JP5019862B2 - Pilot type control valve - Google Patents

Description

  The present invention relates to a control valve suitable for use in a refrigeration cycle such as an air conditioner, and more particularly to a pilot-type control valve capable of arbitrarily and finely adjusting a valve opening (opening area).

  For example, in a multi-air conditioner having a plurality of indoor units for one outdoor unit, a control valve suitable for being distributed between the outdoor unit and the indoor unit is also found in Patent Document 1 below. As described above, a pilot type control valve using an electromagnetic valve as a pilot valve is known.

  Such a pilot-type control valve usually includes a main valve and an electromagnetic pilot valve, and the main valve is slidably fitted into a valve body in which a valve chamber into which refrigerant is introduced and led is formed and the valve body. And a main valve body that is inserted into and separated from a main valve seat provided in the valve body, and the main valve body is constantly urged upward (in the valve opening direction) by a compression coil spring. Further, the electromagnetic pilot valve (the defining member) is hermetically fixed to the upper portion so as to close the upper surface opening of the valve body.

  In the valve body, the valve chamber is formed between the main valve body and the main valve seat, and a back pressure chamber is defined between the main valve body and the electromagnetic pilot valve (the defining member). .

  A pilot passage is formed in the main valve body so as to penetrate vertically, so that the valve body of the electromagnetic pilot valve contacts and separates from a pilot valve seat (valve port) provided at an upper end portion of the pilot passage. Has been. In addition, a pressure equalizing passage is formed in the main valve body or the valve body so as to communicate the valve chamber and the back pressure chamber.

  In the pilot type control valve having such a configuration, when the electromagnetic pilot valve is not energized, the pilot valve body closes the pilot valve seat and the pilot valve seat is closed by the biasing force of the valve closing spring in the pilot valve. Since the valve body of the valve presses the main valve body downward (in the valve closing direction), the main valve is also closed. Therefore, at this time, the high-pressure refrigerant introduced into the valve chamber is not led out to the outlet, but since the high-pressure refrigerant is introduced into the back pressure chamber through the pressure equalizing passage, the back pressure chamber also becomes high pressure, and the main valve The body is strongly pressed against the main valve seat.

  On the other hand, when the electromagnetic pilot valve is energized from the closed state, the pilot valve body is lifted away from the pilot valve seat and the pilot valve is opened. As a result, the refrigerant in the back pressure chamber is led out to the outlet through the pilot passage, the pressure in the back pressure chamber decreases, and the force that pushes up the main valve body such as the urging force of the compression coil spring (force to open the valve) The force to push down the body (force to close the valve) is overcome, the main valve body is pushed up, and the main valve opens.

JP-A 64-3177

  In the conventional pilot type control valve as described above, if the small-diameter pilot valve is opened, the large-diameter main valve can be opened in response to it, so that the large-diameter main valve can be opened and closed with a small driving force. However, since the solenoid valve is used as the pilot valve, there are the following disadvantages. That is, only two positions of the fully closed state and the fully open state can be taken substantially, and the valve opening degree (opening area) cannot be finely adjusted. Further, since only the opening area of the pilot valve is opened until the main valve is opened, the opening area of the entire valve is small, it takes time to equalize pressure, and it cannot be said that the responsiveness is good. Further, when the main valve opens, the opening area increases at a stretch, so that the flow rate changes rapidly and annoying noise is generated.

  The present invention has been made in view of the above circumstances, and the object of the present invention is that the valve opening can be arbitrarily and finely adjusted, and the generation of noise can be effectively suppressed. An object of the present invention is to provide a pilot type control valve that can obtain excellent responsiveness, operational stability, control characteristics, and the like.

In order to achieve the above object, a pilot type control valve according to the present invention is basically a pilot type control valve having a main valve and an electric pilot valve, and a fluid is introduced into the main valve. An inverted cross section having a valve body formed with a valve chamber to be led out, and a large-diameter portion and a small-diameter portion that are slidably inserted into the valve body and open and close a main valve port provided in the valve body. A piston-type main valve body having a convex shape, and the electric pilot valve is attached so as to close an upper surface opening of the valve body, and defines a back pressure chamber between the main valve body and the main valve body. And a pressure equalizing passage that communicates the valve chamber and the back pressure chamber to the main valve, the pilot valve body opening and closing a pilot valve port provided in the main valve body. And the main valve body is normally urged in the valve opening direction by a compression coil spring, and the So as to follow the movement of the valve opening direction of the pilots valve body, the main valve body is adapted to move in the valve opening direction.

