Electric valve and refrigeration cycle system including the same

Abstract

The electric valve has a configuration that allows for high-precision alignment of the axial centers of the housing case and the valve body during assembly, without requiring complex assembly precision control. [Solution] The electric valve 100 comprises a rotor shaft 131 fixed to the central axis CL of the magnet rotor 141 and having a male threaded portion 131a, a valve body housing 111 in which a valve chamber 111A, ports 111b, 111c, and a joint portion 111d are formed, a female threaded member 132 in which a female threaded portion 132b is formed to be screw-connected to the male threaded portion 131a, a fixing bracket 133 formed in a plate shape and integrally fixed to the female threaded member 132, and a cup-shaped housing case 151. The outer circumference of the fixing bracket 133 is formed along a virtual circle CI with a radius from the central axis CL to the part furthest from the central axis CL and fitted inside the housing case 151, and a welded portion 133d is formed in the part other than the guide portion 133c that is welded and fixed to the joint portion 111d of the valve body housing 111.

Description

Technical Field

[0001] The present invention relates to an electric valve and a refrigeration cycle system including the same.

Background Art

[0002] In a heat pump type refrigeration cycle system, an electric valve used as an electric expansion valve is known, for example, as described in FIG. 1 of Patent Document 1.

[0003] The electric valve includes a stepping motor, a valve housing as a valve body portion, a valve mechanism portion, and a sealed case as a housing case. The stepping motor includes a rotor shaft, a magnetic rotor inside the sealed case, and a stator coil disposed to face the magnetic rotor on the outer peripheral portion of the sealed case. The male screw portion of the rotor shaft is screwed into the female screw portion of a support member of the valve mechanism portion described later. The valve housing has a valve chamber that communicates with the inside of the first joint pipe and communicates with the inside of the second joint pipe through a valve port of a valve seat ring. The valve mechanism portion has a support member, a valve holder, and a needle valve. The synthetic resin support member is fixed to the upper end surface of the above-described valve housing by welding through a stainless steel flange portion as an insert-molded fixing fitting. Further, the opening end surface of the lower portion of the sealed case is welded to the upper end surface of the valve housing at a position spaced apart from the outer peripheral portion of the above-described flange portion by a predetermined gap.

[0004] In order for the rotor shaft and the magnetic rotor to rotate smoothly by the operation of the stepping motor, an appropriate gap is formed between the inner peripheral surface of the sealed case and the outer peripheral surface of the magnetic rotor, and the central axis of the sealed case welded to the upper end surface of the valve housing needs to be on the central axis of the valve housing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] As disclosed in the aforementioned Patent Document 1, the lower open end face of the sealing case 1051 is welded to the upper end face of the valve housing 1011 at a position separated by a predetermined gap Δg from the outer circumference of the flange portion 1033, which serves as the fixing bracket, as shown in a partially enlarged view in Figure 8(a) of the attached drawings of this application. Note that in Figure 8(a), the illustration of the bead between the sealing case 1051 and the valve housing 1011 is omitted. The predetermined gap Δg is provided in this way to prevent the inner circumferential surface of the lower end of the sealing case 1051 from riding up onto the formed bead (weld buildup) 1033w when the lower open end face of the sealing case 1051 and the upper end face of the valve housing 1011 are welded, and when the outer circumference of the flange portion 1033 and the upper end face of the valve housing 1011 (annular joint portion 1011d) are fillet welded. If the gap Δg described above is not provided between the lower inner surface of the sealing case 1051 and the outer surface of the flange portion 1033, the lower inner surface of the sealing case 1051' will ride up onto the bead (weld build-up portion) 1033w', as partially enlarged in Figures 9(a) and 9(b). As a result, the axis of the sealing case 1051' will be misaligned with the axis of the valve housing 1011', and an axial gap Δg' will be formed between the sealing case 1051' and the valve housing 1011'. Therefore, depending on the size of the gap Δg', there is a risk that the lower open end surface of the sealing case 1051' cannot be welded to the upper end surface of the valve housing 1011'.

[0007] When such welding work is performed, the sealed case 1051 and the valve housing 1011 are positioned and held by fixtures in the welding machine so that the central axis of the sealed case 1051 and the central axis of the valve housing 1011 are on the same central axis.

[0008] However, during the assembly process, if it is necessary to adjust and hold the position of the sealed case 1051 and the valve housing 1011 using jigs or the like in a welding machine so that the central axis of the sealed case 1051 and the central axis of the valve housing 1011 are on a common central axis in order to ensure high assembly accuracy, then managing the assembly accuracy in the assembly process of the electric valve becomes complicated. Therefore, in the assembly of the sealed case 1051 and the valve housing 1011, it is desired that the axes of the sealed case 1051 and the valve housing 1011 be aligned with high accuracy, and that this can be assembled with simple welding work.

[0009] In consideration of the above problems, the present invention aims to provide an electric valve and a refrigeration cycle system including the same, which have a configuration that allows the housing case and the valve body to be assembled with high precision alignment of their respective axes without requiring complicated assembly precision control. [Means for solving the problem]

[0010] To achieve the above objective, the electric valve according to the present invention includes a valve body housing having a valve chamber that movably houses a valve body unit which includes a valve body that communicates with at least one connection port connected to a fluid pipeline and controls the opening and closing of a valve port of a valve seat provided at the connection port; an electromagnetic actuator including a rotor shaft and a magnetic rotor that operates a drive mechanism which causes the valve body unit to move closer to or further away from the valve port of the valve seat in order to adjust the flow rate of fluid passing between the end of the valve body and the periphery of the valve port of the valve seat; a female thread member which guides the valve body unit and rotatably supports the rotor shaft; and a female thread member which is oriented perpendicular to the central axis of the rotor shaft. The valve comprises a fixing bracket having an outer peripheral edge protruding from the outer periphery of the female thread member, fixed to the female thread member and welded to the periphery of the opening end of the valve body housing into which the lower part of the female thread member is inserted, thereby fixing the female thread member; a housing case housing the rotor shaft and magnet rotor of the electromagnetic actuator, the female thread member, and the fixing bracket, wherein the fixing bracket has a plurality of guide portions formed on its outer peripheral edge so as to be concentric with the central axis of the housing case, each having a contact surface that contacts the inner circumferential surface of the housing case, and a welded portion formed inward in the direction of the central axis of the fixing bracket from the contact surfaces of the guide portions between the guide portions, and welded to the upper surface of the opening end of the valve body housing.

[0011] The contact surface of the guide portion is formed to lie on the circumference of a common virtual circle centered on the central axis of the rotor shaft, and the diameter of the virtual circle may be set to be larger than the outer diameter of the magnet rotor and smaller than the inner diameter of the inner surface of the housing case.

[0012] At least one intersection point may be located on the contact surface of the guide portion where the virtual circle intersects with a line (N=3 or greater) that divides the circumference of the central axis of the fixing bracket into N equal parts at equal angles.

[0013] At least one of the contact surfaces of the multiple guide portions in the fixing bracket may be an arc-shaped surface extending along the inner circumferential surface of the housing case. The welded portion may be welded to the upper surface of the opening end of the valve body housing by multiple spot welds, multiple spaced-apart fillet welds, or continuous fillet welds.

[0014] Furthermore, the electric valve according to the present invention includes a valve body housing having a valve chamber that movably houses a valve body unit which includes a valve body that communicates with at least one connection port connected to a fluid pipeline and controls the opening and closing of a valve port of a valve seat provided at the connection port; an electromagnetic actuator including a rotor shaft and a magnetic rotor that operates a drive mechanism that causes the valve body unit to perform an operation that controls the valve body to move closer to or further away from the valve port of the valve seat in order to adjust the flow rate of fluid passing between the end of the valve body and the periphery of the valve port of the valve seat; a female thread member that guides the valve body unit and rotatably supports the rotor shaft; and an outer peripheral edge having a protruding portion from the outer circumference of the female thread member in a direction perpendicular to the central axis of the rotor shaft, fixed to the female thread member. The electromagnetic actuator comprises a stepped fixing bracket that secures the female thread member by being attached and welded to the upper surface of the opening end of the valve body housing into which the lower part of the female thread member is inserted, a rotor shaft and a magnet rotor of an electromagnetic actuator, a female thread member, and a housing case that houses the fixing bracket, wherein the stepped fixing bracket is formed concentrically with the central axis of the housing case and has a contact surface that contacts the inner circumferential surface of the housing case, and a welded portion formed integrally with the guide portion at a position below the guide portion facing the portion enclosed by the inner circumferential surface of the housing case and the upper surface of the opening end of the valve body housing, and is welded to the upper surface of the opening end of the valve body housing which is closer to the central axis of the rotor shaft than the contact surface of the guide portion. The contact surface of the guide portion is formed to lie on the circumference of a common virtual circle centered on the central axis of the rotor shaft, and the diameter of the virtual circle may be set to be larger than the outer diameter of the magnet rotor and smaller than the inner diameter of the inner circumferential surface of the housing case. If the stepped-edge fixing bracket has multiple guide sections, at least the intersection point of a line (N=3 or greater) that divides the circumference of the fixing bracket's central axis into N equal parts at equal angles, and a virtual circle may be located on the contact surface of each guide section.

[0015] Furthermore, the refrigeration cycle system according to the present invention comprises an evaporator, a compressor, and a condenser, and the above-mentioned electric valve is provided in piping arranged between the outlet of the condenser and the inlet of the evaporator. [Effects of the Invention]

[0016] According to the electric valve and refrigeration cycle system including the present invention, the fixing bracket has a plurality of guide portions formed on the outer peripheral edge so as to be concentric with the central axis of the housing case, each having a contact surface that contacts the inner peripheral surface of the housing case, and a welded portion formed inward in the direction of the central axis of the fixing bracket from the contact surface of the guide portions between the guide portions, and welded to the peripheral edge of the opening end of the valve body housing. As such, the housing case and the valve body housing can be assembled with high precision, without requiring complicated assembly accuracy control. [Brief explanation of the drawing]

[0017] [Figure 1] This is a longitudinal cross-sectional view showing the schematic configuration of a first embodiment of the electric valve according to the present invention. [Figure 2] Figure 2(a) is a cross-sectional view along the line IIA-IIA shown in Figure 1, illustrating the shape of the fixing bracket; Figure 2(b) is a magnified view of the IIB portion of Figure 2(a); and Figure 2(c) is a diagram illustrating the guide portion of the fixing bracket shown in Figure 2(a). [Figure 3] Figure 3(a) shows a second embodiment of the fixing bracket, Figure 3(b) shows a third embodiment of the fixing bracket, and Figure 3(c) shows a fourth embodiment of the fixing bracket. [Figure 4] This is a longitudinal cross-sectional view showing the schematic configuration of a second embodiment of the electric valve according to the present invention. [Figure 5] This is an enlarged cross-sectional view showing a magnified view of the V portion shown in Figure 4. [Figure 6] This figure shows an example of the configuration of a refrigeration cycle system using an example of an electric valve according to the present invention. [Figure 7] This figure shows a modified example of a fixing bracket used in an example of an electric valve according to the present invention. [Figure 8]FIG. 8(a) is a partial cross-sectional view showing a partially enlarged joint structure of a sealing case, a valve body, and a fixing fitting of an electric valve in a prior art document, and FIG. 8(b) is a partial cross-sectional view of the sealing case, the valve body, and the fixing fitting shown in FIG. 8(a). [Figure 9] FIG. 9(a) is a partial cross-sectional view showing a partially enlarged another example of a joint structure of a sealing case, a valve body, and a fixing fitting of an electric valve in a prior art document, and FIG. 9(b) is an enlarged cross-sectional view showing an enlarged IXB portion shown in FIG. 9(a).

MODE FOR CARRYING OUT THE INVENTION

[0018] FIG. 1 schematically shows the configuration of a first embodiment of an electric valve according to the present invention together with a piping pipe.

[0019] In the following description, the concepts of up and down correspond to, for example, up and down in FIG. 1, and show the relative positional relationship between the members, not the absolute positional relationship.

[0020] The electric valve 100 as the first embodiment and the electric valve 200 (see FIG. 4) as the second embodiment described later are arranged, for example, as shown in FIG. 6, between the outlet (the first port 312a) of the outdoor heat exchanger 312 and the inlet (the first port 315a) of the indoor heat exchanger 315 during the cooling operation described later in the piping of the refrigeration cycle system 300 as the expansion valve 311.

[0021] During cooling operation, the expansion valve 311 is connected to the primary side piping Du1 by a connecting pipe (second joint 12), which will be described later, and is connected to the secondary side piping Du2 by a connecting pipe (first joint 11). The primary side piping Du1 connects the outlet (first port 312a) of the outdoor heat exchanger 312 to the expansion valve 311, and the secondary side piping Du2 connects the inlet (first port 315a) of the indoor heat exchanger 315 to the expansion valve 311. Between the outlet (second port 315b) of the indoor heat exchanger 315 and the inlet (second port 312b) of the outdoor heat exchanger 312, there is a pipe Du3 connected to the outlet of the indoor heat exchanger 315, a flow path switching valve 313, and a pipe Du6 connected to the inlet of the outdoor heat exchanger 312. Furthermore, the compressor 314 is connected to the flow path switching valve 313 by pipes Du4 and Du5. The other end of pipe Du3 is connected to port 313d of the flow path switching valve 313. The other end of pipe Du6 is connected to port 313b of the flow path switching valve 313. One end of pipe Du4 is connected to port 313c of the flow path switching valve 313, and the other end of pipe Du4 is connected to the discharge port of the compressor 314. One end of pipe Du5 is connected to port 313a of the flow path switching valve 313, and the other end of pipe Du5 is connected to the intake port of the compressor 314. During cooling operation, ports 313a and 313d are in communication, and ports 313b and 313c are in communication. As a result, during cooling operation, the refrigerant in the refrigeration cycle system circulates, for example, along the direction indicated by the dashed arrow shown in Figure 6, with the outdoor heat exchanger 312 functioning as a condenser and the indoor heat exchanger 315 functioning as an evaporator. In addition, although the configuration described above shows the expansion valve 311 connected to the primary side piping Du1 by the second joint 12 and connected to the secondary side piping Du2 by the first joint 11 during cooling operation, the configuration is not limited to this example. For example, during cooling operation, the expansion valve 311 may be connected to the primary side piping Du1 by the first joint 11 and connected to the secondary side piping Du2 by the second joint 12.

