JPH0533587A - Cast iron pipe crusher - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a crack and to promote work efficiency by mounting the blade surfaces of roller bits crushing a buried existing pipe so that the angles in a moving direction side are acute angles with respect to the center shaft. CONSTITUTION:A plurality of chopped head conical roller bits 3 are provided on the inside of a pilot pipe 7 having a diameter larger than that of the buried existing piple so that they can rotate. Extension lines of the blade surfaces on crushing blades 8 of the roller bits 3 are so provided that the angles theta in a moving direction side are less than 90. The existing pipe 1 is crushed while rotating and revolving the roller bits 3, and a driving pipe 4 is driven forward. According to the constitution, no crack occurs in the neck section of a socket 10 of the exisiting pipe 1, and the existing pipe can be efficiently crushed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to the outer circumference of a crushed cast iron pipe to be buried, which is used in an old pipe renewal method in which an old pipe, such as a buried existing cast iron pipe, is replaced by a new pipe without cutting. For covering with a conduit and finely crushing the end surface of the cast iron pipe for recovery,
The present invention relates to a cast iron pipe crushing device.

[0002]

2. Description of the Related Art In an old pipe renewal method in which an old pipe such as a buried cast iron pipe is replaced with a new cast iron pipe by non-opening, the buried cast iron pipe is replaced with a roller bit in order to remove the existing buried cast iron pipe. A cast iron pipe crushing device consisting of crushing from the end surface by means of the crushing and recovering the fragments generated by crushing is disclosed in JP-A-1-121,497, JP-A-2-140,395, JP-A-2-140,394 and JP-A-2. -140,396, etc., and has been used conventionally.

FIG. 2 is a vertical sectional view showing an example of a conventional cast iron pipe crushing apparatus by non-open cutting, and FIG. 3 is a sectional view taken along the line AA of FIG. As shown in FIG. 2 and FIG. 3, in the conventional cast iron pipe crushing device by non-cutting, the front conduit 7 is integrated at the tip, which has a larger inner diameter than the outer diameter of the joint portion 9 of the existing cast iron pipe 1 as an old pipe. A propulsion tube 4 that is fixed in place. And the front conduit 7
A plurality of roller bits 3 are rotatably attached to the inner peripheral surface of the roller at predetermined intervals along the circumferential direction.
Crushing of the cast iron pipe is performed as shown below. That is, the front conduit 7 is fitted to the outside of the cast iron pipe 1, while the propelling pipe 4 is rotated and moved forward from the rear, by the roller bit 3 that is pressed against the pipe end surface 2 of the cast iron pipe 1 and revolves while rotating. The pipe end surface 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. In addition, in front of the roller bit 3, a scraper 15
Is attached to the propulsion pipe 4, and among the fragments of the cast iron pipe 1 crushed by the roller bit 3,
What has entered the cast iron pipe 1 is carried backward by the scraper 15 by the inner surface ribs 6 provided on the inner surface of the propulsion pipe 4. Also, the debris that entered between the cast iron pipe 1 and the leading conduit 7
As the propelling pipe 4 advances, after entering the mutual gaps of the plurality of roller bits 3 provided at equal intervals along the circumferential direction, the propelling pipe 4 enters between the cast iron pipe 1 and the propelling pipe 4, and the scraper 15
Will be collected by.

FIG. 11 is a perspective view showing an example of a roller bit. As shown in FIG. 11, the roller bit 3 has a frustoconical shape, and a plurality of crushing blades 8 having an acute cross section in the axial direction are provided on the outer circumference thereof. And
The extension line of the blade surface of the crushing blade 8 of the roller bit 3 is provided so as to match the center of the propulsion pipe 4. FIG. 4 is a vertical cross-sectional view showing a conventional roller bit mounting method, and FIG.
FIG. The reason why each of the roller bits 3 is provided in this way is that the crushing blade 8 is attached to the crushing surface of the cast iron pipe 1.
Is to prevent slippage between the outer diameter side and the inner diameter side of the cast iron pipe 1. Further, since the earth and sand between the cast iron pipe 1 and the front conduit 7 can be broken by the roller bit 3,
As shown in FIG. 4, the angle θ on the moving direction 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 is taken larger.

[0005]

The above-described conventional cast iron pipe crushing device has the following problems. Figure 6
Is a vertical cross-sectional view showing a case of crushing a cast iron pipe from a receiving port of a joint portion by a conventional cast iron pipe crushing device, and FIG. 7 is a vertical sectional view showing a case of crushing a cast iron pipe from a joint port of a conventional roller bit. It is a side view. 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 of the cast iron pipe 1 including the receiving port 10 and the spout 11 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 spigot 11 is crushed.

