JPH0867237A - Antiskid device for automobile - Google Patents

Abstract

PURPOSE: To attain simplification of a constitution and reduction of a cost while holding practical braking performance. CONSTITUTION: Hydraulic pipes T1, T2 of two systems are connected to a master cylinder 3. Pressure increasing control valves 11, 19 for controlling a pressure of oil from the master cylinder 3 in a direction of increasing the pressure and pressure reducing control valves 12, 20 for controlling similarly in a direction of reducing the pressure, in accordonce with a condition of rotating a wheel, are provided in right/left two wheel sides. Modulatos 16, 24, controlling a pressure of oil in response to a controlled oil pressure by the pressure increasing/reducing control valves 11, 19, 12, 20 so as to equalize a controlled wheel by the control valve to a brake pressure of the right/left same side wheels, are provided in the rest of the other wheel sides. In the halfway of a hydraulic pipe, feeding a controlled oil pressure by the pressure increasing control valves 11, 19 to the pressure reducing control valves 12, 20 and to the modulators 16, 24, check valves 13, 21, permitting operating oil to pass only to the pressure reducing control valves 12, 20 and only to the modulators 16, 24, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile antiskid device.

[0002]

2. Description of the Related Art Conventionally, as this type of anti-skid device, for example, an X-pipe (diagonal pipe) system or the like has been used to construct a hydraulic circuit with two hydraulic pipes, which are anti-skid controlled by a two-system control system. What to do is proposed. In such a two-system control system, cost advantages are recognized as compared with the three-system control system and the four-system control system, and are embodied in various automobiles.

As an anti-skid device embodying a two-system control system, two direct control valves that are controlled to increase or decrease pressure, and indirectly controlled according to the hydraulic pressure by the direct control valves are used. There is one that includes two indirect control valves and simultaneously controls the braking pressures of the wheels arranged on the same side by the operations of the direct control valve and the indirect control valve (for example, JP-A-4-90950). According to this device, a stable braking force can be obtained even on a curve or a straddling road. Further, in such a device, in the case where one hydraulic pipe fails, a safety device is provided in order to perform braking with the hydraulic pipe that has not failed.

[0004]

However, although the above-mentioned conventional technique can obtain a practical antiskid performance in an antiskid device having two systems,
There is still a problem that the structure is complicated. That is, in the above-described anti-skid device, a fail-safe safety device is indispensable, and as this safety device, a mechanical valve or the like driven by the occurrence of a pressure difference has been used.

The present invention has been made in view of the above problems, and an object thereof is to achieve simplification of structure and cost reduction while maintaining practical braking performance. An object is to provide an anti-skid device for automobiles.

[0006]

In order to achieve the above object, the invention as set forth in claim 1 has two systems of hydraulic piping for communicating a wheel cylinder provided on each wheel with a combination of right and left wheels. An anti-skid device for an automobile, comprising: a master cylinder that supplies pressure oil corresponding to a depression operation of a brake pedal to the hydraulic pipes of the two systems, respectively. A pressure increasing control valve is provided for controlling the hydraulic pressure in the pressure increasing direction according to the rotation state of the wheel and sending the pressure oil to the wheel cylinder of the corresponding wheel, and also in the pressure reducing direction, the hydraulic oil for the pressure reducing amount is controlled. A pressure reducing control valve for sending to the reservoir is provided, and the remaining wheels are responsive to the control oil pressure by the pressure increasing control valve and the pressure reducing control valve, and the wheels on the left and right sides of the control wheels by the control valve are provided. An indirect control valve for controlling the hydraulic pressure so that the braking pressures are equal is provided, and further, in the middle of the hydraulic pipe for sending the control hydraulic pressure by the pressure increasing control valve to the pressure reducing control valve and the indirect control valve, The gist of the invention is to provide a check valve that allows passage of hydraulic oil only to the pressure reducing control valve and the indirect control valve.

According to the second aspect of the present invention, the indirect control valve has offset means for keeping the hydraulic pressure on the indirect hydraulic control wheel side higher than the hydraulic pressure on the direct hydraulic control wheel side during depressurization.

