A method and system for detecting and removing missing cigarette packs

Abstract

A method and system for detecting and removing missing cigarette packs in a carton. The system includes a missing pack detection device, a carton cigarette removing device, a PLC, and a display screen. By taking the difference in time obtained by the first optical fiber probe and four metal probes of the missing pack detection device and taking the absolute value, if all values are less than the allowable timing error, there is no missing pack. If any value is greater than the allowable timing error, it is considered that there is a missing small cigarette pack in the carton, and a signal of missing cigarette packs in the carton is sent to the PLC. When the PLC receives the missing pack signal, it sends it to the removing device to remove the cartons with missing packs through the reversing lug belt. If manual packaging is required, the smoke blocking cylinder of the removing device is lowered, and the lug belt rotates forward to push the qualified cartons of cigarettes out from the qualified product pushing path B, realizing product diversion, completely separating defective products and qualified products, and preventing defective cartons of cigarettes from flowing into the market.

Description

Technical Field

[0001] The present invention relates to the field of cigarette manufacturing, and particularly to a method and system for detecting and removing missing cigarette packs in a carton, and more particularly to a method and system for detecting and removing missing cigarette packs in a carton with a special missing pack mode. Background Art

[0002] At present, the main cigarette pack detectors used in each cigarette factory are photon missing pack detectors, weight missing pack detectors, negative pressure missing pack detectors, imaging missing pack detectors, etc. These devices can better solve the quality defect of missing packs that occur during the operation of the equipment. However, during the actual detection of missing cigarette packs in a carton, due to various external factors, there are defects in varying degrees and the problem of missing cigarette packs in a carton cannot be completely solved. As a result, missing-pack cartons of cigarettes flow into the next process and enter the market, which not only damages the interests of consumers but also damages the reputation and image of the enterprise.

[0003] The existing GDX2 unit in the factory has a set of cigarette missing pack removal device before the cartons of cigarettes are conveyed to the elevator as the final cigarette defect removal device. This device uses a cylinder to reciprocate to perform the removal action. This set of devices also has the following functions: it serves as a pushing device for switching the finished cigarette packs to the manual packing conveying channel when the conveyor belt stops or during the manual packing process. The following problems exist in the above technology: The removed cartons of cigarettes and the normal products pushed out during the conveyor belt stop or the manual packing process are located on the same conveying track. If the removed products are not cleaned up in time, when the equipment suddenly switches to work on the manual packing conveying channel, the defective products will be mixed with the normal products, and the defective products are mostly missing-pack defects. The appearance of the cartons is basically no different from that of the qualified products and cannot be picked out manually, posing a greater quality hazard. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method and system for detecting and removing missing cigarette packs in a carton. This device uses metal detection heads and fiber optic probes arranged in multiple directions to cooperate and compare the time difference when a carton of cigarettes (10) passes through the metal detection heads and fiber optic probes. If all the time difference values are less than the allowable timing error, it is considered that the carton of cigarettes (10) has no missing packs; if any value is greater than the allowable timing error, it is considered that there is a missing small pack in the carton of cigarettes (10), and the carton of cigarettes (10) judged to be a missing pack is continuously conveyed to the rear and the defective products are removed by reversing the lug belt. Those without missing packs are pushed out as qualified products to the manual packing channel or continuously conveyed to the rear elevator through the forward rotation of the lug belt. This device can not only detect the missing packs of the carton of cigarettes (10), but also, when it is necessary to switch to work on the manual packing conveying channel, correspond to the defective products and qualified products through two different rotations to divert the products and completely separate the defective products and qualified products.

[0005] The specific technical solutions are as follows:

[0006] A cigarette pack missing detection and rejection system, characterized in that the system comprises: a pack missing detection device (20), a cigarette pack (10) rejection device and a PLC;

[0007] The missing pack detection device (20) is composed of four symmetrically arranged metal probes (202) and a first optical fiber probe (201), wherein the two top probes are aimed at the small packs of cigarettes on the upper layer of the cigarette carton (10), and the two side probes are aimed at the small packs of cigarettes on the lower layer, and the optical fiber probe is located in the center of the line connecting the two top metal probes (202);

[0008] A cigarette strip (10) rejection device is installed downstream of a finished product output channel A on which a missing pack detection device (20) is installed, and is used to divide the cigarette strips (10) into three paths for transportation, comprising: a bracket (1), a rejection mechanism connected to the bracket (1), a photoelectric switch (8) for starting and stopping the rejection mechanism, and a second optical fiber probe (6) for detecting the cigarette strips (10);

