JP2013122281A - Motor operated valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor operated valve capable of preventing a return spring from dropping out in the assembling of the motor operated valve, and increasing a degree of the design of the return spring and peripheral portions.SOLUTION: The motor operated valve 1 includes a valve body 4 having a valve chamber 2 and a valve hole 2a, a valve element 3a for opening and closing the valve hole, a valve shaft 3 having the valve element, a stator coil 18 disposed outside a can 12 projecting from the valve body, a rotor 6 rotating by the energized excitation of the stator coil, a thread pipe 7 fixed to the valve body, a valve shaft holder 8 formed rotatably with the rotor to open and close the valve hole by the valve element through the valve shaft by screw feeding action with the screw pipe, a push nut 10 to connect the valve shaft and the valve shaft holder, and a return spring 11 mounted to surround the push nut to energize the valve shaft holder in the screw returning direction when the screw pipe and the valve shaft holder are unscrewed. An end coil at the valve shaft holder side of the return spring is loosely fitted in an end at the valve shaft holder side of the push nut.

Description

  The present invention relates to a motor-operated valve used for refrigerant flow control in a refrigeration cycle system.

  As an example of the motor-operated valve, as shown in FIG. 4, a valve body 32 having a valve chamber 32 and a valve hole 32a formed in the valve chamber 32, and a valve body 33 for opening and closing the valve hole 32a are provided. There has been proposed an electric valve 31 that controls a fluid such as a refrigerant by driving a valve body 33 in the vertical direction by a drive mechanism 39 provided in a can 37 protruding upward from the main body 34 (for example, a patent) Reference 1). 4 shows a state where the valve hole 32a is closed by the valve body 33, and FIG. 6 shows a state where the valve hole 32a is opened.

  The valve mechanism 33 is driven by the drive mechanism 39 by a stepping motor including a rotor 36 provided inside the can 37 and a stator 38 fitted on the can 37. When the rotor 36 is rotated, the stop ring 40 and the valve shaft holder 41 are rotated accordingly, and the valve body 33 is moved up and down by a screw feeding action of the valve shaft holder 41 and the screw tube 42 fixed to the valve main body 34. The valve hole 32a is opened and closed.

  Here, when the valve shaft 43 rises and the screw tube 42 and the valve shaft holder 41 are disengaged when the valve is opened, the return spring is used to urge the valve shaft holder 41 toward the screw tube 42 to be screwed together. 45 is provided. As shown in FIG. 5, the return spring 45 is placed on the upper surface 41 a on the valve shaft holder 41 so as to surround the push nut 44 that connects the valve shaft 43 and the valve shaft holder 41. The return spring 45 is configured such that its inner diameter is larger than the outer diameter of the push nut 44.

JP 2001-50415 A

  However, in the conventional electric valve 31, the return spring 45 is merely placed on the upper surface 41a on the valve shaft holder 41, so that the return spring 45 may fall off the valve shaft holder 41 when the electric valve 31 is assembled. In such a case, since the return spring 45 is not properly attached to the motor-operated valve 31, the motor-operated valve 31 does not function normally.

  Further, in the conventional motor-operated valve 31, even when the return spring 45 is appropriately attached to the motor-operated valve 31 and assembled, the return spring 45 of the return spring 45 is prevented from being detached from the push nut 44 due to vibration during use. There is also a problem that the degree of freedom in design is reduced due to restrictions on the free length and the dimensions of the peripheral portion of the return spring 45.

  Therefore, the present invention has been made in view of the problems in the above-described conventional motor-operated valve, and prevents the return spring 45 from falling off during assembly of the motor-operated valve 31, and the design of the return spring 45 and its peripheral parts. It aims at providing the motor operated valve which can also raise the freedom degree of.

  In order to achieve the above object, the present invention provides an electric valve, a valve body having a valve chamber and a valve hole formed in the valve chamber, a valve body for opening and closing the valve hole, and the valve body at one end. A can that protrudes from the valve body, a stator coil that is disposed outside the can, a rotor that is disposed inside the can and is rotated by energization excitation of the stator coil, and the valve body A valve shaft holder that is formed to be rotatable together with the rotor, and that opens and closes the valve hole by the valve body via the valve shaft by a screw feeding action with the screw tube, and the valve A push nut that connects the end of the shaft opposite to the end having the valve body and the valve shaft holder, and is attached so as to surround the push nut, and the screw tube and the valve shaft holder When the screw is disengaged, the screw A return spring that urges the valve shaft holder in a direction to return the valve shaft holder, and the end portion of the return nut on the valve shaft holder side is loosely fitted to the end portion of the push nut on the valve shaft holder side It is characterized by that. Here, loose fitting means that the end portion of the return spring is fitted with play at the end of the push nut, that is, the end portion of the return spring can move to some extent in the axial direction of the push nut. In this state, it is attached to the end of the push nut.

