Electric valve and refrigeration cycle system using same

Abstract

The purpose of the present invention is to provide an electrically operated valve capable of improving the pressure resistance of a housing by examining the structure of the other end side of the housing, and a refrigeration cycle system using the same. In an electrically operated valve (100), a housing (61) is provided with a flat surface portion (61b), a cylindrical portion (61a), and a curved surface portion (61c), a tangent line of a flat surface portion connection arc in a first boundary region (Br1) extends in a direction along the flat surface portion (61b), and a tangent line of a cylindrical portion connection arc in a second boundary region (Br2) extends in a direction along the cylindrical portion (61a). The parallel positioning mechanism is a flat surface portion (61b) which positions one end portion of the housing (61) and the other end portion of the valve body (10) in parallel, and the pressing force buffer mechanism is a curved surface portion (61c) which is composed of more than one circular arc when the housing (61) is observed from a longitudinal cross section. When a pressing force (F1) in the direction of the axis (L) is applied to the outer surface (61ba) of the flat surface portion (61b), the pressing force (F1) is buffered by bending the curved surface portion (61c).

Description

Technical Field

[0001] The present invention relates to an electric valve having a parallel positioning mechanism and a pressing force buffer mechanism and a refrigeration cycle system using the electric valve. Background Art

[0002] like Fig. 9 As shown, patent document 1 records an electric valve 900 (hereinafter referred to as "the previous electric valve"), which includes a valve body 910 and a shell 961 welded and fixed to the valve body 910, the shell 961 having: a cylindrical portion 961a, which extends along the axis L direction; and a circular plate portion 961d, which has a circular shape when viewed from the axis L direction and is fixed to one end of the cylindrical portion 961a via a welding portion W1.

[0003] Here, although it is not clearly stated in Patent Document 1, it can be imagined that, for example, when assembling the shell 961 to the valve body 910, a pressing clamp (not shown) is used to apply pressing force in the direction of the axis L to the circular plate portion 961d, while docking the shell 961 and the valve body 910, and fixing them to each other via the welding portion W2.

[0004] However, since the circular plate portion 961d is fixed to the housing 961 via the welding portion W1, the horizontality of the circular plate portion 961d is low. Due to the low horizontality of the circular plate portion 961d, when the circular plate portion 961d is pressed toward the other end side in the direction of the axis L by the pressing fixture, the housing 961 is tilted relative to the axis L, making it impossible to position one end of the housing 961 and the other end of the valve body 910 parallel to each other, resulting in a gap, and thus poor welding in the welding portion W2 may occur (hereinafter referred to as "conventional problem 1 (poor welding caused by difficulty in parallel positioning").

[0005] In addition, considering that the shell 961 itself or the air inside the shell 961 expands due to the welding heat generated in the welding portion W2, it is necessary to set the pressing force on the circular plate portion 961d along the axis L to be larger to suppress the misalignment of the shell 961 relative to the valve body 910.

[0006] Therefore, when the shell 961 is assembled to the valve body 910, a large pressing force is applied to the circular plate portion 961d on one end side in the direction of the axis L, and a great stress concentration occurs in the weld portion W1 which is the connection between the circular plate portion 961d and the cylindrical portion 961a, which may reduce the strength of the weld portion W1 (hereinafter referred to as "previous problem 2 (large stress concentration caused by the pressing force during assembly)").

[0007] As a result, in the existing electric valve, due to previous problem 1 (poor welding due to difficulty in parallel positioning) and previous problem 2 (large stress concentration caused by pressing force during assembly), the strength of the welding portion W2 between the shell 961 and the valve body 910, and the welding portion W1 between the circular plate portion 961d and the cylindrical portion 961a are respectively reduced. In the worst case, the shell 961 may rupture under normal use pressure.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Chinese Patent Application Publication No. 108626413 Summary of the invention

[0011] Technical issues

[0012] An object of the present invention is to provide an electric valve and a refrigeration cycle system using the same, which can solve the conventional problems 1 and 2 at the same time and improve the pressure resistance of the shell by considering the structure of the other end side of the shell.

[0013] Technical Solution

[0014] In order to solve the above-mentioned problems, an electric valve is provided, which comprises: a valve body, which has a valve port; a valve body, which controls the opening area of ​​the valve port; a driving part, which makes the valve body move forward and backward; a parallel positioning mechanism; and a pressing force buffer mechanism, wherein the driving part comprises a driving component and a shell, wherein the shell accommodates the driving component and is connected to the valve body and is integrally formed, and the shell comprises: a planar part, which has a circular shape when viewed from the axial direction; a cylindrical part, which extends along the axial direction and has a cylindrical shape; and a curved part, which continuously connects the planar part and the cylindrical part and has a circular ring shape when viewed from the axial direction, and when the shell is viewed from a longitudinal section, the curved part comprises: a planar part connecting an arc, which intersects with the cylindrical part in a first boundary area. The planar portion is connected and has a predetermined curvature radius; and the cylindrical portion is connected to the cylindrical portion in a second boundary area and has a predetermined curvature radius, the tangent of the planar portion connecting arc in the first boundary area extends in a direction along the planar portion, and the tangent of the cylindrical portion connecting arc in the second boundary area extends in a direction along the cylindrical portion, the parallel positioning mechanism is the planar portion that positions one end of the shell and the other end of the valve body parallel to each other, and the pressing force buffering mechanism is the curved portion portion composed of more than one arc when the shell is observed from a longitudinal section, and when a pressing force in the axial direction is applied to the outer surface of the planar portion, the pressing force is buffered by the bending of the curved portion.

[0015] In addition, in the above-mentioned electric valve, the curvature radii of the planar portion connecting arc and the cylindrical portion connecting arc may be respectively Rf and Rt, and then the relationship of 1≤Rf / Rt<2 may be set.

[0016] In addition, in the above-mentioned electric valve, the curvature radii of the connecting arc of the planar portion and the connecting arc of the cylindrical portion may be Rf and Rt respectively, the inner diameter of the cylindrical portion may be D2, and the diameter of the planar portion may be D1, and then the relationship D2=Rf+Rt+D1 may be set.

[0017] In the above-mentioned electric valve, when the housing is viewed in a longitudinal section, the curved surface portion may be composed of two or more arcs, and the center of the planar portion connecting the arcs may be arranged closer to one end than the other end of the cylindrical portion.

[0018] In addition, in the above-mentioned electric valve, it may be that there is also a shell size error absorption mechanism, the shell is integrally formed by stamping, and the shell size error absorption mechanism is the curved surface portion. When the pressing force is applied to the outer surface of the planar portion, the curved surface portion is bent to move only the planar portion along the axial direction to absorb the size error of the shell.

[0019] In addition, in the above-mentioned electric valve, it may be that it is also provided with an abnormally high pressure buffer mechanism, the shell is integrally formed by stamping, and the wall thickness of each of the planar portion, the curved portion, and the cylindrical portion near at least the second boundary area is uniform, and the abnormally high pressure buffer mechanism is the planar portion and the curved portion. 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 bent in a manner continuously connected to the cylindrical portion and deformed into a roughly hemispherical shape to buffer the load caused by the abnormally high pressure.

[0020] In addition, a refrigeration cycle system includes a compressor, a condenser, an expansion valve, and an evaporator, and the electric valve can be used as the expansion valve.

[0021] Effects of the Invention

[0022] According to the present invention, it is possible to provide an electric valve and a refrigeration cycle system using the same that can solve conventional problems 1 and 2 at the same time and improve the pressure resistance of the shell by considering the structure of the other end side of the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is a longitudinal sectional view showing the electric valve according to the present embodiment of the present invention.

[0024] Figure 2 Only shows Figure 1An enlarged view of the other end of the shell.

[0025] Figure 3 It is an explanatory diagram showing an assembly process of the electric valve in this embodiment.

[0026] Figure 4 It is shown Figure 3 An illustration of the deformation state of the shell in FIG.

[0027] Figure 5 It is an explanatory diagram showing a deformation state of a housing due to a change in the internal pressure of the electric valve in the present embodiment.

[0028] Figure 6 is an enlarged view showing the other end of the housing in the housing modification 1 of the present embodiment (corresponding to Figure 2 ).

[0029] Figure 7 is an enlarged view showing the other end of the housing in the housing modification 2 of the present embodiment (corresponding to Figure 2 ).

[0030] Figure 8 It is a diagram showing the refrigeration cycle system of the present invention.

[0031] Fig. 9 1 is a longitudinal sectional view showing a conventional electric valve.

[0032] Reference numerals

[0033] 100: electric valve, 1: first joint pipe, 2: second joint pipe, 10: valve body, 11: valve seat component, 11a: valve port, 12: valve chamber, 20: support component, 21: holding portion, 22: fixing portion, 23 threaded hole, 23a: internal threaded portion, 24: bearing hole, 25: sliding hole, 26: guide rail, 30: drive shaft, 31: threaded portion, 31a: external threaded portion, 32: guide portion, 33: flange portion, 40: valve body portion, 41: valve seat, 41a: lower end portion, 41b: upper end portion, 42: valve body, 43: washer, 44: spring seat, 45: compression coil spring, 50: coil component, 51: coil portion, 52: claw portion, 60: stepping motor (drive portion), 61, 61' , 61”: housing, 61a: cylindrical portion, 61b: plane portion, 61ba: outer surface of the plane portion, 61bb: inner surface of the plane portion, 61bc: curved portion on the other end side, 61c, 61c', 61c”: curved portion, 62: magnetic rotor (driving component), 64: magnet portion, 65: disk portion, 66: metal parts, 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 boundary region, Br2: second boundary region, Br3: third boundary region, Br4: fourth boundary region, Ca1: first arc (plane portion connecting arc, cylindrical portion connecting arc), Ca1' , Ca1”: first arc (arc connecting the planar portion), Ca2', Ca2”: second arc (arc connecting the cylindrical portion), Ca3”: third arc, Cl: holding fixture, Cs: joint portion, D1: diameter of the planar portion, D2: inner diameter of the cylindrical portion, F1: pressing force, F2: repulsive force, L: axis, L0: actual size shell length (= L1 + L2), L1: actual size cylinder length, L2: actual size curved portion length, L2': curved portion length when pressed, Ld: shell length when pressed (= L1 + L2'), Lmin: minimum allowable size, M1: pressing direction, M2: spacing 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: Normally used pressure, Pt: Pressing fixture, Pv: Pressing amount, R1: Curvature radius of the first arc, R1, R1', R1”: Curvature radius of the first arc, R2', R2”: Curvature radius of the second arc, R3”: Curvature radius of the third arc, Rf: Curvature radius of the plane connecting arc, Rq2, Rq3: Length reduction of the shell in the axial direction, Rt: Curvature radius of the cylindrical connecting arc, t: Wall thickness, W: Welding part, θ1, θ1', θ1”: Center angle formed by the first arc, θ2', θ2”: Center angle formed by the second arc, θ3”: Center angle formed by the third arc. DETAILED DESCRIPTION

[0034] Reference Figures 1 to 8 The embodiments of the present invention are described in detail. However, the present invention is not limited to the embodiments.

[0035] <About Terminology>

[0036] In the description of this specification and claims, "left", "right", "upper" and "lower" mean Figures 1 to 7 In the direction shown in the description of the present specification and claims, "one end" and "the other end" refer to the "lower end" and "upper end" in the figure. In the description of the present specification and claims, "longitudinal section" means "the plane of the cut obtained when the object is cut along the axial direction". In the description of the present specification and claims, "normal operating pressure" means "the pressure used in the electric valve during normal operation". In the description of the present specification and claims, "maximum operating pressure" means "normal operating pressure plus a predetermined margin pressure, which is the maximum pressure at which the electric valve functions without hindrance under normal conditions of use". In the description of the present specification and claims, "withstand pressure" means "maximum operating pressure plus a predetermined margin pressure, which is the maximum pressure that can prevent leakage to the outside although it cannot guarantee that the electric valve functions without hindrance". In the description of the present specification and claims, "abnormally high pressure" means "high pressure that deviates from the maximum operating pressure below the withstand pressure (maximum operating pressure < abnormally high pressure ≤ withstand pressure)". In the description of this specification and claims, "dimensional tolerance" means "the difference between the maximum allowable dimension and the minimum allowable dimension within the allowable range". In the description of this specification and claims, "minimum allowable dimension" means "the minimum dimension that is allowable as an actual dimension". In the description of this specification and claims, "planar portion connecting arc" means "an arc connected to the planar portion and having a predetermined radius of curvature". In the description of this specification and claims, "cylindrical portion connecting arc" means "an arc connected to the cylindrical portion and having a predetermined radius of curvature".

[0037] (Present Embodiment)

[0038] <About the structure of the electric valve>

[0039] Will use Figure 1 The electric valve 100 according to the embodiment of the present invention is described. The electric valve 100 is mainly composed of a valve body 10, a support member 20, a drive shaft 30, a valve body 40, a coil member 50, and a stepping motor 60 (drive unit). The components of the electric valve 100 are described in sequence.

[0040] Here, the details will be described later, but in the electric valve 100 of this embodiment, by adopting the housing 61 (refer to Figure 1 ) and the valve body 10 (see Figure 1 ) and a parallel positioning mechanism for positioning the other end (upper end) of the axial direction parallel to each other, and a buffer pressing force F1 (refer to Figure 3 ) is provided to solve the previous problem 1 (poor welding due to difficulty in parallel positioning) and the previous problem 2 (large stress concentration caused by the pressing force during assembly) as the aforementioned subject, and to improve the pressure resistance. Furthermore, in the electric valve 100 of this embodiment, the concerns associated with the use of the parallel positioning mechanism and the pressing force buffer mechanism (concern 1 (reduced productivity due to dimensional error detection of the shell) or concern 2 (rupture of the flat portion due to abnormally high pressure)) are considered. In order to solve the concerns, a shell dimensional error absorption mechanism, an abnormally high pressure buffer mechanism, etc. are used.

[0041] The valve body 10 is formed into a cylindrical shape using a metal such as stainless steel as a material. The valve body 10 is provided with a valve seat member 11 formed separately from the valve body 10 so as to block the lower end. A valve port 11a is opened at the center of the valve seat member 11. The valve body 10 forms a valve chamber 12 inside.

[0042] In the valve body 10, a first joint pipe 1 as a flow path of a fluid such as a refrigerant is connected to the outer peripheral sheet side, and the first joint pipe 1 is connected to the valve chamber 12. In addition, a second joint pipe 2 abutting against the valve seat member 11 is connected to the bottom surface side of the valve body 10, and the second joint pipe 2 is connected to the valve chamber 12 via the valve port 11a. The first joint pipe 1 and the second joint 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.

[0043] The support member 20 includes a substantially cylindrical holding portion 21 made of a resin material such as polyphenylene sulfide (PPS), and a stainless steel fixing portion 22 integrally provided by insert molding at the other end of the holding portion 21. The support member 20 is fixed to the valve body 10 by welding at the fixing portion 22.

[0044] The retaining portion 21 is configured so that its axis overlaps with the axis L of the shaft passing through the valve port 11a. The threaded hole 23, the bearing hole 24, and the sliding hole 25 arranged along the axis L in a manner penetrating the retaining portion 21 are formed on concentric circles at the center of the retaining portion 21. An internal threaded portion 23a is formed on the inner circumferential surface of the threaded hole 23, and an external threaded portion 31a of the drive shaft 30 described later is screwed. The guide portion 32 of the drive shaft 30 described later is slidably engaged with the inner circumferential surface of the bearing hole 24. The sliding hole 25 is configured close to the valve port 11a, and is formed to have a larger diameter than the bearing hole 24. The valve body portion 40 described later is slidably engaged with the sliding hole 25.

[0045] The guide rail 26 composed of spiral protrusions is integrally formed on the outer peripheral surface of the holding portion 21. In the guide rail 26, the winding return portions adjacent to each other are arranged at intervals. The guide rail 26 is arranged so that its axis overlaps with the axis L, and the coil portion 51 of the coil component 50 described later is screwed, and each winding portion of the coil portion 51 is guided from one side or both sides so that the coil component 50 can rotate in the circumferential direction.

[0046] The drive shaft 30 is formed into a cylindrical rod shape using a metal such as stainless steel as a material. The drive shaft 30 includes a threaded portion 31 arranged along the axis L, a guide portion 32, and a flange portion 33 arranged at the end of the valve port 11a close to the guide portion 32. An external threaded portion 31a is formed in the threaded portion 31, and the rotational motion of the drive shaft 30 is converted into a linear motion by screwing the external threaded portion 31a into the internal threaded portion 23a of the retaining portion 21. The guide portion 32 guides the movement of the drive shaft 30 along the axis L by slidably engaging with the inner circumferential surface of the bearing hole 24. The flange portion 33 rotatably locks the valve body portion 40 described later. In the present embodiment, the internal threaded portion 23a and the external threaded portion 31a are right-handed threads.

[0047] The valve body portion 40 includes a valve seat 41 , a valve body 42 , a gasket 43 , a spring seat 44 , and a compression coil spring 45 .

[0048] The valve seat 41 is formed in a cylindrical shape having an outer diameter substantially the same as the inner diameter of the sliding hole 25 of the holding portion 21. The valve seat 41 is engaged along the sliding hole 25 so as to be slidable in the axis L direction.

[0049] The valve body 42 is needle-shaped, and the tip of the needle is fixed to the lower end 41a on the valve port 11a side of the valve seat 41 in a manner facing the valve port 11a. The valve body 42 adjusts the opening of the valve seat with respect to the valve port 11a between the maximum opening of the valve and the minimum opening of the valve (or the fully closed state), and adjusts the flow rate by controlling the opening area of ​​the valve port 11a.

[0050] The flange portion 33 of the drive shaft 30 is rotatably engaged with the upper end portion 41b of the valve seat 41 on the opposite side to the valve port 11a. Specifically, the flange portion 33 of the drive shaft 30 sandwiches a gasket 43 between the upper end portion 41b of the valve seat 41, and the drive shaft 30 rotatably hooks the upper end portion 41b of the valve seat 41 through the flange portion 33. Through this engagement, the valve seat 41 is supported by the drive shaft 30 so as to be movable in the direction of the axis L and rotatable around the axis L. In addition, an opening portion larger than the movable range in the radial direction of the drive shaft 30 is formed in the upper end portion 41b of the valve seat 41. In addition, the spring seat 44 is movably arranged in the valve seat 41 in the direction of the axis L. The compression coil spring 45 is installed between the spring seat 44 and the valve body 42 in a compressed state with a predetermined load applied thereto. As a result, the spring seat 44 is urged toward the other end side and abuts against one end portion of the drive shaft 30.

[0051] The coil component 50 integrally includes a coil portion 51 in the shape of a spiral spring, and a claw portion 52 protruding radially outward from one end of the coil portion 51. The coil portion 51 is rotatably screwed to the circumference of the guide rail 26 of the retaining portion 21. The claw portion 52 can abut against a protrusion 67 of a magnetic rotor 62 described later, and the coil component 50 is pressed and rotated in the circumferential direction via the claw portion 52 through the rotation of the magnetic rotor 62. As a result, the coil component 50 abuts against an upper limit stopper (not shown) or a lower limit stopper (not shown), and while the rotation of the coil component 50 is restricted, the rotation of the magnetic rotor 62 is also restricted. Therefore, the valve body portion 40 is restricted from moving beyond the position of the maximum opening or the position of the minimum opening (or, the valve closed state). The coil component 50 can be easily manufactured by forming a metal wire such as stainless steel.

[0052] The stepping motor 60 includes a housing 61 , a magnetic rotor 62 (driving member), and a stator coil (not shown).

[0053] The housing 61 is integrally formed of a metal such as stainless steel, has a substantially cylindrical shape with a bottom at the other end and an opening at one end, and accommodates the magnetic rotor 62. The joint Cs at one end of the housing 61 and the upper end of the valve body 10 are fixed airtightly by a welding portion W.

[0054] The details will be described later, but in this embodiment, by considering the structure of the other end side of the housing 61, it is possible to solve the conventional problems 1 and 2 at the same time and improve the pressure resistance performance.

[0055] The magnetic rotor 62 is integrally provided with a cylindrical magnet portion 64 whose outer circumference is magnetized to multiple poles, and a disc portion 65 that closes one end thereof. The magnetic rotor 62 is fixed to the drive shaft 30 via a metal fitting 66 integrally formed at the center of the disc portion 65. Thus, the magnetic rotor 62 is rotatably provided in the housing 61 around the axis L of the drive shaft 30. The drive shaft 30 is a rotation axis of the magnetic rotor 62.

[0056] The stator coil is disposed on the outer peripheral surface of the housing 61 , and a pulse signal is applied to the stator coil, so that the magnetic rotor 62 rotates according to the number of pulses. The stator coil corresponds to the stepping motor 60 .

[0057] When the magnetic rotor 62 rotates, the drive shaft 30 rotates together with the magnetic rotor 62, and the drive shaft 30 moves along the axis L direction through the thread feeding action of the external thread portion 31a and the internal thread portion 23a, so that the valve body portion 40 moves forward and backward relative to the valve port 11a. As a result, the opening of the valve seat with respect to the valve port 11a is changed, and 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) is controlled.

[0058] <Structure of the other end side of the housing>

[0059] Here, we will use Figure 2 The structure of the other end side of the housing 61 will be described. Figure 2 As shown, the shell 61 is bilaterally symmetrical, so only the shape of the right half is used for explanation. The shell 61 includes: a cylindrical portion 61a, which extends along the axis L direction and has a cylindrical shape; a flat portion 61b, which has a circular shape when viewed from the axis L direction; and a curved portion 61c, which continuously and smoothly connects the cylindrical portion 61a and the flat portion 61b, is convex toward the outside, and has a circular ring shape when viewed from the axis L direction. The wall thickness t of the flat portion 61b, the curved portion 61c, and the cylindrical portion 61a in the shell 61 is uniform. The curved portion 61c in this embodiment is composed of a circular arc (first circular arc Ca1).

[0060] Specifically, Figure 2 As shown in FIG. 1 , when the housing 61 is viewed from a longitudinal section, the planar portion 61b extends in a direction perpendicular to the axis L. The planar portion 61b is a joint portion Cs (see FIG. 1 ) which is one end of the cylindrical portion 61a. Figure 1) is positioned in parallel. In addition, the first arc Ca1 has a curvature radius R1 of the first arc Ca1, and is a planar portion connecting arc connected to the planar portion 61b in the first boundary region Br1, and a cylindrical portion connecting arc connected to the cylindrical portion 61a in the second boundary region Br2. Further, the tangent of the first arc Ca1 (planar portion connecting arc) in the first boundary region Br1 extends in the direction along the planar portion 61b, and the tangent of the first arc Ca1 (cylindrical portion connecting arc) in the second boundary region Br2 extends in the direction along the cylindrical portion 61a. Thus, the curved portion 61c can be continuously and smoothly connected to the cylindrical portion 61a and the planar portion 61b.

[0061] In addition, the center angle θ1 formed by the first arc Ca1 (center O1, radius of curvature R1) is 90°. In addition, the 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 the straight line connecting the second boundary region Br2 and the center O1 of the first arc Ca1 is orthogonal to the axis L passing through the center of the cylindrical portion 61a.

[0062] Here, in the curved portion 61c', when the curvature radius Rf of the arc connecting the planar portion and the curvature radius Rt of the arc connecting the cylindrical portion are set, they are respectively the same as the curvature radius R1 of the first arc Ca1, that is, Rf / Rt=1. Since it does not have an extremely small curvature radius, it is possible to suppress the occurrence of stress concentration in the other end portion of the curved portion 61c (the first boundary area Br1) and one end portion of the curved portion 61c (the second boundary area Br2).

[0063] In addition, when the diameter D1 of the flat surface portion 61b and the inner diameter D2 of the cylindrical portion 61a are assumed, Figure 2 As shown, D2=D1+2×R1(=D1+Rf+Rt) (Formula 1) is satisfied. Therefore, using this (Formula 1), the diameter D1 (=D2-2×R1) of the plane portion 61b can be set by only combining two parameters (D2 and R1), so that not only the design of the housing 61 can be smoothly performed, but also the size management of the housing 61 can be easily performed.

[0064] In addition, although the wall thickness t of the plane portion 61b, the curved surface portion 61c, and the cylindrical portion 61a is uniform in this embodiment, the present invention is not limited thereto. For example, the wall thickness of the plane portion 61b, the curved surface portion 61c, and the cylindrical portion 61a near at least the second boundary region Br2 may be uniform. Figure 1 The wall thickness t of the lower side of the cylindrical portion 61a is greater than the wall thickness t of the other shells 61. Figure 1The lower side) has a cylindrical shape, but is not limited to this. For example, it can also have a flange shape, or have multiple recessed shapes along the circumferential direction.