[0009] The bracket (1) is arranged at the finished product output channel A and is erected above the channel, and a protective cover (5) for preventing the cigarette strips (10) from escaping is fixed thereon by bolts;

[0010] The rejection mechanism includes a lug belt and a smoke blocking cylinder (3); the lug belt is a synchronous toothed belt (2), and the toothed belt (2) is connected to two synchronous wheels and driven by a servo motor (7); the smoke blocking cylinder (3) is fixedly connected to the front end of the bracket (1) along the direction of the finished product output channel A, and the top end of the cylinder piston rod is connected to a smoke blocking block (4) for lowering the smoke blocking cylinder (3) to block the cigarette strips (10) from being transported to the elevator when the equipment switches to the manual packing conveyor belt D;

[0011] The photoelectric switch (8) is fixedly mounted on the bracket (1) above the lug belt and is used to trigger the photoelectric switch (8) when the lug belt completes the cigarette pushing and rejecting action and recovers, and sends a signal to the PLC, which controls the servo motor (7) to stop rotating;

[0012] The second optical fiber probe (6) is mounted on the front end of the bracket (1) and located on either side of the smoke blocking cylinder (3) for detecting whether a cigarette strip (10) exists below the cylinder;

[0013] The PLC is connected to the missing pack detection device (20) and the cigarette strip (10) rejection device by signal;

[0014] The display screen is fixedly installed next to the finished product output channel A and is used to display the real-time data of the equipment operation, or to modify the adjustable parameters.

[0015] Furthermore, the lug belt is a toothed belt (2) with lugs (21) connected to the outer surface, and the device comprises at least two parallel lug belts to ensure that the cigarette (10) is pushed out stably.

[0016] Further, the lug (21) includes one or two.

[0017] Further, when the lug belt rotates forward, the lug (21) pushes the qualified products onto the manual packing conveyor belt D; after receiving the defective product rejection signal, the PLC controls the servo motor (7) to rotate the lug belt in reverse, and the lug (21) rejects the defective products into the defective product cigarette receiving box (9).

[0018] Further, the two sides of the protective cover are respectively hinged with a first protective cover (51) and a second protective cover (52).

[0019] Further, the PLC outputs a signal to the solenoid valve to control the cylinder action, and outputs a control signal to the servo driver to control the start, stop, forward rotation and reverse rotation of the servo motor (7).

[0020] Further, the second optical fiber probe (6) includes at least two, and the two second optical fiber probes (6) are arranged vertically and the distance therebetween is greater than or equal to the width of the smoke blocking block (4).

[0021] Further, the path includes a qualified product pushing-out path B, a path for the finished product output channel A to be conveyed to the elevator, and an unqualified product rejection path C.

[0022] A method for rejecting defective cigarette packs includes:

[0023] S1, obtaining a cigarette pack defective signal through the defective pack detection device (20);

[0024] ① Take a comparison value t0. When the cigarette pack (10) is being conveyed and reaches below the optical fiber probe of the defective pack detection device (20), it triggers the optical fiber signal converter to send a timing start signal to the PLC to start timing. When the cigarette pack (10) leaves, the signal of the optical fiber signal converter flips and sends a timing stop signal to the PLC, and at this time the timing ends to obtain the time t0;

[0025] ② The small cigarette packs are wrapped with aluminum foil. When the cigarette packs pass through the metal probe (202), the probe outputs a high level to the PLC, and when leaving the probe side, the probe resumes low level output. The PLC times the duration of the high level to obtain the times of the four metal probes (202) as t1, t2, t3, and t4 respectively;

[0026] ③ Subtract t1, t2, t3, and t4 from t0 and take the absolute value. If all values are less than the allowable timing error, it is considered that the cigarette pack (10) has no defect; if any value is greater than the allowable timing error, it is considered that the small packs of the cigarette pack (10) are missing, and a cigarette pack (10) defective signal is sent to the PLC;

[0027] S2. Remove the cigarette packs with missing packets through a removal mechanism;

[0028] ① After the removal device receives the defective product removal signal, the PLC controls the servo motor (7) to rotate the lug belt in the reverse direction, and removes the defective products into the non-conforming product cigarette receiving box (9);

[0029] ② After completing the removal action, the lug belt returns to the fixed position. At this position, the lug belt just triggers the photoelectric switch (8) of the cigarette pack (10) removal device. The photoelectric switch (8) sends a signal to the PLC, and the PLC controls the servo motor (7) to stop rotating, completing one removal action.

[0030] Furthermore, the value of the allowable timing error in step (3) of S1 can be modified and set according to the actual situation.

[0031] Working principle of the present invention: First, regarding the detection of missing packets in the cigarette packs (10), when the cigarette packs (10) are being conveyed and reach below the fiber optic probe, it triggers the fiber optic signal converter and sends a timing start signal to the PLC. At this time, timing starts. When the cigarette packs (10) leave, the signal of the fiber optic signal converter flips and sends a timing stop signal to the PLC. At this time, the timing ends, and the time is t0; and because the small cigarette packets are wrapped with aluminum foil, when the cigarette packets pass below the metal probe (202), the probe outputs a high level to the metal probe (202), and when leaving below the probe, the probe resumes low-level output. The PLC times the duration of the high level. The durations of the high levels of each probe are t1, t2, t3, t4 respectively. These times are subtracted from t0 and the absolute values are taken. If all values are less than the allowable timing error (this value can be modified and set), it is considered that the cigarette packs (10) have no missing packets; if any value is greater than the allowable timing error, it is considered that there is a missing small packet in the cigarette packs (10). At this time, the PLC sends a removal signal to the removal device to remove the cigarette packs (10) with missing packets.

[0032] Working principle of the removal device: When using this device to switch the equipment to work on the manual packing conveyor belt D, the PLC receives the conveying switching signal, outputs a signal to the solenoid valve to control the cylinder to act. The smoke-blocking cylinder (3) drops, and the smoke-blocking block (4) extends downward to block the cigarette packs (10) from being conveyed along the finished product output channel A to the elevator on the finished product output channel A; and in order to prevent the cylinder from suddenly dropping when receiving the switching signal and clamping the cigarette packs (10) that are still moving below, two fiber optic probes are also installed to ensure that the smoke-blocking block (4) of the smoke-blocking cylinder (3) drops when there are no cigarette packs (10) below it; when the equipment is normally conveying products, the products are sent to the elevator along the conveyor belt of the finished product output channel A. At this time, the smoke-blocking cylinder (3) is in the lifted state.

[0033] The lug belt rotates forward, pushing the qualified products onto the manual packing conveyor belt D; in the normal product conveying and manual packing conveying states, after receiving the defective product rejection signal, the rejection device rotates the lug belt backward to reject the defective products into the defective product cigarette receiving box (9); after each cigarette pushing and rejection action, the lug belt returns to a fixed position, at which position the lug belt just touches the photoelectric switch (8), and this switch sends a signal to the PLC, which controls the servo motor (7) to stop rotating and rotate forward or backward.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] (1) Detect the lack of cigarette packets in the strip cigarettes in multiple directions, effectively avoiding the missed detection of special lack of cigarette packets caused by the turning of the small packets in the strip cigarette box.

[0036] (2) The lug belt is driven by a servo motor and can rotate forward and backward. The two different rotations respectively correspond to defective products and qualified products. After the defective products are rejected, they fall into the cigarette receiving box, while the qualified products are pushed onto the manual packing conveyor belt or sent to the elevator along the conveyor belt of the finished product output channel, completely separating the defective products and the qualified products.

[0037] (3) Adopting PLC control and servo motor drive, it can adapt to different products by changing the program, with high production flexibility. Description of the Drawings

[0038] Figure 1 is the lack of cigarette packet detection device of the present invention;

[0039] Figure 2 is the front view of the lack of cigarette packet detection device;

[0040] Figure 3 is the structural schematic diagram of the strip cigarette rejection device of the present invention;

[0041] Figure 4 is the front schematic diagram of the assembled structure of the strip cigarette rejection device of the present invention;

[0042] Figure 5 is the back schematic diagram of the assembled structure of the strip cigarette rejection device of the present invention;

[0043] Figure 6 is the closed state diagram of the protective cover of the strip cigarette rejection device of the present invention;

[0044] Figure 7 is the defective product rejection side schematic diagram of the strip cigarette rejection device of the present invention;

[0045] Figure 8 is the qualified product pushing path schematic diagram of the strip cigarette rejection device of the present invention;

[0046] Figure 9Front view of the cigarette rejecting device of the present invention;

[0047] Figure 10 Left view of the present invention;

[0048] Figure 11 Schematic diagram of the situation of missing cigarette packs;

