JP3297723B2 - Rigid synthetic resin pipe and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard synthetic resin pipe mainly used as an electric wire protection pipe, a water pipe, a sewage pipe, a culvert pipe and the like buried and used inside and outside a building or under the ground, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a rigid synthetic resin pipe which is used as an electric wire protection pipe or a water and sewage pipe, in which a pipe wall is formed in a spiral uneven wave shape, is already well known in general. ing. On the other hand, in a tube suitable for use mainly as a blower for a futon dryer for home use, it is a synthetic resin tube having a small uniform wall thickness of 1 mm or less and a small diameter of about 30 to 40 mm. The cross-sectional shape of the tube wall is substantially triangular, and one of the inclined walls can be changed to a shortened posture substantially parallel to the other inclined wall, so that the shortened posture can be held by itself. Annular bellows tubes have also been proposed.

[0003]

In the former conventional electric wire protection pipes, water supply and sewage pipes, etc., the wall thickness of the pipe wall is reduced due to the irregular wall shape of the pipe wall as described above. Even relatively thick ones have some flexibility and are conveniently used. However, conventional synthetic resin pipes used for water and sewage pipes of this type cannot be reduced in length in the axial direction, and require a bulky storage space during storage. Since long items cannot be transported due to problems such as road conditions, they must be transported after being cut to a predetermined length. In particular, large-diameter pipes having an inner diameter of 1000 mm or 3000 mm or more cannot be transported unless they are cut into lengths corresponding to the length of the carrier of the transport truck, and therefore, a large cost for transport. In addition to this, not only that, but also pipes that have been cut short for transportation during use must be connected and connected one by one using a pipe joint, so that this connection connection requires a great deal of time and effort. Needed time and.

In such a conventional synthetic resin tube, since the tube wall is formed in a corrugated shape, even if it has a certain degree of flexibility, it exceeds the allowable range of the flexibility. Since it cannot be bent at a sharp angle, the radius of curvature cannot be reduced.For example, when laying water and sewage pipes, it is often difficult to bend pipes along the topography or land boundary. For example, in the case of pipes for electric wire protection pipes, sharply bent pipes cannot be formed in the bent pipes from the building wall to the ceiling or in the corner pipes in the ceiling. Had the major problem of having to do so.

Therefore, an object of the present invention is to solve the problems of such a conventional synthetic resin tube,
Focusing on the latter technique of the small diameter pipe having a thinner wall as shown in the section of the prior art, and adopting a completely new pipe structure, the pressure-resistant deformation of the conventional hard synthetic resin pipe has Although the tube has the same strength as that of the conventional tube, the length of the tube during storage and transportation is almost the same as that of the conventional tube. Hard synthetic resin that is long and at least twice as long, reduces the number of connecting and connecting points to less than half that of conventional ones, and enables sharply bent piping with a small radius of curvature if necessary. It is intended to provide a tube and a method for manufacturing the tube.

[0006]

The structure of the present invention for achieving the above object will be described with reference to the reference numerals used in the embodiments. The rigid synthetic resin pipe according to the present invention has a substantially sectional shape. The adjacent two inclined walls 2 and 3 constituting the triangular or trapezoidal tube wall 1 are formed into a V-shaped or substantially V-shaped cross section.
It is assumed to be continuously continuous in the shape of a letter,
On one of the side and the valley 5 side, a thick portion a having a thicker cross-sectional shape is fitted into the fitting groove b and fitted to be swingable in the axial direction of the tube wall 1. The bent corner of the tube wall 1 continuous in the cross-sectional shape V-shape or substantially V-shape or a portion near the bend is one of the crest 4 side and the valley 5 side of the tube wall 1,
One inclined wall 2 is locally formed in the thin portion d, and transitions in a direction in which one inclined wall 2 approaches the other inclined wall 3 beyond the center line s passing through the thick portion a or the thin portion d on the peak portion 4 side. In addition, the structure is such that the approach posture can be held by itself.

