JPH01264833A - Manufacture of corrugated pipe - Google Patents

Abstract

PURPOSE:To obtain the tough corrugated pipe excellent in connection and formability by a method in which while the projected part and/or the recessed part of every 1/4-1/2 round of a corrugated pipe, is enabled to be intermittently pushed into engagement in order by a plurality of endless belts, said pushing force is enabled to be regulated in each stage of moving the axis of the corrugated pipe. CONSTITUTION:A polyethylene beltlike body A is fed on the periphery of a rotary mandrel 4 from an extruder 2 and is wound spirally thereon, and when a polyethylene tubular body B is fed on said rear surface along the longitudinal direction of the beltlike body A from a reinforcing material-extruder 3, spirally projected ridges D are formed on the surface of a spiral pipe C. In the forming process of the spiral pipe C, a part of the beltlike body A to be secondarily wound is lapped onto the primarily wound beltlike body A, and said lapped parts are pushed and connected every about 1/2 round successively by each belt of the set 5 of endless belts. Since this connection is intermittently carried out by separate endless belts 5x, 5y..., the property of said connection is guaranteed by the sufficient time to be used therefor and the regulation of said pushing force. Since the cross section of the endless belt 5 correspondents to the spirally projected ridge, the corrugated pipe F with desired pressure resistant strength may be obtained.

Description

[Detailed Description of the Invention] (a) Industrial Application Field This invention relates to a corrugated pipe manufacturing device, and more specifically, it has a large pressure resistance and is often buried in the ground and used as a drainage pipe. The present invention relates to a manufacturing apparatus for corrugated pipes, particularly corrugated pipes having a spiral convex portion on the surface.

(0) Conventional technology In general, there are two types of corrugated pipes: those in which the concave and convex shapes of the pipe wall are axially symmetrical and those in which the concave and convex shapes are spiral.
In other words, corrugated pipes with spiral protrusions are produced by, for example, winding a molten band of synthetic resin in a spiral around the circumferential surface of a rotating mandrel. A flexible material having a specific cross-sectional shape along the length direction of the strip is supplied between the overlapping strips as the strips are fed so that some of the parts of the strips are overlapped. It is obtained by supplying a magnetic core material and forming spiral protrusions on the surface.

The overlapping parts of the strips are pressed together by one row of pressing rollers (a plurality of rollers are attached to one roller shaft) which are arranged parallel to the circumferential surface of the rotating mandrel, thereby forming an integral part. Either it is formed into a corrugated pipe (see Japanese Patent Application Laid-open No. 101832/1983), or it is pressed and bonded continuously around 4 to 5 times around the corrugated pipe using two endless belts, thereby forming it into a similar integral corrugated pipe. (Refer to Japanese Unexamined Patent Publication No. 72082/1982).

(C) Problems to be Solved by the Invention However, as described above, when pressing and joining the overlapping parts of the strips using a row of pressing rollers, there is only one row of pressing rollers, and the pressing force of each roller is Since the bonding is done by almost point contact, it is not possible to take a long press bonding time, and if the synthetic resin is hard, bondability may be lacking, while if the synthetic resin is soft, the cross-sectional shape of the spiral protrusions may be distorted. ,
There was a problem in that it was difficult to obtain a corrugated pipe with a certain strength.

On the other hand, when using one endless belt to continuously press and join the overlapping parts of the strips around 4 to 5 circumferences of the corrugated pipe, since there is only one belt, the pressing force against the strips is the entire belt. There is no choice but to be uniform about this. However, the strip changes from a high-temperature molten state to a low-temperature slightly hard state in the direction of axial movement of the corrugated pipe, and if it is pressed uniformly, the pressing force will be too strong in the high-temperature molten state, which is important. There is a problem in that when the spiral protrusions collapse or are slightly hard, the pressing force is too weak and the overlapping portions cannot be sufficiently joined. Furthermore, endless belts are usually made of rubber-based material, and even if the material is heat resistant, it has a problem of lacking durability because it spends a long time in contact with a high-temperature belt.

