Control valve structure and hydraulic system

Abstract

The utility model relates to the technical field of hydraulic pressure, in particular to a control valve structure and a hydraulic system. A control valve structure is used for controlling a motor variable displacement mechanism and comprises a valve body; the reversing valve is assembled in the valve body, the reversing valve controls oil inlet and outlet of the variable mechanism, pilot pressure is introduced into a pilot cavity of the reversing valve, and the pilot pressure comes from motor oil port pressure and external pilot pressure; and the direct plug is detachably assembled in the valve body, and the direct plug is used for blocking an oil way from the pressure of a motor oil port to a pilot cavity of the reversing valve. The utility model also provides a hydraulic system, which comprises a motor, a hydraulic cylinder and a hydraulic cylinder, the variable displacement mechanism is used for adjusting the displacement of the motor; and the control valve structure is used for controlling the variable mechanism according to the oil port pressure of the motor and / or the external pilot pressure. The technical problem that a variable displacement motor in the prior art cannot realize switching between automatic control and external control is solved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic technology, specifically to a control valve structure and hydraulic system. Background Technology

[0002] Hydraulic motors are high-end hydraulic components, primarily used in vehicles, construction machinery, metallurgical machinery, machine tools, and other equipment. A piston motor converts the hydraulic pressure energy provided by a hydraulic pump into mechanical energy for the output shaft. The variable displacement mechanism is a crucial component in the piston motor for both direction and pressure control. When the piston motor pressure reaches the control valve's set point, the high-pressure hydraulic fluid output by the piston motor acts on the large and small chambers of the variable displacement mechanism, adjusting the piston motor's displacement. In existing closed-loop systems, the piston motor's control valve switching is controlled by an external pilot oil source, which is a supplementary oil pump in the closed-loop system. The supplementary oil pump's output pressure is the primary pressure, which cannot achieve the self-controlled hydraulic proportional variable displacement requirements of the piston motor.

[0003] For example, application number CN201410836976.2 discloses a high-pressure automatic variable control method and control valve device with hydraulic overload. A pilot hydraulic control is added to the tail end of the high-pressure automatic control valve core of the variable motor. When the motor has no external hydraulic control pressure, the high-pressure automatic variable control setting point is relatively high. When a pilot hydraulic control pressure is manually applied, the high-pressure automatic variable control setting point continuously decreases as the pilot pressure increases; essentially, it realizes both automatic and manual control of the motor. The area difference design of the spool valve core allows the valve core to have a direct pressure response to the pilot hydraulic control pressure and can quickly transmit it to the high-pressure oil port of the motor.

[0004] The motor described in the above document can be controlled automatically or externally, but cannot switch between the two. Utility Model Content

[0005] To address the technical problem that existing variable displacement motors cannot switch between automatic and external control, this invention provides a control valve structure and hydraulic system that solves the aforementioned technical problem.

[0006] To solve the above-mentioned technical problems, this utility model provides a control valve structure for controlling a motor variable mechanism, comprising:

[0007] Valve body;

[0008] A reversing valve is assembled in the valve body. The reversing valve controls the inlet and outlet of oil in the variable mechanism. The pilot chamber of the reversing valve introduces pilot pressure, which comes from the motor oil port pressure and the external pilot pressure.

[0009] A direct plug, detachably mounted in the valve body, is used to block the oil passage from the motor port pressure to the pilot chamber of the directional valve.

[0010] According to one embodiment of the present invention, a pressure reducing valve is also included, wherein the pilot pressure is reduced by the pressure reducing valve and then enters the pilot chamber of the reversing valve.

