JPS5890466A - Grinding wheel - Google Patents

Abstract

PURPOSE:To provide high strength grinding wheel by sintering main grains and auxiliary grains consisting of hot pressed silicon nitride. CONSTITUTION:A grinding wheel is formed of main grains 1 comprising diamond grains or CBN grains and auxiliary grains 2 of hot pressed silicon nitride having the diameter equal to the main grain or less and coated with Cu or Ni having 10-20mum thickness. The auxiliary grains 2 of 5-10% are mixed in bonding agent 3 consisting of regin bond to be sintered with the main grains 1. This hot pressed silicon nitride has excellent heat resisting, anti-high temperature-wear property, while preventing the main grains 1 from drop-out and breakage. Thus high feed-in grinding can be provided while wear of grinding wheel becomes few and accuracy in grinding and finish grinding can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a grinding wheel in which auxiliary abrasive grains are bonded to main abrasive grains made of, for example, diamond abrasive grains.

[Technical background of the invention and its problems]

Grinding wheels that combine diamond abrasive grains or CBN abrasive grains with a binder such as resin are being talked about, but the binder that holds these abrasive grains has poor wear resistance and poor heat resistance, making it difficult to achieve sufficient grinding performance. I can't get it. In other words, the bonding material generates heat due to frictional heat during grinding work, causing deterioration of the bonding material and abrasive grains falling off or being destroyed, making it impossible to withstand high cutting depths (30 μm or more) and reducing grinding efficiency. In addition, since only diamond abrasive grains or CBN abrasive grains act as a grinder, the grinding wheel wears out quickly, the surface roughness is poor, and the finish abrasion level is low.

[Purpose of the invention]

This invention was made in view of the above circumstances, and its purpose is to provide a grinding wheel that can improve grinding efficiency and finish accuracy.

[Embodiments of the invention]

The present invention will be described below based on an embodiment shown in the drawings. 1 in the diagram is diamond abrasive grain or CBN
A main abrasive grain consisting of abrasive grains, 2... is a hot-pressed silicon nitride having a grain size equal to or smaller than the main abrasive grain 1, and an auxiliary material coated with Cu or Ni with a thickness of 10 to 20 βm. It is an abrasive grain. The grinding wheel 4 is constructed by mixing 5 to 10% of the auxiliary abrasive grains 2 in a binder s made of resin bond and sintering the above together with the abrasive grains 1.

This hot pressed silicon nitride is heat resistant and high temperature 1llS'
4. It has excellent abrasiveness and typical properties as shown in Table 1, causing appropriate wear and tear on the bonding material 3 while preventing the main abrasive grains 1 from falling off and breaking. . Furthermore, a gap 5 is formed between the main abrasive grains 1 and the auxiliary abrasive grains 2 due to the difference in grain size, thereby facilitating the discharge of chips generated during grinding.

Table l Note that in the above example, 5 to 10% of hot-pressed silicon nitride was mixed into the binder 3, but the content capacity and particle size can be changed depending on the required cutting efficiency and accuracy. Although resin bond is used as the bonding material 3, other thermosetting resin materials may be used.

In addition, there is a coating on hot pressed silicon nitride,
The coating material and coating amount can be changed as appropriate depending on the material to be ground.

〔Effect of the invention〕

As explained above, in this invention, the main abrasive grains and the auxiliary abrasive grains made of hot-pressed silicon nitride are sintered together with a binder, so that high cutting depth grinding (30 μm% 50 μm) can be achieved.
This makes it possible to reduce the amount of wear on the whetstone, making it easier to sharpen! I
It is possible to improve l accuracy and finish grinding accuracy, and the comparison with conventional grinding wheels is as shown in Table 2.

Table 2 (Grinded material: structural ceramics)

[Brief explanation of the drawing]

The drawing is a sectional view of a grinding wheel showing an embodiment of the present invention. 1...Main abrasive grain, 2...Auxiliary abrasive grain, 3...Binding material.

Claims (1)

[Claims] The main abrasive grains that act on the grinding fill and the auxiliary abrasive grains made of hot-pressed silicon nitride (stsNt), which have a particle size equal to or smaller than the main abrasive grain size, are sintered together with a binder. A grinding wheel featuring: