Flow rate regulating valve

Abstract

A flow rate regulating valve 10 comprises: an integrally formed valve body 20; a needle 21 that moves in a first direction; a supporting member 22 that is screw connected to the needle 21; a sealing member 24 that is disposed in a valve chamber 33 and that is formed integrally; and a first resilient member 23 that is disposed between the supporting member 22 and the sealing member 24 in the first direction. The needle 21 has a tapered portion 211 that approaches or moves away from a valve seat 335 to change an opening degree of a flow passage 34. The sealing member 24 is formed integrally. The sealing member 24 is disposed in contact with a second accommodating chamber 332 formed in a tapered shape within the valve chamber 33. The first resilient member 23 urges the sealing member 24 in a direction approaching a connecting portion 330, and urges the supporting member 22, screw connected to the valve body 20, in a direction moving away from the connecting portion 330. The sealing member 24 holds the tapered portion 211 concentric with the valve chamber 33 by means of the urging force of the first elastic member 23.

Description

Flow Control Valve

[0001] The present invention relates to a flow rate adjusting valve.

[0002] Conventionally, flow control valves that control the flow rate and flow rate of a fluid by changing the valve opening between a tapered portion of a needle and a valve seat have been known. Patent Document 1 discloses a control valve having a bonnet fixed to a valve body with bolts, a packing nut, a spring, two packing assemblies, and a valve stem. The valve stem is inserted into a hole formed in the bonnet, packing nut, spring, and packing assembly, and is seatable on a valve seat formed in the valve body. In this control valve, the passage of a fluid is controlled according to the position of the valve stem from the valve seat.

[0003] Special Publication No. 2001-503835

[0004] In the control valve of Patent Document 1, when the packing nut is screwed onto the bonnet, a load is applied to the spring, which in turn applies a load to the packing assembly. The loaded packing assembly seals between the outer circumferential surface of the valve stem and the packing hole in the bonnet and is able to guide the valve stem.

[0005] However, it is desirable to further reduce misalignment between the valve seat and the valve stem to control the fluid more precisely.

[0006] A flow control valve according to one embodiment includes an integrally formed valve body including a flow path connecting a fluid inlet and an outlet, a valve chamber extending along a first direction, and a valve seat provided in the flow path; a needle disposed in the valve chamber and moving along the first direction; a support member disposed in the valve chamber and threadedly coupled to the needle; a seal member disposed in the valve chamber; and an elastic member disposed between the support member and the seal member in the first direction. The needle has a rod portion extending along the first direction and a tapered portion connected to the rod portion, which changes the opening degree of the flow path by approaching or moving away from the valve seat as the needle moves along the first direction. The seal member is integrally formed. The seal member is disposed in contact with a tapered region of the valve chamber, which is tapered such that the diameter of the inner circumferential surface of the valve chamber decreases toward the connection portion with the flow path. The support member, the seal member, and the elastic member each have a through hole through which the rod portion is inserted. The outer peripheral surface of the support member is threadedly coupled to the inner peripheral surface of the opening of the valve chamber so as to be movable along the first direction relative to the valve body. The elastic member urges the seal member in a direction toward the connecting portion along the first direction and urges the support member in a direction away from the connecting portion along the first direction. The urging force of the elastic member keeps the tapered portion of the seal member concentric with the valve chamber.

[0007] According to the present invention, it is possible to suppress the occurrence of misalignment between the valve seat and the tapered portion of the needle, thereby improving the accuracy of fluid control and maintaining this accuracy for a long period of time.

[0008] It is an appearance diagram of the flow rate adjustment valve of the embodiment. It is a cross-sectional view of the flow rate adjustment valve. It is a cross-sectional view of the flow rate adjustment valve. It is a cross-sectional view of the flow rate adjustment valve of a modified example.

[0009] A flow control valve according to an embodiment of the present invention will be described in detail below with reference to the drawings. The flow control valve according to the present embodiment is provided in, for example, a device for adjusting the flow rate of an electrolyte injected into a battery container in a secondary battery manufacturing process, or a device for adjusting the flow rate of a chemical solution used as a cleaning solution in a semiconductor manufacturing process.

[0010] <Flow Control Valve> Fig. 1 is an external view of a flow control valve 10. Figs. 2 and 3 are cross-sectional views of the flow control valve 10 taken along line A-A in Fig. 1. The flow control valve 10 comprises a valve body 20, a needle 21, a support member 22, a first elastic member 23, a seal member 24, an intermediate member 25, and an operating portion 26. Note that Figs. 2 and 3 show cross sections of the flow control valve 10 in different valve opening states.

