JPH07195269A - Pretreatment method of resinoid bonded wheel - Google Patents

Abstract

PURPOSE:To provide a pretreatment method that consists of two truing and dressing processes necessary at the time of using a resinoid bonded wheel being available in a grinding machine or the like and containing a diamond abrasive grain or CBN abrasive grain, rounding off them as one process. CONSTITUTION:This is a pretreatment for a resinoid bonded wheel A with an abrasive grain layer 4 made up of holding abrasive grains consisting of diamond or CBN with a binder being composed of resinoid bond. Before grinding operations by this resinoid bonded wheel A, a copper block 6 is ground by this wheel A. With the copper block 6 ground by it, the excessive abrasive grain layer 4 or the wheel A is shaved off, while abrasive grains are projected out of the layer 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when using a resin grindstone using diamond abrasive grains and CBN (cubic boron nitride) abrasive grains, grinds excess portions of the surface of the resin grindstone in advance, and The present invention relates to a pretreatment method for a resin grindstone in which abrasive grains are projected onto the surface of the grindstone.

[0002]

2. Description of the Related Art Generally, a grindstone using diamond abrasive grains or CBN abrasive grains is used for grinding and polishing a hard substance with a grinder. The grindstone is, for example, as shown in FIG.
As in the straight grindstone shown in FIG. 1, an abrasive grain layer 4 composed of abrasive grains 2 ... And a binder 3 holding these abrasive grains 2 ... Is formed on the outer peripheral surface of a substantially disk-shaped base metal 1. is there. Then, the grindstone is attached to a grinder and rotated to be used for grinding / polishing. The shape of the grindstone includes various shapes such as a cup-shaped grindstone other than the straight grindstone.

Further, there are the following types of the grindstones depending on the type of the binder. For example, a resinoid bond grindstone (resin grindstone) using an organic bond mainly composed of thermosetting phenol-formalin resin or polyimide resin, a binder made of an alloy of copper, tin, tungsten carbide, iron, nickel, etc. The metal bond grindstone used, a porcelain sintered at 800 ° C. to 1,000 ° C., a vitrified bond grindstone using an inorganic binder such as glass, and an electrodeposition bond grindstone for fixing abrasive grains by an electroplating method.

When using these grindstones, if the center of the grindstone circumference is deviated from the spindle axis or if the grindstone circumference is not a perfect circle, only a part of the grindstone outer periphery is ground. However, the whetstone is shaken and adversely affects the grinding. Therefore, in the grindstone, as a pretreatment step, it is necessary to scrape off the excess part of the abrasive grain layer in order to make a perfect circle in the circumferential part of the grindstone. In the diamond grindstone and the CBN grindstone, the operation of cutting the surface of the abrasive grain layer as described above is called "trueing".

Conventionally, as a pre-treatment for grinding wheels, a single stone dresser (made of natural diamond), an implied dresser (metal bond tool in which diamond abrasive grains are randomly arranged), and a brake are used. Controlled Truing Equipment (equipment with GC (silicon carbide) and WA (alumina) wheels)
, A mild steel grinding method (which grinds mild steel), a grindstone grinding method (which uses a GC grindstone or a WA grindstone), a block dresser method (which uses an electrodeposited diamond grindstone), and the like.

[0006]

By the way, after carrying out the above-mentioned trueing, both the binder and the abrasive grains are scraped off by the trueing, and the diamond grindstone and the CBN grindstone have no chip pockets called pores. For this reason, the surfaces of diamond and CBN wheels are
It is often in a slippery state with almost no protrusion of abrasive grains. Therefore, in the above-mentioned grindstone, it is necessary to make the abrasive grains protrude from the binder of the above-mentioned abrasive grain layer and effectively provide chip pockets so as to have a grinding ability as the grindstone.
That is, when using the grindstone, it is necessary to perform a grindstone dressing operation as a pretreatment step.

In the grindstone, such dressing work is called "dressing" and is clearly distinguished from the "trueing". As the dressing method, a stick-shaped WA grindstone or a GC grindstone is cut into the grindstone, or a steel block or a roll is brought into contact with the rotating grindstone, while free abrasive grains of WA or GC are added. There is a method of pouring it together with a grinding oil or the like.

As described above, in the case of the grindstone using the diamond abrasive grains or the CBN abrasive grains, it is necessary to perform both the touring and the dressing as the pretreatment before use, so that the pretreatment of the grinding is complicated. In addition to the above, there is a problem that it takes time from the mounting of a new diamond grindstone or CBN grindstone to the grinder until the actual grinding work.

The present invention has been made in view of the above circumstances, and simplifies the pretreatment step when a new resin grindstone is used in the resin grindstones of the grindstones using the diamond abrasive grains or the CBN abrasive grains. In addition, it is an object of the present invention to provide a pretreatment method for a resin grindstone that can reduce the time required for the pretreatment process.

