CN117553045A - Control valve structure, hydraulic control system and tractor - Google Patents

Abstract

The invention 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 invention, 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 present invention relates to the technical field of hydraulic control systems, and specifically to a control valve structure, a hydraulic control system and a tractor.

Background technique

Currently, the existing technology can control the rise and fall of the oil cylinder through the control valve structure. Specifically, the control valve structure is used to supply oil into the oil cylinder to realize the rise of the oil cylinder, and the control valve structure is used to cause the oil in the oil cylinder to flow out to realize the descent of the oil cylinder. In the prior art, the state of the oil cylinder is generally changed by changing the structural position of the control valve.

However, control valves in the prior art often receive a large impact force during the position switching process. The large impact force will directly act on the control valve itself, which will cause greater damage to the control valve structure in the long term. damage.

Contents of the invention

The main purpose of the present invention is to provide a control valve structure, a hydraulic control system and a tractor to solve the technical problem in the prior art that the control valve structure receives large impact pressure when switching positions.

In order to achieve the above objects, according to one aspect of the present invention, a control valve structure is provided, including:

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 stem is movably installed in the main flow path. The main valve stem has a blocking position for blocking the connection between the main flow path and the first branch flow path, and a blocking position for blocking the connection between the main flow path and the first branch flow path. The avoidance position for avoidance and the buffer position between the blocking position and the avoidance position;

Inlet valve, bypass valve and buffer valve, 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, the main flow path is connected to the second branch flow path between the bypass valve and the buffer valve. Branch flow paths are connected;

Wherein, the main valve body also has a first communication flow path, a first return flow path and a second return flow path. The first communication flow path is used to communicate with the first branch flow path, the first return flow path and the second return flow path. are used to communicate with the first branch flow path; when the main valve stem is in the blocking position, the inlet valve is closed, the bypass valve is opened, and the buffer valve is closed, so that the fluid in the main flow path returns through the first return flow path; when the main valve stem is in the blocking position When the valve stem is in the avoidance position, the inlet valve is open and the bypass valve and buffer valve are closed to allow the fluid in the main flow path to flow out through the first communication flow path; when the main valve stem is in the buffer position, the inlet valve and bypass valve are closed , the buffer valve opens, so that the fluid in the main flow path flows out through the second return flow path.

Further, there is a first blocking port on the second branch flow path, and the valve stem of the bypass valve is movably disposed on the second branch flow path to block the first blocking port through the valve stem of the bypass valve or Avoid; when the bypass valve avoids the first blocking port, the fluid in the second branch flow path flows into the first return flow path through the first blocking port; and/or,

There is a second blocking port on the second branch flow path, and the valve stem of the buffer valve is movably disposed on the second branch flow path to block or avoid the second blocking port through the valve stem of the buffer valve; when the buffer valve When the second blocking port is avoided, the fluid in the second branch flow path flows into the second return flow path through the second blocking port.

Further, the main valve stem is provided with a liquid storage tank, and the main valve body is also provided with a second communication flow path. One end of the second communication flow path is connected to the buffer chamber of the bypass valve, and the other end of the second communication flow path is connected to the buffer chamber of the bypass valve. Connected to the liquid reservoir;

Wherein, when the bypass valve moves to block the first blocking port, the fluid in the liquid storage tank flows into the buffer cavity of the bypass valve through the second communication channel; when the bypass valve moves to block the first blocking port When the blocking port is being avoided, the fluid in the buffer cavity of the bypass valve flows into the liquid storage tank through the second communication channel.

Further, the liquid storage tank includes:

a radial groove extending along the radial direction of the main valve stem, and the radial groove is connected with the other end of the second communication flow path;

The axial groove is connected with the radial groove, and the axial groove extends along the axial direction of the main valve stem.

Further, the main valve body is also provided with a third communication flow path, one end of the third communication flow path is connected to the main flow path, and the other end of the third communication flow path is connected to the spring chamber of the buffer valve;

Among them, when the main valve stem is in the blocking position, the main valve stem blocks the connection between the third connecting flow path and the main flow path; when the main valve stem is in the avoidance position, the main valve stem blocks the connection between the third connecting flow path and the main flow path. Avoid the connecting points.

