Tool for opening buried pipe windows

Abstract

To provide a window opening tool for an underground pipe which opens a window in the side face of an underground pipe without damaging a cable.SOLUTION: A window opening tool 1 for an underground pipe has a cylindrical part 2 at one end, and a peeling part 6 at the other end. A cylindrical gripping part 4 for gripping during work is formed between the cylindrical part 2 and the peeling part 6. A step part 8 is so formed as to be somewhat smaller than an opening diameter at a position at a predetermined depth on the back side from the opening end of the cylindrical part 2. This step part 8 is provided to prevent a core part 100c formed inside a cut groove 100b from penetrating more than necessary when the tip of the cylindrical part 2 is inserted into the annular groove formed in the underground pipe by means of a hole saw. The peeling part 6 has a semicircular plate part 6a for pulling up the core part 100c after generating cracks on the cut groove 100b. A slit 6b which can house the core part 100c is formed between the semicircular plate part 6a and the gripping part 4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a buried pipe window opening tool for opening a window for internal confirmation on the side of a buried pipe for accommodating a cable.

Background Art

[0002] Due to good landscape and high disaster resistance, the underground installation of cables has been progressing. In underground power distribution facilities, cables are laid in pipes such as metal pipes and vinyl pipes. At the stage of constructing the pipeline, regardless of the presence or absence of power supply, the pipes are laid in advance including the range where supply is expected, and later, additional cables are installed as needed.

[0003] Therefore, when new wiring becomes necessary, it is necessary to open a window on the side of the buried pipe to check the internal situation of the pipe.

[0004] FIG. 7 is a view showing a pipe drilling jig 200 for checking the inside of a conventional pipe. The pipe drilling jig 200 includes a pair of slide angles 202 for sandwiching and fixing the pipe 204 from the opposite pole directions. These slide angles 202 are provided slidably with respect to the angle receiver 201. The interval between the slide angles 202 is adjusted according to the size of the target pipe 204, and a hole is opened in the pipe 204 by the piercing member 203 in the fixed state.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if a jig like the one shown in Figure 7 is used to check the condition inside a buried pipe, there is no problem if no cable is installed, but if a cable is installed in the pipe, there is a risk of damaging the cable.

[0007] Therefore, the present invention aims to provide a buried pipe window-opening tool that can open a window in the side of a buried pipe without damaging the cable. [Means for solving the problem]

[0008] To achieve the above objective, the buried pipe window opening tool of the present invention is a buried pipe window opening tool for opening a window in the side surface of a buried pipe, and is characterized by comprising a cylindrical portion that can be fitted into a cutting groove formed by cutting an annular shape to an intermediate depth in the pipe thickness of the side surface, and a gripping portion extending to the side opposite to the side into which the cylindrical portion is fitted.

[0009] Furthermore, the buried pipe window opening tool of the present invention is characterized in that, in addition to the above configuration, it has an entry-preventing structure located further inside than the opening end of the cylindrical portion that prevents the core portion inside the cutting groove from entering.

[0010] Furthermore, in addition to the above configuration, the buried pipe window opening tool of the present invention is characterized in that the cross-sectional shape obtained by cutting the cylindrical portion radially is formed by a circular inner wall and an outer wall with a notch formed in a part of it.

[0011] Furthermore, in addition to the above configuration, the buried pipe window opening tool of the present invention is characterized in that the inner wall has a slip-prevention structure for the core portion in at least one of two opposing regions. [Effects of the Invention]

[0012] As described above, according to the present invention, a cylindrical portion can be fitted into a cutting groove formed in an annular shape on the outer surface of the buried pipe to a depth halfway through the pipe's thickness, and a gripping portion extends from the side opposite to the side into which the cylindrical portion is fitted. With this configuration, when the gripping portion is swung, force can be applied to the inner portion surrounded by the cutting groove in a direction along the inner wall of the cylindrical portion towards the pipe wall.

[0013] Furthermore, in addition to the above effects, the present invention has an entry-preventing structure located behind the open end of the cylindrical part that prevents the core portion inside the cutting groove from entering. With this configuration, when the buried pipe window opening tool is oscillated with the cylindrical part fitted into the cutting groove to separate the core portion from the buried pipe, the entry of the core portion can be prevented at a certain depth of the cylindrical part. This makes it possible to easily remove the separated core portion from the buried pipe window opening tool. In addition, it is possible to prevent the tip of the cylindrical part from entering the inside of the buried pipe more than necessary during the oscillating operation, thus preventing the tip of the cylindrical part from interfering with cables placed inside the pipe.

