Electrically driven valve

Abstract

It is possible to inhibit the bonding strength of the bonding portion between the valve main body and the can from being lowered.SOLUTION: The electrically driven valve (electrically driven valve 10) includes a cylindrical can 40, a valve body 20 including a valve chest 21 through which a fluid flows, a receiving portion 41 provided on the can 40 side in the valve body 20 and having a ring-shaped bottom portion 41A and a receiving sidewall 41B disposed on an outer edge of an end portion of the can sidewall 40B of the can 40 and covering an outer periphery of the end portion of the can sidewall 40B, a welded portion 42 joining the receiving sidewall 41B and the can sidewall 40B, a valve stem 24 disposed inside the can 40, a drive mechanism (a rotor 30, a stator 50, a fixing screw portion 25, a guide bush 26, a moving screw portion 31, a valve shaft holder 32) for raising and lowering the valve stem 24, and a valve body 2 3 connected to the valve shaft 24 and moving in a direction approaching and separating from a valve seat 2 2 of the valve chest 21 in conjunction with raising and lowering of the valve shaft 24.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electrically actuated valves. [Background technology]

[0002] Patent Document 1 discloses an electric valve as an example of an electrically driven valve. This electric valve comprises a valve body having a valve chamber through which a fluid flows, a cylindrical can, a valve stem arranged inside the can, a screw feed mechanism as a drive mechanism for raising and lowering the valve stem, and a valve disc connected to the valve stem that moves toward and away from a valve seat in the valve chamber in conjunction with the raising and lowering of the valve stem.

[0003] In the motor-operated valve of Patent Document 1, the valve body has a ring-shaped flange plate as a receiving portion for the side wall of the can. The outer edge of the can-side surface of the receiving portion abuts against the end face of the side wall of the can. The valve body and the can are joined together by welding the abutting portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-163376 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, for example, when the motor-operated valve is used, the pressure of the fluid flowing through the valve chamber causes the can to expand, generating stress at the joint between the valve body and the can, causing the can to separate from the valve body. Patent Document 1 leaves room for improvement in terms of preventing a decrease in the joint strength of the joint due to the generated stress. Furthermore, even when the motor-operated valve is not in use as an electrically driven valve, it is necessary to prevent a decrease in the joint strength of the joint from decreasing.

[0006] In view of the above, the present disclosure provides an electrically driven valve that can suppress a decrease in the joint strength of the joint between the valve body and the can. [Means for solving the problem]

[0007] The electrically driven valve according to the first aspect comprises: a valve body having a cylindrical can and a valve chamber through which a fluid flows; a receiving portion provided on the can side of the valve body and having a ring-shaped bottom and a receiving side wall disposed on the outer edge of the bottom and covering the outer periphery of the end of the can side wall of the can; a welded portion joining the receiving side wall and the can side wall; a valve stem disposed inside the can; a drive mechanism for raising and lowering the valve stem; and a valve element connected to the valve stem and moving toward and away from a valve seat in the valve chamber in conjunction with the raising and lowering of the valve stem.

[0008] In the electrically driven valve according to the first aspect, the welded joint joins the receiving side wall of the receiving portion of the valve body to the can side wall of the can, which can prevent a decrease in the joining strength of the joint compared to, for example, when the receiving portion does not have a side wall and is composed only of a ring-shaped bottom portion and the end face of the can side wall is butt-welded to the surface of the bottom portion.

[0009] In a second aspect, in the electrically driven valve according to the first aspect, the welded portion is located at an upper end of the receiving side wall.

[0010] In the second aspect, the base portion of the receiving side wall at the bottom of the receiving part is separated from the welded part at the upper end, so that the deterioration of the material at the base portion caused by the heat effect of welding can be suppressed, thereby improving the yield strength of the receiving part.

[0011] In a third aspect, in the electrically driven valve according to the first or second aspect, the valve body and the receiving portion are integrally formed by a single member.

[0012] In the third aspect, the number of components can be reduced compared to when the valve body and the receiving portion are formed separately from different components.

