Inner ring and pipe joint
By forming a conical surface at the axial end of the inner ring and controlling the starting position of the diameter expansion, the problem of the inner circumference of the inner ring protruding into the fluid flow path is solved, ensuring fluid flow stability and sealing performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NIPPON PILLAR PACKING CO LTD
- Filing Date
- 2021-03-09
- Publication Date
- 2026-06-02
AI Technical Summary
The axial end of the inner circumferential surface of the inner ring of the existing pipe fitting tends to bulge into the fluid flow path during fluid flow, resulting in decreased fluid flow characteristics and poor flushing.
Conical surfaces are formed at one end and the other end of the inner ring along the axial direction. The starting point of the diameter expansion of the conical surface is located before the starting point of deformation or at a position corresponding to the main body, so as to ensure that the inner circumferential surface does not deform excessively inward in the radial direction when subjected to force, forming a constant outer diameter portion to reduce the amount of deformation.
It effectively suppresses the axial end of the inner circumferential surface of the inner ring from protruding into the fluid flow path, maintaining the stability of fluid flow and sealing performance.
Smart Images
Figure CN115769009B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to inner rings and pipe fittings. Background Technology
[0002] In manufacturing processes across various technological fields, including semiconductor manufacturing, medical / pharmaceutical manufacturing, and food processing / chemical industries, pipe fittings made of synthetic resin are used as connection structures to connect pipes and flow paths formed in fluid equipment for piping paths that flow through fluids such as pharmaceutical solutions, high-purity liquids, ultrapure water, or cleaning solutions. One known pipe fitting has the following components: an inner ring mounted on the inner circumference of the front end of the pipe; a cylindrical fitting body mounted on the outer circumference of the front end of the pipe; and a connecting nut mounted on the outer circumference of the fitting body (see, for example, Patent Document 1).
[0003] like Figure 5 As shown, the inner ring 110 of the current pipe fitting 100 has: a cylindrical main body portion 111; a bulge portion 112 formed at one axial end of the main body portion 111; and a press-in portion 113 formed at the other axial end of the main body portion 111. A fluid flow path 114 is formed inside the inner ring 110. The bulge portion 112 is formed to protrude radially outward from the main body portion 111 and is pressed into the front end of the pipe 120. The press-in portion 113 is formed to protrude axially from the main body portion 111, and if the connecting nut 130 is tightened, the press-in portion 113 is pressed into the end of the fitting body 140.
[0004] If the bulge 112 and the press-in portion 113 of the inner ring 110 are pressed into the front end of the pipe 120 and the end of the connector body 140, respectively, the axial ends of the inner ring 110 are pressed radially inward, causing the axial ends of the inner circumferential surface of the inner ring 110 to deform in a radially inward manner. At this time, if the axial ends of the inner circumferential surface of the inner ring 110 protrude into the fluid flow path 114, the displacement characteristics of the fluid flowing in the pipe connector 100 decrease, resulting in adverse effects such as the need for time to flush the pipe connector 100.
[0005] Therefore, as Figure 6 As shown, tapered surfaces 115 and 116, which gradually expand in diameter from the inner side to the outer side, are formed at both axial ends of the inner circumferential surface of the inner ring 110. Thus, even if the two axial ends of the inner ring 110 are pressed radially inward, the two axial ends of the inner circumferential surface of the inner ring 110 are prevented from protruding into the fluid flow path 114.
[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-168947 Summary of the Invention
[0007] like Figure 7As shown, at one axial end of the inner ring 110, when the axial length L' of the conical surface 115 is relatively short, the radially inward deformation allowance at one axial end of the inner circumferential surface of the inner ring 110 is insufficient. Therefore, as... Figure 8 As shown, if the bulge 112 of the inner ring 110 is pressed into the front end of the tube 120, it is impossible to suppress the bulging of one axial end of the inner circumferential surface of the inner ring 110 into the fluid flow path 114. In addition, without illustration, the same problem as the case where the axial length of the conical surface 116 is short occurs at the other axial end of the inner ring 110.
