Pilot valve driving mechanism and pilot valve

Abstract

The utility model discloses a pilot valve driving mechanism and a pilot valve, and belongs to the technical field of valves, the driving mechanism comprises a coil winding, a movable iron core and a static iron core, the movable iron core is close to one end of the static iron core, the static iron core is close to one end of the movable iron core, and the coil winding is arranged between the movable iron core and the static iron core. Wherein a conical groove is formed in one of the conical grooves, and a conical protrusion is arranged on the other conical groove; according to the conical groove and the conical protrusion, in the axis direction of the coil winding, the size of one end is larger than that of the other end; the size of the conical groove and the size of the conical protrusion meet the condition that in the process that the movable iron core moves along the axis of the coil winding, the conical protrusion is embedded into the conical groove, and the depth of the part, embedded into the conical groove, of the conical protrusion changes along with axis movement. According to the pilot valve driving mechanism provided by the scheme, the variable quantity of electromagnetic force borne by the valve rod in the axial movement process of the movable iron core can be effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a pilot valve driving mechanism and a pilot valve. Background Art

[0002] Taking electromagnetically driven valves as an example, for medium-pressure, high-pressure, and ultra-high-pressure pipelines, when the pressure of the medium in the pipeline on the valve disc is relatively large, a large pulling force or thrust is required to open the valve. At this time, the valve opening and closing can be achieved by increasing the power of the electromagnetic drive mechanism. The problems that follow are high energy consumption of the electromagnetic drive mechanism and prominent heating of the electromagnetic drive mechanism. To solve this problem, a pilot valve based on an electromagnetic drive mechanism is proposed in the prior art. The specific scheme is as follows: the pilot valve includes a main valve and an auxiliary valve (also referred to as a pilot valve or a pilot valve), the main valve serves as a control valve for the pipeline medium, and the auxiliary valve is provided with a main valve control pipeline. The specific working method is as follows: the electromagnetic drive mechanism only controls the opening and closing of the auxiliary valve, and the auxiliary valve adjusts the valve front medium in the main valve control pipeline under different opening and closing states to change the effect of the valve front medium on the main valve, and uses the medium in the main valve control pipeline to act on the valve core of the main valve to control the opening and closing state of the main valve. In this way, the opening and closing state of the valve requiring a large force for opening and closing adjustment can be controlled by using a relatively small-power electromagnetic drive mechanism.

[0003] In the prior art, such as the technical solution provided in the patent application document with application number CN202310742280.2, the electromagnetic drive mechanism includes a shell, an electromagnetic coil installed in the shell, and an iron core assembly centered relative to the electromagnetic coil, and the iron core assembly includes an iron core and a driving rod.

[0004] The pilot valve based on the electromagnetic drive mechanism is used in various fields. In order to ensure the performance of this type of pilot valve, it is necessary to further optimize the relevant structure of the pilot valve. Utility Model Content

[0005] In view of the above-mentioned problem of further optimizing the pilot valve based on the electromagnetic drive mechanism, the utility model provides a pilot valve drive mechanism and a pilot valve. The pilot valve drive mechanism provided by this scheme can effectively reduce the change in the electromagnetic force exerted on the valve stem during the axial movement of the moving iron core.

[0006] In view of the above problems, a pilot valve driving mechanism and a pilot valve provided by the utility model solve the problems through the following technical points: a pilot valve driving mechanism comprises a coil winding, a moving iron core and a static iron core arranged inside the coil winding, and a conical groove is arranged on one end of the moving iron core close to the static iron core and a conical protrusion is arranged on the other end of the static iron core close to the moving iron core;

[0007] Both the conical groove and the conical protrusion are such that, in the axial direction of the coil winding, the size of one end is larger than that of the other end.

[0008] The size of the conical groove and the size of the conical protrusion satisfy that during the movement of the moving iron core along the axis of the coil winding, the conical protrusion is embedded in the conical groove, and the depth of the conical protrusion embedded in the conical groove changes with the movement along the axis.

[0009] In the specific application of this solution, it is installed on the valve body of the pilot valve and serves as the electromagnetic driving mechanism of the pilot valve. For example, in the technical solution provided by the patent application number CN201410522658.9, the moving iron core is connected to the auxiliary valve spool through a valve stem. When the coil winding works, it changes the position of the moving iron core on the axis of the coil winding, and the auxiliary valve spool moves synchronously with the moving iron core. The medium in front of the valve changes the acting mode on the main valve spool under the action of the auxiliary valve spool, so as to achieve the purpose of controlling the fluid medium connected to the main valve. In summary, during the execution of the action by the pilot valve, there is a process in which the coil winding drives the moving iron core to move, and during this process, the relative position between the static iron core and the moving iron core changes.

