JP6505151B2 - Flow control valve - Google Patents

Description

  The present invention relates to a flow control valve suitable for adjusting the flow rate of refrigerant, for example, in a heat pump type cooling and heating system.

  As an example of this kind of flow rate adjustment valve, a valve body provided with a valve chamber and a valve seat (orifice) and a valve body for changing the flow rate of fluid flowing through the valve mouth according to the lift amount from the valve seat A screw feed type elevation drive including a valve shaft provided with an external thread, a bearing member provided with an internal thread, and a stepping motor as described in, for example, Patent Documents 1 to 3 and the like. There is known a motor-operated valve that can be raised and lowered to move in or out of the valve seat by means of a mechanism.

  By the way, when the flow control valve having the above-mentioned configuration is incorporated into, for example, a heat pump type air conditioning system, the valve port is opened to a predetermined opening degree, and the refrigerant flowing into the valve chamber flows from the valve chamber to the valve body and the valve opening. When it flows out through the crevice formed between these, there existed a problem that continuous noise (fluid passage sound) was easy to generate.

  More specifically, the fluid (refrigerant) flowing into the valve port is in a mixed state of gas and liquid (gas-liquid two-phase flow), that is, when bubbles are mixed in the fluid toward the valve port through the valve chamber, the bubbles When the valve passes through the valve port, rapid pressure fluctuation is generated on the inflow side and the outflow side, and the pressure fluctuation generates a large noise. In particular, in a small opening area (an area where the valve opening degree (lift amount of valve body) is small), generally, the flow path of the fluid at the valve port (gap between the valve body and the valve port) is very narrow. Therefore, the influence of air bubbles in the fluid is increased, and the above-mentioned loud noise (fluid passing noise) is more likely to be generated.

  In order to solve such a problem, in the prior art described in Patent Document 4, it is proposed to interpose a member (muffler member) for dividing air bubbles in the fluid into the valve chamber.

JP, 2012-172839, A JP, 2008-101765, A Unexamined-Japanese-Patent No. 2004-289901 JP 2001-289538 A

  By the way, in the large opening area (area where the valve opening degree is large), the flow path of the fluid in the valve port (the gap between the valve body and the valve port) becomes wide, so the above-mentioned large noise (fluid passage) Sound is less likely to be generated, but it becomes more necessary to secure a sufficient flow rate through the valve port.

  In the prior art described in Patent Document 4, the air bubbles in the fluid are broken down and subdivided when passing through the through holes or the reticulated portion provided in the sound deadening member, and in the state of being subdivided, Since it flows into the gap between the valve body and the valve port, when passing through the valve port, rapid pressure fluctuation is not generated on the inflow side and the outflow side, and the above-mentioned noise can be reduced. However, since the muffling member is fixed to the valve main body so as to always divide the inlet side and the outlet side in the valve chamber, the valve opening in the large opening area where it is necessary to secure the flow rate passing through the valve opening There is a problem that the flow of the fluid toward the end is impeded, the pressure loss (pressure loss) becomes large, and it is difficult to obtain an appropriate refrigerant flow rate.

  In addition, in this type of flow control valve, although the improvement of controllability in the small opening area (low flow area) is required in recent years, the controllability in the small opening area is solved while solving the above problems. If it is going to ensure, there existed a possibility that the enlargement of a physique, complication of a structure, cost increase, etc. might be caused.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to reduce noise during passage of fluid (refrigerant) effectively and to reduce pressure loss in a large opening area with a simple configuration. An object of the present invention is to provide a flow control valve capable of improving controllability in a small opening region.

  In order to achieve the above object, the flow control valve according to the present invention basically comprises: a valve main body provided with a valve chamber and a large flow rate valve port; The outer periphery of the lower end portion of the first valve body is changed to change the flow rate of the fluid flowing through the large flow rate valve port according to the valve body, the elevating drive unit for moving the first valve body up and down, and the lift amount. A second valve body slidably inserted onto the first valve body so as to surround the second valve body and driven in conjunction with the elevating operation of the first valve body; The valve chamber via an upper communication passage, a communication space defined around the lower end of the first valve body by the second valve body, and a lower communication passage provided in the second valve body And a small flow passage communicating the high flow rate valve port with the upper communication passage in the small flow passage according to the lift amount. The flow rate of the fluid flowing through the small flow rate valve port provided between the communication space and the communication space is changed, and when the lift amount of the first valve body by the elevation drive unit is equal to or less than a predetermined amount, The small flow control state in which the large flow rate valve port is closed by the second valve body and the flow rate is controlled in accordance with the lift amount of the first valve body with respect to the small flow rate valve port; When the lift amount of the first valve body due to the first valve body exceeds the predetermined amount, the second valve body is raised with the rise of the first valve body, and the second valve body receives the large flow rate valve port. The large flow rate control valve is configured to be in the large flow rate control state to be opened, and the force in the valve closing direction acting on the second valve body in the small flow rate control state is greater than the force in the valve opening direction. The opening area and the pressure receiving area in the vertical direction of the second valve body are set. It is characterized.

  In a preferred aspect, the opening area of the large flow rate valve port and the pressure receiving area in the vertical direction of the second valve body are set to be the same.

  In a further preferred aspect, the opening area of the large flow rate valve port, the pressure receiving area in the vertical direction of the back pressure chamber defined on the back side of the first valve body, and the pressure receiving area in the vertical direction of the second valve body Are set identically, and a pressure equalizing passage connecting the large flow rate valve port and the back pressure chamber is provided.

  In a further preferred aspect, the pressure equalizing passage is configured to include a part or the entire circumference of the valve chamber on the valve body.

  In a further preferred aspect, the pressure equalizing passage includes a gap formed between a base member defining the valve chamber and an outer cylinder disposed outside the base member.

  In another preferable aspect, the muffling in which air bubbles in the fluid flowing through the small flow passage are subdivided in at least one of the small flow passage from the small flow valve opening in the small flow passage and the large flow valve opening side The members are distributed.

  The muffling member is preferably disposed in the upper communication passage and the lower communication passage in the small flow passage.

In another preferred aspect, the second valve body is biased in the valve closing direction of the large flow rate valve port by a biasing member interposed between the second valve body and the first valve body. Rutotomoni, the lift amount of the first valve body is more than the predetermined amount, is adapted to be raised pull the flanged engaging part provided in the first valve body.

  In another preferable aspect, the second valve body is connected to a cylindrical interlocking member slidably inserted at the lower end portion of the first valve body, and the lower end opening of the interlocking member, and the large flow rate It is comprised by the valve body member which opens and closes a valve port.

  In a further preferred aspect, a seal member for sealing between the communication space and the valve chamber is interposed between the lower end portion of the first valve body and the interlocking member.

