Fly Tool Research Articles

Measurement of cutting force and cutting temperature on gear cutting in fly tool for clarification of dry hobbing phenomenon

Measurement of cutting force and cutting temperature on gear cutting in fly tool for clarification of dry hobbing phenomenon

Influence of Water-Miscible Cutting Fluids on Tool Wear Behavior of Different Coated HSS Tools in Hobbing

The present paper describes the influence of water-miscible cutting fluids on tool life (flank wear) and crater wear of various coated cutting tools and finished surface roughness, as compared with the cases of dry cutting and wet cutting using cutting oil in hobbing in an attempt to improve the working environment. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The following results were obtained. (1) In the case of an uncoated tool, cutting oil was more effective than dry cutting in reducing flank wear. Cutting oil and water-miscible cutting fluids were more effective in reducing flank wear than dry cutting using TiN- and TiAlN-coated tools. The use of water-miscible cutting fluids in conjunction with TiSiN- and AlCrSiN-coated tools prolongs tool life. (2) For all coated tools, the use of cutting oil or water-miscible cutting fluids were effective in reducing crater wear. Especially, water-miscible cutting fluids were effective for TiSiN- and AlCrSiN-coated tools. (3) Regarding the finished surface roughness, in the case of dry cutting, the finished surface roughness was similar for various types of coating films. When using cutting oil or a water-miscible cutting fluid, the finished surface roughness improved compared with dry cutting, independent of the type of coating film applied. The finished surface roughness obtained using water-miscible cutting fluid was approximately the same as or smaller than that obtained using cutting oil. (4) With respect to flank wear, crater wear, and finished surface roughness, the water-miscible cutting fluid of emulsion type containing a large amount of synthetic lubricating additives was suitable for the AlCrSiN-coated tool.

Fundamental Research on Hobbing and Finish-Hobbing in Dry and with MQL System

This paper deals with hobbing and finish-hobbing that considers the machine environment when using various hard hob materials. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results are summarized as follows. (1) Under the condition of hobbing with TiN-coated tools in dry cutting and with a minimal quantity of lubricant (MQL) system, P20 and P30 hob materials as the substrate show stable cutting and do not cause tool failure. The flank wear obtained with P30 is less than that obtained with P10 and P20 in the case of the coated TiAlN film tool. The MQL system shows flank wear reduction compared with dry cutting. (2) Under the condition of finish-hobbing, when using the TiN-coated tool, the flank wear obtained with dry cutting is smaller than that obtained with the MQL system. The flank wear increases in the order of P10, P20 and P30 hob materials, and the P10 hob material is effective. The TiAlN-coated P30 tool decreases flank wear and is suitable for finish-hobbing in dry cutting and with the MQL system. (3) Under the condition of hobbing, the finished surface roughness obtained with the MQL system when using TiN-and TiAlN-coated tools is smaller than that obtained by dry cutting. (4) Under the condition of finish-hobbing, the finished surface roughness obtained with TiN-and TiAlN-coated P30 is small in dry cutting and with the MQL system.

G1300101 ホブ切り用水溶性切削油剤に関する基礎的研究 : 各種コーティング工具の摩耗挙動に及ぼす影響

This paper deals with the influence of water-soluble cutting fluid on tool life (flank wear) of various coated cutting tools and finished surface roughness compared with dry cutting and water-insoluble cutting oil in hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The following results were clarified. (1) In the conditions of 1-thread and 3-thread hobs, the water-soluble cutting fluid used in the tests prolongs the tool life of TiSiN- and AlCrSiN-coated tools compared with that obtained with dry cutting and the water-insoluble cutting oil. (2) The water-soluble cutting fluid used in the tests is effective for all of various coated tools in the term of finished surface roughness. (3) From the viewpoints of tool life and finished surface roughness, the water-soluble cutting fluid is suitable for TiSiN- and AlCrSiN-coated tools.