[0008] like Figure 9 As shown, at one axial end of the inner ring 110, when the axial length L' of the conical surface 115 is relatively long, the radial thickness (cross-sectional area) of one axial end of the inner ring 110 is excessively reduced. Therefore, as... Figure 10 As shown, if the bulge 112 of the inner ring 110 is pressed into the front end of the tube 120, the axial end of the inner circumferential surface of the inner ring 110 is more likely to tilt radially inward, making it impossible to suppress the protrusion into the fluid flow path 114. In addition, without showing the figure, the same problem as the case where the axial length of the conical surface 116 is longer occurs at the other axial end of the inner ring 110.
[0009] The present invention was proposed in view of this situation, and its purpose is to effectively suppress the axial end of the inner circumferential surface of the inner ring from protruding into the fluid flow path.
[0010] (1) The inner ring of the present invention has: a bulge portion formed at one axial end such that it protrudes radially outward from the outer circumferential surface and is pressed into the front end of the tube; a press-in portion formed at the other axial end and pressed into the end of the connector body; and a cylindrical body portion formed between the bulge portion and the press-in portion, having a constant outer diameter throughout the entire axial direction, the outer diameter being smaller than the maximum outer diameter of the bulge portion, and a fluid flow path formed on the inner side of the inner circumferential surface. In the state before the bulge portion is pressed into the front end of the tube, the inner circumferential surface at one axial end has a conical surface formed to gradually expand from the other axial side toward one axial end. The starting point of the expansion of the conical surface is located within a range from the deformation starting point position, which is the starting point of the deformation of the inner circumferential surface due to the external force exerted on the bulge portion by the tube when the bulge portion is pressed into the front end of the tube, to the position of the inner circumferential surface corresponding to the axial end of the outer circumferential surface of the body portion.
[0011] According to the inner ring of the present invention, the starting point of the expansion of the conical surface formed at one axial end in the inner circumferential surface of the inner ring is not located further axially than the starting point of deformation, which is the starting point of deformation of the inner circumferential surface due to external force applied to the bulge from the tube. Therefore, deformation of the starting point of the expansion of the conical surface radially inward due to the external force can be suppressed, thus ensuring sufficient radially inward deformation margin at one axial end of the inner circumferential surface of the inner ring.
[0012] Furthermore, the starting point of the conical expansion is not located further axially than the position on the inner circumferential surface corresponding to the axial end of the outer circumferential surface of the main body. That is, the starting point of the conical expansion is not located in the portion where the radial thickness of the inner ring is reduced. Therefore, even when a conical surface is formed, excessive reduction in the radial thickness (cross-sectional area) of the axial end of the inner ring can be suppressed, thus suppressing the degree of radial inward deformation of the axial end of the inner circumferential surface of the inner ring.
[0013] As described above, it can effectively suppress the axial end of the inner circumferential surface of the inner ring from protruding into the fluid flow path.
[0014] (2) Preferably, a maximum outer diameter portion, which is the maximum outer diameter, is formed on the outer peripheral surface of the bulge portion over a predetermined length along the axial direction, and the starting point of the diameter expansion of the conical surface is located within the range of the inner peripheral surface corresponding to the range of the predetermined length of the maximum outer diameter portion.
[0015] In this case, the starting point of the conical expansion is located at the part with the greatest radial thickness of the bulge, so even if a conical surface is formed, the degree of radial thickness reduction at one end of the inner ring can be suppressed. Therefore, the degree of radial inward deformation of one end of the inner circumferential surface of the inner ring can be further suppressed.
[0016] (3) Preferably, the deformation starting point is located on the inner circumferential surface corresponding to one axial end of the maximum outer diameter portion, and the diameter expansion starting point of the conical surface is located at the deformation starting point.
[0017] In this case, it is possible to suppress the radial inward deformation of the starting point of the conical surface due to the external force, and to minimize the degree of radial thickness reduction at one axial end of the inner ring. Therefore, it is possible to further suppress the degree of radial inward deformation of one axial end of the inner circumferential surface of the inner ring.
