JP6933398B2 - Electric valve - Google Patents

Description

The present invention relates to an electric valve used as a flow control valve or the like in a refrigerating cycle of an air conditioner, a refrigerator or the like, and in particular, a screw feed mechanism composed of a male screw portion and a female screw portion is used to rotate a motor. The present invention relates to an electric valve of a type that raises and lowers a valve body by converting it into a linear motion.

For example, in a motor-driven electric valve, the rotary motion of the motor is converted into a linear motion by a screw feed mechanism composed of a male threaded portion and a female threaded portion, so that the valve body is raised and lowered with respect to the valve seat. It opens and closes (that is, controls the flow rate of the fluid (refrigerant) passing through the valve port).

Examples of this type of electric valve include a valve shaft provided with a valve body at the lower end portion and a guide bush having a cylindrical portion inserted in a state in which the valve shaft is relatively movable and relatively rotatable in the axial direction. A valve body having a valve seat portion (valve seat) to which the valve body is brought into contact with and detached from the valve body and to which the guide bush is attached and fixed, a cylindrical portion into which the guide bush is inserted, and an upper end portion of the valve shaft are inserted. Between the valve shaft holder which has a ceiling portion through which an insertion hole is formed and is connected and fixed to the valve shaft, and the valve shaft and the valve shaft holder so as to urge the valve body in the valve closing direction. A motor having a biasing member interposed therein, a rotor and a stator for rotating the valve shaft holder with respect to the guide bush, and a fixing screw portion (male screw portion) formed on the outer periphery of the guide bush. It is composed of a movable screw portion (female screw portion) formed on the inner circumference of the valve shaft holder, and the valve body of the valve shaft is raised and lowered with respect to the valve seat portion (valve seat) in response to the rotational drive of the rotor. A screw feed mechanism for causing the valve shaft holder, a fixing stopper body provided on a lower stopper having a female screw portion screwed to the fixing screw portion of the guide bush, and the fixing stopper body for restricting the downward movement of the valve shaft holder. A lower stopper mechanism including a movable stopper body provided on the valve shaft holder is provided, and when the valve body is in the lowest position, a predetermined position is provided between the valve body and the valve seat portion (valve seat). It is known that a gap having the size of is formed (see, for example, Patent Document 1).

In an air conditioner using a valve closing-less type electric valve as described above, a gap of a predetermined size is provided between the valve body and the valve seat even when the valve body is in the lowest position (normally fully closed). Therefore, for example, when the dehumidifying operation is performed at midnight, the operation can be performed with the amount of refrigerant reduced without closing the electric valve fully, and the generation of operating noise due to the on / off of the electric valve is suppressed. be able to. Further, the electric valve as described above has an advantage that the valve body can be reliably prevented from biting into the valve seat as compared with the normal closed type electric valve.

In addition, as a screw feed mechanism for raising and lowering the valve body with respect to the valve seat, it is already known that a male screw portion formed on the outer circumference of the valve shaft and a female screw portion formed on the inner circumference of the guide bush are used. (See, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2016-217451 Japanese Unexamined Patent Publication No. 2016-0898770

By the way, in this type of electric valve, when a foreign substance is caught between the male threaded portion and the female threaded portion (between the threaded surfaces) constituting the screw feeding mechanism, the sliding resistance increases and the valve shaft becomes difficult to move. Defects may occur.

Further, in recent years, with the reduction of cost and weight, the number of cases where a resin material such as PPS is used for a part having a male screw portion and a female screw portion constituting a screw feed mechanism is increasing. In this case, it is conceivable to manufacture the part having the male-threaded portion and the female-threaded portion described above by molding with a split mold having good molding efficiency. However, when molding with a split mold is adopted, the parting line or weld line (the place where it occurs depends on the gate position, but the materials collide with each other during molding) on the sliding surface (thread surface) of the male and female threads. There is a concern that problems such as swelling and short circuits where the material does not reach sufficiently) will occur, which will hinder sliding and reduce operability.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric valve capable of suppressing a decrease in operability.

In order to solve the above-mentioned problems, the electric valve according to the present invention basically includes a valve body having a valve opening with a valve seat in which the valve body is brought in and out, a valve shaft provided with the valve body, and the above. A can fixed to the valve body, an inner space through which the refrigerant flows is formed, a rotor that rotates together with the valve shaft, and a stator that is arranged on the outer periphery of the can and rotates the rotor with respect to the valve body. And a screw feed mechanism having a male screw portion and a female screw portion for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body in response to the rotation of the rotor, and the inner space. Is communicated with the space on the upper end side of the rotor and inside the can, and at least one of the male threaded portion and the female threaded portion is provided with a longitudinal groove extending over the entire length in the ascending / descending direction so that the refrigerant flows through the longitudinal groove. The longitudinal groove is configured and is characterized in that it extends to a portion communicating with the inner space on the upper side of at least one of the male screw portion and the female screw portion in the elevating direction.

In a preferred embodiment, the male threaded portion and the female threaded portion are provided between the guide bush into which the valve shaft is inserted and the valve shaft holder connected to the valve shaft, and the longitudinal groove is formed by the male threaded portion or the above. It extends over the entire length of the wall surface of the guide bush or the valve shaft holder provided with the female thread portion in the ascending / descending direction.

