JP2002206670A - Pipe protective cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe protective cover 1 capable of preventing a pipe from being damaged by sliding contact with sediment when the pipe is advanced in the sediment. SOLUTION: The pipe protective cover 1 is woven cylindrically by a warp 2 and a weft 3, and woven into a continuous integral woven fabric without a seam on the whole. Thus, the strength of the pipe protective cover 1 can be made uniform and high in the axial direction 21 and in the peripheral direction 22. Since the adjacent warps come into contact with each other, the pipe protective cover 1 is determined in number of the warps and wefts 2, 3 and fineness so that no weave texture penetrating in the internal and external directions is formed and even if frictional resistance received from the sediment works, the pipe 4 is not exposed to the sediment. Accordingly, the pipe 4 can be prevented from being exposed to the sediment and damaged by sliding contact of the sediment and the pipe protective cover 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe protection cover for protecting a pipe buried by a non-cutting method.

[0002]

2. Description of the Related Art When a pipe is buried in earth and sand by a non-cutting method, the pipe is propelled through the earth and sand. At this time, in order to prevent the pipe from being damaged by sliding with earth and sand, a pipe protection cover is attached to the pipe. The tubular body protective cover is formed in a cylindrical shape by partially overlapping the widthwise end portions of a flexible elongated belt-shaped sheet body and sewing them together. By attaching such a tube body protective cover to the tube, the tube is prevented from sliding against earth and sand, and damage to the tube is prevented.

[0003]

Such a prior art tubular body protective cover is formed in a cylindrical shape by sewing both ends in the width direction of the sheet body, so that a joint portion extending in the axial direction at one location in the circumferential direction. Exists. The seam portion has a low strength due to its structure, and when the tube body is propelled through the earth and sand with the tube body protection cover attached thereto, the seam of the seam portion is released due to frictional resistance received from the earth and sand, and the seam portion is removed. The protective cover is torn. Therefore, damage to the tube cannot be prevented.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pipe protection cover which can prevent the pipe from being damaged by sliding contact with the sand when the pipe is propelled through the earth and sand.

[0005]

According to the present invention, a plurality of first pipes extending in a predetermined first direction are mounted on a pipe buried by a non-cutting method when the pipe is propelled through earth and sand. A plurality of second yarns extending in a second direction different from the first direction, wherein at least one of adjacent first yarns and adjacent second yarns is in contact with each other; A tubular body protection cover characterized in that it is woven in a tubular shape by each first yarn and each second yarn.

According to the present invention, the first yarn and the second yarn are woven in a tubular shape and have no seams throughout.
Woven in a continuous monolithic fabric. As a result, the strength of the tubular body protective cover can be increased uniformly and axially and circumferentially. In addition, since at least one of the adjacent first yarns and the adjacent second yarns are in contact with each other, the tube protection cover has no gap to be inserted inward and outward, and the tube is exposed to the outside. It can be covered by the pipe protection cover so as not to be in contact with the pipe, and it is possible to prevent earth and sand from coming into contact with the pipe.

Further, according to the present invention, when the number of the first yarn and the second yarn in the unit size area is attached to the pipe and the pipe is propelled through the earth and sand, the number of the first and second yarns is reduced with respect to the external force received from the earth and sand It is characterized in that it is determined to be the number of blocks that prevent the penetration of soil and sand components.

According to the present invention, the number of the first yarn and the second yarn in the unit size area can be determined by attaching the pipe protective cover,
When the pipe is propelled through the earth and sand, the number is determined to be such that penetration of the earth and sand components is prevented against external force received from the earth and sand. Thereby, when the pipe body with the pipe body protection cover is propelled through the earth and sand, it is possible to prevent the earth and sand from penetrating through the texture formed by the first yarn and the second yarn. Therefore, even if it receives external force from earth and sand, the pipe body protection cover can prevent earth and sand from directly contacting the pipe.

