JPH10315954A - Reservoir tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a required quanity of a fluid in each reservoir chamber while the movement of a fluid in the reservoir space is enabled even if it is inclined by making at least one of partitions for partitioning into plural reservoir chambers in such a manner that the central part is lowest. SOLUTION: Partition walls 26 and 28 divides the interior of a reservoir tank 24 into first, second and third reservoir chambers in order from the left. The partition wall 28 has a slit 200 in the central part thereof. In the slit 200, the height of the base is a required height (h). Even if the reservoir tank 24 is inclined sideways, the relative height of the base of the slit 200 to the fluid level is little changed. Thus, while a rotary flow of a fluid from the second reservoir chamber to the third reservoir chamber is ensured, the decrease in the effective fluid quantity in the third reservoir chamber can be prevented, and the fluid quantity in the first and second reservoir chambers can be prevented from being decreased by fluid leakage in a pump system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reservoir tank, and more particularly to a reservoir tank suitable for use in a hydraulic brake device.

[0002]

2. Description of the Related Art Conventionally, as a reservoir tank used in a hydraulic brake device, for example, a conventional Japanese Utility Model Laid-Open No. 3-55362 is known.
The configuration disclosed in the above publication is known. The above conventional reservoir tank is divided into first and second partitions by a partition having a predetermined height.
Second and third reservoir chambers are provided. The first, second, and third reservoir chambers are provided in this order from the front to the rear of the vehicle. Each of the first and second reservoir chambers communicates with each hydraulic chamber of the tandem master cylinder, and supplies fluid to each hydraulic system of the hydraulic brake device. The third reservoir communicates with the suction side of the pump of the hydro booster to supply fluid to the hydro booster.

[0003] In the above conventional reservoir tank, when fluid leakage occurs in the piping system of the hydro booster, fluid flows out of the third reservoir chamber. In this case, since the third reservoir chamber and the first and second reservoir chambers are partitioned, a certain amount of fluid is secured in the first and second reservoir chambers. Similarly, since the first and second reservoir chambers are partitioned, even if fluid leaks from one of the reservoir chambers due to fluid leakage, a certain amount of fluid is secured in the other reservoir chamber. You. Therefore, according to the above-mentioned conventional reservoir tank, even when fluid flows out of any one of the reservoir chambers due to fluid leakage, fluid can be supplied to at least one hydraulic system of the hydraulic brake device.

[0004] As described above, in the above-mentioned conventional reservoir tank, fluid in the third reservoir chamber is supplied to the hydro booster. On the other hand, the fluid supplied to the hydro booster is desirably recovered to the first or second reservoir chamber via the hydraulic chamber of the master cylinder due to the configuration of the hydraulic circuit of the hydro booster. Therefore, in this case, the first
Alternatively, if the fluid collected in the second reservoir chamber is not returned to the third reservoir chamber, the amount of fluid in the third reservoir chamber decreases with the operation of the hydro booster, and the pump of the hydro booster sucks air. May cause

According to the above conventional reservoir tank, when the fluid level in each reservoir chamber exceeds the height of the partition wall,
Fluid can move between the reservoir chambers over the bulkhead. That is, in the above-described conventional reservoir tank, the fluid in the second reservoir chamber passes over a partition (hereinafter, referred to as a main partition) that separates the second reservoir chamber and the third reservoir chamber from each other. By flowing into
Fluid circulation is realized.

[0006] By the way, the reservoir tank inclines forward of the vehicle when traveling downhill or braking. When the reservoir tank is tilted toward the front of the vehicle, the fluid level of the fluid in the second reservoir chamber is relatively relative to the reservoir tank,
In other words, the liquid is inclined so that the liquid level on the side of the main partition becomes lower. Therefore, even in such a situation, the height of the main partition wall needs to be set sufficiently low in order to allow the fluid to flow from the second reservoir chamber to the third reservoir chamber.

On the other hand, as described above, the main partition has a role of securing the fluid amounts of the first and second reservoir chambers when the fluid volume of the third reservoir chamber decreases due to the failure of the hydro booster system. Have. In this case, the higher the main partition is provided, the more fluid is secured in the first and second reservoir chambers. Therefore, from the viewpoint of securing the amount of fluid in the first and second reservoir chambers when the fluid flows out of the third reservoir chamber, it is desirable to provide the main partition wall high.

As described above, in the above-mentioned conventional reservoir tank, the height of the main partition wall is set so as to achieve the recirculation of fluid from the second reservoir chamber to the third reservoir chamber even when the vehicle leans forward. The setting is made in consideration of securing the amount of fluid in the first and second reservoir chambers when the fluid flows out of the third reservoir chamber.

[0009]

When the vehicle is turning, for example, the vehicle tilts sideways. When the vehicle tilts laterally, the main partition wall tilts in the vehicle lateral direction with respect to the fluid level of the fluid. In this case, the height of the main partition wall decreases on one side relative to the fluid level of the fluid. Under such circumstances, the third
When the fluid flows out of the reservoir chamber, the fluid amount in the second reservoir chamber cannot be sufficiently secured.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and secures a required amount of fluid in each reservoir chamber while allowing the fluid to move between the reservoir chambers even when the reservoir tank is inclined. It is an object of the present invention to provide a reservoir tank capable of performing the following operations.

[0011]

The above object is achieved by the present invention.
As described in the above, in a reservoir tank partitioned by a partition wall and having a plurality of reservoir chambers communicating with each other above the partition wall, at least one of the partition walls is achieved by a reservoir tank configured so that a central portion thereof is lowest. Is done.

