JP3775110B2 - Regenerative cooperative brake hydraulic pressure control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a hybrid vehicle that uses an engine and an electric motor in combination, and an electric vehicle that uses an electric motor as a prime mover, and regenerative cooperative brake hydraulic pressure control that controls the brake hydraulic pressure to a wheel cylinder in concert with motor regenerative braking. It belongs to the technical field of equipment.
[0002]
[Prior art]
Conventionally, as a regenerative cooperative brake hydraulic pressure control device, for example, a device described in Japanese Patent Laid-Open No. 10-014008 is known.
[0003]
In this publication, a regenerative switching valve that cuts off the communication between the master cylinder and the wheel cylinder at the time of regenerative cooperative braking, a hydraulic pressure control valve that creates a brake hydraulic pressure to the wheel cylinder that is reduced by the regenerative braking force at the time of regenerative cooperative braking, An absorption cylinder that absorbs the brake fluid from the master cylinder by the amount of decrease in the amount of fluid consumed during decompression by regenerative cooperative braking, and the brake fluid amount to the wheel cylinder is restored and increased when returning to normal braking from regenerative cooperative braking. A regenerative cooperative brake hydraulic pressure control device having a pressure increasing cylinder for pressurization is shown.
[0004]
[Problems to be solved by the invention]
However, in the conventional regenerative cooperative brake fluid pressure control device, the brake fluid from the master cylinder is absorbed so that the operator does not feel uncomfortable during regenerative cooperative braking in which communication between the master cylinder and the wheel cylinder is interrupted. In the case of normal braking where hydraulic pressure adjustment is not required, the operation of the absorption cylinder can be electrically activated or deactivated. There is a problem that a means for switching is required, and the apparatus becomes complicated and expensive.
[0005]
In addition, when the regenerative braking force disappears, if the wheel cylinder pressure is not quickly raised to the master cylinder pressure level, the deceleration of the vehicle will decrease, so a pressure increasing mechanism (pressure increasing cylinder) that increases only the wheel cylinder pressure. ) Is required, and the apparatus is complicated and expensive.
[0006]
Furthermore, since such a regenerative cooperative brake hydraulic pressure control device is limited to a special vehicle, the production quantity is small. As shown in FIG. There was a problem of becoming expensive.
[0007]
The problem to be solved by the present invention is to provide a regenerative cooperative brake hydraulic pressure control device having a function necessary for regenerative cooperation with a very inexpensive mechanism capable of sharing parts based on a skid prevention device. is there.
[0008]
[Means for Solving the Problems]
The means for solving the above problems are as follows.
[0009]
In the first aspect of the invention, a master cylinder having a brake fluid reservoir and generating a master cylinder pressure corresponding to the pedal depression force;
A wheel cylinder that applies braking force to each wheel according to the wheel cylinder pressure to be guided;
A regeneration coordinating unit and an ABS actuator arranged between the master cylinder and the wheel cylinder;
During regenerative cooperative braking, the regenerative cooperative brake controls the brake hydraulic pressure supplied to the wheel cylinders so that the total braking force, which is the sum of the hydraulic braking force and the regenerative braking force, matches the braking force that should be obtained by the brake operation. In the hydraulic control device,
A main communication path switching valve that is provided in the middle of the main communication path from the master cylinder to the wheel cylinder and blocks communication during regenerative cooperative braking;
A check valve provided in the middle of a secondary communication path from the brake fluid reservoir to the wheel cylinder via the ABS pump built in the ABS actuator and allowing only the brake fluid flow in the direction from the brake fluid reservoir to the ABS pump;
An absorption cylinder that is provided in a main communication path between the master cylinder and the main communication path switching valve, and absorbs a liquid amount from the master cylinder so as to have a normal hydraulic pressure liquid amount characteristic during regenerative cooperative braking;
Regenerative cooperation department with
At the time of regenerative cooperative braking, the ABS pump is controlled by ABS pump control means for controlling the wheel cylinder pressure to be a target pressure based on the hydraulic pressure detection values from the master cylinder pressure sensor and the wheel cylinder pressure sensor.
[0010]
In invention of Claim 2, in the regeneration cooperation brake hydraulic pressure control apparatus of Claim 1,
The check valve is a sub-communication path switching valve that is normally closed and opened during regenerative cooperative braking.
[0011]
In invention of Claim 3, in the regeneration cooperation brake hydraulic pressure control apparatus of Claim 1 or Claim 2,
The bypass passage that bypasses the main communication passage switching valve is provided with a differential pressure valve that opens when a differential pressure greater than the maximum differential pressure by the hydraulic pressure control occurs, and sends brake fluid from the master cylinder to the wheel cylinder. To do.