[0010]

SUMMARY OF THE INVENTION A method for trueing and dressing a resin grindstone according to the present invention is to machine a grinding machine using a resin grindstone having an abrasive grain layer in which diamond abrasive grains or CBN abrasive grains are held by a resinoid bond. Grinding a copper block using the resin grindstone before performing a grinding operation with a machine was a means for solving the above problems. Further, it is preferable that the copper block contains 99.9% or more of copper.

[0011]

According to the above construction, as in the conventional truing method, by rotating the resin grindstone to grind the copper block, the excess portion of the resin grindstone is scraped off and the abrasive grains of the abrasive grain layer of the resin grindstone. Are projected from the binder. Therefore, the pretreatment process of the resin grindstone, which has conventionally required two processes of trueing and dressing, can be made into one process for grinding the copper block.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a drawing for explaining a pretreatment method for a resin grindstone of this embodiment, showing a straight resin grindstone A attached to a grinder (a part of which is schematically shown in FIG. 1) B. is there. The resin grindstone A processed by the method for pretreating the resin grindstone of this embodiment has diamond or CBN abrasive grains 2 (shown in FIG. 2) similarly to the straight resin grindstone shown in FIG. 2 of the conventional example. An abrasive grain layer 4 held by a resinoid bond (binder 3 shown in FIG. 2) mainly composed of phenol formalin resin or polyimide resin is formed on the outer peripheral portion of the base metal 1.

In the resin grindstone pretreatment method of this embodiment, first, the resin grindstone A formed as described above is set on the grinder B. Next, the copper block 6 made of copper and in the shape of a rectangular parallelepiped is fixed on the table 5 of the grinding machine B. Then, the resin grindstone A set on the table 5 is rotated and moved downward to grind the surface of the copper block 6. The copper of the copper block 6 is preferably made of high-purity copper. Further, the copper content of the copper in the copper block 6 is preferably 99.90% or more. For example, in the resin grindstone pretreatment method of this embodiment, the copper purity of the copper block 6 is copper. Alloy number C1100 with 99.90% or higher alloy number C1100 or alloy number C10 with 99.96% or higher purity copper
20 oxygen-free copper etc. can be used conveniently.

By grinding the copper block 6 with the rotating resin grindstone A, the surface of the resin grindstone A is scraped off. At this time, resin grindstone A
On the outer peripheral surface of the abrasive grain layer 4 on the outer periphery of, the portion farther from the rotation center of the resin grindstone A, that is, the protruding portion of the outer peripheral surface of the resin grindstone A is scraped off first, and the center of the resin grindstone A and the center of rotation are As it approaches, the shape of the resin grindstone A approaches a perfect circle. Therefore, the shake of the resin grindstone A in the grinder B can be prevented.

Further, the outer surface of the abrasive grain layer 4 of the resin grindstone A scraped off by grinding the copper block 6 is in a state in which the abrasive grains 2 are projected from the surface of the binder 3 of the abrasive grain layer 4. Thus, the grinding ability of the grindstone is achieved.
That is, the surface of the resin grindstone A is sharpened.

Here, the experimental results of actually grinding the copper block 6 with the resin grindstone A will be described. As the copper block 6, the copper block 6 made of the tough pitch copper was used. Then, as described above, the resin grindstone A
When the surface of the copper block 6 was ground by the method, it was confirmed that the grinding of the resin grindstone A disappeared by grinding for 5 to 10 minutes, and the resin grindstone A was shaped into a substantially perfect circle.

When the surface of the abrasive grain layer 4 of the resin grindstone A was observed, it was found that the abrasive grains 2 were in a protruding state and could be sufficiently ground. In the conventional pretreatment of the resin grindstone A, it took at least 30 minutes to perform both the steps of trueing and dressing. Therefore, the conventional pretreatment method is replaced with the method of grinding the copper block 6. As a result, the processing time can be significantly reduced.

Further, the same experiment was conducted using an aluminum block and a copper-tungsten alloy block. When these blocks were ground with the resin grindstone A as described above, unlike the case where the copper block 6 made of high-purity copper was ground, protrusions of the abrasive grains 2 were not seen so much on the surface of the resin grindstone A. However, it was not ready for grinding. Further, when the aluminum block was used, aluminum powder generated by grinding adhered to the surface of the abrasive grain layer 4 of the resin grindstone A, causing clogging.

As described above, in the resin grindstone A, by grinding the high-purity copper block 6, the resin grindstone A can be made into a perfect circle and at the same time sharpened. It is possible to obtain the same effect as the two steps of trueing and dressing. Although the mechanism of action of the resin grindstone A in the abrasive grain layer 4 when the copper block 6 is ground cannot be clarified here, it can be estimated as follows.