  According to the present invention, since the end winding portion of the return spring on the valve shaft holder side is loosely fitted to the end portion of the push nut on the valve shaft holder side, it is possible to prevent the return spring from falling off during assembly of the electric valve. Can do. In addition, since the return spring does not come off the push nut due to vibration when the motorized valve is used, there are fewer restrictions on the free spring length and the dimensions of the surrounding area of the return spring, increasing the degree of design freedom. You can also.

  In the motor-operated valve, the end of the push nut on the valve shaft holder side is reduced in diameter, and the end winding portion of the return spring on the valve shaft holder side is smaller in diameter than the outer diameter of the push nut and the push The nut can be formed to have a larger diameter than the diameter-reduced end portion.

  In the motor-operated valve, both end portions of the push nut are reduced in diameter, and both end winding portions of the return spring are smaller in diameter than the outer diameter of the push nut and the reduced diameter end of the push nut. It can be formed larger in diameter than the part.

  Furthermore, in the motor-operated valve, the reduced diameter portion of the push nut can be formed in a tapered shape that is gradually reduced in diameter toward the open end of the push nut.

  As described above, according to the present invention, it is possible to prevent the return spring from falling off during assembly of the motor-operated valve, and to increase the degree of freedom in designing the return spring and its peripheral parts.

It is sectional drawing which shows one Embodiment of the motor operated valve which concerns on this invention, Comprising: The state in which the valve hole is closed is shown. FIG. 2 is an enlarged cross-sectional view showing a push nut, a return spring, and the vicinity thereof of the electric valve shown in FIG. 1. It is sectional drawing which shows the state in which the valve hole of the motor operated valve shown in FIG. 1 is opened. It is sectional drawing which shows an example of the conventional motor operated valve, Comprising: The state in which the valve hole is closed is shown. FIG. 5 is an enlarged cross-sectional view showing a push nut, a return spring, and the vicinity thereof of the electric valve of FIG. 4. It is sectional drawing which shows the state in which the valve hole of the motor operated valve shown in FIG. 4 is opened.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a motor-operated valve according to the present invention. The motor-operated valve 1 includes a valve body 4 having a valve chamber 2, and a valve body 3a for opening and closing a valve hole 2a communicating with the valve chamber 2. The valve shaft 3 having the valve body 3 a at the lower end, the can 12 protruding from the valve body 4, the stator coil 18 disposed outside the can 12, and rotating inside the can 12 by energization excitation of the stator coil 18 The rotor 6, the screw tube 7 fixed to the valve body 4, and the rotor 6 are formed so as to be rotatable, and the valve hole 2 a is opened and closed by the valve body 3 a through the valve shaft 3 by screw feeding action with the screw tube 7. A valve shaft holder 8 to be connected, a push nut 10 that connects the upper end portion of the valve shaft 3 and the valve shaft holder 8, and a screw nut 7 that is attached so as to surround the push nut 10. When the valve comes off, the valve shaft holder 8 is urged downward That consists of the return spring 11 and the like.

  Fluid inlet / outlet pipes 13 and 14 are connected to the side and lower parts of the valve body 4 so as to communicate with the valve chamber 2. A valve hole 2a is formed in the valve chamber 2 in the valve body 4, and the flow rate of the fluid is controlled by a gap between the valve hole 2a and the valve body 3a.

  The lower end of the lid-shaped cylindrical can 12 is butt welded to the stepped portion of the flange-like plate 16 fixed to the valve body 4 by caulking or welding, and the valve body 3a is driven in the vertical direction inside the can 12. A rotor 6, a screw tube 7, a valve shaft holder 8, a valve shaft 3, and the like are disposed.

