EP0347371B1 - Crushing tongs for demolishing building structures, especially reinforced-concrete walls - Google Patents

Abstract

The crushing tongs, comprising a tongs body (7) for receiving two tongs parts (1, 1') which are each pivotable via their own centre of rotation (2, 2') and which, away from the centre of rotation, are divided up into a tongs lever (3, 3') for applying the force and a cutting lever (4, 4') for exerting the crushing force, has on the cutting lever (4, 4') means (5, 60) for detachably fastening the tongs bumps (12, 61, 63). Severing blades (6, 6') for severing reinforcements can be provided in the region of the cutting levers (4, 4'). The detachable tongs bumps (61, 63) can be detachably fastened in a bump bed (60) which is arranged detachably on the cutting lever (4, 4') or integrally formed thereon. A plurality of tongs bumps can form a working profile which differs from another working profile, which is formed from the same or a different number of tongs bumps, in the crushing action. <IMAGE>

Description

The invention is in the field of construction machinery and relates to a crusher guided by a construction machine for clearing structures, in particular structures made of reinforced concrete, according to the preamble of claim 1.

Demolition of masonry, especially that of reinforced concrete, presents some difficulties in terms of noise and time. If, in the case of non-reinforced masonry, tearing down or knocking down, possibly also blasting, can be carried out using various suitable aids, the available options for masonry made of reinforced concrete are drastically restricted. So every attempt is made to demolish such structures with chisels, hammers, pliers and other means of destruction. However, this activity was always associated with a lot of noise on the one hand and with a remarkably low performance on the other.

As is known today, concrete structures are wrongly designed as structures of the century. Especially in connection with their armouring, a tension-absorbing steel lattice, problems of durability (service life) arise and with it the problems of breaking off and clearing off such structures. The earliest samples of what is difficult for us today came from clearing away the useless bunkers after the Second World War. At that time, these tough structures could only be removed with laborious manual labor using a jackhammer and a welding torch and, apart from a small part of the manual labor replaced by machines, this has remained the case today. Reinforced concrete is difficult to demolish, it is noisy and time-consuming.

The use of concrete pliers with which the concrete is cut or cracked seems to be the most advantageous today. These hydraulically driven pliers work quietly compared to the pneumatic hammers still used and also snowing. However, the effort in terms of equipment is not insignificant. Concrete pliers work optimally only in a relatively narrow working area, so that pliers with different "bite thicknesses" are used for different wall thicknesses.

It is known that masonry made of concrete is relatively sensitive to pressure. When pressurized, a layer of concrete tends to crack. This property is used with the concrete pliers, which have a wedge effect on the concrete surface. However, the refractive powers that have to be used are quite high. They range in size from 40 to 120 tons and the force that must be exerted on the tong levers in order to break the concrete in this way.

In a concrete pliers known from GB-A-2146918, the cutting levers are provided with bumps which have to be welded on when worn. However, this means a relatively long downtime. With the cusps, a separating blade is attached to each cutting lever on a stepped shoulder of the cutting lever for cutting reinforcements in the concrete. The breaking of the concrete and the separation of reinforcements can be done in a pair of pliers cuts. In a further concrete pliers known from WO-A-880213, only the free end of the cutting lever is equipped with an exchangeable crushing jaw.

The object of the invention is to provide a concrete pliers with which the reinforcement can be separated and the concrete broken in succession in the same plier cut and in which worn out cusps on the cutting levers can be replaced with little effort.

The object is achieved by the invention defined in the characterizing part of patent claim 1.