[0022] On the other hand, during heating operation, the flow path switching valve 313 is switched so that ports 313a and 313b of the flow path switching valve 314 are in communication, and ports 313c and 313d are in communication. As a result, during heating operation, the refrigerant in the refrigeration cycle system is circulated, for example, in the direction indicated by the solid arrow shown in Figure 6, with the indoor heat exchanger 315 functioning as a condenser and the outdoor heat exchanger 312 functioning as an evaporator. The compressor 314 and expansion valve 311 are driven and controlled by a control unit (not shown), and the flow path switching valve 313 is switched.

[0023] As shown in Figure 1, the electric valve 100 is composed of a valve drive unit which is disposed within a cylindrical housing case 151 which constitutes part of the exterior part 150 described later and drives the valve body unit which will be described later to move up and down; a valve body part 110 which is connected to the lower end of the housing case 151 and has a valve seat 112 which has a valve port 112a that is opened and closed at the tip of a needle 121 which serves as a valve body; and a valve body unit which is disposed within the valve body part 110 and includes a needle 121 that opens and closes the valve port 112a of the valve seat 112.

[0024] The valve drive unit mainly consists of a rotor shaft 131 that moves the valve body unit (described later) up and down, a female threaded member 132 having a female thread formed on a male threaded portion 132a that fits concentrically with the male threaded portion 131a of the rotor shaft 131, and fixed to the valve body housing 111 as a guide support that guides the valve body unit so that it can move up and down, a magnet rotor 141 that is fixed concentrically to the guide shaft portion of the rotor shaft 131, is rotatably supported and magnetized, and a stator coil (not shown) arranged on the outer circumference of the housing case 151 that rotates the magnet rotor 141. The magnet rotor 141 and the stator coil constitute part of a stepping motor that acts as an electromagnetic actuator.

[0025] The rotor shaft 131 and the female threaded member 132 form part of the rotor shaft rotation section 130, which will be described later. The magnet rotor 141 and the stator coil also constitute part of the rotor shaft drive section 140, which will be described later.

[0026] The valve body housing 111 of the valve body portion 110 is formed by processing a metal material such as a stainless steel plate into a cylindrical shape by press working or the like. The valve body housing 111 has a valve chamber 111A that houses the lower end (protruding portion 132B) of the female thread member 132, the other end of the needle 121 which is supported concentrically with the rotor shaft 131 described later, and a cylindrical needle case 125. The other end of the needle 121 protrudes into the valve chamber 111A toward the valve port 112a. Furthermore, the valve chamber 111A has a first port 111b to which one end of the first joint 11 serving as a first passage is connected on an axis substantially perpendicular to the central axis of the needle 121, and a valve seat 112 having a valve port 112a adjacent to the second port 111c to which one end of the second joint 12 serving as a second passage is connected on an axis common with the central axis of the needle 121.

[0027] The periphery of the circular opening end at the top of the valve body housing 111 has an upper surface of the opening end, i.e., an annular joint portion 111d, which is joined to the lower end of the housing case 151, described later.

[0028] The first joint 11 and the second joint 12 are both made of copper or stainless steel and are fixed to the valve body housing 111 by brazing or welding, but are not limited to these. In addition, in this embodiment, the electric valve is described as having the first port 111b as the inlet side and the second port 111c as the outlet side through which the refrigerant flows, but is not limited to this, and the electric valve 100 of this embodiment is a bidirectional electric valve that can also be used with the first port 111b as the outlet side and the second port 111c as the inlet side.

[0029] The valve seat 112 is formed from a metal material such as stainless steel or a copper alloy, and is fixed around the second port 111c to which the second joint 12 of the valve body housing 111 is connected by welding or brazing. The needle 121, along with the needle case 125, is positioned to be close to or away from the valve port 112a, thereby controlling the flow rate of refrigerant passing through the valve port 112a. Here, the valve seat 112 is a separate component from the valve body housing 111, but it may also be molded integrally with the valve body housing 111.

[0030] The valve body unit 120 mainly consists of a needle 121 that opens and closes the valve port 112a of the valve seat 112, a cylindrical resin spring retainer 123 that engages the flange portion 131b of the rotor shaft 131 with the inner periphery of the open end 125a of the needle case 125 in cooperation with a resin washer 124, a valve spring 122 that is positioned between the spring engagement portion 123a of the spring retainer 123 and the annular flat portion for spring retention at one end of the needle 121 and biases them in a direction that separates them from each other, and a cylindrical needle case 125 that houses the spring retainer 123, the valve spring 122, and one end of the needle 121.

[0031] The needle 121 is made of a metal material such as stainless steel. The needle 121 is raised and lowered along the central axis CL by a rotor shaft 131, which will be described later. This controls the flow rate of the refrigerant passing through the valve port 112a. The side of the needle 121 that is close to the valve port 112a has a shape that protrudes gently in the center. This protruding shape is formed so that the effective opening area increases or decreases depending on the position of the needle 121, through the position control of the needle 121 relative to the valve port 112a as described above.

[0032] The valve spring 122, positioned inside the roughly cylindrical needle case 125, is compressed and positioned between the needle 121 and the spring engagement portion 123a of the spring retainer 123, which will be described later. The valve spring 122 prevents the screw thrust from the rotor shaft 131, etc., which will be described later, from being directly applied to the needle 121 and the valve port 112a, and as a result, enhances the durability of the electric valve 100.

[0033] The spring retainer 123 is formed in a substantially cylindrical shape, for example, from resin. The spring retainer 123 is located inside the needle case 125, between the flange portion 131b of the rotor shaft 131 (described later) and the needle 121, and is positioned inside the valve spring 122 along the central axis CL. A disc-shaped spring engagement portion 123a protruding outward is formed at the end of the spring retainer 123 that contacts the rotor shaft 131. By positioning the spring retainer 123 inside the valve spring 122 along the central axis CL, the concentricity between the valve spring 122 and the spring retainer 123 is increased, which has the effect of improving the operability of the valve body unit 120.

