Control valve

Abstract

To provide a control valve which can be prevented from being assembled into a pipe line in an inclined state.SOLUTION: A variable orifice device 1 includes a case 10 having a valve port 34 through which fluid flows, and a valve body 40 accommodated in the case 10. The case 10 has a cylindrical case body 20, and a seat 30 attached to a first end 21 of the case body 20 and having a valve port 34. An inner peripheral surface of the first end 21 of the case body 20 is provided with a case female thread 21c. An outer peripheral surface of the seat 30 is provided with a seat male thread 30c engaged with the case female thread 21c.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a control valve that controls the flow rate according to the temperature of a fluid flowing through a flow path.

Background Art

[0002] An example of a conventional control valve is disclosed in Patent Document 1. This control valve is incorporated, for example, in a pipe (flow path) through which a fluid such as a refrigerant flows. The control valve has a case and a valve body. The case is made of resin and has a cylindrical shape. The valve body is made of metal and has a round bar shape. The valve body is housed in the case. A valve port and a lateral hole are provided at the first end of the case. The first end of the valve body faces the valve port. The second end of the valve body is attached to the second end of the case by a screw structure. The fluid flowing through the pipe enters the case from the lateral hole and exits from the valve port of the case.

[0003] When the temperature of the fluid flowing through the pipe changes, the case and the valve body expand and contract. The opening area of the valve port changes due to the difference in the amount of expansion and contraction of the case and the valve body. Therefore, the control valve can automatically control the flow rate of the fluid according to the temperature of the fluid flowing through the pipe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the control valve, the flow rate controllability, which is the relationship between the temperature of the fluid and the flow rate of the fluid in the control valve, is adjusted by rotating the valve body around the central axis and moving it in the central axis direction with respect to the case. Then, the second end of the valve body is fixed to the second end of the case by a lock nut.

[0006] The first end of the case is fixed to the conduit. The second end of the case is positioned at a distance from the inner surface of the conduit. As a result, the weight of the lock nut may cause the control valve to be installed in the conduit at an angle.

[0007] Furthermore, the control valve in Patent Document 2 has a small gap between the lock nut and the pipeline, making it difficult to insert a tool to turn the lock nut into the pipeline. Therefore, it is difficult to adjust the flow control after the control valve has been installed in the pipeline.

[0008] Therefore, the present invention aims to provide a control valve that can prevent it from being installed in a piping system in an inclined state. [Means for solving the problem]

[0009] To achieve the above objective, a control valve according to one aspect of the present invention comprises a case having a valve port through which a fluid flows, and a valve body housed in the case, wherein the opening area of ​​the valve port changes due to the difference in the amount of expansion and contraction of the case and the valve body caused by a change in the temperature of the fluid, and the case comprises a cylindrical case body and a seat having the valve port attached to the first end of the case body, wherein a female case thread is provided on the inner circumferential surface of the case body, and a male seat thread is provided on the outer circumferential surface of the seat that is screwed into the female case thread.

[0010] In the present invention, it is preferable that the case further has a set screw which is screwed into the female thread of the case and fixes the seat to the case body, and the set screw has a fluid passage which connects the valve port to the outside of the case body.

[0011] In the present invention, it is preferable that the portion of the case body at the first end to which the sheet is screwed is deformed to reduce its diameter.

[0012] In the present invention, it is preferable that the valve body has a rod-shaped or cylindrical shaft portion and a valve portion connected to the first end of the shaft portion and facing the valve opening, and that at least the case body and the shaft portion are made of resin.

[0013] In the present invention, Let α1 be the coefficient of linear expansion and β1 be the swelling elongation of the resin constituting the valve body. Let α2 be the coefficient of linear expansion and β2 be the swelling elongation of the resin constituting the case. Let L1 be the length of the portion of the valve body that expands or contracts in response to the temperature change of the fluid. Let L2 be the length of the portion in the case that expands or contracts in response to the temperature change of the fluid. When Dt is the difference between the upper and lower temperature limits of the operating temperature range of the fluid, It is preferable that the following equation (1) is satisfied. (α2×Dt×L2)-(α1×Dt×L1)>|(β2×L2)-(β1×L1)| ...(1)

[0014] In the present invention, Let α1 be the coefficient of linear expansion and β1 be the swelling elongation of the resin constituting the valve body. Let α2 be the coefficient of linear expansion and β2 be the swelling elongation of the resin constituting the case. Let L1 be the length of the portion of the valve body that expands or contracts in response to the temperature change of the fluid. When L2 is the length of the portion that expands or contracts in response to the temperature change of the fluid in the above case, It is preferable that the following equation (2) is satisfied. (α2×L2)-(α1×L1)>|(β2×L2)-(β1×L1)| ...(2)

[0015] In the present invention, Let β1 be the swelling elongation rate of the resin constituting the valve body. When the swelling elongation rate of the resin constituting the case is β2, It is preferable that the following equation (3) is satisfied. (β2 × L2) - (β1 × L1) = 0 ···(3)

[0016] In the present invention, when the temperature of the fluid is the lower limit temperature of the operating temperature range, the valve portion contacts the seat, and the force pressing the valve portion against the seat is not more than the lowest allowable stress among the allowable stresses of the materials constituting the case and the valve body, which is preferable.

[0017] In the present invention, it is preferable that the coefficient of linear expansion of the resin constituting the valve body is different from the coefficient of linear expansion of the resin constituting the case.

[0018] In the present invention, it is preferable that the case has a valve chamber in which the valve portion is disposed and a lateral hole connecting the valve chamber and the outside of the case.

[0019] In the present invention, it is preferable that a flow hole is provided on the outer peripheral surface of the case body, and the flow hole is connected to the inner space of the case body.

[0020] In the present invention, it is preferable that a flow hole is provided on the end surface of the second end side of the case body, and the flow hole is connected to the inner space of the case body.

[0021] In the present invention, the shaft portion has a cylindrical shape, the second end of the shaft portion is exposed outside the case, a flow hole is provided on the end surface of the second end side of the shaft portion, and the flow hole is connected to the inner space of the shaft portion, which is preferable.

[0022] In the present invention, at least the second end of the shaft portion is exposed outside the case, a flow groove is provided on the outer peripheral surface of the shaft portion, and the flow groove extends from a portion disposed in the inner space of the case body in the shaft portion to a portion exposed outside the case, which is preferable.

