Joint

Abstract

To make a joint body hard to break.SOLUTION: The joint 10 includes a nut 12 having an abutting part 18 inside, and a joint body 14 having a flange part 22 abutting on the abutting part 18 and prevented from coming off from the nut 12 by abutment of the abutting part 18 and the flange part 22. In the joint body 14, an abutting surface 23 abutting on the abutting part 18 in the flange part 22 is formed into a curved surface. The joint 10 is configured to connect a first pipe 50 and a second pipe 52 by attaching the first pipe 50 to the nut 12 and attaching the second pipe 52 to the joint body 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint. [Background technology]

[0002] There is a type of joint called a union joint, in which a pipe member having a flange at its rear end is passed through a nut to connect a pipe such as a hose to the front end of the pipe member that protrudes from the nut (see, for example, Patent Document 1). The nut has an internal abutment surface against which the flange of the pipe member abuts, and the abutment of the flange and the abutment surface prevents the pipe member from coming off the nut. In such joints, when the nut with the pipe member placed on it is fastened to another pipe member, the flange is sandwiched between the other pipe member and the abutment surface, and the pipe member is fixed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-121074 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned joint, the load applied to the front end of the pipe member is concentrated on the flange, so there is a demand for improving the strength of the rear end of the pipe member.

[0005] The present invention has been proposed in view of the above-mentioned problems associated with the conventional technology in order to preferably solve these problems, and has an object to provide a joint in which the joint body is less likely to break. [Means for solving the problem]

[0006] A first aspect of the joint according to the present invention is a nut having an abutment portion therein; a joint body having a flange portion that abuts against the abutment portion and that is prevented from coming off the nut by the abutment between the abutment portion and the flange portion, The flange portion has a contact surface that contacts the contact portion and is curved.

[0007] A second aspect of the joint according to the present invention is the joint according to the first aspect, The contact surface of the contact portion that contacts the flange portion may be a curved surface.

[0008] A third aspect of the joint according to the present invention is the joint according to the first or second aspect, The contact surface may be formed of a single curved surface.

[0009] A fourth aspect of the joint according to the present invention is any one of the first aspect, the second aspect, and the third aspect, The nut may have two or more protrusions spaced apart in the circumferential direction on its circular outer periphery.

[0010] A fifth aspect of the joint according to the present invention is any one of the first aspect, the second aspect, the third aspect, and the fourth aspect, The nut and / or the joint body may be made of resin. [Effects of the Invention]

[0011] According to the joint of the present invention, the joint body is less likely to be damaged. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view of a joint according to an embodiment of the present invention, with a fastener attached; [Figure 2] FIG. 2 is an exploded cross-sectional view of the joint according to the embodiment. [Figure 3] 1 is a side view of an embodiment of a joint with a fastener attached. [Figure 4]FIG. 2 is a side view showing the joint of the embodiment. [Figure 5] FIG. 10 is a rear view showing the nut from the insertion side of the second pipe. [Figure 6] 2 is a cross-sectional view showing a state in which the nut of FIG. 1 is combined with another joint body that is compatible with a first pipe having a larger diameter than the joint body of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Next, a joint according to the present invention will be described below by way of preferred embodiments with reference to the accompanying drawings. Note that the embodiments and drawings described below exemplify a portion of the embodiments of the present invention, and are not intended to be used for the purpose of limiting the present invention to these configurations, and can be modified as appropriate within the scope of the gist of the present invention.

[0014] As shown in Figures 1, 2, and 4, a joint 10 according to this embodiment is a so-called union joint that connects two pipes (a first pipe 50 and a second pipe 52). The joint 10 includes a nut 12 and a joint body 14 that is combined with the nut 12. The joint 10 connects the first pipe 50 and the second pipe 52 by attaching the first pipe 50 to the nut 12 and attaching the second pipe 52 to the joint body 14. Reference numeral 16 denotes a fastener that tightens and fixes the second pipe 52 attached to the joint body 14 from the outside. In the following description of the joint 10, the side to which the first pipe 50 is connected is referred to as the front side, and the side to which the second pipe 52 is connected is referred to as the rear side.