In the present invention, the at least one partition is configured so that its central portion is lowest. Therefore, when the fluid level of the reservoir compartment defined by the partition exceeds the height of the central portion of the partition, the fluid can move over the partition. When the reservoir tank is inclined in the in-plane direction of the partition, the height of the partition does not change with respect to the fluid level of the fluid at the center of the partition. Therefore, since the partition wall is configured so that its central portion is the lowest, when the reservoir tank is tilted as described above, the height of the fluid level of the fluid that can move beyond the partition wall is increased. Is prevented from changing.

[0013]

FIG. 1 is a system configuration diagram of a braking force control device to which a reservoir tank according to an embodiment of the present invention is applied. The braking force control device according to the present embodiment is controlled by an electronic control unit (hereinafter, referred to as an ECU) not shown. As shown in FIG. 1, the braking force control device includes a brake pedal 12. The brake pedal 12 is connected to a vacuum booster 14. When the brake pedal 12 is depressed, the vacuum booster 14 generates an assist force Fa having a predetermined boosting ratio with respect to the brake depression force F. A master cylinder 16 is fixed to the vacuum booster 14. Master Linda 16
A first hydraulic chamber 18 and a second hydraulic chamber 20 are provided therein. In the first hydraulic chamber 18 and the second hydraulic chamber 20, a master cylinder pressure PM _{/ C} is generated in accordance with the resultant force of the brake depression force F and the assist force Fa.

A reservoir tank 24 is provided above the master cylinder 16. The interior of the reservoir tank 24 is partitioned by partitions 26 and 28 into a first reservoir chamber 30, a second reservoir chamber 32, and a third reservoir chamber 34 in order from the vehicle front side. First reservoir chamber 30,
The second reservoir chamber 32 and the third reservoir chamber 34 communicate with each other by a space above the partition walls 26 and 28. The first reservoir chamber 32 is the first hydraulic chamber 1 of the master cylinder 16.
It communicates with 8. The second reservoir chamber is in communication with the second hydraulic chamber 20 of the master cylinder 16.

The third reservoir chamber 34 of the reservoir tank 24
A port 35 is provided in the vicinity of the bottom. A front reservoir passage 36 and a rear reservoir passage 38 communicate with the third reservoir chamber 34 via a port 35.
A front reservoir cut solenoid 40 (hereinafter, referred to as SRCF 40) communicates with the front reservoir passage 36. Similarly, a rear reservoir cut solenoid 42 (hereinafter, referred to as SRCR 42) communicates with the rear reservoir passage 38.

A front pump passage 44 communicates with the SRCF 40. Similarly, SRCR42 includes
The rear pump passage 46 communicates. SRCF 40 is
It is a two-position solenoid valve that shuts off the front reservoir passage 36 and the front pump passage 44 when turned off and conducts them when turned on.
The SRCR 42 is a two-position solenoid valve that shuts off the rear reservoir passage 38 and the rear pump passage 46 when turned off and conducts them when turned on.

The first hydraulic chamber 20 and the second hydraulic chamber 22 of the master cylinder 16 have a first hydraulic passage 48,
The second hydraulic passage 50 communicates with the second hydraulic passage 50. A right front master cut solenoid 52 (hereinafter referred to as S
MFR 52) and a front left master cut solenoid 54 (hereinafter, referred to as SMFL 54).
On the other hand, the first hydraulic passage 48 communicates with a rear master cut solenoid 56 (hereinafter, referred to as SMR 56).
A hydraulic pressure sensor 58 for detecting the internal hydraulic pressure, that is, the master cylinder pressure P _{M / C} is provided in the first hydraulic pressure path 48.
Are in communication.

The SMFR 52 communicates with a hydraulic passage 62 provided corresponding to the left front wheel FR. Similarly, SM
A fluid pressure passage 66 provided corresponding to the left front wheel FL communicates with the FL 54. Further, the SMR 56 communicates with hydraulic pressure passages 72 and 74 provided corresponding to the right rear wheel RR and the left rear wheel RL, respectively. SMFR52, SMF
A check valve 7 is provided inside each of L54 and SMR56.
6, 78 and 80 are provided. When the SMFR 52 is turned off, the second hydraulic passage 50 and the hydraulic passage 62
And a two-position solenoid valve that connects the second hydraulic passage 50 and the hydraulic passage 62 via the constant-pressure release valve 76 when they are turned on and on. In addition, SMFL5
4 makes the first hydraulic passage 50 and the hydraulic passage 66 conductive when it is turned off, and connects with the second hydraulic passage 50 via a check valve 78 when it is turned on. Hydraulic passage 6
6 is a two-position solenoid valve that communicates with the solenoid valve 6. Similarly, SM
R56 establishes a conductive state between the first hydraulic passage 48 and the hydraulic passages 72 and 74 when turned off, and a first hydraulic passage via a check valve 80 when turned on. 48
And a two-position solenoid valve that communicates with the hydraulic passages 72 and 74.

A check valve 82 is provided between the second hydraulic passage 50 and the hydraulic passage 62 to permit only fluid flow from the first hydraulic passage 50 toward the hydraulic passage 62. ing. Similarly, between the second hydraulic passage 50 and the hydraulic passage 66,
And a check valve 84 between the first hydraulic passage 48 and the hydraulic passages 72 and 74 that allows only the flow of the fluid from the second hydraulic passage 50 to the hydraulic passage 66; A check valve 86 is provided which allows only the flow of the fluid from the first hydraulic passage 48 toward the hydraulic passages 72 and 74.

