Electro-hydraulic braking system for tractor

Abstract

The utility model relates to an electro-hydraulic braking system for a tractor, which comprises a brake terminal assembly, a foot brake valve group, an electric control brake valve group, a shuttle valve assembly, a pressure oil source and an oil can, and the electric control brake valve group, the pressure oil source and the shuttle valve assembly form an electric control brake oil way. The foot brake valve set, the oil pot and the shuttle valve assembly form a foot brake oil way, the brake terminal assembly is communicated with the electric control brake oil way, and the foot brake oil way is communicated with the electric control brake oil way through the shuttle valve assembly. The foot brake valve group and the electric control brake valve group are respectively arranged and are used for respectively carrying out manual control and electric control on the brake terminal assembly, so that the brake of the brake terminal assembly in a manual mode and an electric control mode is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of electro-hydraulic brake systems, in particular to an electro-hydraulic brake system for a tractor. Background Art

[0002] With the promotion of agricultural modernization, the modernization of machinery as a development focus has attracted more and more attention.

[0003] Among them, tractors have made many exploratory attempts to achieve unmanned control methods. The outstanding advantages of unmanned operation are not only that it can realize mechanical operations in all weather, all areas, and all time, but more importantly, it is the outstanding manifestation of human wisdom in the development of machinery, saving manpower and truly reflecting the upgrade of modern management methods.

[0004] Unmanned driving can realize operations in all stages from warehousing, transportation, operation, and returning to the site, while taking into account the authority settings of manned and unmanned driving, making the operation of the entire machine more adaptable.

[0005] In response to this demand, there is currently a lack of a braking system that can take into account both manned and unmanned driving modes. Therefore, the existing braking system cannot meet the needs of both manned and unmanned control modes at the same time. Utility Model Content

[0006] In order to solve the above technical problems, the purpose of the utility model is to provide a braking system applied to a tractor and capable of taking into account both manned and unmanned driving modes.

[0007] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows: an electro-hydraulic brake system for a tractor, comprising a brake terminal assembly, a foot brake valve group, an electrically controlled brake valve group, a shuttle valve assembly, a pressure oil source and an oil pot, the electrically controlled brake valve group, the pressure oil source and the shuttle valve assembly constitute an electrically controlled brake oil circuit, the foot brake valve group, the oil pot and the shuttle valve assembly constitute a foot brake oil circuit, the brake terminal assembly is connected to the electrically controlled brake oil circuit, and the foot brake oil circuit is connected to the electrically controlled brake oil circuit through the shuttle valve assembly.

[0008] The beneficial effect of the utility model is that by separately arranging a foot brake valve group and an electric control brake valve group, both of which respectively perform manual control and electric control on the brake terminal assembly, thereby realizing manual mode and electric control mode braking of the brake terminal assembly.

[0009] On the basis of the above technical solution, the present invention can also be improved as follows.

[0010] Further, the foot brake valve group includes a left foot brake valve and a right foot brake valve, the oil inlet of the left foot brake valve is connected to the oil outlet of the oil pot, the oil outlet of the left foot brake valve is connected to the oil inlet of the shuttle valve assembly, the oil inlet of the right foot brake valve is connected to the oil outlet of the oil pot, and the oil outlet of the right foot brake valve is connected to the oil inlet of the shuttle valve assembly.

[0011] The above technical solution divides the foot brake valve group into a left foot brake valve and a right foot brake valve, so that during manual braking, braking can be performed respectively according to the left and right feet of the user.

[0012] Further, the electrically controlled brake valve group includes a left electrically controlled valve and a right electrically controlled valve, both of which are two-position three-way valves, the oil inlet of the left electrically controlled valve is connected to the pressure oil source, the oil inlet of the right electrically controlled valve is connected to the oil outlet of the pressure oil source, the two oil outlets of the left electrically controlled valve are respectively connected to the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source, and the two oil outlets of the right electrically controlled valve are respectively connected to the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source.

[0013] The above technical solution provides a left electric control valve and a right electric control valve in the electric control brake valve group, so that during electric control braking, the left foot brake and the right foot brake can be braked separately according to actual braking needs.

[0014] Further, the shuttle valve assembly includes a first shuttle valve and a second shuttle valve, the first shuttle valve and the second shuttle valve are respectively provided with two oil inlets, the two oil inlets of the first shuttle valve are respectively connected to the oil outlet of the left foot brake valve and the oil outlet of the left electric control valve, the two oil inlets of the second shuttle valve are respectively connected to the oil outlet of the right foot brake valve and the oil outlet of the right electric control valve, and the oil outlets of the first shuttle valve and the second shuttle valve are respectively connected to the brake terminal assembly.

