Hydraulic control valve group for tractor and tractor

Abstract

The utility model provides a hydraulic control valve set for a tractor and the tractor, and relates to the technical field of hydraulic pressure. According to the hydraulic control valve set for the tractor, compared with the prior art, the reversing functions of the reversing valves arranged on all the flow dividing loops in the prior art are unified to the main loop formed by the first path, the second path, the third path and the fourth path, and the cut-off assembly is used for controlling opening and closing of the single flow dividing loop; when a single shunting loop is opened, other shunting loops do not interfere with the opened shunting loop due to the bidirectional cut-off effect. Therefore, the redundancy complexity of the hydraulic control valve bank for the tractor is effectively reduced, the complexity of an electrical control system matched with the hydraulic control valve bank for the tractor is reduced, the structure of the hydraulic control valve bank for the tractor is simplified, and the cost is saved.

Description

Technical Field

[0001] The present application relates to the field of hydraulic technology, and in particular to a hydraulic control valve group for a tractor and a tractor. Background Art

[0002] A tractor usually has corresponding driving facilities for the agricultural implements it carries. Such driving facilities are usually hydraulic driving structures. For various actions of the agricultural implements, a hydraulic multi-way valve is usually used to provide hydraulic actions for the agricultural implements. That is, there are multiple oil circuits in the hydraulic driving structure, and each oil circuit is provided with a corresponding reversing valve (usually three-position four-way). By switching the valves, multiple hydraulic driving sources are provided for the agricultural implements.

[0003] The principles of each control in a hydraulic multi-way valve are similar. The existing technology meets the needs of multi-way control by simply duplicating the principles of each path. Simple duplication adds corresponding reversing valves, which is redundant and complex from a technical perspective. Moreover, for the electric-controlled multi-way valve of the existing technology, for each additional path, two control points are added to the subsequent electrical control system, which makes the control of the electrical control system cumbersome. Utility Model Content

[0004] In view of this, the present application provides a hydraulic control valve group for a tractor and a tractor, the purpose of which is to solve the above technical problems to a certain extent.

[0005] In a first aspect, the present application provides a hydraulic control valve group for a tractor, the hydraulic control valve group for a tractor comprising:

[0006] a first path and a second path, wherein the first path and the second path are used for circulating a pressure medium and a reflux medium, respectively;

[0007] a reversing valve, the reversing valve comprising a first valve port, a second valve port, a third valve port and a fourth valve port, the first path and the second path being in communication with the first valve port and the second valve port respectively, the reversing valve having a valve core, and the reversing valve being configured to have a first position for delivering the pressure medium to the third valve port and a second position for delivering the pressure medium to the fourth valve port;

[0008] a third path and a fourth path, wherein the third path and the fourth path are communicated with the third valve port and the fourth valve port respectively;

[0009] A plurality of shunt circuits, the shunt circuits comprising a first shunt path and a second shunt path, the first shunt path being in communication with the third path, the second shunt path being in communication with the fourth path, the first shunt path being in communication with a first liquid port of an external device, the second shunt path being in communication with a second liquid port of the external device;

[0010] A plurality of cut-off components, the plurality of cut-off components are arranged in one-to-one correspondence with the plurality of shunt circuits, the cut-off components include a first cut-off portion and a second cut-off portion, the first cut-off portion and the second cut-off portion are both arranged in one of the first shunt path and the second shunt path, and the first cut-off portion and the second cut-off portion are configured to cooperate together to bidirectionally cut off the shunt circuit;

[0011] The cut-off component further includes a communication path, which is provided corresponding to the first cut-off portion and the second cut-off portion, and is configured to be switchable with the first cut-off portion and the second cut-off portion to conduct one of them.

[0012] Preferably, the first cut-off portion and the second cut-off portion are disposed in the same one of the first shunt path and the second shunt path;

[0013] The cut-off assembly comprises a two-position, two-way, two-way cut-off valve, the first cut-off portion and the second cut-off portion are both arranged inside the two-position, two-way, two-way cut-off valve, and the communication path is arranged inside the two-position, two-way, two-way cut-off valve.