[0007] In addition, in the case of a pipe structure such as an underground pipe that requires particularly watertightness, both inclined walls 2 and 3 have a thick wall portion a.
May be connected by a soft synthetic resin strip 6 on the inner peripheral surface near the peak 4 side or on the outer peripheral surface near the valley 5 side where the fitting groove b is fitted and connected. Thick part a and fitting groove b
Between soft synthetic resin material and other sealing material 7
May be interposed. A pipe structure suitable for water and sewer pipes and other fluid transport pipes is a structure in which an inner layer 8 made of a soft synthetic resin is integrally formed on the inner peripheral surface side of the valley portion 5 of the inclined walls 2 and 3. If necessary, a structure having the outer layer 9 formed on the outer peripheral surface side or a structure having the inner and outer layers 8 and 9 formed thereon may be employed.

Further, as a method of manufacturing a rigid synthetic resin pipe having such a structure, the shape of a band-shaped material A for forming the pipe wall 1 is V-shaped or substantially V-shaped in cross section. One end is formed in a thick portion a, the other end is formed in a fitting groove b which is fitted with the thick portion a, and a V-shaped bent corner c or a portion near the bent portion c is locally thinned. d, and the adjacent thick portion a on one end side and the fitting groove b on the other end side are fitted to each other while spirally winding the strip-shaped material A, and the fitted thick Part a into fitting groove b
The belt-shaped material A is fitted and connected to be able to swing in the width direction within a predetermined angle range.

[0009]

The rigid synthetic resin tube according to the present invention has the above-mentioned structure. Therefore, during storage or transportation, the tube is pressed and compressed in the axial direction. As shown in the drawing, each one of the inclined walls 2 is positioned so as to approach the other inclined wall 3 over the center line s passing through the thick portion a or the thin portion d on the peak portion 4 side. To a shortened state. Once in such a shortened state, the tube maintains this shortened state even when the pressing force is removed. Store or transport in this way, when used after transport, hold both ends of the pipe and pull in the axial direction of the pipe,
Each one inclined wall 2 is separated from each other inclined wall 3 beyond the center line s, and the other inclined wall 3 is separated.
Is restored so as to have a different inclination angle posture from that of the above, and is in the extended state. Once in this stretched state, the tube will maintain this stretched state even when the pulling force is removed. As in the conventional case, the pipes thus extended are sequentially connected and connected at their pipe ends by pipe joints, and are appropriately piped. Further, in a place where a sharply bent pipe is required, the required bending can be performed by setting only the required number of one inclined walls 2... Piping can be done as posture.

Therefore, the rigid synthetic resin pipe according to the present invention is:
In using the pipe, the pipe can be used as a pipe having a length at least twice as long as the pipe at the time of transportation. As a result, not only storage costs and transportation costs can be significantly reduced, but also the number of connecting and connecting points of the pipes is reduced to at least a half of the conventional one.
It can be reduced to the following.Furthermore, it is not necessary to connect and connect using a elbow-shaped pipe joint even in a place where a sharply bent pipe with a small radius of curvature is required, and the pipe itself is bent at a sharp angle. Since piping can be performed, labor and time for piping can be significantly reduced, and piping efficiency can be significantly improved.

In manufacturing such a tube,
By fitting the thick portion a formed on one end side of the strip-shaped material A with the fitting groove b formed on the other end side, it is possible to manufacture the belt-shaped material A very efficiently.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing a first embodiment of the present invention. FIG. 1 shows an embodiment structure of a tube in which a cross-sectional shape of a tube wall 1 is triangular. The shape of the strip material A for forming the tube wall 1 is formed in a V-shaped cross section using a hard synthetic resin material, and as shown in the left end of FIG.
One end is formed in a thick portion a having an arc cross section,
A fitting groove b having an arc-shaped cross section for fitting the other end to the thick portion a.
And the V-shaped bent corner portion c is locally formed in the thin portion d, and the width of one inclined portion 2a forming the V shape is slightly smaller than the width of the other inclined portion 3a. A strip having a short width is formed, and the strip-shaped material A is wound so that the bent corner portion c is located on the valley portion 5 side of the tube wall 1 while being spirally wound. a
And the fitting groove b on the other end side are fitted to each other, and the fitted thick portion a is inserted into the fitting groove b within a predetermined angle range in the width direction of the band-shaped material A, that is, in the axial direction of the pipe. Are fitted and connected so as to be swingable.

