JP3212691B2 - Vehicle brake traction control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake traction control device for a vehicle.

[0002]

2. Description of the Related Art Recently, when a vehicle is started or accelerated on a slippery road surface, or when cornering, the slip ratio of the drive wheels to the road surface is prevented from becoming excessive (idling state), so that startability and acceleration can be improved. Various traction control devices have been proposed that satisfy the requirements of vehicle stability and vehicle stability during cornering.

[0003] The traction control is performed by reducing the applied torque (traction) to the drive wheels. Therefore, the brake control for applying a braking force to the drive wheels or the generated torque (output) of the engine itself is reduced. Engine control (fuel cut, ignition timing retard, etc.) is performed. In both the brake control and the engine control, feedback control is generally performed so that the actual slip value of the drive wheels with respect to the road surface becomes a predetermined target value.

A conventional example in which such traction control is performed by a brake control means is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-14375.
In this publication, there is provided a brake control means for controlling the slip of a drive wheel by brake control, and the hydraulic fluid pressure of a hydraulic booster as a brake booster is used as a brake fluid pressure. In the vehicle slip control device that performs the brake control at the time of the slip control, the brake fluid pressure reducing control valve,
A specific configuration of a brake traction control device provided with an opening means for opening the brake fluid pressure reduction control valve for a predetermined time when the slip control by the brake control is completed is shown.

[0005]

In general, the brake section easily generates frictional heat, and when the above-described brake control system is employed, the brake section is contained in the hydraulic fluid (brake oil) from the hydraulic booster (master cylinder). There is a problem that air bubbles are generated by vapor, and there is a situation that the air bubbles must be removed as needed at the time of maintenance or the like.

Conventionally, in this air bleeding operation, usually, one of the workers increases the hydraulic pressure of the brake oil in the hydraulic booster by depressing a brake pedal, and the other worker increases the hydraulic pressure in the increased pressure state. In this method, air is released by loosening a lock nut of an air bleed screw provided in a brake cylinder on the caliper side.

[0007] Therefore, in this method, at least two workers are absolutely necessary, and there is a problem that the working efficiency is extremely low.

[0008]

Of the appended claims 1 Symbol placement [SUMMARY OF] invention was made to solve the above SL problems purpose, a brake traction vehicle of the present invention of the claim 1, wherein The control device includes: a slip detection unit that detects a slip value of the drive wheel with respect to the road surface; a hydraulic brake unit that applies a braking force to the wheel; ,
The brake traction control device comprising a brake control means for the slip value of the driven wheel to control the hydraulic pressure of the brake means so as to converge to a predetermined target value, stop determines that the vehicle is in a stopped state Judgment means
Is operated by an operator who vents the brake fluid.
Air bleed mode setting switch and operated by the operator
And a pressure-intensifying control switch,
The stage is the air release mode setting switch and the pressure increase control switch.
Switches are turned on, and the stop determination means
When it is determined that the vehicle is in a stopped state by
Regardless of the slip value of the driving wheel,
The pressure is increased to a predetermined level .

[0009]

[Action] brake traction control system of the appended claims 1 Symbol placement of invention, results that are configured on the following, those
In response to above constituting formation performing an operation as follows.

(1) The operation of the invention according to the first aspect : In the vehicle brake traction control apparatus according to the first aspect, a slip detecting means for detecting a slip value of a driving wheel with respect to a road surface, and a braking force applied to the wheel. A hydraulic brake device to be provided, and the brake device so that when the slip value of the drive wheel detected by the slip detection device is equal to or more than a predetermined value, the slip value of the drive wheel converges to a predetermined target value.
A basic brake traction control device is provided with a brake control means for controlling the hydraulic pressure, and traction control by braking force control becomes possible. On the other hand, in the same configuration, stop determination means for determining a stop state of the vehicle
Is operated by an operator who vents the brake fluid.
Air bleed mode setting switch and operated by the operator
And a pressure increase control switch that is
The control means is the air release mode setting switch and
Control switches are turned on, and the above stop judgment is made.
Means that the vehicle is in a stopped state.
The brake hand, regardless of the drive wheel slip value.
It is configured to increase the fluid pressure in the stage to a predetermined level, the operator, the air disconnect performing air bleeding of the brake fluid
By operating the mode setting switch and the pressure increase control switch, the hydraulic pressure of the brake cylinder can be raised without stepping on any brake pedal .

[0011] was Therefore, air venting operation of the brake fluid at the time of vehicle maintenance is to allow well very efficiently by one person.

[0012]

As a result, according to the brake traction control device of the present invention, the work of bleeding the brake fluid is easy, and the vapor lock phenomenon is less likely to occur, which leads to an improvement in reliability.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a control system diagram showing a combination of a system configuration of a vehicle brake traction control device and a configuration of a hydraulic circuit for brake control of wheels according to an embodiment of the present invention.

