JP4871242B2 - Brake hydraulic control device for vehicle - Google Patents

Description

  The present invention provides an input oil passage that is connected to a master cylinder, a cut valve that opens and closes the input oil passage, an output oil passage that is connected to a wheel brake, a reservoir that can absorb hydraulic oil, and an input oil passage between an input oil passage and an output oil passage. And a pressure increasing state in which the output oil passage and the reservoir are shut off, a pressure reducing state in which the input oil passage and the output oil passage are shut off and in communication between the output oil passage and the reservoir, and the input oil passage, the reservoir and the output Brake hydraulic control valve means that can switch the hydraulic pressure holding state that shuts off both of the oil path and the hydraulic oil absorbed by the reservoir is sucked through the pressure reducing oil path, or hydraulic oil from the master cylinder is sucked through the suction oil path A hydraulic pump, a suction valve that opens and closes the suction oil passage, a boost oil passage that induces the discharge hydraulic pressure of the hydraulic pump into the input oil passage downstream of the cut valve, and a brake hydraulic pressure Control valve means and an electronic control unit for controlling the cut valve. When the hydraulic pump device is operated while closing the cut valve and controlling the brake hydraulic control valve means, the discharge hydraulic pressure is supplied to the desired wheel brake. The present invention relates to an improvement in a brake hydraulic control device for a vehicle that can perform automatic braking such as traction control, vehicle running posture control, and vehicle rear-end collision prevention control.

Such a brake hydraulic control device for a vehicle is already known as disclosed in Patent Document 1 below.
JP 2003-341499 A

  In the above-mentioned publication, the suction valve is constituted by a normally closed electromagnetic on-off valve. During automatic braking, the cut valve is closed and the suction valve is opened to operate the hydraulic pump device. Thus, the hydraulic pump device sucks the hydraulic oil of the master cylinder through the suction oil passage, boosts the pressure and supplies it to the desired wheel brake. The automatic brake is activated during normal braking, that is, during operation of the master cylinder. When activated or when the master cylinder is activated during automatic braking, the pulsation of the suction pressure of the hydraulic pump device is transmitted as vibration to the brake pedal that operates the master cylinder, which may harm the driver's brake operation feeling. There is.

  The present invention has been made in view of such circumstances, and when the automatic brake is activated during the operation of the master cylinder, or when the master cylinder is activated during the automatic brake, the pulsation of the suction pressure of the hydraulic pump device is caused. Transmission to the master cylinder side is prevented as much as possible, the driver's brake operation feeling is good, and during normal braking, the output pressure of the master cylinder is not burdened on the suction side of the hydraulic pump device, An object of the present invention is to provide a brake hydraulic control device for a vehicle that can improve durability.

  To achieve the above object, the present invention includes an input oil passage connected to a master cylinder, a cut valve for opening and closing the input oil passage, an output oil passage connected to a wheel brake, a reservoir capable of absorbing hydraulic oil, A pressure-increasing state in which the input oil passage and the output oil passage are communicated and the output oil passage and the reservoir are shut off, a pressure-increasing state in which the input oil passage and the output oil passage are shut off and the output oil passage and the reservoir are communicated with each other; And brake hydraulic control valve means that can switch the hydraulic pressure holding state that shuts off both the input oil path and the reservoir and the output oil path, and the hydraulic oil absorbed in the reservoir is sucked in through the decompression oil path or from the master cylinder The hydraulic pump that draws hydraulic oil through the suction oil path, the suction valve that opens and closes the suction oil path, and the hydraulic pump discharge hydraulic pressure to the input oil path downstream from the cut valve In a vehicle brake hydraulic control device comprising a boost oil passage and an electronic control unit for controlling a brake hydraulic control valve means and a cut valve, the suction valve is closed when receiving the output hydraulic pressure of the master cylinder, A first feature is that the suction oil passage is opened and closed so that when the suction pressure of the hydraulic pump device is received in the closed state, the suction pressure is controlled to be constant.

