JPH09290724A - Brake fluid pressure control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain proper brake fluid pressure control by providing a three-port position switching solenoid valve switching a first/second position in each node of a suction/delivery operation cycle of a fluid pressure pump, so as to eliminate an influence by fluid pressure control relating to a wheel of control object relating to the other wheel of non-control object. SOLUTION: During running of an automobile, for instance, when a side of a wheel FL is decided to be in a lock tendency, a switching valve (3-port 2-position switching solenoid valve) 31 is placed in a no-current carrying condition in a first position. Accordingly, the switching valve 31 communicate with a pressure fluid path Pl, by operation of a fluid pressure pump 21 by a motor 20, a wheel cylinder Wf1 is placed in a pressure reducing mode sucking a brake fluid. When a wheel speed of the wheel FL is recovered, the switching valve 31 is energized, to be placed in a second position, pressure of a brake fluid in the wheel cylinder Wf1 is increased. Thus by switching the switching valve 31 in each node of a suction/delivery operating cycle of an electric motor 20, stable pressure reducing operation is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake hydraulic pressure control device for controlling various braking forces of a vehicle, and more particularly, it is equipped with a hydraulic pump to control the braking force applied to each wheel of the vehicle for each wheel. The present invention relates to a brake fluid pressure control device.

[0002]

2. Description of the Related Art Recent vehicles have a braking force control means and various control functions such as anti-skid control, traction control, vehicle stability control, and the like. Focusing on cost reduction and space saving, while maintaining the basic function of controlling the brake fluid pressure for each wheel, the pressure valve device is made up of inexpensive solenoid valves and the number of solenoid valves is minimized. It is intended to be suppressed.

For example, Japanese Laid-Open Patent Publication No. 6-171487 discloses a device disclosed in Japanese Laid-Open Patent Publication No. 61-235254, in which an X-type piping system is used as a brake master in which a hydraulic control valve including two solenoid valves is used. It is placed in the pipeline from the cylinder to the front left and right wheel brake cylinders, and when any one of these control valves starts control, at least the rear wheel will be affected according to the lower brake fluid pressure of these front wheel brake fluid pressures. It is described that a pressure responsive control valve for controlling the brake fluid pressure of the rear wheel on the same side as the front wheel of the lower brake fluid pressure is provided. Then, using this device as a conventional technique, a brake fluid pressure adjusting device is proposed which can adjust the brake fluid pressures of the front, rear, left and right wheels and requires four or less solenoid valves but does not require the pressure responsive control valve. Has been done.

[0004]

SUMMARY OF THE INVENTION The above-mentioned JP-A-6-171
In the device described in Japanese Patent No. 487, the brake fluid pressures of the front, rear, left, and right wheels can be adjusted with a small number of opening / closing solenoid valves of 4 or less, which is inexpensive. However, by further reducing the number of solenoid valves and providing at least one solenoid valve for each of the two brake fluid pressure systems, the brake fluid pressure can be controlled for each wheel. It is desirable to add a solenoid valve or the like to the base according to the specifications of the vehicle.

Therefore, the present invention provides a brake fluid pressure control device for a vehicle equipped with a fluid pressure pump, which is capable of performing a predetermined fluid pressure control for each wheel by a minimum number of solenoid valves. Is an issue.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present application provides a wheel cylinder which is mounted on each wheel of a vehicle and which applies a braking force, and a brake pedal which operates in response to an operation of the brake pedal. A master cylinder that pressurizes brake fluid by two pressure chambers and outputs master cylinder hydraulic pressure, and first and second communication chambers that communicate one pressure chamber of the master cylinder with a pair of wheel cylinders of the wheel cylinders. First and second ports respectively connected to the hydraulic passages,
A first position having a third port communicating with either one of the first port and the second port, connecting the third port with the first port and blocking the second port; , A 3-port 2-position switching solenoid valve for switching between the second port and a second position for communicating the third port and shutting off the first port, and a third of the 3-port 2-position switching solenoid valve Is provided with a hydraulic pump that connects the port to the suction side and connects the discharge side to the first and second hydraulic passages.

According to a second aspect of the present invention, the three-port two-position switching solenoid valve is configured to switch the first and second positions for each node of the suction and discharge operation cycles of the hydraulic pump. It is desirable to do.

[0008] According to a third aspect of the present invention, the first type is provided.
And each of the first and second hydraulic pressure paths between the connection part of the 3-port / 2-position switching solenoid valve and the connection part on the discharge side of the hydraulic pump for the second hydraulic pressure path. First to wear
And a second orifice.

