JPS6141654A - Propulsion controller for vehicles - Google Patents

Abstract

PURPOSE:To aim at improvements in accelerability as well as to secure the stable travelability of a car, by installing a propulsion controlling device, which controls a boost pressure control valve and a hydraulic control valve, in an electronic control unit. CONSTITUTION:When a brake pedal 1 is operated, braking displacement of a push rod 1a is fed to an electronic control unit RCU from a displacement sensor 14, whereby at the ECU, boost pressure commensurate to this displacement is made to be produced inside a boost chamber 13e, and a 3-port 3 position selector valve 15 is moved to a third position. If so, brake fluid out of a pump is fed to the boost chamber 13e, making pressure inside the boost chamber 13e go up. This pressure is monitored with a sensor 13b, and pressure commensurate to the displacement is calculated inside the ECU, and if a fact that it reaches to the pressure is judged from pressure sensor output, the valve 15 is moved to a second position, thus pressure inside the boost chamber 13e is kept up. And, if one's foot comes off the pedal 1, pressure commensurate to output of the sensor 14 is set at the ECU, controlling motion of the valve 15, so that boost pressure commensurate to a pedal stroke is securable.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a propulsion control device for a vehicle, and in particular, it is capable of stably running a vehicle by suppressing excessive slip that occurs during starting and acceleration. The present invention relates to a vehicular propulsion control device that can secure and improve acceleration performance.

[Prior Art] Conventionally, as shown in Japanese Patent Application Laid-Open No. 58-16948, there has been a vehicle that controls the brake fluid pressure according to the slip state of the drive wheels when the vehicle accelerates or starts to suppress the slip of the drive wheels. Promotion 2111 all! Various locations have been proposed.

[Problems that B Ming attempts to solve] By the way, vehicle propulsion control devices are often installed together with normal brake hydraulic devices, but conventional vehicle propulsion control devices are equipped with a dedicated brake system. A hydraulic pressure source and a dedicated brake fluid pressure control valve are required, requiring major modifications to the normal brake fluid pressure IIJII device, making the valve structure complicated and requiring a large installation space. It gets heavy. There were problems such as:

The present invention has been made by focusing on the problems of the prior art, and the present invention provides a vehicle propulsion control device that can be constructed by making slight modifications to a normal brake fluid pressure control device. is intended to provide.

[Means for Solving the Problems] As shown in FIG. 1, the present invention, which has been made to solve the above-mentioned problems, includes a slip detection means that generates a signal according to the slip state of a wheel. an electronic control device C that performs a slip determination based on a signal from the means and generates a brake fluid pressure control signal; 1. j
a brake fluid pressure control valve e that switches and controls the brake fluid pressure of the brake fluid at least between a pressure increase mode and a pressure decrease mode; and a fluid pressure booster h that increases force on the master cylinder 9.
and an auxiliary pressure Iff for supplying brake pressure fluid to the hydraulic pressure booster h during brake operation. In the vehicle propulsion IIJIllVLH, the electronic control device FC includes a displacement sensor a that detects a depression state of the brake pedal.
When it is determined that the brake pedal k is not depressed based on the signal from A propulsion control means d is provided for outputting a brake hydraulic valve control signal in order to switch to the boost pressure, and a boost pressure control means d for switching the boost pressure in the hydraulic booster h to each mode of pressure increase, pressure decrease, and hold according to the boost pressure control signal. The control valve stand is connected to the hydraulic pressure booster h and the auxiliary pressure m.
t.

[Embodiment N] Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 2 is a hydraulic circuit diagram showing a first embodiment of the present invention,
It is equipped with an anti-skid control device as well as a vehicle propulsion control device. In addition, rear wheel W2. L and W2R are the driving wheels.

In FIG. 2, a brake pedal 1 is capable of pressing a primary piston 2a of a master cylinder 2 via a hydraulic pressure booster 13. Inside master cylinder 2,
Secondary pistons 2b pressed by compression coil springs 2d and 2g are provided on both sides, and chambers 2r and 2c are formed. The chamber 2C communicates with the wheel cylinders 4L14R of the left and right rear wheels W2L and W2H, and the chamber 2f communicates with the left and right front wheels WI.
L.

It communicates with WIR's wheel cylinders 3L and 3R.