[0013] In a fourth aspect, in the electrically driven valve according to the first or second aspect, the valve body and the receiving portion are formed separately from each other using different members.

[0014] In the fourth aspect, the degree of freedom in design can be improved compared to when the valve body and the receiving portion are integrally formed from a single member.

[0015] In a fifth aspect, in the electrically driven valve according to any one of the first to fourth aspects, the drive mechanism includes a rotor that rotates integrally with the valve body, a stator that rotates the rotor, and a feed screw mechanism that raises and lowers the valve body.

[0016] In the fifth aspect, an electrically driven valve can be realized that includes a drive mechanism having a rotor, a stator, and a feed screw mechanism. [Effects of the Invention]

[0017] According to the present disclosure, an electrically driven valve can be provided that can suppress a decrease in the joint strength of the joint between the valve body and the can. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view illustrating an embodiment of the motor-operated valve according to the present disclosure, taken along a plane including a central axis that is a rotation axis. [Figure 2] 1 is an enlarged cross-sectional view illustrating a joint between a valve body and a can of an electric valve according to an embodiment of the present invention, in a state in which stress caused by expansion of the can is not generated at the joint. FIG. [Figure 3] 1 is an enlarged cross-sectional view illustrating a joint between a valve body and a can of an electric valve according to an embodiment of the present invention, showing a state in which stress is generated at the joint when the can expands. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] 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. may differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, there may be parts with different dimensional relationships and ratios 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.

[0020] <Motor-operated valve configuration> The motor-operated valve 10 according to this embodiment is an example of an electrically driven valve and includes a valve body 20, a can 40 incorporating a rotor 30 fixed to the valve body 20, and a stator 50 fitted to the outside of the can 40. The rotor 30 and the stator 50 form a stepping motor.

[0021] The motor-operated valve 10 also includes a welded portion 42, a valve stem 24, a drive mechanism, and a valve element 23. The rotor 30 moves the valve element 23 toward and away from a valve seat 22 in a valve chamber 21. The valve body 20 adjusts the flow rate of a refrigerant fluid passing through it by using the moving valve element 23. Note that in the present disclosure, the electrically driven valve is not limited to a motor-operated valve, and may be another electrically driven valve such as a solenoid valve.

[0022] (Can) The can 40 is a cylindrical member with a bottom made of a non-magnetic metal such as stainless steel, and has a can bottom 40A and a can sidewall 40B extending downward in FIG.

[0023] (Valve body) The valve element 23, which is a needle valve, is formed at the lower end of a valve stem 24 made of, for example, brass. The valve stem 24 is disposed inside the can 40. The valve element 23 is connected to the valve stem 24 by a drive mechanism, and moves toward and away from the valve seat 22 of the valve chamber 21 in conjunction with the elevation of the valve stem 24.

[0024] (Drive mechanism) The drive mechanism of this embodiment moves the valve element 23 relative to the valve seat 22 by raising and lowering the valve stem 24. The drive mechanism of this embodiment has a rotor 30 that rotates integrally with the valve element 23, a stator 50 that rotates the rotor 30, and a feed screw mechanism that raises and lowers the valve element 23.

[0025] The stator 50 is composed of a yoke made of a magnetic material and a stator coil wound around the yoke via a bobbin (illustration of the yoke, bobbin, and stator coil is omitted).

[0026] A plurality of lead terminals connected to the stator coil protrude from the stator 50. Connectors to which a plurality of lead wires are connected are connected to these lead terminals. A cover that covers the connector is welded to the stator 50, and the inside of the cover is filled with a filler material such as silicone resin. The lead terminals, lead wires, connector filler material, and filler material are not shown in the drawings.

[0027] A fitting hole that opens downward in Fig. 1 is formed in the center of the stator 50. The can 40 fits into the fitting hole of the stator 50. The stator 50 is fixed to the valve body 20 and the can 40 by a rotation-preventing member welded to the underside of the stator 50 in Fig. 1.

