in a substantially liquid-tight and slidable manner
Creates a control pressure chamber in front of the control piston.
The forward movement of the control piston causes pressure in the control pressure chamber.
Is a pressurizing device that generates
Connected to the rear pressure chamber, and (b) the electric motor.
(C) The rotational movement of the electric motor is controlled by the control piston.
A motion conversion mechanism for converting the motion into a linear motion of
Controlling the stroke by controlling the piston
Including a controller that controls the pressure level of the pressure chamber (7)
Or the braking device according to the item (8). This braking device
According to the comparatively simple structure,
Generates pressure in the rear pressure chamber and controls its height
You can do both. In this braking device
For example, a “motion conversion mechanism” is capable of linear motion but
Male screw that cannot be rolled and linear motion that can be rotated
It has a configuration in which a nut that is not
The electric motor to rotate it in the forward or reverse direction.
To move the control piston forward or
It may be in a mode of moving backward. However,
The roles of screws and nuts are interchangeable. (14) The rear pressure chamber stores the working fluid as the pressure medium.
And the pressure booster is further
A pressurizing device including a reservoir for containing a liquid;
Formed on the housing, the control piston is in the initial position
Is in communication with the control pressure chamber when
When it is in the position advanced from
Control port that is shut off from the control pressure chamber
A pressure chamber is connected to the reservoir at its control port
The braking device according to item (13). In this braking device
The relative movement between the control piston and the control port.
Therefore, it is possible to increase the pressure in the control pressure chamber during pressure increase control.
On the other hand, at normal times when pressure boosting control is not performed, the control pressure chamber
Connect the hydraulic fluid to the reservoir so that it can flow in both the forward and reverse directions.
Passed through. Therefore, with this brake device
For example, with the same pressurizing device, the pressure
To generate pressure on and control its height
During normal operation, the control pressure chamber allows the reservoir and master
Hydraulic fluid flows in both directions in the rear pressure chamber of the cylinder.
By communicating with each other so that they can communicate, the brake
Allowing the volume change of the rear pressure chamber according to the operation
Both can be done, and the whole pressure booster configuration can be easily simplified.
It (15) The rear pressure chamber contains the working fluid as a pressure medium.
The pressure booster further comprises (a) the operation
A reservoir for containing a liquid, and (b) the pressure generation / control device
Is a bypass passage that bypasses the
On the side of the rear pressure chamber, the other end of the reservoir
(C) in the middle of its bypass passage
Provided from the reservoir toward the rear pressure chamber.
While always permitting the flow of moving fluid,
(7) to (14) including a check valve
Brake device described in. According to this braking device,
From the server to the rear pressure chamber in the master cylinder
Without the flow of hydraulic fluid passing through the pressure generation / control device
Since it is always allowed, the brake operating member has its operating force.
The back of the reservoir when operated quickly in an increasing
Working fluid into the pressure chamber
It can be supplied through both the route passing through the check valve.
Therefore, according to this brake device,
The amount of hydraulic fluid replenished to the rear pressure chamber is related to the brake operation speed.
Negative pressure is generated in the rear pressure chamber due to the failure to comply.
Is suppressed. (16) The rear pressure chamber contains the working fluid as a pressure medium.
The pressure booster further comprises (a) the front
A communication passage that connects the pressure chamber and the rear pressure chamber to each other
(B) The communication passage is opened in the middle of the communication passage.
An on-off valve that can be electromagnetically switched between closed and closed states
(C) The rear pressure chamber is controlled by the pressure generation / control device.
If pressure cannot be generated on the
Open the valve, and if possible, close it.
A roller according to any one of the items (7) to (15).
Rake equipment. According to this brake device,
Pressure can be used to generate pressure in the rear pressure chamber
It becomes Noh. On the other hand, even if the pressure generation / control device fails,
The brake operation member will move forward unless the
Pressure can be generated in the pressurizing chamber. Therefore, this blur
According to the brake device, even if the pressure generation / control device fails,
Pressure may be generated in the rear pressure chamber. (17) The pressure booster further increases the liquid pressure in the front pressure chamber.
If it is less than the set value, the
Block the flow of hydraulic fluid to the pressure chamber,
Distribution control device that allows the flow
The braking device according to (16), which includes The blur described in the previous section
If the pressure boosting start condition is satisfied in the brake device, immediately
Open the on-off valve to transfer the pressure in the front pressure chamber to the rear pressure chamber.
As a result, the boosting action by the rear pressure chamber is realized.
In the case of
The hydraulic fluid in the chamber is not only applied to the brake cylinder but also to the rear pressure chamber.
Will also be discharged. This means that
At the beginning of establishment, that is, the hydraulic fluid in the front pressure chamber is brake
Increased brake cylinder fluid pressure even if discharged only to the Linda
Is there a tendency for the gradient to become slightly gentler when the boost start condition is met?
Stronger period of time after a rather long time
In addition, the pressure gradient of the brake cylinder hydraulic pressure becomes gentler.
It means that On the other hand, in this section
The hydraulic pressure of the front pressure chamber is set in the brake device
If it is less than or equal to the value, move from the front pressure chamber to the rear pressure chamber.
The flow of the working fluid is blocked. Therefore, this blur
According to the brake device, the hydraulic pressure in the front pressure chamber is used to apply rear pressure.
Despite having a pressure booster to pressurize the pressure chamber,
-Preventing a gentle increase in hydraulic cylinder pressure
This also gives a feeling of brake operation.
Is suppressed. In this braking device
In addition, the “flow control device” has a mode in which the on-off valve is used.
It is possible to adopt a mode in which it is not used or used. (18) The distribution control device is provided in the middle of the communication passage.
From the hydraulic pressure in the front pressure chamber to the hydraulic pressure in the rear pressure chamber.
When the subtracted differential pressure is less than the valve opening pressure that is not substantially 0
Flow of hydraulic fluid from the front pressure chamber to the rear pressure chamber.
If this is blocked and the differential pressure tries to become higher than the valve opening pressure, the
The brake according to paragraph (17), including a first check valve that allows the flow of
Key device. According to this brake device, the brake of the preceding paragraph is
The "distribution control device" in the rake device is
It can be realized with a relatively simple configuration without utilizing. (19) The pressure booster further includes (a) a valve for connecting the first check valve.
The bypass path that bypasses, and (b) the way of the bypass path.
It is provided inside, and the rear pressure is applied regardless of the height of the differential pressure.
Allow the flow of hydraulic fluid from the chamber to the front pressure chamber
On the other hand, a second check valve for blocking the flow in the opposite direction is included.
The braking device according to item (18). With this brake device
For example, the first reason is that hydraulic fluid may flow from the outside into the front pressure chamber.
Even if it is blocked by the check valve,
Therefore, since the inflow is allowed, the brake operating member
When it is quickly operated in the direction in which its operating force increases,
It is possible to supply hydraulic fluid to the front pressure chamber at a flow rate that follows it.
Negative pressure in the front pressure chamber due to quick brake operation.
Is suppressed. (20) The rear pressure chamber contains the working fluid as a pressure medium.
The pressure intensifier is (a) the front pressure chamber and
A communication passage for communicating the rear pressure chamber with each other;
Is provided in the middle of the communication passage of the
An on-off valve that can be electromagnetically switched to a twisting state, and (c)
If the above pressure increase start condition is satisfied, the open / close valve of
If it does not hold, the control to control the closed state
Including any one of (1) to (6)
Brake equipment. According to this brake device, front pressure is applied.
Pressure is generated in the rear pressurization chamber using the chamber pressure.
It On the other hand, unless the booster fails, the brake operation
It is possible to generate hydraulic pressure in the front pressure chamber by the operating force of the material.
It is possible. Therefore, according to this brake operation,
Master cylinder to generate pressure in the rear pressure chamber
It is no longer essential to use a separate source of pressure. This
Brake device of any of (17) to (19) above
It can be implemented with the described features. (21) The pressure booster uses the negative pressure source as a drive source to drive the rearward pressure.
Including a vacuum pump that generates pressure in the pressure chamber (1)
Brake device according to any of the items (20)
6 ]. The brake device described in the item (1) is a pressure increasing device.
However, by driving the hydraulic pump with an electric motor,
Can be implemented in a manner that generates pressure in the rear pressure chamber.
However, as compared with this embodiment, the brake device described in this section.
According to the above, it is not necessary to use an electric motor, and the negative pressure source is
In many cases, it can be configured in the vehicle without any special mechanism.
Due to reasons such as the fact that
Reduction, reduction of operating noise, improvement of reliability, etc. can be easily realized.
It (22) The booster uses a vacuum source that drives the negative pressure source.
The brake device according to item (21), which is a boom booster. this
According to the brake device, the drive source includes the booster and the booster.
Since it is common to all, the number of parts of the brake device can be reduced.
Therefore, the configuration of the entire brake device can be easily simplified. (23) The vacuum pump is (a) atmospheric pressure and the negative pressure source.
The transformer chamber where the negative pressure of the transformer is selectively introduced, and
It operates based on the pressure difference between the chamber and the atmospheric chamber that communicates with the atmosphere.
The plunger and (c)
A pump chamber whose volume can be reduced or increased.
(21) or (22) including those connected to the rear pressure chamber
Brake device described in. (24) The vacuum pump is further connected to the atmosphere and the negative pressure.
A three-way valve connected to a source and said transformer chamber,
The first state that shuts off the negative pressure source to communicate with the atmosphere,
The second state where the pressure chamber is cut off from the atmosphere and communicated with the negative pressure source
(21) to (23)
Brake device according to any one. With this brake device
In order to selectively introduce atmospheric pressure and negative pressure into the variable pressure chamber,
In addition, control valves are installed for introducing atmospheric pressure and for introducing negative pressure.
There is no need to open, and atmospheric pressure and negative pressure are selected for the transformer room.
Configuration for easy introduction and
The configuration of the entire pump is also simplified.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, some more specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a brake device according to a first embodiment of the present invention. This braking device is provided with left and right front wheels FL, FR and left and right rear wheels RL, RR.
It is installed in a wheeled vehicle. This brake device includes a brake pedal 10 as a brake operating member, and the brake pedal 10 is connected to a tandem type master cylinder 14 via a vacuum booster 12 (hereinafter, simply referred to as “booster”).