According to the third aspect of the present invention, a pressure increasing control valve and a pressure reducing control valve are provided respectively on two wheels belonging to the same hydraulic pipe, and the two pressure reducing control valves have a common reservoir and a common operation. The oil reflux pump is connected.

[0009]

According to the first aspect of the invention, the two left and right wheels are directly hydraulic control wheels, and the braking pressure thereof is controlled by the pressure increasing control valve and the pressure reducing control valve according to the rotational state of the wheels. Controlled by motion. That is, when the pressure is increased, the hydraulic pressure from the master cylinder is controlled in the pressure increasing direction by the pressure increase control valve, and the pressure oil is sent to the wheel cylinder of the corresponding wheel. Further, during depressurization, the hydraulic pressure from the master cylinder is controlled in the depressurizing direction by the depressurization control valve, and the hydraulic oil for the depressurized amount is sent to the reservoir via the check valve. In this case, the remaining other wheels are indirect hydraulic control wheels, and in the indirect hydraulic control wheels, the indirect control valve operates in response to the control hydraulic pressure by the pressure increasing control valve and the pressure reducing control valve.
Here, the indirect hydraulic control wheel and the corresponding direct hydraulic control wheel belong to hydraulic pipes of different systems. And
On the side of the indirect hydraulic pressure control wheel, the hydraulic pressure is controlled so that the braking pressure of the wheel on the same side as the control wheel by the pressure increase / decrease control valve becomes equal. By doing so, an excellent braking force can be obtained even on a curve or a straddling road.

On the other hand, in the apparatus having the above-mentioned structure, when one of the two hydraulic pipes fails (for example, when an oil leak occurs), the hydraulic pressure of the pipe decreases, and the wheels on the corresponding hydraulic pipe side. Then, the braking force cannot be obtained. In this case, the braking pressures of the two control wheels of different systems are controlled to be substantially equal during the anti-skid control, but in the event of a failure, reliable braking is achieved by the wheels on the hydraulic pipe side that have not failed. That is, if the oil pressure of the direct hydraulic control wheel decreases due to oil leakage, for example, the hydraulic pressure for operating the indirect control valve will try to decrease unintentionally, but the hydraulic oil passes only from the pressure increase control valve to the indirect control valve. The check valve that allows the above-mentioned control prevents a decrease in the hydraulic pressure on the side of the indirect control valve, so that the braking force at the indirect hydraulic control wheel is obtained. As described above, according to this configuration, practical braking performance is realized without providing a complicated safety device unlike the conventional anti-skid device.

According to the second aspect of the invention, the offset means of the indirect control valve changes the oil pressure on the indirect hydraulic pressure control wheel side (for example, the rear wheel side) to the direct hydraulic control wheel side (for example, the front wheel side) during depressurization. ) Can be kept higher than the hydraulic pressure. as a result,
A reduction in braking efficiency on the indirect hydraulic control wheel side is suppressed.

According to the third aspect of the invention, in one of the hydraulic pipes, the hydraulic oil is sent from the two pressure reducing control valves to the common reservoir during depressurization, and the hydraulic oil is pumped by the pump for pumping the hydraulic pipe. The inside is refluxed. in this case,
Since the pressure reducing control valve is not provided with a reservoir or the like individually, simplification of the configuration is realized.

[0013]

【Example】

(First Embodiment) A first embodiment in which the present invention is embodied in an automobile anti-skid device using an X pipe (diagonal pipe) system will be described below with reference to the drawings.

FIG. 1 is a hydraulic circuit diagram showing the outline of an anti-skid device. In the anti-skid device of FIG. 1, a brake pedal 1 for boosting the depression force of the pedal 1 is connected to the brake pedal 1, and a tandem type master cylinder 3 is connected to the brake booster 2. The master cylinder 3 operates according to the depression operation of the brake pedal 1. The master cylinder 3 is provided with a first hydraulic port 4 and a second hydraulic port 5.

