JPH1122849A - Motor operated valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a crack of a can, a cover-shaped member and a joining sealing part on the basis of internal pressure of a refrigerant, and improve accuracy of concentricity, squareness or the like of these members by arranging an annular projecting piece on an upper surface of a valve main body, and arranging a welding groove extending in the radial outward direction from this annular projecting piece. SOLUTION: A valve main body 20, a can 32 and a cover-shaped member 33 to connect/fix this can 32 to the valve main body 20, are joined C by welding by forming a welding groove 20c in the valve main body 20. Therefore, even if a substitute refrigerant is supplied in the can 32, it can sufficiently endure long-term operating pressure, and joining C does not separate. The welding groove 20c is also formed in the valve main body 20, and the valve main body 20 is formed of a raw material such as brass as a block body having large mass. Therefore, even if blazing welding is performed, strain or the like is not caused, and since the welding groove is not formed in the cover-shaped member 33, work stress at fairing time for welding recessing does not remain, and even if welding is performed, strain is not caused in the cover member 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-operated valve used in a refrigeration cycle constituting a heat pump air conditioner, a refrigerator, or the like. The present invention relates to a motor-operated valve having an improved lid member connected to a main body and a valve body for fixing the lid member.

[0002]

2. Description of the Related Art FIG. 4 shows a conventional motor-operated valve of this type. Motorized valve 1 'in the illustrated example
Is basically a stepping motor 10 and a valve body 2
0, a rotor shaft 35, and a valve shaft 30. The rotor shaft 35 is rotationally driven by the stepping motor 10 to be moved up and down by screw feed. Thus, the flow rate is adjusted by opening and closing (changing the opening area) a fluid inlet / outlet (valve seat) 23 formed in the valve body 20.

[0003] The stepping motor 10 comprises a stator yoke 13 fitted on the outer periphery of a cylindrical can 11 fixedly connected to the valve body 20 via a lid 18.
, A bobbin 14, a magnet wire 15 wound around the bobbin 14 and energized from the outside, and a rotor 39 made of a bonded magnet fixed to a sleeve 40.

The valve body 20 has a valve chamber 21 and a fluid inlet / outlet 22 to which a conduit 24 communicating with the valve chamber 21 is connected.
A conduit 25 is connected to the bottom of the fluid inlet / outlet port 2 which is opened / closed by a valve body of the valve shaft 30.
3 are formed. Above the valve chamber 21 of the valve body 20, a guide bush 26 having a female screw portion formed on the inner periphery.
Are fixed inside.

The can 11 has a bottomed cylindrical shape, and has a lower flange 11a at an open end thereof. The lid 18 is formed as shown in FIGS. And an annular hole 18d in the bottom 18b and a flange 1 on the top.
8a, and has, for example, four radial welding grooves 18c on the back surface of the bottom portion 18a.

In order to assemble and fix the can 11, the lid 18 and the valve body 20, first, an inner hole 18 d of the lid 18 is fitted into an upper annular projecting piece 20 a of the valve body 20. The upper annular projecting piece 20a is crimped in the outer peripheral direction, and the outer peripheral upper part 2 of the valve body 20 is joined.
0b and the lower surface of the lid-like member 18 are subjected to brazing welding A. Then, after the guide bush 26, the rotor 39, the sleeve 40, the valve shaft 30, the shaft 35, and the like are stored in the can 11 and the lid member 18, the upper flange portion 18d of the lid member 18 and the can 11 Is brought into contact with the lower flange portion 11a, and the periphery thereof is subjected to pit welding B by TiG welding (tungsten inert gas welding) or the like, whereby the inside of the can 11 is sealed.

In the motor-operated valve 1 'having such a structure,
When the magnet wire 15 is energized and excited in one direction,
Rotor 39, sleeve 40, rotor shaft 35, holder 28
The valve shaft 30 is lowered by screw feed by screwing the female screw portion and the male screw portion, and the fluid inlet / outlet (valve seat) 23 is adjusted in the closing direction. Further, when the magnet wire 15 is energized in the other direction, the valve shaft 30 is raised to adjust the fluid inlet / outlet 23 in the opening direction.

[0008]

When the motor-operated valve 1 'is operated while being incorporated in a refrigeration cycle, the refrigerant is also supplied to the can 11 so that the inside of the can 11 is It is put under pressure by the refrigerant. For this reason, a dowel welding portion B such as TiG welding between the can 11 and the lid member 18 and a brazing weld portion A between the outer peripheral portion 21b of the valve body 20 and the lower surface of the lid member 18 are: The motor-operated valve 1 'must be able to withstand the long-term use of the refrigerant under pressure.

