JP2016217409A - Motor valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor valve capable of reducing noise generated in a case where fluid flows in a first flow direction or second flow direction, while suppressing flow rate loss of fluid with a simple structure, without greatly changing a conventional motor valve.SOLUTION: In a valve chamber 7, disposed is a porous body 4 whose portion corresponding to a first opening 11a provided at the side part of a valve body 5, over a vertical range from below the lateral of a valve port 9 up to a position lateral to a sleeve part 14d of a cylindrical holding member 14 and below the ceiling surface of the valve chamber 7 in the valve body 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor-operated valve, for example, a motor-operated valve used in a heat pump air conditioning system.

  Conventionally, the development of a motor-operated valve aimed at miniaturization, large capacity, and power saving has been promoted. As an example of such a conventional motor-operated valve, Patent Document 1 discloses a technique in which a force acting in the valve closing direction is made as small as possible and a valve-opening spring having a smaller spring load can be used. Yes.

  The motor-operated valve disclosed in Patent Document 1 includes a valve chamber, a first lateral inlet / outlet opening in the valve chamber, a valve port with a vertical valve seat opening in the valve chamber, and a second connected to the valve port. A valve body having an inlet / outlet; a valve body disposed in the valve chamber so as to be movable up and down in order to open and close the valve opening; an elevating drive means having an electric motor for raising and lowering the valve body; and the valve body A valve opening spring that biases the valve in the valve opening direction, and the diameter of the valve port and the diameter of the back pressure chamber defined above the valve body are set to be substantially the same, and the valve A pressure equalization passage having a lower end surface opened to allow communication between the valve opening and the back pressure chamber is provided in the body, and a value obtained by dividing a lower end opening area of the pressure equalization passage by the valve opening area is within a predetermined range. The dimension of each part is set so that it may become.

  By the way, in this kind of motor operated valve, the fluid (refrigerant) is bi-directional between the first flow direction from the first inlet / outlet to the second inlet / outlet and the second flow direction from the second inlet / outlet to the first inlet / outlet. For example, when a refrigerant made of gas (gas refrigerant) is flowed in the first flow direction in an excessive gas state, the left and right portions of the valve opening and the valve body are viewed from the first inlet / outlet side as viewed from the valve chamber. There was a problem that a periodic vortex flow was generated near the area between the inner wall surface and abnormal noise was generated. Further, for example, when the refrigerant flows in the second flow direction in an excessive gas state, a region between the portion of the valve port opposite to the first inlet / outlet and the inner wall surface of the valve body (particularly, of the region) There is a problem that a periodic vortex is generated in the vicinity of the area close to the valve opening), and abnormal noise is generated accordingly (see FIG. 4). Specifically, for example, when the refrigerant flows in the first flow direction in an excessive gas state, the above-described periodic vortex flow is generated with a high differential pressure and an extremely small valve opening. (See FIG. 5).

  The generation of abnormal noise during such use has been a concern in various valve devices, and Patent Documents 2 and 3 disclose that abnormal noise is suppressed in expansion valves and dry valves used in refrigeration cycles. The prior art is disclosed.

  An expansion valve disclosed in Patent Document 2 includes a main body having an opening on a side surface and a lower surface and a space inside, a valve body and a valve seat that form a throttle portion inside the main body, and an upper portion connected to the valve body. A shaft having a rotor, a case surrounding the shaft and the rotor, a stator positioned on the outer periphery of the rotor, support means for supporting the valve body and the shaft, and a first opening coupled to a side opening of the main body. An expansion valve having a first pipe and a second pipe coupled to an opening on the lower surface of the main body, wherein the expansion valve is located inside the main body, one end is fixed to the main body and the other end is fixed to the supporting means, The hollow rectification | straightening means which has this through-hole is provided.

  In addition, the dry valve disclosed in Patent Document 3 is provided with a passage communicating with the valve chamber and the valve outlet in a closed state on the peripheral side of the valve seat, and a throttle made of a porous body is disposed in the passage, Furthermore, an elastic body that comes into contact with the porous body when the valve is closed is provided on the valve stem side of the dry valve so that the elastic body functions as a valve body and the porous body functions as a valve seat. .

