Method for manufacturing universal joint using pipe

Abstract

The present invention relates to a method for manufacturing a universal joint using a pipe. The shaft joint of the universal joint is manufactured by: a material preparation step of preparing a material by cutting a pipe to a predetermined length; a shaft formation step of forming a shaft by reducing the outer diameter of a shaft formation portion by forming the outside of the shaft formation portion with a forming machine; a cutting step of bisecting the non-reduced head formation portion by forming a split across the non-reduced head formation portion in an axial direction; a yoke formation step of forming both opposite members of a yoke in a head by pressing the bisected head formation portion; a pinhole formation step of forming a pinhole across the yoke; and a spline shaft formation step of forming a spline shaft on the outer surface of the reduced hollow shaft.

1 . A method for manufacturing a universal joint using a pipe, the universal joint ( 1 ) comprising a combination of a shaft joint ( 2 ) and a pipe joint ( 3 ) integrated with yokes ( 25  and  35 ), respectively;
 the shaft joint ( 2 ) being manufactured by: 
 a material preparation step (S 11 ) of preparing a material (B) by cutting a pipe (A) to a predetermined length; 
 a shaft formation step (S 12 ) of forming a shaft ( 23 ) by reducing an outer diameter of a shaft formation portion ( 22 ), obtained by excluding a head formation portion ( 21 ) from the material (B), by forming an outside of the shaft formation portion ( 22 ) with a forming machine; 
 a cutting step (S 13 ) of bisecting the non-reduced head formation portion ( 21 ) by forming a split ( 24 ) across the non-reduced head formation portion ( 21 ) in an axial direction; 
 a yoke formation step (S 14 ) of forming both opposite members of a yoke ( 25 ) in a head by pressing the bisected head formation portion ( 21 ); 
 a pinhole formation step (S 15 ) of forming a pinhole ( 26 ) across the yoke ( 25 ); and 
 a spline shaft formation step (S 16 ) of forming a spline shaft ( 27 ) on an outer surface of the reduced hollow shaft ( 23 ). 
 
     
     
         2 . A method for manufacturing a universal joint using a pipe, the universal joint ( 1 ) comprising a combination of a shaft joint ( 2 ) and a pipe joint ( 3 ) integrated with yokes ( 25  and  35 ), respectively;
 the shaft joint ( 2 ) being manufactured by: 
 a material preparation step (S 111 ) of preparing a material (B) by cutting a pipe (A) to a predetermined length; 
 a shaft formation step (S 112 ) of forming a shaft ( 23 ) by reducing an outer diameter of a shaft formation portion ( 22 ), obtained by excluding a head formation portion ( 21 ) from the material (B), by forming an outside of the shaft formation portion ( 22 ) with a forming machine; 
 a preliminary yoke formation step (S 113 ) of forming a preliminary yoke by means of a pressing method (rolling) of introducing the non-reduced head formation portion ( 21 ) into a die and then pressing an upper press die into an inside of the head formation portion ( 21 ); 
 a cutting step (S 114 ) for formation of a yoke of cutting away connection portions, other than the yoke, from a rectangular shape with an open top, which is formed by the preliminary yoke formation step; 
 a pinhole formation step (S 115 ) of forming a pinhole ( 26 ) across the yoke ( 25 ); and 
 a spline shaft formation step (S 116 ) of forming a spline shaft ( 27 ) on an outer surface of the reduced hollow shaft ( 23 ). 
 
     
     
         3 . A method for manufacturing a universal joint using a pipe, the universal joint ( 1 ) comprising a combination of a shaft joint ( 2 ) and a pipe joint ( 3 ) integrated with yokes ( 25 ), respectively;
 the pipe joint ( 3 ) being manufactured by:   a material preparation step (S 21 ) of preparing a material (B) by cutting a pipe (A) to a predetermined length;   a tube formation step (S 22 ) of reducing an outer diameter of a tube formation portion ( 32 ), obtained by excluding a head formation portion ( 31 ) from the material (B), by forming an outside of the tube formation portion ( 32 ) with a forming machine;   a cutting step (S 23 ) of bisecting the non-reduced head formation portion ( 31 ) by forming a split ( 34 ) across the non-reduced head formation portion ( 31 ) in an axial direction;   a yoke formation step (S 24 ) of forming both opposite members of a yoke ( 35 ) in a head by pressing the bisected head formation portion ( 31 );   a pinhole formation step (S 26 ) of forming a pinhole ( 36 ) across the yoke ( 35 ); and   a spline boss formation step (S 27 ) of forming a spline boss ( 37 ) on an inner surface of the reduced hollow tube ( 33 ).   
     
     
         4 . A method for manufacturing a universal joint using a pipe, the universal joint ( 1 ) comprising a combination of a shaft joint ( 2 ) and a pipe joint ( 3 ) integrated with yokes ( 25 ), respectively;
 the pipe joint ( 3 ) being manufactured by:   a material preparation step (S 211 ) of preparing a material (B) by cutting a pipe (A) to a predetermined length;   a tube formation step (S 212 ) of reducing an outer diameter of a tube formation portion ( 32 ), obtained by excluding a head formation portion ( 31 ) from the material (B), by forming an outside of the tube formation portion ( 32 ) with a forming machine;   a preliminary yoke formation step (S 213 ) of forming a preliminary yoke by means of a pressing method (rolling) of introducing the non-reduced head formation portion ( 31 ) into a die and then pressing an upper press die into an inside of the head formation portion ( 31 );   a cutting step (S 214 ) for formation of a yoke of cutting away connection portions, other than the yoke, from a rectangular shape with an open top, which is formed by the preliminary yoke formation step;   a pinhole formation step (S 215 ) of forming a pinhole ( 36 ) across the yoke ( 35 ); and   a spline boss formation step (S 216 ) of forming a spline boss ( 37 ) on an inner surface of the reduced hollow tube ( 33 ).   
     
     
         5 . The method of  claim 1 , wherein the pipe (A) prepared at each of the material preparation steps (S 11 , S 111 , S 21 , and S 211 ) is a seamless pipe without a seam. 
     
     
         6 . The method of  claim 2 , wherein the pipe (A) prepared at each of the material preparation steps (S 11 , S 111 , S 21 , and S 211 ) is a seamless pipe without a seam. 
     
     
         7 . The method of  claim 3 , wherein the pipe (A) prepared at each of the material preparation steps (S 11 , S 111 , S 21 , and S 211 ) is a seamless pipe without a seam. 
     
     
         8 . The method of  claim 4 , wherein the pipe (A) prepared at each of the material preparation steps (S 11 , S 111 , S 21 , and S 211 ) is a seamless pipe without a seam.