JP2017044347A - Motor valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor valve capable of controlling a flow rate in a high precise manner at the time of flowing a small flow rate and capable of flowing fluid so as not to produce pressure loss as much as possible at the time of flowing a large flow rate without making any large-sized formation of a valve main body, a complex formation of an inner structure and increasing in processing or assembling cost and the like.SOLUTION: A movable valve seat body 70 formed with a main valve port 23 for forming a flow passage for a small flow rate facing from a first inlet/outlet port 11 to a second inlet/outlet port 12 is placed between a valve chamber 21 and a lower chamber 22. The movable valve seat body 70 has its lower part that is slidably fitted and inserted into the lower chamber 22 and may act also as a float-type check valve body for opening/shutting off a flow passage for a large flow rate facing from a second inlet/outlet port 12 to the first inlet/outlet port 11. The movable valve seat body 70 has a valve seat plate part 72 having its outer peripheral part contacted with or removed from an opening end edge part 22a of the valve chamber at the lower chamber so as to open or shut off the flow passage for a large flow rate, and the valve seat plate part is arranged in the valve chamber 21.SELECTED DRAWING: Figure 3

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. 6 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 air flows into the indoor heat exchanger 104, heat is exchanged with the indoor air in the indoor heat exchanger 104, evaporates, and the room is cooled.

  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 main body 15 having a valve chamber 21 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. An elevating drive mechanism for adjusting the lift amount of the valve body 24 with respect to the valve port 23 is configured by (described later) or the like.

  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, in order to achieve both a reduction in pressure loss at the time of a large flow rate and an improvement in flow control accuracy at the time of a small flow rate, as described in Patent Document 3, the first inlet / outlet, the valve chamber, the lower chamber, and A valve main body provided with a second inlet / outlet and a main valve port arranged in the valve chamber for forming a small flow rate channel from the first inlet / outlet to the second inlet / outlet are formed. A movable valve seat body that also functions as a float type check valve body for opening / closing a flow passage for large flow rate from the second inlet / outlet to the first inlet / outlet, and a flow rate through the main valve port. A valve shaft having a needle-type valve element disposed in the valve chamber to be adjusted, and a motor for raising and lowering the valve shaft. The large flow passage is closed by the movable valve seat, and the fluid flows between the valve body and the main valve port. When the flow rate is large, the bidirectional valve is configured to float the movable valve seat (check valve body) and open the flow path for large flow rate in order to reduce pressure loss as much as possible. A flow-type electric valve has been proposed.

Japanese Patent Laid-Open No. 2001-50415 JP 2009-14056 A JP 2009-287913 A

  However, in the motor-operated valve described in Patent Document 3, flow control is performed only with a needle-type valve body when a small flow rate is distributed, and a movable valve seat (check valve body) is used for a large flow rate when a large flow rate is distributed. Since the flow path is automatically opened, it is possible to achieve both improvement in flow rate control accuracy at low flow rate and reduction of pressure loss at high flow rate. Valve body) is arranged in the valve chamber in which the valve shaft is arranged, and the movable valve seat body is moved up and down with the inner peripheral wall surface of the valve chamber as a sliding guide surface. And a relatively large space is required in the valve chamber to move the movable valve seat up and down, resulting in an increase in the size of the valve body, a complicated internal structure, and an increase in processing and assembly costs. It is easy and cost effective.

  In addition, in this motor-operated valve, a communication hole having a size that does not affect the flow rate characteristic of the needle when the flow rate is small must be provided on the side surface of the movable valve seat body.

