JP6037958B2 - Flow control valve and heat pump device - Google Patents

Description

  The present invention relates to a flow control valve and a heat pump device.

  As a conventional flow control valve, the valve body moves directly with respect to the valve hole of the valve body, changes the cross-sectional area of the annular gap between the inner peripheral surface of the valve hole and the valve body, and passes through the valve hole The one that controls the flow rate of the fluid is known. Moreover, this type of flow control valve is incorporated in, for example, a heat pump device (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2006-207852 (paragraphs [0023] to [0044], FIG. 1)

  By the way, the flow rate control valve incorporated in the heat pump device is a refrigerant with a minute flow rate so that the valve hole is not fully closed even when the valve body is set to the minimum valve opening degree in order to prevent the burn-in of the compressor. May be adjusted to flow.

  However, in the above-described conventional flow control valve, the valve body is loosely fitted inside the valve hole when the minimum valve opening is set. There is a possibility that the valve body will fluctuate inside the valve hole due to irregular flow or vibration from the outside, and contact with each other. At this time, since the contact is made at a portion where the cross-sectional area of the annular gap is the minimum, that is, a portion that determines the flow rate, there is a problem that the relationship between the valve opening degree and the flow rate changes due to wear of the contact portion.

  In recent years, the field of use of flow control valves has been diversified, and accordingly, development of a flow control valve having unprecedented flow characteristics has been desired.

  The first object of the present invention made in view of the above circumstances is to provide a flow rate control valve capable of suppressing a change in the relationship between the valve opening degree and the flow rate, and a heat pump device including the same. The second object of the present invention is to provide a flow rate control valve having a flow rate characteristic that has not existed in the past and a heat pump device having the flow rate control valve.

The flow rate control valve (10) according to the invention of claim 1 made to achieve the above object directly moves the valve body (25) with respect to the valve hole (51) of the valve body (32), A flow control valve (10) for controlling the flow rate of the fluid passing through the valve hole (51) by changing the cross-sectional area of the annular gap (C) between the inner peripheral surface of (51) and the valve body (25). In the valve body (25) gradually increased in diameter toward the base end side, and provided in the valve hole (51), the diameter is increased toward the base end side at a diameter expansion rate smaller than the valve body (25), A valve body (25) in a state of entering the valve hole (51), and a hole intermediate portion (51B) facing the intermediate portion in the axial direction . The valve body (25) is larger than the hole intermediate portion (51B). When moving away from the fully closed position in contact with the radial end (51B1), the portion of the hole intermediate portion (51B) that is closest to the valve body (25) is the hole intermediate portion ( 1B), the portion having the smallest cross-sectional area of the annular gap (C) while being the large-diameter end (51B1) reaches the first position where the small-diameter end (51B2) of the hole intermediate portion (51B) is reached. The first position is one end of the movable range of the valve body (25), and the valve body (25) is linearly moved only on the side away from the fully closed position from the first position .

The heat pump apparatus according to the invention of claim 2 (100) is characterized by chromatic Then around the flow control valve (10) according to claim 1.

According to the configuration of the present invention, the valve body (25) of the flow control valve (10) is closest to the large-diameter side end (51B1) of the hole intermediate portion (51B) at the first position at one end of the movable range. At this time, the cross-sectional area of the annular gap (C) is minimized between the small diameter side end portion (51B2) of the hole intermediate portion (51B) and the valve body (25). That is, of the inner peripheral surface of the valve hole (51), a part position closest to the valve body (25), and the parts position in which the cross-sectional area of the annular gap (C) is minimized, the valve hole (51 ) Is shifted in the axial direction . Thereby , even if the valve body (25) fluctuates inside the valve hole (51) and they come into contact with each other, it is possible to avoid a change in the minimum cross-sectional area in the annular gap (C). That is, it is possible to suppress a change in the relationship between the valve opening and the flow rate.

Here, the valve body (25), the hole intermediate part (51B), the hole base end part (51A), and the hole front end part (51C) according to the present invention are expanded in diameter while being rounded toward the base end side. Alternatively, the diameter may be increased toward the base end side with a certain taper angle.

