JPH064149Y2 - A device that replaces an existing main with a new main - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a device for replacing an old pipe buried in the ground, such as a water pipe or a gas pipe, with a new pipe, especially a new pipe without digging up the ground surface. The present invention relates to a device for replacing the.

[Prior Art] When old pipes, especially cast iron pipes, become difficult to function due to aging after burial, or when there is a lack of capacity due to increased demand and it is necessary to replace with new pipes, excavate the entire surface It is desirable to replace the old and new main pipes without digging up the ground surface, because the method of digging out the old pipes is costly, labor intensive, and hinders traffic on the ground.

The so-called pipe-inner pipe method, in which the new pipe is inserted into the old pipe in the ground, corresponds to this, but naturally the inner diameter of the new pipe becomes smaller than the inner diameter of the old pipe, resulting in a decline in the transportation capacity of gas and water.

The prior art, which is the basis of the present application, is an invention for solving this problem as shown in FIGS. 2 and 3, "a method and apparatus for replacing an existing main with a new main" (Japanese Patent Publication No. 60-27873). In detail.

In FIG. 2, an excavator 1a having a fuselage outer diameter larger than the outer diameter of the old pipe 2a has attached at its rear end a new pipe 8 to be replaced or a liner 9 serving as a protective sleeve for the new pipe.

Further, in FIG. 3, the excavator 1b incorporates an air hammer 10 for driving the excavation, and an air hose 11 for operating the air hammer is inserted into a new pipe and connected to a rear pressure source. On the other hand, a cable that goes through the old pipe and connects to the winch in front is attached to the tip of the excavator.

The excavator is shocked to move forward by the driving force sent from the rear, while it receives the pulling force of the winch from the front and tries to move forward by hitting and breaking the old pipe by receiving the front and rear driving force.

At this time, the maximum outer diameter of the body of the excavator was selected so that it was larger than the outer diameter of the old pipe, so the crushed old pipe was expanded to the outer periphery, and a cavity portion larger than the outer diameter of the new pipe or liner that followed. It is possible to smoothly replace the old and new pipes by utilizing the gap corresponding to the outer diameter difference.

FIG. 2 shows a fixed cutting blade 3a provided around the body having the large outer diameter, and FIG. 3 shows another embodiment in which a cutting blade 3a that can be activated at the tip of an excavator is provided to further enhance the crushing effect. , And bulges like a bullet from the tip of the excavator to the body, is locked on the inner surface of the old pipe in the middle and is pushed up diagonally to be crushed.

[Problems to be Solved by the Invention] Although the conventional technology described above is a rational and excellent technology, there are still some problems to be improved.

As one of them, the old pipe is shock-ruptured at the front part of the excavator, so if the old pipe is a very brittle material such as a ceramic pipe or a cast iron pipe, the old pipe after contact with the front part of the excavator The old pipe is broken not only at the end but also far in front of the excavator. The broken pipe piece and the sediment above the old pipe fall and accumulate in the old pipe in front of the excavator, so the excavator must move over the deposits and move in the old pipe. Gradually changes its course upwards and stops moving along the old pipe. The state is divided into three stages from the initial stage to the stage where the old pipe cannot be completely ruptured, which are shown in FIGS. 4A, 4B and 4C.

As a result of this, 1. The excavator moves upward, so it has a great impact on the road surface.

(Ground cracks, pavement surface damage, road surface upheavals, etc.) 2. If there are other pipelines that are orthogonal or parallel to the old pipe, the excavator travels upward, so the impact on those other pipelines will increase. .

(The risk of damage to the pipes of other pipelines and leakage of joints increases.) 3. Since it travels in the soil, the resistance increases compared to when moving along the old pipe, and the workability is impaired.

4. Sediment above the pipe falls into the old pipe, disturbing the surrounding ground. (The ground becomes unstable.) 5. If the excavator moves excessively above Fig. 4C,
The winch cable was caught between the old pipe and the excavator,
The cable is cut. When the cable is cut, the guide from the front disappears, the excavator moves further upward, and finally there is a problem that the construction becomes impossible.

However, there is a conventional technique in which the length of the excavator is long and the straight cylinder portion ahead of the cutting blade precedes, so that the old pipe fragments and the earth and sand that are broken in the forward direction of the course are prevented from collapsing.

That is, examples thereof include JP-A-62-125197 shown in FIG. 5 and JP-A-59-173492 shown in FIG. In the technique of FIG. 5, the casing (excavator) 1
Except for the expansion adapter 20 that connects the new pipe 8c to the rear end of the pipe c, the storage portion of the pipe breaking blade (cutting blade) 3c that breaks the old pipe 2c is also formed of a single straight cylinder. That is, as in the present application, there is no distinction between the head portion of the head and the body portion of the enlarged outer diameter, and the pipe breaking blade 3c moves out of the cylinder along the conical surface of the enlarged wedge 21 from the middle of the right cylinder. The pipe piece that has been broken before the pipe breaking blade 3C cannot fall.

