Caulking apparatus

Abstract

During a caulking process, a pressure is applied to a pressure receiving shoulder portion in the same direction as a direction of a clamping force generated by a caulking portion. The clamping force for holding an outer race can thereby be increased. Also, a pressure receiving surface of the pressure receiving shoulder portion is set higher than an end face. Thus, no pressure resulting from plastic deformation in a direction perpendicular to the direction of the clamping force of the caulking portion is generated. In addition, a groove is formed between the pressure receiving shoulder portion and an end serving as the caulking portion.

What is claimed is: 
     
         1 . A caulking apparatus that bends an end of a workpiece along a corner portion of a member by a caulking surface of a caulking roller, applies a pressure to a pressure receiving shoulder portion, which is formed opposite a bent side of the end, in a same direction as a caulking pressure applied to the caulking surface to thereby carry out a caulking process and hence form a caulked portion, and carries out a caulking process of holding the held member along a base of the workpiece by a clamping force of the caulked portion, the caulking apparatus comprising:
 a workpiece mount;   a rolling pressurization unit that presses the workpiece arranged on the workpiece mount as the caulking roller is rolled over the workpiece;   a caulking process load state detection unit that detects a caulking process load applied by the caulking roller;   a specific change detection unit that detects a specific change in the caulking process load detected by the caulking process load state detection unit that indicates the member begins to be strained; and   a caulking process changing unit that changes a caulking process for the workpiece based on a timing at which the specific change detection unit detects the specific change.   
     
     
         2 . The caulking apparatus according to  claim 1 , wherein the caulking process changing unit starts a caulking termination process to change the caulking process. 
     
     
         3 . The caulking apparatus according to  claim 1 , wherein the caulking process load state detection unit detects a change in a caulking load with respect to a moving distance of the caulking roller as a caulking process load created by the caulking roller. 
     
     
         4 . The caulking apparatus according to  claim 3 , wherein the specific change detection unit detects a state of an abrupt increase in the caulking load as a state of an occurrence of a specific change indicating that the member begins to be strained. 
     
     
         5 . The caulking apparatus according to  claim 1 , wherein the caulking process load state detection unit detects a change in a caulking torque with respect to a moving distance of the caulking roller as a caulking process load created by the caulking roller. 
     
     
         6 . The caulking apparatus according to  claim 5 , wherein the specific change detection unit detects an abrupt decrease in the caulking torque as a specific change indicating that the member begins to be strained. 
     
     
         7 . The caulking apparatus according to  claim 1 , wherein:
 the member is a bearing; and   the workpiece is a housing that accommodates a rotary member rotatably supported by the bearing, or a bearing holder arranged in the housing.   
     
     
         8 . The caulking apparatus according to  claim 7 , further comprising:
 a rotation-translation conversion actuator, wherein:   the bearing and the housing or the bearing holder are a bearing and a housing or a bearing holder of the rotation-translation conversion actuator respectively;   the housing is mounted on a driven object device; and   the rotation-translation conversion actuator includes an output shaft, which moves in an axial direction of the workpiece through rotation of the rotary member, and protrudes outward from the housing to transmit a driving force from the output shaft to the driven object device.   
     
     
         9 . The caulking apparatus according to  claim 8 , wherein:
 the rotary member is a nut of a planetary differential screw type rotation-translation converter;   the output shaft is a sun shaft;   a planetary shaft is arranged between the nut and the sun shaft; and   the sun shaft and the planetary shaft mesh with the nut in a manner to perform rotation-translation conversion.   
     
     
         10 . The caulking apparatus according to  claim 8 , wherein the driven object device is an internal combustion engine.