TUBULAR BAG MACHINE FOR FILLING A PRODUCT

Abstract

The invention relates to a tubular bag machine for filling a product into bags (9), comprising a vertical filling tube (2), a transverse sealing unit (3), a control unit (4) for controlling the tubular bag machine, and a sensor device (5) for detecting the product in the filling tube (2), which is designed to detect the product falling through the filling tube (2), wherein the sensor device (5) has a sensor (51) for emitting electromagnetic waves, and which is connected to the control unit (4), wherein the electromagnetic waves emitted by the sensor (51) remain in a detection space (E) which is confined to one region at the filling tube (2).

Description

BACKGROUND OF THE INVENTION

The present invention relates to a tubular bag machine for filling a product.

Vertical tubular bag machines are known in various designs from the prior art. Product elements of a product to be filled are hereby detected by a sensor device in order to ascertain the amount of product filled into the tubular bag. In so doing, sensors are used which emit electromagnetic waves, such as, e.g., in the X-ray or microwave range, and are disposed along the vertical fall distance on the outside of the filling tube. Such a tubular bag machine is, e.g., known from the German patent specification DE 10 2006 013 663 A1. In this case, it is particularly disadvantageous that different electromagnetic field geometries result as a function of the diameter of the filling tube used, of the electromagnetic wave length emitted and of the coupling of the sensor on the side of the tubular bag machine. As a result, the sensor detects not only a large section of the vertical fall distance but even possibly detects objects outside of the filling tube.

SUMMARY OF THE INVENTION

The tubular bag machine according to the invention has in contrast the advantage that a sharp delimitation of the detection region of the sensor is thereby implemented; thus enabling products falling past the sensor to be detected with greatly improved precision. The radiation is confined to a detection space in the filling tube. According to the invention, this results from the fact that the tubular bag machine comprises a vertical filling tube, a transverse sealing unit, a control unit for controlling the tubular bag machine and a sensor device for detecting the product in the filling tube, which is designed to detect the product falling through the filling tube. To this end, the sensor device comprises a sensor for emitting and detecting electromagnetic waves, said sensor being connected to the control unit. The electromagnetic waves emitted by the sensor thereby remain in a detection space which is confined to one region at the filling tube. As a result, the detection space is for the most part independent of the sensitivity, power output as well as the transmission frequency of the sensor. Cost effective sensors can thus be used because the quality requirements, e.g. with regard to antenna characteristics, directionality, side lobes and manufacturing tolerances, are substantially lower. In addition, an identical sensor can be used for different diameters of the filling tube.

The detection space is preferably delimited by at least one first absorber element and a second absorber element, which are disposed at the filling tube so as to be axially spaced from each other. By the positioning of the absorber elements, which are, for example, manufactured from a ferrite/plastic composition or a carbon filled plastic, in the direction of fall above and below the detection space, the electromagnetic waves are prevented from spreading further in the filling tube and the measurement region of the sensor is thereby delimited in an upward and downward direction. As a result, a volume of the detection space can further be defined which is adapted to the electromagnetic waves used as well as to the nature of the product to be filled. In so doing, a precise detection and an optimized machine control can be achieved.

According to a preferred embodiment of the invention, the two absorber elements are designed to completely run around the filling tube. As a result, an operationally reliable absorption of the electromagnetic radiation is achieved.

In a further preferable manner, the absorber elements are disposed in the interior of the filling tube, in particular integrated into said filling tube. In particular, the absorber elements do not protrude from an inner wall of the filling tube. In so doing, a particularly compact design can be achieved which has a uniform diameter and does not obstruct the products falling through the filling tube.

According to a preferred embodiment of the invention, the detection space is cylindrical. Optimal reflection properties are thereby created which also permit the use of cost effective sensors without special quality requirements or manufacturing tolerances for precisely detecting all of the product elements.

An intermediate region is preferably configured between the absorber elements as a metallic reflector for the electromagnetic waves emitted by the sensor. As a result, a homogenous field distribution and therefore a uniform detection sensitivity is achieved for the electromagnetic waves spreading between the absorber elements due to reflections.

