Solenoid valve and method for assembling the same

Abstract

A solenoid valve (100) comprises: a cylindrical plunger (50) having a bottom (50a) in which a through-hole (50c) is formed; a valve shaft (60) that has a head part (62) and a shaft part (63), is slidably supported by the plunger along an axial direction, and opens and closes a valve seat (42), the head part being disposed inside the plunger, the shaft part being inserted into the through-hole and projecting from the bottom on the outside of the plunger toward the valve seat; and a first biasing member (52) having a valve closing spring part (52a) with one end contacting the bottom of the plunger, and the other end biasing, in a valve closing direction, the shaft part of the valve shaft projecting outside of the plunger.

Description

[Technical Field]

[0001] The present disclosure relates to a solenoid valve and a method for assembling the solenoid valve. [Background technology]

[0002] As an example of a solenoid valve, Japanese Patent Application Laid-Open Publication No. 2019-007572 discloses a pilot solenoid valve used in the refrigeration cycle of an automotive air conditioner, etc. Furthermore, as another example of a solenoid valve, International Publication No. 2019 / 135335 discloses a direct acting solenoid valve used as a dehumidification valve that throttles the refrigerant during dehumidification operation of an air conditioner, i.e., a dry valve.

[0003] For example, the solenoid valve of International Publication No. 2019 / 135335 includes a can, a plunger slidably housed inside the can, a valve stem slidably supported at the bottom of the plunger, and a valve body (i.e., a valve seat member) having a valve seat (i.e., a valve seat portion). A valve-closing spring made of a compression coil spring is disposed in a compressed state between the top of the valve stem inside the plunger and the ceiling of the can. A valve-opening spring (i.e., a plunger spring) made of a compression coil spring is disposed in a compressed state between the bottom of the plunger and the valve body.

[0004] The valve-closing spring in WO 2019 / 135335 constantly urges the valve stem so that the tip of the valve stem facing the valve seat (i.e., the valve body) is pressed against the valve seat, i.e., toward the valve-closing direction. The valve-opening spring in WO 2019 / 135335 urges the plunger in a direction away from the valve seat, i.e., toward the opposite side of the valve seat, toward the valve-opening direction.

[0005] In WO 2019 / 135335, when the solenoid valve is not energized, the plunger moves in the valve-opening direction due to the biasing force of the valve-opening spring. The valve stem supported by the plunger also moves in the valve-opening direction against the biasing force of the valve-closing spring. On the other hand, when the solenoid valve is energized, the electromagnetic attractive force generated by the solenoid causes the plunger to move in the valve-closing direction against the biasing force of the valve-opening spring, and the tip of the valve stem is pressed against the valve seat by the biasing force of the valve-closing spring.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-007572 Patent Document 2: International Publication No. 2019 / 135335 Summary of the Invention [Problem to be solved by the invention]

[0007] The valve-closing spring disposed inside the plunger in WO 2019 / 135335 is compressed between the top of the valve stem inside the plunger and the ceiling of the can in the solenoid valve after assembly as a product. However, the valve-closing spring is not compressed before assembly as a product. In other words, the axial length of the valve-closing spring before assembly of the solenoid valve is longer than the axial length of the valve-closing spring after assembly of the solenoid valve.

[0008] Therefore, before the plunger and the can are fitted together and before the product is assembled, the plunger and the valve-closing spring are not fixed together, so the valve-closing spring can easily come out from inside the plunger when assembling the solenoid valve, which increases the workload during the assembly of the solenoid valve.

[0009] The present disclosure provides a solenoid valve and a method for assembling the solenoid valve that can reduce the burden of assembly work. [Means for solving the problem]

[0010] The solenoid valve according to the first aspect comprises: a cylindrical plunger having a bottom with a through hole formed therein; a valve stem having a head and a shaft, the head of which is disposed inside the plunger and the shaft of which is inserted into the through hole and protrudes from the bottom of the plunger outside the plunger towards a valve seat, the valve stem being slidably supported by the plunger along the axial direction and opening and closing the valve seat; and a first biasing member having a valve-closing spring portion whose one end contacts the bottom of the plunger and whose other end urges the shaft of the valve stem protruding outside the plunger in a valve-closing direction.

[0011] In the solenoid valve according to the first aspect, the first biasing member having the valve-closing spring portion does not protrude from the inside to the outside of the plunger, as occurs in a solenoid valve in which the valve-closing spring is disposed between the plunger and the can, and as a result, the valve-closing spring is prevented from coming off from the inside of the plunger when assembling the solenoid valve.

[0012] In a second aspect, in the solenoid valve according to the first aspect, a step portion is provided on the stem portion of the valve stem, into which the other end side of the valve-closing spring portion is fitted.

[0013] In the second aspect, the step portion can improve the unity between the stem portion and the valve-closing spring portion.

[0014] In a third aspect, the solenoid valve according to the first or second aspect further includes a second biasing member having a valve-opening spring portion that biases the plunger in a valve-opening direction to open the valve seat when not energized.

[0015] In the third aspect, the valve-opening spring portion of the second biasing member can realize the valve-open state of the solenoid valve when not energized.

[0016] In a fourth aspect, in the solenoid valve according to the third aspect, the plunger-side end of the valve-closing spring portion of the first biasing member and the plunger-side end of the valve-opening spring portion of the second biasing member are continuous.

[0017] In the fourth aspect, a single biasing member is configured that functions as both a valve-closing spring and a valve-opening spring, eliminating the need for separate valve-closing and valve-opening springs, thereby reducing the number of parts required to assemble the solenoid valve.

[0018] In a fifth aspect, the solenoid valve of any of the first to fourth aspects further comprises a valve body having a main valve seat as a valve seat, and a main valve element disposed between the valve body and a valve stem, having a pilot valve seat opened and closed by the valve stem, and supported so as to be slidable along the axial direction, wherein the main valve element opens and closes the main valve seat by sliding along the axial direction.

