JP2008267464A - Motor driven valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor driven valve wherein a can into which a high refrigerant pressure in a valve chest is applied has an improved pressure resistance. <P>SOLUTION: The motor driven valve 1 comprises a valve body 10 having the valve chest and a valve seat 62 formed therein, a valve element 61 for contacting/leaving the valve seat 62 to adjust the passing flow amount of fluid, the cylindrical can 30 fixed to the valve body 10 and communicated with the valve chest 12, a motor exciting stator 2 mounted on the outer periphery of the can 30, a rotor assembly 8 to be rotationally driven by the stator 2 in the state of being rotatably supported on the inner periphery of the can 30, and a feed screw mechanism 1c for converting the rotation of the rotor assembly 8 into the contacting/leaving operation of the valve element 61 on the valve seat 62. A top portion of the can 30 is formed in a domed shape, and a supporting member 300 is provided separately from the can 30 for supporting the rotating shaft of the rotor assembly 30 at its end on the top portion side of the can 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  The so-called electric valves that open and close the valve via an electric motor are roughly classified into the following two types. The first type is one in which the rotation of the rotor is directly transmitted to the screw mechanism to open and close the valve, and is disclosed in Patent Document 1, for example. The second type includes a reduction device that reduces the rotation of the rotor with a reduction device and transmits the rotation to the screw mechanism, and is disclosed in, for example, Patent Literature 2 and Patent Literature 3.

  In FIG. 12, as one form of an existing motorized valve, a motorized valve adopting a bellows that decelerates the rotation of a motor by a speed reducer such as a planetary gear mechanism and forms a partition wall for the refrigerant (see Patent Document 2). ) Is shown as a cross-sectional view.

  The motor-operated valve shown in FIG. 12 includes a valve body 10 having a valve seat 12 and a valve chamber 14. Two pipes 20, 22 communicating with the valve chamber 14 are attached to the valve body 10. A valve rod 32 is connected to the valve body 30. The ring member 38 placed in the upper opening of the valve body 10 is fixed to the valve body 10 by, for example, a crimped portion K1 or soldering. A bellows 48 is provided between the ring member 38 and the valve stem 32 to seal the intrusion of the refrigerant. A receiving member 34 of a ball 36 is inserted and fixed to the upper end portion of the valve rod 32. A screw shaft 52 is brought into contact with the upper portion of the ball 36, and axial thrust is transmitted to the valve stem 32 side by a screw mechanism.

  A flange member 70 constituting a part of the valve main body is fixed to the outer peripheral portion of the upper end of the valve main body 10 by means of welding or the like, thereby blocking the outside air and preventing intrusion of gas, moisture and the like. A receiving member 80 is fixed to the upper portion of the flange member 70. A cylindrical member 82 is attached to the outer peripheral side of the receiving member 80, and a female screw member 90 is attached to the inner peripheral side of the receiving member 80. A cylindrical can 100 made of a nonmagnetic metal material is fixed to the upper portion of the flange member 70 by welding or the like. An excitation device M for a stepping motor as an example of a drive motor is attached to the outside of the can 100.

  The exciter M includes a resin mold 120, a coil 140 wound around a bobbin 130 provided therein, and a stator 2 that is excited by energization of the coil. The coil 140 is supplied with power via a lead 142. The The exciter M is detachably attached to the can 100 by engaging the hole 182 of the mounting bracket 180 provided in the lower part of the exciter M with the protrusion 102 formed in the can 100. A cylindrical protrusion 104 is formed on the top of the can 100, and a support member 150 that supports the fixed shaft 152 is press-fitted and fixed inside the protrusion 104. Inside the can 100, a permanent magnet type rotor assembly 8 of a stepping motor is rotatably disposed. The rotor assembly 8 is made of a permanent magnet material in a cylindrical shape, and is formed integrally with a rotating member 160 made of resin or the like. The rotational force of the rotating member 160 is transmitted to the speed reduction mechanism indicated by the reference numeral 40 as a whole.