1 is a side sectional view of a flow control valve according to a first embodiment of the present invention. An enlarged side cross-sectional view of a part of the flow control valve Side sectional view of the tip of the flow control valve when the valve body is at the reference valve opening Enlarged view of valve body and valve hole (A) Sectional view when the valve body part and the valve seat are cut along the cut surface including the first knot, (B) Cross section when the valve body part and the valve seat are cut along the cut surface including the second knot Figure Graph showing the relationship between valve opening and flow rate of flow control valve Conceptual diagram of heat pump device Side sectional view of the tip of the flow control valve according to the modification.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The flow control valve 10 of the present embodiment is a so-called “electric expansion valve”, and is shown entirely in FIG. The flow control valve 10 may be used in any posture with respect to the direction of gravity, but for convenience of explanation, the vertical direction in FIG. 1 is hereinafter referred to as the vertical direction of the flow control valve 10 and its components. To do.

  The flow control valve 10 is provided with the stator side field portion 11 fixed to the outside of the sleeve 30, while the rotor side field portion 12 is rotatably accommodated inside the sleeve 30. And the stepping motor 20 is comprised by making the stator side field part 11 and the rotor side field part 12 into a main part.

  The stator side field portion 11 has an annular shape and includes a plurality of electromagnetic coils 11A arranged in the circumferential direction. Further, a connector portion 11 </ b> B protrudes from the side surface of the stator side field portion 11.

  The rotor-side field magnet portion 12 is a permanent magnet having a cylindrical shape with an upper end and has, for example, magnetic poles at positions where the circumferential direction is equally divided. A rotor shaft 13 passes through the center of the upper end wall 12A of the rotor side field portion 12. The rotor shaft 13 includes a drive shaft 14 and a needle-shaped valve body component 22. The drive shaft 14 includes a flange portion 14A at an intermediate position in the axial direction, and the flange portion 14A is fixed to the center portion of the upper end wall 12A. A spiral guide 16 is fixed to a portion of the drive shaft 14 above the flange portion 14A. The spiral guide 16 has a structure in which a wire rod is spirally wound around the upper end portion of the drive shaft 14 and the upper end portion of the wire rod is passed through the upper end portion of the drive shaft 14 from the side.

  A stopper ring 17 is engaged with the spiral guide 16. The stopper ring 17 has a ring shape that fits in a part of the gap between the wire rods adjacent to each other in the axial direction in the spiral guide 16 and is provided with a stopper arm 17A protruding to the side. A stopper shaft 19 is suspended from the lid 18 that closes the upper end opening of the sleeve 30 in parallel with the drive shaft 14. When the rotor side field magnet portion 12 rotates with the stopper arm 17A in contact with the stopper shaft 19, the stopper ring 17 rotates relative to the spiral guide 16 and moves up and down. When it moves to the part or the lower end, it becomes impossible to rotate. Thereby, the rotation amount of the rotor side field part 12 is regulated.

  A cylindrical sliding shaft portion 14B and a male screw portion 14C are arranged vertically below the driving shaft 14 below the flange portion 14A. A connecting hole 14 </ b> D is drilled in the center of the drive shaft 14, and the connecting hole 14 </ b> D opens to the lower end surface of the drive shaft 14. A compression coil spring 21 is accommodated in the connecting hole 14D, and an upper end portion of the valve body component 22 is accommodated below the compression coil spring 21.

  The sleeve 30 includes an outer cylinder part 31 and an inner cylinder part 32, and the outer cylinder part 31 and the inner cylinder part 32 are arranged coaxially. The outer cylinder portion 31 has a cylindrical shape larger in diameter than the inner cylinder portion 32, and the upper surface opening is sealed by the lid body 18. The lid 18 is made of the same material (for example, stainless steel) as the outer cylinder portion 31 and is welded to the outer cylinder portion 31. Further, an annular flange 31 </ b> A projects from the lower opening edge of the outer cylinder portion 31 toward the axis of the outer cylinder portion 31. The outer cylindrical portion 31 is welded to the upper surface of the base plate 41 with the flange 31 </ b> A being directed to the upper surface of the annular base plate 41. The base plate 41 is fixed to the stator side field 11.