In the first hydraulic port 4 of the master cylinder 3, a wheel cylinder 7 for the front right (FR) wheel and a wheel cylinder 8 for the rear left (RL) wheel are passed through an anti-skid circuit 6.
A first hydraulic pipe T1 communicating with and is connected. In addition, the second hydraulic port 5 passes through the anti-skid circuit 6 and the wheel cylinder 9 of the right rear (RR) wheel and the left front (FL).
Second hydraulic pipe T communicating with the wheel cylinder 10 of the wheel
2 is connected. The anti-skid circuit 6 adjusts the hydraulic pressure of the master cylinder 3 according to a signal from an electronic control unit (hereinafter referred to as ECU) 40 described later, and sends the hydraulic pressure to the wheel cylinders 7-10.

That is, in the anti-skid circuit 6,
On the first hydraulic pipe T1 side, a hydraulic circuit having a pressure increasing control valve 11, a pressure reducing control valve 12, a check valve 13, a reservoir 14, and a hydraulic pump 15 for controlling the braking pressure of the front right (FR) wheel, A modulator (indirect control valve) 16 for controlling the braking pressure of the left rear (RL) wheel is provided. A P valve (proportioning valve) 17 for generating a hydraulic pressure difference between the front wheel and the rear wheel is provided on the left rear (RL) wheel side. A hydraulic circuit having a pressure increasing control valve 19, a pressure reducing control valve 20, a check valve 21, a reservoir 22, and a hydraulic pump 23 for controlling the braking pressure of the left front (FL) wheel is provided on the second hydraulic pipe T2 side. And a modulator (indirect control valve) 24 for controlling the braking pressure of the rear right (RR) wheel. A P valve 25 is disposed on the right rear (RR) wheel side. Here, the left and right front (FR, FL) wheels directly control the braking pressure, and the left and right rear (RL, RR) wheels indirectly control the braking pressure in response to the front wheel braking pressure. There is.

The detailed structure of the anti-skid circuit 6 shown in FIG. 1 will be described below with reference to FIG. In the anti-skid device of the present embodiment, the hydraulic pipes are connected in the X-shape as described above, but in terms of the hydraulic control system, the wheels on the left and right sides are controlled simultaneously. Of the two pairs of left and right wheels that are simultaneously controlled, the hydraulic circuits for the front and rear (FR, RR) wheels on the right side are shown.

In the first hydraulic pipe T1 of FIG. 2, in the middle of the hydraulic passage T11 which communicates from the master cylinder 3 to the wheel cylinder 7 of the front right (FR) wheel, a pressure increasing control valve 11 composed of an electromagnetic two-position switching valve 11 is provided. Is provided. The pressure increase control valve 11 has a communication position and a cutoff position, and the ECU
When there is no input signal from 40, it is held at the communication position.

The hydraulic passage T11 (point Q1 in the figure)
In the hydraulic passage T12 branched from the check valve 13
A pressure reducing control valve 12 composed of an electromagnetic two-position switching valve is provided via the check valve 13, and the check valve 13 is a pressure increasing control valve 1.
The passage of hydraulic oil is allowed only from 1 to the pressure reducing control valve 12.
The pressure reducing control valve 12 has a cutoff position and a communication position, and is held at the cutoff position when there is no input signal from the ECU 40. A reservoir 14 is connected to the output side of the pressure reducing control valve 12. A hydraulic pump (operating oil recirculation pump) 15 for drawing up the operating oil stored in the reservoir 14 is connected to the reservoir 14. With the above configuration, the braking pressure of the wheel cylinder 7 for the front right (FR) wheel is controlled.

On the other hand, the modulator 24 arranged in the middle of the second hydraulic pipe T2 responds to the control hydraulic pressure by the pressure increasing control valve 11, the pressure reducing control valve 12 and the like (the hydraulic pressure at the point Q2 in the figure), and the rear right side. The braking pressure of the wheel cylinder 9 of the (RR) wheel is indirectly controlled. Indirect hydraulic control wheel (RR wheel) by the modulator 24 and corresponding direct hydraulic control wheel (FR wheel)
Belong to different hydraulic lines.