The valve body includes a valve chamber cylinder into which the main valve body is slidably inserted, and a valve seat member having a stepped cylindrical portion provided at a lower portion of the valve chamber cylinder. The compression coil spring is interposed between a lower end surface portion with a downward projecting portion provided in a large diameter portion of the main valve body and a terrace surface portion of the valve seat member, and upper and lower end portions thereof are The main valve body has a downward projecting portion and a cylindrical portion of the valve seat member, and the diameter of the main valve port is 3 to 9 times the diameter of the pilot valve port.
In a preferred aspect, the pilot type control valve is configured such that the pilot valve body is opened and closed by an electric motor, and the main valve port is opened and closed by the main valve body in response to the pilot valve body. The main valve body moves in the valve opening direction so as to follow the movement of the pilot valve body in the valve opening direction. Further, a seal member is disposed between the large diameter portion of the main valve body and the inner wall of the valve body into which the main valve body is inserted.

  In a preferred embodiment, the outer diameter of the large diameter portion of the main valve body is 1.5 to 3 times the diameter of the main valve port. That is, in FIG. 6, the outer diameter of the large diameter portion of the main valve body is the diameter of the main valve port so that the opening area of the pilot valve (of the valve port) necessary for opening the main valve is illustrated. If the magnification is less than 1.5 times, the required opening area of the pilot valve increases steeply as the magnification decreases. This means that a smaller pilot factor requires a larger pilot valve and a larger valve opening driving force. If the magnification exceeds three times, the required opening area of the pilot valve does not become so small. Therefore, even if the magnification is 3 times or more, the size of the pilot valve and the valve opening driving force cannot be reduced so much.

  In another preferred embodiment, the pilot valve body and the main valve body are moved together in the valve opening direction while the opening degree of the electric pilot valve is kept substantially constant.

  The electric pilot valve preferably includes a can, a rotor disposed on an inner periphery of the can, a stator externally mounted on the can to rotationally drive the rotor, the rotor, and the pilot valve body. And a drive mechanism that moves the pilot valve body in the axial direction by using rotation of the rotor.

In another preferred embodiment, the outer diameter of the large diameter portion of the main valve body is larger than the outer diameter of the rotor, as described above, the diameter of the main valve port, the diameter of the pre-Symbol pilot valve port 3-9 to be doubled, opening the pilot valve of small diameter, it can be open main valve of the response to a large diameter, Ru can open and close the large-diameter main valve with a small driving force.

In this case, it is preferable that a locking portion for fixing and holding the lower end portion of the compression coil spring is provided in the cylindrical portion of the valve seat member.

  The locking portion is preferably formed of a male screw-like portion into which a lower end portion of the compression coil spring is screwed.

  In another preferred embodiment, a conical surface portion is provided in the downward projecting portion of the main valve body.

  In the pilot type control valve according to the present invention, since the pilot valve is an electric type instead of an electromagnetic type, the valve opening (opening area) changes smoothly according to the number of pulses supplied to the pilot valve. And equalization time can be shortened. Therefore, the valve opening (opening area) can be arbitrarily and finely adjusted, the generation of noise can be effectively suppressed, and excellent responsiveness, operational stability, control characteristics, etc. can be obtained. . Also, by setting the outer diameter of the large diameter part of the main valve body to 1.5 to 3 times the diameter of the main valve port, the pilot valve can be made the minimum necessary size, and as a result, the valve can be opened and closed. The required power consumption can be reduced, the entire valve including the motor can be made compact, and the main valve body slides more stably. Is obtained.

  In addition to the above, the cylindrical portion of the valve seat member is provided with a locking portion such as a male threaded portion for fixing and holding the lower end portion of the compression coil spring, so that the compression coil spring (the lower end portion thereof) is It becomes difficult to cause undesired behavior such as lifting from the seat member (spring receiving part such as a terrace surface) or coming out of the cylindrical part. As a result, it is possible to surely prevent malfunction and further improve Operation stability, control characteristics, and the like can be obtained, and noise reduction can be achieved.

  Further, by providing a conical surface portion in the downward projecting portion of the main valve body, the upper end portion of the compression coil spring is separated from the lower end surface portion (spring receiving portion) of the large diameter portion of the main valve body and on the downward projecting portion. Even if it gets on, it can return to the original lower end surface part (spring receiving part) immediately, and thereby it is possible to prevent malfunction more reliably.

