JP2020029960A - Motor-operated valve - Google Patents

Abstract

To provide a motor-operated valve capable of suppressing a deterioration in the operation property.SOLUTION: In at least either of a male screw part 23 of a guide bush 20 or a female screw part 33 of a valve shaft holder 30, as part of a screw feeding mechanism 28, vertical through grooves 23t, 33t are provided over the whole length in a lifting/lowering direction (an axis O direction) so that refrigerant flows through the vertical through grooves 23t, 33t.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric valve used as a flow control valve or the like incorporated in a refrigeration cycle of an air conditioner, a refrigerator, or the like, and in particular, controls a rotational motion of a motor by a screw feed mechanism including a male screw portion and a female screw portion. The present invention relates to a motor-operated valve that converts a linear motion into a linear motion and moves the valve body up and down.

  For example, a motor-driven type electric valve converts a rotary motion of a motor into a linear motion by a screw feed mechanism composed of a male screw portion and a female screw portion, thereby raising and lowering a valve body with respect to a valve seat, thereby causing the valve to move up and down. Opening and closing (that is, flow rate control of fluid (refrigerant) passing through the valve port) is performed.

  As this type of electric valve, for example, a valve shaft provided with a valve body at the lower end, and a guide bush having a cylindrical portion into which the valve shaft is inserted so as to be relatively movable and relatively rotatable in the axial direction. A valve body having a valve seat portion (valve seat) to which the valve body comes and goes 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. A valve shaft holder having a ceiling portion through which an insertion hole is provided, and being connected and fixed to the valve shaft, between the valve shaft and the valve shaft holder for urging the valve body in a valve closing direction; A motor having 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. Formed on the inner circumference of the valve shaft holder A screw feed mechanism for raising and lowering the valve body of the valve shaft with respect to the valve seat (valve seat) in accordance with the rotational driving of the rotor; A fixed stopper body provided on a lower stopper having a female threaded portion screwed to the fixed threaded portion of the guide bush for restricting rotation movement of the shaft holder, and a movable stopper body provided on the valve shaft holder A stopper having a predetermined size is formed between the valve body and the valve seat portion (valve seat) when the valve body is at the lowest position. Some are known (for example, see Patent Document 1).

  In the air conditioner using the valve-less type motor-operated valve as described above, even when the valve body is at the lowest position (usually in a fully closed state), a gap having a predetermined size is formed between the valve body and the valve seat. Is formed, for example, when the dehumidifying operation is performed at midnight, the operation can be performed in a state in which the amount of the refrigerant is reduced without closing the electrically operated valve, and the generation of operation noise due to ON / OFF of the electrically operated valve is suppressed. be able to. Further, the electric valve as described above has an advantage that the bite of the valve body to the valve seat can be reliably prevented as compared with the electric valve of a normal valve closing type.

  Further, as a screw feed mechanism for raising and lowering the valve body with respect to the valve seat, a mechanism using a male screw portion formed on the outer periphery of the valve shaft and a female screw portion formed on the inner periphery of the guide bush is already known. (For example, see Patent Document 2).

JP-A-2006-217451 JP-A-2006-089870

  By the way, in this type of electric valve, when foreign matter gets into the space between the male screw portion and the female screw portion (between the screw surfaces) constituting the screw feed mechanism, the sliding resistance increases and the valve shaft becomes difficult to move. Failure may occur.

  In recent years, as the cost and weight are reduced, the number of cases in which a resin material such as PPS is used for a component having a male screw portion and a female screw portion constituting a screw feed mechanism has increased. In this case, it is conceivable to manufacture a component having the above-described male screw portion or female screw portion by molding with a split mold having high molding efficiency. However, when the split mold is used, the parting line and the weld line (the locations that occur depending on the gate position differ on the sliding surface (screw surface) of the male thread and female thread), but the materials collide during molding. (A place where a short-circuit occurs due to insufficient material arrival), which may hinder sliding and cause a problem such as a decrease in operability.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a motor-operated valve that can suppress a decrease in operability.

