JP2015113909A - Variable orifice device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable orifice device capable of surely avoiding a situation in which a valve seat corresponding portion and the like of a throttle passage deforms, capable of expanding a usable temperature range and capable of acquiring desired performance even under an environment where temperature drop is violent.SOLUTION: On a peripheral side part of one end side of an orifice case 10, a transverse hole 30 is opened, and a rod-like valve body 20 is fitted and inserted in the orifice case 10. According to a difference in an expansion and contraction amount between the orifice case 10 and the valve body 20 according to temperature change of a refrigerant, a separation distance ΔL between one end 30a of the transverse hole 30 and one end 21a of a contact outer peripheral surface part 21 of the valve body 20 changes; thereby, an effective opening area (area of an arch-shaped opening portion 32) S of the transverse hole 30 changes, and a flow rate of the refrigerant passing in the orifice case 10 is automatically adjusted.

Description

  The present invention relates to a variable orifice device that can automatically adjust a flow rate (valve opening) in accordance with the temperature of a fluid flowing in a flow path.

  For example, in a refrigerant circuit such as a room air conditioner or a car air conditioner, changing the flow rate of the refrigerant flowing through the flow path according to the temperature of the fluid, for example, increasing the flow rate when the refrigerant temperature is high, It may be desired to reduce the flow rate as the refrigerant temperature decreases.

  As described above, in order to change the flow rate of the fluid flowing in the flow path according to the temperature of the fluid, it has been conventionally considered to provide a variable orifice apparatus in the flow path. However, there is a problem that assembly property, incorporation into a flow path (conduit), etc. are not so much considered, the structure is complicated, the number of parts is large, and the manufacturing cost is increased.

  Therefore, the inventors of the present invention have previously proposed a variable orifice device as shown in FIG. 6 in order to solve the above problem (see also Patent Document 1). The variable orifice device 9 includes an orifice case 10 and a valve body 20 made of different materials having different linear expansion coefficients. A restricting passage 14 is formed on one end side (large diameter portion 12) of the orifice case 10, and the orifice case 10 The valve body 20 is telescopically inserted into the valve body 20, and the base end portion (male thread portion) of the valve body 20 is screwed and fixed to the other end side (the female thread portion thereof) of the orifice case 10. The flow rate of the fluid flowing through the throttle passage 14 is adjusted by the difference in expansion / contraction amount between the orifice case 10 and the valve body 20 generated accordingly.

  In the variable orifice device 9, the distance ΔL between the opening end (valve seat 15) on the right side of the throttle passage 14 and the seating portion on the valve seat 15 in the conical valve body 25 provided at the tip of the valve body 20. Is an index representing the valve opening, and the larger the separation distance ΔL, the higher the flow rate of the fluid flowing through the throttle passage 14. The separation distance ΔL changes due to a difference in expansion / contraction amount generated according to a change in the temperature of the fluid between the orifice case 10 and the valve body 20 made of different materials having different linear expansion coefficients.

  Here, for example, the valve body 20 is made of metal, the orifice case 10 is made of resin, and the fluid (high-pressure refrigerant) passes through one end side (large diameter portion 12) of the variable orifice device 9 in the conduit 8 constituting the refrigerant circuit. Assuming that the refrigerant flows from the other side to the other end side, the refrigerant passes through the gap formed between the throttle passage 14 and the tip of the valve body 20 from the throttle passage 14 and is further inscribed in the conduit 8. It flows out from the through hole 16 formed in the cylindrical case portion 11 having a rectangular cross-sectional outline to a flow path formed between the outer peripheral four surfaces and the inner peripheral surface of the conduit 8 and flows downstream of the conduit 8.

  Since the refrigerant that has exited the throttle passage 14 expands and falls in temperature, the temperature of the refrigerant flowing through the variable orifice device 9 gradually decreases, and the valve body 20 and the orifice case 10 (the cylindrical case portion 11 of the valve body 20 and the orifice case 10) due to this refrigerant temperature decrease. ) Is shrunk, but the amount of shrinkage is considerably larger in the resin orifice case 10 than in the metal valve body 20 (linear expansion coefficient is 5 to 10 times). The valve opening represented by the separation distance ΔL is reduced, and thereby the flow rate of the refrigerant flowing through the throttle passage 14 is reduced. Thus, in the previously proposed variable orifice device 9, the valve body 20 and the orifice case 10 serve as a temperature sensing part, and the flow rate of the fluid flowing through the flow path is made variable according to the temperature of the fluid. Can do.

