A pilot valve structure

Abstract

The present invention provides a pilot valve structure, comprising a pilot valve part (200) and an electromagnetic valve part (300) for controlling the working state of the pilot valve part (200). Since a piston assembly with a reset function is used in a three-position electromagnetic slide valve, the functions of a traditional piston and a return spring are integrated in the piston assembly. Only the piston assembly and the pilot flow path are used to switch the three slide valve core positions of the traditional three-position valve. Moreover, the pilot structure of this embodiment has no significant difference in size from the traditional pilot structure, so the size of the slide valve in the length direction is greatly reduced. The beneficial effects of the specific implementation means are shown in the embodiment section.

Description

Technical Field

[0001] The present invention relates to a slide valve which uses a valve core sliding in a valve hole to open and close flow paths between a plurality of ports, and in particular to a pilot valve structure. Background Art

[0002] The known three-position switching valve is constructed in the following manner, that is, pistons are respectively arranged at both ends of the sliding valve core which is freely slidably accommodated in the valve hole, and the spring force of the return spring acts on the sliding valve. If the pilot fluid pressure acts on the piston of one side through the pilot valve on one side, the sliding valve moves in one direction and switches to the first switching position. If the pilot fluid pressure acts on the piston of the other side through the pilot valve on the other side, the sliding valve moves in the opposite direction and switches to the second switching position. If the pilot valves on both sides are closed and the pistons on both sides are released from the action of the pilot fluid pressure, the sliding valve is switched to the neutral switching position by the return spring. Sometimes, there are two return springs, which are respectively placed at the two ends of the sliding valve core, and sometimes there is only one return spring, which can also switch the sliding valve core to the neutral switching position. For example, CN205101602U three-position five-way center-sealed solenoid valve, CN204061998U normally closed three-position five-way solenoid valve, but the return spring is indispensable, and a separate installation cavity is required to install the return spring.

[0003] The above-mentioned three-position switching valves all have a defect that the piston and return spring arranged along the length direction of the switching valve body make it difficult to reduce the length of the switching valve. In particular, when the installation space is limited, the three-position switching valve is difficult to install in the space due to its excessive length. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a pilot valve structure, which has the functions of a traditional piston and a return spring. It is used to replace the traditional structure to reduce the length of the valve body and eliminate the defects in the prior art.

[0005] A pilot valve structure includes a pilot valve part and a solenoid valve part for controlling the working state of the pilot valve part, wherein the pilot valve part includes:

[0006] A pilot valve cover, wherein the second joint surface in the pilot valve cover divides the pilot valve cover into a piston chamber and a pilot component installation chamber, wherein the piston assembly is installed in the piston chamber to push the spool of the sliding valve of the main valve body; the pilot component is installed in the pilot component installation chamber and includes a pilot chamber;

[0007] The piston assembly comprises a first shell and a second shell and an inner cavity surrounded by the first shell and the second shell. The elastic part is arranged in the inner cavity and can be compressed by the first shell and / or the second shell and rebound after the pressure is released. The first shell is covered with a sealing ring.

[0008] It also includes a pilot flow path, which is used to sequentially connect the pilot flow channel of the main valve body, the pilot cavity of the pilot member and the piston cavity of the pilot valve cover. The pilot flow path is confined inside the pilot valve cover and is at least partially formed by the second joint surface inside the pilot valve cover and the first joint surface of the pilot member.

[0009] At least one positioning column is arranged on the second joint surface in the pilot valve cover, and a positioning sleeve is arranged on the outer surface of the pilot component. The positioning column can be inserted into the positioning sleeve to relatively position the pilot valve cover and the pilot component.

[0010] The pilot piece has a plurality of positioning sleeves which are evenly distributed on the outer surface of the pilot piece, and a plurality of positioning posts are arranged in the pilot valve cover to adapt to the positioning sleeves.

[0011] The second joint surface in the pilot valve cover and / or the first joint surface of the pilot member are provided with an arc structure for facilitating the passage of fluid, and the arc structure is formed in the pilot flow path.

