JP2014142073A - Motor valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and cost of a motor valve in which a bleeding port is formed between a valve element and an orifice in a closed state.SOLUTION: A motor valve is configured so that a bleeding port in which refrigerant of a minute flow volume circulates is formed between a valve element 17 and an orifice 12 in a state in which a stopped portion 172 abuts on a stopper portion 182 formed in a valve main body 110. An insertion hole 181 is larger in diameter than a fitting hole and a valve shaft 116, the stopper portion 182 is provided to face a first pipe 20 in a valve chamber 111, and a pressure equalizing passage 185 communicating an interior of a can 30 with the valve chamber 111 is formed in a portion of the insertion hole 181 closer to the first pipe 20 in a state in which the stopped portion 172 abuts on the stopper portion 182.

Description

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

  Conventionally, in order to control the flow rate of refrigerant in an air conditioner, an electric valve that controls the opening of an orifice by a motor has been used.

  In an air conditioner using a motorized valve, especially when dehumidifying operation is performed at midnight, it is not preferred by the user to generate an operation sound that repeatedly turns the motorized valve on and off. However, it is desirable to operate in a state where a small flow rate of refrigerant flows through the orifice.

  Patent Document 1 discloses a highly durable electric valve in which a bleed port is formed by a gap between a valve body and an orifice in a closed state, and the bleed port is not easily worn because the valve body does not contact the orifice. Yes. The invention described in Patent Document 1 will be described below.

  FIG. 5 is a longitudinal sectional view showing the entire electric valve of Patent Document 1, and FIG. 6 is an enlarged sectional view showing a main part of the electric valve shown in FIG.

  In FIG. 5, the motor-operated valve generally indicated by reference numeral 1 has a valve main body 10, in which a valve chamber 11 and an orifice 12 communicating with the valve chamber 11 are formed. Further, pipes 20 and 22 are connected to the valve body 10. The pipe 20 is connected to one side of the valve chamber 11 of the valve body 10, and is a refrigerant introduction pipe for introducing carbon dioxide (gas) or the like as a refrigerant into the valve chamber 11, and is connected below the valve chamber 11. The pipe 22 is a refrigerant outlet pipe. A drive mechanism 13 that opens and closes the valve is attached to the upper portion of the valve body 10.

  In the drive mechanism 13, a can 30, which is a cylindrical pressure vessel, is formed at a lower end 31 of a step group 23 a formed on a stainless steel bowl-shaped receiving member 23 fixed to the upper part of the valve body 10. It is attached to the upper part of the valve body 10 by being sealed and joined by butt welding. The can 30 is made of a non-magnetic metal plate such as stainless steel as a raw material and is formed into a bottomed cylindrical shape having a hemispherical nadir 32 by deep drawing or the like, and the inside is kept airtight. A stator unit 41 of a stepping motor 40 is provided outside the can 30, and a rotor unit 42 of the stepping motor 40 is rotatably arranged inside the can 30 with a predetermined gap α. Yes.

  The rotor unit 42 includes a rotor 43 made of a plastic magnet formed by mixing a magnetic material with a resin, and a screw feed member 45 having a cylindrical shape with a lower opening connected to the rotor 43 via a ring member 44. And. Examples of the material of the rotor 30 include Nd—Fe—B based rare earth plastic magnets. The screw feed member 45 also has a function as a valve shaft holder that holds a valve shaft 16 described later. In this embodiment, the ring member 44 is composed of a brass metal ring inserted when the rotor 43 is formed. The upper projecting portion of the screw feed member 45 is fixed to the ring member 44 by the caulking portion 46, whereby the rotor 43, the ring member 44, and the screw feed member 45 are integrally connected.

  The drive mechanism 13 moves the valve shaft 16 made of brass up and down in the valve body 10. A needle-like valve body 17 is formed at the lower end of the valve shaft 16. An opening that opens to the valve chamber 11 side of the orifice 12 is a valve port 15. When the valve body 17 approaches or retracts from the orifice 12 to open and close the valve port 15, the flow rate of the fluid (refrigerant) passing through the orifice 12 is controlled.

