Pilot follow-up proportional valve

Abstract

The invention relates to the technical field of hydraulic valves, in particular to a pilot follow-up proportional valve. The pilot proportional valve comprises a valve sleeve, the valve sleeve is provided with a containing cavity penetrating through the two ends of the valve sleeve along the axis of the valve sleeve, the containing cavity comprises a control subsection, a liquid inlet subsection and a liquid outlet subsection, and the liquid inlet subsection and the liquid outlet subsection are provided with a liquid inlet and a liquid outlet respectively; the main valve core moves between an opening position for communicating the liquid inlet subsection and the liquid outlet subsection and a closing position for separating the liquid inlet subsection and the liquid outlet subsection, and the main valve core is provided with a pressure relief hole channel penetrating through the two ends of the main valve core along the axis of the main valve core; the valve sleeve is provided with a first hole channel and a second hole channel which are communicated with the control subsection so as to drive the main valve element to move. The main valve element is provided with a first through hole communicating with the pressure relief hole channel and the control subsection in the radial direction. The pressure relief hole channel is provided with a pilot valve element moving in the axial direction of the pressure relief hole channel and used for controlling the on-off state of the first through hole and the pressure relief hole channel.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic valves, in particular to a pilot follower proportional valve. Background Art

[0002] At present, the pilot follower proportional valve can realize proportional control of the valve opening, but the method it adopts is: the valve sleeve is connected with the main valve core sleeve, and a control segment is formed at the left and right ends of the main valve core respectively. The pilot circuit connects the two control segments, and the pressure reducing valve arranged in the pilot circuit adjusts the pressure of the liquid entering the two control segments, thereby controlling the displacement of the main valve core to realize proportional control of the valve opening.

[0003] However, this method requires maintaining a pressure balance in the two control sections, and unstable valve core oscillation is prone to occur during use. It is difficult to control and not only requires an additional pressure reducing valve, but also requires high-precision processing and matching of parts. The processing is difficult and greatly increases the cost. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a pilot follower proportional valve to simplify the structure of the pilot proportional valve, improve the stability of the valve core movement, reduce the control difficulty, and ensure the consistency of the opening and closing characteristics.

[0005] The present invention provides a pilot follower proportional valve, comprising: A valve sleeve, wherein the valve sleeve is provided with a cavity penetrating through both ends thereof along its axis, the cavity comprising a control segment, a liquid inlet segment and a liquid outlet segment, the liquid inlet segment and the liquid outlet segment are respectively provided with a liquid inlet and a liquid outlet; A main valve core moves between an open position connecting the liquid inlet segment and the liquid outlet segment and a closed position separating the liquid inlet segment and the liquid outlet segment, and the main valve core is provided with a pressure relief channel extending along its axis; Among them, the valve sleeve is provided with a first channel and a second channel which are connected with the control segment to drive the main valve core to move; the main valve core is provided with a first through hole which radially connects the pressure relief channel with the control segment; the pressure relief channel is provided with a pilot valve core which moves along its axial direction, for controlling the on-off state of the first through hole and the pressure relief channel.

[0006] A pilot follower proportional valve provided by the present invention further includes a driving device connected to the pilot valve core and fixed at the left end of the chamber, for driving the pilot valve core to move relative to the pressure relief channel; The pilot valve core is provided with a second through hole extending from its end surface to its side wall, and the second through hole is located on the right side of the first through hole, so that the pilot valve core has an initial position that separates the first through hole from the pressure relief channel.

[0007] According to a pilot follower proportional valve provided by the present invention, the pressure relief channel is provided with a balancing groove extending along the circumference of its side wall, and the first through hole extends from the bottom surface of the balancing groove to the control segment; When the end of the pilot valve core moves to the right side of the balancing groove, the balancing groove forms an annular cavity around the pilot valve core.

[0008] According to a pilot follower proportional valve provided by the present invention, the main valve core is provided with a control portion sliding in the control segment, and the valve sleeve is provided with a first hole and a second hole for conveying liquid into the control segment to drive the main valve core to move; When the liquid flow rate entering the control segment from the first hole is greater than the liquid flow rate discharged from the control segment from the second through hole, the main valve core moves to the right; or when the liquid flow rate entering the control segment from the first hole is less than the liquid flow rate discharged from the control segment from the second through hole, the main valve core moves to the left; The first channel is connected from the outside of the valve sleeve to the left side of the control segment, the second channel is connected from the liquid inlet to the right side of the control segment, and the pipeline is connected with the first channel and the second channel.

