JP2019078386A - Motor-operated valve - Google Patents

Abstract

To provide a motor-operated valve that can improve operability by suppressing contact resistance (slide resistance) to a lower level even when an axial deviation occurs in a valve stem, for instance.SOLUTION: In a motor-operated valve, a valve stem 10 has a part (lower-large-diameter part 12) on a lower side (valve element 14 side) than a terrace surface 13 to which a compression coil spring 60 is disposed as an energization member, which is inserted into a guide bushing 20 so as to be capable of sliding, and is guided in a direction of an axis line O only on the lower side (valve element 14 side) of the compression coil spring 60.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor-operated valve used as a flow control valve or the like in a refrigeration cycle of an air conditioner, a refrigerator or the like.

  As the motor-operated valve of this type, for example, a valve body having a valve chamber and a valve port formed in the valve chamber, a valve body for opening and closing the valve port, a can projecting from the valve body, and an outer side of the can , A stator coil disposed inside the can, a rotor that is rotated by energization excitation of the stator coil, a screw pipe (guide bush) fixed to the valve body, and a rotor that is rotatable together with the rotor A valve shaft holder that causes the valve body to open and close the valve port via the valve shaft by a screw feeding action with the screw pipe, and is interposed between the valve shaft holder and the valve shaft, the valve A valve-closing spring which biases the valve body in a closing direction of the valve port via a shaft, and the valve shaft holder in a direction in which the valve body opens and closes the valve port in cooperation with the valve-closing spring Stopper (fixed to prevent relative movement with the rotor Material in which the movement (up and down movement) of the valve stem in the opening and closing direction of the valve stem is guided by the screw pipe (guide bush) and the valve stem holder (for example, Patent Document 1) reference).

  In this type of conventional motor-operated valve, in order to close the valve opening reliably by the valve body, usually, after the valve element is seated on a valve seat provided at the valve opening and the valve opening is closed, the rotor and The valve stem holder is rotated in the valve closing direction by a predetermined amount (rotation amount) and lowered, thereby compressing the valve spring interposed between the valve stem holder and the valve stem, and thereby the valve body It is adapted to be pressed against the valve seat.

  In detail, in closing the motor-operated valve, the stator coil is energized by energizing the stator coil in one direction and excited. This causes the rotor to rotate, which causes the valve shaft holder to rotate relative to the guide bush (screw tube). Here, for example, the valve shaft holder is lowered by the screw feed mechanism of (the fixed screw portion of the guide bush) and (the movable screw portion of the valve shaft holder), and the valve shaft is lowered accordingly. Close the valve port. At this time, fixing the movable stopper (upper stopper portion) of the valve shaft holder and the guide bush constituting the stopper mechanism for limiting the rotation of the valve shaft holder (and the rotor) in the valve closing direction and the downward movement of the valve shaft holder. It is positioned away from the stopper body (lower stopper body).

  When the stator coil is further energized in one direction from the above state to excite it, the valve shaft holder is further lowered by the screw feed mechanism while the valve body remains closed (that is, the valve shaft remains stationary). . When the valve stem holder descends by a predetermined amount, the movable stopper of the valve stem holder abuts against the fixed stopper of the guide bush, and the stopper mechanism restricts further lowering of the valve stem holder. At this time, since the valve-closing spring interposed between the valve shaft holder and the valve shaft is compressed, the valve body is strongly pressed against the valve seat, and the valve-closing property is ensured (fully closed state) . Further, at this time, the valve shaft holder is separated from the fixing member (stopper) fixed to the valve shaft by a predetermined gap in the elevating direction.

  On the other hand, when the motor-operated valve is opened from the fully closed state, the stator coil is energized in the other direction to excite it. As a result, the rotor is relatively rotated in the direction opposite to the above with respect to the guide bush fixed to the valve body, and the valve shaft holder is raised by the screw feed mechanism. Here, since the valve shaft holder is positioned apart from the fixed member fixed to the valve shaft by a predetermined gap, the valve body is closed at the valve opening (while the valve shaft holder is raised by the predetermined gap) The valve stem holder ascends as it is closed (with the valve stem stationary).

