Hydraulic braking system of electric control vehicle

Abstract

The invention discloses a hydraulic braking system of an electric control vehicle in the technical field of hydraulic braking, and aims to solve the problems of small braking flow and slow response of a braking system in the prior art. The method includes the steps that a traditional brake system directly utilizing a pump body to charge energy for a brake is abandoned, a brake energy accumulator is arranged to charge oil for the brake, and the brake energy accumulator is large in instantaneous flow and high in pressure, can drive the brake to conduct effective braking in a short time and further has the advantage of being high in response speed; an energy storage control valve set is further arranged for the brake energy accumulator and used for supplementing hydraulic oil for the brake energy accumulator in time, and it is guaranteed that the brake energy accumulator is repeatedly used. Through introduction of the energy storage control valve group, the brake energy accumulator has an automatic liquid filling function and automatically keeps working pressure, the failure rate of the brake is reduced, the automatic liquid filling function is achieved through the energy storage control valve group, and the energy storage control valve group achieving the function based on the hydraulic control rule has higher reliability compared with a pure electric control component.

Description

Technical Field

[0001] The invention relates to a hydraulic brake system of an electronically controlled vehicle, belonging to the technical field of hydraulic brakes. Background Art

[0002] In the existing braking system design, a significant technical challenge is the relatively slow braking response speed and small braking flow. This directly affects the vehicle's safety performance and responsiveness in emergency braking situations. Specifically, the slow braking response speed means that there is a long time delay between the driver applying the braking force and the vehicle actually starting to slow down, which may increase the braking distance at high speeds or in sudden emergencies, thereby threatening road safety. On the other hand, the small braking flow limits the hydraulic or pneumatic energy that the braking system can transmit per unit time, which in turn affects the efficiency of braking force generation and braking stability. Summary of the invention

[0003] The purpose of the present application is to overcome the deficiencies in the prior art and to provide a hydraulic brake system for an electronically controlled vehicle with fast braking response speed, large flow rate and high reliability.

[0004] In order to achieve the above objectives, this application is implemented by adopting the following technical solutions: The present application provides a hydraulic brake system for an electronically controlled vehicle, comprising: An oil tank and a pump body for pumping the hydraulic oil in the oil tank; a normally closed electrically controlled brake valve and a brake in communication with the electrically controlled brake valve; An energy storage control valve group and a brake accumulator, wherein the energy storage control valve group is communicated with the pump body and the brake accumulator respectively, and the electrically controlled brake valve is communicated with the brake accumulator; When the pressure of the brake accumulator does not exceed a first threshold, the energy storage control valve group conducts between the pump body and the brake accumulator, and the pump body fills the brake accumulator with oil; When the pressure of the brake accumulator exceeds a first threshold, the energy storage control valve group reduces the oil filling flow rate; The electrically controlled brake valve conducts flow between the brake accumulator and the brake in response to a braking command, and the brake accumulator outputs hydraulic oil to drive the brake to perform a vehicle braking operation.

[0005] In some embodiments of the present application, the energy storage control valve group includes a first valve and a second valve; The valve core of the first valve has a first valve first position and a first valve second position, and the flow rate of the valve core of the first valve when it is in the first valve first position is smaller than the flow rate of the valve core of the first valve when it is in the first valve second position; The valve core of the second valve has a second valve first position and a second valve second position. When the valve core of the second valve is in the second valve first position, it is an open circuit. When the valve core of the second valve is in the second valve second position, it is a pilot valve. The oil inlet of the first valve is connected to the pump body, and the oil outlet of the first valve is connected to the brake accumulator through the main oil supply line; the first valve includes a first pressure oil port and a second pressure oil port, both for controlling its valve core, and the first pressure oil port is connected to the pump body; The oil inlet of the second valve is connected to the main oil supply circuit, and the oil outlet of the second valve is connected to the second pressure oil port through the first pilot oil circuit; The second valve comprises a third pressure oil port connected to the main oil supply line, and the third pressure oil port is used to control the valve core of the second valve; When the pressure of the brake accumulator does not exceed the first threshold value, the pressure of the third pressure oil port is lower than the first threshold value, the valve core of the second valve is located at the second valve second position, and the hydraulic oil of the main oil supply circuit is introduced into the second pressure oil port through the second valve and the first pilot oil circuit in sequence; the pressure difference between the first pressure oil port and the second pressure oil port does not exceed the second threshold value, the valve core of the first valve is located at the second valve second position, and the pump body fills the brake accumulator with oil through the first valve and the main oil supply circuit in sequence; When the pressure of the brake accumulator exceeds the first threshold value, the pressure of the third pressure oil port reaches the first threshold value, and the pressure of the third pressure oil port drives the valve core of the second valve to switch to the first position of the second valve, and the second valve forms a short circuit; the pressure difference between the first pressure oil port and the second pressure oil port exceeds the second threshold value, and the pressure difference drives the valve core of the first valve to switch to the first position of the first valve, and the pump body fills the brake accumulator with oil through the first valve and the main oil supply circuit in turn.

[0006] In some embodiments of the present application, the first valve includes a first spring for controlling a valve core thereof; When the pressure difference between the first pressure oil port and the second pressure oil port does not exceed a second threshold value, the sum of the pressure of the second pressure oil port and the elastic force of the first spring is not lower than the pressure of the first pressure oil port, and the valve core of the first valve is located at the second position of the first valve; When the pressure difference between the first pressure oil port and the second pressure oil port exceeds a second threshold value, the sum of the pressure of the second pressure oil port and the elastic force of the first spring is lower than the pressure of the first pressure oil port, and the pressure difference drives the valve core of the first valve to switch to the first valve first position.

[0007] In some embodiments of the present application, the second valve includes a second spring for controlling a valve core thereof; When the pressure of the brake accumulator does not exceed the first threshold value, the pressure of the third pressure oil port does not exceed the elastic force of the second spring, and the valve core of the second valve is located at the second valve second position; When the pressure of the brake accumulator exceeds the first threshold, the pressure of the third pressure oil port exceeds the elastic force of the second spring, and the pressure difference drives the valve core of the second valve to switch to the second valve first position.

