Motor valve and refrigeration cycle system using the same

Abstract

To provide a motor valve that enables improvement of pressure resistant performance of a case by devising a configuration on the other end side of the case, and a refrigeration cycle system using the motor valve.SOLUTION: In a motor valve 100, a case 61 has a flat surface part 61b, a cylindrical part 61a and a curved surface part 61c. A tangential line of a flat surface part connection arc in a first boundary region Br1 extends in a direction along the flat surface part 61b. A tangential line of a cylindrical part connection arc in a second boundary region Br2 extends in a direction along the cylindrical part 61a. Parallel positioning means is the flat surface part 61b that positions one end part of the case 61 and the other end part of a valve element 10 in parallel with each other. Pressing force buffering means is the curved surface part 61c comprising one or more arcs when the case 61 is viewed from a longitudinal cross section, and when pressing force F1 in an axis L direction is applied to an outer surface 61ba of the flat surface part 61b, the curved surface part 61c is bent to buffer the pressing force F1.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electrically operated valve having a parallel positioning means and a pressing force buffering means, and a refrigeration cycle system using the same. [Background technology]

[0002] Patent Document 1 describes an electric valve 900 (hereinafter referred to as a "conventional electric valve") as shown in FIG. 9, which comprises a valve body 910 and a case 961 welded to the valve body 910, where the case 961 has a cylindrical portion 961a extending in the axial direction L, and a disk portion 961d which has a circular shape when viewed from the axial direction L and is fixed to one end of the cylindrical portion 961a via a weld W1.

[0003] Although not explicitly stated in Patent Document 1, for example, when assembling the case 961 to the valve body 910, it is considered that the case 961 is butted against the valve body 910 while applying a pressing force in the axial direction L to the disc portion 961d using a pressing jig (not shown), and the two are fixed to each other via the welded portion W2.

[0004] However, because the disk portion 961d is fixed to the case 961 via the welded portion W1, the horizontality of the disk portion 961d is relatively low. Due to this low horizontality of the disk portion 961d, when the disk portion 961d is pressed toward the other end in the direction of the axis L by a pressing jig, the case 961 is tilted with respect to the axis L, and one end of the case 961 and the other end of the valve body 910 cannot be positioned parallel to each other, and a gap is generated, which may cause poor welding at the welded portion W2 (hereinafter referred to as "Conventional problem 1 (poor welding due to difficulty in parallel positioning)").

[0005] In addition, taking into consideration that the welding heat generated at the welded portion W2 will cause the case 961 itself and the air inside the case 961 to expand, it was necessary to set the pressing force on the disc portion 961d in the direction of the axis L relatively large in order to suppress misalignment of the case 961 relative to the valve body 910.

[0006] Therefore, when assembling the case 961 to the valve body 910, a relatively large pressing force toward one end in the direction of the axis L is applied to the disc portion 961d, causing an extremely large stress concentration at the welded portion W1, which is the connection between the disc portion 961d and the cylindrical portion 961a, and there is a risk of reducing the strength of the welded portion W1 (hereinafter referred to as "Conventional problem 2 (large stress concentration caused by pressing force during assembly)").

[0007] Thus, in conventional motor-operated valves, conventional problem 1 (poor welding due to difficulty in parallel positioning) and conventional problem 2 (large stress concentration caused by the pressing force during assembly) reduce the strength of the weld W2 between the case 961 and the valve body 910, and the weld W1 between the disk portion 961d and the cylindrical portion 961a, and in the worst case, there was a risk of the case 961 bursting under normal operating pressure conditions. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] China Patent Application Publication No. 108626413 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide an electric valve and a refrigeration cycle system using the same that can simultaneously solve the conventional problems 1 and 2 and improve the pressure resistance performance of the case by devising a configuration for the other end side of the case. [Means for solving the problem]

[0010] In order to achieve the above object, there is provided a valve body having a valve port, a valve element which controls the opening area of ​​the valve port, a drive section which moves the valve element back and forth, a parallel positioning means, and a pressing force buffering means, wherein the drive section comprises a drive member, and a case which houses the drive member and is connected to the valve body and is integrally formed with the valve body, and the case comprises a planar portion which has a circular shape when viewed from the axial direction, a cylindrical portion which extends in the axial direction and has a cylindrical shape, and a curved surface portion which continuously connects the planar portion and the cylindrical portion and has an annular shape when viewed from the axial direction, and when viewed from the longitudinal section of the case, the curved surface portion is connected to the planar portion in a first boundary region and has a predetermined radius of curvature a cylindrical portion connecting arc that connects to the cylindrical portion in a first boundary region and has a predetermined radius of curvature, a tangent to the flat portion connecting arc in the first boundary region extending in a direction along the flat portion, and a tangent to the cylindrical portion connecting arc in the second boundary region extending in a direction along the cylindrical portion, the parallel positioning means is the flat portion that positions one end of the case and the other end of the valve body parallel to each other, and the pressing force buffering means is the curved portion consisting of one or more arcs when viewed from a longitudinal cross section of the case, and when an axial pressing force is applied to the outer surface of the flat portion, the curved portion bends to buffer the pressing force.

[0011] In the above motor-operated valve, when the radii of curvature of the flat portion connecting arc and the cylindrical portion connecting arc are Rf and Rt, respectively, the radii may be set to satisfy the relationship 1≦Rf / Rt<2.

[0012] In addition, in the above-mentioned motor-operated valve, when the radii of curvature of the flat portion connecting arc and the cylindrical portion connecting arc are Rf and Rt, respectively, the inner diameter of the cylindrical portion is D2, and the diameter of the flat portion is D1, the relationship may be set as D2 = Rf + Rt + D1.

[0013] In addition, in the above-mentioned motor-operated valve, when the case is viewed from a longitudinal cross section, the curved portion may consist of two or more arcs, and the center of the flat portion connecting arc may be positioned on one end side rather than the other end side of the cylindrical portion.

[0014] Moreover, the above-mentioned electric valve may further include a case dimensional error absorbing means, the case being integrally molded by press processing, and the case dimensional error absorbing means being the curved portion, and when the pressing force is applied to the outer surface of the flat portion, the curved portion is deflected to move only the flat portion in the axial direction, thereby absorbing the dimensional error of the case.

[0015] Moreover, the above-mentioned motor-operated valve may further include an abnormally high pressure buffer means, wherein the case is integrally molded by pressing, and the thicknesses of the planar portion, the curved portion and the cylindrical portion at least in the vicinity of the second boundary region are uniform, and the abnormally high pressure buffer means is the planar portion and the curved portion, and when an abnormally high pressure in the axial direction is applied to the inner surface of the planar portion, the planar portion and the curved portion are smoothly deflected so as to be continuously connected to the cylindrical portion, and are deformed into an approximately hemispherical shape, thereby buffering the load due to the abnormally high pressure.

[0016] The present invention may also be directed to a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, in which the motor-operated valve is used as the expansion valve. Effect of the Invention

[0017] According to the present invention, by devising a configuration for the other end side of the case, it is possible to provide an electric valve and a refrigeration cycle system using the same that can simultaneously solve the conventional problems 1 and 2 and improve the pressure resistance performance of the case. [Brief description of the drawings]

[0018] [Figure 1] 1 is a vertical cross-sectional view showing a motor-operated valve according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged view showing only the other end of the case in FIG. [Diagram 3] 5A to 5C are explanatory diagrams showing an assembly process of the motor-operated valve in the embodiment. [Figure 4] 4 is an explanatory diagram showing a deformed state of the case in FIG. 3. FIG. [Diagram 5] 5 is an explanatory diagram showing a state in which a case is deformed due to an internal pressure fluctuation of the motor-operated valve in the embodiment; FIG. [Figure 6] 10 is an enlarged view (corresponding to FIG. 2) showing the other end of the case in case modification 1 of the present embodiment. FIG. [Figure 7] 10 is an enlarged view (corresponding to FIG. 2) showing the other end of the case in case modification 2 of the present embodiment. FIG. [Figure 8] FIG. 1 is a diagram showing a refrigeration cycle system of the present invention. [Figure 9] FIG. 1 is a vertical cross-sectional view showing a motor-operated valve according to a conventional technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of the present invention will be described in detail with reference to Figures 1 to 8. However, the present invention is not limited to this embodiment.