  Since the variable orifice device 9 is basically composed of two parts, the orifice case 10 and the valve body 20, the structure can be simplified and the number of parts can be reduced. The body 20 can be easily assembled by screwing or the like, and a flow path (conduit) is mounted by attaching an O-ring 18 to the ring groove 13 formed on one end side (large diameter portion 12) of the orifice case 10. ), It is excellent in assembling property, assembling property in a flow path (conduit), etc., and it is possible to reduce manufacturing cost, assembling and assembling cost.

JP 2002-181227 A

  However, the conventional variable orifice device 9 may cause the following problems. That is, for example, if the valve body 20 is made of metal and the orifice case 10 is made of resin, the valve body 20 and the orifice case 10 are shrunk due to a decrease in the refrigerant temperature, but the resin is larger than the shrinkage amount of the metal valve body 20. Since the shrinkage amount of the made orifice case 10 is considerably larger, when the refrigerant temperature is greatly lowered, the opening end edge (valve seat) 15 of the throttle passage 14 in the orifice case 10 becomes the conical valve body portion 25 of the valve body 20. 6C, the throttle passage 14 may be closed with the valve body 20 as shown in FIG. 6C. When the temperature of the temperature sensing part composed of the orifice case 10 and the valve body 20 is further lowered due to a further decrease in temperature from this valve-closed state, the valve seat 15 part further becomes a conical valve body part 25 of the valve body 20. The valve seat 15 and the like are deformed by being strongly pressed. Therefore, in the conventional variable orifice device, there is a possibility that desired performance cannot be obtained in an environment where the usable temperature range is narrow and the temperature drop is severe.

  In addition, since the refrigerant does not flow at all when the valve is closed, there is a problem that the oil mixed in the refrigerant does not rotate to the sliding portion of the compressor.

  The present invention has been made in view of the problems as described above, and the object of the present invention is that the flow rate of the fluid flowing through the flow path can be variably adjusted according to the temperature of the fluid, and In addition to being easy to assemble and assembling into a flow path (conduit), the structure can be simplified, the number of parts can be reduced, and the manufacturing cost can be reduced. It is an object of the present invention to provide a variable orifice device that can obtain desired performance without causing problems such as deformation even under severe environment.

  In order to achieve the above object, a variable orifice device according to the present invention basically includes a cylindrical orifice case in which a lateral through hole is opened in a peripheral side portion on one end side, and an effective opening of the lateral through hole. The orifice includes a rod-like valve body that is telescopically inserted into the orifice case in order to change the area and whose base end is fixed to the other end of the orifice case, and the orifice according to the temperature change of the fluid The effective opening area of the side through hole is changed according to the difference in expansion / contraction amount between the case and the valve body, whereby the flow rate of the fluid passing through the orifice case is automatically adjusted.

  In a preferred aspect, the valve body has a contact outer peripheral surface portion that abuts an inner peripheral surface of the orifice case around the transverse hole, and an amount of expansion / contraction between the orifice case and the valve body in accordance with a fluid temperature change. The separation distance between the one end of the through hole and the one end of the contact outer peripheral surface portion is changed according to the difference, and thereby the effective opening area of the through hole is changed. Yes.

  In another preferred aspect, a large diameter portion is formed on one end side of the orifice case, and the through hole is formed in the vicinity of the large diameter portion.

  In another preferred embodiment, the orifice case includes a metal or resin front end side case portion including the large diameter portion and the lateral through hole, and a resin in which a base end portion of the valve body is fixed to the other end portion. And a base end side case portion made of metal, and the valve body is made of a metal rod-like body.

  In another preferred aspect, the valve body has a round bar shape, one end surface of the valve body has a vertical cut surface, and the entire outer peripheral surface on one end side of the valve body forms the contact outer peripheral surface portion. It is characterized by.

  In another preferred embodiment, the valve body has a round bar shape, and a conical surface portion and the abutting outer peripheral surface portion are sequentially arranged on one end side of the valve body.

  In another preferred embodiment, the orifice case has a stepped cylindrical shape.

  In another preferred embodiment, the through hole has a circular shape, an elliptical shape, or a polygonal shape.

