CN214355961U

CN214355961U - Electric control hydraulic braking system

Info

Publication number: CN214355961U
Application number: CN202023061562.7U
Authority: CN
Inventors: 范鹏; 朱心放; 张彦朝; 苗会彬; 刘海珍; 刘倩
Original assignee: Nasn Automotive Electronics Co Ltd
Current assignee: Nasn Automotive Electronics Co Ltd
Priority date: 2020-12-17
Filing date: 2020-12-17
Publication date: 2021-10-08
Anticipated expiration: 2030-12-17

Abstract

The utility model discloses an automatically controlled hydraulic braking system includes oil tank, first jar, second jar, driving piece, feed liquor valve, first fluid circuit and second fluid circuit, and the first piston of driving piece drive second jar removes, and first fluid circuit is located between first jar and the feed liquor valve, and the second fluid circuit is located between second jar and the feed liquor valve, but first fluid circuit and second fluid circuit alternative ground with the feed liquor valve intercommunication. The utility model discloses an automatically controlled hydraulic braking system, through the design of oil circuit, can realize three kinds of braking modes, can satisfy the braking demand when automatically controlled became invalid, the system reliability is higher, can satisfy multiple different braking force demands again, can adapt to the requirement to braking system in the current intelligent driving; and the system has high integration level, light weight, relatively low cost and obvious product advantages.

Description

Electric control hydraulic braking system

Technical Field

The utility model relates to an automobile brake system technical field especially relates to an automatically controlled hydraulic braking system.

Background

The traditional automobile braking system can be divided into a manual braking system, a dynamic braking system, a servo braking system and the like, but along with the development of the electric automobile industry, the braking system in the existing automobile field has the technical problems of slow braking response, low braking pressure control precision and the like, and can not meet the high braking performance requirement of the electric automobile.

However, the electric control failure of the electric control hydraulic brake system can occur, and the vehicle cannot be driven normally due to the electric control failure of the brake, so that a serious accident can occur. To this end, a need for redundant backup of the brake system is currently present.

The foregoing description is provided for general background information and is not admitted to be prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a can guarantee the braking under automatically controlled inefficacy, improve the automatically controlled hydraulic braking system of system reliability.

The utility model provides an automatically controlled hydraulic braking system, include:

an oil tank;

a first cylinder connected to the oil tank;

the second cylinder is connected to the oil tank and comprises a first cavity, a second cavity and a first piston, and the first cavity and the second cavity are respectively positioned on two sides of the first piston;

a drive connected to the second cylinder to drive the first piston to move in the second cylinder in a first direction or a second direction opposite to the first direction;

a liquid inlet valve;

a first fluid path connected between the first cylinder and the fluid inlet valve; and

a second fluid path disposed between the second cylinder and the fluid inlet valve, the first fluid path and the second fluid path being alternatively communicated with the fluid inlet valve, the second fluid path including a first branch connected between the first chamber and the fluid inlet valve, a second branch connected between the second chamber and the fluid inlet valve, and a third branch connected between the first branch and the second branch, the first branch being provided with a reverse control valve for communicating or disconnecting the first chamber and the fluid inlet valve, the second branch being provided with a first isolation valve for communicating or disconnecting the second chamber and the fluid inlet valve, one end of the third branch being connected between the second chamber and the first isolation valve, the third branch being provided with a first valve which allows only brake fluid to flow from the second cylinder to the fluid inlet valve, the second liquid path further comprises a fourth branch path, one end of the fourth branch path is connected between the reverse control valve and the first cavity, the other end of the fourth branch path is connected between the first valve and the second branch path, a second valve is further arranged on the fourth branch path, and the second valve only allows brake liquid to flow from the second cylinder to the liquid inlet valve.

In one embodiment, the first valve and the second valve are one-way valves.

In one embodiment, a second isolation valve is arranged on the first liquid path and used for connecting or disconnecting the first cylinder and the liquid inlet valve.