The hydraulic passages 62, 66, 72, and 74 respectively have right front wheel holding solenoids 88 (hereinafter referred to as SFRH8).
8), a left front wheel holding solenoid 90 (hereinafter SFL)
H90), a right rear wheel holding solenoid 92 (hereinafter referred to as S
RRH 92) and a left rear wheel holding solenoid 94
(Hereinafter, referred to as SRLH94). SFR
H88, SFLH90, SRRH92, and SRLH9
4, wheel cylinders 96, 98, 10
0 and 102 are in communication.

When the SFRH 88 is turned off, the fluid pressure passage 62 and the wheel cylinder 96 are brought into conduction, and when turned on, the fluid pressure passage 62 and the wheel cylinder 96 are shut off. It is a two-position solenoid valve. Similarly, SFLH90, SRRH92, and S
When the RLH 94 is turned on, the hydraulic pressure passage 66, the wheel cylinder 98, the hydraulic pressure passage 72
And a two-position solenoid valve that shuts off the hydraulic passage 74 and the wheel cylinder 102.

The SFRH 88 is bypassed between the hydraulic passage 62 and the wheel cylinder 96 so that the wheel cylinder 96
A check valve 104 that allows only the flow of fluid from the side to the hydraulic passage 62 side is provided. Similarly, between the hydraulic passage 66 and the wheel cylinder 98, between the hydraulic passage 72 and the wheel cylinder 100, and between the hydraulic passage 74 and the wheel cylinder 102, respectively, the SFLH9
Check valves 106, 108, 110 that allow fluid flow to bypass the 0, SRRH 92, and SRLH 94
Are arranged.

SFRH88, SFLH90, SRRH9
2 and the SRLH 94 respectively include a right front wheel pressure reducing solenoid 112 (hereinafter, referred to as SFRR 112), a left front wheel pressure reducing solenoid 114 (hereinafter, referred to as SFLR 114), and a right rear wheel pressure reducing solenoid 116 (hereinafter, SRRR1).
16) and a left rear wheel pressure reducing solenoid 118 (hereinafter, referred to as SRLR 118).

Note that, hereinafter, SFRH88, SFLH9
0, SRRH92, and SRLH94 are collectively referred to as "holding solenoid S ** H".
104, SFLR106, SRRR108, and SRL
When R110 is collectively referred to as “pressure reducing solenoid S **
R ". A front pressure reduction passage 120 communicates with the solenoids SFRR 112 and SFLR 114 on the front wheel side. Further, the pressure reducing solenoid SRRR116 on the rear wheel side is used.
A rear pressure reducing passage 122 communicates with the SRLR 118. The SFRR 112 is in a two-position where the wheel cylinder 96 and the front pressure reducing passage 120 are cut off by being turned off, and the conductive state is established by turning on the wheel cylinder 96 and the front pressure reducing passage 120. It is a solenoid valve. Similarly, SFLR114, S
When the RRR 116 and the SRLR 118 are turned on, respectively, the wheel cylinder 98 and the front pressure reducing passage 120, the wheel cylinder 100 and the rear pressure reducing passage 122, and the wheel cylinder 102 and the rear pressure reducing passage 1
This is a two-position solenoid valve that makes 22 a conductive state.

A front reservoir 128 and a rear reservoir 130 communicate with the front pressure reducing passage 120 and the rear pressure reducing passage 122 via check valves 124 and 126, respectively, and via check valves 132 and 134, respectively. The suction side of the front pump 136 and the suction side of the rear pump 138 communicate with each other. A front pump passage 44 and a rear pump passage 46 communicate with the suction side of the front pump 136 and the suction side of the rear pump 138.

The discharge side of the front pump 136 is connected via a check valve 140 to a right front pump passage 142 provided corresponding to the right front wheel FR and a left front pump passage 144 provided corresponding to the left front wheel FL. Communicating. On the other hand, the discharge side of the rear pump 138 communicates with the hydraulic passages 72 and 74 via the check valve 146. The right front pump passage 142 is
It communicates with the hydraulic passage 62 via a right front pump solenoid 146 (hereinafter referred to as SPFL 146). The left front pump passage 144 is provided with a left front pump solenoid 148.
(Hereinafter referred to as SPFR 148) through the hydraulic passage 66
Is in communication with The SPFL 146 is a two-position solenoid valve that brings the right front pump passage 142 and the hydraulic passage 62 into conduction when turned off, and shuts off them when turned on. Similarly, SP
The FR 148 is a two-position solenoid valve that brings the left front pump passage 144 and the hydraulic passage 66 into a conductive state when turned off, and shuts them off when turned on.

A check valve 150 is provided between the hydraulic passage 62 and the right front pump passage 142 to allow only fluid flow from the hydraulic passage 62 to the right front pump passage 142. Similarly, a check valve 152 is provided between the hydraulic passage 66 and the front left pump passage 144 to allow only fluid flow from the hydraulic passage 66 to the front left pump passage 144.

Next, the operation of the braking force control device of this embodiment will be described. The braking force control device according to the present embodiment has a normal braking function of generating a braking force in accordance with the master cylinder pressure PM _{/ C} by switching the state of various solenoid valves disposed in the hydraulic circuit, Lock prevention function (AB
S function) and a function of stabilizing the behavior of the vehicle by controlling the braking force (VSC function).

