JP2008032215A - Motor operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor operated valve having less operating noises while reducing friction resistance to be produced between a valve holder and a guide stem. <P>SOLUTION: The motor operated valve comprises a valve element 61 whose upper part is inserted into the valve holder 55 so as to be axially movable and rotatable relative to a valve shaft 60, which is downwardly energized by a coil spring 64 contracted and mounted between the valve shaft 60 and itself, and which is locked to be prevented from coming off by a locking part 63 provided at the lower end of the valve holder 55, a valve body 70 having a valve chest 71 into/out of which fluid flows and a valve seat portion 72b to/from which a valve element 61 is linked or separated, and a screw feed mechanism 16 for making the valve element 61 linked to or separated from the valve seat portion 72b with the rotation of a rotor 30. The valve element 61 consists of a base body 61A having a conical valve portion 1a to be seated on the valve seat portion 72b, and a collar latch member 66 separate from the base body 61A, to be locked by the locking part 63 of the valve holder 55. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric valve driven by a stepping motor that is used as a flow control valve or the like in a refrigeration cycle such as an air conditioner or a refrigerator.

  As an electric valve used by being incorporated in an air conditioner, a refrigerator or the like, for example, as seen in Patent Document 1 below, a can, a guide stem having a cylindrical portion disposed in the can, A rotor disposed on the inner periphery of the can, a valve shaft (rotor shaft) connected and fixed to the rotor, and a cylindrical shape provided at the lower end portion of the valve shaft and inserted into the cylindrical portion of the guide stem And a coil spring that is inserted into the valve holder in an axially movable and relatively rotatable state with respect to the valve shaft and is compressed between the valve shaft and the valve shaft. The valve body is urged downward by the valve body and is prevented from coming off and locked by a locking portion provided at the lower end portion of the valve holder, the valve chamber in which fluid enters and exits, and the valve seat from which the valve body comes in contact with and separates from the valve body A valve body having a portion, and with the rotation of the rotor, Those of the stepping motor-driven is known in which a screw feed mechanism for contacting and separating with respect to the body the valve seat.

  The screw feeding mechanism usually includes a fixed screw portion (female screw portion) formed on the inner periphery of the guide stem and a movable screw portion (male screw) formed on the outer periphery of the valve shaft and screwed to the fixed screw portion. Part).

  The valve shaft, valve holder, valve body, and the like are configured as one assembly (hereinafter referred to as a valve shaft assembly), and a conventional example thereof is shown in FIG. In the illustrated valve shaft assembly 50 ′, a cylindrical valve holder 55 ′ is integrally connected to a lower end portion of a valve shaft 60 ′ whose upper portion is integrally connected to the rotor. The valve holder 55 ′ is slidably inserted in the cylindrical portion of the guide stem, and the valve body 61 ′ is moved relative to the valve shaft 60 ′ in the axial direction at the lower end portion of the valve holder 55 ′. It is inserted so as to be capable of relative rotation, and is retained and locked. The valve body 61 ′ is, in order from the bottom, a conical valve portion 61a ′ seated on the valve seat portion 72b of the valve seat member 72 having the valve port 72a, and an approximately same diameter as the outer diameter of the upper portion (bottom surface) of the conical valve portion 61a ′. Body 61b 'and a hook-like hook 61e' having a diameter larger than that of the drum 61b '. The hook-like hook 61e' is press-fitted and welded to the lower end of the valve holder 55 '. The locking collar 63 ′ fixed by, for example, is prevented from coming off. A spring receiving ball 65 ′ is disposed below the valve shaft 60 ′ in the valve holder 55 ′, and between the spring receiving ball 65 ′ and the valve body 61 ′ (the hook-shaped latching portion 61e ′). A coil spring 64 'for buffering that biases the valve body 61' downward is mounted. A fixed screw portion (female screw portion) provided on the inner periphery of the guide stem, which constitutes a screw feed mechanism for raising and lowering the valve shaft assembly 50 ′ as the rotor rotates, is provided on the outer periphery of the valve shaft 60 ′. A movable screw portion (male screw portion) 29 that is screwed together is provided.

