JP2004263841A - Electric control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric control valve of high pressure tightness specification, having superior pressure tightness and securing the sufficient airtight joining strength. <P>SOLUTION: A rotor case 31 and a lower lid member 2 are butted and welded by laser welding (W1, W2) over two rounds at different positions in the direction orthogonal to butt joining faces 31D, 23A of the rotor case 31 and the lower lid member 2. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric control valve, and more particularly to a high pressure resistant electric control valve used in a refrigeration cycle device using a CO ₂ refrigerant.
[0002]
[Prior art]
As an electrically operated valve used as a variable throttle valve or a flow control valve in a refrigeration cycle device or the like, a valve body for opening and closing a valve port is provided inside a valve housing, and the valve housing is, for example, fixed to a valve housing. A rotor case made of a non-magnetic material such as stainless steel is fixed to the lid member, a rotor of the stepping motor is rotatably arranged in the rotor case, and a stator coil of the stepping motor is attached to an outer periphery of the rotor case. 2. Description of the Related Art Electric control valves in which a valve body is driven to open and close by rotation are known (for example, Patent Documents 1 and 2).
[0003]
Further, among the above-described electric control valves, there is one in which a rotor case and a lower lid member are joined by TIG welding (for example, Patent Documents 3 and 4).
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-217853 [Patent Document 2]
JP-A-11-37311 [Patent Document 3]
JP-A-11-22849 [Patent Document 4]
Japanese Patent Application Laid-Open No. 2000-161520
[Problems to be solved by the invention]
In an electric control valve, the shape and thickness of the rotor case and the lower lid member that form the can of the closed container structure are calculated from the design pressure (fluid pressure) of the equipment used to improve airtightness and pressure resistance. It is necessary to increase their wall thickness and welding strength.
[0006]
Since the supercritical vapor compression refrigeration cycle device using the CO ₂ refrigerant is used in a state exceeding the criticality, the refrigerant pressure is higher than that of a general halocarbon (CFC) refrigerant. For this reason, in the case of the electric control valve used in the supercritical vapor compression refrigeration cycle device, the thickness of the rotor case and the lower lid must be increased to the design pressure, and the can shape and the rotor case as the optimal pressure vessel are required. Airtight joining with the lower lid member is required.
[0007]
Since the electric control valve used in the refrigeration cycle device using the halocarbon refrigerant does not require a very high pressure resistance, the thickness of the rotor case and the lower lid member may be relatively thin, and sufficient TIG welding or plasma welding may be used. Although the airtight joint strength can be secured, the electric control valve for the supercritical vapor compression refrigeration cycle device has a thicker rotor case and lower lid. As described above, a sufficient depth of the weld cannot be obtained, and a sufficient hermetic joint strength cannot be secured. In FIG. 12, reference numeral 100 denotes a lower lid member, and 101 denotes a rotor case.
[0008]
In order to obtain a sufficiently deep weld penetration by TIG welding or plasma welding, a large amount of welding heat is required, and the internal components may be deformed or damaged by the influence of heat.
[0009]
To cope with this, it is conceivable to join the rotor case 101 and the lower lid member 100 by laser welding. Laser welding can perform thick-wall butt welding with high directivity without diffusion due to the photothermal characteristics of the laser beam.
[0010]
However, on the other hand, in laser welding, the width of the weld bead shown by B in FIG. 13 is narrower than that of TIG welding or the like, and the rotor case 101 and the rotor case 101 caused by the processing accuracy of the lower lid member 100 and the like are not provided. If there is any relative displacement between the welding position (the position to be welded) and the laser welding position (the position of the laser nozzle of the welding device) due to variations in the welding position with the lower lid member 100, etc., the proper position of the welding bead B is determined. Is displaced from the butt joint surface C between the rotor case 101 and the lower lid member 100, and lacks stability to obtain sufficient mechanical strength and airtightness.
[0011]
The present invention has been made in order to solve the above-mentioned problems, and has a high pressure resistance specification in which a welded portion between a rotor case and a lower lid member has excellent pressure resistance, and a sufficient airtight joint strength is stably secured. The purpose of the present invention is to provide an electric control valve.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an electric control valve according to the present invention includes a valve housing having a valve port, a valve element for opening and closing the valve port, a lower lid member fixed to the valve housing, and a lower lid. It has a can-shaped rotor case fixed on a member, a rotor of an electric motor rotatably arranged in the rotor case, and a stator coil of the electric motor attached to an outer peripheral portion of the rotor case. In the electric control valve in which the valve body is driven to open and close by rotation of the rotor, the rotor case and the lower lid member are at least two times at different positions in a direction orthogonal to a butt joining surface of the two. Is butt-welded by laser welding.