[0020] <Terminology> In the present specification and claims, the terms "left", "right", "upper" and "lower" refer to the directions shown in Figs. 1-7. In the present specification and claims, the terms "one end" and "other end" refer to the lower end and upper end in the drawings. In the present specification and claims, the term "longitudinal section" refers to the plane of the cut surface obtained when an object is cut in the axial direction. In the present specification and claims, the term "normal operating pressure" refers to the pressure used in the motor-operated valve during normal operation. In the present specification and claims, the term "maximum operating pressure" refers to the normal operating pressure plus a specified margin, which is the maximum pressure at which the motor-operated valve functions without hindrance under normal operating conditions. In the present specification and claims, the term "pressure resistance pressure" refers to the maximum operating pressure plus a specified margin, which is the maximum pressure at which the motor-operated valve can function without hindrance but is not guaranteed to function without hindrance, but which can prevent leakage to the outside. In the present specification and claims, "abnormally high pressure" refers to "high pressure that deviates from the maximum operating pressure that is equal to or lower than the withstand pressure (maximum operating pressure < abnormally high pressure ≦ withstand pressure)." In the present specification and claims, "dimensional tolerance" refers to "the difference between the maximum allowable dimension and the minimum allowable dimension within the allowable range." In the present specification and claims, "minimum allowable dimension" refers to "the minimum dimension that can be tolerated as an actual dimension." In the present specification and claims, "flat surface portion connecting arc" refers to "an arc that is connected to the flat surface portion and has a predetermined radius of curvature." In the present specification and claims, "cylindrical portion connecting arc" refers to "an arc that is connected to the cylindrical portion and has a predetermined radius of curvature."

[0021] (Present embodiment) <About the motor-operated valve configuration> A motor-operated valve 100 according to this embodiment of the present invention will be described with reference to Fig. 1. The motor-operated valve 100 is mainly composed of a valve body 10, a support member 20, a drive shaft 30, a valve body portion 40, a coil member 50, and a stepping motor 60 (drive portion). Each component of the motor-operated valve 100 will be described below in order.

[0022] Here, although details will be described later, the motor-operated valve 100 of this embodiment employs a parallel positioning means for positioning one end (lower end) of the case 61 (see FIG. 1) and the other end (upper end) of the valve body 10 (see FIG. 1) in parallel with each other, and a pressing force buffering means for buffering the pressing force F1 (see FIG. 3), thereby solving the above-mentioned problems of the conventional problem 1 (poor welding due to difficulty in parallel positioning) and conventional problem 2 (large stress concentration caused by pressing force during assembly), and improving pressure resistance. Furthermore, the motor-operated valve 100 of this embodiment considers concerns (concern 1 (reduced productivity due to detection of dimensional errors in the case) and concern 2 (burst of flat surface due to abnormally high pressure)) that accompany the adoption of the parallel positioning means and pressing force buffering means, and employs a case dimensional error absorbing means, an abnormally high pressure buffering means, etc. to resolve these concerns.

[0023] The valve body 10 is formed in a cylindrical shape from a metal such as stainless steel. The valve body 10 is provided with a valve seat member 11 formed separately from the valve body 10 so as to close the lower end. A valve port 11a opens in the center of the valve seat member 11. The valve body 10 forms a valve chamber 12 inside.

[0024] A first coupling pipe 1 serving as a flow path for a fluid such as a refrigerant is connected to one outer periphery side of the valve body 10, and this first coupling pipe 1 is in communication with a valve chamber 12. A second coupling pipe 2 in contact with a valve seat member 11 is connected to the bottom side of the valve body 10, and this second coupling pipe 2 is in communication with the valve chamber 12 via a valve port 11a. The first coupling pipe 1 and the second coupling pipe 2 are made of materials such as copper or stainless steel, and are fixed to the valve body 10 by brazing or the like.

[0025] The support member 20 includes a substantially cylindrical holder portion 21 made of a resin material such as polyphenylene sulfide (PPS), and a stainless steel fixing portion 22 that is integrally provided by insert molding on the other end of the holder portion 21. The support member 20 is fixed to the valve body 10 by the fixing portion 22 through welding.

[0026] The holder part 21 is disposed so that its axis overlaps with the axis L passing through the axis of the valve port 11a. A screw hole 23, a bearing hole 24, and a slide hole 25 are formed concentrically in the center of the holder part 21, aligned in the direction of the axis L so as to penetrate the holder part 21. A female thread portion 23a is formed on the inner peripheral surface of the screw hole 23, and a male thread portion 31a of a drive shaft 30 described later is screwed into the female thread portion 23a. A guide portion 32 of the drive shaft 30 described later is slidably engaged with the inner peripheral surface of the bearing hole 24. The slide hole 25 is disposed closer to the valve port 11a, and is formed with a larger diameter than the bearing hole 24. A valve body portion 40 described later is slidably engaged with the slide hole 25.

[0027] Guide rail 26 consisting of a helical ridge is integrally formed on the outer circumferential surface of holder portion 21. Adjacent winding portions of guide rail 26 are arranged with a gap therebetween. Guide rail 26 is arranged so that its axis overlaps axis L, and guides each winding portion of coil portion 51 from one side or both sides so that coil member 50 described later can rotate in the circumferential direction by screwing coil portion 51 into guide rail 26.

[0028] The drive shaft 30 is formed in a cylindrical rod shape using a metal such as stainless steel. The drive shaft 30 is formed with a threaded portion 31, a guide portion 32, and a flange portion 33 arranged at an end of the guide portion 32 near the valve port 11a, which are aligned in the axial direction L. The threaded portion 31 is formed with a male threaded portion 31a, which is screwed into a female threaded portion 23a of the holder portion 21, thereby converting the rotational motion of the drive shaft 30 into a linear motion. The guide portion 32 is slidably engaged with the inner circumferential surface of the bearing hole 24, thereby guiding the movement of the drive shaft 30 in the axial direction L. The flange portion 33 rotatably engages the valve body portion 40 described later. In this embodiment, the female threaded portion 23a and the male threaded portion 31a are right-handed threads.

[0029] The valve body portion 40 includes a valve holder 41 , a valve body 42 , a washer 43 , a spring receiver 44 , and a compression coil spring 45 .

[0030] The valve holder 41 is formed in a cylindrical shape with an outer diameter substantially the same as the inner diameter of the slide hole 25 of the holder part 21. The valve holder 41 is engaged with the slide hole 25 so as to be slidable in the axial direction L along the slide hole 25.

[0031] The valve element 42 is needle-shaped and is fixed to the lower end 41a of the valve holder 41 on the valve port 11a side so that the tip of the needle faces the valve port 11a. The valve element 42 adjusts the opening of the valve port 11a relative to the valve seat between the maximum valve opening and the minimum valve opening (or fully closed state), thereby controlling the opening area of ​​the valve port 11a and thereby adjusting the flow rate.

[0032] The flange portion 33 of the drive shaft 30 is rotatably hooked to the upper end portion 41b of the valve holder 41 on the side opposite to the valve port 11a side. Specifically, the flange portion 33 of the drive shaft 30 sandwiches a washer 43 between the upper end portion 41b of the valve holder 41 and the drive shaft 30, and the upper end portion 41b of the valve holder 41 is rotatably hooked by the flange portion 33. Due to this engagement, the valve holder 41 is supported by the drive shaft 30 so as to be movable in the axial direction L and to be rotatable about the axial direction L. An opening larger than the radial movable range of the drive shaft 30 is formed at the upper end portion 41b of the valve holder 41. In addition, a spring receiver 44 is provided in the valve holder 41 so as to be movable in the axial direction L. A compression coil spring 45 is attached between the spring receiver 44 and the valve body 42 in a compressed state with a predetermined load applied. As a result, the spring receiver 44 is biased toward the other end and comes into contact with one end of the drive shaft 30 .

[0033] The coil member 50 is integrally provided with a coil spring-shaped coil portion 51 and a claw portion 52 that protrudes radially outward from one end of the coil portion 51. The coil portion 51 is screwed to the guide rail 26 of the holder portion 21 so as to be rotatable in the circumferential direction. The claw portion 52 can abut against a protrusion 67 of a magnet rotor 62 described later, and the rotation of the magnet rotor 62 pushes the coil member 50 around in the circumferential direction via the claw portion 52. As a result, the coil member 50 abuts against an upper limit stopper (not shown) or a lower limit stopper (not shown), restricting the rotation of the coil member 50 and also restricting the rotation of the magnet rotor 62. Therefore, the valve body portion 40 is restricted from moving beyond a position where the valve body portion 40 is at the maximum opening degree or the position where the valve body portion 40 is at the minimum opening degree (or the valve is closed). The coil member 50 can be easily manufactured by forming a metal wire such as stainless steel.