  According to the present invention, in addition to the first feature, the suction valve includes a valve housing, a stepped valve piston including a small-diameter piston portion and a large-diameter piston portion fitted in the valve housing, and the valve An auxiliary piston fitted to the housing and abutting against the end face of the large-diameter piston portion. The valve housing has a front end portion of the small-diameter piston portion and an inlet port connected to the upstream side of the suction oil passage. An inlet oil chamber that faces the opposed end portions of the large-diameter piston portion and the auxiliary piston, communicates with the inlet oil chamber, and opens an outlet port that communicates with the downstream side of the suction oil passage. When the outer end of the piston faces and an auxiliary oil chamber connected to the upstream side of the suction oil passage is formed, the valve piston moves to the inlet oil chamber side in the small-diameter piston portion A valve portion for closing the entry port is provided, and when the valve piston closes the inlet port, the valve piston is connected to the valve piston for urging it in the opening direction of the valve portion. The second feature is that the pressure receiving area facing the inlet port of the portion and the pressure receiving area facing the auxiliary oil chamber of the auxiliary piston are set equal.

  The valve housing corresponds to the body 3a of the modulator in the embodiment of the present invention described later, and the valve portion corresponds to the valve plate 42.

  According to the first feature of the present invention, since the suction valve is a normally open type, during automatic braking, the hydraulic pump device sucks the hydraulic oil in the master cylinder through the suction oil passage and the suction valve, and increases the pressure. The desired wheel brake can be supplied.

  In addition, the suction valve closes when it receives the output hydraulic pressure of the master cylinder. Therefore, during normal braking that operates the master cylinder, the suction oil passage is shut off and the output hydraulic pressure of the master cylinder acts on the suction side of the hydraulic pump device. This can contribute to improving the durability of the hydraulic pump device.

  Furthermore, when the suction valve receives the suction pressure of the hydraulic pump device in its closed state, the suction oil passage is opened and closed so that the suction pressure is controlled to be constant, so the automatic brake is activated during the master cylinder operation. Even when the master cylinder is operated during automatic braking, the pressure fluctuation of the suction oil passage due to the suction action of the hydraulic pump device is kept small, and the vibration of the brake pedal caused by the pressure fluctuation is effectively reduced. This can reduce the driver's brake operation feeling.

  According to the second aspect of the present invention, the suction valve that can achieve the above-described effect can be configured mechanically, which can contribute to the cost reduction of the brake hydraulic control device for the vehicle.

  Embodiments of the present invention will be described based on an embodiment of the present invention shown in the accompanying drawings.

  FIG. 1 is a hydraulic circuit diagram of a front wheel drive type automobile brake device equipped with a brake hydraulic control device according to the present invention, FIG. 2 is an enlarged longitudinal sectional view of a suction valve in the valve open state in the hydraulic circuit, and FIG. FIG. 3 is a view corresponding to FIG. 2 showing a closed state of the suction valve.

  First, in FIG. 1, the master cylinder M is configured in a tandem type having a pair of front and rear first and second output ports 1a, 1b that output brake hydraulic pressure in response to an input applied from a brake pedal P to a piston. The first and second input oil passages 2a and 2b individually connected to the first and second output ports 1a and 1b, the left front wheel wheel brake Ba, the right rear wheel wheel brake Bb, and the right front wheel wheel brake The modulator 3 is interposed between the first to fourth output oil passages 12a to 12d individually provided for Bc and the left rear wheel brake Bd.

  The modulator 3 includes brake control valve means 4. The brake control valve means 4 includes first to fourth inlet valves 5a individually corresponding to a left front wheel brake Bb, a right rear wheel brake Bb, a right front wheel brake Bc, and a left rear wheel brake Bd, respectively. To 5d and the first to fourth outlet valves 6a to 6d individually corresponding to the wheel brakes Ba to Bd, and the inlet valves 5a to 5d are normally open linear solenoid valves. The outlet valves 6a to 6d are normally closed linear solenoid valves. The first input oil passage 2a is connected to the inlets of the first and second inlet valves 5a and 5b, and the second input oil passage 2b is connected to the inlets of the third and fourth inlet valves 5c and 5d. A first output oil passage 12a is provided at the outlet of the first inlet valve 5a and the inlet of the first outlet valve 6a. A second output oil passage 12b is provided at the outlet of the second inlet valve 5b and the inlet of the second outlet valve 6b. The third output oil passage 12c is connected to the outlet of the three inlet valve 5c and the inlet of the third outlet valve 6c, and the fourth output oil passage 12d is connected to the outlet of the fourth inlet valve 5d and the inlet of the fourth outlet valve 6d, respectively. .

