JP2009257446A - Joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure which is reduced in previous caulking work to piping pipes as much as possible. <P>SOLUTION: The connecting pipes 12a, 12b are inserted into both sides of a joint body 10 which is arranged in the center, respectively, and tip end faces of the pipes are made to abut on vertical wall faces of both sides of a diameter-reduced step formed at the internal periphery of the center of the joint body. Ring-shaped retaining members 14a, 14b are arranged at external peripheries of the pipes in advance. O-rings 16a, 16b for sealing are arranged at and fixed to the grooves formed at the diameter-enlarged internal peripheral face of the joint body. The end of the joint body is press-crushed toward the external peripheral faces of the pipes so as to surround outside circumferences of the retaining members in order to retain the pipes. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a structure of a pipe joint provided for a relatively low pressure fluid pipe, typically a tap water pipe.

  As a method of joining pipe materials such as metal pipes and pipe joints, a male thread is cut at the end of one pipe to be joined, and this is screwed into the end of the opposite pipe with the female thread cut. Although the method is normal, a sufficient thickness is required to perform threading, which increases the weight and the relative rotation between both pipes, which complicates the joining operation. was there. Furthermore, the pipe connected by such a conventional joining method is half the strength of the connection part compared to other parts, and is not satisfactory in terms of pressure resistance, air tightness, earthquake resistance, etc. due to insufficient screwing. There is.

By solving such problems, it is possible to make two pipes to be firmly joined without giving relative rotation to both pipes, and the cost required for joining is low and not a skilled worker. For the purpose of joining pipe materials that can be easily and reliably piped,
“The end of one of the tubes to be joined is processed with a diameter-expanding jig, and the receiving portion extends over a predetermined length, the tapered receiving portion gradually expands toward the tube end, and the cylindrical portion. And an inwardly bent end part in which the pipe end is bent inward by 90 ° or more, and the end part of the opposite pipe member is inserted into the inside with an elastic gasket ring interposed therebetween. A split tool having an inner surface with a taper forming portion that is substantially perpendicular to the section is disposed opposite to the outer peripheral surface of both pipes, and these split tools are brought close to each other along the pipe axis. The elastic gasket ring is compressed and adhered to the surface, and the inwardly bent end is bent inwardly by 90 ° or more, and is kept in the pipe material while keeping the gentle concave part toward the inside. "Technology has been developed. (Patent Document 1)

Furthermore, there is proposed a pipe material joining method having the same configuration as that of Patent Document 1 in which two C-shaped rings are combined in addition to a gasket ring. That is,
“An end portion of a pipe member to be joined is formed with a tapered portion that gradually increases in diameter toward the end of the tube and a large-diameter portion that remains the largest diameter, and the tapered portion is formed in the receiving portion. Insert the other tube material with a wedge-shaped annular gasket that is in close contact with the inner peripheral surface and a C-shaped ring that is in close contact with the inner surface of the large-diameter portion. A method has been proposed in which a clamping jaw having a tapered inner peripheral surface is pressed in the radial direction to plastically deform the large diameter portion into a tapered shape, and at the same time, the C-shaped ring is bitten into the other pipe. (Patent Document 2)

JP 6-41011 JP-A 63-290631

  However, in any of Patent Documents 1 and 2, as shown in FIGS. 1, 2, and 3, each pipe end must be preliminarily expanded in a tapered shape. A gasket and two C-shaped rings must be prepared. In addition, a caulking tool must be prepared at the time of actual pipe connection work, which is troublesome because the caulking work is performed separately. Special attention should be paid to the order and orientation of the parts.

  As a result of intensive research, examination, and trial manufacture in order to solve the problems described above, the inventor of the present application basically uses the end portions of two pipe materials to be joined in the joining methods 1 and 2 of the patent document. We focused on the fact that the overlapping structure complicates the caulking work described above.

  Therefore, the object of the present invention is to make the end portion of two pipes overlap, and almost no prior processing is required for the piping pipe, and the caulking work is as small and simple as possible. And it is to provide a joint structure that can be simplified.

