EP2746167A1 - Deep draw packaging machine with hoisting gear powered by an electric motor - Google Patents

Abstract

The machine (1) has an electromotive lifting gear (30) for lifting a forming station (2), a sealing station (3) and a cutting station (4) and comprising two carriages that are mounted in vertical guides, and a tool connected to the carriages. A collision region of the tool is defined by lifting motion of the tool between lower position and upper position. Two lifting spindles i.e. thread rolling spindles, are arranged parallel to the vertical guides and outside the collision region of the tool. A lifting rail is provided by which the tool is connected to the carriages.

Description

The invention relates to a thermoforming packaging machine according to the preamble of claim 1.

It is from the DE 42 16 210 A1 a pneumatic Kniehebelhubwerk for a thermoforming packaging machine is known in which all the drive components and the toggle mechanism are arranged below the movable tool. In thermoforming packaging machines, the working height or sub-sheet conveying level is at a height of approximately 900 mm above the ground. At such a working height and with a toggle lever troughs with a maximum draw depth of about 200 mm can be produced.

From the US 5,205,110 An electromotive hoist for a thermoforming packaging machine is known, in which an electric motor in the production direction following a forming station and outside the range of movement of a mold base is arranged and the mold lower part is raised and lowered by means of the hoist. By means of drive belt, the drive energy of the electric motor is transmitted to a connecting rod, which in turn converts its rotational movement into a vertical movement of the mold lower part by means of a slotted guide. In this case, the connecting rod is moved to a dead center position, in which the lower mold part is in its working position to accommodate high closing forces in cooperation with the upper mold part can.

From the DE 10 2008 023 319 A1 is a hoist for a tray sealing machine is known, wherein the hoist has two spindles, which are driven by a toothed belt by a servo motor. All drive and transmission components are located below the sealing tool base.

Hoists according to the known state of the art have the disadvantage that the stroke is severely limited by an arrangement of drive components below a tool to be moved vertically or that the tool to be moved can not be held in any position so as to occur with the cooperating upper tool To be able to absorb closing forces in the form of holding forces.

Object of the present invention is to provide an electric motor hoist for a thermoforming packaging machine with extended stroke and flexible positioning.

This object is achieved by a thermoforming packaging machine, comprising an electromotive hoist with the features of claim 1. Advantageous developments of the invention are specified in the subclaims.

The thermoforming packaging machine according to the invention comprises an electromotive hoist for a forming, sealing and / or cutting station, the hoist having two carriages and a tool connected to the carriage and the carriages are mounted in vertical guides, and wherein a collision area by the lifting movement of the tool is defined between a lower and an upper position. More specifically, the collision area defines itself as the integral of all spatial positions that the tool can occupy or sweep in a movement from the lower to the upper position (or vice versa). The invention is characterized in that the hoist comprises at least two lifting spindles, which are arranged parallel to the guides and in plan view outside the collision region of the tool. Thus, the transmission components such as a toggle lever below the tool can be omitted and the hub can be extended downwards to the bottom surface without raising the working height of the thermoforming packaging machine thereby.

Preferably, the lifting spindles threaded or spindles trapezoidal spindles, for example, with a pitch of 10 mm per revolution, on the one hand to achieve a high adjustment speed and on the other hand to allow a large lifting force or holding force.

The lifting spindles are preferably covered by telescopic springs to meet high hygiene requirements, for example in the medical or food sector, since some machine parts are cleaned with cleaning agents and thus this type of full coverage for movable machine parts provides the best possible protection.

Preferably, the hoist brakes that lock the lifting spindles to allow high holding forces acting from a tool shell on the movable tool by the occurring and required closing forces. For example, at the forming station, the mold top and the mold bottom have to be the film pinch all around and withstand a high mold pressure of up to 6 bar. The large weight of the movable mold lower part plays an additional role.

In an advantageous embodiment, the lifting spindles can be driven via a belt drive by means of an electric motor. In this case, the electric motor is preferably a servo motor in order to enable both high adjustment speeds, as well as a high positioning accuracy of the tool. This design allows a very flat design and thus a small footprint below the movable tool. The high positioning accuracy also allows the processing of different film thicknesses, since the torque and thus the holding force of the movable tool in each position is adaptable, which also small differences in thickness of the film can be compensated below 50 microns.

The belt drive preferably has a toothed belt in order to transmit the torque of the electric motor to the lifting spindles, thereby also synchronizing the lifting spindles relative to each other.

