JP2000308203A - Brake system of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake system, which can realize both a low cost structure and high regeneration efficiency and realize brake characteristics corresponding to the stroke of a brake pedal and free of sense of incongruity. SOLUTION: A brake system employs a low cost structure, wherein a negative pressure actuator 40 which relieves the stepping displacement of a brake pedal 1 via a balance mechanism 34 is provided in parallel with a master cylinder 10 having a negative pressure booster 10a, which generates a braking force by the stepping displacement of the brake pedal, and further, a solenoid valve 60 is provided in an atmosphere outlet 33 of the negative pressure booster 10a and the stepping displacement of the brake pedal 1 is shared between the master cylinder 10 and the negative pressure actuator 40 according to the operation ratio of a mechanical brake. With this constitution, high regeneration efficiency can be obtained at regenerative braking, and when mechanical braking becomes necessary, braking force generated by the mechanical brake is made to be applied regardless of the stop on displacement of the brake pedal 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vehicle brake system using both a mechanical brake and a regenerative brake.

[0002]

2. Description of the Related Art In an automobile (vehicle) having a traveling motor such as an electric automobile or a hybrid automobile, a regenerative brake is used in combination with a mechanical brake system using a master cylinder. The regenerative brake is a brake that is used when the vehicle is decelerated while the traveling motor functions as a generator and the deceleration energy is recovered by power generation from the motor.

In order to obtain a high regeneration rate in such an automobile, it is desirable to decelerate mainly with a regenerative brake and make up for the insufficient braking force with a mechanical brake.

Therefore, conventionally, a structure has been adopted in which a high oil pressure generated by an electric oil pump is supplied to a master cylinder, and the electric oil pump is controlled in accordance with the deceleration obtained from the detection of the stroke and depression force of a brake pedal,
If the obtained deceleration is a deceleration that can be covered by the regenerative brake, only the regenerative brake is operated, and if the deceleration of the regenerative brake is not enough, the hydraulic pressure generated by the electric oil pump is mastered by controlling the opening of various electromagnetic control valves. Lead to the cylinder,
Techniques have been proposed for supplementing the insufficient braking force with a mechanical brake.

[0005] Although high regenerative efficiency can be obtained in this brake system, the use of expensive electric oil pumps and various electromagnetic control valves causes a great cost burden.

[0006] In view of this, in addition to a structure for restricting the movement of an inexpensive mechanical brake system mounted on most types of automobiles, an area in which the mechanical brake system operates according to the distribution of the regenerative brake and the mechanical brake. Has been proposed to make it possible to control the temperature. For example, JP-A-3-27060
In Japanese Patent Laid-Open Publication No. 2 (1999) -2000, a region in which a mechanical brake operates is controlled by utilizing a master cylinder with a negative pressure booster operated by a brake pedal as it is. This publication discloses a technology in which a control valve is provided at the atmosphere port of a negative pressure booster to limit the negative pressure booster.

More specifically, in a negative pressure booster, when a brake pedal is depressed, a push rod moves, and the movement of the rod opens an air introduction valve portion, and a negative pressure sandwiching the diaphragm is generated. Atmospheric pressure is introduced into the rear chambers of the two chambers, and the diaphragm is moved to the distal end side by the pressure difference between the two chambers sandwiching the diaphragm. The master cylinder with negative pressure booster presses the master cylinder with the servo pressure generated in the diaphragm to generate the hydraulic pressure (fluid pressure) required for braking, and sends the hydraulic pressure to the wheel cylinder of a mechanical brake such as a disc brake. tell,
Generates braking force.

In the negative pressure control system, a control valve for opening and closing the atmosphere port is provided, and at the time of this mechanical brake, control for closing the atmosphere port is performed by the control valve, and both chambers sandwiching the diaphragm are sealed.
The diaphragm is prevented from moving, that is, the movement of the mechanical brake system is stopped, and during this time, the regenerative braking according to the depression force of the brake pedal is performed. When the braking force is insufficient, the insufficient amount is introduced into the atmosphere slightly from the atmosphere port, and a slight movement of the diaphragm generates a servo pressure corresponding to the insufficient amount to operate the master cylinder, thereby causing the insufficient amount. This technology supplements the braking force with a mechanical brake.

