JPH0330244Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a device for detecting foreign objects caught in a seal in a food packaging machine, and is designed to reliably detect foreign objects caught in the seal and prevent the occurrence of defective seals. It is something. Furthermore,
Detected products with defective seals can be automatically discharged from the line.

Due to the special nature of food packaging, it is easy for the packaged product to generate debris, and it is inevitable that these minute debris will get caught in the area to be sealed (hereinafter referred to as the sealing area), resulting in a seal failure.

Conventionally, detection of foreign matter caught in the seal portion of such a food packaging machine has been carried out by operating a limit switch by directly or mechanically enlarging the displacement of the sealer.

However, such a method has the following drawbacks.

(a) Since a relatively large displacement is required to operate the limit switch, it could not be detected unless a large foreign object was caught.

(b) Packaging material connection part (for example, packaging material roll 1 in Figure 1)
Detection of seams between packaging materials itself
It was impossible for the same reason as (a).

(c) Even if a special limit switch that operates with minute displacements is used, it must be adjusted each time due to changes in packaging materials, changes in sealer conditions, etc.
It was complicated and hot.

(d) For reasons (a), (b), and (c), it was impossible to reliably detect defective products, so a skilled packaging inspector was required.

This invention is a device that can reliably detect minute displacements caused by foreign objects being caught in the seal portion, except for the above-mentioned drawbacks.

This invention will be explained below with reference to Examples.

FIG. 1 shows an overall schematic perspective view of a pillow type packaging device.

The packaging material 1, which is continuously supplied in the form of a sheet, is
After passing through the feeding roller 2, it is shaped by the bag making machine 5,
With the center sealer 6, both ends of the packaging material 1 are adhered to form a continuous cylindrical shape. On the other hand, the article to be packaged 3 is supplied at regular intervals by a supply chain 4 and is accommodated in this cylindrical packaging material. The cylindrical packaging material containing the object to be packaged 3 is adhesively cut into individual objects by a center sealer 6, an end sealer, and a cutter 7. According to this invention, foreign matter detection sensors 9 and 10 are installed in the center sealer 6, end sealer and cutter 7.
By setting up the sealer, a signal proportional or correlated to the displacement of the part of the package 3 that is in contact with the sealing surface is generated through each sealer, and this value is sent to a setting device (not shown in Fig. 1). The presence or absence of foreign matter caught in the seal is detected by comparing it with the set value. By using a setting device that has a sensor output display function, such as a meter relay, you can adjust the set value to the optimal value while checking the sensor output status displayed on the meter relay. It's good to do that. Furthermore, by combining the above device with a defective product discharge device, it becomes possible to automatically classify good products and defective products.

FIG. 2 illustrates the structure of a non-contact sensor detection device.

This is an example of the structure of a detection device in which a non-contact sensor is attached to a feed roller (not shown in FIG. 1).

The packaging material 1 shaped by the bag making machine is advanced in the direction shown by arrow A by the feed roller 27,
Sent to sealer 6. The feed roller 27 is driven by a drive shaft 30. The upper and lower rollers of the feed roller 27 are capable of narrowing the sealed portion of the packaging material 1 and opening around the fulcrum shaft 29, and are constantly pulled by the tension spring 28.

The non-contact type sensor 9 has a sensor support fitting 31
It is attached to the lower roller casing or the packaging machine body.

The displacement detection plate 32 is attached to the upper roller casing and faces the sensor across the gap 11. If a foreign object were to enter between the packaging materials and enter the feed roller, the gap between the upper and lower rollers would open, and at the same time, the gap between the displacement detection plate 32 and the sensor 9 would also open. This displacement is detected by a non-contact sensor.

Instead of the feed roller (drive roller) shown in Fig. 2, a touch roller (not shown) (a roller without a drive source, which, like the feed roller, opens its upper and lower rollers in response to foreign matter being caught) is used. You may also use the one that works for you.

In addition, in the case of FIG. 2, the non-contact type sensor 9 is placed at a position where the gap between the displacement detection plate 32 and the displacement detection plate 32 becomes large in case of a foreign object being caught. It may be arranged at a position where the gap between the two is small (for example, a non-contact type sensor is attached above the displacement detection plate 32). Also,
As for the output polarity of the non-contact type sensor, either one in which the output becomes larger as the gap becomes larger or one in which the output becomes smaller can be used. In short, whether the sensor output will be at a high level (positive characteristic) or low level (negative characteristic) in response to the increased development of the gap between the upper and lower rollers due to foreign matter getting caught depends on the detection mechanism and/or the output polarity of the sensor. Dependent.

Figure 3 shows the center sealer 6 in Figure 1.
FIG. 2 is a detection circuit block diagram when a non-contact type sensor 9 is used.

When the packaging material 1 is adhered by the heat and pressure of the sealer 6, a gap 11 is formed in the non-contact sensor 9.
A signal that is proportional or correlated to is generated. This signal is amplified and corrected by the signal processing circuit 12,
The value of the setting device 13 is compared with the comparator C, and if the value is greater than or equal to the set value (if the sensor output has a positive characteristic) or less than the set value (if the sensor output is a negative characteristic), there is a foreign object in the external signal generation relay 14. A display device 15 such as a buzzer or lamp that sends a jamming detection signal
make it work.

FIG. 7 is a sensor output diagram in which the signal from the non-contact sensor 9 is amplified by the signal processing circuit 12 and made linear (for convenience of explanation, with respect to increased displacement due to foreign matter being caught). .