  The reduction mechanism 40 incorporated in the rotor uses a planetary gear mechanism that realizes a large reduction ratio, and is rotated by a sun gear 41 formed integrally with the rotating member 160 and a carrier that meshes with the sun gear 41 and has a disk 42. The planetary gear 43 supported freely, the ring-shaped fixed gear 44 meshed with the planetary gear 43 and fixed to the inside of the cylindrical member 82 fixed to the valve body 10 side, and the entire carrier can be freely rotated. And an output gear 45 to be supported. The output gear 45 has internal teeth having a slightly different number of teeth from that of the fixed gear 44, and is rotatably supported on the receiving member 80 and includes a driver 46 that protrudes on the lower surface side. Yes. The driver 46 has a minus driver driver 54 and is inserted into the screw shaft 52. The rotation of the screw shaft 52 is converted into movement in the axial direction and transmitted to the valve stem 32 side via the ball 36. A disc spring 190 is interposed between the rotating member 160 on the rotor side and the fixed gear 44 on the speed reduction mechanism side to urge the rotating member 160 (sun gear 41) toward the support member 150.

Due to the pressure-receiving load based on the elastic force of the bellows 48 and the pressure difference between the inside and outside of the bellows 48, a force that is pulled upward acts on the valve stem 32, and the screw shaft 52 is always pushed upward to contact the female screw member 90. Absorbs play that exists between them. Since the valve chamber 14 and the inside of the can 100 are partitioned by the bellows 48, the inside of the can 100 is kept at a low pressure even if the refrigerant pressure in the valve chamber 14 is high. Therefore, even if the cylindrical protrusion 104 accompanied by abrupt deformation is formed in order to press-fit and fix the support member 150 that supports the shaft 152 on the top of the can 100, excessive stress is generated in the can 100. There is nothing. However, the bellows 48 is an expensive part, has poor moldability, requires complicated assembly work such as soldering, and is a bottleneck in reducing the manufacturing cost of the electric valve. If the bellows 48 is omitted, the inside of the valve chamber 14 and the inside of the can 100 are in communication with each other, and when the refrigerant pressure is high, the inside of the can 100 is exposed to high pressure, and the cylindrical protrusion 104 as described above is formed. When it is formed, excessive stress may be generated in the can 100, which is not preferable.
JP 2000-356278 A JP 2006-226369 A JP 2003-232465 A

  When the high-pressure refrigerant pressure in the valve chamber 14 reaches the inside of the can 100, the can 100 has a structure that can withstand the high pressure of the internal refrigerant, and at that time, a cylindrical protrusion that causes stress concentration It is preferable if a support structure for the shaft can be obtained instead. An object of the present invention is to provide a motor-operated valve that opens and closes according to the rotation output of an electric motor, and that improves the pressure resistance of a can in which a high-pressure refrigerant pressure in the valve chamber reaches the inside.

  In order to solve the above problems, an electric valve according to the present invention includes a valve body having a valve chamber and a valve seat formed therein, a valve body that adjusts the flow rate of fluid by contacting and separating from the valve seat, A cylindrical can fixed to the valve body and in communication with the valve chamber, a motor excitation stator mounted on the outer periphery of the can, and a rotationally supported and driven by the stator on the inner periphery of the can And a feed screw mechanism that converts the rotation of the rotor into a contact / separation operation of the valve body with respect to the valve seat, and the top of the can is formed in a substantially dome shape, and is separated from the can. In addition, a support member that supports an end portion on the top side of the can on the rotation shaft of the rotor is provided.

  According to this motor-operated valve, since the top of the can is formed in a substantially dome shape, it has a structure that can withstand the pressure from the inside and hardly cause stress concentration, and the high-pressure refrigerant pressure in the valve chamber is inside the can. Even if it reaches, the can is hard to deform.

  Hereinafter, embodiments of a motor-operated valve according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall structure of a motor-operated valve according to the present invention. In the embodiment shown in FIG. 1, the same symbols are attached to the members and parts that constitute the motor-operated valve shown in FIG. 12. The motor-operated valve denoted as a whole by reference numeral 1 operates with an excitation function and includes a drive unit 1a having a motor composed of a stator 2 and a rotor assembly 8, and a rotational driving force from the drive unit 1a is input to reduce the gear speed. A gear reducer portion 1b that outputs the rotated rotation, and a feed screw mechanism portion 1c that converts the reduced rotation from the gear reducer portion 1b into a displacement in the screw shaft direction by a screw action and outputs the displacement.

