JPS6355296A - Underground excavator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention) (Industrial Application Field) The present invention relates to an underground excavation device, and particularly to an underground excavation device that excavates a gravel stratum using a tricone bit.

(Prior Art) Conventionally, when burying steel pipes or the like underground, an underground excavation device has been used that buries the pipe while excavating a horizontal hole in the ground.

In this case, if the ground where the pipe is buried is in a stratum containing gravel, tricone bits are arranged in a ring at the tip of the excavation equipment, and these tricone bits are driven to revolve and dig underground. Even geological formations can be crushed and excavated.

(Problems to be Solved by the Invention) However, this type of excavation equipment has a structure that crushes all sections, so when excavating gravel, a screw auger and a mud water pumping pipe are used. , the rock must be finely pulverized to particles that can pass through the size of the screw or the diameter of the slurry pipe, and as a result, the tricone can be severely damaged or worn out, making it necessary to replace it during the work. However, with conventional tricone bits, the support member is fixed to the lead pipe of the drilling equipment, making it difficult to replace on site, and because it is installed so that it protrudes beyond the outside diameter of the lead pipe, it is difficult to complete drilling. At that time, there was a problem that the lead pipe could not be retracted without removing the tricone bit.

In addition, with conventional excavation equipment using tricone bits, if the full-section crushing method was used as described above, the tricone bit would crush gravel over the cutting surface in eight stages, so it would be difficult to excavate and crush gravel. In short, there are problems such as the size of the engine and the size of the drilling equipment.

Recently, circumferential excavation structures have been considered to overcome these drawbacks, but it is still not easy to replace the tricon pits and the cutting edges on the outer circumferential surface, and this is a problem even in the case of circumferential excavation structures. Ta.

In view of this, the present invention facilitates the attachment and detachment of tricone bits, etc., and also allows the outer tricone bit to be placed in a state that protrudes beyond the outer diameter of the buried pipe during work, and is reversed when retracting, so that the outer tricone bit can be removed easily. The purpose of this invention is to provide an underground excavation device that can be retracted inward from the outside diameter to overcome the drawbacks of the prior art.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, an axial center is provided inside the tip of the leading pipe of the casing inserted into the inside of the buried pipe in the direction of the center of the front position of the leading pipe. In an underground excavator in which a plurality of outer tricone bits with axes facing outward and a plurality of inner tricone bits with axes facing outward are arranged in an annular manner, a support part on which the outer tricone bits are rotatably mounted and its support. A support member is provided with a flat part formed through a twisted part at a predetermined angle, and the support member has one side of the flat part fixed to the inner periphery of the leading pipe at a predetermined interval. 1
and both ends in the width direction of a guide hole which is provided in an inclined state in the first annular member which moves forward of the second annular member, and in which the flat part of the support member is loosely fitted in the width direction. The base end of the flat part is rotatably supported on a bearing part provided on a second annular member located on the rear side, so that the flat part of the support member can come into contact with the stopper part of the supporting member. When one side of the part is brought into contact with one end part of the stopper part by the push-back means of the first annular member, the outer tricone bit is placed in a position where it protrudes outward beyond the outer diameter of the buried pipe. It is characterized by an underground excavation rig.

(Function) With this configuration, during excavation work, when the leading pipe rotates in the normal direction (for example, right rotation), the support member of the outer tricone bit is constantly pressurized due to the earth pressure caused by the excavated material. The outer tricone bit comes into contact with the base 1 to the collar, and as a result, the outer tricone bit protrudes outward from the outer diameter of the buried pipe, making the excavation work easier.

In addition, when the leading pipe is moved backward from the buried pipe by reverse rotation (for example, left rotation), the earth pressure applied to the outer tricone bit will be in the opposite direction, causing the tricone bit to move inward from the outer periphery of the buried pipe. Operate.

Furthermore, the push-back means acts in the direction of earth pressure during forward rotation, and in the anti-earth pressure direction during reverse rotation, so that the earth pressure pressurizes the support member in the direction away from the stopper part, reducing the earth pressure. When it runs out, the outer tricone bit is again projected outside the outer diameter of the buried pipe and returns to the excavation position.

(Example) The present invention will be described below with reference to the example shown in FIGS. 1 to 4.

The hollow type underground excavator to which the present invention is applied, as shown in its cross section in FIG. A casing 4 with a conduit 5 arranged thereon is supported by a plurality of rows 56 so as to be rotatable within the buried pipe 3 and movable in the front and rear directions.

