A knotting control method for a bundling machine

Abstract

The present invention discloses a knotting control method for a bundling machine. The bundling machine includes a circle forming mechanism, a wire twisting mechanism, a driving wire feeding wheel, a trigger, and a motor for driving the rotation of the wire twisting mechanism. It is characterized in that the method includes: according to a first input signal generated by a user pressing the trigger, controlling the driving wire feeding wheel to feed the bundling wire to the circle forming mechanism at a preset feeding amount; controlling the wire twisting mechanism to twist the bundling wire at a preset first speed at high speed, and monitoring the output torque of the motor during the wire twisting process; when the output torque reaches a set value, controlling the wire twisting mechanism to twist the wire at a preset second speed in the same direction at a low speed for a preset number of turns. The present invention can further tighten the bundling wire while reducing the breakage of the bundling wire, improve the bundling tightness of the bundling wire, improve the utilization efficiency of the bundling wire by the bundling machine, and further improve the bundling efficiency of the bundling machine.

Description

Technical Field

[0001] The present invention relates to the technical field of strapping machines, and in particular to a knotting control method for a strapping machine. Background Art

[0002] A strapping machine is a device used to wind and fix an object by bending a strapping wire and tighten it. As described in patent CN111706084A, the strapping machine includes a bending forming part (i.e., a circle forming mechanism), a twisting unit (i.e., a wire twisting mechanism), a feeding unit (i.e., a wire feeding wheel, including a driving wire feeding wheel and a driven wire feeding wheel), a strapping trigger (i.e., a trigger), etc. Among them, when the strapping wire winds and fixes the object, the strapping machine twists and knots the two ends of the strapping wire to tighten the object.

[0003] In actual use, the strapping machine generally knots the strapping wire by setting knotting parameters based on manual experience. However, when the knotting parameters are set too loose, the knotting result may not be tight enough, and it may be necessary to re-strap and tighten, resulting in waste. Moreover, multiple attempts may be required to ensure tightening without breaking the strapping wire. When the knotting parameters are set too tight, the strapping wire may be broken during knotting, which is very dangerous and also requires re-strapping, resulting in waste.

[0004] Therefore, how to achieve precise knotting of the strapping machine is very important. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a knotting control method for a strapping machine, which can further tighten the strapping wire while reducing the breakage of the strapping wire, improve the tightening degree of the strapping wire, improve the utilization efficiency of the strapping wire by the strapping machine, and thus improve the strapping efficiency of the strapping machine.

[0006] To solve the above technical problem, a first aspect of the present invention discloses a knotting control method for a strapping machine, the strapping machine includes a circle forming mechanism, a wire twisting mechanism, a driving wire feeding wheel, a trigger, and a motor for driving the wire twisting mechanism to rotate; characterized in that the method includes:

[0007] According to a first input signal generated by a user pressing the trigger, controlling the driving wire feeding wheel to convey the strapping wire to the circle forming mechanism at a preset feeding amount;

[0008] Controlling the wire twisting mechanism to twist the strapping wire at a preset first speed at high speed, and monitoring the output torque of the motor during the wire twisting process;

[0009] When the output torque reaches a set value, controlling the wire twisting mechanism to twist the wire at a preset second speed in the same direction at a low speed for a preset number of turns.

[0010] As an alternative embodiment, in the first aspect of the present invention, monitoring the output torque of the motor during the wire twisting process further includes:

[0011] Monitoring the current of the motor during the wire twisting process, and calculating the output torque according to the current of the motor.

[0012] As an alternative embodiment, in the first aspect of the present invention, the manner of monitoring that the output torque reaches the set value further includes:

[0013] Taking the current of the motor during the wire twisting process being greater than or equal to the initial upper limit current as a trigger signal to determine that the output torque of the motor reaches the set value; or,

[0014] Taking the starting point of the decline when the current value of the motor during the wire twisting process starts to decline after continuous increase as a trigger signal to determine that the output torque of the motor reaches the set value.

[0015] As an alternative embodiment, in the first aspect of the present invention, after monitoring the output torque of the motor during the wire twisting process, the method further includes:

[0016] At the starting point of the decline when the current value of the motor starts to decline after continuous increase, obtaining the current value of the motor as the first current;

[0017] Determining the first current as the current upper limit current to update the initial upper limit current; or,

[0018] Multiplying the first current by a first weight to obtain a first result, multiplying the initial upper limit current by a second weight to obtain a second result, and using the sum of the first result and the second result as the current upper limit current to update the initial upper limit current.