[0011] <Valve body 20> The valve body 20 is integrally formed in a rectangular columnar shape using, for example, a metal material such as stainless steel or a resin material such as CTFE (fluororesin). A suitable material is used for the valve body 20 depending on the characteristics of the fluid to be regulated by the flow control valve 10. For example, if the flow control valve 10 is used in a secondary battery manufacturing process, a metal material is used for the valve body 20, and if it is used in a semiconductor manufacturing process, a resin material is used for the valve body 20. Furthermore, the external shape of the valve body 20 is not limited to a rectangular columnar shape.

[0012] In the following description, the direction along the long side of the valve body 20 shown in Figure 1 is referred to as the X direction, and the direction perpendicular to the X direction and along the short side of the valve body 20 is referred to as the Y direction. The direction perpendicular to the X and Y directions is referred to as the Z direction (see Figures 2 and 3). In addition, the base side of the arrows indicating the X, Y, and Z directions shown in each figure may be referred to as the - side, and the tip side as the + side.

[0013] The valve body 20 is formed with a first port 31, a second port 32, a valve chamber 33, and a flow path 34. The first port 31 and the second port 32 are openings formed in the valve body 20, and fluid flows into the interior of the valve body 20 and out of the valve body 20 through the first port 31 and the second port 32.

[0014] As shown in FIGS. 2 and 3 , the first port 31 is formed on the negative side in the X direction relative to the valve chamber 33, and the second port 32 is formed on the positive side in the X direction relative to the valve chamber 33. The first port 31 is formed on the positive side in the Z direction relative to the second port 32. The first port 31 is an outlet through which the fluid flows out, and the second port 32 is an inlet through which the fluid flows in. A flow path 34 connects the first port 31 and the second port 32. The fluid that flows in from the second port 32 passes through the flow path 34 and flows out of the valve body 20 from the first port 31. The positional relationship between the first port 31, the second port 32, and the valve chamber 33 is not limited to the positional relationship shown in FIGS. 2 and 3 . Alternatively, the first port 31 may be an inlet, and the second port 32 may be an outlet.

[0015] The valve chamber 33 is formed inside the valve body 20, extends along the Z direction which is the first direction, and opens to the outside of the valve body 20 at the end of the valve chamber 33 on the positive side in the Z direction. The end of the valve chamber 33 on the negative side in the Z direction is a connection part 330 which connects to the flow path 34.

[0016] The valve chamber 33 accommodates the needle 21, the support member 22, the first elastic member 23, the seal member 24, and the intermediate member 25. A first accommodation chamber 331 and a second accommodation chamber 332 are formed in the valve chamber 33. The first accommodation chamber 331 is formed on the positive side in the Z direction of the valve chamber 33, and accommodates the support member 22, the first elastic member 23, and the intermediate member 25. The end of the first accommodation chamber 331 on the positive side in the Z direction opens to the outside of the valve body 20, and a female thread portion 334 is formed on an inner peripheral surface 331a of the opening.

[0017] The second storage chamber 332 is formed near the connection portion 330, which is the negative end of the valve chamber 33 in the Z direction. That is, the second storage chamber 332 is formed between the first storage chamber 331 and the flow path 34 in the Z direction, and is connected to the first storage chamber 331 at the positive end of the second storage chamber 332 in the Z direction, and is connected to the flow path 34 at the negative end of the second storage chamber 332 in the Z direction. The inner circumferential surface 333 of the second storage chamber 332 is formed in a tapered shape whose inner diameter decreases toward the negative side in the Z direction. The seal member 24 is accommodated in this second storage chamber 332. That is, the second storage chamber 332 is a tapered region in which the diameter of the inner circumferential surface 333 decreases as it approaches the connection portion 330, and the seal member 24 is disposed in this tapered region.

[0018] A portion of the flow path 34 extends along the Z direction, and forms a third storage chamber 340 that stores a portion of the needle 21, which will be described later. A valve seat 335 is provided in the third storage chamber 340. The inner diameter of the third storage chamber 340 on the positive side in the Z direction from the valve seat 335 is larger than the inner diameter on the negative side in the Z direction from the valve seat 335.

[0019] The valve chamber 33 and the third storage chamber 340 are formed concentrically about an axis AX along the Z direction. Compared to a structure in which the valve chamber 33 and the valve seat 335 provided in the third storage chamber 340 are separate components and are combined together, the integrally formed valve body 20 reduces misalignment between the axis of the valve chamber 33 and the axis of the third storage chamber 340 in which the valve seat 335 is provided.

