JP6501609B2 - Motor-operated valve and method of assembling the same - Google Patents

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, etc., and in particular, the valve body is in the fully lowered position (usually closed). The present invention also relates to a valve-less type motor-operated valve in which a gap of a predetermined size is formed between the valve-seat portion and the valve-seat portion, and a method of assembling the same.

  As a motorized valve of this type, for example, a guide stem having a valve stem, a cylindrical portion into which the valve stem is inserted, and a cylindrical stem held and fixed at the lower end of the valve stem and inserted in the guide stem The valve holder is inserted into the valve holder so as to be capable of axial relative movement and relative rotation with respect to the valve shaft, and is attached downward by a coil spring compressed between the valve shaft and the valve shaft. A valve body that is biased and retained and locked by the valve holder, and a valve seat portion to which the valve body contacts and separates, and the guide stem is attached and fixed to the valve body A rotor disposed on the inner periphery of the can, a rotor holder for connecting the rotor and the valve shaft via a coupling member fixed to the upper end of the valve shaft, and the rotor Formed on the rotor holder in order to engage , A stator disposed on the outer periphery of the can for rotationally driving the rotor, a female screw member disposed on the inner periphery of the cylindrical portion of the guide stem, and a stationary member formed on the inner periphery of the female screw member A screw feed mechanism for contacting and separating the valve body from the valve seat portion, which comprises a screw portion and a movable screw portion formed on the outer periphery of the valve shaft, and is disposed on the outer periphery of the cylindrical portion of the guide stem A stopper mechanism for restricting rotational movement of the rotor, the stopper mechanism being in contact with the spiral fixing stopper having an upper locking portion and a lower locking portion, and the upper locking portion Ring-shaped or spiral-shaped, provided with a first contact portion to be locked and a second contact portion to be locked in contact with the lower locking portion, and incorporated into the spiral portion of the fixed stopper The slider, and the slider When the rotor rotates, the first contact portion is pushed by the pressing portion provided on the rotor, and the first contact portion is in contact with the upper locking portion and the second contact portion. Is moved up and down while rotating until it contacts the lower locking portion, and at the home position where the second contact portion of the slider is stopped by contacting the lower locking portion, It is known that a gap of a predetermined size is formed between the valve body and the valve seat portion (see, for example, Patent Document 1).

  In the air conditioner using the motor-operated valve having the configuration as described above, there is a gap of a predetermined size between the valve seat and the valve seat even when the valve body is at the lowest position (usually fully closed). As it is formed, for example, when dehumidifying operation is performed at midnight, it can be operated in a state where the amount of refrigerant is reduced without making the motor-operated valve fully closed, and suppressing generation of operation noise due to on / off Can. In addition, the motor-operated valve having the configuration as described above has an advantage that it is possible to reliably prevent the sticking of the valve body to the valve seat portion as compared with a normal valve-closing type motor-operated valve.

Patent No. 5164579 gazette

  By the way, in the conventional valve-less type motor-operated valve as described above, the rotor connected and fixed to the valve shaft is finally rotated in the valve-closing direction until the slider is set to the home position, A gap of the predetermined size is formed between the valve seat portion and the valve seat portion. Therefore, the dimensional accuracy of the gap between the valve body and the valve seat portion at the home position depends on the component accuracy of the component having a complicated shape such as the valve body and (the valve seat portion of) the valve body. There is a possibility that the dimensional variation of the gap becomes large.

  The present invention has been made in view of the above problems, and the object of the present invention is, with a simple configuration, the dimensional variation of the gap formed between the valve body and the valve seat portion at the origin position. It is providing the motor-operated valve which can be restrained, and its assembling method.

In order to solve the problems described above, the motor-operated valve according to the present invention is inserted in a state in which the valve shaft provided with a valve body at the lower end and the valve shaft can be relatively moved and relatively rotated in the axial direction. A valve body having a cylindrical portion, a valve seat portion to which the valve body contacts and separates, and a valve body to which the guide bush is attached and fixed, a cylindrical portion in which the guide bush is inserted, and an upper end portion of the valve shaft with insertion holes to be inserted and a ceiling portion that is pierced, the valve shaft holder is connected to airtightly stop engaging escape to the valve shaft, the valve shaft so as to urge the valve body in the valve closing direction And a biasing member interposed between the valve stem holder and the rotor, and a motor having a rotor and a stator for rotating the valve stem holder with respect to the guide bush, and an outer periphery of the guide bush Fixed screw and the valve shaft holder And a screw feed mechanism for moving the valve element of the valve shaft up and down with respect to the valve seat portion according to the rotational drive of the rotor, and a movable screw portion formed on the inner periphery; A fixed stopper body provided on a lower stopper having a female screw portion screwed to the fixed screw portion of the guide bush, and a movable stopper body provided on the valve shaft holder, in order to regulate the rotational downward movement. A lower stopper mechanism, and the lower stopper mechanism forms a gap between the valve body and the valve seat portion when the valve shaft holder is at the lowermost position and the valve body is at the lowermost position; an electric valve that is, the lower stopper the guide bush and the lower stopper before non-rotatably connected is screwed rotatably relative to the guide bush is arranged at a predetermined position, the When the parts stopper mechanism the valve shaft holder is in the lowermost position, takes a seating state in which the valve body is brought into contact with the valve seat, said lower stopper which is in the predetermined position relative to the guide bush When the valve stem holder is at the lowermost position by the lower stopper mechanism, the valve body and the valve seat portion are rotated when the valve shaft holder is in the lowermost position by the lower stopper mechanism. Each portion is separated so that the gap is defined such that the dimension in the vertical direction is defined by p × θ / 360, where p is the screw pitch of the female screw portion and θ is the predetermined rotation angle. It is characterized in that the dimensions and shape of are designed.

