Motor-operated valve and refrigeration cycle system including same

Abstract

To provide a constitution of a motor valve capable of being assembled in a state that shaft centers of a housing case and a valve main body portion are aligned with high accuracy without requiring management of complicated assembly accuracy.SOLUTION: A motor valve 100 includes: a rotor shaft 131 fixed to a central axis CL of a magnetic rotor 141 and having a male screw portion 131a; a valve main body housing 111 provided with a valve chamber 111A, ports 111b, 111c, and a joining portion 111d; a female screw member 132 provided with a female screw portion 132b screw-connected to the male screw portion 131a; a metal fixture 133 formed into a plate shape and integrally fixed to the female screw member 132; and a cup-like housing case 151. An outer periphery of the metal fixture 133 is provided with a guide portion 133c formed along a virtual circle CI having a radius from the central axis CL to a farthermost part, and fitted to the inside of the housing case 151, and a welding portion 133d welded and fixed to the joining portion 111d of the valve main body housing 111 at a part excluding the guide portion 133c.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve and a refrigeration cycle system including the same. [Background technology]

[0002] 2. Description of the Related Art In a heat pump type refrigeration cycle system, a motorized valve used as a motorized expansion valve is known, as shown in FIG. 1 of Patent Document 1, for example.

[0003] The motor-operated valve includes a stepping motor, a valve housing as a valve body, a valve mechanism, and a sealed case as a housing case. The stepping motor includes a rotor shaft, a magnet rotor in the sealed case, and a stator coil arranged on the outer periphery of the sealed case facing the magnet rotor. The male thread of the rotor shaft is screwed into the female thread of a support member of the valve mechanism, which will be 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 via a valve port of the valve seat ring. The valve mechanism includes a support member, a valve holder, and a needle valve. The synthetic resin support member is fixed by welding to the upper end surface of the valve housing through a stainless steel flange portion as a fixing metal that is insert-molded. In addition, the lower open end surface of the sealed case is welded to the upper end surface of the valve housing at a position spaced apart from the outer periphery of the flange portion with a predetermined gap.

[0004] In order for the rotor shaft and magnet rotor to rotate smoothly when the stepping motor is operated, an appropriate gap must be formed between the inner surface of the sealed case and the outer surface of the magnet rotor, and the central axis of the sealed case welded to the upper end surface of the valve housing must be aligned with the central axis of the valve housing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-115743 A Summary of the Invention [Problem to be solved by the invention]

[0006] As disclosed in the above-mentioned Patent Document 1, the upper end surface of the valve housing 1011 is welded to the opening end surface of the lower part of the sealed case 1051 at a position separated from the outer periphery of the flange part 1033 as the above-mentioned fixing metal fitting with a predetermined gap Δg, as shown in a partially enlarged view in FIG. 8(a) of the attached drawings of the present application. Note that in FIG. 8(a), the bead between the sealed case 1051 and the valve housing 1011 is not shown. The reason why the predetermined gap Δg is provided in this manner is to prevent the inner periphery of the lower end of the sealed case 1051 from climbing up onto the bead (weld buildup part) 1033w that is formed after the opening end surface of the lower part of the sealed case 1051 and the upper end surface of the valve housing 1011 are welded and the outer periphery of the flange part 1033 and the upper end surface (annular joint part 1011d) of the valve housing 1011 are fillet welded. If the above-mentioned gap Δg is not provided between the inner peripheral surface of the lower part of the sealed case 1051 and the outer peripheral part of the flange part 1033, the inner peripheral surface of the lower end of the sealed case 1051' will ride up on the bead (weld build-up part) 1033w' as shown in the partially enlarged views of Figures 9(a) and 9(b), and as a result, the axis of the sealed case 1051' will be misaligned with the axis of the valve housing 1011' and an axial gap Δg' will be formed between the sealed case 1051' and the valve housing 1011'. Therefore, depending on the size of the gap Δg', there is a risk that the open end face of the lower part of the sealed case 1051' cannot be welded to the upper end face 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 a jig or the like in the welding machine so that the central axis of the sealed case 1051 and the central axis of the valve housing 1011 are aligned on a common central axis.

[0008] However, if it is necessary to adjust and hold the positions of the sealed case 1051 and the valve housing 1011 by a jig 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 aligned with a common central axis in order to ensure high assembly accuracy during the assembly process, control of assembly accuracy becomes complicated in the assembly work process of the motor-operated valve. Therefore, in assembling 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 the assembly can be performed by a simple welding operation.

[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 are configured so that the axes of the accommodating case and the valve main body can be aligned with high precision when assembled, without the need for complicated management of assembly accuracy. [Means for solving the problem]

[0010] In order to achieve the above object, the motor-operated valve according to the present invention comprises a valve body housing provided with a valve chamber for movably accommodating a valve body unit including 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 in the connection port, an electromagnetic actuator including a rotor shaft and a magnet rotor for operating a drive mechanism that causes the valve body unit to perform an operation for controlling the valve body to approach or move away from the valve port of the valve seat so as to adjust the flow rate of fluid passing between an end of the valve body and a periphery of the valve port of the valve seat, an internal thread member that guides the valve body unit and rotatably supports the rotor shaft, and an internal thread member that is threaded in a direction perpendicular to a central axis of the rotor shaft. and a housing case that houses a rotor shaft and a magnet rotor of an electromagnetic actuator, the female threaded member, and the fixing bracket, the fixing bracket having an outer circumferential edge portion protruding from an outer circumferential portion of the female threaded member and being fixed to the female threaded member by being welded to the periphery of the open end of the valve body housing into which the lower part of the female threaded member is inserted; and a housing case that houses the rotor shaft and magnet rotor of the electromagnetic actuator, the female threaded member, and the fixing bracket, the fixing bracket having a plurality of guide portions formed on the outer circumferential edge portion so as to be concentric with the central axis of the housing case, each guide portion having an abutment surface that abuts against the inner peripheral surface of the housing case, and welded portions formed inward in the central axial direction of the fixing bracket than the abutment surfaces of the guide portions between the guide portions, the welded portions being fixed by welding to the upper surface of the open end of the valve body housing.