  The rotor 6 is formed in a cylindrical shape and includes a retaining ring 17 that is integrally formed by insert molding. By this stop ring 17, the rotor 6 is configured to be rotatable together with the valve shaft holder 8.

  Further, the rotor 6 forms a stepping motor with a stator including the stator coil 18 disposed outside the can 12, and rotates by energizing the stator coil 18. A plurality of lead terminals 22 are connected to the stator coil 18, and a plurality of lead wires 24 are connected to these lead terminals 22 via a substrate 23.

  The valve shaft holder 8 is positioned outside the threaded tube 7 and is formed in a cylindrical shape that opens downward. A female threaded portion 8a that is screwed with the male threaded portion 7a of the threaded tube 7 is screwed on the inner peripheral surface thereof. . The upper stopper body 15 is fixed to the lower part of the valve shaft holder 8 so as to be able to contact the lower stopper body 5 fixed to the screw tube 7.

  The valve shaft 3 is integrally provided with a valve body 3a at a lower end portion thereof, and is inserted into the center of the valve shaft holder 8 so as to be vertically movable. The valve shaft 3 is always urged downward by a valve closing spring 9 that is mounted in the valve shaft holder 8.

  The threaded tube 7 has a male threaded portion 7a threaded on the outer peripheral surface thereof, and a lower stopper body 5 constituting one of the stopper mechanisms is fixed thereto. As described above, the lower stopper body 5 is configured to be able to come into contact with the upper stopper body 15 located below the valve shaft holder 8.

  At the upper end of the valve shaft 3, there is a push nut 10 that connects the valve shaft 3 and the valve shaft holder 8, and the valve shaft 3 moves too much upward during the valve opening operation so that the male threaded portion 7a of the screw tube 7 and the valve shaft A return spring 11 is provided to bias the valve shaft holder 8 toward the screw tube 7 when the holder 8 is disengaged from the female threaded portion 8a.

  As shown in FIG. 2, the upper and lower ends of the push nut 10 are tapered (tapered portion 10a) so that the cross section is inclined and the end portion is reduced in diameter.

  Further, the inner diameter of the effective winding portion of the return spring 11 (the portion other than the both end winding portions 11a of the return spring 11) is the outer diameter of the central portion of the push nut 10 (the portion of the push nut 10 other than the tapered portion 10a). It is formed in a larger diameter than. The inner diameter of the upper and lower ends (both ends) of the return spring 11 is larger than the minimum outer diameter of the taper portion 10a (that is, the outer diameter of both ends of the push nut 10) and the center of the push nut 10 It is formed smaller than the outer diameter of the part.

  The point configured in this way is a characteristic part of one embodiment of the present invention, and by pushing the return spring 11 into the push nut 10 with a slight force, the end winding portion 11a below the return spring 11 is The push nut 10 is loosely fitted into the tapered portion 10a below. As a result, it is possible to prevent the return spring 11 from falling off when the electric valve 1 is assembled. In addition, this can prevent the return spring 11 from falling off due to vibration during use, thereby reducing restrictions on the free length of the return spring 11 and the dimensions of the peripheral portion of the return spring 11 and increasing the degree of design freedom. It can also be increased. Furthermore, since the taper part 10a was formed in the both ends of the push nut 10, and the end winding part 11a of the both ends of the return spring 11 was diameter-reduced, the motor operated valve 1 can be assembled without considering these up-down directions.

  In the motor-operated valve 1 having the above configuration, as shown in FIG. 1, when the stator coil 18 is energized in one direction through the lead wire 24, the substrate 23 and the lead terminal 22, the rotor 6 rotates. Accordingly, the valve shaft holder 8 rotates relative to the screw tube 7. Here, since the lower part of the screw tube 7 is fixed to the valve body 4, for example, the valve shaft holder 8 is moved by the screw feed mechanism of the male screw portion 7 a of the screw tube 7 and the female screw portion 8 a of the valve shaft holder 8. As a result, the valve shaft 3 rises, and the valve body 3a opens the valve hole 2a, resulting in the state shown in FIG.

  Even if the valve shaft holder 8 is further raised and the internal thread portion 8a of the valve shaft holder 8 and the external thread portion 7a of the screw tube 7 are unscrewed, the upper end of the return spring 11 is elastically contacted with the upper inner wall portion of the can 12. By urging the valve shaft holder 8 toward the lower screw tube 7, the screwing of the female screw portion 8a and the male screw portion 7a can be reliably returned.

