JPS5813320B2 - Automatic cutting device control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves drawing out a strip or linear material from an uncoiler while flattening it through a leveler that operates at a constant speed and a feeder that operates periodically. In an automatic cutting device that automatically cuts strips into a predetermined length using a cutter that operates at the same repetition rate as the feeder, the loop length of the strips accumulated between the leveler and the feeder should not be less than a predetermined value. The present invention relates to a loop storage amount adjustment device that adjusts the amount of storage.

Conventionally, as shown in FIG. 1, a leveler 4 is operated by a leveler motor 3 that rotates a strip 2 fed from an uncoiler 1 at a constant speed, and a feeder motor 5 is driven periodically in response to a feeder start signal. An automatic cutting device is known in which the strip member 2 is pulled out through a feeder 6 operated by a feeder 6, and the pulled strip member 2 is automatically cut into a predetermined length by a cutter 7 operated at the same repetition rate as the feeder 6.

Note that reference numbers 8, 9, and 10 in FIG. 1 indicate guide rollers for the strip material.

As shown in the figure, a loop 11 is formed between the guide roller 9 and the guide roller 10, and the strip material is accumulated, and the amount of loop accumulation changes when the feed speed of the leveler 4 and the feed speed of the feeder 6 are equal. However, when the two feed speeds are different, this loop accumulation amount changes.

For example, when the feed rate of the feeder 6 is greater than the feed rate of the leveler 4, the loop accumulation amount decreases with each cutting operation, thereby interfering with the operation of the device.

An object of the present invention is to provide a control device for an automatic cutting device capable of ensuring that the length of the loop of strips accumulated between the leveler and the feeder of the automatic cutting device as described above is always maintained at a predetermined value or more. The goal is to provide the following.

FIG. 2 illustrates the principle of the present invention, and in this drawing,
Vf is the feeder feed speed, the area Sf of the part surrounded by OABC is the feeder feed length per one cutting operation, v1 is the leveler feed speed, the area Sl of the part surrounded by OABC is the leveler feed length per one cutting operation, t1 is the time required for one cutting operation (one feed time), Δt1 is an adjustment time as will be explained later, and Ts and Ts' are the supply points of the cutting operation start signal as explained later, respectively.

When one cutting operation is performed, feeder feed length Sf
When Sf is equal to the feed length S1 of the leveler, the loop accumulation amount does not change, but when Sf is not equal to Sl, the loop accumulation amount changes. For example, when Sf is greater than SL,
The loop accumulation amount is △S=Sf−S every time a cutting operation is performed.
It decreases by L.

On the other hand, the aforementioned feeder start signal for starting the feeder motor is generated in response to a cutting operation start signal that determines the starting point of each cutting operation.

The present invention corrects ΔS by delaying the generation point of the feeder start signal generated in response to each cutting operation start signal by Δt1−ΔS/Vl when ΔS=Sf−Sl≧0. This is how it was done.

△L1 is called the adjustment time because it represents the time to be delayed, in other words, the time to be adjusted. During the cutting operation period in which this adjustment is performed, the loop accumulation amount is equal to the previous cutting operation period. It is clear from Figure 2 A, the mouth, that there is no change from what immediately follows.

That is, if no adjustment was made, the feeder start signal would be applied at time Ts in Figure 2A, and ΔS=Sf.
- The second cutting operation is started with a decrease in the loop accumulation amount of the length of Sl, and the similar decrease in the loop accumulation amount occurs in the subsequent third, fourth, etc. cutting operations, and the loop accumulation amount If becomes zero, the feeder 6 will not be able to feed out the strip to the required length, which will hinder the operation of the device. However, by making this adjustment, the leveler will be able to replenish the shortfall △S. The supply point of the feeder start signal for the second cutting operation is delayed by S/Vl to time T.
s', the second cutting operation is started after the decrease in the loop accumulation amount is brought to zero, and the decrease in the loop accumulation amount is also made to be zero in subsequent cutting operations.