  The drive mechanism 13 further includes a cylindrical guide bush 47 into which the valve shaft 16 is slidably fitted. The screw feed member 45 is fitted on the outer periphery of the bush, and the screw is engaged. ing. The lower end 47a of the guide bush 47 is formed with a large diameter, and is press-fitted (or screwed) into the fitting hole 24 provided in the valve body 10. A male screw portion 48 is formed near the center of the guide bush 47. The screw feed member 45 is formed with a female screw portion (moving screw portion) 49 that is screwed into a male screw portion (fixed screw portion) 48 of the guide bush 47. The screw feeding member 45 and the guide bush 47 constitute conversion means for converting the rotation of the rotor 43 into the axial movement of the valve shaft 16.

  The upper small diameter portion 18 of the valve shaft 16 is inserted through the central portion of the nadir 50 of the screw feeding member 45. The upper end portion of the upper small-diameter portion 18 is press-fitted and fixed to a nut 19 as a regulating member placed on the top surface of the nadir of the screw feed member 45.

  The valve shaft 16 is always attached downward, that is, in the valve closing direction by a buffering coil spring 52 as a spring member that is compressed between the nadir 50 of the screw feed member 45 and the intermediate step portion 51 of the valve shaft 16. It is energized. The movement of the valve shaft 16 in the valve closing direction with respect to the screw feed member 45 is restricted by the nut 19 coming into contact with the screw feed member 45. On the top 50 of the screw feed member 45, a return spring 54 made of a coil spring is provided. The return spring 54 abuts against the inner surface of the can 30 when the fixing screw portion 48 of the guide bush 47 and the moving screw portion 49 of the screw feed member 45 are disengaged, and the fixing screw portion 48 and the moving screw portion 49. It works to restore the screwing.

  The stator unit 41 mounted on the can 30 includes a yoke 61 made of a magnetic material, upper and lower stator coils 63 and 63 wound around the yoke 61 via a bobbin 62, and a resin mold cover 66. .

  A lower stopper body (fixed stopper) 67 constituting one side of the stopper mechanism is fixed to the guide bush 47, and an upper stopper body (moving stopper) 68 constituting the other side of the stopper mechanism is fixed to the screw feed member 45. Yes.

  In FIG. 6, the valve shaft 16 has a locking portion 71 that locks with a stopper portion 70 formed in the valve body 10 at the valve closing position of the illustrated valve body 17 in the intermediate portion in the axial direction. . The valve body 17 forms a bleed port by forming a slight gap 72 between the valve body 17 and the orifice 12 at the valve closing position, and the valve body 17 does not contact the peripheral edge of the valve port 15. The valve body 17 allows a slight amount of fluid to flow through the gap 72 even in the fully closed position shown in the figure. Therefore, it is possible to secure a necessary refrigerant flow rate at the time of dehumidification, and to delay or alleviate the occurrence of large pressure fluctuations in the flow path, such as when the compressor of the refrigeration cycle is started, thereby reducing so-called initialization noise. be able to. Further, the stop position at which the valve shaft 16 abuts against the stopper portion 70 is a limit position where the valve shaft 16 is not further lowered (the base point of the vertical lift of the valve shaft), so the valve shaft 16 is further lowered from that position. Since the driving force of the stepping motor 40 is not required, an unnecessary load is not imposed on the stepping motor 40.

  In the valve body 10, the stopper portion 70 is formed through the wall portion 73 of the valve chamber 11 facing the opening of the orifice 12, and is formed at the end edge portion of the insertion hole 74 through which the valve shaft 16 is inserted. Further, the locking portion 71 of the valve shaft 16 is formed as a step on the peripheral surface of the valve shaft 16. By adopting such a structure for the stopper 70 and the locking portion 71, the stopper 70 and the locking portion 71 can be formed by simple machining such as cutting or forging, which contributes to reducing the manufacturing cost of the electric valve. A portion from the locking portion 71 of the valve shaft 16 to the valve body 17 is a tapered taper shaft portion 78 and does not interfere with the insertion hole 74 or the orifice 12.