[0013]
According to the electric control valve according to the present invention, the rotor case and the lower lid member are butt-welded by laser welding over at least two turns at different positions in a direction orthogonal to the butt-joint surface of the two. By utilizing the advantage of laser welding capable of performing thick butt welding, the problem of laser welding such as a narrow welding bead width can be solved by multi-circumferential welding at different positions. As a result, even when the rotor case and the lower lid member have high pressure resistance and a thick wall, both of them are butt-welded with sufficient hermetic joint strength.
[0014]
In the electric control valve according to the present invention, in addition to the fact that the weld bead of each circumferential welding of the laser welding is at a different position in a direction orthogonal to a butt joining surface between the rotor case and the lower lid member, A welding bead that is inclined with respect to a butt joining surface between the rotor case and the lower lid member may be included. In the case of the inclination, at least one turn of the weld bead inclined to one side with respect to the butt joint surface and at least another turn of the weld bead inclined to the other side with respect to the butt joint surface are included. And the overall penetration width (welding bead width) can be increased.
[0015]
In the electric control valve according to the present invention, as a detailed configuration, the lower lid member has a cylindrical wall portion to which the inner peripheral surface of the rotor case fits inside the butt joint surface. The cylindrical wall portion of the lower lid member determines the radial mounting position of the rotor case with respect to the lower lid member by fitting with the inner peripheral surface of the rotor case, and also butt-welds the rotor case and the lower lid member. Sometimes it acts as a barrier to prevent spatter from scattering into the interior of the rotor case.
[0016]
Electric control valve according to the invention described above is suitably used as a refrigerant flow control valve for the CO ₂ refrigerant refrigeration cycle device of a heat pump water heater or the like using the CO ₂ refrigerant.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows one embodiment of an electric control valve according to the present invention.
[0018]
An electric control valve according to the present invention is indicated generally by the reference numeral 10. The electric control valve 10 has a valve housing 11 made of a copper alloy or the like.
[0019]
The valve housing 11 has a valve chamber 12, an inlet port (lower port) 13 and an outlet port (lateral port) 14 communicating with the valve chamber 12. A valve seat member 15 and a lower joint pipe (inlet joint) 16 are sequentially inserted and fixed to the inlet port 13. A horizontal joint pipe (exit joint) 17 is inserted and fixed to the outlet port 14.
[0020]
The valve seat member 15 is made of a high-hardness material such as stainless steel or ceramic, and is formed through a valve port 18 communicating with the valve chamber 12. As shown in FIG. 7, the valve port 18 has a straight hole portion 18A for measuring a flow rate by a needle portion 20A of a valve body 20 to be described later, and a straightening portion continuous from the straight hole portion 18A to the inlet joint 16 side. And an opening end of the straight hole 18A with respect to the valve chamber 12 is formed as a diameter-enlarging portion 18C formed by chamfering a C hole.
[0021]
A valve support hole 19 is formed in the upper part of the valve housing 11 coaxially with the inlet port 13 with the valve chamber 12 therebetween. The stem portion 20B of the valve body 20 is fitted into the valve body support hole 19 so as to be slidable in the axial direction (the valve opening / closing direction).
[0022]
The valve body 20 is made of a hard material such as stainless steel or ceramic. A needle portion 20A is formed at the tip of the valve body 20, and the needle portion 20A cooperates with the straight hole portion 18A of the valve port 18 to control the flow rate.
[0023]
A cylindrical portion 21 for mounting a stepping motor is formed on an upper portion of the valve housing 11. An annular plate-shaped lower lid member 22 is brazed and fixed to an outer peripheral portion of the cylindrical portion 21. The lower lid member 22 has a cylindrical portion 23 on the upper side, and the upper surface thereof is a butt joining surface 23A with a rotor case 31 of a stepping motor 30 described later. A cylindrical wall portion 24 to which the inner peripheral surface of the rotor case 31 is fitted is formed inside the butt joint surface 23A of the lower lid member 22.