[0010] In view of the fact that the relative position between the moving iron core and the static iron core changes during the action of the driving mechanism, and the above changes will cause the magnetic circuit on the driving mechanism to change, resulting in the electromagnetic force on the moving iron core changing with the square of the distance between the moving iron core and the static iron core, this solution provides a solution of setting the conical groove and the conical protrusion, so that during the movement of the moving iron core along the axis of the coil winding, the conical protrusion is embedded in the conical groove. Specifically, the two are: the end of the moving iron core close to the static iron core and the end of the static iron core close to the moving iron core. During the relative movement between the moving iron core and the static iron core, compared with setting both of the above to an equal-diameter columnar structure, due to the assembly feature of the conical protrusion being embedded in the conical groove in this solution, when the moving iron core moves the same displacement to drive the valve stem to move the required distance, compared with the mating relationship formed by the equal-diameter columnar structure, the above embedding relationship makes the change amount of the distance between the side surface of the conical groove and the conical protrusion smaller than the displacement amount of the moving iron core, so that the change amount of the magnetic field between the moving iron core and the static iron core caused by the movement is reduced, and the change amount of the electromagnetic force on the moving iron core during the entire movement process is reduced, thus achieving the purpose of effectively reducing the change amount of the electromagnetic force on the valve stem during the axial movement of the moving iron core.

[0011] Preferably, the conical groove and the conical protrusion satisfy that within the stroke range of the moving iron core, the conical protrusion always maintains the relationship of being embedded in the conical groove. In this way, when the driving mechanism works, the moving iron core has the characteristic that the magnitude of the electromagnetic force on the valve stem is relatively stable during the entire movement process.

[0012] As a further technical solution of the driving mechanism of the pilot valve:

[0013] The outer shape of the conical groove is the same as that of the conical protrusion. The "same" means that after the conical protrusion is completely embedded in the conical groove, the conical surface on the outer side of the conical protrusion and the conical surface on the inner side of the conical groove form a surface fitting relationship where they fit together.

[0014] The axis of the conical groove is collinear with the axis of the conical protrusion. This solution is that the outer side surface of the conical protrusion has a shape characteristic that coincides with the groove surface of the conical groove. In this way, at the end position where the moving iron core moves towards the static iron core, not only can the static iron core provide a conical support surface for the moving iron core to provide a large-area support, but also, during the movement of the moving iron core, the side surface of the conical protrusion on it has an attitude parallel to the groove surface of the conical groove, which is beneficial to further maintaining the relative stability of the electromagnetic force received by the valve stem during the entire movement process of the moving iron core.

[0015] The moving iron core is arranged above the static iron core;

[0016] As a technical solution with a simple structure, convenient processing and assembly, and capable of avoiding the components on the driving mechanism from being affected by eccentric forces during operation, the conical protrusion is arranged at the lower end of the moving iron core. The conical protrusion is centered on the moving iron core, and the position with the largest dimension of the conical protrusion is located at the upper end of the conical protrusion;

[0017] The conical groove is arranged at the upper end of the static iron core. The conical groove is centered on the static iron core, and the position with the largest dimension of the conical groove is located at the upper end of the conical groove. In this solution, the conical protrusion is coaxial with the moving iron core, and the conical groove is coaxial with the static iron core. A further solution is that the valve stem passes through the static iron core and extends below the static iron core to act on the auxiliary valve spool.

[0018] To facilitate the protection of relevant components, it further includes a housing for covering the outside of the coil winding. In the specific application of this solution, for the solution where the moving iron core is arranged above the static iron core, it can be set that the lower end of the housing is fixed on the valve body of the pilot valve and the mating surface is sealed with a gasket, and a return spring is arranged between the lower end of the valve stem and the valve body to support the valve stem in a high position state through the return spring when the coil winding is powered off. At this time, the auxiliary valve spool is also in a high position state, and the moving ring seat is directly or indirectly supported on the inner side of the top cover of the housing; when the coil winding is powered on, the moving iron core moves downward and compresses the return spring, causing the auxiliary valve spool to move downward with the valve stem to a low position state to change the action mode of the auxiliary valve on the medium in front of the valve. The housing is used to isolate the driving mechanism parts from external force damage and protect the coil winding from moisture. Preferably, for application occasions with large changes in ambient temperature, to achieve overheat protection of the coil winding and reduce performance attenuation during operation, it is set that a heat insulation pad is arranged on the inner side of the housing, and cooling medium circulation holes are reserved on the housing to reduce the influence of temperature on the performance of the coil winding by means of efficient forced cooling.