  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. A motor excitation device in which a coil 140 constituting the stator 2 of the electric motor is molded integrally with a resin, that is, a permanent support that is rotatably supported inside the stator 2 and the can 30 and is rotationally driven by the stator 2. And a magnet-type rotor assembly 8. The stator 2 and the rotor assembly 8 constitute a stepping motor as an example of an electric motor.

  The stator 2 is detachably fitted to the can 30 by a mounting bracket 180 formed by a leaf spring. In this example, the protrusion 102 formed on the can 30 is positioned by being elastically fitted into a hole 182 formed in the mounting bracket 180. The stator 2 is supplied with power by being connected to an external power source via the connector 141 and the lead 142 for excitation. 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 12 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 basically the same as that shown in FIG. The speed reduction mechanism 40 includes a sun gear 41 that is integral with the rotor assembly 8, a plurality of planetary gears 43 that are rotatably supported by the carrier 42 and meshed with the sun gear 41, and are fixedly supported by the valve body 10 and the planetary gear 43. A ring gear 44 that meshes with a part of the ring gear 44 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 driver 46 of the feed screw mechanism 1c via the output gear 45. In this embodiment, the planetary gear type reduction mechanism is provided as the reduction mechanism 40, but a gear train mechanism that is meshed in series instead of the planetary gear type reduction mechanism may be used. Alternatively, the speed reduction mechanism 40 is not always necessary, and the rotation of the rotor assembly 8 may be directly input to the feed screw mechanism 1c. Hereinafter, the speed reduction mechanism 40 and the feed screw mechanism 1c will be described in detail with reference to FIGS.

  FIG. 3 is a cross-sectional view showing details of the shaft 201 and the rotor assembly 8. The permanent magnet type rotor assembly 8 of the stepping motor is rotatably arranged by the shaft 201 inside the can 30. The rotor assembly 8 is formed in a top cylinder shape by a plastic material containing a magnetic material, and a cylinder body 202 as a peripheral wall and a sun gear member 204 disposed in the center are molded integrally. The sun gear member 204 is provided with a boss 205 that extends vertically downward at the center and has a through hole 203 for the shaft 201. A sun gear 41 that is one component of the speed reduction mechanism 40 is formed outside the boss 205.

  FIG. 4 is a sectional view showing details of (a) the cylindrical bearing 50 constituting the feed screw mechanism 1c, and (b) the screw shaft 52 and the ball 65. The cylindrical bearing 50 has a lower outer peripheral portion 207 fitted into the valve main body 10, and a stepped portion 64 of the valve main body 10 at the lower end outer edge portion via an upper flange portion 75 of a spring receiving main body 74 described later. It is supported by. The mounting portion 206 on the outer periphery of the cylindrical bearing 50 is mounted so as not to come out from the valve body 10 side by means such as pressing. Further, an annular recess 208 into which the seal 56 is fitted is formed on the outer peripheral portion 207. The upper end surface 209 of the cylindrical bearing 50 supports the output internal gear 45 of the speed reduction mechanism 40 from below, and the output shaft 46 of the speed reduction mechanism 40 is fitted to the upper inner peripheral portion 210 of the cylindrical bearing 50. Yes. The cylindrical bearing 50 has a female screw portion 51 formed in a lower portion of the inner periphery thereof, and the female screw portion 51 is screwed with a male screw portion 53 formed on the outer periphery of the screw shaft 52. The screw shaft 52 is formed with a slit-like recess 55 into which a projection 54 which is a flat driver portion of the output shaft 46 of the speed reduction mechanism 40 is inserted, and a ball 65 is fixed to the lower recess 211. The rotation of the screw shaft 52 is converted into axial movement and transmitted to the valve shaft 60 side via the ball 65. The screw shaft 52 may be provided with a convex portion, and the output shaft 46 may be provided with a concave portion into which the convex portion is inserted.

  FIGS. 5A and 5B are views showing details of the gear case 220 constituting the speed reduction mechanism 40, wherein FIG. 5A is a plan view and FIG. 5B is a cross-sectional view. The gear case 220 is a cylindrical member, and the lower part is fitted to the upper part of the valve body 10 (see FIG. 1). The four tongue pieces 222 formed so as to protrude upward from the upper end edge 221 of the gear case 220 have a tip 222a formed in a reverse taper shape having a width wider than that of the root 222b. A cut portion is formed. The tongue piece 222a is inserted into the recess 234 (see FIG. 6) of the ring gear 44 shown in FIG. 11 and heated, so that the plastic material of the ring gear 44 is melted and the ring gear 44 is securely fixed to the gear case 220. Is done.