環境に配慮したホブ切りの基礎的研究（コーティング被膜の影響）

This paper presents tool life (flank wear) and crater wear of four kinds of coated high-speed steel tools and finished surface roughness in hobbing under the conditions of considering environment. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. As a consequence, the following results were obtained. (1) Under the condition of 1-thread hob, TiN- and AlCrSiN-coated tools showed the longest tool life among the four kinds of coated tools in dry and with MQL system. Under the condition of 3-thread hob, TiSiN-coated tool is effective in dry, and TiAlN- and AlCrSiN-coated tools are suitable with MQL system. (2) The crater wear of TiN-coated tool is smallest in other coated tools tested both in dry and with MQL system under the condition of 1-thread hob. TiAlN-, TiSiN- and AlCrSiN-coated tools are effective, and it was suggested that the crater wear is protected by the deposited metal under the condition of 3-thread hob. (3) The finished surface roughness, which was obtained with almost of coated tools tested at the end of cutting with MQL system both under the conditions of 1- and 3-thead hobs, is smaller than that obtained by dry. (4) From the viewpoints of tool life, crater wear and finished surface roughness, AlCrSiN-coated tool is suitable for hobbing with MQL system.

A35 環境に配慮したホブ切りの基礎的研究 : コーティング被膜の影響(OS13 環境適応型加工(1))

This paper deals with the influence of various coating films of high-speed steel tool on tool life (flank wear) in hobbing with dry cutting and minimal quantity lubrication (MQL) system when changing the hob feed. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results are summarized as follows. (1) In the case of hob feed of 1.5 mm/rev, TiN-coated tool is effective for dry cutting and AlCrSiN-coated tool is effective for MQL system. (2) With 4.0 mm/rev, TiSiN-coated tool is suitable for dry cutting and TiAlN and AlCrSiN-coated tools are suitable for MQL system. Especially, an AlCrSiN-coated tool showed the tool life obtained with MQL system more than twelve times compared with dry cutting.

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil Influence of Hardness of Work Materials Under Several Cutting Conditions

This paper deals with the influence of hardness of work materials on flank wear, crater wear and finished surface roughness when using two types of high-speed steel (HSS) hob tool materials coated with (Al,Ti)N film. Specifically, hobbing with a minimal quantity lubrication (MQL) system is compared with dry hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results are summarized as follows. (1) With SCM415 work material changed to hardness HB131, HB144 and HB161 by heat treatment, flank wear and crater wear of the tool are small when cutting comparatively hard HB161 work material, irrespective of the change in hob materials and cutting speeds. (2) With SCM435 work material changed to hardness HB172, HB195 and HB214, flank wear and crater wear tend to be small when cutting annealed HB172 work material. (3) When cutting SCM415 of hardness HB161 and SCM435 of hardness HB172, the finished surface roughness is small and the surface roughness of SCM415 is smaller than that of SCM435. (4) SCM415 of hardness HB161 is suitable for an MQL system in hobbing in terms of flank wear, crater wear and finished surface roughness.

Influence of Dimensions of Chip on Roughness of Finished Surface Produced by Hobbing (Fundamental Experiments Using Fly Tool)

Influence of Dimensions of Chip on Roughness of Finished Surface Produced by Hobbing (Fundamental Experiments Using Fly Tool)

Water Harvesting Structure Positioning by Using Geo-Visualization Concept and Prioritization of Mini-Watersheds Through Morphometric Analysis in the Lower Tapi Basin

Geo-visualization concept has been used for positioning water harvesting structures in Varekhadi watershed consisting of 26 mini watersheds, falling in Lower Tapi Basin (LTB), Surat district, Gujarat state. For prioritization of the mini watersheds, morphometric analysis was utilized by using the linear parameters such as bifurcation ratio (Rb), drainage density (Dd), stream frequency (Fu), texture ratio (T), length of overland flow (Lo) and the shape parameter such as form factor (Rf), shape factor (Bs), elongation ratio (Re), compactness constant (Cc) and circularity ratio (Rc). The different prioritization ranks were assigned after evaluation of the compound factor. 3 Dimensional (3D) Elevation Model (DEM) from Shuttle Radar Topography Mission (SRTM) and DEM from topo contour were analyzed in ArcScene 9.1 and the fly tool was utilized for the Geo-visualization of Varekhadi mini watersheds as per the priority ranks. Combining this with soil map and slope map, the best feasibility of positioning check dams in mini-watershed no. 1, 5 and 24 has been proposed, after validation of the sites.