The hoist includes in an advantageous embodiment, a fixed and a movable connection unit for external media, such as vacuum or exhaust air. The advantage lies in a stationary supply of media to the fixed connection unit, so that these lines are not subject to movement. The movable connection unit is mounted on the lifting rail or on the tool and cooperates with the fixed connection unit in an upper working position, in which also the movable tool cooperates with a stationary upper tool part of the respective workstation. Both the tools, as well as the terminal units seal each airtight.

Preferably, the fixed terminal unit is mounted on the hoist such that it cooperates with the movable terminal unit in the working position of the tool to connect a medium by means of both terminal units with the tool. Thus, none of the media lines is subject to any movement that would adversely affect the life of the line.

The connection units preferably each have a contact surface which is inclined with respect to the direction of movement of the lifting movement of the lifting mechanism and which has a contact surface in the production direction short design of the connection units with a respect to a perpendicular to the lifting movement aligned contact surface allows.

The hoist preferably has a stroke of more than 300 mm, in particular more than 400 mm.

It is expedient if the movable tool can be positioned not only in an upper and a lower position, but additionally in a tool change position. In this position, the tool can be particularly easily accessible, which improves the handling of the packaging machine, in particular with regard to a tool change.

Preferably, the lifting spindles are each provided between two guides arranged in a direction of production in order to allow a uniform distribution of the lifting forces and holding forces and to minimize transverse forces on the guides.

Fig. 1

eine schematische Seitenansicht einer erfindungsgemäßen Tiefziehverpackungsmaschine,

Fig. 2

eine Einzelansicht eines Hubwerkes der Formstation in offener Stellung,

Fig. 3

eine Einzelansicht des Hubwerkes der Formstation in geschlossener Stellung und

Fig. 4

eine Einzelansicht des Riemengetriebes des Hubwerkes von unten.

In the following, an advantageous embodiment of the invention is explained in detail with reference to a drawing. In detail show:

Fig. 1

a schematic side view of a thermoforming packaging machine according to the invention,

Fig. 2

a single view of a hoist of the forming station in the open position,

Fig. 3

a single view of the hoist of the forming station in the closed position and

Fig. 4

a single view of the belt drive of the hoist from below.

The same components are provided throughout the figures with the same reference numerals.

Fig. 1 shows a schematic view of a thermoforming packaging machine 1 according to the invention. The thermoforming packaging machine 1 has a forming station 2, a sealing station 3, a cross-cutting device 4 and a longitudinal cutting device 5, which are arranged in this order in a production direction R on a machine frame 6 are. On the input side is located on the machine frame 6, a feed roller 7, from which a film 8 is withdrawn. In the region of the sealing station 3, a material reservoir 9 is provided, from which a cover film 10 is drawn off. On the output side, a discharge device 13 in the form of a conveyor belt is provided on the thermoforming packaging machine, with which finished, isolated packages are transported away. Furthermore, the thermoforming packaging machine 1 has a feeding device, not shown, which grips the film 8 and transports it further per main working cycle in the production direction R. The feed device can be designed, for example, by transport chains arranged on both sides.

In the illustrated embodiment, the forming station 2 is formed as a thermoforming station, are formed in the film 8 by deep drawing troughs 14. In this case, the forming station 2 can be designed such that in the direction perpendicular to the production direction R several troughs are formed side by side. The forming station 2 has a hoist 30 to a mold lower part or a tool 32 (see Fig. 2 ) to move upward against a mold top 47 in a working position for the molding process. In the production direction R behind the forming station 2, an insertion path 15 is provided in which the troughs 14 formed in the film 8 are filled with products 16.

The sealing station 3 also has a hoist 30 and a closable chamber 17, in which the atmosphere in the wells 14 can be replaced with a replacement gas or with a gas mixture prior to sealing, for example, by evacuation or gas purging.

The cross-cutting device 4 also comprises a lifting mechanism 30 and is designed as a punch which cuts through the film 8 and the cover film 10 in a direction transverse to the production direction R between adjacent depressions 14. In this case, the cross-cutting device 4 operates such that the film 8 is not separated over the entire width, but is not severed at least in an edge region. This allows a controlled onward transport by the feed device. The cross-cutting device 4 also has a hoist 30.

The longitudinal cutting device 5 is formed in the illustrated embodiment as a knife assembly, with which the film 8 and the cover sheet 10 between adjacent Trays 14 and at the lateral edge of the film 8 are severed, so that behind the longitudinal cutting device 5 individualized packages are present.