More specifically, the modulator 24 is formed with a valve chamber 27 and a piston chamber 28 which communicate with each other, and the valve chamber 27 connected to the master cylinder 3 is provided with a substantially spherical valve body 29. The valve body 29 is urged by a compression coil spring 30 in a direction in which it abuts on the valve seat 31 (leftward in the drawing).
A piston 32 that slides in the chamber 28 is disposed in the piston chamber 28. A first pressure chamber 33 is formed on the right side of the piston 32, and a second pressure chamber 34 is formed on the left side. ing. The piston 32 is a compression coil spring 3
2, the rod portion 32a at the right end of the piston 32 abuts the valve element 29 and pushes the valve element 29 away from the valve seat 31. First
A wheel cylinder 9 for the right rear (RR) wheel is connected to the pressure chamber 33 via a P valve 25. Second pressure chamber 3
4 has a check valve 13 in the opposite direction when viewed from the same room 34.
The pressure increase control valve 11 is connected via the, and the pressure reduction control valve 12 is connected.

In the modulator 24 having the above structure, when the hydraulic pressure for increasing the pressure of the normal brake is introduced into the second pressure chamber 34, the valve element 29 and the valve seat 31 are separated from each other, and the second hydraulic pressure of the master cylinder 3 is increased. The hydraulic pressure from port 5 is right rear (R
R) acts on the wheel cylinder 9 of the wheel (state shown). On the other hand, when the hydraulic pressure during depressurization is introduced into the second pressure chamber 34, the piston 32 moves leftward due to the depressurization of the second pressure chamber 34. In this case, the hydraulic pressure acting on the wheel cylinder 9 is held by the contact between the valve body 29 and the valve seat 31, the piston 32 moves further leftward, and the tip end of the rod portion 32a of the piston 32 and the valve body 29 separate. Then, the first pressure chamber 33 becomes large and is decompressed, and the oil pressure of the wheel cylinder 9 drops to a state substantially equal to the oil pressure at the point Q2.

Although not described in detail, the left front part (FL,
The RL) wheel has a similar structure. That is, as shown in FIG. 1, the pressure increasing control valve 19 and the pressure reducing control valve 20 provided in the second hydraulic pipe T2 are electromagnetic two-position switching valves and directly apply the braking pressure of the left front (FL) wheel. Control. The check valve 21 allows passage of hydraulic oil only from the pressure increase control valve 19 to the pressure reduction control valve 20. Further, the modulator 16 provided in the first hydraulic pipe T1 includes the pressure increasing control valve 19,
Left rear (RL) in response to the control oil pressure by the pressure reducing control valve 20.
Indirectly controls wheel braking pressure.

Further, in FIG. 1, each wheel has a wheel speed sensor 36, 37, 38, 3 for detecting each wheel speed.
9 is provided. These wheel speed sensors 36-39
An electromagnetic pickup type sensor or photoelectric conversion type sensor or the like is used as this. The ECU 40 is mainly composed of a microcomputer, and each wheel speed sensor 36-39.
The estimated vehicle speed is calculated based on the input signal from
The locked state of the wheels is determined according to the difference between the estimated vehicle speed and the wheel speed. Then, at the time of lock determination, a control signal is sent to each of the control valves 11, 12, 19, 20 to carry out anti-skid control so as to obtain an optimum braking force. In this case, regardless of whether the lock wheel is the front wheel or the rear wheel, control is performed in a direction to release the lock and obtain stable braking, and the braking pressures of the wheels on the left and right sides are adjusted to be substantially equal.

The operation of the antiskid device constructed as described above will be described below with reference to FIG.
During a normal brake operation, the ECU 40 positions the pressure increase control valve 11 in the communication position and the pressure reduction control valve 12 in the cutoff position. Therefore, when the pressure of the master cylinder 3 increases due to the depression operation of the brake pedal 1, the braking pressure of the wheel cylinder 7 of the front right (FR) wheel increases via the pressure increase control valve 11. Further, the hydraulic pressure from the master cylinder 3 is introduced into the second pressure chamber 34 of the modulator 24 via the check valve 13, so that the second cylinder between the wheel cylinder 9 of the right rear (RR) wheel and the master cylinder 3 is introduced. Hydraulic piping T
2 is communicated, and the pressure of the master cylinder 3 becomes
It acts on the wheel cylinder 9 via.