ＭＱＬによるホブ切りにおける超硬合金ホブ材種の影響―すくい面にコーティングがない場合の舞いツールによる基礎実験―

This paper deals with the influence of various cemented carbide hob materials coated with TiN and (Ti,Al)N films, which are no coating on the rake face by grinding, on flank wear (tool life), crater wear and finished surface roughness in hobbing with minimal quantity lubrication (MQL) system compared with dry cutting. Experiments were carried out by simulating hobbing by fly tool cutting on a milling machine. As a consequence, the following results were obtained. (1) The tool failures do not occur with the TiN-coated P20 and P30 hob materials both in dry cutting and with MQL system, which showed the stable cutting. The flank wear obtained with the P30 is smaller than that with the P20, and the P30 also showed a good performance in the case ofthe coated (Ti,Al)N film. The MQL system showed the flank wear reduction effect compared with dry cutting. (2) The crater wear reduction effect by MQL system was recognized, and moreover the MQL system decreases the occurrence of the thermal cracks on the rake face. (3) The MQL system improves the surface roughness, even if the kinds of cemented carbide hob materials and the coating films were changed. (4) From the viewpoints of the flank wear, the crater wear and the finished surface roughness, the MQL system is effective for the cutting tool of (Ti,Al)N-coated P30, as a hob material.

Influence of Kinds of Cemented Carbide Hob Materials in Hobbing with MQL System

This paper investigates the influence of kinds of cemented carbide hob materials coated with fully TiN and (Ti, Al)N coatings, in hobbing with minimal quantity lubrication (MQL) system compared with dry cutting in cutting performance, in terms of flank wear (tool life), crater wear and finished surface roughness. Experiments were carried out by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When changing the kinds of hob materials, P10, P20 and P30, as a substrate, the P30 hob material showed a longest tool life, even if the kinds of coating films were changed. The tool life obtained with the Fully (Ti, Al)N-coated tools is longer than that obtained with TiN-coated tools. The flank wear reduction effect by MQL system, which prolongs the tool life compared with the dry cutting, was recognized. (2) Although the reduction effect was recognized in the crater wear, the thermal cracks occur on the rake face of both fully TiN-and (Ti, Al)N-coated P30 tools. (3) The MQL system decreases the surface roughness with all of the cemented carbide hob materials and the coating films tested. (4) From the viewpoints of the tool life, the crater wear and the surface roughness, the use of MQL system for the fully (Ti, Al)N-coated P30 tool is effective.

Influence of Concentration of Sulfurous and Phospherous EP Additives in Cutting Oil in Hobbing with MQL System

In this paper, the influence of concentration of sulfurous and phosphorous EP additives added on flank wear, crater wear of TiN- and (Al, Ti) N-coated tools, and finished surface roughness were investigated with minimal quantity lubrication (MQL) system in hobbing. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results helped clarify the following points; (1) In the cases of polysulfide and sulfurized fatty oil, the flank wear decreased in the concentration of additive of 1.0 % (by weight), which showed a optimum concentration. In the case of tricresyl phosphate (TCP), the flank wear decreased with an increase in the concentration. Sulfurized fatty oil showed better wear reduction effect than any other additives. (2) When increasing in the concentration of the additives used in the tests, the crater wear becomes large, which was suggested to be caused by corrosion of additives. (3) Finished surface roughness obtained with EP additives tested is smaller than that obtained with no additive oil. (4) From the viewpoints of flank wear, crater wear and finished surface roughness, sulfurized fatty oil, of which the concentration is 1.0 %, is suitable for MQL system using (Al, Ti) N-coated tool in hobbing.

