Device producing hammering

Abstract

A hammering device comprising a body (1) from which the device can be connected to a working machine, for instance, a stroke-transmitting piece (5) fixed in the body and taking the strokes of moving and hammering mass (2) and transmitting the strokes to pile (7) to be hammered into or pulled up from the ground, whereby between piece (5) and pile (7) a clamp (6) is applied, by means of which pile (7) surface is grasped. The device includes mass (2) moving cylinders (8), by means of which the back-motion of the mass can be carried out conducting the fluid pressure to have effect on piston (16) of said cylinders on primary side (20), and by means of which cylinders the hammering motion of mass can be carried out compressing the gas on the secondary side of cylinders 8 into wanted pressure by means of fluid pressure conducted to primary side (20), whereby hammering motion is carried out discharging the fluid pressure from primary side of the cylinders.

Description

The invention relates to a hammering device comprising a body, from which the device can be connected, for instance, to a working machine, a stroke-transmitting piece in the body taking the strokes of a moving and hammering mass and transmitting the strokes to a pile or similar to be hammered into or pulled up from the ground, or to a tool, in which device between the piece and the pile and the tool a clamp is applied, by means of which the pile or tool is grasped.

Previously known, among other things, from U.S. Pat. No. 5,765,651, is a device driving a pile into the ground and also pulling it out, to which striking motion upward and downward is given by means of steam or pressure water. The pipe to be driven into ground is placed to travel through the mass centre hole. There are in connection with the mass cylinders or similar in order to produce back motion and striking motion to the mass in both directions. The strking surface of mass meets the ring-shaped counter parts, which are wedged to remain around the pipe, whereby the stroke is transmitted to the pipe.

The disadvantage of the U.S. Pat. No. 5,765,651 solution is small capacity, small size of impact surfaces and the lack of proper control if the pipe is grasped from its head so that the pipe is inside the mass not steering the motion of mass. The motion cylinder arrangement with its symmetric motions in both directions gives the mass quite a slow speed, since into the cylinders water or steam must be conducted through valves all the time during the motion. Thus the use of pressurized steam does not make even the motion faster, since steam must be conducted through a valve to the cylinder, where pressure is low in the first stage due to former direction of motion. Also the vibration is strong due to back and forth motion of the symmetric mass. The speed of back motion is as fast as the speed of the stroke motion. The back motion must be stopped without stroke, which causes inconvenient vibration in the device. If the back motion is made still lower by means of valves, the striking frequency remains modest.

In order to eliminate the above presented disadvantages a new hammering device using movable mass which is well suited for hammering piles into the ground and to pull them up and allows attaching tools to it, as a crushing hammer, and work with those tools. As to its hammering frequency the device is fast and its Stroke energy adjustable. The hammering device as per the invention is characterized in that the device includes mass moving motion cylinders, by means of which the mass back motion can be carried out conducting liquid pressure to have an effect on the cylinder piston on the primary side of the cylinders, and by means of which cylinders the mass impact motion can be carried out compress sing the gas on the secondary side of the cylinders to wanted pressure by means of fluid pressure conducted to the primary side, whereby striking motion can be produced in discharging the liquid pressure from the primary side of the cylinders.

The advantage of the hammering device as per this invention is that the hammering energy is easily regulated to a wanted value. Regulation is possible even by remote control. Acceleration of mass takes place optimally. Into the cylinder that causes the striking motion no medium at all is conducted, so the motion gets fast, when in the cylinder swelling of high-pressure gases only takes place during back motion The inconvenient vibrations of the device can be made reduced, when the cylinder piston is by the force of primary side liquid pressure forced to compress the gas space into a smaller size and to increase its pressure. In the final stage of compression it easy to make the piston motion slower by valve control and not only the slowing due to this in the final stage of back motion does hardly lengthen the time spent for back motion. There are hammering tools easily attachable to the clamping means instead of piles.

In the following the invention is disclosed with reference to the enclosed figures, where

FIG. 1 shows the device cross-cut from one side hammering a pile into the ground.