  The present invention has been made in view of such circumstances, and its purpose is to increase the valve body size, to increase the complexity of the internal structure, to increase the processing and assembly costs, etc. An object of the present invention is to provide a motor-driven valve that is capable of controlling the flow rate with high accuracy and is capable of flowing a fluid so that a pressure loss does not occur as much as possible when a large flow rate is distributed. 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 object, the motor-operated valve according to the present invention basically includes a first inlet / outlet, a valve chamber in which the first inlet / outlet opens, a lower chamber connected to the valve chamber, and a lower chamber connected to the valve chamber. A main valve for forming a flow passage for small flow rate disposed between the valve body provided with the second inlet / outlet and the valve chamber and the lower chamber and going from the first inlet / outlet to the second inlet / outlet. A movable valve seat having a port, a valve shaft having a needle-type valve body disposed in the valve chamber to adjust a flow rate through the main valve port, and a valve shaft for raising and lowering the valve shaft A movable valve seat body, the lower part of which is slidably inserted into the lower chamber, and opens and shuts off the flow path for large flow from the second inlet / outlet to the first inlet / outlet. It is also characterized by functioning as a float type check valve body.

  The movable valve seat body preferably has a valve seat plate portion whose outer peripheral portion is in contact with or separated from an opening edge portion on the valve chamber side in the lower chamber in order to open / close the flow passage for large flow rate. An insertion portion that is slidably inserted into the lower chamber after falling from the valve seat plate portion, the main valve port is formed in the valve seat plate portion, and the insertion portion A communication passage such as a through hole, a notch, or a groove for forming the large flow rate channel is formed.

  The flow passage for large flow rate is preferably configured by the lower chamber, a communication passage such as a through hole, a notch, or a groove formed in the insertion portion of the movable valve seat body, and the valve chamber.

  In the motor-operated valve according to the present invention, the movable valve seat that also functions as a float type check valve body can be slid freely in the lower chamber when the large flow passage is closed. When the large flow passage is opened, it floats to the valve chamber side, so that the entire movable valve seat body is distributed in the valve chamber 21 as in the prior art. In addition, the structure can be simplified, the movable valve seat body can be made smaller without reducing the maximum flow rate, and a large space for raising and lowering the movable valve seat body in the valve chamber is unnecessary. It becomes.

  For this reason, it is possible to effectively reduce the size of the valve body, reduce component costs, and reduce processing costs.

The partial cutaway sectional view showing the state at the time of non-circulation (at the time of full closure) of the principal part of one example of the electric valve concerning the present invention. The partial notch sectional view which shows the state at the time of the positive flow (at the time of the distribution | circulation for small flow rates) of the principal part of one Example of the motor operated valve which concerns on this invention. The partial notch sectional view which shows the state at the time of the reverse flow (at the time of the distribution | circulation for large flow rates) of the principal part of one Example of the motor operated valve which concerns on this invention. An example of the movable valve seat used for the motor-driven valve shown in FIGS. 1 to 3 is shown, (A) is a perspective view, (B) is a plan view, (C) is a side view, and (D) is a bottom view. . FIG. 1 shows another example of a movable valve seat used in the motor-operated valve shown in FIGS. 1 to 3, (A) is a perspective view, (B) is a plan view, (C) is a side view, and (D) is a side view. Bottom view. 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, 2, and 3 are partially cutaway cross-sectional views of the main part of one embodiment of the motor-operated valve according to the present invention. FIG. 1 is a non-flowing state (when fully closed), and FIG. FIG. 3 shows a reverse flow (when a large flow rate is flowing). 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. 2), and the second inlet / outlet 12 → the first inlet / outlet 11 is the case. This is referred to as reverse flow (FIG. 3).

  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. 7 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 describes the main parts (characteristic parts).

  The valve body 15 of the present embodiment includes a first inlet / outlet 11, a valve chamber 21 in which the first inlet / outlet opens, a cylindrical lower chamber 22 connected to the valve chamber 21, in the forward flow direction, And a second inlet / outlet 12 connected to the lower chamber 22.

  More specifically, the lid-like member 18 having the upper surface opening hole 42 into which the lower large diameter portion 26a of the guide bush 26 is press-fitted and fixed is attached and fitted to the upper portion of the valve body 15 and joined by welding. Yes. A guide hole 19 into which the valve shaft 25 is slidably fitted is provided in the lower part of the lid-like member.