Further, in recent years, an old Freon-based refrigerant has been subject to regulation due to environmental problems such as destruction of the ozone layer due to Freon gas or the like. Therefore, an alternative refrigerant, for example, so-called R410A has been employed instead of the old refrigerant. ing. This alternative refrigerant operates at a high pressure (approximately 1.4 to 1.5 times) as compared with the conventional refrigerant. For this reason, during the operation of the motor-operated valve 1 ′, the use of the alternative refrigerant R410A also causes the inside of the can 11 to be in a higher pressure state than the conventional refrigerant, and the conventional refrigerant has no problem in its strength. The joining welding portion B and the brazing welding portion A must also have a structure that can withstand the high pressure state.

According to experiments conducted by the present inventors, the wedge joint welding portion B such as TiG welding between the can 11 and the lid-like member 18 of the conventional motor-operated valve 1 'is caused by the internal pressure of the refrigerant. Each of the can 11 and the lid 18 is
The lid member 1 receives the acting force in the opposite direction.
8 and the lower flange 11a of the can 11
Act in a direction away from each other about the point of action of the joint-welding portion B, which may cause a separation action in the joint-welding portion B.

[0011] The refrigerant in the can 11 during its operation,
Since the pressure changes alternately, the strength of the acting force is repeatedly changed. This means that a repeated stress acts on the point of application of the dovetailed welded portion B, and the welded beat of the dovetailed welded portion B fatigues due to the repeated stress, and a crack is generated in the weld beat. There is a fear. Further, the crack may grow due to the action of the repetitive stress, and eventually cause a problem that causes a malfunction in the operation of the electric valve 1 ′. In addition, this worship joint welding part B
Has been proposed in another patent application filed at the same time as the present application by the present applicant.

On the other hand, the brazed weld A between the outer peripheral portion 20b of the valve body 20 and the lower surface 18b of the lid 18 must also correspond to the high-pressure alternative refrigerant R410A. As shown in FIGS. 5 and 6, a conventional motor-operated valve 1 ′ includes an upper annular projecting piece 20 of the valve body 20.
a into the upper annular projecting piece 2
0a in the outer peripheral direction, and the outer peripheral portion 20b of the valve body 20 and the lower surface of the lid-like member 18 are welded by brazing A
Are formed on the lower surface 18b of the lid member 18, for example, four radially extending welding grooves 18c. In the welding A with brazing, the welding braid is connected to the upper annular projecting piece 2 through the welding grooves 18c,.
In this case, the welding strength of the brazed welding portion A is increased by entering the portion 0a.

However, the formation of the welding grooves 18c,.
Since it is performed by pressing or the like, the lid-like member 18
However, there arises a problem that working stress due to the press working remains. The residual processing stress is caused by the fact that the lid-like member 18 is used in the subsequent processing step by the brazing welding of the brazing welding A or the brazing joint welding portion B or the TiG.
There is a possibility that distortion may occur due to the influence of heat during welding. The occurrence of the distortion deteriorates the accuracy of the valve body 20, the lid-like member 18, and the can 11 in terms of coaxiality, squareness, and the like at the time of assembly and coupling, and as a result, the performance of the motor-operated valve 1 ' There is a risk of inhibition.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a can, lid-like member based on the internal pressure of a refrigerant without making large modifications to a conventional motor-operated valve. And, while preventing the possibility of cracking of the joint sealing portion of the valve body, the coaxiality of the member,
An object of the present invention is to provide a refrigeration cycle motor-operated valve that improves the accuracy of a right angle and the like.

[0015]

In order to achieve the above object, a motor-operated valve according to the present invention basically comprises a valve body, a bottomed cylindrical can, and a welded connection with the can. The valve body has an annular projecting piece on its upper surface and a welding groove extending radially outward from the annular projecting piece.

In a preferred specific embodiment of the motor-operated valve according to the present invention, the welding groove has a V-shape and is formed in a plurality in the circumferential direction, and the welding connection is brazing welding. The lid-like member is an annular flat plate, the inner hole of the annular flat plate is engaged with an annular projecting piece of the valve body, and the annular projecting piece is caulked outward, and the lower surface of the lid-like member is It is characterized in that the valve body is welded to the upper peripheral surface.

