JPH05180377A - Pressure-resistant synthetic resin tube - Google Patents

Abstract

PURPOSE:To improve the piping efficiency by moving one inclined wall to be in proximity to the other inclined wall over a center line through a support point at a peak part, and self-holding this proximate attitude. CONSTITUTION:For storage or transport of a tube 1, the tube is contracted toward an axial line under a pressure, so one inclined wall 3 is smoved to get in proximity to the other inclined wall 4 over a center line S through a support point P at a peak part 2 to get into a contraction condition. In the meanwhile, for usage, both ends of the tube are held to be pulled toward the outer side in the axial direction, so one inclined wall 3 gets apart from the other inclined wall 4 to be restored to take a different inclination attitude from that of the other inclined wall 4, and it is used as it is long. Labor and time required for piping can thus be reduced, thereby the piping efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-resistant synthetic resin pipe mainly used as an electric wire protection pipe, a water and sewer pipe, an underdrain pipe, etc., which is used by being buried in the ground.

[0002]

2. Description of the Related Art A synthetic resin pipe excellent in pressure resistance and flatness, which has been conventionally used as an electric wire protection pipe, a water and sewer pipe, etc., and whose pipe wall is formed in a spiral corrugated shape,
It is already well known to the general public. On the other hand, a relatively flexible synthetic resin tube having a small uniform wall thickness of 1 mm or less and a small diameter of 30 to 40 mm or less, which is mainly used as a blower tube for a domestic futon dryer. In the tube suitable for, the cross-sectional shape of the tube wall can be changed to a substantially triangular shape, and one inclined wall can be changed to a contracted posture along substantially parallel to the other inclined wall. A tube that can be held by itself has already been proposed.

[0003]

In the former conventional pressure-resistant synthetic resin pipes used for electric wire protection pipes, water and sewer pipes, etc., the pipe wall is formed in a corrugated shape as described above. Therefore, even if the wall thickness of the pipe wall is relatively large, it has some flexibility and is used conveniently. However, in the conventional pressure-resistant synthetic resin pipes used for this kind of water and sewer pipes, etc., the length in the axial direction cannot be reduced, so that it is bulky during storage and requires a large storage space. Due to problems such as road conditions, it was not possible to transport long ones, and it had to be cut into a predetermined length for transportation in consideration of problems such as road conditions. In particular, large diameter pipes with an inner diameter of 1,000 mm, 3,000 mm or more can be transported unless they are cut into lengths corresponding to the length of the cargo bed of the transportation truck. Therefore, it requires a great deal of cost for transportation, and not only that, but at the time of use, short cut pipes must be connected and connected by using pipe fittings so as to keep a complete water-stop state. Therefore, this connection and connection requires a great deal of labor and time.

Further, in such a conventional pressure-resistant synthetic resin pipe, although it has some flexibility only because the wall of the pipe is formed in a corrugated shape, it exceeds the allowable range of flexibility. Since it cannot be bent at a steep angle, the radius of curvature cannot be reduced. For example, when laying water and sewer pipes, it is often difficult to bend the pipes along the boundaries of the terrain or land. For example, in the case of electric wire protection pipes, it is not possible to bend pipes from the building's building wall to the ceiling or sharply bend pipes in the corner pipes in the ceiling. It had a big problem that it had to be connected.

Therefore, the present invention is directed to the invention of such a conventional pressure-resistant synthetic resin pipe, and an object thereof is to solve the problems that the conventional pipe has. In the latter case, focusing on the technical idea of expansion and contraction in a thin-walled small-diameter pipe, a pipe having a pressure deformation strength substantially equal to the pressure deformation strength of the conventional synthetic resin pipe was obtained by a completely new development concept. However, even though the length of the pipe is the same as that of the conventional pipe during storage and transportation, at least twice the length of the conventional pipe is required during use. Can have
An object of the present invention is to provide a synthetic resin pipe in which the number of connecting and connecting points is reduced to one half or less and abruptly bent pipes having a small radius of curvature can be used if necessary.

[0006]

The structure of the present invention for achieving the above object will be described with reference to the reference numerals of the drawings corresponding to the embodiments. The synthetic resin pipe referred to in the present invention has a pipe wall 1 Has a substantially triangular or trapezoidal cross section, and one of the inclined walls 3 and 4 forming the pipe wall 1 thereof has a portion 2a near the mountain top 2 of one inclined wall 3 and a valley bottom 5.
Alternatively, the portion 5a near the valley bottom 5 of the one inclined wall 3 is partially formed of a flexible resin material, and the other pipe wall portions are formed of a hard resin material. With the flexible resin material portion 2a near the mountain top 2 formed of a material as a fulcrum P, the one inclined wall 3 is the fulcrum P.
The structure is such that it moves beyond the center line s passing through to approach the other inclined wall 4 and approaches the other inclined wall 4 to maintain its approaching posture.

