Water-soluble lubricant supply system

Abstract

A water-soluble lubricant supply system (1), which is an embodiment of a water-soluble lubricant supply system of the pressent invention, has: a water-soluble lubricant storage unit (10); piping (20) for circulating a water-soluble lubricant; a pump (30) for causing the water-soluble lubricant to flow from the water-soluble lubricant storage unit (10) to the piping (20); and a sterilizing light irradiation unit (40) for irradiating the water-soluble lubricant flowing and passing through the piping (20) with at least one of ultraviolet light and visible light having a wavelength of 380 to 420 nm. The sterilizing light irradiation unit (40) comprises at least one of: an ultraviolet light source composed of an ultraviolet light-emitting diode, an ultraviolet excimer lamp, or a combination thereof; and a visible light source capable of emitting visible light having a wavelength of 380 to 420 nm.

Description

Water-soluble lubricant supply system

[0001] The present invention relates to a water-soluble lubricant supply system.

[0002] Cutting fluids, also known as coolants, are used in metalworking equipment, such as cutting and grinding, to reduce friction between the tool and the workpiece, remove heat, and improve cutting efficiency and precision. When using water-soluble lubricants as cutting fluids, circulating them between the water-soluble lubricant supply device and the processing equipment can cause the heat in the processing equipment or heat caused by rising ambient temperatures to breed microorganisms such as bacteria, causing the water-soluble lubricant to spoil. For this reason, water-soluble lubricants are subjected to antiseptic treatment to prevent spoilage.

[0003] For example, Patent Document 1 discloses an ultraviolet sterilization device that sterilizes cutting oil by irradiating it with ultraviolet light, and discloses that the ultraviolet sterilization device comprises a storage section that stores a certain amount of cutting oil, a stirring section in which cutting oil that overflows from the storage section flows down while being stirred, and an irradiation means that is positioned opposite the stirring section and irradiates ultraviolet light.

[0004] Patent Document 2 discloses a method for ultraviolet sterilization of water-soluble metalworking oils, which discloses that when a coolant containing a water-soluble metalworking oil is circulated in metalworking, a shallow portion of the coolant is provided in the circulation path, and ultraviolet light is irradiated onto the coolant passing through the shallow portion.

[0005] Patent Document 3 discloses a method for improving the properties of water-soluble machining oils for machine tools, which method discloses the use of either a bactericidal metal ion agent, a tourmaline mixture, or a combination of these in equipment such as a tank or circulation path of a machine tool that uses water-soluble machining oils.

[0006] Patent Document 4 discloses a sterilization device for a water-soluble functional fluid, which includes at least a storage section for storing the water-soluble functional fluid, a light irradiation section for irradiating the water-soluble functional fluid with light, a metal working machine that performs metal processing while using the water-soluble functional fluid, and a circulation section for circulating the water-soluble functional fluid between the storage section and the metal working machine, and discloses that the water-soluble functional fluid that has been sterilized by the light irradiation section is supplied to the metal working machine by the circulation section.

[0007] Japanese Unexamined Patent Publication No. 2012-24880 Japanese Unexamined Patent Publication No. 04-264199 Unexamined Japanese Patent Application No. 08-165490 Unexamined Japanese Patent Application No. 2021-080321

[0008] However, the conventional techniques described above require a large-scale device for ultraviolet irradiation, making them difficult to apply to existing water-soluble lubricant supply systems. Also, there is room for improvement in terms of the sterilization effect.

[0009] An object of one aspect of the present invention is to provide a water-soluble lubricant supply system including at least one of an ultraviolet ray irradiation unit and a visible light irradiation unit that have a high sterilization effect.

[0010] As a result of intensive research into solving the above problems, the inventors discovered for the first time that by using a small light-emitting module such as an ultraviolet light-emitting diode (UV LED) or an excimer UV lamp as an ultraviolet light-emitting module, it becomes possible to place the ultraviolet light-emitting module within the pipeline of an existing water-soluble lubricant supply system, and as a result, a high sterilization effect can be obtained by irradiating ultraviolet light onto the water-soluble lubricant flowing through the pipeline, thereby completing the present invention.

[0011] That is, in order to solve the above-mentioned problems, a water-soluble lubricant supply system according to one embodiment of the present invention comprises a water-soluble lubricant storage section that stores a water-soluble lubricant, a pipeline that circulates the water-soluble lubricant stored in the water-soluble lubricant storage section, a pump that is provided in the pipeline and circulates the water-soluble lubricant from the water-soluble lubricant storage section to the pipeline, and at least one of an ultraviolet irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with ultraviolet light, and a visible light irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with visible light having a wavelength of 380 to 420 nm, wherein the ultraviolet irradiator has an ultraviolet light source that is either an ultraviolet light-emitting diode or an excimer light-emitting ultraviolet lamp, or a combination of these, and the visible light irradiator has a visible light source that irradiates visible light having a wavelength of 380 to 420 nm.

[0012] According to one aspect of the present invention, it is possible to provide a water-soluble lubricant supply system including at least one of an ultraviolet ray irradiator and a visible light irradiator, which have a high sterilization effect.

[0013] It is a diagram showing a schematic configuration of the water-soluble lubricant supply system according to the first embodiment of the present invention. It is a diagram showing a configuration of an ultraviolet ray irradiation unit provided in the water-soluble lubricant supply system according to the first embodiment of the present invention. It is a diagram showing a configuration of a second form of an ultraviolet ray irradiation unit that can be provided in the water-soluble lubricant supply system according to the first embodiment of the present invention.

[0014] Hereinafter, one embodiment of the present invention will be described in detail. In this specification, unless otherwise specified, the expression "A to B" representing a range of numerical values ​​means "A or more and B or less."

[0015] A water-soluble lubricant supply system according to one embodiment of the present invention includes a water-soluble lubricant storage section that stores a water-soluble lubricant, a pipeline that circulates the water-soluble lubricant stored in the water-soluble lubricant storage section, a pump that is provided in the pipeline and circulates the water-soluble lubricant from the water-soluble lubricant storage section to the pipeline, and at least one of an ultraviolet irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with ultraviolet light, and a visible light irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with visible light having a wavelength of 380 to 420 nm, wherein the ultraviolet irradiator has an ultraviolet light source that is either an ultraviolet light-emitting diode or an excimer light-emitting ultraviolet lamp, or a combination of these, and the visible light irradiator has a visible light source that irradiates visible light having a wavelength of 380 to 420 nm.

[0016] In a water-soluble lubricant supply system according to one embodiment of the present invention, the water-soluble lubricant is supplied from a water-soluble lubricant reservoir through a pipeline to a target, and after being used in the target for purposes such as lubrication or cooling, is returned from the target to the water-soluble lubricant reservoir through the pipeline. This series of systems that circulate the water-soluble lubricant is defined herein as a water-soluble lubricant supply system. In the water-soluble lubricant supply system according to one embodiment of the present invention, a pump circulates the water-soluble lubricant in the pipeline by applying energy to the water-soluble lubricant in the pipeline. The ultraviolet irradiation unit irradiates the water-soluble lubricant circulating in the pipeline in the water-soluble lubricant supply system according to one embodiment of the present invention with ultraviolet light. The visible light irradiation unit irradiates the water-soluble lubricant circulating in the pipeline in the water-soluble lubricant supply system according to one embodiment of the present invention with visible light having a wavelength of 380 to 420 nm.

[0017] According to one aspect of the water-soluble lubricant supply system of the present invention, at least one of an ultraviolet irradiation unit and a visible light irradiation unit is provided at at least one location along a series of pipelines through which the water-soluble lubricant flows, and at least one of ultraviolet light and visible light is irradiated onto the water-soluble lubricant flowing through the pipelines, thereby sterilizing the water-soluble lubricant.