  From the above state, the stator coil is further energized in the other direction to excite, and when the valve shaft holder rises by the predetermined gap, the disc-like portion of the fixing member (the upper surface of the valve shaft holder) is fixed to the valve shaft The lower end of the valve stem is moved upward to open the valve port.

  In this manner, the rotor is rotated by energization excitation to the stator coil, and the valve shaft holder is rotated integrally therewith, and the valve shaft is moved up and down with the valve body, whereby the valve body and the valve are moved. The clearance (lift amount) between the seat and the seat is increased or decreased to adjust the flow rate of the fluid such as the refrigerant.

JP, 2011-208716, A

  By the way, in the conventional motor-operated valve as described above, the valve shaft is inserted in the center of the valve shaft holder so as to be vertically movable, and the movement (vertical movement) of the valve shaft holder and the valve shaft in the valve opening and closing direction It is guided by a bush. Therefore, when an axial deviation (inclination with respect to the axis or eccentricity in a direction perpendicular to the axis) or the like occurs due to dimensional dispersion or the like in consideration of operability (slidability), There is a possibility that the contact resistance (sliding resistance) with the valve shaft holder becomes large, and the operability deteriorates. Further, in the conventional motor-operated valve as described above, the valve-closing spring is interposed between the portion guided in sliding contact with the guide bush in the valve shaft and the portion guided in sliding contact with the valve shaft holder. There is a concern that the contact resistance (sliding resistance) may be increased by deformation of the valve-closing spring in accordance with the axial displacement of the valve stem.

  Moreover, in recent years, the pressure in the circuit of the refrigeration cycle tends to increase due to the use of the refrigerant which has been changed in consideration of environmental problems and the like. In order to cope with the pressure increase, it is necessary to make the spring stronger than in the conventional case to improve the valve closing property of the motor-operated valve, but when the strong spring is deformed, the valve shaft is subjected to a strong force in the perpendicular direction. Since it may press, there existed concern that the said contact resistance (sliding resistance) might become large further.

  The present invention has been made in view of the above problems, and the object of the present invention is to suppress the contact resistance (sliding resistance) to a low value even when, for example, an axial misalignment of the valve shaft or the like occurs. An object of the present invention is to provide an electrically operated valve capable of improving operability.

  In order to solve the problems described above, the motor-operated valve according to the present invention basically comprises a valve shaft provided with a valve body and a guide in which the valve shaft is inserted so as to be relatively movable and relatively rotatable in the axial direction. A valve body having a bush and a valve seat with a valve seat to which the valve body contacts and separates, the guide bush is attached and fixed, a valve shaft holder mounted on the valve shaft, and a terrace formed on the valve shaft A biasing member interposed between the surface and the valve shaft holder, for biasing the valve body in the valve closing direction, and fixed to the valve shaft so as to connect the valve shaft holder to the valve shaft, A fixing member to which the valve shaft holder is brought into contact by the urging force of the urging member; a motor having a rotor and a stator for rotating the valve shaft holder with respect to the guide bush; and rotational driving of the rotor In response to the valve body of the valve stem A screw feed mechanism provided between the guide bush and the valve shaft holder for raising and lowering the valve seat of the body, the valve shaft having a portion below the terrace surface It is characterized in that the guide bush is slidably inserted into the guide bush and axially guided only on the lower side of the biasing member.

  In a preferred aspect, a portion of the valve shaft above the terraced surface is inserted into the insertion hole provided in the valve shaft holder with a predetermined gap.

  In a further preferred aspect, the biasing member is interposed between the terrace surface and the valve shaft holder so as to be extrapolated to a portion above the terrace surface of the valve shaft, and the hole of the insertion hole The diameter is larger than the inner diameter of the biasing member.

  In a further preferred aspect, the outer diameter of the biasing member is larger than the diameter of the insertion hole and the diameter of the portion of the valve shaft below the terrace surface.

  In another preferable aspect, a portion of the valve shaft to which the fixing member is fixed is larger in diameter than a portion of the valve shaft inserted in the insertion hole and smaller in diameter than the diameter of the insertion hole.