[0012] The piston assembly can be compressed by the spool valve core against the piston chamber side wall, can reset the spool valve core to a neutral switching position when the pilot fluid pressure does not act on it, and can push the spool valve core under the action of the pilot fluid pressure.

[0013] A top column is provided on the outer surface of the first shell, and the top column can at least partially enter into the valve hole of the main valve body portion adjacent to the pilot valve portion and push the valve core of the sliding valve.

[0014] The second shell is at least partially located in the first shell and is guided and limited by the first shell. A fixing column is provided on the inner wall of the first shell, and a positioning seat is provided on the inner wall of the second shell. The elastic part includes a first spring, and both ends of the first spring are positioned by the fixing column and the positioning seat respectively.

[0015] The elastic part also includes a second spring. Two ends of the second spring are respectively positioned by the fixing column and the positioning seat and are sleeved on the outside of the first spring. The second spring has a greater elastic force than the first spring.

[0016] The first shell and / or the second shell is provided with a vent hole, and the fluid in the inner cavity can be discharged from the vent hole when the piston assembly is compressed.

[0017] Beneficial effects of the invention:

[0018] The present invention uses a piston assembly with a reset function in the pilot valve structure of the three-position electromagnetic slide valve, integrates the functions of the traditional piston and the return spring on the piston assembly, and can realize the switching of the three slide valve core positions of the traditional three-position valve only by the cooperation of the piston assembly and the pilot flow path, and the pilot structure of this embodiment has no obvious change in size from the traditional pilot structure, so the size of the slide valve is greatly reduced in the length direction. The beneficial effects of the specific implementation means are shown in the embodiment part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be 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 labor.

[0020] Figure 1 is a cross-sectional view of a double pilot type slide valve of the present invention;

[0021] Figure 2 The present invention Figure 1 A side view of a main valve body;

[0022] Figure 3 is an exploded view of a piston assembly of the present invention;

[0023] Figure 4 is a cross-sectional view of a piston assembly of the present invention;

[0024] Figure 5 is a three-dimensional view of the pilot valve structure of the present invention;

[0025] Figure 6 It is an exploded view of the pilot valve cover and the pilot member of the present invention;

[0026] Figure 7 is a three-dimensional view of the pilot valve structure of the present invention from another perspective;

[0027] Figure 8 is a three-dimensional view of the pilot member of the present invention;

[0028] Fig. 9 is a side view of the pilot member of the present invention;

[0029] Fig.10 is a longitudinal sectional view of the pilot valve structure of the present invention after the piston assembly is removed;

[0030] Fig.11 is a side view of the pilot valve cover of the present invention;

[0031] Fig.12 is a longitudinal sectional view of a pilot valve cover of the present invention;

[0032] Fig.13 It is a horizontal cross-sectional view of the pilot valve cover of the present invention.

[0033] Description of main reference numerals:

[0034] 100-main valve body, 11-pilot flow channel, 12-main valve body sealing ring, 13-valve core first end, 14-valve core second end, 15-screw hole, 16-valve core, 200-pilot valve part, 21-pilot valve cover, 210-first inlet, 211-second inlet, 212-second joint surface, 213-second side wall, 214-second pilot hole, 215-sealing ring, 216-rib plate, 217-positioning column, 22-pilot part, 220-positioning sleeve, 221-first pilot hole, 222-first joint surface, 223-sealing groove, 224-first side wall, 225-pilot cavity, 226-valve seat, 227-limiting plate, 23-manual valve, 230-manual valve O-ring, 231-manual valve spring, 232-top , 24-piston assembly, 240-piston chamber, 241-first shell, 2411-fixed column, 2412-guide cylinder, 2413-sunk groove, 2414-positioning flange, 2415-top column, 242-second shell, 243-vent, 244-limiting flange, 245-first spring, 246-sealing ring, 247-positioning seat, 248-deformation groove, 249-second spring, 25-cover plate, 250-plate body, 251-limiting angle, 300-solenoid valve part, 301-jacket, 302-iron core, 303-first sealing ring, 304-solenoid valve core, 305-second sealing ring, 306-inner valve core, 307-inner sleeve, 308-second return spring, 309-external thread, 310-first return spring. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of 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.

