Needle valve

Abstract

To provide a needle valve which is easy to assemble, has an excellent alignment function, and is highly reliable. The needle valve 10 comprises a stem 12, a connecting member 14 having a neck 14A that fits tightly against the tip of the stem 12 and a head 14B supported at the tip of the neck 14A, a valve body 16 connected to the stem 12 via the connecting member 14, and a fixing member 18. The valve body 16 has a valve body main portion 20 and a covering portion 22 that is attached to the valve body main portion 20 so as to cover the head 14B of the connecting member 14. A lateral gap perpendicular to the axial direction is provided between the valve body 16 and the connecting member 14, and the valve body 16 is movable laterally relative to the stem 12 and the connecting member 14. Lateral holes 12A and 14C extending laterally are formed at the fitting portion between the stem 12 and the neck 14A of the connecting member 14. The fixing member 18 is inserted into the lateral hole 12A of the stem 12 and the lateral hole 14C of the connecting member 14 to fix the connecting member 14 to the stem 12.

Description

Technical Field

[0001] The present invention relates to a needle valve used for flow rate adjustment and the like.

Background Art

[0002] Conventionally, needle valves have been used in various devices and equipment for flow rate adjustment and the like. The needle valve includes a stem in the shape of a rod and a valve body attached to the tip of the stem. The side surface of the valve body is a conical surface or a spherical surface whose diameter decreases toward the tip. The valve opens and closes when the stem moves forward and backward along the axial direction and the valve body separates from or abuts against an annular valve seat. Also, the flow rate is adjusted by adjusting the gap between the valve body and the valve seat. When the axis of the stem and the axis of the valve seat are misaligned, even when the valve body abuts against the valve seat, a gap is partially generated. Therefore, in order to reliably close the valve, it is preferable that the axis of the stem and the axis of the valve seat coincide with each other with high precision. For example, by forming a guide for guiding the stem to be movable forward and backward along the axial direction and the valve seat in a common valve body with high precision, the axes of both can be made to coincide with each other with high precision. Also, the bonnet in which the guide of the stem is formed and the valve body in which the valve seat is formed are separately manufactured, and by assembling both with high precision, the axes of both can be made to coincide with each other with high precision. On the other hand, in either case, high-precision machining is required. For this reason, there is a problem that the manufacturing cost of the needle valve increases.

[0003] In contrast, needle valves are known in which the valve body is mounted so as to be movable with respect to the stem and has a self-aligning function that adjusts the axis of the valve body to coincide with the axis of the valve seat. For example, Patent Document 1 discloses a high-temperature valve comprising a valve stem having a flange-shaped valve body support portion at its lower part, a valve body composed of a valve body main member having a support space formed to accommodate the lower part of the valve stem, and a valve body engaging member through which the valve stem is inserted and screwed into the valve body main member, wherein the valve body is attached to the valve stem by sandwiching the valve body support portion of the valve stem from above and below with the valve body main member and the valve body engaging member. A gap is formed between the valve body support portion of the valve stem and the valve body, and if the axis of the valve stem is misaligned with the axis of the valve seat, the valve body tilts with respect to the valve stem while contacting the valve seat, and is adjusted so that the valve body is in close contact with the valve seat.

[0004] Patent Document 2 discloses a cryogenic globe valve in which a resin valve body having a tapered conical surface is attached to the lower end of a long stem in such a way that it can move three-dimensionally relative to the stem even under cryogenic conditions. Specifically, an insertion part (hole) is formed in either the stem or the valve body, and a mounting part is formed in the other that is inserted into the insertion part. Through holes are formed in the insertion part and the mounting part in a direction intersecting the longitudinal direction of the stem, and a fixing member is inserted through the through hole, with a gap provided between the fixing member and the through hole. When the resin valve body shrinks due to heat, a gap is formed between the insertion part and the mounting part, and a movable clearance is maintained for the resin valve body with respect to the gap between the fixing member and the through hole. If the axis of the stem is inclined with respect to the axis of the valve seat, the valve body inclins with respect to the stem while contacting the valve seat, and is adjusted so that the axis of the valve body coincides with the axis of the valve seat.

[0005] Furthermore, Patent Document 3 discloses a flow control valve comprising a stem, a valve body having a columnar portion connected to the stem and a contact portion with an inclined surface that contacts the valve seat, and a bolt whose threaded portion is screwed into the tip of the stem and whose head is housed in the columnar portion of the valve body, thereby connecting the valve body to the stem, wherein a predetermined gap is formed between the bolt and the columnar portion of the valve body in a lateral direction perpendicular to the axis. If the axis of the stem is laterally misaligned with respect to the axis of the valve seat, the contact portion of the valve body contacts the valve seat while the valve body moves laterally, adjusting so that the axis of the valve body coincides with the axis of the valve seat. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2005-321061 [Patent Document 2] International Publication No. 2020 / 091037 [Patent Document 3] Japanese Patent Publication No. 2022-006996 [Overview of the project] [Problems that the invention aims to solve]

[0007] In the high-pressure valve disclosed in Patent Document 1, the lower part of the valve body that contacts the valve seat is spherical, and the bottom surface within the support space is also spherical, so the self-aligning function is achieved only by the rotation of the valve body. In other words, lateral movement perpendicular to the axis of the valve body is not possible. For this reason, if the lower part of the valve body is a conical needle valve and the axis of the stem and the axis of the valve body are, for example, shifted laterally and parallel, the self-aligning function will not be achieved. Furthermore, the high-temperature valve disclosed in Patent Document 1 has a configuration in which the valve body support portion of the valve stem is sandwiched between the valve body main member and the valve body engaging member that constitute the valve body, which imposes constraints on the assembly work. For example, it is not possible to attach the valve body to the valve stem after attaching the valve stem to the bonnet; it is necessary to attach the valve body to the valve stem first and then attach the valve stem to the bonnet. Also, when removing the valve body from the valve stem, it is necessary to remove the valve stem from the bonnet. In addition, the attachment and detachment of the valve body engaging member and the valve body main member is not easy because it is performed with a long valve stem inserted through the valve body engaging member. Furthermore, in the structure disclosed in Patent Document 1, the diameter of the valve body must be larger than the diameter of the stem, which limits its application to small valves and valves in the low flow rate range.

