JPH0415768Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is mainly used to run a tea garden management device that is constructed so that it is installed one by one between the tea ridges in a tea garden and straddles the tea ridges, and is used for plucking tea leaves, pruning and trimming tea plants. Light-weight tubular rails used for various other tea garden management tasks, especially as shown in Figure 8, the upper end of the support pile a driven almost vertically into the ground is connected to the upper end of the support pile a through the joint b. This invention relates to a butt connection structure for tubular rails supported at a constant height.

Conventional technology The outer circumferential surface of a thin-walled steel pipe is coated with a thin, uniform layer of synthetic resin such as polyethylene to reduce the outer diameter to 28 or 38 mm.
Resin-coated metal pipes with anti-rust coating on the inner surface of the steel pipes have excellent weather resistance and corrosion resistance, as well as considerable strength and rigidity, and have been developed for use as lightweight rails. Specifically, attempts have been made to use a structure as illustrated in FIG. 8 as a rail for a tea garden management device.

The unit length of one tubular rail is about 4m to 5m, which are butt-connected to form a long rail.
Support the upper ends of support piles a erected at a pitch of approximately 1 m to 1.5 m via joints b. Furthermore, the rails are laid in such a way that the connecting joint of the rail is located in the center of one of the joints b.

Conventionally, the butt connection structure of the tubular rail 1 has a ninth
This is done as illustrated in the figure. That is, the first
As shown in Figure 0, an inner joint c made of metal and having a cylindrical shape and a split d in the axial direction is used, and the two tubular rails 1, 1 have an inner joint c in the hollow part of the inner joint c about half the length. The tubular rails 1, 1 are inserted into a tight fit state, and the gap (joint) between the abutting end surfaces of the tubular rails 1, 1 is filled with anti-corrosion paint e for rust prevention treatment.

Problems to be solved by this invention Regarding tubular rails installed in tea plantations, etc.
Since rain, dew, chemical solutions, liquid fertilizers, etc. fall on them, the problem of rusting and corrosion is a serious concern.

However, in the case of the conventional tubular rail connection structure,
Although the space between the butt end surfaces of the tubular rails 1 and 1 is filled with anti-rust paint e for anti-corrosion treatment, the tubular rails 1 were originally butt-connected via an inner joint c in a so-called interference fit. However, it is unavoidable that the cut end surface of the tubular rail 1 will be exposed to the atmosphere due to loosening in the pulling direction.

In addition, unavoidable vibrations when the tea plantation management equipment runs over the rails, or shocks caused by people stepping on the rails or colliding with equipment, may affect the filling level of the anti-corrosive paint e. It was also an unavoidable fact that the paint film would be destroyed.

Therefore, even if the outer peripheral surface of the resin-coated metal tube used in the rail is completely rust-proofed by the coating resin, rust and corrosion of the steel tube will occur from the cut end surface exposed to the atmosphere at the connection part. A major problem was that the corrosion progressed rapidly, impairing the useful life of the rail.

In addition, rainwater infiltrates into the tubular rail 1 from locations where the connection has become loose or the filling state of the anti-rust paint e has been destroyed, causing water to accumulate inside the tubular rail 1. There was also the problem that the rust preventive coating on the inner surface of the steel pipe eroded over time, causing rust and corrosion from the inner surface of the steel pipe, resulting in a loss of service life.

Note that such problems are not limited to resin-coated metal pipes, but are common to all metal pipe rails made of rust-prone materials.

Means for Solving the Problems As a means for solving the problems of the above-mentioned prior art, the tubular rail connection structure according to this invention is as follows:
As preferred embodiments are shown in FIGS. 1 to 5 of the drawings, in the tubular rail connection structure in which the tubular rails are butt-connected in an interference fit via an inner joint, a. At the connecting end, a cylindrical cap 2 in the shape of a cylinder with a bottom is fitted into the center of the tubular rail 1 in a substantially tight fit state.

(b) The cylindrical cap 2 has a flange portion 2a having the same outer diameter as the tubular rail 1 on its outer periphery, and is welded to the tubular rail 1 in a watertight manner.

C. The two tubular rails 1, 1 are butt-connected via an inner joint 3 that is fitted in a tight fit inside the bottomed cylindrical cap 2 attached to each connection end. There is.

D. The inner joint 3 has a hollow cylindrical shape, and a tubular rail 1 is provided on the outer periphery of the central portion in the longitudinal direction.
A flange-like or rib-like convex portion 3a within the outer diameter of
It also has a split 3b in the axial direction, and the two tubular rails 1, 1 each have a convex portion 3b.
It has a structure in which it is fitted in such a way that it touches both sides of a.

Function The cut end surface and hollow part of the tubular rail 1 are completely waterproofed by the cylindrical cap 2 with a bottom, which is fitted into the connecting end and welded watertightly, so even if it is not fitted into the inner joint 3, Even if loosening occurs, the cut end surface of the tubular rail 1 will not be exposed to the atmosphere. Further, rainwater, etc. that has entered through the loosened joints only enters the cylindrical cap 2. Therefore, the problem of rusting and corrosion of the tubular rail 1 can never occur.

