Paper jam detection method of paper folding machine

Abstract

The invention discloses a paper jam detection method for a paper folding machine, a feeding end and a discharging end of the paper folding machine are provided with sensors used for detecting paper, the detection method comprises the following steps: S1, according to the running speed of the paper folding machine and the length of the paper before and after folding, the feeding time T1 and the discharging time T2 of the paper are calculated; when the paper folding machine runs, the sensor actually senses the feeding time t1 and the discharging time t2, if the difference value between the actual time and the calculation time is within a set range, it is judged that feeding or discharging is conducted, and otherwise, it is judged that an interference item exists; s2, judging whether paper is jammed or not according to the time interval between feeding and discharging or the maximum folded paper number X calculated in the paper folding machine; according to the invention, the paper jam fault of the folding machine is accurately judged, the safety and stability of the folding machine in the production process are ensured, the service life of the folding machine is prolonged, the economic benefit of the product is improved, the fault time of the folding machine is shortened, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of paper folding machines, and in particular to a paper jam detection method for paper folding machines. Background Art

[0002] The fully automatic online high-speed folding machine is a key equipment on the pharmaceutical production line. The production efficiency of one automatic folding machine is equivalent to that of 10 skilled operators. The specifications are automatically switched and folded, and the workstations are automatically counted, which greatly improves production efficiency and quality. The research and development of automatic folding will also promote the research of key technologies such as high-speed pharmaceutical automation intelligent packaging control systems, precision processing technology, and materials science. It is of great significance to catch up with developed countries and improve the automation level of pharmaceutical safety production line detection in my country. During the high-speed operation of the folding machine, the folding machine will jam due to mechanical jitter, deterioration of paper quality or other unstable factors. The jam will cause a large amount of paper to accumulate in a short time. Taking the speed of 400 sheets / minute as an example, if the folding machine jams, 20 instructions will be accumulated in the folding machine in just 3 seconds, which will cause great harm to the machine and production.

[0003] In the prior art, for detecting paper jams, the method described in the FOCKE350 packaging machine cigarette pack paper jam detection device with patent number CN213316284U is used. If the number of paper input and output is equal, it means there is no paper jam, otherwise there is a paper jam. However, in actual working process, this paper jam detection method is easily interfered by the outside world. For example, the shadow cast by someone passing by the sensor can trigger the sensor to count. The present invention provides a new technical solution to the paper jam detection interference in the existing detection method. Summary of the invention

[0004] The purpose of the invention is to provide a paper jam detection method for a paper folding machine, which solves the problem that paper jam detection in the prior art is easily disturbed.

[0005] The present invention is implemented as follows: a paper jam detection method for a paper folding machine, wherein sensors for detecting paper are provided at the feeding end and the discharging end of the paper folding machine, and the detection method comprises the following steps:

[0006] S1. Calculate the feeding time T1 and discharging time T2 of the paper according to the running speed of the paper folding machine and the length of the paper before and after folding; when the paper folding machine is running, the feeding time t1 and discharging time t2 actually sensed by the sensor, if the difference between the actual time and the calculated time is within the set range, it is judged that the paper has been fed or discharged, otherwise it is judged as an interference item;

[0007] S2. Determine whether there is a paper jam based on the time interval between feeding and discharging or by calculating the maximum number of folded papers X in the folding machine.

[0008] In actual application, there will be some interference factors that will affect the detection of the sensor. For example, when someone passes by, the sensor may respond and think that there is paper in and out, which can easily cause a false alarm of a paper jam alarm. In the present invention, the paper feeding time and discharging time are first calculated, and then the feeding time and discharging time actually sensed by the sensor are compared with the calculated time. If the time difference is within the allowed range, it is determined that the signal sensed by the sensor is paper, otherwise it is determined to be an interference signal, thereby ensuring that the sensor detects paper rather than other interference items. When it is determined that the signal at the feeding end is paper, the controller starts timing. When the paper is output from the output end of the paper folding machine after folding, the controller stops timing when it is determined that the signal at the discharging end is paper. If the time difference between feeding and discharging is within the set range, it is determined to be normal operation. If the sensor at the discharging end has not sensed the paper discharging information for more than the set time, it is determined to be a paper jam.

