CN221322908U - Control valve structure, hydraulic control system and tractor - Google Patents

Abstract

The utility model provides a control valve structure, a hydraulic control system and a tractor, wherein the control valve structure comprises: a main valve body; the main valve rod is movably arranged in the main flow path in a penetrating way; the bypass valve and the buffer valve are arranged on the second branch flow path at intervals, and the main flow path is communicated with the second branch flow path between the bypass valve and the buffer valve; when the main valve rod is in the blocking position, the inlet valve is closed, the bypass valve is opened, and the buffer valve is closed, so that fluid in the main flow path flows back through the first backflow flow path; when the main valve rod is at the avoidance position, the inlet valve is opened, the bypass valve and the buffer valve are closed, so that fluid in the main flow path flows out through the first communication flow path; when the main valve stem is in the buffer position, the inlet valve and the bypass valve are closed and the buffer valve is opened to allow fluid in the main flow path to flow out through the second return flow path. By the technical scheme provided by the utility model, the technical problem that the impact pressure of the control valve structure in the prior art is larger during position switching can be solved.

Description

Control valve structure, hydraulic control system and tractor

Technical Field

The utility model relates to the technical field of hydraulic control systems, in particular to a control valve structure, a hydraulic control system and a tractor.

Background

At present, the lifting and descending control of the oil cylinder can be realized through a control valve structure in the prior art. Specifically, the oil in the oil cylinder flows out through the control valve structure to realize the descending of the oil cylinder. In the prior art, the state of the oil cylinder is generally changed by changing the structural position of a control valve.

However, the control valve in the prior art is often subjected to a larger impact force in the position switching process, the larger impact force directly acts on the control valve, and the control valve structure is greatly damaged under the long-term action.

Disclosure of utility model

The utility model mainly aims to provide a control valve structure, a hydraulic control system and a tractor, so as to solve the technical problem that the control valve structure in the prior art is subjected to larger impact pressure during position switching.

In order to achieve the above object, according to one aspect of the present utility model, there is provided a control valve structure comprising:

The main valve body is provided with a main flow path, a first branch flow path and a second branch flow path, and the first branch flow path and the second branch flow path are arranged at intervals;

The main valve rod is movably arranged in the main flow passage in a penetrating way and is provided with a blocking position for blocking the communication part of the main flow passage and the first branch flow passage, an avoiding position for avoiding the communication part of the main flow passage and the first branch flow passage and a buffer position between the blocking position and the avoiding position;

The inlet valve is arranged on the first branch flow path, the bypass valve and the buffer valve are arranged on the second branch flow path at intervals, and the main flow path is communicated with the second branch flow path between the bypass valve and the buffer valve;

The main valve body is also provided with a first communication flow path, a first backflow flow path and a second backflow flow path, wherein the first communication flow path is used for being communicated with the first branch flow path, and the first backflow flow path and the second backflow flow path are both used for being communicated with the first branch flow path; when the main valve rod is in the blocking position, the inlet valve is closed, the bypass valve is opened, and the buffer valve is closed, so that fluid in the main flow path flows back through the first backflow flow path; when the main valve rod is at the avoidance position, the inlet valve is opened, the bypass valve and the buffer valve are closed, so that fluid in the main flow path flows out through the first communication flow path; when the main valve stem is in the buffer position, the inlet valve and the bypass valve are closed and the buffer valve is opened to allow fluid in the main flow path to flow out through the second return flow path.

Further, the second branch flow path is provided with a first blocking opening, and a valve rod of the bypass valve is movably arranged on the second branch flow path so as to block or avoid the first blocking opening through the valve rod of the bypass valve; when the bypass valve avoids the first blocking opening, fluid in the second branch flow path flows into the first backflow flow path through the first blocking opening; and/or the number of the groups of groups,

The valve rod of the buffer valve is movably arranged on the second branch flow path so as to block or avoid the second blocking opening through the valve rod of the buffer valve; when the buffer valve avoids the second blocking opening, fluid in the second branch flow path flows into the second backflow flow path through the second blocking opening.