  Embodiments of a pilot type control valve of the present invention will be described below with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a pilot type control valve according to the present invention.

  The pilot type control valve 1 of the illustrated embodiment is suitable for being distributed between an outdoor unit and an indoor unit in an air conditioner such as a multi air conditioner. The type is an electric pilot type, and the main valve 5 and an electric pilot valve 7 provided on the upper side of the main valve 5.

  The main valve 5 has a valve body 10 including a cylindrical valve chamber cylinder 11 having a bottom with a hole, and a valve seat member 12 hermetically fixed to the bottom hole of the valve chamber cylinder 11 by welding or the like. The valve body 10 is formed with a valve chamber 13, and an inlet conduit (joint) 41 for introducing a high-pressure refrigerant into the valve chamber 13 is connected to the peripheral side portion, and the bottom portion (the valve seat member 12). ) Is connected to an outlet conduit (joint) 42 for leading out the refrigerant from the valve chamber 13, and further, a base-shaped defining member 32 so as to close the upper surface opening of the valve body 10 (valve chamber cylinder 11). Is hermetically sealed by welding or the like.

  The valve seat member 12 of the main valve 5 is provided with a main valve port 14 with a main valve seat 14a having a conical surface, and the valve seat member 12 in the valve body 10 (valve chamber cylinder 11) is reversely convex in cross section. A letter-shaped piston-type main valve body 20 is slidably inserted, and a back pressure chamber 33 is defined between the main valve body 20 (its large diameter portion 20A) and the defining member 32. ing.

  The main valve body 20 is provided with a main valve portion 21 that contacts and separates from the main valve seat 14a at a lower end portion (small diameter portion 20B), and the large diameter portion 20A of the main valve body 20 includes the valve A small diameter equalizing hole 24 is formed so as to allow the chamber 13 and the back pressure chamber 33 to communicate with each other, and a sealing material 70 is disposed between the large diameter portion 20 </ b> A and the valve chamber cylinder 11.

  The main valve body 20 is always urged in the valve opening direction (upward) by a compression coil spring 25 that is mounted between the lower end surface portion 20a of the large-diameter portion 20A and the valve seat member 12. . Specifically, an undesired behavior of the upper end portion 25a is suppressed on the lower end surface portion 20a (upper spring receiving portion) of the large diameter portion 20A of the main valve body 20 that receives the upper end portion 25a of the compression coil spring 25. Accordingly, a short cylindrical downward projecting portion 20b into which the upper end portion 25a is extrapolated is provided.

  The valve seat member 12 includes a small diameter cylindrical portion 12A in which a main valve port 14 with a main valve seat 14a is formed, a large diameter cylindrical portion 12B in which the outlet conduit (joint) 42 is inserted and connected, A stepped hook-like portion 12C to which the lower end of the valve chamber cylinder 11 is connected, and a stepped surface (upper surface) 12c of the stepped hook-like portion 12C receives the lower end 25b of the compression coil spring 25; In order to suppress an undesired behavior of the lower end portion 25b of the compression coil spring 25, the lower end portion 25b is extrapolated to the small diameter cylindrical portion 12A.

  Further, a pilot passage 28 is formed in the main valve body 20 so as to penetrate the center vertically. More specifically, a pilot valve seat member 22 to which a pilot valve portion 36 provided at a lower end portion of a pilot valve body 35 described later is brought into contact with and separated from is press-fitted and fixed at the center of the upper surface portion of the main valve body 20. The pilot valve seat member 22 is provided with a pilot valve port 27 with a pilot valve seat 27 a, and this pilot valve port 27 is an upper end portion of the pilot passage 28.

  The electric pilot valve 7 provided on the upper side of the main valve 5 includes a stepped needle-like pilot valve body 35 having a pilot valve portion 36 that contacts and separates from the defining member 32 and the pilot valve seat 27a, A can 34 having a lower end sealed and joined to the defining member 32 by welding; a rotor 55 disposed around the inner periphery of the can 34 with a predetermined gap; and rotated around a rotation axis O; And a stator 50 </ b> A that is externally mounted on the can 34 to rotationally drive the rotor 55.

  The stator 50A includes a yoke 51 made of a magnetic material, upper and lower stator coils 53, 53 wound around the yoke 51 via a bobbin 52, and a resin mold cover 56, and is stepped by the rotor 55 and the stator 50A. A motor 50 is configured.