[0009] In addition to using the time difference to determine whether there is a paper jam, the number of sheets of paper in the paper folding machine can also be used to determine whether there is a paper jam. Specifically, when the signal at the feed end is determined to be paper, the count value is increased by one. When the paper is output from the output end of the paper folding machine after folding, the count value is reduced by one when the signal at the discharge end is determined to be paper. If the count value is within the set range, it is determined to be normal operation. If the count value is greater than the maximum number of folded paper in the paper folding machine, X, it is determined to be a paper jam. This paper jam detection method uses the signal of the photoelectric sensor as a counting pulse to accurately calculate the actual number of folds.

[0010] The present invention utilizes two photoelectric sensors as paper incoming and outgoing material detection. The PLC calculates the production speed of the folding machine to match the scanning time of the photoelectric sensors. By detecting the feeding and outgoing material, it is determined whether there is paper stuck inside the folding machine. The present invention realizes accurate judgment of paper jam failure of the folding machine, ensures the safety and stability of the folding machine in the production process, prolongs the service life of the folding machine, improves the economic benefits of the product, reduces the failure time of the folding machine, and reduces the production cost.

[0011] The paper jam detection method needs to match different production speeds. Usually, the speed of the folding machine is 200-400 sheets / minute, so the scanning time of the photoelectric detection sensor for feeding and discharging needs to match the production speed of the folding machine, otherwise it will cause false alarms or missed alarms. In the present invention, the scanning time of the photoelectric sensors for feeding and discharging can be controlled according to the production speed of the folding machine. If no paper is detected during the respective scanning time, an alarm signal is generated to stop the folding machine. The present invention is adapted to various production speeds of the folding machine, eliminating the malfunction of the photoelectric sensor caused by the fixed scanning time, and ensuring the production safety and production quality of the folding machine.

[0012] In the present invention, the photoelectric sensor at the feed end is used to detect whether there is paper entering the folder, and the photoelectric sensor at the discharge end is used to detect whether there is paper being delivered to the downstream equipment.

[0013] The PLC program uses the corresponding algorithm to calculate the scanning time of the photoelectric sensors for feeding and discharging and the time required to fold a piece of paper based on the production speed, the length of the paper before and after folding, and the folding method. During the folding process of a piece of paper, if the photoelectric sensor at the feeding end scans the paper within the scanning time, it will wait for the trigger signal from the photoelectric sensor at the discharging end that scans the paper. If the waiting time exceeds the calculated folding time, it is judged that the folding machine is jammed and the folding machine is stopped.

[0014] A further technical solution of the present invention is: in step S1, the calculation of the feeding time T1 and the discharging time T2 in the algorithm is: the feeding time T1 is equal to the length of the paper before folding divided by the running speed; the discharging time T2 is equal to the length of the paper after folding divided by the running speed. Considering the interference of the sensor's own accuracy, the allowable error is Δt, so if the difference between the actual time and the calculated time is less than Δt, it is judged that the paper has been fed or discharged.

[0015] A further technical solution of the present invention is: in step S1, the sensing time of the sensor at the feeding end is the feeding time t1, and the sensing time of the sensor at the discharging end is the discharging time t2. That is, when a material passes through the sensor, the sensor's sensing signal will be triggered, and the duration of the sensing signal at the feeding end is recorded as t1, and the duration of the sensing signal at the discharging end is recorded as t2.

[0016] A further technical solution of the present invention is: when the difference between the feeding time T1 and the feeding time t1 in step S1 is within the set range, it is judged that the feeding has been completed; when the difference between the discharging time T2 and the discharging time t2 is within the set range, it is judged that the discharging has been completed. Theoretically, when T1=t1, it is judged that the feeding has been completed, and when T2=t2, it is judged that the discharging has been completed. Considering the accuracy error of the sensor in the actual working process, the allowable error range Δt is set. Therefore, when the difference between T1 and t1 is within the range of Δt, it is determined that the feeding has been completed. Similarly, when the difference between T2 and t2 is within the error range, it is determined that the discharging has been completed; in this way, the judgment accuracy and anti-interference ability are improved.

[0017] A further technical solution of the present invention is: according to the running speed of the paper folding machine and the length of the paper to be folded, the time T3 required for paper folding is calculated. In the step S2, the folding time t is recorded when the paper has been fed; if the folding time t exceeds the required time T3 and the sensor does not detect the discharge, it is determined to be a paper jam. Specifically, the timing is started when it is sensed that the feeding end of the paper folding machine has fed the paper, and within the time required for paper folding, the discharge end of the paper folding machine senses the discharge of the paper, and it is determined that the paper folding machine is operating normally; when the discharge end of the paper folding machine does not have a discharge signal after the time required for paper folding, it is determined to be a paper jam.

