Metal Working Fluid

Abstract

A first oil for metal working of the invention comprises an ester oil and a hydrocarbon oil with a kinematic viscosity of 1-20 mm2 / s at 40° C. A second oil for metal working of the invention employs an ester oil as the base oil and has a moisture content of 200-20,000 ppm. The first and second oils for metal working have excellent properties as water-insoluble oils for non-ferrous metal working and as oils for cutting and grinding in a minimum quantity lubrication system, and can therefore achieve improved working efficiency and extended tool life.

Description

TECHNICAL FIELD [0001] The present invention relates to an oil for metal working. BACKGROUND ART [0002] In cutting and grinding, it is common to employ cutting and grinding oils for the purpose of extending the life of working tools such as drills, mills, cutting tools, grinding wheels and the like, improving the surface roughness of working surfaces and raising productivity in mechanical working by increasing machining performance. [0003] Cutting and grinding oils fall into two general categories, water-soluble cutting and grinding oils used by diluting surfactants and lubricant components with water, and water-insoluble cutting and grinding oils used directly as stock solutions composed mainly of mineral oils. Generally speaking, water-insoluble cutting and grinding oils exhibit superior lubricating performance while water-soluble cutting and grinding oils exhibit superior cooling performance. [0004] Cutting and grinding oils that are effective for improving working efficiency hav...

AI Technical Summary

Benefits of technology

[0026] According to the invention, there is provided an oil for metal working that exhibits excellent properties as a water-insoluble oil for non-ferrous metal working and excellent properties as a cutting / grinding oil for a minimum quantity lubrication system, and that therefore allows improved working efficiency and extended tool life to be achieved.BRIEF EXPLANATION OF THE DRAWINGS

[0027]FIG. 1 is a schematic diagram showing an example of a machine tool suitable for use in a cutting / grinding method with a minimum quantity lubrication system.EXPLANATION OF SYMBOLS

[0028]1: Bed, 2: table, 3: workpiece, 11: tool, 12: oil feeding tank, 13: working oil feeding section, 14: sliding surface oil feeding section, 15: bearing oil feeding section, 16: sliding surface, 17: bearing section, 18: compressed air injection port.

Problems solved by technology

Cutting and grinding oils that are effective for improving working efficiency have drawbacks from other viewpoints, typically their adverse effects on the environment.

Whether water-insoluble or water-soluble, oils undergo gradual degradation with use and eventually become unusable.

In the case of water-soluble oils, for example, solution stability is lost with growth of microorganisms, resulting in separation of the components, a significantly fouled environment and unsuitability for use.

In the case of water-insoluble oils, progressive oxidation produces acidic components that corrode metal materials and produce significant changes in viscosity, also resulting in unsuitability for use.

The oils also adhere to cutting chips and the like, becoming consumed and forming waste.

Cutting and grinding oils containing no chlorine compounds have therefore been developed, but even such toxic substance-free cutting and grinding oils can adversely affect the environment with large-scale emission of waste products.

Water-soluble oils can also contaminate environmental waters and therefore require costly high-level treatment.

More specifically, while it has been common in the prior art to use water-soluble oils for working of non-ferrous metal parts such as aluminum or aluminum alloy parts, the metals generally tend to dissolve in the waste liquid after the non-ferrous metals have been worked, thus vastly increasing the cost for waste liquid treatment.

Moreover, using water-soluble oils results in decay or corrosion of parts unless the working fluid is at the optimum pH, and therefore strict and frequent management is essential during their use.

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