JP2022140179A - Method of continuously reproducing grinding face of rubber grinding stone or grinding wheel by action of ejection of fine air bubble and its device, griding/polishing grinder for improving property of surface ground layer of material to be ground, cavitation ejection nozzle for grinding wheel and automatic grinding operation method - Google Patents

Abstract

To provide a method of reproducing a grinding face of rubber grinding stone or else which applies erosion action (cavitation peening) of fine air bubble, and to provide a grinding technique which gives excellent results of grinding for improving properties of a ground surface layer of material to be ground due to compression explosion of the fine air bubbles.SOLUTION: A ground face reproducing method with respect to a rubber grinding stone face according to erosion action which occurs when ejecting fine air bubbles 1a produced by a cavitation generation device 100 onto a grinding face 11a of a rubber grinding stone GT (11) is provided, and a continuously grinding face reproducing method of the rubber grinding stone which ejects fine air bubbles onto an outer circumferential face of the grinding stone to wash/erose the face, and expose and reproduce abrasive grains G in a rubber grinding stone inner layer onto the grinding face when ejecting the fine air bubbles toward the outer circumferential face of the grinding stone in which the abrasive grains G are filled within the rubber grinding stone.SELECTED DRAWING: Figure 1

Description

The present invention relates to the grinding and polishing of machine tools, particularly to a new grinding technology for grinding machines, and is a further technological innovation in the conventional examples in which microbubble coolant liquid (microbubbles) or the like is used for grinding and polishing. In particular, a novel method for regenerating the grinding surface of a grinding wheel mainly composed of a rubber grindstone, and a shock wave generated when the microbubbles collapse at the grinding point.・With the new use of impact force, in addition to improving surface properties by shot peening, abrasive grains in the inner layer of the grinding wheel are exposed and remolded on the grinding surface. Furthermore, the present invention relates to an epoch-making technology that exhibits a new grinding effect of improving the properties of the machined surface of the work material by forming a surface grinding layer of the work material at the point of grinding and polishing, by means of an automatic grinding operation method.

In recent years, there have been reports of attempts to use microbubble coolant liquids (microbubbles) for grinding and polishing, and test examples and examples based on the results of this research.
For example, in the 2007 Precision Machinery Engineering Spring Conference Scientific Lecture Proceedings, "Research on Microbubble Coolant 1st Report: Application to Grinding Fluid", a micro/nanobubble coolant made with a microbubble generation mechanism Test results and actual effects of spraying the liquid onto the grinding wheel are described. The effects are: ・Improvement of cooling effect of machining fluid ・Improvement of chip cleaning effect ・Reliable supply of machining fluid to the machining point ・Reduction of machining fluid supply volume ・Control of tool wear ・Improvement of surface roughness ・Machining It was confirmed that suppression of liquid putrefaction could be measured. (For example, see Technical Paper 1 of Non-Patent Document).

In addition, in the 2017 Precision Machinery Engineering Spring Conference Scientific Lecture Proceedings, "Study on Removal Machining Using Micro/Nano Bubble Coolant", schematic diagrams of applications to microbubble generators and grinders are disclosed. . Then, the effect of sub-micron order bubbles on grinding performance is disclosed. According to this, when a micro-nano bubble coolant with a sub-micron order bubble diameter is applied to the surface grinding of hardened steel with a general grindstone, it will remain in the coolant for a long period of time. It was found to be suitable for surface grinding of hardened steel. And when the micro/nano bubble coolant liquid (microbubbles) is used for grinding and polishing, 1, the processing time is shortened. 2. Increased depth of cut. 3. It is reported that it is clear that it contributes to the improvement of tools, grinding wheel life, machining accuracy, etc. (for example, see technical paper 2 of non-patent literature).

On the other hand, Yukio Ito, one of the inventors of the present application, published Japanese Patent No. 5574243 titled "Grinding Method and Grinding Apparatus Using Bubble Coolant Liquid", which utilizes a bubble coolant liquid having a function to improve grinding performance. A grinding method, a grinding apparatus, and a processing apparatus that are related to past development technology and that use a foamed coolant liquid.
In particular, the grinding method and the grinding apparatus are characterized in that in the grinding method using the foamed coolant liquid according to claim 1 of the present invention, the inert gas penetrates from the center of the electrodeposited grindstone into the grindstone and is ejected to the outer peripheral surface of the grindstone. By injecting a strong alkaline liquid mixed with a natural soap-based foaming agent from both sides of the grinding wheel to the processing point on the outer peripheral surface, the bubble phenomenon can be easily caused by the principle of a vaporizer to create a foamed coolant liquid. As a result, the foamed coolant surrounds the entire outer peripheral surface of the electrodeposited grindstone in an oxygen-free state, and the grinding grindstone and workpiece can be cooled and the grinding wastes can be adsorbed. As a result, the cooling lubricating liquid is bubbled without scattering of the grinding liquid, and a small amount of lubrication can be performed at the grinding point. In addition, the strong alkaline liquid provides high anti-corrosion, cleaning, and anti-corrosion effects. Furthermore, due to the high grinding dust adsorption effect of the natural soap-based foaming agent water and the high gas-liquid separation property, separation of grinding dust and maintenance of cleanliness of the coolant liquid, which are post-treatments, can be expected (for example, Patent Document 1 reference).

In addition, the metal surface is strengthened and improved by compressive rupture (cavitation peening) effect caused by the shock wave generated when the bubbles of the micro/nano bubble coolant liquid (microbubbles) are destroyed. However, Journal of Abrasive Processing Society Vol65 No2 2021 FEB. pp. 70-73, featured in the special feature "Compressive Residual Stress Application Technology by Peening". FIG. 1 in the article shows a schematic diagram of changes in cavitation bubbles. The effect is that cavitation is generated at the tip of a nozzle that injects a high-speed water jet. FIG. 2 shows an underwater cavitation jet and an air cavitation jet, and FIG. 3 shows an example of processing by a cavitation peening device. (For example, see Technical Paper 3 of Non-Patent Literature).