Further, the present invention is characterized in that each of the first yarns extends in the axial direction, each of the second yarns extends in the circumferential direction, and the number of the first yarns in the unit size area is larger than the number of the second yarns. And

According to the present invention, each first yarn extends in the axial direction, each second yarn extends in the circumferential direction, and the number of the first yarns in the unit size area is larger than the number of the second yarns. It is possible to reduce the weight of the tube body protection cover and to increase the strength in the axial direction with respect to the circumferential direction.

Further, the present invention is characterized in that the circumferential length is determined so that the pipe can be inserted gently.

According to the present invention, the circumference is determined so that the pipe can be loosely inserted, so that the pipe protection cover can be easily attached to the pipe.

[0013]

FIG. 1 is an enlarged perspective view showing a part of a tube protection cover 1 according to an embodiment of the present invention, and FIG. FIG. 3 is a perspective view showing the entire tube protection cover 1 as viewed from the front. The pipe protection cover 1 is a tubular cover that is fitted to the pipe 4 embedded by a non-cutting method so as to cover the pipe 4 from the outside, and protects the pipe 4. The tube 4 is a tube buried underground for transporting gas including city gas, for example, and is made of synthetic resin, for example, polyethylene. In the non-cutting method, the pipe 4 is buried by being propelled through the earth and sand. In this propulsion, the pipe 4 is protected by sliding contact with the earth and sand to prevent the pipe from being damaged. The cover 1 is attached to the tube 4.

The tube protection cover 1 has a plurality of first yarns, ie, warp yarns 2 and a plurality of second yarns, ie, weft yarns 3.
Extend in the axial direction 21 which is the first direction, and each weft 3
And extends in the circumferential direction 22, which is a second direction different from the direction of the above, and is woven into a cylindrical shape. The warp yarn 2 and the weft yarn 3 are each formed by twisting a plurality of fibers. As the fiber, a synthetic resin is used in order to reduce the outer diameter of the yarn and obtain a high strength, and it is preferable to use a polyester fiber in order to further increase the strength.

Each warp yarn 2 is zigzag wound while passing between the weft yarns so as to be wound around the adjacent weft yarns 3 from different directions. In other words, the warp yarns 2 are interlaced and extend in the axial direction 21. Conversely, each weft yarn 3 is wound zigzag while passing between the warp yarns so as to be wound around the adjacent warp yarns 2 from different directions. In other words, the weft yarns 3 are interlaced and extend in the circumferential direction 22. Accordingly, each weft 3 is sandwiched between adjacent warps 2, and each warp 2 is sandwiched between adjacent wefts 3. As described above, the tubular body protective cover 1 is organized in a so-called plain weave. In the plain weave design, the warp 2 is the weft 3
And the interval at which the weft yarn 3 intersects the warp yarn 2 is minimized, so that the warp yarn 2 and the weft yarn 3 are unlikely to be loosened, and the tubular protective cover 1 organized in a plain weave can obtain high strength. it can.

The adjacent warp yarns 2 are arranged without a gap in the circumferential direction 22 and are in contact with each other between the adjacent warp yarns. As a result, the tubular body protective cover 1
It is woven so that there is no gap inserted in the thickness direction and therefore in the radial direction.

The tubular body protective cover 1 is woven into a seamless and seamless tubular integral fabric throughout the entirety. At this time, the weft yarn 3 is placed in the circumferential direction 2 of the pipe protection cover.
2 and, in the present embodiment, comprises one circumferential portion of one thread extending spirally around the axis in the circumferential direction 22. Therefore, the tubular body protection cover 1 is woven by a plurality of warp yarns 2 extending in the axial direction 21 and one yarn extending spirally around the axis in the circumferential direction 22 so as to be aligned in the circumferential direction 22. It is woven in a tubular shape. Specifically, for example, each warp yarn 2 is arranged so that adjacent warp yarns extend in mutually different radially inner and outer directions, and one yarn consisting of each weft yarn 3 is placed between adjacent warp yarns. So that one warp makes one turn, the direction in which each warp yarn 2 extends is changed in the opposite direction, and one thread makes one turn as described above. By repeating, the tubular body can be woven with one thread including each warp yarn 2 and each weft yarn 3.