  According to the present invention, the valve shaft is inserted into the guide bush so as to be slidable below the terrace surface on which the biasing member is disposed (valve body side), and the lower side of the biasing member (valve body) Since the valve shaft is guided in the axial direction only and does not contact with the (inner wall of the insertion hole of the valve shaft holder), for example, the conventional electric motor in which the valve shaft is guided by both the guide bush and the valve shaft holder above and below the biasing member. As compared with the valve, the contact resistance (sliding resistance) can be suppressed low, and the operability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the fully closed state of one Embodiment of the motor operated valve which concerns on this invention. The longitudinal cross-sectional view which shows the state by which the valve-shaft holder and the fixing member were contact | abutted of one Embodiment of the motor operated valve which concerns on this invention. The valve-shaft holder shown by FIG. 1 is shown, (A) is a perspective view, (B) is a top view.

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

  In each of the drawings, the gaps formed between the members, the separation distance between the members, etc. may be drawn in an exaggerated manner in order to facilitate understanding of the invention and for convenience of drawing. is there. Further, in the present specification, the description representing the position and direction such as upper and lower and right and left is based on the direction arrow display of FIG. 1 and FIG. 2 and does not indicate the position and direction in an actual use state.

  1 and 2 are longitudinal sectional views showing an embodiment of the motor-operated valve according to the present invention, and FIG. 1 shows a fully closed state (a state where the rotor and the valve shaft holder are at the lowest position); FIG. 7 is a view showing a state in which the valve shaft holder and the fixing member are in contact with each other.

  The motor-operated valve 1 of the illustrated embodiment is used by being incorporated as a flow control valve or the like in a refrigeration cycle such as an air conditioner or a refrigerator, mainly using a valve shaft 10 provided with a valve body 14 and a guide A stepping motor 50 comprising a bush 20, a valve shaft holder 30, a valve body 40, a can 55, 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 stem 10 has an upper small diameter portion 11 and a lower large diameter portion 12 from the upper side, and controls the flow rate of the fluid (refrigerant) flowing through the valve port 46 at the lower end of the lower large diameter portion 12. A stepped (here three-step) inverted conical valve body 14 is integrally formed. Further, the upper end portion of (the upper small diameter portion 11 of) the valve stem 10 has a large diameter, and the small diameter upper portion 71 a of the fixing portion 71 of the fixing member 70 described later is fixed to the large diameter connecting portion 15. The outer diameter of the large diameter connecting portion 15 is larger than the upper small diameter portion 11 and smaller than the lower large diameter portion 12, and the diameter of the insertion hole 32a of (the ceiling 32 of the valve shaft holder 30 described later). The diameter is slightly smaller than the hole diameter (diameter).

  The guide bush 20 is inserted in a cylindrical portion 21 in which the valve shaft 10 (the lower large diameter portion 12 thereof) is relatively movable (slidable) in the direction of the axis O and relatively rotatable around the axis O; Extending upward from the upper end of the cylindrical portion 21, the inner diameter is larger than that of the cylindrical portion 21, and the upper end side of the lower large diameter portion 12 of the valve shaft 10 and the lower end side of the upper small diameter portion 11 are inserted. And a setting unit 22. One end of a screw feed mechanism 28 configured to raise and lower the valve body 14 of the valve shaft 10 with respect to the valve seat 46 a of the valve main body 40 according to the rotational drive of the rotor 51 The 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 serves as a fitting portion 27 to the fitting hole 44 of the valve main body 40. The lower stopper 25 is screwed and fixed to the fixed screw portion 23 (in the lower side than the valve shaft holder 30 in the above), and the rotation downward movement restriction of the valve shaft holder 30 is restricted on the outer periphery of the lower stopper 25. A fixed stopper body 24 constituting one of the lower stopper mechanisms 29 to be carried out is integrally provided in a protruding manner.

  The valve shaft holder 30 is, for example, made of resin (preferably made of resin reinforced with SUS, carbon fiber or the like having high abrasion resistance in consideration of contact with the fixing member 70), and the guide bush 20 is The upper end of the cylindrical portion 31 to be inserted and the upper end portion of (the upper small diameter portion 11 of) the valve shaft 10 is inserted (in a relatively movable state in the direction of the axis O and relatively rotatable around the axis O) And a ceiling 32 provided. In this example, the hole diameter of the insertion hole 32a is larger than the upper end of (the upper small diameter portion 11) of the valve shaft 10, and (the upper small diameter portion 11) of the valve shaft 10 is predetermined in the insertion hole 32a. It is inserted (freely fitted) with a gap. A movable screw portion (female screw portion) 33 which forms the screw feed mechanism 28 by being screwed with the fixed screw portion 23 of the guide bush 20 is formed at the lower inner periphery of the cylindrical portion 31 of the valve shaft holder 30. At the same time, the inner peripheral upper portion of the cylindrical portion 31 is in contact (sliding contact) with the outer periphery of the cylindrical extending portion 22 of the guide bush 20. At the lower end of the outer periphery of the cylindrical portion 31, a movable stopper body 34 constituting the other of the lower stopper mechanism 29 is integrally provided in a protruding manner.