JP 2013-130271 A JP-A-9-3109939 JP 2002-235969 A

  However, in the prior art disclosed in Patent Document 2, the refrigerant that has flowed from the first pipe flows into the space formed by the main body and the rectifying means, and the valve body from the plurality of through holes formed in the rectifying means. The valve body and the case due to pressure fluctuations caused by the non-uniform state of the refrigerant, because it flows into the space where the air flows, passes through the throttle portion formed by the valve body and the valve seat, and flows to the second pipe. However, there is a problem that the flow rate loss of the refrigerant increases and the arrangement of the rectifying means becomes complicated.

  Further, in the prior art disclosed in Patent Document 3, the gas-liquid two-phase flow is rectified when the refrigerant passes through the porous body, and the gas-liquid two-phase flow in which the refrigerant flow noise is most noticeable flows. Since the flow is made uniform and the pressure is reduced in this uniform state, discontinuous noise is reduced and a silencing effect is obtained, but the problem that the flow rate loss of the refrigerant increases and the porous body functions as a valve seat The problem that it is necessary occurs.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to suppress a fluid flow loss with a simple configuration without greatly changing the conventional motor-operated valve, An object of the present invention is to provide a motor-operated valve capable of reducing noise generated when a fluid flows in a first flow direction or a second flow direction.

  As a result of earnest research, the present inventors have arranged a vortex generation prevention means made of a porous body in a region including the side of the valve port, so that the fluid flows in the first flow direction and the second flow direction in the motor-operated valve. It has been found that the abnormal noise generated when flowing can be effectively reduced.

  That is, in order to solve the above-described problem, the motor-operated valve according to the present invention includes a valve body having a valve chamber defined therein and first and second openings formed in a side portion and a bottom portion, A valve seat member having a valve opening and a valve seat that opens in the valve chamber and provided in the second opening of the valve body; a valve body disposed in the valve chamber so as to be movable up and down; and the valve body A cylindrical holding member having an elevating drive unit that elevates and lowers with respect to the valve seat, and a sleeve portion that is fixed to the valve main body and that slidably fits and holds the valve body so as to project a part of the valve body. The valve chamber, from the side of the valve port, from the side of the sleeve portion of the tubular holding member and from the ceiling surface of the valve chamber in the valve body. A porous body in which a portion corresponding to the first opening is cut out over a vertical range up to a lower position. It is characterized in that it is set.

  In a preferred embodiment, the porous body is fixed to the valve seat member.

  In another preferred aspect, the porous body is fixed in a state having a predetermined gap with the inner wall surface of the valve body.

  Preferably, the porous body is at least one of a mesh member in which a wire is woven in a mesh shape, a laminate in which a plurality of mesh members are laminated, a foam member, and a plate-like member in which a plurality of openings are formed. Consists of

  More preferably, the porous body is composed of a mesh member in which wires are woven in a mesh shape.

  The porous body may be formed by folding. In that case, the porous body comprises a short side portion having a relatively high lower end position and a short vertical length, and a long side portion having a relatively low end position and a long vertical direction, It is good to form by folding according to the outer periphery shape of the said valve seat member so that a part may be folded so that it may overlap with the said long side part, and the said long side part may be located inside the said short side part.

  In a further preferred aspect, the porous body is aligned with an end portion of the short side portion opposite to the long side portion side and an end portion of the long side portion opposite to the short side portion side. Are joined.

  In a further preferred aspect, the porous body is fixed by joining a portion of the long side portion that does not overlap the short side portion to the valve seat member.

  According to the motor-operated valve of the present invention, the side of the sleeve portion of the cylindrical holding member that holds the valve body in a vertically movable manner from below the side of the valve port, and the ceiling of the valve chamber in the valve body. Since a porous body in which a portion corresponding to the first opening provided in the side portion of the valve body is cut is provided over a vertical range up to a position below the surface, the first flow direction and the first flow direction When a fluid (gas refrigerant) flows in two flow directions, the porous body generates vortex near the region between the valve port and the inner wall surface of the valve body, particularly protruding from the sleeve portion of the cylindrical holding member. The generation of eddy currents in the vicinity of the exposed part of the valve body can be suppressed, so that the electric valve can be controlled while suppressing fluid flow loss with a simple configuration without making a major change to the conventional electric valve. Can be effectively reduced.

The longitudinal cross-sectional view which shows one Embodiment of the motor operated valve which concerns on this invention. AA arrow sectional drawing of FIG. The figure explaining the preparation process of the porous body (mesh member) shown in FIG. 1, and the assembly | attachment process of a valve seat member and a porous body. The figure which shows the generation | occurrence | production location of the vortex | eddy_current at the time of valve opening of the electrically operated valve of a conventional structure. The figure which shows the experimental result which measured the presence or absence of generation | occurrence | production of the vortex | eddy_current at the time of valve opening of the electrically operated valve of a conventional structure.