  In the variable orifice device according to the present invention, a through hole is opened in a peripheral side portion on one end side of an orifice case, and a rod-shaped valve body is fitted into the orifice case, so that the orifice case and valve according to fluid temperature change The separation distance between one end of the through hole and one end of the contact outer peripheral surface of the valve body changes according to the difference in expansion and contraction with the body, thereby changing the effective opening area of the through hole and changing the orifice The flow rate of the refrigerant passing through the case is automatically adjusted. That is, since there is no valve seat on which the valve body (valve body portion) is seated as in the prior art, even if the difference in expansion / contraction amount between the orifice case and the valve body due to the temperature change of the fluid increases, Even if the left end of the body is displaced to the left relative to the through hole and the through hole is closed by the valve body, the valve body is not relatively pressed against the orifice case portion.

  Therefore, according to the present invention, it is possible to reliably prevent a situation in which the valve seat portion or the like of the orifice case is deformed, expand the usable temperature range, and obtain desired performance even in an environment where the temperature drop is severe. Can do. In addition, the conical valve body, the throttle passage, the valve seat, and the like that are provided in the conventional structure are no longer necessary, so that the processing cost of the parts can be reduced.

  In addition, since the valve body is inserted into the orifice case so as to be extendable and retractable, even if the through hole is closed by the valve body (even if the effective opening area is 0), the inner peripheral surface of the valve body and the orifice case A gap is formed between the peripheral surface and the refrigerant flows through the gap, so that the oil mixed in the refrigerant is supplied to the sliding portion of the compressor and the like. Can be prevented.

The state which incorporated the Example of the variable orifice apparatus which concerns on this invention in the conduit | pipe is shown, (A) is the state in which a through-hole and a valve body exist in a normal flow volume adjustment position, (B) is the temperature of fluid. The partial notch sectional drawing which shows the state where the difference of the expansion-contraction amount of the orifice case and valve body accompanying a change became large respectively, respectively. (A) is an enlarged view of part A of FIG. 1 (A), (B) is an enlarged view of the arrow U in FIG. 2 (A), and (C) is an enlarged cross-sectional view around the through hole in FIG. 2 (A). . FIG. 4A is an enlarged view of a portion C in FIG. 1A, and FIG. 3B is a cross-sectional view taken along line VV in FIG. The enlarged view of the B section of FIG. (A) is a figure equivalent to the U arrow enlarged view of FIG. 2 (A) which shows one modification of an Example, (B) is an expanded sectional view of a through-hole periphery which shows the other modification of an Example. An example of a conventional variable orifice device is shown, (A) is an enlarged cutaway cross-sectional view of the main part, (B) is a cross-sectional view taken along the line BB of FIG. The principal part expansion notched sectional view which shows the state pressed against the valve body.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 5 are diagrams for explaining embodiments (examples and modifications) of a variable orifice device according to the present invention. In each figure, the conventional variable orifice shown in FIG. The same constituent parts, the same functional parts, or the corresponding parts as the respective parts of the apparatus are denoted by common reference numerals or related reference numerals. In order to facilitate understanding of the present invention and for convenience in drawing, in each drawing, the amount of expansion / contraction of each part accompanying the temperature change, the separation distance, etc. are exaggerated.

  FIG. 1 is a partially cutaway cross-sectional view showing a state where a variable orifice device according to an embodiment of the present invention is incorporated in a conduit, and FIGS. 2 and 3 are enlarged views of main portions of the embodiment.

  The variable orifice device 1 shown in the figure is opposite in the refrigerant flow direction to the conventional variable orifice device shown in FIG. 6 (FIGS. 1 and 2 of Patent Document 1). ) To the left side (OUT side) and is incorporated into a conduit 8 constituting a refrigerant circuit, and includes an orifice case 10 and a valve body 20 made of different materials having different linear expansion coefficients. Here, the main part (base end side case part 11) of the orifice case 10 is made of resin (for example, polyacetal), and the valve body 20 is made of metal (for example, SUS303).

The conduit 8, the orifice case 10, and the valve body 20 are disposed on a common center line O.
Specifically, the orifice case 10 has a stepped and substantially cylindrical shape, and is divided into a metal tip side case portion 12 and a relatively long base end case portion 11 made of resin. The metal front end side case portion 12 includes a large diameter portion 12A, a perforated cylindrical portion 12B, and a connecting male screw portion 12C sequentially from one end side (the left end side in FIGS. 1A and 2A). And four circular holes (see FIG. 2 (A)), for example, at intervals of 90 ° in the circumferential direction in the vicinity of the large-diameter portion 12A on the peripheral side portion of the perforated cylindrical portion 12B. 30 is opened. On the other hand, the base end side case portion 11 includes a connecting female screw portion 11C meshing with the connecting male screw portion 12C of the distal end side case portion 12, a cylindrical portion 11B extending along the conduit 8, and a valve body fixing female screw portion 11A. Have