In one embodiment, the electronically controlled hydraulic brake system further includes a wheel cylinder, the wheel cylinder is connected to the fluid inlet valve, the first fluid path includes two sub fluid paths, the number of the second isolation valves is two, one second isolation valve is disposed on each sub fluid path, the fluid inlet valve includes a first fluid inlet valve, a second fluid inlet valve, a third fluid inlet valve and a fourth fluid inlet valve, the wheel cylinder includes a first wheel cylinder, a second wheel cylinder, a third wheel cylinder and a fourth wheel cylinder, a fluid inlet of the first wheel cylinder is connected to a fluid outlet of the first fluid inlet valve, a fluid inlet of the second wheel cylinder is connected to a fluid outlet of the second fluid inlet valve, a fluid inlet of the third wheel cylinder is connected to a fluid outlet of the third fluid inlet valve, a fluid inlet of the fourth wheel cylinder is connected to a fluid outlet of the fourth fluid inlet valve, one sub fluid path and the reverse control valve are connected to fluid inlets of the first fluid inlet valve and the second fluid inlet valve, and the other sub oil way and the first isolation valve are connected to the third oil inlet valve and the fourth oil inlet valve.

In one embodiment, the electronically controlled hydraulic brake system further includes a liquid outlet valve, the liquid outlet valve is connected between the wheel cylinder and the oil tank, the liquid outlet valve includes a first liquid outlet valve, a second liquid outlet valve, a third liquid outlet valve and a fourth liquid outlet valve, the first liquid outlet valve is connected between the first wheel cylinder and the oil tank, the second liquid outlet valve is connected between the second wheel cylinder and the oil tank, the third liquid outlet valve is connected between the third wheel cylinder and the oil tank, and the fourth liquid outlet valve is connected between the fourth wheel cylinder and the oil tank.

In one embodiment, the second cylinder further includes a first sealing member and a second sealing member, the first piston includes a piston portion and a piston rod, the first sealing member is disposed on the piston portion to isolate the first chamber from the second chamber, the second sealing member is disposed on an end of a cylinder barrel of the second cylinder away from the first chamber, the second sealing member divides the second chamber into a first portion and a second portion, the first portion is located between the first chamber and the second portion, a passage is disposed on the piston rod, the first piston is movable to a position where the passage communicates the first portion with the second portion, the intake valve is connected to the first portion, and the oil tank is connected to the second portion.

In one embodiment, the passage is a slot opened on the piston rod, and the slot is opened at the position adjacent to the piston rod and the piston.

In one embodiment, the oil tank is communicated with the first chamber and the second chamber of the second cylinder, respectively, and a third valve is provided between the oil tank and the first chamber, and the third valve only allows brake fluid to enter the first chamber from the oil tank.

In one embodiment, the electronic control hydraulic system further includes an input device, the first cylinder includes a second piston and a third piston, the first cylinder is divided into a third cavity and a fourth cavity by the second piston, the input device is connected to the third piston, the third piston is disposed in the fourth cavity, the electronic control hydraulic brake system further includes a pedal simulation element disposed at the input device, the pedal simulation element is connected to the third cavity of the first cylinder, and pressure is built up on the pedal simulation element when the third cavity outputs oil.

In one embodiment, the electrically controlled hydraulic brake system further includes a test valve connected between the oil tank and the fourth chamber of the first cylinder for communicating or disconnecting the oil tank and the fourth chamber of the first cylinder.

The utility model discloses an automatically controlled hydraulic braking system, through the design of oil circuit, can realize three kinds of braking modes of first braking mode, second braking mode and mechanical backup mode, can satisfy the braking demand when automatically controlled became invalid, system reliability is higher, can satisfy multiple different braking force demands again, can adapt to the requirement to braking system in the current intelligent driving; and the system has high integration level, light weight, relatively low cost and obvious product advantages.

Drawings

Fig. 1 is a state diagram of a mechanical backup mode of an electric control hydraulic brake system according to an embodiment of the present invention.

Fig. 2 is a structural diagram illustrating a state of a second cylinder of the electro-hydraulic brake system of fig. 1.

Fig. 3 is a structural diagram illustrating another state of a second cylinder of the electrically controlled hydraulic brake system of fig. 1.

FIG. 4 is a state diagram of a first braking mode of the electro-hydraulic brake system of FIG. 1.

