Solenoid valve

Abstract

We provide low-cost yet highly reliable solenoid valves. [Solution] The solenoid valve includes a pilot valve body which is an elastic body fixed to the main valve body side of the plunger and opens and closes a pilot valve port in accordance with the movement of the plunger, the pilot valve body is positioned radially inward of the electromagnetic coil within the range of movement of the plunger, and the main valve body has a shaft portion which extends toward the plunger side along the direction of movement of the plunger and has the pilot passage formed inside, and the shaft portion is capable of contacting the pilot valve body.

Description

Technical Field

[0001] The present invention relates to a solenoid valve.

Background Art

[0002] A solenoid valve provided with a pilot valve body that opens and closes the valve by using the differential pressure on both sides in the flow direction sandwiching the valve body is disclosed in, for example, Patent Document 1. According to this conventional solenoid valve, when the plunger moves in one direction by energizing the electromagnetic coil, the pilot valve hole of the valve body is closed, so the internal pressure of the pilot chamber rises, and the valve body seats on the valve seat to block the fluid flow from the high-pressure side flow path to the low-pressure side flow path. Also, when the energization of the electromagnetic coil is stopped and the plunger moves in the other direction by the biasing force of the spring, the pilot valve hole opens, and the fluid in the pilot chamber flows downstream through the pilot valve hole, reducing the internal pressure of the pilot chamber. Therefore, the valve body separates from the valve seat and the fluid flow from the high-pressure side flow path to the low-pressure side flow path resumes.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, according to the solenoid valve of Patent Document 1, a pilot valve body that is movable integrally with the plunger is arranged so as to extend inside the shaft portion of the armature, and the pilot valve hole of the valve body is closed according to the operation of the plunger. However, according to such a solenoid valve, it is necessary to process the shaft portion of the armature into an elongated shape. Generally, since the armature is made of an expensive magnetic material by cutting, there is a problem that the cutting amount increases and the processing cost becomes high.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a solenoid valve that is low-cost and highly reliable. [Means for solving the problem]

[0006] The solenoid valve of the present invention is A valve body having a main valve chamber inside, an inlet passage for introducing fluid into the main valve chamber, and an outlet passage for introducing the fluid out of the main valve chamber, and having a main valve port formed at the end of the outlet passage on the main valve chamber side, A main valve body that moves back and forth relative to the main valve opening to open and close the main valve opening, Plunger and, An electromagnetic drive device for driving the plunger includes a suction element fixed to the valve body for attracting the plunger, a sleeve fixed to the suction element for movably housing the plunger, and an electromagnetic coil arranged around the sleeve. Within the sleeve, a pilot valve chamber is formed between the plunger and the suction element, A pilot passage that penetrates the main valve body, selectively connecting the pilot valve chamber and the outflow passage, with the pilot valve chamber side end of the pilot passage being a pilot valve opening, A pressure equalization passage connecting the main valve chamber and the pilot valve chamber, A solenoid valve equipped with, The plunger is fixed to the main valve body side and comprises a pilot valve body which is an elastic body that opens and closes the pilot valve port in accordance with the movement of the plunger, The pilot valve body is positioned radially inward of the electromagnetic coil within the range of movement of the plunger. The main valve body is characterized in that it has a shaft portion that extends toward the plunger along the direction of movement of the plunger and in which the pilot passage is formed. [Effects of the Invention]

[0007] This invention provides a solenoid valve that is low-cost yet highly reliable. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a longitudinal sectional view of a solenoid valve (excluding the valve body) according to the first embodiment. [Figure 2] Figure 2 is a sectional view showing an enlarged view of the vicinity of the lower end of the plunger of the solenoid valve. [Figure 3] Figure 3 is a sectional view showing an enlarged view of the vicinity of the lower end of the plunger of the solenoid valve. [Figure 4] Figure 4 is a sectional view showing the vicinity of the lower end of the plunger according to Modification 1 of the first embodiment. [Figure 5] Figure 5 is a sectional view showing the vicinity of the lower end of the plunger according to Modification 2 of the first embodiment. [Figure 6] Figure 6 is a sectional view showing the vicinity of the lower end of the plunger according to Modification 3 of the first embodiment. [Figure 7] Figure 7 is a sectional view showing the vicinity of the lower end of the plunger according to Modification 4 of the first embodiment. [Figure 8] Figure 8 is a sectional view showing the vicinity of the lower end of the main valve body according to Modification 5 of the first embodiment. [Figure 9] Figure 9 is a sectional view showing the vicinity of the lower end of the main valve body according to Modification 6 of the first embodiment. [Figure 10] Figure 10 is a longitudinal sectional view of a solenoid valve according to the second embodiment. [Figure 11] Figure 11 is a longitudinal sectional view of a solenoid valve according to the third embodiment. [Figure 12] Figure 12 is a longitudinal sectional view of a solenoid valve according to a modification of the third embodiment. [Figure 13] Figure 13 is a longitudinal sectional view of a solenoid valve according to the fourth embodiment. [Figure 14] Figure 14 is a longitudinal sectional view of the main valve body. [Figure 15] Figure 15 is a view showing an enlarged view of part C of the solenoid valve in Figure 13. [Figure 16] Figure 16 is a view showing an enlarged view of part C of the solenoid valve in Figure 13.

Modes for Carrying Out the Invention

[0009] Hereinafter, an embodiment of a solenoid valve and a solenoid valve device, which are one type of the solenoid valve of the present invention, will be described with reference to the drawings. In this specification, the upper side refers to the side of the plunger (or coil) with respect to the armature, and the lower side refers to the side of the armature with respect to the plunger.

[0010] (First Embodiment) FIG. 1 is a longitudinal sectional view of a solenoid valve 1 according to the first embodiment. FIG. 2 is a sectional view showing an enlarged view near the lower end of the plunger of the solenoid valve 1, showing the closed state of the pilot valve port, and FIG. 3 is a sectional view showing an enlarged view near the lower end of the plunger of the solenoid valve 1, showing the open state of the pilot valve port. The axis of the solenoid valve 1 is designated as L.

[0011] As shown in FIG. 1, the solenoid valve 1 has a valve body 10, an armature 40, a plunger 50, a main valve body 70, and a coil unit 80. Note that the armature 40, the plunger 50 to which the pilot valve body 51 is attached, the coil unit 80, and a sleeve member 44 described later constitute an electromagnetic drive device.

[0012] The valve body 10 has a block-shaped main body portion 11. Inside the main body portion 11, a high-pressure flow path (inflow path) 12 and a low-pressure flow path (outflow path) 13 that are arranged opposite to each other, and a circular opening 14 are formed so as to intersect the axis. The inner end of the high-pressure flow path 12 to which a high-pressure pipe (not shown) is connected communicates with the inner end of the circular opening 14. Further, the inner side of the low-pressure flow path 13 to which a low-pressure pipe (not shown) is connected bends in an L shape, and its cylindrical end portion 13a protrudes coaxially with the circular opening 14 into the circular opening 14. The upper end of the cylindrical end portion 13a serves as a main valve seat 13b that constitutes the main valve port, and the periphery of the cylindrical end portion 13a serves as the main valve chamber VC.

[0013] The mounting surface 11a that is the upper surface of the main body portion 11 is a plane orthogonal to the axis L, and the coil unit 80 is mounted thereon. A circular opening 14 opens coaxially with the axis L on the mounting surface 11a.

[0014] A suction element 40 is installed inside the circular opening 14. The suction element 40 consists of a disc-shaped base 41 and a cylindrical portion 42 having a smaller diameter than the base 41, connected coaxially. The base 41 has a circular opening 41a formed in the center of its lower end. A through hole 41b is formed spanning the base 41 and the cylindrical portion 42, communicating with the center of the opening 41a and opening towards the upper end. The through hole 41b consists of an upper hole 41c, a middle hole 41d having a smaller diameter than the upper hole 41c and connected to the lower end of the upper hole 41c, and a lower hole 41e having a larger diameter than the middle hole 41d and connected to the lower end of the middle hole 41d.

[0015] The suction element 40 is fixed to the main body 11 of the valve body 10 by screwing the male thread formed on the outer circumference of the base 41 into the female thread formed on the inner circumference of the circular opening 14, while the lower outer circumference of the base 41 abuts against the inner stepped portion of the circular opening 14. At this time, an O-ring OR is placed between the base 41 and the circular opening 14 to prevent fluid leakage through the gap between them.

[0016] With the base portion 41 attached to the circular opening 14, the cylindrical portion 42 protrudes upward from the mounting surface 11a. The lower end of a thin-walled, top-cylindrical sleeve member (sleeve) 44 is joined coaxially to the upper end of the cylindrical portion 42 by welding or brazing. A hollow plunger 50 is positioned inside the sleeve member 44.

[0017] The plunger 50, which has a bottomed cylindrical shape, has a first communication hole 50a formed in the center of the bottom wall, a cylindrical recess 50b communicating with the lower end of the first communication hole 50a, an annular retaining portion 50c protruding radially inward from the lower end of the cylindrical recess 50b, and a second communication hole 50d formed near the upper end of the side wall of the plunger 50. A disc-shaped pilot valve body 51, made of rubber such as EPDM or HNBR as an elastic body, is arranged in the cylindrical recess 50b so that its upper end and outer circumference are in close contact with the inner surface of the cylindrical recess 50b. The pilot valve body 51, which is arranged radially inside the electromagnetic coil 81 of the coil unit 80, is preferably located near the axial center of the electromagnetic coil 81 when the plunger 50 is at the upper end of its stroke (Figure 1).

[0018] If a plunger without a first communication hole (communication passage) 50a is installed, when the pilot valve body 51 is attached to the cylindrical recess 50b, refrigerant (fluid) interposed between the two may accumulate. As the temperature of the solenoid valve 1 rises, the refrigerant may expand due to heat, potentially pushing the pilot valve body 51 out of the cylindrical recess 50b. In contrast, by connecting the inside of the plunger 50 and the cylindrical recess 50b via the first communication hole 50a, the refrigerant that has expanded due to heat in the cylindrical recess 50b can be released into the inside of the plunger 50, thus resolving the above problem. The second communication hole 50d functions to ensure smooth movement of the plunger 50 by equalizing the pressure applied to both sides in the direction of movement of the plunger 50 through it.

[0019] When assembling the pilot valve body 51 to the plunger 50, it is elastically deformed to pass inside the annular retaining portion 50c, and after passing through, it is returned to its original shape from elastic deformation to be tightly positioned within the cylindrical recess 50b. After assembly, the pilot valve body 51 is held in place by the annular retaining portion 50c to prevent it from falling out, and the plunger 50 and the pilot valve body 51 are integrated.

[0020] The main valve body 70 has a valve stem 71 and an outer cylindrical portion 73 and an inner cylindrical portion 74 attached to the lower end of the valve stem 71.

[0021] The valve stem 71, which is the shaft portion, is made of metal and consists of, in order from the upper end, a first cylindrical portion 71a, a second cylindrical portion 71b which is larger in diameter than the first cylindrical portion 71a, a flange portion 71c which is larger in diameter than the second cylindrical portion 71b, and a third cylindrical portion 71d which is approximately the same diameter as the second cylindrical portion 71b. The outer diameter of the third cylindrical portion 71d is smaller than the inner diameter of the main valve seat 13b. A male screw 71e is formed on the outer circumference of the third cylindrical portion 71d. The valve stem 71 also has a pilot passage 71f that penetrates in the vertical direction. The upper end of the first cylindrical portion 71a through which the pilot passage 71f passes constitutes the pilot valve port.