  An annular step portion 32D is formed in an axially intermediate portion of the outer peripheral surface of the inner cylinder portion 32, and a large diameter portion above the annular step portion 32D is accommodated inside the outer cylinder portion 31, A small-diameter portion below the step portion 32D extends downward through the flange 31A and the base plate 41 of the outer cylinder portion 31. And the outer peripheral surface of the inner cylinder part 32 is welded to the lower surface of the base plate 41 in the state which latched the annular level | step-difference part 32D to the inner edge part of the flange 31A.

  As shown in FIG. 2, a valve seat 50 having a valve hole 51 is provided inside the lower end portion of the inner cylinder portion 32. The valve hole 51 is provided coaxially with the valve body component 22 and opens to the lower end surface of the inner cylinder portion 32. The valve seat 50 and the valve hole 51 will be described in detail later together with the valve body part 22. The inner cylinder portion 32 corresponds to the “valve body” of the present invention.

  A side opening 32 </ b> B that is open to the side is formed near the lower end of the inner cylinder portion 32. The side opening 32B is provided at a position higher than the valve seat 50, and the flow path pipe P1 is inserted into the side opening 32B and welded.

  From the lower end surface 32A of the inner cylinder part 32, the flow path pipe P2 extends downward. An annular groove 32C concentric with the valve hole 51 is formed on the lower end surface of the inner cylindrical portion 32, and the upper end portion of the flow path pipe P2 is inserted into the annular groove 32C and welded. .

  The bearing sleeve 43 and the nut 44 shown in FIG. 2 are inserted and assembled inside the inner cylinder portion 32. The bearing sleeve 43 is press-fitted above the side opening 32 </ b> B in the inner cylinder part 32, and the nut 44 is press-fitted into the upper end part of the inner cylinder part 32. An upper end portion of the nut 44 is a bearing portion 44B, and a lower portion from the bearing portion 44B is a female screw portion 44A.

  Then, the male screw portion 14C of the rotor shaft 13 is screwed into the female screw portion 44A of the nut 44, and the sliding shaft portion 14B of the drive shaft 14 is rotatably supported by the bearing portion 44B of the nut 44 so as to be rotatable and linearly movable. Further, an intermediate portion (main shaft portion 22B described later) of the valve body component 22 constituting the rotor shaft 13 is pivotally supported by the bearing sleeve 43 so as to be rotatable and linearly movable. Note that a gap is maintained between the outer peripheral surface of the rotor-side field portion 12 and the inner peripheral surface of the outer cylindrical portion 31 of the sleeve 30.

  The flow control valve 10 is incorporated in the heat pump apparatus 100 as shown in FIG. This heat pump device 100 is an air conditioner having a compressor 101, an indoor heat exchanger 102, and an outdoor heat exchanger 103, and the connector portion 11B of the flow control valve 10 is connected to a control circuit (not shown) of the heat pump device 100. Is done. Then, the electromagnetic coil 11A is excited by receiving electric power from the control circuit, the rotor shaft 13 is rotationally driven together with the rotor-side field portion 12, the valve body component 22 is linearly moved, the valve opening is changed, The flow rate of the refrigerant flowing between the road pipe P1 and the flow path pipe P2 is changed, for example, as shown in the graph of FIG. Specifically, when the rotor-side field portion 12 is driven to rotate and the stopper ring 17 moves to the upper end portion of the spiral guide 16 and becomes unrotatable, the tip end portion of the valve body component 22 becomes the valve hole. 51 (the valve opening degree is the minimum) (see FIG. 1). Further, when the stopper ring 17 moves to the lower end portion of the spiral guide 16 and becomes unrotatable, the valve body component 22 is at the most retracted position (the valve opening is maximum) from the valve hole 51. Here, the horizontal axis of the graph of FIG. 6 represents the linear motion position (valve opening degree) of the valve body component 22 by the number of input pulses of the stepping motor 20. In this graph, when the number of input pulses is “0”, the distal end portion of the valve body component 22 is in the position most plunged into the valve hole 51 (the valve opening is minimum), and the valve increases as the number of input pulses increases. The front end of the body part 22 is retracted from the valve hole 51.