[0008] In some embodiments of the present application, it further includes an accumulator 4, a parking solenoid valve, and a parking brake connected to an oil outlet of the parking solenoid valve; The pump body fills the accumulator 4 with oil through the main oil supply line, and the accumulator 4 is connected to the oil inlet of the parking solenoid valve; When the parking solenoid valve is not powered, its oil inlet is normally closed, and the parking brake is in a parking state; The parking solenoid valve is turned on when energized, and the accumulator 4 charges the parking brake with oil through the parking solenoid valve, and the parking brake releases the parking state.

[0009] In some embodiments of the present application, a manual pump is further included, wherein the oil inlet of the manual pump is connected to the oil tank, and the oil outlet is connected to the parking brake; the manual pump is used to manually pump oil for the parking brake to release the parking brake.

[0010] In some embodiments of the present application, a relief valve is further included, wherein an oil inlet of the relief valve is connected to an oil path between the first valve and the pump body, and an oil outlet of the relief valve is connected to the oil tank; When the brake accumulator is full, excess hydraulic oil flows back from the overflow valve to the oil tank.

[0011] In some embodiments of the present application, the electrically controlled brake valve includes a relay valve and a pilot control valve, both of which are normally closed, the brake accumulator is respectively connected to the oil inlet of the pilot control valve and the oil inlet of the relay valve, and the oil outlet of the pilot control valve is connected to the pilot oil port of the relay valve; in response to the braking command, the pilot control valve is turned on, the oil outlet of the pilot control valve injects hydraulic oil into the pilot oil port of the relay valve, the relay valve is turned on, and the brake accumulator outputs hydraulic oil to the brake accumulator through the relay valve.

[0012] In some embodiments of the present application, it further includes a compensation accumulator communicated with the brake and a pressure sensor for detecting the pressure of the brake accumulator, wherein the compensation accumulator is communicated with the brake accumulator; In response to a pressure drop in the brake accumulator, the compensating accumulator performs pressure compensation for the brake accumulator.

[0013] In some embodiments of the present application, a pressure-compensating solenoid valve and a pressure sensor 8 for detecting the pressure of the compensating accumulator are also included, the oil inlet of the pressure-compensating solenoid valve is connected to the pump body, the oil outlet is connected to the compensating accumulator, and the pressure-compensating solenoid valve is normally closed; in response to the pressure of the compensating accumulator being lower than a third threshold value, the pressure-compensating solenoid valve is turned on, and the pump body compensates the pressure of the compensating accumulator.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The hydraulic braking system of an electronically controlled vehicle provided in the present application abandons the traditional braking system that directly uses a pump body to charge the brake, and instead configures a brake accumulator to charge the brake with oil. The brake accumulator has a large instantaneous flow and high pressure, which can drive the brake to effectively brake in a short time, and also has the advantage of high response speed; the present application also configures an energy storage control valve group for the brake accumulator, and the energy storage control valve group is used to replenish the hydraulic oil of the brake accumulator in time, and switch the filling flow according to the first threshold value to ensure the life and reuse performance of the brake accumulator; the introduction of the energy storage control valve group enables the brake accumulator to have a good autonomous filling function, maintain the working pressure by itself, reduce the failure rate of the brake, and rely on the energy storage control valve group to realize the autonomous filling function. The energy storage control valve group that realizes the function based on the hydraulic control law has higher reliability than pure electronic control components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 Schematic diagram of the hydraulic oil circuit structure of the hydraulic brake system of an electronically controlled vehicle provided in this embodiment; Figure 2 yes Figure 1 Schematic diagram of the hydraulic oil circuit structure after the middle brake valve group is enlarged; Figure 3 is with Figure 2 Schematic diagram of pilot pressure transmission direction when the valve core of the corresponding first valve is in the first position of the first valve Figure 4 is with Figure 2 A schematic diagram of the flow direction of hydraulic oil for large-flow filling of the brake accumulator when the valve core of the corresponding first valve is in the first valve first position; Figure 5 is with Figure 2 A schematic diagram of the pilot pressure transmission direction when the valve core of the corresponding first valve is about to switch from the first valve first position to the first valve second position; Figure 6 is with Figure 2 A schematic diagram of the flow direction of hydraulic oil for small flow filling of the brake accumulator when the valve core of the corresponding first valve is in the second position of the first valve; Figure 7 is with Figure 2 A schematic diagram of the pilot pressure transmission direction when the valve core of the corresponding first valve is about to switch from the second position of the first valve to the first position of the first valve; In the figure: 1, oil tank; 2, pump body; 3, accumulator 1; 4, accumulator 2; 5, accumulator 3; 6, accumulator 4; 7, brake valve group; 8, relay valve 1; 9, relay valve 2; 10, relay valve 3; 11. Pressure sensor 1; 12. Pressure sensor 2; 13. Pressure sensor 3; 14. Pressure sensor 4; 15. Pressure sensor 5; 16. Pressure sensor 6; 17. Pressure sensor 7; 26. Pressure sensor 8; 18. Left front brake of axle 1; 19. Right front brake of axle 1; 20. Left front brake of axle 2; 21. Right front brake of axle 2; 22. Left front brake of axle 3; 23. Right front brake of axle 3; 24. Parking brake; 25. Compensation accumulator; 27. Compensation solenoid valve; 701, energy storage control valve group; 702, manual pump; 703, overflow valve; 704, first electro-hydraulic proportional brake valve; 705, second electro-hydraulic proportional brake valve; 706, parking solenoid valve; 707, parking pressure reducing valve; 701a, the first valve; 701b, the second valve; 701c, the third valve; 701d, the first pressure oil port; 701e, the second pressure oil port; 701f, the first valve in the first position; 701g, the first valve in the second position; 701h, the main oil supply circuit; 701i, the third pressure oil port; 701j, the second valve in the first position; 701k, the second valve in the second position; 701l, the first pilot oil circuit; 701m, the return oil circuit. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of this application / this application to clearly and completely describe the technical solutions in the embodiments of this application / this application. Obviously, the described embodiments are only part of the embodiments of this application / this application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the application / this application and its application or use. Embodiment 1

[0018] This embodiment provides a hydraulic brake system for an electronically controlled vehicle to solve the problems of small brake flow and slow response of the brake system in the prior art.