  In the electric valve having such a configuration, when the rotor is rotated, the valve shaft is rotated integrally therewith, and at this time, the valve shaft is moved up and down with the valve body by the screw feeding mechanism, thereby the valve opening degree. (Valve opening amount) is changed to adjust the flow rate of the refrigerant.

  As described above, in this type of motor-operated valve, a required sealing pressure is obtained in a closed state where the valve body abuts on the valve seat portion, and the impact when the valve body abuts against the valve seat portion is mitigated. Therefore, a compression coil spring is interposed between the valve shaft and the valve body in the valve holder, and the valve body is always urged downward (in the valve closing direction).

Japanese Patent Laid-Open No. 10-220616

  As described above, the motor-operated valve with a built-in buffer spring in which the coil spring for biasing the valve body in the valve closing direction is provided in the valve holder has the following problems to be solved.

  In the case where the valve holder is connected and fixed to the lower end portion of the valve shaft as in the electric valve described in Patent Document 1, the valve holder slides on the guide stem (the inner periphery of the cylindrical portion) as the valve shaft rotates and moves up and down. It rotates and moves up and down while in contact, and a large frictional resistance is generated between the valve holder and the guide stem. The larger the frictional resistance, the greater the driving force required for opening and closing the valve. Therefore, a stepping motor with a large output torque, that is, a large and expensive one, must be used, and the power consumption is large. Become.

  In this case, the frictional resistance increases as the outer diameter of the valve holder increases. However, in the conventional electric valve, the outer diameter of the valve holder is relatively larger than the diameter of the valve opening (valve seat portion). It was. That is, as shown in FIG. 2B described above, the upper (bottom) outer diameter Da ′ of the conical valve portion 61a ′ of the valve body 61 ′ is the upper (bottom) of the valve seat portion 72b of the valve seat member 72. Although the diameter is substantially the same as the diameter, an upper portion (bottom surface) of the conical valve portion 61a ′ is secured to the valve body 61 ′ so as to be retained and locked to a locking collar 63 ′ provided on the valve holder 55 ′. ) It is necessary to provide a hook-shaped latching portion 61e ′ having an outer diameter Db ′ that is considerably larger than the outer diameter Da ′, and the outer diameter Dc ′ of the valve holder 55 ′ is necessarily increased. Therefore, there has been a problem that the frictional resistance between the valve holder and the guide stem is increased, and the size of the entire motor-operated valve including the stepping motor is increased.

  The lower part of the valve holder is disposed in the valve chamber where the refrigerant is introduced and led out. However, when the capacity of the valve chamber is constant, the larger the outer diameter of the valve holder, the more easily the refrigerant flow is disturbed. In particular, when the refrigerant is a mixed fluid in a liquid phase state and a gas phase state, the refrigerant passing sound tends to be high.

  The present invention has been made in view of such circumstances, and the object of the present invention is to reduce the frictional resistance generated between the valve holder and the guide stem as much as possible, and also to reduce the noise of refrigerant passing. It is an object of the present invention to provide a motor-operated valve that can be effectively suppressed and further reduced in size.

  In order to achieve the above object, an electric valve according to the present invention includes a can, a guide stem having a cylindrical portion disposed in the can, a rotor disposed on the inner periphery of the can, and the rotor. A connected and fixed valve shaft; a cylindrical valve holder provided at a lower end portion of the valve shaft and inserted in a cylindrical portion of the guide stem; and the valve holder in an axial direction with respect to the valve shaft. The upper part of the valve holder is inserted in a state where it can be relatively moved and rotated, and is urged downward by a coil spring that is compressed between the valve shaft and provided at the lower end of the valve holder. A valve body locked by a locking portion; a valve body having a valve chamber in which fluid enters and exits; and a valve seat portion to which the valve body comes into contact with and separated from the valve body; A screw feed mechanism for contacting and separating the valve seat portion.