FIG. 2 shows the device cross-cut from one side hammering a pile up from the ground.

FIG. 3 shows increase of pressure on cylinder secondary side as function of the piston.

FIG. 4 shows a secondary mass moving inside the piston.

FIG. 1 is a hammering device fixed to the boom head of an excavator, which assembly is made by means of fixing components 12 included in the device. The hammering device comprises a body 1 and inside it a hammer gear is arranged by means of damping/flexible elements 3. The hammering machine has a mass 2 and cylinders 8 moving it. The other cylinder ends are fixed to the body connection beam 21 and the other ends to mass 2. In the other mass end thereis a striking surface 18 hammering striking surface 19 of counter piece 5. Counter piece 5 has a clamping device 6 working by wedge principle in a manner known per se, which tightens around pile 7. Clamping device 6 can, for instance, be opened and tightened by a hydraulic arrangement, whereby change of grip in the pile, detachments and fixings can be easily done from the cabin. piece 5. Counter piece 5 has a clamping device 6 working by wedge principle in a manner known per se, which tightens around pile 7. Clamping device 6 can, for instance, be opened and tightened by a hydraulic arrangement, whereby change of grip in the pile, detachments and fixings can be easily done from the cabin.

For control of the back and forth motion of mass 2, a steering pipe 9 is placed between parts 21 and 5. To the primary side 20 of the cylinders medium is conducted along line 14 in order to lift up the mass after stroke. There is on the secondary side of the cylinders a gas filling, against which pressure fluid then pushes the piston The gas filling is, for instance, nitrogen and compressed to high pressure depending on distance s, which the piston travels. By means of control unit 17 it has, for instance, been possible to determine beforehand to what pressure the primary side is restricted during back motion, where by a certain pressure is formed even on the secondary side of the cylinders. Pressure can be measured even from the secondary side and information transmitted to control unit 17. From valve arrangement 13 pressure fluid is conducted along line 14 to the primary side. Control unit 17 steers the change valve 13 in line 14 to open and the mass starts to strike downward. In this case the stroke length is adjusted with remote control over control unit 17 by means of pressure line 14 control or by means of pressure measured from secondary side. There is, for instance, in cylinder 8 fixing spot a permanent magnet 11 and inside body 1 a proximity switch 10, whereby by means of the location detector formed by these ones the position of the mass back motion can be detect ed. By means of control unit 17 it is possible to choose how far (distance s) the mass is returned for stroke. Pressure produced by hammering to the secondary side of cylinder is determined on basis of the return travel s length According to FIG. 3 pressure P on secondary side grows as the travel gets longer. Filling beforehand (e.g. nitrogen) on secondary side is Pe. Wanted hammering energy is received defining how far the mass is conducted by means of pressure fluid. Or otherwise, to which pressure value the pressure to be fed to primary side can be allowed to rise before the mass back motion is stopped. To produce a stroke from primary side 20 an exit for pressure fluid is opened, where by the secondary side gas pressure suddenly pushes piston 16 and then also the piston rod out, while mass 2 moves the same distance. The impact energy is E. $E={\int }_0^S\mathrm{AF}\left(s\right)ds$ where A is the piston cross-sectional area

• • the opposing pressure of primary side is not noticed in the formula)

When pre-pressure Pe is known striking energy can be produced calculating from the formula, using FIG. 3 function, by which value of distance s it found out and the back motion is adjusted as S.

By means of control centre 17 the position of mass 2 is observed and manipulated by means of detectors 10 and 11 and by the pressure detector in line 14, which is the pressure to be fed to primary side 20 and equal also to the primary side pressure when it's not the question of stroke motion. It is possible to check from line 14 pressure prevailing on primary side.

