JPS59130995A - Chambering pit - 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] TECHNICAL FIELD This invention relates to a hole reaming bit.

Conventionally, after drilling a predetermined length with a constant diameter using a crown at the tip,
The blade bit was created by opening the blades to enlarge the anchoring part and forming the enlarged hole part, but with the blade bit, the bearing pressure area of the blade by the bit body is small, the cross-sectional area of the blade is small,
Due to the heavy load on the blade hinge, it was used in areas with soft ground or large boulders, and the blade was damaged when it came into contact with hard rock. In addition, in a bit with a vertically opening blade, if there are boulders mixed in the soil, the blade and boulders may rotate together, or the blade may become idle, making it impossible to expand the hole. The present invention has overcome these drawbacks by several times, and provides a hole expanding bit that eliminates the risk of co-rotation even when there are rolling stones, reduces the burden on the hinge even when the diameter expanding blade is in contact, and has fewer failures. The purpose is to provide

An embodiment 1111i of the present invention will be described with reference to the drawings. FIG. 1 shows the state of the hole-drilling bit of the present invention before operation I';! ]
shows. A blade attachment window // is opened in the length direction of the fil hole expanding bit body /. In the blade mounting window, a substantially triangular or fan-shaped diameter expanding blade 7.2 is inserted at an acute angle portion with its long side facing into the cylindrical hole drilling bit body.
3, and the tip /ll is provided inside and outside the bit body so that it can freely appear and retract downward. A driving force transmitting member 2 for transmitting rotational driving force is screwed into the tip of the bit body.

A water-conducting material passes through the diameter-expanding piston 3, and circulating water is discharged from a nozzle 33 at the tip. A drive shaft t is fixed to the other end. The drive shaft l also has a water passage hole penetrated through the shaft center.

The expanding piston 3 is housed within the bit body, and the conical surface 3/ of the expanding piston 3 and the long side of the expanding blade /! are in contact with each other, and the cutting edge/g is housed within the bit body.

A piston mount j is screwed into the distal end of the bit body, and a crown mounting part is fixed. The crown 7 is not attached to the crown attachment member B, and the crown at the tip is rotated to drill a predetermined length and a constant diameter to form a primary hole drilling portion.

The hole-expanding bit of the present invention is used to form the hole-expanding portion. When the drive shaft is depressed downward with the crown 7 reaching the hole bottom of the primary drilling section, the diameter-expanding piston 3 is moved to the piston holder 5.
Reach and stop. At this time, the diameter-expanding blade /2 comes into contact with the circumferential surface 32 of the diameter-expanding piston, and the cutting edge /l protrudes outside the bit body (FIG. 2). In this state, drive M II is rotated to make one hole.

After forming the enlarged hole part of a predetermined length, when the rod 7 connected to the IR-car shaft t and the coupler is pulled up, the diameter-expanding piston 3 rises, and the long side/end of the wide-diameter blade becomes diameter-expanded. The contact with the circumferential surface 32 of the piston is released, and the cutting edge is accommodated in the bit body by being pushed by the hole wall of the non-expanded part, and the seventh
In the state shown in the figure, the hole reaming bit is raised 1".

Note that during drilling, slime is removed by circulating water from the nozzle 33.

According to the invention, the diameter expanding blade is of the play type 1, and the long side thereof is held in the diameter expanding blade window frame with the hinge, with the cutting edge facing downward, so that the length of the hole expanding bit body and the diameter expanding blade is The bearing surface contact with the side is large, and it can be applied to large drilling failures.Since the cutting edge is flat on the bottom, the rod axial force is transmitted to the drilling ground at Tf1 contact, and the effective drilling pressure is large.
There is no danger of co-rotation even if there is a stone slab, etc. The enlarged diameter blade is supported along its entire length by the circumferential surface of the diameter enlarged piston, so there is less stress on the hinge and less stress on the 1.0 mm diameter blade. The diameter expansion blade is also small, and the diameter screw is screwed into the wedge feed by a ton, so there is no problem with the small diameter machine, and there is no failure, and the effective expansion gauge is in perfect condition. The length of the diameter expansion blade can be appropriately selected and adjusted according to the diameter expansion blade, and since the diameter expansion blade is replaced while the first guide drills the hole at the same time, the small diameter hole at the tip fulfills the principle of the guide. It is possible to prevent wobbling of the wire 11 and form a reliable hole enlarged portion.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the hole expanding bit of the present invention, in which the diameter expanding blade is in the form of a closed lug, and Figure 2 is an explanatory diagram of the hole expanding bit of the present invention.
It represents a sudden attack. Figure 53 is an explanatory diagram of the bearing pressure area between the diameter expanding blade and the hole expanding bit body. l... Cylindrical hole expanding bit body, //... Blade mounting window,
/2...Plate diameter expansion blade, /3...Bin, /Il
...Blade edge, λ...Drive force transmission part bend, 3...Diameter expansion piston, 31...Conical surface, 32...Circumferential surface, G...Drive H:
dI,! ;...Biton mount, B...crown mounting part, 7...crown, r...coupler, w...rod

Claims (1)

[Scope of Claims] / A cylindrical hole-expanding bit body with a blade mounting window opened in the length direction; A substantially triangular or sector-shaped plate diameter expansion blade with a mounting cutting edge that can freely protrude and retract from the inside and outside of the main body and a downward facing window is connected to the drive shaft and moves within the cylindrical hole expansion bit. A hole expanding bit characterized by a diameter expanding piston that allows the diameter expanding blade to open freely. ! A cylindrical hole expanding bit body with a blade mounting window opened in the length direction, and a cylindrical expanding piston on the long side. A roughly triangular or fan-shaped plate diameter expansion blade that allows light to freely enter and exit the inside and outside of the hole bit body and is installed downward in the blade mounting window, and a driving force that is fixed to the tip of the cylindrical hole expansion bit body and transmits rotational driving force. a transmission member; a drive shaft that is force-connected to the diameter-expanding piston and moves the diameter-expanding piston and transmits rotational driving force to the cylindrical hole-expanding member; a diameter-expanding piston that moves within the body of the cylindrical hole-expanding bit; A hole expanding bit comprising: a piston mount fixed to the distal end of the bit body; a crown mounting member connected to the distal end of the cylindrical hole expanding bit body; and a crown attached to the crown mounting member.