JP3401569B2 - Pipe connection method and pipe joint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a pipe connecting method and an inner pipe joint used in the method, and more specifically, to a pipe connecting method used as a rail and an inner type pipe joint. Regarding pipe fittings.

[0002]

2. Description of the Related Art Agricultural facilities Gardening equipment, which cultivates horticulture, vegetables, flowers, and hydroponics in an integrated manner, mainly uses multiple rows of rails with pipes connected to the site and moves on the rails. It consists of multiple circle benches. When the circle bench is moved by carrying the agricultural facility gardening or the like, the weight of each circle bench is often as large as several hundred kg. For this reason, it is desired that the butt joint between pipes forming the rail has a sufficient level of strength without causing a step so that the circle bench can move smoothly.

Conventionally, in consideration of the above needs, the following pipe connecting method and pipe joint have been disclosed and implemented.

FIG. 10 shows a method of butt-connecting the pipes 15 and 16 in series by way of an inner type pipe joint 14 inserted into the inner diameter surfaces of the pipes 15 and 16.

FIGS. 11A and 11B show a method of butt-connecting pipes 15 and 16 in series through an inner pipe joint 17 in which an annular convex portion is formed as a stopper at the center in the longitudinal direction.

12A and 12B, the pipes 15 and 16 are connected in series by butting through an inner type pipe joint 18 in which two protrusions, which protrude from the inner side to the outer side, are provided at upper and lower portions at a central portion in the longitudinal direction. Shows how.

FIG. 13 shows a member 16a obtained by cutting one end of the pipe 16 into the pipe joint 14 shown in FIG.
Inner type pipe joint 19 formed by welding to approximately the center of
The connection method is shown in which the pipes 15 and 16 are abutted against each other in series via a pipe, and the contact portion with the member 16a is welded.

There is also a method of directly welding the end faces of the pipes and connecting them in series during rail laying work (not shown).

[0009]

The above-mentioned prior arts have the following problems.

1) In the above conventional technique, the pipes 15 and 16 are used.
It can be said that this method is effective as a method in which only one butt-coupling portion is generated and a step is not generated as much as possible. However, when the inner pipe joint 14 is inserted into the one pipe 15 for about half the length and then the other pipe 16 is inserted into the other half, the pipe joint 14 is pushed by the frictional force due to the pushing force of the pipe 16. The phenomenon of further pushing into the hollow portion of the one pipe 15 cannot be forbidden, and it moves to the left side as shown by the chain double-dashed line, and the pipe joint 14 is inserted into both pipes 15 and 16 at substantially equal lengths. That (positioning)
However, there is a problem that it cannot be performed reliably. As a result, the strength of the connecting portion is not constant, and furthermore, a rail having insufficient strength may be laid.

2) In the above-mentioned prior art, although the positioning can be easily performed by the convex portion of the inner type pipe joint 17, the insertion into the pipe is shortened by the length required to form the convex portion, and the strength is lowered. . If the pipe joint 17 is lengthened by the length required for the convex portion, it is possible to provide a connection portion that is stable in terms of strength, but the length increases, so the cost increases. In addition, the root portion of the convex portion of the pipe joint 17 is usually formed in an R shape in order to maintain strength (to prevent stress concentration).
The tips of 5 and 16 cannot come into contact with the convex portion. As a result, a large gap is formed at the two butt joints between the pipes 15 and 16 and the convex portion (FIG. 11B), which defeats the purpose of the joint in which steps are not generated as much as possible.

Further, for example, when 5 m pipes are connected in series and a 100 m rail is laid, the pipe joint 1
In fact, 19 is enough for 7. Therefore, this pipe fitting 1
When 7 is manufactured as a resin molded product or a die cast product, the manufacturing cost of the molding die is high, but the absolute amount used is surprisingly small.