[0034] The stepping motor 60 includes a case 61, a magnet rotor 62 (a driving member), and a stator coil (not shown).

[0035] The case 61 is made of a metal such as stainless steel and is constructed as an integral part, has a bottomed portion at the other end, has a generally cylindrical shape that opens at one end, and houses the magnet rotor 62 inside. A joint Cs which is one end of the case 61 and the upper end of the valve body 10 are hermetically fixed by a welded portion W.

[0036] Although details will be described later, in this embodiment, by devising a configuration for the other end side of the case 61, it is possible to simultaneously solve the conventional problems 1 and 2 and improve pressure resistance.

[0037] The magnet rotor 62 integrally comprises a cylindrical magnet portion 64 whose outer periphery is magnetized with multiple poles, and a disk portion 65 closing one end of the magnet portion 64. The magnet rotor 62 is fixed to the drive shaft 30 via a metal fitting 66 integrally formed in the center of the disk portion 65. As a result, the magnet rotor 62 is provided within the case 61 so as to be rotatable about the axis L of the drive shaft 30. The drive shaft 30 is the rotation axis of the magnet rotor 62.

[0038] The stator coil is disposed on the outer circumferential surface of the case 61, and when a pulse signal is given to the stator coil, the magnet rotor 62 is rotated according to the number of pulses. The stator coil corresponds to a stepping motor 60.

[0039] When the magnet rotor 62 rotates, the drive shaft 30 rotates together with the magnet rotor 62, and the male thread portion 31a and the female thread portion 23a act as a screw feed, causing the drive shaft 30 to move in the direction of the axis L, and the valve body portion 40 to advance and retreat relative to the valve port 11a. This changes the opening of the valve port 11a relative to the valve seat, and controls the flow rate of the fluid flowing from the first joint pipe 1 to the second joint pipe 2 (or from the second joint pipe 2 to the first joint pipe 1).

[0040] <Configuration of the other end of the case> Here, the configuration of the other end side of the case 61 will be described with reference to FIG. 2. As shown in FIG. 2, the case 61 has a bilaterally symmetrical shape, so only the shape of the right half will be described. The case 61 includes a cylindrical portion 61a extending in the axial direction L and having a cylindrical shape, a flat portion 61b having a circular shape as viewed from the axial direction L, and a curved portion 61c that continuously and smoothly connects the cylindrical portion 61a and the flat portion 61b, has a convex shape toward the outer surface side, and has a ring shape as viewed from the axial direction L. The thickness t of the flat portion 61b, the curved portion 61c, and the cylindrical portion 61a of the case 61 is uniform. The curved portion 61c in this embodiment is composed of one arc (first arc Ca1).

[0041] Specifically, as shown in FIG. 2, when the case 61 is viewed from a vertical cross section, the flat portion 61b extends along a direction perpendicular to the axis L. In addition, the flat portion 61b is a parallel positioning means that is positioned parallel to a joint Cs (see FIG. 1), which is one end of the cylindrical portion 61a, as will be described in detail later. In addition, the first arc Ca1 has a curvature radius R1 of the first arc Ca1, and is a flat portion connecting arc that connects to the flat portion 61b in the first boundary region Br1, and is a cylindrical portion connecting arc that connects to the cylindrical portion 61a in the second boundary region Br2. In addition, a tangent to the first arc Ca1 (flat portion connecting arc) in the first boundary region Br1 extends in a direction along the flat portion 61b, and a tangent to the first arc Ca1 (cylindrical portion connecting arc) in the second boundary region Br2 extends in a direction along the cylindrical portion 61a. This allows the curved surface portion 61c to be continuously and smoothly connected to the cylindrical portion 61a and the flat surface portion 61b.

[0042] The central angle θ1 formed by the first arc Ca1 (center O1, radius of curvature R1) is 90°. A straight line connecting the first boundary region Br1 and the center O1 of the first arc Ca1 is parallel to the axis L passing through the center of the cylindrical portion 61a, and a straight line connecting the second boundary region Br2 and the center O1 of the first arc Ca1 is perpendicular to the axis L passing through the center of the cylindrical portion 61a.

[0043] Here, in the curved portion 61c', if the radius of curvature of the plane portion connecting arc is Rf and the radius of curvature of the cylindrical portion connecting arc is Rt, they are each the same as the radius of curvature R1 of the first arc Ca1, that is, Rf / Rt = 1, and since they do not have an extremely small radius of curvature, it is possible to suppress the occurrence of stress concentration at the other end of the curved portion 61c (first boundary region Br1) and one end of the curved portion 61c (second boundary region Br2).

[0044] Furthermore, assuming that the diameter of the flat portion 61b is D1 and the inner diameter of the cylindrical portion 61a is D2, then they satisfy D2=D1+2×R1(=D1+Rf+Rt) (Formula 1), as shown in Fig. 2. Therefore, using this (Formula 1), the diameter D1 of the flat portion 61b (=D2-2×R1) can be set by combining only two parameters (D2 and R1), so that the case 61 can be smoothly designed and the dimensions of the case 61 can be easily managed.

[0045] In this embodiment, the thickness t of the flat surface portion 61b, the curved surface portion 61c, and the cylindrical portion 61a is uniform, but the present invention is not limited thereto. For example, it is sufficient that the thicknesses of the flat surface portion 61b, the curved surface portion 61c, and the cylindrical portion 61a at least in the vicinity of the second boundary region Br2 are uniform. As a result, the thickness t of one end side (lower side in FIG. 1) of the cylindrical portion 61a may be made larger than the thickness t of the other case 61. In this embodiment, the one end side (lower side in FIG. 1) of the cylindrical portion 61a has a cylindrical shape, but the present invention is not limited thereto. For example, the thickness t may be a flange shape or a shape having a plurality of recesses along the circumferential direction.

[0046] <Assembly process of motor-operated valve> From here, the deformation state of the case 61 in the assembly process of the motor-operated valve 100 will be described with reference to Figures 3 and 4. Note that Figures 3 and 4 are intentionally exaggerated to emphasize the change in the axis L direction of the curved surface portion 61c. Also, (I), (II), and (III) in Figure 3 show the state immediately before pressing, the pressed state, and the state immediately after pressing, respectively. Furthermore, the valve body 10 located on one end side of the motor-operated valve 100 is firmly held by a holding jig Cl. In addition, in the assembly process, only the curved surface portion 61c bends in the axis L direction, while the shapes of the flat surface portion 61b and the cylindrical portion 61a remain unchanged.

[0047] First, in the state immediately before pressing shown in FIG. 3(I), the specific shape of the case 61 corresponds to that shown in FIG. 4(I), and after the pressing tool Pt moves in the pressing direction M1, it abuts against the flat portion 61b of the case 61.

[0048] Next, in the (II) pressing state shown in Fig. 3, the pressing jig Pt applies a pressing force F1 to the outer surface 61ba (see Fig. 4) of the flat portion 61b. At this time, the flat portion 61b, which is a parallel positioning means, is always positioned parallel to the joint Cs (see Fig. 1), which is one end of the cylindrical portion 61a, so that the case 61 does not tilt with respect to the axis L, and the joint Cs of the cylindrical portion 61a is abutted flush with the other end of the valve body 10 without any gaps, forming a welded portion W with relatively high accuracy. This improves the pressure resistance of the case 61.

[0049] Therefore, in the electric valve 100 of this embodiment, by adopting a flat portion 61b, which is a parallel positioning means, in the case 61, the conventional problem 1 (poor welding due to difficulty in parallel positioning) can be eliminated and the pressure resistance performance of the case 61 can be improved.

[0050] In addition, the pressing force F1 in the pressing state (II) is set relatively large in consideration of the expansion of the case 61 itself and the air inside the case 61 due to welding heat, and suppresses positional deviation. When this pressing force F1 is temporarily applied to the outer surface 61ba of the flat surface portion 61b, as shown in Fig. 4 (II), only the curved surface portion 61c, which is a pressing force buffering means, bends toward one end while maintaining the shape of the flat surface portion 61b, generating a repulsive force F2 and buffering the relatively large pressing force F1. At this time, the shape of the case 61 is such that the flat surface portion 61b, the curved surface portion 61c, and the cylindrical portion 61a are continuously and smoothly connected, so that it is possible to suppress the occurrence of stress concentration in the case 61. Furthermore, when only the curved portion 61c, which is the pressure force buffering means, bends toward one end, the bending of the curved portion 61c in any longitudinal cross section is uniform, and the horizontality of the flat portion 61b is always maintained, so there is no effect on the positioning accuracy of the parallel positioning means (flat portion 61b).