Further, the main valve body is also provided with a third branch flow path and a third return branch path that communicate with each other, and the third branch flow path is connected with the first communication flow path; the control valve structure also includes:

An oil return valve, at least part of the valve stem of the oil return valve is movably disposed in the third branch flow path, so as to block, block or avoid communication with the third branch flow path through the valve stem of the oil return valve;

Among them, when the valve stem of the oil return valve communicates with the third branch flow path, the fluid in the first communication flow path flows out through the third branch flow path through the third return branch; when the valve stem of the oil return valve connects with the third branch flow path, When the three-branch flow path is blocked and blocked, the first connecting flow path is disconnected from the third return branch path.

Further, the end of the valve stem of the oil return valve extends out of the third branch flow path; the control valve structure also includes:

The operating piece is arranged on the main valve stem, and the operating piece protrudes from the main valve stem. At least part of the operating piece is set opposite to the valve stem of the oil return valve, so that the main valve stem pushes the valve stem of the oil return valve through the operating piece. sports.

Further, at least part of the buffer valve extends out of the second branch flow path, and the operating member is also provided with an escape hole. The escape hole is adapted to at least part of the buffer valve, and at least part of the buffer valve is disposed in the escape hole. .

According to another aspect of the invention, a hydraulic control system is provided, including:

The control valve structure provided above;

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

The fuel tank, the first return flow path and the second return flow path are both connected to the fuel tank.

According to yet another aspect of the present invention, a tractor is provided, including the hydraulic control system provided above.

By applying the technical solution of the present invention, a buffer position is provided between the blocking position and the avoidance position of the main valve stem, so that when the main valve stem switches from the blocking position to the avoidance position or from the avoidance position to the blocking position, The main valve stem will pass through the buffer position. In this way, when the inlet valve and the bypass valve are closed, the buffer valve opens to facilitate the smooth flow of the fluid in the main flow path through the second return flow path, thereby avoiding excessive pressure in the main flow path. When the pressure is high, it effectively plays a buffering role, reduces damage to the control valve structure, and facilitates protection of the control valve structure.

Description of the drawings

The description and drawings that constitute a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 shows a schematic structural diagram of a hydraulic control system provided according to an embodiment of the present invention;

Figure 2 shows a schematic structural diagram of the hydraulic control system in a neutral state according to an embodiment of the present invention;

Figure 3 shows a schematic structural diagram of the hydraulic control system in an ascending state according to an embodiment of the present invention;

Figure 4 shows a schematic structural diagram of the hydraulic control system in a buffering state according to an embodiment of the present invention;

FIG. 5 shows a schematic structural diagram of the hydraulic control system in a descending state according to an embodiment of the present invention.

Among them, the above-mentioned drawings include the following reference signs:

10. Control valve structure; 11. Main valve body; 111. Main flow path; 112. First branch flow path; 113. Second branch flow path; 114. First connecting flow path; 115. First return flow path; 116 , the second return flow path; 117. the third connecting flow path; 118. the third branch flow path; 119. the third return branch path; 12. main valve stem; 121. liquid storage tank; 1211. radial groove; 1212 , Axial groove; 13. Inlet valve; 14. Bypass valve; 15. Buffer valve; 16. Oil return valve; 17. Operating parts;

20. Oil cylinder; 30. Oil tank; 40. Oil suction filter; 50. Oil pump; 60. Safety valve.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

As shown in Figures 1 to 5, Embodiment 1 of the present invention provides a control valve structure 10. The control valve structure 10 includes a main valve body 11, a main valve stem 12, an inlet valve 13, a bypass valve 14 and a buffer. The main valve body 11 of the valve 15 is provided with a main channel 111, a first branch channel 112 and a second branch channel 113. The first branch channel 112 and the second branch channel 113 are spaced apart. The main valve stem 12 is movably disposed in the main channel 111. The main valve stem 12 has a blocking position for blocking the connection between the main channel 111 and the first branch channel 112, and a blocking position for blocking the main channel 111 and the first branch channel 112. The avoidance position where the connection point of the branch channel 112 is avoided and the buffer position located between the blocking position and the avoidance position. The inlet valve 13 is disposed on the first branch flow path 112 , the bypass valve 14 and the buffer valve 15 are disposed on the second branch flow path 113 , and the main flow path 111 is connected to the second branch flow path 112 between the bypass valve 14 and the buffer valve 15 . The branch flow paths 113 are connected. Among them, the main valve body 11 also 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 is used to communicate with the first branch flow path 112, and the first return flow path 114 is used to communicate with the first branch flow path 112. Both the channel 115 and the second return channel 116 are used to communicate with the first branch channel 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 to allow the main flow to flow. The fluid in the flow path 111 flows back through the first return flow path 115; when the main valve stem 12 is in the avoidance position, the inlet valve 13 is opened, and the bypass valve 14 and the buffer valve 15 are closed, so that the fluid in the main flow path 111 passes through the first return flow path 115. The connecting flow path 114 flows out; when the main valve stem 12 is in the buffering 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 .

