Solenoid valve and solenoid valve device

Abstract

A low-cost and highly reliable solenoid valve and solenoid valve device are provided. The solenoid valve includes a pilot valve core fixed to the main valve core side of the plunger and is an elastic body that opens and closes the pilot valve port according to the movement of the plunger. The pilot valve core is arranged radially inside the solenoid coil within the movement range of the plunger. The main valve core has a shaft portion that extends towards the plunger side along the movement direction of the plunger and forms the pilot passage inside. The shaft portion can abut against the pilot valve core.

Description

Technical Field

[0001] This invention relates to an electromagnetic valve. Background Technology

[0002] For example, Patent Document 1 discloses a solenoid valve having a pilot valve core and opening and closing the valve using the pressure difference between the two sides of the flow direction of the valve core. According to this prior art solenoid valve, when the plunger moves in one direction due to the energization of the solenoid coil, the pilot valve orifice of the valve core closes, causing the internal pressure of the pilot chamber to rise. The valve core then sits on the valve seat, preventing fluid flow from the high-pressure side to the low-pressure side. Furthermore, when the energization of the solenoid coil is stopped, the plunger moves in the other direction due to the force of the spring. The pilot valve orifice opens, and the fluid in the pilot chamber flows downstream through the pilot valve orifice. The internal pressure of the pilot chamber decreases, causing the valve core to leave the valve seat, and fluid flow from the high-pressure side to the low-pressure side resumes.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-31389

[0006] The technical problem that the invention aims to solve

[0007] Here, according to the solenoid valve of Patent Document 1, a pilot valve core capable of moving integrally with the plunger is configured to extend within the shaft of the suction member, and the pilot valve orifice of the valve core is blocked according to the action of the plunger. However, such a solenoid valve requires the shaft of the suction member to be machined into a slender shape, but the suction member is usually machined using an expensive magnetic material, thus presenting a technical problem of increased cutting amount and increased machining cost. Summary of the Invention

[0008] The present invention was made in view of the above-mentioned technical problems, and its object is to provide a low-cost and highly reliable solenoid valve.

[0009] Technical means for solving technical problems

[0010] The solenoid valve of the present invention comprises:

[0011] The valve body has a main valve chamber inside, and 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 valve body has a main valve port formed at the end of the outflow passage on the main valve chamber side.

[0012] A main valve core, which opens and closes the main valve port by moving forward and backward relative to the main valve port;

[0013] plunger;

[0014] An electromagnetic drive device includes an attraction element, a sleeve, and an electromagnetic coil. The attraction element is fixed to the valve body and attracts the plunger. The sleeve is fixed to the attraction element and houses the plunger so that it is movable. The electromagnetic coil is disposed around the sleeve. The electromagnetic drive device drives the plunger.

[0015] A pilot valve chamber is formed within the sleeve and between the plunger and the suction member;

[0016] A pilot passage that passes through the main valve core and connects the pilot valve chamber to the outflow path, wherein the pilot valve chamber side end of the pilot passage becomes the pilot valve port;

[0017] A pressure equalization circuit, which connects the main valve chamber to the pilot valve chamber; and

[0018] A pilot valve core, which is fixed to the main valve core side of the plunger, and is an elastic body that opens and closes the pilot valve port according to the movement of the plunger.

[0019] The pilot valve core is positioned radially inside the electromagnetic coil within the range of motion of the plunger.

[0020] The main valve core has a shaft that extends toward the plunger along the direction of movement of the plunger, and the pilot passage is formed inside the shaft.

[0021] The effects of the invention

[0022] According to the present invention, a low-cost and highly reliable solenoid valve can be provided. Attached Figure Description

[0023] Figure 1 This is a longitudinal sectional view of the solenoid valve (excluding the valve body) according to the first embodiment.

[0024] Figure 2 It is a magnified cross-sectional view showing the area near the lower end of the plunger of the solenoid valve.

[0025] Figure 3 It is a magnified cross-sectional view showing the area near the lower end of the plunger of the solenoid valve.

[0026] Figure 4 This is a cross-sectional view showing the area near the lower end of the plunger involved in the modified example 1 of the first embodiment.

[0027] Figure 5 This is a cross-sectional view showing the area near the lower end of the plunger in Modification 2 of the first embodiment.

[0028] Figure 6This is a cross-sectional view showing the area near the lower end of the plunger in Modification 3 of the first embodiment.

[0029] Figure 7 This is a cross-sectional view showing the area near the lower end of the plunger involved in Modification 4 of the first embodiment.

[0030] Figure 8 This is a cross-sectional view showing the area near the lower end of the main valve core involved in Modification 5 of the first embodiment.

[0031] Figure 9 This is a cross-sectional view showing the area near the lower end of the main valve core involved in Modification 6 of the first embodiment.

[0032] Figure 10 This is a longitudinal sectional view of the solenoid valve according to the second embodiment.

[0033] Figure 11 This is a longitudinal sectional view of the solenoid valve according to the third embodiment.

[0034] Figure 12 This is a longitudinal sectional view of the solenoid valve involved in a variation of the third embodiment.

[0035] Figure 13 This is a longitudinal sectional view of the solenoid valve according to the fourth embodiment.

[0036] Figure 14 This is a longitudinal sectional view of the main valve core.

[0037] Figure 15 It is Figure 13 The diagram shows an enlarged view of part C of the solenoid valve.

[0038] Figure 16 It is Figure 13 The diagram shows an enlarged view of part C of the solenoid valve.

[0039] Symbol Explanation

[0040] 1, 1G, 1H, 1I, 1J Solenoid valves; 10, 10G Valve body; 11, 11G Main body; 12 High-pressure flow path; 13 Low-pressure flow path; 13b Main valve seat; 40, 40H Suction element; 41 Base; 42 Cylinder; 50, 50A, 50B, 50C, 50D, 50H Pistons; 51 Pilot valve core; 60, 61 Helical springs; 70, 70F, 70H, 70I, 70J Main valve core; 80 Coil unit; 81 Solenoid coil; 83 Housing; PC Pilot valve chamber; LC Lower space; UC Upper space; VC Main valve chamber. Detailed Implementation

[0041] Hereinafter, with reference to the accompanying drawings, embodiments of a solenoid valve and solenoid valve device, which are a type of solenoid valve of the present invention, will be described. Furthermore, in this specification, the upper part will be referred to as the plunger (or coil) side relative to the suction member, and the lower part will be referred to as the suction member side relative to the plunger.