[0012]
According to a fourth aspect of the present invention, in the regenerative cooperative brake hydraulic pressure control device according to the first to third aspects,
A pressure reducing switching valve that is provided in an oil passage that branches from between the main communication path switching valve and the wheel cylinder and that is normally closed to further reduce the wheel cylinder pressure, and a brake fluid that has been added to the wheel cylinder Is provided with a hydraulic pressure absorption cylinder, a part of which is guided through an open pressure reducing switching valve.
[0013]
In invention of Claim 5, in the regeneration cooperation brake hydraulic pressure control apparatus of Claim 1 thru | or 3,
The oil passage that branches from between the main communication passage switching valve and the wheel cylinder is provided with a pressure reduction switching valve that is normally closed and opened when a pressure reduction request is made to further reduce the wheel cylinder pressure. A part is characterized in that it leads to the brake fluid reservoir via an open decompression switching valve.
[0014]
In invention of Claim 6, in the regeneration cooperation brake hydraulic pressure control apparatus of Claim 1 thru | or 3,
The absorption capacity of the ABS reservoir built in the ABS actuator is enlarged, and the pressure reduction control valve of the ABS actuator is operated when a pressure reduction request for further reducing the wheel cylinder pressure is made.
[0015]
Operation and effect of the invention
In the first aspect of the invention, the main communication path switching valve is opened during normal braking. Then, the hydraulic pressure from the master cylinder is a normal hydraulic pressure transmission that passes through the main communication path and is supplied to the wheel cylinder as it is.
[0016]
Conversely, during regenerative cooperative braking, the main communication path switching valve is closed. Then, the hydraulic pressure generated in the master cylinder by the brake operation is guided to the absorption cylinder. Since this absorption cylinder absorbs the fluid amount so as to have the same hydraulic fluid amount characteristic as that during normal braking, the brake operator does not feel uncomfortable.
[0017]
At the same time, the pressure generated by operating the ABS pump is supplied to the wheel cylinder from the brake fluid reservoir via the check valve and the ABS pump built in the ABS actuator to the wheel cylinder. At this time, it is necessary for the master cylinder pressure and the wheel cylinder pressure when the pressure is reduced in the ABS pump control means based on the signal from the master cylinder pressure sensor for detecting the master cylinder pressure and the wheel cylinder pressure sensor for detecting the wheel cylinder pressure. The ABS pump is controlled to add a sufficient pressure difference. In addition, when the regenerative cooperative braking is finished, it is necessary to quickly increase the hydraulic pressure applied to the wheel cylinder to a level equivalent to the master cylinder pressure. The ABS pump is controlled by using the detected master cylinder pressure as the target pressure of the wheel cylinder. When the wheel cylinder pressure becomes equal to the master cylinder pressure, the main communication path switching valve is opened and the normal braking state is restored.
[0018]
Thus, like the skid prevention device, the communication path of the master cylinder and the wheel cylinder is doubled by the main communication path and the sub communication path, and the main communication path during normal braking and the other sub communication path are separated, The main communication path has a main communication path switching valve that switches between opening and closing depending on the situation. This main communication path switching valve is the same as the switching valve used in the skid prevention device and can be shared.
[0019]
In addition, the absorption cylinder is intended for absorption only while the main communication switching valve is in the shut-off state, so the amount of absorption is small, and even if it malfunctions during normal braking, the brake feeling will be slightly strange. It is a grade that occurs and has little impact. For this reason, it is not necessary to provide a dedicated switching valve as in the conventional apparatus to switch the operation / non-operation of the absorption cylinder, and this function can be shared by opening and closing the main communication path switching valve.
[0020]
Furthermore, since the pressure reducing function and the pressure increasing function use the ABS pump of the ABS actuator, it is not necessary to add a separate mechanism for reducing or increasing only the wheel cylinder pressure.
[0021]
Therefore, it is possible to provide a regenerative cooperative brake hydraulic pressure control device having a function necessary for regenerative cooperation with a very inexpensive mechanism that can share parts based on the skid prevention device.
[0022]
Further, the reason for using the check valve in the secondary communication path will be described. The secondary communication path from the brake fluid reservoir via the ABS pump to the wheel cylinder is independent of the main communication path from the master cylinder to the wheel cylinder. It is. Therefore, the switching function is required only for the main communication path, and it is not necessary to provide a sub-communication path switching valve in this sub-communication path, and only the brake fluid flow in the direction from the brake fluid reservoir to the ABS pump is allowed. There is no problem even if it is replaced with a check valve.
[0023]
Therefore, one solenoid valve is not required, and the regenerative coordination unit can be reduced in size, simplified, and reduced in cost, and valve switching control is also unnecessary.