[0019] For the variable temperature environment described above, especially when the temperature of the medium in the main valve pipeline fluctuates greatly, in order to reduce the degree of deterioration of the cooperation relationship between the valve stem and related parts caused by temperature changes, the moving iron core is arranged above the static iron core;

[0020] It further includes a valve stem, and the valve stem is a split structure including an upper valve stem and a lower valve stem. The upper valve stem is fixed to the moving iron core, and the lower valve stem is arranged below the upper valve stem;

[0021] It further includes a return spring for providing elastic support to the lower valve stem. In this solution, the high position state of the valve stem is maintained by the return spring. Specifically, the return spring pushes the lower valve stem, and the lower valve stem pushes the upper end of the upper valve stem through its upper end, pushing the auxiliary valve spool, the lower valve stem, the upper valve stem, and the moving iron core to the high position state. After the coil winding is energized, the moving iron core presses down the upper valve stem, the upper valve stem presses down the lower valve stem, and the lower valve stem pushes the auxiliary valve spool and the return spring, pushing the auxiliary valve spool to another axial position of the auxiliary valve body. Due to the adoption of the above structural form, although the valve stem is a split design including an upper valve stem and a lower valve stem, the upper valve stem and the lower valve stem always have an interaction relationship in the above two driving mechanism states, that is, the valve stem always has the required function. At the same time, in this structure, the valve stem is no longer an integral rod in the prior art. For example, when the upper end of the lower valve stem undergoes lateral displacement under temperature change, through the lateral displacement of the upper end of the lower valve stem relative to the lower end of the upper valve stem, the upper valve stem will not undergo synchronous lateral displacement, thereby achieving the purpose of protecting the related parts of this driving mechanism.

[0022] A preferred application is: in the axial direction of the valve stem, the moving iron core, the static iron core, the auxiliary valve, and the main valve are arranged in sequence. The auxiliary valve spool is slidably fitted in the auxiliary valve body. The static iron core is fixed coaxially with the coil winding through a housing. The lower valve stem is floatingly installed on the auxiliary valve spool in the radial direction through a rubber sealing ring between the lower valve stem and the auxiliary valve spool. The upper end of the lower valve stem is in clearance fit with the central hole of the static iron core. In this way, it can provide anti-wear protection for the corresponding moving parts on the driving mechanism to a certain extent.

[0023] Since the lower valve stem is closer to the medium communicating with the main valve, the temperature change of the medium on the main valve has a more obvious impact on the lower valve stem than on the upper valve stem. Preferably, as a technical solution considering the possible radial displacement of the valve stem and making the cooperation relationship of this driving mechanism relatively compact, a central hole is provided on the static iron core, and the lower end of the upper valve stem and the upper end of the lower valve stem are both embedded in the central hole;

[0024] The clearance between the lower end of the upper valve stem and the central hole is smaller than the clearance between the upper end of the lower valve stem and the central hole.

[0025] To improve the magnetic efficiency of this driving mechanism and restrict the movement trajectory of the moving iron core, it further includes a magnetic isolation sleeve disposed between the moving iron core and the coil winding. The magnetic isolation sleeve is fixed relative to the coil winding, and the moving iron core is slidably fitted inside the magnetic isolation sleeve. In this solution, the magnetic isolation sleeve is made of a magnetic isolation material, so that as many magnetic induction lines generated during the operation of the coil winding can pass through the moving iron core as possible, and the movement trajectory accuracy of the moving iron core is ensured by the constraint of the inner wall of the magnetic isolation sleeve on the moving iron core.

[0026] Similarly, for the thermal deformation that may occur in each component during the operation of this driving mechanism, in order to better protect the components of the driving mechanism, both the magnetic isolation sleeve and the static iron core are in clearance fit inside the coil winding, so that there is a space for adapting to thermal deformation between the magnetic isolation sleeve and the coil winding, and between the static iron core and the coil winding.

[0027] As a specific way of fixing the magnetic isolation sleeve, the lower end of the magnetic isolation sleeve is connected to the upper end of the static iron core by snap - fitting through a card slot. During specific implementation, the lower end of the static iron core is supported on the valve body of the pilot valve. The static iron core realizes axial support and radial side - shift limitation for the magnetic isolation sleeve. The upper end of the magnetic isolation sleeve can be constrained by the pressure provided by the cover to be constrained at a specific axial position and radial position of the driving mechanism.