In forming the pipe according to the present invention, the length of the slanted wall 3 (one slanted wall 3) which moves beyond the center line s is longer than that of the other slanted wall 4. If the inclination angle α with respect to the center line s of the one inclined wall 3 is made smaller than the inclination angle β with respect to the center line s of the other inclined wall 4, one of the inclined walls 3 is formed. There is an advantage that it is easy to move the inclined wall 3 above to the other inclined wall 4 side beyond the center line s. Further, as a pipe structure suitable for water supply and sewer pipes and other fluid transport pipes, a structure in which an inner layer 6 made of a soft resin is integrally formed on the inner peripheral surface on the valley bottom side of the pipe wall may be used. In this case, the outer layer 7 may be formed on the outer peripheral surface of the pipe wall on the mountain top side, or the inner and outer layers 6 and 7 may be formed. It should be noted that the resin material referred to in the constituent features of the present invention is meant to include rubber materials such as natural rubber and synthetic rubber.

[0008]

The pressure-resistant synthetic resin pipe according to the present invention has such a structure, and therefore, during storage or transportation, the pipe is pressed and compressed in the axial direction so that one of the above Center line s passing through each fulcrum P of the inclined wall 3 of
.. and the other inclined walls 4 ... Once in this shortened state, the tube retains this shortened state even if the pressing force is removed. In this way, the pipe is stored or transported, and at the time of use after transportation, both ends of the pipe are held and pulled outward in the axial direction of the pipe so that each one of the inclined walls 3 ... The center line s passing through the fulcrum P is moved beyond the center line s and separated, and is restored so as to have a tilt angle posture different from that of the other tilted wall 4 ... Once
In this extended state, the tube retains this extended state even if the pulling force is removed. The pipes thus extended may be piped appropriately by sequentially connecting and connecting the pipe ends with pipe joints as in the conventional case. Further, in a portion that requires a steep angle pipe, only one inclined wall 3 ... of a required number or required length portion located on the small diameter side is in a reduced posture in which it is brought close to the other inclined wall 4. , Can be piped as the required bending posture.

Therefore, the pressure-resistant synthetic resin pipe of the present invention can be used by being used as a pipe having a length of at least twice the length of the pipe during transportation. As a result, not only can storage and transportation costs be significantly reduced, but the number of connecting and connecting points of pipes can be reduced to at least one-half or less.
Furthermore, since it is not necessary to connect and connect using an elbow-shaped pipe joint even in a place where a sharp-angled bent pipe with a small radius of curvature is required, the pipe itself can be bent and piped. The labor and time can be significantly reduced, and the piping efficiency can be significantly improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, FIGS. 1 to 3 are views showing a first embodiment of the present invention, and FIG. 1 is a partial cross-sectional view of a spiral tube in which a tube wall 1 has a substantially triangular cross-section. 2 and 3 show the enlarged sectional shape of the tube wall 1 portion. In this pipe, the peak 2 and the valley 5 where the two inclined walls 3 and 4 that form the pipe wall 1 intersect are made of a flexible synthetic resin material such as LDPE or soft PVC (soft in the following description of the embodiments). It is partially formed of synthetic resin material), and the other two inclined walls 3, 4 are all hard synthetic resin material of the same type that has good fusion bonding property with the soft synthetic resin material, for example, HDPE or hard PVC material. It is formed integrally with. Further, in the pipe of the embodiment, the length of one of the inclined walls 3 and 4 (the inclined wall on the right side in the drawing) 3 is shorter than the length of the other inclined wall 4. In addition, the inclination angle α of the one inclined wall 3 with respect to the center line s passing through the peak 2 is formed to be smaller than the inclination angle β of the other inclined wall 4 with respect to the center line s. .. Thus, in the pipe, one sloped wall 3 with the peak 2 formed of the soft synthetic resin material as the fulcrum P serves as the center line s passing through the fulcrum P as shown in FIG.
The structure is such that it can move in the direction of approaching the other inclined wall 4 beyond the above and can hold its approaching posture by itself.

