CN117963280A - A folding system for cartons of random sizes and a control method thereof - Google Patents

Abstract

The invention relates to packaging machinery detection equipment, in particular to a cover folding system of a random-size carton and a control method thereof, which are arranged on a cover folding and carton pushing device and comprise the following steps: the system comprises a PLC control system, an auxiliary detection system and a man-machine interaction system; the cover folding and box pushing device is used for receiving a control command of the PLC control system and executing corresponding movement; the PLC control system is used for receiving parameters of the folding cover box pushing device regulated by the man-machine interaction system, controlling the folding cover box pushing device to execute corresponding movements, obtaining control commands according to detection results of detection equipment in the auxiliary detection system and a sensor of the folding cover box pushing device, sending the control commands to the folding cover box pushing device, and connecting the folding cover box pushing device with the man-machine interaction system through a bus; the invention judges whether the paper boxes are excessively filled to cause the bulge of the paper boxes through the mutual coordination of the visual, mechanical and non-contact sensors, thereby adjusting the folding cover position, realizing wider dynamic adjustment and adapting to the production working conditions of more paper boxes.

Description

A folding system for cartons of random sizes and a control method thereof

Technical Field

The invention relates to packaging machinery detection equipment, in particular to a cover folding system for cartons of random sizes and a control method thereof.

Background technique

With the development of packaging machinery and equipment and the expansion of multiple industries, simple and single folding and sealing machines can no longer meet the needs of the industry. At present, most of the equipment in the industry needs to pre-set the equipment workflow according to the size of the carton, and once the size of the carton changes, the equipment process parameters need to be readjusted, resulting in poor production efficiency and slow production rhythm. In addition, many assembly lines cannot guarantee that all products can use cartons of the same specification. In addition, many industries can produce products with hundreds of cartons in mixed lines. Traditional folding and sealing machines are not suitable for this work scenario. Therefore, the industry urgently needs folding and sealing equipment that can adjust the carton size adaptively.

At present, most of the adaptive equipment commonly used in the industry uses mechanical position to adjust the size of the equipment, or uses low-pressure flexible pressure to achieve the adaptability of the carton size. This structure easily causes the two-side mechanism to clamp the box too tightly, which not only increases the friction, but also easily causes damage to the box. The degree of automation is low, and manual processing is often required, affecting the overall production efficiency. At the same time, due to the low degree of intelligence of the equipment, when the carton is overfilled with items, it will directly damage the carton, causing production waste, reduced cycle time, and even accidents.

Summary of the invention

The purpose of the present invention is to provide a highly automated, intelligent and efficient folding system for random-sized cartons and a control method thereof through the cooperation of visual, mechanical and non-contact sensors, so as to overcome the defects of the above-mentioned equipment in the industry.

The technical solution adopted by the present invention to achieve the above-mentioned purpose is: a folding system for cartons of random sizes, which is arranged on a folding and box pushing device, the folding and box pushing device includes a frame, a box pressing and folding lifting mechanism, a box pushing conveyor line body, a centering and aligning mechanism and a box sealing conveyor line body, wherein the box pushing conveyor line body and the box sealing conveyor line body are arranged at the bottom of the frame at the front and rear; the centering and aligning mechanism is arranged on the frame, and is used to center the box on the box pushing conveyor line body; the box pressing and folding lifting mechanism is arranged on the frame and is located above the box pushing conveyor line body, and the box pressing and folding lifting mechanism is used to fold the box.

The frame includes a main frame and a lifting drive mechanism; the main frame is provided with a distance measuring sensor and a lifting synchronous guide rail slider arranged along the vertical direction; the lifting drive mechanism is arranged on the main frame and connected to the box pressing and folding cover lifting mechanism, and the box pressing and folding cover lifting mechanism is connected to the lifting synchronous guide rail slider.

The lifting drive mechanism includes a folding cover lifting mechanism driving assembly, a driving synchronous wheel, a driven wheel and a lifting synchronous belt, wherein the folding cover lifting mechanism driving assembly is arranged at the top of the main frame, and the output end is connected to the driving synchronous wheel, the driven wheel is arranged at the bottom of the main frame, and is connected to the driving synchronous wheel through the lifting synchronous belt, and the lifting synchronous belt is connected to the box pressing folding cover lifting mechanism.

The box pressing and cover folding lifting mechanism comprises a lifting mechanism frame, a box pressing plate mechanism, a long-arm cover folding mechanism, a short-arm cover folding mechanism, a side cover folding mechanism and a guide pressure plate, wherein the lifting mechanism frame is connected to the lifting drive mechanism through a synchronous belt locking block, and one side of the lifting mechanism frame is connected to the lifting synchronous guide rail slider, and the other side is connected to the main frame through a guide wheel mechanism; the guide pressure plate is arranged at the bottom of the lifting mechanism frame, the long-arm cover folding mechanism is arranged at the front of the lifting mechanism frame, and the short-arm cover folding mechanism is hinged at the end of the long-arm cover folding mechanism; the box pressing plate mechanism is arranged at the bottom of the long-arm cover folding mechanism; the side cover folding mechanism is divided into two groups, and are respectively arranged on both sides of the rear end of the lifting mechanism frame, and the two groups of side cover folding mechanisms are used for folding the side covers of the box.

The long-arm cover folding mechanism comprises a long-arm cylinder and two long-arm side plates, wherein the two long-arm side plates are arranged in parallel and connected by a long-arm side plate connecting shaft; the long-arm cylinder is fixed between the two long-arm side plates by a cylinder fixing seat, and the output end is hinged to the short-arm cover folding mechanism through a long connecting block, and the rear end of the short-arm cover folding mechanism is rotatably connected to the two long-arm side plates through a long-arm rotating shaft.

The short arm folding cover mechanism comprises a short arm side plate, a short arm cylinder, a cylinder fixing seat and a folding cover forearm, wherein two short arm side plates are arranged in parallel and connected by a short arm side plate connecting shaft; the rear ends of the two short arm side plates are connected to the long arm rotating shaft, the short arm cylinder is installed between the two short arm side plates through the cylinder fixing seat, and the output end is hinged to the folding cover forearm through a short connecting block, and the folding cover forearm is hinged to the short arm side plate through the forearm rotating shaft.