[0065] <About the assembly process of electric valve>

[0066] From here, we will use Figure 3 and Figure 4 The deformation state of the housing 61 during the assembly process of the electric valve 100 is described. In order to emphasize the change in the axis L direction of the curved surface 61c, Figure 3 and Figure 4 Intentionally exaggerated. Figure 3 (I), (II), and (III) in the figure respectively represent the state before pressing, the state after pressing, and the state after pressing. Furthermore, the valve body 10 located at one end side of the electric valve 100 is firmly held by the holding fixture C1. In addition, during the assembly process, only the curved surface portion 61c is bent along the axis L direction, while the shapes of the flat surface portion 61b and the cylindrical portion 61a remain unchanged.

[0067] First, in Figure 3 In the state before pressing (I) shown in FIG. 1 , the specific shape of the housing 61 is similar to that of Figure 4 The pressing jig Pt corresponds to (I) in FIG. 6 , and after moving in the pressing direction M1 , it comes into contact with the flat surface portion 61 b ​​of the housing 61 .

[0068] Next, in Figure 3 In the pressing state (II) shown in FIG. 1 , the pressing jig Pt is pressed against the outer surface 61ba (refer to FIG. 1 ) of the flat surface portion 61b. Figure 4 ) applies a pressing force F1. At this time, since the flat surface portion 61b as the parallel positioning mechanism is always in contact with the joint portion Cs (refer to Figure 1 ) is positioned parallel to the housing 61, so the housing 61 does not tilt relative to the axis L, and the joint portion Cs of the cylindrical portion 61a is flush with the other end of the valve body 10 and abuts without a gap, forming a high-precision weld W. As a result, the pressure resistance of the housing 61 can be improved.

[0069] Therefore, in the electric valve 100 of this embodiment, the flat surface portion 61 b ​​as the parallel positioning mechanism is adopted in the housing 61 , thereby solving the conventional problem 1 (welding failure due to difficulty in parallel positioning) and improving the pressure resistance of the housing 61 .

[0070] In addition, considering that the housing 61 itself and the air in the housing 61 expand due to welding heat, the pressing force F1 in the pressing state (II) is set large to suppress positional deviation. When the pressing force F1 is temporarily applied to the outer surface 61ba of the flat portion 61b, as shown in FIG. Figure 4As shown in (II), while maintaining the shape of the plane portion 61b, the curved portion 61c, which is only a pressing force buffer mechanism, is bent toward one end side to generate a repulsive force F2 to buffer the larger pressing force F1. At this time, since the shape of the housing 61 continuously and smoothly connects the plane portion 61b, the curved portion 61c, and the cylindrical portion 61a, it is possible to suppress the stress concentration in the housing 61. In addition, when the curved portion 61c, which is a pressing force buffer mechanism, is bent toward one end side, the bending of the curved portion 61c in any longitudinal section is uniform, and since the horizontality of the plane portion 61b is always maintained, the positioning accuracy of the parallel positioning mechanism (plane portion 61b) is not affected.

[0071] Therefore, in the electric valve 100 of this embodiment, the curved surface 61c as a pressure buffering mechanism is adopted in the shell 61, thereby solving the previous problem 2 (large stress concentration caused by the pressing force during assembly), and preventing the shell 61 from being damaged, thereby providing the shell 61 with pressure resistance.

[0072] Next, in Figure 3 In the state after pressing (III) shown in FIG. 1 , 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 in contact with the pressing jig Pt as shown in FIG. Figure 4 The shape of the curved surface portion 61 c before deformation, that is, the shape of the housing 61 before deformation, is restored as shown in (III).

[0073] In summary, in the electric valve 100 of the present embodiment, by simultaneously using the plane portion 61b as a parallel positioning mechanism and the curved portion 61c as a pressing force buffering mechanism, when the pressing force F1 is temporarily applied to the outer surface 61ba of the plane portion 61b, the joint portion Cs of the cylindrical portion 61a is flush with the other end of the valve body 10 and abuts without a gap, while only the curved portion 61c can be continuously and smoothly connected to the plane portion 61b and the cylindrical portion 61a and bend. As a result, the electric valve 100 of the present embodiment solves the previous problem 1 (poor welding due to difficulty in parallel positioning) and the previous problem 2 (large stress concentration caused by the pressing force during assembly) at the same time, and can improve the pressure resistance performance of the housing 61.

[0074] <Regarding matters>

[0075] In the electric valve 100 of the present embodiment, the housing 61 is integrally formed. Here, when the housing 61 is formed by cutting, although the dimensional length of the housing 61 in the direction of the axis L can be controlled with extremely high precision, there is a concern about increased manufacturing costs. In contrast, when the housing 61 is integrally formed by stamping without cutting, the manufacturing cost can be suppressed due to deep drawing of a sheet of plate-like material, but on the other hand, there will be a dimensional error (individual difference) along the axis L direction, or a flat portion 61b with a smaller degree of work hardening. Therefore, the inventors considered concerns 1 and 2 when the housing 61 is integrally formed by stamping in order to suppress the manufacturing cost of the housing 61.

[0076] <Concern 1 (Productivity reduction due to dimensional error detection of the housing)>

[0077] Although omitted from the illustration, usually, when a shell 61 having a dimensional error (individual difference) in the direction of the axis L is assembled to the valve body 10, in order to absorb the dimensional error in the direction of the axis L, it is necessary to move the pressing clamp Pt by a predetermined pressing amount Pv along the pressing direction M1 from the reference abutting position after detecting the abutting position of the pressing clamp Pt with the flat surface 61b of the shell 61 using a contact sensor or the like.

[0078] However, each time the process of assembling the shell 61 to the valve body 10 is performed in the production line, it is necessary to detect the abutment position of the pressing clamp Pt, so there is a concern that the productivity of the electric valve 100 will be extremely reduced (hereinafter referred to as "Concern 1 (Reduced productivity due to dimensional error detection of the shell)").

[0079] <About the housing dimensional error absorption mechanism>

[0080] In contrast, in this embodiment, the curved surface portion 61c is used as a housing dimension error absorbing mechanism, and in the pressed state (see Figure 3 Under (II)), the actual size of the cylindrical length L1 remains unchanged, and only the curved surface 61c is bent, thereby absorbing the dimensional error (individual difference) of the shell 61 and solving concern 1 (reduced productivity due to dimensional error detection of the shell).

[0081] Since the housing 61 is an important component in determining the length of the electric valve 100 in the direction of the axis L, the dimensional tolerance of the housing 61 in the direction of the axis L, that is, the difference between the maximum allowable dimension and the minimum allowable dimension in the allowable range, has been determined in the design stage. Figure 3As shown in (II), first, a value obtained by subtracting a predetermined pressing amount Pv from the minimum allowable dimension Lmin (≤ the actual dimension of the housing length Lo) is calculated in advance as the housing length Ld during pressing. Then, the pressing jig Pt is moved along the pressing direction M1 so that the length of the housing 61 in the direction of the axis L is uniformly the predetermined housing length Ld during pressing.

[0082] Specifically, in Figure 3 In the state before pressing (I) shown in the figure, the cylindrical portion 61a and the curved portion 61c respectively have the actual size of the cylindrical portion length L1 (unchanged) and the actual size of the curved portion length L2 (variable) in the direction of the axis L, and the housing 61 has: the actual size of the housing length L0 (= L1 + L2) with a dimensional error (individual difference) in the direction of the axis L. Next, Figure 3 In the pressing state (II) shown in the figure, the pressing fixture Pt is moved along the pressing direction M1 in such a way that the actual shell length L0 is equal to the shell length Ld during pressing. At this time, the cylindrical portion 61a and the curved portion 61c respectively have the actual cylindrical portion length L1 (unchanged) and the curved portion length L2' (variable) during pressing in the direction of the axis L, and the shell 61 has the shell length Ld (=L1+L2') during pressing in the direction of the axis L. Furthermore, Figure 3 In the state after pressing (III) shown in the figure, the housing 61, the cylindrical portion 61a and the curved portion 61c respectively have (I) the same length in the direction of the axis L as in the state before pressing, namely, the actual size housing length L0, the actual size cylindrical portion length L1 (unchanged) and the actual size curved portion length L2 (variable). In addition, in the assembly process of this embodiment, by making the maximum deflection of the curved portion 61c as the housing size error absorption mechanism greater than the size tolerance, the size error (individual difference) of the housing 61 can be reliably absorbed.