Finally, one of the published patents is "Grinding Fluid Supply Device, Grinding System, Grinding Method and Cavitation Processing Module Used Therefor".
The content of this technology is that in the processing of metal products by grindstone grinding, clogging of the grindstone can be dramatically improved by a simple liquid treatment, and continuous processing can be continued even if the depth of cut of the grindstone is significantly increased compared to conventional methods. It is a grinding fluid supply device that makes it possible and, in turn, greatly contributes to the improvement of the efficiency of grinding.
A specific solution is to circulate the aqueous grinding fluid CL through the aggregate of the treatment medium particles, so that the aqueous grinding fluid CL contacts the surfaces of the treatment medium particles and is subjected to cavitation treatment, and then supplied to the grinding apparatus 100. be done. The insulating ceramic that forms the processing medium particles is porous with a porosity of 10% or more and 60% or less, and has an apparent specific gravity of 1.0 or more, so that it is stable without floating in the casing. It comes into contact with the water-based grinding fluid CL at the flow rate. As a result, cavitation occurs on the surface of the treatment medium particles, in which dissolved air in the aqueous grinding fluid CL precipitates under reduced pressure, and the permeability of the aqueous grinding fluid CL to the surface of the grindstone 101 is improved (for example, Patent Document 2 reference).

Technical paper 1 of non-patent literature

Proceedings of the 2007 Precision Machinery Engineering Spring Conference

Technical paper 2 of non-patent literature

Proceedings of the 2017 Precision Machinery Engineering Spring Conference

Technical paper 3 of non-patent literature

Journal of Abrasive Processing Society Vol65 No2 2021 FEB. 70-73

Patent document 1

Japanese Patent No. 5574243
Japanese Patent Application Laid-Open No. 2020-203332

Technical paper 1 of the above non-patent literature, "Research on Microbubble Coolant 1st Report: Application to Grinding Fluid" described in the 2007 Precision Machinery Spring Conference Scientific Lecture Proceedings, is a microbubble generation mechanism. By injecting the micro/nano bubble coolant into the grinding wheel, it is possible to: ・Improve the cooling effect of the machining fluid ・Improve the cleaning effect of chips ・Reliably supply the machining fluid to the machining point ・Amount of machining fluid supplied reduction of tool wear, improvement of surface roughness, and suppression of machining fluid spoilage.
However, even if the roughness of the ground surface of the work material can be improved, the machined surface properties such as dimensional accuracy and surface hardness of the ground surface are not improved. In other words, the action and effect of the micro-nanovalve coolant liquid is limited to that it is mirror-finished.

Technical paper 2 of the above non-patent document, "Research on removal processing using micro-nano bubble coolant" described in the 2017 Precision Mechanical Engineering Spring Conference academic lecture collection, is the above-mentioned micro-nano bubble coolant liquid (fine bubbles). When used for grinding and polishing, 1. Reduces processing time. 2. Increased cutting depth. 3. Although it contributes to the improvement of tool life, grinding wheel life, processing accuracy, etc., it especially eliminates adhesives that bury the abrasive grains exposed on the outer peripheral surface of the rubber grinding wheel, and improves the dimensional accuracy and surface hardness of the grinding surface. It does not contribute much to the improvement of the machined surface properties.

Abrasive Machining Society Journal Vol65 No2 2021 FEB. 70-73 "Increase in strength of steel gears by cavitation peening" is an impact force (imparting compressive residual stress) to the surface of metal materials due to the rupture erosion caused by the cavitation peening action of micro-nano bubble coolant liquid (fine bubbles). This will improve the surface of the product (work hardening). For example, although the strength of steel gears can be increased (improved fatigue strength), the increase in surface roughness causes a reduction in machining accuracy.

In addition, Japanese Patent No. 5574243, "Grinding Method and Grinding Apparatus Using Foamed Coolant Liquid", has a high grinding dust adsorption effect and high gas-liquid separation performance, resulting in separation of grinding dust and cleanliness of the coolant liquid, which are post-treatments. Although this can be expected to be maintained, the properties of the machined surface such as the surface hardness of the ground surface cannot be improved when the workpiece is polished.

In the last Japanese Patent Application Laid-Open No. 2020-203332, "Grinding liquid supply device, grinding system, grinding method, and cavitation processing module used therefor", the surface hardness of the grinding surface is increased even when the workpiece is polished. Conversely, the machined surface quality deteriorates.

The object of the present invention is to solve the problem that the surface hardness of the ground surface due to the grinding accuracy and compression rupture (cavitation peening) of the conventional micro/nano bubble coolant liquid (fine bubbles) is enhanced, but the machined surface properties are reduced. It is made in view of the points.
That is, due to bubble collapse/compression rupture (cavitation peening) possessed by micro/nano bubble coolant liquid (fine bubbles), grinding surface regeneration method (dressing method) such as rubber grindstone, its device, and micro/nano bubble coolant liquid (fine bubbles ) bubble collapse (cavitation peening) and the combined action of the grinding process immediately after this, improving the properties of the surface grinding layer of the work material. is.

A glossary of terms used in the present invention.
▲１▼ What is erosion?
Bubbles near the surface stick to each other due to viscosity and surface tension, and at the moment of disappearance, a strong pressure wave is generated at the center of the bubble, causing damage to the metal.
(2) Microbubbles are defined in ISO 20480-1:2017.
Fine bubbles are all bubbles with a diameter of 100 μm or less, microbubbles are bubbles with a diameter of 1 to 100 μm, and micro/nanobubbles are bubbles with a diameter of several tens to hundreds of nanometers.
(3) Cavitation peening is a term used in surface modification methods such as shot peening, in which shock waves and impact forces are generated at the time of compression bursting action during bubble collapse.

Claim 1 of the present invention is a method for regenerating a grinding surface for a grinding wheel surface by a cleaning action that occurs when microbubbles produced by a cavitation generator are injected onto the grinding surface of a grinding wheel on a grinding machine, wherein the microbubbles are injected. The cavitation injection nozzle ejects the fine bubbles toward the outer peripheral surface of the grinding wheel to remove the grinding debris on the surface layer of the grinding wheel and expose the abrasive grains to the grinding surface. This is a method for constantly regenerating a ground surface.

