JPH0520945Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a method for detecting underground objects that indicate the presence and type of underground objects such as gas pipes, water pipes, electric power, and communication cables during surface excavation work. The present invention relates to a display device.

Conventional technology Because underground objects such as gas pipes, water and sewage pipes, electric power, and communication cables are not visible from the ground surface, they can be damaged during surface excavation for construction work, and there are cases where this has led to major accidents. There are also quite a few.

Conventionally, a method has been used in which a strip-shaped sheet of vinyl or the like is buried near the ground surface above a buried object. If it is just a sheet, it will be easily cut by a shovel of an excavating machine. Therefore, we improved this by folding the sheet in the longitudinal direction and fixing it by spot welding. The weakened parts in the width direction are placed alternately at intervals (Jikko Sho 51-5212), or the belt-shaped sheet is folded in a zigzag pattern and fastened with sewing thread (Jikko Sho 51-5212).
55-7277), sheets have been developed that are designed to stretch when pulled, causing the spot welds, weakened areas, and sewing threads to break.

Problems to be Solved by the Invention In order for the band-shaped sheet to be fully effective, it is necessary for the band-shaped sheet to be hooked up to the shovel of an excavation machine and sufficiently extended from the ground surface to be exposed above the ground. For this reason, the functions required of the belt-shaped sheet are such that the ratio of the length when stretched to the length when buried (hereinafter referred to as the stretch ratio) is sufficiently large, and the sheet is not likely to be torn when stretched. It has no structure. If providing such performance would increase the cost, it would be more advantageous to take measures such as making the buried object more durable. Therefore, buried object display devices must be low cost.

The above band-shaped sheet is folded in the longitudinal direction.
When the sheet is buried and excavation work is performed in the longitudinal direction, the shovel hits the sheet from the longitudinal direction. At this time, the tip of the shovel only presses the sheet downward and causes damage, but does not catch the sheet and lift it up. Usually, buried objects are laid along the length of the road, and excavation work is also carried out in this direction, so such sheets often do not provide sufficient effects.

In addition, a band-shaped sheet in which weakened parts in the width direction reaching one edge from the inside of the sheet and weakened parts in the width direction reaching the other edge are provided alternately at intervals has the following drawbacks. .

If the sheet breaks immediately when it is hoisted onto a shovel and stretched to its fullest extent, the construction worker will not be aware of the sheet's existence and the sheet will not be fully effective. In the above sheet, when it is stretched and stretched,
Stress is concentrated at the inner edge of each weakened portion of the sheet, and the sheet often breaks from there. In order to prevent such cutting, a material with high tear strength is required, which increases the cost of the material for the belt-shaped sheet.

When a band-shaped sheet is folded back in a zigzag pattern and secured with sewing thread, a hole is created in the sheet for the sewing thread to pass through, so the sheet may be torn from that part.

In addition, the method of folding a belt-shaped sheet is difficult to form an overlapping part during the production process, and the winding cannot be done smoothly, resulting in a complicated and large manufacturing machine, which increases costs. It has the disadvantage of getting old. In addition, the sheet is bulky, making it inconvenient to transport and work with.

The present invention solves the problems associated with the above-mentioned conventional technology by using a cylindrical sheet and providing a spiral weakened part, and has a high elongation rate and tear strength.
The purpose of the present invention is to provide a display device for underground objects that can be manufactured at low cost using a simple manufacturing machine.

Means for Solving the Problems The present invention provides a flexible cylindrical sheet 1 made of a water-resistant and corrosion-resistant synthetic resin material, which is perforated in a spiral shape at a constant angle θ with respect to the longitudinal direction. Eye 2
The perforations 2 are formed by elongated holes 50 that extend in the arrangement direction 52 of the perforations 2 at intervals 51, and the length of the elongated holes 50 along the arrangement direction 52 is L1 is a length exceeding the length L2 of the interval 51 along the arrangement direction 52, and the pitch L3 of the perforation 2 along the longitudinal direction of the sheet 1 is sufficiently longer than the length L2 of the interval 51. This is a display device for underground buried objects, which is characterized by printing information such as warning signs, company names, and types of buried objects using ink that does not easily change color.

Effect According to the present invention, the sheet 1 is made of flexible synthetic resin and has a cylindrical shape, and the sheet 1 has the following features:
The perforations 2 are formed in a spiral shape, so that when the present display device is hooked to the tip of a shovel, for example, the intervals 51 between the perforations 2 are divided and elongated. The perforations 2 are formed by elongated long holes 50 at intervals 51 in the arrangement direction 52 of the perforations 2, and the length L1 of the long holes 50 in the arrangement direction 52 is defined by the arrangement of the intervals 51. Since it is less than the length L2 along the direction 52, it is extremely easy to divide the interval 51 at the perforation 2 with a shovel or the like.