On the other hand, if any wheel lock is detected from the detection results of the wheel speed sensors 36 to 39 during the brake operation, the ECU 40 executes the following anti-skid control.

That is, during braking, when the difference between the wheel speed and the estimated vehicle body speed at that time reaches a predetermined value (control start speed), the ECU 40 sends a control signal to the pressure increase control valve 11 to control the pressure increase. Operate valve 11 to the shut-off position. As a result, the wheel cylinder 7 of the front right (FR) wheel
The increase of the hydraulic pressure applied to is suppressed and the braking pressure is maintained.
When the wheel speed further decreases and the difference between the wheel speed and the estimated vehicle body speed at that time reaches the lock determination value, the ECU 4
0 sends a control signal to the pressure reducing control valve 12, and the pressure reducing control valve 1
2 is moved to the communication position. As a result, the hydraulic oil is transferred to the reservoir 14 via the check valve 13 and the pressure reducing control valve 12.
And the wheel cylinder 7 for the front right (FR) wheel is depressurized.

At this time, in the modulator 24, the piston 32 moves leftward due to the pressure reduction in the second pressure chamber 34, and the modulator 24 shuts off the second hydraulic pipe T2. As a result, the braking pressure is maintained also in the wheel cylinder 9 for the right rear (RR) wheel. Then, when the pressure is further reduced, the first
The volume of the pressure chamber 33 increases. At this time, since the valve element 29 and the valve seat 31 are in contact with each other, the pressure in the first pressure chamber 33 decreases, and the wheel cylinder 9 of the right rear (RR) wheel is depressurized. In this way, the right front and rear (FR, RR) wheels are brought into a state of being brake-controlled by the same braking pressure.

At the equilibrium position of the piston 32 during depressurization, the hydraulic pressure on the side of the first pressure chamber 33 (on the right rear wheel side) is equal to the spring force of the compression coil spring 35 (for example, 5 kgf / cm ² ) as the offset means. Is kept higher than the hydraulic pressure on the second pressure chamber 34 side (right front wheel side). In other words, when the pressure reducing control is started, the oil pressure upstream of the P valve 25 on the rear wheel side becomes higher than the oil pressure on the front wheel side. Therefore, even in a vehicle in which the front wheels are set to be locked first by the action of the P valve 25, the braking pressure of the rear wheels can be kept higher than the hydraulic pressure of the front wheels during the anti-skid control, and the deterioration of the braking efficiency can be suppressed. be able to.

After that, when the wheel speed is recovered, the ECU 4
With 0, the pressure increase control valve 11 is returned to the communication position and the pressure reduction control valve 12 is returned to the cutoff position to increase the braking pressure. Although the operation of the right front and rear (FR, RR) wheels has been described above, the same applies to the left front and rear (RL, FL) wheels, and the same wheel is brake-controlled at the same braking pressure.

Next, a case where oil leaks from the hydraulic pipe will be described. For example, when oil leakage occurs in the first hydraulic pipe T1 and the hydraulic pressures of the right front (FR) wheel and the left rear (RL) wheel do not rise, the braking force of the brake cannot be obtained for both wheels on the side of the pipe T1. . At this time, the oil pressure at the point Q1 in FIG. 2 decreases, but the oil pressure at the point Q2 does not decrease because the check valve 13 is provided, and the piston position of the modulator 24 is maintained. That is, the master cylinder 3 and the wheel cylinder 9 of the right rear (RR) wheel are maintained in a communicating state, and the braking of the right rear (RR) wheel is ensured. Needless to say, the braking of the front left (FL) wheel functions normally. As a result, on the second hydraulic pipe T2 side, the hydraulic pressure from the master cylinder 3 is supplied to the wheel cylinders 9 and 10 of the right rear (RR) wheel and the left front (FL) wheel connected to the same pipe T2, and The braking force of is obtained.

On the contrary, when oil leakage occurs in the second hydraulic pipe T2 and the braking pressures of the right rear (RR) wheel and the left front (FL) wheel do not rise, they are arranged in the middle of the first hydraulic pipe T1. The modulated modulator 16 is held in a communicating state. As a result, the front right (FR) wheel and the rear left (R) wheel on the first hydraulic pipe T1 side
In the L) wheel, the hydraulic pressure from the master cylinder 3 is supplied to the wheel cylinders 7 and 8 to obtain normal braking force.