  The can 34 is made of a non-magnetic metal plate such as stainless steel and is formed into a cylindrical shape having a ceiling by deep drawing or the like, and the lower end portion (opening edge portion) of the defining member 32 is The upper stepped portion is sealed and joined by butt welding, and the inside is kept airtight.

  The drive mechanism for bringing the pilot valve body 35 (the pilot valve portion 36) into and out of contact with the pilot valve seat 27a is arranged on a cylindrical guide bush 37 into which the pilot valve body 35 is slidably inserted and its outer periphery. The screw feed mechanism 60 is formed on the cylindrical valve body holder 40 having a lower opening. That is, the lower end portion of the guide bush 37 is press-fitted (or screwed) and fixed to the defining member 32, and a male screw portion 62 is formed in the vicinity of the center portion thereof. A female screw portion (moving screw portion) 61 that is screwed into the male screw portion (fixed screw portion) 62 is formed, and the upper small diameter portion of the pilot valve body 35 is inserted into the center of the nadir so as to be capable of relative rotation and relative movement. I'm hurt. The upper end portion of the upper small-diameter portion of the pilot valve body 35 is press-fitted and fixed to a nut 44 placed on the top surface (concave portion) of the valve body holder 40.

  The pilot valve body 35 is always urged downward by a buffering coil spring 38 that is mounted between the nadir of the valve body holder 40 and the intermediate step portion of the pilot valve body 35. A pressure equalizing hole 37 a for equalizing the pressure in the back pressure chamber 33 and the can 34 is formed on the side surface of the guide bush 37.

  A return spring 45 made of a coil spring is provided on the top of the valve body holder 40. The return spring 45 abuts against the ceiling of the can 34 when the fixed screw portion 62 of the guide bush 37 and the moving screw portion 61 of the valve element holder 40 are unscrewed, and the return spring 45 contacts the ceiling of the can 34. It works to restore the screwing.

  The valve body holder 40 and the rotor 55 are coupled via a support ring 43, and the upper protrusion of the valve body holder 40 is caulked and fixed to the support ring 43, whereby the rotor 55, the support ring 43, and the valve body holder are fixed. 40 are integrally connected.

  A lower stopper body (fixed stopper) 66 constituting one of the stopper mechanisms is fixed to the guide bush 37, and an upper stopper body (moving stopper) 67 constituting the other stopper mechanism is fixed to the valve body holder 40. ing.

  In the present embodiment, the outer diameter Da of the large-diameter portion 20A of the main valve body 20 is 1.5 to 3 times the diameter Db of the main valve port 14, and the outer diameter Dc of the rotor 55. The diameter of the main valve port 14 is 3 to 9 times the diameter of the pilot valve port 27, and the diameter of the pilot valve port 27 is larger than the hole diameter (minimum portion) of the pressure equalizing hole 24. Yes.

  Here, the reason why the outer diameter Da of the large diameter portion 20A of the main valve body 20 is 1.5 to 3 times the diameter Db of the main valve port 14 as described above will be described. That is, the outer diameter Da of the large-diameter portion 20A of the main valve body 20 is illustrated in FIG. 6 such that the opening area of the pilot valve 7 (of the valve port 27) necessary for opening the main valve 5 is illustrated. However, if it is less than about 1.5 times the diameter Db of the main valve port 14, the required opening area of the pilot valve increases steeply as the magnification decreases. This means that a smaller pilot factor requires a larger pilot valve and a larger valve opening driving force. If the magnification exceeds three times, the required opening area of the pilot valve does not become so small. Therefore, even if the magnification is 3 times or more, the size of the pilot valve and the valve opening driving force cannot be reduced so much.

  The diameter of the main valve port 14 is 3 to 9 times the diameter of the pilot valve port 27, so that if the pilot valve 7 with a small diameter is opened, the main valve 5 with a large diameter is opened in response to the opening. Therefore, the large-diameter main valve 5 can be opened and closed with a small driving force.

