JPH07250401A - Brake controller for electric automobile - Google Patents

Abstract

PURPOSE:To enhance regeneration of energy without sacrifice of brake feeling when the regenerative braking is recovered after increase of hydraulic brake power. CONSTITUTION:Upon failure of regenerative braking, hydraulic pressure is introduced from the internal reservoir 72 or the master cylinder(M/C) 28 in an antilock brake system(ABS) 62 to a wheel cylinder(W/C) 32 through linear valves 304, 30 for the purpose of compensation. Upon recovery of regenerative braking, the state of linear valve 304, 306 us switched to drain the oil from the W/C 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking control which is mounted on an electric vehicle and controls distribution of regenerative braking force and hydraulic braking force so as to match the required braking force and the regenerative braking force is preferentially used. Regarding the device.

[0002]

2. Description of the Related Art Hydraulic braking, such as hydraulic braking, is widely used as braking means for vehicles. The hydraulic braking mechanism usually includes a master cylinder (M / C) that generates hydraulic pressure in response to depression of a brake pedal, a wheel shear (W / C) that applies hydraulic pressure to brake wheels connected to wheels,
And a hydraulic pipe connecting M / C and W / C. In such a braking mechanism, when the vehicle operator depresses the brake pedal, hydraulic pressure is generated in M / C according to the depth of depression (generation of M / C pressure). The generated M / C pressure is transmitted to W / C through the hydraulic pipe and acts on the brake wheel (W / C pressure action). As a result, the vehicle is hydraulically braked.

When the vehicle to be braked is an electric vehicle, regenerative braking is further possible. That is, the vehicle can be braked by regenerating electric power from the vehicle traveling motor to the vehicle-mounted battery or the like. The regenerative braking force can be controlled by controlling a power conversion circuit provided between the battery and the motor.

In an electric vehicle, therefore, hydraulic braking and regenerative braking can be used together. At that time, it should be noted that the braking energy can be collected in the battery by the regenerative braking. That is, by preferentially using the regenerative braking over the hydraulic braking, it is possible to enjoy benefits such as efficient use of energy and extension of a travelable distance per charge of the battery. Further, since both the hydraulic braking force and the regenerative braking force can be controlled, the total braking force can be controlled so as to satisfy the required braking force (for example, the depth of depression of the brake pedal = M / C pressure). .

A control (braking force distribution control) concerning how to distribute the required braking force to the hydraulic braking force and the regenerative braking force to use the energy most efficiently (braking force distribution control) is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-161209. It can be realized by the disclosed device. In the device disclosed in this publication,
A linear solenoid valve is provided on the hydraulic pipe from M / C to W / C. This linear solenoid valve remains closed until the differential pressure before and after it (that is, the difference between the M / C pressure and the W / C pressure) reaches the valve opening pressure, and holds the differential pressure when the valve opening pressure is reached. While opening, apply hydraulic braking force.

When the linear solenoid valve is closed, the hydraulic braking force does not act. In this state, in order to realize the required braking force (depth of depression of the brake pedal = M / C pressure), the regenerative braking force according to the required braking force may be generated. Further, when the linear solenoid valve is open, only the hydraulic braking force corresponding to the value obtained by subtracting the valve opening pressure from the M / C pressure acts. In order to realize the required braking force in this state, the difference between the required braking force and the hydraulic braking force, that is, the regenerative braking force corresponding to the valve opening pressure of the linear solenoid valve may be generated. When such control is performed, only the regenerative braking force is used when the brake pedal is shallowly depressed, so that the braking energy is efficiently recovered as electric power in the battery, and the required braking force is more suitable for the regenerative braking force. realizable. When the brake pedal is deeply depressed, the regenerative braking force becomes a value (maximum value) equivalent to the valve opening pressure, and the braking energy can be efficiently recovered. At the same time, since the difference between the required braking force and the regenerative braking force is compensated for by the hydraulic braking force, the required braking force can be preferably realized. Since the valve opening pressure of the linear solenoid valve can be linearly controlled by driving the solenoid, the braking energy can be optimally recovered by controlling the valve opening pressure according to the state of charge (SOC) of the battery.

Further, the control of the valve opening pressure of the linear solenoid valve is also useful for coping with the ineffective regeneration. That is,
When the regenerative ability of the electric power to the battery etc. in the vehicle is reduced and the required regenerative torque cannot be obtained (regeneration is invalid), the valve opening pressure of the linear solenoid valve is lowered and the hydraulic pressure is changed from the M / C side to W If the hydraulic braking force is increased by introducing the braking force to the / C side, the required braking force can be appropriately realized despite the ineffective regeneration.

[0008]

However, in the above configuration, the differential pressure between the M / C pressure and the W / C pressure is maintained.
Therefore, when the hydraulic pressure (for example, hydraulic pressure) is introduced to the W / C side to obtain the required braking force at the time of regenerative invalidation, the regenerative ability is recovered thereafter, but the regenerative braking force is equivalent to the amount of regenerative ability recovery. If the braking force is increased (see FIG. 14), the total braking force of the hydraulic pressure and the regenerative force exceeds the required braking force by the amount of the regenerative braking force, and in some cases, the brake feeling changes significantly. It is possible to perform control so that the regenerative braking force is not increased even if the regenerative ability is restored.However, in this case, it is not possible to return to the control state before the regenerative expiry, despite the recovery of the regenerative ability, and therefore the braking energy recovery state It is maintained in an unnecessarily bad state.

The present invention has been made to solve the above-mentioned problems, and when the regenerative ability is restored after the regeneration has expired, the regenerative braking force is increased in consideration of the feeling to increase the liquid regenerative braking force. A first object is to improve the recovery state of braking energy while suppressing the difference between the total braking force of pressure and regeneration and the required braking force within a range in which the brake feeling does not change significantly.

Further, according to the present invention, when the regenerative ability is recovered after the regeneration is expired, the regenerative braking force is increased while the hydraulic braking force is reduced to control the total braking force of the hydraulic pressure and the regenerative braking force to the required braking force. A second object is to make it possible to optimize the braking energy recovery state.

Further, the present invention realizes this means by using a controllable valve such as a linear valve or an on-off valve, thereby simplifying and reducing the weight of the device.
The purpose of. A fourth object of the present invention is to further simplify and reduce the weight of the device configuration by utilizing this means for controlling the braking force distribution between the hydraulic braking force and the regenerative braking force and coping with the regenerative deactivation. And The present invention uses this means to prevent wheel lock by an anti-lock brake system (AB).
A fifth object is to further simplify and reduce the weight of the device by using it as a part of S). The present invention provides M / C with the introduction of hydraulic pressure at the time of reactivation.
A sixth object is to prevent bottoming such as.