  6A and 6B show details of the ring gear 44, in which FIG. 6A is a plan view, FIG. 6B is a sectional view taken along line XX ′ of FIG. 6A, and FIG. The ring gear 44 is, for example, a ring-shaped member made by molding plastic. A flange 233 is formed on the outer peripheral portion, and a concave portion 234 and a convex portion 232 for fixing to the upper portion of the gear case 220. Are alternately formed in the circumferential direction. On the inner peripheral side of the ring gear 44, ring gear teeth 235 that are one of the elements constituting the speed reduction mechanism 40 are formed.

  FIGS. 7A and 7B are diagrams showing details of the disc spring 240 that suppresses the noise caused by the floating of the ring gear 44 and the vibration during the rotation of the rotor, wherein FIG. 7A is a plan view and FIG. 7B is a side view. As shown in FIG. 1, the ring gear 44 fitted to the upper portion of the gear case 220 is prevented from being lifted by the disc spring 240 disposed between the rotor assemblies 8. In addition, vibration generated when the rotor rotates can be reduced by the spring property of the disc spring 240, and noise due to vibration can be suppressed. The disc spring 240 is a ring-shaped member having a hole 241 through which the boss 205 provided with the sun gear 41 of the rotor assembly 8 passes, and has a spring portion 242 extending in three directions from the outer periphery thereof.

  FIG. 8 is a diagram showing details of the carrier 42 and the planetary gear 43 constituting the speed reduction mechanism 40, where (a) is a plan view of the carrier 42, (b) is a cross-sectional view of the planetary gear 43, and (c) is a cross-sectional view. A sectional view of the carrier 42, (d) is a plan view of the carrier 42 covered with the plate 254. FIG. The carrier 42 is formed by molding plastic, for example, and includes a disk having a hole 250 through which the shaft 201 passes in the center, and three masts 251 and 3 extending upward at the peripheral edge of the upper surface thereof. The partition walls 252 are alternately provided in the circumferential direction. The planetary gear 43 is formed in a cylindrical shape, and has a hole 252 that is rotatably fitted to the mast 251 of the carrier 42 at the center, and a gear portion 253 at the outer periphery. The top surface of the carrier 42 in which the planetary gear 43 is fitted to each mast 251 is covered with a single washer-like plate 254, and the convex portions at the top of the mast 251 and the partition 252 are press-fitted into the holes 255 of the plate 254. Fixed.

  FIG. 9 is a cross-sectional view showing details of the output internal gear 45 constituting the speed reduction mechanism 40 and the output shaft 46 integral therewith. The output internal gear 45 has a bottomed cylindrical shape, and a hole 260 into which the cylindrical portion 262 of the output shaft 46 is press-fitted is formed at the center of the bottom wall. An internal gear 261 is formed on the inner periphery of the output internal gear 45. The output shaft 46 has a bottomed hole 263 that receives the shaft 201, and a convex portion 54 as a flat driver portion having a minus driver shape on the side opposite to the side where the hole 263 is formed. The convex part 54 as a flat driver part is inserted in the slit-shaped recessed part 55 of the screw shaft 52, as shown in FIG.

  In the speed reduction mechanism 40, the sun gear 41 of the rotor assembly 8 serves as an input gear, the planetary gear 43 supported by the carrier 42 includes the sun gear 41, a ring gear 44 in which internal teeth are formed as fixed gears, and an inner circumference. Are simultaneously meshed with the output internal gear 45 in which the internal teeth 161 are formed. The entire carrier 42 is supported so as to freely rotate on the output internal gear 45. The ring gear 44 and the output internal gear 45 are displaced from each other, and the number of teeth is slightly different from each other. When the planetary gear 43 rotates while revolving while meshing with the fixed ring gear 44, the output internal gear 45 rotates with respect to the ring gear 44 based on the difference in the number of teeth. Therefore, in the speed reduction mechanism 40, the input of the sun gear 41 is decelerated and output to the output internal gear 45, and is decelerated at a large reduction ratio of about 50 to 1, for example. The rotation of the rotor assembly 8 is reduced by, for example, 1/50 and transmitted to the output shaft 46 and further to the screw shaft 52. The screw shaft 52 can be rotated at a minute rotational speed, and the axial displacement of the screw shaft 52 according to the rotation can be controlled by the minute displacement, and the valve opening degree control with high resolution is achieved.