[0018] (4) According to other viewpoints, the inner ring of the present invention has: a bulge portion formed at one axial end such that it protrudes radially outward from the outer circumferential surface and is pressed into the front end of the tube; a press-in portion formed at the other axial end and pressed into the end of the connector body; and a cylindrical body portion formed between the bulge portion and the press-in portion, having a constant outer diameter throughout the entire axial direction, the outer diameter being smaller than the outer diameter of the press-in portion, a fluid flow path being formed on the inner side of the inner circumferential surface, and in the state before the press-in portion is pressed into the end of the connector body, having a conical surface at the other axial end of the inner circumferential surface formed to gradually expand in diameter from one axial side toward the other axial end, the starting point of the expansion of the conical surface being located within a range from the deformation starting point position, which is the starting point of the deformation of the inner circumferential surface due to the external force exerted on the press-in portion from the connector body when the press-in portion is pressed into the end of the connector body, to the position of the inner circumferential surface corresponding to the other axial end of the outer circumferential surface of the body portion.
[0019] According to the inner ring of the present invention, the starting point of the expansion of the conical surface formed at the other axial end in the inner circumferential surface of the inner ring is not located further axially than the starting point of deformation, which is the starting point of deformation of the inner circumferential surface due to the external force exerted on the press-in portion from the joint body. Therefore, deformation of the expansion starting point of the conical surface radially inward due to the external force can be suppressed, thus ensuring a radially inward deformation allowance at the other axial end of the inner circumferential surface of the inner ring.
[0020] Furthermore, the starting point of the conical expansion is not located further axially than the position of the inner circumferential surface corresponding to the other axial end of the outer circumferential surface of the main body. That is, the starting point of the conical expansion is not located in the portion where the radial thickness of the inner ring is reduced. Thus, even when a conical surface is formed, excessive reduction in the radial thickness (cross-sectional area) of the other axial end of the inner ring can be suppressed, thereby suppressing the degree of radial inward deformation of the other axial end of the inner circumferential surface of the inner ring.
[0021] As described above, it can effectively suppress the axial protrusion of the other end of the inner circumferential surface of the inner ring into the fluid flow path.
[0022] (5) Preferably, the starting point of the diameter expansion of the conical surface is located at the starting point of the deformation.
[0023] In this case, the radial inward deformation of the starting point of the conical surface due to the external force can be suppressed, and the degree of radial thickness reduction at the other axial end of the inner ring can be minimized. Therefore, the degree of radial inward deformation at the other axial end of the inner circumferential surface of the inner ring can be further suppressed.
[0024] (6) According to other viewpoints, the pipe fitting of the present invention has: a fitting body having an external threaded portion formed on its outer periphery; a connecting nut having an internal threaded portion formed on its inner periphery that is fastened to the external threaded portion; and an inner ring described in any one of (1) to (5).
[0025] The pipe fitting according to the present invention can achieve the same effect as the inner ring.
[0026] The effects of the invention
[0027] According to the present invention, the axial end of the inner circumferential surface of the inner ring can be effectively prevented from protruding into the fluid flow path. Attached Figure Description
[0028] Figure 1 This is an axial cross-sectional view of the pipe fitting according to an embodiment of the present invention.
[0029] Figure 2 This is a cross-sectional view showing the axial direction of the inner ring of the pipe fitting.
[0030] Figure 3 It represents the first conical surface of the inner circumferential surface of the inner ring. Figure 2 Enlarged cross-sectional view of the main part.
[0031] Figure 4 It represents the second conical surface of the inner circumferential surface of the inner ring. Figure 2 Enlarged cross-sectional view of the main part.
[0032] Figure 5 This is a cross-sectional view showing the current pipe fitting along its axial direction.
[0033] Figure 6 This is a cross-sectional view showing the current inner ring along its axial direction.
[0034] Figure 7 This is an enlarged cross-sectional view showing the current inner ring formed by the conical surface of the inner circumferential surface being shorter in the axial direction.
[0035] Figure 8 It means Figure 7 An enlarged cross-sectional view of the inner ring after its conical surface has been deformed.