[0024]
In the invention described in claim 2, a sub-communication path switching valve is provided in place of the check valve, the sub-communication path switching valve is closed during normal operation, and the sub-communication path switching valve is opened during regenerative cooperative braking. It is said. Thus, the same effect as that of claim 1 is achieved.
[0025]
Therefore, it is possible to provide a regenerative cooperative brake hydraulic pressure control device having a function necessary for regenerative cooperation with a very inexpensive mechanism that can share parts based on the skid prevention device. In other words, when considering sharing parts with the skid prevention device, the two communication passages are each provided with a switching valve. Even if a main communication passage switching valve and a sub-communication passage switching valve are provided, the components can be shared. Can be planned.
[0026]
In the invention according to claim 3, provided in the bypass path that bypasses the main communication path switching valve when the differential pressure between the master cylinder pressure and the wheel cylinder pressure by the hydraulic pressure control is greater than or equal to the maximum differential pressure during regenerative cooperative braking. The specified differential pressure valve opens, and the differential pressure between both cylinders is regulated to the maximum differential pressure. Then, when the main communication path switching valve is switched to the closed side, the master cylinder and the wheel cylinder are shut off, and if a failure or the like occurs in this shut off state, the brake fluid is passed through the differential pressure valve provided in the bypass path. Can be sent to the wheel cylinder.
[0027]
Therefore, by providing a differential pressure valve on the bypass path that bypasses the main communication path switching valve, the differential pressure between the cylinder pressures can be regulated up to the maximum differential pressure, and at the same time, the main communication path switching valve can be controlled in the event of a breakdown failure. A decrease in power can be prevented.
[0028]
In the fourth aspect of the invention, when the regenerative braking force increases in the reduced pressure control state during regenerative cooperative braking due to the vehicle speed, the capacity of the storage battery, etc., the hydraulic pressure applied to the wheel cylinder is reduced. Further decompression is required. At this time, the decompression switching valve provided in the oil passage branched from between the main communication path switching valve and the wheel cylinder is opened. Thereby, a part of the hydraulic pressure applied to the wheel cylinder is guided to the hydraulic pressure absorption cylinder. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinder is reduced.
[0029]
Therefore, by providing the pressure reduction switching valve and the hydraulic pressure absorption cylinder, when a further pressure reduction request is issued during regenerative cooperative braking, pressure reduction control can be achieved in response to this.
[0030]
In addition, when a failure occurs in which the pressure reducing switching valve remains open, the hydraulic pressure generated by the master cylinder only decreases by the amount absorbed by the hydraulic pressure absorption cylinder, so that the braking force of one system is completely lost. There is nothing. In other words, by setting the hydraulic pressure absorption amount of the hydraulic pressure absorption cylinder to about the maximum regenerative amount equivalent hydraulic pressure, it is possible to regulate the reduction of the braking force.
[0031]
According to the fifth aspect of the present invention, when a further pressure reduction request is issued during regenerative cooperative braking, the pressure reduction switching valve provided in the oil passage branched from between the main communication path switching valve and the wheel cylinder is opened. Thereby, a part of the hydraulic pressure applied to the wheel cylinder is guided to the brake fluid reservoir. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinder is reduced.
[0032]
Therefore, by providing a pressure reduction switching valve, when a further pressure reduction request is issued during regenerative cooperative braking, pressure reduction control can be achieved in response to this.
[0033]
Further, by using an existing brake fluid reservoir instead of the hydraulic pressure absorption cylinder, it is possible to suppress an increase in the size and price of the device when compared with the invention according to claim 4 using the hydraulic pressure absorption cylinder. .
[0034]
In the invention described in claim 6, when a further pressure reduction request is issued during regenerative cooperative braking, the pressure reduction control valve of the ABS actuator is operated. As a result, a part of the hydraulic pressure applied to the wheel cylinder is guided to the ABS reservoir having an increased absorption capacity. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinder is reduced.
[0035]
Therefore, if a further pressure reduction request is issued during regenerative coordinated braking only by increasing the absorption capacity of the ABS reservoir of the ABS actuator, pressure reduction control can be achieved in response to this.
[0036]
Further, since the pressure reducing control valve of the ABS actuator is used, parts can be shared with the ABS actuator, and the device can be further reduced in size and cost.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
The first embodiment is a regenerative cooperative brake hydraulic pressure control device corresponding to the first, third, and fourth aspects of the invention.
[0038]
FIG. 1 is a diagram of a regenerative cooperative brake system to which the regenerative cooperative brake hydraulic pressure control device according to the first embodiment is applied. This regenerative cooperative brake system cooperates with a motor regenerative braking with respect to a conventional brake using only hydraulic pressure. This system aims to improve fuel efficiency by controlling brake fluid pressure.