  The valve body 20 has a round bar shape, and its left end surface has a vertical cut surface perpendicular to the center line O in order to change the effective opening area of the lateral through hole 30, and its left end side is the front end side case portion 12. The entire outer peripheral surface on the left end side is a contact outer peripheral surface portion 21 that is in contact with the inner peripheral surface 10 a around the through hole 30 in the front end side case portion 12. Note that the inner diameter of the inner peripheral surface 10a of the distal end side case portion 12 is smaller than the inner diameter of the inner peripheral surface 10b of the cylindrical portion 11B of the proximal end side case portion 11, and the proximal end portion and the proximal end side of the valve body 20 A gap is formed between the inner peripheral surface 10b of the cylindrical portion 11B of the case portion 11.

  Further, a fixing male thread portion 24 that is screwed into the valve body fixing female thread portion 11 </ b> A of the base end side case portion 11 is formed on the outer periphery of the base end portion (right end portion) 23 of the valve body 20. As shown in FIG. 3, a lock nut 19 is screwed into the outer periphery of the right end portion of the fixing male screw portion 24 and pressed against the right end surface of the orifice case 10. A negative groove 26 is formed at the right end of the fixing male screw portion 24 to be used for adjusting the position of the valve body 20 with respect to the orifice case 10 and preventing rotation when the lock nut 19 is screwed.

  In the variable orifice device 1 of the present embodiment having such a configuration, before assembling it, for example, before the distal end side case portion 12 and the proximal end side case portion 11 of the orifice case 10 are screwed together, The male screw portion 24 for fixing the valve body 20 is screwed into the female screw portion 11A for fixing the valve body of the end side case portion 11 from the left side, and is screwed in until the right end portion projects rightward from the right end of the base end side case portion 11. After that, while inserting the left end portion of the valve body 20 into the distal end side case portion 12, the coupling external thread portion 12C of the distal end side case portion 12 and the internal thread portion 11C for coupling of the proximal end side case portion 11 are screwed. Then, the position of the valve body 20 with respect to the orifice case 10 is adjusted and the lock nut 19 is screwed.

  When incorporating the variable orifice device 1 into the metal conduit 8 forming the flow path, the conduit 8 is subjected to spinning to form the annular groove 8a, and the annular groove 8a is formed in the large diameter portion 12A. Fit into the annular ring groove 13. Thereby, the space between the outer peripheral surface of the large diameter portion 12A and the inner peripheral surface of the conduit 8 is sealed by the annular groove portion 8a, and the incorporation of the variable orifice device 1 into the conduit 8 is completed.

  In the variable orifice device 1 configured as described above, the left end 30a of the through-hole 30 corresponds to the difference in expansion / contraction between the orifice case 10 (the base end side case portion 11) and the valve body 20 accompanying the temperature change of the refrigerant. A separation distance ΔL from the left end 21a of the contact outer peripheral surface portion 21 changes. Accordingly, the effective opening area S of the through hole 30, that is, the arcuate portion of the through hole 30 and the contact outer peripheral surface portion of the valve body 20 as shown by the broken line hatching in FIG. The area S of the arcuate opening (gap) portion 32 formed by the left end 21a (straight line) 21 changes, whereby the flow rate of the refrigerant passing through the orifice case 10 is automatically adjusted.

  In this case, the larger the separation distance ΔL and the effective opening area S, the greater the flow rate of the refrigerant passing through the orifice case 10. The separation distance ΔL and the effective opening area S change due to the difference in expansion / contraction amount accompanying the temperature change of the refrigerant between the resin orifice case 10 and the metal valve body 20.

Here, the linear expansion coefficient at 20 ° C. of the resin (POM) orifice case 10 (the base end side case portion 11) is, for example, 102 × 10 ⁻⁶ / ° C., and the valve body 20 made of metal (SUS303). The linear expansion coefficient is, for example, 14.7 × 10 ⁻⁶ / ° C., and the high-pressure refrigerant passes through the conduit 8 constituting the refrigerant circuit from the right end side (the other end side, the IN side) of the variable orifice device 1 to the left end side ( It flows toward one end side and OUT side).