[0028] The feed screw mechanism is composed of a cylindrical guide bush 26 and a valve stem holder 32 having a moving screw portion 31 that is screw-coupled to the fixed screw portion 25 of the guide bush 26. The feed screw mechanism is disposed approximately in the center of the entire axial length within the rotor 30. The guide bush 26 is fixed to the upper part of the valve body 20 in FIG. 1. The guide bush 26 extends from the valve body 20 toward the rotor 30. The fixed screw portion 25 is formed in the center of the guide bush 26 in the up-down direction in FIG. 1. In the present disclosure, the drive mechanism that moves the valve element is not limited to a feed screw mechanism, and a mechanism that moves the valve element by electromagnetic action, for example, may be used.

[0029] The fixed screw portion 25 is formed as a male screw on the outer periphery of the guide bush 26. The moving screw portion 31 is formed as a female screw on the inner periphery of the valve stem holder 32. Note that, although the guide bush 26 and the valve stem holder 32 in this embodiment are both cylindrical members made of brass, for example, the material of the outer surfaces of the guide bush 26 and the valve stem holder 32 in the present disclosure is not limited to this.

[0030] The stem holder 32 is located radially outside the guide bush 26 and opens to the bottom in FIG. 1. A moving thread portion 31 is formed on the inner surface of the stem holder 32. The stem 24 is located at the radial center of the motor-operated valve 10. The reduced-diameter portion at the top of the stem 24 is fitted into the stem holder 32. The stem 24 and the stem holder 32 are connected by a push nut 33. The stem 24 is made of brass, for example. The valve element 23 is formed at the lower end of the stem 24 in FIG. 1. The stem 24 is inserted into the center of the stem holder 32, fitted so as to be able to move up and down. The stem 24 is constantly biased downward by a compression coil spring 34, which is mounted in a compressed state inside the stem holder 32. A pressure equalizing hole 32A is formed on the side of the stem holder 32 to equalize the pressure in the valve chamber 21 and the can 40.

[0031] The push nut 33 is fixed by being press-fitted onto the upper end of the valve stem 24 in Figure 1. A return spring 35 is attached near the outer circumferential surface of the push nut 33. The return spring 35 is composed of a cylindrical compression coil spring. When the fixed screw portion 25 of the guide bush 26 and the moving screw portion 31 of the valve stem holder 32 are disengaged from each other, the return spring 35 comes into contact with the inner surface of the can 40 and urges the guide bush 26 to return the screw connection between the fixed screw portion 25 and the moving screw portion 31 to its original state. The return spring 35 may be attached in a state in which it is placed while being loosely fitted near the outer circumferential surface of the push nut 33, or it may be attached elastically to the outer circumferential surface of the push nut 33.

[0032] (Valve body) The valve body 20 is a cylindrical member with a bottom. The valve body 20 is made of a metal such as brass. The valve body 20 has a valve chamber 21 inside, through which a fluid flows. The valve chamber 21 opens to the upper side in FIG. 1. The fluid is, for example, a high-pressure refrigerant.

[0033] A fluid outlet pipe 20A and a fluid inlet pipe 20B are attached to the valve body 20. In FIG. 1, the axial direction of the fluid outlet pipe 20A attached to the lower side of the valve body 20 overlaps with the central axis V of the motor-operated valve 10. In FIG. 1, the axial direction of the fluid inlet pipe 20B attached to the left side of the valve body 20 is parallel to a horizontal line H that perpendicularly intersects with the central axis V. The interiors of the fluid outlet pipe 20A and the fluid inlet pipe 20B both communicate with the valve chamber 21.

[0034] In this embodiment, the stem holder 32 and the rotor 30 are joined via a support ring 36. The support ring 36 in this embodiment is made of a brass metal ring that is inserted when the rotor 30 is molded. An upper protrusion of the stem holder 32 fits into the inner circumferential hole of the support ring 36, and the outer periphery of the upper protrusion is crimped and fixed, thereby joining the rotor 30, support ring 36, and stem holder 32 together.

