JP5380562B2 - Motorized valve - Google Patents

Description

  The present invention relates to a motor-operated valve used to control the flow rate of refrigerant in an air conditioner, for example.

  Conventionally, an electric valve that is incorporated and used in an air conditioner, a refrigerator, or the like of this type has a function of adjusting a flow rate of a fluid such as a refrigerant, and usually includes a valve body having a valve chamber and a valve seat. And a bottomed cylindrical can fixed to the upper part of the valve body, a rotor is built inside the can, and a stator having an insertion hole in the center is externally fitted to the outside of the can. .

  FIG. 5 shows a longitudinal sectional view of a known motor-operated valve 100. The motor-operated valve 100 includes a valve body 120 that adjusts the flow rate of refrigerant through a valve body 123 that is separated from and connected to the valve seat 122 in the valve chamber 121, and a rotor 130 that is fixed to the valve body 120 and separates the valve body 123. A built-in can 140 and a stator 143 that is externally fitted to the can 140 and rotationally drives the rotor 130 are provided. The rotor 130 and the stator 143 constitute a stepping motor. In addition, refrigerant inflow / outflow pipes 120 a and 120 b are connected to and connected to the valve chamber 121 at the lower part and the side part of the valve body 120.

  A valve chamber 121 is formed in the valve main body 120, a valve seat 122 is formed below the valve chamber 121, a guide bush 126 is fixed above, and an annular groove is formed between the guide bush 126. The joining with the can 140 is performed by butt welding the end of the can 140 to the stepped portion of the flanged plate 141 that is caulked and fixed to the valve body 120.

  The can 140 has a bottomed cylindrical shape, and is fixed to a bowl-shaped plate 141 fixed to the upper part of the valve body 120, and the inside is kept airtight. The stator 143 includes a yoke 151 made of a magnetic material, and upper and lower stator coils 153 and 153 wound around the yoke 151 via one bobbin 52, and a fitting hole 144 a that fits outside the can 140 is formed. Is formed. A plurality of lead terminals 154 connected to the stator coils 153 and 153 protrude from the stator 143, a connector 156 is connected to the lead terminal 154, and a plurality of lead wires 155 are connected to the connector 156.

  A valve body 123 formed of a needle valve is formed at the lower end of the valve shaft 124. A drive mechanism for separating the valve body 123 from the valve seat 122 includes a cylindrical guide bush 126 extending from the valve body 120 toward the rotor 130 and fixed to form a fixing screw portion 125, and fixing the guide bush 126. The valve shaft holder 132 includes a moving screw portion 131 that is screwed into the screw portion 125.

  The fixed screw portion 125 is formed of a male screw on the outer periphery of the guide bush 126, and the moving screw portion 131 is formed on the inner periphery of the valve shaft holder 132 as a female screw.

  The valve shaft holder 132 has a cylindrical shape with a lower opening located outside the guide bush 126, a moving screw portion 131 is formed on the inner surface, and an upper diameter-reduced portion of the valve shaft 124 is fitted in the center of the valve shaft holder 132. Are connected by a push nut 133. A valve shaft 124 having a valve body 123 formed at the lower end thereof is fitted into the center of the valve shaft holder 132 so as to be movable up and down, and is always lowered downward by a compression coil spring 134 fitted in the valve shaft holder 132. It is energized.

  The valve shaft holder 132 and the rotor 130 are coupled via a support ring 136. The upper protrusion of the valve shaft holder 132 is fitted into the inner peripheral hole of the support ring 136, and the outer periphery of the protrusion is fixed by caulking. The rotor 130, the support ring 136, and the valve shaft holder 132 are connected.

  A lower stopper body 127 constituting one of the stopper mechanisms is fixed to the guide bush 126, and a plate-like lower stopper piece 127a is projected above the lower stopper body 127. Further, an upper stopper body 137 constituting the other of the stopper mechanism is fixed to the valve shaft holder 132, and a plate-like upper stopper piece 137a protrudes downward and can be engaged with the lower stopper piece 127a.

