JP2011163376A - Motor-operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost and highly reliable motor-operated valve which hardly causes malfunctions such as bite-in and locking despite a relatively simple constitution. <P>SOLUTION: A rotor 30 is so formed as to inhibit vertical movement while being freely rotatably supported in a guide member 60. A fixed stopper 17 is provided to the rotor 30. A moving stopper 13 is provided to a valve rod 10. While the valve rod 10 and moving stopper 13 rotate integrally with the rotor 30 and fixed stopper 17, screw feeding is performed in a vertical direction by a screw feeding mechanism 11. When the valve rod 10 is lowered to a predetermined position by this screw feeding, the moving stopper 13 is butted with and locked to the fixed stopper 17. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an electric valve used by being incorporated in an air conditioner, a refrigerator, or the like, and in particular, a type in which a valve rod (valve element) is contacted and separated from a valve seat by screw feed using rotation of a rotor. It relates to an electric valve.

  A conventional example of this type of electric valve is shown in FIG. The illustrated motor-operated valve 1 ′ is provided with a valve rod 25 integrally provided with a valve body 24 at a lower end portion and a valve seat 22 with which the valve body 24 contacts and separates, and a valve formed on the valve seat 22. A valve body 20 having a valve chamber 21 into which a refrigerant is introduced via a port 22a, a can 40 having a lower end sealed to the valve body 20, and a predetermined gap α is formed in the inner periphery of the can 40. The rotor 30 disposed in this manner, the stator 50 externally fitted to the can 40 for rotationally driving the rotor 30, and the rotor 30 and the valve body 24 are disposed between the rotor 30 and the rotor 30. And a screw feed mechanism for bringing the valve body 24 into and out of contact with the valve seat 22, and the flow rate is controlled by changing the lift amount of the valve body 24 with respect to the valve seat 22.

  Conduits 46 and 47 are connected and fixed to one side and lower end of the valve body 20, respectively.

  The stator 50 includes a yoke 51, a bobbin 52, a stator coil 53, a resin mold cover 56, and the like, and the rotor 30, the stator 50, and the like constitute a stepping motor.

  A support ring 36 is integrally coupled to the rotor 30, and a cylindrical valve stem holder 32 is formed on the support ring 36 at a lower opening disposed on the outer periphery of the valve stem 25 and the guide bush 26. The upper protrusion is caulked and fixed, whereby the rotor 30, the support ring 36, and the valve stem holder 32 are integrally connected.

  The screw feed mechanism is a cylinder in which a lower end portion 26a is press-fitted and fixed in a fitting hole 29 provided in the valve body 20, and a valve rod 25 (a lower large diameter portion 25a thereof) is slidably inserted. A fixed screw portion (male screw portion) 28 formed on the outer periphery of the guide bush 26 and a moving screw portion (female screw portion) formed on the inner periphery of the valve stem holder 32 and screwed into the fixed screw portion 28. 38).

  The upper small diameter portion 26b of the guide bush 26 is inserted into the upper portion of the valve rod holder 32, and the upper small diameter portion of the valve rod 25 is formed at the center of the ceiling portion 32a of the valve rod holder 32 (through hole formed therein). 25b is inserted. A push nut 33 is press-fitted and fixed to the upper end portion of the upper small diameter portion 25b of the valve rod 25.

  The valve stem 25 is extrapolated to the upper small diameter portion 25b of the valve rod 25, and between the ceiling portion 32a of the valve rod holder 32 and the upper terrace surface of the lower large diameter portion 25a of the valve rod 25. The retracted valve closing spring 34 is always biased downward (in the valve closing direction).

  A return spring 35 made of a coil spring is provided on the outer periphery of the push nut 33 on the ceiling portion 32 a of the valve stem holder 32. The return spring 35 is in pressure contact with the inner surface of the ceiling 40a of the can 40 when the valve rod holder 32 is further rotated and rotated together with the rotor 30 even after being substantially fully opened. Thus, when the fixing screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve stem holder 32 are disengaged (so-called unscrewing), the rotor is urged downward. By reversely rotating (lowering) 30, the fixing screw portion 28 and the moving screw portion 38 work again to be restored.

  The guide bush 26 has a lower stopper body (fixed stopper) 27 that constitutes one of rotation lowering stopper mechanisms for preventing further rotation lowering when the rotor 30 is rotated downward to a predetermined valve closing position. Is fixed, and an upper stopper body (moving stopper) 37 constituting the other of the stopper mechanism is fixed to the valve stem holder 32.