A second aspect of the present invention is a method for constantly regenerating a grinding surface of a grinding wheel by jetting microbubbles according to the first aspect, wherein, when the grinding wheel is a rubber grindstone, the microbubbles are jetted from a cavitation jet nozzle onto the outer peripheral surface of the rubber grindstone. is characterized by exposing the abrasive grains on the grindstone surface by peeling off the thermosetting resin, which is the binding agent for the rubber grindstone surface with a smooth surface, and remolding a new satin surface on the rubber grindstone.

Claim 3 is the method for constantly regenerating the grinding surface of a rubber grindstone or grinding wheel by the jetting action of microbubbles according to any one of claims 1 and 2, wherein the microbubbles generated by the cavitation generator are generated in the cavitation generator. Continuous uniform pressure is discharged from the cavitation injection nozzle when the accumulator is interposed, and pulsating injection is performed when the accumulator is not interposed. is.

Claim 4 is the apparatus for constantly regenerating the grinding surface of a rubber whetstone or a grinding wheel according to claim 3, wherein the water pressure and water volume of microbubbles generated by the cavitation generator, the on/off of pulsating jet, and the size of the microbubbles. Settings, etc. are the constant grinding surface regeneration device for the rubber whetstone and the grinding whetstone, which governs the function setting of the cavitation generator according to the command signal from the NC control device.

In claim 5, the cavitation injection nozzle for injecting fine air bubbles jets fine air bubbles toward the outer peripheral surface of the rubber whetstone or the grinding whetstone and the grinding surface where the outer peripheral surface of the rubber whetstone or the grinding whetstone is in contact with the material to be ground. The fine bubbles are sprayed onto the outer peripheral surface of the grinding wheel and the grinding surface in contact with the material to be ground. Fine bubbles injected into the grinding layer are collapsed and eaten by the rubber grindstone or the grinding force of the grinding wheel, and shock waves and impact forces are generated when the bubbles collapse, and surface modification such as shot peening is attempted, and the rubber grindstone is used. The abrasive grains of the inner layer or the inner layer of the grinding wheel are exposed and remolded on the grinding surface, and the processed surface properties of the work material are ground and polished with high precision.

According to claim 6, in the grinding apparatus according to claim 5, the cavitation injection nozzle for injecting the microbubbles injects microbubbles toward the grinding surface where the outer peripheral surface of the rubber whetstone or the grinding whetstone is in contact with the material to be ground. It is characterized by having only a book.

The grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 7 is the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 5 and claim 6. , The microbubbles produced by the cavitation generator are discharged from the cavitation injection nozzle at a continuous uniform pressure when the accumulator in the cavitation generator is interposed, and are pulsatingly injected when the accumulator is not interposed. and

The grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 8 is the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 7, wherein the cavitation is The setting of the generator, such as water pressure, water volume, on/off of pulsating jet, fine bubble size setting, etc., is performed by a command signal from the NC controller that controls the function setting of the cavitation generator.

According to claim 9, there is provided a cavitation injection nozzle in the method and apparatus for constantly regenerating a ground surface of a rubber grindstone or grinding wheel according to claims 1 to 4, wherein the cavitation injection nozzle is composed of inner and outer double cylinders. Ultra high pressure water is supplied to the inside of the cylinder, and high pressure water is supplied to the space of the outer circumferential annular cylinder. The outer periphery of the ultra-high pressure column presents annular micro-bubbles, the outer periphery of the micro-bubbles is a triple annular jet of low-pressure water, and the ultra-high pressure column in the center is grinding dust adhering to the outer peripheral surface of the grindstone. The ring-shaped fine bubbles erode the outer peripheral surface of the grinding wheel, and the ring-shaped low-pressure water cleans the eroded grinding dust and peeled adhesive on the outer peripheral surface of the wheel. characterized by

The cavitation injection nozzle of claim 10 is the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claims 5 and 6, wherein the cavitation injection nozzle comprises an inner and outer double cylinder. By supplying ultra-high pressure water to the center side cylinder and low pressure water to the space of the outer circumference side ring cylinder, the jet water jetted from the cavitation jet nozzle is applied to the grinding surface of the grindstone by: The central portion presents an ultra-high pressure column, the outer periphery of the ultra-high pressure column presents annular fine bubbles, and the outer periphery of the fine bubbles is characterized by a triple annular jet of annular low-pressure water.

The automatic grinding operation method of claim 11 is characterized in that, in the NC control device that controls the grinding of claims 4 and 8, selection of a grinding wheel for a material to be ground, selection of microbubbles, selection of a grinding surface and a workpiece during grinding work, Detection of the surface condition of the grinding material, image detection of the surface shape of the grinding wheel surface and the material to be ground after grinding, comprehensive judgment of the surface shape of the grinding wheel surface and the material to be ground after grinding, and determination of the defective grinding material to the grinding wheel It is characterized by feeding back to the selection process and repeating the grinding work again.

According to the method for constantly regenerating the grinding surface of a grinding wheel by the action of injecting microbubbles according to claim 1, the cavitation injection nozzle for injecting microbubbles injects the microbubbles toward the outer peripheral surface of the grinding wheel to grind. Since the grinding debris on the surface layer of the grinding wheel is removed and the abrasive grains are exposed and regenerated on the grinding surface, the grinding debris and other substances that clog the surface of the grinding wheel are blown away, and the abrasive grains in the inner layer of the grinding wheel are always exposed and regenerated on the grinding surface. , the surface of the grinding wheel is constantly dressed and cleaned, and the grinding action can be promoted with high efficiency. As a result, the machined surface properties of the machined surface of the work material can be improved with high accuracy.

According to the method for constantly regenerating the grinding surface of a rubber grindstone by the jetting action of microbubbles according to claim 2, the grinding shavings and the like that tend to clog the rubber surface are blown off, and the abrasive grains in the inner layer of the grinding wheel are constantly exposed to the grinding surface and regenerated. , The surface of the clogged rubber whetstone is constantly dressed and cleaned, and the grinding action can be promoted with high efficiency. As a result, the quality of the machined surface of the material to be machined by the rubber whetstone can be improved with high accuracy.

Claim 3 is a method for constantly regenerating a grinding surface of a rubber whetstone or a grinding wheel by the jetting action of microbubbles according to any one of claims 1 and 2 above, wherein the microbubbles generated by the cavitation generator are injected into the cavitation generator. When an accumulator is interposed, it is discharged from the cavitation injection nozzle at a continuous uniform pressure. It is possible to greatly promote the removal of grinding debris corresponding to the clogging of the grindstone surface, and to further improve the grinding efficiency and the ground/machined surface properties of the work material with the rubber grindstone or grinding grindstone with high accuracy.