  The lower stopper body 127 is fixed to a spiral groove portion 126 a formed on the outer periphery of the guide bush 126, and the upper stopper body 137 is fixed to a spiral groove portion 132 b formed on the outer periphery of the valve shaft holder 132. Further, a pressure equalizing hole 126b is provided on the side surface of the guide bush 126 directly below the fixing screw portion 125 for the purpose of equalizing the pressure in the valve chamber 121 and the space in the can 140, and the refrigerant is passed through the pressure equalizing hole 126b. It is configured to facilitate the distribution of

  In the above structure, when the space between the inside of the can 140 and the valve chamber 121 is sealed to prevent a fluid such as a refrigerant passing through the valve chamber 121 from entering the inside of the can 140, the pressure between the two can be reduced. As a result, a load is applied to the fixing screw portion 125 and the moving screw portion 131 in the vertical direction, and the screw operating portion may be locked. In order to reduce the pressure difference between the inside of the can 140 and the valve chamber 121, for example, one or two equalizing holes for allowing pressure to pass between the valve shaft 124 and the guide bush 126 are formed. Has been proposed (see Patent Document 1). However, if the pressure equalizing hole 126b is formed, foreign matter in the fluid flowing through the valve chamber 121 may enter the can 140 through the pressure equalizing hole 126b. In particular, when the installation period of the installation work is long, such as a multi air conditioner for a building, if the sealing port of the refrigerant pipe is insufficiently sealed, foreign matters such as sludge easily enter the pipe. When the air conditioner is operated after the installation work is completed, if foreign matter enters the refrigerant flow and enters the can 140 of the motor-operated valve 100, the foreign matter may adhere to the screw operating portion and hinder smooth screw operation. . In Patent Document 1, a distance is formed between the screw threaded portion (fixed screw portion 125 and moving screw portion 131) and the formation position of the pressure equalizing hole 126b, and foreign matter such as sludge adheres to the screw threaded portion. Although prevention is aimed at, it is hard to say that the above-mentioned problems can be surely prevented.

JP 2003-172467 A

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to reliably prevent foreign matters contained in the fluid from entering the can and hindering the operation of the rotor or the speed reduction mechanism. It is to provide a motorized valve that can.

In order to solve the above-mentioned problems, an electric valve according to the present invention is provided with a valve body having a valve chamber and a valve seat formed therein, and a valve shaft provided at the tip of the valve shaft. A valve body that adjusts the flow rate; a drive unit that includes a rotor and a stator that rotationally drives the rotor; a feed screw mechanism that converts rotation of the rotor into contact and separation of the valve body with respect to the valve seat; and the valve body A foreign object intrusion prevention device comprising: a can attached to the housing for accommodating the rotor; and a refrigerant passage communicating the valve chamber and the inside of the can; and preventing foreign matter from entering the can through the refrigerant passage. An electric valve provided with a member, which is wound around the valve body to remove backlash inherent in the feed screw mechanism, and moves the valve body away from the valve seat. An urging spring member; I and a spring cover member that covers the outer member, the foreign matter intrusion preventing member from said one end of the spring cover member extending in the axial direction of the valve shaft, the valve shaft guide to Rutotomoni said at its inner peripheral surface It is an extension guide part that forms a minute gap with the surface of the valve shaft .

  According to this electric valve, since the foreign matter intrusion preventing member for preventing foreign matter from entering the can through the refrigerant passage communicating with the valve chamber and the inside of the can is disposed, the foreign matter contained in the refrigerant is Even if the gas flows through the can, the foreign matter intrusion prevention member prevents the intrusion into the can, and can reliably prevent the operation of the motor-operated valve.

It is sectional drawing which shows the example of a motor operated valve. It is a fragmentary sectional view showing another example of an electric valve. It is sectional drawing which shows the Example of the motor operated valve of this invention. It is sectional drawing which shows the other example of a motor operated valve. It is sectional drawing which shows an example of the conventional motor operated valve.