  In a further preferred aspect, the small flow rate passage flows in the vertical hole in the upper communication passage of the first valve body and / or the vertical hole in the lower communication passage provided in the valve body member of the second valve body. A muffling member is installed to fragment air bubbles in the fluid.

  In a further preferred aspect, the small flow rate valve port is provided in a vertical hole in the upper communication passage of the first valve body.

  In the flow rate adjustment valve according to the present invention, the flow path is provided in the upper communication passage provided in the first valve body, the communication space defined around the lower end of the first valve body by the second valve body, and the second valve body A small flow passage communicating the valve chamber with the large flow rate valve port is formed via the lower communication passage, and air bubbles in the fluid are subdivided when passing through the small flow passage, Noise can be effectively reduced when fluid (refrigerant) passes, particularly when fluid (refrigerant) passes in the small opening (small flow control) region, and pressure loss in the large opening (large flow control) region is suppressed. And an appropriate refrigerant flow rate can be obtained.

  Also, for example, the opening area of the large flow rate valve port and the pressure receiving area in the elevating direction of the second valve body are set to be the same, and in the valve closing state or the small flow rate control state Since the acting force is balanced (differential pressure is canceled), the small opening area (low flow area) at the time of flow control, particularly when the fluid flows in the direction from the large flow rate valve port to the valve chamber Can be improved.

  Further, the opening area of the large flow rate valve port, the pressure receiving area in the vertical direction of the back pressure chamber of the first valve body, and the pressure receiving area in the vertical direction of the second valve body are set to be the same. Pressure equalizing passage that communicates with the back pressure chamber, and the force acting in the moving direction (raising and lowering direction) of the second valve body in the closed state or small flow rate control state is balanced (cancel the differential pressure) In addition to the above, the force acting in the moving direction of the first valve body in the small flow rate control state and the force acting in the moving direction of the first valve body and the second valve body in the large flow rate control state are balanced (cancel the differential pressure) Therefore, in addition to the controllability in the small opening area (low flow area) being improved as described above, the valve body (the first valve body in the small flow control state, the first in the large flow control state) Load acting on the valve body and the second valve body And as small as possible, it is possible to reduce the driving torque of the valve body, has been, further size reduction can reduce power consumption and the like.

  Further, the bubbles in the fluid flowing through the small flow passage are subdivided from the small flow valve port provided between the upper communication passage and the communication space in the small flow passage toward the valve chamber side and the large flow valve opening side. Since the muffling members are disposed, noise at the time of fluid (refrigerant) passage can be reliably reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The whole sectional view showing one embodiment of the flow control valve concerning the present invention. UU arrow sectional drawing of FIG. The principal part sectional view showing the full closing state of the principal part in the flow control valve shown by FIG. The principal part sectional view showing the state (small flow control state) where the lift amount of the principal part in the flow control valve shown in Drawing 1 is small. The principal part sectional view showing the full open state (large flow control state) of the principal part in the flow control valve shown by FIG. The whole sectional view showing the modification (the 1) of the flow control valve shown by FIG. V-V arrow sectional drawing of FIG. The whole sectional view showing the modification (the 2) of the flow control valve shown by FIG. The whole sectional view showing the modification (the 3) of the flow control valve shown by FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall cross-sectional view showing an embodiment of a flow rate adjustment valve according to the present invention, and FIG. 2 is a cross-sectional view taken along the line U-U in FIG.

  In the present specification, descriptions representing positions, directions such as top, bottom, left, right, front, back, etc. are provided for convenience according to the drawings in order to avoid complicated explanation, and the positions, directions in the actual use state Does not necessarily mean

  Further, in each drawing, the gap formed between the members, the separation distance between the members, and the like are large in comparison with the dimensions of the respective constituent members in order to facilitate understanding of the invention and for convenience in drawing. Or it may be drawn small.

<Configuration of Flow Adjustment Valve 1>
The flow control valve 1 of the illustrated embodiment is, for example, a motor-operated valve used to adjust the flow rate of the refrigerant in a heat pump type cooling and heating system etc., and the fluid (refrigerant) is introduced and derived similarly to the conventional flow control valve described above. Valve body 10 having a valve chamber 14 and a valve port (a large flow rate valve port) 16 with a valve seat 15 opened to the valve chamber 14, and a valve base 10 via a stepped cylindrical base 13 A stepping motor (lifting / driving unit) 63 including a bottomed cylindrical can 30 fixed, a stator 40 externally fitted to the can 30, and a rotor 50 rotatably disposed on the inner periphery of the can 30, and a rotor Wonder planetary gear reduction mechanism 60 for reducing the number of rotations of 50 and the passing amount of fluid by controlling the valve seat 15 by contacting and separating (in other words, the fluid flowing through the valve port 16 according to the lift amount from the valve seat 15 Change the flow rate of Rotary motion of the two-stage valve body 32 provided with the sub-valve body (second valve body) 31 and the output gear 57 of the planetary gear reduction mechanism 60 into linear motion to convert the two-stage valve body 32 And a screw feed mechanism 27 for driving (raising and lowering).

The valve body 10 has a bottomed cylindrical base member 9 and an outer cylinder 8 made of, for example, a sheet metal, disposed outside the base member 9, and is formed of a cylindrical cavity inside the base member 9. A valve chamber 14 is defined. At one side of the valve chamber 14 in the base member 9, a lateral side opening 11 is provided, to which the pipe fitting 11a is connected (by brazing or the like) and having an inlet / outlet 17 opening to the valve chamber 14 At the bottom thereof, there is provided a vertically oriented bottom opening 12 having a valve port (orifice) 16 having a cylindrical surface which is connected (by brazing or the like) and opened to the valve chamber 14. Further, the lower portion of a cylindrical holding member 19a of a support member 19 described later is inserted into the upper portion of the valve chamber 14 (in other words, the upper opening of the cylindrical portion 9a of the base member 9), and caulking It is being fixed to the cylindrical base 13) (crimping part 13a).

  The outer cylinder 8 is formed slightly larger in diameter than the cylindrical portion 9 a of the base member 9. The lower half of the bottom 9b of the base member 9 has a slightly larger diameter, and the lower end of the outer cylinder 8 is joined by butt welding or the like to a flange 9c provided on the outer periphery of the larger diameter Thus, the outer cylinder 8 is fixedly disposed on the outer periphery of the base member 9 with a slight gap.

  Further, in this example, D-cut is made on the side of the base member 9 (in the illustrated example, the side opposite to the side opening 11, which corresponds to the upper half of the cylindrical portion 9a and the bottom 9b). A surface 9 d is formed, and a lower passage 7 b formed of a horizontal hole connecting the D-cut surface 9 d and the valve port 16 is formed in the upper half of the bottom 9 b.