  The valve body is hooked by a base having a conical valve portion seated on the valve seat portion and a locking portion provided in the valve holder, and is a hook-like hooking member that is a separate part from the base. It is characterized by comprising.

  The hook-shaped hooking member is preferably manufactured in a ring shape having an outer diameter smaller than the outer diameter of the upper bottom surface portion of the conical valve portion.

  The base body of the valve body preferably has a body portion having a diameter smaller than the outer diameter of the conical valve portion and the upper bottom surface portion of the conical valve portion, and the hook-shaped hooking member is provided at an upper end portion of the body portion. It is fixed by techniques such as welding, caulking, and press fitting.

  In another preferred embodiment, before the valve body is assembled to the valve holder, a locking collar as the locking portion provided in the valve holder to lock the valve body to the body portion in advance. Are inserted so as to be capable of relative movement and relative rotation, and when the valve body is assembled to the valve holder, the locking collar is fixed to the valve holder by a technique such as welding, caulking, or press fitting. Is done.

  The hook-shaped hooking member is preferably a spring receiver that receives the lower end of the coil spring.

  The hook-shaped hooking member and / or the locking portion is preferably made of a metal material or a resin material having a highly lubricated surface.

  The hook-shaped hooking member and / or the locking portion is preferably coated with a highly lubricious resin on the surface.

  The hook-shaped hooking member is preferably made of a highly-lubricated metal washer or resin washer.

  In a further preferred aspect, the hook-shaped locking member is rotatable relative to the base.

  In another preferred embodiment, the upper portion of the locking portion and the lower portion of the hook-shaped hooking member are in partial contact.

  In still another preferred embodiment, the diameter of at least one of the upper end surface of the locking collar as the locking portion and the lower end surface of the hook-shaped hooking member is 2/3 or less of the inner diameter of the valve holder, or It is made into the valve opening diameter of a valve seat part or less.

In the motor-operated valve according to the present invention, a base body having a conical valve portion and a hook-shaped hooking member locked by a locking portion (locking collar) provided in the valve holder are separate from each other. of (2 parts of) by which, when the assembly of the valve body, for example, the locking collar to the body portion continuous to the conical valve portion previously extrapolated relatively movably and relative rotation, color for the locking As shown in FIG. 2 (A), the hook-shaped hooking member is fixed to the upper end portion of the body portion located above the body by welding, caulking, press-fitting, or the like. The upper (bottom) outer diameter Da of the conical valve portion 61a of the body 61 is the same as the upper (bottom) diameter of the valve seat portion 72b of the valve seat member 72, as in the conventional example illustrated in FIG. Although it is substantially the same diameter, the outer diameter Db of the hook-shaped hooking member 66 (corresponding to the hook-shaped hooking portion 61e 'of the conventional example) is the same as the conventional example. It can be made considerably smaller than the outer diameter Db ′ of the hook-shaped latching part 61e ′ (it can be made equal to or smaller than the upper (bottom) outer diameter Da of the conical valve part 61a of the valve body 61). Therefore, the outer diameter Dc of the valve holder 55 can be made considerably smaller than the conventional one (Dc ′), and as a result, the frictional resistance generated between the valve holder and the guide stem can be greatly reduced.

  In addition, since the volume of the valve chamber can be increased without increasing the valve body, it is possible to effectively suppress noise when the refrigerant (particularly the gas-liquid mixed state) passes, and to make the size compact. be able to.

  Also, the hook-shaped hooking member that serves as a spring receiver for receiving the lower end of the buffer coil spring is made of a metal material or resin material having a highly lubricated surface, or a highly-lubricating resin is formed on the surface of the hook-shaped hooking member. Or a high-lubricity metal washer or resin washer, so that the valve shaft assembly (between the hook-shaped hooking member and the locking portion provided on the valve holder is provided with a buffer coil. For example, the frictional resistance between the spring and the hook-shaped hooking member can be reduced. Similarly, the locking portion may be made of a metal material or a resin material having a highly lubricated surface, or the surface of the hook-shaped hooking member may be coated with a highly lubricious resin. Frictional resistance in the assembly can be reduced.