As is well known, the booster 12 includes a negative pressure chamber connected to an intake pipe of an engine as a negative pressure source, and a variable pressure chamber selectively connected to the negative pressure chamber and the atmosphere. By the operating force of the power piston that is operated based on the differential pressure of, the brake operating force, which is the depression force of the brake pedal 10, is boosted and transmitted to the master cylinder 14.
The negative pressure source has the characteristic that the height of its negative pressure varies.

In this booster 12, as the brake operating force increases, the pressure in the variable pressure chamber increases from a height equal to the pressure in the negative pressure chamber (changes toward the atmospheric pressure), and the booster 12 is kept in the meantime. Brake operation force can be assisted. However, the brake operating force cannot be assisted after the pressure in the negative pressure chamber becomes equal to the atmospheric pressure. As described above, the booster 12 has a limit of assistance. The magnitude of the assisting limit operating force, which is the brake operating force when the booster 12 reaches the assisting limit, fluctuates depending on the pressure of the negative pressure chamber, that is, the negative pressure of the negative pressure source. The larger the pressure (stronger negative pressure tendency), the larger the pressure, and the smaller the negative pressure (weak negative pressure tendency), the smaller the pressure.

The master cylinder 14 has a bottomed cylindrical housing 20. The housing 20 has a first
The third cylindrical holes 22, 24, and 26 are formed so that the diameter gradually decreases from the opening side of the housing 20 toward the bottom side thereof.

A sleeve 30 is fitted in the second cylindrical hole 24 in a substantially liquid-tight manner. Of the both ends of the sleeve 30, the end near the bottom of the housing 20 has a second cylindrical hole 2
4 and the third cylindrical hole 26 are brought into contact with the stepped surface. Further, the sleeve 30 is prevented from moving from a position in contact with the stepped surface by a fixing member such as a snap ring not shown. The first pressurizing piston 3 is inserted into the cylindrical hole 31 which is the inner peripheral surface of the sleeve 30.
2 and the second pressurizing piston 34 are fitted in series with each other. The two pressurizing pistons 32 and 34 both have a bottomed cylindrical shape and are fitted in the cylindrical hole 31 so as to be substantially liquid-tight and slidable. By this fitting, the front pressurizing chamber 3 is provided in front of each pressurizing piston 32, 34.
6, 38 are formed. Each pressurizing piston 32, 34
Are arranged in the housing 20 such that the inner surfaces of the bottoms of the pressurizing pistons 32 and 34 face the corresponding front pressurizing chambers 36 and 38. Each pressurizing piston 32, 34 is
The springs 40 and 42 as elastic members arranged in the corresponding front pressure chambers 36 and 38 are urged toward the retracted end position shown in the figure. First pressurizing piston 3
The initial length (extendable length) and the initial load of the spring 40 corresponding to 2 are defined by a member (not shown), and the retracting end position of the first pressurizing piston 32 is closed later. In cooperation with what is defined by the member 44, the retracted end position of the second pressure piston 34 is defined.

A closing member 44 is attached to the first cylindrical hole 22 so as to close the opening of the housing 20 in a substantially liquid-tight manner. The closing member 44 is provided on the first cylindrical surface 22.
By contacting the stepped surface between the second cylindrical surface 24 and the second cylindrical surface 24, the limit of approaching the bottom portion of the housing 20 is defined, while it can be separated from the housing 20 by a fixing member such as a snap ring (not shown). It has been blocked. The closing member 44 defines the retreat limit of the first pressurizing piston 32 by being brought into contact with the first pressurizing piston 32. An auxiliary piston 46 extends rearward from the rear end surface of the first pressurizing piston 32, and penetrates the closing member 44 in a liquid-tight manner and slidably and faces the booster 12. The master cylinder 14 is
The auxiliary piston 46 is designed to be operated by receiving the operating force of the power piston of the booster 12, and based on the operating force, the two front pressurizing chambers 36, 38 are operated.
To generate liquid pressures of equal height to each other.

By fitting the closing member 44 into the housing 20, the closing member 44 and the first pressurizing piston 3 are
A rear pressurizing chamber 50 is formed between the two. When pressure is generated in the rear pressurizing chamber 50, the first pressurizing piston 32 is pressurized in the forward direction, and thereby pressure is generated in the front pressurizing chamber 36. When the pressure is generated in the front pressurizing chamber 36, the second pressurizing piston 34 is pressurized in the forward direction, so that the pressure is also generated in the front pressurizing chamber 38.

The housing 20 is formed with two reservoir ports 52, one pressure increasing port 54 and two brake cylinder ports 56.

The two reservoir ports 52 connect the two front pressurizing chambers 36 and 38 to a reservoir 58 which contains the hydraulic fluid at atmospheric pressure. The two reservoir ports 52 are provided respectively corresponding to the two pressurizing pistons 32 and 34, and each reservoir port 52 has a communication passage 62 that radially penetrates the sleeve 30, and It is connected to the front pressurizing chambers 36 and 38 via the communicating passages 63 that radially pass through the cylindrical portions of the pressurizing pistons 32 and 34 at the retracted end positions shown in the figure. Each pressurizing piston 32,
When 34 is advanced a little from its retracted end position, each communication passage 63 becomes the communication passage 62 of the cylindrical hole 31 of the sleeve 30.
Ports for each reservoir 5
2 from each other, so that each front pressure chamber 36, 38
Can be boosted by advancing the pressurizing pistons 32 and 34.

One pressure increasing port 54 is provided in the housing 2
No. 0 is formed at a position that always communicates with the rear pressure chamber 50, and the rear pressure chamber 50 is communicated with the pressure booster 64. The pressure increasing device 64 is configured to include a gear type pressure increasing pump 66, a pump motor 68 that drives the pressure increasing pump 66, and a pressure control valve 70. The suction side of the pressure boosting pump 66 is connected to the reservoir 58, and the discharge side of the pressure boosting pump 66 is connected to the pressure boosting port 54.
As a result, the hydraulic fluid is pumped up from the reservoir 58 and pumped to the rear pressure chamber 50. A check valve 72 is provided on the discharge side of the pressure boosting pump 66 to prevent the hydraulic fluid from flowing back to the pressure boosting pump 66. The pressure booster 64 is further provided with a bypass passage 74 that bypasses the pressure boosting pump 66 and the pressure control valve 70 together, and in the middle of the bypass passage 74, from the reservoir 58 to the rear pressurization chamber 50.
A check valve 76 is provided that always allows the flow of hydraulic fluid toward the other side, while always blocking the flow in the opposite direction. Due to the existence of the check valve 76, the brake pedal 1
When 0 is rapidly depressed and the volume of the rear pressurizing chamber 50 is rapidly increased, the flow of the hydraulic fluid from the reservoir 58 to the rear pressurizing chamber 50 is not limited to the path passing through the pressure control valve 70, but also the check valve thereof. It is also realized by the route via 76. As a result, due to the quick brake operation, the rear pressure chamber 50
The negative pressure is suppressed from being generated.

The pressure control valve 70 is shown enlarged in FIG. The pressure control valve 70 is of a type that electromagnetically controls the hydraulic pressure in the rear pressurizing chamber 50. The pressure control valve 70 includes a housing (not shown), a valve 80 for controlling the flow state of the hydraulic fluid between the rear pressurizing chamber 50 and the reservoir 58, a valve seat 82 on which the valve 80 should be seated, the valve 80 and the valve 80. And a solenoid 84 that generates a magnetic force that controls the relative movement of the valve seat 82.

In this pressure control valve 70, when the solenoid 84 is not energized and is in a non-acting state (OFF state),
The elastic force of the spring 86 separates the valve element 80 from the valve seat 82, thereby allowing a bidirectional flow of hydraulic fluid between the rear pressure chamber 50 and the reservoir 58. As a result, when the brake operation is performed and the first pressurizing piston 32 is operated, and the volume of the rear pressurizing chamber 50 changes accordingly, inflow and outflow of the hydraulic fluid into and from the rear pressurizing chamber 50 is accompanied. Is acceptable. in this way,
Since the pressure control valve 70 is a normally open valve, it is not possible to perform a special operation for allowing the volume change of the rear pressurization chamber 50 on the pressure control valve 70 at a normal time when the pressure increase control is not performed. It is unnecessary.