[0008] The cryogenic globe valve disclosed in Patent Document 2 has a fixing member inserted through the through-hole between the stem and the valve body, and a gap is provided between the fixing member and the through-hole. Under cryogenic conditions, a gap is formed between the insertion part and the mounting part, and the gap between the fixing member and the through-hole is maintained, allowing the valve body to tilt relative to the stem. Since the valve body tilts relative to the stem with the fixing member as the axis of rotation, and the axis of the valve body is adjusted to coincide with the axis of the valve seat, the maximum angle in which the valve body can tilt differs depending on the direction in which the valve body tilts relative to the stem. For this reason, depending on the direction in which the axis of the valve body is adjusted, it may not be possible to align the axis of the valve body with the axis of the valve seat. Also, if the axis of the stem is shifted laterally perpendicular to the axis of the valve seat, it may not be possible to align the axis of the valve body with the axis of the valve seat. Furthermore, when the valve body rotates with the stem and contacts the valve seat, the frictional force of the contact surface between the valve body and the valve seat hinders the rotation of the stem. On the other hand, in some devices and equipment where needle valves are used, the handle for rotating the stem may have to be made smaller due to space limitations and other factors. In such cases, it may be difficult to apply a strong rotational force to the stem, making it impossible to push the valve body down to the fully closed position.

[0009] The flow control valve disclosed in Patent Document 3 has a configuration in which a bolt is screwed into the tip of the stem, so there is a possibility that the bolt will loosen over time and the valve body may fall off the stem. In the case of a needle valve configured such that the stem rotates around an axis and moves axially back and forth, like a manual needle valve, the bolt is likely to loosen. In particular, when the valve body moves away from the valve seat or when the valve body comes into contact with the valve seat, the stem rotates while the rotation of the valve body is restricted by the frictional force with the valve seat, so the bolt is likely to loosen. Note that the flow control valve disclosed in Reference Document 3 is configured so that the stem moves axially back and forth without rotating around an axis, and the problem of bolt loosening is not considered at all. In addition, because the valve body and stem are pressed against each other by the tightening force of the bolt, the movement of the valve body relative to the stem may be restricted by the frictional force of the contact surface between the valve body and the stem. Note that if the tightening force of the bolt is reduced, the frictional force of the contact surface between the valve body and the stem can be reduced, but the bolt is likely to loosen. This invention has been made in view of the above-mentioned problems, and its objective is to provide a needle valve that is easy to assemble, has excellent self-aligning function, and is highly reliable. [Means for solving the problem]

[0010] The present invention comprises a stem, a connecting member having a neck portion that fits tightly to the tip of the stem and a head portion supported at the tip of the neck portion, a valve body connected to the stem via the connecting member, and a fixing member for fixing the connecting member to the stem. The valve body has a main valve body portion and a covering portion that is installed on the side of the main valve body portion facing the stem so as to cover the head portion of the connecting member, with a through hole formed through which the neck portion of the connecting member is inserted. A lateral gap perpendicular to the axial direction is provided between the valve body and the connecting member, and the valve body is movable within a certain range in the lateral direction relative to the stem and the connecting member. An axial gap is also provided between the valve body and the head of the connecting member, and the valve body can be tilted within a certain range relative to the stem and connecting member. The above problem is solved by a needle valve in which a lateral hole is formed in the fitting portion between the stem and the neck portion of the connecting member, and the fixing member is inserted into the lateral hole in the stem and the lateral hole in the neck portion of the connecting member to fix the connecting member to the stem.

[0011] In this needle valve, the stem and valve body are connected by a connecting member, allowing the size of the connecting member's head and the valve body to be designed regardless of the stem's diameter. Therefore, there are no constraints on the size of the valve body, unlike the structure disclosed in Patent Document 1. Furthermore, since the neck of the connecting member fits snugly into the tip of the stem, and the fixing member is inserted into the lateral hole of the stem and the lateral hole of the connecting member's neck to fix the connecting member to the stem, the valve body is not strongly pressed against the stem when it is connected to the stem via the connecting member. Therefore, the valve body can move smoothly laterally relative to the stem and the connecting member during centering. In addition, since the valve body can be guided by both the head of the connecting member and the tip of the stem, it is easy to hold the valve body in the desired position during centering. Therefore, this needle valve has excellent centering function. Moreover, during assembly, the neck of the connecting member is inserted through the covering portion of the valve body, and the covering portion is attached to the main part of the valve body. Attaching the cover to the main valve body is easier than when the long stem is inserted through the cover and the cover is attached to the main valve body. Furthermore, by fitting the neck of the connecting member to the tip of the stem and inserting the fixing member into the lateral hole of the fitting part, the valve body can be easily attached to the stem via the connecting member. It is also possible to attach and detach the valve body to the stem while the stem is attached to the hood.

[0012] The stem is configured to move axially while rotating around its axis, and the stem and connecting member may be rotatable relative to the valve body.

[0013] Even when the stem rotates around its axis and moves axially back and forth, as in a manual needle valve, the fixing member is inserted into the lateral hole of the stem and the lateral hole of the neck of the connecting member, fixing the connecting member to the stem. Therefore, the connecting member will not detach from the stem due to the rotation of the stem. Furthermore, the stem and connecting member are rotatable relative to the valve body. Moreover, as described above, when the valve body is connected to the stem via the connecting member, the valve body is not strongly pressed against the stem. Therefore, the stem and connecting member can rotate smoothly relative to the valve body, and the valve body can be pushed down to the fully closed position even if it is difficult to apply a strong rotational force to the stem.

[0014] In this case, the vehicle may further include a bonnet for housing the stem and a handle for manually rotating the stem, the handle being smaller in width laterally than the bonnet.

[0015] By making the handle smaller in width than the bonnet, the design flexibility for mounting the needle valve in devices and equipment can be increased. Furthermore, even if the handle is small and it is difficult to apply strong rotational force to the stem, the valve body can be pushed down to the fully closed position as described above. In addition, since the valve body can move smoothly laterally relative to the stem and connecting member during centering, the valve can be reliably centered and closed even if the handle is small and the force applied to the valve body against the valve seat is small.

[0016] The contact surface between the valve body and the valve seat is a conical surface, and the angle of inclination of the conical surface with respect to the axis may be in the range of 5 to 15°.