Further, since the tubular body protective cover 1 is woven without a seam, there is no seam such as a sewn portion.
The strength can be made uniform and large over the axial direction 21 and the circumferential direction 22. Tube protection cover 1
Is woven as described above, the warp yarns 2 and the weft yarns 3 are not completely fixed, can be slightly displaced from each other, and have higher flexibility than a molded sheet body. Can be.

FIG. 4 is a sectional view showing a non-cutting method. In the non-cutting method, when burying the pipe 4 in earth and sand, the pipe 4
Is a construction method in which the starting shaft 5 and the reaching shaft 6 are constructed without excavating the entire area where the shaft is buried, the pipe 4 is made to penetrate into the earth and sand from the starting shaft 5, and the tube 4 is propelled to the reaching shaft 6. . For example, there is a method in which the pipe 4 is buried as a new pipe while the existing pipe 7 is crushed. More specifically, a pipe 4 such as a deteriorated existing pipe 7 such as a cast iron pipe and a polyethylene pipe which is a new pipe is used. There is a way to replace it.

A starting shaft 5 and a reaching shaft 6 are constructed near both ends of the existing pipe 7, and then the pipe 4 is inserted into the existing pipe 7 from the starting shaft 5. At this time, the entire tube 4 is covered with the tube protection cover 1, and a tapered tip jig 9 is attached to one end in the axial direction, which is the end on the insertion side of the tube 4. The tip jig 9 is provided with a joint 10, and a rod 11 connected to the joint 10 extends through the existing pipe 7 to the reaching shaft 6. The reaching shaft 6 is provided with a retracting device 12, and the rod 11 is retracted toward the reaching shaft by a hydraulic motor or the like of the retracting device 12. As a result, the pipe body 4 connected to the rod 11 via the joint portion 10 is propelled in the propulsion direction 13 toward the reaching shaft 6. At this time, the tip jig 9 of the existing pipe 7 is
The pipe 4 is propelled through the earth and sand while being crushed. The crushed pieces 14 become a part of the earth and sand.

The pipe 4 propelled in the soil is entirely covered with the pipe protection cover 1 without any gap, so that the pipe 4 is prevented from coming into contact with the earth and sand including the crushed pieces 14, and the pipe 4 is damaged. Can be prevented.

FIG. 5 is a perspective view showing the distal end of the tubular body 4 to which the distal end jig 9 is attached. The tubular body 4 is provided with the tubular body protective cover 1 so as to cover the entirety, and a distal end jig 9 is coupled to a distal end portion. The tip jig 9 is formed in a substantially conical shape whose diameter decreases toward one end in the axial direction, and an insertion hole into which the pipe 4 is inserted with the pipe protection cover 1 attached to the other end in the axial direction. Are formed to be open in the axial direction. The tube 4 is inserted into the insertion hole so that the tip jig 9 and the tube 4 are coaxial.
Is inserted at one end in the axial direction. A joint 10 is provided at one end in the axial direction of the tip jig 9, and a rod 11 is coupled to the joint 10.

FIG. 6 is a sectional view showing the tube 4 to which the tube protection cover 1 is attached. FIG. 6A is a sectional view taken along line S in FIG.
FIG. 6 shows a cross section of the tubular body protection cover 1 as viewed from 1-S1, and FIG.
(2) shows a cross section of the tubular body protective cover 1 as viewed from the section line S2-S2 in FIG. As shown in FIG. 6A, the circumference of the inner peripheral surface of the tubular body protection cover 1 is formed to be larger than the circumferential length of the outer peripheral surface of the tubular body 4, and is determined to have a dimension that allows the tubular body 4 to be inserted slowly. Is done. That is, when the tubular body protective cover 1 is attached to the tubular body 4, the tubular protective cover 1 is sized so that the tubular protective cover 1 can be smoothly attached to the tubular body 4 without being caught on the tubular body 4. Is determined to have a large fold and not to relax.