Further, as described in claim 4, the first
And a second orifice and a connection portion of the 3-port / 2-position switching solenoid valve for each of the first and second hydraulic pressure passages, each of which is interposed in each of the first and second hydraulic pressure passages. , A first and a second check valve for respectively permitting a flow of the brake fluid from the master cylinder to the wheel cylinder and blocking a flow in the reverse direction; and a pair of the first and second check valves and the pair of check valves. Third and fourth hydraulic pressure passages that communicate with the master cylinder between the wheel cylinders and the third and fourth hydraulic pressure passages, respectively, are respectively provided from the wheel cylinder to the master cylinder. It may be provided with third and fourth check valves that allow the flow of the brake fluid and prevent the flow in the reverse direction.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a front wheel drive system (F
F: front engine / front drive) vehicle having an anti-skid control function,
6 to 9 relate to an embodiment having an anti-skid control function in a vehicle of a rear wheel drive system (FR: front engine / rear drive). 10 to 17 relate to an embodiment having a traction control function, a vehicle stability control function and the like in addition to an anti-skid control function in a front-wheel drive vehicle. Therefore, FIGS. 1 to 5 and FIG.
In the embodiments of FIGS. 0 to 17, the left and right brake fluid pressure systems in each drawing are diagonal pipes having the same configuration, and the three-port two-position switching solenoid valve according to the present invention is provided in both brake fluid pressure systems. It has an anti-skid control function as a basic function. The embodiments of FIGS. 6 to 9 are all front and rear pipes, and the three-port two-position switching solenoid valve according to the present invention is arranged in the brake hydraulic system on the front wheel side.

FIG. 1 shows a first embodiment of the present invention, in which wheel cylinders Wfl, Wrr, Wrl and Wfr are mounted on wheels FL, RR, RL and FR, respectively. Are connected to the master cylinder 12. The wheel FR indicates the wheel on the front right side as viewed from the driver's seat, hereinafter the wheel FL indicates the front left side, the wheel RL indicates the rear left side, and the wheel RR indicates the rear right side wheel. Further, the master cylinder 12 is a general tandem master cylinder, and the master cylinder 12 is double-pressure driven via the booster 11 according to the operation of the brake pedal 10, and the reservoir 1
Brake fluid supplied from the first and second pressure chambers 1
The pressure is increased in 2a and 12b to output the master cylinder hydraulic pressure. The booster 11 may be a negative pressure type or a hydraulic type.

As shown in FIG. 1, wheels FL, RR, R
Wheel speed sensors sfl, srr, srl, sfr are provided for L and FR, respectively.
Are arranged and connected to the electronic control unit 100 so that pulse signals of the number of pulses proportional to the rotation speed of each wheel, that is, the wheel speed are input to the electronic control unit 100. The electronic control unit 100 has a microcomputer (not shown) and performs a series of processes such as anti-skid control. In the first to fifth embodiments shown in FIGS. 1 to 5, the two brake fluid pressure systems have the same configuration, and the drawings are bilaterally symmetrical. The parts marked with will be described, and the description of the parts marked with an even number on the right will be omitted. In addition, on the right side, the part to which the reference numeral of each part on the left side is added with 1 corresponds.

First, referring to FIG. 1, the first pressure chamber 12a is formed.
Are wheel cylinders Wfl and W respectively via a main hydraulic pressure passage P0 and first and second hydraulic pressure passages P1 and P2 branched therefrom.
connected to rr. First and second hydraulic pressure passages P1, P2
A first port and a second port of a 3-port 2-position switching solenoid valve 31 (hereinafter, simply referred to as switching valve 31) are connected to and connected to. The intake side of the hydraulic pump 21 is connected to the switching valve 31 via a check valve 23, and the discharge side thereof is connected via the check valve 25, the damper D and the orifice 41 to the main hydraulic passage P0, and by extension the first and the second. It is connected to two hydraulic pressure paths P1 and P2.

The hydraulic pump 21 is driven by one electric motor 20 together with the hydraulic pump 22 of the other brake hydraulic system, introduces the brake fluid from the suction side, raises it to a predetermined pressure, and outputs it from the discharge side. Is configured.
The check valves 23 and 25 regulate the flow of the brake fluid discharged through the hydraulic pump 21 in a fixed direction. Then, the first and second hydraulic pressure passages P1 and P2 between the connection portion of the switching valve 31 and the discharge-side connection portion of the hydraulic pump 21 for the first and second hydraulic pressure passages P1 and P2, respectively. Orifice 4 which is the first and second orifices referred to in the present invention.
3, 45 are interposed. In addition, a well-known proportioning valve 5 is provided for the wheel cylinders Wrr and Wrl on the rear wheel side.
1, 52 are connected.