[0022] As shown in Figure 3, the outer diameter of the first cylindrical portion 71a is smaller than the inner diameter of the annular holding portion 50c, and the length A of the first cylindrical portion 71a is larger by a predetermined amount than the thickness B (length in the direction of the axis L) of the annular holding portion 50c.

[0023] In Figure 1, the inner cylindrical portion 74 is a rubber annular member with a downward-facing outer circumferential step formed on its outer circumference. On the other hand, the outer cylindrical portion 73 is a metal annular member that is longer axially than the inner cylindrical portion 74, with an upward-facing inner circumferential step formed on its inner circumference. The outer cylindrical portion 73 also has a pressure equalization passage 73a that penetrates in the vertical direction and a crimped portion 73b that protrudes from the inner circumferential edge of the upper end. The main valve chamber VC and the upper space UC above the outer cylindrical portion 73 and the inner cylindrical portion 74 are in communication via the pressure equalization passage 73a.

[0024] When assembling the main valve body 70, first the male thread 71e on the lower end of the valve stem 71 is screwed into the inner cylindrical portion 74. This creates a female thread on the inner circumference of the inner cylindrical portion 74 corresponding to the male thread 71e, and the valve stem 71 and the inner cylindrical portion 74 are integrated by the screw-to-screw action. However, the female thread may be formed on the inner circumference of the inner cylindrical portion 74 in advance.

[0025] Subsequently, the valve stem 71 and the inner cylindrical portion 74 are fitted into the outer cylindrical portion 73, and the crimped portion 73b, which was a thin-walled cylindrical shape before assembly, is bent radially inward and plastically deformed to hold the upper surface of the flange portion 71c of the valve stem 71. This integrally forms the main valve body 70.

[0026] The pressure equalization passage 73a penetrates the upper and lower end faces of the outer cylindrical portion 73 and also opens on the inner circumference side of the outer cylindrical portion 73. This is to discharge the refrigerant that accumulates between the inner cylindrical portion 74 and the outer cylindrical portion 73 through the pressure equalization passage 73a. If refrigerant accumulates between the inner cylindrical portion 74 and the outer cylindrical portion 73, when the temperature of the solenoid valve 1 rises, the refrigerant may expand due to heat, potentially causing problems such as the inner cylindrical portion 74 being pushed out from the outer cylindrical portion 73. However, by connecting the pressure equalization passage 73a to the inner circumference side of the outer cylindrical portion 73, such problems can be suppressed.

[0027] The main valve body 70 is biased toward the plunger 50 side relative to the base 41 of the suction element 40 by the lower spring 75.

[0028] A coil spring 60 is positioned between the stepped portion between the upper hole 41c and the middle hole 41d of the suction element 40 and the lower surface of the bottom wall of the plunger 50, biasing the plunger 50 upward relative to the suction element 40. The lower end of the plunger 50 has a tapered shape that decreases in diameter as it goes downward, and the upper end of the cylindrical portion 42 of the suction element 40 has a tapered shape that is complementary to it. Inside the sleeve member 44, the space between the plunger 50 and the suction element 40 is called 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 stem 71 and the through hole 41b (called the pressure equalization passage CP).

[0029] The coil unit 80 comprises a hollow cylindrical electromagnetic coil (coil) 81, a bobbin 82 around which the electromagnetic coil 81 is wound, and a case 83 for holding the bobbin 82, and is molded in resin.

[0030] (Solenoid valve operation) When the electromagnetic coil 81 is powered from a power source (not shown), the magnetic field generated by the electromagnetic coil 81 creates a magnetic path through the plunger 50, the attractor 40, and the case 83, generating a magnetic force that pushes down the plunger 50 against the biasing force of the coil spring 60. When the plunger 50 is pushed down, the pilot valve body 51 also descends, and as shown in Figure 2, its lower surface comes into contact with the upper end of the first cylindrical portion 71a of the valve stem 71. With the pilot passage 71f blocked, the main valve body 70 is pushed down and the inner cylindrical portion 74 shields the main valve seat 13b.

[0031] At this time, as shown in Figure 2, the stepped portion (contact portion AP) of the first cylindrical portion 71a and the second cylindrical portion 71b of the valve stem 71 contacts the lower surface of the plunger 50, thereby suppressing an excessive increase in surface pressure between the first cylindrical portion 71a and the lower surface of the pilot valve body 51, and thus suppressing wear of the pilot valve body 51. In other words, the 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 prevents fluid leakage from the pilot valve body 51 and suppresses wear during long-term use. The predetermined amount varies depending on the material of the pilot valve body 51, for example.

[0032] When the pilot passage 71f is blocked, the pressure in the upper space UC above the outer cylindrical portion 73, which communicates with the high-pressure passage 12 via the equalizing passage 73a, becomes greater than the internal pressure of the cylindrical end portion 13a (pressure in the lower space LC) which communicates with the low-pressure passage 13. As a result, the main valve body 70 remains seated on the main valve seat 13b against the biasing force of the lower spring 75, and the fluid flow from the high-pressure passage 12 to the low-pressure passage 13 is blocked.

[0033] In contrast, if the power supply from the power source (not shown) to the electromagnetic coil 81 is interrupted, the magnetic force pushing down the plunger 50 disappears, and the biasing force of the coil spring 60 pushes the plunger 50 upward, causing the pilot valve body 51 to rise and move away from the first cylindrical portion 71a of the valve stem 71, as shown in Figure 3, opening the pilot passage 71f. As a result, fluid flows from the pilot valve chamber PC to the low-pressure flow path 13 through the pilot passage 71f, and the differential pressure between the upper space UC (equal to the pilot valve chamber PC) and the lower space LC (more precisely, the differential pressure between the outer peripheral space of the cylindrical end 13a and the portion projected onto the upper space UC) approaches zero. More specifically, the pressure in the upper space UC becomes approximately the same as the pressure in the lower space LC, and furthermore, the pressure in the upper space UC becomes smaller than the pressure in the main valve chamber VC, causing the main valve body 70 to rise. As a result, a gap is created 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 and then through the cylindrical end portion 13a to the low-pressure flow path 13. The outer circumferential space of the cylindrical end portion 13a has a pressure closer to that of the high-pressure flow path 12 than to that of the low-pressure flow path 13, while the inner circumferential space of the cylindrical end portion 13a and the pilot valve chamber PC have a pressure closer to that of the low-pressure flow path 13 than to that of the high-pressure flow path 12.