  Hereinafter, the valve body component 22 will be described in detail. As shown in FIG. 2, the valve body component 22 has a shaft shape with a circular cross section, and a flange-shaped locking wall 22 </ b> A is formed at an upper end portion (base end portion) thereof. Then, the retaining ring 28 is press-fitted into the lower end portion of the coupling hole 14D with the flange-shaped locking wall 22A being inserted into the coupling hole 14D, and the base end portion of the valve body part 22 is prevented from coming off in the coupling hole 14D. . The lower end portion of the compression coil spring 21 is pressed against the upper surface of the flange-shaped locking wall 22A, and the upper end portion of the compression coil spring 21 is pressed against the inner wall of the connecting hole 14D.

  The valve body component 22 includes a relatively thick shaft portion 23 and a relatively thin valve body 25, and an intermediate curved portion 24 is provided between the shaft portion 23 and the valve body 25. The shaft portion 23 has a cylindrical shape having a constant outer diameter larger than the inner diameter of the valve hole 51. The valve body 25 has a tapered shape with a diameter gradually reduced from the upper end portion (base end portion) on the shaft portion 23 side toward the lower end portion (tip end portion). The intermediate bending portion 24 has a rounded shape that gradually increases in diameter from the valve body 25 toward the shaft portion 23 and expands outward.

  The valve body 25 is composed of a valve body main body portion 25A and a valve body front end portion 25B having different taper angles. The valve body main body 25A has a truncated cone shape whose diameter is increased at a constant taper angle β toward the base end (large diameter side end). On the other hand, the valve body distal end portion 25B has a conical shape whose diameter is reduced downward from the distal end portion (small diameter side end portion) of the valve body main body portion 25A with a constant taper angle larger than that of the valve body main body portion 25A. . In addition, the taper angle of the valve body main body 25A is, for example, 5 ° to 15 ° (preferably 10 °).

  The valve seat 50 is integrally formed inside the lower end portion of the inner cylinder portion 32, and the valve hole 51 passes through the center of the valve seat 50. As shown in FIG. 3, the valve hole 51 has an R between the hole tip 51 </ b> C having the smallest inner diameter and the uniform diameter among the valve holes 51, and the lower end surface 32 </ b> A of the inner cylinder part 32. A chamfered hole tip curved portion 51D, a hole intermediate portion 51B that is continuous with the base end portion of the hole tip portion 51C, and that increases in diameter in a tapered shape as it moves away from the hole tip portion 51C toward the base end side, and a hole intermediate portion 51B It has a hole base end portion 51A that is connected to the end portion on the large diameter side and has a diameter increased toward the base end side with a larger taper angle than the hole intermediate portion 51B.

  The taper angle α of the hole intermediate portion 51B is smaller than the taper angle β (for example, 5 ° to 15 °) of the valve body main body portion 25A. For example, it is about ½ of the taper angle β of the valve body body 25A. The “taper angle” of the hole intermediate part 51B, the valve body main part 25A, etc. in this document is an angle between two bus bars in a cross section when they are cut by a cut surface including the central axis. . In the following description, the large-diameter side end portion of the hole intermediate portion 51B (boundary portion with the hole base end portion 51A) is referred to as “first knot portion 51B1”, and the small-diameter side end portion (hole) of the hole intermediate portion 51B. The boundary portion with the tip 51C is referred to as “second node 51B2.”

  The relationship between the valve opening and the flow rate (flow rate characteristics) of the flow control valve 10 having the above-described configuration is as shown in the graph of FIG. That is, while the valve body main part 25A of the valve body component 22 is displaced inside the hole intermediate part 51B, the hole tip part 51C or the hole tip curved part 51D (between the number of input pulses is “0” to “350”). ), While the flow rate changes relatively slowly, the flow rate increases rapidly when the valve body 25A is completely removed from the hole intermediate portion 51B (the number of input pulses exceeds “350”).

  By the way, the flow rate control valve 10 of the present embodiment prevents the valve hole 51 from being fully closed even when the valve body 25 is set to the minimum valve opening degree (when the number of input pulses is “0” in FIG. 6). It is configured so that a very small amount of refrigerant can flow. Hereinafter, the minimum valve opening in the present embodiment is referred to as “reference valve opening”, and the flow rate of refrigerant that can flow at the reference valve opening is referred to as “zero pulse flow rate”.