  A stepped cylindrical base 13 (the outer peripheral step portion thereof) is joined to the upper end (upper opening) of the outer cylinder 8 by welding or the like, and the upper end of the cylindrical base 13 has a cylindrical shape with a lid. The lower end portion of the can 30 is hermetically joined by butt welding or the like.

  A support member for supporting a two-stage valve body 32 (a main valve body (first valve body) 29) and the like disposed in the internal space so as to be able to move up and down in the internal space defined by the valve body 10 and the can 30 19 are arranged fixed to the valve body 10. The support member 19 has a cylindrical holding member 19a with a partition 19c and a bearing member 19h with an internal thread 19i, and (the central portion of the cylindrical holding member 19a is press-fit and caulked inside the cylindrical base 13) The lower part of the cylindrical holding member 19a (more specifically, the lower end reduced diameter part whose outer diameter is slightly reduced) is fixed to the upper opening of the base member 9 (the cylindrical part 9a of the base member 9). With the O ring 19b inserted). A stepped cylindrical bearing member 19 h having a female screw 19 i screwed downward to the inner peripheral surface is fixed to the upper portion of the cylindrical holding member 19 a by caulking or the like. A spring chamber 19d is defined between the partition wall 19c of the cylindrical holding member 19a and the bearing member 19h, and (the main valve body 29 of) the two-stage valve body 32 is always opened in the spring chamber 19d (upward direction). The valve-opening spring 26 which consists of a compression coiled spring urging | biasing it is accommodated (contraction installation).

  The stator 40 mounted on the outer periphery of the can 30 comprises a yoke 41, a bobbin 42, a coil 43, a resin mold cover 44 and the like, and the rotor 50 rotatably supported within the can 30 (without moving up and down) is A cylindrical rotor member 51 made of a magnetic material and a sun gear member 52 made of a resin material are integrally connected. A shaft 62 is inserted into the central portion of the sun gear member 52, and the upper portion of the shaft 62 is supported by a support member 61 disposed inside the top of the can 30.

  The sun gear 53 of the sun gear member 52 meshes with a plurality of planet gears 55 rotatably supported by a shaft 56 provided on a carrier 54 mounted on the bottom surface of the output gear 57. The upper half of the planetary gear 55 meshes with an annular ring gear (internal gear fixed gear) 58 attached by caulking to the upper end of the cylindrical member 18 fixed to the upper portion of the cylindrical holding member 19a. Is meshed with the internal gear 57 a of the annular output gear 57. The number of teeth of the ring gear 58 and the number of teeth of the internal gear 57a of the output gear 57 are slightly different, whereby the rotational speed of the sun gear 53 is reduced at a large reduction ratio and transmitted to the output gear 57. (A gear arrangement such as this is called a so-called strange planetary gear reduction mechanism 60).

  The output gear 57 is in sliding contact with the upper surface of the cylindrical bearing member 19 h, and the upper portion of the stepped cylindrical output shaft 59 is press-fitted at the center of the bottom of the output gear 57. Is rotatably inserted into a fitting insertion hole 19g formed in the upper half of the central portion of the bearing member 19h. The lower portion of the shaft 62 is fitted to the upper portion of the output shaft 59.

  An external thread 22i provided on a screw driving member (also referred to as a driver) 22 (an outer periphery of the bearing 22) is screwed with the internal thread 19i provided on (the inner circumference of) the bearing 19h. 22 converts the rotational movement of the output gear 57 (i.e., the rotor 50) into linear movement in the direction of the axis O (raising and lowering direction) by means of a screw feed mechanism 27 comprising an external thread 22i and an internal thread 19i. Here, the output gear 57 is rotationally moved at a fixed position in the direction of the axis O without moving up and down, and is screw-driven in a slit-like fitting groove 59a provided in the lower portion of the output shaft 59 connected to the output gear 57. A flat driver-shaped plate-like portion 22a provided at the upper end of the member 22 is inserted to transmit the rotational movement of the output gear 57 to the screw drive member 22 side. When the output gear 57 (rotor 50) rotates by the plate-like portion 22a provided on the screw drive member 22 sliding in the direction of the axis O within the fitting groove 59a of the output shaft 59, the output gear 57 rotates The screw drive member 22 linearly moves in the direction of the axis O by the screw feed mechanism 27 despite the fact that it does not move in the axial direction. The linear motion of the screw drive member 22 is stepped shaft-like through a ball joint 25 comprising a ball 23 and a ball seat 24 fitted in a stepped fitting hole provided in the upper center of the thrust transmission shaft 28. Is transmitted to the thrust transmission shaft 28 of FIG.

  The thrust transmission shaft 28 is slidably inserted from the top into the insertion hole formed in the large diameter upper portion 28a in which the stepped fitting hole is formed in the center and the partition wall 19c of the cylindrical holding member 19a. The upper portion (fitting hole 29d consisting of a central hole 29v) of the main valve body 29 consisting of a cylindrical body is formed into the small diameter lower portion 28c which is composed of a body portion 28b and the intermediate body portion 28b. The main valve body 29 and the thrust transmission shaft 28 are integrally raised and lowered. The main valve body 29 connected to (the small diameter lower portion 28c of) the thrust transmission shaft 28 is slidably inserted in the lower portion of the cylindrical holding member 19a fixed inside the valve body 10, and the cylindrical shape It is guided by the holding member 19a and moved in the direction of the axis O. That is, the lower inner periphery (inner peripheral portion below the partition wall 19c) of the cylindrical holding member 19a is a valve guide hole 19f for guiding the main valve 29 in the direction of the axis O (raising and lowering direction).

  A pressing member 29f is sandwiched and fixed between the upper end surface of the main valve body 29 and the lower end step portion of the intermediate body portion 28b of the thrust transmission shaft 28 at the time of press fitting of the small diameter lower portion 28c. An O-ring 29h as a sealing member is mounted between the annular groove formed in the upper end portion of the main valve body 29 and the valve body guide hole 19f, and the valve body guide hole outside the O ring 29h. In order to reduce the sliding resistance of the main valve body 29 with respect to 19f, a ring-shaped packing (also referred to as a cap seal) 29i made of Teflon (registered trademark) or the like is attached.

  Further, the valve opening spring 26 disposed in the spring chamber 19 d above the partition wall 19 c of the cylindrical holding member 19 a is disposed in a state where its lower end is in contact with the partition wall 19 c. In order to transmit the biasing force (pulling-up force) to the main valve body 29 via the thrust transmission shaft 28, a pulling-up spring receiving body 20 having hook-like hooking portions 20a and 20b vertically is disposed. The upper hooking portion 20 a of the pull-up spring receiver 20 is placed on the upper portion of the valve opening spring 26, and the lower hooking portion 20 b is hooked on the lower end step portion of the large diameter upper portion 28 a of the thrust transmission shaft 28.

  Further, the cylindrical holding member 19a is formed with a communication hole 19e for communicating the spring chamber 19d with the inside of the can 30, and the caulking portion on the upper side of (the upper end portion of) the base member 9 in the cylindrical holding member 19a. In the lower part of 13a, the back pressure chamber 21 which is the space above the main valve body 29 in the valve body guide hole 19f (more specifically, the valve body guide hole 19f, in other words, the main valve body 29 and the cylindrical An upper passage 7a is formed which is a horizontal hole connecting the space defined between the holding member 19a with the partition 19c and the outside of the cylindrical holding member 19a.

  The lower passage 7b provided in the bottom 9b of the base member 9 of the valve main body 10 described above, the D-cut surface 9d of the base member 9 and the outer peripheral surface of the cylindrical holding member 19a and the inner wall surface of the outer cylinder 8 Above the valve port 16 and the main valve body 29 (the back side with respect to the valve chamber 14) by the vertical passage 6 consisting of a gap formed between them and the upper passage 7a provided in the cylindrical holding member 19a. The pressure equalizing passage 5 is in constant communication with the back pressure chamber 21 defined therein (described in detail later).

  As described above, the lower portion (lower end reduced diameter portion) of the cylindrical holding member 19a is internally fitted in the upper opening of the base member 9 (the cylindrical portion 9a thereof), and the lower opening of the cylindrical holding member 19a (valve guide hole By inserting the main valve body 29 into 19f), the valve chamber 14 is defined below the cylindrical holding member 19a in the inside of the base member 9. The lower portion of the main valve body 29 connected to the thrust transmission shaft 28 protrudes from the valve body guide hole 19f of the cylindrical holding member 19a toward the valve chamber 14 and is disposed in the valve chamber 14 so as to be movable up and down. In addition, a substantially concave auxiliary valve body (second valve body) 31 is slidably inserted on the main valve body 29 so as to surround the outer periphery of the lower end portion of the main valve body 29.

  In detail, as can be understood well with reference to FIGS. 3A to 3C together with FIG. 1, the upper half of the central hole (longitudinal hole) 29v of the main valve body 29 consisting of the above-mentioned cylindrical body has a small diameter of the thrust transmission shaft 28. The lower portion 28c is a fitting hole 29d to be fitted and fixed, and a plurality of relatively small diameter lateral holes 29u are formed laterally from the middle part of the central hole 29v (in other words, immediately below the fitting hole 29d) ing. The inner periphery of the lower end portion of the central hole 29v is slightly reduced in diameter, and the inner peripheral surface (cylindrical surface) of the lower end reduced diameter portion 29a is an upper valve body formed at the upper end portion of the sub valve body 31 described later. The portion 37f) is a valve port (small flow rate valve port) 29c with a valve seat 29b which is opened and closed by contacting and separating. As described above, the upper half (upper opening) of the central hole 29v of the main valve body 29 is closed by the small diameter lower portion 28c of the thrust transmission shaft 28, and the lower half of the central hole 29v (thrust transmission shaft 28 The space defined between the main valve body 29 and the sub valve body 31 (in other words, the sub valve body 31) by the lateral hole 29 u) and the lateral hole 29 u below the fitting hole 29 d in which the small diameter lower portion 28 c is fitted and fixed A communication passage (upper communication passage) 33a communicating with the communication space 34 consisting of the space defined by the valve body 31 and the space defined around the lower end of the main valve body 29 and the valve chamber 14 is formed.

  Further, the lower end outer periphery of the main valve body 29 is slightly extended toward the lower side, and the lower end outer periphery (an extending portion) of the main valve body 29 is an interlocking member 36 of the sub valve body 31 described later. A hook-shaped locking portion 29g engaged with (an inner hook-shaped locking portion 36g formed on the inner periphery thereof) is provided so as to protrude (toward the outside).

  On the other hand, the auxiliary valve body 31 disposed on the outer periphery of the lower end portion of the main valve body 29 has a cylindrical interlocking member 36 slidably extrapolated to the lower end portion of the main valve body 29 and the lower end of the interlocking member 36 A space constituted by the stepped valve body member 37 connected to the opening and defined by the sub valve body 31 (the interlocking member 36 and the valve body member 37) around the lower end portion of the main valve body 29 is communicated It is a space 34.

  A step is formed on the inner periphery of the interlocking member 36, and (the downward surface of) the inner periphery stepped portion engages with the hook-shaped locking portion 29 g provided on the lower end portion of the main valve body 29. The hook-shaped locking portion 36g is used. Between the lower end portion of the main valve body 29 and the interlocking member 36 of the sub-valve body 31 (upper portion than the inner hook-shaped locking portion 36g) (specifically, an annular formed on the inner periphery of the interlocking member 36) An O-ring 38 as a sealing member for airtightly sealing between the communication space 34 and the valve chamber 14 (sliding surface gap between the main valve body 29 and the interlocking member 36 of the sub valve body 31). Is attached. The lower end portion of the interlocking member 36 is fixed by welding, press fitting, caulking, or the like to a brim portion 37 c provided on the outer peripheral portion of (the lower large diameter portion 37 a of) the valve body member 37.

  The valve body member 37 connected to the interlocking member 36 basically has a lower large diameter portion 37a having a diameter larger than that of the valve port (large flow rate valve port) 16, and an extension portion of the lower end outer periphery of the main valve body 29. The upper small diameter portion 37b is slightly smaller in diameter and slightly larger in diameter than the central hole 29v.

  The lower end face of (the lower large diameter portion 37a of) the valve body member 37 is a lower valve body portion (a large flow rate formed by an inverted frusto-conical surface that opens and closes the valve port 16 by coming into contact with and separating from the valve seat 15 of the valve main body 10 Valve body portion 37d. Further, in the valve member 37, a stepped central hole (longitudinal hole) having a relatively large diameter in the vertical direction (axis O direction) from the center of the lower end surface of the lower large diameter portion 37a to the upper end surface near the upper small diameter portion 37b. A 37v is formed, and a plurality of relatively small diameter side holes 37u are formed laterally from the upper portion of the center hole 37v (the middle part of the upper small diameter portion 37b). The central hole 37v and the lateral hole 37u form a communication passage (lower communication passage) 33b for always communicating the valve port 16 with the communication space 34.

  Further, a substantially truncated cone-shaped projecting surface is formed on the upper end surface of (the upper small diameter portion 37b of) the valve body member 37, and the projecting surface (in particular, the side portion of the projecting surface) is the main valve body Upper valve body (small flow rate valve) that opens and closes the valve port (small flow rate valve port) 29c by coming into contact with and separating from the valve seat 29b formed in the lower end portion (lower end reduced diameter portion 29a) of 29 (from the lower side) Department) 37f.