[0034] In one conventional type of solenoid valve, a pilot valve body is provided extending from the lower end of the plunger through an attractive element, and the pilot valve opening of the annular main valve body is closed according to the movement of the plunger. However, with such a solenoid valve, it is necessary to ensure a long cylindrical portion of the attractive element, but there is a problem in that the processing cost is high when forming the attractive element, which is generally made of a magnetic material, by machining.

[0035] In contrast, according to this embodiment, the valve stem 71 of the main valve body 70 is extended toward the plunger 50, and the outer side of the cylindrical portion 42 of the suction element 40 can come into close contact with the pilot valve body 51, thereby blocking the pilot passage 71f. This allows the axial length of the cylindrical portion 42 to be kept short, thereby reducing processing costs.

[0036] Furthermore, by making the pilot valve body 51 attached to the plunger 50 out of rubber with a low Young's modulus, fluid leakage can be effectively suppressed even when the differential pressure on both sides in the direction of movement of the main valve body 70 is small and the pressing force of the main valve body 70 against the pilot valve body 51 is relatively low. In addition, since the pilot valve body 51 is located radially inside the electromagnetic coil 81, the pilot valve body 51 is heated by heat transfer from the electromagnetic coil 81 when power is supplied, and even if a low-temperature refrigerant is supplied to the pilot valve chamber PC as a result, the pilot valve body 51 can be given sufficient flexibility to prevent fluid leakage when the valve is closed.

[0037] (Modification 1 of the first embodiment) Figure 4 is a cross-sectional view showing the vicinity of the lower end of the plunger 50A according to Modification 1 of the First Embodiment. In this modification, only the shape of the lower end of the plunger 50A differs from that of the First Embodiment; the other configurations are the same as those of the First Embodiment, so redundant explanations are omitted.

[0038] In this modified example, the plunger 50A does not have an annular retaining portion, and the cylindrical recess 50b opens to the lower end of the plunger 50A. The pilot valve body 51 is attached to the cylindrical recess 50b by vulcanization bonding. If the pilot valve body 51 is completely sealed to the cylindrical recess 50b by vulcanization bonding, the entry of refrigerant between the pilot valve body 51 and the cylindrical recess 50b can be suppressed, so the first communication hole 50a may be omitted. In addition, although the coil spring 60 is in contact with the lower surface of the pilot valve body 51, it may be made to be in contact with the lower surface of the plunger 50A.

[0039] (Modification 2 of the first embodiment) Figure 5 is a cross-sectional view showing the vicinity of the lower end of the plunger 50B according to Modification 2 of the First Embodiment. In this modification as well, only the shape of the lower end of the plunger 50B differs from that of the First Embodiment, and the other configurations are the same as those of the First Embodiment, so a redundant explanation will be omitted.

[0040] In this modified example, the plunger 50B does not have an annular retaining portion. Instead, a ring member 52 is provided that fits onto the inner circumference of the cylindrical recess 50b. The pilot valve body 51 is installed in the cylindrical recess 50b, and the ring member 52 is attached to the cylindrical recess 50b by press-fitting so that it is positioned below the pilot valve body 51. Since the inner diameter of the ring member 52 is larger than the outer diameter of the first cylindrical portion 71a, the ring member 52 does not prevent the valve stem 71 from contacting the pilot valve body 51. The length of the first cylindrical portion 71a is greater by a predetermined amount than the thickness of the ring member 52.

[0041] (Modification 3 of the first embodiment) Figure 6 is a cross-sectional view showing the vicinity of the lower end of the plunger 50C according to Modification 3 of the First Embodiment. In this modification as well, only the shape of the lower end of the plunger 50C differs from that of the First Embodiment, and the other configurations are the same as those of the First Embodiment, so redundant explanations are omitted.

[0042] In this modified example, the plunger 50C does not have an annular retaining portion, but instead has a crimped retaining portion 50Cc that protrudes from the lower end of the plunger 50C. After assembling the pilot valve body 51 into the cylindrical recess 50b, the crimped retaining portion 50Cc, which was a thin-walled cylindrical shape before assembly, is bent radially inward to undergo plastic deformation, thereby holding the lower surface of the pilot valve body 51 and preventing it from falling out.

[0043] (Modification 4 of the first embodiment) Figure 7 is a cross-sectional view showing the vicinity of the lower end of the plunger 50D according to Modification 4 of the first embodiment. In this modification as well, only the shape of the lower end of the plunger 50D differs from that of the first embodiment; the other configurations are the same as those of the first embodiment, so a redundant explanation is omitted.

[0044] In this modified example, the plunger 50D does not have an annular retaining portion, but instead has crimping claw portions 50Dc protruding from the lower end of the plunger 50C. Multiple crimping claw portions 50Dc are spaced equally in the circumferential direction and extend downward from the lower end of the plunger 50D. After assembling the pilot valve body 51 into the cylindrical recess 50b, each crimping claw portion 50Dc is bent radially inward to plastically deform it, thereby holding the lower surface of the pilot valve body 51 and preventing it from falling out.

[0045] (Modification 5 of the first embodiment) Figure 8 is a cross-sectional view showing the vicinity of the lower end of the main valve body 70E according to Modification 5 of the first embodiment. In this modification as well, only the configuration of the valve stem 71E differs from that of the first embodiment; the other configurations are the same as in the first embodiment, so a redundant explanation is omitted.