  In the electric pilot type pilot type control valve 1 of the present embodiment configured as described above, the main valve 5 is in a closed state (as shown in FIGS. 1 and 2, the main valve body 20 The main valve portion 21 is seated on the main valve seat 14a) and the electric pilot valve 7 is open (the pilot valve body 35 is away from the pilot valve seat 27a). For example, when pulses are supplied to the motor 50 (stator coils 53, 53) in the order phase and the rotor 55 is rotated in one direction with respect to the guide bush 37, the fixing screw portion 62 of the guide bush 37 and the valve element holder 40 are By the screw feed with the moving screw portion 61, the valve body holder 40 moves downward, and the pilot valve portion 36 of the pilot valve body 35 is seated and brought into pressure contact with the pilot valve seat 27a to be closed.

  At this time, the upper stopper body 67 is not yet in contact with the lower stopper body 66, and the valve body holder 40 is further rotated and lowered while the pilot valve portion 36 of the pilot valve body 35 is seated on the pilot valve seat 27a. At this time, since the valve body holder 40 is lowered with respect to the pilot valve body 35, the descent force of the valve body holder 40 is absorbed by the compression coil spring 38 being compressed. Thereafter, when the rotor 55 further rotates and the valve body holder 40 is lowered, the upper stopper body 67 comes into contact with the lower stopper body 66 and the valve body holder 40 is lowered even if the pulse supply to the stator coils 53 and 53 is continued. It is forcibly stopped.

  When the main valve 5 and the electric pilot valve 7 are in the closed state (the state shown in FIG. 1) as described above, the high-pressure refrigerant introduced from the inlet conduit 41 into the valve chamber 13 passes through the pressure equalizing hole 24. Since the back pressure chamber 33 becomes high pressure, the main valve portion 21 of the main valve body 20 is strongly pressed against the main valve seat 14a. At this time, the opening degree of the pilot-type control valve 1 = opening area (effective opening area of the main valve opening 14 + effective opening area of the pilot valve opening 27) is represented by opening degree = opening area on the vertical axis and horizontal axis on the horizontal axis. As shown in FIG. 5 where the number of pulses (rotation amount of the rotor 55) is taken, the refrigerant flow rate flowing out from the valve chamber 13 to the outlet conduit 42 becomes zero (0) (the pulse number ranges from 0 to Ta).

  From the time when the main valve 5 and the electric pilot valve 7 are in the closed state (the state shown in FIG. 1), the stepping motor 50 (stator coils 53, 53) is supplied with pulses in, for example, opposite phases, and the rotor 55 is moved. When the guide bush 37 is rotated in the opposite direction, the screw feed between the fixing screw portion 62 of the guide bush 37 and the moving screw portion 61 of the valve body holder 40 as shown in FIGS. When the pulse number (rotation amount) reaches Ta, the pilot valve portion 36 of the pilot valve body 35 begins to move away from the pilot valve seat 27a as the valve body holder 40 moves upward, and the pilot valve 7 begins to open. As shown in FIG. 4, until the number of pulses reaches Tb, the valve opening = the opening area in the pilot type control valve 1 gradually increases slightly, and the refrigerant in the back pressure chamber 33 flows into the pilot passage. Flows out to the outlet conduit 42 through 8, the pressure in the back pressure chamber 33 is gradually reduced.

  When the number of pulses (rotation amount) reaches Tb, as shown in FIG. 2, the pilot valve portion 36 of the pilot valve body 35 is separated from the pilot valve seat 27a by a predetermined distance α and the effective opening area of the pilot valve port 27 is reached. The opening area of the pilot-type control valve 1 is Sa, and the force that pushes up the main valve body 20 (the force that opens the valve) such as the spring force of the compression coil spring 25 is the force that pushes down the main valve body 20 (the force that closes the valve). ), The main valve body 20 is pushed up, the main valve portion 21 begins to move away from the main valve seat 14a, and the main valve 5 begins to open.

  Subsequently, when the number of pulses is further increased, the main valve body 20 is pushed up so as to follow the upward movement of the pilot valve body 35 as shown in FIG. 3 until the number of pulses reaches Tc. Specifically, in a state where the pilot valve portion 36 of the pilot valve body 35 is separated from the pilot valve seat 27a by the predetermined distance α, that is, in a state where the opening degree of the electric pilot valve 7 is kept substantially constant, The body 35 and the main valve body 20 move upward (in the valve opening direction) together. As a result, as shown in FIG. 5, when the number of pulses (rotation amount) is between Tb and Tc, the opening area (opening degree) in the pilot type control valve 1 increases smoothly with a constant gradient. That is, in the present embodiment, until the number of pulses changes from Tb to Tc, the pilot valve portion 35 of the pilot valve body 35 is maintained at a predetermined distance α away from the pilot valve seat 27a, The dimensional specifications and the like of each part are set so that the main valve body 20 rises by the same distance with respect to the number of pulses (rotation amount).