[0014] Furthermore, according to the present invention, in addition to the above effects, the inner wall of the radially cut surface of the cylindrical portion is formed in a circular shape. As a result, the cylindrical portion is fitted so as to be in close contact with the outer circumference of the core portion which has been cut into a circular cross-section by a rotary tool such as a hole saw. Therefore, pressing force is more easily transmitted from the inner wall of the cylindrical portion to the periphery of the core portion. In addition, a notch is formed in part of the outer wall of the cut surface of the cylindrical portion. As a result, a gap is formed between the outer wall portion of the cylindrical portion where the notch is formed and the cutting groove, so interference between the buried pipe and the outer wall of the cylindrical portion is reduced. Therefore, it becomes possible to swing the buried pipe window opening tool while applying force only to the core portion.

[0015] Furthermore, according to the present invention, in addition to the above effects, since at least one of two opposing regions of the inner wall of the cylindrical portion has a slip-prevention structure for the core portion, when the buried pipe window opening tool is swung toward the region having the slip-prevention structure, it becomes possible to apply force from the cylindrical portion to the outer circumference of the core portion more reliably without causing force transmission loss due to slippage. [Brief explanation of the drawing]

[0016] [Figure 1] This is an overall perspective view showing the buried pipe window opening tool of the present invention. [Figure 2] Figure 1 is a plan view of the buried pipe window opening tool. [Figure 3] It is a sectional view taken along line A-A cut in the plan view of FIG. 2. [Figure 4] It is a view showing the usage state of the buried pipe window opening tool. [Figure 5] It shows the window opening operation using the cylindrical portion, and (a) is a sectional view explaining the operation when the swing center is inside the core portion, and (b) is a sectional view explaining the operation when the swing center is outside the core portion. [Figure 6] It shows a modified example of the buried pipe window opening tool of FIG. 1, where (a) is an overall perspective view, (b) is a right side view, and (c) is an enlarged perspective view of the opening side of the cylindrical portion. [Figure 7] It is a view showing a pipe hole opening jig for checking the inside of a conventional pipe.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the buried pipe window opening tool according to an embodiment of the present invention will be described with reference to the drawings.

[0018] FIG. 1 is an overall perspective view showing the buried pipe window opening tool 1 of the present invention.

[0019] The buried pipe window opening tool 1 has a substantially cylindrical outer shape. This buried pipe window opening tool 1 is used to open a window on the side to check the internal situation of a buried pipe through which a cable or the like is passed. In the window opening operation using the buried pipe window opening tool 1, a tool capable of forming an annular groove like a hole saw is used in combination. A cylindrical portion 2 is formed at one end of the buried pipe window opening tool 1, and a peeling portion 6 is formed at the other end. A gripping portion 4 for an operator to grip is formed between the cylindrical portion 2 and the peeling portion 6. Inside the buried pipe window opening tool 1 according to the present embodiment, a cavity is formed up to the vicinity of the gripping portion 4. The specific internal structure will be described later using FIG. 3 showing a cross section. A step portion 8 is formed from the opening end of the cylindrical portion 2 toward the inner side, and the inner diameter from the step portion 8 toward the inner side is smaller.

[0020] ​

[0021] The peeling portion 6 at the other end is composed of a semicircular disc portion 6a and a slit 6b. The semicircular disc portion 6a is formed so as to align with the direction of the central axis of the cylindrical center of the gripping portion 4. The slit 6b is formed so as to separate the end of the gripping portion 4 from the semicircular disc portion 6a.

[0022] Figure 2 is a plan view of the buried pipe window opening tool 1 shown in Figure 1. As can be seen in Figure 2, the semicircular disc portion 6a of the peeling portion 6 has an inclined surface formed on the inside (towards the slit 6b) along the arc-shaped edge.

[0023] Figure 3 is a cross-sectional view taken along line AA in the plan view of Figure 2.

