JP2000084819A - Grinding method using integrated grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To machine a workpiece with high accuracy without generating a streak (flaw) to a specific part of the workpiece surface while using a formed grinding wheel by polishing abrasive grains of a grinding wheel layer on the surface of the formed grinding wheel before grinding the workpiece so as to make the protruding height of the abrasive grains constant. SOLUTION: The position of a flaw generated when a workpiece is ground is the case of a protruding abrasive grain 13 existing in a grinding wheel layer 12 electrodeposited to a formed grinding wheel 101 is measured, and the existing position of the protruding abrasive grain 13 corresponding to the flaw is specified in the radial direction of a grinding wheel rotation axis 14 from the position relation between the grinding wheel rotation axis 14 and a workpiece rotation axis. A probe of a surface shape measuring device is disposed in a radial position where the protruding abrasive grain 13 exists, to circumferentially specify the position of the protruding abrasive grain 13, where the surface height of the grinding wheel layer is protruded. A polishing tool 35 is positioned to polish only the tip of the protruding abrasive grain 13 so as to be the same height as its periphery. The protruding abrasive grain 13 is therefore eliminated, and the protruding height of abrasive grains on the surface of the grinding wheel layer 12 can be made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a form grinding wheel used for grinding a form.

[0002]

2. Description of the Related Art There is known a method of performing a grinding process using a form grinding wheel. FIG. 1 shows a method of processing a convex lens using a form grinding wheel. Form grinding wheel 101 of FIG.
Is composed of a grindstone base material 11 having a rotating body shape and a grindstone layer 12 formed on a side surface thereof. The shape of the side surface of the general-purpose grinding wheel 101 is formed along the radial direction so as to match the shape of the workpiece 15 in the radial direction. Form grinding wheel 1
Grinding is performed by cutting the grindstone layer 12 into the workpiece 15 while rotating the workpiece 01 and the workpiece 15 at a predetermined number of rotations, respectively. In order to obtain a precise machined surface by this grinding method, it is necessary to form the grindstone layer 12 with fine abrasive grains and to form the surface of the grindstone layer 12 with a desired shape with high precision. However, at present,
Even if fine abrasive grains are used, a streak (scratch) is formed on the surface of a specific portion of the workpiece, and it is necessary to add a polishing step after the grinding process to remove the scratch.

[0003]

However, in order to reduce the cost, it is necessary to shorten the processing time, and it is desired to omit the polishing step. Even in the grinding process using a conventional form grinding wheel, the use of fine abrasive grains allows portions other than streaks (scratches) to be within usable working accuracy. Therefore, if only this specific flaw is eliminated, production by only grinding is possible.

[0004] It is an object of the present invention to provide a grinding method capable of performing a high-precision machining without causing a streak (scratch) on a specific portion of a workpiece surface while using a form grinding wheel. .

[0005]

In order to achieve the above object, the present invention provides a grinding method using a general-purpose grinding wheel, wherein the surface of the general-purpose grinding wheel is ground before grinding the workpiece. A grinding method characterized by comprising a step of polishing abrasive grains of a grindstone layer to make the protrusion height of the abrasive grains constant.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have investigated the cause of generation of streaks (scratch) on the surface of a workpiece even when a grinding layer is formed of fine abrasive grains in a grinding method using a form grinding wheel. It was found that the cause was that the protrusion height of the abrasive grains on the surface of the grindstone layer was not constant. That is, in the form grinding wheel 101 of FIG. 1, abrasive grains having a height higher than other abrasive grains protrude from a part of the surface of the grindstone layer 12. Figure 2
It was found that scratches occurred concentrically as shown in FIG. FIG. 2 shows scratches appearing on the workpiece 15 when there are two protruding abrasive grains 13 in the grindstone layer 12 of the form grinding wheel. The scratches are scattered concentrically around the rotation axis 16 of the workpiece 15. The present invention specifies the position of the protruding abrasive grains 13 present in the grindstone layer 12 based on the shape of the flaw, polishes the tips of the protruding abrasive grains 13 to make the height uniform, and forms the uniform grinding wheel 101. Improve the shape accuracy of

An embodiment of the present invention will be described below with reference to FIGS. 1, 2 and 3. In the present embodiment,
The convex lens is machined with a form grinding wheel.

[0008] As shown in FIG.
A grindstone substrate 11 having a rotating body shape about the rotating shaft 14;
And a grindstone layer 12 formed on the side surface. The surface shape of the side surface of the form grinding wheel 101 is, in the radial direction,
It is formed so as to match the shape of the workpiece 15 in the radial direction. The grindstone layer 12 is formed by electrodeposition.

In the case of performing a grinding process using the general-purpose grinding wheel 101, the general-purpose grinding wheel is rotated about the grinding wheel rotating shaft 14, and the workpiece 15 is rotated about the workpiece rotating shaft 16. In this state, when the grindstone 101 is pressed against the workpiece 15, the side surface of the grindstone 101 and the workpiece 15 linearly contact in the radial direction, and the grindstone layer 12 cuts into the workpiece 15, and the form grinding is performed. The surface shape in the radial direction of the grindstone 101 is transferred to the surface of the workpiece 15.

As described above, the forming grinding wheel 101 forms the grinding layer 12 by electrodeposition, but it is very difficult to make the protrusion height of the abrasive grains existing in the grinding layer 12 constant. In addition, several protruding abrasive grains 13 exist in the grindstone layer 12. Therefore, in the present embodiment, the form grinding wheel 1
After the electrodeposition of the grindstone layer 12 on the base material 01 and before the actual grinding of the workpiece 15, a step of confirming the position of the protruding abrasive grains 13 and polishing the tip of the protruding abrasive grains 13 is performed.