  When the number of pulses reaches Tc, as shown in FIG. 4, the upper surface stopper portion 29 of the main valve body 20 comes into contact with the fixed stopper 39 provided on the lower surface of the defining member 32, and the main valve body 20 The rise is prevented. Therefore, even if the number of pulses exceeds Tc, the valve opening = opening area in the pilot type control valve 1 is not larger than Sb when the number of pulses is Tc, and the opening (maximum opening) at this time Will be maintained.

  As described above, in the pilot type control valve 1 of the present embodiment, the pilot valve is an electrically operated type instead of an electromagnetic type, so that the valve opening degree (opening) depends on the number of pulses supplied to the pilot valve 7. Area) can be changed smoothly, and the pressure equalization time can be shortened. Therefore, the valve opening (opening area) can be arbitrarily and finely adjusted, the generation of noise can be effectively suppressed, and excellent responsiveness, operational stability, control characteristics, etc. can be obtained. . Further, by setting the outer diameter Da of the large diameter portion 20A of the main valve body 20 to 1.5 to 3 times the diameter Db of the main valve port 14, the pilot valve 7 can be made the minimum necessary size, As a result, the power consumption required for opening and closing the valve can be suppressed, the entire valve including the stepping motor 50 can be made compact, and the sliding of the main valve body 20 is more stable. Excellent control characteristics and operational stability can be obtained.

  Next, an example in which the pilot type control valve 1 of the present embodiment is incorporated in a refrigerating cycle of an air conditioner will be described with reference to FIG. Here, in the air conditioner, if the outdoor heat exchanger is frosted during heating, the heating performance is reduced, so defrosting is indispensable for defrosting, but during defrosting, heating operation is not possible, The room temperature decreases and comfort is impaired. In this type of refrigeration cycle, a four-way valve is conventionally used as a flow path switching valve. However, in a normal four-way valve, the compressor is stopped to eliminate the refrigerant noise, and high and low pressure equalization is taken. Since switching from heating to defrost and defrost to heating is performed after that, the switching takes time. Therefore, it is desired to shorten the defrost time including the pressure equalization waiting time. In order to meet such a demand, in the refrigeration cycle 100 shown in FIG. 7, the pilot type control valve 1 of the present embodiment is used instead of the four-way valve. Is used.

  The refrigeration cycle 100 shown in FIG. 7 includes a compressor 110, an indoor heat exchanger 130, an outdoor heat exchanger 150, an electric valve (expansion valve) 140, and the pilot control valve 1 (reference numeral 210, 220) and a three-way valve 160, and the pilot-type control valves 210 and 220 and the three-way valve 160 serve as a four-way valve used in a conventional refrigeration cycle. In the pilot type control valves 210 and 220, the port a and the port b are respectively an inlet conduit (joint) 41 and an outlet conduit (joint) 42 in the pilot type control valve 1 of the embodiment, and a three-way valve. 160 has two inlet ports c and e and an outlet port d (note that the three-way valve 160 itself is not directly related to the present invention, and therefore a detailed description thereof is omitted here. For details of the valve 160, refer to Japanese Patent Application Laid-Open No. 2004-92802 etc. if necessary).

  In the refrigeration cycle 100 shown in FIG. 7, the refrigerant flow during cooling is indicated by solid arrows, and the refrigerant flow during heating is indicated by dashed arrows.

  That is, (1) During heating, the pilot type control valve 210 is opened and the pilot type control valve 220 is closed, so that the port c → port d flow of the three-way valve 160 is established. (2) During the switching 1 from heating to defrost, the pilot type control valve 210 is opened and the pilot type control valve 220 is gradually opened to be fully opened. At this time, the pressure at the port e of the three-way valve 160 rises, the port c and the port e become the same pressure, and port c → port d and port e → port d flow occur. (3) During the switching 2 from heating to defrost, the pilot type control valve 210 is gradually closed and fully closed, and the pilot type control valve 220 is opened. At this time, the pressure at the port c of the three-way valve 160 is lowered, so that the port e → port d flow. (4) During the defrost operation (the refrigerant flow is the same as that for cooling), the pilot type control valve 210 is closed and the pilot type control valve 220 is opened, and the valve is gradually closed and fully closed. (5) In the middle of switching from defrost to heating, the pilot control valve 210 is gradually opened and fully opened, and the pilot control valve 220 is opened. At this time, the pressure of the port c rises, the port e and the port c become the same pressure, and port e → port d and port c → port d flow occur. (6) During switching 2 from defrost to heating, pilot type control valve 210: open, pilot type control valve 220: gradually open and fully open. At this time, the flow of port c → port d occurs as the pressure at port e decreases.

