JPH11215606A - Two-system hydraulic brake for electric motor car with regenerative brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piped-into-x-shape two-system hydraulic brake for electric motor cars with a regenerative brake, which has a simple construction and does not increase the stroke of a brake pedal suddenly at the time of switchover of regenerative braking. SOLUTION: Between the hydraulic regulator 13 of a dynamic system and each of wheel brake cylinders 10A, 10B, a hydraulic pressure controller 19A or 19B which makes the hydraulic pressure of a wheel brake cylinder lower than the output hydraulic pressure of a hydraulic regulator at a regenerative braking time, and makes it eqaul to the hydraulic output pressure of the hydraulic regulator at the time of nonregenerative braking, is provided. Between the master cylinder 12 of a static hydraulic system and each of wheel brake cylinders 10B, 10C, a hydraulic pressure controller 20A or 20B which makes the hydraulic pressure of the wheel brake cylinder lower than that of the master cylinder at a normal time of the dynamic hydraulic system, and makes it equal to the hydraulic pressure of the master cylinder at the time of failure of the dynamic hydraulic system, is provided. Hydraulic pressure transmitting pistons 21A, 21B for tranmitting the hydraulic pressures of the wheel brake cylinders 10A, 10D to the wheel brake cylinders 10B, 10C are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual hydraulic braking system for an electric vehicle with a regenerative braking system.

[0002]

2. Description of the Related Art As a dual system hydraulic braking device for an electric vehicle with a regenerative braking device, there is one disclosed in, for example, Japanese Patent Application Laid-Open No. 7-336806. This hydraulic braking device includes a hydraulic booster that outputs a static hydraulic pressure and a dynamic hydraulic pressure corresponding to the operating force of the brake operating member according to the operation of the brake operating member. The static hydraulic pressure output by the hydraulic booster is supplied to the front right wheel brake cylinder and the front left wheel brake cylinder applied to the right and left wheels at the front of the vehicle, respectively, and the dynamic hydraulic pressure output by the hydraulic booster is also provided. The pressure is supplied to a rear right wheel brake cylinder and a rear left wheel brake cylinder which are applied to right and left wheels at the rear of the vehicle, respectively.

In the above-mentioned hydraulic braking device, when the required braking force exceeds the regenerative braking force, a shortage, which is the difference between the two, is generated by the wheel brake cylinder. A hydraulic path for supplying the front right wheel brake cylinder and the front left wheel brake cylinder and a hydraulic path for supplying dynamic hydraulic pressure from the hydraulic booster to the rear right wheel brake cylinder and the rear left wheel brake cylinder, respectively. When the regenerative braking is performed, the hydraulic pressure supplied from the hydraulic booster to each wheel brake cylinder is lower than the output hydraulic pressure of the hydraulic booster, and when the regenerative braking is not performed, the hydraulic pressure is supplied from the hydraulic booster to each wheel brake cylinder. Hydraulic pressure to match supplied hydraulic pressure to hydraulic booster output hydraulic pressure Your device is interposed. This hydraulic pressure control device is configured by connecting an initial cut valve responsive to hydraulic pressure, a differential pressure generating valve responsive to hydraulic pressure, and an open / close electromagnetic valve in parallel with each other.

Further, in the above-described hydraulic braking apparatus, when switching from a state in which regenerative braking is performed to a state in which regenerative braking is not performed, the stroke amount of a brake operating member suddenly increases, and this gives a feeling of strangeness to a vehicle driver. To prevent this, the dynamic hydraulic pressure output by the hydraulic booster when switching from a state in which regenerative braking is performed to a state in which regenerative braking is not performed is temporarily supplied to the front right wheel brake cylinder and the front left wheel brake cylinder. A switching valve device is provided.

[0005]

A two-system hydraulic braking system for a vehicle that is put into practical use today, like the above-mentioned hydraulic braking system, applies one output hydraulic pressure corresponding to the brake operating force to the front right wheel brake. A cylinder configured to supply the output hydraulic pressure to the cylinder and the front left wheel brake cylinder and the other output hydraulic pressure to the rear right wheel brake cylinder and the rear left wheel brake cylinder, and an output hydraulic pressure corresponding to the brake operating force. There is an X-pipe type that is configured to supply a front right wheel brake cylinder and a rear left wheel brake cylinder and supply the other output hydraulic pressure to a front left wheel brake cylinder and a rear right wheel brake cylinder.