[0011] According to one embodiment of the present invention, the pressure reducing valve includes a pressure reducing valve core. An elastic element and an electromagnetic component are respectively disposed on both sides of the pressure reducing valve core. A first oil port, a second oil port, and a third oil port are formed on the outer periphery of the pressure reducing valve core. The first oil port introduces pilot pressure, the second oil port communicates with the pilot chamber of the directional valve, and the third oil port communicates with the oil tank. The second oil port also communicates with the elastic chamber where the elastic element is located. In the initial state, under the action of the elastic element, the second oil port and the third oil port are connected, causing the pilot chamber of the directional valve to be in a low-pressure state. After energization and reversal, the first oil port and the second oil port are connected, and the pilot chamber of the directional valve is in a high-pressure state.

[0012] According to one embodiment of the present invention, the valve body is provided with an external pilot oil port and a pressure oil port. The external pilot oil port introduces external pilot pressure, and the pressure oil port introduces motor oil port pressure. The oil passage from the pressure oil port to the end section of the pressure reducing valve is on the same straight line as the external pilot oil passage from the external pilot oil port to the pressure reducing valve. The straight plug enters the end section of the oil passage through the external pilot oil port to achieve the blocking effect.

[0013] According to one embodiment of the present invention, there are two pressure oil ports, which are respectively connected to two oil ports of the motor, and the oil is introduced into the two pressure oil ports and then flows together.

[0014] According to one embodiment of the present invention, the pressure reducing valve and the reversing valve are arranged vertically.

[0015] According to one embodiment of the present invention, the reversing valve includes a reversing valve core, one end of which forms a pilot chamber. When the pilot chamber of the reversing valve is in a low-pressure state, the control port of the variable mechanism is connected to the oil tank through the reversing valve. When the pilot chamber of the reversing valve is in a high-pressure state, causing the reversing valve to switch, the control port of the variable mechanism is connected to two oil ports of the motor through the reversing valve, and high-pressure oil is introduced into the control port of the variable mechanism.

[0016] According to one embodiment of the present invention, the valve body is further provided with an auxiliary oil port, which introduces auxiliary high-pressure oil to the reversing valve.

[0017] This utility model also provides a hydraulic system, including:

[0018] The motor has two oil ports;

[0019] A variable displacement mechanism is used to adjust the motor's displacement.

[0020] The control valve structure controls the variable mechanism based on the oil port pressure of the motor and / or the external pilot pressure.

[0021] Based on the above technical solution, the technical effects that this utility model can achieve are as follows:

[0022] The control valve structure of this utility model introduces pilot pressure into the pilot chamber of the directional valve from the motor port pressure and external pilot pressure. A detachable straight plug is installed to select the pilot pressure, thereby enabling switching between automatic and external control. Specifically, the external pilot pressure generally comes from the closed-loop system's make-up pump, which is for external control, while the motor port pressure comes from the motor port, which is for automatic control. By installing the straight plug, the motor port pressure cannot enter the pilot chamber of the directional valve; only the external pilot pressure enters, achieving external control. Removing the straight plug allows both the motor port pressure and the external pilot pressure to enter the pilot chamber of the directional valve simultaneously, achieving both automatic and external control. Removing the straight plug and simultaneously shutting down the make-up pump enables automatic control. In other words, the control valve structure of this utility model can switch between three modes: external control, automatic control, and a combination of both.

[0023] The control valve structure of this utility model specifically sets the oil passage from the pressure port to the end of the pressure reducing valve and the oil passage from the external pilot port to the pressure reducing valve to be on the same straight line. The straight plug is set on the oil passage from the pressure port to the end of the pressure reducing valve. When disassembling and assembling the straight plug, the pressure reducing valve can be removed, and the straight plug can be disassembled and assembled by inserting it from the external pilot port. The pressure reducing valve is assembled by cartridge, which is convenient for disassembly and assembly.

[0024] The control valve structure of this utility model is also equipped with a pressure reducing valve. The pressure reducing valve can reduce the pilot pressure to prevent the oil pressure entering the pilot chamber of the directional valve from being too high, impacting the directional valve and causing structural damage.