[0009]

An electric vehicle or a hybrid vehicle does not require a regenerative brake when a battery for supplying power to a regenerative running motor becomes full, so that at this time, only the regenerative brake is changed to a mechanical brake. Will be switched to

However, in the above-described brake system in which the movement of the mechanical brake system is simply restricted to control the area of the mechanical brake, the operation feeling of depressing the brake pedal may suddenly change.

That is, in order to operate only the mechanical brake, in the case of the negative pressure control type, the control valve is fully opened, the atmospheric pressure flows into the chamber behind the diaphragm, and a large servo pressure is generated from the diaphragm. However, when the mechanical brake system that has been stopped starts to move, a behavior in which the stroke of the brake pedal increases at that moment occurs.

For this reason, when switching to the mechanical brake, the stroke of the brake pedal increases at that moment,
Since the behavior that the driver's leg that continues to depress the brake pedal suddenly sinks occurs, the driver feels a great deal of discomfort.

The present invention has been made in view of the above circumstances. It is an object of the present invention to provide a brake characteristic that is compatible with an inexpensive structure and high regenerative efficiency and that does not cause a sense of incongruity according to the stroke of a brake pedal. An object of the present invention is to provide an obtained vehicle brake system.

[0014]

According to a first aspect of the present invention, there is provided a brake system, comprising: a mechanical brake system which generates a braking force by a stepping displacement of a brake pedal; A relief system is provided in parallel with a relief system for releasing the pedal depression displacement, and a transmission switching means for distributing the brake pedal depression displacement in accordance with the operation rate of the mechanical brake and transmitting it to the relief system and the mechanical brake system.

Thus, when only the regenerative brake is actuated, the displacement of the brake pedal being operated is released from the relief system. Then, since the regenerative braking is performed by the traveling motor in accordance with the displacement of the brake pedal at this time, when only the regenerative braking is performed,
Almost no mechanical braking is required, ensuring high regenerative efficiency.

If the regenerative brake becomes insufficient due to the deceleration, the transmission switching means reduces the displacement escaping from the relief system according to the braking force of the mechanical brake system, and instead increases the transmission to the mechanical brake system. That is, the transmitted distribution changes. As a result, the braking displacement by the mechanical brake is applied without changing the depression displacement of the brake pedal, and the insufficient braking force is compensated by the mechanical brake. Of course, even if you stop the regenerative brake and shift to all mechanical brakes, the stroke of the brake pedal does not change,
Since only the transmission distribution changes between the relief system and the mechanical brake system, the mode is smoothly switched from the regenerative brake to the mechanical brake, and a brake characteristic without a sense of incongruity according to the pedal stroke is obtained.

Moreover, utilizing a mechanical brake system,
Since this is a brake system that combines only the relief system and transmission switching means, an inexpensive structure can be used, and the cost burden can be reduced.

In addition to the above object, the brake system according to the second aspect of the present invention has a low production cost for a master cylinder with an inexpensive negative pressure booster which is used in almost all types of vehicles so that the cost can be reduced as much as possible. A structure in which a relief system constituted by an inexpensive negative pressure type actuator and a transmission switching means constituted by a control valve for controlling opening and closing of an atmosphere port of a master cylinder which is easy to control is adopted.

According to a third aspect of the present invention, in addition to the above object, the control valve depresses the brake pedal when the regenerative brake is operated so that the negative pressure type actuator is quickly operated during the regenerative braking. The closing operation was performed immediately before.

In the brake system according to the present invention, the negative pressure from the negative pressure source of the negative pressure booster is supplied to the negative pressure chamber constituting the negative pressure type actuator so that the negative pressure type actuator can be quickly operated. A bypass path for guiding the negative pressure of the first compartment to be received is provided, and a bypass valve for opening the bypass path immediately before the brake pedal is depressed when the regenerative brake is operated.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on a first embodiment shown in FIGS.