[0017] If the contact surface between the valve body and the valve seat is a conical surface, and the angle of inclination of the conical surface with respect to the axis is in the range of 5 to 15°, then even if the force pushing down the stem is weak, the force that brings the valve body into contact with the valve seat can be increased, and the valve body and valve seat can be securely sealed to close the valve.

[0018] A needle valve comprising a stem, a connecting member having a neck portion that fits tightly to the tip of the stem and a head supported at the tip of the neck portion, a valve body connected to the stem via the connecting member, and a fixing member for fixing the connecting member to the stem, wherein the valve body has a main valve body portion and a covering portion installed on the side of the main valve body portion facing the stem so as to cover the head of the connecting member, a lateral gap perpendicular to the axial direction is provided between the valve body and the connecting member, the valve body is movable within a certain range in the lateral direction relative to the stem and the connecting member, a lateral hole extending in the lateral direction is formed in the fitting portion between the stem and the neck portion of the connecting member, and the fixing member is inserted into the lateral hole of the stem and the lateral hole of the neck portion of the connecting member to fix the connecting member to the stem,It may further include a guide portion for slidably guiding the stem, and may be configured such that the fixing member is always positioned within the guide portion within the range where the stem moves forward and backward in the axial direction.

[0019] By configuring the fixing member to always be positioned within the guide portion, it is possible to reliably prevent the fixing member from falling off the stem.

[0020] A needle valve comprising a stem, a connecting member having a neck portion that fits tightly to the tip of the stem and a head supported at the tip of the neck portion, a valve body connected to the stem via the connecting member, and a fixing member for fixing the connecting member to the stem, wherein the valve body has a main valve body portion and a covering portion installed on the side of the main valve body portion facing the stem so as to cover the head of the connecting member, a lateral gap perpendicular to the axial direction is provided between the valve body and the connecting member, the valve body is movable within a certain range in the lateral direction relative to the stem and the connecting member, a lateral hole extending in the lateral direction is formed in the fitting portion between the stem and the neck portion of the connecting member, and the fixing member is inserted into the lateral hole of the stem and the lateral hole of the neck portion of the connecting member to fix the connecting member to the stem, It may further include a bonnet for accommodating the stem, a valve seat member fitted and attached to the valve body to which the bonnet is attached, and a valve seat holding spacer interposed between the bonnet and the valve seat member for holding the valve seat member.

[0021] Since the valve seat member is separate from the valve body, it is easy to process the contact surface with the valve body and the like. In addition, since the valve seat member is configured to fit into the valve body, it is easy to process the valve body and also easy to attach the valve seat member to the valve body. Furthermore, with a simple configuration in which the valve seat holding spacer is interposed between the bonnet and the valve seat member, the valve seat member can be reliably held at the installation position of the valve body.

Advantages of the Invention

[0022] According to the present invention, it is possible to realize a needle valve that is easy to assemble, has excellent centering function, and high reliability.

Brief Description of the Drawings

[0023] [Figure 1] Cross-sectional view showing the structure of the needle valve according to the first embodiment of the present invention [Figure 2] Cross-sectional view showing an enlarged view of the valve body of the needle valve and its periphery [Figure 3] Perspective view showing the overall structure of the manifold piping unit in which the needle valve is installed [Figure 4] Cross-sectional view showing a further enlarged view of the contact portion between the valve body and the valve seat of the needle valve [Figure 5] Cross-sectional view showing a state where the axes of the stem and the valve body of the needle valve are laterally displaced with respect to the axis of the valve seat [Figure 6] A cross-sectional view showing the state in which the axis of the valve body of the needle valve coincides with the axis of the valve seat due to alignment. [Figure 7] Cross-sectional view showing the structure of a needle valve according to a second embodiment of the present invention. [Figure 8] A cross-sectional view showing the valve body and surrounding area of ​​a needle valve according to the third embodiment of the present invention in an enlarged view. [Figure 9] Cross-sectional view showing the structure of a needle valve according to the fourth embodiment of the present invention. [Modes for carrying out the invention]

[0024] As shown in Figures 1 and 2, the needle valve 10 of the first embodiment includes a stem 12, a connecting member 14 having a neck portion 14A that fits tightly to the tip of the stem 12 and a head portion 14B supported at the tip of the neck portion 14A, a valve body 16 connected to the stem 12 via the connecting member 14, and a fixing member 18 that fixes the connecting member 14 to the stem 12. The valve body 16 has a valve body main portion 20 and a covering portion 22 that is installed on the side of the valve body main portion 20 facing the stem 12 so as to cover the head portion 14B of the connecting member 14, through which the neck portion 14A of the connecting member 14 is inserted. A lateral gap perpendicular to the axial direction is provided between the valve body 16 and the connecting member 14, and the valve body 16 is movable within a certain range in the lateral direction relative to the stem 12 and the connecting member 14. Laterally extending lateral holes 12A and 14C are formed in the fitting portion between the stem 12 and the neck portion 14A of the connecting member 14. The fixing member 18 is inserted into the lateral hole 12A of the stem 12 and the lateral hole 14C of the neck portion 14A of the connecting member 14, thereby fixing the connecting member 14 to the stem 12.

[0025] The needle valve 10 further comprises a bonnet 24 for housing the stem 12 and a handle 26 for manually rotating the stem 12.

[0026] The stem 12 is a stepped round bar that tapers in three stages from the tip to the base, and is composed of a tip section, an intermediate section, and a base section. The stem 12 is made of metal. A vertical hole 12B extending in the axial direction is formed at the tip of the tip section. The neck portion 14A of the connecting member 14 is fitted tightly into the vertical hole 12B. A horizontal hole 12A is formed to communicate with the vertical hole 12B from the outer circumferential surface near the tip end of the tip section. In addition, two horizontal holes 12A are formed on the tip section symmetrically with respect to the axis of the stem 12. A groove 12C is formed along the circumferential direction on the outer circumferential surface of the tip section, closer to the base than the horizontal hole 12A. An O-ring 28 is attached to the groove 12C. A male thread is formed on the outer circumferential surface of the intermediate section and is screwed into the female thread of the bonnet 24. A handle 26 is attached to the base section.

