JPS5833350Y2 - Synthetic resin drain pipe - Google Patents

Description

[Detailed description of the invention] The present invention relates to a synthetic resin drainage pipe, and more specifically, it is capable of maintaining an appropriate water flow condition even when the amount of drainage fluctuates, and is excellent even with a relatively small amount of pipe material. This invention relates to a new synthetic resin drain pipe that exhibits rigidity and is also wear-resistant against foreign substances contained in waste water.

As a synthetic resin drain pipe made of hard vinyl chloride resin or the like, a perfect circular drain pipe 1 as shown in FIG. 1 is most widely used.

However, recently, as shown in Fig. 2, a drainage pipe 1 (so-called perforated pipe) in which a large number of small holes 2 are formed in the pipe wall in a direction parallel to the pipe axis has been proposed, and it is possible to form a large wall thickness using the same amount of material. It is attracting attention for its high rigidity.

That is, by forming a large number of small holes 2 in the pipe wall, the entire pipe wall can be made thicker in proportion to the volume of the small holes 2. (The wall thickness is smaller than that shown in Fig. 2), which increases its rigidity.

However, this type of perforated tube has the disadvantage of poor wear resistance.

That is, the bottom of the drain pipe 1 is easily rubbed when foreign substances 3 such as dirt and garbage contained in the drainage water pass through, and if the small hole 2 is formed in the pipe wall, even a slight friction can cause the small hole 2 to be rubbed. The pipe may open in such a way that the part is worn out, promoting the accumulation of impurities and impairing the flow of water, or the bottom of the pipe may be easily damaged, leading to a water leakage accident. There are still problems in its application.

On the other hand, in the drain pipe 1 as shown in Fig. 1, the depth becomes smaller when the drainage volume decreases, so the radius of curvature R1 of the bottom of the pipe is smaller than the radius of curvature R2 of the right part of the pipe as shown in Fig. 3. A drainage pipe 1 has also been proposed that has an egg-shaped structure and can ensure a considerable depth even when the amount of drainage is reduced.

Therefore, it is conceivable to form a large number of small holes inside the drain pipe 1 having a structure that combines the structures shown in FIGS. 2 and 3, that is, an oval structure.

By doing this, it would be possible to maintain the depth when the displacement is small and increase the rigidity at the same time, but in the case of an egg-shaped structure, the wear on the bottom of the tube is more severe than in the case of a perfectly circular structure as shown in Figure 2. This is so significant that it is difficult to imagine that the above effect can be achieved directly through a mere structural combination.

Based on the above-mentioned knowledge and ideas, the inventors of the present invention have conducted intensive studies with the aim of developing a drainage pipe that can exhibit the effects of (1) and (3) above at once and prevent wear and tear accidents as much as possible. I've made progress.

As a result, I learned that all of the above objectives could be achieved by using a drain pipe with the structure shown below, and I was able to complete the present invention.

In other words, the gist of the synthetic resin drain pipe according to the present invention is that the inner circumferential surface of the pipe body is made of an arcuate surface with a relatively large curvature, which should be on the bottom side during piping, and an arcuate surface with a relatively small curvature, which should be on the top side during piping. In a synthetic resin drain pipe constituted by an arcuate surface, all or part of the pipe wall related to the arcuate surface with a relatively large curvature, excluding the pipe wall portion including the lowermost end on the bottom side. It exists in a place where a large number of small holes are formed extending in the direction of the tube axis.

The configuration and effects of the present invention will be explained below with reference to the drawings, which are examples. However, the drawings are only the most representative examples.
It is also possible to change the shape as appropriate for the purpose described later, and all of these are included in the technical scope of the present invention.

FIG. 4 is a cross-sectional view illustrating the synthetic resin drain pipe 1 of the present invention, in which the bottom side has a circular arc surface 4 with a relatively small radius of curvature R1 (that is, the radius of curvature is large), and the top side has a relatively large radius of curvature. Each of them is made up of circular arc surfaces 5 of R2 (that is, small curvature), and the whole is formed into a downward concave shape.

Therefore, even when the amount of water discharged is reduced, the water flows smoothly while maintaining a considerable depth, and the foreign matter 3 is smoothly washed away by this water flow.

Therefore, a situation in which the contaminants 3 settle and accumulate at the bottom of the tube is prevented as much as possible.

Further, in the drain pipe 1, a large number of small holes 2 are formed in the pipe wall portion having a large radius of curvature R2 located above in the pipe state in a direction parallel to the pipe axis.

Therefore, under the conditions of the same amount of resin material and the same diameter, the entire inside of the pipe can be made approximately 20 to 30% thicker than the previous wall thickness, thereby significantly improving the bending strength and bending rigidity of the drain pipe 1. can do.

As is clear from the example in the figure, the small hole 2 was not formed inside the tube at the bottom of the tube (i.e., the arc range of the central angle θ of the large curvature section), but this was done to prevent wear caused by the fluid inside the tube and foreign matter 3. This is to ensure sufficient wall thickness.

In other words, when the amount of fluid in the pipe increases, the local load applied to the bottom of the pipe increases as its weight and flow rate increase.
In order to ensure the local load rigidity of the tube bottom, it is not preferable to form the small hole 2 in the tube bottom.

