Piling method and apparatus

Abstract

A pile is moved downwards by a movable part inside a piling apparatus. An apparatus body is fastened to the pile by fastening elements, during piling the movable part inside the apparatus body is moved downwards, the movable part is stopped hydraulically by medium in a cylinder space without the movable part striking the apparatus body. As the downwards directed motion of the movable part is stopped, the apparatus body and the pile fastened to it jerk downwards, after which, the movable part is moved hydraulically upwards. The counterforce of the motion affects the apparatus body and the pile fastened to it by pushing them downwards. The piling apparatus includes hydraulic cylinder cylinder to the piston of which the movable part is fastened, and to the hydraulic cylinder are connected a pressure transformer, a damping apparatus and a set of control valves to stop the movable part hydraulically.

Claims

1. A piling method comprising: moving a pile or an equivalent located below an apparatus mainly downwards by means of a movable part inside the apparatus, fastening an apparatus body to the pile or equivalent by fastening elements, wherein the movable part is fastened to a piston of a hydraulic cylinder, wherein a pressure transformer, a damping apparatus and a set of control valves are integrally connected to the hydraulic cylinder, wherein the pressure transformer is between a first cylinder space and a second cylinder space, wherein during piling, moving the movable part inside the apparatus body downwards, stopping the movable part hydraulically by means of a medium in the first and second cylinder spaces of the hydraulic cylinder without the movable part striking the apparatus body or some other part, whereby, as the downwards directed motion of the movable part is stopped, the apparatus body and the pile or equivalent fastened to the apparatus body jerk downwards, after which, moving the movable part hydraulically upwards, whereby a counterforce of the motion affects the apparatus body and the pile or equivalent fastened to the apparatus body by pushing the apparatus body and the pile or equivalent fastened to the apparatus body downwards, wherein the first cylinder space is between the piston and the pressure transformer, and wherein the second cylinder space is in fluid communication with the damping apparatus.

2. The piling method according to claim 1, further comprising: adjusting the speed of the downwards and upwards directed motion of the movable part and a duration of the stops hydraulically.

3. The piling method according to claim 1, further comprising: conveying part of the medium in the cylinder space below the movable part out of the cylinder space during a downwards directed motion of the movable part.

4. The piling method according to claim 1, further comprising: conveying pressurised medium to the cylinder space below the movable part during an upwards directed motion of the movable part.

5. A piling apparatus comprising: a body and a movable part inside the body, wherein the body includes fastening elements for fastening the body to a pile, and wherein the movable part is a hammer ram, a hydraulic cylinder comprising a piston, wherein the movable part is fastened to the piston, and a pressure transformer, damping apparatus, and a set of control valves connected to the hydraulic cylinder and configured to stop the movable part hydraulically without the movable part striking the apparatus body or some other part, wherein the pressure transformer is between a first cylinder space and a second cylinder space, wherein the first cylinder space is between the piston and the pressure transformer, and wherein the second cylinder space is in fluid communication with the damping apparatus.

Description

DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described in more detail with reference to the accompanying drawings in which

(2) FIG. 1 shows a partially cut side view of a piling apparatus according to the invention and

(3) FIGS. 2-6 show side views of the inner structure of an apparatus according to the invention which includes a hydraulic cylinder and parts related to it as illustrations of principle and their cross sections in the various stages of the operation of the apparatus.

(4) FIG. 1 shows as an illustration of principle a piling apparatus according to the invention and parts pertaining to it. The piling apparatus includes a body 1, which body includes inside of it a movable part 2 i.e. hammer ram visible in its top part and a hydraulic cylinder 3 fastened to it. The bottom part of the body includes fastening elements 4 by means of which the apparatus is fastenable to a pile or an equivalent (not shown in the figures) being below it. The fastening elements are fastening elements known as such which are hydraulically-operating elements. The top part of the body includes a fastening lug for fastening the body to some apparatus.

