Speed-adjustable tractor multi-way valve

Abstract

The utility model discloses a speed-adjustable multi-way valve of a tractor. The problems that an existing tractor tool is too high in descending speed, and potential safety hazards exist are solved. The hydraulic control valve comprises a valve body, the valve body is provided with an oil inlet, a lifting oil port, a lifting oil way, a descending oil port, a feedback oil way and an oil return way, the hydraulic control valve further comprises a one-way valve, and the one-way valve is provided with a control cavity; the reversing valve rod is provided with a first position enabling the oil inlet to be connected with the lifting oil port through the feedback oil way, a second position in a middle position, a third position enabling the descending oil port to be communicated with the oil return way through the feedback oil way, and a fourth position enabling the oil inlet to be communicated with the descending oil port through the feedback oil way to achieve rapid descending; and the control valve is arranged on a valve body, and the valve body has a first closed state and a second opened state to enable the control cavity on the one-way valve to be connected with the oil return path. The utility model also has the advantages of simple structure, convenience in assembly, reliable action, long service life and the like.

Description

Technical Field

[0001] The utility model relates to a hydraulic control system for a tractor, in particular to a multi-way valve for a tractor with adjustable speed. Background Art

[0002] Agricultural machinery refers to various machinery used in the processes of crop planting and animal husbandry production, as well as in the primary processing and handling of agricultural and livestock products. Agricultural machinery includes agricultural power machinery, farmland construction machinery, soil tillage machinery, planting and fertilizing machinery, plant protection machinery, farmland irrigation and drainage machinery, crop harvesting machinery, agricultural product processing machinery, animal husbandry machinery, and agricultural transportation machinery, etc. There is a type of agricultural machinery emerging in the market currently, such as an agricultural tractor, which usually needs to achieve functions such as seeding, implement lifting and flipping, and the actions of the tractor are controlled by a hydraulic system to achieve them.

[0003] The existing multi-way valves in the agricultural machinery industry usually adopt manual control for commutation, which is difficult to operate and has low operation accuracy. The traditional multi-way valves cannot ensure precise flow control and the control of the position of the reversing valve, and it is necessary to add a pilot pressure reducing valve, proportional pressure reducing valves for each working connection to drive the reversing valve, and many complex pilot control oil circuits, and the structure is relatively complex. Moreover, in order to maintain the position or working state of the implement, a hydraulic lock is usually set. However, many existing agricultural machinery require high sealing requirements. For example, the lifting cylinder of a tractor requires high pressure holding performance. If the pressure holding performance is not good, when plowing, the plowing depth will be different, affecting the plowing effect. The control mechanism of the tractor multi-way valve has three working conditions: lifting, lowering, and floating. The conventional tractor multi-way valve has an uncontrollable speed during lowering, and the implement may descend too fast, which has potential safety hazards. And there are practical problems that the commonly used hydraulic lock to lock the lifting oil port has high machining accuracy requirements and great machining difficulty. Summary of the Utility Model

[0004] In order to solve the problem that the existing tractor implement descends too fast and has potential safety hazards in the background art, the utility model provides a multi-way valve for a tractor with adjustable speed.

[0005] The technical solution of the utility model is: a multi-way valve for a tractor with adjustable speed, including a valve body, an oil inlet, a lifting oil port, a lifting oil circuit, a lowering oil port, a feedback oil circuit, and a return oil circuit are arranged on the valve body, the lifting oil circuit is connected to the lifting oil port, and further includes:

[0006] A check valve is arranged on the lifting oil circuit; a control chamber is arranged on the check valve;

[0007] The reversing valve stem is arranged in the valve body and slidably matched with the valve body. The reversing valve stem has a first position where the oil inlet is connected to the lifting oil port through the feedback oil circuit, a second position in the middle position, a third position where the lowering oil port is connected to the oil return circuit through the feedback oil circuit, and a fourth position where the oil inlet is connected to the lowering oil port through the feedback oil circuit to achieve rapid lowering.

[0008] The control valve is arranged on the valve body. The valve body has a first state of being closed and a second state of being open to connect the control chamber on the check valve to the oil return circuit. The control valve is in the second state when the reversing valve stem is in the third position and the fourth position. The lifting oil port is connected to the oil return circuit when the reversing valve stem is in the third position.

[0009] As a further improvement of the present utility model, it further includes a throttle groove arranged on the reversing valve stem. The lifting oil port is connected to the oil return circuit through the throttle groove when the reversing valve stem is in the third position and the control valve is in the second state.

