Electro-hydraulic braking system for automatic driving tracked vehicle

Abstract

The utility model relates to an electro-hydraulic braking system for an automatic driving tracked vehicle. The electro-hydraulic braking system comprises a hydrostatic transmission device, an electric control brake valve, a first brake oil cylinder and a second brake oil cylinder. The electric control brake valve comprises a brake valve block, a two-position electromagnetic valve, a throttling valve and a proportional overflow valve, the two-position electromagnetic valve, the throttling valve and the proportional overflow valve are integrally installed in the brake valve block and communicate with one another through an inner oil way of the brake valve block, and a first oil inlet, a first oil return opening, a first oil outlet and a second oil outlet are formed in the brake valve block. The first oil outlet and the second oil outlet are respectively communicated with the first brake oil cylinder and the second brake oil cylinder; an oil suction port of an oil supplementing pump in the hydrostatic transmission device is communicated with the hydraulic oil tank, the first oil inlet is communicated with an oil outlet of the oil supplementing pump in the hydrostatic transmission device, the first oil return port is communicated with the hydraulic oil tank, and an oil return port of the hydrostatic transmission device is communicated with the hydraulic oil tank. The device is compact in structure and reliable in performance.

Description

Technical Field

[0001] This utility model relates to the field of autonomous driving technology for tracked vehicles, and in particular to an electro-hydraulic braking system for autonomous tracked vehicles. Background Technology

[0002] The autonomous tracked vehicle is an autonomous driving power chassis developed for tobacco-growing areas in hilly and mountainous regions such as Yunnan, Guizhou, and Hunan. To better adapt to the agronomical requirements of tobacco cultivation in hilly and mountainous areas, the autonomous tracked vehicle is developed based on the existing hydraulically braked tracked vehicle. However, the braking system of the existing hydraulically braked tracked vehicle consists of a steering valve, steering cylinder, automatic parking device, and wet brake. Its advantage is that steering and braking functions can be achieved by controlling the steering valve, and parking function can be achieved by the automatic parking device.

[0003] However, the existing hydraulic brake tracked vehicle braking system has the following shortcomings: 1. Existing hydraulic brake tracked vehicles can switch between manual and automatic braking at will for service braking; an automatic parking device can be added for parking, but the automatic parking device uses spring brakes. Poor pressure relief of the oil can lead to a delay in the release of the brake spring force, especially when parking on a slope, which can easily cause the vehicle to roll away; 2. Tobacco planting areas are mostly located in hilly and mountainous areas. With the development of large-scale tobacco planting, tracked vehicles with automatic driving functions will gradually show their advantages; the braking system of automatic driving tracked vehicles must adopt automatic control and be able to meet the braking requirements under various complex working conditions. The existing braking system cannot meet the braking requirements of automatic driving tracked vehicles. Utility Model Content

[0004] In view of the problems existing in the prior art, this utility model provides an electro-hydraulic braking system for autonomous driving tracked vehicles.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: an electro-hydraulic braking system for an autonomous driving tracked vehicle, including a hydrostatic transmission device, an electronically controlled brake valve, a first brake cylinder, and a second brake cylinder.

[0006] The electronically controlled brake valve includes a brake valve block, a two-position solenoid valve, a throttle valve, and a proportional relief valve. The two-position solenoid valve, the throttle valve, and the proportional relief valve are integrated and installed inside the brake valve block. The two-position solenoid valve, the throttle valve, and the proportional relief valve are interconnected through the internal oil passage of the brake valve block. The brake valve block is provided with a first oil inlet, a first oil return port, a first oil outlet, and a second oil outlet. The first oil outlet and the second oil outlet are respectively connected to the first brake cylinder and the second brake cylinder.

[0007] In the hydrostatic transmission device, the suction port of the replenishing pump is connected to the hydraulic oil tank, the first inlet is connected to the outlet of the replenishing pump, the first return port is connected to the hydraulic oil tank, and the return port of the hydrostatic transmission device is connected to the hydraulic oil tank.

[0008] As a preferred embodiment, the hydrostatic transmission device is installed on the right side of the travel gearbox, the electronically controlled brake valve is installed at the front end of the travel gearbox, and the first brake cylinder and the second brake cylinder are respectively installed on the left and right sides of the drive end of the travel gearbox.

[0009] As a preferred embodiment, a first brake spring is provided in the rodless chamber of the first brake cylinder, and a second brake spring is provided in the rodless chamber of the second brake cylinder. The first oil outlet is connected to the rod chamber of the first brake cylinder, and the second oil outlet is connected to the rod chamber of the second brake cylinder.

[0010] As a preferred embodiment, the brake valve block is also provided with a first pressure feedback port and a second pressure feedback port, and a pressure sensor is provided at the second pressure feedback port.