  The valve closing spring 34 is used to obtain a required seal pressure (valve leakage prevention) in a closed state where the valve body 24 is seated on the valve seat 22 and when the valve body 24 comes into contact with the valve seat 22. Deployed to alleviate the impact.

  In the motor-operated valve 1 ′ having such a configuration, the energizing excitation pulse is supplied to the stator coils 53, 53 in the first mode, so that the rotor is moved against the guide bush 26 fixed to the valve body 20. 30 and the valve stem holder 32 are rotated in one direction, and, for example, the valve stem holder 32 is moved downward (lowered) by screw feed between the fixing screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve stem holder 32. Then, the valve body 24 is pressed against the valve seat 22 to close the valve port 22a (fully closed state).

  When the valve port 22a is closed, the upper stopper body 37 is not yet in contact with the lower stopper body 27, and the rotor 30 and the valve stem holder 32 are further rotated and lowered while the valve body 24 is closing the valve port 22a. . In this case, the valve stem 25 (valve element 24) does not descend, but the valve stem holder 32 descends, so that the valve closing spring 34 is compressed by a predetermined amount, and as a result, the valve element 34 is strongly pressed against the valve seat 22. At the same time, the upper stopper body 37 comes into contact with the lower stopper body 27 due to the lowering of the rotation of the valve stem holder 32, and then the lowering of the rotation of the valve stem holder 32 is forcibly stopped even if the pulse supply to the stator coils 53, 53 is continued. Is done.

  On the other hand, when the energization excitation pulse is supplied to the stator coils 53, 53 in the second mode, the rotor 30 and the valve stem holder 32 are rotated in the opposite direction to the guide bush 26 fixed to the valve body 20, By the screw feed between the fixing screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve stem holder 32, the valve stem holder 32 is moved upward (raised) this time. In this case, since the valve closing spring 34 is compressed by a predetermined amount as described above at the time when the rotation of the valve stem holder 32 starts to rise (when pulse supply starts), the valve closing spring 34 is expanded by the predetermined amount. The valve body 24 does not leave the valve seat 22 and remains in the closed state (lift amount = 0). Then, after the valve closing spring 34 is extended by the predetermined amount, when the valve stem holder 32 is further rotated and raised, the valve body 24 is separated from the valve seat 22, the valve port 22a is opened, and the refrigerant is supplied to the valve port 22a. Pass through. In this case, the lift amount of the valve body 24, that is, the passage flow rate of the refrigerant can be adjusted by the rotation amount of the rotor 30, and the rotation amount of the rotor 30 is controlled by the number of supply pulses. (For details, refer to Patent Document 1 below).

  As an electric valve, as shown in Patent Document 2 below, a valve stem (shaft) provided with a male screw part, a valve body provided with a female screw part, and the valve body are prevented from rotating. And a valve body having a guide portion for reciprocally guiding the axial direction, the upper end of the valve stem is supported by a support provided on the top of the can, and the lower end of the valve stem is supported by the valve body. Also known is a structure in which the valve body portion is supported by a fixed bearing member and is configured not to rotate while allowing only the vertical movement.

JP 2008-169910 A JP 2000-346225 A

  In the electric valve 1 ′ described above, the rotor 30, the valve stem holder 32, and the upper stopper body 37 are integrally formed by screw feed between the fixing screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve stem holder 32. The valve stem holder 32 is controlled to move downward and upward while being rotated. The lower limit of the valve stem holder 32 is lowered (spiral motion) while the upper stopper body 37 integral with the valve stem holder 32 is rotated. It is made by contacting the upper part of the rear end surface of the lower stopper body 27 (contacting along the rotation direction). In this case, since the upper stopper body 37 descends by one pitch at one rotation, the bottom surface of the upper stopper body 37 often comes into contact with the upper surface of the lower stopper body 27 and becomes unable to further descend (valve rod). In some cases, malfunctions such as 25 locks). When such a malfunction occurs, the flow rate cannot be adjusted appropriately.

  The present invention has been made in view of such circumstances. The object of the present invention is to provide a low-cost and reliable operation that is less likely to cause malfunctions such as biting and locking while having a relatively simple configuration. It is to provide a motorized valve with high performance.