[0024]
A stepping motor 30 that drives the valve 20 to open and close is attached to an upper portion of the valve housing 11. The stepping motor 30 includes a rotor case 31, a rotor 32 provided in the rotor case 31, and a stator coil member 33 mounted on the outer periphery of the rotor case 31.
[0025]
The rotor case 31 has a can shape having a cylindrical portion 31A and a hemispherical dome portion 31B integrally formed with the cylindrical portion 31A and closing the upper end of the cylindrical portion 31A, and is entirely made of nonmagnetic material such as stainless steel having the same thickness. It is composed of the body.
[0026]
Since the rotor case 31 has a can shape closed by the hemispherical dome portion 31B, good pressure distribution is performed by the spherical surface, and the overall thickness of the rotor case 31 can be minimized with respect to the design pressure.
[0027]
In the rotor case 31, the inner peripheral surface of the lower annular opening edge 31C on the lower side of the cylindrical portion 31A is fitted concentrically with the outer peripheral surface of the cylindrical wall portion 24 of the lower lid member 22, and the tip of the annular opening edge 31C. The surface is a butt joint surface 31D that is opposed to and joins the butt joint surface 23A of the lower lid member 22.
[0028]
By the fitting of the cylindrical wall portion 24 of the lower lid member 22 and the annular opening edge 31C of the rotor case 31, the radial mounting position of the rotor case 31 with respect to the lower lid member 22 is correctly determined without any variation. .
[0029]
The lower lid member 22 and the rotor case 31 are air-tightly joined by butt welding of the butt joining surfaces 23A and 31D by laser welding. This butt welding will be described in detail after the description of the overall configuration of the electric control valve 10.
[0030]
The rotor 32 is rotatably arranged inside the cylindrical portion 31A of the rotor case 31. A multi-pole magnetized multi-pole magnet 34 is mounted on the outer periphery of the rotor 32.
[0031]
In the case of the high pressure resistant specification for the CO ₂ refrigerant, the rotor case 31 has a large thickness due to the required strength. Therefore, the spatial distance in the radial direction increases with the stator coil member 33 and the multi-pole magnet 34, because magnetic loss is large, by way of a high pressure resistance specification for CO ₂ refrigerant, a multi-pole magnet 34 ferrite sintered A rare earth magnet is used instead of the magnet. Further, by using the rare earth magnet as a plastic bond magnet, the weight can be reduced and the torque at the time of starting can be improved.
[0032]
A cylindrical female screw member 35 is fixed to the center of the rotor 32. The upper end of the stem portion 20B of the valve body 20 is connected to the female screw member 35 by a fixing bracket 36, a collar member 37, and a spring 38 so as to be relatively rotatable.
[0033]
A hollow shaft-shaped male screw member 39 through which the stem portion 20B of the valve body 20 penetrates is fixed to the upper central portion of the valve housing 11. A male screw 39A is formed on the outer peripheral surface of the male screw member 39. The male screw 39A is engaged with a female screw 35A formed on the inner peripheral surface of the female screw member 35.
[0034]
In this structure, when the rotor 32 is rotated by the driving of the stepping motor, the rotor 32 moves in the axial direction (vertical direction) in the rotor case 31 by the screw engagement between the female screw 35A and the male screw 39A, and the axial movement of the rotor 32 As a result, the valve element 20 moves in the axial direction (vertical direction). Thereby, the needle portion 20A enters and exits the straight hole 18A of the valve port 18, and the flow rate control determined by the axial position of the valve body 20 is performed.
[0035]
A stopper holding rod 40 is fixed to the inside of the hemispherical dome portion 31B. A spiral guide 41 is attached to the stopper holding rod 40, and a movable stopper 42 is engaged with the spiral guide 41. When the movable stopper 42 is kicked by the pin 43 attached to the rotor 32, the movable stopper 42 is guided by the helical guide 41 with the rotation of the rotor 32, and moves up and down while rotating, and the stopper portion 44 at the lower end of the stopper holding rod 40. Alternatively, the rotation of the rotor 31 in the valve closing direction or the valve opening direction is restricted by contacting the stopper 45 at the upper end of the spiral guide 41.
[0036]
Next, details of the butt welding between the lower lid member 22 and the rotor case 31 will be described with reference to FIG. The rotor case 31 and the lower lid member 22 are butt-welded by laser welding over two turns at different positions in a direction (axial direction) orthogonal to the butt-joint surfaces 31D and 23A. In FIG. 2, reference symbol W1 indicates a weld bead in the first cycle, and reference symbol W2 indicates a weld bead in the second cycle.
