JP2013217408A - Motor-operated valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor-operated valve capable of controlling with high accuracy a flow rate when a small flow rate circulates, decreasing a pressure loss more when a large flow rate circulates, changing a flow direction promptly and stably, and improving reliability without causing valve body enlargement.SOLUTION: Check-valve valving elements 75 as three balls are each arranged to close check valve ports 72B and 72C during normal flow and open them during reverse flow. Guide columns 73A and 73B as guide means for enabling the check-valve valving elements 75 to open and close the check valve ports 72B and 72C surely and smoothly are provided protrusively downward from a ceiling 21a of a valve chamber 21 to a predetermined height position above a valve seat body 16. A circulation gap H is formed between the lower end surfaces of the guide columns 73A and 73B and an upper surface of the valve seat body 16.

Description

  The present invention relates to an electric valve used by being incorporated in a heat pump type air conditioning system or the like, and in particular, the flow rate can be controlled with high accuracy during normal flow (when flowing a small flow rate), and during reverse flow (when flowing a large flow rate). ) Relates to a motor-operated valve capable of reducing pressure loss as much as possible.

  FIG. 8 shows an example of a heat pump type air conditioning system. This cooling / heating system 100 is usually provided with a compressor 101, a flow path switch 102, an outdoor heat exchanger (condenser) 103, an indoor heat exchanger (evaporator) 104, and in order to improve energy saving efficiency and the like. There are two expansion valves (distributors etc. are not shown). That is, the first expansion valve 105 is disposed near the outdoor heat exchanger 103, and the second expansion valve 106 is disposed near the indoor heat exchanger 104. As the expansion valves 105 and 106, temperature-sensitive (mechanical) type valves are used. Further, in order to reduce the pressure loss as much as possible, the first and second check valves 108 and 109 are arranged in parallel with the first and second expansion valves 105 and 106.

  In the cooling / heating system 100, during cooling, the refrigerant gas compressed by the compressor 101 is introduced into the outdoor heat exchanger 103 from a flow path switch 102 formed of, for example, a four-way valve, as indicated by a solid arrow in the figure. Here, heat is exchanged with the outside air to condense, and the condensed refrigerant passes through the first check valve 108 (bypassing the first expansion valve 105) and flows into the second expansion valve 106, where After adiabatic expansion, the refrigerant flows into the evaporator 104, evaporates by exchanging heat with room air in the evaporator 104, and cools the room.

  On the other hand, at the time of heating, the refrigerant gas compressed by the compressor 101 is introduced from the flow path switch 102 to the indoor heat exchanger 104 and exchanges heat with the indoor air, as indicated by broken line arrows in the figure. After condensing and heating the room, it passes through the second check valve 109 (bypassing the second expansion valve 106) and flows into the first expansion valve 105, where it is depressurized and then passed through the distributor. Then, it is introduced into the outdoor heat exchanger 103, where it evaporates and returns to the compressor 101.

  As described above, in the cooling / heating system 100, during normal flow (cooling), the refrigerant is guided to the second expansion valve 106 through the first check valve 108 without passing through the first expansion valve 105, and this second expansion valve 106. In the reverse flow (heating), the refrigerant is guided to the first expansion valve 105 through the second check valve 109 without passing through the second expansion valve 106, and the flow rate is adjusted by the first expansion valve 105. By adjusting the check valves 108 and 109 in parallel with the expansion valves 105 and 106, the pressure loss is reduced as much as possible.

  Incidentally, in recent years, in the cooling / heating system 100 as described above, in order to further improve the energy saving efficiency and the like, instead of the temperature-sensitive (mechanical) expansion valves 105 and 106, the lift amount, that is, the effectiveness of the valve port is effective. The use of an electronically controlled motor-operated valve that can arbitrarily control the opening area has been studied.