Using the control valve structure 10 provided in this embodiment, a buffer position is provided between the blocking position and the avoidance position of the main valve stem 12, so that the main valve stem 12 switches from the blocking position to the avoidance position or from the avoidance position. When reaching the blocking position, the main valve stem 12 will pass through the buffer position. In this way, when the inlet valve 13 and the bypass valve 14 are closed, the buffer valve 15 is opened to facilitate the smooth flow of the fluid in the main channel 111 through the second return flow. The flow path 116 flows out, thereby avoiding excessive pressure in the main path 111 , effectively acting as a buffer, reducing damage to the control valve structure 10 , and facilitating protection of the control valve structure 10 .

Specifically, the inlet valve 13 may be a one-way valve structure. 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, and the main flow path 111 is located below the first branch flow path 112. The oil inlet and the main flow path are The connection mode is shown as the dotted line passing through the first branch flow path 112 in Figure 1. It can also be understood that the oil inlet and the main flow path are directly connected through the connecting channel on the main valve body 11, and one end of the connecting channel is connected to the oil inlet. The other end of the connecting channel is connected with the main flow channel. The connecting channel is arranged to avoid the first branch flow channel 112 , that is, the connecting channel is not connected to the first branch flow channel 112 .

In this embodiment, the second branch flow path 113 has a first blocking port, and the valve stem of the bypass valve 14 is movably disposed on the second branch flow path 113 to allow the valve stem of the bypass valve 14 to pass through. The first blocking port blocks or avoids it; when the bypass valve 14 avoids 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. . With such a structural arrangement, the structure is simple, easy to operate, and easy to block or avoid the first blocking port to open or close the bypass valve 14.

Specifically, the second branch flow path 113 in this embodiment has a second blocking port, and the valve stem of the buffer valve 15 is movably disposed on the second branch flow path 113 to allow the valve stem of the buffer valve 15 to pass through. The second blocking port blocks or avoids it; 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. Adopting such a structural arrangement, the structure is simple, easy to operate, and easy to block or avoid the first blocking port to open or close the buffer valve 15.

In this embodiment, the main valve stem 12 is provided with a liquid storage tank 121, and the main valve body 11 is also provided with a second communication flow path. One end of the second communication flow path is connected to the buffer chamber of the bypass valve 14. The other end of the two communication channels is connected to the liquid storage tank 121 . When the bypass valve 14 moves to block the first blocking port, the fluid in the liquid storage tank 121 flows into the buffer cavity of the bypass valve 14 through the second communication channel; when the bypass valve 14 moves When the first blocking port is avoided, the fluid in the buffer chamber of the bypass valve 14 flows into the liquid storage tank 121 through the second communication channel. With such a structural arrangement, it is convenient to change the flow direction of the fluid in the liquid storage tank 121 and the buffer chamber according to specific conditions, so as to open or close the bypass valve 14.

Specifically, the liquid reservoir 121 includes a radial groove 1211 and an axial groove 1212. The radial groove 1211 extends along the radial direction of the main valve stem 12, and the radial groove 1211 is connected to the other end of the second communication flow path. The axial groove 1212 is connected with the radial groove 1211 , and the axial groove 1212 extends along the axial direction of the main valve stem 12 . Adopting such a structural arrangement makes it easier to increase the volume of the liquid storage tank 121 and better accommodate more fluids, thereby making it easier to switch the state of the bypass valve 14 .

Specifically, there may be a plurality of radial grooves 1211 , the plurality of radial grooves 1211 are spaced apart along the extension direction of the axial groove 1212 , and the plurality of radial grooves 1211 are all connected with the axial groove 1212 .

In this embodiment, the main valve body 11 is also provided with a third communication channel 117. One end of the third communication channel 117 is connected to the main channel 111, and the other end of the third communication channel 117 is connected to the spring of the buffer valve 15. The cavity is connected. Among them, when the main valve stem 12 is in the blocking position, the main valve stem 12 blocks the connection between the third communication channel 117 and the main flow channel 111; when the main valve stem 12 is in the avoidance position, the main valve stem 12 blocks the connection between the third communication channel 117 and the main flow channel 111. The connection between the communication flow path 117 and the main flow path 111 is avoided. With such a structural arrangement, the structure is simple, easy to operate, and the connection between the third communication flow path 117 and the main flow path 111 can be blocked or avoided smoothly through the main valve stem 12, thereby facilitating smooth buffering and pressure reduction.