[0042] (First Implementation)

[0043] Figure 1 This is a longitudinal sectional view of the solenoid valve 1 according to the first embodiment. Figure 2 This is an enlarged cross-sectional view showing the lower end of the plunger of solenoid valve 1, indicating the closed state of the pilot valve port. Figure 3 This is a magnified cross-sectional view of the area near the lower end of the plunger of solenoid valve 1, showing the open state of the pilot valve port. The axis of solenoid valve 1 is set as L.

[0044] like Figure 1 As shown, the solenoid valve 1 has a valve body 10, a suction member 40, a plunger 50, a main valve core 70, and a coil unit 80. Furthermore, the electromagnetic drive device is composed of the suction member 40, the plunger 50 on which the pilot valve core 51 is mounted, the coil unit 80, and the sleeve component 44 described later.

[0045] The valve body 10 has a block-shaped main body portion 11. Within the main body portion 11, a high-pressure flow path (inflow path) 12 and a low-pressure flow path (outflow path) 13, as well as a circular opening portion 14, are formed intersecting the axis and arranged opposite to each other. The inner end of the high-pressure flow path 12, which is connected to a high-pressure pipe (not shown), communicates with the inner end of the circular opening portion 14. In addition, the inner side of the low-pressure flow path 13, which is connected to a low-pressure pipe (not shown), is bent into an L-shape, and its cylindrical end portion 13a protrudes coaxially with the circular opening portion 14 within the circular opening portion 14. The upper end of the cylindrical end portion 13a becomes the main valve seat 13b constituting the main valve port, and the area around the cylindrical end portion 13a forms the main valve chamber VC.

[0046] The mounting surface 11a, which forms the upper surface of the main body 11, is a plane orthogonal to the axis L, and the coil unit 80 is mounted thereon. On the mounting surface 11a, a circular opening 14 opens coaxially with the axis L.

[0047] An attraction member 40 is provided within the circular opening 14. The attraction member 40 is formed by coaxially connecting a disc-shaped base 41 and a cylindrical portion 42 with a smaller diameter than the base 41. The base 41 has a circular opening 41a formed at the center of its lower end. A through hole 41b is formed, which spans the base 41 and the cylindrical portion 42, communicates with the center of the opening 41a, and opens towards the upper end. The through hole 41b is formed by an upper hole 41c, a middle hole 41d connected to the lower end of the upper hole 41c and with a smaller diameter than the upper hole 41c, and a lower hole 41e connected to the lower end of the middle hole 41d and with a larger diameter than the middle hole 41d.

[0048] By screwing the external thread formed on the outer periphery of the base 41 into the internal thread formed on the inner periphery of the circular opening 14, the suction member 40 is fixed relative to the main body 11 of the valve body 10 while the lower outer periphery of the base 41 abuts against the inner peripheral stepped portion of the circular opening 14. At this time, an O-ring OR is disposed between the base 41 and the circular opening 14 to prevent fluid leakage through the gap between the base 41 and the circular opening 14.

[0049] With the base 41 installed in the circular opening 14, the cylindrical portion 42 faces upward and protrudes relative to the mounting surface 11a. At the upper end of the cylindrical portion 42, the lower end of a thin-walled, topped cylindrical sleeve component (sleeve) 44 is coaxially joined to the cylindrical portion 42 by welding or brazing. A hollow plunger 50 is disposed inside the sleeve component 44.

[0050] The plunger 50, having a bottomed cylindrical shape, includes: a first communicating hole 50a formed in the center of the bottom wall; a cylindrical recess 50b communicating with the lower end of the first communicating hole 50a; an annular retaining portion 50c protruding radially inward from the lower end of the cylindrical recess 50b; and a second communicating hole 50d formed near the upper end of the side wall of the plunger 50. A pilot valve core 51, made of rubber such as EPDM or HNBR, is disposed in the cylindrical recess 50b such that its upper end and outer periphery are in close contact with the inner surface of the cylindrical recess 50b. Preferably, the pilot valve core 51, disposed radially inward of the electromagnetic coil 81 of the coil unit 80, is positioned when the plunger 50 is at the upper end of its stroke (…). Figure 1 When it is located near the center of the axis of electromagnetic coil 81.

[0051] Assuming a plunger without the first connecting hole (connecting path) 50a is installed, when the pilot valve core 51 is installed in the cylindrical recess 50b, if refrigerant (fluid) accumulates between them, the refrigerant thermally expands as the temperature of the solenoid valve 1 rises, potentially squeezing the pilot valve core 51 out of the cylindrical recess 50b. To address this, by connecting the interior of the plunger 50 to the cylindrical recess 50b via the first connecting hole 50a, the thermally expanding refrigerant within the cylindrical recess 50b can escape into the interior of the plunger 50, eliminating the aforementioned problem. The second connecting hole 50d functions to ensure smooth movement of the plunger 50 by equalizing the pressure applied to both sides of the plunger 50 in the direction of movement.

[0052] When assembling the pilot valve core 51 onto the plunger 50, the pilot valve core 51 is elastically deformed to pass through the inner side of the annular retaining portion 50c. After passing through, it returns to its original position through elastic deformation, thereby allowing it to be tightly fitted within the cylindrical recess 50b. After assembly, the pilot valve core 51 is held by the annular retaining portion 50c to prevent it from falling off, and the plunger 50 and the pilot valve core 51 are integrated.

[0053] The main valve core 70 has a valve shaft 71 and an outer cylindrical portion 73 and an inner cylindrical portion 74 mounted on the lower end of the valve shaft 71.

[0054] The valve shaft 71, which serves as the shaft portion, is made of metal and is formed by sequentially connecting a first cylindrical portion 71a, a second cylindrical portion 71b with a larger diameter than the first cylindrical portion 71a, a flange portion 71c with a larger diameter than the second cylindrical portion 71b, and a third cylindrical portion 71d with approximately the same diameter as the second cylindrical portion 71b from the top end side. The outer diameter of the third cylindrical portion 71d is smaller than the inner diameter of the main valve seat 13b. An external thread 71e is formed on the outer circumference of the third cylindrical portion 71d. In addition, the valve shaft 71 has a pilot passage 71f that extends in the vertical direction. The upper end of the first cylindrical portion 71a, through which the pilot passage 71f passes, constitutes a pilot valve port.