[0011] As a preferred embodiment, the oil inlet of the two-position solenoid valve is connected to the first oil inlet and the first pressure feedback port, the oil outlet of the two-position solenoid valve is connected to the oil inlet of the throttle valve, the oil outlet of the throttle valve is connected to the second pressure feedback port, the first oil outlet, the second oil outlet, and the oil inlet of the proportional relief valve; and the oil outlet of the proportional relief valve is connected to the first return port.

[0012] As a preferred embodiment, the system also includes an oil suction filter element, the oil inlet of which is connected to the hydraulic oil tank, and the oil outlet of which is connected to the oil suction port of the replenishing pump in the hydrostatic transmission device.

[0013] As a preferred embodiment, a cooler is also included, wherein the oil inlet of the cooler is connected to the first oil return port and the oil return port of the hydrostatic transmission device, and the oil outlet of the cooler is connected to the hydraulic oil tank.

[0014] The beneficial effects of this application are: 1. This application is applicable to autonomous tracked vehicles, which simplifies the braking system structure and reduces manufacturing costs.

[0015] 2. This application is equipped with an electronically controlled brake valve, which can realize the functions of service braking, automatic parking, and automatic brake release by controlling the electronically controlled brake valve; during braking, the pressure oil drain passage is directly connected to the hydraulic oil tank, the brake spring force is released in a timely manner, and the braking is reliable.

[0016] 3. This application is equipped with a pressure sensor, which can monitor the pressure of the first brake cylinder and the second brake cylinder in real time. When the pressure is lower than the set value, the electronically controlled brake valve can be controlled to replenish the pressure of the first brake cylinder and the second brake cylinder to prevent the vehicle from running with the brakes on and to ensure the reliability of the electro-hydraulic brake system. Attached Figure Description

[0017] Figure 1 This is a hydraulic schematic diagram of the present invention;

[0018] Figure 2 This is a schematic diagram of the electrically controlled brake valve in the pressure replenishment start state and the brake release start state of this utility model;

[0019] Figure 3 This is a schematic diagram of the electrically controlled brake valve for the pressure replenishment endpoint state and the brake release endpoint state of this utility model.

[0020] Figure 4 This is a schematic diagram of the electronically controlled brake valve for vehicle braking according to this utility model;

[0021] Figure 5 This is a schematic diagram of the electronically controlled brake valve for parking according to this utility model.

[0022] The markings in the diagram are: 1. Hydraulic oil tank, 2. Suction filter element, 3. Hydrostatic transmission device, 4. Electro-controlled brake valve, 41. Brake valve block, 42. Two-position solenoid valve, 43. Pressure sensor, 44. Throttle valve, 45. Proportional relief valve, 5. First brake cylinder, 6. Second brake cylinder, 7. Cooler. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Please see Figure 1-5This utility model provides an electro-hydraulic braking system for an automated guided vehicle, including a hydrostatic transmission device 3, an electronically controlled brake valve 4, a first brake cylinder 5, and a second brake cylinder 6. The electronically controlled brake valve 4 includes a brake valve block 41, a two-position solenoid valve 42, a throttle valve 44, and a proportional relief valve 45. The two-position solenoid valve 42, the throttle valve 44, and the proportional relief valve 45 are integrated and installed within the brake valve block 41. The two-position solenoid valve 42, the throttle valve 44, and the proportional relief valve 45 are connected through internal oil passages in the brake valve block 41. The brake valve block 41 is interconnected and has a first oil inlet P1, a first oil return port T1, a first oil outlet L, and a second oil outlet R. The first oil outlet L and the second oil outlet R are respectively connected to the first brake cylinder 5 and the second brake cylinder 6. The suction port S of the oil replenishing pump in the hydrostatic transmission device 3 is connected to the hydraulic oil tank 1. The first oil inlet P1 is connected to the oil outlet of the oil replenishing pump in the hydrostatic transmission device 3. The first oil return port T1 is connected to the hydraulic oil tank 1. The return port T of the hydrostatic transmission device 3 is connected to the hydraulic oil tank 1.

[0025] Specifically, it also includes an oil suction filter element 2 and a cooler 7. The oil inlet of the oil suction filter element 2 is connected to the hydraulic oil tank 1, and the oil outlet of the oil suction filter element 2 is connected to the oil suction port S of the replenishing pump in the hydrostatic transmission device 3. The oil inlet of the cooler 7 is connected to the first return oil port T1 and the return oil port T of the hydrostatic transmission device 3, and the oil outlet of the cooler 7 is connected to the hydraulic oil tank 1.

