I. Introduction
AC servo drives are more and more widely used in industrial applications because of their advantages of high precision, high speed, and high efficiency. The PSDD series AC servo drives produced by Shenzhen Research Automation Technology Co., Ltd. are widely used in numerical control machine tools, spring machines, drilling machines, packaging machines, knitting machines and other automation equipment with high cost performance. At present, the research and control servo is successfully applied to battery packaging machinery.
This application is required by a Packaging Machinery Co., Ltd. to perform performance upgrades on older models. The device originally used a stepping drive system, because the step-by-step motor's torque-frequency characteristic is a falling curve, resulting in the fastest stepping motor can only run at 600r/min, packaging 270 No. 7 batteries per minute. The customer's needs are to pack more than 400 products per minute by upgrading the drives and motors to the servo system without changing the mechanical structure.
Second, the standard speed calculation
When 270 tags are output per minute, the motor speed is 600r/min. When the labeling speed reaches 400/min, it is increased by 48%. In the case of keeping all the mechanical structures unchanged, the speed of the motor responsible for issuing the mark also needs to be increased by 48%. Let the speed of the motor after the upgrade be R, then R=600×(1+0.48)
Third, the calculation of electronic gear ratio
Since the PLC program is fixed and cannot be modified, the frequency of the pulse command issued by the PLC is also fixed. Changing the motor speed without changing the pulse command frequency can change the number of subdivisions for the stepping system. Accordingly, for the AC servo system, the electronic gear ratio can be changed. Suppose the pulse command frequency sent by the PLC is H, the speed of the motor is R, and the electronic gear ratio is G. Then
H=R/(6×G)
In the case where the electronic gear ratio G=1, the rotational speed corresponding to the pulse command frequency of 1 Hz is 6 r/min. R/6 is the value that the pulse command frequency should reach when the electronic gear ratio is 1. After this value is divided by the electronic gear ratio, it is the actually received pulse command frequency. Since H is known, so
G=R/(6×H)
Fourth, the track speed calculation
Simply increasing the speed of the bid does not achieve the goal of increasing production capacity. Because mechanical equipment is a system, simply increasing the performance of some structures will cause short board effects. The short board here is the line crawler speed. If the track speed of the assembly line is not increased, the increase in the speed of the marking is meaningless. Since the next workpiece has not arrived after the bid is exited, the bid-out structure can only be in a waiting state, and the production efficiency is limited by the speed of the bare-bone crawler conveyor.
Let the linear velocity of the track be V, the rotation speed of the track drive motor be R, the diameter of the gear connected to the motor be L, the speed of the labelling is N/min, the length of the label is a, and the spacing between the two labels is b, then,
V=(a+b)×N
V=π×L×R
By combining the above two formulas,
R=(a+b)×N/(π×L)
The above calculations are based on a theoretical perspective. In actual debugging, the cooperation between the biding speed and track speed still requires fine-tuning by experienced workers. When the export speed is higher than the crawler speed, normal production is possible. However, the bid-out part needs to wait for the workpiece and cannot maximize the production efficiency. It violates the original intention of upgrading the equipment; when the speed of the bid is lower than the crawler speed, the previous workpiece Not yet wrapped, the next part has arrived, the battery is tagged into a chain, and the factory dubbed it the "bullet".
Fifth, the motor selection
At present, the research and control company has servo drive systems from 400 to 1500W to choose from, each power level has a variety of motors to choose from, to adapt to different speed, torque and load inertia occasions. In this application, the YK80ST-M03520 750w servo motor was selected for the customer, which satisfies the application requirements. This can also be seen in later parameter adjustments. The parameter adjustment of the servo system has always been a troublesome problem in the servo application, but for different application occasions, through careful selection work, the necessity of parameter adjustment can be greatly reduced. In this application, only the electronic gear ratio was changed, and other parameters were kept at default values, which had already met the application requirements well.
VI. Conclusion
The customer is very satisfied with the increase in production capacity brought by this upgrade. In fact, during the commissioning process, the packaging section was upgraded to easily break through 600 workpieces/min. However, due to the bottleneck of the previous stage of the assembly line, it can only run at 400 workpieces/min. With the servo system, the increase in production capacity is significant, but the increase in costs is negligible compared to the entire production line. More and more equipment manufacturers recognize the advantages of servo systems, and the application of servo systems has become increasingly popular.