In FIG. 1, reference numeral A denotes an automobile equipped with a traction control device according to the present embodiment. In this car A, left and right front wheels 1FL and 1FR are driven wheels,
The left and right rear wheels 1RL and 1RR are configured as FR vehicles having driving wheels. That is, the torque generated by the engine 2 mounted on the front of the vehicle body is transmitted to the left rear wheel 1RL via the left drive shaft 6L after passing through the automatic transmission 3, the propeller shaft 4, and the differential gear 5, while the right The power is transmitted to the right rear wheel 1RR via the drive shaft 6R.

The automatic transmission 3 is performed by changing the combination of the excitation and the demagnetization of the plurality of solenoids 13a incorporated in the hydraulic circuit of the torque converter 11 and the multi-speed transmission gear mechanism 12. The torque converter 11 is a hydraulically operated lock-up clutch 11A.
have. By switching between energization and demagnetization of the solenoid 13b incorporated in the hydraulic circuit of the lock-up clutch 11A, engagement and release of the lock-up clutch 11A are performed.

The solenoids 13a and 13b are controlled by a control unit UAT for an automatic transmission. The control unit UAT stores shift characteristics and lock-up characteristics in advance as is known, and performs shift control and lock-up control based on these characteristics. For this control, the control unit UAT includes a main throttle opening signal from a main throttle opening sensor 61 for detecting the opening of the main throttle valve 43 and a sub-throttle for detecting the opening of the sub-throttle valve 45. A sub-throttle opening signal from the throttle opening sensor 62 and a vehicle speed signal (in the embodiment, a rotation speed signal of the propeller shaft 4) from the vehicle speed sensor 63 for detecting the vehicle speed are input.

The wheels 1FR to 1FR of the automobile A
The RR is provided with brakes 21FR to 21RR, respectively. Brake cylinder 7 of each caliper 22FR-22RR of these brakes 21FR-21RR
2, 72... (See FIGS. 2 and 3) each have a hydraulic piping 23
Via FR-23RR, a brake oil pressure according to the depression opening degree of the brake pedal 25 or the set pressure when the pressure increase control switch S2 is turned on, which will be described later, is supplied.

The calipers 22FR to 22RR of the brakes 21FR to 21RR are, for example, shown in FIGS.
(In these figures, for example, the caliper 2 of the right rear wheel 1RR
2RR).
A caliper body 71 having a U-shaped cross section provided through an end of the disc plate 70;
1 from the other end side and slide pin bolt 7
A torque member 78 connected via the first and second brake members 77 and 77, pads 75 and 75 provided between the torque members 78 and opposing each other and holding the disk plate 70 in accordance with the brake oil pressure; Hydraulic piping 23
It is composed of connection ports 73, 74 to which FR to 23RR are connected, and a brake cylinder 72 through which brake oil is introduced or discharged via the connection ports 73, 74. The brake cylinder 72 operates an internal piston (not shown) according to the oil pressure of the brake oil supplied through the hydraulic lines 23FR to 23RR, thereby braking the pads 75, 75 against the disk plate 70. Alternatively, it is operated in the non-braking direction.

On the other hand, an air bleed hole 80 is formed in the cylinder chamber 72a in the brake cylinder 72 so as to be openable to the outside by using the boss portion 79, and the air bleed hole 80 is formed in the air bleed hole 80. Screw 7 for
6 is screwed.

The screw 76 for air bleed has a hexagonal nut portion 76a for turning operation in the middle thereof, and is rotated by using the hexagonal nut portion 76a as necessary, whereby The air in the brake oil can be removed.

The calipers 22FR to 22RR of the brakes 21FR to 21RR are provided with the brake cylinders 72,
The configuration for supplying the brake hydraulic pressure to 72.
It looks like this:

That is, first, the brake pedal 25
Is boosted by a booster 26 using a hydraulic booster and transmitted to a tandem-type master cylinder 27. The hydraulic pressure transmitted to the master cylinder 27 is applied to a brake hydraulic pipe 23 connected to a first oil discharge port 27a of the master cylinder 27.
The signal is transmitted to the left front wheel brake 21FL via the FL and to the right front wheel brake 21FR via the brake hydraulic pipe 23FR connected to the second oil discharge port 27b of the master cylinder 27.

The booster 26 is further supplied with operating oil pressure from an oil pump 29 via a hydraulic line 28, and excess operating fluid is returned to a reservoir tank 31 via a return line 30. A branch pipe 28 from the hydraulic pipe 28
a is branched, and an electromagnetic on-off valve 3 is connected to the branch pipe 28a.
2 are connected. A hydraulic pipe 33 is branched from the booster 26. The hydraulic pipe 33 is connected to an electromagnetic on-off valve 34 and a one-way valve 35 arranged in parallel with the on-off valve 34. ing.

