JPS59194187A - Specific-length corrugate pipe made of synthetic resin and manufacture thereof - 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 a novel synthetic resin regular length corrugated pipe that can be easily interconnected, and a simple continuous manufacturing method thereof.

Synthetic resin corrugated pipes have been widely used as drainage pipes for civil engineering. Even though the corrugated pipe is relatively thin, the pipe wall has regular irregularities along the axial direction, so it has much higher buckling resistance than general straight synthetic resin pipes, and Since it is a synthetic resin molded body, there is no risk of rust, it is easy to mold, and it is lightweight.
Since it is inexpensive, it is extremely suitable as the above-mentioned civil engineering drainage pipe buried in the soil. Such a corrugated pipe is formed by expanding a thermoplastic synthetic resin tube in a heat-softened state in the centrifugal direction by air pressure injected into the tube, bringing it to the inner wall of a molding frame with unevenness, and molding the molding frame. It is manufactured continuously by forming blocks. This corrugated pipe has a special flexibility when the diameter is small and the pipe wall is thin.
), and can be wrapped compactly at the construction site by simply unwrapping it and burying it in the soil with almost no interconnection work required; however, if the diameter is large (for example, (300 to 500 mg) Since this type of wrapping is not possible, the pipes taken out from the forming machine are cut to a fixed length (for example, 4 m) on the spot, and therefore it is impossible to connect them directly at the construction site. Therefore, it is necessary to prepare a connecting member (for example, straight pipe) separately, connect it sequentially through this connecting member, and bury it.As mentioned above, although it is extremely suitable as a civil engineering drainage pipe, it is There still remained problems such as the economical disadvantage of having to use a connecting member and the complexity of the connecting work. On the other hand, corrugated pipes with spiral irregularities can be connected without a connecting member by turning them around each other at the connection part and screwing the irregular parts together, but it is possible to connect them without using a connecting member. Work involving such turning in the limited space of a pipe is extremely difficult when working with large diameter pipes, and was never welcomed by construction contractors.

The present invention has been made in view of the above, and provides a novel synthetic resin regular length corrugated pipe which is designed to facilitate connection by forming male and female joints at both ends, as well as an effective and simple manufacturing method thereof. The purpose is to provide the following.

Embodiments of the present invention will be described based on the accompanying drawings. FIG. 1 is a partially cutaway front view showing a typical embodiment of a corrugated pipe according to the present invention, FIG. 2 is a partially cutaway front view of the connection part,
FIG. 3 is a longitudinal cross-sectional view of a main part of a molding apparatus employed in the method of the present invention. That is, the first gist of the present invention is that the large diameter portion 11...
This is a synthetic resin standard corrugated pipe 1 in which small diameter portions 12 and 12 are regularly repeated alternately along the axial direction, and one end has a male having the same diameter as the small diameter portions 12. A contact tube 13 is extended, and the other end is connected to the large and small diameter portion 11...
, 12 . . . , the male contact tube 14 is bulged to be externally fitted onto the male contact tube 13 while maintaining the alternating repetition of
On the outer periphery of the male contact tube 13, locking claws 131 are provided which are elastically inserted into recesses 143 formed by the large and small diameter portions 141...142 of the inner wall of the male contact tube 14. The second feature is that the inner circumferential wall has regular large-diameter portions 211 and small-diameter portions 212 alternating along the axial direction. Multiple half-split molded frame blocks 2 with uneven surfaces created by repeating
A tunnel-shaped molding zone 20 is formed by connecting two block assemblies 2, 2, which are endlessly connected to each other, partially facing each other and running under cooperative regulation, and forming a tunnel-shaped molding zone 20. The thermoplastic synthetic resin extrusion nozzle 3 is inserted from the rear end of the molding zone 20 to continuously extrude the thermoplastic synthetic resin pipe P, and the extruded synthetic resin pipe P is placed in the front of the molding zone 20. At the same time as sealing the synthetic resin pipe P, an air supply pipe 4 is installed inside the synthetic resin pipe P from the extrusion nozzle 3 along the axial direction,
Air is forced into the synthetic resin pipe P through the air supply pipe 4 to expand the synthetic resin pipe P in the diametrical direction, and the pipe wall reaches the inner circumferential wall of the molding frame block 21 of the molding zone 20. In a method for manufacturing a synthetic resin corrugated pipe that is continuously molded into a desired shape by tightening, a molding frame block 21 constituting the two block assemblies 2, 2;
. . ., the inner circumferential wall of a portion of which is the small diameter portion 212 .
It is a smooth curved surface with approximately equal diameter, and the curved surface has small concave depressions 221.
An alternating repeating relationship between the molding frame block 22 for the male contact tube formed with the above-mentioned large and small diameter portions 211...212... is maintained, and the inner diameter of the small diameter portion 231... is the same as that of the male contact tube. These irregularly shaped molding blocks 22 and 23 are substituted with the molding frame block 23 for the male joint cylinder whose inner diameter is at most larger than the inner diameter of the molding frame block 22 for use, and are replaced in each of the above-mentioned endless assemblies 2.2. The molding frame blocks 22 and 23 are formed into pairs, respectively, and arranged so that the blocks 21, 22, 23, etc. of the same type of each assembly 2, 2 are opposed to each other in the molding zone 20, The synthetic resin pipe P that has been continuously expanded and molded in the molding zone 20 is cooled and the portions shaped by the irregularly shaped blocks 22 and 23 are cut to form male and female connecting portions 13 and 14 at both ends, respectively. This is a method for manufacturing a fixed length corrugated pipe 1 made of synthetic resin. The corrugated pipe 1 in the figure has large diameter parts 11 and small diameter parts 12 alternately along the axial direction, similar to a normal corrugated pipe except for the male and female connecting parts 13 and 14 at both ends. It is a cylindrical body having a repeated bellows-like uneven tube wall, and the male connecting tube 13 at one end is connected to the small diameter portion 12.
It is a right circular tube with an inner diameter equal to the inner diameter d of..., and a plurality of locking claws 131 are protruded from the outer periphery at intervals in the circumferential direction. On the other hand, the male connecting tube 14 at the other end has the large and small diameter portions 11...1
The corrugated pipe 1 is bulged in the centrifugal direction by the tube wall thickness Δd while maintaining the repeating relationship of 2..., and the tube wall of the male connecting tube 14 also has large and small diameter portions 141...142.
This small diameter portion 142 has an uneven surface consisting of...
As is clear from the above, the inner diameter of is approximately equal to d+2Δd. The corrugated pipe 1 is manufactured by extruding thermoplastic resin such as polyethylene resin, polypropylene resin, or polyvinyl chloride resin into various dimensions (
Continuously molded into different lengths and diameters.

