JP4421509B2 - Prevention of iron pipe deformation - Google Patents

Description

  The present invention relates to a deformation prevention tool for a large-diameter iron pipe used as a distribution pipe (including a drain pipe) buried in the ground and a deformation prevention structure thereof.

Large diameter steel pipes having a diameter of 900 to 1800 or more are used in waterways such as water and sewage systems, agricultural water distribution channels, and industrial drainage channels. The iron pipe is usually manufactured and stocked (stored) in a factory, transported to the site as needed, and also stocked for a certain period of time on the site.
At that time, the large-diameter iron pipe is deformed by its own weight when stocking, or deformed by vibration during transportation. In addition, due to today's demand for cost reduction, iron pipes are also becoming thinner, and the degree of deformation is increasing.
If the deformation is on the insertion port side or on the reception port side, due to the difference in diameter between the two steel pipes (insertion of the insertion port into the reception port) is not smoothly performed, or in the worst case, It may not be possible to join.
In that case, the deformation | transformation is corrected with various deformation correction apparatuses (refer patent document 1 etc.).
Japanese Patent Laid-Open No. 11-10231

However, if the iron pipe has a large diameter, the deformation correction device is also enlarged, leading to an increase in cost, and the correction work is troublesome.
For this reason, conventionally, as shown in FIG. 6 and FIG. 7, the seats 1 made of sleepers or the like are provided on the plurality of opposed surfaces on the inner periphery in the opening (insertion or receiving port) of the iron pipe T, respectively. A wooden square 2 is provided between both receiving seats 1 and 1 of each facing surface, and a wooden wedge (arrow) 3 is driven between one end of the square 2 and the receiving seat 1 so that the facing surface of the iron pipe T is provided. The required tension is applied to prevent deformation. In the figure, t is a mortar layer.

Moreover, there exists a thing which rotates a pipe | tube with a roller as a deformation | transformation prevention apparatus at the time of pipe | tube stock in a factory and the field (refer patent document 2).
JP 2003-307284 A

In the case of the above-mentioned conventional wooden slab 2, the slab 2 is not sufficiently dried, or expands and contracts due to wetness and drying due to rain, etc., and the tension changes due to the expansion and contraction, and the deformation prevention force decreases due to repetition. In the worst case, the expansion force of the wedge 3 is lost and the square member 2 may fall off. If it falls off, the deformation prevention force will not work at all.
For this reason, conventionally, a means for preventing the falling off of the square member 2 due to the loosening of the wedge 3 is taken by, for example, nailing the wedge 3 to the receiving seat 1.

  However, if the nails are fastened, there arises a problem that it becomes difficult to finely adjust the opposing surfaces after the square member 2 is mounted, and the operation of removing the nails is troublesome at the time of dismantling, and the square member 2 is generally cut with a saw. is doing. For this reason, it is almost impossible to reuse the square bar 2 once used, and there is a problem of environmental load due to an increase in waste.

  Furthermore, the adjustment of the length between the opposing surfaces by the wedge 3 requires highly skilled skills, and it is difficult to secure the personnel. For this reason, when the square member 2 is mounted, the wedge 3 has a small driving force (amount) and the wedge 3 falls off, or conversely, an accident such as deformation of the iron pipe T due to excessive driving of the wedge 3 occurs. ing.

  On the other hand, the pipe deformation preventing device described in Patent Document 2 is large and has a problem in cost.

  In view of the above circumstances, it is an object of the present invention to make it possible to easily and stably fix a tension between opposing surfaces of an inner periphery of an iron pipe.

In order to achieve the above object, according to the present invention, the opposing surfaces on the inner periphery of the iron pipe are fixed with a screw jack.
The screw jack can be easily expanded and contracted manually or the like, and adjustment of the expansion / contraction degree can be easily and easily performed without requiring skill.
Further, the screw jack has less slackness in the tensioned state than the tension due to the wedge driving. For this reason, compared with prevention of deformation of the square member 2 and the wedge 3, the prevention function is stable.
Furthermore, at the time of joining the iron pipe, the iron pipe can be corrected by the expansion and contraction of the screw jack, and the joining action becomes easy.