[0020] <Needle 21> The needle 21 is made of a metal material such as stainless steel or a resin material. As with the valve body 20, a suitable material is used for the needle 21 depending on the characteristics of the fluid to be adjusted by the flow rate control valve 10. The needle 21 has a rod portion 210 and a tapered portion 211. The rod portion 210 has a cylindrical shape centered on a central axis CX. The tapered portion 211 is connected to the end of the rod portion 210 on the negative side in the Z direction. The tapered portion 211 is formed in a tapered shape centered on the central axis CX and having a diameter that decreases toward the negative side in the Z direction. The needle 21 is disposed so that the central axis CX substantially coincides with the axis AX. In other words, the rod portion 210 and the tapered portion 211 of the needle 21 extend along the Z direction.

[0021] The needle 21 is disposed within the valve chamber 33 and the third housing chamber 340 so as to be movable along the Z direction. The movement of the needle 21 along the Z direction adjusts the flow rate and flow velocity of the fluid flowing through the flow path 34. Specifically, a male thread portion 212 is formed on the outer circumferential surface of the rod portion 210 of the needle 21 near the end on the positive side in the Z direction, and is engaged with a female thread portion 222 of the support member 22. In other words, the rod portion 210 of the needle 21 is threadedly coupled to the support member 22 at a position farther away from the connection portion 330 than the seal member 24.

[0022] The operating unit 26 is fixed to the positive end of the rod 210 in the Z direction by an attachment member 261 such as a setscrew or pin. When the operating unit 26 is rotated by an operator, the needle 21 rotates about the central axis CX. Because the rod 210 is threadedly coupled to the support member 22, when the operating unit 26 is rotated in response to operation, the needle 21 moves along the Z direction relative to the support member 22. In this case, the needle 21 moves to the positive side in the Z direction or the negative side in the Z direction depending on the direction in which the operating unit 26 is rotated.

[0023] The tapered portion 211 approaches or moves away from the valve seat 335 in accordance with movement of the needle 21 in the Z direction. Specifically, when the needle 21 moves in the +Z direction, the tapered portion 211 moves in a direction away from the valve seat 335. When the needle 21 moves in the -Z direction, the tapered portion 211 moves in a direction approaching the valve seat 335. As a result of the needle 21 approaching, the tapered portion 211 may abut against the valve seat 335, or may reach a position close to the valve seat 335 without abutting against the valve seat 335. FIG. 2 is a cross-sectional view of the flow rate adjustment valve 10 when the tapered portion 211 is in contact with or in a position close to the valve seat 335, and FIG. 3 is a cross-sectional view of the flow rate adjustment valve 10 when the tapered portion 211 is away from the valve seat 335.

[0024] <Support member 22> The support member 22 is made of a metal material such as stainless steel, and is disposed within the valve chamber 33. The support member 22 is a cylindrical member such as a nut. A first through hole 221 is formed in the support member 22, penetrating the support member 22 from the inside to the outside along the Z direction. The support member 22 is attached to the valve body 20 so that the central axis of the first through hole 221 substantially coincides with the axis AX.

[0025] The inner circumferential surface of the first through hole 221 has a first inner circumferential surface 221a on which a female thread portion 222 is formed, and a second inner circumferential surface 221b on which no thread portion is formed. The female thread portion 222 meshes with a male thread portion 212 formed on the rod portion 210 of the needle 21. As a result, the support member 22 supports the needle 21 so that it can move in the Z direction relative to the support member 22. Meanwhile, a small gap is provided between the second inner circumferential surface 221b on which no thread portion is formed and the outer circumferential surface of the rod portion 210.

[0026] A male thread portion 223 is formed on the outer peripheral surface of the support member 22. The male thread portion 223 meshes with a female thread portion 334 formed on the inner peripheral surface of the first storage chamber 331 of the valve chamber 33 near the end on the +Z direction side. In other words, the support member 22 is threadedly coupled to the valve body 20 at a position farther away from the connection portion 330 than the seal member 24, which will be described later, is. In this way, the support member 22 is attached to the valve body 20 so as to be movable in the Z direction relative to the valve body 20.