  Hereinafter, an example of the electronically controlled motor-operated valve will be described with reference to FIG. The illustrated motor-operated valve 10 'has a lower large-diameter portion 25a and an upper small-diameter portion 25b, a valve shaft 25 in which a valve body 24 is integrally provided at a lower end portion of the lower large-diameter portion 25a, and the valve body. A valve body 15 having a valve chamber 23 to which a first inlet / outlet 11 and a second inlet / outlet 12 made of a conduit (joint) are connected; A can 40 whose lower end is sealed and welded to the valve main body 15 via an annular connector 44, a rotor 30 disposed with a predetermined gap α on the inner periphery of the can 40, and A stator 50A externally fitted to the can 40 to rotationally drive the rotor 30, and the rotor 30 and the valve body 24 are disposed between the rotor 30 and the valve body 24. A screw feed mechanism that contacts and separates from the valve port 23; So as to control the flow rate through the refrigerant by changing the lift amount of the valve element 24 against the serial valve port 23.

  The stator 50A includes a yoke 51, a bobbin 52, stator coils 53 and 53, a resin mold cover 56, and the like. A stepping motor 50 is configured by the rotor 30, the stator 50A, and the like. Thus, an elevating drive mechanism for adjusting the lift amount of the valve body 24 with respect to the valve port 23 is configured.

  A support ring 36 is integrally coupled to the rotor 30, and a cylindrical valve shaft holder 32 is formed on the support ring 36 at a lower opening disposed on the outer periphery of the valve shaft 25 and the guide bush 26. The upper protrusion is caulked and fixed, whereby the rotor 30, the support ring 36, and the valve shaft holder 32 are integrally connected.

  The screw feed mechanism has a lower end portion 26a press-fitted and fixed to the valve body 15, and a valve shaft 25 (a lower large-diameter portion 25a thereof) is slidably inserted on the outer periphery of a cylindrical guide bush 26. The formed fixed screw portion (male screw portion) 28 and a moving screw portion (female screw portion) 38 formed on the inner periphery of the valve shaft holder 32 and screwed into the fixed screw portion 28 are configured. .

  The upper small diameter portion 26b of the guide bush 26 is inserted into the upper portion of the valve shaft holder 32, and the upper small diameter portion of the valve shaft 25 is formed at the center of the ceiling portion 32a of the valve shaft holder 32 (through hole formed therein). 25b is inserted. A push nut 33 is press-fitted and fixed to the upper end portion of the upper small diameter portion 25 b of the valve shaft 25.

  The valve shaft 25 is extrapolated to the upper small-diameter portion 25b of the valve shaft 25, and between the ceiling portion 32a of the valve shaft holder 32 and the upper terrace surface of the lower large-diameter portion 25a of the valve shaft 25. The valve closing spring 34 composed of a compressed compression coil spring is always urged downward (in the valve closing direction). A return spring 35 made of a coil spring is provided on the outer periphery of the push nut 33 on the ceiling portion 32 a of the valve shaft holder 32.

  The guide bush 26 has a lower stopper body (fixed stopper) that constitutes one of rotation lowering stopper mechanisms for preventing further rotation lowering when the rotor 30 is rotated and lowered to a predetermined valve closing position. 27 is fixed, and an upper stopper body (moving stopper) 37 constituting the other of the stopper mechanism is fixed to the valve shaft holder 32.

  The valve closing spring 34 is used to obtain a required sealing pressure in a closed state where the valve body 24 is seated on the valve port 23 (to prevent leakage), and when the valve body 24 comes into contact with the valve port 23. Deployed to mitigate impact.

  In the motor-operated valve 10 ′ configured as described above, the rotor 30 is made to the guide bush 26 fixed to the valve body 15 by supplying energization excitation pulses to the stator coils 53, 53 in the first mode. The valve shaft holder 32 is rotated in one direction, and, for example, the valve shaft holder 32 is moved downward by the screw feed between the fixing screw portion 28 of the guide bush 26 and the moving screw portion 38 of the valve shaft holder 32, so that the valve body. 24 is pressed against the valve port 23 (valve seat 23a) to close the valve port 23 (fully closed state).

  When the valve port 23 is closed, the upper stopper body 37 is not yet in contact with the lower stopper body 27, and the rotor 30 and the valve shaft holder 32 are further rotated and lowered while the valve body 24 remains closed. . In this case, the valve shaft 25 (valve body 24) does not descend, but the valve shaft holder 32 descends, so that the valve closing spring 34 is compressed by a predetermined amount, and as a result, the valve body 24 is strongly pressed against the valve port 23. At the same time, when the valve shaft holder 32 is rotated and lowered, the upper stopper body 37 comes into contact with the lower stopper body 27 and then the rotation and lowering of the valve shaft holder 32 is forcibly stopped even if the pulse supply to the stator coils 53 and 53 is continued. Is done.

