JPH02145290A - Cutting method for long size article - Google Patents

Abstract

PURPOSE:To effectively cut a long size article to a given length by irradiating laser light on the long size article, generating pulse for every amount of unit movement of the long size article from scattered light and detecting the prescribed amount of the long size article from the number of the pulses. CONSTITUTION:When laser light L1, L2 are irradiated on a long size article (for example, corrugated board) A which is supplied in a longitudinal direction, scattered light Lr with its frequency from the long size article A is subjected to Doppler deviation proportional to the moving speed of the long size article A according to Doppler effect. Pulse is, therefore, generated from a pulse output device 11 for every amount of the unit movement of the long size article according to the Doppler deviation. The prescribed amount of the movement of the long size article A is detected by a controller 6 from the number of the pulses. Then, the long size article A is cut to a prescribed length according to the amount of the detected movement.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for cutting a longitudinally fed elongated object such as a cardboard into a predetermined length.

(Prior Art) Normally, when cutting a long object such as a cardboard into a predetermined length while feeding it in the longitudinal direction, a cutting device such as a rotary cutter installed in the middle of the feeding is used to cut the long object into a predetermined length. The machine is operated every predetermined movement amount to cut a long object. At this time, for example, if the long object is a cardboard, in order to detect the amount of movement thereof, conventionally, a measuring wheel that contacts the cardboard and rotates as it moves is provided, and the measuring wheel is connected to the measuring wheel. A pulse generator generates a pulse for each unit rotation amount of the measuring wheel and therefore for each unit movement amount of the cardboard, detects a predetermined amount of movement of the cardboard from the number of pulses, and operates the cutting device accordingly. The cardboard was being cut.

However, with this cutting method, long objects such as cardboard have slippery surfaces, so slippage often occurs between the measuring wheel and the long object, and in such cases, the number of pulses and The actual movement distance of the long object does not match, and the long object is not cut to a predetermined length.

In addition, since the long object and the measuring car are in mechanical contact,
There is a risk that the measuring wheel may damage the long object, and the measuring wheel will wear out, making the above-mentioned slippage more likely to occur.

Furthermore, vibrations and the like during the movement of a long object are directly transmitted to the measuring wheel, which tends to cause misalignment and play in the connection between the measuring wheel and the pulse generator.

(Problems to be Solved) The present invention eliminates such inconveniences and reliably detects a predetermined amount of movement of a long object such as a corrugated board fed in the longitudinal direction without bringing a measuring wheel or the like into contact with the object. It is an object of the present invention to provide a method that can reliably detect a predetermined amount of movement of a long object and cut it into a predetermined length without damaging the long object.

(Means for Solving the Problem) In order to achieve the above object, the method for cutting a long object of the present invention irradiates the long object with a laser beam while feeding the long object in the longitudinal direction. A pulse is generated for each unit movement distance of the long object from the scattered light scattered by the long object due to the Doppler effect during irradiation, and a predetermined movement distance of the long object is detected from the number of pulses. The method is characterized in that the long object is cut according to the detection.

(Function) According to this means, when the elongated object fed in the longitudinal direction is irradiated with a laser beam, the frequency of the scattered light from the elongated object is proportional to the moving speed of the elongated object due to the Doppler effect. Since the object is subjected to a Doppler shift, the pulse is generated for each unit movement of the elongated object according to the Doppler deviation, and a predetermined movement amount of the elongate object is detected from the number of pulses. Then, the long object is cut in accordance with the detection.

(Example) As an example of the method for cutting a long object of the present invention, a method for cutting cardboard will be outlined with reference to FIG.

FIG. 1 is a schematic explanatory diagram thereof.

In FIG. 1, 1 is a laser beam L
3 is a cutting device that cuts the cardboard A with rotary cutters 4, 4.

The cardboard A is conveyed on the conveyor 2 via the pulse generator 1 to the cutting device 3, and after being cut in the cutting device 3, is carried out on the conveyor 5.

Then, when the cardboard A passes through the pulse generator 1, the pulse generator 1 sequentially generates the pulses, and the pulses are input to the control device 6 of the cutting device 3.

The control device 6 counts the number of input pulses to detect a predetermined movement amount of the cardboard A, and thereby operates the rotary cutter 4.4 of the cutting device 3 to cut the cardboard A.

Therefore, the cardboard A is cut every predetermined amount of movement,
As a result, the cut cardboard A has a predetermined length.

Next, the configuration and operation of the pulse generator 1 will be explained in detail with reference to FIGS. 2 and 3(a) to 3(C). FIG. 2 is a schematic explanatory diagram showing the configuration of the pulse generator 1, and FIG.
) to (C) are diagrams showing waveforms of generated pulses.

In FIG. 2, this pulse generator 1 includes a laser oscillator 7 that generates laser light to irradiate the cardboard A, and a laser oscillator 7 that generates laser light to irradiate the cardboard A.
a photoelectric converter 8 that converts the scattered light of the laser beam irradiated to the electrical pulse into an electrical pulse having that frequency, an amplifier 9 that amplifies the electrical pulse, and a frequency divider that divides the frequency of the pulse amplified by the amplifier 9. 10, and a pulse output section 11 that generates two pulses with different phases from the pulse frequency divided by the frequency divider 10, and the pulse from the pulse output section 11 is input to the control device 6, The control device 6 detects a predetermined movement amount of the cardboard A corresponding to a preset cutting length of the cardboard A from this number of pulses.