Advantages of the Invention

[0023] According to the present invention, a female thread is provided on the inner circumferential surface of the first end of the case body, and a male thread is provided on the outer circumferential surface of the seat that is screwed into the female thread. This allows the valve body to be fixed to the case body, and the flow control of the control valve can be adjusted by rotating the seat screwed to the case body around its central axis. As a result, a lock nut placed at the second end of the case body is unnecessary, and the weight of the lock nut can prevent the control valve from being installed in the pipeline in a tilted position. [Brief explanation of the drawing]

[0024] [Figure 1] This figure shows a variable orifice device according to one embodiment of the present invention incorporated into a pipeline. [Figure 2] This is a diagram showing a variable orifice device. [Figure 3] This is a magnified view showing the vicinity of the variable orifice device. [Figure 4] This figure shows a first modified example of the sheet fixing structure for a variable orifice device. [Figure 5] This figure shows a second modified example of the sheet fixing structure for a variable orifice device. [Figure 6] This figure shows a third modified example of the sheet fixing structure for a variable orifice device. [Figure 7] This figure shows a first modified example of the valve body fixing structure of a variable orifice device. [Figure 8] This figure shows a second modified example of the valve body fixing structure for a variable orifice device. [Figure 9] This figure shows a third modified example of the valve body fixing structure of a variable orifice device. [Figure 10] This figure shows a fourth modified example of the valve body fixing structure of a variable orifice device. [Figure 11] This figure shows a fifth modified example of the valve body fixing structure for a variable orifice device. [Figure 12] This figure shows a sixth modified example of the valve body fixing structure for a variable orifice device. [Figure 13] This figure shows the seventh modified example of the valve body fixing structure for a variable orifice device. [Figure 14] This figure shows the eighth modified example of the valve body fixing structure of a variable orifice device. [Figure 15] This figure shows the ninth modified example of the valve body fixing structure of a variable orifice device. [Figure 16] This figure shows a first modified example of a variable orifice device. [Figure 17] This figure shows a second modified example of a variable orifice device. [Figure 18] This figure shows a third modified example of a variable orifice device. [Figure 19] This figure shows a fourth modified example of a variable orifice device. [Figure 20] This figure shows the fifth modified example of a variable orifice device. [Figure 21] This figure shows the sixth modified example of a variable orifice device. [Figure 22] This figure shows the seventh modified example of a variable orifice device. [Modes for carrying out the invention]

[0025] A variable orifice device according to one embodiment of the present invention will be described below with reference to Figures 1 to 22. The variable orifice device is an example of a control valve.

[0026] Figure 1 shows a variable orifice device according to one embodiment of the present invention incorporated into a pipeline. Figure 2 shows the variable orifice device. Figure 3 is an enlarged view showing the vicinity of the variable orifice device. Figures 4 to 6 show the first to third modified examples of the fixing structure of the sheet of the variable orifice device. Figures 7 to 15 show the first to ninth modified examples of the fixing structure of the valve body of the variable orifice device. Figures 16 to 22 show the first to seventh modified examples of the variable orifice device.

[0027] Figures 2A, 16A, 17A, 18A, 19A, 20A, 21A, and 22A are plan views of the variable orifice device.

[0028] Figures 1A, 2B, 3B, 4B, 5B, 6B, 7A, 8A, 9A, 10A, 11A, 12A, 13A, 14A, 15A, 16B, 17B, 18B, 19B, 20B, 21B, and 22B are cross-sectional views along the central axis of the variable orifice device. In Figures 1A, 2B, 3B, 4B, 5B, 6B, 16B, 17B, 18B, 19B, 20B, and 21B, the valve body is shown viewed from the front.

[0029] Figures 1B, 2C, 3A, 4A, 5A, 6A, 16C, 17C, 18C, 19C, 20C, 21C, and 22C are left side views. Figures 1C, 2D, 7B, 8B, 9B, 10B, 11B, 12B, 13B, 14B, 15B, 15C, 16D, 17D, 18D, 19D, 20D, 21D, and 22D are right side views. The dashed line in Figure 1A represents the central axis of the case body of the variable orifice device. The left-right direction in the plan view and cross-sectional view is the central axis direction.

[0030] The variable orifice device according to this embodiment is incorporated into the piping of an air conditioning system. The variable orifice device controls the flow rate of the fluid (refrigerant) flowing through the piping. For example, the variable orifice device increases the flow rate when the fluid temperature rises and decreases the flow rate when the fluid temperature falls.

[0031] As shown in Figures 1 to 3, the variable orifice device 1 comprises a case 10 and a valve body 40. The variable orifice device 1 is incorporated into the pipeline 100.

[0032] Case 10 comprises a case body 20, a seat 30, and a set screw 38.

[0033] The case body 20 is made of a resin such as polyamide (PA). The case body 20 may also be made of a metal such as stainless steel, brass, or aluminum alloy. The case body 20 has a cylindrical shape. The case body 20 may also have a rectangular shape. The case body 20 has openings on both end faces. The inner circumferential surface of the first end 21 of the case body 20 is provided with a case female thread 21c. The inner diameter of the second end 22 of the case body 20 is smaller than the inner diameter of the central part of the case body 20 (the part between the first end 21 (case female thread 21c) and the second end 22). The space defined by the inner circumferential surface of the central part of the case body 20 has an inner space 24 and a valve chamber 25. The valve chamber 25 is connected to the inner space 24. The valve chamber 25 is located closer to the first end 21, and the inner space 24 is located closer to the second end 22.

[0034] The case body 20 has one or more lateral holes 23. In this embodiment, as an example, the case body 20 has two lateral holes 23. The two lateral holes 23 are, for example, circular holes and penetrate from the outer circumferential surface to the inner circumferential surface of the case body 20. The two lateral holes 23 are adjacent to the second end 22 side of the case female thread 21c. The two lateral holes 23 are connected to the valve chamber 25. The two lateral holes 23 connect the valve chamber 25 to the outside of the case 10. The two lateral holes 23 face each other in the vertical direction.

[0035] A support portion 26 is provided on the outer circumferential surface of the first end 21 of the case body 20. The support portion 26 is an annular projection and is arranged over the entire circumferential direction on the outer circumferential surface of the first end 21. The outer diameter of the support portion 26 is the same as the inner diameter of the conduit 100. The outer diameter of the support portion 26 may be smaller than the inner diameter of the conduit 100, as long as it can be fixed to the conduit 100 when the conduit 100 is deformed to reduce its diameter. The positions of the support portion 26 and the case female thread 21c in the axial direction overlap. The support portion 26 has an annular groove 26a. The annular groove 26a is located in the center in the width direction of the outer circumferential surface of the support portion 26. The annular groove 26a is arranged over the entire circumferential direction on the outer circumferential surface of the support portion 26.

[0036] The first end 21 of the case body 20 includes one end of the case body 20 (the left end in Figures 2A and 2B) and its vicinity. The second end 22 of the case body 20 includes the other end of the case body 20 (the right end in Figures 2A and 2B) and its vicinity.

[0037] The seat 30 is made of a metal such as stainless steel, brass, or aluminum alloy. The seat 30 may also be made of resin, for example. The outer circumferential surface of the seat 30 is provided with a seat male thread 30c. The seat male thread 30c is screwed into the case female thread 21c. The seat 30 has a valve opening 34 and a valve seat 35. The valve opening 34 penetrates the seat 30 in the direction of the central axis. The first portion 34a on the first end side (left side in each cross-sectional view) of the valve opening 34 is shaped such that a tool for rotating the seat 30 around its central axis can be inserted and the tool can engage in the rotational direction. The first portion 34a is formed to accommodate a hexagonal wrench, which is an example of a tool. The first portion 34a is a regular hexagonal hole. The second portion 34b on the second end side (right side in each cross-sectional view) of the valve opening 34 is a circular hole. The outer diameter of the second portion 34b is smaller than the outer diameter of the first portion 34a. The valve seat 35 is located on the end face of the seat 30 at the second end. The valve seat 35 surrounds the valve opening 34, which opens into the valve chamber 25.