[0015] The above technical solution aims to achieve the switching of the foot brake oil circuit and the electronically controlled brake oil circuit by respectively providing a first shuttle valve and a second shuttle valve and utilizing the two to connect the foot brake oil circuit and the electronically controlled brake oil circuit.

[0016] Further, the brake terminal assembly includes a left foot brake and a right foot brake, the left foot brake is communicated with the oil outlet of the first shuttle valve, and the right foot brake is communicated with the oil outlet of the second shuttle valve.

[0017] The above technical solution realizes independent braking on different sides of the braking system by providing a left foot brake and a right foot brake, so as to improve the braking performance.

[0018] Furthermore, the oil inlet of the right electric control valve is connected to the pipeline between the oil inlet of the left electric control valve and the oil outlet of the pressure oil source, and the oil outlet of the left electric control valve is connected to the pipeline between the oil outlet of the right electric control valve and the oil inlet of the pressure oil source.

[0019] The above technical solution achieves the purpose of electronically controlled braking by controlling the left electronically controlled valve and the right electronically controlled valve and utilizing them to control the oil circuit.

[0020] Furthermore, the pressure oil source includes an oil tank and an oil pump, the oil inlet of the oil pump is connected to the oil outlet of the oil tank, and the oil outlet of the oil pump is connected to the oil inlets of the left and right electric control valves respectively.

[0021] The above technical solution is to set up an oil tank and an oil pump, and use the oil pump to provide power for the pressure oil inside the oil tank, so that it can build up pressure and circulate in the oil circuit.

[0022] Furthermore, it also includes a pressure-building oil circuit, which includes a back-pressure valve, and the oil inlet and the oil outlet of the back-pressure valve are respectively connected to the oil outlet and the oil inlet of the pressure oil source.

[0023] The above technical solution sets up a pressure-building oil circuit, and when the electronically controlled brake valve group is not energized, the oil inside the pressure oil source can circulate in the pressure-building oil circuit, thereby building up pressure.

[0024] Furthermore, the oil inlet of the back pressure valve is connected to the pipeline between the oil inlet of the left electric control valve and the oil outlet of the pressure oil source, and the oil outlet of the back pressure valve is connected to the pipeline between the oil outlet of the right electric control valve and the oil inlet of the pressure oil source.

[0025] The above technical solution sets a back pressure valve. In the initial state when no braking operation is performed, the pressure oil inside the pressure oil source is opened and closed unidirectionally by the back pressure valve, thereby achieving unidirectional circulation of the pressure oil inside the pressure oil source when no braking operation is performed.

[0026] The second purpose of the utility model is to provide a tractor which has both manual control braking and electric control braking modes.

[0027] In order to achieve the above-mentioned purpose, the technical solution of the utility model is as follows: a tractor includes an electro-hydraulic brake system for the tractor.

[0028] The above technical solution installs an electro-hydraulic brake system that can take into account both the manual control mode and the electric control mode in the tractor, so that the tractor can perform manual braking or unmanned electric braking according to different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the initial state in the embodiment of the utility model;

[0030] Figure 2 It is a schematic diagram of the left foot braking state in the manual mode in an embodiment of the present utility model;

[0031] Figure 3 It is a schematic diagram of the left and right foot braking states of the manual mode in an embodiment of the utility model;

[0032] Figure 4 It is a schematic diagram of the left brake state of the electric control mode in the embodiment of the utility model;

[0033] Figure 5 It is a schematic diagram of the left and right braking states of the electronic control mode in an embodiment of the utility model.

[0034] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0035] 1. Pressure oil source; 2. Electric-controlled brake valve group; 2.1. Back-pressure valve; 2.2. Left electric-controlled valve; 2.3. Right electric-controlled valve; 2.4. First shuttle valve; 2.5. Second shuttle valve; 3. Left foot brake; 4. Right foot brake; 5. Foot brake valve group; 5.1. Left foot brake valve; 5.2. Right foot brake valve; 6. Oil pot. DETAILED DESCRIPTION