  In a preferred aspect, in the separated state, the lower stopper is directly joined to the guide bush and fixedly connected.

  In another preferred aspect, in the separated state, the lower stopper is connected to the guide bush via a pressing member that prevents relative rotation of the lower stopper with respect to the guide bush.

  In a further preferred aspect, the pressing member is joined and fixed to the guide bush or the valve body.

  In another preferable aspect, the guide bush is provided with a stopper portion for restricting the lower stopper against the guide bush, and the predetermined position is a position where the lower stopper abuts on the stopper portion. .

  In a further preferred aspect, the stopper portion is provided on the lower side of the lower stopper in the guide bush or on the fixing screw portion of the guide bush.

  In a further preferred aspect, in the separated state, the lower stopper contacts or separates from the stopper portion.

A method of assembling a motor-operated valve according to the present invention includes a valve shaft having a valve body at its lower end, and a guide bush having a cylindrical portion into which the valve shaft is inserted in a relatively movable and relatively rotatable state in the axial direction. A valve body having a valve seat portion to which the valve body contacts and separates, a valve body to which the guide bush is attached and fixed, a cylindrical portion into which the guide bush is inserted, and an insertion hole through which the upper end portion of the valve shaft is inserted A valve stem holder connected to the valve stem so as to prevent the valve stem from being closed, and the valve stem and the valve stem holder for biasing the valve body in the valve closing direction; A motor having a biasing member interposed therebetween, a rotor and a stator for rotating the valve shaft holder with respect to the guide bush, a fixed screw formed on the outer periphery of the guide bush, and the valve Formed on the inner circumference of the shaft holder A screw feed mechanism comprising a screw portion, for moving up and down the valve body of the valve shaft with respect to the valve seat portion according to the rotational drive of the rotor, and for performing a rotation downward movement restriction of the valve shaft holder A lower stopper mechanism including a fixed stopper body provided on a lower stopper having a female screw portion screwed to the fixed screw portion of the guide bush, and a movable stopper body provided on the valve shaft holder A method of assembling a motorized valve in which a gap is formed between the valve body and the valve seat portion when the valve shaft holder is at the lowermost position and the valve body is at the lowermost position by the lower stopper mechanism. a is, in a state in which they are not connected hermetically sealing engagement exits the valve shaft holder to said valve shaft, said lower stopper screwed rotatably relative to the guide bush arranged in a predetermined position, the lower Stopper machine By when the valve shaft holder is in the lowermost position, a step of Setto the valve body to the valve seat, step and you joined hermetically sealing engagement exits the valve shaft holder to the valve shaft And rotating the lower stopper at the predetermined position with respect to the guide bush in a valve opening direction by a predetermined rotation angle so as to be connected to the guide bush so as not to be relatively rotatable.

  According to the present invention, after the lower stopper having the female screw portion screwed to the fixed screw portion of the guide bush is rotated in the valve opening direction with respect to the guide bush, the lower stopper is connected non-rotatably to the guide bush. The lowest position of the valve body, in other words, the gap between the valve element and the valve seat when the valve element is at the lowest position, is defined. That is, the dimensional accuracy of the gap between the valve body and the valve seat portion at the home position basically depends on the dimensional accuracy of the internal thread portion of the lower stopper constituting the lower stopper mechanism and the fixing thread portion of the guide bush. Therefore, for example, the dimensional variation of the gap can be suppressed as compared with a conventional motorized valve in which the dimensional accuracy of the gap is determined by the component accuracy of the component having a complicated shape such as a valve body or a valve body. Controllability of fluid (refrigerant) flow rate in a low flow rate region can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows 1st Embodiment of the motor operated valve which concerns on this invention. FIG. 7 is a view provided for explaining a process for bringing out the origin position (the most lowered position) of the valve body in the assembly process of the motor-operated valve shown in FIG. 1; (A) is a longitudinal sectional view showing a sitting state; The longitudinal cross-sectional view which shows a separation state. FIG. 3A is a top view and a partial enlarged vertical cross-sectional view provided for explaining a step of rotating a lower stopper with respect to a guide bush in the origin positioning step shown in FIG. 2; The partially expanded longitudinal cross-sectional view which shows the other example of the stopper part in the motor operated valve shown by FIG. The figure which shows the flow characteristic of the motor-operated valve shown by FIG. The longitudinal cross-sectional view which shows 2nd Embodiment of the motor operated valve which concerns on this invention. It is a figure which shows the stopper press of the motor-operated valve shown by FIG. 6, (A) is a perspective view, (B) is a top view. FIG. 7 is a view provided for explaining the process of bringing out the origin position (the most lowered position) of the valve body in the assembly process of the motor-operated valve shown in FIG. The figure (B) is a perspective view which shows the state which rotated the stopper press and the lower stopper from (A).