In the prior art of FIG. 6, the head 4d at the tip is the crushing blade 3
It is a structure that can be separated from the body part 1d of the excavator with d,
Since the male screw 30 protruding from the head portion 4d is screwed together with the female screw 31 provided at the shaft center of the body portion 1d to be integrally assembled, the same effect as the previous example can be expected.

However, old pipe lines buried in the ground are not always straight lines and are usually bent everywhere, so as shown in Fig. 5 and Fig. 6, the excavator is fixed with a rigid body over the entire length. At the time of construction, the course cannot be changed in conformity with this curved road, which may cause a serious obstacle in the long non-excavation method.

The 7th attempt to guide the propulsion unit along the curved conduit
There is also Japanese Unexamined Patent Publication No. 61-88084 shown in the figure, but the construction is such that the excavating blade 3e rising obliquely upward is retractably stored in the truncated cone-shaped excavator body 1e. A spacer ball 40 is connected to the front of the body via a connecting portion 41 and a connecting fitting 42 each having a smaller diameter than that. In the rear of the body, the ceramics 4 is passed through a connecting portion 43 having a smaller diameter than this.
4 is set so as to rotate a circular truncated cone 45 and crush the old pipe that has been crushed or cracked by the excavating blade 3e and the earth and sand around it.

The spacer ball 40 is fitted so that its outer diameter is substantially equal to the inner diameter of the old pipe, and the wire rope 12e inserted through the old pipe is inserted.
Since it is towed from the front via the pipe, even if the old pipe bends in the middle, it will advance along this pipe and guide the subsequent excavator along the curve via the connecting fitting 42. .

However, in this prior art, as shown in FIG. 8, there is a connecting portion 42 having a diameter smaller than that of the connecting metal fitting 42 and the body portion 1e behind the preceding spacer ball, and a hollow portion is formed between the inner surface of the old pipe. There is also a hollow portion between the small-diameter connecting portion 43 and the crushing site behind the digging blade 3e, so that the pipe fragments and earth and sand of the old pipe crushed by the digging blade collapse before and after the body 1e. , The entire device with its path blocked rides on this fallen object and makes the path go wrong. That is, it is expected that the same failures as those pointed out in FIGS. 4A, 4B, and 4C will be caused more seriously.

In order to solve the above-mentioned problems, the present invention can smoothly go straight without breaking the broken old pipe and the earth and sand in the front old pipe of the excavator and hindering the path of the excavator.
It is an object of the present invention to provide an excavator that can move forward in conformity with a curved road without hitting the curved road and hindering the forward movement when the old pipeline is bent.

[Means for Solving Problems] An apparatus for replacing an old pipe with a new pipe according to the present invention has an outer diameter d slightly smaller than an inner diameter R of an old pipe in a tip direction of a body portion having a large outer diameter of an excavator. The above problem was solved by attaching a cylindrical head having a length L that is at least twice the outer diameter d so as to be attachable / detachable via a separation prevention flexible joint.

[Operation and Embodiment] The operation of the present invention will be described with reference to FIG.

When the outer diameter of the body which is larger than the inner diameter of the old pipe 2 of the excavator 1 of FIG. 1 is D, the portion of D enters the inner surface side of the old pipe and pushes up diagonally to crush the old pipe 2. In this embodiment, the cutting blade 3 is attached and takes charge of the crushing action.

A cylindrical head 4 fitted into the old pipe is connected to the tip of the crushing portion via a separation preventing flexible joint 6.

The outer diameter d of the head portion 4 does not have a great difference from the inner diameter of the old pipe, and the head portion 4 enters the inner diameter to the extent of being fit. The length L of the head is set in consideration of the material of the old pipe, the diameter, the pipe thickness, the impact force of the excavator, etc., and if it is replaced with the most suitable one according to the condition of the old pipe at the construction site, 1 With a single excavator, it is possible to proceed with the renewal method suitable for various sites.

The length L of the head is set to be at least twice the outer diameter d because the front and rear of the body are pressed by the pipe walls in opposite directions when they are fitted in the bent old pipe, and the following excavator is used. Was limited in the sense that it was long enough to forcibly correct the course of the pipe of the old pipe, but in practice, as shown in FIG.
About 3 times is sufficient.

Due to this structure, there is a fall prevention mechanism that fits into the inner diameter of the old pipe, not only at the rear end of the old pipe being tapped at the tip of the excavator, but also when the old pipe is broken far in front of the excavator. Therefore, the pipe piece of the old pipe and the earth and sand above the old pipe do not fall into the old pipe. Therefore, the excavator does not get over the falling pipe pieces and the earth and sand, so that the excavator does not move upward and certainly has a unique effect of advancing along the old pipe.