(5) FIGS. 2-6 shows a hydraulic device required for moving a movable part i.e. hammer ram (not shown in these figures) being inside a body (not shown in these figures) and parts and elements related to it. The device includes a double-acting hydraulic cylinder 3 which is integrally connected to a pressure transformer and damping apparatus and a set of control valves. The hydraulic device in question i.e. the hydraulic cylinder 3 is connected between the apparatus body and the movable part i.e. hammer rain. The hydraulic cylinder is provided with duct fittings 13, 14 and 15, by means of which, pressure medium is conveyed to the cylinder and pressure medium is extracted from there in the various stages of the operation. The duct fitting 13 is at the upper end of the body, the duct fitting 14 is in the middle section of the body below the centre and the duct fitting 15 is in the bottom part of the body.

(6) The pressure transformer apparatus includes a pressure transformer 20 inside the hydraulic cylinder, movable in relation to it and a pressure accumulator 18 which is connected by a duct 17 to a cylinder space 21 below the pressure transformer 20. Above the pressure transformer, there is an upper cylinder space 22.

(7) A bottom part 7 of a piston 6 of the hydraulic cylinder 3 is shaped such that it forms an edge controlling the flow of medium. The controlling edge of the bottom part 7, the piston skirt, is used to close the duct fitting 14 partially or totally. The piston skirt can also push the piston of the pressure transformer 20 ahead of it.

(8) The set of control valves include valves 9-12 which control the direction and force of the motion of the hydraulic cylinder. The valves 9 and 11 are connected to a pressure source and the valve 10 is connected to the valve 9. The valve 9 is connected to the duct 13. A pressure accumulator 16 is between the valve 9 and the duct 13. The valve 10 is connected to the duct fitting 14. A return valve 12 is connected to the duct fittings 14 and 15.

(9) Next; the operation of the apparatus according to FIGS. 1-6 is described with reference to FIGS. 2-6.

(10) FIG. 2 shows a starting point from which the hammer ram is accelerated downwards and, simultaneously, the cylinder piston fastened to it is moved downwards. Then, the valves 9 and 12 are open and the valves 10 and 11 are closed.

(11) In FIG. 3, the piston skirt closes the duct fitting 14 and the pressure medium in the upper cylinder space or the piston skirt pushes the piston of the pressure transformer 20 downwards, whereby the medium from the cylinder space 21 below the pressure transformer transfers to the pressure accumulator (or damping apparatus) 18. Simultaneously, the valve 9 is closed and the valve 10 is opened. Then, the motion of the hammer ram and the piston is braked, and the pressure of the medium is stored to the pressure accumulator 18. After the hammer ram and the piston have stopped, the motion direction changes and the pressure accumulator discharges its energy to lift the hammer ram. This stopping causes a jerk which is conveyed via the apparatus body to the pile or equivalent.

(12) In FIG. 4, the motion has stopped and the medium transfers from the pressure accumulator to the lower cylinder space 21, whereby the piston of the pressure transformer 20 starts to go upwards. In this stage, the valves 9 and 11 are closed and the valves 10 and 12 are open.

(13) In FIG. 5, the piston skirt has reached the duct fitting 14, whereby the valve 11 is opened and the valve 12 is closed. Now, the pressure medium lifts the cylinder piston to a desired height from which a new work cycle starts according to FIG. 6.

(14) The apparatus can also make a short oscillating motion if no high-power motion is required. When the valve 11 is opened and the valves 9,10 and 12 are closed, the cylinder piston lifts the hammer ram to a desired height, whereby the pressure medium above the piston has been charged to the pressure accumulator 16. Then, the valve 11 is closed and the valve 12 is opened. In that case, the hammers ram starts to move downwards and it is braked by the pressure transformer which charges the pressure accumulator 18. As the direction of the hammer ram changes, the valve 11 is opened and the valve 12 is closed.

(15) When using the apparatus, the apparatus body 1 is fastened to a crane, the framework of a piling apparatus or some other device or apparatus with suitable fastening elements known as such. It can also be fastened to other constructions in a desired way depending on the purpose and use. Using the apparatus provides a jerky motion applied to a pile or an equivalent, directed upwards and downwards, the power and direction of which motion can be adjusted in a desired way.

(16) The medium is a liquid medium suitable for the purpose.

(17) The invention is not limited to the described advantageous embodiments, but it can vary within the scope of the inventive idea presented in the claims.