JPH0440837Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use The present invention is applicable to the following: When one of the many rotating tools attached to the multi-axis head of a machine tool is in an abnormal state such as being damaged or broken during machining work, The present invention relates to an ultrasonic vibration extraction device for detecting this.

Conventional technology In recent years, with the advancement of production technology, the demand for labor-saving and unmanned cutting processes has rapidly increased. In-process detection of states is an important issue.

Ultrasonic vibrations, including acoustic emissions (AE) caused by tool damage, breakage, or other overload, are one of the effective methods for in-process detection of abnormal conditions such as cutting tool damage or breakage. A tool breakage prevention device is known that is configured to detect a detection signal and perform an appropriate tool protection operation in order to prevent damage or breakage of the tool or to reduce the occurrence of overload (for example, , see Japanese Patent Publication No. 58-186550 and Japanese Patent Publication No. 61-21764).

Purpose of the invention The purpose of the invention is to provide a device for effectively detecting ultrasonic vibrations including AE from a large number of rotating tools attached to a multi-axis head when the above-mentioned tool breakage prevention device is applied to a multi-axis head. Our goal is to provide the following.

Structure of the Invention In order to achieve the above object, the ultrasonic vibration extraction device of the present invention has a number of fitting holes through which a number of tool rotating shafts attached to a multi-axis head individually pass through, and An ultrasonic sensor is attached to a vibration extraction plate that is provided with liquid channels that communicate with each other and a liquid supply port that supplies liquid to the liquid flow paths, and the vibration extraction plate is attached to each of the fitting holes. The tool is fixedly arranged in a position that forms a slight annular gap between the outer circumferential surface of the tool rotating shaft that has passed through the tool and the inner circumferential surface of the fitting hole, and the liquid supplied through the liquid flow path fills the annular gap. The ultrasonic vibration generated in the rotary tool mounted on the rotary tool or the tool rotary shaft interlocked therewith is transmitted to the vibration extraction plate through the liquid film, and is detected by the ultrasonic sensor. It is characterized by being designed to be detected.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

1 is a spindle head of a machine tool, and 2 is a main body of a multi-spindle head, on the front of which a number of tool rotating shafts 3 are supported in parallel to each other via bearing cases 4. The main body 2 is attached to the tip of the spindle head 1, and the rotational force of the main spindle is transmitted to each tool rotating shaft 3 via a transmission gear mechanism 5 built into the main body 2.
A rotary tool 7 such as a drill or a screw tap is attached to each tool rotating shaft 3 via a tool holder 6.

The tool holder 6 is provided with an ultrasonic vibration transmitting device 8 at a rear end portion that is inserted into the mounting hole of the tool rotating shaft 3. The ultrasonic vibration transmitting device 8 is a rotary tool 7
It includes a torque limiter that operates when an overload is applied to the torque limiter, and is configured to generate high frequency elastic vibrations including ultrasonic waves in conjunction with the operation of the torque limiter. Patent Application No. 57-201367 developed by
21764) is preferred.

Reference numeral 10 denotes a vibration extraction plate, which has a large number of fitting holes 11 through which each tool rotating shaft 3 of the multi-axis head passes individually.
and a liquid flow path 12 that communicates the fitting hole 11 with each other.
and a liquid supply port 1 for supplying cutting oil to the liquid flow path 12.
3, and an ultrasonic sensor 14 is attached to the lower part of the vibration extraction plate 10.

The vibration extraction plate 10 is attached and fixed to the multi-axis head main body 1 via a support rod 15 in a posture such that each tool rotation shaft 3 passes through each fitting hole 11, and the outer circumferential surface of the tool rotation shaft 3 and the fitting hole A small annular gap (approximately 0.2 to 0.4 mm) is formed between the annular gap 16 and the inner peripheral surface of the gap 11. 17 in the figure is fitting hole 1
This is a seal ring fitted on one side end of the 1.