[0019] In the fifth aspect, a pilot-operated solenoid valve that can reduce the burden of assembly work can be realized.

[0020] The method for assembling the solenoid valve according to the sixth aspect includes the steps of: placing the head of a valve stem, which has a head and a stem, inside a cylindrical plunger having a bottom with a through hole formed therein; and inserting the stem into the through hole in the bottom of the plunger, thereby slidably supporting the valve stem on the plunger along the axial direction with the stem protruding outward from the bottom outside the plunger; and integrating the valve stem, plunger, and biasing member by bringing one end of a valve-closing spring portion of the biasing member into contact with the bottom of the plunger and attaching the other end of the valve-closing spring portion to the stem of the valve stem protruding outside the plunger so that the stem is biased in the axial direction from the bottom of the plunger outward.

[0021] In the sixth aspect, the solenoid valve is assembled using a module in which the valve stem, plunger, and biasing member having the valve-closing spring are integrated, which makes it easier and faster to assemble the solenoid valve than when the valve stem, plunger, and valve-closing spring are handled separately. [Effects of the Invention]

[0022] According to the present disclosure, it is possible to provide a solenoid valve and a method for assembling a solenoid valve that can reduce the burden of assembly work. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view taken along line 1-1 in FIG. 2 illustrating a solenoid valve according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a side view illustrating the solenoid valve according to the embodiment. [Figure 3] 3 is a cross-sectional view illustrating the open state of the electromagnetic valve according to the embodiment, with a partial enlargement of the periphery of the valve seat. FIG. [Figure 4] 3 is a cross-sectional view illustrating the closed state of the electromagnetic valve according to the embodiment, with a partial enlargement of the periphery of the valve seat. FIG. [Figure 5] 1A to 1C are cross-sectional views illustrating a method of assembling the solenoid valve according to the present embodiment (part 1). [Figure 6] 5A to 5C are cross-sectional views for explaining a method of assembling the solenoid valve according to the present embodiment (part 2). [Figure 7] 5A to 5C are cross-sectional views for explaining a method of assembling the solenoid valve according to the present embodiment (part 3). [Figure 8] FIG. 10 is a cross-sectional view illustrating the open state of a solenoid valve according to a comparative example, with a partial enlargement of the periphery of a valve seat. [Figure 9] 10A and 10B are cross-sectional views for explaining a method of assembling a solenoid valve according to a comparative example (part 1). [Figure 10] 10 is a cross-sectional view (part 2) illustrating a method of assembling a solenoid valve according to a comparative example. [Figure 11] FIG. 4 is a cross-sectional view illustrating a solenoid valve according to a first modified example. [Figure 12] FIG. 10 is a cross-sectional view illustrating a solenoid valve according to a second modified example. [Figure 13] FIG. 10 is a cross-sectional view illustrating a solenoid valve according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0024] This embodiment will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each device or component, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, parts with different dimensional relationships and ratios are included between the drawings. Furthermore, unless otherwise specified in the specification, the number of each component element of the present disclosure is not limited to one, and multiple elements may be present.

[0025] <Solenoid valve configuration> First, the configuration of a solenoid valve 100 according to this embodiment will be described with reference to Figures 1 to 4. The solenoid valve 100 according to this embodiment is a pilot-type solenoid valve 100 used, for example, in the refrigeration cycle of an automotive air conditioner. Note that, although this embodiment has been described as an example in which the solenoid valve 100 is a pilot-type, the present disclosure is not limited to this, and the solenoid valve may be, for example, a direct-acting type.

[0026] As shown in FIG. 1, the solenoid valve 100 includes a valve body 30, a main valve element 40, a attractor 80, a plunger 50, a valve stem 60, a can 51, a solenoid 70, and a biasing member 52.

[0027] (Valve body) The valve body 30 is a cylindrical member having a main valve portion 10 therein. The valve body 30 can be made of a metal material such as aluminum, stainless steel, or brass. As shown in FIGS. 1 and 2 , the valve body 30 is formed with an inlet 31 and an outlet 32. A main valve chamber 33 is provided between the inlet 31 and the outlet 32, and is in communication with the inlet 31 and the outlet 32. The main valve portion 10 is formed in the main valve chamber 33. The solenoid valve 100 controls the opening and closing of the flow of fluid between the inlet 31 and the outlet 32 ​​by opening and closing the main valve portion 10.

[0028] The valve body 30 has a cylindrical portion formed inside the main valve chamber 33, which opens facing the underside of the main valve element 40 in FIG. 1. A main valve seat 35 is formed at the open end of the cylindrical portion of the valve body 30. In this embodiment, a main valve packing 40a is attached to the underside of the main valve element 40 in FIG. 1. The main valve unit 10 is composed of the main valve seat 35 and the main valve packing 40a. In this disclosure, the main valve packing 40a is not essential as long as it can close the main valve seat 35. In this embodiment, the main valve packing 40a is made of PTFE (polytetrafluoroethylene). The main valve packing 40a may also be made of a resin material other than rubber or PTFE.

[0029] A first diameter portion 30a that opens upward in Fig. 1 is formed in the side wall portion between the inlet 31 and the outlet 32 ​​of the valve body 30. A suction element 80 with the main valve body 40 disposed inside is inserted into the inside of the first diameter portion 30a. The suction element 80 is attached to the valve body 30 by fitting, screwing, or the like.

[0030] (Main valve body) The main valve element 40 has a main valve member 43 and a main valve packing 40a. The main valve member 43 can be made of a metal material such as aluminum, stainless steel, or brass. The main valve element 40 is supported inside the main valve chamber 33 of the valve body 30 so as to be slidable along the axial direction C. The main valve section 10 is disposed below the main valve element 40 in FIG. 1, i.e., on one side in the sliding direction.

[0031] The pilot valve portion 20 is disposed above the main valve body 40 in FIG. 1, that is, on the other side in the sliding direction.