[0034] The washer 124 is formed in an annular shape from, for example, a highly slippery resin. The washer 124 is positioned between the flange portion 131b of the rotor shaft 131 (described later) and the open end portion 125a of the needle case 125 (described later). By providing the washer 124, it is possible to suppress the direct transmission of the rotation of the rotor shaft 131 to the needle 121. This suppresses the rotation of the needle 121 and has the effect of preventing wear between the needle 121 and the valve port 112a of the valve seat 112.

[0035] The needle case 125 is made of a metal material such as stainless steel and is formed into a substantially cylindrical shape by press working or the like. An open end 125a is formed at the end of the needle case 125 that faces the rotor shaft 131. The needle case 125 has the function of transmitting the screw driving force of the rotor shaft 131, etc., which will be described later, to the needle 121. The open end 125a of the needle case 125 is positioned to engage with the flange portion 131b of the rotor shaft 131 which is opposite to it. The needle 121 is fixed to the end of the needle case 125 opposite to the open end 125a by welding or the like.

[0036] The rotor shaft drive unit 140 includes a magnetic rotor 141, a rotor fixing member 142, a rotation stopper spring 143, and a movable stopper member 144.

[0037] The magnet rotor 141 is housed in a rotor chamber 141A inside a housing case 151 (described later) and is composed of multi-pole permanent magnets made of ferrite sintered material or the like, arranged alternately with north and south poles. In this embodiment, the magnet rotor 141 is arranged on the outer circumference of the housing case 151 (described later) and, together with a stator coil consisting of a yoke, bobbin, and coil (not shown), constitutes a stepping motor. Although a stepping motor is used here, it is not limited to this, and similar effects can be obtained by using other electric motors capable of rotating the magnet rotor 141.

[0038] The magnetic rotor 141 is supported on the rotor shaft 131 via a rotor fixing member 142. The rotor fixing member 142, which has a hole into which the rotor shaft 131 is inserted, is positioned around the central axis of the rotor shaft 131. The rotor fixing member 142 is press-fitted into the mounting hole of the magnetic rotor 141.

[0039] The rotation stopper spring 143 has a coil spring shape and is wound around the cylindrical portion 152b of the rotor support member 152, which will be described later. The upper and lower ends of the rotation stopper spring 143 are locked to the cylindrical portion 152b, respectively.

[0040] The movable stopper member 144 has a coil spring shape with approximately one turn and is rotatably positioned around the cylindrical portion 152b of the rotor support member 152. One end of the movable stopper member 144 engages with an engaging projection 141b integrally formed on a predetermined pole of the multi-pole magnet rotor 141, and the other end is screwed onto the rotation stopper spring 143. The movable stopper member 144 moves up and down while rotating around the cylindrical portion 152b in accordance with the rotation of the magnet rotor 141. With this configuration, the rotation stopper spring 143 is positioned without play with respect to the central axis CL of the electric valve 100.

[0041] The exterior section 150 comprises a housing case 151, a rotor support member 152, and a cylindrical member 153.

[0042] The housing case 151 is formed from a non-magnetic metal material, such as a stainless steel plate, by press working or the like to create a cup shape. The housing case 151 has an outer diameter that is approximately the same as the outer diameter of the valve body housing 111 described above. The circular lower end of the housing case 151 is fixed to the circular upper end of the valve body housing 111 by butt welding around the entire circumference, for example by TIG welding, plasma welding, laser welding, or resistance welding. This creates a sealed state inside the housing case 151. The housing case 151 also has dimples 151a formed therein for engaging with the engagement recesses 152c formed in the cup-shaped portion 152a of the rotor support member 152, which will be described later.

[0043] The rotor support member 152 is formed from a material such as stainless steel sheet by press working or the like. The rotor support member 152 consists of a cup-shaped portion 152a that contacts and is fixed to the housing case 151, and a cylindrical portion 152b that extends downward from the center of the cup-shaped portion 152a. An engaging recess 152c is formed in the cup-shaped portion 152a. The rotor support member 152 is fixed to a predetermined mounting position on the housing case 151 by the engagement of this engaging recess 152c with the dimples 151a of the housing case 151.

[0044] The cylindrical member 153 is made of a highly lubricating material, such as metal or synthetic resin. The cylindrical member 153 is positioned inside the cylindrical portion 152b of the rotor support member 152 and rotatably holds the upper end (guide shaft portion) of the rotor shaft 131.

[0045] The rotor shaft rotating section 130 comprises a rotor shaft 131, a female threaded member 132, and a fixing bracket 133.

[0046] The rotor shaft 131 is made of, for example, a metal material, is generally cylindrical in shape, and extends vertically along the central axis CL of the electric valve 100. The magnet rotor 141, which is rotated by an electric motor such as a stepping motor (described later), is fixed to the rotor shaft 131 around its axis via a rotor fixing member 142 (described later). As a result, the rotor shaft 131 rotates around the central axis CL together with the magnet rotor 141.

[0047] A male threaded portion 131a is formed on the part of the rotor shaft 131 that is closer to the needle 121 than the rotor fixing member 142. The male threaded portion 131a is screwed into the female threaded portion 132b of the female threaded member 132, which will be described later. Furthermore, a flanged portion 131b is formed on the end of the rotor shaft 131 that is closer to the needle 121 than the male threaded portion 131a, projecting outward in a disc shape. The flanged portion 131b is positioned at a distance from the inner circumferential surface of the open end 125a of the needle case 125. The diameter of the flanged portion 131b is larger than the diameter of the hole in the open end 125a, thus preventing it from coming loose.

[0048] The female threaded member 132 is formed in a generally cylindrical shape, for example, from resin. The upper part of the female threaded member 132 has a female threaded portion 132b which fits onto the male threaded portion 131a of the rotor shaft 131. The female threaded portion 132b is formed concentrically with the central axis CL of the electric valve 100. The female threaded member 132, through its screw connection with the rotor shaft 131, constitutes part of a screw feed mechanism that converts the rotational motion of the magnet rotor 141 into linear motion in the direction of the central axis CL of the rotor shaft 131.

[0049] A guide chamber 132A is formed in the female thread member 132 below the female thread portion 132b, which slidably accommodates the needle case 125 along with the needle 121. The inner circumferential surface of the female thread member 132 forming the guide chamber 132A serves as a guide surface that movably guides the outer circumferential surface of the cylindrical needle case 125. In addition, a pressure equalization hole 132c that penetrates to the outside is provided in a part of the inner circumferential surface forming the guide chamber 132A. This allows the guide chamber 132A and the rotor chamber 141A to communicate, facilitating the movement of the rotor shaft 131 and the needle case 125. Furthermore, a protruding portion 132B is formed at the end of the female thread member 132 below the portion in which the pressure equalization hole 132c is formed, which is inserted into the open end of the valve body housing 111. A fixing bracket 133 is fixed to the protruding portion 132B by insert molding. In this configuration, the fixing bracket 133 is fixed concentrically with the central axis of the female screw member 132.