In another preferred embodiment, the longitudinal groove is composed of a concave surface provided on the female thread portion.

In another preferred embodiment, the longitudinal groove is composed of a concave surface or a D-cut surface provided on the male threaded portion.

In another preferred embodiment, the longitudinal groove is formed along the parting line or weld line of the male threaded portion or the female threaded portion.

According to the present invention, since at least one of the male threaded portion and the female threaded portion constituting the screw feed mechanism is provided with a longitudinal groove extending over the entire length in the ascending / descending direction, the male threaded portion and the female threaded portion do not mesh with each other over the entire length in the ascending / descending direction. The fluid (refrigerant) flows smoothly through the longitudinal groove, which is a portion (the portion where the screw surfaces are not in contact with each other), and foreign matter entering between the male screw portion and the female screw portion (between the screw surfaces) is concerned. Since it can be positively discharged through the longitudinal groove, the risk of biting can be reduced and the deterioration of operability can be suppressed.

Further, even if a foreign substance is caught between the male threaded portion and the female threaded portion (between the threaded surfaces), the foreign matter is moved by the relative rotation between the male threaded portion and the female threaded portion, and the male threaded portion and the female threaded portion are engaged with each other. Since the foreign matter is discharged from the vertical groove, it is possible to reliably suppress the deterioration of operability.

Further, since a longitudinal groove composed of a concave surface or a D-cut surface is formed along the parting line or weld line of the male threaded portion or the female threaded portion, the sliding is not hindered by them, and the operability is deteriorated. It can be suppressed more reliably.

The vertical sectional view which shows the 1st Embodiment of the electric valve which concerns on this invention. The valve shaft holder shown in FIG. 1 is shown, (A) is a perspective view, and (B) is a top view. FIG. 5 is a cross-sectional view taken along the line of sight of the UU arrow in FIG. FIG. 3 is a cross-sectional view showing the valve shaft holder shown in FIG. 1 according to the line of sight of the arrow VV of FIG. The vertical sectional view which shows the 2nd Embodiment of the electric valve which concerns on this invention. FIG. 5 is a cross-sectional view taken along the line of sight of the UU arrow in FIG. FIG. 5 is a cross-sectional view showing the valve shaft holder shown in FIG. 5 according to the VV arrow line of sight of FIG. The vertical sectional view which shows the 3rd Embodiment of the electric valve which concerns on this invention. FIG. 8 is a cross-sectional view taken along the line of sight of the arrow UU in FIG. The left side view which shows the guide bush shown in FIG. The vertical sectional view which shows the 4th Embodiment of the electric valve which concerns on this invention. FIG. 11 is a cross-sectional view taken along the line of sight of the arrow UU in FIG. The left side view which shows the guide bush shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In each drawing, the gaps formed between the members, the separation distance between the members, etc. may be exaggerated in order to facilitate understanding of the invention and for convenience in drawing. be. Further, in the present specification, the description indicating the position and direction such as up and down, left and right, etc. is based on the direction arrow display as shown in FIG. 1, and does not indicate the position and direction in the actual use state.

[First Embodiment]
FIG. 1 is a vertical sectional view showing a first embodiment of an electric valve according to the present invention.

The electric valve 1 of the illustrated embodiment is used by being incorporated as a flow rate control valve or the like in a refrigerating cycle of an air conditioner, a refrigerator or the like, and is mainly used by a valve shaft 10 provided with a valve body 14 and a guide. A bush 20, a valve shaft holder 30, a valve body 40, a can 55, a stepping motor 50 including a rotor 51 and a stator 52, a compression coil spring (biasing member) 60, and a fixing member 70 as a stopper. , A screw feed mechanism 28 and a lower stopper mechanism 29 are provided.

The valve shaft 10 has an upper small diameter portion 11, an intermediate large diameter portion 12, and a lower small diameter portion 13 from the upper side, and a fluid (refrigerant) flowing through the valve port 46 at the lower end portion of the lower small diameter portion 13. A stepped inverted conical valve body 14 for controlling the passing flow rate of the valve body 14 is integrally formed.

The guide bush 20 is made of resin, for example, and is inserted in a state in which the valve shaft 10 (intermediate large diameter portion 12) can move (slide) relative to the axis O and can rotate relative to the axis O. The cylindrical portion 21 and the upper end portion of the cylindrical portion 21 extend upward and have an inner diameter larger than that of the cylindrical portion 21, and are on the upper end side of the intermediate large diameter portion 12 of the valve shaft 10 and the lower end side of the upper small diameter portion 11. It has an extension portion 22 in which and is inserted. On the outer circumference of the cylindrical portion 21 of the guide bush 20, one of the screw feed mechanisms 28 that raises and lowers the valve body 14 of the valve shaft 10 with respect to the valve seat 46a of the valve body 40 in response to the rotational drive of the rotor 51 is configured. A fixing screw portion (male screw portion) 23 is formed. Further, the lower portion of the cylindrical portion 21 (the portion below the fixing screw portion 23) has a large diameter, and is a fitting portion 27 into the fitting hole 44 of the valve body 40. A lower stopper 25 is screwed to the fixing screw portion 23 (below the valve shaft holder 30 in the fixing screw portion 23), and a lower stopper that regulates the rotation downward movement of the valve shaft holder 30 is applied to the outer circumference of the lower stopper 25. The fixed stopper body 24 constituting one of the mechanisms 29 is integrally projected. In this example, the upper surface 27a of the fitting portion 27 is a stopper portion that regulates the downward movement of the lower stopper 25 (in other words, defines the position of the lower stopper 25 in the seated state described later).

