Abstract:
Dispositif (1) de vulcanisation pour pneumatique comprenant - un moule (4) de vulcanisation comportant des parties moulantes définissant entre elles une enceinte de cuisson (7) à l'intérieur de laquelle est agencée - une unité de chauffage et de ventilation (20) du fluide caloporteur et coopérant avec une partie centrale (18) de support et de mise en communication d'une arrivée de fluide caloporteur avec ladite enceinte de cuisson (7), Selon l'invention, ladite partie centrale (18) comprend des éléments chauffants (37, 42, 50) qui sont réalisés de manière à être mis en fonctionnement avant la mise en fonctionnement de l'unité de chauffage et de ventilation (20) du fluide caloporteur qui effectue la cuisson du pneumatique.
Abstract:
A method to cure a non-uniform rubber article uses one or more high thermal diffusivity pins in a mold to direct heat to the cure-limiting parts of the article to reduce the total cure time in the mold and increase the uniformity of the cure of the article. Reductions in cure time of up to 20% or more are achieved without substantially changing the function or degrading the performance of the article. The method is particularly useful for curing tires and treads for tires. Finite element analysis or thermocouple probes can used to determine the cure-limiting part(s) for the tire or tread. Using this knowledge, one or more of the high thermal diffusivity pins are located in the mold at positions to transfer heat into the cure- limiting part(s).
Abstract:
A heating unit whose total impedance can be easily adjusted according to the size of the tire mold and capable of using the power supply with high power factor and a tire heating device using the same are provided. A ferromagnetic metal member (10a) heats a tire mold (M1) by heat conduction. An induction heating coil (C1) is disposed on the opposite side of the tire mold (M1) to the ferromagnetic metal member (10a) and produces lines of magnetic force to induction-heat the ferromagnetic metal member (10a). A nonmagnetic conductor (30a) is disposed on the opposite side of the induction heating coil (C1) to the ferromagnetic metal member (10a)to interrupt the lines of magnetic force produced by the induction heating coil (C1). The heating unit (100a) having these components heats the tire mold (M1) containing a tire. First spacers (71a, 72a) and second spacers (21a to 23a) are used to determine the relative positional relation between the nonmagnetic conductor (30a), the induction heating coil (C1), and the ferromagnetic metal member (10a).
Abstract:
A tyre enclosed in a vulcanisation mould (3) is supplied with heat to cause vulcanisation of same. By thermal-detection probes (14, 15, 18) introduced into the tyre (2), monitoring of the cross-linking degree reached in at least one first detection region (14a) and one second detection region (15a) disposed within the tyre (2) is carried out. Heat supply is stopped on occurrence of the following conditions: (i) the crosslinking degree measured in at least one of said detection regions (14a, 15a) reaches a first reference value higher than 90% of the whole cross-linking; (ii) the cross-linking degree measured in each detection region (14a, 15a) has overcome a second pre-established reference value not exceeding about 50% of the whole cross-linking.
Abstract:
Finite element analysis or thermocouple probes are used to determine the state of cure for each zone of a non-uniform, thick rubber article, such as a large tire or a tread for a tire. From this knowledge of those cure-limiting zones, heat transfer elements are added to the mold to enhance the transfer of heat into these cure-limiting zones and to provide a more optimum cure. The use of heat transfer pins and/or mini-sipes are an efficient and practical means of reducing total cure time in the press and optimizing cure state without substantially affecting the performance of the article such as the tire. Reductions in cure time of 10% or more are demonstrated.
Abstract:
Le moule pour pneumatique comprend des première et deuxième coquilles 16, 1 8 destinées à assurer le moulage de flancs latéraux du pneumatique, une pluralité de secteurs 20, 22 répartis dans le sens circonférentiel et destinés à assurer le moulage d'une bande de roulement dudit pneumatique, des premier et deuxième plateaux 12, 14 de support comprenant chacun une face d' appui 12a, 14a contre laquelle est montée axialement en contact la coquille associée, et une pluralité de premier et deuxième moyens de chauffage 42, 44 pour chauffer respectivement au moins la première et la deuxième coquilles 16, 1 8. Chaque plateau 12, 14 de support comprend au moins un corps réalisé en matériau iso lant thermiquement et délimitant la face d' appui 12a, 14a dudit plateau, au moins un évidement 12b, 14b étant formé sur ladite face d' appui et à l' intérieur duquel sont logés les premiers ou deuxièmes moyens de chauffage 42, 44.