WO1999003662A1 - Method for moulding a tyre - Google Patents
Method for moulding a tyre Download PDFInfo
- Publication number
- WO1999003662A1 WO1999003662A1 PCT/EP1998/004279 EP9804279W WO9903662A1 WO 1999003662 A1 WO1999003662 A1 WO 1999003662A1 EP 9804279 W EP9804279 W EP 9804279W WO 9903662 A1 WO9903662 A1 WO 9903662A1
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- WO
- WIPO (PCT)
- Prior art keywords
- mold
- molding
- tire
- basic model
- patterns
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/42—Moulds or cores; Details thereof or accessories therefor characterised by the shape of the moulding surface, e.g. ribs or grooves
- B29C33/424—Moulding surfaces provided with means for marking or patterning
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/38—Moulds or cores; Details thereof or accessories therefor characterised by the material or the manufacturing process
- B29C33/3842—Manufacturing moulds, e.g. shaping the mould surface by machining
- B29C33/3857—Manufacturing moulds, e.g. shaping the mould surface by machining by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2030/00—Pneumatic or solid tyres or parts thereof
Definitions
- the subject of the invention is a method of molding a tire, and more particularly a method of molding making it possible to reproduce a texture on at least part of the surface of a tire.
- a mold is generally used, made up of several parts which, as soon as they are assembled to form said mold, define a molding volume for molding said tire.
- a part is more specifically intended for molding the region of the tire constituting the tread, said tread being provided with a sculpture molded by elements of relief carried by said mold part; the other parts constituting the mold are intended to mold the external surfaces of the sidewalls and of the beads of said tire.
- Each part intended for molding a flank is designated by the term shell.
- the metal shells thus produced are then subjected to an engraving work in order to engrave therein in a precise manner the various desired patterns on the tire, such as for example, the size of the tire, the indications relating to the conditions of use, the pictograms appearing the recommended use of said tire, as well as possibly any pattern conferring an aesthetic effect on the surface of the tire (note the increasing demand relating to this last point).
- a defective mold part due to a machining error during the etching operation causes the said part to be rejected in order to avoid producing tires having appearance defects after molding.
- the object of the invention is to provide an economical method of molding a tire provided on at least part of the outer surface with a texture formed by a plurality of recesses and reliefs of low and / or medium height arranged relative to each other in a determined manner and reproducing the surface condition of a predetermined material.
- Another object of the invention is to inexpensively produce at least part of a tire mold comprising, on at least part of its molding surface, a plurality of raised patterns of medium height allowing the molding of recessed patterns on at least part of the surface of a tire.
- the method of molding a tire provided on at least part of the outer surface with a texture comprises the following steps: a - production of a basic model by machining, said model reproducing the external geometry of the part of the tire to be molded; b - on at least part of the external surface of the basic model, fitting of a body, one surface of which is intended to form part of the surface of the basic model, said body being provided on said surface with the plurality intaglio and raised patterns (in addition to the fixing means can be provided to maintain said body on the model); c- on this basic model, molding of an imprint in a material which can be poured and solidifiable, said material being characterized in the solid state by an elasticity of deformation suitable for allowing the demolding of said imprint, without having to destroy the basic model; d- production by molding on the imprint of a counter-mold of flowable and solidifiable material, said material resistant to temperatures above 200 ° C; e- molding of the corresponding mold part by casting
- the method according to the invention offers the advantage of allowing the production of an almost unlimited number of strictly identical tires from a single mold; in addition, it is also easy to manufacture a large number of counter molds and therefore strictly identical mold parts from a single basic model.
- step b of the method according to the invention can be carried out as follows: the plurality of patterns formed on the external surface of the basic model is obtained by partial or total covering of said surface with at least one body in particular in the form of a plurality of grains, a leaf of a plant, a tissue or any other shape so as to form on said surface a large number of hollows and reliefs intended to be reproduced by molding on at least part of the surface of the tire.
- This way of doing things has the advantage of allowing the faithful reproduction of a given texture pattern; in addition, it is easy to modify the surface of the tire mold by simply removing the covering material or materials followed by laying a new covering material appearing in another pattern.
- the same basic model makes it possible to produce a plurality of molds of the same dimension of tire having different textures.
