JPH11285971A - Non-contact dressing truing method and apparatus for grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct a continous grinding and shoten a total grinding time by fusing and vaporizing a binding agent at a using surface or an auxiliary using surface of a grinding wheel that is required being subjected to dressing or truing, and controlling the projection quantity of abrasive grains and the contour of the grinding wheel. SOLUTION: This apparatus comprises a device enabling an operator to observe change in a using surface 2a and an auxiary using surface 2b of a grinding wheel when dressing or truing is applied thereto, and a mechanism for feeding back the observation information of the surfaces 2a, 2b to a laser oscillator 3. Considering the thermal and optical characteristics of abrasive grains and a hinder, a laser whose oscillation wavelength, maximum output, maximum pulse energy, power concentration, pulse width and the like are used to dress or true the grinding wheel. Topography information of the surfaces 2a, 2b changing moment by momnt by the dressing or truing operation is used for determinating optimum conditions of dressing and truing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for non-contact dressing and truing of a grindstone using a laser. In the present invention, the "use surface" of the whetstone,
“Auxiliary use surface” is used in a meaning commonly used in the art (see JIS R6211).
The working surface of the whetstone is intentionally brought into contact with the workpiece, the surface on which the workpiece is ground, and the "auxiliary working surface" is the result of the grinding process in order to finish the grinding surface to the intended shape. It is used to mean a surface that comes into contact with an object.

[0002]

2. Description of the Related Art JIS B 4134, B 4135, B
References 4136 and B 4137 describe a single diamond dresser, a diamond implied dresser, a diamond chisel dresser, and a diamond point dresser, respectively. These are all mounted so as to be in contact with the grindstone, and turn, grind and dress the grindstone. Huntington Dresser, Met Cuff Dresser, Mechanic Dresser (Akira Wakuri, "Key Techniques", published by Yokendo Co., Ltd., pp
259-260) are also mounted so as to be in contact with the grindstone, and turn and dress the grindstone.

[0003] When using any of the above prior arts, it is necessary to remove the workpiece from the grinder, install the dresser,
Perform positioning, dressing or truing,
It is necessary to go through a series of steps such as removal of the dresser, re-attachment and positioning of the workpiece, etc., and there is a problem that the total grinding time is promoted and machining accuracy is deteriorated due to the attachment / removal of the workpiece. As described above, the dressing / truing method of the grinding wheel is conventionally of a contact type, so that unintended consumption and detachment of abrasive grains and consumption of a binder are involved, and the short life of the grinding wheel is a problem. Further, with regard to Prior Art 1, there is a problem that the diamond is loosened or dropped at the diamond attachment portion. Since it is a contact type, there is a drawback that a thin blade whetstone having low rigidity is deformed or cracked.

[0004]

SUMMARY OF THE INVENTION The present invention has the problems that the conventional dressing and truing are of the contact type (such as shortening of the life of the grinding wheel due to wear and tear of the grinding wheel, consumption of the binder, etc., and installation of the dresser). Using a laser to solve problems such as the increase in total grinding time and the inability to deal with dressing and truing of low-rigidity grindstones caused by a series of processes such as removal, removal of workpieces, and repositioning. Further, it is an object of the present invention to provide a method and an apparatus capable of shortening the total grinding time, improving the processing accuracy, increasing the life of the grinding wheel, and adapting to a low-rigidity grinding wheel.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for melting and evaporating a binder on a use surface or an auxiliary use surface of a grindstone requiring dressing or truing, thereby removing an abrasive grain,
The gist of the present invention is a non-contact dressing / truing method of a grindstone, which is characterized by controlling the contour of the grindstone. The non-contact dressing and truing method of the present invention is characterized in that it corresponds to a low-rigidity grindstone. Further, the non-contact dressing truing method of the grinding wheel of the present invention is characterized by continuous grinding without temporary stop of the grinding wheel related to the dressing truing. Melting and evaporating the binder on the working surface or the auxiliary working surface of the grindstone and controlling the amount of abrasive grains projected and the grindstone contour are performed by laser irradiation from a laser oscillator. In this case, the dressing and truing optimum conditions are determined based on the topography information of the whetstone use surface and the auxiliary use surface, and are then fed back to the laser oscillator. The whetstone-use surface and the auxiliary use surface are observed with a portable confocal microscope or the like, and the surface topography information is used for determining optimal dressing / truing conditions, and the conditions are fed back to the laser oscillator.