  In the present invention, as described above, the inner surface of the iron pipe is stretched by the screw jack to prevent the deformation thereof. Therefore, the structure is inexpensive, the operation is easy, and the prevention action is also provided. Stabilize.

As one embodiment of the present invention, in the iron pipe deformation prevention device provided between the opposing surfaces of the inner periphery of the iron pipe, the device includes a receiving seat pressed against each of the opposing surfaces, and a screw jack provided between the receiving seats. It is possible to adopt a configuration in which the length between the seats is adjusted and fixed at an arbitrary length by expansion and contraction of the screw jack to prevent deformation of the iron pipe.
The iron pipe deformation preventing device having this configuration is provided radially on the inner surface of the iron pipe (provided radially inside the iron pipe at a required interval around the iron pipe) to prevent deformation by stretching the circumference of the iron pipe with substantially the same force. The radial installation mode is, for example, the inner periphery of the iron pipe, equal intervals such as 90 degrees and 60 degrees, and mixing intervals such as 120 degrees and 60 degrees.

Further, as another embodiment, a seat is provided at a required position on the inner periphery of the iron pipe, a seat is provided at the center of the iron pipe, and a screw jack is provided between the center seat and each seat on the inner surface of the iron pipe, It is possible to adopt a configuration in which the length between the seats is adjusted and fixed at an arbitrary length by expansion / contraction / fixation of the screw jack to prevent deformation of the iron pipe.
When the iron pipe deformation prevention device of this configuration is provided on the inner surface (inner side) of the iron pipe, it has a screw jack in its radial direction, and the extension of each screw jack stretches the required position around the iron pipe with almost the same force. To prevent deformation. The required position is, for example, the inner circumference of the iron pipe, equal intervals such as 90 degrees and 60 degrees, and mixing intervals such as 120 degrees and 60 degrees.

In these iron pipe deformation prevention devices, commercially available various types of screw jacks can be used. For example, a screw rod provided on one receiving seat, a handle screwed into the screw rod, and the other It is possible to employ a configuration comprising a support tube provided in the seat.
In this screw jack, the support tube is fitted into the screw rod so as to be able to advance and retract, and the tip of the screw jack contacts the handle screwed into the screw rod, and the handle tube is rotated to advance and retract the screw tube. With the progress of the support pipe, both the seats are stretched and the opposing surfaces of the iron pipe are stretched to prevent deformation.

  At this time, assuming that a fixing tool is screwed into one seat side of the handle of the screw rod, after adjusting the tension by the handle, when the fixing tool is pressed against the handle, a double nut structure is formed, Make sure to prevent slack. Locking by this fixing tool is effective when receiving vibration during transportation or the like.

  Further, if the support tube is detachable from the other receiving seat, there is an advantage that the receiving seat and the supporting tube can be moved separately. Since the support tube is long compared to other objects, it is preferable that the support tube be short during movement.

  Furthermore, if the seat is divided into a plurality of portions in the circumferential direction of the iron pipe, it can be adapted to follow the inner surface of the iron pipe by changing the gap of the divided surface as the inner surface of the iron pipe is pressed. In addition, damage due to the pressure contact of the inner surface of the iron pipe, particularly when there is a mortar layer, can be eliminated.

One embodiment is shown in FIGS. 1 to 3, and the iron pipe deformation prevention tool A of this embodiment has a seat 21 at the end in the expansion / contraction direction that is in pressure contact with the opposing surface of the inner circumference of the cylindrical iron pipe T made of ductile cast iron. And a screw jack 10 provided between the two seats 21.
The screw jack 10 includes a screw rod 11 screwed to one receiving seat (lower receiving seat in FIG. 3) via a receiving plate 11a, a handle 12 screwed into the screw rod 11, and a handle 12 And a support tube 14 provided on the other receiving seat 21.
The support tube 14 was a steel tube having a diameter of 48.6 × thickness: 2.3 mm. With this support tube 14, the tensioning action of the iron pipe T, which will be described later, can be reliably ensured against the expansion and contraction of the screw jack 10. By appropriately selecting the length of the support pipe 14, it corresponds to each iron pipe T having a different nominal diameter.