  First and second hydraulic pump devices 8A, 8B driven by a common electric motor 17 are provided, and each of the hydraulic pump devices 8A, 8B has a plurality of interlocked connections that are shifted from each other at equal intervals. It consists of plunger pumps 8, 8. The outlets of the first and second outlet valves 6a and 6b are connected to the suction ports of the plunger pumps 8 of the first hydraulic pump device 8A via the first pressure reducing oil passage 7a, and the third and fourth outlet valves 6c and 6d. Is connected to the suction port of each plunger pump 8 of the second hydraulic pump device 8B via the second pressure reducing oil passage 7b, and the first and second pressure reducing oil passages 7a, 7b are connected to the first and second reservoirs 9a. , 9b are connected to each other.

  The discharge port 62 of each plunger pump 8 of the first hydraulic pump device 8A is connected to the first input oil passage 2a via the first pressure increase oil passage 11a, and the discharge port of each plunger pump 8 of the second hydraulic pump device 8B. 62 connects the second boost oil passage 11b to the second input oil passage 2b. Further, an orifice 10 and a damper 13 for attenuating pulsation of the discharge pressure of the corresponding hydraulic pump devices 8A and 8B are connected to the first and second pressure increasing oil passages 11a and 11b.

  A cut valve 14 is interposed in the first and second input oil passages 2a and 2b upstream from the connection point of the first and second pressure increase oil passages 11a and 11b. When the cut valve 14 is closed and the hydraulic pressure of the first and second pressure increase oil passages 11a and 11b exceeds a set value, the excess hydraulic pressure is released to the first and second input oil passages 2a and 2b. It consists of a normally open linear solenoid valve.

  A first suction oil passage 15a branched from the first input oil passage 2a upstream from the cut valve 14 is connected to the suction port of each plunger pump 8 of the first hydraulic pump device 8A. A second suction oil passage 15 b branched from the second input oil passage 2 b upstream of the cut valve 14 is connected to the suction port of each plunger pump 8.

  Connected to the first input oil passage 2a or the second input oil passage 2b is an oil pressure sensor 21 (master cylinder operating state detection means) that detects the output oil pressure of the master cylinder M and outputs a signal corresponding thereto. Is input to the electronic control unit 20. In addition to the hydraulic pressure sensor 21, the electronic control unit 20 includes a wheel speed sensor 22 that detects the rotational speed of each wheel, a steering angle sensor 23 that detects the steering angle of the steering handle, and a yaw rate sensor that detects the yaw rate of the vehicle. 24, detection signals from a radar 25 or the like for detecting the distance to an obstacle ahead of the vehicle are input, and these signals are calculated to control each part of the brake control valve means 4 and 4.

  Each suction oil passage 15a, 15b is provided with a normally-open suction valve 30 that opens and closes according to the output hydraulic pressure of the master cylinder M and the suction pressure of the corresponding hydraulic pump device 8A, 8B. A damper 26 that attenuates pressure pulsation generated on the suction valve 30 side is connected to each of the upstream suction oil passages 15a and 15b.

  Next, the suction valve 30 will be described with reference to FIGS.

  The body 3a of the modulator 3 is provided with a first cylinder bore 31, a second cylinder bore 32, and a third cylinder bore 33 sequentially connected from one axial end side. The respective diameters of the second cylinder bore 32 at the intermediate position are the largest, the first cylinder bore 31 is the next largest, and the third cylinder bore 33 is the smallest. An inlet port 34 is provided on the inner end surface of the first cylinder bore 31, an outlet port 35 is provided on the inner surface of the second cylinder bore 32 near the third cylinder bore 33, and an auxiliary port 36 is provided on the inner end surface of the third cylinder bore 33. The inlet port 34 and the auxiliary port 36 are connected to the upstream side (master cylinder M side) of the suction oil passages 15a and 15b, respectively, and the outlet port 35 is connected to the downstream side (hydraulic pump device) of the suction oil passages 15a and 15b. 8A and 8B) are connected.

  In the first and second cylinder bores 31, 32, a small-diameter piston portion 37a and a large-diameter piston portion 37b constituting a stepped valve piston 37 are slidable via first and second seal members 39, 40, respectively. The auxiliary piston 38 is slidably fitted to the third cylinder bore 33 via the third seal member 41.

  A valve plate 42 made of an elastic material that is seated on the inner end surface of the first cylinder bore 31 and closes the inlet port 34 (see FIG. 3) is joined to the distal end surface of the small-diameter piston portion 37a. , The valve-opening spring 43 for biasing the large-diameter piston portion 37b in the opening direction of the valve plate 42 is contracted. At that time, the opening position of the valve plate 42 is regulated by the large diameter piston portion 37b coming into contact with the inner end surface of the third cylinder bore 33 via the auxiliary piston 38 (see FIG. 2).

