JPH0357279B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to underground excavation equipment, and in particular, to a cone-shaped bit (hereinafter referred to as a cone bit) having a large number of convex portions on its circumferential surface. It relates to underground drilling equipment used for excavating geological formations.

[Prior art and its problems]

In order to bury steel pipes etc. underground, an underground excavation device is used that excavates a horizontal hole underground and buries the pipe.

If the ground where the pipe is buried is a stratum containing gravel,
Cone bits are arranged in a ring at the tip of the drilling equipment,
By revolving these cone bits and digging underground, even gravel layers can be crushed and excavated.

However, in this type of excavation equipment, when excavating gravel strata, the cone bits are severely damaged and worn out, making it necessary to replace them during the work.

Conventional cone bits have had the problem that their support members are fixed to the leading pipe of the excavation equipment, making it difficult to replace them at the excavation site.

Furthermore, conventional drilling equipment using corn bits has a structure in which the corn bit crushes gravel over the entire surface of the excavation, resulting in problems such as the large amount of power required for excavation and gravel crushing, and the need to increase the size of the drilling equipment. .

[Purpose of the invention]

The present invention has been made with the aim of improving the above-mentioned problems of the prior art, and is an underground drilling device that can easily attach and detach cone bits and at the same time can drill holes with a reduced excavation area. is to provide.

[Summary of the invention]

In order to achieve the above object, the present invention includes a plurality of first cone bits whose axes are directed to the center of the forward position of the leading pipe inside the tip of the leading pipe of a casing that can be inserted into the inside of the buried pipe; A plurality of second cone bits facing outward are arranged in an annular shape, and a support member on which the first and second cone bits are rotatably mounted is inserted through an annular member fixed to the inner periphery of the leading pipe. The support member is inserted into the hole as tightly as possible, and the inner end of the supporting member is brought into contact with the inner peripheral surface of an annular cam member which is rotatable by a driving means such as a fluid cylinder along the inner periphery of the leading pipe. The present invention is characterized in that by rotating the cam member, the cam portion of the cam member presses the inner end of the support member toward the center of the guide tube and fixes it.

[Embodiments of the invention]

The present invention will be described below with reference to embodiments shown in the drawings.

As shown in FIG. 1 and FIG. 2, a vertical perspective view of the characteristic parts of the present invention and a side view of the longitudinal section, a leading pipe 3 at the tip of a casing 2 inserted into a pipe 1 to be buried underground. A plurality of (four in the illustrated example) first cone bits 4, 4... and a plurality (four in the illustrated example) of the first cone bits 4, 4... located between each of the first cone bits 4, 4... Second cone bits 5, 5, . . . are arranged in a respective arrangement.

The first and second cone bits 4 and 5 have a conical shape with a protrusion formed on the conical peripheral surface, and their bases are connected to the shafts 8 and 9 at the tips of the support members 6 and 7 and the bearings 10 and 11. It is rotatably mounted.
The support member 6 of the first cone bit 4 is longer than the support member 7 of the second cone bit 5, and is formed thinner toward the end.

Two annular members 12 and 13 are fixed to the inner periphery of the leading pipe 3 at intervals by welding or the like, and an annular cam member 1 is disposed immediately inside the inner annular member 13.
4 is rotatably provided along the inner peripheral surface of the leading tube 3. The tips of piston rods 15A, 15A of hydraulic cylinders 15, 15 whose bases are pivotally supported on the leading pipe 3 side are connected to the cam member 14, and the cam member 14 is moved to a predetermined position by the operation of the hydraulic cylinders 15, 15. It is designed to rotate at an angle.

The annular members 12 and 13 have square holes 16 and 1 through which the support member 6 of the first cone bit 4 can be inserted.
7, and square holes 18 and 19 into which the support member 7 of the second cone bit 5 can be inserted are formed correspondingly.