[0036] Figure 9 This is an enlarged cross-sectional view showing the current inner ring formed by the conical surface of the inner circumferential surface being longer in the axial direction.
[0037] Figure 10 It means Figure 9 An enlarged cross-sectional view of the inner ring after its conical surface has been deformed. Detailed Implementation
[0038] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
[0039] [Overall structure of the pipe fitting]
[0040] Figure 1 This is an axial cross-sectional view showing the pipe fitting according to an embodiment of the present invention. Figure 1 In this embodiment, the pipe fitting 1 is used, for example, for piping paths of liquid (fluid) flow in semiconductor manufacturing equipment. The pipe fitting 1 has a fitting body 2, a connecting nut 3, and an inner ring 4. Hereinafter, for convenience, in this embodiment, [the following will be described]. Figure 1 The left side is called the axial side. Figure 1 The right side is called the other side of the axis (for) Figures 2-4 Same here).
[0041] The inner ring 4 is formed into a cylindrical shape, for example, from a synthetic resin material such as polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), or fluoropolymer (fluorocarbon (PFA), polytetrafluoroethylene (PTFE), or polyvinylidene fluoride (PVDF)).
[0042] A fluid flow path 4b is formed on the inner side of the inner circumferential surface 4a of the inner ring 4. The fluid flow path 4b connects the flow path 8a formed inside the pipe 8 with the flow path 2c formed inside the connector body 2. The inner ring 4 has: a bulge 5 formed at one axial end; a press-in portion 6 formed at the other axial end; and a cylindrical body portion 7 formed between the bulge 5 and the press-in portion 6.
[0043] The bulge 5 is pressed into the front end of the tube 8, which is made of synthetic resin material (PFA, etc.), thereby expanding the diameter of the front end of the tube 8. The bulge 5 has an outer peripheral surface 5a that protrudes radially outward and is formed in a mountain shape. The outer peripheral surface 5a of the bulge 5 has a maximum outer diameter portion 5b, a first diameter reduction portion 5c, and a second diameter reduction portion 5d, which is the maximum outer diameter.
[0044] The maximum outer diameter portion 5b is formed along a specified axial length L (refer to...). Figure 2 The first reduced-diameter portion 5c is formed to gradually reduce in diameter from one axial end of the largest outer diameter portion 5b toward one axial side. The second reduced-diameter portion 5d is formed to gradually reduce in diameter from the other axial end of the largest outer diameter portion 5b toward the other axial side. The other axial end of the second reduced-diameter portion 5d is connected to the outer peripheral surface 7a of the main body portion 7.
[0045] The press-in part 6 is pressed into the end (axial end) of the connector body 2. The press-in part 6 has a cylindrical press-in body 6a, an annular primary sealing part 6b, and a cylindrical secondary sealing part 6c.
[0046] The pressing body 6a is pressed into the socket portion 2a (described later) of the connector body 2.
[0047] The primary sealing portion 6b is formed to protrude radially inward from the other axial end of the press-in body 6a toward the other axial end. The outer peripheral surface 6b1 of the primary sealing portion 6b is formed to gradually narrow from one axial end toward the other axial end. The primary sealing portion 6b is pressed into the primary sealing groove 2d of the connector body 2 (described later).
[0048] The secondary sealing portion 6c is formed to protrude radially outward from the other end of the press-in body 6a along the axial direction. The secondary sealing portion 6c is pressed into the secondary sealing groove 2e (described later) of the connector body 2. An annular groove 6d with an arc-shaped cross-section is formed between the primary sealing portion 6b and the secondary sealing portion 6c. The outer diameter of the secondary sealing portion 6c is the same as the outer diameter of the press-in body 6a. Thus, the press-in portion 6 (press-in body 6a and secondary sealing portion 6c) has a constant outer diameter D3 (see reference) throughout the entire axial direction. Figure 2 ).
[0049] The main body 7 of the inner ring 4 has a constant outer diameter D1 throughout the entire axial direction. This outer diameter D1 is smaller than the maximum outer diameter D2 of the bulge 5 and smaller than the outer diameter D3 of the press-in part 6 (see reference). Figure 2 The outer peripheral surface 7a of the main body 7 is connected to the outer peripheral surface 6f of the press-in part 6 via a stepped surface 6e formed at one axial end of the press-in part 6.