Further, in this example, the stopper retainer 48 is attached to the lower stopper 25 attached to the guide bush 20 (fixing screw portion 23), and the stopper retainer 48 causes the lower stopper 25 to be the guide bush 20 (of the guide bush 20). It is non-rotatably connected to the fixing screw portion 23) (detailed later).

The valve shaft holder 30 is made of, for example, a resin (preferably made of a resin reinforced with SUS, carbon fiber, or the like having high wear resistance in consideration of contact with the fixing member 70), and the guide bush 20 is An insertion hole 32a through which the cylindrical portion 31 to be inserted and the upper end portion of the valve shaft 10 (upper small diameter portion 11) are inserted (in a state where they can move relative to the axis O and rotate relative to the axis O) penetrate. It has a ceiling portion 32 provided. A movable screw portion (female screw portion) 33 that is screwed with the fixing screw portion 23 of the guide bush 20 to form the screw feed mechanism 28 is formed in the lower part of the inner circumference of the cylindrical portion 31 of the valve shaft holder 30. There is. Further, the upper portion of the inner circumference of the cylindrical portion 31 is brought into contact (sliding contact) with the outer circumference of the cylindrical extending portion 22 of the guide bush 20, whereby the valve shaft holder 30 is brought into contact with the outer circumference of the guide bush 20 (the outer circumference of the guide bush 20). ), It can be moved up and down in the O direction (vertical direction) of the axis. Further, a movable stopper body 34 constituting the other side of the lower stopper mechanism 29 is integrally projected from the lower end of the outer circumference of the cylindrical portion 31.

Further, on the upper surface of the ceiling portion 32 of the valve shaft holder 30 (the surface facing the flange portion 72 of the fixing member 70 described later), as can be clearly seen by referring to FIG. 2 together with FIG. 1, in a plan view (axis line). Two convex portions 35 having a substantially fan shape (here, a fan shape having a central angle of about 90 degrees) are integrally formed (when viewed in the O direction). Specifically, the two convex portions 35 are located on the upper surface of the ceiling portion 32 around the insertion hole 32a (in other words, around the rotation axis O of the valve shaft holder 30) and on the opposite side of the axis O (in other words, the valve shaft). It is projected upward (at a position symmetrical with respect to the rotation axis O of the holder 30), and in the meantime (in this example, an upper portion of one end surface 34a in the circumferential direction of the movable stopper body 34, that is, the axis O direction). The movable stopper body 34 has a shape in which one end surface 34a in the circumferential direction is cut out when viewed from the above (a substantially fan shape in a plan view (here, the central angle is about about). 90 degree fan shape) notch 36).

Since the contact area of the valve shaft holder 30 with respect to the fixing member 70 is reduced by the convex portion 35, for example, the contact resistance (rotational sliding resistance) when the valve shaft holder 30 comes into contact with the fixing member 70 is reduced.

Further, for example, when the valve shaft holder 30 is made of a molded product such as resin, the positions of the weld line and parting line formed at the time of molding are aligned with the position of the notch 36, that is, the weld is formed at the time of molding. By providing the notch 36 at the position where the line or parting line is formed, the contact resistance (rotational sliding resistance) can be further reduced, and the flatness of the sliding surface of the valve shaft holder 30 is increased. The misalignment of the valve shaft 10 can be further suppressed.

For example, when a gate for injecting a molding resin is provided on the opposite side of the movable stopper body 34 in the valve shaft holder 30, as described above, above the movable stopper body 34 (more specifically, the movable stopper). By providing the notch 36 in the upper portion of the one end surface 34a in the circumferential direction of the body 34), the weld line and the parting line formed at the time of molding do not exist in the convex portion 35 of the valve shaft holder 30. The contact resistance (rotational sliding resistance) can be further reduced, the flatness of the sliding surface of the valve shaft holder 30 can be increased, and the shaft deviation of the valve shaft 10 can be further suppressed.

Further, by arranging the convex portion 35 symmetrically with respect to the rotation axis O of the valve shaft holder 30 on the upper surface of the ceiling portion 32 of the valve shaft holder 30, the axial deviation of the valve shaft 10 can be suppressed more effectively. By arranging the convex portions 35 in a plurality of locations around the rotation axis O of the valve shaft holder 30, the contact area of the valve shaft holder 30 (convex portion 35) with respect to the fixing member 70 can be further reduced. Is possible.

It goes without saying that the shape, number, position, etc. of the convex portions 35 provided on the upper surface of the ceiling portion 32 of the valve shaft holder 30 are not limited to the illustrated examples, and the convex portions 35 may be omitted. good.

