JPH0453628A - Grinding fluid for electrolytic dressing - Google Patents

Abstract

PURPOSE:To prevent metallic oxide from being educed on a grinding wheel surface as well as to prevent a machine body so from corrosion by adding such a material as to form a complex ion and a chelate, to a grinding fluid made up of mixing a metal rust preventive, a surfactant an antifoamer, a trace electrolyte or the like. CONSTITUTION:In a grinding fluid in use on the grinding of electrolytic dressing for a metal bonded grinding wheel, it is made up of adding such a material as to form a complexion or a chelate, to the grinding fluid mixed with a metal rust preventive, a surface active agent, an antifoamer, a trace electrolyte or the like. In addition, a halide salt such as NaCl, KCl or the like is added to the grinding fluid made up of mixing the metal rust preventive, surface active agent, antifoamer, etc., and constituted. Since a nonconductive film is not produced at all, there is no drop in dressing efficiency, so that stable electrolytic dressing is realizable, and likewise a grain size projecting quantity also is not reduced, thus high efficient dressing operation can be actualized and, what is more, there is no fear of mechanical corrosion.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a water-soluble electrolytic dressing grinding fluid used for electrolytic dressing in which a grindstone used for grinding is dressed (sharpened) by applying an electrolytic action to the grindstone.

(Conventional technology) Lubrication and cooling of the grinding wheel and workpiece during grinding.

And grinding fluid is used for cleaning.

This grinding fluid can be divided into water-soluble and water-insoluble (oil-based) types, but in recent years, water-soluble grinding fluids have been widely used for disaster prevention purposes as they do not pose a risk of fire and provide a good working environment.

However, water-soluble grinding fluid contains oil, fat, and metal rust inhibitors.

It is a mixture of surfactant, antifoaming agent, extreme pressure agent, preservative, etc. in the required amount depending on the purpose, and the water-soluble grinding fluid is usually diluted with water to 10 to 100 times. It will be done.

Further, the functions necessary for the grinding fluid are as follows.

■ Has lubrication and cooling properties to improve grinding performance ■ Will not corrode metals or workpieces used in the machine body.

■ Contains no substances harmful to the human body.

However, grinding wheels are made by hardening abrasive grains such as diamond or CBH with a binder such as resin, ceramic material, or metal.

For this reason, as machining progresses, chips adhere between the abrasive grains (
The abrasive grains become clogged (clogged), the tips of the abrasive grains wear out and become flat (clogged grains), and the abrasive grains fall off from the binder (spilled grains), which reduces the sharpness of the abrasive grains and increases grinding resistance. , or the grinding wheel and the rigid material may seize.

Therefore, it is necessary to stop the machine at regular intervals and perform dressing to restore the sharpness of the grindstone.

In this case, conventionally -A has a low degree of bonding.

A common method is to perform dressing by grinding with a grindstone such as GC, and it is necessary to interrupt the processing once.

In other words, as shown in Figure 2, a conductive metal bonded grinding wheel is used, the grinding wheel side is set to +, the electrode provided opposite to the grinding wheel is set to -, and a water-soluble grinding fluid containing an electrolyte is placed between them. is applied, and then a direct current or a pulsed current is applied to selectively elute only the grinding wheel binder, thereby dressing the grinding wheel.

This method allows constant dressing during processing,
By controlling the electrical conditions, it is possible to apply it to anything from rough grinding wheels to mirror grinding wheels, and the effect of electrolytic dressing is to protrude abrasive grains and remove chips.

In addition, in the figure, 1 is the grinding wheel alloy, 1b is the abrasive grain layer, 2 is the work material,
3 is a pressure plate, 4 is a power supply, 5 is a power supply brush, 6 is one electrode, and 7 is a nozzle for spouting the grinding fluid 8.

(Problems to be Solved by the Invention) When electrolytic dressing is performed using a water-soluble grinding fluid as a machining fluid with the configuration shown in Figure 2, diamond a is originally formed on the surface as shown in Figure 3 (a). It is desirable to have a good protruding state, but due to the polarization effect on the anode side, Φ)
As shown in Figure 2, a nonconducting film such as metal oxide is formed on the grinding wheel surface, and the dressing efficiency is decreased due to a decrease in the electrolytic current value.

■ There is a problem of a decrease in processing efficiency due to a decrease in the amount of abrasive grains protruding.

Furthermore, when sodium chloride, sodium nitrate, or the like used in electrolytic machining is used as a grinding fluid, the dressing efficiency is increased, but there is a problem in that it corrodes the machine body.