  The orifice 12 is formed as a tapered hole that opens into the valve chamber 11 at the throat portion 75. Further, the valve body 17 includes a shaft-like portion 76 having the same cross section and a tapered portion 77 that is connected to the tip side of the shaft-like portion 76 and has a diameter reduced toward the tip. When the drive mechanism 13 drives the valve shaft 16 in the valve opening direction from the fully closed position by positioning the portion of the shaft-like portion 76 near the tapered portion 77 at the valve closing position of the valve body 17 in the throat portion 75, Since the tapered portion 77 of the body 17 is immediately separated from the throat portion 75 of the orifice 12, the responsiveness of the valve opening can be enhanced. A counterbore portion 79 having an annular shape is formed around the opening of the throat portion 75 of the orifice 12. By forming the counterbore portion 79 around the opening of the throat portion 75, burrs at the time of forming the throat portion 75 can be removed, the interference between the valve body 17 and the throat portion 75 can be prevented, and the smoothness of the valve body 17 can be prevented. It can contribute to opening and closing movement.

  In the motor-operated valve 1 configured as described above, the stepping motor 40 is driven in the drive mechanism 13, and the rotation of the stepping motor 40 is converted into the movement of the valve shaft 16 in the axial direction. Moves axially within the valve body 10. The flow rate of the refrigerant passing through the orifice 12 can be controlled by changing the opening amount of the valve port 15 of the orifice 12 by the valve body 17 provided at the tip of the valve shaft 16 approaching or retreating with respect to the orifice 12. That is, when the stator coils 63 and 63 are energized in one direction, the rotor 43 and the screw feed member 45 are rotated in one direction with respect to the guide bush 47 fixed to the valve body 10, and the guide bush 47 For example, the screw feed member 45 moves downward by screw feed between the fixed screw portion 48 and the moving screw portion 49 of the screw feed member 45. The downward movement of the screw feed member 45 lowers the valve shaft 16 via the coil spring 52, so that the valve body 17 enters the orifice 12 and the valve port 15 is substantially closed. A gap 72 exists between the valve element 17 and the orifice 12 to form a bleed port, and a slight amount of fluid can flow through the gap 72 even in a so-called valve closing state.

  When the stopper 70 is locked to the locking portion 71 and the valve port 15 is closed, the upper stopper body 67 is not yet in contact with the lower stopper body 68 and the valve body 17 remains closed. The rotor 43 and the screw feed member 45 further rotate down. At this time, since the screw feed member 45 is lowered with respect to the valve shaft 16, the downward force of the screw feed member 45 is absorbed by compressing the coil spring 52 for collision. After that, when the rotor 43 further rotates and the screw feed member 45 is lowered, the upper stopper body 67 comes into contact with the lower stopper body 68, and the screw feed member 45 is not lowered even if the stator coils 63 and 63 are energized. It is forcibly stopped. Thereby, the rotation base point of the stepping motor is given. Further, since the stopper bodies 67 and 68 come into contact with each other while being buffered by the coil spring 52, they are not easily worn and have high durability.

  On the other hand, when the stator coils 63 and 63 are energized in the other direction, the rotor 43 and the screw feed member 45 are rotated in the opposite direction to the guide bush 47 fixed to the valve body 10. The screw feed member 45 moves upward by screw feed between the fixed screw portion 48 of the guide bush 47 and the moving screw portion 49 of the screw feed member 45. The valve body 17 at the lower end of the valve shaft 16 is separated from the orifice 12, the valve port 15 is opened, and the refrigerant passes through the valve port 15. In this case, the effective opening area of the valve port 15, that is, the flow rate of the refrigerant can be adjusted by the rotation amount of the rotor 30. Since the rotation amount of the rotor 30 is controlled by the number of pulses, the refrigerant passing flow rate can be adjusted with high accuracy.