[0015] The first pipe 50 may be any pipe having a male thread 51 at its end that can be engaged with the female thread 20 (described later) of the nut 12. Examples include a hard pipe made of metal or resin with the male thread 51 formed at its end, a connecting member such as a nipple, and a piping-shaped connecting portion provided in equipment such as an air conditioner. The second pipe 52 is preferably a relatively flexible pipe such as a hose that can be fitted into the connecting portion 24 (described later) of the fitting body 14. The second pipe 52 may have a single-layer structure made of resin, for example, or a multilayer structure. In the latter case, it may include a metal layer such as aluminum. The fluid flowing through the first pipe 50 and the second pipe 52 is not particularly limited and may be, for example, a liquid, a gas, or a gas-liquid mixture.

[0016] 1 and 2, the nut 12 has an abutment portion 18 therein. The nut 12 also has an internal female thread 20 formed in front of the abutment portion 18 and engaging with the external thread 51 of the first pipe 50. The nut 12 is formed so that the internal diameter of the portion rearward of the female thread 20 is smaller than the internal diameter of the portion where the female thread 20 is formed, and the step between the female thread 20 and the portion rearward of the female thread 20 forms the abutment portion 18 that prevents the fitting body 14 from coming off. Although the nut 12 in this embodiment is made of resin, the nut 12 may be a resin molded product obtained by, for example, injection molding, or may be a machined or forged metal product.

[0017] As shown in Figures 1 and 2, the abutment portion 18 has an abutment surface 19 that abuts against a flange portion 22 (described later) of the joint body 14. The abutment surface 19 may be a curved surface, and is preferably composed of a single curved surface. The abutment surface 19 is a concave surface that curves toward the axial center of the nut 12 from the front side to the rear side. Here, "single curved surface" means that the abutment surface 19 is composed of a bend with a single curvature, and that the abutment surface 19 does not have an inflection point. Furthermore, the abutment surface 19 forms a series of arcs from the inner surface of the abutment portion 18, through which a connecting portion 24 (described later) of the joint body 14 passes, to the female thread 20.

[0018] As shown in FIGS. 1 and 2 , the joint body 14 is a tubular member having a flow passage 15 therein. The joint body 14 has a flange portion 22 that abuts against the abutment portion 18 of the nut 12, and the abutment between the abutment portion 18 and the flange portion 22 prevents the joint body 14 from slipping off the nut 12. The joint body 14 also has a connecting portion 24 that is formed with a smaller diameter than the flange portion 22. The joint body 14 is assembled to the nut 12 with the flange portion 22 positioned inside the nut 12 and the connecting portion 24 protruding rearward from the rear opening of the nut 12. The joint body 14 is connected to the second pipe 52 by inserting the connecting portion 24 into the second pipe 52. While the joint body 14 in this embodiment is made of resin, the joint body 14 may be a resin-molded product obtained by, for example, injection molding, or may be a metal product obtained by cutting or forging.

[0019] As shown in FIGS. 1 and 2 , the flange portion 22 is provided at the front end of the joint body 14. The flange portion 22 is formed in a circular shape in rear view, protruding outward beyond the connecting portion 24. The flange portion 22 has an abutment surface 23 that abuts against the abutment portion 18. More specifically, the abutment surface 23 of the flange portion 22 abuts against the abutment receiving surface 19 of the abutment portion 18. The abutment surface 23 is a curved surface, and it is preferable that the abutment surface 23 be formed from a single curved surface. The abutment surface 23 is a convex surface that curves toward the axial center of the joint body 14 from the front side to the rear side. The convex abutment surface 23 and the concave abutment receiving surface 19 abut at least partially. Here, the term "single curved surface" refers to the abutment surface 23 being formed from a bend of a single curvature, and the abutment surface 23 not having an inflection point. It is preferable that the abutment surface 23 and the abutment receiving surface 19 have the same or similar curvature. The side surface 22a of the flange portion 22 has a smaller curvature than the abutment receiving surface 19 and extends linearly in the front-to-rear direction, so that a small gap 26 is formed between the abutment receiving surface 19, which is connected to the female thread 20 by a curved surface, and the outer surface of the flange portion 22, which extends linearly in the front-to-rear direction (see the enlarged view in FIG. 1).