[0027] The bonnet 24 has a roughly square plate-like base portion 24A and a guide portion 24B that slidably guides the stem 12. The material of the bonnet 24 is resin or metal. A through hole is formed in the center of the base portion 24A, and the stem 12 is inserted through this through hole. The guide portion 24B is a cylindrical body formed coaxially with the through hole in the center of one face of the base portion 24A. The guide portion 24B is integrally formed with the base portion 24A. The tip portion of the stem 12 is slidably fitted inside the guide portion 24B. The gap between the inner circumferential surface of the guide portion 24B and the outer circumferential surface of the tip portion of the stem 12 is sealed by an O-ring 28. In addition, an annular boss is formed coaxially with the through hole in the center of the other face of the base portion 24A. A female thread is formed on the inner circumferential surface of the through hole in the base portion 24A. The male thread on the middle portion of the stem 12 is screwed into this female thread. The bonnet 24 is attached to the valve body 30 with screws (not shown) near its four corners.

[0028] The handle 26 is a disc-shaped body that is coaxially mounted on the base end of the stem 12 and fixed to the stem 12 with a screw 31. The material of the handle 26 is resin or metal. The diameter (lateral width) of the handle 26 is smaller than the lateral width of the bonnet 24. By rotating the handle 26, the stem 12 is configured to move axially while rotating around its axis. The stem 12 and the connecting member 14 are rotatable relative to the valve body 16.

[0029] The neck portion 14A of the connecting member 14 is a round rod-shaped body with a horizontal hole 14C that communicates with the horizontal hole 12A. The head portion 14B of the connecting member 14 is a disc-shaped body and is coaxially mounted at the tip of the neck portion 14A. The head portion 14B is formed integrally with the neck portion 14A. The material of the connecting member 14 is a metal such as stainless steel.

[0030] The fixing member 18 is a spring pin (roll pin). Specifically, the fixing member 18 is a cylindrical member with a portion of its circumference cut out along its longitudinal direction. The fixing member 18 is fitted tightly into the lateral hole 14C of the neck portion 14A of the connecting member 14. On the other hand, the fixing member 18 has a small gap between it and the lateral hole 12A of the stem 12. Alternatively, the fixing member 18 may be fitted tightly into the lateral hole 12A of the stem 12, while also having a small gap between it and the lateral hole 14C of the neck portion 14A of the connecting member 14. In these cases, inserting the fixing member 18 into the lateral hole 12A of the stem 12 and the lateral hole 14C of the neck portion 14A of the connecting member 14 is easy. Furthermore, the fixing member 18 may be fitted tightly into both the lateral hole 14C of the neck portion 14A of the connecting member 14 and the lateral hole 12A of the stem 12. In this case, for example, by forming the lateral holes 12A and 14C while the stem 12 and the neck portion 14A of the connecting member 14 are fitted together, the two lateral holes can be aligned with high precision. The fixing member 18 may also be a cylindrical pin without a notch. Alternatively, the fixing member 18 may be a solid round bar pin. Furthermore, the fixing member 18 may be fitted to the stem 12 at only one point in the circumferential direction of the stem 12. In this case, the lateral hole 12A of the stem 12 may be formed at only one point in the circumferential direction. The fixing member 18 may also be a screw. For example, the fixing member 18 may have a male thread in the portion inserted into the lateral hole 14C of the neck portion 14A of the connecting member 14, and a stepped round bar member that is thicker than the male thread in the portion inserted into the lateral hole 12A of the stem 12. In this case, a female thread is formed in the lateral hole 14C of the neck portion 14A of the connecting member 14. Furthermore, the fixing member 18 may have a male thread in the portion inserted into the lateral hole 12A of the stem 12, and a stepped round bar-shaped member that is thinner than the male thread in the portion inserted into the lateral hole 14C of the neck portion 14A of the connecting member 14. In this case, a female thread is formed in the lateral hole 12A of the stem 12. Also, if the fixing member 18 is a screw, a slotted or hexagonal recess is formed at the end of the fixing member 18 to engage with a tool.

[0031] The main valve body portion 20 of the valve body 16 has a roughly truncated frustoconical shape, and the portion of the outer circumferential surface closer to the tip than the portion near the base end is a conical surface in which the diameter decreases towards the tip. The valve body 16 is in contact with the valve seat, which will be described later, on this conical surface. In this invention, the term "needle valve" is used to mean a valve in which the valve body has a conical or spherical outer circumferential surface that decreases in diameter towards the tip, and the valve body moves back and forth in the axial direction to move away from or into contact with the valve seat, and is not limited to a valve in which the valve body is an elongated needle shape. The portion of the outer circumferential surface of the main valve body portion 20 near the base end is a cylindrical surface. A circular recess 20A is formed in the portion of the main valve body portion 20 closer to the base end to accommodate the head 14B of the connecting member 14. Furthermore, an annular recess 20B is formed around the recess 20A to accommodate the covering portion 22 of the valve body 16. The portion of the recess 20B that is radially outer is deeper than the portion that is inner. The main body of the valve 20 is made of a resin such as POM (polyoxymethylene) or a metal.

[0032] The covering portion 22 of the valve body 16 is a ring-shaped plate that is fitted and fixed into a recess 20B of the valve body main portion 20. The thickness of the covering portion 22 and the depth of the inner circumference of the recess 20B are approximately equal. As a result, the surface of the covering portion 22 facing the stem 12 and the surface of the valve body main portion 20 facing the stem 12 form a flat surface with almost no step difference. The outer circumference of the covering portion 22 protrudes toward the tip and is recessed radially outward from the inner circumference of the recess 20B. The material of the covering portion 22 is also a resin such as POM (polyoxymethylene) or metal. When the materials of the valve body main portion 20 and the covering portion 22 are resin, the covering portion 22 is fixed to the valve body main portion 20 by welding, bonding, or press-fitting. When the materials of the valve body main portion 20 and the covering portion 22 are metal, the covering portion 22 is fixed to the valve body main portion 20 by welding, brazing, bonding, or press-fitting.