[0024] In the configuration according to this embodiment, the cylindrical portion 2, the inside of the gripping portion 4, and the peeling portion 6 are integrally formed from a single component. Here, the surface of the gripping portion 4 is shown to be covered with a gripping member, but a simpler configuration without this gripping member is also acceptable.

[0025] As can be seen in Figure 3, in the internal structure of the buried pipe window opening tool 1, a cavity is formed in an area that occupies more than half of the gripping portion 4, thereby reducing weight. In contrast, the peeling portion 6 side does not have a cavity, ensuring a certain level of rigidity. On the inside of the cylindrical portion 2, as described above, a stepped portion 8 is formed along the entire circumference of the inner wall 2a, further back than the opening end.

[0026] Figure 4 shows the state of use of the buried pipe window opening tool 1.

[0027] Figure 4 shows a state in which an annular cutting groove 100b has been formed in advance on the side surface 100a of the buried pipe 100 using a tool such as a hole saw. The cutting groove 100b is cut to a depth halfway to the thickness of the buried pipe 100. As a result, the core portion 100c formed inside the cutting groove 100b is integrally connected to the buried pipe 100 and remains in a state of being left uncut. The cylindrical part 2 of the buried pipe window opening tool 1 is formed to match the diameter of the hole saw and can be fitted into the cutting groove 100b. Since the cutting groove 100b made by the hole saw is formed on the cylindrically curved side surface 100a, the area in the longitudinal direction is cut deeper than the area in the diameter direction of the buried pipe 100. Therefore, the contact area between the fitted cylindrical part 2 and the cutting groove 100b is larger in the longitudinal direction than in the diameter direction.

[0028] Figure 5 shows the window-opening operation using the cylindrical part 2, with (a) being a cross-sectional view illustrating the operation when the pivot center is inside the core part 100c, and (b) being a cross-sectional view illustrating the operation when the pivot center is outside the core part 100c. Both Figure 5(a) and (b) show the transition of the operation from the initial stage on the left to the finishing stage on the right.

[0029] In the usage method shown in Figure 5(a), the buried pipe window opening tool 1 is operated so that its pivot point is inside the core portion 100c. As described above, the cutting groove 100b made by the hole saw is formed deeper in the longitudinal direction than in the diameter direction. Therefore, buried pipe window opening By swinging tool 1 along the longitudinal direction of the buried pipe 100, the cylindrical part 2 can be gripped most securely against the core part 100c. In cutting operations using a hole saw, if the bottom of the cutting groove 100b is left uncut to the extent that it does not penetrate, repeated stress can be applied to the bottom of the cutting groove 100b by swinging the core part 100c, making it possible to easily cause fatigue failure.

[0030] In the case of Figure 5(a), since the oscillation is repeated evenly in the longitudinal direction, cracks due to fatigue failure occur on both sides of the core portion 100c in the longitudinal direction. When the semicircular disc portion 6a (see Figure 1) of the peeling portion 6, which is provided on the opposite side from the cylindrical portion 2, is inserted into the cracks formed in this way, the core portion 100c can be lifted and separated by lever operation with a portion of it contained in the slit 6b. With this operation, all work is performed around the pipe wall of the buried pipe 100, so it is possible to safely open the window without damaging cables with the cylindrical portion 2 of the buried pipe window opening tool 1. Furthermore, it is possible to reliably remove the core portion 100c from the buried pipe 100 without it falling inside the buried pipe 100.

[0031] In contrast, in Figure 5(b), the buried pipe window opening tool 1 is oscillated along its longitudinal direction, but unlike in Figure 5(a), it is not oscillated evenly, but rather biased to one side. That is, in Figure 5(a), the oscillating operation was performed such that the oscillating center P1 was inside the core portion 100c, whereas in Figure 5(b), the oscillating operation is performed with respect to the oscillating center P2, which is outside the core portion 100c. In this case, the buried pipe window opening tool 1 is oscillated by using one side of the open end of the cylindrical portion 2 in the longitudinal direction as a fulcrum and pressing it against the buried pipe 100. When such an operation is performed, greater stress and strain are generated on the cutting groove 100b side in the region opposite to the fulcrum oscillating center P2 in the longitudinal direction. Therefore, since a crack forms on the opposite side from the pivot center P2, the core portion 100c can be easily separated from the buried pipe 100 by inserting the semicircular disc portion 6a of the peeling portion 6 into the gap formed by the crack, similar to the case in Figure 5(a).