[0049] In the figure, 1 - support; 2 - toothed belt; 21 - lug; 22 - driving wheel; 23 - driven wheel; 24 - bearing; 3 - smoke blocking cylinder; 4 - smoke blocking block; 5 - protective cover; 51 - first protective cover; 52 - second protective cover; 6 - second optical fiber probe; 7 - servo motor; 8 - photoelectric switch; 9 - cigarette receiving box; 10 - cigarette; 20 - missing pack detection device; 201 - first optical fiber probe; 202 - metal probe; 2021 - metal probe a; 2022 - metal probe b; 2023 - metal probe c; 2024 - metal probe d; A - finished product output channel; B - qualified product pushing path; C - unqualified product rejecting path; D - manual packing conveyor belt. Specific implementation manner

[0050] To make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in combination with specific implementation manners and referring to the attached drawings. It should be understood that these descriptions are only exemplary and do not intend to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0051] Embodiment 1: A method for rejecting missing-pack cigarettes 10, including:

[0052] S1, obtaining the missing-pack signal of the cigarette 10 through the missing-pack detection device 20;

[0053] ① Obtain a comparison value t0. When the cigarette 10 is being conveyed and reaches below the optical fiber probe of the missing-pack detection device 20, it triggers the optical fiber signal converter, sends a timing start signal to the PLC to start timing. When the cigarette 10 leaves, the signal of the optical fiber signal converter flips, sends a timing stop signal to the PLC, and at this time, the timing ends, obtaining the time t0;

[0054] ② The small cigarette pack is wrapped with aluminum foil paper. When the cigarette pack passes through the metal probe, the probe outputs a high level to the PLC, and when it leaves the probe, the probe resumes low-level output. The PLC times the duration of the high level, and obtains the times of the four metal probes, namely t1, t2, t3, and t4, for the four metal probes 202 (metal probe a 2021, metal probe b 2022, metal probe c 2023; metal probe d 2024);

[0055] ③Subtract t1, t2, t3, and t4 from t0, take the absolute value. If all values are less than the allowable timing error (this value can be modified and set), it is considered that there is no missing packet in the cigarette strip 10. If any value is greater than the allowable timing error, it is considered that there is a missing packet in the cigarette strip 10, and a signal indicating a missing packet in the cigarette strip 10 is sent to the PLC.

[0056] S2, and the defective cigarette strip 10 is removed through the removal mechanism.

[0057] ①After receiving the defective product removal signal, the PLC controls the servo motor 7 to rotate the lug belt in the reverse direction, and removes the defective product into the defective product cigarette receiving box 9.

[0058] ②After completing the removal action, the lug belt returns to the fixed position. At this position, the lug belt just triggers the photoelectric switch 8 of the cigarette strip 10 removal device. The photoelectric switch 8 sends the signal to the PLC, and the PLC controls the servo motor 7 to stop rotating, completing one removal action.

[0059] The missing packet situation includes the two situations of p and m as shown Figure 9 The ordinary missing packet as shown by p and the special missing packet situation as shown by m. The normal non-missing cigarette strip is like Figure 9 n shown.

[0060] Embodiment 2: A cigarette strip 10 missing packet detection and removal system, which includes: a missing packet detection device 20, a cigarette strip 10 removal device, a PLC, and a display screen; the missing packet detection device 20 is composed of 4 symmetrically arranged metal probes and a first optical fiber probe. The two probes at the top are aligned with the small packets of cigarettes on the upper layer of the cigarette strip 10, and the two probes on the side are aligned with the small packets of cigarettes on the bottom layer. The optical fiber probe is located at the center of the connection line of the two top metal probes.

[0061] The cigarette strip 10 removal device is installed downstream of the finished product output channel A where the missing packet detection device 20 is installed, and is used to transport the cigarette strip 10 in three paths, including: a bracket 11, a removal mechanism connected to the bracket 11, a photoelectric switch 8 for starting and stopping the removal mechanism, and a second optical fiber probe 6 for detecting the passing of the cigarette strip 10.

[0062] The PLC is signal-connected to the missing packet detection device 20 and the cigarette strip 10 removal device.

[0063] The display screen is fixedly installed beside the finished product output channel A for displaying the real-time data of the equipment operation, or the adjustable parameters can be modified through it.

[0064] Embodiment 3: A multifunctional cigarette strip 10 rejection device, which is installed above the finished product output channel A and is used to convey the cigarette strips 10 in three paths. The paths include a qualified product pushing path B, a path from the finished product output channel A to the elevator, and a defective product rejection path C. The device includes a bracket 11, a rejection device, a photoelectric switch 8, a detection device, a PLC, and a cigarette receiving box 9.