[0083] Thus, in this embodiment, Figure 3 In the pressing state (II) shown, the pressing jig Pt is pressed into the flat surface portion 61b so that the length of the housing 61 in the direction of the axis L is uniformly the predetermined housing length Ld during pressing. As a result, only the curved surface portion 61c, which is a housing dimension error absorption mechanism, is bent, and the dimension error (individual difference) of the housing 61 can be absorbed, thereby solving the concern 1 (reduction in productivity due to the detection of the dimension error of the housing) and improving the productivity of the electric valve 100.

[0084] <Regarding Concern 2 (Cracks in the Flat Part Due to Abnormally High Pressure)>

[0085] In recent years, in order to improve the coefficient of performance (COP) in refrigeration cycle systems, it has been required to use carbon dioxide or the like at a higher pressure as a refrigerant than HFC, HFO, etc. that have been used in the past.

[0086] Therefore, in the electric valve 100 of this embodiment, when carbon dioxide is used as the refrigerant, since the operating pressure is high, a large force due to the pressure toward the other end side in the axis L direction may be applied to the flat surface portion 61b and the curved surface portion 61c.

[0087] Here, generally, when an internal pressure is applied to a thin-walled cylindrical pressure vessel with uniform wall thickness, a circumferential stress in the circumferential direction and an axial stress in the axial direction are generated as stresses to bear the pressure. Although detailed description is omitted, the axial stress is 1 / 2 times the circumferential stress. This description can be applied to the shell 61 having a substantially cylindrical shape in the same manner.

[0088] In this way, since the axial stress is 1 / 2 times the circumferential stress, theoretically, when the wall thickness t of the shell 61 is uniform, there is no possibility that the planar portion 61b and the curved portion 61c expand and rupture in the direction of the axis L before the cylindrical portion 61a expands and ruptures in the circumferential direction.

[0089] However, when the housing 61 is integrally formed by press working, since a single plate-like material is deep-drawn to form a bottomed cylindrical shape, the degree of work hardening varies among the flat portion 61 b ​​, the curved surface portion 61 c , and the cylindrical portion 61 a .

[0090] Specifically, during the stamping process, the thickness of the base material of the planar portion 61b is roughly maintained, while the cylindrical portion 61a and the curved portion 61c are plastically deformed by drawing. Therefore, since the degree of work hardening of the planar portion 61b is smaller than that of the cylindrical portion 61a and the curved portion 61c, when an abnormally high pressure (maximum operating pressure < abnormally high pressure ≤ withstand pressure) is applied to the housing 61, the planar portion 61b becomes easily deformed and there is a concern of rupture (hereinafter referred to as "concern 2 (rupture of the planar portion due to abnormally high pressure)").

[0091] <About abnormally high pressure buffer mechanism>

[0092] In contrast, in this embodiment, if Figure 5As shown, the housing 61 is integrally formed by stamping, and the wall thickness t of the plane portion 61b, the curved surface portion 61c, and the cylindrical portion 61a near at least the second boundary region Br2 is uniform, and the plane portion 61b and the curved surface portion 61c are used as an abnormally high pressure buffer mechanism. Thus, when an abnormally high pressure in the direction of the axis L is temporarily applied to the inner surface of the plane portion 61b and the curved surface portion 61c, the plane portion 61b and the curved surface portion 61c are smoothly bent in a manner of being continuously connected to the cylindrical portion 61a, and are expressed in a substantially hemispherical shape, thereby buffering the temporary load caused by the abnormally high pressure and solving the concern 2 (rupture of the plane portion due to the abnormally high pressure).

[0093] The following uses Figure 5 The abnormally high pressure buffer mechanism is specifically described. In order to emphasize the change in the direction of the axis L of the flat surface portion 61b and the curved surface portion 61c, Figure 5 Intentionally exaggerated.

[0094] First, in the electric valve 100 of the present embodiment, the pressure resistance design is performed in advance so that the electric valve 100 can be operated at a normal operating pressure (Pnl) (see Figure 5 The wall thickness t of the shell 61 is appropriately selected in order to maintain the shape of the shell 61 under the pressure (solid line in the figure). Therefore, under the normal use pressure (Pnl), the plane portion 61b, the curved surface portion 61c, and the cylindrical portion 61a have a uniform wall thickness t and are continuously and smoothly connected to each other. Therefore, under the normal use pressure (Pnl), the shape of the shell 61 is maintained, so that deformation does not occur.

[0095] On the other hand, in the electric valve 100 of the present embodiment, due to the abnormally high pressure (Pabn) state (refer to Figure 5 ), an abnormally high pressure Pabn in the direction of the axis L is applied to the inner surface 61bb of the planar portion 61b, and the planar portion 61b and the curved surface portion 61c are intentionally smoothly bent in a manner continuously connected to the cylindrical portion 61a, and deformed into a roughly hemispherical shape consisting of the curved surface portion 61bc on the other end side and the curved surface portion 61c, thereby being able to buffer the temporary load caused by the abnormally high pressure.

[0096] Thus, in the electric valve 100 of the present embodiment, under the normal use pressure (Pnl) state, the housing 61 does not deform, but under the abnormally high pressure (Pabn) state, the flat surface portion 61b and the curved surface portion 61c as the abnormally high pressure buffer mechanism are smoothly bent in a manner of being continuously connected to the cylindrical portion 61a, and deformed into a substantially hemispherical shape. Thus, the electric valve 100 of the present embodiment solves the concern 2 (rupture of the flat surface portion due to abnormally high pressure) and can prevent leakage to the outside.

[0097] <About Reversibly Deformable Abnormally High Pressure Buffer Mechanism>

[0098] As described above, in the abnormally high pressure buffer mechanism, since the work hardening degree of the plane portion 61b is smaller than that of the curved portion 61c, if the deflection generated in the plane portion 61b becomes too large under the abnormally high pressure (Pabn) state, the deformed other end side curved portion 61bc may be plastically deformed. Therefore, even if the abnormally high pressure (Pabn) state is changed to the normal use pressure (Pnl) state again, the other end side curved portion 61bc may not be reversibly returned to the plane portion 61b.

[0099] In contrast, the inventors conducted intensive research using simulation and determined the upper limit value of the diameter D1 of the planar portion 61b. They found that under an abnormally high pressure (Pabn) state, the deflection of the curved surface portion 61bc on the other end side can be made smaller, that is, only elastic deformation occurs on the curved surface portion 61bc on the other end side, and it can reversibly return to the planar portion 61b.

[0100] Specifically, the upper limit value of the diameter D1 of the plane portion 61b is set to be less than one third of the inner diameter D2 of the cylindrical portion 61a (D1≤1 / 3×D2). Here, preferably, the upper limit value of the diameter D1 of the plane portion 61b is set to be less than one quarter of the inner diameter D2 of the cylindrical portion 61a (D1≤1 / 4×D2), and more preferably, the upper limit value of the diameter D1 of the plane portion 61b is set to be less than one fifth of the inner diameter D2 of the cylindrical portion 61a (D1≤1 / 5×D2). In addition, the lower limit value of the diameter D1 of the plane portion 61b can be set to the area that the pressing fixture Pt can press, for example, it is set to a value that exceeds twice the wall thickness t of the shell 61.

[0101] In addition, between the diameter D1 of the planar portion 61b and the inner diameter D2 of the cylindrical portion 61a, in addition to the aforementioned size relationship of D1≤1 / 3×D2, based on the aforementioned (Formula 1), the relationship of D1=D2-2×R1 is also satisfied.

[0102] Thus, in the electric valve 100 of the present embodiment, by setting the upper limit value of the diameter D1 of the planar portion 61b to less than one-third (D1≤1 / 3×D2) of the inner diameter D2 of the cylindrical portion 61a, preferably less than one-fourth (D1≤1 / 4×D2), and more preferably less than one-fifth (D1≤1 / 5×D2), when the abnormally high pressure (Pabn) state is converted back to the normal use pressure (Pnl) state, the other end side curved surface portion 61bc can reversibly and reliably return to the planar portion 61b.