The present invention was proposed in view of the above, and its purpose is to prevent metal oxides (nonconductor film) from being deposited on the surface of the grinding wheel during electrolytic dressing and to prevent corrosion of the machine body. An object of the present invention is to provide a water-soluble grinding fluid for electrolytic dressing.

(Means for Solving the Problems) In the present invention, in the grinding fluid used for electrolytic dressing grinding processing in which a metal bond grindstone is dressed using electrolytic action, a metal rust preventive agent, a surfactant, an antifoaming agent, and a trace amount of The above object is achieved by adding a substance that generates complex ions or chelates to a grinding fluid containing an electrolyte and the like.

In addition, in the grinding fluid used for electrolytic dressing grinding, which uses electrolytic action to dress the metal bond grinding wheel, halogens such as NaC1% MCI are added to the grinding fluid containing metal rust preventive agents, surfactants, antifoaming agents, etc. By adding a compound salt to the composition, the above object is achieved.

(Function) The present invention is configured as described above, and a grinding wheel binder is added to a water-soluble grinding fluid containing conventional metal rust preventive agents, surfactants, antifoaming agents, extreme pressure agents, preservatives, trace electrolytes, etc. By mixing a substance that forms a complex with metal ions that are eluted from the grinding wheel, a nonconducting film is not formed on the surface of the grinding wheel, and the main body of the machine is not corroded.

In addition, a water-soluble grinding fluid containing conventional metal rust preventive agents, surfactants, antifoaming agents, extreme pressure agents, preservatives, etc., has a weight concentration of 0.01.
By adding ~1% of halogen compound salts such as NaCl and KCl, a nonconductive film is not formed on the surface of the grinding wheel, and the machine body is prevented from being corroded.

(Example 1) The complex-forming substance used in the grinding fluid of this example has: (1) a formation constant larger than that of the reaction between hydroxide and metal ions;

■ Reacts under alkaline conditions.

■ No negative effects on the human body.

■ It is water soluble.

■ The machine body is not corrosive.

■ Cheap and easy to handle.

This is very important.

For example, if the grinding wheel binder is cast iron, diethylenetriaminepentaacetic acid (DTPA), ethylenediamine diacetic acid M (EDDA), ethylenediaminetetraacetic acid (E
DTA) (1) Substances such as 10-phenanthrolinthioglycolic acid 2,2'-bipyridine form stable complexes with eluted iron ions.

FIG. 1 shows a schematic diagram of the present invention, and will be explained using an example in which the grinding wheel binder is cast iron and the complex forming substance is EDTA.

In other words, the iron ions on the surface of the grinding wheel are electrolyzed,
It becomes ions and elutes into the liquid.

Conventionally, hydroxide ions react with these iron ions, and Fe
(OR)z turns into Fe(OR)s and Fezes and adheres to the surface of the grindstone as a nonconducting film, causing an obstruction to the electrolytic action.

Since EDTA has a larger production constant than hydroxide, it coordinates with iron ions before hydroxide ions, forming a stable complex ion. This compound of EDTA and iron is an ion and has conductivity, so the surface of the grindstone does not become nonconductive.

Furthermore, since EDTA reacts with the molar ratio of iron ions and tit, it is sufficient to predict the amount of iron ions to be eluted in advance and mix in more EDTA than that amount.

The blending ratio of the water-soluble grinding fluid used in this example is as follows.

Rust inhibitor Alkanolamine 15-30% (wt%
)〃 Carbonate 3-10% borate
3~10% Corrosion inhibitor Triazole type 0.1~3% ED
TA l～～10% antifoaming agent, extreme pressure additive
Trace amount Others Water 37~~78%However,
The spirit of the present invention is not limited to the above-mentioned substances and mixing ranges.

However, the above stock solution was diluted 50 times with water, and the corrosive and
Electrolytic dressing properties were evaluated.

(1) Corrosion test material: Cast iron FC20 (o20xtlO) solution: ■ Above solution ■ EDTA removed from the above solution ■ Electrolytic machining fluid MCI (1χ-t) Method 2 Cast iron is immersed in the above three types of solutions, and water Keep at 50°C in the bath for 10
It was left for 0 hr.

Measure the weight before and after the test to determine whether it is due to corrosion. The amount of weight loss was determined.

Results: The amount of weight loss for solutions (1) and (2) was both 3-g or less, which was good, and for solution (2), a weight loss of 30 mg was observed.