[0065] The bracket 11 is arranged at the finished product output channel A and is installed above the channel. A protective cover 5 for preventing the cigarette strips 10 from jumping out is hinged on it. The protective cover 5 includes a first protective cover 51 installed above the qualified product pushing path B and a second protective cover 52 installed above the defective product rejection path C. The protective cover 5 can prevent the pushed cigarette strips 10 from jumping and deviating from the path.

[0066] The rejection device includes a lug belt and a smoke blocking cylinder 3. The lug belt is a synchronous toothed belt 2, and lugs 21 are connected to the outer surface of the toothed belt 2. The toothed belt 2 is connected to two synchronous wheels and is driven by a servo motor 7. The synchronous wheels are toothed wheels, including a driving wheel 22 and a driven wheel 23. The driving wheel 22 and the driven wheel 23 are connected to the bracket 11 through bearings 24, and one end of the bearing 24 of the driving wheel 22 is connected to the servo motor 7. When the lug belt rotates forward, the lugs 21 push the qualified products through the qualified product pushing path B onto the manual packing conveyor belt D. After receiving the defective product rejection signal, the PLC controls the servo motor 7 to rotate the lug belt in reverse, and the lugs 21 reject the defective products and push them into the defective product receiving box 9 from the defective product rejection path C. The smoke blocking cylinder 3 is fixedly connected to the front end of the bracket 11 along the direction of the finished product output channel A, and the top of the cylinder piston rod is connected with a smoke blocking block 4 for blocking the conveyance of the cigarette strips 10 to the elevator when the device switches to the manual packing conveyor belt D for operation.

[0067] The photoelectric switch 8 is fixedly installed on the bracket 11 above the lug belt. When the lug belt is at the pause position, the lug 21 is directly below the photoelectric switch 8 to trigger the photoelectric switch 8. It is used to trigger the photoelectric switch 8 after the lug belt completes the cigarette pushing and rejection actions and resumes, and sends the signal to the PLC, and the PLC controls the servo motor 7 to stop rotating.

[0068] The detection device is two vertically arranged optical fiber probes installed at the front end of the bracket 11 on one side of the smoke blocking cylinder 3. The distance between the two optical fiber probes is equal to the width of the smoke blocking block 4, ensuring that the smoke blocking cylinder 3 is lowered when there is no cigarette below it, and preventing the cylinder from suddenly lowering and clamping the still moving cigarette strips 10 below when receiving the switching signal.

[0069] The cigarette receiving box 9 is located below the defective product rejection path C and is used to receive the rejected defective cigarette strips 10. Its opposite side is the qualified product pushing path B and is connected to the manual packing conveyor belt D.

[0070] The PLC is electrically connected to the servo motor 7 and the cylinder for controlling the rotation and stop of the servo motor 7 and the expansion and contraction of the cylinder. The PLC outputs a signal to the solenoid valve to control the action of the cylinder, and the PLC outputs a control signal to the servo driver to control the start, stop, forward rotation and reverse rotation of the servo motor 7.

[0071] It should be understood that the above specific embodiments of the present invention are only used for exemplifying the invention or explaining the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A cigarette pack missing detection and rejection system, characterized in that: The system comprises: a pack-missing detection device (20), a cigarette strip rejection device, a PLC and a display screen; The missing pack detection device (20) is composed of four symmetrically arranged metal probes (202) and a first optical fiber probe (201), wherein the two top probes are aimed at the small packs of cigarettes on the upper layer of the cigarette carton (10), and the two side probes are aimed at the small packs of cigarettes on the lower layer, and the optical fiber probe is located in the center of the line connecting the two top metal probes (202); A cigarette strip (10) rejection device is installed downstream of a finished product output channel A on which a missing pack detection device (20) is installed, and is used to divide the cigarette strips (10) into three paths for transportation, comprising: a bracket (1), a rejection mechanism connected to the bracket (1), a photoelectric switch (8) for starting and stopping the rejection mechanism, and a second optical fiber probe (6) for detecting the cigarette strips (10); The bracket (1) is arranged at the finished product output channel A and is erected above the channel, and a protective cover (5) for preventing the cigarette strips (10) from escaping is fixed thereon by bolts; The rejection mechanism includes a lug belt and a smoke blocking cylinder (3); the lug belt is a synchronous toothed belt (2), the toothed belt (2) is connected to two synchronous wheels and driven by a servo motor (7), and the lug belt rotates in the forward direction so that the lug (21) pushes the qualified products onto the manual packing conveyor belt D; after receiving the defective product rejection signal, the rejection device controls the servo motor (7) to rotate the lug belt in the reverse direction, and the lug (21) rejects the defective products into the unqualified product receiving box (9); the smoke blocking cylinder (3) is fixedly connected to the front end of the bracket (1) along the direction of the finished product output channel A, and the top end of the cylinder piston rod is connected to a smoke blocking block (4) for lowering the smoke blocking cylinder (3) when the equipment switches to the manual packing conveyor belt D to prevent the cigarette strips (10) from being transported to the elevator; The photoelectric switch (8) is fixedly mounted on the bracket (1) above the lug belt and is used to trigger the photoelectric switch (8) when the lug belt completes the cigarette pushing and rejecting action and recovers, and sends a signal to the PLC, which controls the servo motor (7) to stop rotating; The second optical fiber probe (6) is mounted on the front end of the bracket (1) on either side of the smoke blocking cylinder (3) for detecting whether a cigarette strip (10) exists below the cylinder; The PLC is connected to the missing pack detection device (20) and the cigarette strip (10) rejection device by signal; The display screen is fixedly installed next to the finished product output channel A and is used to display the real-time data of the equipment operation, or to modify the adjustable parameters.