Further, between the terrace surface (step portion) 15 formed between the upper small diameter portion 11 of the valve shaft 10 and the intermediate large diameter portion 12 and the lower surface of the ceiling portion 32 of the valve shaft holder 30, the said. The valve shaft 10 and the valve shaft 10 and the valve shaft 10 and the said A cylindrical compression coil spring that urges the valve shaft holder 30 in a direction away from the valve shaft holder 30 in the elevating direction (axis O direction), in other words, always urges the valve shaft 10 (valve body 14) downward (valve closing direction). (Biasing member) 60 is reduced.

The valve body 40 is made of a metal cylinder such as brass or SUS. The valve body 40 has a valve chamber 40a into which a fluid is introduced and led out, and a first conduit 41a is connected and fixed to a lateral first opening 41 provided on a side portion of the valve chamber 40a by brazing or the like. An insertion hole is inserted into the ceiling of the valve chamber 40a so that the valve shaft 10 (intermediate large diameter portion 12) can move (slide) relative to the axis O and can rotate relative to the axis O. A fitting hole 44 is formed by fitting the lower portion (fitting portion 27) of the guide bush 20 and the guide bush 20 to be mounted and fixed, and a second opening 42 in the vertical direction provided in the lower portion of the valve chamber 40a is provided. 2 The conduit 42a is connected and fixed by brazing or the like. Further, a stepped valve opening 46 having a valve seat 46a with which the valve body 14 is brought into contact with and separated from the valve chamber 40a is formed on the bottom wall 45 between the valve chamber 40a and the second opening 42.

An annular flange plate 47 is crimped and fixed to the outer periphery of the upper end of the valve body 40 by brazing or the like, and a cylindrical can with a ceiling is attached to a step portion provided on the outer periphery of the flange plate 47. The lower end of 55 is hermetically sealed by butt welding or the like.

Further, in this example, a stopper retainer 48 that engages with the lower stopper 25 to prevent the lower stopper 25 from rotating relative to the guide bush 20 is arranged on the upper surface (the surface on the can 55 side) of the flange plate 47. It is fixed.

The stopper retainer 48 is made of a disk-shaped member manufactured by press working or the like from a metal member such as brass or SUS, and an insertion / insertion hole through which the lower stopper 25 is inserted is formed, and the insertion / insertion hole is formed. A plurality of support claws 49 (two of which are shown in FIG. 1) that sandwich the lower stopper 25 (outer surface) stand adjacent to the hole (in other words, on the outer peripheral portion of the fitting hole). (For the detailed structure, refer to, for example, Patent Document 1 above).

The outer peripheral portion of the stopper retainer 48 is brought into contact with the flange plate 47 (upper surface) and joined and fixed by welding, welding, adhesion, etc., so that the lower stopper 25 is a guide bush 20 (fixing screw portion). It is connected so that it cannot rotate relative to 23).

A rotor 51 is rotatably arranged inside the can 55 and outside the guide bush 20 and the valve shaft holder 30, and a yoke 52a, A stator 52 composed of a bobbin 52b, a stator coil 52c, a resin mold cover 52d, and the like is arranged. A plurality of lead terminals 52e are connected to the stator coil 52c, and a plurality of lead wires 52g are connected to these lead terminals 52e via the substrate 52f, and are arranged in the can 55 by energizing the stator coil 52c. The existing rotor 51 rotates around the axis O.

The rotor 51 arranged in the can 55 is engaged and supported by the valve shaft holder 30, and the valve shaft holder 30 rotates (integrally) with the rotor 51.

Specifically, the rotor 51 has a double pipe configuration including an inner cylinder 51a, an outer cylinder 51b, and a connecting portion 51c that connects the inner cylinder 51a and the outer cylinder 51b at a predetermined angle position around the axis O. A vertical groove 51d extending in the axis O direction (vertical direction) is formed on the inner circumference of the inner cylinder 51a (for example, at an angle interval of 120 degrees around the axis O).

On the other hand, on the outer circumference (upper half portion) of the valve shaft holder 30, as can be clearly seen with reference to FIG. 2, a tapered surface portion 30c made of a conical base surface is provided at the upper end thereof, and the lower side of the tapered surface portion 30c. A ridge 30a extending in the vertical direction is provided so as to extend in the vertical direction (for example, at an angle interval of 120 degrees around the axis O), and upward locking surfaces 30b for supporting the rotor 51 are provided on both lower sides of the ridge 30a. Is formed.

In this way, the vertical groove 51d of the inner cylinder 51a of the rotor 51 and the ridge 30a of the valve shaft holder 30 are engaged, and the lower surface of the inner cylinder 51a of the rotor 51 and the locking surface 30b of the valve shaft holder 30 are engaged with each other. By abutting, the rotor 51 is supported and fixed to the outer periphery of the valve shaft holder 30 in a state of being aligned with the valve shaft holder 30, and the valve shaft holder 30 supports the rotor 51 in the can 55 while supporting the rotor 51. It is rotated with.