The branch pipe 28a and the hydraulic pipe 33 join at a junction a, and the brake hydraulic pipes 23RL, 23RR for the left and right rear wheels are connected to the junction a. Electromagnetic on-off valves 36A and 37A are connected to the brake hydraulic pipes 23RL and 23RR, respectively. The relief on-off valves 38L and 38R connected to the downstream of the electromagnetic on-off valves 36A and 37A are further connected to the electromagnetic on-off valves 36B and 36B, respectively. , 37B are connected.

Each of the above-mentioned solenoid on-off valves 32, 34, 36A,
37A, 36B and 37B are control units U for traction control each formed by a microcomputer.
It is controlled by TR. That is,
When not performing the slip control by the brake control,
As shown, the electromagnetic on-off valve 32 is closed and the electromagnetic on-off valve 34 is closed.
Is opened, and the electromagnetic on-off valves 36B and 37B are closed, and the electromagnetic on-off valves 36A and 37A are opened. Thus, when the brake pedal 25 is depressed, brake hydraulic pressure is supplied to the front wheel brakes 21FR and 21FL via the master cylinder 27. The operating hydraulic pressure of the hydraulic booster 26 is supplied to the rear wheel brakes 21RR and 21RL via the pipe 33 as brake hydraulic pressure.

On the other hand, on the other hand, the rear wheel 1 as a drive wheel
When the slip value of the RR, 1RL with respect to the road surface is increased and the slip control by the brake control is performed, the electromagnetic on-off valve 34 is closed and the electromagnetic on-off valve 32 is opened.
Then, by the duty ratio control of the electromagnetic on-off valves 36A, 36B, 37A, 37B, the holding of the brake oil pressure, the pressure increase and the pressure decrease are respectively performed. Specifically, assuming that the electromagnetic on-off valve 32 is closed, the brake fluid pressure is maintained when each of the electromagnetic on-off valves 36A, 36B, 37A, 37B is closed, while the electromagnetic on-off valves 36A, 36A, 3
When 7A is open and the electromagnetic on-off valves 36B and 37B are closed, the pressure rises. When the solenoid valves 36A and 37A are closed and the solenoid valves 36B and 37B are open, the pressure is reduced. At this time, the brake oil pressure that has passed through the branch pipe 28a does not act as a reaction force on the brake pedal 25 due to the action of the one-way valve 35.

When the brake pedal 25 is depressed by the driver during the slip control by the brake control, the operating oil pressure of the hydraulic booster 26 corresponding to the depressed amount is used as the brake oil pressure as the one-way valve. 35, rear wheel brakes 21RR, 21RL
Supplied to

On the other hand, the control unit UTR for traction control further reduces the applied torque of the drive wheels 1FL and 1RR to perform slip control by torque control, so that the braking force applied to the drive wheels 1FL and 1RR is controlled. While performing brake traction control by giving
On the other hand, engine output control by variably reducing the generated torque of the engine 2 is also performed. To this end, a main throttle valve 43 connected to an accelerator pedal 42 and a sub-throttle valve 45 connected to a throttle opening adjustment actuator 44 are provided in the intake passage 41 of the engine described above. The sub-throttle valve 45 is controlled by the traction control unit UTR via the actuator 44.

As described above, the control unit UTR for traction control according to the present embodiment performs the brake control and the throttle opening adjustment actuator 4 during the slip control.
4 to control the output of the engine by controlling the engine 4. Therefore, the control unit UTR receives wheel speed detection signals from the wheel speed sensors 64 to 67 for detecting wheel speeds of the front and rear wheels, and also outputs a main throttle opening detection signal from the main throttle opening sensor 61. , A sub-throttle opening detection signal from the sub-throttle opening sensor 62, a vehicle speed detection signal from the vehicle speed sensor 63, an accelerator opening detection signal from the accelerator opening sensor 68, and a steering angle detection signal from the steering angle sensor 69. A normal mode signal set by the mode switch 70, a mode setting signal from an air release mode setting switch S1 manually operated by a maintenance worker during vehicle maintenance, a pressure increasing command signal from a pressure increasing control switch S2, and the like. It is supposed to be.

Further, the control unit UTR includes an input interface unit for receiving various detection signals from the sensors, a microcomputer unit including a CPU, a ROM, and a RAM, an output interface unit, and the above-described electromagnetic valves 32 and 34. , 36A, 37A, 36B, 37B and a drive circuit for driving the actuator 44. The ROM stores control programs and various maps necessary for traction control, and the RAM executes the control. There are various memories required for this.