On the other hand, in a working state (ON state) in which the solenoid 84 is excited, the armature 88 is attracted by the magnetic force of the solenoid 84, and the valve 80 is seated by the valve seat 82.
Seated in. At this time, in the valve 80, the solenoid attraction force F ₁ based on the magnetic force of the solenoid 84 and the sum of the force F ₂ based on the hydraulic pressure of the rear pressure chamber 50 and the elastic force F ₃ of the spring 86 are mutually. It works in the opposite direction. The magnitude of the force F ₂ is represented by the product of the hydraulic pressure in the rear pressurizing chamber 50 and the effective pressure receiving area where the valve 80 receives the hydraulic pressure in the rear pressurizing chamber 50.

The operating state in which the solenoid 84 is excited (O
(N state), the discharge pressure of the booster pump 66, that is, the hydraulic pressure of the rear pressurizing chamber 50 does not increase so much, and in the region where the relationship represented by the formula F ₂ ≦ F ₁ −F ₃ is established, The valve 80 is seated on the valve seat 82, the hydraulic fluid from the pressure boosting pump 66 is prevented from escaping to the reservoir 58, and the pressure boosting pump 66 is prevented.
The discharge pressure is increased, and hydraulic pressure is generated in the rear pressure chamber 50. On the other hand, the valve 80 is separated from the valve seat 82 in the region where the hydraulic pressure in the rear pressurizing chamber 50 is further increased and the relation expressed by the formula F ₂ > F ₁ −F ₃ is about to be established. The hydraulic fluid from the pressure increasing pump 66 is released to the reservoir 58, and as a result, the hydraulic pressure in the rear pressurizing chamber 50 is prevented from further increasing. In this way, if the elastic force F ₃ of the spring 86 is neglected in the rear pressurizing chamber 50, a hydraulic pressure that linearly increases according to the solenoid attraction force F ₁ is generated.

Further, the pressure control valve 70 is configured so that the magnitude of the solenoid attraction force F ₁ changes linearly according to the magnitude of the exciting current I of the solenoid 84, as shown in the graph of FIG. Is designed.

As shown in FIG. 1, the two brake cylinder ports 56 are formed in the housing 20 at positions which always communicate with the two front pressure chambers 36 and 38, respectively. Front pressure chamber 36, 38
Are respectively connected to two independent brake systems. The brake device is a front-rear two-system type, and one brake system has two brake cylinders 92 that operate two brakes 90 that respectively suppress the rotation of the left and right front wheels FL and FR, and the other brake system. The brake system of
Two brake cylinders 92 that operate two brakes 90 that respectively suppress the rotation of the left and right rear wheels RL and RR.
have. The brake systems will be described below. However, since the brake pressure systems have the same configuration, only the brake pressure systems related to the left front wheel FL and the right front wheel FR will be representatively described, and other brake pressure systems will be described. The description is omitted.

The front pressure chamber 36 of the master cylinder 14 is connected to a brake cylinder 92 for the left front wheel FL and a brake cylinder 92 for the right front wheel FR by a main passage 94.
The main passage 94 is branched into a bifurcated shape after extending from the front pressurizing chamber 36, and one main passage 96 and two branch passages 98, 98 are connected to each other. A brake cylinder 92 is connected to the tip of each branch passage 98. Master cylinder 14 in main passage 94
The pump passage 1 is provided between the brake cylinder 92 and the brake cylinder 92.
One end of 02 is connected. An ABS pump 104 is provided in the pump passage 102. Two ABS pumps 10 in two brake pressure systems
4, 104 are driven together by a pump motor 106 common to them.

In the middle of each branch passage 98, the pump passage 1
A holding valve 110, which is a normally open electromagnetic on-off valve, is provided on the brake cylinder 92 side from the connection point with 02. The holding valve 110 has its solenoid 112 (see FIG.
(See) is excited and closed, and in that state, ABS
The flow of the hydraulic fluid from the pump 104 for the brake cylinder 92 is blocked, so that the brake cylinder hydraulic pressure is maintained. A bypass passage 114 is connected to each holding valve 110, and a check valve 116 for returning hydraulic fluid is provided in each bypass passage 114.

From the portion of each branch passage 98 between the holding valve 110 and the brake cylinder 92, the reservoir passage 118 starts.
Extends to reach the reservoir 120. A pressure reducing valve 130, which is a normally closed electromagnetic on-off valve, is provided in the middle of each reservoir passage 118.
Is provided. The pressure reducing valve 130 is opened by exciting its solenoid 132 (see FIG. 4), and in this state, allows the flow of the hydraulic fluid from the brake cylinder 92 to the reservoir 120, whereby the brake cylinder fluid pressure is increased. Achieve a state of reduced pressure.

The reservoir 120 is constructed such that a reservoir piston 134 is fitted in a housing in a substantially liquid-tight and slidable manner, and the reservoir 120 is operated in a reservoir chamber 136 formed in front of the reservoir piston 134 by the fitting. The liquid is stored under pressure by a spring 138 as a biasing means. The reservoir chamber 136 is connected to the main passage 94 by the pump passage 102.

The pump passage 102 is an ABS pump 104.
Is divided into a suction passage 140 and a discharge passage 142, and a suction valve 144 and a discharge valve 146, both of which are check valves, are provided in the passages 140 and 142, respectively. The pump passage 102 further includes a damper chamber 148.
And the orifice 150 as a throttle are connected in series with each other.
It is provided on the discharge side of the S pump 104, so that the pulsation of the ABS pump 104 is reduced.

The mechanical structure of the brake device has been described above, and the electrical structure will be described next.

This braking device, as shown in FIG.
Electronic control unit (hereinafter abbreviated as "ECU") 2
It is equipped with 00. This ECU 200 is also a component of the pressure booster 60. The ECU 200 is mainly composed of a computer including a CPU, a ROM and a RAM, and the effectiveness characteristic control routine and the antilock control routine stored in the ROM are RAM by the CPU.
Is executed while using the above, the effective characteristic control and the antilock control are executed. "Effective property control" is
Considering that the booster 12 has an assist limit, both the brake operating force F and the vehicle body decelerating force G are increased so that the vehicle body deceleration G increases with the same gradient with respect to the brake operating force F, regardless of before and after the booster 12 assisting limit. Controlling the braking effectiveness characteristic that is related to the speed G. Also, as is well known, "anti-lock control" refers to controlling the brake cylinder hydraulic pressure of each wheel so that the locking tendency of each wheel does not become excessive during vehicle braking. In this embodiment, the hydraulic fluid is circulated in the brake circuit by the ABS pump 104 during the antilock control.

A brake operating force sensor 204 and a plurality of wheel speed sensors 208 are connected to the input side of the ECU 200. The brake operating force sensor 204 outputs a brake operating force signal that defines the brake operating force F. The wheel speed sensor 208 is provided for each wheel and outputs a wheel speed signal that defines the wheel speed of each wheel.

On the other hand, on the output side of the ECU 200, the solenoid 8 of the pressure control valve 70 is shared by the two brake systems.
4 and a pump motor 68 for driving the pressure increasing pump 66.
And a pump motor 106 for driving the two ABS pumps 104 are connected one by one. Further, for each brake system, the solenoid 112 of the holding valve 110,
The solenoid 132 of the pressure reducing valve 130 is connected.

FIG. 5 is a flowchart showing the effectiveness characteristic control routine. This routine will be described below.

This routine is repeatedly executed after the driver turns on the ignition switch (not shown) of the vehicle. At the time of execution of each time, first, in step S1 (hereinafter, simply represented by “S1”; the same applies to other steps), the current brake operating force F is detected. Specifically, first, a brake operating force signal is captured from the brake operating force sensor 204, and then the current brake operating force F is calculated based on the captured signal.

Next, at S2, it is judged if the calculated brake operating force F is higher than the reference value F _TH . It is determined whether or not it is necessary to increase the brake cylinder hydraulic pressure P _B by the pressure increasing pump 66 because the booster 12 has reached the assisting limit. Assuming that this is necessary this time, the determination is YES and S3
At, the pressure increase control is performed. In the present embodiment, when the reference value F _TH is assumed to be equal to the lower limit value (minimum negative pressure) of the negative pressure fluctuation expected range of the negative pressure source, the booster 12 reaches the assist limit. The brake operating force F is set as a value to be taken when reaching.

FIG. 6 is a flowchart showing details of the pressure increase control as a pressure increase control routine. First,
In S21, the target pressurization amount ΔP for pressurizing the rear pressurizing chamber 50 is determined based on the detected brake operating force F. The target pressurization amount ΔP increases with the same gradient as that before the booster 12 reaches the assist limit with respect to the brake operating force F when the vehicle deceleration G (corresponding to the brake cylinder hydraulic pressure P _B ). Master cylinder fluid pressure P _M
Is set to increase with respect to the brake operating force F. Here, the target pressurization amount ΔP is equal to the amount by which the master cylinder hydraulic pressure P _M is increased by the pressure increase control, and
It is also equal to the amount by which the brake cylinder hydraulic pressure P _B is increased by the pressure increase control. In the present embodiment, the relationship between the brake operation force F and the target pressurization amount ΔP is stored in the ROM, and the target pressurization amount ΔP corresponding to the current value of the brake operation force F is determined according to the relationship. FIG. 7 is a graph showing the relationship between the brake operating force F and the target pressurization amount ΔP.