In order to achieve the above object, the joint structure according to the present invention comprises:
A pipe for piping provided with a substantially ring-shaped member having a diameter larger than that of the outer peripheral surface and a receiving portion for receiving and fixing one end side including the end surface of the pipe for piping on an outer peripheral surface separated from the end surface by a predetermined distance. Consisting of the joint body,
The joint body receiving portion includes:
A first step portion comprising a first inner peripheral surface and a second inner peripheral surface having a diameter substantially the same as the inner diameter and the outer diameter of the pipe, and a second inner peripheral surface, and a vertical wall formed therebetween;
A third inner peripheral surface formed following the second inner peripheral surface of the first stepped portion and having an inner diameter larger than the second inner peripheral surface and larger than the outer diameter of the ring-shaped member; and the second inner surface A second step portion comprising a side wall between the peripheral surface and the third inner peripheral surface;
A retaining portion formed by caulking the third inner peripheral surface covering the ring-shaped member in a state where the end surface of the pipe is in contact with the vertical wall from the outside toward the outer peripheral surface of the pipe,
It features a joint structure consisting of

In that case, a seal portion may be formed on the second inner peripheral surface by an O-ring provided with an O-ring groove and disposed in the groove.
Further, in that case, an adhesive is applied between the second inner peripheral surface and the pipe outer peripheral surface facing the second inner peripheral surface, thereby attacking to form a seal portion. Is possible.
Further, in this case, the hollow formed by caulking the third inner peripheral surface covering the ring-shaped member with the end surface of the pipe being in contact with the vertical wall from the outside toward the outer peripheral surface of the pipe. The stopper is crimped so that the third inner peripheral surface is a regular polygon, preferably a regular hexagon, and can thereby be configured to perform a detent function with respect to the pipe outer peripheral surface. is there.

The joint structure of the present invention described in claim 1 is:
A pipe for piping provided with a substantially ring-shaped member having a diameter larger than that of the outer peripheral surface and a receiving portion for receiving and fixing one end side including the end surface of the pipe for piping on an outer peripheral surface separated from the end surface by a predetermined distance. A joint body, the joint body receiving portion is
A first step portion comprising a first inner peripheral surface and a second inner peripheral surface having a diameter substantially the same as the inner diameter and the outer diameter of the pipe, and a second inner peripheral surface, and a vertical wall formed therebetween;
A third inner peripheral surface formed following the second inner peripheral surface of the first stepped portion and having an inner diameter larger than the second inner peripheral surface and larger than the outer diameter of the ring-shaped member; and the second inner surface A second step portion comprising a side wall between the peripheral surface and the third inner peripheral surface;
A retaining portion formed by caulking the third inner peripheral surface covering the ring-shaped member in a state where the end surface of the pipe is in contact with the vertical wall from the outer side toward the outer peripheral surface of the pipe, and It features a joint structure consisting of
The joint structure has an extremely small number of parts and also has a retaining part and a seal part as separate parts. After inserting the pipe into the receiving part, the third inner peripheral surface is directed from the outer side toward the outer peripheral surface of the pipe. It is only necessary to caulk, and the connection work can be handled very easily.

According to the joint structure of the present invention described in claim 2, since the second inner peripheral surface has an O-ring groove and a seal portion is formed by an O-ring arranged in the groove, It is possible to configure the seal portion by a simple method.
According to the joint structure of the present invention recited in claim 3, an adhesive is provided between the second inner peripheral surface and the pipe outer peripheral surface facing the second inner peripheral surface. As a result, the seal portion is formed, so it is different from the seal portion by the O-ring, and it is not necessary to form a groove or the like on the second inner peripheral surface. Is possible.

  According to the joint structure of the present invention described in claim 4, the third inner peripheral surface that covers the ring-shaped member in a state where the end surface of the pipe is in contact with the vertical wall is arranged on the outer periphery of the pipe from the outer side. The retaining portion formed by crimping toward the surface is crimped so that the third inner circumferential surface is a regular polygon, preferably a regular hexagon, In addition, the tool for caulking into a regular hexagonal shape has a simpler structure than that for caulking the circumference equally.