3) In the above-mentioned conventional technique, the root of the convex portion of the inner type pipe joint 18 is formed in an R shape, and similarly to the above-mentioned conventional technique, the tips of the pipes 15 and 16 contact the convex portion. I can't. As a result, a large gap is formed at the two butted joints between the pipes 15 and 16 and the convex portion (FIG. 12B), which defeats the purpose of the joint in which steps are not generated as much as possible.

4) In each of the above-mentioned conventional techniques, a rail having a constant strength can be laid, but the welding work is time-consuming, which is costly and uneconomical. As described above, the pipe connecting methods and the inner type pipe joints of the related arts have advantages and disadvantages, respectively, and are insufficient, and there is room for improvement.

In addition, even though the commercially available pipes have the same standard dimensions, there are many cases in which the actual dimensions, especially the inner diameter, have some dimensional error. Due to such a slight dimensional error, the inner pipe joint may not be able to be inserted into the pipe, or may be in a looser insertion state than the design condition and may not be firmly connected. As a result, there is a risk that a rail having insufficient strength and unevenness may be laid. As described above, the conventional inner type pipe joint and the conventional pipe connecting method using the same have a very important and fundamental problem.

Therefore, an object of the present invention is to use a pipe connecting method and a pipe connecting method capable of realizing a butt connection that does not cause a step as much as possible and maintains a sufficient and constant strength, and is efficient and economical. An object is to provide an inner type pipe joint.

A second object of the present invention is to provide a method of connecting pipes which can flexibly and firmly join together even if the pipe has a slight dimensional error in the inner diameter, and an inner type pipe joint used in the method. It is to be.

[0018]

As a means for solving the above-mentioned problems of the prior art, the pipe connecting method according to the invention described in claim 1 uses an inner type pipe joint inserted into the inner diameter surface of the pipe. In the method of connecting two pipes in series, a notched piece that warps up to an approximately central portion in the longitudinal direction and has an end face as a stopper is formed in an inner pipe joint, and one pipe is the pipe described above. It is characterized in that the notch piece of the joint is inserted from the side facing the end face until it abuts on the same end face, and the other pipe is inserted and connected from the opposite side of the pipe joint until it abuts on the tip of the pipe.

A pipe joint according to a second aspect of the present invention is an inner type pipe joint in which two pipes are connected in series by inserting it into an inner diameter surface of the pipe, and a substantially central portion thereof in a longitudinal direction of the pipe joint. It is characterized in that it is formed by forming a cut-out piece which serves as a stopper against which the tip end of the inserted pipe abuts against the end of the pipe.

A pipe joint according to a third aspect of the invention is characterized in that a slit is formed over the entire length in the longitudinal direction of the pipe joint according to the second aspect or from the edge to the central portion.

According to a fourth aspect of the present invention, there is provided a pipe joint in which a rectangular iron plate having the cutout piece according to the second aspect is formed into a tubular shape having an outer diameter inscribed in an inner diameter surface of the pipe. It is characterized by being formed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of an inner pipe joint according to claim 2. The pipe joint 1 is an inner type pipe joint that is inserted into the inner diameter surface of the pipe to butt and connect two circular pipes in series, and is made of metal or synthetic resin. In this pipe joint 1, a slit 3 is formed over the entire length in the longitudinal direction (claim 3), and a notch 4 which warps in the longitudinal direction is formed in the approximate center of the longitudinal direction adjacent to the slit 3. Has been formed. An end surface 4a of the cutout piece 4 has a pipe 5 into which the pipe joint 1 is inserted.
It is formed as a stopper against which the tip 5a of (FIG. 2) abuts.

The inner type pipe joint 1 of the illustrated example has a cylindrical shape with a wall thickness of about 1.8 mm, and has the slit 3
Has a width of about 2 mm. The cutout piece 4 is formed so that its end surface 4a is warped up so as to come into contact with about 2/3 of the wall thickness of the pipe 5 to be connected. In the case of synthetic resin, it is molded with engineering plastics to have a wall thickness of 3 to 5 mm.
The shape of the inner type pipe joint 1 is not limited to a cylindrical shape, and when connecting a rectangular pipe, it is implemented as a rectangular tube shape.