As shown in the right side of FIG. 2, the main means for forming such a tube is as shown in the right side of FIG.
4, hard synthetic resin portions 3a, 4a forming a crest 4, a soft synthetic resin portion 2c forming a crest portion 2, and soft synthetic resin portions 5c, 5d forming a valley bottom portion 5 are formed into a series of strips having an inverted V-shaped cross section. As one, extrusion is carried out from one extrusion die in which two synthetic resin extruders are connected, and the soft synthetic resin portions 5c and 5d forming the valley bottom 2 are superposed on each other on the pipe forming machine and are spirally welded in sequence. It is wound around and formed.
This tube forming means may be carried out based on various known means already known.

Since the pipe shown in the embodiment has such a structure, as shown in the above-mentioned action, the pipe is pressed in the axial direction during storage or transportation. It is compressed, and one of the inclined walls 3 ... Is moved so as to be in a posture of approaching the other inclined wall 4 ,. Further, at the time of use, both ends of the pipe are held and pulled outward in the pipe axial direction, the one inclined wall 3 is separated from the other inclined wall 4, and the inclination angle posture different from that of the other inclined wall 4. It is restored so that it becomes long and used.

FIG. 4 to FIG. 8 are views showing a tube wall portion shown in different embodiments, respectively, in which the left half portion is in a long state and the right half portion is in a shortened state. Thus, in the embodiment shown in FIG. 4, in the sectional shape, one of the inclined walls 3 is shorter than the length up to the valley bottom 5, and the other inclined wall 4 is formed from the valley bottom 5 to the one inclined wall 3. The shape is such that it is slightly bent in a J-shape toward the side, and a soft synthetic resin material portion is formed in the peak portion 2 and the portion 5a near the valley bottom portion 5 of the one inclined wall 3.

In the embodiment shown in FIG. 5, contrary to the case of the above-mentioned embodiment, one sloped wall 3 is shorter than the length to the peak 2 in the cross-sectional shape, and the other sloped wall 4 is formed. On the mountain peak portion 2 side, a shape that is slightly bent in an inverted J shape toward the one inclined wall 3 side is adopted, and a soft synthetic resin material is formed on the portion 2a of the one inclined wall 3 close to the mountain peak portion 2 and the valley bottom portion 5. This is a structure in which parts are formed.

In the embodiment shown in FIG. 6, the structure of both the inclined walls 3 and 4 has a sectional shape in which one of the inclined walls 3 is a mountain top portion 2.
Side and the valley bottom 5 side are slightly shorter, and the other inclined wall 4 is a shape that is slightly bent in an S shape toward the one inclined wall 3 side on the mountain peak 2 side and the valley bottom 5 side. The soft synthetic resin material portion is formed in a portion 2a of the one inclined wall 3 near the peak 2 and a portion 5a near the valley bottom 5.

The embodiment shown in FIG. 6 has a soft synthetic resin inner layer 6 on the inner peripheral surface on the valley bottom 5 side of the pipe wall as a pipe structure suitable for a water transport pipe such as a water and sewer pipe. The structure is such that they are integrally formed, and further, both outer and inner layers 6 and 7 in which an outer layer 7 made of a soft synthetic resin is formed are formed on the outer peripheral surface of the pipe wall on the mountain top portion 2 side.

In the embodiment shown in FIG. 7, the pipe wall 1 has a trapezoidal sectional shape, and the structure of both inclined walls 3 and 4 is such that one inclined wall 3 has a mountain top portion in the sectional shape. 2 has a length slightly shorter than the length from the valley bottom 5 to the other, and the other inclined wall 4 has portions 4A and 4B which respectively project in the horizontal direction on the crest 2 side and the valley bottom 5 side. It has a Z shape, and the horizontal protruding portions 4A, 4
B forms a trapezoidal tube wall 1 with a horizontal peak 2 and a valley bottom 5, and a soft composite is formed at the corner of the sloped wall 3 on the peak 2 side and the valley 5 side. This is a structure in which a resin material portion is formed and both inclined walls 3 and 4 are connected in series. Further, the pipe of the embodiment has a structure in which an inner layer 6 made of a soft synthetic resin is integrally formed on the inner peripheral surface of the pipe wall on the valley bottom 5 side.

In the embodiment shown in FIG. 8, the tube wall 1 has a trapezoidal cross section as in the case of the embodiment shown in FIG. In terms of shape, the lengths of the crest 2 and the valley bottom 5 are approximately equal to each other, and these inclined walls 3 and 4 are formed on the crest 2 side and the valley bottom 5 side.
The side and the side are integrally connected by a short width soft synthetic resin material arranged horizontally. In addition, both inclined walls 3 and 4 in the embodiment
Is such that the length in the cross-sectional shape and the opening angle in the longitudinal direction in the tube axis direction are substantially equal. The inclined wall of the pipe in the present invention may have such a structure.