FIG. 1 shows a brake system of a vehicle to which the present invention is applied, for example, a hybrid vehicle (or an electric vehicle). In FIG. 1, reference numeral 1 denotes a brake pedal, and 2 denotes a pedal stroke for detecting the pedal stroke of the brake pedal 1. It is a sensor.

A mechanical brake system 3 is connected to the brake pedal 1. The mechanical brake system 3 includes, for example, a master cylinder 10 with a negative pressure booster 10a. More specifically, the negative pressure booster 10 a has a casing 12, for example, in which the inside is partitioned back and forth by a diaphragm 11. The compartments 13 and 14 (corresponding to the first compartment and the second compartment) are formed from the spaces on both sides before and after the diaphragm 11. The front compartment 13 is
It communicates with a negative pressure source, for example, a negative pressure pump (both not shown) through a check valve, so that the negative pressure is supplied from the negative pressure pump. At the center of the diaphragm 11, a bottomed cylindrical valve body 15 is attached so as to penetrate the diaphragm 11 with the bottom facing forward. The rod 16 protruding from the front end of the valve body 15
Are connected to a master cylinder 10 that generates hydraulic pressure (hydraulic pressure). The master cylinder 10 is connected to a mechanical brake device, for example, a wheel cylinder 19 a of a disc brake device 19 via a hydraulic pipe 18. Inside the valve body 15, a small-diameter cylinder chamber 20 is formed on the bottom side, and a large-diameter cylinder chamber 21 following the cylinder chamber 20 is formed on the opening side. The body part on the opening side where the cylinder chamber 21 is located is slidably fitted into a cylindrical housing part 22 formed to protrude rearward from the housing 12. A cushion member 23 and a slidable piece-shaped atmospheric valve 24 (corresponding to a valve portion) are accommodated in the cylinder chamber 20 from the bottom side. A slidable negative pressure valve 25 is provided at the bottom in the cylinder chamber 21.
(Corresponding to the valve). The negative pressure valve 25 has a compartment 12 and a compartment 1 formed through the bottom of the valve body 15.
3 and a valve hole 27 opened and closed by an atmosphere valve 24 is formed at the center.
The negative pressure valve 25 is moved to the port 26 by the cushion member 23 while the valve hole 27 is closed by the atmospheric valve 24.
Positioned away from the edge. This allows the compartments 13 and 14 to communicate with each other through the open port 26 (both compartments have negative pressure). The distal end of the push rod 30 penetrates slidably through the center of the end wall of the housing 22, and the distal end of the rod 30 abuts the rear end of the atmosphere valve 24 through the valve hole 27. The push rod 30 is provided with a spring member 31 for urging the negative pressure valve 25 forward. When the push rod 30 is displaced forward, the valve hole 27 is first closed due to the deformation of the cushion member 23. The negative pressure valve 25 moves forward in the
Close the six ends (cut off the communication between compartments 13 and 14), then
When the movement of the negative pressure valve 25 stops at the step between the cylinder chambers 20 and 21, the valve hole 27 is opened, and the atmosphere is released from the atmosphere port 33 formed in the peripheral wall of the housing 22 to the inside of the housing 22 and the valve. Hole 27, port 1 formed in the peripheral wall of cylinder chamber 20
Through 5a, it flows into the rear compartment 14. Accordingly, the generated servo pressure, that is, the pressure difference between both sides of the diaphragm 11,
Is moved to drive the master cylinder 10, and the cylinder 10 generates a hydraulic pressure required for operating the disk brake device 19. This push rod 3
The rear end of the brake pedal 1 is rotatably connected to a rotatable relay lever 1a extending from an intermediate portion of the brake pedal 1 via a balance mechanism 34. Thereby, the brake pedal 1
, A braking force is generated from the disc brake device 19. Reference numeral 35 denotes a return spring member.

A relief system 4 is provided in the body 12 of the negative pressure booster 10a, adjacent to the housing 22. The relief system 4 is composed of a negative pressure type actuator 40 which is assembled by utilizing a step space on the side of the housing 22.