[0050] The connector body 2 is formed into a cylindrical shape from a synthetic resin material such as PVC, PP, PE, or fluoropolymer (PFA, PTFE, etc.). The inner diameter of the connector body 2 is set to be approximately the same as the inner diameter of the inner ring 4 in a manner that does not impede the movement of the liquid. A cylindrical socket portion 2a is formed at one axial end of the connector body 2. The press-in portion 6 of the inner ring 4, which has a bulge 5, is pressed into the inner circumference of the socket portion 2a at the front end of the pipe 8. Thus, one axial end of the connector body 2 is mounted on the outer circumference of the front end of the pipe 8. An external thread portion 2b is formed on the outer circumference of the socket portion 2a.
[0051] The connector body 2 has an annular primary sealing groove 2d formed on the axial side further away than the socket portion 2a, and a cylindrical secondary sealing groove 2e. The primary sealing groove 2d is formed in a tapered shape on the radially inner side of the connector body 2, gradually narrowing from one axial end to the other. The secondary sealing groove 2e is formed on the radially outer side of the connector body 2, compared to the primary sealing groove 2d.
[0052] The connecting nut 3 is formed into a cylindrical shape, for example, from a synthetic resin material such as PVC, PP, PE, or fluoropolymer (PFA, PTFE, etc.). The connecting nut 3 has: a pressing portion 3a, which protrudes radially inward at one axial end; and an internal thread portion 3b, which is formed on the inner circumference at the other axial end. The internal thread portion 3b is fastened to the external thread portion 2b of the connector body 2. This fastening secures the connecting nut 3 to the connector body 2, and the other axial end of the pressing portion 3a presses against the outer circumferential surface of the tube 8, which bulges radially outward due to the bulge 5 of the inner ring 4.
[0053] Based on the above structure, if the internal thread 3b of the connecting nut 3 is tightened to the external thread 2b of the connector body 2, the primary sealing part 6b and the secondary sealing part 6c of the inner ring 4 are pressed into the primary sealing groove 2d and the secondary sealing groove 2e of the connector body 2, respectively, thus ensuring the sealing performance of the connection between the inner ring 4 and the connector body 2. Furthermore, the pressing part 3a of the connecting nut 3 can be used to prevent the tube 8 from being pulled out.
[0054] [Inner circumference of the inner ring]
[0055] Figure 2 This is a cross-sectional view showing the axial direction of the inner ring 4, indicating the state before the bulge 5 and the press-in part 6 are pressed into the front end of the tube 8 and the end of the connector body 2, respectively. Figure 2 As shown, the inner ring 4 has: a first conical surface 11 formed at one axial end of the inner circumferential surface 4a; and a second conical surface 12 formed at the other axial end of the inner circumferential surface 4a.
[0056] The first conical surface 11 is formed at one axial end of the inner circumferential surface 4a such that its diameter gradually increases from the other axial side toward one axial end. In this embodiment, the first conical surface 11 is formed, for example, a curved surface. Alternatively, the first conical surface 11 may be formed as a planar surface.
[0057] The second conical surface 12 is formed at the other axial end of the inner circumferential surface 4a such that its diameter gradually increases from one axial side toward the other axial end. In this embodiment, the second conical surface 12 is, for example, formed as a planar surface. Alternatively, the second conical surface 12 may be formed as a curved surface.
[0058] Figure 3 It represents the first conical surface 11 of the inner circumferential surface 4a of the inner ring 4. Figure 2 Enlarged cross-sectional view of the main part. Figure 3 Preferably, the expansion starting point P11 of the first conical surface 11 is located within a range R11 from the deformation starting point position P12 of the inner circumferential surface 4a to the position P13 of the inner circumferential surface 4a corresponding to one axial end of the outer circumferential surface 7a of the main body 7. Here, "the range R11 from the deformation starting point position P12 to ... position P13" means that it also includes the deformation starting point position P12 and the position P13.