[0039]
In FIG. 1, 1 is a brake pedal, 2 is a negative pressure booster, 3 is a master cylinder, 4 is a brake fluid reservoir, 5 is an engine, 6 is a regeneration coordinating unit, 7 is an ABS actuator, 8FR, 8RL, 8RR, and 8FL are wheels. Cylinder, 9 is a pedal switch, 10 is a primary master cylinder pressure sensor, 11 is a primary wheel cylinder pressure sensor, 12 is a secondary master cylinder pressure sensor, and 13 is a secondary wheel cylinder pressure sensor.
[0040]
The master cylinder 3 increases the pedal depression force to the brake pedal 1 by the negative pressure booster 2 and generates a master cylinder pressure corresponding to the pedal depression force.
[0041]
Each of the wheel cylinders 8FR, 8RL, 8RR, 8FL applies to each wheel a braking force corresponding to the wheel cylinder pressure guided from the master cylinder 3 via the regeneration coordinating unit 6 and the ABS actuator 7.
[0042]
The regenerative cooperation unit 6 is disposed between the master cylinder 3 and the ABS actuator 7 and is controlled by the braking force obtained by regenerative braking and the brake fluid pressure applied to the wheel cylinders 8FR, 8RL, 8RR, and 8FL during regenerative cooperative braking. The master cylinder pressure is controlled to be reduced so that the sum of the power and the required braking force by the master cylinder pressure matches.
[0043]
The ABS actuator 7 is disposed between the regeneration coordinating unit 6 and the wheel cylinders 8FR, 8RL, 8RR, 8FL, and locks the brake during low μ road braking or sudden braking where the braking lock occurs. The brake fluid pressure of each wheel cylinder 8FR, 8RL, 8RR, 8FL is controlled so as to be suppressed.
[0044]
In the regeneration coordination unit 6, PSP and PSS are main communication path switching valves, CH is a check valve, SSP and SSS are absorption cylinders, DPP and DPS are differential pressure valves, CSDP and CSDS are pressure reduction switching valves, and DCP and DCS are hydraulic pressures. Absorption cylinders, MRP, MRS are main communication passages, SR are sub-communication passages, RRP, RRS are bypass passages, and in ABS actuator 7, 30FR, 30RL, 30RR, 30FL are pressure increase control valves, 31FR, 31RL, 31RR, 31FL is a pressure reducing control valve, 32P and 32S are ABS reservoirs, 33P and 33S are ABS pumps, 34P and 34S are pump discharge side oil passages, and 35P and 35S are pump suction side oil passages. In addition, since P represents primary and S represents secondary, hereinafter, P and S at the end are omitted.
[0045]
The main communication path switching valve PS is provided in the middle of the main communication path MR from the master cylinder 3 to the wheel cylinders 8FR, 8RL, 8RR, and 8FL via the pump discharge side oil path 34 of the ABS actuator 7, and regenerative cooperative braking. Sometimes block communication.
[0046]
The check valve CH is provided in the middle of the auxiliary communication path SR from the brake fluid reservoir 4 to the wheel cylinders 8FR, 8RL, 8RR, 8FL via the ABS pump 33 built in the ABS actuator 7. Only the brake fluid flow in the direction to the ABS pump 33 is allowed.
[0047]
The absorption cylinder SS is provided in the main communication path MR between the master cylinder 3 and the main communication path switching valve PS, and the liquid volume from the master cylinder 3 is set so as to have a normal hydraulic pressure liquid volume characteristic during regenerative cooperative braking. To absorb.
[0048]
The differential pressure valve DP is provided in a bypass path RR that bypasses the main communication path switching valve PS, and opens when a differential pressure greater than the maximum differential pressure by the hydraulic pressure control occurs, and brake fluid from the master cylinder 3 is supplied to the wheel cylinder 8FR. , 8RL, 8RR, 8FL.
[0049]
The depressurization switching valve CSD is provided in an oil passage that branches from between the main communication path switching valve PS and the wheel cylinders 8FR, 8RL, 8RR, and 8FL, and is normally closed and is opened when a depressurization request for further depressurizing the wheel cylinder pressure is made. .
[0050]
In the hydraulic pressure absorption cylinder DC, a part of the brake fluid added to the wheel cylinders 8FR, 8RL, 8RR, 8FL is guided through the opened pressure reducing switching valve CSD.
[0051]
The ABS pump 33 performs control to control the wheel cylinder pressure as a target pressure based on the hydraulic pressure detection values from the master cylinder pressure sensors 10, 12 and the wheel cylinder pressure sensors 11, 13 during regenerative cooperative braking. The operation is controlled by a controller (ABS pump control means).
[0052]
Next, the operation will be described.
[0053]
[Normal braking]
In normal braking that does not satisfy the regenerative cooperative braking condition or fail safe due to electrical failure, etc., the solenoid valves PS and CS of the regenerative cooperative unit 6 are in the solenoid OFF position shown in FIG. 1, that is, the main communication path switching valve PS. open.