- step b of the method according to the invention consists in producing at least part of the basic model in a material capable of either being etched by chemical attack or by a laser (resin material for example) to reproduce a predetermined pattern formed by a large number of hollows and reliefs of low height per unit area.
- Another advantage of the method according to the invention lies in the appreciable reduction in the cost of obtaining each tire mold part.
- this method also makes it possible to mold tires comprising on their external surface a large number of relief elements so as to give it an aesthetic effect such as for example obtaining a reinforced shine (thus meeting the expectations of manufacturers automobiles and motorists) by using height patterns preferably of the order of 0.5 mm or less (possibly even going down to a few microns).
- the tire molding method according to the invention also has the advantage of allowing the basic model to be refurbished easily and inexpensively, for example by replacing the coating material when it is worn or deteriorated after use. To further increase the decorative effect and enhance certain predetermined regions on a tire, it is possible to use several types of body or covering materials and to arrange them in different places on the same basic model.
- FIG. 1 shows a partial view of the surface of part of a basic model, said part locally comprising a plurality of relief elements forming a texture having a visible aesthetic effect.
- FIG. 1 schematically shows part of a basic model 1 made of resin and intended for molding a shell part intended itself for molding a tire sidewall.
- This part of the basic model was produced by direct machining in a block of material and reproduces the geometry of a part of the surface of a tire sidewall.
- a textile fabric 4 constituting a partial covering body of said model.
- the weft 5 and warp 6 son of this fabric form on said surface a plurality of relief patterns; the average diameter of said wires is close to 0.4 mm.
- the maximum amplitude between the recesses formed in the zones 7 where there are no warp threads or weft threads and the reliefs 8 of maximum height is substantially equal. at 0.5 mm.
- the strip of fabric has been previously coated with a coating on its face intended to come into contact with the basic model so as to prevent the penetration of the material constituting the impression during the molding of said impression under the warp and weft yarns (which would result in tearing of said fabric during the release of the imprint and a lower quality of reproduction 1 -
- this strip was placed in the right position and glued to the basic model while playing on the elasticity of the fabric to closely follow the external geometry of said model.
- the average number of depressions on the basic model that is to say the number of patterns in relief on the tire mold per unit area is at least equal to 2.10 per square meter. This value makes it possible to measure how efficient the process according to the invention is and economically advantageous compared to the usual processes.
- a shell for molding a tire sidewall may be formed from several concentric annular parts, the clearances between said annular parts being suitable for allowing good evacuation of the air trapped during the molding of a tire and at least one of said parts being obtained. by the method of the invention.
- the patterns in relief on the mold have maximum heights at most equal to 0.5 mm so as to facilitate the venting of the air occluded between the mold and a tire during molding to avoid the appearance of defects of aspect.
- the described method allows the faithful reproduction on the surface of a tire of any textures and very particularly textures formed of patterns whose reliefs and hollows have very small heights, up to a few microns and with a very high density, by example greater than 1. 10 depressions or reliefs per square meter (the reproduction of such textures on tire molds is almost impossible with the usual methods of manufacturing said molds).
- the implementation of this process makes it possible to produce various surface conditions on a tire, such as for example various particularly aesthetic patterns or patterns giving the said surface a particular feel (for example: velvety of a velvet fabric).
- a mold is made against the imprint in a solidifying material and characterized in that after solidification said material is practically non-deformable.
- the external surface of said counter-mold reproduces identically the surface of the basic resin model in every detail.
- a very good material is for example plaster chosen for its particle size which is particularly well suited to reproducing the finest relief patterns.
- the mold part is molded by pouring onto the counter-mold a flowable and solidifiable material, for example an aluminum or steel alloy.
- the method according to the invention also makes it possible to obtain mold parts for molding on the running surface of a tire tread a plurality of hollow patterns, forming a texture, so as to give said strip. in new condition, improved characteristics in wet grip.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
Abstract
Description
PROCEDE DE MOULAGE D'UN PNEUMATIQUE. PROCESS FOR MOLDING A TIRE.
L'invention a pour objet un procédé de moulage d'un pneumatique, et plus particulièrement un procédé de moulage permettant de reproduire une texture sur au moins une partie de la surface d'un pneumatique.The subject of the invention is a method of molding a tire, and more particularly a method of molding making it possible to reproduce a texture on at least part of the surface of a tire.