  Hereinafter, embodiments of a motor-operated valve according to the present invention will be described with reference to the drawings.

[Embodiment 1]
FIG. 1 is a longitudinal sectional view showing an embodiment of a motor-operated valve according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. In FIG. 2, the valve body is omitted.

  The motor-driven valve 1 of the illustrated embodiment is used as an expansion valve in, for example, a heat pump air conditioning system, and the fluid (refrigerant) flows in both directions (the first flow direction and the opposite second flow direction), and at least This is a bidirectional flow-type motor-operated valve corresponding to a flow path in which a large flow rate flows in one direction.

  The motor-operated valve 1 mainly includes a valve body 5 having a cylindrical base 6 made of sheet metal, a can 58 fixed to the valve body 5, and an internal space defined by the valve body 5 and the can 58. A support member 19 that is fixedly arranged, a valve body 20 that is supported by the support member 19 and that can be moved up and down in the internal space, and a stepping motor that is attached above the valve body 5 to raise and lower the valve body 20 ( Elevating drive unit) 50.

  The tubular base 6 of the valve body 5 has a valve chamber 7 defined therein, and a lateral first opening 11a that opens to the valve chamber 7 is formed on the side thereof, and the valve chamber 7 is formed on the bottom thereof. A vertically extending second opening 12a is formed. A stepped cylindrical valve seat member 8 having a vertical valve port 9 and a valve seat 8a that opens into the valve chamber 7 is fixed to the second opening 12a formed at the bottom of the cylindrical base 6 of the valve body 5. Has been. Then, a transverse conduit joint 11 is attached to the first opening 11a formed on the side of the cylindrical base 6 by brazing or the like, and has a diameter larger than that of the valve port 9 formed on the bottom 8C side of the valve seat member 8. A vertical conduit joint 12 communicating with the valve port 9 of the valve seat member 8 is attached to the connection port 12b by brazing or the like.

  More specifically, the valve seat member 8 is made of metal such as SUS, for example, and its short cylindrical bottom 8C is fitted into the second opening 12a and fixed to the cylindrical base 6 of the valve body 5. The conduit joint 12 is fitted and attached to the connection port 12b formed on the bottom 8C side. The valve seat member 8 has a small-diameter upper portion 8A provided with the valve seat 8a and a large-diameter lower portion 8B into which the conduit joint 12 is fitted. An inclined surface 8b connected to the valve seat 8a is formed at the upper end, and the upper end of the inclined surface 8b is slightly near the center of the conduit joint 11 attached to the first opening 11a or slightly in the center of the conduit joint 11. And the valve seat member 8 and the conduit joint 11 so that the valve seat 8a (the upper end portion of the valve port 9) is positioned on the side of the conduit joint 11 attached to the first opening 11a. Are arranged. Further, the outer diameter of the small-diameter upper portion 8A of the valve seat portion seat 8 is substantially the same as the outer diameter of a cylindrical holding member 14 (sleeve portion 14d) of the support member 19 described later. The outer diameter of the lower portion 8B is slightly larger than the outer diameter of the cylindrical holding member 14 (the sleeve portion 14d).

  A stepped tubular base 13 having a diameter decreasing upward is attached to the upper opening of the tubular base body 6 of the valve body 5, and the bottom surface of the tubular base 13 forms the ceiling surface of the valve chamber 7. Is formed. A lower end portion of a cylindrical can 58 having a ceiling portion is joined to the upper end portion of the cylindrical base 13 by welding or the like.

  The support member 19 includes a cylindrical holding member 14 with a partition wall 14c and a bearing member 15 with a female screw 15i. The cylindrical holding member 14 is disposed on the inner side of the cylindrical base 13 at a portion below the partition wall 14c. A cylindrical sleeve portion 14d is fixed by press fitting or the like so as to protrude into the valve chamber 7. Further, a cylindrical female screw bearing member 15 in which a female screw 15i is screwed below the inner peripheral surface is fixed to the upper portion of the cylindrical holding member 14 by caulking or the like. A protruding portion 15a is formed on the center side of the lower surface of the bearing member 15 with the female screw, and a female screw 15i is also screwed to the protruding portion 15a. A spring chamber 14a is defined between the partition wall 14c of the cylindrical holding member 14 and the bearing member 15 with the internal thread, and a valve opening spring 25 for energizing the valve body 20 in the valve opening direction is accommodated in the spring chamber 14a. Has been.