[0032] In this embodiment, a packing portion that opens and closes the main valve seat 35 is provided on the lower surface of the main valve packing 40a of the main valve body 40, and a pilot valve seat 42 is provided on the upper surface of the main valve packing 40a. The pilot valve seat 42 is opened and closed by a pilot valve portion 20 formed on the tip end of the shaft portion 63 (i.e., the tip end on the opposite side from the head portion 62).

[0033] In the present disclosure, as long as the pilot valve seat 42 can be closed, the pilot valve packing, which is the portion where the upper surface side pilot valve seat 42 is provided in FIG. 1, is not essential. A configuration may be adopted in which the pilot valve seat portion is formed directly on the main valve member 43 and the packing portion on the lower surface side is attached to the main valve member 43. Of course, the packing portion that opens and closes the main valve seat 35 on the lower surface side and the portion where the upper surface side pilot valve seat 42 is provided (in other words, the pilot valve packing) may be attached to the main valve member 43 as separate members, respectively.

[0034] The pilot valve seat 42 of the present embodiment corresponds to the valve seat of the present disclosure. Further, the main valve seat 35 of the present embodiment corresponds to the valve seat of the present disclosure when a direct-acting solenoid valve is configured.

[0035] As shown in FIG. 3, a pilot passage 45 extending along the axial direction C is formed in the central portion of the main valve body 40 in the vertical direction. A pilot valve seat 42 is provided at the upper end of the pilot passage 45 in FIG. 3.

[0036] A cylindrical main valve member 43 is fitted on the outer surface of the main valve packing 40a. A pressure equalizing hole 44, which is a through hole extending along the axial direction C, is formed in the main valve packing 40a. The pressure equalizing hole 44 communicates the main valve chamber 33 and the pilot valve chamber 34. The sum of the cross-sectional area A in the cross-sectional plane orthogonal to the axial direction C of the pressure equalizing hole 44 and the cross-sectional area B of the gap between the inner surface of the large diameter portion 82 and the outer peripheral surface of the main valve body 40 is smaller than the cross-sectional area D of the pilot passage 45 (that is, A + B < D). By the pressure equalizing hole 44, the main valve chamber 33 and the pilot valve chamber 34 are equalized in pressure, and as a result, the main valve body 40 can be easily opened and closed.

[0037] (Armature) The armature 80 is disposed between the valve body 30 and the plunger 50. The armature 80 drives the plunger 50 by the operation of the solenoid 70. In the present disclosure, a member that drives the plunger 50 by suction and supports the main valve body

[0038] The aspirator 80 is a cylindrical member. The aspirator 80 of this embodiment is made of, for example, magnetic stainless steel. Note that in the present disclosure, the aspirator is not limited to magnetic stainless steel, and any material including a magnetic material can be used.

[0039] An insertion hole 80a extending along the axial direction C is formed in the center of the suction element 80 in the vertical direction in Figure 3. The valve stem 60 is disposed inside the insertion hole 80a. The suction element 80 has a small diameter portion 81 located on the upper side in Figure 1 and a large diameter portion 82 located on the lower side.

[0040] 1 is attached to the outer surface of the small diameter portion 81. At the position of the large diameter portion 82, the attractor 80 is fixed to the first diameter portion 30a of the valve body 30 by fitting or screwing.

[0041] An O-ring 83 is disposed on the outer surface of the lower part of the large diameter portion 82 of the suction element 80 in FIG. 1. The O-ring 83 seals the gap between the suction element 80 and the valve body 30. A main valve element accommodating portion 82a, which is a cylindrical space, is formed inside the large diameter portion 82 of the suction element 80. The main valve element 40 is supported inside the main valve element accommodating portion 82a so that it can slide along the axial direction C.

[0042] The main valve body accommodating portion 82a is divided into upper and lower portions by the main valve body 40, so that the space of the main valve body accommodating portion 82a is 3 The lower part of the inside is defined as the main valve chamber 33. 3 The upper inner portion is defined as a pilot valve chamber 34 .

[0043] Inside the large-diameter portion 82 of the attractor 80, the valve body spring 46, which is a coil spring, is arranged along the inner surface of the large-diameter portion 82. The upper end of the valve body spring 46 in FIG. 3 contacts the lower surface of the main valve member 43, and the lower end of the valve body spring 46 is supported by a portion that protrudes inward from the inner edge of the lower end of the large-diameter portion 82. The valve body spring 46 biases the main valve body 40 upward in FIG. 3, i.e., in a direction away from the main valve seat 35.

[0044] In the present embodiment, the stepped structure of the aspirator 80 is achieved by integrally configuring the small diameter portion 81 and the large diameter portion 82 using a single cylindrical member, but the present disclosure is not limited to this. For example, the small diameter portion and the large diameter portion may be made of separate members, and the small diameter portion and the large diameter portion may be joined together. In the present disclosure, it is sufficient for the aspirator to be able to drive the plunger 50 by energizing the solenoid 70.

[0045] An electrical current control device (not shown) is connected to the attractor 80. When the electrical current control device energizes the solenoid 70, the attractor 80 and the plunger 50 are magnetized. An attractive force that exceeds the biasing force of the valve-opening spring portion 52b of the biasing member 52 is generated in the magnetized attractor 80. The generated attractive force attracts the plunger 50 downward in FIG. 1, i.e., toward the attractor 80.

[0046] (plunger) The plunger 50 is a cylindrical member having a bottom 50a and a sidewall 50b. The bottom 50a of the plunger 50 is disposed on the side of the pilot valve seat 42. However, this disclosure is not limited to this, and the position of the bottom is not limited to the side of the valve seat (i.e., the pilot valve seat 42 and the main valve seat 35 in this embodiment) and can be set at any position. A through-hole 50c is formed in the bottom 50a. The plunger 50 in this embodiment is made of, for example, magnetic stainless steel. However, this disclosure is not limited to this, and the plunger may be made of any magnetic material. The plunger 50 is slidably disposed inside the can 51 along the axial direction C by operation of the solenoid 70. A horizontal hole 50e is formed in the sidewall of the plunger 50 in FIG. 3.