  A movable valve seat body 70 is disposed between the valve chamber 21 and the lower chamber 22. The movable valve seat body 70 is formed with a main valve port 23 for forming a small flow rate channel from the first inlet / outlet 11 to the second inlet / outlet 12.

  In addition, the movable valve seat body 70 is slidably inserted into the lower chamber 22 so as to open and shut off the large flow passage from the second inlet / outlet 12 to the first inlet / outlet 11. It is designed to function as a float type check valve body.

  More specifically, the movable valve seat body 70 includes a valve seat plate portion 72 and a cylindrical fitting insertion portion 75 connected to the valve seat plate portion 72, as can be understood by referring to FIG. 4 in addition to FIGS. It has become. The valve seat plate portion 72 has an outer peripheral portion on an opening edge portion 22a on the valve chamber 21 side in the lower chamber 22 (which corresponds to a valve seat of a check valve port) in order to open / close the flow passage for large flow rate. A check valve body portion 73 formed of an inverted conical surface portion formed on the lower surface side is configured to contact and separate. The fitting insertion portion 75 falls from the vicinity of the lower end of the check valve body portion 73 in the valve seat plate portion 72 and is slidably inserted into the lower chamber 22.

  At the center of the valve seat plate portion 72 of the movable valve seat body 70, 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, and the movable valve seat body. Four circular through holes 76 are formed at equiangular (90 degrees) intervals in the upper portion of the fitting insertion portion 75 of 70 to form a flow passage for large flow rate.

  Here, in this embodiment, the flow passage for large flow rate is configured by the lower chamber 22, four through holes 76 formed in the fitting insertion portion 75 of the movable valve seat body 70, and the valve chamber 21. Yes.

  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 chamber 22 when a small flow rate is flowing (at the normal flow) as shown in FIG. The check valve body 73 of the movable valve seat 70 is pressed against the opening end edge 22a (check valve port) on the valve chamber 21 side in the lower chamber 22, thereby closing the flow passage for large flow rate. The refrigerant (fluid) introduced into the valve chamber 21 from the first inlet / outlet 11 flows out from the lower chamber 22 to the second inlet / outlet 12 through a gap formed between the main valve port 23 and the valve body portion 24. .

  On the other hand, the valve shaft 25 is raised to, for example, the maximum lift position during a large flow rate flow (reverse flow) as shown in FIG. In this case, since the pressure in the valve chamber 21 is smaller than the pressure in the lower chamber 22, the movable valve seat body 70 is pushed up by the fluid (refrigerant) pressure until it contacts the lower end of the lid-like member 18. As a result, the check valve body 73 of the movable valve seat 70 is separated from the opening edge 22a (check valve port) on the valve chamber 21 side in the lower chamber 22, and the four through holes 76 are formed in the valve chamber 21. Four refrigerants (fluids) from the second inlet / outlet 12 are formed in the fitting portion 75 of the lower chamber 22 → movable valve seat body 70 constituting the flow passage for large flow rate. Through the valve chamber 21 to the first inlet / outlet 11.

  As described above, the motor-operated valve 10 of this embodiment can control the flow rate with high accuracy when the flow rate is small, and can flow the fluid so that pressure loss does not occur as much as possible when the flow rate is large. The change can be performed promptly and stably, and the operation state can be stabilized and the reliability can be improved.

  In addition to the above, most of the movable valve seat 70 that also functions as a float type check valve body (the fitting insertion portion 75) is slidable into the lower chamber 22 when the flow passage for large flow rate is closed. When the flow passage for large flow rate is opened, it floats to the valve chamber 21 side. Therefore, when the entire movable valve seat body is distributed in the valve chamber 21 as in the prior art. In comparison, the structure can be simplified, the movable valve seat body can be made smaller without reducing the maximum flow rate, and a large space for raising and lowering the movable valve seat body in the valve chamber is It becomes unnecessary.

  For this reason, it is possible to effectively reduce the size of the valve body, reduce component costs, and reduce processing costs.