[0046] In this modified example, the valve stem 71E does not have a male thread formed on the third cylindrical portion 71Ed and has a cylindrical outer circumference. The other configurations are the same as in the first embodiment. The inner cylindrical portion 74 is attached to the third cylindrical portion 71Ed by vulcanization bonding.

[0047] (Modification 6 of the first embodiment) Figure 9 is a cross-sectional view showing the vicinity of the lower end of the main valve body 70F according to Modification 6 of the first embodiment. In this modification as well, only the configuration of the valve stem 71F differs from that of the first embodiment; the other configurations are the same as in the first embodiment, so a redundant explanation is omitted.

[0048] In this modified example, the valve stem 71F has a tapered crimped lower end 71Fd that expands in diameter as it goes downwards, instead of a third cylindrical portion. The crimped lower end 71Fd does not have a male thread. The rest of the configuration is the same as in the first embodiment. After fitting the inner cylindrical portion 74 around the crimped lower end 71Fd, which is cylindrical before assembly, the crimped lower end 71Fd is plastically deformed to expand in diameter in a tapered shape, thereby preventing the inner cylindrical portion 74 from falling out. At this time, the inner cylindrical portion 74 elastically deforms in accordance with the deformation of the crimped lower end 71Fd. Since the outer diameter of the crimped lower end 71Fd after deformation is smaller than the inner diameter of the main valve seat 13b, the inner cylindrical portion 74 can come into contact with the main valve seat 13b.

[0049] (Second embodiment) Figure 10 is a longitudinal cross-sectional view of the solenoid valve 1G according to the second embodiment. In this embodiment, only the configuration of the main body portion 11G of the valve body 10G differs from that of the first embodiment; all other configurations are the same as in the first embodiment, so the same reference numerals are used and redundant explanations are omitted.

[0050] The solenoid valve 1G in this embodiment is a so-called cartridge type, and the valve body 10G, the suction element 40, the plunger 50, the main valve body 70, and the coil unit 80 are integrated and can be attached to the mating structure ST. The solenoid valve 1G and the mating structure ST constitute a solenoid valve device.

[0051] The cylindrical main body 11G has a large cylindrical portion 11Ga, a small cylindrical portion 11Gb which has a smaller diameter than the large cylindrical portion 11Ga, an intermediate wall portion 11Gc which coaxially connects 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 which extends from the intermediate wall portion 11Gc toward the main valve body 70. The upper end of the cylindrical end portion 13Ga constitutes the valve seat 13Gb, and the inside of the cylindrical end portion 13Ga constitutes the lower space LC.

[0052] The suction element 40 is attached to the main body 11G by screwing the male thread formed on the base 41 of the suction element 40 into the female thread formed on the inner circumference near the upper end of the large cylindrical portion 11Ga. At this time, the space between the inner circumference of the large cylindrical portion 11Ga and the outer circumference of the base 41 is sealed by an O-ring OR.

[0053] An upper circumferential groove 11Gd and a male thread 11Ge are formed on the outer circumference of the large cylindrical portion 11Ga. A first O-ring OR1 is positioned in the upper circumferential groove 11Gd. A lower circumferential groove 11Gf is formed on the outer circumference of the small cylindrical portion 11Gb. A second O-ring OR2 is positioned in the lower circumferential groove 11Gf.

[0054] The mounting hole of the mating structure ST has a high-pressure passage and a low-pressure passage formed therein. The main body 11G of the solenoid valve 1G can be installed in the mounting hole by engaging the main body 11G of the solenoid valve 1G with the male thread 11Ge with the female thread formed on the inner circumference of the mounting hole. At this time, the first O-ring OR1 and the second O-ring OR2 come into contact with the inner circumference of the mounting hole, separating the high-pressure passage and the low-pressure passage so that fluid cannot pass through them, and preventing refrigerant from leaking through the gap between the mounting hole and the main body 11G.

[0055] The high-pressure flow path STa of the opposing structure ST communicates with the internal space (main valve chamber VC) of the large cylindrical portion 11Ga through a plurality (e.g., 6) of lateral holes 11Gg formed in the large cylindrical portion 11Ga (which constitute part of the high-pressure flow path). The internal space of the large cylindrical portion 11Ga also communicates with the low-pressure flow path STb of the opposing structure ST through a discharge passage 13Gc formed inside the small cylindrical portion 11Gb and the cylindrical end portion 13Ga (which constitute part of the low-pressure flow path).

[0056] In this embodiment as well, when the main valve body 70 descends in response to power being supplied to the electromagnetic coil 81, the valve seat 13Gb is blocked, thereby interrupting the flow of fluid from the high-pressure channel to the low-pressure channel.

[0057] In contrast, when the power supply to the electromagnetic coil 81 is stopped, the main valve body 70 rises and the valve seat 13Gb opens, allowing fluid to flow from the high-pressure passage through the lateral hole 11Gg, the main valve chamber VC, and the discharge passage 13Gc to the low-pressure passage.

[0058] (Third embodiment) Figure 11 is a longitudinal cross-sectional view of the solenoid valve 1H according to the third embodiment. This embodiment differs from the first embodiment mainly in the configuration of the suction element 40H, plunger 50H, and main valve body 70H. Since the other configurations are the same as in the first embodiment, the same reference numerals are used and redundant explanations are omitted.

[0059] The through-hole 41Hb of the suction element 40H consists 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 small 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 small hole 41Hg. The other configurations are the same as in the first embodiment.

[0060] The plunger 50H differs from the first embodiment only in that it has a cylindrical tube portion 50He formed at its lower end. The pilot valve body 51, which is located in the cylindrical recess 50b, is held by a ring member 52, but the configuration is not limited to the first embodiment or its modifications 1, 3, 4, etc., can also be applied.

[0061] The valve stem of the main valve body 70H has an upper valve stem (first valve stem) 76H and a lower valve stem (second valve stem) 77H as its shaft portion. The upper valve stem 76H is made up of a tapered cylindrical portion 76Ha, a middle cylindrical portion 76Hb, and a lower cylindrical portion (protruding portion) 76Hc with a larger diameter than the middle cylindrical portion 76Hb, arranged in order from the upper end, and further has an upper through hole 76Hd that penetrates the upper valve stem 76H in the vertical direction. An internal thread 76He is formed on the inner circumference of the lower cylindrical portion 76Hc.

