JP2001157969A - Grinding tool and grinding method using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To increase the cutting depth of a grinding tool and improve the machining speed and machining life of the tool. A spiral groove is formed on a side surface of a columnar body forming a grinding tool, in which a peak 3 and a valley 4 having a radius of curvature of 0.2 to 3.0 mm are continuous, and abrasive grains adhere to the surface. A grinding section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding tool used for roughing hard materials such as ceramics and cermets.

[0002]

2. Description of the Related Art Originally, cutting and grinding of metal materials and the like have been performed using a machining center and an end mill. In order to perform these processes with high efficiency and high accuracy, improvements and improvements have been made to the outer peripheral cutting edge shape of the end mill (see Japanese Patent Application Laid-Open No. Hei 6-170633).

On the other hand, in the production of ceramics and cermet products, first, a raw material powder is formed into a predetermined shape and fired.
A predetermined portion is ground to have a required shape. In the grinding step, the grinding is performed using a straight grinding tool 11 as shown in FIG. The straight grinding tool 11 is a cylindrical body made of a steel material such as 45C, and has a grinding portion 12
And abrasive grains 15 such as diamond are fixed to the surface of the grinding portion 12, and a plurality of slits 19 for supplying a grinding fluid (not shown) are provided around the periphery.

As shown in FIG. 9, a straight grinding tool 1 is formed by using a machining center main body (not shown).
1 is rotated at a high speed of about 1000 rpm, and the slit 19 is rotated.
Grinding can be performed by pressing the grinding unit 12 against the workpiece 16 such as a ceramic material at a feed rate of about 70 mm / min while supplying a grinding fluid (not shown).

[0005] The grinding fluid is composed of an emulsifier and serves to lubricate and cool the straight grinding tool 11 and the workpiece 16 during processing. However, when such a straight grinding tool 11 is used, the abrasive grains 15 gradually become clogged and the sharpness deteriorates, so that the use is stopped and the electrodeposition is performed again. .

[0006]

However, the conventional straight grinding tool 11 has a large grinding resistance because the grinding surface is flat, and it is difficult to perform cooling or the like. There is a problem that it is as small as about 100 to 3/10 mm, requires a very long processing time, and has a short processing life of the tool.

[0007]

In view of the above, according to the present invention, the radius of curvature R is set to 0.2 on the side surface of the cylindrical body of the grinding tool.
It is characterized in that a spiral groove having a peak and a valley of up to 3.0 mm is formed continuously, and abrasive grains are adhered to the surface thereof to form a ground portion.

In the lowermost portion of the columnar body, the starting portion of the ridge is smoothly continuous or a straight portion having a width of 0.5 to 1.0 mm is formed at the lowermost portion of the columnar body. Or a groove width of 1.0-3.
A cross-shaped slit having a depth of 0 mm and substantially the same depth as the width of the straight portion is provided.

Further, according to the present invention, while rotating these grinding tools, the grinding portion formed on the side face is pressed against the workpiece to perform grinding, thereby greatly improving the cut amount, the processing speed, and the tool life. It is like that.

[0010]

Embodiments of the present invention will be described below.

As shown in FIG. 1, a grinding tool 1 of the present invention
Has a spiral groove formed by continuous peaks 3 and valleys 4 having a radius of curvature of 0.2 to 3.0 mm formed on a side surface of a columnar body made of 45C steel or the like, and abrasive grains 5 such as diamond are formed on the surface thereof.
To form a grinding unit 2.

By providing the spiral groove in the grinding portion 2 as described above, the effective surface area of the grinding portion 2 can be increased, and the grindability can be improved by a mechanism described later.

Further, when the peaks 3 and the valleys 4 are formed into sharp edge shapes, the abrasive grains are more likely to be peeled off with use and the tool life is shortened, but the radius of curvature is 0.2 to 3.0 mm. This can be prevented by forming a curved surface having

As shown in FIG. 6, the grinding tool 1 having a spiral groove is rotated at a high speed of about 1000 rpm using a machining center main body (not shown) to supply a grinding fluid to the workpiece 6 such as ceramics. 100
Grinding can be performed by pressing the grinding portion 2 formed on the side surface at a feed speed of about mm / min.