As described in detail above, according to the antiskid device of this embodiment, the direct hydraulic control wheel (FR wheel of FIG. 1,
On the FL wheel side, pressure increasing control valves 11 and 19 and pressure reducing control valves 12 and 20 which are controlled according to the rotation state of the wheel are provided, and on the indirect hydraulic control wheel side (RL wheel and RR wheel in FIG. 1) side. Is provided with modulators 16 and 24 that are indirectly controlled in response to the hydraulic pressure on the hydraulic control wheel side. Then, the braking pressures of the wheels are configured to be equal on the left and right sides. Further, in the middle of the hydraulic piping for sending the control hydraulic pressure by the pressure increase control valves 11 and 19 to the pressure reducing control valves 12 and 20 and the modulators 16 and 24,
Check valves 13 and 21 are provided to allow passage of hydraulic oil only in the direction toward the pressure reducing control valves 12 and 20 and the modulators 16 and 24.

As a result, an excellent braking force can be obtained even on a curve or a straddle road, and highly stable braking can be performed. In other words, the front and rear wheels on the same left and right roll on substantially the same road surface, although there is a slight difference between the inner and outer wheels when turning. Even on the crossing road, the wheels on the left and right are the same μ
Roll on the road surface of (friction coefficient). Further, when the vehicle turns, a load is moved due to centrifugal force, but it mainly occurs in the left-right direction, so that the load changes of the front and rear wheels on the same side are similar conditions. Therefore, by simultaneously controlling the wheels on the same left and right sides as in the present embodiment, the braking force can be collectively controlled according to the load movement both at the time of turning and μ of the traveling road surface, and stable control operation can be realized. .

On the other hand, when one of the two hydraulic lines fails (for example, when an oil leak occurs), the hydraulic pressure of the line decreases, and the braking force is obtained at the wheels on the corresponding hydraulic line. Disappear. However, according to this configuration, braking can be realized by the wheels on the hydraulic pipe side that have not failed.

In this way, the structure can be simplified and the cost can be reduced while maintaining practical braking performance without requiring a complicated safety device such as the conventional anti-skid device. .

(Second Embodiment) Next, an automobile anti-skid device according to a second embodiment will be described with a focus on differences from the first embodiment.

FIG. 3 is a diagram showing the structure of the anti-skid device in the second embodiment. As in the first embodiment, each wheel cylinder 7-10 is an X piping type hydraulic pipe T.
1, T2 are connected. That is, the first hydraulic pipe T
1, the wheel cylinder 7 for the front right (FR) wheel and the wheel cylinder 8 for the rear left (RL) wheel are communicated with each other through the anti-skid circuit 6, and the right rear (R) wheel is connected to the second hydraulic pipe T2.
The wheel cylinder 9 for the (R) wheel and the wheel cylinder 10 for the left front (FL) wheel are in communication.

In the first embodiment, one hydraulic control wheel is directly set for each of the two hydraulic pipes T1 and T2, whereas in the second embodiment, the same hydraulic pipe (see FIG. 3) is used. Then, the two wheels belonging to the first hydraulic pipe T1) are both directly hydraulic control wheels. That is, the first hydraulic pipe T of FIG.
1, the braking pressure of the front right (FR) wheel is the pressure increase control valve 1
1, the pressure reducing control valve 12 directly controls the braking pressure of the left rear (RL) wheel by the pressure increasing control valve 19 and the pressure reducing control valve 20. In the second hydraulic pipe T2, the right rear (R
R) wheel and left front (FL) wheel are modulators 24, 16
The braking pressure is indirectly controlled via the.

In the first embodiment, the pressure reducing control valve 12,
20 and reservoirs 14, 22 and hydraulic pump 1 respectively
5 and 23 are provided, in the second embodiment, the pressure reducing control valves 12 and 20 are provided with the common reservoir 14 and hydraulic pump 15.