In addition, the reflector is preferably one piece or embodied so as to be divided up into a plurality of segments; or the reflector is an inside wall region of the filling tube. Depending on the type of application or the nature of the product to be filled, an operationally reliable detection of all of the product elements falling through the detection space can thus be assured. Furthermore, a separate receiver is therefore not required, whereby a cost efficient minimization of the number of components results.

According to a preferred embodiment of the invention, a plurality of absorber elements is disposed in each case, starting at the detection space, in the axial direction of the filling tube. In so doing, an operationally reliable absorption of the entire electromagnetic radiation is variably facilitated for differing electromagnetic wave ranges. In addition, sensors having variable sensor frequencies can thereby be used.

The sensor is furthermore preferably disposed in a wall of the filling tube, preferably flush with an inner wall of the filling tube. In so doing, a particularly compact design is achieved without impairing the performance and the sensitivity of the sensor. Moreover, the sensor can be replaced in a simple manner without a great deal of installation work or costs.

According to a preferred embodiment of the invention, the sensor has a dimension in the axial direction of the filling tube, which dimension is equal to or greater than a distance in the absorber elements in the axial direction. An operationally reliable detection of all of the product elements along the entire fall line thereof in the detection space is facilitated having larger adjustment tolerances of the sensor antenna.

The filling tube is preferably formed from a plurality of different materials. This allows for a simple production of the filling tube, e.g. by means of a combination of individual parts connected to one another in modular design in a time and cost efficient manner.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the invention is described below in detail with reference to the accompanying drawings. In the drawings:

FIG. 1 shows a schematic sectional view of a tubular bag machine according to a preferred exemplary embodiment of the invention;

FIG. 2 shows a schematic longitudinal sectional view of a filling tube section comprising a sensor device; and

FIG. 3 shows a schematic sectional view along an intersection line 1-1 of FIG. 2.

DETAILED DESCRIPTION

A tubular bag machine for filling a product according to a preferred exemplary embodiment is described below in detail with reference to FIGS. 1 to 3.

FIG. 1 shows a schematic sectional view of a tubular bag machine 1 for filling a product according to a preferred exemplary embodiment of the invention. The tubular bag machine 1 comprises a filling funnel 8, in which a product to be filled is delivered in portions, in a direction of fall A, to a vertical filling tube 2 attached thereto. A packaging material delivered cyclically is formed around the filling tube 2 into an elongated packaging material tube 7 by means of a forming shoulder 6, said packaging material tube being welded by a longitudinal sealing unit (not depicted here) using a longitudinal sealing seam in the longitudinal direction. The tubular bag machine 1 further comprises a transverse sealing unit 3 having horizontal first and second sealing jaws 31, 32 which are disposed at an end of the filling tube 2 that is opposite to the filling funnel 8. The transverse sealing unit 3 initially seals a foot seam on the packaging material tube 7, which has been molded and cyclically delivered. After a portion of the product has fallen into said packaging material tube and the filled tube section has been moved downwards, the packaging material tube 7 is sealed by means of a head seam to form a closed bag 20, wherein the foot seam of the succeeding packaging is also simultaneously sealed.

In addition, a sensor device 5 disposed in the filling pipe 2 is provided, said sensor device detecting the product elements 11 of the product being filled which fall through the filling tube 2. The sensor device 5 comprises a sensor 51 which is disposed in a wall 20 of the filling tube 2 and is connected via a cable 14 to a control unit 4 for controlling the tubular bag machine 1, the former being disposed outside of the filling pipe 2 and above the forming shoulder 6. Provision is hereby made to embed the cable 14 in the wall 20 or to alternatively design said cable as flat cable which runs on the inside of the filling tube 2 and does not impair a flow capacity of the product falling through said filling tube. The sensor 51 is disposed substantially flush with an inside wall of the filling tube 2.

The sensor 51 emits electromagnetic waves into a cylindrical detection space E which is delimited to a region at the filling tube 2 by a first absorber element 54 and a second absorber element 55 which are disposed in the direction of fall A above or, respectively, below the sensor 51.