When the seal part of the product is normal, a signal is generated with an almost constant amplitude, as shown by number 24.
When a foreign object is caught or a packaging material connection part passes, a large output is generated as shown by number 25. In this case, when the sensor output is equal to or higher than the setting value of the setting device 13, it is determined that there is an abnormality. In addition, number 26
The output shown by is the output when the packaging machine is stopped. As the non-contact sensor 9, any sensor can be used as long as it outputs a signal correlated to the distance to the object, such as an overcurrent loss type, photoelectric type, capacitance type, ultrasonic type, or laser type.

FIG. 4 is a detection circuit block diagram when a contact sensor 17 is used to detect the displacement of the sealer 6 either directly or through the signal transmission bar 16. As the contact type sensor, a differential transformer type, a magnetic type, etc. can be used.

It is desirable to be able to adjust the detection set value to an optimal value when packaging conditions such as the type of packaging material and packaging speed change, or when conditions change over time.

Therefore, if a meter relay or the like is used instead of the above-mentioned general setting device, the generated signal can be checked on the display section of the meter relay or the like, so that the adjustment can always be made to the optimum condition. To explain this with reference to FIG. 5, the signal processing circuit 12
By inputting the signal output from the meter to the meter relay 19, adjusting the upper limit (or lower limit) setting pointer while watching the meter deflection, and resetting, it is possible to always use the meter in the optimum condition. A digital comparator with a sensor output display function may be used in place of the meter relay. Alternatively, it may be a combination of a general adjustable setting device and a sensor output display device that displays the sensor output by blinking a plurality of lamps or by making a sound.

Although it is possible to combine each of the devices shown in FIGS. 3 to 5 with a packaged defective product discharging device, FIG. 6 shows an example in which the device is combined with the device shown in FIG. 5.
An abnormality occurring in the center sealer 6 or end sealer 7 is detected by the sensor 9 or 10, and the packaging defective product discharge device 21 is activated at the timing set by the timer 20, and the packaging defective product 23 is automatically discharged. Ru. An ordinary timer may be used, but it is better to have one that automatically changes the timing to an appropriate value in conjunction with the speed of the packaging machine.

As explained above, this invention brings about the following effects.

(1) It is possible to reliably detect even minute foreign objects that were previously undetectable.

(2) It becomes possible to detect packaging material connections that could not be detected conventionally.

(3) It becomes easier to readjust the sensor due to changes in packaging conditions, changes over time, etc.

(4) Automatic discharge of poorly packaged products becomes possible.

(5) This eliminates the need for a packaging inspector, who was conventionally required for each packaging machine, and at the same time greatly improves inspection accuracy, greatly contributing to labor savings.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic perspective view of a pillow-type packaging device to which this invention is applied, and FIG. 2 is a perspective view of the main part of the structure of a detection device using a non-contact type sensor. FIG. 3 is a circuit block diagram of an example of a device using a non-contact type sensor. FIG. 4 is a circuit block diagram of an example of a device using a contact type sensor. FIG. 5 is a circuit block diagram of an example of a device using a meter relay. FIG. 6 is a circuit block diagram of an example of a device combined with a device for discharging defective packaging products. FIG. 7 is an output diagram of the sensor. 1... Packaging material, 2... Feeding roller, 3... Item to be packaged, 4... Supply chain, 5... Bag making machine, 6
... Center sealer, 7 ... End sealer and cutter, 8 ... Conveyor, 9 ... Center seal foreign object detection sensor, 10 ...
End seal foreign object detection sensor, 11...
... Gap, 12 ... Signal processing circuit, 13 ... Setting device, 14 ... External signal generation relay, 15 ... Display device, 16 ... Signal transmission bar, 17 ... Contact type sensor, 19 ... Meter Relay, 20...
Timer, 21... Packaging defective product discharge device, 22...
...Product, 23...Discharged defective packaging product, 24...
...Sensor output when the product is normal, 25...Sensor output when a foreign object is caught, 26...Sensor output when the packaging machine is stopped, C...Comparator.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a food packaging machine, a sensor that generates a signal that is proportional to or correlated with the displacement of a portion of the sealer, feed roller, touch roller, etc. that is in contact with the sealing surface; a setting device having a set value to be compared with the output from the sensor;
A device characterized in that a seal part foreign object detection signal is output based on the magnitude of the output from the sensor and the setting value of the setting device. (2) Utility Model Registration Scope of Claims In the device according to claim 1, a meter relay is used as the setting device, and the set value of the meter relay is determined by checking the output state from the sensor displayed on the display section of the meter relay. A device characterized by being able to adjust to an optimal value. (3) Utility Model Registration The device according to claim 1, characterized in that a digital comparator having a sensor output display function is used as the setting device. (4) Utility model registration The device according to claim 1 is provided with a sensor output display device that displays the sensor output, and the setting device is configured by checking the output state from the sensor displayed on the display device. A device characterized by being able to adjust values. (5) A device according to any one of claims 1 to 4 of the claims for utility model registration, characterized in that it is equipped with a device for discharging defective packaging. (6) Utility Model Registration Scope of Claims In the device according to claim 1, a meter relay into which an output from a sensor is input is used as the setting device, and a seal part foreign object detection signal generated from the meter relay is used as the setting device. In response, a timer is provided that generates an output signal at a timing linked to the speed of the food packaging machine, and a packaged defective product discharge device is provided that discharges the packaged product in response to the output signal from this timer. Featured device.