[0018] Furthermore, a water-soluble lubricant supply system according to one embodiment of the present invention achieves a high sterilization effect on the water-soluble lubricant. The reason for this is explained below. The ultraviolet irradiation unit included in the water-soluble lubricant supply system according to one embodiment of the present invention irradiates the water-soluble lubricant flowing through the pipeline of the water-soluble lubricant supply system with ultraviolet light. Because the flow rate of the water-soluble lubricant is limited to a certain level within the pipeline, the water-soluble lubricant is less likely to become cloudy due to sludge compared to a water-soluble lubricant storage unit. As a result, the effectiveness of ultraviolet irradiation on the water-soluble lubricant is more easily achieved. As a result, a high sterilization effect on the water-soluble lubricant is achieved. Note that "sludge" contained in the water-soluble lubricant refers to insoluble matter mixed in the water-soluble lubricant and does not contribute to the lubricating performance of the water-soluble lubricant. Examples of such insoluble matter include cuttings such as metal chips generated by cutting a gold layer; external contaminants such as lubricating oils and greases used in machine tools; bacteria and other microorganisms that grow in the water-soluble lubricant; and insoluble matter resulting from the deterioration of the water-soluble lubricant's components due to the use of the water-soluble lubricant.

[0019] Furthermore, the ultraviolet irradiation unit of the water-soluble lubricant supply system according to one embodiment of the present invention includes an ultraviolet light source that is either an ultraviolet light-emitting diode (UV LED) or an excimer UV lamp, or a combination of these. Because these UV light sources are compact, there is no need to prepare a large-scale device for UV irradiation. Furthermore, these UV light sources can be placed inside the pipeline of the water-soluble lubricant supply system. This allows the UV light source to come into contact with the water-soluble lubricant inside the pipeline, thereby irradiating the water-soluble lubricant from within, making UV irradiation even more effective than irradiating UV light from above the reservoir. Furthermore, the synergistic effect of irradiating the water-soluble lubricant inside the pipeline with UV light provides an even more effective sterilization effect. The visible light irradiation unit of the water-soluble lubricant supply system according to one embodiment of the present invention also includes a visible light source that is either a visible light-emitting diode (visible LED) or an organic electroluminescent device (visible OLED) that emits visible light, or a combination of these. Because these visible light sources are compact, they provide a high sterilization effect on the water-soluble lubricant for the same reasons as the UV irradiation unit.

[0020] (Target to which water-soluble lubricant is supplied) The target to which the water-soluble lubricant is supplied by the water-soluble lubricant supply system according to one embodiment of the present invention (hereinafter referred to as the "target") is not particularly limited as long as it is desired to supply a water-soluble lubricant. Examples include machine tools that perform metal processing such as cutting and grinding; machining centers, lathes, milling machines, boring machines, drilling machines, grinding machines, and hobbing machines. Such targets may be incorporated into a part of the water-soluble lubricant supply system according to one embodiment of the present invention.

[0021] In addition to metal processing (removal processing) such as cutting and grinding, the water-soluble lubricant supply system according to one embodiment of the present invention may also be incorporated into a supply system for water-soluble lubricants used in plastic processing such as pressing, punching, bending, rolling, drawing, and drawing; and further, water-soluble lubricants such as non-flammable or flame-retardant hydraulic oils used not only in metal processing but also in places where fires are undesirable, such as steel mills and power plants.

[0022] (Water-soluble lubricant supplied) The water-soluble lubricant supplied by the water-soluble lubricant supply system according to one embodiment of the present invention will be described. Examples of such water-soluble lubricants include conventionally known water-soluble lubricants that are generally used as cutting fluids, such as the cutting fluids of Class A1, Class A2, and Class A3 specified in JIS K2241:2000. Among these, the cutting fluids of Class A1 are particularly preferred.

[0023] In addition to the cutting oils and grinding oils described above, water-soluble lubricants for all purposes are suitable for use in this water-soluble lubricant supply system, including water-soluble lubricants used in plastic processing, such as press oil, punching oil, bending oil, rolling oil, drawing oil, and drawing oil; and water-soluble lubricants such as non-flammable or flame-retardant hydraulic oils used not only in metal processing but also in places where fires are undesirable, such as steel mills and power plants.

[0024] (Microorganisms to be sterilized) In the water-soluble lubricant supply system according to one embodiment of the present invention, the microorganisms to be sterilized are those that can survive or grow in the water-soluble lubricant. Representative examples of such microorganisms include the following eubacteria and fungi, but the microorganisms to be sterilized are not limited to these: aerobic bacteria such as Pseudomonas. A representative species of Pseudomonas is P. aeruginosa. anaerobic bacteria such as enterobacteria such as Escherichia coli and Clostridium; sulfate-reducing bacteria such as Desulfovibrio denitrificans; and Fusarium molds (fusarium molds). In this specification, these microorganisms may be simply referred to as "bacteria."

[0025] Here, in this specification, "sterilization" of a water-soluble lubricant using at least one of ultraviolet light and visible light means removing bacteria from the water-soluble lubricant by irradiating it with at least one of ultraviolet light and visible light. "Sterilization" includes killing bacteria by applying ultraviolet light energy to the deoxyribonucleic acid (DNA) of bacteria; and generating reactive oxygen species (ROS) molecules such as singlet oxygen and hydrogen peroxide from within the bacteria by applying visible light energy to the Soret band, which strongly absorbs visible light and is contained in bacteria, fungi, and protozoa, and destroying cellular mechanisms with these reactive oxygen species. It also includes inactivating bacteria, preventing their proliferation and suppressing their growth. Inhibiting bacterial growth is also called "antibacterial."

[0026] (Water-soluble lubricant irradiated with at least one of ultraviolet light and visible light) After being used in a machine tool, the used water-soluble lubricant is returned to a water-soluble lubricant reservoir to be reused and supplied to the machine tool again. The water-soluble lubricant reservoir to which the used water-soluble lubricant is returned is called the first reservoir. The first reservoir stores water-soluble lubricant including the used water-soluble lubricant. The water-soluble lubricant stored in the reservoir of the first reservoir is called dirty liquid.

[0027] Dirty fluid contains foreign matter such as sludge, so it is passed through a filter to remove the foreign matter before being supplied to the machine tool again. Water-soluble lubricant from which the foreign matter has been removed to the extent that it can be supplied to the machine tool is called clean fluid.

[0028] In a water-soluble lubricant supply system according to one embodiment of the present invention, from the viewpoint of the ultraviolet irradiation effect, it is preferable to irradiate the dirty liquid with at least one of ultraviolet light and visible light, but it is also possible to irradiate the clean liquid with at least one of ultraviolet light and visible light, or to irradiate both the dirty liquid and the clean liquid with at least one of ultraviolet light and visible light.

[0029] In a water-soluble lubricant supply system according to one aspect of the present invention, when the contaminated fluid is irradiated with at least one of ultraviolet light and visible light, it is preferable to remove foreign matter using two types of filters with different filtering performance in the process of generating clean fluid from the contaminated fluid. In this specification, these two types of filters are referred to as a first filter and a second filter. The first filter has lower filtering performance than the second filter. The first filter and the second filter will be described in detail later.

[0030] In this specification, the dirty liquid before passing through the first filter is particularly referred to as "primary dirty liquid," and the dirty liquid after passing through the first filter is particularly referred to as "secondary dirty liquid."