The structure of the brake hydraulic system on the right side of FIG. 1 is exactly the same as the above, but the hydraulic pump 22 is driven together with the hydraulic pump 21 by the electric motor 20, and after the electric motor 20 is started, both hydraulic fluids are driven. The pressure pumps 21 and 22 are continuously driven, and the pressure of the discharge brake fluid is increased or decreased according to the rotation speed of the electric motor 20. Therefore,
If the load on one hydraulic pump (for example, 22) is small, the driving force on the other hydraulic pump 21 side can be made large, and the pressurizing ability becomes large.

Next, the operation of the first embodiment having the above structure will be described. During normal brake operation, each valve is in the normal position shown in FIG. 1, and the electric motor 20 is stopped. When the brake pedal 10 is depressed in this state, the master cylinder 12 is double-pressure driven via the booster 11, and the master cylinder hydraulic pressures from the first and second pressure chambers 12a and 12b are respectively transferred to two brake hydraulic pressure systems. Is output. Hereinafter, the brake fluid pressure system on the left side of FIG. 1 will be described as a representative of both systems.

During the anti-skid control of the wheel FL or the wheel RR, for example, when it is determined that the wheel FL side is in the lock tendency, the solenoid coil of the switching valve 31 is set to the first position without being excited. Therefore, the switching valve 31 is disconnected from the fluid pressure passage P2 and communicates with the fluid pressure passage P1. At the same time, the electric motor 20 is started and the hydraulic pump 21
Starts operating. Thus, the wheel cylinder Wfl enters the pressure reducing mode, and the brake fluid in the wheel cylinder Wfl is sucked and reduced by the hydraulic pump 21. Then, when the wheel speed of the wheel FL is recovered, the switching valve 31 is excited and switched to the second position to enter the pressure increasing mode, and the master cylinder hydraulic pressure increases the brake fluid in the wheel cylinder Wfl. In this way, the switching valve 31 is intermittently controlled, and the pressure increasing / decreasing control is performed. At this time, the switching valve 31 is switched for each node of the cycle of the suction and discharge operations of the electric motor 20 (every cycle in the present embodiment), and a stable pressure reducing operation is performed.
Details of the operation of the electric motor 20 will be described later.
In addition, orifices 43 and 45 are provided to reduce the influence on the other wheel cylinder during the hydraulic control of one of the wheel cylinders Wfl and Wrr.

The electric motor 20 can be driven with a constant current by duty control, the discharge amount from the hydraulic pump 21 can be appropriately controlled, and the pressure increasing gradient of the wheel cylinder hydraulic pressure in the wheel cylinder Wfl can be adjusted. When the drive device of the electric motor 20 does not have a constant current drive function, the switching valve 3
The pressure increase gradient can be adjusted by intermittently controlling 1 to repeatedly increase and decrease the wheel cylinder hydraulic pressure in the wheel cylinder Wfl and increase in a pulse manner. Therefore, it is called the slow pressure increasing mode or the pulse pressure increasing mode,
Alternatively, since the pressure is increased by the hydraulic pump 21, it is also called a pump pressure increasing mode. Further, even in the depressurization mode, the depressurization gradient can be similarly adjusted.

Then, the brake pedal 10 is released,
When the master cylinder hydraulic pressure becomes smaller than the hydraulic pressure of the wheel cylinder Wfl, the brake fluid in the wheel cylinder Wfl returns to the master cylinder 12 and thus the reservoir 13 via the orifice 43.

Thus, according to this embodiment, while the wheel cylinder Wfl is under hydraulic control, the communication with the hydraulic pump 21 is blocked on the second hydraulic pressure passage P2 side, and the orifice 43 is used. Since the transmission of the pressure fluctuation of the discharge brake hydraulic pressure of the hydraulic pump 21 to the wheel cylinder Wfl side is regulated, the influence of the control of the braking force on the wheels FL on the wheels RR is suppressed as much as possible, and each wheel is independent. Braking force control can be performed. As described above, in the brake fluid pressure system on the left side of FIG. 1, the brake fluid pressures of the wheel cylinders Wfl and Wrr are independently controlled by the intermittent control of the switching valve 31 in accordance with the fluid pressure control mode, and the brake fluid on the right side is controlled. In the hydraulic system as well, the independent control of each wheel is similarly performed, so that appropriate braking force control can be performed.