FIG. 5 is a state diagram of a second braking mode of the electro-hydraulic brake system of FIG. 1.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

Fig. 1 is a schematic structural diagram of an electric control hydraulic braking system according to an embodiment of the present invention. The utility model discloses an automatically controlled hydraulic braking system of embodiment includes input device 11, oil tank 12, first jar 13, second jar 15, driving piece, feed liquor valve, wheel cylinder, first fluid circuit and second fluid circuit 25. The first cylinder 13 and the second cylinder 15 are connected to the oil tank 12, respectively. The first liquid path is connected between the first cylinder 13 and the liquid inlet valve, the second liquid path 25 is arranged between the second cylinder 15 and the liquid inlet valve, the first liquid path and the second liquid path 25 can be alternatively communicated with the liquid inlet valve, and oil enters the wheel cylinder through the liquid inlet valve to brake the wheel. The second cylinder 15 includes a first chamber 152, a second chamber 154, and a first piston 157, and the first chamber 152 and the second chamber 154 are connected to both sides of the first piston 157, respectively. The wheel cylinder is connected with the liquid inlet valve. The second fluid path 25 includes a first branch 252 connected between the first chamber 152 of the second cylinder 15 and the intake valve, a second branch 254 located between the second chamber 154 and the intake valve, and a third branch 256 connected between the first branch 252 and the second branch 254. The first branch 252 is provided with a reverse control valve 29, and the reverse control valve 29 is used for connecting or disconnecting the first chamber 152 with the liquid inlet valve. The second branch 254 is provided with a first isolation valve 27, and the first isolation valve 27 is used for connecting or disconnecting the second chamber 154 and the liquid inlet valve. One end of the third branch 256 is connected between the second chamber 154 and the first isolation valve 27. The drive member is connected to the second cylinder 15 to drive the first piston 157 to move within the second cylinder 15.

In this embodiment, the third branch 256 is provided with a first valve 258, and the first valve 258 only allows the brake fluid to flow from the second cylinder 15 to the inlet valve. Specifically, the first valve 258 is a one-way valve, and it is understood that the first valve 258 may be other types of valves such as a two-position two-way solenoid valve, and the solenoid valve may be closed or opened when needed. By arranging the first valve 258 and the first isolating valve 27, when one of the first valve 258 and the first isolating valve 27 is leaked, the pressure can not be built, the other one of the first valve 258 and the first isolating valve 27 can still build the pressure, brake fluid is provided for two wheel cylinders, effective braking is ensured, and potential safety hazard during braking is eliminated.

In this embodiment, second fluid pathway 25 further includes a fourth branch 259, with one end of fourth branch 259 connected between reverse control valve 29 and first chamber 152 and the other end connected between first valve 258 and second branch 254. A second valve 260 is also provided in the fourth branch 259, the second valve 260 allowing only brake fluid to flow from the second cylinder 15 to the inlet valve. Specifically, the second valve 260 is a one-way valve, and it will be appreciated that the first valve 258 may be other types of valves such as a two-position, two-way solenoid valve that can be closed or opened as desired. By providing the second valve 260, that is, the second valve 260 and the reverse control valve 29 are connected in parallel, the apertures of the reverse control valve 29 and the second valve 260 can be designed to be relatively small, the existing electromagnetic valve can be used, and the electromagnetic valve with a larger aperture and a larger coil do not need to be additionally developed, so that the manufacturing cost is reduced, and the development period is shortened.

In this embodiment, the first liquid path is provided with a second isolation valve 2, and the second isolation valve 2 is used for connecting or disconnecting the first cylinder 13 and the liquid inlet valve.

Specifically, the first isolation valve 27, the second isolation valve 2, and the reverse control valve 29 are all switching valves, and may be specifically two-position two-way solenoid valves, and the left position is communicated to open the corresponding first isolation valve 27, second isolation valve 2, and reverse control valve 29, and the right position is disconnected to close the corresponding first isolation valve 27, second isolation valve 2, and reverse control valve 29.

In this embodiment, referring to fig. 2, the second cylinder 15 further includes a first sealing member and a second sealing member, the first piston 157 includes a piston portion and a piston rod, the first sealing member is disposed on the piston portion to isolate the first chamber 152 from the second chamber 154, the second sealing member is disposed on an end of the cylinder away from the first chamber 152 to prevent brake fluid in the second chamber 154 from leaking, the second sealing member divides the second chamber 154 into a first portion and a second portion, and the first portion is located between the first chamber 152 and the second portion. The piston rod is provided with a passage, the first piston 157 is movable to a position where the passage communicates the first portion and the second portion (in this embodiment, the right position of the first piston 157), the intake valve is connected to the first portion of the second chamber 154, and the oil tank 12 is connected to the second portion of the second chamber 152. In this embodiment, the channel is a slot formed in the piston rod, and the slot is formed in the piston rod adjacent to the piston. It will be appreciated that the passage may also be a through bore opening in the interior of the first piston 157.