[0019] refer to Figure 1The hydraulic brake system of the electronically controlled vehicle provided in this embodiment includes: An oil tank 1 and a pump body 2 for pumping hydraulic oil in the oil tank 1; A normally closed electric control brake valve and a brake connected to the electric control brake valve. When the electric control brake valve is opened, hydraulic oil is injected into the brake through the electric control brake valve, and the brake performs a braking action by getting oil; The energy storage control valve group 701 and the brake accumulator are connected to the pump body 2 and the brake accumulator respectively. The energy storage control valve group 701 is used to control the oil supply from the pump body 2 to the brake accumulator. The electric control brake valve is connected to the brake accumulator. The brake accumulator is used to inject hydraulic oil into the brake through the electric control brake valve. When the pressure of the brake accumulator does not exceed the first threshold, the brake accumulator needs to be supplemented with hydraulic oil to cope with the large flow hydraulic oil demand during brake application, so the energy storage control valve group 701 conducts the pump body 2 and the brake accumulator, and the pump body 2 charges the brake accumulator with oil; When the pressure of the brake accumulator exceeds the first threshold value, the pressure of the brake accumulator meets the large flow hydraulic oil demand during brake braking. The brake accumulator needs to be filled with a small flow of oil to reduce the system pressure to prevent damage to the brake accumulator. The energy storage control valve group 701 reduces the oil filling flow of the pump body 2 to the brake accumulator or stops filling the oil. This process includes but is not limited to: the energy storage control valve group 701 returns part of the hydraulic oil injected by the pump body 2 to the oil tank 1 or the oil inlet of the energy storage control valve group 701 is closed.

[0020] The small flow rate oil filling process of the brake accumulator will continue until the brake accumulator is full, or until the pump body 2 stops pumping oil.

[0021] The electronically controlled brake valve connects the brake accumulator and the brake in response to the braking command. The brake accumulator outputs hydraulic oil to drive the brake to perform vehicle braking operations. The pressure of the brake accumulator is simultaneously restored to below the first threshold. The energy storage control valve group 701 connects the pump body 2 and the brake accumulator. The pump body 2 charges the brake accumulator to accumulate hydraulic oil for the next braking.

[0022] The energy storage control valve group 701 can be implemented in other forms known in the art, such as a valve group that can realize the functions mentioned above after combining multiple valves, or even more other known forms, which will not be repeated here.

[0023] Traditional braking systems directly use a pump body to inject hydraulic oil into the brake to achieve braking. The pump body's pumping flow is limited, resulting in low flow and slow response of the brake in a short period of time when the vehicle performs a braking operation. In emergency braking situations, the brakes may fail because the pump source system cannot provide sufficient pressure in time, greatly increasing the risk of a vehicle collision.

[0024] The hydraulic brake system of the electronically controlled vehicle provided in the present embodiment abandons the traditional brake system that directly uses the pump body to charge the brake, and instead configures a brake accumulator to charge the brake. The brake accumulator has a large instantaneous flow and high pressure, which can drive the brake to brake effectively in a short time, and also has the advantage of high response speed. The present embodiment also configures an energy storage control valve group 701 for the brake accumulator. The energy storage control valve group 701 is used to replenish the hydraulic oil for the brake accumulator in time, and switch the small flow rate to charge the oil according to the first threshold value to ensure the reuse and life of the brake accumulator. The introduction of the energy storage control valve group 701 enables the brake accumulator to have an autonomous filling function, maintain the working pressure by itself, reduce the failure rate of the brake, and rely on the energy storage control valve group 701 to realize the autonomous filling function. The energy storage control valve group 701 that realizes the function based on the hydraulic control law has higher reliability than pure electronic control components.

[0025] The first threshold value may be established according to a set working pressure of the brake accumulator. Embodiment 2

[0026] This embodiment provides a hydraulic brake system for an electronically controlled vehicle. This embodiment is optimized on the basis of the first embodiment to improve the technical effect and refine the technical solution. For details not fully described in this embodiment, please refer to the first embodiment.

[0027] Embodiment 1 mentions that the energy storage control valve group 701 realizes the autonomous filling function of the brake accumulator based on the hydraulic control law, which is more reliable than the pure electronic control components in principle. Figure 2 The energy storage control valve group 701 includes a first valve 701a and a second valve 701b. The first valve 701a and the second valve 701b use different pressure control oil ports to achieve the filling function mentioned in the embodiment.

[0028] As one of the embodiments, the valve core of the first valve 701a has a first valve first position 701f and a first valve second position 701g. When the valve core of the first valve 701a is located in the first valve first position 701f, the flow rate of the hydraulic oil passing through the first valve 701a is less than the flow rate of the hydraulic oil passing through the first valve 701a when the valve core of the first valve 701a is located in the first valve second position 701g. This embodiment utilizes the valve core of the first valve 701a to be located in different valve positions to realize the control of the filling flow of the brake accumulator.

[0029] As one of the embodiments, the second valve 701b is required to serve as the pilot valve of the first valve 701a when the brake accumulator is charged. The valve core of the second valve 701b has a second valve first position 701j and a second valve second position 701k. When the valve core of the second valve 701b is located at the second valve first position 701j, it is an open circuit. When the valve core of the second valve 701b is located at the second valve second position 701k, it is a pilot valve. The position of the valve core of the second valve 701b can be used to control the opening and closing of the pilot function of the second valve 701b.

