JPH02104897A - Shank rod holder for rock drill - Google Patents

Abstract

PURPOSE:To give a proper propulsive force to rod and bit even when the weights of rod and bit are overmuch by a method in which a holder piston to keep a shank rod on a striking position and a buffer to allow displacement by striking of shank rod are provided. CONSTITUTION:In the case of drilling downwardly long holes, an oil pressure enough to support the weights of rod 6 and bit 7 is supplied to a pressure chamber 12, and a holder piston 11 is pushed up to keep a shank rod 5 on a striking position where striking is given by collision of a strike piston 9. An impact is given in the chamber 12 through the piston 11 from the rod 5 by striking of the piston 9, but since the impact is buffered by an accumulator 15, the forward displacement of the rod 5 by the impact is allowed and the striking force is effectively transmitted from the shank rod 5 to the rod 6 and the bit 7. The effect of the weights of the rod 6 and the bit 7 on propulsion can thus be eliminated and proper propulsive forces can always be given to the rod 6 by sending the rock drill 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shank rod holding device for a rock drill for drilling downward long holes.

[Prior Art] Generally, as shown in FIG. 2, a drilling device has a boom 2 whose base end is pivoted on a cart 1, and a guide shell 4 on which a rock drill 3 is mounted at the other end of the boom 2. is supported. A rod 6 and a bit 7 are connected to the shank rod 5 of the rock drill 3, and the rock drill 3 applies impact and rotation to the rod 6 and bit 7. ) to feed the carriage 8 to which the rock drill 3 is attached to drill a hole.

[Problem to be solved by the invention]

When drilling a hole, the rod 6 is moved by the feed of the rock drill 3.
If the thrust applied to the bit 7 is too small, the drilling speed will decrease; if it is too large, the rotational resistance of the bit 7 will increase, making drilling impossible. Therefore, in order to improve the drilling efficiency, the thrust applied to the rod 6 , it is necessary to apply an appropriate thrust to bit 7.

Therefore, when drilling downward, when the length of the rod 6 is short, an appropriate thrust can be applied to the bit 7 by the feed given by the feed device to the rock drill 3, as shown in Fig. 3. In this way, the shank rod 5 can be held at a striking position where the tip of the striking piston 9 of the rock drill 3 collides with the rear end face of the shank rod 5 to deliver a striking blow.

However, when the length of the hole is increased by downward drilling, the weight increases as the length of the connected rod 6 increases, and the rotational resistance of the bit 6 and rod 7 increases, reducing the drilling efficiency. If the diameter is large, it will soon become impossible to drill a hole. Therefore, when drilling with the rock drill 3 lifted to reduce rotational resistance, the shank rod 5 pulls out forward (up and down in the figure) and separates from the striking piston 9, as shown in FIG. This results in a dry striking position, and sufficient striking force cannot be applied from the striking piston 8 to the shank rod 5.

This invention solves the above-mentioned problems of rock drilling machines for drilling downward long holes, and even when the weight of the rod 6 and the bit 7 is excessive, the rod 6 and the bit 7 are provided with an appropriate thrust. It is an object of the present invention to provide a shank rod holding device for a rock drill that can effectively transmit the striking force of a striking piston 9 to a rod 6 and a bit 7.

[Means for Solving the Problems] In order to solve the above problems, the shank rod holding device of the present invention includes a holder piston that holds the shank rod in a striking position in a rock drill for drilling downward long holes;
The shank rod is provided with a buffer means for allowing displacement due to impact of the shank rod.

[Effect]

When drilling a downward elongated hole, the shank rod holding device of this rock drill holds the shank rod in a rear striking position with a holder piston, and allows displacement of the shank rod due to the striking γ by a buffer means. Therefore, even if the rod and bit are heavy, the striking force of the striking piston of the rock drill can be effectively transmitted to the rod and bit, and an appropriate thrust can be applied by the feeding device.

〔Example〕

Examples will be described with reference to the drawings.

FIG. 1 is a diagram showing the structure of the shank rod holding device of the rock drill of the present invention, in which the rock drill 3 has a built-in striking piston 9 like the known rock drill. This striking piston 9 reciprocates and strikes the shank rod 5 mounted at the front. A rod 6 and a bit 7 are connected to the shank rod 5. A shank rod holding device 10 is provided in front of the rock drill 3 attached to the carriage 8. Shank rod holding device 10
is equipped with a holder piston 11 and a pressure chamber 12,
The holder piston 11 pushes up the stepped portion 13 of the shank rod 5 due to the hydraulic pressure in the pressure chamber 12, and the shank rod 5
Holding in striking position. The pressure chamber 12 is connected to a hydraulic power source (not shown) via a pipe line 14.
An accumulator 15 is connected near the pressure chamber 12 population.

When drilling downward long holes, the pressure chamber 12 is equipped with a rod 6,
Hydraulic pressure capable of supporting the weight of the bit 7 is supplied, the holder piston 11 is pushed up, and the shank rod 5 is held at a striking position where the striking piston 9 collides with it to give a strike. Due to the impact of the impact piston 9, a shock is applied from the shank rod 5 to the pressure chamber 12 via the holder piston.
Since this impact is buffered by the accumulator 15, the shank loft 5 is allowed to be displaced forward by the impact. Therefore, the striking force is from the shank rod 5 to the rod 6.
, effectively transmitted to bit 7. rod 6, bit 7
The weight is supported by the shank rod holding device 10 as described above, but this weight increases as the rods 6 are connected, so it is desirable to increase the oil pressure supplied to the pressure chamber 12 as the rods 6 are connected. . This eliminates the influence of the weight of the rod 6 and bit 7 on the thrust,
By feeding the rock drill 3, an appropriate thrust can always be applied to the rod 6, and the drilling efficiency will not decrease due to an increase in the rotational resistance of the bit 7. Note that the step portion 13 of the shank rod 5 may be used as a buffering means instead of the accumulator 15.
A spring may be provided between the holder piston 11 and the holder piston 11.

〔Effect of the invention〕

Since the present invention is configured as described above, even when the weight of the rod and bit becomes excessive when drilling a downward long hole, an appropriate thrust is always given to the rod and bit.
In addition, impact force can be transmitted effectively, improving drilling efficiency.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a shank rod holding device of a rock drill according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a conventional drilling device, and FIG. FIG. 4 is an explanatory diagram showing the proper drilling state of the conventional downward rock drilling machine and the state where the weight of the rod and bit is too large and the shank rod is in the dry-driving position. 3...Rock drill, 5...Shank rod, 6...Rod, 7...Bit, 9
...Blow piston, IO...Shank rod holding device, 11...Holder piston, 1
2...Pressure chamber, 15...Accumulator.

Claims (1)

[Claims] (1) In a rock drill for drilling downward long holes, the shank rod of the rock drill is equipped with a holder piston that holds the shank rod in a striking position, and a buffer means that allows displacement of the shank rod due to striking. holding device.