JPS5834742A - Method of controlling cutting feed in chamfering machine for steel pipe - Google Patents

Abstract

PURPOSE:To make it possible to carry out exact management of working by comparing a calculated actual feed with a set feed and by controlling the advancing speed of a tool so that both feeds are made equal together. CONSTITUTION:The rising of variation in the armature current of a motor 4 for ratating a chamfering tool 13 which is arranged for performing the finish cutting of one end face of a steel pipe P, is detected by a current detector 10 for obtaining a cutting initiation signal. Meanwhile, the advancing speed of a carriage 2 is detected by a tachometer generator or a differential transducer 11 and is delivered to a cutting mergin converter 12 which delivers a cutting mergine converting signal to an arithmetic unit 14 together with a rotation detecting signal from a tachometer generator 13 mounted in a decelerator 5 so that a feed per one rotation is calculated in the arithmetic unit 14 and is indicated on a display 15. Further, a flow regulating valve 9 in a carriage feeding hydraulic circuit is controlled to make the set feed and the feed per one rotation equal together which are compared by a comparator 16. With this arrangement, the feed is exactly controlled in accordance with the quality of the material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting feed amount control method in a steel pipe chamfering machine.

The end face of steel pipes cut into predetermined lengths using a circular saw or disc cutter may have unevenness, burrs, curls, etc.
It is necessary to cut the end face of the cut steel pipe using a chamfering machine.

In a chamfering machine that finishes cutting the end face of a steel pipe, the appropriate feed rate (mm) of the cutting tool generally depends on the material of the cutting tool.
/rev) is determined.

However, in actual operation, the actual feed of the cutting tool cannot be clearly grasped, making it impossible to properly manage the operation, which causes a reduction in the life of the cutting tool.

The present invention has been made to solve the above-mentioned conventional problems, and an example of its implementation will be described below with reference to the drawings.

In the figure, 1 is a chamfering machine that finishes cutting the end face of a steel pipe P, 2 is a carriage in the chamfering machine 1, and 3 is a motor that is rotated via an electric motor 4 and a speed reducer 5 provided on the carriage 2. It is a cutting tool.

The carriage 2 is moved forward in the direction of the steel pipe P at a rapid traverse speed by supplying pressure oil to the rear chamber of a hydraulic cylinder 7 through an electromagnetic switching valve 6.

returned to the tank.

Further, the carriage 2 is retracted to the standby position by supplying pressure oil to the front chamber of the hydraulic cylinder 7 via the electromagnetic switching valve 6 and the electromagnetic on-off valve 8.

Further, the carriage at the start of cutting the end face of the steel pipe P17) is moved forward at a transport speed by adjusting the flow rate regulating valve 9 connected in parallel with the electromagnetic on-off valve 8. .

Now, when the cutting tool 3 starts cutting the end face of the steel pipe P, the armature current in the electric motor 4 rises rapidly. A current detection signal (cutting start detection signal) vi- is obtained from the current detector 10.

Further, the carriage 2 is provided with, for example, a tachometer generator 11 (which may be a differential transformer) for detecting the amount of advance of the carriage 2. The current detection signal [cutting start detection signal] is input to the cutting allowance converter 12, and the cutting allowance converter 12 calculates the amount of advance of the carriage 2 from the cutting start point, that is, the cutting allowance. , obtain a cutting allowance conversion signal.

The speed reducer 5 of the cutting tool 3 includes a rotation detection pulse tacho generator 13 that detects the rotation speed of the cutting tool 3.
is provided, and the rotation detection signal from the rotation detection pulse tacho generator 13, the cutting allowance conversion signal, and the current detection signal (cutting start detection signal) are input signals to the computing unit 14, This calculator 14 calculates the minute feed (''/) from the start of cutting to the completion of cutting.
is calculated, and the calculated transmission signal is displayed on the display 15 every moment.

Further, the feed calculation signal from the calculation unit 14 and the appropriate feed (II/rev) setting value suitable for the material of the cutting tool 3 are compared and calculated by the comparison calculation unit 16, and the two match based on the comparison calculation signal. The flow rate adjustment valve 9 is controlled accordingly.

As described above, according to the method of the present invention, when cutting the end face of a steel pipe in a chamfering manner, it is possible to control the cutting tool in the chamfering manner to an appropriate feed rate ('r e V ) commensurate with the material. Therefore, the feed can be made constant and stable, which can significantly contribute to extending the life of the cutting tool.

Note that the method of the present invention is applicable not only to chamfering for steel pipes, but also to control in the case of feed cutting while rotating the material to be cut or the cutting tool.

[Brief explanation of the drawing]

The figure is a block diagram showing an example of implementing the method of the present invention.

Claims (1)

[Claims] The rise of the armature current change in the rotating electric motor of the cutting tool is detected as the start of cutting, and the feed amount is calculated from the amount of advance of the cutting tool from the time when the cutting start is detected and the rotation speed of the cutting tool. A method for controlling the forward speed of a cutting tool by comparing and calculating the feed amount calculation value and the feed position setting value, and using this comparison calculation value.