JP2925662B2 - Vehicle slip control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention appropriately controls a slip generated due to a relationship between a torque applied to drive wheels and a friction coefficient of a road surface not only at the time of braking of a vehicle but also at the time of acceleration. The present invention relates to a vehicle slip control device that is controlled.

[Prior Art] As a conventional example that is technically closest to the present invention, one described in, for example, JP-A-1-111558 is known.

In this system, a brake fluid pressure generated in a master cylinder in response to an operation of a brake pedal is supplied to a wheel cylinder of a brake for suppressing rotation of a drive wheel of a vehicle, and a slip for detecting a slip ratio of the drive wheel. Anti-skid control type brake device provided with an anti-skid control device for preventing a slip ratio of a driving wheel from being excessively provided, comprising: a ratio detecting means; and an electromagnetic hydraulic pressure control device for controlling a hydraulic pressure of a wheel cylinder. In the traction control hydraulic pressure source equipped with a pump and an accumulator, the traction control hydraulic pressure source and the master cylinder are selectively communicated with the electromagnetic hydraulic pressure control device, and the traction control hydraulic pressure source is In the state of communication with the hydraulic pressure control device, the brake fluid discharge port of the electromagnetic hydraulic pressure control device is connected to the reservoir. Was, in the state to communicate the master cylinder to the electromagnetic fluid pressure control device, so that provision of the electromagnetic switching device to block the communication between the reservoir.

[Problem to be Solved by the Invention] However, in such a conventional example, an electromagnetic hydraulic pressure control device which is configured by alternatively providing a torsion control hydraulic pressure source and a master cylinder with a three-position stop valve is used. When the traction control hydraulic pressure source is connected to this electromagnetic hydraulic pressure control device, the brake fluid discharge port of the electromagnetic hydraulic pressure control device is connected to the reservoir, and the master cylinder is connected to the electromagnetic hydraulic pressure control device. When the vehicle is equipped with only an anti-lock control unit, the electromagnetic liquid is not supplied when the vehicle is equipped with only an anti-lock control unit. A passage connecting the brake fluid discharge port of the pressure control device and the reservoir has been newly installed in a block and the like that constitute the antilock control unit. Inevitably, it requires major remodeling. Therefore, there is a problem that the cost increases.

Also, at the time of traction control, it is necessary to control the electromagnetic pressure control device of the achiloc control unit, and there is a problem in terms of durability of the valve.

SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems and to easily add a traction control device to an anti-lock control device for vehicles of different uses, and to enable independent control of both. Another object of the present invention is to provide a slip control device for a vehicle which can improve durability by doing so.

[Means for Solving the Problems] In the present invention, a master cylinder provided with a reservoir, a wheel cylinder disposed on wheels, a storage chamber, and a first cylinder are arranged on the master cylinder side. A first switching control valve that communicates with one of a port and a port on the storage chamber side or switches a connection state to one of three states that shuts off the wheel cylinder with any of them; and a liquid stored in the storage chamber. A control-lock-preventing hydraulic circuit having a pump that returns to a first hydraulic pipe connecting the first switching control valve and the master cylinder; and a master cylinder side interposed by the return position in the first hydraulic pipe. A shutoff valve for switching between communication and shutoff between the master cylinder and the first switching control valve, and the first hydraulic pressure distribution between the shutoff valve and the first switching control valve. A second hydraulic line branched from the pipe, a second pressure source, and connecting the second hydraulic line to one of the second pressure source and the reservoir, or connecting the second hydraulic line When operating the acceleration slip prevention hydraulic circuit having a second switching control valve that switches the connection state to one of three states that shuts off any of these, and the brake lock prevention hydraulic circuit, the shut-off is performed when the brake lock prevention hydraulic circuit is operated. The valve is fixedly controlled to a communicating state, and the second switching control valve is fixedly controlled to a state in which a second hydraulic pressure pipe is shut off from both a second pressure source and a reservoir, and the hydraulic circuit for preventing acceleration slip is provided. When the is operated, a controller that fixedly controls the shut-off valve to a shut-off state and fixedly controls the first switching control valve to a state in which a wheel cylinder is connected to a port on the master cylinder side. And butterflies.