The synthetic resin material used for carrying out the present invention is not limited to the synthetic resin exemplified in the first embodiment,
Other synthetic resin materials may be used, for example, when HDPE is used as a hard material, EEA is used as a soft material,
It is conceivable to use EVA or to use TPR as a soft material when PP is used as a hard material. Further, as the hard resin material, a resin material reinforced with a fibrous reinforcing material such as glass fiber or carbon fiber may be used. In this case, in addition to the above-mentioned soft material, HDPE exemplified as a hard material can be used in combination in consideration of the wall thickness. In addition to synthetic resin materials, rubber-based resin materials may be used.

Although the examples considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these examples, and has the above-mentioned constitutional requirements referred to in the present invention, and The present invention can be carried out by appropriately modifying it within a range that achieves the object of the present invention and has the following effects.

[0021]

As is apparent from the above description, the present invention limits the pipe wall to a pipe whose cross-sectional shape is substantially triangular or trapezoidal, and the top of the pipe wall or the top of one of the inclined walls. The near portion and the valley bottom portion or the portion near the valley bottom portion of one of the inclined walls are formed of a partially flexible resin material, and the other pipe wall portions are formed of a hard resin material. Therefore, although the pressure-resistant flat strength of the pipe is not significantly reduced, the pipe can be used as a pressure-resistant pipe, but the flexible resin material portion at or near the peak is used as a fulcrum. The inclined wall of can be moved in the direction of approaching the other inclined wall by passing over the center line passing through the fulcrum part, and its approaching posture can be maintained by itself, so that it can be stored or transported / transported. Is usually at least 2 of length It can be shortened to a length of 1 or less, and can be used as a long pipe with a length at least twice the length during transportation by restoring the stretched state when used after transportation. That is, it has a remarkable effect that could not be expected with the conventional synthetic resin tube.

Therefore, the pipe of the present invention can significantly reduce the storage cost and the transportation cost, and at the time of use, can reduce the number of connecting and connecting points of the pipe by at least one-half or less. Furthermore, since it is not necessary to use an elbow-shaped pipe joint even in a place where a bent pipe with a small radius of curvature and a steep angle is required, the pipe itself can be bent for piping, so that labor and time for piping can be saved. Can be significantly reduced, and there is an advantage that the piping efficiency can be significantly improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway side 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 same shortened posture.

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

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

FIG. 6 is a sectional view of a pipe wall portion showing a fourth embodiment.

FIG. 7 is a sectional view of a pipe wall portion showing a fifth embodiment.

FIG. 8 is a sectional view of a pipe wall portion showing a sixth embodiment.

[Explanation of symbols] (1) Pipe wall (2) Mountain top (2a) Near mountain top (3) Inclined wall (4) Inclined wall (5) Valley bottom (5a) Near valley bottom (P) Support point (s) ) Center line

Claims (5)

[Claims] 1. A synthetic resin pipe in which the pipe wall (1) is formed in a spiral corrugated shape, and the pipe wall (1) has a substantially triangular cross section or a trapezoidal cross section, and the peak portion ( 2) or a portion (2a) near the peak (2) of one of the inclined walls (3) and (4) forming the pipe wall (1), and a valley bottom (5) or The part (5a) near the valley bottom part (5) of the one inclined wall (3) is formed of a partially flexible resin material, and the entire pipe wall (1) of the other part is made of a hard resin. The one sloped wall (3) is formed of a material, and the one inclined wall (3) with the flexible resin material part (2a) or its vicinity (2a) formed of the flexible resin material as a fulcrum (P). A pressure-resistant synthetic resin pipe having a structure capable of self-maintaining the approaching posture by moving in a direction approaching the other inclined wall (4) beyond the center line (s) passing through the fulcrum (P). 2. The method according to claim 1, wherein the length of the inclined wall (3) that moves beyond the center line (s) is shorter than the length of the other inclined wall (4). Pressure resistant synthetic resin tube. 3. The inclination angle (α) of the inclined wall (3) which moves beyond the center line (s) with respect to the center line (s) of the other inclined wall (4) with respect to the center line (s) ( The pressure resistant synthetic resin pipe according to claim 1, wherein the pressure resistant synthetic resin pipe is formed at an angle smaller than β). 4. The pressure-resistant synthetic resin pipe according to claim 1, wherein an inner layer (6) made of a soft resin is integrally formed on the inner peripheral surface side of the valley bottom portion (5). 5. The pressure-resistant synthetic resin pipe according to claim 1, wherein an outer layer (7) made of a soft resin is integrally formed on the outer peripheral surface side of the mountain top portion (2).