  Hereinafter, embodiments of a motor-operated valve according to 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. 6 and does not indicate the position and direction in the actual use state.

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

  The motor-operated valve 1 of the illustrated embodiment mainly includes a valve shaft 10, a guide bush 20, a valve shaft holder 30, a valve body 40, a can 55, and a stepping motor 50 including a rotor 51 and a stator 52; A compression coil spring (biasing member) 60, a retaining member 70, a screw feed mechanism 28, and a lower stopper mechanism 29 are provided.

  The valve stem 10 has an upper small diameter portion 11, an intermediate large diameter portion 12, and a lower small diameter portion 13 from the upper side, and the lower end portion of the lower small diameter portion 13 has a stepped inverted conical valve body 14 Are integrally formed.

  The guide bush 20 is inserted in such a cylindrical portion 21 that (the intermediate large diameter portion 12 of the valve shaft 10 is capable of relative movement (sliding) in the direction of the axis O and relative rotation 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 middle 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. On the outer periphery of the cylindrical portion 21 of the guide bush 20, one of the screw feed mechanisms 28 for raising and lowering the valve body 14 of the valve shaft 10 with respect to the valve seat portion 46a of the valve main body 40 A fixing screw portion (male screw portion) 23 is formed. Further, the lower portion of the cylindrical portion 21 (the portion below the fixing screw portion 23) has a large diameter, and serves as a fitting portion 27 to the fitting hole 44 of the valve main body 40. The lower stopper 25 is screwed to the fixed screw portion 23 (in the lower side than the valve shaft holder 30 in the above) with a predetermined gap h between the upper surface 27 a of the fitting portion 27 and the outer periphery of the lower stopper 25. The fixed stopper body 24 which comprises one side of the lower stopper mechanism 29 which performs rotation downward movement control of the valve shaft holder 30 is integrally protrudingly provided by this. As described in detail later, in the present embodiment, the upper surface 27a of the fitting portion 27 regulates the downward movement of the lower stopper 25 (in other words, the downward movement limit position is defined and the lower stopper in the sitting state) The stopper portion defines the position of 25).

  The valve shaft holder 30 has a cylindrical portion 31 into which the guide bush 20 is inserted, and a ceiling portion 32 through which an insertion hole 32a through which the upper end portion of (the upper small diameter portion 11 of) the valve shaft 10 is inserted. Have. On the inner periphery of the cylindrical portion 31 of the valve shaft holder 30, a movable screw portion (female screw portion) 33 which is screwed with the fixed screw portion 23 of the guide bush 20 to constitute the screw feed mechanism 28 is formed. 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 small diameter of the valve shaft 10 is formed between the terraced surface 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 holder 30 are urged away from each other in the raising and lowering direction (direction of the axis O) so as to be extrapolated to the portion 11, in other words, the valve shaft 10 (valve body 14) is always downward A compression coil spring (biasing member) 60 which urges in the (valve closing direction) is contracted.

  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 inside, 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, and the valve chamber 40a (The intermediate large diameter portion 12 of the valve shaft 10 is relatively movable (slidable) in the direction of the axis O and is rotatable relative to the axis O in the ceiling portion of the valve hole 10 and the guide bush 20 The second conduit 42a is brazed to the vertically oriented second opening 42 provided at the lower portion of the valve chamber 40a. A valve port orifice 46 is formed on the bottom wall 45 between the valve chamber 40a and the second opening 42 and has a valve seat portion 46a which is in contact with and separated from the valve body 14 while being connected and fixed.

  A wedge-shaped plate 47 is fixed to the upper end of the valve body 40 by caulking or the like, and the lower end of a cylindrical can 55 with a ceiling is butt-welded to a step provided on the outer periphery of the wedge-shaped plate 47 It is done.

  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, A longitudinal groove 51 d extending in the direction of the axis O (vertical direction) (for example, at an angular interval of 120 degrees around the axis O) is formed on the inner periphery of the inner cylinder 51 a.

  On the other hand, on the outer periphery (upper half portion) of the valve shaft holder 30, a protrusion 30a extending in the vertical direction (for example, at an angular interval of 120 degrees around the axis O) is protruded. Upward locking surfaces (not shown) for supporting the rotor 51 are formed on both sides.

