EP1108367B1 - Method and device for cutting at least a mobile continuous rod in the tobacco industry - Google Patents

Abstract

The device uses circulating blade with at least one guide for the product run driven by a crank drive synchronously with the blade. A crank rod is located on a crank pin eccentric to the crank drive shaft and is connected to a support for the product run guide. A first circulating compensating mass is provided in the area of the crank or its drive. A second compensating mass (42) receives around a shaft (43), which has a distance from the shaft (40) around which the first compensating means (41) revolves. The support or pinion (8) is formed from flexible support components (22-24) formed as leaf springs. At a distance from the drive shaft (37) of the crank (36) is a compensation shaft (44) driving the second compensating mass to revolve synchronously.

Description

The invention relates to a method for cutting at least one endless moving strand of the tobacco processing industry into rod-shaped articles by means of a rotating knife in which the strand is supported by a strand guide, which is offset by a drive, preferably a crank mechanism in a reciprocating motion , Wherein the unbalance of the crank mechanism is partially compensated by a rotating with this first balancing mass.

The invention also relates to a device for severing at least one endless moving strand of the tobacco-processing industry in rod-shaped articles by means of a rotating knife, with at least one of a drive preferably a crank drive, synchronously driven to the knife strand supporting the strand guide, wherein a crank rod on the one hand on an eccentric stored to the drive shaft of the crank crank pin, on the other hand connected to a strand guide supporting support, and with a first circumferential balancing mass in the range of the crank or its drive.

By "rod-shaped article" for the purposes of the invention, both tobacco products such as cigarettes, cigars, cigarillos and filter rods or filter sleeves are meant. In the following, for the sake of simplicity, only cigarettes are used.

In cutting devices of extrusion machines, an endless cigarette rod moved in the direction of its longitudinal axis is cut into individual cigarettes. The strand guide guides the cigarette rod in the region of the cutting device and is formed at the cutting point as a counter blade or edge of the cutting edge for the rotating knife. Since the cigarette rod continues to move during cutting, and in modern stranding machines with very high speed, the cutting point must be moved during the cut with the cigarette rod. For this reason, the strand guide is movably supported in the strand direction and driven by a drive, usually by a crank mechanism, to reciprocating movements.

The strand guide is formed as a so-called tube, which has a recess through which the knife passes to the cutter of the cigarette rod. It is driven by a crank rod of the crank mechanism synchronously with the knife. However, this proven design makes problems with performance increases of the strand machines, which provide enormous production (up to 16,000 cigarettes / min.). The relatively large masses of this type of drive, whose imbalances can only be partially compensated, have large vibrations result, the z. B. as floor vibrations, reinforced structure-borne noise (noise) and impairment of the function of adjacent modules and / or electrical components noticeable. Since the crank axis of rotation is not in the main plane of movement of the tubes (and for structural and Schnittchnischen reasons there can not be and should), is for such Transmission in this way, in principle, no complete balancing possible. However, the forces introduced into the machine can be significantly reduced compared to the unbalanced state.

So-called "crank mechanisms" for the tubes of extruding machines, which are kinematically in principle four-link coupling gears, but can be interpreted as crank mechanisms in the use of rockers made of a flexible material and with sufficient swing lengths, are known in many embodiments, for. By GB 1 556 267, US 4 534 252 or DE 2 233 064; however, they only partially solve the problems described above.

The problem underlying the invention is to influence the outgoing from crank mechanisms of the type mentioned vibrations so that the harmful forces and moments emanating from them, including the sound radiation, are reduced.

The solution according to the invention consists in that, in synchronism with the first balancing mass, a second balancing mass is driven by a shaft arranged at a distance from the crank drive to a circulating movement. By "synchronous" is meant that the second balancing mass rotates at the same speed as the first balancing mass -. The directions of rotation of both masses are opposite.

According to an important development of the invention, which allows to reduce the vibrations due to imbalances and thus the forces and moments caused by these on the machine even further, is that synchronously to the first balancing mass a third driven by the crank gear balancing mass to a Circulating motion is driven.

The device mentioned above is characterized in that a second Balancing mass is provided which rotates about an axis which has a distance from the axis about which the first balancing mass rotates.

In a further development of the invention, the support (rocker) is designed as a flexible support for the strand guide. The carrier may consist essentially of leaf springs made of carbon fiber reinforced plastic.

A preferred embodiment of the invention is characterized by a at a distance from the drive shaft of the crank arranged the second balancing mass to synchronous revolutions driving balance shaft. The drive shaft of the crank and arranged at a distance therefrom balance shaft can be kinematically connected to each other according to the invention by means of a belt drive, preferably a toothed belt, it being important to ensure that the waves rotate in opposite directions. The center of gravity of the second balancing mass is advantageously located in a vertical plane with the center of gravity of the first balancing mass, when the reciprocating movement of the tubes takes place substantially in a horizontal plane.