[0012]

In order to achieve such an object, a braking control device for an electric vehicle according to a first configuration of the present invention uses a hydraulic pressure corresponding to a required braking force generated in M / C. Normal-time control in which a hydraulic braking force smaller than the required braking force is applied by limiting it to a predetermined hydraulic pressure and then transmitting it to W / C, while applying a regenerative braking force corresponding to the difference between the required braking force and the hydraulic braking force Means and regenerative revocation to increase hydraulic braking force by the amount equivalent to the revocation braking force when a situation occurs where the desired regenerative braking force cannot be obtained due to reactivation (including both partial revocation and total revocation) When the regenerative braking force reaches a state where it can be recovered from the ineffective state after the hydraulic braking force is controlled to be increased to a value equivalent to the required braking force by the control means and the regeneration ineffective control means, the predetermined upper limit value is set to the recovery amount. Regenerative braking force as a limit Characterized in that it comprises a regenerative recovery means for recovering.

In the braking control device according to the second structure of the present invention, instead of the regenerative recovery means in the first structure, after the regenerative invalidation control means, the hydraulic braking force is controlled to increase to a value corresponding to the required braking force. When the regenerative braking force can be recovered, a hydraulic pressure reduction regenerative recovery means is provided that reduces the hydraulic braking force according to the recovery amount of the regenerative braking force while recovering the regenerative braking force according to the recovery amount. It is characterized by being provided.

In the braking control device according to the third structure of the present invention, in addition to the second structure, the first controllable valve whose valve opening pressure can be controlled is a liquid from M / C to W / C. A second controllable valve provided on the pressure transmission path and capable of discharging the braking fluid from the W / C is provided, and the normal time control means controls the valve opening pressure of the first controllable valve to the predetermined fluid pressure. Therefore, the hydraulic pressure at M / C is cut off to the predetermined hydraulic pressure, and the regenerative invalidation time control means reduces the opening pressure of the first controllable valve to reduce the hydraulic braking force to the regenerative braking force. And a means for increasing the amount corresponding to the ineffectiveness of the regenerative braking force, and the fluid pressure reduction regenerative recovery means controls the second controllable valve to discharge the braking fluid from the W / C so that W / C is regenerated in accordance with the recovery amount of the regenerative braking force. It is characterized by having a means for reducing the liquid pressure at C.

The braking control device according to a fourth structure of the present invention is the braking control device according to the third structure, wherein the second controllable valve is capable of discharging W / C braking liquid to a predetermined reservoir. It is a valve provided so that the brake fluid in the reservoir can be introduced into the W / C, and when the regenerative invalidation control means has a situation in which the desired regenerative braking force cannot be obtained due to the invalidation, the M / C braking fluid is generated. Is introduced into the W / C, the means for determining whether or not the amount of the braking fluid in the M / C drops below a predetermined limit, and the M / C by the control of the first controllable valve when it is determined that the amount does not fall. A means for introducing a braking fluid from C to W / C to increase the hydraulic braking force by an amount corresponding to the invalidation of the regenerative braking force, and a controllable second controllable valve from the reservoir to W / C when it is determined that the hydraulic braking force is reduced. By introducing the braking fluid, the hydraulic braking force is increased by the amount corresponding to the expiration of the regenerative braking force. And having a means.

A braking control device according to a fifth configuration of the present invention is the braking control device according to the third to fourth configurations, wherein the first controllable valve and the second controllable valve are configured as a single valve. It is characterized by being done.

In the braking control system according to the sixth aspect of the present invention, in the third to fifth aspects, the second controllable valve is
It is one of the valves constituting the ABS for preventing the wheel lock.

[0018]

In the first configuration of the present invention, when the hydraulic braking force is controlled to be increased to the value corresponding to the required braking force by the regenerative invalidation control means, and then the regenerative braking force can recover from the invalidation, That is, when the regenerative ability is recovered, the regenerative recovery means recovers / increases the regenerative braking force with the predetermined upper limit value as the recovery amount limit. As a result, the amount of braking energy recovered increases as the regenerative capacity is restored. Also, with the recovery / increase of the regenerative braking force, the total braking force of the hydraulic pressure and the regenerative amount increases, and there is a difference between the required braking force up to that time, but the amount of recovery / increase of the regenerative braking force is limited. Therefore, the brake feeling does not change significantly. Therefore, in the first configuration, the recovery state of the braking energy is improved without a significant change in the brake feeling.

In the second configuration of the present invention, when the regenerative ability is recovered after the hydraulic braking force is controlled to be increased to the value corresponding to the required braking force by the regenerative invalidation control means, the hydraulic pressure reduction regenerative recovery means is provided. The hydraulic braking force is reduced according to the recovery amount of the regenerative braking force, while the regenerative braking force is recovered according to the recovery amount. As a result, the amount of braking energy recovered increases as the regenerative capacity is restored. In addition, since the total braking force of the hydraulic pressure and the regeneration is the same value as the total braking force up to that time, in the second configuration, the braking energy is controlled while controlling the total braking force of the hydraulic pressure and the regeneration to the required braking force. The second object of the present invention of optimizing the recovery state of is preferably achieved.

In the third configuration of the present invention, the braking force distribution control before regenerative invalidation and the control for dealing with the regenerative invalidation are provided on the hydraulic pressure transmission path from M / C to W / C. It is realized as the control of the first controllable valve capable of controlling the valve opening pressure. That is, the braking force distribution control before regeneration invalidation, in particular, the cutoff of the hydraulic pressure is realized by controlling the valve opening pressure of the controllable valve to the above-mentioned predetermined hydraulic pressure by the normal time control means, and the hydraulic braking force at the time of regeneration invalidation. The control for increasing the regenerative braking force by the amount corresponding to the invalidation is realized by reducing the valve opening pressure of the controllable valve by the regenerative invalidation control means. Further, in this configuration, the hydraulic pressure reduction control at the time of regenerative recovery is controlled from M / C to W /
It is realized as control of a second controllable valve that is provided on the hydraulic pressure transmission path to C and is capable of discharging the braking fluid from W / C. That is, when reducing the hydraulic pressure at W / C according to the amount of recovery of the regenerative braking force, the hydraulic pressure reduction regenerative recovery means controls the second controllable valve to discharge the braking liquid from W / C.
As a result, the means for reducing the hydraulic braking force when the regenerative ability is restored after the regenerative invalidation is realized suitably and simply as the second controllable valve and its control. Moreover, since the second controllable valve can be realized by using a linear valve or the like, the device configuration is simplified and lightened.

