Pilot-operated control valve

Abstract

The present invention prevents deterioration in operating characteristics of a control valve and can improve valve leakage characteristics by using a material having high elasticity, such as rubber, for a valve member. In a pilot-operated control valve having a main valve body which opens and closes a main valve port and which is provided with a pilot valve seat, the main valve body includes: a rubber main valve member which opens and closes the main valve port; a rubber valve port member which includes a pilot valve port and is in contact with and separated from the pilot valve shaft; and a metal shell member that restricts the elastic deformation of the main valve member and the valve port member. The shell member includes: an outer shell member that covers the main valve member and the valve port member from the outer peripheral side; and an inner case member disposed within the outer case member. The inner case member has: a body portion having a center hole that serves as a pilot passage; and a flange portion extending outward from the body portion, the outer peripheral surface of the body portion being in contact with the inner peripheral surfaces of the main valve member and the valve port member, the upper surface of the flange portion being in contact with the lower surface of the valve port member, and the lower surface being in contact with the upper surface of the main valve member.

Description

Technical Field

[0001] This invention relates to a pilot-operated control valve, and more particularly to the structure of a main valve core having a pilot valve seat. Background Technology

[0002] A pilot-operated control valve is used in refrigeration cycle devices with refrigerant circuits, such as air conditioners, refrigeration units, and freezing units. This pilot-operated control valve uses an electrical drive device such as a solenoid or electric motor to open and close the pilot valve, and the main valve opens and closes as the pilot valve opens and closes.

[0003] Figure 14 and Figure 15 This is an example of a conventional pilot-operated control valve. As shown in these figures, the control valve 51 includes: a valve body 12 having a main valve chamber 13 and a pilot valve chamber 19 internally, and having an inflow passage 14 for fluid to flow into the main valve chamber 13 and an outflow passage 15 for fluid to flow out of the main valve chamber 13; a main valve port 16 formed at an end of the outflow passage 15 on the main valve chamber 13 side; a main valve core 18 that opens and closes the outflow passage 15 by moving forward and backward relative to the main valve port 16; and a pilot passage 21. Passage 21 extends through the main valve core 18 and selectively connects the pilot valve chamber 19 and the outlet passage 15; equalizing passage 23 connects the main valve chamber 13 and the pilot valve chamber 19; pilot valve port 22 is formed at the upper end of the pilot passage 21; pilot valve shaft 20 opens and closes the pilot passage 21 by contacting and separating (abutting and separating) with the upper edge (pilot valve seat) of the pilot valve port 22; and drive device 24 drives the pilot valve shaft 20.

[0004] The pilot valve shaft 20 has a needle-shaped (inverted conical or truncated conical) tip that is inserted into the pilot valve port 22 when the valve is closed. On the other hand, the main valve core 18 has a valve component 52 and a housing component 34. The valve component 52 opens and closes the main valve port 16 by contacting and separating from the main valve seat 17, and the pilot passage 21 extends vertically through the center of the valve component 52. The housing component 34 covers the valve component 52 from its outer peripheral side. The outer peripheral surface of the housing component 34 contacts the inner peripheral surface of the main valve chamber 13 in a slidable manner, thereby supporting the main valve core 18 within the main valve chamber 13 in a vertically movable manner. To improve the sealing performance (flow blocking performance when the valve is closed) of the main valve port 16 and the pilot valve port 22, the valve component 52 is made of resin material.

[0005] In addition, the following patent document 1 discloses such a pilot-operated control valve.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent document 1: Japanese Patent Application Publication No. 2023-104598.

[0009] The technical problem that the invention aims to solve

[0010] However, in recent years, in order to improve the performance and reliability of air conditioning units, it is required to further improve valve leakage characteristics (i.e., the fluid blocking effect when the valve is closed).

[0011] Therefore, it is considered to use a more elastic material (such as rubber) instead of resin as the material constituting the valve component 52. However, if such an elastic material is used, although the valve leakage characteristics can be improved, the inner diameter of the pilot passage 21 may change due to the pressure differential load applied to the valve component 52 when the valve is closed, so the expected operating characteristics of the control valve 51 may not be obtained. In addition, the valve component 52 may easily detach from the housing component 34. Summary of the Invention

[0012] Therefore, the object of the present invention is to obtain a new main valve core structure that can eliminate the above-mentioned problems and has excellent valve leakage characteristics.

[0013] Technical means for solving technical problems

[0014] To solve the aforementioned technical problems and achieve the objectives, the pilot-operated control valve (sometimes simply referred to as a "control valve" in this application) of the present invention comprises: a valve body having a main valve chamber and a pilot valve chamber inside, and having an inflow passage for fluid (e.g., refrigerant, hereinafter the same) to flow into the main valve chamber and an outflow passage for fluid to flow out of the main valve chamber, and having a main valve port formed at the end of the outflow passage on the main valve chamber side; a main valve core that moves forward and backward relative to the main valve port; a pilot passage passing through the main valve core and selectively connecting the pilot valve chamber and the outflow passage; a pressure equalization passage connecting the main valve chamber and the pilot valve chamber; a pilot valve port formed at the end of the pilot passage on the pilot valve chamber side; a pilot valve shaft that opens and closes the pilot passage by moving forward and backward relative to the pilot valve port, and having a top end portion inserted into the pilot valve port when the valve is closed; and a drive device that drives the pilot valve shaft.

[0015] Furthermore, in this invention, the pilot valve shaft, main valve core, and main valve port are arranged sequentially along an axial direction. This axial direction is defined as the "up-down direction," the direction from the main valve core toward the pilot valve shaft is defined as "up," and the direction from the main valve core toward the main valve port is defined as "down." In addition, the "axial direction" refers to the direction of movement (movement) of the main valve core and the pilot valve shaft. However, the control valve of this invention can be used in various orientations (postures) (e.g., tilting or leaning). The terms "up" or "down" (and similarly for "upper surface," "lower surface," "upper side," "lower side," "above," "below," "upper and lower," etc.) are used for ease of understanding the relative concepts of this invention and are not limited to "down" necessarily being the direction of gravity, or "up" being the direction opposite to gravity (the same applies to the embodiments described later).

[0016] In the aforementioned control valve, the main valve core comprises an annular main valve component made of an elastic material, an annular pilot valve port component made of an elastic material, and a shell component made of a material with higher rigidity than the main valve component and the pilot valve port component. Here, the main valve component opens and closes the main valve port by contacting and separating (aggregating or separating) a main valve seat formed on the upper surface of the main valve port. The pilot valve port component includes a pilot valve port and contacts and separates from the pilot valve shaft. The shell component restricts the elastic deformation of the main valve component and the pilot valve port component. Furthermore, in this application, the main valve component and the pilot valve port component are sometimes collectively referred to as "valve component." Additionally, the pilot valve port component is sometimes simply referred to as "valve port component."

[0017] The housing component includes an outer shell component that covers the main valve component and the valve port component from the outer periphery, and an inner shell component disposed inside the outer shell component. The inner shell component further includes: a cylindrical body having a central hole extending in the vertical direction to form a pilot passage; and a plate-shaped flange extending outward from the body. Here, the outer peripheral surface of the body abuts against the inner peripheral surfaces of the main valve component and the valve port component. The upper surface of the flange abuts against the lower surface of the valve port component, and the lower surface abuts against the upper surface of the main valve component.