  On the other hand, when the energization excitation pulse is supplied to the stator coils 53, 53 in the second mode, the rotor 30 and the valve shaft holder 32 are rotated in the opposite direction to the guide bush 26 fixed to the valve body 15, and the guides are guided. Due to the screw feed between the fixing screw portion 28 of the bush 26 and the moving screw portion 38 of the valve shaft holder 32, the valve shaft holder 32 is now moved upward. In this case, since the valve closing spring 34 is compressed by a predetermined amount as described above at the time when the rotation of the valve shaft holder 32 starts to rise (when pulse supply starts), until the valve closing spring 34 is extended by the predetermined amount. The valve body 24 does not leave the valve port 23 and remains in the closed state (lift amount = 0). Then, after the valve closing spring 34 is extended by the predetermined amount, when the valve shaft holder 32 is further rotated up, the valve body 24 is separated from the valve port 23, the valve port 23 is opened, and the refrigerant is supplied to the valve port 23. Pass through. In this case, the lift amount of the valve body 24, in other words, the effective opening area of the valve port 23 can be arbitrarily finely adjusted by the rotation amount of the rotor 30, and the rotation amount of the rotor 30 is controlled by the number of supplied pulses. The refrigerant flow rate can be controlled with high accuracy (for details, refer to Patent Documents 1 and 2).

  However, even when the motor-operated valve 10 'as described above is employed in the air conditioning system 100, there are the following problems to be improved. That is, in the cooling / heating system 100, during normal flow (cooling), the refrigerant is guided to the second expansion valve 106 through the first check valve 108 without passing through the first expansion valve 105, and the second expansion valve 106 The flow rate is adjusted, and during reverse flow (heating), the refrigerant is guided to the first expansion valve 105 through the second check valve 109 without passing through the second expansion valve 106, and the flow rate is adjusted by the first expansion valve 105. Therefore, it is indispensable to incorporate the check valves 108 and 109 in parallel with the expansion valves 105 and 106. However, incorporating two check valves in the refrigerant circuit is equivalent to the joints. The number of parts such as these increases, and the pipe connection work takes extra time and effort.

  Therefore, Patent Document 2 discloses a motor-operated valve having both functions of the above-described expansion valve and check valve, that is, when the refrigerant is flowed in one direction (at the time of normal flow = at the time of small flow rate flow), flow control is performed. As much as possible, the lift amount (effective opening area) is finely controlled within a specific range below a predetermined value, and when the refrigerant is flowing in the other direction (reverse flow = high flow rate), pressure loss is reduced as much as possible. A device that maximizes the lift amount (effective opening area) has been proposed.

  However, in the proposed motor-operated valve, there is a problem that if the diameter of the valve port is increased in order to reduce the pressure loss at the time of a large flow rate, the flow control cannot be performed with high accuracy at the time of a small flow rate.

  On the other hand, a valve shaft having a needle-type main valve body, as described in Patent Document 3, in order to achieve both a reduction in pressure loss during a large flow rate and an improvement in flow rate control accuracy during a small flow rate, A valve body having a valve seat in which a main valve port (orifice) that is opened and closed by the main valve body is formed, and a lift drive for adjusting an effective opening area (lift amount of the main valve body portion) of the main valve port A motor is provided as a means, and fluid flows only from between the main valve body and the main valve port in order to control the flow rate with high accuracy when a small flow rate is distributed, and pressure loss is minimized when flowing a large flow rate. Therefore, there has been proposed a motor-operated valve configured to flow all or most of the fluid without passing through the main valve port.

  In more detail, the motor-operated valve has a large flow rate channel that bypasses the main valve port, and closes the large flow rate channel when the small flow rate is flowing (positive flow). A check valve body that opens at the time of circulation (at the time of reverse flow) is an electric valve with a check valve disposed on the opposite side of the main valve body portion with the main valve seat interposed therebetween (Patent Document 3). 1 and 2 of the first embodiment). This electric valve can be said to be a bidirectional flow type electric valve.