[0018] A further technical solution of the present invention is: in the step S2, if the difference between the number of sheets of paper fed and the number of sheets of paper discharged is greater than the maximum set value of the number of sheets of paper folded in the paper folding machine, it is determined that there is a paper jam. In addition to using the time interval to determine whether there is a paper jam, the number of sheets of paper can also be used to determine whether there is a paper jam. Specifically, when the feed end and the discharge end of the paper folding machine sense a signal that the paper has been fed or discharged, the digital input module connected to the controller starts counting, the digital input module input is increased by one when the paper has been fed, and the digital input module input is decreased by one when the paper has been discharged. The PLC controller connected to the digital input module obtains the number of sheets of paper in the paper folding machine based on the digital information. When the number of sheets of paper is greater than the set maximum number of sheets of paper folded in the paper folding machine, it is determined that there is a paper jam.

[0019] A further technical solution of the present invention is: in step S2, the sensor signal is recorded in the form of counting pulses, and when the difference between the number of fed signals and the number of discharged signals is greater than the maximum setting value of the controller, it is determined to be a paper jam.

[0020] A further technical solution of the present invention is that the detection method further comprises step S3. When a paper jam is detected, an alarm signal is issued and the paper folding machine is shut down. This solution improves the utilization rate of paper, the qualified rate of paper folding and the production quality of downstream equipment by timely stopping the machine due to a paper jam alarm.

[0021] Beneficial effects of the present invention: In order to solve this working condition, a paper jam detection method is adopted, and two photoelectric sensors are used as incoming and outgoing material detection of the manual. The PLC calculates the production speed of the folding machine and matches the scanning time of the photoelectric sensor. Through the detection of feeding and outgoing material, it is determined whether there is paper stuck inside the folding machine, thereby realizing safe and stable operation of the folding machine and ensuring the qualified rate of paper folding. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a principle diagram of origami provided by the present invention;

[0023] Figure 2 is a flow chart of a paper jam detection method for a paper folding machine according to Embodiment 1 of the present invention;

[0024] Figure 3 is a flow chart of a paper jam detection method for a paper folding machine according to a second embodiment of the present invention;

[0025] Figure 4 It is a control system connection diagram provided by the present invention.

[0026] Figure numerals: 1. paper, 2. roller, 3. limiter. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0029] Embodiment 1:

[0030] Figure 1 , 2 4 shows a paper jam detection method for a paper folding machine, wherein sensors for detecting paper are provided at the feeding end and the discharging end of the paper folding machine, and the detection method comprises the following steps:

[0031] S1. Calculate the feeding time T1 and discharging time T2 of the paper according to the running speed of the paper folding machine and the length of the paper before and after folding; when the paper folding machine is running, the feeding time t1 and discharging time t2 actually sensed by the sensor, if the difference between the actual time and the calculated time is within the set range, it is judged that the paper has been fed or discharged, otherwise it is judged as an interference item;

[0032] S2. Determine whether there is a paper jam based on the time interval between feeding and discharging.

[0033] In actual application, there will be some interference factors that will affect the detection of the sensor. For example, when someone passes by, the sensor may respond and think that there is paper in and out, which can easily cause a false alarm of a paper jam alarm. In the present invention, the paper feeding time and discharging time are first calculated, and then the feeding time and discharging time actually sensed by the sensor are compared with the calculated time. If the time difference is within the allowed range, it is determined that the signal sensed by the sensor is paper, otherwise it is determined to be an interference signal, thereby ensuring that the sensor detects paper rather than other interference items. When it is determined that the signal at the feeding end is paper, the controller starts timing. When the paper is output from the output end of the paper folding machine after folding, the controller stops timing when it is determined that the signal at the discharging end is paper. If the time difference between feeding and discharging is within the set range, it is determined to be normal operation. If the sensor at the discharging end has not sensed the paper discharging information for more than the set time, it is determined to be a paper jam.

[0034] The present invention utilizes two photoelectric sensors as paper incoming and outgoing material detection. The PLC calculates the production speed of the folding machine to match the scanning time of the photoelectric sensors. By detecting the feeding and outgoing material, it is determined whether there is paper stuck inside the folding machine. The present invention realizes accurate judgment of paper jam failure of the folding machine, ensures the safety and stability of the folding machine in the production process, prolongs the service life of the folding machine, improves the economic benefits of the product, reduces the failure time of the folding machine, and reduces the production cost.

[0035] The paper jam detection method needs to match different production speeds. Usually, the speed of the folding machine is 200-400 sheets / minute, so the scanning time of the photoelectric detection sensor for feeding and discharging needs to match the production speed of the folding machine, otherwise it will cause false alarms or missed alarms. In the present invention, the scanning time of the photoelectric sensors for feeding and discharging can be controlled according to the production speed of the folding machine. If no paper is detected during the respective scanning time, an alarm signal is generated to stop the folding machine. The present invention is adapted to various production speeds of the folding machine, eliminating the malfunction of the photoelectric sensor caused by the fixed scanning time, and ensuring the production safety and production quality of the folding machine.

[0036] In the present invention, the photoelectric sensor at the feed end is used to detect whether there is paper entering the folder, and the photoelectric sensor at the discharge end is used to detect whether there is paper being delivered to the downstream equipment.

[0037] The PLC program uses the corresponding algorithm to calculate the scanning time of the photoelectric sensors for feeding and discharging and the time required to fold a piece of paper based on the production speed, the length of the paper before and after folding, and the folding method. During the folding process of a piece of paper, if the photoelectric sensor at the feeding end scans the paper within the scanning time, it will wait for the trigger signal from the photoelectric sensor at the discharging end that scans the paper. If the waiting time exceeds the calculated folding time, it is judged that the folding machine is jammed and the folding machine is stopped.

[0038] In this embodiment, in step S1, the calculation of the feeding time T1 and the discharging time T2 in the algorithm is: the feeding time T1 is equal to the length of the paper before folding divided by the running speed; the discharging time T2 is equal to the length of the paper after folding divided by the running speed. Considering the interference of the sensor's own accuracy, the allowable error is Δt, so if the difference between the actual time and the calculated time is less than Δt, it is determined that the paper has been fed or discharged.

[0039] In this embodiment, the sensing time of the sensor at the feeding end in step S1 is the feeding time t1, and the sensing time of the sensor at the discharging end is the discharging time t2. That is, when a material passes through the sensor, the sensor's sensing signal will be triggered, and the duration of the sensing signal at the feeding end is recorded as t1, and the duration of the sensing signal at the discharging end is recorded as t2.

[0040] In this embodiment, when the difference between the feeding time T1 and the feeding time t1 in step S1 is within the set range, it is determined that the material has been fed; when the difference between the discharging time T2 and the discharging time t2 is within the set range, it is determined that the material has been discharged. Theoretically, when T1=t1, it is determined that the material has been fed, and when T2=t2, it is determined that the material has been discharged. Considering the accuracy error of the sensor in the actual working process, the allowable error range Δt is set. Therefore, when the difference between T1 and t1 is within the range of Δt, it is determined that the material has been fed. Similarly, when the difference between T2 and t2 is within the error range, it is determined that the material has been discharged; in this way, the judgment accuracy and anti-interference ability are improved.

[0041] In this embodiment, the time T3 required for folding the paper is calculated according to the running speed of the paper folding machine and the length of the paper to be folded. In the step S2, the folding time t is recorded when the paper has been fed; if the folding time t exceeds the required time T3 and the sensor does not detect the discharge, it is determined that there is a paper jam. Specifically, the timing is started when it is sensed that the feeding end of the paper folding machine has fed the paper, and within the time required for paper folding, the discharge end of the paper folding machine senses the discharge of the paper, and it is determined that the paper folding machine is operating normally; when there is no discharge signal at the discharge end of the paper folding machine after the time required for paper folding, it is determined that there is a paper jam.

[0042] As other embodiments, the paper folding method may be different. When calculating the time required to fold the paper, it is necessary to calculate based on the paper folding method, the running speed of the paper folding machine and the length of the paper.

[0043] In this embodiment, the detection method further includes step S3. When a paper jam is detected, an alarm signal is issued and the paper folding machine is shut down. This solution improves the utilization rate of paper, the qualified rate of paper folding and the production quality of downstream equipment by timely stopping the machine due to a paper jam alarm.

[0044] like Figure 1The figure shows a schematic diagram of paper folding in a paper folding machine. Specifically, the paper 1 enters the paper folding machine from between two rollers 2, and is folded in the paper folding machine through the action of other rollers 2 and a limit member 3. The folded product is output from the discharge end of the paper folding machine.

[0045] Embodiment 2:

[0046] Figure 1 , 3 4 shows a paper jam detection method for a paper folding machine, wherein sensors for detecting paper are provided at the feeding end and the discharging end of the paper folding machine, and the detection method comprises the following steps:

[0047] S1. Calculate the feeding time T1 and discharging time T2 of the paper according to the running speed of the paper folding machine and the length of the paper before and after folding; when the paper folding machine is running, the feeding time t1 and discharging time t2 actually sensed by the sensor, if the difference between the actual time and the calculated time is within the set range, it is judged that the paper has been fed or discharged, otherwise it is judged as an interference item;

[0048] S2. Determine whether there is a paper jam based on the maximum number of folded papers X in the folding machine.

[0049] In actual application, there will be some interference factors that will affect the detection of the sensor. For example, when someone passes by, the sensor may respond and think that there is paper in and out, which can easily cause a false alarm of a paper jam alarm. In the present invention, the paper feeding time and the discharging time are first calculated, and then the feeding time and the discharging time actually sensed by the sensor are compared with the calculated time. If the time difference is within the allowed range, it is determined that the signal sensed by the sensor is paper, otherwise it is determined to be an interference signal, thereby ensuring that the sensor detects paper rather than other interference items. Then, this embodiment determines whether there is a paper jam by the number of sheets of paper in the paper folding machine. Specifically, when it is determined that the signal at the feeding end is paper, the count value is increased by one. When the paper is output from the output end of the paper folding machine after folding in the paper folding machine, when it is determined that the signal at the discharging end is paper, the count value is reduced by one. If the count value is within the set range, it is determined to be normal operation. If the count value is greater than the maximum number of folded paper in the paper folding machine, it is determined to be a paper jam. The paper jam detection method uses the signal of the photoelectric sensor as a counting pulse to accurately calculate the actual number of folds.

[0050] The present invention utilizes two photoelectric sensors as paper incoming and outgoing material detection. The PLC calculates the production speed of the folding machine to match the scanning time of the photoelectric sensors. By detecting the feeding and outgoing material, it is determined whether there is paper stuck inside the folding machine. The present invention realizes accurate judgment of paper jam failure of the folding machine, ensures the safety and stability of the folding machine in the production process, prolongs the service life of the folding machine, improves the economic benefits of the product, reduces the failure time of the folding machine, and reduces the production cost.

[0051] The paper jam detection method needs to match different production speeds. Usually, the speed of the folding machine is 200-400 sheets / minute, so the scanning time of the photoelectric detection sensor for feeding and discharging needs to match the production speed of the folding machine, otherwise it will cause false alarms or missed alarms. In the present invention, the scanning time of the photoelectric sensors for feeding and discharging can be controlled according to the production speed of the folding machine. If no paper is detected during the respective scanning time, an alarm signal is generated to stop the folding machine. The present invention is adapted to various production speeds of the folding machine, eliminating the malfunction of the photoelectric sensor caused by the fixed scanning time, and ensuring the production safety and production quality of the folding machine.

[0052] In the present invention, the photoelectric sensor at the feed end is used to detect whether there is paper entering the folder, and the photoelectric sensor at the discharge end is used to detect whether there is paper being delivered to the downstream equipment.

[0053] In this embodiment, in step S1, the calculation of the feeding time T1 and the discharging time T2 in the algorithm is: the feeding time T1 is equal to the length of the paper before folding divided by the running speed; the discharging time T2 is equal to the length of the paper after folding divided by the running speed. Considering the interference of the sensor's own accuracy, the allowable error is Δt, so if the difference between the actual time and the calculated time is less than Δt, it is determined that the paper has been fed or discharged.

[0054] In this embodiment, the sensing time of the sensor at the feeding end in step S1 is the feeding time t1, and the sensing time of the sensor at the discharging end is the discharging time t2. That is, when a material passes through the sensor, the sensor's sensing signal will be triggered, and the duration of the sensing signal at the feeding end is recorded as t1, and the duration of the sensing signal at the discharging end is recorded as t2.

[0055] In this embodiment, when the difference between the feeding time T1 and the feeding time t1 in step S1 is within the set range, it is determined that the material has been fed; when the difference between the discharging time T2 and the discharging time t2 is within the set range, it is determined that the material has been discharged. Theoretically, when T1=t1, it is determined that the material has been fed, and when T2=t2, it is determined that the material has been discharged. Considering the accuracy error of the sensor in the actual working process, the allowable error range Δt is set. Therefore, when the difference between T1 and t1 is within the range of Δt, it is determined that the material has been fed. Similarly, when the difference between T2 and t2 is within the error range, it is determined that the material has been discharged; in this way, the judgment accuracy and anti-interference ability are improved.

[0056] In this embodiment, in step S2, if the difference between the number of sheets of paper fed and the number of sheets of paper discharged is greater than the maximum set value of the number of sheets of paper folded in the paper folding machine, it is determined that there is a paper jam. Specifically, when the feed end and the discharge end of the paper folding machine sense a signal that the paper has been fed or discharged, the digital input module connected to the controller starts counting, the digital input module input is incremented when the paper has been fed, and the digital input module input is decremented when the paper has been discharged, and the PLC controller connected to the digital input module obtains the number of sheets of paper in the paper folding machine based on the digital information, and when the number of sheets of paper is greater than the set maximum number of sheets of paper folded in the paper folding machine X, it is determined that there is a paper jam.

[0057] In this embodiment, in step S2, the sensor signal is recorded in the form of counting pulses, and when the difference between the number of infeed signals and the number of outfeed signals is greater than the maximum setting value X for folding paper in the paper folding machine, it is determined to be a paper jam.

[0058] In this embodiment, the sensor at the feed end of the paper folding machine is a feed photoelectric sensor, and the sensor at the discharge end is a discharge photoelectric sensor. Both the feed photoelectric sensor and the discharge photoelectric sensor are connected to the digital input module, and the digital input module is connected to the PLC controller. The servo motor used to drive the paper folding machine is connected to the PLC controller through a servo driver.

[0059] In this embodiment, the detection method further includes step S3. When a paper jam is detected, an alarm signal is issued and the paper folding machine is shut down. This solution improves the utilization rate of paper, the qualified rate of paper folding and the production quality of downstream equipment by timely stopping the machine due to a paper jam alarm.

[0060] like Figure 1 The figure shows a schematic diagram of paper folding in a paper folding machine. Specifically, the paper 1 enters the paper folding machine from between two rollers 2, and is folded in the paper folding machine through the action of other rollers 2 and a limit member 3. The folded product is output from the discharge end of the paper folding machine.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A paper jam detection method for a paper folding machine, wherein sensors for detecting paper are provided at the feeding end and the discharging end of the paper folding machine, characterized in that: The detection method comprises the following steps: S1. Calculate the feeding time T1 and discharging time T2 of the paper according to the running speed of the paper folding machine and the length of the paper before and after folding; when the paper folding machine is running, the feeding time t1 and discharging time t2 actually sensed by the sensor, if the difference between the actual time and the calculated time is within the set range, it is judged that the paper has been fed or discharged, otherwise it is judged as an interference item; S2. Determine whether there is a paper jam based on the time interval between feeding and discharging or by calculating the maximum number of folded papers X in the folding machine.

2. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: In the step S1, the feeding time T1 = the length of the paper before folding / the running speed; the discharging time T2 = the length of the paper after folding / the running speed.

3. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: In the step S1, the sensing time of the sensor at the feeding end is the feeding time t1, and the sensing time of the sensor at the discharging end is the discharging time t2.

4. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: In step S1, when the difference between the feeding time T1 and the feeding time t1 is within the set range, it is determined that the material has been fed; when the difference between the discharging time T2 and the discharging time t2 is within the set range, it is determined that the material has been discharged.

5. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: According to the running speed of the paper folding machine and the length of the paper to be folded, the time T3 required for folding the paper is calculated. In the step S2, the folding time t is recorded when the paper has been fed; if the folding time t exceeds the required time T3 and the sensor does not detect the discharge, it is judged as a paper jam.

6. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: In the step S2, if the difference between the number of sheets fed in and the number of sheets discharged is greater than the maximum set value of the number of sheets folded in the paper folding machine, it is determined to be a paper jam.

7. A paper jam detection method for a paper folding machine according to claim 6, characterized in that: In step S2, the sensor signal is recorded in the form of counting pulses. When the difference between the number of feeding signals and the number of discharging signals is greater than the maximum setting value of the controller, it is determined to be a paper jam.

8. A paper jam detection method for a paper folding machine according to claim 1, characterized in that: The detection method further comprises step S3. When it is determined that there is a paper jam, an alarm signal is issued and the paper folding machine is shut down.

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