JPH0267105A - Hollow drill tool - Google Patents

Abstract

PURPOSE: To easily regulate a cutting segment mounted at a support by providing a contact part to be cooperated at least with part of an inner wall for limiting a receiving hole of the support to an edge of the segment. CONSTITUTION: The hollow drill tool comprises a tubular support 1 and a cutting segment 2 connected to the support 1. The support 1 has grooves 2e, 2f and 2g for forming a contact part 2h disposed at an outside and a contact part 2i disposed at an inside. Depths T of the grooves 2e, 2f and 2g are substantially coincident with a groove width S. In the case of mounting the segment 2 at the support 1, the segment is guided at bottom of the grooves 2e, 2f along an edge of a receiver hole 1d extended parallel to a longitudinal axis of the support 1, and locked. The segment 2 is effectively held by the support 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a hollow drilling tool having a tubular support;
In particular, the invention relates to a hollow drilling tool in which the support has in its front end region in the pushing direction a cutting segment which is at least partially retained by a U-shaped receiving hole open towards its front end.

[Prior art]

The known hollow drilling tool, which is described for example in DE 34 08 093 A1 with the above-mentioned construction, is particularly suitable for drilling large diameter holes in concrete, walls, rocks, etc. It is used for Cutting segments typically employ abrasive cutting bodies, particularly synthetic diamonds, embedded in a matrix.

The cutting segment is typically welded to the support by soldering. When welding, it is necessary to accurately adjust the cutting segment to the support, and as a result, it has been pointed out that the production cost of the drill tool increases.

[Disclosure of the invention]

The object of the invention is to propose a hollow drilling tool which is simple and inexpensive to manufacture and has a design that is difficult to damage, especially with regard to the connection of the cutting segment to the carrier.

To solve this problem, the hollow drilling tool according to the invention is provided with an abutment part on the edge of the cutting segment, the abutment part cooperating radially with at least a part of the inner wall defining the receiving hole of the support. It is characterized by being able to work.

According to the present invention, by providing the abutting portion on the edge,
It becomes possible to properly position the cutting segments mounted on the support in the radial direction. This facilitates or eliminates the radial adjustment of the cutting segment, which was previously required after attachment to the support. Furthermore, the increased contact area between the cutting segment and the support due to the abutment portion is particularly advantageous when welding the cutting segment to the support.

Advantageously, the abutment part is arranged at an edge of the cutting segment extending parallel to the longitudinal axis of the support.

This configuration is advantageous for performing axial corrections and is particularly important when the axial height of the cutting segment is large.

In a preferred embodiment of the invention, the abutment portion is arranged at the trailing edge of the cutting segment extending perpendicularly to the longitudinal axis of the support. As a result, the cutting segment is radially supported by a portion of the outer circumference of the support. By means of an abutment portion arranged at an edge extending perpendicularly to the longitudinal axis of the support, the cutting segment is firmly connected to the support at its rear end opposite to the pushing direction. The abutment part for supporting the cutting segment radially relative to the support can be arranged in various ways.

First, the abutment part of the cutting segment can be placed overlapping the outside of at least a part of the inner wall defining the receiving hole in the support. The abutting portion of the support is arranged to overlap with the inside of at least a portion of the inner wall defining the receiving hole in the support.

Furthermore, when both of the above-mentioned arrangements of the abutting parts are used together, it becomes easier to attach the cutting segment to the support, adapting the cutting segment to the support depending on the outer or inner configuration. becomes possible.

If the abutment parts of the cutting segments are arranged alternately on the outside and inside of the support, the cutting segments enter the receiving holes of the support in a slightly rotated position about the longitudinal axis. , and then rotates back to the final position.

In order to achieve a satisfactory connection with the support, the abutting parts of the cutting segments with grooves arranged between them are arranged on the outside of at least a part of the inner wall defining the receiving hole in the support and with the inner shaft 1. Can be placed one on top of the other. This connection mode makes it possible, in particular, to prevent detachment of the cutting segments even if the welding is not complete.

Advantageously, the groove is U-shaped in cross-section.

The U-shaped cross section may be basically angular or rounded. From the point of view of strength, grooves are generally formed with rounded edges to eliminate the effects of notch action.

Advantageously, the width of the groove corresponds approximately to the wall thickness of the support. In this case, precise guidance of the cutting segment relative to the support is possible, and furthermore, a good connection between the support and the cutting segment is achieved when the connection is reinforced by welding or the like.