When the third configuration is realized, as in the fourth configuration, the W / C braking fluid is used as the second controllable valve in the M / C.
When a valve that can discharge the brake fluid from the reservoir to the W / C is provided and the valve is used to introduce the hydraulic pressure to the W / C side when the regeneration expires, M / C
It is possible to prevent bottoming. For example, in the fourth configuration of the present invention, the regenerative invalidation time control means is
If the braking fluid of M / C is introduced into W / C at the time of reactivation, M
It is determined whether or not the amount of the braking fluid (for example, an incompressible fluid such as oil) in / C falls below a predetermined limit (whether there is a risk of bottoming or insufficient braking fluid). When it is determined that the pressure does not decrease, the braking fluid is introduced from the M / C to W / C by the control of the first controllable valve, and when it is determined that it decreases, the W / C by the reservoir is controlled by the control of the second controllable valve. The braking fluid is introduced into. As a result, the hydraulic braking force increases by an amount corresponding to the invalidation of the regenerative braking force while avoiding the risk of bottoming the M / C.

In the fifth configuration, the first controllable valve and the second controllable valve are configured as a single valve. Therefore, the braking force distribution control, the hydraulic pressure increase control at the time of the regeneration invalidation, and the hydraulic pressure reduction control at the time of the regeneration recovery are realized by using a single valve. This further simplifies and reduces the weight of the device.

In the sixth structure, the second controllable valve is one of the control valves constituting the ABS device. Therefore, the device configuration is further simplified and made lighter by integrating the device functions.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the system configuration of an electric vehicle according to the first embodiment of the present invention. The system shown in this figure uses a three-phase AC motor as the traveling motor 10 and uses both hydraulic braking and regenerative braking as braking means.

The output shaft of the motor 10 is connected to a front wheel (not shown) via a reduction gear (R / G) 12 and a drive shaft 14. That is, when the motor 10 is rotationally driven, its output is decelerated by the R / G 12 and then transmitted to the drive shaft 14 to rotate the front wheels.

The drive power of the motor 10 is the inverter 16
It is supplied from the battery 18 via the. Since the power discharged from the battery 18 is DC power, power conversion from DC to AC is necessary to drive the AC motor 10, and the inverter 16 performs this power conversion. The inverter 16 is composed of a predetermined number of switching elements, and the drive current of the motor 10 can be vector-controlled by switching each switching element using a PWM (pulse width modulation) signal generated according to the torque command. . By this control, the output torque of the motor 10 is
It can be controlled to the torque command value.

The EVECU 20 controls the output torque of the motor 10 using PWM. Motor 10
When attempting to power the vehicle to accelerate the vehicle, the vehicle operator depresses an accelerator pedal (not shown). EV ECU
20 inputs a signal indicating the shift position while inputting a signal indicating the depth of depression of the accelerator pedal. When the motor 10 is powered, a torque command is issued according to the depth of depression of the accelerator pedal. To generate. Motor 1
Since the output torque of 0 depends on the rotation speed, EVEC
U20 operates the motor 10 before generating the torque command.
The number of rotations is calculated and the obtained number of rotations is used to generate the torque command. The rotation speed of the motor 10 is obtained by calculation based on the position of the rotor detected by the rotation position sensor 22 attached to the motor 10. EVECU 20 is a battery EC
State of charge of battery 18 detected and calculated by U24 (S
OC), voltage V _B, etc., and components detected by the outputs of various temperature sensors (not shown) (motor 1
0, the inverter 16 and the like), after adjusting the torque command based on the information such as the temperature of the motor 1 and the motor 1 based on this torque command.
A current command for each phase of 0 is generated, and a PWM signal is generated based on this current command to control the switching operation of the inverter 16. In this way, the output torque of the motor 10 at the time of acceleration becomes a value according to the depth of depression of the accelerator pedal.

Of the braking means, the hydraulic braking mechanism has a master cylinder (M / C) 28 for generating hydraulic pressure according to the depth of depression of the brake pedal 26. M / C28
The hydraulic chamber related to the front wheel among the plurality of hydraulic chambers constituting the wheel cylinder (W / C) on the front wheel side via the hydraulic pipe 30.
It communicates with 32. A linear valve 34 and a check valve 36 are provided in parallel with each other on the hydraulic pipe 30, and P & B (proportioning & bypass) is further provided.
A valve 38 is provided. In particular, the linear valve 34
Is a differential pressure valve that generates a differential pressure between the M / C 28 and the W / C 32 and has a solenoid, and its valve opening pressure can be linearly changed according to a drive signal. Therefore, even if a hydraulic pressure is generated in the M / C 28, no hydraulic pressure is generated in the W / C 32 until the hydraulic pressure (M / C pressure) exceeds the valve opening pressure of the linear valve 34, and the drive shaft 1
The hydraulic pressure does not act on the brake wheel 40 provided on the vehicle 4 and provided with the W / C 32. Also, M
When the / C pressure exceeds the opening pressure of the linear valve 34, the check valve 36 holds the differential pressure before and after the linear valve 34, so that the hydraulic pressure generated in the W / C 32 and acting on the brake wheel 40 (the W / C pressure). ) Is the oil pressure obtained by subtracting the valve opening pressure of the linear valve 34 from the M / C pressure. Further, when the valve opening pressure of the linear valve 34 is controlled to 0, the M / C pressure acts as it is on the brake wheel 40 as the W / C pressure.

Among the plurality of hydraulic chambers constituting the M / C 28, the hydraulic chamber related to the rear wheel is the W on the rear wheel side via the hydraulic pipe 42.
/ Communication with C44. On the hydraulic pipe 42, the differential pressure valve 4
6, a P valve 48 and a bypass valve 50 are provided in parallel with each other, and a P & B valve 38 is further provided. The differential pressure valve 46 generates a differential pressure between the M / C 28 and the W / C 44. The bypass valve 50 has a solenoid, and bypasses the differential pressure valve 46 according to the supply of the drive signal. The W / C pressure generated in the W / C 44 acts on the brake wheel 52 that is connected to the rear wheels and has the W / C 44 attached thereto. In the figure, 54 is an M / C 28 reservoir.

The control for realizing the regenerative braking of the braking means is executed by the regenerative ECU 56 and the EVECU 20. The regenerative ECU 56 and the EV ECU 20 detect that the brake pedal 26 is stepped on by the brake switch 58 attached to the brake pedal 26, and start the control related to the regenerative braking. In this control, the regenerative ECU 56 detects the M / C pressure using the hydraulic sensor 60 attached to the M / C 28 side of the hydraulic pipe 30 or 42. The M / C pressure is the depth of depression of the brake pedal 26,
That is, it shows the braking force required by the vehicle operator. Regeneration ECU56 is how much power can be regenerated to the battery 18 from the motor 10 on the basis of the SOC, _{V B} such information to be detected and calculated by cell ECU 24, that is, battery 18
Knowing the regenerative capacity of, and driving the solenoid of the linear valve 34 accordingly to set the valve opening pressure to a value equivalent to the regenerative capacity.
Control. Further, the regenerative ECU 56 is configured to detect the detected M / C.
The difference between the braking torque corresponding to the pressure (request braking torque) and the braking torque corresponding to the valve opening pressure of the linear valve 34 is calculated,
The obtained difference is used as the regenerative torque command T _BRK and the EVECU2
Output to 0. However, depending on the SOC of the battery 18 or the like, the regenerative ECU 56 adjusts the value of the regenerative torque command T _BRK prior to the output to the EVECU 20. EVEC
U20 is a regenerative torque of the regenerative torque command _{T BRK} same value given from the regenerative ECU56 is as obtained from the motor 10, controls the inverter 16 in a manner similar power running. EVECU20 monitors the operation of the inverter 16, the inverter 16 performs the subtraction correction corresponding to the temperature rise such as a motor 10 in a regenerative torque command _{T B RK,} regenerating the value of the regenerative torque that can be actually output as a return value _{T RE} Return to ECU 56. Prior to the next output of the regenerative torque command T _BRK , the regenerative ECU 56 compares the previous regenerative torque command T _BRK with the corresponding return value T _RE , and according to the result, the characteristics of the present embodiment are related. Perform a predetermined operation.