The laser oscillator 7 is He-Ne with a wavelength of λ-632, 8 nm.
A laser beam is output toward the cardboard A, and the laser beam is converted into a laser beam LI+Lx by the beam splitter 12.
divided into two.

Laser light among the two divided laser beams L+ and Lz.

The laser beam L! is irradiated obliquely from the upstream side onto the top surface of the cardboard A being conveyed via mirrors 13 and 14, and the laser beam L! is irradiated obliquely onto the top surface of the cardboard A from the downstream side via the mirror 15, and both intersect at the same irradiation position on the cardboard.

At this time, the laser beam is emitted at the irradiation position.

are affected by the Doppler effect according to the moving speed of step pole A, and their respective frequencies change and interfere with each other.
This causes scattered light from the irradiation position.

A beat occurs at the laser beam L1. If the angle formed by L2 is Φ, and the deviation angle from the right angle between the normal line of both laser beams L+ and Lx and the cardboard A is Δθ, then as is well known, ax K, ・ ■ ... (1) However, K
It is given by l=2/λ·5in(Φ/2)·cos Δθ, and is proportional to the moving speed V of the cardboard A.

The scattered light is input to the photoelectric converter 8 via the mirror 16, converted into an electric pulse by the photoelectric converter 8, and then amplified by the amplifier 9. The amplified pulse becomes a whisker-like pulse P having the frequency f as shown in FIG. 3(a).

This pulse P, is frequency-divided via the frequency divider 10, and the third
A rectangular pulse P2 is obtained as shown in FIG. 3(b). If the pulse Pt is divided into 1/K t by the frequency divider 10, the frequency ft of the pulse P2 is calculated from the above equation (1) as fz - ft /Kg = K + /K t・■... (2) becomes.

Here, for example, to Kl/! By setting the value of 2 so that it becomes -1, f and -V can be obtained from the above equation (2), and considering the frequency ft as the number of pulses per unit time, the cardboard A
If the unit of the moving speed ■ is -s/sec, the number of pulses per moving distance lll11 to the cardboard is f t / V
-1. Therefore, the unit movement amount of cardboard A is 15
If it is 5m, pulse P! for each unit movement amount! is output from the frequency divider lO.

In this way, set the unit movement amount of cardboard A appropriately,
According to the unit movement amount, Kl/ of equation (2) is obtained! If set appropriately, the frequency divider 10 generates a pulse P! for each unit movement of the cardboard A! occurs.

In principle, by inputting this pulse P- into the control device 6 and counting the number of pulses, it is possible to detect a predetermined movement amount of the cardboard A, but as in this embodiment, when the cardboard A is When being conveyed on the conveyor 2, subtle vibrations occur in the cardboard A, which causes the frequency f+ to vibrate. For this reason, whisker-like pulses may be mixed into the rectangular pulses P2 produced by the frequency divider 10, and in such a case, the whisker-like pulses are also counted by the control device 6 and the pulses Pz are not counted correctly.

Therefore, in this embodiment, the pulse P- is inputted to the pulse output section 11, and the pulse output section 11 outputs the pulse P- as shown in FIG. 3(C).
As shown, a pulse P3 having the same period as the pulse P2 and a pulse P4 having a phase delay of 90 degrees with respect to the pulse P3 are generated. Then, these pulses P3+P4 are sent to the control device 6.
The control device 6 counts the pulse P or P4 when the pulse P4 is manually applied following the pulse P3, thereby preventing the whisker-like pulse from being counted due to the vibration of the cardboard A. . It goes without saying that the phase delay of the pulse P4 with respect to the pulse P may be a value other than 90 degrees.

Therefore, the control device 6 reliably counts the pulses generated by the pulse generator 1 for each unit movement amount to the cardboard, detects the predetermined amount of movement, and in response to the detection, ensures that the cardboard A reaches the predetermined length. It is severed immediately.

(Effects) As is clear from the above explanation, according to the method for cutting a long object of the present invention, a laser beam is irradiated onto the long object, and a pulse is generated from the scattered light for each unit movement of the long object. By generating pulses and detecting a predetermined amount of movement of the long object from the number of pulses, it is possible to reliably detect the predetermined amount of movement of the long object without damaging the long object, and to detect the predetermined amount of movement according to the detection. By cutting a long object, the long object can be reliably cut into a predetermined length.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram for explaining an outline of an example of the method for cutting a long object according to the present invention, FIG. 2 is a schematic explanatory diagram showing the configuration of a pulse generator, and FIGS. (C) is a diagram showing the waveform of generated pulses. A...Long object (cardboard) LI, L8...Laser light. ~P4... Pulse... Scattered light FIG, 2 (C)

Claims (1)

[Claims] 1. The long object is irradiated with a laser beam while being fed in the longitudinal direction, and the unit movement of the long object is determined from the scattered light scattered by the long object due to the Doppler effect during the irradiation. A method for cutting a long object, characterized in that a pulse is generated for each amount, a predetermined movement amount of the long object is detected from the number of pulses, and the long object is cut in accordance with the detection.