JP2793056B2 - Cast iron tube crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for replacing an existing pipe, such as an existing cast iron pipe, which has been buried, with a new pipe by digging without excavation. To cover with a conduit and finely crush and recover the cast iron pipe end face,
The present invention relates to a cast iron tube crusher.

[0002]

2. Description of the Related Art In an old pipe replacement method in which an old pipe, such as a buried cast iron pipe, is replaced with a new cast iron pipe by uncutting, a buried cast iron pipe is removed by a roller bit in order to remove the buried existing cast iron pipe. A crushing apparatus for a cast iron pipe comprising crushing from an end face and collecting fragments generated by the crushing is disclosed in JP-A-1-121,497, JP-A-2-140,395, JP-A-2-140,394 and JP-A-2-2. -140,396, etc., and have been used conventionally.

FIG. 2 is a longitudinal sectional view showing an example of a conventional non-cutting cast iron pipe crushing apparatus, and FIG. 3 is a sectional view taken along line AA of FIG. As shown in FIG. 2 and FIG. 3, the conventional non-cutting cast iron pipe crushing apparatus has a front pipe 7 integrally formed at the tip with a larger inner diameter than the outer diameter of the joint 9 of the existing cast iron pipe 1 as an old pipe. A propulsion tube 4 is provided which is fixed in a fixed manner. And the front pipe 7
A plurality of roller bits 3 are rotatably mounted on the inner peripheral surface at predetermined intervals along the circumferential direction.
Crushing of the cast iron pipe is performed as described below. That is, the roller bit 3 which is fitted to the outside of the cast iron pipe 1 while rotating the propulsion pipe 4 forward from the rear while rotating, is pressed against the pipe end face 2 of the cast iron pipe 1 and revolves while rotating. The pipe end face 2 of the cast iron pipe 1 is crushed. At the tip of the propulsion pipe 4, a cylindrical guide 5 having a diameter slightly smaller than the inner diameter of the cast iron pipe 1 is provided, which is in contact with the inner peripheral surface of the cast iron pipe 1. A scraper 15 is provided in front of the roller bit 3.
Is attached to the propulsion pipe 4, and among the fragments of the cast iron pipe 1 generated by being crushed by the roller bit 3,
What has entered the cast iron pipe 1 is conveyed rearward by an inner rib 6 provided on the inner surface of the propulsion pipe 4 by a scraper 15. Also, the debris that entered between the cast iron pipe 1 and the front pipe 7
As the propulsion pipe 4 advances, it enters into the gap between the plurality of roller bits 3 provided at equal intervals along the circumferential direction, and then enters between the cast iron pipe 1 and the propulsion pipe 4 to form the scraper 15.
It will be collected by.

FIG. 11 is a perspective view showing an example of a roller bit. The roller bit 3 has a truncated conical shape as shown in FIG. 11, and a plurality of crushing blades 8 having an acute angle in cross section in the axial direction are provided on the outer periphery thereof. And
The extension of the blade surface of the crushing blade 8 of the roller bit 3 is provided so as to coincide with the center of the propulsion pipe 4. FIG. 4 is a longitudinal sectional view showing a conventional method of mounting a roller bit, and FIG.
Is a cross-sectional view. The reason why each of the roller bits 3 is provided in this manner is that the crushing blade 8
This is to prevent slippage between the outer diameter side and the inner diameter side of the cast iron tube 1. In addition, since the earth and sand between the cast iron pipe 1 and the leading pipe 7 can be broken by the roller bit 3,
As shown in FIG. 4, the angle θ on the movement direction side formed by the extension of the center line of the roller bit 3 and the center axis of the propulsion pipe 4 is 90 °.
It's bigger.