An important further embodiment of the invention, which leads to a further improvement of the mass balance of the crank mechanism, is that with the drive shaft of the crank, a third balancing mass is kinematically in communication. The third balancing mass is advantageously driven by the drive shaft of the crank to circulations. It is also advantageous in an axial distance from the first balancing mass and arranged rotated relative to this.

The crank mechanism according to the invention with its extensive mass balance is suitable for driving a strand guide with a guide tube for a strand of the tobacco-processing industry, in particular a cigarette rod, in a so-called single-strand machine. However, an advantageous application is also given in so-called two-strand cigarette manufacturing machines in which two strands are guided by two guide tubes, which are of a carrier configuration and a crank drive are drivable, and through which a knife cuts the two strands.

The advantage associated with the invention is that a significantly better mass balance can be achieved by the use of a second balancing weight and even more by the use of a third balancing mass, which significantly reduces the vibrations transmitted to the machine and the floor.

The invention will be explained in more detail with reference to an exemplary embodiment:

Figur 1

eine Seitenansicht einer Strangführung mit einem Kurbeltrieb in einer Zweistrangmaschine zum Herstellen von Zigaretten,

Figur 2

eine Ansicht entsprechend Pfeil A in Figur 1,

Figur 3

ein Diagramm des Verlaufs der auf die Zigarettenmaschine wirkenden Kräfte über der Zeit bei den einzelnen Ausgleichsmaßnahmen,

Figur 4

ein Diagramm des Verlaufs der auf die Zigarettenmaschine wirkenden Momente über der Zeit bei den einzelnen Ausgleichsmaßnahmen.

Show it:

FIG. 1

a side view of a strand guide with a crank mechanism in a two-line machine for producing cigarettes,

FIG. 2

a view corresponding to arrow A in Figure 1,

FIG. 3

a diagram of the course of the forces acting on the cigarette machine over time in the individual compensatory measures,

FIG. 4

a diagram of the course of the forces acting on the cigarette machine moments over time in the individual compensatory measures.

Figures 1 and 2 show a strand guide 1 with two tubes 2, 3 for each cigarette rod 4 and 6, with a drive 7 and with a support (carrier) 8 in a otherwise not shown two-strand cigarette manufacturing machine 5, such as in the cigarette industry known type "PROTOS 2" of the applicant. The aforementioned components are parts of a cutting device 9, in the known manner, the continuously formed and moved to the cutting device cigarette strands 4, 6 in strand pieces, namely cigarettes of single or multiple length, are cut. The usual cutting device 9 is covered with a circumferential (arrow 13) housing 12 and carries at least one blade 14 which is gimbals mounted so that the knife during a cutting process in which it is passed through gaps 16 in the tubes 4, 6 , a movement component in the conveying direction of the cigarette rods 4, 6 (arrow 17) has -. The motion component corresponds to the strand velocity. In addition, the knife is held perpendicular to the cigarette rods during the cut.

The tubes 2 and 3 are fastened by means of a tube holder 21 at one end 18 of the support 8 (also called rocker arm), which has three leaf springs 22, 23 and 24 made of carbon-fiber-reinforced synthetic resin (eg eproxide resin). The leaf springs 22, 23 leave a gap 26 between them, through which a connecting rod 27 (connecting rod) of a crank mechanism 7 for the tubes 2 and 3 passes, which is mounted at its one end 28 on a pin 29 in the tube holder 21. The leaf spring 24 is the leaf springs 22, 23 arranged opposite. All leaf springs are attached at their end remote from the tube holder 21 end 31 to a leaf spring holder 32.

The crank rod 27 of the crank mechanism 7 is mounted with its other end 33 on a crank pin 34 of a crank 36. The crank pin 34 is eccentric to a driven by a motor 38 drive shaft 37 with the axis of rotation 40 of Crank 36 is arranged. The crank 36 is provided with a so-called first balancing mass 41, which reduces a part of the first-order mass forces. Since the crank axis of rotation is not in the main plane of movement of the tubes and for structural and sectional reasons there can not be and should, for the transmission in this way no particularly good mass balance possible.

In order to improve the mass balance of the tube drive a second balancing mass 42 is provided according to the invention, the center of gravity 45 has a certain distance x from the rotation axis 43 of a shaft 44 (balance shaft), which drives the second balancing mass 42 to circulations. The center of gravity of the second balancing mass 42 is advantageously in the plane of the center of gravity of the crankshaft 36 located first balancing mass 41. In horizontally guided tubes is a vertical plane in which the focus of the balancing weights lie. The shafts 44 and 37 are, for. B. by means of a toothed belt 46, kinematically connected to each other so that they rotate synchronously. d. H. have equal speeds -. Their directions of rotation are opposite. With 39 a toothed disk for deflecting the toothed belt 46 is designated. With this second balancing mass 42, the mass forces remaining after the partial mass balancing with the aid of the first balancing mass 41 can additionally be significantly reduced. This also applies to the mass moments introduced into the machine and the floor.

