JPH06323078A - Excavator - Google Patents

Abstract

PURPOSE:To improve durability by improving strength of a hole expanding bit, and excavating efficiently with low torque rotation. CONSTITUTION:A slidable cylinder body 20 is arranged between a device 7 and a hitting collar 2. A hitting ring 21 to be arranged between the step parts 17 and 18 is arranged on the base end of this cylinder body 20. A hole expanding bit 22 having a diameter larger than the hitting collar 2 is arranged on the tip projecting from the hitting collar 2 of the cylinder body 20. Thereby, since the whole excavation surface K is excavated by the hole expanding bit 22 and a bit head 11, rotational resistance of the bit head 11 and the hole expanding bit 22 is reduced, so that a device can be rotated with low torque. Thereby, abrasion of a rotation transmitting part such as a spline groove is reduced. Partial abrasion of the bit head 11 and the hole expanding bit 22 is also reduced, so that durability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator used for excavating a buried pipe in the ground for water wells, anchor works, landslide prevention, etc., and more particularly to an excavator equipped with a hole-expanding bit.

[0002]

2. Description of the Related Art Conventionally, in excavation in which a casing pipe made of steel pipe of this kind is buried in the soil, a device is connected to the tip of a drill hammer, a bit head is provided at the tip of the device, and the device protrudes from the tip of the casing pipe. An impact force and a rotational force are applied to the bit head to perform excavation, and the rotational force is transmitted from the drill hammer to the device via a spline groove, for example. In order to easily insert the casing pipe into the ground, a bit device that can be expanded to a diameter larger than that of the casing pipe is used. As the bit device, a bit device having substantially the same diameter as that of the device is provided on the bottom surface of the device. A bit device for forming a semicircular two-divided block and projecting these blocks from the outer peripheral surface of the device by a predetermined amount of excavation to increase the drilling diameter is proposed in Japanese Examined Patent Publication No. 3-21717 and divided into three. It is known that the block is projected from the outer peripheral surface of the device by a predetermined amount of excavation to increase the drilling diameter, and that the bit head is eccentric by an eccentric shaft to increase the drilling diameter.

[0003]

In each of the above-mentioned conventional bit devices, since the blocks divided into a plurality of pieces are projected and moved, or the bit head is eccentric by the eccentric shaft to expand the drilling diameter, the structure is complicated. Then, there is a problem that it becomes fragile and that the recovery work performed by reducing the bit device after the excavation becomes complicated. Further, even if the drilling diameter increases due to the above movement and eccentricity, the bit head itself does not expand, the tip area of the bit head becomes smaller than the excavation area, and the side surface of the bit head bites into the excavation surface during rotation. The rotation resistance becomes large, the bit head is easily worn partially, and a large rotation torque is required. Therefore, not only the bit head is easily worn partially, but also the spline groove that transmits rotation to the bit head. However, there was a problem that the items were worn out and could not be used in a short period of time.

Therefore, an object of the present invention is to provide a drilling device which improves the strength of a hole-expanding bit, enables efficient drilling with low torque rotation, and is excellent in durability.

[0005]

According to the present invention of claim 1, a bit head is provided at the tip of a device that receives an impact force and a rotational force, an outer step portion is formed on the outer periphery of the device, and the tip of a casing pipe. By providing an inner step portion to the striking collar provided in, the impact force is transmitted to the striking collar through these step portions, and by the impact force and the rotational force of the bit head protruding from the tip of the striking collar, In an excavating device for excavating, a slidable cylinder is provided between the device and a striking collar, and a striking ring disposed between the step portions is provided at the base end of the cylinder,
An expanding hole bit having a diameter larger than that of the hitting collar is provided at the tip of the hitting collar of the cylindrical body.

According to a second aspect of the present invention, a device is fitted in the cylindrical body and the rotational force of the device is transmitted to the hole-expanding bit.

[0007]

According to the structure of claim 1, the outer step portion of the device strikes the hitting ring to transmit the impact force to the hole expanding bit, and the hole expanding bit and the bit head hit the entire excavation surface. Excavation is performed.