• Fig. 1 eine in ihre Bestandteile zerlegte Betonzange gemäss Erfindung in geöffnetem Zustand gezeichnet, es ist das Beispiel einer Brechzange mit lediglich 250 kg Eigengewicht und klein(st)en Abmessungen H.B.T = 920.950.312 mm und einer Oeffnung von 450 mm, für die auch die genannten Brechkräfte gelten;
• Fig. 2 die Betonzange gemäss Figur 1 in montiertem und geöffnetem Zustand und
• Fig. 3 die Betonzange gemäss Figur 1 in montiertem und geschlossenem Zustand und
• Fig. 4 die Betonzange gemäss Figur 1 von der Schmalseite gesehen.
• Fig. 5 A,B,C zeigen die Brechkraft bzw. Schneidkraft der Zange gemäss Figur 1 als Diagramm in Funktion zur Mauer- bzw. Stahldicke, wobei die Brechkraft an einem inneren Punkt A und an einem äusseren Punkt B in der Zangenöffnung und in der Schneideinrichtung gemessen wurde.
• Fig. 6 zeigt eine Ausführungsform der auswechselbaren Zangenhöcker, welche lediglich eingesteckt und lagegesichert werden können und
• Fig. 7 zeigt eine Ausführungsform eines auswechselbaren Zangenhöckers, wie er in der Ausführungsform gemäss Figur 6 verwendet werden kann.
• Fig. 8 zeigt die Bemessung der Bisshöhe zur Mauerdicke und die daraus resultierende Spielzeit.
• Fig. 9 zeigt einen hydraulischen Antrieb, wie er in der Brechzange gemäss Erfindung verwendet wird. Die in Figur 1 gezeigte Zangenvorrichtung besteht aus folgenden wesentlichen Bauteilen. Die Zangenteile 1 und 1', die durch ihr Gegeneinanderwirken die Zangenfunktion darstellen. Die Zangenteile 1 und 1' schwenken um zwei Drehachsen 2 und 2'. Diese beiden Drehachsen sind um einen bestimmten Abstand voneinander entfernt. Dieser Abstand wird an späterer Stelle noch diskutiert. Durch die hier ca. mittig liegende Drehachse werden die Zangenteile in zwei Teile aufgeteilt: in die Zangenhebel 3,3' und in die Schneidhebel 4,4'. Die Zangenteile sind auf einem Zangenkörper 7 schwenkbar gelagert. Hydraulische Betätigungskolben 10,10' betätigen die beiden Zangenteile, der Angriffspunkt der Kraft an den Zangenhebeln 3,3' ist an den äusseren Enden 9,9' derZangenhebel angeordnet. Als Kraftbetätigungselement ist ein doppelt wirksamer hydraulischer Kolben 10,10' vorgesehen, auf dessen Arbeitsweise später noch eingegangen wird.

With the help of the figures listed below, an embodiment of the invention will now be discussed in detail. Show it:

• Fig. 1 shows a broken down concrete tongs according to the invention in the open state, it is the example of a crusher with only 250 kg weight and small (st) en dimensions HBT = 920,950,312 mm and an opening of 450 mm, for which the refractive powers mentioned apply;
• Fig. 2, the concrete pliers according to Figure 1 in the assembled and open state and
• Fig. 3, the concrete tongs according to Figure 1 in the assembled and closed state and
• Fig. 4 seen the concrete pliers according to Figure 1 from the narrow side.
• 5 A, B, C show the refractive power or cutting force of the pliers according to FIG. 1 as a diagram in function of the wall or steel thickness, the refractive power at an inner point A and at an outer point B in the pliers opening and in the Cutting device was measured.
• Fig. 6 shows an embodiment of the interchangeable pincer bumps, which can only be inserted and secured in position and
• FIG. 7 shows an embodiment of an interchangeable pincer as it can be used in the embodiment according to FIG. 6.
• Fig. 8 shows the dimension of the bite height to the wall thickness and the resulting playing time.
• Fig. 9 shows a hydraulic drive as used in the crusher according to the invention. The pliers device shown in Figure 1 consists of the following essential components. The pliers parts 1 and 1 ', which, through their interaction, represent the pliers function. The tong parts 1 and 1 'pivot about two axes of rotation 2 and 2'. These two axes of rotation are separated by a certain distance. This distance will be discussed later. Due to the central axis of rotation here, the pliers parts are divided into two parts: the pliers levers 3,3 'and the cutting levers 4,4'. The pliers parts are pivotally mounted on a pliers body 7. Hydraulic actuating pistons 10, 10 'actuate the two parts of the pliers, the point of application of the force on the pliers levers 3, 3' is arranged on the outer ends 9, 9 'of the pliers levers. A double-acting hydraulic piston 10, 10 'is provided as the power actuating element, the operation of which will be discussed later.

