JPH0630955Y2 - Drilling rig - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention is a pipe for excavating the ground to bury underground water and sewer pipes, gas pipes, underground cable burial pipes, etc. The present invention relates to an excavation device for burying a ground.

(Prior art) In order to bury water and sewer pipes and gas pipes in the ground, a conventional excavation method has been used in which a trench is cut from the surface of the earth, a pipe is laid inside the trench, and the soil is backfilled. However, in the case of burial across urban areas and main roads, it is often impossible to use the excavation method.For this reason, recently, pipes have been sequentially added while digging lateral holes while burying them. The construction method is used.

An excavating device using the above-mentioned construction method is designed to excavate the ground by using a drill generally called a scree auger and then push a pipe after the excavation.

However, when excavating the ground that contains a lot of rock in the ground, or when there is rock even in normal ground, the rock cannot be crushed with the above drill,
This rock bends the excavation path or damages the excavation head. Therefore, for excavation into such ground, an excavation device equipped with an excavation head having a crushing blade called a triconbit is used.

In a conventional drilling rig equipped with a tricone bit, a plurality of triconets are rotatably mounted in a radial direction on a drilling head in front of the drilling machine, and the tricone crushes rocks by rotating the drilling head. , It is designed so that it is taken into the excavation head and discharged backward to proceed with the excavation.

(Problems to be solved by the invention) By the way, since the above-mentioned tricone bit rotates due to collision with rocks, it is often worn or damaged. Therefore, it is necessary to replace or repair the tricone bit at any time.

However, in the case of excavating the ground at the tip position of the pipe when burying the pipe, this triconbit has a sheath pipe at a position where the outer end portion of the revolution of the triconbit is the same as the outer peripheral surface of the sheath pipe or slightly protrudes outward. It is not possible to push the sheath tube into the drill hole without drilling a drill hole of the same or slightly larger diameter. Therefore, when replacing or repairing the tricone bit, even if the drill head is pulled back through the sheath pipe, the tricone bit cannot be pulled back by grasping the sheath pipe.Therefore, the ground at the position where this drill head exists is excavated. The replacement and repair will have to be done, and the work will be difficult.

The present invention has been made for the purpose of solving the above-mentioned problems of the prior art, and at the time of excavation, the rotation radius of the revolution of the triconbit is made the same as or slightly larger than the outer diameter of the sheath pipe,
An object of the present invention is to provide an excavating device which is smaller than the inner diameter of the sheath pipe and which can be pulled out rearward, and which facilitates replacement of the excavation head itself, replacement of the tricone bit, and repair.

[Constitution of device]

(Means for Solving the Problems) In order to solve the problems of the above-mentioned conventional technology, in the present invention, a bit cylinder having a side surface of an arc shape is provided with a tricone bit rotatably attached to the tip bearing portion. ,
The excavation head body is provided with a bit cylinder case that slidably supports the bit cylinder along its arcuate surface, and a hydraulic cylinder swingably supported inside the excavation head body is included in the bit cylinder. Connect to the end,
When the bit cylinder is retracted to the retreat limit, the outer peripheral end of the tricon bit farthest from the center of the drill head advances to at least the same position as the outer peripheral surface of the sheath pipe fitted onto the main body of the drill head, and moves forward. It is characterized in that the outer peripheral end of the triconbit can be positioned inward from the inner peripheral surface of the sheath tube when the tricone bit is caused to move.

(Operation) When the hydraulic cylinder is activated and the bit cylinder is retracted,
Due to the upper and lower arc surfaces of the bit cylinder, the outer peripheral edge of the Tricon bit farthest from the center of the drilling head projects to the same or slightly outside as the outer circumferential surface of the sheath pipe that is fitted onto the drilling head body. By driving, it is possible to dig a drill hole having a diameter larger than the outer diameter of the sheath pipe.

When exchanging the drilling head, replacing the tricone bit, or repairing,
When the hydraulic cylinder is driven to move the bit cylinder forward, the bit cylinder has an arc shape, and therefore the tricon bit at the tip end is displaced toward the center of the drill head as the bit advances. The outer peripheral end of the bit is located inward of the inner peripheral surface of the sheath tube so that the drilling head can be pulled back through the sheath tube to the rear side.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vertical side surface of a drilling head portion at a tip of a drilling device according to the present invention, and FIG. 2 shows a front view of the drilling head with a part thereof omitted.

The drilling head main body 1 is a cylindrical one having a vertical side surface shape of a U shape, and four tricone bits 3 and four auxiliary bits 4 (one in each figure is provided on the outer periphery of the front plate 2 thereof. Are shown, and the other parts are attached with the same reference numerals only in their positions), and the tricon bits 3, 3 ...
In between, there are holes 5 and 5 for crushing rocks and excavated earth and sand.

As shown in FIG. 1, the tricone bit 3 is rotatably attached to a bearing portion 7 at the tip of a bit cylinder 6 by a shaft 8, and its shape has a truncated cone shape when viewed from the side. As described above, the three ridges 9a, 9b and 9c are provided, and the large-diameter ridge 9a is positioned on the outer side and is pivotally supported.

The bit cylinder 6 has arcuate surfaces 6a and 6b whose upper and lower surfaces are centered at one point, and a locking surface 6c is formed near the tip of the arcuate surface 6a on the outer surface side.