The structure of the tube thus formed is such that the cross-sectional shape of the tube wall 1 is triangular, and the two adjacent inclined walls 2 and 3 constituting the tube wall 1 are integrated at the valley 5 side of the tube. The thick portion a having a V-shaped cross-section and having a thick cross-sectional shape at the peak portion 4 of the tube wall 1 is fitted into the fitting groove b to form the tube wall 1. The valley portion 5 is locally formed in the thin portion d, and one of the valley portions 5 with respect to the center line s in the pipe circumferential direction passing through the thick portion a (FIG. 2). In FIG. 2, the opening angle α of the inclined wall 2 is formed at a steep angle slightly smaller than the opening angle β of the other inclined wall 3 (the left side in FIG. 2), and the width of the one inclined wall 2 is set to the other. Is formed to be slightly shorter than the width of the inclined wall 3, and extends beyond the center line s passing through the thick portion a on the peak portion 4 side. The one inclined wall 2 is the other inclined wall 3
, And a structure capable of self-holding the approaching posture as shown in FIG.

Since the rigid synthetic resin pipe shown in this embodiment has such a structure, when storing and transporting the pipe, the pipe is added in the axial direction as described in the above-mentioned section of operation. Compress and compress one inclined wall 2 to the other inclined wall 3
When laying or piping, it is possible to hold the both ends of the pipe and stretch it in the pipe axis direction to restore it to the normal posture and use it in a long state.

The pipe of the second embodiment shown in FIG. 4 is an embodiment of a pipe in which the cross section of the pipe wall 1 is trapezoidal, and the cross section of the strip material A is shown on the left side of the figure. like,
A top side e extending in the lateral direction with a top portion connected in a V-shape in an inverted V shape
And a corner portion between the top side e and the one (right side in the figure) inclined portion 2a is locally formed as a thin portion d.
A thick portion a is formed at the tip of the inclined portion 2a, and a fitting groove b is formed at the tip of the other inclined portion 3a. The pipe is wound spirally to form a pipe having a structure in which the peak 4 of the pipe wall 1 is flat and the thick part a and the fitting groove b are fitted in the valley 5. In this manner, one (the right side in the drawing) inclined wall 2 can move closer to the other inclined wall 3 beyond the center line s passing through the thin portion d on the peak portion 4 side. Things.

The pipe of the second embodiment has two inclined walls 2,
At the outer peripheral surface side portion near the valley portion 3, the adjacent two inclined walls 2 and 3 are bonded and connected in a bridging manner at both side edge portions of the thin soft synthetic resin strip 6, respectively. By doing so, the uncertainty of the watertightness at the fitting portion of the valley 5 is compensated for, and a watertight tube structure is obtained. Further, in the case of the pipe structure shown in the first embodiment, the adjacent inclined walls 2 and 3 may be similarly bonded and connected in a bridge-like manner at the inner peripheral surface side portion of the peak portion 4.

The tube of the third embodiment shown in FIGS.
This is an example of a tube in which the cross-sectional shape of the tube wall 1 is triangular, and the cross-sectional shape of the band-shaped material A is a V-shaped cross-shaped material A in the first embodiment, as shown on the left side of FIG. Is formed in an inverted V-shape in which the upper, lower, left and right sides are symmetrical, and the band-shaped material A is spirally wound so that the crests 4 of the tube wall 1 are connected in an inverted V-shape. This forms a tube having a structure in which a is fitted to the fitting groove b. In this case as well, in the same manner as in each of the above-described embodiments, one of the inclined walls 2 (on the right side in the figure) crosses the center line s passing through the thin portion d on the mountain portion 4 side, and the other as shown in FIG. Can be moved closer to the inclined wall 3 side.