Referring to fig. 3, when the input device 11 is repeatedly and continuously stepped on, the first piston 157 reciprocates, so that brake fluid is supplied from the oil tank 12 into the first chamber 152, resulting in increased braking in the closed chamber below the second isolation valve 2, and when the first piston 157 is located at the right position, the first portion and the second portion are communicated, so that the brake fluid in the closed chamber below the second isolation valve 2 and the second chamber 154 can flow out and return to the oil tank 12, thereby achieving pressure relief.

In the present embodiment, the input device 11 is embodied as a brake pedal.

In this embodiment, the first cylinder 13 includes a second piston 130 and a third piston 131, the first cylinder 13 is divided into a third chamber 132 and a fourth chamber 134 by the second piston 130, the input device 11 is connected to the third piston 131, and the third piston 131 is disposed in the fourth chamber 134, so that when the driver steps on the input device, the third piston 131 is pushed to move in the first cylinder 13, so that the oil entering the first cylinder 13 from the oil tank 12 is output to the first fluid path from the third chamber 132 and the fourth chamber 134.

Specifically, the first oil path includes two sub oil paths, the number of the second isolation valves 2 is two, and each sub oil path is provided with one second isolation valve 2. The oil inlet valve comprises a first oil inlet valve 2, a second oil inlet valve 3, a third oil inlet valve 4 and a fourth oil inlet valve 5, the wheel cylinders comprise a first wheel cylinder 2, a second wheel cylinder 3, a third wheel cylinder 4 and a fourth wheel cylinder 5, a liquid inlet of the first wheel cylinder 2 is connected to a liquid outlet of the first oil inlet valve 2, a liquid inlet of the second wheel cylinder 3 is connected to a liquid outlet of the second oil inlet valve 3, a liquid inlet of the third wheel cylinder 4 is connected to a liquid outlet of the third oil inlet valve 4, and a liquid inlet of the fourth wheel cylinder 5 is connected to a liquid outlet of the fourth oil inlet valve 5. One of the sub oil passages and the reverse control valve 29 is connected to the liquid inlets of the first oil inlet valve 2 and the second oil inlet valve 3, and the other sub oil passage and the first isolation valve 27 are connected to the third oil inlet valve 4 and the fourth oil inlet valve 5. Specifically, the first wheel cylinder 2, the second wheel cylinder 3, the third wheel cylinder 4, and the fourth wheel cylinder 5 are a front-left wheel cylinder, a rear-right wheel cylinder, a front-right wheel cylinder, and a rear-left wheel cylinder.

Specifically, the electronically controlled hydraulic brake system further includes a liquid outlet valve 32, and the liquid outlet valve 32 is connected between the wheel cylinder and the oil tank 12 to return oil in the wheel cylinder. More specifically, the liquid valves 32 include a first liquid valve 322, a second liquid valve 3, a third liquid valve 324 and a fourth liquid valve 325, the first liquid valve 322 is connected between the first wheel cylinder 2 and the oil tank 12, the second liquid valve 3 is connected between the second wheel cylinder 3 and the oil tank 12, the third liquid valve 324 is connected between the third wheel cylinder 4 and the oil tank 12, and the fourth liquid valve 325 is connected between the fourth wheel cylinder 5 and the oil tank 12.

In this embodiment, the oil tank 12 communicates with the first chamber 152 and the second chamber 154 of the second cylinder 15, respectively. Specifically, a third valve 33 is provided between the tank 12 and the first chamber 152, and the third valve 33 allows only brake fluid to enter the first chamber 152 from the tank 12. Specifically, the third valve 33 may be a one-way valve. Normally, the brake fluid in the oil tank 12 does not enter the second cylinder 15, and the third valve 33 is provided to prevent the brake fluid in the oil tank 12 from entering the second cylinder 15 at will.

