JP2003314182A - Air hammer apparatus with reaming bits - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air hammer apparatus with reaming bits which stably carry out expansion/contraction motions. <P>SOLUTION: Each of the reaming bits 14a, 14b is formed of a bit body 32a or 32b slidably arranged at the tip of a hammer case 12, and a bit wing 34a or 34b rockably supported by the bit body 32a or 32b. When each of the bit bodies 32a, 32b moves in a direction that recedes from the tip of the hammer case 12, each of the bit wings 34a, 34b has its base-side end pressed to a projection 62 formed at the tip of the hammer case 12, whereby each of the bit wings 34a, 34b is forcedly rocked. Thus, the tip of each of the bit wings 34a, 34b is rotated outward from a peripheral surface of the bit body 32a or 32b, to thereby extend the diameter of each bit. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diameter-expanding bit type air hammer device, and more particularly to a diameter-expanding bit type air hammer device for excavating the ground while following a casing pipe.

[0002]

2. Description of the Related Art When excavating the ground with an air hammer device, in order to prevent the collapse of the formation, the casing pipe may be excavated while being followed. In this case, in order to facilitate the insertion of the casing pipe into the ground, the air hammer device is equipped with a diameter expansion bit capable of excavating a diameter larger than the diameter of the casing pipe.

Conventionally, a diameter-expanding bit of this type has been disclosed in Japanese Patent Laid-Open No.
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. 132403, the bit blade portion is swingably supported by a pin at the tip of the bit body, and the tip of the bit blade portion is projected from the outer periphery of the main bit to reduce the bit diameter. I am trying to enlarge it.

[0004]

However, in the conventional diameter-expanding bit, since the bit blade portion is simply supported by the pin, a large load is apt to be applied to the pin and there is a problem in strength. . Further, since the bit blade portion is configured to swing independently, there is a drawback that the expansion / contraction operation becomes unstable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diameter-expanding bit type air hammer device in which a bit stably expands and contracts.

[0006]

In order to achieve the above object, the present invention relates to a diameter-expanding bit type air hammer device for excavating the ground by giving impact vibration to an expandable and contractible bit with an air hammer. And a bit body slidably provided at the tip of the hammer case and impacted by the air hammer, and pivotally supported on the bit body via spindles formed on both side surfaces. The bit wing, which expands / contracts by oscillating in the bit radial direction, and the divided bodies formed separately for each bit wing pivotally supported by the bit body are bound together, and are engaged with the base of the bit wing. When the bit body slides, the bit wing moves forward when the bit body slides. Bit diameter by oscillating the bit radially while being pressed to the hammer cover engagement portion provides a diameter bit type air hammer apparatus characterized by scaling.

According to the present invention, when the bit body slides, it swings in the bit radial direction while being pressed by the hammer cover engaging portion provided at the tip of the hammer case, and the bit diameter expands and contracts. As a result, a stable expansion / contraction operation can be ensured.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a diameter-expanding bit type air hammer device according to the present invention will be described below in detail with reference to the accompanying drawings.

1 and 2 are a front view and a bottom view, respectively, showing an embodiment of a diameter-expanding bit type air hammer device according to the present invention. Each drawing shows a state (a) when the diameter of the diameter-expanding bit type air hammer device is expanded and a state (b) when the diameter is reduced.

As shown in FIGS. 1 and 2, the expanding bit type air hammer device 10 of the present embodiment is provided with a hammer case 12.
A pair of diameter-expanding bits 14 that can be expanded and contracted at the tip of the
The ground is excavated by vibrating the a and 14b by the air hammers 16a and 16b built in the hammer case 12.

The hammer case 12 includes an air hammer 16a,
The hammer case main body 18 has a built-in 16b and a hammer cover 20 having the expanding bits 14a and 14b attached thereto.
It is integrated by being attached to the tip part of 8.

The hammer case body 18 is formed in a columnar shape, and a pair of air hammer accommodating holes 22 are provided inside thereof.
a, 22b and a pair of earth discharging holes 23, 23 are formed.

The air hammer receiving holes 22a and 22b are formed parallel to the axis of the hammer case body 18, and the air hammer 16 is inserted into the air hammer receiving holes 22a and 22b.
a and 16b are accommodated and arranged.

The earth discharging holes 23, 23 are also provided in the hammer case body 18.
Is formed parallel to the axis of the hammer case body 18
It is connected to the soil discharge pipe 25 connected to the base of the.
The excavated earth and sand excavated by the diameter-expanding bits 14a and 14b are discharged to the ground via the earth discharging hole 23 and the earth discharging pipe 25.