According to the second aspect of the invention, the rotational force of the device is transmitted to the hole expanding bit, and the hole expanding bit is rotated together with the bit head for excavation. In addition, since the hole-expanding bit and the bit head strike the entire excavation surface while rotating, the rotational resistance is reduced, and rotation can be performed with low torque, wear of each part is reduced, and durability is improved. .

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 show a first embodiment of the present invention, in which a striking collar 2 made of steel or the like is welded to the tip of a casing pipe 1 made of steel pipe or the like. The thin-walled portion 3 on the base end side is inserted into the front end of the casing pipe 1, and the thick-walled portion 4 on the front end side is welded to the front end of the casing pipe 1. A drill hammer 5 is inserted into the casing pipe 1, a drill rod 6 for rotating the drill hammer 5 is connected to an upper portion of the drill hammer 5 in the drawing, and a device 7 made of steel or the like is connected to a lower portion thereof. The drill hammer 5 is
An air hammer (not shown) for transmitting an impact force to the device 7 by the compressed air sent from the drill rod 5 is incorporated. A spline groove 9 is integrally formed on the outer periphery of the connecting cylinder portion 8 located at the base end of the device 7, and the spline groove 9 is fitted into the vertical groove 10 of the drill hammer 5 to allow the drill hammer 5 to move. The rotational force is transmitted to the device 7, and the air hammer strikes the connecting tube portion 8 to transmit the impact force to the device 7. A bit head 11 is provided at the tip of the device 7, and the bit head 11 includes a plurality of bits 12 made of cemented carbide.
And a plurality of vertical grooves 13 are formed on the outer periphery of the bit head 11, and the outer periphery of the device 7 is
Three earth removal grooves are formed. Further, an exhaust passage 15 is formed inside the device 7, and the exhaust passage 15 is formed.
15 communicates with an exhaust port 16 at the tip of the bit head 11, compressed air supplied from the drill rod 6 blows out from the exhaust port 16 through the exhaust passage 15, and the blown compressed air excavates earth and sand or the like. At the same time, it is discharged above the casing pipe 1 through the vertical groove 13 and the earth discharging groove 14. Further, an outer peripheral step portion 17 which is an outer step portion is provided on the outer periphery of the device 7 on the proximal side.
Is formed, and an inner peripheral step portion 18 that is an inner step portion that engages with the outer peripheral step portion 17 is formed at the base end of the striking collar 2.

Reference numeral 20 denotes a cylindrical body slidably provided between the device 7 and the striking collar 2, and at the base end of the cylindrical body 20, a striking member arranged between the step portions 17 and 18 is provided. An abutment ring 21 is integrally provided, and the abutment ring 21 has an upper surface shown in the figure engaged with the outer peripheral step portion 17 and a lower surface shown in the figure engages with the inner peripheral stepped portion 18. Further, the tip of the cylindrical body 20 is
A projecting end of the striking collar 2 is integrally provided with a perforating bit 22 having a substantially cylindrical shape and having a diameter larger than that of the striking collar. Bit 12 is provided and the hitting color is
Between the tip of the hole 22 and the base end of the hole expanding bit 22, the hole expanding bit 22
An interval H is provided so that 22 can be slid vertically in the drawing. The device 7 is removably fitted into the tubular body 20 with a slight clearance, and the sliding surface 7A on the outer surface of the device 7 slides on the sliding receiving surface 20A on the inner surface of the tubular body 20. ,
It is configured to transmit the rotation of the device 7 to the cylindrical body 20,
Further, the distance between the tubular portion 20 and the hitting collar 2 is set to be slightly wider than the distance between the device 7 and the tubular body 20. The cylindrical body
20, the striking ring 21, and the hole-expanding bit 22 constitute a hole-expanding bit device 23 made of steel or the like.

The hole expanding bit device 23 and the hitting collar 2
The assembling method will be described. As shown in FIG. 3, the striking collar 2 is divided into two in the length direction.
The split collars 30 are fitted to the tubular portion 20 and the thick portions 3 of the split collars 30 are abutted with each other in the longitudinal direction.
After welding, the base end side of the hitting collar 2 is inserted into the casing pipe 1, and the base end side of the thick portion 4 of the hitting collar 2 and the tip end of the casing pipe 1 are circumferentially butted. Spot 32 is welded.

