Roller-dies-processing method and apparatus

A method for manufacturing taper bars desiredly tapered at least in two directions by drawing using a roller dies apparatus comprising at least two succesively arranged sets of idler rollers in different phase angle, each of said roller sets comprising a plurality of mutually approachable and departable rollers which are provided with a respective circumferential groove having a constant sectional figure and a constant dimension through all the length thereof, said method comprising the following steps:

• (a) pulling a blank through the roller sets at a temperature not exceeding 800.degree. C.;
• (b) measuring the travelling amount in the longitudinal direction of the taper bar;
• (c) generating by a controller based on the measured travelling amount and a taper value pre-set, signals respectively representing target distance of each of said rollers from a predetermined level line;
• (d) measuring the actual distance of each roller from the level line;
• (e) comparing the target distance and the actual distance and adjusting the position of each roller so that the actual distance is equal to the target distance and all passes formed by said at least two sets of idler rollers are gradually changed in size in an interrelated manner to each other commonly based on the measured travelling amount;
• (f) measuring the sectional dimension of the taper bar on the outlet side of the last set of the roller sets;
• (g) feeding back the measured sectional dimension to the controller for rectifying the target distance of each of the rollers;
• (h) the measuring of the travelling amount, the generation of the output signals representing the target distances, the measuring of the actual distances, the adjustments of the roller positions, the measuring of the sectional dimension and the rectifying the target distances being performed while drawing is in progress;
• and
• (i) the adjusting of the rollers of the plural roller sets being performed so that the passing line of the blank is maintained constant.

An apparatus for drawing a deformable blank along a pass line to a taper bar with desired tapers at least in two directions comprising:

• (a) multi-tandem type roller dies means including at least two sets of roller dies successively arranged along the pass line in different phase angle, each set of said roller dies including:
• a plurality of idler rollers rotatable about axes arranged in a plane perpendicular to the pass line and relatively movable toward and away from each other, each of said idler rollers having circumferential groove in the periphery thereof with a constant cross-sectional configuration and dimension throughout the whole length thereof to form a size changeable pass among respective set of said idler rollers, and
• roller adjusting means for changing position of each of said idler rollers;
• (b) drawing means for pulling the deformable blank through the passes of said roller dies means;
• (c) travelling amount measuring means disposed on the outlet side of the last set of said roller dies for measuring the travelling amount of said taper bar;
• (d) controlling means including at least two lines of controlling systems commonly connected to said travelling amount measuring means for respectively controlling each set of said roller dies, each line of said controlling system including:
• a controller connected to said travelling amount measuring means and outputing electric signal indicating a target distance from a predetermined level line to each of said rollers, based on the measured travelling amount and a preset taper value,
• roller position sensing means for sensing a distance from said predetermined level line to each of said rollers, and
• servo means for comparing the actually measured distance by said roller position sensing means and the target distance output from said controller for designating said roller adjusting means so as to make the difference between said measured distance and said target distance equal to zero.

An apparatus for drawing a deformable blank along a pass line to a taper bar with desired tapers at least in two directions comprising:

• (a) a frame;
• (b) two sets of roller dies successively arranged in the travelling direction of said deformable blank with phase angle difference of 90.degree., each set of said roller dies including:
• a pair of hydraulic cylinders fixed to said frame in such a manner that two piston rods of said pair of hydraulic cylinders are coaxally faced to each other,
• a pair of idler rollers respectively mounted on each of a pair of shafts which are supported by two pairs of chocks and forming a size changeable pass by a respective circumferential groove formed on each of said pair of idler rollers, and
• a pair of biasing cylinders disposed between said two pairs of chocks for biasing each of said two pairs of chocks toward each of said two piston rods;
• (c) drawing means for pulling the deformable blank through the passes of said roller dies means;
• (d) travelling amount measuring means disposed on the outlet side of the last set of said roller dies for measuring the travelling amount of said taper bar;
• (e) controlling means including at least two lines of controlling systems commonly connected to said travelling amount measuring means for respectively controlling each set of said roller dies, each line of said controlling systems comprising;
• a controller connected to said travelling amount measuring means for outputing electric signal indicating a target distance from a predetermined level line to each of said rollers, based on the measured travelling amount and a preset taper value,
• roller position sensing means for sensing a distance from said predetermined level line to each of said rollers, and
• servo means for comparing the actually measured distance by said roller position sensing means and the target distance output from said controller and for supplying pressurized liquid to each of said hydraulic cylinders so as to make the difference between said measured distance and said target distance equal to zero.