JPH0457478B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a breaking blade for an excavator that breaks old pipes, such as water pipes, buried underground without excavation.

[Prior Art] Conventionally, as described in Japanese Patent Publication No. 60-27873, the breaking blade of the above-mentioned excavator has traditionally been a conical body attached to the tip of the casing of the excavator, and a cutting blade of the same width along its generatrix. It is known to have a plurality of blades embedded in the cone, or to have a plurality of blades that can be pushed out along the generatrix from the inside of the cone using hydraulic pressure or an electric motor.

[Problems to be Solved by the Invention] However, although asbestos pipes and ductile pipes can be broken relatively easily with the breaking blade of the conventional excavator, vinyl chloride pipes do not have flexibility, ductility, etc. Because of this, once it begins to stretch, it takes too long for it to break, and a force that moves the excavator backwards acts, making it necessary to increase its propulsive force.

Therefore, the present invention aims to provide a cutting blade for an excavator that can easily break not only asbestos pipes but also vinyl chloride pipes with a small force.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a breaking blade for an excavator that breaks and spreads out old pipes buried underground, which A cone whose base is larger than the inner diameter of the old pipe, and a V-shaped cut which is installed in the cone along its diametrically opposing generatrix and extends further from the top of the cone. The blade has locking protrusions on both edges of the cutting blade that are approximately the same width as half the circumference of the aged pipe, and a locking protrusion that is installed along the opposing generatrix at a position perpendicular to the cutting blade in the cone, and has a width smaller than that of the cutting blade. It consists of a V-shaped expanding blade.

[Operation] According to the above means, the vinyl chloride pipe is stretched in the diametrical direction by the cutting blade and cut into two pieces, and then is pushed wider than the conventional diameter by the expanding blade and the cone, and the locking protrusion is locked at the cutting start end, so that the excavator is not subjected to any force that causes it to retreat due to the restoring force of the PVC pipe.

Further, after the asbestos pipe or the like is broken or cut into two in the diameter direction by the cutting blade, it is further broken into smaller pieces by the expanding blade and the cone, and is expanded to a larger diameter than the conventional pipe.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

In the figure, 1 is a cone attached to the tip of the casing 2 of the excavator, and its base has a diameter that is approximately the same as the outer diameter of the casing 2 and is larger than the inner diameter of the old pipe buried underground (old pipe). The outer diameter of the new pipe to be replaced is the same as that of the new pipe), and inside the casing 2, compressed air is supplied to move the piston forward impulsively, and the piston is also moved relatively slowly by compressed air. A propulsion device (not shown) that moves the excavator forward intermittently by moving the excavator backward is housed.

A relatively wide V-shaped cutting blade 3 is implanted on the outside of the cone 1 along its diametrically opposed generatrix lines. The tip of the cutting blade 3 extends further from the top of the cone 1, and is provided with a wire locking hole 4 for locking the wire rope of an electric winch that moves the excavator forward together with the propulsion machine. is provided. Furthermore, locking protrusions 5 are provided on both cutting edges 3a of the cutting blade 3, which have approximately the same width as the half circumference of the aged pipe. As will be described later, the locking protrusion 5 is locked to the cutting start end of the old pipe cut by the cutting blade 3, and prevents the excavator from receiving a backward force due to the restoring force of the old pipe.

Further, on the outside of the conical body 1, a V-shaped expanding blade 6 having a narrower width than the cutting blade 3 is implanted along opposing generatrix lines at a position orthogonal to the cutting blade 3. The expansion blade 6 is used to expand an old pipe made of vinyl chloride or the like which has been cut together with the cone 1 to a diameter larger than that of a conventional pipe.

Next, the action of breaking an old pipe made of vinyl chloride by the breaking blade having the above structure will be explained using FIGS. 5a to 5e.

The tip of the breaking blade is inserted into the vinyl chloride pipe 7 (see Figure 5a), and as the excavator moves forward, the vinyl chloride pipe 7 is deformed into an oval shape by the cutting blade 3 (see Figure 5a). After that, a cutting line is made inside the vinyl chloride pipe 7 by the locking protrusions 5 provided on both cutting edges 3a of the cutting blade 3 (see FIG. 5c). As the excavator moves further forward, the cutting blade 3 stretches the PVC pipe 7 to its maximum length.
The cut vinyl chloride pipe 7' is cut into two parts by the cutting edge 3a of the excavator (see Fig. 5d), and the cut vinyl chloride pipe 7' is shaped into two parts by the expanding blade 6 and the conical body 1 as the excavator moves forward. While being deformed, it is pushed wider than the conventional diameter (see Figure 5e).

When the vinyl chloride pipe is broken, the locking protrusion 5 is locked to the cutting start end, so that the excavator is not subjected to a force that causes the excavator to retreat due to the restoring force of the vinyl chloride pipe.

A new vinyl chloride pipe, ductile pipe, or the like is inserted into the cut and expanded vinyl chloride pipe 7'.

Further, after the asbestos pipe or the like is broken or cut into two in the diametrical direction by the cutting blade 3, it is further broken into smaller pieces by the expanding blade 6 and the conical body, and is expanded to a larger diameter than the conventional pipe.

[Effects of the Invention] As described above, according to the present invention, not only asbestos pipes but also vinyl chloride pipes are stretched in the diametrical direction by the cutting blade and cut into two parts, and then the expanding blade and the The diameter of the cutting blade is pushed wider by the cone, and the locking protrusion is locked to the cutting start end, so the excavator is not subjected to the force of retreating due to the restoring force of the PVC pipe, so it is larger than the conventional cutting blade. It can be broken easily and with a small amount of force.

[Brief explanation of the drawing]

Figures 1, 2, 3 and 4 are a front view, a top view, a left side view and a right side view of a breaking blade showing an embodiment of the present invention, Figures 5a, b, c, d and e are explanatory views of the action of the breaking blade, respectively. 1... Cone, 3... Cutting blade, 3a...
Blade tip, 5... Locking protrusion, 6... Expansion blade, 7
...PVC pipe.

Claims (1)

[Claims] 1. A breaking blade of an excavator that breaks and expands an old pipe buried underground, which is attached to the tip of the casing of the excavator and has a cone whose base is larger than the inner diameter of the old pipe, and a cone. A V-shaped cutting blade is installed along the opposing generatrix in the diametrical direction and extends further from the top of the cone, and a double cutting blade is provided on the cutting blade with a width that is approximately the same as half the circumference of the aged pipe. A locking protrusion and a V which are planted along opposing generatrix lines at a position perpendicular to the cutting blade in the cone body and whose width is smaller than that of the cutting blade.
An excavator cutting blade consisting of a letter-shaped expanding blade.