JPS61270001A - Tool for manufacturing boring hole undercut - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a tool for producing undercut boreholes, which has a shank, the forward end of which has an axially projecting main body. a secondary blade supporting the cutting blade and having a rearward end configured for insertion into a tool receptacle of a rotary percussion drive machine; A shank having a cutting edge, the minor cutting edge having a cutting edge body with a cutting edge on the end face side, and the cutting edge body extending at an acute angle with respect to the main cutting edge axis. It is held movably in the '1411 direction in the inner guide hole, and is further equipped with a striking rod that transmits the interlocking impact of the driving machine to the main body and also pushes out the auxiliary cutting edge. The shank is guided so as to be movable in the axial direction in an axially central hole extending from the shank end to near the main cutting edge in the shank, and is configured to protrude over the shank end when the auxiliary cutting edge is pushed in. Concerning things of the form .

The aforementioned undercut mailing holes, i.e. boreholes enlarged in a section between drilling directions in walls, brickwork and the like, accept locking or undercutting in the fixing technique; or required to receive a concreted fixed anchor. Holding paulownia or undercut housing is a tree that, after being introduced into the borehole, expands the key, for example by tightening a screw, and supports this key against the undercut edge of the borehole. be. In the case of the fixed anchor, undercut holes create an engagement between the brickwork and the mortar. This is because the mortar also reaches behind the undercut shoulder and is thereby prevented from leaving the borehole.

PRIOR ART Known drilling tools for producing undercut holes of the type mentioned above include a major cutting edge and a minor cutting edge housed in a cutting body; has a significantly larger diameter than the tool shank. The auxiliary cutting edge has two auxiliary cutting edge bodies each having a cutting edge on the end face side, and each of these auxiliary cutting edge bodies is movably held in one guide hole. The guide hole extends at an acute angle to the main cutting axis and opens into a central hole that receives the striking rod in the shank. The motion of the striking rod driven in the axial direction by the driving machine is transmitted to the auxiliary cutting blade body by using a peripheral surface that extends at an acute angle to the central hole and is in contact with the end side of the auxiliary cutting blade body. This is done via a clutch member.

With this construction of known drilling tools, in addition to the main cutting edge, the auxiliary cutting edge is also subjected to rotational and percussion movements by the drive machine, so that the borehole can be machined in a rotary percussion manner both axially and radially. reactor. As a result, the rotational and percussive movements of the drive machine are also used for undercutting, so that relatively wide undercut boreholes can be produced even in hard rocks.

Problems to be Solved by the Invention The auxiliary cutting edge of the known construction requires a comparatively thick cutting blade spatula P, whereby the width cutting blade main body is guided sufficiently reliably even in the extruded state. With such drilling tools, therefore, only undercut drilling holes with relatively large diameters can be produced.

Means for Solving the Problems The solution to the above-mentioned problems has been taken for a long time, in that the guide hole of the cutter body extends over the entire compensation cross section of the shank, and the axial length of the cutter body is , which is longer than the axial length of the guide hole, and further has a striking rod that engages directly into the cutting blade body and extends substantially perpendicularly to the axis of the cutting blade body on the end face side. It has a impact deflection surface which cooperates with a impact receiving surface on the cutting blade body which is parallel to the impact deflection surface.

Effects of the invention The tool of the invention is particularly suitable for small bit diameters or mailing hole diameters.

Due to the fact that the cutting edge body is guided over the entire collapsed cross section of the shank, the secondary cutting edge is still well guided even in the extruded state, especially if the shank diameter is small and the main cutting edge is small. can receive forces consisting of rock crushing, feeding motion and rotational motion acting on the

In the case of a pushed-in minor cutting edge, the cutting edge is located inside the cross-section of the polling hole formed by the main cutting edge. In the case of the extruded auxiliary cutting edge, the end opposite to the tip of the cutting blade body is located inside the cross section of the &-IJing hole,
In addition, the guide opening is prevented from entering dust. To drill the basic hole, the secondary cutting edge must be rendered inactive. This can be done by means of a suitable configuration of the drive machine, such that the percussion movement of the drive machine is transmitted only to the shank end, or simultaneously to the shank end and the percussion rod end, or by removing the percussion rod. It will be done.

Embodiment With the embodiment according to claim 2, the auxiliary cutting edge-pushing device can reliably move the drilling tool away from the four cooling holes again.

The auxiliary cutting edge-indentation device is implemented particularly advantageously by the embodiment according to claim 3.

In this case, when pulling out, the end of the cutting blade body opposite to the cutting edge first collides with the undercut edge of the polling hole, and as a result, the auxiliary cutting blade releases the spring force of the striking rod-return spring. After overcoming, it is pushed out or pulled out again. The rear end of the cutting body is thereby guided through the basic bore.