[0038] The set screw 38 is made of a metal such as stainless steel, brass, or aluminum alloy. The set screw 38 may also be made of resin. A male thread 38c is provided on the outer surface of the set screw 38. The male thread 38c is screwed into the female thread 21c of the case. The set screw 38 has a fluid passage 39. The fluid passage 39 passes through the set screw 38 in the direction of its central axis. The fluid passage 39 is shaped such that a tool can be inserted to rotate the set screw 38 around its central axis, and the tool can engage in the rotational direction. The fluid passage 39 is formed to accommodate a hexagonal wrench, which is an example of a tool. The fluid passage 39 is a regular hexagonal hole identical to the first portion 34a of the valve port 34. The fluid passage 39 connects the valve port 34 to the outside of the case body 20. The set screw 38 is attached to the case body 20 together with the seat 30 by a screw structure, fixing the seat 30 to the case body 20.

[0039] The valve body 40 is housed in the case 10. The valve body 40 integrally comprises a shaft portion 50 and a valve portion 60.

[0040] The shaft portion 50 is made of a resin such as polyphenylene sulfide (PPS). Preferably, the shaft portion 50 is made of a different type of resin than the case body 20. The shaft portion 50 may also be made of a metal such as stainless steel, brass, or aluminum alloy. The shaft portion 50 has a round bar shape. The shaft portion 50 may also have a cylindrical shape. The outer diameter of the shaft portion 50 is constant along the entire axis of the central axis. The valve portion 60 is coaxially connected to the first end 51 of the shaft portion 50. The end face of the shaft portion 50 on the second end 52 side is flush with the end face of the case body 20 on the second end 22 side.

[0041] The second end 52 of the shaft portion 50 is fixed to the second end 22 of the case body 20. Specifically, the inner diameter of the central part of the case body 20 (the diameter of the inner space 24) is slightly larger than the outer diameter of the shaft portion 50, the inner diameter of the second end 22 of the case body 20 is smaller than the outer diameter of the shaft portion 50, and the second end 52 of the shaft portion 50 is press-fitted into the second end 22 of the case body 20. The portion of the shaft portion 50 other than the second end 52 is located in the inner space 24, and this portion is supported by the central part of the case body 20 so as to be expandable and contractible in the direction of the central axis. Alternatively, the second end 52 of the shaft portion 50 may be joined to the second end 22 of the case body 20 by adhesive. Alternatively, if both the case body 20 and the shaft portion 50 are made of resin, the second end 52 of the shaft portion 50 may be joined to the second end 22 of the case body 20 by welding. In addition, in configurations where the second end 52 of the shaft portion 50 is fixed to the second end 22 of the case body 20 by fixing means other than press-fitting, such as bonding with adhesive or welding, the second end 52 of the shaft portion 50 is not limited to being press-fitted into the second end 22 of the case body 20. For example, the outer diameter of the second end 52 of the shaft portion 50 may be set to be the same diameter as the inner diameter of the second end 22 of the case body 20.

[0042] The first end 51 of the shaft portion 50 includes one end of the shaft portion 50 (the left end in Figure 2B) and its vicinity. The second end 52 of the shaft portion 50 includes the other end of the shaft portion 50 (the right end in Figure 2B) and its vicinity.

[0043] The valve portion 60 is made of a metal such as stainless steel, brass, or aluminum alloy. The valve portion 60 may also be made of a resin such as PPS, and may be integrally molded with the shaft portion 50 in resin. The valve portion 60 has a cylindrical shape. The outer diameter of the valve portion 60 is smaller than the outer diameter of the shaft portion 50 and larger than the inner diameter of the second portion 34b of the valve opening 34. The tip 61 of the valve portion 60 has a conical shape. The valve portion 60 is positioned in the valve chamber 25. The tip 61 of the valve portion 60 faces the valve opening 34 in the direction of the central axis.

[0044] The fluid flowing through the pipeline 100 flows into the valve chamber 25 through the lateral hole 23 and flows out of the valve chamber 25 through the valve port 34 and fluid passage 39 back into the pipeline 100. Alternatively, the fluid flowing through the pipeline 100 flows into the valve chamber 25 through the fluid passage 39 and valve port 34 and flows out of the valve chamber 25 through the lateral hole 23 back into the pipeline 100. The opening area of ​​the valve port 34 changes due to the difference in the amount of expansion and contraction of the case 10 and valve body 40 that occurs in response to changes in the temperature of the fluid.

[0045] As an example, the variable orifice device 1 is configured such that the tip 61 of the valve portion 60 contacts the valve seat 35 from the valve body 40 side to close the valve opening 34. However, the variable orifice device 1 is not limited to a configuration in which the valve portion 60 contacts the valve seat 35, which is the opening edge of the valve opening 34, to close the valve opening 34. In other examples, the variable orifice device 1 may not be configured such that the valve portion 60 contacts the edge of the valve opening 34, but rather the valve portion 60 enters the valve opening 40 and closes the valve opening 34 with the outer circumferential surface of the valve portion 60 and the inner circumferential surface of the valve opening 34, or a flow path may be created with the outer circumferential surface of the valve portion 60 and the inner circumferential surface of the valve opening 34. That is, in this modified example, the valve portion 60 is formed in a shape that can enter the valve opening 34. Furthermore, the valve portion 60 may be formed in such a shape that when the valve portion 60 enters the valve opening 34, its outer surface makes surface contact with the inner surface of the valve opening 34, thereby closing the valve opening 34. Alternatively, the valve portion 60 may be formed in such a shape that when it enters the valve opening 34, it forms a gap (minimum throttling passage) between itself and the inner surface of the valve opening 34, allowing a small amount of fluid to flow.

[0046] Alternatively, the outer diameter of the valve portion 60 may be the same as the inner diameter of the central part of the case body 20 (the diameter of the valve chamber 25), and the valve portion 60 may face the lateral hole 23 radially. In this way, the lateral hole 23 becomes the valve opening, and the opening area of ​​the lateral hole 23 changes due to the difference in the amount of expansion and contraction of the case 10 and the valve body 40 that occurs in response to changes in the temperature of the fluid.

[0047] In the variable orifice device 1, the case body 20, the seat 30 (valve port 34), the set screw 38 (fluid passage 39), and the valve body 40 (shaft portion 50, valve portion 60) have their respective central axes aligned.

[0048] The variable orifice device 1 can be assembled, for example, as follows:

[0049] The valve body 40 is inserted into the case body 20 through the opening on the end face of the first end 21, with the second end 52 of the shaft portion 50 leading. The second end 52 of the shaft portion 50 of the valve body 40 is press-fitted into the second end 22 of the case body 20. The valve portion 60 of the valve body 40 is positioned in the valve chamber 25. The seat male thread 30c of the seat 30 is screwed into the case female thread 21c of the case body 20, and the seat 30 is attached to the case body 20. The valve portion 60 of the valve body 40 faces the valve opening 34.

[0050] Next, the variable orifice device 1 is installed in the pipeline connected to the test apparatus. The test apparatus is used in the assembly process of the variable orifice device 1 and is a device that can set the temperature of the fluid (e.g., air) flowing through the pipeline to an arbitrary value. The test apparatus flows a fluid at a predetermined temperature through the pipeline at a constant flow rate. A hex wrench is inserted into the first part 34a of the valve port 34 of the seat 30 and the seat 30 is rotated around its central axis so that the flow rate of the fluid passing through the valve port 34 of the variable orifice device 1 becomes a set value corresponding to the fluid temperature. Depending on the direction of rotation, the seat 30 moves closer to or away from the valve portion 60. When the flow rate of the fluid passing through the valve port 34 reaches the set value, the set screw 38 is screwed into the female thread 21c of the case. A hex wrench is inserted into the fluid passage 39 of the set screw 38 and the set screw 38 is rotated around its central axis and tightened so that the set screw 38 contacts the seat 30, fixing the seat 30 to the case body 20. In this way, the variable orifice device 1 is assembled and the flow controllability is adjusted.

