DE19512124C2 - Device for checking bottles for deviations from the norm in the form of damage and / or foreign bodies, in particular for detecting residual liquids - Google Patents

Description

The device relates to a device for checking bottles Deviations from the norm according to claim 1.

Such a device is known for example from DE 41 27 686 A1.

In the known inspection machine, the measuring section runs through the bottom wall Glass and then any remaining liquid. That emanating from a light source Signal experiences damping, which from the bottom wall and any existing Residual liquid is caused.

The degree of damping now depends on the distance to be covered in the residual liquid and the transmission of the bottle bottom. The glass material from which the bottle bottom there may be a different transmission for each bottle. This Transmission can now fluctuate stochastically because the composition of the Batches of glass mass from which a number of bottles are then made are often differently. Especially with so-called stained glass with a certain proportion of Recycled glass will experience fluctuations in transmission.

As a disadvantage with the known inspection machine, it is to be seen that with the Examination of bottles for any residual liquid is now not clear It can be determined whether the attenuation of the transmission on the glass material or on the in the Bottle of residual liquid is caused.

An optical detection system that uses transmission as a decision criterion for a Sorting bottles used can often not distinguish whether the predefined limit value for the damping due to an individually high damping of the glass or is exceeded due to the presence of residual liquid.

It is therefore an object of the invention to provide a device in which a different, caused by different mixing of the glass material Transmission is compensated and so the reliable detection of even small amounts of Residual liquids is made possible.  

This problem is solved by the features of the main claim.

The invention adopts the knowledge that specific differences in the Damping the glass material of the bottle to be examined by another optical measurement the damping at a point on the bottle where no residual liquid is expected, are measurable and this damping as a correction value in the actual measurement the residual liquid can be taken into account.

The bottle neck has proven to be a suitable location for measuring the damping attributable to the respective glass material prove because in this area the probability of a residual liquid is extremely low and the manufacturing tolerances regarding Wall thickness of the bottle are low.

In this way it is possible for everyone - due to the different mixing ratios in the glass material - different bottles a uniformly accurate measurement with high Realize sensitivity to residual liquid.

If after taking into account the attenuation due to the respective glass material during the actual measurement Residual liquid a predetermined limit value is exceeded, then this is exceeded presumably caused by residual liquid in the bottle and leads to a sorting out the bottle in question.

The invention is explained in more detail below with reference to the figure and the list of reference symbols.

The bottle 1 to be examined is held during the examination by two holding elements 2 acting laterally on its side wall, suspended above the lighting unit 3 .

The bottom of the bottle 1 is inspected on the inside via a camera system 4 . The beam path has a special feature that it is crossed approximately in the neck area of the bottle, which makes it possible or easier to inspect even bottles with a comparatively narrow and / or long neck.

The camera system 4 is connected to a control unit 5 . Just below the mouth of the bottle 1 there is a measuring device 6 which consists of a light source 6 a and a light sensor 6 b.

The light emitted by the light source 6 a with a known intensity passes through the walls of the bottle 1 and is damped. Based on the intensity with which the light transmission of the bottle is incident on the light sensor 6 b determined.

The determined value for the transmission attributable to the glass material used is now forwarded to the control unit 5 .

This value is now used for the further assessment of whether contamination and / or Residual fluid considered.

It is by software to define another threshold possible either in the evaluation of the signals delivered by the camera system 4 or to vary the intensity of the illumination unit 3 so that the from the bottom 1 b of the bottle 1 emergent light quantity is constant.

It is of course also possible to combine both the software-based change in the response threshold and the intensity change in the lighting unit 3 .

During operation of the inspection device according to the invention, it can happen that dirt is deposited on both the light source 6 a and the light sensor 6 b. This causes a damping, which is not due to the transmission of the bottle just measured and could lead to an incorrect measurement result.

It is therefore provided that the measuring device 6 is calibrated cyclically by carrying out a reference measurement of the internal damping in the measuring device without a bottle. The transmission values of the measured bottles then always refer to the value of the last reference measurement.

Reference list

1

bottle

1

a neck area

2nd

Holding elements

3rd

Lighting unit

4th

Camera system

5

control

6

Measuring device

6

a light source

6

b Light sensor

Claims (3)

1. Device for checking bottles for deviations from the norm in the form of damage and / or foreign bodies, in particular for detecting residual liquids

• 1. an illumination device ( 3 ) which emits light rays through the area of the bottle ( 1 ) to be examined
• 2. a camera system ( 4 ) that detects these light beams
• 3. a further optical measuring device ( 6 ) which determines the degree of transmission of the bottle ( 1 ) to be tested, which is attributable to the respective glass material, in an area ( 1 a) which is considered to be error-free
• 4. a control unit ( 5 ) which includes the values measured by the camera system ( 4 ) and by the measuring device ( 6 ) in the calculation of the deviation from the norm and, if a predetermined limit value is exceeded, causes the bottles ( 1 ) to be sorted out.

2. Device according to claim 1, characterized in that the region ( 1 a) of the bottle to be tested which is considered to be error-free is the bottle neck. 3. Device according to claim 1, characterized in that the control device ( 5 ) changes the intensity of the lighting unit ( 3 ) in dependence on the transmission of the bottle ( 1 ) just measured, which is attributable to the respective glass material.