According to the antiskid device of the second embodiment, the same operation as that of the first embodiment can be obtained, and the structure is simplified and the cost is reduced while maintaining the practical braking performance. Can be achieved.

In addition, in the second embodiment, the hydraulic oil that has passed through the pressure reducing control valves 12 and 20 at the time of pressure reduction is stored in the common reservoir 14 and then pumped up by the operation of the hydraulic pump 15. The hydraulic pipe T1 is recirculated. That is, the hydraulic oil recirculation circuit including the reservoir 14, the hydraulic pump 15, and the like can be configured by one common circuit, and the configuration can be further simplified as compared with the first embodiment.

Further, by using a single hydraulic pump 15, more efficient pump operation can be realized.
That is, in the case of having two circulation circuits, the hydraulic pump on the pressure reducing side operates to recirculate the hydraulic oil, but the other hydraulic pumps tend to idle, in which case the efficiency of pump operation deteriorates. . On the other hand, according to this configuration, since the hydraulic oil at the time of depressurization is stored in the single reservoir 14, it is difficult for the hydraulic pump 15 to run idle, and the full capacity thereof can be used. Further, when the pump runs idle as described above, an unbalanced oscillating force is generated on the motor shaft of the hydraulic pump, which causes noise and vibration, but this configuration can eliminate this.

(Third Embodiment) Next, an automobile anti-skid device of a third embodiment will be described. Figure 3 is the third
It is a figure which shows the structure of the anti-skid apparatus in an Example, and differs from the said 1st Example in this 3rd Example, the left and right front (FR, FL) wheels, and the left and right rear (RR, RL) wheels respectively have the same hydraulic pressure. The hydraulic circuit is configured by a so-called TT piping system, which is connected by piping.

Specifically, the wheel cylinders 7 and 10 of the front left and right (FR, FL) wheels are connected to the first hydraulic pipe T1 via the anti-skid circuit 6, and the left and right rear (RR) to the second hydraulic pipe T2. , RL) Wheel cylinders 9 and 8
Is connected. Here, the left and right front (FR, FL) wheels connected to the first hydraulic pipe T1 directly become hydraulic control wheels,
The left and right rear (RR, RL) wheels connected to the second hydraulic pipe T2 are indirect hydraulic control wheels. Pressure reducing control valves 12, 20
A common reservoir 14 and hydraulic pump 15 are connected to.

In the third embodiment as well, similar to the above-mentioned respective embodiments, it is possible to achieve the object of the present invention to realize the simplification of the structure and the cost reduction while maintaining the practical braking performance. it can. Further, as in the second embodiment, it is possible to simplify further by configuring with one return circuit. (Fourth Embodiment) Next, an automobile anti-skid device of a fourth embodiment using the same TT piping type as that of the third embodiment will be described.

FIG. 5 is a diagram showing the structure of the anti-skid device in the fourth embodiment. In FIG. 5, the left and right front (FR, FL) wheels on the first hydraulic pipe T1 side are direct hydraulic control wheels, and the left and right rear (RR, RL) on the second hydraulic pipe T2 side are indirect hydraulic control wheels. This is similar to the third embodiment. The difference from the third embodiment is that the pressure reducing control valve 12,
Reservoirs 14 and 22 are connected to 20 respectively, and a common hydraulic pump 15 is connected via check valves 41 and 42, respectively.
Connected to. Here, the check valves 41 and 42 only allow passage of the hydraulic oil from the reservoirs 14 and 22 toward the hydraulic pump 15.

Also in the fourth embodiment, the object of the present invention can be achieved in the same manner as the above-mentioned embodiments. Also,
In the case where the circulation circuit is one circuit, if the decompression control valves 12 and 20 have an open failure, a reservoir having a double capacity will be directly connected to the master cylinder, and the bottoming of the master cylinder and the maximum possible braking force will decrease. There is. However, according to the configuration of the fourth embodiment, the above problem can be solved.

The present invention can be embodied in the following modes other than the above embodiment. In the above embodiment, the pressure increase control valves 11 and 19 are electromagnetic two-position switching valves, but they may be mechanical throttle valves.