  That is, since the valve body is stationary when the valve is closed (when seated on the valve seat portion), when the rotor is rotated in this state, the buffer spring (compression coil spring) is associated with the valve shaft and the valve holder. ) Is also applied, and a frictional resistance is also generated between the buffer spring and the hook-shaped latching portion serving as a spring receiver for receiving the lower end thereof. Further, when the valve holder rises while rotating from the closed state and pulls up the valve body via the locking portion and the hook-shaped hooking member provided on the valve holder, that is, when the valve is opened, the locking portion ( Since the upper end surface of the ring-shaped member is in contact with the stationary hook-shaped hooking member (the lower end surface thereof) and rotates and slides, frictional resistance is also generated between the hook-shaped hooking member and the locking portion. Accordingly, by reducing the frictional resistance, that is, the frictional resistance in the valve shaft assembly, the driving force required for the valve opening / closing operation can be reduced. Moreover, since it can prevent that a valve body rotates, abrasion of a valve seat can be prevented.

  Furthermore, by making the hook-shaped locking member rotatable relative to the base of the valve body, it is possible to further reduce the frictional resistance in the valve shaft assembly and more reliably prevent the valve body from rotating. Can do.

  In addition to the above, the upper portion of the locking portion and the lower portion of the hook-shaped hooking member are in partial contact with each other, or the upper end surface of the locking collar as the locking portion and the hook-shaped hook The locking portion and the hook-shaped hooking member can be obtained by setting the diameter of at least one of the lower end surfaces of the locking member to 2/3 or less of the inner diameter of the valve holder or the valve diameter of the valve seat portion. The frictional resistance is greatly reduced.

  As a result, the driving force required for the valve opening / closing operation can be reduced, and the entire motor-operated valve including the stepping motor can be reduced in size, power can be saved, and noise can be effectively reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a view showing an embodiment of an electric valve according to the present invention.

  The motor-operated valve 10 shown in FIG. 1 includes a valve body 70 having a valve chamber 71. The valve main body 70 includes a valve seat member 72 having a valve opening 72a having a circular cross section and a conical surface-shaped valve seat portion 72b, and a cylindrical valve chamber forming member 74 with a can receiving collar portion 74a produced by pressing. The flow rate of a fluid such as a refrigerant is adjusted by a valve body 61 that contacts and separates from the valve seat portion 72b. The valve seat member 72 has a bottom portion with a window hole of the valve chamber forming member 74 fixed thereto by press fitting, welding or the like. Further, the lower end portion of the bottomed cylindrical can 40 having a lower opening is sealed and joined to the can receiving collar 74a of the valve chamber forming member 74 by butt welding.

  A refrigerant inlet / outlet first conduit (joint) 41 is provided on one side of the valve chamber 71 of the valve body 70, and a refrigerant inlet / outlet second conduit (joint) is provided below the valve chamber 71. 42 are connected and fixed by brazing or the like.

  A rotor 30 is arranged on the inner periphery of the can 40 with a predetermined gap. Although not shown on the outer periphery of the can 40 to rotate the rotor 30, a yoke, a bobbin, and A stator composed of a stator coil or the like is disposed, and the rotor 30 and the stator constitute a stepping motor.

  On the inner peripheral side of the rotor 30, there is a valve shaft 60 integrally connected to the rotor 30 via a nut member 62, and a guide stem 80 having a cylindrical portion 81 into which the valve shaft 60 is inserted. Is distributed.

  At the lower end of the cylindrical portion 81 of the guide stem 80, a concave connection holding portion 82 used for positioning for increasing the coaxiality between the valve main body 70 and the can 40 is integrally provided.