[Operation] According to the present invention, at the time of antilock control (at the time of brake lock prevention control), the shutoff valve is fixedly controlled to be in a communicating state, and the second switching control valve of the acceleration slip prevention hydraulic circuit is set to the second switching control valve. In a state where the two hydraulic lines are fixedly controlled to be in a state of being cut off from both the second pressure source and the reservoir, the brake lock preventing hydraulic circuit is operated to reduce, maintain, and increase the hydraulic pressure of the wheel cylinder. Execute control. In the acceleration slip control, the shutoff valve is fixedly controlled to a shutoff state, and the first switching control valve of the brake lock preventing hydraulic circuit is fixed to a state in which the wheel cylinder is controlled to a port on the master cylinder side. In the controlled state, the hydraulic pressure circuit for preventing acceleration slip is operated, and the pressure of the wheel cylinder is reduced, maintained, and increased using the pressure of the second pressure source.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, reference numeral A denotes a master cylinder which has a reservoir B and is a first pressure source, and generates a hydraulic pressure in response to depression of a brake pedal C. D is a wheel cylinder connected to the master cylinder A by piping, and E is slip detecting means for detecting wheel slip.

F denotes a brake lock preventing hydraulic circuit, which is provided between the master cylinder A and the wheel cylinder D, and controls the hydraulic pressure of the wheel cylinder D when the slip detecting means E detects a braking slip. Switching control valve G
And a pump H for returning the effluent from the wheel cylinder D to the piping on the master cylinder A side.

J is a hydraulic circuit for preventing acceleration slip, which is a shutoff valve K for shutting off connection between the master cylinder A and the first switching control valve G when the slip detection means E detects an acceleration slip, a shutoff valve K, and a brake lock prevention. A second switching control valve M connected between the second switching control valve M and the master cylinder A for controlling the hydraulic pressure of the wheel cylinder D using the pressure of the second pressure source L; And a pipe communicating with the reservoir B.

Next, FIG. 2 shows a schematic formation diagram of an embodiment of the present invention.

In the figure, a master cylinder having 10 hydraulic pressure generating chambers is provided with a reservoir 11 for storing brake fluid, and generates a hydraulic pressure according to the amount of depression of a brake pedal 12.

Reference numeral 20 denotes a wheel cylinder provided on the wheel 21. In this embodiment, only one rear wheel of the drive wheels is representatively shown. Each wheel is provided with a wheel speed sensor 22 for detecting the number of rotations.

The hydraulic pressure generating chamber of the master cylinder 10 is connected to the wheel cylinder 20 via a first passage 31 (corresponding to a first hydraulic pipe in the claims).

Further, a circulation passage 32 branched from the first passage 31 and connected to the storage chamber 41 is provided.

In the vicinity of the branch between the first passage 31 and the circulation passage 32, a first electromagnetic inflow valve 51A as a first switching control valve for controlling the hydraulic pressure of the wheel cylinder 20 of the wheel 21, which is a driving wheel, and a first electromagnetic valve 51A
An electromagnetic outflow valve 52A is provided for each. A check valve 53 that allows only the flow from the wheel cylinder 20 side is provided in parallel with the first electromagnetic inflow valve 51A.

The first electromagnetic inflow valve 51A is a normally open 2-port 2-position electromagnetic valve,
The first electromagnetic outflow valve 52A is a normally closed 2-port 2-position electromagnetic valve, and is controlled by a signal from a controller 60 described later.

In addition, it goes without saying that the electromagnetic inflow valve and the electromagnetic outflow valve may be integrally configured as a three-port three-position electromagnetic valve.

Next, reference numeral 70 denotes a first pump, for example, of a plunger type driven by a motor 71, which is provided in the circulation passage 32,
The suction side of the pump 70 is connected to the storage chamber 41 via a check valve 72.
The discharge side is connected to a first passage 31 connected to the master cylinder 10 via a check valve 73.

The first electromagnetic inflow valve 51A, the first electromagnetic outflow valve 52A,
The storage chamber 41 and the first pump 70 constitute a brake lock preventing hydraulic circuit F.

The motor 71 is also controlled by a signal from the controller 60.

Reference numeral 55 denotes a normally open second shutoff valve provided in the first passage 31 upstream of the above-described brake lock preventing hydraulic circuit F.
This is an electromagnetic shut-off valve that is a port 2 position valve. Solenoid shut-off valve 55
A check valve 56 that allows only the flow from the master cylinder 10 side is provided in parallel.