[0033] The diameter of the through-hole in the covering portion 22 is larger than the diameter of the neck portion 14A of the connecting member 14. Also, the diameter of the recess 20A in the main valve body portion 20 is larger than the diameter of the head portion 14B of the connecting member 14. This creates a lateral gap perpendicular to the axial direction between the valve body 16 and the connecting member 14. Note that the diameter of the through-hole in the covering portion 22 is smaller than the diameter of the head portion 14B of the connecting member 14. Also, the axial gap between the bottom surface of the recess 20A in the main valve body portion 20 and the covering portion 22 is larger than the thickness of the head portion 14B of the connecting member 14. This creates an axial gap between the valve body 16 and the head portion 14B of the connecting member 14. Because an axial gap is also formed between the valve body 16 and the head portion 14B of the connecting member 14, the valve body 16 can move smoothly laterally relative to the head portion 14B of the connecting member 14 during centering. In addition, the valve body 16 can be tilted within a certain range relative to the stem 12 and the connecting member 14. When the axis of the stem 12 is inclined with respect to the axis of the valve seat 32, the valve body 16 can be tilted to make close contact with the valve seat 32. The head 14B of the connecting member 14 is in contact with the bottom surface of the recess 20A of the main part of the valve body 20, and the tip of the stem 12 is in contact with the base end of the valve body 16. This allows the valve body 16 to be guided by both the head 14B of the connecting member 14 and the tip of the stem 12, making it easier to hold the valve body 16 in the desired position during centering. Alternatively, the head 14B of the connecting member 14 may be in contact with the bottom surface of the recess 20A of the main part of the valve body 20, and the tip of the stem 12 may be spaced axially away from the base end of the valve body 16. In this case as well, the tip of the stem 12 functions as a guide that restricts the upper limit of the tilt angle of the valve body 16. Alternatively, the head 14B of the connecting member 14 may be configured such that, with the tip of the stem 12 in contact with the base end of the valve body 16, the head 14B of the connecting member 14 is spaced axially away from the bottom surface of the recess 20A of the main valve body 20. In this case, the tip of the stem 12 functions as the main guide during alignment. The head 14B of the connecting member 14 may be sandwiched between the main valve body 20 (the bottom surface of the recess 20A) and the covering portion 22, so that no axial gap is formed between the valve body 16 and the head 14B of the connecting member 14. In this case, the valve body 16 can be guided laterally so that it does not tilt.In this case, if the tip of the stem 12 is configured to contact the base end of the valve body 16, the valve body 16 can be guided laterally even more reliably to prevent it from tilting. However, if the head 14B of the connecting member 14 alone can guide the valve body 16 laterally to prevent it from tilting, the tip of the stem 12 may be configured to be spaced axially away from the base end of the valve body 16.

[0034] As shown in Figure 3, the needle valve 10 is installed in the manifold piping unit 50. The manifold piping unit 50 comprises an inlet main channel 52, a plurality of inlet branch channels 54 connected downstream of the inlet main channel 52, an outlet main channel 56, and a plurality of outlet branch channels 58 connected upstream of the outlet main channel 56. The number of inlet branch channels 54 and the number of outlet branch channels 58 are the same, and each inlet branch channel 54 is connected to one outlet branch channel 58 via piping (not shown). The cooling water (fluid) received by the inlet main channel 52 is supplied to the object to be cooled (not shown) via the plurality of inlet branch channels 54. The object to be cooled is, for example, a dry etching apparatus or a film deposition apparatus for manufacturing semiconductors. The cooling water, whose temperature has risen after cooling the object to be cooled, is discharged from the outlet main channel 56 via the plurality of outlet branch channels 58. The cooling water discharged from the outlet main channel 56 is temperature-controlled by a chiller (not shown) and then supplied back to the inlet main channel 52. Each inlet branch channel 54 is equipped with an on / off valve 66.

[0035] Needle valves 10 are installed in each outlet branch channel 58. Drain valves 60 and flow meters 62 are also installed in each outlet branch channel 58. These needle valves 10, drain valves 60 and flow meters 62 are installed adjacent to each other along the outlet branch channel 58. In addition, multiple sets of these needle valves 10, drain valves 60 and flow meters 62 are installed adjacent to each other corresponding to multiple outlet branch channels 58. Multiple needle valves 10 are installed adjacent to each other along the outlet main channel 56. In addition, multiple drain valves 60 are installed adjacent to each other along the common drain channel 64. The drain valves 60 can be switched between an operation mode in which the port on the flow meter 62 side communicates with the port on the needle valve 10 side, and the port on the common drain channel 64 side does not communicate with these two ports, and a maintenance mode in which the port on the flow meter 62 side communicates with the port on the common drain channel 64 side, and the port on the needle valve 10 side does not communicate with the other two ports. The needle valve 10 is used to adjust the flow rate of cooling water flowing from the outlet branch passage 58 to the outlet main passage 56, or to block the flow.

[0036] The valve body 30 to which the bonnet 24 of the needle valve 10 is attached constitutes part of the outlet main passage 56 and the outlet branch passage 58. The part of the valve body 30 opposite to the outlet branch passage 58 is closed off by a cover member 68. A valve seat 32 that contacts the valve body 16 is formed on the valve body 30. As shown in Figure 4, both the contact surface of the valve body main portion 20 of the valve body 16 and the valve seat 32 are conical surfaces, and the angle of inclination of the conical surface with respect to the axis is in the range of 5 to 15°. The angle of inclination of the conical surface of the valve body main portion 20 of the valve body 16 with respect to the axis is equal to the angle of inclination of the conical surface of the valve seat 32 with respect to the axis. For example, the angle of inclination of the conical surface of the valve body main portion 20 of the valve body 16 with respect to the axis is 10°, and the angle of inclination of the conical surface of the valve seat 32 with respect to the axis is also 10°. Note that the angle of inclination of the conical surface of the main part 20 of the valve body 16 with respect to the axis and the angle of inclination of the conical surface of the valve seat 32 with respect to the axis may be different.