FIG. 2 relates to a second embodiment of the present invention, and is a brake fluid pressure control device for a diagonal pipe in which both two brake fluid pressure systems are constructed in the same manner as in FIG. In this embodiment, in addition to the first embodiment, the main hydraulic pressure passage P is further added.
A normally open 2-port 2-position open / close solenoid valve 33 (hereinafter, simply referred to as open / close valve 33) is installed at 0. The wheel cylinders Wfl and Wrr are connected to the first pressure chamber 12a of the master cylinder 12 via the returning third and fourth hydraulic pressure passages P3 and P4, respectively. The 3rd and 4th check valves 61 and 67 are interposed. These third and fourth check valves 61, 67 allow the flow of the brake fluid in the direction of the master cylinder 12 and limit the flow in the reverse direction, and when the brake pedal 10 is released, the third and fourth check valves 61, 67 allow the brake fluid to flow. , The wheel cylinder hydraulic pressure in the wheel cylinders Wfl, Wrr can quickly follow the hydraulic pressure decrease on the master cylinder 12 side. Since the other configurations are the same as those of the first embodiment, the description thereof will be omitted.

Regarding the second embodiment having the above configuration,
The operation of the brake fluid pressure system on the left side of FIG. 2 will be described. During normal brake operation, each solenoid valve operates as shown in FIG.
In the normal position shown in, the electric motor 20 is stopped. When the brake pedal 10 is depressed in this state,
First and second pressure chambers 12a, 1 of the master cylinder 12
2b, the master cylinder hydraulic pressure is transferred to the wheel cylinder Wfl through the on-off valve 33, the first and second orifices 43 and 45, and the first and second check valves 63 and 65.
To Wrr.

Next, the anti-skid control in the second embodiment will be described with reference to FIGS. 19 to 21. FIG.
Reference numeral 9 shows a control example in the case where the pressure reduction mode is changed to the holding mode for the wheel cylinder Wfl and the holding mode is changed to the pressure reduction mode for the wheel cylinder Wrr. For example, at time t1, the solenoid of the on-off valve 33 is excited (represented by ON in FIG. 19) to the closed position, and the electric motor 20 is activated (represented by ON in FIG. 19). At this time, the solenoid of the switching valve 31 is not excited (represented by OFF in FIG. 19) and is in the first position shown in FIG. Therefore, the brake fluid in the wheel cylinder Wfl is sucked by the hydraulic pump 21, and the wheel cylinder hydraulic pressure P
fl is decompressed. On the other hand, since the hydraulic pressure passage P2 communicating with the wheel cylinder Wrr is blocked from both the switching valve 31 and the opening / closing valve 33, the wheel cylinder hydraulic pressure Prr is maintained without being reduced.

Then, a pulse is output for each cycle of the suction and discharge operations of the hydraulic pump 21, and in principle the switching valve 31 is responsive to this pulse output (represented by ON in FIG. 19).
Are switched, and the first position (OFF) and the second position (O
N). For example, when the hydraulic pump 21 shifts from the suction stroke to the discharge stroke at time t2, the wheel cylinder hydraulic pressure Pfl is also retained, but one cycle of the hydraulic pump 21 ends and at time t3, the hydraulic pump 21 again performs the suction stroke. When it enters, the switching valve 31 is switched to the second position, the wheel cylinder hydraulic pressure Prr of the wheel cylinder Wrr starts to decrease, and the wheel cylinder hydraulic pressure Pfl of the wheel cylinder Wfl.
Remains in hold mode. At the time of t4, the switching valve 31 is returned to the first position according to the principle, but it can be left at the second position as shown in FIG. At this time, as shown in FIG. 19, the wheel cylinder hydraulic pressure Pfl is set to the holding mode and the wheel cylinder hydraulic pressure Prr is set to the pressure reducing mode.