[0051] Therefore, in the electric valve 100 of this embodiment, by adopting the curved portion 61c, which acts as a pressing force buffering means, in the case 61, the conventional problem 2 (large stress concentration caused by the pressing force during assembly) can be eliminated and damage to the case 61 can be suppressed, thereby improving the pressure resistance performance of the case 61.

[0052] Next, in the state immediately after pressing shown in Fig. 3 (III), the pressing jig Pt moves in the separating direction M2. At this time, due to the repulsive force F2 of the curved surface portion 61c, the flat surface portion 61b is restored to the shape of the curved surface portion 61c before deformation, that is, the shape of the case 61 before deformation, as shown in Fig. 4 (III), in a state in which it is in contact with the pressing jig Pt.

[0053] As described above, the motor-operated valve 100 of this embodiment simultaneously employs the flat portion 61b as a parallel positioning means and the curved portion 61c as a pressing force buffering means, so that when a pressing force F1 is temporarily applied to the outer surface 61ba of the flat portion 61b, the joint Cs of the cylindrical portion 61a is flush with the other end of the valve body 10 without any gaps, and only the curved portion 61c is continuously and smoothly connected to the flat portion 61b and the cylindrical portion 61a and can bend. As a result, the motor-operated valve 100 of this embodiment simultaneously solves the conventional problem 1 (poor welding due to difficulty in parallel positioning) and the conventional problem 2 (large stress concentration caused by pressing force during assembly), and can improve the pressure resistance of the case 61.

[0054] <Regarding concerns> In the motor-operated valve 100 of this embodiment, the case 61 is integrally formed. Here, when the case 61 is formed by cutting, the dimensional length of the case 61 in the direction of the axis L can be controlled with extremely high precision, but there is a risk of high manufacturing costs. In contrast, when the case 61 is integrally formed by pressing instead of cutting, a single plate-shaped material is deep-drawn, so that the manufacturing costs can be reduced, but the case 61 has a flat portion 61b with a relatively small degree of dimensional error (individual difference) and work hardening in the direction of the axis L. Therefore, the inventor considers concerns 1 and 2 when the case 61 is integrally formed by pressing in order to reduce the manufacturing costs of the case 61.

[0055] <Regarding concern 1 (Loss of productivity due to detection of case dimensional errors)> Although not shown in the figure, generally, when assembling a case 61 having a dimensional error (individual difference) in the axial L direction to the valve body 10, in order to absorb this dimensional error in the axial L direction, it is necessary to use a contact sensor or the like to detect the position where the pressing jig Pt abuts against the flat portion 61b of the case 61, and then move the pressing jig Pt from this reference abutment position in the pressing direction M1 by a predetermined pressing amount Pv.

[0056] However, since it is necessary to detect the contact position of the holding jig Pt each time the assembly process of the case 61 to the valve body 10 is performed on the manufacturing line, there was a concern that the productivity of the electric valve 100 would be significantly reduced (hereinafter referred to as "Concern 1 (reduced productivity due to detection of dimensional errors of the case)").

[0057] <Methods for absorbing case dimensional errors> In contrast, in this embodiment, the curved portion 61c is used as a case dimensional error absorbing means, and while in the pressed state (see (II) of Figure 3), the actual dimension of the cylindrical portion length L1 remains unchanged, only the curved portion 61c bends, thereby absorbing the dimensional error (individual difference) of the case 61 and eliminating concern 1 (reduced productivity due to detection of dimensional error in the case).

[0058] Since the case 61 is an important component when determining the length of the motor-operated valve 100 in the axial L direction, the dimensional tolerance of the case 61 in the axial L direction, that is, the difference between the maximum allowable dimension and the minimum allowable dimension within the allowable range, is determined at the design stage. Therefore, in this embodiment, as shown in FIG. 3 (II), first, a value obtained by subtracting a predetermined pushing amount Pv from this minimum allowable dimension Lmin (≦actual case length Lo) is calculated in advance as the pressed case length Ld. Then, the pressing jig Pt is moved in the pressing direction M1 so that the length of the case 61 in the axial L direction becomes the predetermined pressed case length Ld for all cases.

[0059] Specifically, in the (I) immediately before pressing state shown in Fig. 3, the cylindrical portion 61a and the curved surface portion 61c have the actual cylindrical portion length L1 (unchanged) and the actual curved surface portion length L2 (variable) in the axial direction L, respectively, and the case 61 has the actual case length L0 (= L1 + L2) having a dimensional error (individual difference) in the axial direction L. Next, in the (II) pressed state shown in Fig. 3, the pressing jig Pt is moved in the pressing direction M1 so that the actual case length L0 becomes the pressed case length Ld. At this time, the cylindrical portion 61a and the curved surface portion 61c have the actual cylindrical portion length L1 (unchanged) and the pressed curved surface portion length L2' (variable) in the axial direction L, respectively, and the case 61 has the pressed case length Ld (= L1 + L2') in the axial direction L. 3, the case 61, the cylindrical portion 61a, and the curved portion 61c each have the same length in the axial direction L as in the state immediately before pressing (I), that is, the actual case length L0, the actual cylindrical portion length L1 (unchanged), and the actual curved portion length L2 (variable). Note that, in the assembly process of this embodiment, the maximum deflection of the curved portion 61c, which is a case dimensional error absorbing means, is made larger than the dimensional tolerance, so that the dimensional error (individual difference) of the case 61 can be reliably absorbed.

[0060] In this embodiment, in the pressed state (II) shown in Fig. 3, the pressing tool Pt is pressed into the flat surface portion 61b so that the length of the case 61 in the axial direction L becomes the predetermined pressed case length Ld. As a result, only the curved surface portion 61c, which is the case dimensional error absorbing means, is deflected, and the dimensional error (individual difference) of the case 61 can be absorbed, thereby eliminating the first concern (reduced productivity due to detection of dimensional error of the case) and improving the productivity of the motor-operated valve 100.

[0061] <Regarding concern 2 (rupture of flat surface due to abnormally high pressure)> In recent years, in order to improve the coefficient of performance (COP) in refrigeration cycle systems, there has been a demand for the adoption of carbon dioxide and other refrigerants, which have a relatively high operating pressure compared to the HFCs, HFOs, and other refrigerants that have been conventionally used.

[0062] Therefore, in the electric valve 100 of this embodiment, when carbon dioxide is used as the refrigerant, the operating pressure is relatively high, and therefore there is a risk that a relatively large force caused by the pressure toward the other end in the direction of the axis L will be applied to the flat portion 61b and the curved portion 61c.

[0063] Generally, when an internal pressure is applied to a thin-walled cylindrical pressure vessel with uniform thickness, circumferential stress in the circumferential direction and axial stress in the axial direction are generated as stresses to withstand the internal pressure. Although a detailed explanation is omitted, this axial stress is 1 / 2 the circumferential stress. This explanation can be applied to the case 61 having a substantially cylindrical shape in the same way.

[0064] Since the axial stress is half the circumferential stress, theoretically, if the thickness t of the case 61 is uniform, there is no risk that the flat portion 61b and the curved portion 61c will expand in the axial L direction and burst before the cylindrical portion 61a expands in the circumferential direction and bursts.

[0065] However, when the case 61 is integrally molded by press working, a single plate-shaped material is deep-drawn to form a cylindrical shape with a bottom, which results in variation in the degree of work hardening in the flat portion 61b, the curved portion 61c, and the cylindrical portion 61a.

[0066] Specifically, in the press working, the flat surface portion 61b maintains the thickness of the base material, while the cylindrical portion 61a and the curved surface portion 61c are plastically deformed by drawing. Therefore, since the flat surface portion 61b is hardened less than the cylindrical portion 61a and the curved surface portion 61c, when an abnormally high pressure (maximum operating pressure<abnormally high pressure≦withstand pressure) is applied to the inside of the case 61, the flat surface portion 61b becomes easily deformed, and there was a concern that it may burst (hereinafter referred to as "concern 2 (burst of flat surface portion due to abnormally high pressure)").