The most simple stroke length regulation (=hammering energy) takes place by moving detector 10 on body 1 surface. When it reaches magnet 11 the valve changes direction in arrangement 13. It is, however, more advantageous to use the location detecting arrangement, where detectors are not moved. Such a detecting and observing arrangement is chosen that by means of detector 10 the distances of part 11 in regard to detector 10 can be indicated to unit 17 on the whole stroke distance that comes into question. Induction detectors, proximity switches or other location indicating detecting arrangements, known per se, can be used.

Alternatively the fluid pressure of primary side or secondary side is detected and when the set pressure is reached, control unit 17 gives valve an impulse to change direction of flow for the stroke. Pressure valve is most suitably set from the cabin by remote control, whereby the size of stroke is easy to choose for each situation.

FIG. 2 shows a hammering device in an alternative way i.e. turned 180°, for instance in an excavator boom, whereby piles are hammered up from the ground. It is possible to manage with one clamping piece and clamping component arrangement 6. By means of the excavator boom it is possible to maintain pre-pressure in the pile by lifting the device upward by means of the boom with proper force uninterruptedly. Likewise pre-pressure downward is maintained in hammering piles into the ground. Pre-pressure force is transmitted over damping rubbers 3,4 and its size must be restricted in order to avoid leakage of rubbers.

If intensification of strokes is required, it is possible to arrange inside mass 2 a moving mass 17 and for it a space for moving greater than the volume required by mass 17. For instance, mass 17 has distance d, and after having done it, it dashes against the end of its space. This collision takes place with minor delay of in regard to the collision with mass 2 counterpart 5. The double stroke intensifies the stroke effect of the mass. Mass 17 can be in solid form, liquid or heavy granulate. Double stroke takes place with the device hammering both downward and upward.

In FIGS. 1 and 2 cylinders 8 are on mass outside, they can also be closer to steering pipe 9 and from their other end fixed to mass 2 end. Then the device becomes as to its diameter clearly smaller if body 1 is, for instance, a pipe. Indeed, the structural height grows a little.

Claims

1. A hammering device comprising a body (1) from which the device can be connected to a working machine, for instance, a stroke-transmitting piece (5) fixed in body (1) taking the strokes of moving and hammering mass (2) and transmitting the strokes to a pile (7) or similar to be hammered into or pulled up from the ground or to a tool connected to the device, whereby between piece (5) and pile (7) or the tool a clamp (6) is applied, by means of which pile (7) or tool is grasped and in which device strokes transmitting piece (5) and hammering mass (2) are ring-shaped and pile (7) to be hammered is arranged to travel through the ring-shaped parts, characterized in that the device includes ring-mass (2) moving cylinders (8), by means of which the back-motion of ring-mass can be carried out conducting the fluid pressure to have effect on piston (6) of said cylinders on primary side (20), and by means of which cylinders the hammering motion of mass (2) can be carried out compressing the gas on the secondary side of cylinders 8 into wanted pressure by means of fluid pressure conducted to primary side (20), whereby hammering motion is carried out discharging the fluid pressure from primary side (20) of the cylinders.

2. A hammering device according to claim 1 characterized in that cylinders (8) are from their other end fixed to mass (2).

3. A hammering device according to claim 1 characterized in that mass (2) hammering energy can be regulated by means of the length (s) of mass (2) back-motion.

4. A hammering device according to claim 1 characterized in that mass (2) hammering energy can be regulated adjusting the pressure (p) of cylinder (8) secondary side.

5. A hammering device according to claim 1 characterized in that to mass (2) additional mass (17) is arranged moving in regard to mass (2), the hammering impact of which on piece (5) takes place with delay in regard the stroke of mass (2) due to distance (d).

6. A hammering device according to claim characterized in that the device can be turned 180°, both for hammering in and pulling out piles from the ground.

7. A hammering device according to claim 1 characterized in that the device has a control unit (17, by means of which the hammering energy of mass (2) can be regulated by remote control.

8. A hammering device according to claim 1 characterized in that the device has a pipe (9) steering mass (2) and running through the centre hole of mass (2).

9. A hammering device according to claim 1 characterized in that in piece (5) pre-pressure in hammering direction can be arranged by means of the working machine or similar.