[0014] Preferably, at least one of the plurality of shunt circuits has a plurality of first shunt paths;

[0015] The number of the two-position two-way two-way stop valves corresponds one-to-one to the number of the first flow diversion paths;

[0016] The plurality of first flow diversion paths include the following first flow diversion path: a communication path included in a two-position, two-way, two-way stop valve arranged on the first flow diversion path is configured as a throttling path.

[0017] Preferably, the first flow diversion path where the two-position, two-way, two-way stop valve having the throttling path is located is communicated with another first flow diversion path.

[0018] Preferably, the first cut-off portion and the second cut-off portion are respectively arranged on the first shunt path and the second shunt path;

[0019] Wherein, the cut-off assembly comprises a first two-position two-way valve and a second two-position two-way valve, the first cut-off portion is arranged inside the first two-position two-way valve, and the second cut-off portion is arranged inside the second two-position two-way valve;

[0020] Wherein, the connecting path includes a first connecting part and a second connecting part, the first connecting part is arranged inside the first two-position two-way valve, and is used to switch the first cut-off part to conduct the first diversion path, and the second connecting part is arranged inside the second two-position two-way valve, and is used to switch the second cut-off part to conduct the second diversion path.

[0021] Preferably, the reversing valve is configured as a manual reversing valve.

[0022] Preferably, the reversing valve is configured to be driven by a driving structure.

[0023] Preferably, the reversing valve is configured to be driven by an electromagnetic structure or the reversing valve is driven by a motor.

[0024] Preferably, the valve core of the reversing valve further has a third position between the first position and the second position, and the valve core is configured to connect the first valve port and the second valve port in the third position to connect the first path and the second path.

[0025] In a second aspect, the present application provides a tractor, comprising the tractor hydraulic control valve group as described above.

[0026] According to the tractor hydraulic control valve group provided by the embodiment of the present application, compared with the prior art, the reversing function of the reversing valves set on each shunt circuit in the prior art is unified to the main circuit formed by the first to fourth paths, and the cut-off component is used to control the opening and closing of a single shunt circuit. When a single shunt circuit is opened, other shunt circuits do not interfere with the already opened shunt circuit due to the two-way cut-off effect. As a result, the redundant complexity of the tractor hydraulic control valve group is effectively reduced, the complexity of the electrical control system of the tractor hydraulic control valve group is reduced, the structure of the tractor hydraulic control valve group is simplified, and it is conducive to cost saving.

[0027] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1A schematic diagram showing a principle diagram of a hydraulic control valve group for a tractor provided according to an embodiment of the present application;

[0030] Figure 2 A schematic diagram showing another principle diagram of a hydraulic control valve group for a tractor provided according to an embodiment of the present application;

[0031] Figure 3 A schematic diagram showing a portion of another schematic diagram of a hydraulic control valve group for a tractor provided according to an embodiment of the present application.

[0032] Reference numerals:

[0033] 10 - first path; 20 - second path; 30 - third path; 40 - fourth path; 50 - first diversion path; 60 - second diversion path; 70 - reversing valve; 80 - two-position two-way two-way stop valve; 91 - first two-position two-way valve; 92 - second two-position two-way valve. DETAILED DESCRIPTION

[0034] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application 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 limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0038] According to a first aspect of an embodiment of the present application, a hydraulic control valve group for a tractor is provided. Figure 1 and Figure 2 The structure and working principle of the hydraulic control valve group for tractors are described in detail.

[0039] In an embodiment, a hydraulic control valve group for a tractor provided according to an embodiment of the present application includes a first path 10, a second path 20, a reversing valve 70, a third path 30, a fourth path 40, a plurality of shunt circuits, and a plurality of cut-off components. In an embodiment, the first path 10 and the second path 20 are used for circulating a pressure medium and a reflux medium, respectively. The reversing valve 70 includes a first valve port, a second valve port, a third valve port, and a fourth valve port. The first path 10 and the second path 20 are connected to the first valve port and the second valve port, respectively. The reversing valve 70 has a valve core. The reversing valve 70 is configured to have a first position for delivering the pressure medium to the third valve port and a second position for delivering the pressure medium to the fourth valve port. The third path 30 and the fourth path 40 are connected to the third valve port and the fourth valve port, respectively.