Further, the lid-shaped member has an upper step-shaped portion formed on the outer peripheral upper portion of the annular flat plate, and a lower step-shaped portion formed on the outer peripheral lower portion, and the opening of the can is formed in the upper step-shaped portion. It is characterized in that it is engaged and its engagement peripheral surface is joined by TiG welding.

In the motor-operated valve according to the present invention having the above-described structure, the welding between the lid-like member and the valve body is formed by forming a welding groove in the valve body, so that the valve can be replaced with a high-pressure valve. Even if the refrigerant R410A is supplied into the can, the refrigerant R410A can sufficiently withstand the long-term operating pressure, and the joint does not separate.

The welding groove is formed in the valve body,
Since the valve body is made of a material such as brass and formed as a large block body, even when brazing is performed, no distortion or the like occurs, and no welding groove is formed in the lid-like member. In addition, no processing stress during forming for forming a welding groove remains in the lid-like member, and no distortion occurs in the lid-like member even when welding is performed. Therefore, at the time of assembling and coupling, accuracy such as coaxiality and squareness of the valve body, the lid member, and the can can be improved, and the reliability and performance of the electric valve 1 ′ can be improved. .

Further, the joint welding portion between the can and the lid-shaped member is structured so that the end of the opening of the can is engaged with an upper step-shaped portion formed on the outer periphery of the lid-shaped member, and the periphery thereof is welded. Even if a high-pressure alternative refrigerant is supplied into the can, the can is received by the cylindrical opening with respect to the radial pressure of the alternative refrigerant, and As the pressure in the longitudinal direction (upward) of the substitute refrigerant is received as the tensile force of the welded portion,
Even if the joint is subjected to repeated stress during its operation by an alternative refrigerant having a higher pressure than the conventional refrigerant in the can, the repeated stress does not cause cracking. Further, by forming the step-shaped portion at the lower portion of the peripheral portion of the lid-like member, it is possible to eliminate a variation in the welding position and obtain a welded portion having high welding strength.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a motor-operated valve according to the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiment, components having the same functions as those of the conventional example will be denoted by the same reference numerals.

FIG. 1 is a longitudinal sectional view of a motor-operated valve 1 of the present embodiment. The motor-operated valve 1 shown in FIG. 1 basically includes a stepping motor 10, a valve body 20, a rotor shaft 35 and a valve shaft 30, and the rotor shaft 35 is rotated by the stepping motor 10. The valve element 31 of the valve shaft 30 that is driven to move up and down by screw feed, and moves up and down accordingly.
By opening and closing the fluid inlet / outlet 23 formed in the valve body 20 (by changing the opening area), the flow rate is adjusted.

The stepping motor 10 comprises a stator yoke 13 fitted on the outer periphery of a cylindrical can 32 fixedly connected to the valve body 20 via an annular flat cover member 33, a bobbin 14, Wound around the bobbin 14,
A magnet wire 15 energized from the outside, the stator yoke 13, the bobbin 14, and the magnet wire 15
, And a rotor 39 that is disposed inside the can 32 and is formed of a bonded magnet and fixed to a sleeve 40 described later.

The mold 12, the stator yoke 13,
The bobbin 14 and the magnet wire 15 are
Are integrally fitted on the outer periphery of the locking projection 17 of the pressing locking tool 17 attached to the mold 12 with screws 16.
a is fitted to the outer periphery of the can 32 in any one of four concave portions 19 provided at intervals of 90 degrees, for example, to perform positioning and retaining.

The valve body 20 has a valve chamber 21 and a fluid inlet / outlet 22 to which a conduit 24 communicating with the valve chamber 21 is connected.
A fluid inlet / outlet (valve seat) 23 which is opened and closed by a valve body 31 of the valve shaft 30 is formed. Above the valve chamber 21 of the valve body 20, a guide bush 26 having an internal thread 27 formed on the inner periphery is fixedly fitted.

An external thread portion 29 formed on the outer periphery of the holder 28 is screwed into the female thread portion 27 of the guide bush 26, and a valve shaft 30 with a flange is slidable on the lower inner peripheral portion of the holder 28. The holder 28 is inserted
A collar 34 for receiving the flange 30a of the valve shaft 30 is press-fitted and fixed at a lower portion of the valve shaft 30. The valve shaft 30 is constantly urged downward by a coil spring 37 compressed in the holder 28. . A rotor shaft 35 is fixedly fitted on the upper portion of the holder 28 so that the rotor shaft 35 can rotate integrally therewith. A movable stopper 45 having a convex shape is provided on the outer periphery of the upper portion of the holder 28 so as to project downward. It is molded and fixed so that it can rotate integrally with the sleeve 40 made of synthetic resin.