Specifically, first, after the grinding wheel layer 12 is electrodeposited on the forming grinding wheel 101, a sample of the workpiece 15 is prepared.
This is ground. When the protruding abrasive grains 13 are present in the grindstone layer 13, as shown in FIG. 2, concentric scratches 201 are formed on the sample workpiece 15. FIG. 2 shows a case where two protruding abrasive grains 13 are present, and a scratch 201 is generated along two concentric circles. Next, the position of the flaw 201 of the sample of the workpiece 15 is measured, and the position of the grindstone layer 201 corresponding to the flaw 201 is specified based on the positional relationship between the grindstone rotating shaft 14 and the workpiece rotating shaft 16. Thereby, the position where the protruding abrasive grains 13 exist can be specified in the radial direction of the grinding wheel rotating shaft 14 of the form grinding wheel 101. The protruding abrasive grains are present on the circumference of the specified radius centered on the grinding wheel rotation shaft 14.

Next, the position where the protruding abrasive grains 13 exist on the grindstone layer 201 is specified in the circumferential direction. First, a probe of a surface shape measuring device is arranged at a radial position where it is determined that the protruding abrasive grains 13 are present.
1 is rotated along the rotation axis 14 and the surface shape of the grindstone layer 12 is measured. Since the form grinding wheel 101 has a rotating body shape, the surface height is constant, but the position of the protruding abrasive grains 13 has a protruding surface height. Thereby, the position of the protruding abrasive grains 13 can be specified in the circumferential direction.

Next, a polishing tool 35 having a thin tip is positioned at the position of the specified protruding abrasive grains 13.
Only the tip of No. 3 is polished. Thereby, the height of the protruding abrasive grains 13 can be made the same as the surroundings. The used polishing tool 35 has a mechanism that rotates about a polishing shaft 36 and can be positioned by a slide 37. In addition, the polishing tool 35 is a mechanism that can apply a constant pressure so that only the tip of the protruding abrasive grains 13 can be polished. Here, since the protruding abrasive grains 13 are present at two locations, the polishing tool 35 is moved as shown in FIG. Thereby, there is no protruding abrasive grain 13, and it is possible to obtain a form grinding wheel in which the protruding height of the abrasive grains on the surface of the grindstone layer 12 is constant.

After the protruding abrasive grains 13 of the shaped grinding wheel 101 are polished as described above, the workpiece 15 is usually subjected to grinding using the shaped grinding wheel 101. When grinding was actually performed using the form grinding wheel 101 according to the present embodiment, no circumferential flaw as shown in FIG. 2 was observed on the workpiece 15 and was not obtained by conventional processing. A highly accurate workpiece was obtained. Therefore, a highly accurate workpiece could be obtained only by grinding without performing the polishing step of the workpiece 15 as a post-processing step.

In the above embodiment, the scratch 201
After specifying the radial position of the protruding abrasive grains 13 from the shape of the protruding abrasive grains 13, further measuring the circumferential surface shape using a surface shape measuring device, and completely specifying the position of the protruding abrasive grains 13, Although the polishing of the abrasive grains 13 was performed, the protruding abrasive grains 13 can be removed by other methods. For example, after specifying the radial position of the protruding abrasive grains 13 from the shape of the scratch 201, the polishing tool 35 is arranged at the specified radial position without specifying the position of the protruding abrasive grains 13 in the circumferential direction. And, while rotating the form grinding wheel 101,
The polishing tool 35 is gradually brought closer to the grindstone layer 12. At this time, the polishing tool 35 is also rotated. Since the protruding abrasive grains 13 protrude from the surrounding grindstone layer 12, the polishing tool 35
, The tip of the protruding abrasive grains 13 first comes into contact with the polishing tool 35. Thereby, only the tip of the protruding abrasive grains 13 can be polished, and a uniform grinding whetstone in which the protruding height of the abrasive grains on the surface of the grindstone layer 12 is constant can be obtained. Therefore, by performing the grinding process using the form grinding wheel 101 from which the protruding abrasive grains 13 have been removed by this method, a highly accurate workpiece without scratches can be obtained only by the grinding process.

[0016]

As described above, according to the present invention,
It is possible to provide a grinding method capable of performing machining with high accuracy without using a form grinding wheel and without causing a line (scratch) on a workpiece surface.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the configuration of a conventional grinding wheel of the present invention and the present invention, and the method of grinding.

FIG. 2 is a top view of a workpiece for showing streaks (scratches) generated in the workpiece by the form grinding wheel of FIG. 1;

FIG. 3 is an explanatory view showing a step of polishing protruding abrasive grains 13 of the form grinding wheel according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Grinding-stone base material 12 ... Grinding-stone layer 13 ... Protruding abrasive grain 14 ... Grinding-stone rotation axis 15 ... Workpiece 16 ... Workpiece rotation axis 35 ... Polishing tool 101 ..Forming grinding wheels

Claims (1)

[Claims] Claims: 1. A grinding method using a form grinding wheel, wherein before grinding a workpiece, the abrasive grains of a grindstone layer on the surface of the form grinding wheel are polished to reduce the protrusion height of the abrasive grains. A grinding method characterized by having a step of making it constant.