[0018] In the control valve of the present invention, in order to ensure good valve leakage characteristics, the main valve component and the valve port component are made of an elastic material (preferably, any one of rubber / synthetic rubber or natural rubber), and a shell component is provided on the main valve core to support them (the main valve component and the valve port component) from both the outside and the inside to inhibit deformation. The shell component includes an outer shell component and an inner shell component, which together are made of a highly rigid material (e.g., metal).

[0019] The outer casing component covers the main valve component and the valve port component from the outer periphery, suppressing deformation of these components. Conversely, the inner casing component supports the main valve component and the valve port component from the inside. Specifically, the inner casing component has a body with a central hole serving as a pilot passage. This body abuts against the inner periphery of the main valve component and the valve port component, supporting these components from the inner periphery side. The inner casing component also has a plate-shaped flange extending from the body. The flange is disposed inside the outer casing component in a manner sandwiched between the valve port component and the main valve component, supporting the valve port component from its lower surface and the main valve component from its upper surface.

[0020] In this invention, since the surfaces other than the surfaces that act on the valve components (the lower surface that contacts and separates from the main valve seat for the main valve component, and the upper surface with the pilot valve port for the valve port component) are supported by a rigid shell component in a manner that surrounds them from the inside and outside, it is possible to prevent them from deforming accidentally, even if the main valve component and valve port component are made of highly elastic materials such as rubber. This avoids adverse situations caused by deformation that is easy to occur when the valve component is made of highly elastic materials, and improves the valve leakage characteristics.

[0021] Furthermore, in this invention, from the viewpoint of preventing deformation of these components (main valve component, valve port component) and detachment from the main valve core, it is preferable that the housing component is configured to cover not only the outer peripheral surfaces of the main valve component and the valve port component, but also a portion of the lower surface of the main valve component (the portion other than the part that contacts and separates from the main valve seat, such as the periphery of the lower surface) and a portion of the upper surface of the valve port component (the portion other than the central portion where the pilot valve port is formed, such as the periphery of the upper surface). Additionally, the housing component covers the valve component to suppress deformation, but "covering" also includes the concept of a state where other components are provided between the housing component and the valve component, which is the object covered by the housing component. This is because even if other components are provided between the housing component and the valve component, the housing component can suppress deformation of the valve component via these other components. For example, in the first embodiment described later, the housing component covers the valve port component from the outer peripheral side, but a peripheral wall portion of the valve shaft stop is provided between the housing component and the valve port component.

[0022] Furthermore, when the valve is closed, the pressure inside the pilot passage, which connects to the main valve port and the outflow path, is low. On the other hand, the outer periphery of the valve component is located in the main valve chamber, which connects to the inflow path and has a high internal pressure. Therefore, due to this pressure difference, a force that flattens the pilot passage running vertically through the center of the valve component is applied to the valve component. Therefore, in the above-described structure of the existing main valve core ( Figure 14 and Figure 15In some systems, simply replacing the valve component material from resin to rubber may alter the inner diameter of the pilot passage, failing to achieve the desired operating characteristics of the control valve. In contrast, in this invention, since the pilot passage is formed using the body of a highly rigid inner shell component, such problems are prevented.

[0023] As a preferred embodiment, the control valve of the present invention may sometimes also have one to three (any combination of one or more of the following structures (1) to (3)).

[0024] (1) The main valve core is equipped with a valve shaft stop, which is made of a material with higher rigidity than the pilot valve port component and abuts against the pilot valve shaft when the valve is closed, thereby restricting the downward movement of the pilot valve shaft. If such a valve shaft stop is provided, excessive deformation of the valve port component can be prevented and the durability of the valve port component can be improved.

[0025] The aforementioned valve shaft stop, for example, has a limiting hole that is inserted into the tip of the pilot valve shaft during valve closing, thereby abutting against the tip to limit further downward movement of the pilot valve shaft. This limiting hole is positioned above the pilot valve port and has an inner diameter larger than the inner diameter of the pilot valve port but smaller than the maximum diameter of the aforementioned tip of the pilot valve shaft. Furthermore, in this case, the tip of the pilot valve shaft has an inverted conical or frustum-shaped (needle-like) shape.

[0026] (2) The main valve core has a sealing part that prevents fluid from flowing between the main valve chamber and the main valve port through the gap between the shell component and the main valve component when the valve is closed. The sealing part is formed on the outer periphery of the upper surface of the main valve component, which is outside the main valve seat.

[0027] When the valve is closed, the inner circumference of the lower surface of the annular main valve component is disposed within the main valve port, and the outer circumference of the lower surface of the main valve component is disposed within the main valve chamber. Alternatively, the inner and outer circumferences of the lower surface of the main valve component, sandwiching the main valve seat, are disposed on the inner and outer sides (within the main valve chamber) of the main valve port, respectively. Furthermore, the main valve component is disposed within the main valve core in a manner surrounded by the outer shell component (its peripheral wall), the flange of the inner shell component, and its body. The boundary surface (the surface where the two abut against each other) between the main valve component and the shell component (flange or body) extends from the main valve chamber (outer circumference of the lower surface of the main valve component), through the outer circumferential surface of the main valve component (inner circumferential surface of the peripheral wall of the outer shell component), the upper surface of the main valve component (lower surface of the flange of the inner shell component), and the inner circumferential surface of the main valve component (outer circumferential surface of the body of the inner shell component) to the main valve port (inner circumferential surface of the lower surface of the main valve component). Therefore, from the viewpoint of preventing valve leakage, it is preferable to provide a sealing portion at any point on this boundary surface.

[0028] Here, if a sealing portion is formed on the outer periphery of the upper surface of the main valve component, which is outside the main valve seat, as described in (2) above, when the valve is closed, the outer periphery of the lower surface of the main valve component (more precisely, from the part that abuts against the main valve seat to the outer edge) is subjected to high pressure in the main valve chamber. On the other hand, the low fluid pressure in the main valve port is introduced into most of the upper surface of the main valve component (more precisely, from the inner edge of the upper surface to the sealing portion) through the gap between the shell component (body and flange) and the main valve component. Thus, the main valve component is pressed upward (i.e., the lower surface of the flange of the inner shell component) by the pressure difference between the upper and lower surfaces of these main valve components. Therefore, it is possible to prevent the main valve component from falling off the main valve core when the valve is opened.

[0029] Furthermore, in the above method (2), a low-pressure inlet path can be provided, which communicates with the interior of the main valve port when the valve is closed, thereby introducing the low pressure from the outlet side into the upper surface of the outer periphery of the main valve component. This is because by forming a flow path that actively introduces the low pressure into the main valve port on the upper surface of the main valve component, the main valve component can be more reliably prevented from falling off.

[0030] The aforementioned low-pressure inlet path may, for example, include: an annular path extending circumferentially along the upper surface of the outer periphery of the main valve component; and a connecting path connecting the annular path and the interior of the main valve port. Furthermore, the connecting path may, for example, include one or more vertical paths and one or more horizontal paths, the vertical paths extending vertically along the inner periphery of the main valve component, and the horizontal paths extending radially from the upper end of the vertical paths along the upper surface of the main valve component.

[0031] (3) The flange of the inner shell component has one or more through holes, which connect the space on the upper side of the flange and the space on the lower side of the flange. The main valve component and the pilot valve port component are formed into one piece by a connecting part, which is made of the above-mentioned elastic material disposed in the through hole.