(d) Means for solving the problem and its operation This invention comprises (1) a synthetic resin extruder that extrudes a synthetic resin strip in a molten state, and a synthetic resin extruder that extrudes a synthetic resin strip in a molten state; A reinforcing material extruder that extrudes flexible reinforcing materials made of different synthetic resins or pre-molded flexible reinforcing materials, and a reinforcing material extruder that extrudes flexible reinforcing materials made of different synthetic resins, and the inside of the strip while winding the strip from the synthetic resin extruder in a spiral shape. Alternatively, a flexible reinforcing material from a reinforcing material extruder is supplied along the longitudinal direction of the strip on the back side to form a convex strip on the front surface, and the strip is placed on the back side of the previously wound strip. A rotating mandrel for forming a corrugated tube having a convex portion on the surface by overlapping a part of the parts of the band-shaped body to be wound, and while the corrugated tube is held on this mandrel, the convex portion and/or its At least 1/1/2 of the corrugated pipe is attached to the concave portion formed between the convex portions.
(ii) a corrugated pipe manufacturing device comprising a plurality of endless belts that sequentially engage intermittently every 4 to 172 rounds and press the overlapping portions of the corrugated pipe strips; and (ii)
A synthetic resin extruder extrudes a molten synthetic resin strip so that its cross section becomes curved or hollow, and the strip from this synthetic resin extruder is spirally wound to extrude the inside or inside of the strip. A reinforcing space is formed on the back side along the longitudinal direction of the strip, and a convex strip is formed on the front surface, so that the portion of the strip to be wound later is separated from the portion of the strip that is wound first. A rotating mandrel that partially overlaps to form a corrugated pipe having a ridged portion on its surface, and a ridged portion formed between the ridged portion and/or the ridged portion while the corrugated tube is held on this mandrel. A corrugated pipe consisting of a plurality of endless belts that sequentially and intermittently engage at least every 1/4 to 1/2 circumference of the corrugated pipe in the concave grooves and press the overlapped part of the corrugated pipe band. This is a manufacturing defect.

In short, this invention enables a plurality of specific endless belts to sequentially and intermittently engage and press the convex and/or concave portions around 1/4 to 1/2 of the circumference of the corrugated pipe, thereby forming a strip. While press-joining the corrugated pipe for sufficient time, it is possible to adjust the pressing force at each stage of the axial movement of the corrugated pipe (lower the pressing force in soft areas, increase the pressing force in hard areas), Regardless of whether it is soft or hard, the corrugated pipe has good jointability, good shaping properties, and strong corrugated pipe. Furthermore, it uses multiple separate endless belts. The influence of heat can be distributed to each belt, thereby extending the life of the endless belt.
The effort required to replace endless belts can be reduced.

In this invention, a plurality of endless belts are used,
The range in which each endless belt engages and presses the convex portion and/or concave portion of the corrugated pipe is 17
4 to 1/2 laps. Then, the engagement and pressing of each endless belt is performed intermittently in sequence. Here, the interval between the engagement and pressing of each endless belt, that is, the period during which the endless belts are not engaged and pressed is preferably 1/6 to 1 round of the corrugated pipe. The endless belt may engage and press as much as possible while the corrugated pipe is on the mandrel as a whole, but the total length of the engagement press should be between 2 turns (helix angle 2 x 360 degrees) and 5 turns. The convex portion and/or the concave portion of the corrugated pipe are engaged and pressed, more preferably for 3 to 4 times. At this time, the engagement and pressing directions of each endless belt with respect to the corrugated pipe may be the same direction, or may be carried out alternately in opposite directions. Of course, the engagement and pressing by each of these endless belts may be performed not only from the first winding but also after the first two to three turns. Note that when the overlapping portion is along a concave portion, it is desirable to determine the cross section of the endless belt so that the overlapping portion can be directly pressed.