  In order to achieve the above object, the motor-operated valve according to the present invention basically includes a valve stem provided with a valve body at a lower end portion, and a valve body provided with a valve seat to which the valve body comes into contact with and separates from A cylindrical guide member having a lower end thereof fixed to the valve body, the valve stem being inserted therein, a can having a lower end sealed to the valve body, and an inner peripheral side of the can A rotor disposed in the rotor, a stator externally fitted to the can to rotationally drive the rotor, and a screw feed mechanism that moves the valve rod up and down using the rotation of the rotor. The guide member is rotatably supported, but the vertical movement is prevented, the rotor is provided with a fixed stopper, the valve stem is provided with a movement stopper, and the valve rod and the movement stopper are fixed with the rotor. While rotating integrally with the stopper, When the screw feed mechanism is screwed up and down by the feed mechanism, and the valve stem is moved to a predetermined position by the screw feed, the moving stopper is configured to be contacted and locked to the fixed stopper. It is a feature.

  The screw feed mechanism is preferably configured by a female screw portion formed on the inner periphery of the guide member and a male screw portion formed on the outer periphery of the valve rod.

  In a preferred embodiment, the valve stem includes a central threaded portion provided with the male threaded portion and a cylindrical portion with a ceiling connected to the lower side of the central threaded portion. The valve body is slidably inserted, and a valve closing spring that constantly urges the valve body downward is provided between the valve body and the ceiling of the cylindrical portion.

  In another preferred aspect, an insertion shaft portion having a non-circular cross section is provided above the central thread portion of the valve stem, and the insertion shaft portion is inserted into the fixed stopper so as to be slidable in the vertical direction. An insertion hole having a non-circular shape in plan view is formed.

  In another preferred aspect, the terrace surface formed between the central screw portion and the fitting shaft portion is an upper limit moving stopper that determines the rising limit position of the valve stem, and is located above the fitting shaft portion. Is provided with a lower limit moving stopper for determining the lower limit position of the valve stem.

  In a preferred aspect of the motor-operated valve according to the present invention, the rotor, the fixed stopper, the valve stem, the upper limit moving stopper, and the lower limit moving stopper are integrally rotated. The movement stopper does not rotate relative to the fixed stopper, and the upper limit movement stopper and the lower limit movement stopper come into contact with each other in the vertical direction to stop the movement of the valve stem (up and down movement while rotating). Therefore, compared with the case where the stopper is brought into contact with the rotation direction as in the conventional example, the malfunction such as biting / locking is less likely to occur while the structure is relatively simple. A highly reliable electric valve can be provided.

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 fully open state of one Embodiment of the motor operated valve which concerns on this invention. The expansion disassembled perspective view which shows the surroundings of the upper half part of the valve rod of the electrically operated valve shown by FIG. The longitudinal cross-sectional view which shows an example of the conventional motor operated valve.

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

  FIG. 1 and FIG. 2 are longitudinal sectional views showing a fully closed state and a fully opened state of an embodiment of a motor-operated valve according to the present invention. In the motor-operated valve 1 shown in FIGS. 1 and 2, portions corresponding to the respective portions of the motor-operated valve 1 'of the conventional example shown in FIG.

  The illustrated motor-operated valve 1 includes a valve rod 10 having a valve body 15 slidably provided at a lower end portion, a valve body 20 having a valve chamber 21 and a valve seat 22, and a lower end portion of the valve body 20. , The guide bush 60 whose lower end is press-fitted and fixed to the valve body 20, the rotor 30 disposed with a predetermined gap α on the inner periphery of the can 40, and the rotor 30. A stator 50 (not shown) externally fitted to the can 40 and a screw feed mechanism 11 (male thread portion) for making the valve body 15 contact and separate from the valve seat 22 by utilizing the rotation of the rotor 30. 11A and a female thread portion 11B), and the flow rate is controlled by changing the lift amount of the valve body 15 with respect to the valve seat 22.

  The guide bush 60 includes a cylindrical guide portion 61 in which a valve stem 10 (a cylindrical portion 10 d with a ceiling) is slidably inserted, and a female screw forming portion provided with a female screw portion 11 B constituting the screw feeding mechanism 11. The female thread forming portion 62 is composed of a large diameter portion 62a and a small diameter portion 62b having the same outer diameter as the cylindrical guide portion 61, and the upper end portion of the small diameter portion 62b is a caulking portion 63 (described later). Yes.

