JPH0323299B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grinding method for grinding a workpiece made of a magnetic material used for a magnetic head or the like by adhering it to a workpiece attachment plate.

[Conventional examples and their problems]

Today's continuous technological innovation is remarkable, and the development of cutting-edge technology has brought many excellent product groups to the market.

The development of computers, microcomputers, word processors, and other electronic devices using this type of magnetic material according to the present invention seems to be progressing rapidly, and the current situation is that the development of even more advanced applied technologies is being accelerated. .

For this reason, higher processing precision is required for the flatness and parallelism of magnetic materials such as ferrite used in the magnetic heads of these electronic devices.

Conventionally, in this type of grinding method, as shown in FIG. 2, a workpiece W made of a magnetic material is pasted on the workpiece pasting surface of a workpiece pasting plate A, and the back surface of the workpiece pasting plate A is attached to a magnetic chuck C or a vacuum cleaner. By placing the workpiece on a whip C or the like and adsorbing it, and rotating the chuck C, the workpiece attaching plate A and the workpiece W were rotated together and ground with a grinding wheel B installed nearby, but in this case, The reference surface for grinding the workpiece W is the upper surface of the chuck C, that is, the workpiece attachment plate A.
This is a method of grinding using the surface that is in close contact with the top surface of chuck C, which is the back side of the workpiece attachment surface, as a reference surface.In addition to maintaining the flatness of the chuck surface with high precision, the parallelism and absolute accuracy of the workpiece attachment plate itself is The machining accuracy of the workpiece is determined by including the dimensions.In other words, the machining error of the workpiece is constantly added to the machining error of the workpiece attachment plate during grinding.

As a countermeasure, the material of the workpiece attachment plate is made of steel, which has an appropriate thickness that makes it difficult to deform.
Although we try to reduce expansion and contraction as much as possible, the workpiece attachment plate may still change due to temperature differences during and after processing, or changes in the temperature of the air in the surrounding atmosphere, resulting in changes in the absolute dimensions of the thickness or parallelism. At the grinding reference surface on the chuck surface side of the workpiece attachment plate, changes in the workpiece attachment plate immediately add to the machining accuracy of the workpiece, causing a significant decrease in the machining accuracy of the workpiece.

For this purpose, the workpiece attaching plate is made of expensive steel material that does not easily deform or change, and is machined with high parallelism and flatness accuracy. However, when a large number of workpieces are required, one Due to the aforementioned temperature changes, there is a limit to the number of workpiece attachment plates that can be ground, so multiple workpiece attachment plates with the same degree of parallelism, flatness accuracy, and absolute dimensions are prepared and processed. It is technically very difficult to prepare multiple workpiece attachment plates with the same conditions, and it is also costly to prepare multiple workpiece attachment plates made of expensive, highly precisely machined steel.

In addition, if the machining dimensions of the workpiece are different, the workpiece attachment plate is replaced each time to match the dimensions, and after grinding is completed, the deformed workpiece attachment plate is polished to maintain parallelism, etc. Each time polishing is performed, the absolute thickness of the workpiece attachment plate becomes thinner by the amount of polishing, which poses problems such as difficulty in preparatory and post-processing.

[Purpose of the invention]

The present invention focuses on the above-mentioned reasons, and as a result of intensive research, it solves these problems at once, and also significantly improves the machining accuracy of magnetic material workpieces such as magnetic heads that require high precision. Furthermore, it is an object of the present invention to create and provide a grinding method that does not require management of the absolute dimensions of parallelism and thickness of the plate to which the workpiece is attached, and which can meet requests.

[Structure of the invention]

A slightly wide annular tip surface is formed at the tip of the work spindle, a workpiece is attached to the outer periphery of the work attachment surface of the work attachment plate, and a perfect circular hole with a tapered portion is formed on the other surface. , a center having a conical tip that moves forward and backward in the axial direction and rotates freely is provided, the tip of the center is inserted into the circular hole, and the tip and the tip surface form a workpiece sticking plate. A grinding wheel for grinding the grinding surface of the workpiece is provided nearby, thereby making the reference surface for grinding the workpiece attachment surface of the workpiece attachment plate.

[Explanation of Examples]

The grinding method of the present invention that achieves the above object will be explained below with reference to drawings of embodiments.

FIG. 1 is an overall schematic plan view of an embodiment for explaining the present invention, and FIG. 2 is a schematic explanatory diagram of the prior art.

The present invention provides a work W made of magnetic material such as a magnetic head.
In the method of grinding by attaching the workpiece to the workpiece attaching plate 1, a slightly wide annular tip surface that contacts the center side of the workpiece attaching surface 1a of the workpiece attaching plate 1 is attached to the tip of the workpiece spindle 2 that rotates under power. A workpiece W is pasted on the outer periphery of the workpiece pasting surface 1a of the workpiece pasting plate 1, and a perfect circular hole 1d having a tapered portion 1c is formed in the center of the other surface 1b. A center 3 is provided, which is formed into a conical tip tip 3a having a taper that matches the taper portion 1c of the perfect circular hole 1d, and moves forward and backward in the axial direction using air or the like and rotates freely. The taper of the center 3 is aligned with the taper portion 1c of the circular hole 1d, and the tip portion 3a of the center 3 is inserted.
and the tip surface 2a of the work spindle 2 to sandwich the work attachment plate 1, and the grinding wheel B for grinding the grinding surface of the work W is self-rotating and placed close to the grinding surface so that it can move forward and backward. Accordingly, the reference surface for grinding is the workpiece attachment surface 1a of the workpiece attachment plate 1.