[0047] (Can) The can 51 is a cylindrical member having a ceiling and a side wall. The end of the side wall of the can 51 opposite the ceiling is attached to the suction element 80. The lower end of the cylindrical member can 51 in FIG. 1 is open. The lower end of the cylindrical member can 51 in FIG. 1 can be fixed to the suction element 80 by appropriate means such as crimping or welding. The can 51 houses the plunger 50 inside.

[0048] (solenoid) The solenoid 70 is fitted onto the outer peripheral surface of the can 51. The solenoid 70 has a coil 70a, a bobbin 70b, and a yoke 70c. The coil 70a is wound around the bobbin 70b. The yoke 70c is made of a magnetic material. The yoke 70c surrounds the bobbin 70b. In addition, on the lower side in FIG. 1, i.e., on the side of the yoke 70c facing the valve body 30, a protrusion 70d is formed that protrudes outward on the side opposite the can 51.

[0049] A through hole 70d1 is formed in the protruding portion 70d. Furthermore, a female threaded portion 30d is formed coaxially at a position overlapping with the through hole 70d1 of the protruding portion 70d at the top of the valve body 30 in FIG. 1. A male thread 71 is screwed into the through hole 70d1 of the protruding portion 70d of the solenoid 70 and into the female threaded portion 30d of the valve body 30, whereby the solenoid 70 is fixed in a state where it is pressed against the valve body 30. The attractor 80 is fixed to the first diameter portion 30a of the valve body 30 by a male thread formed on the outer circumferential surface of the large diameter portion 82.

[0050] (valve stem) The valve stem 60 has a head 62 and a shaft portion 63. The head 62 of the valve stem 60 is disposed inside the plunger 50. The head 62 has a larger diameter than the shaft portion 63 in a radial direction perpendicular to the axial direction C in FIG. 3 . The diameter of the shaft portion 63 is slightly smaller than the diameter of the through-hole 50c of the plunger 50. Therefore, when inserted into the through-hole 50c of the plunger 50, the shaft portion 63 protrudes from the bottom portion 50a outside the plunger 50 toward the valve seat. The valve stem 60 is supported by the plunger 50 so as to be slidable along the axial direction C. The pilot valve seat 42 is opened and closed by the valve stem 60. The pilot valve portion 20 is formed at the tip of the shaft portion 63 (i.e., the tip opposite the head 62).

[0051] (Stepped part) A step portion 63a is formed on the shaft portion 63 of the valve shaft 60. In this embodiment, the step portion 63a is a ring-shaped groove formed on the circumferential surface of the shaft portion 63. The other end side of the valve-closing spring portion 52a, which will be described later, is fitted into the step portion 63a. Note that in this disclosure, the step portion 63a is not essential. Also, in this embodiment, a ring-shaped groove formed on the circumferential surface of the shaft portion 63 is exemplified as the step portion 63a, but in this disclosure, the shape of the step portion is not limited to this.

[0052] In the present disclosure, for example, the stepped portion may be a protrusion that protrudes partially from the circumferential surface of the shaft portion 63. Furthermore, in the present disclosure, the stepped portion does not have to be a continuous ring shape that extends over the entire circumferential direction of the circumferential surface of the shaft portion 63. For example, a plurality of grooves or protrusions serving as stepped portions may be intermittently provided at intervals in the circumferential direction on the circumferential surface of the shaft portion 63. In the present disclosure, the shape of the stepped portion may be changed as appropriate as long as it is possible to attach the end of the valve-closing spring.

[0053] (biasing member) The biasing member 52 of this embodiment is, for example, a metal coil spring. However, the biasing member of the present disclosure is not limited to this and may be made of a material other than metal. The biasing member 52 of this embodiment has a valve-closing spring portion 52a located on the valve stem 60 side in FIG. 3 and a valve-opening spring portion 52b located on the suction element 80 side in FIG. 3.

[0054] In this embodiment, the end of the valve-closing spring portion 52a of the biasing member 52 on the plunger 50 side is continuous with the end of the valve-opening spring portion 52b on the plunger 50 side. Specifically, the valve-closing spring portion 52a and the valve-opening spring portion 52b are realized by a single coil spring. That is, the biasing member 52 of this embodiment includes both the first biasing member and the second biasing member of the present disclosure.

[0055] (valve closing spring) The valve-closing spring portion 52a, which is located on the valve stem 60 side in Figure 3, is disposed between the valve body 30 and the plunger 50. Specifically, one end of the valve-closing spring portion 52a contacts the bottom portion 50a of the plunger 50. The other end of the valve-closing spring portion 52a is attached to a stepped portion 63a of the shaft portion 63 of the valve stem 60, which protrudes outside the plunger 50. The valve-closing spring portion 52a biases the shaft portion 63 in a valve-closing direction toward the pilot valve seat 42 in the axial direction C.

[0056] In the present disclosure, "one end side" means a region including the end face and peripheral surface at the "one end," and "the other end side" means a region including the end face and peripheral surface at the "other end." In other words, when the valve-closing spring part comes into contact with or fits into another member at the end position, the one end side or the other end side of the valve-closing spring part is not limited to, for example, just the end face, but also includes the part at the end of the valve-closing spring part that comes into contact with or fits into another member.

[0057] The first biasing member of the present disclosure is not limited to a coil spring, as long as it is a member that can bias the tip of the shaft portion 63 in the valve closing direction toward the valve seat. Also, in the present disclosure, a recess into which one end of the valve closing spring portion 52a fits may be provided in the bottom portion 50a of the plunger 50.