Claim 4 is the apparatus for constantly regenerating the grinding surface of a rubber whetstone or a grinding wheel according to claim 3, wherein the water pressure and water volume of microbubbles generated by the cavitation generator, the on/off of pulsating jet, and the size of the microbubbles. Since the function of the cavitation generator is controlled by the command signal from the NC control device, the injection amount and other conditions for the outer circumferential surface of the grindstone can be freely selected. As a result, it is possible to adaptively control the removal of grinding waste and rubber agent according to the clogging of the grinding surface and the exposure of the rubber grinding wheel on the grinding surface of the rubber grinding wheel. Efficiency and surface quality of the ground surface can be maintained and improved with high accuracy.

In claim 5, fine air bubbles of the cavitation injection nozzle are injected to the surface of the rubber whetstone or the grinding whetstone and also to the grinding surface of the material to be ground and polished by the rubber whetstone or the grinding whetstone, so that the rubber whetstone or the grinding whetstone is applied. Since it is a surface-grinding layer grinding machine for abrasives, the rubber whetstone or the outer peripheral surface of the grinding whetstone is constantly dressed and cleaned so that the abrasive grains of the inner layer of the rubber whetstone or the inner layer of the whetstone can be exposed and regenerated on the grinding surface. When microbubbles are injected at high speed toward the grinding surface where the outer peripheral surface of the grindstone contacts the material to be ground, the outer peripheral surface of the rubber grindstone or the grinding wheel and the surface grinding layer of the material to be ground. Due to the compression grinding force, the fine bubbles are collapsed by the bubble compression grinding force, generating a shock wave and impact force when the bubbles collapse, aiming for surface modification by shot peening action. Furthermore, the abrasive grains in the inner layer of the rubber whetstone or the inner layer of the grinding whetstone are exposed and reproduced on the grinding surface, and as a result, the surface properties of the work can be ground, polished and improved with high accuracy.

In claim 6, in the grinding apparatus of claim 5, the cavitation injection nozzle for injecting the fine bubbles may be one that injects the fine bubbles toward the grinding surface where the outer peripheral surface of the grindstone is in contact with the material to be ground. First, microbubbles are sprayed onto the outer peripheral surface of the grindstone, which is constantly dressed and cleaned to expose and regenerate the abrasive grains in the inner layer of the grindstone on the grinding surface. Microbubbles are also sprayed onto the outer peripheral surface of the grindstone, causing the microbubbles to collapse and eat the surface grinding layer of the material to be ground. Can be ground and polished.

The above claim 7 is the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to the above claims 5 and 6, wherein the fine bubbles created by the cavitation generator are accumulated in the cavitation generator. When an accumulator is interposed, it is discharged from the cavitation injection nozzle at a continuous uniform pressure, and when an accumulator is not intervened, it becomes a pulsating injection. can be selected, the removal action corresponding to the clogging condition can be greatly improved and accelerated, and the machining efficiency and machined surface properties of the work material can be improved with high accuracy.

According to the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to the above claim 8, in the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to the above claim 7, the cavitation occurs. The water pressure, water volume, pulsating jet on/off, and fine bubble size settings, which are the device settings, can be freely set by command signals from the NC controller that controls the function settings of the cavitation generator. The injection amount can be arbitrarily selected according to the optimum conditions for the outer peripheral surface and the grinding surface. As a result, it is possible to improve the efficiency of grinding the work material and the quality of the ground surface with high accuracy.

Claims 9 and 10 are based on Claims 1 to 4 and Claims 6 to 7, in which the cavitation injection nozzle can emit triple ring-shaped injection water even with a single structure. When high-pressure water is supplied, low-pressure water is supplied into the space of the outer circumferential annular cylinder. An ultra-high pressure column is present, and the periphery of the ultra-high pressure column presents annular microbubbles, and the periphery of the microbubbles can be dividedly supplied with annular low-pressure water. With this, fine and highly accurate fine air bubbles are jetted corresponding to each grinding/polishing part, and the grinding efficiency and grinding surface properties for the outer peripheral surface of the rubber grinding wheel or grinding wheel and the work material are dramatically improved. can be improved to

According to the automatic grinding operation method of claim 11, the grinding wheel selection for the material to be ground, the selection of microbubbles, the grinding surface during the grinding operation and the surface of the material to be ground State detection, image detection of the surface shape of the grinding wheel surface and material to be ground after grinding, comprehensive judgment of the surface shape of the grinding wheel surface and material to be ground after grinding, and feedback of defective grinding material to the grinding wheel selection process. Since the grinding work is repeated again, automatic selection of the grinding wheel for the material to be ground, selection of water pressure and water volume of fine bubbles, detection of the grinding state during grinding, judgment of quality and failure after grinding. Re-grinding of non-defective whetstones and materials to be ground can be performed automatically. In addition, the automatic grinding operation ensures uniform quality for the material to be ground.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall view of a device for constantly regenerating a ground surface of a rubber whetstone or a hard whetstone and a grinding device for improving properties of a surface grinding layer of a work material in the first embodiment of the present invention; 1 is a schematic cross-sectional view of a cavitation nozzle in the first embodiment of the present invention; FIG. FIG. 2 is a diagram showing the injection state of fine air bubbles from a cavitation nozzle to a rubber whetstone or a grinding whetstone in an embodiment of the present invention; FIG. 4 is a cross-sectional view of the action of pulsating cavitation peening of microbubbles on the surface of the material to be ground in the embodiment of the present invention. FIG. 2 is a diagram showing the action of regenerating a ground surface of a rubber grindstone and a hard grindstone (vitrified grindstone) in an embodiment of the present invention. FIG. 5 is a diagram showing the action of dressing with pulsating microbubbles on a rubber grindstone or a hard grindstone in an embodiment of the present invention. FIG. 4 is a functional diagram of a cavitation generator for constant microbubbles and pulsating microbubbles according to an embodiment of the present invention; FIG. 8 is a cross-sectional view of the operation of compression peening of microbubbles between the work material and the grindstone in the second embodiment of the present invention. FIG. 10 is a diagram of a grinding operation of a blade with a rubber grindstone or a hard grindstone in the third embodiment of the present invention; BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram of an invention technique, generally showing each embodiment of the present invention; FIG. 11 is a flowchart of program creation in the NC control device in the fourth embodiment of the present invention;

1 to 11, each embodiment of the present invention will be described in sequence.