[0067] <About abnormally high pressure buffering measures> 5, the case 61 is integrally formed by pressing, and the thickness t of the flat surface portion 61b, the curved surface portion 61c, and the cylindrical portion 61a at least in the vicinity of the second boundary region Br2 is made uniform, and the flat surface portion 61b and the curved surface portion 61c serve as an abnormally high pressure buffer. When an abnormally high pressure in the axial direction L is temporarily applied to the inner surfaces of the flat surface portion 61b and the curved surface portion 61c, the flat surface portion 61b and the curved surface portion 61c are smoothly deflected so as to be continuously connected to the cylindrical portion 61a, and are deformed into a substantially hemispherical shape, thereby buffering the temporary load due to the abnormally high pressure and eliminating the second concern (rupture of the flat surface portion due to the abnormally high pressure).

[0068] From here, the abnormally high pressure buffer means will be specifically described with reference to Fig. 5. Note that Fig. 5 is intentionally exaggerated in order to emphasize the change in the axis L direction of the flat surface portion 61b and the curved surface portion 61c.

[0069] First, in the motor-operated valve 100 of this embodiment, the thickness t of the case 61 is appropriately selected so that the shape of the case 61 is maintained in the normal use pressure (Pnl) state (see the solid line in FIG. 5) by prior pressure resistance design. Therefore, in the normal use pressure (Pnl) state, the flat surface portion 61b, the curved surface portion 61c, and the cylindrical portion 61a have a uniform thickness t and are continuously and smoothly connected to each other. Therefore, in the normal use pressure (Pnl) state, the shape of the case 61 is maintained, so no deformation occurs.

[0070] On the other hand, in the electric valve 100 of this embodiment, when in an abnormally high pressure (Pabn) state (see dashed line in Figure 5), the abnormally high pressure Pabn in the axial L direction is applied to the inner surface 61bb of the flat portion 61b, and the flat portion 61b and the curved portion 61c are intentionally smoothly deflected so as to be continuously connected to the cylindrical portion 61a, and are deformed into an approximately hemispherical shape consisting of the other end side curved portion 61bc and the curved portion 61c, thereby cushioning the temporary load due to the abnormally high pressure.

[0071] Thus, in the motor-operated valve 100 of this embodiment, the case 61 does not deform in the normal operating pressure (Pnl) state, but in the abnormally high pressure (Pabn) state, the flat surface portion 61b and the curved surface portion 61c, which are abnormally high pressure buffer means, are smoothly bent so as to be continuously connected to the cylindrical portion 61a, and are deformed into a substantially hemispherical shape. As a result, the motor-operated valve 100 of this embodiment can eliminate concern 2 (burst of the flat surface portion due to abnormally high pressure) and prevent leakage to the outside.

[0072] <About the reversible deformation of abnormally high pressure buffer means> As described above, in the abnormally high pressure buffer means, the flat surface portion 61b is less hardened than the curved surface portion 61c, so if the deflection of the flat surface portion 61b becomes too large in the abnormally high pressure (Pabn) state, the other end side curved surface portion 61bc after deformation may be plastically deformed. As a result, even if the abnormally high pressure (Pabn) state transitions back to the normal use pressure (Pnl) state, the other end side curved surface portion 61bc may not reversibly return to the flat surface portion 61b.

[0073] In response to this, the inventors conducted intensive research using simulations and found that by setting an upper limit value for the diameter D1 of the flat portion 61b, the deflection of the other-end curved portion 61bc can be made relatively small in an abnormally high pressure (Pabn) state, in other words, only elastic deformation occurs in the other-end curved portion 61bc, and it can reversibly and reliably return to the flat portion 61b.

[0074] Specifically, the upper limit of the diameter D1 of the flat portion 61b is set to 1 / 3 or less of the inner diameter D2 of the cylindrical portion 61a (D1≦1 / 3×D2). Preferably, the upper limit of the diameter D1 of the flat portion 61b is set to 1 / 4 or less of the inner diameter D2 of the cylindrical portion 61a (D1≦1 / 4×D2), and more preferably, the upper limit of the diameter D1 of the flat portion 61b is set to 1 / 5 or less of the inner diameter D2 of the cylindrical portion 61a (D1≦1 / 5×D2). The lower limit of the diameter D1 of the flat portion 61b may be any area that allows the pressing tool Pt to press, and is set to, for example, a value that exceeds twice the wall thickness t of the case 61.

[0075] In addition, between the diameter D1 of the flat portion 61b and the inner diameter D2 of the cylindrical portion 61a, in addition to the aforementioned relationship D1≦1 / 3×D2, the relationship D1=D2-2×R1 is also satisfied according to the aforementioned (Equation 1).

[0076] In this way, in the electric valve 100 of this embodiment, the upper limit value of the diameter D1 of the flat portion 61b is set to less than one-third of the inner diameter D2 of the cylindrical portion 61a (D1≦1 / 3×D2), preferably less than one-quarter (D1≦1 / 4×D2), and more preferably less than one-fifth (D1≦1 / 5×D2), so that when the electric valve 100 transitions again from the abnormally high pressure (Pabn) state to the normal operating pressure (Pnl) state, the other end side curved portion 61bc can reversibly and reliably return to the flat portion 61b.

[0077] As described above, the motor-operated valve 100 of this embodiment simultaneously employs the flat surface portion 61b as a parallel positioning means and the curved surface portion 61c as a pressing force buffering means, thereby simultaneously resolving the conventional problem 1 (poor welding due to difficulty in parallel positioning) and the conventional problem 2 (large stress concentration caused by pressing force during assembly), and improving the pressure resistance of the case 61. In addition, since the motor-operated valve 100 of this embodiment has Rf / Rt=1, it is possible to suppress the occurrence of stress concentration at the other end (first boundary region Br1) of the curved surface portion 61c and at one end (second boundary region Br2) of the curved surface portion 61c. Furthermore, the motor-operated valve 100 of this embodiment satisfies D2=D1+2×R1 (=D1+Rf+Rt), and the diameter D1 of the flat surface portion 61b can be set by a combination of only two parameters, so that the design of the case 61 can be smoothly performed and the dimensional management of the case 61 can be easily performed. In addition, the motor-operated valve 100 of this embodiment generates deflection only in the curved surface portion 61c, which is the case dimensional error absorbing means, and can absorb the dimensional error (individual difference) of the case 61, thereby eliminating concern 1 (reduced productivity due to detection of dimensional error of the case) and improving the productivity of the motor-operated valve 100. Furthermore, the motor-operated valve 100 of this embodiment smoothly deflects the flat surface portion 61b and the curved surface portion 61c, which are the abnormally high pressure buffering means, so as to be continuously connected to the cylindrical portion 61a, and deforms them into a substantially hemispherical shape, thereby eliminating concern 2 (burst of the flat surface portion due to abnormally high pressure) and preventing leakage to the outside. Furthermore, in the electric valve 100 of this embodiment, the upper limit value of the diameter D1 of the flat portion 61b is set to less than one-third (D1≦1 / 3×D2), preferably less than one-quarter (D1≦1 / 4×D2), and more preferably less than one-fifth (D1≦1 / 5×D2) of the inner diameter D2 of the cylindrical portion 61a, thereby making it possible to reversibly change the distance between the flat portion 61b and the other end side curved portion 61bc.

[0078] (Variations 1 and 2 of the present embodiment) Case modifications 1 and 2 of this embodiment will be described with reference to Figs. 6 and 7. Case modifications 1 and 2 of this embodiment differ from the curved surface portion 61c of this embodiment, which is made of one arc, in that the curved surface portions 61c', 61c'' are made of multiple (two or three) arcs, but the other basic configurations are the same as in this embodiment. Here, the same configurations are given the same reference numerals, and duplicated explanations will be omitted. In Figs. 6 and 7, the diameter D1 of the flat portion 61b, the inner diameter D2 of the cylindrical portion 61a, and the wall thickness t of the case 61' are the same as in this embodiment, so that it can be visually understood that the length of the axial line L direction of the cases 61', 61'' in case modifications 1 and 2 of this embodiment can be reduced compared to the case 61 of this embodiment.

[0079] (Case variation 1 of this embodiment) First, the configuration of the other end side of case 61' in case modification 1 of this embodiment will be described with reference to Fig. 6. Case modification 1 of this embodiment differs from curved surface portion 61c of this embodiment in that curved surface portion 61c' is made up of two arcs (first arc Ca1' and second arc Ca2'), but the other basic configuration is the same as this embodiment. As shown in Fig. 6, case 61' has a bilaterally symmetrical shape, so only the shape of the right half will be used for the description.