Next, FIG. 20 shows a control example in the case where the pressure reduction mode is applied to the wheel cylinder Wfl and the (slow) pressure increase mode is applied to the wheel cylinder Wrr. In this case, even after the electric motor 20 is started at t1, the solenoids of the opening / closing valve 33 and the switching valve 31 are not excited, the former remains in the open position, and the latter remains in the first position. Thus, in response to the rotation of the electric motor 20, the wheel cylinder hydraulic pressure Pfl is repeatedly reduced and increased from t1, and as a result, is reduced, and the wheel cylinder hydraulic pressure Prr is repeatedly increased and gradually increased. As a result, the pressure will be increased. Here, the pressure increase gradient of the wheel cylinder hydraulic pressure Prr is t
The reason for the difference between 1-t2 and t2-t3 will be described. First, between t1 and t2, since the hydraulic pump 21 sucks the brake fluid in the wheel cylinder Wfl, most of the brake fluid that has passed through the on-off valve 33 is supplied to the wheel cylinder Wfl side, and as a result, this section is reached. Then, the pressure increase gradient of the wheel cylinder hydraulic pressure Prr becomes relatively small. On the other hand, t2
Between -t3, the hydraulic pump 21 moves the wheel cylinder Wfl.
Since the brake fluid inside is not sucked, the brake fluid that has passed through the on-off valve 33 is distributed substantially evenly to both wheel cylinders Wfl and Wrr, and as a result, the pressure increase gradient of the wheel cylinder fluid pressure Prr is increased in this section. It becomes relatively large.

FIG. 21 shows an example of control when both the wheel cylinders Wfl and Wrr are in the pressure increasing mode. At this time, the electric motor 20 remains activated. The open / close valve 33 remains in the open position, but the switching valve 31 is repeatedly energized and de-energized by the solenoid.
And the second position are switched alternately. Thus, the pressure increase and the pressure decrease are alternately repeated with respect to the wheel cylinder hydraulic pressures Pfl and Prr, and as a result, the pressure is increased.

In any of FIGS. 19 to 21, the gradient of pressure increase / decrease can be set arbitrarily by adjusting the rotation speed of the electric motor 20 by the above-mentioned PWM control, for example. Further, the gradient of pressure increase / decrease can be set arbitrarily by adjusting the duty of excitation / non-excitation of the solenoids of the opening / closing valve 33 and the switching valve 31. Moreover, with the on-off valve 33 (34) blocking communication with the master cylinder 12, the hydraulic pump 21
Since the control by the output hydraulic pressure of (22) is performed, so-called kickback is not caused during the anti-skid control, and no large operating noise is generated unlike the conventional case.

FIG. 3 shows a third embodiment of the present invention, in which orifices 47 and 48 are provided in place of the on-off valves 33 and 34 in the embodiment of FIG. With these orifices 47 and 48, during anti-skid control, the master cylinder 12 and thus the brake pedal 1
The pressure fluctuations transmitted to zero are reduced.

In the fourth embodiment shown in FIG. 4, mechanical pressure response valves 91 to 94 are provided in place of the orifices 43 to 46 of the embodiment shown in FIG. These pressure response valves 91 to 94 have a large flow passage area at the first position in the normal state shown in FIG. 4, and have a large flow passage area at the second position by the built-in orifice, which is the same as the embodiment of FIG. It becomes a mode. Then, the former brake hydraulic pressure is higher in accordance with the pressure difference between the brake hydraulic pressure discharged through the damper D on the discharge side of the hydraulic pumps 21 and 22 and the brake hydraulic pressure on the wheel cylinder Wfl side. In that case, the first position is switched to the second position.

FIG. 5 is a 2-port 2-position open / close solenoid valve (open / close valve) instead of the orifices 43 to 46 of the embodiment of FIG.
35 to 38 and check valves 61, 62, 67 and 68 are provided, and the latter check valves are the check valves 61, 62 and 6 of FIG.
It has substantially the same function as 7,68. The on-off valves 35 to 38 are controlled in substantially the same manner as the on-off valve 33 of the embodiment of FIG. 2 when controlling the hydraulic pressure of each of the wheel cylinders Wfl and the like.

6 to 9 show an embodiment in which the present invention is applied to a vehicle of a rear wheel drive system. In the sixth embodiment shown in FIG. 6, the left front wheel side brake fluid pressure system is as shown in FIG. In contrast to the embodiment, the wheels RR are replaced by the wheels FR, thus eliminating the proportioning valve 51.
In the rear-wheel brake hydraulic system on the right side of FIG. 6, the wheel cylinders Wrr and Wrl of the rear wheels RR and RL are combined into one hydraulic passage P4, and the proportioning valve 52 and the 2-port 2-position opening / closing are provided therein. Solenoid valve (open / close valve) 3
4 is interposed, and the both are connected to the suction side of the hydraulic pump 22 via an orifice 82. Thus, in the present embodiment, the electronic control unit 100 causes the front wheel side of FIG.
The brake fluid pressure system on the left side is controlled in the same manner, and the open / close valve 34 is intermittently controlled on the rear wheel side similarly to the conventional anti-skid control device.