  FIG. 10 is an exploded perspective view of the main part of the motor-operated valve 1. Two pipes 20 and 22 are liquid-tightly attached to the valve body 10. A receiving member 68 for attaching the can 30 is welded to the upper outer periphery of the valve body 10. A cylindrical upper portion of the valve body 10 extends upward through the receiving member 68. The cylindrical upper portion includes a screw shaft 52 and a cylindrical bearing that is screw-engaged with the screw shaft, as shown in FIG. 50 is inserted. The lower end portion of the gear case 220 is fitted into the cylindrical upper portion of the valve body 10. Inside the gear case 220, the speed reduction mechanism 40 is disposed above the feed screw mechanism 1c. Four tongue pieces 222 and a recess 221 are formed in the upper part of the gear case 220, and the tip end portion 222a of the tongue piece 222 is formed to have a width dimension larger than that of the root portion 222b. The fixed ring gear 44, which is a constituent element of the speed reduction mechanism 40 and is made of resin or the like, has ring gear teeth 235 formed on the inner peripheral surface and four recesses 234 formed on the outer peripheral portion. The ring gear 120 is firmly fixed by inserting the concave portion 234 into the tongue piece 222 of the gear case 220 and heating the portion to melt the plastic fixed gear.

  Examples of the motor-operated valve according to the present invention include the following. In this motor-operated valve, the gear module m that determines the size of the gear teeth used in the speed reduction mechanism 40 is preferably 0.2 to 0.4. If the gear module m is made smaller than this range, the gear teeth are too small and difficult to manufacture, and it is necessary to increase the axial length to withstand the magnitude of the transmission torque. As a result, the length of the speed reduction mechanism 40 becomes longer. On the other hand, if the gear module m is made larger than the above range, it is easy to manufacture, but the gear diameter is increased, and the diameter of the speed reduction mechanism 40, that is, the size of the motor-operated valve is also increased. By adopting a so-called magic gear mechanism in which the number of teeth of the ring gear 44 and the output internal gear 45 is slightly different as a configuration of the speed reduction mechanism 40, a gear external shape, for example, a root diameter of the ring gear 44 As a result, a large reduction ratio such as a gear reduction ratio of 30 to 100 can be obtained while being extremely small, such as 15φ or less. The screw shaft 52 of the feed screw mechanism 1c can be a small triangular screw of M3 to M7 (or a trapezoidal screw or a square screw) having a screw pitch of 0.5 to 1 mm.

  Referring again to the embodiment shown in FIG. 1, the feed screw mechanism 1 c rotates the rotor assembly 8 transmitted to the output shaft 46 via the planetary gear speed reduction mechanism 40 and causes the valve body 61 of the valve shaft 60 to rotate. This is converted into a linear motion that moves toward and away from the valve seat 62. 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 the concave portion 55 formed at the upper end of the screw shaft 51, and transmits the rotation of the output shaft 46 to the screw shaft 51. 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. The force that pushes down the valve shaft 60 from the feed screw mechanism 1c in the valve closing direction is transmitted through 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, In order to remove backlash between the female screw portion 51 and the male screw portion 53, the valve body 10 is provided with a coil spring 70 that urges the valve shaft 60 in the valve opening direction.

  In order to support the coil spring 70, a metal bottomed cylindrical spring receiver 73 (spring covering member) is disposed in the valve chamber 12. The spring receiver 73 includes a cylindrical peripheral wall 74 that covers the outer peripheral surface of the valve shaft 60 except for a lower end portion, an outward flange portion 75 that is bent outward at the upper end thereof, and a lower end of the peripheral wall 74. And an inward flange portion 76 which is formed in such a manner as to be bent inward and leave a hole 77 through which the valve shaft 60 can pass. 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 element 61 formed at the tip of the valve shaft 60 is seated on the valve seat 62 so that the orifice 14 is moved. close. 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 path area between the valve body 61 and the orifice 14 is controlled with high accuracy, and the flow rate of the 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. Conventionally, a bellows is attached to the outside of the valve shaft 60 to prevent the refrigerant introduced into the valve chamber 12 from entering the can 30, and the fluid pressure acting on the bellows or the elastic force of the bellows itself. The valve shaft 60 was given an upward biasing force. According to the present embodiment, a bellows manufactured from an expensive material is not used, and entry of the refrigerant into the can 30 can be prevented by the seal 56 between the cylindrical bearing 50 and the valve body 10. In addition, if the parts in the can 30 are made of a material that does not swell by the refrigerant, or if foreign substances are prevented from entering the can 30 by a filter or the like, the refrigerant may enter the can 30.

