초록 ▼

The present invention relates to a process for the production of a braking band for a brake disk with venting passages and to a braking band which can be produced by the process. The process comprises the following steps:molding a core ( 200 ) of the braking band in a suitable mold ( 1 ),molding two

The present invention relates to a process for the production of a braking band for a brake disk with venting passages and to a braking band which can be produced by the process. The process comprises the following steps:molding a core ( 200 ) of the braking band in a suitable mold ( 1 ),molding two covers ( 8 ) onto the core in a further suitable mold ( 101 ) so as to form a semi-finished product having a “sandwich” structure,firing the semi-finished product so as to produce a predetermined porosity of the covers,firing the semi-finished product further, in the presence of silicon, at a temperature such as substantially to bring about fusion of the silicon and its infiltration into the covers.

대표청구항 ▼

1. A process for the production of a braking band ( 10 ; 240 ) having venting passages ( 12 ; 229 ), comprising the following steps:moulding a core ( 200 ; 228 ) of the braking band in a suitable mould ( 1 ; 111 ),moulding two covers ( 8 ; 230 ) onto the core in a further suitable mould ( 101 ) so a

1. A process for the production of a braking band ( 10 ; 240 ) having venting passages ( 12 ; 229 ), comprising the following steps:moulding a core ( 200 ; 228 ) of the braking band in a suitable mould ( 1 ; 111 ),moulding two covers ( 8 ; 230 ) onto the core in a further suitable mould ( 101 ) so as to form a semi-finished product having a “sandwich” structure,firing the semi-finished product so as to produce a predetermined porosity of the covers,firing the semi-finished product further, in the presence of silicon, at a temperature such as substantially to bring about fusion of the silicon and its infiltration into the covers. 2. A process for the production of a braking band ( 10 ; 240 ) according to claim 1, in which the step of moulding the core ( 200 ; 228 ) of the braking band comprises the moulding of two half-cores ( 2 ; 220 ) and the juxtaposition and fixing-together thereof to form the core with the venting passages ( 12 ; 229 ). 3. A process for the production of a braking band ( 10 ; 400 ) according to claim 2 in which the moulding of the half-cores comprises the steps of:a) providing a suitable mould ( 1 ; 111 ),b) preparing a mixture comprising a predetermined quantity of fibres and/or filaments constituted substantially by carbon, and a predetermined quantity of an organic binder,c) depositing the mixture in the suitable mould,d) moulding a first half-core ( 2 ; 220 ) in the mould,e) moulding a second half-core ( 2 ; 220 ) by repeating steps a) to d),f) fixing the juxtaposed first and second half-cores together to produce the core in which the venting passages ( 28 ; 229 ) are defined. 4. A process for the production of a braking band according to claim 3 in which the mixture for the moulding of the core comprises filaments of carbon-based materials selected from the group consisting of wood and products of the processing of wood, vegetable fibres, and thermosetting resins. 5. A process for the production of a braking band according to claim 4 in which the materials are sawdust or chippings, hemp and the like, and liquid thermosetting phenolic resins. 6. A process for the production of a braking band according to claim 3 in which the fixing takes place by gluing with a liquid thermosetting resin. 7. A process according to claim 6 in which the resin is a phenolic resin. 8. A process for the production of a braking band according to claim 6 in which the gluing takes place when the first and second half-cores have just come out of the mould. 9. A process for the production of a braking band according to claim 1 in which the step of moulding the covers ( 8 ; 230 ) comprises:providing a suitable mould ( 101 ),depositing a first layer of a mixture in the suitable mould, the mixture comprising a predetermined quantity of fibres and/or filaments constituted substantially by carbon, and a predetermined quantity of an organic binder,positioning and supporting the core ( 200 ; 228 ) in the mould so that it is in contact with the first layer of mixture,depositing a second layer of the mixture on the core,moulding the covers around the core so as to produce a “sandwich” structure. 10. A process for the production of a braking band according to claim 3 in which the step of moulding the covers ( 8 ; 230 ) comprises:providing a suitable mould ( 101 ),depositing a first layer of a mixture in the suitable mould, the mixture comprising a predetermined quantity of fibres and/or filaments constituted substantially by carbon, and a predetermined quantity of an organic binder,positioning and supporting the core ( 200 ; 228 ) in the mould so that it is in contact with the first layer of mixture,depositing a second layer of the mixture on the core,moulding the covers around the core so as to produce a “sandwich” structure. 11. A process for the production of a braking band ( 10 ; 240 ) according to claim 9 in which the core ( 200 ; 229 ) is supported in the mould so as to float on the first la yer of mixture, by means of resilient elements ( 800 ), the elements preferably being springs. 12. A process for the production of a braking band ( 10 ; 240 ) according to claim 10 in which the mixture for the moulding of the core and/or of the covers comprises reinforcing fibres of carbon or of metallic materials. 13. A process for the production of a braking band according to claim 12 in which the reinforcing fibres are SiC, Si 3 N 4 , TiC, or platinum fibres. 14. A process for the production of a braking band according to claim 12 in which the reinforcing fibres are combined with one another or intertwined in bundles which form a single warp or weft thread to constitute a fabric. 15. A process for the production of a braking band according to claim 12 in which the reinforcing fibres constitute a non-woven fabric. 16. A process for the production of a braking band according to claim 15 in which the non-woven fabric is a felt.