[0040] In an embodiment, the shunt circuit includes a first shunt path 50 and a second shunt path 60, the first shunt path 50 is connected to the third path 30, the second shunt path 60 is connected to the fourth path 40, the first shunt path 50 is used to communicate with a first liquid port of an external device, and the second shunt path 60 is used to communicate with a second liquid port of an external device.

[0041] In an embodiment, the above-mentioned multiple cut-off components are arranged one-to-one corresponding to the above-mentioned multiple shunt circuits, and the cut-off components include a first cut-off portion and a second cut-off portion, and the first cut-off portion and the second cut-off portion are both arranged in one of the first shunt path 50 and the second shunt path 60, and the first cut-off portion and the second cut-off portion are configured to cooperate together to form a bidirectional cut-off shunt circuit.

[0042] In an embodiment, the cut-off assembly further includes a communication path, which is provided corresponding to the first cut-off portion and the second cut-off portion, and the communication path is configured to be switchable with the first cut-off portion and the second cut-off portion to conduct one of them.

[0043] In this way, according to the hydraulic control valve group for a tractor provided in the embodiment of the present application, the first path 10, the second path 20, the third path 30 and the fourth path 40 substantially form a main circuit, and the reversing valve 70 is arranged on the main circuit formed by these four paths. By switching the valve core between the first position and the second position, the third path 30 can flow the pressure medium, and the corresponding fourth path 40 can reflux the medium, and the third path 30 can converge the medium, and the corresponding fourth path 40 can flow the pressure medium, that is, the switching of the pressure medium between the third path 30 and the fourth path 40 is realized.

[0044] On this basis, when the diversion circuit is diverted from the above-mentioned main circuit, as the pressure medium switches between the third path 30 and the fourth path 40, the pressure medium can flow to the first diversion path 50, and then flow to the inside of the external device to drive the external device, and then the return medium flows back to the second diversion path 60, and the pressure medium can flow to the second diversion path 60, and then flow to the inside of the external device to drive the external device, and then the return medium flows back to the first diversion path 50.

[0045] According to the hydraulic control valve group for tractors provided in the embodiment of the present application, the first cut-off part and the second cut-off part of the two-way cut-off cooperate with each other through the cut-off component. When the communication path of a shunt circuit among the multiple shunt circuits is switched with the corresponding first cut-off part and the second cut-off part, the shunt circuit is connected, and the external device connected to the shunt circuit is driven to perform an action. When the reversing valve 70 performs a reversing operation, the external device correspondingly performs an action opposite to the aforementioned action. Due to the two-way cut-off effect of the cut-off component on other shunt circuits, the pressure medium will not flow to the external device corresponding to other shunt circuits, and the medium in the external device will not flow back into the shunt circuit, so that the shunt circuits affect each other.

[0046] Therefore, according to the tractor hydraulic control valve group provided by the embodiment of the present application, compared with the prior art, the reversing function of the reversing valve 70 set on each shunt circuit in the prior art is unified to the main circuit of the tractor hydraulic control valve group as above, and the cut-off component is used to control the opening and closing of a single shunt circuit. When a single shunt circuit is opened, other shunt circuits do not interfere with the already opened shunt circuit due to the two-way cut-off effect. Therefore, the redundant complexity of the tractor hydraulic control valve group is effectively reduced, the complexity of the electrical control system of the tractor hydraulic control valve group is reduced, the structure of the tractor hydraulic control valve group is simplified, and it is conducive to cost saving.

[0047] In an embodiment, the first cut-off portion and the second cut-off portion in the cut-off assembly may be implemented by a valve core of a valve structure, which will be explained in detail in the subsequent description.