  The movable valve seat body 70 can be made of a metal such as stainless steel or brass as a material. The movable valve seat body 70 is made of one or a plurality of plastics, lightweight metals such as aluminum, ceramics, rubber, etc. (for example, the movable valve seat body is made of hard plastic or the like, and its surface has elasticity. It can also be made relatively lightweight (for example, by coating rubber with

  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 above embodiment, four circular through-holes 76 are formed at equiangular (90 degrees) intervals so as to form a flow passage for large flow rate in the upper part of the fitting insertion portion 75 of the movable valve seat body 70. However, as shown in FIG. 5, instead of the through-hole 76, a semi-race track-shaped notch 77 whose lower side opens may be formed in the fitting insertion portion 75. The number and shape of the through holes 76 and the notches 77 can be changed as appropriate. Further, a vertical groove or the like may be formed in place of the through hole 76 and the notch 77. That is, it is only necessary to provide the insertion portion 75 with a communication path that communicates the lower chamber 22 and the valve chamber 21 when the movable valve seat 70 is raised. The number is not limited to the notch 77, the longitudinal groove, and the like.

  Moreover, it cannot be overemphasized that the motor operated valve which concerns on this invention is applicable not only to a heat pump type | formula air conditioning system but to another system.

DESCRIPTION OF SYMBOLS 10 Motorized valve 11 1st inlet / outlet 12 2nd inlet / outlet 15 Valve main body 21 Valve chamber 22 Lower chamber 22a Open end edge part 23 Main valve opening 24 Valve body part 25 Valve shaft 50 Motor 70 Movable valve seat body 72 Valve seat board part 73 Check valve body part 75 Insertion part 76 Through hole (communication path)
77 Notch (communication passage)

  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. 6 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 air flows into the indoor heat exchanger 104, heat is exchanged with the indoor air in the indoor heat exchanger 104, evaporates, and the room is cooled.

  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 main body 15 having a valve chamber 21 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. An elevating drive mechanism for adjusting the lift amount of the valve body 24 with respect to the valve port 23 is configured by (described later) or the like.

  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, in order to achieve both a reduction in pressure loss at the time of a large flow rate and an improvement in flow control accuracy at the time of a small flow rate, as described in Patent Document 3, the first inlet / outlet, the valve chamber, the lower chamber, and A valve main body provided with a second inlet / outlet and a main valve port arranged in the valve chamber for forming a small flow rate channel from the first inlet / outlet to the second inlet / outlet are formed. A movable valve seat body that also functions as a float type check valve body for opening / closing a flow passage for large flow rate from the second inlet / outlet to the first inlet / outlet, and a flow rate through the main valve port. A valve shaft having a needle-type valve element disposed in the valve chamber to be adjusted, and a motor for raising and lowering the valve shaft. The large flow passage is closed by the movable valve seat, and the fluid flows between the valve body and the main valve port. When the flow rate is large, the bidirectional valve is configured to float the movable valve seat (check valve body) and open the flow path for large flow rate in order to reduce pressure loss as much as possible. A flow-type electric valve has been proposed.

Japanese Patent Laid-Open No. 2001-50415 JP 2009-14056 A JP 2009-287913 A

  However, in the motor-operated valve described in Patent Document 3, flow control is performed only with a needle-type valve body when a small flow rate is distributed, and a movable valve seat (check valve body) is used for a large flow rate when a large flow rate is distributed. Since the flow path is automatically opened, it is possible to achieve both improvement in flow rate control accuracy at low flow rate and reduction of pressure loss at high flow rate. Valve body) is arranged in the valve chamber in which the valve shaft is arranged, and the movable valve seat body is moved up and down with the inner peripheral wall surface of the valve chamber as a sliding guide surface. And a relatively large space is required in the valve chamber to move the movable valve seat up and down, resulting in an increase in the size of the valve body, a complicated internal structure, and an increase in processing and assembly costs. It is easy and cost effective.