[0005]

The above-described conventional cast iron pipe crushing apparatus has the following problems. FIG.
FIG. 7 is a longitudinal sectional view showing a case where a conventional cast iron tube crushing device crushes a cast iron tube from a socket of a joint portion, and FIG. 7 is a longitudinal section showing a case where a conventional roller bit crushes a cast iron tube from an inlet of a joint portion. FIG. That is, as shown in FIG. 6, when the cast iron pipe 1 is crushed by the roller bit 3 and the joint portion 9 including the receiving port 10 and the insertion port 11 of the cast iron pipe 1 comes in the moving direction of the propulsion pipe 4. In the case where the currently crushed cast iron pipe 1 has the receiving port 10, the receiving port 10 may be crushed as it is. At this time, the pipe end of the outlet 11 is crushed.

On the other hand, as shown in FIG. 7, when the joint 9 of the cast iron pipe 1 comes in the moving direction of the propulsion pipe 4 during the crushing by the roller bit 3, the opening is inserted into the currently crushed cast iron pipe 1. In the case where 11 is provided, the pipe 11 is crushed first from the insertion port 11, so that the pipe end of the receiving port 10 is crushed, and a crack 13 is formed in the neck portion 12 of the receiving port 10 in the circumferential direction. Further, when the cast iron pipe 1 is significantly deteriorated, the cracks 13 may further extend in the axial direction. For this reason, since the shape of the crushed piece becomes large, the crushed piece is caught by the scraper 15 and there is a problem that it cannot be collected. Further, the crushed pieces are caught between the outer surface of the cast iron pipe 1 and the leading pipe 7, so that the propulsion pipe 4 cannot rotate. If the crushed pieces are larger than the interval pitch of, the pieces cannot be collected without moving because they only rotate at a certain place without being caught by the inner surface ribs 6, and the next crushed pieces will stay there, causing the blockage. There was a problem of becoming.

Therefore, when the roller bit 3 approaches the joint 9 (known by measuring the joint distance in the pipe in advance), the operation of the propulsion pipe 4 is performed while paying attention to the generation of the crack 13 and suddenly. When the propulsion force decreases, it is determined that the crack 13 has occurred, and operations such as reverse rotation of the propulsion pipe 4 and repetition of retreating and forward movement, and coping with a person entering the pipe are performed. And the efficiency of the operation is reduced.

Further, the crack 13 generated in the circumferential direction is not uniform in the direction perpendicular to the axis of the propulsion pipe 4 as a matter of course.
Due to the unevenness, another crack 13 is generated again starting from the position where the crushing blade 8 of the roller bit 3 hits. Therefore, when such a circumferential crack 13 occurs, an operation is performed in which the rotational speed of the propulsion pipe 4 is significantly reduced and the roller bit 3 is advanced slightly to avoid the occurrence of a secondary crack in the circumferential crack 13 of the roller bit 3. And so on, which also led to a decrease in work efficiency.

[0009] When the old pipe replacement work is actually performed, as a matter of course, as shown in Fig. 6, a vertical shaft is selected so as to be crushed from the receptacle 10 of the joint portion, and the work is started. As shown in FIG. 8, some cast iron pipes have pipes without joints (receptacles) on the way as shown in FIG. 8, so they have to be crushed from the outlet 11 on the way as shown in FIG. Disappears.

The reason why the crack 13 is generated and broken in the case shown in FIG. 7 is considered as follows. FIG. 9 is a longitudinal sectional view illustrating a force applied to a receiving port when a conventional roller bit crushes a cast iron pipe from a receiving port of a joint. That is, as shown in FIG.
When the roller bit 3 approaches from the 11 side toward the receiving port 10 side, it is inserted into the receiving port 10 by the force of the roller bit 3.
The sealant 14 made of lead, asbestos, etc., interposed between the plug 11 and the plug 11 is broken, and the transmission of force between the receptacle 10 and the outlet 11 is lost. Thereafter, when the receptacle 10 is a roller bit 3 crushing, force F is exerted by the roller bit 3 the receptacle 10, the force component F ₁ perpendicular outer surface direction of propulsion by the force F is generated, the component force F ₁ is receptacle Pushing 10 outwards causes a crack 13 in neck 12.