[0026] The hydrostatic transmission device 3 can be the hydrostatic transmission device described in existing patent CN115447543A. The hydrostatic transmission device 3 is installed on the right side of the travel gearbox of the autonomous tracked vehicle. The electronically controlled brake valve 4 is installed at the front end of the travel gearbox. The first brake cylinder 5 and the second brake cylinder 6 are respectively installed on the left and right sides of the drive end of the travel gearbox. The hydrostatic transmission device 3 has a built-in oil replenishment system. When the autonomous tracked vehicle starts, the oil replenishment system can provide the necessary oil and output stable pressure oil; when the autonomous tracked vehicle is turned off, the built-in oil replenishment system of the hydrostatic transmission device 3 does not work.

[0027] The first brake cylinder 5 has a first brake spring in its rodless chamber, and the second brake cylinder 6 has a second brake spring in its rodless chamber. The braking principles of the first and second brake cylinders are the same. Taking the first brake cylinder 5 as an example, when the thrust generated by the hydraulic oil passing through the first brake cylinder 5 is less than the pressure of the first brake spring, the braking system begins to brake; when the hydraulic oil pressure is zero, the braking system is fully engaged. The first oil outlet L is connected to the rod chamber of the first brake cylinder 5, and the second oil outlet R is connected to the rod chamber of the second brake cylinder 6.

[0028] The brake valve block 41 is also provided with a first pressure feedback port GP1 and a second pressure feedback port GP2. A pressure sensor 43 is provided at the second pressure feedback port GP2. The oil inlet of the two-position solenoid valve 42 is connected to the first oil inlet P1 and the first pressure feedback port GP1. The oil outlet of the two-position solenoid valve 42 is connected to the oil inlet of the throttle valve 44. The oil outlet of the throttle valve 44 is connected to the second pressure feedback port GP2, the first oil outlet L, the second oil outlet R, and the oil inlet of the proportional relief valve 45. The oil outlet of the proportional relief valve 45 is connected to the first return port T1.

[0029] The proportional relief valve 45 installed in the electronically controlled brake valve 4 can control the thrust of the first brake cylinder 5 and the second brake cylinder 6 according to the magnitude of the input current signal, thereby realizing the braking system's gentle braking and emergency braking. The flow rate and pressure drop of the pressurized oil are controlled by adjusting the opening of the throttle valve 44, ensuring the normal operation of the hydraulic oil replenishment system of the hydrostatic transmission device 3 during service braking. The pressure sensor 43 can monitor the hydraulic oil pressure in the first brake cylinder 5 and the second brake cylinder 6 in real time; during vehicle operation, when the detected hydraulic oil pressure value is lower than the set pressure, the replenishment system is activated to replenish the pressure; when the pressure value is greater than or equal to the set pressure, the replenishment system is not activated.

[0030] This electro-hydraulic braking system has an automatic brake release state. When the electro-hydraulic braking system is in the pressure replenishment start state and the brake release start state, its principle is as follows: (e.g., ...) Figure 2 As shown, when the autonomous tracked vehicle starts, it drives the oil replenishment pump of the hydrostatic transmission device 3 to work, and pressurized oil enters the first oil inlet P1 of the electronically controlled brake valve 4; the two-position solenoid valve 42 is energized, and the first oil inlet P1, the first oil outlet L, and the second oil outlet R are connected; the proportional relief valve 45 is energized, and the first oil outlet L, the second oil outlet R and the first return oil outlet T1 are disconnected; at this time, the pressurized oil enters the first brake cylinder 5 and the second brake cylinder 6 through the first oil outlet L and the second oil outlet R, and the braking system begins to replenish pressure; at this time, the thrust generated by the pressurized oil is greater than the elastic force of the first brake spring and the second brake spring, and the first brake spring and the second brake spring are compressed, and the braking begins to be released.

[0031] The principle of this electro-hydraulic braking system when it is in the pressure replenishment endpoint state and the braking release endpoint state is as follows: Figure 3 As shown, the braking system continues to replenish pressure. When the pressure sensor 43 detects that the braking pressure has reached the set value, the two-position solenoid valve 42 is de-energized, the first oil inlet P1 is disconnected from the first oil outlet L and the second oil outlet R, the proportional relief valve 45 is energized, and the first oil outlet L and the second oil outlet R are disconnected from the first return oil outlet T1, and the pressure replenishment is completed. At this time, the thrust generated by the pressurized oil will completely compress the first brake spring and the second brake spring, and the brake will be completely released.

[0032] This electro-hydraulic braking system has a service braking state. When in the service braking state, its principle is as follows: Figure 4 As shown, when the autonomous tracked vehicle starts, it drives the oil replenishment pump of the hydrostatic transmission device 3 to work. The pressurized oil enters the first oil inlet P1 of the electronic brake valve 4. The two-position solenoid valve 42 is energized, connecting the first oil inlet P1, the first oil outlet L, and the second oil outlet R. The proportional relief valve 45 is gradually de-energized, gradually connecting the first oil outlet L, the second oil outlet R, and the first return oil outlet T1. At this time, the pressurized oil is connected to the first return oil outlet T1 through the proportional relief valve 45. The pressure in the first brake cylinder 5 and the second brake cylinder 6 gradually decreases. When the brake spring force is greater than the thrust generated by the pressurized oil, the braking system begins to gradually take effect and completes the service braking.