The box pressing plate mechanism includes a side bracket plate, an in-position sensor, a pressure plate, a pressure plate fixing block and an actuating cylinder, wherein the two side bracket plates are arranged in parallel and connected by a side bracket plate connecting shaft, and the upper ends of the two side bracket plates are connected to the lifting mechanism frame; the actuating cylinder is arranged between the two side bracket plates, and the output end is connected to the pressure plate fixing block through the cylinder connecting plate, and the pressure plate fixing block is rotatably connected to the two side bracket plates through the pressure plate rotating shaft; the pressure plate is arranged at the bottom of the pressure plate fixing block; an in-position sensor is installed on the side bracket plate through the sensor fixing plate; the in-position sensor is located above the pressure plate fixing block, and is used to detect whether the pressure plate fixing block is rotated into position.

The side cover folding mechanism includes a side folding cover support, a rotating shaft support, a rotating plate, a side arm cylinder, a cylinder fixed shaft and a folding cover rod, wherein the side folding cover support is connected to the lifting mechanism frame, the rotating shaft support is arranged at the top of the side folding cover support, the rotating shaft support is provided with a rotating shaft, the rotating shaft is provided with a rotating shaft bearing seat, the rotating shaft bearing seat is connected to the upper end of the rotating plate, and the lower end of the rotating plate is connected to the folding cover rod; the side arm cylinder is connected to the side folding cover support through the cylinder fixed shaft, the output end of the side arm cylinder is connected to the rotating plate, and the side arm cylinder is used to drive the rotating plate to open outward or close inward.

The box-pushing conveying line includes line side plates, conveying rollers, a push plate, a push plate driving mechanism, a driving assembly I, a driving assembly II, a stop mechanism I, a stop mechanism II and a sensor, wherein a plurality of conveying rollers are arranged between two parallel line side plates; the stop mechanism I and the stop mechanism II are arranged between the two line side plates at intervals in front and rear; the driving assembly I and the driving assembly II are arranged on the line side plates, the driving assembly I is used to drive the conveying rollers before the stop mechanism II to rotate, and the driving assembly II is used to drive the conveying rollers located outside the stop mechanism II to rotate; the push plate driving mechanism is arranged between the stop mechanism I and the stop mechanism II, and is connected to the driving assembly II, and the push plate driving mechanism is used to push the box along the conveying direction of the conveying rollers; the sensor is arranged on the line side plate and corresponds to the stop mechanism I.

The centering and alignment mechanism includes a left-right rotating ball screw slide module, a servo drive motor and two groups of alignment rod assemblies, wherein the left-right rotating ball screw slide module is arranged at the bottom of the two line body side plates and is perpendicular to the line body side plates; the two groups of alignment rod assemblies are respectively connected to the driving ends on both sides of the left-right rotating ball screw slide module, the servo drive motor is connected to the left-right rotating ball screw slide module, and the left-right rotating ball screw slide module drives the two groups of alignment rod assemblies to move closer to or away from each other.

A folding system for cartons of random sizes, comprising: a PLC control system, an auxiliary detection system and a human-computer interaction system;

The folding and pushing device is used as a folding execution device for cartons of random sizes, and is used to receive control commands from the PLC control system and execute corresponding movements according to the control commands from the PLC control system;

The PLC control system is used to receive the parameters of the folding cover and pushing box device adjusted by the human-computer interaction system, and control the folding cover and pushing box device to perform corresponding movements, obtain control commands according to the detection results of the detection equipment in the auxiliary detection system and the distance sensor and the in-position sensor in the folding cover and pushing box device, and send the control commands to the folding cover and pushing box device, and at the same time connect with the human-computer interaction system through the bus;

The auxiliary detection system is used to collect the status signal of the detection equipment, and at the same time, it is combined with the distance sensor and the in-position sensor of the folding cover and box pushing device to feed back the detection results to the PLC control system;

The human-machine interaction system is used to adjust the parameters of the folding cover and box pushing device and send them to the PLC control system, and to display the detection results received and transmitted by the PLC control system.

PLC control system, including: PLC and servo motor limit and origin sensors, cylinder position detection sensors, carton position detection sensors, and push plate position detection sensors connected thereto;

The servo motor limit and origin sensor is used to obtain the maximum and minimum strokes of the motor and locate the starting position of the motor;

The cylinder position detection sensor is used to detect the movement position of the cylinder, and then obtain the action execution status of the cylinder;

The carton position detection sensor is used to feed back a trigger signal when the carton reaches the detection position to the PLC;

The push plate position detection sensor is used to feed back a trigger signal obtained when the push plate reaches a detection point to the PLC.

The servo motor limit and origin sensor is a photoelectric sensor, which is used to detect the servo motor origin positioning and overload limit, and is located on the frame of the folding cover and box pushing device.

The carton position detection sensor is arranged on the side plate of the line body of the folding cover and pushing box device, and is arranged on the same horizontal line as the blocking mechanism II.

The push plate position detection sensor is arranged below the conveying roller of the folding cover and box pushing device, and is arranged in the running direction of the push plate chain, and is arranged just below the end of the short arm folding cover mechanism after the bending action is performed.

The auxiliary detection system includes: an industrial computer and a height detection laser sensor and a width visual detection camera connected thereto;

The height detection laser sensor is arranged on one side of the box pressing plate mechanism of the folding cover and box pushing device, and is used to obtain the distance between the height detection laser sensor and the carton, and send it to the industrial computer;

The installation position of the width visual inspection camera is the same as the installation position of the distance measuring sensor in the folding cover and box pushing device, which is used to visually image the carton, obtain the left and right distance between the centering and alignment mechanism and the carton, and the length of the carton, and send it to the industrial computer;

The industrial computer is connected to the PLC and is used to input the distance between the height detection laser sensor and the carton, the left and right distance between the centering and alignment mechanism and the carton, and the length of the carton into the PLC.

The human-computer interaction system comprises: a structural box and a touch screen, a start button, a reset button and an emergency stop button arranged on the structural box;

The touch screen, start button, reset button and emergency stop button are respectively embedded on one side of the structural box;

The touch screen, start button, reset button and emergency stop button are connected to the PLC of the PLC control system through a bus.