  The first seal member 39 defines an inlet oil chamber 44 that houses the distal end side of the small diameter piston portion 37 a in the first cylinder bore 31, and the first and second seal members 39, 40 are second from the first cylinder bore 31. An atmospheric pressure chamber 45 for accommodating the valve-opening spring 43 is defined over the cylinder bore 32, and the second and third seal members 40, 41 are outlets for accommodating the opposed end portions of the large-diameter piston portion 37b and the auxiliary piston 38 in contact with each other. The oil chamber 46 is defined, and the third seal member 41 defines an auxiliary oil chamber 49 that accommodates the outer end portion of the auxiliary piston 38 in the third cylinder bore 33. The inlet oil chamber 44 communicates with the inlet port 34 when the valve plate 42 is opened, and the outlet oil chamber 46 communicates with the outlet port 35 at all times.

  The valve piston 37 includes a horizontal hole 47a that opens from the outer peripheral surface of the small diameter piston portion 37a to the inlet oil chamber 44, and a vertical hole 47b that extends from the center portion of the horizontal hole 47a to the tip end surface of the large diameter piston portion 37b. An oil passage 47 is provided, and a radial oil groove 48 for preventing the vertical hole 47b from being closed by the auxiliary piston 38 is provided at the distal end surface of the large diameter piston portion 37b. The oil passage 47 always communicates between the inlet oil chamber 44 and the outlet oil chamber 46. Therefore, when the valve plate 42 is opened, the inlet port 34 communicates with the inlet oil chamber 44 so that the inlet port 34 and the outlet port 35 communicate with each other.

  In the above, the opening area of the inlet port 34 to the first cylinder bore 31, that is, the pressure receiving area A of the valve plate 42 when the inlet port 34 is closed, and the pressure receiving area D of the auxiliary piston 38 facing the auxiliary oil chamber 49 are mutually. Set equal.

  Thus, since the suction valve 30 is configured mechanically, it can contribute to the cost reduction of the brake hydraulic control device for the vehicle.

Next, the operation of this embodiment will be described.
[Normal brake]
During normal braking in which each wheel is not likely to lock, each cut valve 14 is demagnetized and opened, each inlet valve 5a-5d is also demagnetized, and each valve is open. The outlet valves 6a to 6d are in a demagnetized state and are closed. The hydraulic pump devices 8A and 8B are in a stopped state. Now, when the master cylinder M is operated by depressing the brake pedal P, the output hydraulic pressure from the first output port 1a is the first input oil passage 2a, the cut valve 14, the first and second inlet valves 5a, 5b and the first. , Are supplied to the left front wheel wheel brake Ba and the right rear wheel wheel brake Bb via the second output oil passages 12a and 12b, and operate them. The output hydraulic pressure from the second output port 1b is for the right front wheel via the second input oil passage 2b, the cut valve 14, the third and fourth inlet valves 5c and 5d, and the third and fourth output oil passages 12c and 12d. It is supplied to the wheel brake Bc and the wheel brake Bd for the left rear wheel and operates them.

  In this case, the output hydraulic pressures of the first and second output ports 1a and 1b are transmitted to the inlet port 34 and the auxiliary port 36 of the suction valve 30 via the first and second suction oil passages 15a and 15b. When the transmission oil pressure rises above a predetermined value, due to the difference between the pressure receiving area B facing the inlet oil chamber 44 of the small diameter piston portion 37a and the pressure receiving area C facing the outlet oil chamber 46 of the large diameter piston portion 37b, The thrust by the hydraulic pressure to the inlet oil chamber 44 side acting on the valve piston 37 overcomes the set load of the valve opening spring 43 that biases the valve piston 37 toward the outlet oil chamber 46 side, and the valve piston 37 is moved to the inlet oil chamber 44 side. 3 and the valve plate 42 is seated on the inner end face of the first cylinder bore 31, so that the inlet port 34 is closed. Once the inlet port 34 is closed, even if the output hydraulic pressure of the master cylinder M subsequently increases, the pressure of the auxiliary port 36 increases simultaneously with the increase, so the pressure of the auxiliary port 36 and the pressure of the outlet oil chamber 46 are increased. The auxiliary piston 38 moves to a contact position with the large-diameter piston portion 37b. Thus, as described above, the pressure receiving area A of the valve plate 42 facing the inlet port 34 and the pressure receiving area D of the auxiliary piston 38 facing the auxiliary oil chamber 49 are equal to each other. The pressing force to the auxiliary piston 38 by the hydraulic pressure of the auxiliary port 36 is balanced, and as a result, the closed state of the inlet port 34 by the valve plate 42 is maintained. Accordingly, since the output hydraulic pressure of the master cylinder M hardly acts on the suction side of each plunger pump 8 constituting the hydraulic pump devices 8A and 8B, the burden on the seal member of each plunger 8 is reduced and the service life thereof is extended. be able to.

