Valve device, electric valve, and refrigeration cycle system

Abstract

Provided is a valve device, an electric valve, and a refrigeration cycle system, which can suppress thermal stress generated around a welding portion. The valve device includes a valve outer housing (10) that constitutes a valve chamber (S), and a shell member (11) that is welded and fixed to the valve outer housing (10). Airtight containers are constituted by the valve outer housing (10) and the shell member (11) by welding and fixing the shell member (11) to an open end edge of the valve outer housing (10). An annular portion (2B) is provided on the radially inner side of a first welding portion (W1) of the valve outer housing (10) and the shell member (11), and is configured to contact an inner peripheral surface of the valve outer housing (10) that is at least one of the valve outer housing (10) and the shell member (11).

Description

Technical Field

[0001] This invention relates to a valve device, an electric valve, and a refrigeration circulation system. Background Technology

[0002] As a valve device, an electric valve is known to include a valve body, a valve core, a drive unit, and a housing. In this electric valve, the housing is welded to the valve body to form an airtight container (see, for example, Patent Documents 1 and 2). In the electric valve described in Patent Document 1, the housing is directly welded to the upper open end face of the valve body, or the valve core guide member is sandwiched in the middle and welded to it, or the flange portion of the valve shaft support is sandwiched in the middle and welded to it. In the electric valve described in Patent Document 2, the housing is directly welded to the upper open end face of the valve body, and a fixing accessory for a support member is welded to the inner circumference of the valve body.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-211726

[0006] Patent Document 2: Japanese Patent Application Publication No. 2018-150968 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, in conventional electric valves, the shell and the valve body are directly or indirectly welded together. But if the valve body and shell are made thinner for the purpose of weight reduction, there is a possibility of stress corrosion cracking caused by the thermal stress generated at the weld.

[0009] The purpose of this invention is to provide a valve device capable of suppressing thermal stress generated around the welded portion.

[0010] Solution for solving the problem

[0011] To solve the above-mentioned problems and achieve the objective, the valve device of the present invention comprises: a valve housing that constitutes a valve chamber; and a shell component that is welded and fixed to the valve housing. By welding and fixing the shell component to the open end edge of the valve housing, the valve housing and the shell component constitute an airtight container. The valve device is characterized in that an annular component is provided radially inside the welded portion between the valve housing and the shell component, and the annular component is configured to contact the inner circumferential surface of at least one of the valve housing and the shell component.

[0012] According to this invention, since the annular member disposed radially inside the weld portion of the valve housing and the housing component contacts the inner circumferential surface of at least one of the valve housing and the housing component, the heat generated at the weld portion during welding of the valve housing and the housing component can be efficiently transferred to the annular member. This suppresses the formation of a sharp temperature gradient on the valve housing and the housing component due to welding heat remaining at the weld portion. Therefore, a valve device capable of suppressing thermal stress generated around the weld portion can be provided. Furthermore, since this thermal stress can be suppressed, stress corrosion cracking caused by thermal stress can be prevented even when the housing or the like is thin-walled.

[0013] Furthermore, preferably, near the welded portion, when the wall thickness of the shell component is set to 'a', the wall thickness of the valve housing is set to 'b', the axial wall thickness of the annular component is set to 'c', and the axial height of the contact portion between the annular component and the valve housing and the shell component is set to 'd', the relationship is set such that a and b < c and d. According to this structure, near the welded portion, the wall thickness 'c' of the annular component is thicker than the wall thickness 'a' of the shell component and the wall thickness 'b' of the valve housing, and the axial height 'd' of the contact portion between the annular component and the valve housing and the shell component is higher than the wall thickness 'a' of the shell component and the wall thickness 'b' of the valve housing. Therefore, compared to the valve housing side and the shell component side, heat from the welded portion can be more easily transferred to the annular component side. Therefore, compared to cases where the wall thicknesses 'a', 'b', and 'c' and the height 'd' differ from this structure, thermal stress generated around the welded portion of the valve body can be further suppressed.

[0014] Preferably, within a predetermined range near the weld, the cross-sectional area of ​​the annular component is larger than the combined cross-sectional area of ​​the valve housing and the shell component. With this structure, since the cross-sectional area of ​​the annular component is larger than the combined cross-sectional area of ​​the valve housing and the shell component within the predetermined range near the weld, the heat generated around the weld can be transferred to the annular component more efficiently compared to a structure where the cross-sectional area of ​​the annular component is smaller than the combined cross-sectional area. This further suppresses thermal stress generated around the weld.

[0015] Furthermore, preferably, the annular member is pressed into the inner circumference of at least one of the valve housing and the housing component. With this structure, by pressing the annular member into the inner circumference of at least one of the valve housing and the housing component, the annular member can be tightly connected to at least one of the valve housing and the housing component, and the heat generated around the weld can be efficiently transferred to the annular member.

[0016] Furthermore, the electric valve of the present invention is any of the valve devices described above, characterized by comprising: a valve housing; a valve core movably disposed within the valve chamber; a drive unit that drives the valve core; and a housing member covering the drive unit, wherein the annular member is configured to contact the inner peripheral surface of at least one of the valve housing and the housing member. With this structure, an electric valve capable of suppressing thermal stress generated around the welded portion can be provided. Furthermore, since this thermal stress can be suppressed, stress corrosion cracking due to thermal stress can be prevented even when the housing or the like is thin-walled.