[0031] The secondary contaminated liquid is more transparent than the primary contaminated liquid because the large particles contained in the primary contaminated liquid have been removed by the first filter. Therefore, the secondary contaminated liquid is more transparent to ultraviolet and visible light than the primary contaminated liquid. However, the secondary contaminated liquid does not have enough foreign matter removed to be considered clean, and small particles such as metal powders, such as iron oxide, are dispersed in the liquid. Therefore, the secondary contaminated liquid is classified as a dirty liquid.

[0032] Foreign matter such as small particle size metal powders such as iron oxide has the property of scattering ultraviolet and visible light, so the secondary contaminated liquid has the property of scattering ultraviolet and visible light more easily than the clean liquid.

[0033] By passing the secondary contaminated liquid through a second filter, foreign matter such as small particle diameter metal powders including iron oxide that were not removed by the first filter can be removed, and clean liquid can be obtained. The clean liquid may be generated by passing the primary contaminated liquid directly through the second filter.

[0034] The primary contaminated fluid, secondary contaminated fluid, and clean fluid can also be distinguished by their appearance and color at room temperature (25°C). For example, if the water-soluble lubricant is a cutting fluid of Class A1 or any of the subparagraphs specified in JIS K2241:2000, the primary contaminated fluid has a brownish-red appearance color containing visible foreign matter and floating matter. The secondary contaminated fluid has a brownish-red to brown appearance color containing no visible foreign matter or floating matter. The clean fluid has a brownish-white appearance color containing no visible foreign matter or floating matter. Here, "brownish-red" refers to a dark brown with a slight blackish tinge. The secondary contaminated fluid can be distinguished from the primary contaminated fluid by its absence of visible foreign matter and floating matter and its lighter brown appearance color than the primary contaminated fluid. The secondary contaminated fluid can also be distinguished from the clean fluid by its darker brown appearance color than the clean fluid.

[0035] (Water-soluble lubricant storage section) The water-soluble lubricant storage section is not particularly limited in volume, shape, etc., as long as it can store the water-soluble lubricant therein. Conventionally known water tanks, tanks, etc. can be used as the water-soluble lubricant storage section.

[0036] The water-soluble lubricant reservoir preferably includes at least a first reservoir for storing dirty fluid and a second reservoir for storing clean fluid. By providing two types of reservoirs, it is possible to separately store used dirty fluid returned from the machine tool and clean fluid to be supplied to the machine tool. Furthermore, by temporarily storing the dirty fluid and clean fluid in the reservoirs, the flow rates of the pump that supplies the water-soluble lubricant from the first reservoir to the second reservoir and the pump that supplies clean fluid from the second reservoir to the machine tool are stabilized, enabling continuous supply.

[0037] (Pipeline) The pipeline is not particularly limited in terms of material, diameter, shape, etc., as long as it is a hollow pipe through which the water-soluble lubricant can flow. The length of the pipeline can be selected appropriately depending on the distance between the water-soluble lubricant reservoir and the machine tool, the distance between the first reservoir and the second reservoir, etc.

[0038] (Pump) The type of pump is not particularly limited. Regarding the performance of the pump (e.g., discharge rate, head, etc.), a pump having an appropriate output can be selected appropriately depending on the scale of the water-soluble lubricant supply system according to one aspect of the present invention.

[0039] In the water-soluble lubricant supply system according to one aspect of the present invention, it is preferable to use two types of filters with different filtering performance in the process of producing clean liquid from dirty liquid. In this specification, these two types of filters are referred to as a first filter and a second filter.

[0040] The first filter has lower filtering performance than the second filter. "Lower filtering performance than the second filter" means that the size of particles that the first filter can remove by filtration is larger than that of the second filter. The first filter has filtering performance that can remove large particles contained in the primary contaminant fluid, but is unable to remove foreign matter such as metal powders of small particle size, such as iron oxide, allowing them to pass through.

[0041] For example, the particle size of the foreign matter passing through the first filter is at least twice as large as the particle size of the foreign matter passing through the second filter. When a filter with higher filtering performance is used as the second filter, the particle size of the foreign matter that can be passed through the first filter can be 3 times or more, 5 times or more, 10 times or more, 15 times or more, or 20 times or more larger than the particle size of the foreign matter that can be passed through the second filter.

[0042] The first filter is used to roughly remove foreign matter from the primary contaminant liquid. For example, particles with a diameter of 100 μm or more can be removed from the primary contaminant liquid by passing the liquid through the first filter.

[0043] Therefore, it is preferable to use a filter capable of removing particles with a diameter of 100 μm or more as the first filter, so that foreign matter such as small-particle metal powders including iron oxide contained in the primary contaminant fluid and active ingredients such as small-particle water-soluble lubricant micelles can pass through the first filter without being removed.

[0044] By passing the primary contaminated liquid through the first filter, foreign matter can be roughly removed from the primary contaminated liquid to generate the secondary contaminated liquid. Therefore, the first filter is a filter for generating the secondary contaminated liquid from the primary contaminated liquid.

[0045] The first filter can be, for example, a conventionally known filter used for the purpose of rough filtration. Examples of such filters include depth filters, pleated filters, bag filters, resin filters, wire mesh strainers, and suction strainers. For example, any conventionally known filter installed in the suction-side pipe of a pump for the purpose of protecting the pump from foreign matter in the liquid can be suitably used as the first filter. Furthermore, for example, in the case of a wire mesh filter, a wire mesh filter with 80 mesh (opening 360 μm) to 200 mesh (opening 90 μm) can be suitably used as the first filter.

[0046] The second filter is a filter for producing clean liquid from the secondary contaminated liquid. By passing the secondary contaminated liquid through the second filter, small foreign matter (e.g., particles with a diameter of 50 μm or more) that could not be removed by the first filter can be removed from the secondary contaminated liquid.

[0047] Therefore, it is preferable to use a filter capable of removing particles having a diameter of 50 μm or more as the second filter. From the viewpoint of producing a cleaner clean liquid by removing foreign matter such as metal powders of small diameters, such as iron oxide, that were not removed by the first filter while maintaining the active ingredients, such as micelles, of the water-soluble lubricant, it is more preferable that the second filter be capable of removing particles having a diameter of 30 μm or more, more preferably be capable of removing particles having a diameter of 25 μm or more, more preferably be capable of removing particles having a diameter of 20 μm or more, more preferably be capable of removing particles having a diameter of 10 μm or more, and even more preferably be capable of removing particles having a diameter of 5 μm or more.

[0048] The second filter may be, for example, a conventionally known filter used to produce clean liquid from dirty liquid, such as a cyclone filter, a porous filter, a resin filter, a screen filter, a nonwoven fabric filter, a wound filter, or a membrane filter.

[0049] In the water-soluble lubricant supply system according to one aspect of the present invention, at least one of ultraviolet light and visible light may be irradiated only on the clean liquid. In this case, since there is no need to generate a secondary contaminated liquid, the first filter may not be used and the primary contaminated liquid may be passed directly through the second filter to generate the clean liquid.

[0050] In a water-soluble lubricant supply system according to one aspect of the present invention, a third filter may be provided in the line supplying the clean liquid from the second reservoir to the machine tool. By providing the third filter in the suction-side line upstream of the pump, if the clean liquid contains foreign matter that reduces the flow of the water-soluble lubricant through the supply path or that reduces quality due to contamination during machining, the foreign matter can be removed to maintain the supply path and quality. The third filter may be the same filter as the first filter.

[0051] (Ultraviolet Irradiation Unit and Ultraviolet Light Source) In a water-soluble lubricant supply system according to one aspect of the present invention, the ultraviolet irradiation unit includes an ultraviolet light source that is either an ultraviolet LED or an excimer light-emitting ultraviolet lamp, or a combination of these. The ultraviolet light source is a part of the ultraviolet irradiation unit that emits ultraviolet light. In the water-soluble lubricant supply system according to one aspect of the present invention, the ultraviolet LED and excimer light-emitting ultraviolet lamp that can be used as the ultraviolet light source can be any ultraviolet LED or excimer light-emitting ultraviolet lamp that is configured to emit ultraviolet light (wavelength of 400 nm or less).