Further, a liquid storage tank is arranged on the main valve rod, a second communication flow path is further arranged on the main valve body, one end of the second communication flow path is communicated with the buffer cavity of the bypass valve, and the other end of the second communication flow path is communicated with the liquid storage tank;

When the bypass valve moves to plug the first plugging port, fluid in the liquid storage tank flows into a buffer cavity of the bypass valve through the second communication flow path; when the bypass valve moves to avoid the first blocking opening, fluid in the buffer cavity of the bypass valve flows into the liquid storage tank through the second communication flow path.

Further, the reservoir includes:

A radial groove extending in the radial direction of the main valve rod, the radial groove communicating with the other end of the second communication flow path;

and the axial groove is communicated with the radial groove and extends along the axial direction of the main valve rod.

Further, a third communication flow path is further arranged on the main valve body, one end of the third communication flow path is communicated with the main flow path, and the other end of the third communication flow path is communicated with a spring cavity of the buffer valve;

When the main valve rod is at the blocking position, the main valve rod blocks the communication part of the third communication flow path and the main flow path; when the main valve rod is at the avoidance position, the main valve rod avoids the communication position of the third communication flow path and the main flow path.

Further, a third branch flow path and a third backflow branch which are mutually communicated are also arranged on the main valve body, and the third branch flow path is communicated with the first communication flow path; the control valve structure further includes:

The valve rod of the oil return valve is at least partially movably arranged in the third branch flow path so as to perform blocking and blocking or avoiding communication on the third branch flow path through the valve rod of the oil return valve;

When the valve rod of the oil return valve carries out avoidance communication on the third branch flow path, fluid in the first communication flow path flows out of the third return branch through the third branch flow path; when the valve rod of the oil return valve is used for blocking and isolating the third branch flow path, the first communication flow path is disconnected from the third return branch.

Further, the end part of the valve rod of the oil return valve extends out of the third branch flow path; the control valve structure further includes:

And the operating piece is arranged on the main valve rod, and protrudes out of the main valve rod, and at least part of the operating piece is arranged opposite to the valve rod of the oil return valve so that the main valve rod pushes the valve rod of the oil return valve to move through the operating piece.

Further, at least part of the buffer valve extends out of the second branch flow path to be arranged, an avoidance hole is further formed in the operation piece, the avoidance hole is matched with at least part of the buffer valve, and at least part of the buffer valve penetrates through the avoidance hole.

According to another aspect of the present utility model, there is provided a hydraulic control system including:

The control valve structure provided above;

The oil cylinder is communicated with the first communication flow path;

the oil tank, the first return flow path and the second return flow path are communicated with the oil tank.

According to a further aspect of the present utility model there is provided a tractor comprising the hydraulic control system provided above.

By adopting the technical scheme, the buffer position is arranged between the plugging position and the avoiding position of the main valve rod, so that the main valve rod passes through the buffer position when the main valve rod is switched from the plugging position to the avoiding position or from the avoiding position to the plugging position, and when the inlet valve and the bypass valve are closed, the buffer valve is opened so as to be convenient for smoothly flowing out the fluid in the main flow path through the second backflow flow path, thereby avoiding the condition of overhigh pressure in the main flow path, effectively playing the role of buffer, reducing the damage to the control valve structure and being convenient for protecting the control valve structure.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

Fig. 1 shows a schematic configuration of a hydraulic control system provided according to an embodiment of the present utility model;

FIG. 2 shows a schematic diagram of a hydraulic control system in a neutral state, provided in accordance with an embodiment of the present utility model;

Fig. 3 shows a schematic view of a hydraulic control system according to an embodiment of the present utility model in a raised state;

Fig. 4 is a schematic view showing a structure of a hydraulic control system according to an embodiment of the present utility model in a buffer state;

Fig. 5 shows a schematic view of the structure of the hydraulic control system provided according to the embodiment of the present utility model in a lowered state.

Wherein the above figures include the following reference numerals:

10. A control valve structure; 11. a main valve body; 111. a main flow path; 112. a first branch flow path; 113. a second branch flow path; 114. a first communication channel; 115. a first return flow path; 116. a second return flow path; 117. a third communication flow path; 118. a third branch flow path; 119. a third return leg; 12. a main valve rod; 121. a liquid storage tank; 1211. a radial groove; 1212. an axial groove; 13. an inlet valve; 14. a bypass valve; 15. a buffer valve; 16. an oil return valve; 17. an operating member;

20. An oil cylinder; 30. an oil tank; 40. an oil absorption filter; 50. an oil pump; 60. a safety valve.

Detailed Description

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. The utility model will be described in detail below with reference to the drawings in connection with embodiments.