[0050] The fixing bracket 133 is, for example, a metal disc-shaped member as shown in Figure 2(a). The arcuate or inclined surface of the recess 133b on the outer circumference of the fixing bracket 133, which will be described later, is fixed to the annular joint 111d of the valve body housing 111 by welding or the like. As a result, the female thread member 132 is fixed to the valve body housing 111 via the fixing bracket 133. At that time, the female thread member 132 is fixed concentrically with the central axis of the valve body housing 111.

[0051] The electric valve 100 of the first embodiment of the present invention, as described above, is provided with a structure that automatically maintains coaxiality between the housing case 151 and the female threaded member 132 by using the above-mentioned simple-shaped fixing bracket 133 in order to solve the problems of the conventional invention. The structure will be described below with reference to Figures 2(a) and 2(b).

[0052] Figure 2(a) is a cross-sectional view along the line IIA-IIA shown in Figure 1, showing the shape of the fixing bracket 133; Figure 2(b) is a magnified view of the IIB portion of Figure 2(a); and Figure 2(c) is a diagram illustrating the guide portion 133c (hereinafter also referred to as the protruding portion 133a) of the fixing bracket 133 shown in Figure 2(a).

[0053] As shown in Figures 2(a) and 2(b), the fixing bracket 133 as the first embodiment is, for example, a metal member with a roughly disc shape, and four protrusions 133a are provided along the outer circumference of the disc shape. Each protrusion 133a has a contact surface that projects radially so as to abut against the inner circumferential surface of the housing case 151. The shape of the four protrusions 133a is generally formed in an arc shape so that the tip abuts against the inner circumferential surface 151b of the cup-shaped housing case 151. Note that the contact surface is not limited to surface contact only; for example, a portion of the contact surface may be configured to be in line contact or point contact.

[0054] The four protrusions 133a are formed along the circumferential direction of the fixing bracket 133 at equal angle (90°) intervals. Each protrusion 133a is also formed with the same width W along the circumferential direction. Four recesses 133b are formed between the consecutive protrusions 133a. Each recess 133b is formed from an arcuate surface portion extending in the circumferential direction of the fixing bracket 133 and inclined surfaces extending from both ends of the arcuate surface portion to the contact surface of the guide portion 133c. The radius of curvature of the outer surface forming the arcuate portion of the recess 133b is set to be smaller than the radius of curvature of the contact surface forming the protrusions 133a.

[0055] In this case, the recess 133b is provided on the outer circumference of the multiple protrusions 133a, in a portion other than the protrusions 133a.

[0056] In this case, the recess 133b is formed from an arcuate surface portion extending in the circumferential direction of the fixing bracket 133 and slanted surfaces connected to both ends of the arcuate surface portion and reaching the contact surface of the guide portion 133c. In the recess 133b, for example, if the entire arcuate surface portion is fillet welded and the slanted surfaces are not welded, the welded arcuate surface portion will form the welded portion 133d. Also, for example, if the arcuate surface portion is welded at predetermined intervals by multiple spot welds and the slanted surfaces are not welded, each spot-welded portion will form the welded portion 133d. Furthermore, if only the two aforementioned slanted surfaces are spot-welded or fillet-welded and the arcuate surface portion is not welded, the spot-welded or fillet-welded portions will form the welded portion 133d. Unwelded arcuate surface portions or slanted surfaces, in other words, arcuate surface portions or slanted surfaces that do not need to be welded, may become welded areas, as shown in Figure 2(b).

[0057] In this example, all of the contact surfaces of the four protrusions 133a are in contact with the inner circumferential surface 151b of the housing case 151. However, this is not necessarily required. For example, all of the contact surfaces of the four protrusions 133a (guide portion 133c) do not need to be in contact with the inner circumferential surface 151b of the housing case 151.

[0058] The guide portion 133c (protrusion 133a) will be described in more detail with reference to Figures 2(a) and 2(c). The contact surface of each guide portion 133c is formed to lie on the circumference of a common virtual circle CI centered on the central axis CL of the rotor shaft 131. The radius of the virtual circle CI is set, for example, to the length from the central axis CL of the fixing bracket 133, which is concentric with the rotor shaft 131, to the part furthest from it. As a result, during assembly, the fixing bracket 133 is fitted into the inner circumferential surface 151b of the housing case 151. The guide portion 133c only needs to maintain coaxiality (concentricity, degree of coaxiality) between the housing case 151 and the female screw member 132 to the extent that interference between the inner circumferential surface 151b of the housing case 151 and the rotating magnet rotor 141 is prevented. Therefore, the diameter of the virtual circle CI on the contact surface of the guide portion 133c is set to be larger than the outer diameter of the magnet rotor 141 and smaller than the inner diameter of the inner circumferential surface 151b of the housing case 151 (outer diameter of magnet rotor 141 < diameter of virtual circle CI < inner diameter of housing case 151). Furthermore, as shown in Figure 2(c), it is desirable that the contact surface of the guide portion 133c that contacts the inner circumferential surface 151b of the housing case 151 has an intersection point where the lines that divide the circumference of the central axis CL of the fixing bracket 133 into four equal parts at equal angles intersect with the virtual circle CI. Although four equal parts are used here, the above coaxiality can be maintained by dividing it into N equal parts (where N is an integer of 3 or more).

[0059] When the arcuate or slanted surfaces of the four recesses 133b are welded to the joint 111d of the valve body housing 111, the welding is only required at the welded portion 133d, which is located in a part other than the guide portion 133c described above. As described above, the recess 133b is formed from an arcuate surface extending in the circumferential direction of the fixing fitting 133 and slanted surfaces that are connected to both ends of the arcuate surface and reach the contact surface of the guide portion 133c. For example, as shown in Figure 2(b), the welded arcuate or slanted surface is the welded portion 133d in the area including not only the arcuate surface but also the slanted surface in Figure 2(a), which is the part closest to the central axis CL that forms the recess 133b. As a result, the bead formed in the welded portion 133d is not outside the virtual circle CI but is formed in the area inside the virtual circle CI, so there is no risk of the bead interfering with the inner circumferential surface 151b of the housing case 151.

[0060] Furthermore, as shown by the dashed line in Figure 2(a), the welded portion 133d cannot be positioned inside the inner diameter of the annular joint portion 111d of the valve body housing 111. This is because the fixing bracket 133 and the valve body housing 111 cannot come into contact, making welding and fixing impossible.