Further, the chamber 2C and the boat 2h close to the brake piston 2a and the boat 21 close to the secondary piston 2b of the chamber 2f communicate with the reservoir 12. Left and right rear wheels W
Chamber 2c that becomes the brake fluid supply cylinder to 2L%W2R
is a 3-bottom 2-position switching valve 10R, a check valve 6R, 12 check valves 9L, 9R, and 2 2-bottom 2-position switching valves 7L1.
7R through two wheel cylinders 4L each.

It is connected to 4R.

That is, the chamber 2C, which serves as a cylinder for supplying brake fluid to the left and right rear wheels, is communicated with one boat of the 3-bot, 2-position switching valve 10R by a pipe connected to the boat 2k, and is further connected to another boat. The pipe τ is branched into two, and connected to the left and right rear wheel cylinders 4 via two 2-point, 2-position switching valves 7L and 7R, respectively.
It is connected to L and 4R. Note that a conduit having a check valve 6R whose forward direction is directed toward the wheel cylinders 4L and 4R is connected in a throttle row to the conduit having the switching valve 10R.

On the other hand, the chamber 2f, which serves as a cylinder for supplying brake fluid to the left and right front wheels W1L and WlR, is connected to the wheel cylinders 3L and 3R in the same manner as the chamber 2c.

In addition, 2-bottom 2-position switching valves 7L, 7R, and 5L.

5R and each wheel cylinder 4L, 4R, 3L, 3R, and a 2-bot 2-position switching valve 18L is branched from the pipe line communicating with the reservoir 12.
118R, 19L, and 19R are connected.

The boost chamber 1 3 e of the hydraulic booster 13 is communicated with the reservoir 12 and the accumulator 17 via a 3-point, 2-position, 1-position switching valve 15 . That is, the hydraulic booster 13
The boat 13a is connected to one boat of the 3-bot 2-position switching valve 15, and the other two boats are connected to a pipe line going to the reservoir 12 and a pipe line going to the accumulator 17, respectively, and the switching valve 15 is The position where the boat 13a communicates with the accumulator 17 and the position where the boat 13a communicates with the reservoir 12
It is possible to switch between a position where all ports are communicated with and a position where all ports are blocked. In addition, the boat 1 of the hydraulic booster 13
3. c are communicated with three-bottom, two-position switching valves 10L and 10R via check valves 11L and 11R, respectively.

Furthermore, the brake fluid stored in the reservoir 12 is
It is connected to a motor-driven hydraulic pump 16 via a strainer on the suction side, and the discharge side is connected to an accumulator 17, so that the discharge pressure is 175 to 200 kmMcn! is maintained. This discharge side is connected to the hydraulic booster 13 via the 3-bot 2-position switching valve 15 as a boost pressure control valve as described above.
An accumulator 17 is connected roughly between the discharge side and the three-bottom, two-position switching valve 15.

In addition, the three boats of the 3-point 2-position switching valve 10R each have a master cylinder 2.2-point 2-position switching valve 7L,
7R, is in communication with the hydraulic booster 13, and is connected to the electronic control unit f.
The three-point/two-position switching valves 7L and 7R are communicated with the master cylinder 2 or the hydraulic booster 13 in accordance with a signal from the LIT (ECU) 74 (not shown in FIG. 2). The 2-point 2-position switching valves 18L and 18R correspond to the wheel cylinders 4m and 4R, respectively, and the 2-point 2-position switching valve 7.
A conduit whose one end is connected to the conduit connecting L and 7R and whose other end is connected to the conduit communicating with the reservoir 12 is shut off or communicated based on a signal from the ECU.

On the other hand, the 3-bottom 2-position switching valve 10L also communicates with the master cylinder 2, the 2-bottom 2-position switching valve 5L, 5R, and the hydraulic booster 13, respectively, as in the case of 1oR, and switches according to the signal from the ECU 74. The valve 10L is communicated with the master cylinder 2 or the hydraulic booster 13. Switching valve 19L,
As for the switching valve 19R, the switching valve 5L, the wheel cylinder 3L, and the switching valve 5 are used in the same way as the switching valve 18L and 118R.
A pipe line that communicates between R and the wheel cylinder 3R and a pipe line connected to the reservoir 12 are communicated or cut off.

That is, a signal from the ECU 74 is applied to the switching valve 10R, which is in the second position, and each switching valve 7L, 7R,
When 18L and 18R are not turned on and are in the first position, wheel cylinders 4L and 4R communicate with hydraulic booster 13. When the signal is not applied, the switching valve 10R
is in the first position, communication between the wheel cylinders 4L, 4R and the hydraulic pressure booster 13 is cut off, and the wheel cylinders 4L, 4R are communicated with the boat 2k of the master cylinder 2. The switching valve 10L can be switched in the same manner.