Moreover, since the pitch L3 of the perforation 2 along the longitudinal direction of the sheet 1 is selected to be sufficiently long compared to the length L2 of the interval 51, when the sheet 1 is hooked to the tip of the shovel and pulled, the sheet 1 There is no risk of it being torn.

Embodiment FIG. 1 is a diagram showing a display device 5 which is an embodiment according to the present invention. This underground buried object display device 5 is foldable and therefore flexible, and is manufactured using a cylindrical sheet 1 having a width L when folded, made of nylon or polyester. The material is made of synthetic resins such as vinylon, polypropylene, and polyethylene, which are water and corrosion resistant and have appropriate tensile and tear strength.

The display device 5 is a cylindrical sheet 1 in which perforations, which are weakened portions 2, are formed at a constant angle θ with respect to the longitudinal direction. This weakened portion 2 becomes a spiral as shown in FIG. 2 when the display device 5 is not folded and is in a cylindrical state.

The perforation 2 is in the arrangement direction 52 of the perforation 2.
It is formed by elongated holes 50 extending in the arrangement direction 52 at intervals 51 . The length L1 of the elongated holes 50 along the arrangement direction 52 is longer than the length L2 of the interval 51 along the arrangement direction 52.
The pitch L3 of the perforation 2 along the longitudinal direction of the sheet 1 (left-right direction in FIG. 1) is selected to be sufficiently longer than the length L2 of the interval 51.

On this display device 5, a caution display, company name, contact telephone number, type of underground object, etc. are printed with ink that does not easily change color.

The display device 5 is subjected to a moderate tensile load,
The weakened area cracks and stretches as shown in FIG. The expansion rate at this time is determined by the angle θ as expressed by the following equation.

Stretching rate=secθ Therefore, by changing the angle θ, it is possible to selectively set the stretching rate, and a sufficient stretching rate can be obtained.

Furthermore, the shape of the display device 5 when expanded is a sheet having a constant width, and the structure has a high tensile strength without stress concentration. For this reason,
Even if an inexpensive material with relatively low tensile strength is used, sufficient tensile strength can be obtained.

FIG. 3 is a sectional view showing the embedding process of the display device 5. When burying the buried object 3 to a desired depth, the ground is excavated from the ground surface to that depth, as shown in FIG. 31. As shown in FIG. 3, the buried object 3 is installed at a predetermined position, and then covered with earth and sand. At this time, the depth from the top of the buried object 3 to the surface of the earth and sand is generally set to, for example, 30 cm to 60 cm.
A display device 5 for an underground object 3 according to the present invention is placed on the surface of the earth and sand as shown in FIG. 3. Finally, fill the earth and sand until it is at the same height as the ground surface, and
As shown in FIG. 4, the burial is completed.

FIG. 4 is a diagram for explaining the implementation state of the display device 5. In construction work such as excavation work, the tip of the power shovel 4 first hooks and lifts the display device 5 of the present invention before reaching the underground object 3. The display device 5, as shown in FIG.
With constant tensile loading, the weakened area cracks and stretches at a sufficient elongation rate. Furthermore, when stretched, the structure does not have any stress concentration or other factors that can easily cause breakage. Therefore, as shown in Figure 4, it can be lifted to the ground without being cut.

The display device 5 hooked to the tip of the power shovel 5 allows the construction worker to know the existence of the buried object 3, thereby preventing accidents due to damage to the buried object 3.

One of the major features of the present invention is that it is easily manufactured. An example of the manufacturing method will be explained below.

FIG. 6 is a front view showing the configuration of the manufacturing machine 30 for the display device 5. As shown in FIG. The manufacturing machine 30 includes a weakened portion forming machine 21 that forms weakened portions 2 such as perforations on the cylindrical sheet 1 .

Resin, which is the raw material for the display device 5, is made into pellets or powder and stored in the hopper 11.
The extruder 12 includes a heater and a screw (not shown), and heats, melts, and melts pellet or powder raw materials supplied from the hopper 11.
Knead and generate the necessary pressure. The rotary unit 13 is a rotating mechanism for dispersing unevenness in the thickness of the cylindrical sheet 1.

The melted raw material resin is formed into a cylindrical shape by a device called a die 15, air-cooled by an air ring 16, and sent to a weakened portion forming machine 21. The cylindrical sheet 1 on which the weakened portion 2 is formed is a stabilizer plate 17
folded by the two rollers 18a, 18
The roller 37 is sent to the winding machine 19 via the pinch roller 18 made up of rollers 36a and 36b and the pinch roller 36 made up of two rollers 36a and 36b.
a or rolled up by roller 37b. Pinch rollers 18 and 36 are rotationally driven by motors 38 and 39, respectively.