When the vehicle is stopped, for example, during maintenance of the vehicle, the control unit UTR uses the pressure increasing control circuit for traction control by the braking force control, without actually depressing the brake pedal 25. Brake 2
1FR-21FL caliper 22FR-22RL brake cylinders 72a
The hydraulic pressure can be raised so that even one worker can easily perform the air bleeding operation in the brake oil.

Next, a method of controlling the air release of the brake cylinder in the caliper during the maintenance of the vehicle will be described with reference to the flowchart of FIG.

That is, after the control is started by turning on the unit, first, in step S1, the vehicle is currently stopped (vehicle speed = 0).
Km / h).

As a result, if YES, then step S
In step 2, it is further determined whether or not the parking brake switch is ON, that is, whether or not the vehicle speed is 0 Km / h and the vehicle is stopped and the parking brake is being applied to maintain the vehicle. And the result of the determination is Y
When ES is reached, it is further determined in step S3 whether or not the air release mode setting switch S1 has been turned ON.

If the result is also YES, the process proceeds to step S4, in which the current ignition switch IGSW is turned off.
After confirming that the engine is not in the N state, that is, that it is not in the engine starting state, the flow proceeds to step S5 to operate the oil pump 29 to operate the booster 26 comprising the hydraulic booster shown in FIG. Raise the oil pressure to.

Thereafter, the process further proceeds to step S6, where the brakes 21FL-
The pressure increase control switch S2 for increasing the hydraulic pressure of the brake oil supplied to each of the brake cylinders 72, 72,... Of the 21RR calipers 22FL to 22RR is turned on.
It is determined whether or not the operation has been performed.

As a result, when the result is YES, the solenoid on-off valve 32, which is the pressure increasing valve, is opened, and the cylinder chambers 72a of the brake cylinders 72, 72,.
The hydraulic pressure at 72a is increased to a predetermined level.

In this state, the air bleed screws 76 of the brake cylinders 72, 72,... Of the calipers 22FL to 22RR are automatically set.
・ Release the air from the brake oil by loosening.

Therefore, according to the air bleeding control method, if only the air bleeding mode setting switch S1 and the pressure increase control switch S2 of the traction control unit UTR are turned on and set, another operator is required as in the conventional case. Even if the brake pedal 25 is not depressed, the brake cylinder 72,
.. Can be realized, and the air bleeding operation of the brake cylinder 72 can be easily performed by one person.

In the above control, unlike the above case, the pressure-intensifying switch S2 is turned on in the determination of the step S6.
If NO, the process proceeds to step S8, and the control of the cycle is terminated with the electromagnetic on-off valve 32, which is the pressure increasing valve, kept closed, and the process returns to step S1.

On the other hand, when any one or two or more of the determinations in steps S1 to S3 are determined as NO,
Proceeding to step S9, the ignition switch I
GSW is determined to be ON or OFF, and Y is determined according to the result.
In the case of ES, the oil pump 29 is turned off in step S10.
After setting F, and if NO, the control of the cycle is ended and the process returns to step S1.

[Brief description of the drawings]

FIG. 1 is a control system diagram showing a configuration of a vehicle brake traction control device according to an embodiment of the present invention.

FIG. 2 is a front view showing a configuration of a caliper portion of a brake of the device.

FIG. 3 is a partially cutaway front view showing a configuration of a main part of the caliper part.

FIG. 4 is a flowchart showing a control operation at the time of air release control of the device.

[Explanation of symbols]

 1FL, 1FR Front wheel 1RL, 1RR Rear wheel 2 Engine 3 Automatic transmission 21FL, 21FR Front wheel brake 21RL, 21RR Rear wheel brake 22FL, 22FR Caliper of front wheel brake 22RL, 22RR Caliper of rear wheel brake 72 Brake cylinder 76 Air bleed screw

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-147524 (JP, A) JP-A-64-3537 (JP, A) JP-A-63-231041 (JP, A) JP-A-2- 31963 (JP, A) JP-A-59-184052 (JP, A) JP-A-4-87667 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/00-8 / 96

Claims (1)

(57) [Claims] 1. A slip detecting means for detecting a slip value of a driving wheel with respect to a road surface, a hydraulic brake means for applying a braking force to a wheel, and a slip value of the driving wheel detected by the slip detecting means. A brake control means for controlling the hydraulic pressure of the brake means such that the slip value of the drive wheel converges to a predetermined target value when the vehicle is stopped. A stop determining means for determining that there is a brake fluid;
It has an extraction mode setting switch and a pressure increase control switch operated by the above-mentioned operator.
For example, the brake control means, the air bleeding mode setting Sui
Switch and the pressure increase control switch are
The vehicle is in a stopped state by the above-mentioned stop determination means.
When the judgment is made, regardless of the slip value of the drive wheel,
The pressure of the brake means is increased to a predetermined level.
Brake traction control apparatus for a vehicle, characterized by being made.