Thus, the tube protection cover 1 can be easily attached to the tube 4. Further, when propelled in the earth and sand, since a large number of large folds are not formed, the area of sliding contact with the earth and sand is reduced, and external force received from the earth can be reduced.

As shown in FIG. 6 (2), when the tip jig 9 is attached to the pipe 4, the circumference of the pipe protection cover 1 is larger than the circumference of the pipe 4. When the outer circumferential surface of the pipe is brought into contact with the outer circumferential surface from one location in the circumferential direction, a fold 15 that does not directly contact the pipe 4 is generated. The fold 15 is bent along the circumferential direction 22 and adhered by an adhesive tape. Thereafter, the tip jig 9 is connected to the tube 4 so that the insertion hole and the end of the tube fit. At this time, the circumferential length of the tube body protective cover 1 is large as described above.
Since it is determined not to form the ridge 5, the pleat 15 is easily attached without making it difficult to connect the tube 4 to the tip jig 9.

As described above, when the circumferential length is short, the tubular body protective cover 1 cannot be easily attached to the tubular body 4, and when the circumferential length is long, the tubular body protective cover 1 slides when propelled through the earth and sand. The area increases and receives a large external force. In order to prevent the connection between the tip jig 9 and the tube 4 from becoming difficult, the tube 4 can be loosely mounted, and a large number of large folds 15 are not formed in the mounted state, and the folds 15 do not become long. A circumference that facilitates the connection between the tube 4 and the tip jig 9 is preferable.

Tables 1 and 2 show examples of specific dimensions of the tubular body protective cover 1. Table 1 shows the outer diameter of the gas pipe as each pipe 4 and the inner diameter of each pipe protection cover 1 used for each gas pipe, and Table 2 shows the peripheral length of the outer peripheral surface of the gas pipe as each pipe 4. The peripheral length of the inner peripheral surface of each tube protection cover 1 used for each gas tube is shown.

[0028]

[Table 1]

[0029]

[Table 2]

The inner diameter of the tube protection cover 1 is selected to be larger than the outer diameter of the tube 4 by 10 mm or more and 30 mm or less. , 4
It is selected from 0 mm or more and 70 mm or less. By selecting such dimensions, the above-described effects can be achieved. Further, as shown in Tables 1 and 2, the tube body protective cover 1 has an inner diameter that is 15 mm or more and 20 mm or less larger than the outer diameter of the tube 4, or a circumferential length of the inner peripheral surface of the tube 4. The above-mentioned effect can be more suitably achieved by selecting a range that is 45 mm or more and 65 mm or less with respect to the circumference of the outer peripheral surface.

FIG. 7 is a view for explaining a state of formation of the weave of the tubular body protective cover 1. FIG. 7A is a front view showing a part of the tubular body protective cover 1, and FIG. 2) is a front view showing a part of the cover 30 of the comparative example. When the pipe 4 is buried in the earth and sand as shown in FIG. 4, the pipe protection cover 1 slides against the earth and sand and receives an external force from the earth and sand. The external force includes a penetrating force that causes the tubular body protective cover 1 to penetrate a soil material such as sand and other small pieces as an object. When the number of each warp yarn 2 and each weft yarn 3 per unit size area is small and coarsely woven, due to external force received from earth and sand like the cover 30 of the comparative example,
As shown in FIG. 7 (2), the composition forms the texture 16 and penetrates. When the texture 16 is formed and the structure penetrates in this way, the pipe body 4 is directly in sliding contact with the component penetrated through the texture 16 and is damaged. On the other hand, in the tubular body protective cover 1 of the present embodiment, the number of the warp yarns 2 and the weft yarns 3 per unit size area is reduced with respect to the external force received from the earth and sand in consideration of the cross-sectional area of the warp yarns 2 and the weft yarns 3. The number of the warp yarns 2 is determined so that the warp yarns 2 are kept in contact with each other so that the texture 16 is formed and the components do not penetrate.