[0009] According to a pilot follower proportional valve provided by the present invention, a liquid return section with a liquid return port is further provided at the right end of the cavity, the valve sleeve is provided with a cylindrical portion in the liquid return section, an annular gap is provided between the cylindrical portion and the inner wall of the liquid return section, and the right end of the main valve core is slidably inserted in the cylindrical portion.

[0010] A pilot follower proportional valve provided according to the present invention also includes a liquid return valve core slidably mounted on the outside of the cylindrical portion, and the liquid return valve core moves between an open position connecting the liquid outlet segment and the liquid return segment and a closed position separating the liquid outlet segment and the liquid return segment.

[0011] According to a pilot follower proportional valve provided by the present invention, a third channel is provided on the right side of the liquid return segment, which is used to transport liquid into the annular space between the cylindrical portion and the liquid return segment to drive the liquid return valve core to move; A reversing valve is provided between the third hole and the liquid return port, for controlling whether the third hole is connected to the liquid return port or to the pipeline.

[0012] According to a pilot follower proportional valve provided by the present invention, a sealing member is further provided on the side wall of the pressure relief channel, and two of the sealing members are respectively located on the left and right sides of the balancing groove.

[0013] According to a pilot follower proportional valve provided by the present invention, the chamber is provided with a guide segment, the guide segment is located on the left side of the control segment, the cross-sectional diameter of the guide segment is smaller than the cross-sectional diameter of the control segment, and the first channel is located adjacent to the guide segment and the control segment; The left end of the main valve core is arranged as a guide portion cooperating with the guide segment, and the guide portion is slidably plugged into the guide segment.

[0014] According to a pilot follower proportional valve provided by the present invention, the pipeline is controlled to deliver high-pressure liquid to the control segment, driving the pilot valve core to move a set distance to the left, and repeating the above movement process until the main valve core reaches a preset opening.

[0015] The above one or more technical solutions in the present invention have at least one of the following technical effects: The sliding of the pilot valve core can make the first through hole connected with the control segment, and then the liquid in the control segment is discharged through the pressure relief channel, so that the opening force on the main valve core is greater than the closing force, and the main valve core slides to the left to connect the liquid inlet segment with the liquid outlet segment. When the pilot follower proportional valve is in the open state, the slight movement of the pilot valve core will change the pressure of the control segment, and then change the force balance state of the main valve core, so that the main valve core will move almost simultaneously with the pilot valve core, which improves the response speed of the pilot follower proportional valve and ensures that it has high control accuracy, stability and consistency.

[0016] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted, and the advantages brought about by the technical features of these technical solutions described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic diagram of a pilot follower proportional valve provided in an embodiment of the present invention in an initial state (the main valve core liquid inlet is closed).

[0019] Figure 2 A schematic diagram of a pilot valve core of a pilot follower proportional valve provided in an embodiment of the present invention moving to a critical state (a main valve core liquid inlet is about to open).

[0020] Figure 3 A schematic diagram of the pilot valve core of the pilot follower proportional valve provided in an embodiment of the present invention moving to the point where the first through hole is connected to the second through hole (opening process of the main valve core liquid inlet).

[0021] Figure 4 A schematic diagram of a pilot valve core of a pilot follower proportional valve provided in an embodiment of the present invention moving to a balanced state (the main valve core stops moving).

[0022] Reference numerals: 100, valve sleeve; 110, accommodating cavity; 120, guide segment; 130, control segment; 131, first channel; 140, liquid inlet segment; 141, liquid inlet port; 142, second channel; 150, liquid outlet segment; 151, liquid outlet port; 160, liquid return segment; 161, liquid return port; 162, third channel; 170, cylindrical portion; 200, main valve core; 210, pressure relief channel; 211, balancing groove; 212, sealing element; 220, first through hole; 230, guide portion; 240, control portion; 300, pilot valve core; 310, second through hole; 400, liquid return valve core; 500, pipeline; 600, drive device; 700, reversing valve; 800, throttle valve. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0026] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0028] In the present invention, the pilot proportional valve refers to a device that combines the functions of a pilot valve and a main valve and can adjust the flow rate or pressure of a fluid according to an input signal (usually an electrical signal) to more accurately control the flow rate of the supplied fluid and achieve continuous and precise adjustment of components such as hydraulic cylinders and hydraulic supports.

