JPS6381223A - Predicting method for saw-tooth lack for saw-tooth cutting machine - Google Patents

Abstract

PURPOSE:To predict a saw-tooth lack by comparing the deterioration predictive curve of saw teeth with a vibrating speed value Vcr corresponding to the deficit of a saw tooth which is found according to facility conditions. CONSTITUTION:The vibrating speed is found from vibration acceleration detected by an acceleration sensor. This vibrating speed contains a high cutting frequency component in addition to vibration components characteristic to a saw-tooth cutting device, so this high frequency component is removed by a filter, etc. This vibrating speed value increased and decreases with time, i.e. the number of times of cutting. Then the deterioration predictive curve of saw teeth is found from the vibrating speed value Vcr. The vibrating speed corresponding to the state of deterioration to the extent where the saw teeth can not be used is found previously from the features of facilities, the number of rotations of the saw teeth, and others. Then the remaining number of times of cutting is calculated from said deterioration predictive curve and vibrating speed value found according to the conditions of the facilities to accurately predict the lack of saw-tooth.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for predicting breakage of saw teeth in advance in a saw cutting machine for steel materials, etc.

[Conventional technology and its problems]

Rotary saws are widely used as vibrator cutters and so-called edge millers. This type of saw cutter has the problem that the saw teeth break during operation, and if such a break occurs in even one of the saw teeth, the other saw teeth will also break immediately.
All the saw teeth will chip in a short period of time.

For this reason, conventional methods have been established for detecting saw tooth loss without stopping the saw cutter, such as: - by the operator listening for abnormal noises - by observing the cut surface - by detecting an increase in cutting current. . Also, find the vibration speed of the sawtooth,
A method of detecting sawtooth defects using this method was proposed in a patent application published in 1986.
It has already been proposed by the applicant in No. 2919.

However, in some equipment, stopping the equipment and replacing the saw teeth after detecting a breakage of the saw teeth leads to a decrease in yield.

For example, the traveling cutting machine at an electric resistance welding pipe factory is equipment on a continuous line, so it can only be stopped between raw material coils, resulting in many failures between the time a saw tooth defect is detected and the time it is replaced. It turns out.

[Summary of the invention]

The present invention has been made in order to improve the problems of the prior art described above.The present invention detects the vibration speed of the sawtooth, calculates a predicted sawtooth deterioration curve from this detected value, and uses the predicted deterioration curve and the equipment conditions to This method is characterized by comparing the vibration velocity values corresponding to the sawtooth defects determined by the method.

This comparison makes it possible to determine whether the next coil can be completely processed during the current coil processing.

If processing is not possible, an instruction to replace the saw blade is given before starting the next coil processing.

This will be explained in more detail below.

First, the detection of the vibration speed of the sawtooth was carried out in the above-mentioned patent application filed in 1986-16.
The same method as No. 2919 may be used.

That is, first, a vibration sensor for measuring vibration is attached to the sawtooth drive shaft, the bearing box of the intermediate shaft, the clamping means of the object to be cut, etc. An acceleration sensor (such as a piezoelectric element type acceleration sensor) is usually used as this vibration sensor, and the vibration speed is determined from the vibration acceleration detected by the sensor. Since the vibration velocity determined in this way includes a high-frequency cutting frequency component in addition to vibration components specific to the device, this high-frequency component is removed by a filter or the like. As shown in FIG. 1, this vibration velocity value gradually increases as time passes (as the number of cuts increases). An interpolation curve is determined using a set of these values. This interpolation curve is suitably obtained by substituting the vibration velocity value into the following straight line or index prediction formula.

however X-work: Temporal information (number of cuts, etc.) y: Actual measured value of degree of deterioration (photographed value, etc.) Number of required data: ↓≧2 Others: yJ must be a positive number.

(xl represents elapsed time, so it is non-negative It is obvious that it is. ) ■ Straight line Y-a-B-bX.

Here a-yu (history y2-M:xyu)n kun
Word b-8xy/5xx n: Total number of data (2 or more) ■ Exponent Let y=a-bX.

Here, a=eA, b-eB 8=Sx y /Sx x Sxx:> Same as straight line, 3xy=Σ(xi-also)(
j! nyt Y)j;l or #= Y-1<'XJl
・y↓)n! =.

n U 〃 On the other hand, the vibration speed (Ver) corresponding to the state in which the saw blade has deteriorated to the point where it cannot be used is determined in advance from ■ Characteristics of the equipment ■ Rotation speed of the saw blade ■ Characteristics of the material to be cut, etc.

From the previously obtained deterioration prediction formula and this Ver, the remaining number of cuts from the current state to Ver is calculated as shown in FIG.

The number of cuts that must be made for each coil is clear from the coil length and product length. If the number of remaining cuts calculated at the end of the coil is less than the number of cuts for the next coil, a saw blade replacement instruction is issued before starting the next coil process.

The above makes it possible to predict sawtooth loss.

[Equipment example]

The method of the present invention was applied to a traveling cutting machine at an ERW pipe factory. A block diagram of the device is shown in FIG.

Here, vibration is detected by a vibration sensor 1, noise is removed by HPH3 and LPH4 via a charge amplifier 2, and sawtooth vibration is obtained. After rectifying with a rectifying amount 6 via an amplifier 5, the peak value is detected by a peak hold circuit 7, digitized by an A/D converter 8, and converted into a CP
The process of the present invention is performed in U9. This result is CRT
It is displayed externally by IO and buzzer 11.

[Effects of the Invention] As explained above, according to the method of the present invention, chipping of saw teeth can be accurately predicted, so that saw teeth can be replaced in advance, which improves work efficiency and yield. can be achieved.

[Brief explanation of the drawing]

1 and 2 are graphs showing the relationship between the number of cuts and vibration speed to explain the method of the present invention, and FIG. 3 is a block diagram of an apparatus for implementing the method of the present invention. Figure 2 Number of row cuts

Claims (1)

[Claims] The system is characterized by detecting the vibration speed of the sawtooth, calculating a predicted sawtooth deterioration curve from this detected value, and comparing this deterioration prediction curve with the vibration speed value corresponding to sawtooth defects determined according to the equipment conditions. A method for predicting saw tooth loss in saw cutting machines.