[0028] This solution also relates to a pilot valve, including a valve body and a driving mechanism connected to the valve body. The driving mechanism is the driving mechanism described in any one of the above. The pilot valve is a specific application of the driving mechanism.

[0029] As a further technical solution of the pilot valve:

[0030] It further includes a valve body. The valve body includes a sub - valve body, and a sub - valve spool is arranged in the sub - valve body. The moving iron core is connected to the sub - valve spool through a valve stem.

[0031] A return spring is arranged at the end of the valve stem away from the driving mechanism and supported between the sub - valve body and the valve stem. A tapered section is arranged at the end of the valve stem away from the driving mechanism. The size of the end of the tapered section close to the driving mechanism is smaller than the size of the other end of the tapered section.

[0032] The valve stem passes through the sub - valve spool through the central hole on the sub - valve spool. A stepped surface is arranged on the central hole, and a sealing ring is further clamped between the stepped surface and the tapered section.

[0033] The reset spring and the sealing ring are used to achieve the following: the reset spring provides a thrust force towards the small end of the tapered section for the valve stem through elastic recovery. Under the action of this thrust force, the sealing ring is extruded and seals the gap between the central hole on the auxiliary valve spool and the valve stem. This solution is a method for controlling the state of the auxiliary valve. When the coil winding is powered off, the state of the auxiliary valve is controlled by the tapered section supporting the sealing ring and the sealing ring supporting the auxiliary valve spool. When the coil winding is powered on, the state of the auxiliary valve is controlled by providing a thrust force for the auxiliary valve body through a step on the valve stem. In the radial direction, since the sealing ring realizes the axial sealing of the gap between the valve stem and the auxiliary valve spool, and the sealing ring can undergo elastic deformation, the valve stem can be assembled to be floatingly installed on the auxiliary valve spool in its radial direction.

[0034] The utility model has the following beneficial effects:

[0035] Due to the assembly feature of the tapered protrusion being embedded in the tapered groove in this solution, when the moving iron core moves the same displacement to drive the valve stem to move the required distance, compared with the mating relationship formed by the equal-diameter columnar structure, the above-mentioned embedding relationship makes the change amount of the distance between the side of the tapered groove and the tapered protrusion less than the displacement of the moving iron core. As a result, the change amount of the magnetic field between the moving iron core and the static iron core due to the movement is reduced, and the change amount of the electromagnetic force received by the moving iron core during the entire movement process is reduced, thereby achieving the purpose of effectively reducing the change amount of the electromagnetic force received by the valve stem during the axial movement of the moving iron core. Description of the Drawings

[0036] Figure 1 It is the front view of a specific embodiment of the pilot valve described in this solution;

[0037] Figure 2 is Figure 1 The cross-sectional view obtained by cutting along the indicated A-A direction.

[0038] The reference numerals in the figure are respectively: 1. Cover shell, 2. Auxiliary valve body, 3. Main valve body, 4. Upper valve stem, 5. Lower valve stem, 6. Auxiliary valve spool, 7. Reset spring, 8. Main valve spool, 9. Main valve stem, 10. Static iron core, 11. Moving iron core, 12. Coil winding, 13. Magnetic isolation sleeve, 14. Tapered groove, 15. Tapered protrusion, 16. Tapered section. Detailed Description of the Specific Embodiment

[0039] The following further detailed description of the present utility model is given in conjunction with the embodiments, but the present utility model is not limited to the following embodiments:

[0040] Embodiment 1:

[0041] Such as Figure 1 and Figure 2As shown in the figure, a pilot valve driving mechanism includes a coil winding 12, a moving iron core 11 arranged inside the coil winding 12, and a stationary iron core 10. On one of the following two ends: one end of the moving iron core 11 close to the stationary iron core 10, and one end of the stationary iron core 10 close to the moving iron core 11, a conical groove 14 is provided on one of them, and a conical protrusion 15 is provided on the other.

[0042] Both the conical groove 14 and the conical protrusion 15 are such that in the axial direction of the coil winding 12, the size of one end is larger than that of the other end.

[0043] The size of the conical groove 14 and the size of the conical protrusion 15 are such that during the movement of the moving iron core 11 along the axis of the coil winding 12, the conical protrusion 15 is inserted into the conical groove 14, and the depth of insertion of the conical protrusion 15 into the conical groove 14 changes with the movement along the axis.