[0032] In this invention, the main valve component and the pilot valve port component do not necessarily need to be separate (i.e., different components), and can also be formed as one unit (for example, the main valve component and the pilot valve port component can also be connected). The above-described method (3) involves a structure in which, for example, the main valve component, the pilot valve port component, and the inner shell component are formed as one unit by insert molding, thereby enabling the construction of a control valve having such a structure. Furthermore, the third to fifth embodiments described later are based on this method (3).

[0033] The effects of the invention

[0034] According to the present invention, it is possible to prevent the deterioration of the operating characteristics of the control valve and to use highly elastic materials such as rubber in the valve components, thereby improving the valve leakage characteristics.

[0035] Other objects, features, and advantages of the present invention will become even clearer from the following description of embodiments of the invention based on the accompanying drawings. Furthermore, the same symbols in the figures denote the same or equivalent parts. Attached Figure Description

[0036] Figure 1 This is a longitudinal sectional view showing the open state of the pilot-operated control valve according to the first embodiment of the present invention.

[0037] Figure 2 This is a longitudinal sectional view showing the closed state of the pilot-operated control valve according to the first embodiment described above.

[0038] Figure 3 This is a longitudinal sectional view showing the enlarged main valve core of the pilot-operated control valve according to the first embodiment described above.

[0039] Figure 4 This is a longitudinal sectional view showing the enlarged main valve core of the pilot-operated control valve according to the second embodiment of the present invention.

[0040] Figure 5 This is a top view showing an enlarged view of the main valve component of the main valve core of the pilot-operated control valve according to the second embodiment described above.

[0041] Figure 6 This is an enlarged longitudinal sectional view showing the main valve component of the main valve core of the pilot-operated control valve according to the second embodiment described above.

[0042] Figure 7 This is an enlarged longitudinal sectional view of the main valve core of the pilot-operated control valve according to the third embodiment of the present invention.

[0043] Figure 8 This is a top view showing the inner shell component of the main valve core of the pilot-operated control valve according to the third embodiment described above.

[0044] Figure 9 This is a longitudinal sectional view showing the inner shell component of the main valve core of the pilot-operated control valve according to the third embodiment described above.

[0045] Figure 10 This is a bottom view showing the inner shell component of the main valve core of the pilot-operated control valve according to the third embodiment described above.

[0046] Figure 11 This is a longitudinal sectional view showing the manufacturing process of the main valve core of the pilot-operated control valve according to the third embodiment described above (the inner shell component and the valve component (main valve component and pilot valve port component) are integrally formed by embedding).

[0047] Figure 12 This is an enlarged longitudinal sectional view of the main valve core of the pilot-operated control valve according to the fourth embodiment of the present invention.

[0048] Figure 13 This is an enlarged longitudinal sectional view of the main valve core of the pilot-operated control valve according to the fifth embodiment of the present invention.

[0049] Figure 14 This is a longitudinal sectional view showing an example of an existing pilot-operated control valve (in the open state).

[0050] Figure 15 This is a longitudinal sectional view showing the enlarged main valve core of the aforementioned existing pilot-operated control valve.

[0051] Symbol Explanation

[0052] A. Axis (Central Axis), F. Fluid Flow, 11, 51. Pilot-operated Control Valve (Pilot-operated Solenoid Valve), 12. Valve Body, 13. Main Valve Chamber, 14. Inflow Path, 15. Outflow Path, 16. Main Valve Port, 17. Main Valve Seat, 18, 45, 46, 47, 48. Main Valve Core, 19. Pilot Valve Chamber, 20. Pilot Valve Shaft, 20a. Valve Shaft Body, 20b. Valve Shaft Head, 21. Pilot Passage, 22. Pilot Valve Port, 23. Pressure Equalizing Path, 24. Electromagnetic Drive Device (Drive Device), 25. Coil, 26. Sleeve, 27. Plunger, 27a. Bottom of Plunger, 27b. Peripheral Wall of Plunger, 28. Suction Component, 28a. Suction Component Body, 28b. Connecting Part, 28c. Central Hole of Suction Component Body, 28d. Central Hole of Connecting Part (Main Valve Core Guide), 29. 30 Pilot valve shaft pressing spring, 31 Piston return spring, 32 Main valve opening spring, 32a Main valve assembly, 32b Main valve assembly body, 33 Pilot valve port assembly, 34 Housing assembly, 34a Peripheral wall of housing assembly, 34b Step formed on the inner circumferential surface of housing assembly, 35 Inner housing assembly, 35a Body, 35b Flange, 35c Through hole formed on the flange of inner housing assembly, 35d Foot, 35e Locking part, 36 Valve shaft stop, 36a Top plate of valve shaft stop, 36b Peripheral wall of valve shaft stop, 36c Restriction hole, 37 Outer support, 37a Outer riveting part, 38 Inner support, 39 Upper riveting part, 40, 40a Sealing part, 41 Sealing protrusion, 42 Low-pressure inlet, 43 44. Ring road, 44. Connecting road, 44a. Vertical road, 44b. Horizontal road, 44c. The other end of the horizontal road, 52. Valve component, 60. Upper end of the protrusion (upper surface part), 61. Protrusion. Detailed Implementation

[0053] [First Implementation]

[0054] based on Figures 1 to 3 The pilot-operated control valve according to the first embodiment of the present invention will be described.

[0055] like Figures 1 to 3 As shown, the control valve 11 according to the first embodiment of the present invention is a normally open pilot-operated control valve that is in an open state when not energized. The control valve 11 includes: a valve body 12 having a main valve chamber 13 and a pilot valve chamber 19 inside, and having an inflow passage 14 for fluid (e.g., refrigerant) to flow into the main valve chamber 13 and an outflow passage 15 for fluid to flow out of the main valve chamber 13; a main valve port 16 formed at an end of the outflow passage 15 on the main valve chamber 13 side; and a main valve core 18 that moves forward and backward relative to the main valve port 16. The system includes: an opening and closing outlet path 15 (main valve port 16); a pilot passage 21 that passes through the main valve core 18 and selectively connects the pilot valve chamber 19 and the outlet path 15; an equalizing passage 23 that connects the main valve chamber 13 and the pilot valve chamber 19; a pilot valve port 22 formed at the end of the pilot passage 21 on the pilot valve chamber 19 side; a pilot valve shaft 20 that opens and closes the pilot passage 21 by moving forward and backward relative to the pilot valve port 22; and a drive device (electromagnetic drive device) 24 that drives the pilot valve shaft 20.

[0056] The drive unit 24 includes: a plunger 27 supported within a sleeve 26 (described later) to be able to slide along an axial direction (the direction in which axis A extends, as follows); an attraction member 28 that attracts the plunger 27; and a coil 25 that generates a magnetic force to attract the plunger 27.

[0057] A bottomless, open-topped longitudinal hole (with an open top and a bottom surface) extending vertically downwards from the upper surface of the valve body 12 (i.e., along the axis A of the control valve 11) serves as the main valve chamber 13. An inflow passage 14 opens at the periphery of the bottom surface of the main valve chamber 13, allowing fluid to flow into it. An outflow passage 15 opens at the center of the bottom surface of the main valve chamber 13. The upper end of the outflow passage 15, which is located on the side of the main valve chamber 13, becomes the main valve port 16.