  The valve body 20 is formed of a cylindrical body in which a pressure equalizing passage 32 is formed at the center of the valve body 20 along the ascending / descending direction (vertical direction) of the valve body 20, and the upper portion of the valve body 20 is in the cylindrical holding member 14. The valve body guide hole 14b below the partition wall 14c is slidably fitted, and the lower part of the valve body 20 is connected to the valve seat member 8 (of the valve body guide hole 14b) from the tubular holding member 14 (the valve body guide hole 14b). It projects towards the valve port 9). The valve body 20 includes, from above, an upper cylindrical portion 20b having a constant inner diameter, and a skirt portion 20c whose inner diameter continuously increases toward the valve port 9 of the valve seat member 8. The center hole of the upper cylindrical portion 20b is a fitting hole 20d into which the small diameter lower portion 23c of the thrust transmission member 23 is fitted and fixed, and the lower end portion of the skirt portion 20c is in contact with and separated from the valve seat 8a of the valve seat member 8. A valve body portion 20a having a substantially truncated cone shape for opening and closing the valve port 9 is provided. The inner diameter of the upper cylindrical portion 20b and the inner diameter of the upper end portion of the skirt portion 20c are the same. Therefore, the inner peripheral surface of the upper cylindrical portion 20b is continuously connected to the inner peripheral surface of the skirt portion 20c.

  Further, in the present embodiment, the porous body 4 as the eddy current generation preventing means is fixed to the outer periphery of the large diameter lower portion 8B of the valve seat member 8. The porous body 4 is made of a mesh member in which a metal wire material such as SUS is woven in a mesh shape. From the outer periphery of the large-diameter lower portion 8B, the porous body 4 is formed on the side (outside) of the valve port 9 of the valve seat member 8. It extends beyond the position to the side of the sleeve portion 14d of the cylindrical holding member 14 (that is, a position above the lower end of the sleeve portion 14d of the cylindrical holding member 14 and below the ceiling surface of the valve chamber 7). The first opening 11a extends in the up-and-down direction (vertical direction) of the valve body 20 so as not to hinder the flow of fluid flowing through the inside of the conduit joint 11 attached to the first opening 11a and the valve chamber 7. The cross section has a C-shaped cross-section cut out (see FIG. 2). In other words, the porous body 4 covers the periphery of the portion of the valve body 20 protruding from the cylindrical holding member 14 (the valve body guide hole 14b) except for the portion corresponding to the first opening 11a. The valve seat member 8 is disposed over a vertical range from the side of the valve opening 9 to the side of the sleeve portion 14d of the cylindrical holding member 14 and the position below the ceiling surface of the valve chamber 7. Yes. Here, as described above, since the outer diameter of the large-diameter lower portion 8B of the valve seat portion seat 8 is made larger than the outer diameter of the sleeve portion 14d of the cylindrical holding member 14, the porous body 4 is held in the cylindrical shape. On the side of the sleeve portion 14d of the member 14, the sleeve portion 14d is disposed at a distance from the sleeve portion 14d. Further, the thickness of the porous body 4 is smaller than the distance between the large-diameter lower portion 8B (the outer peripheral surface thereof) of the valve seat member 8 and the cylindrical base body 6 (the inner wall surface thereof). Is held in the valve chamber 7 with a predetermined gap α between the valve body 5 and the inner wall surface of the cylindrical base 6.

