JP3886801B2 - Grinding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grinding method.
[0002]
[Prior art]
In the current grinding process, a method of performing a process while supplying a grinding fluid to a contact point (a part being processed) between a grindstone and a workpiece is the mainstream. The purpose of supplying the grinding fluid is mainly cooling (removing frictional heat) and removing chips. Grinding oils are mainly composed of mineral oil, animal oil, vegetable oil, ester oil and the like, and include water-insoluble grinding oils that are used without being diluted with water and water-soluble grinding oils that are used after being diluted with water. The reason for using grinding oil instead of water is to improve lubricity, wettability, and permeability.
[0003]
[Problems to be solved by the invention]
Traditionally, this method has been used for the processing of relatively hard metals such as iron. However, it has been extremely difficult to process workpieces (hereinafter referred to as “difficult-to-process materials”) such as copper, which is in great demand as an electrode for electric discharge machines, inconel used for mold materials, and plastics. The following (1) and (2) can be given as the reason.
(1) Whetstone clogging:
With these difficult-to-process materials, chips (grinding debris) tend to adhere to the surface of the grindstone or blade, causing clogging immediately and making it impossible to process. Wheel clogging also occurs when grinding iron or the like, and the wheel is regenerated (dressing) in a timely manner, but the frequency is not high. However, in difficult-to-process materials, it is necessary to regenerate the grinding wheel frequently due to clogging, and finishing with a fine-grained grindstone is extremely difficult.
(2) Finish:
Even if grinding is performed with a rough grindstone to prevent clogging, the finished surface becomes rough (rough) due to clogging of chips and grindstones that have reattached to the surface of the workpiece.
[0004]
The first object of the present invention is to make it difficult to cause clogging of the grindstone, reduce the frequency of regeneration (dressing) of the grindstone, and realize the use of a fine grindstone. The object is to prevent grinding dust (chips) from adhering to the new surface produced by grinding the workpiece and to prevent clogging of the grindstone to improve the processing accuracy of the finished surface.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the above object, a grinding method according to the present invention includes a gas separation membrane that separates N ₂ gas and O ₂ gas from air at a portion of a workpiece being ground. the O ₂ concentration of 25% to 40% and the oxygen-enriched gas using a module, and feed subjected to grinding oil co, new surface appeared to the surface of the newly workpiece by the grinding, and the grinding In this method, oxygen molecule adsorption on the scrap surface is promoted or oxidized, and the new surface and the grinding scrap surface are inactivated while being ground .
Your name, the O ₂ concentration is indicated by the volume%.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the following, embodiments of the present invention will be described. In a grinding process by a grinder, a workpiece--especially, a relatively soft metal such as copper, an inconel of a mold material, or a difficult-to-process material such as plastic. ─── is a method of supplying oxygen-enriched gas together with grinding oil to the part being processed by contacting with a rotating grindstone (grinder). In other words, it is a method in which an oxygen-enriched gas is entrained in a grinding oil agent and sprayed or jetted or flowed to the contact point between the workpiece and the rotating grindstone—the grinding point—and the vicinity thereof.
[0007]
The oxygen-enriched gas to be supplied, O ₂ concentration shall be the ones 25% to 40%. In particular, 28% to 35% is desirable. If it is less than the lower limit, the deactivation of the new surface and grinding scrap surface described later will be insufficient, and conversely, if the upper limit is exceeded, it will be difficult to obtain such a high O ₂ concentration gas at low cost. The oxidation of the new surface becomes excessive and becomes a problem.
[0008]
FIG. 1 shows an example of an apparatus for producing such an oxygen-enriched gas. That is, it is an apparatus using the gas separation membrane module M, and the compressed air is supplied into the container 2 from the direction of the arrow A, and the hollow separation membrane 1 that is more permeable to O ₂ gas than N ₂ gas is stretched. In the installed container 2, N ₂ gas and O ₂ gas are separated from air.
Arrow B indicates the discharge direction of O ₂ gas (oxygen-enriched gas), and arrow C indicates the discharge direction of N ₂ gas (nitrogen-enriched gas).
[0009]
The grinding method according to the present invention will be described in more detail. A surface that is newly appeared on the surface of a workpiece by supplying oxygen-enriched gas together with a grinding oil to a portion of the workpiece during grinding. ─── “Renewed surface” ─── and promoting the adsorption of oxygen molecules on the grinding scrap surface and the abrasive grains, etc., or oxidizing them to inactivate the new surface and grinding scrap surface, etc. It can be said that this is a grinding method.
[0010]
In other words, during grinding, the surface of the workpiece that has been ground with a grindstone, and the surface of the grinding scraps that have been scraped are newly emerging from the inside of the metal to the surface-the new surface- The activity is remarkably high compared to a normal surface. When the activity is high, grinding scraps and abrasive powders are likely to adhere to the workpiece surface. However, it is considered that by supplying the oxygen-enriched gas, the oxidation of the new surface or the adsorption of oxygen molecules on the new surface is promoted and can be inactivated.
[0011]
In addition, the metal surface around us is usually already covered with an oxide film so that it does not stick to other things. However, the new surface after processing is in a state where the bonds between the atoms constituting the metal are broken, and easily bonds with the substance in contact therewith. This is considered to be the reason why the new surface is active and easy to adhere.
[0012]
As described above, in the present invention, by deactivating the new surface of the workpiece and the new surface of the grinding scrap during grinding, the grinding scrap can be quickly eliminated and the processing surface can be damaged. The processing accuracy increases. Moreover, grinding scraps are less likely to adhere to the grinding wheel side, clogging of the grinding stone is almost eliminated, processing accuracy is further improved, and grinding of copper, plastics, etc. has been difficult or impossible so far. You can now grind the materials you have.
[0013]
As an example, an oxygen-enriched gas having an O ₂ concentration of 30% was used, and tungsten copper was ground using a CBN wheel, No. 180 as a fine grindstone, but clogging did not occur. Since re-adhesion of grinding scrap does not occur, a machined surface with significantly higher accuracy than before was obtained.
[0014]
Conventionally, a grinding method using a nitrogen-enriched gas has been proposed in dry grinding without using a grinding oil, but the present invention uses a gas that is wet and has a high O ₂ concentration. In this respect, the invention is completely based on a novel idea.
[0015]
【The invention's effect】
The above-described configuration of the present invention provides the following remarkable effects .
Hardly occur clogging of abrasive stone, making it possible to use those having a small eye than conventional machining accuracy can be remarkably improved. In addition, the frequency of grinding wheel regeneration (dressing) can be reduced, the grinding work efficiency can be remarkably improved, and the implementation is easy.
In addition, it can prevent grinding scraps from adhering to the new surface caused by the grinding of the work piece, so that the processing accuracy of the finished surface can be improved and grinding of difficult-to-work materials such as copper and plastic, which has been considered difficult in the past. Can be done easily.
Moreover, a sufficient working accuracy, it is possible to obtain, oxygen-enriched gas required also accessible.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an example of an apparatus for producing an oxygen-enriched gas used in the present invention.
[Explanation of symbols]
M Gas separation membrane module 1 Hollow separation membrane 2 Container

Claims (1)

The site in the grinding of the workpiece, the O ₂ concentration of 25% to 40% and the oxygen-enriched gas using a gas separation membrane module M for separating the N ₂ gas and O ₂ gas from the air, Grinding subjected feeding the oil and co, new surface appeared to the surface of the newly workpiece by the grinding, and, to the grinding dust surface, it promotes oxygen molecules adsorbed to be oxidized, the new surface and grinding dust surface Grinding method, characterized in that grinding is performed while inactivating the material .

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