The first cone bit 4 has its tip facing toward the center of the leading tube 3, and its circumferential surface positioned forward is approximately parallel to the front end surface of the leading tube 3 and protrudes from the tip of the leading tube 3. It is placed on the outer periphery of the base of the cone bit 4 at a position slightly protruding from the outer diameter of the buried pipe 1. At this time, the inner end of the support member 6 is placed on the cam surface 14A of the cam member 14, and the cam member 14
When the inner end of the support member 6 is rotated by the hydraulic cylinders 15, 15 and the inner end of the support member 6 is pushed up by the convex cam portion 14B, the support member 6 is pressed against the inner surface of the square holes 16, 17 of the annular members 12, 13. It is designed to be fixed.

The second cone bit 5 has its tip facing outward, is positioned slightly retracted from the radius of the leading tube 3, and its peripheral surface positioned forward is approximately parallel to the front end surface of the leading tube 3. The cone bit 5 is placed at a position protruding from the tip of the conduit 3, and the base of the cone bit 5 is placed on an imaginary circle passing through the circumferential surface located inside the first cone bit 4. In the illustrated embodiment, the inner end of the support member 7 of the second cone bit 5 is located within the square hole 19 of the inner annular member 13, and a retaining pin is attached to the support member 7 at the inner position of the outer annular member 12. 20 is hammered to prevent it from coming off from the annular member 12. However, this support member 7 is also
Similarly to the support member 6 of the cone bit 4, it may be fixed by coming into contact with the cam surface 14A of the cam member 14. Further, the driving means for rotating the cam member 14 includes hydraulic cylinders 15, 15,
It may also be a combination of a hydraulic motor, an electric motor, and gears.

A spiral blade 21 is formed on the inner circumferential surface of the casing 2, and the earth and sand and crushed gravel taken in from the tip of the leading pipe 3 are sent rearward and discharged to the ground. In addition, flanges 2A and 3A on the joint surfaces of the casing 2 and the leading pipe 3 are connected to bolts 22 and 22.
...is concluded and connected. In the figure 23
is a group of rollers interposed between the leading pipe 3 and the buried pipe 1. When a hydraulic cylinder or a hydraulic motor is used, the hydraulic piping 24 is placed between the outer peripheral surfaces of the leading pipe 3 and the casing 2 and the inner peripheral surface of the buried pipe 1. When an electric motor is used, power supply lines can be wired in the same manner, and both are led out from the rear end of the casing 2 and can be remotely operated in a pit (not shown).

Next, the operation of the above embodiment will be explained.

During underground excavation, when the casing 2 is rotated by a drive device (not shown) in the state shown in FIG. do.

The revolution of these cone bits 4 and 5 crushes the gravel in the ground, and the crushed gravel is taken into the casing 2 from the inside of the leading pipe 3 as the casing 2 is pushed forward, and the spiral blades 21 on the inner circumference of the cone bits 4 and 5 crush the gravel. It is carried backwards and ejected to the ground.

The cone bits 4, 5 in contact with the gravel rotate about their axis 8, 9 and crush the gravel while changing the contact area with the gravel.

If the cone bits 4, 5 are damaged or worn out, the casing 2 is pulled back and replaced. In this case, if the hydraulic cylinders 15, 15 are actuated in advance to rotate the cam member 14 by a predetermined angle, the convex cam portion 14B that was pressing the inner end of the support member 6 of the first cone bit 4 will move inside the corresponding inner end. Because it comes off from the edge,
When the casing 2 is pulled back, the cone bit 4 hits the tip of the buried pipe 1 and is drawn into the buried pipe 1, and can be retreated as it is, and when it reaches the rear end of the buried pipe 1, the support member 6 is attached to the annular member. It can be easily removed by pulling it out through the square holes 16 and 17 of 12 and 13. The second cone bit 5 can also be removed from the square hole by pulling out the retaining pin 20. In this way, each cone bit 4, 5 is removed and replaced or repaired.

To install a new cone bit or a repaired cone bit, insert the supporting member 6 of the first cone bit 4 into the square holes 16, 17 of the annular members 12, 13, and insert the inner end into the cam of the cam member 14. The second cone bit 5, which is located on the surface 14A, has its support member 7 connected to the annular member 12,
13 into the square holes 18 and 19, and remove the retaining pin 20.
Hit it to prevent it from coming out.