[0025] The control valve structure of this utility model has one oil port at high pressure and the other oil port at low pressure when the motor is working. There are two pressure oil ports, which are respectively connected to the two oil ports of the motor to ensure the high pressure of the oil introduced into the motor. The valve body is also provided with an auxiliary oil port. When the pressure of the two oil ports of the motor is too low, the auxiliary oil port can be used to provide auxiliary high pressure oil.

[0026] The hydraulic system of this utility model is designed with a valve body and its corresponding flow channel, and adds a direct plug and a pressure reducing valve to realize the selection of pilot pressure, complete the switching of control mode, and at the same time avoid the impact of high pressure oil on the reversing valve. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the control valve structure of this utility model;

[0028] Figure 2 This is a schematic diagram of the control valve structure from another perspective.

[0029] Figure 3 This is a cross-sectional view of the control valve structure;

[0030] Figure 4 This is a cross-sectional view of the control valve structure at the directional valve location;

[0031] Figure 5 This is a cross-sectional view of the control valve structure at the pressure reducing valve location;

[0032] Figure 6 Hydraulic schematic diagram of the control valve structure;

[0033] Figure 7 The current-pressure curve of the pressure reducing valve;

[0034] In the diagram: 1-Valve body; 11-Pressure port; 111-First pressure port; 112-Second pressure port; 12-External pilot port; 13-Working port; 14-Return port; 15-Auxiliary port; 16-Final oil circuit; 17-External pilot oil circuit; 2-Directional control valve; 21-Directional control valve core; 22-Directional control valve sleeve; 23-Pilot chamber; 3-Pressure reducing valve; 31-Pressure reducing valve core; 32-Pressure reducing valve sleeve; 33-Elastic element; 34-Solenoid assembly; 4-Direct plug. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present utility model or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0036] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0038] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0039] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0040] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0041] like Figure 1-7 As shown, this embodiment provides a control valve structure, including a valve body 1, a directional valve 2, and a direct plug 4. The directional valve 2 and the direct plug 4 are assembled inside the valve body 1. The directional valve 2 controls the inlet and outlet oil of the variable mechanism of the motor. The pilot chamber 23 of the directional valve 2 introduces pilot pressure, which comes from the motor port pressure and external pilot pressure. The direct plug 4 is detachably assembled in the oil line from the motor port pressure to the pilot chamber 23 of the directional valve 2. When the direct plug 4 is assembled in the oil line from the motor port pressure to the pilot chamber 23 of the directional valve 2, it can block the oil line, preventing the motor port pressure from reaching the pilot chamber 23 of the directional valve 2. The pilot chamber 23 of the directional valve 2 can only introduce external pilot pressure to achieve external control. When the direct plug 4 is removed, the pilot chamber 23 of the directional valve 2 can introduce both the motor port pressure and the external pilot pressure to achieve automatic control and external control. After the direct plug 4 is removed, the closed-loop system replenishment pump can also be shut down to stop the pumping of pilot pressure, thus achieving automatic control.

[0042] like Figure 1-2 As shown, the valve body 1 is block-shaped with an installation space inside for assembling the directional valve 2. Multiple oil ports are formed on the outer surface of the valve body 1 to facilitate the entry and exit of oil into the control valve structure. Multiple oil passages are formed inside the valve body 1 to facilitate the flow of oil.

[0043] Specifically, the valve body 1 has a pressure port 11 and an external pilot port 12. The pressure port 11 is used to introduce motor oil pressure, and the external pilot port 12 is used to introduce external pilot pressure. Corresponding to the two motor oil ports, there are two pressure ports 11, namely a first pressure port 111 and a second pressure port 112. The first pressure port 111 and the second pressure port 112 are respectively connected to the two motor oil ports, introducing the first pressure oil P1 and the second pressure oil P2 into the two motor oil ports. The external pilot port 12 is connected to external pilot oil X. The valve body 1 also has a working port 13, which is used to connect to the control port A of the motor's variable displacement mechanism; the valve body 1 also has a return port 14, which is connected to the oil tank T.