The invention of this application is directed to a dual system hydraulic braking system of the X-pipe type for an electric vehicle with a regenerative braking device, wherein when the required braking force exceeds the regenerative braking force, a difference is generated by the hydraulic braking device. An object of the present invention is to prevent a sudden increase in the stroke amount of a brake operation member when switching from a state in which regenerative braking is performed to a state in which regenerative braking is not performed, and to simplify the configuration.

[0007]

The invention of claim 1 of the present application is directed to a dual system hydraulic braking device for an electric vehicle with a regenerative braking device, wherein the first wheel on the left and right side of the front of the vehicle, First, second, third and fourth for applying a braking force to the second wheel on the left and right side on the other side, the third wheel on the left and right side on the rear of the vehicle, and the fourth wheel on the left and right side on the other side of the vehicle, respectively. A wheel brake cylinder, static hydraulic pressure output means for outputting a static hydraulic pressure having a magnitude corresponding to the brake operating force according to the operation of the brake operating member, and a brake operating force corresponding to the operation of the brake operating member. Dynamic hydraulic pressure output means for outputting a dynamic hydraulic pressure of a corresponding magnitude; and an output hydraulic pressure of the dynamic hydraulic pressure output means,
And a first hydraulic passage for supplying to the fourth wheel brake cylinder, and a second hydraulic passage for supplying the output hydraulic pressure of the static hydraulic pressure output means to the second and third wheel brake cylinders. When the regenerative braking is performed, a hydraulic pressure supplied from the dynamic hydraulic pressure output means to the first and fourth wheel brake cylinders is interposed in the hydraulic pressure path and the first hydraulic pressure path. When the regenerative braking is not performed, the hydraulic pressure supplied from the dynamic hydraulic pressure output means to the first and fourth wheel brake cylinders is lower than the output hydraulic pressure of the dynamic hydraulic pressure output means. A first hydraulic pressure control unit that matches the output hydraulic pressure of the pressure output unit; and a static hydraulic pressure unit that is interposed in the second hydraulic pressure line, and the output hydraulic pressure of the dynamic hydraulic pressure is normal if the output hydraulic pressure is normal. Liquid supplied from output means to the second and third wheel brake cylinders Lower than the output hydraulic pressure of the static hydraulic pressure output means, and when the output hydraulic pressure of the dynamic hydraulic pressure output means has failed, the static hydraulic pressure output means outputs the second and third wheel brake cylinders. Second hydraulic pressure control means for making the hydraulic pressure supplied to the hydraulic pressure equal to the output hydraulic pressure of the static hydraulic pressure output means, and the wheel brake cylinder side hydraulic pressure of the first hydraulic pressure control means to the second hydraulic pressure control means. And a hydraulic pressure transmitting piston means for transmitting the hydraulic pressure to the wheel brake cylinder side of the hydraulic pressure control means.

According to a second aspect of the present invention, there is provided a dual-system hydraulic braking system for an electric vehicle with a regenerative braking system according to the first aspect, wherein the first hydraulic pressure control means includes a first wheel. A hydraulic pressure control means for the brake cylinder and another hydraulic pressure control means for the fourth wheel brake cylinder, wherein the second hydraulic pressure control means is A hydraulic control means for the second wheel brake cylinder and another hydraulic control means for the third wheel brake cylinder, wherein the hydraulic pressure transmitting piston means is Hydraulic transmission piston means for first and second wheel brake cylinders and said third
And a hydraulic pressure transmitting piston means for a fourth wheel brake cylinder.

According to a third aspect of the present invention, there is provided a dual-system hydraulic braking system for an electric vehicle with a regenerative braking system according to the first or second aspect, wherein the first hydraulic control means includes a hydraulic control unit. An initial cut valve responsive to pressure, a differential pressure generating valve responsive to hydraulic pressure, and an open / close electromagnetic valve are connected in parallel with each other, and the second hydraulic pressure control means includes an initial cut valve responsive to hydraulic pressure, A regenerative braking device comprising: a piston that forcibly opens an initial cut valve by an output hydraulic pressure of the static hydraulic pressure output unit when an output hydraulic pressure of the dynamic hydraulic pressure output unit has failed. 2 is a two-system hydraulic braking device for an electric vehicle equipped with.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, FL is a front left wheel of a vehicle, FR is a front right wheel of a vehicle, RL is a rear left wheel of a vehicle, and RR is a rear right wheel of a vehicle.
An electric motor connected to the wheels FL and FR and / or the wheels RL and RR, and a driving force applied to the wheels connected to the electric motor by rotationally driving the electric motor, and by regenerative braking of the electric motor A control device for applying a braking force to wheels connected to the electric motor is not shown. Wheel brake cylinders 10A, 10B, 10C and 10D for applying a braking force to wheels FL, FR, RL and RR
Are attached.

