JP5443349B2 - Bit assembly - Google Patents

Description

  The present invention relates to a bit assembly in a drilling device, the device operating by striking and / or rotating the assembly, the assembly comprising a pilot bit for drilling a central portion of a hole, and the pilot bit And a ring bit having a cylindrical inner surface for drilling the outer surface of the hole, and a structure for preventing mutual rotation and axial movement between the pilot bit and the ring bit. Open the blocking arrangement so that the pilot bit can be pulled out of the hole while the ring bit remains in the hole, the bit assembly comprising the casing tube and its extension and the extension of the casing tube. To transmit traction force from pilot bit or ring bit to casing tube extension through the ring device It is in and a are linked system, if the casing tube remains in place, it is possible to open the coupling system to continue drilling in the ring bit and pilot bit.

  From WO 2004/057148 a drilling device as described above with pilot bits and ring bits has been known for some time. However, with this solution it is not possible to continue drilling so that the protective tube remains at the desired point in the drill hole.

  From WO 1996/718798 a drilling device is known in which the casing tube and the ring bit can be left in the desired position of the drill hole and drilling can be continued only with the pilot bit, ie the intermediate bit. In this solution, if the drilling is continued only with the pilot bit, the hole diameter is basically reduced. In drilling for fixation, anchor bolts or cables stick to it by continuing drilling, which makes the hole smaller. In this case, the joint surface of the fixed object is formed smaller than that expected when the diameter of the hole remains constant up to the end of the hole.

  From EP 1 447 797, a casing shoe, which is optimally fixed to the tip of the casing tube by welding, is fixed around the ring bit by contraction so that they can rotate relative to each other but are locked in the axial direction. It is known to do so. On the outer surface of the ring bit, there should be a groove for receiving the ring-shaped raised portion of the inner surface of the casing shoe. This type of groove requires that the ring mantle of the ring bit with its wall thickness be sufficient for the groove.

  From Finnish Patent Publication No. 98649 a protective tube release system is known which has a ring that can be pulled like a bayonet lock on the outer surface of the pilot bit or ring bit while pulling the casing tube. The ring has a groove on its inner surface, each with a raised portion on the outer surface of the bit to achieve interlocking. With this solution, it is difficult to create a raised portion on the surface of the cylindrical bit. For example, this solution does not utilize cleaning grooves on the pilot bit surface that is often formed. With respect to the casing tube, the tube extension is not used but the cantilevered ring is used so that the other axial direction remains unlocked. If the bit is missed inside the casing tube, the ring that pulls the casing tube cannot be returned to the locked state with the bit, so if the casing tube is left in the hole too early, it will `` find '' this again by the bit. This has difficult consequences because it cannot.

International Publication No. 57148 International Publication 1996 No. 718798 European Patent No. 1144797 Finnish Patent No. 98649

  In order to eliminate the disadvantages contained in the above-mentioned solutions and to improve the technical effects of these solutions, the ring-shaped device comprises an inwardly directed part, whereby the device is connected to a pilot bit or ring. A new bit assembly is developed that is fixed to rotate in a transverse groove on either outer surface of the bit to limit or prevent axial movement of both.

  An advantage of the present invention is that the casing tube that is pulled into the hole during drilling can be left in the desired position in the hole, sometimes without pulling the drilling device out of the hole, for example when hitting a rock. It can be done. Even if the pilot bit and the ring bit continue to be drilled without the casing tube, there is no change in the diameter of the drilled hole. In this solution, there is a traction system around the pilot bit that pulls the casing tube into the hole, thus saving material on ring bit parts that are often left in the finished hole. it can. If the casing tube is pulled by a pilot bit rather than a ring bit, the striking surface between the pilot bit and the ring bit can be significantly reduced relative to previous solutions, which allows the wall of the cylindrical portion of the pilot bit to The thickness can also be reduced. On the other hand, the striking surface between the ring-shaped device according to the invention and the casing tube extension can easily be increased, thereby extending the durability of the pilot bit. By advantageously locking the ring-shaped device to the outer surface of the pilot bit, it is possible to use at least part of the cleaning groove or ring bit groove on the outer surface of the pilot bit. This is possible because, according to the invention, the ring-shaped device includes a raised portion facing inwardly on its inner surface.

  Hereinafter, the present invention will be disclosed more closely with reference to the accompanying drawings.

It is a figure which shows the pilot bit of a drill apparatus diagonally. It is a figure which shows the pilot bit of the drill apparatus which fitted the ring bit. It is a figure which shows the drill apparatus which engage | inserted the ring-shaped apparatus which transmits tractive force to a casing tube in the pilot bit. It is a figure which shows the bit assembly of a drill apparatus. It is a figure which shows the components of the bit assembly loosened.