Japanese Patent Laid-Open No. 2001-50415 JP 2009-14056 A JP 2010-249246 A

  In the motor valve with a check valve proposed above, flow control is performed only with a needle-type main valve body part when a small flow rate is distributed, and when the flow rate is large, the check valve body has a large flow path (bypass flow path). Since it is designed to open automatically, it is possible to improve both flow control accuracy during low flow and reduce pressure loss during high flow, but the check valve body sandwiches the main valve seat. Because it is arranged on the side opposite to the main valve body (on the side of the valve chamber), it tends to increase the valve body size, complicate the internal structure of the valve seat, etc., and increase the processing and assembly costs. The effect is an issue.

  The present invention has been made in view of such circumstances, and its purpose is to increase the size of the valve body, complicate the internal structure of the valve seat, etc., increase the processing assembly cost, etc. It is an object of the present invention to provide a cost-effective motor-operated valve that can control the flow rate with high accuracy when flowing a small flow rate, and can flow a fluid so that pressure loss does not occur as much as possible when flowing a large flow rate. It is another object of the present invention to provide a motor-operated valve that has a simple configuration, can change the flow direction quickly and stably, can stably operate, and can improve reliability.

  In order to achieve the above object, the motor-operated valve according to the present invention basically includes a valve body provided with a first inlet / outlet, a valve chamber, and a second inlet / outlet, and a valve constituting a small flow rate channel. A valve seat body having a main valve port provided between the valve chamber and the second inlet / outlet in the valve body, and the second inlet / outlet from the valve chamber via the main valve port. A valve shaft having a needle-type valve element disposed in the valve chamber and a motor for raising and lowering the valve shaft.

  In the valve body, there is formed a flow passage for large flow rate that bypasses the main valve port, and a float type check valve body that closes the flow passage for large flow rate during normal flow and opens during reverse flow. The large flow path has at least one check valve port provided in the valve chamber, the check valve bodies are provided in the same number as the check valve ports, and the check valve is the check valve. A guide means is provided in the valve chamber so as to open and close the valve opening, and a guide column as the guide means projects downward from a ceiling portion of the valve chamber to a predetermined height position on the valve seat body, A flow gap is formed between the lower end surface of the guide column and the upper surface of the valve seat body.

In a preferred embodiment, a part of the guide means is constituted by an inner peripheral wall surface of the valve chamber.
In a preferred embodiment, the check valve port is formed on the outer peripheral side of the main valve port.

The check valve body is preferably composed of a sphere or a columnar body whose lower end closes the check valve port.
The valve seat body is preferably formed integrally with the valve body.

  In the motor-operated valve according to the present invention, a flow rate check valve body that forms a flow passage for large flow rate that bypasses the main valve port and closes the flow passage for large flow rate during normal flow and opens during reverse flow is a valve. Because it is installed in the chamber, the flow rate can be controlled with high accuracy when the flow rate is small, without increasing the size of the valve body, complicating the internal structure of the valve seat, etc., and increasing the processing and assembly costs. It is possible to flow the fluid so as not to cause pressure loss as much as possible at the time of distribution, and it is excellent in cost effectiveness.

  In addition to the above, a guide column as a guide means for reliably and smoothly opening and closing the check valve opening by each check valve body is downward from the ceiling of the valve chamber to a predetermined height position on the valve seat body. Since it is projecting and a flow gap is formed between the lower end surface of this guide column and the upper surface of the valve seat body, the flow of fluid is not so hindered during reverse flow, and pressure loss during reverse flow is reduced. It can be effectively reduced.

The partial notch sectional drawing with which the structure of one Example of the motor operated valve which concerns on this invention and operation | movement description at the time of a normal flow are provided. The partial notch sectional drawing with which the structure of one Example of the motor operated valve concerning this invention and operation | movement description at the time of a reverse flow are provided. The perspective view of the state which fractured | ruptured the principal part of FIG. 2 which shows the time of a reverse flow. (A) is sectional drawing which follows the XX arrow line of FIG. 2 generally, (B) is sectional drawing which follows the YY arrow line of FIG. The perspective view which shows an example of the guide pillar of the electrically operated valve shown by FIG. 1, and the lid-like member provided with it. The perspective view which shows the other example of the guide pillar of the electrically operated valve shown by FIG. 1, and the lid-like member provided with it. Sectional drawing corresponding to FIG.4 (B) at the time of using what is shown by FIG. 6 as a guide pillar. The block diagram which shows an example of the conventional heat pump type | formula air conditioning system. The longitudinal cross-sectional view which shows an example of the conventional motor operated valve.