Next, the method of using the excavating device having the above-mentioned structure will be described. As shown in FIG. 1, a bit head 11 is inserted into a casing pipe 1 having a hole expanding bit device 23 and a striking collar 2 attached to its tip. And protrudes from the tip of the hole-expanding bit 22. Then, when the impact force and the rotational force are transmitted to the device 7 by the drill hammer 5, the bit head 11 rotates while hitting the excavation surface K, and at the same time, the outer peripheral step portion of the device 7
17 strikes the striking ring 21 and the impact force is transmitted to the expanding hole bit 22, the expanding hole bit 22 strikes the excavation surface K, and the outer peripheral step portion 17, the striking ring 21, and the inner peripheral step portion 18 The impact force is transmitted to the striking collar 2 through the casing, and the casing pipe 1
Is driven in. Further, the sliding surface 7A of the device 7
And the slide receiving surface 20A of the tubular body 20 slide to allow the hole expanding bit device 23
Rotates, and in this case, a part of earth and sand blown off by the compressed air from the exhaust port 16 and discharged upward through the vertical groove and the earth discharge groove 15 forms a gap between the sliding surface 7A and the sliding receiving surface 20A. A small gap is entered, friction between the sliding surface 7A and the sliding receiving surface 20A becomes large, and the rotational force of the device 7 is efficiently transmitted to the hole expanding bit device 23. And the bit head 11 and the hole expanding bit
The entire excavation surface K is hit by 22 and the bit head 11
Along with this, the hole-expanding bit 22 rotates almost integrally to perform excavation, and thus, the entire excavation surface K is struck by the hole-expanding bit 22 and the bit head 11 and excavates while rotating, so that rotation resistance is increased. Therefore, it is possible to rotate with low torque, wear of the spline groove 9 which is a rotation transmitting part is small, and there is no partial wear of the bit head 11 and the perforated bit 22, so that durability is improved. When the excavation to a predetermined depth, for example, a relatively deep depth of about 100 meters is completed, the bit head 11 is pulled up and collected as shown in FIG.

As described above, in this embodiment, the bit head 11 is provided at the tip of the device 7 which receives the impact force and the rotational force,
An outer peripheral step portion 17 that is an outer step portion is formed on the outer periphery of the device 7, and an inner peripheral step portion 18 that is an inner step portion is provided on the striking collar 2 provided at the tip of the casing pipe 1. In the excavating device which transmits the impact force to the striking collar 2 via the excavating device by the impact force and the rotational force of the bit head 11 protruding from the tip of the striking collar 2, the excavating device is provided between the device 7 and the striking collar 2. A slidable tubular body 20 is provided at the base of the tubular body 20, and a striking ring 21 disposed between the step portions 17 and 18 is provided at the base end of the tubular body 20.
Since the expanded hole bit 22 having a diameter larger than that of the hitting collar 2 is provided at the tip protruding from the outer peripheral step portion 17 of the device 7.
Impacts the striking ring 21 and the impact force is transmitted to the hole-expanding bit 22, and the hole-expanding bit 22 and the bit head 11 strike the entire excavation surface K for efficient excavation. In addition, since the hole-expanding bit device 23, which is separate from the device 7, is used to increase the hole-drilling diameter, the bit device can be simplified and is not easily broken.
By forming the substantially cylindrical shape, the member strength can be increased, and the occurrence of partial wear can be reduced.

As described above, in this embodiment, the device 7 is inserted into the tubular body 20 and the rotational force of the device 7 is increased by the hole expanding bit 22.
Since it is transmitted to the
Bit head for drilling with 22 and bit head 11
The rotation resistance of the 11 and the hole-expanding bit 22 is reduced and the torque can be rotated with a low torque. For example, the wear of the rotation transmitting portion such as the spline groove 9 is reduced, and the wear of the bit head 11 and the hole-expanding bit 22 is partially worn. It also reduces the durability and improves the durability. In addition, the bit expansion head 22
Is located rearward in the excavation direction, the bit head 11 excavates the center of the excavation surface K, and the central excavation portion serves as a guide, and the perforation bit 22 can efficiently excavate the outer peripheral side thereof.