FIG. 2 shows a regenerative ECU in this embodiment.
A flow of 56 operations is shown. In this embodiment, the regenerative ECU 56 first initializes various variables and flags used in the processing (100). After performing the initialization, the regenerative ECU 56 executes an initial check regarding whether or not regenerative braking may be used (10
2). Until the initial check is established, regenerative EC
U56 opens the linear valve 34 and the bypass valve 50, and controls the M / C pressure to be the W / C pressure as it is. After the initial check is established, the regenerative ECU 56
Calculates the rotational speed of the motor 10 based on the output of the rotational position sensor 22 (104), determines whether the shift position is an abnormal position based on the shift signal (106), and then determines the brake switch. The state of 58 is determined (108). When the state of the brake switch 58 indicates that the brake pedal 26 is stepped on, the regenerative ECU 56 executes step 114. Regeneration ECU56 calculates a regenerative torque command _{T BRK} based on the difference M / C pressure and the W / C pressure in step 114, the value of the regenerative torque command _{T BRK} based on the temperature of the battery 18 continues at step 116 adjust. For example, according to the temperature rise of the battery 18, the regenerative torque command T
_{Reduce BRK} . Regeneration E in step 118
The CU 56 drives the solenoid of the linear valve 34 to control the valve opening pressure to a value equivalent to the regenerative ability. In step 120, an abnormality in each part of the apparatus is inspected and a corresponding process is performed, and the process returns to step 102. The operation of driving these solenoids and the operation of fail processing are executed by a drive circuit and the like incorporated in the regenerative ECU 56 by appropriately setting flags.

The operations featured by this embodiment are steps 110 and 112. In step 110,
The regenerative ECU 56 outputs the regenerative torque command T output to the EVECU 20 when executing steps 114 and 116 the last time.
_BRK and a return value T notified from the EVECU 20 as a result of control based on the regenerative torque command T _BRK.
Compare with _RE . As a result of the comparison, if the two match, the requested regenerative torque (regenerative torque command T _BRK ) can be realized, and it can be considered that regenerative ineffectiveness has not occurred, so the operation of the regenerative ECU 56 immediately proceeds to step 114. Move to. If they do not match, the regenerative ECU 56 considers that the regenerative torque command T _BRK cannot be realized, that is, the regeneration is partially or completely ineffective, and executes the hydraulic pressure introducing process in step 112. , Step 118 and subsequent steps are executed.

FIG. 3 shows step 1 in this embodiment.
Twelve contents are shown. In this embodiment, the regenerative ECU 56 first subtracts the corresponding return value T _RE from the previous regenerative torque command T _BRK and the value ΔT.
_PRS is obtained, and the valve opening value of the linear valve 34 is set to this value ΔT.
_{The PRS} equivalent amount is reduced (200). Accordingly, the torque (hydraulic torque) T _PRS related to hydraulic braking is ΔT
Increase by _PRS (introduction of hydraulic pressure). The hydraulic pressure newly introduced to the W / C 32 in step 200 (ΔT _PRS
(Equivalent) remains until the vehicle operator releases the brake pedal 26 and the M / C pressure is reduced accordingly. By this processing, the return value T _RE is lowered due to the revocation of regeneration, and thus the total braking torque T _total = T _RE + T.
The decrease in _PRS can be compensated for, and the required braking force (required braking torque) can be suitably realized despite the ineffective regeneration.

The greatest feature of this embodiment is the processing when the regenerative power is restored after the regenerative power has been invalidated and the hydraulic pressure is introduced in step 200. The operation after step 202 in FIG. 3 indicates this processing.

After executing step 200, the regenerative ECU 56 determines whether or not the regenerative ability is restored during one brake based on the increase amount ΔT _RE of the return value T _RE (2
02). The term "one brake" as used herein means a period from when the vehicle operator starts to depress the brake pedal 26 until when the vehicle pedal is completely returned. If the regenerative ability has not recovered, the regenerative ECU 56
The operation returns to the operation of FIG. When it is determined that the regenerative ability has recovered, the regenerative ECU 56 executes step 204 and subsequent steps.

The regenerative ECU 56 holds the hydraulic torque increase amount ΔT _{P RS} introduced in step 200 (204), and according to the regenerative torque recovery amount ΔT _RE obtained as the increase amount of the return value T _RE , the regenerative torque command. T
The increase amount of _BRK is set (206, 208). When performing step 114 later, step 206 or 208
The regenerative torque command T is increased by the increase amount set in
_BRK will be increased compared to the previous time. Before executing step 206 or 208, the regenerative ECU 56 compares the regenerative ability recovery amount ΔT _RE with the regenerative recovery limit value ΔT (210). As a result of this comparison, if it is determined that ΔT _RE <ΔT, it can be considered that the increase amount remains smaller than the regenerative recovery limit value ΔT even if the regenerative torque command T _BRK is increased by the regenerative ability recovery amount ΔT _RE. , Regeneration E
The CU 56 increases the regenerative torque command T _BRK by the regenerative capacity recovery amount ΔT _RE (206). Conversely, ΔT _RE
When it is determined that ≧ ΔT, if the regenerative torque command T _BRK is increased by the regenerative ability recovery amount ΔT _RE, it can be considered that the increase amount is equal to or greater than the regenerative recovery limit value ΔT, so the regenerative ECU.
56 limits the amount of increase of the regenerative torque command T _BRK to the regenerative recovery limit value ΔT (208). After this, step 11
Go to 4.