[0036] Refer to the following Figures 1 to 13 Dual pilot operated spool valves according to some embodiments of the present invention are described.

[0037] Figure 1A double pilot slide valve in this embodiment is provided. The slide valve is a double-side pilot slide valve with a pilot valve part 200, and has a main valve body 100 and pilot valve parts 200 on both sides. In this embodiment, the main valve body 100 has a valve structure as a five-port valve, which is a three-position five-way valve. The pilot valve part 200 is arranged at both ends of the length direction of the main valve body 100. The pressure fluid controlled by the main valve body 100 is compressed air. It should be clarified that the pilot valve part 200 of this embodiment does not need to be matched with the main valve body 100 with a specific number of ports, and the main valve body 100 of the three-position five-way valve in this embodiment should not be understood as a limitation on the pilot valve part 200.

[0038] The housing of the main valve body 100 is a rectangular block having length, width and height directions, and input ports P and discharge ports E1 and E2 are arranged on the lower surface along the length direction of the housing. Output ports A1 and A2 are provided on the upper surface, and the five ports are arranged as follows: the first and second output ports A1 and A2 are located on both sides of the central input port P, and the first and second discharge ports E1 and E2 are located on both outsides of the first and second output ports A1 and A2.

[0039] By alternately connecting and disconnecting the two pilot valve parts 200 to alternately supply or discharge pilot gas, the slide valve core 16 is switched to the advancing position or the restoring position. When there is no fluid supply to the input port P of the main valve body 100, the slide valve core 16 is located in the middle position, that is, the cut-off position. At this time, the five ports of input port P, discharge ports E1 and E2, and output ports A1 and A2 on the upper surface are all cut off by the slide valve core 16. The on-off coordination of the slide valve core in the housing of the main valve body 100 and each port is not the focus of the present invention. It is a prior art and will not be described in detail here.

[0040] The pilot valve portion 200 on one side causes the propulsion force in one direction generated by the pilot gas to act on the slide valve core 16, and the pilot valve portion 200' on the other side acts on the second end 14 of the slide valve core 16, thereby providing power for the pilot valve portion 200 on one side to move toward the side.

[0041] The pilot valve unit 200 includes a pilot valve housing 21 connected to the housing and a driving structure of the solenoid valve unit 300 connected to the pilot valve housing 21. A piston chamber 240 leading to the end of the valve hole is formed inside the pilot valve housing 21, and a pilot piston 24 that causes a propulsive force to act on the spool valve core 16 is accommodated inside the piston chamber 240 so as to slide freely along the axial direction of the spool valve core.

[0042] A piston seal 246 is installed on the outer periphery of the piston 24 for sealing the outer periphery of the piston 24 and the inner periphery of the piston chamber 240. The piston chamber 240 is divided into a pressure chamber for propulsion by using the piston 24 and the piston seal 246 thereon. The pressure chamber for propulsion is supplied with pilot gas from the pilot flow path from the input port P or the pilot gas is discharged from the input port P.

[0043] The present embodiment provides a dual pilot slide valve, comprising: a main valve body 100, having ports for input, output and discharge, a valve hole formed in the main valve body 100 in a manner connected to the above-mentioned ports; a slide valve core 16, which is freely slidable in the axial direction and is accommodated in the valve hole, and has three switching positions: a first switching position moving toward one end side of the valve hole, a second switching position moving toward the other end side, and a neutral switching position, wherein the neutral switching position is a switching position between the above-mentioned first switching position and the second switching position; the slide valve core can also be selected Selectively open or close the input, output and discharge ports; a first piston and a second piston are arranged at one end and the other end of the sliding valve core 16, and receive the action of the pilot fluid pressure to switch the sliding valve core 16 to the above-mentioned first switching position and second switching position. The first piston and / or the second piston are piston assemblies including elastic parts, which can be compressed by the sliding valve core 16, can reset the sliding valve core 16 to the neutral switching position when the pilot fluid pressure does not act on the above-mentioned first piston and second piston, and can push the sliding valve core 16 under the action of the pilot fluid pressure.