Each part of the manufacturing machine 30 is provided with thermocouples and the like to measure temperature, and the temperature control panel 14 displays and controls these temperatures. Further, the operating state of the manufacturing section 30 is controlled by operating the operation panel 20.

Figure 7 shows the die 15 and air ring 1 of the manufacturing machine 30.
6 is a sectional view showing the structure of the weakened part forming machine 21, and FIG. 8 is a perspective view of the die 15, the air ring 16, and the weakened part forming machine 21. The molten raw material is supplied from below the die mandrel 23, which is a component of the die 15, in FIG. 7, and is sent upward along a spiral groove formed on the side surface of the die mandrel 23. At the outlet of the die 15, a parallel portion 40 is provided between the die mandrel 23 and the die body 24 with a constant gap, thereby adjusting the uneven thickness of the cylindrical sheet 1.

The resin extruded from the die 15 into a cylindrical shape is cooled by being blown with air in an air ring 16. The air ring 16 has a circumferential direction, for example, 2
A hose port 31 is provided at a location, and this hose port 3
Air is fed into the tank 1 via a hose or the like (not shown). The air sent in is uniformly dispersed over the entire circumference in the air ring 16, and is blown into the cylindrical resin from two air outlets 32 and 33 formed along the circumference.

The cylindrical sheet 1 thus obtained is sent to a weakened portion forming machine 21, and weakened portions 2, which are perforations, are formed. The weakened portion forming machine 21 includes, for example, a rotating section 27, a motor 25 that rotates the rotating section 27 at a predetermined rotational speed, a pressing member 29 that has a cylindrical shape and presses the cylindrical sheet 1, and a plurality of blades extending outward in the circumferential direction. , and a disk 26 rotatably supported by a rotating part 27 around a central axis.

The rotating part 27 is rotatably supported around the axis with respect to the fixed part 35 by a roller 35 attached to a fixed part 28 fixed to the air ring 16 and a roller 34 attached to the rotating part 27. . Since the rotating part 27 is rotated by the motor 25 at a constant rotation speed and the cylindrical sheet 1 is pushed upward in FIG. Contact as if drawing.

The blade formed on the disk 26 penetrates the cylindrical sheet and comes into contact with the pressing member 29. Therefore, the pressing member 29 is made of a material that does not cause the blade to become loose.

Since the disc 26 is rotatably supported by the rotating part 27, the blades formed on the disc 26 are attached to the cylindrical sheet 1.
, the linear velocity is 0, and one blade forms one cut of the perforation.

In this way, perforations can be easily formed in the cylindrical sheet 1 by simply adding the weakened portion forming machine 21 to the cylindrical sheet manufacturing machine.

In the sheet weakening portion forming machine 21, perforations are formed by a disk 26 having a plurality of blades formed on the outer periphery, but instead of the disk 26, a perforation member heated by a nichrome wire or the like is used. Perforations can also be formed by driving a needle-like perforation member with an air cylinder, a plunger, or the like.

Further, if a printing machine is provided between the pinch roller 36 and the winding machine 19 to print warning signs, company names, types of buried objects, etc., and the entire manufacturing process of the display device 5 is in-line, the efficiency will be further improved. manufacturing.

9 and 10 show the display device 5 of the present invention.
Other weakened part forming machine 2 used in the production of
FIG. 1a is a perspective view and a sectional view of FIG. The weakened part forming machine 21a is the weakened part forming machine 21 in FIG.
Instead, it is provided near the upstream side of the pinch roller 36 in the conveying direction of the cylindrical sheet 1, and includes a cylindrical body 41, a rail 45, a moving body 47, and a needle 46.

The cylindrical body 41 is formed by molding a light metal such as aluminum into a cylindrical shape, and has a concave groove 42 extending in the circumferential direction on the outer peripheral surface at the center of the side surface. Furthermore, surfaces 43 and 44 are formed on the upper and lower ends of the side surface of the cylinder 41 so that the cylindrical sheet 1 can move smoothly.

The rail 45 is provided outside the groove 42 of the cylinder 41 along the circumferential direction. The moving body 47 moves on this rail 45 at a constant rotational speed. The moving body 47 is equipped with a driving device such as an air cylinder or a plunger that drives the needle 46 in a direction toward/away from the cylinder 41. As a result, the needle 46 penetrates the cylindrical sheet and reaches the vicinity of the groove 42. In this manner, perforations can be formed in the cylindrical sheet 1 as the movable body 47 moves.