[0020] As shown in Figures 1 and 2, the flange portion 22 has a curved surface at a front portion 28 of the flow passage 15. The front portion 28 is a convex surface that curves outward from the joint body 14 as it moves from the rear side to the front side. The front portion 28 is curved so as to be convex on the side opposite the abutment surface 23. The front portion 28 is also composed of a single curved surface. Here, "single curved surface" means that the front portion 28 is composed of a bend with a single curvature, and that the front portion 28 does not have an inflection point.

[0021] As shown in FIGS. 1 to 4 , the connection portion 24 has a plurality of annular protrusions 30 that protrude outward and are spaced apart in the front-to-rear direction. In a cross-sectional view, the annular protrusions 30 have a generally triangular shape with their tips tilted forward. When the second pipe 52 is fitted into the connection portion 24, the annular protrusions 30 abut against the inner surface of the second pipe 52 to function as a barb that prevents the second pipe from coming loose, and also function as a seal that seals the gap between the second pipe 52 and the connection portion 24. Reference numeral 32 denotes an O-ring that is attached to the outer circumferential surface of the connection portion 24 and seals the gap between the second pipe 52 and the connection portion 24. The second pipe 52 fitted into the connection portion 24 is prevented from coming loose by the annular protrusions 30, and the O-ring 32 seals the gap between the connection portion 24 and the second pipe 52.

[0022] As shown in FIG. 5 , the nut 12 is circular in front view. The nut 12 has two or more protrusions 34 spaced apart in the circumferential direction of its circular outer circumferential surface. While the protrusions 34 are preferably spaced apart in the circumferential direction of the nut 12 at regular intervals, they may also be spaced apart at different intervals. In the nut 12 of this embodiment, ten protrusions 34 are spaced apart in the circumferential direction at regular intervals. The protrusions 34 extend linearly from the front to the rear on the outer circumferential surface of the nut 12. The protrusions 34 have a shape that bulges outward in an arc shape in front view without any corners. The height of each protrusion 34 is preferably lower than the tangent line L between the adjacent protrusions 34. Here, "the height of each protrusion 34 is lower than the tangent line L" means that the distance from the base of each protrusion 34 to the top of the protrusion 34 (the height of each protrusion 34) is smaller than the distance from the base of each protrusion 34 to the tangent line L. The point of contact of the tangent line L is the intersection point from the center of the arc of the outer peripheral surface through the center of the outer peripheral surface between adjacent protrusions 34.

[0023] As shown in Fig. 6, the nut 12 of this embodiment can also be used for a joint body 114 having a connecting portion 124 with an outer diameter different from that of the connecting portion 24 shown in Fig. 1. The connecting portion 124 according to another embodiment can connect a pipe with a larger diameter than the second pipe 52 illustrated in Fig. 1. In this way, by simply changing the outer diameter of the connecting portions 24, 124 without changing the shape of the flange portion 22, it is possible to accommodate a second pipe 52 with a different diameter.

[0024] When using the fitting 10, the fitting body 14 is inserted from the front side of the nut 12, and the connection portion 24 of the fitting body 14 is passed through the inside of the abutment portion 18 of the nut 12 and protrudes to the rear side of the nut 12. At this time, the abutment receiving surface 19 of the abutment portion 18 of the nut 12 faces the abutment surface 23 of the flange portion 22 of the fitting body 14, and the abutment between the abutment receiving surface 19 and the abutment surface 23 restricts the fitting body 14 from slipping out rearward from the nut 12. A packing 36 is placed on the front side of the flange portion 22 arranged inside the nut 12, and the male thread 51 of the first pipe 50 is threaded into the female thread 20 from the front side of the nut 12 to connect the nut 12 and the first pipe 50. As a result, the front surface of the flange portion 22 is pressed against the first pipe 50 via the packing 36, and the abutment surface 23 of the flange portion 22 abuts against the abutment receiving surface 19 of the abutment portion 18. In this way, by sandwiching the flange portion 22 between the first pipe 50 and the abutment portion 18, the fitting body 14 is fixed in a state where it is positioned relative to the nut 12. Then, the second pipe 52 is fitted into the connecting portion 24 protruding from the nut 12, and the second pipe 52 is tightened with the fastener 16, thereby connecting the second pipe 52 and the fitting body 14.