[0044] When this solution is specifically applied, it is installed on the valve body of the pilot valve and serves as the electromagnetic driving mechanism of the pilot valve. For example, in the technical solution provided in the patent application No. CN201410522658.9, the moving iron core 11 is connected to the secondary valve spool 6 through a valve stem. When the coil winding 12 operates, it changes the position of the moving iron core 11 on the axis of the coil winding 12. The secondary valve spool 6 moves synchronously with the moving iron core 11. The medium in front of the valve changes the acting mode on the main valve spool 8 under the action of the secondary valve spool 6, so as to achieve the purpose of controlling the fluid medium connected to the main valve. In summary, during the process of the pilot valve performing an action, there is a process in which the coil winding 12 drives the moving iron core 11 to move, and during this process, the relative position between the stationary iron core 10 and the moving iron core 11 changes.

[0045] In this solution, during the operation of the drive mechanism, the relative position between the moving iron core 11 and the stationary iron core 10 changes. This change causes the magnetic circuit on the drive mechanism to change, resulting in the electromagnetic force on the moving iron core 11 varying with the square of the distance between the moving iron core 11 and the stationary iron core 10. A solution is provided by setting the conical groove 14 and the conical protrusion 15. During the movement of the moving iron core 11 along the axis of the coil winding 12, the conical protrusion 15 is inserted into the conical groove 14. Specifically, the two ends are: the end of the moving iron core 11 close to the stationary iron core 10 and the end of the stationary iron core 10 close to the moving iron core 11. During the relative movement between the moving iron core 11 and the stationary iron core 10, compared with setting both of the above two ends as equal-diameter cylindrical structures, due to the assembly feature that the conical protrusion 15 is inserted into the conical groove 14 in this solution, when the moving iron core 11 moves the same displacement to drive the valve rod to move the required distance, compared with the mating relationship formed by the equal-diameter cylindrical structure, the above insertion relationship makes the change in the distance between the side surface of the conical groove 14 and the conical protrusion 15 smaller than the displacement of the moving iron core 11. As a result, the change in the magnetic field between the moving iron core 11 and the stationary iron core 10 caused by the movement is reduced, and the change in the electromagnetic force on the moving iron core 11 during the entire movement is reduced, thereby effectively reducing the change in the electromagnetic force on the valve rod during the axial movement of the moving iron core 11.

[0046] Preferably, the conical groove 14 and the conical protrusion 15 satisfy that within the stroke range of the moving iron core 11, the conical protrusion 15 is always in an inserted relationship with the conical groove 14. In this way, when the drive mechanism works, the electromagnetic force on the valve rod can be relatively stable during the entire movement of the moving iron core 11.

[0047] Embodiment 2:

[0048] This embodiment is further refined on the basis of Embodiment 1:

[0049] The outer shape of the conical groove 14 is the same as that of the conical protrusion 15. The sameness means that after the conical protrusion 15 is completely inserted into the conical groove 14, the conical surface on the outside of the conical protrusion 15 and the conical surface on the inside of the conical groove 14 form a surface fitting relationship.

[0050] The axis of the conical groove 14 is collinear with the axis of the conical protrusion 15. This solution means that the outer side surface of the conical protrusion 15 has a shape feature that coincides with the groove surface of the conical groove 14. In this way, at the end position when the moving iron core 11 moves towards the stationary iron core 10, not only can the stationary iron core 10 provide a conical support surface for the moving iron core 11 to provide a large-area support, but also during the movement of the moving iron core 11, the side surface of the conical protrusion 15 on it has a posture parallel to the groove surface of the conical groove 14, which is beneficial to further maintaining the relative stability of the electromagnetic force on the valve rod during the entire movement of the moving iron core 11.

[0051] Example 3:

[0052] This embodiment is further refined on the basis of Embodiment 1:

[0053] The moving iron core 11 is arranged above the static iron core 10;

[0054] As a technical solution with simple structure, convenient processing and assembly, and can avoid the components on the driving mechanism being affected by eccentric force during operation, the conical protrusion 15 is arranged at the lower end of the moving iron core 11. The conical protrusion 15 is centered on the moving iron core 11, and the position with the largest size of the conical protrusion 15 is located at the upper end of the conical protrusion 15;

[0055] The conical groove 14 is arranged at the upper end of the static iron core 10. The conical groove 14 is centered on the static iron core 10, and the position with the largest size of the conical groove 14 is located at the upper end of the conical groove 14. In this solution, the conical protrusion 15 is coaxial with the moving iron core 11, and the conical groove 14 is coaxial with the static iron core 10. A further solution is that the valve stem passes through the static iron core 10 and extends to the lower part of the static iron core 10 to act on the auxiliary valve spool 6.

