JPH0857749A - Milling tool chipping detecting device - Google Patents

Abstract

PURPOSE: To provide a milling tool chipping detecting device enabling the unmanned operation of slitting or the like using thin milling tools subject to damage. CONSTITUTION: Air sensor heads 19 has groove parts 19a into which the outer peripheral parts of plural thin milling tools 17 (metal saw) fitted to a cutter arbor 9 are fitted, and air passages 19b to which nozzles 19c are opened are bored in the air sensor heads 19, at the opposed faces of the groove parts to the milling tools 17. An air pressure detector 21 is provided at the intermediate part of an air supply pipe 20 to the air passages 19b. When the cutting edge part 17b of the milling tool 17 is chipped from the thin wall part 17a, a large quantity of air is jetted from the nozzle, and air pressure in the supply pipe is lowered to the set value or less. The air pressure detector 21 detects this and sends a chipping signal to an NC system 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damage detecting device for one or more thin metal milling tools such as a metal saw mounted on a rotatable cutter arbor of a milling machine.

[0002]

2. Description of the Related Art Conventionally, a milling tool (metal saw) having a thin cutter width, which is used for grooving and slitting, is relatively easy to be damaged. Therefore, cutting work using this kind of tool is also monitored by an operator. It is usually done at and.

[0003]

The method of cutting under the supervision of an operator described in the prior art is contrary to the need for labor saving, and especially in mass production, unmanned operation for a long time leads to cost reduction. In order to realize the above, it is indispensable to detect the loss of the milling tool. The present invention has been made in view of such problems of the conventional technology,
The object of the invention is to provide a device for detecting a defect in a thin milling tool, which is an obstacle to manpower saving and unmanned operation.

[0004]

In order to achieve the above object, a milling tool loss detecting device according to the present invention is a loss detecting device for one or more thin milling tools attached to a rotatable cutter arbor of a milling machine. In addition, a thin portion formed of an annular groove is provided on at least one side surface closer to the center than the blade portion on the side surface of the milling tool, and a small gap is provided in the center portion between the blade portion on both side surfaces of the milling tool and the thin portion. The number of the air sensor heads having the groove portions facing each other and the nozzles opening on the facing surfaces of the groove portions, and the air flow passages for supplying air to the air sensor heads are provided. An air pressure detector that outputs a signal when the pressure becomes equal to or lower than a set pressure is provided to detect a defect of a blade portion including a thin portion of the milling tool.

[0005]

Operation: Pressure air is supplied to the air flow path, a small amount of air is ejected from the nozzle of the air sensor head, and cutting is performed while monitoring the air pressure in the air flow path with an air pressure detector. When the milling tool is damaged by some external pressure during cutting, the blade part including the thin part is broken and missing, a large amount of air is ejected from the nozzle, and the air pressure in the air flow path becomes less than the set value. A defect detection signal is output from the pressure detector.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the portal milling machine of FIG. 1, a table 1 is installed on the floor, two X-axis guides 2 are arranged in parallel on both floors, and a column 3 is mounted on the X-axis guide 2 so as to be movable and positioned. A cross rail 4 is fixedly mounted on the column 3. The cross rail 4 has a guide in the Y-axis direction, a saddle 5 is movably provided on the Y-axis guide, and a spindle head 6 is provided on the Z-axis guide of the saddle 5 so that the spindle head 6 can be moved and positioned.

A tool base 7 is detachably fixed to the spindle head 6. As shown in FIGS. 2 and 3, the tool base 7 has a bearing 11 at the rear end of the cutter arbor 9 that faces the Y-axis direction on the tool base body 8.
The cutter arbor 9 is rotatably supported via a supporter 12 fixed to the main body 8 so as to be movable in the Y-axis direction.
Is rotatably supported by a bearing 13. A gear 14 is fitted on the rear end of the cutter arbor 9, and the main body 8
An intermediate gear 15 rotatably mounted on the gear is meshed with the gear 14. The intermediate gear 15 is meshed with a drive gear 16 in the spindle head 6 which is rotated by a motor (not shown).