[0025] In the joint 10 of this embodiment, the abutment surface 23 that abuts against the abutment portion 18 of the flange portion 22 of the joint body 14 is a curved surface, and therefore, when a force is applied to the joint body 14, the force can be dispersed in multiple directions from the abutment surface 23 (see the arrows in the enlarged view of FIG. 1 ). This reduces the load on the base portion of the joint body 14 where it is assembled to the nut 12, making the joint body 14 less likely to be damaged. Moreover, because the joint body 14 is less likely to be damaged as described above, the joint body 14 can be made of resin, which has lower strength than metal. Furthermore, by forming the abutment surface 23 of the flange portion 22 as a single curved surface, it is possible to prevent force from concentrating on a specific location on the abutment surface 23, and the force applied to the joint body 14 can be dispersed in multiple directions.

[0026] The nut 12 has a curved abutment surface 19 that abuts against the flange portion 22 of the abutment portion 18, so that when force is applied to the abutment portion 18 from the joint body 14, the force can be dispersed in multiple directions from the abutment surface 19. This reduces the load on the base portion of the joint body 14 where the nut 12 is assembled, making the nut 12 and the joint body 14 less likely to break. Moreover, because the nut 12 is less likely to break as described above, the nut 12 can be made of resin, which has lower strength than metal.

[0027] The nut 12 has two or more protrusions 34 spaced apart in the circumferential direction on its circular outer peripheral surface. Because the outer peripheral surface of the nut 12 is circular, when the nut 12 is clamped with a tool such as a wrench, the gripping surface of the tool and the outer peripheral surface of the nut 12 do not come into flat contact, making it less likely to receive force. This makes it less likely for the nut 12 to be damaged when clamped with a tool such as a wrench. Furthermore, the circular outer peripheral surface of the nut 12 allows the axial thickness of the nut 12 to be greater than when the outer peripheral surface is formed by connecting flat surfaces, such as a hexagon. This also makes it less likely for the nut 12 to be damaged when clamped with a tool such as a wrench. Because the nut 12 is less likely to be damaged as described above, the nut 12 can be made of resin, which has lower strength than metal.

[0028] By forming the height of the protrusions 34 to be lower than the tangent line L passing through the center of the outer peripheral surface between the protrusion 34 and another adjacent protrusion 34, when a force of a certain load or more is applied to tighten the nut 12 with a tool such as a wrench, it is possible to reduce the possibility that the tool will slip on the arc-shaped outer peripheral surface of the nut 12 and damage the nut 12. Furthermore, even if an excessive load is applied to the nut 12 by the tool, only the protrusions 34 will be broken, thereby reducing the possibility of serious damage to the nut 12.

[0029] (Example of change) The present invention is not limited to the above-mentioned matters, but may be, for example, as follows: Note that the present invention is not limited to the specific descriptions of the embodiment and the following modified examples.

[0030] (1) In this embodiment, both the nut and the joint body are made of resin, but this is not limiting. The nut may be made of resin while the joint body is made of metal, or the nut may be made of metal while the joint body is made of resin. It is preferable that the nut and / or the joint body are made of resin. (2) Both the nut and the joint body may be made of metal. [Explanation of symbols]

[0031] 10 joint, 12 nut, 14 joint body, 18 abutment portion, 19 abutment receiving surface, 22 flange portion, 23 contact surface, 34 protrusion

Claims

1. a nut having an abutment portion therein; a joint body having a flange portion that abuts against the abutment portion and that is prevented from coming off the nut by the abutment between the abutment portion and the flange portion, A joint, wherein the abutment surface of the flange portion that abuts against the abutment portion is a curved surface.

2. 2. A joint according to claim 1, wherein the contact surface of the contact portion that contacts the flange portion is a curved surface.

3. 2. A joint according to claim 1, wherein the abutment surface is formed by a single curved surface.

4. 2. A joint according to claim 1, wherein the nut has two or more projections spaced apart in the circumferential direction on a circular outer periphery thereof.

5. 2. The joint according to claim 1, wherein the nut and / or the joint body is made of resin.

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