  In order to solve the above-described problem, an electric valve according to the present invention basically includes a valve body having a valve port with a valve seat to and from which a valve body comes and goes; a valve shaft provided with the valve body; A can fixed to the valve body, an inner space in which a refrigerant flows inside is formed, and a rotor that rotates 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 accordance with the rotation of the rotor, Is communicated with the upper end side of the rotor and the space inside the can, and at least one of the male screw portion or the female screw portion is provided with a longitudinal groove extending over the entire vertical direction, so that the refrigerant flows through the longitudinal groove. Be configured It is characterized in.

  In a preferred aspect, the male screw portion and the female screw portion are provided between a guide bush into which the valve shaft is inserted and a valve shaft holder connected to the valve shaft, and the longitudinal groove includes the male screw portion or the male screw portion. The guide bush provided with a female thread portion or the valve shaft extends over the entire length of the wall surface of the valve shaft holder in the vertical direction.

  In another preferred aspect, the longitudinal groove is constituted by a concave surface provided in the female screw portion.

  In another preferred aspect, the longitudinal groove is formed by a concave surface or a D-cut surface provided in the male screw portion.

  In another preferred aspect, the longitudinal groove is formed along a parting line or a weld line of the male screw portion or the female screw portion.

  According to the present invention, at least one of the male screw portion and the female screw portion constituting the screw feed mechanism is provided with a longitudinal groove extending over the entire length in the elevating direction, so that the male screw portion and the female screw portion do not mesh with each other over the entire length in the elevating direction. The fluid (refrigerant) flows smoothly through the longitudinal groove, which is a portion (a 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 prevented. Since the discharge can be positively performed through the longitudinal grooves, the risk of biting can be reduced, and a decrease in operability can be suppressed.

  Also, even if foreign matter is caught between the male screw part and the female screw part (between the screw surfaces), the foreign matter is moved by the relative rotation of the male screw part and the female screw part, and the male screw part and the female screw part are engaged. Since the foreign matter is discharged from the non-longitudinal groove, a decrease in operability can be reliably suppressed.

  In addition, since a longitudinal groove formed by a concave surface or a D-cut surface is formed along a parting line or a weld line of the male screw portion or the female screw portion, sliding is not hindered by the grooves, thereby reducing operability. It can be suppressed more reliably.

1 is a longitudinal sectional view showing a first embodiment of a motor-operated valve according to the present invention. 2A is a perspective view, and FIG. 1B is a top view, showing the valve shaft holder shown in FIG. 1. FIG. 2 is a sectional view taken along the line U-U in FIG. 1. FIG. 5 is a sectional view showing the valve shaft holder shown in FIG. 1 and taken along the line VV of FIG. 3. The longitudinal section showing the 2nd embodiment of the electric valve concerning the present invention. FIG. 6 is a sectional view taken along line U-U of FIG. 5. FIG. 6 is a cross-sectional view showing the valve stem holder shown in FIG. 5 and taken along the line VV of FIG. 6. The longitudinal section showing the 3rd embodiment of the electric valve concerning the present invention. FIG. 9 is a sectional view taken along the line U-U in FIG. 8. FIG. 9 is a left side view showing the guide bush shown in FIG. 8. The longitudinal section showing the 4th embodiment of the electric valve concerning the present invention. FIG. 12 is a sectional view taken along line U-U of FIG. 11. FIG. 12 is a left side view showing the guide bush shown in FIG. 11.

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

  In each of the drawings, gaps formed between members, separation distances between members, and the like may be exaggerated for ease of understanding of the invention and for convenience of drawing. is there. Further, in this specification, the description indicating the position and direction such as up and down, left and right, etc. is based on the direction arrow display in FIG. 1 and the like, and does not indicate the position and direction in an actual use state.

[First Embodiment]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a motor-operated valve according to the present invention.

  The motor-operated valve 1 of the illustrated embodiment is used by being incorporated as a flow control valve or the like in a refrigerating cycle of an air conditioner, a refrigerator, or the like, and mainly includes a valve shaft 10 provided with a valve body 14 and a guide. A bush 20, a valve stem 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.