A control method for a cover folding system of a carton of random size comprises the following steps:

1) PLC controls the push plate, box folding and cover lifting mechanism, and centering and aligning mechanism of the folding and cover pushing device to return to zero; the return to zero position of the box folding and cover lifting mechanism and the centering and aligning mechanism is obtained through the servo motor limit and origin sensor and fed back to the PLC;

2) PLC records the maximum stroke H of the current box press cover folding lifting mechanism height and the maximum stroke W of the centering alignment mechanism width according to the zero return position of the box press cover folding lifting mechanism and the centering alignment mechanism;

3) Put the carton into the box pushing conveyor body of the folding and pushing device. When the carton reaches the trigger position of the carton position detection sensor, the height detection laser sensor group obtains the distance H1 between the height detection laser sensor and the carton; at the same time, the width visual detection camera visually images the carton and obtains the left and right distances W1 and W2 between the centering and alignment mechanism and the carton, as well as the carton length La;

4) The auxiliary detection system feeds back the distance H1 between the height detection laser sensor and the carton, the left and right distances W1 and W2 between the centering and alignment mechanism and the carton, and the length La of the carton to the PLC as the detection results; the PLC performs height adjustment and carton width adjustment according to the detection results;

5) After the height adjustment is completed, the push plate is started to push the carton forward. After the push plate triggers the push plate position detection sensor, the long arm folding mechanism and the short arm folding mechanism are started to complete the front and rear folding action of the carton. When the carton moves to the bottom of the side cover folding mechanism, the side cover folding mechanism is started to complete the side cover folding action of the carton;

6) After the carton leaves the folding and pushing device, the PLC control system controls all motors and cylinders to return to the origin and wait.

The PLC performs height adjustment of the carton according to the detection results, specifically:

The PLC controls the box pressing and folding cover lifting mechanism to descend to the in-place sensor trigger position. At this time, the height H2 of the box pressing and folding cover lifting mechanism from the edge of the carton is obtained from the PLC. If the maximum allowable error of the height detection laser sensor and the in-place sensor to obtain the height of the carton is defined as a, then:

If 0≤(H2-H1)≤a, it means that the items in the carton are raised, and the box pressing and folding cover lifting mechanism rises, and the rising distance is: H2-H1;

If (H2-H1)>a, it means that the height of the items in the carton exceeds the preset value, and the PLC controls the box pressing and folding cover lifting mechanism to rise, and the rising distance is a;

If (H2-H1) < 0, it means that there is a gap in the carton, and the box pressing and cover folding lifting mechanism remains stationary.

The PLC performs carton width adjustment according to the detection results, specifically:

Record the maximum stroke W of the centering and aligning mechanism width, obtain the left and right distances W1 and W2 between the centering and aligning mechanism and the carton through the width visual detection camera, and obtain the forward distance of the centering and aligning mechanism: (W-W1-W2)/2;

After the PLC controls the centering and aligning mechanism to move forward, multiple distance measuring sensors are used to determine the centering and aligning mechanism's distance from the carton W0. The minimum allowable distance is defined as b, then:

If W0>b, it proves that the surface of the carton is flat and the centering and alignment mechanism remains stationary;

If W0≤b, it proves that the side of the carton is bulging, and the PLC controls the centering and alignment mechanism to retreat, and the retreat distance is: b-W0.

The present invention has the following beneficial effects and advantages:

1. This method obtains relatively accurate width and height information through non-contact sensors and visual mechanisms, so that the actuator can obtain more accurate action instructions;

2. The present invention can determine whether the carton is overfilled and causes the carton to bulge through the cooperation of visual, mechanical and non-contact sensors, so as to adjust the folding position to achieve a wider range of dynamic adjustment to adapt to the production conditions of more cartons;

3. The present invention can better understand the action completion of actuators such as cylinders and motors through the cooperation of sensors, avoid the use of open-loop control methods such as delay in the program, so as to achieve faster response time and more accurate action feedback, improve efficiency and enhance the controllability of the actuator;

4. The present invention can obtain the length, width and height information of the carton, so that it can better cooperate with production management systems such as MES to achieve production capacity management of all categories of cartons. Compared with traditional single folding equipment or mechanical adaptive equipment, it is more adaptable to intelligent production;

5. The present invention can obtain the length, width and height information of the carton, thereby providing guidance data for subsequent processes such as bundling, tying and stacking, and providing an interface for the intelligent production line.

6. The box pressing and folding cover lifting mechanism with the box folding cover pushing device of the present invention is driven by a servo drive to drive the synchronous belt to lift and lower, and the positioning is more precise. Compared with the pneumatic structure, it is more stable and reliable.

7. The box-pushing device with folding cover of the present invention can accurately measure the width of boxes of different sizes, the surface thickness of objects inside the boxes, and the height of the boxes by the box-pressing plate through distance-measuring sensors. It can accurately read the outer dimensions of the boxes, and transmit the data to the corresponding mechanism to complete the centering, alignment, and folding actions.

8. The box-pressing and folding-cover lifting mechanism with a folding-cover pushing device of the present invention forms a square mechanism as a whole. The box-pressing plate completes the folding of the front cover of the box body. The long-arm cylinder is actuated to complete the short-arm folding cover mechanism to rotate along the rotating shaft and can trigger the rear cover of the box body. The short-arm cylinder is actuated to make the folding cover forearm move along the rotating shaft to complete the folding of the rear cover. The guide pressing plate guides and presses the front and rear covers, so that the cylinders on both sides can move more smoothly after the box body is in place, thereby completing the folding of the covers on both sides.

9. The box pushing conveyor line with the folding cover pushing device of the present invention can quickly transport the box to the specified position, and cooperate with the distance measuring sensor and the box pressing and folding cover lifting mechanism to complete the measurement of the outer dimensions of the box, and at the same time can accurately push large and small boxes to the specified position for folding covers.

10. The box pushing conveyor line and the centering and aligning mechanism of the box pushing device with folding cover of the present invention simultaneously use servo motors to accurately control the moving position of the box.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a general schematic diagram of a cover folding system for a carton of random sizes according to the present invention;

Among them, 10 folding cover and box pushing devices, 20 PLC control systems, 30 auxiliary detection systems, 40 human-computer interaction systems;

Fig. 2 is a schematic diagram of a PLC control system of the present invention;

Among them, 2100PLC, 2101 limit and origin sensor, 2102 cylinder position detection sensor, 2103 carton position detection sensor, 2104 push plate position detection sensor;

FIG3 is a schematic diagram of an auxiliary detection system according to the present invention;

Among them, there are 3100 industrial computer, 3101 height detection laser sensor group, 3102 width visual detection camera;

FIG4 is a schematic diagram of a human-computer interaction system of the present invention;

Among them, 4100 structure box, 4101 touch screen, 4102 start button, 4103 reset button, 4104 emergency stop button;

FIG5 is an overall flow chart of the control method of the present invention;

FIG6 is a flow chart of a height adjustment method of the present invention;

FIG7 is a flow chart of a width adjustment method of the present invention;

FIG8 is an axonometric view of a box-pushing device with a folding cover according to the present invention;

FIG9 is an axonometric view of the frame of the present invention;

10 is an axonometric view of the folding cover lifting mechanism of the pressure box of the present invention;

FIG11 is a schematic structural diagram of a pressure box plate mechanism in the present invention;