A thin milling tool (metal saw) 17 for machining fine grooves or slits is concentrically attached to the cutter arbor 9 with a plurality of collars 18 at intervals. The metal saw 17 is provided on its side surface with a thin-walled portion 17a composed of an annular groove carved from both sides closer to the center than the blade portion 17b, and the blade portion including the thin-walled portion 17a is prevented from being damaged by an unexpected external pressure during cutting. It has a structure in which 17b is deleted.

The same number of air sensor heads 19 as the metal saw 17 are fixed to the main body 8, and the outer peripheral portion of the metal saw 17 is fitted in the groove portion 19a of the air sensor head 19. The groove portion 19a is provided with recesses on three surfaces corresponding to the blade portion 17b, and the flat surfaces of the central portions of the blade portion 17b and the thin portion 17a face the groove portion 19a with a slight gap. Further, an air flow path 19b is formed in the air sensor head 19, a nozzle 19c is opened in a surface facing the metal saw 17, and an air flow path 19b is formed in the main body 8.
An air flow path 8a that communicates with is provided.

Pressure air is supplied from an external air source P to the air flow path 8a.
An air pressure detector 21 is attached in the middle of 0. The air pressure detector 21 outputs N when the air pressure falls below the set pressure.
The signal is output to the C device 22.

Next, the operation of this embodiment will be described.
The cutter arbor 9 is rotated through the gears 16, 15, and 14 to rotate the plurality of metal saws 17, and the work W mounted on the table 1 is cut. During this time, a small amount of air is ejected from the nozzle 19c opening on the surface of the air sensor head 19 facing the metal saw 17.

The facing surface between the metal saw 17 and the groove portion 19a of the air sensor head has only a small gap required for rotation, and a small amount of air is ejected from the nozzle 19c, but the thin portion 17a of the metal saw 17 is caused by an unexpected external pressure. Blade part 1 including
If 7b is damaged and missing, a large amount of air will suddenly be ejected from the nozzle 19c, and the air pressure in the air supply pipe 20 will drop below a set value. This pressure drop is detected by the air pressure detector 21, and a signal is output to the NC device 22. N
Upon receiving this signal, the C device 22 makes an emergency stop of the machine and informs the operator of the tool breakage by a patrol lamp or a buzzer.

[0013]

Since the present invention is configured as described above, it has the following effects. A small amount of air is ejected from the nozzle of the air sensor head that opens on the opposite side of the narrow milling tool attached to the cutter arbor to perform cutting, and the blade part is damaged and missing from the thin part of the milling tool. When a large amount of air is ejected from the nozzle and the pressure in the air flow path drops below the set value, a defect detection signal is output, so a signal is output immediately when one of many milling tools is missing. It is possible to stop the machine in an emergency, and it is possible to perform unmanned operation for a long time such as slitting using a thin milling tool with a high damage rate.

[Brief description of drawings]

FIG. 1 is an external view of a portal milling machine according to this embodiment.
Is a front view and (b) is a side view.

FIG. 2 is a diagram showing a cross section of a tool base and a tool loss detection device of the present embodiment.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 table 3 column 4 cross rail 5 saddle 6 spindle head 7 tool rest 8 tool rest body 8a, 19b air flow passage 9 cutter arbor 17 milling tool 17a thin portion 17b blade portion 19 air sensor head 19a groove portion 19b air flow passage 19c nozzle 20 air Supply pipe 21 Air pressure detector

Claims (1)

[Claims] 1. A defect detection device for one or more thin milling tools attached to a rotatable cutter arbor of a milling machine, wherein a thin-walled portion formed of an annular groove is located closer to the center than the blade portion on the side surface of the milling tool. The air sensor head is provided on at least one side surface, and has a groove portion facing each other with a small gap in a central portion between the blade portion on both sides of the milling tool and the thin portion, and a nozzle is opened on the facing surface of the groove portion. The number of milling tools is provided, an air flow path for supplying air to the air sensor head is provided, and an air pressure detector that outputs a signal when the air pressure in the air flow path becomes equal to or lower than a set pressure is provided. A defect detecting device for a milling tool, which detects a defect in a blade portion including a thin portion of the milling tool.