[0058] The valve-opening spring portion 52b, which is located on the side of the suction element 80 in FIG. 3, is disposed between the valve body 30 and the plunger 50. Specifically, one end of the valve-opening spring portion 52b contacts the bottom portion 50a of the plunger 50. The other end of the valve-opening spring portion 52b is disposed on the upper surface of a mounting portion 81a that protrudes toward the valve stem 60 on the inner wall surface of the insertion hole 80a of the suction element 80. Note that the mounting portion 81a is not essential in the present disclosure, and the mounting structure of the one end of the valve-opening spring portion 52b to the suction element 80 can be modified as appropriate. For example, the bottom portion 50a of the plunger 50 may be provided with a recess into which the one end of the valve-opening spring portion 52b fits.

[0059] When the solenoid valve 100 is not energized, the valve-opening spring portion 52b urges the plunger 50 in a valve-opening direction in which the valve stem 60 moves away from the pilot valve seat 42 in the axial direction C, against the urging force of the valve-closing spring portion 52a. The magnitude of the urging force of the valve-opening spring portion 52b is set to an extent that, when the solenoid valve 100 is not energized, the plunger 50 and the valve stem 60 supported by the plunger 50 can move in a direction away from the pilot valve seat 42 against the urging force of the valve-closing spring portion 52a. The pilot valve seat 42 is opened by the valve-opening spring portion 52b.

[0060] In one method for producing the biasing member 52 of this embodiment, for example, a cylindrical coil spring is prepared. Specifically, a coil spring is prepared having two spring portions: a spring portion included in an area located on one side of the center along the axial direction C, and a spring portion included in an area located on the other side of the center. The diameter of the spring portion included in one area gradually decreases from the boundary between the two areas toward the surface on one end. The diameter of the spring portion included in the other area is approximately the same between the boundary between the two areas and the surface on the other end.

[0061] The biasing member 52 according to this embodiment can be fabricated by pressing the spring portion included in one region into the spring portion included in the other region. In FIG. 3, the boundary between one region and the other region forms the upper end of the valve-closing spring portion 52a and the upper end of the valve-opening spring portion 52b. The boundary between one region and the other region contacts the lower surface of the bottom portion 50a of the plunger 50.

[0062] <Solenoid valve operation> Next, the operation of the solenoid valve 100 will be described separately for the open state when not energized and the closed state when energized.

[0063] (Open state when not energized) When the coil 70a of the solenoid 70 is not energized, no attractive force is generated in the attractor 80. Therefore, the urging force of the valve-opening spring portion 52b of the urging member 52 presses the plunger 50 upward in FIG. 3 inside the can 51, resulting in the open state of the pilot valve portion 20. Also, the urging force of the valve body spring 46 presses the main valve element 40 upward in FIG. 3 inside the main valve chamber 33, resulting in the open state of the main valve portion 10.

[0064] When the solenoid valve 100 is in the open state and a compressor (not shown) connected to the solenoid valve 100 is operated, a high-temperature, high-pressure refrigerant fluid, for example, flows in through the inlet 31 and through the outlet 32 ​​via the main valve section 10, which is open inside the main valve chamber 33.

[0065] (Closed state when energized) Next, when the solenoid 70 is energized, the attractor 80 and the plunger 50 are magnetized, and an electromagnetic attractive force is generated between the attractor 80 and the plunger 50. As shown in Figure 4, the generated electromagnetic attractive force pulls the plunger 50 toward the pilot valve seat 42 against the biasing force of the valve-opening spring portion 52b of the biasing member 52.

[0066] The plunger 50 integrally supports the valve stem 60, so that the valve stem 60 slides inside the can 51 along the axial direction C in conjunction with the movement of the plunger 50. As a result, the pilot valve packing (not shown) of the valve stem 60 comes into contact with the pilot valve seat 42 of the main valve body 40, resulting in the pilot valve portion 20 being in a closed state. In other words, the pilot passage 45 is closed.

[0067] When the pilot passage 45 is closed, only the pressure equalizing hole 44 connects the pilot valve chamber 34 and the main valve chamber 33. As a result, the pressure difference between the pilot valve chamber 34 and the main valve chamber 33 is lost.

[0068] Furthermore, the plunger 50 causes the valve stem 60 to push the main valve element 40 downward in Fig. 4, and as a result, when the main valve element 40 reaches the lowest point within its range of downward movement, the main valve packing 40a of the main valve element 40 comes into contact with the main valve seat 35 formed inside the valve body 30. Note that Fig. 4 illustrates a state in which the plunger 50 has moved further downward than the base of the head 62 of the valve stem 60, resulting in the formation of a small gap between the upper surface of the bottom 50a of the plunger 50 and the lower surface of the head 62 of the valve stem 60.

[0069] The contact of the main valve element 40 with the main valve seat 35 establishes a closed state of the main valve unit 10. As a result, the refrigerant flow path is closed, and the flow of refrigerant from the inlet 31 to the outlet 32 ​​stops. When the solenoid 70 is de-energized, the electromagnetic attraction force of the attractor 80 by the solenoid 70 disappears. As a result, as shown in FIG. 1, the plunger 50 is pushed in a direction away from the pilot valve seat 42 (i.e., upward in FIG. 1) by the biasing force of the valve-opening spring portion 52b of the biasing member 52. Furthermore, the valve stem 60 also moves together with the plunger 50 in a direction away from the pilot valve seat 42.

[0070] Then, the pilot valve packing (not shown) at the tip of the valve stem 60 moves away from the pilot valve seat 42 of the main valve element 40, thereby establishing an open state for the pilot valve portion 20. As a result, the pilot valve chamber 34 communicates with the outlet 32 ​​via the pilot passage 45 of the main valve element 40. As a result, the pressure in the pilot valve chamber 34 shifts from high to low pressure. As a result, the main valve element 40 moves upward in FIG. 1, and the main valve packing 40a of the main valve element 40 moves away from the main valve seat 35, thereby establishing an open state for the valve body 30.

[0071] <How to assemble a solenoid valve> Next, a method of assembling the solenoid valve 100 according to this embodiment will be described with reference to FIGS.