[0055] like Figure 3 As shown, the outer diameter of the first cylindrical portion 71a is smaller than the inner diameter of the annular retaining portion 50c, and the length A of the first cylindrical portion 71a is a specified amount larger than the thickness (length in the axial direction L) B of the annular retaining portion 50c.

[0056] exist Figure 1 In the inner cylindrical portion 74, a rubber ring-shaped component has a downward-facing outer peripheral step. Conversely, the outer cylindrical portion 73 is a metal ring-shaped component longer than the inner cylindrical portion 74 in the axial direction, and has an upward-facing inner peripheral step. Furthermore, the outer cylindrical portion 73 has a pressure equalization passage 73a extending vertically and a riveted portion 73b protruding from its upper inner peripheral edge. The main valve chamber VC is connected to the upper space UC above both the outer cylindrical portion 73 and the inner cylindrical portion 74 via the pressure equalization passage 73a.

[0057] When assembling the main valve core 70, firstly, when the external thread 71e on the lower end side of the valve shaft 71 is screwed into the inner cylindrical portion 74, an internal thread is formed on the inner circumference of the inner cylindrical portion 74 corresponding to the external thread 71e. The valve shaft 71 and the inner cylindrical portion 74 become one unit through the engagement of the threads. However, the internal thread can also be pre-formed on the inner circumference of the inner cylindrical portion 74.

[0058] Next, the valve shaft 71 and the inner cylindrical portion 74 are fitted into the outer cylindrical portion 73. The riveted portion 73b, which was thin-walled and cylindrical before assembly, is bent radially inward to plastically deform it, so as to retain the upper surface of the flange portion 71c of the valve shaft 71. Thus, the main valve core 70 is integrally formed.

[0059] The pressure equalization passage 73a extends through the upper and lower end faces of the outer cylindrical portion 73 and also opens on the inner circumferential side of the outer cylindrical portion 73. This is to allow the refrigerant accumulated between the inner cylindrical portion 74 and the outer cylindrical portion 73 to be discharged through the pressure equalization passage 73a. If refrigerant accumulates between the inner cylindrical portion 74 and the outer cylindrical portion 73, the refrigerant will thermally expand when the temperature of the solenoid valve 1 rises, which may cause adverse conditions such as the inner cylindrical portion 74 being squeezed out of the outer cylindrical portion 73. However, by connecting the pressure equalization passage 73a to the inner circumferential side of the outer cylindrical portion 73, this adverse condition can be suppressed.

[0060] Relative to the base 41 of the suction member 40, the main valve core 70 is subjected to force by the lower spring 75 toward the plunger 50.

[0061] A helical spring 60 is disposed between the stepped portion between the upper hole 41c and the middle hole 41d of the suction member 40 and the lower surface of the bottom wall of the plunger 50. This helical spring 60 exerts an upward force on the plunger 50 relative to the suction member 40. The lower end of the plunger 50 has a tapered shape that narrows downwards, and the upper end of the cylindrical portion 42 of the suction member 40 has a complementary tapered shape. Inside the sleeve member 44, the space between the plunger 50 and the suction member 40 is referred to as the pilot valve chamber PC. The pilot valve chamber PC communicates with the upper space UC within the opening 41a via the gap between the valve shaft 71 and the through hole 41b (referred to as the equalizing line CP).

[0062] The coil unit 80 has: a hollow cylindrical electromagnetic coil (coil) 81, a winding frame 82 on which the electromagnetic coil 81 is wound, and a housing 83 holding the winding frame 82, and is molded in resin.

[0063] (Action of the solenoid valve)

[0064] When the electromagnetic coil 81 is powered by a power source not shown in the diagram, the magnetic field generated by the electromagnetic coil 81 creates a magnetic circuit passing through the plunger 50, the attraction element 40, and the housing 83, generating a magnetic force that overcomes the force of the coil spring 60 and presses the plunger 50 down. When the plunger 50 is pressed down, the pilot valve core 51 also descends, as... Figure 2 As shown, its lower surface abuts against the upper end of the first cylindrical portion 71a of the valve shaft 71. Thus, when the pilot passage 71f is blocked, the main valve core 70 is pressed down, and the main valve seat 13b is shielded by the inner cylindrical portion 74.

[0065] At this time, as Figure 2As shown, the stepped portions (abutment portions AP) of the first cylindrical portion 71a and the second cylindrical portion 71b of the valve shaft 71 abut against the lower surface of the plunger 50, thereby suppressing excessive increase in surface pressure between the first cylindrical portion 71a and the lower surface of the pilot valve core 51, and suppressing the offset of the pilot valve core 51. Specifically, a predetermined amount, which is the difference between the length A of the first cylindrical portion 71a and the thickness B of the annular retaining portion 50c, is an amount that can prevent fluid leakage from the pilot valve core 51 and suppress offset during long-term use. This predetermined amount varies, for example, depending on the material of the pilot valve core 51.

[0066] When the pilot passage 71f is blocked, the pressure in the upper space UC above the outer cylindrical portion 73, which is connected to the high-pressure flow path 12 via the equalizing passage 73a, becomes greater than the internal pressure (pressure in the lower space LC) of the cylindrical end 13a, which is connected to the low-pressure flow path 13. Therefore, the main valve core 70 is maintained in the main valve seat 13b by overcoming the force of the lower spring 75, and the flow of fluid from the high-pressure flow path 12 to the low-pressure flow path 13 is cut off.

