JP7177529B2 - electric valve - Google Patents

Description

The present invention relates to a motor-operated valve incorporated as a flow rate control valve or the like in a refrigeration cycle of an air conditioner, refrigerator, or the like, and in particular, the valve body is in the lowest position (normally fully closed). The present invention relates to a non-valve-closing type electrically operated valve in which a gap of a predetermined size is formed between itself and a valve seat portion.

This type of motor-operated valve includes, for example, a valve shaft, a guide stem having a cylindrical portion into which the valve shaft is inserted, and a cylindrical guide stem held and fixed to the lower end of the valve shaft and inserted into the guide stem. a valve holder, which is inserted in the valve holder so as to be axially movable and rotatable with respect to the valve shaft, and attached downward by a coil spring compressed between the valve shaft and the valve shaft; a valve body to which the guide stem is attached and fixed, and which has a valve body that is biased and retained by the valve holder to prevent it from slipping off, a valve seat portion that the valve body contacts and separates, and the guide stem that is attached and fixed to the valve body; a rotor disposed on the inner circumference of the can; a rotor holder connecting the rotor and the valve shaft via a coupling member externally fitted and fixed to the upper end of the valve shaft; a recess formed in the rotor holder for engagement with an engaging portion provided in the rotor holder; a stator disposed on the outer periphery of the can for rotationally driving the rotor; and a stator disposed on the inner periphery of the cylindrical portion of the guide stem a female threaded member, a fixed threaded portion formed on the inner periphery of the female threaded member, and a movable threaded portion formed on the outer periphery of the valve stem, for bringing the valve body into contact with and separating from the valve seat portion. a feed mechanism; and a stopper mechanism disposed on the outer periphery of the cylindrical portion of the guide stem and configured to restrict the rotational vertical movement of the rotor, the stopper mechanism having an upper locking portion and a lower locking portion. A spiral fixed stopper, a first contact portion that contacts and is locked with the upper side locking portion, and a second contact portion that is locked with the lower side locking portion are provided. and a ring-shaped or helical slider incorporated in the helical portion of the fixed stopper. By being pushed, the first contact portion contacts the upper engaging portion and the second contact portion contacts the lower engaging portion while rotating and moves up and down. At the original position where the second contact portion of the slider is stopped by contacting the lower locking portion, a gap of a predetermined size is formed between the valve body and the valve seat portion. is known (see, for example, Patent Literature 1).

In the air conditioner using the motor-operated valve having the configuration as described above, even when the valve body is in the lowest position (which is normally fully closed), there is a gap of a predetermined size between it and the valve seat. For example, when dehumidifying operation is performed late at night, the motor-operated valve can be operated with the amount of refrigerant throttled without fully closing the motor-operated valve. can be done. Moreover, the motor-operated valve having the above-described structure has the advantage of being able to reliably prevent the valve body from biting into the valve seat portion, as compared with a normal valve closing type motor-operated valve.

Japanese Patent No. 5164579

By the way, in the conventional non-valve closing type electric valve as described above, the rotor, which is connected and fixed to the valve shaft, is finally rotated in the valve closing direction until the slider is set at the origin position, and the valve body and the rotor are rotated. 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 origin position depends on the part accuracy of the component parts having complicated shapes such as the valve body and the valve body (the valve seat portion of the valve body). There was a possibility that the dimensional variation of the gap would increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to reduce dimensional variations in the gap formed between the valve body and the valve seat portion at the original position with a simple structure. To provide a motor-operated valve capable of suppressing.

In order to solve the above-described problems, an electrically operated valve according to the present invention is fixed to a male screw portion arranged on the side opposite to a valve seat portion with respect to a valve chamber and formed coaxially with the valve seat portion, and to the rotor side. a screw feed mechanism having a female thread portion screwed to the male thread portion; a valve body that is advanced and retracted with respect to the valve seat portion by the rotation of the rotor and the screw feed mechanism; a stopper mechanism for regulating the lower end position of the valve body, the stopper mechanism comprising: a lower stopper screwed onto the male threaded portion; and a stopper body, wherein the lower stopper is fixed at an intermediate position above the lower end position of the male threaded portion with a gap in the vertical direction from a stepped portion provided on the lower side of the male threaded portion. It is characterized by having

In a preferred aspect, the valve has a biasing member that normally biases the valve body toward the valve seat portion with respect to the rotor.

