Full-filling detection device for packaging carton
By designing an electric roller conveyor line and a coordinated circuit, the problem of inaccurate weighing of packaging cartons was solved, enabling accurate weighing and automatic handling of defective products, thereby improving inspection efficiency and product quality.
Patent Information
- Application Number
- CN202423232001.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2034-12-26
AI Technical Summary
Existing packaging carton weight detection equipment suffers from inaccurate weighing due to structural limitations during the weighing process, and cannot effectively handle defective products, thus affecting product quality.
Design a full-load detection device for packaging cartons. Through the coordinated action of an electric roller conveyor line, photoelectric switch, cylinder, trigger circuit, weighing control circuit and timing circuit, ensure the spacing between the conveyor rollers on the front and back sides of the weighing station to achieve accurate weighing, and automatically eject unqualified products when they are not qualified.
It improves the accuracy of weighing packaging cartons, ensuring that qualified products enter the next workstation, automatically handles unqualified products, and improves inspection efficiency and product quality.
Smart Images
Figure CN223870166U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of testing equipment technology, and in particular to a full-fill detection device for packaging cartons. Background Technology
[0002] In assembly line production, it is necessary to weigh each carton to ensure the quality of packaged goods such as cardboard boxes. Currently, this is usually done manually, which is inconvenient for workers and hinders work efficiency.
[0003] With advancements in industrial technology, equipment has emerged for the continuous weighing of packaging boxes conveyed by electric conveyor lines. Specifically, after a packaging box is transported to the weighing station by the electric conveyor, the motor temporarily stops, and the weighing mechanism weighs the box. If the weight of the box is below standard, an alarm is triggered to alert the operator, or the box is removed from the conveyor. While this method fulfills the weighing requirement to some extent, it also suffers from the following technical drawbacks due to structural limitations. Specifically, when the packaging carton arrives at the weighing station, the weighing station does not actually have a driving force. In order to ensure that the packaging carton can be output backward via the conveyor roller of the electric conveyor line after weighing, the lower part of the packaging carton is actually in contact with the upper part of the power conveyor roller or conveyor belt of the electric conveyor line at the rear of the weighing station (after weighing, the packaging carton can be output backward under the action of the conveyor roller or conveyor belt). In this way, the weight of the packaging carton will not be fully applied to the weighing station, which will more or less have an adverse effect on the accurate weighing of the packaging carton (that is to say, there is a possibility that packaging cartons that are underweight may be directly conveyed to the next station, and underweight goods may be sold directly, which will have an adverse effect on the sales of goods). Utility Model Content
[0004] To overcome the shortcomings of existing packaging carton weight detection equipment, which are limited by structure and have the drawbacks described in the background art, this utility model provides a packaging carton full-load detection device. Under the joint action of related mechanisms, after the packaging carton arrives at the weighing station, the distance between the packaging carton and the conveyor rollers on the front and rear sides of the weighing station is maintained to ensure the accuracy of weighing as much as possible. After weighing, the related mechanisms can make the rear of the carton contact the conveyor rollers on the rear side of the weighing station and transport it to the next station. Furthermore, if the weight of the goods inside the carton is not up to standard, it can be automatically pushed out to the non-conforming product station, thus ensuring that the weight of the packaged goods is up to standard.