[0052] In the water-soluble lubricant supply system according to one embodiment of the present invention, the ultraviolet irradiation unit may include only one of an ultraviolet LED or an excimer light-emitting ultraviolet lamp as the ultraviolet light source, or may include a combination of an ultraviolet LED and an excimer light-emitting ultraviolet lamp. The type of ultraviolet light source can be selected appropriately. For example, when the ultraviolet irradiation environment or the piping (conduit) is a sealed and closed environment, an ultraviolet LED is selected as the ultraviolet light source; when the ultraviolet irradiation environment or the piping (conduit) is open or the piping (conduit) is transparent, an excimer light-emitting ultraviolet lamp is selected as the ultraviolet light source; and when a sealed and closed environment and an open environment are mixed, an ultraviolet LED and an excimer light-emitting ultraviolet lamp are used together as the ultraviolet light source.

[0053] Since ultraviolet rays are harmful to living organisms, including humans, when using ultraviolet LEDs, it is preferable to irradiate the ultraviolet rays in an environment where the ultraviolet rays do not leak outside the tube. On the other hand, excimer emission ultraviolet lamps can emit ultraviolet rays with a specific wavelength of 222 nm, which is not harmful to the human body, so they can be used in environments where ultraviolet rays leak outside the tube, such as open environments.

[0054] From the viewpoint of sterilization effect against microorganisms, the ultraviolet light source is preferably configured to emit ultraviolet light with a wavelength of 315 nm or less, and more preferably configured to emit ultraviolet light with a wavelength of 300 nm or less. Ultraviolet light in the wavelength range of 200 to 300 nm is particularly called "deep ultraviolet light" and is known to have a particularly high sterilization effect against microorganisms. Furthermore, among the deep ultraviolet wavelength ranges, ultraviolet light in the wavelength range of 220 to 285 nm is more preferred because it has a high sterilization effect against microorganisms. Furthermore, ultraviolet light with a wavelength of 222 nm is even more preferred because it has little effect on the human body and has a high sterilization effect against microorganisms.

[0055] Therefore, in a water-soluble lubricant supply system according to one embodiment of the present invention, the ultraviolet light source is preferably a light source that emits deep ultraviolet light, more preferably a light source that emits deep ultraviolet light in the wavelength range of 220 to 285 nm, and even more preferably a light source that emits deep ultraviolet light with a wavelength of 222 nm.

[0056] The ultraviolet light source is preferably an ultraviolet light-emitting LED that emits deep ultraviolet light, because it is small and therefore easily applicable to existing water-soluble lubricant supply systems, has a smaller environmental impact than mercury-based ultraviolet lamps, and is smaller and has a longer lifespan.

[0057] (UV irradiation amount) The greater the UV irradiation amount, the greater the sterilization effect tends to be. UV irradiation amount (mJ / cm ２ ) is calculated from the following formula: UV irradiation dose (mJ / cm ２ ) = illuminance (mW / cm ２ ) x irradiation time (seconds).

[0058] In the water-soluble lubricant supply system according to one aspect of the present invention, the ultraviolet irradiation amount (mJ / cm) at which a sufficient sterilization effect can be obtained is ２ In order to irradiate the water-soluble lubricant in the pipeline with ultraviolet rays of 1000 W or more, the distance from the ultraviolet light source to the water-soluble lubricant to be irradiated (for example, the position where the ultraviolet light source is installed, the diameter of the pipeline, etc.), the flow rate of the water-soluble lubricant in the pipeline, the irradiation time of the ultraviolet rays, the output of the ultraviolet light source, the flow state of the water-soluble lubricant in the ultraviolet irradiation area (laminar flow, turbulent flow), etc. may be adjusted.

[0059] The amount of ultraviolet light required for sterilization varies depending on the type of microorganism, but the amount of ultraviolet light required is at least 3 mJ / cm ２ If there is such a substance, it is believed that a sufficient sterilization effect can be obtained against the microorganisms listed above as examples of microorganisms to be sterilized.

[0060] (Visible Light Irradiation Unit and Visible Light Source) The visible light irradiation unit includes a visible light source. The visible light source is a portion of the visible light irradiation unit that emits visible light with a wavelength of 380 to 420 nm. Visible light with a wavelength of 380 to 420 nm has a disinfecting effect. From the viewpoint of superior disinfection effect, visible light with a wavelength around 405 nm is particularly preferable. In the following description, a visible light source that emits visible light with a wavelength of 380 to 420 nm will be referred to as a "380-420 nm visible light source." Unlike the action of ultraviolet light on the DNA inside bacteria, 380-420 nm visible light acts on the Soret band, which strongly absorbs visible light, contained in bacteria, fungi, and protozoa, thereby generating reactive oxygen species (ROS) molecules such as singlet oxygen and hydrogen peroxide from inside the bacteria, and these reactive oxygen species have an action mechanism that destroys cellular mechanisms. In one embodiment of the water-soluble lubricant supply system of the present invention, the 380 to 420 nm visible light irradiation unit can be a device equipped with a visible light source capable of irradiating visible light with a wavelength of 380 to 420 nm, which is either a visible light LED or a visible light OLED, or a combination of these.

[0061] The visible light irradiation unit emits light with a wavelength of 380 to 420 nm in the visible light range. Unlike ultraviolet light, which acts on the DNA of cells, including those in the human body, the visible light irradiation unit has a mechanism that acts only on bacteria, so it can be used in environments where the light emitted from the visible light irradiation unit leaks. In addition, because it has lower energy than ultraviolet light, it has the advantage of being able to reduce the impact on chemical base materials (e.g., additives such as surfactants) contained in water-soluble lubricants.

[0062] (Visible Light Irradiation Amount) As with ultraviolet light, the greater the irradiation amount of visible light with a wavelength of 380 to 420 nm, the greater the sterilization effect tends to be. In the water-soluble lubricant supply system according to one aspect of the present invention, the light irradiation amount (mJ / cm) at which a sufficient sterilization effect can be obtained is ２ The distance from the visible light source to the water-soluble lubricant to be irradiated (for example, the position where the visible light source is installed, the diameter of the pipeline, etc.), the flow rate of the water-soluble lubricant in the pipeline, the irradiation time of the visible light, the output of the visible light source, the flow state of the water-soluble lubricant in the visible light irradiation area (laminar flow, turbulent flow), etc. may be adjusted so that visible light of a wavelength of 380 to 420 nm can be irradiated to the water-soluble lubricant in the pipeline.

[0063] The amount of visible light irradiation required for sterilization varies depending on the type of microorganism, but the amount of visible light irradiation is at least 3 mJ / cm ２ If there is such a substance, it is believed that a sufficient sterilization effect can be obtained against the microorganisms listed above as examples of microorganisms to be sterilized.

[0064] [Embodiment 1] Hereinafter, one embodiment of the present invention will be described in detail with reference to Figures 1 and 2. Figure 1 is a diagram schematically showing the configuration of a water-soluble lubricant supply system 1 according to this embodiment. Arrows in Figure 1 indicate the flow direction of the water-soluble lubricant in a pipeline 20. Figure 2 is a diagram showing the configuration of an ultraviolet irradiation unit 40 provided in the water-soluble lubricant supply system 1. For ease of explanation, Figure 2 shows the pipeline 20 as a cross-sectional view taken along the pipeline axis. Figure 2 also shows the state in which the water-soluble lubricant flows through the pipeline 20.

