JPS6139192Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a plastic T-shaped pipe of different diameters used as a joint for plastic pipes.

Plastic T-tubes are manufactured by injection molding, and conventionally used plastic T-tubes of the same diameter have the same wall thickness at the main pipe section and at the branch pipe section.

Figure 1A is a cutaway side view of the right half of a conventional plastic T-tube, and Figure 1B is a cutaway side view of the right half of a conventional plastic T-tube.
-b shows an end view, in which the wall thickness of the branch pipe section 1' and the wall thickness of the main pipe section 2' are made equal to each other, and the rear end of the branch pipe section 1' is provided with a stopper (for the stopper of the insertion pipe). A taper step 21' for a stopper is provided over the entire circumference at the point where the taper step 11' intersects the branch pipe section 1' of the main pipe section 2', and these taper steps 11', 21 ' is joined at the corner of the branch pipe part 1' and the main pipe part 2'(a' in FIG. 1A).

By the way, regarding plastic T-tubes,
There are cases where it is required to make the main pipe part and the thick branch pipe part different in wall thickness for reasons such as matching the difference in diameter of the plastic pipes connected to these pipe parts.

The configuration of the T-shaped pipe in this case corresponds to the configuration shown in FIG. 1A, and is as shown in FIG.
Due to the difference in wall thickness between the branch pipe section and the main pipe section, the axial direction (Y axis) of the branch pipe section 1' and the axial direction (X axis) of the main pipe section 2'
from the n-n axis (X axis, Y axis)
45° angle difference).

Since the connection point between the branch pipe part and the main pipe part is a right-angled corner, there is stress concentration, and if the above asymmetry exists in addition to this stress concentration, there will be no mechanical disadvantage. it is obvious.

Therefore, the first structure in which the wall thicknesses of the branch pipe part and the main pipe part are equal and the above-mentioned symmetry is guaranteed at the point where they are joined is obtained.
Compared to the T-tube shown in the figure, the T-tube shown in Fig. 2 loses the above-mentioned symmetry at the connection point due to the difference in wall thickness between the branch pipe section and the main pipe section. This is disadvantageous because the hydraulic pulsation test shows that
The inventor has confirmed this.

In view of the above points, the present invention is designed to maintain the above-mentioned symmetry at the joints even if there is a difference in wall thickness between the main pipe section and the branch pipe section. The purpose of the present invention is to provide a T-shaped tube with different diameters.

In other words, in a T-shaped pipe in which a branch pipe part having a smaller diameter and wall thickness than the main pipe part is integrally formed in the middle of the main pipe part at right angles, the wall thickness of the base of the branch pipe part is equal to that of the main pipe part. The cross-sectional shape of the joining part of the taper step part for the insertion pipe stopper on the inner surface of the root part of the branch pipe and the inner surface of the main pipe part is made to be symmetrical with respect to the center line of the wall thickness of the joined part. This is a configuration characterized by the fact that it is formed.

The present invention will be explained below with reference to the drawings.

Figure 3A shows a plastic T with different diameters according to the present invention.
FIG. 2 is a cutaway side view of the right half of an embodiment of the tube;
FIG. 3B is a bb end view in FIG. 3A.

In Fig. 3A and Fig. 3B, 1 is the wall thickness T.
The main pipe part 2 is a branch pipe part with a wall thickness t thinner than the wall thickness T, and each pipe part has a groove 1 for attaching a rubber ring.
0, 10 and 20 are provided.

Reference numeral 21 denotes the base of the branch pipe section 2, and its wall thickness is made equal to the wall thickness T of the main pipe section 1. A taper step portion 210 for a stopper is provided at the root portion 21 of the branch pipe portion 2, and this taper step portion 210 is connected to the taper step portion 110 for the stopper of the main pipe portion 1 and between the branch pipe portion 2 and the main pipe portion 1. They merge at the corner (a in Figure 3A). The shape of this combined part a is determined by the wall thickness of the root part 21 of the branch pipe part and the main pipe part 1.
Since the wall thicknesses of n-
It is almost symmetrical with respect to the n-line.

In FIG. 3A, reference numeral 22 indicates a stepped portion formed in the branch pipe portion 2 due to the thickening of the root portion 21 of the branch pipe portion 2. As shown in FIG. The stress concentration in the stepped portion 22 due to the change in wall thickness is substantially in the straight pipe portion. However, the stress concentration due to the asymmetry at the connection point a' due to the difference in wall thickness between the branch pipe section 1' and the main pipe section 2' shown in Fig. 2 is at the corner point, and the shape at the corner point is In addition to the large coefficient, the asymmetry has a further disadvantageous effect on stress concentration, so that the stress concentration at the stepped portion 22 in the T-tube of the present invention is mild compared to this stress concentration.

Figure 4 shows a plastic T with different diameters according to the present invention.
Another embodiment of the branch pipe part 2 is shown, and the root part 2 of the branch pipe part 2 is shown.
The stepped portion 22 at the thickened end of No. 1 exists on the inner surface side,
This stepped portion 22 functions as a stopper for the insertion tube. However, at the thickened base 21, as shown in FIG.
Alternatively, similar to the embodiment shown in FIG. 3B, a tapered stepped portion 210 is provided in order to ensure the symmetry at the joint portion of the branch pipe portion 2 and the main pipe portion 1.

The plastic T-shaped pipe of different diameters according to the present invention has the configuration as described above, and although the wall thicknesses of the branch pipe part and the main pipe part are different, the joint part of the branch pipe part with the main pipe part is In addition, since it maintains the same symmetry as those with the same wall thickness, it is possible to provide a plastic T-shaped tube of different diameters with excellent strength by maintaining strength at the joining point.

[Brief explanation of the drawing]

Figure 1A is a cutaway side view of the right half of a conventional plastic T-shaped tube, Figure 1B is a b-b end view of Figure 1A, and Figure 2 is a conventional plastic T-shaped tube with different diameters. FIG. 3A is a cutaway side view of the right half of the tube, FIG. 3A is a cutaway side view of the right half of the plastic T-shaped tube of the present invention, and FIG.
b is an end view, and FIG. 4 is a cutaway side view of the right half showing another embodiment of the present invention. In the figure, 1 is the main pipe part, 2 is the branch pipe part, 21
210 is a tapered stepped portion for an insertion tube stopper, a is a combined portion, and nn is a center line.

Claims (1)

[Scope of utility model registration request] In a T-shaped pipe in which a branch pipe part having a smaller diameter and wall thickness than the main pipe part is integrally molded at right angles in the middle of the main pipe part, the wall thickness of the base of the branch pipe part is equal to the wall thickness of the main pipe part. The cross-sectional shape of the joining joint part of the taper step part for the insertion pipe stopper on the inner surface of the base of the branch pipe and the inner surface of the main pipe part is formed to be symmetrical with respect to the center line of the thickness of the joined part. A plastic T-shaped tube with different diameters.