As shown in FIG. 7, the grinding mechanism 1 rotates the grinding tool 1 at a high speed to cut into the surface of the workpiece 6 such as ceramics at the peak 3 of the spiral groove, and to cut the valley 4. By grinding and pushing up the remaining part of the ceramic, it is crushed and removed.

Here, the peak 3 and the valley 4 of the spiral groove
The reason why the curvature radius R is set to 0.2 to 3.0 mm is that if the curvature radius R is less than 0.2 mm, the peak portion 3 is too small, so that it is close to the straight grinding tool 11 and the cutting depth cannot be increased. This is because the peak 3 is easily crushed and the working life is not extended. On the other hand, if the radius of curvature R exceeds 3.0 mm, a load is excessively applied, which causes problems such as breakage of the tool and stop of the device. is there.

Further, by forming a spiral groove in the grinding section 2, the surface area of the grinding section 2 can be increased and grinding can be performed. The grinding portion 2 having the spiral groove of the present invention has a surface area of about 2 compared to the conventional straight grinding tool 11.
As the grinding area is doubled accordingly, the amount of energy transfer also increases.

Further, since the surface of the grinding portion 2 and the surface of the workpiece 6 do not come into close contact with each other due to the spiral groove, the grinding fluid is sufficiently supplied to the grinding surface, and cooling is effectively performed. ) Is sufficiently removed. Furthermore, although the coolant is repelled by the straight grinding tool 11, sufficient supply to the grinding surface cannot be performed. However, in the grinding tool 1 of the present invention, cooling water is guided to the groove and is not repelled. This makes it possible to greatly increase the processing speed and the processing life.

On the other hand, the preferable pitch range of the spiral groove is preferably 1 to 4 mm. This means that the pitch is 1mm
If it is less than 4 mm, the thickness becomes thin and the strength of the metal base material decreases. Conversely, if it exceeds 4 mm, a large grinding resistance is applied between the grinding tool 1 and the workpiece 6, damaging the tool and the workpiece 6. It is because it causes.

The preferred depth range of the spiral groove is 0.5 to 2.0 mm. This is 0.5m
If it is less than m, the cooling water will not spread well, and the removal of grinding debris will be insufficient. Conversely, if it exceeds 2.0 mm, the strength of the metal base material will decrease.

A more preferable range of the angle θ of the spiral groove is 20 ° to 100 °. This is because when the angle is less than 20 °, the metal base material becomes thin and the strength is reduced.
If ゜ is exceeded, the gap with the workpiece 6 becomes small, and the cooling effect and the removal effect of grinding debris decrease.

As shown in FIGS. 2A and 2B,
In the lowermost end face 8 of the grinding tool 1 in which the spiral groove is formed, it is necessary that the starting portion 3a of the peak 3 is formed smoothly and continuously.

This is because, as shown in FIGS. 3A and 3B, if the starting portion 3a of the peak 3 is not smoothly continuous and is stepped, a load is applied to the starting portion 3a. This is because the problem of concentration and immediate damage occurs.

Alternatively, in order to solve the problem as shown in FIG. 3, as shown in FIG. 4, a width of 0.5 to 1.0 mm is provided at the lowermost portion of the grinding tool 1 in which the spiral groove is formed. By providing the straight portion 7, the lowermost portion can be prevented from being damaged.

Here, the width of the straight portion 7 is 0.5 mm
If it is less than the maximum value, the load concentrates on the starting portion 3a of the peak 3 and the lowermost portion is damaged. Conversely, the width of the straight portion 7 is 1.0
If it exceeds mm, the sharpness is reduced and the life is shortened, for example, because the cooling water is not sufficiently supplied to the lowermost portion.

More preferably, as shown in FIG. 5, the starting portion 3a of the peak 3 is provided on the end face 8 of the straight portion 7 of the grinding tool 1.
Groove width 1.0-3.0 so as to be shifted by 45 ° from
It is also possible to provide a cross-shaped slit 9 having a depth substantially equal to the width of the straight portion 7 in mm. By providing the slits 9, the cooling water is sufficiently supplied from the slits 9 to the straight portions 7 so that the tip portions are not damaged, and the processing using the end surfaces 8 by fixing the abrasive grains 5 such as diamond to the end surfaces 8. Work is also possible, and usage applications are expanded.