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

  1 and 2 are partial cutaway cross-sectional views of the main part of one embodiment of the motor-operated valve according to the present invention. FIG. 1 shows a normal flow (when a small flow rate is flowing), and FIG. 2 shows a reverse flow (a large flow rate). During distribution). In the present embodiment, the flow direction of the fluid (refrigerant) is the first inlet / outlet 11 → the second inlet / outlet 12 is the normal flow (FIG. 1), and the second inlet / outlet 12 → the first inlet / outlet 11 is the case. This is called reverse flow (FIG. 2). FIG. 3 is a partially cutaway perspective view (during reverse flow) of the main part (valve body).

  Further, the basic configuration of the stepping motor 50, the valve shaft 25, etc. of the motor-operated valve 10 in the illustrated embodiment is substantially the same as that of the motor-operated valve 10 ′ of the conventional example shown in FIG. 9 described above. The parts corresponding to the respective parts of the conventional motor-operated valve 10 'shown in the figure are denoted by the same reference numerals and redundant description is omitted, and the following mainly focuses on the main part of the valve body 15 (characteristic part). To do.

  The valve body 15 of the present embodiment has a valve seat body (partition wall) in which a first inlet / outlet 11, a valve chamber 21 in which the first inlet / outlet opens, and a main valve port 23 are sequentially formed in the positive flow direction. 16), a lower space 22 having the valve seat body 16 as a ceiling, and a second inlet / outlet 12 connected to the lower space 22 are provided.

  More specifically, the valve body 15 is attached by welding with a bottomed cylindrical base portion 15A having an open upper surface, and being attached and fitted to the upper portion of the base portion 15A in a circumferentially positioned state. And a lid-like member 15B.

  A thick disc-like valve seat body 16 that divides the inside of the base body portion 15A up and down is integrally provided below the base body portion 15A, and a space between the valve seat body 16 and the lid-like member 15B is connected to the valve chamber 21. The space between the bottom of the base portion 15 </ b> A and the valve seat body 16 is a lower space 22. Here, the lower end portion of the lid-like member 15 </ b> B becomes the ceiling portion 21 a of the valve chamber 21, and the upper surface of the valve seat body 16 becomes the bottom surface of the valve chamber 21. In the illustrated example, the valve seat body 16 is formed integrally with the valve body 15, but may be separate from the valve body 15.

  A main valve port 23 that is opened and closed by a needle-type valve body portion 24 provided at the lower end portion of the valve rod 25 is formed in the central portion of the valve seat body 16. Are formed with three circular check valve ports 72A, 72B, 72C in order to form a flow passage for large flow rate that bypasses the main valve port 23.

  The three check valve ports 72A, 72B, 72C are the same with the center axis of the main valve port 23 (rotation axis O of the valve rod 25) as the center, as can be understood by referring to FIG. The check valve ports 72 </ b> A and 72 </ b> B are arranged symmetrically around the center line C near the first inlet / outlet 11, and the check valve port 72 </ b> C is the first inlet / outlet 11. Is arranged on the center line C on the opposite side.

  Three float-type check valves made up of balls (spheres) are configured to close the large flow rate flow path including the three check valve ports 72A, 72B, 72C during normal flow and open during reverse flow. The valve bodies 75, 75, 75 are provided on the check valve ports 72A, 72B, 72C in the valve chamber 21, respectively.

  In this embodiment, the guide pillars 73A, 73B, 73C as guide means for reliably and smoothly opening and closing the check valve ports 72A, 72B, 72C by the check valve bodies 75 made of balls are used as the valve. It protrudes downward from the ceiling 21 a of the chamber 21 to a predetermined height position on the valve seat body 16, and a flow gap H is formed between the lower end surfaces of the guide pillars 73 A, 73 B, 73 C and the upper surface of the valve seat body 16. (See FIGS. 1 and 2). The guide columns 73A, 73B, 73C are formed so as to draw an arc (fan shape) centered on the central axis of the main valve port 23, and the side surfaces (both ends of the arc) of the adjacent guide columns. Each check valve body 75 is slidably guided in the vertical direction by the inner peripheral wall surface 21c of the valve chamber.