On the other hand, as shown in FIG. 7, when the joint portion 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 cast iron pipe 1 currently being crushed is spouted. When there is 11, the spout 11 is crushed first, so that the pipe end of the receiving port 10 is crushed, and a crack 13 occurs in the neck portion 12 of the receiving port 10 in the circumferential direction. When the cast iron pipe 1 is significantly deteriorated, the crack 13 may further extend in the axial direction. As a result, the size of the crushed pieces becomes large, and the crushed pieces are caught by the scraper 15 and cannot be recovered. Further, the crushed pieces are sandwiched between the outer surface of the cast iron pipe 1 and the leading conduit 7, so that the propulsion pipe 4 cannot be rotated. If the crushed pieces are larger than the interval pitch of, the inner surface ribs 6 will not rotate and will not move and will not be able to be collected, and the next fragments will stay there, causing a blockage. There was a problem that

Therefore, when the roller bit 3 approaches the joint 9 (which is known by measuring the joint distance in the pipe in advance), the propulsion pipe 4 is suddenly operated while paying attention to the occurrence of the crack 13. When the propulsion force decreases, it is determined that the crack 13 has occurred, and the propulsion pipe 4 is rotated in the reverse direction, and the operation such as repeating the backward movement and the forward movement is performed, and a person enters the pipe to deal with it. However, there is a problem that work efficiency decreases.

The fracture surface of 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.
Since it has unevenness, another crack 13 is generated again starting from the point where the crushing blade 8 of the roller bit 3 hits. Therefore, when such a circumferential crack 13 occurs, the rotation speed of the propulsion pipe 4 is remarkably reduced and the propelling pipe 4 is slightly advanced to perform an operation of avoiding the occurrence of a secondary crack in the circumferential crack 13 of the roller bit 3. Etc. were necessary, which also led to a decrease in work efficiency.

When the old pipe renewal work is actually carried out, naturally, as shown in FIG. 6, the shaft is selected so as to be crushed from the receiving port 10 of the joint portion and the work is started, but it is buried. Depending on the cast iron pipe, as shown in FIG. 8, there is a case where a pipe without a joint (reception port) is inserted in the middle, so as shown in FIG. 7, there is no choice but to crush from the spout 11 from the middle. Disappear.

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 vertical cross-sectional view for explaining the force received by the receiving port when the cast iron pipe is crushed by the conventional roller bit from the receiving port of the joint portion. That is, as shown in FIG.
When the roller bit 3 approaches from the 11 side toward the receiving port 10 side, the force of the roller bit 3 causes the receiving port 10 and the insertion port.
The sealant 14 made of lead, asbestos, or the like, which is interposed between the seal 11 and 11, is broken, and the force transmission between the receiving port 10 and the outlet 11 is lost. After that, when the roller bit 3 crushes the receiving port 10, a force F by the roller bit 3 acts on the receiving port 10, and this force F generates a component force F _{1 in the} direction of the right angle outer surface of the propulsion, and this component force F ₁ By pushing 10 outwards, a crack 13 is created in the neck portion 12.

On the other hand, conversely, from the receiving port 10 of the joint part
When the roller bit 3 approaches toward 11, the pressing force of the roller bit 3 breaks the sealant 14 and
Although the transmission of the force between 10 and the spigot 11 disappears, when further crushing is performed thereafter, as shown in FIG. 10, the spigot 10 and the spigot 11
It will be crushed separately from and will not crack. Figure 10
[Fig. 4] is a vertical cross-sectional view illustrating a case where a cast iron pipe is crushed from an outlet of a joint portion by a conventional roller bit.

Therefore, the object of the present invention is to solve the problems of the conventional method of renewing a cast iron pipe by non-open cutting, and to recover the cast iron pipe with fine fragments without causing large cracks, thereby improving work efficiency. It is to provide a cast iron pipe crushing device that can be improved.

[0013]

DISCLOSURE 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 a tip conduit integrally fixed to the tip, and an inner peripheral surface of the tip conduit. Along the circumferential direction, it is rotatably mounted at a predetermined interval, is provided with a crushing blade on its outer periphery, and is composed of a plurality of truncated cone-shaped roller bits. A cast iron pipe crushing device that is fitted to the outside of a cast iron pipe and is moved forward while rotating the propulsion pipe while being pressed against the end surface of the crushed cast iron pipe and revolving while revolving while rotating around the cast iron pipe In, the extension line of the blade surface of the crushing blade of each roller bit in contact with the end surface of the crushed cast iron pipe, the angle of the moving direction side formed by the central axis of the propulsion pipe is 90 ° or less It also has features Of.