The normal braking function is realized by turning off all the solenoid valves provided in the braking force control device as shown in FIG. Hereinafter, the state shown in FIG. 1 is referred to as a normal brake state. Further, control for realizing the normal brake function in the braking force control device is referred to as normal brake control. In the normal braking state shown in FIG.
The R wheel cylinder 96 is connected to the second hydraulic chamber 20 of the master cylinder 16 through the hydraulic passage 62 and the second hydraulic passage 50.
Is in communication with Similarly, the wheel cylinder 98 of the left front wheel FL communicates with the second hydraulic chamber 20 of the master cylinder 16 via the hydraulic passage 66 and the second hydraulic passage 50. The wheel cylinder 100 of the right rear wheel RR is
It communicates with the first hydraulic chamber 18 of the master cylinder 16 through the second hydraulic pressure passage 48. Similarly, the wheel cylinder 102 of the left rear wheel RL communicates with the first hydraulic chamber 18 of the master cylinder 16 via the hydraulic passage 74 and the first hydraulic passage 48. In this case, the wheel cylinders 96 to 102
Wheel cylinder pressure P _{W / C} is always the master cylinder pressure P
It is controlled to equal pressure with _{M / C.} Therefore, according to the state shown in FIG. 1, the normal brake function is realized.

The ABS function in the state shown in FIG.
This is realized by operating the front pump 136 and the rear pump 138 and appropriately driving the holding solenoid S ** H and the pressure reducing solenoid S ** R in accordance with the slip state of the wheels. Hereinafter, control for realizing the ABS function in the braking force control device is referred to as ABS control.

The ECU determines that the vehicle is in a braking state and
When an excessive slip ratio is detected for any of the wheels, the ABS control is started. The ABS control is started in a situation where the brake pedal 12 is depressed, that is, in a situation where the master cylinder 16 is generating a high master cylinder pressure PM _{/ C.} During the execution of the ABS control, the master cylinder pressure PM _{/ C} is supplied via the first hydraulic pressure passage 48 and the second hydraulic pressure passage 50 to the hydraulic pressure passages 66, 62 provided for the left and right front wheels, respectively. And, it is led to hydraulic pressure passages 74 and 72 provided corresponding to the left and right rear wheels. Therefore, in such a situation, the holding solenoid S ** H is opened,
When the pressure reducing solenoid S ** R is closed, the wheel cylinder pressure P _{W / C} of each wheel can be increased. Hereinafter, this state is referred to as a pressure increase mode.

When both the holding solenoid S ** H and the pressure reducing solenoid S ** R are closed during the execution of the ABS control, the wheel cylinder pressure P _{W / C} of each wheel can be held. . Hereinafter, this state is referred to as a holding mode. Further, during execution of the ABS control, the holding solenoid S *
When * H is closed and the pressure reducing solenoid S ** R is open, the wheel cylinder pressure P _{W / C} of each wheel can be reduced. Hereinafter, this state is referred to as a decompression mode.

During the ABS control, the ECU 10 controls the holding solenoid S ** H according to the slip state of each wheel so that the above-described pressure increasing mode, holding mode, and pressure reducing mode are appropriately realized for each wheel. And the pressure reducing solenoid S ** R. When the holding solenoids S ** H and the pressure reducing solenoids S ** R are controlled as described above, the wheel cylinder pressures P _{W / C of} all the wheels can be appropriately adjusted so as not to generate an excessive slip ratio on the corresponding wheels. Controlled by pressure. As described above, according to the above control, the ABS function can be realized in the braking force control device.

When the decompression mode is performed on each wheel during the execution of the ABS control, the brake fluid in the wheel cylinders 96 to 102 passes through the front decompression passage 120 and the rear decompression passage 122 to the front reservoir 128 and the rear reservoir 130. Flows into. The brake fluid flowing into the front reservoir 128 and the rear reservoir 130 is
The water is pumped by the front pump 136 and the rear pump 138 and supplied to the hydraulic passages 62, 66, 72, 74.

A part of the brake fluid supplied to the hydraulic passages 62, 66, 72, 74 flows into the wheel cylinders 96 to 102 when the pressure increasing mode is performed in each wheel.
The rest of the brake fluid flows into the master cylinder 16 to compensate for the outflow of the brake fluid.
Therefore, according to the system of the present embodiment, an excessive stroke does not occur on the brake pedal 12 during execution of the ABS control.

The VSC function uses the front pump 136 and the rear pump 138 as a hydraulic pressure source when the brake pedal 12 is not operated and the wheel cylinders 96 to
2 is controlled by controlling the hydraulic pressure (hereinafter referred to as wheel cylinder pressure P _{W / C} ). Hereinafter, the control for realizing the VSC function is referred to as VSC control. The ECU determines whether the behavior of the vehicle tends to be unstable based on the traveling speed, acceleration, lateral acceleration, yaw rate, and the like of the vehicle.

FIG. 2 shows a state of the braking force control device formed by the ECU when it is determined that the behavior of the vehicle tends to be unstable. The state shown in FIG. 2 corresponds to the SRCF 40 and the SRCR 4 in the normal brake state shown in FIG.
2, and the holding solenoid S ** H is turned on, and the front pump 136 and the rear pump 138 are operated. The state shown in FIG. 2 is hereinafter referred to as a VSC precharge mode.