According to the present invention, after the lower stopper having the female threaded portion screwed to the fixed threaded portion of the guide bush is rotated in the valve opening direction with respect to the guide bush, the lower stopper is connected to the guide bush so as not to rotate relative to the guide bush. The lowest position of the valve disc, in other words, the gap between the valve disc and the valve seat when the valve disc 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 origin position basically depends on the dimensional accuracy of the female screw portion of the lower stopper and the fixed screw portion of the guide bush, which constitute the lower stopper mechanism. Therefore, compared with conventional electric valves in which the dimensional accuracy of the gap is determined by the component accuracy of components having complicated shapes, such as the valve body and the valve body, the dimensional variation of the gap can be suppressed. It is possible to improve the controllability of the fluid (refrigerant) flow rate in the low flow rate region.

1 is a longitudinal sectional view showing a first embodiment of an electrically operated valve according to the present invention; FIG. 2A is a longitudinal cross-sectional view showing a seated state, and FIG. FIG. 4 is a vertical cross-sectional view showing a separated state; FIG. 3 is a top view and a partially enlarged longitudinal sectional view for explaining a step of rotating the lower stopper with respect to the guide bush in the origin positioning step shown in FIG. 2; FIG. 2 is a partial enlarged vertical cross-sectional view showing another example of a stopper portion in the electrically operated valve shown in FIG. 1; FIG. 2 is a diagram showing flow characteristics of the motor-operated valve shown in FIG. 1; FIG. 5 is a vertical cross-sectional view showing a second embodiment of an electrically operated valve according to the present invention; It is a figure which shows the stopper presser of the electrically operated valve shown by FIG. 6, (A) is a perspective view, (B) is a top view. FIG. 7A is a perspective view showing a state in which a stopper presser is attached in a seated state, and FIG. FIG. (B) is a perspective view showing a state in which the stopper presser and the lower stopper are rotated from (A).

An embodiment of an electrically operated valve according to the present invention will be described below with reference to the drawings. In each drawing, gaps formed between members, separation distances between members, etc. may be exaggerated for the sake of easy understanding of the invention and for the convenience of drawing. be. Also, in this specification, descriptions indicating positions and directions such as up and down, left and right are based on the directional arrows shown in FIGS. 1 and 6, and do not indicate positions and directions in actual use.

[First embodiment]
FIG. 1 is a longitudinal sectional view showing a first embodiment of an electrically 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, a rotor 51 and a stator 52, a stepping motor 50, It includes a compression coil spring (biasing member) 60 , a retaining member 70 , a screw feed mechanism 28 , and a lower stopper mechanism 29 .

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. are integrally formed.

The guide bush 20 includes a cylindrical portion 21 in which (the middle large diameter portion 12 of) the valve shaft 10 is inserted in such a manner that it is relatively movable (slidable) in the direction of the axis O and relatively rotatable around the axis O; It extends upward from the upper end of the cylindrical portion 21, has an inner diameter larger than that of the cylindrical portion 21, and is inserted between the upper end of the intermediate large diameter portion 12 and the lower end of the upper small diameter portion 11 of the valve shaft 10. and a setting portion 22 . On the outer circumference of the cylindrical portion 21 of the guide bush 20, one side of a screw feeding mechanism 28 is provided 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 in accordance with the rotational drive of the rotor 51. A component fixing screw portion (male screw portion) 23 is formed. The lower portion of the cylindrical portion 21 (the portion below the fixing screw portion 23 ) has a large diameter and serves as a fitting portion 27 that fits into the fitting hole 44 of the valve body 40 . A lower stopper 25 is screwed onto (below the valve shaft holder 30 in) the fixed screw portion 23 with a predetermined gap h between the upper surface 27a of the fitting portion 27 and the outer periphery of the lower stopper 25. A fixed stopper body 24 that constitutes one side of a lower stopper mechanism 29 that regulates downward rotation of the valve stem holder 30 is integrally protruded. As will be described in detail later, in the present embodiment, the upper surface 27a of the fitting portion 27 restricts the downward movement of the lower stopper 25 (in other words, defines the limit position of downward movement to define the lower stopper in the seated state). 25) is a stopper portion.