FIG. 4 shows an example of changes in the braking torque in this embodiment. As shown in this figure, at time t = 0, the vehicle operator operates the brake pedal 2
Suppose you start stepping on 6. At time t = t ₁ , the regeneration is invalidated, and when the difference between the regenerative torque command T _BRK and the return value T _RE begins to occur, the regenerative ECU 56 introduces the hydraulic pressure corresponding to ΔT _PRS (200). Then, the hydraulic torque T
_PRS is increased by ΔT _PRS , which compensates for the difference between the regenerative torque command T _BRK and the return value T _RE . When the brake pedal 26 reaches its maximum at time t = t ₂ and then the regenerative ability starts to recover at time t = t ₃ before the vehicle operator finishes releasing the brake pedal 26 again, the regenerative ECU 56 causes the step 206-21
The regenerative torque command T _BRK is increased by setting the regenerative recovery limit value ΔT to the upper limit by 0 (time t = t ₄ ). Along with this, the return value T _RE also increases with the regenerative recovery limit value ΔT as the upper limit, and the total braking torque T _total also increases.

As described above, according to this embodiment, the regenerative torque command T is reached when the regenerative ability is restored in one brake.
_{Since the BRK} is increased, the braking energy is appropriately recovered by regeneration, and an electric vehicle having a long travelable distance per charge of the battery 18 can be obtained. Further, since the amount of increase at that time is limited by the regenerative recovery limit value ΔT, the brake feeling does not significantly deteriorate with the recovery of the regenerative ability. Note that the regeneration recovery limit value ΔT is the motor 1
Based on the number of revolutions and the vehicle speed of 0, or based on the deceleration of the vehicle obtained from any of these, it may be determined to be x (%) of the deceleration as shown in FIG. 5A, for example. Further, x is set to a value proportional to the vehicle speed or the deceleration as shown in FIG. 5B, for example. If determined in this way, the total braking torque T _total accompanying the recovery of the regenerative ability
Can be suppressed within a range that does not lead to significant deceleration. Also, the total braking torque T at the time of recovery from the invalidation
Conversely, an increase in _total means an improvement in braking effectiveness.

FIG. 6 shows the system configuration of an electric vehicle according to the second embodiment of the present invention. In this embodiment, a hydraulic system related to the antilock brake system (ABS) 62 is provided between the P & B valve 38 and the W / Cs 32 and 44, and A is used as its control means.
BSECU 64 is provided. The regenerative ECU 56
In addition to the original operation of the ABS 62 for preventing wheel lock, also in the W / C pressure reduction control according to the features of this embodiment,
Communicate with ABS ECU 64. A drain valve 66 is attached to the ABS 62. The drain valve 66 has a drain port 66a.
6a is the reservoir 5 of the M / C 28 via the drain pipe 68.
It communicates with 4. Replace the drain port 66a with the reservoir 54
Since the capacity of the internal reservoirs 72 and 74 of the ABS 62 is normally set to about 2 to 3 cc to ensure responsiveness, and is set for each vehicle type, the amount of oil for recovery from regenerative revocation is Because it is difficult to absorb. The drain valve 66 has a solenoid, and the regenerative ECU 5
Reference numeral 6 supplies a drive current to this solenoid to control its operation.

The ABS 62 has an internal reservoir 72 corresponding to the front wheels and an internal reservoir 74 corresponding to the rear wheels. The oil stored in the internal reservoirs 72 and 74 can be pumped by a pump 78 or 80 driven by a motor 76. On the other hand, between the P & B valve 38 and the W / C 32 on the right side of the drawing, a solenoid valve 82 and a check valve 84 are provided.
And the solenoid valve 86 between W / C32 on the left side of the figure.
And the check valve 88 is a P / B valve 38 and W / C.
A solenoid valve 90 and a check valve 91 are arranged between 44. Solenoid valve 8
Solenoid valves 92, 94 and 96 are arranged between 2, 86 and 90 and the internal reservoir 72 or 74. The pumps 78 and 80 described above include the M / C ports 82a, 86a or 90a of the solenoid valves 82, 86 or 90 and the W / C of the solenoid valves 92, 94 or 96.
It is arranged between the C port 92a, 94a, and 96a. Each member constituting the ABS 62 has an ABS ECU 6
4 controls or drives.

FIG. 7 shows a regenerative ECU in this embodiment.
A flow of 56 operations is shown. The flow of this figure is the first
The difference from the embodiment is that the control of the ABS 62 is executed corresponding to the provision of the ABS 62 (12
2) and the contents of step 112.

In this embodiment, the regenerative ECU 56
Executes the control of the ABS 62 in response to the provision of the ABS 62, and also executes step 1 of the contents different from the first embodiment.
Execute 12.

First, in controlling the ABS 62, the regenerative ECU 56 gives a command to the ABS ECU 64 to execute P & B.
The ABS 62 is controlled so that the W / C ports 38a and 38b of the valve 38 communicate with the W / Cs 32 and 44 as they are. That is, the solenoid valves 82, 86 and 90
Open while closing solenoid valves 92, 94 and 96. The ABS ECU 64 controls the solenoid valves 82, 86, 90, 92, 94 and 96 and operates the pumps 78 and 80 to operate the internal reservoir 72 when the predetermined conditions are satisfied and it can be considered that the wheels are likely to be locked. While using the oil amounts of 74 and 74, the W / C pressure is increased or decreased in a predetermined pattern. Thereby, the wheel lock is preferably prevented. The drain valve 66 is kept closed in this state.

FIG. 7 shows step 1 in this embodiment.
Twelve contents are shown. In this embodiment, the regenerative ECU 56 first determines whether the reduction (ineffectiveness) of the regenerative ability that has occurred this time is the first reduction in one brake or the second or subsequent reduction (212). When it is determined that the pressure has dropped for the first time, the regenerative ECU 56 determines that the linear valve 34 has
By decreasing the valve opening pressure of ΔT _PRS = T _BRK −T
A hydraulic pressure equivalent to _RE is introduced from the M / C 28 to the W / C 32 (214). On the contrary, when it is determined that the decrease has occurred after the second time, the regenerative ECU 56 opens the drain valve 66 while holding the linear valve 34, rotates the motor 76, and causes the pump 78 to drive the ΔT _PRS from the reservoir 54 of the M / C 28.
A corresponding hydraulic pressure is introduced into the W / C 32 (216). The reason why the hydraulic pressure is introduced from the M / C 28 at the first decrease is to avoid the occurrence of a time delay when the hydraulic pressure is introduced from the reservoir 54 because the reservoir 54 is open to the atmosphere. Reservoir 5 if it is the second and subsequent drops
The reason for using the oil in No. 4 is to avoid the bottom of the oil of M / C 28 (bottoming) and the shortage of braking oil. After execution of step 214 or 216, regenerative EC
U56 moves to step 118 through step 202 and the like. By executing these steps 214 or 216,
The hydraulic torque increases and the regenerative invalidation is compensated.