[0056] Example 4:

[0057] This embodiment is further refined on the basis of Embodiment 1:

[0058] To facilitate the protection of related components, it further includes a housing 1 for covering the outside of the coil winding 12. In the specific application of this solution, for the above solution where the moving iron core 11 is arranged above the static iron core 10, it can be set that the lower end of the housing 1 is fixed on the valve body of the pilot valve and the mating surface is sealed by a gasket, and a return spring 7 is arranged between the lower end of the valve stem and the valve body to support the valve stem in a high position state through the return spring 7 when the coil winding 12 is powered off. At this time, the auxiliary valve spool 6 is also in a high position state, and the moving ring seat is directly or indirectly supported on the inner side of the top cover of the housing 1; when the coil winding 12 is powered on, the moving iron core 11 moves downward and compresses the return spring 7, so that the auxiliary valve spool 6 moves with the valve stem to a low position state to change the action mode of the auxiliary valve on the medium in front of the valve. The housing 1 is used to isolate the driving mechanism parts from external force damage and protect the coil winding 12 from moisture. Preferably, for the application occasions with large environmental temperature changes, in order to achieve overheat protection of the coil winding 12 and reduce the performance attenuation during operation, it is set that there is a heat insulation pad on the inner side of the housing 1 and cooling medium circulation holes are reserved on the housing 1 to reduce the influence of temperature on the performance of the coil winding 12 by means of efficient forced cooling.

[0059] Example 5:

[0060] This embodiment is further refined on the basis of Embodiment 1:

[0061] For the variable temperature environment described above, especially when the medium temperature in the main valve pipeline fluctuates greatly, in order to reduce the degree of deterioration of the cooperation relationship between the valve stem and related parts caused by temperature changes, the moving iron core 11 is arranged above the static iron core 10;

[0062] It further includes a valve stem, and the valve stem is a split structure including an upper valve stem 4 and a lower valve stem 5. The upper valve stem 4 is fixed on the moving iron core 11, and the lower valve stem 5 is arranged below the upper valve stem 4;

[0063] It further includes a return spring 7 for elastically supporting the lower valve stem 5. In this solution, the high position state of the valve stem is maintained by the return spring 7. Specifically, the return spring 7 pushes the lower valve stem 5, and the lower valve stem 5 pushes the upper end of the upper valve stem 4 through the upper end, pushing the auxiliary valve spool 6, the lower valve stem 5, the upper valve stem 4, and the moving iron core 11 to the high position state. After the coil winding 12 is energized, the moving iron core 11 presses down the upper valve stem 4, the upper valve stem 4 presses down the lower valve stem 5, and the lower valve stem 5 pushes the auxiliary valve spool 6 and the return spring 7, pushing the auxiliary valve spool 6 to another axial position of the auxiliary valve body 2. Due to the adoption of the above structural form, although the valve stem is a split design including the upper valve stem 4 and the lower valve stem 5, the upper valve stem 4 and the lower valve stem 5 always have an interaction relationship in the above two driving mechanism states, that is, the valve stem always has the required function. At the same time, in this structure, the lower valve stem 5 is no longer an integral rod in the prior art. For example, when the upper end of the lower valve stem 5 undergoes lateral displacement under temperature change, the upper end of the lower valve stem 5 laterally displaces relative to the lower end of the upper valve stem 4, so that the upper valve stem 4 does not undergo synchronous lateral displacement, thereby achieving the purpose of protecting the relevant parts of this driving mechanism.

[0064] A preferred application is: in the axial direction of the valve stem, the moving iron core 11, the static iron core 10, the auxiliary valve, and the main valve are arranged in sequence. The auxiliary valve spool 6 is slidably fitted in the auxiliary valve body 2. The static iron core 10 is fixed coaxially with the coil winding 12 through the housing 1. The lower valve stem 5 is floatingly installed on the auxiliary valve spool 6 in the radial direction through a rubber sealing ring between the lower valve stem 5 and the auxiliary valve spool 6. The upper end of the lower valve stem 5 is in clearance fit with the central hole of the static iron core 10. In this way, wear protection can be provided to the corresponding moving parts on the driving mechanism to a certain extent.

[0065] Embodiment 6:

[0066] This embodiment is further refined on the basis of Embodiment 5:

[0067] Since the lower valve stem 5 is closer to the medium communicating with the main valve, the influence of the temperature change of the medium on the main valve on the lower valve stem 5 is more obvious than that on the upper valve stem 4. Preferably, as a technical solution considering the possible radial uniqueness of the valve stem and making the driving mechanism have a relatively compact fitting relationship, a central hole is provided on the static iron core 10, and the lower end of the upper valve stem 4 and the upper end of the lower valve stem 5 are both embedded in the central hole;

[0068] The clearance between the lower end of the upper valve stem 4 and the central hole is smaller than the clearance between the upper end of the lower valve stem 5 and the central hole.