A pliers stem 11, 11 'is arranged on the pliers parts 1, 1' outside of the axes of rotation 2.2 'in the direction of the cutting levers 4, 4' and represents a kind of pliers. This pliers stem 11, 11 'carries a cutting edge 6, 6' for cutting reinforcements, especially reinforcing irons. To break concrete, each cutting lever 4,4 'of the pliers parts 1,1' carries a pliers cutting edge 5,5 '. Each of these cutting edges 5,5 'has at least two pliers bumps 12,12', which are interchangeable in a special embodiment. The pliers cutting edge 5 is detachably fastened to the pliers part 1 with, for example, screws 13.

Figures 2 and 3 show the concrete tongs open and closed in the assembled state. This time, only the pincer bumps 12, 12 'are to be noted, which are renamed here as rear bumps A and front bumps B. The rear humps A cause a so-called bite, with which the break point is identified and thus the break is provoked. The front humps cause a so-called afterbite, with which the provoked break is implemented. The distance between the cusps A and B denotes the length of the lever over which the refractive power would decrease if the cusps were the same size. But it is precisely for this reason that the humps are of different heights, namely in such a way that the inner humps A with the smaller lever length and the greater force effect attack earlier and thus exert the initial refractive power, while the outer humps B with the longer lever length and the smaller force effect Apply force a little later to the surface to be cracked and thus take over the final refractive power.

In this way, the breaking force of the pliers parts can be adjusted to different breaking thicknesses (wall thicknesses) according to the opening width by the distance between two bumps and by the height of the bumps.

In order to accomplish this setting option, the crushing knuckles are designed to be detachable and replaceable. According to one embodiment (FIG. 1), different pliers cutting edges 5.5 ′ with the correspondingly molded or attached pliers bumps 12, 12 ′ are designed to be insertable into the cutting lever part 4. 4 ′ and with fastening means, as shown in the figure by a screw 13, for example. attached to the cutting levers.

In another embodiment, the cusps are releasably inserted as such, similar to pin teeth in the jaw, into the cutting lever 4, 4 'or into an intermediate carrier, similar to the pliers cutting 5,5'. The pincer bumps, with cutting edge and root, are in a tapered opening and are secured, for example, by a cross pin. Since the pliers bumps exert their breaking effect under pressure, they do not have to be secured against well-known tensile forces. It is therefore sufficient to insert the cross pin through a depression in the cusp root so that it is only pinched. This will be discussed in more detail in connection with FIG. 6.

This embodiment has great advantages because the pincer bumps, which consist of a hardened material, can be prefabricated. The pliers bumps can also be well standardized. This means that all interchangeable tongs have roots of the same size and design. The cusp edge is built up at different heights on such a standard root. In this way, each pincer bump can be inserted at position A or B, depending on the desired bite profile for the pre-bite and the second bite, if necessary also for an intermediate bite, if more than two pincer bumps are to be arranged on the cutting lever 4,4 '. It is easy to see that any biting characteristic can be produced in this way. Another advantage (see Figure 8): The maximum length of the pliers is determined by the different length of the pliers bumps that form the height H. In this example when using the standard at bite point A / A (Fig. 2 and 3) in the X-axis corresponding to 300 mm. The maximum travel and thus the wall thickness is determined within these axes X and Y when the pliers are fully open. In order to obtain a small "playing time" at maximum force, it is necessary to determine the correct opening dimension, which can be seen from the force diagram in FIG. 5. If a wall of, for example, 250 mm thickness now has to be broken, this opening and the "playing time" (biting / opening) will be optimal, whereas with a wall of "only" 150 mm thickness the hump height would have to be increased in order to increase the playing time to be kept as low as possible, which is reflected in the overall clearing time. This happens when the crusher has a certain The closing track has to bite into nothing. In this way, namely the adaptation of the work profile in such a way that the playing time is minimized in addition to the changed refractive effect, the work process can also be rationalized in terms of time.

Figure 4 shows the concrete tongs seen from the side, in which representation the rather surprisingly narrow cutting lever 4 are also visible from this side. In the embodiment shown, the cutting lever thickness is approx. 40 mm, the total thickness of the pliers is just over 30 cm (this corresponds to the model T-3 of the crusher series). The lever proportions H: h and H: A for the inner tongs and H: B for the outer tongs are clearly visible. It is clear that intermediate pincers can also be used, which exert their corresponding breaking effect within the proportion H: h in connection with the preliminary and / or cooperation with the other pincers.