Further, as an effect of the embodiment, when the striking collar 2 and the hole expanding bit device 23 are mounted on the casing pipe 1, the striking collar 2 is formed by a split collar 30 which is divided into two. Only the abutting points 31 in the longitudinal direction of the thick portions 3 are welded, and after welding, the base end side of the striking collar 2 is inserted into the casing pipe 1, and the base end side of the thick portion 4 of the striking collar 2 is inserted. By welding the circumferential butt portion 32 between the end of the casing pipe 1 and the casing pipe 1, it is possible to efficiently improve the mounting strength at a small number of welding points and improve the mounting workability thereof. Further, by providing an interval H that allows the hole-expanding bit 22 to slide in the vertical direction in the drawing, the casing pipe 1
On the other hand, the hole-expanding bit 22 moves up and down with a stroke of the interval H, whereby the striking force can be effectively applied to the excavation surface K.

FIG. 6 shows a second embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. In the case of using the hole-expanding bit 22A without the bit 22, the hole-expanding bit 22A and the bit head 11 rotate while hitting the front surface of the excavation surface K. Further, the rotation resistance is reduced, the rotation can be performed with a low torque, the partial wear is reduced, the durability is improved, and the operation and effect similar to those of the first embodiment are achieved. The hole-expanding bit 22A without a hole is suitable for excavation conditions without a boulder.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, means for applying an impact force and a rotational force to the device can be appropriately selected.

[0018]

According to the first aspect of the present invention, a bit head is provided at the tip of a device that receives an impact force and a rotational force, an outer step portion is formed on the outer periphery of the device, and a hitting provided at the tip of a casing pipe. An excavation device that is provided with an inner step portion on the collar, transmits an impact force to the striking collar through these step portions, and excavates by the impact force and the rotational force of the bit head protruding from the tip of the striking collar. In which a slidable cylinder is provided between the device and the striking collar, and a striking ring disposed between the step portions is provided at the base end of the striking body, and the striking collar of the cylinder is Since a hole-expanding bit with a diameter larger than the hitting collar is provided at the tip protruding from the end, the strength of the hole-expanding bit is improved, enabling efficient drilling with low torque rotation and durability. It is possible to provide an excellent drilling rig.

According to a second aspect of the present invention, a device is inserted into the cylindrical body and the rotational force of the device is transmitted to the hole-expanding bit. The strength of the hole-expanding bit is improved, and rotation of low torque is achieved. It is possible to provide an excavating device that enables efficient excavation and has excellent durability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a bottom view showing the first embodiment of the present invention.

FIG. 3 is an exploded perspective view of essential parts showing a first embodiment of the present invention.

FIG. 4 is a sectional view of an essential part showing a first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state in which the bit device according to the first embodiment of the present invention is pulled up.

FIG. 6 is a sectional view showing a second embodiment of the present invention.

[Explanation of symbols]

 1 Casing pipe 2 Hitting collar 7 Device 11 Bit head 17 Outer peripheral step (outer step) 18 Inner peripheral step (inner step) 20 Cylindrical body 21 Hit ring 22 Expanding bit

Claims (2)

[Claims] 1. A bit head is provided at the tip of a device that receives impact force and rotational force, an outer step portion is formed on the outer periphery of the device, and an inner step portion is provided at a striking collar provided at the tip of a casing pipe. In the excavation device that transmits an impact force to the striking collar through these steps and excavates by the impact force and the rotational force of the bit head protruding from the tip of the striking collar, the striking device and the striking device A slidable cylindrical body is provided between the collar and a striking ring disposed between the step portions at the base end of the cylindrical body, and the striking end of the cylindrical body projects from the striking collar. An excavator characterized by having a hole-expanding bit that is larger in diameter than the pad collar. 2. The excavator according to claim 1, wherein a device is fitted into the cylindrical body, and the rotational force of the device is transmitted to the hole expanding bit.