[0006] The non-contact dressing / truing method of a grinding stone according to the present invention uses a laser having a wavelength other than the wavelength at which infrared and ultraviolet absorption and selective impurity absorption occur when the abrasive has a light transmitting property. Is characterized by not damaging the abrasive grains. The present invention also provides an apparatus for performing the above-described method, comprising at least one or more laser oscillators and a machine tool for grinding a workpiece using a grindstone. The gist is a non-contact dressing / truing device for grinding wheels. Still further, the present invention provides an apparatus for performing the above method, comprising one or more laser oscillators, a machine tool for grinding a workpiece using a grindstone,
Grinding fluid and grinding fluid supply mechanism, grindstone that requires dressing or truing, device that enables observation of changes in grindstone used surface and auxiliary used surface by dressing and truing, and information on observation of grindstone used surface and auxiliary used surface to laser oscillator The gist of the present invention is a non-contact dressing and truing device for a grindstone, which is provided with at least a feedback mechanism.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The method for non-contact dressing and truing of a grindstone according to the present invention is based on the thermal and optical characteristics of abrasive grains and a binder,
It is characterized by dressing and truing the grindstone using a laser whose maximum pulse energy, power density, pulse width, etc. are selected. In addition, dressing
It is also characterized in that the topography information of the whetstone-use surface and the auxiliary use surface, which is constantly changing due to truing, is used to determine the optimum conditions for dressing and truing.

[0008] An apparatus for realizing the above method requires one or more laser oscillators, a machine tool for grinding a workpiece using a grindstone, a grinding fluid and a grinding fluid supply mechanism, and dressing or truing. A grinding wheel, a device that enables observation of changes in the grinding wheel use surface and the auxiliary use surface by dressing and truing, and a mechanism that feeds back information on the grindstone use surface and the auxiliary use surface observation to the laser oscillator.

There are various types of lasers depending on the type of laser medium, but there is no limitation. It is desirable that the laser oscillator has a variable oscillation wavelength, maximum output, maximum pulse energy, power density, pulse width, etc.If there is a laser oscillator that can supply a laser according to the thermal and optical characteristics of abrasive grains and binders Good.

A machine tool for grinding a workpiece using a grindstone includes various types of grinders (a grinder, a cylindrical grinder, an angular slide grinder, a universal grinder, an inner grinder, etc.) specified in JIS B 0105. Surface grinders, square table type surface grinders, rotary table type surface grinders, opposed two-axis surface grinders, centerless grinders, profile grinders, numerical control grinders), but not limited to these. Absent.

In the present invention, the target grindstone is a metal bond grindstone or a ceramic bond grindstone. In particular, a low rigidity grindstone is a grindstone having low rigidity due to its shape, structure, material, and the like, such as a thin blade grindstone used for applications such as silicon wafer cutting. The grindstone refers to a rotating body composed of innumerable abrasive grains, a binder and pores, or an element composed of three of them being attached to the rotating body. The grindstones are classified by items such as types of abrasive grains, abrasive grain size, degree of bonding, structure, type of binder, shape, edge, outer shape, inner diameter, thickness, and the like, but are not limited thereto. The grindstone has numerous abrasive grains (particles of a hard material such as diamond), binders (metal, resin, glass, rubber, etc.) and pores (intervening in the grindstone intentionally or unintentionally during the manufacturing process) Vacancy). If it is hardened into a rotating body, it can be used as a whetstone. I also use it with axes for convenience. In addition, a mass formed by the above three elements may be joined to the substrate of the rotating body by some method to form a grindstone.

The grinding fluid used for dressing and truing includes, but is not limited to, water. Dressing and truing without using a grinding fluid is also included.

[0013] An apparatus that enables observation of changes in the whetstone use surface and the auxiliary use surface by dressing truing includes:
The use of a portable confocal laser microscope is desirable for performance reasons mainly including resolution and freedom of movement, but the present invention is not limited to this and includes visual observation.

As a mechanism for feeding back the observation information of the whetstone use surface and the auxiliary use surface to the laser oscillator, a mechanism having an information processing device such as an electronic computer at the center thereof is generally used. The method is not limited to this, and any method may be used as long as it has a sufficient function for determining the optimum conditions for dressing and truing.

[0015]

The operation of the present invention will be described. Since it is a non-contact type, there is no physical deterioration or wear of the dresser. Also, there is no shift in the dresser position due to the reaction force from the grindstone. Since it is a non-contact type, dressing and truing of a low-rigidity grindstone is possible without deformation and cracking of the grindstone.

From the melting point and boiling point of the binder, the binder is melted,
Select the maximum power, maximum pulse energy, power density, pulse width, etc. of the laser required to evaporate. By irradiating the laser on the whetstone use surface or the auxiliary use surface, the binder is melted and evaporated, so that the amount of abrasive grains projected can be controlled. If the abrasive grains are translucent, such as diamond, use a laser having a wavelength other than the wavelength at which infrared / ultraviolet absorption and selective absorption by impurities occur, so that dressing can be performed without damaging the abrasive grains. Truing is possible.

The laser is applied to the grindstone from a position different from the relative position between the grindstone and the workpiece. Therefore, there is no need to move the workpiece during dressing and truing, and it is possible to prevent the accompanying increase in the total grinding time and the deterioration of the processing accuracy.