[0059] The deformation starting point position P12 is the position where deformation begins when the bulge 5 is pressed into the front end of the tube 8 and when the connecting nut 3 (internal thread portion 3b) is tightened to the connector body 2 (external thread portion 2b), and the bulge 5 is subjected to external force from the tube 8 and the connecting nut 3, causing the axial end of the inner circumferential surface 4a of the inner ring 4 to be bent radially inward. Therefore, at the axial end of the inner circumferential surface 4a of the inner ring 4, the portion further axial than the deformation starting point position P12 deforms by bending radially inward. In this embodiment, the deformation starting point position P12 is the position of the inner circumferential surface 4a corresponding to the axial end of the maximum outer diameter portion 5b of the outer circumferential surface 5a of the bulge 5.
[0060] The expansion starting point P11 of the first conical surface 11 is located within the range R11, thus achieving the following effects.
[0061] The expansion start point P11 of the first conical surface 11 will not be located on the axial side more than the deformation start point P12. As a result, the radial inward deformation of the expansion start point P11 of the first conical surface 11 due to the external forces from the tube 8 and the connecting nut 3 can be suppressed, thus ensuring the radial inward deformation margin of the axial end of the inner circumferential surface 4a of the inner ring 4.
[0062] Furthermore, the expansion starting point P11 of the first conical surface 11 will not be located on the other side of the axial direction than position P13. That is, the expansion starting point P11 of the first conical surface 11 will not be located in the radially thinned portion of the inner ring 4. Thus, even when the first conical surface 11 is formed, excessive reduction in the radial thickness (cross-sectional area) of the axial end of the inner ring 4 can be suppressed, thereby suppressing the degree of radial inward deformation of the axial end of the inner circumferential surface 4a of the inner ring 4.
[0063] Therefore, the expansion starting point P11 of the first conical surface 11 is located within the range R11, which can effectively suppress the axial end of the inner circumferential surface 4a of the inner ring 4 from protruding into the fluid flow path 4b.
[0064] More preferably, the expansion starting point P11 of the first conical surface 11 is located within the range R12 of the inner circumferential surface 4a, which corresponds to the range L of the length of the maximum outer diameter portion 5b of the outer circumferential surface 5a of the bulge portion 5. In this case, the expansion starting point P11 of the first conical surface 11 is located at the portion with the greatest radial thickness of the bulge portion 5, so even if the first conical surface 11 is formed, the degree of radial thickness reduction at one axial end of the inner ring 4 can be suppressed. As a result, the degree of radial inward deformation of one axial end of the inner circumferential surface 4a of the inner ring 4 can be further suppressed.
[0065] In this embodiment, the expansion starting point P11 of the first conical surface 11 is located at the deformation starting point position P12 within the range R12. In this case, it is possible to suppress the radial inward deformation of the expansion starting point P11 of the first conical surface 11 due to the external force, and to minimize the degree of radial thickness reduction at one axial end of the inner ring 4. As a result, it is possible to further suppress the degree of radial inward deformation of one axial end of the inner circumferential surface 4a of the inner ring 4.
[0066] like Figure 1 As shown, when the bulge 5 is pressed into the front end of the tube 8, and an external force is generated due to the tightening of the connecting nut 3, the first conical surface 11 of this embodiment deforms in such a way that the entire first conical surface 11 is poured inward, thereby becoming a state in which it extends straight in the axial direction along the inner circumferential surface 4a. Therefore, when the bulge 5 is pressed into the front end of the tube 8, even if a portion of the axial direction of the inner circumferential surface 4a of the inner ring 4 is deformed in a way that is poured inward, it will not bulge into the fluid flow path 4b.
[0067] Figure 4 This refers to the second conical surface 12 of the inner circumferential surface 4a of the inner ring 4. Figure 2 Enlarged cross-sectional view of the main part. Figure 4 Preferably, the expansion starting point P21 of the second conical surface 12 is located within a range R21 from the deformation starting point position P22 of the inner circumferential surface 4a to the position P23 of the inner circumferential surface 4a corresponding to the other axial end of the outer circumferential surface 7a of the main body 7. Here, "the range R21 from the deformation starting point position P22 to ... position P23" means that it also includes the deformation starting point position P22 and the position P23.