AC servo drives are more and more widely used in industrial applications because of their advantages of high precision, high speed, and high efficiency. The PSDD series AC servo drives produced by Shenzhen Research Automation Technology Co., Ltd. are widely used in numerical control machine tools, spring machines, drilling machines, packaging machines, knitting machines and other automation equipment with high cost performance. At present, the research and control servo is successfully applied to battery packaging machinery.
This application is required by a Packaging Machinery Co., Ltd. to perform performance upgrades on older models. The device originally used a stepping drive system, because the step-by-step motor's torque-frequency characteristic is a falling curve, resulting in the fastest stepping motor can only run at 600r/min, packaging 270 No. 7 batteries per minute. The customer's needs are to pack more than 400 products per minute by upgrading the drives and motors to the servo system without changing the mechanical structure.
Second, the standard speed calculation
When 270 tags are output per minute, the motor speed is 600r/min. When the labeling speed reaches 400/min, it is increased by 48%. In the case of keeping all the mechanical structures unchanged, the speed of the motor responsible for issuing the mark also needs to be increased by 48%. Let the speed of the motor after the upgrade be R, then R=600×(1+0.48)
Third, the calculation of electronic gear ratio
Since the PLC program is fixed and cannot be modified, the frequency of the pulse command issued by the PLC is also fixed. Changing the motor speed without changing the pulse command frequency can change the number of subdivisions for the stepping system. Accordingly, for the AC servo system, the electronic gear ratio can be changed. Suppose the pulse command frequency sent by the PLC is H, the speed of the motor is R, and the electronic gear ratio is G. Then
H=R/(6×G)
In the case where the electronic gear ratio G=1, the rotational speed corresponding to the pulse command frequency of 1 Hz is 6 r/min. R/6 is the value that the pulse command frequency should reach when the electronic gear ratio is 1. After this value is divided by the electronic gear ratio, it is the actually received pulse command frequency. Since H is known, so
G=R/(6×H)
Fourth, the track speed calculation
Simply increasing the speed of the bid does not achieve the goal of increasing production capacity. Because mechanical equipment is a system, simply increasing the performance of some structures will cause short board effects. The short board here is the line crawler speed. If the track speed of the assembly line is not increased, the increase in the speed of the marking is meaningless. Since the next workpiece has not arrived after the bid is exited, the bid-out structure can only be in a waiting state, and the production efficiency is limited by the speed of the bare-bone crawler conveyor.
Let the linear velocity of the track be V, the rotation speed of the track drive motor be R, the diameter of the gear connected to the motor be L, the speed of the labelling is N/min, the length of the label is a, and the spacing between the two labels is b, then,
V=(a+b)×N
V=π×L×R
By combining the above two formulas,
R=(a+b)×N/(π×L)
The above calculations are based on a theoretical perspective. In actual debugging, the cooperation between the biding speed and track speed still requires fine-tuning by experienced workers. When the export speed is higher than the crawler speed, normal production is possible. However, the bid-out part needs to wait for the workpiece and cannot maximize the production efficiency. It violates the original intention of upgrading the equipment; when the speed of the bid is lower than the crawler speed, the previous workpiece Not yet wrapped, the next part has arrived, the battery is tagged into a chain, and the factory dubbed it the "bullet".
Fifth, the motor selection
At present, the research and control company has servo drive systems from 400 to 1500W to choose from, each power level has a variety of motors to choose from, to adapt to different speed, torque and load inertia occasions. In this application, the YK80ST-M03520 750w servo motor was selected for the customer, which satisfies the application requirements. This can also be seen in later parameter adjustments. The parameter adjustment of the servo system has always been a troublesome problem in the servo application, but for different application occasions, through careful selection work, the necessity of parameter adjustment can be greatly reduced. In this application, only the electronic gear ratio was changed, and other parameters were kept at default values, which had already met the application requirements well.
VI. Conclusion
The customer is very satisfied with the increase in production capacity brought by this upgrade. In fact, during the commissioning process, the packaging section was upgraded to easily break through 600 workpieces/min. However, due to the bottleneck of the previous stage of the assembly line, it can only run at 400 workpieces/min. With the servo system, the increase in production capacity is significant, but the increase in costs is negligible compared to the entire production line. More and more equipment manufacturers recognize the advantages of servo systems, and the application of servo systems has become increasingly popular.