  When the stator coil 18 is energized in the other direction from the state shown in FIG. 3, the rotor 6 rotates relative to the screw tube 7 fixed to the valve body 4 in the opposite direction to the screw feed. Due to the mechanism, the valve shaft holder 8 is lowered, the valve body 3a at the lower end of the valve shaft 3 is moved downward to close the valve hole 2a, and the state shown in FIG. Further, the upper stopper body 15 located at the lower part of the valve shaft holder 8 and the lower stopper body 5 come into contact with each other, thereby preventing the valve body 3a from further descending.

  In the above embodiment, tapered portions 10a are formed at both ends of the push nut 10, the end winding portions 11a at both ends of the return spring 11 are reduced in diameter, and the vertical direction of the push nut 10 and the return spring 11 is taken into consideration. Although the motor-operated valve 1 can be assembled without the need, the tapered portion 10a is formed only at one end of the push nut 10, and the diameter of only the end winding portion 11a of the return spring 11 is reduced to assemble the motor-operated valve 1. In addition, the taper portion 10a is disposed at the lower end of the push nut 10, and the end turn portion 11a of the return spring 11 is loosely fitted to the taper portion 10a, thereby preventing the return spring 11 from dropping off during assembly. The degree of freedom in designing the return spring 11 and its peripheral parts can be increased.

  In the above description, as shown in FIG. 2, the tapered portion 10a is formed so that the cross section is linear, but the present invention is not limited to this, and the pusher 10a is pushed. The tapered portion 10a is not formed at the end of the nut 10, but a concave reduced diameter portion is formed so as to provide a step, or the cross section is formed in an arc shape or the like, and the return spring 11 is formed in this portion. The same effect can be obtained even if the end turn part 11a having a reduced diameter is loosely fitted.

  Furthermore, in the above description, the end winding part 11a at both ends of the return spring 11 is reduced in diameter, but the end winding part 11a and the effective winding part adjacent thereto are continuously reduced in diameter. May be.

DESCRIPTION OF SYMBOLS 1 Motorized valve 2 Valve chamber 2a Valve hole 3 Valve shaft 3a Valve body 4 Valve body 5 Lower stopper body 6 Rotor 7 Screw pipe 7a Male thread part 8 Valve shaft holder 8a Female thread part 9 Valve closing spring 10 Push nut 10a Taper part 11 Return spring 11a End winding part 12 Can 13 Outflow pipe 14 Inflow pipe 15 Upper stopper body 16 Gutter-shaped plate 17 Stop ring 18 Stator coil 22 Lead terminal 23 Substrate 24 Lead wire

Claims (4)

A valve body having a valve chamber and a valve hole formed in the valve chamber;
A valve body for opening and closing the valve hole;
A valve stem having the valve body at one end;
A can protruding from the valve body;
A stator coil disposed outside the can;
A rotor disposed inside the can and rotated by energization excitation of the stator coil;
A threaded tube fixed to the valve body;
A valve shaft holder that is formed so as to be rotatable together with the rotor, and that opens and closes the valve hole by the valve body via the valve shaft by a screw feeding action with the screw pipe;
A push nut connecting the end of the valve shaft opposite to the end having the valve body and the valve shaft holder;
A return spring mounted so as to surround the push nut and energizing the valve shaft holder in a direction to return the screw shaft when the screw tube and the valve shaft holder are unscrewed. ,
The motor-operated valve characterized in that the end winding portion on the valve shaft holder side of the return spring is loosely fitted to the end portion of the push nut on the valve shaft holder side. The end of the push nut on the valve shaft holder side is reduced in diameter,
The end winding portion of the return spring on the valve shaft holder side is formed to have a smaller diameter than an outer diameter of the push nut and a larger diameter than the reduced diameter end portion of the push nut. The motor-operated valve according to Item 1. Both ends of the push nut are reduced in diameter,
3. The return spring according to claim 2, wherein both end winding portions have a smaller diameter than an outer diameter of the push nut and a larger diameter than the reduced diameter end portion of the push nut. The motorized valve described.   4. The motor-operated valve according to claim 2, wherein the reduced diameter portion of the push nut is formed in a tapered shape that is gradually reduced in diameter toward the open end of the push nut.

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