  FIG. 1 is a cross-sectional view showing the entire structure of the motor-operated valve. The motor-operated valve denoted by reference numeral 1 as a whole operates with an excitation function and includes a drive unit 1a having a motor composed of a stator and a rotor, and a rotational drive force from the drive unit 1a is input to reduce gears and output a reduced rotation. The gear reducer unit 1b, the feed screw mechanism unit 1c that converts the reduced rotation from the gear reducer unit 1b into a displacement in the screw shaft direction by a screw action, and the fluid flow path by the operation of the screw mechanism unit 1c. And a valve main body 1d for opening and closing.

  Reference numeral 30 denotes a top cylindrical can which is an airtight container fixed to the valve body 10 via a receiving member 68. The drive unit 1a is disposed on the outer periphery of the can 30 and is wound around a bobbin. The motor excitation device 2 in which the coil 3 constituting the stator of the electric motor is molded integrally with the resin, and the permanent magnet type that is rotatably supported in the can 30 and is driven to rotate by the motor excitation device 2 And a rotor assembly 8. The motor excitation device 2 and the rotor assembly 8 constitute a stepping motor as an example of an electric motor.

  The motor excitation device 2 is detachably fitted to the can 30 by a fixture 5 formed by a leaf spring. In this example, the convex portion 6 formed on the can 30 is elastically fitted and positioned in the engagement hole 7 formed on the fixture 5. In the motor exciter 2, the coil 3 is connected to an external power source via the connector 4 and leads to receive power supply in order to excite the stator. The valve body 10 has a valve chamber 14 formed therein, and a bottom portion 15 formed with an orifice 16 that opens to the bottom surface of the valve body 10. A pipe 22 communicating with the side surface of the valve chamber 14 and a pipe 20 communicating with the lower end of the orifice 16 are fixed to the valve body 10.

  The gear reducer portion 1 b includes a planetary gear type reduction mechanism (hereinafter abbreviated as “deceleration mechanism”) 40 that reduces the rotation of the rotor assembly 8. The speed reduction mechanism 40 is supported by a sun gear 41 integral with the rotor assembly 8, a plurality of planetary gears 43 rotatably supported by the carrier 42 and meshed with the sun gear 41, and fixedly supported by the valve body 10 via a gear case 39. A ring gear 44 that meshes with a part of the planetary gear 43 and an output internal gear 45 that has a slightly different number of teeth from the ring gear 44 are provided. The rotation of the rotor assembly 8 decelerated by the reduction mechanism 40 is transmitted to the output shaft 46 of the feed screw mechanism 1c via the output internal gear 45. In this example, a planetary gear type reduction mechanism is provided as the reduction mechanism 40, but a gear train mechanism arranged in series in place of the planetary gear type reduction mechanism may be used. Alternatively, the speed reduction mechanism 40 is not necessarily required, and the rotation of the rotor may be directly input to the screw mechanism. In addition, a bearing 48 formed by metal plate processing is fitted and attached to the upper portion of the can 30 to rotatably support the shaft 47 of the speed reduction mechanism 40, and the rotor assembly 8, the ring gear 44, and the like. A disc spring 49 for biasing the rotor assembly 8 toward the bearing 48 is disposed therebetween.

