JPH0739076B2 - Truing / dressing equipment - Google Patents

Description

The present invention relates to a device for truing and dressing a metal bond grindstone used for grinding.

(Prior Art) In the grinding process, the truing of the grindstone (correction of center deviation, correction of flatness) is an essential work to eliminate vibration of the processing machine and chatter marks on the processing surface, and to perform high-precision processing.

(Problems to be Solved by the Invention) However, since the metal bond grindstone has extremely high strength and high hardness as compared with a general grindstone, the processing efficiency becomes poor when the above-mentioned truing is performed. In particular, when truing a grindstone used for flat surface polishing such as lapping as shown in FIG. 3 on a processing machine, since the grindstone area is large, pressure is applied while rotating the truing grindstone 2'to the grindstone 1 '. The conventional general method of cutting or cutting has a problem that the truing efficiency is low and it takes a very long time.

Further, as another conventional example, there is a grindstone forming method as disclosed in, for example, JP-A-62-28172.

This grindstone forming method is a method of forming a grindstone by electric discharge, and adopts a configuration such as using a WA or GC grindstone as a truing grindstone, which has no dressing effect, has poor truing efficiency, and is highly efficient. There was a problem that I could not do it.

The present invention has been proposed in view of the above problems, and an object of the present invention is to provide a truing / dressing device capable of improving truing efficiency and maintaining the sharpness of a truing grindstone.

(Means for Solving the Problems) The present invention is a truing / dressing apparatus including a truing grindstone in which abrasive grains such as diamond and CBN are held by a metal bond, in which the truing grindstone is one electrode, and A truing grindstone and the other electrode are provided so as to face the trued wheel to be trued, and a voltage applying means for applying a voltage between the both electrodes, and a working liquid supply means for supplying a working liquid between the both electrodes and between the both whetstones. The above-mentioned object is achieved by providing the processing liquid between the two grindstones and mixing the free abrasive grains.

(Operation) The present invention is configured as described above, and when truing a high-strength, high-hardness metal bond grindstone, an electrolytic action is applied to the truing grindstone to elute the bond material and truing, thereby performing grinding and electrolysis. Both actions enable highly efficient processing.

At the same time, loose abrasive grains are mixed into the truing grindstone side, and the truing grindstone is dressed by the mutual rubbing effect of the grindstones.

(Embodiment) FIG. 1 shows an embodiment of the present invention, which is applied to a flat polishing machine used for lapping and the like.

In the figure, reference numeral 1 is a rotatable truing grindstone corresponding to a polishing disk, which is provided with a central axis 1a on the lower surface and rotates around the central axis 1a. An abrasive grain layer 1b in which grains are bonded by metal bonds is provided. Above the abrasive grain layer 1b, a truing grindstone 2 having an abrasive grain layer 2b on the lower surface is rotated, and a rotary shaft 2a of a device having a pressurizing mechanism is fixed, whereby the truing target grindstone 1 is provided. Is configured to perform the processing.

In consideration of the processing efficiency during truing and the consumption of the grindstone, the material of the truing grindstone 2 is a metal bond diamond grindstone, and the abrasive grains having a coarser mesh than the trued grindstone 1 are used.

On the other hand, the electrolysis device is provided separately from the truing portion, and the anode of the electrolysis power source 3 brings the (+) side power supply brush 4 into contact with the grindstone base metal portion to make the entire grindstone surface the anode. On the other hand, the cathode is made of a fan-shaped material such as copper or graphite, and is placed so as to face the abrasive grain layer 1b and be spaced at regular intervals. Further, an electrolytic solution flow hose 5 is connected to the cathode plate 6, so that the electrolytic solution is ejected from the cathode plate 6 so that a space between the truing grindstone 1 and the cathode plate 6 is filled with a processing liquid 7 made of the electrolytic solution. Has become. In addition, the same machining liquid 7 is flowed to the machining point during truing to provide cooling and lubricating effects during machining. In this embodiment, a water-soluble grinding fluid having conductivity is used as the working fluid 7.

The electrolysis power supply 3 is of a type that outputs a direct current or a pulse wave, and is provided separately from the processing machine, and controls the electrical conditions so as to obtain appropriate electrolysis conditions.