[0072] (Creating the first module) First, the valve stem 60 is supported by the plunger 50 so as to be slidable along the axial direction C. Specifically, as shown in Fig. 5, the stem portion 63 of the valve stem 60 is caused to protrude from the bottom portion 50a of the plunger 50. The head portion 62 of the valve stem 60 is disposed inside the cylindrical plunger 50.

[0073] The other end side (i.e., the lower end side in FIG. 5) of the valve-closing spring portion 52a is attached to a stepped portion 63a of the shaft portion 63 of the valve shaft 60 that protrudes outward from the plunger 50, with the shaft portion 63 being biased in a direction from the bottom portion 50a of the plunger 50 outward in the axial direction C. One end side (i.e., the upper end side in FIG. 5) of the valve-closing spring portion 52a of the biasing member 52 contacts the bottom portion 50a of the plunger 50. As a result, the plunger 50, the shaft portion 63, and the biasing member 52 are assembled together.

[0074] By attaching the valve closing spring portion 52a to the valve stem 60, a first module 91 is formed in which the valve stem 60, the plunger 50, and the biasing member 52 are integrated. The first module 91 of this embodiment corresponds to the module of the present disclosure.

[0075] (Attaching the first module to the can and main valve body) 6, with the plunger 50, the shaft portion 63, and the biasing member 52 assembled, the first module 91 is inserted into the insertion hole 80a of the suction element 80. The plunger 50 of the first module 91 is fitted inside the cylindrical can 51 so as to be slidable along the axial direction C. The side wall of the can 51 is attached to the suction element 80 with the shaft portion 63 of the valve stem 60 of the first module 91 protruding from the plunger 50 facing the pilot valve seat 42 of the main valve body 40.

[0076] Specifically, for example, with the can 51, the first module 91, and the main valve body 40 all arranged coaxially, the step of fitting the plunger 50 of the first module 91 into the can 51 and the step of attaching the side wall of the can 51 to the suction element 80 can be carried out simultaneously. Then, with the can 51, the first module 91, and the suction element 80 overlapping each other, the joint between the lower end of the side wall of the can 51 and the suction element 80 is fixed by welding or the like. By fixing, the second module 92 is formed, in which the can 51, the first module 91, and the suction element 80 including the main valve body 40 are integrated.

[0077] In the present disclosure, the method of fixing the can 51 and the main valve body 40 is not limited to welding, and any method can be used, such as bonding using an adhesive. In addition, in the present disclosure, it is not essential that the step of fitting the plunger 50 of the first module 91 into the can 51 and the step of attaching the side wall of the can 51 to the suction element 80 be performed simultaneously. In the present disclosure, the step of fitting the plunger 50 of the first module 91 into the can 51 and the step of attaching the side wall of the can 51 to the suction element 80 may be performed sequentially, so that one of them is performed before the other is performed.

[0078] Furthermore, the present disclosure is not limited to this, and the order in which the step of fitting the plunger 50 of the first module 91 into the can 51 and the step of attaching the side wall of the can 51 to the suction element 80 are performed may be either first or later.

[0079] (Installation of the second module and solenoid) Next, the attractor 80 of the formed second module 92 is fitted inside the main valve chamber 33 of the valve body 30. The solenoid 70 is disposed outside the can 51. The solenoid 70 and the valve body 30 are then connected together. Specifically, the solenoid 70 and the valve body 30 are screwed together using the through-hole 70d1 of the protruding portion 70d, the female thread portion 30d of the valve body 30, and the male thread 71. Note that in the present disclosure, the method of connecting the solenoid 70 and the valve body 30 is not limited to screwing, and any method such as welding can be used.

[0080] The solenoid valve 100 according to this embodiment illustrated in FIG. 1 can be manufactured by the method for assembling the solenoid valve 100 including the above-described series of steps.

[0081] (Comparative Example) 8, in the case of a solenoid valve 100Z according to the comparative example, the valve-opening spring 52Z disposed between the valve body 30 and the plunger 50 does not have a valve-closing spring portion as in the present embodiment. The length of the valve-opening spring 52Z of the comparative example along the axial direction C is the same as the length of the biasing member 52 of the present embodiment.

[0082] In addition, in the solenoid valve 100Z according to the comparative example, a valve-closing spring 53, which is a separate member from the valve-opening spring 52Z, is disposed inside the plunger 50 between the ceiling portion of the can 51 and the head 62 of the valve stem 60. In addition, in the comparative example, a step portion 63a is not formed on the stem portion 63 of the valve stem 60. Other configurations in the comparative example are similar to the members with the same names in the present embodiment illustrated in Figures 1 to 7, and therefore redundant explanations will be omitted.

[0083] As shown in Fig. 9, when assembling the solenoid valve 100Z according to the comparative example, the length along the axial direction C of all the components required for assembly is longer than the length of the solenoid valve 100 according to the present embodiment illustrated in Fig. 6. For this reason, when assembling the solenoid valve 100Z according to the comparative example, the valve-closing spring 53 that protrudes outward is likely to come into contact with other components, or the valve-closing spring 53 is likely to come out from inside the plunger 50.

[0084] 10, in the comparative example, even before the lower end of the side wall of the can 51 and the attractor 80 are fixed, the valve-closing spring 53 protrudes from the inside to the outside of the plunger 50. For this reason, the length along the axial direction C of all the components required for assembly is longer than the length of the solenoid valve 100 according to this embodiment illustrated in FIG. 7. As a result, in the fitted state before fixing, the can 51 is likely to float relative to the attractor 80, that is, a gap G is likely to occur between the can 51 and the attractor 80.

[0085] For this reason, in the comparative example, it is difficult to stably support each component when fixing the can 51 and the attractor 80. Furthermore, in order to stably support each component, a relatively complicated jig corresponding to the overall length of the components is required.