[0080] <Configuration of the other end of the case> As shown in Fig. 6, the case 61' includes a cylindrical portion 61a extending in the direction of the axis L and having a cylindrical shape, a flat portion 61b having a circular shape when viewed from the direction of the axis L, and a curved portion 61c' that smoothly and continuously connects the cylindrical portion 61a and the flat portion 61b, has a convex shape toward the outer surface side, and has a ring shape when viewed from the direction of the axis L. The thickness t of the flat portion 61b, the curved portion 61c', and the cylindrical portion 61a of the case 61' is uniform. The curved portion 61c' is made up of two arcs (a first arc Ca1' and a second arc Ca2').

[0081] Specifically, when the case 61' is viewed from a vertical section, the flat portion 61b extends along a direction perpendicular to the axis L, as in the present embodiment, and is a parallel positioning means that is positioned parallel to the joint Cs (see FIG. 1), which is one end of the cylindrical portion 61a. The first arc Ca1' has a radius of curvature R1' and is a flat portion connecting arc that connects to the flat portion 61b in the first boundary region Br1. The second arc Ca2' has a radius of curvature R2' and is a cylindrical portion connecting arc that connects to the cylindrical portion 61a in the second boundary region Br2. In addition, the first arc Ca1' and the second arc Ca2' are connected to each other in the third boundary region Br3.

[0082] Here, in the first boundary region Br1, a tangent to the first arc Ca1' (flat surface portion connecting arc) extends in a direction along the flat surface portion 61b, and in the second boundary region Br2, a tangent to the second arc Ca2' (cylindrical portion connecting arc) extends in a direction along the cylindrical portion 61a. This allows the curved surface portion 61c' to be continuously and smoothly connected to the cylindrical portion 61a and the flat surface portion 61b. In addition, in the third boundary region Br3, the tangents to the first arc Ca1' and the second arc Ca2' extend in a direction along the same line. In this way, the curved surface portion 61c' consisting of two arcs is a curve that is continuously and smoothly connected.

[0083] The sum of the central angle θ1' of the first arc Ca1' (center O1', curvature radius R1') and the central angle θ2' of the second arc Ca2' (center O2', curvature radius R2') is 90°. A straight line connecting the first boundary region Br1 and the center O1' of the first arc Ca1' is parallel to the axis L passing through the center of the cylindrical portion 61a, and a straight line connecting the second boundary region Br2 and the center O2' of the second arc Ca2' is perpendicular to the axis L passing through the center of the cylindrical portion 61a. A distance a1 between the center O1' of the first arc Ca1' and the center O2' of the second arc Ca2' is equal to the difference between the curvature radius R1' of the first arc Ca1' and the curvature radius R2' of the second arc Ca2'.

[0084] In Case Variation Example 1 of the present embodiment, by disposing the center O1' of the first arc Ca1' (plane portion connection arc) on the one - end side from the second boundary region Br2 which is the other end of the cylindrical portion 61a, the length of the case 61' in the axial direction L can be made shorter by a reduction amount Rq2 compared to the length of the case 61 in the present embodiment.

[0085] Here, assuming the radius of curvature Rf of the plane portion connection arc and the radius of curvature Rt of the cylindrical portion connection arc, as shown in FIG. 6 respectively, they correspond to the radius of curvature R1' of the first arc Ca1' and the radius of curvature R2' of the second arc Ca2', and Rf (R1') > Rt (R2') is set. Here, in the curved surface portion 61c', by setting the relationship of 1 < Rf / Rt < 2, it is possible to prevent either the radius of curvature Rf of the plane portion connection arc or the radius of curvature Rt of the cylindrical portion connection arc from becoming extremely small compared to the other. Therefore, it is possible to suppress the occurrence of stress concentration at the other end (the first boundary region Br1) and the one - end (the second boundary region Br2) of the curved surface portion 61c'.

[0086] Note that in Case Variation Example 1 of the present embodiment, Rf (R1') > Rt (R2') and the relationship of 1 < Rf / Rt < 2 is set. However, it is not limited to this. For example, Rf (R1') < Rt (R2') may be set and 1 < Rt / Rf < 2 may be set. Similar to the above - mentioned relationship, the occurrence of stress concentration can be suppressed.

[0087] Also, assuming the diameter D1 of the plane portion 61b and the inner diameter D2 of the cylindrical portion 61a, as shown in FIG. 6, D2 = D1+2×(b1 + R2') (Equation 2) θ1'+θ2' = 90° (Equation 3) b1 = a1×sinθ1' (Equation 4) a1 = R1' - R2' (Equation 5), and Here, substituting Equation 4 and Equation 5 into Equation 2, D2 = D1+2×((R1' - R2')×sinθ1'+R2') (Equation 6) is satisfied. Using this (Equation 6), the size of the diameter D1 (=D2-2×((R1′-R2′)×sin θ1′+R2′)) of the flat portion 61b can be set appropriately.

[0088] In addition, in (Equation 6), when θ1'=30° and θ2=60°, D2 = D1 + R1' + R2' (= D1 + Rf + Rt) (Equation 7). Therefore, by using this (Equation 7), the diameter D1 (=D2-(R1'+R2')) of the flat portion 61b can be set by combining only three parameters, which not only makes it possible to smoothly design the case 61' but also makes it easy to manage the dimensions of the case 61'.

[0089] As described above, similar to the present embodiment, the case modification example 1 of the present embodiment simultaneously employs the parallel positioning means (flat surface portion 61b) and the pressing force buffering means (curved surface portion 61c') to simultaneously solve the conventional problem 1 (welding defects due to difficulty in parallel positioning) and the conventional problem 2 (large stress concentration caused by the pressing force during assembly), and can improve the pressure resistance performance of the case 61'. Further, since 1 < Rf / Rt < 2 in the case modification example 1 of the present embodiment, the occurrence of stress concentration at the other end (first boundary region Br1) and one end (second boundary region Br2) of the curved surface portion 61c' can be suppressed. Furthermore, the case modification example 1 of the present embodiment satisfies D2 = D1 + R1' + R2' (= D1 + Rf + Rt) (when θ1' = 30° and θ2 = 60°), similar to the present embodiment. Since the diameter D1 of the flat surface portion 61b can be set by only the combination of three parameters, the design of the case 61' can be smoothly carried out, and the dimensional management of the case 61' can be easily performed. In addition, similar to the present embodiment, the case modification example 1 of the present embodiment employs the case dimension error absorbing means (curved surface portion 61c') to eliminate the concern 1 (reduction in productivity due to detection of case dimension errors) and improve the productivity of the electric valve 100. Also, similar to the present embodiment, the case modification example 1 of the present embodiment employs the abnormal high-pressure buffering means (flat surface portion 61b and curved surface portion 61c') to eliminate the concern 2 (rupture of the flat surface portion due to abnormal high pressure) and prevent leakage to the outside. Furthermore, the case modification example 1 of the present embodiment, similar to the present embodiment, sets the upper limit value of the diameter D1 of the flat surface portion 61b to be 1 / 3 or less (D1 ≦ 1 / 3 × D2), preferably 1 / 4 or less (D1 ≦ 1 / 4 × D2), more preferably 1 / 5 or less (D1 ≦ 1 / 5 × D2) of the inner diameter D2 of the cylindrical portion 61a, so that the flat surface portion 61b can be reversibly changed. In addition, the case modification example 1 of the present embodiment arranges the center O1' of the first arc Ca1' (flat surface portion connection arc) on the one end side from the second boundary region Br2 which is the other end of the cylindrical portion 61a, so that the length of the case 61' in the axial direction L can be shortened by a reduction amount Rq2 compared to the length of the case 61 in the present embodiment.

[0090] (Case modification 2 of this embodiment) First, the configuration of the other end side of case 61'' in case modification 2 of this embodiment will be described with reference to FIG. 7. Case modification 2 of this embodiment differs from curved surface portion 61c of this embodiment in that curved surface portion 61c'' is made up of three arcs (first arc Ca1'', second arc Ca2'', and third arc Ca3''). However, the other basic configuration is the same as in this embodiment. Note that as shown in FIG. 7, case 61'' has a bilaterally symmetrical shape, so only the shape of the right half will be used to describe the case.