First, FIG. 1 shows an overall view of the system for improving the properties of the surface grinding layer of the workpiece Y using a cavitation generator 100 and a rubber grindstone 11 (GT).
First, the cavitation generator 100 is composed of substantially the same components as those of known devices. A tank 2 for storing the coolant 1 is provided with a suction pump P, and a motor M driving the pump P controls a filtration filter 3, a regulator 4, a plunger valve 5, and a drain 6 thereof when pumping up the coolant 1. , a bypass valve 7 for the compressed coolant liquid 1, and an accumulator 8 for smoothing the pulsating coolant liquid 1, and are attached to the rotating shaft of the external grinder 10 via a pipe 9. A bubble injection nozzle N is provided in the upper space of the rubber whetstone 11 . As shown in FIG. 1(b), the bubble injection nozzle N is provided at two locations: a nozzle N1 above the rubber whetstone 11 and a nozzle N2 directed toward a portion of the grinding whetstone 11 that bites into the workpiece Y in the rotation direction. are placed. The operation of the cavitation generator 100 is controlled by an NC controller 50. As shown in FIG. (Detailed functions will be described later).

1(b) and 1(c) show details of the rubber whetstone 11 (GT) and the portion that bites into the work material Y. FIG. That is, the microbubbles 1a from the nozzle N2 are directed toward the grinding surface Y1 where the rubber grindstone 11 (GT) bites into the work material Y, and the injected microbubbles 1a are used to cut the rubber grindstone 11 (GT) against the grinding surface Y1. The force causes bubble collapse, that is, bubble collapse K (details will be described later). The surface 11a of the grindstone 11 (GT) is also cleaned by spraying fine air bubbles 1a from the nozzle N1, so that the surface of the rubber grindstone is satinized and the abrasive grains G in the inner layer are exposed on the grinding surface 11a.

The structure of the bubble jetting nozzle N for jetting the fine bubbles 1a is substantially the same as the known structure as shown in FIG. The air bubble injection nozzle N is composed of inner and outer double cylinders P1 and P2. Ultrahigh-pressure water W1 discharged from the suction pump P of the cavitation generator 100 is supplied into the central cylinder P2, and low-pressure water W2 is supplied into the annular space of the outer circumferential annular cylinder P1. As shown in FIG. 3, the microbubbles 1a, which are jet water jetted from the bubble jetting nozzle N, exhibit an ultrahigh-pressure water column W1 at the center of the grinding surface 11a of the rubber grindstone 11 (GT). The outer circumference of the water W1 presents an annular microbubble 1a, and the outer circumference of the microbubble becomes a triple annular jet of annular low-pressure water W2.

As shown in FIG. 7, the ultrahigh-pressure water W1 discharged from the suction pump P of the cavitation generator 100 is discharged from the bubble injection nozzle N at a continuous uniform pressure P0 when the accumulator 8 in the cavitation generator 100 is interposed. However, when the accumulator 8 is not interposed, the pulsating injection pressure becomes PB. As shown in FIG. 3, any injection method corresponding to the outer peripheral surface 11a of the grindstone 11 can be selected for the pulsating microbubbles 1a. As a result, it is possible to greatly promote the action of removing grinding chips corresponding to the clogging of the grinding surface 11a of the rubber whetstone 11, and to further improve the machining efficiency and the machined surface properties of the grinding surface Y1 of the workpiece Y with high accuracy. Yes (details below).

The water pressure and water volume of the microbubbles 1a generated by the cavitation generator 100, the ON/OFF of the pulsating jet, and the size setting of the microbubbles 1a are controlled by a command signal (not shown) from the NC controller 50. It is governed by automatic driving (computer driving control technology AI) that governs function settings. That is, by the functions of computer operation control technology AI that the NC control device 50 has, automatic programming as shown in FIG. 11 and automatic operation are performed (details will be described later).

Next, an overview of program setting and automatic operation for automatic operation by the NC control device 50 will be described.
First, the procedure configuration of the grinding work, which is the automatic grinding operation method, will be described. For the NC control device 50 that controls grinding, selection of the grindstone for the material Y to be ground, selection of the microbubbles 1a, detection of the grinding surface Y1 during the grinding operation and the surface state of the material Y to be ground, and the grindstone after grinding Image detection of the surface and the surface shape of the material Y to be ground, comprehensive judgment of the grinding wheel surface 11a after grinding and the surface shape Y1 of the material Y to be ground, and feedback of the defective material to be ground to the grinding wheel selection process to perform the process again. Grinding work is repeated.

1 and 11, when the NC control device 50 is activated "start" S1 to set "selection of material to be ground ... rubber whetstone or grinding whetstone" S2, the following "water pressure/water volume・Each setting of presence/absence of pulsation and size of microbubbles” S3, “status detection” S6 of “rubber wheel GT” S4 or “status detection” S7 of “grinding wheel BT” S5, or “work material Y” S6 "state detection" S8. At this time, a remote sensor (not shown) that projects the roughness of the surface of the grindstone as an image using the reflected light from each grindstone detects an image (S8). ?” S9, S10, and S11 are judged, and if OK, “passed product by comprehensive judgment” S12 and “end” S13. If it is NG (failed product), it is fed back to "each setting of water pressure, amount of water, presence or absence of pulsation, and size of microbubbles" S3 to change the setting and try again. Finally, it is guided and controlled to a passing product.

Thus, the automatic selection of the rubber grindstone GT (11) or the hard grindstone BT for the material Y to be ground, the water pressure of the microbubbles 1a and other selections, and the automatic grinding operation after this, the quality of the material Y to be ground is kept uniform and guaranteed.