When the regenerative ability is restored during one brake (202), the regenerative ECU 56 reduces the W / C pressure of the W / C 32 by a regenerative ability recovery amount ΔT _RE (21).
8). That is, the solenoid valves 84 and 86 of the ABS 62 are closed, and the solenoid valves 92 and 94 are closed.
By opening the (pressure reducing valve) to connect the W / C 32 to the drain oil passage 66b, and further opening the drain valve 66, W
Release the W / C pressure of / C32. As a result, the hydraulic torque is reduced by ΔT _RE . At the same time, the regenerative ECU 56 increases the amount of increase of the regenerative torque command T _{BRK by} the amount of recovery ΔT of the regenerative ability.
Set to _RE (220). When the increased amount is added to the previous regenerative torque command T _BRK in step 114 and output after adjustment (116), the regenerative torque command T _BRK is realized because the regenerative ability is restored. The resulting total regenerative / hydraulic braking torque T _total
Is the same as the previous value. Note that steps 218 and 2
20 is executed at substantially the same timing.

FIG. 9 shows an example of changes in the braking torque in this embodiment. As shown in this figure, at time t = 0, the vehicle operator operates the brake pedal 2
Suppose you start stepping on 6. At time t = t ₁ , the regeneration is invalidated, and when the difference between the regenerative torque command T _BRK and the return value T _RE starts to occur, the regenerative ECU 56 introduces the hydraulic pressure corresponding to ΔT _PRS (214, 216). Then, the hydraulic torque T _PRS increases by ΔT _{P RS} , which compensates for the difference between the regenerative torque command T _BRK and the return value T _RE . At time t = t ₂ , the depression of the brake pedal 26 reaches the maximum, and then the vehicle operator operates the brake pedal 26.
The regenerative capacity starts to recover in previous end returned to the depression of the time t = _{t 3,} the regeneration ECU56, the step 21
8 and 220, the regenerative torque command T _BRK is increased by the regenerative capacity recovery amount ΔT _RE and the W / C32 W
/ C pressure is reduced by ΔT _RE (time t = t ₄ ). Along with this, the return value T _RE also increases by ΔT _RE , and the total braking torque T _total is maintained at the previous value.

Therefore, according to the present embodiment, since the W / C pressure of the W / C 32 can be reduced when the regenerative ability is recovered, the regenerative operation can be recovered well without changing the total braking torque T _total. It is possible to realize various energy recovery states. Moreover, since the pressure reducing valve of the ABS 62 is used as a means for reducing the W / C pressure of the W / C 32, a large-scale addition to the device configuration does not occur. In this way, the above effects can be realized with a relatively small and lightweight device configuration. 1
The introduction source of the hydraulic pressure is changed depending on whether the regenerative ability starts to decrease during braking and the second and subsequent times. However, the number of times and after which the hydraulic pressure is introduced from the reservoir 54 can be arbitrarily set. That is, it is sufficient to avoid bottoming of the M / C 28 and shortage of braking oil.

FIG. 9 shows the system configuration of an electric vehicle according to the third embodiment of the present invention. In this embodiment, the valves inside the ABS 62 are linear valves 304, 3
Configured as 06 and 308. Further, the linear valve 34, the differential pressure valve 46, etc. are not used.

That is, the ABS 62 in this embodiment.
Has internal reservoirs 72 and 74, motor 76 and pumps 78 and 80, as well as linear valves 304, 306 and 308. Each of the linear valves 304, 306 and 308 has a solenoid as will be described later in detail, and the valve opening pressure and the internal communication state can be controlled by driving the solenoid. Linear valves 304 and 3
06 M / C ports 304a and 306b are connected to the M / C 28 via solenoid valve 310 and P & B valve 38.
Is connected to the M / C port 3 of the linear valve 308.
08a is a solenoid valve 312 and a P & B valve 38
Through the M / C 28. Linear valve 30
The W / C ports 304b and 306b of 4 and 306 communicate with the W / C 32 on the front wheel side, and the linear valve 308
W / C port 308b communicates with W / C 44 on the rear wheel side. Further, the drain ports 304c and 306c of the linear valves 304 and 306 are connected to the internal reservoir 72,
The drain ports 308c of the linear valves 308 communicate with the internal reservoirs 74, respectively.

FIG. 10 shows the regenerative EC in this embodiment.
The flow of operation of U56 is shown. The flow of the entire operation of the regenerative ECU 56 in this embodiment is the same as in the second embodiment. FIG. 10 shows the contents of step 112.

In this embodiment, the regenerative ECU 56
Normally opens the solenoid valves 310 and 312 while commanding the ABS ECU 64 to cause the M / C ports 304a, 3a of the linear valves 304, 306 and 308 to move.
06a and 308a and W / C ports 304b and 306b
And 308b communicate internally. If the possibility of wheel locks arises, the ABS ECU 62 will activate the internal reservoir 7
W / C 32 and 44 W / using oil amount of 2 and 74
The C pressure is increased or decreased in a predetermined pattern.

In step 110, the regenerative torque command T
_When it is determined that _BRK is not equal to the return value T _RE , the regenerative ECU 56 first determines whether or not the regeneration is invalid for the first time in one brake (212). If it is the first time, the regenerative ECU 56 closes the solenoid valve 310 and also causes the M / C ports 304a and 306b and the W / C ports 304b and 30 of the linear valves 304 and 306 to be closed.
6b is made to communicate internally, the motor 76 is further rotated, and the hydraulic pressure is introduced from the internal reservoir 72 to the W / C 32 by the pump 78 (226). In the case of the second and subsequent times, the regenerative ECU 56 opens the solenoid valve 310 and internally connects the M / C ports 304a and 306a of the linear valves 304 and 306 with the W / C ports 304b and 306b so that the M / C 28 Hydraulic pressure is introduced into the W / C 32 (214). The hydraulic pressure newly introduced in steps 226 and 214 is a hydraulic pressure equivalent to ΔT _PRS = T _BRK −T _{RE when} expressed by the increase amount of the hydraulic torque T _PRS .
When the regenerative ability is restored during one brake (202), the regenerative ECU 56 closes the solenoid valve 310 and internally connects the W / C ports and the drain ports of the linear valves 304 and 306, so that the oil of the W / C 32 is removed. The internal reservoir 72 is drained to reduce the W / C pressure (22
8). The amount of reduction in W / C pressure is the amount of recovery of the regenerative ability ΔT _RE
It is considerable. At the same time, the regenerative ECU 56 sets the increase amount of the regenerative torque command T _BRK to ΔT _RE (220).

Therefore, according to this embodiment, the same effect as that of the above-mentioned second embodiment can be obtained. Furthermore, ABS
Since the valve forming 62 and the valve relating to the differential pressure generation are shared, the device configuration is further integrated, and the device becomes smaller and lighter. The determination in step 212 is not limited to the determination whether it is the first time. That is, the number of times of determination may be set so as to avoid bottoming of the internal reservoir 72.