[0051] The variable orifice device 1 is inserted into the piping 100 of the air conditioning system. If the outer diameter of the support portion 26 is the same as the inner diameter of the piping 100, the outer surface of the support portion 26 slides into contact with the inner surface of the piping 100. The variable orifice device 1 is fixed to the piping 100 by the diameter reduction deformation of the portion of the piping 100 corresponding to the annular groove 26a. Alternatively, the variable orifice device 1 may be fixed to the piping 100 by fitting an O-ring into the annular groove 26a and pushing it into the piping 100.

[0052] The variable orifice device 1 expands and contracts its case 10 and valve body 40 in response to the temperature of the fluid flowing through the pipeline 100. The difference in the amount of expansion and contraction between the case 10 and valve body 40 causes the valve portion 60 of the valve body 40 to move closer to or further away from the valve port 34, thereby changing the opening area of ​​the valve port 34. As a result, the flow rate of the fluid flowing through the valve port 34 is automatically controlled according to the fluid temperature.

[0053] The variable orifice device 1 satisfies the following equation (1), where α1 is the coefficient of linear expansion and β1 is the swelling elongation of the resin constituting the valve body 40 (shaft portion 50), α2 is the coefficient of linear expansion and β2 is the swelling elongation of the resin constituting the case 10 (case body 20), L1 is the length of the portion in the valve body 40 that expands and contracts in response to the temperature change of the fluid, L2 is the length of the portion in the case 10 that expands and contracts in response to the temperature change of the fluid, and Dt is the difference between the upper limit temperature t2 and the lower limit temperature t1 of the operating temperature range of the fluid. (α2×Dt×L2)-(α1×Dt×L1)>|(β2×L2)-(β1×L1)| ...(1)

[0054] The "coefficient of linear expansion," also known as the "coefficient of linear thermal expansion" (JIS K6900), is the reversible change in the length of a material per unit length per degree Celsius of temperature change. Specifically, when the temperature change is ΔT, the length of the material before the temperature change is N1, and the length of the material after the temperature change is N2, the coefficient of linear expansion α of the material is given by the following formula. α = (N2 - N1) / (N1 × ΔT)

[0055] Resins have the property of increasing in volume when immersed in a liquid or exposed to vapor. This property is called "swelling" (JIS K6900). "Swelling elongation" is the change in length of the material per unit length due to swelling. Specifically, if the length of the material before swelling is N1 and the length of the material after the volume increase due to swelling has saturated is N2, the swelling elongation β of the material is given by the following formula. β = (N2 - N1) / N1

[0056] In this way, the difference in the amount of expansion and contraction of case 10 and valve body 40 that occurs when the fluid temperature changes from the lower limit temperature t1 to the upper limit temperature t2 (left side of equation (1)) becomes larger than the difference in the amount of expansion of case 10 and valve body 40 that occurs due to swelling (right side of the same equation). Therefore, changes in the flow controllability of the variable orifice device 1 caused by swelling can be effectively suppressed.

[0057] Alternatively, the variable orifice device 1 may be configured to satisfy the following equation (2). (α2×L2)-(α1×L1)>|(β2×L2)-(β1×L1)| ...(2)

[0058] In this way, the difference in the amount of expansion and contraction of case 10 and valve body 40 that occurs when the fluid temperature changes by a unit temperature (1 degree) (left side of equation (2)) becomes larger than the difference in the amount of expansion and contraction of case 10 and valve body 40 that occurs due to swelling (right side of the same equation). Therefore, the difference in the amount of expansion and contraction due to swelling becomes sufficiently small compared to the difference in the amount of expansion and contraction due to temperature change, and the change in the flow controllability of the variable orifice device 1 caused by swelling can be suppressed more effectively.

[0059] Alternatively, the variable orifice device 1 may be configured to satisfy the following equation (3). (β2 × L2) - (β1 × L1) = 0 ... (3)

[0060] In this way, the amount of expansion of case 10 due to swelling (the first term on the left side of equation (3)) and the amount of expansion of valve body 40 (the second term) become the same. Therefore, the effect of swelling on the flow controllability of the variable orifice device 1 can be eliminated.

[0061] For example, when the swelling elongation rate β1 is 0.12 and the swelling elongation rate β2 is 0.15, length L1 is set to 100 mm and length L2 is set to 80 mm. By doing so, equation (3) above is satisfied, and the effect of swelling on the flow controllability of the variable orifice device 1 can be eliminated.

[0062] Furthermore, since the variable orifice device 1 includes tolerances for component dimensions and material properties, the above equations (1) to (3) also include tolerance ranges. In particular, equation (3) includes cases where the value on the left side is strictly 0, and cases where it is a value within a range other than 0 that arises from tolerances.

[0063] Furthermore, in the variable orifice device 1, the linear expansion coefficient α1 of the resin constituting the valve body 40 and the linear expansion coefficient α2 of the resin constituting the case 10 may be different. By doing so, the difference in the amount of expansion and contraction of the case 10 and the valve body 40 caused by the temperature change of the fluid can be made relatively large. Note that the linear expansion coefficients α1 and α2 may be the same.

[0064] As described above, the variable orifice device 1 comprises a case 10 having a valve port 34 through which fluid flows, and a valve body 40 housed in the case 10. The variable orifice device 1 changes the opening area of ​​the valve port 34 due to the difference in the amount of expansion and contraction of the case 10 and the valve body 40 that occurs in response to changes in the temperature of the fluid. The case 10 comprises a cylindrical case body 20 and a seat 30 having a valve port 34 attached to the first end 21 of the case body 20. A female case thread 21c is provided on the inner circumferential surface of the first end 21 of the case body 20, and a male seat thread 30c that is screwed into the female case thread 21c is provided on the outer circumferential surface of the seat 30.

[0065] In this way, the valve body 40 is fixed to the case body 20, and the flow control of the variable orifice device 1 can be adjusted by rotating the seat 30, which is screwed onto the case body 20, around its central axis. Therefore, it is possible to prevent the variable orifice device from being installed in the pipeline 100 in a tilted state due to the weight of the lock nut, as is the case with conventional variable orifice devices. In addition, by making the shape of the valve opening 34 suitable for relatively thin tools such as a hexagonal wrench, the flow control can be adjusted by rotating the seat 30 after the variable orifice device 1 has been installed in the pipeline 100.

[0066] Furthermore, the case 10 has a set screw 38 that is screwed into the case female thread 21c and fixes the seat 30 to the case body 20. The set screw 38 has a fluid passage 39 that connects the valve port 34 to the outside of the case body 20. In this way, the seat 30 can be fixed to the case body 20 with a relatively simple fixing structure. In addition, by making the shape of the fluid passage 39 suitable for a relatively thin tool such as a hexagonal wrench, the set screw 38 can be rotated after the variable orifice device 1 has been installed in the pipeline 100.