The seat 21 is made of wooden sleepers, and is made of two square members 21a and 21b having a 60 × 60 mm square and a length of 120 to 300 mm. By setting this size and setting the length direction to the tube axis direction, the inner surface of the iron pipe T having a diameter of φ900 to 2600, particularly the mortar layer t is effectively protected.
A receiving cylinder 15 is screwed to the other receiving seat 21 via a receiving plate 15a, and the support tube 14 is detachably fitted to the outer surface of the receiving cylinder 15.

Each seat 21 is two square bars 21a, by consisting 21b, As the pressure of the inner surface of the iron pipe T, as shown in chain line 3, the receiving plate 11a, while 15a is bent two square bars 21a , 21b extends along the inner surface of the iron pipe T by changing the gap of the split surface. For this reason, damage due to pressure contact of the seat 21 on the inner surface of the iron pipe T is further prevented as much as possible. If the outer surface of the receiving seat 21 (the upper side surface of the upper receiving seat 21 in FIG. 3 and the lower side surface of the lower receiving seat 21 in FIG. 3) is an arc surface, the degree of alignment along the inner surface of the iron pipe T can be increased. Further, if the receiving seat 21 is fixed to the receiving plates 11a and 15a loosely (so that it can move a little like a chain line), the receiving seat 21 can easily follow the inner surface of the iron pipe T.

  Further, the receiving tube 15 and the support tube 14 are supported if the pin 16 of the support tube 14 is fitted into the L-shaped locking hole 17 of the receiving tube 15 and locked as shown by a chain line in FIG. The receiving seat 21 can be attached and fixed to the pipe 14, and the transportation and loading work to the iron pipe T is facilitated. In this figure, the support tube 14 is fitted to the inner surface of the receiving tube 15, but if the pin 16 is provided on the inner surface of the support tube 14, the support tube 14 is fitted to the outer surface of the receiving tube 15.

  In the iron pipe deformation preventing device A of this embodiment, as shown by a chain line in FIG. 3, the support tube 14 is fitted into the screw rod 11, the tip is brought into contact with the handle 12, and the receiving tube 15 is fitted into the support tube 14. Then, by turning the handle 12, the support tube 14 (the other receiving seat 21) is assembled with respect to the screw rod 11 so that it can be advanced and retracted.

  As shown in FIGS. 1 and 2, the iron pipe deformation preventing device A assembled in this way is provided inside the iron pipe T in the radial direction at equal intervals around the steel pipe T, and the support pipe 14 is advanced by turning the handle 12 to receive both seats. A required tension is given between 21 and 21, and the circumference equidistant position of the iron pipe T is stretched by substantially the same force, and the deformation of the iron pipe T is prevented. Once the required tension is obtained, the fixture 13 prevents the tension (handle 12) from loosening.

FIG. 4 shows another embodiment. In this embodiment, a receiving seat 21 made of sleepers is provided at equal intervals on the inner periphery of the iron pipe T, and a receiving seat 31 is provided at the center of the iron pipe T. A screw jack 10 is provided between 31 and each seat 21 on the inner surface of the iron pipe T.
Similarly to the screw jack 10 of the above embodiment, the screw jack 10 of this embodiment also has a screw rod 11 screwed to the seat 31 of the iron pipe T, and a handle 12 and a fixture 13 screwed into the screw rod 11. And the support tube 14 provided on the other receiving seat 21, etc., and the operation is the same.

  Similarly, in the iron pipe deformation preventing device A of this embodiment, the support tube 14 is fitted into each screw rod 11, the tip thereof abuts on the handle 12, and the handle is turned to turn the support tube 14 against the screw rod 11. Assemble in a state that can be advanced and retracted.