[0019] As an alternative embodiment, in the first aspect of the present invention, the first speed is configured as the maximum wire twisting speed allowed by the bundling machine.

[0020] As an alternative embodiment, in the first aspect of the present invention, the second speed is configured as 20 - 40% of the first speed, and / or

[0021] The preset number of turns is configured as 2 - 10 turns.

[0022] As an alternative embodiment, in the first aspect of the present invention, before monitoring the output torque of the motor during the wire twisting process, the method further includes:

[0023] Monitor the current of the motor of the strapping machine in real time during multiple knotting operations. During each knotting process, when it is detected that the current value starts to decrease after continuously increasing, obtain the current value of the motor at the starting point of the decrease when the decrease starts.

[0024] Determine the average value of the current values of the motor obtained during all the knotting processes as the initial upper limit current, or determine the lowest value among the current values of the motor obtained during all the knotting processes as the initial upper limit current.

[0025] A second aspect of the present invention discloses a computer storage medium, characterized in that the computer storage medium stores computer instructions, which are used to execute the steps in the above-mentioned knotting control method when called.

[0026] A third aspect of the present invention discloses a strapping machine, characterized in that it is used to execute the steps in the above-mentioned knotting control method.

[0027] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0028] Compared with the prior art, in the embodiments of the present invention, after the strain of the strapping wire reaches the set value, the wire twisting continues in the state of being lower than the original speed. Compared with the solution of not continuing to twist the wire, it can be twisted tighter. Compared with the solution of continuing to twist the wire at the original speed, it is less likely to break during the same wire twisting time. Therefore, the embodiments of the present invention can further tighten the strapping wire while reducing the breakage of the strapping wire, improve the tightening degree of the strapping wire, improve the utilization efficiency of the strapping wire by the strapping machine, and further improve the strapping efficiency of the strapping machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 is a schematic flow chart of a knotting control method for a strapping machine disclosed in an embodiment of the present invention;

[0031] Figure 2 is a schematic diagram showing the relationship between the tangential stress and strain of the strapping wire during the wire twisting process disclosed in an embodiment of the present invention;

[0032] Figure 3 is a schematic diagram showing the relationship between the output torque of the motor of the strapping machine and time during the wire twisting process disclosed in an embodiment of the present invention;

[0033] Figure 4It is a schematic flow chart of another knotting control method of the strapping machine disclosed in the embodiments of the present invention. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Embodiment 1

[0036] See Figure 1 , Figure 1 , which is a schematic flow chart of a knotting control method of a strapping machine disclosed in the embodiments of the present invention. The strapping machine includes a circle forming mechanism, a wire twisting mechanism, a driving wire feeding wheel, a trigger, and a motor for driving the wire twisting mechanism to rotate; the method includes:

[0037] 101. According to the first input signal generated by the user pressing the trigger, control the driving wire feeding wheel to feed the strapping wire to the circle forming mechanism at a preset feeding amount.

[0038] 102. Control the wire twisting mechanism to twist the strapping wire at a preset first speed at high speed, and monitor the output torque of the motor during the wire twisting process.

[0039] 103. When the output torque reaches the set value, control the wire twisting mechanism to twist the wire at a preset second speed in the same direction at a low speed for a preset number of turns.

[0040] In this embodiment, the set value of the output torque is less than or equal to the peak value of the output torque; wherein, the peak value of the output torque can be obtained according to the relationship between the output torque and time when the strapping machine twists the wire.

[0041] For common strapping wires, such as those made of steel, when being twisted, shear stress is generated on the cross-section of the material by the torque action. When the tangential stress exceeds the shear strength of the material, the material will break. As Figure 2 shown is a schematic diagram of the relationship between the tangential stress and strain of the strapping wire during the wire twisting process. As the wire twisting process progresses, the strain of the strapping wire gradually increases, and the tangential stress on the ab section of the strapping wire increases with the increase of the strain (elastic deformation stage). Figure 3 is Figure 2 a schematic diagram of the relationship between the output torque of the motor of the strapping machine and time during the wire twisting process, and the ab section corresponds to Figure 3In the AB segment, at this time, the load of the binding machine motor is increasing, and the output torque of the motor is also increasing accordingly. The torque corresponding to time B is the peak value of the output torque. In the bd segment, the tangential stress decreases with the increase of the strain (plastic deformation stage) until the binding wire is broken when the strain reaches dmm. Among them, the bd segment corresponds to Figure 3 the BD segment shown in Figure 2 . In this stage, the load of the motor begins to decrease, and the output torque of the motor becomes smaller and smaller until the binding wire is broken at moment D (corresponding to

