Fittings

Abstract

To provide a joint fitting capable of transporting a metal seal surface without any damage.SOLUTION: A joint fitting 10A comprises a device connection part 16. The device connection part 16 comprises a pipe end part 24 connected to the end part of a straight part 20 and having a metal seal surface M1, and a union nut 26 rotatably connected to the straight part 20 so as not to be removed from the pipe end part 24. In the joint fitting 10A, the inner peripheral part of the union nut 26 and the outer peripheral part of the pipe end part 24 are provided with uneven coupling parts 28 that engage with each other, prevent movement of the union nut 26 in a direction of the straight part, and maintain a state in which the union nut 26 covers the metal seal surface M1. The uneven coupling portion 28 is composed of a portion 2404A of the metal seal surface M1 near a large diameter part 2402, and an annular convex part 2604A that protrudes from the entire circumference of the inner peripheral part of a trunk part 2604 and engages with the metal seal surface M1 near the large diameter part 2402.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a joint fitting.

Background Art

[0002] Conventionally, as a joint fitting for connecting a pipe to equipment or the like, for example, a hose joint fitting having a metal seal surface has been provided. The hose joint fitting having a metal seal surface includes a hose connection portion provided on one side in the longitudinal direction of the pipe portion to which a hose is connected, and an equipment connection portion provided on the other side in the longitudinal direction of the pipe portion and connected to the equipment side. The equipment connection portion includes a straight portion where the pipe portion extends linearly, a pipe end portion connected to the end of this straight portion and having a metal seal surface, and a union nut that covers the pipe end portion including the metal seal surface. The union nut is rotatably coupled to the straight portion and is coupled so as not to fall off from the pipe end portion in a direction away from the straight portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, although the union nut is provided so as not to fall off from the pipe end portion, it is provided so as to be movable in the direction of the straight portion. Therefore, when such a joint fitting is shipped from the factory, due to vibrations during transportation, the union nut moves in a direction away from the metal seal surface, causing the metal seal surface to be exposed to the outside, and it is conceivable that the metal seal surface is damaged when another joint fitting hits the metal seal surface. If the metal seal surface is damaged, when using fittings in piping, it may not be possible to create an airtight and liquid-tight connection with the mating metal seal surface, meaning the metal seal will not be reliably formed, which may cause fluid leakage. The present invention has been made in view of the above circumstances, and the object of the present invention is to provide a joint fitting that includes a union nut provided so as to cover a metal seal surface, and that can be transported without damaging the metal seal surface. [Means for solving the problem]

[0005] To achieve the above-mentioned objective, one embodiment of the present invention comprises a pipe portion and a union nut, wherein one longitudinal side of the pipe portion comprises a linear portion extending in a straight line and a pipe end connected to the end of the linear portion and having a metal sealing surface, and the union nut is a fitting that is rotatably connected to the linear portion and cannot be detached from the pipe end in the direction away from the linear portion, characterized in that the inner circumference of the union nut and the outer circumference of the pipe end are provided with a concave and concave coupling portion that locks with each other, prevents the union nut from moving in the direction of the linear portion, and maintains a state in which the union nut covers the metal sealing surface. Furthermore, in one embodiment of the present invention, the outer circumference of the pipe end is formed of a large-diameter portion connected to the end of the straight portion and having an outer diameter larger than the outer diameter of the straight portion, and an inclined surface connected to the outer circumference of the large-diameter portion and having an outer diameter that gradually decreases as it moves away from the large-diameter portion, constituting the metal seal surface, and the union nut comprises a small-diameter portion rotatably connected to the straight portion and having an inner diameter smaller than that of the large-diameter portion, a body portion protruding from the small-diameter portion, and a female thread portion protruding from the end of the body portion located opposite the small-diameter portion, and the concave-convex coupling portion is characterized by comprising the portion of the metal seal surface near the large-diameter portion and a convex portion protruding from the inner circumference of the body portion and engaging with the portion of the metal seal surface. Furthermore, in one embodiment of the present invention, the outer circumference of the pipe end is formed by a large-diameter portion with an outer diameter larger than the outer diameter of the straight portion and connected to the end of the straight portion, the metal seal surface is formed by an inclined surface provided on the inner circumference of the large-diameter portion and whose inner diameter gradually increases as it moves away from the tip of the large-diameter portion, the union nut comprises a small-diameter portion rotatably connected to the straight portion and having an inner diameter smaller than that of the large-diameter portion, a body portion protruding from the small-diameter portion, and a female thread portion protruding from the end of the body portion located opposite the small-diameter portion, and the concave-convex coupling portion is characterized by comprising a concave or convex portion provided on the outer circumference of the large-diameter portion and a convex or concave portion provided on the inner circumference of the body portion and engaging with the concave or convex portion. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the uneven joint prevents the union nut from moving in the direction of the straight section, maintaining the state in which the union nut covers the metal seal surface, and preventing the metal seal surface from being exposed to the outside. Therefore, vibrations during transport cause the union nut to move away from the metal seal surface, exposing the metal seal surface to the outside. This prevents other fittings from coming into contact with the metal seal surface, which is advantageous in preventing damage to the metal seal surface during transport and in preventing fluid leakage from fittings with a metal seal surface. Furthermore, the interlocking joints are concealed by union nuts and are not visible from the outside, thus maintaining the aesthetic appearance of the fittings while preventing damage to the metal seal surface, which is advantageous in increasing the sales volume of the fittings. [Brief explanation of the drawing]