[0035] A lower stopper body 27 serving as a fixed stopper is fixed to the guide bush 26. The lower stopper body 27 constitutes one side of the stopper mechanism. The lower stopper body 27 is made of a ring-shaped plastic. A plate-shaped lower stopper piece 27A is provided at the top of the lower stopper body 27 in FIG. 1, protruding upward. An upper stopper body 37 serving as a moving stopper is fixed to the valve stem holder 32. The upper stopper body 37 constitutes the other side of the stopper mechanism. Like the lower stopper body 27, the upper stopper body 37 is also made of a ring-shaped plastic. A plate-shaped upper stopper piece 37A is provided at the bottom of the upper stopper body 37 in FIG. 1, protruding downward. The upper stopper piece 37A and the lower stopper piece 27A butt against each other.

[0036] The lower stopper body 27 is fixed to the spiral groove portion 26A formed on the outer periphery of the guide bush 26 by being integrally formed by injection molding. The upper stopper body 37 is fixed to the spiral groove 32B formed on the outer periphery of the valve stem holder 32 by being integrally formed by injection molding. Note that the fixing of the lower stopper body 27 and the upper stopper body 37 is not limited to injection molding, and may also be achieved by adhesive bonding, press fitting, or the like.

[0037] (receiving part) Next, the receiving portion 41 and the welded portion 42 of this embodiment will be described in detail. As shown in Fig. 2, the receiving portion 41 is attached to the can 40 side of the valve body 20 (the upper side of the valve body 20 in Fig. 2). The receiving portion 41 is made of metal such as stainless steel.

[0038] As shown in FIG. 1 , the valve body 20 is inserted into the ring-shaped bottom portion 41A. The valve body 20 and the bottom portion 41A of the receiving portion 41 are integrated by welding or the like. The receiving portion 41 has a ring-shaped bottom portion 41A and a receiving side wall 41B disposed on the outer edge of the bottom portion 41A. The receiving side wall 41B extends from the outer edge of the bottom portion 41A toward the can side wall 40B of the can 40. The receiving side wall 41B extends along the vertical direction of the outer peripheral surface of the can side wall 40B in FIG. 1, i.e., along the axial direction of the valve stem 24. The receiving side wall 41B covers the outer periphery of the lower end of the can side wall 40B in FIG. 1. In this embodiment, the valve body 20 and the receiving portion 41 are formed separately from different members. However, in the present disclosure, the valve body 20 and the receiving portion 41 may be integrally formed from a single member.

[0039] (weld) As shown in FIG. 2, the weld 42 joins the upper end of the receiving side wall 41B to the outer surface of the portion above the lower end of the can side wall 40B. The weld 42 is the joint between the valve body 20 and the can 40. In the present disclosure, the height of the weld 42 is not limited to the upper end of the receiving side wall 41B, and it may be in the middle between the upper and lower ends in FIG. 2. By joining the can 40 to the receiving portion 41 by the weld 42, an airtight state is maintained inside the can 40. In this embodiment, the lower end of the can side wall 40B in FIG. 2 abuts and contacts the upper surface of the bottom 41A. In the present disclosure, it is not essential that the lower end of the can side wall 40B contact the upper surface of the bottom 41A.

[0040] As shown in Figure 3, when the motor-operated valve 10 is used, the can 40 expands due to the pressure of the fluid flowing through the valve chamber 21, causing stress to be generated in the welded portion 42, which is the joint between the valve body 20 and the can 40. Specifically, a force acting on the welded portion 42 is directed outward (upward in Figure 3) along the axial direction of the central axis V of the motor-operated valve 10, and a force acting outward (toward the left in the case of the welded portion 42 in Figure 3) along a radial direction perpendicular to the axial direction. Even when stress is applied, in this embodiment, the welded portion 42 prevents the can 40 from separating from the valve body 20.

[0041] (Action and effect) In this embodiment, the welded portion 42, which is the joint, joins the receiving side wall 41B of the receiving portion 41 of the valve body 20 and the can side wall 40B of the can 40. Therefore, a decrease in the joint strength of the joint can be suppressed compared to, for example, when the receiving portion 41 does not have a side wall and is composed only of the ring-shaped bottom portion 41A, and the end face of the can side wall 40B is butt-welded to the surface of the bottom portion 41A. The suppression of a decrease in the joint strength of the joint can be achieved both when the motor-operated valve 10 is in use and when the motor-operated valve 10 is not in use.