  More specifically, as shown in FIG. 3, the porous body 4 (mesh member) has a rectangular sheet-like short side portion 4a whose lower end position is relatively high and whose vertical length is short and the lower end position is relative to each other. It is produced from a blank material composed of a rectangular sheet-like long side portion 4b having a low vertical length and a long vertical length. The blank material is folded using a vertically extending boundary 4c defined between the short side 4a and the long side 4b so that the short side 4a overlaps the long side 4b. The portion 4b is deformed into a C-shaped cross section in accordance with the outer peripheral shape of the large-diameter lower portion 8B of the valve seat member 8 so that the portion 4b is located inside the short side portion 4a, and the short side portion 4a and the long side portion 4b The porous body 4 is formed by joining together by welding or the like. Here, the lateral length la of the short side part 4a is slightly longer than the lateral length lb of the long side part 4b, and when deformed, the lateral side length la is opposite to the long side part 4b side of the short side part 4a. Since the end portion 4c and the end portion 4d of the long side portion 4b are designed to coincide with the end portion 4d opposite to the short side portion 4a side, the end portion 4c of the short side portion 4a and the end portion of the long side portion 4b are designed. The shape of the porous body 4 is maintained by joining the two upper and lower portions in a state where the portion 4d is aligned (welded portion 4f). And the lower end part of the porous body 4 which consists of the part (non-overlapping part) which does not overlap with the short side part 4a among the long side parts 4b is externally fitted in the large diameter lower part 8B of the valve seat member 8, and the non-overlapping part is set. Joined to the outer periphery of the large-diameter lower portion 8B of the valve seat member 8 by welding or the like (in this embodiment, three spots in the circumferential direction of the porous body 4 having a C-shaped cross section and its middle portion (not shown) are spotted. The porous body 4 is fixed to the valve seat member 8 by welding and joining 4g).

  In addition, the valve seat member 8 to which the porous body 4 is fixed is attached to the valve port 9 with the conduit joint 12, and the notched portion of the porous body 4 having a C-shaped cross section is formed in the cylindrical base 6 ( The cylindrical base body 6 is dropped from the upper opening of the cylindrical base body 6 while being aligned with the conduit joint 11 attached to the first opening 11a of the cylindrical base body 6) to which the conduit joint 11 is previously attached. It is inserted into the inside (that is, inside the valve chamber 7), and its bottom 8C is fixed to the second opening 12a of the cylindrical base 6 by caulking or the like. Thereafter, the motor-driven valve 1 is assembled by joining the cylindrical base body 13 to which the support member 19, the valve body 20, the rotor 57, the can 58 and the like are attached to the upper opening of the cylindrical base body 6 by welding or the like. It will be.

  On the other hand, a stepping motor 50 attached above the valve body 5 is rotatable with respect to the can 58 inside a stator 55 including a yoke 51, a bobbin 52, a coil 53, a resin mold cover 54, and the like. And a rotor 57 having a rotor support member 56 fixed to the inside of the upper portion thereof. The stator 55 is externally fixed to the can 58. Further, on the inner peripheral side of the rotor 57, a sun gear 41 formed integrally with the rotor support member 56, and a fixed ring gear 47 fixed to the upper end of the cylindrical body 43 fixed to the upper part of the cylindrical holding member 14. A planetary gear 42 that is disposed between the sun gear 41 and the fixed ring gear 47 and meshes with each other, a carrier 44 that rotatably supports the planetary gear 42, and a bottomed ring shape that meshes with the planetary gear 42 from the outside. Output gear 45, and a strange planetary gear type speed reduction mechanism 40 including an output shaft 46 and the like whose upper portion is fixed by press-fitting into a hole formed at the bottom of the output gear 45. Here, the number of teeth of the fixed ring gear 47 is set to be different from the number of teeth of the output gear 45.

  A hole is formed in the central portion of the upper portion of the output shaft 46, and the lower portion of the support shaft 49 that is inserted through the central portion of the sun gear 41 (rotor support member 56) and the carrier 44 is inserted into the hole. The upper portion of the support shaft 49 has an outer diameter that is substantially the same as the inner diameter of the can 58, and is formed in a hole formed at the center of the support member 48 that is disposed on the upper side of the rotor support member 56 and inscribed in the can 58. It is inserted. The rotor 57 itself does not move up and down inside the can 58 by the support member 48 or the like, and the positional relationship with the stator 55 that is externally fitted and fixed to the can 58 is always maintained constant.

  The lower part of the output shaft 46 of the speed reduction mechanism 40 is rotatably fitted on the upper part of the bearing member 15 with a female thread that constitutes the support member 19 that supports the output shaft 46 and the like. A slit-like fitting portion 46a extending in the lateral direction so as to pass therethrough is formed. A plate-like portion 17c protrudes from the upper end of the rotary elevating shaft 17 on which a male screw 17a screwed with a female screw 15i screwed on the lower side of the inner peripheral surface of the bearing member 15 with the female screw is provided. A slit-like fitting portion 46a is slidably fitted. When the output shaft 46 rotates according to the rotation of the rotor 57, the rotation of the output shaft 46 is transmitted to the rotary elevating shaft 17, and the rotary elevating shaft 17 is driven by screw feed of the female screw 15 i of the bearing member 15 and the male screw 17 a of the rotary elevating shaft 17. Moves up and down while rotating.