Next, the Ti Iiba signal system will be explained.

First, as sensors, a pressure sensor 13b for measuring the pressure in the boost chamber 13e and a displacement sensor 14 for measuring the displacement of the bushing rod 1a are wired in the boost chamber 13e of the hydraulic pressure booster 13, and electronics (not shown) are wired. It is connected to a control unit (hereinafter referred to as ECU). Further, the accumulator 17 is connected to the ECIJ with a pressure switch that outputs a signal corresponding to the upper and lower limit set values of the hydraulic pressure in the accumulator, that is, the discharge pressure.

Furthermore, although not shown in Fig. 2, the rear wheels (drive wheels)
The front wheels (driven wheels) are each provided with a driving wheel speed sensor and a driven wheel speed sensor.

Next, the electronic O1I device (ECU) 74 will be explained. Regarding the third factor, 70 is a driving wheel speed sensor that detects the driving wheel speed, 72 is a driven wheel speed sensor that detects the driven wheel speed, 14 is a displacement sensor that detects the depression state of the brake pedal, and 13b is a hydraulic A pressure sensor 74 detects the hydraulic pressure in the pressure boost, and 74 performs arithmetic processing to determine slip based on the slip state of the wheel.
The electronic control unit (EC (J) 75, which consists of a microcomputer that outputs the l signal, controls the brake fluid pressure applied to the wheel cylinder by the signal from the ECLJ.
This is a hydraulic pressure control valve. In E174, 76 is a central processing unit (hereinafter referred to as CPU) that performs calculations such as slip determination, and 77 is a speed sensor 70.
78 is a speed sensor 70 that counts the number of pulses.
．． 72, an input port for inputting signals from the displacement sensor 14 and the pressure sensor 13b; 79, a random access memory for temporarily storing calculation results, etc.; hereinafter referred to as RAM; ), 8
0 is a read-only memory (hereinafter referred to as ROM) that stores calculation programs and 1llllII data, 82
is an output boat that outputs control signals to the hydraulic pressure control valve 75, the drive motor 20, and the boost pressure control valve 83.

The εCLI 74 detects the running state from the speed signals of the speed sensors 70 and 72, makes a slip judgment according to the running state, and when a slip occurs, controls the hydraulic pressure control valve 75 to
The output boat 82 outputs a control signal according to the slip state, controls the brake fluid pressure applied to the wheel cylinder 4L14R of the drive wheel, and instructs the output boat 82 to suppress the slip.

Furthermore, when it is determined that the brake pedal is not depressed based on the signal from the displacement sensor that detects the depressed state of the pre-k pedal, and when it is determined that the slip of the drive wheels is equal to or greater than a predetermined value, the ECU 74 controls the hydraulic pressure. Propulsion control means that outputs a boost pressure control signal to increase and maintain the boost pressure in the booster at a predetermined level, and also outputs a brake fluid pressure valve control signal to switch the brake fluid pressure in the wheel cylinder of the driven wheel to a holding mode. is provided.

In the above configuration, the drive wheel speed sensor 70. The driven wheel speed sensor 72 corresponds to a slip detection means, and the brake hydraulic pressure control valve (hereinafter simply referred to as a hydraulic pressure control valve) 75 includes the switching valves 5L15R17L, 7R, 10L11 of the above embodiment.
The boost pressure υ control valve 83 corresponds to the switching valve 15, and the auxiliary hydraulic pressure source f corresponds to the accumulator 17 and the hydraulic pump 16.

The operation of this embodiment will be explained below with reference to FIG.