That is, in this example, is formed between the communication path (the lower communication passage) 33b provided in the sub-valve body 31 described above (the valve member 37), and the main valve body 29 and the sub-valve body 31 The communication space 34 and the communication passage (upper communication passage) 33 a provided in the main valve body 29 form a small flow passage 35 communicating the valve port 16 with the valve chamber 14, and communicates with the communication space 34. A cylindrical surface having a diameter smaller than that of the valve port (large flow rate valve port) 16 of the valve main body 10 between the passage (upper communication path) 33a and the sub valve body 31 (upper small diameter portion 37b of the valve body member 37) upper end face formed on an upper valve body the valve port of the valve seat 29 with b being opened and closed by 37f of (small flow rate valve port) 29c is formed. Then, lift the upper valve body portion 37f of the auxiliary valve body 31 from the valve seat 29 b (i.e., the vertical direction of the separation quantity) flow rate of the fluid flowing through the valve port 29c in the small flow passage 35 in accordance with the (throughput) Will be changed (more on this later).

Here, the hook-shaped locking portion 29g provided on the main valve body 29 and the inner hook-shaped locking portion 36g provided on (the interlocking member 36 of) the sub valve body 31 are the upper valve body of the sub valve body 31. when the part 37f is valve port 29c is closed (in other words, when the upper valve body portion 37f of the auxiliary valve element 31 is seated on the valve seat 29 b), the predetermined dimension in the axial O direction (vertical direction) of the gap La It is set to have (detailed later).

  Further, between the main valve body 29 and the sub valve body 31 constituting the two-stage valve body 32, more specifically, around the central hole 29v in the bottom surface of the main valve body 29 (in other words, around the lower end diameter reducing portion 29a And the lower spring receiver 37e formed of an annular recessed surface formed around the upper small diameter portion 37b on the upper surface of the lower large diameter portion 37a of the valve member 37. In the meantime, a valve closing spring (biasing member) 39, which is a compression coil spring that normally biases the sub valve body 31 in the valve closing direction (downward), is contracted.

  In addition to the above configuration, in the present embodiment, in order to reliably fragment air bubbles in the fluid (in the fluid flowing through the small flow rate passage), the communication passage (upper communication passage) 33a of the main valve body 29 has a substantially cylindrical shape. And the communication passage (lower communication passage) 33b of the valve member 37 of the sub valve body 31 is a substantially cylindrical metal. A muffling member (valve port 16 side muffling member) 72 made of mesh or the like is provided.

  More specifically, the noise reduction member 71 is a central hole (vertical hole) 29v in the communication passage 33a, and more specifically, a lower end portion and a lower end reduced diameter portion 29a of the small diameter lower portion 28c of the thrust transmission shaft 28 fitted in the fitting hole 29d. It is internally fixed and supported. Further, the muffling member 72 is internally installed in the central hole (vertical hole) 37v in the communication path 33b, and a pressing plate (for example, four) having through holes 73a at the lower end of the central hole 37v. The support member 73 is supported and fixed in the central hole 37v by being fixed by caulking or the like.

  Here, as the sound deadening members 71 and 72, a metal mesh (mesh member) having a plurality of small holes is formed into a cylindrical shape, a plate-like metal mesh is laminated to form a cylindrical shape, or a plate A cylindrical metal mesh is used to form a cylindrical shape, but if the air bubbles in the fluid can be subdivided, for example, the muffling members 71 and 72 may be made of resin, or the muffling member 71, 72 itself may be formed of a cylindrical porous body. Moreover, it is needless to say that the fixing method and the like of the sound deadening members 71 and 72 are not limited to the illustrated example.

  Moreover, in the present embodiment, in the valve closed state, the balance between the push-down force (force acting in the valve-closing direction) and the push-up force (force acting in the valve-opening direction) In order to cancel the differential pressure, the valve port 16 and the main through the pressure equalizing passage 5 (the lower passage 7b, the vertical passage 6, and the upper passage 7a) provided in (the outside of the valve chamber 14 of) the aforementioned valve body 10 The back pressure chamber 21 on the upper side of the valve body 29 is in constant communication, the bore diameter D2 of the valve port 16 and the pressure receiving diameter of the sub valve body 31 mounted on the main valve body 29 (from the fluid in the valve chamber 14 The diameter of the back pressure chamber 21 on the upper side of the main valve body 29 (that is, the inside diameter of the valve body guide hole 19f) φD3 is set to be substantially the same (described later in detail).

In the flow rate adjusting valve 1 having such a configuration, the fluid (refrigerant) is bidirectional (in the direction from the side opening 11 toward the bottom opening 12 (horizontal → down) and in the direction from the bottom opening 12 toward the side opening 11 (down → And the amount of rotation of the rotor 50 of the stepping motor 63 mounted above the valve body 10 is controlled to make the two-stage valve body 32 (the main valve body 29 The passing flow rate of the fluid (refrigerant) is adjusted by changing the lift amount L of.

<Operation of Flow Adjustment Valve 1>
The operation of the flow rate adjusting valve 1 configured as described above will be described with reference to FIGS. 3A to 3C and the like.

  In addition, since the operation itself of the flow control valve 1 is basically the same in the flow direction of the fluid (refrigerant), the influence of the differential pressure on the controllability in the small opening region (low flow region) will be described below. A description will be given representatively of the case of increasing the size of the lower → lateral flow.

  In the fully closed state (the lift amount L of the second stage valve body 32 is 0) as shown in FIG. 3A, the upper valve body portion 37f of (the valve body member 37 of) the sub valve body 31 is the main valve body 29. The valve seat 29b is press-contacted (seated) to close the valve port 29c, and the lower valve body portion 37d of (the valve member 37 of the sub valve body 31) is press-contacted (seated) to the valve seat 15 of the valve main body 10 The valve port 16 is closed. At this time, (the upper surface of) the hook-shaped locking portion 29g of the main valve body 29 and (the lower surface of) the inner hook-shaped locking portion 36g of (the interlocking member 36 of the sub valve body 31) And the gap La of a predetermined size.