The valve shaft holder 30 has a cylindrical portion 31 into which the guide bush 20 is inserted, and a ceiling portion 32 having 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. A movable threaded portion (female threaded portion) 33 is formed on the inner periphery of the cylindrical portion 31 of the valve stem holder 30 to form the screw feed mechanism 28 by being screwed with the fixed threaded portion 23 of the guide bush 20. A movable stopper body 34 constituting the other part of the lower stopper mechanism 29 is integrally protruded from the lower end of the outer periphery of the cylindrical portion 31 .

Between the terrace surface formed between the upper small-diameter portion 11 and the intermediate large-diameter portion 12 of the valve shaft 10 and the lower surface of the ceiling portion 32 of the valve shaft holder 30, an upper small-diameter portion of the valve shaft 10 is provided. The valve shaft 10 and the valve shaft holder 30 are urged in the upward/downward direction (the direction of the axis O) so as to be externally inserted into the portion 11, in other words, the valve shaft 10 (valve element 14) is always downward. A compression coil spring (biasing member) 60 that biases in the (valve closing direction) is compressed.

The valve main body 40 is composed of a metal cylindrical body such as brass or SUS. The valve main body 40 has a valve chamber 40a therein, and a first conduit 41a is connected and fixed by brazing or the like to a lateral first opening 41 provided on the side of the valve chamber 40a. The guide bush 20 and the through hole 43 through which the valve shaft 10 (middle large-diameter portion 12) is inserted in the ceiling portion of the valve shaft 10 so as to be relatively movable (slidable) in the direction of the axis O and relatively rotatable around the axis O. A fitting hole 44 is formed in which the lower portion (fitting portion 27) of the valve chamber 40a is fitted and fixed, and a second conduit 42a is brazed to a vertical second opening 42 provided at the bottom of the valve chamber 40a. A bottom wall 45 between the valve chamber 40a and the second opening 42 is formed with a valve opening orifice 46 having a valve seat portion 46a with which the valve body 14 contacts and separates.

A flange 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 stepped portion provided on the outer periphery of the flange plate 47. It is

A rotor 51 is rotatably disposed inside the can 55 and outside the guide bush 20 and the valve shaft holder 30. Yokes 52a, A stator 52 comprising a bobbin 52b, a stator coil 52c, a resin mold cover 52d, and the like is arranged. A plurality of lead terminals 52e are connected to the stator coil 52c, and a plurality of lead wires 52g are connected to these lead terminals 52e via a substrate 52f. A rotor 51 is arranged to rotate about an axis O. As shown in FIG.

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

Specifically, the rotor 51 has a double-tube structure including an inner cylinder 51a, an outer cylinder 51b, and a connecting portion 51c that connects the inner cylinder 51a and the outer cylinder 51b at a predetermined angular position around the axis O. Longitudinal grooves 51d extending in the direction of the axis O (vertical direction) are formed in the inner circumference of the inner cylinder 51a (for example, at angular intervals of 120 degrees around the axis O).

On the other hand, on the outer periphery (upper half portion) of the valve shaft holder 30, vertically extending ridges 30a are provided (for example, at angular intervals of 120 degrees around the axis O). On both sides, upward locking surfaces (not shown) that support the rotor 51 are formed.

When the vertical groove 51d of the inner cylinder 51a of the rotor 51 and the ridge 30a of the valve shaft holder 30 are engaged with each other, and the lower surface of the inner cylinder 51a of the rotor 51 and the locking surface of the valve shaft holder 30 are brought into contact with each other, The rotor 51 is supported and fixed in alignment with the valve stem holder 30 , and the valve stem holder 30 rotates together with the rotor 51 while supporting the rotor 51 within the can 55 .

Above the rotor 51 and the valve shaft holder 30, there is provided a valve shaft that prevents the valve shaft holder 30 and the rotor 51 from moving relative to each other in the vertical direction (in other words, presses the rotor 51 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 the push nut 71 and the rotor 51. and a disc-shaped rotor retainer 72 having an insertion hole 72a in the center through which the upper end of the valve shaft 10 is inserted. ing. That is, the rotor 51 is sandwiched between the valve stem holder 30 and the rotor retainer 72 which are urged upward by the urging force of the compression coil spring 60 . 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 51a of the rotor 51, and the ceiling portion 32 of the valve shaft holder 30 ) is in contact with the lower surface (flat surface) of the rotor retainer 72 .