  The feed screw mechanism portion 1c performs a linear motion that causes the valve body 61 of the valve shaft 60 to contact and separate from the valve seat 62 by rotating the rotor assembly 8 transmitted to the output shaft 46 via the planetary gear type reduction mechanism 40. Convert. The feed screw mechanism portion 1c is supported by the valve body 10 and rotatably supports the output shaft 46 on the upper side, and a cylindrical bearing 50 in which a female thread portion 51 is formed on the lower inner periphery, and a cylindrical bearing And a threaded shaft 52 formed with a threaded portion 53 to be engaged with the threaded portion 51 of 50. The cylindrical bearing 50 is fixedly supported in a state of being fitted into an upper portion of a valve hole 63 formed in the valve body 10. That is, the cylindrical bearing 50 is a fixed screw portion, and the screw shaft 52 is a moving screw portion. The convex portion 54 formed at the lower end of the output shaft 46 is engaged with a concave portion 55 formed at the upper end of the screw shaft 52, and transmits the rotation of the output shaft 46 to the screw shaft 52. The upper end of the output shaft 46 is connected and fixed to the rotating shaft of the rotor assembly 8.

  The axial displacement of the screw shaft 52 is transmitted to the valve shaft 60 via the ball 65 and the ball receiving member 66. When the screw shaft 52 is moved in the valve opening direction in the feed screw mechanism 1c, the valve body 60 is urged in the valve opening direction to remove the backlash between the female screw portion 51 and the male screw portion 53. A coil spring 70 is provided.

  In order to support the coil spring 70, a metal bottomed cylindrical spring receiver 73 (a spring covering member) is disposed in the valve chamber 14. The spring receiver 73 includes a cylindrical peripheral wall 74 that covers the outer peripheral surface of the valve shaft 60 except for the lower end portion thereof, an outward flange portion 75 that is formed outwardly at the upper end thereof, and a lower end of the peripheral wall 74. And an inward flange portion 76 formed in such a manner as to leave a hole 77 through which the valve shaft 60 can be penetrated. The coil spring 70 is supported in a compressed state by having an upper end 71 abutting against the large diameter portion 67 of the valve shaft 60 and a lower end 72 abutting against the inward flange portion 76 of the spring receiver 73. Yes. The outward flange portion 75 of the peripheral wall 74 is sandwiched between the stepped portion 64 formed at the lower end of the valve hole 63 of the valve body 10 and the lower end portion of the cylindrical bearing 50 attached to the valve hole 63. It is fixed.

  The valve shaft 60 is always urged in the valve opening direction (in the direction of the screw mechanism portion 1c) by the spring force of the coil spring 70 held in a compressed state by the spring receiver 73, and the valve shaft is driven by the force from the feed screw mechanism 1c. When the valve 60 is pushed down in the valve closing direction, the valve shaft 60 is lowered against the spring force of the coil spring 70, and the valve body 61 formed at the tip of the valve shaft 60 is seated on the valve seat 62 so that the orifice 16 is moved. close up. Since the position of the valve shaft 60 with respect to the valve seat 62 can be positioned with high resolution by the gear reduction unit 1b, the flow passage area between the valve body 61 and the orifice 16 is controlled with high accuracy, and the flow rate of refrigerant passing therethrough is controlled with high accuracy. Can be adjusted. When the feed screw mechanism 1 c is operated in the valve opening direction, the valve shaft 60 moves following the rise of the screw shaft 52 by the spring force of the coil spring 70.

  Since the coil spring 70 urges the feed screw mechanism 1c in the valve opening direction by the spring force, the play existing between the female thread portion 51 of the cylindrical bearing 50 and the male thread portion 53 of the screw shaft 52 is The screw shaft 52 is absorbed by being moved upward with respect to the cylindrical bearing 50. When the valve body 61 is closed, the reaction force is immediately transmitted from the male threaded portion 53 to the female threaded portion 51 without going through an invalid stroke for absorbing screw play when the valve body 61 comes into contact with the valve seat 62. Further, when the valve is opened, the male threaded portion 53 moves following the female threaded portion 51 when the valve body 61 is separated from the valve seat 62. In the present embodiment, by providing the coil spring 70 in the valve chamber 14, the vertical dimension of the motor-operated valve can be made smaller than when the coil spring is provided above the valve chamber 14.