The observation of the whetstone use surface and the auxiliary use surface is performed either when the grindstone is stopped or when the whetstone is rotated, and information such as the protrusion amount of the abrasive grains and the whetstone contour is obtained. Based on that information, determine the optimum conditions such as maximum laser output, maximum pulse energy, power density, pulse width, and irradiation time to obtain the desired amount of abrasive grain protrusion, and determine the laser irradiation position to obtain the desired grinding wheel contour. Becomes possible. The determined optimum condition is fed back to the laser oscillator.

When dressing and truing are performed periodically, it is not necessary to temporarily stop the rotation of the grindstone at the start of the dressing and truing, and continuous grinding can be performed on one workpiece until the processing is completed. When the workpiece is continuously supplied in the above range, continuous processing until the grindstone disappears becomes possible.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. The present invention is not limited by these examples.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the grindstone main body 1, the working surface 2a,
A cross-sectional view of the grinding wheel including the auxiliary use surface 2b is illustrated.
However, the grindstone is not limited to this shape. Dressing truing, observation of the surface is used surface 2a,
This is performed on the auxiliary use surface 2b. Reference numeral 3 denotes a laser oscillator, and one or more laser oscillators are prepared, but the type is not limited. The installation positions with respect to the use surface 2a and the auxiliary use surface 2b change as necessary. Reference numeral 4 denotes a portable confocal laser microscope, but observation of the use surface 2a and the auxiliary use surface 2b is not limited to this. Use surface 2a, auxiliary use surface 2
The installation position with respect to b changes as required, similarly to the laser oscillator. Reference numeral 5 denotes a mechanism for obtaining dressing and truing optimum conditions using surface observation information and then feeding them back to the laser oscillator.

Whetstone; Artificial diamond as abrasive grains and cast iron as binder Artificial diamond; Infrared absorption edge: 2 μm, UV absorption edge: 0.222 μm Cast iron; Melting point: 1,153 ° C., Boiling point: 2,900 ° C. Laser Oscillator: YAG laser-excited dye laser oscillator, oscillation wavelength: 532 nm, maximum output: 12 W, maximum pulse energy: 600 mJ, pulse width: 5-8 ns,
Maximum repetition rate: 20 Hz, beam diameter: 9.5 mm, power density: 2.7 × 10 ¹² W / cm ² A device that enables observation of changes in the whetstone use surface and auxiliary use surface; portable confocal laser microscope

Effect It was confirmed with a confocal laser microscope that the average protrusion amount of the particles before laser irradiation was 23 μm. It was confirmed that the average protrusion amount of the abrasive after one pulse irradiation was 28 μm, and the average protrusion amount of the abrasive after two pulse irradiation was 33 μm. Therefore, the amount of abrasive grains protruding can be controlled at 5 μm / pulse.

[0024]

According to the present invention, continuous grinding can be performed without stopping the grinding wheel related to dressing and truing, and the total grinding time can be reduced. It is possible to control the protrusion amount of the abrasive and the contour of the grinding stone to a desired amount and a consumable shape. In addition, dressing and truing of a low-rigidity grindstone such as a thin blade grindstone becomes possible.

[Brief description of the drawings]

FIG. 1 is a drawing showing an embodiment of the present invention.

[Explanation of symbols]

 1 Cross-sectional view of grinding wheel main body 2a Grinding wheel use surface 2b Grinding wheel auxiliary use surface 3 Laser oscillator 4 Portable confocal laser microscope 5 Feedback mechanism 6 Lens

Claims (8)

[Claims] 1. A binder for a working surface or an auxiliary working surface of a grindstone requiring dressing or truing is melted,
A non-contact dressing and truing method for grinding wheels, characterized by controlling the amount of abrasive grains projected and the grinding wheel profile by evaporation. 2. The non-contact dressing / truing method of a grinding wheel according to claim 1, which is intended for a low-rigidity grinding wheel. 3. The non-contact dressing and truing method of a grinding wheel according to claim 1, wherein continuous grinding is performed without temporary stopping of the grinding wheel relating to dressing and truing. 4. The non-contact dressing and truing method for a grinding wheel according to claim 1, wherein the control is performed by irradiating a laser from a laser oscillator. 5. The non-contact dressing and truing method of a grinding wheel according to claim 4, wherein after determining optimum dressing and truing conditions from the topography information of the whetstone use surface and the auxiliary use surface, the conditions are fed back to a laser oscillator. 6. When the abrasive has a light transmitting property, the abrasive is not damaged by using a laser having a wavelength other than a wavelength at which infrared / ultraviolet absorption and impurity selective absorption occur. 5. Non-contact dressing and truing method of grinding wheel of 5. 7. An apparatus for performing the method according to claim 1, comprising at least one or more laser oscillators and a machine tool for grinding a workpiece using a grindstone. Non-contact dressing and truing device for grinding wheels. 8. A grinding fluid and a grinding fluid supply mechanism,
Equipped with a grindstone that requires dressing or truing, a device that enables observation of changes in the grindstone used surface and the auxiliary used surface by dressing / truing, and a mechanism that feeds back the observation information of the grindstone used surface and the auxiliary used surface to the laser oscillator. A non-contact dressing / truing device for a grindstone according to claim 7.