[0067] Furthermore, the valve body 40 has a shaft portion 50 having a round bar shape and a valve portion 60 connected to the first end 51 of the shaft portion 50 and facing the valve port 34. The case body 20 and the shaft portion 50 are made of resin. This makes the variable orifice device 1 lighter compared to a configuration in which the case body 20 or the shaft portion 50 is made of metal. Therefore, it is possible to more effectively prevent the variable orifice device from being installed in the pipeline 100 in a tilted state. In addition, both the case 10 and the valve body 40 swell. Therefore, it is possible to suppress changes in the flow controllability of the variable orifice device 1 compared to a configuration in which only one of the case 10 or the valve body 40 swells.

[0068] Furthermore, the variable orifice device 1 may have a configuration in which the tip 61 of the valve portion 60 contacts the valve seat 35 of the seat 30 when the fluid temperature is at the lower limit temperature t1 of the operating temperature range. In this configuration, the force with which the tip 61 presses against the valve seat 35 is set to be less than or equal to the lowest allowable stress among the allowable stresses of the materials constituting the case 10 and the valve body 40. By doing so, deformation or breakage of the members can be suppressed when the case 10 and the valve body 40 stretch due to swelling.

[0069] Figures 4 to 6 show modified examples of the sheet fixing structure of the variable orifice device 1. In each modified example, the same reference numerals are used for parts identical to those in the variable orifice device 1, and detailed explanations are omitted.

[0070] The variable orifice device 1A shown in Figure 4 comprises a case 10A and a valve body 40. The case 10A comprises a case body 20, a seat 30, and a set screw 38A. The set screw 38A has a hexagonal bolt shape with a regular hexagonal head. In the variable orifice device 1A, the seat 30 is fixed to the case body 20 by the set screw 38A. In this way, it is not necessary to adapt the shape of the fluid passage 39 of the set screw 38A to the tool, and the flow area of ​​the fluid passage 39 can be made larger than the flow area of ​​the valve opening 34 (first portion 34a). Therefore, the fluid pressure loss can be reduced.

[0071] The variable orifice device 1B shown in Figure 5 comprises a case 10B and a valve body 40. The case 10B comprises a case body 20 and a seat 30. The case 10B does not have a set screw 38. In the variable orifice device 1B, the seat 30 is fixed to the case body 20 by screw adhesive (not shown).

[0072] The variable orifice device 1C shown in Figure 6 comprises a case 10C and a valve body 40. The case 10C comprises a case body 20C and a seat 30. The case 10C does not have a set screw 38. The annular groove 26a of the case body 20C is shallower than the annular groove 26a of the case body 20 of the variable orifice device 1. The seat 30 is screwed into a position corresponding to the annular groove 26a. The positions of the seat 30 and the annular groove 26a in the central axis direction overlap. The variable orifice device 1C is inserted into the conduit 100 of the air conditioning system and fixed to the conduit 100 by the diameter reduction deformation of the portion of the conduit 100 corresponding to the annular groove 26a. At this time, the portion of the case body 20C corresponding to the annular groove 26a is also diameter reduction deformation, and the seat 30 is fixed to the case body 20C.

[0073] Figures 7 to 15 show modified examples of the valve body fixing structure of the variable orifice device 1. In each modified example, the same reference numerals are used for parts identical to those in the variable orifice device 1, and detailed explanations are omitted.

[0074] The variable orifice device 1D shown in Figure 7 comprises a case 10D and a valve body 40. The case 10D comprises a case body 20D, a seat 30, and a set screw 38. The case body 20D has an open first end 21 and a closed second end 22. The valve body 40 is fixed to the case body 20D by press-fitting the second end 52 of the shaft portion 50 into the case body 20D until it abuts against the wall of the second end 22 of the case body 20D.

[0075] The variable orifice device 1E shown in Figure 8 comprises a case 10E, a valve body 40E, and a key 71E. The case 10E comprises a case body 20E, a seat 30, and a set screw 38. A keyway 22e is provided at the second end 22 of the case body 20E. The valve body 40E comprises a shaft portion 50E and a valve portion 60. A keyway 52e is provided at the second end 52 of the shaft portion 50E. The valve body 40E is fixed to the case body 20E by press-fitting a prismatic key 71E into the keyways 22e and 52e. The key 71E may have a shape other than a prismatic shape, such as a cylindrical shape.

[0076] The variable orifice device 1F shown in Figure 9 comprises a case 10F and a valve body 40F. The case 10F comprises a case body 20F, a seat 30, and a set screw 38. The inner diameter of the second end 22 of the case body 20F is larger than the inner diameter of the central part of the case body 20F. The valve body 40F comprises a shaft portion 50F and a valve portion 60. A press-fit portion 52f is provided on the outer circumferential surface of the second end 52 of the shaft portion 50F. The press-fit portion 52f is an annular projection and is arranged over the entire circumferential surface of the second end 52. The outer diameter of the press-fit portion 52f is larger than the inner diameter of the second end 22 of the case body 20F. The valve body 40F is fixed to the case body 20F by press-fitting the press-fit portion 52f into the second end 22 of the case body 20F.

[0077] The variable orifice device 1G shown in Figure 10 comprises a case 10G, a valve body 40G, and a valve body set screw 72G. The case 10G comprises a case body 20G, a seat 30, and a set screw 38. A screw hole 22g is provided at the second end 22 of the case body 20G. The valve body 40G comprises a shaft portion 50G and a valve portion 60. A flat portion 52g is provided at the second end 52 of the shaft portion 50G. At the second end 22 of the case body 20G, the screw hole 22g and the flat portion 52g face each other. The valve body set screw 72G is screwed into the screw hole 22g. The valve body 40G is fixed to the case body 20G by tightening the valve body set screw 72G so that it abuts against the flat portion 52g. The shaft portion 50G may not have a flat portion 52g, and in this configuration, the valve body set screw 72G is tightened so as to abut against the cylindrical outer surface of the shaft portion 50G.

[0078] The variable orifice device 1H shown in Figure 11 comprises a case 10H and a valve body 40H. The case 10H comprises a case body 20H, a seat 30, and a set screw 38. A locking groove 22h is provided on the inner circumferential surface of the second end 22 of the case body 20H. The locking groove 22h is arranged over the entire circumferential direction on the inner circumferential surface of the second end 22 of the case body 20H. The valve body 40H comprises a shaft portion 50H and a valve portion 60. A plurality of elastic pieces 52h are provided on the second end 52 of the shaft portion 50H. The plurality of elastic pieces 52h are elastically deformable in the radial direction. The plurality of elastic pieces 52h are arranged at equal intervals around the central axis. Locking projections 52h1 that engage with the locking groove 22h of the case body 20H are provided on the outer surfaces of the plurality of elastic pieces 52h. The plurality of elastic pieces 52h and the locking groove 22h constitute a snap-fit ​​structure. The valve body 40H is fixed to the case body 20H by the locking of multiple elastic pieces 52h into the locking grooves 22h.

[0079] The variable orifice device 1J shown in Figure 12 comprises a case 10J and a valve body 40J. The case 10J comprises a case body 20J, a seat 30, and a set screw 38. A plurality of elastic pieces 22j are provided at the second end 22 of the case body 20J. The plurality of elastic pieces 22j are elastically deformable in the radial direction. The plurality of elastic pieces 22j are arranged at equal intervals around the central axis. Locking projections 22j1 are provided on the inner surfaces of the plurality of elastic pieces 22j. The valve body 40J comprises a shaft portion 50J and a valve portion 60. A locking groove 52j is provided on the outer circumferential surface of the second end 52 of the shaft portion 50J, into which the locking projections 22j1 of the case body 20J engage. The locking groove 52j is arranged over the entire circumferential direction on the outer circumferential surface of the second end 52 of the shaft portion 50J. The plurality of elastic pieces 22j and the locking groove 52j constitute a snap-fit ​​structure. The valve body 40J is fixed to the case body 20J by the locking of multiple elastic pieces 22j into the locking grooves 52j.