[0017] Preferably, the valve housing comprises: a valve body constituting the valve chamber and valve seat; and a cylindrical cover member fixed to the valve body and extending toward the housing member, wherein the housing member is welded to the open end edge of the cover member, and the annular member is configured to contact the inner circumferential surface of at least one of the cover member and the housing member. With this structure, in an electric valve whose valve housing is composed of a valve body and a cover member, thermal stress generated around the welded portion can also be suppressed.

[0018] Furthermore, the refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, an expansion valve, and an evaporator, characterized in that the expansion valve is a valve device or an electric valve as described in any of the above-mentioned embodiments. According to this structure, the refrigeration cycle system can be constructed using a valve device or an electric valve that can suppress thermal stress generated around the welded portion. Attached Figure Description

[0019] Figure 1 This is a longitudinal sectional view of an electric valve according to one embodiment of the present invention.

[0020] Figure 2 This is a partially enlarged cross-sectional view showing the state of the cover and housing components constituting the electric valve before welding.

[0021] Figure 3 This is a partially enlarged cross-sectional view showing the state of the cover and housing components constituting the electric valve after welding.

[0022] Figure 4 This is a partially enlarged sectional view of the welded part in the modified example.

[0023] Figure 5 This is a schematic diagram of a refrigeration cycle system according to one embodiment of the present invention.

[0024] In the picture:

[0025] S—valve chamber; W1—first welded part (welded part); 2B—annular part (annular component); 10—valve housing; 11—housing component; 100—electric valve (valve device). Detailed Implementation

[0026] The following is based on Figures 1-3 An embodiment of the present invention will be described. For example... Figure 1 As shown, the electric valve 100 of this embodiment includes a valve housing 1, a fixing member 2, a valve core 3, a drive unit 4, and a connecting body 5. Furthermore, the concept of "upper and lower" in the following description is different from... Figure 1 The top and bottom correspondences in the attached diagram.

[0027] The valve housing 1 includes: a cylindrical valve outer shell 10 extending along the axis L; and a shell component 11 welded and fixed to the upper open end edge of the valve outer shell 10, forming an airtight container through the valve outer shell 10 and the shell component 11. The valve outer shell 10 includes a bottom cylindrical valve body 10A and a cylindrical cover component 10B connected to the upper end of the valve body 10A. The valve body 10A and the cover component 10B are formed by stamping or machining metal sheets such as SUS (stainless steel) or brass, and their interiors form a valve chamber S.

[0028] A first port 10C, communicating with the inside and outside of the valve chamber S, is formed on the side wall of the valve body 10A. A second port 10D, also communicating with the inside and outside of the valve chamber S, is formed on the bottom wall of the valve body 10A. A first connector pipe 12, communicating with the valve chamber S, is installed at the first port 10C, and a second connector pipe 13, communicating with the valve chamber S, is installed at the second port 10D. Refrigerant flows into or out of the first connector pipe 12 and the second connector pipe 13. The peripheral portion of the second port 10D on the valve chamber S side constitutes the valve seat portion 10E near or away from the valve core 3.

[0029] The cover component 10B is a cylindrical component fixed to the valve body 10A and extending towards the shell component 11, and is riveted and brazed to the upper end of the valve body 10A. For example... Figure 1 As shown, the outer diameter of the upper end of the cover member 10B is set to be smaller than that of the portion other than the upper end. Therefore, as... Figure 2 As shown, the cover member 10B has a guide surface 10B1 and a stepped portion 10B2. The guide surface 10B1 is the portion that guides the shell member 11 when it is fixed to the valve housing 10, and is provided in a manner that it slides in contact with the inner circumferential surface 11A of the lower end of the shell member 11. Therefore, compared with guiding the shell member 11 using other components, it is easier to radially center the shell member 11 relative to the valve housing 10. That is, it is easier to align the axis of the shell member 11 with the axis of the valve housing 10 and the axis L.

[0030] The housing component 11 is a component that covers the drive unit 4. This housing component 11 is formed in a predetermined range (i.e., near the weld) near the first weld portion W1 (described later) by stamping or machining a metal sheet made of SUS (stainless steel) or brass, to a thickness b greater than the wall thickness b of the valve housing 10. Figure 3 (As shown) thin wall thickness a ( Figure 3 As shown), the upper side protrudes into a cylindrical cup shape. Figure 2 As shown, the shell component 11 is configured such that its lower end inner circumferential surface 11A fits into the guide surface 10B1 of the cover component 10B, and its lower end surface 11B abuts against the stepped portion 10B2 of the cover component 10B. Furthermore, in this fitted state, the lower end surface 11B and the stepped portion 10B2 are welded together to fix it to the cover component 10B. That is, the shell component 11 is welded and fixed to the open edge of the cover component 10B. Additionally, the portion where the lower end surface 11B abuts against the stepped portion 10B2 is the first weld portion W1 (weld portion) in this invention.

