WO1997048875A1

WO1997048875A1 - Down-the-hole hammer

Info

Publication number: WO1997048875A1
Application number: PCT/JP1997/002089
Authority: WO
Inventors: Akira Nakayama; Makoto Kobayashi
Original assignee: Suntech Corporation
Priority date: 1996-06-19
Filing date: 1997-06-18
Publication date: 1997-12-24
Also published as: EP0851090A4; KR100205470B1; AU3274197A; JPH108869A; AU719282B2; EP0851090A1

Abstract

A down-the-hole hammer in which a top sub connected to a joint adapter is connected to the upper end of a piston-containing piston case and a driver thumb in which a hammer bit is housed movably to and fro is connected to the lower end of the piston case, characterized in that there is no possibility that the connected members are loosened even when they are turned forward or reversely, the connecting and disconnecting of parts can be done simply without using any special jig and tool during part replacement. A joint adapter (18) and a top sub (17) are formed to one body. The coupling of the piston case (1) and the top sub (17) together and the coupling of the piston case (1) and the drive sub (5) together are done by engaging the joint portions of the top sub (17) and drive sub (5) formed into polygonal shafts (19) or spline shafts with the joint portions of the piston case (1) formed into recesses (20) into which these polygonal shafts (19) or spline shafts are fitted. Pins (22), which serve as keys, are removably inserted into pin holes formed in boundary parts between these engaged joint portions so that the pin holes (21) extend over both of the joint portions.

Description

Description Down-the-hole hammer Technical field

TECHNICAL FIELD The present invention relates to a down-the-hole hammer for excavating a hole for a pile as a foundation work in the fields of construction and civil engineering. Background art

As is well known, a down-the-hole hammer moves a hammer up and down by the movement of a piston and excavates by hitting.This configuration is shown in Figs. 15 and 16, where 1 has a built-in piston 2 A piston case 3 is a hammer bit, and a drive sub 5 that accommodates the upper part of the hammer bit 3 so as to be able to move forward and backward is connected to the lower end of the piston case 1 with a screw structure.

The center portion of the hammer bit 3 is formed as a spline shaft, which fits into the inside of the drive sub 5 having an uneven groove on the inner peripheral wall. In the figure, reference numeral 6 denotes a foot valve, 7 denotes a ォ (リティ) ring, 8 denotes a bit retainer ring, and 9 denotes a piston tonality ring.

At the upper part of the piston 2, a rigid valve 11 holding a choke 14 at the center, a make-up ring 12, a valve guide 13, a valve spring 15, and a check valve 16 are arranged with an O-ring 10 interposed therebetween. Screw the top sub 17 that forms the valve seat of the check valve 16 into the upper part of the piston case 1.

Ό.

The top sub 17 has a frusto-conical screw hole in the center, and the frusto-conical screw formed at the bottom of the joint adapter 18 for connection to the auger shaft is used here. Screwed. '

In this way, the joint adapter 18 and the top sub 17, the top sub 17 and the piston case 1, the piston case 1 and the drive sub 5 are joined by screws.

The down-the-hole hammer is connected to the tip of an auger shaft such as a screw shaft as an excavator via the joint adapter 18, and excavates the ground while rotating with the auger shaft.

This rotation is mainly for clockwise excavation, and in the softer stratum, earth pressure is applied to the excavator's peripheral surface, so the outer periphery of the down-the-hole hammer may be held down. In such a situation, the left and right rotations are repeated not only to the right but also to the left to reduce friction on the outer periphery.

If the left rotation is adopted, there is a possibility that the parts joined by the screws are loosened and separated from each other.

On the other hand, if clockwise turning is continued for a long time, the screw will be too hard, and if the hammer bit 3 is replaced on site, it will not be possible without a special jig. For this reason, special removal and mounting jigs (hydraulic chuck device, etc.) are required, and replacement at the site is not possible.

An object of the present invention is to solve the above-mentioned disadvantages of the conventional example, and there is no possibility that the members are loosened even when the components are rotated forward and backward, and the components can be easily connected to each other without using a special jig when replacing the components. · To provide a down-the-hole hammer capable of withdrawal. Disclosure of the invention

To achieve the above object, the present invention firstly provides a screw with a built-in piston. The top sub that connects to the joint adapter is attached to the upper end of the ton case, and the hammer bit is retractably stored at the lower end. Formed as an integral body, the connection between the piston case and the top sub and the connection between the piston case and the drive sub are made by connecting the connection part of the top sub or the drive sub to a polygonal shaft or a spline shaft, and connecting the piston case to the drive sub. The connecting portion is a concave portion into which these polygonal shafts or spline shafts are to be fitted. The key point is that the key pin can be freely inserted and removed.