[0061] In this configuration, when assembling the electric valve 100 described above, first, the rotor shaft 131 and the needle case 125 to which the needle 121 is fixed are attached to the female thread member 132. Next, the protruding portion 132B of the female thread member 132 is inserted into the open end of the valve body housing 111, and the fixing bracket 133 is placed on the periphery of the open end of the valve body housing 111, to which the valve seat 112 etc. are pre-attached. Subsequently, for example, the arcuate surface portion of the recess 133b of the fixing bracket 133 and the periphery of the open end of the valve body housing 111 are fixed by fillet welding using a first welding machine (not shown). As a result, a first bead is formed between the welded portion 133d, which is the welded arcuate surface portion, and the joint portion 111d of the valve body housing 111.

[0062] Furthermore, the radial gap between the protruding portion 132B of the female threaded member 132 and the open end of the valve body housing 111 may be set to be, for example, a clearance fit or an interference fit.

[0063] Next, after the magnet rotor 141 is attached to the rotor shaft 131, the valve body housing 111 is removed from the first welding machine, and the assembled valve body housing 111 is transferred to the support stand (not shown) of the second welding machine. Then, the lower end of the housing case 151 is placed without gaps on the periphery of the open end of the valve body housing 111 so that the inner circumferential surface 151b of the housing case 151, to which the rotor support member 152 etc. are attached, contacts the contact surface of the guide portion 133c of the fixing bracket 133 at the periphery of the open end of the valve body housing 111 to which the welded portion 133d of the fixing bracket 133 is fixed. As a result, the axis of the housing case 151 and the axes of the rotor shaft 131 and the female thread member 132 automatically align.

[0064] Then, on the support base of the second welding machine, the housing case 151 and the valve body housing 111, which have substantially the same outer diameter, are gripped as a whole, and with the axes of the housing case 151 and the valve body housing 111 aligned, welding is performed on the lower end surface of the housing case 151 and the joint portion 111d of the valve body housing 111. As a result, a second bead is formed on the joint portion 111d of the lower end surface of the housing case 151 and the valve body housing 111, adjacent to the first bead described above.

[0065] In this way, by providing multiple guide portions 133c (protrusions 133a) and multiple recesses 133b on the outer circumference of the fixing bracket 133, for example, a disc shape, the contact surfaces of the guide portions 133c come into contact with the inner circumferential surface 151b of the housing case 151, and the fixing bracket 133 and the valve body housing 111 can be welded and fixed by the welded portions 133d formed in the recesses 133b that do not come into contact with the inner circumferential surface 151b of the housing case 151. Since the weld beads formed in the welded portions 133d do not interfere with the inner circumferential surface 151b of the housing case 151, the valve body housing 111 and the housing case 151 can come into contact with each other without any gaps and be fixed while maintaining coaxiality.

[0066] In the above example, it is not necessary for all the contact surfaces of the guide portions 133c to contact the inner surface of the housing case 151. The end of the housing case 151 and the end of the valve body housing 111 may be brought into close contact with the end of the housing case 151 while the contact surfaces of all the guide portions 133c do not contact the inner surface of the housing case 151, thereby maintaining the coaxiality between the fixing bracket 133 and the housing case 151. This is because the contact surfaces of the guide portions 133c act as mechanical stoppers to prevent the amount of axial misalignment between the housing case 151 and the valve body housing 111 from moving from a range where the magnet rotor 141 does not contact the inner circumferential surface 151b of the housing case 151 to a range where it does contact the inner circumferential surface 151b of the housing case 151 during rotation, thereby preventing the housing case 151 from shifting.

[0067] In this example, four protrusions 133a (guide portions 133c) formed on the fixing bracket 133 are provided, but as long as coaxiality with the housing case 151 is maintained, it is sufficient to provide them in two or more locations as long as the above conditions are met. The second to fourth embodiments (modified versions) of the fixing bracket will be described below with reference to Figures 3(a) to 3(c).

[0068] Figure 3(a) shows another example of the shape of the fixing bracket, Figure 3(b) shows yet another example of the shape of the fixing bracket, and Figure 3(c) shows yet another example of the shape of the fixing bracket.

[0069] As shown in Figure 3(a), the fixing bracket 133A as the second embodiment has three protrusions 133Aa (hereinafter also referred to as guide portions 133Ac), and three recesses 133Ab are formed between the circumferential protrusions 133Aa. The three protrusions 133Aa are formed at equal angular intervals, for example, 120° intervals. The width W of each protrusion 133Aa along the circumferential direction is set to be the same as one another. The recesses 133Ab are also formed at equal angular intervals, for example, 120° intervals. The length of the arcuate surface portion forming the recesses 133Ab along the circumferential direction is set to be the same as one another. Furthermore, as shown in Figure 3(a), the contact surface of the guide portion 133Ac that abuts the inner circumferential surface of the housing case 151 is located at the intersection of a line that divides the circumference of the central axis CL of the fixing bracket 133A into three equal angles and a virtual circle (a common circle on which each of the aforementioned contact surfaces exists, similar to the virtual circle shown in Figure 2(c)). This satisfies the conditions for maintaining the coaxiality described above.

[0070] In this case, the recess 133Ab is formed from an arcuate surface portion extending in the circumferential direction of the fixing bracket 133 and inclined surfaces that are connected to both ends of the arcuate surface portion and reach the contact surface of the guide portion 133Aa. In the recess 133Ab, for example, if the entire arcuate surface portion is fillet welded and the inclined surfaces are not welded, the welded arcuate surface portion will form the welded portion 133Ad.

[0071] Furthermore, as shown in Figure 3(b), the fixing bracket 133B as the third embodiment is provided with a narrow protrusion 133Ba1 (hereinafter also referred to as the guide portion 133Bc) and a protrusion 133Ba2 consisting of an arcuate surface portion having a central angle of approximately 120° along the circumferential direction, positioned opposite each other. Between the two protrusions 133Ba1 and 133Ba2, there are two recesses 133Bb, each containing an arcuate surface portion formed along the circumferential direction. The circumferential lengths (surface areas) of the contact surfaces of the two protrusions 133Ba1 and the contact surface of the protrusion 133Ba2 are different and not equal. Furthermore, as shown in Figure 3(b), the contact surface of the guide portion 133Bc that abuts the inner circumferential surface 151b of the housing case 151 is located at the intersection of a line that divides the circumference of the central axis CL of the fixing bracket 133B into three equal angles and a virtual circle (a common circle where the aforementioned contact surfaces exist, similar to the virtual circle shown in Figure 2(c)). This satisfies the conditions for maintaining the aforementioned coaxiality.

[0072] In this case, the recess 133Bb is formed from an arcuate surface portion extending in the circumferential direction of the fixing bracket 133 and inclined surfaces connected to both ends of the arcuate surface portion and reaching the contact surface of the guide portion 133Bc. In the recess 133Bb, for example, if the entire arcuate surface portion is fillet welded and the inclined surfaces are not welded, the welded arcuate surface portion will form the welded portion 133Bd.