[0054]
Therefore, when the brake operation for depressing the brake pedal 1 is performed, the brake fluid pressure generated in the master cylinder 3 passes through the main communication path MR (main communication path switching valve PS) → the ABS actuator 7 and remains in the wheel cylinders 8FR, 8RL. , 8RR, 8FL, and a braking force by the master cylinder pressure is applied to each wheel.
[0055]
[When using regenerative cooperative braking]
Conversely, during regenerative cooperative braking, the main communication path switching valve PS is closed. Then, the hydraulic pressure generated in the master cylinder 3 by the brake operation is guided to the absorption cylinder SS. Since this absorption cylinder SS absorbs the fluid amount so as to have the same hydraulic fluid amount characteristic as that during normal braking, it does not give the brake operator a sense of incongruity.
[0056]
At the same time, the ABS pump 33 is operated by using the auxiliary communication path from the brake fluid reservoir 4 to the wheel cylinders 8FR, 8RL, 8RR, 8FL via the check valve CH and the ABS pump 33 incorporated in the ABS actuator 7. The generated pressure is supplied to the wheel cylinders 8FR, 8RL, 8RR, 8FL. At this time, in the ABS pump controller based on signals from the master cylinder pressure sensors 10 and 12 for detecting the master cylinder pressure and the wheel cylinder pressure sensors 11 and 13 for detecting the wheel cylinder pressure, the master cylinder pressure and the wheel at the time of pressure reduction are determined. The ABS pump 33 is controlled to add a necessary pressure difference to the cylinder pressure. Further, when the regenerative cooperative braking is finished, it is necessary to quickly increase the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, and 8FL to a level equivalent to the master cylinder pressure. In the ABS pump controller, the ABS pump 33 is controlled to operate with the detected master cylinder pressure as the target pressure of the wheel cylinders 8FR, 8RL, 8RR, 8FL. When the Hall cylinder pressure becomes equal to the master cylinder pressure, the main communication path switching valve PS is opened and the normal braking state is restored.
[0057]
During the regenerative cooperative control, the master cylinder 3 and the wheel cylinders 8FR, 8RL, 8RR, and 8FL are disconnected. At this time, if the operator operates the brake pedal 1 to change the generated hydraulic pressure, the sensor signals from the master cylinder pressure sensors 10 and 12 change, so the necessary braking force calculated based on this detected value. The difference between the regenerative braking force and the regenerative braking force is set as the target wheel cylinder pressure, and the pressure is increased by the ABS pump 33, or the pressure reducing switching valve CSD is operated to reduce the pressure using the hydraulic pressure absorbing cylinder DC.
[0058]
Incidentally, FIG. 2 is a time chart showing an example of the control by the regenerative cooperative system. The vehicle braking force starts to increase due to the start of the brake operation at time t0, reaches the vehicle braking force peak at time t1, and is regenerated at time t2. The braking force starts to increase, the regenerative braking force reaches its peak at time t3, the vehicle braking force starts to decrease at time t4, the vehicle braking force bottoms at time t5, and the vehicle braking force at time t6. The increase starts, the vehicle braking force reaches a peak at t7, the regenerative braking force starts decreasing at the time t8, the regenerative braking force becomes zero at the time t9, and the vehicle braking force is released along with the brake release operation at the time t10. This is an example in which the power becomes zero.
[0059]
In this case, the main communication path switching valve PS is kept ON (not connected) from the time t0 to t10. The depressurization switching valve CSD includes a region from t2 to t3 in which the wheel cylinder pressure needs to be reduced by increasing the regenerative braking force, and t4 to which the vehicle braking force is reduced by the accelerator return operation and the wheel cylinder pressure needs to be reduced. Operates in the region of t5. The ABS pump 33 operates in a region from t0 to t1, a region from t6 to t7, and a region from t8 to t9, and increases necessary wheel cylinder pressure.
[0060]
Next, the effect will be described.
[0061]
(1) It is possible to provide a regenerative cooperative brake hydraulic pressure control device having a function necessary for regenerative cooperation with a very inexpensive mechanism capable of sharing parts based on a skid prevention device. The reason is described below.
[0062]
In the first embodiment, the communication path between the master cylinder 3 and the wheel cylinders 8FR, 8RL, 8RR, 8FL is used as the main communication path in the same manner as in the skid prevention device (Japanese Patent Laid-Open No. 10-278765, etc.) as shown in FIG. The main communication path MR is separated from the main communication path MR and the other sub communication path SR during normal braking, and the main communication path MR has a main communication path switching valve PS that switches between opening and closing depending on the situation. is doing. The main communication path switching valve PS is the same as the switching valve used in the skid prevention device and can be shared.