[0062] The lower valve stem 77H is formed by connecting, in order from the upper end, a first cylindrical portion 77Ha having a smaller diameter than the inner diameter of the lower cylindrical portion 76Hc, a second cylindrical portion 77Hb having a larger diameter than the first cylindrical portion 77Ha and also larger than the inner diameter of the lower cylindrical portion 76Hc, a flange portion 77Hc having a larger diameter than the second cylindrical portion 77Hb, and a third cylindrical portion 77Hd. A male thread 77He is formed on the outer circumference of the first cylindrical portion 77Ha. The lower valve stem 77H has a lower through-hole 77Hf that penetrates in the vertical direction. The upper through-hole 76Hd and the lower through-hole 77Hf constitute a pilot passage.

[0063] The upper valve stem 76H is coaxially attached to the upper end of the lower valve stem 77H by screwing the male thread 77He of the first cylindrical portion 77Ha into the female thread 76He of the lower cylindrical portion 76Hc. A coil spring (first spring) 60 is positioned between the stepped portion between the upper hole 41Hc and the middle hole 41Hd of the suction element 40H and the plunger 50H, biasing the plunger 50H upward relative to the suction element 40H. Furthermore, a coil spring (second spring) 61 is positioned between the stepped portion between the middle hole 41Hd and the narrow hole 41Hg of the suction element 40H and the lower end of the upper valve stem 76H, biasing the upper valve stem 76H (i.e., the main valve body 70H) upward relative to the suction element 40H. The outer diameters of the coil springs 60 and 61 are equal from the upper end to the lower end. By providing the coil spring 61, the conical lower spring 75 and its retaining structure used in the first embodiment can be omitted, contributing to cost reduction.

[0064] The elastic force of the coil spring 60 is set to a value that allows the plunger 50H to return to the upper stroke end when the electromagnetic coil 81 is not powered. Furthermore, the elastic force of the coil spring 61 is set to exceed the downward force applied to the main valve body 70H due to the vertical differential pressure it experiences. According to this embodiment, since the coil springs 60 and 61 are arranged independently, there is the advantage that the design of the coil springs is simplified.

[0065] (Modified version of the third embodiment) Figure 12 is a longitudinal cross-sectional view of a modified solenoid valve 1I according to the third embodiment. This embodiment differs from the third embodiment mainly in the configuration of the main valve body 70I, and the other components are the same as in the third embodiment, so the same reference numerals are used and redundant explanations are omitted.

[0066] The main valve body 70I differs from the third embodiment only in the valve stem 71I; otherwise, its configuration is the same as that of the third embodiment. The valve stem 71I, which is the shaft portion, consists of a tapered cylindrical portion 71Ia, a second cylindrical portion 71Ib, a flange portion 71Ic with a larger diameter than the second cylindrical portion 71Ib, and a third cylindrical portion 71Id with approximately the same diameter as the second cylindrical portion 71Ib, arranged in that order from the upper end. The valve stem 71 also has a pilot passage 71If that penetrates in the vertical direction.

[0067] Furthermore, a circumferential groove 71Ig is formed in the second cylindrical portion 71Ib, and a C-shaped clip (projection forming member) 78 is attached to the circumferential groove 71Ig.

[0068] A coil spring 60 is positioned between the stepped portion between the upper hole 41Hc and the middle hole 41Hd of the suction element 40H and the plunger 50H, biasing the plunger 50H upward relative to the suction element 40H. Furthermore, a coil spring 61 is positioned between the stepped portion between the middle hole 41Hd and the narrow hole 41Hg of the suction element 40H and the lower surface of the clip 78, biasing the valve stem 71I (main valve body 70I) upward relative to the suction element 40H.

[0069] Similar to the third embodiment, the coil springs 60 and 61 are arranged independently, which simplifies the design of the coil springs.

[0070] The third embodiment shows an example with two valve stems. In other examples, there may be three or more valve stems, and one of these three or more may have a protrusion.

[0071] Furthermore, the clip 78 is an example of a protruding part forming member. The configuration of forming a groove on the shaft and fixing the clip in the groove is just one example; it may also be fixed by fitting, for example, without using a groove. Moreover, the groove is not limited to being long in the circumferential direction (the circumference is longer than the axial length). Other examples include a groove or recess that is long in the axial direction of the shaft.

[0072] The third embodiment and its modifications described above are examples of the invention of claim 4. In other examples, the shaft portion may be one and the projection portion may be integrated (meaning not a separate component). The projection portion may have any shape that can receive the second spring, such as a continuous annular shape in the circumferential direction or a discontinuous shape in the circumferential direction, such as a C-shape.

[0073] (Fourth embodiment) Figure 13 is a longitudinal cross-sectional view of the solenoid valve 1J according to the fourth embodiment. Figure 14 is a longitudinal cross-sectional view of the main valve body 70J. Figure 15 is an enlarged view of section C of the solenoid valve 1J in Figure 13, showing the closed state of the pilot valve port, and Figure 16 is an enlarged view of section C of the solenoid valve 1J in Figure 13, showing the open state of the pilot valve port. This embodiment differs from the first embodiment mainly in the configuration of the main valve body 70J. The valve body 10, plunger 50, suction element 40, coil unit 80, etc., have slightly different shapes from the first embodiment, but their functions are the same, so they are given the same reference numerals and redundant explanations are omitted. Similarly, the other components are the same as in the first embodiment, so they are given the same reference numerals and redundant explanations are omitted.