[0044] Because a piston assembly with a reset function is used, the functions of the traditional piston and return spring are integrated into the piston assembly, so that the return spring and its installation cavity of the traditional three-position valve can be removed, and only the pilot structure is retained. Moreover, there is no obvious change in size between the pilot structure of this embodiment and the traditional pilot structure, so the size of the sliding valve is greatly reduced in the length direction.

[0045] The piston assembly 24 includes a first shell 241 and a second shell 242 and an inner cavity surrounded by the first shell 241 and the second shell 242. The elastic part is placed in the inner cavity and can be compressed by the first shell 241 and / or the second shell 242 and rebound after the pressure is released. The first shell 241 is covered with a sealing ring 246. That is, in this embodiment, the traditional return spring is creatively integrated into the piston assembly, and is embedded between the first shell and the second shell of the piston assembly in the form of an elastic part, so as to provide elastic force.

[0046] A top column 2415 is provided on the outer surface of the first shell 241. The top column 2415 can at least partially enter the valve hole of the main valve body 100 and push the slide valve core 16. When the piston assembly is pushed toward the slide valve core by the pilot fluid pressure, the top column 2415 extends into the valve hole to push the slide valve core 16 to the other side and compress the piston assembly or other reset device on the other side. At this time, the slide valve core 16 switches to the first switching position or the second switching position.

[0047] A fixing column 2411 is provided on the inner wall of the first shell 241, a positioning seat 247 is provided on the inner wall of the second shell 242, and the elastic part includes a first spring 245, and both ends of the first spring 245 are positioned by the fixing column 2411 and the positioning seat 247. The first spring 245 is a hollow spirally wound cylindrical shape, and the fixing column 2411 and the positioning seat 247 are both extended into the hollow space, which can prevent the first spring 245 from being displaced or deviating from the working position.

[0048] The elastic part also includes a second spring 249, the two ends of which are respectively positioned by the fixing column 2411 and the positioning seat 247 and are sleeved on the outside of the first spring 245. The second spring 249 has a greater elastic force than the first spring 245. Firstly, since the inner cavity space formed by the first shell 241 and the second shell 242 is limited, the length of the spring installed therein is also limited, and the spring restoring force provided by it may not meet the requirements, so two springs are used to provide restoring elastic force at the same time; secondly, the second spring 249 with large elastic force is sleeved on the outside of the first spring 245, so that the first shell 241 and the second shell 242 can be more evenly stressed.

[0049] The first shell 241 and / or the second shell 242 are provided with a vent hole 243, and the fluid in the inner cavity can be discharged from the vent hole 243 when the piston assembly 24 is compressed. Preferably, the vent hole 243 is located on the second shell 242 and penetrates the positioning seat 247. In this way, the fluid can enter or flow out of the inner cavity axially, and the piston assembly will not be subjected to forces other than the axial force, thereby preventing the piston assembly from being stuck in the piston cavity.

[0050] The first pilot valve part and the second pilot valve part are respectively provided on both sides of the main valve body 100. The first pilot valve part and the second pilot valve part use the propulsion force generated by the pilot fluid pressure provided by the input port to act on the first piston and the second piston in the piston cavity thereof. When the pilot fluid pressure does not act on the piston assembly 24, the first shell 241 is pressed against one end of the slide valve core 16 by the elastic part, and the second shell 242 is pressed against the side wall of the piston cavity 240 by the elastic part. The slide valve core 16 is equal in length to the valve hole. When the pilot fluid pressure does not act on the first piston and the second piston, the slide valve core 16 is kept in the valve hole and is in a neutral switching position. When the sliding valve core 16 is pushed, its axial displacement is limited by the length of the top column 2415 extending into the valve hole. In this embodiment, the plane of the first shell 241 surrounding the top column 2415 will serve as a positioning surface limit and abut against the end face of the main valve body 100 when the sliding valve core 16 is pushed, thereby accurately determining the length of the top column 2415 extending into the valve hole.

