EP0931643B1 - Baling press, in particular for cardboard waste, paper foils and the like - Google Patents

Description

The invention relates to a baler, in particular for cardboard waste, paper, foil and the like., With a compression channel in which a plunger is movable back and forth driven and with a drivable feed, which in coordination with the plunger and in response to a sensor promotes material to be pressed through a Preßkanaleinfüllöffnung in the compression channel.

In DE 39 41 092 C1 a baler for the compaction of stalk crop is shown and described, which has a feed with Preßrotor, a Vorverdichterkanal with Druckmeßsensor in the side wall and a compression channel with a plunger, wherein the hydraulically driven plunger in response to the measured pressure of Pressed material in Vorpreßkanal works. There is neither an overload protection for the feeder provided nor a control of the feeder in dependence on the drive load. The pressure gauge in Vorpreßkanal is not suitable in particular for cardboard because it can lead to interference from false triggering by jamming.

EP-A-0 686 493 discloses a hydraulically driven vibrating piston press for pressing cardboard waste. After a predetermined number of strokes of a hydraulic feeder, the plunger is driven, which compresses the material in the press channel.

In a channel baler disclosed in DE 12 14 138 B, an equal amount of pulp is to be supplied to the press channel before a press piston compresses this amount of pulp. A feed channel opening into the press channel is first closed when the output is closed, e.g. supplied by a fan air flow, the input side fibers, which build up to appropriate filling height. In certain filling height, a light barrier is provided. If the fibers reach this filling level, the light barrier switches on the feeding device, which now pushes an equal amount of weight into the pressing channel with each stroke. If the fiber plug drops down to a second, lower-lying light barrier, it shuts off the feed device and the pressing piston is once again moved back and forth in order to press the material pushed into the pressing channel. After each stroke of the plunger, the feeder is always turned on again when the filling height is increased again by the fiber material supplied to the light barrier.

This baler has the great disadvantage that it is not suitable for the processing of cardboard, paper or foil. If, for example, a single large carton moves in front of the upper light barrier, the feed device is set in motion when the supply channel is virtually empty, and the pressure piston also performs a working stroke, although hardly any material is to be compacted. Both feeder and plunger perform unnecessarily many strokes, resulting in uneven bales, low throughput and high wear. In the other case, it can quickly come to overload the feeder, if z. B. precompressed material such. B. newspaper bundle get into the feed.

DE 27 10 412 A1 discloses and describes a high bulk baling baler whose main press chamber has a pre-press chamber with two conveyors which, depending on a meter for the crop, e.g. be triggered by a movable wall. A first, designed as Raffer conveyor initially conveys the material against a Vorpreßkammerwand until the Rafferantrieb when addressing a Dichtemeßgerätes off and a second, designed as a transverse thrust member conveyor is switched, which pushes the pre-pressed Halmgutportion in the Hauptpreßkammer and the Preßkanaleinfüllöffnung closes until the Plunger pressed the supplied material. In the meantime, the Raffer was turned on again, so that material is already in the pre-compression chamber and the second conveyor must dodge at its hub in the starting position.

In addition to the high cost of two conveyors in particular the transverse thrust member for the processing of cardboard, paper or foil waste is unsuitable because the material would clog at the transfer point Raffer, transverse thrust member. In addition, the transverse thrust member is complicated, because it must temporarily close the Preßkanalöffnung Finally, an overload protection for the transverse thrust member is missing.

It has also been proposed (DE 27 14 760 A1) to control the plunger and the feeder of a baler for agricultural crops in response to a arranged in a Vorpreßkanal sensing device. The plunger closes in its rest position initially the Preßkanaleinlaßöffnung, while the feeder is completely pulled out of the Vorpreßkanal. A rotary feeder upstream of the feeder continuously conveys material against the pre-press passage exit closed by the plunger until the sensing device fully pivots out of the pre-press channel, thereby engaging a clutch to actuate the plunger and feeder for a single cycle. Another disadvantage here that the material is completely pre-compressed outside the Hauptpreßkanals and only then pushed into the Hauptpreßkammer. The Abfühleinrichtung is not suitable for cardboard, as it can be operated by jammed boxes and thus lead to false triggering. Furthermore, an overload protection for the feeder is missing. Overall, the construction with switchable couplings is very expensive.

The invention has for its object to improve the baler described above so that both bulky cardboard waste and paper waste and thin waste film can be pressed without distortion of the feeder trouble-free bales in the same packing thicknesses with greatly fluctuating Materialzuführmenge, with a simple and cost-effective solution to develop is.