A method of butt-connecting two pipes in series using the inner type pipe joint 1 is shown in FIG.
As shown in A, first, the right pipe 5 is inserted until its tip 5a comes into contact with the end surface 4a of the cutout piece 4 of the pipe joint 1. Then, the left pipe 6 is inserted into the other half of the pipe joint 1. The pipe 6 advances while pushing the cutout piece 4 inward, and is inserted until its tip 6a abuts on the tip 5a of the pipe 5 (claim 1). In the meantime, the inner pipe joint 1 slides into the hollow portion of the pipe 5 by the abutting effect of the end surface 4a of the cutout piece 4 and the tip 5a of the right pipe 5 regardless of the pushing force of the left pipe 6. Since it does not need to be inserted, it can be inserted into both pipes 5 and 6 in substantially equal lengths as shown in FIG. 2B. Thus, both pipes 5 and 6 can be easily positioned at the substantially central portion of the pipe joint 1.

Next, although the commercially available pipes have the same standard dimensions, there are many cases in which the actual dimensions, especially the inner diameter, have some dimensional errors.
Within the size of the slit 3, the pipe fitting 1
Since it is possible to give a degree of freedom to the outer diameter of the pipe, it is possible to flexibly correspond to the inner diameter of the pipes to be connected, and it is possible to firmly butt and connect the two pipes within the range of design conditions.

Therefore, the pipes 5 and 6 can be firmly butted and connected in series through the inner pipe joint 1. Naturally, it can be said that this is effective as a method in which only one butt-coupling portion is generated and a step is not generated as much as possible. Further, since the pipe joint 1 can be inserted and connected to both pipes 5 and 6 with substantially equal lengths, it is possible to realize a butt connection that maintains sufficient strength. As a result, it is possible to lay a rail that has sufficient strength and is uniform. Further, connect the pipe 5 to the cutout piece 4
Since the pipe can be easily positioned by only bringing it into contact with the end face 4a, it is efficient and economical.

FIG. 3 shows a second embodiment of the inner type pipe joint. This pipe joint 11 is further provided with the cutout piece 4 of the pipe joint 1 shown in FIG. 1 in an arrangement in which the center of the slit 3 is point-symmetrical, so that two cutout pieces facing each other with the slit 3 interposed therebetween are provided. 4 and 4 are formed. The cutout pieces 4 and 4 have respective end faces 4
Since a and 4a also face each other, they can be connected in series by inserting two pipes to be connected from any direction. Therefore, not only the effects and advantages expected in the first embodiment but also more efficient connection work can be performed. Further, the elastic force of the notch pieces 4 and 4 pushed into the tip portions of the two connected pipes makes it possible to expect a stronger connection.

FIG. 4 shows a third embodiment of the inner pipe joint. The pipe joint 21 differs from the pipe joint 11 shown in FIG. 3 only in that the cutout pieces 4 and 4 and the slit 3 are formed separately. Therefore, the same effect as that of the second embodiment can be expected. Of course, when the cutout piece 4 of the pipe joint 21 is implemented by one piece, the same effect as that of the first embodiment can be expected.

As described above, at least one notch piece 4 is provided, which warps in the substantially central portion of the pipe joint in the longitudinal direction thereof and has the end face 4a as a stopper against which the tip of the inserted pipe abuts. The inner type pipe joint having the slits 3 can be implemented in various variations. For example, in FIG.
As shown in FIG. 3, the tip of the slit 13 formed from one end edge of the pipe joint 31 in the longitudinal direction to the substantially center is U-shaped, and the tip of the slit 13 formed from the other end edge to the substantially center. A pipe joint 31 having symmetrically arranged U-shaped parts and the cutout pieces 4 formed from the U-shaped parts can also be carried out in the same manner as in the third embodiment, and has the same operational effect. Can be expected.