  A stepped cylindrical thrust transmission member 23 is disposed below the rotary elevating shaft 17 so as to transmit the thrust downward of the rotary elevating shaft 17 via the ball 18 and the ball seat 16.

  The thrust transmission member 23 is an intermediate body portion that is slidably inserted from above into a hole formed in a large-diameter upper portion 23a into which the ball seat 16 is fitted on the inner periphery and the partition wall 14c of the cylindrical holding member 14 from above. 23b, a small diameter lower portion 23c having a diameter smaller than that of the intermediate body portion 23b, and a longitudinal through hole 32d constituting an upper portion of the pressure equalizing passage 32 formed in the valve body 20 and a back described later. A plurality of lateral holes 32 e that open to the pressure chamber 30 are formed. The upper end opening of the through hole 32d is closed by the ball seat 16.

  As described above, the small-diameter lower portion 23c of the thrust transmission member 23 is fitted and fixed to the fitting hole 20d of the upper cylindrical portion 20b of the valve body 20 by press fitting or the like, and the valve body 20 and the thrust transmission member 23 are integrally formed. Go up and down. A pressing member 24 is sandwiched and fixed between the upper end surface of the valve body 20 and the lower end step portion of the intermediate body portion 23b of the thrust transmission member 23 when the small-diameter lower portion 23c is press-fitted. A seal member 38 such as an O-ring is mounted between the annular groove formed in the upper end portion of the valve body 20 and the valve body guide hole 14b.

  Further, as described above, the valve-opening spring 25 made of a compression coil spring is disposed in the spring chamber 14a above the partition wall 14c of the cylindrical holding member 14 with its lower end in contact with the partition wall 14c. At the same time, in order to transmit the urging force (lifting force) of the valve-opening spring 25 to the valve body 20 through the thrust transmission member 23, a lifting spring receiving body 28 having hook-like hook portions 28a and 28b on the upper and lower sides is arranged. Has been. The upper hooking portion 28 a of the lifting spring receiver 28 is placed on the upper portion of the valve opening spring 25, and the lower hooking portion 28 b is hooked on the lower end step portion of the large diameter upper portion 23 a of the thrust transmission member 23. The cylindrical holding member 14 is formed with a communication hole 14d that allows the spring chamber 14a and the can 58 to communicate with each other.

  Therefore, when the rotor 57 of the motor 50 is rotationally driven in one direction, the rotation of the rotor 57 is transmitted to the rotary lift shaft 17 through the output shaft 46 of the speed reduction mechanism 40 and transmitted to the female screw 15i of the bearing member 15 with the female screw. For example, the rotary lift shaft 17 is lowered while being rotated by screw feed by the male screw 17 a of the rotary lift shaft 17, and the thrust transmission member 23 and the valve body 20 resist the biasing force of the valve opening spring 25 by the thrust of the rotary lift shaft 17. The valve body 20a consisting of the lower end of the skirt 20c of the valve body 20 is finally seated on the valve seat 8a and the valve port 9 is closed (see FIG. 1). On the other hand, when the rotor 57 of the motor 50 is rotationally driven in the other direction, the rotation of the rotor 57 is decelerated and transmitted to the rotary lift shaft 17 via the output shaft 46 of the speed reduction mechanism 40, and is transmitted by the female screw 15i and the male screw 17a. For example, the rotary lift shaft 17 is raised while being rotated by screw feed, and accordingly, the thrust transmission member 23 and the valve body 20 are pulled up by the urging force of the valve-opening spring 25, and the valve body portion 20a is separated from the valve seat 8a. Mouth 9 is opened.

  A back pressure chamber 30 is defined above the valve body 20 and between the pressing member 24 and the partition wall 14c of the cylindrical holding member 14. In the valve body 20, a thick passage formed of an inner peripheral surface of a skirt portion 20 c having a lower end opened toward the valve port 9 from below to communicate the lower end portion of the valve body 20 and the back pressure chamber 30. A pressure equalizing passage 32 having a portion 32b and a narrow passage portion 32c (fitting hole 20d) formed of the inner peripheral surface of the upper cylindrical portion 20b is formed, and the narrow passage portion 32c is formed as a through hole 32d and a thrust transmission member 23. The back pressure chamber 30 communicates with the lateral hole 32e. Here, the balance between the push-down force (force acting in the valve closing direction) acting on the valve body 20 and the push-up force (force acting in the valve opening direction) acting on the valve body 20 in the valve-closed state is canceled (the differential pressure is canceled). Therefore, the diameter of the back pressure chamber 30 and the diameter of the valve port 9 are set to be substantially the same.