Subsequently, referring to FIGS. 3 to 5, grinding of the grindstone surface by cleaning action and collapsing action (cavitation peening) that occurs when microbubbles 1a created by the cavitation generator 100 are sprayed onto the grinding surface 11a of the grindstone 11 (GT). The surface regeneration method and the grinding action of the work material Y will be described below.
FIGS. 4(a), 4(b) and 4(c) show the decay phagocytosis (pulsation cavitation peening) of the surface Y1 of the work material Y acting simultaneously with regeneration of the ground surface on the grindstone surface by pulsating or constant-pressure microbubbles 1a. Each step is shown. First, when microbubbles 1a are jetted toward the grinding surface Y1 (a), the microbubbles 1a are jetted and collided with the surface Y1 of the work material Y by impact force (b), causing the surface layer Y1 to collapse and erode. At this time, the surface of the rubber grindstone 11 (GT) is also destroyed, and the adhesive layer of this surface layer is collapsed (c). As a result, the grinding surface 11a of the rubber grindstone 11 is also eroded by the microbubbles 1a, blowing off the bonding agent S and grinding dust sticking to the grinding surface 11a, and exposing and regenerating the abrasive grains G on the grinding surface. is executed.
Thus, when the bubbles collapse due to the injection, a compressive stress acts on the surface layer Y1 of the material Y to reinforce the ground surface. As a result, the abrasive grains G can be prevented from falling off unnecessarily during grinding of the grindstone surface, so that the grinding efficiency for the work material Y can be improved, and the method for constantly regenerating the ground surface of the rubber grindstone 11GT can be reliably carried out. Of course, the same applies to the hard grindstone BT.

More specifically, when the rubber grindstone GT (11) shown in FIG. 5(a) is used, the microbubbles 1a jetted from the cavitation jet nozzle N onto the outer peripheral surface of the rubber grindstone are sprayed onto the rubber with a smooth surface at high pressure. The thermosetting resin or rubber, which is the bonding agent S on the grindstone surface, is dropped and separated by the collision of the microbubbles 1a to form a satin finish. This collision causes erosion, exposing a large number of abrasive grains G on the grindstone surface, thereby regenerating the rubber grindstone with a recessed surface. Thus, the method of constantly regenerating the ground surface of the rubber grindstone GT (11) by the action of the micro-bubbles 1a, which promotes and maintains the grinding performance and the discharge performance of fine powder of grinding dust, can be reliably carried out. This effect can also be obtained in the hard grindstone (vitrified grindstone) BT shown in FIG. 5(b). Only the illustration is shown, and the description is omitted.

The characteristics of the rubber grindstone GT are as follows: No pores.・There is no chip pocket function.・The surface is smooth. • Elasticity (perfect recovery when unloaded).・Contact with work material Y is surface contact (surface machining). - The abrasive grains G do not protrude from the binder S.・It is extremely difficult to supply fine air bubbles 1a, which serve as coolant, into the grinding wheel.・Grinding is also possible, but polishing is our specialty.・It is necessary to design a flow path for supplying the cooling liquid inside the grindstone. However, in spite of this, the grinding performance of the rubber grindstone GT can be maintained. In addition, although the characteristics of the hard grindstone BT are explained in FIG. The surface cleaning action of is performed with high efficiency.

Again, the method for constantly regenerating the grinding surface of the rubber grindstone GT will be briefly described with reference to FIG. That is, the operation of the cavitation generator 100 will be described with the microbubbles 1a (PB) generated by (pulsating water jet peening) being the (discontinuous, non-uniform discharge) shown in FIG. First, in FIG. 6A, the abrasive grains G are buried invisible from the surface of the grindstone GT (11). and • The surface S of the whetstone is smooth and smooth. Therefore, as shown in FIG. 6(b), fine bubbles 1a of the pulsating water jet PB are jetted onto the grindstone surface. Then, as shown in FIG. 6(b), the jetted microbubbles 1a scatter the thermosetting resin or rubber, which is the binding agent S on the surface of the rubber grindstone GT (11) with a smooth surface, by imparting a disintegrating function. , a large number of abrasive grains G are exposed on the grindstone surface. As a result, the binder (rubber) S is scattered and scraped off. Then, • The abrasive grains G embedded in the rubber protrude from the surface layer of the rubber grindstone GT (11). In this way, the rubber, which is the smooth binder S, is ground and scattered, and the surface roughened like a satin finish is subjected to a dressing treatment.

As described above, the rubber grindstone GT (11) has a satin-like roughened surface due to the method of constantly regenerating the ground surface, and the coolant cooling liquid (microbubbles) 1a is caught in the roughened surface and supplied to Thus: • Chips are captured and ejected by the rough surface.・Although the satin-like binding material is worn away and becomes smooth with the processing, ・Abrasive grains G fall off and new abrasive grains are supplied. In addition, the fine air bubbles 1a, which are pulsating water jets, protrude and regenerate the worn abrasive grains G between working points. At this time, • The pulsation cycle, the discharge pressure, and the discharge amount are appropriately and timely controlled by the NC control device.・The system that comprehensively cooperates and integrates these is the constant grinding surface regeneration method. This action enables the vitrified grindstone BT to clean pores with high efficiency, which has not been possible in the past. Of course, substantially the same effects can be obtained with the microbubbles 1a at the uniform pressure P0.

Next, with reference to FIG. 5(b), the functions and actions of the method for constantly regenerating the grinding surface of the vitrified grinding wheel BT, which is the grinding wheel, will be described in detail. A vitrified grindstone BT, which is a hard grindstone, shown in FIG. The characteristics of this vitrified grindstone BT are: ・There are pores. • Pores serve as chip pockets.・The whetstone surface is rough (pear-skin). The whetstone is hard (hard).・The contact with the work material Y becomes a line (line processing). - The abrasive grains G protrude from the bonding agent S. - The microbubbles 1a serving as the coolant are stored in the pores E and supplied from there. • Grinding (also known as fine cutting).・Microscopic air bubbles 1a are stored in the depressions and can be supplied into the grindstone. etc. are obtained.
Furthermore, after the cooling liquid is supplied to the machining point, the microbubbles 1a envelop the chips, adsorb them, and efficiently discharge them to the outside. As a result, conventional rubber grindstones that do not have air bubbles exhibit "cooling properties" and "chip discharging properties" to suppress "grinding burn" and to obtain the effect of improving "processability" of the ground surface.