[0031] The fixing member 2 is disposed within the valve housing 1 and supports the external threaded portion 43B, which will be described later. The fixing member 2 is formed by stamping or machining a metal sheet such as SUS (stainless steel) or brass. It consists of a cylindrical portion 2A coaxially arranged with the valve housing 10 and housing member 11 and extending along the axis L, and an annular portion 2B (annular member) protruding radially outward from the lower end of the cylindrical portion 2A. The cylindrical portion 2A is provided with an internal threaded member 15, which has an internal threaded portion 15A that engages with the external threaded portion 43B, internally formed therein. The internal threaded member 15 is made of resin with PPS (polyphenylene sulfide) as its main component and is formed and fixed to the inner circumference of the cylindrical portion 2A by insert molding. The internal threaded portion 15A is formed at the center of the internal threaded member 15, extending along the axis L.

[0032] The fixing component 2 is disposed within the valve housing 1 such that the annular portion 2B is located radially inside the first welded portion W1. For example... Figure 2 As shown, the outer peripheral surface 2B1 of the annular portion 2B forms a contact portion with the cover member 10B, and is provided in such a way that it contacts the inner peripheral surface of the cover member 10B. That is, the annular portion 2B is provided radially inside the first welded portion W1 between the cover member 10B (valve housing 10) and the housing member 11, and is provided in such a way that it contacts the inner peripheral surface of the valve housing 10, which is at least one of the valve housing 10 and the housing member 11. Figure 2 As shown, a protrusion 2B2 is formed at the upper end of the annular portion 2B, which protrudes radially outward around the entire circumference of the axis L.

[0033] In this embodiment, the annular portion 2B is pressed into the inner circumference of the cover member 10B, and is fixed inside the valve housing 1 by welding the lower end face of the protrusion 2B2 and the upper end face 10B3 of the cover member 10B. That is, the annular portion 2B is pressed into the inner circumference of the valve housing 10, which is at least one of the valve housing 10 and the housing member 11. The protrusion 2B2 abuts against the upper end face 10B3 of the cover member 10B, and the welded portion constitutes the second welded portion W2.

[0034] Furthermore, in this embodiment, the annular portion 2B is pressed in and welded to the valve housing 10, but the method of fixing the annular portion 2B is not limited to this. The fixing method can be simply pressing in, simply welding, or other methods. In addition, the interlocking of the annular portion 2B and the valve housing 10 is not limited to the "interference fit" as in this embodiment, but can also be set as an "intermediate fit" or a "clearance fit". For example, the interlocking can also be set as a type of clearance fit, namely a "close fit", where a small gap can be created between the inner circumferential surface of the cover member 10B and the outer circumferential surface 2B1 of the annular portion 2B, which does not impede the heat conduction of the first welded portion W1 and the second welded portion W2.

[0035] The annular portion 2B is formed such that, within a predetermined range near the first welded portion W1, the wall thickness c in the axial direction L (in...) Figure 3 (As shown in the diagram) The wall thickness b of the valve housing 10 and the wall thickness a of the housing component 11 are thicker than those within the predetermined range. Furthermore, the vertical dimension d of the outer peripheral surface 2B1 (i.e., the height in the L-direction of the contact portion between the annular portion 2B and the valve housing 10) is formed to be greater than the wall thickness a of the housing component 11 and the wall thickness b of the valve housing 10 within a predetermined range near the first weld portion W1. That is, in this embodiment, near the first weld portion W1, when the wall thickness of the housing component 11 is set to a, the wall thickness of the valve housing 10 is set to b, the wall thickness in the axial direction of the annular portion 2B is set to c, and the height in the L-direction of the contact portion between the annular portion 2B and the valve housing 10 is set to d, the relationship is set as a, b < c, d. Preferably, a < c, d, b < c, d, or a + b < c, d.

[0036] Furthermore, from the viewpoint of lightweighting and compactness, the upper limit of the wall thickness c of the annular portion 2B is preferably less than four times the wall thickness b of the valve housing 10. Additionally, the predetermined range near the first weld portion W1 refers to the range where the welding heat of the first weld portion W1 is easily transferred; specifically, in... Figure 3In the sectional view shown (a partially enlarged sectional view near the welded portion of the cover member 10B and the shell member 11 on the left side of the central axis in the longitudinal section of the electric valve 100), the area within a radius R is centered on the first welded portion W1. In the above sectional view, from the viewpoint of heat transfer, it is preferable that the radius R is, for example, 2 to 3 times the wall thickness c of the annular portion 2B. In this case, the cross-sectional area of ​​the annular portion 2B within the radius R is more preferably larger than the sum of the cross-sectional areas of the valve housing 10 and the shell member 11, i.e., the total cross-sectional area. Furthermore, although the description is based on cross-sectional area, in this case, it is also equivalent to comparing the volume by multiplying the perimeters of the annular portion 2B, the valve housing 10, and the shell member 11 by these cross-sectional areas.

[0037] Inside the valve housing 1, a guide member 14 is provided at the boundary between the valve body 10A and the cover member 10B to guide the needle-shaped portion 31 of the valve core 3 along the axis L. A guide hole 14a centered on the axis L is formed in the center of the guide member 14.