In addition, the push nut 71 fixed to the upper end of the valve shaft 10 does not allow the valve shaft holder 30 to move excessively upward with respect to the guide bush 20 during operation. In order to prevent the shaft holder 30 from being disengaged from the movable threaded portion 33, a return spring 75 made of a coil spring that biases the valve shaft holder 30 toward the guide bush 20 is mounted.

In the motor-operated valve 1, the valve body 14 is moved to the lowest position (original position) in order to prevent the valve body 14 from biting the valve seat portion 46a and to ensure controllability in a low flow rate range. At some point, a gap of a predetermined size (a gap whose dimension in the vertical direction is H) is formed between the valve body 14 and the valve seat portion 46a.

Referring to FIG. 2, the assembly process of the motor-operated valve 1, particularly the process of setting the valve body 14 to the origin position (lowest position) will be described in detail. The spring 60, valve shaft holder 30, rotor 51, valve main body 40, etc. are assembled. At this time, the lower stopper 25 is screwed to the guide bush 20 so as to be relatively rotatable. At this stage, the lower stopper 25 may be placed in contact with the stopper portion 27a of the guide bush 20, or may be spaced apart from the stopper portion 27a. Next, the valve body 14 provided at the lower end of the valve stem 10 comes into contact with (seats on) the valve seat portion 46a, the compression coil spring 60 is slightly compressed, and the movable stopper body 34 and the lower stopper 25 of the valve stem holder 30 are released. , and until the lower stopper 25 (the lower surface of ) contacts the stopper portion 27 a of the guide bush 20 , the fixed screw portion 23 of the guide bush 20 and the movable screw portion 33 of the valve shaft holder 30 By using the screw feed mechanism 28 consisting of, the valve shaft holder 30, the rotor 51, and the valve shaft 10 are lowered while being rotated. With the valve shaft holder 30 thus arranged at the lowest position, the rotor retainer 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 position). state, see FIG. 2(A)).

Next, from the above seated state, the screw feed mechanism 28 is assembled with the valve shaft 10, the valve shaft holder 30, the rotor 51, the locking member 70 (push nut 71 and rotor retainer 72), etc. After removing it from the guide bush 20 by rotating it using . Then, after the lower stopper 25 is connected and fixed to the guide bush 20 (fixed screw portion 23 thereof) by welding, welding, adhesion, or the like so as not to rotate relative thereto, the screw feed mechanism 28 is used again to move the assembly to the guide bush. Assemble to 20. As a result, the position of the fixed stopper body 24 of the lower stopper 25 with respect to the guide bush 20 changes, so that the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 come into contact, and the valve shaft holder 30 is moved. Even when it is at the lowest position, a gap of a predetermined size (a gap whose dimension is 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 lifted and removed from the guide bush 20, the lower stopper 25 is rotated in the valve opening direction with respect to the guide bush 20 by a predetermined rotation angle, and the lower stopper 25 is welded to the guide bush 20.・Although it has been explained that the assembly is connected and fixed so as not to rotate relative to the guide bush 20 by bonding or the like, the lower stopper 25 is rotated by a predetermined rotation angle in the valve opening direction with respect to the guide bush 20 simply by raising the assembly with respect to the guide bush 20. The assembly can be removed from the guide bush 20 if it is possible to rotate the lower stopper 25 and to form a gap to the extent that the lower stopper 25 can be connected and fixed to the guide bush 20 by welding, welding, adhesion, or the like so as not to rotate relative to each other. No need to remove.

When a backlash-less (non-backlash) type screw portion is adopted for the female screw portion 26 of the lower stopper 25 and the fixing screw portion (male screw portion) 23 of the guide bushing 20, the valve body 14 and the valve seat portion 46a are The dimension H of the gap formed therebetween in the vertical direction matches or substantially 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 threaded portion is provided with backlash (play or backlash). 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-described embodiment, the lower stopper 25 is rotated in the valve opening direction (loosened) to position the valve body 14 at its origin. Since the lower stopper 25 rotates while being 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 match the gap h.