When ΔS<0, the feeder start signal is supplied at the same time as when ΔS-00, that is, at time Ts in FIG. 2A.

Even if the loop storage amount is not adjusted when ΔS is O, the amount will increase for each cutting operation and will not interfere with the operation of the device.

The reason for this is that the reference timing Ts of the feeder start signal can be set in advance in a range such that ΔS≧0 in consideration of the leveler feed speed Vl and the feeder feed speed Vf. <0
This is because even if there are times when this happens, it will never continue.

FIG. 3 is a circuit diagram of an embodiment of the present invention, in which 13 is a subtracter, 14 is a digital-to-analog converter, 15 is a length-to-hour converter, 16 is a timer, and 17 is a one-shot Each multivibrator is shown.

A block comprising a subtracter 13 and a digital-to-analog converter 14 compares the feeder feed length and the leveler feed length, and when the former value is greater than or equal to the latter value, generates a difference signal representing the difference in length. A generating circuit 12 is configured.

That is, the subtracter 13 generates a number of pulses proportional to the feeder feed length from a suitable means (not shown) connected to the feeder and a leveler feed from a suitable means (not shown) connected to the leveler. If there are more pulses than the latter, a digital signal representing the difference between the pulses is generated, which the converter 14 converts into an analog value.

The length-to-time converter 15 converts the analog value representing this length difference into time by dividing it by the leveler feed rate, and supplies it to the timer 16 as a time setting signal.

The timer 16 is also periodically supplied with a cutting operation start signal Ts.

After receiving the signal Ts, the timer 16 sends a signal to the one-shot multivibrator 17 when the time set by the time setting signal from the converter 15 has elapsed, and at this time, the one-shot multivibrator 17 generates a feeder start signal. Then, the feeder motor 5 is started and the subtracter 13 is cleared.

In this way, the timer 16 causes a delay between the supply time of the cutting operation start signal and the supply time of the feeder start signal according to the value of the time setting signal from the converter 15 when the time setting signal is not zero. When the setting signal is zero, the feeder start signal is supplied without such a delay.

In the case of conventional technology that controls the leveler feed speed to keep the loop length within a predetermined range, the power supply device for the leveler motor must have a configuration that allows variable speed control, requiring an expensive control device. .

On the other hand, in the case of the present invention, the leveler motor only needs to be operated at a constant speed, and high speed accuracy is not required. It is only necessary to provide a simple time element to delay the feeder start signal.

As can be seen from the above description, the present invention provides a very practical device for automatically adjusting the length of the strip accumulated between the leveler and feeder of a length cutting device.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an automatic cutting device to which the present invention is applied, FIG. 2 is a graph illustrating the principle of the present invention, and FIG. 3 is a circuit diagram showing an embodiment of the present invention. 1: Uncoiler, 2: Strip member, 3: Leveler motor, 4
: Leveler, 5: Feeder motor, 6: Feeder, 7: Katsutata, 11: Loop, 12: Difference signal generation circuit, 15: Length one hour converter, 16: Timer, 17: One-shot multiple-by-break.

Claims (1)

[Claims] 1. A strip or linear strip is pulled out from the uncoiler through a constant-speed operating leveler and a periodically operated feeder, and the drawn strip is automatically cut to a predetermined length by a cutter that is operated at the same repetition rate as the feeder. In an automatic cutting device that cuts the feeder feed length and leveler feed length, when the feeder feed length exceeds the leveler feed length, a difference signal is generated that represents the difference between the feeder feed length and the leveler feed length. a difference signal generation circuit that converts the difference signal into time by dividing this difference signal by the leveler feed speed, and a converter that converts this difference signal into time by dividing it by the leveler feed speed, and a cutting operation start signal given at the beginning of each cutting operation that is delayed by the converted time. A control device for an automatic cutting device, characterized in that it comprises means for forming a signal, using the signal to start the feeder and clearing a difference signal generating circuit.