[0067] In response, if the power supply to the electromagnetic coil 81 from the unillustrated power source is interrupted, the magnetic force that presses down the plunger 50 disappears, and the plunger 50 is pushed upward by the force of the helical spring 60, thus... Figure 3 As shown, the pilot valve core 51 rises and moves away from the first cylindrical portion 71a of the valve shaft 71, opening the pilot passage 71f. Consequently, fluid flows from the pilot valve chamber PC to the low-pressure flow path 13 via the pilot passage 71f. The pressure difference between the upper space UC (equal to the pilot valve chamber PC) and the lower space LC (more precisely, the pressure difference between the portion projected onto the upper space UC from the outer periphery of the cylindrical end 13a) approaches zero. More specifically, the pressure in the upper space UC becomes approximately the same as the pressure in the lower space LC. Furthermore, the pressure in the upper space UC becomes less than the pressure in the main valve chamber VC, thus causing the main valve core 70 to rise. This creates a gap between the inner cylindrical portion 74 and the main valve seat 13b, allowing fluid to flow from the high-pressure flow path 12 through the main valve chamber VC, via the cylindrical end 13a, to the low-pressure flow path 13. Furthermore, the outer circumferential space of the cylindrical end 13a is closer to the pressure of the high-pressure flow path 12 than to the low-pressure flow path 13, while the inner circumferential space of the cylindrical end 13a and the pilot valve chamber PC are closer to the pressure of the low-pressure flow path 13 than to the high-pressure flow path 12.

[0068] According to one type of existing solenoid valve, a pilot valve core is provided that extends from the lower end of the plunger through an attraction element, and a pilot valve port plug blocks the annular main valve core according to the actuation of the plunger. However, such a solenoid valve requires that the cylindrical portion of the attraction element be relatively long, but there is a technical problem of high processing cost when the attraction element, which is usually formed as a magnetic body, is formed by machining.

[0069] In this embodiment, the valve shaft 71 of the main valve core 70 extends toward the plunger 50 side, so that it can closely abut against the pilot valve core 51 on the outer side of the cylindrical portion 42 of the suction member 40 in the axial direction, thereby blocking the pilot passage 71f. Therefore, the axial length of the cylindrical portion 42 can be reduced to a shorter length, thereby reducing the processing cost.

[0070] Furthermore, by making the pilot valve core 51, which is mounted on the plunger 50, a low Young's modulus rubber material, fluid leakage can be effectively suppressed even when the pressure difference between the two sides of the main valve core 70 in the direction of movement is small and the pressing force of the main valve core 70 on the pilot valve core 51 is relatively low. Moreover, since the pilot valve core 51 is located radially inside the solenoid coil 81, the pilot valve core 51 is heated by heat conduction from the solenoid coil 81 when powered on. Therefore, even when a low-temperature refrigerant is supplied to the pilot valve chamber PC, the pilot valve core 51 can have sufficient flexibility to prevent fluid leakage when the valve is closed.

[0071] (Modification 1 of the first embodiment)

[0072] Figure 4 This is a cross-sectional view showing the area near the lower end of the plunger 50A according to Variation 1 of the first embodiment. In this variation, only the shape of the lower end of the plunger 50A differs from that of the first embodiment; the rest of the structure is the same as that of the first embodiment, so repeated descriptions are omitted.

[0073] In this modified example, the plunger 50A does not have an annular retaining portion, and the cylindrical recess 50b is open at the lower end of the plunger 50A. The pilot valve core 51 is mounted to the cylindrical recess 50b by vulcanization bonding. Furthermore, when the pilot valve core 51 and the cylindrical recess 50b are completely tightly attached by vulcanization bonding, refrigerant can be prevented from entering between the pilot valve core 51 and the cylindrical recess 50b, so the first connecting hole 50a can be omitted. In addition, although the coil spring 60 abuts against the lower surface of the pilot valve core 51, it can also abut against the lower surface of the plunger 50A.

[0074] (Modification 2 of the first embodiment)

[0075] Figure 5 This is a cross-sectional view showing the area near the lower end of the plunger 50B in Modification 2 of the first embodiment. In this modification, only the shape of the lower end of the plunger 50B differs from that of the first embodiment; the rest of the structure is the same as that of the first embodiment, so repeated descriptions are omitted.

[0076] In this modified example, the plunger 50B does not have an annular retaining portion. Instead, an annular member 52 is provided that fits into the inner circumference of the cylindrical recess 50b. A pilot valve core 51 is provided in the cylindrical recess 50b, and the annular member 52 is installed in the cylindrical recess 50b by pressing it in such a way that it is located below the pilot valve core 51. The inner diameter of the annular member 52 is larger than the outer diameter of the first cylindrical portion 71a, so that the contact between the valve shaft 71 and the pilot valve core 51 does not obstruct the annular member 52. The length of the first cylindrical portion 71a is a predetermined amount larger than the thickness of the annular member 52.

[0077] (Modification 3 of the first embodiment)

[0078] Figure 6 This is a cross-sectional view showing the area near the lower end of the plunger 50C in Modification 3 of the first embodiment. In this modification, only the shape of the lower end of the plunger 50C differs from that of the first embodiment; the rest of the structure is the same as that of the first embodiment, so repeated descriptions are omitted.

[0079] In this modified example, the plunger 50C does not have an annular retaining portion; instead, it has a riveted retaining portion 50Cc protruding from the lower end of the plunger 50C. After the pilot valve core 51 is assembled into the cylindrical recess 50b, the riveted retaining portion 50Cc, which was thin-walled and cylindrical before assembly, is bent radially inward to plastically deform it, thereby retaining the lower surface of the pilot valve core 51 and preventing it from falling off.

[0080] (Modification 4 of the first embodiment)

[0081] Figure 7 This is a cross-sectional view showing the area near the lower end of the plunger 50D in Modification 4 of the first embodiment. In this modification, only the shape of the lower end of the plunger 50D differs from the first embodiment; the rest of the structure is different, so repeated descriptions are omitted.

[0082] In this modified example, the plunger 50D does not have an annular retaining portion; instead, it has riveting claw portions 50Dc protruding from the lower end of the plunger 50C. Multiple riveting claw portions 50Dc extend downward from the lower end of the plunger 50D at equal intervals in the circumferential direction. After the pilot valve core 51 is assembled into the cylindrical recess 50b, each riveting claw portion 50Dc is bent radially inward to plastically deform it, thereby retaining the lower surface of the pilot valve core 51 and preventing it from falling off.

[0083] (Modification 5 of the first embodiment)

[0084] Figure 8This is a cross-sectional view showing the area near the lower end of the main valve core 70E in Modification 5 of the first embodiment. In this modification, only the structure of the valve shaft 71E differs from that of the first embodiment; the rest of the structure is the same as that of the first embodiment, so repeated descriptions are omitted.