Specifically, as is well understood with reference to FIG. 3, the angle of rotation corresponding to the backlash between the female threaded portion 26 of the lower stopper 25 and the fixed threaded portion 23 of the guide bushing 20 is θb [°] (Fig. 180° in the illustrated example), the lower stopper 25 is brought into contact with the stopper portion 27a of the guide bush 20 and tightened in the origin positioning process (in this state, the female screw portion of the lower stopper 25 is tightened). 26 and the lower surface of the fixing screw portion 23 of the guide bush 20), rotate (loosen) the lower stopper 25 in the valve opening direction, and the rotation angle θb [°] corresponding to the backlash is reached. Then, (the lower surface of) the lower stopper 25 continues to abut on the stopper portion 27a of the guide bush 20 due to 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.

Suppose that the lower stopper 25 is fixed to the guide bush 20 within the range of the rotation angle θb [°] corresponding to the backlash, and the screw feed mechanism 28 is used to lower the valve shaft holder 30 while rotating it. When the movable stopper body 34 of the lower stopper 25 and the fixed stopper body 24 of the lower stopper 25 are brought into contact with each other, the lowest position of the valve shaft holder 30 gradually rises according to the amount of rotation of the lower stopper 25 . For example, the lift amount Hb of the lowest position of the valve shaft holder 30 at the time of backlash cancellation is p×θb/360, where p is the thread pitch (interval between screw threads) of the female screw portion 26 of the lower stopper 25. defined ((3) in FIG. 3).

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

Finally, when the lower stopper 25 is fixed to the guide bush 20 by rotating the lower stopper 25 in the valve-opening direction by the rotation angle θ from the state where the stopper portion 27 a of the guide bush 20 is abutted and tightened, the valve shaft holder 30 is fixed. Since the lowest position rises by the amount of rise H defined by p×θ/360, when the valve stem holder 30 is at the lowest position, there is a gap between the valve body 14 and the valve seat portion 46a in the upward/downward direction. A gap of dimension H at is formed. On the other hand, between the lower stopper 25 and the stopper portion 27a of the guide bush 20, there is a gap h obtained by subtracting the amount of backlash from the lift amount H, that is, the gap 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 27a of the guide bush 20 by rotating the lower stopper 25 beyond the rotation angle θb [°] corresponding to the backlash. However, if the dimension of the gap formed between the valve body 14 and the valve seat portion 46a in the vertical direction is set to Hb or less, the lower stopper 25 is within the range of the backlash rotation angle θb [°]. Therefore, a gap is not 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-described embodiment, the state in which the lower stopper 25 is brought into contact with the stopper portion 27a of the guide bush 20 and tightened is defined as the reference state of the rotation of the lower stopper 25 in the valve opening direction (that is, the seated state). However, it is a matter of course that the fastened state and vertical position of the lower stopper 25 in the reference state are not limited to the illustrated embodiment. For example, the reference state of the lower stopper 25 may be any state within the range of the rotation angle corresponding to the backlash shown in (1) to (3) of FIG. Further, the lower stopper 25 does not need to be in contact with the stopper portion 27a of the guide bush 20 in its reference state. Any position in may be taken as the reference state. When the state in which the lower stopper 25 is separated from (not in contact with) the stopper portion 27a of the guide bush 20 is defined as the reference state, the backlash does not exist, and after 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 portion 46a is smaller than the gap h between the lower stopper 25 (the lower surface) and the stopper portion 27a of the guide bush 20 (in other words, For example, the gap h in the vertical direction between the lower stopper 25 and the stopper portion 27a of the guide bush 20 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 by the upper surface of the fitting portion 27 of the guide bush 20. However, as shown in FIG. By forming an incomplete threaded portion 23a on the fixing threaded portion 23 (lower end) formed on the outer periphery, tightening of the female threaded portion 26 of the lower stopper 25 may be restricted to restrict downward movement of the lower stopper 25. .

In the motor-operated valve 1 having such a configuration, when the rotor 51 is rotated by energizing (the stator coil 52c of) the stator 52, the valve shaft holder 30 and the valve shaft 10 are rotated integrally therewith. At this time, the screw feed mechanism 28 consisting of the fixed threaded portion 23 of the guide bushing 20 and the movable threaded portion 33 of the valve shaft holder 30 causes the valve shaft 10 to move up and down together with the valve body 14 . and the valve seat portion 46a is increased or decreased to adjust the flow rate of fluid such as refrigerant. In addition, even when the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 fixed to the guide bush 20 are in contact with each other, the valve body 14 and the valve seat are kept even when the valve body 14 is at the lowest position. Since a gap (required lift amount when the valve is closed) is formed with the portion 46a, a predetermined flow rate is ensured (see FIG. 5).