[0007] [Figure 1] This is a cross-sectional view of the joint fitting according to the first embodiment. [Figure 2] This is an enlarged cross-sectional view of the pipe end, union nut, and interlocking joint portion of the fitting in the first embodiment. [Figure 3] This is an enlarged cross-sectional view of the pipe end and the union nut portion of the joint fitting of the first embodiment before crimping the body. [Figure 4] This is a cross-sectional view of the pipe section having the metal seal surface of the other party. [Figure 5] This is a cross-sectional view showing the joint fitting and the pipe portion on the equipment side of the first embodiment joined together with a metal seal. [Figure 6] This is an enlarged cross-sectional view of the portion where the joint fitting and the pipe section on the equipment side of the first embodiment are joined by a metal seal. [Figure 7] This is a cross-sectional view of the joint fitting according to the second embodiment. [Figure 8] This is an enlarged cross-sectional view of the pipe end, union nut, and interlocking portion of the joint fitting in the second embodiment. [Figure 9] This is an enlarged cross-sectional view of the pipe end and the union nut portion of the joint fitting of the second embodiment before crimping the body. [Figure 10] This is a cross-sectional view of the pipe section having the metal seal surface of the other party. [Figure 11] This is a cross-sectional view showing the joint fitting and the pipe portion on the equipment side of the second embodiment joined together with a metal seal. [Figure 12] This is an enlarged cross-sectional view of the portion where the joint fitting and the pipe section on the equipment side of the second embodiment are joined by a metal seal. [Modes for carrying out the invention]

[0008] Hereinafter, a joint fitting according to an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) The first embodiment will be described with reference to Figures 1 to 6. As shown in Figure 1, the fitting 10A is a hose fitting used to connect a hose to equipment, and is a so-called elbow nipple with a bend, and is made of metal. The fitting 10A comprises a pipe section 12, a hose connection section 14 provided on one side of the pipe section 12 in the longitudinal direction, and an equipment connection section 16 provided on the other side of the pipe section 12 in the longitudinal direction. The pipe section 12 comprises a bent section 18 and a straight section 20 that extends linearly from the bent section 18. The hose connection part 14 includes a nipple 22 having a large-diameter part 2202 on the nipple side following the end of the bend part 18, a recessed part 2204, and a hose insertion part 2206, and a socket (not shown) attached to the recessed part 2204 and arranged outside the hose insertion part 2206.

[0009] The equipment connection part 16 includes a pipe end part 24 connected to the end of the straight part 20 and having a metal seal surface M1 (male-type metal seal surface), and a union nut 26 rotatably coupled to the straight part 20 and inseparably joined to the pipe end part 24. A flow path C is formed in the inner circumferential parts of the nipple 22, the pipe part 12, and the pipe end part 24. The joint fitting 10A is manufactured by separately making the hose insertion part 22 in relation to the pipe part 12 and the equipment connection part 16. Initially, the bend part 18 extends on the same straight line as the straight part 20. After attaching the union nut 26 to the pipe end part 24, the end of the pipe part 12 extending linearly and the end of the nipple 22 are joined by friction pressure welding, and then the bend part 18 is formed by bending to manufacture the joint fitting 10A.

