JPS5993299A - Bored plastic pipe and punch for forming bore hole - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to plastic tubes, and more particularly to plastic tubes having a plurality of elongated design having short edges rounded in and around the wall and long side edges between the edges. 1,778,094, and more particularly a cutting edge for forming a hole in the clasp of a plastic pipe, as disclosed in West German Patent No. 1,778,094. Regarding the shoulder punch knife.

Plastic pipes, especially corrugated pipes with a large number of small holes in the wall, are currently used for drainage.

Such corrugated tubes are preferably used for this purpose since they have a high elasticity in the longitudinal direction and a considerable resistance to compression in the materials used.

Smooth drainage pipes are also used for certain purposes. However, it has been found that regardless of the structure of the tube, drilling can result in tearing of the tube, and that these tears can even occur from one hole to another.

As a result of various tests, it was found that the occurrence of tearing at the edges of the holes was dependent on the method and the shape and shape of the holes. It is known in this technical field, for example, to form the holes with rotating claw-shaped knives, but because these knives are sharp, tearing easily occurs at the ends of the elongated holes, and If a beveled knife is used, the size of the passage through the hole is reduced. Even when rectangular holes are formed with special punches and take advantage of uniform passage, tearing occurs at the corners of the holes. However, tests have shown that tearing still occurs between the long, white portions of the holes that join the rounded portions.

One object of the present invention is to provide a perforated plastic pipe, and more particularly a drain pipe, which does not suffer from permanent tearing at the edges of the perforations.

For this purpose, in the above-mentioned excitable plastic tube, the long side edge of the hole is continuously curved, and the lateral dimension of the hole extending perpendicular to the longitudinal direction of the hole is rounded. The lateral dimension of the hole further away from the edge is smaller near the short, rounded edge.

A feature of this structure is that the continuous form of the radius of curvature prevents tearing along the edges of the hole. This has also been proven by testing.

It should be noted that it is already known per se to use diamond-shaped holes whose sharp corners are chamfered, ie rounded. However, even with these holes, tearing occurs at the corners of the diamond-shaped portion where the straight portions of the flanks join. Therefore, in such a hole, the long 111] green is not formed in a continuous curve.

In one embodiment of the invention, the plastic tube is structured in such a way that the elongately designed holes are oblong and preferably oval.

To form these holes, a punch is used, more particularly a punch knife with a cutting tip for forming holes in the wall of the plastic tube. This punch has a large length-to-width ratio in its working cross section, with the rounded portion of the punch extending in the width direction between its side flanks. According to the invention, this punch has side flanks such that a tangent line running from one rounded section to the other always intersects the associated side flank at a point in the cross section. The cross section is curved +i4 in the longitudinal direction. Therefore, in the case of a punch, the radius of curvature is similarly continuous so that t'! It has been done. The punch according to the invention also has a description line extending from the cross section to the cutting edge of the chip on a curved side flank.
is shorter in the vicinity of one rounded part than a similar drawn line further away from the associated rounded part.

The holes in the wall of the drain tube are preferably not precisely formed radially, but are formed substantially in the direction "6" on both sides of the tube, so that they can be very legally formed on the outside and inside of the hole. It is preferable to slope inward so that care can be taken.Although it is not difficult to form holes in the radial direction, holes may be made in manufacturing to make the vessel operate more smoothly and to reduce the deformation of the tube. For the following reasons, it is advantageous to form the holes substantially in the tangential direction.Viewed from the outside of the tube, the holes can be regarded as one part with an outer part and one part with an inner part. In Figures 1 to 5, the right side of the illustrated hole is the inner side of the hole, and the left side of the hole is the outer side of the hole.As a result, the tube wall material can also be seen. I can do it.

FIG. 1 shows a hole of elongated design with rounded short edges 1 and 2 for the inner and outer parts of the hole, respectively. A long side edge 6 extends between these rounded edges 1 and 2. Experiments have shown that tearing occurs at the transition between the long straight lateral line 6 and the rounded short edges 1 and 2. This tear is designated by numeral 4.

If the ends of the holes were rounded to a smaller radius as shown in FIG. Tearing occurs at the point where it connects to the rounded portion 2a via the wire 15.

In this regard, an experiment was carried out in which a heavy key was dropped inside the hole of the rounded part 1 and also outside each of the rounded parts 2.2a. If the diagonal line extends from the rounded part 2a to the rounded part 1, as shown by the diagonal flank 5a in FIG. M6, then m between the flank 5a and the rounded part 1 ” Tearing 4 occurs only at the transition portion. In FIG. 4, flank 6b and diagonal flank 5 are shown.
b is used, and flank 6b and flank 5
It was found that no tearing occurred between the two.

Therefore, in view of this experience, the rounded portion 2a is displaced inside the hole, as indicated by the reference numeral 2b in FIG. However, experience has shown that tearing nevertheless occurs at the transition between the diagonal flanks 5b and 5c, as indicated by 4b.

Therefore, plastic pipes in which tearing of the holes does not occur, and more particularly plastic drains with holes in the wall of elongated form, each having a rounded short end edge and a long side edge between them. Various attempts have been made to obtain tubes. According to the invention, this means that the long side edge of the hole is continuous with two
The bending is made possible by making the lateral dimension of the hole perpendicular to the longitudinal direction of the hole smaller than the lateral dimension of the pre-arranged hole in the vicinity of the short rounded edge. In this case, the plastic tube can have an oval hole with a continuous radius of curvature that is elongated. This will be explained with reference to punches for forming these holes as illustrated in FIGS. 6 to 9.

The shape of the hole is shown in FIG.

The 0tlj view of FIG. 6 and the end elevation view of FIG. 7 show a punch, and more particularly, a punch knife for piercing a single tip to form a hole in the wall of a plastic tube. . The effective cross section of this punch has a ratio of large length to 111i, and the rounded section extends in the direction of the width li+1 of the side flanks of the punch. The length and width of the punch are indicated by the numerals and B in FIGS. 6, 7 and 8, respectively.

In the punch according to the present invention, the longitudinal direction of the cross section is;
The side 7 ranks are curved in such a way that a tangent 8 extending from one rounded section 7 to the other rounded section 7 always contacts the associated side flank 6 at a point in the cross section. There is. Therefore, this punch can punch out a hole with a continuous radius of curvature.

As shown in FIG. 6, the curved side 7 sink 6 in the vicinity of the rounded portion 7 from the cross section indicated by line 9
The drawing line 11a extending to the cutting edge 10 is shorter than a similar drawing line 11b further away from the associated rounded part 7. In one embodiment, the cross section of the working portion of the punch is oval-elliptical or approximately oval.

The cutting tip of the punch is drawn in such a way that a tangent indicated by a line 12 extending perpendicularly to the center line 13 contacts said cutting tip of the punch at a predetermined distance from the center line 13.

Therefore, the punch has a knife edge at its tip flank, and the knife cutting edge of each flank has a rounded section 7 on one side and a rounded section 7 on the other side, as is clear from FIG. It extends along a curved line up to the end.

The knife blade of each punch also extends laterally into a circular curve. (FIG. 7) The knife blade 10 is formed in a known manner by a figure-seven groove in the tip, and the resulting cutting edge can be called a "fish snout". This 7-shaped groove extends from one rounded section to the other rounded section, and the base of the V-shaped groove has a straight-on shape as shown by dashed line 14. . The bases of the V-shapes 4 also form an acute angle with respect to a transverse plane, such as the tangential plane 12, which extends perpendicularly to the plane of the centerline of the punch. In actual practice, it was found that no tearing occurred in the holes formed in the pipe wall with this type of punch. FIG. 10 shows the holes formed in the tube wall by this punch.

Therefore, this elongated hole is formed in the rounded part 7 of the punch.
The small, rounded portion 2a on the short side formed by the punch and the long continuous curved flank 15 formed by the punch flank 2 are fixed.

The hole illustrated in FIG. 10 is, for example, a top plan view l of the hole 16a.
(Fig. N11), and since this hole is arranged tangentially, the wall 2'Fl of the rounded part 2a
is visible. Therefore, part of this hole can be considered as the outside. Although the wall portion 2'a of the opposing round portion 2a is not visible in the figure, this portion is considered to be inside.

The small rounded portions 2a, K may result in a bulge on the inside of the tube (as indicated by 17 in FIG. 10), but this will not affect the shape of the hole passage. +t not. The holes according to the invention thus have channels whose shape does not change in the punching direction, which is advantageous for the drainage flow when the pipe is used for drainage.

Since all the holes in the tube wall are arranged tangentially, the holes 16
a and 16b and diametrically opposed holes 16c and 16d are formed simultaneously. The direction of punching these holes is to connect holes 16'a and 16'b to holes 16'C and 16/d that are diametrically opposed to them.
45 in the circumferential direction against the punch to form with
°It is biased. While doing so, the hole 16a,
16b, 16c, i6d are holes 16'a, 16'b
, 16'c, 16'd.

Although it is possible to form these holes in the crests of the corrugations of the corrugated layer, it is preferable to form these holes in the troughs between the corrugations, as can be seen from Figure 12.

In this case holes 1<5a-16d are arranged in one corrugation and holes 16'a-16'd in the next corrugation. It is not absolutely essential that the two sets of holes always be formed diametrically opposite each other. Depending on the inertia of the j-groove path required, fewer holes can be formed along the periphery and some of the troughs between the corrugations can also be omitted.

However, the hole arrangement pattern is as shown in Figure 11 and Nishiki 1.
It is preferable to form as illustrated in FIG.