Then, when the extruded secondary cutting edge abuts the undercut edge of the poling hole near the cutting edge, □ the other end of the cutting blade body has already left the basic hole, so that the secondary cutting edge-pushing device is activated again. I can do it.

By means of the return spring and the connection of the auxiliary cutting edge with the striking rod, the cutting edge is brought back into the cross-sectional area of the main cutting edge and the drilling tool can be completely removed from the drilling hole.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The tool for producing the undercut poling hole, shown in longitudinal section in FIG. 1 and in side view in FIG. Specified for use with hole drilling machines. The drilling tool has a shank 10, the front end of which supports an axially projecting main cutting edge 11. At the rear end of the shank remote from the main cutting edge 11, the shank 10 is designed as an end section 12 for insertion into a tool receptacle of a rotary percussion drive machine, not shown here. The main cutting edge 11 forms a basic hole in the axial direction, and a delivery member 13 extending spirally around the shank circumferential surface carries out the shavings by making the hole.

For undercut drilling, a minor cutting edge 14 can be moved laterally behind the main cutting edge 11. The auxiliary cutting edge 14 consists of a blade body 15 and a cutting edge 16 disposed on the end side of the blade body 15. The blade body 15 has a shank 1o
extending at an acute angle with respect to the main cutting edge axis 17 that overlaps with the axis of
It is held adjustable in the axial direction within a guide hole 18 in the shank 10. As can be seen from FIGS. 1 to 3, the guide hole 18 passes through the entire cross section of the shank. The guide hole 18 is penetrated within the shank 10 by an axial central hole 19 that extends from the shank end to near the main cutting edge 110 . The cutting blade body 15 that slides within the guide hole 18 is designed to be longer than the guide hole 18 in its axial length, so that the secondary cutting edge overflows as the cutting blade body 15 moves through the central hole 19. 14, it is reliably guided within the guide hole 18.

A striking S keyaki 20 is guided so as to be movable in the axial direction within the central hole 19, one end of the striking rod engages with the cutting blade main body 15, and the other end pushes the auxiliary cutting blade 14. Musani main cutting edge 1
1 projecting beyond the opposite shank end. As can be seen in particular from FIGS. 3 and 4, the rounded front end region 21 of the striking rod 20, which engages in the cutting body 15, is chamfered and at an angle to the shank axis on the end side. It supports protrusions 22 that protrude on both sides, and the front side of the protrusions forms an impact deflection surface 23. Impact deflection surface 23
The cutting blade body 1 extends substantially perpendicularly to the axis 24 of the cutting blade body 15 and is parallel to the impact deflection surface.
It cooperates with the impact receiving surface 25 at 5.

The impact receiving surface 25 defines an axial slit 26 in the cutting body 15, which extends from the end of the cutting body 15 opposite the cutting edge 16 to approximately the center of the cutting blade body 15. It extends and ends in a notch 27 corresponding to the raised part 22. The raised part 22 and the notch part 27 are
The striking rods 20 are fitted together so as to engage within the cutting body 15, in which case the striking deflection surface 23 of the striking rods 20
and the impact-receiving surface 25 of the cutting blade body 15 are in contact with each other, forming a connection between the striking rod and the cutting blade body 15 that operates during the reciprocating movement of the impact rod 20. The above-mentioned mating connection forms a auxiliary cutting edge-pushing device 29 associated with a striking rod-return spring 28, which is supported on the shank 10 on one side and on the striking rod 20 on the other side. After the auxiliary cutting edge 14 is pushed out by this auxiliary cutting edge-pushing device by feeding the striking rod 20 in the axial direction (Fig. 2), the auxiliary cutting edge is removed by removing the impact load of the striking rod 20. The blade 14 is pushed in again (FIG. 1). The extruded length of this rough auxiliary cutting edge 14 is such that the striking rod 20 exceeds the shank end when pushing the auxiliary cutting edge 14: In order to make a basic hole with the main cutting edge 11, The striking rod 20 is inactive, so that the auxiliary cutting edge 14 is in the pushed-in position shown in FIG. The striking rod is carried out, for example, by a suitable device in a rotary percussion drive machine, so that during drilling of the basic hole the striking movement of the drive machine is transmitted only to the annular edge of the shank end, but not to the striking rod 20. Not done. The impact of a driving machine, for example a rock drill, is transmitted via the shank 10 to the main cutting edge 11 . The basic hole is rotary percussion machined in the axial direction, and a cylindrical seven-drill hole is formed with a diameter defined by the diameter of the main cutting edge 11.

When the rear end of the cutting body 15 of the auxiliary cutting edge 14, opposite the cutting edge 16, rests against the hole wall, the striking rod 20 is again active, so that the striking rod is now also subject to the striking movement of the drive machine. is affected. During each impact load, the hammer 20 moves the cutting body 15 into the guide hole 18, so that the cutting edge 16 projects from the shank 10. The ball hit by the driving machine, which is applied to the hitting rod 20, hits the cutting edge 1 via the hitting deflecting surface 23 of the hitting rod zO and the hitting receiving surface 25 of the cutting blade body 15.
6 and the now undercut north section is machined.

In the case of the extruded auxiliary cutting edge 14 (No. 2: 4゜, the end of the cutting blade main body 15 opposite to the cutting edge 16 is provided inside the basic hole diameter. In the case of forming, depending on the instantaneous axial position of the striking rod 20 when the drilling tool is rotated, either the striking rod 20 or the shank 10, or both, are struck by a two-stroke hammer of the drive machine. Such striking positions are released very quickly and alternately in the rhythm of the piston frequency of the striking piston,
In this case, many intermediate positions still occur. By such a striking action which is superimposed with the continuous rotational movement of the hole-making tool, the rock is machined in a rotary striking manner both by the main cutting edge 11 and by the auxiliary cutting edge 14.

After completing an undercut hole of a desired depth, the drilling tool can be moved away from the undercut hole without any problems by means of a predetermined auxiliary cutting edge-pushing device. When the hole-making tool is pulled out, when the rear end of the cutting blade body 15 opposite to the cutting edge 16 comes into contact with the undercut la, the cutting blade body 15 is moved by the striking rod - when the hole-making tool is further pulled out. After overcoming the spring force of the return spring 28, it is pushed out again. As a result of this, the rear end of the cutting body 15 is again located inside the basic hole diameter and guided through the basic hole. When pulling out the hole-making tool, the edge of the extruded cutting blade body 15 on the cutting edge side collides with the undercut edge of the hole. However, at this moment, the rear end of the cutting blade body 15 Haste IF-+
7 outside the ring hole, and this makes the minor cutting edge -
The pushing device can be operated freely. As a result, the auxiliary cutting edge 14 is pushed in again and the drilling tool is completely moved away from the sailing hole.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a tool specified for use in a winding machine to create undercut poling holes with the auxiliary cutting edge pushed in, and Figure 2 is the same as Figure 1. FIG. 3 is an enlarged view of part A of the tool according to FIG. 1, and FIG. FIG. 3 is an enlarged view of the tool in the figure in the direction of arrow B; DESCRIPTION OF SYMBOLS 10... Shank, 11... Main cutting edge, 12... End section, 13... Carrying out member, 14... Minor cutting edge, 15
...Blade body, 16...Blade tip, 17...Main cutting edge axis, 18...Guide hole, 19...Central hole, 20...Running bale, 21...Front end Range, 22... Prominence, 2
3... Impact deflection surface, 24... Axis line, 25... Impact receiving surface, 26... Slit, 27... Notch portion, 2
8...Blow rod-return spring, 29...Jll cutting blade-pushing device 10...Shank 11...Main cutting blade
14... Minor cutting edge 10... Shank 14... Minor cutting edge 15... Cutting blade body Fig, 3

Claims (1)

[Claims] 1. A tool for making an undercut borehole, which has a shank, the front end of the shank supporting a main cutting edge that projects in the axial direction, and a rearward end configured for insertion into a tool receptacle of a rotary percussion drive machine; further rearward of the main cutting edge;
It has a secondary cutting edge that is pushed out laterally, the secondary cutting edge has a cutting blade body with a cutting edge on the end face side, and the cutting blade body is oriented with respect to the main cutting blade axis. It is held movably in the axial direction in a guide hole in the shank that extends at an acute angle, and is further provided with a striking rod that transmits the striking motion of the driving machine to the cutting blade body and also pushes out the auxiliary cutting edge. and the striking rod is axially movably guided in an axially central hole extending from the shank end to near the main cutting edge in the shank, and when the minor cutting edge is pushed in, the shank end In the cutting blade body (15
) for the guide hole (18) extends over the entire cross section of the shank, and the axial length of the cutting blade body (15) is longer than the axial length of the guide hole (18), and The striking rod (20) is adapted to engage directly into the cutting body (15) and has a striking deflection on the end face extending approximately at right angles to the axis (24) of the cutting body (15). Face (23
), and this impact deflection surface is parallel to the impact deflection surface and is parallel to the impact receiving surface (2) of the cutting blade body (15).
5) A tool for producing undercut boreholes, characterized in that it is adapted to cooperate with. 2. The tool according to claim 1, comprising a auxiliary cutting edge-pushing device (29). 3. The sub-cutting blade-pushing device (29) is connected to the striking rod (20
) and the cutting blade body (15) acting at least towards the shank end, and a striking rod-return spring (28) supported between the shank (10) and the striking rod (20).
) The tool according to claim 2, comprising: 4. The connecting portion is formed by the engagement between the raised portion (22) of the striking rod (20) and the cutout portion (27) of the cutting blade body (15) in engagement ranges on both sides. Claim 3
Tools listed in section.