The thermoforming packaging machine 1 also has a controller 18. It has the task to control the processes running in the thermoforming packaging machine 1 processes and monitor. A display device 19 with operating elements 20 serves to visualize or influence the process sequences in the packaging machine 1 for or by an operator.

The general operation of the packaging machine 1 will be briefly described below.

The film 8 is withdrawn from the feed roller 7 and transported by the feed device in the forming station 2. In the forming station 2 troughs 14 are formed in the film 8 by deep drawing. The troughs 14 are transported along with the surrounding area of the film 8 in a main working cycle to the insertion path 15 in which they are filled with products 16.

Subsequently, the filled wells 14 are transported together with the surrounding area of the film 8 in the main working cycle by the feed device in the sealing station 3. The lidding film 10 is transported on to the foil 8 with the advancing movement of the film 8 after a sealing operation. In this case, the lidding film 10 is withdrawn from the material storage 9. The sealing of the lidding film 10 on the troughs 14 results in sealed packages which are separated in the following cuts 4 and 5 and transported out of the thermoforming packaging machine 1 by means of the discharge device 13.

Fig. 2 shows the hoist 30 in an open position, in which the movable tool 32 is in its lowermost position, with a bracket 31, on both sides of the tool 32 in the production direction R seen right and left two guides 33 are mounted, wherein the Guides 33 are connected at their upper ends with brackets 34. By means of the carrier 34, the hoist 30 is attached to the machine frame 6 in the thermoforming packaging machine 1. In each case, a carriage 35 is vertically movable on the guides 33 and two carriages 35 are connected to each other via a lifting rail 36 which is aligned transversely to the production direction R. To the carriage 35, a spindle nut 37 is integrated, by means of which a stroke H of the lifting rail 36 is provided. In each case a lifting spindle 38 is provided centrally between the guides 33. The rotation of the lifting spindle 38 causes a vertical lifting movement H of the spindle nut 37 and thus of the carriage 35 and the lifting rail 36. The lifting spindle 38 is connected both between the bracket 31 and the carriage 35, as well as between a transverse strut 40 and the carriage 35 by means of a Telescopic spring 39 completely covered. The lifting spindle 38 can be locked by means of a brake 41 provided on the transverse strut 40.

The lifting rail 36 serves to receive the tool 32, which is made in three parts in this exemplary embodiment and has a drawing depth of 350 mm. At the cross struts 40 is a fixed connection unit 42 and on the lifting rail 36, a movable connection unit 43 is attached. The movable connection unit 43 has a relation to the lifting movement H of the hoist 30 by 30 ° to 60 ° inclined contact surface 44 with a through hole 45, wherein the through hole 45 is connected via not shown passages in the lifting rail 36 with the tool 32. The inclination of the contact surface 44 of the fixed terminal unit 42 is provided in accordance with the stroke H to the inclination of the contact surface 44 of the movable terminal unit 43. On the fixed connection unit 42 are media supply or disposal lines 46, for example, for vacuum or exhaust air attached.

In the upper area of the lifting mechanism 30, a tool upper part 47, in this case in particular a mold upper part, is arranged on the supports 34, and a servo-motor stamping device 48 with one or more stamps supports the molding process for forming the molds 14 in the film 8.

Fig. 3 shows the hoist 30 in the closed position, in which the tool 32 is in its uppermost position, which is also its working position. Here, the film 8 is clamped between the tool 32 and the upper die 47 and the two terminal units 42, 43 cooperate sealingly with their contact surfaces. The lifting movement H of the tool 32 and the space required for this movement define a collision area K. The tool 32 can also be positioned in other positions in which the tools 32, 47 or the connection units 42, 43 do not cooperate in each case. This may for example be a position at which a change of the tool 32 in or against the direction of production R or can be done upwards. In the working position of the tool 32 can the brakes 41 are activated to lock the spindles 38. Thus, the tool 32 can absorb very high closing forces, which are generated by the tool upper part 47 and molding pressures within the tools 32, without the clamping of the film 8 being canceled or the tools 32, 47 no longer being sufficiently sealed.

Fig. 4 shows a belt transmission 49 of the hoist 30 from below. The belt transmission 49 comprises a drive belt 50, which may be designed as a toothed belt with segmented slots for noise reduction, each having a pulley 51 at the lower ends of the lifting spindles 38, a guide roller 52 and a drive pulley 53. Parallel to the lifting spindles 38 aligned and on the Console 31 mounted servomotor 54 drives via the drive pulley 53, the belt drive 51 and thus generates the vertical stroke H of the tool 32. For a hygienic design of the lifting mechanism 30 also provides a cover 55 on the belt transmission 51 to protect it from contamination from above , Likewise, a chain or other type of belt can alternatively be used.