[0038] The valve core 3 is configured to move closer to or further away from the valve seat portion 10E as the threaded shaft 43 (described later) moves forward and backward. That is, the valve core 3 is movably disposed within the valve chamber S. The valve core 3 includes a cylindrical needle-shaped portion 31 extending along the axis L and a flange portion 32 located at the upper end of the needle-shaped portion 31. The upper end of the needle-shaped portion 31 has a reduced diameter portion 31A, smaller in diameter than the lower end. The needle-shaped portion 31 is inserted through a guide hole 14a of the guide member 14 with a small gap (void) and is guided forward and backward along the axis L. The flange portion 32 is an anti-detachment member that prevents the needle-shaped portion 31 from detaching from the connector 5 (described later) when connecting it to the valve core 3, and is formed with a diameter larger than the reduced diameter portion 31A.

[0039] The drive unit 4 drives the valve core 3 and includes a stepper motor 4A as an electric motor and a stop mechanism 4B that limits the rotation of the stepper motor 4A. The stepper motor 4A includes: a stator coil 41 disposed on the outer periphery of the housing member 11; a magnetic rotor 42 disposed on the inner periphery of the stator coil 41 through the housing member 11 and rotating circumferentially along the axis L; and a threaded shaft 43 as a drive shaft, which is integrally driven to rotate with the magnetic rotor 42. An upwardly protruding extension shaft 42A is provided at the upper end of the magnetic rotor 42.

[0040] The upper end of the threaded shaft 43 is fixed to the central part of the magnetic rotor 42 via a welded portion 43A. The threaded shaft 43 is made of metal such as SUS. An external thread portion 43B is formed at the central part of the threaded shaft 43 in the direction of the axis L. The external thread portion 43B engages with the internal thread portion 15A and is fed threadedly while sliding along the upper and lower surfaces of its thread teeth in the circumferential direction. That is, if the magnetic rotor 42 rotates, the external thread portion 43B is fed threadedly by rotating the threaded shaft 43, thereby causing the threaded shaft 43 to move forward and backward within the valve body 1.

[0041] Thus, the internal thread portion 15A and the external thread portion 43B constitute a thread feed mechanism. As the threaded shaft 43 rotates due to the drive of the stepper motor 4A, the threaded shaft 43 moves forward and backward in the direction of the axis L. The lower end of the threaded shaft 43 is formed with a diameter larger than the other parts of the threaded shaft 43, constituting an expanded diameter portion 43C. Furthermore, a retaining member 44 that covers the outer periphery of the threaded shaft 43 circumferentially is installed between the external thread portion 43B and the expanded diameter portion 43C of the threaded shaft 43.

[0042] The stop mechanism 4B includes a guide member 45 hanging from the top of the housing member 11, a guide wire 46 spirally wound around the outer periphery of the guide member 45, and a movable slider 47 guided by the guide wire 46 and movable in the vertical direction. The guide member 45 is arranged coaxially with the central axis of the threaded shaft 43 and extends along the axis L. The movable slider 47 is arranged in a manner that it is wound into the groove of the spiral of the guide wire 46. A claw portion 47A is formed on the movable slider 47, protruding radially outward from the guide member 45. The claw portion 47A abuts against the aforementioned extension shaft 42A provided on the magnetic rotor 42 in the circumferential direction along the axis L. According to this structure, as the magnetic rotor 42 rotates, the movable slider 47 is driven to rotate along the groove of the guide wire 46 in the circumferential direction of the guide member 45, thereby making the movable slider 47 movable in the vertical direction.

[0043] An upper stop 46A and a lower stop 46B are formed at the upper and lower ends of the guide wire 46, respectively, to abut against the claw portion 47A of the movable slider 47. The upper stop 46A and the lower stop 46B restrict the rotation of the claw portion 47A that abuts against it. According to this structure, the movable slider 47, which abuts against the upper stop 46A, cannot rotate further. Furthermore, when the rotation of the movable slider 47 is restricted, the rotation of the magnetic rotor 42, which drives the movable slider 47 to rotate, is also restricted. That is, the upper stop 46A functions as a stop that restricts the uppermost position of the magnetic rotor 42. Similarly, when the claw portion 47A abuts against the lower stop 46B, the rotation of the movable slider 47 is restricted, and the rotation of the magnetic rotor 42 is also restricted. That is, the lower stop 46B functions as a stop that limits the lowermost position of the magnetic rotor 42.

[0044] The connector 5 is a component that connects the valve core 3 and the drive unit 4 in the direction of the axis L, and includes: a metal cylindrical component 51 disposed on the side of the threaded shaft 43; a resin spring-bearing component 52 (resin component) disposed on the side of the valve core 3; and a metal compression spring 53 located between the cylindrical component 51 and the spring-bearing component 52. The cylindrical component 51 is made of metal such as SUS and is configured to have a cylindrical sliding portion 51A extending in the direction of the axis L and a threaded shaft-side flange portion 51B protruding radially outward from the upper end of the cylindrical sliding portion 51A. The cylindrical sliding portion 51A is disposed with a predetermined gap in the radial direction from the threaded shaft 43. The threaded shaft-side flange portion 51B is configured to abut against the upper end of the compression spring 53.