In each of the above embodiments, a front-wheel drive vehicle is assumed, but the present invention can be applied to both a rear-wheel drive vehicle and a four-wheel drive vehicle. Further, the linear valve used in the description of each embodiment can be replaced with an on / off valve whose duty can be controlled. Further, the linear valve 34, the differential pressure valve 46, etc. in the first or second embodiment can be replaced by the valve used as the linear valve 304, 306 or 308 in the third embodiment. In that case, the drain port communicates with the reservoir 54 of the M / C 28 or the internal reservoir 72 or 74 of the ABS 62. The drain valve 66 is unnecessary.

11 to 13 show actual configurations of valves suitable for use as the linear valves 304 to 308 in the above embodiments. In particular, FIG. 11 is a vertical cross-sectional view showing the entire structure, and FIGS. 12 and 13 are partially enlarged vertical cross-sectional views showing the typical state thereof. The linear valve shown in these figures is constructed as a spool valve driven by a solenoid.

First, the solenoid coil 400 is shown on the right side in FIG. The solenoid coil 400 is wound around the core 404 while being housed in the case 402, and the terminal 4 is provided at one corner of the case 402.
A pair of ends of the solenoid coil 400 is electrically drawn to the outside via 06. Regenerative ECU 56 (3rd ~
When the fifth embodiment) or ABS ECU 64 (sixth embodiment) drives the linear valve, a drive current is supplied to the solenoid coil 400 via the terminal 406. Further, the opening of the case 402 is covered by the cover 40.
Covered by 8.

The core 404, the plunger 410 and the yoke 412 are all made of a magnetic material and are arranged around the shaft 418. The core 404 holds the right end of the shaft 414 and the yoke 412,
The plunger 410 is fixed to the shaft 414.
Therefore, when a driving current flows through the solenoid coil 400 to generate a magnetic field, the plunger 410 slides integrally with the shaft 418 in the extension direction of the shaft 418. On the other hand, since a minute gap is provided between the yoke 412 and the shaft 418, even when the plunger 410 slides to the left in FIG. 11, the plunger 410 contacts the right end in FIG. 11 of the yoke 412. Until it contacts the yoke 41
2 does not limit the sliding of the plunger 410. The plunger 410 is provided with a vent hole 420 so that the plunger 410 can slide in the space between the core 404 and the yoke 412 without receiving air resistance.

The core 404 is fixed to the valve body 422. The left end of the yoke 412 in the figure is fitted into a chamber 424 provided at the right end of the valve body 422. One end of the shaft 418 projects from the end of the yoke 412, and a push rod 426 extends from the projection. The push rod 426 penetrates the valve body 422 and is connected to the holder 430 in the chamber 428. Therefore, when the plunger 410 slides to the left in the drawing, the push rod 426 pushes the holder 430 to the left in the drawing, pushing the plate 431 to the cylinder 432 side. The cylinder 432 is a tubular member fitted in the valve body 422, and the left end thereof in FIG. 11 is fixed by bolts. Further, a return spring 434 is arranged between the holder 430 and the cylinder 432, whereby a biasing force to the right side in the drawing acts on the holder 430, and thus the plunger 410.

A spool 436 is arranged inside the holder 430 and the cylinder 432, and a diffuser 438 is arranged inside the spool 436. Spool 43
Reference numeral 6 is a cylindrical member, and a groove 440 is formed on the outer surface thereof so as to surround the circumference. A groove 442 is also formed along the circumference on the inner surface of the cylinder 432. Disc 4
22 and holder 430 have M / C port 444 and groove 4 when spool 436 reaches the position shown in FIG.
Flow paths 446 and 448 are formed so as to communicate the 40. Further, the groove 442 is formed so as to communicate with the groove 440 when the spool 436 reaches the position shown in FIG. The spool 436 further includes a groove 442 when the spool 436 reaches the position shown in FIG.
The flow path 450 is formed so as to communicate with the. On the other hand, the diffuser 438 is a hollow cylindrical member, and the flow path 452 is formed in the right half of the outer surface thereof. In addition, a slit 454 is formed in the left half thereof so as to communicate with the flow channel 452.
Is provided. The hollow portion of the diffuser 438 communicates with the W / C port 460 via a flow passage 456 inside the holder 430 and a flow passage 458 inside the valve body 422. The member indicated by 462 in the drawing is a spring for aligning the spool 436.

The cylinder 432 is further provided with a flow path 466 communicating with the drain port 464. This flow path 466 is W / C through the inside of the diffuser 438 when the spool 436 is in the position shown in FIG.
It communicates with the port 460 and is blocked when in the position shown in FIG. Further, the flow path 466 is formed in the chamber 4
It communicates with 24.

The position of the plunger 410 and thus the position of the spool 436 can be controlled by the value of the drive current supplied to the solenoid coil 400. Therefore, set M / C pressure to W
/ C32, the drive current value may be set so as to have the positional relationship shown in FIG. 12, and when the W / C pressure is drained, the drive current value may have the positional relationship shown in FIG. Should be set.

The present invention is not limited to such a valve structure.

[0064]

As described above, according to the first configuration of the present invention, when the regenerative ability is restored after the regenerative ineffectiveness,
Recovers the regenerative braking force with the specified upper limit value as the recovery amount limit.
Since the amount of braking energy is increased, the amount of braking energy recovered can be increased according to the recovery of the regenerative ability without a significant change in brake feeling. As a result, an electric vehicle with higher energy efficiency can be realized. Further, since the braking force increases within the above-mentioned limit at the time of regeneration recovery, the braking ability also improves.

According to the second configuration of the present invention, when the regenerative ability is recovered after the regenerative ineffectiveness, the hydraulic braking force is reduced according to the recovery amount of the regenerative braking force while the regenerative braking force is reduced to the recovery amount. Since the total braking force of the hydraulic pressure and the regeneration is controlled to the required braking force, that is, the amount of braking energy recovered according to the restoration of the regeneration capability without changing the brake feeling. Can be increased.

According to the third structure of the present invention, the braking force distribution control before regenerative revocation and the control relating to the regenerative revocation are
The controllable first valve provided on the hydraulic pressure transmission path from M / C to W / C and capable of controlling the valve opening pressure thereof is realized, and the hydraulic pressure reduction control at the time of regeneration recovery is performed by W Since it is realized as the control of the second controllable valve that can discharge the braking fluid from / C, it is possible to realize the control of the braking force distribution, the countermeasure at the time of regeneration invalidation, and the countermeasure at the time of regeneration recovery by using the valve. The device structure can be simplified and the weight can be reduced. According to the fourth configuration of the present invention, the valve capable of discharging the brake fluid of W / C to the reservoir such as M / C and introducing the brake fluid of the reservoir to W / C is the second controllable valve. As a result, the source of the hydraulic pressure is switched when the possibility of bottoming of M / C and the lack of braking fluid is judged at the time of regenerative invalidation, so that the hydraulic pressure is introduced to the W / C side at the time of regenerative invalidation. It is possible to prevent bottoming of M / C.