In the thermoforming packaging machine according to the invention, the lifting spindles 38 of the lifting mechanism 30 are arranged in plan view outside the collision area K of the tool 32. This means that the lifting spindles 38 are not arranged below the tool 32, but, measured in the direction of production R, before or after the tool 32 and / or laterally next to the tool 32. The top view of the hoist 30 takes place in the same direction as the lifting movement of the hoist 30, d. H. usually in the vertical direction.

As already explained, the hoist 30 may be provided for the forming station 2, for the sealing station 3 or for the cutting station 4. At the forming station 3, the moving tool 32 would be a forming tool, usually a forming tool base. At the sealing station 3, the movable tool 32 would be a sealing tool, usually a sealing tool lower part. When using the lifting mechanism 30 for the cutting station 4, the tool 32 would be a knife or counter knife, which is usually carried by a carrier, for example the lifting rail 36. In such a cutting station 4, the knife or counter blade, which is assigned as a tool upper part 47, a complementary counter blade or knife, usually smaller spatial dimensions than the carrier or the lifting rail 36. For the For the purpose of defining the collision area K, the knife and its carrier (for example, the lifting rail 36) can therefore be considered jointly as a "tool (32)" at a cutting station. Thus, the collision area K is the entire area that is swept by the movement of the hoist 30 from the knife and the carrier.

At the sealing station 3, the upper tool part 47 is designed as a sealing tool upper part and there is no servomotor stamp unit provided.

Embodiments of the lifting mechanism 30 are also conceivable which comprise six, eight or more guides 33 and four, six or more lifting spindles. Furthermore, a belt transmission 49 is conceivable in which the drive belt 50 runs outside the guides 33 and over four deflection rollers 52 at all four corners of the lifting mechanism 30 in order to be able to arrange the lifting rail 36 even further downwards.

To allow even larger strokes H, the working height of the machine 1 (i.e., the plane for transporting the film 8) and thus the machine frame 6 can be increased.

Claims (15)

Thermoforming packaging machine (1), comprising an electromotive lifting mechanism (30) for a forming (2), sealing (3) and / or cutting station (4), wherein the lifting mechanism (30) comprises two carriages (35) and one with the carriages ( 35) associated tool (32) and the carriage (35) are mounted in vertical guides (33), and a collision area (K) by the lifting movement (H) of the tool (32) between a lower and an upper position is defined characterized in that the lifting mechanism (30) comprises at least two lifting spindles (38) which are arranged parallel to the guides (33) and outside the collision area (K) of the tool (32). Thermoforming packaging machine according to claim 1, characterized in that a lifting rail (36) is provided, by means of which the tool (32) is connected to the carriage (35). Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting spindles (38) are threaded spindles. Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting spindles (38) are covered by means of telescopic springs (39). Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting mechanism (30) brakes (41) which can lock the lifting spindles (38). Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting spindles (38) can be driven via a belt drive (49) by means of an electric motor (54). Thermoforming packaging machine according to claim 6, characterized in that the electric motor (54) is a servomotor. Thermoforming packaging machine according to claim 6 or 7, characterized in that the belt transmission (49) has a toothed belt (50). Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting mechanism (30) comprises a fixed and a movable connection unit (42, 43) for external media. Thermoforming packaging machine according to claim 9, characterized in that the movable connection unit (43) on the lifting rail (36) or on the tool (32) is mounted. Thermoforming packaging machine according to claim 9 or 10, characterized in that the fixed connection unit (42) is mounted on the lifting mechanism (30) in such a way that it cooperates with the movable connection unit (43) in the working position of the tool (32) to convey a medium by means of both Connect terminal units (42, 43) with the tool (32). Thermoforming packaging machine according to one of claims 9 to 11, characterized in that the connection units (42, 43) each have a relative to the direction of movement of the lifting movement (H) of the lifting mechanism (30) inclined contact surface (44). Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting mechanism (30) has a stroke of more than 300 mm. Thermoforming packaging machine according to one of the preceding claims, characterized in that the tool (32) is positionable in addition to the upper and lower position in a tool change position. Thermoforming packaging machine according to one of the preceding claims, characterized in that the lifting spindles (38) are each provided between two guides (33) arranged adjacently in a production direction (R).

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