(1) During normal braking, the driver tries to stop the car (C1 brake pedal 1)
When the user steps on the button, the displacement sensor 14 sends the displacement of the bushing rod 1a to the ECU. Then, the ECU moves the three-bottom, three-position switching valve 15 to the third position in order to generate boost pressure in the boost air 13e according to the displacement and to function as a booster groove. Then, the discharge pressure of the pump, that is, the brake fluid accumulated in the accumulator 17, is sent into the boost chamber 13e, increasing the pressure inside the boost chamber 13e. This pressure is monitored by the pressure sensor 13b, and the EC
The pressure according to the displacement is calculated in the IJ, and if it is determined from the pressure sensor output that the pressure has been reached, the 3-point/3-position switching valve 15 is moved to the second position, and boost;
3, the pressure inside is maintained. Then, when you try to release the brake by lifting your foot off the pedal 1, the pressure corresponding to the output of the displacement sensor 14 is calculated in the same way, and the 3-bottom 3
The position switching valve 15 is returned to the first position, and the boost chamber 13
The brake fluid in e is returned to the reservoir 12 via the 3-boat 3-position switching valve 15. In this way, the pressure according to the output of the displacement sensor 14 is calculated and set by ECLI, and
It is possible to switch the position switching valve 15, feed back the pressure with the pressure sensor 13b, control the movement of the 3-point 3rd position switching valve 15, and obtain the boost pressure of the hydraulic pressure set in response to the pedal stroke. can. That is, switching valve 1
5 can control the boost pressure in each mode of pressure increase, pressure decrease, and hold according to the signal from the ECU.

Here, even if the pump fails and cannot generate boost pressure, the primary piston 2a and secondary piston 2b can be moved by the force of directly pressing the brake pedal 1, so it is similar to a normal vacuum booster. A failsafe is possible.

Next, pressure transmission to the wheel cylinder will be explained below.

When the driver depresses the brake pedal 1, the above-mentioned hydraulic boost mechanism is activated to reduce the pedal depressing force.

Then, the primary piston 2a pressed by the bushing rod 1a roughly pushes the secondary piston 2b, and from the time when the boats 2h and 2i are closed, '
! 20.2f of brake fluid is delivered from the master cylinder. In the following explanation, the chamber 2f is divided into two systems: the front wheel, and the chamber 2C is for the rear wheel, but since the explanation for the rear wheel is almost the same as for the front wheel, the following will explain only the front wheel as a representative. do.

Now, the brake fluid pushed out from the chamber 2f passes through both the 3-bottom, 2-position switching valve 10L and the check valve 6L, and merges into one, and the 2-bottom, 2-position switching valve 5L, 5R. , since it is in the first position, passes through this 2-bot 2-position switching valve and the wheel cylinder 3L.

3R is reached, the pressure in the wheel cylinder 3L13R is increased, and the brake is applied. To lower the pressure in the wheel cylinder, release the brake pedal 1.The brake fluid in the wheel cylinder is reduced by a 2-point 2-position switching valve 5m.

5R13 bottom 2 position switching valve 10L path and check valve 8
Return to room 2f via routes L and 8R.

Further, the pump side will be explained below.

The ON/OFF of the pump 16 is determined by ECIJ based on the input from the pressure switch, and when the pressure becomes lower than a certain set pressure,
A current is applied to the drive motor 20 of the pump 16 to operate the pump, and when a certain set pressure is reached, the current is turned off. Therefore, the accumulator 17 always has a pressure within a certain range (e.g. 17
Brake fluid pressure is accumulated between 5 and 200 km Mcni.

(11) Slip Control Next, the operation of slip control when the drive wheels slip during starting, acceleration, turning, etc. will be explained. In this case, a case will be described in which the vehicle is a rear wheel drive vehicle, that is, the rear wheels are driving wheels and the front wheels are driven wheels.

If excessive slip occurs in the drive wheels, the ECU receives a signal from the vehicle speed sensor, detects the slip in the drive wheels, and activates the 3-point 3-position switching valve 15.2 to suppress the slip. Mainly controls the two-position switching valve 5L15R. In order to apply the brakes only to the driving wheels in the event of a slip, the two-bottom, two-position switching valve 5L1 is installed to prevent brake pressure from being applied to the wheel cylinders 3L and 3R on the driven wheels.
After setting 5R to the second position and cutting the pressure of the empty 2f of the master cylinder 2, move the wheel cylinder 4 on the driving wheel side,
The 3-point, 3-position switching valve 15 is controlled so that brake pressure is applied to 4R. That is, chamber 2 of master cylinder 2
In order to generate pressure in C, the pressure in the boost chamber 13e is increased. Therefore, by setting the 3-bottom 3-position switching valve 15 to the third position, the high-pressure fluid in the accumulator 17 is transferred to the boost chamber 1.
3e to generate brake pressure. In this case, E
The CU detects the pressure in the boost chamber 13e with a pressure sensor 13b, and adjusts the pressure in the boost chamber 13e to a pressure suitable for the slip state.
Control is performed by appropriately switching the button 3-position switching valve 15.

As a result, the brakes are applied to the drive wheels, reducing slippage. Further, since no brake is applied to the driven wheels, the vehicle is not decelerated.

