JPS5822644A - Method of controlling machining allowance by steel pipe chamfering machine - Google Patents

Abstract

PURPOSE:To eliminate wasteful cutting of a steel pipe and to improve the life of a tool, by providing a chamfering machine carriage with a steel pipe end surface detecting sensor thereby keeping constant the distance between the point where slowing-down of the feeding speed of the chamfering machine carriage is started and a steel pipe end surface. CONSTITUTION:The carriage 4 is moved forward at a quick feeding speed, and when the steel pipe end surface detecting sensor 6 detects the end surface of a steel pipe 1, an eletromagnetic valve 9 is cut, a pressurized oil in a front chamber of a hydraulic cylinder 8 is returned via an electromagnetic valve 7 to an oil tank, and the carriage 4 is moved forward at a slow feeding speed. When cutting of the end surface of the steel pipe 1 by a cutting tool 3 is started, since an armature electric current of a motor 10 rises, the current is detected by a current detector 13, and is inputted into a relative operator 14. The distance of the carriage moved from this inputted point and a predetermined machining allowance are compared and operated, and when they coincide, the cutting is stopped by a signal outputted from the relative operator 14.

Description

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

As shown in FIG. 1, the end face of the steel pipe 1 cut by the flying cut-off machine has a bulge of thickness, so it is necessary to cut the end face with a chamfering machine to a size 11 that eliminates this bulge part 1a.

When the steel pipe 1 is transferred onto the center line of the chamfering machine 2 as shown in FIG.
It is common for the distance between the two to vary.

When cutting the raised portion 1a of the steel pipe 1 with the chamfering machine 2, the distance between the end face of the steel pipe 1 and the standby position a of the cutting tool 3 is a predetermined distance, as shown in FIG. If so, the cutting tool 3 advances in the direction of the solid line arrow from the standby position α at a rapid traverse speed of vl, is slowed down to a slow traverse speed of vz at a predetermined slowdown start point, and moves forward at a distance from the standby position α. When the steel pipe 1 moves forward, the end face of the steel pipe 1 is cut at a cutting feed rate of υ3 to the minimum necessary dimension -es i at which the raised portion 1a disappears, and at the cutting completion position C, it retreats in the direction of the dashed line arrow and returns to the standby position α. .

However, as mentioned above, due to the accuracy limitations of steel pipe conveying equipment, the distance between the end face of the steel pipe 1 and the standby position α of the cutting tool 3 varies, and the standby position α of the cutting tool 3 and the slowdown start point vary. b1 Since the cutting completion position C is set to a certain control pattern, for example, as shown in FIG. 3B, the end surface of the steel pipe 1 is longer than the end surface of the steel pipe 1 in FIG. 3A by the length of the cutting tool. If the steel pipe 1 protrudes in the direction of the standby position α of No. 3, the steel pipe 1 will be needlessly cut longer by the right portion.

For example, as shown in FIG. 3C, the end surface of the steel pipe 1 is
1. If the end face of the steel pipe 1 in FIG. 3A is 6 minutes longer than the end face of the steel pipe 1, and the cutting tool 3 protrudes in the direction of the standby position a, beyond the slowdown start point 5, to the region of the rapid traverse speed v1.1. , instead of wastefully cutting the steel pipe 1 for a length of e3 minutes, the cutting tool 3 starts cutting at the rapid feed speed νl, resulting in an overload, which causes the cutting tool 3 to break. occurs.

Furthermore, if the adjustment setting of the cutting completion position C is inappropriate, the end face of the steel pipe 1 cannot be cut to the minimum required dimension -e+ where the raised portion 1α is eliminated,
There were various problems such as having to re-cut the parts due to insufficient cutting.

The present invention is an attempt to solve these conventional problems, and an example of its implementation will be described below with reference to FIG. 4.

As shown in FIG. 4, a sensor 6 for detecting the end face of a steel pipe is provided at the lower front surface of the carriage 4 in the chamfering machine 2, located forward of the cutting tool 3 via an arbitrary arm 5.

The carriage') 4 is connected to the raised portion 1a of the steel pipe 1.
When cutting, pressure oil is supplied to the rear chamber of the hydraulic cylinder 8 via the electromagnetic switching valve 7, so that the steel pipe 1 is advanced at a rapid traverse speed νl.

In this case, the pressure oil in the front chamber of the hydraulic cylinder 8 is returned to the oil tank via the electromagnetic on-off valve 9 and the electromagnetic switching valve 7.