Specifically, as shown in FIG. 3, when the valve opening is set to the reference valve opening, the valve body 25 penetrates the valve hole 51 and protrudes to the lower end surface 32 </ b> A side of the inner cylinder portion 32. Become. At this time, in the valve hole 51, the hole intermediate part 51B and the hole tip part 51C are opposed to the intermediate part in the axial direction of the valve body main body part 25A, and between the inner peripheral surface of the valve hole 51 and the valve body 25. Is formed with an annular gap C communicating between the flow path pipes P1, P2. The annular gap C is adjusted so as to have a predetermined zero pulse flow rate, and thus it is possible to prevent the compressor 101 (see FIG. 7) provided in the heat pump device 100 from being seized. In the present embodiment, the zero pulse flow rate when the refrigerant flows from the flow path pipe P1 toward the flow path pipe P2 is, for example, 0.3 [m ³ / h], and the flow from the flow path pipe P2 The zero pulse flow rate when the refrigerant flows toward the road pipe P1 is adjusted at the time of assembling the valve body component 22 so as to be, for example, 0.4 [m ³ / h].

  As shown in FIG. 3, when the valve opening is set to the reference valve opening, the cross-sectional area of the annular gap C is changed from the large-diameter side end of the hole tip bending portion 51D to the upper end (base end) of the hole tip 51C. Part), it gradually becomes smaller. That is, the flow path of the refrigerant is gradually throttled from the lower end surface 32A of the inner cylinder part 32 toward the hole intermediate part 51B. With such a configuration, when the refrigerant flows from the flow path pipe P2 toward the flow path pipe P1, the flow of the refrigerant flowing from the lower end surface 32A of the inner cylindrical portion 32 into the annular gap C is stabilized. Can be made.

  As shown in FIG. 3, when the valve opening is set to the reference valve opening, the hole base end portion 51 </ b> A faces the upper end portion of the valve body main body portion 25 </ b> A and the intermediate bending portion 24. Thereby, between the hole base end portion 51A and the valve body component 22, an annular flow path having a gradually increasing cross-sectional area as the distance from the first node portion 51B1 of the hole intermediate portion 51B is formed. Thereby, when the refrigerant flows from the flow path pipe P1 toward the flow path pipe P2, the flow of the refrigerant flowing from the hole base end portion 51A side into the annular gap C can be stabilized. With these configurations, cavitation and refrigerant passing sound can be suppressed.

  Incidentally, in the flow control valve 10 of the present embodiment, as described above, the taper angle α of the hole intermediate part 51B of the valve hole 51 is smaller than the taper angle β of the valve body main part 25A. As shown, when the valve opening is set to the reference valve opening, the interval between the inner peripheral surface of the hole intermediate portion 51B and the outer peripheral surface of the valve body 25 (the width of the annular gap C) is the hole intermediate portion 51B. Gradually decreases from the second node 51B2 toward the first node 51B1 (see FIG. 4). And among the valve hole 51 whole, 1st node part 51B1 of the hole intermediate part 51B comes closest to the outer peripheral surface of the valve body 25 (valve body main-body part 25A).

  On the other hand, when the valve opening is set to the reference valve opening, the inner diameter of the second node 51B2 of the hole intermediate part 51B (the outer diameter of the annular gap C) is the inner diameter of the first node 51B1 of the hole intermediate part 51B ( It is smaller than the outer diameter of the annular gap C (see FIGS. 5A and 5B). In this embodiment, the cross-sectional area of the annular gap C (see FIG. 4A) when cut by the cut surface including the first node 51B1 of the hole intermediate part 51B is the second node of the hole intermediate part 51B. It is comprised so that it may become larger than the cross-sectional area (refer FIG. 4 (B)) of the cyclic | annular clearance gap C when cut | disconnecting by the cut surface containing part 51B2. That is, when the valve opening is set to the reference valve opening, the cross-sectional area of the annular gap C is minimized between the second node 51B2 of the hole intermediate portion 51B and the valve body main body 25A. The flow rate passing through the flow control valve 10 is determined by the cross-sectional area.