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

  The guide bush 20 is made of, for example, a resin, and is inserted in a state where the (the intermediate large-diameter portion 12 thereof) is relatively movable (slidable) in the direction of the axis O and relatively rotatable around the axis O. A cylindrical portion 21, which extends upward from an upper end portion of the cylindrical portion 21, has an inner diameter larger than that of the cylindrical portion 21, and has an upper end side of an intermediate large diameter portion 12 of the valve shaft 10 and a lower end side of an upper small diameter portion 11. And an extension portion 22 in which the extension portion 22 is inserted. On the outer periphery of the cylindrical portion 21 of the guide bush 20, one of a screw feed mechanism 28 that raises and lowers the valve element 14 of the valve shaft 10 with respect to the valve seat 46 a of the valve body 40 in accordance with the rotational driving of the rotor 51 is configured. A fixing screw portion (male screw portion) 23 is formed. The lower portion of the cylindrical portion 21 (the portion below the fixing screw portion 23) has a large diameter and serves as a fitting portion 27 for fitting into a fitting hole 44 of the valve body 40. A lower stopper 25 is screwed to the fixed screw portion 23 (on the lower side of the valve shaft holder 30), and a lower stopper for restricting rotation of the valve shaft holder 30 is provided on the outer periphery of the lower stopper 25. A fixed stopper body 24 constituting one of the mechanisms 29 is integrally protruded. In the present 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 a seated state described later).

  In this example, a stopper retainer 48 is provided on the lower stopper 25 attached to the guide bush 20 (the fixing screw portion 23 of the guide bush 20), and the lower stopper 25 is moved by the stopper retainer 48. It is non-rotatably connected to the fixing screw portion 23) (described later in detail).

  The valve stem holder 30 is made of, for example, resin (preferably, made of resin reinforced with SUS or carbon fiber having high wear resistance in consideration of contact with the fixing member 70), and the guide bush 20 is made of resin. An insertion hole 32a through which the cylindrical portion 31 to be inserted and the upper end of (the upper small-diameter portion 11 of) the valve shaft 10 are inserted (in a state of being relatively movable in the direction of the axis O and relatively rotatable around the axis O) is inserted. And a ceiling part 32 provided. A movable screw portion (female screw portion) 33 which is screwed with the fixed screw portion 23 of the guide bush 20 to form the screw feed mechanism 28 is formed at a lower portion of the inner periphery of the cylindrical portion 31 of the valve shaft holder 30. I have. Further, the upper portion of the inner periphery of the cylindrical portion 31 is brought into contact (sliding contact) with the outer periphery of the cylindrical extending portion 22 of the guide bush 20, so that the valve shaft holder 30 is connected to the outer periphery of the guide bush 20 (sliding). ), And can be raised and lowered in the direction of the axis O (vertical direction). A movable stopper body 34, which constitutes the other of the lower stopper mechanism 29, is integrally protruded from the lower end of the outer periphery of the cylindrical portion 31.

  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) has a plan view (axial line) as can be clearly understood from FIG. Two convex portions 35 having a substantially sector shape (in this case, a sector shape having a central angle of about 90 degrees) are integrally formed. More specifically, the two convex portions 35 are provided on the upper surface of the ceiling 32 around the insertion hole 32a (in other words, around the rotation axis O of the valve shaft holder 30) on the opposite side to the axis O (in other words, the valve shaft). The holder 30 protrudes upward (at a position symmetrical with respect to the rotation axis O), and in the meantime (in this example, an upper portion of the circumferential end surface 34 a of the movable stopper body 34, that is, the direction of the axis O). A portion including the same position as the one end surface 34a in the circumferential direction of the movable stopper body 34 when viewed from above has a cutout shape (substantially sector shape in plan view (here, the central angle is approximately 90-degree fan-shaped notch 36).

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

  Further, for example, when the valve stem holder 30 is made of a molded product such as a resin, the position of the weld line or parting line formed at the time of molding is matched with the position of the notch 36, that is, the weld 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 axial deviation of the valve shaft 10 can be further suppressed.