[0033] This electro-hydraulic braking system has an automatic parking mode. When in automatic parking mode, the principle is as follows: Figure 5 As shown, the two-position solenoid valve 42 is de-energized, disconnecting the first oil inlet P1 from the first oil outlet L and the second oil outlet R; the proportional relief valve 45 is de-energized, connecting the first oil outlet L, the second oil outlet R to the first return oil outlet T1. At this time, there is no pressure oil in the first brake cylinder 5 and the second brake cylinder 6, and the first brake spring and the second brake spring are fully activated, completing the parking process.

[0034] By controlling the electronically controlled brake valve 4, the functions of driving brake, automatic parking, and automatic brake release can be realized; during braking, the pressure oil drain passage is directly connected to the hydraulic oil tank 1, the brake spring force is released in time, and the braking is reliable.

[0035] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An electro-hydraulic braking system for an autonomous tracked vehicle, characterized in that, The hydraulic transmission device (3), the electric control brake valve (4), the first brake oil cylinder (5) and the second brake oil cylinder (6) are included. The electric control brake valve (4) includes a brake valve block (41), a two-position electromagnetic valve (42), a throttle valve (44) and a proportional overflow valve (45), the two-position electromagnetic valve (42), the throttle valve (44) and the proportional overflow valve (45) are integratedly installed in the brake valve block (41), the two-position electromagnetic valve (42), the throttle valve (44) and the proportional overflow valve (45) are communicated with each other through the internal oil channel of the brake valve block (41), the first oil inlet, the first oil return, the first oil outlet and the second oil outlet are arranged in the brake valve block (41), the first oil outlet and the second oil outlet are communicated with the first brake oil cylinder (5) and the second brake oil cylinder (6) respectively. The oil suction port of the oil supplement pump in the hydraulic transmission device (3) is communicated with the hydraulic oil tank (1), the first oil inlet is communicated with the oil outlet of the oil supplement pump in the hydraulic transmission device (3), the first oil return is communicated with the hydraulic oil tank (1), and the oil return of the hydraulic transmission device (3) is communicated with the hydraulic oil tank (1).

2. The electro-hydraulic braking system for an autonomous tracked vehicle according to claim 1, wherein: The hydraulic transmission device (3) is installed on the right side of the travel gearbox, the electric control brake valve (4) is installed on the front end of the travel gearbox, and the first brake oil cylinder (5) and the second brake oil cylinder (6) are respectively installed on the left and right sides of the driving end of the travel gearbox.

3. The electro-hydraulic braking system for an autonomous tracked vehicle of claim 1, wherein: The first brake spring is arranged in the rodless cavity of the first brake oil cylinder (5), the second brake spring is arranged in the rodless cavity of the second brake oil cylinder (6), the first oil outlet is communicated with the rod cavity of the first brake oil cylinder (5), and the second oil outlet is communicated with the rod cavity of the second brake oil cylinder (6).

4. The electro-hydraulic braking system for an autonomous tracked vehicle according to claim 3, wherein: The first pressure feedback port and the second pressure feedback port are further arranged in the brake valve block (41), and the pressure sensor (43) is arranged at the second pressure feedback port.

5. The electro-hydraulic braking system for an autonomous tracked vehicle according to claim 4, wherein: The oil inlet of the two-position electromagnetic valve (42) is communicated with the first oil inlet and the first pressure feedback port, the oil outlet of the two-position electromagnetic valve (42) is communicated with the oil inlet of the throttle valve (44), the oil outlet of the throttle valve (44) is communicated with the second pressure feedback port, the first oil outlet, the second oil outlet and the oil inlet of the proportional overflow valve (45), and the oil outlet of the proportional overflow valve (45) is communicated with the first oil return.

6. The electro-hydraulic braking system for an autonomous tracked vehicle of claim 1, wherein: The oil suction filter element (2) is further included, the oil inlet of the oil suction filter element (2) is communicated with the hydraulic oil tank (1), and the oil outlet of the oil suction filter element (2) is communicated with the oil suction port of the oil supplement pump in the hydraulic transmission device (3).

7. The electro-hydraulic braking system for an autonomous tracked vehicle of claim 1, wherein: The cooler (7) is further included, the oil inlet of the cooler (7) is communicated with the first oil return and the oil return of the hydraulic transmission device (3), and the oil outlet of the cooler (7) is communicated with the hydraulic oil tank (1).

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