Pour mouler un pneumatique on utilise un moule en règle générale composé de plusieurs parties qui, dès lors qu'elles sont assemblées pour former ledit moule, délimitent un volume de moulage pour mouler ledit pneumatique. Une partie est plus spécifiquement destinée à mouler la région du pneumatique constituant la bande de roulement, ladite bande étant pourvue d'une sculpture moulée par des éléments de relief portés par ladite partie de moule; les autres parties constituant le moule sont destinées à mouler les surfaces extérieures des flancs et des bourrelets dudit pneumatique. Chaque partie destinée à mouler un flanc est désignée par le terme de coquille.To mold a tire, a mold is generally used, made up of several parts which, as soon as they are assembled to form said mold, define a molding volume for molding said tire. A part is more specifically intended for molding the region of the tire constituting the tread, said tread being provided with a sculpture molded by elements of relief carried by said mold part; the other parts constituting the mold are intended to mold the external surfaces of the sidewalls and of the beads of said tire. Each part intended for molding a flank is designated by the term shell.
Pour fabriquer les différentes parties d'un moule de pneumatique, il est connu :To manufacture the different parts of a tire mold, it is known:
- pour la réalisation de la partie moulant la bande de roulement, d'employer la technique de moulage par coulée d'un alliage d'aluminium sur un contre-moule dont la surface de moulage reproduit les éléments de la sculpture de ladite bande (blocs, nervures);- for the production of the part molding the tread, to use the molding technique by casting an aluminum alloy on a counter mold whose molding surface reproduces the elements of the sculpture of said band (blocks , ribs);
- de réaliser les coquilles par tournage dans une pièce massive en métal.- to make the shells by turning in a massive piece of metal.
Les coquilles métalliques ainsi réalisées sont ensuite soumises à un travail de gravure pour y graver de manière précise les différents motifs souhaités sur le pneumatique, comme par exemple, la dimension du pneumatique, les mentions relatives aux conditions d'utilisation, des pictogrammes figurant l'utilisation préconisée dudit pneumatique, ainsi qu'éventuellement tout motif conférant un effet esthétique à la surface du pneumatique (il faut noter la demande croissante relative à ce dernier point).The metal shells thus produced are then subjected to an engraving work in order to engrave therein in a precise manner the various desired patterns on the tire, such as for example, the size of the tire, the indications relating to the conditions of use, the pictograms appearing the recommended use of said tire, as well as possibly any pattern conferring an aesthetic effect on the surface of the tire (note the increasing demand relating to this last point).
Pour y parvenir, il faut usiner la coquille métallique par un fraisage de très grande précision, d'autant plus difficile à réaliser que les surfaces sur lesquelles il est pratiqué sont des surfaces courbes; ces opérations d'usinage de précision nécessitent un outillage complexe et requièrent un temps d'usinage relativement long. De plus, la technique d'usinage employée impose une limite quant à la taille des motifs qu'il est possible d'obtenir; en effet, en deçà d'une dimension donnée de motif, le fraisage même piloté par un ordinateur ne permet pas d'atteindre une finesse extrême de motif. En particulier, la réalisation de textures, formées d'une pluralité de creux et de reliefs pouvant être de faible amplitude (c'est-à-dire entre 5 microns et 0.5 mm) disposés suivant un ou plusieurs motifs choisis au préalable, est impossible à réaliser par ce procédé. Pour réaliser de tels motifs, on connaît d'autres techniques (attaque chimique ou laser) qui sont particulièrement coûteuses et longues à mettre en oeuvre.To achieve this, it is necessary to machine the metal shell by very high-precision milling, which is all the more difficult to achieve as the surfaces on which it is practiced are curved surfaces; these precision machining operations require complex tools and require a relatively long machining time. In addition, the machining technique used places a limit on the size of the patterns that can be obtained; in fact, below a given dimension of pattern, milling even controlled by a computer does not make it possible to achieve an extreme fineness of pattern. In particular, the production of textures, formed by a plurality of hollows and reliefs which may be of small amplitude (that is to say between 5 microns and 0.5 mm) arranged in one or more previously chosen patterns, is impossible. to be made by this process. To produce such patterns, other techniques are known (chemical or laser attack) which are particularly expensive and time-consuming to implement.
En outre, la réalisation de motifs en creux sur le flanc du pneumatique requiert la réalisation de l'empreinte des mêmes motifs mais en relief sur la coquille (c'est à dire en saillie sur la surface de moulage de la coquille); il est industriellement très difficile et très coûteux de vouloir essayer d'obtenir ces reliefs sur une coquille par usinage voire par apport de matière.In addition, the production of recessed patterns on the sidewall of the tire requires the production of the imprint of the same patterns but in relief on the shell (that is to say protruding from the molding surface of the shell); it is industrially very difficult and very costly to try to obtain these reliefs on a shell by machining or even by adding material.
Pour produire un grand nombre de pneumatiques comportant sur leurs surfaces externes des inscriptions ou des motifs de très bonne qualité graphique, il est nécessaire de disposer d'une pluralité de moules identiques réalisés et gravés un à un, ce qui amplifie encore les coûts de réalisation puisque chaque coquille doit faire l'objet d'une gravure particulière et cependant identique aux gravures des autres coquilles destinées au moulage de pneumatiques similaires.To produce a large number of tires having inscriptions or patterns of very good graphic quality on their external surfaces, it is necessary to have a plurality of identical molds produced and engraved one by one, which further increases the production costs. since each shell must be the subject of a specific engraving and however identical to the engravings of the other shells intended for the molding of similar tires.
Il faut encore ajouter qu'une pièce de moule défectueuse du fait d'une erreur d'usinage durant l'opération de gravure, entraîne le rebut de ladite pièce pour éviter de produire des pneumatiques comportant des défauts d'aspect après moulage.It should also be added that a defective mold part due to a machining error during the etching operation causes the said part to be rejected in order to avoid producing tires having appearance defects after molding.
Le constat qui vient d'être fait révèle qu'il n'existe pas de procédé à la fois industriel et économique de réalisation de pneumatiques pourvus de motifs formant une texture reproduisant une texture donnée et cela sur une au moins une partie de leur surface extérieure au moyen d'une pièce d'un moule de pneumatique comportant, sur au moins une partie de sa surface de moulage, une pluralité de motifs composés de parties en relief et de parties en creux de faible et/ou moyenne hauteur par rapport à la surface de moulage, ladite pluralité de motifs étant agencée pour former une texture reproduisant par exemple la texture d'un tissu ou de toute autre structure. Par hauteur faible, on entend une hauteur de motif allant de 5 microns à 0.5 mm et par hauteur moyenne, on entend une hauteur comprise entre 0.5 mm et 5 mm.The observation which has just been made reveals that there is no process, both industrial and economical, for producing tires provided with patterns forming a texture reproducing a given texture, and this on at least part of their outer surface. by means of a part of a tire mold comprising, on at at least part of its molding surface, a plurality of patterns composed of raised parts and of hollow parts of low and / or medium height relative to the molding surface, said plurality of patterns being arranged to form a texture reproducing by example the texture of a fabric or any other structure. By low height is meant a pattern height ranging from 5 microns to 0.5 mm and by medium height is meant a height between 0.5 mm and 5 mm.
L'objet de l'invention est de proposer un procédé économique de moulage d'un pneumatique pourvu sur au moins une partie de surface extérieure d'une texture formée d'une pluralité de creux et de reliefs de faible et/ou moyenne hauteur agencés les uns par rapport aux autres de manière déterminée et reproduisant l'état de surface d'un matériau prédéterminé. Un autre objet de l'invention est de réaliser de façon peu coûteuse au moins une partie d'un moule de pneumatique comportant, sur une partie au moins de sa surface de moulage, une pluralité de motifs en relief de hauteur moyenne permettant le moulage de motifs en creux sur une partie au moins de la surface d'un pneumatique.The object of the invention is to provide an economical method of molding a tire provided on at least part of the outer surface with a texture formed by a plurality of recesses and reliefs of low and / or medium height arranged relative to each other in a determined manner and reproducing the surface condition of a predetermined material. Another object of the invention is to inexpensively produce at least part of a tire mold comprising, on at least part of its molding surface, a plurality of raised patterns of medium height allowing the molding of recessed patterns on at least part of the surface of a tire.