Further, as the flow rate increases, the contaminants 3 flow faster and are swept away while strongly rubbing against the bottom of the tube, making this part more likely to wear out. Therefore, small holes should not be formed in the bottom of the tube from the standpoint of preventing wear.

However, since the upper part of the drain pipe 1 is not directly subjected to the gravitational action of the fluid in the pipe, and there is little friction due to foreign matter 3, even if the small holes 2 are provided in this part/band, no actual damage related to wear will occur.

Improved In dealing with friction between fluid in piping and foreign matter 3,
The preferred region of the bottom of the tube in which the small hole 2 should not be formed is an arc range of 90 to 180 degrees with the central angle θ at the center point of the radius of curvature R1. This is not preferred because the aforementioned effects are significantly diluted.

By the way, the shape, size, number, etc. of the small holes 2 formed in the pipe wall portion are not particularly limited, and may vary depending on the wall thickness of the drain pipe body, molding workability, strength required for the drain pipe, etc. It can be changed as appropriate.

In this case, the larger and larger the number of small holes 2, the relatively thicker the inside of the tube can be, and the rigidity of the tube 1 can be increased accordingly. As the layer becomes thinner and the impact strength decreases,
They should be determined appropriately while taking into account the balance between the two.

Regarding this point, the present inventors have experimentally confirmed that the total cross-sectional area of the small hole 2 is adjusted to be about 30% or less of the internal cross-sectional area of the upper part of the tube, and It has been found that the best results are obtained when the diameter is approximately the same as the wall thickness of the tube.

The means for forming the small hole 2 is also not particularly limited, but the most common method is to use a large number of rods (according to the diameter of the small hole 2 to be formed) extending from the spider part of the extrusion molding device to the mold discharge port. This is a method in which predetermined small holes 2 are formed at the same time as extrusion molding.

FIG. 5 shows another embodiment of the present invention, in which the first inner surface shape is inverted, and the basic effect is the same as the example shown in FIG. 4.

However, in FIG. 5, since the radius of curvature R1 of the arcuate surface 4 at the bottom of the tube can be made smaller, the effect of the present invention is further enhanced.
2, it is also possible to enjoy the advantage that branch pipe connection work above the pipe 1 can be easily performed.

In the example of FIG. 5 as well, the arc range of the tube bottom where the small hole 2 should not be formed is 90 degrees with the central angle θ at the center point of R1.
~180 degree arc range.

FIG. 6 shows still another embodiment of the present invention, in which a horizontal surface 6 is formed on the outer peripheral side of the bottom of the drain pipe 1 to improve the positional stability of the pipe 1 during or after piping construction.

In other words, as explained in Figs. 3, 4 and 5, the pipe shown in the above figure should be constructed with the part that most protrudes from the center of the pipe as the bottom, but the positional stability during piping is poor and it may roll over. I tend to dislike it.

These problems can be easily dealt with by modifying the shape of the excavation groove or laying suitable pillows, but if a parallel section 6 is formed on the bottom surface as shown in Figure 6, the positional stability of the pipe itself can be ensured. This is convenient because it can be done.

In this case, as is clear from Fig. 6, both sides of the tube bottom are considerably thick, so in this example, the arc range in which the small hole 2 should not be formed is approximately 40 to 90 degrees with the center angle θ. It is possible to reduce the

Although the illustrations have been explained using only cross-sectional views, the shape of the pipe in the longitudinal direction can be understood in the same way as well-known synthetic resin pipes. It can be effectively used as a long or short tube.

Since the present invention is constructed as outlined above, it can be formed as thin as possible using the same amount of material and the same diameter, while maintaining the original feature of perforated pipes, which improves the rigidity of the pipe body. , you can enjoy very real benefits as shown below.

■ A circular arc surface with a large curvature is formed at the bottom of the tube to smooth the flow of drainage and foreign matter, so that sedimentation and accumulation of foreign matter can be prevented as much as possible.

■ Many small holes are formed above the bottom of the tube, where the flow resistance is the greatest and the abrasion caused by foreign substances is the most severe, so that the entire tube can be relatively stabilized without causing insufficient strength at the bottom of the tube. It can be made within the thickness range, and the deflection strength and deflection rigidity can be greatly increased.

[Brief explanation of drawings]

1-3 are sectional views showing a known drain pipe, and FIGS. 4-6 are sectional views illustrating a drain pipe according to the present invention. 1...Drain pipe, 2...Small hole, 3...
... Contaminants, 4... Large curvature arc surface, 5...
...Small curvature arc surface, 6...Parallel part.

Claims (1)

[Scope of utility model registration request] Comparison of synthetic resin drainage pipes in which the inner circumferential surface of the pipe body is composed of an arcuate surface with a relatively large curvature, which should be on the bottom side during piping, and an arcuate surface with a relatively small curvature, which should be on the top side during piping. A large number of small holes extending in the axial direction of the tube are formed in all or a part of the inside of the tube related to an arcuate surface with a large curvature, excluding the inside of the tube including the lowest end on the bottom side. A synthetic resin drainage pipe featuring: