JPS6263066A - Grinding wheel - Google Patents

Abstract

PURPOSE:To obviate grinding vibration generated in grinding with a simple construction by compounding a vibration attenuating material having creep-like physical property and a grinding wheel base plate so that a grinding wheel itself is provided with self-vibration absorbing property. CONSTITUTION:This grinding wheel 1 is formed by bonding or applying a vibration attenuating material 3 to the end face of a grinding wheel 2 used for surface grinding, cylinder grinding, internal grinding, centerless grinding and cutting grinding. When the surface grinding is carried out by the thus formed grinding wheel 1, the grinding wheel 2 and the vibration attenuating material 3 are sandwiched by the head 4 of grinding wheel spindle and a flange 5, fastened and mounted by tightening a fastening nut 6 to grind a work piece 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grinding wheel capable of isolating grinding vibrations generated during abrasive processing.

[Prior art]

Generally speaking, in grinding process ■, 1, J3, which is a type of abrasive processing, the grinding wheel comes into severe direct contact with the object to be ground.
3000-700 (lyf
Since the specific grinding resistance of /- is irregularly applied to a minute area, extremely large grinding vibrations occur.

In order to improve grinding precision, it is necessary to eliminate this grinding vibration.

Conventionally, therefore, dehumidification has been carried out by changing the grinding conditions, such as changing the grinding width or cutting depth of the object to be ground, or adding lubricity to the grinding oil. In addition, conventionally, other methods have been used to dehumidify, such as mechanical engineering methods that improve the main shaft rigidity of the grinding wheel and the machine side, such as using a high-damping fluid floating table. Ta.

[The problem that the invention attempts to solve] However,
It is difficult to sufficiently eliminate vibrations using such conventional methods, and judging from the history of research to date, dehumidification technology that adjusts the grinding conditions and the machine itself has almost reached its limit. I'm coming to

Therefore, the inventor of the present invention used a grindstone itself to grind ffi!, which is completely different from the conventional vibration isolation technology. We believe that there is a need to develop a grinding wheel that can isolate vibrations.

The present invention has been made in view of these points, and it is an object of the present invention to provide a self-vibration-absorbing grinding wheel in which the grindstone itself has a vibration-absorbing ability.

[Means for solving problems]

The grinding wheel of the present invention is characterized in that it is formed by attaching a vibration damping material to the grinding wheel used for adding abrasive grains.

To explain further, in order for the grinding wheel to have self-absorptive properties and achieve a vibration isolation effect, it is necessary to configure the grinding wheel so that it performs over-damped motion that has an extremely large damping effect compared to the rigidity effect.

Therefore, in the present invention, the grinding wheel is formed by combining the grinding wheel substrate with a vibration damping material having extremely overdamping performance, so to speak, creep-like physical properties, without performing any processing on the grinding wheel substrate. are doing.

Further, by using a polymeric material having a small dynamic V-Fugu ratio and a large loss coefficient as the vibration damping material, an excellent vibration damping effect is achieved.

More specifically, in order to reduce uncut holes caused by unstable elastic deformation of the grinding wheel and improve grinding accuracy, the vibration damping material is bonded to the side surface of the grinding wheel disk or one side of a stick grinding wheel for lapping, etc. to form a grinding wheel.

[Action of the invention]

When grinding is performed using the grinding wheel of the present invention, the vibration-damping material absorbs the grinding vibrations generated by the elastic deformation of the grinding wheel, so the grinding vibrations are isolated, thereby improving the grinding accuracy. As described above, according to the grinding wheel of the present invention, surface grinding,
Current general precision grinding processes such as cylindrical grinding, cutting grinding, internal grinding, centerless grinding, and tool grinding can be performed. Furthermore, it is also possible to perform ultra-precision polishing and lapping of substrates such as silicon wafers and aluminum alloys for magnetic disks. Moreover, unlike the conventional example, the present invention does not require adding any unfavorable restrictions to the grinding conditions, such as limiting the grinding speed, nor does it require expensive modification of the mechanical structure. Economical grinding can be carried out using the same method.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 13.

1 and 2 show a grinding wheel 1 according to an embodiment of the present invention. This grinding wheel 1 is suitable for surface grinding, cylindrical grinding,
It is formed by attaching a vibration damping material 3 to the end face of a grindstone 2 used for internal grinding, centerless grinding, cutting grinding, etc. by adhering or coating it. When surface grinding is performed using the grinding wheel 1 formed in this way, the grinding wheel 2 is held with the flange 5 on the grinding wheel spindle head 4 as shown in FIG.
Then, the vibration damping material 3 is clamped and attached by tightening the tightening nut 6, and the workpiece 7 is ground.

FIGS. 4 and 5 show a grinding wheel 8 according to another embodiment of the present invention.
It shows. This grinding wheel 8 is formed into a cup shape. It is formed by sequentially bonding an annular vibration damping material 10 and a grindstone 11 to the front end surface of a cup-shaped substrate body 9.

FIG. 6 shows a grinding wheel 12 according to yet another embodiment of the present invention. This grinding wheel 12 is used for finishing lapping of semiconductor silicon substrates, magnetic disk aluminum alloy substrates, etc., and is formed by attaching a vibration damping material 14 to one side of a sponge grinding wheel 13 by adhering or coating it. . Grinding wheel 12 formed in this way
In the case of lapping one side with a lapping machine, as shown in FIG. 7, a plurality of grinding wheels 12, 12 are attached to the grinding wheel holder 15 of the lapping machine with the sponge grinding wheels 13 facing outward. When lapping both sides, as shown in FIG.
．． Grinding wheels 12 of facing la attached to 15 respectively
．． Lapping is performed by sandwiching the workpiece 7 from above and below with 12 sponge grindstones 13 and 13.

Next, the grinding wheel 1°8.12 thus formed
We will explain the grinding experiment conducted by.

1) About the workpiece 7 The workpiece 7 is carbon steel for mechanical structure (SS41, 520C, 555C, SK7°5K3),
Bearing w4 (SUJ2~4), die steel (SKD1~11
), high speed steel (SKF-12,4゜9.50,55.5
7), carbon-free steel, copper alloy and aluminum alloy were used.

Here, the composition is /l-(0,003-6.62>wt% Mg or A, Q-(0,005-6.36)wt% Zn, Jl55086 02T4, from Te-treated aluminum alloy. The experimental results are shown for workpiece 7. Similar results were obtained for other materials.

2) Vibration Damping Materials 3.10.14 Polymer materials consisting of Samples 1 and 2 having the following physical properties were used as vibration damping materials 3 and 10.14.

Sample 1 20℃, 1000Hz: 4x102<hf
/cIi>Dynamic V-leg ratio tensile strength ゛
63 (Klf/ci) Shin
590 (%) hardness (JISA
) ” 60 specific gravity
°1.120℃, 1000Hz ・1
．． 2 Loss coefficient (tan δ) Sample 2 20℃, 1000H2: 1.5X10 (
K'iif /d>Dynamic Young's modulus tensile strength ° 79
(Ngf/c!i> Growth
° 350 (%) hardness (JISA)
° 93 specific gravity 1
．． 120°C, 1000Hz '0.4 loss coefficient pan δ) 3) Grinding conditions Grinding was carried out under the following grinding conditions.

Peripheral speed of grinding wheel: Vs = 1800 m/win Speed of workpiece: Vw = O ~ 30 m/sin Grinding wheel cutting depth: d =
1~30μm Grinding method: Downward flat flange grinding
Liquid: JISW Class 1 30 times diluted water Stone: PV
A800. Same 1000. Same 1500゜ Same 2000. Same 3
000. Same 6000S.

k^60LmV, 5DC120R100B.

GC150PmV, CBN140117OR100B
4) Experimental results As shown in Figure 9, the relationship between the depth of cut of the grinding wheel 1 and the finished surface roughness Rmax is as follows. , the rough finished surface of sample 1 equipped with vibration damping material 2 (line B in the figure) and the rough finished surface of sample 2 (line C in the figure) are both finer. Note that the workpiece 7 contains 99.9% by weight A! J
is used. In this way, the grinding wheel 1 of this embodiment
Since the vibration damping material 2 is attached, the roughness of the finished surface can be kept small. In this case, a smaller depth of cut is more effective, and overall the finished surface roughness is finely improved by 10 to 30%. In particular, sample 1 can more effectively reduce the finished surface roughness.

In addition, using zero-treated AJ-Zn alloy material as workpiece 7, the normal grinding resistance Fn and the contact grinding resistance Ft are examined for the normal grinding resistance Fn and the contact grinding resistance Ft, in the case where no vibration damping material is installed as in the conventional case, and in the case of sample 1 or sample 2. Fig. 10 shows a comparison of the experimental results with the case where a damping material is attached. This first
As can be seen from the characteristics in Figure 0, both the normal grinding resistance Fn and the tangential grinding resistance Ft are different when no vibration damping material is installed (
It is smaller when sample 1 is attached (lines 3/, 3/l in the same figure) and when sample 2 is attached (lines c' and c"° in the same figure) than when sample 1 is attached (lines c' and c" in the same figure). In particular, in the case of sample 1, the grinding resistance can be reduced by about 50%.A similar experiment was conducted on workpiece 7 made of Aj-MQ alloy, but it was found that the same effect as in the case of AJ-Zn alloy was obtained. I was able to get it.

This reduction in grinding resistance is most significantly caused by a reduction in the fluctuation component of the grinding resistance, and is not due to a reduction in the depth of cut due to the attachment of the vibration damping material.

For example, when performing ultra-precision machining with a cutting tool without using the grinding wheel of this example, a vibration damping material made of Sample 1 or Sample 2 may be interposed at the joint between the headstock and the bed of the ultra-precision processing machine. It can be seen from FIGS. 11(a), 11(b), and 11(c), which show the frequency characteristics with and without intervening, that the reduction in grinding resistance has the greatest effect on the reduction in the fluctuation component of the grinding resistance. In other words, Fig. 11 shows the vertical vibration waveform of the spindle head and the power obtained by frequency analysis at that time, and the average amplitude is approximately 3.6 mV when no vibration damping material is installed (Fig. 11(a)). When sample 1 is attached, the voltage is about 0.6 mV ((b) in the same figure), and when sample 2 is attached, it is about 2.4 mV ((c) in the same figure). Therefore, the average amplitude was reduced by about 85% when Sample 1 was attached, and by about 35% when Sample 2 was attached, and it is recognized that there is a significantly greater vibration isolation effect than when these are not attached. In addition, sample 1 has a low frequency band of about 3KH2 or less, so compared to the 7KHz frequency range of sample 2112, which has relatively high hardness or when no vibration damping material is installed, it has a high frequency band that is disliked in ultra-precision machining. It can be seen that it is also highly effective in isolating frequency vibrations.

Moreover, according to the results shown in FIG. 11, the removal rate during grinding shows an increasing tendency, and it can be seen that the reduction in the fluctuation component of the grinding resistance directly leads to a stable increase in the removal rate. In other words, it can be considered that a decrease in the amplitude of the grindstone in the cutting direction increases the removal rate.

The reduction in grinding resistance is especially remarkable when m during grinding.
The tangential grinding resistance Ft affects the vibration force, and as shown in FIG. 12, a large decrease in the tangential grinding resistance Ft is observed in the precision machining area under light grinding conditions. The data shown in FIG. 12 was obtained by wet grinding using the grindstone 2 of PVA800S and the workpiece 7 of 99.9% Aj.

Figure 13 shows that during the grinding test in Figure 12, the grindstone 2 and the workpiece were left as they were, and the speed of the workpiece was set to Vw = 5 m.
/mtn, and the vibration waveform in a direction perpendicular to the ground surface when grinding is performed with a depth of cut of d-15 μm is shown in the same manner as in FIG. According to this, the average amplitude is about 45 mV when no vibration damping material is attached, about 16 mV when sample 1 is attached, and about 25 mV when sample 2 is attached.
It is 7FLV. That is, the average amplitude decreases by about 65% when sample 1 is attached, and about 50% when sample 2 is attached.

It can be seen that the fluctuation component of the grinding resistance is thus greatly reduced. In particular, if the vibration damping material shown in Figure (a) is not installed, a resonance frequency with large power will occur around 5.5Kl-IZ (part A), but as shown in Figures (b) and (c). When sample No. 311 and sample 2, which are vibration damping materials, are attached, no such resonance frequency occurs, and this is particularly noticeable in the case of sample 1.

In this way, the fluctuation component of the grinding resistance is reduced, so
Grinding accuracy can be improved by reducing surface roughness and waviness.

Furthermore, by attaching the grinding wheel 1.8.12 of this example to a grinding machine in which vibration damping material is interposed individually or simultaneously at the fastening parts and joints of each component of the grinding machine, the grinding resistance can be further reduced. It is better to attenuate it.

〔Effect of the invention〕

As described above, the grinding wheel of the present invention has a vibration absorbing function itself, and its self-absorbing property allows it to isolate the grinding vibrations generated during grinding, thereby eliminating the need to limit the grinding conditions as in conventional methods. It also eliminates the need for expensive modifications to the mechanical structure, and has advantages such as a simple structure and low cost.

[Brief explanation of drawings]

1 to 3 show one embodiment of the grinding wheel of the present invention, FIG. 1 is a perspective view, FIG. 2 is a vertical side view, FIG. 3 is a perspective view showing the grinding state, FIG. Fig. 5 shows another embodiment of the present invention, Fig. 4 is a perspective view, Fig. 5 is a longitudinal side view,
6 to 8 show still other embodiments of the present invention, FIG. 6 is a perspective view, FIG. 7 is a perspective view showing single-sided wrapping,
Fig. 8 is a longitudinal cross-sectional side view showing double-sided lapping, Fig. 9 is a characteristic diagram showing the III relationship between the cutting depth of the grindstone and the finished surface roughness;
Figure 10 is a characteristic diagram showing the relationship between grinding resistance and grinding wheel for All-Zn alloy, and Figure 11 (a>(b)(C)
12 is a characteristic diagram showing the relationship between paper width, power, and frequency when vibration damping material is interposed and not interposed in the fastening parts of the headstock and bed of an ultra-precision processing machine, respectively.
The figure is a diagram showing a comparison of grinding resistance due to differences in grinding conditions and grinding wheels. Figure 13 (a), (b), and (c) show the relationship between the imaging width in the direction perpendicular to the grinding surface and power and frequency, respectively. It is a characteristic line diagram. 1.8.12...Grinding whetstone, 2.11...Whetstone, 3
．． 10.14...Vibration damping material, 13...Sponge grindstone. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1) A grinding wheel characterized in that a grinding wheel used for abrasive processing is equipped with a vibration damping material. 2) The vibration damping material has a dynamic Young's modulus of 10^2 to 3×1
2. The grinding wheel according to claim 1, wherein the grinding wheel is made of a polymeric material having a loss coefficient of 0^4 kgf/cm^2 and a loss coefficient (tan δ) of 0.1 or more.