The strip-shaped material A shown in the embodiment is simultaneously extruded at the time of extrusion molding, and the inner surface of the fitting groove b on one end or the outer surface of the thick portion a on the other end, or a thin soft material on both surfaces thereof. The synthetic resin materials 7, 7 are integrally formed, and the soft synthetic resin material 7 is interposed in the fitting portion between the thick portion a and the fitting groove b. In a case where the pipe is used in a place such as an indoor place, such as an electric wire protection pipe where strict watertightness is not required, if the flexible synthetic resin material 7 is provided, the watertightness is sufficiently improved. Can be kept.

In the fourth embodiment shown in FIG. 7, one of the inclined portions 2a (the right side in the figure) of the inverted V-shaped strip A is locally thinned to a portion close to the V-shaped bent corner. d, and has a tube structure in which a thin-walled portion d is located near a peak 4 of one of the inclined walls 2 in the tube wall 1. In other respects, the structure is the same as that of the third embodiment.

The fifth embodiment shown in FIGS. 8 and 9 is an embodiment of a tube in which the cross-sectional shape of the tube wall 1 is trapezoidal. The cross-sectional shape of the strip material A is independent on the left side of FIG. As shown in the drawing, the V-shaped bottom portion has a side f extending in the lateral direction, and one (right side in the drawing) inclined portion 3a is formed in a substantially V shape having a side e extending laterally outward. Extended side e
A fitting groove b is formed at the tip of the one inclined portion 3a.
And a local thin portion d is formed at the corner of the side f extending to the bottom portion, and the thick portion a is formed at the tip of the other inclined portion 2a. The pipe structure has a flat, thick portion a and a fitting portion between the fitting groove b, and a valley portion 5 with a flat thin portion d.

In the pipe of this embodiment, an inner layer 8 made of a substantially straight tubular soft synthetic resin in a normal straight pipe posture is integrally formed on the inner peripheral surface side of the valley 5 of both the inclined walls 2 and 3. It is a double tube structure with an inner layer formed by connection. Such an inner layer 8
Is suitable for a pipe through which a fluid flows, and means for making a watertight state using the soft synthetic resin strip 6 shown in the second and third embodiments, It is possible to omit means for interposing the soft synthetic resin material 7 in the part to make it watertight.

The tube of the sixth embodiment shown in FIGS. 10 and 11 is a substantially V-shaped inverted substantially V-shaped cross-sectional shape of the substantially V-shaped strip material A shown in the fifth embodiment. The ridge 4 of the tube wall 1 is flat, the thin portion d is located near the ridge 4 of one (the right side in the figure) of the inclined wall 2, and the valley 5 is also flat and fitted with the thick portion a. This is a tube structure in which a fitting portion with the groove b is located.

The pipe of the sixth embodiment has an inner layer 8 similar to that shown in the fifth embodiment, and the outer peripheral surface of the ridge 4 is made of a substantially straight pipe made of a soft synthetic resin. It has a tubular structure with inner and outer layers formed by integrally connecting tubular outer layers 9. The pipe structure having such inner and outer layers 8 and 9 is particularly suitable for a pipe buried underground and through which a fluid flows. In the drawing, g and h are stopper portions for regulating the spread angle and the narrowing angle of the inclined walls 2 and 3, respectively.

FIGS. 12 to 14 show another embodiment of the thin portion d. In the embodiment of FIG. 12, the portion near the valley 5 on the side of one inclined wall 2 is locally thinned. d
In the embodiment of FIG. 13, the portion near the valley 5 on the other inclined wall 3 side is locally formed in the thin portion d.
In the embodiment shown in FIG. 14, the portions of the two inclined walls 2 and 3 near the valley 5 are locally formed as thin portions d.