[0051] The first shell 241 includes a guide cylinder 2412, and a positioning flange 2414 is provided at the end of the guide cylinder 2412. The second shell 242 includes a limiting flange 244, and the positioning flange 2414 cooperates with the limiting flange 244 to prevent the first shell 241 from being separated from the second shell 242. The second shell 242 is provided with at least one deformation groove 248, and the second shell 242 can enter the guide cylinder 2412 of the first shell 241 in a state where the deformation groove 248 is contracted. When the second shell 242 enters the guide cylinder 2412, the compression of the deformation groove 248 can be released, and the second shell 242 stretches in the guide cylinder 2412 to a state where no force is applied, and the second shell is guided by the inner wall of the guide cylinder to move in the axial direction.

[0052] In this embodiment, the pilot valve part 200 and the solenoid valve part 300 for controlling the working state of the pilot valve part 200, the pilot valve part 200 includes: a pilot valve cover 21, the second joint surface 212 in the pilot valve cover 21 divides the pilot valve cover 21 into a piston chamber 240 and a pilot member installation chamber, the piston 24 is installed in the piston chamber 240 for pushing the spool 16 of the main valve body 100. The pilot member 22 is installed in the pilot member installation chamber and includes a pilot chamber 225. The pilot flow path is used to sequentially connect the pilot flow channel 11 of the main valve body 100, the pilot chamber 225 of the pilot member 22 and the piston chamber 240 of the pilot valve cover 21, the pilot flow path is defined inside the pilot valve cover 21 and is at least partially formed by being surrounded by the second joint surface 212 in the pilot valve cover and the first joint surface 222 of the pilot member 22.

[0053] The applicant has previously tried to divide the pilot structure and the electromagnet module into two independent components and process them separately before assembling them together. That is, the pilot cavity is a part of the electromagnet module and is parallel to the pilot structure, and the pilot flow path is formed between the pilot structure and the electromagnet module. However, in actual processing, it was found that this technology has great defects and its assembly is inconvenient. Although the assembly of the two also eliminates the problem of the need to drill process holes in the pilot structure, the assembly accuracy of both the pilot structure and the electromagnet module needs to be greatly improved, and the cost is also greatly increased. Therefore, in this embodiment, the second joint surface 212 in the pilot valve cover 21 divides the pilot valve cover 21 into a piston chamber 240 and a pilot installation chamber. The applicant integrates the pilot chamber of the electromagnetic module for fluid on-off control into the pilot structure. This integration greatly improves the matching accuracy between the pilot structure and the pilot containing the pilot chamber. For example, when the pilot 22 is installed, it can be guided by at least one inner wall of the pilot installation chamber of the pilot valve cover 21. After the pilot 22 initially enters the pilot installation chamber, it can also be combined with other positioning guide structures to improve assembly accuracy. It can also make the pilot use the space of the pilot structure more reasonably and make the layout more compact, thereby reducing the overall length of the pilot valve.

[0054] Furthermore, the pilot valve housing 21 is provided with a first inlet 210 , and a second side wall 213 is provided on the second joint surface 212 . The first inlet 210 and the second side wall 213 are communicated with each other at the second inlet 211 and become a part of the pilot flow path.

[0055] The pilot member 22 is provided with a first side wall 224 on the first joint surface 222 , and a valve seat 226 is provided in the pilot cavity 225 . The first side wall 224 is connected to the pilot cavity 225 through the valve seat 226 and becomes a part of the pilot flow path.

[0056] A second pilot hole 214 is provided on the second joint surface 212 of the pilot valve cover 21, and a first pilot hole 221 is provided on the first joint surface 222 of the pilot member 22. The pilot cavity 225 is connected with the piston cavity 240 through the first pilot hole and the second pilot hole. A sealing ring 215 is provided on the second joint surface 212 and / or the first joint surface 222 for sealing the fluid passage defined by the second side wall 213 of the pilot valve cover 21 and the first side wall 224 of the pilot member 22 and the fluid passage formed by the first pilot hole and the second pilot hole.