  In the example shown in FIG. 1, the outer peripheral surface of the bearing tube portion 50 constituting the feed screw mechanism portion 1 c is fitted to the inner peripheral surface of the upper tube portion of the valve body 10. An annular groove 81 and a vertical hole 90 communicating with the annular groove 81 are formed in the bearing tube portion 50. A pressure equalizing hole 80 is formed in the upper cylindrical portion of the valve body 10 so as to penetrate in the radial direction. The inner opening of the pressure equalizing hole 80 faces the annular groove 81 and the vertical hole 90 of the bearing tube portion 50, and the outer opening is opened in the internal space of the can 30. Therefore, the annular groove 81, the vertical hole 90, and the pressure equalizing hole 80 described above form part of a fluid passage that allows the refrigerant to pass through the valve chamber 14 side and the inside of the can 30. In the conventional electric valve, a bellows is attached to the outside of the valve shaft 60 to prevent the refrigerant introduced into the valve chamber 14 from entering the can 30, and the fluid pressure acting on the bellows or the bellows itself. There is a type in which an upward biasing force is applied to the valve shaft 60 by the elastic force of the above. In this embodiment, an expensive bellows that requires a process such as welding is not used, and the refrigerant can enter the can 30 through the pressure equalizing hole 80. As a result, the load due to the pressure difference does not act on the screw operating portion between the cylindrical bearing 50 and the screw shaft 52, and the screw operating portion is not locked.

  In this example, an annular groove 81 is formed on the outer peripheral surface of the cylindrical bearing 50 including the position where the opening of the pressure equalizing hole 80 faces. The annular groove 81 is provided with a ring-shaped foreign matter intrusion preventing member 82 fitted therein. In order to fulfill the function of preventing the entry of foreign matter, the foreign matter intrusion prevention member 82 may be disposed only at the position where the opening of the pressure equalizing hole 80 faces. However, by configuring the foreign matter intrusion prevention member 82 in a ring shape, the valve body 10 and the cylindrical bearing 50 are fitted at any angular position, the foreign matter intrusion prevention member 82 exists at the position where the opening of the pressure equalizing hole 80 faces, thereby reducing the alignment work load at the time of assembly. It is done.

  The foreign matter intrusion prevention member 82 is preferably a fluid-permeable porous body such as foam metal. By making the foreign matter intrusion preventing member 82 such a porous body, the refrigerant can pass through, but since the foreign matter is captured by its filter action, it does not flow into the can 30. Moreover, a filter such as a wire mesh may be used as long as it has a filter function of capturing foreign matters while having such fluid passage properties.

  Another example of a motorized valve is shown in FIG. In the motor operated valve 1 </ b> A shown in FIG. 2, a foreign matter intrusion preventing member 83 is disposed in the pressure equalizing hole 80. The foreign matter intrusion preventing member 83 is formed into a cylindrical shape from a material such as foam metal similar to the previous example, and is inserted into the pressure equalizing hole 80. Since the other components are the same as those in the embodiment shown in FIG. 1, the same reference numerals are used and the description thereof is omitted.

  An embodiment of the motorized valve of the present invention is shown in FIG. Also in the motor operated valve 1B shown in FIG. 3, the same reference numerals are given to the same components and parts as those in the example shown in FIG. In the motor-operated valve 1B, the spring receiver (spring covering member) 73b includes a guide tube portion 78 as an extension guide portion extending from the lower flange portion 76 along the valve shaft 60 toward the valve body 61. The guide tube portion 78 has a length sufficient to guide the valve shaft 60 in the axial direction, and a gap formed between the outer peripheral surface of the valve shaft 60 and the inner peripheral surface of the guide tube portion 78. However, it forms part of the fluid passage through which the refrigerant flows from the valve chamber 14 into the can 30. The fluid passage formed by this narrow gap makes it difficult for foreign matter that can be contained in the refrigerant to pass through, and functions as a foreign matter intrusion prevention member that prevents foreign matter from entering the feed screw mechanism 1c and the can. . The guide cylinder portion 78 also improves the axial guideability of the valve shaft 60 and improves the seating property (concentricity) of the valve body 61 with respect to the valve seat 62.