  The rotor 30 includes an outer peripheral cylindrical portion 30A, an inner peripheral cylindrical portion 30B, and a plurality of connecting portions 30C that connect them. The inner peripheral cylindrical portion 30B has an inner diameter smaller than the thin upper portion 30d and the thin upper portion 30d. It consists of a thick lower portion 30e. The thick lower portion 30e is placed on the large diameter portion 62a (on the terrace surface 62c) of the guide bush 60, and is loosely and rotatably fitted on the small diameter portion 62b. In addition, in order to allow rotation of the rotor 30 relative to the guide bush 60 but prevent its vertical movement (elevation), the upper end portion of the small diameter portion 62b is covered with the upper inner end surface portion 30f of the thick lower portion 30e. A stop caulking portion 63 is formed.

  In addition, a thick-walled stepped disc-like fixing stopper 17 is fitted into the upper end terrace portion of the inner peripheral cylindrical portion 30B and is fixed by welding or the like.

  On the other hand, the valve stem 10 includes a central screw portion 10c provided with a male screw portion 11A that is screwed into the female screw portion 11B of the guide bush 60, and a cylindrical portion 10d with a ceiling that is continuously provided below the central screw portion 10c. And a retaining collar 16 into which a valve body 15 with a hook-like part 15a is slidably fitted is fitted and fixed by welding or the like to the lower part of the cylindrical part 10d with a ceiling. A valve closing spring 14 that constantly biases the valve body 15 downward (in the valve closing direction) is mounted between the bowl-shaped portion 15a and the ceiling portion of the cylindrical portion 10d with ceiling.

  In addition, as shown in the exploded perspective view of FIG. 3 in addition to FIGS. 1 and 2, the cross section is non-circular (parallel chamfered racetrack shape) on the upper side of the central screw portion 10 c of the valve stem 10. An insertion shaft portion 10b is provided, and a racetrack-shaped insertion hole 17a in a plan view is formed in the center portion of the lid-like fixing stopper 17 so that the insertion shaft portion 10b is slidably inserted in the vertical direction. ing.

  Here, the step portion (step surface) between the central screw portion 10c and the insertion shaft portion 10b is used as an upper limit movement stopper 12 that determines the rising limit position of the valve rod 10, and the insertion shaft portion On the upper end surface of 10b, a small-diameter portion 10a for fixing is fixed, which is fitted with a lower limit moving stopper 13 that determines the lower limit position of the valve stem 10 and is fixed by welding or the like.

  When the fitting shaft portion 10b is fitted into the insertion hole 17a of the lid-like fixing stopper 17, the rotor 30, the lid-like fixing stopper 17, the valve stem 10 (the upper limit moving stopper 12), and the lower limit moving stopper 13 are formed. While rotating integrally, the rotor 30 is prevented from moving up and down (raising and lowering) by the terrace surface 62c of the guide bush 60 and the locking caulking portion 63, but the valve stem 10 is connected to the screw feed mechanism 11 (male thread portion 11A). And the female screw portion 11B) are screwed up and down (up and down). In this case, as shown in FIG. 1, in the valve stem 10, the position where the lower limit moving stopper 13 is contacted and locked to the upper surface of the lid-like fixed stopper 17 is the lower limit position, and as shown in FIG. The position at which the upper limit moving stopper (step surface) 12 is contacted and locked to the lower surface of the lid-like fixed stopper 17 is the ascending limit position.

  In the motor-operated valve 1 of the present embodiment configured as described above, when the rotor 30 is rotated in one direction, the valve stem 10 rotates integrally therewith and the valve stem 10 is rotated by the screw feed mechanism 11 (male thread portion 11A). And the female threaded portion 11B) are lowered with respect to the rotor 30 and the lid-like fixed stopper 17 that are prevented from moving up and down, the valve body 15 is pressed against the valve seat 22, and the valve port 22a is closed (fully closed state). .

  When the valve port 22a is closed, the lower limit moving stopper 13 is not yet in contact with the lid-like fixed stopper 17, and the valve rod 10 further rotates and descends while the valve body 15 closes the valve port 22a. In this case, since the valve stem 10 is lowered, the valve closing spring 14 is compressed by a predetermined amount. As a result, the valve body 15 is strongly pressed against the valve seat 22, and the valve rod 10 is rotated and lowered to move to the lower limit. The stopper 13 comes into contact with the lid-like fixed stopper 17 to prevent further lowering, and the rotation of the valve stem 10 is forcibly stopped (the state shown in FIG. 1).

