JPS5827078B2 - How to eliminate torque fluctuations in web cutters - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for eliminating torque fluctuations in a web cutter, and particularly to a method for cutting a web that is continuously being transported in one direction to a desired length without stopping the web. The present invention relates to a method for eliminating steady torque fluctuations of a web cutter.

The web referred to in the present invention usually has a thickness of 5 μ to 5 nm,
A flexible and relatively long strip with a width of 10 cm to 3 doors, such as polyvinyl chloride, polycarbonate, acrylonitrile styrene copolymer, ABS resin, polyester, glass fiber-containing polyester resin, cellulose derivative, It consists of plastic films such as, sheets of paper, synthetic paper, etc., and thin metal sheets of aluminum, copper, etc.

In the manufacturing process, the web is generally wound into a roll and then cut into a desired length depending on the intended use while being rewound at various stages of processing. In order to perform processing efficiently, the following types of cutting devices have been widely used.

One is a rotary cutter consisting of a pair of rotating blades arranged vertically to sandwich the web. The web is cut to a desired length by the meshing of the two.

Another type of cutter is called a self-propelled cutter, and has a movable blade that can move up and down upwards so as to sandwich the web, and a receiving blade below, and the movable blade and receiving blade are arranged parallel to the web. The movable blade is lowered toward the receiving blade while simultaneously moving the web to cut the web to a desired length.

Since the main purpose of both methods is to cut the web to a desired length without stopping the running of the web, it was expected that the cutting process by both methods would be extremely efficient.

However, periodic and steady torque fluctuations occur on the drive shaft of the cutting blade in both cases due to shear torque, viscous torque, or mechanisms such as cams or links, and this torque fluctuation causes the speed of the cutting blade to change. As a result, the cutting accuracy of the web was significantly reduced.

In particular, as shown in FIG. At the same time, the speed or position of the pair of cutting blades 2, 2 of the web cutter is detected by another pulse generator 12, and each output signal of both pulse generators 4, 12 and the cutting length setting of the cutting length setting device 6 are detected. The signal is input to the digital regulator 5 to obtain an analog voltage speed command signal, and the speed command signal is input to the analog regulator 7 to which the detection signal of the tacho generator 9 that detects the speed of the motor 10 is fed back. detects the speed difference between the cutting blades 2, 2 with respect to the web 1, and in accordance with the speed difference, the power stack 8 sends a speed control signal to the motor 10 that drives the cutting blades 2, 2 via a transmission mechanism 11. Since the cutting blades 2, 2 are configured and operated so as to output an output, the speed fluctuations of the cutting blades 2, 2 accompanying the constantly occurring torque fluctuations are accompanied by a certain delay even with the closed loop drive control system described above. Speed control was required, and delays in this control tended to become more noticeable as the number of cuts per unit time increased.

On the other hand, if the response of the control system is improved by increasing the loop gain as a measure against the delay described above, there are disadvantages such as the control system tends to become unstable and the equipment becomes expensive. Ta.

The present invention eliminates the drawbacks of the conventional web cutter drive control system described above, effectively eliminates steady torque fluctuations that occur during the operation of the web cutter in a relatively simple manner,
It is an object of the present invention to provide a method for eliminating torque fluctuations in a web cutter that can significantly improve the cutting accuracy of the web.

An object of the present invention is to provide a method for eliminating steady torque fluctuations of a web cutter that cuts a web to a desired length without stopping the web that is continuously being transported in one direction. The torque compensation signal is input into an analog regulator in an open loop according to the position detection signal of the cutting blade from a torque memory storing a torque compensation signal in advance corresponding to the position of the cutting blade of the web cutter, and the cutting This is achieved by a method for eliminating torque fluctuations in a web cutter, which is characterized by generating and controlling the power of the motor for driving one of the blades so that the above-mentioned steady torque fluctuations can be eliminated.

Hereinafter, one embodiment of the method of the present invention will be described in detail based on the attached drawings.

FIG. 2 shows an embodiment in which the method of the present invention is applied to a rotary type web cutter.

The drive control system used in the web cutter has substantially the same configuration and effects as the conventional drive control system described above, except for the torque memory 13.

First, the position of the web 1 that is being continuously transported in one direction A is detected via a pulse generator 4 that is pivotally attached to a length measuring roll 3, while a pair of cutting blades 2, 2 of a web cutter are detected.
is detected by another pulse generator 12, and the respective output signals S and C of the pulse generators 4 and 12 and the cutting length setting signal a of the cutting length setting device 6 are inputted to the digital regulator 5, and the analog voltage is A speed command signal d is obtained, and the speed command signal d is inputted to an analog regulator 7 to which a detection signal f from a tachogenerator 9 that detects the speed of the DC motor 10 is fed back. A speed difference with respect to the web 1 is detected, a thyristor gate signal g is applied to the power stack 8 according to the speed difference, and the ignition pulse angle of the power stack 10 is controlled by the thyristor gate signal g, and the DC motor 10 The armature current increases or decreases in accordance with the speed difference, and the speed of the DC motor 10, that is, the speed of the cutting blades 2, 2 is controlled so as to match the speed of the web 1.