Further, the cutting tool 3 is rotated via an electric motor 10 and a speed reducer 11 provided on the carriage 4.

When the carriage 4, especially the cutting tool 3, advances from its standby position α at a rapid traverse speed v1, and the end face of the steel pipe 1 is detected by the steel pipe end face detection sensor 6, a detection signal from the steel pipe end face detection sensor 6 causes The electromagnetic on-off valve 9 is shut off, and the pressure oil in the front chamber of the hydraulic cylinder 8 passes through the flow rate adjustment valve 12 connected in parallel with the electromagnetic on-off valve 9, and flows into the oil tank via the electromagnetic switching valve 7. Since the carriage 4 is returned, the carriage 4 moves forward at a slow feed speed υ2.

When the cutting tool 3 starts cutting the end face of the steel pipe 1, the armature current in the electric motor 10 rises rapidly. The current detection signal (cutting start detection signal) from the current detector 13 is sent to the comparison calculator 1.
It is given as an input signal for operation of No.4.

The comparison calculator 14 is supplied with a moving distance detection signal from, for example, a tacho generator 15 for detecting the moving distance of the carriage 4, and a cutting allowance setting signal, and the current detection signal (cutting start signal) is used for comparison calculation. The moving distance (advance amount) of the carriage 4 from the time when it is given as an input signal for operation to the unit 14 is compared with the set cutting allowance, and when this advance amount and the set cutting allowance match, the comparator 14 In response to the output signal, the electromagnetic switching valve 7 is switched, the electromagnetic on-off valve 9 is turned on, the hydraulic pressure 7 and the cylinder 8 are operated backward, and the carriage 4, especially the cutting tool 3, is returned to the standby position α, and the steel pipe 1 is Complete end face cutting.

The steel pipe end face detection sensor 6 may be, for example, a contact-type detection switch, but preferably a non-contact type, for example, a photoelectric detection switch. Alternatively, if the operation of the hydraulic cylinder 8 when advancing the carriage 4 is stable and the cutting feed rate is repeatedly held constant under the same setting conditions, the current detection The timer is activated from the cutting start point detected by the device 13, and the cutting allowance (
After a certain period of time corresponding to the dimension -6+) has elapsed, the time-up signal switches the electromagnetic switching valve 7, turns on the electromagnetic on-off valve 9, causes the hydraulic cylinder 8 to move backward, and the carriage 4, especially the cutting tool 3, is turned on. may be returned to the standby position a.

As described above, according to the method of the present invention, even if there are variations in the distance between the end face of the steel pipe to be cut and the standby position of the cutting tool in the chamfering machine, the feed rate of the chamfering machine carriage starts slowing down. Since the distance between the point and the end face of the steel pipe is always constant, cutting does not start while the carriage is still in rapid traverse, and therefore the trouble of cutting tools breaking due to shock can be completely prevented.

In addition, since the carriage's slow feed distance and cutting feed distance are always constant, it is possible to shorten cycle time, eliminate unnecessary cutting of steel pipes, improve the life of cutting tools, and ensure that there is no shortage of cutting amount. It can be prevented.

Note that the method of the present invention can be applied not only to steel pipes but also to end face cutting allowance control when there is variation in the axial end face positioning of the material to be cut.

[Brief explanation of drawings]

Figure 1 is a longitudinal cross-sectional view showing one end of a steel pipe cut by a flying cut-off machine, Figure 2 is an explanatory diagram showing the positional relationship between the steel pipe before cutting and the cutting tool in the chamfering machine, and Figure 3 A, B, and C are explanatory diagrams showing the relationship between the steel pipe end face position and cutting feed status, respectively, and FIG. 4 is a block diagram showing an example of implementation of the method of the present invention. Applicant (125) Kawasaki Steel Co., Ltd. Rod 20 Figure 3 Figure 4

Claims (1)

[Claims] The forward speed of the chamfering machine carriage is slowed down by the steel pipe end face detection signal from the steel pipe end face detection sensor provided in front of the cutting tool position in the chamfering machine carriage, and the cutting tool rotating electric motor is slowed down. The rise of the armature current change is detected as the start of cutting, and the amount of advance of the chamfering machine carriage from the time when the start of cutting is detected is compared with the set cutting allowance, and when this amount of advance matches the set cutting allowance. , a cutting allowance control method in a steel pipe chamfering machine, characterized by retracting a chamfering machine carriage to a standby position.