[0044] As a preferred embodiment, after the first pressure oil port 111 and the second pressure oil port 112 respectively introduce the first pressure oil P1 and the second pressure oil P2, the first pressure oil P1 and the second pressure oil P2 flow together through the oil passage inside the valve body 1 to the reversing valve 2. Specifically, after the first pressure oil P1 and the second pressure oil P2 flow together, they are supplied as internal pilot oil to the pilot chamber 23 of the reversing valve 2, and also supplied to the outer periphery of the reversing valve 2 through the oil passage. Under the control of the reversing valve 2, they enter the control oil port A of the variable mechanism to realize the displacement control of the motor.

[0045] like Figure 3 , 4As shown in Figure 6, the directional valve 2 controls the inlet and outlet of the control port A of the variable mechanism of the motor. When the pilot chamber 23 of the directional valve 2 is in a low-pressure state, the control port A of the variable mechanism is connected to the oil tank T through the directional valve 2, and the control port A of the variable mechanism returns oil. When the pilot chamber 23 of the directional valve 2 is in a high-pressure state, causing the directional valve 2 to switch, the directional valve 2 controls the control port A of the variable mechanism to enter oil.

[0046] As a preferred embodiment, the directional valve 2 is a two-position three-way valve. The directional valve 2 includes a directional valve core 21 and a directional valve sleeve 22. The directional valve sleeve 22 is assembled inside the valve body 1, and the directional valve core 21 is slidably assembled inside the directional valve sleeve 22. The directional valve sleeve 22 has a fourth oil port d, a fifth oil port e, and a sixth oil port f. The first pressure oil P1 and the second pressure oil P2 flow together to the fourth oil port d. The fifth oil port e is connected to the working oil port 13, and then to the control oil port A of the variable mechanism of the motor. The sixth oil port f is connected to the return oil port 14, and then to the oil tank T. One end of the directional valve core 21 is provided with an elastic component (not shown in the figure), and the other end of the directional valve core 21 forms a pilot chamber 23. When the pilot chamber 23 is under low pressure, the directional valve core 21 is in its initial state under the action of the elastic component, and the fifth oil port e is connected to the sixth oil port f, that is, the control oil port A of the motor's variable mechanism is connected to the oil tank T. When the pilot chamber 23 is under high pressure, the directional valve core 21 reverses direction against the action of the elastic component, and the fifth oil port e is connected to the fourth oil port d, that is, the control oil port A of the motor's variable mechanism is connected to the first pressure oil P1 and the second pressure oil P2 of the motor. High-pressure oil is introduced into the control oil port A, thereby adjusting the motor's displacement. Preferably, an auxiliary oil port 15 is also provided on the valve body 1, and the auxiliary oil port 15 introduces auxiliary high-pressure oil G to the fourth oil port d of the directional valve 2. When the oil pressure of the first pressure oil P1 and the second pressure oil P2 is low, auxiliary high-pressure oil G can be provided through the auxiliary oil port 15.

[0047] like Figure 1-2 As shown, a pressure reducing valve 3 is also provided on the valve body 1. The motor oil port pressure and pilot pressure are reduced by the pressure reducing valve 3 and then enter the pilot chamber 23 of the directional valve 2. Figure 5 As shown, the pressure reducing valve 3 includes a pressure reducing valve core 31 and a pressure reducing valve sleeve 32. The pressure reducing valve sleeve 32 is assembled inside the valve body 1, and the pressure reducing valve core 31 is slidably assembled inside the pressure reducing valve sleeve 32. An elastic element 33 and an electromagnetic component 34 are respectively provided at both ends of the pressure reducing valve core 31. The pressure reducing valve core 31 is switched under the control of the elastic element 33 and the electromagnetic component 34. When the pressure reducing valve core 31 is in its initial state under the action of the elastic element 33, the pilot chamber 23 of the reversing valve 2 is connected to the oil tank T, and the pilot chamber 23 is in a low-pressure state. When the electromagnetic component 34 is energized, the pressure reducing valve core 31 switches, and the pilot chamber 23 of the reversing valve 2 introduces the motor oil port pressure and the pilot pressure, and the pilot chamber 23 is in a high-pressure state.