A bit cylinder case 10 having arc surfaces 10a and 10b into which the bit cylinder 6 is slidably fitted along the arc surfaces 6a and 6b is formed inside the drill head body 1. An inclined surface 10c which is aligned with the locking surface 6c of the bit cylinder 6 is formed in the vicinity of the outer end of the upper arc surface 10a of the case 10, and when these surfaces 6c, 10c are in close contact with each other, The retreat limit is set, at which time Tricon bit 3
The outer peripheral end 3'of the position most distant from the center of the excavating head is located at least at the same position as the outer peripheral surface of the sheath pipe 11 which is sheathed on the excavating head body 1 or slightly outwardly protruding.

At the inner end of the bit cylinder 6, a piston rod 13 of a hydraulic cylinder 12 whose base is pivotally supported by the excavation head body 1 is provided.
The hydraulic cylinder 12 is expanded and contracted to move the bit cylinder 6 between a retracted position shown by a solid line in FIG. 1 and an advanced position shown by a chain line in FIG. When the chain line is advanced, the outer peripheral end 3'of the tricon bit 3 is positioned inside the inner peripheral surface of the sheath tube 11.

The sheath pipe 11 has a buried pipe 14 connected to its rear portion,
The sheath pipe 11 is provided on the outer peripheral surface of the drill head body 1 with the roller 1
The excavation head main body 1 is rotatably driven by a driving means (not shown) in the sheath pipe 11 by being externally fitted with 5, 5 interposed therebetween.

An inner pipe 16 is connected to the rear portion of the excavation head main body 1, and a conveying means (not shown) such as a screw for carrying the excavated soil backward is provided in the inner pipe 16 as usual.

The auxiliary bit 4 is in the form of a roller having two ridges 4a, 4a, is positioned in the hole 17 of the front plate 2 of the excavation head body 1, and is rotatably supported by the bearing portion 18.

The tricone bit 3 is not limited to the ridges 9a, 9b, 9c, and may have a shape in which a large number of wart-shaped projections are coated on the conical peripheral surface.
It is needless to say that the number of installations can be increased or decreased depending on the size of the drilling head or the purpose of use.

Next, the operation will be described.

When excavating the ground, when the hydraulic cylinder 12 is shortened and the bit cylinder 6 is placed in the final retracted position (the position shown by the solid line in FIG. 1), the locking surface 6c of the bit cylinder 6 tilts the bit cylinder case 10. It is placed in a fixed state in close contact with the surface 10c. At this time, the outer peripheral end 3 ′ of the tricon bit 3 pivotally supported by the tip of the bit cylinder 6 is placed at a position slightly protruding outward from the outer peripheral surface of the sheath tube 11.

When the excavating head body 1 is rotationally driven in this state,
The ground is crushed and excavated not only on the ground but also on rocks by the revolution of the Triconbit 3 and rotation by contact with the ground.
5 is taken into the excavation head main body 1 and is carried out rearward by a conveying means (not shown) in the inner pipe 16.

When the tricon bit 3 is worn or damaged, or when the excavating head itself is replaced, when the hydraulic cylinder 12 is extended, the bit cylinder 6 advances along the circular arc surfaces 10a and 10b of the bit cylinder case 10. As a result, the tricone bit 3 at the tip of the bit cylinder 6 advances toward the front of the excavation head body 1 as shown by the chain line in FIG. The outer peripheral end 3 ′ of is located inside the inner peripheral surface of the sheath tube 11.

If the excavation head body 1 is pulled back after this, the excavation head body 1 can be pulled back backward through the inside of the sheath pipe 11, and the tricone bit 3 can be replaced or repaired in the pit. When exchanging the entire excavation head, the excavation head body 1 may be carried out from the pit to the ground, a new excavation head body may be suspended, and the excavation head body 1 may be pushed again to the excavation position.

[Effect of device]

As described above, according to the present invention, even an excavator equipped with a tricone bit can easily replace and repair the tricone bit without excavating the ground, and in particular, a small-diameter pipe (100φ that cannot be inserted into a pipe for work). It is highly useful as an excavation device for burial (see below). Further, the tricone bit is supported at the tip of the bit cylinder. Since the bit cylinder has an upper surface and a lower surface which are arcuate surfaces and is slidably supported on the bit cylinder case of the excavation head body, the tricone bit is operated by the hydraulic cylinder. The bit can be taken in and out smoothly, and the projecting position of the outer edge of the tricon bit can be arbitrarily selected without any step. The triconbit has a large bearing strength and is sufficiently compatible with rocky ground. There are various effects such as being possible.

[Brief description of drawings]

1 is a vertical side view showing an embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is a vertical side view of a bit cylinder, and FIG.
The figure is a plan view of the same. 1 ... excavating head body, 2 ... front plate, 3 ... tricone bit, 4 ... auxiliary bit, 5 ... shear hole, 6 ... bit cylinder, 10 ... bit cylinder case, 11 ...
Sheath pipe, 12 ... Hydraulic cylinder, 14 ... Buried pipe, 16 ...
… Inner tube.

Claims (1)

[Scope of utility model registration request] 1. A bit cylinder rotatably rotatably attached to a tip bearing portion and having a side surface of an arc shape is provided, and the excavation head main body slidably supports the bit cylinder along the arc surface. A bit cylinder case is attached, and a hydraulic cylinder swingably supported inside the excavating head body is connected to an inner end portion of the bit cylinder, and the bit cylinder is a tricon when retracted to the backward limit. The outermost end of the bit farthest from the center of the drilling head advances to at least the same position as the outer circumferential surface of the sheath pipe fitted onto the drilling head main body, and when the bit is advanced, the outer peripheral end of the tricon bit is inside the sheath pipe. An excavation device characterized in that it can be located inward from the peripheral surface.