[0027] <First Elastic Member 23> The first elastic member 23 is, for example, a disc spring, a wave washer, a coil spring, or the like, and is accommodated in the first accommodation chamber 331 of the valve chamber 33. The first elastic member 23 is disposed on the negative side in the Z direction relative to the support member 22. That is, the positive side in the Z direction of the first elastic member 23 is in contact with the negative side in the Z direction of the support member 22. The first elastic member 23 biases the support member 22, which is disposed on the positive side in the Z direction relative to the first elastic member 23, toward the positive side in the Z direction, i.e., in a direction away from the connection portion 330. This suppresses backlash-induced rattles that occur between the female thread portion 334 of the valve body 20 and the male thread portion 223 of the support member 22. As a result, the position of the needle 21 in the Z direction is determined.

[0028] Furthermore, the negative side in the Z direction of the first elastic member 23 is in contact with the positive side in the Z direction of the intermediate member 25. The first elastic member 23 biases the intermediate member 25 and the seal member 24, which are arranged on the negative side in the Z direction relative to the first elastic member 23, in a direction approaching the connecting portion 330 on the negative side in the Z direction.

[0029] When the support member 22 moves toward the negative side in the Z direction and is tightened into the valve body 20, the deformation amount of the first elastic member 23 disposed between the support member 22 and the intermediate member 25 increases. As a result, the biasing force of the first elastic member 23 acting on the seal member 24 and the support member 22 increases.

[0030] A second through-hole 231 that penetrates inward and outward along the Z direction is formed in the first elastic member 23. The first elastic member 23 is arranged so that the central axis of the second through-hole 231 substantially coincides with the axis AX. The rod portion 210 of the needle 21 is inserted into the second through-hole 231.

[0031] <Intermediate member 25> The intermediate member 25 is made of a metal material such as stainless steel, and is a disk-shaped member such as a washer. The intermediate member 25 is housed in the first housing chamber 331 of the valve chamber 33. Specifically, the intermediate member 25 is disposed on the negative side in the Z direction with respect to the first elastic member 23. In other words, the positive side in the Z direction of the intermediate member 25 is in contact with the negative side in the Z direction of the first elastic member 23. Therefore, the intermediate member 25 is biased toward the negative side in the Z direction by the first elastic member 23.

[0032] An annular protrusion 252 is formed on the positive side of the intermediate member 25 in the Z direction, passing through the second through-hole 231 of the first elastic member 23 and protruding toward the support member 22. When the protrusion 252 abuts against the surface of the support member 22 on the negative side in the Z direction, the protrusion 252 serves as both a stopper and a guide between the support member 22 and the intermediate member 25. The protrusion 252 as a stopper prevents the first elastic member 23 from being crushed more than necessary and exceeding the allowable stress. The protrusion 252 as a guide prevents the central axis of the first elastic member 23 from deviating from the axis AX.

[0033] A third through hole 251 penetrating inward and outward along the Z direction is formed in the intermediate member 25. The intermediate member 25 is arranged so that the central axis of the third through hole 251 substantially coincides with the axis AX. The rod portion 210 of the needle 21 is inserted into the third through hole 251.

[0034] <Sealing member 24> The sealing member 24 is integrally formed using a resin material such as PTFE (fluororesin) that is softer (less rigid) than the valve body 20, the needle 21, and the intermediate member 25. The sealing member 24 has a tapered shape that conforms to the second accommodation chamber 332, and is accommodated in the second accommodation chamber 332 of the valve chamber 33, as described above. That is, as described above, the valve body 20 and the support member 22 are threadedly coupled to each other at a position farther away from the connection portion 330 than the sealing member 24, and the support member 22 and the needle 21 are threadedly coupled to each other at a position farther away from the connection portion 330 than the sealing member 24.

[0035] The seal member 24 disposed in the second storage chamber 332 is located on the negative side in the Z direction relative to the intermediate member 25. In other words, the first elastic member 23 disposed on the positive side in the Z direction relative to the intermediate member 25 is disposed between the support member 22 and the seal member 24 in the Z direction. The surface of the seal member 24 on the positive side in the Z direction is in contact with the surface of the intermediate member 25 on the negative side in the Z direction.

[0036] Because the intermediate member 25 is biased toward the negative side in the Z direction by the first elastic member 23, the seal member 24 is biased via the intermediate member 25 in a direction from the first elastic member 23 to approach the connection portion 330 on the negative side in the Z direction. In other words, the intermediate member 25 functions as a transmission portion that transmits the biasing force of the first elastic member 23 to the seal member 24. Because the intermediate member 25 is a disk-shaped member as described above, the biasing force received from the first elastic member 23 is uniformly transmitted by the intermediate member 25 to the surface of the seal member 24 on the positive side in the Z direction. In addition, the surface 242 on the negative side in the Z direction of the seal member 24 is tapered and comes into contact with the tapered inner circumferential surface 333 of the second storage chamber 332 of the valve chamber 33.