[0037]
The two-lap welding is performed by aligning the nozzle axis of the laser welding machine with a surface parallel to the butt joint surfaces 31D and 23A, and moving the nozzle in a direction perpendicular to the butt joint surfaces 31D and 23A.
[0038]
In this case, the weld bead W1 in the first lap and the weld bead W2 in the second lap have been translated in a direction perpendicular to the butt joint surfaces 31D and 23A, and have two laps with the weld bead W1 in the first lap. An axial deviation amount (a nozzle parallel movement amount) d is set so that the eye welding bead W2 partially overlaps in the parallel movement direction.
[0039]
Therefore, in the first round of laser welding, the center (the deepest part) of the weld bead W1 is located (（) d above the butt joint surfaces 31D and 23A, and in the second round of laser welding, the weld bead W2 is The center portion (the deepest portion) is positioned so as to be located (1/2) d below the butt joint surfaces 31D and 23A.
[0040]
Each of the first and second laser weldings is performed one or more times, for example, as shown in FIGS. As described above, the process is performed over a rotation angle range of 400 degrees including the forward travel (up slope) and the backward travel (down slope) of the nozzle of the laser welding machine. In FIGS. 3 and 4, (1) indicates laser welding in the first round, and (2) indicates laser welding in the second round. In the first and second rounds of laser welding, the welding start rotation angle positions are shifted by 180 degrees to each other so that the overlapped welding areas of the respective circles are generated at the positions shifted by 180 degrees from each other. Is set.
[0041]
As described above, the rotor case 31 and the lower lid member 22 are butt-welded by laser welding over two turns to a position where they are translated in a direction perpendicular to the butt-joint surfaces 31D and 23A of the two. Therefore, a wide bead width can be obtained by the entirety of the weld bead W1 in the first round and the weld bead W2 in the second round, while taking advantage of the characteristics of laser welding that can obtain a sufficient depth of the weld.
[0042]
The penetration depth of the welded portion is determined to an appropriate value according to the thickness of the rotor case 31 and the thickness of the lower lid member 22. This is determined by controlling the laser beam intensity (laser output) of laser welding. Can be set to a value.
[0043]
As a result, even when the rotor case 31 and the lower lid member 22 have a high pressure resistance and are resistant to a welding position error (variation), the two are butt-welded with sufficient hermetic joining strength.
[0044]
Further, the cylindrical wall portion 24 of the lower lid member 22 located inside the welded portion acts as a barrier for preventing spatters from scattering into the inside of the rotor case during laser welding. Since the cylindrical wall portion 24 has a sufficient thickness, the setting range of welding conditions for melting the case thickness (thickness of the rotor case 31 and the lower lid member 22) can be expanded.
[0045]
5 and 6 show another embodiment of the electric control valve according to the present invention. In this embodiment, the weld beads W1 and W2 of each circumference welding of the laser welding are inclined in different directions with respect to the butt joining surfaces 31D and 23A of the rotor case 31 and the lower lid member 22, respectively. That is, the first round of laser welding is performed at + θ degrees with respect to the butt-joint surfaces 31D and 23A, and with respect to the first-round weld bead W1 inclined to one side (downward) and the butt-joint surfaces 31D and 23A. The welding bead W2 of the second lap that is inclined to the other side (upper side) by θ degrees, the welding bead W1 of the first lap and the welding bead W2 of the second lap cross each other and partially overlap. ing.
[0046]
In this two-lap welding, the nozzle 50 is joined to the butt joint surfaces 31D and 23A so that the nozzle axis N of the laser welding machine is inclined at + θ degrees or −θ degrees with respect to a plane parallel to the butt joint surfaces 31D and 23A. It is performed by tilting and moving.
[0047]
In this embodiment as well, in the same manner as in the above-described embodiment, each of the first and second laser weldings is performed in one round so that a reliable airtightness in the welded portion is obtained and a sufficient pressure resistance is obtained. As described above, for example, as shown in FIGS. 3 and 4, the laser welding is performed over a rotation angle range of 400 degrees including a forward stroke (up slope) and a backward stroke (down slope) of the nozzle of the laser welding machine. ing. In the first and second rounds of laser welding, the welding start rotation angle positions are shifted by 180 degrees to each other so that the overlapped welding areas of the respective circles are generated at the positions shifted by 180 degrees from each other. Is set.