As described above, in the electric valve 1 of the first embodiment, the lower stopper 25 having the female threaded portion 26 with the thread pitch p is screwed into a predetermined position of the guide bushing 20 so as to be relatively rotatable, and the lower stopper mechanism 29 operates the valve. When the shaft holder 30 is at the lowest movement position, the seated state in which the valve body 14 contacts the valve seat portion 46a, and the lower stopper 25 at the predetermined position is rotated by a predetermined amount with respect to the guide bush 20 in the valve opening direction. When it is rotated by an angle θ and connected to the guide bush 25 so as not to rotate relative to it, when the valve shaft holder 30 is at the lowest movement position by the lower stopper mechanism 29, between the valve body 14 and the valve seat portion 46a, Each part is designed so that it can take a separated state in which the dimension H in the vertical direction is defined by p×θ/360. After being rotated, the valve body 14 is connected to the guide bushing 20 so as not to rotate relative to each other, so that the valve body 14 is at its lowest position, in other words, the valve body 14 and the valve seat portion 46a when the valve body 14 is at its lowest position. A gap between is defined. That is, the dimensional accuracy of the gap between the valve body 14 and the valve seat portion 46a at the origin position is basically determined by the female screw 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, it is possible to suppress the dimensional variation of the gap, thereby improving the controllability of the fluid (refrigerant) flow rate in the low flow rate region.

[Second embodiment]
FIG. 6 is a vertical cross-sectional view showing a second embodiment of an electrically 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 and fixed to (the fixing screw portion 23 of) the guide bush 20, but in the present second embodiment. 2, the lower stopper 25 is engaged with the guide bush 20 (fixing screw of It is non-rotatably connected to the portion 23), and other configurations are substantially the same as those of the motor operated valve 1 of the first embodiment. Therefore, only the configuration related to the stopper presser 35 will be described in detail below, and the same configurations as those of the electrically operated valve 1 shown in FIG. The operation of the motor-operated valve 2 of the second embodiment is also the same as that of the motor-operated valve 1 of the first embodiment.

The stopper retainer (holding member) 35 in the electric valve 2 of the present embodiment is a disk-shaped member formed with an insertion hole 35a through which the lower stopper 25 is inserted, as will be understood with reference to FIG. A pair of support claws 36a and 36b are erected to sandwich the lower stopper 25 on the outer peripheral portion of the insertion hole 35a substantially opposite to the axis O (a position separated by approximately 180°). ing. The pair of support claws 36a and 36b are provided so as to face the outer surface of the lower stopper 25, and are relatively smaller than the pair of support claws 36a and 36b (the width and height in the circumferential direction are relatively small). The supporting claw 36b is adjacent to the fan-shaped portion 35b into which the fixing stopper body 24, which is fan-shaped in plan view, is inserted in the insertion hole 35a (specifically, the fixing stopper body 24 is inserted into the fan-shaped portion 35b). (adjacent to the side surface in the valve opening direction). In addition, the fixed stopper body 24 is formed on the outer peripheral portion of the fan-shaped portion 35b (more specifically, the portion adjacent to the side surface of the fixed stopper body 24 fitted into the fan-shaped portion 35b on the side opposite to the side surface of the fixed stopper body 24 in the valve opening direction). Supporting claws 36c are erected so as to face the outer surface of the fixing stopper member 24. The supporting claws 36c sandwich both side surfaces of the fixed stopper body 24 in the circumferential direction together with the supporting claws 36b.

The lower stopper 25 (the female screw portion 26 thereof) is screwed into (the fixing screw portion 23 of) the guide bush 20 in a relatively rotatable state, the stopper presser 35 is mounted on the lower stopper 25, and the support claws 36a, 36b, When the lower stopper 25 sandwiched by 36c is rotated around the axis O in the valve opening direction (counterclockwise in plan view in the illustrated example) together with the stopper retainer 35, the lower stopper 25 is raised while rotating (in some cases, only rotates and does not rise). In this state, when the stopper retainer 35 is joined and fixed to the brim-shaped portion 47 of the valve body 40 by welding, adhesion, adhesion, or the like, the lower stopper 25 rotates relative to the guide bush 20 (fixing screw portion 23 thereof). It is inoperably connected (see FIG. 6).