Further, at the base of the hammer case main body 18, an air supply pipe 27 for supplying compressed air required for operating the air hammers 16a, 16b, and the air hammers 16a, 1b.
An exhaust pipe 28 for exhausting the air used for the operation of 6b is connected.

The air hammers 16a and 16b are cylindrical cylinders 24a and 24b, and the cylinder 24.
and pistons 26a and 26b which slide inside a and 24b. The pistons 26a and 26b slide in the cylinders 24a and 24b by air supply and exhaust, and the pistons 26a and 26b slide in the cylinders 24a and 24b, so that the diameter expansion bits 14a and 14b are vibrated by impact. .

The hammer cover 20 is formed in a disk shape and has a pair of bit mounting holes 30a, 3a extending parallel to the axis thereof.
0b is formed. A pair of bit mounting holes 30a, 3
0b is formed corresponding to the air hammer receiving holes 22a and 22b formed in the hammer case body 18, and the bit expansion holes 14a and 14b are inserted into the bit mounting holes 30a and 30b.
b is attached.

The expanding bits 14a and 14b are shown in FIGS.
As shown in FIG. 3, the bit bodies 32a and 32b and the bit wings 34a and 34b are included.

The bit bodies 32a, 32b include shank portions 36a, 36b and bit wing support portions 38a, 38b formed at the tips of the shank portions 36a, 36b.
It consists of and.

The shank portions 36a and 36b are formed in a columnar shape, and the slash portion 40 having a predetermined width is provided near the upper end portion thereof.
a and 40b are formed. Bit body 32a, 3
2b is attached to the hammer cover 20 by fitting the shank portions 36a and 36b into the bit mounting holes 30a and 30b of the hammer cover 20.

The hammer cover 20 is provided with spline bushes 42a and 42b, which communicate with the bit mounting holes 30a and 30b, and the shank portion 36.
a and 36b are spline bushes 42a and 42b.
It is slidably supported in the axial direction while being restricted from rotating in the circumferential direction.

Also, the spline bushes 42a, 4
Stopper rings 44a and 44b are attached to the upper end portion of 2b, and the stopper rings 44a and 44 are the squeezing portions 40 formed on the shank portions 36a and 36b.
It is fitted in a and 40b. Shank part 36a, 36
The sliding range of b is regulated by the stopper rings 44a and 44b contacting the upper edge or the lower edge of the cut portions 40a and 40b.

The bit wing supports 38a, 38b are
It is formed in a rounded rectangular block shape, and recesses 46a and 46b for accommodating the bit wings 34a and 34b are formed on the lower surface thereof.

The recesses 46a and 46b are formed by the bit wings 3
It is formed in a T-shape having a wide tip groove width corresponding to the shapes of 4a and 34b. Bearing grooves 48, 48 for mounting bearings 54, 54, which will be described later, are formed on both wall surfaces of the base ends of the recesses 46a, 46b. This bearing groove 48,
48 is formed by opening on the side surface of the bit wing support portions 38a, 38b, and the bearing 5 is opened through this opening portion.
4, 54 are inserted.

As shown in FIGS. 2 and 3, the bit wings 34a and 34b are formed in a T-shape with an enlarged tip, and a large number of metal chips 50, 50 are formed on the surface thereof.
... has been planted. These bit wings 34a, 34
Tapered surfaces 58a and 58b are formed on the upper surface of the base end portion of b, and columnar support shafts 52 and 52 are formed on both side surfaces of the base end portion.

A bearing 54 is attached to the support shaft 52, and the bearing 54 is formed in a block shape matching the shape of the bearing groove 48. The bit wings 34a and 34b are
By fitting the bearing 54 into the bearing groove 48 of the bit wing support portions 38a, 38b, the bit body 32a,
It is attached to 32b. The bit wings 34a, 34b mounted on the bit bodies 32a, 32b are swingably supported by the bit bodies 32a, 32b with their base ends protruding from the peripheral surfaces of the bit bodies 32a, 32b. Then, by swinging around the support shaft 52, the tip end thereof projects from the outer periphery of the bit bodies 32a and 32b, and the outer diameters of the bit bodies 32a and 32b are expanded or contracted.

Expanding bit 14 constructed as described above
a and 14b are the bit bodies 32a and 3 as described above.
The shank portions 36a, 36b of 2b are fitted into the bit mounting holes 30a, 30b of the hammer cover 20 to be mounted on the hammer cover 20, and slidably supported on the tip end of the hammer cover 20.