Since each of the endless belts configured as described above comes into contact with the high-temperature synthetic resin, albeit slightly, in a molten state, it is desirable that the endless belt has heat resistance in addition to its original toughness and flexibility. A specific example of the material is a cloth laminated with rubber, and heat-resistant rubber is particularly used as the rubber. Of course, such an endless belt is preferably cooled by cold water, cold air, or the like.

Examples of other endless belt materials include hard rubber, synthetic resin, leather, and metals such as aluminum and aluminum alloys.

In this invention, a cylindrical mandrel is used to continuously feed a corrugated tube in one direction by winding a synthetic resin strip supplied in a molten state from an extruder in a spiral manner so as to overlap a portion of the synthetic resin strip. . Therefore, in a cylindrical mandrel, a large number of rotors are rotatably supported obliquely (obliquely 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 parallel to each other and diagonal (
relative to the imaginary cylindrical axis of the mandrel). Furthermore, if the cylindrical mandrel itself does not have the function of feeding the corrugated pipe in one direction, the mandrel itself can be moved laterally in the axial direction with a rail, etc., or the mandrel can be fixed and the synthetic resin extruder can be moved with a rail, etc. It may also be moved laterally.

Furthermore, according to another aspect, the present invention provides a corrugated pipe itself having a specific configuration.

That is, the corrugated pipe is made by winding a synthetic resin strip in a spiral shape, and inserting a flexible reinforcing material or defining a reinforcing space inside or on the back surface of the strip along the longitudinal direction of the strip. This is a corrugated pipe with protrusions formed on its surface. During manufacturing, this corrugated pipe is engaged and pressed by a plurality of endless belts intermittently every 1/4 to 172 turns of the corrugated pipe, so that the strips are overlapped. Pressure bonding of the mating portions and formation of the protruding portions are sufficiently performed, and therefore it can be suitably used as a drain pipe that requires particularly strong toughness.

(e) Examples The apparatus of the present invention will be described in detail below based on specific examples shown in the drawings. Note that this inventive device is not limited by this.

First, in FIG. 1, a corrugated pipe continuous manufacturing apparatus 1 includes a synthetic resin extruder 12 that continuously extrudes a synthetic resin strip A in a molten state, and a synthetic resin tubular body 8 as a flexible reinforcing material. A reinforcing material extrusion t13 to be extruded, a rotating mandrel 4 that helically overlaps and winds the belt-like body A and the tubular body B supplied from both of these extrusion racks to continuously form a helical tube C, and the resulting helical tube. It mainly consists of a set 5 of endless belts for pressing and joining the overlapping portions of C and shaping a spiral convex strip, which will be described later.

The rotating mandrel 4 has multiple hollow shafts 6.7...
・ are arranged in parallel at predetermined intervals along the circumferential surface of one virtual cylinder, and each hollow shaft has a shaft end (not shown).
A chain is attached to a sprocket provided on the sprocket (on the left in FIG. 1) so that the sprocket rotates in the same direction at a constant speed, thereby substantially rotating the rotating mandrel 4.

In the set of endless belts 5, for example, one of the endless belts 5x has a cross section corresponding to the cross-sectional shape of the spiral groove E (described later) of the spiral tube C to be obtained, and the rollers 8x
,9. It is movably supported by x and iox. Here, the rollers 8x and 10X are rotatably supported by common roller shafts sz and ioz, respectively, and the roller 9x is supported so as to be movable left and right by an independent roller shaft 9xz, thereby reducing the pressing force of the belt against the spiral tube C. Allows adjustment. That is, especially in FIG. 2, the independent roller shaft 9xz of the roller 9x is rotatably supported approximately at the center of the arm 11x, the upper end of which is bolted to the tip of the bolt 13x, and the lower end is connected to the fixed shaft 12X. Bins are combined. And bolt 13x fixes the rear plate 14x
It is positioned so that it can move left and right using FJI adjustment nuts 15x and 16x.