[0058] In this embodiment, the interior of the valve body 12 becomes the main valve port 16, and the valve body 12 has an annular protrusion 61 that protrudes upward relative to its surroundings. As an example, the protrusion 61 is formed so that its end on the side of the main valve chamber 13 of the outflow passage 15 stands vertically upward and has a cylindrical shape. The interior of the protrusion 61 becomes the main valve port 16. That is, the protrusion 61 has a vertically erected wall formed in an annular cylindrical shape. Furthermore, the upper end portion (upper surface portion) 60 of the protrusion 61, which is the wall, has a longitudinal cross-sectional shape that is convex upward, for example, arc-shaped. Moreover, the apex of the upper end portion 60 of the wall is located at the center in the thickness direction of the wall. Additionally, the portion of the upper end portion (upper surface portion) 60 of the protrusion 61 that is in contact with and separated from the main valve core 18 (the main valve component 32 described later) becomes the main valve seat 17.

[0059] Furthermore, in this embodiment, the protrusion 61 is described as cylindrical as an example. As other examples, the protrusion 61 may also be a conical or frustum-shaped cylinder with a thickness that gradually increases from the top to the bottom between the outer and inner circumferential surfaces. Alternatively, the protrusion 61 may also be a hemispherical shape that protrudes upwards in a cross-section parallel to the axis passing through the axis of the protrusion 61.

[0060] The upper space of the longitudinal hole becomes the connection opening for fixing the suction component 28. The suction component 28 has: an annular connecting portion 28b, which has an external thread on its outer peripheral surface that engages with the internal thread formed on the inner peripheral surface of the connection opening, and is fixed by being screwed into the connection opening; and a cylindrical suction body 28a, which stands upright from the center of the upper surface of the connecting portion 28b.

[0061] The central hole 28d, which extends through the inner side of the connecting portion 28b in the vertical direction and is located at the center of the connecting portion 28b, serves as a main valve core guide that supports the main valve core 18 so that it can slide in the vertical direction (the direction of axis A of the control valve 11). Furthermore, the central hole 28d of the connecting portion 28b communicates with the central hole 28c of the suction body 28a, which will be described later.

[0062] A protrusion extending inward toward the center of the central hole 28d of the connecting portion 28b is formed on the lower surface of the connecting portion 28b. A main valve opening spring 31 is provided between this protrusion and the peripheral portion of the lower surface of the main valve core 18. The main valve opening spring 31 is formed of a compression coil spring (a coil spring provided in a compressed state, the same below), which applies force to the main valve core 18 upward (i.e., in the valve opening direction) and performs the function of pushing the main valve core 18 upward when the drive device 24 is not driven. In addition, a stepped portion is formed on the upper peripheral portion of the central hole (main valve core guide portion) 28d of the connecting portion 28b to stop the main valve core 18 pushed up by the main valve opening spring 31.

[0063] The suction body 28a has a central hole 28c extending vertically. A sleeve 26 is fixed to the outer peripheral surface of the upper end of the suction body 28a, rising upwards from the upper end. The sleeve 26 is a bottomless, capped (top surface closed, bottom surface open) cylindrical component, which houses a plunger 27 that can slide vertically within it. The plunger 27 has a bottom 27a and an annular peripheral wall 27b. The bottom 27a is attracted by the suction body 28a by the magnetic force generated by a coil 25 disposed on the outer periphery of the sleeve 26, and the peripheral wall 27b rises upwards from the outer periphery of the bottom 27a. A through hole is formed in the center of the bottom 27a, extending vertically through the bottom 27a and communicating with the interior of the peripheral wall 27b. Furthermore, a pilot valve shaft 20 is provided through this through hole.

[0064] The pilot valve shaft 20 has a rod-shaped valve shaft body 20a and a valve shaft head 20b with a larger outer diameter formed at the upper end of the valve shaft body 20a. The valve shaft head 20b is disposed above the bottom 27a of the plunger 27, that is, inside the peripheral wall portion 27b. On the other hand, the valve shaft body 20a is arranged to extend vertically downward through the aforementioned through hole in the bottom 27a. The top end portion (lower end portion) of the valve shaft body 20a has a needle-like (inverted conical or inverted frustum-shaped) shape, so that it can be inserted into the pilot valve port 22 to block the pilot passage 21 when the valve is closed.

[0065] Inside the peripheral wall 27b of the plunger 27, a pilot valve shaft pressing spring 29, made of a compression coil spring, is provided between the valve shaft head 20b and the top plate of the sleeve 26. Additionally, a protrusion extending toward the center of the central hole 28c is provided at the lower end of the suction body 28a, and a plunger return spring 30, also made of a compression coil spring, is provided between this protrusion and the lower surface of the plunger 27 (bottom 27a).

[0066] The pilot valve shaft pressing spring 29 applies force to the pilot valve shaft 20 in the valve-closing direction (downward), pressing the valve shaft head 20b of the pilot valve shaft 20 against the bottom 27a of the plunger 27. Meanwhile, the plunger return spring 30 applies force to the plunger 27 upward. Therefore, the plunger 27 and the pilot valve shaft 20 are in contact by mutual pushing in the axial direction and are connected in a way that allows relative movement in the axial direction. Furthermore, the plunger return spring 30 functions to pull the plunger 27 upward when the drive device 24 is not driven. Additionally, as the plunger 27 rises, the valve shaft head 20b is pulled up, and the pilot valve shaft 20 also moves upward.

[0067] The main valve core 18 includes: a main valve component 32, which opens and closes the main valve port 16 by contacting and separating from a main valve seat 17 formed on the upper surface of the main valve port 16; a valve port component (pilot valve port component) 33, which forms a pilot valve port 22; a housing component 34, which covers the main valve component 32 and the valve port component 33 from the outer periphery; an inner housing component 35, which is disposed inside the housing component 34 and supports the main valve component 32 and the valve port component 33 from the inside; and a valve shaft stop 36, which restricts the downward movement of the pilot valve shaft 20. In this embodiment, regarding the constituent materials of the components constituting the main valve core 18, the main valve component 32 and the valve port component 33 are both made of rubber (synthetic rubber or natural rubber), while the housing component 34, the inner housing component 35, and the valve shaft stop 36 are all made of metal. In addition, the pilot valve chamber 19 described above is formed on the upper side of the main valve core 18 (between the upper surface of the main valve core 18 and the lower surface of the suction body 28a).

[0068] The outer casing component 34 is a bottomless and coverless cylindrical component, and the inner casing component 35, the main valve component 32, the valve port component 33, and the valve shaft stop 36 are housed inside the annular peripheral wall portion 34a. In addition, the aforementioned pressure equalization path 23 is formed in the peripheral wall portion 34a of the outer casing component 34 in a manner that extends through the peripheral wall portion 34a in the vertical direction.

[0069] The inner shell component 35 has: a cylindrical body 35a, which is disposed at the center of the main valve core 18 in a vertically extending manner; and a circular flange 35b, which extends horizontally outward (away from the central axis A) from the outer peripheral surface of the body 35a. A hole penetrating the center of the body 35a in a vertically extending manner forms the aforementioned pilot passage 21. The main valve component 32 and the valve port component 33 are both annular components. The valve port component 33 is disposed on the upper side of the flange 35b, and the main valve component 32 is disposed on the lower side of the flange 35b, such that the body 35a is inserted into their central holes. In this state, the upper surface of the flange 35b abuts against the lower surface of the valve port component 33, and the lower surface of the flange 35b abuts against the upper surface of the main valve component 32.