Next, in S22, the determined target addition
The solenoid 84 of the pressure control valve 70 is provided according to the pressure amount ΔP.
Target current value I, which is the current value I to be supplied^*Is determined.
The relationship between the target pressurization amount ΔP and the solenoid current value I is ROM
Is stored in the target pressure amount ΔP according to the relationship.
Corresponding target current value I^*Is calculated. In Figure 8
Is a relation between the target pressurization amount ΔP and the solenoid current value I.
As an example, the target pressurization amount ΔP and the solenoid current value I are directly calculated.
Solenoid attraction force F instead of making contact ₁ Intermediary
As shown in FIG. Target pressurization
Amount ΔP and solenoid attraction force F₁ Relationship with the solenoid
Suction force F₁ And the relationship between the solenoid current value I and
It is shown.

Subsequently, in S23, the pressure control valve 70
The drive current is supplied to the solenoid 84 of the same amount as the determined target current value I ^* . Then, in S24, the pump motor 68 is signaled to turn it on. As a result, the first pressurizing piston 32 of the master cylinder 14 is pressurized by the pressure increasing pump 66 behind it, and as a result, the master cylinder hydraulic pressure P _M and the brake cylinder hydraulic pressure P _B are higher than those before the pressure increasing control. Target pressurization amount Δ
The pressure is increased by an amount equal to P. At this time, hydraulic pressure is generated in the four brake cylinders 92 at the same height between the left and right wheels. This completes one execution of the pressure increase control routine, and thus completes one execution of the effect characteristic control routine.

On the other hand, when the brake operating force F is not higher than the reference value F _TH , the determination in S2 of FIG. 5 is NO.
Then, the ending process is performed in S4.

FIG. 9 is a flowchart showing the details of the end processing as an end processing routine. First,
In S41, a signal for turning it off is output to the solenoid 84 of the pressure control valve 70. As a result, the pressure control valve 70 is returned to the open state. Next, in S42, a signal for turning it off is output to the pump motor 68. As a result, the boosting of the master cylinder hydraulic pressure by the boosting pump 66 is completed. With the above, one execution of the termination processing routine ends, and with this, one execution of the effect characteristic control routine also ends.

FIG. 10 is a graph showing an example of how the braking characteristic, that is, the relationship between the brake operating force F and the brake cylinder hydraulic pressure P _B is controlled by the braking characteristic control.

In the present embodiment, as described above, the booster 12 assists the brake operating force F in a state where the actual value of the negative pressure of the negative pressure source is the lower limit value in the fluctuation expected range thereof, that is, the minimum negative pressure. When the brake operating force F reaches a value that can be obtained when the limit is reached, the effectiveness characteristic control is started. Therefore, when the actual value of the negative pressure of the negative pressure source matches the minimum negative pressure, the actual effectiveness characteristic matches the target characteristic indicated by the chain double-dashed line in the figure. However, when the actual value of the negative pressure of the negative pressure source does not match the minimum negative pressure and is higher than that (when the negative pressure tendency is strong), the booster 12
When the booster 12 actually reaches the assisting limit and the timing when the effectiveness characteristic control is started do not coincide with each other, and before the booster 12 actually reaches the assisting limit, the effectiveness characteristic control which is not originally necessary is started. It will be. That is, there is a period in which the booster 12 assists and the boosting by the effect characteristic control overlaps. In this overlap period, the actual value of the brake cylinder hydraulic pressure P _B is the solid line and the broken line in FIG. As shown by, it becomes higher than the target characteristic.

The solid line graph shown by in the figure shows the effect of the braking characteristic control in the present embodiment, while the broken line graph shown by shows the pressure booster 60 and the master cylinder hydraulic pressure P _M at the set pressure boosting. As a comparative example, the effect of controlling the effectiveness characteristic when the pressure is designed to be increased at a rate is shown.
This set pressure increase rate can be set as a ratio between the change gradient of the brake cylinder hydraulic pressure P _B after the boosting limit of the booster 12 and the change gradient of the graph showing the target characteristic. Then, in this comparative example, in the overlap period, the deviation amount of the actual value of the master cylinder hydraulic pressure P _M , that is, the deviation from the master cylinder hydraulic pressure P _M when the booster 12 actually reaches the assisting limit. The amount is amplified by the multiplication of the set pressure increase rate and transmitted to the brake cylinder 92. Therefore, in this comparative example,
The amount of deviation of the actual value of the brake cylinder hydraulic pressure P _B from the target characteristic becomes large.

On the other hand, in the present embodiment, the deviation amount of the actual value of the master cylinder hydraulic pressure P _M is not amplified and transmitted to the brake cylinder 92 during the overlap period. Therefore, in this embodiment,
Brake cylinder hydraulic pressure P _B during the overlap period
The deviation amount of the actual value of is not so large as in the comparative example.

Therefore, according to this embodiment, it is possible to prevent the brake operation feeling from being significantly impaired during the overlap period.

The effectiveness characteristic control routine has been described above with reference to the drawings. The antilock control routine will be described below.

The antilock control routine monitors the wheel speed of each wheel and the traveling speed of the vehicle body by the wheel speed sensor 208, and the holding valve 110 is opened and the pressure reducing valve 130 is closed. Preventing each wheel from locking during vehicle braking by selectively realizing a holding state in which both 110 and the pressure reducing valve 130 are closed and a pressure reducing state in which the holding valve 110 is closed and the pressure reducing valve 130 is open. To do. The anti-lock control routine activates the pump motor 106 during the anti-lock control to cause the ABS pump 104 to operate.
The hydraulic fluid is pumped up from the reservoir 120 by the main passage 9
Return to 4.

As is clear from the above description, in the present embodiment, separate pumps are used for the pressure increase control and the antilock control, so that each brake control is concerned with interference with other brake controls. It becomes feasible without any exception,
The ease and accuracy of each brake control can be easily improved, and even if one pump fails, it prevents all brake control from becoming inexecutable.
The tolerance of the brake system for pump failures is also improved.

Further, in this embodiment, the first pressurizing piston 32 of the master cylinder 14 is pressurized behind it, so that four brake cylinders 92 are provided.
Are increased so that their hydraulic pressures are equal to each other between the two braking systems. The brake device according to the present embodiment is of a front / rear two-system type, and a difference in brake cylinder hydraulic pressure between the two systems does not cause a reduction in traveling stability of the vehicle. On the other hand, when the brake device is of the two-diagonal system, the difference in the brake cylinder hydraulic pressure between the two systems may cause deterioration of the running stability of the vehicle. Therefore, the effect of not causing a difference in the brake cylinder hydraulic pressure between the two systems during the pressure increase control is particularly effective in the diagonal two-system braking device from the viewpoint of not deteriorating the running stability of the vehicle. It makes sense.

Next, a second embodiment of the present invention will be described.
However, since the present embodiment has many elements in common with the first embodiment and only the elements relating to the pressure increase control are different, those elements will be described in detail, and the same reference numerals will be used for the other elements. By doing so, detailed description will be omitted.

In the present embodiment, as shown in FIG. 11, the master cylinder 220 has a port 222 and a communication passage 224 with respect to the master cylinder 14 in the first embodiment.
And are said to have been added. The communication passage 224 communicates the port 222 with the front pressure chamber 36 corresponding to the first pressure piston 32. Further, in the present embodiment, the pressure booster 230 has some elements added to the pressure booster 60 in the first embodiment. The added element has a communication passage 232 that connects the port 222 and the pressure increasing port 54 to each other. A normally closed electromagnetic type on-off valve 234 and a first check valve 238 whose valve opening pressure is not substantially 0 are provided in series in the middle of this communication path 232. On-off valve 234
The solenoid 240 is controlled by the ECU 242 shown in FIG. The ECU 242 corresponds to the ECU 200
And the basic configuration is common.

As shown in FIG. 11, the first check valve 238 has a valve opening pressure (a differential pressure which is a value obtained by subtracting the hydraulic pressure in the rear pressurizing chamber 50 from the hydraulic pressure in the front pressurizing chamber 36, which is not 0). If it is less than the set value), the bidirectional flow of the hydraulic fluid between the front pressurization chamber 36 and the rear pressurization chamber 50 is blocked, and if the differential pressure is about to exceed the valve opening pressure, the front pressurization is performed. The hydraulic fluid is allowed to flow from the pressure chamber 36 to the rear pressure chamber 50, so that the differential pressure does not exceed the valve opening pressure. Pressure booster 230
Further includes a bypass passage 246 that bypasses the first check valve 238.
The second check valve 248 whose valve opening pressure is substantially 0
Is provided. The second check valve 248 always allows the flow of the hydraulic fluid from the reservoir 58 side toward the front pressurizing chamber 36 side, while always blocking the reverse flow thereof.

The ROM of the computer of the ECU 242 stores a braking characteristic control routine and an antilock control routine. The effectiveness characteristic control routine is S1 and S2 of the effectiveness characteristic control routine in the first embodiment.
And steps corresponding to S3 and S4, but not common. In the effect characteristic control routine of this embodiment, the step corresponding to S3, that is, the pressure increasing control routine is shown in FIG. 13, and the step corresponding to S4, that is, the ending processing routine is shown in FIG.
Each is represented by a flow chart. Further, the antilock control routine is common to the antilock control routine in the first embodiment.