Next, the detailed operation of the slip control portion will be explained with reference to the flowchart shown in FIG.

In ECLI, when slip control processing is started, the driven wheel speed v■ is first calculated in step 100, and then the driving wheel speed VW is calculated in step 101, and when the brake pedal is not depressed, Proceeding to step 103, a -slip determination level vT is created. Here, the driven wheel speed corresponding to the vehicle body speed is multiplied by (K-1, 1 to 2)
Then, the predetermined speed Vo (vo-0~25km/h
) to create a slip judgment level VT. That is, V−r −K
TE a 'O, ko 17) By simply changing the V position and reducing the driving wheel speed VW to 1ull, the slip ratio can be suppressed to the optimum value. Then, in step 104, the drive wheel speed VW and the slip determination level vT are compared as described above, and if it is determined that there is a slip when yw>v, the process proceeds to step 105, where the 2-point, 2-position switching valve 5L15R is turned ON to set it to the second position, that is, the shut-off state, and the pressure of the empty 2f of the master cylinder 2 is applied to the wheel cylinders 3L, 3.
After making sure that it does not apply to R, in step 106, the 3-bot 3-position switching valve 15 is operated so that the pressure P8 in the boost chamber 13e becomes a predetermined value lli[Pl (for example, 9/aA to P'+-30). control the rear wheel cylinders 4L, 4
After sending brake fluid to R and applying the brakes to the rear wheels, the process returns to step 100.

On the other hand, if it is determined in step 104 that VW≦■□ and there is no slip, the process proceeds to step 107, where the boost pressure PB is set to atmospheric pressure (÷0).
Control of the position switching valve 15 is started, and in step 108 it is determined whether the boost pressure P8 has become atmospheric pressure, that is, P, ÷0. Turn off the cutoff valves 5L and 5R and
On the other hand, when P is not divided by 0, that is, when the pressure is higher than atmospheric pressure, the two-point/two-position switching valves 5m and 5R are left as they are, and the process returns to step 10o. Further, if it is determined in step 102 that the brake pedal is depressed, the process proceeds to step 110, and the anti-skid III
III is performed and the process returns to step 100.

(iii) Anti-skid 113111 Next, the operation during anti-skid control will be explained. Wheel cylinders 3L and 3R operate in the same manner as during normal braking as described above.
, 4L, 4R increases and when the wheels are about to lock, the EC receives a signal from the wheel speed detection sensor.
LI detects the locked state and the 3-point/2-position switching valve 10
L.

10R, 2-bottom 2-position switching valve 5L, 5R, 7L, 7R
118L, 18R, 119L, and 19R are controlled to reduce the pressure in wheel cylinders 3L, 3R, 4L, and 4R, and suppress the wheel slip rate to approximately 20%.

Conventionally, in a vehicle equipped with an anti-skid IIJ111 device and a propulsion control device, in addition to the hydraulic control valve, hydraulic pump, accumulator, sensor, etc. used in the anti-skid control device, a separate propulsion control ill device is required. This requires a dedicated hydraulic control valve, hydraulic pump, accumulator, sensor, etc., which results in a complex structure, heavy weight, large installation space, and high production costs.

However, according to the embodiment of the present invention, the conventional anti-skid control device is slightly modified, and the hydraulic control valve,
By completely sharing components such as hydraulic pumps and accumulators, we have constructed a vehicle propulsion control system equipped with an anti-skid control system that has a simple structure, reduces the amount of equipment required, requires less installation space, and reduces production costs. It becomes possible to do so. That is, in the above embodiment, by simply providing a 3-point, 3-position switching valve as a boost pressure control valve between the hydraulic booster and the auxiliary pressure source, and adding an electronic circuit as a propulsion control means to the ECU 74, The above-mentioned difficulties can be solved.

As explained in the flowchart of Fig. 4, anti-skid control and slip control are performed when the displacement sensor
Since the branch is determined depending on whether the brake pedal is OFF, that is, whether the brake pedal is depressed, there is no interference between the two.

As described above, even if a slip occurs in the driving wheel, the 3-bot 3rd position HI77 switching valve 15 is controlled to increase the pressure in the boost air 13e and the wheel cylinder 4 of the driving wheel is controlled.
Since slipping can be suppressed by applying the brake to L14R, it is possible to prevent skidding, poor acceleration, etc. due to slipping. In addition, the wheel cylinder of the driven wheel is 3m
1. Brake pressure is not applied to 3R. The vehicle is not slowed down.