The drive source for digging the buried pipe 3 and the casing 4 is powered by transmission of power from a gear motor 7 to a propulsion jack 8 via a chain (not shown), etc., and the operation of this propulsion jack 8 causes horizontal excavation. There is.

There is a cutting edge 9 provided around the leading pipe 5 on the front surface of the buried pipe 3, and a plurality of supporting members 1 are provided in the leading pipe 5.
0 is rotatably attached at one end, and an outer bit 11 is provided at the other end.

Note that the inner bit that is actually provided in FIG. 1 is omitted because it is a schematic diagram.

Then, the cutting edge 9, the outer bit 11 and the inner bit
The excavated earth and sand (not shown in FIG. 1) are discharged from the leading pipe 6, through the casing 4, and from an outlet (not shown).

In the figure, 12 and 14 are hydraulic hoses for cutting, and 13 is a main power cap tire cord.

The present invention relates to the front part shown in FIG. 1 above, and its basic configuration is as shown in FIGS. Inside the casing 4 and the leading pipe 5 of the casing 4, a plurality of shafts (t and 4 in the illustrated example) whose axes face the front center of the leading pipe 5
) Outer tricone bit 15.15. ...and these outer tricone bits 15.15. A plurality of (four in the illustrated example) inner tricone bits 16 located between...
16, . and a second annular member 18.19, and a first annular member located on the front side.
It is composed of a stopper part 20 provided on the annular member 18, a bearing part 21 provided on one of the second annular members located on the rear side, a push-back means 22 provided on the first annular member 18, etc. There is.

The outer and inner tricone bits 15 and 16 have a conical shape with a protrusion formed on the conical peripheral surface, and the base thereof is rotatably supported by a shaft and a bearing (not shown) in the support portion 23 of the support member 17. There is.

The support member 17 has a twisted portion 24 inclined at a predetermined angle (approximately 35 degrees in the illustrated example) from the support portion 23, and a flat portion 25 is further formed from the terminal end of the twisted portion 24. Therefore, the surface of the support portion 23 and the flat portion 25
The surface is formed at a twisted angle by the amount of the twisted portion 24.

One side 26 of this flat portion 25 is configured to come into contact with the stopper portion 20, and an end portion 27 of the flat portion 25 is configured to be engaged with the bearing portion 21.

A first annular member 18 is fixed to the front position of the inner circumference of the guide pipe 5, and a second annular member 19 is fixed to the rear position by welding or the like. Slanted square guide holes 28 are provided corresponding to the outer tricone bits 15 (four in the illustration), and when the flat portion 25 of the support member 17 is inserted, the guide holes 28 move freely in the width direction. They are designed to fit together, and one end in the width direction is formed into a stopper 20.

Further, the first annular member 18 is provided with a push-back means 22 (a spring in the third figure) such as a spring, a damper, or other similar elastic body, so that the first annular member 18 is always on the other side of the flat portion 25 of the support member 17. It is installed so as to press the

One of the second annular members has an end portion 27 of the flat portion 25.
A bearing portion 21 is provided which engages with the forked portion.

In this case, the hole 29 at the end of the flat part 25 of the support member 17 is pivoted by a pin 30 in the bearing part 21 of one of the second annular members, so that the support member 17 can swing around the pin 30. ing.

When the push-back means 22 presses the other side of the flat portion 25 and the one side 26 comes into contact with the stopper 20, the outer tricone bit 15 rotates to the outside of the outer diameter of the buried pipe 3. As shown by the solid line in FIG. 2, the excavated state is the maximum position.

A plurality of cutting edges 9 are provided on the outer periphery of the leading pipe 5 to protrude, and are set in the protruding state by bolts 318 during excavation, but when the leading pipe 5 is retracted, the bolts 31
It can be brought closer to the outer circumferential surface by loosening and folding it. In the figure, 32 is a joint flange.

Next, the effect will be explained.

First, before starting excavation, the tricone bit 15 is placed on the outside in a state where it protrudes beyond the outer diameter of the buried pipe 3, that is, the support member 1
When one side 26 of the 7 is brought into contact with the stopper 20 and the casing 4 is rotated clockwise by a drive device (not shown), the leading pipe 5 rotates together with the leading pipe 5 and the outer and inner tricone bits 15 and 16 are rotated together. revolves. The revolution of these tricone bits 15 and 16 crushes underground gravel,
The crushed gravel is taken into the casing 4, carried to the rear by a spiral rail (not shown), and discharged to the ground.

The outer and inner tricone bits 15 and 16 that are in contact with the gravel rotate about their own axes between the support portion 23 and a support portion (not shown), and the portions in contact with the gravel change, thereby crushing the gravel.