[0045] A rolling bearing 54 (ball bearing) is provided at the center of the inner peripheral wall of the cylindrical sliding portion 51A in the direction of axis L. The rolling bearing 54 is a bearing that connects the threaded shaft 43 and the cylindrical component 51 in a rotatable manner, and is configured to have an inner ring 54A, a steel ball 54B, and an outer ring 54C. The inner ring 54A covers the outer periphery of the threaded shaft 43 from the lower end of the aforementioned retaining member 44 to the front of the enlarged diameter portion 43C. The outer ring 54C is fixed to the cylindrical sliding portion 51A by a retaining ring 55 pressed into the upper end of the inner peripheral surface of the cylindrical sliding portion 51A in the direction of axis L. Thus, the threaded shaft 43 and the cylindrical component 51 are connected via the rolling bearing 54. A connecting hole 51A2, coaxial with the central axis and axis L, is formed through the center of the bottom wall of the cylindrical sliding portion 51A. This connecting hole 51A2 is a hole for the insertion of the connecting cylindrical portion 56, which will be described later.

[0046] The spring bearing member 52 is a component that transmits the force of the compression spring 53 along the axis L. It is formed using a resin with PPS (polyphenylene sulfide) as the main component through injection molding, machining, etc. The spring bearing member 52 has a cylindrical guide portion 52A extending along the axis L and a valve core-side flange portion 52B protruding circumferentially outward from the lower end of the cylindrical guide portion 52A. The cylindrical guide portion 52A has an inner diameter larger than the diameter of the cylindrical sliding portion 51A, allowing it to be inserted into the cylindrical sliding portion 51A. With this structure, the inner circumferential surface of the spring bearing member 52 slides against the outer circumferential surface of the cylindrical sliding portion 51A along the axis L. The valve core-side flange portion 52B is configured to abut against the lower end of the compression spring 53.

[0047] A through hole 52A1, coaxial with axis L, is formed in the center of the bottom wall of the cylindrical guide portion 52A. A connecting cylindrical portion 56 is inserted into the through hole 52A1. The connecting cylindrical portion 56 connects the cylindrical component 51 to the spring bearing component 52 and the spring bearing component 52 to the valve core 3, and extends along the axis L both inside and outside the cylindrical guide portion 52A. A groove 56A, recessed radially inward, is formed on the outer side of the cylindrical guide portion 52A in the lower end of the side wall of the connecting cylindrical portion 56. A C-shaped retaining ring 57 is radially inserted into the groove 56A.

[0048] A retaining ring 57 is formed on the lower end face of the bottom wall of the cylindrical guide portion 52A and is inserted into the drive portion 4 relative to the recess 52A2 that opens toward the second port 10D. When the retaining ring 57 is inserted into the recess 52A2, the connecting cylindrical portion 56 is connected to the spring-supporting member 52 by the reaction force of the compression spring 53 pressed toward the drive portion 4 via the spring-supporting member 52. An upper flange 56B is formed at the upper end of the connecting cylindrical portion 56, which engages with the edge of the connecting hole 51A2, thereby connecting the spring-supporting member 52 to the cylindrical member 51. Additionally, although not shown, a portion of the side wall of the connecting cylindrical portion 56 is cut from the upper end to the lower end, forming an opening communicating with the interior of the connecting cylindrical portion 56 through this cut.

[0049] The inner diameter of the connecting cylinder portion 56 is set to be larger than the diameter of the reduced diameter portion 31A of the needle-shaped portion 31, and smaller than the diameter of the flange portion 32. Furthermore, the dimension of the connecting cylinder portion 56 in the L-axis direction is approximately the same as the dimension of the reduced diameter portion 31A in the L-axis direction. Additionally, the dimension of the width of the sidewall of the connecting cylinder portion 56 intersecting the L-axis direction of the opening is approximately the same as the diameter of the reduced diameter portion 31A. The reduced diameter portion 31A is radially inserted into the connecting cylinder portion 56 via the opening. With this structure, the reduced diameter portion 31A is inserted into the connecting cylinder portion 56 with a radial gap, and the flange portion 32 acts as an anti-dislodgement member, preventing the valve core 3 from falling downwards into the connecting cylinder portion 56. Therefore, the valve core 3 is connected to the spring-supporting member 52.

[0050] The compression spring 53 applies force to the valve core 3 along the axis L relative to the threaded shaft 43. The compression spring 53 is made of metal and is located between the cylindrical component 51 and the spring bearing component 52 along the axis L. The upper end of the compression spring 53 abuts against the flange portion 51B on the threaded shaft side, and the lower end of the compression spring 53 abuts against the flange portion 52B on the valve core side.