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

  In addition, by disposing 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 displacement of the valve shaft 10 can be suppressed more effectively. By disposing the protrusions 35 at a plurality of locations around the rotation axis O of the valve shaft holder 30, the contact area of the (the protrusion 35 of) the valve shaft holder 30 with respect to the fixing member 70 is further reduced. Becomes possible.

  The shape, number, position, and the like 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.

  In addition, between the step surface (step portion) 15 formed between the upper small diameter portion 11 and the middle large diameter portion 12 of the valve shaft 10 and the lower surface of the ceiling portion 32 of the valve shaft holder 30, The valve shaft 10 and the valve shaft 10 are inserted so as to be externally inserted into the upper small-diameter portion 11 of the valve shaft 10 with a disk-shaped pressing plate (washer) 61 disposed on the lower surface side of the ceiling portion 32 of the valve shaft holder 30 interposed therebetween. A cylindrical compression coil spring that urges the valve shaft holder 30 away from the valve shaft holder 30 in the vertical direction (the direction of the axis O), in other words, constantly urges the valve shaft 10 (valve element 14) downward (to close the valve). (Biasing member) 60 is contracted.

  The valve body 40 is formed 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 discharged, and a first conduit 41a is connected and fixed to a first lateral opening 41 provided on a side of the valve chamber 40a by brazing or the like. An insertion hole through which the valve shaft 10 (the intermediate large-diameter portion 12) is relatively movable (slidable) in the direction of the axis O and relatively rotatable around the axis O in the ceiling of the valve chamber 40 a. A fitting hole 44 for fitting and fixing the lower portion (fitting portion 27) of the guide bush 43 and the lower portion 43 is formed, and a second vertical opening 42 provided in the lower portion of the valve chamber 40a is formed in the second opening 42. The two conduits 42a are connected and fixed by brazing or the like. In addition, a stepped valve port 46 having a valve seat 46a with which the valve element 14 comes in contact with or separates from the bottom wall 45 between the valve chamber 40a and the second opening 42 is formed.

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

  In this embodiment, a stopper holder 48 is disposed on the upper surface (the surface on the side of the can 55) of the flange-shaped plate 47 to engage the lower stopper 25 and prevent the lower stopper 25 from rotating relative to the guide bush 20. Fixed.

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

  The outer peripheral portion of the stopper retainer 48 is brought into contact with (the upper surface of) the flange-shaped plate 47 and is fixed by welding, welding, bonding, or the like, so that the lower stopper 25 is fixed to the guide bush 20 (fixed screw portion). 23) is connected so as not to be able to rotate relatively.

  A rotor 51 is rotatably disposed inside the can 55 and outside the guide bush 20 and the valve shaft holder 30. Outside the can 55, a yoke 52a is provided to rotationally drive the rotor 51. A stator 52 including 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 a substrate 52f. The plurality of lead wires 52g are arranged in the can 55 by exciting the stator coil 52c. The existing rotor 51 rotates around the axis O.

  The rotor 51 disposed 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.

  In detail, the rotor 51 has a double-pipe configuration including an inner cylinder 51a, an outer cylinder 51b, and a connection portion 51c that connects the inner cylinder 51a and the outer cylinder 51b at a predetermined angle around the axis O. A vertical groove 51d extending in the direction of the axis O (up and down direction) (for example, at an angular interval of 120 degrees around the axis O) is formed on the inner periphery of the inner cylinder 51a.

  On the other hand, on the outer periphery (upper half portion) of the valve shaft holder 30, a tapered surface portion 30c formed of a truncated cone is provided at the upper end, as can be clearly understood from FIG. Projections 30a extending in the vertical direction (for example, at an angular interval of 120 degrees around the axis O) are protrudingly provided, and on both lower sides of the projections 30a, upward locking surfaces 30b supporting the rotor 51 are provided. Are formed.

