Abstract: In order to improve the range and accuracy of detecting aluminum foil defective cigarette packs during the production process of the GDX2 cigarette packaging unit, the capacitive proximity switch was replaced with a photoelectric type by improving the design of the No. 5 wheel detection device. Proximity switch, and an additional photoelectric proximity switch is added at an appropriate position on the back of the No. 5 wheel body cigarette pack to transmit the detection signals of the two proximity switches to the No. 6 wheel rejection module, thus realizing the four-step inspection of the No. 3 wheel when the equipment is running at high speed. Rejection of missing and damaged aluminum foil cigarette packets caused by the No. 4 wheel and No. 4 wheel entering the No. 5 wheel. The improved results show that it can effectively reduce the defective rate and market complaints, and improve product quality.

Keywords: No. 5 wheel detection; aluminum foil paper; damage; photoelectric switch; GDX2

Chinese classification number: TS43 Document identification code: B

一, Overview

Currently, the GDX2 cigarette packaging unit manufactured by Italian G.D Company can only detect offset and missing pieces of aluminum foil, and reject them at the No. 3 wheel station, but it cannot detect subsequent processes: Mainly It is the damaged and missing aluminum foil produced during the clamping and transfer process of the No. 3 wheel into the No. 4 wheel and the No. 4 wheel into the No. 5 wheel cigarette packs that are detected and eliminated. The missing aluminum foil paper will cause the cigarettes to be processed during the packaging forming and delivery process. The lack of wrapping and restraint in the vehicle resulted in missing cigarette packs.

According to statistics, from January to May 2011, the number of cigarette packs missing aluminum foil paper during product quality inspections was ***11. According to the "China Tobacco Anhui Cigarette Defect Classification Rules", missing or damaged aluminum foil and missing cigarette packs are Class A defects, which seriously affect product quality.

2. Analysis

From the equipment process flow chart, it can be seen that the detection of aluminum foil paper skew and lack of aluminum foil paper is located at position 10, and the detection of aluminum foil paper missing pull tab is located at position 13. From Positions 9 to 19 may cause the aluminum foil paper to be missing or damaged, and position 21 is the No. 5 wheel cigarette pack presence detection (2S519). The function is to detect the internal position of the cigarette pack, that is, after the trademark paper arrives, whether the aluminum foil cigarette pack is intact. Performed at 229° phase. If there is a lack of cigarette packs (empty label paper), then the machine will shut down, and the No. 12 LED indicator light on the circuit board N12 will light up, displaying the "No. 5 wheel lacks cigarette packs" signal. After the machine is started, the empty cigarette packets are removed at the R position of wheel No. 6 in the downstream process.

However, because the original GDX2 packaging machine’s No. 5 wheel lack of cigarette pack detection uses a capacitive proximity switch, the detection principle is: when an object moves towards the proximity switch, regardless of whether it is a conductor or not, as long as it is close to the range, This can cause the dielectric constant of the capacitor to change, causing the capacitance and the circuit state connected to the measuring head to also change, thereby controlling the switch to be turned on or off. Its working principle determines that the object detected by this proximity switch is not limited to conductors, but can also be insulators. Therefore, if the aluminum foil paper is partially damaged or missing in the subsequent process of wheel 3, but some cigarettes are still left in the box mold, and it happens to pass the detection end of the 2S519 proximity switch during operation, the cigarette pack will be considered intact and will continue The wrapped trademark paper is regarded as a qualified product and flows into the next process, causing market quality feedback and complaints.

3. Solutions

1 Re-select the proximity switch

According to the metallic properties of the aluminum foil coating attached to the surface of the aluminum foil paper of the cigarette pack, select an inductive proximity switch Replace the original capacitive proximity switch. The detection principle is: when a conductor is close to an electromagnetic field, eddy currents are generated inside it. This eddy current reacts to the proximity switch, causing the internal circuit parameters of the switch to change, thereby identifying whether a conductor is moving closer, and then controlling the on or off of the switch. The objects that this proximity switch can detect must be conductors. Therefore, it can be used to detect whether the aluminum foil paper is missing or damaged.

Install a proximity switch on the opposite side of the 2 cigarette packs

The original 2S519 cigarette pack presence detection point is installed on the outside of the fifth wheel. If it is only replaced with a photoelectric proximity switch, only It can detect the missing and damaged aluminum foil paper on the outside of the cigarette pack. However, if the aluminum foil paper on the inside of the cigarette pack is missing or damaged, it may not be detected due to the obstruction of the cigarette group in the cigarette pack, and unqualified cigarette packs may still be missed.

To this end, a photoelectric proximity switch of the same model is added opposite the original 2S519 position and fixed with a designed and processed arc bracket (installed on the wheel base) to avoid contact with the No. 5 wheel during rotation. Interference occurs.

Through the comparative analysis in Figure 3, before the equipment transformation, A and C are the detection areas for aluminum foil paper skew and lack of aluminum foil paper, A and B are the detection areas for aluminum foil paper missing pull tabs, and the large area D is the detection area for no aluminum foil paper. detection area. Through modification, the two inductive proximity switches connected in series have added the detection of E and F areas on the basis of the original aluminum foil defect detection, which effectively improves the detection range of aluminum foil defects and reduces the risk of missed detection of cigarette packs with aluminum foil defects. Probability.

3 Electrical transformation

Connect two proximity switches in series, connect them to the control circuit through the connector, and output them to 12 o'clock on the N12 board. Since only the sensor type, quantity and location have changed, and the original package missing detection and rejection control module remains unchanged, there is no need to make changes to the PLC program.

IV. Application effects

In June 2011, the workshop successively implemented modifications to eliminate cigarette packs with missing aluminum foil paper on 11 GDX2 units. Through nearly half a year of follow-up verification, it was found that the equipment is running stably and the transformation has not had an adverse impact on the performance of the original machine. At the same time, due to changes in the detection range and functions, the rejection rate due to missing and damaged aluminum foil has been significantly reduced. The market feedback caused by this quality defect in the first half of the year was only 1 box, a decrease of 90.9% from the first half of the year.

Conclusion

In summary, through the modification and design of the original quality inspection point on the fifth wheel of the GDX2 cigarette packaging machine, it has effectively reduced the flow of defective aluminum foil cigarette packs into the next process. The probability improves product quality. As the mainstream production equipment of the domestic tobacco industry, the GDX2 cigarette packaging machine has strong promotion value because of its simplicity and ease of use.

References

［1］Cheng Daxian. Mechanical Design Handbook［M］. Beijing: Chemical Industry Press (Fifth Edition), 2008.

[2] An Yuhong. "Application of Proximity Switch"[J]. Electrical Age, 2005 (07): 110-111.

[3] "YB45 (X2) Hard Box Packaging Machine Detection System". Shanghai Tobacco Machinery Co., Ltd.