Next, if the master cylinder M is returned to the non-operating state in order to release the operation of the wheel brakes Ba to Bd, the pressure of the auxiliary port 36 is greatly reduced from the pressure of the outlet oil chamber 46. Retreat to the 36 side to reduce the pressure in the outlet oil chamber 46. As a result, the inlet oil chamber acting on the valve piston 37 due to the difference between the pressure receiving area B facing the inlet oil chamber 44 of the small diameter piston portion 37a and the pressure receiving area C facing the outlet oil chamber 46 of the large diameter piston portion 37b. The thrust due to the hydraulic pressure toward the side 44 decreases from the set load of the valve opening spring 43, and the valve piston 37 can return to the initial position of opening the valve plate 42 by the set load of the valve opening spring 43.
[Anti-lock control]
When the wheel is about to enter the locked state at the time of braking, the electronic control unit 20 activates the inlet valve corresponding to the wheel that is about to be locked among the first to fourth inlet valves 5a to 5d. While closing the valve, the outlet valve corresponding to the wheel among the first to fourth outlet valves 6a to 6d is excited and opened. Then, a part of the hydraulic pressure of the wheel brake corresponding to the wheel is absorbed into the first reservoir 9a or the second reservoir 9b through the corresponding outlet valve and the corresponding decompression oil passages 7a and 7b, and the wheel The brake hydraulic pressure is reduced.

  In order to keep the wheel brake hydraulic pressure constant, the inlet valves 5a to 5d corresponding to the wheel brake may be excited and closed, and the outlet valves 6a to 6d may be demagnetized to be closed. When the brake hydraulic pressure is increased, the inlet valves 5a to 5d may be demagnetized and opened, and the outlet valves 6a to 6d may be demagnetized and closed. By controlling in this way, braking can be performed efficiently without locking the wheels.

  During such anti-lock control, the electronic control unit 20 energizes the electric motor 17 to drive the hydraulic pump devices 8A and 8B, and reciprocates the plungers of the plunger pumps 8 so as to reciprocate the first and second reservoirs 9a and 9b. Is absorbed through the first and second pressure reducing oil passages 7a and 7b, and is recirculated to the first and second input oil passages 2a and 2b through the pressure increasing oil passages 11a and 11b. By this recirculation, an increase in the depression amount of the brake pedal P due to the absorption of the hydraulic oil in the reservoirs 9a and 9b is suppressed.

During this time, each of the suction valves 30 has a normal brake while the hydraulic pump devices 8A and 8B are recirculating the hydraulic oil from the first and second reservoirs 9a and 9b to the first and second input oil passages 2a and 2b. Similarly to the time, the valve closed state is maintained by the output hydraulic pressure of the master cylinder M, and the suction oil passages 15a and 15b are shut off. As a result, the working oil can be efficiently pumped from the first and second reservoirs 9a and 9b.
[Brake assist]
When the master cylinder M is actuated by depressing the brake pedal P, the hydraulic sensor 21 detects the master cylinder output hydraulic pressure and outputs a signal corresponding thereto to the electronic control unit 20. The output boost speed of M is calculated, and when the boost speed exceeds a specified threshold value, it is determined that the brake is suddenly operated, the electric motor 17 is operated, and the first and second hydraulic pump devices 8A and 8B are operated. While driving, the cut valve 14 is excited to close. As a result, the first and second hydraulic pump devices 8A and 8B pass the hydraulic pressure of the master cylinder M in the first and second input oil passages 2a and 2b through the first and second suction oil passages 15a and 15b and the suction valve 30. Inhalation, the pressure is increased, and pressure is supplied from the pressure increase oil passages 11a and 11b to the wheel brakes Ba to Bd through the opened inlet valves 5a to 5d. can do.