In this embodiment, the driving member may be a motor, and the motor is started to rotate to drive the first piston 157 of the second cylinder 15 to move back and forth under the action of a transmission mechanism, for example, a lead screw and nut mechanism. Specifically, the electronically controlled hydraulic brake system further includes a motor position sensor to detect the position of the driver and, in turn, the position of the first piston 157 of the second cylinder 15.

In this embodiment, the electronically controlled hydraulic brake system further includes a test valve 35, and the test valve 35 is connected between the oil tank 12 and the fourth chamber 134 of the first cylinder 13 for connecting or disconnecting the oil tank 12 and the fourth chamber 134 of the first cylinder 13. Specifically, the test valve 35 may be a two-position, two-way valve.

In the present embodiment, the electronically controlled hydraulic brake system further includes a control module (e.g. an ECU (electronic control unit) (not shown)) and a pedal stroke detecting element 40, wherein the pedal stroke detecting element 40 is connected to the control module and the input device 11, and is used for detecting the stroke of the input device 11 so as to know the braking force demand of the driver and transmit the braking force demand to the control module.

In this embodiment, the electronically controlled hydraulic brake system further includes a pressure sensing element coupled to the third chamber 132 of the first cylinder 13 to sense the pressure in the third chamber 132, the pressure sensing element being coupled to the control module.

In the present embodiment, the electronically controlled hydraulic brake system further includes a pedal simulation element 43 disposed at the input device 11, the pedal simulation element 43 is connected to the third chamber 132 of the first cylinder 13, when the third chamber 132 outputs oil, pressure is built on the pedal simulation element 43, and the pressure on the pedal simulation element 43 causes a driver stepping on the input device 11 to feel resistance, thereby realizing simulation of the brake pedal feel. An analog control valve 45 may also be provided between the pedal simulating member 43 and the first cylinder 13 to communicate or disconnect the first cylinder 13 and the pedal simulating member 43 to simulate or not simulate a brake pedal feel.

In this document, each of the control valves, the test valve, the liquid inlet valve, the liquid outlet valve, the selection valve and the pressure release valve can be an electric control valve, and the state of the electric control valve is controlled by the power on or power off of the electric control valve through an instruction of the control module. The liquid inlet valve is a normally closed valve, is opened for communication when power is lost, and is closed for disconnection when power is obtained. The second isolation valve 2 is communicated with the liquid inlet valve and the first cylinder 13 when power is on, and is communicated with the liquid inlet valve and the first cylinder 13 when power is off.

In this embodiment, the electronically controlled hydraulic brake system includes a first braking mode, a second braking mode, and a mechanical backup mode. In the case of electrical control failure, all the electromagnetic valves are in a non-powered state, and at this time, a mechanical backup mode is adopted, please refer to fig. 1, the reverse control valve 29 and the first isolation valve 27 are both closed, the second isolation valve 2 is opened to enable the first cylinder 13 to be communicated with the liquid inlet valve through the first liquid path, and the second liquid path 25 is disconnected, when the driver steps on the input device 11, the first liquid path is communicated with the liquid inlet valve, and the brake fluid flows from the third chamber 132 and the fourth chamber 134 of the first cylinder 13 to the liquid inlet valve through the first liquid path, and then flows to the wheel cylinder for braking. After the braking effect is achieved, the input device 11 is released and the brake fluid is returned from the original path to the first cylinder 13.

In the first brake mode, referring to fig. 4, the second isolation valve 2 is closed, the first cylinder 13 is disconnected from the fluid inlet valve, the reverse control valve 29 and the first isolation valve 27 are both opened, the second cylinder 15 is communicated with the fluid inlet valve, when the driver depresses the input device 11, the driver moves the first piston 157 in the first direction (leftward movement in the drawing), the brake fluid in the first chamber 152 enters the first fluid inlet valve 2 and the second fluid inlet valve 3 through the reverse control valve 29 or the reverse control valve 29, the second valve 260 and the first valve 258, and then enters the first wheel cylinder 2 and the second wheel cylinder 3, the brake fluid also enters the third fluid inlet valve 4 and the fourth fluid inlet valve 5 through the second valve 260 and the first isolation valve 27, and then enters the fourth wheel cylinder 4 and the fourth wheel cylinder 5, and a part of the brake fluid enters the second chamber 154 through the second valve 260 for oil replenishment. After the braking effect is achieved, the input device 11 is released and the brake fluid is returned from the original path to the second cylinder 15.