[0103] In summary, the electric valve 100 of the present embodiment adopts the plane portion 61b as a parallel positioning mechanism and the curved portion 61c as a pressing force buffering mechanism, thereby solving the conventional problem 1 (poor welding 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 of the housing 61. In addition, in the electric valve 100 of the present embodiment, since Rf / Rt=1, the occurrence of stress concentration in the other end (first boundary region Br1) of the curved portion 61c and the one end (second boundary region Br2) of the curved portion 61c can be suppressed. Further, the electric valve 100 of the present embodiment satisfies D2=D1+2×R1(=D1+Rf+Rt), and the diameter D1 of the plane portion 61b can be set only by the combination of two parameters, so that not only the design of the housing 61 can be smoothly performed, but also the size management of the housing 61 can be easily performed. In addition, in the electric valve 100 of the present embodiment, since it is possible to generate deflection only in the curved surface portion 61c as the housing dimension error absorption mechanism and absorb the dimension error (individual difference) of the housing 61, the concern 1 (reduction in productivity due to the dimension error detection of the housing) is solved, and the productivity of the electric valve 100 can be improved. In addition, in the electric valve 100 of the present embodiment, by smoothly deflecting the flat surface portion 61b and the curved surface portion 61c as the abnormally high pressure buffer mechanism in a manner of continuously connecting to the cylindrical portion 61a and deforming into a substantially hemispherical shape, the concern 2 (rupture of the flat surface portion due to abnormally high pressure) is solved, and leakage to the outside can be prevented. Furthermore, in the electric valve 100 of the present embodiment, by setting the upper limit value of the diameter D1 of the planar portion 61b 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, the planar portion 61b and the other end side curved portion 61bc can be reversibly changed.

[0104] (Housing Variations 1 and 2 of the Present Embodiment)

[0105] Will use Figure 6 and Figure 7 The shell modification examples 1 and 2 of the present embodiment are described. The shell modification examples 1 and 2 of the present embodiment are different from the curved surface 61c of the present embodiment which is composed of a single arc in that the curved surface 61c', 61c" is composed of multiple (two or three) arcs, and the other basic structures are the same as those of the present embodiment. Here, the same reference numerals are given to the same components, and repeated descriptions are omitted. In addition, Figure 6 and Figure 7In order to visually understand the fact that the length of the shells 61', 61" in the shell variations 1 and 2 of the present embodiment in the direction of the axis L can be reduced compared to the shell 61 of the present embodiment, the diameter D1 of the planar portion 61b, the inner diameter D2 of the cylindrical portion 61a, and the wall thickness t of the shell 61' are made the same as those of the present embodiment.

[0106] (Modification 1 of the Casing of the Present Embodiment)

[0107] First, use Figure 6 The structure of the other end side of the housing 61' in the housing modification example 1 of this embodiment is described. The housing modification example 1 of this embodiment is different from the curved surface 61c of this embodiment in that the curved surface 61c' is composed of two arcs (a first arc Ca1' and a second arc Ca2'), and the other basic structures are the same as those of this embodiment. Figure 6 As shown, since the housing 61 ′ has a bilaterally symmetrical shape, only the shape of the right half is used for description.

[0108] <Structure of the other end side of the housing>

[0109] like Figure 6 As shown, the housing 61' comprises: 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' which continuously and smoothly connects the cylindrical portion 61a and the flat portion 61b, is convex toward the outer surface side, and has a circular ring shape when viewed from the direction of the axis L. The wall thickness t of the flat portion 61b, the curved portion 61c', and the cylindrical portion 61a in the housing 61' is uniform. The curved portion 61c' is composed of two arcs (a first arc Ca1' and a second arc Ca2').

[0110] Specifically, when the housing 61' is viewed from a longitudinal section, as in the present embodiment, the planar portion 61b extends in a direction perpendicular to the axis L and is joined to a joint portion Cs (see FIG. 1 ) which is one end of the cylindrical portion 61a. Figure 1 ) is positioned in parallel. In addition, the first arc Ca1' has a curvature radius R1' of the first arc Ca1', and is a connecting arc of the planar portion connected to the planar portion 61b in the first boundary region Br1. Further, the second arc Ca2' has a curvature radius R2' of the second arc Ca2', and is a connecting arc of the cylindrical portion connected 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.

[0111] Here, the tangent of the first circular arc Ca1' (the planar part connecting circular arc) in the first boundary region Br1 extends in the direction along the planar part 61b, and the tangent of the second circular arc Ca2' (the cylindrical part connecting circular arc) in the second boundary region Br2 extends in the direction along the cylindrical part 61a. Thus, the curved surface part 61c' can be continuously and smoothly connected to the cylindrical part 61a and the planar part 61b. In addition, the tangents of the first circular arc Ca1' and the second circular arc Ca2' in the third boundary region Br3 extend in the direction along the same line. In this way, the curved surface part 61c' composed of two circular arcs is a continuously and smoothly connected curve.

[0112] In addition, the sum of the central angle θ1' formed by the first circular arc Ca1' (center O1', radius of curvature R1') and the central angle θ2' formed by the second circular arc Ca2' (center O2', radius of curvature R2') is 90°. Further, the line connecting the center O1' of the first boundary region Br1 and the first circular arc Ca1' is parallel to the axis L passing through the center of the cylindrical part 61a, and the line connecting the center O2' of the second boundary region Br2 and the second circular arc Ca2' is orthogonal to the axis L passing through the center of the cylindrical part 61a. Furthermore, the distance a1 between the center O1' of the first circular arc Ca1' and the center O2' of the second circular arc Ca2' is equal to the difference between the radius of curvature R1' of the first circular arc Ca1' and the radius of curvature R2' of the second circular arc Ca2'.

[0113] In the case of the housing deformation example 1 of the present embodiment, by disposing the second boundary region Br2, which is the other end of the cylindrical part 61a, on one end side with the center O1' of the first circular arc Ca1' (the planar part connecting circular arc), the length of the housing 61' in the direction of the axis L can be shortened by a reduction amount Rq2 compared to the length of the housing 61 in the present embodiment.

[0114] Here, when the radius of curvature of the planar part connecting circular arc is set as Rf and the radius of curvature of the cylindrical part connecting circular arc is set as Rt, they respectively correspond to the radius of curvature R1' of the first circular arc Ca1' and the radius of curvature R2' of the second circular arc Ca2' as shown in Figure 6 where Rf (R1') > Rt (R2'). Here, in the curved surface part 61c', by setting the relationship of 1 < Rf / Rt < 2, it is possible to prevent either the radius of curvature Rf of the planar part connecting circular arc or the radius of curvature Rt of the cylindrical part connecting circular arc from being an extremely small radius of curvature compared to the other, and thus 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 part 61c'.

[0115] In addition, in the case of the housing deformation example 1 of the present embodiment, Rf (R1') > Rt (R2'), and the relationship of 1 < Rf / Rt < 2 is set, but it is not limited thereto. For example, Rf (R1') < Rt (R2') may also be set, and the relationship of 1 < Rt / Rf < 2 is set. Similar to the above relationship, the occurrence of stress concentration can be suppressed.

[0116] In addition, when the diameter of the flat portion 61b is D1 and the inner diameter of the cylindrical portion 61a is D2, as Figure 6 shown,

[0117] D2 = D1 + 2×(b1 + R2') (Equation 2)

[0118] θ1' + θ2' = 90° (Equation 3)

[0119] b1 = a1×sinθ1' (Equation 4)

[0120] a1 = R1' - R2' (Equation 5),

[0121] wherein, substituting (Equation 4) and (Equation 5) into (Equation 2),

[0122] then D2 = D1 + 2×((R1' - R2')×sinθ1' + R2') (Equation 6) is satisfied.

[0123] Using this (Equation 6), the size of the diameter D1 of the flat portion 61b (= D2 - 2×((R1' - R2')×sinθ1' + R2')) can be appropriately set.

[0124] In addition, in (Equation 6), when θ1' = 30° and θ2 = 60°,

[0125] D2 = D1 + R1' + R2' (= D1 + Rf + Rt) (Equation 7).

[0126] Therefore, using this (Equation 7), the diameter D1 of the flat portion 61b (= D2 - (R1' + R2')) can be set only by the combination of three parameters. Therefore, not only can the design of the housing 61' be carried out smoothly, but also the size management of the housing 61' can be easily carried out.