According to the invention, the mass balance can be further improved by a third balancing mass 48 which is driven by the drive shaft 37 of the crank 36 to rotate. The third balancing mass 48 is arranged at an axial distance from the first balancing mass 41 and has a different angular position from this.

In a drive of the cutting device 9 by the motor 38, the connecting rod 27 of the crank mechanism 7 performs reciprocating movements accordingly

Double arrow 49 off. The tubes 2 and 3 perform corresponding reciprocating linear movements. During the linear movement of the tubes in the direction of movement 17 of the cigarette rods 4 and 6, the knife 14 is also moved in the direction 17 at this time and additionally passed through the space 16 in the tubes 2 and 3, where it performs a separation cut through the strands.

The diagram of Figure 3 shows at a length of the cut strand pieces of 130 mm and for a number of strokes (reciprocations) of the tubes 2 and 3 of 3500 the time course of the forces K in Newton on the cigarette rod machine 5 during a reciprocating motion the tubes.

The drawn-out curve a shows the flow of forces without any mass balance.

The dashed curve b shows the flow of force at a mass balance with a balancing mass 41st

The dot-dash line curve c, d shows the flow of force at a mass balance by means of an additional second balancing mass 42 and possibly a third balancing mass 48 according to the invention.

From the diagram shows that the mass balance by means of a second and possibly third balancing mass 42, 48 has a significant reduction in the forces result, which can be up to 70% compared to the state with only one balancing mass 41.

The diagram of Figure 4 shows at a length of the cut strand pieces of 130 mm and at a stroke rate (reciprocating movements) of the tubes. 2 and 3 of 3500 the time course of the moments M in Newton-millimeters on the cigarette rod maker. 5

The solid curve a shows the torque curve without any mass balance.

The dashed curve b shows the torque curve in a mass balance by means of a balancing mass 41st

The dotted curve c shows the torque curve in a mass balance by means of a balancing mass 42.

The dash-dotted curve d shows the torque curve in a mass balance by means of a second and a third balancing mass 42 and 48, respectively.

From the diagram shows that the mass balance by means of a second and third balancing mass 42, 48 has a significant reduction in the moments result, which can be up to 40% compared to the state with only one balancing mass 41.

Claims (13)

1. Method for cutting at least one endless moving strand of the tobacco-processing industry into rod-like single articles by means of a rotating knife, whereby the strand is supported by a strand guide which is driven in reciprocating motion by a drive, preferably a crank drive, the unbalanced mass of the crank drive being partially compensated by a first counterweight rotating with the crank drive, characterised in that a second counterweight is driven in rotary motion synchronously with the first counterweight by a shaft arranged at a distance from the crank drive.
2. Method according to claim 1, characterised in that a third counterweight driven by the crank drive is driven in rotary motion synchronously with the first counterweight.
3. Device for cutting at least one endless moving strand of the tobacco-processing industry into rod-like single articles by means of a rotating knife, comprising at least one strand guide supporting the strand and driveable synchronously with the knife by a crank drive, a crank rod being journalled at one end on a crank pin arranged eccentrically with respect to the drive shaft of the crank and being connected at the other end to a support carrying the strand guide, and a first rotating counterweight located in the region of the crank or its drive, characterised in that there is provided a second counterweight (42) which rotates about an axis (43) located at a distance from the axis (40) about which the first counterweight (41) rotates.
4. Device according to claim 3, characterised in that the support (oscillating link) (8) is formed by flexible support elements (22...24).
5. Device according to claim 4, characterised in that the oscillating link (8) is formed by leaf springs (22...24).
6. Device according to one or more of the preceding claims 3 to 5, characterised by a second balancer shaft (44) driving the second counterweight (42) in synchronous rotation and arranged at a distance from the drive shaft (37) of the crank (36).
7. Device according to one or more of claims 3 to 6, characterised in that the drive shaft (37) of the crank (36) and the balancer shaft (44) arranged at a distance therefrom are connected kinematically to one another by means of a toothed drive, preferably a toothed belt (46).
8. Device according to one or more of claims 3 to 7, characterised in that the balancer shaft (44) and the drive shaft (37) of the crank (36) rotate in opposite directions.
9. Device according to one or more of claims 3 to 8, characterised in that a third counterweight (48) is kinematically connected to the drive shaft (37) of the crank (36).
10. Device according to claim 9, characterised in that the third counterweight (48) is driven by the drive shaft (37) of the crank (36).
11. Device according to claim 9 and/or 10, characterised in that the third counterweight (48) is arranged at an axial distance from the first counterweight (41) and is rotationally offset with respect thereto.
12. Device according to one or more of claims 9 to 11, characterised in that the centre of gravity (45) of the second counterweight (42) and the centre of gravity of the first counterweight (41) are located in a vertical plane.
13. Device according to one or more of claims 3 to 12, characterised in that the strand guide (1) includes two guide tubes (2, 3) fixed to the oscillating link (8).

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