  Further, 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, as can be seen with reference to FIGS. The two convex portions 35 having a substantially fan shape (here, a fan shape having a central angle of about 90 degrees) (in the direction of the axis O) are integrally formed. Specifically, the two projections 35 are on the opposite side to the axis O (in other words, the valve axis) around the insertion hole 32a in the upper surface of the ceiling 32 (in other words, around the rotation axis O of the valve shaft holder 30). While projecting upward at a position symmetrical with respect to the rotation axis O of the holder 30, and in the meantime (in this example, the upper portion of one end face 34a in the circumferential direction of the movable stopper body 34, ie, the axis O direction) When viewed in a section including the same position as one end face 34a in the circumferential direction of the movable stopper 34) (a substantially fan shape (in this case, the central angle is about 90 degrees fan-shaped) notch 36).

  The contact area (rotational sliding resistance) when the valve shaft holder 30 abuts on the fixing member 70 decreases, for example, because the contact area of the valve shaft holder 30 with the fixing member 70 is reduced by the convex portion 35. The slidability between the valve shaft holder 30 and the fixing member 70 at the time of valve opening becomes good, and operation defects such as rapid deceleration, stop, and reversal of the rotor 51 are suppressed, and axial deviation of the valve shaft 10 is suppressed. Can.

  Also, for example, when the valve shaft holder 30 is made of a molded product such as 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, weld at the time of molding By providing the notches 36 at locations where lines or parting lines are formed, the contact resistance (rotational sliding resistance) can be further reduced, and the flatness of the sliding surface of the valve shaft holder 30 becomes high. The axial misalignment of the valve stem 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, the upper side of the movable stopper body 34 (more specifically, the movable stopper By forming the notch 36 in the upper part of one end face 34a in the circumferential direction of the body 34, a 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 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 axial displacement of the valve shaft 10 can be further suppressed.

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

  Of course, the shape, number, position, etc. of the projections 35 provided on the upper surface of the ceiling 32 of the valve shaft holder 30 are not limited to the illustrated example, and the projections 35 may be omitted. Good.

  Further, between the terraced surface (stepped portion) 13 formed between the upper small diameter portion 11 and the lower 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 above-mentioned valve shaft 10 and the above are inserted so as to be externally inserted into the upper small diameter portion 11 of the valve shaft 10 with the disc-like presser plate (washer) 61 disposed on the lower surface side of the ceiling portion 32 of the valve shaft holder 30 A cylindrical compression coil spring which urges the valve shaft holder 30 away from the valve shaft holder 30 in the raising and lowering direction (axial line O direction), in other words, always urges the valve shaft 10 (valve body 14) downward (valve closing direction). The (biasing member) 60 is contracted. Here, the inner diameter of the compression coil spring 60 is smaller than the diameter of the insertion hole 32a into which the upper small diameter portion 11 (portion above the terraced surface 13) of the valve shaft 10 is inserted (in other words, the hole of the insertion hole 32a The diameter is larger than the inner diameter of the compression coil spring 60, and the outer diameter of the compression coil spring 60 is lower than the diameter of the insertion hole 32a and the lower large diameter portion 12 of the valve shaft 10 It is made larger than the shaft diameter (diameter) of the part of the valve body 14).