JP 2007-205565 A

  In order to stabilize the valve operation, the conventional motor-operated valve is provided with a pressure equalizing hole 90 communicating with the inside of the can 30 and the valve chamber 11 in addition to the insertion hole 74 in the valve body 10. In order to further stabilize the valve operation, it may be necessary to provide two pressure equalizing holes.

  For this reason, a space for forming the pressure equalizing hole 90 around the insertion hole 74 must be secured, and the valve chamber 11 communicating with the pressure equalizing hole 90 needs to be enlarged. It will be an obstacle. Further, since the pressure equalizing hole 90 and the insertion hole 74 are not coaxial, when the valve body 10 is machined with a lathe, the insertion hole 74 is formed, and then the valve body 10 is chucked again to form the pressure equalizing hole 90. Since it is processed, the processing man-hours are increased and the cost is high.

  The present invention has been made in view of the above problems, and is an electric valve in which a bleed port is formed between a valve body and an orifice in a valve-closed state, and an object thereof is to reduce the size and cost. To do.

  In order to achieve the above object, an electric valve according to the present invention includes a valve body, an orifice communicating with the valve chamber, a valve body provided opposite to the orifice and communicating with the valve chamber, and the valve body. A first pipe connected to one side of the valve chamber; a second pipe connected to the valve main body and connected to the lower side of the valve chamber; And a guide bush having a fitting insertion hole provided coaxially with the insertion hole, a valve body penetrating the fitting insertion hole and the insertion hole and entering the orifice, and a locking portion above the valve body. A valve shaft, and a can that is attached to the valve body and houses a drive mechanism that drives the valve shaft, and the valve body in a state in which the locking portion is in contact with a stopper portion formed in the valve body. A very small amount of refrigerant flows between the orifices. The electrically operated valve is formed with a bleed port to be formed, wherein the insertion hole is larger in diameter than the fitting insertion hole and the valve shaft, and the stopper portion is opposed to the first pipe in the valve chamber. In the state where the locking portion is in contact with the stopper portion, a pressure equalizing passage for communicating the inside of the can and the valve chamber is formed in the first piping side portion of the insertion hole. It is characterized by that.

  According to the present invention, in the motor-operated valve in which the bleed port is formed between the valve body and the orifice in the valve-closed state, it is possible to reduce the size and the cost.

It is sectional drawing which expands and shows the principal part of the motor operated valve of 1st Embodiment. It is sectional drawing which expands and shows the principal part of the motor operated valve of 2nd Embodiment. It is sectional drawing which expands and shows the principal part of the motor operated valve of 3rd Embodiment. It is AA sectional drawing of the valve shaft in FIG. It is a longitudinal cross-sectional view which shows the whole electrically operated valve of patent document 1. FIG. It is sectional drawing which expands and shows the principal part of the motor operated valve shown in FIG.

  A mode for carrying out the present invention will be described.

  FIG. 1 is an enlarged cross-sectional view showing a main part of the motor-operated valve according to the first embodiment. In the following embodiments, the same parts as those of the conventional motor-operated valve described in FIGS. 5 and 6 are denoted by the same reference numerals, and the parts different from those of the conventional motor-operated valve described in FIGS.

  The valve shaft 116 includes an insertion shaft portion 95 that is inserted into the guide bush 47 and an insertion shaft portion 171 that is formed on the distal end side of the insertion shaft portion 95 and is inserted into the insertion hole 181 of the valve body 110. Yes. Further, a locking portion 172 is provided on the distal end side of the insertion shaft portion 171, and a reduced diameter shaft portion 173 is provided on the distal end side of the locking portion 172. The same needle-like valve element 17 as that of the conventional example is formed on the distal end side of the reduced diameter shaft portion 173 via a taper portion 174.