On the other hand, on the other hand, it is inserted from the receptacle 10 of the joint part.
When the roller bit 3 approaches 11, the sealing agent 14 is broken by the pressing force of the roller bit 3
Although the transmission of the force between 10 and the outlet 11 is lost, if further crushing is performed, as shown in FIG.
Cracks do not occur because they are separately crushed. FIG.
FIG. 3 is a longitudinal sectional view for explaining a case where a cast iron pipe is crushed from a spout of a joint by a conventional roller bit.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the conventional method of renewing cast iron pipes by non-cutting and to improve work efficiency by collecting small pieces of cast iron pipes without making large cracks. It is an object of the present invention to provide a cast iron tube crushing device that can be improved.

[0013]

SUMMARY OF THE INVENTION The present invention provides a propulsion pipe having an inner diameter larger than the outer diameter of a crushed cast iron pipe and having a front pipe integrally fixed to a tip thereof and an inner peripheral surface of the front pipe. A plurality of roller bits having a frusto-conical shape, provided with crushing blades on the outer circumference thereof, rotatably attached at predetermined intervals along the circumferential direction, and comprising a plurality of roller bits. A cast iron tube crushing device for crushing the crushed cast iron tube by the roller bit that is pressed against the end face of the crushed cast iron tube and revolves while rotating while pushing forward while rotating the propulsion tube while being fitted to the outside of the cast iron tube. In the moving direction side angle formed by the extension line of the blade surface of the crushing blade of each of the roller bits in contact with the end surface of the crushed cast iron pipe and the center axis of the propulsion tube is 90 ° or less. Also have features It is.

[0014]

The angle between the extension of the crushing blade 8 of the roller bit 3 in contact with the crushing surface of the crushed cast iron pipe 1 and the central axis of the propulsion pipe 4 is set to 90 ° or less. Therefore, when the propulsion pipe 4 is advanced from the outlet 11 toward the receiving port 10, the force of the receiving port 10 of the cast iron pipe 1 received from the roller bit 3 acts from the outer periphery toward the center, and
Cracks do not occur in the neck portion 12 of 10 and crushed pieces do not become large. Therefore, the propulsion pipe 4 does not become unrotatable, and crushed pieces that are not collected stay in the inner rib 6 and are not closed.

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing one embodiment of a cast iron pipe crushing apparatus according to the present invention by non-cutting. FIG. 1 shows that the roller bit 3 has a joint 9 composed of an insertion port 11 and a receiving port 10.
This shows a state in which the cast iron pipe 1 is moving from the insertion port 11 to the receiving port 10 while crushing the cast iron pipe 1. The cast iron pipe crushing apparatus shown in FIG. 1 differs from the conventional cast iron pipe crushing apparatus shown in FIG. 2 only in that the position where the roller bit 3 is provided is different from the position where the conventional roller bit 3 is provided, as described later. Is different. As shown in FIG.
In the cast iron pipe crushing apparatus of the present invention, the angle θ on the moving direction side formed by the extension line of the blade surface of the crushing blade 8 of each roller bit 3 contacting the pipe end face 2 of the cast iron pipe 1 and the central axis of the propulsion pipe 4 is set. , 90
° or less.

By providing the roller bit 3 at such an angle, cracking of the cast iron pipe 1 does not occur as in the prior art. The reason is as follows. That is, the force F applied to the crushed surface of the cast iron pipe 1 by the roller bit 3
As shown in FIG. 1, toward the cast iron pipe center direction, divided into a component force F ₂ in the propulsion direction perpendicular surface of this. This component force F ₂ is because it is towards the cast iron pipe center direction, receptacle 10 of cast iron pipes 1 is because the roller bit 3, will receive a force toward the center from the outer periphery. Also,
Since the cast iron pipe 1 itself has a lower tensile rupture stress than the compressive rupture stress, and the receiving port 10 itself has a flaky shape, the receiving port 10 has a low force when a force directed outward from the center acts. Although it is easy to enter, it can withstand a large force when a force toward the center acts from the outside. If the roller bit 3 as described above is provided in consideration of such a property of the receiving port 10 of the cast iron pipe, the joint 9 does not crack.