  The valve body 40 is made of, for example, a metal cylinder such as brass or SUS. The valve main body 40 has a valve chamber 40a into which a fluid is introduced and discharged, and the first conduit 41a is connected and fixed to the first transverse opening 41 provided on the side of the valve chamber 40a by brazing or the like. (The lower large-diameter portion 12 of the valve shaft 10 is relatively movable (slidable) in the direction of the axis O and inserted into the ceiling of the valve chamber 40a in a relatively rotatable state about the axis O). 43 and a lower part (fitting part 27) of the guide bush 20 are formed to form a fitting hole 44 to be fitted and fixed, and the second vertical opening 42 provided at the lower part of the valve chamber 40a 2 The conduits 42a are connected and fixed by brazing or the like. Further, on the bottom wall 45 between the valve chamber 40a and the second opening 42, a stepped valve port 46 having a valve seat 46a with which the valve body 14 contacts and separates is formed.

  An annular cage plate 47 is fixed by caulking or brazing to the upper end portion of the valve main body 40 by brazing or the like, and a cylindrical can 57 with a ceiling is provided at a step portion provided on the outer periphery of the cage plate 47. The lower end of the seal is hermetically joined by butt welding or the like.

  A rotor 51 is rotatably disposed inside the can 55 and outside the guide bush 20 and the valve shaft holder 30, and a yoke 52a is provided outside the can 55 so as to rotationally drive the rotor 51. A stator 52 including a bobbin 52b, a stator coil 52c, and a resin mold cover 52d is disposed. A plurality of lead terminals 52e are connected to the stator coil 52c, and a plurality of lead wires 52g are connected to the lead terminals 52e via the substrate 52f, and distributed in the can 55 by energization excitation to the stator coil 52c. The existing rotor 51 is designed to rotate around the axis O.

  The rotor 51 disposed in the can 55 is engaged with and supported by the valve shaft holder 30, and the valve shaft holder 30 is configured to rotate together with the rotor 51 (integrally).

  In detail, the rotor 51 has a double pipe configuration including an inner cylinder 51a, an outer cylinder 51b, and a connecting portion 51c connecting the inner cylinder 51a and the outer cylinder 51b at a predetermined angular position around the axis O, On the inner periphery of the inner cylinder 51a, there is formed a longitudinal groove 51d extending along the axis O direction (vertical direction) (for example, at an angular interval of 120 degrees around the axis O).

  On the other hand, on the outer periphery (upper half of the valve shaft holder 30), as is well understood with reference to FIG. 3, a tapered surface portion 30c consisting of a frusto-conical surface is provided at the upper end thereof. In the upper and lower direction (for example, at an angular interval of 120 degrees around the axis O), projecting ridges 30a are provided, and on the lower sides of the ridges 30a, an upward engaging surface 30b for supporting the rotor 51. Is formed.

  Thus, the vertical groove 51d of the inner cylinder 51a of the rotor 51 engages with the projection 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 By abutting, the rotor 51 is supported and fixed on the outer periphery 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 the rotor 51 is supported. Co-rotated with

  In the present embodiment, 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. There is.

  The relative movement between the valve shaft holder 30 and the rotor 51 in the vertical direction is prevented above the rotor 51 and the valve shaft holder 30 (in other words, the rotor 51 is pressed downward against the valve shaft holder 30 to prevent removal) In order to connect the valve stem 10 and the valve stem holder 30 with each other, a fixing member 70 externally fitted and fixed to the upper end portion of (the upper small diameter portion 11 of) the valve stem 10 is disposed.

  The fixing member 70 is manufactured, for example, by pressing, cutting, etc. from a metal member such as brass or SUS, and is externally fitted to the upper end (large diameter connecting portion 15) of (the upper small diameter portion 11 of the valve shaft 10). And the lower end portion of (the large diameter lower portion 71b of the large diameter lower portion 71b) of the stepped cylindrical fixing portion 71 including the small diameter upper portion 71a and the large diameter lower portion 71b joined and fixed by press fitting, welding, welding, adhesion and the like. And a disk-like flange portion 72 extending outward to the vicinity of the inner cylinder 51 a of the rotor 51.

  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 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 of the rotor 51).

  As described above, the rotor 51 is held between the valve shaft holder 30 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 It is locked.

  Further, the valve shaft holder 30 is moved to the upper side relative to the guide bush 20 too much during operation of the fixing member 70 (the large diameter lower portion 71b of the fixing portion 71 in the fixing member 70 fixed to the upper end portion of the valve shaft 10). A return spring comprising a coil spring biasing the valve shaft holder 30 toward the guide bush 20 in order to prevent disengagement of the fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30; There are 75 exteriors.