  The longitudinal groove 51 d of the inner cylinder 51 a of the rotor 51 engages with the projection 30 a of the valve shaft holder 30, and the lower surface of the inner cylinder 51 a of the rotor 51 abuts on the locking surface of the valve shaft holder 30. The rotor 51 is supported and fixed in a state of being aligned with the valve shaft holder 30, and the valve shaft holder 30 is rotated together with the rotor 51 while supporting the rotor 51 in the can 55.

  The relative movement between the valve shaft holder 30 and the rotor 51 in the vertical direction is prevented on the upper side of the rotor 51 and the valve shaft holder 30 (in other words, the rotor 51 is pressed downward against the valve shaft holder 30) In order to connect the shaft 10 and the valve shaft holder 30, a push nut 71 is externally fitted and fixed to the upper end portion of (the upper small diameter portion 11 of) the valve shaft 10 by press fitting / welding or the like. And a rotor retaining member 72 formed of a disc-like member formed at the center with an insertion hole 72a formed in the center thereof through which the upper end portion of the valve shaft 10 is inserted. ing. That is, 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 rotor presser 72. The height (in the vertical direction) from the upper end of the valve shaft holder 30 to the locking surface is the same as the height (in the vertical direction) of the inner cylinder 51 a of the rotor 51. The upper surface of the rotor holder 72 abuts on the lower surface (flat surface) of the rotor presser 72.

  Further, in the push nut 71 fixed to the upper end portion of the valve shaft 10, the valve shaft holder 30 is moved upward too much with respect to the guide bush 20 at the time of operation, and the fixing screw portion 23 of the guide bush 20 and the valve In order to prevent the threaded engagement with the movable screw portion 33 of the shaft holder 30 from being disengaged, a return spring 75 composed of a coil spring for biasing the valve shaft holder 30 toward the guide bush 20 is provided.

  Then, in the motor-operated valve 1, for example, the valve body 14 is at the lowest position (home position) in order to prevent the valve body 14 from sticking to the valve seat portion 46a and to ensure controllability in a low flow rate region. At a certain time, a gap of a predetermined size (a gap with a dimension of H in the vertical direction) is formed between the valve body 14 and the valve seat portion 46a.

  The assembling process of the motor-operated valve 1, in particular, the process of bringing out the home position (the most lowered position) of the valve body 14 will be described in detail with reference to FIG. The spring 60, the valve shaft holder 30, the rotor 51, the valve body 40 and the like are assembled. At this time, the lower stopper 25 is screwed to the guide bush 20 so as to be capable of relative rotation. The lower stopper 25 may be disposed in contact with the stopper portion 27a of the guide bush 20 at this stage, or may be spaced apart from the stopper portion 27a. Subsequently, the valve body 14 provided at the lower end portion of the valve shaft 10 abuts (seats) the valve seat portion 46 a, and the compression coil spring 60 is slightly compressed, and the movable stopper 34 and the lower stopper 25 of the valve shaft holder 30. Of the fixed bush 23 of the guide bush 20 and the movable screw 33 of the valve shaft holder 30 until the lower stopper 25 (the lower surface thereof) abuts on the fixed stopper body 24 of the guide bush 20. And the valve shaft holder 30, the rotor 51, and the valve shaft 10 are lowered while being rotated. Then, with the valve shaft holder 30 disposed at the lowermost position as described above, the rotor presser 72 is fitted to the upper end portion of the valve shaft 10 and the push nut 71 is externally fitted and fixed by press fitting, welding or the like (seating State, see FIG. 2 (A)).

  Next, the screw feed mechanism 28 is an assembly in which the valve shaft 10, the valve shaft holder 30, the rotor 51, the retaining member 70 (the push nut 71 and the rotor presser 72) and the like are integrated from the seating state. The lower stopper 25 is rotated relative to the guide bush 20 by a predetermined rotation angle in the valve opening direction (in the illustrated example, in a counterclockwise direction in a plan view). . Then, after the lower stopper 25 is connected and fixed to (the fixing screw portion 23 of) the guide bush 20 by welding, welding, adhesion or the like so as not to be relatively rotatable, the assembly is Assemble to 20. As a result, the position of the lower stopper 25 relative to the guide bush 20 of the fixed stopper body 24 changes, so the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 abut each other. Even when in the lowest position, a gap of a predetermined size (a gap with a size of H in the vertical direction) is formed between the valve body 14 and the valve seat portion 46a (separated state, see FIG. 3B) ). After the assembly is raised and removed from the guide bush 20, the lower stopper 25 is rotated relative to the guide bush 20 in the valve opening direction by a predetermined rotation angle, and the lower stopper 25 is welded and welded to the guide bush 20. · Although it has been described that coupling and fixing is performed so as not to be relatively rotatable by adhesion or the like, only by raising the assembly relative to the guide bush 20, the lower stopper 25 has a predetermined rotational angle in the valve opening direction with respect to the guide bush 20 The assembly can be formed from the guide bush 20 as long as it can be rotated and a gap can be formed so as to connect and fix the lower stopper 25 to the guide bush 20 in a relatively non-rotatable manner by welding, welding, adhesion or the like. There is no need to remove it.