  As described above, the vertical groove 51d of the inner cylinder 51a of the rotor 51 is engaged with the ridge 30a of the valve shaft holder 30, 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 connected. By contact, the rotor 51 is supported and fixed on the outer periphery thereof in a state of being aligned with the valve shaft holder 30, and the valve shaft holder 30 supports the rotor 51 while supporting the rotor 51 in the can 55. Rotated with.

  In this example, the rotor 51 is engaged with 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. I have.

  On the upper side of the rotor 51 and the valve shaft holder 30, relative movement between the valve shaft holder 30 and the rotor 51 in the elevating direction is prevented (in other words, the rotor 51 is pressed downward against the valve shaft holder 30 to prevent it from falling off). In order to connect the valve shaft 10 and the valve shaft holder 30 with each other, a fixing member 70 which is externally fitted and fixed to the upper end of (the upper small-diameter portion 11 of) the valve shaft 10 is arranged.

  The fixing member 70 is made of a metal member such as brass or SUS by press working, cutting work, or the like, and is externally fitted to the upper end of (the upper small-diameter portion 11 of) the valve shaft 10 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 bonding 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). And 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 inner cylinder 51a of) the rotor 51, and (the upper surface of) the convex portion 35 provided on the upper surface of the valve shaft holder 30. And the rotor 51 (the upper surface of the inner cylinder 51a thereof).

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

  In addition, the valve shaft holder 30 moves excessively upward with respect to the guide bush 20 during operation on 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 comprising a coil spring for urging the valve shaft holder 30 toward the guide bush 20 in order to prevent the fixed screw portion 23 of the guide bush 20 from being disengaged from the movable screw portion 33 of the valve shaft holder 30. 75 are provided.

  In the motor-operated valve 1, the valve element 14 is at the lowest position (origin position), for example, in order to prevent the valve element 14 from biting the valve seat 46a and to ensure controllability in a low flow rate region. Sometimes, a gap of a predetermined size is formed between the valve body 14 and the valve seat 46a.

  The process of assembling the motor-operated valve 1, particularly, the process of setting the original position (lowest position) of the valve element 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 , The rotor 51, the valve body 40, the flanged plate 47 and the like are assembled. For example, a brazed plate 47 is brazed to the valve body 40, and the guide bush 20 is press-fitted and fixed to the valve body 40, and then the lower stopper 25 is screwed to (the fixing screw portion 23 of) the guide bush 20 or the like. Assemble. At this time, the lower stopper 25 is screwed so as to be rotatable relative to the guide bush 20. At this stage, the lower stopper 25 may be disposed in contact with the stopper 27a of the guide bush 20, or may be disposed at an interval from the stopper 27a. Next, the valve body 14 provided at the lower end of the valve shaft 10 comes into contact with (seizes) 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 fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30 are in contact with each other until the fixed stopper body 24 abuts and the lower stopper 25 (the lower surface thereof) abuts 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 rotating using the screw feed mechanism 28 composed of. Then, in a state where the valve shaft holder 30 is disposed at the lowest position, the fixing member 70 is externally fitted and fixed to the upper end portion of the valve shaft 10 by press fitting, welding, welding, bonding or the like (seated state).

  Next, 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 from the seated state is lifted while rotating using the screw feed mechanism 28 to guide the guide bush. After being removed from the stopper 20, the stopper retainer 48 is placed on the valve body 40 and the flanged plate 47 while being externally attached to the lower stopper 25 so as to fall down from above, and the lower stopper 25 is moved together with the stopper retainer 48 against the guide bush 20. The valve is rotated by a predetermined rotation angle in a valve opening direction (for example, counterclockwise in plan view). Then, the stopper retainer 48 is joined and fixed to the flange-shaped plate 47 of the valve body 40 by welding, welding, bonding, or the like, and the lower stopper 25 is connected and fixed to the guide bush 20 (the fixing screw portion 23 of the guide bush 20) so as to be relatively non-rotatable. Thereafter, the assembly is assembled to the guide bush 20 again using the screw feed mechanism 28. As a result, the position of the lower stopper 25 with respect to the guide bush 20 of the fixed stopper body 24 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 abut, and the valve shaft holder 30 is moved. Even at the lowest position, a gap of a predetermined size is formed between the valve body 14 and the valve seat 46a.