[0010] The joint fitting 10A is provided with a concavo-convex coupling part 28 that locks to the inner circumferential part of the union nut 26 and the outer circumferential part of the pipe end part 24, prevents the movement of the union nut 26 in the direction of the straight part 20, and holds the state of covering the metal seal surface M1 with the union nut 26. Specifically, as shown in FIG. 2, the outer circumferential part of the pipe end part 24 is connected to the end of the straight part 20 and has a large-diameter part 2402 with an outer diameter larger than the outer diameter of the straight part 20, and is formed by an inclined surface 2404 whose outer diameter gradually decreases as it moves away from the large-diameter part 240, and this inclined surface 2404 constitutes the metal seal surface M1. The union nut 26 includes a small-diameter part 260 having an inner diameter smaller than the large-diameter part 2402 and rotatably coupled to the straight part 20, a body part 2604 protruding from the small-diameter part 2602, and a female thread part 2606 protruding from the end of the body part 2604 located opposite to the small-diameter part 2602. The union nut 26 is configured such that the small-diameter portion 2602 is locked to the large-diameter portion 2402 to prevent the union nut 26 from falling off the pipe end portion 24. In a state where the small-diameter portion 2602 is locked to the large-diameter portion 2402, the body portion 2604 is located radially outside the large-diameter portion 2402 and the metal seal surface M1 and covers the metal seal surface M1. The concavo-convex coupling portion 28 is formed by an annular convex portion 2604A that protrudes from the entire circumference of a location on the inner peripheral portion of the body portion 2604 located in the middle in the axial direction of the body portion 2604 and the location 2404A of the metal seal surface M1 near the large-diameter portion 2402, and is locked to the inclined surface 2404 near the large-diameter portion 2402 at the location 2404A.

[0011] In a state where the pipe portion 12 and the equipment connection portion 16 are formed separately from the hose insertion portion 2206, the inner diameter of the convex portion 2604A is formed to be larger than the outer diameter of the large-diameter portion 2402, as shown in FIG. 3, so that the union nut 26 can be attached from the pipe portion 12 to the pipe end portion 24 in a state where the bend portion 18 extends on the same straight line as the straight portion 20. That is, in a state where the small-diameter portion 2602 is locked to the large-diameter portion 2402, the body portion 2604 including the convex portion 2604A is formed to be located radially outside the large-diameter portion 2402. Then, in a state where the small-diameter portion 2602 is locked to the large-diameter portion 2402, the body portion 2604 is clamped by a dedicated clamping device, and as shown in FIG. 2, the convex portion 2604A is displaced radially inward. By clamping the body portion 2604, the convex portion 2604A can be locked to the location 2404A of the inclined surface 2404 near the large-diameter portion 2402. When the convex portion 2604A is locked to the location 2404A of the inclined surface 2404 near the large-diameter portion 2402, the movement of the union nut 26 in the direction of the straight portion 20 is blocked, and the state in which the metal seal surface M1 is covered by the body portion 2604 is maintained, or the state in which the metal seal surface M1 is covered by the body portion 2604 and the female screw portion 2606 is maintained.

[0012] As shown in FIG. 4, the connection of the equipment connection portion 16 to the mating side is performed with respect to a pipe body 30 having a flow path C provided in the inner peripheral portion and having a metal seal surface M2 (female-type metal seal surface) and a male screw portion 3002. The metal sealing surface M2 is provided on the inner circumference of the male thread portion 3002 and is formed by an inclined surface 3004 whose inner diameter gradually decreases as it moves away from the tip of the male thread portion 3002. Then, the male threaded portion 3002 of the pipe body 30 is screwed into the female threaded portion 2606 of the union nut 26, and the union nut 26 is rotated. As a result, the pipe body 30 moves into the union nut 26, and eventually the metal sealing surfaces M1 and M2 are pressed together, creating a metal seal through metal-to-metal contact. As shown in Figures 5 and 6, the pipe end 24 and the pipe body 30 are fastened in a sealed state. Furthermore, the metal seal surface M1 of the pipe end 24 and the metal seal surface M2 of the pipe body 30 are formed according to JIS standards, and the tip of the metal seal surface M1 of the pipe end 24 and the base of the metal seal surface M2 of the pipe body 30 are metal-sealed.

[0013] According to this embodiment, when the joint fitting 10A is shipped from the factory, as shown in Figures 1 and 2, the protrusion 2604A can be locked onto the metal seal surface M1 at location 2404A near the large diameter portion 2402, thereby preventing the union nut 26 from moving in the direction of the straight portion 20. In other words, because it is equipped with a recessed joint portion 28, the union nut 26 maintains a state in which the metal seal surface M1 is covered, and the metal seal surface M1 is not exposed to the outside. Therefore, vibrations during transport cause the union nut 26 to move away from the metal seal surface M1, exposing the metal seal surface M1 to the outside. This prevents other fittings from coming into contact with the metal seal surface M1, which is advantageous in preventing damage to the metal seal surface M1 during transport and in preventing fluid leakage from the fitting 10A having the metal seal surface M1. Furthermore, the interlocking joint 28 is concealed by the union nut 26 and cannot be seen from the outside. Therefore, it is possible to prevent damage to the metal seal surface M1 while maintaining the appearance of the fitting 10A, which is advantageous in increasing the sales volume of the fitting 10A.