Here, the pressure of the side apertures 11 side of the fluid (refrigerant) P1, the pressure of the bottom opening 12 side of the fluid (refrigerant) P2, the spring force of the valve closing spring 39 (biasing force) and F, the sub-valve The pressure receiving area corresponding to the pressure receiving diameter φD1 of the body 31 is A1 (in the raising and lowering direction), the opening area corresponding to the diameter φ2 of the valve port 16 is A2, and the receiving pressure corresponding to the chamber diameter φD3 of the back pressure chamber 21 (in the raising and lowering direction) Assuming that the area is A3 and the opening area corresponding to the bore diameter Ds of the valve port 29c is As, the forces in the valve opening direction and the valve closing direction acting on the sub valve body 31 in this fully closed state are as follows.
[Equation 1]
Force in the valve opening direction = P2 × A2
Force in the valve closing direction = F + P1 x As + P1 x (A2-A1) + P2 x (A1-As)

  In order to close the valve port 29c by the sub valve body 31, it is sufficient if the force in the valve closing direction acting on the sub valve body 31 is greater than the force in the valve opening direction, but in the present embodiment, as described above The diameter φD2 of the valve port 16 and the pressure receiving diameter φD1 of the sub valve body 31 are substantially equal, and the opening area A2 of the valve port 16 and the pressure receiving area A1 (in the elevation direction) of the sub valve body 31 are substantially the same. Therefore, in this closed state, the push-up force (force in the valve opening direction) acting on the sub valve body 31 and the push-down force (force in the valve close direction) are balanced (cancel the differential pressure). Here, when P2 is larger than P1, the force in the valve opening direction is considered to increase in accordance with the area of the opening area As, but the unbalance due to the influence of the opening area As is a spring of the valve closing spring 39. The value of force F can be adjusted to balance. Therefore, even when the main valve body 29 is raised in the following small flow control state, the sub valve body 31 can be pushed up by the fluid pressure (the pressure of the fluid flowing from the valve port 16 toward the valve chamber 14) Absent.

  Although described later, even if the pressure receiving area A1 and the opening area A2 are set not to be substantially the same, if the force in the valve closing direction acting on the sub valve body 31 is equal to or more than the force in the valve opening direction, The secondary valve body 31 can be prevented from being pushed up by fluid pressure.

When the main valve body 29 of the two-stage valve body 32 is raised in the fully closed state, as shown in FIG. 3B, up to the gap (lift amount) La of the predetermined dimension (small flow rate control state) The lower end portion of the main valve body 29 is in a state where the lower valve body portion 37b of the body 31 (the valve body member 37) is in pressure contact (seated) with the valve seat 15 of the valve body 10 by (the biasing force) The main valve body 29 is moved (raised) so as to slide in the interlocking member 36 of the sub valve body 31, and the upper valve body portion 37 f of (the valve body member 37 of) the sub valve body 31 is the main valve body 29. The valve port 29c is opened apart from the valve seat 29b. Fluid flowing from the bottom opening 12 (the valve port 16), the communication passage (lower communication passage) of the valve body member 37 of the sub-valve body 31 33 b (center hole 37v, lateral hole 37u) (in particular, the communication passage 33 gap → the main valve element between the valve seat 29b of the upper valve body portion 37f and the main valve body 29 of the through hole 73a) → the communication space 34 → the sub-valve element 31 of the pressing plate 73 which is fixed to b of the central hole 37v It flows into the valve chamber 14 via the 29 communication passages (upper communication passages) 33a (central hole 29v, lateral hole 29u). The flow rate of the fluid flowing into the valve chamber 14 (that is, the fluid flowing out to the side opening 11) gradually increases as the main valve body 29 rises. At this time, the fluid which has flowed in from the bottom opening 12 passes through the muffling member 72 (when passing through the central hole 37v of the communication passage 33b of the valve member 37 of the sub valve member 31). When passing through the center hole 29v of the passage 33a), the two muffling members 72 and 71 which pass through the muffling member 71 and are disposed on the upstream side (valve port 16 side) and the downstream side (valve chamber 14 side) from the valve port 29c. Thus, the air bubbles in the fluid are broken down and divided, and the air passes through the valve chamber 14 (side opening 11). Therefore, in the small flow rate control area (area where noise is likely to occur), the noise when passing the fluid (refrigerant) is reliably reduced.

  Further, in the present embodiment, as described above, the chamber diameter φD3 of the back pressure chamber 21 and the pressure receiving diameter φD1 of the sub valve body 31 are substantially equal, and the back pressure chamber 21 of the main valve body 29 (in the elevating direction) The pressure receiving area A3 and the pressure receiving area A1 (in the raising and lowering direction) of the sub valve body 31 are set to be substantially the same, and the pressure opening passage 5 (lower passage 7b, vertical passage 6, upper passage 7a) More specifically, since the communication space 34 side communicating with the valve port 16 and the back pressure chamber 21 side are constantly communicated and pressure-equalized, they act on the main valve body 29 in this small flow control state. The depressing force (force acting in the valve closing direction) and the lifting force (force acting in the valve opening direction) are balanced (cancel the differential pressure).

  The lift amount La is a lift amount L of the main valve body 29 corresponding to a flow rate at which noise (fluid passing noise) tends to occur when fluid (refrigerant) passes, and can be determined in advance based on experiments and the like.

After raising the main valve body 29 to the lift amount La, when the main valve body 29 is further raised (in other words, the lift amount L exceeds the lift amount La), as shown in FIG. stopper portion 29g is engaged with the inner collar-like locking portion 36g of the sub-valve body 31 (interlocking member 36), sub-valve body 31 is primarily with the valve body 29 (integrally) move (rise) is brought, sub The lower valve body portion 37b of (the valve body member 37 of) the valve body 31 is separated from the valve seat 15 of the valve main body 10, and the lower valve body portion 37b of the (valve body member 37 of the sub valve body 31) A gap (annular flow passage) of a width Lb (= L-La) (in the direction of the axis O) is formed between the seat 15 (large flow control state). The fluid that has flowed into (the valve port 16 of) the bottom opening 12 passes through the gap between the lower valve body 37 b of the sub valve body 31 (the valve body member 37) and the valve seat 15 of the valve body 10. The flow rate of the fluid flowing into the valve chamber 14 gradually increases with the rising of the main valve body 29 (and the sub valve body 31). At this time, (most part of) the fluid flowing in from (the valve port 16 of) the bottom opening 12 is the lower valve body portion 37 b of (the valve body member 37 of) the sub valve body 31 and the valve seat 15 of the valve main body 10 It will flow directly into the valve chamber 14 (side opening 11) through the gap (flow passage) formed between the two. Therefore, the pressure loss (pressure loss) is reduced in a large flow control region where the lift amount L of the main valve body 29 is relatively large (a region where noise is less likely to occur and it is desired to secure the flow rate).