Secondly, the pin hole should be formed in the horizontal direction. Thirdly, a stop ring should be placed before and after the inserted pin to prevent the pin from falling off, or by the side of the inserted pin to prevent the pin from falling off. Fourth, pin holes are formed in parallel with the upper and lower tiers, forming a total of four pin holes, and locking with a total of four pins that enter this hole The gist of this is.

According to the first aspect of the present invention, since the tob sub connected to the joint adapter is formed as an integral body, there is no danger of loosening due to the screw connection as in the related art. The connection between the case and the top sub and the connection between the piston case and the drive sub are arranged so that the polygonal shaft or the spline shaft fits into the corresponding concave portion, and straddles both at the boundary of this fitting. Since the pin hole to be provided and the pin serving as the key are engaged with each other, there is no danger of loosening due to the screw connection as in the related art.

Furthermore, when exchanging parts, if the pin is pulled out from the pin hole, the polygonal shaft or spline shaft fitted into the recess can be pulled out without any change. According to the present invention as set forth in claim 2, the pin hole is formed in a horizontal direction, and the pin serves as a key, in addition to the above-described operation. Since the pins are also inserted in the horizontal direction, the members can be securely and firmly locked in the horizontal direction by effectively utilizing the length of the pins.

According to the third aspect of the present invention, it is possible to easily prevent the pin from falling off by the stop ring, and according to the fourth aspect of the present invention, a stop bolt is provided on the side of the inserted pin. The pin can be easily prevented from falling by pressing the tip.

According to the fifth aspect of the present invention, the locking is performed by a total of four pins arranged in the upper and lower stages, so that more secure and strong locking can be achieved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partially cutaway front view showing a down-the-hole hammer according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a cross-sectional plan view showing another example of the connection between the top sub and the piston case.

FIG. 5 is a cross-sectional plan view showing another example of the connection between the drive sub and the piston case.

FIG. 6 is a vertical sectional side view when a hammer cover is provided.

FIG. 7 is a sectional view taken along the line CC of FIG.

FIG. 8 is a plan view of a pin used in the first embodiment.

FIG. 9 is a plan view of the stopping ring used in the first embodiment. FIG. 10 is a plan view of a pin used in the second embodiment.

FIG. 11 is a cross-sectional plan view of a main part showing a second embodiment.

FIG. 12 is a plan view of a pin used in the third embodiment.

FIG. 13 is a cross-sectional plan view of a main part showing the third embodiment.

FIG. 14 is a vertical sectional side view of a main part showing the fourth embodiment.

FIG. 15 is a vertical side view of a conventional down-the-hole hammer. FIG. 16 is an exploded perspective view of a conventional down-the-hole hammer. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially cutaway front view showing a down-the-hole hammer according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. The same components as in FIGS. 15 and 16 showing the conventional example are denoted by the same reference numerals.

The down-the-hole hammer of the present invention also has a built-in piston as in the past. Drive sub 5 is connected.

First, in the present invention, the joint adapter 18 for connecting to the auger shaft and the top sub 17 are formed as one body.

The connecting portion (joint) of the top sub 17 is formed as a polygonal shaft 19 (in the illustrated example, a hexagonal shaft), and the connection portion of the piston case 1 is set so that the polygonal shaft 19 fits therein. It is configured as a polygonal concave portion 20 corresponding to this. In the figure, reference numeral 35 denotes an O-ring as a seal disposed below the polygon shaft 19 of the top sub 17.

Further, the polygonal shaft 19 and the recess 20 are respectively provided at the boundary portions of this fitting. A groove having a semicircular cross section is formed in the horizontal direction, and a circular pin hole 21 is formed in the horizontal direction so as to extend over both the top sub 17 and the biston case 1 by combining these two grooves.

The pin hole 21 is open to the outside, and a pin 22 serving as a key is inserted into the pin hole 21 through the opening so as to be freely inserted and removed.

A groove is cut in the circumferential direction of the hole at the front and rear positions of the inserted pin 22, and a stop ring 23 for fitting the outer peripheral edge into the groove is arranged to prevent the pin 22 from coming off. Fig. 8 and Fig. 9 show the pin 22 and the stop ring 23.The pin 22 has no head at both ends, and the stop ring 23 can be reduced in diameter with a partially cut-out shape. Donut-shaped ring o

The connection (joint) at the top of the drive sub 5 is also formed as a polygonal shaft 19 (in the example shown, a hexagonal shaft), and the connection on the piston case 1 side is inserted so that the polygonal shaft 19 fits into it. The same circular pin hole 21 is formed in the horizontal direction at the boundary between the fitting of the two, and a key pin 22 serving as a key can be freely inserted and removed in the pin hole 21. Shall be inserted. In addition, stop rings 23 for preventing slipping out are arranged at the front and rear positions of the inserted pins 22. In the figure, reference numeral 33 denotes a packing, and reference numeral 34 denotes a bit receiving ring formed by collecting two half-split members to form a ring.