In the seventh embodiment shown in FIG. 7, an orifice 84 is provided in place of the opening / closing valve 34 of the brake fluid pressure system on the rear wheel side in the embodiment of FIG.
Normally closed 2 port 2 position open / close solenoid valve (open / close valve) instead of 2
96 is provided, and the front wheel side is configured similarly to FIG. Thus, the opening / closing valve 96 is intermittently controlled on the rear wheel side similarly to the conventional anti-skid control device.

8 and 9 show a brake fluid pressure system on the front wheel side formed in the same manner as in the embodiment of FIG. 2 (however, the proportioning valve 51 is not necessary), and on the rear wheel side in FIG. The 2-port 2-position open / close solenoid valve 96 is provided in place of the orifice 82 in the above embodiment, and the rear wheel side in FIG. 9 has the same configuration as in the embodiment in FIG. In these embodiments, in addition to the switching valve 31, the on-off valves 33, 3
4, 96 are required, but the desired control characteristics can be easily set by providing an opening / closing valve and / or an orifice for the basic configuration provided with the switching valve 31.

The embodiment shown in FIGS. 10 to 17 is obtained by adding a traction control function and the like to the embodiment shown in FIGS. 1 to 5 in addition to the anti-skid control function. , 12b and the orifices 41, 42 are provided with 2-port 2-position open / close solenoid valves (open / close valves) 71, 72, relief valves 73, 74 and check valves 75, 76, respectively. The on-off valves 71, 72 are normally in the illustrated state, and the brake pedal 10 is in the non-operated state as in the traction control and the hydraulic pump 2
When the brake fluid pressure is supplied to the wheel cylinders Wfl and the like by the wheels 1 and 22, the solenoids of the on-off valves 71 and 72 are excited to be in the closed position.

The relief valves 73, 74 are the hydraulic pump 21,
By returning the brake fluid to the master cylinder 12 when the output brake fluid pressure of 22 exceeds a predetermined pressure,
The downstream side is adjusted to a predetermined pressure. Check valve 75, 7
Reference numeral 6 allows the flow of the brake fluid from the master cylinder 12 to the wheel cylinder Wfl and the like, and blocks the flow in the opposite direction. When the brake pedal 10 is operated during fluid pressure control, the wheel cylinder is passed through these. Brake fluid pressure is applied to. This allows so-called additional steps.

Thus, in FIG. 10, the opening / closing valves 71, 72 and the like are added to the embodiment of FIG. 1, but traction control is possible. That is, when a slip occurs during acceleration of the drive wheels FL and FR, the opening / closing valves 71 and 72
Is set to the closed position, the electric motor 20 is started, and the switching valves 31 and 32 are intermittently controlled. Thereby, the wheel F
Slip during acceleration of L and FR is properly prevented.

11 and 12 are obtained by adding the on-off valves 71, 72 and the like to the embodiment of FIGS. 4 and 5, respectively, to enable traction control, longitudinal braking force distribution control and braking steering control. . Further, in FIG. 13, the front wheel side is configured similarly to the embodiment of FIG. 1, the rear wheel side is configured similar to the embodiment of FIG. 5, and on-off valves 71, 72 and the like are added thereto.

The front-rear braking force distribution control is for controlling the distribution of the braking force applied to the rear wheels to the braking force applied to the front wheels so that the stability of the vehicle is maintained during braking of the vehicle. . In addition, the braking steering control means that when the vehicle turns,
To ensure vehicle stability and track traceability,
The oversteer suppressing control and the understeer suppressing control are performed. Here, the oversteer suppression control is performed by applying a braking force to the front wheel on the outside of the turning and steering the vehicle to the outside of the turning in order to prevent excessive oversteer when the vehicle turns. ,
In order to prevent excessive understeer during turning of the vehicle, braking force is applied to the front outer wheel and the rear two wheels to decelerate while steering the vehicle inward.