Function: Each tool rotating shaft 3 of the multi-axis head rotates, and cutting is performed with the rotating tool 7 that rotates in conjunction with this, which is the same as the conventional device, but at this time, cutting oil is supplied from the fluid supply port 13. is continuously supplied, and the cutting oil is caused to flow into the annular gap 16 of each fitting hole 11 through the flow path 12. The cutting oil that has entered the annular gap 16 gradually flows out from the open front side of the fitting hole 11, but it constantly fills the annular gap 16 and forms a thin oil film in the annular gap 16.

Therefore, when an overload is applied to any of the rotary tools 7 during cutting by the rotary tools 7, the ultrasonic transmitter 8 including a torque limiter built into the rear end of the tool holder 6 is activated to generate ultrasonic vibrations. do. Note that ultrasonic vibrations are also generated when the rotary tool 7 is broken, comes into contact with another object, or is seriously damaged. These ultrasonic vibrations are transmitted from the tool rotation shaft 3 to the vibration extraction plate 10 through the oil film in the annular gap 16, and are transmitted to the vibration extraction plate 10 from the tool rotation shaft 3.
Detected by 4. At this time, since the vibration is transmitted from the rotating tool rotation shaft 3 to the vibration extraction plate 10 fixed to the main body 2 through the oil film in the annular gap 16, almost no damping occurs. Therefore, each rotary tool 7
Alternatively, the ultrasonic vibrations generated from the ultrasonic generator 8 linked thereto are reliably detected by the ultrasonic sensor 14.

In this way, an abnormal state of the rotary tool 7 is detected by the ultrasonic vibration detected by the ultrasonic sensor 14,
This signal is used to perform appropriate tool protection operations. For example, at the same time as stopping the rotation of the tool rotation shaft 3, the rotary tool 7 is separated from the workpiece.

In the above embodiment, cutting oil was supplied to the annular gap 16 to form an oil film, but instead of cutting oil, water or other liquid was supplied to the annular gap 16, and ultrasonic vibrations were transmitted through the liquid film. You may do so.

Effects of the invention Since the present invention has the above-mentioned configuration, it is possible to avoid damage to any of the many rotating tools rotated by the many tool rotating shafts attached to the multi-axis head.
When an abnormal condition such as breakage occurs, it can be immediately and reliably detected by the ultrasonic sensor. Moreover, the device is simple and easy to handle.
It is extremely effective as a detection means in a multi-axis head tool breakage prevention device.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal side view of a main part of a machine tool equipped with an ultrasonic vibration extraction device according to the present invention, and FIG. 2 is a front view of the main part of the same device. 1...Spindle head, 2...Multi-axis head body, 3...
Tool rotating shaft, 4... Bearing case, 6... Tool holder, 7... Rotating tool, 8... Ultrasonic vibration transmitter, 10... Vibration extraction plate, 11... Fitting hole, 1
2...Liquid channel, 13...Liquid supply port, 14...Ultrasonic sensor, 16...Annular gap, 17...Seal ring.

Claims (1)

[Claims for Utility Model Registration] A number of fitting holes through which a number of tool rotating shafts attached to a multi-axis head are individually passed, a liquid flow path that communicates with each other through the fitting holes, and a liquid flow path that communicates with each other. An ultrasonic sensor is attached to a vibration take-off plate equipped with a liquid supply port for supplying liquid to the vibration take-off plate, and the vibration take-off plate is connected to the outer circumferential surface of the tool rotation shaft passing through each of the fitting holes and the fitting hole. The tool is fixedly arranged in a position that forms a slight annular gap with the inner circumferential surface of the matching hole, and the liquid supplied through the liquid flow path forms a liquid film in the annular gap, and the tool rotates through the tool rotation axis. The multi-axis head is configured such that ultrasonic vibrations generated in the attached rotary tool or the tool rotating shaft interlocked therewith are transmitted to the vibration extraction plate through the liquid film and detected by the ultrasonic sensor. A device that extracts ultrasonic vibrations from the tool rotation axis.