[0127] In summary, as in this embodiment, the first housing deformation example of this embodiment simultaneously adopts a parallel positioning mechanism (flat portion 61b) and a pressing force buffering mechanism (curved surface portion 61c'), and simultaneously solves the conventional problem 1 (welding defects caused by difficult 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 housing 61'. In addition, in the first housing deformation example of this embodiment, since 1 < Rf / Rt < 2, the occurrence of stress concentration in the other end portion (first boundary region Br1) and one end portion (second boundary region Br2) of the curved surface portion 61c' can be suppressed. Further, as in this embodiment, in the first housing deformation example of this embodiment, when D2 = D1 + R1' + R2' (= D1 + Rf + Rt) (when θ1' = 30° and θ2 = 60°), the diameter D1 of the flat portion 61b can be set only by the combination of three parameters. Therefore, not only can the design of the housing 61' be carried out smoothly, but also the dimension management of the housing 61' can be easily performed. Moreover, as in this embodiment, the first housing deformation example of this embodiment adopts a housing size error absorption mechanism (curved surface portion 61c'), solves concern 1 (decrease in productivity due to detection of housing size errors), and can improve the productivity of the electric valve 100. In addition, as in this embodiment, the first housing deformation example of this embodiment adopts an abnormal high pressure buffering mechanism (flat portion 61b and curved surface portion 61c'), solves concern 2 (rupture of the flat portion due to abnormal high pressure), and can prevent leakage to the outside. Further, as in this embodiment, in the first housing deformation example of this embodiment, by setting the upper limit value of the diameter D1 of the flat portion 61b to be one-third or less (D1 ≤ 1 / 3 × D2), preferably one-fourth or less (D1 ≤ 1 / 4 × D2), more preferably one-fifth or less (D1 ≤ 1 / 5 × D2) of the inner diameter D2 of the cylindrical portion 61a, the flat portion 61b can be reversibly changed. Moreover, in the first housing deformation example of this embodiment, by arranging the center O1' of the first circular arc Ca1' (flat portion connecting circular arc) on the one end side with respect to the second boundary region Br2 which is the other end portion of the cylindrical portion 61a, the length of the housing 61' in the axis L direction can be shortened by a reduction amount Rq2 compared to the length of the housing 61 in this embodiment.

[0128] (The second housing deformation example of this embodiment)

[0129] First, use Figure 7The structure of the other end side of the housing 61" in the housing modification example 2 of the present embodiment is described. The housing modification example 2 of the present embodiment is different from the curved surface 61c of the present embodiment in that the curved surface 61c" is composed of three arcs (a first arc Ca1", a second arc Ca2", and a third arc Ca3"), and the other basic structures are the same as those of the present embodiment. In addition, as Figure 7 As shown, since the housing 61" has a bilaterally symmetrical shape, only the shape of the right half is used for description.

[0130] <Structure of the other end side of the housing>

[0131] like Figure 7 As shown, the shell 61" includes: a cylindrical portion 61a, which extends in the direction of the axis L and has a cylindrical shape; a planar portion 61b, which has a circular shape when viewed from the direction of the axis L; and a curved portion 61c", which continuously and smoothly connects the cylindrical portion 61a and the planar portion 61b, is convex toward the outer surface side, and has a circular ring shape when viewed from the direction of the axis L. The wall thickness t of the planar portion 61b, the curved portion 61c", and the cylindrical portion 61a in the shell 61" is uniform. The curved portion 61c" is composed of three arcs (a first arc Ca1", a second arc Ca2", and a third arc Ca3").

[0132] Specifically, when the housing 61" is viewed from a longitudinal section, as in the present embodiment, the flat portion 61b extends in a direction perpendicular to the axis L and is joined to the joint portion Cs (see FIG. Figure 1 ) is a parallel positioning mechanism for positioning in parallel. In addition, the first arc Ca1" has a curvature radius R1" of the first arc Ca1", and is an arc connected to the planar portion connected to the planar portion 61b in the first boundary area Br1. Further, the second arc Ca2" has a curvature radius R2" of the second arc Ca2", and is an arc connected to the cylindrical portion connected to the cylindrical portion 61a in the second boundary area Br2. In addition, the third arc Ca3" has a curvature radius R3" of the third arc Ca3", and is connected to the first arc Ca1" in the third boundary area Br3, and is connected to the second arc Ca2" in the fourth boundary area Br4.

[0133] Here, the tangent of the first arc Ca1" (arc connecting the plane portion) in the first boundary area Br1 extends in the direction along the plane portion 61b, and the tangent of the second arc Ca2" (arc connecting the cylindrical portion) in the second boundary area Br2 extends in the direction along the cylindrical portion 61a. Thus, the curved portion 61c" can be continuously and smoothly connected to the cylindrical portion 61a and the flat portion 61b. In addition, while the tangents of the first arc Ca1" and the third arc Ca3" in the third boundary area Br3 extend in the direction along the same line, the tangents of the second arc Ca2" and the third arc Ca3" in the fourth boundary area Br4 extend in the direction along the same line. In this way, the curved portion 61c" composed of three arcs is a continuously and smoothly connected curve.

[0134] In addition, the sum of the center angle θ1” formed by the first arc Ca1” (center O1”, radius of curvature R1”), the center angle θ2” formed by the second arc Ca2” (center O2”, radius of curvature R2”), and the center angle θ3” formed by the third arc Ca3” (center O3”, radius of curvature R3”) is 90°. In addition, the straight line connecting the first boundary area 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 the straight line connecting the second boundary area Br2 and the center O2” of the second arc Ca2” is orthogonal to the axis L passing through the center of the cylindrical portion 61a. Furthermore, the 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 curvature radius R1” of the first arc Ca1” and the curvature radius R3” of the third arc Ca3”. In addition, the 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 curvature radius R3” of the third arc Ca3” and the curvature radius R2” of the second arc Ca2”.

[0135] In shell variation example 2 of the present embodiment, by arranging the center O1" of the first arc Ca1" (arcs connected by the plane portion) on one end side relative to the second boundary area Br2 which is the other end of the cylindrical portion 61a, the length of the shell 61" in the direction of the axis L can be shortened by a reduction amount Rq3 than the length of the shell 61 in the present embodiment.

[0136] Here, when the curvature radius of the connecting arc of the planar portion is Rf, and the curvature radius of the connecting arc of the cylindrical portion is Rt, respectively, Figure 7As shown, corresponding to the radius of curvature R1” of the first circular arc Ca1” and the radius of curvature R2” of the second circular arc Ca2”, and Rf(R1”) > Rt(R2”). Here, by setting the relationship of 1 < Rf / Rt < 2, it is possible to prevent either the radius of curvature Rf of the circular arc connecting the planar portion or the radius of curvature Rt of the circular arc connecting the cylindrical portion from being an extremely small radius of curvature compared to the other, and thus it is possible to suppress the occurrence of stress concentration in the other end portion (the first boundary region Br1) and one end portion (the second boundary region Br2) of the curved surface portion 61c”.

[0137] In addition, in the case of the housing deformation 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 thereto. For example, it is also possible to set Rf(R1”) < Rt(R2”), and set 1 < Rt / Rf < 2, and as in the above relationship, it is possible to suppress the occurrence of stress concentration.

[0138] In addition, when the diameter of the planar portion 61b is D1 and the inner diameter of the cylindrical portion 61a is D2, as Figure 7 shown,

[0139] D2 = D1 + 2×(b1” + b3 + R2”) (Equation 8)

[0140] θ1” + θ2” + θ3” = 90° (Equation 9)

[0141] b1” = a1”×sinθ1” (Equation 10)

[0142] a1” = R1” - R3” (Equation 11)

[0143] b3 = a3×cosθ2” (Equation 12)

[0144] a3 = R3” - R2” (Equation 13),

[0145] Here, substituting (Equation 10) to (Equation 13) into (Equation 8),

[0146] then D2 = D1 + 2×((R1” - R3”)×sinθ1” + (R3” - R2”)×cosθ2” + R2”) (Equation 14) is satisfied.

[0147] Using this (Equation 14), the size of the diameter D1 of the planar portion 61b (= D2 - 2×((R1” - R3”)×sinθ1” + (R3” - R2”)×cosθ2” + R2”)) can be appropriately set.