In this case, the outer tricone bit 15 is pressurized by earth pressure in a direction to protrude outward from the buried pipe 3.

If the tricone bits 15 and 16 are damaged or worn out, the casing 4 is pulled back and converted.

In order to retreat the casing 4, both the leading pipe 5 and the leading pipe 5 are rotated to the left, and the earth pressure causes the outer tricone bit 15 to
The support member 17 acts in the direction of shrinking the pin 30.
Since the tricone bit 15 can pivot along the inclined guide hole 28, the earth pressure pushes the push-back means 22 up against the push-back force, and the outer tricone bit 15 moves toward the buried pipe 3. It is shrunk inward and contained.

In this case, as soon as the earth pressure disappears, the push-back means 2
2 presses the support member 17, making it possible to quickly return to the digging position.

Therefore, when replacing the outer tricone bit 15, when the leading pipe 5 is retreated and reaches the rear end of the buried pipe 3, the pin 30 is removed from the bearing part 21 to which the support member 17 is connected, and the first annular It is sufficient to pull it out from the guide hole 28 of the member 18.

To install a new outer tricone bit 15 or a repaired tricone bit 15, the support member 17 thereof may be inserted into the guide hole 28 and then attached to the bearing portion 21 with the pin 30.

In the present invention, the twist angle of the twist portion 23 of the support member 17 is approximately 35°, but it is not necessarily limited to this, and may be selected as appropriate depending on the diameter of the leading pipe 5, the first annular member 18, etc. This is Shiuruchino.

(Effects of the Invention) As described above, the present invention includes a plurality of outer tricone bits whose axis is directed toward the center of the forward position of the leading pipe of the casing that is inserted into the buried pipe. In an underground excavation system in which a plurality of inner tricone bits with their axes facing outward are arranged in an annular manner, the outer tricone bits are rotatably attached to a support part and a twisted part at a predetermined angle from the support part. A supporting member having a flat portion formed therein is provided, and the supporting member is fixedly installed at the front and rear of the inner periphery of the leading pipe. J1 and the second annular member, the twisted part is so arranged that when it comes into contact with the stopper part provided on the first annular member, the outer tricone bit attached to the support part protrudes outward from the outer diameter of the buried pipe. Therefore, when the tricone bit wears out, by rotating the support member, the diameter of the tricone bit can be reduced to a state where the tricone bit can be accommodated in the buried pipe. While in this diameter-reduced state, the casing can be pulled back for maintenance such as replacement or repair of the tricone bit, and after inserting the support member into the guide hole of the first annular member,
Since it only needs to be supported by a bearing, there is no need to take time to attach or detach it. In addition, since the first annular member is provided with push-back means, when the tricon 1~ is under no load, it can be automatically protruded to the outside of the buried pipe, so that it is always in the excavation position. It is possible to use J5.

[Brief explanation of the drawing]

FIG. 1 is a side view of an outline of an underground excavator to which the present invention is applied, and FIG. 2 is a front view of an underground excavator according to the present invention.
FIG. 3 is a plan view taken along line A-A of FIG. 2, and FIG. 4 is a perspective view showing the relationship between the tricone bit and the supporting member, which are the main parts of the present invention. 3... Buried pipe, 4... Casing, 5... Leading pipe, 15... Outer tricone bit, 16... Inner tricone bit, 17... Supporting member, 18... First annular shape One member...Second annular member, 20...Stopper part, 21...Bearing part, 22...Pushing back means, 23...
・Support part, 24...Twisted part, 25...Flat part, 2
6...-side, 30...bin. Applicant's agent Mr. Sato Figure 2

Claims (1)

[Claims] Inside the tip of the leading pipe of the casing that is inserted into the buried pipe, there are a plurality of outer tricone bits whose axes face toward the center of the forward position of the leading pipe, and a plurality of inner tricone bits whose axes face outward. In an underground excavator with a circular arrangement of
The outer tricone bit is rotatably mounted on a support part, and the support member has a flat part formed through a twisted part at a predetermined angle from the support part, and the support member has one side of the flat part connected to the tip. Of the first and second annular members fixed at a predetermined interval on the inner periphery of the conduit, the first annular member located on the front side is provided in an inclined state and the flat part of the support member is free to move in the width direction. The base end of the flat part is rotatably attached to a bearing part provided on a second annular member located on the rear side. When one side of the flat part of the support member is brought into contact with one end of the stopper part by the push-back means of the first annular member, the outer tricone bit is pushed out of the buried pipe. An underground excavation device characterized in that it is placed in a position that protrudes outward from the diameter.