[0068] The deformation starting point P22 is such that, when the press-in part 6 is pressed into the end of the connector body 2, especially when the primary sealing part 6b is pressed into the primary sealing groove 2d, it becomes the starting point for the deformation of the primary sealing part 6b of the press-in part 6, which is subjected to external force from the connector body 2, causing the other axial end of the inner circumferential surface 4a of the inner ring 4 to be pushed radially inward. Therefore, at the other axial end of the inner circumferential surface 4a of the inner ring 4, the portion further axially than the deformation starting point P22 deforms in a way that pushes radially inward.
[0069] The expansion starting point P21 of the second conical surface 12 is located within the range R21, thus achieving the following effects.
[0070] The expansion starting point P21 of the second conical surface 12 will not be located on the other side of the axial direction than the deformation starting point P22. As a result, the expansion starting point P21 of the second conical surface 12 can be suppressed from deforming radially inward due to the external force from the joint body 2, thus ensuring the radially inward deformation margin of the other end of the inner circumferential surface 4a of the inner ring 4.
[0071] Furthermore, the expansion starting point P21 of the second conical surface 12 is not located further axially than the position P23 of the inner circumferential surface 4a corresponding to the other axial end of the outer circumferential surface 7a of the main body 7. That is, the expansion starting point P21 of the second conical surface 12 is not located in the portion where the radial thickness of the inner ring 4 is reduced. Thus, even when the second conical surface 12 is formed, excessive reduction in the radial thickness (cross-sectional area) of the other axial end of the inner ring 4 can be suppressed, thereby suppressing the degree of radial inward deformation of the other axial end of the inner circumferential surface 4a of the inner ring 4.
[0072] Therefore, the expansion starting point P21 of the second conical surface 12 is located within the range R21, thereby effectively suppressing the axial other end of the inner circumferential surface 4a of the inner ring 4 from protruding into the fluid flow path 4b.
[0073] In this embodiment, the deformation starting point P22 is located at the intersection of the tangent to the annular groove 6d and the radially extending virtual tangent K with the inner circumferential surface 4a. Furthermore, the expansion starting point P21 of the second conical surface 12 in this embodiment is located at the deformation starting point P22 within the range R21. In this case, the radial inward deformation of the expansion starting point P21 of the second conical surface 12 due to the external force can be suppressed, and the degree of radial thickness reduction at the other axial end of the inner ring 4 can be minimized. Therefore, the degree of radial inward deformation at the other axial end of the inner circumferential surface 4a of the inner ring 4 can be further suppressed.
[0074] like Figure 1 As shown, when the press-in portion 6 is pressed into the end of the connector body 2, the second conical surface 12 of this embodiment deforms in such a way that the entire second conical surface 12 is poured inward, thereby becoming a state in which it extends straight in the axial direction along the inner circumferential surface 4a. Therefore, when the press-in portion 6 is pressed into the end of the connector body 2, even if the other axial end of the inner circumferential surface 4a of the inner ring 4 deforms in such a way that it is poured inward, it will not bulge into the fluid flow path 4b.
[0075] [other]
[0076] In the above embodiment, the maximum outer diameter portion 5b of the outer peripheral surface 5a of the bulge 5 is formed over a predetermined axial length L, but it may also be formed only at a single point in the axial direction. Furthermore, the press-in portion 6 in the above embodiment has a press-in body 6a, a primary sealing portion 6b, and a secondary sealing portion 6c, but at least a primary sealing portion 6b is sufficient. Additionally, the pipe connector 1 and inner ring 4 of the present invention can be applied not only to semiconductor manufacturing apparatuses but also to liquid crystal / organic EL fields, medical / pharmaceutical fields, or automotive-related fields. Furthermore, either the first conical surface 11 on the side of the bulge 5 or the second conical surface 12 on the side of the press-in portion 6 may be used on the inner ring 4.