[0029] like Figure 1 As shown, in the embodiment of the present invention, a pilot follower proportional valve is introduced, wherein the pilot follower proportional valve mainly comprises: a valve sleeve 100, a main valve core 200, a pilot valve core 300, a liquid return valve core 400, and a driving device 600.

[0030] Specifically, the valve sleeve 100 is provided with a cavity 110 that passes through both ends thereof along its axis. The cavity 110 is sequentially provided from left to right with a guide segment 120, a control segment 130, a liquid inlet segment 140, a liquid outlet segment 150, and a liquid return segment 160. The liquid inlet segment 140, the liquid outlet segment 150, and the liquid return segment 160 are provided with a liquid inlet 141, a liquid outlet 151, and a liquid return segment 161, respectively.

[0031] The main valve core 200 moves between an open position connecting the liquid inlet segment 140 and the liquid outlet segment 150 and a closed position separating the liquid inlet segment 140 and the liquid outlet segment 150. The main valve core 200 is provided with a pressure relief channel 210 extending along its axis.

[0032] In addition, the valve sleeve 100 is provided with a first hole 131 and a second hole 142 which are connected to the control segment 130 to drive the main valve core 200 to move. A pipeline 500 which is connected to the first hole 131 and the liquid inlet 141 is provided outside the valve sleeve 100. The pipeline 500 is connected to the first hole 131 and the second hole 142 respectively. The main valve core 200 is provided with a first through hole 220. The first through hole 220 is extended along the radial direction of the main valve core 200 and penetrates the side wall of the main valve core 200. Thus, the first through hole 220 connects the control segment 130 with the pressure relief hole 210.

[0033] In addition, a pilot valve core 300 is provided in the pressure relief channel 210 to cooperate with the pressure relief channel 210 and slide along the axial direction thereof. The left end of the pilot valve core 300 protrudes from the left end of the pressure relief channel 210, and the right end of the pilot valve core 300 is embedded in the pressure relief channel 210. The right end of the pilot valve core 300 can reciprocate between the left and right sides of the first through hole 220 to control the on-off state of the first through hole 220 and the pressure relief channel 210.

[0034] Furthermore, the main valve core 200 is provided with a pressure relief channel 210 passing through both ends thereof along its axis.

[0035] In this embodiment, the sliding of the pilot valve core 300 can make the first through hole 220 communicate with the control segment 130, and then the liquid in the control segment 130 is discharged through the pressure relief channel 210, so that the opening force on the main valve core 200 is greater than the closing force, and the main valve core 200 slides to the left to connect the liquid inlet segment 140 with the liquid outlet segment 150. When the pilot follower proportional valve is in the open state, a slight movement of the pilot valve core 300 will change the pressure of the control segment 130, and then change the force balance state of the main valve core 200, so that the main valve core 200 will move almost simultaneously with the pilot valve core 300, thereby improving the response speed of the pilot follower proportional valve and ensuring that it has high control accuracy, stability and consistency.

[0036] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0037] In order to accurately control the moving distance of the pilot valve core 300 in the pressure relief channel 210, a driving device 600 is provided at the left end of the valve sleeve 100. The driving device 600 is connected to the pilot valve core 300 and is used to drive the pilot valve core 300 to move relative to the pressure relief channel 210. Preferably, the driving device 600 is fixed at the left end of the cavity 110 and is arranged to coincide with the central axis of the cavity 110.

[0038] Furthermore, a second through hole 310 is provided at the right end of the pilot valve core 300, for allowing the pilot valve core 300 to slide smoothly in the pressure relief channel. The second through hole 310 extends from the right end surface of the pilot valve core 300 to the side wall of the pilot valve core 300. When the pilot valve core 300 is in the initial position, the second through hole 310 is located on the right side of the first through hole 220, for allowing the pilot valve core 300 to separate the first through hole 220 from the pressure relief channel 210.