  On the other hand, when the rotor 30 is rotated in the opposite direction, the valve stem 10 rotates integrally therewith, and the valve stem 10 is prevented from moving up and down by the screw feed mechanism 11 (the male screw portion 11A and the female screw portion 11B). The rotor 30 and the lid-like fixing stopper 17 are raised. In this case, since the valve closing spring 14 is compressed by a predetermined amount as described above at the time when the rotation of the valve rod 10 starts to be increased, the valve body 15 is not rotated until the valve closing spring 14 is extended by the predetermined amount. It does not leave the valve seat 22 and remains in a closed state (lift amount = 0). Then, after the valve closing spring 14 has been extended by the predetermined amount, when the valve stem 10 is further rotated up, the valve body 15 is separated from the valve seat 22 and the valve port 22a is opened.

  When the valve stem 10 is rotated up and the lift amount of the valve body 15 exceeds a predetermined amount, the valve rod 15 is fully opened. At this time, the upper limit moving stopper (step surface) 12 is brought into contact with the lower surface of the lid-like fixed stopper 17 to The above increase is prevented, and the rotation increase of the valve stem 10 is forcibly stopped (the state shown in FIG. 2).

  As described above, in the motor-operated valve 1 according to the present embodiment, the rotor 30, the lid-like fixed stopper 17, the valve stem 10 (the upper limit moving stopper 12), and the lower limit moving stopper 13 are integrally rotated to form a lid shape. The upper limit moving stopper 12 and the lower limit moving stopper 13 do not rotate relative to the fixed stopper 17, and the upper limit moving stopper 12 and the lower limit moving stopper 13 contact the lid-shaped fixed stopper 17 from the vertical direction. Since the valve stem 10 is configured to stop the movement of the valve stem 10, the operation such as biting / locking is performed as compared with the case where the stopper is brought into contact with the stopper in the rotational direction as in the conventional example, although the structure is relatively simple. As a result, it is possible to provide a motor-driven valve with low cost and high reliability.

  Note that the shape and configuration of each part of the motor-operated valve 1, for example, the rotor 30, the fixed stopper 17, the movement stoppers 12 and 13, and the insertion shaft part 10b are not limited to those of the above-described embodiment, but various It goes without saying that changes are possible.

DESCRIPTION OF SYMBOLS 1 Electric valve 10 Valve stick 11 Screw feed mechanism 11A Male thread part 11B Female thread part 12 Upper limit movement stopper 13 Lower limit movement stopper 14 Valve closing spring 15 Valve body 17 Lid-like fixed stopper 20 Valve body 21 Valve chamber 22 Valve seat 22a Valve port 30 Rotor 40 Can 50 Stator 60 Guide bush 63 Caulking portion for locking

Claims (5)

A valve stem provided with a valve body at the lower end, a valve main body provided with a valve seat for contacting and separating the valve body, a lower end thereof is fixed to the valve main body, and the valve stem is inserted. A cylindrical guide member, a can whose bottom end is hermetically joined to the valve body, a rotor disposed on the inner peripheral side of the can, and an outer fit to the can for rotationally driving the rotor A motor-driven valve comprising a stator and a screw feed mechanism that moves the valve stem up and down using the rotation of the rotor,
The rotor is rotatably supported by the guide member but is prevented from moving up and down, the rotor is provided with a fixed stopper, the valve stem is provided with a movement stopper, and the valve rod and the movement stopper are The rotor and the fixed stopper rotate integrally with each other, and are screwed up and down by the screw feed mechanism, and when the valve stem is moved to a predetermined position by the screw feed, the moving stopper contacts the fixed stopper. A motor-operated valve configured to be locked.   2. The motor-operated valve according to claim 1, wherein the screw feeding mechanism includes an internal thread portion formed on an inner periphery of the guide member and an external thread portion formed on an outer periphery of the valve rod. .   The valve stem includes a central threaded portion provided with the male threaded portion and a cylindrical portion with a ceiling connected to the lower side of the central threaded portion, and the valve body slides under the cylindrical portion with the ceiling. 2. A valve closing spring that is movably inserted and is urged downward at all times between the valve body and a ceiling portion of the cylindrical portion. Or the motor operated valve of 2.   A non-circular insertion in a plan view is provided in which an insertion shaft portion having a non-circular cross section is provided above the central thread portion of the valve stem, and the insertion shaft portion is slidably inserted into the fixed stopper in a vertical direction. The motor-operated valve according to claim 3, wherein a hole is formed.   A terrace surface formed between the central screw portion and the fitting shaft portion is an upper limit moving stopper that determines a rising limit position of the valve rod, and the valve rod is disposed above the fitting shaft portion. The motor-operated valve according to claim 3 or 4, further comprising a lower limit moving stopper for determining a lowering limit position.

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