[0005] The technical solution adopted by this utility model to solve its technical problem is:
[0006] A full-load detection device for packaging cartons includes an electric roller conveyor line, a photoelectric switch, an air compressor, and a cylinder. It also includes a trigger circuit, a weighing control circuit, a timing circuit, and a weighing mechanism. The electric roller conveyor line has at least two sets. One set has openings in the middle of the front and rear sides of its side panels. One set is installed laterally at the work station, and the other set is installed longitudinally at the work station, with the rear end of its conveyor roller located at the front opening of the first set. The first set has an installation port. The weighing mechanism includes a pressure sensor, an electric push rod, a fixed plate, a weighing plate, linear bearings, and a housing. A support column is installed at one lower end of the housing. The lower end of the electric push rod is hinged to the other lower end of the housing, and the upper end of the electric push rod is hinged to one side of the lower end of the fixed plate. The other side of the lower end of the fixed plate is hinged to the upper end of the support column. Multiple sets of linear bearings are installed at their lower ends on the fixed plate. The pressure sensor is mounted on the upper part of the fixed plate, and the lower end of the weighing plate is mounted on the upper end of the bearing rods of multiple linear bearings. The outer casing is mounted on the lower side of the mounting opening. A support frame is installed at the rear opening of one of the electric roller conveyors, and a cylinder is mounted on the upper end of the support frame. A push plate is installed at the front end of the piston rod of the cylinder. The photoelectric switch is installed on one side of one of the openings. The trigger circuit, weighing control circuit, and time control circuit are installed in the electrical control box. The power output terminal of the weighing control circuit and the power input terminal of the time control circuit are electrically connected. The signal output terminal of the photoelectric switch is connected to the signal input terminal of the trigger circuit. The power output terminal of the trigger circuit is electrically connected to the power input terminal of the motor of one of the electric roller conveyors. The control terminal of the trigger circuit is electrically connected to the power input terminals of the weighing control circuit and the pressure sensor. The signal output terminal of the pressure sensor is electrically connected to the signal input terminal of the weighing control circuit. The power output terminal of the time control circuit is electrically connected to the power input terminals of the electric push rod.
[0007] Furthermore, the upper height of the weighing plate is higher than the upper height of the outer shell, and the inner diameter of the outer shell is greater than the outer diameter of the weighing plate. The height of the weighing plate is lower than the upper height of the conveying roller of one of the electric drum conveyor lines.
[0008] Furthermore, the outer diameter of the push plate is smaller than the inner diameter of the opening.
[0009] Furthermore, the trigger circuit includes a time relay module and a relay that are electrically connected. The negative power input terminal and negative trigger signal input terminal of the time relay module are connected to the negative power input terminal of the relay, and the power output terminal of the time relay module is connected to the positive power input terminal of the relay.
[0010] Furthermore, the weighing control circuit includes an adjustable resistor, a resistor, a transistor, and a relay that are electrically connected. One end of the adjustable resistor is connected to one end of the first resistor and one end of the second resistor. The other end of the second resistor is connected to the base of the transistor. The collector of the transistor is connected to the negative power input terminal of the relay. The positive power input terminal of the relay is connected to the control power input terminal. The other end of the first resistor is connected to the emitter of the transistor.
[0011] Furthermore, the time control circuit includes four sets of time control switches that are electrically connected, wherein the power input terminals of two sets of time control switches are connected respectively, and the power input terminals of the other two sets of time control switches are connected respectively.
[0012] Compared with existing technologies, the advantages of this invention are as follows: With the combined action of relevant mechanisms, after the packaging carton reaches the weighing station and is detected by the photoelectric switch, the carton maintains a safe distance from the conveyor rollers on the front and rear sides of the weighing station. This ensures the accuracy of the weighing mechanism's measurement of the carton. After weighing, the rear side of the carton contacts the conveyor roller on the rear side of the weighing station and is conveyed to the next station. If the weight of the goods inside the carton is unqualified, the weighing control circuit and the timing circuit work together to automatically push the unqualified goods onto the conveyor rollers of another electric conveyor line and output them to the unqualified product station. This ensures that the weight of the packaged goods is qualified. In summary, this invention has good application prospects. Attached Figure Description