[0048] As a preferred technical solution in this embodiment, the pressure reducing valve 3 can be a two-position three-way valve. The valve sleeve 32 of the pressure reducing valve has a first oil port a, a second oil port b and a third oil port c. The first oil port a is connected to the pilot pressure, that is, the first pressure oil P1 and the second pressure oil P2 flow into the first oil port a after merging. The external pilot oil X also enters the first oil port a through the external pilot oil passage 17. The second oil port b is connected to the pilot chamber 23 of the reversing valve 2. The second oil port b is also connected to the spring chamber where the elastic element 33 is located. The third oil port c is connected to the oil tank T. When the electromagnetic component 34 is not energized, the pressure reducing valve core 31 is in its initial state under the action of the elastic element 33, the second oil port b is connected to the third oil port c, the pilot chamber 23 is connected to the oil tank T, and the pilot chamber 23 is in a low-pressure state; when the electromagnetic component 34 is energized, the electromagnetic valve core 31 overcomes the action of the elastic element 33 under the action of the electromagnetic component 34 and reverses, at this time, the second oil port b is connected to the first oil port a, the pilot chamber 23 introduces pilot pressure, and is in a high-pressure state.

[0049] As a preferred technical solution in this embodiment, the pressure reducing valve 3 can be a proportional pressure reducing valve. Figure 7 The corresponding current-pressure curve controls the pressure at the second port b proportionally to the magnitude of the input current to the electromagnet. When no current is applied to the electromagnet, the first port a is closed, and the second port b is connected to the third port c. When current is applied to the electromagnet, the second port b is connected to the first port a, and the pressure at the second port b increases proportionally with the increase of the control current. When the current stabilizes, the pressure at the second port b continues to rise due to external force, causing the pressure reducing valve core 31 to slide, closing the first port a and temporarily connecting the second port b to the third port c. This continues until the pressure at the second port b decreases to a reasonable range, at which point the connection between the second port b and the first port a is restored, and the third port c is closed.

[0050] As a preferred technical solution in this embodiment, the pressure reducing valve 3 is inserted into the valve body 1; the pressure reducing valve 3 and the reversing valve 2 are arranged perpendicularly, specifically, the axis of the pressure reducing valve 3 and the axis of the reversing valve 2 are perpendicular and do not intersect.

[0051] like Figure 3 As shown, the direct plug 4 is located inside the valve body 1 to block the oil passage from the motor oil port pressure to the pilot chamber 23 of the directional valve 2. Specifically, the direct plug 4 is located on the oil passage from the first pressure oil P1 to the second pressure oil P2 after they merge and flow to the pressure reducing valve 3.

[0052] As a preferred technical solution in this embodiment, the straight plug 4 is installed on the final oil passage 16 of the pressure reducing valve 3 after the first pressure oil P1 and the second pressure oil P2 merge. Specifically, the external pilot oil X enters through the external pilot oil port 12 and then reaches the first oil port a of the pressure reducing valve 3 through the straight-extending external pilot oil passage 17; the final oil passage 16 of the pressure reducing valve 3 after the first pressure oil P1 and the second pressure oil P2 merge is also a straight-extending passage, and the final oil passage 16 and the external pilot oil passage 17 are located on the same straight line and are connected through the mounting cavity of the pressure reducing valve 3. The pressure reducing valve 3 is installed on the valve body 1 by means of a cartridge, and the electromagnetic component 34 of the pressure reducing valve 3 is located outside the valve body 1. The installation and removal of the pressure reducing valve 3 on the valve body 1 are relatively convenient. When disassembling and assembling the straight plug 4, simply remove the pressure reducing valve 3, and then push the straight plug 4 in through the external pilot port 12. The straight plug 4 passes through the external pilot oil passage 17 and the mounting cavity of the pressure reducing valve 3 into the final oil passage 16. The straight plug 4 is installed on the final oil passage 16, forming a blockage on the final oil passage 16. The straight plug 4 can be threaded onto the final oil passage 16. Preferably, the final oil passage 16 is also provided with a limiting step surface to limit the position of the straight plug 4 on the final oil passage 16.

