SU632801A1 - Pile-driving kick atomization hammer - Google Patents

Description

I

The invention relates to piling equipment and can be used when driving piles, dowels and other building structures into the ground.

A tubular-type diesel-hammer hammer is known, including a housing, a piston, a chimney, a combustion chamber and a fuel system I. 121- When the piston strikes the chabot, a shock impulse immersing it into the ground is formed, consisting of rectangular impulses equal to twice the time running on the piston wave compression. Due to the fact that the dynamic stiffness of the piston greatly exceeds the dynamic stiffness of the pile, the shock impulse formed in the pile head receives a pronounced peak shape at the head, which carries a small part of the impact energy that can be used to dip the pile. Much of the impact energy comes from the tail of the pulse and cannot be used to sink the pile. Increasing the weight of the piston while maintaining the same dimensions of the heap equipment further deteriorates the structure of the pulse. Thus, the famous hammers do not provide

high performance and can lead to the destruction of piles.

The purpose of the invention is to increase the productivity of the hammer by increasing the duration and optimizing the pulse shape.

This is achieved by the fact that in a pile diesel hammer, which includes a housing, a shock piston, a shock piston, a combustion chamber, and a fuel system, the shock piston is made with a stepped one.

impact end and with annular grooves, which are alternately formed at both ends of the piston concentrically with its axis, while the impact end of the piston is provided with a protective cap connected to its outer and central steps, and

the latter is through compression rings. The dynamic stiffness of each step, including the central one, is taken equal to the dynamic stiffness of the submerged structure A /) CF, where /) is the density of the material, C is the rod speed of the stress waves in it, F is the cross-sectional area.

The drawing shows the proposed diesel engine in the section.

The diesel hammer includes body I, shaft 2, combustion chamber 3, impact piston 4 with grooves 5, a protective cover 6 connected to the central piston stage by means of compression rings 7, and also a fuel system (not shown in the drawing).

The device works as follows.

The piston, the pad from the upper position, compresses the combustible mixture in the combustion chamber. The cover, which closes the access of air from the combustion chamber to the grooves of the shock piston, provides in the combustion chamber a known degree of compression, which leads to the ignition of the combustible mixture during normal operation of the hammer.

In the lowest position, the piston strikes the beam with the lower part of the central stage, creating a shock impulse that plunges the pile into the ground. The compression impulse propagating in the central stage with the speed of sound from the zone of contact with the piston at the arrival to the upper end of the central stage of the piston moves into the nearest first stage rigidly coupled with it as an extension pulse with the former absolute magnitude of amplitude, causing continuation in the central stage compression pulse, i.e. continued sinking piles. The stretching impulse moves down the first stage and on arrival in the lower part, rigidly conjugated with the second (from the central) stage, passes into this stage as a compression pulse, leaving the first stage in the stretched state, and the central stage remains in compression state. This process lasts until the state wave, moving from the steps of the wall, reaches the free end of the outer stage and, reflected from it by the impulse of the previous amplitude, but the opposite sign, and extinguishing the tension of all intermediate steps, does not return in the contact zone of the central level Porsch - shabot. At this point, the hard piston stroke on the work ends. Throughout this period, a constant impulse of efforts and speeds of displacement is transmitted to the pile, i.e., an optimum mode of using the impact energy is achieved.

on the immersion pile.

Upon completion of 111 hard blows by the pressure of gases produced during the combustion of the combustible mixture in the chamber, combustion, the piston is thrown into the upper position. The protective cover, which blocks the access of gases in the cavity between the steps, reduces noise, increases the jump height of the piston and protects the grooves from contamination.

When the upper position is reached, the cycle repeats.

As a result of the use of the invention, the impact pulse acquires an optimum shape in immersion capacity, and its duration increases in proportion to the total length of the piston stages as compared to the solid one.

Claims (2)

1. USSR author's certificate No. 294903, cl. E 02 D 7/12, 1969. 2. Lyzo B. G. Pile diesel hammers, series I. Construction and road machines NIIstroydorkommunmasch, M., 1967, p. eight.