Geometrical aspects of double enveloping worm gear drive

Double enveloping worm gearing is expected to have contact over larger number of teeth and higher load carrying capacity compared to single enveloping worm gearing. In this paper, contact in this gearing is analysed by geometrical simulation of worm gear tooth generation using intersection profiles of different axial sections of worm representing the hob tooth profile with transverse plane of worm gear. The analysis reveals that in the engaging zone a straight line contact always exists in the median plane and intermittent contact exists at the extreme end sections of worm. This has lead to the idea of using two fly cutters positioned at the location identical to the extreme end sections of worm to generate full worm gear tooth thereby eliminating the need for hobs of complex geometry. For a given worm, a mating worm gear is machined in a gear hobbing machine using fly tool in two settings and nature of contact with the worm is checked by a blue test.

Influnece of Viscosity of Base Oil on Wear Behavior of Fully Coated Tool in Hobbing with Minimal Quantity Lubrication System

This paper deals with the influence of viscosity of oil on flank wear, crater wear and finished surface roughness with minimal quantity lubrication (MQL) system, when using an (Al,Ti)N fully coated tool in hobbing. Experiments were carried out using a fly tool. The results obtained are summarized as follows. (1) The flank wear and the crater wear increased with an increase in viscosity of oil in the range from 19.1 mm2/s to 24.2 mm2/s, and since then, they decrease with increasing in the viscosity from 24.2 mm2/s to 47.6 mm2/s. The flank wear obtained with the oil having viscosity of 19.1 mm2/s is smaller than that obtained by dry cutting. (2) All the oils tested decreased finished surface roughness in comparison with dry cutting. (3) From the viewpoints of the primary performance such as tool wear and finished surface roughness, and the secondary performance of the oxidation stability, the oil having low viscosity of 19.1 mm2/s showed the best performance within the range of viscosity of the oil tested.

B16 切りくずの切削過程におけるホブ摩耗の分配 : 舞いツールによる基礎実験(OS-6 切削加工(3))

In this paper, after developing a method to divide the cutting length of a chip into four equal parts, investigation were carried out on the distribution ratio of hob wear when cutting each of the parts. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1)In the cases of dry cutting and MQL system when using TiN-coated tool, the distribution ratio of bob wear is largest at the end part of cutting chip, but in the case of flood, it is standardized at each part of cutting chip. (2) When using (Al,Ti)N-coated tool, the distribution ratio of hob wear obtained with dry cutting and MQL system is greatest at the beginning part of cutting chip, but that obtained with flood is standardized at each part of cutting chip.

B17 ホブ切り用水溶性切削油剤に関する基礎的研究 : pHの影響(OS-6 切削加工(3))

This paper presents the influence of pH of water-soluble cutting fluids with and without synthetic lubricating additive for hobbing; Fluid A and Fluid B, on the flank wear, using TiN- and (Al,Ti)N-coated tools. Experiments were conducted by simulating hobbingby fly tool cutting on a milling machine. The following result was clarified: When using both Fluid A and Fluid B, the flank wear decreases with decreasing pH, in which the FluidAhavingpH 8.0 and the Fluid B having pH 9.0 showed the smallest flank wear width with both TiN- and (Al,Ti)N-coated tools.