[0032] Here, as shown in Figure 5(b), in the initial stage of the operation shown on the left, fatigue fracture has not yet progressed sufficiently in the groove bottom portion of the cutting groove 100b, so the oscillation range of the core portion 100c is relatively small. For this reason, the pivot point is mainly the oscillation center P2 on the open end side of the cylindrical portion 2 of the buried pipe windowing tool 1. However, as fatigue fracture of the cutting groove 100b progresses, the oscillation range of the buried pipe windowing tool 1 increases, as shown on the right. Then, because the pipe wall of the buried pipe 100 has a certain thickness, interference occurs between the side 100a of the buried pipe 100 and the outer wall 2b of the cylindrical portion 2 (see Figure 1). As a result, the oscillation center changes to a motion that swaps between P2 and P3, so in the finishing stage the core portion 100c is swayed more greatly, and fatigue fracture of the cutting groove 100b is accelerated.

[0033] In reality, it is possible that a combined motion including both oscillation patterns will occur, rather than only one of Figures 5(a) or (b) being selected. However, regardless of which pattern in Figures 5(a) or (b) is used, it is possible to prevent cutting debris generated during the cutting process by the hole saw from entering the buried pipe 100. Thus, according to the present invention, it is possible to safely open a window without affecting the inside of the buried pipe 100.

[0034] <Variation> Figure 6 shows a modified example of the buried pipe window opening tool 1, the buried pipe window opening tool 51, where (a) is an overall perspective view, (b) is a right side view, and (c) is an enlarged perspective view of the opening side of the cylindrical portion 52. The components other than the cylindrical portion 52 are the same as those of the buried pipe window opening tool 1 in Figure 1, and are therefore represented by the same reference numerals.

[0035] Referring to Figure 6(a), it can be seen that the cylindrical portion 52 of the buried pipe window opening tool 51 has two notches 52c formed on the outer wall 52b side. These notches 52c are formed by cutting out the cylindrical outer wall 52b in a planar manner.

[0036] In Figure 6(b), for the sake of clarity, the end face of the cylindrical portion 52 is shown with diagonal lines. As shown in Figure 6(b), the formation of the notch 52c reduces the thickness of the cylindrical portion 52 only in the area of ​​the notch 52c. Furthermore, these notches 52c are formed at opposite positions on the outer wall 52b of the cylindrical portion 52. Because of this formation, when the cylindrical portion 52 of the buried pipe window opening tool 51 is fitted into the cutting groove 100b of the buried pipe 100 as shown in Figure 5, the gap becomes larger only in the area where the notches 52c are formed.

[0037] In contrast, the inner wall 52a of the cylindrical portion 52 is formed to have a substantially circular cross-section, similar to the buried pipe window opening tool 1 in Figure 1. Therefore, when the cylindrical portion 52 is fitted into the cutting groove 100b, the contact state between the inner wall 52a of the cylindrical portion 52 and the core portion 100c of the buried pipe 100 is almost the same as in the configuration of Figure 1, with the inner wall 52a making even contact around the core portion 100c.

[0038] In other words, by forming notches 52c in two opposing outer regions of the cylindrical portion 52 without changing the engagement state with the core portion 100c, a gap can be formed between it and the cutting groove 100b, thereby improving the degree of freedom in the swinging operation in the direction in which the notches 52c are formed. As a result, interference between the cylindrical portion 52 and the buried pipe 100 is reduced, making it less likely for the swing center P3 to occur on the side 100a side as shown in Figure 5(b). Therefore, compared to the case of the buried pipe window opening tool 1, the force transmission loss is reduced by the amount of interference between the outer wall 52b or the notches 52c and the buried pipe 100, thus improving work efficiency.

[0039] Furthermore, as shown in Figure 6(c), the modified buried pipe window opening tool 51 is provided with an anti-slip structure 52d on the back side of the notch 52c on the inner wall 52a of the cylindrical portion 52. This prevents the inner wall 52a from slipping against the outer surface of the core portion 100c when the buried pipe window opening tool 51 is oscillated along the direction in which the notch 52c is formed, thereby enabling efficient force transmission to the core portion 100c. This anti-slip structure 52d may be formed by embossing on the inner wall 52a, or by attaching a material with a higher coefficient of friction than the inner wall 52a.