  On the other hand, the large-diameter lower end portion of the valve shaft 60 is press-fitted and fixed to the upper end portion of the cylindrical valve holder 55. The valve holder 55 is held and fixed to the valve shaft 60 and is slidably inserted into the cylindrical portion 81 of the guide stem 80.

  The valve shaft 60, the valve holder 55, the valve body 61 and the like are configured as one assembly (hereinafter referred to as a valve shaft assembly 50), and the valve body 61 is attached to the valve shaft 60 at the lower end portion of the valve holder 55. In contrast, it is inserted in a state where it can be relatively moved and rotated in the axial direction, and is retained by a locking collar 63 described later.

  The valve body 61 is locked by a base 61A having a conical valve portion 61a seated on the valve seat portion 72b, and a locking collar 63 that is fixed to the lower end portion of the valve holder 55 by a technique such as press fitting or welding. The base 61A includes a hook-like hooking member 66 which is a separate part. The base body 61A of the valve body 60 has, in order from the bottom, a conical valve portion 61a, a body portion 61b having a diameter smaller than the outer diameter of the upper portion (bottom surface portion) of the conical valve portion 61a, and a diameter smaller than the outer diameter of the body portion 61b. The upper portion (bottom surface portion) of the conical valve portion 61a has a cylindrical portion (see FIG. 3) 61c to be a caulking portion, and is formed on the upper end surface (a terrace surface formed between the cylindrical portion 61c) of the trunk portion 61b. A hook-like hooking member 66 formed in a ring shape having an outer diameter smaller than the outer diameter of the cylindrical portion 61c is fixed by caulking the cylindrical portion 61c.

  The hook-shaped hooking member 66 is a spring receiver that receives the lower end of the coil spring 64. The hook-shaped hooking member 66 is made of a metal material or resin material having a highly lubricated surface. Alternatively, it is preferable to coat the surface of the hook-shaped hooking member 66 with a highly lubricating resin. More specifically, the hook-shaped latching member 66 is composed of a highly-lubricated metal washer using sintered metal or a resin washer obtained by adding an auxiliary auxiliary agent such as fluorine to PPS (polyphenylene sulfide). Alternatively, it is preferable to apply a coating such as electroless plating (coating) PTFE (polytetrafluoroethylene) on a metal material, or including Teflon in a hard anodizing treatment when the material is aluminum.

  The hook-like hooking member 66 is locked to the locking collar 63 secured to the lower end of the valve holder 55 by press-fitting, welding or the like. A spring receiving ball 65 is disposed below the valve shaft 60 in the valve holder 55, and between the spring receiving ball 65 and the valve body 61, a buffer for urging the valve body 61 downward. The coil spring 64 is contracted.

  Similarly to the hook-shaped hooking member 66, the locking collar 63 is made of a metal material or a resin material having a highly lubricated surface, or the surface of the locking collar 63 (upper end surface). It is preferable to apply a highly lubricious resin coating.

  In the motor-operated valve 10 of the present embodiment, as shown in FIGS. 2A and 3, the valve body 61 is preliminarily attached to the body portion 61 b before the valve body 61 is assembled to the valve holder 55. A locking collar 63 as a locking portion provided on the valve holder 55 is locked so as to be able to move and rotate relative to the valve holder 55. When the valve body 61 is assembled to the valve holder 55, the engagement collar 63 is inserted. A stop collar 63 is fixed to the valve holder 55 by a technique such as welding, caulking, or press fitting.

  In addition to the above, a screw feed mechanism 16 for bringing the valve body 61 into and out of contact with the valve seat portion 72b is provided. The screw feed mechanism 16 is fitted and fixed to the cylindrical portion 81 of the guide stem 80. A fixed screw portion (female screw portion) 28 formed on the inner periphery of the female screw member 85 and a movable screw portion formed on the outer periphery of the central portion of the valve shaft 60 of the valve shaft 60 and screwed onto the fixed screw portion 28. (Male thread portion) 29.