[0042] the moment when the strain in Figure 2 reaches dmm). Figure 2 For example, as shown in

[0043] , in the prior art, after the strain of the binding wire reaches b mm, the wire twisting stops or continues to twist at the original speed. Compared with the prior art, in the embodiment of the present invention, after the strain of the binding wire reaches the set value (b mm or a certain value before b mm), the wire is twisted continuously at a speed lower than the original speed. Compared with the scheme of not continuing to twist the wire, it can be tightened more tightly. Compared with the scheme of continuing to twist the wire at the original speed, it is less likely to break within the same wire twisting time (if the final strain of the binding wire in the embodiment of the present invention is c mm as shown in Figure 4 , Figure 4 then, within the same wire twisting time, the final strain of the scheme of continuing to twist the wire at the original speed will be greater than c mm, closer to or even equal to the strain d mm corresponding to the break). Therefore, the embodiment of the present invention can further tighten the binding wire while reducing the breakage of the binding wire, improve the tightening degree of the binding wire, improve the utilization efficiency of the binding wire by the binding machine, and further improve the binding efficiency of the binding machine.

[0044] 201. According to the first input signal generated by the user pressing the trigger, control the active wire feeding wheel to feed the binding wire to the wire forming mechanism at a preset feed rate.

[0045] 202. Control the wire twisting mechanism to twist the binding wire at a preset first speed at high speed, monitor the current of the motor during the wire twisting process, and calculate the output torque according to the current of the motor.

[0046] 203. When the output torque reaches the set value, control the wire twisting mechanism to twist the wire at a preset second speed in the same direction at a low speed for a preset number of turns.

[0047] In motor knowledge, the motor current is proportional to the output torque. The output torque can be obtained by multiplying the acquired motor current by a relevant coefficient. In this optional embodiment, the output torque is calculated by acquiring the motor current, and the output torque can be monitored through the motor current.

[0048] In yet another alternative embodiment, before monitoring the output torque of the motor during the process of twisting the wire, the method further includes:

[0049] Real-time monitor the current of the motor of the strapping machine during multiple tying operations. During each tying process, when it is detected that the current value of the motor starts to decrease after continuously increasing, obtain the current value of the motor at the starting point of the decrease when the decrease starts;

[0050] Determine the average value of the current values of the motor obtained during all the tying processes as the initial upper limit current, or determine the lowest value among the current values of the motor obtained during all the tying processes as the initial upper limit current.

[0051] Since the motor current is proportional to the output torque, when the current value of the motor starts to decrease after continuously increasing, it can be regarded as entering the BD stage at Figure 3 Among them, the output torque corresponding to point B is the peak output torque. In this alternative embodiment, setting the initial upper limit current as the average value of the motor currents at the peak output torques during multiple tying processes can reduce errors; or setting the initial upper limit current as the lowest value of the motor currents at the peak output torques during multiple tying processes can greatly reduce the possibility of breakage.

[0052] In yet another alternative embodiment, the method for monitoring that the output torque reaches the set value further includes:

[0053] Taking the current of the motor during the wire twisting process being greater than or equal to the initial upper limit current as a trigger signal to determine that the output torque of the motor reaches the set value.

[0054] In yet another alternative embodiment, the method for monitoring that the output torque reaches the set value may further include:

[0055] Taking the starting point of the decrease when the current value of the motor during the wire twisting process starts to decrease after continuously increasing as a trigger signal to determine that the output torque of the motor reaches the set value.

[0056] In this alternative embodiment, since the motor current is proportional to the output torque, when the current value of the motor starts to decrease after continuously increasing, it can be regarded as entering the BD stage at Figure 3 Among them, the starting point of the decrease when it starts to decrease, that is, the output torque corresponding to point B, is the peak output torque.

[0057] In yet another alternative embodiment, after monitoring the output torque of the motor during the process of twisting the wire, the method further includes:

[0058] At the starting point of the decrease when the current value of the motor starts to decrease after continuously increasing, obtain the current value of the motor as the first current;

[0059] Update the initial upper limit current by determining the first current as the current upper limit current; or,

[0060] Multiply the first current by a first weight to obtain a first result, multiply the initial upper limit current by a second weight to obtain a second result, and use the sum of the first result and the second result as the current upper limit current to update the initial upper limit current.