Next, the present invention applies microbubbles 1a produced by the cavitation generator 100 to the grinding surface Y1 of the material Y to be ground and polished by a rubber grindstone GT or a grinding grindstone (vitrified grindstone) BT. It is specified as a grinding apparatus that jets and improves the properties (fatigue strength, corrosion resistance, surface roughness, strength enhancement) of the surface grinding layer Y1 of the material to be ground, that is, the grinding surface Y1. 1 to 3, 5(a), 7, 8 and 9 will be described.

In FIG. 1, according to the present invention, the fine bubbles 1a from the cavitation injection nozzle N2 that injects the fine bubbles 1a created by the cavitation generator 100 are applied to the grinding surface Y1 where the grinding wheel 11 bites into the material Y to be cut. It is aimed at and sprayed to collapse and erode the processing point (grinding point).

In FIG. 8, the microbubbles 1a are PB or P0, which are jetted toward the rubber grindstone GP or the hard grindstone BT and the grinding surface Y1 in contact with the material Y to be ground. At this time, the microbubbles 1a jetted at high speed to the surface grinding layer of the material to be ground collapse (compressively collapse) by cavitation peening. That is, at the grinding point of the grindstone GP or BT, the abrasive grains G in the inner layer of the grindstone are exposed and regenerated by the compression grinding force F, and the processed surface properties of the work material Y are ground and polished with high precision and high hardness. That is, it is a type of cold working, and the inertial peening effect of improving the hardness of the surface layer of the processed surface and imparting residual stress is generated by the shock wave and impact when the fine bubbles 1a are sandwiched and compressed between the grindstone and the material Y to be ground, and the bubbles collapse. force is generated. As a result, "fatigue strength", "corrosion resistance", "surface roughness" and the like can be improved and the strength can be improved.

That is, to describe the above operation again, fine bubbles 1a are jetted toward the rubber grindstone GP or grinding grindstone BT and the grinding surface Y1 as shown in FIGS. 1(c) and 8(b). As a result, the microbubbles 1a enter between the surface of the grindstone and the grinding surface Y1 to generate compressive fracture KF, and the surface layer of the grinding surface, that is, the grinding surface, becomes as shown in FIG. 8(c). Strong compressive stress works to increase mechanical strength and reinforce.

The operation of the grinding apparatus for grinding and polishing the surface grinding layer of the work material to improve the properties will be described in detail again with reference to the example of blade surface processing of blade BL in FIG. 9, which is a specific workpiece. In the drawing, the grindstones GT and BT of the rotating shaft SP grind and polish the grinding surface Y1, which is the curved surface of the blade BL, with high precision and high precision. Feed to the point.・Especially when using the rubber grindstone GT, which has a smooth surface, the cooling liquid is thrown off by the air layer on the outer circumference as it rotates. However, according to the present invention, the surfaces of the grinding wheels GT and BT that have become rough return to their original smoothness due to wear as the abrasive grains G fall off. Maintain bubble 1a. - At this time, the microbubbles of the microbubbles 1a are sandwiched and compressed between the grindstones GT and BT and the work material BL, and the microbubbles 1a collapse. Thus, not only is the grinding surface Y1 efficiently and highly precisely ground, polished, and polished, but also the surface of the blade BL has improved "fatigue strength", "corrosion resistance", "surface roughness", etc. and strength. be done.

A general system of the invention technology that constitutes each embodiment of the present invention will be briefly described with reference to FIG. First, the development of the cavitation nozzle shape consists of plans (A), (B), and (C). As for the development of the bubbles, fine air bubbles 1a of plan (A) and plan (B) are obtained according to the nozzle shapes described above. Next, in the rubber grindstone GT, which is one of the developments of cavitation bubbles, fine bubbles 1a are jetted from the nozzle N, and plans (A) to (D) are obtained. Furthermore, according to cavitation bubble peening, it is possible to implement plans (A) to (D) for various work materials Y (SUS material test, actual blade test, actual machine test blade) on the grinding wheel 11 (GT). . The general technique described above encompasses the gist of the present invention.

The effects and effects of the example of blade surface processing of the blade BL are as follows: ・A compressive stress of about 1 mm is applied from the surface layer.・The fatigue strength of the machined surface is improved.・Extremely long service life of the machined surface.・Uses only water and does not require shot materials (metal balls, abrasive grains, sand...).・Maintains the toughness of the material and makes the structure fine and dense.・The dimples formed on the surface improve sliding and lubricity.・No need to wash after processing.・Grinding burn is suppressed.・The hardened surface layer does not peel off.・Expensive plunger pump is unnecessary. You can get various benefits such as

As described above, the present invention relates to the grinding and polishing of machine tools, particularly to the grinding technology of grinding machines. In particular, due to the decay erosion effect (cavitation peening effect) possessed by microbubbles, a completely new method and apparatus for constantly regenerating the grinding surface of a rubber grindstone or grinding wheel by the jetting action of microbubbles, and the surface grinding layer of the work material. We can provide groundbreaking new technologies such as grinding equipment for grinding and polishing, cavitation injection nozzles for grinding wheels, and automatic grinding operation methods.

The present invention is not limited to the embodiments described above, but is a new technology that can be extended to a wide variety of other grinding and polishing techniques, as well as to a wide variety of other applications.

1 Coolant liquid 1a Fine bubble 2 Tank 3 Filtration filter 4 Regulator 5 Plunger valve 6 Drain 8 Accumulator 9 Piping 10 Grinding machine 11 Grinding wheel 11a Grinding surface 50 NC control device 100 Cavitation generator BL Blade GT, BT Rubber wheel and hard Grinding wheel G Abrasive grain S Bonding agent SP Rotating shaft E Pores F Compression grinding force K Bubble collapse N Cavitation nozzles n1, n2 Nozzle P Suction pump M Motor Y Work material Y1 Surface W1 Ultra high pressure water W2 Low pressure water

Claims (11)