FIG12 is a schematic diagram of the structure of the long arm folding cover mechanism and the short arm folding cover mechanism of the present invention;

FIG13 is a schematic structural diagram of the side cover folding mechanism of the present invention;

14 is an axonometric view of the box pusher conveyor line of the present invention;

FIG15 is an axonometric view of the centering and alignment mechanism of the present invention;

16 is an axonometric view of the box sealing conveyor line of the present invention;

Among them, 1 is a frame, 101 is a main frame, 102 is a driving assembly of a folding cover lifting mechanism, 103 is a driving synchronous wheel, 104 is a lifting synchronous belt, 105 is a lifting synchronous guide slider, and 106 is a distance sensor;

2 is a box pressing and folding cover lifting mechanism, 201 is a lifting mechanism frame, 202 is a guide wheel mechanism, 203 is a synchronous belt locking block, 204 is a box pressing plate mechanism, 2041 is a side bracket plate, 2042 is an in-position sensor, 2043 is a sensor fixing plate, 2044 is a cylinder connecting plate, 2045 is a pressing plate rotating shaft, 2046 is a pressing plate, 2047 is a pressing plate fixing block, 2048 is an actuating cylinder, 2049 is a side bracket plate connecting shaft, 205 is a long arm folding cover mechanism, 2051 is a long arm side plate, 2052 is a long arm cylinder, 2053 is a cylinder fixing seat, 2054 is a long connecting block, 2055 is a long arm rotating shaft, 2056 is the long arm side plate connecting shaft, 206 is the short arm folding cover mechanism, 2061 is the short arm side plate, 2062 is the short arm cylinder, 2063 is the cylinder fixed seat, 2064 is the short arm side plate connecting shaft, 2065 is the short connecting block, 2066 is the folding cover forearm, 2067 is the forearm rotating shaft, 207 is the side cover folding cover mechanism, 2071 is the side folding cover support, 2072 is the rotating shaft support, 2073 is the rotating plate rotating shaft, 2074 is the rotating shaft bearing seat, 2075 is the rotating plate, 2076 is the side arm cylinder, 2077 is the cylinder fixed shaft, 2078 is the fixed shaft support, 2079 is the folding cover rod, and 208 is the guide pressure plate;

3 is a push box conveying line body, 301 is a line body side plate, 302 is a conveying roller, 303 is a push plate, 304 is a push plate chain, 305 is a push plate driving sprocket, 306 is a driving assembly I, 307 is a driving assembly II, 308 is a stop mechanism I, 309 is a stop mechanism II, 310 is a sensor, and 311 is a bracket leg;

4 is a center alignment mechanism, 401 is a left-right rotating ball screw slide module, 402 is a servo drive motor, 403 is a bracket fixing plate, 404 is an alignment rod bracket, and 405 is an alignment rod;

5 is a box sealing conveyor line body, 501 is a line body side plate, 502 is a side plate cross brace, 503 is a conveying roller, 504 is a sensor bracket, and 501 is a bracket leg;

6 is the operation display platform; 7 is the distribution box assembly; 8 is the pneumatic assembly.

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in FIG1 , the cover folding system of the present invention comprises a cover folding box pushing device 10 , a PLC control system 20 , an auxiliary detection system 30 , and a human-computer interaction system 40 ;

The folding and pushing device is used as a folding execution device for random-sized cartons, and is used to receive control commands from the PLC control system 20 and perform corresponding movements according to the control commands from the PLC control system 20;

The PLC control system 20 is used to receive the parameters of the folding cover and pushing box device adjusted by the human-machine interaction system 40, and control the folding cover and pushing box device to perform corresponding movements, obtain control commands according to the detection results of the detection equipment in the auxiliary detection system 30 and the distance sensor 106 and the in-position sensor 2042 in the folding cover and pushing box device, and send the control commands to the folding cover and pushing box device, and at the same time connect with the human-machine interaction system 40 through the bus;

The auxiliary detection system 30 is used to collect the detection equipment status signal, and at the same time, the distance sensor 106 and the in-position sensor 2042 of the folding cover and pushing box device 10 are combined to feed back the detection result to the PLC control system 20;

The human-machine interaction system 40 is used to adjust the parameters of the folding cover and box pushing device and send them to the PLC control system 20 , and to display the detection results transmitted by the PLC control system 20 .

As shown in Figure 2, the PLC control system 20 described in the present invention includes PLC2100 and a servo motor limit and origin sensor 2101, a cylinder position detection sensor 2102, a carton position detection sensor 2103, and a push plate position detection sensor 2104 connected thereto; the servo motor limit and origin sensor is used to obtain the maximum and minimum strokes of the motor and to locate the starting position of the motor; the cylinder position detection sensor is used to detect the execution of the cylinder action; the carton position detection sensor 2103 is arranged on the line body side plate 301 of the folding cover and pushing box device, and is arranged on the same horizontal line as the stop mechanism II 309; the push plate position detection sensor 2104 is located below the conveying roller 302 of the folding cover and pushing box device, installed on the side of the push plate 303, and corresponds to the short arm folding mechanism 206 directly below the long arm folding mechanism 205 after the action.

As shown in FIG3 , the auxiliary detection system 30 of the present invention includes an industrial computer 3100 , a height detection laser sensor group 3101 , and a width visual detection camera 3102 ;

The height detection laser sensor 3101 is arranged on one side of the box pressing plate mechanism 204 of the folding cover and box pushing device, and is used to obtain the distance between the height detection laser sensor 3101 and the carton, and send it to the industrial computer 3100;

The installation position of the width visual inspection camera 3102 is the same as the installation position of the distance measuring sensor 106 in the folding cover and pushing box device, which is used to visually image the carton, obtain the left and right distance between the centering and aligning mechanism 4 and the carton, and the length of the carton, and send it to the industrial computer 3100;

The industrial computer 3100 is connected to the PLC2100 and is used to input the distance between the height detection laser sensor 3101 and the carton, the left and right distance between the centering and alignment mechanism 4 and the carton, and the length of the carton into the PLC2100.

As shown in FIG4 , the human-computer interaction system 40 of the present invention includes a structure box 4100 , a touch screen 4101 , a start button 4102 , a reset button 4103 , and an emergency stop button 4104 , and the touch screen and buttons are embedded and installed on the structure box panel;

The touch screen 4101, the start button 4102, the reset button 4103 and the emergency stop button 4104 are respectively embedded on one side of the structure box;

The touch screen 4101 , the start button 4102 , the reset button 4103 and the emergency stop button 4104 are connected to the PLC 2100 of the PLC control system 20 via a bus.