[0091] <Configuration of the other end of the case> As shown in FIG. 7, the case 61'' includes a cylindrical portion 61a extending in the direction of the axis L and having a cylindrical shape, a flat portion 61b having a circular shape when viewed from the direction of the axis L, and a curved portion 61c'' that continuously and smoothly connects the cylindrical portion 61a and the flat portion 61b, has a convex shape toward the outer surface, and has an annular shape when viewed from the direction of the axis L. The flat portion 61b, the curved portion 61c'' and the cylindrical portion 61a of the case 61'' have a uniform wall thickness t. The curved portion 61c'' is made up of three arcs (a first arc Ca1'', a second arc Ca2'', and a third arc Ca3'').

[0092] Specifically, when the case 61'' is viewed from a vertical section, the flat portion 61b extends in a direction perpendicular to the axis L, as in the present embodiment, and is a parallel positioning means that is positioned parallel to the joint Cs (see FIG. 1), which is one end of the cylindrical portion 61a. The first arc Ca1'' has a radius of curvature R1'', and is a flat portion connecting arc that connects to the flat portion 61b in a first boundary region Br1. The second arc Ca2'' has a radius of curvature R2'', and is a cylindrical portion connecting arc that connects to the cylindrical portion 61a in a second boundary region Br2. In addition, the third arc Ca3'' has a radius of curvature R3'', and is connected to the first arc Ca1'' in a third boundary region Br3 and is connected to the second arc Ca2'' in a fourth boundary region Br4.

[0093] Here, in the first boundary region Br1, a tangent to the first arc Ca1'' (flat portion connecting arc) extends in a direction along the flat portion 61b, and in the second boundary region Br2, a tangent to the second arc Ca2'' (cylindrical portion connecting arc) extends in a direction along the cylindrical portion 61a. This allows the curved surface portion 61c'' to be continuously and smoothly connected to the cylindrical portion 61a and the flat surface portion 61b. In addition, in the third boundary region Br3, tangents to the first arc Ca1'' and the third arc Ca3'' extend in a direction along the same line, and in the fourth boundary region Br4, tangents to the second arc Ca2'' and the third arc Ca3'' extend in a direction along the same line. In this way, the curved surface portion 61c'' consisting of three arcs is a curve that is continuously and smoothly connected.

[0094] The sum of the central angle θ1'' formed by the first arc Ca1'' (center O1'', radius of curvature R1''), the central angle θ2'' formed by the second arc Ca2'' (center O2'', radius of curvature R2''), and the central angle θ3'' formed by the third arc Ca3'' (center O3'', radius of curvature R3'') is 90°. A straight line connecting the first boundary region Br1 and the center O1'' of the first arc Ca1'' is parallel to the axis L passing through the center of the cylindrical portion 61a, and a straight line connecting the second boundary region Br2 and the center O2'' of the second arc Ca2'' is perpendicular to the axis L passing through the center of the cylindrical portion 61a. Furthermore, a distance a1'' between the center O1'' of the first arc Ca1'' and the center O3'' of the third arc Ca3'' is equal to the difference between the radius of curvature R1'' of the first arc Ca1'' and the radius of curvature R3'' of the third arc Ca3''. In addition, a distance a3 between the center O3'' of the third arc Ca3'' and the center O2'' of the second arc Ca2'' is equal to the difference between the radius of curvature R3'' of the third arc Ca3'' and the radius of curvature R2'' of the second arc Ca2''.

[0095] In case modification example 2 of the present embodiment, by arranging the center O1’’ of the first arc Ca1’’ (plane part connection arc) on the one end side from the second boundary region Br2 which is the other end part of the cylindrical part 61a, the length of the case 61’’ in the axial direction L can be made shorter by the reduction amount Rq3 compared with the length of the case 61 in the present embodiment.

[0096] Here, assuming the radius of curvature Rf of the plane part connection arc and the radius of curvature Rt of the cylindrical part connection arc, as shown in FIG. 7 respectively, they correspond to the radius of curvature R1’’ of the first arc Ca1’’ and the radius of curvature R2’’ of the second arc Ca2’’, and Rf (R1’’) > Rt (R2’’) is set. Here, by setting the relationship of 1 < Rf / Rt < 2, it is possible to prevent either one of the radius of curvature Rf of the plane part connection arc and the radius of curvature Rt of the cylindrical part connection arc from having an extremely small radius of curvature compared with the other, so that the occurrence of stress concentration at the other end part (the first boundary region Br1) and the one end part (the second boundary region Br2) of the curved surface part 61c’’ can be suppressed.

[0097] Note that in case modification example 2 of the present embodiment, Rf (R1’’) > Rt (R2’’) and the relationship of 1 < Rf / Rt < 2 is set, but it is not limited to this. For example, Rf (R1’’) < Rt (R2’’) may be set and 1 < Rt / Rf < 2 may be set. Similar to the above relationship, the occurrence of stress concentration can be suppressed.

[0098] Also, assuming the diameter D1 of the plane part 61b and the inner diameter D2 of the cylindrical part 61a, as shown in FIG. 7, D2 = D1 + 2×(b1’’ + b3 + R2’’) (Equation 8) θ1’’ + θ2’’ + θ3’’ = 90° (Equation 9) b1’’ = a1’’×sinθ1’’ (Equation 10) a1’’ = R1’’ - R3’’ (Equation 11) b3 = a3×cosθ2’’ (Equation 12) a3 = R3’’ - R2’’ (Equation 13), and Here, substituting (Equations 10) to (13) into (Equation 8), D2=D1+2×((R1''-R3'')×sinθ1''+(R3''-R2'')×cosθ2''+R2'') (Equation 14) It will satisfy the following. Using this (Equation 14), the size of the diameter D1 (=D2-2×((R1″-R3″)×sin θ1″+(R3″-R2″)×cos θ2″+R2″)) of the flat portion 61b can be set appropriately.

[0099] As described above, similar to the present embodiment, the case modification example 2 of the present embodiment simultaneously employs the parallel positioning means (flat surface portion 61b) and the pressing force buffering means (curved surface portion 61c''), thereby simultaneously solving the conventional problem 1 (welding defects due to difficulty in parallel positioning) and the conventional problem 2 (large stress concentration caused by the pressing force during assembly), and improving the pressure resistance performance of the case 61''. In addition, similar to the case modification example 1 of the present embodiment, since 1 < Rf / Rt < 2 in the case modification example 2 of the present embodiment, the occurrence of stress concentration at the other end (first boundary region Br1) and one end (second boundary region Br2) of the curved surface portion 61c'' can be suppressed. Furthermore, similar to the present embodiment, the case modification example 2 of the present embodiment employs the case dimension error absorbing means (curved surface portion 61c''), thereby eliminating the concern 1 (reduction in productivity due to detection of case dimension errors) and improving the productivity of the electric valve 100. Additionally, similar to the present embodiment, the case modification example 2 of the present embodiment employs the abnormal high-pressure buffering means (flat surface portion 61b and curved surface portion 61c''), thereby eliminating the concern 2 (rupture of the flat surface portion due to abnormal high pressure) and preventing leakage to the outside. Also, similar to the present embodiment, the case modification example 2 of the present embodiment sets the upper limit value of the diameter D1 of the flat surface portion 61b to be 1 / 3 or less (D1 ≦ 1 / 3 × D2), preferably 1 / 4 or less (D1 ≦ 1 / 4 × D2), and more preferably 1 / 5 or less (D1 ≦ 1 / 5 × D2) of the inner diameter D2 of the cylindrical portion 61a, so that the flat surface portion 61b can be reversibly changed. Furthermore, similar to the case modification example 1 of the present embodiment, the case modification example 2 of the present embodiment arranges the center O1'' of the first arc Ca1'' (arc connecting the flat surface portion) on the one end side from the second boundary region Br2 which is the other end of the cylindrical portion 61a, so that the length of the case 61'' in the axial direction L can be shortened by a reduction amount Rq3 (< Rq2) compared to the length of the case 61 in the present embodiment.

[0100] Note that the curved surface portions 61c, 61c', 61c'' in the present embodiment (including the case modification examples 1 and 2) are composed of one to three arcs, but are not limited thereto. For example, as long as it is a curved surface portion that is continuously and smoothly connected, it may include those composed of four or more arcs.

[0101] <About the refrigeration cycle system> The refrigeration cycle system of the present invention will be described with reference to Fig. 8. The refrigeration cycle system includes an expansion valve 100 using the motor-operated valve 100 of this embodiment (including case modifications 1 and 2), an outdoor heat exchanger 200 mounted on an outdoor unit, an indoor heat exchanger 300 mounted on an indoor unit, a flow path switching valve 400 constituting a four-way valve, and a compressor 500. Here, the expansion valve 100, the outdoor heat exchanger 200, the indoor heat exchanger 300, the flow path switching valve 400, and the compressor 500 are each connected by a conduit to constitute a heat pump type refrigeration cycle. Note that an accumulator, a pressure sensor, a temperature sensor, etc. are not shown.