[0063]
In addition, the absorption cylinder SS is intended for absorption only while the main communication switching valve PS is in the shut-off state, so the amount of absorption is small, and even if it malfunctions during normal braking, the brake feeling is slight. The level of discomfort is small and the impact is small. For this reason, unlike the conventional apparatus, it is not necessary to provide a dedicated switching valve to switch the operation / non-operation of the absorption cylinder SS, and this function can be shared by opening and closing the main communication path switching valve PS.
[0064]
Furthermore, since the pressure reducing function and the pressure increasing function use the ABS pump 33 of the ABS actuator 7, it is not necessary to add a separate mechanism for reducing or increasing only the wheel cylinder pressure.
[0065]
(2) Since the check valve CH is used in the sub-communication path SR, one solenoid valve is not required compared to the case where a solenoid switching valve is provided in the sub-communication path SR, and the regenerative coordination unit 6 can be downsized. Simplification and cost reduction can be achieved, and valve switching control is not required.
[0066]
Here, the reason why the check valve CH is used for the sub-communication passage SR will be described. The sub-communication passage SR from the brake fluid reservoir 4 via the ABS pump 33 to the wheel cylinders 8FR, 8RL, 8RR, 8FL is connected to the master cylinder 3. It is a path independent of the main communication path MR that reaches the wheel cylinders 8FR, 8RL, 8RR, and 8FL as a starting point. Therefore, only the main communication path MR requires the switching function, and it is not necessary to provide a sub communication path switching valve in the sub communication path SR. Brake fluid in the direction from the brake fluid reservoir 4 to the ABS pump 33 is not required. There is no problem even if it is replaced with a check valve CH that allows only flow.
[0067]
(3) By providing the differential pressure valve DP in the bypass path RR that bypasses the main communication path switching valve PS, the differential pressure between the master cylinder pressure and the wheel cylinder pressure can be regulated up to the maximum differential pressure. It is possible to prevent a reduction in braking force when the communication path switching valve PS is shut off.
[0068]
That is, when the differential pressure between the master cylinder pressure and the wheel cylinder pressure by the hydraulic pressure control becomes greater than or equal to the maximum differential pressure during regenerative cooperative braking, the differential pressure valve DP provided in the bypass path RR that bypasses the main communication path switching valve PS is Open and define the differential pressure between both cylinders up to the maximum differential pressure. When the main communication path switching valve PS is switched to the closed side, the master cylinder 3 and the wheel cylinders 8FR, 8RL, 8RR, 8FL are cut off. If a failure or the like occurs in this cut off state, the master cylinder 3 and the wheel cylinders 8FR, 8RL, 8RR, 8FL are provided on the bypass path RR. The brake fluid can be sent to the wheel cylinders 8FR, 8RL, 8RR, 8FL via the differential pressure valve DP.
[0069]
(4) By providing the pressure reduction switching valve CSD and the hydraulic pressure absorption cylinder DC, when a further pressure reduction request is issued during regenerative cooperative braking, pressure reduction control can be achieved in response to this.
[0070]
That is, when the regenerative braking force increases in the reduced pressure control state during regenerative cooperative braking due to the vehicle speed, the capacity of the storage battery, etc., the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, 8FL is further reduced. There is a need to. At this time, the pressure reduction switching valve CSD provided in the oil passage branched from between the main communication path switching valve PS and the wheel cylinders 8FR, 8RL, 8RR, 8FL is opened. As a result, part of the hydraulic pressure added to the wheel cylinders 8FR, 8RL, 8RR, 8FL is guided to the hydraulic pressure absorption cylinder DC. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, 8FL is reduced.
[0071]
(5) When a failure occurs in which the depressurization switching valve CSD remains open, the hydraulic pressure generated by the master cylinder 3 is only reduced by the absorption in the hydraulic pressure absorption cylinder DC. It will not disappear completely.
[0072]
That is, by setting the hydraulic pressure absorption amount of the hydraulic pressure absorption cylinder DC to about the maximum regenerative amount equivalent hydraulic pressure, it is possible to regulate the reduction of the braking force.
[0073]
(Embodiment 2)
The second embodiment is a regenerative cooperative brake hydraulic pressure control device corresponding to the inventions described in claims 2, 3, and 4.
[0074]
FIG. 3 is a diagram of a regenerative cooperative brake system to which the regenerative cooperative brake hydraulic pressure control device according to the second embodiment is applied. Instead of the check valve CH used in the first embodiment, the regenerative cooperative brake is normally closed. This is an example in which a sub-communication path switching valve CSB that is sometimes opened is provided. Since other configurations are the same as those in FIG. 1 of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.