To explain the negative pressure type actuator 40, reference numeral 41 denotes a body which is installed so as to fill a step space, for example, the rear side of which is open. A diaphragm 42 is attached to the inside of the body 41 so as to partition the front and rear, and a negative pressure chamber 4 is provided in a space on the front side sandwiching the diaphragm 42.
3 is formed, and an air chamber 44 communicating with the outside of the container 41 (atmosphere) is formed in the space on the rear side. And the negative pressure chamber 43
Through the through hole 43 a formed in the peripheral wall of the container 41 and the peripheral wall of the housing 22,
3 to the compartment 14). The distal end of a rod 45 slidably supported in the front-rear direction by a rod holder 41 a extending from the opening edge of the container 41 abuts the center of the diaphragm 42. The rear end of the rod 45 is connected to the balance mechanism 34.

The balance mechanism 34 has a lever member 50 disposed between the end of the push rod 30 and the end of the rod 45. The end of the relay lever 1a is rotatably connected to the center of the lever member 50. It is. A roller 51 for receiving the rod end of the mechanical brake system 3 is incorporated at one end of the lever member 50 across the end of the relay lever 1a, and the rod 45 of the negative pressure actuator 40 is received at the other end. Roller 52 is incorporated and brake pedal 1
The negative pressure type actuator 40 and the mechanical brake system 3 are combined in parallel so that the stepping displacement from the vehicle can be distributed to both sides. Reference numeral 42a denotes a return spring member of the negative pressure actuator 40.

A control valve, for example, a normally open type air release solenoid valve 60 is provided at the atmosphere port 33 of the negative pressure booster 10a.
(Hereinafter simply referred to as solenoid valve 60: corresponding to transmission switching means). By utilizing the closing operation of the solenoid valve 60 and the opening of the valve hole 27 of the negative pressure booster 10a by the pedal depressing force, the movement of the diaphragm 11 is restrained, that is, the transmission from the brake pedal 1 to the mechanical brake system 3 is cut off. Instead, the negative pressure actuator 40 is operated by the negative pressure flowing from the compartment 14 into the negative pressure chamber 43 to receive the displacement from the brake pedal 1 and absorb the displacement of the brake pedal 1 by the displacement of the diaphragm 42. It is. That is, the structure is such that the stepping displacement from the brake pedal 1 can be released.

The solenoid valve 60 and the pedal stroke sensor 2 are connected to a regenerative control unit 62 (for example, constituted by a microcomputer and corresponding to regenerative control means). The regenerative brake and the mechanical brake are controlled by the brake energy regeneration mode set in the regeneration control unit 62. That is, when, for example, the brake pedal 1 is depressed, the regenerative control unit 62 outputs the travel motor 63 according to the pedal stroke detected by the pedal stroke sensor 2.
A function of generating a braking force by regenerating (consisting of a motor generator), for example, deceleration of the own vehicle from the pedaling force of the brake pedal 1 detected by the pedaling force detection sensor 1b and the vehicle speed of a vehicle speed sensor (not shown). A function for determining whether or not the deceleration of the vehicle is smaller than the stroke of the vehicle by comparing the deceleration with the stroke of the brake pedal 1. When the deceleration is smaller than the stroke of the brake pedal 1, Is set so that the closed solenoid valve 60 is opened by duty control until it is determined that the braking force is insufficient and a braking force is supplied from the mechanical brake system 3 to supplement the braking force. By this duty control, the stepping displacement from the brake pedal 1 is distributed according to the braking force to be generated by the mechanical brake and transmitted to the mechanical brake system 3, and the rest is transmitted to the negative pressure actuator 40 and absorbed. It is so. That is,
The stepping displacement of the brake pedal 1 is distributed according to the operation rate of the mechanical brake and transmitted to the mechanical brake system 3 and the relief system 4.

In addition, the regenerative control unit 62 has a function of releasing the solenoid valve 60 to the atmosphere when sudden braking (brake pedal speed and pedaling force is large), and a charge amount of a running battery 64 mounted on an automobile. Is fully filled, that is, for example, when the current integrator 65 connected to the battery 64 exceeds a certain value, the function of gradually reducing the regenerative brake and gradually releasing the solenoid valve 60 is set. These features provide superior braking performance.