  When a backlash-less (non-backlash) type screw portion is adopted as the female screw portion 26 of the lower stopper 25 or the fixed screw portion (male screw portion) 23 of the guide bush 20, the valve body 14 and the valve seat 46a The dimension H of the gap formed between the lower and upper stoppers 25 in the vertical direction matches or almost matches the gap h between the lower surface of the lower stopper 25 and the stopper portion 27 a of the guide bush 20. However, in general, the screw portion is provided with backlash (play or play). Therefore, when the lower stopper 25 is brought into contact with the stopper portion 27a of the guide bush 20 and tightened as in the above embodiment, and then it is rotated in the valve opening direction (loosely) to locate the home position of the valve body 14, Since the lower stopper 25 rotates while in contact with the stopper portion 27a of the guide bush 20 (that is, without rising) at the initial stage of rotation, the dimension H does not necessarily coincide with the gap h.

  Specifically, as can be understood well with reference to FIG. 3, the rotation angle of the backlash between the female screw 26 of the lower stopper 25 and the fixed screw 23 of the guide bush 20 is θb [°] (figure In the illustrated example, when the angle is about 180 °, the lower stopper 25 is brought into contact with the stopper portion 27a of the guide bush 20 and tightened in the above-described home position locating step (in this state, the female screw portion of the lower stopper 25) When the lower stopper 25 is rotated (loosely) in the valve opening direction from the upper surface side of the guide bush 20 and the lower surface side of the fixed screw portion 23 of the guide bush 20, the rotation angle .theta.b [.degree. Then, the lower stopper 25 (the lower surface) of the lower stopper 25 keeps in contact with the stopper portion 27a of the guide bush 20 by its own weight ((1) to (3) in FIG. 3). However, since the lower stopper 25 itself rotates, the rotational position of the fixed stopper body 24 provided on the lower stopper 25 changes.

  Temporarily, the lower stopper 25 is fixed to the guide bush 20 within the range of the rotation angle θb [°] for this backlash, and the valve shaft holder 30 is lowered while being rotated by using the screw feed mechanism 28. When the movable stopper 34 and the fixed stopper 24 of the lower stopper 25 are brought into contact with each other, the lowermost position of the valve shaft holder 30 is gradually raised according to the amount of rotation of the lower stopper 25. For example, the amount Hb of increase of the lowermost position of the valve shaft holder 30 at the backlash offset time is p × θb / 360, where p is the thread pitch of the internal thread 26 of the lower stopper 25 (interval between threads). It is specified ((3) in FIG. 3).

  After the backlash is canceled (after the rotation angle of the lower stopper 25 reaches the rotation angle θb [°] for backlash) (in this state, the fixing screw of the lower surface of the female screw 26 of the lower stopper 25 and the guide bush 20) When the lower stopper 25 is further rotated in the valve opening direction, the lower stopper 25 starts to rise while rotating, and a gap is formed between the lower stopper 25 and the stopper portion 27 a of the guide bush 20. h is formed.

  Finally, assuming that the lower stopper 25 is brought into contact with the stopper portion 27a of the guide bush 20 and tightened, the lower stopper 25 is rotated in the valve opening direction by the rotation angle θ and fixed to the guide bush 20. Since the lowest position is raised by the rising amount H defined by p × θ / 360, when the valve shaft holder 30 is at the lowest position, the raising and lowering direction is established between the valve body 14 and the valve seat 46a. A gap of H in size is formed. On the other hand, between the lower stopper 25 and the stopper portion 27a of the guide bush 20, a clearance h obtained by subtracting the backlash component from the amount of increase H, that is, a clearance h defined by p × (θ−θb) / 360 Is formed.

  In the illustrated embodiment, a gap h is formed between the lower stopper 25 and the stopper portion 27 a of the guide bush 20 by rotating the lower stopper 25 beyond the rotation angle θb [°] for the backlash. However, when the dimension in the raising and lowering direction of the gap formed between the valve body 14 and the valve seat portion 46a is set to the above Hb or less, the lower stopper 25 is within the range of the rotation angle .theta.b [.degree. Therefore, no gap is formed between the lower stopper 25 and the stopper portion 27a of the guide bush 20, and (the lower surface of the lower stopper 25 remains in contact with the stopper portion 27a of the guide bush 20). .