[0037] Next, the operation and effect of the needle valve 10 will be explained. Due to errors that occur in the manufacturing process, the axis C2 of the stem 12 may be misaligned laterally with the axis C1 of the valve seat 32, as shown in Figure 5. In this case, when the valve body 16 contacts the valve seat 32 when closing the valve, the valve body 16 is biased laterally by the reaction force of the conical surface that contacts the valve seat 32, and moves laterally relative to the stem 12 and the connecting member 14. As a result, as shown in Figure 6, even if the axis C2 of the stem 12 is misaligned laterally with the axis C1 of the valve seat 32, the axis of the valve body 16 coincides with the axis C1 of the valve seat 32, and the valve closes. The needle valve 10 is configured such that the neck portion 14A of the connecting member 14 fits tightly to the tip of the stem 12, and the fixing member 18 is inserted into the lateral hole 12A of the stem 12 and the lateral hole 14C of the neck portion 14A of the connecting member 14 to fix the connecting member 14 to the stem 12. Therefore, when the valve body 16 is connected to the stem 12 via the connecting member 14, the valve body 16 is not strongly pressed against the stem 12. Consequently, the valve body 16 can move smoothly laterally relative to the stem 12 and the connecting member 14 during centering. Furthermore, since the valve body 16 can be guided by both the head portion 14B of the connecting member 14 and the tip of the stem 12, it is easy to hold the valve body 16 in the desired position during centering. Therefore, the needle valve 10 has excellent centering function. Note that if an axial gap is also formed between the valve body 16 and the head portion 14B of the connecting member 14, the valve body 16 can tilt within a certain range relative to the stem 12 and the connecting member 14. Therefore, even if the axis C2 of the stem 12 is inclined with respect to the axis C1 of the valve seat 32, the axis of the valve body 16 coincides with the axis C1 of the valve seat 32 and the valve closes.

[0038] Furthermore, although the needle valve 10 is configured such that the stem 12 rotates around its axis while moving axially, the fixing member 18 is inserted into the lateral hole 12A of the stem 12 and the lateral hole 14C of the neck portion 14A of the connecting member 14 to fix the connecting member 14 to the stem 12, so that the connecting member 14 does not fall off the stem 12 due to the rotation of the stem 12. In addition, the stem 12 and the connecting member 14 are rotatable relative to the valve body 16. Moreover, as described above, when the valve body 16 is connected to the stem 12 via the connecting member 14, the valve body 16 is not strongly pressed against the stem 12. Therefore, the stem 12 and the connecting member 14 can rotate smoothly relative to the valve body 16, and the valve body 16 can be pushed down to the fully closed position even if it is difficult to apply a strong rotational force to the stem 12.

[0039] Furthermore, since the needle valve 10 has a compact configuration in which the handle 26 is smaller in width laterally than the bonnet 24, the degree of freedom in the design of mounting the needle valve in devices and equipment can be increased. For example, when multiple needle valves 10 are installed adjacent to each other, such as in a manifold piping unit 50, or when a drain valve 60 or flow meter 62 is installed adjacent to the needle valve 10, the degree of freedom in the design of the arrangement of these components is high, and the manifold piping unit 50 as a whole can be made compact. In addition, even if the handle 26 is small and it is difficult to apply a strong rotational force to the stem 12, the valve body 16 can be pushed down to the completely closed position as described above. Moreover, since the valve body 16 can move smoothly laterally relative to the stem 12 and connecting member 14 when centering, even if the handle 26 is small and the force applied to bring the valve body 16 into contact with the valve seat 32 is small, the valve can be reliably centered and closed.

[0040] Furthermore, during assembly, the neck portion 14A of the connecting member 14 is inserted through the covering portion 22 of the valve body 16, and the covering portion 22 is attached to the main body 20 of the valve body. This makes it easier to attach the covering portion 22 to the main body 20 of the valve body than when the long stem 12 is inserted through the covering portion 22 of the valve body 16 and the covering portion 22 is attached to the main body 20 of the valve body. In addition, the valve body 16 can be easily attached to the stem 12 via the connecting member 14 by fitting the neck portion 14A of the connecting member 14 to the tip of the stem 12 and inserting the fixing member 18 into the lateral holes 12A and 14C of the fitting portion. It is also possible to attach and detach the valve body 16 to the stem 12 while the stem 12 is attached to the bonnet 24.

[0041] Next, a second embodiment will be described. In the needle valve 10 of the first embodiment, the lateral hole 12A of the stem 12 is formed near the tip end of the tip portion, whereas in the needle valve 70 of the second embodiment, as shown in Figure 7, the lateral hole 72A of the stem 72 is formed near the base end of the tip portion. This is configured so that the fixing member 18 is always positioned within the guide portion 24B within the range in which the stem 72 moves back and forth in the axial direction. The tip portion of the stem 72 is longer than the tip portion of the stem 12 of the first embodiment. The lateral hole 72A is formed on the base end side of the groove 72C to which the O-ring 28 is attached. Also, the neck portion 74A of the connecting member 74 is longer than the neck portion 14A of the connecting member 14 of the first embodiment. A groove 74D is formed along the circumferential direction on the tip side of the lateral hole 74C in the neck portion 74A of the connecting member 74. An O-ring 76 is attached to the groove 74D. The gap between the inner surface of the vertical hole 72B of the stem 72 and the outer surface of the neck portion 74A of the connecting member 74 is sealed by an O-ring 76. The other components are the same as in the first embodiment, so the same components are denoted by the same reference numerals as in Figures 1 to 6 and their description is omitted. By configuring the fixing member 18 to always be located within the guide portion 24B in this way, it is possible to reliably prevent the fixing member 18 from falling off the stem 72.

[0042] Next, a third embodiment will be described. As shown in Figure 8, the needle valve 80 of the third embodiment includes a valve seat member 84 fitted and mounted on a valve body 82 to which a bonnet 24 is attached, and a valve seat holding spacer 86 interposed between the bonnet 24 and the valve seat member 84 to hold the valve seat member 84. The valve seat member 84 is substantially cylindrical, and a valve seat 84A is formed on the inner circumferential surface of its base end. The shape of the valve seat 84A is the same conical surface as the valve seat 32 of the first embodiment. A groove 84B is formed on the outer circumferential surface of the valve seat member 84 along the circumferential direction. An O-ring 88 is attached to the groove 84B. The outer circumferential surface of the valve seat member 84 has a stepped shape, with the outer diameter being larger near the base end than other parts. The material of the valve seat member 84 is resin or metal. The portion of the valve body 82 in which the valve seat member 84 is installed (the portion adjacent to the outlet main flow path 56 of the manifold piping unit) is a stepped, substantially cylindrical surface corresponding to the outer circumferential surface of the valve seat member 84. The valve seat member 84 fits into this portion, and the stepped shape of the valve body 82 prevents it from moving in the direction of insertion into the valve body 82 (away from the bonnet 24). The material of the valve body 82 is resin or metal.