[0057] At least one positioning column 217 is provided on the second joint surface in the pilot valve cover 21 , and a positioning sleeve 220 is provided on the outer surface of the pilot member 22 . The positioning column 217 can be inserted into the positioning sleeve 220 to relatively position the pilot valve cover 21 and the pilot member 22 .

[0058] There are multiple positioning sleeves 220 of the pilot member 22 that are evenly distributed on the outer surface of the pilot member 22 . A plurality of positioning posts 217 are arranged in the pilot valve cover 21 to adapt to the positioning sleeves 220 .

[0059] The pilot valve part 200 is also provided with a manual valve 23 for manually opening the valve seat 226. The valve stem of the manual valve 23 passes through the pilot valve cover 21 and the pilot part 22, and the top head 232 of the valve stem can cooperate with the solenoid valve core 304 of the solenoid valve part 300 in the pilot chamber 225 to push the solenoid valve core 304 to a position away from the sealing valve seat 226. A manual valve spring 231 is arranged outside the valve stem and is limited by the limit plate 227 located in the pilot part 22 to prevent it from popping out.

[0060] The present embodiment also provides a sliding valve, using the aforementioned pilot valve structure, that is, the sliding valve has a main valve portion 100, a pilot valve structure and an electromagnetic valve portion 300 for controlling the working condition of the pilot valve portion, the main valve portion comprising: a shell, on which are provided ports for input, output and discharge; a valve hole, the valve hole extending along the length direction of the shell inside the shell; and a sliding valve core 16, the sliding valve core 16 can be slidably inserted into the valve hole in the axial direction of the valve hole, and can selectively open or close the input, output and discharge ports; the pilot valve portion 200 causes the propulsion force generated by the pilot fluid provided by the input port to act on the sliding valve core 16.

[0061] The solenoid valve part 300 is used to selectively open or close the valve seat 226 of the pilot valve structure, thereby selectively opening or closing the pilot flow path of the pilot valve structure. The electromagnet (not shown in the figure) can be fixed on the iron core 302 through the external thread 309. When the electromagnet is energized, the solenoid valve core 304 moves toward the iron core 302. The solenoid valve part 300 includes a housing 301, Fig.10 It can be seen that the outer sleeve 301 of the solenoid valve part 300 is fixed to one end of the pilot member 22 by the cover plate 25, the solenoid valve core 304 is movably arranged in one end of the outer sleeve 301, and the iron core 302 is fixedly arranged at the other end, the inner valve core 306 and the first return spring 310 are arranged in the inner cavity of the solenoid valve core 304, the inner valve core 306 is biased toward the valve seat 226 side by the first return spring 310, and a second return spring 308 is arranged between the outer sleeve 301 and the solenoid valve core 304, and the solenoid valve core 304 is biased toward the valve seat 226 side by the second return spring 308. An inner valve core 306 is arranged in the inner cavity of the solenoid valve core 304. When the electromagnet (not shown in the figure) loses power, the solenoid valve core 304 moves toward the valve seat 226 under the action of the second return spring 308. When the inner valve core 306 contacts the valve seat 226, it can buffer and absorb the impact force provided by the second return spring 308 under the action of the first return spring 310, that is, reduce the impact between the inner valve core 306 and the valve seat 226, which can increase the service life of the inner valve core 306.

[0062] Figure 7The figure shows the matching relationship between the cover plate 25 and the pilot valve cover 21. In this embodiment, the cover plate 25 has a plate body 250 and a limiting angle 251 on the corner of the plate body 250. The limiting angle 251 can adapt to the notch at the corresponding position of the pilot valve cover 21 to prevent the operator from installing it incorrectly.