Specifically, the main valve body 11 is also provided with a third branch flow path 118 and a third return branch path 119 that communicate with each other. The third branch flow path 118 is connected with the first communication flow path 114 . The control valve structure 10 further includes an oil return valve 16. At least part of the valve stem of the oil return valve 16 is movably disposed in the third branch flow path 118 to pass the valve stem of the oil return valve 16 to the third branch flow path 118. Block off or avoid connections. Among them, when the valve stem of the oil return valve 16 communicates with the third branch flow path 118, the fluid in the first communication flow path 114 flows out from the third return branch path 119 through the third branch flow path 118; when the oil return valve When the valve stem of the valve 16 blocks the third branch flow path 118 , the first communication flow path 114 and the third return branch path 119 are disconnected. Adopting such a structural arrangement facilitates smooth and stable oil return through the oil return valve 16.

Specifically, the oil return valve 16 may be a one-way valve structure. Specifically, the communication manner in which the third branch flow path 118 communicates with the first communication flow path 114 is shown by the dotted line between the third branch flow path 118 and the first communication flow path 114 in FIG. 1 . The third branch flow path 118 is directly connected to the first communication channel 114 through the communication channel on the main valve body 11. One end of the communication channel is connected to the third branch channel 118, and the other end of the communication channel is connected to the first communication channel 114. The communication channel It is arranged to avoid the main channel 111 and the second branch channel 113, that is, the communication channel is not connected to the main channel 111 and the second branch channel 113.

In this embodiment, the end of the valve stem of the oil return valve 16 extends out of the third branch flow path 118 . The control valve structure 10 also includes an operating member 17. The operating member 17 is disposed on the main valve stem 12. The operating member 17 protrudes from the main valve stem 12. At least part of the operating member 17 is disposed opposite the valve stem of the oil return valve 16. So that the main valve stem 12 pushes the valve stem of the oil return valve 16 to move through the operating member 17 . Specifically, the operating member 17 is fixedly connected to the main valve stem 12 so as to push the valve stem of the oil return valve 16 to move during the operation of the main valve stem 12 so as to open the oil return valve 16 .

Specifically, the operating member 17 includes an operating plate and an operating rod that are connected to each other. The operating plate is fixedly connected to the main valve stem 12 , the operating rod is fixedly connected to the operating plate, and the operating rod is arranged opposite to the valve stem of the oil return valve 16 to operate in the main valve. During the movement of the valve stem 12, the operating rod is driven to move, and the oil return valve 16 is pushed to move, so that the oil return valve 16 is opened.

Specifically, at least part of the buffer valve 15 extends out of the second branch flow path 113. The operating member 17 is also provided with an escape hole. The escape hole is adapted to at least part of the buffer valve 15. At least part of the buffer valve 15 passes through Located in the escape hole. Adopting such a structural arrangement can prevent the force of the operating member 17 from acting on the buffer valve 15 and avoid causing damage to the buffer valve 15 due to a large force on the buffer valve 15 .

The second embodiment of the present invention provides a hydraulic control system, including: the control valve structure 10 provided in the first embodiment, an oil cylinder 20 and a fuel tank 30. The oil cylinder 20 is connected to the first communication flow path 114; the first return flow path 115 and the second return flow path 116 are both connected to the fuel tank 30 . With such a structural arrangement, it is convenient for the fluids in the first return flow path 115 and the second return flow path 116 to flow back into the fuel tank 30 . In addition, the main valve body 11 is also provided with an oil inlet connected to the main channel 111, and the oil inlet is connected to the oil tank 30, so that the oil in the oil tank 30 can smoothly enter the main channel 111 through the oil inlet.

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

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

Among them, as shown in Figure 2, when the hydraulic control system is in the neutral state: the oil pump 50 transports the oil in the oil tank 30 to the P port (that is, the oil inlet) of the multi-way valve through the oil suction filter 40. At this time The main valve stem 12 is in the neutral position, the pressure oil opens the bypass valve 14, and the oil flows back to the oil tank 30 through the T1 port of the first return flow path 115.