[0011] The abutment surfaces of the guide portions are formed so as to be on the circumference of a common imaginary circle centered on the central axis of the rotor shaft, and the diameter of the imaginary 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 accommodating case.

[0012] On the contact surface of the guide portion, at least an intersection point where a line dividing a circumference of the central axis of the fixture into N equal parts at equal angles (N=an integer of 3 or more) intersects with the imaginary circle may be located.

[0013] At least one of the contact surfaces of the guide portions of the fixing bracket may be an arcuate surface extending along the inner circumferential surface of the accommodating case. The welded portion may be fixed to the upper surface of the open end of the valve body housing by a plurality of spot welds, a plurality of spaced-apart fillet welds, or a continuous fillet weld.

[0014] The motor-operated valve according to the present invention further comprises a valve body housing provided with a valve chamber for movably accommodating a valve body unit including a valve body communicating with at least one connection port connected to a fluid pipeline and controlling the opening and closing of a valve port of a valve seat provided in the connection port, an electromagnetic actuator including a rotor shaft and a magnet rotor for operating a drive mechanism for controlling the valve body to approach or move away from the valve port of the valve seat so as to adjust the flow rate of fluid passing between an end of the valve body and a periphery of the valve port of the valve seat, an internal thread member for guiding the valve body unit and rotatably supporting the rotor shaft, and a rotor shaft having an outer circumferential edge portion protruding from an outer circumferential portion of the internal thread member in a direction perpendicular to a central axis of the rotor shaft and fixed to the internal thread member. a stepped edge fastening fitting for fastening the female threaded member by being welded to an upper surface of an open end of a valve body housing into which a lower portion of the female threaded member is inserted, a rotor shaft and a magnet rotor of an electromagnetic actuator, the female threaded member, and a housing case for housing the fastening fitting, the stepped edge fastening fitting having a guide portion formed concentrically with the central axis of the housing case and having an abutment surface abutting 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 an area surrounded by the inner circumferential surface of the housing case and the upper surface of the open end of the valve body housing, the welded portion being welded to the upper surface of the open end of the valve body housing closer to the central axis of the rotor shaft than the abutment surface of the guide portion. The abutment surfaces of the guide portions are formed to be on the circumference of a common imaginary circle centered on the central axis of the rotor shaft, and the diameter of the imaginary circle may be set to be greater than the outer diameter of the magnet rotor and smaller than the inner diameter of the inner circumferential surface of the housing case. When a stepped-edge fixing bracket has multiple guide portions, the abutment surface of each guide portion may be configured to have at least an intersection where a line (N = an integer of 3 or more) dividing the circumference of the central axis of the fixing bracket into N equal parts at equal angles intersects with an imaginary circle.

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

[0016] In the electric valve of the present invention and the refrigeration cycle system including the same, 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 accommodating case, each of which has an abutment surface that abuts against the inner peripheral surface of the accommodating case, and a weld portion formed inward in the central axial direction of the fixing bracket than the abutment surfaces of the guide portions between the guide portions, and which is welded to the periphery of the opening end of the valve body housing.Therefore, the accommodating case and the valve body housing can be assembled with their respective axes aligned with high precision, without the need for complicated management of assembly accuracy. [Brief description of the drawings]

[0017] [Figure 1] 1 is a vertical sectional view showing a schematic configuration of a motor-operated valve according to a first embodiment of the present invention. [Diagram 2] Figure 2(a) is a cross-sectional view taken along line IIA-IIA in Figure 1, showing the shape of the fixing bracket, Figure 2(b) is a partially enlarged view showing an enlarged IIB portion of Figure 2(a), and Figure 2(c) is a diagram explaining the guide portion of the fixing bracket shown in Figure 2(a). [Diagram 3] FIG. 3(a) is a diagram showing a second embodiment of the fastening bracket, FIG. 3(b) is a diagram showing a third embodiment of the fastening bracket, and FIG. 3(c) is a diagram showing a fourth embodiment of the fastening bracket. [Figure 4] FIG. 2 is a vertical sectional view showing a schematic configuration of a second embodiment of a motor-operated valve according to the present invention. [Diagram 5] 5 is an enlarged cross-sectional view showing a portion V shown in FIG. 4. [Figure 6] 1 is a diagram showing an example of the configuration of a refrigeration cycle system using an example of a motor-operated valve according to the present invention. [Figure 7] 13A and 13B are diagrams showing modified examples of a fixing bracket used in the example of the motor-operated valve according to the present invention. [Figure 8]FIG. 8(a) is a partial cross-sectional view showing an enlarged view of the joining structure of the sealing case, valve body, and fixing bracket of an electric valve in a prior art document, and FIG. 8(b) is a partial cross-sectional view of the sealing case, valve body, and fixing bracket shown in FIG. 8(a). [Figure 9] FIG. 9(a) is a partial cross-sectional view showing an enlarged view of another example of the joining structure of the sealing case, valve body and fixing bracket of an electric valve in a prior art document, and FIG. 9(b) is an enlarged cross-sectional view showing an enlarged view of portion IXB shown in FIG. 9(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] FIG. 1 shows a schematic configuration of a motor-operated valve according to a first embodiment of the present invention together with a piping.

[0019] In the following description, the concepts of up and down correspond to, for example, the up and down in FIG. 1 and indicate the relative positional relationship of each member, but do not indicate the absolute positional relationship.