It is desirable that the depth of the groove substantially match the width of the groove. In this case, good guidance of the cutting segment in the receiving hole of the support is possible.

The circumferential length of the cutting segment between the groove bottoms is
Preferably, the supporting bone corresponds to the circumferential width of the hole.

In this case, the cutting segment can be precisely positioned in the circumferential direction relative to the support. When welding the cutting segment to the support, some of the solder can be taken up by capillary action into the gap that may occur between the bottom of the receiving hole and the support.

[Best mode for carrying out the invention]

Hereinafter, the present invention will be explained in more detail with reference to illustrated embodiments.

The hollow drill tool of the present invention shown in FIG. 1 and FIG.
Tubular support 1 and cutting segment 2 connected thereto
It is equipped with The support l has a front end 1a and a rear end 1b in the pushing direction. Rear end 1b
The region of the support 1 that follows is formed as a shank for connection to a known drilling tool (not shown). A U-shaped receiving hole 1d is formed in the region of the support 1 in contact with the front end 1a in order to accommodate the cutting segment 2. Cutting segment 2
shall have edges 2a, 2b extending parallel to the longitudinal axis of the support 1 and edges 2c, 2d extending approximately perpendicular thereto. edges 2a, 2b extending parallel to the longitudinal axis of the
Grooves 2e and 2f extending in the elongated direction are formed in the grooves 2e and 2f. Similarly, a groove 2g is formed on the trailing edge 2c of the cutting segment 2 opposite to the pushing direction. Groove 2e.

2f and 2g form a contact portion 2h located on the outside and a contact portion 2i located on the inside with respect to the support 1.
to be accomplished. The width S of the grooves 2e, 2f, 2g is made approximately equal to the wall thickness W of the support l. The depth T of the grooves 2e, zr, and 2g is made approximately equal to the groove width S. The circumferential length L of the cutting segment 2 left between the bottoms of the grooves 2er H is made approximately equal to the width U of the receiving hole 1d in the support l.

Thus, when mounting the cutting segment 2 on the support l, the cutting segment is fitted with grooves 2e, 2r along the edge of the receiving hole 1d extending parallel to the longitudinal axis of the support l.
guided at the bottom of the By appropriately determining the permissible tolerances of the width S1 depth] ゛, the wall thickness W, and the width U of the receiving hole 1d in the support l, soldering is a movable part that fixes the cutting segment until welding with the support l by etc. position or locked position can be achieved. The three illustrated edges 2a,
Groove 2e on 2b and 2c.

Instead of forming grooves 2f, 2g, it is also possible, for example, to form grooves only on the edges 2a, 2b extending parallel to the longitudinal axis of the support l. In this case too, the cutting segment 2 is reliably held by the support l.

The hollow drilling tool shown in FIG. 6 comprises a support 3 with a cutting segment 4 mounted in a receiving hole 3d.

The cutting segment 4 shall have an abutment portion 4h arranged on the outside of the edges 4a, 4b extending parallel to the longitudinal axis of the hollow drilling tool. Thereby, the cutting segment 4 can be supported by the support 3 from the outside. The cutting segments 4 can be attached to the support 3 from the outside radially or axially. After the cutting segment 4 is mounted on the support 3, the cutting segment 4 is welded to the support 3 by soldering or the like. By appropriately setting the dimensions of the receiving hole 3d and the contact portion 4h, the cutting segment 4 and the support body 3 can be fitted together. Friction welding is performed by inserting it into the receiving hole 3d.

The hollow drilling tool shown in FIG. 7 comprises a tubular support 5 and a cutting segment 6 mounted in a receiving hole 5d.

The edges 6a+6b of the cutting segment 6, extending parallel to the longitudinal axis of the drill tool, are provided with abutment portions 61 arranged inside the support 5.

The abutment portion 6I enables a positive connection between the cutting segment 6 and the support 5. The contact portion 61 is supported by the support body 5 from the inside. The cutting segment 6 enlarges outwardly in the area of the receiving hole 5d, so that it cannot be installed without being inserted into the support 5 axially.

The hollow drilling tool shown in FIG. 8 comprises a support 7 and a cutting segment 8 mounted in a receiving hole 7d. The cutting segment 8 is provided with an abutment portion 8h arranged on the outside of the support 7 at an edge 8al extending parallel to the longitudinal axis of the support 7, and an abutment portion 8h located on the outside of the support 7 at an edge 8b. An abutting portion 81 located inside is provided. The cutting segment 8 is
It is supported by the support body 7 alternately from the outside and the inside via the contact portions 8h and 8i.