The suspension device 8, on which the concrete tongs are rotatably mounted about their longitudinal axis, should also be mentioned. This free rotation is necessary to avoid damaging torsional forces on the hydraulic booms to which the concrete tongs are attached. So the pliers can be attached to the masonry and closed. Any rotation or tilting of the pliers is then avoided by the rotatability of the suspension device.

According to the task, the concrete pliers according to the invention should also be able to cut through the reinforcing bars cast into the concrete either in the same or in a subsequent operation, for which purpose a plier stem 11, 11 'is provided on each plier part 1, 1' for receiving a separating blade 6, 6 '. Like the pliers bumps 12, 12 ', the separating blades 6, 6' are detachably and exchangeably fastened in the pliers stem.

In Figures 2 and 3, the mode of operation of this separation mechanism is easily recognizable. If the pliers are completely open, the separating blades are also open (Figure 2). If the pliers are closed slowly, the separating blades close and are closed, that is, the valve is cut through when the inner pliers bumps start to break. When the pliers are closed (Figure 3), the cutting blades are pushed completely past each other. So that the separating blades 6, 6 ', which also consist of a hardened material, cannot hit the masonry, they are arranged a little recessed, as can be seen from FIG. 2. The opening width of the separating mechanism is also adapted to the usual thickness of reinforcing bars, for example 40 mm, which should be sufficient for all conceivable reinforcements.

Before going into the refractive power diagrams, attention should be drawn to another advantage of the interchangeability of the pliers bumps and also the separating blades. The breaking of the concrete is based on the wedge effect with which the surface layer of the concrete wall is driven apart. New pincer bumps have a better wedge effect than blunt pincer bumps. In addition, the inner pincer bumps are exposed to greater force and therefore wear out faster than the outer pincer bumps. Since the pincer bumps can now be replaced individually and therefore the replacement is also more cost-effective, the breaking performance can be kept much higher at the same cost as before. In addition, there is the possibility of an optimal hump arrangement with regard to hump height, which effectively adds to the improved breaking performance. The same can also apply to the separating blades 6, 6 ', the shape and arrangement of which can also be varied to increase the shear effect.

FIGS. 5A, B and C show refractive power or cutting force diagrams as a function of the wall thickness or steel thickness. The force attack on the material to be cleared is shown at the inner pliers bumps at point A, at the outer pliers bumps at point B and between the separating blades at different operating pressures. The operating pressures are 150, 175, 200 and 225 bar. The refractive power is between 35 and 60 tons between the inner, 20 to 36 tons between the outer pliers bumps for wall thicknesses of 10 to 40 cm (see also legend to Figure 1) and the cutting force between the separating blades is between 50 to 80 tons for reinforcing bars between 10 and 40 mm. The proportions of the pliers levers are approximately as follows: the distance from the axis of rotation 2.2 'of a pliers part 1.1' to the force application point in the pliers lever 3.3 ', transmitted to the cutting lever 4.4', is sufficient between the inner and outer pliers bumps in points A and B. In this way, the inner pincer bumps experience a higher breaking pressure than the forceps lever force and the outer pincer bumps experience a slightly smaller one.

The refractive power diagrams correspond to a pair of pliers with a maximum opening of 45 cm. It can be seen that the refractive power begins to decrease, a little over 25 cm between the inner tongs at wall thicknesses, a little over 20 cm between the outer tongs at wall thicknesses. The reason for this is the pliers geometry, which depends on the length of the cutting lever or the length of the pliers. While the pliers lever length is constant, the cutting lever length varies (in the example discussed by approx. 25 cm).