  FIG. 1 is an axial sectional view of an embodiment of a joint structure according to the present invention. In the figure, metal pipes 12a and 12b for connection are respectively inserted on the left and right sides of the joint body 10 arranged at the center, and the end surfaces of the pipe tips are connected to the joint body 10 respectively. Are in contact with the vertical wall surfaces on both sides of the small-diameter step portion formed in the inner peripheral central portion. Reference numerals 14a and 14b are ring-shaped retaining members provided in advance on the outer periphery of each pipe before inserting the pipe. Reference numerals 16 a and 16 b are O-rings for sealing, and are attached to grooves formed on the inner peripheral surface of the joint body 10.

The ring-shaped retaining members 14a and 14b may be steel C-shaped rings, but it is also possible to use, for example, aluminum wires having a circular cross section that are resistant to corrosion. 14b is attached to the groove part formed in the outer peripheral part previously separated from pipe 12a, 12b end surface by the predetermined distance before pipe insertion. The groove portion may be turned on the outer peripheral portion of the pipe main body, but the pipe itself can be formed by plastic working so as to have a protruding portion having an outer peripheral shape similar to the retaining member 14a.
In order to prevent the pipe from coming off, the end portion of the joint body 10 is crushed toward the outer peripheral surface of the pipe so as to surround the outer periphery of the members 14a and 14b.

In the embodiment shown in FIG. 1, the sealing function part and the retaining function part are separated in the axial direction, and each function is realized separately. Therefore, as a sealing function, it is possible to apply the adhesive immediately before the outer periphery of the pipe and the inner periphery of the joint body, instead of the O-ring method. In particular, an adhesive can be used for a tap water pipe line as long as it can withstand an internal pressure of about 1 MPa even if the water hammer phenomenon is taken into consideration. Recent advances in industrial adhesives are remarkable, not only improving adhesive performance, but also having a certain degree of elasticity even after completion of bonding, in addition to sealing properties, joint body and pipe Since it is possible to give elasticity to the coupling, the joint structure has flexibility even when an unexpected external force acts near the pipe or the joint body.
Also, the use of an adhesive is advantageous because the O-ring and O-ring groove processing in the O-ring system is unnecessary.
In FIG. 1, the pipe insertion portion of the joint body 10 has the same configuration on the left and right, but it is not always necessary to provide the pipe insertion portion on both the left and right sides. Also good.

  FIG. 2 shows the transition of the assembly process of the joint structure according to the present invention, in which (a) shows the joint body and the pipe inserted into the body in an axial section, and (b) shows the joint. An axial sectional view showing a state in which the pipe end face is inserted into and contacted with the vertical wall of the main body, (c) shows the right end portion of the joint body being crimped, and a retaining portion is formed between the joint body and the pipe. (D) is a schematic diagram showing that the outer periphery of the right end portion of the joint body is crimped into a regular hexagonal shape.

  As shown on the left side of FIG. 2 (a), the joint body 10 includes an inner peripheral surface (small inner peripheral surface) having the same inner diameter as the inner diameter of the pipe 12a and an inner periphery having the same inner diameter as the outer diameter of the pipe 12a. A surface (large inner peripheral surface), a vertical wall 10a provided between the small inner peripheral surface and the large inner peripheral surface, an inclined wall 10b following the large inner peripheral surface, and a larger diameter It is comprised from the edge part 10c which has an internal peripheral surface. Before inserting the right pipe 12a, a ring-shaped retaining member 14a is attached to the outer circumferential groove of the pipe 12a, and an O-ring 16a is formed in each of the O-ring grooves formed on the large inner circumferential surface. It is attached.

  The vertical wall 10a, the small-diameter inner peripheral surface and the large-diameter inner peripheral surface constitute a first step portion in the present invention, and the inclined wall 10b following the large-diameter inner peripheral surface and the larger-diameter inner peripheral surface. The inner peripheral surface constitutes the second gap portion in the present invention. And in this invention, the area | region which consists of these 1st and 2nd level | step-difference parts and each inner peripheral surface is defined as the receiving part for receiving and fixing the one end side of a pipe.

  In FIG. 2B, the pipe 12a is inserted into the receiving portion, its end face abuts against the vertical wall 10a, and the ring-shaped retaining member 14a is the left end of the inner peripheral surface of the end portion 10c of the joint body 10. It shows that it has contact | abutted to the part and the inclination wall 10b.