  More specifically, as can be understood by referring to FIG. 4 (B) in addition to FIGS. 1 to 3, between the check valve ports 72 </ b> A and 72 </ b> B, that is, the opening face of the first inlet / outlet 11. Is provided with a relatively wide cross-sectional fan-shaped guide column 73A, and a relatively narrow width between the check valve ports 72B and 72C and between the check valve ports 72C and 72A. Guide pillars 73B and 73C having a cross-sectional fan shape are arranged.

  On the base end side (ceiling part 21a side) of each of the guide pillars 73A, 73B, 73C, a reinforcing part 73d having a fan-shaped cross section is provided so as to increase the thickness in the radial direction. Both side surfaces of the guide columns 73A, 73B, 73C are formed as cylindrical surfaces having a slightly larger diameter than the check valve body 75 made of a ball, and the inner surfaces of the guide columns 73A, 73B, 73C are the lid-like member 15B. A part of the insertion hole 19 of the valve rod 25 that vertically passes through the central part of the valve rod 25 is formed. In addition, this reinforcement part 73d does not need to be provided in particular.

  Therefore, the check valve body 75 made of a ball is restricted in movement in the radial direction by the side surfaces of the adjacent guide columns (72A-72B), (72B-72C), (72C-72A) in the circumferential direction. The movement on the side is regulated by the inner side of the side surfaces of the guide pillars 73A, 73B, 73C, or by the inner side of the side and the valve rod 25, and the outer side in the radial direction is the inner wall surface 21c of the valve chamber 21. That movement is regulated. In other words, in this embodiment, the guide pillars (72A-72B), (72B-72C) adjacent to the valve shaft 25 and the inner peripheral wall surface 21c of the valve chamber 21 on the check valve ports 72A, 72B, 72C, (72C-72A) are defined, and each check valve body 75 moves up and down in accordance with the flow direction of the fluid without jumping out from each of the columnar spaces. The check valve ports 72A, 72B, and 72C are closed tightly by the fluid from the first inlet / outlet 11 when flowing, and the check valve ports 72A, 72B, and 72C are tightly closed during the reverse flow, and the ceiling of the valve chamber 21 by the fluid from the second inlet / outlet 12 The check valve ports 72A, 72B, 72C are fully opened by being pushed up until they contact 21a.

  As described above, in this embodiment, the guide for causing the inner peripheral wall surface 21c of the valve chamber 21 to open and close the check valve ports 72A, 72B, 72C by the check valve bodies 75 reliably and smoothly. Since it is used as a part of the means, the check valve port and the check valve body are not arranged on the side where the first inlet / outlet 11 is open. Therefore, a relatively wide cross-sectional fan-shaped guide column 73A is disposed on the opposite side of the opening surface of the first inlet / outlet 11, and the angular interval between the check valve ports 72A and 72B is set wide, for example, 150 to 180 degrees. In contrast, the angle interval between the check valve ports 72B and 72C and the angle interval between the check valve ports 72C and 72A are set to be narrow, for example, 90 to 110 degrees.

  The flow gap H formed between the lower end surfaces of the guide pillars 73A, 73B, 73C and the upper surface of the valve seat body 16 is preferably larger in view of the pressure loss during reverse flow. Since a large gap is formed between the check valve body 75 made of balls and the guide pillars 73A, 73B, 73C, check valve ports 72A, 72B by the check valve bodies 75 made of balls There is a risk that the opening and closing of 72C cannot be performed stably. Therefore, the flow gap H is preferably smaller than about 2/3 of the diameter of the check valve body 75 made of the ball and larger than about 1/5.