A brake pedal 11 as a brake operating member according to the first aspect is operatively connected to a master cylinder 12 and operatively connected to a hydraulic pressure regulator 13 via the master cylinder 12.
The hydraulic pressure regulator 13 adjusts the high-pressure dynamic hydraulic pressure supplied from the accumulator 14 to a hydraulic pressure corresponding to the depression force of the brake pedal 11 according to the depression of the brake pedal 11, and outputs the hydraulic pressure to the hydraulic pressure path 17. The electric hydraulic pump 15 connected to the accumulator 14
The hydraulic pressure in the accumulator is driven in response to the hydraulic pressure within the lower limit being lower than a predetermined lower limit and is supplied to the accumulator 14 by boosting the brake fluid in the brake fluid reservoir 16, whereby the hydraulic pressure in the accumulator rises and exceeds a predetermined upper limit. Will be stopped accordingly. Hydraulic pressure regulator 13, accumulator 1
4. Electric hydraulic pump 15 and brake fluid reservoir 16
Thus, the dynamic hydraulic pressure output means in claim 1 is constituted. The master cylinder 12 is the brake fluid reservoir 1
The brake fluid supplied from 6 is boosted in accordance with the depression of the brake pedal 11, and a static fluid pressure corresponding to the depression force of the brake pedal 11 is output to the fluid pressure passage 18. Master cylinder 1
The first and brake fluid reservoirs 16 constitute a static hydraulic pressure output means in the first aspect.

The hydraulic passage 17 has branch passages 17a, 17b and 17c. Forks 17a and 17b are connected to wheel brake cylinders 10A and 10D, respectively. Hydraulic pressure control devices 19A and 19B are interposed in the branches 17a and 17b, respectively. The hydraulic pressure control device 19A includes an initial cut valve 19 that responds to hydraulic pressure.
A1 and a differential pressure generating valve 19A2 responsive to the fluid pressure, and an opening / closing electromagnetic valve 19A3 are connected in parallel with each other. The initial cut valve 19A1 is made of the same component as a well-known proportioning valve, and as shown in FIG. When the hydraulic pressure on the wheel brake cylinder side is equal to or higher than the set value, the hydraulic pressure on the wheel brake cylinder side hardly increases (for example, (The pressure is gradually increased at a hydraulic pressure rising gradient of 0.1). The differential pressure generating valve 19A2 is made of the same component as a well-known relief valve. As shown in FIG. 4, the wheel brake cylinder side hydraulic pressure is set lower than the hydraulic regulator side hydraulic pressure by a set differential pressure ΔP. Has hydraulic control characteristics.
The opening / closing electromagnetic valve 19A3 is closed when performing regenerative braking during vehicle braking. Therefore, when regenerative braking is performed, the hydraulic pressure supplied to the wheel brake cylinder 10A becomes lower than the hydraulic pressure on the hydraulic pressure regulator side as shown by the solid line in FIG. When the regenerative braking is not performed, the opening / closing electromagnetic valve 19A3 is opened, so that the hydraulic pressure supplied to the wheel brake cylinder 10A becomes as shown by the broken line in FIG. Matches.

The hydraulic pressure control device 19B is
As in A, the initial cut valve 19B1 that responds to the hydraulic pressure
And a differential pressure generating valve 19B2 responsive to the fluid pressure and an opening / closing electromagnetic valve 19B3 are connected in parallel with each other.

The hydraulic pressure control devices 19A and 19B constitute the first hydraulic pressure control means in claim 1.

