DE29512754U1 - Impact device for mobile flat drilling technology - Google Patents

Description

Impact device for mobile shallow drilling technology

Description

The invention relates to an impact device according to the preamble of claim 1.

In such drilling rigs, the fall tool is attached to a rope that is guided from a rope drum or winch fixed to a chassis via at least one rope pulley located in the mast crown and a motor-driven impact device arranged on the boom or lifting mast.

Rope percussion drilling in loose rock is also widely referred to as rope free-fall drilling and is one of the dry drilling methods.

Rope free fall drilling is a drilling method named after the physical law of free fall, in which the drilling tool falls from a given height to the bottom of the borehole. This constantly repeating work process - lifting and free fall - is generated by the rope striking device of the drilling rig. The striking rope is guided from the striking rope winch via the striking device and the rope pulleys of the mast crown to the borehole.

From DE 22 02 992 B2 and EP 0657 615 A2, eccentric impact devices are known in which the impact cable is deflected by a hydraulic motor-driven and circularly rotating cable pulley and thus the drilling tool (valve) is lifted.

In these solutions, the rope pulley axis is arranged eccentrically to the drive axis. The eccentric impact device is arranged on the mast or on the structure frame of the drilling rig between the impact winch and the mast crown. In order to achieve the greatest possible impact stroke, the impact rope is guided over two fixed rope pulleys, between which the eccentric rope pulley is arranged. The main disadvantage of the eccentric impact devices is that the constant deflection and relaxation of the rope leads to alternating bending stress and thus to increased wear of the impact rope.

Cylinder striking devices are also known. The cylinder striking device works according to the principle of deflecting the striking cable by extending and retracting a hydraulic cylinder, with the deflection cable pulley being attached to the piston rod of the cylinder. The cylinder is arranged in the mast crown in such a way that the striking cable is deflected between the fixed cable pulleys of the mast crown by extending and retracting the piston. The additional deflection of the striking cable by the deflection cable pulley also causes a bending fatigue load on the striking cable and thus leads to increased wear.

Based on the disadvantages of the prior art, the object of the invention is to provide the rope guide and thus the rope movement during the impact stroke in drilling rigs with impact devices in such a way that alternating bending stress on the rope is avoided.

This object is achieved according to the invention by the features of the main claim, the subclaims show further advantageous embodiments of the invention.

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According to the main features of the invention, a first rope pulley of the mast crown is fixedly mounted and on the axis of this fixed rope pulley or with the pivot point in front of or behind the axis of the fixed rope pulley, a striking arm is mounted, which carries a second rope pulley at its other end.

In this way, the striking arm with the second rope pulley can be pivoted around the axis of the first rope pulley, whereby the second rope pulley together with the rope resting on it can perform an up and down movement in the sense of a striking stroke movement.

The striking stroke movement is carried out by a hydromotor drive, with a gear if necessary, which is arranged in the mast crown below the striking arm and in the area of the first rope pulley. This drive drives a cam disc, which rolls on a bearing of the striking arm. The striking arm is raised when the cam disc rotates and according to the shape of the cam disc and falls downwards after the dead center is exceeded, so that the desired vertical movement (lifting stroke) of the rope and fall tool is carried out.

When the striking arm moves downwards, the kinetic energy created by the striking arm hitting the mast/mast crown system is absorbed by a hydromechanical and/or elastomeric damper. This reduces the load on the components and minimizes the impact noise.

The main advantage of the solution according to the invention is that when executing the impact stroke, in addition to the

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When the rope is deflected over the two pulleys on the mast crown, no further deflection of the rope occurs in the sense of a disadvantageous alternating bending stress.

For further explanation of the invention reference is made to the claims.

Details, features and advantages of the invention will become apparent from the following description of embodiments. The accompanying drawing shows

Fig. 1 shows a schematic representation of the impact device according to the invention.

The basic structure and mode of operation of the new impact device with impact arm 3 can be derived from the drawing in Fig. 1.

The first rope pulley 1 is fixedly mounted on the mast crown in a suitable mounting frame 9. The striking arm 3 rests on one end of the AGhse of this rope pulley 1. The second rope pulley 2 is attached to the other side of the striking arm 3. The striking arm 3 can therefore be pivoted around the axis of the rope pulley 1 together with the rope pulley 2 mounted on the right end of the striking arm as shown in Fig. 1, so that the rope 4 can perform an up and down movement (lifting-falling cycle) at its free end with the falling tool.

The movement of the impact arm 3 is driven and controlled by the hydromotor drive 5 with cam disk 6, which is also fixed in the mounting frame 9. The impact arm 3 rests on the cam disk 6 by means of the bearing 7 and is rotated when the cam disk 6 rotates.

depending on the shape of the guide surfaces of the cam disc, raised and falls after the dead center is exceeded.

Damping elements, designed as elastomeric dampers 8.1 and hydromechanical dampers 8.2, ensure that the falling movement of the impact arm 3 is limited and reduce the load on the affected components as well as the impact noise.

-8-List of reference symbols

1 - first pulley (fixed)

2 - second pulley (pivoting)

3 - Impact arm

4 - Rope

5 - motor drive

6 - Cam disc

7 - Bearing of the striking arm

8 - Damping elements

9 - Mounting frame

Claims (3)

-6- Protection claims 1. Impact device for mobile shallow drilling technology, in which the impact cable with the fall tool located at the end of the impact cable is guided to the borehole via the impact device and the rope pulleys of the mast crown and the drive motor for the impact device is arranged in the mast area,
characterized by the following features: - a first pulley (1) of the mast crown is fixed, a second pulley (2) of the mast crown is mounted so as to be pivotable about the axis of the fixed pulley (1) or with the pivot point in front of or behind the axis of the fixed pulley, on or in a movable striking arm (3), the striking arm (3) being supported at one end on the axis of the pulley (1) or another pivot point and carrying the pulley (2) at its other end; - to carry out the stroke movement of the striking arm (3) with the rope pulley (2) and the rope (4) resting on it, the motor drive (5), if necessary with gear and cam disc (6), is positioned in the mast crown in such a way that the striking arm (3) rolls on the cam disc (6) by means of a bearing (7) and thereby carries out the vertical up and down movement of the rope with the fall tool. 2. Impact device according to claim 1, characterized in that damping elements (8) are arranged below the impact arm (3) at its end facing away from the fixed roller (1), against which the impact arm (3) impacts in the downward movement and subsequently supports itself. 3. Impact device according to claim 2, characterized in that the damping elements (8) are designed as hydromechanical and/or elastomeric dampers