  Thus, by using the pilot type control valve 1 (210, 220) of the above embodiment, the opening and closing of the valve can be arbitrarily adjusted, that is, the opening area = flow rate can be gradually changed. It is possible to switch between heating → defrost and defrost → heating without stopping the operation, and the defrost time in winter can be shortened.

  Next, an improved example of the pilot type control valve 1 shown in FIGS. 1 to 4 will be described with reference to FIGS. 8 (A) and 8 (B). In the pilot-type control valve 1 ′ of the improved example shown in FIG. 8, portions corresponding to the respective portions of the pilot-type control valve 1 are denoted by the same reference numerals, and redundant description is omitted. Will be explained with emphasis.

  The pilot type control valve 1 ′ shown in FIG. 8 is less likely to cause an operation failure by suppressing undesired behavior of the upper end portion 25a and the lower end portion 25b of the compression coil spring 25, compared to the pilot type control valve 1 of the above embodiment. It is a thing.

  That is, in this improved example, the terrace surface portion 12c of the valve seat member 12 is a lower spring receiving portion that receives the lower end portion 25b of the compression coil spring 25, and the lower end portion, as in the above-described embodiment. 25b is extrapolated to the small diameter cylindrical portion 12A ′ of the valve seat member 12 in a predetermined manner (described later) in order to suppress the undesired behavior, and the large diameter portion 20A of the main valve body 20 is In the lower end surface portion 20a (upper spring receiving portion), in order to suppress undesired behavior of the upper end portion 25a of the compression coil spring 25, a downward projecting portion 20b ′ (described later) in which the upper end portion 25a is extrapolated is inserted. The downward projecting portion 20b of the embodiment is provided with a short columnar shape.

  In this improved example, as can be understood by referring to FIG. 8B, the outer peripheral portion of the small-diameter cylindrical portion 12A ′ of the valve seat member 12 into which the lower end portion 25b of the compression coil spring 25 is extrapolated, A male-thread-like portion 12d having a pitch of 2 to 3 is provided as a locking portion for fixing and holding the lower end portion 25b, and the lower end portion 25b is screwed together.

  Further, the downwardly protruding portion 20b 'of the main valve body 20 is provided with a conical surface portion 20c connected to the short cylindrical portion 20d.

  As described above, the male screw-like portion 12d for fixing and holding the lower end portion 25b of the compression coil spring 25 is provided on the outer peripheral portion of the small-diameter cylindrical portion 12A ′ of the valve seat member 12, whereby the lower end portion 25b of the compression coil spring 25 is provided. However, it is difficult to cause undesired behavior such as floating from the terrace surface portion 12c of the valve seat member 12 and coming out of the small diameter cylindrical portion 12A ′. Operation stability, control characteristics, and the like can be obtained, and noise reduction can be achieved.

  Further, since the conical surface portion 20c is provided in the downward projecting portion 20b ′ of the main valve body 20, the upper end portion 25a of the compression coil spring 25 is the lower end surface portion 20a of the large diameter portion 20A of the main valve body 20 ( Even if it rides on the downward projecting portion 20b ′ away from the spring receiving portion), it can be immediately returned to the original lower end surface portion 20a (spring receiving portion), thereby preventing malfunctions more reliably.