[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0015] Figure 2 This is a partial structural schematic diagram of the present invention;
[0016] Figure 3 This is the circuit diagram of this utility model. Detailed Implementation
[0017] Figures 1-3As shown, a full-load detection device for packaging cartons includes electric roller conveyor lines 101 and 102, a power module A1, a photoelectric switch A2, an air compressor (not shown), and a cylinder 2. It also includes a trigger circuit 3, a weighing control circuit 4, a timing circuit 5, and a weighing mechanism. There are two sets of electric roller conveyor lines. One set of electric roller conveyor lines 101 has an opening 104 on the front and rear sides of its guardrail 103. One set of electric roller conveyor lines 101 is installed laterally at the work station, while the other set of electric roller conveyor lines 102 is installed longitudinally at the work station, with the rear end of its conveyor rollers located within the first set of electric roller conveyor lines. Approximately 1 cm before the opening at the front end of line 101, the height of the conveyor roller of another set of electric roller conveyor lines 102 is lower than the height of the opening; one set of electric roller conveyor lines 101 has an open structure in the middle without a conveyor roller installed, serving as the installation port 105. The weighing mechanism includes a pressure sensor A4, an electric push rod M1, a fixing plate 61, a weighing plate 62, a linear bearing 63, and an outer shell 64 with an open upper end. A support column 65 is welded to the front and rear sides of the lower right end of the outer shell 64. There are at least two sets of electric push rods M1, with the lower ends of the cylinders of the two sets of electric push rods M1 respectively hinged to the front and rear parts of the left side of the outer shell 64. The upper ends of the movable columns 1 are hinged to the front and rear sides of the lower left end of the fixed plate 61, and the front and rear parts of the lower right end of the fixed plate 61 are hinged to the upper ends of the two support columns 65. There are four sets of linear bearings 63, and the lower ends of the bearing sleeves of the four sets of linear bearings 63 are fixedly installed around the upper end of the fixed plate 61. The lower end of the pressure sensor A4 is fixedly installed in the middle of the upper end of the fixed plate 61. The lower end of the weighing plate 62 is fixedly installed around the upper ends of the bearing rods of the four sets of linear bearings 63 (which guide the downward movement of the weighing plate 62), and the middle of the lower end of the weighing plate 62 is in contact with the upper end of the weighing surface of the pressure sensor A4. The front and rear ends of the outer side of the outer casing 64 are fixedly installed on one of the electric... The roller conveyor is mounted on the frame on the front and rear sides of the mounting port 105; a triangular support frame 106 is fixedly installed on the frame at the rear opening of one of the electric roller conveyors. The cylinder body of cylinder 2 is fixedly installed on the upper end of the support frame 106 in a longitudinal distribution. A push plate 21 is welded to the front end of the piston rod of cylinder 2. The photoelectric switch A2 is fixedly installed in the opening of the panel on the right side of the rear opening. The exhaust pipe of the air compressor's air tank and the intake pipe of the intake and exhaust solenoid valves at the front and rear ends of the cylinder body of cylinder 2 are connected by pipes. The power module A1, the trigger circuit 3, the weighing control circuit 4, and the time control circuit 5 are installed in the electrical control box 107 of one of the electric roller conveyors.
[0018] Figures 1-3As shown, the upper end of the weighing plate 62 is higher than the upper end of the outer casing 64, and the inner diameter of the outer casing 64 is larger than the outer diameter of the weighing plate 62. The height of the weighing plate 62 is 2 mm lower than the upper end of the conveyor roller 108 of one of the electric drum conveyor lines. The outer diameter of the push plate 21 is smaller than the inner diameter of the rear opening 104, and the probe of the photoelectric switch A2 faces the front end. The trigger circuit includes a time relay module A3 and a relay K1 connected by circuit board wiring. The negative power input terminal 2 and the negative trigger signal input terminal 4 of the time relay module A3 are connected to the negative power input terminal of the relay K1, and the power output terminal 5 of the time relay module A3 is connected to the positive power input terminal of the relay K1. The weighing control circuit includes an adjustable resistor RP1, resistors R1 and R2, a transistor T1, and a relay K2 connected via circuit board wiring. One end of the adjustable resistor RP1 is connected to one end of the first resistor R1 and one end of the second resistor R2. The other end of the second resistor R2 is connected to the base of the transistor T1. The collector of the transistor T1 is connected to the negative power input terminal of the relay K2. The positive power input terminal of the relay K2 is connected to the control power input terminal. The other end of the first resistor R1 is connected to the emitter of the transistor T1. The timing circuit includes four sets of timing switches A5, A6, A7, and A8 connected via circuit board wiring. The power input terminals 1 and 2 of two sets of timing switches A5 and A6 are connected respectively, and the power input terminals 1 and 2 of the other two sets of timing switches A7 and A8 are connected respectively.