[0075]
In the second embodiment, the auxiliary communication path switching valve CSB is closed during normal times, and the auxiliary communication path switching valve CSB is opened during regenerative cooperative braking. As a result, the same operation as in the first embodiment is achieved.
[0076]
Therefore, it is possible to provide a regenerative cooperative brake hydraulic pressure control device having a function necessary for regenerative cooperation with a very inexpensive mechanism that can share parts based on the skid prevention device. That is, when considering the sharing of parts with the skid prevention device shown in FIG. 7, the two communication paths are also provided with switching valves in FIG. 7, respectively. Even if the switching valve PS and the sub-communication path switching valve CSB are provided, parts can be shared.
[0077]
(Embodiment 3)
The third embodiment is a regenerative cooperative brake hydraulic pressure control device corresponding to the first, third, and fifth aspects of the invention.
[0078]
FIG. 4 is a diagram of a regenerative cooperative brake system to which the regenerative cooperative brake hydraulic pressure control device of the third embodiment is applied, and the oil branches between the main communication path switching valve PS and the wheel cylinders 8FR, 8RL, 8RR, 8FL. There is a pressure reducing switching valve that is normally closed and opened when a pressure reduction request is made to further reduce the wheel cylinder pressure, and a part of the brake fluid added to the wheel cylinders 8FR, 8RL, 8RR, 8FL through the pressure reducing switching valve is provided. This is an example of leading to the brake fluid reservoir 4. That is, in the first embodiment, the brake fluid reservoir 4 is used instead of the hydraulic pressure absorption cylinder DC. Since other configurations are the same as those in FIG. 1 of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.
[0079]
In the third embodiment, when a further pressure reduction request is issued during regenerative cooperative braking, a pressure reduction switching valve provided in an oil passage that branches from between the main communication path switching valve PS and the wheel cylinders 8FR, 8RL, 8RR, 8FL. Open CSD. Thereby, a part of the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, 8FL is guided to the brake fluid reservoir 4. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, 8FL is reduced.
[0080]
Therefore, by providing the pressure reduction switching valve CSD, when a further pressure reduction request is issued during regenerative cooperative braking, pressure reduction control can be achieved in response to this.
[0081]
Further, by using the existing brake fluid reservoir 4 instead of the fluid pressure absorption cylinder DC, it is possible to suppress the increase in size and price of the device as compared with the case where the fluid pressure absorption cylinder DC is used.
[0082]
(Embodiment 4)
The fourth embodiment is a regenerative cooperative brake hydraulic pressure control device corresponding to the first, third, and sixth aspects of the invention.
[0083]
FIG. 5 is a diagram of a regenerative cooperative brake system to which the regenerative cooperative brake hydraulic pressure control device of the fourth embodiment is applied. The absorption capacity of the ABS reservoir 32 built in the ABS actuator 7 is expanded to further increase the wheel cylinder pressure. The pressure reduction control valves 31FR, 31RL, 31RR, and 31FL of the ABS actuator 7 are operated when a pressure reduction request for pressure reduction is required. Since other configurations are the same as those in FIG. 1 of the first embodiment, the corresponding components are denoted by the same reference numerals and description thereof is omitted.
[0084]
In the fourth embodiment, when a further pressure reduction request is issued during regenerative cooperative braking, the pressure reduction control valves 31FR, 31RL, 31RR, and 31FL of the ABS actuator 7 are operated. As a result, part of the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, and 8FL is guided to the ABS reservoir 32 having an increased absorption capacity. As a result, the volume of the formed circuit is increased, so that the hydraulic pressure applied to the wheel cylinders 8FR, 8RL, 8RR, 8FL is reduced.
[0085]
Therefore, only by increasing the absorption capacity of the ABS reservoir 32 of the ABS actuator 7, when a further pressure reduction request is issued during regenerative cooperative braking, pressure reduction control can be achieved in response to this.
[0086]
Further, since the pressure reducing control valves 31FR, 31RL, 31RR, and 31FL of the ABS actuator 7 are used, parts can be shared with the ABS actuator 7, and the device can be further reduced in size and cost.
[Brief description of the drawings]
FIG. 1 is an overall system diagram showing a regenerative cooperative brake hydraulic pressure control apparatus according to a first embodiment.
FIG. 2 is a diagram showing a regeneration coordination system time chart in the regeneration coordination brake hydraulic pressure control apparatus of the first embodiment.
FIG. 3 is an overall system diagram showing a regenerative cooperative brake hydraulic pressure control apparatus according to a second embodiment.
4 is an overall system diagram showing a regenerative cooperative brake hydraulic pressure control apparatus according to a third embodiment. FIG.
FIG. 5 is an overall system diagram showing a regenerative cooperative brake hydraulic pressure control apparatus according to a fourth embodiment.