In the VSC precharge mode shown in FIG. 2, the suction side of the front pump 136 communicates with the third reservoir chamber 34 of the reservoir tank 24 via the front pump passage 44 and the front reservoir passage 36. The suction side of the rear pump 138 is connected to the rear pump passage 46.
And the reservoir tank 2 via the rear reservoir passage 38.
4 and communicates with the third reservoir chamber 34. Therefore, the brake fluid in the third reservoir chamber 34 is
6 and the rear pump 138 to supply hydraulic pressure passages 62 and 66 and hydraulic pressure passages 72 and 74, respectively.

In the VSC precharge mode, the hydraulic passages 62, 66, 72, 74 and the wheel cylinders 96-1
Since 02 is in the cutoff state, the wheel cylinder pressure P _{W / C} is not increased. In this case, all of the brake fluid supplied to the hydraulic passages 62 and 66 is supplied to the second hydraulic passage 50 and the master cylinder 1.
6 through the second hydraulic chamber 20 and the second
It is collected in the reservoir chamber 32. The hydraulic passages 72, 7
All of the brake fluid supplied to 4 is recovered to the first reservoir chamber 30 of the reservoir tank 24 through the first hydraulic pressure passage 48 and the first hydraulic chamber 18 of the master cylinder 16.

After forming the VSC precharge mode shown in FIG. 2, the ECU starts VSC control when it detects that the tendency of the vehicle to further destabilize further. In the VSC control, the holding solenoid S ** H and the pressure reducing solenoid S ** R in the VSC precharge mode shown in FIG.
Is appropriately driven according to the behavior of the vehicle.

FIG. 3 shows a state in which the holding solenoid S ** H is turned off in the VSC precharge mode. Hereinafter, the state shown in FIG. 3 is referred to as a VSC pressure increase mode. In the VSC pressure increasing mode shown in FIG.
2, 66, 72, 74 and the wheel cylinders 96 to 102 are in a conductive state, respectively. For this reason, the hydraulic passage 6
A part of the brake fluid supplied to 2, 66, 72, 74 is supplied to wheel cylinders 96 to 102, so that wheel cylinder pressure P _{W / C} is increased.

In this case, the remaining part of the brake fluid supplied to the hydraulic passages 62 and 66 passes through the second hydraulic passage 50 and the second hydraulic chamber 20 of the master cylinder 16 and the second reservoir chamber of the reservoir tank 24. Collected at 32. Also,
The remaining part of the brake fluid supplied to the hydraulic passages 72 and 74 is recovered to the first reservoir chamber 30 of the reservoir tank 24 through the first hydraulic passage 50 and the first hydraulic chamber 18 of the master cylinder 16.

In the VSC pressure increase mode, when the holding solenoid S ** H is turned on, the wheel cylinder pressure P
_{W / C} is maintained in a state where the pressure is increased. This state is hereinafter referred to as a VSC holding mode. Also, the holding solenoid S
When both ** H and the pressure reducing solenoid S ** R are turned on, the wheel cylinders 96 to 102 and the front reservoir 128 or the rear reservoir 130 communicate with each other.
The wheel cylinder pressure P _{W / C} is reduced. Hereinafter, this state is referred to as a VSC pressure reduction mode.

During VSC control, the ECU appropriately sets the VSC pressure increasing mode, VSC holding mode,
The holding solenoid S ** H and the pressure reducing solenoid S ** according to the behavior of the vehicle so that the VSC pressure reducing mode is realized.
Control R. When the holding solenoid S ** H and the pressure reducing solenoid S ** R are controlled as described above, the wheel cylinder pressures P _{W / C of} all wheels are controlled to appropriate pressures so as to stabilize the behavior of the vehicle. You. Thus, according to the above control, the VSC function can be realized in the braking force control device. In the following description, the VSC control includes that the braking force control device is set to the VSC precharge mode.

In the above description, the hydraulic pressure control device executes the VSC control. However, the hydraulic pressure control device according to the present embodiment controls the braking force against the wheel slip caused by excessive driving torque. By doing so, traction control control (TRC control) that prevents the traction control can be executed. As described above, in the braking force control device of the present embodiment, the reservoir tank 24 is partitioned into the first reservoir chamber 30, the second reservoir chamber 32, and the third reservoir chamber. Then, from the first reservoir chamber 30 to the first hydraulic chamber 18 of the master cylinder 16, from the second reservoir chamber 32 to the second hydraulic chamber 20 of the master cylinder 16, from the third reservoir chamber 34 to the front pump 136 and the front pump 138. , Each supplied with fluid.

Therefore, for example, when fluid flows out of the first reservoir chamber 30 corresponding to the rear wheel side due to the occurrence of fluid leakage in the rear wheel side system, the amount of fluid in the second reservoir chamber 32 decreases. Is prevented. Therefore, even if fluid leakage occurs in the system on the rear wheel side, the normal braking function can be realized on the front wheel side. Similarly, even if fluid leakage occurs in the system on the front wheel side, the normal braking function can be realized on the rear wheel side.

The same applies to a case where fluid leaks from the third reservoir chamber 34 due to fluid leakage in a system (hereinafter referred to as a pump system) from the third reservoir chamber 34 to the front pump 136 or the rear pump 138. In addition, the amount of fluid in the first reservoir chamber 30 and the second reservoir chamber 32 is ensured. Therefore, also in such a case, the normal braking function can be realized in both the front wheel side and the rear wheel side systems.