To connect the corrugated pipes 1 with the above configuration to each other,
The male connecting tube 13 and the male connecting tube 14 are butted together, and the male connecting tube 1 is assembled.
3 into the male contact tube 14 with a little force (when inserted, the locking claws 131 of the male contact tube 13 are elastically invaginated into the recesses 143 while slightly expanding the tube wall of the male contact tube 14 ( (See Figure 2).As a result, the male contact tube 14 is externally fitted onto the male contact tube 13, and the locking claws 131 are locked to the side walls of the recesses 143 to prevent them from coming off in the axial direction, resulting in stability. In this way, the connection between pibuts can be made by simple one-touch fitting of each other in the axial direction without using other connecting members and without turning, making it easy to use at civil engineering construction sites. Connection work can be done smoothly even in narrow burial trenches, and a stable connection is maintained, making this type of construction extremely convenient for construction workers. This is extremely significant as it will fully demonstrate the excellent characteristics of corrugated pipes.

The method for manufacturing the corrugated pipe 1 will be described in more detail with reference to FIG. The molding device shown in the figure is basically the same as the so-called mold type molding device that is widely used in the manufacture of this type of corrugated pipe, and the molten thermoplastic synthetic resin R introduced from outside the system is passed through the extrusion nozzle 3. Molding zone 20
By extruding compressed air A, which was also introduced from outside the system, through the air pipe 4 and blowing it out from the small hole 41 bored in the wall of the air pipe 4, the thermally softened state is The tightly plugged synthetic resin pipe P is expanded in the centrifugal direction,
This is applied to each block 2 to which the unevenness of the molding zone 20 is applied.
1..., and is manufactured continuously by running two endless block assemblies 2, 2 under cooperative regulation. In the method of the present invention, the block assembly 2
, 2 are partially replaced with a molding frame block 22 for a male contact part and a molding frame block 23 for a male joint cylinder. 2, the molding frame blocks 22 for the male contact cylinder and the molding frame blocks 23 for the male contact cylinder are formed into pairs, two each, and are arranged in opposing positions, and in the molding zone 20, each assembly 2, 2 is formed.
These pairs of differently formed mold blocks 22 and 23 are arranged so that they are of the same type and are matched with each other, so that two completed corrugated pipes 1, 1 are molded by one cycle of movement of the assemblies 2, 2. There is. That is, the continuously extruded pipe P is cooled and then placed in the differently shaped formwork block 2.
By cutting with the cutter 6 at the center of the position corresponding to 2.23, the male connecting tube 1 is attached to each end as shown in FIG.
A corrugated pipe 1 having a pipe 3 and a male pipe 14 is manufactured. Reference numeral 5 in the plan view indicates a plug that seals the synthetic resin pipe P in a heat-softened state in the front, and the outer diameter of the plug 5 has a certain clearance between it and the molding frame block 21. Needless to say, it is determined to obtain a desired wall thickness, and its axial length is determined so as to straddle the male joint cylinder molding portion of the pair of irregularly shaped formwork blocks 23, 23. In addition, each block 2 in the molding zone 20
1...22...23... run so as to surround the plug 5, so that the boundary 230 between the male joint cylinder molding part and the normal molding part of the irregularly shaped form block 23 is connected to the plug 5. It is desirable to have a tapered surface that reduces in diameter backwards to prevent it from getting caught. Further, in the above, the differently formed formwork blocks 22 and 23 in the assemblies 2 and 2 are arranged in pairs of the same type and in opposing positions, but they are arranged in pairs of different types, and the pairs in the opposing positions are also placed in the same order. Needless to say, it is possible to do so. In addition, although an example was shown in which two pieces of the corrugated pipe 1 are completed in one cycle of the assembly 2.2, one can be completed by appropriately adjusting the number of substitutes and the arrangement position of the differently shaped formwork blocks 22, 23. It is obvious that pipes of various desired lengths can be obtained by changing the number of pipes molded per cycle.