As shown in FIG5 , the control method of the folding system of the random-sized cartons of the present invention can adjust the system control parameters through the human-computer interaction system 40, and perform operations such as start, stop, emergency stop, fault reset, etc., and hand them over to the folding system described above for execution. The specific method is as follows:

1) PLC2100 controls the push plate 303 of the folding cover and box pushing device to return the box folding cover lifting mechanism 2 and the centering and aligning mechanism 4 to zero movement; the return to zero position of the box folding cover lifting mechanism 2 and the centering and aligning mechanism 4 is obtained through the servo motor limit and origin sensor 2101 and fed back to PLC2100;

2) PLC2100 records the maximum stroke H of the height of the box-pressing and folding cover lifting mechanism 2 and the maximum stroke W of the width of the centering and aligning mechanism 4 according to the zero return positions of the box-pressing and folding cover lifting mechanism 2 and the centering and aligning mechanism 4;

3) Put the carton into the box pushing conveyor 3 of the folding and pushing device 10. When the carton reaches the trigger position of the carton position detection sensor 2103, the height detection laser sensor group 3101 obtains the distance H1 between the height detection laser sensor 3101 and the carton; at the same time, the width visual detection camera 3102 visually images the carton and obtains the left and right distances W1 and W2 between the centering and alignment mechanism 4 and the carton, as well as the carton length La;

4) The auxiliary detection system 30 feeds back the distance H1 between the height detection laser sensor 3101 and the carton, the left and right distances W1 and W2 between the centering and alignment mechanism 4 and the carton, and the length La of the carton as detection results to PLC2100; PLC2100 performs height adjustment and carton width adjustment according to the detection results;

5) After the height adjustment is completed, the push plate 303 is started to push the carton forward. After the push plate 303 triggers the push plate position detection sensor 2104, the long arm folding mechanism 205 and the short arm folding mechanism 206 are started to complete the front and rear folding action of the carton. When the carton moves to the bottom of the side cover folding mechanism 207, the side cover folding mechanism 207 is started to complete the side cover folding action of the carton;

6) After the carton leaves the folding and pushing device, the PLC control system 20 controls all motors and cylinders to return to the origin and wait.

As shown in Figure 6, PLC2100 performs carton height adjustment according to the detection results, specifically:

PLC2100 controls the box pressing and folding cover lifting mechanism 2 to descend to the trigger position of the in-place sensor 2042. At this time, the height H2 of the box pressing and folding cover lifting mechanism 2 from the edge of the carton is obtained from PLC2100. If the maximum error allowed by the height detection laser sensor 3101 and the in-place sensor 2042 to obtain the height of the carton is defined as a, then:

If 0≤(H2-H1)≤a, it means that the items in the carton are raised, and the box pressing and folding cover lifting mechanism 2 rises, and the rising distance is: H2-H1;

If (H2-H1)>a, it means that the height of the items in the carton exceeds the preset value, and PLC2100 controls the box pressing and folding cover lifting mechanism 2 to rise, and the rising distance is a;

If (H2-H1)<0, it means that there is a gap in the carton, and the box pressing and cover folding lifting mechanism 2 remains stationary.

As shown in FIG7 , PLC2100 performs the width adjustment of the carton according to the detection result, specifically:

Record the maximum stroke W of the centering and aligning mechanism 4, obtain the left and right distances W1 and W2 between the centering and aligning mechanism and the carton through the width visual detection camera 3102, and obtain the forward distance of the centering and aligning mechanism 4 as: (W-W1-W2)/2;

After PLC2100 controls the centering and aligning mechanism 4 to move forward, multiple distance measuring sensors 106 are used to determine the distance between the centering and aligning mechanism 4 and the carton W0, and the minimum allowable distance is defined as b, then:

If W0>b, it proves that the surface of the carton is flat and the centering and aligning mechanism 4 remains stationary;

If W0≤b, it proves that the side of the carton is bulging, and PLC2100 controls the centering and alignment mechanism 4 to retreat, and the retreat distance is: b-W0.

As shown in Figure 8, the present invention provides a box pushing device with folding cover, which includes a frame 1, a box pressing and folding cover lifting mechanism 2, a box pushing conveyor line 3, a centering and aligning mechanism 4 and a box sealing conveyor line 5, wherein the box pushing conveyor line 3 and the box sealing conveyor line 5 are arranged at the bottom of the frame 1 in front and rear; the centering and aligning mechanism 4 is arranged on the frame 1, and is used to center the box on the box pushing conveyor line 3; the box pressing and folding cover lifting mechanism 2 is arranged on the frame 1, and is located above the box pushing conveyor line 3, and the box pressing and folding cover lifting mechanism 2 is used to fold the cover of the box.

As shown in FIG9 , in an embodiment of the present invention, the frame 1 includes a main frame 101 and a lifting drive mechanism; the main frame 101 is provided with a distance sensor 106 and a lifting synchronous guide slider 105 arranged in the vertical direction; the lifting drive mechanism is arranged on the main frame 101 and connected to the box pressing and folding cover lifting mechanism 2, and the box pressing and folding cover lifting mechanism 2 is connected to the lifting synchronous guide slider 105. The distance sensor 106 is fixed to both sides of the small frame in front of the main frame 101 by screws, and the distance sensor 106 can be disassembled by opening the protective door, which is convenient and quick. Specifically, three groups of distance sensors 106 are used to measure the width and height directions of boxes of different sizes.

Specifically, the lifting drive mechanism includes a folding cover lifting mechanism drive assembly 102, a driving synchronous wheel 103, a driven wheel and a lifting synchronous belt 104, wherein the folding cover lifting mechanism drive assembly 102 is arranged at the top middle position of the main frame 101, and the output end is connected to the transmission shaft, and driving synchronous wheels 103 are provided at both ends of the transmission shaft. Two driven wheels are arranged at the bottom of the main frame 101, and are respectively connected to the two driving synchronous wheels 103 through two lifting synchronous belts 104. The two lifting synchronous belts 104 are connected to the box pressing folding cover lifting mechanism 2, and the box pressing folding cover lifting mechanism 2 rises and falls along with the lifting synchronous belt 104.