  The valve main body 110 has a valve chamber 111, and a wall portion 190 is formed on the upper side (can 30 side) of the valve chamber 111. The wall portion 190 has an insertion hole 181. The size of the insertion hole 181 is larger than the insertion shaft portion 171 so as to form a space that becomes the pressure equalizing hole 185. Further, the back of the valve chamber 111 is a back wall portion 183, and a stopper portion 182 is provided on the top thereof. In addition, a counterbore 79 is provided in the lower part of the valve chamber as in the conventional example. The diameter of the spot facing 79 is smaller than the diameter of the insertion hole 181.

  Next, a method for processing the valve body 110 will be described. Since the insertion hole 181, the back wall 183, and the counterbore portion 79 are coaxially positioned, the insertion hole 181, the back wall portion 183, and the counterbore portion 79 can be formed by cutting without changing the chuck from the vertical direction (the fitting hole 24 side) using a lathe. The stopper portion 182 is formed by a step portion between the back wall portion 183 and the insertion hole 181. Moreover, since the valve chamber 111 can be formed by cutting from the horizontal direction and the depth is formed by vertical processing, the valve chamber 111 may be processed until it reaches it. The order of processing in the horizontal direction and the vertical direction may be any one.

  Next, the operation will be described. When the valve shaft 116 descends toward the orifice 12 (in the valve closing direction), the locking portion 172 of the valve shaft 116 comes into contact with the stopper portion 182 of the valve body 110 and the valve shaft 116 stops. At this time, the valve body 17 forms a bleed port by forming a slight gap 72 between the valve body 17 and the orifice 12 at the valve closing position, and the valve body 17 does not contact the peripheral portion of the valve port 15. For this reason, a very small amount of refrigerant flows. On the other hand, since a space is formed between the insertion shaft portion 171 of the valve shaft 116 and the insertion hole 181 of the coaxial valve body 110, the space on the opposite side of the stopper portion 182 is a pressure equalizing passage. 185, the can 30 side (the fitting hole 24 side) communicates with the valve chamber 111, and the valve operation can be stabilized without causing a pressure difference therebetween. Thus, by forming the pressure equalizing passage 185 between the outer peripheral surface of the valve shaft 116 and the inner peripheral surface of the insertion hole 181, compared to the case where the pressure equalizing hole is formed separately from the insertion hole as in the prior art. In addition to reducing the size of the motor-operated valve, it is not necessary to re-chuck the valve body 110, thereby reducing man-hours and costs.

  FIG. 2 is an enlarged cross-sectional view illustrating a main part of the motor-operated valve according to the second embodiment.

  The valve shaft 16 is the same as the conventional example described with reference to FIGS.

  The valve body 210 has the valve chamber 11, and an insertion hole 280 is formed in the wall portion 290 on the upper side (can 30 side) of the valve chamber 11. The insertion hole 280 has an expanded portion 281 that protrudes radially outward in a part of the circumferential direction, and the portion of the expanded portion 281 becomes a pressure equalizing passage. The upper part on the side not having the expansion part 281 becomes a stopper part 282 and is engaged with the engagement part 71 of the valve shaft 16. The expansion part 281 can be processed by moving the milling machine in the lateral direction, for example. Note that the extended portion 281 may be a notch.

  Next, the operation will be described. When the valve shaft 16 descends toward the orifice 12 (in the valve closing direction), the locking portion 71 of the valve shaft 16 comes into contact with the stopper portion 282 of the valve main body 210 and stops. At this time, the valve body 17 forms a bleed port by forming a slight gap 72 between the valve body 17 and the orifice 12 at the valve closing position, and the valve body 17 does not contact the peripheral portion of the valve port 15. For this reason, a very small amount of refrigerant flows. On the other hand, since the pressure equalizing passage is formed by the extended portion 281 formed in the insertion hole 280, the inside of the can 30 and the valve chamber 11 communicate with each other, and the valve operation is stabilized without causing a pressure difference therebetween. Can be achieved. Thus, by forming the pressure equalizing passage 185 between the outer peripheral surface of the valve shaft 16 and the inner peripheral surface of the insertion hole 181, compared to the case where the pressure equalizing hole is formed separately from the insertion hole as in the prior art. The motorized valve can be downsized.