[0014]

The angle between the extension line of the crushing blade 8 of the roller bit 3 that contacts the crushing surface of the crushed cast iron pipe 1 and the central axis of the propulsion pipe 4 on the moving direction side 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 toward the center from the outer periphery,
The neck 12 of 10 does not crack and the fragment does not grow. Therefore, the propulsion pipe 4 does not become unrotatable, and the crushed pieces that are not collected do not stay in the inner rib 6 and are blocked.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a non-cutting cast iron pipe crushing device according to the present invention. In FIG. 1, the roller bit 3 has a joint portion 9 composed of an outlet 11 and a receptacle 10.
It shows the situation in which the cast iron pipe 1 is moving while being crushed from the outlet 11 to the receiving port 10. The cast iron pipe crushing device shown in FIG. 1 differs from the conventional cast iron pipe crushing device 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 will be described later. Is different from As shown in Figure 1,
In the cast iron pipe crushing device of the present invention, the angle θ on the moving direction formed by the extension line of the blade surface of the crushing blade 8 of each roller bit 3 contacting the pipe end surface 2 of the cast iron pipe 1 and the central axis of the propulsion pipe 4 is , 90
It is provided so that it is less than or equal to °.

By providing the roller bit 3 at such an angle, the crack of the cast iron pipe 1 unlike the conventional case does not occur. 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, is directed toward the center of the cast iron pipe, and is divided into a component force F ₂ of a plane perpendicular to the propulsion direction of the cast iron pipe. This component force F ₂ is directed toward the center of the cast iron pipe, so that the receiving port 10 of the cast iron pipe 1 receives the force from the outer periphery toward the center by the roller bit 3. Also,
Since the cast iron pipe 1 itself has a tensile rupture stress lower than the compressive rupture stress and the receiving port 10 itself has a rough shape, the receiving port 10 cracks with a low force when a force outward from the center acts. It is easy to enter, but it can withstand a large amount of force if a force acting from the outside toward the center acts. 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 portion 9 is not cracked.

[0017]

As described above, according to the present invention, the roller bit 3 causes the component force in the direction perpendicular to the axis of the cast iron pipe, which is the force received by the end surface of the cast iron pipe 1, to be directed toward the axial center of the roller. Since bit 3 is provided, cracking does not occur at the neck part of the receiving end of the joint part during old pipe renewal work due to non-open cutting, and it is possible to efficiently complete the work, thus providing industrially useful effects. Be done.

[Brief description of drawings]

FIG. 1 is a vertical sectional view for explaining an embodiment of the present invention.

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

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

FIG. 4 is a vertical cross-sectional view showing a method for mounting a conventional 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 receiving port of a joint portion by a conventional roller bit.

FIG. 7 is a vertical cross-sectional view showing a case where a cast iron pipe is crushed from an outlet of a joint portion by a conventional roller bit.

FIG. 8 is a side view showing a buried state of a cast iron pipe.

FIG. 9 is a vertical cross-sectional view for explaining the force received by the receiving port when the cast iron pipe is crushed from the receiving port of the joint portion by the conventional roller bit.

FIG. 10 is a vertical cross-sectional view for explaining a case of crushing a cast iron pipe from a joint opening by a conventional roller bit.

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

[Explanation of symbols]

 1 Cast Iron Pipe 2 End Surface of Cast Iron 3 Roller Bit 4 Propulsion Pipe 5 Guide 6 Inner Rib 7 Tip Pipe 8 Crushing Blade 9 Joint 10 Receptacle 11 Outlet 12 Neck 13 Crack 14 Sealant 15 Scraper

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshikazu Nakajima 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Masaaki Watanabe 1-2-1-2, Marunouchi, Chiyoda-ku, Tokyo Inside the Steel Pipe Co., Ltd. (72) Inventor Hiroshi Shima 5-9-1 Nishihashimoto, Sagamihara City, Kanagawa Pref., Nippon Steel Manufacturing Co., Ltd. -9-1 Nippon Steel Corporation Marine Structures Division (72) Inventor Tetsuo Kimura 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corporation (72) Inventor Minoru Kakizaki Tokyo 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corporation

Claims (1)

Claim: What is claimed is: 1. A propulsion pipe having an inner diameter larger than the outer diameter of the crushed cast iron pipe and a tip conduit integrally fixed to the tip.
Along with the circumferential direction on the inner peripheral surface of the leading conduit, rotatably mounted at a predetermined interval, provided with a crushing blade on the outer periphery, frustoconical shape, comprising a plurality of roller bits. , The tip pipe is fitted to the outside of the crushed cast iron pipe, while the propelling pipe is being rotated and moved forward, the crushed cast iron is pushed by the end surface of the crushed cast iron pipe and revolves while rotating around In a cast iron pipe crushing device for crushing a pipe, an extension line of a blade surface of a crushing blade of each of the roller bits that comes into contact with an end surface of the crushed cast iron pipe, and an angle of a moving direction formed by a central axis of the propulsion pipe. The cast iron pipe crushing device is characterized in that the angle is 90 ° or less.