  Before attaching the stopper retainer 48 to the lower stopper 25, the lower stopper 25 is rotated by a predetermined rotation angle in the valve opening direction with respect to the guide bush 20, and thereafter, the stopper retainer 48 is externally mounted on the lower stopper 25 and the valve is mounted. You may join and fix to the flange-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 (the stator coil 52c thereof), the valve shaft holder 30 and the valve shaft 10 are rotated integrally therewith. At this time, the valve shaft 10 is moved up and down along with the valve element 14 by the screw feed mechanism 28 including the fixed screw part 23 of the guide bush 20 and the movable screw part 33 of the valve shaft holder 30. The gap (lift amount, valve opening) between the valve seat 46a and the valve seat 46a is increased or decreased to adjust the 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 at the lowest position, the valve body 14 and the valve seat Since a gap is formed between the passage and the passage 46a, a predetermined flow rate is ensured.

  In addition to the above configuration, in the motor-operated valve 1 of the present embodiment, the following measures are taken to ensure operability.

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

  As described above, in the motor-operated valve 1 of the present embodiment, since the female thread portion 33 of the valve shaft holder 30 constituting the screw feed mechanism 28 is provided with the longitudinally extending groove 33t over the entire length in the vertical direction (direction of the axis O), the vertical direction is increased. (In the direction of the axis O) 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 are not engaged (a portion where the screw surfaces are not in contact with each other) over the entire length. Fluid (refrigerant) flows smoothly (in the can 55), and foreign matter that enters between the male screw part 23 and the female screw part 33 (between screw faces) can be positively discharged through the longitudinal groove 33t. Therefore, the risk of biting can be reduced, and a decrease in operability can be suppressed.

  Further, even if foreign matter is caught between the male screw part 23 of the guide bush 20 and the female screw part 33 of the valve shaft holder 30 (between the screw surfaces), the foreign matter is caused by the relative rotation between the male screw part 23 and the female screw part 33. Since the foreign matter is discharged from the longitudinal groove 33t that has been moved and the male screw part 23 and the female screw part 33 are not meshed, a decrease in operability can be reliably suppressed.

  Further, for example, when the valve shaft holder 30 is made of a molded product such as a resin, the position of the weld line or parting line formed at the time of molding is matched with the position of the longitudinal groove 33t, that is, the valve is formed at the time of molding. By forming the longitudinal grooves 33t along the weld line and the parting line formed in the female screw portion 33 of the shaft holder 30, sliding is not hindered by the weld line and the parting line, and the operability is more reliably reduced. Can be suppressed.

  For example, when a gate for injecting molding resin is provided on the valve shaft holder 30 on the side opposite to the movable stopper body 34, as described above, the inside of the movable stopper body 34 (more specifically, the movable stopper body By providing the longitudinal groove 33t on one end surface 34a in the circumferential direction of the body 34), there is no weld line or parting line formed at the time of molding in the female screw portion 33 of the valve stem holder 30. As described above, a decrease in operability can be suppressed more reliably.

[Second embodiment]
FIG. 5 is a longitudinal sectional view showing a second embodiment of the motor-operated valve according to the present invention.

  The motor-operated valve 2 of the second embodiment is different from the motor-operated valve 1 of the first embodiment mainly in the shape of the longitudinal groove 33t, and other configurations are substantially the same. Therefore, portions corresponding to the respective portions of the first embodiment are denoted by common reference numerals, and redundant description will be omitted. Hereinafter, differences will be mainly described.

  In the motor-operated valve 2 of the present embodiment, as can be clearly understood from 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 opened. It is formed over the entire length of the inner periphery (inner wall surface) of the cylindrical portion 31 of the shaft holder 30 in the direction of the axis O (elevation direction).

  As described above, in the motor-operated valve 2 of the present embodiment, the longitudinal groove 33t extends over the entire length of the inner circumference (inner wall surface) of the cylindrical portion 31 of the valve shaft holder 30 in the direction of the axis O (elevation direction), Since the portion extends above the female screw portion 33 and comes into contact (sliding contact) with the outer periphery of the extending portion 22 of the guide bush 20, in addition to the space between the male screw portion 23 and the female screw portion 33 (between the screw faces). 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 through groove 33t, and a decrease in operability is more reliably suppressed. can do.