Note that the other endless belts 5y... are connected to the endless belts 5X by means of independent roller shafts (not shown).
It has the same spherical configuration as the endless belt 5x, except that it is supported so as to be movable left and right separately from the independent roller shaft 9xz, and its explanation will be omitted.

Next, a corrugated pipe continuous manufacturing apparatus 1 having the above configuration
The operation will be explained based on the first to third factors, and the continuous manufacturing method of corrugated pipes will be explained accordingly.

When the rotating mandrel 4 is rotated (substantially) and the molten polyethylene resin strip A is supplied from the synthetic resin extrusion R2 around the rotating mandrel 4, the strip is spirally wound to form a spiral tube. form C. Further, when the strip A is wound, a polyethylene resin tubular body B is supplied from the reinforcing material extruder 3 to the back side of the strip along the longitudinal direction of the strip A. In this way, the spiral convex stripes as convex portions are formed on the surface of the helical tube C, and the appearance of the corrugated tube F is substantially arranged.

Further, the above-mentioned spiral tube C is formed by overlapping a part of the band-like body A to be wound later on the previously-wound part of the band-like body A, and this overlapping part is the part of the endless belt. Each belt of set 5 sequentially presses each belt approximately every 1/2 turn, thereby joining them. Normally, the speed at which the belt-like body A and the tubular body B are pulled by the rotation of the rotating mandrel 4 is faster than the speed at which they are extruded, and the object is still in a soft state, and furthermore, it gradually becomes harder after being extruded. Therefore, the joining of the overlapping portions of the above-mentioned strips is often insufficient. Conventionally, a pressure roller or an endless belt is used to press the overlapping parts, but since the pressing force is uniform and the pressing time (or distance) is instantaneous or continuous for a long time, Depending on the condition of the resin, the effect may not be sufficient. However, according to the intermittent compression by each belt of the endless belt set 5, that is, the intermittent compression of approximately 0.5 revolutions of helical rotation (approximately 360×O, 5 degrees), the overlapping portions cannot be joined. is carried out intermittently by separate endless belts 5X, 5y, etc., so that the pressing force at each stage of the axial movement of the corrugated pipe can be adjusted while applying sufficient FftM to press and join the band-shaped bodies. For soft areas, the pressing force is relatively small (but for hard areas, it is relatively large)
Regardless of whether the synthetic resin is soft or hard, corrugated pipe jointability is fully guaranteed. In addition, the cross section of the endless belt 5 has spiral grooves (
Since the corrugated groove corresponds to that of a groove (concave groove), a corrugated INF having a desired shape, that is, a desired pressure resistance strength as shown in FIG. 3 can be obtained. In particular, the rotation of the rotating mandrel 4 puts the molten band A and the tubular body B in tension immediately after extrusion, so that, for example, the tubular holiday becomes flattened in a direction parallel to the rotation axis of the rotating mandrel 4. However, by adjusting the pressing force and shaping action of belt 5x of 115 of the endless belt described above, the cross section of tubular body B is maintained in a predetermined perfect circular shape, and the desired shape is achieved. Compressive strength can be obtained.

Here, the pressing force of each coarse belt of each endless belt, for example belt 5x, against the corrugated pipe is determined by adjusting nut 15x in FIG.

By adjusting the tightening position of 16X, bolt 13x
can be moved almost horizontally left and right, thereby adjusting the strength or weakness. Note that the through hole of the fixing plate 14X through which the bolt 13X passes is a long hole that is long in the vertical direction.

Furthermore, if the endless belt set 5 is made up of four endless belts as shown in Fig. 1 instead of the conventional single endless belt, assuming that the pressing time is the same, then
At least the time each endless belt is exposed to high temperatures can be reduced to about 1/4, and the life of each endless belt can be extended.

Unlike the above example, the manner in which the strips are superimposed and the tubular body is interposed between these strips can be changed as shown in FIG. 4. In other words, the band-like body Aa has one width and covers the two-wound tubular bodies 13a and 3a from the outside (hereinafter, different embodiments with corresponding configurations will be described with reference numerals a, b, (The description may be omitted and the description may be omitted.)