A coil spring 36 is mounted above the rotor shaft 35. In the coil spring 36, the rotor 39 is rotated (reversely rotated), and the rotor shaft 35, the sleeve 40, and the like are raised by screwing by screwing the female screw portion 27 and the male screw portion 29. When the screw 29 is disengaged, the holder 28 is pressed toward the guide bush 26 to facilitate re-screw.

On the outer periphery of the upper part of the guide bush 26,
A fixed receiving seat 50 made of synthetic resin and having a convex fixed-side stopper 55 to which the movable-side stopper 45 is brought into abutting contact is formed and fixed. The can 32,
It has a bottomed cylindrical shape with an opening 32a at one end,
The bottom (upper) 32b is formed in a spherical shape, and the opening 32a has an enlarged diameter.

As shown in FIGS. 2 and 3, the lid-like member 33 is formed as an annular flat plate, and has an internal hole 33a in which the upper annular projecting piece 20a of the valve body 20 is fitted.
And an upper stepped portion 33b on the outer periphery thereof.
And a lower step-shaped portion 33c.

Further, the valve body 20 has an upper annular projecting piece 20a on the upper surface thereof, and the upper annular projecting piece 20a is provided on the upper surface between the upper annular projecting piece 20a and the outer peripheral upper part 20b.
are formed, for example, four V-shaped welding grooves 20c,.

In order to assemble and fix the can 32, the lid member 33, and the valve body 20, first, the inner hole 33a of the lid member 33 is fitted into the upper annular projecting piece 20a of the valve body 20. The upper annular projecting piece 20a is swaged in the outer circumferential direction, and the outer circumferential portion 20
b and the lower surface of the lid-like member 33 are welded by brazing the entire outer periphery thereof.
I do. Thereafter, the guide bush 26, the rotor 39, and the sleeve 4 are provided in the can 32 and the lid member 33.
After housing the valve shaft 30, the rotor shaft 35, the rotor shaft 35, etc., the end of the opening 32a of the can 32 is engaged with the upper step-shaped portion 33b of the lid 33, and the periphery thereof is TiG welded (tungsten). Welding D is performed by inert gas welding or the like, whereby the inside of the can 11 is sealed.

In the brazing welding C, the welding brazing enters the upper annular protruding piece 20a through the welding grooves 20c and diffuses during the brazing welding, so that the welding grooves 20c and. , The welding strength of the brazed weld C is increased.

In the welding D, if the thickness of the lid 33 is larger than the thickness of the can 32 at the welded portion D, the heat mass of the lid 33 increases, At the time of TiG welding, the position of the penetration of the weld D is likely to vary, and as a result, the welded portion of the can 32 or the lid-like member 33 lacks one of the lengths from the joint thereof, There is a possibility that the joining strength may be low.

For this reason, in the present embodiment, in order to prevent variation in the penetration position of the welding D, a lower step-shaped portion 33c is formed below the lid-shaped member 33, and the lid-shaped member 33 is formed. By reducing the thickness of the outer peripheral part of
The heat mass of the lid-like member 33 is reduced to reduce the variation in the penetration position of the welding D during the TiG welding, and the length of the can 32 and the lid-like member 33 from the joint portion of the welding portion D is substantially reduced. They are the same. This allows
A welded portion D between the can 32 and the lid member 33 is a strong joint.

In the motor-operated valve 1 of this embodiment having such a configuration, when the magnet wire 15 is energized in one direction, the rotor 39, the sleeve 40, the rotor shaft 35,
The holder 28 and the like rotate integrally, and the valve shaft 30 is rotated by screwing the female screw portion 27 and the male screw portion 29 together.
Is lowered, and the fluid inlet / outlet 23 is closed by the valve element 31.

When the fluid inlet / outlet 23 is closed by the valve body 31, the movable-side stopper 45 has not yet come into contact with the fixed-side stopper 55, and the valve body 31 of the valve shaft 30 is connected to the fluid inlet / outlet. With the 23 closed, the holder 28 and the like are further rotated down. The valve shaft 30 at this time
Is lowered by the compression of the coil spring 37.

Thereafter, when the holder 28 and the like are further rotated down, the movable-side stopper 45 abuts against the fixed-side stopper 55, so that the energization to the rotor 39 is continued even if the energization to the rotor 39 is continued. 40, axis 3
5. The rotation and downward movement of the holder 28 and the like are forcibly stopped.

