JPH0235118B2 - SUIHEICHOKYORISAKUSHINKOHONIOKERUKUTSUSAKUHETSUDO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an excavation head for long-distance excavation methods.

2. Description of the Related Art Trenchless burying methods have been known for burying relatively small-diameter pipes such as gas pipes and water pipes on roads with heavy traffic or in urban areas. This construction method generally involves laying a pilot pipe from a starting shaft to a destination shaft, and then sequentially burying the main pipe along the pilot pipe while enlarging the hole with a drilling head.

Various types of excavation heads have heretofore been known, and a new excavation head was previously proposed by the present inventor in Japanese Patent Application No. 56-106290. This drilling head is connected to the tip of a pilot pipe that has penetrated to the arrival shaft, and is designed to drill a hole while being drawn toward the starting shaft via the pilot pipe. In addition to having bits,
A discharged soil intake port is formed near the bit, and is rotatably connected to a subsequent buried pipe. The soil excavated by the bit is taken into the head through the inlet and sent out to the outside.

However, after further investigation, it was found that such a drilling head also had one problem. In other words, the ground contains gravel of various sizes, and some of this gets stuck in the soil intake of the head, hindering subsequent soil intake, and as a result, excavation cannot be carried out. The problem is that they run out or their efficiency declines.

The present invention has been devised in view of these problems, and it is an object of the present invention to provide an excavation head that can appropriately prevent clogging of the soil intake port due to gravel or the like.

Therefore, in the present invention, a hood-shaped bit holding member that covers the head body is provided on the front surface of the head body so as to be movable in the longitudinal direction of the head body through a rod on the front surface of the head body, and a bit holding member and a hood-shaped bit holding member that covers the head body are provided so as to be movable in the longitudinal direction of the head body. In addition to providing soil intake ports, protrusions are also provided on the front of the head body and on the back of the bit holding member to face these soil intake ports. In this case, by retracting the bit holding member toward the head body, each protruding member is pushed into the opposing earth removal intake port, and the trapped gravel is pushed out.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 is an excavation head according to the present invention, 2 is a buried pipe carried by the excavation head, and 1 is a main body of the head.

A guide cylinder 6 having a mounting hole 2 is provided in the center of the front surface of the head body 1, and a rod 3 to which a pilot tube is to be connected to the mounting hole 2 can move back and forth in the axial direction of the head body. It is inserted. In this embodiment, the rod 3 is configured in the shape of a spline shaft, and is fitted into the mounting hole 2 to prevent rotation in the circumferential direction.

A step part 32 for a stopper is formed on the front end side of the rod 3, and a step part 33 for a stopper is also formed on the rear end side by a ring 28, and these steps are connected to the front edge of the mounting hole 2 and the rear end. The forward and backward stroke of the rod 3 is determined by contacting the end edge.

A hood-shaped bit holding member 7 is attached to the rod 3 and has a shape that substantially corresponds to the front end of the head body. The bit holding member 7 has a tapered front surface and a short tubular skirt portion 71 at the rear portion, and the inner circumferential surface of the skirt portion 71 slides on the circumferential surface of the head body 1 in the longitudinal direction of the head body. Possibly abutting. The circumferential surface on the tip side of the head body 1 that the skirt portion 71 comes into contact with is configured to have a smaller diameter than the main body portion in order to absorb the thickness of the skirt portion 71.

Several drilling bits 8 are provided in the radial direction on the front surface of the bit holding member 7, and in the vicinity of each of them,
A slit-shaped soil intake port 9a for taking soil into the inside of the bit holding member 7 is also provided in the radial direction. In addition, a slit-shaped soil intake port 9b facing in the radial direction is also provided on the front surface of the head main body 1.
is provided. Then, the discharged soil intake port 9a of the bit holding member and the discharged soil intake port 9b of the head body 1.
are provided with their positions shifted in the circumferential direction.

Projecting members 10a and 10b are provided on the front surface of the head main body 1 and the back surface of the bit holding member 7 so as to face the discharging soil intake port of the bit holding member 7 and the discharging soil intake port of the head main body 1, respectively. By retracting the bit holding member 7 toward the head main body, each protrusion member 10a, 10b can be pushed into the opposing soil intake port 9b, 9a. Projection members 10a, 10b
In this embodiment, it is constituted by a plate-shaped body.

In addition, to explain other configurations, a pipe body 11 is connected to the rear part of the head body 1 by a rotary joint 13.
are connected. That is, at the rear of the head body 1, there is a shaft body 12 having a hollow portion 121 with both ends open.
The head body and the tube body 11 are rotatably connected to each other by supporting the shaft body 12 within the tube body 11 by a bearing constituting a rotary joint.

A hollow portion 31 for water flow is formed in the rod 3 along its axial direction, and the hollow portion 31 is closed at the end on the pilot pipe connection side in the longitudinal direction.
and is open at the opposite end. On the other hand, from the direction of the tube body 11, the water supply pipe 4 fixed to the tube body 11 passes through the hollow part 121 of the shaft body 12 to the head body 1.
A small diameter tube portion 41 guided inward and attached to the tip thereof is fitted into the open hollow portion 31 of the rod 3 so as to be rotatable in the circumferential direction. A bearing 25 (for example, a sealed bearing) and a seal 26 are provided on the inner periphery of the hollow part.
is provided. The water supply pipe 4 is closed at its end on the pipe body 11 side and has a water supply port 42 at the end, and the pipe 5 is connected to this water supply port 42 so that water can be supplied thereto. There is. In rod 3,
Water injection holes 17 and 18 are provided extending from the hollow portion 31 near the front of the bit holding member 7 and near the front of the head body, respectively.

