JP2602044Y2 - Ring bit - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a ring bit,
Particularly, as a bit for foundation work, the biting property of the excavation cutting edge is improved over a long period of time.

[0002]

Conventionally, as the bits of this kind, hemispherical protruding end of the insert tip, conical, and chisel
For example, a rotating and hitting type bit is disclosed in Japanese Utility Model Laid-Open No. 57-1788.
No. 89, JP-A-58-22289, JP-A-6-22
No. 0-85186. In addition,
In the technical field for foundation work, a sleeve-shaped casing body
And a casing vial to which a drill bit is attached.
For example, Japanese Patent Application Laid-Open No. Sho 63-217093,
It is disclosed in, for example, JP-A-2-23670.

[0003]

[Devised Problems to be Solved] However, rotation punch
Bit撃式is a button bit, not good Eating with resistance of the cutting edge, the conical bit, but Eating with resistance in the initial stage may, wear quickly, problems drilling speed is abruptly drop there were. Also disclosed in Japanese Patent Application Laid-Open No. 60-85186.
The bit shown has good bite, but the inside is small
The problem is that the wear of the insert-shaped insert
there were. In addition, the casing bit is
The problem is that its use is restricted because it is built into
was there.

[0004] In view of the above, the present invention aims to provide a ring bit having a cutting edge shape with improved biting and abrasion resistance.

[0005]

This invention Means for Solving the Problems] has been made in view of the above, the tip of the bit body to form a sleeve-like
The head has a dust discharge groove and an insert made of cemented carbide.
The insert tip is equipped with this insert tip
Has a truncated conical cylinder as its basic shape, and
At their protruding ends, make
To provide a ring bit.

That is, the insert tips are adjacent to each other.
On the tip of the head defined by the
In addition, with respect to the rotary excavation direction,
Planted alternately inward on the inner edge
It is intended to be included. In this case, the digging blade
First, it has a large apex angle theta ₂ than the apex angle theta ₁ of the conical surface
A pair of inclined planes at a circumferential position of 180 ° are formed.
In this way, a strip-shaped edge is formed at the truncated part.
In addition, this band-shaped edge forms the rotation center of the bit body 1
When they are set as references, they are located in the respective radial directions .

[0007]

The ring bit according to the present invention has an inner peripheral side and an outer peripheral side.
The cutting edge of the insert tip implanted in the
An edge is formed, and the band-shaped edge is located in the radial direction of the bit body. In this case,
The insert tip is basically a truncated conical cylinder.
And the excavation edge formed at the truncated part is
180 ° circumferential direction having a large apex angle theta ₂ than the apex angle theta ₁
By forming a pair of inclined planes at the opposite positions,
It constitutes a strip-shaped edge. Therefore, the inner circumference
And the drilling edge on the outer peripheral side has good biting properties,
As the length of the band edge is increased, wear resistance is reduced.
It is a good, such shall.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the ring bit of the present invention will be described below with reference to the drawings.

[0009] In Figures 1 and 2, 1 is a bit body which forms a sleeve <br/> shape, in its front end a head 2, a plurality
Repeat powder discharge groove 3 and the insert tip 4 made of cemented carbide have been found with. The insert tip 4 has a basic shape of a truncated conical cylindrical body.
The protruding end from the bit body 1 constitutes a cutting edge 5 . In this case, the powder discharge groove 3 has an annular end and an outer periphery.
By being recessed over the side surface,
The crushed powder is discharged to the rear of the bit body 1.

The cutting edge 4 is clearly shown in FIGS. 3 (a) to 3 (c), but has a frusto-conical shape as a basic shape.
It is something. Then, this truncated part is inclined plane 6 is formed in the 180 ° circumferential position with a large apex angle theta ₂ than the apex angle theta ₁ of the conical surface, the strip edges 7 of structure
It is. Therefore, this band-like edge 7 is used for
Works with effective biting against drilling
You.

The insert tip 4 having such a cutting edge 5 is provided with a bit defined by the powder discharge groove 3.
In the stump head 2 of the main body 1, an outer peripheral edge portion and an inner peripheral edge portion
Are alternately implanted in
It is inclined outward on the edge and inward on the inner edge
And the band edge 6 is the bit body 1
Are located in the radial direction with respect to the rotation center of. these
The configuration is to ensure that effective excavation functions are
It is considered.

[0012]

[Effect of the Invention] The present invention provides a sleeve as described above.
To insert the chip 4 to be implanted in the Jo of the bit body 1
The cutting edge 5 having a band-like edge 7 is formed, and the band-like edge 7 is located in the radial direction of the bit body 1. Therefore, the ring bit according to the present invention is formed by the rock edge of foundation work due to the presence of the band-shaped edge 7.
The bite and wear resistance are good for
It has the advantage that the life can be extended.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a ring bit of the present invention.

FIG. 2 is a plan view of FIG. 1 ;

FIG. 3 is a view showing an insert chip, (a) is a front view,
(B) is a side view, (c) is a plan view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bit body 2 Tip head 3 Powder discharge groove 4 Insert tip 5 Drilling blade tip 6 Inclined flat surface 7 Strip edge

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-222289 (JP, A) JP-A-60-85186 (JP, A) JP-A-63-217093 (JP, A) 178889 (JP, U) Jiko 2-23670 (JP, Y2) (58) Field surveyed (Int. Cl. ⁶ , DB name) E21B 10/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A sleeve-shaped bit body 1 has a
A plurality of powder discharge grooves 3 and a cemented carbide
An insert tip 4 made of
The insert tip 4 has a truncated conical cylindrical body as its basic shape.
At the protruding end from the bit body 1,
In each of the ring bits configured as above, the insert tip 43 is provided with an adjacent powder discharge groove.
3. At the tip head 2 sectioned by
In the excavation direction, on the outer peripheral side, outward, on the inner peripheral side
The cutting edge 5 is alternately implanted so as to be inclined inward, and the cutting edge 5 is larger than the apex angle θ ₁ of the conical surface.
At a circumferential position of 180 ° with an apical angle θ ₂
Due to the formation of the inclined plane 6,
Is formed with a band-like edge 7, and this band-like edge 7
There when relative to the center of rotation of the bit body 1, the ring bit <br/> it wants to and being located respectively in the radial direction.