As shown in fig. 1 to 5, a first embodiment of the present utility model provides a control valve structure 10, the control valve structure 10 including a main valve body 11, a main valve stem 12, an inlet valve 13, a bypass valve 14, and a buffer valve 15, the main valve body 11 being provided with a main flow path 111, a first branch flow path 112, and a second branch flow path 113, the first branch flow path 112 and the second branch flow path 113 being disposed at intervals. The main valve stem 12 is movably inserted into the main passage 111, and the main valve stem 12 has a blocking position for blocking a communication portion between the main passage 111 and the first branch passage 112, a avoiding position for avoiding a communication portion between the main passage 111 and the first branch passage 112, and a buffer position between the blocking position and the avoiding position. The inlet valve 13 is provided in the first branch flow path 112, the bypass valve 14 and the buffer valve 15 are provided in the second branch flow path 113 at a distance, and the main flow path 111 communicates with the second branch flow path 113 located between the bypass valve 14 and the buffer valve 15. The main valve body 11 further has a first communication flow path 114, a first return flow path 115, and a second return flow path 116, the first communication flow path 114 being for communication with the first branch flow path 112, the first return flow path 115 and the second return flow path 116 being for communication with the first branch flow path 112; when the main valve stem 12 is in the blocking position, the inlet valve 13 is closed, the bypass valve 14 is opened, and the buffer valve 15 is closed, so that the fluid in the main flow path 111 flows back through the first return flow path 115; when the main valve stem 12 is in the escape position, the inlet valve 13 is opened, and the bypass valve 14 and the cushion valve 15 are both closed, so that the fluid in the main flow passage 111 flows out through the first communication flow passage 114; when the main valve stem 12 is in the buffer position, the inlet valve 13 and the bypass valve 14 are closed, and the buffer valve 15 is opened, so that the fluid in the main flow path 111 flows out through the second return flow path 116.

By adopting the control valve structure 10 provided by the embodiment, the buffer position is arranged between the plugging position and the avoiding position of the main valve rod 12, so that when the main valve rod 12 is switched from the plugging position to the avoiding position or from the avoiding position to the plugging position, the main valve rod 12 can pass through the buffer position, and thus, when the inlet valve 13 and the bypass valve 14 are closed, the buffer valve 15 is opened, so that fluid in the main flow path 111 can smoothly flow out through the second backflow flow path 116, the condition of overhigh pressure in the main flow path 111 is avoided, the buffer effect is effectively achieved, the damage to the control valve structure 10 is reduced, and the control valve structure 10 is protected conveniently.

In particular, the inlet valve 13 may be of one-way valve construction. Specifically, in this embodiment, the main valve body 11 is provided with an oil inlet, the oil inlet is located above the first branch flow path 112, the main flow path 111 is located below the first branch flow path 112, the communication mode between the oil inlet and the main flow path is shown by a dotted line passing through the first branch flow path 112 in fig. 1, which can also be understood that the oil inlet and the main flow path are directly connected through a connection channel on the main valve body 11, one end of the connection channel is communicated with the oil inlet, the other end of the connection channel is communicated with the main flow path, and the connection channel avoids the first branch flow path 112, that is, the connection channel and the first branch flow path 112 are not communicated.

In the present embodiment, the second branch flow path 113 has a first plugging port thereon, and the valve rod of the bypass valve 14 is movably disposed on the second branch flow path 113, so as to plug or avoid the first plugging port through the valve rod of the bypass valve 14; when the bypass valve 14 bypasses the first seal, the fluid in the second branch flow path 113 flows into the first return flow path 115 through the first seal. By adopting the structure, the bypass valve 14 is simple in structure, convenient to operate and capable of plugging or avoiding the first plugging port smoothly, so that the bypass valve 14 is opened or closed.