  In the motor-operated valve 10 of the present embodiment having such a configuration, the pressure in the valve chamber 21 is larger than the pressure in the lower space 22 when the small flow rate is flowing (at the normal flow) as shown in FIG. The check valve body 75 made of a ball is pressed against the upper opening edge of the check valve ports 72A, 72B, 72C to close the check valve ports 72A, 72B, 72C. The refrigerant (fluid) introduced into the main body 21 mainly flows from the flow gap H, the gap formed between the guide pillars 73A, 73B, 73C, and the portion between the guide pillars 73A, 73B, 73C and the inner peripheral wall surface 21c. It flows out from the lower space 22 to the second inlet / outlet 12 through a gap formed between the valve port 23 and the valve body 24.

  On the other hand, at the time of a large flow rate flow (reverse flow) as shown in FIG. 2, the pressure in the valve chamber 21 is smaller than the pressure in the lower space 22, so the check valve body 75 is placed on the ceiling 21 a of the valve chamber 21. The check valve ports 72A, 72B, 72C (large flow passages) are opened until they come into contact with each other, and the refrigerant (fluid) from the second inlet / outlet 12 flows into the lower space 22 → the check valve ports 72A, 72B, 72C → valve chamber 21 → the flow gap H, the gap formed between the guide pillars 73A, 73B, 73C, the part between the guide pillars 73A, 73B, 73C and the inner peripheral wall surface 21c, etc. It flows to 1 entrance / exit 11.

  As described above, the motor-operated valve 10 according to the present embodiment is formed with the check valve ports 72A, 72B, and 72C so as to bypass the main valve port 23, and closes the check valve ports 72A, 72B, and 72C during normal flow. Since the float type check valve body 75 that opens at the time of reverse flow is provided in the valve chamber 21, there is no increase in the size of the valve body, the internal structure is complicated, the processing and assembly costs are increased, and the like. The flow rate can be controlled with high accuracy during the flow, and the fluid can be flowed so as not to cause a pressure loss as much as possible during the flow of the large flow rate, which is excellent in cost effectiveness.

  The check valve body 75 made of a ball is made of one or more of plastic, lightweight metal such as aluminum, and rubber (for example, elastically applied to the surface of a sphere made of hard plastic with a hollow inside). It can be made relatively lightweight (for example, by covering a rubber having a property). The check valve body 75 can also be made of a metal such as stainless steel, a resin, a ceramic, or the like. The check valve body 75 is made solid or hollow.

  Since the check valve body 75 made of a ball itself has a centering function, the check valve ports 72A, 72B, 72C can be closed in any posture, and the volume is small for the blockable area. In addition to the simple spherical shape, in addition to low fluid resistance, the vertical movement is guided by the guide pillars 73A, 73B, 73C, etc., so the responsiveness to the fluid flow direction (change in pressure) is good, The check valve ports 72A, 72B, 72C can be opened and closed, that is, the flow direction can be changed quickly and stably, and the reliability is improved. Further, if the check valve body 75 is made relatively light, the response to a change in the pressure of the fluid is further improved.

  In addition to the above, the guide columns 73A, 73B, 73C as guide means for reliably and smoothly opening and closing the check valve ports 72A, 72B, 72C by the check valve bodies 75 are the ceiling portions 21a of the valve chamber 21. From the lower end surface of the guide pillars 73A, 73B, 73C and the upper surface of the valve seat body 16 so as to project downward from the valve seat body 16 to a predetermined height position. Compared to the case where a plurality of guide columns are erected upward on the valve seat body 16 and the case where the guide columns are arranged so as to extend without gap from the valve seat body 16 to the ceiling portion 21a, In this case, the flow of the fluid is not so hindered, and the pressure loss during the reverse flow can be effectively reduced.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, in the first embodiment, an example in which three check valve ports, check valve bodies, and three guide columns are provided is shown, but the number of them can be changed as appropriate.

  For example, as shown in FIG. 6 and FIG. 7, there are four sections having a narrow trapezoidal cross section with a relatively low height at intervals of 90 degrees on the ceiling portion 21a of the valve chamber 21 (the lower end portion of the lid-like member 15B). Guide columns 74A, 74B, 74C, 74D are provided to project downward, and a check valve port 72A is provided between the guide columns 74A and 74D, and a check valve port 72B is provided between the guide columns 74B and 74C. A check valve port 72C is positioned between the guide columns 74C and 74D, and a check valve port 72 is provided between the guide columns 74A and 74B, which are opposed to the opening surface of the first inlet / outlet 11. It may not be provided.