2. The cigarette pack missing detection and rejection system according to claim 1, characterized in that: The lug belt is a toothed belt (2) with lugs (21) connected to the outer surface, and the device comprises at least two parallel lug belts to ensure stable pushing out of the cigarette (10).

3. The cigarette pack missing detection and rejection system according to claim 2, characterized in that: The lug (21) includes one or two.

4. The cigarette pack missing detection and rejection system according to claim 1, characterized in that: A first protective cover (51) and a second protective cover (52) are hingedly connected to both sides of the protective cover (5).

5. The cigarette pack missing detection and rejection system according to claim 1, characterized in that: The PLC outputs a signal to the electromagnetic valve to control the cylinder action, and the PLC outputs a control signal to the servo driver to control the start and stop, forward and reverse rotation of the servo motor (7).

6. The cigarette pack missing detection and rejection system according to claim 1, characterized in that: The second optical fiber probes (6) include at least two, and the two second optical fiber probes (6) are arranged in a vertical row with a spacing greater than or equal to the width of the smoke barrier block (4).

7. The cigarette pack missing detection and rejection system according to claim 1, characterized in that: The path includes a qualified product ejection path B, a finished product output channel A for transporting to an elevator path, and a failed product rejection path C.

8. A method for rejecting missing packs of cigarette cartons according to the system for detecting and rejecting missing packs of cigarette cartons according to any one of claims 1 to 7, characterized in that: include: S1, obtaining a cigarette pack shortage signal (10) through a pack shortage detection device (20); (1) Taking the comparison value t0, when the cigarette (10) is being transported, it reaches the bottom of the optical fiber probe of the missing pack detection device (20), triggering the optical fiber signal converter, and sending a timing start signal to the PLC to start timing. When the cigarette (10) leaves, the signal of the optical fiber signal converter is reversed, and a timing stop signal is sent to the PLC, at which point the timing ends, and the time t0 is obtained; (2) A small cigarette pack is wrapped with aluminum foil. When the cigarette pack passes through the metal probe (202), the probe outputs a high level to the PLC. When the cigarette pack leaves the probe, the probe returns to a low level output. The PLC times the duration of the high level and obtains the times of the four metal probes (202) as t1, t2, t3, and t4 respectively; (3) Subtract t1, t2, t3, t4 from t0 and take the absolute value. If all the values are less than the allowable timing error, it is considered that there is no missing pack of cigarettes (10); if any value is greater than the allowable timing error, it is considered that there is a missing pack of cigarettes (10), and a missing pack signal of cigarettes (10) is sent to the PLC; S2, removing missing packs of cigarettes (10) through a removal mechanism; (1) After receiving the defective product rejection signal, the rejection device controls the servo motor (7) to rotate the lug belt in the reverse direction to reject the defective product into the unqualified product receiving box (9); (2) After the rejection action is completed, the lug belt returns to the fixed position. At this position, the lug belt just triggers the photoelectric switch (8) of the cigarette (10) rejection device. The photoelectric switch (8) sends a signal to the PLC, and the PLC controls the servo motor (7) to stop rotating, completing a rejection action.

9. The method for rejecting missing packs of cigarettes according to claim 8, characterized in that: The value of the allowable timing error in step (3) of S1 can be modified and set according to actual conditions.

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