  The operation of the suction valve 30 during this period will be described. During normal braking before the sudden braking operation state is determined, in the suction valve 30, the valve piston 37 keeps the valve plate 42 closed as described above. Since the pressure receiving area A of the valve plate 42 facing the inlet port 34 is equal to the pressure receiving area D of the auxiliary piston 38 facing the auxiliary oil chamber 49, the pressure applied to the valve plate 42 by the hydraulic pressure of the inlet port 34 is The pressing force to the auxiliary piston 38 by the hydraulic pressure of the auxiliary port 36 is balanced.

  Therefore, when it is determined that the brake is suddenly operated and the cut valve 14 is closed and the first and second hydraulic pump devices 8A and 8B are operated, the suction pressures of the hydraulic pump devices 8A and 8B are set to the suction valves 30. Since it is transmitted to the outlet port 35 and the outlet oil chamber 46 and the inlet oil chamber 44 are depressurized, the pressure receiving area B facing the inlet oil chamber 44 of the small diameter piston portion 37a and the outlet oil chamber 46 of the large diameter piston portion 37b are faced. Due to the difference from the pressure receiving area C, the thrust by the hydraulic pressure acting on the inlet oil chamber 44 acting on the valve piston 37 is more than the set load of the valve opening spring 43 urging the valve piston 37 toward the outlet oil chamber 46. As the valve piston 37 becomes smaller, the valve piston 37 moves in the direction of the biasing force of the valve opening spring 43, that is, toward the outlet oil chamber 46, opens the valve plate 42, and introduces the hydraulic pressure of the master cylinder M from the inlet port 34 to the inlet oil chamber 44. And the entrance To replenish the pressure in the vacuum portion of the chamber 44 and the outlet fluid chamber 46. As soon as the replenishment is performed, the thrust by the hydraulic pressure to the inlet oil chamber 44 acting again on the valve piston 37 overcomes the set load of the valve opening spring 43, and the valve piston 37 is moved to the inlet port 34 side. 42 closes the inlet port 34.

  The above operation is repeated each time the suction pressure of the hydraulic pump devices 8A and 8B acts on the outlet port 35 of the suction valve 30, whereby the pressure of the inlet and outlet oil chambers 44 and 46, that is, the hydraulic pump devices 8A and 8B. Regardless of the output hydraulic pressure of the master cylinder M, the difference between the pressure receiving area B facing the inlet oil chamber 44 of the small diameter piston portion 37a and the pressure receiving area C facing the outlet oil chamber 46 of the large diameter piston portion 37b, In addition, the valve opening spring 43 is controlled to a constant value determined by the set load. As a result, the pressure fluctuations in the suction oil passages 15a and 15b and the output ports 1a and 1b of the master cylinder M due to the suction action of the hydraulic pump devices 8A and 8B are suppressed to a small level, and the brake pedal P generated by the pressure fluctuations is reduced. The vibration can be effectively reduced and the operation feeling of the brake pedal P can be improved.

Each of the hydraulic pump devices 8A and 8B is composed of a plurality of plunger pumps 8, 8... That are interlocked and connected to each other with the suction and discharge timings shifted at equal intervals, and the total discharge and suction pressures of the hydraulic pump devices 8A and 8B. Since the orifice 10 and the damper 26 are connected to the suction oil passages 15a and 15b to attenuate the pressure fluctuation generated in the suction oil passages 15a and 15b, the vibration of the brake pedal P is reduced. Further prevention can be achieved.
[Automatic brake control 3 (vehicle running attitude control)]
When the vehicle is turning left, for example, the output signals of the rudder angle sensor 23 and the yaw rate sensor 24 do not correspond to each other, and the electronic control unit 20 determines that the vehicle is about to turn left, for example, excessively. In order to correct the direction, the control unit 20 operates the electric motor 17 to drive the first and second hydraulic pump devices 8A and 8B, and the cut valve 14, the first inlet valve 5a and the fourth inlet valve. Energize 5d to close the valve. As a result, the first and second hydraulic pump devices 8A and 8B are operated, so that the hydraulic oil of the master cylinder M is supplied from the first and second output ports 1a and 1b to the first suction oil passage 15a and the opened suction valve. 30 and is supplied only to the right front wheel brake Bc and the right rear wheel brake Bb through the pressure boosting oil passages 11a, 11b, the second and third inlet valves 5b, 5c, and the master cylinder of the hydraulic oil. Since the flow to the M side is blocked by the cut valve 14 in the closed state, the right front wheel brake Bc and the right rear wheel brake Bb are operated so that the vehicle running posture corresponds to the steering angle. Can be corrected.