[0085] In this modified example, the valve shaft 71E does not have an external thread in the third cylindrical portion 71Ed, but has a cylindrical outer periphery. The structure otherwise is the same as in the first embodiment. The inner cylindrical portion 74 is attached to the third cylindrical portion 71Ed by vulcanization bonding.

[0086] (Modification 6 of the first embodiment)

[0087] Figure 9 This is a cross-sectional view showing the area near the lower end of the main valve core 70F in Modification 6 of the first embodiment. In this modification, only the structure of the valve shaft 71F differs from that of the first embodiment; the rest of the structure is the same as that of the first embodiment, so repeated descriptions are omitted.

[0088] In this modified example, the valve shaft 71F replaces the third cylindrical portion and has a riveted lower end portion 71Fd, which is tapered and expands in diameter downwards. The riveted lower end portion 71Fd does not have external threads. The structure is otherwise the same as in the first embodiment. After the inner cylindrical portion 74 is fitted around the pre-assembly cylindrical riveted lower end portion 71Fd, the riveted lower end portion 71Fd is plastically deformed in a tapered manner to prevent the inner cylindrical portion 74 from falling off. At this time, the inner cylindrical portion 74 elastically deforms according to the deformation of the riveted lower end portion 71Fd. Since the outer diameter of the deformed riveted lower end portion 71Fd is smaller than the inner diameter of the main valve seat 13b, the inner cylindrical portion 74 can abut against the main valve seat 13b.

[0089] (Second Implementation)

[0090] Figure 10 This is a longitudinal sectional view of the solenoid valve 1G according to the second embodiment. Compared with the first embodiment, this embodiment differs only in the structure of the main body 11G of the valve body 10G; the rest of the structure is the same as that of the first embodiment, so the same symbols are used and the description is omitted.

[0091] In this embodiment, the solenoid valve 1G is a so-called box-type valve, and the valve body 10G, suction member 40, plunger 50, main valve core 70, and coil unit 80 can be integrally mounted on the opposite-side structure ST. The solenoid valve 1G and the opposite-side structure ST constitute a solenoid valve device.

[0092] The cylindrical main body 11G has a large cylindrical portion 11Ga, a small cylindrical portion 11Gb with a smaller diameter than the large cylindrical portion 11Ga, an intermediate wall portion 11Gc coaxially connecting the lower end of the large cylindrical portion 11Ga and the upper end of the small cylindrical portion 11Gb, and a cylindrical end portion 13Ga extending from the intermediate wall portion 11Gc toward the main valve core 70. The upper end of the cylindrical end portion 13Ga forms a valve seat 13Gb, and the inner side of the cylindrical end portion 13Ga forms a lower space LC.

[0093] The suction member 40 is mounted to the main body 11G by engaging the external thread formed on the base 41 of the suction member 40 with the internal thread formed on the inner circumference near the upper end of the large cylindrical portion 11Ga. At this time, the inner circumference of the large cylindrical portion 11Ga and the outer circumference of the base 41 are sealed by an O-ring OR.

[0094] A peripheral groove 11Gd and an external thread 11Ge are formed on the outer periphery of the larger cylindrical portion 11Ga. A first O-ring OR1 is disposed in the peripheral groove 11Gd. Additionally, a lower peripheral groove 11Gf is formed on the outer periphery of the smaller cylindrical portion 11Gb. A second O-ring OR2 is disposed in the lower peripheral groove 11Gf.

[0095] A high-pressure flow path and a low-pressure flow path are formed in the mounting hole of the opposite-side structure ST. By engaging the main body 11G of the solenoid valve 1G with the mounting hole of the opposite-side structure ST, the external thread 11Ge engages with the internal thread formed on the inner circumference of the mounting hole, thereby allowing the main body 11G to be positioned in the mounting hole. At this time, by contacting the first O-ring OR1 and the second O-ring OR2 with the inner circumference of the mounting hole, the high-pressure flow path and the low-pressure flow path are separated in a way that prevents fluid from passing through, and refrigerant leakage from the gap between the mounting hole and the main body 11G is prevented.

[0096] The high-pressure flow path STa of the opposite structure ST communicates with the internal space (main valve chamber VC) of the large cylindrical section 11Ga via multiple (e.g., six) transverse holes (forming part of the high-pressure flow path) 11Gg formed in the large cylindrical section 11Ga. Furthermore, the internal space of the large cylindrical section 11Ga communicates with the low-pressure flow path STb of the opposite structure ST via the small cylindrical section 11Gb and the discharge path 13Gc (forming part of the low-pressure flow path) formed inside the cylindrical end section 13Ga.

[0097] In this embodiment, when the main valve core 70 descends as power is supplied to the solenoid coil 81, the valve seat 13Gb is blocked, thus cutting off the flow of fluid from the high-pressure flow path to the low-pressure flow path.

[0098] In response, when power is stopped to the solenoid coil 81, the main valve core 70 rises and the valve seat 13Gb opens, thus allowing fluid to flow from the high-pressure flow path through the transverse hole 11Gg, the main valve chamber VC, and the discharge path 13Gc to the low-pressure flow path.

[0099] (Third implementation method)

[0100] Figure 11 This is a longitudinal sectional view of the solenoid valve 1H according to the third embodiment. Compared with the first embodiment, this embodiment mainly differs in the structure of the suction member 40H, the plunger 50H, and the main valve core 70H. Other than that, the structure is the same as the first embodiment, so the same symbols are used and repeated descriptions are omitted.

[0101] The through hole 41Hb of the suction member 40H is composed of an upper hole 41Hc, a middle hole 41Hd connected to the lower end of the upper hole 41Hc and having a smaller diameter than the upper hole 41Hc, a fine hole 41Hg connected to the lower end of the middle hole 41Hd and having a smaller diameter than the middle hole 41Hd, and a lower hole 41He connected to the lower end of the fine hole 41Hg. The structure is otherwise the same as in the first embodiment.

[0102] Compared to the first embodiment, the plunger 50H differs only in that a circular tube portion 50He is formed at its lower end. Furthermore, the pilot valve core 51 disposed in the cylindrical recess 50b is held by an annular member 52, but this is not a limitation, and the structure of the first embodiment or its variations 1, 3, 4, etc., can be applied.