  In addition, in this motor-operated valve, a communication hole having a size that does not affect the flow rate characteristic of the needle when the flow rate is small must be provided on the side surface of the movable valve seat body.

  The present invention has been made in view of such circumstances, and its purpose is to increase the valve body size, to increase the complexity of the internal structure, to increase the processing and assembly costs, etc. An object of the present invention is to provide a motor-driven valve that is capable of controlling the flow rate with high accuracy and is capable of flowing a fluid so that a pressure loss does not occur as much as possible when a large flow rate is distributed. 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 object, the motor-operated valve according to the present invention basically includes a first inlet / outlet, a valve chamber in which the first inlet / outlet opens, a lower chamber connected to the valve chamber, and a lower chamber connected to the valve chamber. A main valve for forming a flow passage for small flow rate disposed between the valve body provided with the second inlet / outlet and the valve chamber and the lower chamber and going from the first inlet / outlet to the second inlet / outlet. A movable valve seat having a port, a valve shaft having a needle-type valve body disposed in the valve chamber to adjust a flow rate through the main valve port, and a valve shaft for raising and lowering the valve shaft A movable valve seat body, the lower part of which is slidably inserted into the lower chamber, and opens and shuts off the flow path for large flow from the second inlet / outlet to the first inlet / outlet. It is also functions as a check valve of the float type for the movable valve seat body, in order to open and blocking the large flow passage, before A valve seat plate portion that its outer peripheral portion to the opening edge portion of the valve chamber side of the lower chamber and moving away, the valve seat plate portion is characterized by being disposed in the valve chamber.

The valve seat plate portion is preferably formed to have an outer diameter smaller than the inner diameter of the upper opening of the valve body.

In the motor-operated valve according to the present invention, the movable valve seat that also functions as a float type check valve body can be slid freely in the lower chamber when the large flow passage is closed. When the large flow passage is opened, it floats to the valve chamber side, so that the entire movable valve seat body is distributed in the valve chamber 21 as in the prior art. and, on can be simplified in construction, without reducing the maximum flow amount, it is possible to reduce the movable valve seat body, to place the valve seat plate portion of the movable valve seat body into the valve chamber Therefore, a large space for raising and lowering the movable valve seat body is unnecessary.

For this reason, it is possible to effectively reduce the size of the valve body, reduce component costs, and reduce processing costs. Further, by forming the valve seat plate portion with an outer diameter smaller than the inner diameter of the upper opening of the valve body, the movable valve seat body can be easily incorporated into the valve body, and the assemblability can be improved. .

The partial cutaway sectional view showing the state at the time of non-circulation (at the time of full closure) of the principal part of one example of the electric valve concerning the present invention. The partial notch sectional view which shows the state at the time of the positive flow (at the time of the distribution | circulation for small flow rates) of the principal part of one Example of the motor operated valve which concerns on this invention. The partial notch sectional view which shows the state at the time of the reverse flow (at the time of the distribution | circulation for large flow rates) of the principal part of one Example of the motor operated valve which concerns on this invention. An example of the movable valve seat used for the motor-driven valve shown in FIGS. 1 to 3 is shown, (A) is a perspective view, (B) is a plan view, (C) is a side view, and (D) is a bottom view. . FIG. 1 shows another example of a movable valve seat used in the motor-operated valve shown in FIGS. 1 to 3, (A) is a perspective view, (B) is a plan view, (C) is a side view, and (D) is a side view. Bottom view. 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, 2, and 3 are partially cutaway cross-sectional views of the main part of one embodiment of the motor-operated valve according to the present invention. FIG. 1 is a non-flowing state (when fully closed), and FIG. FIG. 3 shows a reverse flow (when a large flow rate is flowing). 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. 2), and the second inlet / outlet 12 → the first inlet / outlet 11 is the case. This is called reverse flow (FIG. 3).

  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. 7 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 describes the main parts (characteristic parts).