Specifically, the second branch flow path 113 in this embodiment has a second plugging port, and the valve rod of the buffer valve 15 is movably disposed on the second branch flow path 113, so as to plug or avoid the second plugging port through the valve rod of the buffer valve 15; when the buffer valve 15 bypasses the second blocking port, the fluid in the second branch flow path 113 flows into the second return flow path 116 through the second blocking port. By adopting the structure, the buffer valve 15 is simple in structure, convenient to operate and capable of plugging or avoiding the first plugging port smoothly, so that the buffer valve 15 is opened or closed.

In this embodiment, the main valve stem 12 is provided with a liquid storage tank 121, and the main valve body 11 is further provided with a second communication flow path, one end of which is communicated with the buffer chamber of the bypass valve 14, and the other end of which is communicated with the liquid storage tank 121. When the bypass valve 14 moves to block the first blocking opening, the fluid in the liquid storage tank 121 flows into the buffer cavity of the bypass valve 14 through the second communication flow path; when the bypass valve 14 moves to avoid the first blocking port, the fluid in the buffer chamber of the bypass valve 14 flows into the reservoir 121 through the second communication flow path. With such a structural arrangement, it is convenient to change the flow direction of the fluid in the reservoir 121 and the buffer chamber according to circumstances, so as to open or close the bypass valve 14.

Specifically, the reservoir 121 includes a radial groove 1211 and an axial groove 1212, the radial groove 1211 extending in the radial direction of the main valve stem 12, the radial groove 1211 communicating with the other end of the second communication flow path. The axial slots 1212 communicate with radial slots 1211, the axial slots 1212 extending in the axial direction of the main valve stem 12. With such a structural arrangement, it is convenient to increase the volume of the reservoir 121, to better accommodate more fluid, and to switch the state of the bypass valve 14.

Specifically, the radial grooves 1211 may be plural, the plural radial grooves 1211 being disposed at intervals along the extending direction of the axial groove 1212, the plural radial grooves 1211 each communicating with the axial groove 1212.

In the present embodiment, the main valve body 11 is further provided with a third communication passage 117, one end of the third communication passage 117 communicates with the main passage 111, and the other end of the third communication passage 117 communicates with the spring chamber of the cushion valve 15. Wherein, when the main valve rod 12 is at the blocking position, the main valve rod 12 blocks the communication position of the third communication flow path 117 and the main flow path 111; when the main valve stem 12 is in the evacuation position, the main valve stem 12 evacuates the communication between the third communication passage 117 and the main passage 111. By adopting the structure, the device is simple in structure, convenient to operate and convenient to block or avoid the communication part of the third communication flow path 117 and the main flow path 111 through the main valve rod 12, so that buffer depressurization is convenient to be carried out smoothly.

Specifically, the main valve body 11 is further provided with a third branch flow passage 118 and a third return branch passage 119 which communicate with each other, and the third branch flow passage 118 communicates with the first communication flow passage 114. The control valve structure 10 further includes an oil return valve 16, at least a portion of the valve stem of the oil return valve 16 being movably disposed within the third branch flow path 118 to block or unblock the third branch flow path 118 through the valve stem of the oil return valve 16. When the valve rod of the oil return valve 16 performs the avoidance communication with the third branch flow path 118, the fluid in the first communication flow path 114 flows out from the third return branch 119 through the third branch flow path 118; when the valve rod of the oil return valve 16 closes and blocks the third branch passage 118, the first communication passage 114 is disconnected from the third return passage 119. With such a structural arrangement, stable oil return is facilitated by the oil return valve 16.

Specifically, the return valve 16 may be a one-way valve structure. Specifically, as shown by a broken line between the third branch flow path 118 and the first communication flow path 114 in fig. 1, the third branch flow path 118 and the first communication flow path 114 are directly communicated through a communication channel on the main valve body 11, one end of the communication channel is communicated with the third branch flow path 118, the other end of the communication channel is communicated with the first communication flow path 114, and the communication channel is arranged avoiding the main flow path 111 and the second branch flow path 113, that is, the communication channel is not arranged in communication with the main flow path 111 and the second branch flow path 113.

In the present embodiment, the end of the valve stem of the oil return valve 16 extends out of the third branch flow passage 118. The control valve structure 10 further includes an operating member 17, the operating member 17 being disposed on the main valve stem 12, the operating member 17 protruding from the main valve stem 12, at least a portion of the operating member 17 being disposed opposite the valve stem of the scavenge valve 16 such that the main valve stem 12 pushes the valve stem of the scavenge valve 16 through the operating member 17. Specifically, the operating member 17 is fixedly coupled to the main valve stem 12 so as to facilitate a valve stem movement that urges the spill valve 16 to open during operation of the main valve stem 12.