Here, as shown in FIGS. 1 and 3, a protrusion (engagement member) 62 is formed at the center of the tip surface of the hammer cover 20.
Is formed so as to project in the axial direction, and the expanded bit 14
When the a and 14b are mounted on the hammer cover 20, the tapered surfaces 58a and 58b of the bit wings 34a and 34b are engaged with the tips of the protrusions 62. Bit wing 34a,
34b is interlocked with the sliding of the bit bodies 32a and 32b, and the tapered surfaces 58a and 58b thereof are forcibly swung by being pressed by the protrusion 62. That is, when the bit bodies 32a and 32b move in the direction of retracting from the tip end surface of the hammer cover 20 (when the expanded diameter bit type air hammer device 10 is pressed against the ground), the bit wings 34a,
The taper surfaces 58a, 58b of 34b are forcibly pressed by the protrusion 62, whereby the bit wing 34
a and 34b are forcibly rocked. As a result, the tip end portions of the bit wings 34a and 34b are attached to the bit body 32a,
The bit diameter is expanded by rotating outward from the outer peripheral surface of 32b. On the other hand, when the bit bodies 32a and 32b move in a direction projecting from the tip end surface of the hammer cover 20 (when the diameter-expanding bit air hammer device 10 is pulled up from the ground), the bit wings 34a and 34b swing in the diameter-reducing direction by their own weight. As a result, the tip portions of the bit wings 34a and 34b rotate inward from the outer peripheral surfaces of the bit bodies 32a and 32b, and the bit diameter is reduced.

The operation of the expanded diameter bit type air hammer device 10 of the present embodiment configured as described above is as follows.

First of all, the diameter expanding bit type air hammer device 1
A method of assembling 0 will be described. As shown in FIG. 3A, first, the support shaft 5 of the bit wings 34a and 34b.
Bearings 54, 54 are attached to 2, 52, bit body 3
It is fitted in the bearing grooves 48, 48 formed in 2a, 32b. As a result, as shown in FIG. 3B, the bit wings 34a and 34b are mounted on the bit bodies 32a and 32b and are swingably supported.

Next, the shank portions 36a, 36b of the bit bodies 32a, 32b are fitted into the bit mounting holes 30a, 30b of the hammer cover 20. As a result, FIG.
As shown in FIG. 5, the diameter expansion bits 14 a and 14 b are mounted on the hammer cover 20.

Next, the hammer cover 20 is attached to the hammer case 1.
Attach to the tip of 2. As a result, as shown in FIG. 3D, the expanded diameter bits 14a and 14b are attached to the air hammer 16
It is connected to the tips of a and 16b.

The expanding bit type air hammer device 10 is shown in FIG.
As shown in (a) and FIG. 2 (a), when pressed against the ground, the bit bodies 32a, 32b move in the direction of retreating from the tip end surface of the hammer cover 20, and the bit wings 34
The tapered surfaces 58a and 58b of a and 34b are pressed by the protrusion 62 and swing. As a result, the bit wing 34
The tips of a and 34b project from the outer peripheral surfaces of the bit bodies 32a and 32b, and the bit diameter increases. As a result, it becomes possible to excavate a hole having a diameter larger than that of the subsequent casing pipe 64.

On the other hand, as shown in FIGS. 1 (b) and 2 (b), the bit bodies 32a and 32b are attached to the hammer cover 20.
When the bit wings 34a and 34b move in a direction projecting from the tip end surface of the No. 3, the bit wings 34a and 34b swing in the diameter reducing direction by their own weight.
As a result, the bit diameter becomes smaller than the inner diameter of the casing pipe 64, and the expanded diameter bit type air hammer device 10 can be collected through the inside of the casing pipe 64.

As described above, according to the expanded diameter bit type air hammer device 10 of the present embodiment, the bit bodies 32a, 3
When 2b moves in the direction of retreating from the tip of the hammer cover 20, the bit wings 34a and 34b always expand in diameter, so that stable expansion / contraction operation can be ensured.

The diameter-expanding bit type air hammer device 10 of the present embodiment has been described by taking as an example a diameter-expanding bit type air hammer device equipped with two diameter-expanding bits. The number is not limited and may be one or three or more.

FIGS. 4 and 5 are a front view and a bottom view of a diameter-expanding bit type air hammer device 70 in which four diameter-expanding bits are installed, respectively. As shown in the figure, four diameter-expanding bits 74a to 74d are installed at a tip portion of the hammer case 72 at predetermined intervals. The structure of the diameter-expanding bits 74a to 74d is the same as the diameter-expanding bits 14a and 14b of the diameter-expanding bit type air hammer device 10 described above.

In the center of the hammer case 72,
Normal bit, ie bit 76a without scaling function,
A pair of 76b is installed.