That is, the operation of the brake system will be described. It is assumed that the driver depresses the brake pedal 1 in order to decelerate the vehicle while the vehicle is running with the running motor.

At this time, in the brake energy regeneration mode, the regeneration control unit 62
With the pedal operation, the solenoid valve 60 is closed (fully closed).

Here, since the diaphragm 42 of the negative pressure actuator 40 in which the atmospheric pressure acts on both sides is held by the return spring member 42a, the stroke of the brake pedal 1 is initially passed through the balance mechanism 34. To the push rod 30 of the negative pressure booster 10a. Then, the push rod 30 starts moving forward while deforming the cushion member 23. As a result, first, as shown in FIG. 2, the negative pressure valve 25 is moved to the position where the port 26 is closed, and the communication between the compartments 13 and 14 is cut off. Thereby, the diaphragm 11 is regulated so as not to move (due to a negative pressure acting on both sides of the diaphragm 11). Subsequently, the atmospheric pressure valve 24 is closed and the negative pressure valve 25 is closed.
From the front to open the valve hole 27.

Then, the interior of the compartment 14 and the interior of the storage section 22 communicate with each other through the valve hole 27. Here, since the atmosphere port 33 is closed and shut off from the outside air, the negative pressure in the compartment 14 is applied to the housing 22 and the negative pressure chamber 43 of the negative pressure actuator 40 as shown by the arrow in FIG. Then, the negative pressure chamber 43 is filled with the negative pressure. As a result, the diaphragm 42 of the negative pressure actuator 40 moves forward due to a pressure difference from the atmosphere chamber 44.

Here, the forward movement of the push rod 30 of the negative pressure booster 10a is restricted by the restraint of the diaphragm 11, so that the lever member 50 of the balance mechanism 34 receives the opposite force from the push rod 30. Due to the force, the push rod 30 is pivotally displaced around the end thereof. As a result, the depression displacement (pedal stroke) of the brake pedal 1 is absorbed (runs away) by the diaphragm displacement of the negative pressure actuator 40 as it is.

During this time, the regenerative control unit 62 performs regenerative braking by the traveling motor 63 whose power generation is controlled according to the pedal stroke detected by the pedal stroke sensor 2.

During this deceleration, the regenerative control unit 62 determines the deceleration of the decelerating vehicle. When the deceleration is small with respect to the stepping displacement of the brake pedal 1, it is determined that deceleration is not sufficient only by deceleration of the regenerative brake, and the solenoid valve 60 is gradually opened by duty control until the deceleration is satisfied. . Then, the negative pressure escapes from the atmosphere port 33 to the atmosphere as indicated by the arrow in FIG. At this time, a force for returning the diaphragm 42 is generated by the inflow of the atmosphere into the atmosphere port 33. Atmosphere also flows into the compartment 14 of the negative pressure booster 10a, and the diaphragm 1
1 generates a force to move it forward (due to the pressure difference between the two sides of the diaphragm).

Then, the stepping displacement of the brake pedal 1 is not changed, and the lever member 50 is pivotally displaced with the end of the rod 1a as a fulcrum, so that the displacement escaping from the negative pressure actuator 40 is reduced. The distribution transmitted to both is changed in accordance with the magnitude of the braking force of the mechanical brake to be applied, as the transmission to the motor increases.

As a result, the master cylinder 10 is driven by the servo pressure generated by the diaphragm 11, and a braking force required for braking is generated. The insufficient braking force is supplemented by the mechanical brake.

When the battery 64 is fully charged during the regenerative braking and the regenerative braking is no longer required, the regenerative control unit 62 gradually reduces the regenerative braking, and further sets the atmosphere port 33 to the duty control of the solenoid valve 60. The compartment 14 of the negative pressure booster 10a, which is gradually opened to a negative pressure, and the negative pressure chamber 4 of the negative pressure actuator 40
3 is gradually brought to atmospheric pressure. Then, the displacement of the brake pedal 1 is not changed, and the lever member 50 is moved to the rod 1a.
Rotating displacement about the end as a fulcrum, the negative pressure actuator 40
The diaphragm 40 returns to the original position, and the diaphragm 11 of the negative pressure booster 10a moves instead by the differential pressure between the negative pressure and the atmospheric pressure.