[0086] (Action and effect) In this embodiment, the biasing member 52 having the valve-closing spring portion 52a is disposed between the valve body 30 and the plunger 50. One end of the valve-closing spring portion 52a contacts the bottom portion 50a of the plunger 50, and the other end of the valve-closing spring portion 52a is attached to the shaft portion 63 of the valve shaft 60 that protrudes outside the plunger 50. The valve-closing spring portion 52a biases the shaft portion 63 in the valve-closing direction.

[0087] Therefore, unlike the comparative example, the valve-closing spring 53 does not protrude from the inside to the outside of the plunger 50. As a result, when assembling the solenoid valve 100, the valve-closing spring is prevented from coming out from the inside of the plunger 50. Therefore, the burden of assembling the solenoid valve 100 can be reduced.

[0088] Furthermore, in this embodiment, the biasing member 52 having the valve-closing spring portion 52a does not protrude from the inside to the outside of the plunger 50, thereby reducing the length of the entire components required to assemble the solenoid valve 100 along the axial direction C. Therefore, unlike the comparative example, it is easy to stably support the components during assembly, and a relatively complicated jig corresponding to the length of the entire components is not required. This makes it possible to assemble the solenoid valve 100 more easily.

[0089] Furthermore, in this embodiment, the biasing member 52 having the valve-closing spring portion 52a is disposed between the attractor 80 on the valve body side and the plunger 50. In other words, the biasing member 52 is not disposed between the plunger 50 and the can 51. Here, in the case of a solenoid valve in which the valve-closing spring is disposed between the plunger 50 and the can 51, for example, repeated movement of the plunger 50 can easily cause the valve-closing spring to become caught at the contact portion between the can 51 and the valve-closing spring, and burrs and the like can easily fall off from the part due to rubbing.

[0090] For example, if the resulting burrs pass through the horizontal hole 50e of the plunger 50 in Figure 3 and enter between the side wall of the plunger 50 and the can 51 as foreign matter, it will interfere with the operation of the solenoid valve 100. In order to prevent the valve-closing spring from getting caught and the occurrence of burrs, it is possible to consider measures to improve the machining accuracy of parts such as the can 51 and the valve-closing spring portion 52a, but this would impose a burden on manufacturing.

[0091] However, in this embodiment, the biasing member 52 having the valve-closing spring portion 52a is disposed between the attractor 80 on the valve body side and the plunger 50, thereby preventing the valve-closing spring from getting caught and generating burrs at the contact portion between the can 51 and the valve-closing spring. Therefore, the burden of improving the machining accuracy of the parts is not incurred, and the burden of machining the parts can be reduced.

[0092] Furthermore, in this embodiment, the solenoid valve 100 is provided with a step portion 63a into which the other end side of the valve-closing spring portion 52a fits onto the shaft portion 63 of the valve shaft 60. The step portion 63a can improve the unity between the shaft portion 63 and the valve-closing spring portion 52a.

[0093] Furthermore, in the present embodiment, the solenoid valve 100 further includes a valve-opening spring portion 52b in the biasing member 52 disposed between the valve body 30 and the plunger 50. The valve-opening spring portion 52b opens the pilot valve seat 42 by biasing the plunger 50 in the valve-opening direction when not energized. Therefore, the valve-opening spring portion 52b of the biasing member 52 can realize the valve-open state of the solenoid valve 100 when not energized.

[0094] Furthermore, in this embodiment, the end of the valve-closing spring portion 52a on the plunger 50 side and the end of the valve-opening spring portion 52b on the plunger 50 side of the biasing member 52 are continuous. In other words, a single biasing member 52 is configured that has the functions of both a valve-closing spring and a valve-opening spring, so there is no need to prepare separate valve-closing and valve-opening springs. This reduces the number of parts required to assemble the solenoid valve 100.

[0095] The solenoid valve 100 according to this embodiment further includes a valve body 30 having a main valve seat 35, and a main valve element 40 that is disposed between the valve body 30 and a valve stem 60, has a pilot valve seat 42 that is opened and closed by the valve stem 60, and is supported so as to be slidable along the axial direction C. The main valve element 40 slides along the axial direction C to open and close the main valve seat 35. Therefore, according to this embodiment, a pilot-operated solenoid valve that can reduce the burden of assembly work can be realized.

[0096] Furthermore, in this embodiment, the solenoid valve 100 is assembled using a first module 91 in which the valve stem 60, the plunger 50, and the biasing member 52 having the valve-closing spring portion 52a are integrated together. Therefore, the solenoid valve 100 can be assembled more easily and quickly than when the valve stem, the plunger, and the valve-closing spring are handled separately.

[0097] <Other embodiments> Although the present disclosure has been described with reference to the above disclosed embodiments, the descriptions and drawings forming a part of this disclosure should not be understood to limit the present disclosure.

[0098] (First Modification) For example, in the present disclosure, as in the solenoid valve 100A according to the first modified example illustrated in FIG. 11, the position where the other end side of the valve closing spring portion 52a of the biasing member 52A on the shaft portion 63 of the valve shaft 60 is fitted may be brought close to the pilot valve seat 42.

[0099] 11, the position at which the other end of the valve-closing spring portion 52a on the shaft portion 63 of the valve shaft 60 is fitted is below the lower end of the valve-opening spring portion 52b. The other configurations in the first modified example are the same as the members with the same names in the present embodiment illustrated in FIGS. 1 to 7, and therefore redundant explanations will be omitted.

[0100] In the first modified example, as in the case of this embodiment, the burden of assembling the solenoid valve 100A can be reduced. Furthermore, in the first modified example, the position where the other end side of the valve-closing spring portion 52a of the biasing member 52A on the shaft portion 63 of the valve shaft 60 is fitted is brought closer to the pilot valve seat 42, which makes it easier to increase the biasing force of the valve-closing spring portion 52a. Furthermore, when attaching the valve-closing spring portion 52a to the step portion 63a, the insertion distance of the valve-closing spring portion 52a into the valve shaft 60 is short, resulting in good workability. Other effects of the first modified example are the same as in the case of this embodiment.