The support claws 36a, 36b, and 36c can be formed, for example, by bending a portion of the stopper presser 35 substantially vertically.

The process of assembling the electric valve 2, particularly the process of setting the valve body 14 to the origin position (lowest position), is first performed through the same processes as in the first embodiment to form the seated state. Next, from the seated state, the assembly in which the valve shaft 10, the valve shaft holder 30, the rotor 51, the locking member 70 and the like are integrated is raised while being rotated using the screw feed mechanism 28. After removing the stopper presser 35 from the guide bush 20 by pressing, the stopper presser 35 is mounted on the valve body 40 so as to be mounted on the lower stopper 25 (see FIG. 8A). is rotated by a predetermined rotation angle in the valve opening direction (see FIG. 8(B)). Then, after the stopper presser 35 is joined and fixed to the flange plate 47 of the valve body 40 by welding, welding, adhesion, or the like, and the lower stopper 25 is connected to (the fixing screw portion 23 of) the guide bush 20 so as not to rotate relative thereto. , the screw feed mechanism 28 is used again to assemble the assembly to the guide bush 20 . As a result, the position of the fixed stopper body 24 of the lower stopper 25 with respect to the guide bush 20 changes, so that the movable stopper body 34 of the valve shaft holder 30 and the fixed stopper body 24 of the lower stopper 25 come into contact, and the valve shaft holder 30 is moved. Even when the valve body 14 is at the lowest position, a gap of a predetermined size (a gap having a dimension H in the vertical direction) is formed between the valve body 14 and the valve seat portion 46a, and the separation state is the same as that of the first embodiment. is formed.

The stopper retainer 35 is attached to the lower stopper 25 at the stage of first 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, and the like. may be assembled together. Further, the stopper retainer 35 may be fixed to the guide bush 20 fixed to the valve body 40 instead of or together with the flange 47 of the valve body 40 .

Further, as described in the first embodiment with reference to FIG. 4, also in this embodiment, instead of the stopper portion 27a 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 an incomplete threaded portion 23a on the fixing threaded portion 23 (lower end) formed on the outer periphery, tightening of the female threaded portion 26 of the lower stopper 25 may be restricted to restrict downward movement of the lower stopper 25. Of course.

As described above, in the motor operated valve 2 of the second embodiment, the stopper retainer (holding member) 35 that prevents the relative rotation of the lower stopper 25 with respect to the guide bush 20 allows the lower stopper 25 to be attached to the guide bush 20. Since the positioning can be performed precisely, 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 portion 23 Fixed screw portion (male screw portion)
24 fixed stopper body 25 lower stopper 26 female screw portion 27 fitting portion 27a stopper portion (upper surface of fitting portion)
28 Screw feed mechanism 29 Lower stopper mechanism 30 Valve shaft holder 33 Movable threaded portion (female threaded portion)
34 movable stopper body 35 stopper retainer (holding 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 mouth orifice 46a Valve seat 47 Flange 50 Stepping motor 51 Rotor 52 Stator 55 Can 60 Compression coil spring (biasing member)
70 retaining member 71 push nut 72 rotor retainer O axis

Claims (2)

A screw feeding mechanism having a male screw portion disposed on the opposite side of the valve chamber from the valve seat portion and formed coaxially with the valve seat portion, and a female screw portion fixed to the rotor side and screwed into the male screw portion. When,
a valve body that is advanced and retracted with respect to the valve seat portion by rotation of the rotor and the screw feed mechanism;
a stopper mechanism that regulates the lower end position of the valve body with respect to the valve seat,
The stopper mechanism has a lower stopper screwed onto the male threaded portion, and a movable stopper body provided on the female threaded portion side so as to contact the lower stopper,
The motor-operated valve, wherein the lower stopper is fixed at an intermediate position above a lower end position of the male threaded portion with a gap in the vertical direction from a stepped portion provided on the lower side of the male threaded portion. . 2. The motor-operated valve according to claim 1, further comprising a biasing member that normally biases the valve body toward the valve seat portion with respect to the rotor.

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