  For this reason, as shown by an arrow in FIG. 2 (A), the refrigerant passes through a substantially annular flow path formed between the conduit 8 and the orifice case 10 (the base end side case portion 11). As shown in FIG. 2 (B), the broken line hatched in FIG. 2 (B) is formed through the through hole 30 formed in the large diameter portion 12A of the distal end side case portion 12 and formed by the through hole 30 and the left end 21a of the valve body 20. It passes through the arc-shaped opening portion 32, flows out of the orifice case 10 through the tip side case portion 12, and flows to the downstream side of the conduit 8.

  At that time, the valve body 20 and the orifice case 10 (the base end side case part 11) are changed depending on the temperature of the refrigerant flowing through the flow path formed between the conduit 8 and the orifice case 10 (the base end side case part 11). However, the expansion / contraction amount of the base case portion 11 of the resin orifice case 10 is considerably larger than that of the metal valve body 20 (linear expansion coefficient is 5 to 10 times). The valve opening represented by the separation distance ΔL and the effective opening area S of the through hole 30 is changed by the difference in expansion and contraction, whereby the flow rate of the refrigerant flowing through the orifice case 10 is increased or decreased. As described above, in the variable orifice device 1 of the embodiment, the valve body 20 and the orifice case 10 operate as the tube temperature portion, so that the flow rate of the fluid flowing through the flow path is variable according to the temperature of the fluid. Can do.

  In addition, since the variable orifice device 1 of this embodiment is basically composed of two parts, the orifice case 10 and the valve body 20, the structure can be simplified and the number of parts can be reduced. 10 can be easily assembled by screwing the valve body 20 to the pipe 10, and the variable orifice device 1 can be incorporated into the flow path by spinning the conduit 8; ), And can be reduced in manufacturing cost, assembly and assembling cost.

  In addition to the above, in the variable orifice device 1 of the present embodiment, the through hole 30 is opened in the peripheral side portion on one end side of the orifice case 10, and the rod-shaped valve body 20 is inserted into the orifice case 10, The separation distance ΔL between the one end 30a of the transverse hole 30 and the one end 21a of the contact outer peripheral surface portion 21 of the valve body 20 changes according to the difference in expansion / contraction between the orifice case 10 and the valve body 20 due to the temperature change of the refrigerant. As a result, the effective opening area S of the through hole 30 (the area S of the arcuate opening portion 32) changes, and the flow rate of the refrigerant passing through the orifice case 10 is automatically adjusted. That is, since there is no valve seat on which the valve body (valve body portion) is seated as in the prior art, even if the difference in expansion / contraction amount between the orifice case 10 and the valve body 20 due to the temperature change of the refrigerant increases, As shown in FIG. 1B and FIG. 4, the left end of the valve body 20 is relatively displaced to the left of the through hole 30 so that the through hole 30 is closed by the valve body 20. However, the orifice case 10 portion is not relatively pressed against the valve body 20.

  Therefore, in this embodiment, it is possible to reliably avoid a situation where the valve seat portion or the like of the orifice case is deformed, to expand the usable temperature range, and to obtain desired performance even in an environment where the temperature drop is severe. it can. Further, since the conical valve body, the throttle passage, the valve seat, and the like that are provided in the conventional structure are not required, there is an advantage that it is possible to reduce the parts processing cost and the like.

  In addition, since the valve body 20 is inserted into the orifice case 10 so as to be extendable and contractible, even if the lateral through hole 30 is closed by the valve body 20 (even if the effective opening area is 0), A slight gap is formed between the outer peripheral surface and the inner peripheral surface 10a of the orifice case 10 (front end side case portion 12), and the refrigerant flows through this gap, so that the oil mixed in the refrigerant is compressed by the compressor. As a result, the seizure of the compressor can be prevented.

In the variable orifice device 1 of the present embodiment, the through hole 30 is circular as viewed in the radial direction, but the shape of the through hole 30 is not limited to this, and a desired flow rate characteristic is obtained. It can be arbitrarily selected depending on the case. For example, as shown in FIG. 5A, the through holes may be triangular. Also in this case, when the separation distance ΔL between the left end 30a of the through hole 30 ′ and the left end 21a of the contact outer peripheral surface portion 21 changes, the effective opening area S ′ of the through hole 30 ′, that is, as shown in FIG. As indicated by broken line hatching, the area S ′ of the triangular gap portion 32 ′ formed by the left end portion of the through hole 30 ′ and the left end 21 a (straight line) of the contact outer peripheral surface portion 21 of the valve body 20 is As a result, the flow rate of the refrigerant passing through the orifice case 10 is adjusted according to the refrigerant temperature. The lateral through hole may have an elliptical shape, a polygonal shape such as a quadrangular shape or a pentagonal shape in addition to the circular shape or the triangular shape described above.
Further, the number and size of the through holes can be arbitrarily selected according to the desired flow rate characteristics.