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

[0021] During cooling operation, the expansion valve 311 is connected to the primary side pipe Du1 by a connecting pipe (second joint 12) described later, and is connected to the secondary side pipe Du2 by a connecting pipe (first joint 11). The primary side pipe Du1 connects the outlet (first port 312a) of the outdoor heat exchanger 312 and the expansion valve 311, and the secondary side pipe Du2 connects the inlet (first port 315a) of the indoor heat exchanger 315 and 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, 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 are arranged. The compressor 314 is connected to the flow path switching valve 313 by pipes Du4 and Du5. The other end of the pipe Du3 is connected to a port 313d of the flow path switching valve 313. The other end of the pipe Du6 is connected to a port 313b of the flow path switching valve 313. One end of the pipe Du4 is connected to a port 313c of the flow path switching valve 313, and the other end of the pipe Du4 is connected to a discharge port of the compressor 314. One end of the pipe Du5 is connected to a port 313a of the flow path switching valve 313, and the other end of the pipe Du5 is connected to a suction port of the compressor 314. During cooling operation, the port 313a communicates with the port 313d, and the port 313b communicates with the port 313c. As a result, during cooling operation, the refrigerant in the refrigeration cycle system circulates, for example, along the direction indicated by the dashed arrow in Fig. 6, with the outdoor heat exchanger 312 functioning as a condenser and the indoor heat exchanger 315 functioning as an evaporator. Note that, although the embodiment in which the expansion valve 311 is joined to the primary side pipe Du1 at the second joint 12 and joined to the secondary side pipe Du2 at the first joint 11 during cooling operation has been described, the present invention is not limited to this example, and for example, during cooling operation, the expansion valve 311 may be joined to the primary side pipe Du1 at the first joint 11 and joined to the secondary side pipe Du2 at the second joint 12.

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

[0023] As shown in FIG. 1, the electric valve 100 is configured to include a valve drive unit that is arranged in a cylindrical storage case 151 that constitutes part of the exterior part 150 described later and drives a valve body unit described later to be raised and lowered, a valve main body 110 that is connected to the lower end of the storage case 151 and has a valve seat 112 having a valve port 112a that is opened and closed by the tip of a needle 121 serving as a valve body, and a valve body unit that is arranged in the valve main body 110 and includes a needle 121 that opens and closes the valve port 112a of the valve seat 112.

[0024] The valve drive unit is mainly composed of a rotor shaft 131 which moves a valve body unit up and down, a female screw member 132 which has a female screw portion 132b formed with a female screw which is concentrically fitted with a male screw portion 131a of the rotor shaft 131 and which is fixed to the valve body housing 111 and serves as a guide support portion which guides the valve body unit so that it can be moved up and down, a magnet rotor 141 which is fixed concentrically to the guide shaft portion of the rotor shaft 131, rotatably supported, and magnetized, and a stator coil (not shown) which is disposed on the outer periphery of the housing case 151 and rotates the magnet rotor 141. The magnet rotor 141 and the stator coil constitute a part of a stepping motor which serves as an electromagnetic actuator.

[0025] The rotor shaft 131 and the female screw member 132 form a part of a rotor shaft rotating unit 130, which will be described later. The magnet rotor 141 and the stator coil form a part of a rotor shaft driving unit 140, which will be described later.

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

[0027] The upper surface of the open end that is joined to the lower end of the storage case 151 described later, i.e., a ring-shaped joining portion 111d, is formed around the periphery of the circular open end at the upper part of the valve body housing 111.

[0028] Here, 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, welding, or the like, but are not limited to this. Also, in the motor-operated valve of this embodiment, the refrigerant flows through the first port 111b as the inlet side and the second port 111c as the outlet side, but this is not limited thereto, and the motor-operated valve 100 of this embodiment is a bidirectional motor-operated valve that can also use the first port 111b as the outlet side and the second port 111c as the inlet side.

[0029] The valve seat 112 is formed of a metal material such as stainless steel or copper alloy, and is fixed by welding, brazing, or the like around the second port 111c to which the second joint 12 of the valve body housing 111 is connected. The needle 121, together with the needle case 125, is arranged so as to be able to move close to or away from the valve port 112a, thereby controlling the flow rate of the refrigerant passing through the valve port 112a. Note that, although the valve seat 112 is a separate member from the valve body housing 111 here, it may be molded integrally with the valve body housing 111.

[0030] The valve body unit 120 is composed of the following main elements: a needle 121 that opens and closes the valve port 112a of the valve seat 112; a cylindrical resin spring holder 123 that cooperates with a resin washer 124 to engage the flange portion 131b of the rotor shaft 131 with the inner peripheral edge of the opening end 125a of the needle case 125; a valve spring 122 that is arranged between the spring engagement portion 123a of the spring holder 123 and the annular flat portion for spring holder at one end of the needle 121 and biases the two in a direction separating them from each other; and a cylindrical needle case 125 that houses the spring holder 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 a central axis CL by a rotor shaft 131 (described later) or the like. This controls the flow rate of the refrigerant passing through the valve port 112a. The needle 121 has a gently protruding shape at the center on the side close to the valve port 112a. This protruding shape is formed so that the effective opening area increases and decreases depending on the position of the needle 121 by controlling the position of the needle 121 relative to the valve port 112a described above.

[0032] The valve spring 122 disposed inside the approximately cylindrical needle case 125 is compressed and disposed between the needle 121 and a spring engagement portion 123a of a spring receiver 123 described later. The provision of the valve spring 122 serves to prevent a screw thrust from a rotor shaft 131 described later and the like from being directly applied to the needle 121 and the valve port 112a, etc., and as a result, has the effect of increasing the durability of the motor-operated valve 100.

[0033] The spring bearing 123 is formed, for example, in a substantially cylindrical shape from resin or the like. The spring bearing 123 is disposed inside the needle case 125 between a flange portion 131b of the rotor shaft 131 (described later) and the needle 121, and is disposed along the central axis CL inside the valve spring 122. A disk-shaped spring engagement portion 123a protruding toward the outer diameter direction is formed at the end of the spring bearing 123 that contacts the rotor shaft 131. By disposing the spring bearing 123 inside the valve spring 122 and along the central axis CL, the concentricity between the valve spring 122 and the spring bearing 123 is improved, and the operability of the valve body unit 120 is improved.

