Abrading – Abrading process – With tool treating or forming
Reexamination Certificate
1997-06-16
2001-06-19
Morgan, Eileen P. (Department: 3723)
Abrading
Abrading process
With tool treating or forming
C451S443000, C451S070000, C451S324000, C451S173000
Reexamination Certificate
active
06248003
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for truing a grinding wheel, that is, reshaping the grinding wheel or compensating for asymmetric wear of the grinding wheel, and a device used to perform such a method.
2. Description of the Prior Art
A so-called “super grinding wheel,” which contains diamond particles, CBN (cubic boron nitride) particles or similar particles as the abrasive grain, is well known in the grinding industry. In recent years, workpieces have become more difficult to grind, because various types of abrasion resistive materials have become widely used in many industries. In addition, there are strong demands to increase the dimensional precision and the grinding efficiency of the workpieces. As a result, the use of such a super grinding wheel has rapidly grown.
Conventional methods for truing the super grinding wheel may involve (1) utilizing a diamond tool, such as a single diamond dresser, a diamond impregnated dresser and a block dresser, (2) utilizing a block-like grindstone or a rotary grindstone made of GC (SiC), WA (AL
2
O
3
) and similar materials, and (3) utilizing a tool made of mild steel (which will be referred to as a “mild steel grinding method”).
However, method (1) requires a lengthy dressing operation to restore the grinding power of the grinding wheel that must be performed after the truing operation is completed, because the abrasive grain particles protruding from the treatment surface of grinding wheel are worn during the truing operation, such that the tip of each abrasive grain particle is substantially flattened. This may lower the efficiency of the truing operation and decrease the precision of the trued grinding wheel. In addition, this method may cause the truing tool to wear rapidly, thus resulting in increased truing costs.
Further, each of methods (2) and (3) does not provide sufficient truing power. Therefore, it may take a long time to true the grinding wheel.
Moreover, conventional methods for truing the super grinding wheel also involve (4) utilizing a brake truer, such as a rotary dresser, a diamond wheel and other rotary tools, (5) a lapping method utilizing uncombined or free abrasive particles, (6) a crush roller method in which a rotating cylindrical metal is pressed against the grinding wheel to be treated, and (7) an electrical or non-contact method utilizing an electrical discharge.
Each of methods (4) to (7), when applied to the super grinding wheel, also does not provide satisfactory truing capability. Also, each of these methods has a limited range of application. Thus, such methods are not suitable for application to various types of grinding machines (including double-disk grinding machines or special purpose grinding machines). Further, such methods cannot be applied to various types of super grinding wheels in which the abrasive grain particles are combined using different types of binding agents.
SUMMARY OF THE INVENTION
Therefore, it is desired to provide a method that may speedily and easily true a super grinding wheel at a relatively lower cost and may be applied to various types of grinding machines. Further, it is preferable that the method can be performed in situ, that is, without detaching the grinding wheel to be trued from the grinding machine and does not require an additional operation to dress the grinding wheel.
The present inventors have studied the truing mechanism of the conventional mild steel grinding method. Consequently, it has been found that in order to true the super grinding wheel with high efficiency, the binding agent for the abrasive grain particles of the super grinding wheel must be effectively removed during the truing operation. They have further studied and discovered that, in order to effectively remove the binding agent, it is necessary to induce a solid phase diffusion reaction or other chemical reactions between the binding agent of the super grinding wheel and the truing device material. Moreover, it has been found as a result of additional tests that metals located in groups IVA, VA and VIA of the periodic table or alloys thereof may exhibit excellent truing capability for the super grinding wheel.
It is an object of the invention to eliminate the problems associated with the conventional methods, that is, to provide an improved method of truing a grinding wheel with high efficiency and a device used in performing such a method.
In order to attain this object, the present invention provides a method for truing a grinding wheel including the steps of providing a material containing a metallic material selected from the group consisting of metals in groups IVA, VA and VIA of the periodic table and alloys thereof, rotating a grinding wheel having a treatment surface to be trued, and grinding the metallic material with the treatment surface of the grinding wheel.
According to the present method, a binding agent contained in the grinding wheel and the metallic material selected from the group consisting of metals in groups IVA, VA and VIA of the periodic table may react to induce a solid phase diffusion reaction and other chemical reactions on the treatment surface of the grinding wheel, thereby forming a brittle compound. The brittle compound may be easily removed from the treatment surface of the grinding wheel during the truing operation. Further, a portion of the binding agent of the grinding wheel can be mechanically removed from the treatment surface.
Therefore, the present method may true various types of grinding wheels with high efficiency. Further, the present method does not require an additional dressing operation after the grinding wheel has been trued. This may lead to decreased truing costs and decreased truing time.
The present invention will become more fully apparent from the claims and the description as it proceeds in connection with the drawings.
REFERENCES:
patent: 4020820 (1977-05-01), Kish
patent: 4555873 (1985-12-01), Smith
patent: 2438600 (1976-02-01), None
patent: 3718622 (1988-12-01), None
patent: 0433829A2 (1991-06-01), None
patent: 07053260 (1996-08-01), None
patent: 2044146 (1980-10-01), None
Hoshiya Kiyoharu
Kohsaka Shinji
Morgan Eileen P.
Patterson Thuente Skaar & Christensen P.A.
San-ei Seiko Co., Ltd.
LandOfFree
Method of truing grinding wheel and device used in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of truing grinding wheel and device used in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of truing grinding wheel and device used in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2505010