According to the fifth aspect of the present invention, since the first controllable valve and the second controllable valve are configured as a single valve, the braking force distribution control and the hydraulic pressure increase control at the time of regeneration invalidation are performed. The hydraulic pressure reduction control at the time of regenerative recovery can be realized by using a single valve, and the device configuration can be further simplified and lightened.

According to the sixth aspect of the present invention, since the second controllable valve is provided as one of the valves constituting the ABS,
By integrating the device functions, the device configuration can be further simplified and reduced in weight.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of an electric vehicle according to a first embodiment of the present invention.

FIG. 2 is a regenerative ECU in an embodiment not equipped with ABS.
3 is a flowchart showing the flow of the overall operation of FIG.

FIG. 3 is a flowchart showing a flow of a hydraulic pressure introducing operation of the regenerative ECU in the first embodiment.

FIG. 4 is a timing chart showing an example of changes in braking force distribution in the first embodiment.

FIG. 5 is a diagram for explaining a limit value of a regenerative recovery amount.

FIG. 6 is a block diagram showing a system configuration of an electric vehicle according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a flow of a hydraulic pressure introducing operation of a regenerative ECU in the second embodiment.

FIG. 8 is a timing chart showing an example of a change in braking force distribution in the second or third embodiment.

FIG. 9 is a block diagram showing a system configuration of an electric vehicle according to a third embodiment of the present invention.

FIG. 10 is a flowchart showing a flow of a hydraulic pressure introducing operation of a regenerative ECU in the third embodiment.

FIG. 11 is an overall vertical sectional view showing an example configuration of a linear valve.

FIG. 12 is a partially enlarged vertical cross-sectional view showing a state in which the master cylinder pressure is transmitted to the wheel cylinder side.

FIG. 13 is a partially enlarged vertical sectional view showing a state where the wheel cylinder pressure is reduced.

FIG. 14 is a braking force distribution diagram showing conventional problems.

[Explanation of symbols]

10 Traveling Motor 16 Inverter 18 Battery 20 EV ECU 26 Brake Pedal 28 Master Cylinder (M / C) 30, 42 Hydraulic Piping 32, 44 Wheel Cylinder (W / C) 34 Linear Valve (First Controllable Valve) 54 Reservoir 56 Regenerative ECU 62 Anti-lock brake system (ABS) 64 ABS ECU 66 Drain valve 68 Drain piping 72,74 Internal reservoir 76 ABS motor 78,80 Pump 82,86,90,98,310,312 Solenoid valve 92,94,96 Solenoid Valves (second controllable valves) 304, 306, 308 Linear valves (first and second controllable valves)
Control valve) T _BRK regenerative torque command T _RE return value ΔT _PRS introduced hydraulic torque ΔT _RE regenerative capacity recovery amount ΔT regenerative recovery limit value T _total total braking torque

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoyasu Enomoto 2-chome, Asahi-cho, Kariya city, Aichi Aisin Seiki Co., Ltd.

Claims (6)

[Claims] 1. A hydraulic braking force equivalent to a required braking force generated in a master cylinder is cut off to a predetermined hydraulic pressure and then transmitted to a wheel cylinder, whereby a hydraulic braking force smaller than the required braking force is applied, while the required braking force is reduced. Normal-time control means for applying a regenerative braking force corresponding to the difference in hydraulic braking force,
In a braking control device for an electric vehicle, which is provided with a regenerative invalidation control means for increasing the hydraulic braking force by an amount corresponding to the invalidation of the regenerative braking force when a situation occurs in which the desired regenerative braking force cannot be obtained due to the invalidation of the regenerative braking, If the regenerative braking force reaches a value equivalent to the required braking force by the control means at the time of invalidation and the regenerative braking force reaches a state where it can be recovered from the invalidation, the regenerative braking force is limited to the predetermined upper limit value as the recovery amount. A braking control device characterized by comprising a regenerative recovery means for recovering. 2. A hydraulic braking force, which is smaller than the required braking force, is applied by limiting the hydraulic pressure corresponding to the required braking force generated in the master cylinder to a predetermined hydraulic pressure and then transmitting the hydraulic pressure to the wheel cylinder. Normal-time control means for applying a regenerative braking force corresponding to the difference in hydraulic braking force,
In a braking control device for an electric vehicle, which is provided with a regenerative invalidation control means for increasing the hydraulic braking force by an amount corresponding to the invalidation of the regenerative braking force when a situation occurs in which the desired regenerative braking force cannot be obtained due to the invalidation of the regenerative braking, If the regenerative braking force becomes recoverable after the hydraulic braking force is controlled to increase to a value equivalent to the required braking force by the ineffective control means, the hydraulic braking force is reduced according to the recovery amount of the regenerative braking force. On the other hand, the braking control device is provided with a hydraulic pressure reduction regenerative recovery means for recovering the regenerative braking force according to the recovery amount. 3. The braking control device according to claim 2, wherein a first controllable valve is provided on the hydraulic pressure transmission path from the master cylinder to the wheel cylinder so as to control the valve opening pressure, and the wheel cylinder. Second, which is provided so that the braking fluid can be discharged from the
A controllable valve for controlling the opening pressure of the first controllable valve to the predetermined hydraulic pressure to shut off the hydraulic pressure in the master cylinder to the predetermined hydraulic pressure. And means for increasing the hydraulic braking force by an amount corresponding to the invalidation of the regenerative braking force by reducing the valve opening pressure of the first controllable valve. A braking control device comprising means for controlling the second controllable valve to discharge the braking fluid from the wheel cylinder to reduce the hydraulic pressure in the wheel cylinder according to the amount of recovery of the regenerative braking force. 4. The braking control device according to claim 3, wherein the second controllable valve is capable of discharging the brake fluid in the wheel cylinder to a predetermined reservoir and introducing the brake fluid in the reservoir into the wheel cylinder. This is a valve provided, and when the regenerative braking control means introduces the brake fluid of the master cylinder into the wheel cylinder when the desired regenerative braking force cannot be obtained due to the reactivation, the amount of brake fluid in the master cylinder is reduced. To determine whether or not the hydraulic pressure drops below a predetermined limit, and when it is determined that the hydraulic pressure does not decrease, the brake fluid is introduced from the master cylinder to the wheel cylinder by the control of the first controllable valve to regenerate the hydraulic braking force. A means for increasing the braking force by an amount corresponding to the expiration of the braking force, and when it is determined that the braking force will decrease, the brake fluid is introduced from the reservoir to the wheel cylinder by the control of the second controllable valve to control the hydraulic pressure. Brake control apparatus, characterized in that it comprises means for the force increases revocation equivalent of regenerative braking power. 5. The braking control device according to claim 3 or 4, wherein the first controllable valve and the second controllable valve are configured as a single valve. 6. The braking control device according to claim 3, wherein the second controllable valve is one of valves constituting an antilock brake system for preventing wheel lock. Control device.