Then, in operation, after each device is installed as described above, the truing grindstone 1 rotates at a low speed, the truing grindstone 2 rotates at a high speed, and the truing grindstone 1 is pressed (cut) to the cathode. And processing liquid 7 for processing point
And the switch of the electrolytic power source 3 is turned on. Further, loose abrasive grains 9 such as alumina and silicon carbide are mixed into the processing point through the hose 8 and the truing grindstone 2 is simultaneously dressed (dressed) by the mutual rubbing effect of the grindstones.

In this embodiment, dressing is performed by mixing loose abrasive grains 9, but this is trued by the truing stone 2
A block such as WA may be pressed against the grindstone at a portion that does not contribute to the machining, or a dressing method by electrolysis similar to that for the truing grindstone 1 may be used.

Then, the truing grindstone 1 causes the elution of the bond material due to the electrolytic action, but after a certain amount of time elapses, the surface of the grindstone a bonded by the bond material c becomes the mother material as shown in FIG. 2 (b). It is covered with the non-conductive film b of metal oxide having a lower strength than the ground strength, and the electrolytic action does not proceed. However, since the oxide film on the convex portion of the truing grindstone 1 is scraped off by the truing grindstone 2, grinding and electrolysis act on the convex portion at the same time, and it is processed more than twice as efficiently as usual. It On the contrary, since neither the grinding nor the electrolysis acts on the grindstone concave portion, the grindstone is not reduced in size.
In this way, only the convex portion of the truing grindstone 1 is selectively and efficiently processed.

This method is effective because the smaller the grain size of the truing grindstone 1, the smaller the processing resistance of the truing grindstone 2 with the diamond.

Further, the collected loose abrasive grains are collected by a paper filter or a centrifuge so that scratches such as scratches are not generated when the work is processed.

Further, the dressing of the truing grindstone 1 after the completion of the truing can be performed by stopping the processing by the truing grindstone 2 and allowing only the electrolysis to continue to act.

As described above, according to the present invention, the truing grindstone is used as one electrode, the truing grindstone and the other electrode are provided to face the truing grindstone, and a voltage is applied between the two electrodes. By providing a voltage applying means and a machining fluid supply means for supplying a machining fluid between the both electrodes and between the both grindstones, and by making the free abrasive grains mixed into the machining fluid between the both grindstones, (1 ) Truing is performed by both the action of grinding and electrolysis, so even a large-area, high-hardness whetstone can be effectively trued.

In addition, since the grindstone is formed by electrolysis, the surface of the truing grindstone is less rough, and the truing grindstone is not affected by heat.

(2) Since dressing of the truing grindstone is also performed during processing and the processing is not interrupted, the processing efficiency is not reduced.

(3) After the truing is completed, the grinding stone is removed by removing the truing grindstone, and only the electrolysis is continued, which is very efficient.

And so on.

(4) Since a metal bond grindstone is used for the truing grindstone, the grindstone consumption is small and the truing can be performed with high accuracy. Further, since the abrasive grains are firmly held, the processing efficiency is high.

[Brief description of drawings]

FIG. 1 is an explanatory view of the configuration of an embodiment of the present invention, and FIG. 2 is a schematic view showing the surface state of a truing grindstone. (A) is a normal state, (b) is an oxide film and is electrolyzed. FIG. 3 shows a conventional example in which truing is performed on the grindstone of the flat surface polishing apparatus in the state where the process does not proceed. 1 ... Trued wheel, 1a ... rotation axis, 1b ... abrasive layer, 2 ... truing wheel, 2a ... rotation axis, 3 ...
Power supply for electrolysis, 4 ... Power supply brush, 5, 8 ... Hose, 6 ...
… Cathode plate, 7 …… Processing fluid, 9 …… Free abrasive grains.

Claims (1)

[Claims] 1. A truing / dressing apparatus equipped with a truing grindstone in which abrasive grains such as diamond and CBN are held by a metal bond. A grindstone and the other electrode are provided, a voltage applying means for applying a voltage between the both electrodes, and a working liquid supply means for supplying a working liquid between the both electrodes and between the both grindstones are provided, and machining between the both grindstones is performed. A truing / dressing device characterized in that free abrasive particles are mixed into a liquid.