[0036] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0037] Example

[0038] like Figure 1-5 As shown, an electro-hydraulic brake system for a tractor comprises a brake terminal assembly, a foot brake valve group 5, an electric control brake valve group 2, a shuttle valve assembly, a pressure oil source 1 and an oil pot 6, the electric control brake valve group 2, the pressure oil source 1 and the shuttle valve assembly form an electric control brake oil circuit, the foot brake valve group 5, the oil pot 6 and the shuttle valve assembly form a foot brake oil circuit, the brake terminal assembly is connected to the electric control brake oil circuit, and the foot brake oil circuit is connected to the electric control brake oil circuit through the shuttle valve assembly;

[0039] When manual braking is required, the foot brake valve group 5 is opened and the electric control brake valve group 2 is closed, and the pressure oil in the oil tank 6 enters the brake terminal assembly through the foot brake oil circuit, and the brake terminal assembly starts braking;

[0040] When electric control braking is required, the foot brake valve group 5 is closed and the electric control brake valve group 2 is opened, and the pressure oil in the pressure oil source 1 enters the brake terminal assembly through the electric control brake oil circuit, and the brake terminal assembly starts braking.

[0041] The working principle is: when in manual mode, by controlling the foot brake valve group 5 to open and communicate with the brake terminal assembly, the pressure inside the oil pot 6 enters the brake terminal assembly through the foot brake valve group 5, enabling braking;

[0042] When in the electric control braking mode, the electric control braking valve group 2 is opened and connected to the brake terminal assembly, and the pressure oil in the pressure oil source 1 enters the brake terminal assembly through the electric control braking valve group 2, so that braking can be performed.

[0043] The above technical solution realizes manual and electronically controlled braking of the brake terminal assembly by respectively setting up a foot brake valve group 5 and an electronically controlled brake valve group 2, which respectively perform manual and electronic control on the brake terminal assembly.

[0044] Preferably, the foot brake valve group 5 includes a left foot brake valve 5.1 and a right foot brake valve 5.2, the oil inlet of the left foot brake valve 5.1 is connected to the oil outlet of the oil pot 6, the oil outlet of the left foot brake valve 5.1 is connected to the oil inlet of the shuttle valve assembly, the oil inlet of the right foot brake valve 5.2 is connected to the oil outlet of the oil pot 6, and the oil outlet of the right foot brake valve 5.2 is connected to the oil inlet of the shuttle valve assembly.

[0045] The working principle is as follows: in the manual control mode, when the left foot is required to brake, the left foot brake valve 5.1 is energized and opened, and the pressure oil in the oil tank 6 passes through the left foot brake valve 5.1 and reaches the brake terminal assembly along the foot brake oil path, thereby achieving the braking of the brake terminal assembly;

[0046] In the manual control mode, when the right foot needs to be braked, the right foot brake valve 5.2 is energized and opened, and the pressure oil in the oil tank 6 passes through the right foot brake valve 5.2 and reaches the brake terminal assembly along the foot brake oil circuit, thereby achieving braking of the brake terminal assembly.

[0047] The above technical solution divides the foot brake valve group 5 into a left foot brake valve 5.1 and a right foot brake valve 5.2, so that during manual braking, braking can be performed according to the left and right feet of the user respectively.

[0048] Preferably, the electrically-controlled brake valve group 2 includes a left electrically-controlled valve 2.2 and a right electrically-controlled valve 2.3, both of which are two-position three-way valves, the oil inlet of the left electrically-controlled valve 2.2 being connected to the pressure oil source 1, the oil inlet of the right electrically-controlled valve 2.3 being connected to the oil outlet of the pressure oil source 1, the two oil outlets of the left electrically-controlled valve 2.2 being connected to the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source 1, respectively, and the two oil outlets of the right electrically-controlled valve 2.3 being connected to the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source 1, respectively.

[0049] The working principle is: in the electric control mode, when the left foot brake 3 is braked, the left electric control valve 2.2 is energized and opened, as shown in the attached manual. Figure 3 As shown, the pressure oil flows out from the pressure oil source 1P port, passes through the left electric control valve 2.2, and finally enters the left foot brake 3 along the oil path to complete the braking;

[0050] In the electric control mode, when the right foot brake 4 is braked, the right electric control valve 2.3 is energized and opened, and the pressure oil flows out from the pressure oil source 1P port, passes through the right electric control valve 2.3, and finally enters the right foot brake 4 along the oil path to complete the braking;

[0051] In the electric control mode, when the left foot brake 3 and the right foot brake 4 are braked at the same time, as shown in the attached manual Figure 4 As shown, since the left foot brake and the right foot brake are independently set, the left electric control valve 2.2 and the right electric control valve 2.3 are opened at the same time and the left foot brake 3 and the right foot brake 4 can be braked simultaneously.

