EP2924170A1 - Pile driving hammer - Google Patents

Abstract

Pile hammer, comprising a cylinder (1), in the cylinder (1) slidably guided piston (2), in the cylinder (1) displaceably guided hammering piece (3), which is arranged in the operating position of the hammer below the piston (2) a combustion chamber (12) bounded axially by an end face (30) of the hammer (3) inside the cylinder (1) and an end face (21) of the piston (2), at least one fuel supply means by each Working cycle a predetermined amount of fuel in the combustion chamber (12) can be introduced, and at least one lubricant dispenser for conveying a lubricant between the piston (2) and cylinder (1), wherein the lubricant dispenser (51) is arranged such that the lubricant delivery by the Aufschlagschschütterung of the piston (2) is effected.

Description

The invention relates to a hammer, comprising a cylinder, a displaceably guided in the cylinder and a piston slidably guided in the cylinder percussion piece according to the preamble of patent claim 1.

Such Rammhämmer, which are regularly referred to as diesel hammers or as diesel bears, especially for foundation work in the construction industry for driving in piles such as concrete pillars, iron girders, sheet piling or the same in a building ground used. To start such a pounding hammer, the piston is pulled by means of a notching up and released at a certain height, whereupon he falls under the action of gravity down. The piston actuates a fuel pump when falling, whereby one or more injectors fuel, especially diesel oil is supplied, which inject the fuel into the combustion chamber of the cylinder. When the piston is dropped, the air in the working chamber of the cylinder is compressed and thereby heated in such a way that the fuel / air mixture present in the working chamber ignites, whereupon it burns explosively. The released explosion energy hurls on the one hand the piston to a new duty cycle back up and drives the other hand, the pile in the ground.

To minimize the friction between cylinder and piston, a constant amount of lubricant is continuously introduced via a lubricant pump. Excess and burnt lubricant flows directly into the combustion chamber of the cylinder. As a result, especially at high reflux of lubricant, the combustion process of the fuel is impaired and there is considerable smoke or soot formation of the hammer. This effect occurs especially in the partial load range of the piling hammer.

The invention aims to remedy this situation. The invention has for its object to provide a piling hammer, in which, in particular in the partial load range, the flowing in the combustion chamber amount of lubricant is reduced.

According to the invention, this object is solved by the features of the characterizing part of patent claim 1.

With the invention, a pile hammer is provided in which, in particular in the partial load range, the amount of lubricant flowing into the combustion chamber is reduced. Characterized in that the lubricant dispenser is set up such that the lubricant delivery is effected by the impact vibration of the piston, an adjustment of the amount of lubricant to the respective operating conditions of the hammer is achieved. The lubricant supply is generated by the impact shock of the piston.

In a further development of the invention, the lubricant dispenser on a control module, which is connected to a sensor for detecting the jump height of the piston (2) and / or the stroke rate of the piston (2). As a result, a dosage of the lubricant according to the Aufschlagerschütterung, which is largely dependent on the stroke rate or by the jump height of the piston, allows.

In an alternative embodiment of the invention, the lubricator comprises a piston which is arranged in a housing and limits a lubricant space for receiving the lubricant, in which a lubricant line opens and which is biased by a spring element, wherein the lubricant line is closed by a valve, the over an inertial mass is actuated. As a result, a simple mechanical and reliable lubricant quantity control is achieved. At each impact of the ram's hammer, the inertial mass in the lubricator is moved causing the valve to be actuated, thereby forcing the lubricant pressurized by the preloaded piston through the lubricant line. The dosage of the lubricant quantity is thus dependent on the impact energy of the piston of the hammer. With a hard impact (high impact energy), the inertial mass of the lubricator is accelerated more and thus lays back a larger way, whereby a longer opening time of the valve is effected. As a result, a larger amount of lubricant is pressed through the lubricant line. In the case of a softer one Impact of the piston, the inertial mass is only slightly accelerated and thus puts only a shorter way back, causing a shorter opening time of the valve is effected. In this case, only a smaller amount of lubricant is forced through the lubricant line.

In an embodiment of the invention, a plain bearing bush is arranged in the cylinder at the top, in which the piston is guided. This reduces the amount of lubricant required for lubrication, thereby minimizing the amount of unburned lubricant entering the environment.