As shown in FIG. 4, the iron pipe deformation prevention device A assembled in this way is set inside the iron pipe T, and then rotates each handle 12 to advance each support pipe 14 so that both seats 21 are connected to the iron pipe T. The inner surface is pressed against the inner surface, and evenly spaced positions around the iron pipe T are stretched with substantially the same force to prevent deformation. At this time, similarly, each fixture 13 prevents the looseness of the tension.
In this embodiment, the screw rod 11 can be provided on each receiving seat 21 side, and the receiving tube 15 can be provided on the center receiving seat 31.

  In each of the above-described embodiments, the receiving seat 21 is applied to the quartile around the inner surface of the iron pipe T. As shown in FIG. As shown in (b), the octile, decile, etc. are arbitrary. 5 (a) and 5 (b) show the case of the iron pipe deformation preventing device A shown in FIG. 3, but the iron pipe deformation preventing device A shown in FIG. 4 has a seat 31 at the center of the iron tube T in each drawing. It is only necessary to provide a screw jack 10 or the like extending radially from the receiving seat 31 as shown in FIG. 4, and in this embodiment, odd-numbered quantiles such as tertiles are also possible.

[Experimental example]
When the ductile cast iron straight pipe having a nominal diameter of φ1800 is prevented from being deformed in the form shown in FIG. 5B by the iron pipe deformation preventing device A of the embodiment shown in FIG. 3, the square material (wooden reinforcing frame) 2 shown in FIG. Table 1 below shows the change in diameter of the lower steel pipe T at the measurement points a to d shown in FIG. 5 when the two-stage ship was transported from Osaka to Tomakomai. Show. In the table, “after draining” means “after the steel pipe T is lowered from the ship to the land and transported and stored in a predetermined place”.

In the comparison between the wooden reinforcing frame (square member 2) shown in FIGS. 6 and 7 and the example in this experimental example, in the “wooden reinforcing frame”, the diameter of the iron pipe T has a variation of 9 mm (a and c) before the frame is mounted. It was within the allowable range, and the installation and correction of the wooden frame by a skilled worker improved it to 2 mm after installation. It has increased to the limit of the tolerance.
This suggests that there may be iron pipes that need to be re-corrected with wooden reinforcement frames. For re-correction, it is necessary to send a skilled worker to the piping construction site, resulting in a tremendous cost increase.

On the other hand, in the “Example”, the diameter of the iron tube T had a variation of 8 mm (between a and c) before the frame was mounted, and there was a part exceeding the allowable range (for example, a part). By mounting / correcting the deformation prevention tool A in the example, the variation was improved to 1 mm after mounting, and even after draining, the variation increased to 2 mm (between b and d) but remained within the allowable range. ing.
This suggests that once the attachment / correction using the deformation prevention tool A of the embodiment is performed, the effect is maintained until after draining, and it is unlikely that re-correction is required at the site of piping construction. . Even if re-correction is necessary, in the case of the deformation prevention tool A of the embodiment, the work is easy and the correction dimension (correction amount) is small and the work load (compared to the wooden reinforcing frame) Less work time). The correction work is performed by expansion and contraction of the screw jack 10.

  Incidentally, in the ductile cast iron straight pipe T having a nominal diameter of φ900 smaller than the ductile cast iron straight pipe T having a nominal diameter of φ1800, the deformation of the lower iron pipe in the two-stage stacking is similarly reduced. Moreover, this iron pipe deformation prevention tool A is used repeatedly.

Partial perspective view for explaining the operation of one embodiment Side view of FIG. Exploded perspective view of iron pipe deformation preventing device of the embodiment Side view of another embodiment Examples of other usage modes Partial perspective view of a conventional example Side view of the main part of the conventional example

Explanation of symbols

1, 21 Receiving seat 10 Screw jack 11 Screw rod 12 Handle 13 Fixing tool 14 Support pipe 31 Receiving seat A Iron pipe deformation prevention tool T Iron pipe

Claims (10)