[0037] The seal member 24 has a fourth through hole 241 that penetrates inward and outward along the Z direction. The seal member 24 is arranged so that the central axis of the fourth through hole 241 substantially coincides with the axis AX. In particular, because the seal member 24 is accommodated in the tapered second accommodation chamber 332, it is easy to arrange the seal member 24 so that the central axis of the fourth through hole 241 substantially coincides with the axis AX. The rod portion 210 of the needle 21 is inserted into the fourth through hole 241.

[0038] The seal member 24 is biased toward the negative side in the Z direction by the first elastic member 23 via the intermediate member 25. As described above, the seal member 24 has lower rigidity than the intermediate member 25 and the valve body 20. Therefore, internal stress is generated in the seal member 24 that is subjected to the biasing force, and the surface 242 comes into close contact with the inner circumferential surface 333 of the second storage chamber 332 of the valve chamber 33. The generation of stress in the seal member 24 as described above prevents a gap from being generated between the second storage chamber 332 of the valve chamber 33 and the flow path 34. In other words, the sealing performance of the seal member 24 can be improved.

[0039] Furthermore, when the seal member 24 is subjected to the biasing force, the inner diameter of the fourth through hole 241 becomes smaller. Therefore, the inner circumferential surface of the fourth through hole 241 and the outer circumferential surface of the rod portion 210 of the needle 21 come into close contact with each other. In particular, the seal member 24 receives a reaction force from the inner circumferential surface 333 due to the biasing force acting from the +Z direction side. Because the inner circumferential surface 333 is tapered, the reaction force received by the seal member 24 includes a component in a direction intersecting the Z direction. Therefore, compared to when the inner circumferential surface 333 is not tapered, the force acting in a direction toward the axis AX increases, contributing to radial deformation of the fourth through hole 241. As a result, the inner circumferential surface of the fourth through hole 241 and the outer circumferential surface of the rod portion 210 of the needle 21 come into closer contact with each other.

[0040] As described above, the outer peripheral surface of the rod portion 210 of the needle 21 is in close contact with the fourth through-hole 241 of the seal member 24, thereby maintaining the central axis CX of the needle 21 substantially aligned with the axis AX. That is, misalignment of the needle 21 is suppressed. This prevents the tapered portion 211 of the needle 21 from approaching the valve seat 335 in an inclined state. That is, the seal member 24 maintains the tapered portion 211 of the needle 21 concentric with the valve chamber 33.

[0041] 2 shows a state in which the tapered portion 211 of the needle 21 is in contact with or in the vicinity of the valve seat 335. At this time, the tapered portion 211 causes the valve seat 335 to have a valve opening of zero, and the flow path 34 is blocked.

[0042] In this state, when the operator rotates the operating unit 26 to move the needle 21 toward the + side in the Z direction, the tapered portion 211 moves away from the valve seat 335, as shown in Fig. 3. As a result, the first port 31 and the second port 32 are connected to each other, allowing fluid to pass through the flow path 34. The amount of separation of the tapered portion 211 from the valve seat 335 changes depending on the amount of movement of the needle 21 toward the + side in the Z direction, and therefore the valve opening, which is the difference between the diameter of the tapered portion 211 and the inner diameter of the valve seat 335, changes.

[0043] The flow velocity and flow rate of the fluid passing through the flow path 34 change depending on the degree of valve opening. In this way, when the operator operates the operating unit 26, the tapered portion 211 moves closer to or away from the valve seat 335 as the needle 21 moves along the Z direction, changing the valve opening. As a result, the flow velocity and flow rate of the fluid flowing through the flow path 34 are adjusted, or the flow path 34 is blocked.

[0044] In this way, even when the needle 21 moves along the Z direction, the sealing member 24 is biased toward the negative Z direction by the first elastic member 23, so it is possible to maintain sealing between the valve chamber 33 and the flow path 34. Furthermore, since misalignment of the needle 21 is suppressed, the valve opening degree is precisely controlled in accordance with the amount of operation of the operating unit 26.

[0045] Furthermore, the support member 22 is threadedly coupled to the valve body 20. As described above, the first elastic member 23 biases the support member 22, which is disposed on the +Z direction side relative to the first elastic member 23, toward the +Z direction side. This prevents backlash caused by the threaded coupling from occurring between the valve body 20 and the support member 22. As a result, fluctuations in the position of the needle 21 in the Z direction are suppressed, and the needle 21 is positioned in the Z direction, enabling minute adjustment of the flow rate of the fluid flowing through the flow path 34.