When the pressure increase control routine is executed, FIG.
As shown in FIG.
Of 0, it is determined whether or not the pressure increasing pump system related to the pressure increasing pump 66 and the pump motor 68 is normal. It is determined whether or not the rear pressure chamber 50 can be pressurized by the booster pump 66, and specifically, it is determined whether or not the pump motor 68 is disconnected or short-circuited. If it has not occurred, it is determined that the pressure boosting pump system is normal, and if it has occurred, it is determined that it is not normal. This time, assuming that it is normal, the determination is YES.
Then, in S102, the target pressurization amount ΔP of the rear pressurizing chamber 50 is determined according to the current value of the brake operating force F in the same manner as in S21, and then in S103, in the same manner as in S22. , The solenoid 8 of the pressure control valve 70 according to the determined target pressurization amount ΔP
The target current value I ^* to be supplied to 4 is determined. continue,
In S104, as in S23,
A drive current is output to the solenoid 84 of the pressure control valve 70. Then, in S105, a signal for turning it off is output to the solenoid 240 of the on-off valve 234. As a result, the open / close valve 234 is closed. Then S
At 106, a signal is output to the pump motor 68 to turn it on. As a result, the rear pressure chamber 50 is pressurized by the pressure boosting pump 66. Thus, one execution of this routine is completed.

On the other hand, this time, assuming that the boosting pump system is not normal, the determination in S101 is NO, and in S107, the solenoid 8 of the pressure control valve 70 is determined.
A signal to turn it on is output to 4. Thereby,
The rear pressurizing chamber 50 is blocked from the reservoir 58 to allow the pressure to be increased. Then, in S108, a signal for turning it on is output to the solenoid 240 of the on-off valve 234. As a result, the open / close valve 234 is opened.

When the on-off valve 234 is opened, the working fluid can flow from the front pressure chamber 36 to the rear pressure chamber 50. However, when the differential pressure obtained by subtracting the hydraulic pressure in the rear pressurizing chamber 50 from the hydraulic pressure in the front pressurizing chamber 36 is less than or equal to the valve opening pressure of the first check valve 238, the first check valve 238 This prevents the hydraulic fluid from flowing from the front pressure chamber 36 to the rear pressure chamber 50. Therefore, when the differential pressure is equal to or lower than the valve opening pressure, the pressure in the rear pressurizing chamber 50 is not increased, so that the master cylinder 14 is operated only by the booster 12. At this time, the front pressure chamber 36
The hydraulic fluid that has been pushed away by the forward movement of the first pressurizing piston 36 among the hydraulic fluid is discharged to only the brake cylinder 92 without being discharged to the rear pressure chamber 50. The first filling of the hydraulic fluid is performed on the brake cylinder 92. Therefore, the brake pedal 10
It is possible to suppress the brake operation feeling from being impaired because the brake cylinder hydraulic pressure rises insensitively to the increase in the operation stroke. When the differential pressure between the front pressure chamber 36 and the rear pressure chamber 50 is about to exceed the valve opening pressure as a result of the brake pedal 10 being further depressed, the first check valve 238 causes the front pressure chamber 36 to move away from the front pressure chamber 36. The hydraulic fluid is allowed to flow into the rear pressurizing chamber 50, and as a result, the front pressurizing chamber 3
The hydraulic pressure generated in 6 causes hydraulic pressure to be generated in the rear pressure chamber 50. As a result, this time, the master cylinder 14
However, it is operated not only by the booster 12 but also by the master cylinder 14 itself. As described above, since the pressure in the rear pressure chamber 50 can be increased by the master cylinder 14 itself, the pressure increasing pump system is not normal, and the master cylinder hydraulic pressure cannot be expected to be increased by electrical control of the pressure increasing pump system. Even in this case, it is possible to raise the pressure in the rear pressurizing chamber 50, and it is possible to improve the tolerance of the brake device for the failure of the pressure increasing pump system.

When the volume of the front pressurizing chamber 36 increases rapidly as a result of the brake pedal 10 being rapidly depressed, the hydraulic fluid from the reservoir 58 and the check valve whose valve opening pressure are both substantially zero. Since the valve 76 and the second check valve 248 are supplied to the front pressurizing chamber 36 through the order in that order, negative pressure in the front pressurizing chamber 36 due to quick brake operation is suppressed.

On the other hand, when the termination processing routine is executed, as shown in FIG. 14, first, in S121, a signal for turning it off is output to the solenoid 84 of the pressure control valve 70. The pressure control valve 70 is returned to the open state. Next, in S122, a signal for turning it off is output to the solenoid 240 of the opening / closing valve 234, and the opening / closing valve 238 is returned to the closed state.
As a result, the front pressure chamber 36 is isolated from the rear pressure chamber 50 and the reservoir 58. Subsequently, in S123, a signal for turning it off is output to the pump motor 68. Thus, one execution of this routine is completed.

Next, a third embodiment of the present invention will be described.
However, since the present embodiment has many elements in common with the second embodiment and only the pressure booster differs from the second embodiment, only the pressure booster will be described in detail and the same reference numerals will be used for the other elements. By doing so, detailed description will be omitted.

In the second embodiment, as a portion for increasing the pressure of the master cylinder 14 for controlling the effectiveness characteristic, a first pressure increasing portion having a pressure increasing pump system as a drive source and a master cylinder 14 itself as a drive source. Two pressure boosting parts are provided, and the first
The second pressure booster is operated when the pressure booster fails, but in the present embodiment, only the second pressure booster is provided, and all the effect characteristic control is performed by the second pressure booster. It is supposed to be done.

Specifically, the pressure booster 260 of the present embodiment.
15, the pressure increasing pump 66 and the pump motor 68 are omitted from the second embodiment, and an electromagnetic cut valve 262 is provided instead of the pressure control valve 70, as shown in FIG. . The cut valve 262 is an electromagnetic valve that is always in an open state, but switches to a closed state when its solenoid 264 (see FIG. 16) is excited,
It is controlled by the ECU 268 shown in FIG.

A ROM of the computer of the ECU 268 stores a braking characteristic control routine and an antilock control routine. The efficacy characteristic control routine is S1 and S2 of the efficacy characteristic control routine in the second embodiment.
And steps corresponding to S3 and S4, but not common. In the effect characteristic control routine of this embodiment, the step corresponding to S3, that is, the pressure increasing control routine is shown in FIG. 17, and the step corresponding to S4, that is, the ending processing routine is shown in FIG.
Each is represented by a flow chart. Further, the antilock control routine is common to the antilock control routine in the second embodiment.

When the pressure increase control routine is executed, FIG.
First, in S201, as shown in FIG.
A signal for turning it on is output to the second solenoid 264. As a result, the cut valve 262 is switched from the open state to the closed state, and as a result, the rear pressure chamber 50 can be pressurized. Next, in S202, a signal for turning it on is output to the solenoid 240 of the on-off valve 234.
As a result, the open / close valve 234 is switched from the closed state to the open state, and in the presence of the first check valve 238, the rear pressurizing chamber 50 can be boosted by the hydraulic pressure of the front pressurizing chamber 36. Thus, one execution of this routine is completed.

On the other hand, when the termination processing routine is executed, as shown in FIG. 18, first, in S221, the solenoid 264 of the cut valve 262 is turned off.
Is output, and the cut valve 262 is returned to the open state. As a result, bidirectional flow of hydraulic fluid between the rear pressure chamber 50 and the reservoir 58 is allowed. Next, in S222, a signal for turning it off is output to the solenoid 240 of the on-off valve 234,
As a result, the on-off valve 234 is returned to the closed state.
As a result, the front pressure chamber 36 is shut off from the rear pressure chamber 50 and the reservoir 58. Thus, one execution of this routine is completed.

Next, a fourth embodiment of the present invention will be described.
However, since the present embodiment has many elements in common with the first embodiment and is different only in the pressure booster, only the pressure booster will be described in detail, and the same reference numerals are used for the other elements. By doing so, detailed description will be omitted.

In the first embodiment, the booster pump 6 is used.
6 pressurizes the rear pressurizing chamber 50, but in the present embodiment, the pressurizing of the rear pressurizing chamber 50 is performed by the control piston that is linearly moved by the pressurizing motor. Has become.

Specifically, in the present embodiment, FIG.
As shown in FIG.
Is configured to include. The hydraulic cylinder 302 is
A control piston 306 is substantially fluid-tightly and slidably fitted into a bottomed cylindrical housing 304. In this hydraulic cylinder 302, a control pressure chamber 308 is formed in front of the control piston 306, and a hydraulic pressure is generated in the control pressure chamber 308 by advancing the control piston 306. This control pressure chamber 30
8 is always in communication with the rear pressure chamber 50 in the master cylinder 14. A control port 310 is formed in the housing 304 at a position where it can slide with the control piston 306. Although the control port 310 is not shut off from the control pressure chamber 308 by the control piston 306 in the illustrated initial position of the control piston 306,
When the control piston 306 advances from its initial position, the control piston 306 isolates it from the control pressure chamber 308. The control port 310 is in constant communication with the reservoir 58.

The pressure booster 300 further includes a pressure boosting motor 312, a speed reducer 314, and a ball screw 316.

The pressure increasing motor 312 is an EC shown in FIG.
Controlled by U318.

As shown in FIG. 19, the ball screw 316 has a structure in which a screw 322 is screwed into a nut 324 via a plurality of balls 320 that are circulated. The male screw 322 is linearly movable but not rotatable by a member not shown, while the nut 324 is rotatable but not linearly movable by a member not shown. . Therefore, if the nut 324 is rotated by the pressure increasing motor 312, the rotational movement thereof is converted into the linear movement of the male screw 322. Since the male screw 322 is integrally connected to the control piston 306 so as to move in the axial direction, when the male screw 322 is linearly moved, the control piston 306 is also linearly moved, and accordingly, the volume of the control pressure chamber 308 is reduced. Can be changed.