  FIG. 4 shows another example of the electric valve. In the motor-operated valve 1C shown in FIG. 4 as well, parts and parts equivalent to those in the embodiment shown in FIG. In the motor-operated valve 1C, the spring receiver (spring covering member) 73c includes an extension cylinder portion 85 as an extension portion extending from the lower throttle portion 84 along the valve shaft 60 toward the valve body 61. The lowermost end of the cylindrical portion 85 is formed in an inner flange portion 86 bent toward the outer peripheral surface side. A gap 87 that allows movement of the valve shaft 60 and passage of the refrigerant is formed between the inner flange portion 86 and the valve shaft 60. The diameter of the cylindrical inner surface of the extension cylinder portion 85 is larger than the outer diameter of the valve shaft 60. Therefore, an annular space 88 is formed between the two. A cylindrical foreign material capturing member 89 capable of capturing foreign materials that can be contained in the refrigerant is mounted in the annular space 88. The foreign matter catching member 89 is supported by the inner flange portion 86 and does not fall off from the annular space 88. The foreign material capturing member 87 is formed of a foam metal as in the embodiment described above. However, other materials can be used as long as they have fluid permeability and foreign material capturing properties. The foreign matter catching member 87 disposed in the extension cylinder portion 85 also has a function of improving the guide performance of the valve shaft 60, and improves the seatability of the valve body 61 with respect to the valve seat 62. The present invention is not limited to the above-described embodiments, and various modifications can be made to the above-described embodiments without departing from the gist of the present invention.

1, 1A, 1B, 1C Motorized valve 1a Drive unit 1b Gear reducer unit 1c Feed screw mechanism 1d Valve body 2 Motor excitation device 3 Coil 8 Rotor assembly 10 Valve body 14 Valve chamber 16 Orifice 20, 22 Piping 30 Can 39 Gear case 40 Planetary gear type reduction mechanism 41 Sun gear 42 Carrier 43 Planetary gear 44 Ring gear 45 Output internal gear 46 Output shaft 47 Shaft 48 Bearing 49 Belleville spring 50 Cylindrical bearing 51 Female thread portion 52 Screw shaft 53 Male thread portion 60 Valve shaft 61 Valve body 62 Valve seat 63 Valve hole 65 Ball 66 Ball receiving member 70 Coil spring 73, 73b, 73c Spring receiver (cover member)
78 Guide tube (extension guide)
80 Pressure equalizing hole 81 Annular groove 82, 83 Foreign matter intrusion preventing member 85 Extension cylinder (extension)
88 Annular space 89 Foreign material capture member

Claims (2)

A valve body having a valve chamber and a valve seat formed therein, a valve body provided at the tip of the valve shaft for adjusting the flow rate of fluid passing through the valve seat, and rotating the rotor and the rotor A drive unit having a stator that performs rotation, a feed screw mechanism that converts the rotation of the rotor into contact / separation operation with respect to the valve seat, a can that is attached to the valve body and accommodates the rotor, And a refrigerant passage communicating with the inside of the can, and an electric valve provided with a foreign matter intrusion preventing member that prevents foreign matter from entering the can through the refrigerant passage,
A spring member wound around the valve body to remove backlash inherent in the feed screw mechanism and biasing the valve body in a direction away from the valve seat; and A spring covering member covering the outside,
The foreign material intrusion prevention member, forming a small gap between the spring cover extending from one end of the member in the axial direction of the valve shaft, of which guides the valve shaft in the circumferential surface to Rutotomoni surface of the valve shaft An electrically operated valve characterized by being an extended guide portion.   In order to decelerate and transmit the rotation of the rotor to the feed screw mechanism, a gear speed reducer unit including a gear train mechanism or a planetary gear mechanism that transmits and connects the rotor and the feed screw mechanism is provided. The motor-operated valve according to claim 1.

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