Here, the groove width of the cross-shaped slit 9 is 1.
If it is less than 0 mm, the cooling and sludge removal effects are reduced, the sharpness is reduced, and the tool life is also reduced.
Conversely, when the width of the cross-shaped slit 9 exceeds 3.0 mm, the strength of the grinding tool 1 itself decreases, and the tool life is shortened. Also, the depth of the cross-shaped slit 9 is 0.5 mm
If it is less than this, the cooling and sludge removing effects are reduced, the sharpness is reduced, and the tool life is also reduced. Conversely, if the depth of the cross-shaped slit 9 exceeds 1.0 mm, the strength of the tool itself is reduced, and the tool life is shortened.

In the above embodiment, one spiral groove is formed. However, a plurality of spiral grooves such as two or three spiral grooves may be formed.

The abrasive 5 has a particle size of # 70.
It is preferable to use diamond abrasive grains of # 300 to # 300.

Further, the method for fixing the abrasive grains is the electrodeposition method in which diamond or CBN abrasive grains are sprayed on the surface of a wheel body having conductivity in an electrodeposition tank to hold and fix the abrasive grains by nickel electroplating. In addition, a resin bond, a metal bond, a pyridine bond, or the like may be used.

The grinding tool 1 with a spiral groove of the present invention
Is not limited to the above-mentioned example of the machining center, and may be used for a milling machine, a surface grinding machine or the like without departing from the spirit of the present invention.

[0032]

EXAMPLES (Experimental Example 1) Here, a conventional straight grinding tool 11 shown in FIG. 8 and a spiral grooved grinding tool 1 of the present invention shown in FIG. All are made of 45C steel material, total length 150mm, grinding part 2,
12 has a diameter of 20 mm.
0 diamond abrasive grains 5 and 15 were fixed. The radius of curvature R of the peak 3 and the valley 4 of the spiral groove was 0.3 mm.

The workpieces 6 and 16 are made of alumina ceramics having an Al ₂ O ₃ content of 99% and a thickness of 40 m.
The conventional straight grinding tool 11 has a feed rate of 70 mm / min, and the grinding tool 1 with a spiral groove of the present invention has a feed rate of 100 mm / min while grinding and rotating at 1000 rpm using the above tool. And press the grinding fluid consisting of emulsifier from the upper part of the main body by 20k.
The workpiece was ground while applying and supplying a pressure of g / cm ² , and the cut amount, the processing speed, and the processing life of each were compared. The results are as shown in Table 1.

As shown in Table 1, the conventional straight grinding tool 11 is different from the spiral grooved grinding tool 1 of the present invention.
It can be seen that cutting can be performed four times or more as compared with the conventional cutting amount, the machining speed is increased by 30%, and the tool life is doubled.

[0035]

[Table 1]

(Experimental Example 2) Next, the diameter of the grinding portion 2 of the grinding tool 1 of the present invention was set to 20 mmφ,
The grindability was compared by changing the radius of curvature R of the valleys 4 and the valleys 4. The grinding conditions were the same as in Experimental Example 1. Table 2 shows the results.

As can be seen from Table 2, when the radius of curvature R is 0.1 mm or 4.0 mm, no great effect is observed, but R is in the range of 0.
In the range of more than 2 mm and less than 3.0 mm, it can be seen that both the cutting depth and the working life clearly increase.

[0038]

[Table 2]

(Experimental Example 3) Next, as in Experimental Example 2, the diameter of the grinding portion 2 of the grinding tool 1 of the present invention was set to 20 mmφ, and the radius of curvature R of the ridges 3 and valleys 4 of the spiral groove was set to 1.0 mm. ,
The grindability was compared for those without the straight part 7 at the bottom, those with the straight part 7, and those with the slit 9 in the straight part 7. The grinding conditions were the same as in Experimental Example 1. Table 3 shows the results.

From Table 3, it can be seen that No. 7 having no straight portion 7 at the lowermost position. No. 1 and No. 1 where the straight part 7 is short or the groove width of the slit 9 is narrow. No increase in working life was observed for Nos. 2 to 5. This is because the effect is not obtained because each dimension is too small.