[0053] This embodiment also provides a hydraulic system, including a motor, a variable displacement mechanism, and the aforementioned control valve structure. The control valve structure controls the variable displacement mechanism based on the oil port pressure of the motor and / or the external pilot pressure. The variable displacement mechanism is used to adjust the displacement of the motor.

[0054] Specifically, the first pressure port 111 and the second pressure port 112 of the valve body 1 are respectively connected to the two ports of the motor, the working port 13 on the valve body 1 is connected to the control port A of the variable mechanism; the external pilot port 12 is connected to the make-up oil pump to introduce external pilot oil X; the return oil port 14 is connected to the oil tank T; and the auxiliary oil port 15 introduces auxiliary high-pressure oil G.

[0055] Based on the above technical solution, the working mode of the hydraulic system in this embodiment is as follows:

[0056] Operating Mode 1: The pilot pressure of the control valve structure is taken from the external pilot pressure, that is, from the external pilot oil X. The specific operating method is as follows:

[0057] The straight plug 4 is installed on the final oil passage 16, which blocks the oil passage from the first pressure oil P1 and the second pressure oil P2 to the pressure reducing valve 3 after they merge.

[0058] When the solenoid component 34 of the pressure reducing valve 3 is not energized and is in a state such as Figure 6 When in the right position as shown, the second port b of the pressure reducing valve 3 is connected to the third port c, and the pilot chamber 23 of the directional valve 2 is connected to the oil tank T via the pressure reducing valve 3. The pilot chamber 23 is in a low-pressure state, and the directional valve 2 is in the position shown. Figure 6As shown in the lower position, at this time, the fifth oil port e is connected to the sixth oil port f, and the control oil port A is connected to the oil tank T through the reversing valve 2, and the motor is in the maximum displacement state.

[0059] When the solenoid component 34 of the pressure reducing valve 3 is energized and is in a state such as Figure 6 When the left position is shown, the second oil port b of the pressure reducing valve 3 is connected to the first oil port a, and the pilot chamber 23 of the reversing valve 2 enters the high pressure oil through the pressure reducing valve 3. The reversing valve 2 is in the upper working state. At this time, the fifth oil port e is connected to the fourth oil port d, and the control oil port A is connected to the first pressure oil P1, the second pressure oil P2, and the auxiliary high pressure oil G. The motor is at its minimum displacement.

[0060] When the oil pressure at the first oil port a exceeds the set pressure, the pressure reducing valve 3 will switch between left and right positions. Through the pressure reducing valve 3, the requirements of the motor hydraulic proportional variable and the secondary protection requirements when the pressure is over-adjusted are achieved.

[0061] In operating mode two, the pilot pressure of the control valve structure is taken from the motor oil port pressure, that is, from the first pressure oil P1 and the second pressure oil P2; the specific operating method is as follows:

[0062] Cancellation of the direct plug 4 can block the external pilot oil port 12, and the external pilot oil X is closed; the aforementioned external pilot oil X is replaced by the first pressure oil P1 and the second pressure oil P2, and the working process of working mode one sequentially realizes the functions of pressure reducing valve 3 and reversing valve 2.

[0063] In working mode three, the pilot pressure of the control valve structure is simultaneously taken from the external pilot pressure and the motor oil port pressure. The direct plug 4 is canceled, and external pilot oil X is introduced at the same time. The working process of working mode one realizes the functions of pressure reducing valve 3 and reversing valve 2 in sequence.