Although the embodiments which are considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments. For example, the thickness of one inclined wall 2 and the thickness of the other The present invention has the above-mentioned constitutional requirements such as giving a change to the thickness of the inclined wall 3 and achieves the object of the present invention, and is appropriately modified and implemented within a range having the following effects. Is what you can do.

[0026]

As is apparent from the above description, the invention of the manufacturing method according to the present invention is characterized in that the shape of the strip-shaped material for forming the pipe wall has a V-shaped or substantially V-shaped cross-section, One end is formed in a thick portion, the other end is formed in a fitting groove to be fitted with the thick portion, and a V-shaped bent corner or a portion near the corner is locally formed in a thin portion. While the band-shaped material thus formed is spirally wound, the adjacent thick portions and the fitting grooves are fitted to each other, and the fitted thick portions are within a predetermined angular range in the fitting grooves. In this case, there is an advantage that the pipe can be manufactured very efficiently because it is fitted and connected so as to be able to swing in the width direction of the belt-shaped material, and a part of the belt-shaped material is overlapped with each other. As in the case of fusing or bonding with an adhesive, There is an advantage that the rigid synthetic resin material for forming the tubular material is not limited to a material having good fusibility or a good adhesive property, and there is an advantage that there is no limitation on the material. Does not need to be performed immediately after the extrusion of the band-shaped material, and can be manufactured using the band-shaped material formed in advance, so that there is an advantage that the production of the tube is not restricted in time and place.

In the pipe structure according to the present invention, a fitting portion formed by a thick portion and a fitting groove is provided in one of the crest portion and the trough portion forming the tube wall. A structure in which one inclined wall can be shifted in a direction approaching the other inclined wall by allowing a relative angle to be changed and a thin portion provided on the other to bend, and the approach posture can be held by itself. Therefore, during storage and transportation of the pipe, the pipe is pressurized and compressed in the axial direction, and each of the inclined walls is shifted so as to be in a posture close to the other inclined wall. By shortening the tube, the length of the tube can be shortened to at least a half or less of the normal length, so that the storage space can be small and a large amount of tubes can be stored. Normal 2
Transport of pipes that are more than twice as long is possible.

Further, the pipe transported in the shortened state is restored to a length at least twice as long as the shortened state by pulling both ends of the pipe toward the pipe axis direction at the time of laying or piping. As a long, regular-shaped pipe, the pipe ends can be sequentially connected and connected by a pipe joint and piped as appropriate, as in the conventional case, and furthermore, where a pipe with a steep angle is required, it is located on the small diameter side. By setting only a required number of one inclined walls in a shortened posture close to the other inclined wall, piping can be performed in a required bending posture. As a result, not only the storage cost and the transportation cost can be significantly reduced, but also the connecting point of the pipe can be reduced to at least a half or less of the conventional pipe when connecting the pipe. There is no need to connect and connect using elbow-shaped pipe joints even in places requiring sharply bent pipes with small radii.Because pipes can be bent at sharp angles, piping work and time can be reduced. Can be greatly reduced, and a remarkable effect that could not be expected at all with the conventional synthetic resin pipe that the pipe efficiency can be greatly improved can be expected. is there.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a first embodiment of the present invention.

FIG. 2 is a sectional view of the pipe wall portion.

FIG. 3 is a sectional view of the shortened posture.

FIG. 4 is a sectional view of a tube wall portion showing a second embodiment.

FIG. 5 is a sectional view of a tube wall portion showing a third embodiment.

FIG. 6 is a sectional view of the shortened posture.

FIG. 7 is a sectional view of a tube wall portion showing a fourth embodiment.

FIG. 8 is a sectional view of a tube wall showing a fifth embodiment.

FIG. 9 is a sectional view of the shortened posture.

FIG. 10 is a sectional view of a tube wall showing a sixth embodiment.

FIG. 11 is a sectional view of the shortened posture.

