JPH0622887B2 - Corrugated pipe manufacturing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a corrugated pipe manufacturing apparatus, and more specifically, since it has a large pressure resistance, it is often used as a drain pipe by being buried in soil. The present invention relates to an apparatus for manufacturing a corrugated tube, particularly a corrugated tube having a spiral convex portion on the surface.

(B) Conventional technology In general, corrugated pipes have a tube wall with a concave / convex shape that is axially symmetric or a spiral shape. The concave / convex shape has a spiral shape.
In other words, a corrugated tube having a spiral ridge, for example, spirally winds a strip of molten synthetic resin around the surface of a rotating mandrel, and when the winding is applied, the strip is wound around the strip. The strips to be wound later are supplied so that a part of the strips are overlapped with each other, and a specific cross-sectional shape may be provided along the length direction of the strips between the strips overlapped with the supply of the strips. It is obtained by supplying a flexible core material and forming a spiral ridge on the surface.

The overlapping portions of the strips are pressed and joined by one pressing roller which is provided in parallel with the peripheral surface of the rotating mandrel, and thereby formed into an integral corrugated pipe (see Japanese Patent Laid-Open No. 56-101832). ).

(C) Problems to be Solved by the Invention However, when the overlapping portions of the band-shaped bodies are pressed and joined using the pressing roller as described above, the number of pressing rollers is one, and the pressing is almost point contact. However, if the synthetic resin is hard, the bondability may be lacking, or if the synthetic resin is soft, the cross-sectional shape of the spiral ridge may collapse, resulting in a certain toughness. There was a problem that it was difficult to obtain a corrugated tube.

(D) Means for solving the problem and its action This invention is (i) a synthetic resin extruder for extruding a molten synthetic resin strip, and the same or a synthetic resin extruded from this extruder or another extruder. An extruder for a flexible reinforcing material of different synthetic resin or a reinforcing material for extruding a preliminarily molded flexible reinforcing material, and a belt-shaped body from the synthetic resin extruder is spirally wound and the inside of the belt-shaped body is wound. Alternatively, along the longitudinal direction of the strip on the back surface, a flexible reinforcing material is supplied from an extruder for the reinforcing material to form a ridge portion on the front surface, and the strip portion is wound behind the previously wound strip. A rotating mandrel that forms a corrugated tube having a ridge portion on the surface by superposing a part of the strip-shaped body wound from the ridge, and the ridge portion and the ridge portion while the corrugated tube is held on the mandrel. Concave formed on both sides adjacent to the part An apparatus for manufacturing a corrugated tube, which comprises an endless belt having a concave cross section, which is continuously and simultaneously engaged with the strip portion over at least a half circumference of the corrugated tube, and presses and joins the overlapping portions of the corrugated tube strips. And (ii) a synthetic resin extruder for extruding a molten synthetic resin strip so that its cross section is bent or hollow, and the strip from the synthetic resin extruder is wound into a spiral shape. A ridge portion is formed on the surface by partitioning the reinforcing space along the longitudinal direction of the strip inside or on the back of the body,
A rotating mandrel that forms a corrugated tube having a convex strip portion on the surface by superimposing a part of a band-shaped pair to be wound later on a part of the band that is wound first, and a corrugated tube on this mandrel. While being held, the ridge portion and the ridge portions formed on both sides adjacent to the ridge portion are continuously and simultaneously engaged for at least a half circumference of the corrugated pipe, It is an apparatus for manufacturing a corrugated tube, which comprises an endless belt having a concave cross-section that presses overlapping portions to perform joining and forming.

That is, according to the present invention, a specific endless belt allows linear and continuous simultaneous engagement and pressing of the convex portion and the concave upper portion of the corrugated pipe over a half circumference or more, thereby making it possible to prevent the softness and hardness of the synthetic resin. Moreover, at least the joining property of the corrugated pipe is good, and at the same time, the shaping property is good, and a tough corrugated pipe is obtained.