[0039] In addition, the driving device 600 is rigidly connected to the pilot valve core 300. Figure 1 In the position shown, the second through hole 310 of the pilot valve core 300 is isolated from the control segment 130, and the pressure of the liquid in the portion of the control segment 130 located on the left side of the main valve core 200 is equal to the inlet pressure of the pipeline 500. The pressure of the liquid in the portion of the control segment 130 located on the right side of the main valve core 200 is also equal to the inlet pressure of the pipeline 500 because it is connected to the liquid inlet 141 through the second hole 142.

[0040] However, the annular area of ​​the left control segment 130 of the main valve core 200 is larger than that of the right control segment 130 of the main valve core 200, so the combined force on the main valve core 200 is directed to the right. The main valve core 200 and the cavity 110 are sealed by the conical surface to separate the liquid inlet 141 and the liquid outlet 151.

[0041] Furthermore, by driving the pilot valve core 300 to slide in the pressure relief channel 210 through the driving device 600 , the position of the main valve core 200 can be changed following the position of the pilot valve core 300 , that is, the main valve core 200 moves following the pilot valve core 300 .

[0042] For example, the driving device 600 drives the pilot valve core 300 to move to the left by a set distance. When the second through hole 310 of the pilot valve core 300 is connected to the first through hole 220, the pressure relief channel 210 is connected to the control segment 130 on the left side of the main valve core 200. At this time, the liquid in the control segment 130 on the left side of the main valve core 200 is connected to the return liquid port 161 through the first through hole 220, the second through hole 310 and the pressure relief channel 210. The pressure in the control segment 130 on the left side of the main valve core 200 is reduced, and at this time, the pipeline 500 will continuously transport high-pressure liquid to the control segment 130 on the left side of the main valve core 200 through the first channel 131.

[0043] However, a throttle valve 800 is connected in series in the pipeline connecting the pipeline 500 and the first channel 131. Since the throttle valve 800 has a certain pressure drop effect, the greater the flow rate, the greater the pressure drop. At the same time, the pressure in the control segment 130 on the right side of the main valve core 200 is always equal to the system pressure. Therefore, when the pressure in the control segment 130 on the left side of the main valve core 200 drops to a certain value, due to the pressure difference on both sides, the liquid will drive the main valve core 200 to move to the left until the second through hole 310 of the pilot valve core 300 is forced to disconnect from the first through hole 220, and the movement of the main valve core 200 stops. At this point, the main valve core 200 has completed the process of following the movement of the pilot valve core 300. In addition, the liquid inlet 141 is connected to the liquid outlet 151 to maintain a specific opening. If the opening between the liquid inlet 141 and the liquid outlet 151 is increased to increase the flow rate, the control drive device 600 drives the pilot valve core 300 to move a certain distance to the left again, and the main valve core 200 will follow. Repeating the above steps can complete the opening action of the main valve core 200.

[0044] Thus, by controlling the displacement of the pilot valve core 300 through the driving device 600, the displacement of the main valve core 200 can be controlled, thereby realizing precise and continuous control of the opening of the main valve core 200. This not only avoids the installation of a valve core displacement sensor, but also greatly simplifies the overall structure of the pilot proportional valve, making the processing and manufacturing of the pilot proportional valve easier and more cost-effective.

[0045] Furthermore, the effective intercepting area of ​​the second through hole 310 is larger than the effective throttling area of ​​the throttle valve 800 , so that the discharge capacity of the pilot valve core 300 is larger than the intake capacity of the throttle valve 800 .

[0046] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0047] In order to make the main valve core 200 have consistent starting characteristics during the control process, the main valve core 200 is designed to be balanced. Specifically, the pressure relief channel 210 is provided with a balancing groove 211 extending along the circumference of its side wall. The first through hole 220 extends from the bottom surface of the balancing groove 211 to the control segment 130.

[0048] When the end of the pilot valve core 300 moves to the right side of the balancing groove 211, the balancing groove 211 forms an annular cavity around the pilot valve core 300. In this way, when the pilot valve core 300 is controlled to slide in the pressure relief channel 210, there is a certain buffer space between the second through hole 310 of the pilot valve core 300 and the first through hole 220, which avoids the second through hole 310 and the first through hole 220 from generating violent fluctuations in the instant of opening and closing, thereby improving the reliability and stability of the pilot proportional valve.

[0049] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0050] The main valve core 200 is provided with a control portion 240 sliding in the control segment 130. The valve sleeve 100 is provided with a pipeline 500 connecting the first hole 131 and the liquid inlet 141 outside, which is used to transport liquid into the control segment 130 to drive the main valve core 200 to move.

[0051] When the liquid flow rate entering the control segment 130 through the first hole 131 is greater than the liquid flow rate discharged from the control segment 130 through the second through hole 310 , the main valve core 200 moves to the right.

[0052] Alternatively, when the liquid flow rate entering the control segment 130 through the first hole 131 is less than the liquid flow rate discharged from the control segment 130 through the second through hole 310 , the main valve core 200 moves to the left.

[0053] The first hole 131 is connected from the outside of the valve sleeve 100 to the left side of the control section 130. The second hole 142 is connected from the liquid inlet 141 to the right side of the control section 130. The pipeline 500 is connected with the first hole 131 and the second hole 142.

[0054] like Figure 1 As shown, when the pilot follower proportional valve is in the initial state, the reversing valve 700 is not energized, the high pressure liquid is disconnected from the third channel 162, and the liquid return valve core 400 is located at the right end of the liquid return segment 160, and the liquid outlet is connected to the liquid return port.

[0055] like Figure 2 As shown, the reversing valve 700 is energized, the high pressure liquid is connected to the third channel 162, and under the action of the high pressure liquid, the liquid return valve core 400 moves to the left end of the liquid return segment 160, at which time the liquid outlet is disconnected from the liquid return port. While the reversing valve 700 is energized, the driving device 600 drives the pilot valve core 300 to move to the left, and when the pilot valve core 300 moves to the point where the first through hole 220 is about to be connected to the second through hole 310, it is a critical state.

[0056] In the critical state, the pilot valve core 300 continues to move to the left, and the control segment 130 is connected to the second through hole 310, the pressure in the control segment 130 decreases, the force balance is broken, and under the action of the unbalanced force, the main valve core 200 starts to move to the left.

[0057] like Figure 4 As shown in FIG. 1 , it is assumed that the pilot valve core 300 remains unchanged after moving to a certain position, and as the main valve core 200 follows the movement, when the main valve core 200 moves to Figure 4When the pilot valve core 300 is in the position shown, the second through hole 310 on the pilot valve core 300 is in a semi-open and semi-closed state, and the main valve core 200 is rebalanced and keeps the position unchanged. In this balanced working state, as long as the pilot valve core 300 moves to the left, the force balance on the left and right sides of the control part 240 of the main valve core 200 will be broken, and the main valve core 200 will move to the left with the pilot valve core 300 until it moves to the semi-open and semi-closed state again, and then it is balanced again.

[0058] Similarly, in this balanced working state, as long as the pilot valve core 300 moves to the right, the force balance on the left and right sides of the main valve core 200 control part will be broken, and the pressure on the left side of the main valve core 200 control part will increase, driving the main valve core 200 to move to the right until it moves again to the second through hole 310 on the pilot valve core 300 in a semi-open and semi-closed state, and then it is balanced again.

[0059] When the pilot valve core 300 keeps moving to the right, the main valve port is continuously closed. When the main valve core 200 just contacts and closes the valve sleeve, the second through hole 310 on the pilot valve core 300 is still in a half-open and half-closed equilibrium state. In order to reliably seal the main valve port, the pilot valve core 300 needs to continue to move to the right until the control segment 130 is disconnected from the second through hole 310. At this time, the pressure on the left side of the control part 240 of the main valve core 200 will increase, ensuring that the main valve core 200 is tightly sealed on the conical surface of the valve sleeve 100.