  Further, in the above embodiment, the state in which the lower stopper 25 is in contact with the stopper portion 27a of the guide bush 20 and tightened is the reference state of rotation of the lower stopper 25 in the valve opening direction (that is, the above-mentioned sitting state). However, it goes without saying that the fastening state and the position in the vertical direction of the lower stopper 25 in the reference state are not limited to the illustrated embodiment. For example, the lower stopper 25 may use any state within the range of the rotation angle for the backlash shown in (1) to (3) of FIG. 3 as a reference state. Further, the lower stopper 25 does not have to be in contact with the stopper portion 27a of the guide bush 20 in the reference state, and for example, the (fixed screw portion 23 of the guide bush 20) as shown in FIG. Any position in may be taken as a reference state. When the lower stopper 25 is separated (not in contact) with the stopper portion 27a of the guide bush 20 as the reference state, the backlash does not exist, and after the assembly is completed (that is, the separated state) The dimension H in the vertical direction of the gap formed between the valve body 14 and the valve seat 46a is smaller than the gap h between (the lower surface of) the lower stopper 25 and the stopper 27a of the guide bush 20 (in other words, For example, the gap h between the lower stopper 25 and the stopper portion 27a of the guide bush 20 in the elevating direction becomes larger than the dimension H).

  In the illustrated embodiment, the downward movement of the lower stopper 25 is restricted by the stopper portion 27a formed of the upper surface of the fitting portion 27 of the guide bush 20. However, as shown in FIG. By forming the incomplete screw portion 23a on (the lower end of) the fixing screw portion 23 formed on the outer periphery, the tightening of the female screw portion 26 of the lower stopper 25 may be limited to restrict the downward movement of the lower stopper 25. .

  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) 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, 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 abut, and the valve body 14 is at the lowest position, the valve body 14 and the valve seat Since a gap (valve closing required lift amount) is formed between the portion 46a, a predetermined amount of passing flow rate is secured (see FIG. 5).

  As described above, in the motor-operated valve 1 according to the first embodiment, the lower stopper 25 having the female screw portion 26 of the screw pitch p is screwed to a predetermined position of the guide bush 20 relatively rotatably. When the shaft holder 30 is at the lowermost position, the valve seat 14 abuts against the valve seat portion 46a, and the lower stopper 25 at the predetermined position rotates a predetermined amount in the valve opening direction with respect to the guide bush 20 When the valve shaft holder 30 is at the lowermost position by the lower stopper mechanism 29, when it is rotated by an angle θ and connected to the guide bush 25 so as not to be relatively rotatable, between the valve body 14 and the valve seat 46a, Each part is designed such that the lower stopper 25 is a guide bush 20 so as to be capable of taking a separated state in which a gap defined by the dimension H in the vertical direction is defined by p × θ / 360. With respect to the valve bush 14 and the valve body 14 in the lowest position, the valve body 14 is in the lowest position by being connected to the guide bush 20 so as not to be relatively rotatable after being rotated in the valve opening direction. A gap between the valve seat portion 46a is defined. That is, the dimensional accuracy of the gap between the valve body 14 and the valve seat portion 46 a at the origin position is basically the same as that of the internal thread portion 26 of the lower stopper 25 and the fixing screw portion 23 of the guide bush 20 which constitute the lower stopper mechanism 29. Since it depends on the dimensional accuracy, the dimensional variation of the gap can be suppressed, and the controllability of the fluid (refrigerant) flow rate in the low flow rate area can be improved.

  Further, by integrally forming the rotor presser 72 and the positioning portion 73, it is possible to prevent an increase in the number of parts.

Second Embodiment
FIG. 6 is a longitudinal sectional view showing a second embodiment of the motor-operated valve according to the present invention.

  In the motor-operated valve 1 of the first embodiment, the lower stopper 25 provided with the fixed stopper body 24 is directly joined to (fixed screw portion 23 of) the guide bush 20 and connected and fixed. However, the second embodiment In the motor-operated valve 2, the lower stopper 25 is fixed to the guide bush 20 via a stopper pressing (pressing member) 35 that engages with the lower stopper 25 to prevent relative rotation of the lower stopper 25 with respect to the guide bush 20. The other components are substantially the same as those of the motor operated valve 1 of the first embodiment. Therefore, in the following, only the configuration related to the stopper retainer 35 will be described in detail, and the same components as those of the motor-operated valve 1 shown in FIG. The operation of the motor-operated valve 2 of the second embodiment is the same as that of the motor-operated valve 1 of the first embodiment.