Specifically, the operating member 17 includes an operating plate and an operating lever that are connected to each other, the operating plate is fixedly connected to the main valve stem 12, the operating lever is fixedly connected to the operating plate, and the operating lever is disposed opposite to the valve stem of the oil return valve 16, so as to drive the operating lever to move during the movement of the main valve stem 12, and to push the oil return valve 16 to move, so that the oil return valve 16 is opened.

Specifically, at least part of the cushion valve 15 extends out of the second branch flow path 113, and the operating member 17 is further provided with a relief hole, which is adapted to at least part of the cushion valve 15, and at least part of the cushion valve 15 is disposed in the relief hole in a penetrating manner. With such a configuration, the force of the operating element 17 can be prevented from acting on the cushion valve 15, and damage to the cushion valve 15 due to a large force acting on the cushion valve 15 can be prevented.

A second embodiment of the present utility model provides a hydraulic control system including: the control valve structure 10, the oil cylinder 20 and the oil tank 30 provided in the first embodiment, the oil cylinder 20 is communicated with the first communication flow path 114; the first return flow path 115 and the second return flow path 116 are both in communication with the tank 30. With such a structural arrangement, it is convenient to return the fluid of both the first return flow path 115 and the second return flow path 116 into the tank 30. In addition, the main valve body 11 is further provided with an oil inlet which is communicated with the main flow path 111, and the oil inlet is communicated with the oil tank 30, so that the oil in the oil tank 30 can smoothly enter the main flow path 111 through the oil inlet.

The hydraulic control system in this embodiment further includes an oil suction filter 40, an oil pump 50 and a safety valve 60, so as to filter impurities in the oil through the oil suction filter 40, the oil pump 50 can provide sufficient power for the oil circulation, and the safety valve 60 can ensure that the oil of the whole hydraulic control system is controlled in a safe hydraulic range.

Specifically, the hydraulic control system in the present embodiment has a neutral state, an ascending state, a buffering state, and a descending state.

Wherein, as shown in fig. 2, when the hydraulic control system is in the neutral state: the oil pump 50 conveys the oil in the oil tank 30 to the P port (i.e., the oil inlet) of the multiway valve through the oil suction filter 40, at this time, the main valve rod 12 is in the middle position, the bypass valve 14 is opened by the pressure oil, and the oil flows back to the oil tank 30 through the T1 port of the first return flow path 115.

As shown in fig. 3, when the hydraulic control system is in the raised state: when the main valve stem 12 moves to the right, the pressure oil passes through the main valve stem 12 to the spring chamber of the bypass valve 14, at which time the bypass valve 14 is in a closed state under the spring force. The pressurized oil reaches the spring chamber of the cushion valve 15 at the same time and is also in a closed state under the action of the spring force. The pressure oil also reaches the inlet valve 13 after passing through the main valve rod 12, and after opening the inlet valve 13, the pressure oil enters the oil cylinder 20 to realize the rising of the oil cylinder 20. Specifically, the arrow on the right side of the operation member 17 in fig. 3 represents the movement direction of the operation member 17.

As shown in fig. 4, when the hydraulic control system is in the buffer state: when the main valve stem 12 moves to the left to reach the neutral position, the bypass valve 14 is in a closed state, and the return valve 16 is not opened. Because the main valve stem 12 is in a nearly neutral state, the oil pressure is gradually reduced by the throttle grooves (including the radial grooves 1211 and the axial grooves 1212) of the main valve stem 12, and then the pressure after passing through the throttle holes is gradually reduced, and at this time, the pressure acting on the cushion valve 15 is gradually increased, and the oil pressure opens the cushion valve 15 and returns to the oil tank 30. In this way, the working pressure is gradually reduced during the return of the main valve stem 12 to the neutral position, thereby avoiding a large shock. Specifically, the orifice is located between the main flow path 111 and the spring chamber of the trim valve 15 so that the reservoir 121 on the main valve stem 12 communicates with or is disconnected from the spring chamber of the trim valve 15 through the orifice. Specifically, the arrow on the right side of the operation member 17 in fig. 4 represents the movement direction of the operation member 17.