[0070] The central hole of the valve port component 33 is composed of a lower hole with a larger inner diameter and an upper hole with a smaller inner diameter that are interconnected. The body 35a is inserted into the lower hole, and the upper hole becomes the aforementioned pilot valve port 22. Furthermore, this upper hole (pilot valve port 22) is interconnected with the central hole (pilot passage 21) of the body 35a. In addition, the upper edge of the pilot valve port 22 becomes a pilot valve seat for contact and separation with the top end of the pilot valve shaft 20.

[0071] A valve stem stop 36 is provided on the upper surface of the valve port component 33 to cover it. The valve stem stop 36 is a cap-shaped component, having a top plate portion 36a covering the upper surface of the valve port component 33 and a peripheral wall portion 36b extending downward from the outer periphery of the top plate portion 36a. The top plate portion 36a has a limiting hole 36c extending vertically through it at its center. The limiting hole 36c has an inner diameter that is larger than the pilot valve port 22 and smaller than the maximum outer diameter of the tip of the pilot valve stem 20 (the outer diameter of the uppermost part of the tip of the needle-shaped pilot valve stem 20), and functions to limit the downward movement of the pilot valve stem 20 so that the pilot valve stem 20 is not over-inserted into the pilot valve port 22.

[0072] When closing the valve, the pilot valve shaft 20 is inserted into the pilot valve port 22 of the valve port component 33, and the pilot valve is closed by pressing the pilot valve port 22. However, the diameter of the aforementioned limiting hole 36c is set such that the pilot valve port 22 is pressed by the pilot valve shaft 20 with a strength that ensures a seal (flow blockage) without the valve port component 33 (pilot valve port 22) being extremely flattened. As a result, residual strain (deformation and deterioration) of the valve port component 33 (pilot valve port 22) due to years of use can be suppressed, and the durability of the control valve 11 can be improved.

[0073] The main valve component 32 is an annular component with an inner diameter smaller than the diameter of the main valve port 16 (main valve seat 17) and an outer diameter larger than the diameter of the main valve port 16 (main valve seat 17), so that the lower surface of the main valve component 32 abuts against the main valve seat 17 and can block the main valve port 16.

[0074] The components constituting the main valve core 18, namely the outer shell component 34, the inner shell component 35, the main valve component 32, the valve port component 33, and the valve shaft stop 36, are integrated and move up and down together (as a single unit). However, in this embodiment, the components are integrated by means of a fixing structure. In addition, in order to achieve such fixing, an annular step portion 34b is formed on the inner circumferential surface of the outer shell component 34. Furthermore, the outer circumference of the main valve component 32 is supported by the lower end of the outer shell component 34, that is, by forming an inwardly bent protrusion (approaching the central axis A) at the lower end of the outer shell component 34 (this protrusion is called the "outer support portion", indicated by the symbol 37), thereby supporting the outer circumference of the main valve component 32 from the lower surface side. Furthermore, the inner periphery of the main valve component 32 is supported by the lower end of the body 35a of the inner shell component 35, that is, by forming an outward (away from the central axis A) protrusion at the lower end of the body 35a (this protrusion is called the "inner support part", indicated by the symbol 38), thereby supporting the inner periphery of the main valve component 32 from the lower surface side.

[0075] The inner housing component 35 places the outer periphery of the flange portion 35b on the stepped portion 34b formed on the inner peripheral surface of the outer housing component 34, and rivets the valve shaft stop 36 (this riveted portion is referred to as the "upper riveted portion" and indicated by the symbol 39) by bending the upper inner peripheral portion of the outer housing component 34 inward and downward. As a result, the peripheral wall portion 36b of the valve shaft stop 36 is pressed downward, and the flange portion 35b is clamped by the lower end of the peripheral wall portion 36b and the stepped portion 34b formed on the inner peripheral surface of the outer housing component 34. In the axial direction (i.e., the vertical direction), the inner housing component 35 is fixed inside the outer housing component 34. In the radial direction, the inner housing component 35 is fixed inside the outer housing component 34 by abutting the outer peripheral surface of the flange portion 35b against the inner peripheral surface of the outer housing component 34.

[0076] In the axial direction, the main valve component 32 is fixed by being held by the flange portion 35b of the inner shell component 35, the inner support portion 38 of the inner shell component 35, and the outer support portion 37 of the outer shell component 34. In the radial direction, the main valve component 32 is fixed by abutting the outer peripheral surface of the main valve component 32 against the inner peripheral surface of the outer shell component 34.

[0077] In the axial direction, the valve port component 33 is fixed by being held by the flange portion 35b of the inner shell component 35 and the top plate portion 36a of the valve shaft stop 36. In the radial direction, the valve port component 33 is fixed by abutting the outer peripheral surface of the body 35a of the inner shell component 35 against the inner peripheral surface of the center hole (the hole on the lower side) of the valve port component 33.

[0078] In the axial direction, the valve shaft stop 36 is fixed by being held between the flange portion 35b of the inner housing member 35 and the upper riveting portion 39 of the outer housing member 34. In the radial direction, the valve shaft stop 36 is fixed by abutting the outer peripheral surface of the peripheral wall portion 36b of the valve shaft stop 36 against the inner peripheral surface of the outer housing member 34. Furthermore, in this embodiment, the valve shaft stop 36 is provided as a component distinct from the outer housing member 34; however, for example, as described in the third to fifth embodiments below, the valve shaft stop 36 may be configured as an integral component with the outer housing member 34.

[0079] In this embodiment, the inner periphery of the upper surface of the main valve component 32 is pressed against the lower surface of the flange portion 35b of the inner housing component 35 by the inner support portion 38, thereby forming a sealing portion 40. Specifically, the main valve component 32 has an annular sealing protrusion protruding upwards at its inner periphery of its upper surface (although the location differs, it has the same structure as the sealing protrusion 41 in the second embodiment). When the inner periphery of the main valve component 32 is sandwiched between the inner support portion 38 and the flange portion 35b, and the main valve component 32 is placed in the inner housing component 35 (with the lower end of the body 35a inserted into the central hole of the annular main valve component 32), the inner periphery of the main valve component 32 is pressed upwards by the inner support portion 38 to flatten the sealing protrusion. Thus, a sealing portion 40 is formed at the inner periphery of the upper surface of the main valve component 32. The sealing part 40 functions as follows: to prevent liquid from leaking from the main valve chamber 13 to the outlet passage 15 (main valve port 16) through the gaps between the main valve component 32 and the outer shell component 34 to the inner shell component 35 (more precisely, the gap between the inner peripheral surface of the outer shell component 34 and the outer peripheral surface of the main valve component 32, the gap between the upper surface of the main valve component 32 and the lower surface of the flange portion 35b of the inner shell component 35, and the gap between the outer peripheral surface of the body portion 35a of the inner shell component 35 and the inner peripheral surface of the main valve component 32) when the valve is closed.

[0080] In the control valve of this embodiment, the plunger 27, pilot valve shaft 20, suction component 28 (suction component body 28a and connecting part 28b), main valve core 18 (outer shell component 34, body 35a and flange part 35b of inner shell component 35, main valve component 32, and valve port component 33), pilot passage 21 (pilot valve port 22), and main valve port 16 (main valve seat 17) are arranged coaxially, and their central axis is consistent with the axis A of the control valve 11.