[0030] The first valve 701a is a core component of the energy storage control valve group 701 that controls the flow rate of the hydraulic oil pumped from the pump body 2 into the brake accumulator. The oil inlet of the first valve 701a is connected to the pump body 2, and the oil outlet of the first valve 701a is connected to the brake accumulator through the main oil supply line 701h; the first valve 701a includes a first pressure oil port 701d and a second pressure oil port 701e, both of which are used to control its valve core. In this embodiment, the valve position of the valve core of the first valve 701a is controlled by the pressure difference between the first pressure oil port 701d and the second pressure oil port 701e; the first pressure oil port 701d is connected to the pump body 2, and the first pressure oil port 701d is set to have the same pressure as the oil outlet of the pump body 2.

[0031] As one embodiment, the oil inlet of the second valve 701b is connected to the main oil supply circuit 701h, that is, the second valve 701b takes oil from the main oil supply circuit 701h when performing the pilot function, and the oil outlet of the second valve 701b is connected to the second pressure oil port 701e through the first pilot oil circuit 701l. When the second valve 701b is in a non-open circuit, the second pressure oil port 701e has the same oil pressure as the oil outlet of the second valve 701b, and the valve position of the valve core of the first valve 701a can be controlled based on controlling the valve position of the valve core of the second valve 701b.

[0032] As one embodiment, the second valve 701b includes a third pressure oil port 701i connected to the main oil supply path 701h, and the third pressure oil port 701i is used to control the valve core of the second valve 701b to open / close the pilot function of the second valve 701b.

[0033] The process of the first valve 701a and the second valve 701b working together is further described as follows: refer to Figure 3 , Figure 3The middle arrow represents the pressure transmission direction of the pilot hydraulic oil. When the pressure of the brake accumulator does not exceed the first threshold value, the oil pressure in the brake accumulator is low at this time, and a large flow of fluid replenishment is required; since the brake accumulator is connected to the main oil supply circuit 701h, the pressure of the brake accumulator is transmitted to the third pressure oil port 701i. The pressure of the third pressure oil port 701i is less than the first threshold value. The pressure at this time makes the valve core of the second valve 701b located in the second valve second position 701k, and the hydraulic oil of the main oil supply circuit 701h is introduced into the second pressure oil port 701e through the second valve 701b and the first pilot oil circuit 701l in turn; since the hydraulic oil of the second pressure oil port 701e is directly derived from the brake accumulator, the hydraulic oil of the second valve 701b in the pilot valve state is directly injected into the second pressure oil port 701e, and the pressure difference between the first pressure oil port 701d and the second pressure oil port 701e is small and does not exceed the set second threshold value. The pressure difference at this time ensures that the valve core of the first valve 701a is located in the first valve second position 701g, refer to Figure 4 , Figure 4 The middle arrow represents the injection direction of the hydraulic oil. The pump body 2 sequentially charges the brake accumulator with a large flow of oil through the first valve 701a and the main oil supply line 701h, quickly replenishing the hydraulic oil in the brake accumulator, and the pressure in the brake accumulator gradually recovers. This process generally occurs after the brake has just performed a braking operation.

[0034] refer to Figure 5 , Figure 5 The middle arrow represents the pressure conduction direction of the pilot hydraulic oil. When the pressure of the brake accumulator exceeds the first threshold, the brake accumulator basically meets the flow and pressure requirements of the brake in a short period of time, and a large flow of oil filling is no longer required. Due to the transmission of pressure by the main oil supply circuit 701h, the pressure of the third pressure oil port 701i also reaches the first threshold value simultaneously. The pressure of the third pressure oil port 701i drives the valve core of the second valve 701b to switch to the second valve first position 701j, and the second valve 701b forms a short circuit, and the pilot function of the second valve 701b is closed; it is known that the second pressure oil port 701e is connected to the second pressure oil port 701e through the first pilot oil circuit 701l. After the second valve 701b is closed, the first pilot oil circuit 701l lacks the supply of hydraulic oil. In contrast, since the pressure of the brake accumulator exceeds the first threshold value, the pressure is transmitted to the first pressure oil port 701d. The pressure difference between the first pressure oil port 701d and the second pressure oil port 701e exceeds the second threshold value. The pressure difference drives the valve core of the first valve 701a to switch to the first valve first position 701f. It is known that the flow rate of hydraulic oil through the first valve first position 701f is less than the first valve second position 701g. Figure 6 , Figure 6The middle arrow represents the injection direction of hydraulic oil. The pump body 2 sequentially charges the brake accumulator with a small flow rate through the first valve 701a and the main oil supply circuit 701h. It can be understood that when the pressure of the brake accumulator exceeds the first threshold, the demand for rapid pressure recovery to prepare for the next braking function is met. At this time, a small flow rate of oil is charged to reduce the impact on the brake accumulator. The oil charging process can continue until the pump body 2 is actively paused, or the oil circuit pressure from the pump body 2 to the brake accumulator is balanced, or in other forms.

[0035] refer to Figure 7 , Figure 7 The arrow in the figure is the pressure transmission direction of the pilot hydraulic oil. After the braking operation is performed, the pressure of the brake accumulator is below the first threshold value. The pressure difference between the first pressure oil port 701d and the second pressure oil port 701e will drive the valve core of the first valve 701a to switch to the second position 701g of the first valve, so as to charge the brake accumulator with a large flow rate. Figure 7 The valve position shown will change based on the pressure differential. Figure 3 The valve position status is shown.

[0036] As one embodiment, when the pressure of the brake accumulator exceeds the first threshold, the oil injection power of the pump body 2 can be appropriately reduced, or the excess hydraulic oil can be returned from the energy storage control valve group 701 to the oil tank 1.

[0037] As one example, refer to Figure 1 and Figure 2 In this embodiment, the brakes include: a left front brake 18 of the first axle and a right front brake 19 of the first axle, which are responsible for braking the first axle; a left front brake 20 of the second axle and a right front brake 21 of the second axle, which are responsible for braking the second axle; and a left front brake 22 of the third axle and a right front brake 23 of the third axle, which are responsible for braking the third axle; the oil inlets of the left front brake 20 of the second axle, the right front brake 21 of the second axle, the left front brake 22 of the third axle and the right front brake 23 of the third axle are located on the same route of the main oil supply path 701h.