The hydraulic passage 18 from which the master cylinder 12 outputs the static hydraulic pressure has branch passages 18a, 18b and 18c. Forks 18a and 18b are connected to wheel brake cylinders 10B and 10C, respectively. FIGS. 18a and 18b show a hydraulic control device 20;
A and 20B are interposed respectively. The hydraulic pressure control device 20A supplies an output hydraulic pressure of the master cylinder 12 to the hydraulic pressure-responsive initial cut valve having the same components as the well-known proportioning valve in response to the output hydraulic pressure of the hydraulic pressure regulator 13 falling. A piston is additionally provided which operates by pressure to forcibly open an initial cut valve. That is, as shown in FIG. 2, the master cylinder connection port 20A1 and the wheel brake cylinder connection port 20
An annular valve member 20A4 made of an elastic material, a hydraulic responsive piston 20A5 for opening and closing a central opening of the valve member 20A4, and a hydraulic responsive piston 2 in a body 20A3 having A2.
An initial cut valve 20A7 is provided with a spring 20A6 that urges 0A5 in the opening direction of the central opening of the valve member 20A4. In addition, the hydraulic pressure-responsive piston 2
An air chamber 20A8 is formed at one end of 0A5. The stepped piston 20A9 is fitted on the inner periphery of the body 20A3 to form an annular hydraulic chamber 20A10. The hydraulic pressure of the branch passage 17a is introduced into the annular hydraulic chamber 20A10, and one end of the spring 20A6 is stepped. Piston 20A
When the output hydraulic pressure of the hydraulic pressure regulator 13 is normal, the stepped piston 20A9 is positioned as shown in FIG. 2 and the operation of the initial cut valve 20A7 is not limited. When the output hydraulic pressure fails, the stepped piston 20A9
The stepped piston 20A9 abuts against the hydraulically responsive piston 20A5, and the stepped piston 20A9 is brought into contact with the valve member 20A.
4 is held at the open position of the central opening. The hydraulic control characteristic of the initial cut valve 20A7 is the same as the hydraulic control characteristic of the initial cut valve 19A1 of the hydraulic control device 19A.

The hydraulic pressure control device 20B is also a hydraulic pressure control device 20A.
The hydraulic pressure control characteristics of the initial cut valve of the hydraulic pressure control device 20B are the same as the hydraulic pressure control characteristics of the initial cut valve 19B1 of the hydraulic pressure control device 19B. The introduction of the output hydraulic pressure of the hydraulic pressure regulator 13 to the hydraulic pressure control device 20B is performed by the branch passage 17b.
Done from The second hydraulic pressure control means in claim 1 is constituted by the hydraulic pressure control devices 20A and 20B.

When the output hydraulic pressure of the hydraulic pressure regulator 13 is normal, the wheel brake cylinders 10B and 10C
The hydraulic pressure transmitting the hydraulic pressure of the hydraulic pressure control device 19A to the wheel brake cylinder side of the hydraulic pressure control device 20A to the hydraulic pressure of the hydraulic pressure control device 20A to substantially equalize the hydraulic pressure of the hydraulic brake device 10A and the hydraulic pressure of the wheel brake cylinders 10D Transmission piston 21A
And a hydraulic pressure transmitting piston 21B for transmitting the hydraulic pressure on the wheel brake cylinder side of the hydraulic pressure control device 19B to the wheel brake cylinder side of the hydraulic pressure control device 20B. The hydraulic pressure transmitting piston means in claim 1 is constituted by the hydraulic pressure transmitting pistons 21A and 21B.

To generate an appropriate stroke on the piston of the master cylinder 12 when the brake pedal 11 is depressed, a stroke simulator 22
Is connected.

Further, in order to be able to perform the antilock control, the branch passages 17a, 17b, 18a and 18b are provided at a position closer to the wheel brake cylinder than the connection point with the hydraulic pressure transmitting pistons 21A and 21B. , Normally open / closed electromagnetic valves 23A, 23B, 23C and 23D are interposed, and branch passages 17a, 17b, 18a and 18b are provided with open / close electromagnetic valves 23A, 23B and 23C.
At positions closer to the wheel brake cylinder than at positions 23D and 23D, they are connected to the brake fluid reservoir 16 via normally open / close electromagnetic valves 24A, 24B, 24C and 24D. When the anti-lock control is performed, the brake pedal 1
In order to avoid an increase in one stroke, switching electromagnetic valves 25A and 25B for introducing dynamic hydraulic pressure from the branch paths 17a and 17b are interposed in the branch paths 18a and 18b, respectively.