[0017]

As described above, according to the present invention, according to the present invention, the roller bit 3 applies a force to the end face of the cast iron tube 1 in the direction perpendicular to the axis of the cast iron tube so as to be directed toward the center of the shaft. Since the bit 3 is provided, a crack is not formed in the neck portion of the joint receiving portion during the renewal work of the old pipe due to the non-cutting, and the work can be completed efficiently, and thus an industrially useful effect is brought. It is.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an example of a conventional cast iron pipe crushing apparatus.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a conventional method of mounting a roller bit.

FIG. 5 is a cross-sectional view showing a conventional roller bit mounting method.

FIG. 6 is a longitudinal sectional view showing a case where a cast iron pipe is crushed from a socket of a joint portion by a conventional roller bit.

FIG. 7 is a longitudinal sectional view showing a case where a cast iron pipe is crushed from an inlet of a joint portion by a conventional roller bit.

FIG. 8 is a side view showing the state of burying a cast iron tube.

FIG. 9 is a longitudinal sectional view illustrating a force applied to a receiving port when a cast iron pipe is crushed from a receiving port of a joint portion by a conventional roller bit.

FIG. 10 is a longitudinal sectional view illustrating a case where a cast iron pipe is crushed from a spout of a joint part by a conventional roller bit.

FIG. 11 is a perspective view showing an example of a roller bit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cast iron pipe 2 Cast iron pipe end face 3 Roller bit 4 Propulsion pipe 5 Guide 6 Inner rib 7 Front conduit 8 Crushing blade 9 Joint part 10 Reception port 11 Insert port 12 Neck part 13 Crack 14 Sealant 15 Scraper

────────────────────────────────────────────────── ─── Continuing on the front page (72) Yoshikazu Nakajima, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Masaaki Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan (72) Inventor Hiroshi Shima 5-9-1 Nishihashimoto, Sagamihara City, Kanagawa Prefecture New Nippon Steel Corporation Steel Structure Marine Division (72) Inventor Yasuyuki Fujisaki 5-9- Nishihashimoto, Sagamihara City, Kanagawa Prefecture 1 New Nippon Steel Corporation Steel Structure Offshore Division (72) Inventor Tetsuo Kimura 2-3-6 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corporation (72) Inventor Minoru Kakizaki Major in Chiyoda-ku, Tokyo 2-6-3, Nachi-cho, Nippon Steel Corporation (56) References JP-A-3-144184 (JP, A) JP-A-4-122798 (JP, U) (58) Fields surveyed (In t.Cl. ⁶ , DB name) E21D 9/06 311

Claims (1)

(57) [Claims] 1. A propulsion pipe having an inner diameter larger than the outer diameter of a crushed cast iron pipe and having a leading conduit integrally fixed at a tip thereof,
A plurality of roller bits having a frusto-conical shape, provided with crushing blades on the outer circumference thereof, rotatably mounted on the inner circumferential surface of the leading conduit along its circumferential direction at predetermined intervals, and provided with crushing blades on the outer circumference thereof. The crushed cast iron is inserted by fitting the leading conduit outside the crushed cast iron pipe, and moving the propulsion pipe forward while rotating it, while being pressed against the end face of the crushed cast iron pipe and revolving while rotating. In a cast iron pipe crushing device for crushing a pipe, an angle on a moving direction side formed by an extension line of a blade surface of a crushing blade of each of the roller bits in contact with an end surface of the crushed cast iron pipe and a central axis of the propulsion tube. Is 90 ° or less.