[0048]
Therefore, while taking advantage of the features of laser welding that can obtain a sufficient depth of the welded portion, a wide bead width can be obtained by the entirety of the weld bead W1 in the first round and the weld bead W2 in the second round. Even with the thick rotor case 31 and the lower lid member 22 which are resistant to positional errors (variations) and have high pressure resistance specifications, both of them are butt-welded with sufficient hermetic joint strength.
[0049]
Since the weld beads W1 and W2 in the first and second rounds are inclined at an inclination angle ± θ with respect to the butt joint surfaces 31D and 23A, the tolerance for the welding position error (variation) increases.
[0050]
The inclination angle ± θ depends on the thickness of the welded portion, but is preferably 0 to 30 degrees, and more preferably about 5 to 20 degrees. If the inclination angle is less than 5 degrees, the effect of expanding the allowable range of the welding position error due to the inclination of the weld bead with respect to the butt joint surface is not so much obtained, whereas if it is more than 20 degrees, it is shown in FIG. As described above, the necessary penetration depth D at the joint between the rotor case 101 and the lower lid member 100 becomes large, and accordingly, it becomes necessary to increase the amount of welding heat. Problems such as stress corrosion cracking occur.
[0051]
The butt welding between the rotor case 31 and the lower lid member 22 is not limited to the two-round welding described above, but may be a three-round or more round welding. Also in this case, welding of each circumference is performed by moving the nozzle in parallel in a direction orthogonal to the butt joint surfaces 31D and 23A. At that time, the weld bead of each circumference or a part of the weld bead may be inclined with respect to the butt joint surfaces 31D and 23A within the range of the inclination angle ± θ as described above. .
[0052]
Further, when inclining two or more rounds of the weld bead, two or more weld beads having different inclination directions with respect to the butt joint surfaces 31D and 23A may be included.
[0053]
FIG. 11 shows one embodiment of a refrigeration cycle apparatus using a CO ₂ refrigerant in which the electric control valve 10 according to the present invention is used.
[0054]
This refrigeration cycle apparatus is a heat pump water heater, in which a CO ₂ refrigerant circulation path including a compressor 71, a gas cooler 72 corresponding to a condenser, an electric control valve 10, and an evaporator 73 is formed. Heat is exchanged between the CO ₂ refrigerant and the cold water in the hot water tank 74 to create hot water.
[0055]
The electric control valve 10 is provided between the gas cooler 72 and the evaporator 73, and throttles and depressurizes the high-pressure CO ₂ refrigerant after the heat exchange and sends the refrigerant to the evaporator 73. Therefore, high-pressure CO ₂ refrigerant flows through the electric control valve 10, but since the components of the electric control valve 10 are high-pressure specifications as described above, no trouble occurs.
[0056]
Generally, in the CO ₂ cycle, the pressure difference between the high-pressure side and the low-pressure side of the high-pressure refrigerant is large. Therefore, a passing sound of the fluid passing through the valve port is also easily generated.
[0057]
In order to solve this, in the present embodiment, the lower joint pipe (inlet joint) 16 of the electric control valve 10 is connected to the gas cooler 72 on the high pressure side, and the horizontal joint pipe (outlet joint) 17 is connected to the evaporator 73 on the low pressure side. Connected to. Therefore, the high-pressure refrigerant passes through the valve port 18 from the lower joint pipe (inlet joint) 16 and flows straight into the valve chamber 12 without including a curved flow path. Thereby, the flow of the high-pressure refrigerant flows smoothly, and the fluid passage noise is reduced.
[0058]
Further, there is a rectifying tapered hole portion 18B which is continuous from the straight hole portion 18A of the valve port 18 to the lower joint pipe (inlet joint) 16 side, and the opening end of the straight hole portion 18A with respect to the valve chamber 12 is enlarged by C chamfering. The flow of the fluid can be made smooth by having the portion 18C. Thereby, the fluid passing sound can be reduced.
[0059]
Also, as shown in FIG. 8, the valve seat member 15 has an upper surface 15A protruding into the valve chamber 12, and the upper outer corner portion 15A is rounded. As shown in FIG. , The fluid flow can be smoothed and the fluid passing noise can be reduced. Further, as shown in FIG. 10, the taper hole 18B of the valve port 18 is made longer and the taper angle is made more gentle, so that the effect of reducing the passing sound of the fluid passing through the valve port 18 is increased. .