[0073] Furthermore, as shown in Figure 3(c), in the fixing bracket 133C as the fourth embodiment, two recesses 133Cb are formed opposite each other on the remaining portion other than the two opposing protrusions 133Ca (hereinafter also referred to as guide portion 133Cc). The contact surfaces of the two protrusions 133Ca are formed by arcuate surfaces having the same central angle. The outer circumferential surfaces forming the two recesses 133Cb are formed from curved surfaces having the same shape. Also, as shown in Figure 3(c), the contact surface of the guide portion 133Cc that contacts the inner circumferential surface 151b of the housing case 151 is located at the intersection of a line that divides the circumference of the central axis CL of the fixing bracket 133C into four equal parts at equal angles and a virtual circle. This satisfies the conditions for maintaining coaxiality.

[0074] In this case, the recess 133Cb is formed from a curved surface portion extending in the circumferential direction of the fixing bracket 133 and slanted surfaces connected to both ends of the curved surface portion and reaching the contact surface of the guide portion 133Ca. In the recess 133Cb, for example, if the entire curved surface portion is fillet welded and the slanted surfaces are not welded, the welded curved surface portion will form the welded portion 133Cd.

[0075] By using the second to fourth embodiments (modified versions) of the fixing bracket 133, such as fixing brackets 133A, 133B, and 133C, the valve body housing 111 and the housing case 151 will be in contact with each other without any gaps, just as when using the fixing bracket 133 shown in Figure 2(a), and coaxiality will be maintained.

[0076] As described above, according to the electric valve 100 of the first embodiment of the present invention, by providing a plurality of guide portions 133c and a plurality of welded portions 133d along the outer circumference of the fixing bracket 133, interference between the weld bead that may occur at the welded portion and the housing case 151 can be prevented, the valve body housing 111 and the housing case 151 can be fixed in contact with each other without gaps, maintaining coaxiality, and reducing manufacturing control requirements.

[0077] The operation of the electric valve 100 configured in this way will be explained.

[0078] When driving the electric valve 100, the process begins by supplying a drive pulse signal to the stator. This causes the magnet rotor 141 to rotate according to the number of pulses, and consequently the rotor shaft 131 to rotate. The screw connection between the male threaded portion 131a of the rotor shaft 131 and the female threaded portion 132b of the female threaded member 132 causes the rotor shaft 131 to rotate and move along the central axis CL.

[0079] To close the electric valve 100, the rotor shaft 131 must be moved downward. After the needle 121 contacts the valve seat 112, when the rotor shaft 131 moves further downward, the valve spring 122 compresses via the spring retainer 123, and the needle 121 is pressed against the valve seat 112 by the load from the reaction force of the valve spring 122, thereby controlling the electric valve 100 to a securely closed state.

[0080] At this time, the needle 121 is pressed against the valve seat 112 via the spring retainer 123 and the valve spring 122, so the frictional resistance of the seating surface becomes greater than the frictional resistance between the rotor shaft 131 and the highly slippery spring retainer 123. As a result, the rotating rotor shaft 131 slides between itself and the spring retainer 123, suppressing the transmission of rotation to the needle case 125 and the needle 121. This suppresses wear between the needle 121 and the valve port 112a. In addition, as the rotor shaft 131 is pushed in, the washer 124 descends together with the flange portion 131b of the rotor shaft 131, so the upper surface of the washer 124 does not come into contact with the lower end surface of the opening end 125a of the needle case 125, and the rotation of the needle case 125 also stops.

[0081] Next, to return the electric valve 100 from the closed state to the open state, it is necessary to rotate the rotor shaft 131 in the reverse direction and move it upward. As the rotor shaft 131 rises, the valve spring 122 extends via the spring retainer 123. At this time, the needle 121 maintains contact with the valve seat 112. As the rotor shaft 131 moves further upward, the flange portion 131b of the rotor shaft 131 contacts the inner surface of the open end 125a of the needle case 125 via the washer 124, and the needle case 125 is lifted while rotating. When the needle case 125 is lifted, the needle 121 fixed to it also moves upward, and the needle 121 and the valve port 112a of the valve seat 112 become non-contact, and the electric valve 100 is controlled to the open state.

[0082] In this case, the needle case 125 and needle 121 are driven by the rotor shaft 131 via a highly slippery washer 124, thereby suppressing the transmission of the rotation of the rotor shaft 131 to the needle case 125 and needle 121. This suppresses wear between the needle 121 and the valve port 112a.

[0083] Next, a second embodiment of the electric valve according to the present invention will be described.

[0084] Figure 4 schematically shows the configuration of a second embodiment of the electric valve according to the present invention, along with the piping. Figure 5 is an enlarged cross-sectional view showing a magnified view of the V portion shown in Figure 4.

[0085] As shown in Figures 4 and 5, the configuration of the electric valve 200 differs from that of the electric valve 100, which has a fixing bracket 133, in that it includes a stepped fixing bracket 233 that is insert-molded into the female thread member 233. More specifically, the outer circumference of the metal, roughly disc-shaped stepped fixing bracket 233 has a contact surface that abuts against the inner circumferential surface 151b of the housing case 151 and has a stepped portion consisting of a convex portion 233a (hereinafter also referred to as a guide portion 233c) that protrudes outward and a recess 233b that forms a gap in the portion surrounded by the inner circumferential surface 151b of the housing case 151 and the upper end surface of the valve body housing 111. A part of the upper end surface of the valve body housing 111 that forms the recess 233b (joint portion 111d) and a part of the lower end of the stepped fixing bracket 233 that is supported by the upper end surface of the valve body housing 111 form a welded portion 233d, as shown in Figure 5.

[0086] Furthermore, since the other components of the electric valve 200 are the same as those of the electric valve 100 described above, the same reference numerals are used for the same components, and their redundant explanations are omitted.

[0087] As shown in Figures 4 and 5, the stepped portion of the stepped fixing bracket 233 described above is formed in the thickness direction along the central axis CL of the electric valve 200. The recessed portion 233b, which is close to the central axis CL, is formed on the valve body housing 111 side, which is the lower side of the fixing bracket 233, because the lower end surface of the fixing bracket 233 is fillet welded to the joint portion 111d of the valve body housing 111. The contact surface of the guide portion 233c, which is further from the central axis CL than the recessed portion 233b, contacts the inner circumferential surface 151b of the housing case 151, so it is formed on the housing case 151 side, which is the upper side of the fixing bracket 233.

[0088] In this case, it is not necessarily required that the entire contact surface of the protrusion 233a contacts the inner circumferential surface 151b of the housing case 151.

[0089] The condition for the guide portion 233c is the same as in the first embodiment, in which the stepped fixing bracket 233 is fitted onto the inner circumferential surface 151b of the housing case 151 so that the contact surface of the guide portion 233c contacts the inner circumferential surface 151b of the housing case 151. The guide portion 233c only needs to maintain coaxiality (coaxiality, concentricity) between the housing case 151 and the valve body housing 111 to the extent that interference between the inner circumferential surface of the housing case 151 and the rotating magnet rotor 141 is prevented. For this reason, the diameter of the contact surface of the guide portion 233c is set to be larger than the outer diameter of the magnet rotor 141 and smaller than the inner diameter of the inner circumferential surface 151b of the housing case 151 (outer diameter of magnet rotor 141 < diameter of contact surface < inner diameter of housing case 151).