[0014] The configuration of the interlocking joint 28 is not limited to the structure of the above embodiment. For example, it may be configured by providing a recess around the entire circumference of the outer periphery of the large-diameter portion 2402 of the pipe end 24 and a protrusion that can engage with the recess around the entire circumference of the inner periphery of the body portion 2604, or by providing a protrusion around the entire circumference of the outer periphery of the large-diameter portion 2402 of the pipe end 24 and a recess that can engage with the protrusion around the entire circumference of the inner periphery of the body portion 2604. Various conventionally known structures can be adopted, but a structure like that of the embodiment simplifies the structure and is advantageous for easily and reliably manufacturing the interlocking joint 28.

[0015] (Second Embodiment) A second embodiment will be described with reference to Figures 7 to 12. In the description of the second embodiment, the same parts and components as in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. The description will focus on the parts that differ from the first embodiment. In the second embodiment, the metal seal surface M3 provided at the pipe end 34 is formed on the inner circumference of the large-diameter portion 3402, and the structure of the uneven joint portion 38 differs from that of the first embodiment.

[0016] In other words, as shown in Figure 7, the fitting 10B is a hose fitting similar to the first embodiment, and the fitting 10B comprises a pipe section 12 having a bent section 18 and a straight section 20, a hose connecting section 14 having a nipple 22 and a socket (not shown), and an equipment connecting section 16. The equipment connection section 16 includes a pipe end 34 having a metal sealing surface M3 (female metal sealing surface) and a union nut 26. A flow path C is formed in the inner circumference of the nipple 22, the bend 18, the straight section 20, and the pipe end 34. The manufacturing of such a fitting 10B is similar to that of the first embodiment, in which the hose insertion portion 2206 is made separately from the pipe portion 12 and the equipment connection portion 16, the union nut 26 is attached to the pipe end 34, the end of the linearly extending pipe portion 12 and the end of the hose insertion portion 2206 are joined by friction welding, and then the bend portion 18 is made by bending to manufacture the fitting 10B.

[0017] As shown in Figure 8, the outer circumference of the pipe end 34 is connected to the end of the straight section 20 and is formed by a large-diameter section 3402 with a uniform outer diameter larger than the outer diameter of the straight section 20. The metal sealing surface M3 is provided on the inner circumference of the large-diameter portion 3402 and is formed by an inclined surface 3404 whose inner diameter gradually increases as it moves away from the tip of the large-diameter portion 3402. A recess 3406 is provided on the outer circumference of the large diameter portion 3402, located in the axial middle portion of the large diameter portion 3402, and extending around the entire circumference of the outer circumference. The union nut 26 is rotatably connected to the straight section 20 and comprises a small-diameter section 2602 having an inner diameter smaller than that of the large-diameter section 3402, a body section 2604 protruding from the small-diameter section 2602, and a female threaded section 2606 protruding from the end of the body section 2604 located opposite the small-diameter section 2602. An annular projection 2604A is provided around the entire circumference of the inner circumference portion located in the axial middle of the body portion 2604, which engages with the recess 3406 of the large diameter portion 3402. In the second embodiment, the concave-concave coupling portion 38, which prevents the union nut 26 from moving in the direction of the straight portion 20 and maintains the state in which the union nut 26 covers the metal seal surface M3, is composed of a concave portion 3406 provided in the large diameter portion 3402 and a convex portion 2604A provided on the inner circumference of the body portion 2604 of the union nut 26.

[0018] In the second embodiment, as in the first embodiment, the pipe section 12 and the equipment connection section 16 are manufactured separately from the hose insertion section 2206. The inner diameter of the protrusion 2604A is formed to be larger than the outer diameter of the large-diameter section 3402, as shown in Figure 9. The bend section 18 extends along the same straight line as the straight section 20, and the union nut 26 is formed to be attached from the pipe section 12 to the pipe end 34. In other words, with the small-diameter portion 2602 locked to the large-diameter portion 3402, the body portion 2604, including the protrusion 2604A, is formed to be located radially outward from the large-diameter portion 3402. Then, with the small-diameter portion 2602 locked to the large-diameter portion 3402, the body portion 2604 is crimped using a dedicated crimping device, and the protrusion 2604A is displaced radially inward, as shown in Figure 8. The crimping of the body portion 2604 allows the protrusion 2604A to be locked into the recess 3406, preventing the union nut 26 from moving in the direction of the straight portion 20, and maintaining the state in which the union nut 26 covers the metal seal surface M3.