(2) Electrolytic dressing test whetstone: Cast iron bond whetstone 501200 Concentration level 5o
φ5° solution: same three types of electrode G used in the corrosion test
AP: 0.1 Tie score: 300 rpm Applied voltage = 90v Setting current: 24A (at short circuit) On time, off time = 4μsec, 4μ5ec (
Pulse wave) Method: Dressing was performed for 15 minutes, the weight before and after processing was measured, and the amount of dressing was determined.

Results: Solution ■ -5% Solution with film formation ■ -10% Solution without film formation ■ -100% Black sludge generation The grinding fluid of the present invention is inferior to the electrolytic machining fluid in terms of electrolytic dressing efficiency, but the abrasive grains do not stick out during dressing. Since the elution amount may be approximately 1 to 30 .mu.m, there is no problem even if the electrolytic efficiency is not 100% (as long as no film is deposited).

From the above results, it was found that the grinding fluid of this example is very effective because it does not cause corrosion of the machine and does not generate a nonconductive film during electrolytic dressing.

It has also been found that similar results can be obtained with other complex-forming substances.

In the above embodiments, since no nonconductive film is generated, the dressing efficiency is not reduced and stable electrolytic dressing can be achieved. Furthermore, since the amount of abrasive grain protrusion does not decrease, efficient machining can be achieved. Furthermore, there is no need to worry about mechanical corrosion.

(Example 2) The halide salts used in the main grinding fluid of this example include NaCl, KCI, NaF, Kl, and KBr.
etc., but chloride is the most common.

It is generally known that chlorine ions destroy nonconductor films and do not reduce electrolytic efficiency.

Additionally, if high concentrations of chlorine ions are added, corrosion of the machine body is unavoidable.

When chloride is added, metal elution occurs with a current efficiency of 100%, so by controlling the current value, it becomes very easy to control the amount of abrasive grain protrusion.

Therefore, from the components of the water-soluble grinding fluid shown in the first example of addition of complex reactants, excluding EDTA, diluted 50 times with water and adding 0.01 to 1% to the solution. The results of a similar confirmation test using the added grinding fluid are shown.

(1) Corrosion The amount of corrosion is about twice that of the grinding fluid without KCI added, and the corrosivity is slightly inferior, but this level is within an acceptable range.

(2) The electrolytic efficiency is 100%, which corresponds to the amount of electrolytic elution obtained from Faraday's law, which is very good.

From the above results, it was found that the grinding fluid of this example is very effective because it does not cause corrosion of the machine and the electrolytic dressing efficiency is also good.

(Effects of the Invention) As described above, in the present invention, in the grinding fluid used for electrolytic dressing grinding processing in which a metal bond grinding wheel is dressed using electrolytic action, a metal rust preventive agent, a surfactant, an antifoaming agent, Since it is made by adding a complex ion or chelate-forming substance to the grinding fluid containing a small amount of electrolyte, (1) no nonconducting film is generated, so dressing efficiency does not decrease and stable electrolytic dressing can be achieved.

(2) Since the amount of abrasive grain protrusion does not decrease, highly efficient machining can be achieved.

(3) There is no need to worry about mechanical corrosion.

In addition, in the grinding fluid used for electrolytic dressing grinding processing, which uses electrolytic action to dress metal bonded grinding wheels, eNac1, a grinding fluid containing metal rust preventive agents, surfactants, antifoaming agents, etc., is mixed with halogens such as C1. Similarly, according to the present invention in which a compound salt is added, (1) Since no nonconducting film is generated, the dressing efficiency is not reduced and stable electrolytic dressing can be realized.

C) There is no need to worry about mechanical corrosion.

(3) Since it flows out with 100% electrolytic efficiency, it is very easy to control the amount of abrasive grain protrusion.

There is an effect like this.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the first embodiment of the present invention, Fig. 2 is an explanatory diagram showing the state of electrolytic dressing, Fig. 3 (a) is an explanatory diagram showing a good grinding wheel surface due to electrolytic dressing, (b) indicates a state in which the surface is covered with a nonconducting film. Figure 1

Claims (2)

[Claims] (1) In the grinding fluid used in the electrolytic dressing grinding process, which uses electrolytic action to dress the metal bond grinding wheel, complex ions are added to the grinding fluid containing metal rust preventive agents, surfactants, antifoaming agents, trace electrolytes, etc. Alternatively, a grinding fluid for electrolytic dressing is characterized in that it contains a substance that generates chelate. (2) In the grinding fluid used for electrolytic dressing grinding, which uses electrolytic action to dress the metal bond grinding wheel, NaCl, KCl, etc. A grinding fluid for electrolytic dressing characterized by containing a halide salt.