A grinding surface regeneration method for a grinding wheel surface by a cleaning action that occurs when microbubbles produced by a cavitation generator are sprayed onto the grinding surface of a grinding wheel on a grinding machine, comprising:
The cavitation injection nozzle that injects the fine bubbles is characterized by ejecting the fine bubbles toward the outer peripheral surface of the grinding wheel, thereby removing the grinding dust on the surface layer of the grinding wheel and exposing and regenerating the abrasive grains on the grinding surface. A method for constantly regenerating the grinding surface of a grinding wheel by the jetting action of microbubbles. A method for constantly regenerating a grinding surface of a grinding wheel by the jet action of microbubbles according to claim 1,
When the grinding wheel is a rubber wheel, the microbubbles injected from the cavitation injection nozzle to the outer peripheral surface of the rubber wheel remove the thermosetting resin or rubber, which is the binding agent of the rubber wheel with a smooth surface, using a peeling function. A method for constantly regenerating a grinding surface of a rubber grindstone by the jet action of microbubbles, characterized by exposing grains on the grindstone surface to regenerate a new satin-like surface on the rubber grindstone. In the method for constantly regenerating and molding a grinding surface of a rubber grindstone or a grinding wheel by the jetting action of microbubbles according to claims 1 and 2 above, the microbubbles generated by the cavitation generator pass through an accumulator in the cavitation generator. When the pressure is continuous and uniform, the cavitation injection nozzle is ejected, and when the accumulator is not interposed, the injection is pulsating, fluctuating, and uneven. Grinding surface regeneration method. In the method for constantly regenerating and molding a grinding surface of a rubber whetstone and a grinding whetstone by the injection action of microbubbles according to claim 3, the water pressure and water volume of the microbubbles generated by the cavitation generator, the on/off of the pulsating jet, and the microbubbles. A constant grinding surface regenerating device for rubber whetstones and grinding whetstones, characterized in that the size setting and other functions of the cavitation generator are controlled by commands from an NC control device. A grinding apparatus for improving properties of a surface grinding layer of a material to be ground by injecting microbubbles produced by a cavitation generator onto a grinding surface of a material to be ground and polished by a rubber whetstone or a grinding wheel, the grinding apparatus comprising: The cavitation injection nozzles for injecting fine bubbles are arranged to inject fine bubbles toward the outer peripheral surface of the rubber whetstone or grinding wheel and the grinding surface where the outer peripheral surface of the rubber whetstone or grinding whetstone is in contact with the material to be ground, The fine bubbles are sprayed onto the outer peripheral surface of the grinding wheel and the grinding surface in contact with the material to be ground, and the abrasive grains are exposed when the outer peripheral surface of the rubber grindstone or grinding wheel is sprayed, while the fine bubbles are sprayed onto the surface grinding layer of the material to be ground. Squeeze the microbubbles of the rubber grindstone or grinding wheel and promote collapse and corrosion by grinding force, generate shock wave and impact force when the bubbles collapse, aim for surface modification such as shot peening, and improve the inner layer of the rubber grindstone or grinding. Grinding and polishing to improve the properties of the surface grinding layer of the work material characterized by exposing and reproducing the abrasive grains of the inner layer of the grindstone on the grinding surface and simultaneously grinding and polishing the machined surface properties of the work material with high precision. grinding equipment. In the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 5, the cavitation injection nozzle injects fine bubbles toward the grinding surface where the outer peripheral surface of the rubber grindstone or grinding wheel contacts the material to be ground. A grinding apparatus for grinding and polishing a surface grinding layer of a work material to improve properties thereof. In the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to the above claims 5 and 6, the microbubbles generated by the cavitation generator are continuous when intervening the accumulator in the cavitation generator. Grinding and polishing to improve the properties of the surface grinding layer of the work material, characterized in that it is discharged from the cavitation injection nozzle at a uniform pressure, and is pulsating, fluctuating, and unevenly injected when no accumulator is interposed. Device. In the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to claim 7, the setting of the water pressure, water volume, on/off of the pulsating jet, and the size of the microbubbles, which are the settings of the cavitation generator, are 1. A grinding device for grinding and polishing a surface grinding layer of a work material to improve properties, wherein the grinding is performed by a command signal from an NC control device that controls the function setting of the cavitation generator. In the method and apparatus for constantly regenerating a grinding surface of a rubber whetstone or a grinding whetstone according to claims 1 to 4, the cavitation injection nozzle consists of an inner and outer double cylinder, and ultrahigh-pressure water is supplied to the central cylinder. , low-pressure water is supplied to the space of the outer peripheral annular cylinder, and the jet water jetted from the cavitation jet nozzle has an ultra-high pressure column in the center, and the outer periphery of the ultra-high pressure column is annular. Micro bubbles are present, and the periphery of the micro bubbles is a triple annular jet of low-pressure water, and the ultra-high pressure column in the center is high-pressure washing of grinding dust and peeled adhesive adhered to the outer peripheral surface of the grindstone. A grinding wheel characterized in that the annular fine bubbles expose the abrasive grains on the outer peripheral surface of the grindstone, and the annular low-pressure water around the outer periphery cleans the exposed grinding dust and peeled adhesive material on the outer peripheral surface of the grindstone. Cavitation injection nozzle for. In the grinding apparatus for grinding and polishing the surface grinding layer of the work material according to the above claims 5 and 6, the cavitation injection nozzle is composed of inner and outer double cylinders, and an ultra high pressure is injected into the central cylinder. Water is supplied, and low-pressure water is supplied into the space of the outer circumferential annular cylinder, and the jetted water jetted from the cavitation jet nozzle forms an ultrahigh-pressure column in the center and outside the ultrahigh-pressure column. The periphery presents annular microbubbles, the outer periphery of the microbubbles is a triple annular jet of low-pressure water, and the ultra-high pressure column in the center is grinding dust adhering to the outer peripheral surface of the grindstone and peeled adhesive. The ring microbubbles expose the abrasive grains on the outer peripheral surface of the grindstone, and the ringed low-pressure water on the outer periphery cleans the exposed grinding dust and peeled adhesive on the outer peripheral surface of the grindstone. Cavitation injection nozzle for grinding wheels. The NC control device that governs the grinding control in the above claims 4 and 8 includes selection of a grinding wheel for the material to be ground, selection of fine bubbles, detection of the surface state of the grinding surface and the material to be ground during grinding, and Image detection of the surface shape of the grinding wheel surface and the material to be ground, comprehensive judgment of the surface shape of the grinding wheel surface and the material to be ground after grinding, and feedback to the grinding wheel selection process for the defective material to be ground again. An automatic grinding operation method characterized by repeating

Images