[0038] The brake accumulator includes accumulator one 3, which is used to inject hydraulic oil into the left front brake 18 of one axle and the right front brake 19 of one axle; accumulator two 4 and accumulator three 5, which are used to synchronously inject hydraulic oil into the left front brake 20 of two axles, the right front brake 21 of two axles, the left front brake 22 of three axles and the right front brake 23 of three axles.

[0039] As one embodiment, the energy storage control valve group 701 also includes a third valve 701c, and the main oil supply circuit 701h is divided into two branches in the third valve 701c, one mainly supplies accumulator 1 3, and the other mainly supplies accumulator 2 4 and accumulator 3 5.

[0040] It is worth noting that the energy storage control valve group 701 can adopt a dual-way filling valve design.

[0041] In the above process description, emphasis is placed on the changes in the valve cores of the first valve 701a and the second valve 701b when their respective oil ports are at different pressures. This embodiment further deepens the specific design scheme.

[0042] As one embodiment, the first valve 701a includes a first spring for controlling its valve core; when the pressure difference between the first pressure oil port 701d and the second pressure oil port 701e does not exceed the second threshold value, that is, during the filling process of the brake accumulator, the sum of the pressure of the second pressure oil port 701e and the elastic force of the first spring is not lower than the pressure of the first pressure oil port 701d; at this time, although the pressure of the second pressure oil port 701e is lower than that of the first pressure oil port 701d, with the help of the first spring, the sum of the pressure of the second pressure oil port 701e and the first spring can overcome the pressure of the first pressure oil port 701d, so that the valve core of the first valve 701a is located in the second position 701g of the first valve.

[0043] When the pressure of the brake accumulator reaches the first threshold, the pressure difference between the first pressure oil port 701d and the second pressure oil port 701e exceeds the second threshold, and the hydraulic oil supply of the second pressure oil port 701e is blocked. Instead, the oil pressure of the first pressure oil port 701d increases along with the brake accumulator. The sum of the pressure of the second pressure oil port 701e and the elastic force of the first spring is lower than the pressure of the first pressure oil port 701d. The pressure difference drives the valve core of the first valve 701a to switch to the first valve first position 701f.

[0044] Similarly, when the brake accumulator is filling the brake, the pressure of the brake accumulator drops to a level not exceeding the first threshold, and based on the pressure change, the valve core of the first valve 701a switches to the first valve second position 701g. In view of the same principle, it is not repeated here.

[0045] Based on a similar principle, as one embodiment, the second valve 701b includes a second spring for controlling its valve core.

[0046] When the brake accumulator is filled with fluid, the pressure of the brake accumulator does not exceed the first threshold value, the pressure of the third pressure oil port 701i does not exceed the elastic force of the second spring, and the elastic force of the second spring overcomes the pressure of the third pressure oil port 701i, ensuring that the valve core of the second valve 701b is located in the second valve second position 701k, and the second valve 701b is in the pilot state, ensuring that the valve core of the first valve 701a is located in the first valve second position 701g, thereby ensuring large flow filling of the brake accumulator.

[0047] When the pressure of the brake accumulator exceeds the first threshold value, the brake accumulator will be filled with fluid, and the pressure of the third pressure oil port 701i exceeds the elastic force of the second spring. The pressure difference drives the valve core of the second valve 701b to switch to the second valve first position 701j, and the oil source of the first pilot oil circuit 701l is cut off, causing the valve core of the first valve 701a to switch to the first valve first position 701f, and the brake accumulator is filled with fluid at a small flow rate.

[0048] As one embodiment, the pump body 2 may be an electronically controlled pump, coupled to the circuit system of the vehicle to achieve active control of startup and shutdown.

[0049] In order to prevent the brake accumulator from being over-inflated by the pump body 2 and reduce the control frequency of the pump body 2, as one embodiment, the hydraulic brake system further includes a relief valve 703, the oil inlet of the relief valve 703 is connected to the oil circuit between the first valve 701a and the pump body 2, and the oil outlet of the relief valve 703 is connected to the oil tank 1; When the pressure of the brake accumulator exceeds the first threshold, the first valve 701a fills the brake accumulator with a small flow rate until it is full or the pump body 2 is closed, and the excess hydraulic oil flows back to the oil tank 1 from the overflow valve 703. This process does not even require active control of the pump body 2 to stop filling.

[0050] As one of the embodiments, the electrically controlled brake valve includes a relay valve and a pilot control valve, both of which are normally closed. The brake accumulator is connected to the oil inlet of the pilot control valve and the oil inlet of the relay valve, respectively, and the oil outlet of the pilot control valve is connected to the pilot oil port of the relay valve. The pilot control valve is coupled to the circuit system of the vehicle to receive instructions. In response to the braking instruction, the pilot control valve is turned on, and the oil outlet of the pilot control valve injects hydraulic oil into the pilot oil port of the relay valve. The relay valve is turned on, and the brake accumulator outputs hydraulic oil to the brake accumulator through the relay valve, thereby safely braking.

[0051] As one example, refer to Figure 2The pilot control valve includes a first electro-hydraulic proportional brake valve 704 and a second electro-hydraulic proportional brake valve 705, and the relay valve includes a relay valve 18, a relay valve 29 and a relay valve 3 10. The oil inlets of the first electro-hydraulic proportional brake valve 704 and the relay valve 18 are both connected to the accumulator 13, the oil outlet of the first electro-hydraulic proportional brake valve 704 is connected to the pilot oil port of the relay valve 18, and the first electro-hydraulic proportional brake valve 704 controls the opening and closing of the relay valve 18 in response to the brake command; the oil outlet of the relay valve 18 is connected to the oil inlets of the left front brake 18 of the first shaft and the right front brake 19 of the first shaft. The oil inlets of the second electro-hydraulic proportional brake valve 705, relay valve two 9 and relay valve three 10 are all connected to accumulator two 4 and accumulator three 5, the oil outlet of the second electro-hydraulic proportional brake valve 705 is respectively connected to the pilot oil ports of relay valve two 9 and relay valve three 10, the oil outlet of relay valve two 9 is connected to the oil inlet of the second-axis left front brake 20 and the second-axis right front brake 21, the oil outlet of relay valve three 10 is connected to the oil inlet of the third-axis left front brake 22 and the third-axis right front brake 23, the second electro-hydraulic proportional brake valve 705 controls the braking operation of the second and third axes in response to the braking command.