That is, the method of grinding a workpiece W made of a magnetic material such as a magnetic head of the present invention by attaching it to a workpiece attaching plate 1 is as follows, as in the conventional example shown in FIG. The tip of the work spindle 2, which rotates with power from an electric motor, is formed into an annular tip surface 2a with a slight width, and the tip surface 2a is machined with high flatness accuracy. It is brought into contact with the center side of the workpiece pasting surface 1a of the workpiece pasting plate 1 to transmit rotational force to the workpiece pasting plate 1 and to hold the workpiece pasting plate 1 in close contact with the workpiece pasting plate 1, with this surface serving as a reference surface. .

The workpiece pasting plate 1 according to the present invention has a workpiece pasting surface 1a on which the workpiece W is pasted, which is machined with high flatness accuracy, and the workpiece pasting surface 1a on which the workpiece W is pasted is processed with high precision, and the tip surface 2a of the workpiece spindle 2 is
The workpiece W is attached to the outer periphery with wax or the like, and the other surface 1b does not need to be machined to high precision flatness and parallelism, and is machined as appropriate. A bottomed true circular hole 1d having a tapered portion 1c is formed vertically, and a taper that matches the tapered portion 1c of the circular hole 1d is formed in a conical tip portion 3a to allow free rotation. A center 3 is provided so as to be movable forward and backward by air pressure, hydraulic pressure, or a screw mechanism, and the center 3 is inserted by aligning the taper of the tip 3a of the center 3 with the taper part 1c of the circular hole 1d. The workpiece sticking plate 1 is positioned in a direction perpendicular to the axial direction of the workpiece sticking plate 1, and the central sides of both sides of the workpiece sticking plate 1 can be freely rotated by the tip tip 3a of the center 3 and the tip surface 2a of the workpiece spindle 2. By inputting power to the work spindle 2,
rotates, and the workpiece sticking plate 1 with the workpiece W stuck between it and the center 3 rotates, and a cup-shaped diamond grinding wheel B, etc., which rotates on its own and can advance and retreat, grinds the grinding surface of the workpiece W. It is a thing,
This is a grinding method in which the tip surface 2a of the workpiece spindle 2, that is, the workpiece attachment surface 1a of the workpiece attachment plate 1, is used as a reference surface.

〔Effect of the invention〕

In response to the current demand for higher precision in magnetic materials such as magnetic heads, the grinding method of the present invention minimizes the number of workpiece attachment plates, eliminates the need to limit the material to expensive steel, and reduces chucks. It is not necessary to process the flatness accuracy, the flatness accuracy of the back side of the workpiece attachment plate, the parallelism accuracy of the workpiece attachment plate, and the absolute dimensions with high precision, and it is stable regardless of temperature changes due to grinding with a grinding wheel or changes in outside air temperature. It is possible to obtain high-quality, high-precision grinding accuracy for magnetic materials, and only the surface to which the workpiece is attached needs to be maintained at a high level of flatness, and the amount of grinding of the workpiece is determined using the surface to which the workpiece is attached as a reference surface. The present invention is an epoch-making method for determining machining accuracy, and its contribution is immeasurable, and it has extremely significant effects.

[Brief explanation of drawings]

FIG. 1 is an overall schematic plan view of an embodiment for explaining the present invention. FIG. 2 is a schematic explanatory diagram of the prior art. W...work, B...grinding wheel. 1... Work sticking plate, 1a... Work sticking surface, 1b... Other side of work sticking plate, 1c... Tapered part, 1d... Perfect circular hole, 2... Work spindle, 2a... Tip surface, 3... Center,
3a... tip apex.

Claims (1)

[Claims] 1. In a method of grinding a workpiece made of a magnetic material by attaching it to a workpiece attachment plate, the center side of the workpiece attachment surface of the workpiece attachment plate is brought into contact with the tip of a workpiece spindle that rotates under power. A slightly wide annular tip surface is formed, a workpiece is pasted on the outer periphery of the workpiece pasting surface of the workpiece pasting plate, and a perfect circular hole with a tapered part is formed in the center of the other surface. A center is formed into a conical tip having a taper that matches the taper of the perfect circular hole, and is moved forward and backward in the axial direction using air or the like and can freely rotate. The grinding wheel that grinds the grinding surface of the workpiece rotates on its own by inserting it into the tapered part of the hole in alignment with the workpiece attachment plate and sandwiching the workpiece attachment plate between the tip end of the center and the front end surface of the workpiece spindle. In addition, by being close to the grinding surface so that it can move forward and backward,
A method for grinding a magnetic material, characterized in that the reference surface for grinding is the workpiece attachment surface of a workpiece attachment plate.