Thus, the shift from the regenerative brake to the mechanical brake only by the mechanical brake system 3 is performed only by the change of the transmission distribution, and the necessary braking force is secured.

During regenerative braking, if a sudden braking operation (brake pedal speed, pedaling force: large) is performed,
The regenerative control unit 62 immediately opens the solenoid valve 60 fully, immediately opens the air port 33 to the atmosphere, and changes the transmission to a distribution in which the function of the mechanical brake system 3 is fully exhibited. As a result, a braking force that maximizes both the regenerative brake and the mechanical brake is generated.

As described above, in any case, the stroke of the brake pedal 1 does not change and the mechanical brake system 3
Since only the transmission distribution between the regenerative brake and the relief system 4 is changed, it is possible to smoothly switch from the regenerative brake to the mechanical brake, and to obtain a brake characteristic without a sense of incongruity according to the pedal stroke.

In addition, when only the regenerative brake is used, the mechanical brake is hardly required to operate, so that a high regenerative efficiency can be secured.

In addition, since the brake system only utilizes the mechanical brake system 3 and combines the relief system 4 and the transmission switching structure, the structure is inexpensive and the cost burden is small. Moreover, the brake system is an inexpensive negative pressure booster 10 used in most vehicle models.
The construction cost is low because the master cylinder 10 with a is a combination of the negative pressure actuator 40 with low manufacturing cost and the solenoid valve 60 that controls the opening and closing of the atmosphere port 33 that is easy to control. The cost can be further reduced. In addition, since the solenoid valve 60 is a normally open type, even if the solenoid valve 60 fails, the master cylinder 1 with the negative pressure booster 10a
The function of No. 0 can be left as it is, and it is also excellent in the face safety.

FIG. 4 shows a second embodiment of the present invention.

In the present embodiment, in order to obtain a regenerative brake in which the useless operation of the master cylinder 10 with the negative pressure booster 10a is suppressed, the brake system of the first embodiment is provided with a negative pressure during regenerative braking. Actuator 40
It is a device that makes it stand up quickly.

In the present embodiment, first, when the regenerative brake is operated using the regenerative control unit 62 and the pedal stroke sensor 71, the closing operation of the solenoid valve 60 is started immediately before the brake pedal 1 is depressed. A trick to get started.

More specifically, an accelerator pedal 70 is provided with an accelerator pedal sensor 71 for detecting the accelerator pedal stroke. When the accelerator pedal stroke detected by the accelerator pedal sensor 71 becomes equal to or smaller than a predetermined value,
When the regenerative brake is operated by closing the solenoid valve 60, the negative pressure chamber 43 of the negative pressure actuator 40 can be immediately filled with the negative pressure without unnecessary delay. The solenoid valve 60 may be closed when the brake pedal 1 is displaced by a certain value or more in the play area.

Second, when the regenerative brake is operated, the negative pressure from the compartment 13 of the negative pressure booster 10a, which receives the negative pressure directly from the negative pressure source, is supplied to the negative pressure chamber of the negative pressure actuator 40. The device 43 is designed to flow in immediately before the brake pedal 1 is depressed.

Specifically, the compartment 1 of the negative pressure booster 10a
A bypass path 75 for guiding negative pressure from 3 to the negative pressure chamber 43 of the negative pressure actuator 40 is provided. When the on-off valve 76
As described above, when the accelerator pedal stroke detected by the accelerator pedal sensor 71 is equal to or less than a certain value,
Alternatively, the negative pressure chamber 43 of the negative pressure actuator 40 can be immediately filled with a negative pressure without unnecessary delay when the brake pedal 1 is displaced to a predetermined value or more in a play area and closed and the regenerative brake is operated. Things.

As described above, if the negative pressure chamber 43 is quickly raised before the brake pedal 1 is depressed during the regenerative braking, more excellent braking characteristics can be obtained.

[0052]

As described above, according to the first aspect of the present invention, it is possible to obtain a brake characteristic that does not cause a sense of incongruity according to the stroke of a brake pedal, while achieving both an inexpensive structure and high regenerative efficiency. it can.