The connection between the drive sub 5 and the hammer bit 3 is the same as before, and the center of the hammer bit 3 is formed as a spline shaft, and the drive sub 5 has a concave and convex groove for engagement on the inner peripheral wall. 5 is fitted into the concave portion 24. In this way, the top sub 17 and the biston case 1 and the biston case 1 and the drive sub 5 are joined together by fitting the polygonal shaft 19 and the corresponding polygonal recess 20 to both the left and right rotations. The detachment is prevented by the pin 22, which is a key and is key. In order to separate them by exchanging parts or the like, the pin 22 can be pulled out by removing the stop ring 23. The pin 22 is then pulled out, and the top sub 17 and the drive sub If you remove the polygonal shaft 19 of 5, you can easily remove it.

The connecting portion (joint) of the top sub 17 and the drive sub 5 is formed as a spline shaft 25 as shown in FIGS. 4 and 5 instead of a polygonal shaft. A spline groove may be formed for fitting.

Further, as a second embodiment of the present invention, in order to prevent the pin 22 from dropping off, the pin 22 has a head 22a as shown in FIGS. A recess 22b having a flat contact surface was formed in the portion. Then, a stop bolt 27 is inserted from the outside, and its tip is pressed into the recess 22b. As a third embodiment of the present invention, as shown in FIGS. 12 and 13, a pin 22 of a type commonly used in an earth auger or the like in which a panel steel 32 is interposed in a head 22a is used. It may be.

In the above embodiment, the pin holes 21 are a pair of left and right parallels. However, as a fourth embodiment of the present invention, the pin holes 21 are a pair of left and right parallels as shown in FIG. It is also possible to form a total of four pins in the upper and lower rows so that the upper and lower rows are orthogonal to each other, and lock them with a total of four pins 22 inserted here. ,.

Locking with such a large number of pins 22 enables more secure and strong locking.

FIG. 6 shows a case in which the hammer cover 28 is put on the down-the-hole hammer of the present invention. The screw shaft 31 as one form is located. A vertical ridge 30 is suitable for this hammer cover 28. The hammer cover 28 is formed at an appropriate interval to secure a groove in the vertical direction, so that an air gap can be secured around the outer periphery of the rotating hammer cover 28. In addition, as an excavator, there is a ground auger type in which the driving device moves up and down along the leader mast, and a type in which the rod itself is slid while the outer periphery of the mouth is checked by the driving device. Therefore, instead of the upper casing 29 or the screw shaft 31, the auger shaft can be connected to the upper part of the down-the-hole hammer and used as a clutch to rotate and drive this. It is. Industrial applicability

As described above, with the down-the-hole hammer of the present invention, there is no danger that the connection of the members will be loosened even when rotated forward and backward, and the components can be easily connected and disconnected without using a special jig when replacing the components. You can do it.

Claims

The scope of the claims

1. Connect the top sub (17) connected to the joint adapter (18) to the upper end of the piston case (1) that houses the piston, and drive the sub (5) that houses the hammer bit (3) at the lower end so that it can move forward and backward. In the down-the-hole hammer, the joint adapter (18) and the top sub (17 are formed as one piece, and the piston case (1) and the top sub (Π) are connected, and the piston case (1) and the drive sub are connected. For connection with (5), use the polygonal shaft (19) or spline (25) shaft as the connection part for the top sub (17) or drive sub (5), and connect the connection part for the biston case (1). Are fitted as recesses (20) into which these polygonal shafts (19) or spline shafts (25) are fitted, and a pin hole ( 21) Shape Down-the-hole hammer, and which is characterized in that connecting or disconnecting freely inserts the key pin (22) into the pin hole (21).

2. The down-the-hole hammer according to claim 1, wherein the pin hole (21) is formed in a horizontal direction.

3. A stop ring (23) is arranged before and after the inserted pin (22) to prevent the pin from falling off, as described in any one of claims 1 and 2 above. Down the hole hammer.

4. To prevent the pin (22) from dropping, press the tip of the stop bolt (27) against the side of the inserted pin (22). Crab down haul hammer.

5. The pin hole (21) is formed in two sets of four parallel in the upper and lower stages, and is locked by four pins (22) inserted in the set. Item 5. The down-the-hole hammer according to any one of Items 4 to 4.