In a further embodiment of the invention, an end piece is arranged on the cylinder, which is elastically connected to the cylinder and forms a catching groove for the piston, which for this purpose has a paragraph, wherein the plain bearing bush is arranged adjacent to this catch groove in the cylinder. This prevents the piston from being thrown out of the cylinder in the event that excessive unburnt fuel and lubricant / air mixture is applied to the piston in an operating cycle during the next cycle of operation. If the piston moves too far out of the cylinder due to excessive energy, the shoulder of the piston abuts the catch groove formed by the end ring, thereby retaining the piston. Due to the elastic connection of the end ring with the cylinder, a part of the kinetic energy of the piston is absorbed. In this case, the piston is preferably provided with a catch piston ring through which the heel is formed.

In a further embodiment of the invention, the elastic connection of the end ring with the cylinder comprises an arrangement of friction springs. As a result, a particularly effective absorption of kinetic energy of the piston is achieved.

Figur 1

die schematische Darstellung eines Rammhammers in Form von einer Dieselramme;

Figur 2

die schematische Darstellung des Kolbenendanschlagbereichs des Rammhammers aus Figur 1 mit angedeuteter Flanschverbindung des Endrings;

Figur 3

die Detaildarstellung des Ausschnitts III. aus Figur 2;

Figur 4

die schematische Darstellung des Schmierstoffgebers des Rammhammers aus Figur 1.

Other developments and refinements of the invention are specified in the remaining subclaims. An embodiment of the invention is illustrated in the drawings and will be described in detail below. Show it:

FIG. 1

the schematic representation of a piling hammer in the form of a diesel rammer;

FIG. 2

the schematic representation of Kolbenendanschlagbereichs the pounding hammer FIG. 1 with indicated flange connection of the end ring;

FIG. 3

the detailed representation of the section III. out FIG. 2 ;

FIG. 4

the schematic representation of the lubricator of the hammer from FIG. 1 ,

The diesel ram selected as an exemplary embodiment comprises a cylinder 1 which is open on both sides and which can regularly have a length of 3 to 8 meters and a diameter of 0.2 to 1.5 meters. In the cylinder 1, a piston 2 is slidably disposed. A coaxial to this impact piece 3 engages slidably in the open lower end of the cylinder 1 a. At the lower end of the cylinder 1, an annular bearing unit 9 is fixed, in which a middle shaft portion 31 of the hammering piece 3 is guided tightly and displaceably, which has a relation to the inner diameter of the cylinder 1 reduced outer diameter. The diesel ram is slidably mounted on arranged on the cylinder 1 guide jaws 13 along a Mäklers.

At the lower end of the shank portion 31 there is formed a striking plate 32 located below the cylinder 1, the outwardly directed lower convex boundary surface 33 cooperating, in use, with the upper end of a driven pile to be driven in, for example a sheet pile element.

At the upper end of the shaft portion 31 of the striking piece 3, a piston portion 34 is formed with a plurality of circumferential, axially spaced sealing rings which run on the inner circumferential surface 11 of the cylinder 1. Through the top of the piston portion 34 of the hammering piece 3, a combustion chamber 12 is limited together with the underside of the piston 2 and the inner circumferential surface 11 of the cylinder 1. The combustion chamber 12 of the cylinder 1 facing end face of the hammer 3 is ground flat with a flat fuel bowl 30.

Between the impact plate 32 of the hammer 3 and the bearing unit 9 of the cylinder 1, a damping ring 91 is arranged. A further damping ring 92 is arranged adjacent to the position unit 9 between the upper side of the layer unit 9 and the underside of the piston section 34 of the striking piece 3.

Above the hammer 3 runs in the interior of the cylinder 1 with a circumferential, axially spaced-apart sealing rings 93 provided lower working end 23 of the piston 2. The lower free, ground flat surface 21 of the piston 2 is offset by a radially circumferential step.

At the lower working end 23 of the piston 2, a mass portion 22 is formed, which extends into the upper portion of the cylinder 1 inside. At the lower end of the mass portion 22, a catch piston ring 24 is arranged on the piston 2, whose outer diameter projects beyond the outer diameter of the piston 2 in this area.