When the copper block 6 is ground with the resin grindstone A, the abrasive grains 2 of the abrasive grain layer 4 on the surface of the resin grindstone A ...
And the binder 3 is scraped off, but at this time, the abrasive grains 2 ... Of the abrasive grain layer 4 are crushed or fallen off, and the crushed or dropped abrasive grains 2 ... On the surface of the copper block 6. It will be stuck and stuck to the copper block 6. At this time, the surface of the copper block 6 will be scraped, but
The abrasive grains 2 are supplied from the resin grindstone A, and the abrasive grains 2 are always attached to the surface of the resin grindstone A.

Then, the abrasive grains 2 attached to the surface of the resin grindstone A are in a state of protruding from the surface of the copper block 6, and conversely, the abrasive grain layer 4 of the resin grindstone A is ground. The unstable abrasive grains 2 ... Only attached to the surface of the copper block 6 are similar to the loose abrasive grains described in the conventional example,
Of the abrasive grain layer 4 of the resin grindstone A, the portion of the binder 3 is mainly shaved. Then, the portion of the binder 3 of the abrasive grain layer 4 is shaved, so that the abrasive grains 2 are projected on the surface of the abrasive grain layer 4, and the grinding ability is added to the resin grindstone A. Become.

Further, as described above, the resin grindstone A can be ground only when the copper block 6 made of high-purity copper is ground, and other metals or copper alloys are ground. In this case, the resin grindstone A cannot be brought into a grindable state. It seems that physical properties such as hardness, elasticity, and viscosity of the high-purity copper are greatly related to this, and it affects the above-mentioned state of adhesion of the abrasive grains 2 to the surface of the copper block 6. I think that the.

Further, due to the mechanism of action different from the above assumption,
Even if the resin grindstone A is in a sharpened state, it is considered that the physical characteristics of copper different from other metals are involved in the sharpening of the resin grindstone A. Furthermore, in the case of copper having a purity of 99.9% or more, the uniformity and characteristics peculiar to copper are ensured by the fact that there are almost no impurities other than copper, and as shown in the above test results, the resin grindstone Can be surely finished in a high quality and sharpened state.

For reference, Table 1 shows the standard for oxygen-free copper (alloy No. C1020P), which is high-purity copper, and the actual test results of oxygen-free copper.

[Table 1]

As described above, according to the method of pretreating the resin grindstone of this embodiment, the excess portion of the abrasive grain layer 4 of the resin grindstone A is removed by grinding the copper block 6 as the pretreatment of the resin grindstone A. The resin grindstone A can be made into a perfect circle while the center of the resin grindstone A is aligned with the center of rotation of the resin grindstone A, and the resin grindstone A can be sharpened. Therefore, it is not necessary to perform dressing for projecting the abrasive grains 2 on the surface of the abrasive grain layer 4 after grinding the copper block 6, and the pretreatment of the resin grindstone A is performed only by grinding the copper block 6. It can be done in two steps. That is, the pretreatment process of the resin grindstone A can be simplified and the treatment time can be shortened.

Although the straight type resin grindstone A has been described in the above embodiment, the resin grindstone of the present invention can be used for the pretreatment for removing the excessive abrasive grain layer and for the sharpening even in the resin grindstones of other shapes. Needless to say, the pretreatment method of No. 1 can be used, and no matter what shape the resin grindstone has, the copper block 6
By grinding, the excess abrasive grain layer can be removed and dressed. Further, according to the method for pretreating the resin grindstone of the present invention, by changing the shape of the surface of the copper block 6, it is possible to sharpen the corner edge of the grindstone and correct the R shape of the surface of the abrasive grain layer. It can be carried out.

[0027]

As described above in detail, the first aspect of the present invention is as follows.
According to the pretreatment method of the resin grindstone described, as the pretreatment of the resin grindstone, by grinding the copper block, it is possible to scrape off the excess abrasive grain layer of the resin grindstone, and to grind the surface of the abrasive grain layer. The grains can be projected. That is, according to the present invention, since the pretreatment of the resin grindstone, which conventionally includes two steps of trueing and dressing, can be performed in one step of grinding the copper block, the pretreatment of the resin grindstone And the processing time can be shortened.

Further, according to the method for pretreatment of a resin grindstone according to claim 2 of the present invention, the above-mentioned effects are obtained, and
The copper block made of 99.9% or more copper with almost no impurities ensures that the resin grindstone can be sharpened with high quality.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a copper block is ground by a resin grindstone set on a grinder in the method for pretreatment of a resin grindstone according to the embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the conventional straight resin grindstone.

[Explanation of symbols]

 A Resin grindstone 2 Abrasive grain 3 Binder 4 Abrasive grain layer 6 Copper block

Claims (2)

[Claims] 1. Before performing grinding work with a machine tool such as a grinder using a resin grindstone having a grind layer in which diamond grits or CBN grits are held by a resinoid bond,
A method for pretreating a resin grindstone, which comprises grinding a copper block using the resin grindstone. 2. The pretreatment method for a resin grindstone according to claim 1, wherein the copper block contains 99.9% or more of copper.