[0103] As a shaft portion, the main valve core 70H has an upper valve shaft (first valve shaft) 76H and a lower valve shaft (second valve shaft) 77H. The upper valve shaft 76H is formed by sequentially connecting a tapered portion 76Ha, a middle cylindrical portion 76Hb, and a lower cylindrical portion (protrusion) 76Hc, which has a larger diameter than the middle cylindrical portion 76Hb, from the upper end side, and also has an upper through hole 76Hd that extends through the upper valve shaft 76H in the vertical direction. An internal thread 76He is formed on the inner circumference of the lower cylindrical portion 76Hc.

[0104] The lower valve shaft 77H is formed by sequentially connecting a first cylindrical portion 77Ha (whose diameter is smaller than the inner diameter of the lower cylindrical portion 76Hc), a second cylindrical portion 77Hb (whose diameter is larger than the inner diameter of both the first and lower cylindrical portions 77Ha and 76Hc), a flange portion 77Hc (whose diameter is larger than the second cylindrical portion 77Hb), and a third cylindrical portion 77Hd from the upper end side. An external thread 77He is formed on the outer periphery of the first cylindrical portion 77Ha. The lower valve shaft 77H has a lower through hole 77Hf that extends vertically. A pilot passage is formed by the upper through hole 76Hd and the lower through hole 77Hf.

[0105] The upper valve shaft 76H is coaxially mounted on the upper end of the lower valve shaft 77H by screwing the external thread 77He of the first cylindrical portion 77Ha into the internal thread 76He of the lower cylindrical portion 76Hc. Furthermore, a helical spring (first spring) 60 is disposed between the stepped portion between the upper hole 41Hc and the middle hole 41Hd of the suction member 40H and the plunger 50H, applying an upward force to the plunger 50H relative to the suction member 40H. Moreover, a helical spring (second spring) 61 is disposed between the stepped portion between the middle hole 41Hd and the fine hole 41Hg of the suction member 40H and the lower end of the upper valve shaft 76H, applying an upward force to the upper valve shaft 76H (i.e., the main valve core 70H) relative to the suction member 40H. The outer diameters of the helical springs 60 and 61 are approximately equal from the upper end to the lower end. By providing a helical spring 61, the conical lower spring 75 and its retaining structure used in the first embodiment can be omitted, which helps to reduce costs.

[0106] The spring force of the helical spring 60 is set to a value that allows the plunger 50H to return to the upper end of its stroke when no power is supplied to the solenoid coil 81. Furthermore, the spring force of the helical spring 61 is set to exceed the downward force exerted on the main valve core 70H due to the vertical pressure difference experienced by the main valve core 70H. According to this embodiment, since the helical springs 60 and 61 are configured independently, there is an advantage in simplifying the design of the helical springs.

[0107] (A variation of the third embodiment)

[0108] Figure 12 This is a longitudinal sectional view of the solenoid valve 1I according to a variation of the third embodiment. Compared to the third embodiment, this embodiment differs mainly in the structure of the main valve core 70I; otherwise, the structure is the same as that of the third embodiment, so the same symbols are used and repeated descriptions are omitted.

[0109] The main valve core 70I differs from the third embodiment only in its valve shaft 71I; otherwise, its structure is the same as the third embodiment. The valve shaft 71I, serving as the shaft portion, is formed by sequentially connecting a tapered portion 71Ia, a second cylindrical portion 71Ib, a flange portion 71Ic with a diameter larger than the second cylindrical portion 71Ib, and a third cylindrical portion 71Id with a diameter approximately the same as the second cylindrical portion 71Ib, from the upper end side. Furthermore, the valve shaft 71 has a pilot passage 71If extending through the vertical direction.

[0110] Furthermore, a peripheral groove 71Ig is formed in the second cylindrical portion 71Ib, and a C-shaped clip (protrusion forming component) 78 is installed in the peripheral groove 71Ig.

[0111] A helical spring 60 is disposed between the stepped portion between the upper hole 41Hc and the middle hole 41Hd of the suction member 40H and the plunger 50H. Relative to the suction member 40H, the helical spring 60 exerts an upward force on the plunger 50H. Furthermore, a helical spring 61 is disposed between the stepped portion between the middle hole 41Hd and the fine hole 41Hg of the suction member 40H and the lower surface of the clamp 78. Relative to the suction member 40H, the helical spring 61 exerts an upward force on the valve shaft 71I (main valve core 70I).

[0112] Since the helical springs 60 and 61 are configured independently in the same way as in the third embodiment, the design of the helical springs becomes easier.

[0113] The third embodiment shows an example with two valve shafts. As another example, there may be three or more valve shafts, one of which may have a protrusion.

[0114] Furthermore, clip 78 is an example of a protrusion-forming component. One example is a structure in which a groove is formed in the shaft portion and the clip is fixed to that groove; alternatively, fixing can be achieved without a groove, such as through fitting. Furthermore, the groove is not limited to being circumferentially longer (circumferentially longer than the axial length). Other examples include grooves or recesses that are axially longer in the shaft portion.

[0115] The third embodiment and its variations described above are examples of the fourth type of invention. As other examples, the shaft portion may be a single unit and the protrusion may be integral (meaning they are not separate components). The protrusion can be any shape capable of supporting the second spring, such as a continuous ring in the circumferential direction, or a discontinuous shape in the circumferential direction, such as a C-shape.

[0116] (Fourth Implementation)

[0117] Figure 13 This is a longitudinal sectional view of the solenoid valve 1J according to the fourth embodiment. Figure 14 This is a longitudinal sectional view of the main valve core 70J. Figure 15 It is Figure 13 The enlarged diagram of part C of solenoid valve 1J shows the closed state of the pilot valve port. Figure 16 It is Figure 13 The enlarged diagram of part C of the solenoid valve 1J shows the open state of the pilot valve port.

[0118] Compared to the first embodiment, this embodiment differs mainly in the structure of the main valve core 70J. Although the valve body 10, plunger 50, suction member 40, coil unit 80, etc., are slightly different in shape from those in the first embodiment, their functions are the same. Therefore, they are marked with the same symbols and repeated descriptions are omitted. In addition, the structure of other components is the same as that of the first embodiment, so they are marked with the same symbols and repeated descriptions are omitted.