The speed reducer 314 is provided between the nut 324 of the ball screw 316 and the rotating shaft of the pressure increasing motor 312. The speed reducer 314 includes a small diameter gear 326 that is rotated together with the rotary shaft of the pressure increasing motor 312, and a nut 32.
4 and the large diameter gear 328 that is rotated together with the gear 4 are meshed with each other. Therefore, the pressure increasing motor 31
The rotational force of 2 is boosted and transmitted to the nut 324.

A clutch 330 is provided on the rotary shaft of the pressure increasing motor 312. Even if the current supply to the pressure increasing motor 312 is cut off, the clutch 330 holds the control piston 30.
6 has a function of mechanically preventing movement of the control pressure chamber 308 in the direction in which the hydraulic pressure decreases.

Further, in the pressure booster 300, as in the first embodiment, a bypass passage 332 that bypasses the control pressure chamber 308 is provided, and the valve opening pressure is substantially 0 in the middle of the bypass passage 332. A stop valve 334 is provided. The check valve 334, like the check valve 76 in the first embodiment, always allows the flow of the hydraulic fluid from the reservoir 58 toward the rear pressurizing chamber 50, while always blocking the reverse flow.

The ROM of the computer of the ECU 318 stores a braking characteristic control routine and an antilock control routine. The effectiveness characteristic control routine is S1 and S2 of the effectiveness characteristic control routine in the first embodiment.
And steps corresponding to S3 and S4, but not common. In the effect characteristic control routine of this embodiment, the step corresponding to S3, that is, the pressure increasing control routine is shown in FIG. 21, and the step corresponding to S4, that is, the ending processing routine is shown in FIG.
Each is represented by a flow chart. Further, the antilock control routine is common to the antilock control routine in the first embodiment.

When the pressure increase control routine is executed, FIG.
As shown in FIG. 5, first, in S301, the target pressurization amount ΔP of the rear pressurizing chamber 50 is determined based on the current value of the brake operating force F, as in S21. Next, in S302, the target rotation amount Δθ required to rotate the pressure increasing motor 312 to realize the determined target pressurization amount ΔP is determined. The relationship between the target pressurization amount ΔP and the target rotation amount Δθ is stored in the ROM, and the target rotation amount Δθ corresponding to the current target pressurization amount ΔP is determined according to the relationship. Then, in S303, the target motor current value IM ^* required to be supplied to the pressure increasing motor 312 in order to realize the determined target rotation amount Δθ is determined. Relationship between the target rotation amount Δθ and the target motor current value IM ^* is also stored in the ROM, according to the relationship, it is the target motor current value IM ^* corresponding to the present target rotation amount Δθ is determined. Subsequently, in S304, the drive current is output to the pressure increasing motor 312 in an amount equal to the determined target motor current value IM ^* . As a result, the pressure increasing motor 312 is rotated by an amount equal to the target rotation amount Δθ, and as a result, a hydraulic pressure having a height equal to the target pressure amount ΔP is generated in the control pressure chamber 308 and the rear pressure chamber 50. . Then, the master cylinder 14 is pressurized by the generated hydraulic pressure. Thus, one execution of this routine is completed.

On the other hand, when the termination processing routine is executed, as shown in FIG. 22, in S321, a signal for returning the pressure increasing motor 312 to the initial position is output. For example, booster motor 312
Is turned off. Thus, one execution of this routine is completed.

Next, a fifth embodiment of the present invention will be described.
However, the present embodiment is different from the first embodiment only in that the brake operation force sensor of the first embodiment is replaced with a master cylinder hydraulic pressure sensor, and the other points are common, and therefore only that point will be described in detail. To do.

In the first embodiment, the pressure booster 60 is used.
As a physical quantity used for control, the brake device
And the physics of the elements located upstream of the booster 60
The brake operating force F, which is an example of the amount, is used,
In the present embodiment, it is located on the downstream side of the pressure booster 60.
Master cylinder hydraulic pressure P, which is an example of the physical quantity of the element _M
Is used. This master cylinder hydraulic pressure P_MIs a figure
23, the master cylinder hydraulic pressure sensor 350
Detected by the master cylinder hydraulic pressure sensor 350
Are connected to the ECU 352.

The ROM of the computer of the ECU 352 stores a braking characteristic control routine and an antilock control routine. The efficacy characteristic control routine is S1 to S3 of the efficacy characteristic control routine in the first embodiment.
Corresponding to, but not common to, and a step common to S4. The effectiveness characteristic control routine in this embodiment is shown in the flowchart of FIG. Further, the antilock control routine is common to the antilock control routine in the first embodiment.

This routine is repeatedly executed after the ignition switch of the vehicle is turned on. In each execution, first, in S351, the master cylinder hydraulic pressure P _M is detected based on the master cylinder hydraulic pressure signal from the master cylinder hydraulic pressure sensor 350. Next, S3
At 52, it is judged if the detected master cylinder hydraulic pressure P _M is higher than the reference value P _TH . This reference value P _TH
Corresponds to the reference value F _TH in the first embodiment. This time, assuming that the detected master cylinder hydraulic pressure P _M is higher than the reference value P _TH , the determination becomes YES, and the pressure increase control routine is executed in S353. On the other hand, this time, assuming that the detected master cylinder hydraulic pressure P _M is not higher than the reference value P _TH , the determination becomes NO, and in S354, the end process is performed in the same manner as in S4. The routine is executed. In any case, one execution of the effective characteristic control routine is completed.

This embodiment can be influenced by the pressure increase control.
Master cylinder hydraulic pressure P, which is a physical quantity _MBased on the detected value of
The pressure booster 60 is controlled by the
Based on the detected value of the braking force F, which is a physical quantity
This is different from the first embodiment in which the pressure intensifying device 60 is controlled.
Therefore, the pressure increase control routine in this embodiment is
It is basically the same as the routine of 6, but due to the above differences
There are also differences. Below, only the differences are detailed
explain.

Controlling the pressure booster 60 based on the detected value of the brake operating force F that is not affected by the pressure boosting control means that the detected value of the brake operating force F is detected before and after the pressure boosting control. It means that the master cylinder hydraulic pressure P _M when the pressure increase control is not performed can be assumed based on the above. On the other hand, as in the present embodiment, controlling the pressure booster 60 based on the detected value of the master cylinder hydraulic pressure P _M , which is a physical quantity that can be influenced by the pressure boosting control, means that pressure boosting is started. Before, it is possible to use the detected value of the master cylinder hydraulic pressure P _{M as} the value corresponding to the brake operating force F, but after the start of pressure increase,
This means that it cannot be used as a value corresponding to the brake operating force F. However, after the pressure increase is started, it is constant between the detected value of the master cylinder hydraulic pressure P _M affected by the pressure increase control and the master cylinder hydraulic pressure P _M when it is assumed that the pressure increase control is not performed. The relationship is established. Therefore, in the present embodiment, by utilizing the relationship, the master cylinder hydraulic pressure P _M when the boosting control is not performed is assumed based on the detected value of the master cylinder hydraulic pressure P _M , and the estimated value thereof is assumed. The target pressurization amount ΔP is determined with reference to.

By the way, the master cylinder hydraulic pressure sensor 35
At 0, the pressure to be detected is transmitted by the hydraulic fluid having a damping characteristic, so the master cylinder hydraulic pressure sensor 350 can detect the pressure in the damping state, while the brake operating force sensor 204 does not. , The braking force cannot be detected in the damping state unless special measures are taken. Therefore, the master cylinder hydraulic pressure sensor 350 can easily detect the pressure by appropriately adjusting the pressure so that the vibration, which is a disturbance, can be detected. It is difficult to detect a certain amount of noise.
Therefore, in the present embodiment, since the master cylinder hydraulic pressure sensor 350 is used as the brake operation force related amount sensor, the brake operation force sensor 240 can more accurately detect what the driver intends for the brake. It will be possible.

Further, like the other sensors mounted on the vehicle, it is desirable that the master cylinder hydraulic pressure sensor 350 also perform a primary check before the effective characteristic control is first started in each vehicle traveling. Also,
The primary check includes not only static checks such as disconnection and short circuit, but also so-called dynamic checks that check the relationship between the actual value of the physical quantity to be detected and the detected value. However, unlike the case of the present embodiment, in the brake device of the type in which the master cylinder hydraulic pressure is increased on the downstream side of the master cylinder 14, the master cylinder hydraulic pressure cannot be generated unless the brake operation is being performed. Dynamic checking is impossible. On the other hand, in this embodiment, the master cylinder 1
Since it is a brake device of the type capable of pressurizing the fourth pressurizing piston 32 from behind, it is possible to pressurize the master cylinder 14 even when the brake is not being operated. Dynamic check can be executed.

Further, in the present embodiment, the master cylinder hydraulic pressure sensor 350 is provided, while in the present embodiment, the master cylinder hydraulic pressure and the brake cylinder hydraulic pressure are substantially equal to each other. Therefore, according to the present embodiment, the master cylinder hydraulic pressure sensor 350 can also detect the brake cylinder hydraulic pressure, so that the control accuracy of the brake cylinder hydraulic pressure can be improved as compared with a brake device that cannot detect the brake cylinder hydraulic pressure. It can be easily improved.