It is a longitudinal section showing one embodiment of a pilot type control valve concerning the present invention, and shows a pilot valve: a closed state, and a main valve: a closed state. It is a longitudinal cross-sectional view which is provided for operation | movement description of the pilot type control valve shown by FIG. 1, and has shown the pilot valve: the open state and the main valve: the closed state. It is a longitudinal cross-sectional view which is provided for operation | movement description of the pilot type control valve shown by FIG. 1, and has shown the pilot valve: the open state and the main valve: the open state (small opening degree). It is a longitudinal cross-sectional view used for operation | movement description of the pilot type control valve shown by FIG. 1, and has shown the pilot valve: the open state and the main valve: the open state (maximum opening degree). 2 is a graph provided for explaining the operation of the pilot type control valve shown in FIG. The graph used for description of the opening area of a pilot valve required in order to open a main valve. The circuit diagram which shows the example which incorporated the pilot type control valve shown by FIG. 1 in the refrigerating cycle of an air conditioner. FIGS. 5A and 5B show an improved example of the pilot type control valve shown in FIGS. 1 to 4, wherein FIG. 5A is an overall longitudinal sectional view, and FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pilot type control valve 5 Main valve 7 Electric pilot valve 10 Valve main body 12 Valve seat member 12A Small diameter cylindrical part 12B Large diameter cylindrical part 12C Step saddle-like part 12c Terrace surface part (lower spring receiving part)
12d Male thread (locking part)
13 Valve chamber 14 Main valve port 14a Main valve seat 20 Main valve body 20A Large diameter portion 20B Small diameter portion 20a Lower end surface portion (upper spring receiving portion)
20b downward projecting portion 20c conical surface portion 24 pressure equalizing hole 25 compression coil spring 27 pilot valve port 27a pilot valve seat 28 pilot passage 32 defining member 33 back pressure chamber 35 pilot valve body 40 valve body holder 50 stepping motor 55 rotor

Claims (10)

A pilot type control valve having a main valve and an electric pilot valve,
The main valve includes a valve body in which a valve chamber into which fluid is introduced and led is formed, and a large-diameter portion that is slidably inserted into the valve body and opens and closes a main valve port provided in the valve body. And a piston-type main valve body having a reverse convex shape in cross section having a small-diameter portion,
The motor-operated pilot valve is mounted so as to close an upper surface opening of the valve body and defines a back pressure chamber between the main valve body and a pilot valve provided in the main valve body A pilot valve body for opening and closing the mouth,
The main valve is provided with a pressure equalizing passage communicating the valve chamber and the back pressure chamber, the main valve body is always urged in a valve opening direction by a compression coil spring, and the pilot The main valve body is adapted to move in the valve opening direction so as to follow the movement of the valve body in the valve opening direction ,
The valve body includes a valve chamber cylinder into which the main valve body is slidably fitted, and a valve seat member having a stepped cylindrical portion provided at a lower portion of the valve chamber cylinder, The compression coil spring is interposed between a lower end surface portion with a downward projecting portion provided in a large diameter portion of the main valve body and a terrace surface portion of the valve seat member, and upper and lower end portions thereof are the main valve. Each of which is extrapolated to the downward projecting part of the body and the cylindrical part of the valve seat member,
A pilot type control valve characterized in that the diameter of the main valve port is 3 to 9 times the diameter of the pilot valve port . The pilot type control valve is configured to open and close the pilot valve body by an electric motor, and to open and close the main valve port by the main valve body in response to the pilot valve body,
2. The pilot according to claim 1, wherein the main valve body is configured to move in the valve opening direction so as to follow movement of the pilot valve body in the valve opening direction. Mold control valve. The pilot-type control according to claim 1 or 2 , wherein a seal member is disposed between a large-diameter portion of the main valve body and a valve body inner wall into which the main valve body is inserted. valve.   The pilot type control according to any one of claims 1 to 3, wherein an outer diameter of a large diameter portion of the main valve body is 1.5 to 3 times a diameter of the main valve port. valve. While maintaining the opening degree of the electric pilot valve substantially constant claims 1 to 4, characterized in that the pilot valve body and the main valve body is adapted to move in the valve opening direction together The pilot type control valve according to any one of the above. The electric pilot valve includes a can, a rotor disposed on the inner periphery of the can, a stator externally mounted on the can to rotationally drive the rotor, and between the rotor and the pilot valve body. The pilot type according to any one of claims 1 to 5, further comprising: a drive mechanism that is disposed and moves the pilot valve body in an axial direction by using rotation of the rotor. Control valve.   The pilot type control valve according to claim 6, wherein an outer diameter of the large diameter portion of the main valve body is larger than an outer diameter of the rotor. The pilot type control according to any one of claims 1 to 7 , wherein a locking portion for fixing and holding a lower end portion of the compression coil spring is provided on the cylindrical portion of the valve seat member. valve. The pilot type control valve according to claim 8 , wherein the locking portion is configured by a male threaded portion into which a lower end portion of the compression coil spring is screwed. The pilot type control valve according to any one of claims 1 to 9 , wherein a conical surface portion is provided in a downward projecting portion of the main valve body.

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