[0119] Furthermore, the pilot valve core 51 disposed in the cylindrical recess 50b of the plunger 50 is held by an annular member 52 that is pressed into the plunger 50 by a riveting part 54 or fixed by riveting, but is not limited thereto, and the structure of the first embodiment or its variations 1, 3, 4, etc. can be applied. The housing 83 of the coil unit 80 is fastened to the main body 11 of the valve body 10 by screws SC.

[0120] The main valve core 70J has a valve core base 71J and a cylindrical portion 74J installed at the lower end of the valve core base 71J.

[0121] exist Figure 14 In this design, the valve core base 71J is made of metal and is formed by sequentially connecting a first cylindrical portion 71Ja, a second cylindrical portion 71Jb with a diameter larger than the first cylindrical portion 71Ja, a central cylindrical portion 71Jc with a diameter larger than the second cylindrical portion 71Jb, a third cylindrical portion 71Jd with a diameter smaller than the central cylindrical portion 71Jc, and a lower cylindrical portion 71Je with a diameter larger than the third cylindrical portion 71Jd, from the upper end side. The valve core base 71J has a pilot passage 71Jf that extends vertically, and a pressure equalization passage 71Jg is located in the central cylindrical portion 71Jc. This pressure equalization passage 71Jg is parallel to and extends vertically through the pilot passage 71Jf.

[0122] The upper surface of the central cylindrical portion 71Jc is recessed in the center, and the space between the central cylindrical portion 71Jc and the bottom plane of the opening 41a of the suction member 40 forms the upper space UC. Figure 13 The upper space UC is connected to the space sandwiched between the central cylindrical portion 71Jc and the lower cylindrical portion 71Je (i.e., the main valve chamber VC around the cylindrical end 13a) via the pressure equalization passage 71Jg. In addition, the pilot valve chamber PC between the plunger 50 and the main valve core 70J is connected to the upper space UC via the gap between the second cylindrical portion 71Jb and the cylindrical portion 42.

[0123] A peripheral groove 71Jh is formed on the outer periphery of the central cylindrical portion 71Jc, and a sealing member SL is disposed in the peripheral groove 71Jh. The sealing member SL seals the outer periphery of the central cylindrical portion 71Jc with the inner periphery of the opening 41a. A lower spring 75 is disposed between the stepped portion on the lower outer periphery of the central cylindrical portion 71Jc and the valve body 10. The lower spring 75 applies force to the main valve core 70J toward the plunger 50.

[0124] A cylindrical recess 71Jk is formed on the lower surface of the lower cylindrical portion 71Je, and a cylindrical tube portion 71Ji is formed in the center of the recess 71Jk. A pilot passage 71Jf passes through the center of the recess 71Jk.

[0125] A rubber cylindrical part 74J is installed in the annular space between the inner circumference of the recess 71Jk and the outer circumference of the cylindrical part 71Ji.

[0126] After assembling the cylindrical portion 74J into the recess 71Jk, the washer 79 is engaged with the cylindrical portion 71Ji by riveting, for example, to prevent the cylindrical portion 74J from falling off. Furthermore, by plastically deforming the lower end of the recess 71Jk radially inward from its outer periphery, the inner edge of the deformed portion is hooked onto the outer peripheral step portion of the cylindrical portion 74J, thereby preventing the cylindrical portion 74J from falling off.

[0127] In this embodiment, as the plunger 50 descends with the supply of power to the electromagnetic coil 81, such as Figure 15 As shown, the upper end of the first cylindrical portion 71Ja abuts against the lower surface of the pilot valve core 51. When the pilot passage 71Jf is blocked, the main valve core 70J is pressed down, and the main valve seat 13b is covered by the inner cylindrical portion 74J. Therefore, the flow of fluid from the high-pressure flow path to the low-pressure flow path is cut off.

[0128] In response, when the plunger 50 rises as the power supply to the electromagnetic coil 81 is stopped, as... Figure 16 As shown, the pilot passage 71Jf is open, so the fluid flows from the pilot valve chamber PC to the low-pressure flow path 13. Due to the pressure difference between the upper space UC and the lower space LC, the main valve core 70J rises, thereby the fluid flows from the high-pressure flow path 12 to the low-pressure flow path 13.

[0129] Furthermore, solenoid valves include normally closed types that close when no solenoid coil is energized and open when the solenoid coil is energized, and normally open types that open when no solenoid coil is energized and close when the solenoid coil is energized. However, the solenoid valve of the present invention can be applied to any type.

[0130] Furthermore, the present invention is not limited to the embodiments described above. Within the scope of the present invention, any modifications to the constituent elements of the embodiments described above are possible.

[0131] This specification contains disclosures of the following inventions.

[0132] (First method)

[0133] A solenoid valve, comprising:

[0134] The valve body has a main valve chamber inside, and 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 valve body has a main valve port formed at the end of the outflow passage on the main valve chamber side.

[0135] A main valve core, which opens and closes the main valve port by moving forward and backward relative to the main valve port;

[0136] plunger;

[0137] An electromagnetic drive device includes an attraction element, a sleeve, and an electromagnetic coil. The attraction element is fixed to the valve body and attracts the plunger. The sleeve is fixed to the attraction element and houses the plunger so that it is movable. The electromagnetic coil is disposed around the sleeve. The electromagnetic drive device drives the plunger.

[0138] A pilot valve chamber is formed within the sleeve and between the plunger and the suction member;

[0139] A pilot passage that passes through the main valve core and connects the pilot valve chamber to the outflow path, wherein the pilot valve chamber side end of the pilot passage becomes the pilot valve port;

[0140] A pressure equalization circuit, which connects the main valve chamber to the pilot valve chamber; and

[0141] A pilot valve core, which is fixed to the main valve core side of the plunger, and is an elastic body that opens and closes the pilot valve port according to the movement of the plunger.

[0142] The pilot valve core is positioned radially inside the electromagnetic coil within the range of motion of the plunger.

[0143] The main valve core has a shaft that extends toward the plunger along the direction of movement of the plunger, and the pilot passage is formed inside the shaft.