  In order to correct the vehicle direction to the left side, the second inlet valve 5b and the third inlet valve 5c are energized and closed in the opposite manner, and the first and second hydraulic pump devices 8A and 8B are discharged. The hydraulic pressure is supplied only to the left front wheel wheel brake Ba and the left rear wheel wheel brake Bd through the first and fourth inlet valves 5a and 5d, and they are operated.

Further, whether the vehicle is turning right or straight, the traveling posture of the vehicle is controlled by the same action as described above.
[Automatic brake control 1 (traction control)]
When the master cylinder M is not operating, the suction valve 30 is in an open state. For example, when the front wheel that is the driving wheel is likely to run idle when the vehicle starts, the electronic control unit 20 calculates the rotation difference between the front wheel and the rear wheel from the signal sent from the wheel speed sensor 22 of each wheel, and the rotation difference. Is determined to be in the idling state, the cut valve 14, the second inlet valve 5b and the fourth inlet valve 5d are excited and closed, and the electric motor 17 is operated to operate the first and second valves. The hydraulic pump devices 8A and 8B are driven, the hydraulic oil of the master cylinder M is sucked from the first and second output ports 1a and 1b through the first suction oil passage 15a and the opened suction valve 30, and the pressure increase oil passage 11a, 11b, the first and third inlet valves 5a, 5c are supplied to the left and right front wheel brakes Ba, Bc, and the flow of the hydraulic fluid to the master cylinder M side is caused by the closed cut valve 14 Since stop, left and right front wheel brake Ba, by operating the Bc, can automatically prevent the front wheel of the idling.

At that time, when the oil pressure of the front wheel brakes Ba and Bc is kept constant, the inlet valves 5a to 5d are energized and closed, and the outlet valves 6a to 6d are demagnetized as in the anti-lock control. In order to increase the brake hydraulic pressure, the inlet valves 5a to 5d are demagnetized and opened, and the outlet valves 6a to 6d are demagnetized and returned to the closed state. Thus, it is possible to prevent the front wheels from slipping and to control the driving torque appropriately.
[Automatic brake control 3 (vehicle rear-end collision prevention control)]
While the vehicle is traveling, the radar 25 detects the relative speed and distance with respect to the preceding vehicle, and when the electronic control unit 20 determines that there is a possibility of a rear-end collision based on the detected information, the electronic control unit 20 activates the electric motor 17. Then, the first and second hydraulic pump devices 8A and 8B are driven and the cut valve 14 is excited to close. As a result, the first and second pump device chambers 38 and 39 of the first and second hydraulic pump devices 8A and 8B are operated. In this case, the first and second inputs are particularly activated by the operation of the second pump device chamber 39. The hydraulic pressure of the master cylinder M in the oil passages 2a and 2b is sucked through the first and second suction oil passages 15a and 15b and the opened suction valve 30, and the pressure is increased to open the pressure increase oil passages 11a and 11b. Since the pressure is fed to the wheel brakes Ba to Bd through the state inlet valves 4a to 4d, they can be automatically operated to prevent a rear-end collision.

  When the master cylinder M is operated by depressing the brake pedal P during the automatic brake control 1 to 3 described above, the hydraulic pressure sensor 21 receives the output hydraulic pressure and inputs the detection signal to the electronic control unit 20. Upon receiving the signal, the electronic control unit 20 stops the operation of the electric motor 17 in order to prohibit the automatic brake control, the cut valve 14 is normally opened, and all the inlet valves 5a to 5d are normally opened. All the outlet valves 6a to 6d are returned to the normal closed state. Accordingly, as in the case of the normal brake, the output hydraulic pressure of the master cylinder M is supplied to all the wheel brakes Ba to Bd and can be operated.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention. For example, the hydraulic pump device can be constituted by a single plunger pump, and the oil passage 47 communicating between the inlet oil chamber 44 and the outlet oil chamber 46 can be provided in the body 3 a of the modulator 3. The present invention is also applicable to a rear wheel drive vehicle.

The hydraulic circuit diagram of the brake device for front-wheel drive type vehicles provided with the brake oil pressure control device of the present invention. The expanded longitudinal cross-sectional view of the suction valve in the valve opening state in the said hydraulic circuit. FIG. 3 is a view corresponding to FIG. 2 showing a closed state of the suction valve.