[0010] As a further improvement of the present utility model, the pressure oil at the lifting oil port opens the check valve and is connected to the oil return circuit when the reversing valve stem is in the fourth position.

[0011] As a further improvement of the present utility model, the check valve includes a valve core. A communication hole is arranged on the valve core. The lifting oil port is connected to the control chamber through the communication hole.

[0012] As a further improvement of the present utility model, an elastic member is arranged in the control chamber. The elastic member has a tendency to drive the check valve to close. An area difference is arranged on the outer surface of the valve core. The valve core has a tendency to be opened by the pressure oil at the lifting oil port after the pressure oil in the control chamber is discharged.

[0013] As a further improvement of the present utility model, it further includes a throttle hole. The communication hole is connected to the control chamber through the throttle hole.

[0014] As a further improvement of the present utility model, it further includes a connecting sleeve arranged in the valve body. A communication cavity is arranged on the connecting sleeve. One end of the communication cavity is connected to the check valve control chamber, and the other end is used to be connected to the oil return circuit. The control valve has a first state of closing to block the connection between the communication cavity and the oil return circuit and a second state of opening to connect the communication cavity to the oil return circuit.

[0015] As a further improvement of the present utility model, the control valve is a solenoid valve.

[0016] As a further improvement of the present utility model, the feedback oil circuit is connected to the oil return circuit when the reversing valve stem is in the second position for system unloading.

[0017] As a further improvement of the present utility model, it further includes a pressure compensator. When the reversing valve rod is in the first position, the oil inlet is connected to the lifting oil port through the pressure compensator and the feedback oil circuit. When the reversing valve rod is in the fourth position, the oil inlet is connected to the lowering oil port through the pressure compensator and the feedback oil circuit.

[0018] The beneficial effects of the present utility model are as follows: A control valve is provided to replace the traditional mechanical lock, with lower requirements for machining accuracy, effectively reducing the machining difficulty and production cost. At the same time, the control chamber of the check valve can be connected to the oil return circuit for oil drainage, and it can be used to lower the implement when the reversing valve rod is in the third and fourth positions, making the implement descend more smoothly. The present utility model also has the advantages of simple structure, convenient assembly, reliable operation, and long service life. Brief Description of the Drawings

[0019] Attached Figure 1 is a schematic structural diagram of an embodiment of the present utility model.

[0020] Attached Figure 2 is Figure 1 an enlarged structural diagram of part I in the attached figure.

[0021] In the figure, 1, valve body; 2, oil inlet; 3, lifting oil port; 4, lifting oil circuit; 5, lowering oil port; 6, feedback oil circuit; 7, oil return circuit; 8, check valve; 81, control chamber; 82, valve core; 83, communication hole; 84, elastic member; 85, throttle hole; 9, reversing valve rod; 91, throttle groove; 10, control valve; 11, connecting sleeve; 111, communication cavity; 12, pressure compensator. Detailed Embodiment

[0022] The following further describes the embodiments of the present utility model with reference to the drawings:

[0023] From Figure 1 Combined with Figure 2 As shown, a speed-adjustable tractor multi-way valve includes a valve body 1. The valve body 1 is provided with an oil inlet 2, a lifting oil port 3, a lifting oil circuit 4, a lowering oil port 5, a feedback oil circuit 6, and an oil return circuit 7. The lifting oil circuit 4 is connected to the lifting oil port 3, and further includes:

[0024] A check valve 8 is arranged on the lifting oil circuit 4; a control chamber 81 is provided on the check valve 8;