[0069] Embodiment 7:

[0070] This embodiment is further refined on the basis of Embodiment 1:

[0071] To improve the magnetic efficiency of the driving mechanism and restrict the movement trajectory of the moving iron core 11, a magnetic isolation sleeve 13 is further included between the moving iron core 11 and the coil winding 12. The magnetic isolation sleeve 13 is fixed relative to the coil winding 12, and the moving iron core 11 is slidably fitted inside the magnetic isolation sleeve 13. In this solution, the magnetic isolation sleeve 13 is made of a magnetic isolation material so that as many magnetic induction lines generated during the operation of the coil winding 12 can pass through the moving iron core 11 as possible, and the movement trajectory accuracy of the moving iron core 11 is ensured by the constraint of the inner wall of the magnetic isolation sleeve 13 on the moving iron core 11.

[0072] Embodiment 8:

[0073] This embodiment is further refined on the basis of Embodiment 7:

[0074] The same as above, for the possible thermal deformation of each component during the operation of the driving mechanism, in order to better protect the components of the driving mechanism, the magnetic isolation sleeve 13 and the static iron core 10 are both in clearance fit inside the coil winding 12, so that there is a space for adapting to thermal deformation between the magnetic isolation sleeve 13 and the coil winding 12, and between the static iron core 10 and the coil winding;

[0075] As a specific fixing method of the magnetic isolation sleeve 13, the lower end of the magnetic isolation sleeve 13 is connected to the upper end of the static iron core 10 by clamping through a card slot. In specific implementation, the lower end of the static iron core 10 is supported on the valve body of the pilot valve. The static iron core 10 realizes axial support and radial side shift limitation for the magnetic isolation sleeve 13. The upper end of the magnetic isolation sleeve 13 can be constrained by the pressure provided by the housing 1 to confine the magnetic isolation sleeve 13 at a specific axial position and radial position of the driving mechanism.

[0076] Embodiment 9:

[0077] Based on Embodiment 1, this embodiment provides a pilot valve, which includes a valve body and a driving mechanism connected to the valve body. The driving mechanism is the driving mechanism described in Embodiment 1. The pilot valve is a specific application of the driving mechanism.

[0078] Embodiment 10:

[0079] This embodiment is further refined based on Embodiment 9:

[0080] It further includes a valve body, the valve body includes a sub-valve body 2, a sub-valve spool 6 is arranged in the sub-valve body 2, and the moving iron core 11 is connected to the sub-valve spool 6 through a valve rod;

[0081] A return spring 7 is arranged at one end of the valve rod away from the driving mechanism and is supported between the sub-valve body 2 and the valve rod. A tapered section 16 is arranged at one end of the valve rod away from the driving mechanism. The size of one end of the tapered section 16 close to the driving mechanism is smaller than the size of the other end of the tapered section 16;

[0082] The valve rod passes through the sub-valve spool 6 through a central hole on the sub-valve spool 6. A stepped surface is arranged on the central hole, and a sealing ring is further included and clamped between the stepped surface and the tapered section 16;

[0083] The return spring 7 and the sealing ring are used to achieve: the return spring 7 provides a thrust force towards the small end of the tapered section 16 for the valve rod through elastic recovery. The sealing ring is squeezed under the action of the thrust force, and seals the gap between the central hole on the sub-valve spool 6 and the valve rod. This solution is a kind of: when the coil winding 12 is powered off, the sub-valve state is controlled by the tapered section 16 supporting the sealing ring and the sealing ring supporting the sub-valve spool 6. When the coil winding 12 is powered on, the sub-valve state is controlled by providing a thrust force for the sub-valve body 2 through a step on the valve rod. In the radial direction, since the sealing ring realizes the axial sealing of the gap between the valve rod and the sub-valve spool 6, and the sealing ring can generate elastic deformation, the valve rod can be assembled to be floatingly installed on the sub-valve spool 6 in its radial direction.

[0084] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific embodiments of the present invention are only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should all be included within the protection scope of the present invention.