The aforementioned holes do not necessarily need to be formed by cutting punch tips as shown in FIGS. 6, 8 and 9, but can be formed by piercing punch tips as illustrated in FIGS. 13 and 14. You can also do that. The lateral side of this latter punch (shown in FIGS. 13 and 14) is exactly as shown in FIG. 17. In FIG. 13, the chip flank 6 of the rounded portion 7 on the left end side is much longer than the rounded portion 7 on the right end side of the punch. . This punch therefore has a rounded, complete tip 17. Therefore, the drawing line extending closer to the rounded part 7 from the cross section 9 to the tip of the punch is longer than the drawing line located closer to the center line 1'5 of the punch. These drawn lines are indicated by reference numerals 11a and 11b, respectively, on the left end side of the punch. The issues applicable to the drawn lines 11a and 11b in FIG. 6 also apply to the right end side of this punch.

This type of piercing punch can have a plate structure as illustrated in FIGS. 15 and 16.

In this case, two points 17a and 17b are respectively formed on the cutting tip of the punch. A curved cutting edge 10 is provided along the flank 6 by forming a V-shaped groove 14b at the end of the punch. Points 17δ and 17b which contact the tangential plane 12 extending perpendicularly to the centerline 16 of the punch are arranged at a predetermined distance from the centerline 13. In the case of the punch illustrated in FIGS. 17 and 18, one central piercing point 17c is formed at the position where the center line 13 intersects the tangential plane 12. center line 1
1a and 11b also satisfy the conditions described for FIG.

19 and 20 are variations of the punch of FIGS. 17 and 18. This cutting tip also has curved cutting edges 10, but these curved cutting edges 10 have the shape of a fish snout to form the cutting edge 10 by forming a wat-damiso at point 17d. portion is obtained. However, in all of these variants of punches,
The cross-section of the punch ultimately conforms to the cross-section illustrated in FIG. 7 in order to form the hole illustrated in FIG.

[Brief explanation of the drawing]

Figures 1 to 5 illustrate tear patterns of various known types of holes formed in the walls of plastic tubes; Figure 6 shows a section of the punch of the invention seen from the side of the flank; 7 is an end elevational view of the cutting edge of the punch shown in FIG. 6, FIG. 8 is a side view of the punch shown in FIG. Diagram showing the shape, 1st
0 is a similar view of FIGS. 1 to 5 showing the holes in the plastic tube according to the invention, and FIG. 11 is a similar view of FIGS.
12 is a side view of a portion of a plastic tube formed with holes according to the invention in the form of a corrugated drainage pipe; FIG. Figures 160 to 20 are side views of punches designed to have cutting edges different from those of the punches of Figures 6 and 8. 1.2...Rounded edge, 2a ... formed round (τi (min, 6... long side edge, loa... 71
+j 1 part flank, 4...tear, 5, 5a, 5b
, 5c... flank, L... punch length, B...
・Width of punch, 7... Rounded part, 8...
Tangent line, 9... Cross section, 10... Cutting edge, 11 &, 11
b ・、、Drawing line, 12...Tangential line 42 planes, 16...
・Center line, 15...Frank, 2'a, 2'a・
...Wall part, 16a. 16b, 16C, 16d...hole, 16'a, 1
6'b, 16'c, 16'd - hole, 17...cutting edge. ! Shiko7,'y.

Claims (1)

[Claims] 1) A plastic pipe, in particular a plastic pipe for drainage, having a plurality of punched holes in the wall and distributed around the wall, the holes being rounded. The long side edge of the punched hole is continuously curved and perpendicular to the longitudinal direction of the punched hole. characterized in that the lateral dimension of the extending punched hole is shorter in the vicinity of the short rounded edge than the lateral dimension of the punched hole further away from said rounded edge. Plastic pipes, especially plastic pipes for drainage. 2) A plastic tube according to claim 1, characterized in that the punched holes designed to be elongated are oval or oval. 3) have a large length-to-width ratio in the working cross-section;
A punch with a cutting tip for forming punched holes in the wall of a plastic tube according to claim 1, having a rounded section extending in the width direction between the side flanks of the punch, in particular punching knives, the side flanks being stacked such that the engagement extending from one rounded portion to the other rounded portion always intersects the associated side flank at a point in the cross-section; A punch, especially a punching knife, characterized in that one side is curved in the longitudinal direction. 4) Curved (111) from the cross section to the cutting edge of the chip
A special feature W characterized in that the drawn line extending on the part flank is shorter in the vicinity of the nli portion formed in a round shape than the related [also] the similar straight drawn line further away from the rounded part. Punch according to claim 3. 5) Near the part where the drawn line extending on the curved side flank from the transverse TfJ1 to the cutting edge of the chip is formed round, the other rounded part A punch according to claim 6, characterized in that the punch is shorter than a similar drawing line near the 6)) curved side flank from the l'jA section to the cutting edge of the chip. Claim 6, characterized in that the upwardly extending drawn line is longer in the vicinity of the rounded part than similar drawn lines further away from the associated rounded part. Punch. 7) The punch according to claim 3, wherein the punch cross section is oval or elliptical.