[0060] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0061] The right end of the chamber 110 is provided with a liquid return section 160 having a liquid return port 161. The valve sleeve 100 is provided with a cylindrical portion 170 in the liquid return section 160. There is an annular gap between the cylindrical portion 170 and the inner wall of the liquid return section 160. The right end of the main valve core 200 is slidably inserted in the cylindrical portion 170.

[0062] Furthermore, the pilot follower proportional valve further comprises a liquid return valve core 400 slidably sleeved outside the cylindrical portion 170. The liquid return valve core 400 moves between an open position connecting the liquid outlet segment 150 and the liquid return segment 160 and a closed position isolating the liquid outlet segment 150 and the liquid return segment 160.

[0063] A third channel 162 is provided on the right side of the liquid return segment 160 for conveying liquid into the annular space between the cylindrical portion 170 and the liquid return segment 160 to drive the liquid return valve core 400 to move.

[0064] A reversing valve 700 is provided between the third hole 162 and the liquid return port 161 , and is used to control whether the third hole 162 is in communication with the liquid return port 161 or with the pipeline 500 .

[0065] Specifically, the reversing valve 700 is configured as an electromagnetic switch valve. Figure 1 In the de-energized position shown, the third channel 162 on the right side of the liquid return valve core 400 is in a connected state with the liquid return port 161 through the electromagnetic switch valve. At this time, the liquid outlet 151 and the liquid return port 161 are connected. In addition, the pilot follower proportional valve in the present invention is a two-position three-way structure. It is provided with three working interfaces, namely: the liquid inlet P, the liquid outlet A and the liquid return port R. The initial state is: the liquid inlet 141 is disconnected from the liquid outlet 151, and the liquid outlet 151 is connected to the liquid return port 161.

[0066] The liquid outlet 151 is usually connected to the working chamber of the hydraulic cylinder. When the hydraulic cylinder needs to extend, the liquid inlet 141 needs to be connected to the liquid outlet 151, and the liquid outlet 151 is disconnected from the liquid return port 161.

[0067] At this time, the working process of the pilot follower proportional valve is as follows: first, the liquid return valve core 400 is closed, that is, the electromagnetic switch valve is energized, and the high-pressure liquid in the pipeline 500 enters the right side of the liquid return valve core 400 through the electromagnetic switch valve and the third channel 162, pushing the liquid return valve core 400 to move leftward to disconnect the connection between the liquid outlet segment 150 and the liquid return segment 160. That is, the liquid outlet 151 and the liquid return port 161 are separated.

[0068] Then, the driving device 600 drives the pilot valve core 300 to move to the left by a set distance. When the second through hole 310 of the pilot valve core 300 is connected to the first through hole 220, the pressure relief channel 210 is connected to the control segment 130 on the left side of the main valve core 200. At this time, the liquid in the control segment 130 on the left side of the main valve core 200 is connected to the return liquid port 161 through the first through hole 220, the second through hole 310 and the pressure relief channel 210. The pressure in the control segment 130 on the left side of the main valve core 200 is reduced, and at this time, the pipeline 500 will continuously transport high-pressure liquid to the control segment 130 on the left side of the main valve core 200 through the first channel 131.

[0069] However, a throttle valve 800 is connected in series in the pipeline connecting the pipeline 500 and the first channel 131. Since the throttle valve 800 has a certain pressure drop effect, the greater the flow rate, the greater the pressure drop. At the same time, the pressure in the control segment 130 on the right side of the main valve core 200 is always equal to the system pressure. Therefore, when the pressure in the control segment 130 on the left side of the main valve core 200 drops to a certain value, due to the pressure difference on both sides, the liquid will drive the main valve core 200 to move to the left until the second through hole 310 of the pilot valve core 300 is forced to disconnect from the first through hole 220, and the movement of the main valve core 200 stops. At this point, the main valve core 200 has completed the process of following the movement of the pilot valve core 300. In addition, the liquid inlet 141 is connected to the liquid outlet 151 to maintain a specific opening. If the opening between the liquid inlet 141 and the liquid outlet 151 is increased to increase the flow rate, the control drive device 600 drives the pilot valve core 300 to move a certain distance to the left again, and the main valve core 200 will follow. Repeating the above steps can complete the opening action of the main valve core 200.