As shown in FIG10 , in the embodiment of the present invention, the box pressing and folding cover lifting mechanism 2 comprises a lifting mechanism frame 201, a box pressing plate mechanism 204, a long arm folding cover mechanism 205, a short arm folding cover mechanism 206, a side cover folding cover mechanism 207 and a guide pressure plate 208, wherein the lifting mechanism frame 201 is connected to the lifting synchronous belt 104 of the lifting drive mechanism through a synchronous belt locking block 203, and one side of the lifting mechanism frame 201 is connected to the lifting synchronous guide slider 105, and the other side is connected to the main frame 101 through a guide wheel mechanism 202; the guide pressure plate 208 is arranged on the lifting mechanism frame 201. At the bottom of the lowering mechanism frame 201, the long-arm folding mechanism 205 is arranged at the front part of the lifting mechanism frame 201, and the short-arm folding mechanism 206 is hinged at the end of the long-arm folding mechanism 205; the long-arm folding mechanism 205 and the short-arm folding mechanism 206 cooperate to complete the folding of the front cover of the box body; the box pressing plate mechanism 204 is arranged at the bottom of the long-arm folding mechanism 205, and is used to realize the folding and positioning of the front cover of the box body; the side cover folding mechanism 207 is divided into two groups, and is respectively arranged on both sides of the rear end of the lifting mechanism frame 201, and the two groups of side cover folding mechanisms 207 are used for folding the side covers of the box body.

As shown in Figure 11, in an embodiment of the present invention, the box pressing plate mechanism 204 includes a side bracket plate 2041, an in-position sensor 2042, a pressure plate 2046, a pressure plate fixing block 2047 and an actuating cylinder 2048, wherein the two side bracket plates 2041 are arranged in parallel and connected by a side bracket plate connecting shaft 2049, and the upper ends of the two side bracket plates 2041 are connected to the lifting mechanism frame 201; the actuating cylinder 2048 is arranged between the two side bracket plates 2041, and the output end is connected to the pressure plate fixing block 2047 through the cylinder connecting plate 2044, and the pressure plate fixing block 2047 is rotatably connected to the two side bracket plates 2041 through the pressure plate rotating shaft 2045; the pressure plate 2046 is arranged at the bottom of the pressure plate fixing block 2047; the in-position sensor 2042 is installed on the side bracket plate 2041 through the sensor fixing plate 2043; the in-position sensor 2042 is located above the pressure plate fixing block 2047, and is used to detect whether the pressure plate fixing block 2047 is rotated into position.

As shown in Figure 12, in an embodiment of the present invention, the long arm folding mechanism 205 includes a long arm cylinder 2052 and two long arm side plates 2051, wherein the two long arm side plates 2051 are arranged in parallel and connected by a long arm side plate connecting shaft 2056; the long arm cylinder 2052 is fixed between the two long arm side plates 2051 through a cylinder fixing seat 2053, and the output end is hinged to the short arm folding mechanism 206 through a long connecting block 2054, and the rear end of the short arm folding mechanism 206 is rotatably connected to the two long arm side plates 2051 through a long arm rotating shaft 2055.

The short arm folding cover mechanism 206 includes a short arm side plate 2061, a short arm cylinder 2062, a cylinder fixing seat 2063 and a folding cover forearm 2066, wherein the two short arm side plates 2061 are arranged in parallel and connected by a short arm side plate connecting shaft 2064; the rear ends of the two short arm side plates 2061 are connected to the long arm rotating shaft 2055, the short arm cylinder 2062 is installed between the two short arm side plates 2061 through the cylinder fixing seat 2063, and the output end is hinged to the folding cover forearm 2066 through the short connecting block 2065, and the folding cover forearm 2066 is hinged to the short arm side plate 2061 through the forearm rotating shaft 2067.

During operation, the long arm cylinder 2052 drives the short arm folding cover mechanism 206 to rotate around the long arm rotating shaft 2055; the short arm cylinder 2062 drives the folding cover forearm 2066 to rotate around the forearm rotating shaft 2067, thereby realizing the folding cover action of the rear cover of the box body.

As shown in FIG. 13 , in the embodiment of the present invention, the two sets of side cover folding mechanisms 207 are mainly used to complete the folding action of the two side covers of the box body. The side cover folding mechanism 207 includes a side folding cover support 2071, a rotating shaft support 2072, a rotating plate 2075, a side arm cylinder 2076, a cylinder fixed shaft 2077 and a folding cover rod 2079, wherein the side folding cover support 2071 is connected to the lifting mechanism frame 201, the rotating shaft support 2072 is arranged at the top of the side folding cover support 2071, the rotating shaft support 2072 is provided with a rotating shaft, and the rotating shaft is provided with a rotating shaft bearing seat 2074, the rotating shaft bearing seat 2074 is connected to the upper end of the rotating plate 2075, and the lower end of the rotating plate 2075 is connected to the folding cover rod 2079; the side arm cylinder 2076 is connected to the side folding cover support 2071 through the cylinder fixed shaft 2077, the output end of the side arm cylinder 2076 is connected to the rotating plate 2075, and the side arm cylinder 2076 is used to drive the rotating plate 2075 to open outward or close inward.

As shown in FIG14 , in an embodiment of the present invention, a box-pushing conveying line body 3 is fixed to the lower long crossbeam of the frame body 1 by a bracket leg 311, and the box-pushing conveying line body 3 includes a line body side plate 301, a conveying roller 302, a push plate 303, a push plate driving mechanism, a driving assembly I 306, a driving assembly II 307, a stop mechanism I 308, a stop mechanism II 309 and a sensor 310, wherein a plurality of conveying rollers 302 are arranged between two parallel line body side plates 301, and the conveying rollers 302 are connected by a chain to facilitate the transmission of power; the stop mechanism I 308 and the stop mechanism II 309 are arranged at intervals between the two line body side plates 301 in front and in the back, and the stop mechanism Structure I 308 is used for dividing materials, and the stop mechanism II 309 is used for pressing the box and folding the cover; the driving assembly I 306 and the driving assembly II 307 are arranged on the side plate 301 of the line body, the driving assembly I 306 is used to drive the conveying roller 302 before the stop mechanism II 309 to rotate, and the driving assembly II 307 is used to drive the conveying roller 302 located after the stop mechanism II 309 to rotate; the push plate driving mechanism is arranged between the stop mechanism I 308 and the stop mechanism II 309, and is connected to the driving assembly II 307, and the push plate driving mechanism is used to push the box along the conveying direction of the conveying roller 302; the sensor 310 is arranged on the side plate 301 of the line body and corresponds to the stop mechanism I 308.

Specifically, the push plate driving mechanism includes a push plate 303 and a push plate chain 304. The push plate chain 304 is arranged along the conveying direction of the conveying roller 302, and the push plate chain 304 is connected to the driving shaft of the driving assembly II 307. The push plate 303 is fixed to the push plate chain 304 by screws. When the driving assembly II 307 drives the conveying roller 302 behind the stop mechanism II 309 to rotate, it also drives the push plate chain 304 to rotate, so that the push plate 303 completes the pushing work of the box. The push plate 303 has an origin sensor and a long and short box positioning and folding cover sensor, which can realize the automatic folding cover of the long and short boxes, thereby preventing damage to the box.