[0052] The above technical solution provides a left electric control valve and a right electric control valve in the electric control brake valve group, so that during electric control braking, the left foot brake and the right foot brake can be braked separately according to actual braking needs.

[0053] Preferably, the shuttle valve assembly includes a first shuttle valve 2.4 and a second shuttle valve 2.5, and the first shuttle valve 2.4 and the second shuttle valve 2.5 are respectively provided with two oil inlets, the two oil inlets of the first shuttle valve 2.4 are respectively connected to the oil outlet of the left foot brake valve 5.1 and the oil outlet of the left electric control valve 2.2, the two oil inlets of the second shuttle valve 2.5 are respectively connected to the oil outlet of the right foot brake valve 5.2 and the oil outlet of the right electric control valve 2.3, and the oil outlets of the first shuttle valve 2.4 and the second shuttle valve 2.5 are respectively connected to the brake terminal assembly.

[0054] The working principle is as follows: in the manual control mode, when the left foot is required to brake, the pressure oil passes through the left foot brake valve 5.1 and enters the first shuttle valve 2.4. The first shuttle valve 2.4 is actuated, and the pressure oil passes through the first shuttle valve 2.4 to reach the brake terminal assembly, thereby realizing independent control braking;

[0055] In the manual control mode, when the right foot is required to brake, the pressure oil passes through the right foot brake valve 5.2 and enters the second shuttle valve 2.5. The second shuttle valve 2.5 is actuated, and the pressure oil passes through the second shuttle valve 2.5 to reach the brake terminal assembly, thereby realizing independent control braking.

[0056] The above technical solution aims to achieve the switching of the foot brake oil circuit and the electric control brake oil circuit by respectively providing the first shuttle valve 2.4 and the second shuttle valve 2.5 and using the two to connect the foot brake oil circuit and the electric control brake oil circuit.

[0057] Preferably, the brake terminal assembly comprises a left foot brake 3 and a right foot brake 4, the left foot brake 3 is communicated with the oil outlet of the first shuttle valve 2.4, and the right foot brake 4 is communicated with the oil outlet of the second shuttle valve 2.3.

[0058] The working principle is: in the manual control mode, when the left foot is required to brake, as shown in the attached manual Figure 2 As shown, the left foot brake valve 5.1 is energized and opened, and the pressure oil in the oil tank 6 flows out through the left foot brake valve 5.1 to L0, and reaches the brake terminal assembly along the oil path, thereby achieving the braking of the left foot brake 3;

[0059] In the manual control mode, when the right foot needs to be braked, the right foot brake valve 5.2 is energized and opened, and the pressure oil in the oil tank 6 flows out through the right foot brake valve 5.2 to R0, and reaches the brake terminal assembly along the oil path, thereby achieving the braking of the right foot brake 4;

[0060] In manual control mode, when you need to brake both left and right feet at the same time, as shown in the attached manual, Figure 2 As shown, the above-mentioned left and right foot braking modes are controlled independently of each other, so opening the left foot brake valve 5.1 and the right foot brake valve 5.2 at the same time can realize simultaneous braking of both feet.

[0061] The above technical solution realizes independent braking on different sides of the braking system by providing a left foot brake and a right foot brake, so as to improve the braking performance.

[0062] Preferably, the oil inlet of the right electric control valve 2.3 is connected to the pipeline between the oil inlet of the left electric control valve 2.2 and the oil outlet of the pressure oil source 1, and the oil outlet of the left electric control valve 2.2 is connected to the pipeline between the oil outlet of the right electric control valve 2.3 and the oil inlet of the pressure oil source 1.

[0063] Among them, the two oil outlets of the left electric control valve 2.2 are respectively the first left oil outlet and the second left oil outlet, the first left oil outlet is connected to the oil inlet of the first shuttle valve 2.4, and the second left oil outlet is connected to the pipeline between the oil outlet of the right electric control valve 2.3 and the oil inlet of the pressure oil source 1.

[0064] Among them, the two oil outlets of the right electric control valve 2.3 are respectively the first right oil outlet and the second right oil outlet, the first right oil outlet is connected to the oil inlet of the second shuttle valve 2.5, and the second right oil outlet is connected to the pipeline between the oil outlet of the left electric control valve 2.2 and the oil inlet of the pressure oil source 1.