[0074] The pilot valve body 51, positioned in the cylindrical recess 50b of the plunger 50, is held by a ring member 52 that is press-fitted into the plunger 50 by a crimped portion 54 or fixed by crimping. However, the configuration is not limited to this, and the configurations of the first embodiment or its modifications 1, 3, 4, etc., can also be applied. The case 83 of the coil unit 80 is fastened to the main body 11 of the valve body 10 by a screw SC.

[0075] The main valve body 70J has a valve body base 71J and a cylindrical portion 74J attached to the lower end of the valve body base 71J.

[0076] In Figure 14, the valve body base 71J is made of metal and consists of, in order from the upper end, a first cylindrical portion 71Ja, a second cylindrical portion 71Jb which is larger in diameter than the first cylindrical portion 71Ja, a central cylindrical portion 71Jc which is larger in diameter than the second cylindrical portion 71Jb, a third cylindrical portion 71Jd which is smaller in diameter than the central cylindrical portion 71Jc, and a lower cylindrical portion 71Je which is larger in diameter than the third cylindrical portion 71Jd. The valve body base 71J has a pilot passage 71Jf that penetrates in the vertical direction, and a pressure equalization passage 71Jg that penetrates in the vertical direction parallel to the pilot passage 71Jf in the central cylindrical portion 71Jc.

[0077] The center of the upper surface of the central cylindrical portion 71Jc is recessed, and the space between the central cylindrical portion 71Jc and the bottom plane of the opening 41a of the suction element 40 forms the upper space UC (Figure 13). The upper space UC communicates with 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 portion 13a) via the pressure equalization passage 71Jg. In addition, the pilot valve chamber PC between the plunger 50 and the main valve body 70J communicates with the upper space UC via the gap between the second cylindrical portion 71Jb and the cylindrical portion 42.

[0078] A circumferential groove 71Jh is formed on the outer circumference of the central cylindrical portion 71Jc, and a sealing member SL is placed in the circumferential groove 71Jh to seal the space between the outer circumference of the central cylindrical portion 71Jc and the inner circumference of the opening 41a. A lower spring 75 is placed between the stepped portion on the outer circumference of the lower end of the central cylindrical portion 71Jc and the valve body 10, biasing the main valve body 70J toward the plunger 50.

[0079] A cylindrical recess 71Jk is formed on the lower surface of the lower cylindrical portion 71Je, a circular pipe portion 71Ji is formed in the center of the recess 71Jk, and a pilot passage 71Jf passes through the center of the recess 71Jk.

[0080] A rubber cylindrical portion 74J is fitted into the annular space between the inner circumference of the recess 71Jk and the outer circumference of the circular pipe portion 71Ji.

[0081] After assembling the cylindrical portion 74J into the recess 71Jk, the washer 79 is engaged with the circular pipe portion 71Ji, for example by crimping, thereby preventing the cylindrical portion 74J from falling out. Furthermore, by plastically deforming the lower outer circumference of the recess 71Jk radially inward, the inner edge of the deformed portion is hooked onto the outer stepped portion of the cylindrical portion 74J, thereby preventing the cylindrical portion 74J from falling out.

[0082] In this embodiment as well, when the plunger 50 descends in response to power being supplied to the electromagnetic coil 81, as shown in Figure 15, the upper end of the first cylindrical portion 71Ja abuts against the lower surface of the pilot valve body 51, and with the pilot passage 71Jf blocked, the main valve body 70J is pushed down and the inner cylindrical portion 74J shields the main valve seat 13b. As a result, the flow of fluid from the high-pressure passage to the low-pressure passage is blocked.

[0083] In response to the interruption of power supply to the electromagnetic coil 81, when the plunger 50 rises, the pilot passage 71Jf is opened, as shown in Figure 16. As a result, fluid flows from the pilot valve chamber PC to the low-pressure passage 13. The differential pressure between the upper space UC and the lower space LC causes the main valve body 70J to rise, thereby allowing fluid to flow from the high-pressure passage 12 to the low-pressure passage 13.

[0084] Solenoid valves come in two types: normally closed, which closes when the solenoid coil is not energized and opens when the solenoid coil is energized, and normally open, which opens when the solenoid coil is not energized and closes when the solenoid coil is energized. The solenoid valve of the present invention is applicable to both types.

[0085] It should be noted that the present invention is not limited to the embodiments described above. Within the scope of the present invention, any component of the embodiments described above can be modified.

[0086] This specification includes disclosures of the following inventions. (First aspect) A valve body having a main valve chamber inside, an inlet passage for introducing fluid into the main valve chamber, and an outlet passage for introducing the fluid out of the main valve chamber, and having a main valve port formed at the end of the outlet passage on the main valve chamber side, A main valve body that moves back and forth relative to the main valve opening to open and close the main valve opening, Plunger and, An electromagnetic drive device for driving the plunger includes a suction element fixed to the valve body for attracting the plunger, a sleeve fixed to the suction element for movably housing the plunger, and an electromagnetic coil arranged around the sleeve. Within the sleeve, a pilot valve chamber is formed between the plunger and the suction element, A pilot passage that penetrates the main valve body, selectively connecting the pilot valve chamber and the outflow passage, with the pilot valve chamber side end of the pilot passage being a pilot valve opening, A pressure equalization passage connecting the main valve chamber and the pilot valve chamber, A solenoid valve equipped with, The plunger is fixed to the main valve body side and comprises a pilot valve body which is an elastic body that opens and closes the pilot valve port in accordance with the movement of the plunger, The pilot valve body is positioned radially inward of the electromagnetic coil within the range of movement of the plunger. The main valve body has a shaft portion that extends toward the plunger side along the direction of movement of the plunger and in which the pilot passage is formed. A solenoid valve characterized by the following features.

[0087] (Second aspect) The shaft portion has a contact portion that, when the end of the shaft portion on the pilot valve body side is in contact with the pilot valve body, contacts the plunger to prevent the main valve body from moving any further toward the pilot valve body. A solenoid valve according to a first embodiment, characterized by the following:

[0088] (Third aspect) A first spring biases the plunger away from the suction element, The system includes a second spring that biases the main valve body toward the plunger relative to the suction element, A solenoid valve according to the first or second embodiment, characterized by the above.