As shown in Figure 15, in an embodiment of the present invention, the centering and alignment mechanism 4 includes a left-right rotating ball screw slide module 401, a servo drive motor 402 and two groups of alignment rod assemblies, wherein the left-right rotating ball screw slide module 401 is arranged at the bottom of the two line body side plates 301, and is perpendicular to the line body side plates 301; the two groups of alignment rod assemblies are respectively connected to the driving ends on both sides of the left-right rotating ball screw slide module 401, and the servo drive motor 402 is connected to the left-right rotating ball screw slide module 401 through a coupling, and the left-right rotating ball screw slide module 401 drives the two groups of alignment rod assemblies to move closer to or away from each other.

Specifically, the alignment rod assembly includes a bracket fixing plate 403, an alignment rod bracket 404 and an alignment rod 405, wherein the bracket fixing plate 403 is connected to the left-right rotating ball screw slide module 401, and the two ends of the bracket fixing plate 403 are provided with alignment rod brackets 404, and the tops of the two alignment rod brackets 404 are connected to the alignment rod 405. The alignment rod 405 slides back and forth on the left-right rotating ball screw slide module 401 with the help of the gap between the conveying rollers 302 on the push box conveyor line 3. The centering alignment mechanism 4 can realize the centering and alignment of the box according to the transmitted signal. The left-right rotating ball screw slide module 401 has two sets of mechanical limits or sensor limits to prevent the centering alignment mechanism 4 from getting stuck or moving too much.

As shown in FIG16 , in the embodiment of the present invention, the box sealing conveyor line 5 is fixed to the tail of the frame 1 by the bracket leg 505. The line body side plate 501 of the box sealing conveyor line 5 is fixed by the side plate cross brace 502, the conveying roller 503 is fixed on the line body side plate 501, the sensor bracket 504 is fixed on the line body side plate 501, and the bracket leg 505 is fixed on the side plate cross brace 502, so that the box can be sealed on the line body.

As shown in FIG8 , in an embodiment of the present invention, an operation display platform 6 is provided at the upper front end of the frame 1 to facilitate operation by personnel, a distribution box assembly 7 is provided at the rear of the frame 1 , and a pneumatic assembly 8 is provided at the front end of the rear of the frame 1 .

The working principle of the folding cover and box pushing device is:

The boxes delivered via the box pushing conveyor line 3 are divided at the stopping mechanism I 308, and the distance sensor 106 measures the thickness at the same time; when the box reaches the stopping mechanism II 309, the distance sensor 106 on the frame 1 measures the width of the box, and the data value is instantly transmitted to the centering and aligning mechanism 4 to realize the centering and aligning action. At the same time, the box pressing and folding lifting mechanism 2 moves downward, and the pressing plate fixing block 2047 in the box pressing plate mechanism 204 triggers the in-place sensor 2042. The in-place sensor 2042 detects that the pressing plate 2046 is in place, and the front cover folding is completed. According to the data given by the distance sensor 106, the box pressing plate mechanism 204 is raised to the surface of the box object, and the stopping mechanism II 309 releases the box, and the drive assembly II 307 drives the pushing plate 303 to move, and the box is pushed to the fixed position of the large and small boxes. The long arm cylinder 2052 of the long arm cover folding mechanism 205 moves, the short arm cover folding mechanism 206 rotates around the long arm rotating shaft 2055, and the short arm cylinder 2062 of the short arm cover folding mechanism 206 moves, driving the cover folding forearm 2066 to rotate around the forearm rotating shaft 2067, and completing the cover folding of the rear cover of the box. The box is pushed by the push plate 303, and the front and rear covers of the box are pressed by the guide pressing plate 208. When the box triggers the sensor, the side cover cover folding mechanism 207 realizes the cover folding action of the two side covers of the box through the rotating shaft, completing all the cover folding actions of the box, and at the same time the guide pressing plate 208 plays a guiding role to prevent the box from tilting, and finally transported to the box sealing conveying line 5 for the box sealing operation.

The present invention uses visual, mechanical and non-contact sensors to cooperate with each other and be applied to a folding and pushing device to determine whether a carton is overfilled and causes the carton to bulge, thereby adjusting the folding position to achieve a wider range of dynamic adjustment to adapt to the production conditions of more cartons.

The present invention can better understand the action completion degree of the cylinder, motor and other actuators of the folding cover and box pushing device through the cooperation of sensors, avoid using open-loop control means such as delay in the program, so as to achieve faster response time and more accurate action feedback, improve efficiency and enhance the controllability of the actuator;