  The stopper pressing (pressing member) 35 in the motor-operated valve 2 according to the present embodiment is a disk-shaped member in which a fitting insertion hole 35a through which the lower stopper 25 is inserted is formed, as will be understood well with reference to FIG. A pair of support claws 36a and 36b are erected to hold the lower stopper 25 on the opposite side (a position separated by about 180.degree.) To the axis O in the outer peripheral portion of the insertion hole 35a. ing. The pair of support claws 36a and 36b are provided to face the outer surface of the lower stopper 25 and, of the pair of support claws 36a and 36b, are relatively small (the circumferential width and height are relatively small. (Small) the support claw 36b is adjacent to the fan-shaped portion 35b in which the fixed stopper body 24 in a plan view in the insertion hole 35a is inserted (specifically, the fixed stopper body 24 inserted in the fan-shaped portion 35b) (Adjacent to the side face in the valve opening direction) of In addition, a fixed stopper body 24 is provided on an outer peripheral portion of the fan-shaped portion 35b (specifically, a portion adjacent to the side surface opposite to the side surface of the fixed stopper body 24 inserted in the fan-shaped portion 35b in the valve opening direction). Support claws 36c are erected so as to face the outer surface of the support claw 36c, and the support claws 36c clamp both side surfaces in the circumferential direction of the fixed stopper body 24 together with the support claws 36b.

  Lower screw 25 (of female screw 26) is screwed on (a fixed screw 23 of (the fixed screw 23 of) guide bush 20) in a relatively rotatable state, and the stopper presser 35 is covered with lower screw 25 and supporting claws 36a, 36b, When the lower stopper 25 held by 36c is rotated together with the stopper presser 35 in the valve opening direction (counterclockwise in a plan view in the illustrated example, about the axis O), the lower stopper 25 rotates and ascends (in some cases) Does not rise, only rotating). In this state, when the stopper presser 35 is joined and fixed to the flange portion 47 of the valve main body 40 by welding, welding, adhesion or the like, the lower stopper 25 rotates relative to the (guide screw 20 of the guide bush 20). Impossible to be linked (see FIG. 6).

  Each of the support claws 36a, 36b, 36c can be formed, for example, by a bending process in which a part of the stopper presser 35 is bent substantially vertically.

  When the assembling process of the motor-operated valve 2, particularly, the process of bringing out the home position (the most lowered position) of the valve body 14 is outlined, first, the seating state is formed through the same process as the first embodiment. Next, from the seating state, the assembly including the valve shaft 10, the valve shaft holder 30, the rotor 51, the retaining member 70 and the like is integrally raised while being rotated using the screw feed mechanism 28. After removing it from the guide bush 20, the stopper presser 35 is mounted on the valve main body 4 so as to cover the lower stopper 25 (see FIG. 8A). The valve is rotated by a predetermined rotation angle in the valve opening direction (see FIG. 8B). Then, after the stopper presser 35 is joined and fixed to the hooked plate 47 of the valve main body 40 by welding, welding, adhesion or the like, and the lower stopper 25 is connected to the guide bush 20 (the fixing screw portion 23 thereof) relatively nonrotatably The assembly is assembled to the guide bush 20 using the screw feed mechanism 28 again. As a result, the position of the lower stopper 25 relative to the guide bush 20 of the fixed stopper body 24 changes, so the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 abut each other. Even in the lowest position, a gap of a predetermined size (a gap of H in the raising and lowering direction) is formed between the valve body 14 and the valve seat portion 46a, and the separated state as in the first embodiment. Is formed.

  The stopper presser 35 is externally mounted on the lower stopper 25 at the stage of assembling the valve shaft 10, the guide bush 20, the lower stopper 25, the compression coil spring 60, the valve shaft holder 30, the rotor 51, the valve body 40, etc. first. It may be assembled. Further, the stopper presser 35 may be fixed to the guide bush 20 fixed to the valve main body 40 instead of or together with the collar-like portion 47 of the valve main body 40.

  Further, as described based on FIG. 4 in the first embodiment, in the present embodiment as well, instead of the stopper portion 27 a formed of the upper surface of the fitting portion 27 of the guide bush 20, the cylindrical portion 21 of the guide bush 20 is By forming the incomplete screw portion 23a on (the lower end of) the fixing screw portion 23 formed on the outer periphery, the tightening of the female screw portion 26 of the lower stopper 25 may be limited to restrict the downward movement of the lower stopper 25. Of course.

  As described above, in the motor operated valve 2 of the second embodiment, the lower stopper 25 is used as the guide bush 20 by utilizing the stopper pressing (pressing member) 35 that prevents the relative rotation of the lower stopper 25 with respect to the guide bush 20. On the other hand, since the precise positioning can be performed, the dimensional variation of the gap can be suppressed more effectively.

1, 2 Motor-operated valve 10 Valve shaft 14 Valve body 20 Guide bush 21 Cylindrical part 23 Fixing screw part (male screw part)
24 fixed stopper body 25 lower stopper 26 female screw 27 fitting portion 27 stopper portion (upper surface of fitting portion)
28 screw feed mechanism 29 lower stopper mechanism 30 valve shaft holder 33 movable screw portion (female screw portion)
34 Movable stopper body 35 stopper presser (presser member)
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 orifice 46a valve seat portion 47 collar portion 50 stepping motor 51 rotor 52 Stator 55 Can 60 Compression coil spring (biasing member)
70 Retaining retaining member 71 Push nut 72 Rotor press O axis

Claims (8)