Next, the spiral tube as described above can also be constructed into a double tube structure. In other words, the corrugated pipe continuous manufacturing apparatus 1b shown in FIG. 5 includes two synthetic resin tubular bodies 2b, 2''b,
Furthermore, two sets of endless belts 5b and 5'b are provided. As shown in FIGS. 5 and 6, a molten polyethylene resin strip A'b is first supplied from the extruder 2'b around the rotating mandrel 4b, and the strip is spirally wound to form a spiral tube C. 'b is formed. And this spiral tube Q'
b is a pipe having no spiral concave or convex ridges at all, and its spiral overlapping portion is pressed by each endless belt (approximately rectangular in cross section) of the endless belt set 5-b similar to Figs. 1 and 2. , thereby ensuring the bond. Next, on the obtained spiral tube C'b, as in FIGS.
b and the tubular body Bb are overlapped. Although the explanation is omitted, the obtained corrugated pipe Fb has a double pipe structure as shown in FIG. Note that Gb and Gb are the overlapping portions of the strips A' and b.

Unlike each of the above-mentioned pieces, a synthetic resin tubular body may be inserted into the inside of the band-shaped body and wound spirally. That is, in FIG. 7, a synthetic resin tubular body 3c is inserted into the synthetic resin strip AC in a molten state, and is spirally wound around a rotating mandrel (not shown) to form a spiral tube.

Then, the overlapping portion Gc of the belt-like body AC is pressed and joined by the endless belt 5xc shown by the dashed line, and the spiral convex line Dc of the belt-like body AC is shaped. In addition, the band-shaped body A
C is obtained by feeding the previously molded tubular body Bc into a synthetic resin extruder and extruding it together with the molten synthetic resin from an extrusion nozzle while maintaining the tubular body Bc in the center. Of course, the opening of the extrusion nozzle is formed into a substantially inverted T-shape in cross section corresponding to the cross section of the strip AC.

Furthermore, the MA tube as described above can be placed over (on the outside of) the inner spiral tube as shown in FIGS. 4 and 6 to form a double structure as shown in FIG. 8.

Examples of other cross-sectional structures of corrugated pipes are listed below.

FIGS. 9 to 11 FIG. 9 shows an example in which a flexible reinforcing material Be such as hard vinyl chloride resin is inserted into the back surface of the strip along the longitudinal direction of the strip. Note that the example in FIG.
The overlapping portion Gf of f is structured in a stepped manner, and FIG. 11 is characterized in that the flexible reinforcing material B (l is structured to have a square cross section).

12-14 and 15-17 The cross-sectional structure of the strip consists of an inverted U-shaped piece Hh and large and small horizontal pieces 1h and Jh extending horizontally outward from both ends of this piece, and the two pieces are joined at a spiral concave bottom. , the small horizontal piece Jh, and the tip of the large horizontal piece 1h are overlapped and joined by an endless belt (not shown) as appropriate. 15 to 17 show three examples in which the cross-sectional structure of the strip is different from the above.

18 to 20 and 21 to 27 show that the cross-sectional structure of the strip is composed of an inverted U-shaped piece H42 and one end of this piece (
It consists of a hard piece part consisting of a horizontal piece JO extending horizontally outward from the right end and an inclined piece Ig extending slightly downward from the other end, and a soft piece part KQ that closes the downward opening part of this hard piece part. 21 to 27 show examples in which the cross-sectional structure of the strip is slightly different from the above.

The belt-shaped body shown in FIG. 28 has a hollow part (L[) by profile extrusion. Further, in the corrugated pipe obtained here, the convex portion and the concave portion are both engaged and pressed by an endless belt (5Xt).

Unlike the above example, two flexible reinforcing materials are simultaneously inserted side by side inside or on the back side of one synthetic resin strip and wound spirally, thereby forming a corrugated pipe with two spiral ridges. You may.