  In the electric valve 1 having such a configuration, when the rotor 57 of the motor 50 is rotationally driven in the other direction and the valve port 9 is opened, the fluid (refrigerant) flows in the first flow direction (the conduit connected to the first opening 11a). The flow from the joint 11 toward the conduit joint 12 connected to the valve seat member 8 of the second opening 12a) and the opposite second flow direction are performed. When flowing in the first flow direction or the second flow direction in an excessive state, the porous body 4 having a C-shaped cross section disposed at least in a region including the side of the valve port 9 of the valve seat member 8, A region between the valve port 9 and the inner wall surface of the valve body 5 (particularly, when the refrigerant flows in the first flow direction, the left and right portions of the valve port 9 are viewed from the first opening 11a side when viewing the valve chamber 7). The region between the inner wall surface of the valve body 5 and the first of the valve port 9 when the fluid flows in the second flow direction. The periodicity of the vortex generated in the region between the portion opposite to the port 11a and the inner wall surface of the valve body 5 and particularly in the region close to the valve port 9) is lost, and the vortex flow in that region is lost. Since generation | occurrence | production is suppressed, the abnormal noise which arises in the motor operated valve 1 can be reduced.

  In particular, in the present embodiment, a part of the valve body 20 protrudes (exposes) from the tubular holding member 14 (the valve body guide hole 14b), and the vortex generated around the exposed portion of the valve body 20 It has been confirmed by experiments by the present inventors that the valve body 20 vibrates and this vibration is transmitted to other parts connected to the valve body 20 to resonate and the abnormal noise increases accordingly. The porous body 4 is formed from below the side of the valve port 9 from the side of the sleeve portion 14d of the cylindrical holding member 14 and from the ceiling surface of the valve chamber 7 in the valve body 5 so as to cover the periphery of the exposed portion. Since it extends to a lower position, the generation of vortex near the exposed portion of the valve body 20 is suppressed, and the above-described resonance phenomenon is reliably prevented. It can reduce more effectively.

  Specifically, when the refrigerant flows in the first flow direction in an excessive gas state, the pressure difference between the conduit joint 11 side and the conduit joint 12 side is high (about 0.7 to 2.0 MPa). It is the present inventors that the vortex flow (see FIG. 5) generated in the motor-driven valve having the conventional structure disappears reliably when the energization pulse amount to the stepping motor 50 of the motor-operated valve 1 is changed from 150 pulses to 300 pulses. Confirmed by experiments.

  In the motor-operated valve 1 according to the present embodiment, the porous body 4 is fixed to the outer periphery of the valve seat member 8 with a predetermined gap α between the porous body 4 and the inner wall surface of the valve body 5. By fixing 4 to the valve seat member 8 by welding or the like, the motor-operated valve 1 can be easily assembled in the same procedure as the conventional motor-operated valve. Further, since the porous body 4 is arranged at a distance from the sleeve portion 14d of the cylindrical holding member 14, the assembly process of the motor-operated valve 1 can also be simplified by this.

  In the motor-operated valve 1 of the present embodiment, the porous body 4 serving as the eddy current generation preventing means is a mesh member in which a metal wire is woven in a mesh shape, and includes a short side portion 4a and a long side portion 4b. Using a mesh member formed by deforming the blank material so that the short side portion 4a is overlapped with the long side portion 4b and the long side portion 4b is positioned inside the short side portion 4a, the long side portion 4b is used. Since the part which does not overlap with the short side part 4a is joined and fixed to the valve seat member 8, the parameter management at the time of joining the porous body (mesh member) 4 to the valve seat member 8 becomes easy. Also by this, the manufacturing process of the said motor operated valve 1 can be simplified. That is, when joining the porous body 4 and the valve seat member 8 by, for example, resistance welding, a portion of the long side portion 4b that does not overlap the short side portion 4a is joined to the valve seat member 8 so as to be porous. Parameter management such as the pressing force of the electrodes against the body 4 and the valve seat member 8 and the current value becomes easy.

  Of course, the porous body 4 may be used as it is without folding the blank material, but when folded, the shape of the blank material is not the one shown in FIG. A rectangular shape may be folded and attached to the valve seat member 8. In other words, in this case, the folded and overlapped portion is joined to the valve seat member 8. Moreover, joining may be performed by any method other than resistance welding.