In this example, the rotor 51 is engaged and supported by the valve shaft holder 30 so that the upper surface of the valve shaft holder 30 is flush with or slightly above the upper surface of the inner cylinder 51a of the rotor 51. There is.

On the upper side of the rotor 51 and the valve shaft holder 30, the relative movement of the valve shaft holder 30 and the rotor 51 in the ascending / descending direction is prevented (in other words, the rotor 51 is pressed downward against the valve shaft holder 30 to prevent it from coming off. A fixing member 70 that is externally fitted and fixed is arranged at the upper end of the valve shaft 10 (upper small diameter portion 11) so as to connect the valve shaft 10 and the valve shaft holder 30 together with (locking).

The fixing member 70 is manufactured from a metal member such as brass or SUS by press working, cutting, or the like, and is externally fitted to the upper end portion of the valve shaft 10 (upper small diameter portion 11) to be press-fitted, welded, or welded. A stepped cylindrical fixing portion 71 composed of a small diameter upper portion 71a and a large diameter lower portion 71b joined and fixed by adhesion or the like, and an inner cylinder 51a of the rotor 51 from the lower end portion of the fixing portion 71 (the large diameter lower portion 71b). It has a disk-shaped flange portion 72 extending outward to the vicinity.

The lower surface of the flange portion 72 is opposed to the upper surface of the valve shaft holder 30 and the upper surface of the rotor 51 (inner cylinder 51a), and the convex portion 35 (upper surface) provided on the upper surface of the valve shaft holder 30. And the rotor 51 (the upper surface of the inner cylinder 51a) are brought into contact with each other.

As described above, the rotor 51 is sandwiched between the valve shaft holder 30 that is urged upward by the urging force of the compression coil spring 60 and the fixing member 70 (the outer peripheral portion of the flange portion 72) to prevent it from coming off. Locked.

Further, the valve shaft holder 30 moves too much upward with respect to the guide bush 20 during operation of the fixing member 70 (the large-diameter lower portion 71b of the fixing portion 71) fixed to the upper end portion of the valve shaft 10. , A return spring composed of a coil spring that urges the valve shaft holder 30 toward the guide bush 20 in order to prevent the fixing screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30 from being disengaged. 75 is exterior.

Then, in the electric valve 1, for example, the valve body 14 is in the lowest descending position (origin position) in order to prevent the valve body 14 from biting into the valve seat 46a and to ensure controllability in a low flow rate range. Occasionally, a gap of a predetermined size is formed between the valve body 14 and the valve seat 46a.

The process of assembling the electric valve 1, particularly the process of setting the origin position (minimum lowering position) of the valve body 14, will be described in detail. First, the valve shaft 10, the guide bush 20, the lower stopper 25, the compression coil spring 60, and the valve shaft holder 30. , Rotor 51, valve body 40, flange plate 47, etc. are assembled. For example, the flange plate 47 is brazed to the valve body 40, the guide bush 20 is press-fitted and fixed to the valve body 40, and then the lower stopper 25 is screwed to the guide bush 20 (fixing screw portion 23). Assemble. At this time, the lower stopper 25 is screwed with respect to the guide bush 20 so as to be relatively rotatable. At this stage, the lower stopper 25 may be arranged in contact with the stopper portion 27a of the guide bush 20, or may be arranged at a distance from the stopper portion 27a. Next, the valve body 14 provided at the lower end of the valve shaft 10 contacts (seats) the valve seat 46a, the compression coil spring 60 is slightly compressed, and the movable stopper body 34 of the valve shaft holder 30 and the lower stopper 25 The fixing screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30 until the fixed stopper body 24 comes into contact with the stopper body 24 and the lower stopper 25 (lower surface) comes into contact with the stopper portion 27a of the guide bush 20. The valve shaft holder 30, the rotor 51, and the valve shaft 10 are lowered while being rotated by using the screw feed mechanism 28 composed of the screw feed mechanism 28. Then, with the valve shaft holder 30 arranged at the lowest position in this way, the fixing member 70 is externally fitted and fixed to the upper end of the valve shaft 10 by press fitting, welding, welding, adhesion, or the like (seated state).

Next, from the seated state, the assembly in which the valve shaft 10, the valve shaft holder 30, the rotor 51, the fixing member 70, and the like are integrated is raised while being rotated by using the screw feed mechanism 28, and the guide bush is used. After removing from 20, the stopper retainer 48 is placed on the valve body 40 and the flange plate 47 while being exteriorized on the lower stopper 25 by dropping from above, and the lower stopper 25 is placed on the guide bush 20 together with the stopper retainer 48. It is rotated by a predetermined rotation angle in the valve opening direction (for example, counterclockwise in a plan view). Then, the stopper retainer 48 is joined and fixed to the flange plate 47 of the valve body 40 by welding, welding, adhesion, etc., and the lower stopper 25 is connected and fixed to the guide bush 20 (fixing screw portion 23) so as not to rotate relative to each other. After that, the assembly is assembled to the guide bush 20 again by using the screw feed mechanism 28. As a result, the position of the fixed stopper body 24 of the lower stopper 25 with respect to the guide bush 20 changes, so that the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 come into contact with each other, and the valve shaft holder 30 is moved. Even when it is in the lowest lowered position, a gap having a predetermined size is formed between the valve body 14 and the valve seat 46a.