As described above, since the reservoir tank 24 is divided into three reservoir chambers, even if fluid leakage occurs in any of the systems, the braking force control device according to the present embodiment can control the front wheels and the rear wheels. Fail-safe measures have been taken to enable normal braking function for at least one of the wheels. As mentioned above, VSC
During the execution of the control, the rear pump 138 and the front pump 136 are supplied from the third reservoir chamber 34 of the reservoir 24.
The fluid that has been pumped up is collected in the first reservoir chamber 30 and the second reservoir chamber 32, respectively. Therefore, if the fluid is not recirculated from the second reservoir chamber 32 to the third reservoir chamber 34, the amount of fluid in the third reservoir chamber 34 will decrease with the execution of the VSC control. When the fluid level in the third reservoir chamber 34 falls below the height of the opening of the port 35, fluid is not supplied to the front pump 136 and the rear pump 138, and the front pump 136 and the rear pump 138 are not supplied.
Causes air suction (hereinafter, referred to as air suction).

In this case, since the VSC control is not executed continuously for a certain period of time or more, if a sufficiently large amount of fluid is stored in the third reservoir chamber 34, the fluid is stored in the third reservoir chamber 34. VSC even if is not refluxed
It is possible to prevent the occurrence of air suction accompanying the execution of the control. However, storing a large amount of fluid in the third reservoir chamber 34 is not preferable because the reservoir tank 24 becomes large.

In this embodiment, the second reservoir chamber 32 and the third reservoir chamber 34 of the reservoir tank 24
Communicate with each other via the space above the. Therefore, the fluid in the second reservoir chamber 32 exceeds the partition wall 28 and
If the fluid can flow into the reservoir chamber 34, the recirculation of fluid from the second reservoir chamber 32 to the third reservoir chamber 34 is realized, thereby preventing the occurrence of air suction without increasing the size of the reservoir tank 24. be able to.

In order to allow such fluid recirculation, the height of the partition wall 28 must be lower than the fluid level in the reservoir tank 24. Further, the relative level of the fluid in the reservoir tank 24 with respect to the partition wall 28 depends on the inclination state of the reservoir tank 24, that is,
It changes depending on the vehicle's inclination. Therefore, in setting the height of the partition wall 28 so that the fluid can be recirculated, the amount of fluid in the reservoir tank 24 and the level change of the fluid due to the inclination of the vehicle must be considered.

FIGS. 4 and 5 show the reservoir tank 24 viewed from the side of the vehicle when the vehicle is in a horizontal state and when the vehicle is in a forward leaning state, respectively. The reservoir tank 24 is attached to the vehicle such that the left side in FIG. 4 is forward of the vehicle. As shown in FIGS. 4 and 5, in the reservoir tank 24, a fluid level (hereinafter, referred to as a lower limit level) corresponding to an allowable lower limit of the fluid is displayed as a “min” level. The second reservoir chamber 24 is provided with a float sensor (not shown) for detecting a fluid level. In addition,
FIG. 4 and FIG. 5 show a state in which the reservoir tank 24 contains fluid of an allowable lower limit.

As shown in FIG. 4, when the vehicle is in a horizontal state, the level of the fluid in the reservoir tank 24 matches the lower limit level. Therefore, if the height of the partition wall 28 is lower than the lower limit level, the fluid in the second reservoir chamber 32 can return to the third reservoir chamber 34 over the partition wall 28. On the other hand, as shown in FIG. 5, when the vehicle is in the forward leaning state, the fluid level on the second reservoir chamber 32 side of the partition wall 28 is lower than when the vehicle is in the horizontal state. For this reason, when the forward inclination angle of the vehicle becomes larger than a certain level, the fluid in the second reservoir chamber 32 becomes the third fluid.
It will not be possible to return to the reservoir chamber 34.

During execution of the VSC control, the vehicle leans forward due to traveling downhill and deceleration by engine braking. Therefore, in order to always allow the recirculation of fluid from the second reservoir chamber 32 to the third reservoir chamber 34,
A situation in which the maximum inclination angle of a downhill road where VSC control is assumed to be continuously performed and the maximum deceleration due to engine braking are superimposed (for example, an engine without performing a brake operation on a long winding steep road). The forward lean angle (hereinafter referred to as the maximum forward lean angle α) of the vehicle in a situation where the vehicle descends only by the brake) is determined, and even if the vehicle leans forward by the maximum forward lean angle α, the second reservoir chamber 3 of the partition wall 28 is obtained.
The height of the partition walls 28 must be set sufficiently low so that the fluid level on the two sides does not fall below the height of the partition walls 28.

On the other hand, as described above, the partition wall 28 serves to secure the amount of fluid in the first reservoir chamber 30 and the second reservoir chamber 32 when the fluid flows out of the third reservoir chamber 34 due to fluid leakage of the pump system. have.
In this case, the first reservoir chamber 30 and the second reservoir chamber 32
The larger the partition wall 28 is provided, the larger the amount of fluid secured is. Therefore, in the event that fluid leakage occurs in the pump system, in order to secure a required amount of fluid in the first reservoir chamber 30 and the second reservoir chamber 32, the partition wall 28 is required.
Must be set to a certain height.

