JPH0332637Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a cutter head for use in gravel ground of a pipe burying device for inserting and burying water and sewage water pipes etc. by drilling horizontal holes in the ground.

[Prior art and its problems]

The gravel ground cutter head of the pipe burying equipment that has been used in the past has a structure in which cone bits are installed in a ring shape on a circular plate that has holes for the excavated soil to pass through.
It was installed inside the cutting tube.

However, although the above-mentioned cutter head can crush the gravel taken into the cutter tube, it cannot crush the gravel that is at the opening of the cutter tube because it cannot be taken into the cutter head. As a result, the direction of propulsion was distorted and it became impossible to proceed.

In addition, since the gravel is crushed within the cutting tube, vibration is imparted to the cutting tube, which has an adverse effect on the cylinder, seal, etc. between the cutting tube and the leading tube.

[Purpose of invention]

In view of this, the present invention was devised for the purpose of providing a cutter head for a gravel layer that also crushes gravel around the circumference of the cutter tube.

[Summary of the idea]

In order to achieve the above object, the present invention excavates gravel near the opening of the cutter pipe in the cutter head of a pipe burying device, forms a core casing to take the gravel into the cutter head, and collects the gravel taken into the cutter head. It consists of a cutter head with corn bits placed inside the core casing to crush the core until it becomes a sufficient size.

[Example of idea]

Hereinafter, the present invention will be explained with reference to the embodiments shown in FIGS. 1 to 4.

The pipe burying device to which the present invention is applied is provided with a guide pipe 1 at the tip of a buried pipe (not shown), a cutting pipe 2 at the tip of the guide pipe 1, and a screw 3 inserted into the casing 4 into the buried pipe. The screw conveyor 5 is equipped with a screw conveyor 5, and a cutter head 6 is provided at the tip of the screw 3, and the screw 3 is rotatably driven to excavate the ground at the tip of the pipe while pressing and propelling the pipe from behind. There is.

In the cutter head of the present invention, a cylindrical core casing 7 is inserted into the cutting edge tube 2, the outer edge of the tip thereof has approximately the same diameter as the outer edge of the cutting edge tube 2, and a plurality of core bits 10 are provided on the edge of the tip. , 10... are planted. The core casing 7 has a shape that narrows toward the rear, and is connected to the tip of the screw 3 via a mounting plate 11 fixed to the rear end. A passage hole 9 is opened.

Inside the core casing 7, substantially cone-shaped cone bits 8, 8, . . . are arranged at 120° intervals, each having a large number of bits planted on the outer peripheral surface. Note that the cone bits 8, 8, . . . are attached so as to be rotatable.

Further, the shape of the core casing 7 may have the function of collecting gravel to the installation location of the cone bit 8.
A large number of holes may be provided so that only the gravel can be sent to the location where the cone bit 8 is installed, and the earth and sand can be passed between the core casing 7 and the cutting edge tube 2.

3 and 4 show a second embodiment of the present invention, and parts common to the previous embodiment will be described using the same reference numerals.

The core casing 7 of the second embodiment is configured to extend to the front part of the casing 4, and the blades of the tip screw 6 and the inner surface of the core casing 7 are joined. Further, on the outer periphery of the front part of the core casing 7, a support member 14 is provided to reduce friction with the cutting edge tube 2.
is provided. A gravel guide member 13 is provided on the inner surface of the core casing 7 in front of the cone bit 8, and three protrusions are provided at a position facing the cone bit 8.

The cone bit 8 is fixed to a bit holder 16 provided at the tip of the screw 3. The cutter head 6 is interlocked with the screw 3 and can freely slide back and forth.

Next, the effect will be explained.

When the screw 3 is rotated by a drive source (not shown), the cutter head 6 rotates, and the gravel on the front surface of the cutter tube 2 is removed from the core bit 1.
Excavate by 0. As a result of this excavation, gravel flows into the core casing 7 and is collected around the cone bits 8, and the rotation of each cone bit crushes the gravel, and those that are smaller than a predetermined size are crushed into the passage hole 9.
The screws are discharged into the casing 3, and as the screws 3 rotate, they are discharged rearward through the screw conveyor 5 and out of the apparatus. The cutter head 6 of the second embodiment excavates with the tip of the cutter head 6 retracted from the tip of the cutter tube 2, and when the cutter tube 2 collides with gravel, the cutter head 6 is pulled back from the tip of the cutter tube 2. The gravel is excavated by moving it forward, and the gravel that is taken in is transferred to the guide member 13.
are collected around the cone bit 8 and crushed by the rotation of the cone bit 8 until they are large enough to pass between the cone bit 8 and the protrusion 15,
The liquid is discharged from the apparatus in the same way as in the first embodiment.

At this time, since the gravel is collected at the center of rotation of the cutter head 6 and then distributed, the torque required for crushing can be reduced.

[Effect of idea]

As explained above, according to the present invention, the gravel layer ground is excavated and the gravel is collected around the cone bit 8 and crushed, so even if gravel hits the opening of the cutting pipe 2, excavation is possible. , there is almost no vibration transmitted to the cutting edge tube 2.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the front side of a pipe burying device equipped with a cutter head according to the present invention, Fig. 2 is a front view of Fig. 1, and Fig. 3 is a sectional side view of the second embodiment. 4 is a front view of FIG. 3. 1...Leading pipe, 2...Blade pipe, 3...Screw, 4...Casing, 5...Screw conveyor, 6...Cut head, 7...Core casing, 8...Cone bit, 9...Passing hole, 10
... core bit, 11 ... mounting plate, 12 ... universal joint, 13 ... guide member, 14 ... support member,
15... protrusion, 16... bit holder.

Claims (1)

[Scope of utility model registration request] A guide pipe is provided at the tip of the buried pipe, a cutting pipe is provided at the tip of the guide pipe, a casing is installed inside the buried pipe, a screw is inserted into the casing to form a screw conveyor, and a screw conveyor is formed by inserting a screw into the casing. In this pipe burying device, a cutter head is provided at the pipe head, and the cutter head is rotatably driven to excavate the ground at the tip of the pipe while pressing and propelling the pipe from behind. A core casing is inserted into the cutting edge pipe, and the rear end of the core casing is connected to the tip of the screw, and a plurality of cone bits are arranged inside the core casing so as to be rotatable on their own axis. Cut head for use.