  FIG. 1 shows a pilot bit 1, which comprises a stem 13, a striking surface 14 with a bit button, and a cylindrical part 16, which is shallower than the cleaning groove 12 and this. It has a vertical groove for locking such as the groove 17 and a horizontal groove 10 for locking. The tip of the cylindrical portion 16 is a smaller cylindrical portion with respect to its diameter. The drill scrap cleaning groove 12 is deeper than the vertical groove on the pilot bit surface.

  FIG. 2 shows the ring bit 2 placed in place around the pilot bit 1. The portions such as the locking claws 7 and 15 lock the bits 1 and 2 so that they cannot rotate in one rotational direction and cannot move in both axial directions.

FIG. 3 shows a ring-shaped device 8 which is arranged around the pilot bit 1 and transmits the striking force or traction force to the casing tube. On the outer surface of the pilot bit, longitudinal shallow grooves 17, and there are also lateral grooves 10 emanating therefrom. The inner surface of the ring-shaped device 8 belongs inner surface projecting portion 9, which is fixed to fit into the longitudinal groove 17, also by being further secured strikes the lateral grooves 10, the ring-shaped device 8 pilot bits 1 It adheres like a bayonet bond around. Therefore, the ring-shaped device 8 can be removed from above the pilot bit 1.

FIG. 4 shows a cross-sectional view of the casing extension 6 to be welded to the end of the casing tube, which is fixed around the ring-like device , for example by shrink fitting. The shrink joint is left loose so that the parts can rotate together. However, although they are axially locked together, they leave a small mutual gap of 5-10 mm in the axial direction. Although the casing tube is not shown, it is fixed by a known method, for example , by welding and fixing to the extension 6.

FIG. 5 shows a loosened component according to the invented structure. Due to the inner projecting part 9 of the ring-like device 8, there is a groove 10 on the cylindrical part of the pilot bit 1 and one can screw the part 9 into this groove by a small rotational movement. The pilot bit 1 can be passed through the ring-shaped device 8 in both directions. If the casing tube containing the extension 6 remains in the hole, the ring bit 2 should always remain in the end hole.

  In the drawing, a configuration in which the casing tube is pulled from the pilot bit 1 to the extension portion 6 of the casing tube by the ring-shaped device 8 is shown. The pull can also be configured from the outer surface of the ring bit 2 to the extension 6 of the casing tube by means of the ring-shaped device 8.

DESCRIPTION OF SYMBOLS 1 Pilot bit 2 Ring bit 6 Extension part 7 Locking claw 8 Ring-shaped device 9 Inner surface protruding part 10 Horizontal groove 11 Ring-shaped groove 12 Cleaning groove 13 Stem 15 Locking claw 17 Longitudinal connection groove

Claims (3)

A bit assembly in a drilling device,
The apparatus lashed the assembly, and / or operates by rotating the assembly,
The assembly is
A pilot bit (1) for drilling the central part of the hole;
A ring bit (2) having a cylindrical inner surface that is fixed in connection with the pilot bit (1) and that pierces the outer surface of the hole ;
An inter-rotation and axial movement blocking arrangement between the pilot bit (1) and the ring bit (2) , whereby the blocking arrangement can be opened to pull the pilot bit (1) out of the hole While the ring bit (2) remains in the hole,
The bit assembly includes:
Casing tube, and, the extension of the casing tube (6),
The pilot bit via the ring-shaped device (8) from the extension (6) of the casing tube, or, and a coupling system adapted to transmit the traction force from the ring bit in the extension of the casing tube (6) ,
If the casing tube remains in place, the connection system can be opened to continue drilling with the ring bit (2) and the pilot bit (1) ;
With the ring-shaped device (8) is the inner surface projecting portions directed inwardly (9), thereby rotating the device to a lateral groove (10) in on one of the outer surface of the pilot bit or the ring bit So as to limit or prevent axial movement of both of them,
When the ring-shaped device (8) is fixed in a ring-shaped groove (11) belonging to the inner surface of the extension (6), it is locked in the axial direction in the extension (6) of the casing tube. The ring-shaped device (8) is configured to be rotatable within the extension,
The extension (6) of the casing tube with the ring-shaped groove (11) is fastened around the ring-shaped device (8) by shrink fitting so that these parts can rotate relative to each other. The shrink joint is left loose and
The pilot bit (1) or the ring bit (2) can be separated from the ring-shaped device (8) by reciprocal rotation and become ready to pass through the device.
A bit assembly characterized by that. The ring-shaped device (8) is fixed in a lateral and terminating groove (10) in the outer surface of the pilot bit (1) in a manner such as a bayonet bond;
The bit assembly according to claim 1. The longitudinal cleaning grooves on the surface of the pilot bit (1) (12), longitudinal connecting grooves on the surface of the pilot bit (17), and deeper than the transverse groove (10),
The bit assembly according to claim 1.

Images