[0089] (Fourth aspect) The aforementioned shaft portion has a protrusion on its outer circumferential surface, The second spring biases the protrusion toward the plunger. A third embodiment of a solenoid valve characterized by the following:

[0090] (Fifth aspect) The aforementioned shaft portion is composed of multiple valve stems fixed together. One of the plurality of valve stems has the protrusion, A third embodiment of a solenoid valve characterized by the following:

[0091] (Sixth aspect) A protruding member, which is a separate component from the shaft, is fixed to the aforementioned shaft portion. The protruding portion forming member forms the protruding portion. A solenoid valve according to any of the first to fifth embodiments, characterized by the above.

[0092] (Seventh aspect) The plunger is hollow, and a recess for holding the pilot valve body is formed on the suction side thereof, and the inside of the recess and the inside of the plunger are in communication via a communication passage. A solenoid valve according to any of the first to sixth embodiments, characterized by the above.

[0093] (Eighth aspect) The solenoid valve is detachably fixed to the structure, The aforementioned structure is The valve body is detachably inserted into a mounting hole, A high-pressure flow path opening into the aforementioned mounting hole, A low-pressure flow path opening into the aforementioned mounting hole, It has, With the valve body positioned in the mounting hole, The inflow passage is in communication with the high-pressure flow path, The outflow passage is in communication with the low-pressure flow path. A solenoid valve according to any of the first to seventh embodiments, characterized by the above.

[0094] (Ninth aspect) A solenoid valve from any one of the first to eighth embodiments, Structures and Equipped with, The aforementioned structure is The valve body is detachably inserted into a mounting hole, A high-pressure flow path opening into the aforementioned mounting hole, A low-pressure flow path opening into the aforementioned mounting hole, It has, With the valve body positioned in the mounting hole, The inflow passage is in communication with the high-pressure flow path, The outflow passage is in communication with the low-pressure flow path. Solenoid valve device. [Explanation of Symbols]

[0095] 1, 1G, 1H, 1I, 1J Solenoid valve 10, 10G valve body 11, 11G Main body 12 High-pressure flow path 13 Low-pressure channel 13b Main valve seat 40,40H suction element 41 Base 42 Cylinder part 50, 50A, 50B, 50C, 50D, 50H plungers 51 Pilot valve body 60, 61 Coil springs 70, 70F, 70H, 70I, 70J Main valve body 80 Coil Units 81 Electromagnetic coil 83 cases PC Pilot Valve Chamber LC lower space UC upper space VC Main Office

Claims

1. A valve body having a main valve chamber inside, an inlet passage for introducing fluid into the main valve chamber, and an outlet passage for introducing the fluid out of the main valve chamber, and having a main valve port formed at the end of the outlet passage on the main valve chamber side, A main valve body that moves back and forth relative to the main valve opening to open and close the main valve opening, Plunger and, An electromagnetic drive device for driving the plunger includes a suction element fixed to the valve body for attracting the plunger, a sleeve fixed to the suction element for movably housing the plunger, and an electromagnetic coil arranged around the sleeve. Within the sleeve, a pilot valve chamber is formed between the plunger and the suction element, A pilot passage that penetrates the main valve body, selectively connecting the pilot valve chamber and the outflow passage, with the pilot valve chamber side end of the pilot passage being a pilot valve opening, A pressure equalization passage connecting the main valve chamber and the pilot valve chamber, A solenoid valve equipped with, The plunger is fixed to the main valve body side and comprises a pilot valve body which is an elastic body that opens and closes the pilot valve port in accordance with the movement of the plunger, The pilot valve body is positioned radially inward of the electromagnetic coil within the range of movement of the plunger. The main valve body has a shaft portion that extends toward the plunger side along the direction of movement of the plunger and in which the pilot passage is formed. A solenoid valve characterized by the following features.

2. The shaft portion has a contact portion that, when the end of the shaft portion on the pilot valve body side is in contact with the pilot valve body, contacts the plunger to prevent the main valve body from moving any further toward the pilot valve body. The solenoid valve according to feature 1.

3. A first spring biases the plunger away from the suction element, A second spring biases the main valve body toward the plunger relative to the suction element, The solenoid valve according to feature 1.

4. The aforementioned shaft portion has a protrusion on its outer circumferential surface, The second spring biases the protrusion toward the plunger. The solenoid valve according to feature 3.

5. The aforementioned shaft portion is composed of multiple valve stems fixed together. One of the plurality of valve stems has the protruding portion. The solenoid valve according to feature 4.

6. A protruding member, which is a separate component from the shaft, is fixed to the aforementioned shaft portion. The protruding portion forming member forms the protruding portion. The solenoid valve according to feature 4.

7. The plunger is hollow, and a recess for holding the pilot valve body is formed on the suction side thereof, and the inside of the recess and the inside of the plunger are in communication via a communication passage. The solenoid valve according to feature 1.

8. The solenoid valve is detachably fixed to the structure, The aforementioned structure is The valve body is detachably inserted into a mounting hole, A high-pressure flow path opening into the aforementioned mounting hole, A low-pressure flow path opening into the aforementioned mounting hole, It has, With the valve body positioned in the mounting hole, The inflow passage is in communication with the high-pressure flow path, The outflow passage is in communication with the low-pressure flow path. The solenoid valve according to any one of claims 1 to 7.

9. A solenoid valve according to any one of claims 1 to 7, Structures and Equipped with, The aforementioned structure is The valve body is detachably inserted into a mounting hole, A high-pressure flow path opening into the aforementioned mounting hole, A low-pressure flow path opening into the aforementioned mounting hole, It has, With the valve body positioned in the mounting hole, The inflow passage is in communication with the high-pressure flow path, The outflow passage is in communication with the low-pressure flow path. Solenoid valve device.

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