[0051] As the above-mentioned electric valve 100 operates, firstly, Figure 1In the open valve state shown, the flange portion 32 acts as an anti-detachment component, and the valve core 3 is suspended from the threaded shaft 43 via the connecting body 5. If the stepper motor 4A of the drive unit 4 is rotated from this open valve state, causing the threaded shaft 43 to descend in the valve-closing direction, the front end of the needle-shaped portion 31 approaches the valve seat portion 10E. Furthermore, if the threaded shaft 43 is further descended from this state, the compression spring 53 is compressed in the axis L direction, thereby exerting a downward force. By applying this force, the front end of the needle-shaped portion 31 is pressed against the valve seat portion 10E, thus achieving the valve-closing state. In this valve-closing state, the needle-shaped portion 31 and the valve seat portion 10E are pressed along the axis L direction by the force of the compression spring 53, thereby preventing the needle-shaped portion 31 from floating and maintaining the valve-closing state, even when high refrigerant pressure acts on the needle-shaped portion 31 from the second connector pipe 13 side. The states from valve opening to valve closing in this embodiment have been described in sequence above. However, it is self-evident that the same operation is performed in the reverse order when the valve is closed to open. In addition, although the front end of the needle-shaped portion 31 is pressed against the valve seat portion 10E in this embodiment, it is not necessary to close the valve. The present invention can be applied to flow control valves where the needle-shaped portion 31 is only close to or far away from the valve seat portion 10E.

[0052] When assembling the electric valve 100, such as Figure 2 As shown, the lower end of the shell component 11 is fitted into the upper end of the valve housing 10. Specifically, while the inner circumferential surface 11A of the lower end of the shell component 11 is in sliding contact with the guide surface 10B1 of the cover component 10B, the shell component 11 is inserted into the cover component 10B, and the lower end surface 11B of the shell component 11 abuts against the stepped portion 10B2 of the cover component 10B. Furthermore, in this fitted state, as... Figure 3 As shown, the lower end face 11B and the stepped portion 10B2 are welded. At this time, as... Figure 3 As indicated by the arrow, the heat generated at the first weld W1 is transferred to the valve housing 10 side, the housing component 11 side, and the annular portion 2B side. Furthermore, as described above, the valve housing 10, housing component 11, and annular portion 2B are made of metals such as SUS, and the heat generated at the first weld W1 is within a predetermined range (as described above). Figure 3The cross-sectional area (or the volume obtained by multiplying the cross-sectional area by the perimeter) of the shown cross-sectional view is larger than the cross-sectional area of ​​the annular portion 2B (or the volume obtained by multiplying the cross-sectional area of ​​the annular portion 2B by the perimeter of the annular portion 2B) than the combined cross-sectional area of ​​the valve housing 10 and the housing component 11 (or the combined volume obtained by multiplying the cross-sectional area of ​​the valve housing 10 by the perimeter of the valve housing 10 and the volume obtained by multiplying the cross-sectional area of ​​the housing component 11 by the perimeter of the housing component 11). The vertical dimension d of the outer peripheral surface 2B1 (i.e., the height in the axial direction L of the contact portion between the annular portion 2B and the valve housing 10) is greater than the wall thickness a of the housing component 11 and the wall thickness b of the valve housing 10 within a predetermined range near the first weld portion W1. Therefore, the aforementioned heat can be transferred to the annular portion 2B side most efficiently. Thus, the heat generated at the first weld portion W1 is efficiently transferred to the annular portion 2B.

[0053] According to the above-described embodiment, since the annular portion 2B on the radially inner side of the first weld portion W1 (weld portion) provided between the valve housing 10 and the housing component 11 is in contact with the inner circumferential surface of the valve housing 10, which is at least one of the valve housing 10 and the housing component 11, the heat generated at the first weld portion W1 during welding of the valve housing 10 and the housing component 11 can be efficiently transferred to the annular portion 2B. Therefore, the situation where a sharp temperature gradient occurs between the valve housing 10 and the housing component 11 due to welding heat remaining at the first weld portion W1 can be suppressed. Thus, a valve device that can suppress thermal stress generated around the weld portion can be provided. Furthermore, since this thermal stress can be suppressed, stress corrosion cracking caused by thermal stress can be prevented even when the housing component 11 or the like is thin-walled.

[0054] Furthermore, near the first welded portion W1, the wall thickness c of the annular portion 2B is thicker than the wall thickness a of the shell component 11 and the wall thickness b of the valve housing 10. The height d along the axial L direction of the contact portion between the annular portion 2B and the valve housing 10 and the shell component 11 is higher than the wall thickness a of the shell component 11 and the wall thickness b of the valve housing 10. Therefore, compared to the valve housing 10 side and the shell component 11 side, heat from the first welded portion W1 can be more easily transferred to the annular portion 2B side. Thus, compared to cases where the wall thicknesses a, b, c, and height d differ from this structure, thermal stress generated around the first welded portion W1 of the valve body 10A can be further suppressed.

[0055] Furthermore, within a predetermined range near the first welded portion W1, the cross-sectional area of ​​the annular portion 2B can be larger than the combined cross-sectional area of ​​the valve housing 10 and the housing component 11. Therefore, compared to a structure where the cross-sectional area of ​​the annular portion 2B is smaller than the combined cross-sectional area, the heat generated around the first welded portion W1 can be transferred to the annular portion 2B more efficiently. As a result, the thermal stress generated around the welded portion can be further suppressed.

[0056] In addition, the annular portion 2B can be pressed into the inner circumference of at least one of the valve housing 10 and the housing component 11, so that the annular portion 2B can be tightly connected to at least one of the valve housing 10 and the housing component 11, and the heat generated around the first weld portion W1 can be efficiently transferred to the annular portion 2B.