[0065] The working principle is as follows: in the electric control mode, the pressure oil enters the left foot brake through the first left oil outlet. After the left foot brake 3 is braked, the left electric control valve 2.2 becomes de-energized again. At this time, the pressure oil of the left foot brake flows back into the left electric control valve 2.2, flows back into the pipeline between the oil outlet of the right electric control valve 2.3 and the oil inlet of the pressure oil source 1 through the second left oil outlet, and finally flows back into the pressure oil source 1 through the T2 port;

[0066] In the electric control mode, the pressure oil enters the right foot brake through the first right oil outlet. After the right foot brake 3 is braked, the right electric control valve 2.3 becomes unpowered again. At this time, the pressure oil of the right foot brake flows back into the right electric control valve 2.3, and then flows back through the second right oil outlet into the pipeline between the oil outlet of the left electric control valve 2.2 and the oil inlet of the pressure oil source 1, and finally flows back into the pressure oil source 1 through the T2 port.

[0067] The above technical solution connects the oil outlets of the left electric control valve 2.2 and the right electric control valve 2.3 with the pressure oil source 1, so that the pressure oil can flow back into the pressure oil source after braking, thereby circulating.

[0068] Preferably, the pressure oil source 1 comprises an oil tank and an oil pump, the oil inlet of the oil pump is connected to the oil outlet of the oil tank, and the oil outlet of the oil pump is connected to the oil inlets of the left electric control valve 2.2 and the right electric control valve 2.3 respectively.

[0069] The working principle is: when the pressure oil needs to be output, the oil pump draws the pressure oil from the inside of the oil tank and pumps it into the oil circuit, thereby providing driving force for the entire oil circuit.

[0070] The above technical solution is to set up an oil tank and an oil pump, and use the oil pump to provide power for the pressure oil inside the oil tank, so that it can build up pressure and circulate in the oil circuit.

[0071] Preferably, a pressure-building oil circuit is further included, and the pressure-building oil circuit includes a back-pressure valve 2.1, and the oil inlet and the oil outlet of the back-pressure valve 2.1 are respectively connected to the oil outlet and the oil inlet of the pressure oil source 1.

[0072] The working principle is: when the left electric control valve 2.2 and the right electric control valve 2.3 are both not energized, the pressure oil, under the action of the oil pump, passes through the pressure-building oil circuit and circulates, thereby building up pressure for the entire oil circuit.

[0073] The above technical solution sets up a pressure-building oil circuit. When the electronically controlled brake valve group 2 is not energized, the oil inside the pressure oil source can circulate in the pressure-building oil circuit, thereby building up pressure.

[0074] Preferably, the oil inlet of the back pressure valve 2.1 is connected to the pipeline between the oil inlet of the left electric control valve 2.2 and the oil outlet of the pressure oil source 1, and the oil outlet of the back pressure valve 2.1 is connected to the pipeline between the oil outlet of the right electric control valve 2.3 and the oil inlet of the pressure oil source 1.

[0075] The working principle is: when the left electric control valve 2.2 and the right electric control valve 2.3 are both not energized, the pressure oil flows out from the P port of the pressure oil source 1, passes through the back pressure valve 2.1, flows out from the T2 port, and returns to the pressure oil source 1.

[0076] The above technical solution sets a back pressure valve 2.1. In the initial state when no braking operation is performed, the pressure oil in the pressure oil source 1 is opened and closed unidirectionally by the back pressure valve 2.1, thereby achieving unidirectional circulation of the pressure oil in the pressure oil source 1 when no braking operation is performed.

[0077] Preferably, a tractor comprises an electro-hydraulic brake system for the tractor.

[0078] The working principle is: by transferring the electro-hydraulic brake system that can have both manual control mode and electronic control mode into the tractor, the tractor can be driven in two modes: unmanned or manned.

[0079] The above technical solution installs an electro-hydraulic brake system that can take into account both the manual control mode and the electric control mode in the tractor, so that the tractor can perform manual braking or unmanned electric braking according to different working conditions.

[0080] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0081] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0085] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An electro-hydraulic brake system for a tractor, characterized in that: The invention comprises a brake terminal assembly, a foot brake valve group (5), an electric control brake valve group (2), a shuttle valve assembly, a pressure oil source (1) and an oil pot (6), wherein the pressure oil source (1) is connected to the electric control brake valve group (2), the electric control brake valve group (2) is connected to the brake terminal assembly via the shuttle valve assembly, and an electric control brake oil circuit is formed; the oil pot (6) is connected to the foot brake valve group (5), the foot brake valve group (5) is connected to the shuttle valve assembly, and a foot brake oil circuit is formed.