FIG. 6 is a hydraulic circuit diagram showing a regenerative cooperative brake hydraulic pressure control device during conventional regenerative cooperation.
FIG. 7 is a hydraulic circuit diagram showing a conventional skid prevention device.
[Explanation of symbols]
1 Brake pedal
2 Negative pressure booster
3 Master cylinder
4 Brake fluid reservoir
5 Engine
6th Regeneration Cooperation Department
7 ABS actuator
8FR, 8RL, 8RR, 8FL Wheel cylinder
9 Pedal switch
10 Primary master cylinder pressure sensor
11 Primary wheel cylinder pressure sensor
12 Secondary master cylinder pressure sensor
13 Secondary wheel cylinder pressure sensor
PSP, PSS main communication path switching valve
CH Check valve
SSP, SSS Absorption cylinder
DPP, DPS Differential pressure valve
CSDP, CSDS Pressure reducing switching valve
DCP, DCS Hydraulic absorption cylinder
MRP, MRS main communication path
SR Secondary communication passage
RRP, RRS bypass
31FR, 31RL, 31RR, 31FL Pressure reducing control valve
32P, 32S ABS reservoir
33P, 33S ABS pump
34P, 34S Pump discharge side oil passage
35P, 35S Pump suction side oil passage

Claims (6)

A master cylinder having a brake fluid reservoir and generating a master cylinder pressure corresponding to the pedal depression force;
A wheel cylinder that applies braking force to each wheel according to the wheel cylinder pressure to be guided;
A regeneration coordinating unit and an ABS actuator arranged between the master cylinder and the wheel cylinder;
During regenerative cooperative braking, the regenerative cooperative brake controls the brake hydraulic pressure supplied to the wheel cylinders so that the total braking force, which is the sum of the hydraulic braking force and the regenerative braking force, matches the braking force that should be obtained by the brake operation. In the hydraulic control device,
A main communication path switching valve that is provided in the middle of the main communication path from the master cylinder to the wheel cylinder and blocks communication during regenerative cooperative braking;
A check valve provided in the middle of a secondary communication path from the brake fluid reservoir to the wheel cylinder via the ABS pump built in the ABS actuator and allowing only the brake fluid flow in the direction from the brake fluid reservoir to the ABS pump;
An absorption cylinder that is provided in a main communication path between the master cylinder and the main communication path switching valve, and absorbs a liquid amount from the master cylinder so as to have a normal hydraulic pressure liquid amount characteristic during regenerative cooperative braking;
Regenerative cooperation department with
During regenerative coordinated braking, the ABS pump is controlled by ABS pump control means for controlling the wheel cylinder pressure to be a target pressure based on hydraulic pressure detection values from the master cylinder pressure sensor and the wheel cylinder pressure sensor. Cooperative brake fluid pressure control device. In the regenerative cooperative brake hydraulic pressure control device according to claim 1,
A regenerative cooperative brake hydraulic pressure control device, wherein the check valve is a sub-communication path switching valve that is normally closed and opened during regenerative cooperative braking. In the regeneration cooperative brake hydraulic pressure control device according to claim 1 or 2,
The bypass passage that bypasses the main communication passage switching valve is provided with a differential pressure valve that opens when a differential pressure greater than the maximum differential pressure by the hydraulic pressure control occurs, and sends brake fluid from the master cylinder to the wheel cylinder. Regenerative cooperative brake hydraulic pressure control device. In the regenerative cooperative brake hydraulic pressure control device according to any one of claims 1 to 3,
A pressure reducing switching valve that is provided in an oil passage that branches from between the main communication path switching valve and the wheel cylinder and that is normally closed and that further opens the pressure of the wheel cylinder when a pressure reduction request is made; and the wheel cylinder via the pressure reducing switching valve A regenerative cooperative brake hydraulic pressure control device is provided with a hydraulic pressure absorbing cylinder through which a part of the brake fluid added to the cylinder is guided. In the regenerative cooperative brake hydraulic pressure control device according to any one of claims 1 to 3,
The oil passage that branches from between the main communication passage switching valve and the wheel cylinder is provided with a pressure reduction switching valve that is normally closed and opened when a pressure reduction request is made to further reduce the wheel cylinder pressure, and is connected to the wheel cylinder via the pressure reduction switching valve. A regenerative cooperative brake fluid pressure control device that guides a part of the added brake fluid to a brake fluid reservoir. In the regenerative cooperative brake hydraulic pressure control device according to any one of claims 1 to 3,
A regenerative cooperative brake hydraulic pressure control device that operates a pressure reduction control valve of an ABS actuator when a pressure reduction request for further reducing the wheel cylinder pressure is performed by increasing the absorption capacity of an ABS reservoir built in the ABS actuator.

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