[0043] The valve seat retaining spacer 86 is substantially cylindrical, with an opening in the portion adjacent to the outlet branch passage 58 of the manifold piping unit 50 (the left portion in Figure 8). The tip of the valve seat retaining spacer 86 faces the boundary between the base end of the valve seat member 84 and the valve body 82, with a portion abutting against or being close to the base end of the valve seat member 84, and the other portion abutting against or being close to the valve body 82. On the other hand, the base end of the valve seat retaining spacer 86 engages with the tip of the guide portion 24B of the bonnet 24. More specifically, the inner circumferential surface of the valve seat retaining spacer 86 has a stepped shape in which the portion near the base end has a larger diameter than the outer circumferential surface of the guide portion 24B, and the other portion has a smaller diameter than the outer circumferential surface of the guide portion 24B. At this stepped portion, the valve seat retaining spacer 86 engages with the tip portion of the guide portion 24B. The valve seat member 84 is prevented from moving in the direction that would remove it from the valve body 82 (towards the bonnet 24) by the valve seat retaining spacer 86, and is held in place in its installation position on the valve body 82. The material of the valve seat retaining spacer 86 is resin or metal. The other components are the same as in the first embodiment, so the same components are denoted by the same reference numerals as in Figures 1 to 6 and their description is omitted.

[0044] Since the valve seat member 84 is separate from the valve body 82, processing of the valve seat 84A and other components is easy. Furthermore, since the valve seat member 84 is configured to fit into the valve body 82, processing of the valve body 82 is easy, and attaching the valve seat member 84 to the valve body 82 is also easy. In addition, the valve seat retaining spacer 86 is interposed between the guide portion 24B of the bonnet 24 and the valve seat member 84 in a simple configuration, which ensures that the valve seat member 84 is securely held in place. In the third embodiment, the valve seat retaining spacer 86 is interposed between the guide portion 24B of the bonnet 24 and the valve seat member 84, but the valve seat retaining spacer may also be interposed between another part of the bonnet and the valve seat member.

[0045] Next, the fourth embodiment will be described. The needle valves 10, 70, and 80 of the first to third embodiments are manually operated with a handle 26, and the stems 12 and 72 move axially back and forth while rotating around an axis. In contrast, as shown in Figure 9, the needle valve 90 of the fourth embodiment is electrically operated with a motor 100, and the stem 92 moves axially back and forth without rotating around an axis. The stem 92 is a stepped round rod-shaped body that thickens in two stages from the tip to the base, and is composed of a tip side portion and a base side portion. The tip side portion of the stem 92 has the same configuration as the tip side portion of the stem 12 of the first embodiment. The base side portion of the stem 92 is cylindrical and has an internal thread formed on its inner surface.

[0046] The bonnet 94 has a roughly square plate-shaped base portion 94A, a guide portion 94B that slidably guides the tip portion of the stem 92, and a guide portion 94C that slidably guides the base portion of the stem 92. The guide portion 94B is formed on one side of the base portion 94A, and the guide portion 94C is formed on the other side of the base portion 94A. The bonnet 94 has a stepped through hole that corresponds to the stepped round bar-shaped stem 12. The guide portion 94C is engaged with the stem 92 by a spline or the like that runs along the axial direction (not shown), and the stem 92 is configured to move back and forth in the axial direction without rotating around its axis.

[0047] A male threaded member 96 is screwed into the female thread on the inside of the base end portion of the stem 92. The male threaded member 96 is connected to the rotating shaft of the motor 100. The motor 100 is mounted on the end of the guide portion 94C of the bonnet 94. When the male threaded member 96 rotates together with the rotating shaft of the motor 100, the stem 92 is configured to move back and forth in the axial direction without rotating around the axis. The other components are the same as in the first embodiment, so the same components are denoted by the same reference numerals as in Figures 1 to 6 and their description is omitted.

[0048] Even when the stem 92 is configured to move axially without rotating around its axis, the valve body 16 is not strongly pressed against the stem 92 when it is connected to the stem 92 via the connecting member 14. Therefore, the valve body 16 can move smoothly laterally relative to the stem 92 and the connecting member 14 during centering. Furthermore, since the valve body 16 can be guided by both the head 14B of the connecting member 14 and the tip of the stem 92, it is easy to hold the valve body 16 in the desired position during centering. Thus, the needle valve 90 also has excellent centering capabilities.

[0049] Furthermore, the present invention is also applicable to electric needle valves equipped with a motor, in which the stem rotates around an axis and moves back and forth in the axial direction. For example, the present invention is also applicable to needle valves in which a motor that rotates the stem 12, 72 is attached in place of the handle 26 of the needle valves 10, 70, 80 of the first to third embodiments.

[0050] Furthermore, in the first to fourth embodiments, vertical holes 12B and 72B are formed at the tips of the stems 12, 72, and 92, and the neck portions 14A and 74A of the connecting members 14 and 74 are inserted into the vertical holes 12B and 72B of the stems 12, 72, and 92 in close contact, thereby fitting tightly to the tips of the stems 12, 72, and 92. However, it is also possible to have a configuration in which a vertical hole is formed at the base end of the neck portion of the connecting member, and the tip of the stem is inserted into the vertical hole in the neck portion of the connecting member, so that the neck portion of the connecting member fits tightly to the tip of the stem.

[0051] Furthermore, in the first to fourth embodiments, the covering portion 22 of the valve body 16 fits into the recess 20B of the valve body main portion 20, and the surface of the covering portion 22 facing the stems 12, 72, and 92 and the surface of the valve body main portion 20 facing the stems 12, 72, and 92 form a flat surface with almost no step difference. However, it is also possible to have a configuration where there is no recess 20B and there is a step difference between the surface of the covering portion 22 facing the stems and the surface of the valve body main portion 20 facing the stems 12, 72, and 92. Also, in the first to fourth embodiments, a circular recess 20A is formed on the base end side of the valve body main portion 20 to accommodate the heads 14B and 74B of the connecting members 14 and 74. However, it is also possible to have a configuration where there is no recess 20A and the covering portion accommodates the heads 14B and 74B of the connecting members 14 and 74. For example, the covering portion may have a configuration in which a disc-shaped body has a through hole through which the neck portions 14A and 74A of the connecting members 14 and 74 pass, and which is close to or in contact with the side surface of the stem of the head portion 14B and 74B of the connecting members 14 and 74, and a cylindrical peripheral wall that surrounds the outer circumferential surface of the head portion 14B and 74B of the connecting members 14 and 74.