[0080] The variable orifice device 1K shown in Figure 13 comprises a case 10K and a valve body 40K. The case 10K comprises a case body 20K, a seat 30, and a set screw 38. A female thread 22k is provided on the inner circumferential surface of the second end 22 of the case body 20K. The valve body 40K comprises a shaft portion 50K and a valve portion 60. A male thread 52k is provided on the outer circumferential surface of the second end 52 of the shaft portion 50K, which is screwed into the female thread 22k. A regular hexagonal hole is provided on the end face of the shaft portion 50K on the second end 52 side, into which a hexagonal wrench can be fitted. The valve body 40K is fixed to the case body 20K by screwing the male thread 52k of the shaft portion 50K into the female thread 22k of the case body 20K. The valve body 40K may be further fixed to the case body 20K with screw adhesive.

[0081] The variable orifice device 1M shown in Figure 14 comprises a case 10M and a valve body 40M. The case 10M comprises a case body 20M, a seat 30, and a set screw 38. Two locking recesses 22m are provided on the inner circumferential surface of the second end 22 of the case body 20M. The two locking recesses 22m extend in the circumferential direction. The two locking recesses 22m face each other in the radial direction. The valve body 40M comprises a shaft portion 50M and a valve portion 60. Two locking protrusions 52m are provided on the outer circumferential surface of the second end 52 of the shaft portion 50M. The opening 22b on the end face of the case body 20M on the second end 22 side has the same shape as the outer shape of the valve body 40M projected in the direction of the central axis. When the valve body 40M is inserted into the opening 22b on the second end 22 side of the case body 20M and the valve body 40M is rotated around its central axis, the two locking projections 52m engage with the two locking recesses 22m. The valve body 40M is fixed to the case body 20M by the locking projections 52m engaging with the locking recesses 22m.

[0082] The variable orifice device 1N shown in Figure 15 comprises a case 10N, a valve body 40N, and a pin 73N. The case 10N comprises a case body 20N, a seat 30, and a set screw 38. A pin hole 22n is provided at the second end 22 of the case body 20N. The valve body 40N comprises a shaft portion 50N and a valve portion 60. A pin hole 52n is provided at the second end 52 of the shaft portion 50N. The pin 73N is fitted into the pin hole 22n of the case body 20N and the pin hole 52n of the valve body 40N. The pin holes 22n and 52n and the pin 73N constitute a pin-fastening structure. The length of the pin 73N is slightly larger than the outer diameter of the case body 20N (Figure 15B). The length of pin 73N may be greater than the outer diameter of the case body 20N and slightly smaller than the inner diameter of the conduit 100 (Figure 15C). The valve body 40N is fixed to the case body 20N by fitting pin 73N into pin holes 22n and 52n.

[0083] Figures 16 to 22 show modified examples of the variable orifice device 1. In each modified example, components identical to those in the variable orifice device 1 are denoted by the same reference numerals, and detailed explanations are omitted.

[0084] The variable orifice device 1P shown in Figure 16 comprises a case 10P and a valve body 40. The case 10P comprises a case body 20P, a seat 30, and a set screw 38.

[0085] Multiple flow holes 27P are provided on the outer circumferential surface of the case body 20P. The multiple flow holes 27P are connected to the inner space 24 of the case body 20P. The multiple flow holes 27P penetrate from the outer circumferential surface to the inner circumferential surface of the case body 20P. The multiple flow holes 27P are circular holes. The multiple flow holes 27P may also be polygonal holes such as triangles, squares, or hexagons. The case body 20P has 10 flow holes 27P. The multiple flow holes 27P are arranged in two rows of 5 at equal intervals along the central axis. The flow holes 27P of one row and the flow holes 27P of the other row face each other in the vertical direction. The case body 20P may have only one flow hole 27P. Fluid flows between the outside and the inner space 24 of the case 10P through the multiple flow holes 27P.

[0086] The variable orifice device 1P has the same configuration as the variable orifice device 1, except that it has multiple flow holes 27P.

[0087] The variable orifice device 1Q shown in Figure 17 comprises a case 10Q and a valve body 40. The case 10Q comprises a case body 20Q, a seat 30, and a set screw 38.

[0088] Multiple flow holes 27Q are provided on the outer circumferential surface of the case body 20Q. The multiple flow holes 27Q are connected to the inner space 24 of the case body 20Q. The multiple flow holes 27Q penetrate from the outer circumferential surface to the inner circumferential surface of the case body 20Q. The multiple flow holes 27Q are oval-shaped holes. The case body 20Q has two flow holes 27Q. The two flow holes 27Q face each other in the vertical direction. The case body 20Q may have four flow holes 27Q, and the four flow holes 27Q may be arranged at equal intervals around a central axis. Fluid flows between the outside and the inner space 24 of the case 10Q through the multiple flow holes 27Q.

[0089] The variable orifice device 1Q has the same configuration as the variable orifice device 1, except that it has multiple flow holes 27Q.

[0090] The variable orifice device 1R shown in Figure 18 comprises a case 10R and a valve body 40. The case 10R comprises a case body 20R, a seat 30, and a set screw 38.

[0091] A flow hole 27R is provided on the outer circumferential surface of the case body 20R. The flow hole 27R is connected to the inner space 24 of the case body 20R. The flow hole 27R penetrates from the outer circumferential surface to the inner circumferential surface of the case body 20R. The flow hole 27R is a single helical hole. The case body 20R may have multiple flow holes 27R. Fluid flows between the outside and the inner space 24 of the case 10R through the flow hole 27R.

[0092] The variable orifice device 1R has the same configuration as the variable orifice device 1, except that it has a flow hole 27R.

[0093] The variable orifice device 1S shown in Figure 19 comprises a case 10S and a valve body 40. The case 10S comprises a case body 20S and a seat 30.

[0094] Multiple flow grooves 28S are provided on the inner circumferential surface of the case body 20S. The multiple flow grooves 28S extend in the direction of the central axis from the vicinity of the transverse hole 23 on the inner circumferential surface of the case body 20S to the end face on the second end 22 side. The case body 20S has two flow grooves 28S. The two flow grooves 28S face each other in a direction perpendicular to the vertical direction. The first end 28a of the multiple flow grooves 28S is located in the valve chamber 25, and the second end 28b is located on the end face on the second end 22 side of the case body 20S. The multiple flow grooves 28S extend from the valve chamber 25 through the inner space 24 to the outside of the case body 20S. The flow grooves 28S are flow holes connected to the inner space 24 of the case body 20S. That is, a flow hole (the second end 28b of the flow groove 28S) is provided on the end face on the second end 22 side of the case body 20S, and the flow hole is connected to the inner space 24 of the case body 20S. Fluid flows between the outer and inner spaces 24 of the case 10S through multiple flow grooves 28S.

[0095] The first end 28a of the flow groove 28S includes one end of the flow groove 28S (the left end in Figure 19B) and its vicinity. The second end 28b of the flow groove 28S includes the other end of the flow groove 28S (the right end in Figure 19B) and its vicinity.