In addition, when using a hydraulic booster with a normal configuration, the high pressure of the accumulator 17 can be changed to the 3-bot 2-position switching valve 10R.
Even if an attempt is made to apply the brake to the wheel cylinder 4L14R through the check valves 9L and 9R, the brake is applied to the reservoir 12 through the master cylinder 2 empty 2c and the boat 2h through the check valves 9L and 9R.
However, in this embodiment, the 3-point/3-position switching valve 15 for boost pressure control is used.
The brake fluid pressure of master cylinder 2 is tlJ.
Since the vehicle is ill, it is possible to apply brake pressure to the wheel cylinder 4L14R.

In the above embodiment, the left and right drive wheels are controlled simultaneously, but the two-point, two-position switching valves 7L and 7R are used.

The left and right drive wheels may be controlled independently by driving the 18L, 18R or 3-bot 2-position switching valve 10R separately. As a result, when the left and right road surface*m coefficients are different, the slip ll1Ij controllability is further improved during cornering and the like. It is also used as a differential lock. Further, in addition to the slip control using the brake, the slip control may also be performed using control of the engine, transmission, clutch, etc.

Further, in this embodiment, the driven wheel speed is used as the vehicle speed, but the vehicle speed is determined using a ground speed meter such as a Doppler speedometer, a vehicle acceleration sensor, a fifth wheel, etc., and a slip judgment is performed. Also good. It is also possible to detect only the drive wheel speed and determine slippage from the amount of change.

Furthermore, control constants such as the slip determination level may be changed during turning based on the signal from the steering sensor.

Although the above is a two-system system in which the front two wheels and two rear wheels are separated, the control can be similarly performed using a two-system system with X piping, which is a combination of the right front wheel and the left rear wheel, or the left front wheel and the right rear wheel.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and it goes without saying that it can be implemented in various forms within II without departing from the gist of the present invention. be.

[Effects of the Invention J As described in detail above, according to the present invention, a conventional vehicle propulsion control device having a hydraulic pressure booster is provided with at least a boost pressure in a flow path that communicates the hydraulic pressure booster with an auxiliary pressure source. In addition to installing a boost pressure 01m valve to control each mode of pressure increase and pressure reduction, boost pressure! 11rllJ valve and hydraulic pressure Il
! The propulsion control means that controls the lI control valve is electronic v! Since it only needs to be installed in the control device, conventional brake fluid pressure control l'
Since it can be constructed by making slight modifications to the i-device, the structure is simple, the length of 4 m can be reduced, the installation space can be reduced, and production costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of the present invention, FIG. 2 is a hydraulic circuit diagram showing an embodiment of the present invention, and FIG. 3 is an explanatory diagram showing the electronic control unit I (ECU) of the embodiment. Fig. 4 is a flowchart showing the operation of the same embodiment. 2... Master cylinders 3L, 3R, 4L, 4R... Wheel cylinders 5L,
5R, 7L17R, 18LJ18R... 2-bottom 2-position switching valve (hydraulic pressure control valve) 10L, 10R... 3-bottom 2-position switching valve (hydraulic pressure control valve) 15... 3-bottom switching valve 3 position switching valve (boost pressure control valve)

Claims (1)

[Scope of Claims] 1. Slip detection means that generates a signal according to the slip state of the wheel; an electronic control device that makes a slip determination based on the signal from the slip detection means and generates a brake fluid pressure control signal; and a master controller. Provided between the cylinder and the wheel cylinder,
A brake fluid pressure control valve that controls the brake fluid pressure of the wheel cylinder by switching it between at least a pressure increase mode and a pressure decrease mode in response to the control signal, a fluid pressure booster that increases force to the master cylinder, and an auxiliary pressure source that supplies brake pressure fluid to a pressure booster; When it is determined that the drive wheels are not slipping and the slip of the driven wheels is equal to or higher than a predetermined value, a boost pressure control signal is output to increase and maintain the boost pressure in the hydraulic booster at a predetermined level, and at the same time Propulsion control means outputs a brake fluid pressure valve control signal to switch the brake fluid pressure in the wheel cylinder to a holding mode, and further increases or decreases the boost pressure in the fluid pressure booster at least in accordance with the boost pressure control signal. 1. A vehicle propulsion control device, characterized in that a boost pressure control valve that switches to each mode is provided between a hydraulic booster and an auxiliary pressure source.