. Automotive industries . hin webs and flat flanges, it is not practicable to forgethem thus. On forgings draft is necessary both on theoutside and the inside of the flanges, and the thicknessof metal cannot be reduced be-yond the point at which the -0metal will readily flow to the re-quired depth in the die. It is,however, both possible and prac-ticable to improve considerablyon the present average designand for a given strength increasethe .efficiency as denned belowfrom 5 to 10 per cent. The usual draft angle forforged axle sections is 10 deg.,this angle being advocated bythe forge shops as
. Automotive industries . hin webs and flat flanges, it is not practicable to forgethem thus. On forgings draft is necessary both on theoutside and the inside of the flanges, and the thicknessof metal cannot be reduced be-yond the point at which the -0metal will readily flow to the re-quired depth in the die. It is,however, both possible and prac-ticable to improve considerablyon the present average designand for a given strength increasethe .efficiency as denned belowfrom 5 to 10 per cent. The usual draft angle forforged axle sections is 10 deg.,this angle being advocated bythe forge shops as best adaptedto quantity production, as it ob-viates sticking in the dies dueto the contraction of the forgingin the die-block. Since the con-traction of the forging in cool-ing is responsible for this diffi-culty, it is apparent that the in-side faces of the flanges are thesurfaces that tend to grip thedie-block, while the outside facestend to draw away from thedie. It seems, therefore, that areduction of the draft angle. Figs 1, 2, 3 and 4—Axle sections with variousangles of draft. Fig. 5—Changing the axle sec-tion shown, in heavy lines to conform to dottedlines decreased axle weight 6% lb. without mate-rial decrease in strength on the outside of the flange would not only be practicablefrom the forging standpoint but would result in a moreadvantageous disposition of the metal of the taking this matter up with the forge shops it wasfound that 7 deg. was a perfectly practicable draft anglefor the outside of the flange and even 5 deg. could beused without difficulty. Figs. 1, 2, and 3 show axle sections having outsidedraft angles of 10, 7 and 5 deg. respectively, while Fig. 4represents an ideal condition with no outside Fig. 4 as an arbitrary standard for comparisonand calling it 100 per cent, the efficiencies of Figs. 1,2 and 3 are per cent, per cent and percent respectively, these efficiency values being basedon the ratio of the rad
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectaeronautics, bookyear