[0019] The connection of the equipment connection part 16 to the other side is performed on a pipe body 40 which has a flow path C on its inner circumference and a metal seal surface M4 (male metal seal surface) and a male threaded portion 4002, as shown in Figure 10. The metal seal surface M4 is provided on the outer circumference of the tip of the pipe body 40 and is formed by an inclined surface 4004 whose outer diameter gradually increases as it moves away from the tip of the pipe body 40. Then, insert the metal seal surface M4 into the female thread portion 2606 of the union nut 26, screw the male thread portion 4002 of the pipe body 40 into the female thread portion 2606 of the union nut 26, and rotate the union nut 26. As a result, the pipe body 40 advances into the union nut 26, and eventually the metal sealing surfaces M3 and M4 are pressed together, creating a metal seal through metal-to-metal contact. As shown in Figures 11 and 12, the pipe end 34 and the pipe body 40 are fastened in a sealed state. Furthermore, the metal seal surface M3 of the pipe end 34 and the metal seal surface M4 of the pipe body 40 are formed according to JIS standards, and the base of the metal seal surface M3 of the pipe end 34 and the tip of the metal seal surface M4 of the pipe body 40 are metal-sealed.

[0020] The joint fitting 10B of this second embodiment also provides the same effects as the first embodiment. The configuration of the interlocking joint 38 is not limited to the structure of the above embodiment. For example, it may be configured by providing a protrusion around the entire circumference of the outer circumference of the large-diameter portion 3402 of the pipe end 34, and providing a recess that can engage with the protrusion around the entire circumference of the inner circumference of the body portion 2604. Various conventionally known structures can be adopted.

[0021] Furthermore, while the first and second embodiments described the case where the fittings 10A and 10B are elbow nipples, the fittings 10A and 10B of the present invention can of course also be applied to straight nipples. Furthermore, the fittings 10A and 10B of the present invention are not limited to hose fittings, and are broadly applicable to fittings in which at least one side of the pipe section in the longitudinal direction comprises a linear section extending in a straight line and a pipe end connected to the end of this linear section and having a metal sealing surface, and a union nut is provided at the pipe end, and the structure of the other side in the longitudinal direction of the pipe section is not limited. [Explanation of Symbols]

[0022] 10A, 10B fittings 12 Pipe section 14. Hose connection 16 Equipment connection section 18 Bend section 20 Straight section 22 Nipples 2202 Nipple side large diameter section 2204 recess 2206 Hose insertion part 24, 34 Pipe end 2402, 3402 Large diameter section 2404, 3404 Slope 26 Union nuts 2602 Small diameter section 2604 Torso 2604A protrusion 2606 Female thread section 28, 38 Concave / convex joint 30, 40 tubular body 3002, 4002 Male thread section 3004, 4004 Slope 3406 Recess M1, M2, M3, M4 metal seal surface

Claims

1. It consists of a pipe section and a union nut, One side of the aforementioned pipe section in the longitudinal direction comprises a straight section extending in a straight line and a pipe end connected to the end of the straight section. The pipe end has a large-diameter portion with an outer diameter larger than the outer diameter of the straight portion, and an inclined portion connected to the large-diameter portion. A metal sealing surface is formed on the outer periphery of the inclined portion, which consists of an inclined surface whose outer diameter gradually decreases as it moves away from the large-diameter portion. The union nut has a body portion located radially outward from the end of the pipe and a female threaded portion connected to the body portion. The union nut is a fitting that is rotatably connected to the straight portion and cannot be removed from the pipe end in the direction away from the straight portion, An annular projection is provided that extends radially inward from the entire circumference of the inner circumference of the body, engages with the metal seal surface near the large diameter portion, and prevents the union nut from moving in the direction of the straight portion. A fitting characterized by the following.

2. The union nut has a nut opening at the end of the female thread portion located opposite to the body portion. With the annular protrusion engaged with the metal seal surface near the large diameter portion, the tip of the metal seal surface located opposite the large diameter portion and the end of the female thread portion away from the nut opening are located at approximately the same location in the axial direction of the pipe end. The fitting described in claim 1.

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