[0046] Additionally, creep, in which the seal member 24 is distorted, may occur over time. In such a case, by further tightening the support member 22 toward the negative side in the Z direction, the sealing performance of the seal member 24 and the function of suppressing misalignment of the needle 21 can be maintained. Furthermore, by further tightening the support member 22 toward the negative side in the Z direction, the protrusion 252 of the intermediate member 25 comes into contact with the surface of the support member 22 on the negative side in the Z direction, and the protrusion 252 can maintain its role as a stopper and guide.

[0047] When the support member 22 moves toward the negative side in the Z direction, the biasing force toward the negative side in the Z direction acting on the seal member 24 from the first elastic member 23 via the intermediate member 25 increases. This brings the surface 242 of the seal member 24 into close contact with the inner circumferential surface 333 of the second storage chamber 332 of the valve chamber 33, and brings the inner circumferential surface of the fourth through hole 241 of the seal member 24 into close contact with the outer circumferential surface of the rod portion 210 of the needle 21. In other words, even if creep occurs in the seal member 24, the seal between the valve chamber 33 and the flow path 34 is maintained, misalignment of the needle 21 is suppressed, and the flow rate and flow velocity are accurately controlled by the needle 21.

[0048] According to the above-described embodiment, at least one of the following advantageous effects can be obtained.

[0049] (1) The flow rate control valve 10 comprises a valve body 20, a needle 21, a support member 22, a first elastic member 23, and a seal member 24. The valve body 20 is provided with a flow path 34 and a valve chamber 33 extending along the first direction, the Z direction, and is integrally formed with the valve body 20. The support member 22 is disposed in the valve chamber 33 and is threadedly coupled to the needle 21. The seal member 24 is disposed in the valve chamber 33 and is integrally formed with the valve chamber 33. The first elastic member 23 biases the seal member 24 toward the negative Z direction, which is a direction approaching a connection portion 330 between the flow path 34 and the valve chamber 33 along the Z direction. The seal member 24 biased by the first elastic member 23 holds the tapered portion 211 of the needle 21 concentric with the valve chamber 33. This prevents a gap from being generated between the valve chamber 33 and the flow path 34, improving the sealing performance of the seal member 24, and maintaining a state in which the central axis CX of the needle 21 is substantially aligned with the axis AX. This prevents misalignment of the needle 21, and prevents the tapered portion 211 from approaching the valve seat 335 in an inclined state. As a result, the valve opening degree according to the operating state of the operating portion 26 can be obtained, allowing the needle 21 to accurately control the flow rate and flow velocity.

[0050] Furthermore, the valve body 20 is integrally formed. Therefore, compared to a structure in which the valve chamber 33 and the valve seat 335 provided in the third storage chamber 340 are separate components and then assembled together, this embodiment reduces misalignment between the axis of the valve chamber 33 and the axis of the third storage chamber 340 in which the valve seat 335 is provided. In other words, the valve chamber 33 and the third storage chamber 340 are formed with the axis AX concentric.

[0051] Furthermore, the seal member 24 is integrally formed. If the seal member were formed using multiple members, it would be necessary to align the through holes formed in each member so that the centers of the respective through holes approximately coincide with the axis AX. In contrast, in this embodiment, since the seal member 24 is integrally formed, it is only necessary to approximately align the center of one fourth through hole 241 with the axis AX. This simplifies the manufacture of the seal member 24 and the placement of the seal member 24 in the second housing chamber 332, while improving the accuracy of aligning the fourth through hole 241.

[0052] The valve chamber 33 also includes a second accommodating chamber 332, which is a tapered region whose inner circumferential surface 333 has a diameter that decreases toward the connecting portion 330. The seal member 24 has a tapered shape that conforms to the second accommodating chamber 332 and is disposed in contact with the second accommodating chamber 332. This facilitates disposing the seal member 24 so that the central axis of the fourth through hole 241 is substantially aligned with the axis AX. Furthermore, because the inner circumferential surface 333 is tapered, the reaction force that the seal member 24 receives from the inner circumferential surface 333 due to the biasing force acting from the +Z direction side includes a component in a direction intersecting the Z direction. This increases the force acting in the direction toward the axis AX, resulting in closer contact between the inner circumferential surface of the fourth through hole 241 and the outer circumferential surface of the rod portion 210 of the needle 21. As a result, misalignment of the tapered portion 211 with respect to the valve seat 335 is suppressed, enabling accurate control of the valve opening according to the amount of operation of the operating portion 26.