X with a regenerative braking device having the above-described configuration
In the two-line hydraulic brake system, the hydraulic control device 19
By controlling the opening / closing electromagnetic valve 19A3 of A to make the hydraulic pressure of the wheel brake cylinder 10A lower than the output hydraulic pressure of the hydraulic pressure regulator 13 or to make the hydraulic pressure regulator 13 match the output hydraulic pressure, The hydraulic pressure of the wheel brake cylinder 10B is also substantially equal to the wheel brake cylinder 1
It is the same as the hydraulic pressure of 0A. Similarly, the hydraulic pressure control device 19B
The opening / closing electromagnetic valve 19B3 is controlled to make the hydraulic pressure of the wheel brake cylinder 10D lower than the output hydraulic pressure of the hydraulic pressure regulator 13 or to make the hydraulic pressure regulator 13 match the output hydraulic pressure. The hydraulic pressure of the brake cylinder 10C is also substantially equal to the wheel brake cylinder 10C.
It becomes the same as the hydraulic pressure of D. Opening / closing solenoid valves 19A3, 19
The solenoid valve 19A is opened and closed to switch from a state in which regenerative braking is performed by closing B3 to a state in which regenerative braking is not performed.
3, 19B3 open, wheel brake cylinder 1
The hydraulic pressures of 0B and 10C correspond to the hydraulic pressure transmission pistons 21A and 21C.
Since the pressure is increased using the dynamic hydraulic pressure output by the hydraulic pressure regulator 13 according to B, the stroke amount of the brake pedal 11 does not suddenly increase. And the hydraulic pressure control device 1
Wheel brake cylinders 10A, 1A by 9A, 19B
0B and the hydraulic pressure of the wheel brake cylinders 10C and 10D can be individually controlled, so that the distribution between the braking force of the vehicle front wheels FL and FR and the braking force of the vehicle rear wheels RL and RR can be controlled. Can also be performed appropriately. Further, when the output hydraulic pressure of the hydraulic pressure regulator 13 has failed, the hydraulic pressure control devices 20A and 20B
Since the hydraulic pressure of 0C is made equal to the output hydraulic pressure of the master cylinder, a sufficient braking force can be secured.

According to the prior art, the hydraulic pressure control device 20A,
Instead of providing the hydraulic pressure transmission pistons 21A and 21B and the hydraulic pressure control devices 19A and 21B, the same hydraulic pressure control devices as the hydraulic pressure control devices 19A and 19B are interposed in the branch passages 18a and 18b. Hydraulic pressure transmission pistons 21A, 2
The configuration is simpler when 1B is provided.

When the wheels FL, FR, RL, RR are connected to an electric motor, the hydraulic pressure control device 19A,
19B, one of the hydraulic pressure control devices 20A and 20B, one of the hydraulic pressure transmitting pistons 21A and 21B, and one of the switching electromagnetic valves 25A and 25B may be omitted. For example, the output hydraulic pressure of the hydraulic pressure regulator 13 is supplied to the wheel brake cylinders 10A and 10D via the hydraulic pressure control device 19A, and the output hydraulic pressure of the master cylinder is supplied to the wheel brake cylinders via the hydraulic pressure control device 20A and the switching electromagnetic valve 25A. It may be supplied to the brake cylinders 10B and 10C.

[0023]

As described above, the X-pipe dual-system hydraulic braking system for an electric vehicle with a regenerative braking device according to the invention of the present application has a difference when the required braking force exceeds the regenerative braking force. Is generated by the hydraulic braking device, and a sudden increase in the stroke amount of the brake operating member when switching from a state in which regenerative braking is performed to a state in which regenerative braking is not performed can be prevented, and the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram of a two-system hydraulic braking device according to the invention of this application.

FIG. 2 is a diagram showing details of a hydraulic control device 20A in FIG. 1;

FIG. 3 is a diagram showing a hydraulic control characteristic of an initial cut valve 19A1 in FIG. 1;

FIG. 4 is a view showing a hydraulic control characteristic of a differential pressure generating valve 19A2 in FIG. 1;

FIG. 5 is a view showing a hydraulic control characteristic of a hydraulic control device 19A in FIG. 1;

[Description of sign]

 DESCRIPTION OF SYMBOLS 11 ... Brake pedal 12 ... Master cylinder 13 ... Hydraulic pressure regulator 14 ... Accumulator 15 ... Electric hydraulic pump 16 ... Brake fluid reservoir 17 ... Hydraulic pressure path 18 ... Hydraulic pressure path 19A ・ ・ ・ Hydraulic pressure control device 19A1 ・ ・ ・ Initial cut valve 19A2 ・ ・ ・ Differential pressure generating valve 19A3 ・ ・ ・ Opening / closing electromagnetic valve 19B ・ ・ ・ Hydraulic pressure control device 19B1 ・ ・ ・ Initial cut valve 19B2 ・..Differential pressure generating valve 19B3: open / close electromagnetic valve 20A: hydraulic pressure control device 20A7: initial cut valve 20A9: stepped piston 20B: hydraulic pressure control device 21A: hydraulic pressure transmission Piston 21B: hydraulic pressure transmission piston

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Taku Nagashima 2-1-1 Asahi-cho, Kariya-shi, Aichi Prefecture Aisin Seiki Co., Ltd.

