Abstract: An object of the present invention is to provide a punching method using a punch, which makes it possible to effectively improve the durability of a tooth portion of the punch. In a punching method using a punch for forming a through-hole in a workpiece by punching the workpiece using a punch, at least a tooth portion of the punch is made substantially solid when the workpiece is punched by the punch, and the tooth portion is made substantially hollow, thereby a diameter of the tooth portion is reduced by a reaction force received from the workpiece, when the workpiece is separated from the punch after the punching of the workpiece.

Abstract: The present invention provides a production apparatus for crankshaft, including: a die which has a lower die, an upper die, and plural side forming punches, the upper die being provided movably to the lower die, the side forming punches moving perpendicularly to a movement direction of the upper die; a press ram which moves the upper die to the lower die, closes a material of the crankshaft, and forms the material; cam mechanisms which are provided for the side forming punches and which move the side forming punches to an inside portion of the die in accordance with movement of the press ram; a grade separation structure which is provided to at least one of the side forming punches in order to prevent interference of the side forming punches with each other.

Abstract: The present invention provides a production apparatus for crankshaft, including: a die which has a lower die, an upper die, and plural side forming punches, the upper die being provided movably to the lower die, the side forming punches moving perpendicularly to a movement direction of the upper die; a press ram which moves the upper die to the lower die, closes a material of the crankshaft, and forms the material; cam mechanisms which are provided for the side forming punches and which move the side forming punches to an inside portion of the die in accordance with movement of the press ram; a grade separation structure which is provided to at least one of the side forming punches in order to prevent interference of the side forming punches with each other.

Abstract: An object of the present invention is to provide a punching method using a punch, which makes it possible to effectively improve the durability of a tooth portion of the punch. In a punching method using a punch for forming a through-hole in a workpiece by punching the workpiece using a punch, at least a tooth portion of the punch is made substantially solid when the workpiece is punched by the punch, and the tooth portion is made substantially hollow, thereby a diameter of the tooth portion is reduced by a reaction force received from the workpiece, when the workpiece is separated from the punch after the punching of the workpiece.

Abstract: A machining program transmission system 1 has a control device of an NC machine tool 10, a transmission device 20 and a terminal device 40 are connected via an electrical communication line 2. The terminal device 40 reads an identification information 31 of a machining program, the identification information being attached to a medium 32. The terminal device 40 also reads an identification information 18 of the NC machine tool 10, the identification information being attached to the NC machine tool 10 for carrying out the machining. The terminal device 40 transmits the information to the transmission device 20. The transmission device 20 transmits the machining program corresponding to the program identification information 31 to the NC machine tool 10 corresponding to the machine identification information 18. The control device of the NC machine tool 10 receives and stores the machining program.

Abstract: A machining program transmission system 1 has a control device of an NC machine tool 10, a transmission device 20 and a terminal device 40 are connected via an electrical communication line 2. The terminal device 40 reads an identification information 31 of a machining program, the identification information being attached to a medium 32. The terminal device 40 also reads an identification information 18 of the NC machine tool 10, the identification information being attached to the NC machine tool 10 for carrying out the machining. The terminal device 40 transmits the information to the transmission device 20. The transmission device 20 transmits the machining program corresponding to the program identification information 31 to the NC machine tool 10 corresponding to the machine identification information 18. The control device of the NC machine tool 10 receives and stores the machining program.

Abstract: An upset forging die device and method are provided for upset-forging a raw material that is being filled in a cavity of a lower molding die at a portion between an upper punch of an upper molding die provided on a slide and a lower punch of the lower molding die provided on a bolster. The upper and lower punches are provided with an upper pin and a lower pin respectively so that a first end of each pin is protruded and withdrawn from each of end surfaces of the upper and lower punches and the pins are vertically movable in the upper and lower punches respectively, while a second end of the upper and lower pins is applied with a back-pressure.

Abstract: A method for producing a bevel gear shaft, adaptable to produce a shaft having a desired recess shape, such as an involute spline, in the longitudinal direction. A blank, having a bevel gear portion complementary to an upper die and a shaft portion small enough to fit into a lower die, is utilized in the process. The product is formed to the shape of upper and lower dies held together in a press. An upper punch passes downward through the upper die and a lower punch passes upward through the lower die. The punches displace some of the raw material of the blank forcing it to bulge and take on the shape of the upper and lower dies. The bevel gear portion may be coined by the upper die simultaneously with the forging of the bevel gear shaft. The invention shortens production time, increases product strength, and improves product yield per unit weight of raw material.