[0148] In summary, like the present embodiment, the second housing deformation example of the present embodiment solves 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) by simultaneously adopting a parallel positioning mechanism (flat portion 61b) and a pressing force buffering mechanism (curved portion 61c”), and can improve the pressure resistance performance of the housing 61”. In addition, like the first housing deformation example, in the second housing deformation example of the present embodiment, since 1 < Rf / Rt < 2, the occurrence of stress concentration in the other end portion (first boundary region Br1) and one end portion (second boundary region Br2) of the curved portion 61c” can be suppressed. Further, like the present embodiment, the second housing deformation example of the present embodiment solves the concern 1 (decrease in productivity due to detection of housing dimensional errors) by adopting a housing dimensional error absorption mechanism (curved portion 61c”), and can improve the productivity of the electric valve 100. Moreover, like the present embodiment, the second housing deformation example of the present embodiment solves the concern 2 (rupture of the flat portion due to abnormally high pressure) by adopting an abnormally high pressure buffering mechanism (flat portion 61b and curved portion 61c”), and can prevent leakage to the outside. In addition, like the present embodiment, in the second housing deformation example of the present embodiment, by setting the upper limit value of the diameter D1 of the flat portion 61b to be one-third or less (D1 ≤ 1 / 3 × D2), preferably one-fourth or less (D1 ≤ 1 / 4 × D2), more preferably one-fifth or less (D1 ≤ 1 / 5 × D2) of the inner diameter D2 of the cylindrical portion 61a, the flat portion 61b can be reversibly deformed. Further, like the first housing deformation example, in the second housing deformation example of the present embodiment, by arranging the center O1” of the first circular arc Ca1” (flat portion connecting circular arc) on the one end side with respect to the second boundary region Br2 which is the other end portion of the cylindrical portion 61a, the length of the housing 61” in the axis L direction can be made shorter by a reduction amount Rq3 (< Rq2) than the length of the housing 61 in the present embodiment.

[0149] In addition, the curved portions 61c, 61c’, 61c” in the present embodiment (including the first and second housing deformation examples) are composed of one to three circular arcs, but are not limited thereto. For example, as long as it is a continuously and smoothly connected curved portion, it may also include those composed of four or more circular arcs.

[0150] <Regarding the refrigeration cycle system>

[0151] Will utilize Figure 8The refrigeration cycle system of the present invention is described. The refrigeration cycle system includes an expansion valve 100 using the electric valve 100 of the present embodiment (including shell modification examples 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 respectively connected by pipes to form a heat pump refrigeration cycle. In addition, illustrations of accumulators, pressure sensors, temperature sensors, etc. are omitted.

[0152] The flow path of the refrigeration cycle is switched into two flow paths, a flow path during cooling operation and a flow path during heating operation, by the flow path switching valve 400. During cooling operation (refer to 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, and the outdoor heat exchanger 200 functions as a condenser, and the liquid refrigerant flowing out of the outdoor heat exchanger 200 flows into the indoor heat exchanger 300 via the expansion valve 100, and the indoor heat exchanger 300 functions as an evaporator.

[0153] On the other hand, during heating operation (refer to the dotted arrow in the figure), the refrigerant compressed by the compressor 500 circulates from the flow path switching valve 400 in the order of the indoor heat exchanger 300, the expansion valve 100, the outdoor heat exchanger 200, the flow path switching valve 400, and the compressor 500, and the indoor heat exchanger 300 functions as a condenser, and the outdoor heat exchanger 200 functions as an evaporator. Therefore, the expansion valve 100 can decompress and expand the liquid refrigerant flowing from the outdoor heat exchanger 200 during cooling operation or the liquid refrigerant flowing from the indoor heat exchanger 300 during heating operation, thereby controlling the flow rate of the refrigerant.

[0154] In addition, the present invention is not limited to the present embodiment (including shell variation 1 and 2), including other structures that can achieve the purpose of the present invention, and the following variations are also included in the present invention. For the electric valve 100 of the present embodiment (including shell variation 1 and 2), the electric valve 100 applied to air conditioners such as household air conditioners in addition to the refrigeration cycle system is illustrated, but the electric valve of the present invention is not limited to household air conditioners, but can also be commercial air conditioners, and is not limited to air conditioners, and can also be applied to water heaters, or various refrigerators, etc. In addition, in the present embodiment (including shell variation 1 and 2), the shell having a flat portion, a curved portion, and a cylindrical portion is applied to the electric valve 100 as a housing drive portion (a driving component that causes a rotational motion, etc.), but it is not limited to this. For example, the shell having a flat portion, a curved portion, and a cylindrical portion can also be applied to the solenoid valve as a plunger tube that accommodates the drive portion (a driving component that causes a linear reciprocating motion, etc.).

[0155] <Others>

[0156] Obviously, the electric valve 100 of this embodiment (including shell variants 1 and 2) can be applied not only to the refrigeration cycle illustrated, but also to all fluid devices and fluid circuits. In addition, the present invention is not limited to the above-mentioned modes, embodiments, and variants described everywhere, and appropriate changes or modifications can be made within the scope of the technical concept of the present invention.

Claims

1. An electric valve, comprising: a valve body having a valve port; a valve body that controls the opening area of ​​the valve port; a drive unit that moves the valve body forward and backward; a parallel positioning mechanism; and a pressing force buffer mechanism, wherein the electric valve is characterized in that: The driving unit includes a driving member and a housing, wherein the housing accommodates the driving member and is connected to the valve body and is integrally formed. The housing comprises: 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 a circular ring shape when viewed from the axial direction. When the housing is viewed in longitudinal section, The curved surface portion includes: a planar portion connecting arc connected to the planar portion in a first boundary region and having a predetermined curvature radius; and a cylindrical portion connecting arc connected to the cylindrical portion in a second boundary region and having a predetermined curvature radius, A tangent line connecting the arcs of the planar portions in the first boundary region extends in a direction along the planar portions, The tangent line of the cylindrical portion connecting arcs in the second boundary region extends in a direction along the cylindrical portion, The parallel positioning mechanism is the plane portion that positions one end of the housing and the other end of the valve body parallel to each other. The pressing force buffering mechanism includes the curved surface portion consisting of one or more arcs when the housing is viewed in a longitudinal section, and when a pressing force in the axial direction is applied to the outer surface of the planar portion, the curved surface portion is bent to buffer the pressing force.

2. The electric valve according to claim 1, characterized in that: Assuming that the curvature radii of the planar portion connecting arc and the cylindrical portion connecting arc are Rf and Rt respectively, the relationship is set to 1≤Rf / Rt<2.

3. The electric valve according to claim 1, characterized in that: Assuming that the curvature radii of the connecting arc of the planar portion and the connecting arc of the cylindrical portion are Rf and Rt respectively, the inner diameter of the cylindrical portion is D2, and the diameter of the planar portion is D1, the relationship is set to D2=Rf+Rt+D1.

4. The electric valve according to claim 1, characterized in that: When the housing is viewed in longitudinal section, The curved surface portion is composed of two or more arcs, The center of the planar portion connecting arc is arranged closer to one end side than the other end portion of the cylindrical portion.

5. The electric valve according to claim 1, characterized in that: It also has a shell size error absorption mechanism. The housing is integrally formed by stamping. The housing dimensional error absorbing mechanism is the curved surface portion, and when the pressing force is applied to the outer surface of the planar portion, the curved surface portion is bent to move only the planar portion in the axial direction to absorb the dimensional error of the housing.

6. The electric valve according to claim 1, characterized in that: It also has an abnormally high pressure buffer mechanism. The housing is integrally formed by press working, and the wall thickness of each of the planar portion, the curved portion, and at least the cylindrical portion near the second boundary region is uniform. The abnormally high pressure buffer mechanism is the planar portion and the curved portion. When an abnormally high pressure in the axial direction is applied to the inner surface of the planar portion, the load caused by the abnormally high pressure is buffered by bending the planar portion and the curved portion in a manner continuously connected to the cylindrical portion and deforming into a roughly hemispherical shape.

7. A refrigeration cycle system comprising a compressor, a condenser, an expansion valve, and an evaporator, wherein the refrigeration cycle system is characterized in that: As the expansion valve, the electric valve according to any one of claims 1 to 6 is used.

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