[0048] In an embodiment, the first path 10 , the second path 20 , the third path 30 , and the fourth path 40 mentioned above, together with the first branch flow path 50 and the second branch flow path 60 mentioned in the above description, may all be, for example, pipelines.

[0049] In an embodiment, the medium may be hydraulic oil, that is, the pressure medium is pressure oil, such as pressure oil drawn and pressurized from a hydraulic oil storage tank by a hydraulic pump, and the return medium is return hydraulic oil, that is, hydraulic oil that has substantially done work.

[0050] In an embodiment, the external implement may be, for example, an agricultural implement, and the hydraulic port of the agricultural implement is used for hydraulic oil to flow into, so that the agricultural implement is driven by the hydraulic oil to perform an action.

[0051] According to the tractor hydraulic control valve group provided in the embodiment of the present application, in the embodiment, the first cut-off portion and the second cut-off portion can be arranged in the same one of the first branch path 50 and the second branch path 60. Figure 1 and Figure 2 As shown, the cut-off assembly includes a two-position, two-way, two-way cut-off valve 80 , the first cut-off portion and the second cut-off portion are both arranged inside the two-position, two-way, two-way cut-off valve 80 , and the communication path is arranged inside the two-position, two-way, two-way cut-off valve 80 .

[0052] refer to Figure 1 and Figure 2 , Figure 1 and Figure 2 In the embodiment, the first cut-off portion and the second cut-off portion are both located on the same shunt path, for example, on the first shunt path 50, and no additional components may be provided on the second shunt path 60. Figure 1 and Figure 2 The direction of the first cut-off part and the second cut-off part is schematically indicated by the hydraulic component symbol of "one-way conduction". However, it should be understood that the actual structure of the first cut-off part and the second cut-off part is a two-part structure on the valve core in the two-position two-way two-way stop valve 80 for realizing two-way cut-off. In addition, the communication path is also derived from the common definition of the valve core in the two-position two-way two-way stop valve 80 and the valve housing of the two-position two-way two-way stop valve 80. Through the movement of the valve core in the valve housing, the two-position two-way two-way stop valve 80 switches between the two-way cut-off function and the conduction function.

[0053] According to the tractor hydraulic control valve group provided in the embodiment of the present application, at least one of the plurality of shunt circuits may have a plurality of first shunt paths 50. In the embodiment, the number of the two-position two-way two-way stop valves 80 may correspond to the number of the first shunt paths 50. In the embodiment, Figure 2As shown, the plurality of first flow diversion paths 50 may include the following first flow diversion path 50: the communication path included in the two-position two-way two-way stop valve 80 provided on the first flow diversion path 50 is configured as a throttling path.

[0054] In this way, according to the hydraulic control valve group for tractors provided in the embodiment of the present application, when at least one of the above-mentioned shunt circuits is working, it is possible to consider bidirectionally shutting off other first shunt paths 50 and opening one of the first shunt paths 50. When the two-position, two-way, two-way shut-off valve 80 provided for the opened first shunt path 50 also has a throttling function (that is, when the connecting path referred to above is configured as a throttling path), the flow of the hydraulic oil flowing through the first shunt path 50 is throttled, thereby reducing the flow of the hydraulic oil output to the external device by switching to the opening of the first shunt path 50.

[0055] It should be noted that, in this example, the external device includes liquid ports corresponding to the number of paths of the at least one shunt circuit, that is, it may include, for example, a second liquid port, and a plurality of first liquid ports whose number is the same as the first shunt path 50 and which are connected one-to-one.

[0056] According to the hydraulic control valve group for tractors provided in the embodiment of the present application, in the embodiment, as an example, Figure 2 As shown, the first flow branching path 50 where the two-position two-way two-way stop valve 80 having a throttling path is located can be communicated with another first flow branching path 50 .