Before mounting the stopper retainer 48 on the lower stopper 25, the lower stopper 25 is rotated with respect to the guide bush 20 by a predetermined rotation angle in the valve opening direction, and then the stopper retainer 48 is mounted on the lower stopper 25 to valve the valve. It may be joined and fixed to the brim-shaped plate 47 of the main body 40.

In the electric valve 1 having such a configuration, when the rotor 51 is rotated by energizing the stator 52 (stator coil 52c), the valve shaft holder 30 and the valve shaft 10 are rotated integrally with the rotor 51. At this time, the valve shaft 10 is moved up and down with the valve body 14 by the screw feed mechanism 28 including the fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30, thereby causing the valve body 14 to move up and down. The gap (lift amount, valve opening degree) between the valve seat 46a and the valve seat 46a is increased or decreased to adjust the passing flow rate of a fluid such as a refrigerant. Further, even when the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 fixed to the guide bush 20 are in contact with each other and the valve body 14 is in the lowest position, the valve body 14 and the valve seat are in contact with each other. Since a gap is formed between the body and the 46a, a predetermined amount of passing flow rate is secured.

In addition to the above configuration, the electric valve 1 of the present embodiment takes the following measures in order to ensure operability.

That is, as can be clearly seen by referring to FIGS. 3 and 4 together with FIG. 1, the movable screw portion (female screw portion) 33 formed on the inner circumference of the cylindrical portion 31 of the valve shaft holder 30 has an axis O direction (elevating direction). ) A longitudinal groove 33t formed of a concave surface extending over the entire length is formed. In this example, two longitudinal grooves 33t are provided on the opposite side of the axis O (in other words, at a position symmetrical with respect to the rotation axis O of the valve shaft holder 30).

As described above, in the electric valve 1 of the present embodiment, the female screw portion 33 of the valve shaft holder 30 constituting the screw feed mechanism 28 is provided with a longitudinal groove 33t extending over the entire length in the elevating direction (axis O direction), so that the elevating direction (Axial line O direction) Through the longitudinal groove 33t, which is a portion where the male screw portion 23 of the guide bush 20 and the female screw portion 33 of the valve shaft holder 30 do not mesh with each other (the portion where the screw surfaces are not in contact with each other) over the entire length. The fluid (refrigerant) (in the can 55) flows smoothly, and foreign matter that invades between the male threaded portion 23 and the female threaded portion 33 (between the threaded surfaces) can be positively discharged through the longitudinal groove 33t. Therefore, the risk of biting can be reduced and the deterioration of operability can be suppressed.

Further, even if a foreign substance is caught between the male threaded portion 23 of the guide bush 20 and the female threaded portion 33 of the valve shaft holder 30 (between the threaded surfaces), the foreign matter is generated by the relative rotation between the male threaded portion 23 and the female threaded portion 33. Since the foreign matter is discharged from the longitudinal groove 33t which is moved and the male screw portion 23 and the female screw portion 33 do not mesh with each other, deterioration of operability can be reliably suppressed.

Further, for example, when the valve shaft holder 30 is made of a molded product such as resin, the positions of the weld line and parting line formed at the time of molding are aligned with the position of the longitudinal groove 33t, that is, the valve is formed at the time of molding. By forming the longitudinal groove 33t along the weld line or parting line formed in the female thread portion 33 of the shaft holder 30, the weld line or parting line does not hinder the sliding, and the decrease in operability is more reliable. Can be suppressed.

For example, when a gate for injecting a molding resin is provided on the opposite side of the movable stopper body 34 in the valve shaft holder 30, as described above, the inside of the movable stopper body 34 (more specifically, the movable stopper). By providing the longitudinal groove 33t on the one end surface 34a in the circumferential direction of the body 34), the female threaded portion 33 of the valve shaft holder 30 does not have a weld line or a parting line formed at the time of molding. As described above, the decrease in operability can be suppressed more reliably.

[Second Embodiment]
FIG. 5 is a vertical sectional view showing a second embodiment of the electric valve according to the present invention.

The electric valve 2 of the second embodiment is different from the electric valve 1 of the first embodiment mainly in the shape of the longitudinal groove 33t, and other configurations are substantially the same. Therefore, the parts corresponding to the respective parts of the first embodiment are designated by a common reference numeral to omit the duplicate description, and the differences will be mainly described below.

In the electric valve 2 of the present embodiment, as can be clearly seen by referring to FIGS. 6 and 7 together with FIG. 5, the longitudinal groove 33t (in other words, a concave surface) is extended to the upper side of the female screw portion 33, and the valve is valved. It is formed over the entire length of the inner circumference (inner wall surface) of the cylindrical portion 31 of the shaft holder 30 in the axis O direction (elevating direction).