2. The electro-hydraulic brake system for a tractor according to claim 1, characterized in that: The foot brake valve assembly (5) comprises a left foot brake valve (5.1) and a right foot brake valve (5.2); the oil inlet of the left foot brake valve (5.1) is communicated with the oil outlet of the oil pot (6); the oil outlet of the left foot brake valve (5.1) is communicated with the oil inlet of the shuttle valve assembly; the oil inlet of the right foot brake valve (5.2) is communicated with the oil outlet of the oil pot (6); and the oil outlet of the right foot brake valve (5.2) is communicated with the oil inlet of the shuttle valve assembly.

3. The electro-hydraulic brake system for a tractor according to claim 2, characterized in that: The electrically controlled brake valve group (2) comprises a left electrically controlled valve (2.2) and a right electrically controlled valve (2.3); both the left electrically controlled valve (2.2) and the right electrically controlled valve (2.3) are two-position three-way valves; the oil inlet of the left electrically controlled valve (2.2) is in communication with the pressure oil source (1); the oil inlet of the right electrically controlled valve (2.3) is in communication with the oil outlet of the pressure oil source (1); the two oil outlets of the left electrically controlled valve (2.2) are in communication with the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source (1), respectively; the two oil outlets of the right electrically controlled valve (2.3) are in communication with the oil inlet of the shuttle valve assembly and the oil inlet of the pressure oil source (1), respectively.

4. The electro-hydraulic brake system for a tractor according to claim 3, characterized in that: The shuttle valve assembly comprises a first shuttle valve (2.4) and a second shuttle valve (2.5), wherein the first shuttle valve (2.4) and the second shuttle valve (2.5) are respectively provided with two oil inlets, wherein the two oil inlets of the first shuttle valve (2.4) are respectively connected to the oil outlet of the left foot brake valve (5.1) and the oil outlet of the left electric control valve (2.2), wherein the two oil inlets of the second shuttle valve (2.5) are respectively connected to the oil outlet of the right foot brake valve (5.2) and the oil outlet of the right electric control valve (2.3), and the oil outlets of the first shuttle valve (2.4) and the second shuttle valve (2.5) are respectively connected to the brake terminal assembly.

5. The electro-hydraulic brake system for a tractor according to claim 4, characterized in that: The brake terminal assembly comprises a left foot brake (3) and a right foot brake (4); the left foot brake (3) is communicated with the oil outlet of the first shuttle valve (2.4); and the right foot brake (4) is communicated with the oil outlet of the second shuttle valve (2.5).

6. The electro-hydraulic brake system for a tractor according to claim 5, characterized in that: The oil inlet of the right electric control valve (2.3) is connected to the pipeline between the oil inlet of the left electric control valve (2.2) and the oil outlet of the pressure oil source (1), and the oil outlet of the left electric control valve (2.2) is connected to the pipeline between the oil outlet of the right electric control valve (2.3) and the oil inlet of the pressure oil source (1).

7. The electro-hydraulic brake system for a tractor according to claim 6, characterized in that: The pressure oil source (1) comprises an oil tank and an oil pump, the oil inlet of the oil pump is connected to the oil outlet of the oil tank, and the oil outlet of the oil pump is respectively connected to the oil inlets of the left electric control valve (2.2) and the right electric control valve (2.3).

8. An electro-hydraulic brake system for a tractor according to any one of claims 3 to 7, characterized in that: It also comprises a pressure-building oil circuit, the pressure-building oil circuit comprising a back-pressure valve (2.1), the oil inlet and the oil outlet of the back-pressure valve (2.1) being respectively connected to the oil outlet and the oil inlet of the pressure oil source (1).

9. The electro-hydraulic brake system for a tractor according to claim 8, characterized in that: The oil inlet of the back pressure valve (2.1) is connected to the pipeline between the oil inlet of the left electric control valve (2.2) and the oil outlet of the pressure oil source (1), and the oil outlet of the back pressure valve (2.1) is connected to the pipeline between the oil outlet of the right electric control valve (2.3) and the oil inlet of the pressure oil source (1).

10. A tractor, characterized in that: It comprises an electro-hydraulic brake system for a tractor according to any one of claims 1-9.

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