  The valve body 15 of the present embodiment includes a first inlet / outlet 11, a valve chamber 21 in which the first inlet / outlet opens, a cylindrical lower chamber 22 connected to the valve chamber 21, in the forward flow direction, And a second inlet / outlet 12 connected to the lower chamber 22.

  More specifically, the lid-like member 18 having the upper surface opening hole 42 into which the lower large diameter portion 26a of the guide bush 26 is press-fitted and fixed is attached and fitted to the upper portion of the valve body 15 and joined by welding. Yes. A guide hole 19 into which the valve shaft 25 is slidably fitted is provided in the lower part of the lid-like member.

  A movable valve seat body 70 is disposed between the valve chamber 21 and the lower chamber 22. The movable valve seat body 70 is formed with a main valve port 23 for forming a small flow rate channel from the first inlet / outlet 11 to the second inlet / outlet 12.

  In addition, the movable valve seat body 70 is slidably inserted into the lower chamber 22 so as to open and shut off the large flow passage from the second inlet / outlet 12 to the first inlet / outlet 11. It is designed to function as a float type check valve body.

More specifically, the movable valve seat body 70 includes a valve seat plate portion 72 and a cylindrical fitting insertion portion 75 connected to the valve seat plate portion 72, as can be understood by referring to FIG. 4 in addition to FIGS. It has become. The valve seat plate portion 72 has an outer peripheral portion on an opening edge portion 22a on the valve chamber 21 side in the lower chamber 22 (which corresponds to a valve seat of a check valve port) in order to open / close the flow passage for large flow rate. A check valve body portion 73 formed of an inverted conical surface portion formed on the lower surface side is configured to contact and separate. The fitting insertion portion 75 falls from the vicinity of the lower end of the check valve body portion 73 in the valve seat plate portion 72 and is slidably inserted into the lower chamber 22. The valve seat plate portion 72 of the movable valve seat body 70 is disposed in the valve chamber 21, and the diameter of the valve seat plate portion 72 is formed to be smaller than the upper opening of the valve body 15. The upper opening of the valve body 15 is closed by a guide bush 26 and a lid-like member 18 that project downward from the stepping motor 50, as shown in FIG.

  At the center of the valve seat plate portion 72 of the movable valve seat body 70, 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, and the movable valve seat body. Four circular through holes 76 are formed at equiangular (90 degrees) intervals in the upper portion of the fitting insertion portion 75 of 70 to form a flow passage for large flow rate.

  Here, in this embodiment, the flow passage for large flow rate is configured by the lower chamber 22, four through holes 76 formed in the fitting insertion portion 75 of the movable valve seat body 70, and the valve chamber 21. Yes.

  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 chamber 22 when a small flow rate is flowing (at the normal flow) as shown in FIG. The check valve body 73 of the movable valve seat 70 is pressed against the opening end edge 22a (check valve port) on the valve chamber 21 side in the lower chamber 22, thereby closing the flow passage for large flow rate. The refrigerant (fluid) introduced into the valve chamber 21 from the first inlet / outlet 11 flows out from the lower chamber 22 to the second inlet / outlet 12 through a gap formed between the main valve port 23 and the valve body portion 24. .

  On the other hand, the valve shaft 25 is raised to, for example, the maximum lift position during a large flow rate flow (reverse flow) as shown in FIG. In this case, since the pressure in the valve chamber 21 is smaller than the pressure in the lower chamber 22, the movable valve seat body 70 is pushed up by the fluid (refrigerant) pressure until it contacts the lower end of the lid-like member 18. As a result, the check valve body 73 of the movable valve seat 70 is separated from the opening edge 22a (check valve port) on the valve chamber 21 side in the lower chamber 22, and the four through holes 76 are formed in the valve chamber 21. Four refrigerants (fluids) from the second inlet / outlet 12 are formed in the fitting portion 75 of the lower chamber 22 → movable valve seat body 70 constituting the flow passage for large flow rate. Through the valve chamber 21 to the first inlet / outlet 11.