[0070] In this embodiment, the control of the main valve core 200 and the liquid return valve core 400 are separated and controlled by a driving device 600 and a two-position three-way electromagnetic switch valve respectively, which ensures the reliability of the structure and realizes the precise control of the position of the main valve core 200. Moreover, the movement control of the main valve core 200 can be realized by controlling the pressure of the control segment 130 provided at the left end of the pilot proportional valve, which greatly simplifies the structure of the valve sleeve 100 and reduces the processing difficulty and cost of the pilot proportional valve.

[0071] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0072] In order to improve the sealing performance between the relative motion surfaces of the pilot valve core 300 and the main valve core 200, a sealing member 212 is further provided on the side wall of the pressure relief channel 210. The two sealing members 212 are respectively located on the left and right sides of the balance groove 211.

[0073] Further, the cavity 110 is provided with a guide segment 120. The guide segment 120 is located on the left side of the control segment 130. The cross-sectional diameter of the guide segment 120 is smaller than the cross-sectional diameter of the control segment 130. The first channel 131 is located adjacent to the guide segment 120 and the control segment 130.

[0074] The left end of the main valve core 200 is configured as a guide portion 230 that cooperates with the guide segment 120 . The guide portion 230 is slidably plugged into the guide segment 120 .

[0075] In this embodiment, the pilot valve core 300 is set to a sliding valve plus a sealing structure, which is suitable for hydraulic systems of water-based media, such as underground coal mine applications, and can also be applied to oil-based hydraulic products. At the same time, it can also reduce the friction between the pilot valve core 300 and the main valve core 200, and further reduce the driving power required by the driving device 600.

[0076] Based on the above embodiment, in another embodiment of the present invention, a pilot follower proportional valve is introduced.

[0077] The parameters associated with the opening of the main valve core 200 and the displacement of the pilot valve core 300 are set. The control pipeline 500 delivers high-pressure liquid to the control segment 130. The pilot valve core 300 is driven to move to the left by a set distance. The above movement process is repeated until the main valve core 200 reaches a preset opening.

[0078] Specifically, first, the correlation parameters between the opening of the main valve core 200 and the displacement of the pilot valve core 300 are preset to obtain a linear relationship in which the opening of the main valve core 200 and the displacement of the pilot valve core 300 are positively correlated.

[0079] Then, high-pressure liquid is supplied to the pilot proportional valve through the pipeline 500, and the driving device 600 is controlled to drive the pilot valve core 300 to move according to the set distance. The specific steps are: close the liquid return valve core 400, and the high-pressure liquid in the pipeline 500 enters the right side of the liquid return valve core 400 through the electromagnetic switch valve and the third channel 162, pushing the liquid return valve core 400 to move to the left to disconnect the connection between the liquid outlet segment 150 and the liquid return segment 160; the driving device 600 drives the pilot valve core 300 to move to the left by the set distance, and the liquid drives the main valve core 200 to move to the left to complete the process of following the movement of the pilot valve core 300.

[0080] Finally, if the opening between the liquid inlet 141 and the liquid outlet 151 is increased, the control driving device 600 drives the pilot valve core 300 to move a certain distance to the left again, and the main valve core 200 moves with the pilot valve core 300. Repeat this step until the set opening is reached.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A pilot follower proportional valve, characterized in that: include: A valve sleeve (100), the valve sleeve (100) being provided with a cavity (110) extending through both ends thereof along its axis, the cavity (110) comprising a control segment (130), a liquid inlet segment (140) and a liquid outlet segment (150), the liquid inlet segment (140) and the liquid outlet segment (150) being provided with a liquid inlet (141) and a liquid outlet (151), respectively; A main valve core (200) moves between an open position connecting the liquid inlet segment (140) and the liquid outlet segment (150) and a closed position separating the liquid inlet segment (140) and the liquid outlet segment (150), and the main valve core (200) is provided with a pressure relief channel (210) extending along its axis; The valve sleeve (100) is provided with a first channel (131) and a second channel (142) which are connected to the control section (130) to drive the main valve core (200) to move; the main valve core (200) is provided with a first through hole (220) which is radially connected to the pressure relief channel (210) and the control section (130); the pressure relief channel (210) is provided with a pilot valve core (300) which moves along its axial direction and is used to control the on-off state of the first through hole (220) and the pressure relief channel (210).