[0052] Furthermore, in the first to third embodiments, the handle 26 is disc-shaped, but the shape of the handle is not particularly limited. Also, in the first to third embodiments, the handle 26 has a smaller diameter (lateral width) than the bonnet 24, but the present invention is also applicable to needle valves in which the diameter (lateral width) of the handle is larger than the diameter (lateral width) of the bonnet 24.

[0053] Furthermore, in the first to fourth embodiments, the guide portions 24B, 94B, and 94C that guide the stems 12, 72, and 92 in the axial direction are installed on the bonnets 24 and 94, and the valve seats 32 and 84A are installed on the valve bodies 30 and 82. However, the present invention is also applicable to needle valves in which the guide portions that guide the stems in the axial direction and the valve seats are installed on a common valve body.

[0054] Furthermore, in the first to fourth embodiments, the outer circumferential surface of the main valve body portion 20 of the valve body 16 is a conical surface whose diameter decreases towards the tip. However, the present invention is also applicable to needle valves in which the outer circumferential surface of the main valve body portion is a spherical surface whose diameter decreases towards the tip.

[0055] Furthermore, in the first to fourth embodiments, the diameter of the valve body 16 is larger than the diameter of the stem 12, but the present invention is also applicable to needle valves in which the diameter of the valve body and the diameter of the stem are equal, and to needle valves in which the diameter of the valve body is smaller than the diameter of the stem.

[0056] Furthermore, while the first to fourth embodiments show examples in which needle valves 10, 70, 80, and 90 are installed in a manifold piping unit 50, the needle valves of the present invention are applicable to a variety of devices and equipment. [Industrial applicability]

[0057] This invention can be used in various devices and equipment to adjust the flow rate of fluids such as cooling water or to interrupt the flow. [Explanation of Symbols]

[0058] 10, 70, 80, 90 Needle Valves 12, 72, 92 stem 12A, 14C, 72A, 74C Side holes 12B, 72B vertical hole 12C Groove 14, 74 Connecting members 14A, 74A neck 14B Head 16 Valve body 18 Fixing member 20 Valve body main part 22 Covering part 24 Hood 24A, 94A base section 24B, 94B, 94C Guide Section 26 handle 28, 76, 88 O-rings 30, 82 Valve Body 32, 84A valve seat 50 Manifold Piping Units 52 Main inlet channel 54 Inlet branch channel 56 Outlet main channel 58 Exit branch channel 60 Drain valve 62 Flow meter 64 Common drain channel 66 Shut-off valves 68 Lid member 84 Valve seat member 84B Groove 86 Valve seat retaining spacer 96 Male thread standard 100 motor

Claims

1. Stem and a connecting member having a neck portion that fits closely to the tip portion of the stem and a head portion supported on the tip portion of the neck portion; a valve body connected to the stem via the connecting member; a fixing member that fixes the connecting member to the stem, The valve body has a valve body main portion and a covering portion having a through hole through which a neck portion of the connecting member is inserted and disposed on a side of the valve body main portion facing the stem so as to cover a head of the connecting member, A lateral gap perpendicular to an axial direction is provided between the valve body and the connecting member, and the valve body is movable in the lateral direction relative to the stem and the connecting member within a certain range, A gap is also provided between the valve body and the head of the connecting member in the axial direction, and the valve body can be tilted within a certain range relative to the stem and the connecting member, A horizontal hole extending in the horizontal direction is formed at the mating portion between the stem and the neck of the connecting member, and the fixing member is inserted into the horizontal hole of the stem and the horizontal hole of the neck of the connecting member to fix the connecting member to the stem.

2. In claim 1, The needle valve is configured so that the stem moves back and forth in the axial direction while rotating about an axis, and the stem and the connecting member are rotatable relative to the valve body.

3. In claim 2, a bonnet that houses the stem; and a handle for manually rotating the stem; The handle of the needle valve has a width in the lateral direction smaller than that of the bonnet.

4. In claim 1, The contact surface between the valve body and the valve seat is a conical surface, and the inclination angle of the conical surface with respect to the axis is in the range of 5 to 15 degrees.

5. A stem; a connecting member having a neck portion that fits closely to the tip portion of the stem and a head portion supported on the tip portion of the neck portion; a valve body connected to the stem via the connecting member; a fixing member that fixes the connecting member to the stem, The valve body has a valve body main portion and a covering portion having a through hole through which a neck portion of the connecting member is inserted and disposed on a side of the valve body main portion facing the stem so as to cover a head of the connecting member, A lateral gap perpendicular to an axial direction is provided between the valve body and the connecting member, and the valve body is movable in the lateral direction relative to the stem and the connecting member within a certain range, a lateral hole extending in the lateral direction is formed at a fitting portion between the stem and the neck portion of the connecting member, and the fixing member is inserted into the lateral hole of the stem and the lateral hole of the neck portion of the connecting member to fix the connecting member to the stem; The needle valve further comprises a guide portion that slidably guides the stem, and the fixing member is always positioned within the guide portion within a range in which the stem moves back and forth in the axial direction.

6. A stem; a connecting member having a neck portion that fits closely to the tip portion of the stem and a head portion supported on the tip portion of the neck portion; a valve body connected to the stem via the connecting member; a fixing member that fixes the connecting member to the stem, The valve body has a valve body main portion and a covering portion having a through hole through which a neck portion of the connecting member is inserted and disposed on a side of the valve body main portion facing the stem so as to cover a head of the connecting member, A lateral gap perpendicular to an axial direction is provided between the valve body and the connecting member, and the valve body is movable in the lateral direction relative to the stem and the connecting member within a certain range, a lateral hole extending in the lateral direction is formed at a fitting portion between the stem and the neck portion of the connecting member, and the fixing member is inserted into the lateral hole of the stem and the lateral hole of the neck portion of the connecting member to fix the connecting member to the stem; a bonnet that accommodates the stem, a valve seat member that is fitted into and attached to a valve body to which the bonnet is attached, and a valve seat retaining spacer that is interposed between the bonnet and the valve seat member to retain the valve seat member.

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