[0025] The reversing valve stem 9 is arranged in the valve body 1 and is in sliding fit with the valve body 1. The reversing valve stem 9 has a first position where the oil inlet 2 is connected to the lifting oil port 3 through the feedback oil circuit 6, a second position in the middle position, a third position where the lowering oil port 5 is connected to the oil return circuit 7 through the feedback oil circuit 6, and a fourth position where the oil inlet 2 is connected to the lowering oil port 5 through the feedback oil circuit 6 to achieve rapid lowering; the control valve 10 is arranged on the valve body 1. The valve body 1 has a first state where it is closed and a second state where it is opened to connect the control chamber 81 on the check valve 8 to the oil return circuit 7. The control valve 10 is in the second state when the reversing valve stem 9 is in the third position and the fourth position. The lifting oil port 3 is connected to the oil return circuit 7 when the reversing valve stem 9 is in the third position. The beneficial effect of the present utility model is that a control valve is provided to replace the traditional mechanical lock, with lower requirements for machining accuracy, effectively reducing the machining difficulty and production cost. At the same time, the control chamber of the check valve can be connected to the oil return circuit for oil discharge, and it can be used to lower the implement when the reversing valve stem is in the third position and the fourth position, so that the implement descends more smoothly. The present utility model also has the advantages of simple structure, convenient assembly, reliable operation, and long service life. Further description is made in combination with the attached drawings. In the figure, it shows the reversing valve stem in the second position at the neutral position, and the oil inlet, lifting oil port, lowering oil port, and oil return port are all not connected. The feedback oil circuit is connected to the oil return circuit, and the system is unloaded; the reversing valve stem moves left to the lifting position (the first position). The oil inlet is connected to the lifting oil port through pressure compensation and the feedback oil port, and the lowering oil port is connected to the oil return circuit. The lifting oil port discharges oil, and the lowering oil port returns oil to lift the implement; the reversing valve stem moves right to the first lowering position (the third position). The oil inlet is not connected to all oil circuits, and the lowering oil circuit and the feedback oil circuit are connected to the oil return circuit, and the system is unloaded. The lowering solenoid valve (control valve) is energized, and the lifting check valve is opened. The lifting oil port is connected to the oil return circuit through the throttle groove. According to the weight of the implement, the size of the throttle port, and the valve stem stroke, the lowering speed of the implement is adjusted; the reversing valve stem moves right to the second lowering position (the fourth position). The oil inlet is connected to the lowering oil port through pressure compensation and the feedback oil port; the lowering solenoid valve is energized, and the lifting check valve is opened. The lifting oil port is connected to the oil return circuit. The lowering oil port discharges oil, and the lifting oil port returns oil to achieve rapid lowering of the implement.

[0026] The present utility model further includes a throttle groove 91 arranged on the reversing valve stem 9. The lifting oil port 3 is connected to the oil return circuit 7 through the throttle groove 91 when the reversing valve stem 9 is in the third position and the control valve 10 is in the second state. During the actual use process, the lowering speed of the implement can be adjusted according to the weight of the implement, the size of the throttle groove, and the reversing valve stem stroke; in this way, the lowering speed of the implement can be adjusted as needed when the reversing valve stem is in the third position, and the implement descends more smoothly and reliably.

[0027] The pressure oil at the lifting oil port 3 opens the check valve 8 and is connected to the oil return circuit 7 when the reversing valve rod 9 is in the fourth position. This facilitates the rapid oil return of the lifting oil port.

[0028] The check valve 8 includes a valve core 82. A communication hole 83 is provided on the valve core 82. The lifting oil port 3 is connected to the control chamber 81 through the communication hole 83. Specifically, an elastic member 84 is provided in the control chamber 81. The elastic member 84 has a tendency to drive the check valve 8 to close. An area difference is provided on the outer surface of the valve core 82. The valve core 82 has a tendency to be opened by the pressure oil at the lifting oil port 3 after the pressure oil in the control chamber 81 is discharged. The elastic member enables the reliable closing of the check valve, with a simple structure, convenient and reliable interlocking. By cooperating with the pressure oil in the control chamber and the elastic member to press the check valve, the lifting oil port can be pressure-maintained.

[0029] The present utility model further includes a throttle hole 85. The communication hole 83 is connected to the control chamber 81 through the throttle hole 85. Specifically, the present utility model further includes a connecting sleeve 11 provided in the valve body 1. A communication chamber 111 is provided on the connecting sleeve 11. One end of the communication chamber 111 is connected to the control chamber 81 of the check valve 8, and the other end is used to be connected to the oil return circuit 7. The control valve 10 has a first state of closing to block the connection between the communication chamber 111 and the oil return circuit 7 and a second state of opening to connect the communication chamber 111 with the oil return circuit 7. Thus, when the solenoid valve operates, the control chamber can be quickly drained of oil, enabling the lifting oil port to return oil and facilitating the lowering of the implement.

[0030] The control valve 10 is a solenoid valve. This makes the control of the control valve convenient and reliable with a simple structure.

[0031] The feedback oil circuit 6 is connected to the oil return circuit 7 when the reversing valve rod 9 is in the second position for system unloading. Specifically, the present utility model further includes a pressure compensator 12. The inlet oil port 2 is connected to the lifting oil port 3 through the pressure compensator 12 and the feedback oil circuit 6 when the reversing valve rod 9 is in the first position. The inlet oil port 2 is connected to the lowering oil port 5 through the pressure compensator 12 and the feedback oil circuit 6 when the reversing valve rod 9 is in the fourth position. The setting of the pressure compensator enables the product to cooperate with different working conditions for control, with convenient and reliable control.