[0034] The washer 124 is formed in a circular ring shape from, for example, a highly lubricating resin. The washer 124 is disposed between a flange portion 131b of the rotor shaft 131, which will be described later, and an opening end 125a of the needle case 125, which will be described later. By providing the washer 124, it is possible to suppress the rotation of the rotor shaft 131 from being directly transmitted 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 formed into a substantially cylindrical shape by pressing or the like. An open end 125a is formed at the end of the needle case 125 on the rotor shaft 131 side. The needle case 125 has the function of transmitting the screw driving force of the rotor shaft 131, which will be described later, to the needle 121. The open end 125a of the needle case 125 is disposed so as to engage with a flange portion 131b of the rotor shaft 131 facing each other. In addition, 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 driving portion 140 includes a magnet 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, which will be described later, and is composed of a multi-pole permanent magnet formed of a ferrite sintered body or the like, with N and S poles arranged alternately. In this embodiment, the magnet rotor 141 is placed on the outer periphery of the housing case 151, which will be described later, and constitutes a stepping motor together with a stator coil, which is composed of a yoke, a bobbin, a coil, and the like, not shown. Note that, although a stepping motor is used here, the present invention is not limited to this, and similar effects can be obtained by using other electric motors that can rotate the magnet rotor 141.

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

[0039] The rotation stopper spring 143 has a coil spring shape, and is wound around a cylindrical portion 152b of the rotor support member 152 (described later). The upper and lower ends of the rotation stopper spring 143 are each engaged with the cylindrical portion 152b.

[0040] The movable stopper member 144 has a coil spring shape of about one turn, and is rotatably disposed around the cylindrical portion 152b of the rotor support member 152. One end of the movable stopper member 144 is engaged with an engagement protrusion 141b formed integrally with a predetermined pole of the magnet rotor 141 having multiple poles, and the other end is screwed into 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 disposed without any rattle with respect to the central axis CL of the motor-operated valve 100.

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

[0042] The housing case 151 is made of a non-magnetic metal material such as a stainless steel plate, and is formed into a cup shape by pressing or the like. The housing case 151 has an outer diameter substantially the same as that of the above-mentioned valve body housing 111. 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 all around, for example, by TIG welding, plasma welding, laser welding, resistance welding, or the like. This results in the interior of the housing case 151 being sealed. In addition, the housing case 151 is formed with a dimple 151a for engaging with an engagement recess 152c formed in a cup-shaped portion 152a of a rotor support member 152, which will be described later.

[0043] The rotor support member 152 is formed by pressing or the like from a material such as a stainless steel plate. The rotor support member 152 is composed of a cup-shaped portion 152a that is fixed in contact with the housing case 151, and a cylindrical portion 152b that extends downward from the center of the cup-shaped portion 152a. An engagement recess 152c is formed in the cup-shaped portion 152a. The engagement recess 152c engages with a dimple 151a of the housing case 151, whereby the rotor support member 152 is fixed to a predetermined mounting position 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 disposed inside the cylindrical portion 152b of the rotor support member 152, and rotatably holds the upper end portion (guide shaft portion) of the rotor shaft 131.

[0045] The rotor shaft rotating portion 130 includes a rotor shaft 131 , a female screw member 132 , and a fixing metal fitting 133 .

[0046] The rotor shaft 131 is made of, for example, a metal material, is formed in a generally cylindrical shape, and extends in the vertical direction along the central axis CL of the motor-operated valve 100. The magnet rotor 141, which is rotated by an electric motor such as a stepping motor described later, is fixed around the axis of the rotor shaft 131 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 a portion of the rotor shaft 131 closer to the needle 121 than the rotor fixing member 142. The male threaded portion 131a is screwed into a female threaded portion 132b of a female threaded member 132, which will be described later. Furthermore, a flange portion 131b that protrudes in a disk shape in the outer diameter direction is formed on an end portion of the rotor shaft 131 closer to the needle 121 than the male threaded portion 131a. The flange portion 131b is disposed at a position spaced apart from the inner circumferential surface of the opening end 125a of the needle case 125. The diameter of the flange portion 131b is larger than the diameter of the hole in the opening end 125a, and prevents it from coming off.

[0048] The female screw member 132 is formed, for example, from resin into a generally cylindrical shape. A female screw portion 132b that fits into the male screw portion 131a of the rotor shaft 131 is formed on the upper part of the female screw member 132. The female screw portion 132b is formed concentrically with the central axis CL of the motor-operated valve 100. The female screw member 132 constitutes a 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 by being screw-coupled with the rotor shaft 131.

[0049] A guide chamber 132A is formed in a portion of the female screw member 132 below the female screw portion 132b, which slidably accommodates the needle case 125 together with the needle 121. The inner peripheral surface of the female screw member 132 forming the guide chamber 132A is a guide surface that movably guides the outer peripheral surface of the cylindrical needle case 125. A pressure equalizing hole 132c penetrating to the outside is provided in a portion of the inner peripheral surface forming the guide chamber 132A. This allows the guide chamber 132A to communicate with the rotor chamber 141A, facilitating the movement of the rotor shaft 131 and the needle case 125. A protruding portion 132B is formed at an end portion of the female screw member 132 below the portion where the pressure equalizing hole 132c is formed, which is inserted into the open end portion of the valve body housing 111 described above. A fixing metal fitting 133 is fixed to the protruding portion 132B by insert molding. At this time, the fixing metal fitting 133 is fixed concentrically with the central axis of the female screw member 132 .

[0050] The fixing metal fitting 133 is, for example, a disk-shaped metallic member as shown in Fig. 2(a). An arcuate surface or an inclined surface of a recess 133b on the outer periphery of the fixing metal fitting 133 (described later) is fixed to an 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 metal fitting 133. At that time, the female thread member 132 is fixed concentrically with the central axis of the valve body housing 111.

[0051] The motor-operated valve 100 of the first embodiment of the present invention described above is provided with a structure that can automatically maintain coaxiality between the casing 151 and the female screw member 132 by using the fixing metal fitting 133 of the above-mentioned simple shape in order to solve the conventional problems. Hereinafter, the structure will be described with reference to Figures 2(a) and 2(b).

[0052] 2(a) is a cross-sectional view taken along line IIA-IIA in FIG. 1, showing the shape of fixing bracket 133, FIG. 2(b) is a partially enlarged view showing portion IIB in FIG. 2(a), and FIG. 2(c) is a view explaining guide portion 133c (hereinafter also referred to as protrusion 133a) of fixing bracket 133 shown in FIG. 2(a).