The inner type pipe joints 1,
As shown in FIGS. 6 to 9, reference numerals 11, 21, and 31 are square-shaped iron plates formed by punching up preset cutout pieces 4,
The same operation can be carried out by rounding and molding into a cylindrical shape having an outer diameter inscribed in the inner diameter surfaces of the circular pipes 5 and 6 to be connected. Of course, when the square pipes are butted and connected to each other, the pipes may be formed into a rectangular tube shape.

[0031]

EFFECTS OF THE INVENTION The pipe connecting method and pipe joint according to the present invention have the following effects. (1) Since there is only one butt joint between pipes and pipes, it is effective as a method for minimizing steps. Also, since the pipe can be easily positioned by contacting the end face of the cutout piece of the pipe joint and performing the connecting work,
Efficient and economical. Furthermore, since the pipe joints can be inserted and connected to both pipes with substantially equal lengths, it is possible to realize a butt connection that maintains an even and sufficient strength for both pipes. As a result, rails having sufficient strength and constant strength can be laid.

(2) Since the pipe joint has a degree of freedom in the outer diameter of the pipe joint within the range of the size of the slit, the pipe joint can be flexibly adapted to the inner diameter of the pipes to be connected, and two pipes can be designed. It is possible to make a strong butt connection within a range of conditions.

(3) Therefore, two pipes can be firmly butted and connected in series. As a result, a rail with constant strength can be laid.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a pipe joint according to the present invention.

2A and 2B are cross-sectional views showing a method for connecting pipes according to the present invention.

FIG. 3 is a perspective view showing a second embodiment of the pipe joint according to the present invention.

FIG. 4 is a perspective view showing a third embodiment of the pipe joint according to the present invention.

FIG. 5 is a perspective view showing a fourth embodiment of the pipe joint according to the present invention.

6 is a development view showing an iron plate forming the pipe joint shown in FIG. 1. FIG.

7 is a development view showing an iron plate forming the pipe joint shown in FIG.

8 is a development view showing an iron plate forming the pipe joint shown in FIG.

9 is a development view showing an iron plate forming the pipe joint shown in FIG.

FIG. 10 is a cross-sectional view showing a conventional technique.

11A and 11B are cross-sectional views showing a conventional technique.

12A and 12B are cross-sectional views showing a conventional technique.

FIG. 13 is a front view showing a conventional technique.

[Explanation of symbols]

1, 11, 21, 31 Pipe fittings 3, 13 slits 4 cutout pieces 4a end face 5 and 6 pipes 5a, 6a Tip of pipe

Claims (4)

(57) [Claims] 1. A method for connecting two pipes in series through an inner pipe joint inserted into an inner diameter surface of the pipe, wherein the inner pipe joint is warped to a substantially central portion in a longitudinal direction thereof, and an end face is formed. Forming a cutout piece as a stopper, and inserting one pipe from the side facing the end surface of the cutout piece of the pipe joint until it comes into contact with the same end surface, and the other pipe from the opposite side of the pipe joint to the pipe. A method for connecting pipes, wherein the pipes are connected until they come into contact with the tip of the pipe. 2. An inner type pipe joint for inserting two pipes in series into an inner diameter surface of the pipe, wherein the pipe is warped to a substantially central portion in a longitudinal direction of the pipe joint, and an end surface of the pipe joint is inserted. A pipe joint formed by forming a cutout piece serving as a stopper against which the tip of the pipe abuts. 3. The pipe joint according to claim 2, wherein a slit is formed over the entire length in the longitudinal direction of the pipe joint or from the edge to the central portion. 4. The pipe joint according to claim 2, wherein a rectangular iron plate having a cutout piece formed therein is formed into a tubular shape having an outer diameter inscribed in the inner diameter surface of the pipe.