[0040] As described above, if sufficient strength can be maintained in the cylindrical portion 52, it is possible to improve work efficiency by forming a notch 52c on the outer wall 52b side to secure a space that can freely swing between it and the cutting groove 100b.

[0041] The configuration of the above embodiment is just one example of the present invention, and further modifications are also included as follows.

[0042] (1) In the above embodiment, the stepped portion 8 that prevents the core portion 100c from entering the cylindrical portion 2 is shown as a stepped structure formed so as to protrude inward along the inner wall 2a with a constant width over the entire circumference. However, the structure is not limited to a stepped structure as long as it can prevent the core portion 100c from entering and prevent the cylindrical portion 2 from being inserted into the buried pipe 100. For example, it may be a wall structure that completely blocks the entire surface at a certain position from the open end of the cylindrical portion 2 toward the back. It may also be a lattice-like or bridge-like shielding structure that prevents the core portion 100c from passing through.

[0043] (2) In the above embodiment, an example was shown in which the gripping portion 4 has a cylindrical structure with approximately the same diameter as the cylindrical portion 2. However, it is possible to have a configuration in which the gripping portion 4 extends on the opposite side from the insertion side of the cylindrical portion 2 and allows the cylindrical portion 2 to swing. Therefore, it is acceptable for the cylindrical part 2 to extend in a direction that deviates from the direction in which the center of the cylinder extends. Furthermore, it does not need to be cylindrical in shape.

[0044] (3) In the above embodiment, a modified buried pipe window opening tool 51 was shown as an example in which notches 52c are formed in two opposite regions of the outer wall 52b of the cylindrical portion 52. However, as long as a gap is formed between the cutting groove 100b of the buried pipe 100 and the cylindrical portion 52 to prevent interference during the swinging operation, it is sufficient for the notches 52c to be formed in at least one location.

[0045] Furthermore, the shape of the notch 52c is not limited to a flat shape. It may have an uneven shape as long as it prevents interference with the cutting groove 100b.

[0046] Furthermore, when forming notches 52c in two opposing regions, they do not need to be formed symmetrically. By configuring the cylindrical portion 52 to include regions formed with multiple wall thicknesses, it becomes possible to use different regions according to the pipe thickness of the target buried pipe, thereby improving versatility. Also, even with the same buried pipe, it is possible to use regions with different wall thicknesses depending on the progress of the work stage.

[0047] (4) In the above embodiment, a configuration in which the cylindrical portion 2, the gripping portion 4, and the peeling portion 6 are integrally formed from a single member was shown as an example. However, the same effect can be obtained even if they are made from separate members. [Industrial applicability]

[0048] The buried pipe window opening tool of the present invention is useful in a wide range of fields beyond cable piping because, in addition to not damaging installed objects inside the pipe, it can remove the core portion (part of the pipe wall) without letting it fall into the pipe. [Explanation of Symbols]

[0049] 1. Tool for opening buried pipe windows 2. Cylindrical part 2a inner wall 2b Exterior wall 4 Grip part 6. Peeling section 6a Semicircular disc section 6b Slit 8 Step Difference Part (Entry Prevention Structure) 51 Embedded Pipe Window Opening Tool 52 Cylindrical Part 52a Inner Wall 52b Outer Wall 52c Notch Part 52d Anti-Slip Structure 100 Embedded Pipe 100a Side Surface 100b Cutting Groove 100c Core Part P1, P2, P3 Swing Centers

Claims

1. A tool for opening windows in the side of buried pipes, A cylindrical portion that can be fitted into a cutting groove formed by cutting an annular shape to a mid-depth of the pipe thickness on the side surface, It comprises a gripping portion extending to the side opposite to the insertion side of the cylindrical portion, The cylindrical portion has an entry-blocking structure located further inside than the open end, which prevents the inner core portion of the cutting groove from entering. The buried pipe window opening tool is characterized in that the cross-sectional shape obtained by cutting the cylindrical portion radially is formed by a circular inner wall and an outer wall with a notch formed in a part of it.

2. The buried pipe window opening tool according to claim 1, characterized in that the inner wall has a slip-prevention structure for the core portion in at least one of two opposing regions.

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