On the other hand, in the above, the corrugated pipe 1 was explained as having a circular tube shape, but in order to maintain the velocity of the fluid inside the pipe and prevent the accumulation of solids, the cross-sectional shape is made into a jaw shape in about 1/2 area. It is also desirable to design the part to be buried with the part facing down, in which case it is molded in the same way as above by shaping the inner wall of one of the molding frame blocks of the assembly 2.2. Male junction tube 14 to increase flow efficiency
It is also possible to line the inner wall except for the inner wall with a thin sheet to substantially reduce the surface roughness coefficient.

As described above, since the corrugated pipe of the present invention has male and female connecting parts that can be joined to each other at both ends, no other connecting member is required for these connections, and therefore, the economic disadvantages of the conventional pipe are eliminated. In addition, the connection work is simplified, and the excellent characteristics of this type of corrugated pipe can be fully demonstrated even in large-capacity civil engineering and drainage construction.Moreover, its production is faster than the conventional manufacturing equipment of this type, as described above. Since it is achieved by introducing means, it is extremely efficient, and when taken together, it can be said that the value of the present invention is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing a typical embodiment of a corrugated pipe according to the present invention, FIG. 2 is a partially cutaway front view of the connection part, and FIG. FIG. (Explanation of symbols) 1... Corrugated pipe, 1]... Large diameter part, 12.
...Small diameter part, 13...Male connecting tube, 131...Latching claw,
14... Male contact tube, 141... Large diameter portion of male contact tube, 14
2... Small diameter part of male connecting tube, 143... Recess, 2...
Block assembly, 21... Molding frame block, 211.
・・Large diameter portion of molding frame block, 212 ・・Small diameter portion of molding frame block, 22 ・・・molding frame block for male contact cylinder, 2
21... Small concave depression, 23... Forming frame block for male connecting cylinder, 231... Small diameter portion of forming frame block for male connecting cylinder, 20
... Molding zone, 3... Extrusion nozzle 4... Air pipe, P... Synthetic resin pipe. -End- Applicant's agent Patent attorney Hidehiko Matsuno Figure 1 Figure 2

Claims (1)

[Claims] 1. A fixed-length corrugated pipe made of synthetic resin in which large-diameter parts and small-diameter parts are regularly repeated alternately along the axial direction, and one end has a fixed-length corrugated pipe with a diameter equal to the small-diameter part. A male contact tube is extended, and the other end is a bulged male contact tube to be fitted onto the male contact tube while maintaining the alternating repetition of the large and small diameter portions, and the outer periphery of the male contact tube is A fixed length corrugated shimib made of synthetic resin, characterized in that a locking pawl is protruded to be elastically indented into a recess formed by a large and small diameter portion of the inner wall of the male connecting cylinder. 2. A two-block assembly consisting of a plurality of halved molded frame blocks connected endlessly, each of which has an uneven inner circumferential wall formed by alternating regular large-diameter portions and small-diameter portions along the axial direction. A tunnel-shaped molding zone is formed by engaging each other in a facing relationship and traveling under cooperative control, and a thermoplastic synthetic resin extrusion nozzle is inserted from the rear end of the molding zone to extrude the thermoplastic resin in a thermosoftened state. The pipe is continuously extruded, the extruded synthetic resin pipe is tightly plugged in the front of the molding zone, and an air supply pipe is installed inside the synthetic resin pipe from the extrusion nozzle along the axial direction. A method of continuously molding into a desired shape by force-feeding air into the synthetic resin pipe to expand the synthetic resin pipe in the diametrical direction and bringing the pipe wall to the inner circumferential wall of the molding frame block in the molding zone. In the method for manufacturing a resin corrugated pipe, a part of the molded frame blocks constituting the two block assemblies is formed into a smooth curved surface with an inner circumferential wall having approximately the same diameter as the small diameter portion, and a small diameter portion is formed on the curved surface. An alternating repeating relationship between the male contact cylinder molding frame block in which the recess is formed and the large and small diameter portions is maintained, and the inner diameter of this small diameter portion is made slightly larger than the inner diameter of the male contact cylinder molding frame block. The molding block for the male joint cylinder is replaced by a differently shaped molding block, and these replaced differently shaped molding blocks are used as a pair in each of the above endless assemblies, and the same type of molding block of each assembly is used in the molding zone. By arranging the plots so that they face each other, and cooling the synthetic resin tube that has been continuously expanded and molded within the molding zone and cutting the portion shaped with the irregularly shaped block, male and female ends are respectively formed. A method for manufacturing a synthetic resin regular length corrugated pipe, characterized in that a joint is formed.