As shown in fig. 5, when the hydraulic control system is in the lowered state: when the main valve stem 12 moves to the left, the pressure oil passes through the main valve stem 12 to the bypass valve 14; at this time, the spring chamber of the bypass valve 14 returns oil through the main valve stem 12, and the pressure oil can open the bypass valve 14 and then return oil to the oil tank 30 through the port T1. When the main valve rod 12 moves leftwards, the main valve rod 12 drives the operation piece 17 to move simultaneously, pushing the oil return valve 16 to move leftwards against the spring force, and thus opening the oil return valve 16. Under the load action of the oil cylinder 20, oil in a large cavity of the oil cylinder 20 is directly returned to the oil tank 30 through the oil return valve 16, so that descending is realized. Specifically, the operating member 17 may be a pull rod, and the oil return valve 16 may also be referred to as a descent valve. Specifically, the two arrows on the right side of the operation member 17 in fig. 5 represent the movement direction of the operation member 17 and the movement direction of the valve stem of the oil return valve 16, respectively.

An embodiment III of the present utility model provides a tractor, including the hydraulic control system provided in the above embodiment II. In particular, the hydraulic control system is suitable for use with a rear suspension of a low horsepower tractor.

From the above description, it can be seen that the above embodiments of the present utility model achieve the following technical effects: the structure is compact, the reliability is high, buffering can be effectively carried out, and the impact force received by the control valve structure 10 is reduced.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

The relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective parts shown in the drawings are not drawn in actual scale for convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.

In the description of the present application, it should be understood that the azimuth or positional relationships indicated by the azimuth terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal", and "top, bottom", etc., are generally based on the azimuth or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and these azimuth terms do not indicate and imply that the apparatus or elements referred to must have a specific azimuth or be constructed and operated in a specific azimuth, and thus should not be construed as limiting the scope of protection of the present application; the orientation word "inner and outer" refers to inner and outer relative to the contour of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "upper surface on … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial location relative to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above … …" may include both orientations "above … …" and "below … …". The device may also be positioned in other different ways (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, the terms "first", "second", etc. are used to define the components, and are only for convenience of distinguishing the corresponding components, and the terms have no special meaning unless otherwise stated, and therefore should not be construed as limiting the scope of the present application.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (10)

1. A control valve structure, comprising:

A main valve body (11), wherein a main flow path (111), a first branch flow path (112) and a second branch flow path (113) are arranged on the main valve body (11), and the first branch flow path (112) and the second branch flow path (113) are arranged at intervals;

A main valve rod (12) movably penetrating the main flow path (111), wherein the main valve rod (12) is provided with a blocking position for blocking a communication part between the main flow path (111) and the first branch flow path (112), a avoiding position for avoiding a communication part between the main flow path (111) and the first branch flow path (112), and a buffer position between the blocking position and the avoiding position;

An inlet valve (13), a bypass valve (14) and a buffer valve (15), the inlet valve (13) being provided on the first branch flow path (112), the bypass valve (14) and the buffer valve (15) being provided on the second branch flow path (113) at an interval, the main flow path (111) being in communication with the second branch flow path (113) between the bypass valve (14) and the buffer valve (15);

Wherein the main valve body (11) further has a first communication flow path (114), a first return flow path (115), and a second return flow path (116), the first communication flow path (114) being for communication with the first branch flow path (112), the first return flow path (115) and the second return flow path (116) being for communication with the first branch flow path (112); when the main valve rod (12) is in the blocking position, the inlet valve (13) is closed, the bypass valve (14) is opened, and the buffer valve (15) is closed, so that fluid in the main flow path (111) flows back through the first backflow flow path (115); when the main valve rod (12) is at the avoidance position, the inlet valve (13) is opened, the bypass valve (14) and the buffer valve (15) are closed, so that the fluid in the main flow path (111) flows out through the first communication flow path (114); when the main valve rod (12) is in the buffer position, the inlet valve (13) and the bypass valve (14) are closed, and the buffer valve (15) is opened, so that the fluid in the main flow path (111) flows out through the second backflow flow path (116).

2. The control valve structure according to claim 1, characterized in that the second branch flow path (113) has a first blocking port thereon, and a valve stem of the bypass valve (14) is movably disposed on the second branch flow path (113) to block or avoid the first blocking port by a valve stem of the bypass valve (14); when the bypass valve (14) bypasses the first blocking port, the fluid in the second branch flow path (113) flows into the first return flow path (115) through the first blocking port; and/or the number of the groups of groups,

The second branch flow path (113) is provided with a second plugging port, and a valve rod of the buffer valve (15) is movably arranged on the second branch flow path (113) so as to plug or avoid the second plugging port through the valve rod of the buffer valve (15); when the buffer valve (15) avoids the second blocking port, the fluid in the second branch flow path (113) flows into the second return flow path (116) through the second blocking port.

3. The control valve structure according to claim 2, characterized in that a liquid storage tank (121) is provided on the main valve stem (12), a second communication flow path is further provided on the main valve body (11), one end of the second communication flow path is communicated with the buffer chamber of the bypass valve (14), and the other end of the second communication flow path is communicated with the liquid storage tank (121);

When the bypass valve (14) moves to seal the first sealing opening, fluid in the liquid storage tank (121) flows into a buffer cavity of the bypass valve (14) through the second communication flow path; when the bypass valve (14) moves to avoid the first blocking opening, fluid in the buffer cavity of the bypass valve (14) flows into the liquid storage tank (121) through the second communication flow path.

4. A control valve structure according to claim 3, characterized in that the reservoir (121) comprises:

A radial groove (1211), the radial groove (1211) extending in a radial direction of the main valve stem (12), the radial groove (1211) communicating with the other end of the second communication flow path;

an axial slot (1212) in communication with the radial slot (1211), the axial slot (1212) extending axially of the main valve stem (12).

5. The control valve structure according to claim 2, characterized in that a third communication flow path (117) is further provided on the main valve body (11), one end of the third communication flow path (117) communicates with the main flow path (111), and the other end of the third communication flow path (117) communicates with a spring chamber of the cushion valve (15);

Wherein when the main valve rod (12) is at the blocking position, the main valve rod (12) blocks a communication position between the third communication flow path (117) and the main flow path (111); when the main valve rod (12) is at the avoidance position, the main valve rod (12) performs avoidance on a communication position between the third communication flow path (117) and the main flow path (111).

6. The control valve structure according to claim 1, characterized in that a third branch flow path (118) and a third return flow path (119) which are communicated with each other are further provided on the main valve body (11), the third branch flow path (118) being communicated with the first communication flow path (114); the control valve structure further includes:

-an oil return valve (16), at least part of the valve stem of the oil return valve (16) being movably arranged in the third branch flow path (118) for blocking or avoiding communication of the third branch flow path (118) by the valve stem of the oil return valve (16);

When the valve rod of the oil return valve (16) is communicated with the third branch flow path (118) in a avoidance mode, fluid in the first communication flow path (114) flows out of the third return branch path (119) through the third branch flow path (118); when the valve rod of the oil return valve (16) seals and closes the third branch flow path (118), the first communication flow path (114) is disconnected from the third return flow path (119).

7. The control valve structure according to claim 6, characterized in that an end portion of a valve stem of the oil return valve (16) is provided to protrude from the third branch flow passage (118); the control valve structure further includes:

The operating piece (17) is arranged on the main valve rod (12), the operating piece (17) protrudes out of the main valve rod (12), and at least part of the operating piece (17) is arranged opposite to the valve rod of the oil return valve (16) so that the main valve rod (12) pushes the valve rod of the oil return valve (16) to move through the operating piece (17).

8. The control valve structure according to claim 7, characterized in that at least part of the buffer valve (15) extends out of the second branch flow path (113), the operating member (17) is further provided with a relief hole, the relief hole is adapted to at least part of the buffer valve (15), and at least part of the buffer valve (15) is inserted into the relief hole.

9. A hydraulic control system, comprising:

The control valve structure of any one of claims 1 to 8;

an oil cylinder (20) which communicates with the first communication passage (114);

-an oil tank (30), said first return flow path (115) and said second return flow path (116) being both in communication with said oil tank (30).

10. A tractor comprising the hydraulic control system of claim 9.