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Wire electron discharge machine for small diameter tools
P#tCl '$ System for measuring wear on diamond honing sticks The degree of wear on diamond and CBN honing sticks can be measured with a system recently developed by Kadia-Diamant. In the method, a fluorescent material is deposited between the abrasive layer and the steel blank and this gradually becomes exposed as the abrasive layer wears away. A photo-electric sensor system connected to the honing machine detects the presence of this fluorescent layer and this can be used to give an accurate on-going measurement of tool wear. The Kadia-Diamant system was developed with the following basic principles: •
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it can be used on any existing honing machine regardless of in-feed system it does not rely on empirically established wear rates it is independent of the accuracy of the thickness of the cutting layer it is independent of any variation in the hardness of either the tool or workpiece material
The fluorescent material is incorporated into the adhesive layer which bonds the diamond or CBN abrasive to the steel blank of the honing stick. It is a non-toxic, inorganic, silicate-based compound, which emits a high wavelength beam when excited through an ultra-violet spectrum. This property, whereby
light is absorbed and emitted selectively, is used to detect the adhesive layer as it becomes exposed. The sensor apparatus connected to the honing machine is designed to detect fluorescence on engineering surfaces by transmitting a beam of light directly at the honing stick during honing operations. The transmitted light is detected through a system of lenses and filters connected to a photodiode, which converts the optical signal into an electrical voltage. The light which is then emitted from the surface of the honing stick is detected with a similar system of filters and lenses leading to a separate photodiode. The two converted voltages are fed from the photodiodes directly into a quotient former, which calculates the quotient voltage between the two signals. The filters used in the sensor are carefully chosen to eliminate the effect that honing oils have on the measured signal. As the fluorescent material becomes exposed, it transforms the wavelength of the emitted light and thus affects the quotient voltage. A computer-controlled evaluation unit receives this quotient voltage and displays one of three messages to the operator: ' Good', ' Critical ", or ' Bad'. When the 'Bad' condition is displayed, the unit automatically shuts down the honing machine. De Beers Industrial Diamond Division, Charters, Sunninghill, Ascot, Berkshire SL5 9PX, UK
Wire electron discharge machine for small diameter tools Jointly developed by Toray Industries and Toray Precision Company, the wire electron discharge machine, the TMH-101, can form extra fine, round holes having diameters of less than 10/~m. The machine is an industrial application of a wire electron discharge grinding technique developed by the Masuzawa Research Group. With this technique, the grinding material for producing the tool is changed into wire form and grinding is achieved while continuously feeding the wire vertically toward the tool electrode, so the distance between the electrodes remains constant. As a result, it is possible to form extra-fine tools having diameters of less than 5/~m. The cross-sectional areas of the tools are close to perfect roundness, and the gap between the electrodes need not be remeasured from time to time during the machining process, so work time is shortened. The machine enables product accuracies to be improved in the sectors of microengineering and optical equipment fabrication. For example, the tools produced can also be used as the shafts of precision equipment or as components for manufacturing precision measuring equipment. Toray Industries Inc, 2-1 Nihonbashi Muromachi 2-chome, Chuo-ku, Tokyo, Japan
STM has built-in SEM
A photoelectric sensor can monitor hone wear automatically during the honing operation
250
A scanning tunelling microscope (STM) with a built-in scanning electron microscope (SEM) which can be used to observe a sample in ultra-high vacuum conditions, has been developed by Hitachi. Using the system it is claimed to be possible to obtain reproducible and reliable STM images owing to (1) continuous observation with a broad range of magnifications from some 10 to 100 million, (2) multifaceted evaluation of materials by the STM, SEM, STS (scanning tunnelling spectroscopy), and RHEED
OCTOBER 1989 VOL 11 NO 4
• •
•
it can be used on any existing honing machine regardless of in-feed system it does not rely on empirically established wear rates it is independent of the accuracy of the thickness of the cutting layer it is independent of any variation in the hardness of either the tool or workpiece material
The fluorescent material is incorporated into the adhesive layer which bonds the diamond or CBN abrasive to the steel blank of the honing stick. It is a non-toxic, inorganic, silicate-based compound, which emits a high wavelength beam when excited through an ultra-violet spectrum. This property, whereby
light is absorbed and emitted selectively, is used to detect the adhesive layer as it becomes exposed. The sensor apparatus connected to the honing machine is designed to detect fluorescence on engineering surfaces by transmitting a beam of light directly at the honing stick during honing operations. The transmitted light is detected through a system of lenses and filters connected to a photodiode, which converts the optical signal into an electrical voltage. The light which is then emitted from the surface of the honing stick is detected with a similar system of filters and lenses leading to a separate photodiode. The two converted voltages are fed from the photodiodes directly into a quotient former, which calculates the quotient voltage between the two signals. The filters used in the sensor are carefully chosen to eliminate the effect that honing oils have on the measured signal. As the fluorescent material becomes exposed, it transforms the wavelength of the emitted light and thus affects the quotient voltage. A computer-controlled evaluation unit receives this quotient voltage and displays one of three messages to the operator: ' Good', ' Critical ", or ' Bad'. When the 'Bad' condition is displayed, the unit automatically shuts down the honing machine. De Beers Industrial Diamond Division, Charters, Sunninghill, Ascot, Berkshire SL5 9PX, UK
Wire electron discharge machine for small diameter tools Jointly developed by Toray Industries and Toray Precision Company, the wire electron discharge machine, the TMH-101, can form extra fine, round holes having diameters of less than 10/~m. The machine is an industrial application of a wire electron discharge grinding technique developed by the Masuzawa Research Group. With this technique, the grinding material for producing the tool is changed into wire form and grinding is achieved while continuously feeding the wire vertically toward the tool electrode, so the distance between the electrodes remains constant. As a result, it is possible to form extra-fine tools having diameters of less than 5/~m. The cross-sectional areas of the tools are close to perfect roundness, and the gap between the electrodes need not be remeasured from time to time during the machining process, so work time is shortened. The machine enables product accuracies to be improved in the sectors of microengineering and optical equipment fabrication. For example, the tools produced can also be used as the shafts of precision equipment or as components for manufacturing precision measuring equipment. Toray Industries Inc, 2-1 Nihonbashi Muromachi 2-chome, Chuo-ku, Tokyo, Japan
STM has built-in SEM
A photoelectric sensor can monitor hone wear automatically during the honing operation
250
A scanning tunelling microscope (STM) with a built-in scanning electron microscope (SEM) which can be used to observe a sample in ultra-high vacuum conditions, has been developed by Hitachi. Using the system it is claimed to be possible to obtain reproducible and reliable STM images owing to (1) continuous observation with a broad range of magnifications from some 10 to 100 million, (2) multifaceted evaluation of materials by the STM, SEM, STS (scanning tunnelling spectroscopy), and RHEED
OCTOBER 1989 VOL 11 NO 4