In the weakened portion forming machine 21a, perforations were formed by forming perforations in the cylindrical sheet 1 with a sharp needle 46; It is also possible to melt the shaped sheet 1 and provide perforations, thereby forming perforations. Further, as explained in connection with the weakened portion forming machine 21, a disk having a plurality of teeth formed on the outer periphery can also be used.

In such a weakened portion forming machine 21, although the lower surface of the cylinder 41 lightly contacts the outer peripheral surface of the pinch roller 36, the curved surface 44 allows the cylindrical sheet 1 to move smoothly. Also, by adjusting the rotational speeds W1 and W2 of the rollers 36a and 36b of the pinch roller 36, respectively,
Desired perforations can be formed in the cylindrical sheet 1 without the cylindrical body 41 tilting.

In the manufacturing method described above, a case has been described in which perforations are formed during manufacturing of a cylindrical sheet and the display device 5 is manufactured. The display device 5 can also be manufactured using the same method. That is,
In this case, as a molded product, a cylindrical sheet is wound up into a roll and a weakened portion, which is a perforation, is formed by secondary processing.

As an example of such a manufacturing method, a rolled cylindrical sheet 1 is placed on a mounting table installed above,
A pinch roller and a weakened portion forming mechanism are provided below. In this way, the upper rolled cylindrical sheet 1 is pulled downward by a pinch roller, and a weakened portion forming machine 21a as shown in FIG. It is possible to form perforations.

In this way, the display device 5 can be manufactured using simple manufacturing equipment.

Effects of the Invention As explained above, the display device for underground objects according to the present invention has sufficient elongation rate and structural tensile strength, and is unlikely to be cut due to tension. Therefore, during excavation work, it is exposed without being cut to the ground surface, and it is possible to reliably warn construction workers involved in excavation work of the existence of underground objects.

Furthermore, since it is manufactured using inexpensive materials and a simple manufacturing machine, it is possible to provide an inexpensive display device for underground objects.

In particular, according to the present invention, the sheet 1 is made of a flexible synthetic resin material and is cylindrical,
Since this cylindrical sheet 1 is provided with perforations 2, which are weakened portions, in a spiral shape, it is extremely easy to manufacture, and has the advantage of not requiring work such as welding, and has excellent productivity. This is particularly important when manufacturing the display device over long distances.

The perforations 2 are formed by elongated holes 50 that extend along the arrangement direction 52, and a gap 51 is formed between the elongated holes 50.
The length L1 along the arrangement direction 52 of the interval 51 is longer than the length L2 along the arrangement direction 52 of the interval 51,
Therefore, when the display device is hooked with a shovel or the like, the gap 51 is easily divided, and the display device is stretched into a long and thin strip.

Moreover, according to the present invention, the pitch L3 of the perforation 2 along the longitudinal direction of the sheet 1 is selected to be sufficiently long compared to the length L2 of the interval 51, so that the present display device in the stretched state The material will not be torn and torn, and can be reliably pulled up with a shovel or the like.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a display device 5 which is an embodiment of the present invention, FIG. 2 is a perspective view of the display device 5 in a cylindrical shape, and FIG. 3 is a cross-sectional view showing the embedding process of the display device 5. , FIG. 4 is a diagram for explaining the operating state of the display device 5, FIG. 5 is a diagram showing the expanded state of the display device 5, and FIG. 6 is a front view showing the configuration of the manufacturing machine 30 for the display device 5. , Figures 7 and 8 are manufacturing machine 3.
9 is a cross-sectional view and a perspective view showing the configuration of the die 15, air ring 16, and weakened portion forming machine 21 of No. 0.
The figure and FIG. 10 are a perspective view and a sectional view showing the structure of the weakened portion forming machine 21a. 1... Cylindrical sheet, 2... Weakened portion, 5... Display device.

Claims (1)

[Claims for Utility Model Registration] A flexible cylindrical sheet 1 made of water-resistant and corrosion-resistant synthetic resin is provided with perforations 2 in a spiral shape at a constant angle θ with respect to the longitudinal direction. The perforations 2 are formed by elongated holes 50 that extend in the arrangement direction 52 at intervals 51 in the arrangement direction 52 of the perforations 2, and have a length L1 along the arrangement direction 52 of the elongated holes 50. is a length exceeding the length L2 of the interval 51 along the arrangement direction 52, and the pitch L3 of the perforation 2 along the longitudinal direction of the sheet 1 is selected to be sufficiently long compared to the length L2 of the interval 51. , A display device for underground buried objects characterized by printing warning signs, company names, types of buried objects, etc. with ink that does not easily change color.