[0053] (2) The flow rate adjustment valve 10 includes an intermediate member 25 that is disposed between the seal member 24 and the first elastic member 23 in the Z direction and has higher rigidity than the seal member 24. The seal member 24 is biased by the first elastic member 23 via the intermediate member 25. The intermediate member 25 is formed of a material that is more rigid than the seal member 24. As a result, the biasing force of the first elastic member 23 acts uniformly on the + side of the seal member 24 in the Z direction via the intermediate member 25. As a result, the entire surface 242 of the seal member 24 is in close contact with the inner circumferential surface 333 of the second housing chamber 332, and the entire inner circumferential surface of the fourth through hole 241 of the seal member 24 is in close contact with the outer circumferential surface of the rod portion 210. This improves the sealing performance of the seal member 24 and makes it possible to suppress misalignment of the needle 21.

[0054] (3) The support member 22 and the valve body 20 are threadedly coupled at a position farther away from the connection portion 330 than the seal member 24. The support member 22 and the rod portion 210 of the needle 21 are threadedly coupled at a position farther away from the connection portion 330 than the seal member 24. When the support member 22 is fastened to the valve body 20, or when the needle 21 moves in response to the rotation of the operating portion 26, there is a risk that foreign matter may enter the valve chamber 33 through the threaded coupling portion. Even in such a case, the seal member 24 prevents foreign matter from entering the flow path 34 from the valve chamber 33.

[0055] <Modification> Figure 4 is a cross-sectional view of a flow rate adjustment valve 10 in a modification. In the modification, the same reference numerals as in the embodiment are used for configurations that are similar or substantially similar to those in the embodiment. Below, differences from the embodiment will be mainly explained. Points that are not particularly explained are the same as in the embodiment. Note that Figure 4 is a cross-sectional view taken along line A-A in Figure 1, and shows a state in which the tapered portion 211 is separated from the valve seat 335.

[0056] The flow rate adjustment valve 10 of the modified example includes a second elastic member 27 that biases the operating part 26 toward the + side in the Z direction. The second elastic member 27 is, for example, a coil spring or the like, and is disposed between the surface on the - side in the Z direction of the operating part 26, which is fixed to the + side end in the Z direction of the rod part 210 of the needle 21, and the support member 22. Specifically, the + side end in the Z direction of the second elastic member 27 abuts against the surface on the - side in the Z direction of the operating part 26.

[0057] The support member 22 is formed with an accommodation groove 224 that accommodates a portion of the second elastic member 27, specifically the vicinity of the end portion on the negative side in the Z direction. The accommodation groove 224 is formed in the first through-hole 221, in an upper portion of the first inner circumferential surface 221a on which the female thread portion 222 is formed. The inner diameter of the accommodation groove 224 is larger than the inner diameter of the first inner circumferential surface 221a. Therefore, a step 224a is formed at the connection portion between the accommodation groove 224 and the first inner circumferential surface 221a. This step 224a abuts against the end portion on the negative side in the Z direction of the second elastic member 27.

[0058] As described above, the second elastic member 27 abuts at its end on the positive side (one side) in the Z direction against the surface on the negative side in the Z direction of the operating unit 26, and at its end on the negative side (the other side) against the step 224a that is the lower end surface of the accommodation groove 224 of the support member 22. As a result, the second elastic member 27 is disposed between the operating unit 26 and the support member 22. Because the second elastic member 27 is a coil spring, it can also be said that the second elastic member 27 is disposed on the outer periphery of the rod portion 210 near the upper end of the rod portion 210.

[0059] The needle 21 and the support member 22 are threadedly coupled together by engaging the male thread portion 212 formed on the rod portion 210 of the needle 21 with the female thread portion 222 formed on the support member 22. The second elastic member 27 biases the operating unit 26, which is disposed on the positive side in the Z direction relative to the second elastic member 27, toward the positive side in the Z direction. That is, the second elastic member 27 biases the operating unit 26 in a direction away from the support member 22 along the Z direction, which is the first direction. This prevents backlash caused by the threaded coupling from occurring between the needle 21 and the support member 22. As a result, fluctuations in the position of the needle 21 in the Z direction are suppressed, and the needle 21 is positioned in the Z direction, making it possible to stabilize the flow rate of the fluid flowing through the flow path 34.