The reservoir 11 is connected between the electromagnetic shut-off valve 55 and the brake lock preventing hydraulic circuit F by a second passage 33 (corresponding to the second hydraulic pipe in the claims). The second passage 33 has a supply passage 33A and a return passage 33B in the middle thereof in parallel.

A check valve 76 is provided on the discharge side of the second pump 74 which is provided in the supply passage 33A and driven by the motor 75.
, And a pressure accumulator as a second pressure source. The accumulator 80 is connected to the first passage 31 via a second electromagnetic inflow valve 51B which is a normally closed 2-port 2-position valve provided on the way. The discharge side of the second pump 74 is further connected to the return passage 33B via a relief valve 77. Reference numeral 82 denotes a pressure switch, which is turned on when the storage pressure of the storage unit 80 exceeds a predetermined value.

Reference numeral 52B denotes a second electromagnetic outflow valve which is a normally closed 2-port 2-position valve provided in the return passage 33B of the second passage 33.

The second switching control valve M is configured by the second electromagnetic inflow valve 51B and the second electromagnetic outflow valve 52B.

The above-mentioned mainly the electromagnetic shut-off valve 55, the accumulator 80, the second pump 74,
The second electromagnetic inflow valve 51B and the second electromagnetic outflow valve 52B constitute an acceleration slip prevention hydraulic circuit.

The controller 60 is constituted by a microcomputer or the like, inputs and calculates data detected by the wheel speed sensor 22 and the pressure switch 82 according to a control program, and controls the electromagnetic inflow valves 51A and 51B, the electromagnetic outflow valves 52A and 52B, and the electromagnetic shutoff. A CPU that performs processing for controlling the drive of the valve 55 and the motors 71 and 75, a ROM in which a control program and reference data are stored, and a RAM in which data necessary for the above-described sensors and arithmetic control are temporarily stored. And an input unit including a waveform shaping circuit and a multiplexer for selectively outputting an output signal of each sensor to the CPU, and an output unit including a drive circuit for driving each load according to a control signal from the CPU. It has a bus line. Next, the operation of the present embodiment having the above configuration will be described.

(1) During Normal Brake Operation During normal brake operation in which the antilock control and the slip control during acceleration are not performed, the normally opened first electromagnetic inflow valve 51A is open in the off state and the normally closed first electromagnetic inflow valve 51B. , The first and second electromagnetic outflow valves 52A and 52B are off and closed, respectively. The normally open electromagnetic shutoff valve 55 is also in the open position shown in FIG. 2 in the off state, and the master cylinder 10 and the wheel cylinder 20 of the wheel 21 which is the driving wheel are connected, and the accumulator 80 is disconnected. Being independent.

Therefore, when the brake pedal 12 is depressed, the hydraulic pressure in the hydraulic pressure generating chamber is applied to the wheel cylinder 20 via the first passage 31.

(2) At the time of anti-lock control The anti-lock control is performed independently for each wheel.

At the time of the brake operation with the brake pedal 12 depressed, when it is determined by the controller based on the input from the wheel speed sensor 22 that the antilock control needs to be performed, the controller 60 switches the first electromagnetic inflow valve 51A. Close the first electromagnetic outflow valve 52A and open the wheel cylinder 2
The brake fluid of 0 is discharged into the first storage chamber 41 to reduce the pressure.

When the hydraulic pressure of the wheel cylinder 20 is maintained, the first electromagnetic outflow valve 52A is turned off and closed while the first electromagnetic inflow valve 51A is kept closed in the on state.

When the pressure is increased again, the motor 71 is driven to suck up the brake fluid stored in the first storage chamber 41 by the first pump 70 and pressurize the first fluid via the check valve 73 while increasing the pressure.
Return to passage 31. At this time, the first electromagnetic inflow valve 51A is turned off and in the open state, the hydraulic pressure of the master cylinder 10 is exerted, and the pressure of the wheel cylinder 20 is increased again.

Thus, the above operation is repeated to perform the brake lock prevention control.

(3) Slip Control During Acceleration Next, slip control during acceleration will be described.

When the controller 60 determines that the acceleration slip prevention control is necessary based on the data detected by the wheel speed sensor 22 when the vehicle is accelerating, the normally opened first electromagnetic inflow valve 51A in the brake lock prevention hydraulic circuit F is used. And normally closed first
The electromagnetic outflow valve 52A is both OFF, that is, in the open and closed states, and the normally open electromagnetic shutoff valve 55 is turned ON, that is, in the closed state, to cut off the communication between the master cylinder 10 and the wheel cylinder 20.