[0053] As shown in Fig. 2(a) and Fig. 2(b), the fixing metal fitting 133 as the first embodiment is, for example, a roughly disk-shaped metal member, and four protrusions 133a are provided along the outer circumference of the disk shape. Each of the protrusions 133a has a contact surface that protrudes in the radial direction so as to contact the inner peripheral surface of the storage case 151. The shape of the four protrusions 133a is formed in a roughly arc shape so that the tip portion contacts the inner peripheral surface 151b of the cup-shaped storage case 151. Note that the contact surfaces are not limited to being in surface contact only, and 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 at equal angular intervals (90°) along the circumferential direction of the fixing metal fitting 133. Moreover, each protrusion 133a is formed to have the same width W along the circumferential direction. Four recesses 133b are formed between adjacent protrusions 133a. The recesses 133b are formed of an arc surface portion extending in the circumferential direction of the fixing metal fitting 133 and a slope portion that is connected to both ends of the arc surface portion and reaches the contact surface of the guide portion 133c. The radius of curvature of the outer circumferential surface forming the arc portion of the recesses 133b is set to be smaller than the radius of curvature of the contact surface forming the protrusions 133a.

[0055] It should be noted that the recesses 133b are provided in the outer periphery between the plurality of protrusions 133a, except for the protrusions 133a.

[0056] At this time, the recess 133b is formed of an arc surface portion extending in the circumferential direction of the fixing metal fitting 133 and a slope portion continuing to both ends of the arc surface portion and reaching the contact surface of the guide portion 133c. In the recess 133b, for example, when all the arc surface portions are fillet welded and the slope portion is not welded, the welded arc surface portion forms the welded portion 133d. Also, for example, when the arc surface portion is welded at a predetermined interval by a plurality of spot welding and the slope portion is not welded, each spot welded portion forms the welded portion 133d. Furthermore, when only the above-mentioned two slope portions are spot welded or fillet welded and the arc surface portion is not welded, the spot welded or fillet welded portion forms the welded portion 133d. The arc surface portion or slope portion that is not welded, in other words, the arc surface portion or slope portion that does not need to be welded, may be included in the welded area as shown in FIG. 2(b).

[0057] In this example, all of the abutment surfaces of the four protrusions 133a abut against the inner surface 151b of the storage case 151, but this is not necessarily required; for example, all of the abutment surfaces of the four protrusions 133a (guide portions 133c) do not have to abut against the inner surface 151b of the storage case 151.

[0058] The guide portion 133c (protruding portion 133a) will be described in more detail with reference to Fig. 2(a) and Fig. 2(c). The contact surfaces of the guide portions 133c are formed so as to be on the circumference of a common imaginary circle CI centered on the central axis CL of the rotor shaft 131. The radius of the imaginary circle CI is set, for example, to the length to the farthest part from the central axis CL of the fixing metal fitting 133 that is concentric with the rotor shaft 131. Thereby, during assembly, the fixing metal fitting 133 is fitted into the inner peripheral surface 151b of the housing case 151. It is sufficient that the guide portion 133c maintains the coaxiality (coaxiality, concentricity) between the housing case 151 and the female screw member 132 to such an extent that interference between the inner peripheral surface 151b of the housing case 151 and the magnet rotor 141 that rotates can be prevented. For this reason, the diameter of the imaginary circle CI of the contact surface of the guide portion 133c described above 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 the magnet rotor 141<diameter of the imaginary circle CI<inner diameter of the housing case 151). As shown in FIG. 2(c), it is preferable 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 imaginary circle CI intersects with a line that divides the circumference of the central axis CL of the fixing metal fitting 133 into four equal parts at equal angles. Note that, although it is divided into four equal parts here, this is not limited thereto, and the above-mentioned coaxiality can be maintained by dividing it into N equal parts (N is an integer of 3 or more).

[0059] When the arcuate surfaces or inclined surface portions of the four recesses 133b are welded to the joint portion 111d of the valve body housing 111, they may be welded to the welded portion 133d (described later) located in a portion other than the guide portion 133c. As described above, the recesses 133b are formed of an arcuate surface portion extending in the circumferential direction of the fixing metal fitting 133 and an inclined surface portion that is connected to both ends of the arcuate surface portion and reaches the abutment surface of the guide portion 133c. For example, as shown in FIG. 2(b), the welded arcuate surface portion or inclined surface portion is the welded portion 133d in the range including not only the arcuate surface portion but also the inclined surface portion in FIG. 2(a), which is the portion closest to the central axis CL forming the recesses 133b. As a result, the bead formed in the welded portion 133d is not outside the imaginary circle CI but is formed in the area inside the imaginary circle CI, so there is no risk of the bead interfering with the inner circumferential surface 151b of the housing case 151.

[0060] 2(a) , the welded portion 133d cannot be provided inside the inner diameter of the annular joint portion 111d of the valve body housing 111. This is because the fixing metal fitting 133 and the valve body housing 111 cannot come into contact with each other, making it impossible to weld them together.

[0061] In assembling the motor-operated valve 100 in this configuration, first, the rotor shaft 131 and the needle case 125 to which the needle 121 is fixed, which are assembled together, are attached to the female screw member 132, and then the protruding portion 132B of the female screw member 132 is inserted into the open end of the valve body housing 111, and the fixing metal fitting 133 is placed on the periphery of the open end of the valve body housing 111 to which the valve seat 112 and the like are attached in advance. Next, for example, the arc surface portion of the recess 133b of the fixing metal fitting 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 arc surface portion, and the joint portion 111d of the valve body housing 111.

[0062] The radial gap between the protruding portion 132B of the female screw 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 above-mentioned valve body housing 111 is removed from the first welding machine, and the assembled valve body housing 111 is transferred to a support table (not shown) of a second welding machine. Then, the lower end of the accommodation case 151 is placed without any gap on the periphery of the open end of the valve body housing 111 so that the inner circumferential surface 151b of the accommodation case 151 to which the rotor support member 152 and the like are attached abuts against the abutment surface of the guide portion 133c of the fixing metal fitting 133 at the periphery of the open end of the valve body housing 111 to which the welded portion 133d of the fixing metal fitting 133 is fixed. As a result, the axis of the accommodation case 151 and the axis of the rotor shaft 131 and the female screw member 132 are automatically aligned.