  Further, in the variable orifice device 1 of the present embodiment, the valve body 20 has a round bar shape, the left end surface of the valve body 20 is a vertical cut surface perpendicular to the center line O, and the outer peripheral surface on the left end side. The entirety is a contact outer peripheral surface portion 21 that is in contact with the inner peripheral surface 10a of the orifice case 10 (front end side case portion 12). However, the present invention is not limited to this. For example, as shown in FIG. A conical surface portion 22 that does not come into contact with the inner peripheral surface 10 a may be provided on the left side of the outer peripheral surface portion 21. By providing the conical surface portion 22 in this manner, the conical surface portion 22 serves as a guide surface, thereby providing an advantage that the refrigerant flow is smoothed.

  Further, in the variable orifice device 1 of the present embodiment, the front end side case including the large diameter portion 12A and the lateral through hole 30 in order to precisely seal the flow path, assemble to the variable orifice device, and adjust the flow rate. Although the portion 12 is made of metal, the distal end side case portion 12 may be made of resin like the base end side case portion 11.

  Further, in this embodiment, the metal conduit 8 is subjected to spinning processing to form the annular groove 8a, and the annular groove 8a is fitted into the ring groove 13 of the large diameter portion 12A to seal the flow path. Although the assembly to the variable orifice device is performed, an O-ring may be attached to the ring groove 13 of the large diameter portion 12A to seal the flow path instead of the spinning process.

  Moreover, in the said Example, although the high voltage | pressure refrigerant | coolant was flowed toward the one end side (left end side) from the other end side (right end side) of a variable orifice apparatus, contrary to this, from one end side (left end side) You may comprise so that a refrigerant | coolant may flow toward the other end side (right end side).

DESCRIPTION OF SYMBOLS 1 Variable orifice apparatus 8 Conduit 10 Orifice case 11 Base end side case part 11A Valve body fixing female thread part 11B Cylindrical part 11C Connecting female thread part 12 Tip side case part 12A Large diameter part 12B Perforated cylindrical part 12C Connecting male thread Part 19 Lock nut 20 Valve body 21 Contact outer peripheral surface part 22 Conical surface part 23 Base end part 24 Male thread part 26 Minus groove 30 Transverse hole 32 Arc-shaped opening part ΔL Separation distance (valve opening)
S Effective opening area

Claims (8)

A cylindrical orifice case having a through-hole opened in a peripheral side portion at one end side, and a base end portion of the orifice case that is telescopically inserted into the orifice case so as to change an effective opening area of the through-hole. Comprises a rod-shaped valve body fixed to the other end side of the orifice case,
The effective opening area of the side through hole is changed according to the difference in expansion / contraction amount between the orifice case and the valve body according to the temperature change of the fluid, thereby automatically adjusting the flow rate of the fluid passing through the orifice case. Variable orifice device.   The valve body has a contact outer peripheral surface portion that abuts an inner peripheral surface of the orifice case around the lateral hole, and according to a difference in expansion / contraction amount between the orifice case and the valve body accompanying a temperature change of fluid. The distance between the one end of the through hole and the one end of the contact outer peripheral surface portion is changed, whereby the effective opening area of the through hole is changed. A variable orifice device according to claim 1.   The variable orifice device according to claim 1 or 2, wherein a large-diameter portion is formed on one end side of the orifice case, and the through-hole is formed in the vicinity of the large-diameter portion.   The orifice case includes a metal or resin tip side case portion including the large diameter portion and the lateral through hole, and a resin base end side case in which a base end portion of the valve body is fixed to the other end portion. The variable orifice device according to claim 3, wherein the valve body is formed of a metal rod-shaped body.   The valve body has a round bar shape, one end surface of the valve body has a vertical cut surface, and the entire outer peripheral surface on one end side of the valve body forms the contact outer peripheral surface portion. 2. The variable orifice device according to 2.   The variable orifice device according to claim 2, wherein the valve body has a round bar shape, and a conical surface portion and the contact outer peripheral surface portion are sequentially arranged on one end side of the valve body.   The variable orifice device according to any one of claims 1 to 6, wherein the orifice case has a stepped cylindrical shape.   The variable orifice device according to any one of claims 1 to 7, wherein the transverse hole has a circular shape, an elliptical shape, or a polygonal shape.

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