14 to 16 are provided with three-port two-position switching solenoid valves (switching valves) 77 and 78 in place of the on-off valves 71 and 72 in the above-described embodiment, and these switching valves 77 and 78 serve as traction. Control, front-rear braking force distribution control, and braking steering control are performed. The embodiment of FIG. 14 is provided with switching valves 77 and 78 instead of the opening / closing valves 71 and 72 of the embodiment of FIG.
Same as 3. The embodiment of FIG. 15 is provided with switching valves 77 and 78 instead of the opening / closing valves 71 and 72 of the embodiment of FIG. 11, and other configurations are the same as those of FIG. The embodiment shown in FIG. 16 corresponds to the on-off valve 7 shown in FIG.
Switching valves 77, 78 are provided instead of 1, 72, and other configurations are the same as in FIG.

The embodiment of FIG. 17 is provided with opening / closing valves 71, 72, check valves 97, 98 and orifices 97a, 98a instead of the switching valves 77, 78 in the embodiment of FIG. By the functions of the check valves 97, 98 and the orifices 97a, 98a and the opening / closing control of the opening / closing valves 91, 92, control similar to the switching control of the switching valves 77, 78 can be performed.

In the embodiment shown in FIG. 18, instead of the switching valves 31 and 32 in the embodiment shown in FIG. 1, two-port two-position open / close solenoid valves (open / close valves) 301 and 302 and pressures on their upstream and downstream sides are provided. Normally closed on-off valves 303, 3 that open and close according to the difference
04 and check valves 305 to 308 are provided, and these allow control similar to that of the switching valves 31 and 32 in FIG. That is, the on-off valves 303 and 304 are provided on the rear wheel side. For example, when the on-off valve 301 (302) is set to the closed position after the hydraulic pump 21 (22) starts operating, a pressure difference occurs between the upstream side and the downstream side. The open / close valve 303 (304) is configured to switch from the closed position to the open position. The check valves 305 to 308 prevent pressure fluctuations on the suction sides of the hydraulic pumps 21 and 22 to smoothly perform the pressure reducing operation.

FIG. 22 shows an example of an apparatus provided with two dampers D for use in the embodiment relating to the front and rear piping system shown in FIGS. 6 to 9 described above. Since the amount of discharge brake required for the hydraulic pumps 21 and 22 is different in the front and rear piping system, it is desirable to use the hydraulic pumps 21 and 22 having different pump capacities. Further, it is desirable that the capacity of the damper D be different accordingly.
For this reason, generally, an additional damper (not shown) is provided for the front wheel side damper D, but not only the number of parts increases but also a communication passage for communicating the front wheel side damper D with the additional damper is provided. Will be needed.

Therefore, in the apparatus shown in FIG. 22, dampers D1 and D2 having different capacities are formed on the front wheel side and the rear wheel side, and the pistons P1 and P2 are biased by springs S1 and S2, respectively, and have the same diameter. Cylinder chambers with different lengths C1,
C2 is configured to communicate with the discharge sides of the hydraulic pumps 21 and 22. In the hydraulic pumps 21 and 22 connected to the electric motor 20, the piston 21p on the front wheel side has a larger diameter than the piston 22p on the rear wheel side. The axial length of the cylinder chamber C1 of the front wheel side damper D1 is longer than the axial length of the rear wheel side cylinder chamber C2, and the cylinder chamber C1 has a larger capacity than the cylinder chamber C2.

[0044]

Since the present invention is configured as described above, it has the following effects. That is, in the brake fluid pressure control device for a vehicle according to the present invention, as described in claim 1,
A 3-port 2-position switching solenoid valve is provided in each of the hydraulic pressure passages and the second hydraulic pressure passage, and the brake hydraulic pressure control can be appropriately performed for each wheel by the minimum solenoid valve, and a predetermined control function is provided. An inexpensive device can be provided. Moreover, it can be applied to both diagonal piping and front and rear piping.

Further, in the brake fluid pressure control device according to the second aspect of the invention, the 3-port / 2-position switching solenoid valve sets the first and second positions for each node of the cycle of the suction and discharge operations of the hydraulic pump. Since it is configured to switch, the brake hydraulic pressure control can be appropriately performed without the hydraulic pressure control for the controlled wheel affecting the other non-controlled wheel.

Further, in the brake fluid pressure control device according to the third aspect, since the first and second orifices are provided on the upstream side of the 3-port / 2-position switching solenoid valve, so-called kickback is reduced. be able to.

According to the brake fluid pressure control device of the fourth aspect, in addition to the above, the first to fourth check valves are provided, so that the fluid pressure control for the wheel to be controlled is performed. It is possible to suppress the influence on the non-controlled wheel at this time and appropriately perform the hydraulic control for each wheel.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a brake fluid pressure control device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a brake fluid pressure control device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a brake fluid pressure control device according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a brake fluid pressure control device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a brake fluid pressure control device according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of a brake fluid pressure control device according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram of a brake fluid pressure control device according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram of a brake fluid pressure control device according to an eighth embodiment of the present invention.