Based on the baler described above, this object is achieved in that the feeder in its drive a torque or pressure or force-absorbing Lastmeßfühler whose signals are used to automatically control the drive of the feeder in response to presettable load values of the feeder.

In this way, the load on the feeder can be surprisingly easy to turn on and off the feeder. The load sensor according to the invention is not directly affected by the material to be pressed, the load sensor rather performs the function of a power supply, which not only ensures a homogeneous, adjustable filling density, but brings too high load demand, the feeder in a parking position. Complicated indirect sensing devices are avoided because the feeder now automatically adapts to different types of material and quantities and controls itself in principle. An overload of the feeder is certainly excluded, as this previously switched off load-dependent or reversed, moves to its original position outside of the feed and turns on the plunger. With a small amount of material feed, the feeder automatically performs a higher number of strokes to achieve a uniform feed of the Preßkanales. Empty strokes of the plunger are avoided. Due to the omission of an indirect sensing device in a pre-compression channel is made possible that the feed pre-compressed the material with open Preßkanaleinfüllöffnung in the compression channel, which has a favorable effect on a good bale shape and high press density.

A structurally particularly simple embodiment is that the feeder and the plunger hydraulic drives with hydraulic valves, which cooperate with an adjustable pressure switch or pressure sensor for the hydraulic pressure in the drive of the feeder. Thus, only simple hydraulic machine elements are used. In addition to the particularly simple control option, the manufacturing costs and the maintenance costs compared to the known feeder control systems due to the low number of parts are significantly reduced while increasing the reliability.

In a further embodiment of the invention, it is proposed that the feeding device continuously conveys the material to be pressed with open Preßkanaleinfüllöffnung and in retracted "parking position" of the plunger in the compression channel until a predetermined load value is reached, in which the load sensing the hydraulic valves indirectly via a control unit or directly controls so that the feeder temporarily stops there at the next reaching the rest position until the plunger once advanced for final compression of the material located in the pressing channel in its pressing position and then returned to its parking position, so that a new feed cycle begins. The pre-compression and feeding into the compression channel are thus performed only with a single conveyor element, which has a favorable effect on the bale shape that the compression channel is now filled by several strokes of the feeder and not by a single stroke as in known feeders. In the case of foreign bodies or other obstructions or blockages, it is advantageous that the supply device can be reversed when a defined maximum load is reached, ie moves back from the respective blocking position in their parking position and remains there until the plunger has eliminated the blockage after a pressing stroke.

Further features and advantages of the invention will become apparent from dependent claim 4 and from the following description of an embodiment with reference to a single, the channel baler in longitudinal section schematically representing figure.

Construction and operation of the invention are described below on a vibrating piston press. However, the invention can also be applied according to piston presses with rectilinear pressing piston.

A stationary Preßraumgehäuse 1 is constructed on support feet 2 and has a compression channel 3 with an arcuate Preßkanalabschnitt 4, in which a swinging about a horizontal axis 5 mounted plunger 6 reciprocates between an upper, drawn in dashed line position 7 and a lower , drawn in full line position 8.

The upper wall 9 of the Preßkanalabschnittes 4 has a filling opening 10, which is a feed space 11 upstream. The plunger 6 is the filling opening 10 in its lower position 8 completely free. The feed space 11 is formed by a feed table 12, which extends between two side walls 13 and opens at a distance above the lower position 8 of the plunger 6 in the Preßkanalabschnitt 4. In the feed table 12 a uniformly in the direction of arrow 14 circulating conveyor belt 15 is arranged. The transition from the conveyor belt 15 to the filling opening 10 is effected by a roller 16 and a fixed platform which ends shortly before the movement path of the pressing piston 6 with a fold and forms the lower edge of the filling opening 10.

Above the filling opening 10, a feed device 17 is arranged, the Rafferzinken 18 are shown in solid line rest position 19 or park position almost outside of the feed space 11 and a crank gear 20 during a work cycle on a kidney-shaped orbit 21 through the feed space 11, in the filling opening 10 and are moved through the compression channel 4, while the plunger 6 is in a lower parking position 8 shown in solid lines.

Plunger 6 and feeder 17 are shown in an open hydraulic system. The drive of the plunger 6 is effected by a hydraulic pump 22 with reservoir 23 and electric motor drive and two double-acting hydraulic cylinder 24 with the interposition of a 4/3 hydraulic valve 25, which is controlled by a control unit 26, z. B. electromagnetically in response to a located in the pump outlet pressure line 27, adjustable pressure switch 28 is controlled. Alternatively, an adjustable pressure sensor can also be provided. The drive of the feed device 17 is effected by the same hydraulic pump 22 by a hydraulic motor 30 acting on the axis of rotation of the crank 29 with two directions of rotation with the interposition of one of the control unit 26 electromagnetically actuated 4/3 way valve 31 in response to the pressure switch 28 or the pressure sensor.