[0019] Figures 1-3As shown, the power input terminals 1 and 2 of power module A1, the two control power input terminals of relay K1 in the trigger circuit, and the two poles of the 220V AC power supply are connected by wires. The power output terminals 3 and 4 of power module A1, the terminals 1 and 2 of time relay module A3, and the power input terminals 1 and 2 of photoelectric switch A2 are connected by wires. The normally closed contact of the power output terminal of relay K2 in the weighing control circuit, the emitter of transistor T1, and the terminals 1 and 2 of time control switch A5 in the time control circuit are connected by wires. The signal output terminal 3 of photoelectric switch A2 and the positive trigger signal input terminal 3 of time relay module A3 in the trigger circuit are connected by wires. The two normally closed contacts of relay K1 in the trigger circuit are connected to the power input terminal of motor M of one of the electric roller conveyor lines via wires. Pins 3 and 4 of time relay module A4 are connected to the signal input terminal of relay K2 in the weighing control circuit, the emitter of transistor T1, pins 1 and 2 of the pressure sensor A4, and pins 1 and 2 of the time control switches A7 and A8 via wires. Pin 3 of pressure sensor A4 is connected to the other end of adjustable resistor RP1 via wires. Pins 3 and 4 of the power output terminals of time control switches A5 and A6 are connected to the power input terminals of intake and exhaust solenoid valves DC1 and DC2 at the front and rear ends of the cylinder body via wires. Pins 3 and 4 of the power output terminals of time control switches A7 and A8 are connected to the positive and negative, and negative-positive power input terminals of electric push rod M via wires. Figure 3As shown, power module A1 is a finished product of AC 220V to DC 24V power module; time controllers A5, A6, A7, and A8 are finished products of time control switches of model KG316T, which have two power input terminals, two power output terminals, and seven setting buttons. Technicians can operate the seven buttons to set the output time of the two power output terminals; electric push rod M1 is a finished product of reciprocating electric telescopic rod with a power of 25W; relays K1 and K2 are model DC12V; time relay module A3 is a finished product of adjustable time relay module of model YYS-12V, which has two power input terminals, two power output terminals (one normally open and one normally closed power output terminal, the normally closed contact terminal of this new type is floating), four setting buttons, and two trigger signal input terminals. Technicians can operate the four buttons to set the output time of the normally open power output terminal after each input trigger signal. The pressure sensor A4 is a finished weighing sensor of model ZNLBM-IIX, which has two power input terminals and one signal output terminal; the transistor T1 is model 9013 (NPN); the photoelectric switch A2 is model E3F, which has two power input terminals and one signal output terminal. When there is an obstacle in front of the probe, the signal output terminal outputs power, and vice versa. The detection distance is 10 cm; the resistance values of resistors R1 and R2 are 10K and 47K respectively; the resistance value of adjustable resistor RP1 is 470K (the handle is located on the outside of the control box. The larger the resistance value is adjusted, the more likely the relay K2 will be energized when the weight of the packaging carton is relatively heavy, which means the weight threshold is set relatively high. The smaller the resistance value is adjusted, the more likely the relay K2 will be energized when the weight of the packaging carton is relatively light, which means the weight threshold is set relatively low. In this embodiment, it is adjusted to 38.2K).