Explanation of symbols

Ba to Bd ··· wheel brake M ··· master cylinders 2a and 2b ··· input oil passage 4 ··· brake control valve means 8A and 8B · · · hydraulic pump devices 9a and 9b ··· ··· Reservoir 11a, 11b · · Pressure oil passage 12a, 12b · · · Output oil passage 14 ··· Cut valve 15a, 15b · · · Suction oil passage 30 · · · Suction valve 34 · · · Inlet port 35 · · · Outlet Port 37 ... Valve piston 37a ... Small diameter piston part 37b ... Large diameter piston part 42 ... Valve part (valve plate)
43 ... Valve opening spring 44 ... Inlet oil chamber 45 ... Outlet oil chamber 45 ... Atmospheric pressure chamber 46 ... Outlet oil chamber 49 ... Auxiliary oil chamber

Claims (2)

An input oil passage (2a, 2b) connected to the master cylinder (M), a cut valve (14) for opening and closing the input oil passage (2a, 2b), and an output oil passage (12a) connected to the wheel brakes (Ba to Bd) To 12d), reservoirs (9a, 9b) capable of absorbing hydraulic oil, and the input oil passages (2a, 2b) and the output oil passages (12a to 12d) and the output oil passages (12a to 12d) And the pressure-increasing state that shuts off the reservoirs (9a, 9b), the input oil passages (2a, 2b) and the output oil passages (12a-12d) are shut off, and the output oil passages (12a-12d) and the reservoirs (9a, 9b) 9b) Brake hydraulic pressure capable of switching between a pressure-reduced state communicating with each other and a hydraulic pressure holding state for blocking both the input oil passages (2a, 2b) and the reservoirs (9a, 9b) and the output oil passages (12a-12d). Control valve means (4) and Hydraulic pump that sucks hydraulic oil absorbed in the reservoirs (9a, 9b) through the decompression oil passages (7a, 7b) and sucks hydraulic oil from the master cylinder (32) through the suction oil passages (15a, 15b). (8A, 8B), a suction valve (30) for opening and closing the suction oil passage (15a, 15b), and a hydraulic pump (8A, 8B) to the input oil passage (2a, 2b) downstream of the cut valve (14) Brake hydraulic control device for a vehicle, comprising a pressure boosting oil passage (11a, 11b) for inducing the discharge hydraulic pressure and an electronic control unit (60) for controlling the brake hydraulic control valve means (4) and the cut valve (14) In
The suction valve (30) is closed when the output hydraulic pressure of the master cylinder (M) is received, and when the suction pressure of the hydraulic pump device (8A, 8B) is received in the closed state, the suction pressure is kept constant. A brake hydraulic pressure control device for a vehicle, characterized in that the brake hydraulic pressure control device is configured as a normally open type that opens and closes the suction oil passages (15a, 15b) so as to control. The brake hydraulic control device for a vehicle according to claim 1,
The suction valve (30) is a stepped valve piston (37) comprising a valve housing (3a) and a small diameter piston portion (37a) and a large diameter piston portion (37b) fitted in the valve housing (3a). ) And an auxiliary piston (38) fitted in the valve housing (3a) and abutting against the end face of the large-diameter piston portion (37b). The valve housing (3a) includes a small-diameter piston portion (37a ) And an inlet oil chamber (44) in which an inlet port (34) connected to the upstream side of the suction oil passages (15a, 15b) opens, the large-diameter piston portion (37b) and the auxiliary piston (38). ) And an outlet oil chamber (46) in which an outlet port (35) communicating with the inlet oil chamber (44) and downstream of the suction oil passages (15a, 15b) is opened. The auxiliary piston (38) faces the outer end and forms an auxiliary oil chamber (49) to which the upstream side of the suction oil passages (15a, 15b) is connected. The small diameter piston portion (37a) has a valve A valve portion (42) for closing the inlet port (34) when the piston (37) moves to the inlet oil chamber (44) side is provided, while the valve piston (37) is provided with the valve portion (42). When the valve part (42) closes the inlet port (34), it faces the inlet port (34) of the valve part (42). A brake hydraulic control device for a vehicle, wherein the pressure receiving area (A) and the pressure receiving area (D) of the auxiliary piston (38) facing the auxiliary oil chamber (49) are set equal.

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