[0077] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is not indicated by the foregoing but by the claims, and its essence is to include the equivalent scope of the claims and all modifications within that scope.
[0078] Explanation of the label
[0079] 1. Pipe fitting
[0080] 2. Connector body
[0081] 2d primary sealing groove
[0082] 2e Secondary sealing groove
[0083] 3. Connecting nut
[0084] 4 Inner Ring
[0085] 4a Inner circumferential surface
[0086] 4b Fluid flow path
[0087] 5. Drum section
[0088] 5a Outer Peripheral Surface
[0089] 5b Maximum outer diameter section
[0090] 6. Pressing section
[0091] 7 Main body
[0092] 7a Outer peripheral surface
[0093] 8 tubes
[0094] 11. First cone surface (cone surface)
[0095] 12. Second cone surface (cone surface)
[0096] P11, P21 Enlargement start point
[0097] P12, P22 Deformation starting point positions
[0098] Position of the inner circumferential surfaces of P13 and P23
Claims
1. An inner ring having: The bulge is formed by protruding radially outward from one axial end and is pressed into the front end of the tube. A press-in portion, formed at the other axial end, is press-in into the end of the connector body; and A cylindrical main body, formed between the bulge and the press-in portion, has a constant outer diameter throughout the entire axial direction, which is smaller than the maximum outer diameter of the bulge. A fluid flow path is formed on the inner side of the inner circumferential surface, wherein, Before the bulge is pressed into the front end of the tube, the inner circumferential surface has a tapered surface at one axial end that gradually expands in diameter from the other axial side toward that axial end. On the outer peripheral surface of the bulge, a maximum outer diameter portion with a constant maximum outer diameter is formed throughout a predetermined length along the axial direction. The deformation starting point position, which is the starting point of the deformation of the inner circumferential surface caused by the external force exerted on the bulge by the tube when the bulge is pressed into the front end of the tube, is located on the inner circumferential surface corresponding to one axial end of the maximum outer diameter portion. The starting point of the diameter expansion of the conical surface is located within the range from the deformation starting point to the position of the inner circumferential surface corresponding to one axial end of the outer circumferential surface of the main body.
2. The inner ring according to claim 1, wherein, The starting point of the diameter expansion of the conical surface is located within the range of the inner circumferential surface corresponding to the range of the specified length of the maximum outer diameter portion.
3. The inner ring according to claim 2, wherein, The expansion starting point of the conical surface is located at the deformation starting point position.
4. An inner ring having: The bulge is formed by protruding radially outward from one axial end and is pressed into the front end of the tube. A press-in portion, formed at the other axial end, is press-in into the end of the connector body; and A cylindrical main body, formed between the bulge and the press-in portion, has a constant outer diameter throughout the entire axial direction, which is smaller than the outer diameter of the press-in portion. A fluid flow path is formed on the inner side of the inner circumferential surface, wherein, Before the press-in portion is pressed into the end of the connector body, the other axial end of the inner circumferential surface has a tapered surface that gradually expands in diameter from one axial side toward the other axial end. The press-in portion has a primary sealing portion and a secondary sealing portion disposed radially outside the primary sealing portion. An annular groove with an arc-shaped cross-section is formed between the primary sealing part and the secondary sealing part. The deformation starting point, which is the point at which the inner circumferential surface deforms due to external force applied to the press-in portion when it is pressed into the end of the connector body, is located at the intersection of the tangent of the annular groove and the virtual tangent extending radially along the inner circumferential surface with the inner circumferential surface. The starting point of the diameter expansion of the conical surface is located within the range from the starting point of the deformation to the position of the inner circumferential surface corresponding to the other axial end of the outer circumferential surface of the main body.
5. The inner ring according to claim 4, wherein, The expansion starting point of the conical surface is located at the deformation starting point position.
6. A pipe fitting, wherein, The pipe fitting has the following features: The connector body has an external threaded portion formed on its outer periphery; A connecting nut having an internally threaded portion on its inner circumference that is fastened to the externally threaded portion; and The inner ring according to any one of claims 1 to 5.