In the present invention, the endless belt means that the corrugated tube has a convex portion and concave portions formed on both sides of the corrugated tube adjacent to the convex portion, which are continuous over about a half circumference of the corrugated tube, that is, a spiral angle of about 180 degrees or more. It is one of the linear pressing members that simultaneously engage and press, and is formed endlessly to facilitate movement control and engagement and pressing to the corrugated tube. The range in which the endless belt engages and presses the convex portion and the concave portion may be all while the corrugated tube is on the mandrel, but one of them (helix angle 360 degrees) to 5 rounds is preferable, and It is preferably a body winding having 2 to 4 turns. Of course, these body windings may be performed not only from the first winding but also after the first two to three turns.

Since the endless belt having the above-described structure is in constant contact with a high temperature synthetic resin in a molten state, it is required to have heat resistance in addition to original toughness and flexibility. Specific examples of the material include a material obtained by properly laminating cloth with rubber, and heat-resistant rubber is particularly used as rubber. Of course, such an endless belt is preferably cooled by cold water, cold air, or the like.

In the present invention, the cylindrical mandrel is spirally wound so as to overlap a part of the synthetic resin strips supplied in a molten state from the extruder, and the corrugated pipe is continuously fed in one direction to form the mandrel. . Therefore, the cylindrical mandrel is, specifically, a large number of rotors are rotatably supported diagonally (with respect to the axial direction) on the body surface of the cylindrical mandrel, or the mandrels are arranged in a cylindrical shape. The thin cylinders are arranged parallel to each other and obliquely (with respect to the virtual cylinder axis of the mandrel).

(E) Examples The present invention will be described in detail based on the reference examples and examples shown in the drawings. The present invention is not limited to this.

[Reference example]

First, referring to FIG. 1, a continuous manufacturing apparatus 1 for corrugated pipes.
Are a synthetic resin extruder 2 that continuously pushes the molten synthetic resin strip A, and a reinforcing material extruder 3 that continuously pushes out a synthetic resin tubular body B as a flexible reinforcing material. A rotating mandrel 4 for continuously forming a spiral tube C by spirally superposing and winding a strip A and a tubular body B supplied from both extruders, and pressing the superposed portion of the obtained spiral tube C. It is mainly composed of an endless belt 5 as a linear pressing member for joining and shaping a spiral ridge D described later.

The rotating mandrel 4 is configured by arranging a plurality of hollow shafts 6, 7 ... In parallel along a peripheral surface of one virtual cylinder at a predetermined interval, and each hollow shaft has a shaft end (not shown). A sprocket provided on the left side in FIG. 1 is hooked with a chain so as to rotate at a constant speed in the same direction, whereby the rotating mandrel 4 is substantially rotated.

The endless belt 5 has a cross section corresponding to a cross sectional shape of a spiral groove E to be described later of the obtained spiral tube C,
It is movably supported by 9 and 10.

Next, a continuous corrugated pipe manufacturing apparatus 1 having the above-described configuration
The operation will be described with reference to FIGS. 1 to 3, and thereby the continuous manufacturing method of the corrugated pipe will be described.

When the rotating mandrel 4 is rotated (substantially) and the molten polyethylene resin strip A is supplied from the synthetic resin extruder 2 around the rotating mandrel 4, the strip is spirally wound and spirally wound. Form tube C. Further, when the strip A is wound, the polyethylene resin tubular body B is supplied from the reinforcing material extruder 3 to the back of the strip A along the longitudinal direction of the strip A. Thus, the spiral ridge D as a convex portion is formed on the surface of the spiral tube C, and the appearance of the corrugated tube F is substantially adjusted.

Further, the formation of the above-mentioned spiral tube C is performed by overlapping a part of the band A that is wound first with a part of the part of the band A that is wound later, and this overlapping part is the endless belt 5. It is pressed in the form of a body by means of the body and is thereby joined. Usually, the speed of pulling the strip A and the tubular body B by the rotation of the rotating mandrel 4 is faster than the speed at which the respective bodies are extruded, and both bodies are also in a soft state. Therefore, the joining of the overlapping portions of the above strips is performed. Is done for the time being, but is often inadequate. On the other hand, conventionally, the overlapping portion is pressed by using the pressing roller, but since the pressing time (or the distance) is instantaneous, the effect cannot be said to be sufficient depending on the state of the synthetic resin. However, according to the above-mentioned endless belt 5's body-shaped pressing, that is, continuous pressing during a spiral rotation of about 3.5 laps (about 360 × 0.5 degrees),
Ten parts are guaranteed because the overlapping parts are joined continuously for a long time. Further, the cross section of the endless belt 5 corresponds to that of the spiral groove (concave groove) as the concave portion formed between the spiral convex stripes, and the endless belt 5 is continuously engaged for a long time in the same manner. A corrugated tube F having a desired pressure resistance can be obtained. In particular, since the rotating mandrel 4 is rotated, the band-shaped body A and the tubular body B in the molten state are in a tensioned state, so that, for example, the tubular body B is likely to be flat in the parallel direction when the rotating mandrel 4 is rotated, and therefore the normal compressive strength is obtained. However, due to the shaping effect of the endless belt 5 described above, the cross section of the tubular body B is maintained in a predetermined perfect circular shape, and a desired compressive strength is obtained.