[0096] The variable orifice device 1S has the same configuration as the variable orifice device 1, except that it has a plurality of flow grooves 28S.

[0097] The variable orifice device 1T shown in Figure 20 comprises a case 10T and a valve body 40. The case 10T comprises a case body 20T and a seat 30.

[0098] Multiple flow grooves 28T are provided on the inner circumferential surface of the case body 20T. The multiple flow grooves 28T extend in the direction of the central axis from the vicinity of the transverse hole 23 on the inner circumferential surface of the case body 20T to the end face on the second end 22 side. The case body 20T has six flow grooves 28T. The six flow grooves 28T are arranged at equal intervals around the central axis. The first end 28a of the multiple flow grooves 28T is located in the valve chamber 25, and the second end 28b is located on the end face on the second end 22 side of the case body 20T. The multiple flow grooves 28T extend from the valve chamber 25 through the inner space 24 to the outside of the case body 20T. The flow grooves 28T are flow holes connected to the inner space 24 of the case body 20T. That is, a flow hole (the second end 28b of the flow groove 28T) is provided on the end face on the second end 22 side of the case body 20T, and the flow hole is connected to the inner space 24 of the case body 20T. Fluid flows between the outer and inner spaces 24 of the case 10T through multiple flow grooves 28T.

[0099] The first end 28a of the flow groove 28T includes one end of the flow groove 28T (the left end in Figure 20B) and its vicinity. The second end 28b of the flow groove 28T includes the other end of the flow groove 28T (the right end in Figure 20B) and its vicinity.

[0100] The variable orifice device 1T has the same configuration as the variable orifice device 1, except that it has multiple flow grooves 28T.

[0101] The variable orifice device 1U shown in Figure 21 comprises a case 10 and a valve body 40U. The valve body 40U integrally comprises a shaft portion 50U and a valve portion 60.

[0102] The second end 52 of the shaft portion 50U is fixed to the second end 22 of the case body 20 of the case 10 by fixing means such as press-fitting, welding, or adhesive bonding. The end face of the second end 52 of the shaft portion 50U is positioned flush with the second end 22 of the case body 20. The end face of the second end 52 of the shaft portion 50U may be positioned inside the case body 20 or outside the case body 20. In other words, at least the second end 52 of the shaft portion 50U must be exposed to the outside of the case 10. "A configuration in which the second end 52 is exposed to the outside of the case 10" means "a configuration in which the second end 52 is visible from the outside of the case 10."

[0103] Multiple flow grooves 58U are provided on the outer circumferential surface of the shaft portion 50U. The multiple flow grooves 58U extend in the direction of the central axis from the first end 51 to the second end 52 of the shaft portion 50U. The shaft portion 50U has three flow grooves 58U. The shaft portion 50U may have only one flow groove 58U. The three flow grooves 58U are arranged at equal intervals around the central axis. The first end 58a of the multiple flow grooves 58U is located in the valve chamber 25, and the second end 58b is located on the end face of the shaft portion 50U on the second end 52 side (i.e., the end face of the case body 20 on the second end 22 side). The end face of the shaft portion 50U on the second end 52 side is exposed to the outside of the case 10. The multiple flow grooves 58U extend from the valve chamber 25 through the inner space 24 to the outside of the case body 20. The flow grooves 58U are flow holes connected to the inner space 24 of the case body 20. In other words, a flow hole (the second end 58b of the flow groove 58U) is provided on the end face of the case body 20 on the second end 22 side, and the flow hole is connected to the inner space 24 of the case body 20. Fluid flows between the outside of the case 10 and the inner space 24 through the multiple flow grooves 58U. The flow grooves 58U only need to extend from the portion of the shaft portion 50U that is located in the inner space 24 of the case body 20 to the portion that is exposed to the outside of the case 10.

[0104] The first end 58a of the flow channel 58U includes one end of the flow channel 58U (the left end in Figure 21B) and its vicinity. The second end 58b of the flow channel 58U includes the other end of the flow channel 58U (the right end in Figure 21B) and its vicinity.

[0105] The variable orifice device 1U has the same configuration as the variable orifice device 1, except that it has a plurality of flow grooves 58U.

[0106] The variable orifice device 1V shown in Figure 22 comprises a case 10 and a valve body 40V. The valve body 40V integrally includes a shaft portion 50V and a valve portion 60.

[0107] The shaft portion 50V has a cylindrical shape. An opening 54a is provided on the outer circumferential surface of the first end 51 of the shaft portion 50V, connected to an inner space 54V defined by the inner circumferential surface of the shaft portion 50V. The opening 54a is located in the valve chamber 25. An opening 54b is provided on the end face of the second end 52 of the shaft portion 50V, connected to the inner space 54V. The opening 54b is exposed to the outside of the case 10. The inner space 54V extends from the valve chamber 25 to the outside of the case body 20. The opening 54b is a flow hole connected to the inner space 54V of the shaft portion 50V. Fluid flows between the outside of the case 10 and the inner space 54V through the opening 54b.

[0108] The variable orifice device 1V has the same configuration as the variable orifice device 1, except that it has a cylindrical valve body 40V.

[0109] Variable orifice devices 1A-1H, 1J, 1K, 1M, 1N, and 1P-1V produce the same effects as variable orifice device 1.

[0110] In the variable orifice device 1P-1R, the fluid flowing through the conduit 100 flows into the inner space 24 through the flow holes 27P-27R. Therefore, the case body 20P-20R and the valve body 40 can expand and contract more quickly in response to changes in the fluid temperature.

[0111] In the variable orifice devices 1S and 1T, the fluid flowing through the conduit 100 flows into the inner space 24 through the flow grooves 28S and 28T. Therefore, the case bodies 20S and 20T and the valve body 40 can expand and contract more quickly in response to changes in the fluid temperature.

[0112] In the variable orifice device 1U, the fluid flowing through the conduit 100 flows into the inner space 24 through the flow groove 58U. Therefore, the case body 20 and valve body 40U can expand and contract more quickly in response to changes in the fluid temperature.

[0113] In the variable orifice device 1V, the fluid flowing through the conduit 100 flows into the inner space 54V through the opening 54b. Therefore, the valve body 40V can be expanded and contracted more quickly in response to changes in the fluid temperature.

[0114] In the variable orifice device 1P to 1V, if sufficient fluid flows between the outside of cases 10, 10P to 10T and the valve chamber 25 through the flow paths other than the lateral holes 23 (for example, the flow holes 27P to 27R, the flow grooves 28S, 28T, 58U, and the inner space 54V), the lateral holes 23 may be omitted.

[0115] In this specification, terms indicating shapes such as "cylinder" and "column" are also used to refer to members or parts of members that substantially have the shape of those terms. For example, "cylindrical member" includes both cylindrical members and substantially cylindrical members. Furthermore, in this specification, "identical" includes both being strictly identical and being substantially identical.