As is illustrated in FIG. 2, the sensor 51 has a dimension B in an axial direction X-X of the filling tube 2, which dimension is greater than a distance C between the absorber elements 54 and 55. The sensor 51 emits electromagnetic waves, which are indicated schematically in FIG. 2 by circular segment type lines L, into the cylindrically shaped detection space E.

The electromagnetic waves are reflected by an inside wall region of the filling tube 2, which is situated between the absorber elements 54, 55 and is designed as a metallic reflector 21, and received by the sensor 51. Each product element 11 detected in the detection space E causes a signal change in the electromagnetic waves received at the sensor 51, said signal change being transmitted via the cable 14 to the control unit 4 that is not visible in FIG. 2. The reflector 21 can also alternatively be designed so as to be divided into a plurality of segments in the circumferential direction.

The first and second absorber elements 54, 55 absorb the electromagnetic waves in the axial direction X-X of the filling tube 20. The absorber elements 54, 55 are designed in a completely circumferential manner in the interior of the filling tube 2, in particular integrated into said filling tube 2, as is illustrated in sectional view at a line of intersection II-II of FIG. 2 for the second absorber element 55 that is visible in FIG. 3. A plurality of absorber elements, e.g. having different absorption properties, can also optionally be respectively disposed, starting from the detection space E, in the axial direction X-X of the filling tube 2; or the filling tube 2 can be formed from a corresponding plurality of different materials.

The tubular bag machine 1 according to the invention for a product thus has the advantage that a cylindrical detection space E is provided within the filling tube 2, wherein the former is spatially sharply delimited. Said detection space thus facilitates a significantly improved detection of all of the product elements 11 falling through the filling tube 2, which is for the most part independent of the sensitivity, power output, radiation pattern and transmission frequency of the sensor 51 as well as the diameter of the filling tube 2. Cost effective sensors having significantly lower quality demands can therefore be used. In addition, the radiation is confined to the detection space E in the filling tube 2.

Claims

1. A tubular bag machine for filling a product, comprising

a vertical filling tube (2),

a transverse sealing unit (3),

a control unit (4) for controlling the tubular bag machine, and

a sensor device (5) for detecting the product in the filling tube (2), which is designed to detect the product falling through the filling tube (2), wherein the sensor device (5) has a sensor (51) for emitting electromagnetic waves, and which is connected to the control unit (4), wherein the electromagnetic waves emitted by the sensor (51) remain in a detection space (E) which is confined to one region at the filling tube (2).

2. The tubular bag machine according to claim 1, characterized in that the detection space (E) is delimited by at least one first absorber element (54) and a second absorber element (55) which are axially spaced apart from one another at the filling tube (2).

3. The tubular bag machine according to claim 2, characterized in that the two absorber elements (54, 55) at the filling tube (2) are designed in a completely circumferential manner.

4. The tubular bag machine according to claim 2, characterized in that the absorber elements (54, 55) are disposed in the interior of the filling tube (2), in particular arc integrated into the filling tube (2).

5. The tubular bag machine according to claim 2, characterized in that the detection space (E) is cylindrical.

6. The tubular bag machine according to claim 2, characterized in that an intermediate region between the absorber elements (54, 55) is designed as a metallic reflector (21) for the electromagnetic waves emitted by the sensor (51).

7. The tubular bag machine according to claim 6, characterized in that the reflector (21) is designed as one piece.

8. The tubular bag machine according to claim 1, characterized in that a plurality of absorber elements is respectively disposed, starting at the detection space (E), in an axial direction (X-X) of the filling tube (2).

9. The tubular bag machine according to claim 1, characterized in that the sensor (51) is disposed in a wall (20) of the filling tube (2).

10. The tubular bag machine according to claim 1, characterized in that the filling tube (2) is formed from a plurality of different materials.

11. The tubular bag machine according to claim 2, characterized in that the absorber elements (54, 55) are integrated into the filling tube (2).

12. The tubular bag machine according to claim 6, characterized in that the reflector (21) is divided into a plurality of segments.

13. The tubular bag machine according to claim 6, characterized in that the reflector (21) is an inside wall region of the filling tube (2).