[0060] In the above-described modified example, in addition to the effects (1) to (3) obtained by the embodiment, the following effects can be obtained.

[0061] (4) The flow rate adjustment valve 10 includes a second elastic member 27 that is provided between the support member 22 and the operating unit 26 connected to the needle 21 and biases the operating unit 26 in a direction away from the support member 22 along the first direction, i.e., the Z direction. This suppresses backlash caused by the threaded connection between the needle 21 and the support member 22, thereby suppressing positional fluctuation of the needle 21 in the Z direction. As a result, the needle 21 is positioned in the Z direction, thereby stabilizing the flow rate of the fluid flowing through the flow path 34.

[0062] Although various embodiments and modifications have been described above, the present invention is not limited to these. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention.

[0063] The flow rate adjustment valve 10 does not necessarily have to include the intermediate member 25. In this case, the seal member 24 may be integrally molded using materials with different rigidities on the positive Z-direction side and the negative Z-direction side. Specifically, the negative Z-direction side of the seal member 24 may be formed from a resin material such as PTFE (fluororesin), and the surface of the first elastic member 23 facing the negative Z-direction side surface (the positive Z-direction side surface) may be formed from a material with high rigidity similar to that of the intermediate member 25. This allows the biasing force from the first elastic member 23 to be transmitted even when the intermediate member 25 is not disposed in the valve chamber 33, thereby reducing the number of parts.

[0064] 10 Flow rate control valve, 20 Valve body, 21 Needle, 22 Support member, 23 First elastic member, 24 Sealing member, 25 Intermediate member, 26 Operating portion, 27 Second elastic member, 31 First port, 32 Second port, 33 Valve chamber, 34 Flow path, 210 Rod portion, 211 Tapered portion, 212 Male thread portion, 221 First through hole, 221a First inner peripheral surface, 222 Female thread portion, 223 Male thread portion, 231 Second through hole, 241 Fourth through hole, 242 Surface, 251 Third through hole, 252 Protrusion portion, 330 Connection portion, 331 First storage chamber, 331a Opening inner peripheral surface, 332 Second storage chamber, 333 Inner peripheral surface, 334 Female thread portion, 335 Valve seat, 340 Third storage chamber

Claims

a valve body including a flow path communicating an inlet and an outlet of a fluid, a valve chamber extending along a first direction, and a valve seat provided in the flow path, the valve body being integrally formed with the valve body; a needle disposed in the valve chamber and moving along the first direction; a support member disposed in the valve chamber and screw-coupled to the needle; a seal member disposed in the valve chamber; and a first elastic member disposed between the support member and the seal member in the first direction, the needle having a rod portion extending along the first direction and a tapered portion connected to the rod portion, the tapered portion moving toward or away from the valve seat as the needle moves along the first direction to change the opening of the flow path, the seal member being integrally formed, and the seal member being disposed in contact with a tapered region of the valve chamber, the diameter of an inner circumferential surface of the valve chamber decreasing toward a connection portion with the flow path, and a through hole into which the rod portion is inserted is formed in the support member, the seal member, and the first elastic member, a first elastic member biasing the sealing member in a direction toward the connection portion along the first direction and biasing the support member in a direction away from the connection portion along the first direction; and a second elastic member biasing the sealing member in a direction toward the connection portion along the first direction, the second elastic member biasing the sealing member in a direction toward the connection portion along the first direction, the third elastic member biasing the sealing member so that the tapered portion is concentric with the valve chamber.

2. A flow control valve as claimed in claim 1, further comprising an intermediate member disposed between said sealing member and said first elastic member in said first direction and having a higher rigidity than said sealing member, said sealing member being biased by said first elastic member via said intermediate member.

3. A flow control valve as described in claim 2, further comprising an operating section which is operated to move the needle along the first direction, the rod section being threadedly connected to the inner circumferential surface of the through hole of the support member, and the rod section moving along the first direction relative to the support member in response to operation of the operating section.

4. A flow control valve as described in claim 3, wherein the support member and the valve body are screwed together at a position farther away from the connection portion than the seal member, and the support member and the rod portion are screwed together at a position farther away from the connection portion than the seal member.

5. A flow control valve as claimed in claim 2, wherein the intermediate member is provided with a protrusion which passes through the through hole of the first elastic member and protrudes towards the support member.

6. A flow control valve as claimed in claim 4, further comprising a second elastic member provided between the support member and the operating part connected to the needle, for biasing the operating part in a direction away from the support member along the first direction.

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