[0032] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model 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. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations. In addition, in the description of the present utility model, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0034] All technicians should note that although the present utility model has been described according to the above specific embodiments, the inventive concept of the present utility model is not limited to this utility model alone. Any modification using the inventive concept of the present utility model will be included in the scope of protection of the patent right of the present utility model.

Claims

1. A speed-adjustable multi-way valve for a tractor, comprising a valve body (1), wherein the valve body (1) is provided with an oil inlet (2), a lifting oil port (3), a lifting oil circuit (4), a lowering oil port (5), a feedback oil circuit (6) and an oil return oil circuit (7), wherein the lifting oil circuit (4) is connected to the lifting oil port (3), and ... circuit (4), a lowering oil port (5), a feedback oil circuit (6) and an oil return oil circuit (7), wherein the lifting oil circuit (4) is connected to the lifting oil port (3), and wherein the valve body (1) is provided with an oil inlet (2), a lifting oil circuit (4) and a lowering oil circuit (5), and wherein the lifting oil circuit (4) is connected to the lifting oil port (3), and wherein the valve body (1) is provided with an oil inlet (2), a lifting oil circuit (4) and a lowering oil circuit (5) Also included: A one-way valve (8) is provided on the lifting oil circuit (4); the one-way valve (8) is provided with a control chamber (81); A reversing valve stem (9) is arranged in the valve body (1) and is slidably matched with the valve body (1), the reversing valve stem (9) having a first position in which the oil inlet (2) is connected to the lifting oil port (3) via the feedback oil circuit (6), a second position in the middle position, a third position in which the descending oil port (5) is connected to the oil return oil circuit (7) via the feedback oil circuit (6), and a fourth position in which the oil inlet (2) is connected to the descending oil port (5) via the feedback oil circuit (6) to achieve rapid descent; A control valve (10) is provided on a valve body (1), wherein the valve body (1) has a first state of being closed and a second state of being opened so that a control chamber (81) on a one-way valve (8) is connected to an oil return line (7), wherein the control valve (10) is in the second state when the reversing valve stem (9) is in a third position and a fourth position, and the lifting oil port (3) is connected to the oil return line (7) when the reversing valve stem (9) is in the third position.

2. A speed-adjustable tractor multi-way valve according to claim 1, characterized in that It also includes a throttle groove (91) disposed on the reversing valve stem (9), and the lifting oil port (3) is connected to the oil return circuit (7) through the throttle groove (91) when the reversing valve stem (9) is in the third position and the control valve (10) is in the second state.

3. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that When the reversing valve stem (9) is in the fourth position, the pressure oil at the lifting oil port (3) opens the one-way valve (8) and is connected to the oil return line (7).

4. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that The one-way valve (8) comprises a valve core (82), the valve core (82) is provided with a communication hole (83), and the lifting oil port (3) is connected to the control chamber (81) via the communication hole (83).

5. A speed-adjustable tractor multi-way valve according to claim 4, characterized in that An elastic member (84) is provided in the control chamber (81), and the elastic member (84) has a movement tendency to drive the one-way valve (8) to close. An outer surface of the valve core (82) is provided with an area difference, and the valve core (82) has a movement tendency to be opened by the pressure oil of the lifting oil port (3) after the pressure oil in the control chamber (81) is discharged.

6. A speed-adjustable tractor multi-way valve according to claim 4, characterized in that It also includes a throttle hole (85), and the communication hole (83) is connected to the control chamber (81) via the throttle hole (85).

7. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that The control valve (10) further comprises a connecting sleeve (11) which is arranged in the valve body (1); a connecting sleeve (11) is provided with a connecting cavity (111); one end of the connecting cavity (111) is connected to the control cavity (81) of the one-way valve (8); and the other end is used to be connected to the oil return line (7); the control valve (10) has a first state in which the connecting cavity (111) and the oil return line (7) are closed and blocked, and a second state in which the connecting cavity (111) and the oil return line (7) are opened and connected.

8. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that The control valve (10) is a solenoid valve.

9. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that The feedback oil circuit (6) is connected to the oil return circuit (7) for system unloading when the reversing valve stem (9) is in the second position.

10. The speed-adjustable tractor multi-way valve according to claim 1, characterized in that It also includes a pressure compensator (12). When the reversing valve stem (9) is in the first position, the oil inlet (2) is connected to the lifting oil port (3) through the pressure compensator (12) and the feedback oil circuit (6). When the reversing valve stem (9) is in the fourth position, the oil inlet (2) is connected to the lowering oil port (5) through the pressure compensator (12) and the feedback oil circuit (6).

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