[0064] Based on the above technical solution, users can select the pilot pressure switching mode according to actual usage needs, and realize the switching between three working modes: motor self-control, external control, automatic and external control.

[0065] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A control valve structure for controlling a motor variable displacement mechanism, characterized in that, include: Valve body (1); A reversing valve (2) is assembled inside the valve body (1). The reversing valve (2) controls the inlet and outlet of the variable mechanism. The pilot chamber (23) of the reversing valve (2) introduces pilot pressure, which comes from the motor oil port pressure and the external pilot pressure. A straight plug (4) is detachably assembled inside the valve body (1). The straight plug (4) is used to block the oil passage from the motor oil port pressure to the pilot chamber (23) of the directional valve (2).

2. The control valve structure according to claim 1, characterized in that, It also includes a pressure reducing valve (3), and the pilot pressure is reduced by the pressure reducing valve (3) and then enters the pilot chamber (23) of the reversing valve (2).

3. The control valve structure according to claim 2, characterized in that, The pressure reducing valve (3) includes a pressure reducing valve core (31). An elastic element (33) and an electromagnetic component (34) are respectively provided on both sides of the pressure reducing valve core (31). A first oil port a, a second oil port b and a third oil port c are formed on the outer periphery of the pressure reducing valve core (31). The first oil port a introduces pilot pressure. The second oil port b is connected to the pilot chamber (23) of the reversing valve (2). The third oil port c is connected to the oil tank T. The second oil port b is also connected to the elastic chamber where the elastic element (33) is located. In the initial state, under the action of the elastic element (33), the second oil port b is connected to the third oil port c, so that the pilot chamber (23) of the reversing valve (2) is in a low-pressure state. After being energized and reversed, the first oil port a is connected to the second oil port b, and the pilot chamber (23) of the reversing valve (2) is in a high-pressure state.

4. A control valve structure according to any one of claims 2-3, characterized in that, The valve body (1) is provided with an external pilot port (12) and a pressure port (11). The external pilot port (12) introduces external pilot pressure, and the pressure port (11) introduces motor port pressure. The end oil passage (16) from the pressure port (11) to the pressure reducing valve (3) and the external pilot oil passage (17) from the external pilot port (12) to the pressure reducing valve (3) are on the same straight line. The straight plug (4) enters the end oil passage (16) through the external pilot port (12) to achieve the blocking effect.

5. A control valve structure according to claim 4, characterized in that, There are two pressure oil ports (11), which are respectively connected to the two oil ports of the motor. After the oil is introduced into the two pressure oil ports (11), the oil flows together.

6. A control valve structure according to any one of claims 2-3, characterized in that, The pressure reducing valve (3) and the reversing valve (2) are arranged vertically.

7. The control valve structure according to claim 1, characterized in that, The reversing valve (2) includes a reversing valve core (21), one end of which forms a pilot chamber (23). When the pilot chamber (23) of the reversing valve (2) is in a low-pressure state, the control port A of the variable mechanism is connected to the oil tank T through the reversing valve (2). When the pilot chamber (23) of the reversing valve (2) is in a high-pressure state, causing the reversing valve (2) to switch, the control port A of the variable mechanism is connected to the two oil ports of the motor through the reversing valve (2), and high-pressure oil is introduced into the control port A of the variable mechanism.

8. The control valve structure according to claim 1, characterized in that, The valve body (1) is also provided with an auxiliary oil port (15), which introduces auxiliary high-pressure oil G to the reversing valve (2).

9. A hydraulic system, characterized in that, include: The motor has two oil ports; A variable displacement mechanism is used to adjust the motor's displacement. The control valve structure according to any one of claims 1-8 controls the variable mechanism based on the oil port pressure of the motor and / or the external pilot pressure.

Images