[0061] In this alternative embodiment, after determining the initial upper limit current, during actual use, if the material changes slightly due to some reasons (such as long-term placement, environmental changes, etc.), the initial upper limit current can also be adaptively updated. By monitoring the starting drop point and updating the initial upper limit current according to the current corresponding to the latest starting drop point, it is possible to adapt to the current situation by referring to the latest torsion wire data, improving the adaptability of the torsion wire of the bundling machine.

[0062] In yet another alternative embodiment, the first speed is configured as the maximum torsion wire speed allowed by the bundling machine.

[0063] In yet another alternative embodiment, the second speed is configured as 20-40% of the first speed, and / or the preset number of turns is configured as 2-10 turns.

[0064] In this alternative embodiment, the time used to torsion wire the maximum number of turns in the preset number of turns at the maximum speed of the second speed is less than Figure 3 the time corresponding to the BD segment in, which can reduce the situation of bundling wire breakage on the basis of further tightening the bundled object.

[0065] Embodiment 2

[0066] A computer storage medium, characterized in that the computer storage medium stores computer instructions, and when the computer instructions are called, they are used to execute the steps in the knotting control method described in Embodiment 1.

[0067] Embodiment 3

[0068] A bundling machine for executing the steps in the knotting control method described in Embodiment 1.

[0069] What is disclosed in the content of the embodiments of the present invention is only the preferred embodiments of the present invention, and is only used to illustrate the technical solutions of the present invention, rather than limiting it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that; they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A knotting control method for a bundling machine, the bundling machine comprising a circular forming mechanism, a wire twisting mechanism, a driving wire feeding wheel, a trigger, and a motor for driving the wire twisting mechanism to rotate; characterized in that, The method includes: According to a first input signal generated by a user pressing the trigger, controlling the active wire feeding wheel to feed the binding wire to the wire forming mechanism at a preset feeding amount; Controlling the wire twisting mechanism to twist the binding wire at a preset first speed at high speed, and monitoring the output torque of the motor during the wire twisting process; When the output torque reaches a set value, controlling the wire twisting mechanism to twist the wire at a preset second speed in the same direction at a low speed for a preset number of turns.

2. The knotting control method according to claim 1, wherein The monitoring of the output torque of the motor during the wire twisting process further includes: Monitoring the current of the motor during the wire twisting process, and calculating the output torque according to the current of the motor.

3. The knotting control method according to claim 2, characterized in that The method for monitoring the manner in which the output torque reaches the set value further includes: Using the current of the motor during the wire twisting process being greater than or equal to the initial upper limit current as a trigger signal to determine that the output torque of the motor reaches the set value; or Using the starting point of the decline when the current value of the motor during the wire twisting process starts to decline after continuously rising as a trigger signal to determine that the output torque of the motor reaches the set value.

4. The knotting control method according to claim 3, wherein, After the monitoring of the output torque of the motor during the wire twisting process, the method further includes: At the starting point of the decline when the current value of the motor starts to decline after continuously rising, obtaining the current value of the motor as the first current; Determining the first current as the current upper limit current to update the initial upper limit current; or Multiplying the first current by a first weight to obtain a first result, multiplying the initial upper limit current by a second weight to obtain a second result, and using the sum of the first result and the second result as the current upper limit current to update the initial upper limit current.

5. The knotting control method according to claim 1, characterized in that The first speed is configured as the maximum wire twisting speed allowed by the bundling machine.

6. The knotting control method according to claim 1 or 4, wherein The second speed is configured as 20 - 40% of the first speed and / or The preset number of turns is configured as 2 - 10 turns.

7. The knotting control method according to claim 3 or 4, characterized in that Before the monitoring of the output torque of the motor during the wire twisting process, the method further includes: Real - time monitoring of the current of the motor when the bundling machine makes multiple knots. During each knotting process, when it is detected that the current value of the motor starts to decline after continuously rising, obtaining the current value of the motor at the starting point of the decline; Determining the average value of the current values of the motor obtained during all the knotting processes as the initial upper limit current, or determining the lowest value of the current values of the motor obtained during all the knotting processes as the initial upper limit current.

8. A computer storage medium, characterized in that, The computer storage medium stores computer instructions, which when called, are used to execute the steps in the knotting control method according to any one of claims 1 - 7.

9. A strapping machine, characterized in that, For executing the steps in the knotting control method according to any one of claims 1 - 7.

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