  Further, in the present embodiment, as described above, the bore diameter φD2 of the valve port 16 and the chamber diameter φD3 of the back pressure chamber 21 are substantially equal, and the opening area A2 of the valve port 16 and the back pressure chamber 21 of the main valve body 29. The pressure receiving area A3 (in the elevating direction) is set to be substantially the same, and the valve port 16 side and the back pressure chamber 21 side are always maintained by the pressure equalizing passage 5 (the lower passage 7b, the vertical passage 6, and the upper passage 7a). Since communication and pressure equalization are performed, in this large flow rate control state, the pressing force (valve closing direction) acting on the two-stage valve body 32 (the main valve body 29 and the sub valve body 31 moving integrally) is Force) and push-up force (force in the valve opening direction) are balanced (differential pressure is canceled).

  In the case where the two-stage valve body 32 (the main valve body 29 thereof) is lowered from the fully open state as shown in FIG. 3C and the flow rate of the fluid flowing into the valve chamber 14 gradually decreases, It goes without saying that you can get

<Effect of flow rate adjustment valve 1>
Thus, in the flow control valve 1 of the present embodiment, the lower end portion of the main valve body 29 is defined by the communication passage (upper communication passage) 33 a provided in the main valve body 29 and the sub valve body 31. A small flow passage 35 communicating the valve chamber 14 with the valve port 16 is formed through the communication space 34 and the communication passage (lower communication passage) 33b provided in the sub valve body 31, and air bubbles in the fluid are formed. Since noise is divided when passing through the low flow rate passage 35, noise is effectively reduced when passing through the fluid (refrigerant), particularly when passing through the fluid (refrigerant) in the small opening (small flow rate control) region. While being able to be performed, the pressure loss in the large opening (large flow control) region is suppressed, and an appropriate refrigerant flow rate can be obtained.

  Further, the fluid flowing in the small flow passage 35 from the valve port 29 c provided between the communication passage (upper communication passage) 33 a in the small flow passage 35 and the communication space 34 to the valve chamber 14 side and the valve opening 16 side. Since the muffling members 71 and 72 for dividing the air bubbles inside are disposed, noise at the time of fluid (refrigerant) passage can be reliably reduced.

  Further, the bore diameter φD2 of the valve port 16 and the pressure receiving diameter φD1 of the sub valve body 31 are equalized, and the opening area A2 of the valve port 16 and the lifting and lowering direction of the sub valve body 31 (that is, The pressure receiving area A1 is set to be the same, and the force acting in the moving direction (raising and lowering direction) of the sub valve body 31 in the closed state or small flow rate control state is balanced (cancels the differential pressure). At the time of flow control, in particular, controllability in a small opening region (low flow region) at the time of flow control when fluid flows from the valve port 16 toward the valve chamber 14 can be improved.

  Further, the bore diameter D2 of the valve port 16, the chamber diameter φD3 of the back pressure chamber 21, and the pressure receiving diameter φD1 of the sub valve body 31 are equalized, and the opening area A2 of the valve port 16 and the back pressure chamber 21 of the main valve body 29 are raised and lowered. The pressure receiving area A3 in the direction and the pressure receiving area A1 in the vertical direction of the sub valve body 31 are set equal, and a pressure equalizing passage 5 communicating the valve port 16 with the back pressure chamber 21 is provided. The force acting in the moving direction (up and down direction) of the sub valve body 31 in the small flow rate control state acts in the moving direction of the main valve body 29 in the small flow rate control state in addition to the balance The force acting in the moving direction of the two-stage valve body 32 (the main valve body 29 and the sub valve body 31 moving integrally as one unit) in the force or large flow control state can be balanced (cancel the differential pressure). Small opening area (low flow area In addition to the ability to improve controllability in the valve, the load acting on the valve body (the main valve body 29 in the small flow control state, the two-stage valve body 32 in the large flow control state) at the time of flow control is reduced as much as possible. The drive torque of the valve body can be reduced, whereby further downsizing, power saving, and the like can be achieved.

<Modified Embodiment of Flow Adjustment Valve 1 (Part 1)>
In the above embodiment, the D cut surface 9d is formed on (a part of) the outer periphery of the base member 9 constituting the valve main body 10, and the pressure equalizing passage 5 (of the base member 9 and the outer cylinder 8) is formed. Although the vertical passage 6) is formed, the entire outer periphery of the base member 9 is thinned as in the flow rate adjusting valve 1A shown in FIGS. 4 and 5, for example. The pressure equalizing passage 5 may be formed with a relatively large gap (cylindrical gap).

<Modified Embodiment of Flow Adjustment Valve 1 (Part 2)>
Further, in the above embodiment (flow control valves 1 and 1A), the pressure equalizing passage 5 always connects the valve port 16 and the back pressure chamber 21 on the upper side of the main valve body 29 outside the valve chamber 14 in the valve main body 10. Although the lower passage 7b, the vertical passage 6, and the upper passage 7a are formed, the pressure equalizing passage may be omitted as in the flow rate adjusting valve 1B shown in FIG. 6, for example. In addition, in FIG. 6, the same code | symbol is attached | subjected to the structure which has the function and effect similar to the said embodiment (for the detailed structure, also refer the said patent document 2 collectively).

  In the flow rate adjusting valve 1B having such a configuration, the valve body (the main valve body 29 in the small flow rate control state, the two-stage valve body 32 in the large flow rate control state) acts at the time of flow rate control. Load may increase, but the force acting in the moving direction (raising and lowering direction) of the sub valve body 31 in the closed state or small flow rate control state is balanced (differential pressure is canceled), so low cost The controllability in the small opening region (low flow region) can be secured.

<Modified Embodiment of Flow Adjustment Valve 1 (Part 3)>
Further, in the above embodiment (flow control valves 1, 1A, 1B), although the wonder planetary gear reduction mechanism 60 for reducing the rotational speed of the rotor 50 is used, for example, the flow control valve 1C shown in FIG. As described above, the wonder planet gear reduction mechanism is omitted, the bellows 28C is attached to the outer periphery of the thrust transmission shaft 28, and the outer periphery of the main valve body 29 connected to the lower portion of the thrust transmission shaft 28 (valve body defining the valve chamber 14 A communication passage (in the example shown in FIG. 7, a vertical direction extending in the direction of the axis O in the example shown in FIG. 7) which communicates the valve chamber 14 and the bellows chamber 21C in which the bellows 28C is disposed on the sliding surface with the inner wall surface of 10). A communication passage 29C formed of a groove may be formed. In addition, in FIG. 7, the same code | symbol is attached | subjected to the structure which has the function and effect similar to the said embodiment (for the detailed structure, also refer the said patent document 3 collectively). It is needless to say that the flow control valve 1C having such a configuration can obtain substantially the same function and effect as the flow control valve 1B of the embodiment shown in FIG. 6 described above.