[0057] According to the tractor hydraulic control valve group provided in the embodiment of the present application, in a different Figure 1 and Figure 2 In the example, for example Figure 3 In the example given, the first cutoff portion and the second cutoff portion may be provided on the first branch flow path 50 and the second branch flow path 60 , respectively.

[0058] Specifically, see Figure 3 , in essence, two cut-off parts are respectively corresponding to two two-position two-way valves, wherein one two-position two-way valve cuts off one direction, and the other two-position two-way valve cuts off the other direction. In the embodiment, the two two-position connecting valves may be, for example, a first two-position two-way valve 91 and a second two-position two-way valve 92, wherein the first cut-off part is arranged inside the first two-position two-way valve 91, and the second cut-off part is arranged inside the second two-position two-way valve 92. Similar to the above description, the first cut-off part and the second cut-off part here are the cut-off structure on the valve core of the first two-position two-way valve 91 and the cut-off structure on the valve core of the second two-position two-way valve 92, respectively.

[0059] In an embodiment, the connecting path may include a first connecting portion and a second connecting portion. The first connecting portion may be arranged inside a first two-position two-way valve 91 for switching a first cut-off portion to connect a first diversion path 50. The second connecting portion may be arranged inside a second two-position two-way valve 92 for switching a second cut-off portion to connect a second diversion path 60.

[0060] Here, the structures of the first connecting part and the second connecting part are also the same as above. Figure 1 and Figure 2 The connection paths in the examples are the same and will not be repeated here.

[0061] According to the tractor hydraulic control valve group provided in the embodiment of the present application, the reversing valve 70 can be configured as a manual reversing valve 70 (such as Figure 1 ), to allow an operator to perform manual operation and switching, the switching handle of the switching valve 70 can be integrated into a tractor, for example.

[0062] According to the tractor hydraulic control valve group provided in the embodiment of the present application, in other examples, the reversing valve 70 can be configured to be driven by a driving structure. Specifically, the reversing valve 70 can be configured to be driven by an electromagnetic structure (such as Figure 2 As shown, the reversing valve 70 here is substantially formed as a three-position four-way solenoid valve) or the reversing valve 70 is driven by a motor. In the example where the reversing valve 70 is driven by a motor, the motor can be, for example, a stepping motor, and a transmission structure such as a lead screw nut can be used. The stepping motor drives the lead screw to rotate, and the nut sleeved on the lead screw drives the valve core of the reversing valve 70 to move.

[0063] In addition, according to the tractor hydraulic control valve group provided in the embodiment of the present application, the valve core of the reversing valve 70 can also have a third position between the first position and the second position, and the valve core can be configured to connect the first valve port and the second valve port in the third position to connect the first path 10 and the second path 20. Figure 2 As shown, as mentioned in the above description, the reversing valve 70 here is essentially formed as a three-position four-way solenoid valve, and the third position of its valve core is the middle position of the valve. The middle position of the valve is an "H" type middle position, which ensures that the hydraulic pump can continue to pump oil even when none of the diverter paths are connected, because the pressure oil will still flow back to the hydraulic oil storage tank in the middle position of the valve.

[0064] According to the hydraulic control valve group for tractors provided in the embodiment of the present application, a one-way reversing valve 70 is used as the reversing function of the oil ports of the overall multi-way valve, an oil port selection valve (that is, a two-position two-way valve on the first path 10) is used to select the working oil port, and a two-way cut-off function is used to realize the interlocking function of the working of each path.

[0065] According to a second aspect of an embodiment of the present application, a tractor is provided. The tractor includes the above-mentioned hydraulic control valve group for the tractor and also includes the above-mentioned beneficial effects, which will not be repeated here. In addition, the tractor also includes the above-mentioned agricultural machinery.

[0066] The above are only preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. All equivalent structural changes made by using the contents of the present application specification and drawings under the innovative concept of the present application, or directly / indirectly applied in other related technical fields are included in the protection scope of the present application.