Then, the second electromagnetic inflow valve 51B is turned on, that is, opened, and the hydraulic pressure of the wheel cylinder 20 is increased by the pressure of the accumulator 80. At this time, the second electromagnetic outflow valve 52B is off, that is, in the closed state.

In this state, when the slip ratio of the wheel 21 is within a predetermined range, the first electromagnetic inflow valve 51B is turned off, that is, closed, while the second electromagnetic outflow valve 52B is kept closed,
The hydraulic pressure of the wheel cylinder 20 is maintained.

When the slip ratio becomes smaller than the predetermined value, the first electromagnetic inflow valve 51 is operated to reduce the pressure of the wheel cylinder 20.
B turns on the second electromagnetic outflow valve 52B in the closed state, that is, opens the second electromagnetic outflow valve 52B. Then, the brake fluid in the wheel cylinder 20 is returned to the reservoir 11 via the return passage 33B.

The above operation is repeated to perform the acceleration slip prevention control. In this control, when the pressure of the pressure accumulator 80 drops below the set value, this is detected by the pressure switch 82, and the rotation of the motor 75 based on a command from the controller 60 drives the pump 74, so that the pressure accumulator 80 Is kept.

In this embodiment, an example is shown in which the hydraulic pressure of the wheel cylinder is controlled by a combination of an electromagnetic inflow valve and an electromagnetic outflow valve. Needless to say, the same control can be performed by using a plurality.

[Effects of the Invention] As described above, according to the present invention, the first switching control valve for performing pressure control for preventing braking lock and the second switching control valve for performing pressure control for preventing acceleration slip are separately provided. And a return line from the pump of the brake lock prevention hydraulic circuit to the first hydraulic line and a second hydraulic line are separately branched from the first hydraulic line. In addition, a traction control device can be easily added to a vehicle equipped with an anti-lock control device without a large modification, and since both can be controlled independently, a durable vehicle slip is provided. A control device can be obtained.

[Brief description of the drawings]

 FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing an embodiment of the present invention. A, 10: master cylinder, B, 11: reservoir, D, 20: wheel cylinder, E: slip detection means, F: hydraulic circuit for preventing brake lock, G: first switching control valve, J: Hydraulic circuit for preventing acceleration slip, L: Second pressure source, M: Second switching control valve, 22: Wheel speed sensor, 31: First passage (first hydraulic pipe), 32 … Circulation passage, 33… Second passage (second hydraulic pipe), 33A… Supply passage, 33B… Return passage, 41… Storage room, 51A, 51B… Electromagnetic inflow valve, 52A, 52B… … Electromagnetic spill valve, 55… Electromagnetic shutoff valve, 60 …… Controller, 80 …… Compressor.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 8/58

Claims (1)

(57) [Claims] 1. A master cylinder having a reservoir, a first cylinder having a reservoir, a wheel cylinder disposed on wheels, a storage chamber, and a wheel cylinder having a master cylinder port and a storage chamber port. A first switching control valve that switches the connection state to one of three states that communicates with one of them or shuts off the wheel cylinder from any of them; and a first switching control valve that stores the stored liquid in the storage chamber. A brake lock preventing hydraulic circuit having a pump that returns to a first hydraulic pipe connecting the master cylinder; and a brake hydraulic circuit that is interposed on the master cylinder side with respect to the return position in the first hydraulic pipe. A shutoff valve for switching between communication with a switching control valve and shutoff, and a second hydraulic pipe branched from the first hydraulic pipe between the shutoff valve and the first switching control valve And a second pressure source,
The second hydraulic line is connected to one of a second pressure source and the reservoir, or the second hydraulic line is switched to one of three states in which the second hydraulic line is disconnected from any of the second pressure source and the reservoir. When operating the acceleration slip preventing hydraulic circuit having a switching control valve, and the brake lock preventing hydraulic circuit, the shutoff valve is fixedly controlled to be in a communicating state, and the second switching control valve is controlled to the second hydraulic circuit. When the pressure pipe is fixedly controlled to be cut off from both the second pressure source and the reservoir, and when the hydraulic circuit for preventing acceleration slip is operated, the cutoff valve is fixedly controlled to be cut off and the second control is performed. 1. A controller for fixedly controlling a switching control valve to a state in which a wheel cylinder is connected to a port on a master cylinder side.