[0101] (Second Modification) In addition, in the present embodiment, the case where the diameters of the coil springs included in the valve-opening spring portion 52b are all substantially the same has been exemplified, but the present disclosure is not limited to this. 2 The valve-opening spring portion 52b may have a conical shape, like the biasing member 52B of the solenoid valve 100B according to the modified example. The other configurations of the second modified example are the same as those of the same-named members in the present embodiment illustrated in Figures 1 to 7, and therefore redundant explanations will be omitted.

[0102] In the second modified example, as in the present embodiment, the workload for assembling the solenoid valve 100B can be reduced. Furthermore, in the second modified example, the diameter of the coil spring included in the valve-opening spring portion 52b gradually increases from the bottom 50a side of the plunger 50 toward the pilot valve seat 42 side. Therefore, compared to when the diameter of the coil spring is the same, it is easier to ensure the distance between the lower end of the valve-closing spring portion 52a and the lower end of the valve-opening spring portion 52b, and as a result, interference between the valve-closing spring portion 52a and the valve-opening spring portion 52b can be suppressed. This allows the second modified example to ensure a greater degree of freedom in the spring load setting than the other examples. Furthermore, in the second modified example, it is easier to increase the biasing force of the valve-opening spring portion 52b. Other advantages of the second modified example are similar to those of the present embodiment.

[0103] (Third Modification) Furthermore, although the present embodiment exemplifies a case in which the valve-closing spring portion 52a and the valve-opening spring portion 52b are connected within the biasing member 52, which is a single coil spring, the present disclosure is not limited to this. In the present disclosure, as in the third modified example illustrated in Fig. 13, the first biasing member 52C1 having the valve-closing spring portion and the second biasing member 52C2 having the valve-opening spring portion may be separate members. The first biasing member 52C1 and the second biasing member 52C2 in the third modified example can each be made of a separate coil spring, similar to the biasing member 52 of the present embodiment.

[0104] In the third modified example, a partition 54 that protrudes toward the pilot valve seat 42 is provided on the lower surface of the bottom 50a of the plunger 50 in Fig. 13. The partition 54 is arranged in a ring shape around the through-hole 50c of the plunger 50. The partition 54 arranged in a ring shape may be a single ring-shaped partition, or multiple partitions may be arranged in a ring shape with spaces between them.

[0105] In the present disclosure, a recess into which one end of the first biasing member 52C1 fits may be provided in the bottom portion 50a of the plunger 50. In the present disclosure, a recess into which one end of the second biasing member 52C2 fits may be provided in the bottom portion 50a of the plunger 50. The recess into which the end of the biasing member fits may be provided instead of or in combination with the partition portion.

[0106] The partition 54 allows the upper ends of the first and second biasing members 52C1 and 52C2 in Fig. 13 to come into contact with the bottom 50a of the plunger 50 separately without coming into contact with each other. The other configurations in the third modified example are the same as those of the same members in the present embodiment illustrated in Figs. 1 to 7, and therefore redundant description will be omitted.

[0107] In the third modified example, as in the present embodiment, the burden of assembling the solenoid valve 100C can be reduced. Furthermore, in the third modified example, the first biasing member 52C1 having the valve-closing spring portion and the second biasing member 52C2 having the valve-opening spring portion are separate members, so there is no need to connect the valve-closing spring portion and the valve-opening spring portion within a single coil spring. Other effects of the third modified example are similar to those of the present embodiment.

[0108] As described above, the present disclosure includes various embodiments not described in this specification, and the technical scope of the present disclosure is defined only by the invention-specific matters of the claims that are appropriate from the above explanation.

[0109] The disclosure of Japanese Patent Application No. 2022-203637, filed on December 20, 2022, is incorporated herein by reference in its entirety.

[0110] Furthermore, all publications, patent applications, and technical standards mentioned in this specification are incorporated by reference herein to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. a cylindrical plunger having a bottom portion with a through hole formed therein; a valve stem having a head and a stem, the head being disposed inside the plunger, the stem being inserted into the through-hole and protruding from the bottom outside the plunger toward the valve seat, the valve stem being slidably supported by the plunger along the axial direction and opening and closing the valve seat; a first biasing member having a valve-closing spring portion, one end of which contacts the bottom portion of the plunger and the other end of which protrudes outward from the plunger, for biasing the stem portion of the valve stem in a valve-closing direction; A solenoid valve.

2. a step portion into which the other end side of the valve closing spring portion is fitted is provided on the shaft portion of the valve shaft; The solenoid valve according to claim 1 .

3. a second biasing member having a valve-opening spring portion that biases the plunger in a valve-opening direction to open the valve seat when not energized; The solenoid valve according to claim 1 or 2, further comprising:

4. an end portion of the valve-closing spring portion of the first biasing member on the plunger side and an end portion of the valve-opening spring portion of the second biasing member on the plunger side are continuous with each other; The solenoid valve according to claim 3.

5. a valve body having a main valve seat as the valve seat; a main valve element disposed between the valve body and the valve stem, the main valve element having a pilot valve seat that is opened and closed by the valve stem, and supported slidably along the axial direction; Further provided with The main valve element slides along the axial direction to open and close the main valve seat.

3. The solenoid valve according to claim 1 or 2.

6. a step of arranging a valve stem having a head and a stem portion inside a cylindrical plunger having a bottom portion with a through hole formed therein, and inserting the stem portion into the through hole in the bottom portion of the plunger, thereby slidably supporting the valve stem on the plunger along the axial direction with the stem portion protruding outward from the bottom portion outside the plunger; a step of integrating the valve stem, the plunger, and the biasing member by bringing one end side of the valve-closing spring portion of the biasing member into contact with the bottom portion of the plunger and attaching the other end side of the valve-closing spring portion to the stem portion of the valve stem that protrudes outward from the plunger so that the stem portion is biased in a direction from the bottom portion of the plunger toward the outside in the axial direction; A method for assembling a solenoid valve, comprising:

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