[0102] The flow path of the refrigeration cycle is switched between two flow paths, one for cooling operation and the other for heating operation, by the flow path switching valve 400. During cooling operation (see the solid arrow in the figure), the refrigerant compressed by the compressor 500 flows from the flow path switching valve 400 into the outdoor heat exchanger 200, which functions as a condenser, and the liquid refrigerant flowing out of the outdoor heat exchanger 200 flows through the expansion valve 100 into the indoor heat exchanger 300, which functions as an evaporator.

[0103] On the other hand, during heating operation (see the dashed arrow in the figure), the refrigerant compressed by the compressor 500 is circulated from the flow path switching valve 400 to the indoor heat exchanger 300, the expansion valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and then to the compressor 500, with the indoor heat exchanger 300 functioning as a condenser and the outdoor heat exchanger 200 functioning as an evaporator. Thus, the expansion valve 100 decompresses and expands the liquid refrigerant flowing in from the outdoor heat exchanger 200 during cooling operation, or the liquid refrigerant flowing in from the indoor heat exchanger 300 during heating operation, and can further control the flow rate of the refrigerant.

[0104] The present invention is not limited to this embodiment (including case modifications 1 and 2), but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. The motor-operated valve 100 of this embodiment (including case modifications 1 and 2) is used not only in refrigeration cycle systems but also in air conditioners such as home air conditioners. However, the motor-operated valve of the present invention is not limited to home air conditioners, but may be commercial air conditioners, and is not limited to air conditioners, but may be applied to water heaters and various types of refrigerators. In this embodiment (including case modifications 1 and 2), a case having a flat surface, a curved surface, and a cylindrical portion is applied to the motor-operated valve 100 as a case that houses a drive unit (such as a drive member that generates a rotational motion), but is not limited thereto. For example, a case having a flat surface, a curved surface, and a cylindrical portion may be applied to a solenoid valve as a plunger tube that houses a drive unit (such as a drive member that generates a linear reciprocating motion).

[0105] <Other> Needless to say, the motor-operated valve 100 of this embodiment (including case modifications 1 and 2) is applicable not only to the refrigeration cycle illustrated, but also to any fluid device and fluid circuit. Furthermore, the present invention is not limited to the above-mentioned aspects, embodiments, and modifications, and can be modified as appropriate without departing from the technical concept of the present invention. [Explanation of symbols]

[0106] 100 Motor-operated valve 1 First joint pipe 2. Second joint pipe 10 Valve body 11 Valve seat member 11a Valve port 12 Valve chamber 20 Support member 21 Holder part 22 Fixed part 23 Screw hole 23a Female thread 24 Bearing hole 25 Slide hole 26 Guide rail 30 Drive shaft 31 Threaded part 31a Male thread 32 Guide section 33 Flange section 40 Valve body 41 Valve holder 41a Lower end 41b Upper end 42 Valve body 43 Washer 44 Spring support 45 Compression coil spring 50 Coil material 51 Coil section 52 Claw part 60 Stepping motor (drive unit) 61,61',61'' Case 61a Cylindrical part 61b Plane part 61ba Outer surface of flat part 61bb Inner surface of flat surface 61bc Other end side curved part 61c,61c',61c'' curved part 62 Magnet rotor (driving member) 64 Magnet section 65 Disc Section 66 Metal fittings 67 protrusion a1,a1'' Distance between the center of the first arc and the center of the second arc a3 Distance between the center of the third arc and the center of the second arc Br1 First border region Br2 Second boundary region Br3 Third boundary region Br4 The fourth boundary region Ca1 First arc (arc connecting plane section, arc connecting cylindrical section) Ca1', Ca1'' First arc (plane section connecting arc) Ca2', Ca2'' Second arc (cylinder section connecting arc) Ca3'' Third Arc Cl holding fixture Cs junction D1 Diameter of the flat part D2 Inner diameter of cylindrical part F1 Pressing force F2 Repulsion L axis L0 Actual case length (= L1 + L2) L1 Actual cylindrical length L2 Actual length of curved surface L2' Length of curved part when pressed Ld Case length when pressed (=L1+L2') Lmin Minimum allowable dimension M1 Pressing direction M2 Separation direction O1,O1',O1'' Center of the first arc O2',O2'' Center of the second arc O3'' Center of the third arc Pabn Abnormally High Pressure Pnl Normal operating pressure Pt holding fixture Pv Push-in amount R1 Radius of curvature of the first arc R1,R1',R1'' Radius of curvature of the first arc R2',R2'' Radius of curvature of the second arc R3'' Radius of curvature of the third arc Rf Radius of curvature of the connecting arc of the flat surface Rq2, Rq3 Axial reduction in case length Rt Radius of curvature of cylindrical section connecting arc t Thickness W Welding θ1,θ1',θ1'' Central angle of the first arc θ2',θ2'' The central angle of the second arc θ3'' The central angle of the third arc

Claims

1. a valve body having a valve port; a valve body for controlling an opening area of ​​the valve port; A drive unit that moves the valve body forward and backward; A parallel positioning means; A pressing force buffering means; A motor-operated valve comprising: The drive unit includes a drive member and a case that houses the drive member and is connected to and integrally formed with the valve body, the case includes a planar portion having a circular shape when viewed from the axial direction, a cylindrical portion extending in the axial direction and having a cylindrical shape, and a curved portion continuously connecting the planar portion and the cylindrical portion and having an annular shape when viewed from the axial direction, When the case is viewed from a vertical cross section, the curved surface portion has a flat surface portion connecting arc that is connected to the flat surface portion in a first boundary region and has a predetermined radius of curvature, and a cylindrical surface portion connecting arc that is connected to the cylindrical surface portion in a second boundary region and has a predetermined radius of curvature, a tangent to the plane portion connecting arc in the first boundary region extends in a direction along the plane portion; a tangent to the cylindrical portion connecting arc in the second boundary region extends in a direction along the cylindrical portion; the parallel positioning means is the flat portion that positions one end of the case and the other end of the valve body parallel to each other, The pressure-absorbing means is the curved portion consisting of one or more arcs when viewed from a longitudinal section of the case, and when an axial pressure is applied to the outer surface of the flat portion, the curved portion bends to absorb the pressure.

2. 2. The motor-operated valve according to claim 1, wherein the radii of curvature of the flat portion connecting arc and the cylindrical portion connecting arc are set to satisfy the relationship 1≦Rf / Rt<2, where Rf and Rt are the radii of curvature of the flat portion connecting arc and the cylindrical portion connecting arc, respectively.

3. 2. The motor-operated valve according to claim 1, wherein the radii of curvature of the flat portion connecting arc and the cylindrical portion connecting arc are Rf and Rt, respectively, the inner diameter of the cylindrical portion is D2, and the diameter of the flat portion is D1, and the relationship D2 = Rf + Rt + D1 is satisfied.

4. When the case is viewed from a vertical cross section, The curved surface portion is made up of two or more circular arcs, 2. The motor-operated valve according to claim 1, wherein a center of the flat portion connecting arc is located on one end side of the other end of the cylindrical portion.

5. Further comprising a case dimensional error absorbing means, The case is integrally formed by pressing, The motor-operated valve according to claim 1, characterized in that the case dimensional error absorbing means is the curved portion, and when the pressing force is applied to the outer surface of the flat portion, the curved portion is deflected, thereby moving only the flat portion in the axial direction, thereby absorbing the dimensional error of the case.

6. Further comprising an abnormally high pressure buffer means, the case is integrally formed by pressing, and the thicknesses of the planar portion, the curved portion, and the cylindrical portion at least in the vicinity of the second boundary region are uniform, 2. The motor-operated valve according to claim 1, wherein the abnormally high pressure buffer means is the flat surface portion and the curved surface portion, and when an abnormally high pressure in the axial direction is applied to the inner surface of the flat surface portion, the flat surface portion and the curved surface portion are smoothly deflected so as to be continuously connected to the cylindrical portion, and are deformed into a substantially hemispherical shape, thereby buffering the load due to the abnormally high pressure.

7. 7. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to claim 1 is used as the expansion valve.

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