  FIG. 3 is an enlarged cross-sectional view showing a main part of the third embodiment. FIG. 4 is a cross-sectional view taken along the line AA of the valve shaft in FIG.

  The valve main body 310 is different from the valve main body 10 described with reference to FIGS. 5 and 6 in that the pressure equalizing hole 90 is not provided, but the other shapes are the same.

  The valve shaft 316 has a cut portion 372 formed by cutting a part including the locking portion 71 of the valve shaft 16 parallel to the axis with the valve shaft 16 described in FIGS. Different. The cut portion 372 is inserted from the tapered portion 373 so as to form a pressure equalizing passage 385 in the insertion hole 74 in a state where the locking portion 371 of the valve shaft 316 is in contact with the stopper portion 70 of the valve body 310. A portion 95 is provided. As shown in FIG. 4, the cut portion 372 is processed so that a part of the cylindrical valve shaft 316 inserted in the insertion hole 74 in the circumferential direction is cut into a D-shaped cross section.

  Next, the operation will be described. When the valve shaft 316 descends toward the orifice 12 (in the valve closing direction), the locking portion 371 of the valve shaft 316 comes into contact with the stopper portion 70 of the valve main body 310 and stops. At this time, the valve body 17 forms a bleed port by forming a slight gap 72 between the valve body 17 and the orifice 12 at the valve closing position, and the valve body 17 does not contact the peripheral portion of the valve port 15. For this reason, a very small amount of refrigerant flows. On the other hand, since a space is formed between the cut portion 372 and the insertion hole 74, this becomes a pressure equalizing passage 385, which communicates the inside of the can 30 and the valve chamber 11, and creates a pressure difference therebetween. Therefore, stable valve operation can be achieved. Thus, by forming the pressure equalizing passage 385 between the outer peripheral surface of the valve shaft 316 and the inner peripheral surface of the insertion hole 181, compared to the case where the pressure equalizing hole is formed separately from the insertion hole as in the prior art. The motorized valve can be downsized.

DESCRIPTION OF SYMBOLS 1 Motorized valve 10 Valve body 11 Valve chamber 12 Orifice 30 Can 47 Guide bush 70 Stopper part 71 Locking part 72 Gap 73 Wall part 74 Insertion hole 75 Throat part 76 Shaft part 77 Tapered part 78 Taper shaft part 79 Counterbore part 90 Pressure equalizing hole 95 Insertion shaft portion 171 Insertion shaft portion 181 Insertion hole 182 Stopper portion 281 Expansion portion 372 Cut portion

Claims (1)

A valve body, an orifice communicating with the valve chamber, and a valve body provided opposite to the orifice and having an insertion hole communicating with the valve chamber;
A first pipe provided in the valve body and connected to one side of the valve chamber;
A second pipe provided in the valve body and connected to the lower side of the valve chamber;
A guide bush provided in the valve body and having a fitting insertion hole provided coaxially with the orifice and the insertion hole;
A valve shaft that penetrates the fitting insertion hole and the insertion hole and enters the orifice, and a valve shaft having a locking portion above the valve body;
A can that is attached to the valve body and houses a drive mechanism that drives the valve shaft;
The motor-operated valve is configured such that a bleed port is formed between the valve body and the orifice to allow a small flow rate of refrigerant to flow while the locking portion is in contact with a stopper portion formed on the valve body. And
The insertion hole is larger in diameter than the fitting insertion hole and the valve shaft,
The stopper portion is provided to face the first pipe in the valve chamber,
A pressure equalizing passage for communicating the inside of the can and the valve chamber is formed in a portion on the first piping side of the insertion hole in a state where the locking portion is in contact with the stopper portion. valve.

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