[0020] Figures 1-3As shown, after the main power switch is turned on, power module A1 is powered on, and its pins 3 and 4 output 12V DC power to the power input terminals of photoelectric switch A2 and trigger circuit. Simultaneously, 220V power is supplied to the power input terminal of motor M of electric conveyor line 101 via the two control power input terminals and normally closed contact terminal of relay K1. Electric conveyor line 101 is powered on, and its conveyor roller 108 rotates clockwise, transporting the packaging cartons on the roller from left to right to the next station (the roller 108 of electric conveyor line 102 rotates counterclockwise, transporting subsequent items on the roller from back to front to the non-conforming product station). When the packaging cartons on the left side of electric conveyor line 101 (multiple cartons input from front to back) have not been transported to the detector of photoelectric switch A2, pin 3 of photoelectric switch A2 does not output a high level, and relay K1 remains de-energized and closed, with its control power input terminal and normally closed contact terminal closed. Thus, the conveyor roller 108 of electric conveyor line 101 continues to drive the cartons to the right end for output. When a carton is conveyed on the left side of the electric conveyor line 101 to the detector head of the photoelectric switch A2 (at this time, the conveyor roller rotating on the left end of the photoelectric switch A2 pushes the carton to move completely on the weighing plate 62, and the lower part of the left and right sides of the carton is separated from the lower part of the conveyor roller 108 on the left and right sides of the opening), the 3rd pin of the photoelectric switch A2 outputs a high level to the 3rd pin of the time relay module A3. Then, the 5th pin of the time relay module A3 outputs a high level for 5 seconds to the positive power input terminal of the relay K1, the weighing control circuit and the power input terminals of the pressure sensor A4, and the time control switches A7 and A8. After the relay K1 is energized and closed, its control power input terminal and normally closed contact terminal open. In this way, the motor M of the electric conveyor line 101 is temporarily de-energized, and the carton adjacent to the left end of the carton on the weighing plate 62 stops moving. After the pressure sensor RP1 and the weighing control circuit are powered on, the weight of the packaging carton will act on the force-bearing surface of the pressure sensor A4 through the weighing plate. The greater the weight of the packaging carton, the higher the voltage signal output by pin 3 of the pressure sensor A4, and vice versa. When the weight of the packaging carton and its contents is sufficient, the voltage signal output from pin 3 of pressure sensor A4 is divided by adjustable resistors RP1 and R1, and then reduced by resistor R2 to limit the current. This voltage is higher than 0.7V at the base of transistor T1, causing transistor T1 to conduct and output a high-level signal to the negative power input terminal of relay K2. Relay K2 is energized and its control power input terminal and normally closed contact terminal are open. Therefore, time switches A5 and A6 will not be energized and will not operate. When the weight of the packaging carton and its contents is insufficient (less than the weight set by adjustable resistor RP1), the voltage signal output from pin 3 of pressure sensor A4 is divided by adjustable resistors RP1 and R1, and then reduced by resistor R2 to limit the current. This voltage is lower than 0.7V at the base of transistor T1, causing transistor T1 to cut off and its collector no longer outputs a high-level signal to the negative power input terminal of relay K2. Relay K2 is de-energized and its control power input terminal and normally closed contact terminal are closed. Therefore, time switches A5 and A6 will be energized and will operate.After timer switch A5 is energized, its pins 3 and 4 will output power for 1 second to the power input terminal of the intake and exhaust solenoid valve DC2 at the rear of the cylinder. High-pressure air output from the air compressor's air tank enters the rear of the cylinder body (air at the front of the cylinder body is discharged through the exhaust port of the intake and exhaust solenoid valve DC1). The piston in the cylinder body quickly pushes the packaging carton forward via push plate 21, pushing the packaging carton onto the conveyor roller of another set of electric conveyor lines 102. The other set of electric conveyor lines 102 outputs it to the non-conforming product station. After timer switch A6 is energized, its pins 3 and 4 will output power for 1 second. The foot will output power for 1 second to the power input terminal of the intake and exhaust solenoid valve DC1 at the front of the cylinder. The high-pressure air output from the air compressor's air tank enters the front of the cylinder body (the air at the rear of the cylinder body is discharged through the exhaust port of the intake and exhaust solenoid valve DC2). The piston of the cylinder body drives the push plate 21 to quickly return to the initial position, preparing for the next push of the defective packaging carton. After the time control switch A7 is energized, its pins 3 and 4 will output power for 1 second at 3-second intervals to the positive and negative power input terminals of the two sets of electric push rods M1. The movable columns of the two sets of electric push rods M1 push the fixed plate. The weighing plate moves upwards from left to right along the support base 65. This causes the weighed and qualified packaging carton to slide to the right, its right end contacting the left end of the right-side conveyor roller 108. Due to the rotation of the conveyor roller 108, the weighed and qualified packaging carton automatically moves onto the right-side conveyor roller and proceeds to the next workstation. When the timer switch A8 is energized, its pins 3 and 4 output power for 1 second every 4 seconds to the negative and positive power input terminals of the two sets of electric push rods M1. The movable columns of the two sets of electric push rods M1 drive the fixed plate and the weighing plate upwards from right to left along the support base 65. The weighing plate moves until it reaches a horizontal position, preparing it for the next packaged carton to be weighed. After a 5-second power output from pin 5 of the time relay module A3, the power output stops. This de-energizes relay K1, the weighing control circuit, pressure sensor A4, and time switches A7 and A8, returning all circuits to their initial state, consistent with the previous process. One of the electric conveyor lines then transports the next packaged carton to the weighing plate 62 for weighing, achieving automated weight detection of packaged cartons and ensuring the packaged goods meet weight standards.