  Further, in the above-described embodiment, a mesh member in which a metal wire is woven in a mesh shape is adopted as the porous body 4 as the eddy current generation preventing means, but instead of the mesh member, for example, a metal foam member, A punching metal made of a metal plate (plate-like member) having a plurality of openings, a metal plate (plate-like member) having a plurality of openings formed by a photoetching method, or the like may be employed. May be. Further, in the above-described embodiment, a single mesh member is folded to form a laminated body, but it goes without saying that a laminated body in which a plurality of mesh members are laminated may be used. Of course, the porous body 4 may be formed of, for example, ceramic or resin other than metal. In addition, the foamed member and the metal plate (plate-like member) may be folded to form the porous body 4, and further, the laminated body in which the plurality of mesh members are stacked may be further folded to form the porous body 4. Of course.

  In the above-described embodiment, the valve body 20 has the skirt portion 20c whose inner diameter increases toward the valve port 9 of the valve seat member 8. However, the internal shape of the valve body 20 may be changed as appropriate. For example, the valve body 20 may have a constant inner diameter in the vertical direction.

  In the above description, the motor-operated valve of the present embodiment is used as an expansion valve in, for example, a heat pump air-conditioning system and the like, and is a bi-directional flow-type motor-operated valve in which fluid flows in both directions. Needless to say, the present invention can be applied to other systems other than the heat pump air conditioning system, and may be applied to a motor-operated valve in which a fluid flows only in one direction.

DESCRIPTION OF SYMBOLS 1 Motorized valve 4 Porous body 5 Valve body 6 Tubular base body 7 Valve chamber 8 Valve seat member 8A Small diameter upper part 8B Large diameter lower part 8C Bottom part 8a Valve seat 9 Valve port 11 Conduit joint 11a First opening 12 Conduit joint 12a Second opening 13 Cylindrical base 14 Cylindrical holding member 14c Bulkhead 14d Sleeve portion 15 Cylindrical bearing member 15i Female screw 17 Rotating lift shaft 17a Male screw 19 Support member 20 Valve body 20a Valve body portion 40 Strange planetary gear type reduction mechanism 50 Stepping motor (lifting drive) Part)
55 Stator 57 Rotor 58 Can

Claims (9)

A valve body having a valve chamber defined therein and having a first opening and a second opening formed in a side portion and a bottom portion; and a valve opening and a valve seat opening in the valve chamber; A valve seat member provided in the second opening, a valve body disposed in the valve chamber so as to be movable up and down, a lift drive unit that lifts and lowers the valve body with respect to the valve seat, and fixed to the valve body, A tubular holding member having a sleeve portion that slidably fits and holds the valve body so as to project a part of the valve body,
Among the valve chambers, a range from the lower side of the valve port to the side of the sleeve portion of the cylindrical holding member and a position below the ceiling surface of the valve chamber in the valve body extends in the vertical direction. A motor-operated valve comprising a porous body in which a portion corresponding to the first opening is cut out.   The motor-operated valve according to claim 1, wherein the porous body is fixed to the valve seat member.   The motor-operated valve according to claim 1 or 2, wherein the porous body is fixed in a state having a predetermined gap between the porous body and an inner wall surface of the valve main body.   The porous body is composed of at least one of a mesh member in which a wire is woven in a mesh shape, a laminate in which a plurality of mesh members are stacked, a foam member, and a plate member in which a plurality of openings are formed. The motor-operated valve according to any one of claims 1 to 3, wherein the motor-operated valve is provided.   The motor-operated valve according to claim 4, wherein the porous body is configured by a mesh member in which a wire is woven into a mesh shape.   The motor-operated valve according to any one of claims 1 to 5, wherein the porous body is formed by folding.   The porous body includes a short side portion having a relatively high lower end position and a short vertical length, and a long side portion having a relatively low lower end position and a long vertical direction. It is formed by being deformed in accordance with the outer peripheral shape of the valve seat member so that the long side portion is folded so as to overlap with the long side portion and the long side portion is located inside the short side portion. 6. The motor operated valve according to 6.   In the porous body, an end portion of the short side portion opposite to the long side portion side and an end portion of the long side portion opposite to the short side portion side are aligned and joined. The electrically operated valve according to claim 7. The motor-operated valve according to claim 7 or 8, wherein a portion of the long side portion that does not overlap with the short side portion is bonded and fixed to the valve seat member.

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