As described above, in the electric valve 2 of the present embodiment, the longitudinal groove 33t is extended over the entire length of the inner circumference (inner wall surface) of the cylindrical portion 31 of the valve shaft holder 30 in the axis O direction (elevating direction). Since it is extended to a portion that abuts (sliding) on the outer periphery of the extension portion 22 of the guide bush 20 on the upper side of the female screw portion 33, in addition to the space between the male screw portion 23 and the female screw portion 33 (between the screw surfaces). Foreign matter that enters between the cylindrical portion 31 of the valve shaft holder 30 and the extending portion 22 of the guide bush 20 (between the sliding surfaces) can be easily discharged from the longitudinal groove 33t, and the deterioration of operability is further suppressed. can do.

Further, for example, when the valve shaft holder 30 is made of a molded product such as resin, a longitudinal groove is formed along a weld line or a parting line formed on the inner circumference (inner wall surface) of the valve shaft holder 30 at the time of molding. By forming 33t, the sliding is not hindered by the weld line and the parting line, and the decrease in operability can be suppressed more reliably.

For example, when a gate for injecting a molding resin is provided on the opposite side of the movable stopper body 34 in the valve shaft holder 30, as described above, the inside of the movable stopper body 34 (more specifically, the movable stopper). By providing a longitudinal groove 33t (over the entire length in the axis O direction) on one end surface 34a in the circumferential direction of the body 34, the inner circumference (inner wall surface) of the valve shaft holder 30 (female threaded portion 33 and the guide bush) Since the weld line and the parting line formed at the time of molding do not exist in the portion (the portion that comes into contact with the outer periphery of the extending portion 22 of 20), it is possible to more reliably suppress the deterioration of the operability as described above. can.

[Third Embodiment]
FIG. 8 is a vertical sectional view showing a third embodiment of the electric valve according to the present invention.

The electric valve 3 of the third embodiment is different from the electric valve 1 of the first embodiment mainly in the formation position of the longitudinal groove 33t, and other configurations are substantially the same. Therefore, the parts corresponding to the respective parts of the first embodiment are designated by a common reference numeral to omit the duplicate description, and the differences will be mainly described below.

In the electric valve 3 of the present embodiment, instead of the longitudinal groove 33t formed in the female thread portion 33 of the valve shaft holder 30, the cylindrical portion of the guide bush 20 can be clearly seen by referring to FIGS. 9 and 10 together with FIG. A longitudinal groove 23t formed of a concave surface extending over the entire length in the axis O direction (elevating direction) is formed in the fixing screw portion (male screw portion) 23 formed on the outer circumference of the 21.

As described above, in the electric valve 3 of the present embodiment, the male screw portion 23 of the guide bush 20 constituting the screw feed mechanism 28 is provided with a longitudinal groove 23t extending over the entire length in the elevating direction (axis O direction). Similar to the embodiment, this is a portion where the male screw portion 23 of the guide bush 20 and the female screw portion 33 of the valve shaft holder 30 do not mesh with each other (the portion where the screw surfaces do not contact each other) over the entire length in the elevating direction (axis O direction). The fluid (refrigerant) (in the can 55) flows smoothly through the longitudinal groove 23t, and foreign matter that enters between the male threaded portion 23 and the female threaded portion 33 (between the threaded surfaces) is allowed to flow through the longitudinal groove 23t. Since it can be positively discharged through the pipe, the risk of biting can be reduced and the deterioration of operability can be suppressed.

Further, even if a foreign substance is caught between the male threaded portion 23 of the guide bush 20 and the female threaded portion 33 of the valve shaft holder 30 (between the threaded surfaces), the foreign matter is generated by the relative rotation between the male threaded portion 23 and the female threaded portion 33. Since the foreign matter is discharged from the longitudinal groove 23t which is moved and the male screw portion 23 and the female screw portion 33 do not mesh with each other, deterioration of operability can be reliably suppressed.

Further, for example, when the guide bush 20 is made of a molded product such as resin, the positions of the weld line and parting line formed at the time of molding are aligned with the position of the longitudinal groove 23t, that is, the guide bush at the time of molding. By forming the longitudinal groove 23t along the weld line or parting line formed in the male thread portion 23 of the guide bush 20, the weld line or parting line formed at the time of molding is formed in the male thread portion 23 of the guide bush 20. Since it does not exist, the sliding is not hindered by the weld line and the parting line, and the decrease in operability can be suppressed more reliably.

[Fourth Embodiment]
FIG. 11 is a vertical sectional view showing a fourth embodiment of the electric valve according to the present invention.

The electric valve 4 of the fourth embodiment is different from the electric valve 3 of the third embodiment mainly in the shape of the longitudinal groove 23t, and other configurations are substantially the same. Therefore, the parts corresponding to the respective parts of the third embodiment are designated by a common reference numeral to omit the duplicate description, and the differences will be mainly described below.

In the electric valve 4 of the present embodiment, as can be clearly seen by referring to FIGS. 12 and 13 together with FIG. 11, the longitudinal groove 23t is a D-cut provided in the male screw portion 23 formed on the outer circumference of the guide bush 20. In addition to being composed of surfaces, the longitudinal groove 23t (in other words, the D-cut surface) is extended to the upper side (extended portion 22 side) of the male screw portion 23, and the cylindrical portion 21 and the extending portion 22 of the guide bush 20 are extended. It is formed over the entire length of the outer circumference (outer wall surface) of the shaft line O direction (elevating direction). In this example, two longitudinal grooves 23t are provided on the opposite side of the axis O (in other words, at a position symmetrical with respect to the axis O of the guide bush 20).