Further, even when the old pipeline to be updated is bent, the head easily fits into the pipeline and the head is shaken so as to accurately guide the following propulsion unit.

That is, as shown in FIG. 10, the head 4 changes its direction independently along the curve of the old pipe by the action of the flexible joint when it approaches the pipe line of the bent old pipe as shown in FIG. Since the head 4 is going to move forward as it is, the head 4 receives pressing forces at the front end A and the rear end B of the body which are vertically opposed to each other, and acts on the joint surface with the excavator to forcibly correct its posture to the same axis as the head. To do. The larger the length L, the stronger the force of leverage by the principle of leverage, but if it is too long, the entire length cannot be inserted into the bent old pipe having a large curvature, and as a result, it is sufficient that the outer diameter d is 2 to 3 times. is there.

Looking at this operation in the prior art of FIG. 7 configured for almost the same purpose, the states shown in FIGS. 9A and 9B are assumed. FIG. A shows a state in which the spacer ball 40 is approaching the bent old pipe 2e, and the action of changing the direction of the following truncated cone-shaped body portion 1e is required here. However, in reality, as shown in FIG. B, the spacer ball is located between the pulling force from the front and the load on the rear, and the contact point P with the old pipe is present.
There is a big difference in that a forced force for adapting the posture of the body portion 1e to the bent old pipe line is not exerted due to a slip on the connecting contact surface of the connecting fitting 42.

[Effect of the Invention] Since the excavator surely moves along the old pipe and does not move upward, the influence on the road surface and other pipes existing above the old pipe is extremely small. Since the earth and sand do not fall above, the surrounding ground is not disturbed and problems such as road surface depressions and cracks do not occur.

Also, since the resistance does not increase when the excavator progresses, construction performance (eg, excavator speed) is not impaired, and the winch cable is not cut, so construction cannot be performed during construction. The fear is gone.

Furthermore, the center of the existing pipe and the center of the excavator are maintained so that the cutting blade installed at the tip of the excavator taps the rear end of the old pipe evenly around the entire circumference, making it easy to break the old pipe. .

If the tip of the excavator is a taper type and the cutting blade is arranged in the tapered portion as in the past, it is also expected that the cutting blade will hit one side due to the inclination of the excavator and the old pipe will not be completely broken. It

Furthermore, it is possible to separate the entire length of the excavator, which will become longer and longer, through the joint structure at the head and to connect it in the start pit, so that the effect that the size of the start pit can be made smaller than before will also be derived. .

In addition, the advantage of the joint structure is that if cylindrical heads with different outer diameters are prepared, even if the pipe diameter of the old pipe is different, the fitting that matches the pipe diameter can be performed, so that the fall of earth and sand, etc. can be prevented. There are also side effects that contribute to the achievement of the main objective.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, FIGS. 2 and 3 are front views showing another embodiment of the prior art, FIG. 4A,
B and C are front views for explaining problems in the implementation of the prior art,
5 to 7 are front views showing different embodiments of the prior art, and FIGS. 8 and 9A and B are front views showing the problems of the prior art shown in FIG. 7, and FIG. The figure is a front view showing the operation of the present invention. 1 ... Excavator, 2 ... Old pipe, 4 ... Head 6 ... Detachment prevention flexible joint D ... Maximum outer diameter of excavator, d ... Parallel outer diameter L ... Parallel parallel length It

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yusuke Shibata 1-12-19 Kitahori, Nishi-ku, Osaka-shi, Osaka Prefecture Kurimoto Iron Works Co., Ltd. (72) Kenji Kondo 1-12 Kitahori, Nishi-ku, Osaka-shi, Osaka No. 19 Kurimoto Iron Works Co., Ltd. (56) References JP-A-62-125197 (JP, A) JP-A-61-88084 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A new main pipe or a protective sleeve for a new main pipe at the rear end of an excavator having a body portion having an outer diameter larger than that of an existing main pipe (hereinafter referred to as "old pipe") buried in the ground. A liner (hereinafter referred to as "new pipe") is attached, both of them move forward and the tip of the excavator enters into the old pipe, and the body with the large outer diameter crushes the old pipe to move forward and spread the gap. In a device for replacing an old pipe with a new pipe, the excavator has an outer diameter d slightly smaller than the inner diameter R of the old pipe in the direction of the tip of the large outer diameter body portion, and the length L is at least twice the outer diameter d. A device for replacing an old pipe with a new pipe, characterized in that a cylindrical head is detachably mounted via a detachable flexible joint.