[0081] The operation of the control valve 11 in this embodiment is as follows.

[0082] When the drive device 24 is not driven (when the coil 25 is not energized), such as Figure 1As shown, due to the force of the plunger return spring 30, the plunger 27 overcomes the force of the pilot valve shaft pressing spring 29 and is pushed upward, pressing against the top plate of the sleeve 26. Simultaneously, the pilot valve shaft 20 is pulled upward by the plunger 27, opening the pilot passage 21 (pilot valve port 22). Therefore, the fluid flowing into the main valve chamber 13 from the inflow passage 14 and into the pilot valve chamber 19 through the equalizing passage 23 does not accumulate in the pilot valve chamber 19 but is discharged through the pilot passage 21 from the outlet passage 15. Therefore, the pressure in the pilot valve chamber 19 does not increase, and the main valve core 18 is pushed upward (in the opening direction) by the force of the main valve opening spring 31, opening the main valve port 16. In this open state, the fluid that has flowed into the main valve chamber 13 from the inflow passage 14 flows out through the main valve port 16 from the outlet passage 15 (refer to arrow F).

[0083] When energized to coil 25 from the open valve state, plunger 27 is attracted by the suction body 28a and overcomes the force of plunger return spring 30, thus being pressed down. Simultaneously, pilot valve shaft 20, connected to plunger 27, moves downward as an integral part of plunger 27, and the top end of pilot valve shaft 20 inserts into pilot valve port 22, closing pilot passage 21. Furthermore, at this time, pilot valve shaft 20 is restricted from downward movement by its top outer circumferential surface abutting against the inner edge of the limiting hole 36c of valve shaft stop 36, thus preventing excessive deformation of pilot valve port 22.

[0084] When the pilot passage 21 is closed as described above, the fluid flowing into the pilot valve chamber 19 through the equalizing passage 23 is not released through the pilot passage 21 and is instead stored, causing the pressure inside the pilot valve chamber 19 to rise. Then, when the fluid pressure inside the pilot valve chamber 19 (more precisely, the pressure difference between the pilot valve chamber 19 and the main valve chamber 13) and the force exerted by the pilot valve shaft pressing spring 29 (the force by which the pilot valve shaft pressing spring 29 presses the main valve core 18 downward via the pilot valve shaft 20) exceeding the upward force exerted by the main valve opening spring 31, such as Figure 2 As shown, the main valve core 18 moves downward and sits on the main valve seat 17, becoming a closed valve.

[0085] When the energization to the coil 25 is stopped from the closed valve state, the attraction force of the suction body 28a on the plunger 27 disappears. Therefore, by the force of the plunger return spring 30, the plunger 27 is lifted against the force of the pilot valve shaft pressing spring 29, the pilot valve shaft 20 is lifted, and the pilot passage 21 is opened.

[0086] When the pilot passage 21 is open, the fluid accumulated in the pilot valve chamber 19 is discharged to the outlet passage 15 through the pilot passage 21, and the pressure in the pilot valve chamber 19 decreases. Furthermore, the cross-sectional area of ​​the pilot passage 21 is larger than that of the equalizing passage 23; therefore, a pressure differential that pulls the main valve core 18 upward is generated on the upper and lower surfaces of the main valve core 18. In addition, the main valve core 18 receives an upward force from the main valve opening spring 31. As a result, the main valve core 18 is pushed upward, and the main valve core 18 leaves the main valve seat 17, becoming the open valve state with the main valve port 16 open (refer to the above). Figure 1 Furthermore, the rising main valve core 18 stops by abutting against the stepped portion formed at the upper end of the central hole (main valve core guide portion) 28d in the connection portion 28b of the suction member 28. As a result, the pilot passage 21 becomes open, maintaining the valve open state.

[0087] [Second Implementation]

[0088] based on Figures 4-6 The second embodiment of the present invention relates to a pilot-operated control valve. Furthermore, in the description of this embodiment, structures identical or equivalent to those in the first embodiment are marked with the same symbols and their descriptions are omitted; the focus is on the differences (the same applies to embodiments after the third embodiment). Additionally, the control valves in this embodiment and embodiments after the third embodiment are identical to those in the first embodiment except for the main valve core; therefore, descriptions of the parts other than the main valve core are omitted.

[0089] The main valve core 45 of the control valve involved in this embodiment is the same as the main valve core 18 in the first embodiment, and includes a main valve component 32a, a valve port component 33, a housing component 34, an inner housing component 35, and a valve shaft stop 36. However, the main valve component 32a and its fixing structure are different from those in the first embodiment.

[0090] Specifically, Figure 5 and Figure 6 This indicates that the main valve component 32a is not located in the main valve core 45. For example... Figure 6 As shown, the main valve component 32a is an annular component made of rubber material, having a main valve component body 32b with a rectangular cross-section and an annular sealing protrusion 41 (referred to as the sealing portion in this invention) protruding upward from the upper surface of the main valve component body 32b. The rubber material can be either natural rubber or synthetic rubber. The upper surface of the main valve component body 32b is a plane orthogonal to the central axis A of the main valve component 32a. The sealing protrusion 41, located before the main valve core 45, is, for example, located in... Figure 6The cross-section shown has an upwardly protruding semi-circular shape. Furthermore, the shape of the sealing protrusion 41 can be other than the aforementioned semi-circular shape; for example, it can have a rectangular cross-sectional shape. Moreover, the rectangular sealing protrusion 41 is not strictly rectangular; its upper surface is preferably as shown... Figure 6 The cross-section shown is a curved surface that bulges upwards. The outer diameter of the main valve component 32a is larger than that of the main valve port 16. When viewed from above, the sealing protrusion 41 is positioned on the outer side (away from the central axis A) of the main valve port 16. The main valve component 32a opens and closes the main valve port 16 by contacting and separating from the main valve seat 17.

[0091] The main valve component 32a is assembled into the main valve core 45 as follows: The outer periphery of the main valve component 32a is placed on the outer support 37, and the main valve component 32a is disposed inside the outer housing component 34. Then, the lower end of the body 35a is inserted into the central hole of the annular main valve component 32a, and the inner housing component 35 is disposed inside the outer housing component 34. Then, the pilot valve port component 33 and the valve shaft stop 36 are sequentially disposed on the upper surface of the inner housing component 35, and the upper riveting portion 39 is formed by riveting (bending downward) the inner periphery of the upper surface of the outer housing component 34. During the formation of the upper riveting portion 39, the flange portion 35b of the inner shell component 35 is pressed against the stepped portion 34b formed on the inner circumferential surface of the outer shell component 34. At the same time, the outer circumferential portion of the main valve component 32a is clamped between the flange portion 35b and the outer support portion 37, and the sealing protrusion 41 is flattened by the flange portion 35b to form a sealing portion 40a. This sealing portion 40a performs the same function as the sealing portion 40 in the first embodiment (preventing fluid from leaking from the main valve chamber 13 to the outlet path 15 through the gap between the main valve component 32a and the outer shell component 34 to the inner shell component 35 when the valve is closed).