According to the second aspect of the present invention, since the structure is such that an inexpensive negative pressure type actuator is combined with a more inexpensive negative pressure booster-equipped master cylinder, the cost can be further reduced. This has the effect.

According to the third and fourth aspects of the present invention, during regenerative braking, the negative pressure type actuator can be started up before the brake pedal is depressed. There is an effect that unnecessary work of the attached master cylinder can be suppressed, and the regeneration efficiency can be further increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a vehicle brake system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a case where regenerative braking is performed by the brake system.

FIG. 3 is a diagram illustrating a case where a mechanical brake is applied to a regenerative brake in the brake system.

FIG. 4 is a diagram illustrating a configuration of a vehicle brake system according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Brake pedal 3 ... Mechanical brake system 4 ... Relief system 10a ... Negative pressure booster 10 ... Master cylinder 11 ... Diaphragm of negative pressure booster 13, 14 ... 1st compartment, 2nd compartment 19 ... Disc brake device (machine 24, 25 ... atmospheric valve, negative pressure valve (valve part) 34 ... balance mechanism 40 ... negative pressure actuator 42 ... diaphragm of negative pressure actuator 43 ... negative pressure chamber 44 ... atmospheric chamber 60 ... solenoid valve (transmission switching means) 62: Regenerative control unit (regenerative control unit) 75: Bypass path 76: Open / close valve (bypass valve).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D048 AA06 BB25 BB27 CC26 CC49 HH18 HH26 HH42 HH66 HH67 RR01 RR02 RR11 RR25 RR35 5H115 PA01 PA11 PC06 PG04 PI16 PI29 PU01 PU21 QE10 QI04 QI07 QI15 QN03 TO10 SE23

Claims (4)

[Claims] 1. A brake system for a vehicle, comprising: a mechanical brake for braking by operating a brake pedal; and a regenerative brake for regeneratively braking by a traveling motor. A mechanical brake system that generates power, a regenerative control unit that generates a braking force by regenerating a travel motor in accordance with a stepping displacement of the brake pedal when a regenerative brake is operated, and a mechanical brake system in parallel with the mechanical brake system. When the regenerative brake is actuated, a relief system that releases the stepping displacement of the brake pedal when the regenerative brake is actuated, and when the mechanical brake is activated, the stepping displacement of the brake pedal is distributed according to the operation rate of the mechanical brake, and the relief system is provided. Transmission switching means for transmitting to the mechanical brake system. Brake system. 2. The mechanical brake system according to claim 1, wherein the mechanical brake system includes a push rod that receives a stepping displacement of the brake pedal, a first compartment that receives a negative pressure from a negative pressure source on one side of a diaphragm, and the other compartment on the other side. A second compartment communicating with the first compartment, wherein the first compartment is moved in accordance with the displacement of the bush rod;
A negative pressure booster configured to have a valve section that cuts off communication between the compartment and the second compartment and introduces air from the atmosphere port to the second compartment; and a servo pressure generated by the diaphragm. A master cylinder that generates a hydraulic pressure necessary for the operation of the mechanical brake device.The relief system is configured to perform a stepping displacement from the brake pedal in parallel with the mechanical brake system via a balance mechanism. Having a negative pressure chamber communicating with a flow path from the atmosphere port to the second compartment on one side sandwiching the diaphragm, and having an atmosphere chamber to which atmospheric pressure is applied on the other side. 2. The vehicle brake according to claim 1, wherein the transmission switching unit includes a control valve that controls opening and closing of the air outlet according to distribution of a regenerative brake and a mechanical brake. 3. system. 3. The vehicle brake system according to claim 2, wherein the control valve is controlled to start a closing operation immediately before depressing the brake pedal when a regenerative brake is operated. . 4. The negative pressure chamber is provided with a first pressure of the negative pressure booster.
A bypass path for introducing a negative pressure from the compartment, and a bypass valve for opening the bypass path immediately before the brake pedal is depressed when a regenerative brake is operated. The brake system according to claim 2 or 3.