The force on the tong levers 3,3 'is exerted hydraulically by a double-acting cylinder. The double-acting cylinder has a flying piston and is operated with both piston surfaces, which means that the hydraulic pressure is on one side of the piston on the outer piston crown and on the other the piston side at the same time placed on the inner (lower) piston crown. In this way, with a very short design of the concrete tongs, the approximate doubling of the piston area in one direction of action almost gives the force of two hydraulic cylinders. This saves you a pressure intensifier, which usually has to be used to obtain the necessary refractive power of 30 to 40 tons at an operating pressure of approx. 150 bar. The usual known pressure intensifiers have a translation effect of approximately a factor of 2 to 4. FIG. 9 shows the basic illustration of such a cylinder: areas A with 2 times the largest area or pressure for closing the crusher via the hydraulic inlets 90, 90 ', slowly and with the highest pressure closing, that is, great force, that is, the effect of two cylinders is expressed; Areas B with 2 times the smallest area for opening the crusher via the hydraulic inlets 91,91 ', opening quickly and with low pressure. The overall effect is as follows, slow when a lot of force is used and fast when little force is used, which results in an optimal work cycle.

Figure 6 now shows the device with the interchangeable pliers bumps in one embodiment, with which the concrete pliers can be used with the exact "bit" or only new teeth. The entire part represents a pliers cutting edge 5, as can also be seen in FIG. 1 with molded bumps. This plier cutting edge consists here in detail of a bump bed 60 with the recesses 62 and 64 for receiving the pointed bumps 61 and 63. These bumps are made of a hardened material and there are also the actual wearing parts which, if blunt, are replaced. The solvability is not only due to wear, but also to achieve a work profile, which is formed by a variable hump height and hump arrangement. To stay with the example, the hump 61 is the higher hump A and the hump 63 is the lower hump B. Together they form a work profile. Now the bump bed 60 is also designed here so that it contributes to the work profile. You could also design the cusp bed without a shoulder and use longer and shorter cusps or embed cusps of the same size at different depths et cetera.

As already explained above, the working profile causes a different breaking effect depending on the forceps opening, which can be used accordingly. For example, on the basis of empirical knowledge, tables can be created on the basis of which the correct cusp beds and the corresponding cusps in the corresponding number can be read and selected for a specific breaking effect.

The bump bed 60 is screwed onto the cutting lever 4 of the concrete pliers, for example, for which the screws 67 and 68 are shown. The pincer bumps 61, 63 are inserted into the recesses 62, 64 in the bump bed. So that the pressure force transmission from the bumps to the bump bed is ensured on the one hand and the bumps can be easily removed from their seat again, the bumps in the seating area 61 ', 63' (slightly towards the bottom) are tapered. The humps are fixed in the hump bed with cross pins 65, 66. Since the pincer bumps are not subjected to tension, this type of fixation is sufficient.

FIG. 7 shows an embodiment of a pincer with a hard metal tip, with which very good results were achieved. The hard metal tip 70 is simply pressed into a steel bed 72 of the cusp and held by the pressing tension. A heavy-duty clamping sleeve 73 serves as an intermediate insert between the bump bed and the steel bed for the hard metal tip of the entire pincer bump.

If a pair of pliers with only two bumps was discussed in the example, it should be mentioned that a pair of pliers can have three or four, possibly more bumps, which has already been documented above with the term "bit".

Claims (4)

1. Crushing tongs for demolishing building structures, in particular of reinforced concrete, with a tong body (7) for receiving two tong parts (1, 1') which are pivotal via a respective individual pivot (2,2') and, remotely from the pivot, are divided into a tong arm (3, 3') for the gripping force and into a cutting arm (4, 4') for exerting the crushing force, wherein each cutting arm (4, 4') is provided with at least one internal hump (A) and one external hump (B) with respect to the pivot (2, 2') and wherein the tong parts (1, 1'), remotely from the pivot (2, 2'), have a tong structure (11, 11') projecting as an arm from the humps (A, B), the tong structure (11, 11') is the carrier of a severing blade (6, 6'), and the severing blade (6, 6') is arranged at a smaller distance than the humps (A, B) from the pivot (2, 2').

2. Crushing tongs according to claim 1, characterised in that the humps (A, B) of each cutting arm (4, 4') are inserted in a hump bed (60) which, in turn, is detachably supported on the cutting arm (4, 4').

3. Crushing tongs according to claim 2, characterised in that the humps (A, B) are shaped on the hump bed (60).

4. Crushing tongs according to claim 1 or 2, characterised in that a linear motor formed from two cylinders (10, 10') and two pistons connected by a common piston rod acts on the tong arms (3, 3').

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