An iron pipe deformation prevention device (A) provided between opposing surfaces of the inner circumference of a cylindrical iron pipe (T), between a receiving seat (21) press-contacted to the opposing surface and both receiving seats (21, 21) A screw jack (10) provided on the steel pipe, and by adjusting the length between the receiving seats (21, 21) by expansion / contraction / fixation of the screw jack (10), the iron jack is fixed to an arbitrary length. preventing deformation of the (T), and said receiving seat (21) includes a plurality of divided members divided into a plurality in the circumferential direction of the iron pipe (T) (21a, 21b), the respective split members ( 21a, 21b) are arranged in the circumferential direction of the iron pipe (T) on the receiving plate (11a, 15a) at the end of the expansion / contraction direction of the screw jack (10), and move by changing the gap between the dividing surfaces. is fixed so as to obtain, as the pressure of the inner surface of the iron pipe (T) , Receiving plate (11a, 15a) and characterized in that is in along the inner surface of each of said split members being bent (21a, 21b) is by changing the gap between the divided surfaces moving iron pipe (T) Iron pipe deformation prevention tool. The screw jack (10) is provided on a screw rod (11) provided on one seat (21), a handle (12) screwed into the screw rod (11), and on the other seat (21). was made from the supporting tube (14), said at supporting pipe (14) crowded fitted retractably on said threaded rod (11), those of the tip to the handle screwed into the threaded rod (11) (12) The iron pipe deformation prevention tool according to claim 1, wherein the support pipe (14) is advanced and retracted with respect to the screw rod (11) by contacting and turning the handle (12).   The iron pipe deformation prevention tool according to claim 2, wherein a fixing tool (13) is screwed into the one seat (21) side of the handle (12) of the screw rod (11).   The iron pipe deformation preventing device according to any one of claims 1 to 3, wherein the support tube (14) is detachably attached to the other receiving seat (21).   An iron pipe deformation preventing structure according to any one of claims 1 to 4, wherein the iron pipe deformation preventing tool (A) is provided radially on the inner surface of the iron pipe (T). A receiving seat (21) is provided at a required interval position on the inner circumference of the iron pipe (T), and a receiving seat (31) is provided at the center of the iron pipe (T). The center receiving seat (31) and the inner surface of the iron pipe (T) A screw jack (10) is provided between each of the receiving seats (21), and the length between the receiving seats (21, 31) is adjusted by the expansion and contraction and fixing of the screw jack (10) and at an arbitrary length. fixed and to prevent deformation of the iron pipe (T), and, receiving seat to be pressed against the iron pipe (T) side (21) has a plurality of divided divided into a plurality in the circumferential direction of the iron pipe (T) Each of the divided members (21a, 21b) is formed in the circumferential direction of the iron pipe (T) on the receiving plate (11a, 15a) at the end in the expansion / contraction direction of the screw jack (10). They are lined up and fixed so that they can move by changing the gaps between their split surfaces. As the pressure plate is pressed against the inner surface of the iron pipe (T), each of the divided members (21a, 21b) is moved while the receiving plates (11a, 15a) are bent, thereby changing the gap between the divided surfaces to change the inner surface of the iron pipe (T). An iron pipe deformation prevention device characterized by being adapted to the above. The screw jack (10) includes a screw rod (11) provided on one of the seats (31, 21), a handle (12) screwed into the screw rod (11), and the other seat (21, 21). become from a support tube provided on 31) (14), said at supporting pipe (14) crowded fitted retractably said to threaded rod (11), said handle screwed to the tip to the threaded rod (11) ( The iron pipe deformation prevention tool according to claim 6 , wherein the support pipe (14) is moved forward and backward with respect to the screw rod (11) by abutting on 12) and turning the handle (12). The iron pipe deformation preventing tool according to claim 7 , wherein a fixing tool (13) is screwed into the one seat (31, 21) side of the handle (12) of the screw rod (11). The iron pipe deformation preventing device according to any one of claims 6 to 8 , wherein the support pipe (14) is detachably attached to the other receiving seat (21, 31). An iron pipe deformation preventing structure comprising the iron pipe deformation preventing device (A) according to any one of claims 6 to 9 provided on an inner surface of the iron pipe (T).

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