[0057] Next, based on Figure 4 Modifications of the present invention will be described. Figure 4 This is a partially enlarged sectional view of the first welded part W1 in the modified example. Figure 4 The electric valve 100 of (A) differs from the electric valve 100 of this embodiment in that: no protrusion 2B2 is formed in the annular portion 2B, and the upper part of the outer peripheral surface 2B1 is welded to the inner peripheral surface of the cover member 10B to form a second welded portion W2.

[0058] Figure 4 (B) electric valve 100 and Figure 4 Similarly, unlike the electric valve 100 of this embodiment, (A) does not have a protrusion 2B2. Furthermore, unlike the electric valve 100 of this embodiment, instead of making the outer diameter of the upper end of the cover member 10B smaller than the outer diameter of the other parts of the cover member 10B, the outer diameter of the lower end of the shell member 11 is smaller than the outer diameter of the other parts of the shell member 11. That is, a structure corresponding to the guide surface 10B1 and the step portion 10B2 of this embodiment is provided on the shell member 11 side, namely the guide surface 11B1 and the step portion 11B2, and the shell member 11 guides the valve shell 10. Then, the step portion 11B2 and the upper end surface 10B3 of the cover member 10B are welded to form a first welded portion W1. Furthermore, the inner peripheral surface of the shell member 11 is welded to the outer peripheral surface 2B1 of the annular portion 2B to form a second welded portion W2. Thus, the annular portion 2B is disposed radially inside the first welded portion W1 between the cover member 10B (valve housing 10) and the housing member 11, and is disposed such that it abuts against the inner circumferential surface of the housing member 11, which is at least one of the valve housing 10 and the housing member 11. In this case, the vertical dimension d of the outer circumferential surface 2B1 of the annular portion 2B (i.e., the height in the axial direction L of the contact portion between the annular portion 2B and the housing member 11) is also larger than the aforementioned wall thicknesses a and b.

[0059] exist Figure 4In the electric valve 100 of (C), the guide surface 10B1 and the stepped portion 10B2 are not provided. The upper end surface 10B3 of the cover member 10B and the lower end surface 11B of the shell member 11 are welded to form a first welded portion W1. The annular portion 2B is welded to the shell member 11 in such a way that it contacts the cover member 10B and extends to the shell member 11, forming a second welded portion W2. That is, in the above-described embodiments and modifications, the heat of the first welded portion W1 is indirectly transferred to the annular portion 2B via the valve shell 10 or the shell member 11. However, in this modification, the heat is directly or indirectly transferred from the first welded portion W1 to the annular portion 2B, corresponding to the depth of the first welded portion W1 (the length of the welded portion in the thickness direction of the cover member 10B and the shell member 11). In addition, in Figure 4 In (C), the second welding part W2 is provided on the upper side of the outer peripheral surface 2B1 of the annular part 2B, but the second welding part W2 may also be provided on the lower side of the outer peripheral surface 2B1.

[0060] Furthermore, as described above, in one embodiment and three variations, the annular portion 2B (annular component) is disposed radially inside the first welded portion W1 between the cover component 10B (valve housing 10) and the shell component 11. However, specifically, in one embodiment and the first variation ( Figure 4 In (A) shown, the annular portion 2B is disposed radially inside the first welded portion W1, and the first welded portion W1 is disposed within the axial direction height d of the outer peripheral surface 2B1 of the annular portion 2B, which is the contact portion between the annular portion 2B and the cover member 10B. In the second modified example ( Figure 4 In (B) shown, the annular portion 2B is disposed radially inside the first welded portion W1, and the first welded portion W1 is disposed within the axial direction height d of the outer peripheral surface 2B1 of the annular portion 2B, which is the contact portion between the annular portion 2B and the shell component 11. In the third variation ( Figure 4 In (C) shown, the annular portion 2B is disposed radially inside the first weld portion W1, and the first weld portion W1 is disposed within the axial direction height d of the contact portion between the cover member 10B and the shell member 11 and the annular portion 2B, i.e., the outer peripheral surface 2B1 of the annular portion 2B. With this structure, when welding the cover member 10B and the shell member 11, compared to a structure where the first weld portion W1 is not disposed within the aforementioned axial direction height d, the first weld portion W1 is closer to the annular portion 2B, thus enabling more efficient transfer of welding heat to the annular portion 2B.

[0061] Next, based on Figure 5 The refrigeration cycle system of the present invention will be described. Figure 5 This is a diagram illustrating the refrigeration cycle system of the implementation method. Figure 5In the diagram, reference numeral 1000 indicates the expansion valve using the electric valve 100 described above; reference numeral 2000 indicates the outdoor heat exchanger mounted on the outdoor unit; reference numeral 3000 indicates the indoor heat exchanger mounted on the indoor unit; reference numeral 4000 indicates the flow path switching valve constituting a four-way valve; and reference numeral 5000 indicates the compressor. The expansion valve 1000, outdoor heat exchanger 2000, indoor heat exchanger 3000, flow path switching valve 4000, and compressor 5000 are connected via conduits as shown, forming a heat pump-type refrigeration cycle. Furthermore, illustrations of accumulators, pressure sensors, temperature sensors, etc., are omitted.