[0065] 1, the water-soluble lubricant supply system 1 includes, as water-soluble lubricant storage sections, a dirty tank (first storage section) 101 for storing dirty liquid and a clean tank (second storage section) 102 for storing clean liquid. The system also includes, as pipelines, a first pipeline 201, a second pipeline 202, a third pipeline 203, and a fourth pipeline 204.

[0066] The water-soluble lubricant supply system 1 regenerates dirty liquid in the dirty tank 101 into clean liquid by passing it through the second pipeline 202 and stores it in the clean tank 102. The clean liquid in the clean tank 102 is supplied to the machine tool 50 through the third pipeline 203. The used water-soluble lubricant (contaminated liquid) used in the machine tool 50 is returned to the dirty tank 101 through the fourth pipeline 204 and reused. In the first pipeline 201, the second pipeline 202, and the third pipeline 203, respectively, ultraviolet irradiation units 401, 402, 404, and 403 irradiate the water-soluble lubricant with ultraviolet light to disinfect the water-soluble lubricant. In the following description, the two tanks 101 and 102 may be referred to simply as tank 10 without distinction. Furthermore, the four pipelines 201 to 204 may be referred to simply as pipeline 20 without distinction. Furthermore, the four ultraviolet irradiation units 401 to 404 may be simply referred to as ultraviolet irradiation unit 40 without being distinguished from one another.

[0067] The configuration and function of each part of the water-soluble lubricant supply system 1 will be described in detail below for each pipeline.

[0068] (First Pipeline 201) The first pipeline 201 is a pipeline for agitating the dirty fluid in the dirty tank 101. The first pipeline 201 is configured to agitate the dirty fluid in the dirty tank 101 by sucking the dirty fluid in the dirty tank 101 from one end and discharging it into the dirty tank 101 from the other end. Specifically, the first pipeline 201 is equipped with four nozzles at the end of the discharge-side pipeline 2012. This can increase the agitation efficiency of the primary dirty fluid in the dirty tank 101. The number of nozzles is not limited to four and can be changed as appropriate.

[0069] In the first pipeline 201, a first filter 601, a pump 301, and an ultraviolet irradiation unit 401 are provided in this order along the flow of the contaminated fluid in the first pipeline 201 from upstream to downstream. The first filter 601 is a filter for generating secondary contaminated fluid from the primary contaminated fluid. In the first pipeline 201, the primary contaminated fluid passes through the first filter 601 to generate the secondary contaminated fluid.

[0070] The ultraviolet light source 411 ( FIG. 2 ) is located downstream of the first filter 601 in the ultraviolet light irradiation unit 401, and the ultraviolet light irradiation unit 401 irradiates the secondary contaminated fluid with ultraviolet light. Because the secondary contaminated fluid is more transparent than the primary contaminated fluid, ultraviolet light passes through it more easily. Furthermore, the ultraviolet light is easily scattered by foreign matter, such as small-particle-sized metal powders of iron oxide, making the ultraviolet light irradiation more effective than irradiating the clean fluid. As a result, a higher disinfection effect can be achieved. Furthermore, if the water-soluble lubricant is, for example, a cutting fluid of Class A1 or any of the items specified in JIS K2241:2000, the ultraviolet light is also scattered by the micelles that make up the water-soluble lubricant, thereby further enhancing the effectiveness of the ultraviolet light irradiation.

[0071] 2, the ultraviolet light source 411 of the ultraviolet light irradiation unit 401 is provided inside the first pipeline 201, so that the ultraviolet light source 411 irradiates the secondary contaminated fluid with ultraviolet light from inside the secondary contaminated fluid while in contact with the secondary contaminated fluid in the first pipeline 201. As a result, the effect of ultraviolet light irradiation is more easily exerted. In other words, by providing the ultraviolet light irradiation unit 401 in the first pipeline 201 and irradiating ultraviolet light, the synergistic effect obtained by irradiating the water-soluble lubricant in the pipeline with ultraviolet light as described above is further enhanced by irradiating the secondary contaminated fluid with ultraviolet light from both inside and outside, resulting in an even greater sterilization effect.

[0072] The primary contaminated liquid in the dirty tank has low transparency, making it difficult to irradiate it with ultraviolet light, and conventional techniques have made it difficult to sterilize the primary contaminated liquid in the dirty tank with ultraviolet light. In contrast, the water-soluble lubricant supply system 1 converts the primary contaminated liquid into secondary contaminated liquid by passing it through the first pipeline 201, and irradiates the secondary contaminated liquid with ultraviolet light in the first pipeline 201, making it possible to sterilize the contaminated liquid with ultraviolet light. Therefore, the water-soluble lubricant supply system 1 continuously circulates the primary contaminated liquid in the dirty tank 101 through the first pipeline 201, thereby enabling the primary contaminated liquid in the dirty tank 101 to be sterilized with ultraviolet light and preventing the primary contaminated liquid in the dirty tank 101 from spoiling.

[0073] Furthermore, an additional effect of providing the first pipe 201 is that foreign matter in the primary contaminated fluid can be collected with high efficiency. Specifically, by stirring the primary contaminated fluid in the dirty tank 101 using the first pipe 201, an optimal flow of the primary contaminated fluid can be formed in the dirty tank 101, making it difficult for foreign matter to accumulate at the bottom of the dirty tank 101. As a result, foreign matter in the primary contaminated fluid can be collected with high efficiency by the second filter 604 provided in the second pipe 202.

[0074] The diameter of the first conduit 201 is preferably 0.3 cm or more in terms of the flow rate, flow rate, and liquid flow state of the water-soluble lubricant, and is preferably 15 cm or less in terms of ultraviolet irradiation efficiency.

[0075] (Second Pipeline 202) The second pipeline 202 is a pipeline for circulating the water-soluble lubricant from the dirty tank 101 to the clean tank 102. The second pipeline 202 is configured to suck in the dirty liquid in the dirty tank 101 from one end and discharge the clean liquid into the clean tank 102 from the other end.

[0076] The second pipeline 202 is provided with a first filter 602, a pump 302, an ultraviolet irradiation unit 404, a second filter 604, and an ultraviolet irradiation unit 402, in this order, along the flow of the water-soluble lubricant in the second pipeline 202. The first filter 602 is a filter for generating a secondary contaminated fluid from the primary contaminated fluid. The second filter 604 is a filter for generating a clean fluid from the contaminated fluid. In the second pipeline 202, the primary contaminated fluid passes through the first filter 602 to generate a secondary contaminated fluid, and then passes through the second filter 604 to generate a clean fluid. The generated clean fluid is supplied to the clean tank 102 through the second pipeline 202.

[0077] The ultraviolet irradiation unit 404 has an ultraviolet light source 414 (FIG. 2) provided between the first filter 602 and the second filter 604, and irradiates the secondary contaminated fluid with ultraviolet light. The ultraviolet irradiation unit 402 also has an ultraviolet light source 412 (FIG. 2) provided downstream of the position where the second filter 604 is provided, and irradiates the clean fluid with ultraviolet light.

[0078] As shown in FIG. 2, the ultraviolet irradiation unit 404 and the ultraviolet irradiation unit 402 have ultraviolet light sources 414 and 412 respectively provided inside the second pipe 202 .

[0079] By providing an ultraviolet irradiation unit 404 in the second pipeline 202 and irradiating it with ultraviolet light, it is possible to supply sterilized clean liquid to the clean tank 102. This makes it possible to prevent the clean liquid in the clean tank 102 from spoiling. Furthermore, with the above-described configuration of the second pipeline 202, the synergistic effect obtained by irradiating the water-soluble lubricant in the pipeline with ultraviolet light is further enhanced by irradiating the secondary contaminated liquid with ultraviolet light from the inside, thereby achieving an even greater sterilization effect. Furthermore, by providing an ultraviolet irradiation unit 402 in the second pipeline 202 and irradiating the clean liquid with ultraviolet light, an even greater sterilization effect can be achieved.

[0080] The diameter of the second conduit 202 is preferably 0.3 cm or more in terms of the flow rate, flow rate, and liquid flow state of the water-soluble lubricant, and is preferably 15 cm or less in terms of ultraviolet irradiation efficiency.

[0081] (Third Pipeline 203) The third pipeline 203 is a pipeline for supplying the clean liquid from the clean tank 102 to the machine tool 50. The third pipeline 203 is configured to suck the clean liquid in the clean tank 102 from one end and discharge the clean liquid to the machine tool 50 from the other end.

[0082] In the third pipeline 203, a third filter 603, a pump 303, and an ultraviolet irradiation unit 403 are provided in this order along the flow of the cleaning liquid in the third pipeline 203 from upstream to downstream.

[0083] The third filter 603 is provided in the suction-side pipe 2031 upstream of the pump 303. The third filter 603 is provided to maintain the supply path and quality by removing foreign matter that may reduce the flow of the water-soluble lubricant through the supply path or may be mixed in during processing and reduce quality when the clean liquid contains such foreign matter.

[0084] The ultraviolet irradiating unit 403 has an ultraviolet light source 413 (FIG. 2) provided in the discharge-side pipe 2032 downstream of the pump 303, and irradiates the cleaning liquid with ultraviolet light.

[0085] As shown in FIG. 2, the ultraviolet irradiation unit 403 has an ultraviolet light source 413 provided inside the third pipe 203 .

[0086] By providing an ultraviolet irradiation section 403 in the third pipeline 203 and irradiating ultraviolet light therewith, it is believed that a synergistic effect can be obtained by irradiating the water-soluble lubricant in the pipeline with ultraviolet light as described above, thereby achieving a high sterilization effect on the clean liquid supplied to the machine tool 50.

[0087] The third conduit 203 preferably has an inner diameter of 0.3 cm or more in terms of the flow rate, flow rate, and liquid flow state of the water-soluble lubricant, and preferably has an inner diameter of 15 cm or less in terms of ultraviolet irradiation efficiency.

[0088] (Fourth Pipe 204) The fourth pipe 204 is a pipe for returning the used water-soluble lubricant discharged from the machine tool 50 to the dirty tank 101.

[0089] The diameter of the fourth conduit 204 is preferably 0.3 cm or more in terms of the flow rate, flow rate, and liquid flow state of the water-soluble lubricant. Also, from the viewpoint of miniaturization and space saving, the diameter is preferably 15 cm or less.

[0090] (Second Form of Ultraviolet Irradiation Unit) The ultraviolet irradiator that can be provided in the water-soluble lubricant supply system 1 is not limited to the form shown in Fig. 2. A second form of the ultraviolet irradiator that can be provided in the water-soluble lubricant supply system 1 will be described with reference to Fig. 3. Fig. 3 is a diagram showing the configuration of an ultraviolet irradiator 140, which is the second form of the ultraviolet irradiator that can be provided in the water-soluble lubricant supply system 1. For ease of explanation, Fig. 3 shows the pipeline 20 in a cross-sectional view along the pipeline axis direction. Fig. 3 also shows a state in which the water-soluble lubricant is flowing through the pipeline 20.

[0091] As shown in FIG. 3 , the ultraviolet irradiation unit 140 is an ultraviolet irradiation module including an ultraviolet light source 141, a pipeline 142, and a housing 143. The housing 143 is provided to surround the pipeline 142. The ultraviolet light source 141 is provided inside the pipeline 142. The ultraviolet light source 141 irradiates ultraviolet light onto the water-soluble lubricant flowing through the pipeline 142. When the ultraviolet irradiation unit 140 is applied to the water-soluble lubricant supply system 1, both ends of the pipeline 142 of the ultraviolet irradiation unit 140 are respectively joined to the pipeline 20 of the water-soluble lubricant supply system 1, so that the pipeline 142 forms part of the pipeline 20 of the water-soluble lubricant supply system 1. Since the ultraviolet light source 141 is provided inside the pipeline 142, it can also be said that the ultraviolet light source 141 is provided inside the pipeline 20.

[0092] A modified example of the water-soluble lubricant supply system 1 will be described below.

[0093] <Modification 1> In the above description, an example has been given of a configuration in which the water-soluble lubricant supply system 1 includes all of the ultraviolet ray irradiation units 401, 402, 403, and 404, but this does not limit the present embodiment. The water-soluble lubricant supply system 1 may also be configured to include at least one of the ultraviolet ray irradiation units 401, 402, 403, and 404.

[0094] For example, the water-soluble lubricant supply system 1 may be configured to include an ultraviolet irradiation unit 401 but not include ultraviolet irradiation units 402, 403, and 404; an ultraviolet irradiation unit 402 but not include ultraviolet irradiation units 401, 403, and 404; an ultraviolet irradiation unit 403 but not include ultraviolet irradiation units 401, 402, and 404; an ultraviolet irradiation unit 404 but not include ultraviolet irradiation units 401, 402, and 403; an ultraviolet irradiation unit 401 and 404 but not include ultraviolet irradiation units 402 and 403; or an ultraviolet irradiation unit 401 and 403 but not include ultraviolet irradiation units 404 and 402.

[0095] Since the ultraviolet irradiation unit 40 is easy to install, a higher sterilization effect is obtained by irradiating the secondary dirty liquid with ultraviolet light, and it does not involve the second pipeline 202 and the third pipeline 203, which are the main piping routes for supplying the water-soluble lubricant to the machine tool 50, it is most preferable that the water-soluble lubricant supply system 1 be configured to include at least an ultraviolet irradiation unit 401.

[0096] <Modification 2> In the above description, an example has been given of a configuration in which the water-soluble lubricant supply system 1 has the first filters 601 and 602 installed in the suction-side pipes 2011 and 2021 upstream of the pumps 301 and 302, respectively, but this does not limit the present embodiment. The water-soluble lubricant supply system 1 may also be configured such that the first filter 601 is installed in the discharge-side pipe 2012 of the first pipe 201, at a position between the pump 301 and the ultraviolet light irradiation unit 401. Similarly, the first filter 602 may also be installed in the discharge-side pipe 2022 of the second pipe 202, at a position between the pump 302 and the ultraviolet light irradiation unit 404.

[0097] In order to protect the pumps from foreign matter in the water-soluble lubricant, it is preferable to install first filters 601 and 602 in the suction-side pipes 2011 and 2021 upstream of the pumps 301 and 302, respectively.

[0098] <Modification 3> In the above description, an example has been given of a configuration in which the water-soluble lubricant supply system 1 includes all of the first filters 601 and 602, but this does not limit the present embodiment. The first filters 601 and 602 can be omitted if no corresponding ultraviolet irradiation units are provided downstream thereof.

[0099] <Modification 4> In the above description, an example has been given of a configuration in which the ultraviolet light source 41 of the ultraviolet irradiation unit 40 is provided inside the pipeline 20, but this does not limit the present embodiment. As long as the configuration is such that ultraviolet light can be irradiated onto the water-soluble lubricant inside the pipeline 20, the location where the ultraviolet light source 41 is provided is not limited to inside the pipeline 20. For example, a configuration may be adopted in which an ultraviolet light transmitting portion is formed in a part of the wall of the pipeline 20 using a member that transmits ultraviolet light, and ultraviolet light is irradiated from outside the pipeline 20 via the ultraviolet light transmitting portion.