FIG. 12 is a cross-sectional view of a tube wall showing another embodiment.

FIG. 13 is a cross-sectional view of a tube wall showing another embodiment.

FIG. 14 is a cross-sectional view of a tube wall showing another embodiment.

[Explanation of symbols]

 (1) Pipe wall (2) Inclined wall (3) Inclined wall (4) Crest (5) Valley (A) Strip-shaped material (2a) Inclined portion (3a) Inclined portion (a) Thick portion (b) Fit Groove (c) Bent corner (d) Thin part (s) Center line

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ identification code FI B29L 23:18 B29L 23:18 (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 63/00-65/82 B29C 53/00-53/84 F16L 9/00-11/26

Claims (8)

(57) [Claims] 1. A tube in which a cross section of a tube wall (1) is formed in a substantially triangular or trapezoidal shape by a band-shaped material made of a hard synthetic resin, and two adjacent tubes forming the tube wall (1) are provided. Inclined wall
(2), (3) are integrally continuous in a V-shaped or substantially V-shaped cross-section, and at one of the ridge (4) side or the valley (5) side of the pipe wall (1), A thick portion (a) having a thick cross-sectional shape is fitted into the fitting groove (b) and fitted so as to be swingable in the axial direction of the pipe wall (1), and the V-shaped cross-sectional shape is formed. Alternatively, the bent corner of the pipe wall (1), which is continuous in a substantially V-shape, or a portion near the bent corner is the peak (4) side or the valley (5) of the pipe wall (1).
On the other side, one is formed beyond the center line (s) which is locally formed in the thin portion (d) and passes through the thick portion (a) or the thin portion (d) on the peak (4) side. Slope wall (2) is the other slope wall (3)
A rigid synthetic resin tube that moves in the direction of approaching and is capable of self-holding the approaching posture. 2. A thick portion on the side of the ridge (4) of each of the inclined walls (2) and (3).
The rigid synthetic resin pipe according to claim 1, wherein a fitting portion between (a) and the fitting groove (b) is formed. 3. A thick portion on the side of the valley (5) of each of the inclined walls (2) and (3).
The rigid synthetic resin pipe according to claim 1, wherein a fitting portion between (a) and the fitting groove (b) is formed. 4. An inner layer (8) made of a soft synthetic resin is integrally connected to an inner peripheral surface of a valley (5) of each of the inclined walls (2) and (3). Hard synthetic resin pipe. 5. An outer layer (9) made of a soft synthetic resin is integrally formed on an outer peripheral surface side of a ridge (4) of both inclined walls (2) and (3). Hard synthetic resin tube. 6. A spiral corrugated tube in which a cross-sectional shape of a tube wall (1) is formed into a substantially triangular or trapezoidal shape by winding a band-shaped material made of a hard synthetic resin in a spiral shape. The cross-sectional shape of the belt-shaped material (A) forming 1) is V-shaped or substantially V-shaped, one end of which is formed as a thick portion (a), and the other end is fitted with the thick portion (a). Formed in the mating groove (b), and
The V-shaped bent corner portion (c) or a portion near the corner portion is locally made a thin portion (d), and the band-shaped material (A) is spirally wound and the adjacent thick portion (a) on the one end side is spirally wound. The mating groove (b) on the other end side is fitted with each other, and the fitted thick portion (a) is inserted into the fitting groove (b) within a predetermined angular range and the width of the band-shaped material (A). A method for manufacturing a rigid synthetic resin pipe fitted and connected so as to swing in a direction. 7. A fitting portion between the thick portion (a) and the fitting groove (b) is formed on a tube wall.
The method for producing a hard synthetic resin pipe according to claim 6, wherein the pipe is formed on the ridge (4) side of (1). 8. A fitting portion between the thick portion (a) and the fitting groove (b) is formed on a tube wall.
The method for producing a rigid synthetic resin pipe according to claim 6, wherein the pipe is formed on the valley (5) side of (1).