2. The pilot follower proportional valve according to claim 1, characterized in that: It also includes a driving device (600), connected to the pilot valve core (300) and fixed at the left end of the chamber (110), and used for driving the pilot valve core (300) to move relative to the pressure relief channel (210); The pilot valve core (300) is provided with a second through hole (310) extending from its end surface to its side wall, and the second through hole (310) is located on the right side of the first through hole (220) and is used to enable the pilot valve core (300) to have an initial position that separates the first through hole (220) from the pressure relief channel (210).

3. The pilot follower proportional valve according to claim 2, characterized in that: The pressure relief channel (210) is provided with a balancing groove (211) extending in the circumferential direction of its side wall, and the first through hole (220) extends from the bottom surface of the balancing groove (211) to the control segment (130); When the end of the pilot valve core (300) moves to the right side of the balancing groove (211), the balancing groove (211) forms an annular cavity around the pilot valve core (300).

4. The pilot follower proportional valve according to any one of claims 1 to 3, characterized in that: The main valve core (200) is provided with a control portion (240) sliding in the control segment (130); the valve sleeve (100) is provided with a pipeline (500) outside thereof connecting the first hole (131) and the liquid inlet (141) for conveying liquid into the control segment (130) to drive the main valve core (200) to move; When the flow rate of liquid entering the control section (130) through the first hole (131) is greater than the flow rate of liquid discharged from the control section (130) through the second through hole (310), the main valve core (200) moves to the right; or, when the flow rate of liquid entering the control section (130) through the first hole (131) is less than the flow rate of liquid discharged from the control section (130) through the second through hole (310), the main valve core (200) moves to the left; The first hole (131) is connected from the outside of the valve sleeve (100) to the left side of the control section (130), the second hole (142) is connected from the liquid inlet (141) to the right side of the control section (130), and the pipeline (500) is connected to the first hole (131) and the second hole (142).

5. The pilot follower proportional valve according to claim 4, characterized in that: A liquid return segment (160) having a liquid return port (161) is also provided at the right end of the chamber (110); a cylindrical portion (170) is provided on the valve sleeve (100) in the liquid return segment (160); an annular gap is provided between the cylindrical portion (170) and the inner wall of the liquid return segment (160); and the right end of the main valve core (200) is slidably inserted in the cylindrical portion (170).

6. The pilot follower proportional valve according to claim 5, characterized in that: It also includes a liquid return valve core (400) slidably sleeved on the outside of the cylindrical portion (170), the liquid return valve core (400) moving between an open position connecting the liquid outlet segment (150) and the liquid return segment (160) and a closed position separating the liquid outlet segment (150) and the liquid return segment (160).

7. The pilot follower proportional valve according to claim 6, characterized in that: A third hole (162) is provided on the right side of the liquid return segment (160) for conveying liquid into the annular space between the cylindrical portion (170) and the liquid return segment (160) to drive the liquid return valve core (400) to move; A reversing valve (700) is provided between the third hole (162) and the liquid return port (161), for controlling whether the third hole (162) is in communication with the liquid return port (161) or with the pipeline (500).

8. The pilot follower proportional valve according to claim 3, characterized in that: A sealing member (212) is also provided on the side wall of the pressure relief channel (210), and the two sealing members (212) are respectively located on the left and right sides of the balancing groove (211).

9. The pilot follower proportional valve according to claim 4, characterized in that: The cavity (110) is provided with a guide segment (120), the guide segment (120) is located on the left side of the control segment (130), the cross-sectional diameter of the guide segment (120) is smaller than the cross-sectional diameter of the control segment (130), and the first channel (131) is located adjacent to the guide segment (120) and the control segment (130); The left end of the main valve core (200) is arranged as a guide portion (230) that cooperates with the guide segment (120), and the guide portion (230) is slidably plugged into the guide segment (120).

10. The pilot follower proportional valve according to claim 9, characterized in that: The pipeline (500) is controlled to deliver high-pressure liquid to the control section (130), driving the pilot valve core (300) to move to the left by a set distance, and the above-mentioned movement process is repeated until the main valve core (200) reaches a preset opening.

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