Unlike the above example, it is also possible to change the manner in which the strips are superposed and the tubular body is interposed between these strips as shown in FIG. That is, the band-shaped body A covers the two-turn tubular bodies Ba, Ba from the outside with one lateral width.

Next, the continuous corrugated pipe manufacturing apparatus 1b shown in FIG.
Two synthetic resin extruders 2b and 2'b are provided, and two endless belts 5b and 5'b are further provided. That is,
First, a molten polyethylene resin strip A'b is supplied from the extruder 2'b around the rotating mandrel 4b, and the strip is spirally wound to form a spiral tube C'b. The spiral tube C'b is a tube having no spiral concave and convex stripes, and the spiral overlapping portion is pressed by the endless belt 5'b to ensure the joining.
Then, the strip-shaped body Ab and the tubular body Bb are superposed on the obtained spiral tube C′b, as in FIG. Although not described, the obtained corrugated pipe Fb has a double pipe structure as shown in FIG. Note that Gb and Gb are overlapping portions of the strip A′b.

Unlike each of the above examples, the synthetic resin tubular body may be inserted inside the band-shaped body and spirally wound. That is, in FIG. 6, the synthetic resin tubular body Bc is inserted inside the synthetic resin strip Ac in the molten state and spirally wound around a rotating mandrel (not shown) to form a spiral tube.
Then, the overlapping portion Gc of the strip Ac is pressed and joined by the endless belt 5c shown by the one-dot chain line, and the spiral ridge Dc of the strip Ac is shaped. In addition, the strip Ac
Is obtained by feeding the previously molded tubular body Bc into a synthetic resin extruder and extruding it together with the molten synthetic resin while maintaining the tubular body Bc at the center through an extrusion nozzle. As a matter of course, the extrusion nozzle has an opening cross-sectional shape formed in a substantially inverted T-shape corresponding to the cross section of the band-shaped body Ac.

Further, the spiral tube as described above may be covered (on the outside) on the inner spiral tube as shown in FIGS. 4 to 5 to form a double structure as shown in FIG.

Other examples of the sectional structure of the corrugated pipe will be given below.

8 to 10 FIG. 8 shows an example in which a flexible reinforcing material Be such as a hard vinyl chloride resin is inserted on the back surface of the strip Ae along the longitudinal direction of the strip Ae. The example in FIG. 9 shows the strip Af.
10 is characterized in that the overlapping portion Gf is formed with a step, and the flexible reinforcing material Bg is formed in a square section in FIG.

11 to 13 and 14 to 16 The cross-sectional structure of the strip is composed of an inverted U-shaped piece Hh and large and small horizontal pieces Ih and Jh extending horizontally outward from both ends of the piece, and a spiral concave bottom portion of both pieces. The joining portion, the small horizontal piece Jh, and the tip portion of the large horizontal piece Ih are superposed on each other, and appropriately joined by an endless belt (not shown). 14 to 16 show three examples in which the sectional structure of the strip is different from the above.

17 to 19 and 20 to 26. The cross-sectional structure of the band-shaped body has an inverted U-shaped piece Hl, a horizontal piece Jl extending horizontally outward from one end (right end) of this piece, and an inclined piece extending slightly downward from the other end. And a soft piece Kl that closes the downward opening of the hard piece. 20 to 26 show examples in which the cross-sectional structure of the strip is slightly different from the above.