[0092] The main valve component 32a also has a low-pressure inlet passage 42 (hereinafter sometimes simply referred to as the "inlet passage"), which connects to the interior of the main valve port 16 when the valve is closed, actively introducing the low pressure from the outlet passage 15 side to the upper surface side of the main valve component 32a (between the upper surface of the main valve component 32a and the lower surface of the flange portion 35b). The inlet passage 42 includes an annular passage 43 extending circumferentially around the outer periphery of the upper surface of the main valve component 32a and a connecting passage 44 connecting the main valve port 16 to the annular passage 43.

[0093] like Figure 6As shown, an annular channel 43 is formed on the upper surface of the main valve component body 32b, and is disposed inside the sealing protrusion 41. The annular channel 43 has an integral shape, for example, circular, that is, coaxial with the main valve component body 32b (i.e., with the central axis A of the main valve component body 32b as the center). In addition, the annular channel 43 is an annular groove formed on the upper surface of the main valve component body 32b, and its cross-sectional shape is, for example, hemispherical. The annular channel 43 is disposed at a certain distance inward from the sealing protrusion 41. That is, when viewed from above, the outer edge of the annular channel 43 is discontinuous with the sealing protrusion 41.

[0094] like Figure 5 As shown, the connecting path 44 is composed of multiple vertical paths 44a extending along the inner circumferential surface of the main valve component 32a in the vertical direction and multiple horizontal paths 44b extending radially from the upper end of the vertical paths 44a along the upper surface of the main valve component 32a.

[0095] Vertical path 44a is, for example, a straight groove formed from the lower end to the upper end of the inner circumferential surface of the main valve component 32a, and its cross-sectional shape is hemispherical. For example, six vertical paths 44a are formed and are equally spaced around the central axis A of the main valve component 32a.

[0096] A horizontal path 44b is formed on the upper surface of the main valve component body 32b, for example, as a straight groove extending radially along the main valve component 32a. One end of the horizontal path 44b is connected to the upper end of the vertical path 44a. The other end 44c of the horizontal path 44b is disposed on the side of the sealing protrusion 41, extending beyond the annular path 43. The other end 44c of the horizontal path 44b is disposed on the inner side relative to the sealing protrusion 41, at a certain distance from the sealing protrusion 41. That is, when viewed from above, the sealing protrusion 41 and the horizontal path 44b are discontinuous. In this embodiment, the other end 44c of the horizontal path 44b is disposed at the middle position between the annular path 43 and the sealing protrusion 41 when viewed from above. For example, six horizontal paths 44b are formed, and are equally spaced around the central axis A of the main valve component body 32b.

[0097] Furthermore, in this embodiment, the body 35a of the inner shell component 35 does not have an inner support portion for supporting the main valve component 32a. The main valve component 32a is supported on the lower surface of the main valve core 45 only by an outer support portion 37 formed on the outer shell component 34 in the axial direction. This is because the sealing portion 40a formed by the sealing protrusion 41 and the aforementioned low-pressure inlet passage 42 perform the following functions.

[0098] In this embodiment, a sealing portion 40a is formed on the outer periphery of the upper surface of the main valve component 32a, and a low-pressure inlet passage 42 is provided. Therefore, when the valve is closed, low-pressure fluid from the outlet passage 15 side is introduced into the upper surface of the main valve component 32a through the vertical passage 44a, the horizontal passage 44b, and the annular passage 43. In this embodiment, the low-pressure inlet passage 42 is not connected to the sealing protrusion 41 (when viewed from above, the low-pressure inlet passage 42 is far from the sealing protrusion 41 and is discontinuous), but the low-pressure fluid introduced into the low-pressure inlet passage 42 passes through the gap between the upper surface of the main valve component 32a and the lower surface of the flange portion 35b, reaching a range further inward than the portion sealed by the sealing protrusion 41 (sealing portion 40a). Furthermore, in other examples of the low-pressure inlet passage 42, the low-pressure inlet passage 42 may also be continuous with the sealing protrusion 41. That is, the low-pressure inlet passage 42 may also be formed such that, when viewed from above, a portion of the low-pressure inlet passage 42 is continuous with the sealing protrusion 41. As an example, the horizontal path 44b can be formed as a continuous line with the sealing protrusion 41. Alternatively, the annular path 43 can be formed as a continuous line with the sealing protrusion 41.

[0099] On the other hand, the lower surface of the main valve component 32a, or more precisely, the portion of the lower surface of the main valve component 32a that is further outward than the portion abutting against the main valve seat 17, faces the interior of the main valve chamber 13, where the fluid pressure is higher. Therefore, in the control valve of this embodiment, due to the pressure difference between the upper and lower surfaces of the main valve component 32a, when the valve is closed, an upward load (pressing the main valve component 32a against the lower surface of the flange portion 35b) is applied to the main valve component 32a, preventing the main valve component 32a from falling off even if the inner periphery of the main valve component 32a is not supported by the inner support portion. Furthermore, such an effect can be achieved as long as there is a sealing part 40a (sealing protrusion 41) on the outside of the main valve seat 17 (the part that the main valve core 45 abuts against). However, in this embodiment, the sealing part 40a (sealing protrusion 41) is located on the outside of the annular protrusion 61. Therefore, even if the main valve component 32a deforms due to years of use and the range of the main valve seat 17 expands, the sealing part 40a (sealing protrusion 41) is maintained on the outside of the main valve seat 17, and the above-mentioned effect can be reliably obtained.

[0100] Furthermore, in the first embodiment, the sealing portion 40 is formed on the inner periphery of the upper surface of the main valve component 32. When the valve is closed, the high fluid pressure in the main valve chamber 13 is applied to the upper surface of the main valve component 32. Therefore, an inner support portion 38 is provided to prevent the main valve component 32 from falling off. In contrast, according to this embodiment, by utilizing the functions of the sealing portion 40a and the low-pressure inlet 42 described above, the inner support portion can be omitted, thereby reducing the processing time during the manufacture of the control valve.

[0101] [Third Implementation Method]

[0102] based on Figures 7-11 The pilot-operated control valve according to the third embodiment of the present invention will be described.

[0103] In the first and second embodiments described above, the main valve components 32 and 32a and the valve port component 33 are separate (different components). However, in this embodiment, the main valve component (represented by the symbol 32) and the valve port component (represented by the symbol 33) are integrated (connected) components.

[0104] Specifically, in this embodiment, such as Figure 11 As shown, the main valve component 32 and the valve port component 33 are integrally formed by embedding and molding the inner shell component 35, and as... Figure 7 As shown, the main valve core 46 is housed together with the valve stem stop 36 in the housing component 34. Therefore, the inner housing component 35 is as follows: Figures 8-10 As shown, it has multiple (four in this embodiment) through holes 35c that extend through the flange portion 35b in the vertical direction, and the main valve component 32 and the valve port component 33 are connected to each other through these through holes 35c.

[0105] The advantages of this implementation are as follows.

[0106] The main valve component 32 and the valve port component 33 are rubber components, while the inner shell component 35 is a metal component. When these components (main valve component 32, valve port component 33, and inner shell component 35) are not integrally formed, strict management of the dimensional tolerances of each component is required since they need to be assembled. In contrast, according to this embodiment where these components are integrally formed, in order to embed them into the inner shell component 35, only rubber material needs to flow into the mold; therefore, the management of dimensional tolerances is alleviated, and the assemblability of the main valve core is improved.

[0107] [Fourth Implementation Method]

[0108] Figure 12 This refers to the main valve core of the pilot-operated control valve according to the fourth embodiment of the present invention.

[0109] As shown in the figure, the main valve core 47, like the main valve core 46 in the third embodiment described above, integrates the main valve component 32 and the valve port component 33 with the inner housing component 35 through an embedded molding process, and houses them inside the outer housing component 34 (the same applies to the fifth embodiment described later). However, in this embodiment, the valve shaft stop 36 is integrally formed with the outer housing component 34.

[0110] Furthermore, in this embodiment, the outer periphery of the main valve component 32 is riveted to the lower end of the housing component 34. That is, the lower end of the housing component 34 forms an inwardly bent protrusion (in the direction close to the central axis A) (this protrusion is called the "outer riveting part", denoted by the symbol 37a), thereby supporting the outer periphery of the main valve component 32 from the lower surface side. In addition, the inner periphery of the main valve component 32 is supported by the inner support part 38.

[0111] [Fifth Implementation Method]

[0112] Figure 13 This refers to the main valve core of the pilot-operated control valve according to the fifth embodiment of the present invention.

[0113] In the fourth embodiment, the outer riveting portion 37a (see reference 34) bends inward at the lower end of the outer casing component 34. Figure 12 The main valve component 32 is fixed by riveting the inner shell component 35 (the inner shell component 35 is fixed by the outer riveting part 37a).

[0114] Specifically, the flange portion 35b of the inner housing component 35 has an annular foot 35d, which extends vertically downward from the outer edge of the flange portion 35b in a manner that covers the outer peripheral surface of the main valve component 32 (in other words, in a manner that is between the outer housing component 34 and the main valve component 32). Furthermore, the foot 35d has an inwardly extending locking portion 35e at its lower end, which supports the main valve component 32 from below. Moreover, by bending the lower end of the outer housing component 34 inward to form an outer riveting portion 37a, the main valve component 32 is supported from below via the inner housing component 35 (locking portion 35e) through the outer riveting portion 37a, thus securing the main valve component 32.

[0115] The embodiments of the present invention have been described above, but the present invention is not limited thereto. Various modifications can be made within the scope of the claims, which will be obvious to those skilled in the art.

[0116] For example, in the above embodiment, an electromagnetic actuator (i.e., a solenoid valve) is used as the driving device, but the driving device can also be an electric motor, and the present invention can also be applied to electric valves. Furthermore, when applied to electric valves, it is sufficient to have a pilot valve core at the top of the lifting component (e.g., valve shaft, valve rod), which is a moving body that moves up and down using a lifting device with a threaded feed mechanism, to open and close the pilot passage.

Claims

1. A pilot-operated control valve, comprising: The valve body has a main valve chamber and a pilot valve chamber inside, and the valve body has an inflow passage for fluid to flow into the main valve chamber and an outflow passage for fluid to flow out of the main valve chamber, the end of the outflow passage on the main valve chamber side becoming the main valve port; The main valve core moves forward and backward relative to the main valve port; A pilot passage that extends through the main valve core and selectively connects the pilot valve chamber and the outflow path; A pressure equalization circuit, which connects the main valve chamber and the pilot valve chamber; A pilot valve port is formed at the end of the pilot passage on the pilot valve chamber side; A pilot valve shaft that opens and closes the pilot passage by moving forward and backward relative to the pilot valve port, and having a top portion that is inserted into the pilot valve port when the valve is closed; and A drive unit that drives the pilot valve shaft, Its features are, The pilot valve shaft, the main valve core, and the main valve port are arranged sequentially along an axial direction. When this axial direction is defined as the "up-down direction," the direction from the main valve core towards the pilot valve shaft is defined as "up," and the direction from the main valve core towards the main valve port is defined as "down,"... Within the valve body, a main valve seat is provided around the main valve port. The main valve seat is the part that the main valve core abuts against. The main valve core has: An annular main valve component, which is made of an elastic material, opens and closes the main valve port by contacting and separating from the main valve seat; An annular pilot valve port component, made of an elastic material, comprising the pilot valve port and contacting / separating from the pilot valve shaft; and The housing component is made of a material with higher rigidity than the main valve component and the pilot valve port component, and restricts the elastic deformation of the main valve component and the pilot valve port component. The shell component includes: Housing component that covers the main valve component and the pilot valve port component from the outer peripheral side; and An inner shell component, which is disposed inside the outer shell component. The inner shell component has: A cylindrical body having a central hole extending vertically and forming the pilot passage; and A plate-shaped flange portion that extends outward from the body section. The outer peripheral surface of the body abuts against the inner peripheral surface of the main valve component and the inner peripheral surface of the pilot valve port component. The upper surface of the flange abuts against the lower surface of the pilot valve port component, and the lower surface of the flange abuts against the upper surface of the main valve component.

2. The pilot-operated control valve according to claim 1, characterized in that, The main valve core also includes a valve shaft stop, which is made of a material with higher rigidity than the pilot valve port component and abuts against the pilot valve shaft when the valve is closed, thereby restricting the downward movement of the pilot valve shaft.

3. The pilot-operated control valve according to claim 2, characterized in that, The top end of the pilot valve shaft has an inverted conical or frustum-shaped shape. The valve shaft stop has a limiting hole that is inserted into the tip of the pilot valve shaft during valve closing, thereby abutting against the tip to limit further downward movement of the pilot valve shaft. The limiting orifice is positioned above the pilot valve port. The limiting hole has an inner diameter that is larger than the inner diameter of the pilot valve port and smaller than the maximum diameter of the top end of the pilot valve shaft.

4. The pilot-operated control valve according to claim 1, characterized in that, The elastic material constituting the main valve component and the pilot valve port component is rubber.

5. The pilot-operated control valve according to any one of claims 1 to 4, characterized in that, The main valve core has a sealing portion that, when the valve is closed, prevents fluid from flowing between the main valve chamber and the main valve port through the gap between the housing component and the main valve component. The sealing portion is formed at a position outside the main valve seat.

6. The pilot-operated control valve according to claim 5, characterized in that, The valve body has an annular protrusion, the interior of which forms the main valve port, and the protrusion protrudes upward relative to its surroundings. The protrusion has the main valve seat. The sealing portion is formed at a position further outward than the protrusion.

7. The pilot-operated control valve according to claim 5 or 6, characterized in that, It has a low-pressure inlet path, which forms at least a part of a flow path that, when the valve is closed, communicates with the main valve port to introduce the low pressure from the outlet side to the sealing part side of the main valve component, and from the outlet path to the sealing part.

8. The pilot-operated control valve according to claim 7, characterized in that, The low-pressure inlet path includes: A ring-shaped path extends circumferentially along the upper surface of the outer periphery of the main valve component; as well as A connecting path that connects the loop and the main valve port.

9. The pilot-operated control valve according to claim 8, characterized in that, The connecting path includes: One or more vertical paths extending vertically along the inner circumferential surface of the main valve component; and One or more horizontal paths extend radially from the upper end of the vertical path along the upper surface of the main valve component.

10. The pilot-operated control valve according to any one of claims 1 to 4, characterized in that, The flange portion has one or more through holes, which connect the upper space of the flange portion and the lower space of the flange portion. The main valve component and the pilot valve port component are integrally formed by a connecting part, which is made of the elastic material disposed in the through hole.

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