[0063] In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", 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 present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pilot valve structure, comprising a pilot valve part (200) and a solenoid valve part (300) for controlling the working state of the pilot valve part (200), characterized in that: The pilot valve section includes: A pilot valve cover (21), wherein a second joint surface (212) in the pilot valve cover divides the pilot valve cover into a piston chamber (240) and a pilot component installation chamber, wherein a piston assembly (24) is installed in the piston chamber (240) to push a spool valve core (16) of a main valve body (100); a pilot component (22), which is installed in the pilot component installation chamber and includes a pilot chamber (225); The piston assembly (24) comprises a first shell (241) and a second shell (242) and an inner cavity formed by the first shell and the second shell. The elastic part is placed in the inner cavity and can be compressed by the first shell and / or the second shell and rebound after the pressure is released. The first shell is covered with a sealing ring (246). The second shell (242) is at least partially located in the first shell (241) and is guided and limited by the first shell. A fixing column (2411) is provided on the inner wall of the first shell (241), and a positioning seat (247) is provided on the inner wall of the second shell (242). The elastic part includes a first spring (245), and two ends of the first spring (245) are positioned by the fixing column (2411) and the positioning seat (247) respectively. The elastic part also includes a second spring (249), the two ends of which are respectively positioned by a fixing column (2411) and a positioning seat (247) and are sleeved on the outside of the first spring (245), and the second spring has a greater elastic force than the first spring; The first shell (241) includes a guide tube (2412), and a positioning flange (2414) is provided at the end of the guide tube (2412). The second shell (242) includes a limiting flange (244). The positioning flange (2414) cooperates with the limiting flange (244) to prevent the first shell (241) and the second shell (242) from being separated. The second shell (242) is provided with at least one deformation groove (248). The second shell (242) can enter the guide tube (2412) of the first shell (241) in a state where the deformation groove (248) is contracted. When the second shell (242) enters the guide tube (2412), the compression of the deformation groove (248) is released, and the second shell (242) stretches in the guide tube (2412) to a state where no force is applied, and the second shell is guided by the inner wall of the guide tube to move in the axial direction.

2. The pilot valve structure according to claim 1, characterized in that: It also includes a pilot flow path, which is used to sequentially connect the pilot flow channel (11) of the main valve body (100), the pilot chamber (225) of the pilot component (22) and the piston chamber (240) of the pilot valve cover (21); the pilot flow path is defined inside the pilot valve cover (21) and is at least partially surrounded by a second joint surface (212) inside the pilot valve cover and a first joint surface (222) of the pilot component (22).

3. The pilot valve structure according to claim 2, characterized in that: At least one positioning column (217) is provided on the second joint surface in the pilot valve cover (21), and a positioning sleeve (220) is provided on the outer surface of the pilot component (22). The positioning column (217) can be inserted into the positioning sleeve (220) to relatively position the pilot valve cover (21) and the pilot component (22).

4. The pilot valve structure according to claim 3, characterized in that: The positioning sleeves (220) of the pilot component (22) are multiple and evenly distributed on the outer surface of the pilot component (22), and a plurality of positioning columns (217) are arranged in the pilot valve cover (21) to adapt to the positioning sleeves (220).

5. The pilot valve structure according to claim 4, characterized in that: The second joint surface (212) in the pilot valve cover and / or the first joint surface (222) of the pilot member (22) are provided with an arc structure for facilitating the passage of fluid, and the arc structure is formed in the pilot flow path.

6. The pilot valve structure according to claim 1, characterized in that: The piston assembly can be compressed by the slide valve core against the side wall of the piston chamber (240), can reset the slide valve core to a neutral switching position when the pilot fluid pressure does not act on it, and can push the slide valve core under the action of the pilot fluid pressure.

7. The pilot valve structure according to claim 1, characterized in that: A top column (2415) is provided on the outer surface of the first shell (241), and the top column (2415) can at least partially enter the valve hole of the main valve body (100) adjacent to the pilot valve part (200) and push the valve core of the sliding valve.

8. The pilot valve structure according to claim 7, characterized in that: The first shell (241) and / or the second shell (242) is provided with a vent hole (243), and when the piston assembly (24) is compressed, the fluid in the inner cavity can be discharged from the vent hole (243).

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