More specifically, the numbers and the cross-sectional areas of the warp yarns 2 and the weft yarns 3 per unit size area are determined based on the strength against the penetrating force. That is, the number and the cross-sectional area of the warp yarns 2 and the weft yarns 3 are determined so that the tubular body protective cover 1 can withstand a strength greater than the penetration force received from the earth and sand when propelled through the earth and sand. Here, the strength with respect to the penetrating force is a force required for an object including the above-mentioned earth and sand components to penetrate the pipe body protective cover 1, and in this embodiment, is measured using an apparatus 50 as shown in FIG. The number and the cross-sectional area are determined based on the strength against the penetrating force to be performed.

Specifically, by using two holding means 43, the dimension L of one edge of each holding area is 80 mm, the edges are parallel to each other, and the distance D between the edges is each other. Is fixed so as to be 50 mm. In this state, the tip of a piercing piece 41 made of a wire having a diameter of 2 mm, for example, a steel wire and having a hemispherical tip at the center of the area sandwiched between the holding areas, is attached to the tube protection cover. 1, and a pressing force (load) is applied to the piercing piece 41 by a pressing means 44 such as a push meter in a direction penetrating the tube protection cover 1, and the pressing force is measured by the pressing means 44. I do. The pressing force is gradually increased, and the maximum pressing force (load) measured immediately before the insertion piece 41 penetrates is determined as the strength with respect to the penetration force of the tubular body protective cover 1.

In addition to the measurement of the strength with respect to the penetrating force, the inventor of the present invention carried out a test of attaching the tube 4 to the tube 4 and propelling the tube 4 through the earth and sand. I checked whether it was done. This texture 1
The determination as to whether or not 6 was formed was made based on whether or not a notch with a depth dimension exceeding 20% (１ ／) of the thickness of the tube 4 was formed in the tube 4. When a notch with a depth dimension exceeding 20% of the thickness is formed in the tube 4, the tube 4
May cause gas leakage or the like before the predetermined service life is used. In the case of a notch scratch having a thickness of 20% or less of the thickness of the tubular body 4, gas leakage does not occur even when the service life is predetermined. Has been confirmed by Therefore, this was used as the above judgment material. That is, the weave 16 is a gap in the thickness direction formed in the tube body protection cover 1 when a notch flaw having a depth dimension exceeding 20% of the thickness of the tube body 4 is formed in the tube body. At this time, the load with which the test jig 41 presses the tube protection cover 1 is measured by a push meter,
The maximum load can be obtained as the strength for the penetration force. Table 3 shows the strength of the tube protection cover 1 with respect to the penetrating force.

[0035]

[Table 3]

As is apparent from Table 3, even if a penetration force of less than 17.64 N acts, the tube body protective cover 1 has a strength against a penetration force in which the insertion piece 41 does not penetrate in the thickness direction. Conversely, the tube body protective cover 1 has a strength against a penetration force of 17.64 N or more.

In Table 3, the upper limit value of the strength with respect to the penetrating force is shown at 25.4 N, which is the value shown for the tube protection cover 1 tested by the inventor.
There is no upper limit value of the strength of, and it may exceed the upper limit value of 25.4N. If the strength is 17.64 N or more, the texture 16 is not formed as described above, and it is possible to prevent a component made of earth and sand from penetrating and contacting the pipe 4. Table 3
As shown in the figure, it was confirmed that the texture 16 was formed in the cover 30 of the comparative example having a strength of less than 17.64 N, and it was confirmed that a strength of 17.64 N or more was required. Therefore, the tubular body protective cover 1 is formed with a strength against a penetration force of 17.64 N or more.

The strength against this penetrating force is greater than the penetrating force that causes the components of the earth and sand to penetrate the tube body protective cover 1 by the external force received from the earth and sand when the tube 4 is propelled. Therefore, since the penetration force received from the earth and sand is smaller than the strength of the tube protection cover 1 with respect to the penetration force, the formation of the texture 16 in the tube protection cover 1 propelled in the earth and sand is prevented.

More specifically, the dimension of the tube body protective cover 1 in the axial direction 21 and the circumferential direction 22 is 2.54 cm ×
Using the density X of the warp yarn 2 and the density Y of the weft yarn 3, the volume G per area of 2.54 cm (1 inch × 1 inch) is selected so as to fall within the range shown by the formulas (1) to (4). Is done.

[0040]

(Equation 1)

Here, the volume lower limit value G ₁ is a value at which the weave 16 is not formed even when the pipe body protective cover 1 receives an external force during the accumulation of earth and sand. This is the value at which the strength is provided. Volume upper limit G
Numeral ₂ is a value at which the flexibility of the tube body protective cover 1, that is, the ease of bending is not significantly reduced. The volume G is A, the number of the warp yarns 2 in the region, B is the number of the weft yarns 3 in the region, C is the fineness of the warp yarn 2, D is the fineness of the weft yarn 3, X is the density of the warp yarn 2, and X is the density of the weft yarn 3. The density is represented by Expression (2), where Y is Y. In the formula (2), the units of the finenesses C and D of the warp yarn 2 and the weft yarn 3 are g / km (= tex), the units of the densities X and Y are g / cm ³ , and the units of the volume G are cm ³
It is. The volume lower limit G ₁ is 0.283444927.
It is represented by 5 cm ³ , and the volume upper limit G ₂ is 0.566898
Provided at 55 cm ³ .

When the volume G per area of the tubular protective cover 1 is less than the lower volume limit G ₁ , the tubular protective cover 1
As described above, when propelled in earth and sand as described above, the texture 16 may be formed by an external force received from the earth and sand. In the case where the volume G of the tube protective cover 1 exceeds the volume limit G _2, too thick tube protective cover 1 decreases flexibility, less likely to deform. This makes handling difficult, such as difficulty in mounting on the tube. Thus, tube protective cover 1 by volume G per the area to select a volume lower limit value G ₁ or more and volume upper limit value G ₂ following range, texture 16 is not formed at promoting in soil, the tube It can be easily attached to the body 4. About such an effect, the effect is confirmed by the experiment of the inventor.

More specifically, when the warp yarn 2 and the weft yarn 3 are formed, the volume G becomes G ₁ = 0.283449.
By selecting the cross-sectional area or the number of the warp yarns 2 and the weft yarns 3 so as to be 275 cm ³ or more, the contact state can be maintained as shown in FIG. . Further, by selecting the warp yarns 2 and the weft yarns 3 so that the volume G per area becomes G ₂ = 0.5668985 cm ³ or less, the thickness of the tubular body protective cover 1 can be reduced to 2 mm or less. When the thickness of the tube protection cover 1 exceeds 2 mm, the mountability to the tube 4 and the ease of fixing to the tip jig 9 are reduced, and the tube protection cover 1 cannot be mounted properly. .

The volume G per area is G ₁ = 0.28
If it is less than 3449275 cm ³ , the pipe body protective cover 1 propelled in the earth and sand has a texture 16 inserted in the thickness direction due to the frictional resistance received from the earth and sand, and the pipe body 4 and the earth and sand are in sliding contact with each other. The body surface is damaged. The volume G per area is G ₂ = 0.56688985.
In the case of 5 cm ³ or more, the thickness of the tube protection cover 1 increases, so that the flexibility decreases and it becomes difficult to insert the tube into the tube 4. By further increasing the thickness,
The connection between the tip jig 9 and the tube 4 becomes difficult. In addition, problems such as increased mass, excessive quality and increased production cost arise.

Therefore, the tubular body protective cover 1 has a volume G per area of G ₁ ≦ G ≦ G _2, that is, 0.2834.
By selecting the range of 49275 cm ³ or more and 0.56688955 cm ³ or less, the texture 16 is not formed even when propelled in the earth and sand, so that the light-weight pipe protective cover 1 having good mountability to the pipe 4 and being lightweight can be obtained. be able to. 2.5 that satisfies the preferable volume range G of such a tubular body protective cover 1.
The mass H per 4 cm × 2.54 cm area falls within the range represented by the formulas (5) to (8) when, for example, a polyester fiber having a density of 1.38 g / cm ³ is used.