The cutting segment 8 is also mounted on the support 7 in the axial direction.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a hollow drill tool according to an embodiment of the present invention, FIG. 2 is a front view of the hollow drill tool shown in FIG. , Fig. 4 is a perspective view of the cutting segment shown in Fig. 3 as seen from the direction of arrow B, Fig. 5 is a plan view of the cutting segment shown in Fig. 3 as seen from the direction of arrow C, and Fig. 6 is a perspective view of the cutting segment shown in Fig. 3 as seen from the direction of arrow C. FIG. 7 is a front view of a hollow drill tool according to another embodiment of the invention; FIG. 8 is a front view of a hollow drill tool according to another embodiment of the invention; FIG. It is a diagram. ! , 3.5.7...Support 1a...Front end 1d, 3d, 5d, 7d River receiving hole 2°6°8...Cutting segment 2a. 2b. 4a. 4b. 6a. 6b. 8a. 8b...edge 2e. 2f. 2g...Groove 2h. 21°4h. 61°8h. 81...Abutting part

Claims (1)

[Claims] 1. A hollow drill tool having a tubular support (1, 3, 5, 7), wherein the support has a U-shape open toward its front end (1a). Receiving hole (1d, 3d, 5d,
7d), in which the cutting segment (2, 4, 6, 8) is at least partially held in the front end region in the pushing direction; (2h, 2i, 4h, 6i, 8h, 8i
), the corresponding contact portion being capable of radially cooperating with at least a part of the inner wall defining the receiving hole (1d, 3d, 5d, 7d) of the support (1, 3, 5, 7). A hollow drill tool characterized by: 2. The hollow drill tool according to claim 1, in which the abutting portions (2h, 2i, 4h, 6i, 8h, 8i) are parallel to the longitudinal axis of the support (1, 3, 5, 7). The edges (2a,
2b, 4a, 4b, 6a, 6b, 8a, 8b). 3. A hollow drilling tool according to claim 1 or 2, in which the abutment part (2h, 2i) is located at the trailing edge of the cutting segment (2) extending perpendicularly to the longitudinal axis of the support (1). A hollow drill tool, characterized in that the hollow drill tool is disposed in the section (2c). 4. In the hollow drill tool according to any one of claims 1 to 3, the contact portions (2h, 4h, 8h) of the cutting segments (2, 4, 8) are connected to the receiving holes (1d, 3d, 7d). )
A hollow drill tool, characterized in that the hollow drill tool is disposed overlapping the outer side of at least a part of the inner wall of the support (1, 5, 7) that defines the support body (1, 5, 7). 5. The hollow drill tool according to any one of claims 1 to 4, wherein the abutting portions (2i, 6i, 8i) of the cutting segments (2, 6, 8) are connected to the receiving holes (1d, 5d, 7d). )
A hollow drill tool, characterized in that the hollow drill tool is disposed overlapping the inner side of at least a part of the inner wall of the support (1, 5, 7) that defines the support body (1, 5, 7). 6. The hollow drill tool according to any one of claims 1 to 5, wherein the abutting portion (8h,
8i) are arranged alternately on the outside and inside of at least a part of the inner wall of the support (7) defining the receiving hole (7d). 7. The hollow drill tool according to any one of claims 1 to 6, wherein the abutting portions (2h, 2i) of the cutting segments (2) with grooves (2e, 2f, 2g) arranged between them,
A hollow drill tool, characterized in that the tool is disposed overlapping the outside and inside of at least a part of the inner wall of the support (1) that defines the receiving hole (1d). 8. The hollow drill tool according to claim 7, wherein the grooves (2e, 2f, 2g) are formed to have a U-shaped cross section. 9. The hollow drill tool according to claim 7 or 8, wherein the width (S) of the groove (2e, 2f, 2g) is determined by the width (S) of the support (1).
) A hollow drill tool characterized in that the wall thickness (W) of the hollow drill tool is approximately the same as the wall thickness (W) of the hollow drill tool. 10. The hollow drill tool according to any one of claims 7 to 9, wherein the depth (T
) is substantially the same as the width (S) of the groove (2e, 2f, 2g).