[0052] As one of the embodiments, the energy storage control valve group 701 also includes an oil return circuit 701m. After the brake completes the braking action, the hydraulic oil flows from the oil inlet of the brake through the relay valve and the pilot control valve into the oil return circuit 701m, and then returns to the oil tank 1; the oil outlet of the overflow valve 703 is also connected to the oil return circuit 701m.

[0053] When performing a braking operation, the pressure of the brake accumulator will drop rapidly. Especially when the storage capacity of the brake accumulator model used is small, the unstable working pressure of the brake accumulator will affect the linearity of the service brake. As one embodiment, refer to Figure 1 The hydraulic brake system further comprises a compensation accumulator 25 connected to the brake and a pressure sensor 11 for detecting the pressure of the brake accumulator, the compensation accumulator 25 being connected to the brake accumulator; In response to the pressure drop of the brake accumulator detected by the pressure sensor 11, the compensation accumulator 25 releases oil to perform pressure compensation for the brake accumulator to improve the linearity of service braking.

[0054] As one embodiment, the pressure sensor 11 and the switch of the compensation accumulator 25 can be coupled to the circuit system of the vehicle, and the above functions can be realized through the logic control of the circuit system.

[0055] As one example, refer to Figure 1The pressure sensor 11 is used to detect the pressure of the accumulator 3, and a pressure sensor 2 12 based on the same principle as the pressure sensor 11 is also provided. The pressure sensor 2 12 is used to detect the pressure of the accumulator 2 4 and the accumulator 3 5, and the compensation accumulator 25 is also used for linearity compensation of the accumulator 2 4 and the accumulator 3 5.

[0056] refer to Figure 1 As one embodiment, the hydraulic braking system also includes a pressure-compensating solenoid valve 27 and a pressure sensor 26 for detecting the pressure of the compensating accumulator 25. The oil inlet of the pressure-compensating solenoid valve 27 is connected to the pump body 2, and the oil outlet is connected to the compensating accumulator 25. The pressure-compensating solenoid valve 27 is normally closed. In response to the pressure of the compensating accumulator 25 being lower than the third threshold value, the pressure-compensating solenoid valve 27 is turned on, and the pump body 2 compensates the pressure of the compensating accumulator 25.

[0057] The purpose of the compensation accumulator 25 is to compensate the pressure of the compensation accumulator 25 in real time, ensuring that the pressure of the compensation accumulator 25 can compensate the brake accumulator. As one embodiment, the pressure sensor 8 26 and the pressure compensation solenoid valve 27 are coupled to the circuit system of the vehicle, and the above function is realized through the logic control of the circuit system.

[0058] The hydraulic brake system of the electronically controlled vehicle provided in this embodiment can be well coupled with the circuit system of the vehicle. The process of filling the brake accumulator and braking the brake relies on the operation of the hydraulic system's own structure, and does not require excessive participation of the circuit system control. Relying on the pressure relief and flow relief function of the overflow valve 703, the vehicle's circuit system's active control frequency of the pump body 2 is also greatly reduced. Compared with a purely electronically controlled braking system, this embodiment can complete the braking action with high reliability, and has a fast response, sufficient flow, and high braking stability and efficiency. It can also realize rapid filling of the brake accumulator and reduce damage caused by over-charging of the brake accumulator, meeting long-term and high-frequency charging requirements. Embodiment 3

[0059] This embodiment provides a hydraulic brake system for an electronically controlled vehicle, which is improved on the basis of the second embodiment. For details not provided, please refer to the second embodiment.

[0060] It is worth noting that existing electronically controlled vehicles still use hydraulic braking systems and parking systems, but when the circuit system fails, the vehicle may be unable to park, which may cause safety hazards.

[0061] In order to solve the above problems, this embodiment, based on the structure of the second embodiment, further includes an accumulator 46, a parking solenoid valve 706 and a parking brake 24 connected to the oil outlet of the parking solenoid valve 706.

[0062] Compared with the conventional parking brake 24, the parking brake 24 provided in this embodiment is in a parking state when oil is not supplied, but the parking state is released when oil is supplied to the parking brake 24.

[0063] In order to couple into the pipeline of the hydraulic brake system in the second embodiment, refer to Figure 2 In this embodiment, the accumulator 46 is connected to the main oil supply path 701h, and the pump body 2 charges the accumulator 46 through the main oil supply path 701h. The accumulator 46 supplies oil to the parking brake 24, but the accumulator 46 is connected to the oil inlet of the parking solenoid valve 706, and the parking solenoid valve 706 controls the oil supply of the accumulator 46 to the parking brake 24. In the description of this embodiment, the parking solenoid valve 706 is normally closed when not energized, and is connected when energized.

[0064] Under normal driving conditions, the parking solenoid valve 706 can be powered from the circuit system, and the accumulator 26 charges the parking brake 24 with oil through the parking solenoid valve 706, so that the parking brake 24 is always in a released parking state.

[0065] When parking is required or the circuit system fails, the oil inlet of the parking solenoid valve 706 is normally closed when no power is supplied, and the parking brake 24 is in the parking state.

[0066] The hydraulic brake system of the electronically controlled vehicle provided in this embodiment actively utilizes the existing hydraulic system related to brake control to ensure that the accumulator 4 6 is reliably filled with fluid from the main oil supply line 701h, and by cleverly designing the energized and de-energized opening and closing states of the parking solenoid valve 706 and correspondingly designing the control logic of the parking brake 24, it is ensured that the vehicle can be in a parking state when the circuit system fails.