[0064] Then, the accommodating case 151 and the valve body housing 111, which have approximately the same outer diameter, are held as a whole on a support table of the second welding machine, so that welding work is performed on the lower end surface of the accommodating case 151 and the joint portion 111d of the valve body housing 111 with the axes of the accommodating case 151 and the valve body housing 111 aligned with each other. As a result, a second bead is formed on the lower end surface of the accommodating case 151 and the joint portion 111d of the valve body housing 111 adjacent to the above-mentioned first bead.

[0065] In this way, by providing multiple guide portions 133c (convex portions 133a) and multiple recesses 133b on the outer periphery of the fixing bracket 133, which is, for example, in a disk shape, the abutment surface of the guide portions 133c abuts against the inner surface 151b of the accommodating case 151, and the fixing bracket 133 and the valve body housing 111 can be welded and fixed together by weld portions 133d formed in the recesses 133b that do not abut against the inner surface 151b of the accommodating case 151.Since the weld bead formed at the weld portions 133d does not interfere with the inner surface 151b of the accommodating case 151, the valve body housing 111 and the accommodating case 151 are in contact with each other without any gaps, and can be fixed together while maintaining coaxiality.

[0066] In the above example, it is not necessary for the contact surfaces of all guide portions 133c to contact the inner surface of the accommodating case 151, and the end of the accommodating case 151 and the end of the valve body housing 111 may be brought into close contact with each other in a state in which the contact surfaces of all guide portions 133c are not in contact with the inner surface of the accommodating case 151, thereby maintaining the coaxiality between the fixing bracket 133 and the accommodating case 151. This is because the contact surface of the guide portion 133c acts as a mechanical stopper to prevent the accommodating case 151 from shifting from a range in which the magnet rotor 141 does not contact the inner circumferential surface 151b of the accommodating case 151 to a range in which the magnet rotor 141 does contact the inner circumferential surface 151b of the accommodating case 151 when the magnet rotor 141 rotates.

[0067] Although the protrusions 133a (guide portions 133c) formed on the fixing bracket 133 are provided in four locations here, it is sufficient that they are provided in two or more locations that satisfy the above conditions as long as they are coaxial with the casing 151. Second to fourth embodiments (modified examples) of the fixing bracket will be described below with reference to Figures 3(a) to 3(c).

[0068] FIG. 3(a) is a diagram showing another example of the shape of the fixing bracket, FIG. 3(b) is a diagram showing yet another example of the shape of the fixing bracket, and FIG. 3(c) is a diagram showing yet another example of the shape of the fixing bracket.

[0069] As shown in FIG. 3(a), the fixing metal fitting 133A as the second embodiment has three protruding portions 133Aa (hereinafter also referred to as guide portions 133Ac), and three recessed portions 133Ab are formed between the protruding portions 133Aa on the circumference. The three protruding portions 133Aa are formed spaced apart at equal angular intervals, for example, 120° intervals. The widths W of the protruding portions 133Aa along the circumferential direction are set to be the same. The recessed portions 133Ab are formed spaced apart at equal angular intervals, for example, 120° intervals. The lengths of the arcuate surface portions forming the recessed portions 133Ab along the circumferential direction are set to be the same. 3(a), the contact surface of the guide portion 133Ac that contacts the inner peripheral 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 metal fitting 133A into thirds at equal angles and a virtual circle (a common circle on which the above-mentioned contact surfaces exist, similar to the virtual circle shown in FIG. 2(c)). This satisfies the condition for maintaining the above-mentioned coaxiality.

[0070] In this case, the recess 133Ab is formed of an arcuate surface portion extending in the circumferential direction of the fixing metal fitting 133, and a sloped surface portion that is connected to both ends of the arcuate surface portion and reaches the abutment surface of the guide portion 133Aa. In the recess 133Ab, for example, if the arcuate surface portions are all fillet welded and the sloped surface portions are not welded, the welded arcuate surface portions form the welded portion 133Ad.

[0071] 3(b), the fixing metal fitting 133B of the third embodiment has a narrow protrusion 133Ba1 (hereinafter also referred to as a guide portion 133Bc) with a width W and a protrusion 133Ba2 consisting of an arcuate surface portion having a central angle of about 120° along the circumferential direction, which are provided at positions facing each other. Between the two protrusions 133Ba1 and 133Ba2, two recesses 133Bb are formed, each including 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 surfaces of the protrusions 133Ba2 are different and not uniform. 3(b), the contact surface of the guide portion 133Bc that contacts the inner peripheral 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 metal fitting 133B into thirds at equal angles and a virtual circle (a common circle on which the above-mentioned contact surfaces exist, similar to the virtual circle shown in FIG. 2(c)). This satisfies the condition for maintaining the above-mentioned coaxiality.

[0072] In this case, the recess 133Bb is formed of an arcuate surface portion extending in the circumferential direction of the fixing metal fitting 133 and a sloped surface portion continuing to both ends of the arcuate surface portion and reaching the abutment surface of the guide portion 133Bc. In the recess 133Bb, for example, if the arcuate surface portions are all fillet welded and the sloped surface portions are not welded, the welded arcuate surface portions form the welded portion 133Bd.

[0073] Furthermore, as shown in FIG. 3(c), the remaining portion of the fixing metal fitting 133C as the fourth embodiment other than the two opposing convex portions 133Ca (hereinafter also referred to as guide portions 133Cc) has two opposing concave portions 133Cb. The contact surfaces of the two convex portions 133Ca are formed by arc surfaces having the same central angle. The outer peripheral surfaces forming the two concave portions 133Cb are formed by curved surfaces having the same shape. Also, as shown in FIG. 3(c), the contact surface of the guide portion 133Cc that contacts the inner peripheral surface 151b of the housing case 151 is located at the intersection of a line dividing the circumference of the central axis line CL of the fixing metal fitting 133C into four equal parts at equal angles and a virtual circle. This satisfies the condition for maintaining coaxiality.

[0074] In this case, the recess 133Cb is formed of a curved surface portion extending in the circumferential direction of the fixing metal fitting 133 and a sloped surface portion continuing to both ends of the curved surface portion and reaching the abutment surface of the guide portion 133Ca. In the recess 133Cb, for example, if all the curved surface portions are fillet welded and the sloped surface portions are not welded, the welded curved surface portions form the welded portion 133Cd.

[0075] By using fixing brackets 133A, 133B, and 133C, which are the second to fourth embodiments (variant examples) of fixing bracket 133, the valve body housing 111 and the accommodating case 151 come into contact with each other without any gaps, and coaxiality is maintained, just as in the case where fixing bracket 133 shown in Figure 2(a) is used.

[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 periphery of the fixing bracket 133, interference between the weld beads that may occur at the welded portions and the accommodating case 151 can be prevented, and the valve body housing 111 and the accommodating case 151 can be in contact with each other without any gaps and fixed while maintaining coaxiality, making it possible to reduce manufacturing management.

[0077] The operation of the motor-operated valve 100 thus configured will now be described.

[0078] When driving the motor-operated valve 100, first, a drive pulse signal is given to the stator. This causes the magnet rotor 141 to rotate according to the number of pulses, which in turn causes the rotor shaft 131 to rotate. Due to the threaded engagement between the male threaded portion 131a of the rotor shaft 131 and the female threaded portion 132b of the female thread member 132, the rotor shaft 131 moves along the central axis CL while rotating.

[0079] To close the motor-operated valve 100, it is necessary to move the rotor shaft 131 downward. When the rotor shaft 131 moves further downward after the needle 121 abuts against the valve seat 112, the valve spring 122 contracts via the spring receiver 123, and the needle 121 is pressed against the valve seat 112 by the load due to the reaction force of the valve spring 122, so that the motor-operated valve 100 is controlled to a securely closed valve state.

[0080] At this time, the needle 121 is pressed against the valve seat 112 via the spring receiver 123 and the valve spring 122, so that the frictional resistance of the seating surface becomes greater than the frictional resistance between the rotor shaft 131 and the highly slippery spring receiver 123, and the rotating rotor shaft 131 slides between itself and the spring receiver 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, because the rotor shaft 131 is pushed in, the washer 124 descends together with the flange portion 131b of the rotor shaft 131, so that the upper surface of the washer 124 is no longer in 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, when returning the motor-operated valve 100 from the valve closed state to the valve open state, it is necessary to rotate the rotor shaft 131 in the reverse direction to move it upward. As the rotor shaft 131 rises, the valve spring 122 expands via the spring receiver 123. At this time, the needle 121 maintains its contact with the valve seat 112. When the rotor shaft 131 further moves upward, the flange portion 131b of the rotor shaft 131 comes into contact with the inner surface of the opening end 125a of the needle case 125 via the washer 124, and lifts the needle case 125 while rotating. When the needle case 125 is lifted, the needle 121 fixed thereto also moves upward, and the needle 121 and the valve port 112a of the valve seat 112 are no longer in contact with each other, and the motor-operated valve 100 is controlled to the valve open state.

[0082] At this time, the needle case 125 and the needle 121 are driven by the rotor shaft 131 via the highly lubricious washer 124, which prevents the rotation of the rotor shaft 131 from being transmitted to the needle case 125 and the needle 121. This prevents wear between the needle 121 and the valve port 112a.

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

[0084] Fig. 4 is a schematic diagram showing the configuration of a second embodiment of the motor-operated valve according to the present invention together with a piping. Fig. 5 is an enlarged cross-sectional view showing a portion V shown in Fig. 4 in an enlarged manner.

[0085] As shown in Fig. 4 and Fig. 5, the configuration of the motor-operated valve 200 differs from that of the motor-operated valve 100 having the fixing bracket 133 in that the motor-operated valve 200 includes a stepped edge fixing bracket 233 that is insert-molded into the female screw member 233. More specifically, the outer periphery of the stepped edge fixing bracket 233, which is made of metal and has a roughly disk-shaped shape, has an abutment surface that abuts against the inner circumferential surface 151b of the accommodating case 151, and has a step portion that includes a convex portion 233a (hereinafter also referred to as a guide portion 233c) that protrudes outward, and a recessed portion 233b that forms a gap in a portion surrounded by the inner circumferential surface 151b of the accommodating 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 (joint portion 111d) that forms the recessed portion 233b, and a part of the lower end portion of the stepped edge fixing bracket 233 supported by the upper end surface of the valve body housing 111, form a welded portion 233d, as shown in Fig. 5.

[0086] Other than that, the configuration of the motor-operated valve 200 is the same as the configuration of the motor-operated valve 100 described above, so the same components are given the same reference numerals and duplicated explanations are omitted.

[0087] 4 and 5, the step portion of the above-mentioned stepped-edge fixing bracket 233 is formed in the thickness direction along the central axis CL of the motor-operated valve 200. The recess 233b, which is the portion 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, since the lower end surface of the fixing bracket 233 is fillet-welded to the joint portion 111d of the valve body housing 111. In addition, the abutment surface of the guide portion 233c, which is the portion farther from the central axis CL than the recess 233b, abuts against the inner circumferential surface 151b of the accommodating case 151, and therefore is formed on the accommodating case 151 side, which is the upper side of the fixing bracket 233.

[0088] Here, it is not necessary that the entire contact surface of the protruding portion 233 a contacts the inner circumferential surface 151 b of the containing case 151 .

[0089] As a condition of the guide portion 233c, similarly to the first embodiment, the stepped edge fixing metal fitting 233 is fitted into the inner peripheral surface 151b of the housing case 151 so that the contact surface of the guide portion 233c contacts the inner peripheral surface 151b of the housing case 151. The guide portion 233c only needs to maintain the coaxiality (coaxiality, concentricity) of the housing case 151 and the valve body housing 111 to such an extent that interference between the inner peripheral surface of the housing case 151 and the rotating magnet rotor 141 can be prevented. For this reason, the diameter of the contact surface of the above-mentioned 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 peripheral surface 151b of the housing case 151 (outer diameter of the magnet rotor 141<diameter of the contact surface<inner diameter of the housing case 151).