[0021] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model.
[0022] Furthermore, it should be understood that although this specification describes the embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A full-fill detection device for packaging cartons, comprising an electric roller conveyor line, a photoelectric switch, an air compressor, and a cylinder, characterized in that, It also includes a trigger circuit, a weighing control circuit, a timing circuit, and a weighing mechanism; there are at least two sets of electric roller conveyor lines, one of which has openings in the middle of the front and rear sides of the guardrail, one set of electric roller conveyor lines is installed laterally at the work station, and the other set of electric roller conveyor lines is installed longitudinally at the work station, with the rear end of the conveyor rollers of the other set located at the front opening of the first set of electric roller conveyor lines; one set of electric roller conveyor lines has an installation port, and the weighing mechanism includes a pressure sensor, an electric push rod, a fixed plate, a weighing plate, linear bearings, and a housing. A support column is installed at one end of the lower part of the housing, the lower end of the electric push rod is hinged to the other end of the lower part of the housing, the upper end of the electric push rod is hinged to one side of the lower end of the fixed plate, and the other side of the lower end of the fixed plate is hinged to the upper end of the support column. There are multiple sets of linear bearings, the lower ends of which are installed around the upper part of the fixed plate, and the lower end of the pressure sensor is installed on the fixed plate. The upper part of the fixed plate and the lower part of the weighing plate are respectively installed on the upper end of the bearing rods of multiple linear bearings, and the outer shell is installed on the lower side of the mounting port; a support frame is installed at the rear opening of one of the electric roller conveyors, and a cylinder is installed on the upper end of the support frame, with a push plate installed at the front end of the piston rod of the cylinder; the photoelectric switch is installed on one side of one of the openings, and the trigger circuit, weighing control circuit, and time control circuit are installed in the electrical control box; the power output terminal of the weighing control circuit and the power input terminal of the time control circuit are electrically connected, the signal output terminal of the photoelectric switch is connected to the signal input terminal of the trigger circuit, and the power output terminal of the trigger circuit is electrically connected to the power input terminal of the motor of one of the electric roller conveyors; the control terminal of the trigger circuit is electrically connected to the power input terminals of the weighing control circuit and the pressure sensor, and the signal output terminal of the pressure sensor is electrically connected to the signal input terminal of the weighing control circuit; the power output terminal of the time control circuit and the power input terminals of the electric push rod are electrically connected.
2. The full-fill detection device for packaging cartons according to claim 1, characterized in that, The upper height of the weighing plate is higher than the upper height of the outer shell, and the inner diameter of the outer shell is greater than the outer diameter of the weighing plate. The height of the weighing plate is lower than the upper height of the conveyor roller of one of the electric roller conveyor lines.
3. The full-fill detection device for packaging cartons according to claim 1, characterized in that, The outer diameter of the push plate is smaller than the inner diameter of the opening.
4. The full-fill detection device for packaging cartons according to claim 1, characterized in that, The trigger circuit includes a time relay module and a relay that are electrically connected. The negative power input terminal and negative trigger signal input terminal of the time relay module are connected to the negative power input terminal of the relay, and the power output terminal of the time relay module is connected to the positive power input terminal of the relay.
5. The full-fill detection device for packaging cartons according to claim 1, characterized in that, The weighing control circuit includes an adjustable resistor, a resistor, a transistor, and a relay that are electrically connected. One end of the adjustable resistor is connected to one end of the first resistor and one end of the second resistor. The other end of the second resistor is connected to the base of the transistor. The collector of the transistor is connected to the negative power input terminal of the relay. The positive power input terminal of the relay is connected to the control power input terminal. The other end of the first resistor is connected to the emitter of the transistor.
6. The full-load detection device for packaging cartons according to claim 1, characterized in that, The time control circuit includes four sets of time control switches that are electrically connected. The power input terminals of two sets of time control switches are connected to each other, and the power input terminals of the other two sets of time control switches are connected to each other.