Patent EP-1749636-A1 (EP)
Inventor: KONDO YOICHIRO
IPC: B29C45/33
Filed: 2005-03-29
Abstract: An object of the present invention is to provide a die and a method for manufacturing a core which are capable of manufacturing cores continuously with high accuracy and with high productivity by using simple and low-cost equipment. A pressing machine 10 is an apparatus for manufacturing cores by vulcanization molding. The core includes a ring-shaped supporting member that is formed by a plate-like member, that is disposed inside a pneumatic tire, and that supports the tire by allowing an inner side of a tread portion of the pneumatic tire to be brought into contact with an outer peripheral surface of the supporting member at the time of a deformation of the tire due to a decrease of an internal pressure of the tire, and ring-shaped rubber portions that are respectively joined to both widthwise direction edge portions of the supporting member. The pressing machine 10 includes a ring-shaped core die that is brought into contact with the supporting member 16 from a radial direction inner side thereof while maintaining a non-contact state with the both widthwise direction edge portions of the supporting member 16, and an upper intermediate die 28 and a lower intermediate die 30 that are disposed so as to hold the core die 26 therebetween from the widthwise direction of the core die 26 and form cavities 42A and 42B for forming the rubber portions between the upper intermediate die 28 and the core die 26 as well as between the lower intermediate die 30 and the core die 26. The rubber material G contained in pod portions 46A1 and 46A2 is transferred from runners 44A1 and 44A2 that are formed at the upper intermediate die 28 into cavities 42A. At the same time, the rubber material G contained in pod portions 46B1 and 46B2 is transferred from runners 44B1 and 44B2 formed at the lower intermediate die 30 into cavities 42B. 
     An object of the present invention is to provide a die and a method for manufacturing a core, wherein the core includes a ring-shaped supporting member 16 that is formed by a plate-like member, that is disposed inside a pneumatic tire, and that supports a pneumatic tire by allowing an inner side of a tread portion of the pneumatic tire to be brought into contact with an outer peripheral surface of the supporting member at the time of a deformation of the pneumatic tire due to a decrease of an internal pressure of the tire, and ring-shaped rubber portions that are joined respectively to both widthwise direction edge portions of the supporting member. A pressing machine 10 includes a ring-shaped core die 26 that is brought into contact with the supporting member 16 from a radial direction inner side thereof to support the supporting member 16 while maintaining a non-contact state with the both widthwise direction edge portions of the supporting member 16, and an upper intermediate die 28 and a lower intermediate die 30 that are disposed so as to hold the core die 26 therebetween from a widthwise direction of the core die 26 and that form cavities 42A and 42B for the rubber portions between the upper intermediate die 28 and the core die 26 as well as between the lower intermediate die 30 and the core die 26. The rubber material G contained in the pod portions 46A1, 46A2, 46B1 and 46B2 formed at the dies 28 and 30 are transferred from runners 44A1, 44A2, 44B1 and 44B2 into cavities 42A and 42B.