Claims (3)

[Claims] 1. A two-system hydraulic braking device for an electric vehicle with a regenerative braking device, comprising: a first wheel on the left and right side of the front part of the vehicle; Third on the side
First, second, third and fourth wheel brake cylinders for applying a braking force to the first wheel and the fourth wheel on the other side of the rear left and right sides of the vehicle, respectively, and according to the brake operating force in accordance with the operation of the brake operating member Hydraulic pressure output means for outputting a static hydraulic pressure having a magnitude corresponding to a dynamic hydraulic pressure output means for outputting a dynamic hydraulic pressure having a magnitude corresponding to a brake operating force in response to operation of the brake operating member A first hydraulic pressure path for supplying an output hydraulic pressure of the dynamic hydraulic pressure output means to the first and fourth wheel brake cylinders; and an output hydraulic pressure of the static hydraulic pressure output means. A second hydraulic pressure passage for supplying to the second and third wheel brake cylinders, and a second hydraulic pressure passage interposed between the first hydraulic pressure passage and the dynamic hydraulic pressure output means for performing the regenerative braking. The hydraulic pressure supplied to the first and fourth wheel brake cylinders is When the regenerative braking is not performed, the hydraulic pressure supplied from the dynamic hydraulic pressure output means to the first and fourth wheel brake cylinders is lower than the output hydraulic pressure of the dynamic hydraulic pressure output means. A first hydraulic pressure control unit that matches the output hydraulic pressure of the pressure output unit; and a static hydraulic pressure unit that is interposed in the second hydraulic pressure line, and the output hydraulic pressure of the dynamic hydraulic pressure is normal if the output hydraulic pressure is normal. The hydraulic pressure supplied from the output means to the second and third wheel brake cylinders is lower than the output hydraulic pressure of the static hydraulic pressure output means, and the output hydraulic pressure of the dynamic hydraulic pressure output means has failed. Sometimes, the static hydraulic pressure output means outputs the second
And second hydraulic pressure control means for matching the hydraulic pressure supplied to the third wheel brake cylinder to the output hydraulic pressure of the static hydraulic pressure output means, and a wheel brake cylinder side of the first hydraulic pressure control means A hydraulic pressure transmitting piston means for transmitting a hydraulic pressure to a wheel brake cylinder side of the second hydraulic pressure control means. 2. The two-system hydraulic braking device for an electric vehicle with a regenerative braking device according to claim 1, wherein said first hydraulic pressure control means controls hydraulic pressure for said first wheel brake cylinder. Means and a hydraulic control means separate from the hydraulic control means, the hydraulic control means comprising a hydraulic control means for the fourth wheel brake cylinder, wherein the second hydraulic control means comprises a second hydraulic brake control means. A hydraulic pressure control means for the cylinder and a hydraulic pressure control means different from the hydraulic pressure control means, the hydraulic pressure control means for the third wheel brake cylinder; An electric vehicle with a regenerative braking device, comprising: hydraulic pressure transmitting piston means for first and second wheel brake cylinders; and hydraulic pressure transmitting piston means for the third and fourth wheel brake cylinders. Two-system liquid Pressure braking device. 3. The two-system hydraulic braking device for an electric vehicle with a regenerative braking device according to claim 1, wherein the first hydraulic pressure control means is an initial cut valve responsive to a hydraulic pressure. A differential pressure generating valve and an opening / closing solenoid valve responsive to hydraulic pressure are connected in parallel to each other, and the second hydraulic pressure control means is configured to control an initial cut valve responsive to hydraulic pressure and an output of the dynamic hydraulic pressure output means. And a piston forcibly opening an initial cut valve by an output hydraulic pressure of the static hydraulic pressure output means when a hydraulic pressure fails. Braking device.