In the second brake mode, referring to fig. 5, the second isolation valve 2 is closed, the first cylinder 13 is disconnected from the fluid inlet valve, the reverse control valve 29 is closed, the first isolation valve 27 is opened, the second cylinder 15 is communicated with the fluid inlet valve, when the driver depresses the input device 11, the driving member moves the first piston in a second direction (rightward in the drawing) opposite to the first direction, the brake fluid in the second chamber 154 enters the third fluid inlet valve 4 and the fourth fluid inlet valve 5 through the first isolation valve 27, and then enters the fourth cylinder 4 and the fourth cylinder 5, and the brake fluid also enters the first fluid inlet valve 2 and the second fluid inlet valve 3 through the first valve 258, and then enters the first wheel cylinder 2 and the second wheel cylinder 3. In this mode, after the pressure in the wheel cylinder is increased by moving the first piston 157 leftward in the first brake mode, the pressure in the wheel cylinder is increased by controlling the first piston 157 to move rightward, so that the braking force can be further increased, and a larger braking force demand can be met. After the braking effect is achieved, the input device 11 is released and the brake fluid is returned from the original path to the second cylinder 15.

In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being "formed on," "disposed on" or "located on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there are no intervening elements present.

In this document, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms can be understood in a specific case to those of ordinary skill in the art.

In this document, the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", and the like indicate the orientation or weight relationship based on the orientation or weight relationship shown in the drawings, only for the sake of clarity and convenience of description of the technical solution, and thus, should not be construed as limiting the present invention.

As used herein, the ordinal adjectives "first", "second", etc., used to describe an element are merely to distinguish between similar elements and do not imply that the elements so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

As used herein, the meaning of "a plurality" or "a plurality" is two or more unless otherwise specified.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, including not only those elements listed, but also other elements not expressly listed.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An electronically controlled hydraulic brake system, comprising:

a fuel tank (12);

a first cylinder (13) connected to the oil tank (12);

a second cylinder (15) connected to the oil tank (12), the second cylinder (15) comprising a first chamber (152), a second chamber (154) and a first piston (157), the first chamber (152) and the second chamber (154) being located on either side of the first piston (157), respectively;

a drive (17) connected to the second cylinder (15) to drive the first piston (157) to move in the second cylinder (15) in a first direction or a second direction opposite to the first direction;

a liquid inlet valve (19);

a first fluid path (23) connected between the first cylinder (13) and the fluid inlet valve (19); and

a second fluid path (25) provided between the second cylinder (15) and the fluid inlet valve (19), the first fluid path (23) and the second fluid path (25) being alternatively communicated with the fluid inlet valve (19), the second fluid path (25) including a first branch (252) connected between the first chamber (152) and the fluid inlet valve (19), a second branch (254) connected between the second chamber (154) and the fluid inlet valve (19), and a third branch (256) connected between the first branch (252) and the second branch (254), the first branch (252) being provided with a reverse control valve (29), the reverse control valve (29) being for communicating or disconnecting the first chamber (152) and the fluid inlet valve (19), the second branch (254) being provided with a first isolation valve (27), the first isolation valve (27) being for communicating or disconnecting the second chamber (154) and the fluid inlet valve (19), one end of the third branch (256) is connected between the second chamber (154) and the first isolation valve (27), a first valve (258) is arranged on the third branch (256), the first valve (258) only allows the brake fluid to flow from the second cylinder (15) to the fluid inlet valve (19), the second fluid path (25) further comprises a fourth branch (259), one end of the fourth branch (259) is connected between the reverse control valve (29) and the first chamber (152), the other end of the fourth branch is connected between the first valve (258) and the second branch (254), a second valve (260) is further arranged on the fourth branch (259), and the second valve (260) only allows the brake fluid to flow from the second cylinder (15) to the fluid inlet valve (19).

2. An electrically controlled hydraulic brake system according to claim 1, characterized in that the first valve (258) and the second valve (260) are one-way valves.

3. An electrically controlled hydraulic brake system according to claim 1, characterized in that a second isolating valve (232) is provided on the first fluid path (23), the second isolating valve (232) being adapted to connect or disconnect the first cylinder (13) to the fluid inlet valve (19).