The operation of the oscillating piston press is as follows:

The plunger 6 is in the lower position 8 (parking position), in which the piston rod is extended. The conveyor belt 15 and the Rafferzinken 18 of the feeder 17 move in the direction of the arrows 14, 32 and push the cardboard waste to be pressed through the filling opening 10 in the compression channel 4 via the plunger 6 and against the stalk 3 located in the stalk 3 strand. With increasing filling of the press channel 4, the resistance of the material to be inserted into the press channel 4 increases to the feed device, whereby the hydraulic pressure in the pressure line 27 to the hydraulic motor 30 increases. If this pressure reaches the switching value set on the pressure switch 28, the pressure switch 28 sends a signal to the control unit 26 or also directly to the 4/3 directional control valve 31. This signal causes on the one hand by appropriate control of the 4/3 way valve 31 in the zero position, the feeder 17 moves to its parking position 19 and stops there and on the other hand, the hydraulic valve 25 is driven so that the plunger 6 performs a Preßhub. When the plunger has returned to its lower position 8, the feeder 17 automatically switches on and a new filling cycle begins until, again, the pressure switch 28 or alternatively the pressure sensor gives a signal to stop the feeder 17 and start the plunger 6. When the pressed strand length is reached, the bale is set in a manner known per se.

In order to allow Reversierbetrieb the feeder 17 at any disturbances or blockages and thereby avoid machine damage, in addition to the first pressure switch 28, a second, not shown pressure switch with higher set pressure value or an illustrated pressure sensor 34 is provided, the switching pressure is above that of the first pressure switch 28 , If, for example, the first pressure switch 28 fails or if the pressure rises during the remaining stroke to the higher level, the second pressure switch or pressure sensor 34 responds at the increased pressure, whereby the hydraulic valve 31 is actuated so that the direction of rotation of the feed device 17 reverses to the operator by an audible or visual signal. By reversing the feeder 17, the tines 18 are pulled out of the clogging area and temporarily remain in their rest position 19 until the disturbance is eliminated.

In the context of the invention, it is in principle also possible to use the load sensor without pressure-controlled feeding exclusively as overload protection. The feeder then works in timing to the plunger with a certain number of strokes / Preßkolbenhub and is turned off in case of overload by the load.

Claims (4)

1. A baling press, especially for cardboard waste, paper, foil and the like, comprising a compacting channel (3, 4) in which a compacting plunger (6) is drivable in a reciprocating manner, and a drivable feeder (17) which, in co-ordination with the compacting plunger (6) and as a function of a sensor, feeds the material to be compacted into the compacting channel (3, 4) through a compacting-channel charging opening (10), characterised in that the feeder (17) has, in its drive (22, 30, 31), a torque- or pressure- or force-detecting load sensor (28, 34), the signals from which are used for automatically controlling the drive (22, 30, 31) of the feeder (17) as a function of presettable loading values of the feeder (17).
2. A baling press according to claim 1, characterised in that both the feeder (17) and the compacting plunger (6) have hydraulic drives (22, 24, 30) with hydraulic valves (25, 31) which co-operate with an adjustable pressure switch (28) or pressure sensor (34) for the hydraulic pressure in the drive of the feeder (17).
3. A baling press according to claim 2, characterised in that the feeder (17) continuously feeds the material to be compacted directly into the compacting channel (3, 4) when the compacting-channel charging opening (10) is open and the compacting plunger (6) is in its retracted parked position (8) until a predetermined loading value is reached, at which the load sensor (28) controls the hydraulic valves indirectly via a control unit (26) or directly so that the feeder (17) temporarily stops the next time it reaches it rest position (19) until the compacting plunger (6) has advanced once into its compacting position (7) for final compaction of the material in the compacting channel (3) and has then returned to its parked position (8) so that a new feed cycle begins.
4. A baling press according to any one of claims 1 to 3, characterised in that the feeder (17) is reversible on reaching a defined maximum load, e.g. by a hydraulic motor (30) with two directions of rotation, i.e. travels back from the respective blocked position into its rest position (19), where it stays e.g. until the compacting plunger (6) has removed the blockage after a compacting stroke.

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