As shown in Figure 3, when the hydraulic control system is in an ascending state: when the main valve stem 12 moves to the right, the pressure oil reaches the spring chamber of the bypass valve 14 through the main valve stem 12. At this time, the bypass valve 14 acts under the spring force. is closed. The pressure oil reaches the spring chamber of the buffer valve 15 at the same time, and is also in a closed state under the action of the spring force. After the pressure oil passes through the main valve stem 12, it also reaches the inlet valve 13. After the inlet valve 13 is opened, the pressure oil enters the oil cylinder 20 to realize the rise of the oil cylinder 20. Specifically, the arrow located on the right side of the operating member 17 in FIG. 3 represents the movement direction of the operating member 17 .

As shown in Figure 4, when the hydraulic control system is in a buffering state: when the main valve stem 12 moves to the left almost to the neutral position, the bypass valve 14 is in a closed state and the oil return valve 16 is not opened. Because the main valve stem 12 is near the neutral position, the pressure oil passing through the throttling groove of the main valve stem 12 (corresponding to the radial groove 1211 and the axial groove 1212) gradually decreases, and then the pressure after passing through the throttling hole It also gradually decreases. At this time, the pressure acting on the buffer valve 15 gradually increases, and the pressure oil opens the buffer valve 15 and then returns to the oil tank 30. In this way, during the 12 times the main valve stem returns to the neutral position, the working pressure gradually decreases, thus avoiding large impacts. Specifically, the orifice is located between the main flow path 111 and the spring chamber of the buffer valve 15 so that the liquid reservoir 121 on the main valve stem 12 is connected or disconnected from the spring chamber of the buffer valve 15 through the orifice. Specifically, the arrow located on the right side of the operating member 17 in FIG. 4 represents the movement direction of the operating member 17 .

As shown in Figure 5, when the hydraulic control system is in a descending state: when the main valve stem 12 moves to the left, the pressure oil reaches the bypass valve 14 through the main valve stem 12; at this time, the spring chamber of the bypass valve 14 passes through the main valve stem 12 To return oil, the pressure oil can open the bypass valve 14, and then return the oil to the oil tank 30 through the T1 port. When the main valve stem 12 moves to the left, the main valve stem 12 drives the operating member 17 to move at the same time, pushing the oil return valve 16 to move to the left against the spring force, thereby opening the oil return valve 16. When the oil cylinder 20 is under load, the oil in the large cavity of the oil cylinder 20 is directly returned to the oil tank 30 through the oil return valve 16, thereby achieving descent. Specifically, the operating member 17 can be a pull rod, and the oil return valve 16 can also be called a descending valve. Specifically, the two arrows located on the right side of the operating member 17 in FIG. 5 respectively represent the movement direction of the operating member 17 and the movement direction of the valve stem of the oil return valve 16 .

Embodiment 3 of the present invention provides a tractor, including the hydraulic control system provided in Embodiment 2 above. Specifically, the hydraulic control system is suitable for rear suspension devices of small-horsepower tractors.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: compact structure, high reliability, effective buffering, and reduction of impact force on the control valve structure 10 .

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that when the terms "comprises" and/or "includes" are used in this specification, they indicate There are features, steps, operations, means, components and/or combinations thereof.

The relative arrangement of components and steps, numerical expressions, and numerical values set forth in these examples do not limit the scope of the application unless specifically stated otherwise. At the same time, it should be understood that, for convenience of description, the dimensions of various parts shown in the drawings are not drawn according to actual proportional relationships. Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods and devices should be considered a part of the specification. In all examples shown and discussed herein, any specific values are to be construed as illustrative only and not as limiting. Accordingly, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters refer to similar items in the following figures, so that once an item is defined in one figure, it does not need further discussion in subsequent figures.

In the description of this application, it should be understood that the orientation indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom", etc. Or the positional relationship is usually based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description. Without explanation to the contrary, these directional words do not indicate and imply the referred devices or components. It must have a specific orientation or be constructed and operated in a specific orientation, so it cannot be understood as limiting the scope of the present application; the orientation words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

For the convenience of description, spatially relative terms can be used here, such as "on...", "on...", "on the upper surface of...", "above", etc., to describe what is shown in the figure. The spatial relationship between one device or feature and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a feature in the figure is turned over, then one feature described as "above" or "above" other features or features would then be oriented "below" or "below" the other features or features. under other devices or structures". Thus, the exemplary term "over" may include both orientations "above" and "below." The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In addition, it should be noted that the use of words such as "first" and "second" to define parts is only to facilitate the distinction between corresponding parts. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood. To limit the scope of protection of this application.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

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.