Further, if a large deceleration occurs in the vehicle due to the engine brake during the execution of the VSC control, the reservoir tank 24 tilts forward and the fluid in the reservoir tank 24 is temporarily moved forward by the inertia force due to the deceleration. Move to. FIG. 6 shows a state in which the reservoir tank 24 tilts forward and the fluid moves forward of the vehicle due to a large deceleration of the vehicle. As shown in FIG. 6, when the fluid moves forward of the vehicle, the fluid level on the second reservoir chamber 32 side of the partition wall 28 is reduced to almost zero. Under such circumstances, no matter how low the height of the partition wall 28 is set, fluid cannot flow from the second reservoir chamber 32 to the third reservoir chamber 34.

In this case, if the height of the partition wall 28 is set low, the amount of fluid stored in the third reservoir chamber 34 in the state shown in FIG. 6 becomes small. When the VSC control is executed in such a state, before the fluid returns to the normal state (ie, the state shown in FIG. 5), the fluid level of the third reservoir chamber 34 falls below the height of the communication port of the port 35, Air suction may occur. As described above, it is necessary to set the height of the partition wall 28 to a certain value or more from the viewpoint of preventing the occurrence of air suction when a large deceleration occurs in the vehicle.

Therefore, the height of the partition wall 28 can be adjusted i) even when the vehicle is tilted forward, from the second reservoir chamber 32 to the third reservoir chamber 3.
4 to allow the fluid to recirculate to the second reservoir chamber 30 in the event of a fluid leak in the pump system.
And ensuring the amount of fluid in the second reservoir chamber 32,
And iii) ensuring the amount of fluid in the third reservoir chamber 34 when a large deceleration acts on the vehicle. The height of the partition wall 28 set to satisfy these conditions is hereinafter referred to as a required height h.
Called.

By the way, when the vehicle is turning, a lateral acceleration is applied to the vehicle, so that the vehicle is tilted laterally. In this case, the reservoir tank 24 is also inclined in the vehicle lateral direction together with the vehicle. FIG. 7 shows a state in which the reservoir tank 24 is inclined in the lateral direction of the vehicle when the partition wall 28 is configured to have the required height h over the entire width (the partition wall having such a configuration is denoted by reference numeral 28 ′). Is shown when viewed from behind the vehicle.

As shown in FIG. 7, when the reservoir tank 24 is inclined in the lateral direction of the vehicle, the height of the partition wall 28 'decreases on one side (the right side in FIG. 7) with respect to the fluid level of the fluid. In this state, if fluid flows out of the third reservoir chamber 34 due to fluid leakage of the pump system, the amount of fluid secured in the second reservoir chamber 32 decreases. In this regard, the configuration of the partition 28 'shown in FIG.
This is not desirable for fail-safe measures.

In the state shown in FIG.
The amount of fluid in the region above the communication port 5 (the region indicated by the hatched line in FIG. 7), that is, the amount of fluid that can be supplied from the third reservoir chamber 34 without causing air suction ( Hereinafter, the effective fluid amount is reduced as compared with a case where the vehicle does not tilt laterally. For this reason, when the fluid moves forward due to a large deceleration acting on the vehicle as shown in FIG. 6 in a state where the vehicle is tilted laterally, the effective fluid amount in the third reservoir chamber 34 remains reduced. Thus, a state is established in which fluid does not recirculate from the second reservoir chamber 32 to the third reservoir chamber 34. When the VSC control is performed in such a state, the fluid level of the third reservoir chamber 34 falls below the height of the opening of the port 35 in a short time, and air suction may occur.

The reservoir tank 24 of the present embodiment allows the recirculation of fluid from the second reservoir chamber 32 to the third reservoir chamber 34 without increasing the size of the reservoir tank 24, and is used when the vehicle is tilted sideways. Is characterized in that a required amount of fluid can be secured in each reservoir chamber. FIG. 8 shows a configuration when the reservoir tank 24 of the present embodiment is viewed from the rear of the vehicle. As shown in FIG.
Has a slit 200 at the center thereof. The slit 200 is formed such that the height of the bottom thereof is the required height h. Therefore, when the fluid level of the second reservoir chamber 32 and the third reservoir chamber 34 exceeds the required height h, the fluid can move between the two reservoir chambers. That is, in the present embodiment, when the vehicle is not tilted laterally, the effective height of the partition wall 28 matches the required height h, and therefore, the fluid is moved from the second reservoir chamber 32 to the third reservoir chamber 32. It can recirculate to the reservoir chamber 34.

FIG. 9 is a view of the state in which the reservoir tank 24 is inclined in the vehicle lateral direction with the lateral inclination of the vehicle, as viewed from the rear of the vehicle. As shown in FIG. 9, in the present embodiment, since the slit 200 is provided at the center of the partition wall 28, even if the reservoir tank 24 is inclined in the vehicle lateral direction, the fluid at the bottom of the slit 200 with respect to the liquid level of the fluid is not formed. The relative height hardly changes. Therefore, according to the present embodiment, when the vehicle is tilted laterally while securing the state in which the fluid can be circulated from the second reservoir chamber 32 to the third reservoir chamber 34, the third reservoir chamber 34 Can be prevented from decreasing, and the fluid amount in the first reservoir chamber 30 and the second reservoir chamber 32 can be prevented from decreasing due to fluid leakage in the pump system.

As described above, according to the present embodiment, the second reservoir chamber 3 can be used without increasing the size of the reservoir tank 24.
Fluid recirculation from the second to the third reservoir chamber 34 can be enabled, and even when the vehicle is tilted, the first reservoir chamber 30, the second reservoir chamber 32, and the third reservoir chamber 34 require a required amount of fluid. Fluid can be secured. Therefore, according to the reservoir tank 24 of the present embodiment,
Irrespective of the inclination state of the vehicle, the occurrence of air suction can be prevented, and the normal braking function of the braking force control device can be reliably realized even when fluid leakage occurs in the pump system.