[0046]

(Equation 2)

As described above, when the tubular body protective cover 1 is made of polyester fiber, the mass H per area is set to 0.1.
By selecting between 39116 g and 0.782232 g, the texture 16 is not formed during propulsion in the earth and sand, and the pipe can be easily mounted on the pipe.

Table 4 shows the warp yarn 2 per 2.54 cm × 2.54 cm of the tubular body protective cover 1 using polyester fiber.
Examples of specifications including the number of wefts 3 and the number of wefts 3 are shown.

[0049]

[Table 4]

As shown in Table 4, the tube protection cover 1 is
Each fineness C and D is 220 g / km (= tex = 2000
(Denier) warp yarn 2 and weft yarn 3 and the dimension of the tube body protective cover 1 in the axial direction 21 and the circumferential direction 22 is 2.54.
The number A of the warp yarns 2 is 5 per cm × 2.54 cm area.
6.4 yarns are woven so that the number B of the weft yarns 3 becomes 15.5 yarns. As a result, the volume G per area of the tubular body protective cover 1 is 0.2911142898 cm ^3.
Next, become less volume lower limit value G ₁ or more and volume upper limit G ₂ described above can be mounted of the pipe 4 to obtain a lightweight tube protective cover 1 is good. In addition, such a tubular body protective cover 1 has a width (half of the circumference) of 284 mm, a mass per 1 m of 390.9 g, and a tensile strength per 3 cm of the width.
It is 7056N in the axial direction 21 and 2113N in the circumferential direction 22, the elongation is 24.4% in the axial direction 21 and 11.6% in the circumferential direction 22, and the tear strength is 109 in the axial direction 21.
7N and 904N in the circumferential direction 22 of the weft. The measurement of the tensile strength and the elongation was performed based on the labeled strip method shown in Method A of Japanese Industrial Standard L1096 General Fabric Test Method, and the measurement of the tear strength was performed according to A-Law of Japanese Industrial Standard L1096 General Fabric Test Method. It is performed based on two methods (single tongue method).

Further, the number of the warp yarns 2 in the unit size area is selected to be larger than the number of the weft yarns 3. Thereby, the pipe protection cover 1 propelled in the axial direction 21 together with the pipe 4.
Can improve the strength in the axial direction 21 without increasing the mass, prevent the sliding contact with the earth and sand, and prevent the axial direction 21 from being damaged, and also prevent the axial direction 21 from breaking. . Specifically, the strength of the tube body protective cover 1 is increased by 7056 in the axial direction 21 per 3 cm width.
N, and 2113N in the circumferential direction 22, the axial direction 2
1 and the tubular body protective cover 1 can be prevented from breaking even when a tensile force acts in the circumferential direction 22.

In the non-cutting method, by attaching such a pipe protective cover 1 to a polyethylene pipe, it is possible to satisfactorily prevent damage to the peripheral surface of the soft polyethylene pipe and bury it. Specifically, by the non-cutting method,
When the polyethylene pipe is propelled in the earth and sand, even if external force received from the earth and sand acts on the pipe body protective cover 1, sliding contact between the polyethylene pipe and the earth and sand including the crushed pieces 14 of the existing pipe is prevented, and the polyethylene pipe is prevented from sliding. Notches of not less than 20% of the thickness are not formed on the surface of the polyethylene pipe. 2 of thickness
With less than 0% flaws, even if formed, no gas leakage will occur over a given service life. Therefore, the existing pipe can be favorably replaced with a polyethylene pipe.