Further, the following controls can be combined using the anti-skid device constructed as in each of the above embodiments. When the vehicle is turning, when the lateral acceleration (lateral G) calculated / estimated from the speed difference between the left and right wheels before and during control exceeds a predetermined level, control of the inner set of wheels is maintained or controlled from decompression. thing. In this case, over-steering of the vehicle can be suppressed and smooth turning braking can be realized.

In a vehicle having a circuit for detecting yaw and yaw rate, when abnormal yaw increase / decrease occurs during braking, control of left and right pressure increase / decrease so as to moderate the behavior.

Even in a system having a traction function, similar control should be performed during traction control.

[0053]

According to the invention described in claim 1, the excellent effect that the simplification of the structure and the cost reduction can be achieved while maintaining the practical braking performance is exhibited.

According to the second aspect of the present invention, it is possible to suppress a decrease in braking efficiency on the indirect hydraulic pressure control wheel side.
According to the third aspect of the invention, the configuration can be further simplified by sharing the recirculation circuit including the reservoir and the hydraulic oil recirculation pump.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing a configuration of an automobile anti-skid device according to a first embodiment.

FIG. 2 is a hydraulic circuit diagram for the right and left front wheels.

FIG. 3 is a hydraulic circuit diagram showing a configuration of an automobile anti-skid device according to a second embodiment.

FIG. 4 is a hydraulic circuit diagram showing a configuration of an automobile anti-skid device according to a third embodiment.

FIG. 5 is a hydraulic circuit diagram showing a configuration of an automobile anti-skid device according to a fourth embodiment.

[Explanation of symbols]

1 ... Brake pedal, 3 ... Master cylinder, 7-10 ...
Wheel cylinder, 11 ... Pressure increasing control valve, 12 ... Pressure reducing control valve, 13 ... Check valve, 14 ... Reservoir, 15 ... Hydraulic pump as hydraulic oil recirculation pump, 16 ... Modulator as indirect control valve, 19 ... Pressure increasing control Valve, 20 ... Pressure reducing control valve, 21 ... Check valve, 22 ... Reservoir, 23
... hydraulic pump as hydraulic oil return pump, 24 ... modulator as indirect control valve, 35 ... compression coil spring as offset means, T1 ... first hydraulic pipe, T2 ... second
Hydraulic piping.

Claims (3)

[Claims] 1. A hydraulic system of two systems communicating a wheel cylinder provided on each wheel with a combination of left and right wheels, and a pressure oil corresponding to a depression operation of a brake pedal is supplied to the hydraulic system of the two systems, respectively. An anti-skid device for an automobile, comprising a master cylinder, wherein the hydraulic pressure from the master cylinder is controlled in a pressure increasing direction on the left and right two wheel sides in accordance with the rotation state of the wheels. A pressure increasing control valve for sending to the wheel cylinders of the wheels is provided, and a pressure reducing control valve for similarly controlling the pressure decreasing direction to send the hydraulic oil for the pressure reducing to the reservoir is provided. An indirect control valve is provided which responds to the control hydraulic pressure by the pressure control valve and the pressure reducing control valve, and controls the hydraulic pressure so that the braking pressure of the control wheel by the control valve becomes equal to the braking pressure of the wheels on the left and right sides. A check valve that allows passage of hydraulic oil only from the pressure-increasing control valve to the pressure-reducing control valve and the indirect control valve in the middle of the hydraulic pipe for sending the control oil pressure by the pressure-increasing control valve to the pressure reducing control valve and the indirect control valve. An anti-skid device for automobiles, which is provided with. 2. The automobile anti-skid device according to claim 1, wherein the indirect control valve has an offset means for keeping the hydraulic pressure on the indirect hydraulic control wheel side higher than the hydraulic pressure on the direct hydraulic control wheel side during depressurization. The anti-skid device for automobiles. 3. The automobile anti-skid device according to claim 1 or 2, wherein a pressure increasing control valve and a pressure reducing control valve are provided on two wheel sides belonging to the same hydraulic pipe, and the two pressure reducing control valves are provided. Is an anti-skid device for automobiles connected to a common reservoir and a common hydraulic oil recirculation pump.