By the way, when the vehicle is running, the fluid in the reservoir tank 24 undulates with the vibration of the vehicle. When the fluid becomes wavy, the second reservoir chamber 32
Since the float sensor provided in the above-mentioned apparatus vibrates up and down, the fluid level cannot be accurately detected. On the other hand, in the reservoir tank 24, the partition 28
Is provided, unnecessary movement of fluid between the second reservoir chamber 32 and the third reservoir chamber 34 is suppressed. When the movement of the fluid is suppressed, the waving of the fluid is suppressed, so that the detection of the fluid level by the float sensor can be performed accurately.
As described above, the partition wall 28 also has a role of suppressing the surge of fluid in the reservoir tank 24, thereby enabling accurate detection of the fluid level by the float sensor.

From the viewpoint of suppressing the formation of fluid in the reservoir tank 24, it can be said that the partition wall 28 is preferably higher. In this embodiment, the slit 20 formed in the partition wall 28 is used.
With 0, the fluid is recirculated, so that portions other than the slit 200 can be provided sufficiently high. Therefore, the reservoir tank 24 of the present embodiment has an excellent performance in that it can more effectively detect the fluid level by the float sensor by effectively preventing the ripple of the fluid. Become.

As a configuration for preventing the fluid from waving while realizing the required height h, it is conceivable to provide slits on both sides of the partition wall 28 as shown in FIG.
However, in such a configuration, as shown in FIG. 11, when the vehicle is tilted laterally, the height of the fluid with respect to the liquid level at one end of the partition wall 28 decreases. Therefore, according to such a configuration, when the vehicle is tilted laterally, it is not possible to secure a required fluid amount in each reservoir room.

On the other hand, in the reservoir tank 24 of this embodiment, since the slit 200 is provided in the center of the partition wall 28 as described above, even if the vehicle is tilted sideways, It is possible to secure the required amount of fluid in the room. In the above embodiment, the slits 200 are provided in the partition wall 28. However, the present invention is not limited to this. For example, similar effects can be obtained by the configurations shown in FIGS. it can.

FIG. 12 shows an example in which a V-shaped slit is provided at the center of the partition wall 28. FIG. 13 shows an example in which the upper edge of the partition wall 28 is curved so that the central portion is the lowest.
As shown in FIGS. 12 and 13, by configuring the partition wall 28 so that the center portion thereof is lowest, the level of the fluid that can move beyond the partition wall 28 changes depending on the lateral inclination of the vehicle. Can be prevented. Therefore, even with the configuration of the partition wall 28 shown in FIGS. 12 and 134, the amount of fluid that can be secured in each reservoir chamber can be kept constant.

As shown in FIG. 8 and FIG.
In the configuration in which the slit is provided in the slit 8, the width of the slit may be set so as not to cause a large resistance when the fluid passes through the slit. Further, in the configuration shown in FIG. 12, the effect of preventing the surge of fluid in the reservoir tank 24 is reduced as compared with the case where the slit is provided. Therefore, in this case, for example,
By providing a plate-shaped member extending downward from the top wall surface of the reservoir tank 24 in the second reservoir chamber 32, it is possible to more effectively prevent the fluid from waving.

[0071]

As described above, according to the present invention, even when the reservoir tank is tilted, the required amount of fluid can be secured in each reservoir chamber while allowing fluid movement between the reservoir chambers. .

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a braking force control device to which a reservoir tank according to one embodiment of the present invention is applied.

FIG. 2 is a diagram showing a state where the braking force control device shown in FIG. 1 is in a VSC precharge mode.

FIG. 3 is a diagram showing a state in which the braking force control device shown in FIG. 1 is in a VSC pressure increasing mode.

FIG. 4 is a configuration diagram of the reservoir tank of the present embodiment as viewed from the side of the vehicle.

FIG. 5 is a diagram showing a state in which the vehicle leans forward in FIG. 4;

FIG. 6 is a diagram showing a state in which the fluid has moved forward of the vehicle as the vehicle decelerates in FIG.

FIG. 7 is a configuration diagram of the reservoir tank in a state where the vehicle is inclined sideways when the height of the partition wall is provided to be constant, as viewed from the rear of the vehicle.

FIG. 8 is a configuration diagram of the reservoir tank of the present embodiment as viewed from the rear of the vehicle.

FIG. 9 is a diagram showing a state in which the vehicle is tilted laterally in FIG.

FIG. 10 is a diagram showing a case where slits are provided on both sides of a partition.

FIG. 11 is a diagram showing a state in which the vehicle is tilted laterally in FIG.

FIG. 12 is a diagram showing an example in which a V-shaped slit is provided at the center of a partition.

FIG. 13 is a diagram showing an example in which an upper edge of a partition wall is formed in a curved shape.

[Explanation of symbols]

 16 Master cylinder 24 Reservoir tank 28 Partition wall 32 Second reservoir chamber 34 Third reservoir chamber 136 Front pump 138 Rear pump 200 Slit

Claims (1)

[Claims] 1. A reservoir tank having a plurality of reservoir chambers partitioned by a partition wall and communicating with each other above the partition wall, wherein at least one of the partition walls is configured so that a central portion thereof is lowest. Reservoir tank.