[0116] Although embodiments of the present invention have been described above, the present invention is not limited to the configurations of these embodiments. Additions, deletions, design modifications, and combinations of features of the embodiments, as appropriate by those skilled in the art, are also included within the scope of the present invention, as long as they do not contradict the spirit of the invention. [Explanation of Symbols]

[0117] 1, 1A~1H, 1J, 1K, 1M, 1N, 1P~1V... Variable orifice device 10, 10A~10H, 10J, 10K, 10M, 10N, 10P~10T…case 20, 20C~20H, 20J, 20K, 10M, 20N, 20P~20T…Case body 21...First end, 21c...Case female thread 22...Second end, 22b...Opening, 22e...Keyway, 22g...Screw hole, 22h...locking groove, 22j...elastic piece, 22j1...locking projection, 22k...female thread, 22m…locking recess, 22n…pin hole 23...Horizontal hole, 24...Inner space, 25...Valve chamber 26...Support section, 26a...Annular groove 27P, 27Q, 20R…Flow hole 28S, 28T...Flow groove, 28a...1st end, 28b...2nd end 30...sheet, 30c...sheet male screw 34...Valve port, 34a...First part, 34b...Second part, 35...Valve seat 38...Set screw, 38A...Set screw, 38c...Male screw 39...Fluid passage 40, 40E~40H, 40J, 40K, 40M, 40N, 40U, 40V... Valve body 50, 50E~50H, 50J, 50K, 50M, 50N, 50U, 50V...shaft part 51...1st end 52...Second end, 52e...Keyway, 52f...Press-fit section, 52g...Flat section 52h...Elastic piece, 52h1...Locking projection, 52j...Locking groove, 52k...Male screw 52m...locking protrusion, 52n...pin hole 54V…inner space, 54a…opening, 54b…opening 58U...Flow groove, 58a...1st end, 58b...2nd end 60... Valve section, 61... Tip 71E...Key, 72G...Valve body retaining screw, 73N...Pin 100…Pipe line

Claims

1. A control valve comprising a case having a valve opening through which a fluid flows, and a valve body housed in the case, wherein the opening area of ​​the valve opening changes due to the difference in the amount of expansion and contraction of the case and the valve body caused by a change in the temperature of the fluid, The case comprises a cylindrical case body and a seat having the valve opening attached to the first end of the case body. The inner circumferential surface of the case body is provided with a female thread for the case. The outer circumferential surface of the sheet is provided with a sheet male thread that is screwed into the case female thread, The valve body has a shaft portion having a rod shape or cylindrical shape, and a valve portion connected to the first end of the shaft portion and facing the valve opening, At least the case body and the shaft portion are made of resin, A control valve having a case that includes a valve chamber in which the valve portion is arranged, and a lateral hole connecting the valve chamber to the outside of the case.

2. A control valve having a case with a valve opening through which a fluid flows, and a valve body housed in the case, wherein the opening area of ​​the valve opening changes due to the difference in the amount of expansion and contraction of the case and the valve body caused by a change in the temperature of the fluid, The case comprises a cylindrical case body and a seat having the valve opening attached to the first end of the case body. The inner circumferential surface of the case body is provided with a female thread for the case. The outer circumferential surface of the sheet is provided with a sheet male thread that is screwed into the case female thread, The valve body has a shaft portion having a rod shape or cylindrical shape, and a valve portion connected to the first end of the shaft portion and facing the valve opening, At least the case body and the shaft portion are made of resin, A flow hole is provided on the end face of the second end of the case body. A control valve in which the flow hole is connected to the inner space of the case body.

3. A control valve having a case with a valve opening through which a fluid flows, and a valve body housed in the case, wherein the opening area of ​​the valve opening changes due to the difference in the amount of expansion and contraction of the case and the valve body caused by a change in the temperature of the fluid, The case comprises a cylindrical case body and a seat having the valve opening attached to the first end of the case body. The inner circumferential surface of the case body is provided with a female thread for the case. The outer circumferential surface of the sheet is provided with a sheet male thread that is screwed into the case female thread, The valve body has a cylindrical shaft portion and a valve portion connected to the first end of the shaft portion and facing the valve opening. At least the case body and the shaft portion are made of resin, The second end of the shaft portion is exposed to the outside of the case. A flow hole is provided on the end face of the second end of the shaft portion. A control valve in which the flow hole is connected to the inner space of the shaft portion.

4. A control valve comprising a case having a valve opening through which a fluid flows, and a valve body housed in the case, wherein the opening area of ​​the valve opening changes due to the difference in the amount of expansion and contraction of the case and the valve body caused by a change in the temperature of the fluid, The case comprises a cylindrical case body and a seat having the valve opening attached to the first end of the case body. The inner circumferential surface of the case body is provided with a female thread for the case. The outer circumferential surface of the sheet is provided with a sheet male thread that is screwed into the case female thread, The valve body has a shaft portion having a rod shape or cylindrical shape, and a valve portion connected to the first end of the shaft portion and facing the valve opening, At least the case body and the shaft portion are made of resin, At least the second end of the shaft portion is exposed to the outside of the case, A flow groove is provided on the outer circumferential surface of the shaft portion. A control valve in which the flow groove extends from a portion of the shaft located in the inner space of the case body to a portion exposed to the outside of the case body.

5. The case further has a set screw that is screwed into the female thread of the case and secures the sheet to the case body, The control valve according to any one of claims 1 to 4, wherein the set screw has a fluid passage connecting the valve port and the outside of the case body.

6. The control valve according to any one of claims 1 to 4, wherein the portion of the case body to which the seat is screwed at the first end is deformed to reduce its diameter.

7. Let α1 be the coefficient of linear expansion and β1 be the swelling elongation of the resin constituting the valve body. Let α2 be the coefficient of linear expansion and β2 be the swelling elongation of the resin constituting the case. Let L1 be the length of the portion of the valve body that expands or contracts in response to the temperature change of the fluid. Let L2 be the length of the portion in the case that expands or contracts in response to the temperature change of the fluid. When Dt is the difference between the upper and lower temperature limits of the operating temperature range of the fluid, A control valve according to any one of claims 1 to 4, satisfying the following formula (1). (α² × Dt × L²) - (α¹ × Dt × L¹) > | (β² × L²) - (β¹ × L¹) | ・・・（１）

8. Let α1 be the coefficient of linear expansion and β1 be the swelling elongation of the resin constituting the valve body. Let α2 be the coefficient of linear expansion and β2 be the swelling elongation of the resin constituting the case. Let L1 be the length of the portion of the valve body that expands or contracts in response to the temperature change of the fluid. When the length of the portion that expands or contracts in response to the temperature change of the fluid in the above case is L2, A control valve according to any one of claims 1 to 4, satisfying the following formula (2). (α² × L²) - (α¹ × L¹) > | (β² × L²) - (β¹ × L¹) | ・・・（２）

9. Let β1 be the swelling elongation rate of the resin constituting the valve body. Let β2 be the swelling elongation rate of the resin constituting the case. Let L1 be the length of the portion of the valve body that expands or contracts in response to the temperature change of the fluid. When the length of the portion that expands or contracts in response to the temperature change of the fluid in the above case is L2, A control valve according to any one of claims 1 to 4, satisfying the following formula (3). (β2 × L2) - (β1 × L1) = 0 ... (3)

10. When the temperature of the fluid is at the lower limit of the operating temperature range, the valve portion is in contact with the seat. The control valve according to any one of claims 1 to 4, wherein the force with which the valve portion is pressed against the seat is less than or equal to the lowest allowable stress among the allowable stresses of the materials constituting the case and the valve body.

11. A control valve according to any one of claims 1 to 4, wherein the coefficient of linear expansion of the resin constituting the valve body and the coefficient of linear expansion of the resin constituting the case are different.

12. A flow hole is provided on the outer surface of the case body. The control valve according to claim 1, wherein the flow hole is connected to the inner space of the case body.

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