Next, a sixth embodiment of the present invention will be described.
However, since the present embodiment has many elements in common with the first embodiment and is different only in the pressure booster, only the pressure booster will be described in detail, and the same reference numerals are used for the other elements. By doing so, detailed description will be omitted.

In the first embodiment, the pressure booster 64
However, the rear pressurizing chamber 50 is pressurized by driving the pressure increasing pump 66 (hydraulic pump) by using the pump motor 68 as a drive source. On the other hand, in the present embodiment, as shown in FIG.
The pressure booster 370 uses the intake pipe (negative pressure source) of the automobile engine as a drive source, so that the vacuum pump 3
The rear pressure chamber 50 is pressurized by causing 74 to perform a pumping operation.

The vacuum pump 374 is provided in the housing 3
It is equipped with 76. Inside the housing 376,
A stepped cylindrical hole is formed in which the large diameter portion 378 and the small diameter portion 380 are coaxially connected. A plunger 382 is fitted in the small diameter portion 380 in a substantially airtight and slidable manner. As a result, the plunger 3 in the small diameter portion 380 is
A pump chamber 384 containing a hydraulic fluid is formed in front of 82. The pump chamber 384 is connected to the rear pressure chamber 50 and the reservoir 58. However, the rear pressure chamber 5
0 through the discharge valve 386 and the reservoir 58 through the suction valve 3
They are connected via 88. The discharge valve 386 is
The check valve is configured to allow the flow of hydraulic fluid from the pump chamber 384 to the rear pressurization chamber 50, but to prevent the flow in the opposite direction, while the suction valve 388 is directed from the reservoir 58 to the pump chamber 384. Allow the flow of hydraulic fluid,
The reverse flow is constituted by a check valve that blocks the flow. Therefore, if the volume of the pump chamber 384 decreases,
If the hydraulic fluid is discharged only to the rear pressure chamber 50 and increases,
The hydraulic fluid will be sucked only from the reservoir 58.

The space inside the large diameter portion 378 is divided into two by a diaphragm 390. The variable pressure chamber 392 connected to the three-way valve 391 and the atmospheric chamber 39 communicating with the atmosphere.
It is divided into four. Diaphragm 390
Is airtightly attached to the large diameter portion 378 on the outer periphery thereof, and is airtightly attached to the protruding portion 396 of the plunger 382 which is protruded from the small diameter portion 380 on the inner periphery thereof. The transformer chamber 392 has a plunger 382.
A return spring 398 for urging the diaphragm 390 toward the illustrated initial position is provided.

A guide hole 400 extending from the tip of the plunger 382 is formed in the projecting portion 396, and a guide shaft 402 slidably fitted in the guide hole 400 is fixed to the housing 376, whereby the plunger 382 is fixed. 382 is axially guided. The space in the large diameter portion 378 is effectively used for the guide, and as a result, the axial dimension of the entire vacuum pump 374 is made as short as possible.

The three-way valve 391 has first to third ports 410, 412, 414. 3-way valve 391
Is in a first state where the first port 410 communicates with the second port 412 while the solenoid 416 (see FIG. 26) thereof is not energized and is blocked from the third port 414, and when energized, While the first port 410 communicates with the third port 414, it switches to the second state in which it is blocked from the second port 412. And the three-way valve 391 is
The first port 410 is connected to the variable pressure chamber 392, the second port 412 is connected to the atmosphere, and the third port 414 is connected to the intake pipe (represented by "I / MF" in the drawing). Therefore, in the first state of the three-way valve 391, atmospheric pressure is introduced into the variable pressure chamber 392, and as a result, the plunger 382 is biased in the backward direction (direction in which the volume of the pump chamber 384 increases), while In the two states, negative pressure is introduced into the variable pressure chamber 392 from the intake pipe, and as a result, the plunger 382 is urged in the forward direction (direction in which the volume of the pump chamber 384 decreases). And 3-way valve 3
As will be described in detail later, the solenoid 91 is alternately switched between an ON state and an OFF state at the time of the effect characteristic control, and as a result, a state in which the atmospheric pressure is introduced into the variable pressure chamber 392 and a negative pressure are generated. The state to be introduced is switched alternately. Since the plunger 382 is operated based on the differential pressure across the diaphragm 390, the plunger 382 is retracted in the first state of the solenoid 416, whereby the hydraulic fluid is sucked from the reservoir 58 into the pump chamber 384, while In the second state, the plunger 382 is moved forward, whereby the hydraulic fluid is discharged from the pump chamber 384 to the rear pressurizing chamber 50.

As described above, the vacuum pump 374
Are pumped, and as a result, the rear pressure chamber 50 is intermittently pressurized.

That is, in the present embodiment, the vacuum pump 374 is constituted by the housing 376, the plunger 382, the pump chamber 384, the diaphragm 390, the three-way valve 391, the discharge valve 386 and the suction valve 388.

In this vacuum pump 374,
One end of the plunger 382 is attached with the diaphragm 390 as an input part, while the other end is accommodated in the pump chamber 384 as an output part. As described above, in the vacuum pump 374, the plunger 382, which is one member, is involved in both the input and the output. Therefore, the vacuum pump of the type in which different members are involved in the input and the output, respectively. Compared with, the simplification and downsizing of the structure can be realized more easily.

The pressure booster 370 further includes a cut valve 42.
It has 0. The cut valve 420 is connected to the rear pressure chamber 50 and the reservoir 58 in a state of bypassing the vacuum pump 374. The cut valve 420 is a normally closed and electromagnetic on-off valve having a solenoid 422.

The cut valve 420 and the three-way valve 391
Is controlled by the ECU 430 as shown in FIG. The basic configuration of the ECU 430 is common to the ECU 200 in the first embodiment.

A ROM of the computer of the ECU 430 stores a braking characteristic control routine and an antilock control routine. The effectiveness characteristic control routine is S1 and S2 of the effectiveness characteristic control routine in the first embodiment.
And steps corresponding to S3 and S4, but not common. In the effect characteristic control routine of this embodiment, the step corresponding to S3, that is, the pressure increasing control routine is shown in FIG. 27, and the step corresponding to S4, that is, the ending processing routine is shown in FIG.
Each is represented by a flow chart. Further, the antilock control routine is common to the antilock control routine in the first embodiment.

When the pressure increase control routine is executed, FIG.
First, in S401, as shown in FIG.
A signal for turning on the solenoid 422 of 0 is output. As a result, the cut valve 420 is switched from the open state to the closed state, and as a result, the pressure in the rear pressure chamber 50 can be increased. Next, in S402, ON-OFF control for alternately switching the solenoid 416 of the three-way valve 391 between the ON state and the OFF state is performed. As a result, the rear pressurizing chamber 50 is pressurized by the pumping operation of the vacuum pump 374. Thus, one execution of this routine is completed.

On the other hand, when the termination processing routine is executed, as shown in FIG. 28, first, in S411, the solenoid 422 of the cut valve 420 is turned off.
Is output, which causes the cut valve 420 to return to the open state. As a result, bidirectional flow of hydraulic fluid between the rear pressure chamber 50 and the reservoir 58 is allowed. Next, in S412, a signal for turning it off is output to the solenoid 416 of the three-way valve 391,
Thereby, the three-way valve 391 is stopped in the first state. As a result, the pressure increase in the rear pressure chamber 50 is terminated. Thus, one execution of this routine is completed.

FIG. 29 is a graph showing how the brake cylinder hydraulic pressure P _B is increased by the vacuum pump 374. In the present embodiment, when the brake operating force F reaches the reference value F _TH and the pressure increase start condition is satisfied, the brake cylinder hydraulic pressure P _B is increased by a constant amount ΔP. As a result, the brake cylinder hydraulic pressure P _B corresponding to the same brake operating force F becomes higher than that when the pressure increase control is not started, and the vehicle body deceleration G also becomes higher. Therefore, the braking effect is improved, and the vehicle body deceleration G at the boosting limit of the booster 12 is increased. As a result, the boosting performance of the booster 12 is apparently improved.

FIG. 30 is a graph showing an example of specifications to be met when designing the brake device. In this graph, the operation stroke S of the brake pedal 10
The relationship between _P and the vehicle deceleration G is shown. The relationship is that after the pressure increase start condition is satisfied, the operation stroke S
It shows that the vehicle body deceleration G increases by 0.3 [G] in response to _P being operated by 15 [mm]. The graph further shows that an increase in the operation stroke S _P of 15 [mm] corresponds to an increase in the volume Q of the rear pressurizing chamber 50 of 1 [cc] and that the vehicle body deceleration G is 0.3.
[G] Increasing the brake cylinder hydraulic pressure P _B is 3
It is also shown to correspond to the increase in [MPa] pressure.

Here, each pressurizing piston 32, 34 of the master cylinder 14 receives the hydraulic pressure of each pressurizing chamber 36, 38 in the area where the first pressurizing piston 32 receives the hydraulic pressure of the rear pressurizing chamber 50. When the ratio to the area is 0.6, in order to set the pressure increase amount ΔP of the brake cylinder hydraulic pressure P _B to 3 [MPa], the hydraulic pressure increase amount ΔP of the rear pressurizing chamber 50 is set to 5 [MP].
a] is required. Further, here, the diameter of the plunger 382 of the vacuum pump 374 is set to φ7 [m
m], and the diameter of the diaphragm 396 is φ70 [mm], when the negative pressure of the negative pressure source is about 400 [mmHg], a hydraulic pressure of 5 [MPa] can be generated in the rear pressurizing chamber 50. At this time, in order to discharge 1 [cc] of hydraulic fluid from the pump chamber 384 from the rear pressure chamber 50, it is necessary to stroke the plunger 382 by 26 [mm]. Therefore, the vacuum pump 374 as a whole has a diameter of about 80 mm and an axial length of 70 mm.
It becomes about [mm].