〔Example〕

FIG. 27 The band-shaped body has a hollow portion (Lt) by profile extrusion. Further, the corrugated tube obtained here is such that the convex portion and the concave portion are combined and pressed by the endless belt (5t). Of course, the corrugated pipe manufacturing method and apparatus in this case can be the same as those shown in FIG. 1 except that the cross section of the endless belt is different.

Unlike the above example, two flexible reinforcing materials are simultaneously lined up and inserted inside or on the back surface of one synthetic resin strip and spirally wound, thereby forming a corrugated tube having two spiral ridges. You may. Of course, there are two independent endless belts used in this case.

(F) Effect of the Invention According to the present invention, since the ridge portion and the ridge portion of the corrugated tube are continuously engaged and pressed by the specific endless belt, the pressure joining and the ridge portion of the overlapping portion of the strips are Is sufficiently shaped to obtain a corrugated pipe suitable as a drainage pipe which is particularly required to have toughness.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining a function of a main part showing a reference example for explaining a corrugated pipe manufacturing apparatus according to the present invention, and FIG. 2 is a longitudinal sectional explanatory view for a main part of a corrugated pipe obtained by the device.
FIG. 3 is a view corresponding to FIG. 2 showing another reference example, FIG. 4 is a view corresponding to FIG. 1 showing another reference example, FIG. 5 is a view corresponding to FIG. 2 thereof, and FIGS. No. 2 showing other reference examples
FIG. 11 is a partial side view of a corrugated pipe showing still another reference example, FIG. 12 is a longitudinal sectional view of the corrugated pipe, and FIG. 13 is an enlarged sectional view of a main part of the longitudinal sectional view. , FIGS. 14 to 16 are diagrams corresponding to FIG. 13 showing still another reference example,
FIGS. 17 to 19 are diagrams corresponding to FIGS. 11 to 13 showing still another reference example, and FIGS. 20 to 26 are FIG. 13 showing still another reference example.
FIG. 27 is a diagram corresponding to FIG. 13 showing an embodiment of the corrugated pipe manufacturing apparatus according to the present invention. 1 ... Continuous production apparatus for corrugated pipe, 2 ... Synthetic resin extruder, 3 ... Reinforcing material extruder, 4 ... Rotating mandrel, 5 ... Endless belt, A ... Strip, B ... Flexibility Reinforcement material, C ... spiral tube, D ... spiral convex shape (convex portion), F ... corrugated tube.

Claims (2)

[Claims] 1. A synthetic resin extruder for extruding a molten synthetic resin strip, and a flexible reinforcing material of the same or different synthetic resin as the synthetic resin from this extruder or another extruder, or molded in advance. An extruder for a reinforcing material that extrudes a flexible reinforcing material, and a belt-shaped body from a synthetic resin extruder is wound in a spiral shape, and inside the belt-shaped body or on the back surface thereof along the longitudinal direction of the belt-shaped body. A flexible stiffener is supplied from the extruder to form the ridges on the surface, and the part of the band to be wound later is partially overlapped with the part of the band to be wound first. A rotating mandrel that forms a corrugated tube having a ridged portion on the ridge, and a ridged portion formed on both sides adjacent to the ridged portion while the corrugated tube is held on this mandrel. , At least half the circumference of the corrugated pipe Standing continuously engaged simultaneously, corrugated pipe manufacturing apparatus comprising a strip overlapping portions pressed endless belt concave cross section for performing shaping and joining of the corrugated tube. 2. A synthetic resin extruder for extruding a molten synthetic resin strip so that its cross section is bent or hollow, and a strip from this synthetic resin extruder is wound in a spiral shape, The reinforcing space is defined inside or on the back surface of the strip along the longitudinal direction of the strip to form a ridge on the front surface, and the portion of the strip wound earlier is wound later. A rotating mandrel that forms a corrugated tube having a ridge portion on the surface by overlapping a part of the strip-shaped pair, and a ridge portion and a portion adjacent to the ridge portion while the corrugated tube is held on the mandrel. An endless belt with a concave cross section that engages the recessed portions formed on both sides continuously and simultaneously for at least half the circumference of the corrugated pipe and presses the overlapping portion of the strips of the corrugated pipe for joining and shaping. From Manufacturing equipment of that corrugated tube.