  In the motor-operated valve 1 having such a configuration, when the rotor 51 is rotated by energization and energization of 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 together with the valve body 14 by the screw feed mechanism 28 composed of the fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30. The clearance (lift amount, valve opening) between the valve seat 46a and the valve seat 46a is increased or decreased to adjust the flow rate of the fluid such as the refrigerant.

  Further, in the motor-operated valve 1 of the present embodiment, when the valve shaft 10 is lowered and the valve body 14 is seated on the valve seat 46 a, the fixed stopper fixed to the movable stopper body 34 of the valve shaft holder 30 and the guide bush 20 The rotor 24 is separated from the body 24, and then the rotor 51 is further rotated by the further energization excitation to the stator 52 (the stator coil 52c), and the valve shaft holder 30 is rotated and lowered integrally therewith. Then, the movable stopper 34 of the valve shaft holder 30 abuts on the fixed stopper 24 fixed to the guide bush 20, that is, the lower stopper mechanism 29 stops the rotation and lowering of the valve shaft holder 30, thereby The compression coil spring 60 interposed between the valve shaft holder 30 and the valve shaft 10 is compressed, and the valve body 14 is strongly pressed against the valve seat 46a. It has become to so that.

  In detail, when closing the motor-operated valve 1, the stator coil 52c is energized by energizing the stator coil 52c in one direction. As a result, the rotor 51 is rotated, and the valve shaft holder 30 is rotated relative to the guide bush 20 accordingly. Here, the valve shaft holder 30 is provided with the extension portion 22 (of the guide bush 20 by the screw feeding mechanism 28 including the guide bush 20 (the fixed screw portion 23 thereof) and the valve shaft holder 30 (the movable screw portion 33). While being guided by the outer circumference), the valve shaft 10 is lowered (while being guided by (the inner circumference of the cylindrical portion 21 of the guide bush 20)), and the valve body 14 is seated on the valve seat 46a. The valve port 46 is closed. At this time, the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the guide bush 20 constituting the lower stopper mechanism 29 are positioned apart from each other (the state shown in FIG. 2).

  When the stator coil 52c is further energized in one direction from the above state to excite, the valve body 14 keeps the valve port 46 closed (that is, the valve shaft 10 remains stationary), and the screw feed mechanism 28 The holder 30 is further lowered (against the biasing force of the compression coil spring 60) while being guided by (the outer periphery of the extending portion 22 of the guide bush 20). When the valve shaft holder 30 is lowered by a predetermined amount, the movable stopper 34 of the valve shaft holder 30 and the fixed stopper 24 of the guide bush 20 abut each other, and the lower stopper mechanism 29 restricts further lowering of the valve shaft holder 30. Ru. At this time, since the compression coil spring 60 interposed between the valve shaft holder 30 and the valve shaft 10 is compressed, the valve body 16 is strongly pressed against the valve seat 46a, and the valve closing property is secured. (Fully closed as shown in FIG. 1). Further, at this time, (the convex portion 35 of) the valve shaft holder 30 is separated from the fixing member 70 fixed to the valve shaft 10 by a predetermined gap in the elevating direction.

  On the other hand, when the motor-operated valve 1 is opened from the fully closed state, the stator coil 52c is energized by energizing in the other direction. Thus, the rotor 51 is relatively rotated in the direction opposite to the above with respect to the guide bush 20 fixed to the valve main body 40, and the valve shaft holder 30 is While being guided by (the outer periphery of) the installation portion 22 ascends. Here, (the convex portion 35 of the valve shaft holder 30 is positioned apart from the fixing member 70 fixed to the valve shaft 10 by a predetermined gap, so (the valve shaft holder 30 is lifted by the predetermined gap) In the meantime, while the valve body 14 is seated on the valve seat 46 a and the valve port 46 is closed (while the valve shaft 10 is at rest), the valve shaft holder 30 ascends.

  From the above state, the stator coil 52c is energized in the other direction to excite it, and when the valve shaft holder 30 is raised by the predetermined gap, (the upper surface of) the convex portion 35 provided on the ceiling portion 32 of the valve shaft holder 30 The valve shaft holder 30 abuts (rotates) the valve shaft 10 along with the valve shaft 10, and the lower end of the valve shaft 10 abuts against (the lower surface of the flange portion 72 of the fixing member 70 fixed to the valve shaft 10). Is moved upward, and the valve port 46 is opened.

  As described above, in the motor-operated valve 1 of the present embodiment, the valve shaft 10 is a portion (lower large diameter portion) on the lower side (valve body 14 side) than the terrace surface 13 on which the compression coil spring 60 as the biasing member is disposed. 12) is slidably inserted in the guide bush 20 and guided in the direction of the axis O (raising and lowering direction) only on the lower side (valve body 14 side) of the compression coil spring 60, and the valve shaft holder 30 (insertion hole 32a Contact resistance (sliding resistance) lower than, for example, a conventional motorized valve in which the valve shaft is guided by both the guide bush and the valve shaft holder above and below the biasing member. Can improve the operability.

  Further, the hole diameter of the insertion hole 32a of the valve shaft holder 30 in which the valve shaft 10 (the upper small diameter portion 11 thereof) is loosely fitted is larger than the inner diameter of the compression coil spring 60. Even when it occurs, the valve shaft 10 is guided by the compression coil spring 60, so that the contact resistance (sliding resistance) can be suppressed to a low level, and the operability can be improved. .

  In the above embodiment, although the motor-operated valve of the type in which the valve body 14 is seated on the valve seat 46a has been described, for example, when the valve body is in the fully lowered position (usually closed) The same function and effect as described above can be obtained in a closed valveless type motorized valve in which a gap of a predetermined size is formed between the valve and the valve seat (that is, the valve body is not seated on the valve seat). There is no need to mention it.

DESCRIPTION OF SYMBOLS 1 Motor-operated valve 10 Valve shaft 13 Stepper surface 14 Valve body 15 Large diameter connection part 20 Guide bush 21 Cylindrical part 23 Fixing screw part (male screw part)
24 fixed stopper body 28 screw feed mechanism 29 lower stopper mechanism 30 valve shaft holder 30 a protrusion 30 b locking surface 30 c taper surface 31 cylindrical portion 32 ceiling 33 movable screw (female screw)
34 movable stopper 35 convex portion 36 notch 40 valve main 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 50 stepping Motor 51 Rotor 52 Stator 55 Can 60 Compression coil spring (biasing member)
70 fixing member 71 fixing portion 71a small diameter upper portion 71b large diameter lower portion 72 flange portion O axis

Claims (5)

A valve stem provided with a valve body,
A guide bush in which the valve shaft is axially relatively movable and relatively rotatably inserted;
A valve body having a valve port with a valve seat to which the valve body contacts and separates, and to which the guide bush is attached and fixed;
A valve shaft holder mounted on the valve shaft;
A biasing member interposed between the terrace surface formed on the valve shaft and the valve shaft holder, for biasing the valve body in the valve closing direction;
A fixing member fixed to the valve stem so as to connect the valve stem holder to the valve stem, and brought into contact with the valve stem holder by the biasing force of the biasing member;
A motor having a rotor and a stator for rotating the valve shaft holder relative to the guide bush;
A screw feed mechanism provided between the guide bush and the valve shaft holder for moving the valve element of the valve shaft up and down with respect to the valve seat of the valve body according to the rotational drive of the rotor; A motor-operated valve comprising
The valve shaft is characterized in that a portion lower than the terrace surface is slidably inserted in the guide bush and axially guided only on the lower side of the biasing member. Motorized valve.   The motor-operated valve according to claim 1, wherein a portion of the valve shaft above the terraced surface is inserted into an insertion hole provided in the valve shaft holder with a predetermined gap. The biasing member is interposed between the terrace surface and the valve shaft holder so as to be extrapolated to a portion above the terrace surface of the valve shaft.
The motor-operated valve according to claim 2, wherein a hole diameter of the insertion hole is larger than an inner diameter of the biasing member.   The motor-operated valve according to claim 3, wherein an outer diameter of the biasing member is larger than a diameter of the insertion hole and a diameter of a portion of the valve shaft below the terrace surface.   A portion of the valve shaft to which the fixing member is fixed is larger in diameter than a portion of the valve shaft inserted in the insertion hole and smaller in diameter than the diameter of the insertion hole. The motor-operated valve according to any one of Items 2 to 4.

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