A valve stem provided with a valve body at its lower end,
A guide bush having a cylindrical portion 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 valve seat portion to which the valve body contacts and separates, and to which the guide bush is attached and fixed;
And having a said guide bush ceiling portion insertion hole is formed through the upper end of the valve shaft and the cylindrical portion is inserted to be interpolated, the valve shaft holder that is connected to airtightly stop engaging escape to the valve shaft When,
A biasing member interposed between the valve stem and the valve stem holder for biasing the valve disc in the valve closing direction;
A motor having a rotor and a stator for rotating the valve shaft holder relative to the guide bush;
It consists of a fixed screw formed on the outer periphery of the guide bush and a movable screw formed on the inner periphery of the valve shaft holder, and the valve element of the valve shaft is moved to the valve seat according to the rotational drive of the rotor. A screw feed mechanism for raising and lowering the unit
A fixed stopper body provided on a lower stopper having a female screw portion screwed to the fixing screw portion of the guide bush so as to restrict the rotational movement of the valve shaft holder, and a movable stopper provided on the valve shaft holder A lower stopper mechanism comprising a stopper body;
The motor-operated valve in which a gap is formed between the valve body and the valve seat portion when the valve shaft holder is at the lowermost position and the valve body is at the lowermost position by the lower stopper mechanism .
Before the lower stopper is connected to the guide bush so as not to be able to rotate relative to the guide bush, the lower stopper is screwed relative to the guide bush so as to be disposed at a predetermined position, and the lower valve mechanism is the lowermost by the lower stopper mechanism. When in the dynamic position, the valve body is in a seating state in which the valve body abuts on the valve seat portion, and the lower stopper in the predetermined position is rotated by a predetermined rotation angle in the valve opening direction with respect to the guide bush. When the valve shaft holder is at the lowermost position by the lower stopper mechanism, the screw pitch of the female screw portion is set between the valve body and the valve seat when the lower stopper mechanism is connected to the guide bush so as not to allow relative rotation. p, wherein the predetermined rotational angle as theta, as may take separating state in which the gap dimension in the elevation direction is defined by p × θ / 360 are formed, each unit of the dimensions type There electric valve, characterized in that it is designed.   The motor-operated valve according to claim 1, wherein the lower stopper is directly joined to the guide bush and fixedly connected in the separated state.   The motor-operated valve according to claim 1, wherein the lower stopper is connected to the guide bush via a pressing member that prevents relative rotation of the lower stopper with respect to the guide bush in the separated state.   The motor operated valve according to claim 3, wherein the pressing member is joined and fixed to the guide bush or the valve main body.   The guide bush is provided with a stopper portion for restricting the downward movement of the lower stopper with respect to the guide bush, and the predetermined position is a position where the lower stopper abuts on the stopper portion. The motor operated valve according to any one of claims 1 to 4.   The motor-operated valve according to claim 5, wherein the stopper portion is provided on the lower side of the lower stopper in the guide bush or on the fixed screw portion of the guide bush.   The motor-operated valve according to claim 5, wherein the lower stopper abuts or is separated from the stopper portion in the separated state. A valve stem provided with a valve body at its lower end,
A guide bush having a cylindrical portion 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 valve seat portion to which the valve body contacts and separates, and to which the guide bush is attached and fixed;
And having a said guide bush ceiling portion insertion hole is formed through the upper end of the valve shaft and the cylindrical portion is inserted to be interpolated, the valve shaft holder that is connected to airtightly stop engaging escape to the valve shaft When,
A biasing member interposed between the valve stem and the valve stem holder for biasing the valve disc in the valve closing direction;
A motor having a rotor and a stator for rotating the valve shaft holder relative to the guide bush;
It consists of a fixed screw formed on the outer periphery of the guide bush and a movable screw formed on the inner periphery of the valve shaft holder, and the valve element of the valve shaft is moved to the valve seat according to the rotational drive of the rotor. A screw feed mechanism for raising and lowering the unit
A fixed stopper body provided on a lower stopper having a female screw portion screwed to the fixing screw portion of the guide bush so as to restrict the rotational movement of the valve shaft holder, and a movable stopper provided on the valve shaft holder A lower stopper mechanism comprising a stopper body;
A method of assembling an electric valve, wherein a gap is formed between the valve body and the valve seat portion when the valve shaft holder is at the lowermost position and the valve body is at the lowermost position by the lower stopper mechanism. There,
While not being connected hermetically sealing engagement exits the valve shaft holder to the valve axis, wherein the lower stopper screwed rotatably relative to the guide bush arranged in a predetermined position, said by the lower stopper mechanism Bringing the valve body into contact with the valve seat portion when the valve stem holder is in the lowermost position;
A step you connected hermetically sealing engagement exits the valve shaft holder to the valve shaft,
And d) rotating the lower stopper at the predetermined position relative to the guide bush in a valve opening direction by a predetermined rotation angle to connect the lower guide with the guide bush so as not to be relatively rotatable. .

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