JPH0432274B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a joint pipe that is interposed between two or more pipe bodies and joins them together.

[Prior Art] In recent years, pipe bodies made of stainless steel and the like have been used in order to improve the service life of water supply and drainage pipes used in water facilities such as air conditioning equipment, hot water supply equipment, and other drainage systems in buildings.

However, as is well known, stainless steel is difficult to solder, etc., and there is a problem in that it is not easy to connect the tubes.

Therefore, in order to eliminate this problem,
A tube connection method disclosed in Japanese Patent No. 63-246589 has been developed. The outline will be explained below based on FIGS. 4 and 5.

Two pipe bodies 101, 101 made of stainless steel
The joint pipe 102 is made of a plastically deformable metal such as stainless steel and has an inner diameter that can be fitted onto the end of the pipe body 101, and has a portion that overlaps with the pipe body 101 when inserted through the pipe body 101. Annular extra wall portions 103, 103 are provided protruding from the outer periphery.

When connecting the pipe bodies 101, 101, the pipe body 101 is inserted into the joint pipe 102, and the anchor 104 and the die 105 are respectively engaged with the end of the joint pipe 102 and the excess wall part 103. 4), the gap between the two is forcibly compressed and at the same time the excess thickness 103 is
is pressed toward the center of the tubular body 101, thereby plastically deforming the joint pipe 102 and the tubular body 101 into a constricted shape and integrating them (FIG. 5).

[Problems to be Solved by the Invention] However, although the above-mentioned prior art can sufficiently achieve the intended purpose of the invention, there are still problems to be solved.

In other words, sufficient watertightness cannot be maintained unless the conditions of the joint pipe 102 and the pipe body 101 are super-finished with a mutual surface roughness of around 1μ and that there are no vertical scratches in the axial direction are met. Therefore, this has been a factor in high costs.

[Means for Solving the Problems] Therefore, the present invention provides a joint pipe 2 which attaches the pipe ends of two or more pipe bodies 1 to connect both pipe bodies 1 together.
It is made of a metal that can be plastically deformed and has an inner diameter that can be fitted onto the end of the tube 1, and has an annular ring on the outer periphery of the part that overlaps with the tube 1 when the tube 1 is inserted. The problem is solved by providing a protruding extra-thickness portion 3 and forming an uneven band 5 consisting of a plurality of annular convex portions 6 having a trapezoidal cross section arranged side by side on the inner peripheral surface corresponding to the extra-thickness portion 3. It is ivy.

[Function] In the process of compressing the excess wall portion 3 to constrict the joint pipe 2 and the pipe body 1, stress concentrates on the convex portion 6 of the uneven band 5 formed corresponding to the excess wall portion 3, and the convex portion 3 is compressed. The portion 6 is strongly pressed against the circumferential surface of the tubular body 1 and is crushed, or the tip of the convex portion 6 bites into the circumferential surface of the tubular body 1, whereby the two are tightly joined.

[Example] An example of the present invention will be described below with reference to the drawings.

A joint pipe 2 that connects the two pipe bodies 1 and 1 made of stainless steel has an inner diameter that can be fitted onto the end of the pipe body 1 and is made of a plastically deformable metal such as stainless steel. Annular extra-thickness parts 3, 3 are provided protruding from the outer periphery of the portion that overlaps with the tube body 1 when inserted. The extra wall portion 3 has a taper that becomes larger in diameter toward the end of the joint tube 2, and an annular protrusion 4 is provided on the inner circumferential surface of the central portion of the joint tube 2.

Further, an uneven band 5 is formed on the inner circumferential surface of the joint pipe 2 corresponding to the extra wall portion 3 . The uneven band 5 is the third
As shown in the enlarged view, a plurality of annular protrusions 6 each having a trapezoidal cross section are arranged in parallel.

When connecting the tubular bodies 1, 1, the tubular body 1 is inserted through the joint pipe 2 to a position where it abuts the annular protrusion 4. Next, the anchor 7 and the die 8 are respectively engaged with the end of the joint pipe 2 and the excess wall portion 3 (Fig. 1),
The anchor 7 is fixed, and the die 8 is forcibly moved toward the anchor 7 by a driving means (not shown) such as a hydraulic cylinder, and the distance between the end of the joint pipe 2 and the excess wall portion 3 is forcibly compressed. . At this time, since the inner circumferential surface of the die 8 is formed in a tapered shape that widens from the outer diameter of the joint tube 2 to the outer diameter of the excess wall portion 3,
While engaging with the taper of the extra-thickness portion 3, the extra-thickness portion 3 is pressed toward the center of the tube body 1. Therefore, as the die 8 moves, the pipe body 1 and the joint pipe 2 corresponding to the extra wall portion 3 are plastically deformed in a constricted shape toward the center (FIG. 2).

In the process of compressing the excess wall portion 3 and constricting the joint pipe 2 and the tube body 1, stress is concentrated on the annular convex portion 6 of the uneven band 5 formed in correspondence with the excess wall portion 3.
Since the annular convex portion 6 has a trapezoidal cross section as shown in FIG. 3, it does not buckle even when stress is concentrated in this way, and both edges of its tip end close to the tube body 1.
By biting into the circumferential surface of the tubular body 1, or by having both edges of the tip strongly pressed against the circumferential surface of the tube body 1 and crushed, the two are tightly joined.

[Effects of the Invention] As explained above, according to the joint pipe of the present invention, pipe bodies made of stainless steel or the like can be easily connected.
In addition, since the joint between the joint pipe 2 and the pipe body 1 can be tightly joined by the uneven band 5 consisting of the annular convex portion 6 having a trapezoidal cross section, there is no need to super finish the surfaces of the joint pipe 2 and the pipe body 1. It becomes unaffected by some vertical scratches, resulting in a significant cost reduction.

[Brief explanation of drawings]

The drawings relate to one embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the state before connection, FIG. 2 is a cross-sectional view showing the operation, and FIG. 4 is a sectional view showing the prior art;
The figure is a sectional view showing the effect of FIG. 4. 1, 1...Pipe body, 2...Joint pipe, 3...Excess wall part, 5...
uneven band, 6... annular convex portion;

Claims (1)

[Claims] 1. A joint pipe that connects the ends of two or more pipe bodies to each other, which is a metal that has an inner diameter that can be fitted onto the ends of the pipe bodies and is plastically deformable. A ring-shaped excess portion is provided on the outer periphery of the portion that overlaps with the tube body when the tube body is inserted, and a plurality of annular convex portions with a trapezoidal cross section are provided on the inner peripheral surface corresponding to the excess thickness portion. A joint pipe for connecting a pipe body, characterized in that a concavo-convex band is formed by arranging the concave-convex bands side by side.