Here, the diameter of the cylindrical portion forming the variable pressure chamber and the constant pressure chamber of the housing of the booster 12 is 8 [i
nch] and the thickness is 80 [mm], comparing the brake characteristics according to the present embodiment with the brake characteristics when the effectiveness control device is removed from the present embodiment, as shown in the graph in FIG. become. The braking characteristic according to the present embodiment is not provided with the pressure increasing device 370,
When it is attempted to realize the same degree of assist limit as in the present embodiment by the conventional brake device that assists the brake operating force F only with the booster 12, the diameter of the cylindrical portion of the booster 12 is 10 [inch] and the thickness is It becomes 80 [mm]. Here, comparing the sum of the volume of the booster 12 and the volume of the vacuum pump 374 in the present embodiment with the volume of the booster 12 of the conventional brake device that realizes the same assisting limit as in the present embodiment, The embodiment is smaller than the conventional braking device.
This means that the space required for mounting the brake device on the vehicle can be reduced.

Therefore, according to the present embodiment, the boosting limit of the booster 12 is increased by the pressure increasing device 370 different from the booster 12, and the size of the entire brake device is reduced. Even if the booster 12 breaks down, as long as the booster 370 does not break down, the brake operating force F can be assisted, and the reliability of the brake operation can be improved.

In addition, in addition, in the present embodiment,
The brake cylinder hydraulic pressure P _B is increased by a constant amount ΔP during the effectiveness control, but it should be increased by a variable increase amount as in the first embodiment. You can Then, as a technique for changing the pressure increase amount, for example, the solenoid 416 of the three-way valve 391 is turned on.
A technique of changing a time ratio for switching between the N state and the OFF state, that is, a technique for changing the duty ratio, and switching the solenoid 422 of the cut valve 420 between the ON state and the OFF state during the effect characteristic control, and the solenoid 422. It is possible to adopt a technique of changing the duty ratio of the.

In addition, the amount ΔP of pressurization of the rear pressurization chamber 50 by the hydraulic fluid discharged from the pump chamber 384 to the rear pressurization chamber 50 by one stroke of the plunger 382 can be predicted. Paying attention to this fact, the brake cylinder hydraulic pressure P _B is increased by
It is also possible to change it according to the number of strokes of the plunger 382.

Although some of the embodiments of the present invention have been described in detail with reference to the drawings, these are merely examples.
The present invention, in addition to the embodiments described in the above [Problems to be solved by the invention, problem solving means and effects of the invention], various modifications and improvements are made based on the knowledge of those skilled in the art. It can be carried out.

[Brief description of drawings]

FIG. 1 is a system diagram showing a mechanical configuration of a brake device according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a pressure control valve in FIG.

FIG. 3 is a solenoid current value I in the pressure control valve of FIG.
3 is a graph showing the relationship between the solenoid attraction force F ₁ and the solenoid attraction force F ₁ .

FIG. 4 is a block diagram showing an electrical configuration of the brake device.

5 is a flow chart showing an efficacy characteristic control routine executed by a computer of the ECU of FIG.

FIG. 6 is a flowchart showing details of S3 in FIG. 5 as a pressure increase control routine.

FIG. 7 is a graph showing a relationship between a brake operating force F and a target pressurization amount ΔP in the pressure increase control routine.

FIG. 8 is a target pressurization amount ΔP in the pressure increase control routine.
3 is a graph showing the relationship between solenoid attraction force F ₁ and solenoid current value I.

9 is a flowchart showing the details of S4 in FIG. 5 as an end processing routine.

FIG. 10 is a graph showing the effect of controlling the braking characteristic of the braking device.

FIG. 11 is a system diagram showing a mechanical configuration of a brake device according to a second embodiment of the present invention.

FIG. 12 is a block diagram showing an electrical configuration of the brake device.

13 is a flowchart showing a pressure increase control routine executed by a computer of the ECU shown in FIG.

14 is a flowchart showing an end processing routine executed by a computer of the ECU shown in FIG.

FIG. 15 is a system diagram showing a mechanical configuration of a brake device according to a third embodiment of the present invention.

FIG. 16 is a block diagram showing an electrical configuration of the brake device.

17 is a flowchart showing a pressure increase control routine executed by a computer of the ECU shown in FIG.

18 is a flowchart showing an end processing routine executed by a computer of the ECU shown in FIG.

FIG. 19 is a system diagram showing a mechanical configuration of a brake device according to a fourth embodiment of the present invention.

FIG. 20 is a block diagram showing an electrical configuration of the brake device.

21 is a flow chart showing a pressure increase control routine executed by a computer of the ECU in FIG.

22 is a flowchart showing an end processing routine executed by a computer of the ECU shown in FIG.

FIG. 23 is a block diagram showing an electrical configuration of a brake device that is a fifth embodiment of the present invention.

FIG. 24 is a flowchart showing a braking characteristic control routine executed by a computer of the ECU in FIG. 23.

FIG. 25 is a system diagram showing a mechanical configuration of a brake device that is a sixth embodiment of the present invention.

FIG. 26 is a block diagram showing an electrical configuration of the brake device.

27 is a flowchart showing a pressure increase control routine executed by a computer of the ECU shown in FIG.

28 is a flowchart showing an end processing routine executed by a computer of the ECU shown in FIG.

FIG. 29 is a graph for explaining the details of pressure increase control by the brake device.

FIG. 30 is a graph for explaining one specification when designing the brake device.

FIG. 31 is a graph for explaining the operation of the brake device designed to meet the one design specification shown in FIG. 30.

[Explanation of symbols]

10 brake pedal 12 vacuum booster 14,220 master cylinder 20 housing 32,34 first and second pressurizing pistons 36,38 front pressurizing chamber 50 rear pressurizing chamber 64,230,260,300,370 pressure booster 90 brake 92 Brake cylinder 200, 242, 268, 318, 352, 430 Electronic control unit ECU 374 Vacuum pump

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-303967 (JP, A) JP-A-52-4969 (JP, A) JP-A-10-35477 (JP, A) JP-A-52- 13073 (JP, A) JP 52-77986 (JP, A) JP 10-152041 (JP, A) JP 51-144878 (JP, A) JP 62-225454 (JP, A) 2-25359 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60T 13/12

Claims (6)

(57) [Claims] 1. A booster for boosting the operating force of a brake operating member using a brake operating member and a negative pressure source as a drive source, the booster having a negative pressure of the negative pressure source.
Due to fluctuations, the above-mentioned brake when reaching the support limit
The magnitude of the assist limit operating force, which is the operating force of the operating member, fluctuates
The vacuum booster and the pressurizing piston, which is moved forward by receiving the operating force of the vacuum booster, are fitted in the housing in a liquid-tight and slidable manner. A pressurizing chamber and a rear pressurizing chamber are formed, and a master cylinder in which hydraulic pressure is generated in the front pressurizing chamber by advancing the pressurizing piston and a front pressurizing chamber in the master cylinder are connected via a liquid passage. A brake having a brake cylinder that suppresses wheel rotation, and the operating force of the brake operating member is equal to the negative pressure of the negative pressure source.
If the actual value is equal to the lower bound of its expected range of variation
Assuming that the vacuum booster reaches the limit of assistance,
Examples boosting pressure boosting starting condition when it reaches the limit operating force is established by generating a pressure in the rear pressure chamber, the liquid of the brake cylinder in the case where the pressure increase start condition is not satisfied when reaching A hydraulic pressure higher than the pressure is generated in the brake cylinder, and the vacuum brake
Of the brakes due to the
A brake device including a pressure increasing device that suppresses a decrease in effectiveness . Wherein said master cylinder, the pressure piston is two in the housing, is arranged in series with each other, thereby, the front pressurizing chamber 2, in claim 1 which is formed in series with each other The described braking device. 3. The pressure increasing device comprises: (a) a brake operation force related amount sensor for detecting a brake operation force related amount related to an operation force of the brake operation member; and (b) electrically operated. A pressure generation / control device that generates pressure in the rear pressure chamber and controls its height, and (c) in advance between the brake operation force related amount and the target pressure to be generated in the rear pressure chamber. According to a defined relationship, a target pressure is determined according to the brake operation force related amount detected by the brake operation force related amount sensor, and the pressure generation / control device is controlled so that the determined target pressure is realized. brake device according to claim 1 or 2 and a controller. 4. The pressure booster generates pressure in the rear pressurizing chamber by using a hydraulic pump connected to the rear pressurizing chamber on the discharge side without using an accumulator. The brake device according to any one of Items 1 to 3 . Wherein said front pressurizing chamber and said brake cylinder, during operation of the hydraulic pump, to claim 4 in which they and the front pressure chamber and the brake cylinder is connected in a state of not continue to cut off from each other The described braking device. 6. The brake device according to claim 1, wherein the pressure increasing device includes a vacuum pump that generates pressure in the rear pressure chamber by using the negative pressure source as a drive source.