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

  For example, when a gate for injecting molding resin is provided on the valve shaft holder 30 on the side opposite to the movable stopper body 34, as described above, the inside of the movable stopper body 34 (more specifically, the movable stopper body By providing a longitudinally extending groove 33t (over the entire length in the direction of the axis O) inside the one end surface 34a in the circumferential direction of the body 34, the inner periphery (inner wall surface) of the valve shaft holder 30 (the female screw portion 33 and the guide bush) is provided. Since no weld line or parting line is formed at the time of molding on the portion that abuts on the outer periphery of the extended portion 22 of the molding 20, it is possible to more reliably suppress the decrease in operability as described above. it can.

[Third embodiment]
FIG. 8 is a longitudinal sectional view showing a third embodiment of the motor-operated valve according to the present invention.

  The motor-operated valve 3 of the third embodiment is different from the motor-operated valve 1 of the first embodiment mainly in the formation position of the longitudinal groove 33t, and other configurations are substantially the same. Therefore, portions corresponding to the respective portions of the first embodiment are denoted by common reference numerals, and redundant description will be omitted. Hereinafter, differences will be mainly described.

  In the motor-operated valve 3 of the present embodiment, the cylindrical portion of the guide bush 20 is replaced with the longitudinal groove 33t formed in the female screw portion 33 of the valve shaft holder 30 as shown in FIGS. In a fixing screw portion (male screw portion) 23 formed on the outer periphery of the groove 21, a longitudinal groove 23 t formed of a concave surface extending over the entire length in the axis O direction (elevation direction) is formed.

  As described above, in the motor-operated 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 the longitudinally extending groove 23t over the entire length in the vertical direction (the direction of the axis O). Similar to the embodiment, the male screw part 23 of the guide bush 20 and the female screw part 33 of the valve shaft holder 30 do not mesh with each other over the entire length in the elevating direction (the direction of the axis O) (a part where the screw surfaces are not in contact with each other). Fluid (refrigerant) (in the can 55) flows smoothly through the longitudinal groove 23t, and foreign matter that enters between the male screw part 23 and the female screw part 33 (between the screw surfaces) is removed from the longitudinal groove 23t. As a result, the risk of biting can be reduced, and a decrease in operability can be suppressed.

  Further, even if foreign matter is caught between the male screw part 23 of the guide bush 20 and the female screw part 33 of the valve shaft holder 30 (between the screw surfaces), the foreign matter is caused by the relative rotation between the male screw part 23 and the female screw part 33. Since the foreign matter is discharged from the longitudinal groove 23t that has been moved and the male screw part 23 and the female screw part 33 are not meshed, a decrease in operability can be reliably suppressed.

  Further, for example, when the guide bush 20 is made of a molded product such as a resin, the position of the weld line or parting line formed at the time of molding is matched with the position of the longitudinal groove 23t, that is, the guide bush is formed at the time of molding. By forming the longitudinal groove 23t along the weld line and the parting line formed in the male screw portion 23 of the guide bush 20, a weld line and a parting line formed at the time of molding are formed in the male screw portion 23 of the guide bush 20. Since it no longer exists, sliding is not hindered by a weld line or a parting line, and a decrease in operability can be suppressed more reliably.

[Fourth embodiment]
FIG. 11 is a longitudinal sectional view showing a fourth embodiment of the motor-operated valve according to the present invention.

  The motor-operated valve 4 of the fourth embodiment is different from the motor-operated valve 3 of the third embodiment mainly in the shape of the longitudinal groove 23t, and other configurations are substantially the same. Therefore, portions corresponding to the respective portions of the third embodiment are denoted by the same reference numerals, and redundant description will be omitted. Hereinafter, differences will be mainly described.