  Now, in the flow control valve 10 of the present embodiment, as shown in FIG. 3, even when the valve opening is set to the reference valve opening, the valve body 25 (the valve body body 25 </ b> A) remains in the valve hole 51. It is loosely fitted inside the hole intermediate part 51B. Therefore, for example, the valve body 25 (valve body body portion 25A) fluctuates inside the valve hole 51 due to variations in parts processing accuracy and assembly accuracy, irregular refrigerant flow, and external vibration. There is a possibility of contact with the inner peripheral surface.

  On the other hand, in the flow control valve 10 of the present embodiment, the valve body 25 (valve body body portion 25A) in the inner peripheral surface of the valve hole 51 in a state where the valve opening is set to the reference valve opening. The closest part (the first node 51B1 of the hole intermediate part 51B) and the part (the second node 51B2 of the hole intermediate part 51B) where the cross-sectional area of the annular gap C is minimized are the axis of the valve hole 51. Are displaced from each other in the direction. Therefore, even if the valve body 25 fluctuates and comes into contact with the inner peripheral surface of the valve hole 51, the contacted portion is the first node 51B1 of the hole intermediate part 51B, and determines the flow rate passing through the flow control valve 10. It is possible to avoid contact between the part, that is, the second node 51B2 of the hole intermediate portion 51B and the valve body 25 (valve body main body portion 25A). Thereby, it can suppress that the relationship between a valve opening degree and flow volume changes.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the above-described embodiment, the valve body main body portion 25A has a diameter that increases toward the base end side at a constant taper angle β, but may increase in diameter while rounding toward the base end side. . In the above-described embodiment, the hole base end portion 51A and the hole intermediate portion 51B are each enlarged in diameter toward the base end portion at a constant taper angle, but the hole intermediate portion 51B is smaller than the valve body 25. The diameter may be rounded and expanded toward the base end side, or the hole base end portion 51A may be rounded toward the base end side at a larger diameter expansion rate than the hole intermediate portion 51B. The diameter may be increased.

  (2) In the above embodiment, the inner diameter of the hole tip 51C is a uniform diameter, but even if the diameter is increased toward the proximal end with a smaller diameter expansion rate or a constant taper angle than the hole middle 51B. Alternatively, the diameter may be reduced toward the base end (for example, the diameter may be reduced with a certain taper angle).

  (3) The valve body component 22 of the above embodiment has a structure in which the shaft portion 23 extends from the large-diameter side end of the valve body 25. For example, as shown in FIG. As a structure in which the shaft portion 23 extends from the small diameter side end portion of the valve body main body portion 25A, a driving source (not shown) such as a stepping motor is provided at the end portion of the valve body component opposite to the valve body main body portion 25A. It is good also as a structure which connected.

  (4) In the said embodiment, although the air conditioning apparatus was illustrated as an example of a "heat pump apparatus", you may apply this invention to another heat pump apparatus (for example, water heater, refrigerator, etc.). Moreover, although the electric expansion valve is illustrated as an example of the “flow control valve”, the present invention may be applied to other flow control valves.

10 Flow control valve 25 Valve body 25A Valve body body 32 Inner cylinder (valve body)
51 Valve hole 51A Hole base end part 51B Hole intermediate part 51B1 First node part 51B2 Second node part 51C Hole tip part 51D Hole tip curved part 100 Heat pump device C Annular gap

Claims (2)

The valve body is linearly moved with respect to the valve hole of the valve body, the cross-sectional area of the annular gap between the inner peripheral surface of the valve hole and the valve body is changed, and the flow rate of the fluid passing through the valve hole is changed. In the flow control valve to control,
The valve body gradually expanding in diameter toward the base end side;
A hole intermediate portion that is provided in the valve hole, expands toward the base end side at a diameter expansion rate smaller than the valve body, and opposes an axial intermediate portion of the valve body in a state of entering the valve hole; When the valve body moves away from the fully closed position where it contacts the large-diameter side end of the hole intermediate portion, the portion of the hole intermediate portion that is closest to the valve body is the hole intermediate portion. The portion where the cross-sectional area of the annular gap is the smallest even though it is the large-diameter side end is configured to reach the first position that becomes the small-diameter side end of the hole intermediate portion,
The flow rate control valve in which the first position constitutes one end of the movable range of the valve body, and the valve body moves directly only on the side away from the fully closed position from the first position. A heat pump apparatus comprising the flow control valve according to claim 1.

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