Further, the inner joint 3 has a convex portion 3a at its center, and the tubular rails 1, 1 each have a convex portion 3a.
Since the butt connection is made with the inner joint 3 in abutting contact with the tubular rail 1, there is no problem such as the inner joint 3 being biased and deeply fitted into either one of the tubular rails 1.

Embodiment Next, an embodiment of the present invention shown in the drawings will be described.

1 and 2 show a tubular rail connection structure according to the present invention. In the figure, 1 is a tubular rail, 2 is a cylindrical cap, and 3 is an inner joint.

As the tubular rail 1, the 32nd resin-coated metal tube mentioned above is used.

The cylindrical cap 2 is an injection molded product of polyethylene and has a cylindrical shape with a bottom. This cylindrical cap 2
has an outer diameter slightly larger than the inner diameter of the tubular rail 1, and is fitted into the hollow portion of the connecting end of the tubular rail 1 in an almost tight fit. The depth of the cylindrical cap 2 is approximately 40 mm, and a flange portion 2 having the same outer diameter as the tubular rail 1 is provided on the outer periphery of the mouth edge.
a is formed to have a thickness of about 2 mm, and the cut end surface of the tubular rail 1 is fitted into the inner surface of the flange portion 2a so that it tightly contacts the inner surface (FIG. 3). In particular, the flange portion 2a of the cylindrical cap 2, the cut end surface of the tubular rail 1, and other portions are welded watertightly by a so-called high-frequency induction heating method as a factory process (FIG. 3).

Therefore, even if this tubular rail 1 is exposed to wind and rain after being shipped from the factory and before being connected at the inner joint 3, there is no risk that the metal tube portion will rust or corrode.

The inner joint 3 is also an injection molded product such as polyethylene. This inner joint 3
The wall thickness is about 3.5mm, and the total length is about 80mm.
Moreover, the outer diameter is slightly larger than the inner diameter of the cylindrical cap 2, and it is formed into a hollow cylindrical shape that can be tightly fitted into the cylindrical cap 2. A flange part 3a having the same outer diameter as the tubular rail 1 and a thickness of about 4 mm is provided as a convex part on the outer periphery of the center part of the inner joint 3. The structure is such that the joint 3 is fitted and connected by equal lengths from both sides of the joint 3 until it comes into contact with the side surface of the flange portion 3a. Also,
The inner joint 3 has a split 3b with a width of about 2.5 mm over the entire length in the axial direction.
The structure is such that the unreasonable force and deformation that occur when the tubular rail 1 is butted and connected in a tight fit state can be avoided by the split 3b.

Therefore, in the case of this connection structure, butt connection and pulling out and disassembly of the tubular rails 1, 1 can be performed relatively easily.

Different Embodiments As the inner joint 3, it is also possible to use a metal one that has been subjected to anti-rust treatment as shown in FIGS. 6 and 7. This inner joint 3 is
First, by drawing a stainless steel plate with a thickness of about 1.5 to 2.0 mm, a rib-shaped protrusion 3a with a width of about 2 mm and a height of about 1 mm is formed.
This steel plate is then rolled into a cylindrical shape, and a split 3b is formed at the seam. Therefore, even if the material is replaced with the synthetic resin material described above, it can be used in exactly the same manner, and the same effects can be expected.

Effects of the present invention As described above in detail together with the embodiments, according to the tubular rail connection structure according to this invention, the cylindrical cap 2 is fitted to the cut end surface and the pipe end opening of the tubular rail 1. Since they are welded in a watertight manner, the cut end surface and the inner surface of the tube are completely rust-proofed against rust and corrosion, making it possible to lay a highly safe track with an excellent service life.

In addition, the tubular rails 1, 1 are fitted to the flange portion 3b of the inner joint 3 for equal lengths, and there is no need to worry too much about rainwater entering through the joints, so the workability of the rail installation work is improved. It is excellent in maintaining the quality of construction.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the tubular rail connection structure according to this invention, and Fig. 2 is a -
3 is a sectional view showing the cylindrical cap installed, FIGS. 4 and 5 are front and right side views of a half section of the inner joint, and FIGS. 6 and 7 are A perspective view and a cross-sectional view of different inner joints, Fig. 8 is a front view of the rail installation state, Fig. 9 is a sectional view showing the connected state of a conventional tubular rail, and Fig. 10 is a diagram of a conventional inner joint. FIG.

Claims (1)

[Scope of Claim for Utility Model Registration] In a connection structure for tubular rails in which the tubular rails are butt-connected in an interference fit via an inner joint, (a) the connecting end of the tubular rail 1 has a bottomed cylindrical shape; The cylindrical cap 2 is fitted into the hollow part of the tubular rail 1 in a substantially tight-fitting state;
(c) The two tubular rails 1, 1 have a flange portion 2a having the same outer diameter as the outer diameter of the tubular rail 1, and are welded to the tubular rail 1 in a watertight manner. The inner joint 3 is butt-connected to the inside of the cylindrical cap 2 in the shape of a bottom tube through an inner joint 3 that is fitted in a tight fit; Tubular rail 1 on the outer periphery of the section
It has a convex portion 3a having an outer diameter within the outer diameter of A tubular rail connection structure characterized by the following.