[0144] (Second method)

[0145] The first type of solenoid valve, wherein...

[0146] The shaft portion has an abutting portion. When the end of the shaft portion on the pilot valve core side abuts against the pilot valve core, the abutting portion prevents the main valve core from moving further toward the pilot valve core side by abutting against the plunger.

[0147] (Third method)

[0148] A solenoid valve of the first or second type, wherein it has:

[0149] A first spring, relative to the suction member, applies a force to the plunger toward the side away from the suction member; and

[0150] The second spring, relative to the suction element, applies force to the main valve core toward the plunger side.

[0151] (Fourth method)

[0152] The third type of solenoid valve, wherein...

[0153] The outer peripheral surface of the shaft portion has a protrusion.

[0154] The second spring applies force to the protrusion toward the plunger side.

[0155] (Fifth method)

[0156] The third type of solenoid valve, wherein...

[0157] The shaft portion is configured to have multiple valve shafts fixed in place.

[0158] One of the plurality of valve shafts has the protrusion.

[0159] (Sixth method)

[0160] A solenoid valve according to any one of the methods from the first to the fifth, wherein...

[0161] A protrusion forming component is fixed to the shaft portion, and this protrusion forming component is a component different from the shaft portion.

[0162] The protrusion forming component forms the protrusion.

[0163] (Seventh method)

[0164] A solenoid valve according to any one of the methods from the first to the sixth, wherein...

[0165] The plunger is hollow, and a recess for holding the pilot valve core is formed on the suction side of the plunger. The interior of the recess is connected to the interior of the plunger via a connecting passage.

[0166] (Eighth Method)

[0167] A solenoid valve according to any one of the methods from the first to the seventh, wherein...

[0168] The solenoid valve is fixed to the structure in a detachable manner.

[0169] The construct has:

[0170] A mounting hole is provided for the valve body to be inserted in a removable manner;

[0171] High-pressure flow path, the high-pressure flow path being described in the mounting hole opening; and

[0172] The low-pressure flow path is located at the opening of the mounting hole.

[0173] With the valve body positioned in the mounting hole,

[0174] The inflow path is connected to the high-pressure flow path.

[0175] The outflow path is connected to the low-pressure flow path.

[0176] (Ninth Method)

[0177] A solenoid valve device comprising:

[0178] Solenoid valves of any one of the methods from the first to the eighth; and

[0179] Construct,

[0180] The construct has:

[0181] A mounting hole is provided for the valve body to be inserted in a removable manner;

[0182] High-pressure flow path, the high-pressure flow path being described in the mounting hole opening; and

[0183] The low-pressure flow path is located at the opening of the mounting hole.

[0184] With the valve body positioned in the mounting hole,

[0185] The inflow path is connected to the high-pressure flow path.

[0186] The outflow path is connected to the low-pressure flow path.

Claims

1. A solenoid valve, characterized in that, have: The valve body has a main valve chamber inside, and 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 valve body has a main valve port formed at the end of the outflow passage on the main valve chamber side. A main valve core, which opens and closes the main valve port by moving forward and backward relative to the main valve port; plunger; An electromagnetic drive device includes an attraction element, a sleeve, and an electromagnetic coil. The attraction element is fixed to the valve body and attracts the plunger. The sleeve is fixed to the attraction element and houses the plunger so that it is movable. The electromagnetic coil is disposed around the sleeve. The electromagnetic drive device drives the plunger. A pilot valve chamber is formed within the sleeve and between the plunger and the suction member; A pilot passage that passes through the main valve core and connects the pilot valve chamber to the outflow path, wherein the pilot valve chamber side end of the pilot passage becomes the pilot valve port; A pressure equalization circuit, which connects the main valve chamber to the pilot valve chamber; and A pilot valve core, which is fixed to the main valve core side of the plunger, and is an elastic body that opens and closes the pilot valve port according to the movement of the plunger. The pilot valve core is positioned radially inside the electromagnetic coil within the range of motion of the plunger. The main valve core has a shaft that extends toward the plunger along the direction of movement of the plunger, and the pilot passage is formed inside the shaft.

2. The solenoid valve according to claim 1, characterized in that, The shaft portion has an abutting portion. When the end of the shaft portion on the pilot valve core side abuts against the pilot valve core, the abutting portion prevents the main valve core from moving further toward the pilot valve core side by abutting against the plunger.

3. The solenoid valve according to claim 1, characterized in that, have: A first spring, relative to the suction member, applies force to the plunger toward the side away from the suction member; as well as The second spring, relative to the suction element, applies force to the main valve core toward the plunger side.

4. The solenoid valve according to claim 3, characterized in that, The outer peripheral surface of the shaft portion has a protrusion. The second spring applies force to the protrusion toward the plunger side.

5. The solenoid valve according to claim 4, characterized in that, The shaft portion is configured to have multiple valve shafts fixed in place. One of the plurality of valve shafts has the protrusion.

6. The solenoid valve according to claim 4, characterized in that, A protrusion forming component is fixed to the shaft portion, and this protrusion forming component is a component different from the shaft portion. The protrusion forming component forms the protrusion.

7. The solenoid valve according to claim 1, characterized in that, The plunger is hollow, and a recess for holding the pilot valve core is formed on the suction side of the plunger. The interior of the recess is connected to the interior of the plunger via a connecting passage.

8. The solenoid valve according to any one of claims 1 to 7, characterized in that, The solenoid valve is fixed to the structure in a detachable manner. The construct has: A mounting hole is provided for the valve body to be inserted in a removable manner; A high-pressure flow path, which is provided at the opening of the mounting hole; as well as The low-pressure flow path is located at the opening of the mounting hole. With the valve body positioned in the mounting hole, The inflow path is connected to the high-pressure flow path. The outflow path is connected to the low-pressure flow path.

9. A solenoid valve device, characterized in that, have: The solenoid valve according to any one of claims 1 to 7; and Construct, The construct has: A mounting hole is provided for the valve body to be inserted in a removable manner; A high-pressure flow path, which is provided at the opening of the mounting hole; as well as The low-pressure flow path is located at the opening of the mounting hole. With the valve body positioned in the mounting hole, The inflow path is connected to the high-pressure flow path. The outflow path is connected to the low-pressure flow path.

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