[0062] The flow path of the refrigeration cycle is switched between two modes via a flow path switching valve 4000: one for cooling operation and one for heating operation. During cooling operation, if... Figure 5 As indicated by the arrow in the solid line, the refrigerant compressed by the compressor 5000 flows into the outdoor heat exchanger 2000 through the flow path switching valve 4000. The outdoor heat exchanger 2000 functions as a condenser. The liquid refrigerant flowing out of the outdoor heat exchanger 2000 flows to the indoor heat exchanger 3000 through the expansion valve 1000. The indoor heat exchanger 3000 functions as an evaporator.

[0063] On the other hand, during heating operation, such as Figure 5 As indicated by the dashed arrow, the refrigerant compressed by compressor 5000 circulates from flow path switching valve 4000 through the indoor heat exchanger 3000, expansion valve 1000, outdoor heat exchanger 2000, flow path switching valve 4000, and compressor 5000 in that order. Indoor heat exchanger 3000 functions as a condenser, and outdoor heat exchanger 2000 functions as an evaporator. Expansion valve 1000 depressurizes and expands the liquid refrigerant flowing in from the outdoor heat exchanger 2000 during cooling operation, or from the indoor heat exchanger 3000 during heating operation, thereby controlling the refrigerant flow rate.

[0064] With this structure, even when the shell component 11 and the like are thin-walled, a refrigeration circulation system can be constructed using an electric valve 100 that can prevent stress corrosion cracking caused by thermal stress.

[0065] Furthermore, the present invention is not limited to the above-described embodiments, and includes other structures that can achieve the purpose of the present invention. The variations shown below are also included in the present invention. For example, in this embodiment, the valve housing 10 is constituted by the valve body 10A and the cover component 10B, but it is not necessary to set the valve body 10A and the cover component 10B separately. They can be set as one piece, or the cover component 10B can be omitted.

[0066] In this embodiment, the drive unit 4 is configured as a threaded feed mechanism consisting of an internal threaded portion 15A of an internal threaded component 15 built into the fixed component 2 and an external threaded portion 43B formed on the threaded shaft 43. When the magnetic rotor 42 rotates, the external threaded portion 43B is threadedly fed, thereby causing the threaded shaft 43 and the valve core 3 to move back and forth within the valve housing 1. However, the threaded shaft 43 with the external threaded portion 43B can also be fixed so that it can rotate around the axis L but cannot move in the vertical direction. Instead of having the internal threaded component 15 built into the fixed component 2, it can be configured to move in the vertical direction and connected to the valve core 3. In this structure, when the magnetic rotor 42 rotates, the internal threaded portion 15A is threadedly fed, thereby causing the valve core 3 to move back and forth within the valve housing 1. In addition, the valve device of the present invention can be applied to various valve devices such as solenoid valves and temperature-controlled expansion valves, in addition to the electric valve 100 of the above embodiment and its variations.

[0067] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific structure is not limited to these embodiments, and design changes that do not depart from the spirit of the present invention are also included in the present invention.

Claims

1. A valve device comprising: Valve housing, which constitutes the valve chamber; and The housing component is welded and fixed to the valve housing. By welding and fixing the shell component to the open edge of the valve housing, the valve housing and the shell component together form an airtight container. The valve device is characterized in that... A metal annular component is provided radially inside the welded portion between the valve housing and the shell component. The annular component is configured to contact the inner circumferential surface of at least one of the valve housing and the shell component. The welded portion is located within the axial height range of the contact portion between the annular component and the valve housing and / or the housing component, i.e., the outer peripheral surface of the annular component.

2. The valve device according to claim 1, characterized in that, Near the welded portion, with the wall thickness of the shell component set to a, the wall thickness of the valve housing set to b, the wall thickness of the annular component in the axial direction set to c, and the axial height of the contact portion between the annular component and the valve housing and the shell component set to d, the relationship is set as a, b < c, d.

3. The valve device according to claim 2, characterized in that, Within a predetermined range near the welded portion, the cross-sectional area of ​​the annular component is larger than the combined cross-sectional area of ​​the valve housing and the housing component.

4. The valve device according to any one of claims 1 to 3, characterized in that, The annular component is pressed into the inner periphery of at least one of the valve housing and the housing component.

5. An electric valve, which is an electric valve device as described in any one of claims 1 to 4, characterized in that, have: The valve housing; A valve core, which is movably disposed within the valve chamber; A drive unit that drives the valve core; and The housing component covers the drive unit. The annular component is configured to contact the inner circumferential surface of at least one of the valve housing and the housing component.

6. The electric valve according to claim 5, characterized in that, The valve housing has: The valve body, which constitutes the valve chamber and valve seat; and A cylindrical cover component, which is fixed to the valve body and extends towards the shell component. The shell component is welded and fixed to the open end edge of the cover component. The annular component is configured to contact the inner circumferential surface of at least one of the cover component and the shell component.

7. A refrigeration cycle system comprising a compressor, an expansion valve, and an evaporator, characterized in that, The expansion valve may be the valve device according to any one of claims 1 to 4, or the electric valve according to claim 5 or 6.

Images