SU802466A1 - Percussive-action pneumatic device for sinking holes into soil - Google Patents

Description

(54) PNEUMATIC DEVICE OF SHOCK ACTION FOR WELLS IN GROUND

I

The invention relates to construction equipment and can be used for drilling wells when laying underground utilities.

A self-propelled reversible pneumatic percussion device for drilling wells in the ground is known, including a housing, a hammer, a nozzle, a back nut and a reversal mechanism 1.

The closest to the invention in terms of technical essence and the achieved result is a pneumatic percussion device for drilling wells in the ground, comprising a housing, a hammer, an air inlet pipe and an axially mounted sleeve with a locking mechanism 2.

The sleeve of this device can only be fixed in two positions; in the extreme forward position (during forward movement of the device) and in the extreme rear position (during reverse travel). As a result, the impact energy at both forward and reverse is fixed. The kickback of the device, which is proportional to the impact energy, also has fixed values.

In some cases (for example, when drilling wells in loose, impacted soils or starting the device in the ground), the recoil melt may be greater, the force of adhesion of the device with the ground. In this case, the advancement of the device is significantly slowed down or even stopped. The recoil can be reduced by reducing the impact energy somewhat, which is not possible with this device design.

The aim of the invention is to increase the rate of penetration of wells in weak soils.

This goal is achieved by the fact that the sleeve has a conical skirt, and the fixation mechanism is made of a spring-loaded ball cage with a pull cable, which is located between the inner surface of the skirt and the outer surface of the nozzle.

The invention is illustrated in the drawings, where in FIG. shows the proposed device with a forward stroke (above the axis of symmetry) and reverse (below the axis of symmetry), a longitudinal section; in fig. 2 - section A-A of FIG. one.

The device comprises a housing 1, a drummer 2 with windows 3, an air supply pipe 4, a rear nut 5 with exhaust channels 6. On the pipe 4, a step sleeve 7 having a conical skirt 8 is mounted for axial movement. A return spring 9 is placed between the sleeve 7 and the rear nut 5 Between the outer surface of the nozzle 4 and the inner surface of the conical skirt 8 there is an annular spring-loaded ball holder 10 with balls 11. A cable is secured to the holder 10 12. Air is fed into the device along the hose 13. Angle of incline of the skirt and 8 is made smaller than the angle of self-sealing of the balls 11.

The front part of the housing 1 and the drummer 2 form the front chamber 14, and the internal cavity of the drummer 2 and the sleeve 7 form the rear chamber 15.

The device works as follows.

When air is supplied to the device, the force acting on the drummer 2 from the front of the chamber 14 is greater than from the rear chamber 15, since the area affected by the compressed air from the front chamber 14 is larger. Therefore, drummer 2 begins to move backward (to the right of the drawing).

At the moment when the windows 3 will be blocked by the front edge of the sleeve 7, the flow of air into the front chamber 14 will stop and further movement of the impactor 2 will occur due to the expansion of air in the chamber 14.

When the windows 3 are opened by the rear edge of the sleeve 7, the exhaust from the front chamber 14 through the channels 6 to the atmosphere will occur. Moving further only due to inertia, the striker 2 will be stopped by the air pressure in chamber 15 and will begin to move forward.

When the window 3 is again blocked by the sleeve 7, the air in the front chamber 14 will begin to compress. At the time of the subsequent opening of the windows 3 by the front edge of the sleeve 7, compressed air from chamber 15 into chamber 14 will occur. Drummer 2, moving further by inertia, will strike body 1, the device will return to its original position, and the cycle will repeat.

during operation of the device, the sleeve 7 remains stationary, since the balls 11 of the casing 10, being wedged between the conical skirt 8 and the body of the nozzle, fix it.

To switch the device to the reverse mode it is necessary to turn off the feed

air, sweat the cable 12. In this case, the yoke 10 will move backward, and the balls 11 of the wedges tighten the sleeve 7. When air is applied, the sleeve 7 will move backward by the air pressure in the chamber 15 until the skirt 8 comes into contact again with balls 11. At the same time, the sleeve 7 will be fixed in the new position (Fig. 1, below the axis of symmetry), since the balls 11 will lock again. Now, when the drummer 2 moves, the exhaust of air from chamber 14 will occur later, and the inlet of compressed air into chamber 14 earlier. Therefore, the drummer 2, failing to brake while moving backward, will hit the rear washer 5, and when moving forward it will be slowed down by the air pressure in chamber 14, without striking the body 1. The device as a whole will move backwards.

To switch the device back to the forward stroke, turn off the air. In this case, the spring 9 will move the sleeve 7 to the extreme forward position, where it will again be fixed by the balls 11 of the cage 10.

By shifting the yoke 10 by different distances, it is possible to fix the sleeve 7 in different positions. Moreover, the farther the sleeve 7 is shifted back, the less the impact energy on the housing 1 (or more the impact energy on the nut 5). Thus, it is possible to regulate the impact energy and, accordingly, the recoil force, reducing it when drilling wells in weak soils.

Claims (2)

1. USSR author's certificate No. 263482, cl. E 02 D 17/46, 1965. 2. The patent of Germany No. 2157259, cl. 5 a 7/00, published. 1972. Se / fuveffo ± i 4 fO Phi2.2