The above embodiment is merely an example of the present invention, and the configuration can be changed within the scope of the present invention. For example, the warp yarn 2 and the weft yarn 3 may be other than polyester fiber, and other synthetic resins such as vinylon (density 1.26 to 1.3) may be used depending on the type of the tube 4 and the earth and sand.
0g / cm ^3), it may be formed by a nylon (density 1.14g / cm ^3). Further, even when the warp yarn 2 and the weft yarn 3 are woven by different textile materials, each yarn can be determined within the range of the above-described formulas (1) to (4). Further, although the tubular body protective cover 1 is structured by plain weaving the warp yarns 2 and the weft yarns 3, the tubular body protective cover may be structured by other structures such as twill weave, satin weave and combinations thereof. Further, a third yarn extending in a direction different from the direction in which the warp yarn 2 and the weft yarn 3 extend may be used.

[0054]

According to the first aspect of the present invention, the pipe buried by the non-cutting method is provided with the pipe protection cover of the present invention so that when the pipe is propelled through the earth and sand, the entire circumference thereof is improved. The surface is completely covered by the pipe body protective cover, and is prevented from coming into contact with earth and sand. In addition, the tubular body protective cover integrally formed in a tubular shape can be configured to have a uniform and high strength as a whole, thereby preventing damage to the tubular body protective cover and maintaining the protection effect. Therefore, it is possible to prevent the pipe body from being damaged by sliding contact with earth and sand.

According to the second aspect of the present invention, the tubular body protective cover can prevent the formation of the texture even when subjected to external force from earth and sand. In addition, the sliding contact between the soil and the pipe is reliably prevented without directly contacting the soil. Therefore, the tube
Damage due to sliding contact with earth and sand can be more reliably prevented.

According to the third aspect of the present invention, since the strength in the axial direction can be increased, it is mounted on the pipe propelled in the axial direction, and the pipe is more reliably prevented from being damaged. be able to.

According to the present invention, the tube protection cover can be easily attached to the tube. This prevents the tubular body protective cover from being caught on the tubular body at the time of mounting, and can reliably cover the tubular body in the mounted state.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a part of a tube protection cover 1 of the present invention;

FIG. 2 is a front view showing the tube body protective cover 1. FIG.

FIG. 3 is a perspective view showing the entire tube body protection cover 1;

FIG. 4 is a schematic view showing a non-cutting method.

FIG. 5 is a perspective view showing a distal end portion of the tubular body 4 to which the distal end jig 9 is attached.

FIG. 6 is a cross-sectional view showing the tube 4 to which the tube protection cover 1 is attached.

FIG. 7 is a front view showing the tube protection cover 1 and a cover 30 of a comparative example.

FIG. 8 is a perspective view showing an apparatus 50 for measuring a strength with respect to a penetrating force.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pipe protection cover 2 warp 3 weft 4 pipe 5 starting shaft 6 reaching shaft 8 tip 9 tip jig 13 propulsion direction 14 crushed piece 16 texture 21 axial direction 22 circumferential direction

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Katsumi Ikeside 4-5-1, Nobori, Nishi-ku, Osaka-shi, Osaka F-term in Yotsugi Corporation (Reference) 2D054 AA06 AC18 AD29 FA11

Claims (4)

[Claims] 1. A pipe buried by a non-drilling method,
A plurality of first yarns, which are mounted when the tube is propelled through earth and sand and extend in a predetermined first direction, and a plurality of second yarns extending in a second direction different from the first direction, are provided. The first yarns and the second yarns are woven in a cylindrical shape in a state where at least one of the adjacent first yarns and the adjacent second yarns are in contact with each other. Tube protection cover. 2. The number of the first yarn and the second yarn in the unit size area is determined by the structure of the earth and sand against an external force received from the earth and sand when the tube is mounted on the tube and the tube is propelled through the earth and sand. 2. The tubular body protective cover according to claim 1, wherein the number is determined so that penetration of an object is prevented. 3. The method according to claim 1, wherein each of the first yarns extends in the axial direction, each of the second yarns extends in the circumferential direction, and the number of the first yarns in the unit size area is larger than the number of the second yarns. Item 3. The tubular body protective cover according to Item 1 or 2. 4. The tubular body protective cover according to claim 1, wherein the circumferential length is determined to a dimension that allows the tubular body to be loosely inserted.