  Also in this example, the guide pillars 74A, 74B, 74C, 74D are projected downward from the ceiling portion 21a of the valve chamber 21 to a predetermined height position on the valve seat body 16, and the guide pillars 74A, 74B, 74C, 74D. Since a flow gap H is formed between the lower end surface of the valve seat 16 and the upper surface of the valve seat body 16, as compared to the case where a plurality of guide columns are erected upward on the valve seat body, as previously proposed, The fluid flow is not so hindered during the reverse flow, and the pressure loss during the reverse flow can be effectively reduced.

  Of course, the number of check valve elements is not limited to three, but may be one, two, or four or more.

Furthermore, the shape of the guide column can be changed as appropriate. That is, a plurality of guide columns shown in FIG. 5 or FIG. 6 are provided around the valve rod 25 (around the insertion hole 19), and each check valve is provided between the side surfaces of the adjacent guide columns and between the valve chamber walls. Although the body 75 is guided, the present invention is not particularly limited to this. For example, each check valve body 75 is guided so as to guide each check valve body 75 from both sides. A pair of arc-shaped guide columns each having a cross-sectional shape projecting downward from the ceiling portion 21a so that the check valve is guided only by the pair of guide columns without using the inner peripheral wall surface 21c of the valve chamber 21. Anyway. That is, when there are three check valve bodies 75, there are six guide members.
In this case, each guide column can be provided in the arrangement direction (circumferential direction) of each check valve body 75.

  In the above embodiment, the check valve body is a ball. However, the check valve body does not necessarily have to be a ball, and the opening of the check valve port such as a spherical surface, an elliptical surface, or a conical surface is used. Any shape such as a columnar shape or a prismatic shape may be used as long as it is composed of a curved surface that is substantially in line contact with the edge.

  Further, in the above embodiment, the main valve port and the check valve port are formed in the valve seat body 16, but the main valve port and / or the check valve port is a valve seat different from the valve seat body 16. The valve seat may be attached to the valve seat body 16.

  Furthermore, it goes without saying that the motor-operated valve according to the present invention can be applied not only to a heat pump air conditioning system but also to other systems.

DESCRIPTION OF SYMBOLS 10 Electric valve 11 1st inlet / outlet 12 2nd inlet / outlet 15 Valve main body 16 Valve seat body 21 Valve chamber 21a Ceiling part 21c Inner peripheral wall surface 22 Lower space 23 Main valve port 24 Valve body part 25 Valve shaft 50 Motor 72 Check valve Mouth 73, 74 Guide column 75 Check valve body (ball)

Claims (5)

A valve main body provided with a first inlet / outlet, a valve chamber, and a second inlet / outlet, and a valve seat constituting a flow passage for small flow rate are formed, and between the valve chamber and the second inlet / outlet in the valve main body. A valve seat body having a main valve port provided in the valve chamber, and a needle-type valve body disposed in the valve chamber so as to adjust a flow rate flowing from the valve chamber to the second inlet / outlet through the main valve port A valve shaft having a portion, and a motor for raising and lowering the valve shaft,
In the valve body, there is formed a flow passage for large flow rate that bypasses the main valve port, and a float type check valve body that closes the flow passage for large flow rate during normal flow and opens during reverse flow is the valve. Deployed in the room,
The large flow path has at least one check valve port,
The check valve body is provided in the same number as the check valve port, and includes a guide means in the valve chamber so that the check valve opens and closes the check valve port,
A guide column as the guide means protrudes downward from the ceiling of the valve chamber to a predetermined height position on the valve seat body, and flows between the lower end surface of the guide column and the upper surface of the valve seat body. A motor-operated valve in which a gap is formed.   The motor-operated valve according to claim 1, wherein an inner peripheral wall surface of the valve chamber constitutes a part of the guide means.   The motor-operated valve according to claim 1, wherein the check valve port is formed on an outer peripheral side of the main valve port.   The motor-operated valve according to any one of claims 1 to 3, wherein the check valve body is a sphere or a columnar body whose lower end closes the check valve port.   The electric valve according to any one of claims 1 to 3, wherein the valve seat body is formed integrally with the valve body.

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