[0042] Furthermore, in this embodiment, a decrease in the bond strength of the joint can be suppressed simply by changing the shape of the receiving portion 41, eliminating the need for complex design changes to the can 40. If the design of the can 40 is changed, for example, by increasing the thickness of the can side wall 40B in order to increase the bond strength, there is a concern that torque output will decrease in an electrically operated valve 10 in which the rotor 30 and the stator 50 are arranged with the can side wall 40B sandwiched therebetween. For this reason, this embodiment, which can suppress a decrease in the bond strength of the joint simply by changing the shape of the receiving portion 41, is advantageous in that it makes it easy to avoid complex design changes to the can 40.

[0043] In addition, in this embodiment, the base portion of the receiving side wall 41B at the bottom 41A of the receiving portion 41 is separated from the upper end welded portion 42, so that the deterioration of the material at the base portion caused by the heat of welding can be suppressed. As a result, the bearing strength of the receiving portion 41 is improved.

[0044] In addition, in this embodiment, the valve body 20 and the receiving portion 41 are formed separately from different members, which improves the degree of freedom in design compared to when the valve body 20 and the receiving portion 41 are integrally formed from a single member. Note that in the present disclosure, the number of members can be reduced by forming the valve body 20 and the receiving portion 41 separately from different members.

[0045] Furthermore, in this embodiment, it is possible to realize the motor-operated valve 10 that includes a drive mechanism having the rotor 30, the stator 50, and a feed screw mechanism.

[0046] Although the present disclosure has been described based on the above disclosed embodiments, the descriptions and drawings that form part of this disclosure should not be understood to limit the present disclosure. For example, the present disclosure can be configured by partially combining the configurations illustrated in the attached drawings. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specific matters in the scope of the claims that are appropriate from the above description. [Explanation of symbols]

[0047] 10 Electric valve (electrically driven valve) 20 Valve body 20A fluid outflow pipe 20B Fluid inlet pipe 21 Valve chamber 22 Valve seat 23 Valve body 24 Valve stem 25 Fixed screw section (feed screw mechanism) 26 Guide bush (feed screw mechanism) 26A Spiral groove part 27 Lower stopper body 27A Lower stopper piece 30 Rotor (drive mechanism) 31 Moving screw section (feed screw mechanism) 32 Valve stem holder (feed screw mechanism) 32A pressure equalization hole 32B spiral groove 33 Push nut 36 Support ring 37 Upper stopper body 37A Upper stopper piece 40 Can 40A bottom 40B can sidewall 41 Receiving part 41A Bottom 41B Receiving side wall 42 Welded section 50 Stator (drive mechanism) V center axis H horizontal line

Claims

1. A cylindrical can and a valve body having a valve chamber through which a fluid flows; a receiving portion provided on the can side of the valve body and having a ring-shaped bottom and a receiving side wall disposed on the outer edge of the bottom and covering the outer periphery of the end of the can side wall of the can; a welded portion joining the receiving side wall and the can side wall; a valve stem disposed inside the can; a drive mechanism for raising and lowering the valve stem; a valve element connected to the valve stem and moving toward and away from a valve seat in the valve chamber in conjunction with the elevation of the valve stem; An electrically driven valve comprising:

2. The weld is located at the upper end of the receiving side wall. The electrically driven valve according to claim 1 .

3. The valve body and the receiving portion are integrally formed by a single member.

3. The electrically driven valve according to claim 1 or 2.

4. The valve body and the receiving portion are formed separately from each other using different materials.

3. The electrically driven valve according to claim 1 or 2.

5. The drive mechanism includes a rotor that rotates integrally with the valve body, a stator that rotates the rotor, and a feed screw mechanism that raises and lowers the valve body.

3. The electrically driven valve according to claim 1 or 2.

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