(f) Effects of the Invention According to this invention, the convex portion or the concave portion of the corrugated pipe is engaged and suppressed intermittently every 1/4 to 1/2 circumference of the corrugated pipe using a plurality of specific endless belts. Therefore, it is possible to adjust the pressing force at each stage of the axial movement of the corrugated pipe while press-joining the strips for a sufficient amount of time. As a result, a corrugated pipe suitable as a drain pipe requiring particularly strong strength is obtained.

[Brief explanation of the drawing]

Fig. 1 is a perspective view illustrating the main functions of an example of the corrugated pipe manufacturing apparatus of the present invention, Fig. 2 is a diagram illustrating the configuration of the endless belt of the apparatus, and Fig. 3 is a main part of the corrugated pipe obtained by the apparatus. Department! 4 is a diagram equivalent to FIG. 3 showing another example, FIG. 5 is a diagram equivalent to FIG. 1 showing another example,
6 to 11 are views corresponding to FIG. 3 showing other examples, FIG. 12 is a partial side explanatory view of a corrugated pipe showing another example, and FIG. 13 is a longitudinal sectional view of the corrugated pipe. 1st
Figure 4 is an enlarged cross-sectional view of the main part of the vertical cross-sectional view, Figures 15-17 are views equivalent to Figure 14 showing still other examples, and Figures 18-20 are equivalent to Figures 12-14 showing still other examples. Figures 21-28
The figure is a diagram corresponding to FIG. 14 showing still another example. 1... Corrugated pipe continuous FA manufacturing equipment, 2...
...Synthetic resin extruder, 3.For reinforcing material extrusion, 4.Rotating mandrel, 5.Endless belt set, A.....
Band-shaped body, B...Flexible reinforcing material, C...
Spiral tube, D... Spiral convex line (convex part, F...
corrugated pipe. Figure 2 Figure 6 Figure 7 Figure 8 I:tI-1 Figure 9 Figure 10 Figure f Figure 11 Figure 12 Figure 14 Figure 17 Figure 20 Figure 21 Figure 23

Claims (1)

[Scope of Claims] 1. A synthetic resin extruder that extrudes a synthetic resin strip in a molten state, and a flexible reinforcing material made of the same or different synthetic resin as the synthetic resin from this extruder or another extruder, or A reinforcing material extruder that extrudes the molded flexible reinforcing material and a synthetic resin extruder are used to spirally wind the strips.
A flexible reinforcing material from a reinforcing material extruder is supplied inside or on the back side of the strip along the longitudinal direction of the strip to form convex strips on the surface of the strip. A rotating mandrel for forming a corrugated pipe having a convex portion on the surface by overlapping a part of the part of the band-shaped body to be wound later on the part, and a convex line while the corrugated pipe is held on this mandrel At least 1/4 of the corrugated pipe is attached to the concave portion formed between the sections and/or the convex portions thereof.
A corrugated pipe manufacturing device comprising a plurality of endless belts that are sequentially and intermittently engaged every 1/2 turn to press the overlapping portions of corrugated pipe strips. 2. A synthetic resin extruder that extrudes a molten synthetic resin strip so that its cross section becomes curved or hollow; and a synthetic resin extruder that extrudes a molten synthetic resin strip so that its cross section becomes curved or hollow. A reinforcing space is defined inside or on the back side along the longitudinal direction of the strip, and a convex strip is formed on the surface.
A rotating mandrel for forming a corrugated tube having a convex portion on the surface by overlapping a part of the band-shaped body to be wound later with a part of the band-shaped body wound earlier, and a corrugated tube on the mandrel. While being held, the convex portion and/or
Or, intermittently engages with the concave portions formed between the convex portions at least every 1/4 to 1/2 circumference of the corrugated pipe, and presses the overlapping portion of the band-like body of the corrugated pipe. Corrugated pipe manufacturing equipment consisting of multiple endless belts.