On the other hand, the width of the slit 9 and the straight portion 7
The dimension is too large or the groove width of the slit 9 is too wide N
o. Also in Nos. 8 to 11, no increase in machining life was observed due to poor workability of the straight portion, a decrease in the strength of the grinding tool itself, and the like.

On the other hand, no. As for Nos. 6 and 7, the effects of the straight portion 7, the slit 9 and the like appear, and it can be seen that the working life is increased.

[0043]

[Table 3]

[0044]

According to the present invention, a spiral groove having a radius of curvature of 0.2 to 3.0 mm with continuous peaks and valleys is formed on the side surface of a cylindrical body of a grinding tool, and abrasive grains adhere to the surface. As a result, the surface area of the processed surface can be increased to perform the grinding.

In addition, since the starting portion of the ridge portion is smoothly continuous at the lowermost portion of the columnar body, the load is concentrated at the starting point of the tip ridge portion, and the tip portion is immediately damaged. The problem can be solved.

Alternatively, at the bottom of the columnar body, 0.5
By providing a straight part with a width of ~ 1.0 mm,
The tip can be prevented from being damaged.

Further, a groove width 1.
By providing a cross-shaped slit having a depth of 0 to 3.0 mm and a width of the straight portion, cooling water is sufficiently supplied from the slit to the straight portion, the tip portion is not damaged, and the tool life can be further increased. At the same time, by fixing abrasive grains such as diamond to the surface of the lowermost end, a working operation using the lowermost end becomes possible, and the use application is further expanded.

Then, when the grinding tool is rotated and the grinding portion formed on the side face is pressed against the workpiece, and the grinding is performed, the tool surface does not adhere to the ceramic material surface due to the spiral shape, and the grinding fluid is sufficiently ground. Since it is fed to the surface and cooled effectively, and sludge (powder) is sufficiently removed, it is possible to cut more than four times the conventional cutting amount. Further, the machining speed can be increased by 30%, and the tool life can be increased three times or more.

[Brief description of the drawings]

FIG. 1 is a side view showing a grinding tool of the present invention.

FIG. 2A is a side view showing the lowermost part of the grinding tool of the present invention, and FIG. 2B is a bottom view thereof.

FIG. 3A is a side view showing a lowermost portion of a grinding tool of a comparative example, and FIG. 3B is a bottom view thereof.

FIG. 4 is a side view showing another embodiment of the grinding tool of the present invention.

FIG. 5A is a side view showing another embodiment of the grinding tool of the present invention, and FIG. 5B is a bottom view thereof.

FIG. 6 is a schematic view showing a processing method using the grinding tool of the present invention.

FIG. 7 is an enlarged sectional view showing a processing state using the grinding tool of the present invention.

FIG. 8 is a schematic view showing a conventional straight grinding tool.

FIG. 9 is a schematic view showing a processing method using a conventional straight grinding tool.

[Explanation of symbols]

 1: Grinding tool 11: Straight grinding tool 2, 12: Grinding part 3: Crest part 4: Valley part 5, 15: Abrasive 6, 16: Workpiece 7: Straight part 8: End face 9, 19: Slit

Claims (5)

[Claims] 1. A method according to claim 1, wherein a radius of curvature of 0.2 to 3.
0mm peaks and valleys form a continuous spiral groove,
A grinding tool characterized in that abrasive grains are attached to the surface to form a grinding portion. 2. The grinding tool according to claim 1, wherein a starting portion of the peak is formed smoothly and continuously at a lowermost portion of the columnar body. 3. The method according to claim 1, wherein the lowermost part of the columnar body is 0.5 to 1.0.
The grinding tool according to claim 1, wherein a straight portion having a width of mm is provided. 4. The end face of the straight portion has a groove width of 1.0 to 1.0.
4. The grinding tool according to claim 3, wherein a cross-shaped slit having a depth of 3.0 mm and substantially the same depth as the width of the straight portion is provided. 5. A grinding method, characterized in that a grinding part formed on a side surface is pressed against a workpiece while the grinding tool according to claim 1 is rotated to perform grinding.