After this, the casing 2 is moved forward, and when the cone bits 4 and 5 are placed in a position protruding from the tip of the buried pipe 1, the hydraulic cylinders 15 and 15 are operated by remote control, and the cam member 14 is rotated by a predetermined angle. Since the cam portion 14B of the cam member 14 pushes up the inner end of the support member 6, the support member 6 is pressed against the inner surfaces of the square holes 16 and 17 and is firmly fixed, and the base of the cone bit 4 is pushed up against the buried pipe 1. It is placed at a position that is approximately the same as or protrudes from the outer diameter of the buried pipe 1, and is placed in a position where it can crush gravel in the forward direction of the buried pipe 1.

〔Effect of the invention〕

As explained above, the present invention provides a plurality of first tubes whose axes face the center of the front position of the guide tube inside the tip of the guide tube of the casing that can be inserted into the interior of the buried pipe.
A tricomb bit and a plurality of second cone bits whose axes face outward are arranged in an annular manner, and a support member to which the first and second cone bits are rotatably attached is fixed to the inner periphery of the leading pipe. The inner end of the annular cam member is inserted into the through hole of the provided annular member as closely as possible, and the inner end of the support member is placed along the inner periphery of the guide pipe, and the inner end of the annular cam member is rotatable by a driving means such as a fluid cylinder. By contacting the peripheral surface and rotating this cam member, the cam part of the cam member presses the inner end of the support member toward the center of the leading pipe and fixes it, so the cone bit is not damaged or worn out. In this case, by rotating the cam member, the diameter of the cone bit can be reduced to a state where it can be buried in the buried pipe, and maintenance such as replacement or repair of the cone bit can be performed by pulling back the casing. It is extremely easy to attach and detach as it only needs to be inserted, and there is no need to worry about attaching or detaching during excavation work. In addition, since the cone bit is arranged in a ring at the tip of the lead pipe, it can crush the ground and gravel at the entry point of the buried pipe, and the central part of the lead pipe can be taken in as is, reducing the excavation area to 1/2 that of conventional methods. It has various effects such as being able to excavate more efficiently by reducing the amount by 2 to 1/3.

In the illustrated embodiment, the first and second cone bits 4 and 5 are alternately arranged in four pieces each, but the second cone bits 5 may be arranged every second cone bit. The number of installations is not limited to the illustrated embodiment, and can be increased or decreased as appropriate depending on the purpose of use.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional perspective view of the main part showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view of the same. FIG. 3 is a front view showing the arrangement of the first and second cone bits, and FIG. 4 is a sectional view corresponding to FIG. 2. DESCRIPTION OF SYMBOLS 1... Buried pipe, 2... Casing, 3... Leading pipe, 4... First cone bit, 5... Second cone bit, 6, 7... Support member, 12, 13...
...Annular member, 14...Cam member, 14B...Cam portion, 15...Hydraulic cylinder, 16, 17, 18,
19...square hole, 20...retention pin.

Claims (1)

[Claims] 1. A plurality of first cone bits whose axes face the center of the forward position of the leading pipe inside the tip of a leading pipe of a casing that can be inserted into the inside of the buried pipe, and a plurality of first cone bits whose shaft centers face outward. A plurality of second cone bits facing each other are arranged in an annular shape, and a support member on which the first and second cone bits are rotatably mounted is inserted into a through hole of an annular member fixed to the inner periphery of the leading pipe. The inner end of this supporting member is inserted along the inner periphery of the leading pipe and is brought into contact with the inner circumferential surface of an annular cam member which is rotatable by a driving means such as a fluid cylinder. An underground excavation device characterized in that the inner end of the support member is pressurized and fixed in the center direction of the guide pipe by the cam portion of the cam member by rotation. 2. The underground excavation apparatus according to claim 1, wherein the first and second cone bits are arranged alternately.