  As described above, the coil spring 70 urges the feed screw mechanism 1c in the valve opening direction by its spring force, and therefore exists between the female threaded portion 51 of the cylindrical bearing 50 and the male threaded portion 53 of the screw shaft 52. The play is absorbed when the screw shaft 52 is moved upward with respect to the cylindrical bearing 50. Therefore, the arrangement relationship between the female screw portion 51 and the male screw portion 53 is as shown in FIG. 13A, and the state where the screw play B is absorbed is maintained. When the valve body 61 is closed, when the valve body 61 comes into contact with the valve seat 62, the reaction force is immediately transmitted from the male screw portion 53 to the female screw portion 51 without going through an invalid stroke for absorbing the screw play B. . When the valve body 61 is opened from the valve seat 62 when the valve is opened, the male threaded portion 53 moves following the female threaded portion 51 in the form shown in FIG. In the present embodiment, by providing the coil spring 70 in the valve chamber 12, the vertical dimension of the motor-operated valve can be made smaller than when the coil spring 12 is provided above the valve chamber 12.

  In this embodiment, a spring receiver 73 that covers the coil spring 70 is disposed inside the valve chamber 12, and its bottom is separated from the bottom surface of the valve chamber 12 and around and below the spring receiver 73. A space having a U-shaped cross section is formed. Therefore, the valve chamber 12 is formed wider than before, and a sufficient amount of refrigerant is stored inside. Experience has shown that the wider the valve chamber 12, the smaller the state change in the valve chamber 12 due to the refrigerant entering and leaving the valve chamber 12 during operation of the refrigeration cycle, and the lower the passage noise of the refrigerant. However, also in the structure of the valve body 10 of the present embodiment, such a reduction in passing sound can be realized. Furthermore, since the outside of the coil spring 70 is covered by the spring receiver 73, the coil spring 70 is protected from the flow of the refrigerant, and direct interference between the coil spring 70 and the flow of the refrigerant is eliminated. Accordingly, it is possible to avoid a situation in which the coil spring 70 is deformed or damaged due to the flow of the refrigerant, or dust that may be contained in the refrigerant adheres to the coil spring 70. Furthermore, the structure comprising the coil spring 70 and the spring receiver 73 is less expensive than the bellows.

  FIGS. 11A and 11B are views showing the support member 300 that supports the shaft 201 and its peripheral portion, in which FIG. 11A is a longitudinal sectional view, and FIG. 11B is a plan view. The support member 300 is formed by pressing a single metal plate. The support member 300 engages with the cylindrical inner hub portion 301 into which the shaft 201 of the rotor assembly 8 is inserted, and the inner wall of the can 30. A cylindrical outer hub portion 302 that protrudes in the same direction as 301 and a flat flange portion 303 that integrally connects the inner hub portion 301 and the outer hub portion 302 are provided. The outer hub portion 302 is fitted in a light press-fit state so as to have an interference fit on the inner wall of the can 30, preferably an interference fit close to the intermediate fit. The inner hub portion 301 is not press-fitted into the shaft 201 but is in a fitted state. The sun gear member 204 is in contact with the support member 300 at the inner peripheral portion thereof by the urging force of the disc spring 240 so that the rotational resistance of the rotor assembly 8 does not increase.

  The support member 300 is preferably a press-formed metal thin plate. Although the supporting member 300 can be a thin plate formed by resin molding, the strength of the resin product is much lower than that of the metal plate, so that it is necessary to increase the plate thickness. In addition, since the thermal expansion is larger than that in the case of metal, it is necessary to strictly control the dimensions. If the plate thickness is thick, the height of the can 30 is increased, and the vertical dimension of the motor-operated valve is increased accordingly, so that it is preferable to form a metal press-molded product that can reduce the plate thickness. The support member 300 having the shape shown in the figure has a shape / structure obtained by simple press molding.