As described above, in the electric valve 4 of the present embodiment, the longitudinal groove 23t extends over the entire length in the axis O direction (elevating direction) of the outer peripheral (outer wall surface) of the cylindrical portion 21 and the extending portion 22 of the guide bush 20. Since it is provided and extends to a portion that abuts (sliding) on the inner circumference of the cylindrical portion 31 of the valve shaft holder 30 on the upper side of the male screw portion 23, the second embodiment is added to the third embodiment. It is natural that the same effect can be obtained.

In the above embodiment, the male screw portion (fixing screw portion) 23 formed on the guide bush 20 (outer circumference) and the female screw portion (movable screw portion) 33 formed on the valve shaft holder 30 (inner circumference) are formed. The screw feed mechanism 28 for raising and lowering the valve body 14 with respect to the valve seat 46a is configured, but it goes without saying that the fixed screw portion side may be the female screw portion and the movable screw portion side may be the male screw portion. For example, see Patent Document 2 above).

Further, in the first and second embodiments, a longitudinal groove 33t is formed in the female screw portion (movable screw portion) 32 formed in the valve shaft holder 30 (inner circumference), and in the third embodiment, the guide bush 20 is formed. A longitudinal groove 23t is formed in the male threaded portion (fixed threaded portion) 23 formed on (outer circumference), but the female threaded portion (movable threaded portion) and the male threaded portion (moveable threaded portion) and the male threaded portion (if the vertical movement of the valve shaft 10 is not hindered). It is needless to say that longitudinal grooves may be formed on both sides of the fixing screw portion).

Further, in the above embodiment, the guide bush 20 and the valve shaft holder 30 having the male screw portion 23 and the female screw portion 33 constituting the screw feed mechanism 28 are made of resin such as PPS, but are made of metal such as SUS or brass. Of course, it is also good.

Further, in the above embodiment, when the valve body 14 is in the lowest position (normally fully closed), a gap having a predetermined size is formed between the valve body 14 and the valve seat 46a (the valve body 14 is normally fully closed). That is, the valve closing type electric valve (the valve body 14 does not sit on the valve seat 46a) has been described. It is not necessary to elaborate on what is done.

1 Electric valve (first embodiment)
2 Electric valve (second embodiment)
3 Electric valve (third embodiment)
4 Electric valve (4th embodiment)
10 Valve shaft 14 Valve body 20 Guide bush 21 Cylindrical part 22 Extension part 23 Fixed thread part (male thread part)
23t longitudinal groove (third and fourth embodiments)
24 Fixed stopper body 25 Lower stopper 28 Screw feed mechanism 29 Lower stopper mechanism 30 Valve shaft holder 31 Cylindrical part 32 Ceiling part 33 Movable screw part (female thread part)
33t longitudinal groove (first and second embodiments)
34 Movable stopper body 35 Convex part 40 Valve body 40a Valve chamber 41 First opening 41a First conduit 42 Second opening 42a Second conduit 43 Insertion hole 44 Fitting hole 45 Bottom wall 46 Valve port 46a Valve seat 47 Flange plate 48 Stopper retainer 50 Stepping motor 51 Rotor 52 Stator 55 Can 60 Compression coil spring 70 Fixing member 71 Fixing part 72 Flange part O Axis line

Claims (5)

A valve body having a valve opening with a valve seat that allows the valve body to come into contact with each other,
The valve shaft provided with the valve body and
The can fixed to the valve body and
An inner space through which the refrigerant flows is formed inside, and a rotor that rotates with the valve shaft and
A stator arranged on the outer circumference of the can and rotating the rotor with respect to the valve body,
An electric valve for a refrigeration cycle including a screw feed mechanism having a male threaded portion and a female threaded portion for raising and lowering the valve body of the valve shaft with respect to the valve seat of the valve body in response to rotation of the rotor. And
The inner space communicates with the space on the upper end side of the rotor and inside the can.
At least one of the male threaded portion and the female threaded portion is provided with a longitudinal groove extending over the entire length in the ascending / descending direction, and is configured so that the refrigerant flows through the longitudinal groove .
An electric valve characterized in that the longitudinal groove extends to a portion communicating with the inner space on the upper side of at least one of the male threaded portion or the female threaded portion in the elevating direction. The male threaded portion and the female threaded portion are provided between the guide bush into which the valve shaft is inserted and the valve shaft holder connected to the valve shaft.
The electric power according to claim 1, wherein the longitudinal groove extends over the entire length of the wall surface of the guide bush or the valve shaft holder provided with the male threaded portion or the female threaded portion in the elevating direction. valve. The electric valve according to claim 1 or 2, wherein the longitudinal groove is formed of a concave surface provided on the female thread portion. The electric valve according to any one of claims 1 to 3, wherein the longitudinal groove is formed of a concave surface or a D-cut surface provided on the male screw portion. The electric valve according to any one of claims 1 to 4, wherein the longitudinal groove is formed along a parting line or a weld line of the male threaded portion or the female threaded portion.

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