Claims

1. A pilot valve driving mechanism, comprising a coil winding (12), a moving iron core (11) arranged inside the coil winding (12), and a stationary iron core (10), characterized in that: On the following two: one end of the moving iron core (11) close to the static iron core (10), and one end of the static iron core (10) close to the moving iron core (11), one of which is provided with a conical groove (14), and the other is provided with a conical protrusion (15); The conical groove (14) and the conical protrusion (15) are both such that, in the axial direction of the coil winding (12), the size of one end thereof is larger than the size of the other end thereof; The size of the conical groove (14) and the size of the conical protrusion (15) satisfy the following conditions: when the moving iron core (11) moves along the axis of the coil winding (12), the conical protrusion (15) is embedded in the conical groove (14), and the depth of the conical protrusion (15) embedded in the conical groove (14) changes with the movement of the axis.

2. A pilot valve driving mechanism according to claim 1, characterized in that: The outer shape of the conical groove (14) is consistent with the outer shape of the conical protrusion (15), and the consistency is that after the conical protrusion (15) is completely embedded in the conical groove (14), the conical surface on the outer side of the conical protrusion (15) and the conical surface on the inner side of the conical groove (14) form a mutually fitting surface fitting relationship; The axis of the tapered groove (14) is colinear with the axis of the tapered protrusion (15).

3. A pilot valve driving mechanism according to claim 1, characterized in that: The moving iron core (11) is arranged above the stationary iron core (10); The conical protrusion (15) is arranged at the lower end of the moving iron core (11), the conical protrusion (15) is arranged centrally on the moving iron core (11), and the maximum size position of the conical protrusion (15) is located at the upper end of the conical protrusion (15); The tapered groove (14) is arranged at the upper end of the static iron core (10), the tapered groove (14) is arranged centrally on the static iron core (10), and the maximum size position of the tapered groove (14) is located at the upper end of the tapered groove (14).

4. A pilot valve driving mechanism according to claim 1, characterized in that: It also comprises a cover shell (1) for covering the outside of the coil winding (12).

5. The pilot valve driving mechanism according to claim 1, characterized in that: The moving iron core (11) is arranged above the stationary iron core (10); It also includes a valve stem, which is a split structure including an upper valve stem (4) and a lower valve stem (5), wherein the upper valve stem (4) is fixed on the moving iron core (11), and the lower valve stem (5) is used to be arranged below the upper valve stem (4); It also includes a return spring (7) for providing elastic support for the lower valve stem (5).

6. A pilot valve driving mechanism according to claim 5, characterized in that: The static iron core (10) is provided with a central hole, and the lower end of the upper valve stem (4) and the upper end of the lower valve stem (5) are both embedded in the central hole; The gap between the lower end of the upper valve stem (4) and the center hole is smaller than the gap between the upper end of the lower valve stem (5) and the center hole.

7. A pilot valve driving mechanism according to any one of claims 1 to 6, characterized in that: It also includes a magnetic isolation sleeve (13) arranged between the moving iron core (11) and the coil winding (12), wherein the magnetic isolation sleeve (13) is fixed relative to the coil winding (12), and the moving iron core (11) is slidably fitted on the inner side of the magnetic isolation sleeve (13).

8. A pilot valve driving mechanism according to claim 7, characterized in that: The magnetic isolation sleeve (13) and the static iron core (10) are both loosely fitted on the inner side of the coil winding (12); The lower end of the magnetic isolation sleeve (13) is clamped and connected to the upper end of the static iron core (10) through a clamping groove.

9. A pilot valve, comprising a valve body and a driving mechanism connected to the valve body, characterized in that: The driving mechanism is the driving mechanism according to any one of claims 1 to 8.

10. The pilot valve according to claim 9, characterized in that: It also comprises a valve body, the valve body comprising an auxiliary valve body (2), an auxiliary valve core (6) is arranged in the auxiliary valve body (2), and the moving iron core (11) is connected to the auxiliary valve core (6) via a valve stem; A return spring (7) supported between the auxiliary valve body (2) and the valve stem is arranged at one end of the valve stem away from the driving mechanism, and a conical section (16) is arranged at one end of the valve stem away from the driving mechanism, wherein the size of the conical section (16) at one end close to the driving mechanism is smaller than the size of the other end of the conical section (16); The valve stem passes through the auxiliary valve core (6) through a central hole on the auxiliary valve core (6), wherein the central hole is provided with a step surface, and further comprises a sealing ring clamped between the step surface and the tapered section (16); The reset spring (7) and the sealing ring are used to achieve: the reset spring (7) provides the valve stem with a thrust toward the small end of the conical section (16) through elastic recovery, and the sealing ring is squeezed under the action of the thrust and seals the gap between the center hole on the auxiliary valve core (6) and the valve stem.

Images