On the peripheral wall of the cylinder 1, an injection device 4 is arranged, which comprises a fuel pump 41 which is connected via a line 43 to the injection nozzle 42. The inlet of the fuel pump 41 is fed via a fuel tank 5 with diesel oil.

The fuel pump 41, which is connected to the fuel tank 5 via the line 43, has a prestressed pump lever 44 projecting into the interior of the cylinder 1, via which it is driven when the falling piston 2 passes. The injection nozzle 42 is designed and aligned such that the discharged fuel is injected in a substantially continuous beam approximately centrally on the end face of the hammer 3.

Furthermore, a lubricator 51 is arranged on the cylinder 1, which is connected to distributed in the circumferential direction of the cylinder 1 lubricant nozzles. Through the lubricant nozzles, the lubricant between the piston 2 and the inner circumferential surface 11 of the cylinder 1 is given.

The lubricator 51 comprises a housing 52 which is provided at its upper end with fastening threads 552 for attachment to the outer wall of the cylinder 1. Within the housing 52, a piston 53 is arranged, which is biased by a spring 531 and sealed against the inner wall of the housing 52 by means of a seal 532. On the piston 53, a level control rod 533 is formed, which penetrates the spring and the top side of the housing 52. The piston 53 defines a lubricant space 54, which can be filled with lubricant via a refill 41. In the bottom piece 522 of the housing 52, two lubricant lines 542 are arranged, which connect the lubricant space 54 with the bottom-side lubricant outlet 543.

On the bottom piece 522 inside the housing 52, an inner housing 55 is fixed, which receives an inertial mass 551. The inertial mass 551 is connected to a valve 556 which is disposed in the lubricant outlet 543 and biased by a spring 561. Upon actuation of the valve 56, the connection between the lubricant lines 542 and the lubricant outlet 543 is released, whereby the over the biased piston 53 pressurized lubricant of the lubricant space 54 is pressed through the lubricant outlet 543. After leakage of the lubricant, the piston 53 sinks within the housing 2, whereby the oil level control rod 533 is lowered. As a result, a fill level reduction can be seen directly visually on the basis of the protruding from the housing part of the level control rod 533. About the refill pipe 541 is a replenishment of the lubricant space 54 with lubricant.

At its the hammer 3 opposite open end a radially outwardly extending, circumferential flange portion 14 is disposed on the cylinder 1. The flange 14 opens into an orthogonal to this employed cylinder piece 141, by a spring receptacle 142 on one side and on the opposite side a Flanschaufnahme 143 for the flange 61 of the end ring 6 is formed. At the level of the flange portion 14, a circumferential groove 144 for receiving the peripheral projection 62 of the end ring 6 is further introduced into the inner wall of the cylinder 1. Below the Groove 144 is further arranged in the inner wall of the cylinder 1, a bearing groove 145 which receives a plain bearing bush 19 which bears against the projection 62 of the end ring 6.

The end ring 6 is formed substantially hollow cylindrical and spaced from its cylinder 1 end facing a radially outwardly cantilevered flange 61, whereby below the flange 61, a circumferential projection 62 is formed. The projection 62 is located in the groove 144 of the cylinder 1, wherein the projection 62 protrudes inwardly beyond the groove 144, which in turn a catch groove 63 is formed, against which the plain bearing bushing 19 is applied. In the peripheral flange 61 of the end ring 6 and the peripheral flange portion 14 of the cylinder 1 each corresponding holes 64, 146 are introduced, are guided by the screws 18.

In the formed by the flange 14 and the cylinder portion 141 Flanschaufnahme 143 an annular friction spring package 7 is arranged, which rests on the opposite side of the flange 14 on a carriage 17 which is slidably disposed between the outer shell of the cylinder 1 and the inner surface of the cylinder piece 141 , The friction spring assembly 7 and the carriage 17 are provided with holes corresponding to the holes 146 of the flange 14 to these aligned, into which the screws 18 are guided. On the screws 18, a nut 181 is screwed in each case, via which the carriage 37 is braced against the friction spring packet 7, which bears against the flange part 14.