[0100] 2 has been described using an example in which the ultraviolet irradiation unit 40 includes one ultraviolet light source 41, but this does not limit the present embodiment. The ultraviolet irradiation unit 40 may include multiple ultraviolet light sources 41, and the number of such light sources may be set as appropriate. Furthermore, the shape of the conduit 20 is not limited to the straight conduit shown in FIG. 2 , and various shapes such as an L-shape or a T-shape may be adopted. Furthermore, the location of the ultraviolet light source 41 of the ultraviolet irradiation unit 40 is not limited to the top or bottom of the piping. For example, if the conduit 20 is L-shaped, the location may be selected appropriately, such as at a right angle of the L-shape, depending on the degree of sterilization effect.

[0101] <Modification 5> In the above description, an example has been given of a configuration in which ultraviolet light is irradiated onto the water-soluble lubricant circulating through the pipeline 20, but this does not limit the present embodiment. The water-soluble lubricant supply system 1 may be configured as follows: (i) to further include an ultraviolet light irradiation unit above and / or inside the dirty tank 101 so as to directly irradiate ultraviolet light onto the dirty liquid stored in the dirty tank 101; (ii) to further include an ultraviolet light irradiation unit above and / or inside the clean tank 102 so as to directly irradiate ultraviolet light onto the clean liquid stored in the clean tank 102; or a combination of the above (i) and (ii).

[0102] The ultraviolet irradiation unit for directly irradiating ultraviolet rays onto the dirty liquid or clean liquid stored in the dirty tank 101 or clean tank 102 can be equipped with an ultraviolet light source the same as the ultraviolet light source 41 of the ultraviolet irradiation unit 40.

[0103] <Variation 6> In the above description, an example has been given of a configuration in which the water-soluble lubricant supply system 1 includes an ultraviolet light irradiation unit 40, but this does not limit the present embodiment. The water-soluble lubricant supply system 1 may include a visible light irradiation unit instead of the ultraviolet light irradiation unit 40, or may include both the ultraviolet light irradiation unit 40 and a visible light irradiation unit. The above-described variations 1 to 5 are also applicable to the lubricant supply system 1 including a visible light irradiation unit. In the lubricant supply system 1 including a visible light irradiation unit and its variations 1 to 5, some or all of the members 40, 401, 402, 403, and 404 shown in FIGS. 1 and 2 and the member 140 shown in FIG. 3 are visible light irradiation units, and some or all of the members 41, 411, 412, 413, and 414 shown in FIGS. 1 and 2 and the member 141 shown in FIG. 3 are visible light sources.

[0104] [Reference Form] As a reference form, an example of a water-soluble lubricant supply system is provided in which the water-soluble lubricant supply system does not include an ultraviolet irradiation unit for irradiating ultraviolet rays onto the water-soluble lubricant circulating through the pipeline, but includes an ultraviolet irradiation unit for irradiating ultraviolet rays directly onto the dirty liquid or clean liquid stored in the dirty tank or clean tank.

[0105] The water-soluble lubricant supply system according to the reference embodiment may be configured as follows: (i) to include an ultraviolet irradiation unit above and / or inside the dirty tank so as to irradiate ultraviolet rays directly onto the dirty liquid stored in the dirty tank; (ii) to include an ultraviolet irradiation unit above and / or inside the clean tank so as to irradiate ultraviolet rays directly onto the clean liquid stored in the clean tank; or a combination of (i) and (ii).

[0106] The configuration of the ultraviolet irradiation unit for directly irradiating ultraviolet rays onto the dirty liquid or clean liquid stored in the dirty tank or clean tank is not particularly limited, but for example, the configuration described in variant example 5 of the water-soluble lubricant supply system 1 can be adopted.

[0107] In addition, the water-soluble lubricant supply system according to the reference embodiment may be configured to include a visible light irradiation unit that irradiates visible light with a wavelength of 380 to 420 nm instead of an ultraviolet irradiation unit, thereby irradiating visible light with a wavelength of 380 to 420 nm directly onto the dirty liquid or clean liquid stored in the dirty tank or clean tank, or may be configured to include both the ultraviolet irradiation unit and the visible light irradiation unit.

[0108] <Method for Disinfecting a Water-Soluble Lubricant> A method for disinfecting a water-soluble lubricant is also included in the scope of the present invention. That is, a method for disinfecting a water-soluble lubricant according to one embodiment of the present disclosure is a method for disinfecting a water-soluble lubricant, comprising the step of irradiating the water-soluble lubricant with visible light having a wavelength of 380 to 420 nm. The "visible light having a wavelength of 380 to 420 nm" is as described above.

[0109] The method for sterilizing a water-soluble lubricant according to one embodiment of the present disclosure can be applied to all devices and systems that handle water-soluble lubricants, and can sterilize the water-soluble lubricants that these devices and systems handle.

[0110] As an example, the method for sterilizing a water-soluble lubricant according to an embodiment of the present disclosure can be applied to the water-soluble lubricant supply system according to the embodiment of the present disclosure described above. In the water-soluble lubricant supply system according to an embodiment of the present disclosure, the location where the method for sterilizing a water-soluble lubricant according to an embodiment of the present disclosure is applied is not particularly limited. The method for sterilizing a water-soluble lubricant according to an embodiment of the present disclosure may be applied to any location where a water-soluble lubricant is present in the water-soluble lubricant supply system according to an embodiment of the present disclosure.

[0111] For example, in a water-soluble lubricant supply system according to one embodiment of the present disclosure, (i) the sterilization method for a water-soluble lubricant according to one embodiment of the present disclosure may be applied to the water-soluble lubricant flowing through the pipelines, (ii) the sterilization method for a water-soluble lubricant according to one embodiment of the present disclosure may be applied to dirty liquid or clean liquid stored in a dirty tank or a clean tank, (iii) the sterilization method for a water-soluble lubricant according to one embodiment of the present disclosure may be applied to water-soluble lubricant present in other locations in the water-soluble lubricant supply system according to one embodiment of the present disclosure, or (iv) (i) to (iii) may be used in combination. From the viewpoint of sterilization efficiency, it is preferable that the sterilization method for a water-soluble lubricant according to one embodiment of the present disclosure is applied to at least the water-soluble lubricant flowing through the pipelines.

[0112] Furthermore, visible light with a wavelength of 380 to 420 nm may be irradiated onto the water-soluble lubricant in the machining space of a metal processing device (e.g., machine tool 50 in lubricant supply system 1) to which the water-soluble lubricant is supplied from the water-soluble lubricant supply system according to one embodiment of the present disclosure. Because the water-soluble lubricant floats in the machining space of the metal processing device in the form of a mist, the visible light is scattered by the mist particles, which has the advantage of enhancing the sterilization effect. Furthermore, by providing a visible light source that irradiates visible light with a wavelength of 380 to 420 nm in the machining space of the metal processing device, the visible light source can be used not only for sterilization of the water-soluble lubricant but also for illumination within the machining space.

[0113] [Summary] A water-soluble lubricant supply system according to a first aspect of the present invention comprises a water-soluble lubricant storage section that stores a water-soluble lubricant, a pipeline that circulates the water-soluble lubricant stored in the water-soluble lubricant storage section, a pump that is provided in the pipeline and circulates the water-soluble lubricant from the water-soluble lubricant storage section to the pipeline, and at least one of an ultraviolet irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with ultraviolet light, and a visible light irradiator that is provided in the pipeline and irradiates the water-soluble lubricant circulating through the pipeline with visible light having a wavelength of 380 to 420 nm, wherein the ultraviolet irradiator has an ultraviolet light source that is either an ultraviolet light emitting diode or an excimer light emitting ultraviolet lamp, or a combination of these, and the visible light irradiator has a visible light source that irradiates visible light having a wavelength of 380 to 420 nm.