[0067] After the vehicle is in the parked state, maintenance and rescue need to release the parking state, refer to Figure 2 As one embodiment, the hydraulic brake system also includes a manual pump 702, the oil inlet of the manual pump 702 is connected to the oil tank 1, and the oil outlet is connected to the parking brake 24; the manual pump 702 is used to manually pump oil for the parking brake 24 to release the parking brake 24.

[0068] Electric drive mining dump trucks are off-road dump trucks, mainly used for the transportation of ores and mineral materials in large open-pit mines, with multiple loads uphill or heavy loads downhill. Traditional mining trucks mostly use pneumatic brake systems, which are difficult to arrange and have many fault problems during operation. The hydraulic brake system of the electric control vehicle provided in this embodiment is applied to electric drive mining dump trucks. The electric drive mining truck mainly relies on electric braking during operation. However, in the event of electric braking failure, the parking function of the hydraulic brake system provided in this embodiment is the last safety guarantee.

[0069] As one embodiment, the hydraulic braking system also includes a parking pressure reducing valve 707, the oil inlet of the parking pressure reducing valve 707 is connected to the oil outlet of the parking solenoid valve 706, the oil outlet of the parking pressure reducing valve 707 is connected to the parking brake 24, and the parking pressure reducing valve 707 also includes an oil return port connected to the oil tank 1.

[0070] When the parking solenoid valve 706 is powered on and hydraulic oil is injected, the hydraulic oil enters the parking brake 24 through the parking pressure reducing valve 707, and the parking brake 24 is released from the braking state or in a non-braking state, allowing the vehicle to travel; the parking solenoid valve 706 is not powered off, and the parking pressure reducing valve 707 and the parking brake 24 get hydraulic oil that returns to the oil tank 1 through the oil return port of the parking pressure reducing valve 707, and the parking brake 24 is in a braking state. The oil return port of the parking pressure reducing valve 707 can be connected to the oil return oil circuit 701m.

[0071] As one embodiment, the parking solenoid valve 706 may be a two-position three-way solenoid valve.

[0072] As one of the embodiments, based on the pressure sensor 1 11 and the pressure sensor 2 12 mentioned in the embodiment 2, this embodiment also includes a pressure sensor 3 13, a pressure sensor 4 14, a pressure sensor 5 15 and a pressure sensor 6 16; wherein, the pressure sensor 3 13 is used to detect the pressure of the accumulator 4 6, the pressure sensor 4 14 is used to detect the pressure of the oil inlet of the first valve 701a, the pressure sensor 5 15 is used to detect the pressure of the oil outlet of the first electro-hydraulic proportional brake valve 704, and the pressure sensor 6 16 is used to detect the pressure of the oil outlet of the second electro-hydraulic proportional brake valve 705.

[0073] The pressure sensor can be coupled to the circuit system of the vehicle, and in response to abnormal pressure, the parking solenoid valve 706 is de-energized to perform braking.

[0074] As one of the embodiments, it also includes a pressure sensor 717 for detecting the pressure of the return oil circuit 701m.

[0075] In summary, the hydraulic brake system of the electronically controlled vehicle provided in this embodiment, on the basis of the previous embodiment, also ensures the parking function when the electronically controlled vehicle circuit system is paralyzed, and the oil circuit required to realize this function can be improved based on the oil circuit related to the braking function, thereby reducing the system scale; Figure 2 , components related to braking and parking functions can be integrated into the brake valve group 7 for easy maintenance.

[0076] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "one", "two", etc. in "accumulator one", "accumulator two", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "one", "two", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0077] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "provided at", "provided with", "located", "installed", "set", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. "Hinged" includes "rotational connection".

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A hydraulic brake system for an electronically controlled vehicle, characterized in that: include, An oil tank (1) and a pump body (2) for pumping hydraulic oil in the oil tank (1); a normally closed electrically controlled brake valve and a brake in communication with the electrically controlled brake valve; An energy storage control valve group (701) and a brake accumulator, the energy storage control valve group (701) being connected to the pump body (2) and the brake accumulator respectively, and the electrically controlled brake valve being connected to the brake accumulator; When the pressure of the brake accumulator does not exceed a first threshold value, the energy storage control valve group (701) conducts between the pump body (2) and the brake accumulator, and the pump body (2) fills the brake accumulator with oil; When the pressure of the brake accumulator exceeds a first threshold, the energy storage control valve group (701) reduces the oil filling flow rate; The electrically controlled brake valve conducts flow between the brake accumulator and the brake in response to a braking command, and the brake accumulator outputs hydraulic oil to drive the brake to perform a vehicle braking operation.

2. The hydraulic brake system of an electronically controlled vehicle according to claim 1, characterized in that: The energy storage control valve group (701) comprises a first valve (701a) and a second valve (701b); The valve core of the first valve (701a) has a first valve first position (701f) and a first valve second position (701g), and the flow rate when the valve core of the first valve (701a) is in the first valve first position (701f) is smaller than the flow rate when the valve core is in the first valve second position (701g); The valve core of the second valve (701b) has a second valve first position (701j) and a second valve second position (701k); when the valve core of the second valve (701b) is in the second valve first position (701j), it is an open circuit; when the valve core of the second valve (701b) is in the second valve second position (701k), it is a pilot valve; The oil inlet of the first valve (701a) is connected to the pump body (2), and the oil outlet of the first valve (701a) is connected to the brake accumulator via a main oil supply line (701h); the first valve (701a) comprises a first pressure oil port (701d) and a second pressure oil port (701e), both of which are used to control the valve core thereof, and the first pressure oil port (701d) is connected to the pump body (2); The oil inlet of the second valve (701b) is connected to the main oil supply circuit (701h), and the oil outlet of the second valve (701b) is connected to the second pressure oil port (701e) through the first pilot oil circuit (701l); The second valve (701b) comprises a third pressure oil port (701i) connected to the main oil supply path (701h), and the third pressure oil port (701i) is used to control the valve core of the second valve (701b); When the pressure of the brake accumulator does not exceed the first threshold value, the pressure of the third pressure oil port (701i) is lower than the first threshold value, the valve core of the second valve (701b) is located in the second valve second position (701k), and the hydraulic oil of the main oil supply circuit (701h) is introduced into the second pressure oil port (701e) through the second valve (701b) and the first pilot oil circuit (701l) in sequence; the pressure difference between the first pressure oil port (701d) and the second pressure oil port (701e) does not exceed the second threshold value, the valve core of the first valve (701a) is located in the first valve second position (701g), and the pump body (2) fills the brake accumulator with oil through the first valve (701a) and the main oil supply circuit (701h) in sequence; When the pressure of the brake accumulator exceeds a first threshold value, the pressure of the third pressure oil port (701i) reaches the first threshold value, and the pressure of the third pressure oil port (701i) drives the valve core of the second valve (701b) to switch to the first position (701j) of the second valve, and the second valve (701b) forms a short circuit; the pressure difference between the first pressure oil port (701d) and the second pressure oil port (701e) exceeds a second threshold value, and the pressure difference drives the valve core of the first valve (701a) to switch to the first valve first position (701f), and the pump body (2) fills the brake accumulator with oil through the first valve (701a) and the main oil supply circuit (701h) in sequence.

3. The hydraulic brake system of an electronically controlled vehicle according to claim 2, characterized in that: The first valve (701a) comprises a first spring for controlling a valve core thereof; When the pressure difference between the first pressure oil port (701d) and the second pressure oil port (701e) does not exceed a second threshold value, the sum of the pressure of the second pressure oil port (701e) and the elastic force of the first spring is not lower than the pressure of the first pressure oil port (701d), and the valve core of the first valve (701a) is located in the first valve second position (701g); When the pressure difference between the first pressure oil port (701d) and the second pressure oil port (701e) exceeds a second threshold value, the sum of the pressure of the second pressure oil port (701e) and the elastic force of the first spring is lower than the pressure of the first pressure oil port (701d), and the pressure difference drives the valve core of the first valve (701a) to switch to the first valve first position (701f).

4. The hydraulic brake system of an electronically controlled vehicle according to claim 2, characterized in that: The second valve (701b) comprises a second spring for controlling a valve core thereof; When the pressure of the brake accumulator does not exceed the first threshold value, the pressure of the third pressure oil port (701i) does not exceed the elastic force of the second spring, and the valve core of the second valve (701b) is located at the second valve second position (701k); When the pressure of the brake accumulator exceeds the first threshold, the pressure of the third pressure oil port (701i) exceeds the elastic force of the second spring, and the pressure difference drives the valve core of the second valve (701b) to switch to the second valve first position (701j).

5. The hydraulic brake system of an electronically controlled vehicle according to claim 2, characterized in that: It also includes an accumulator four (6), a parking solenoid valve (706), and a parking brake (24) connected to an oil outlet of the parking solenoid valve (706); The pump body (2) charges the accumulator four (6) with oil through the main oil supply path (701h), and the accumulator four (6) is connected to the oil inlet of the parking solenoid valve (706); When the parking solenoid valve (706) is not energized, its oil inlet is normally closed, and the parking brake (24) is in a parking state; The parking solenoid valve (706) is turned on when energized, and the accumulator four (6) charges the parking brake (24) with oil through the parking solenoid valve (706), and the parking brake (24) releases the parking state.

6. The hydraulic brake system for an electronically controlled vehicle according to claim 5, characterized in that: It also comprises a manual pump (702), the oil inlet of the manual pump (702) being connected to the oil tank (1), and the oil outlet being connected to the parking brake (24); the manual pump (702) is used to manually pump oil for the parking brake (24) to release the parking brake (24).

7. The hydraulic brake system for an electronically controlled vehicle according to claim 2, characterized in that: It also comprises a relief valve (703), the oil inlet of the relief valve (703) being connected to the oil path between the first valve (701a) and the pump body (2), and the oil outlet of the relief valve (703) being connected to the oil tank (1); When the brake accumulator is full, excess hydraulic oil flows back from the overflow valve (703) to the oil tank (1).

8. The hydraulic brake system for an electronically controlled vehicle according to claim 1, characterized in that: The electrically controlled brake valve includes a relay valve and a pilot control valve, both of which are normally closed. The brake accumulator is connected to the oil inlet of the pilot control valve and the oil inlet of the relay valve respectively, and the oil outlet of the pilot control valve is connected to the pilot oil port of the relay valve. In response to the braking command, the pilot control valve is turned on, and the oil outlet of the pilot control valve injects hydraulic oil into the pilot oil port of the relay valve. The relay valve is turned on, and the brake accumulator outputs hydraulic oil to the brake accumulator through the relay valve.

9. The hydraulic brake system for an electronically controlled vehicle according to claim 1, characterized in that: It also includes a compensation accumulator (25) connected to the brake and a pressure sensor (11) for detecting the pressure of the brake accumulator, wherein the compensation accumulator (25) is connected to the brake accumulator; In response to a pressure drop in the brake accumulator, the compensation accumulator (25) performs pressure compensation for the brake accumulator.

10. The hydraulic brake system for an electronically controlled vehicle according to claim 9, characterized in that: It also includes a pressure compensation solenoid valve (27) and a pressure sensor eight (26) for detecting the pressure of the compensation accumulator (25); the oil inlet of the pressure compensation solenoid valve (27) is connected to the pump body (2), and the oil outlet is connected to the compensation accumulator (25); the pressure compensation solenoid valve (27) is normally closed; in response to the pressure of the compensation accumulator (25) being lower than a third threshold value, the pressure compensation solenoid valve (27) is turned on, and the pump body (2) compensates the pressure of the compensation accumulator (25).

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