Claims

1. A hydraulic control valve group for a tractor, characterized in that: The tractor hydraulic control valve group comprises: a first path and a second path, wherein the first path and the second path are used for circulating a pressure medium and a reflux medium, respectively; a reversing valve, the reversing valve comprising a first valve port, a second valve port, a third valve port and a fourth valve port, the first path and the second path being in communication with the first valve port and the second valve port respectively, the reversing valve having a valve core, and the reversing valve being configured to have a first position for delivering the pressure medium to the third valve port and a second position for delivering the pressure medium to the fourth valve port; a third path and a fourth path, wherein the third path and the fourth path are communicated with the third valve port and the fourth valve port respectively; A plurality of shunt circuits, the shunt circuits comprising a first shunt path and a second shunt path, the first shunt path being in communication with the third path, the second shunt path being in communication with the fourth path, the first shunt path being in communication with a first liquid port of an external device, the second shunt path being in communication with a second liquid port of the external device; A plurality of cut-off components, the plurality of cut-off components are arranged in one-to-one correspondence with the plurality of shunt circuits, the cut-off components include a first cut-off portion and a second cut-off portion, the first cut-off portion and the second cut-off portion are both arranged in one of the first shunt path and the second shunt path, and the first cut-off portion and the second cut-off portion are configured to cooperate together to bidirectionally cut off the shunt circuit; The cut-off component further includes a communication path, which is provided corresponding to the first cut-off portion and the second cut-off portion, and is configured to be switchable with the first cut-off portion and the second cut-off portion to conduct one of them.

2. The hydraulic control valve group for tractors according to claim 1, characterized in that: The first cut-off portion and the second cut-off portion are disposed in the same one of the first flow-dividing path and the second flow-dividing path; The cut-off assembly comprises a two-position, two-way, two-way cut-off valve, the first cut-off portion and the second cut-off portion are both arranged inside the two-position, two-way, two-way cut-off valve, and the communication path is arranged inside the two-position, two-way, two-way cut-off valve.

3. The hydraulic control valve group for tractors according to claim 2, characterized in that: At least one of the plurality of shunt circuits has a plurality of first shunt paths; The number of the two-position two-way two-way stop valves corresponds one-to-one to the number of the first flow diversion paths; The plurality of first flow diversion paths include the following first flow diversion path: a communication path included in a two-position, two-way, two-way stop valve arranged on the first flow diversion path is configured as a throttling path.

4. The hydraulic control valve group for tractors according to claim 3, characterized in that: The first shunt path where the two-position two-way two-way stop valve having the throttling path is located is communicated with another first shunt path.

5. The hydraulic control valve group for tractor according to claim 1, characterized in that: The first cut-off portion and the second cut-off portion are respectively arranged on the first shunt path and the second shunt path; Wherein, the cut-off assembly comprises a first two-position two-way valve and a second two-position two-way valve, the first cut-off portion is arranged inside the first two-position two-way valve, and the second cut-off portion is arranged inside the second two-position two-way valve; Wherein, the connecting path includes a first connecting part and a second connecting part, the first connecting part is arranged inside the first two-position two-way valve, and is used to switch the first cut-off part to conduct the first diversion path, and the second connecting part is arranged inside the second two-position two-way valve, and is used to switch the second cut-off part to conduct the second diversion path.

6. The tractor hydraulic control valve assembly according to any one of claims 1 to 5, characterized in that: The reversing valve is configured as a manual reversing valve.

7. The tractor hydraulic control valve assembly according to any one of claims 1 to 5, characterized in that: The reversing valve is configured to be driven by a driving structure.

8. The hydraulic control valve group for tractor according to claim 7, characterized in that: The reversing valve is configured to be driven by an electromagnetic structure or the reversing valve is driven by a motor.

9. The hydraulic control valve assembly for a tractor according to any one of claims 1 to 5, characterized in that: The valve core of the reversing valve further has a third position between the first position and the second position, and the valve core is configured to connect the first valve port and the second valve port in the third position to connect the first path and the second path.

10. A tractor, characterized in that: The tractor comprises the tractor hydraulic control valve group according to any one of claims 1 to 9.

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