  In the motor-operated valve 4 of the present embodiment, as can be clearly understood by referring to FIGS. 12 and 13 together with FIG. 11, the longitudinal groove 23 t is formed by a D-cut provided in the external thread portion 23 formed on the outer periphery of the guide bush 20. 23t (in other words, a D-cut surface) extends to the upper side (extending 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 formed. Is formed over the entire length of the outer periphery (outer wall surface) in the direction of the axis O (the elevating direction). In the present example, two longitudinal grooves 23t are provided on the opposite side to the axis O (in other words, at positions symmetrical with respect to the axis O of the guide bush 20).

  Thus, in the motor-operated valve 4 of the present embodiment, the longitudinal groove 23t extends over the entire length of the outer periphery (outer wall surface) of the cylindrical portion 21 and the extension portion 22 of the guide bush 20 in the direction of the axis O (elevation direction). Since it is provided and extends to a portion that comes into contact (sliding contact) with the inner periphery of the cylindrical portion 31 of the valve shaft holder 30 above the male screw portion 23, the second embodiment differs from the third embodiment in addition to the third embodiment. It goes without saying that a similar effect can be obtained.

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

  Further, in the first and second embodiments, the longitudinal thread 33t is formed in the female screw portion (movable screw portion) 32 formed in (the inner periphery of) the valve shaft holder 30. In the third embodiment, the guide bush 20 is formed. A longitudinal thread 23t is formed in a male screw portion (fixed screw portion) 23 formed on (the outer periphery of) the female screw portion (movable screw portion) and the male screw portion (movable screw portion) unless the vertical movement of the valve shaft 10 is hindered. It goes without saying that longitudinal grooves may be formed on both of the fixing screw portions.

  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 good.

  Further, in the above-described embodiment, when the valve element 14 is at the lowest position (usually in a fully closed state), a gap of a predetermined size is formed between the valve element 14 and the valve seat 46a ( That is, although the valve-less motorized valve has been described (ie, the valve element 14 is not seated on the valve seat 46a), for example, the same operation and effect as described above can be obtained also with an electric valve in which the valve element is seated on the valve seat. Needless to say, this is not described in detail.

1 electric valve (first embodiment)
2 Motorized valve (2nd embodiment)
3. Motorized valve (third embodiment)
4. Motorized valve (fourth embodiment)
10 Valve shaft 14 Valve element 20 Guide bush 21 Cylindrical part 22 Extension part 23 Fixing screw part (male screw 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 screw part)
33t longitudinal grooves (first and second embodiments)
34 movable stopper body 35 convex portion 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 holder 50 Stepping motor 51 Rotor 52 Stator 55 Can 60 Compression coil spring 70 Fixed member 71 Fixed part 72 Flange part O Axis line

Claims (5)

A valve body having a valve port with a valve seat to and from which the valve body comes and goes,
A valve shaft provided with the valve element,
A can fixed to the valve body;
An inner space through which the refrigerant flows is formed inside, and a rotor that rotates with the valve shaft,
A stator disposed on the outer periphery of the can and rotating the rotor with respect to the valve body;
An electric valve for a refrigeration cycle, comprising: 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 accordance with the rotation of the rotor. And
The inner space is communicated with a space on the upper end side of the rotor and inside the can,
A motor-operated valve, wherein at least one of the male screw portion and the female screw portion is provided with a longitudinal groove extending over the entire length in the elevating direction, so that refrigerant flows through the longitudinal groove. The male screw portion and the female screw portion are provided between a guide bush in which the valve shaft is inserted and a valve shaft holder connected to the valve shaft,
2. The electric motor according to claim 1, wherein the longitudinal groove extends over an entire length of a wall surface of the guide bush or the valve shaft holder provided with the male screw portion or the female screw portion in a vertical direction. 3. valve.   The motor-operated valve according to claim 1, wherein the longitudinal groove is configured by a concave surface provided in the female screw portion.   The motor-operated valve according to any one of claims 1 to 3, wherein the longitudinal groove is configured by a concave surface or a D-cut surface provided in the male screw portion.   The motor-operated 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 screw portion or the female screw portion.

Images