Further, a soil discharge pipe 14 is led from inside the head body 1 through the inside of the water supply pipe 4 in the direction of the pipe body 11,
A pump formed by water injected from the water injection pipe 15 sucks the waste soil inside the head body 1 backward.

Further, in this embodiment, a valve 16 for adjusting the amount of soil taken in is provided inside the soil intake port 9b provided on the front surface of the head main body 1. This valve 1
6. When excavating soft ground, etc., taking in too much surrounding soil into the head body 1 may cause the soil wall to collapse, so the amount of soil taken in should be adjusted appropriately. It is an object. That is, a ring-shaped holder 21 is fitted onto the outside of the guide cylinder 6 so as to be able to slide in the axial direction of the guide cylinder, and arms 22 extend from the holder 21 in the direction of each of the soil removal ports 9b. A valve 16 for closing each discharged soil intake port 9b is attached to the tip. Further, a spring 24 whose one end is locked to a stopper 23 is mounted on the guide tube 6, and this spring 24 presses the holder 21 toward the tip of the rod 3. In this pressed state, the holder 21 is locked to a step 61 provided on the outer periphery of the guide cylinder 6, and each valve 16 closes each discharged soil intake port 9b. Each valve 16 is
The soil is pushed against the elastic force of the spring 24 by the earth pressure applied to the front surface, and the soil is taken into the head from the soil intake port 9b.

In addition, in other drawings, 19 is a female thread provided at the tip of the rod 3 for connecting the pilot tube, 27 is a bearing member that rotatably supports the water supply tube 4 within the shaft 12, and 28 is a guide tube. 6
This is the frame that holds the rear end. Further, a buried pipe is connected to the rear end of the pipe body 11 by welding or the like.

The operation of the excavation head as described above will be explained.

The drilling head of the present invention is attached to the tip of a pilot pipe penetrating from the starting shaft A to the reaching shaft B, as shown in FIG. 4, and is pulled toward the starting shaft A while drilling to expand the hole. That is, the excavation head is pulled while only the head body 1 is rotated by the pilot pipe which retreats in the direction of the starting shaft while being rotated by the driving force of the drive device 29, and the excavation head is pulled into the ground by the excavation bit 8 on the front side. Drill the hole. The pipe body 11 entrains the buried pipe to its rear part and follows the head body 1 in a non-rotating state. The buried pipe led to the excavation head is added to the destination shaft B side as the head advances, and the burial is completed when the excavation head reaches the starting shaft A side. In addition, in such a pipe burying process, the rear end of the buried pipe RO may be pressed by a pressing device on the reaching shaft B side to supplement the propulsive force of the buried pipe RO, and the above-mentioned pressing device may also be used. Instead, excavation is performed so that a gap is created between the buried pipe and the earth wall of the excavation hole, and an anti-friction agent is injected into this gap to reduce the peripheral surface resistance with the earth wall. It can be done.

The soil produced by excavation is first taken into the inner space 20 through the soil intake port 9a of the bit holding member 7, and then guided into the space 20 inside the head body 1 through the soil intake port 9b on the front surface of the head body 1. space 20
The waste soil inside is discharged to the rear by the discharge pipe 14 and pump.

In the process of such excavation, if the soil intake port 9
If gravel or the like gets stuck in a and 9b, clogging them, stop the excavation once and push the pilot pipe back toward the excavation head on the starting shaft side. As a result, the rod 3 slides through the mounting hole 2 into the head main body, and along with this, each protruding member 10a, 10
b is pushed into the opposing soil intake ports 9b and 9a to push out the trapped gravel to the outside of the bit holding member or into the head main body. Thereafter, when the pilot tube is pulled, the rod 3 slides back to its original position, and in this state excavation is resumed.

In the above embodiment, the present invention is applied to a device in which water is supplied and soil is discharged through a buried pipe. It goes without saying that the present invention can be applied to various types of devices, such as devices configured to perform discharge.

According to the present invention as described above, even if gravel or the like gets stuck in the soil intake port of the excavation head and becomes clogged, it can be easily removed, so that the excavation work can be carried out smoothly. There is an effect.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a longitudinal sectional view, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is a cross-sectional view of the head body. The front view and FIG. 4 are explanatory diagrams showing the excavation situation by the excavation head of the present invention. In the figure, 1 is the head body, 2 is the mounting hole, and 3 is the head body.
is a rod, 7 is a bit holding member, 8 is a bit, 9
10a and 10b are projection members, and 71 is a skirt member.

Claims (1)

[Claims] 1. A mounting hole is provided in the center of the front surface of the head body, a rod to which a pilot pipe is to be connected is mounted in the mounting hole so as to be movable in the axial direction of the head body, and a soil removal inlet is provided on the front surface of the head body around the mounting hole. The rod is provided with a hood-shaped bit holding member that covers the front surface of the head body and whose rear end inner circumferential surface contacts the circumferential surface of the head body so as to be able to slide in the longitudinal direction of the head body. In addition to providing an inlet, a bit is provided on the front surface, and protruding members are provided on the front surface of the head main body and the back surface of the bit holding member so as to face the discharging soil intake port of the bit holding member and the discharging soil intake port of the head body, respectively. Excavation head for horizontal long-distance excavation method.