  In each of the above-described embodiments, the opening area A2 of the valve port 16 and the pressure receiving area A1 (in the raising and lowering direction) of the sub valve body 31 are set to be substantially the same. The force in the valve direction) and the depression force (force in the valve closing direction) are balanced (cancel the differential pressure), but the force in the valve closing direction acting on the sub valve body 31 is equal to the force in the valve opening direction If each value of the above-mentioned A1, A2, As, and F is set so that it may become above, when the main valve body 29 is raised at least in the small flow control state, the sub valve body 31 will be fluid pressure (valve opening The pressure of the fluid flowing in the direction from the point 16 toward the valve chamber 14 can prevent the pressure from being pushed up. Thus, controllability in the small opening region (low flow region) can be secured, and noise at the time of fluid (refrigerant) passage can be reduced.

  In order to ensure that the force in the valve closing direction acting on the sub valve body 31 is equal to or greater than the force in the valve opening direction, first, A2 and As are set to ensure the necessary flow rate, and The values of A1 and F may be set so that the force in the valve closing direction acting on the valve body 31 is equal to or greater than the force in the valve opening direction.

  Further, according to the present invention, the valve shaft is vertically moved (moved) using a stepping motor or the like having a stator and a rotor as described in the above embodiment, and the lift amount (valve opening degree) is arbitrarily finely adjusted. It goes without saying that the present invention can also be applied to an electromagnetic flow control (switching) valve using, for example, a solenoid or the like other than the electric flow control valve.

Reference Signs List 1 flow control valve 5 pressure equalizing passage 6 vertical passage 7a upper passage 7b lower passage 8 outer cylinder 9 base member 9a cylindrical portion 9b bottom 9d D cut surface 10 valve main body 14 valve chamber 15 valve seat 16 valve port (large flow valve opening )
17 inlet / outlet 21 back pressure chamber 29 main valve body (first valve body)
29b Valve seat 29c Valve port (for small flow rate)
29d fitting hole 29g hook shaped locking part 29u horizontal hole 29v central hole (vertical hole)
30 can 31 sub valve body (second valve body)
32 two-step valve body 33a communication passage (upper communication passage)
33b Communication passage (lower communication passage)
34 communicating space 35 small flow rate passage 36 interlocking member 36g inner hook shaped locking portion 37 valve body member 37a lower large diameter portion 37b upper small diameter portion 37d lower valve body portion 37f upper valve body portion 37u lateral hole 37v central hole (vertical hole)
38 O-ring (seal member)
39 Valve closing spring (biasing member)
40 Stator 50 Rotor 60 Wonder planetary gear reduction mechanism 63 Stepping motor (lifting and lowering drive)
71 Muffler (valve chamber muffler)
72 Muffler (Valve on the valve side)
A1 Pressure receiving area A2 in the vertical direction of sub valve body Opening area A2 of the large flow valve port Pressure area As in the vertical direction of the back pressure chamber As small opening area of the small flow port φD1 Pressure receiving diameter of the sub valve body D2 large flow valve Port diameter φD3 Back pressure chamber diameter φDs Small flow port diameter

Claims (12)

A valve body provided with a valve chamber and a large flow rate valve port, a first valve body disposed so as to be movable up and down in the valve chamber, a lift drive unit for moving the first valve body up and down, and a lift amount And the second valve body is slidably inserted over the first valve body so as to surround the outer periphery of the lower end portion of the first valve body in order to change the flow rate of the fluid flowing through the large flow rate valve port according to the And a second valve body driven in conjunction with the lifting and lowering operation of the valve body,
An upper communication passage provided in the first valve body, a communication space defined around the lower end of the first valve body by the second valve body, and a lower link provided in the second valve body A small flow passage communicating the valve chamber with the large flow valve port through the passage is formed, and the first valve body communicates with the upper communication passage in the small flow passage according to the lift amount. It is designed to change the flow rate of fluid flowing through the small flow rate valve port provided between the space and
When the lift amount of the first valve body by the elevation drive unit is equal to or less than a predetermined amount, the large flow rate valve port is closed by the second valve body, and the small flow rate valve port of the first valve body is closed. The small flow rate control state in which the flow rate is controlled according to the lift amount is taken, and when the lift amount of the first valve body by the elevation drive exceeds the predetermined amount, the first valve body is lifted. The second valve body is configured to be in a large flow control state in which the second valve body is opened to open the large flow rate valve port.
The opening area of the large flow rate valve port and the elevation direction of the second valve body so that the force in the valve closing direction acting on the second valve body in the small flow rate control state is greater than the force in the valve opening direction. A flow control valve characterized in that a pressure receiving area is set.   The flow control valve according to claim 1, wherein the opening area of the large flow rate valve port and the pressure receiving area in the vertical direction of the second valve body are set identical.   The opening area of the large flow rate valve port, the pressure receiving area in the vertical direction of the back pressure chamber defined on the back side of the first valve body, and the pressure receiving area in the vertical direction of the second valve body are set identical. 3. The flow control valve according to claim 2, further comprising a pressure equalizing passage communicating the high flow rate valve port with the back pressure chamber.   The flow control valve according to claim 3, wherein the pressure equalizing passage is configured to include a part or a whole of the outer side of the valve chamber in the valve body.   The pressure equalizing passage is configured to include a gap formed between a base member defining the valve chamber and an outer cylinder disposed outside the base member. The flow control valve according to Item 4.   A silencing member for dividing air bubbles in the fluid flowing through the small flow passage is disposed in at least one of the small flow passage from the small flow passage in the small flow passage and the valve chamber side and the large flow valve side. The flow control valve according to any one of claims 1 to 5, characterized in that:   The flow control valve according to claim 6, wherein the muffling member is disposed in the upper communication passage and the lower communication passage in the small flow passage. The second valve body is biased in the valve closing direction of the large flow rate valve port by a biasing member interposed between the second valve body and the first valve body, and the first valve body When the lift amount of the valve element exceeds a predetermined amount, any one of claims 1 to 7, characterized in that it is adapted to be raised pull the flanged engaging part provided in the first valve body The flow control valve according to one item.   The second valve body is connected to a cylindrical interlocking member slidably inserted at the lower end portion of the first valve body and the lower end opening of the interlocking member, and opens and closes the large flow rate valve port The flow control valve according to any one of claims 1 to 8, characterized by comprising a valve body member.   The sealing member which seals between the said communication space and the said valve chamber is interposed between the lower end part of the said 1st valve body, and the said interlocking member, It is characterized by the above-mentioned. Flow control valve.   Air bubbles in the fluid flowing through the small flow rate passage are formed in the vertical hole in the upper communication passage of the first valve body and / or the vertical hole in the lower communication passage provided in the valve body member of the second valve body 10. The flow control valve according to claim 9, further comprising a noise reduction member to be subdivided.   The flow control valve according to claim 11, wherein the small flow rate valve port is provided in a vertical hole in the upper communication passage of the first valve body.

Images