When the fluid inlet / outlet 23 is opened, the magnet wire 15 is energized in a direction opposite to the direction in which the fluid inlet / outlet 23 is closed, so that the valve 31 is rotated in the reverse direction so that the fluid inlet / outlet is closed. 23 is opened.

As described above, the motor-operated valve 1 of the present embodiment includes the valve body 20, the can 32, and the can 32 connected to the valve body 20.
And the lid-like member 33 connected and fixed to the valve body 20 has the above-described structure, and the joining welding C between the lid-like member 33 and the valve body 20 is performed.
Are formed in the valve body 20 and joined together, so that even if the alternative refrigerant is supplied into the can 32,
It can withstand the long-term working pressure sufficiently, and the joint C does not separate.

The welding grooves 20c,...
0, and the valve body 20 is made of a material such as brass, and is formed as a large block body.
3 does not have a welding groove, the lid-like member 33 has
There is no processing stress during forming for forming the welding groove, and no distortion occurs in the lid-like member 33 even when welding is performed.

Further, the can 32 and the lid 33
The welding portion between the can 32 and the upper stepped portion 33b formed on the outer periphery of the lid-like member 33 has an opening 32a of the can 32.
As a structure for engaging the end of the can 32, the periphery thereof is welded, so that even when the substitute refrigerant is supplied into the can 32, the can 32 is not affected by the radial pressure of the substitute refrigerant. It is received by the cylindrical opening 32a, and also receives the pressure in the longitudinal direction (upward) of the alternative refrigerant as the tensile force of the welded portion D. Even if the refrigerant is subjected to repeated stress during its operation by the substitute refrigerant having a higher pressure than that of the conventional refrigerant, no crack is generated by the repeated stress.

Further, the lid 33 is formed as an annular flat plate to withstand the operating pressure of the substitute refrigerant,
In the present embodiment, by forming the step-shaped portion 33c at the lower portion of the peripheral portion of the member 33, it is possible to eliminate a variation in the welding position and obtain a welded portion having high welding strength.

[0043]

As will be understood from the above description, the motor-operated valve of the present invention is formed by forming a welding groove in the valve body and joining the lid-like member and the valve body together. At the time of assembling and coupling, accuracy such as coaxiality and squareness of the valve body, the lid member, and the can can be improved, and the reliability and performance of the motor-operated valve can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a motor-operated valve according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a can of the motor-operated valve, a lid-like member, a valve body, and a welded joint shown in FIG.

FIG. 3 is an exploded perspective view of the can of the electric valve of FIG. 2, a lid-like member, and a valve body.

FIG. 4 is a sectional view showing an example of a conventional motor-operated valve.

FIG. 5 is an enlarged cross-sectional view showing a welded joint between a lid-like member and a valve body in the conventional electric valve of FIG.

FIG. 6 is an exploded perspective view of the can of the electric valve of FIG. 5, a lid-like member, and a valve body.

[Explanation of symbols]

 Reference Signs List 1 electric valve 10 stepping motor 20 valve body 20a upper annular projection 20c welding groove (V-shaped) 23 fluid inlet / outlet 30 valve shaft 32 can 32a opening 33 lid-like member 33a internal hole 33b upper annular stepped portion 33c lower annular Stepped part C Welded part with solder D TiG welded part

Claims (6)

[Claims] 1. A motor-operated valve comprising: a valve body; a bottomed tubular can; and a lid-like member fixedly attached to said valve body by welding to said can. A motor-operated valve comprising an annular projecting piece on an upper surface and a welding groove extending radially outward from the annular projecting piece. 2. The lid-shaped member is an annular flat plate, an inner hole of the annular flat plate is engaged with an annular projecting piece of the valve body, and the annular projecting piece is caulked outwardly, The motor-operated valve according to claim 1, wherein a lower surface of the member is welded to an upper peripheral surface of the valve body. 3. The motor-operated valve according to claim 1, wherein a plurality of the welding grooves are V-shaped and formed in a circumferential direction. 4. The motor-operated valve according to claim 1, wherein the welding connection is brazing welding. 5. The lid-shaped member according to claim 1, wherein an upper step-shaped portion is formed at an upper portion of an outer periphery of the annular flat plate, and a lower step-shaped portion is formed at a lower portion of the outer periphery of the annular plate. Motorized valve as described. 6. The lid-like member according to claim 1, wherein an opening of the can is engaged with an upper step-shaped portion of the lid, and the engaging peripheral surface is joined by TiG welding. An electric valve according to one of the preceding claims.