[0090] Also, here, a lower end portion forming a part of the recess 233b, which is a portion other than the above-mentioned guide portion 233c, is welded and fixed to the joint portion 111d of the valve body housing 111. As a result, the welded portion 233d is formed by the lower end portion forming the recess 233b of the stepped-edge fixing fitting 233 and the joint portion 111d of the valve body housing 111.

[0091] It is not necessary for the entire recess 233b to be the welded portion 233d, and only a portion of the recess 233b may be welded, or the recess 233b may be welded and fixed by a plurality of spot welds or a plurality of spot-like fillet welds.

[0092] The welded portion 233d cannot be provided inside the inner diameter of the annular joint portion 111d of the valve body housing 111. This is because the fixing metal fitting 233 and the valve body housing 111 cannot come into contact with each other, making it impossible to weld and fix them. Furthermore, the welded portion 233d needs to be formed at a position where the weld bead 233w generated by welding to the valve body housing 111 does not interfere with the accommodating case 151.

[0093] Also, the protrusion 233a may be provided continuously around the entire circumference, or it may not be continuous around the entire circumference but may be interrupted into multiple parts along the way. In such a case, the contact surface of the guide portion 233c is at least located at an intersection of a line (N=an integer of 3 or more) dividing the circumference of the central axis of the fixing metal fitting into N equal parts at equal angles and a virtual circle similar to the virtual circle shown in FIG. 2(c).

[0094] However, when the protrusion 233a is provided around the entire circumference, the protrusion 233a has a circular shape, which makes manufacturing easier, and therefore reduces the number of manufacturing steps.

[0095] Furthermore, this embodiment can also be configured as follows, and such configurations are also within the scope of the present invention. For example, the stepped edge fixing fitting has a circular plate formed on the side of the accommodating case 151 to serve as a guide, and a small circular plate having a smaller diameter than this circular plate is formed integrally with the large circular plate and coaxially on the side of the valve body housing 111, and a weld is formed on the small circular plate.

[0096] As described above, the motor-operated valve 200 according to the second embodiment of the present invention also provides the same advantageous effects as the first embodiment, and also has the advantage of being able to reduce the number of manufacturing steps.

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

[0098] As described above, according to the present invention, in order to solve the above-mentioned conventional problems, it is possible to provide an electric valve and a refrigeration cycle system including the same, which can maintain coaxiality when fixing the valve body housing and the accommodating case with a simple component structure and enable reduction in manufacturing management. [Explanation of symbols]

[0099] CL center axis 11 First joint 12 Second joint 100, 200 Electric valve 110 Valve body 111 Valve body housing 111A Valve chamber 111b First port 111c second port 111d Joint 112 Valve seat 112a Valve port 120 Needle part 121 Needle 122 Valve spring 123 Spring holder 123a Spring engagement part 124 Washer 125 Needle Case 125a Open end 130, 230 Rotor shaft rotating part 131 Rotor shaft 131a Male thread 131b Flange part 132, 232 Female thread member 132A, 232A Guide Room 132b, 232b Female thread 132c, 232c pressure equalization hole 133, 133A, 133B, 133C, 233 Fixing bracket 133a, 133Aa, 133Ba1, 133Ba1, 133Ca, 233a convex part 133b, 133Ab, 133Bb, 133Cb, 233b recess 133c, 133Ac, 133Bc, 133Cc, 233c Guide part 133d, 133Ad, 133Bd, 133Cd, 233d Welded Sections 140 Rotor shaft drive unit 141 Magnet rotor 141A Rotor Room 141b Engagement protrusion 142 Rotor fixing member 143 Rotation stopper spring 144 Movable stopper member 150 Exterior part 151 Storage Case 151a Dimple 152 Rotor support member 152a Umbrella-shaped part 152b Cylindrical part 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 including a valve body that controls opening and closing of a valve port; an electromagnetic actuator including a rotor shaft and a magnet rotor for operating a drive mechanism that causes the valve body unit to perform an operation to control the valve body to approach or move away from the valve port so as to adjust the flow rate of a fluid passing between an end of the valve body and a periphery of the valve port; a female screw member that rotatably supports the rotor shaft; a valve body housing to which the female screw member is fixed; a fixing metal fitting having an outer peripheral edge portion protruding from an outer peripheral portion of the female threaded member in a direction perpendicular to a central axis of the rotor shaft, the fixing metal fitting being fixed to the female threaded member and welded to a peripheral edge of an opening upper surface of the valve body housing to fix the female threaded member; The electromagnetic actuator includes a rotor shaft and a magnet rotor, and a housing case for housing the rotor shaft and the magnet rotor. The fixing metal fitting includes a plurality of guide portions formed on an outer peripheral edge portion so as to be concentric with a central axis of the storage case, the guide portions each having an abutment surface protruding toward an inner peripheral surface of the storage case, the guide portions being spaced apart along a circumferential direction of the fixing metal fitting, the guide portions each having an abutment surface protruding toward an inner peripheral surface of the storage case, a plurality of recesses recessed in a direction toward the central axis of the fixing metal fitting relative to the abutment surfaces of the guide portions between the plurality of guide portions, and welds formed in the recesses, a welded portion welded to the upper opening surface of the valve body housing, wherein the outer diameter of the recess is larger than the inner diameter of the upper opening surface of the valve body housing, and the radial recess depths of the multiple recesses are the same.

2. The electric valve according to claim 1, characterized in that the abutment surfaces of the guide portions are formed so as to be on the circumference of a common imaginary circle centered on the central axis of the rotor shaft, and the diameter of the imaginary circle is set to be larger than the outer diameter of the magnet rotor and smaller than the inner diameter of the inner surface of the accommodating case.

3. 3. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to claim 1 or 2 is used as the expansion valve.

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