  As described above, the motor-operated valve 10 of this embodiment can control the flow rate with high accuracy when the flow rate is small, and can flow the fluid so that pressure loss does not occur as much as possible when the flow rate is large. The change can be performed promptly and stably, and the operation state can be stabilized and the reliability can be improved.

  In addition to the above, most of the movable valve seat 70 that also functions as a float type check valve body (the fitting insertion portion 75) is slidable into the lower chamber 22 when the flow passage for large flow rate is closed. When the flow passage for large flow rate is opened, it floats to the valve chamber 21 side. Therefore, when the entire movable valve seat body is distributed in the valve chamber 21 as in the prior art. In comparison, the structure can be simplified, the movable valve seat body can be made smaller without reducing the maximum flow rate, and a large space for raising and lowering the movable valve seat body in the valve chamber is It becomes unnecessary.

For this reason, it is possible to effectively reduce the size of the valve body, reduce component costs, and reduce processing costs. Further, since the valve seat plate portion 72 of the movable valve seat body 70 is formed to have an outer diameter smaller than the inner diameter of the upper opening of the valve main body 15, it can be inserted from the upper opening, improving the assembly and the configuration. Simplification can be achieved.

  The movable valve seat body 70 can be made of a metal such as stainless steel or brass as a material. The movable valve seat body 70 is made of one or a plurality of plastics, lightweight metals such as aluminum, ceramics, rubber, etc. (for example, the movable valve seat body is made of hard plastic or the like, and its surface has elasticity. It can also be made relatively lightweight (for example, by coating rubber with

  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 above embodiment, four circular through-holes 76 are formed at equiangular (90 degrees) intervals so as to form a flow passage for large flow rate in the upper part of the fitting insertion portion 75 of the movable valve seat body 70. However, as shown in FIG. 5, instead of the through-hole 76, a semi-race track-shaped notch 77 whose lower side opens may be formed in the fitting insertion portion 75. The number and shape of the through holes 76 and the notches 77 can be changed as appropriate. Further, a vertical groove or the like may be formed in place of the through hole 76 and the notch 77. That is, it is only necessary to provide the insertion portion 75 with a communication path that communicates the lower chamber 22 and the valve chamber 21 when the movable valve seat 70 is raised. The number is not limited to the notch 77, the longitudinal groove, and the like.

  Moreover, it cannot be overemphasized that the motor operated valve which concerns on this invention is applicable not only to a heat pump type | formula air conditioning system but to another system.

DESCRIPTION OF SYMBOLS 10 Motorized valve 11 1st inlet / outlet 12 2nd inlet / outlet 15 Valve main body 21 Valve chamber 22 Lower chamber 22a Open end edge part 23 Main valve opening 24 Valve body part 25 Valve shaft 50 Motor 70 Movable valve seat body 72 Valve seat board part 73 Check valve body part 75 Insertion part 76 Through hole (communication path)
77 Notch (communication passage)

Claims (2)

A valve body provided with a first inlet / outlet, a valve chamber in which the first inlet / outlet opens, a lower chamber connected to the valve chamber, and a second inlet / outlet connected to the lower chamber; and the valve chamber and the lower chamber A movable valve seat body formed with a main valve port for forming a flow passage for small flow rate that is arranged between the first inlet port and the second inlet port and adjusts the flow rate through 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,
The movable valve seat body is slidably inserted into the lower chamber, and is a reverse of a float type for opening / closing a flow path for large flow from the second inlet / outlet to the first inlet / outlet. It is designed to function as a stop body,
The movable valve seat body has a valve seat plate portion whose outer peripheral portion is in contact with and separated from an opening edge portion on the valve chamber side in the lower chamber in order to open / close the flow passage for large flow rate, The motor-operated valve characterized in that the valve seat plate portion is disposed in the valve chamber.   The motor-operated valve according to claim 1, wherein the valve seat plate portion has an outer diameter smaller than an inner diameter of an upper opening of the valve body.

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