The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, expansion, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A cover folding system for cartons of random sizes, arranged on a cover folding and box pushing device, characterized in that it comprises: a PLC control system (20), an auxiliary detection system (30) and a human-computer interaction system (40); The folding and box pushing device is used as a folding execution device for cartons of random sizes, and is used to receive control commands from a PLC control system (20) and execute corresponding movements according to the control commands from the PLC control system (20); The PLC control system (20) is used to receive parameters of the folding cover and pushing box device adjusted by the human-machine interaction system (40), and control the folding cover and pushing box device to perform corresponding movements, obtain control commands based on the detection results of the detection equipment in the auxiliary detection system (30) and the distance measuring sensor (106) and the in-position sensor (2042) in the folding cover and pushing box device, and send the control commands to the folding cover and pushing box device, and at the same time be connected to the human-machine interaction system (40) through a bus; The auxiliary detection system (30) is used to collect the detection equipment status signal, and at the same time, in combination with the distance sensor (106) and the in-position sensor (2042) of the folding cover and box pushing device (10), the detection result is fed back to the PLC control system (20); The human-machine interaction system (40) is used to adjust the parameters of the folding cover and box pushing device and send them to the PLC control system (20), and to display the detection results received and transmitted by the PLC control system (20). 2. A folding system for cartons of random sizes according to claim 1, characterized in that the PLC control system (20) comprises: a PLC (2100) and a servo motor limit and origin sensor (2101), a cylinder position detection sensor (2102), a carton position detection sensor (2103), and a push plate position detection sensor (2104) connected thereto; The servo motor limit and origin sensor (2101) is used to obtain the maximum and minimum strokes of the motor and locate the starting position of the motor; The cylinder position detection sensor (2102) is used to detect the movement position of the cylinder, and then obtain the action execution status of the cylinder; The carton position detection sensor (2103) is used to feed back a trigger signal when the carton reaches the detection position to the PLC (2100); The push plate position detection sensor (2104) is used to feed back the trigger signal obtained when the push plate (303) reaches the detection point to the PLC (2100). 3. A cover folding system for cartons of random sizes according to claim 2, characterized in that the servo motor limit and origin sensor (2101) is a photoelectric sensor, which is used to detect the servo motor origin positioning and overload limit, and is located on the frame (1) of the cover folding and box pushing device. 4. A folding system for cartons of random sizes according to claim 2, characterized in that the carton position detection sensor (2103) is arranged on the line side plate (301) of the folding and pushing device (10), and is arranged on the same horizontal line as the stop mechanism II (309). 5. A folding system for cartons of random sizes according to claim 2, characterized in that the push plate position detection sensor (2104) is arranged below the conveying roller (302) of the folding and box pushing device (10), and is arranged in the running direction of the push plate chain (304), and is arranged directly below the end of the short arm folding mechanism (206) after the bending action is performed. 6. A folding system for cartons of random sizes according to claim 1, characterized in that the auxiliary detection system (30) comprises: an industrial computer (3100) and a height detection laser sensor (3101) and a width visual detection camera (3102) connected thereto; The height detection laser sensor (3101) is arranged on one side of the box pressing plate mechanism (204) of the folding cover and box pushing device (10), and is used to obtain the distance between the height detection laser sensor (3101) and the carton, and send it to the industrial computer (3100); The width visual detection camera (3102) is installed at the same position as the distance measuring sensor (106) in the folding cover and box pushing device (10), and is used to visually image the carton, obtain the left and right distance between the centering and alignment mechanism (4) and the carton, and the length of the carton, and send it to the industrial computer (3100); The industrial computer (3100) is connected to the PLC (2100) and is used to input the distance between the height detection laser sensor (3101) and the carton, the left and right distance between the centering and alignment mechanism (4) and the carton, and the length of the carton into the PLC (2100). 7. The cover folding system for cartons of random sizes according to claim 1, characterized in that the human-computer interaction system (40) comprises: a structural box (4100) and a touch screen (4101), a start button (4102), a reset button (4103) and an emergency stop button (4104) arranged on the structural box (4100); The touch screen (4101), the start button (4102), the reset button (4103) and the emergency stop button (4104) are respectively embedded on one side of the structural box; The touch screen (4101), the start button (4102), the reset button (4103) and the emergency stop button (4104) are connected to the PLC (2100) of the PLC control system (20) via a bus. 8. The method for controlling a cover folding system for cartons of random sizes according to claim 1, characterized in that it comprises the following steps: 1) The PLC (2100) controls the push plate (303) of the folding cover and pushing box device (10), the box pressing and folding cover lifting mechanism (2), and the centering and aligning mechanism (4) to return to zero; the return to zero position of the box pressing and folding cover lifting mechanism (2) and the centering and aligning mechanism (4) is obtained through the servo motor limit and origin sensor (2101) and fed back to the PLC (2100); 2) The PLC (2100) records the current maximum stroke H of the height of the box-pressing and folding cover lifting mechanism (2) and the maximum stroke W of the width of the centering and aligning mechanism (4) according to the zero return positions of the box-pressing and folding cover lifting mechanism (2) and the centering and aligning mechanism (4); 3) A carton is placed into the carton pushing conveyor (3) of the folding lid and pushing device (10). When the carton reaches the trigger position of the carton position detection sensor (2103), the height detection laser sensor group (3101) obtains the distance H1 between the height detection laser sensor (3101) and the carton; at the same time, the width visual detection camera (3102) forms a visual image of the carton and obtains the left and right distances W1 and W2 between the centering and alignment mechanism (4) and the carton, as well as the length La of the carton; 4) The auxiliary detection system (30) feeds back the distance H1 between the height detection laser sensor (3101) and the carton, the left and right distances W1 and W2 between the centering and alignment mechanism (4) and the carton, and the length La of the carton as detection results to the PLC (2100); the PLC (2100) performs height adjustment and carton width adjustment according to the detection results; 5) After the height adjustment is completed, the push plate (303) is started to push the carton forward. After the push plate (303) triggers the push plate position detection sensor (2104), the long arm folding mechanism (205) and the short arm folding mechanism (206) are started to complete the front and rear folding action of the carton. When the carton moves to the bottom of the side cover folding mechanism (207), the side cover folding mechanism (207) is started to complete the side cover folding action of the carton; 6) When the carton leaves the folding and pushing device (10), the PLC control system (20) controls all motors and cylinders to return to the origin and wait. 9. The control method of a folding system for a carton of random sizes according to claim 8, characterized in that the PLC (2100) performs height adjustment of the carton according to the detection result, specifically: The PLC (2100) controls the box pressing and folding cover lifting mechanism (2) to descend to the trigger position of the in-place sensor (2042). At this time, the height H2 of the box pressing and folding cover lifting mechanism (2) from the edge of the carton is obtained from the PLC (2100). If the maximum allowable error of the height of the carton obtained by the height detection laser sensor (3101) and the in-place sensor (2042) is defined as a, then: If 0≤(H2-H1)≤a, it means that the articles in the carton are raised, and the box pressing and cover folding lifting mechanism (2) rises, and the rising distance is: H2-H1; If (H2-H1)>a, it means that the height of the articles in the carton exceeds the preset value, and the PLC (2100) controls the box pressing and folding cover lifting mechanism (2) to rise, and the rising distance is a; If (H2-H1)<0, it means that there is a gap in the carton, and the box pressing and cover folding lifting mechanism (2) remains stationary. 10. The control method of a folding system for a carton of random sizes according to claim 8, characterized in that the PLC (2100) performs width adjustment of the carton according to the detection result, specifically: Record the maximum travel W of the width of the centering and aligning mechanism (4), obtain the left and right distances W1 and W2 between the centering and aligning mechanism and the carton through the width visual detection camera (3102), and obtain the forward distance of the centering and aligning mechanism (4): (W-W1-W2)/2; After the PLC (2100) controls the centering and aligning mechanism (4) to move forward, the distance between the centering and aligning mechanism (4) and the carton W0 is determined by a plurality of distance measuring sensors (106), and the minimum allowable distance is defined as b, then: If W0>b, it proves that the surface of the carton is flat and the centering and aligning mechanism (4) remains stationary; If W0≤b, it means that the side of the carton is bulging, and the PLC (2100) controls the centering and alignment mechanism (4) to move backward, and the backward distance is: b-W0.