[0060]
In a high-pressure refrigerant such as a CO ₂ cycle, the pressure difference between the high-pressure side and the low-pressure side is much larger than that of a CFC-based refrigerant, and the state of the flowing refrigerant is supercritical, liquid phase, gas-liquid mixed flow, etc. Erosion such as erosion is likely to occur. In order to solve this problem, the needle valve (valve element 20) which reduces (= throttles) the pressure and the material of the valve seat member 15 are made of a high-hardness material such as stainless steel or ceramics. Can be reduced. By forming the valve seat member 15 separately from the valve housing 11 (copper alloy), it can be manufactured at low cost.
[0061]
【The invention's effect】
As can be understood from the above description, according to the electric control valve according to the present invention, the rotor case and the lower lid member are located at different positions in a direction orthogonal to the butt-joining surface of the two at least two times. Since butt welding is performed by laser welding, the problem of laser welding such as narrow welding bead width is solved by multi-circumferential welding at different positions, taking advantage of the advantage of laser welding that can perform thick butt welding. Even with a thick rotor case and a lower lid member having a pressure-resistant specification, both have a structure having a sufficient hermetic joint strength.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing one embodiment of an electric control valve according to the present invention.
FIG. 2 is an enlarged sectional view of a butt-welded portion between a rotor case and a lower lid member according to one embodiment.
FIG. 3 is an explanatory diagram showing a welding range of butt welding between a rotor case and a lower lid member.
FIG. 4 is a diagram showing a welding range of butt welding between a rotor case and a lower lid member.
FIG. 5 is a longitudinal sectional view showing another embodiment of the electric control valve according to the present invention.
FIG. 6 is an enlarged sectional view of a butt-welded portion between a rotor case and a lower lid member according to another embodiment.
FIG. 7 is an enlarged sectional view of a valve port portion according to one embodiment.
FIG. 8 is an enlarged sectional view of a valve port according to another embodiment.
FIG. 9 is an enlarged sectional view of a valve port according to another embodiment.
FIG. 10 is an enlarged sectional view of a valve port portion according to another embodiment.
FIG. 11 is a block diagram showing one embodiment of a refrigeration cycle apparatus using a CO ₂ refrigerant to which an electric control valve according to the present invention is applied.
FIG. 12 is an enlarged sectional view of a conventional butt-welded portion between a rotor case and a lower lid member.
FIG. 13 is an enlarged sectional view of a single circumferential butt weld between the rotor case and the lower lid member.
FIG. 14 is an enlarged sectional view of a single circumferential butt weld between the rotor case and the lower lid member.
[Explanation of symbols]
Reference Signs List 10 electric control valve 11 valve housing 12 valve chamber 15 valve seat member 16 lower joint pipe (inlet joint)
17 Horizontal joint pipe (exit joint)
18 Valve port 20 Valve element 22 Lower lid member 23 Cylindrical part 23A Butt joint surface 24 Cylindrical wall part 30 Stepping motor 31 Rotor case 31D Butt joint surface 33 Stator coil member

Claims (5)

A valve housing having a valve port, a valve body for opening and closing the valve port, a lower lid member fixed to the valve housing, a can-shaped rotor case fixed on the lower lid member, and An electric control valve comprising: a rotor of an electric motor rotatably disposed on the rotor case; and a stator coil of the electric motor mounted on an outer peripheral portion of the rotor case, wherein the rotation of the rotor drives the valve body to open and close. At
An electric control valve in which the rotor case and the lower lid member are butt-welded by laser welding over at least two turns at different positions in a direction orthogonal to a butt-joining surface of the both. 2. The electric control valve according to claim 1, wherein the laser-welded weld bead includes a weld bead that is inclined with respect to a butt joint surface between the rotor case and the lower lid member. 3. 3. The electric motor according to claim 2, comprising at least one round of the weld bead inclined to one side with respect to the butt joint surface, and at least another round of the weld bead inclined to the other side with respect to the butt joint surface. Control valve. The electric control valve according to any one of claims 1 to 3, wherein the lower lid member has a cylindrical wall portion to which an inner peripheral surface of the rotor case fits inside the butt joint surface. CO ₂ any one electric control valve according to claim 1 is a refrigerant flow rate control valve for a refrigeration cycle apparatus using the refrigerant.

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