On the other hand, as shown in detail in FIG.
The cutting blades 2, 2 are located near one of the drive shafts.
Detecting the reference position of the other pulse generator 12
The sensor 14 outputs a signal for correcting the cumulative positional error of the cutting blades 2, 2 due to The digital memo IJDM subdivides the displacement period of the cutting blade 2°2 in proportion to the frequency of the other pulse generator 12, and uses the reference position as the origin,
Torque compensation signals (voltages) are stored in sequence.

The torque compensation signal is used to control the cutting blades 2, 2 so that the DC motor 10 generates an appropriate torque to eliminate steady torque fluctuations that occur with the operation of the cutting blades 2, 2. A digital value of the command voltage is stored corresponding to the position.

When the reference position signal is input to the torque memory 13, the digital memo IJDM reliably returns to the origin,
Eventually, the torque compensation signal is sequentially read out by the output signal C of the other pulse generator 12, and the D/
The torque compensation signal is converted into an analog voltage by the A converter DAC and outputted to the analog regulator 7 as a torque cancellation signal e.

The analog regulator 7 matches the speed command signal d with the output signal f of the tachometer generator 9, and further outputs the thyris gate signal g, which is the sum of the torque cancellation signal e, to the power stack 8.

To explain the action of the analog regulator 7 described above in detail in comparison with the conventional method, the conventional method feeds back the output signal f of the tachogenerator 9 to the speed command signal d, and outputs the thyristor gate signal which is the operating signal. g
= d - f, but on the other hand, the method of the present invention outputs the d - f + e risk gate signal g to which the torque cancellation signal e is added.

The torque cancellation signal e, like the speed command signal d, is not modified by the output signal f of the tacho generator 9 and is input to the analog regulator 7 in an open loop, so that the disconnection that occurs regularly can be avoided. The DC motor 10 is driven with enough power to compensate for the torque fluctuation without being delayed by the torque fluctuation of the blades 2, 2.

On the other hand, since the correction of the speed difference is performed by an operation signal based on a closed loop of the speed command signal d and the output signal f of the tacho generator 9, steady torque fluctuations in the cutting blades 2, 2 are eliminated in a timely manner. While being driven, the web 1 is driven at approximately the same circumferential speed as the web 1.
Even during high-speed cutting, the driving state of the cutting blades 2, 2 described above is maintained.

Note that the output pulses of the other pulse generators 12 may be appropriately thinned out, or other sensors may be placed at desired positions to intensively control only the positions of the cutting blades 2, which require torque compensation. You may do so.

Furthermore, the other pulse generator 12 can be of either an incremental type or an absolute type.

The method of the present invention is applicable not only to the above-mentioned rotary type web cutter but also to self-propelled type web cutters, and is also extremely effective in eliminating steady torque fluctuations that occur in ordinary crank mechanisms, cam mechanisms, etc. This is effective, and furthermore, as long as the form of the torque cancellation signal e is the same as that of the speed command signal d, it is not limited to the voltage as described above, but may be output in the form of a current.

As described above, in the method of the present invention, the torque cancellation signal e based on the torque compensation signal stored in advance corresponding to the position of the cutting blade 2°2 is used for the closed loop speed difference correction control. Since the torque fluctuation elimination control is performed in addition to the loop, it becomes possible to properly eliminate the steady torque fluctuations that occur with the operation of the cutting blades 2, 2 in a timely manner, and as a result, the torque fluctuation It is possible to suppress speed fluctuations of the cutting blades 2, 2 due to fluctuations, and it has become possible to cut the web 1 with high precision.

Moreover, the drive control system of the present invention has a torque memory 1 in addition to the conventional one.
3, it is possible to avoid complication of the control system and to provide a relatively inexpensive control system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the drive control system of the conventional method, FIG. 2 is a block diagram showing the drive control system of the method of the present invention, and FIG. 3 is an explanatory diagram of the main parts of the method of the present invention. 1 is a web, 2 is a cutting blade, 3 is a length measuring roll, 4 and 12
is a pulse generator, 5 is a digital regulator, 6 is a
is a cutting length setting device, 7 is an analog regulator, 8 is a power stack, 9 is a tacho generator, 10 is a DC motor, 11 is a transmission mechanism, 13 is a torque memory, 14 is a sensor, DM is a digital memory, DAC is a D/A It is a converter.

Claims (1)

[Claims] 1. A method for eliminating steady torque fluctuations of a web cutter for cutting a web continuously transported in one direction to a desired length without stopping the running of the web, the method comprising: The torque compensation signal is input into an analog regulator in an open loop according to the position detection signal of the cutting blade from a torque memory storing a torque compensation signal in advance corresponding to the position of the cutting blade, and the motor for driving the cutting blade is controlled as described above. A method for eliminating torque fluctuations in a web cutter, characterized in that power is generated and controlled so that steady torque fluctuations can be eliminated.