  Therefore, in the motor-operated valve 10 having such a configuration, when the rotor 30 is rotated, the valve shaft 60 (valve shaft assembly 50) is rotated integrally therewith. At this time, the valve shaft 60 is moved by the screw feed mechanism 16 to the valve shaft 60. The body 61 is moved up and down, whereby the valve body 61 comes into contact with and separates from the valve seat portion 72b, and the flow rate of the refrigerant is adjusted.

  Further, a fixed stopper 68 and a movable stopper (slider) 69 constituting a rotation restricting stopper mechanism are fitted on the outer periphery of the guide stem 80. As shown in FIG. 5 (A), the fixed stopper 68 is a coil spring having a valid winding number of 5.5 (5 and a half turns) and a winding direction on the right. The portion is an upper locking portion 68a bent upward from the spiral portion, and the lower end thereof is a lower locking portion 68b bent downward from the spiral portion. Further, as shown in FIG. 5 (B), the movable stopper 69 is a coil spring having an effective number of turns of 1.5 (one and a half turns) and a winding direction on the right (a spirally wound wire). The upper end portion is a side protruding contact portion 69a bent sideways from the spiral portion, and the lower end (end) of the spiral portion is an end surface contact portion 69b formed on a flat surface.

  The diameter of the wire that is the material of the movable stopper 69 is slightly larger than the diameter of the wire that is the material of the fixed stopper 68, but the pitch of the movable stopper 69 and the pitch of the fixed stopper 68 are the same. The fixed stopper 68 (the lower locking portion 68b) is fixed to the connection holding portion 82 (the bottom portion) of the guide stem 80, and the movable stopper 69 is incorporated in the spiral portion of the fixed stopper 68 as shown in FIG. It can be moved up and down while rotating along the spiral portion.

  The side protrusion contact portion 69a of the movable stopper 69 is pushed by a vertically long push plate portion 39 that protrudes from the inner periphery of the rotor 30 when the rotor 30 rotates (both forward and reverse). It has come to be. Therefore, when the rotor 30 is rotated clockwise in plan view, the movable stopper 69 descends while rotating in the same direction, and finally, the position where the most lowered position is shown by a solid line in FIG. The end surface abutting portion 69b is abutted against and locked to the lower locking portion 68b of the fixed stopper 68, whereby the rotation and lowering of the rotor 30 are forcibly stopped. When the rotor is rotated counterclockwise in plan view, the movable stopper 69 rises while rotating in the same direction, and finally, the most elevated position in FIG. The side protrusion contact portion 69a is brought into contact with and locked to the upper locking portion 68a of the fixed stopper 68, whereby the rotation and ascent of the rotor 30 are forcibly stopped.

  In the motor-operated valve 10 of the present embodiment configured as described above, the valve body 61 includes a base 61A having a conical valve portion 61a, a body portion 61b, and a cylindrical portion (caulking portion) 61c, and a valve holder 55. The hook-shaped hooking member 66 locked by the provided locking portion (locking collar 63) is separated (two parts), and the assembly of the valve body 61 is shown in FIG. As shown in the figure, the locking collar 63 is extrapolated to the barrel portion 61b connected to the conical valve portion 61a so as to be capable of relative movement and rotation, and the upper end surface of the barrel portion 61b located above the locking collar 63. Since the hook-like hooking member 66 is caulked and fixed to the terrace surface, as shown in FIG. 2A, the upper (bottom) outer diameter Da of the conical valve portion 61a of the valve body 61. Is similar to that of the conventional example illustrated in FIG. Although the diameter is substantially the same as the upper (bottom) diameter of the valve seat portion 72b of the material 72, the outer diameter Db of the hook-shaped hooking member 66 (corresponding to the hook-shaped hooking portion 61e 'of the conventional example) is changed to the conventional example ( The outer diameter Db ′ of the hook-shaped hooking portion 61e ′) can be considerably smaller (can be equal to or smaller than the outer diameter Da of the upper portion (bottom surface) of the conical valve portion 61a of the valve body 61). Therefore, the outer diameter Dc of the valve holder 55 can also be made considerably smaller than the conventional one (Dc ′), and as a result, the frictional resistance generated between the valve holder 55 and the guide stem 80 (the cylindrical portion 81 thereof). Can be greatly reduced.

  Further, since the volume of the valve chamber 71 can be increased without increasing the valve body 70, the passage sound of the refrigerant (particularly the gas-liquid mixed state) can be reduced and the size can be reduced. .

  In addition, as described above, the hook-shaped latching member 66 that serves as a spring receiver for receiving the lower end of the buffer coil spring 64 is constituted by a highly-lubricated metal washer, etc. The frictional resistance in the three-dimensional body 50 (between the hook-shaped hooking member 66 and the locking collar 63, between the coil spring 64 and the hook-shaped hooking member 66, etc.) can be reduced, and the valve body 61 is provided. It is possible to prevent rotation while seated on the valve seat 72b.

  In addition, if high lubricity is given to the entire valve body 61 ′ of the conventional example shown in FIG. 2B, the frictional resistance can be reduced, but there is a risk of causing valve leakage and the like. It is necessary to mask and coat other than the hook-shaped hooking portion 61e ', which takes time and leads to an increase in cost.

  Similarly to the hook-shaped hooking member 66, the locking collar 63 is made of a metal material or a resin material having a highly lubricated surface, or the surface of the locking collar 63 (upper end surface). The frictional resistance in the valve shaft assembly 50 can be further reduced by applying a high-lubricating resin coating to the valve shaft assembly 50.

Further, as shown in FIG. 4, a pressing ring 67 is disposed on the upper side of the hook-shaped hooking member 66, and the pressing ring 67 is fixed by caulking (caulking portion 61c), whereby the hook-shaped locking member 66 is fixed to the valve body. By making it relatively rotatable with respect to one base 61A (with a thrust bearing structure),
The frictional resistance can be further reduced and the rotation of the valve body 61 can be prevented more reliably.

  In addition to the above, as shown in FIG. 7 (B), the upper portion of the locking collar 63 is properly aligned so that the upper portion of the locking collar 63 and the lower portion of the hook-shaped hooking member 66 are in partial contact. By using a vertical truncated cone shape (the diameter of the upper end surface of the locking collar 63 is 2/3 or less of the inner diameter of the valve holder 55 or less than the diameter of the valve port 72a), or as shown in FIG. As shown in the figure, the lower portion of the hook-shaped hooking member 66 is formed in an inverted truncated cone shape (the diameter of the lower end surface of the hook-shaped hooking member 66 is 2/3 or less of the inner diameter of the valve holder 55 or the diameter of the valve port 72a. Therefore, the contact diameter is reduced and the frictional resistance can be further reduced.

  Instead of caulking and fixing the hook-shaped hooking member 66 to the valve body 61 as shown in FIG. 7 (A), the upper portion 61d of the valve body 61 is attached as shown in FIG. 7 (C). While extending upward, the hook-shaped hooking member 66 may be a cylindrical shape with a hook-shaped portion (lower part is an inverted truncated cone shape) at the lower end, and may be press-fitted and fixed to the upper portion 61f of the valve body 61. .

  As a result, the driving force required for the valve opening / closing operation can be reduced, and the entire motor-operated valve including the stepping motor can be reduced in size and power can be effectively reduced.

The longitudinal cross-sectional view of the principal part except the stator of one Embodiment of the electrically operated valve which concerns on this invention. (A) is the valve-shaft assembly part of the motor-driven valve of embodiment shown by FIG. 1, (B) is the valve-shaft assembly part of the motor-driven valve of a prior art example. The exploded view before the assembly of the valve body of the electrically operated valve of embodiment shown by FIG. The fragmentary sectional view which shows the modification of the valve body part of the electrically operated valve of embodiment shown by FIG. The figure which shows the fixed stopper (A) and movable stopper (B) which comprise the stopper mechanism for rotation control of the electrically operated valve of embodiment shown by FIG. The figure which is provided for operation | movement description of the stopper mechanism for rotation control of the electrically operated valve of embodiment shown by FIG. The figure which shows the example of improvement of the collar for latching and the hook-shaped latching member of the electrically operated valve of embodiment shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric valve 16 Screw feed mechanism 30 Rotor 28 Fixed screw part 29 Movable screw part 40 Can 50 Valve shaft assembly 55 Valve holder 60 Valve shaft 61 Valve body 61A Base body 61a Conical valve part 61b Body part 61c Cylindrical part (Caulking part)
63 Locking collar 64 Buffer coil spring 66 Hook-shaped hooking member 70 Valve body 71 Valve chamber 72 Valve seat 72a Valve port 72b Valve seat portion 74 Valve chamber forming member 80 Guide stem 81 Cylindrical portion

Claims (11)

A can, a guide stem having a cylindrical portion disposed in the can, a rotor disposed on the inner periphery of the can, a valve shaft connected and fixed to the rotor, and a lower end portion of the valve shaft A cylindrical valve holder inserted into the cylindrical portion of the guide stem, and an upper portion of the valve holder is inserted into the valve holder so as to be capable of relative movement and rotation in the axial direction with respect to the valve shaft, and And a valve body that is biased downward by a coil spring that is compressed between the valve shaft and is retained by a retaining portion provided at a lower end portion of the valve holder, and fluid enters and exits. A valve body having a valve chamber to be squeezed and a valve seat part to which the valve body comes into contact with and separated from the valve body; and a screw feed mechanism for making the valve body come into contact with and separate from the valve seat part as the rotor rotates. A motorized valve,
The valve body includes a base body having a conical valve portion that is seated on the valve seat portion, and a hook-like hooking member that is locked by a locking portion provided in the valve holder and is a separate part from the base body. A motor-operated valve characterized by comprising.   The motor-operated valve according to claim 1, wherein the hook-shaped hooking member is formed in a ring shape having an outer diameter smaller than an outer diameter of the upper bottom surface portion of the conical valve portion.   The base body of the valve body has a body portion having a diameter smaller than the outer diameter of the conical valve portion and the upper bottom surface portion of the conical valve portion, and the hook-shaped hooking member is welded and caulked to the upper end portion of the body portion. The motor-operated valve according to claim 1, wherein the motor-operated valve is fixed by a method such as press fitting.   Prior to assembly of the valve body to the valve holder, a locking collar as the locking portion provided on the valve holder to lock the valve body on the body portion in advance is relatively moved and rotated. The locking collar is fixed by a technique such as welding, caulking, press-fitting, etc. to the valve holder when the valve body is assembled to the valve holder. The motor-operated valve according to claim 3.   The motor-operated valve according to any one of claims 1 to 4, wherein the hook-shaped hooking member is a spring receiver that receives a lower end of the coil spring.   The motor-operated valve according to claim 5, wherein the hook-shaped hooking member and / or the locking portion is made of a metal material or a resin material having a highly lubricated surface.   The motor-operated valve according to claim 5, wherein a surface of the hook-shaped hooking member and / or the locking portion is coated with a highly-lubricating resin.   The motor-operated valve according to claim 5, wherein the hook-shaped hooking member is made of a highly-lubricated metal washer or a resin washer.   The motor-operated valve according to any one of claims 5 to 8, wherein the hook-shaped locking member is rotatable relative to the base body.   The motor-operated valve according to any one of claims 1 to 9, wherein an upper portion of the locking portion and a lower portion of the hook-shaped hooking member are in partial contact with each other.   The diameter of at least one of the upper end surface of the locking collar as the locking portion and the lower end surface of the hook-shaped latching member is 2/3 or less of the inner diameter of the valve holder or the valve diameter of the valve seat portion. The motor-operated valve according to claim 10, wherein:

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