[0114] This makes it possible to provide a water-soluble lubricant supply system equipped with at least one of an ultraviolet irradiation unit and a visible light irradiation unit that has a high sterilization effect. Furthermore, because these ultraviolet light sources and visible light sources are compact, there is no need to prepare large-scale devices for ultraviolet and visible light irradiation. Furthermore, these ultraviolet light sources and visible light sources can be placed inside the pipelines of the water-soluble lubricant supply system. Therefore, a more effective sterilization effect can be achieved through the synergistic effect of irradiating the water-soluble lubricant in the pipelines with ultraviolet or visible light and contacting the water-soluble lubricant with the ultraviolet or visible light source to irradiate ultraviolet or visible light from inside the water-soluble lubricant.

[0115] In the water-soluble lubricant supply system according to Aspect 2 of the present invention, in the above-mentioned Aspect 1, it is preferable that the ultraviolet light source is a light source that emits deep ultraviolet light. This makes it possible to obtain a higher sterilization effect.

[0116] A water-soluble lubricant supply system according to Aspect 3 of the present invention is preferably the water-soluble lubricant supply system of Aspects 1 or 2, wherein the ultraviolet light source is an ultraviolet light-emitting diode that emits deep ultraviolet light. Ultraviolet light-emitting diodes are small and therefore easily applicable to existing water-soluble lubricant supply systems, have a smaller environmental impact than mercury-based ultraviolet lamps, and can be made smaller and have a longer life.

[0117] A water-soluble lubricant supply system according to Aspect 4 of the present invention is any one of Aspects 1 to 3 above, wherein the pipeline is provided with a filter for removing foreign matter from the water-soluble lubricant, and the ultraviolet light irradiation unit and the visible light irradiation unit are preferably provided inside the pipeline and downstream of the position where the filter is provided. Once the water-soluble lubricant has passed through the filter, foreign matter has been removed to a certain extent and transparency has been improved, making it easier for ultraviolet light and visible light to pass through, and making it easier to demonstrate the effects of ultraviolet light irradiation and visible light irradiation.

[0118] A water-soluble lubricant supply system according to a fifth aspect of the present invention is the water-soluble lubricant supply system of any one of the first to fourth aspects, wherein the water-soluble lubricant storage section has a first storage section for storing contaminated liquid and a second storage section for storing clean liquid, the conduit is a conduit for agitating the contaminated liquid in the first storage section by sucking the contaminated liquid from one end and discharging it from the other end into the first storage section, and the first conduit is provided with a first filter for generating secondary contaminated liquid from the primary contaminated liquid sucked from the first storage section. and a second pipeline for circulating the water-soluble lubricant from the first reservoir to the second reservoir, the second pipeline having a first filter for producing secondary contaminated fluid from primary contaminated fluid sucked from the first reservoir, and a second filter downstream of the first filter for producing clean fluid from the secondary contaminated fluid, wherein the ultraviolet light source and the visible light source of the ultraviolet irradiation unit and the visible light irradiation unit are preferably provided at at least one of the following locations (a) to (c): (a) a position inside the first pipeline and downstream of the position where the first filter is provided; (b) a position inside the second pipeline and between the first filter and the second filter; and (c) a position inside the second pipeline and downstream of the position where the second filter is provided.

[0119] Once the water-soluble lubricant has passed through the filter, foreign matter has been removed to a certain extent and the transparency has been improved, so that ultraviolet and visible light can pass through more easily, and the effects of ultraviolet and visible light irradiation can be more easily exhibited.

[0120] A water-soluble lubricant supply system according to Aspect 6 of the present invention is the water-soluble lubricant supply system according to Aspect 5 above, wherein the ultraviolet light source and the visible light source are preferably provided inside the first pipeline and downstream of the position where the first filter is provided. This allows ultraviolet light and visible light to be irradiated onto the secondary contaminated fluid. Compared to irradiating the clean fluid with ultraviolet light and visible light, the secondary contaminated fluid contains a moderate amount of foreign matter such as metal powder, which makes it easier for ultraviolet light to be scattered, resulting in an even greater sterilization effect.

[0121] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0122] 1 Water-soluble lubricant supply system 10 Water-soluble lubricant storage section 101 Dirty tank (first storage section) 102 Clean tank (second storage section) 20 Pipe 201 First pipe 202 Second pipe 203 Third pipe 204 Fourth pipe 30, 301, 302, 303 Pump 40, 401, 402, 403, 404, 140 Ultraviolet irradiation section 41, 411, 412, 413, 414, 141 Ultraviolet light source 50 Machine tool 101 Dirty tank (first storage section) 102 Clean tank (second storage section) 60 Filter 601, 602 First filter 603 Third filter 604 Second filter 2011, 2021, 2031 Suction side pipe line 2012, 2022, 2032 Discharge side pipe line

Claims

1. A water-soluble lubricant supply system comprising: a water-soluble lubricant storage section for storing a water-soluble lubricant; a pipeline for circulating the water-soluble lubricant stored in the water-soluble lubricant storage section; a pump provided in the pipeline for circulating the water-soluble lubricant from the water-soluble lubricant storage section to the pipeline; and at least one of an ultraviolet irradiator provided in the pipeline for irradiating the water-soluble lubricant circulating through the pipeline with ultraviolet light, and a visible light irradiator provided in the pipeline for irradiating the water-soluble lubricant circulating through the pipeline with visible light having a wavelength of 380 to 420 nm, wherein the ultraviolet irradiator has an ultraviolet light source which is either an ultraviolet light emitting diode or an excimer light emitting ultraviolet lamp, or a combination of these, and the visible light irradiator has a visible light source which irradiates visible light having a wavelength of 380 to 420 nm.

2. The water-soluble lubricant supply system according to claim 1, wherein the ultraviolet light source is a light source that emits deep ultraviolet light.

3. A water-soluble lubricant supply system according to claim 1 or 2, wherein the ultraviolet light source is an ultraviolet light-emitting diode that emits deep ultraviolet light.

4. A water-soluble lubricant supply system as set forth in any one of claims 1 to 3, wherein the pipeline is provided with a filter for removing foreign matter from the water-soluble lubricant, and the ultraviolet light source and the visible light source are provided inside the pipeline and downstream of the position where the filter is provided.

5. The water-soluble lubricant storage section has: a first storage section for storing dirty fluid; and a second storage section for storing clean fluid; and the conduit includes: a first conduit for agitating the dirty fluid in the first storage section by sucking the dirty fluid from one end and discharging it from the other end into the first storage section, the first conduit being provided with a first filter for producing secondary dirty fluid from the primary dirty fluid sucked from the first storage section; and a second conduit for circulating the water-soluble lubricant from the first storage section to the second storage section, the second conduit being provided with a first filter for producing secondary dirty fluid from the primary dirty fluid sucked from the first storage section and a second filter downstream of the first filter for producing clean fluid from the secondary dirty fluid; and the ultraviolet irradiating section and the visible light irradiating section are configured such that the ultraviolet light source and the visible light source are provided in at least one location selected from the group consisting of the following (a) to (c):

5. The water-soluble lubricant supply system according to claim 1, wherein: (a) a position inside the first pipeline and downstream of a position where the first filter is provided; (b) a position inside the second pipeline and between the first filter and the second filter; and (c) a position inside the second pipeline and downstream of a position where the second filter is provided.

6. The water-soluble lubricant supply system according to claim 5, wherein the ultraviolet light source and the visible light source are provided inside the first pipeline and downstream of the position where the first filter is provided.

7. The water-soluble lubricant supply system according to claim 1, wherein the visible light source is a light source that emits visible light with a wavelength of 405 nm.

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