Further, as in the above-described diameter-expanding bit type air hammer device 10, the hammer case 72 is provided with an earth discharging hole 90, and the earth discharging hole 90 and an earth discharging pipe 92 connected to the base of the hammer case 72 are provided. The excavated earth and sand is discharged via the.

An earth digging hole 90 is formed in the hammer case 72, and excavated earth and sand is discharged through the earth digging hole 90 and an earth unloading pipe 92 connected to the base of the hammer case 72.

Further, at the base of the hammer case 72, an air supply pipe 94 for supplying pressure air required for operating the air hammers 16a, 16b and an exhaust pipe for exhausting air used for operating the air hammers 16a, 16b. 96 is connected.

When the expanded diameter bits 74a to 74b are mounted on the hammer case 72, the tapered surfaces 82a to 82d of the bit wings 80a to 80d are formed on the projections (pressing members) 78 formed to project from the tip of the hammer case 72. Engage. Bit wings 80a-80d are bit bodies 8
The taper surface 82a is interlocked with the vertical movement of 4a to 84d.
When ~ 82d is pressed by the protrusion 78, it is forcibly swung, and the bit diameter is expanded or contracted.

As described above, according to the present invention, a stable expansion / contraction operation can be ensured even when a plurality of expanding bits are installed.

[0044]

As described above, according to the present invention,
When the diameter-expanding bit-type air hammer device is pressed against the ground, the bit wing always expands in diameter, so a stable expansion / contraction operation can be secured.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a diameter-expanding bit type air hammer device according to the present invention.

FIG. 2 is a bottom view showing an embodiment of a diameter-expanding bit type air hammer device according to the present invention.

[Fig. 3] Assembly drawing of a diameter expansion bit type air hammer device

FIG. 4 is a front view showing another embodiment of the diameter expanding bit type air hammer device according to the present invention.

FIG. 5 is a bottom view showing another embodiment of the diameter expanding bit type air hammer device according to the present invention.

[Explanation of symbols]

10 ... Expanding bit type air hammer device, 12 ... Hammer case, 14a-14b ... Expanding bit, 16a-16b ... Air hammer, 18 ... Hammer case main body, 20 ... Hammer cover, 22a-22b ... Air hammer receiving hole, 23 ... Ejection Earthen hole, 24a-24b ... Cylinder, 25 ... Exhaust pipe, 2
6a-26b ... Piston, 27 ... Air supply pipe, 28 ... Exhaust pipe, 30a-30b ... Bit mounting hole, 32a-32b ...
Bit body, 34a-34b ... Bit wing, 36
a-36b ... Shank part, 38a-38b ... Bit wing support part, 40a-40b ... Constriction part, 42a-42
b ... Spline bush, 44a-44b ... Stopper ring, 46a-46b ... Recess, 48 ... Bearing groove, 50 ...
Metal tip, 52 ... Support shaft, 54 ... Bearing, 58a to 58
b ... Tapered surface, 62 ... Protrusion, 64 ... Casing pipe, 70 ... Expanding bit type air hammer device, 72 ... Hammer case, 74a to 74d ... Expanding bit, 76a to 76b
... Bits, 78 ... Protrusions, 80a-80d ... Bit wings, 82a-82d ... Tapered surfaces, 84a-84d ... Bit bodies, 90 ... Excavation holes, 92 ... Exhaust pipes, 94 ...
Air supply pipe, 96 ... Exhaust pipe

Claims (3)

[Claims] 1. A diameter-expanding bit type air hammer device for excavating the ground by giving impact vibration to a bit that is expandable / contractible by an air hammer, and a hammer case for accommodating the air hammer, and sliding on a tip portion of the hammer case. A bit body, which is freely provided and to which impact vibration is given by the air hammer, and a bit body that is pivotally supported by the bit body via support shafts formed on both side surfaces and swings in the bit radial direction, expands and contracts the bit diameter. A bit wing, and a hammer cover provided at the tip of the hammer case that binds the divided bodies formed separately for each bit wing pivotally supported by the bit body and engages with the base of the bit wing; When the bit body slides, the bit wing is pressed by the hammer cover engaging part and Diameter bit type air hammer apparatus characterized by bit diameter is scaled by swinging. 2. The expanded diameter bit type air hammer according to claim 1, wherein the hammer case is provided with an air supply pipe for supplying pressure air to the air hammer and an exhaust pipe for discharging exhaust air. apparatus. 3. The diameter expanding bit type air hammer device according to claim 1, wherein the hammer case and the hammer cover are provided with through holes for discharging soil.