  FIG. 2C shows a state in which the pipe 12a is inserted and held in the joint body 10 and the outer peripheral side of the end portion 10c of the joint body is crimped toward the outer circumference of the pipe 12a. In this caulking operation, it is preferable that the left end portion of the end portion 10c surrounding the outer periphery of the retaining member 14a is removed.

  FIG. 2D is a schematic view of the arrangement relationship between the pipe 12a and the end portion 10c when the caulking work is finished as viewed from the axial direction (right side of FIG. 2C). In this example, the end portion 10c is crimped to a regular hexagonal shape with respect to the outer peripheral surface of the pipe 12a, and the inside of each side abuts on the outer peripheral surface of the pipe. As a result, the pipe 12a has a function of preventing rotation. . Further, for preventing rotation, not only a regular hexagon but also a square or a regular octagon can be used. However, in consideration of the configuration of the caulking tool and ease of use, the regular hexagon is replaced with a regular hexagon. By arranging a pair of opposing molds having three sides so as to be separable from each other, it can be configured very simply.

FIG. 3 shows a state immediately before the pipe 12b on the left side in FIG. In the figure, a ring-shaped retaining member 14b is attached to the pipe 12b at a position separated from the right end by a predetermined distance.
FIG. 4 shows a state where the pipe 12b inserted in FIG. 3 is crimped by crushing the end portion on the left end side of the joint body 10 as shown by an arrow.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these exemplified contents, and those skilled in the art can implement various modifications based on them. is there. For example, the groove for the O-ring 16a can be formed by plastic working of the joint body 10 itself, like the retaining portion 14a described above.

It is sectional drawing of the axial direction of one Example of the joint structure by this invention. The transition of the assembly | attachment process of the joint structure by this invention is shown, (a) shows a joint main body and the pipe inserted in the main body by an axial cross section, (b) is a pipe end surface on the vertical wall of a joint main body. (C) is an axial cross-section showing that the right end of the joint body is crimped and a retaining portion is formed between the joint body and the pipe. FIG. 4D is a schematic diagram showing that the outer periphery of the right end portion of the joint body is crimped into a regular hexagonal shape. FIG. 2 is a perspective view showing a state immediately before a pipe 12b on the left side of FIG. It is a perspective view which shows the state which has crimped by crushing the edge part by the side of a coupling body left end side with respect to the insertion pipe shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Joint main body 10a Vertical wall 10b Inclined wall 10c End part 12a, 12b Pipes 14a, 14b Ring-shaped retaining member 16a, 16b O-ring

Claims (4)

A pipe for piping provided with a substantially ring-shaped member having a diameter larger than that of the outer peripheral surface and a receiving portion for receiving and fixing one end side including the end surface of the pipe for piping on an outer peripheral surface separated from the end surface by a predetermined distance. Consisting of the joint body,
The joint body receiving portion includes:
A first step portion comprising a first inner peripheral surface and a second inner peripheral surface having a diameter substantially the same as the inner diameter and the outer diameter of the pipe, and a second inner peripheral surface, and a vertical wall formed therebetween;
A third inner peripheral surface formed following the second inner peripheral surface of the first stepped portion and having an inner diameter larger than the second inner peripheral surface and larger than the outer diameter of the ring-shaped member; and the second inner surface A second step portion comprising a side wall between the peripheral surface and the third inner peripheral surface;
A retaining portion formed by caulking the third inner peripheral surface covering the ring-shaped member in a state where the end surface of the pipe is in contact with the vertical wall from the outside toward the outer peripheral surface of the pipe,
A joint structure consisting of   2. The joint structure according to claim 1, wherein the second inner peripheral surface includes an O-ring groove and a seal portion is formed by an O-ring arranged in the groove.   2. An adhesive is applied between the second inner peripheral surface and the pipe outer peripheral surface facing the second inner peripheral surface, thereby forming a seal portion. The joint structure described.   The retaining portion formed by caulking the third inner peripheral surface covering the ring-shaped member in a state where the end surface of the pipe is in contact with the vertical wall from the outside toward the outer peripheral surface of the pipe, 4. The device according to claim 1, wherein the third inner peripheral surface is crimped so as to be a regular polygon, preferably a regular hexagon, thereby performing a detent function with respect to the pipe outer peripheral surface. 5. The joint structure described in item 1.