FIG. 9 is a configuration diagram of a brake fluid pressure control device according to a ninth embodiment of the present invention.

FIG. 10 is a configuration diagram of a brake fluid pressure control device according to a tenth embodiment of the present invention.

FIG. 11 is a configuration diagram of a brake fluid pressure control device according to an eleventh embodiment of the present invention.

FIG. 12 is a configuration diagram of a brake fluid pressure control device according to a twelfth embodiment of the present invention.

FIG. 13 is a configuration diagram of a brake fluid pressure control device according to a thirteenth embodiment of the present invention.

FIG. 14 is a configuration diagram of a brake fluid pressure control device according to a fourteenth embodiment of the present invention.

FIG. 15 is a configuration diagram of a brake fluid pressure control device according to a fifteenth embodiment of the present invention.

FIG. 16 is a configuration diagram of a brake fluid pressure control device according to a sixteenth embodiment of the present invention.

FIG. 17 is a configuration diagram of a brake fluid pressure control device according to a seventeenth embodiment of the present invention.

FIG. 18 is a configuration diagram of a brake fluid pressure control device according to an eighteenth embodiment of the present invention.

FIG. 19 is a time chart showing a control situation of anti-skid control in the brake fluid pressure control device according to the second embodiment of the present invention.

FIG. 20 is a time chart showing a control situation of anti-skid control in the brake fluid pressure control device according to the second embodiment of the present invention.

FIG. 21 is a time chart showing a control situation of anti-skid control in the brake fluid pressure control device according to the second embodiment of the present invention.

FIG. 22 is a cross-sectional view showing a part of a device including a damper used in an embodiment of a front and rear piping system according to the present invention.

[Explanation of symbols]

 10 brake pedal, 11 booster 12 master cylinder 13 reservoir 20 electric motor 21,22 hydraulic pump 31, 32, 77, 78 3 port 2 position switching solenoid valve 33-38, 71, 72 2 port 2 position open / close solenoid valve 51, 52 Proportioning valve 73,74 Relief valve 100 Electronic control device sfl, srr, srl, sfr Wheel speed sensor Wfr, Wfl, Wrr, Wrl Wheel cylinder FR, FL, RR, RL Wheel

Claims (4)

[Claims] 1. A wheel cylinder mounted on each wheel of a vehicle for applying a braking force, a master cylinder for boosting brake fluid by two pressure chambers in response to operation of a brake pedal, and outputting a master cylinder fluid pressure, First and second ports respectively connected to first and second hydraulic pressure passages that communicate one pressure chamber of the master cylinder and a pair of wheel cylinders of the wheel cylinders, and the first and second ports. A third port that communicates with any one of the ports, and a first position that communicates the third port with the first port and shuts off the second port; and the second port. And a third port that connects the third port and the second position that shuts off the first port, and a third port of the three-port two-position switching solenoid valve to the intake side. Connect the discharge side to the first and second And a brake fluid pressure control device for a vehicle, comprising a fluid pressure pump connected to the second fluid pressure passage. 2. The three-port two-position switching solenoid valve is configured to switch the first and second positions for each node of a cycle of suction and discharge operations of the hydraulic pump. Item 1. A brake fluid pressure control device for a vehicle according to item 1. 3. The first and second portions between a connection portion of the 3-port / 2-position switching solenoid valve and a discharge-side connection portion of the hydraulic pump for each of the first and second hydraulic pressure passages. The brake fluid pressure control device for a vehicle according to claim 1, further comprising first and second orifices provided in each of the fluid pressure passages. 4. The first and second liquids between the first and second orifices and the connection portions of the 3-port / 2-position switching electromagnetic valve to the first and second hydraulic pressure passages, respectively. First and second check valves, which are provided in each of the pressure passages and allow the flow of the brake fluid from the master cylinder to the wheel cylinders respectively and prevent the flow in the reverse direction, and the first and second check valves.
Of the check valve and the pair of wheel cylinders, the third and fourth hydraulic pressure passages communicating with the master cylinder, and the third and fourth hydraulic pressure passages, respectively. 4. The brake fluid pressure control for a vehicle according to claim 3, further comprising third and fourth check valves which allow the flow of the brake fluid from the wheel cylinder to the master cylinder and prevent the flow in the reverse direction. apparatus.