311 極微量切削油供給によるボブ切りの基礎的研究 : ドライ切削との切削性能の比較(OS 材料加工・精密加工(その1))

This paper compares the cutting performance of minimal quantity lubrication (MQL) system with dry cutting in terms of flank wear, crater wear and finished surface roughness when using various kinds of cutting tools. Experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results obtained are summarized as follows. (1) When using an uncoated tool, TiN- and (Al, Ti) N-coated tools without coating on the rake face, and fully TiN- and (Al, Ti) N-coated tools, MQL decreases the flank wear, crater wear and finished surface roughness compared with the wear and the roughness by dry cutting, particularly at the high cutting speed of 159 m/min. The reason suggested is the lubricating properties improved even with an extremely small quantity of cutting oil, which reduces the occurrence of deposited metal on the cutting edge. (2) With both the fully TiN- and (Al, Ti) N-coated tools, the MQL system showed better cutting performance in terms of reduced tool wear and reduced finished surface roughness compared with that by dry cutting; in particular, the fully (Al, Ti) N-coated tool is suitable for an MQL system in hobbing.

Fundamental Research on Water-Soluble Cutting Fluids for Hobbing (2nd Report, Cutting Performance of Various Emulsions)

In this paper, the performance of various emulsions in water-soluble cutting fluids for hobbing was investigated with TiN and (Al, Ti) N coated tools, in terms of flank wear, crater wear and finished surface roughness. Experiments were carried out using a fly tool. The results helped clarify the following points ; (1) With both TiN and (Al, Ti) N coated tools, an emulsion containing synthetic lubricating additive is effective for decreasing the flank wear and the crater wear, irrespective of the change in the cutting speed. (2) It was suggested that a polyalkyleneglycols contained in the emulsion has a tool wear reduction effect, and the reason why the decrease of the crater wear when using the emulsion is due to the protective action by the deposited metal on the rake face. (3) There was no difference in the finished surface roughness obtained with the various emulsions even when changing the cutting speed. (4) In the view point of the tool wear and the surface finish, the emulsion containing synthetic lubricating additive is available for the (Al, Ti) N coated tool in hobbing.

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil (Influence of Viscosity Grade of Base Oil)

This paper investigates the influence of viscosity of oil on flank wear, crater wear and finished surface roughness with minimal quantity lubrication (MQL) system, when changing the kinds of coating films of the hob. Experiments were carried out using a fly tool. As a consequence, the following points were clarified : (1) When using the TIN and (Al, Ti) N coated tools, the flank wear and the crater wear increase with an increase of the viscosity of the oil in the range from 19.1 mm2/s to 30.5 mm2/s in the viscosity grade, after that, it decreases with the oil having high viscosity of 47.6 mm2/s. (2) The surface roughness obtained with the low viscosity of the oil is the smallest in all oils tested at the beginning on cutting, and it showed almost the same value as the theoretical roughness at the end of cutting. (3) From the viewpoints of the primary performance such as the flank wear and the crater wear, and the secondary performance of the oxidation stability, the oil having low viscosity of 19.1 mm2/s is suitable for MQL system in hobbing.

Fundamental Research on Hobbing with Minimal Quantity Lubrication of Cutting Oil (Effect of Cutting Speed)

In this paper, we investigate the effect of cutting speed on flank wear, crater wear and finished surface roughness during hobbing using an uncoated tool, and TiN- and (Al, Ti)N- coated tools with a minimal quantity lubrication (MQL) system. The experiments were conducted by simulating hobbing by fly tool cutting on a milling machine. The results helped clarify the following points. (1) With the uncoated tool and the TiN-coated tool, the flank wear increases upon increasing in the cutting speed from 47m/min to 86m/min. Conversely, flank wear decreases at the higher speed of 117m/min. It was impossible to cut at 159m/min owing to the failure of the cutting edge. With the (Al, Ti)N-coated tool, the flank wear showed nearly the same small value, irrespective of cutting speed. (2) The cutting speed also has a large effect on crater wear, particularly for the TiN-and (Al, Ti)N-coated tools. The cutting speed of 117m/min is suitable for decreasing crater wear. (3) The finished surface roughness is small for all the tools used in this test for cutting speeds less than 86m/min, after which it becomes large because of the adhesion of deposited metal at cutting speeds more than 117m/min. When using the TiN- and (Al, Ti)N-coated tools, there is a critical cutting groove length, at which the surface roughness decreases rapidly.