[0090] Furthermore, the lower end portion that forms part of the recess 233b, which is the part other than the guide portion 233c mentioned above, and the joint portion 111d of the valve body housing 111 are welded together. As a result, the welded portion 233d is formed by the lower end portion that forms the recess 233b of the stepped edge fixing bracket 233 and the joint portion 111d of the valve body housing 111.

[0091] It is not necessary for the entire recess 233b to be welded to the welded portion 233d; a portion of the recess 233b may be welded, or it may be fixed by welding using multiple spot welds or multiple spot fillet welds.

[0092] Furthermore, the welded portion 233d cannot be located inside the inner diameter of the annular joint portion 111d of the valve body housing 111. This is because the fixing bracket 233 and the valve body housing 111 cannot come into contact, making welding and fixing impossible. In addition, the welded portion 233d must be formed in a position where the weld bead 233w generated by welding with the valve body housing 111 does not interfere with the housing case 151.

[0093] Furthermore, the protrusions 233a may be provided continuously around the entire circumference, or they may not be continuous around the entire circumference and may be interrupted in multiple parts. In such cases, the contact surface of the guide portion 233c shall have at least one intersection point where a line (N=3 or greater) that divides the circumference of the central axis of the fixing bracket into N equal parts at equal angles intersects with a virtual circle similar to the virtual circle shown in Figure 2(c).

[0094] However, if the protrusion 233a is provided around the entire circumference, the protrusion 233a becomes circular, which makes manufacturing easier and thus reduces the number of manufacturing steps.

[0095] Furthermore, this embodiment can also be taken in the following form, and this form is also within the scope of application of the present invention. In the stepped-edge fixing bracket, for example, a circular disc that serves as a guide portion is formed on the housing case 151 side, and a smaller circular disc with a smaller diameter than this circular disc is formed on the valve body housing 111 side, coaxially with the larger circular disc and integrally, with a welded portion formed on the smaller circular disc.

[0096] As described above, the electric valve 200 of the second embodiment of the present invention also provides the same effects as the first embodiment, and also has the effect of reducing manufacturing man-hours.

[0097] In this invention, the valve body housing 111 and the fixing bracket 133 to be welded have been described as being made of metal, but the invention is not limited to this, and for example, a weldable thermoplastic resin may be used. Also, although the fixing brackets 133 and 233 have been described as being disc-shaped, the invention is not limited to this, and as shown in Figure 7, a plate material having another shape, such as a polygon like a hexagon, can be used as the fixing bracket 333.

[0098] As described above, the present invention provides an electric valve and a refrigeration cycle system including the same, which can solve the aforementioned conventional problems by maintaining coaxiality when fixing the valve body housing and the housing case with a simple component structure, thereby reducing manufacturing control. [Explanation of symbols]

[0099] CL center axis 11 First joint 12. Second joint 100, 200 electric valves 110 Valve body 111 Valve body housing 111A Valve chamber 111b Port 1 111c Second port 111d Joint 112 valve seats 112a Valve port 120 Needle section 121 Needle 122 Valve spring 123 Spring receiver 123a Spring engagement part 124 Washer 125 Needle Case 125a Open end 130, 230 Rotor shaft rotation part 131 Rotor shaft 131a Male threaded portion 131b Flange section 132, 232 Female threaded member 132A, 232A Guide Room 132b, 232b Female thread section 132c, 232c pressure equalization hole 133, 133A, 133B, 133C, 233 Fixing brackets 133a, 133Aa, 133Ba1, 133Ba1, 133Ca, 233a convex portion 133b, 133Ab, 133Bb, 133Cb, 233b recess 133c, 133Ac, 133Bc, 133Cc, 233c Guide section 133d, 133Ad, 133Bd, 133Cd, 233d welds 140 Rotor shaft drive unit 141 Magnet Rotor 141A Rotor chamber 141b Engagement protrusion 142 Rotor fixing member 143 Rotation stopper spring 144 Movable stopper member 150 Exterior part 151 storage cases 151a Dimple 152 Rotor support member 152a Umbrella-shaped part 152b Cylindrical section 152c Engagement recess 153 Cylindrical member 300 Refrigeration Cycle System 310 Outdoor Unit 311 Expansion valve 312 Outdoor heat exchanger 313 Flow path switching valve 314 Compressor 315 Indoor heat exchanger 320 Indoor Unit

Claims

1. A valve body unit comprising a valve body that controls the opening and closing of a valve port, The valve body unit includes an electromagnetic actuator comprising a rotor shaft and a magnetic rotor that operates a drive mechanism causing the valve body to move closer to or further away from the valve port in order to adjust the flow rate of fluid passing between the end of the valve body and the periphery of the valve port. A female threaded member that rotatably supports the rotor shaft, The valve body housing to which the female threaded member is fixed, A fixing bracket having an outer peripheral edge that protrudes from the outer circumference of the female thread member in a direction perpendicular to the central axis of the rotor shaft, and which is fixed to the female thread member and welded to the peripheral edge of the opening upper surface of the valve body housing to fix the female thread member, The electromagnetic actuator comprises a rotor shaft and a magnet rotor, and a housing case for housing them. The fixing bracket comprises a plurality of guide portions formed on the outer peripheral edge concentric with the central axis of the housing case and spaced apart along the circumferential direction of the fixing bracket, each having a contact surface that protrudes toward the inner circumferential surface of the housing case; a plurality of recesses between the plurality of guide portions that are recessed in the direction of the central axis of the fixing bracket more than the contact surface of the guide portions; and welded portions formed in the recesses that are welded and fixed to the upper surface of the opening of the valve body housing. The recess consists of an arcuate surface portion extending in the circumferential direction of the fixing bracket and inclined surfaces connected to both ends of the arcuate surface portion and reaching the contact surface of the guide portion. The outer diameter of the recess is larger than the inner diameter of the opening of the valve body housing. An electric valve characterized in that the radial recess depth of one of the recesses of the fixing bracket is greater than the radial width of the weld bead between the upper surface of the opening end of the valve body housing and the arcuate surface.

2. The electric valve according to claim 1, characterized in that the contact surface of the guide portion is formed to lie on the circumference of a common virtual circle centered on the central axis of the rotor shaft, and the diameter of the virtual circle is set to be larger than the outer diameter of the magnet rotor and smaller than the inner diameter of the inner circumferential surface of the housing case.

3. A refrigeration cycle system comprising a compressor, a condenser, an expansion valve, and an evaporator, wherein the electric valve described in claim 1 or claim 2 is used as the expansion valve.

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