  The top portion 31 of the can 30 has a substantially domed shape with a short height. A perfect hemispherical structure is selected for the structure having the highest pressure resistance. However, when this is done, the height of the top 31 of the can 30 increases, and the vertical dimension of the motor-operated valve also increases. Therefore, by lowering the height from the hemisphere and making it a flat, generally domed shape with a smooth curved surface, it avoids stress concentration and ensures the necessary pressure resistance performance, while ensuring the required pressure resistance performance. It becomes possible to hold down the direction dimension.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made to the above-described embodiment without departing from the gist of the present invention.

It is sectional drawing which shows the whole structure of one Example of the motor operated valve of this invention. It is principal part sectional drawing which shows the other Example of the motor operated valve of this invention. Sectional drawing which shows the detail of a bearing, a shaft, and a rotor assembly. Sectional drawing which shows the detail of a holder, a screw bearing, a screw shaft, and a ball | bowl. The top view and side view which show the detail of the gear case which comprises a deceleration mechanism. The top view which shows the detail of the fixed gear 120, sectional drawing, and a side view. The top view and side view of a disc spring which prevent the floating of a fixed gear. The top view and sectional drawing which show the detail of the carrier and planetary gear which comprise a deceleration mechanism. Sectional drawing which shows the detail of the output gear and output shaft which comprise a deceleration mechanism. The exploded perspective view of the principal part. The enlarged view of a supporting member. It is sectional drawing which shows an example of the conventional motor operated valve provided with a bellows.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorized valve 1a Drive part 1b Gear speed reducer part 1c Feed screw mechanism 1d Valve main-body part 2 Stator 8 Rotor assembly 10 Valve main body 14 Valve chamber 16 Orifice 20, 22 Piping 30 Can 40 Planetary gear type reduction mechanism 41 Sun gear 42 Carrier 43 Planetary gear 44 Ring gear 45 Output internal gear 46 Output shaft 50 Cylindrical bearing 51 Female threaded part 52 Screw shaft 53 Male threaded part 54 Convex part 55 Concave part 56 Seal 60 Valve shaft 61 Valve body 62 Valve seat 63 Valve hole 64 Step part 65 Ball 66 Ball receiving member 67 Stepped portion 68 Receiving member 70 Coil spring 71 Upper end portion 72 Other end portion 73 Spring receiver (spring covering member) 74 Spring receiving body 75 Upper flange portion 76 Lower flange portion 77 Hole 80 Coil spring 81 Upper end portion 82 Lower end 83 Concave groove 201 Shaft (rotating shaft) 202 Cylindrical body 300 Support member 3 1 inner hub portion 302 outer hub portion 303 flange portion

Claims (5)

  A valve body having a valve chamber and a valve seat formed therein, a valve body that adjusts a flow rate of fluid by contacting and separating from the valve seat, and a cylindrical shape that is fixed to the valve body and communicates with the valve chamber A can, a motor excitation stator mounted on the outer peripheral portion of the can, a rotor rotatably supported on the inner peripheral portion of the can, and driven to rotate by the stator; A feed screw mechanism for converting into a contact / separation operation with respect to the valve seat, and forming the top of the can in a dome shape, and separately forming the top of the can on the rotating shaft of the rotor. An electrically operated valve provided with a supporting member for supporting.   The motor-operated valve according to claim 1, wherein the top portion of the can is formed in a substantially dome shape that is shorter than a hemispherical shape.   The motor-operated valve according to claim 1, wherein the support member is formed by press-molding a single metal plate.   The support member includes a cylindrical inner hub portion into which the rotation shaft of the rotor is inserted, a cylindrical outer hub portion that engages with an inner wall of the can and protrudes in the same direction as the inner hub portion, The motor-operated valve according to claim 3, further comprising a flat flange portion that integrally connects the inner hub portion and the outer hub portion.   5. A gear reducer for transmitting and connecting between the rotor and the feed screw mechanism is provided in order to reduce and transmit the rotation of the rotor to the feed screw mechanism. The motor operated valve according to any one of the above.

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