4. The electric control hydraulic brake system according to claim 3, further comprising a wheel cylinder (21), wherein the wheel cylinder (21) is connected to the fluid intake valve (19), the first fluid path (23) includes two sub fluid paths, the number of the second isolation valves (232) is two, one second isolation valve (232) is provided on each sub fluid path, the fluid intake valve (19) includes a first fluid intake valve (192), a second fluid intake valve (193), a third fluid intake valve (194), and a fourth fluid intake valve (195), the wheel cylinder (21) includes a first wheel cylinder (212), a second wheel cylinder (213), a third wheel cylinder (214), and a fourth wheel cylinder (215), a fluid inlet of the first wheel cylinder (212) is connected to a fluid outlet of the first fluid intake valve (192), a fluid inlet of the second wheel cylinder (213) is connected to a fluid outlet of the second fluid intake valve (193), an inlet of the third wheel cylinder (214) is connected to an outlet of the third oil inlet valve (194), an inlet of the fourth wheel cylinder (215) is connected to an outlet of the fourth oil inlet valve (195), one sub-oil path and the reverse control valve (29) are connected to inlets of the first oil inlet valve (192) and the second oil inlet valve (193), and the other sub-oil path and the first isolation valve (27) are connected to the third oil inlet valve (194) and the fourth oil inlet valve (195).

5. An electrically controlled hydraulic brake system according to claim 4, further comprising fluid outlet valves (32), the fluid outlet valves (32) being connected between the wheel cylinders (21) and the tank (12), the fluid outlet valves (32) including a first fluid outlet valve (322), a second fluid outlet valve (323), a third fluid outlet valve (324), and a fourth fluid outlet valve (325), the first fluid outlet valve (322) being connected between the first wheel cylinder (212) and the tank (12), the second fluid outlet valve (323) being connected between the second wheel cylinder (213) and the tank (12), the third fluid outlet valve (324) being connected between the third wheel cylinder (214) and the tank (12), the fourth fluid outlet valve (325) being connected between the fourth wheel cylinder (215) and the tank (12).

6. An electrically controlled hydraulic brake system according to claim 1, characterized in that the second cylinder (15) further comprises a first seal (159) and a second seal (161), the first piston (157) comprising a piston portion and a piston rod, the first seal (159) being provided on the piston portion to isolate the first chamber (152) from the second chamber (154), the second seal (161) being provided on the cylinder barrel of the second cylinder (15) at an end remote from the first chamber (152), the second seal (161) dividing the second chamber (154) into a first portion and a second portion, the first portion being located between the first chamber (152) and the second portion, the piston rod being provided with a passage, the first piston (157) being movable to a position in which the passage communicates the first portion with the second portion, the intake valve (19) is connected to the first part and the tank (12) is connected to the second part.

7. An electro-hydraulic brake system according to claim 6, wherein the passage is a slot (163) opening in the piston rod, the slot (163) opening adjacent the piston rod and the piston.

8. An electrically controlled hydraulic brake system according to claim 1, characterised in that the tank (12) communicates with the first chamber (152) and the second chamber (154) of the second cylinder (15), respectively, and a third valve (33) is provided between the tank (12) and the first chamber (152), the third valve (33) allowing only brake fluid to pass from the tank (12) into the first chamber (152).

9. An electro-hydraulic brake system according to claim 1, further comprising an input device (11), wherein the first cylinder (13) includes a second piston (130) and a third piston (131), wherein the first cylinder (13) is partitioned into a third chamber (132) and a fourth chamber (134) by the second piston (130), wherein the input device (11) is connected to the third piston (131), wherein the third piston (131) is provided in the fourth chamber (134), and wherein the electro-hydraulic brake system further comprises a pedal simulation element (43) provided at the input device (11), wherein the pedal simulation element (43) is connected to the third chamber (132) of the first cylinder (13), and wherein the pedal simulation element (43) is pressurized by the pedal simulation element (43) when the third chamber (132) outputs oil.

10. An electrically controlled hydraulic brake system according to claim 9, further comprising a test valve (38), said test valve (38) being connected between said tank (12) and said fourth chamber (134) of said first cylinder (13) for connecting or disconnecting said tank (12) and said fourth chamber (134) of said first cylinder (13).