The pile hammer described above operates as follows: In the initial state of the piston 2 is raised via a - not shown - release device in an upper position. After disengaging the piston 2, this falls under the action of gravity down, closes the working nozzle 16 and actuated with its end face 21 the pump lever 44 of the injector 4, which is sprayed through the injector 42 fuel to the fuel bowl 30 of the hammer 3. Impact atomization forms an ignitable mixture of fuel droplets and air. With the impact of the piston 2 on the hammer 3 is by the hammer 3 and exerted over this on the Rammgut a downward force, which drives this further into the ground. At the same time caused by the impact caused by the impact of the piston 2 on the hammer 3 shock the inertial mass 551 in the inner housing 55 against the biased via the spring 561 in the closed position valve 56, whereby it is opened. The duration of the opening of the valve 56 is dependent on the intensity of the impact of the piston 2 on the hammer 3. The bias of the spring 561 is set so that the required minimum amount of zuzuführendem lubricant is ensured.

During the subsequent upward movement of the piston 2 triggered by the explosive combustion of the fuel, the latter releases the working sockets 16, as a result of which the combustion gases relax and flow out via the working sockets 16. The piston 2 is now thrown with the intake of fresh air through the working nozzle 16 further up until it has reached its upper end position and repeats the cycle described.

In the event that the combustion of the fuel has only partially occurred during the aforementioned cycle, is for the subsequent combustion process an excessive amount of fuel, optionally supplemented by excess lubricating oil available. As a result of the subsequent explosive combustion of the excessive fuel, the piston is thrown upwards with excessive energy, as a result of which it is moved beyond the full upper position. In this case, the catch piston ring 24 abuts against the slide bearing bushing 19 and with this to the catch groove 63, whereby the end ring 6 is torn with the guided through the holes 146 of the flange 14 screws 18 with upwards. About the screws 18 with the arranged on these nuts 181 of the carriage 17 is pulled against the friction spring package 7, which absorbs a large part of the kinetic energy and converts it into heat energy. About the restoring forces of the friction spring 7, the screws 18 and with these the end ring 6 are moved back to their original position, after which the captured piston 2 falls under the action of gravity for the next cycle down.

In a further embodiment, not shown in the figures, a sensor for detecting the jump height is arranged on the outside of the cylinder (1), which is connected to a control device, via which a metered supply of lubricant takes place on the basis of the data detected by the sensor.

Claims (8)

Pile hammer, comprising a cylinder (1), in the cylinder (1) slidably guided piston (2), in the cylinder (1) displaceably guided hammering piece (3), which is arranged in the operating position of the hammer below the piston (2) a combustion chamber (12) delimited axially by an end face (30) of the hammer (3) inside the cylinder (1) and an end face (21) of the piston (2), at least one fuel supply means by each Working cycle a predetermined amount of fuel in the combustion chamber (12) can be introduced, and at least one lubricator for conveying a lubricant between the piston (2) and cylinder (1), characterized in that the lubricant dispenser (51) is arranged such that the lubricant delivery through the impact vibration of the piston (2) is effected. Pile hammer according to claim 1, characterized in that the lubricant dispenser (51) is arranged on the outside of the cylinder (1). Pile hammer according to claim 1 or 2, characterized in that the lubricator comprises a control module which is connected to a sensor for detecting the jump height of the piston (2) and / or the stroke rate of the piston (2). Pile hammer according to claim 1 or 2, characterized in that the lubricant dispenser (51) comprises a piston (53) which is arranged in a housing (52) and a lubricant space (54) for receiving the lubricant limited, in which a lubricant line (542 ) and which is biased by a spring element (531). Pile hammer according to one of claims 1 to 4, characterized in that in the cylinder (1) at its upper side a plain bearing bush (19) is arranged, in which the piston is guided. Pile hammer according to claim 5, characterized in that on the cylinder (1) end an end ring (6) is arranged, which is elastically connected to the cylinder (1) and a catch groove (63) for the piston (2) is formed, for this purpose a shoulder, wherein the plain bearing bush (19) at this catching groove (63) adjacent to the cylinder (1) is arranged. Pile hammer according to claim 6, characterized in that the piston (2) is provided with a catch piston ring (24) through which the heel is formed. Pile hammer according to claim 6 or 7, characterized in that the elastic connection of the end ring (6) with the cylinder (1) comprises an arrangement of friction springs (7).

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