Selon l'invention, le procédé de moulage d'un pneumatique pourvu sur au moins une partie de surface extérieure d'une texture comporte les étapes suivantes : a - réalisation d'un modèle de base par usinage, ledit modèle reproduisant la géométrie externe de la partie du pneumatique à mouler; b - sur au moins une partie de la surface externe du modèle de base, mise en place d'un corps dont une surface est destinée à former une partie de la surface du modèle de base, ledit corps étant pourvu sur ladite surface de la pluralité de motifs en creux et en relief (en complément des moyens de fixation peuvent être prévus pour assurer le maintien dudit corps sur le modèle); c- sur ce modèle de base, moulage d'une empreinte dans un matériau pouvant être coulé et solidifiable, ledit matériau étant caractérisé à l'état solide par une élasticité de déformation appropriée pour permettre le démoulage de ladite empreinte, sans avoir à détruire le modèle de base; d- réalisation par moulage sur l'empreinte d'un contre-moule en matériau coulable et solidifiable, ledit matériau résistant à des températures supérieures à 200°C; e- moulage de la pièce de moule correspondante par coulée d'un alliage métallique sur le contre-moule; f- démoulage de la pièce de moule, éventuellement par destruction du contre-moule; g- assemblage de la pièce de moule pour constituer un moule de pneumatique; h- mise en place d'une ébauche de pneumatique non vulcanisée et non moulée dans le moule; i- moulage et vulcanisation de l'ébauche de pneumatique.According to the invention, the method of molding a tire provided on at least part of the outer surface with a texture comprises the following steps: a - production of a basic model by machining, said model reproducing the external geometry of the part of the tire to be molded; b - on at least part of the external surface of the basic model, fitting of a body, one surface of which is intended to form part of the surface of the basic model, said body being provided on said surface with the plurality intaglio and raised patterns (in addition to the fixing means can be provided to maintain said body on the model); c- on this basic model, molding of an imprint in a material which can be poured and solidifiable, said material being characterized in the solid state by an elasticity of deformation suitable for allowing the demolding of said imprint, without having to destroy the basic model; d- production by molding on the imprint of a counter-mold of flowable and solidifiable material, said material resistant to temperatures above 200 ° C; e- molding of the corresponding mold part by casting a metal alloy on the counter-mold; f- demolding of the mold part, possibly by destruction of the counter mold; g- assembly of the mold part to constitute a tire mold; h- fitting of a blank of unvulcanized tire which is not molded in the mold; i- molding and vulcanization of the tire blank.
Le procédé selon l'invention offre l'avantage de permettre la réalisation d'un nombre quasiment illimité de pneumatiques rigoureusement identiques à partir d'un moule unique; en outre, il est également aisé de fabriquer un grand nombre de contre- moules et donc de parties de moule rigoureusement identiques à partir d'un modèle de base unique.The method according to the invention offers the advantage of allowing the production of an almost unlimited number of strictly identical tires from a single mold; in addition, it is also easy to manufacture a large number of counter molds and therefore strictly identical mold parts from a single basic model.
Il est bien entendu possible de prévoir en complément une gravure pour réaliser les inscriptions usuelles (dimensions du pneumatique, marque ou autre logo) soit directement sur le modèle de base soit sur la partie de moule de pneumatique obtenue. Il est également possible de disposer, sur le modèle de base, des plaquettes métalliques ou en tout autre matériau, lesdites plaquettes portant des marquages appropriés.It is of course possible to additionally provide an engraving to make the usual inscriptions (dimensions of the tire, brand or other logo) either directly on the basic model or on the tire mold part obtained. It is also possible to have metal plates or any other material on the basic model, said plates bearing appropriate markings.
De manière avantageuse, l'étape b du procédé selon l'invention peut être réalisée de la façon suivante : la pluralité de motifs formés sur la surface externe du modèle de base est obtenue par le recouvrement partiel ou total de ladite surface avec au moins un corps se présentant notamment sous la forme d'une pluralité de grains, d'une feuille d'un végétal, d'un tissu ou de tout autre forme de façon à former sur ladite surface un grand nombre de creux et de reliefs destinés à être reproduits par moulage sur au moins une partie de la surface du pneumatique. Cette façon de faire offre l'intérêt de permettre la reproduction fidèle d'un motif de texture donné; en outre, il est aisé de procéder à une modification de la surface du moule de pneumatique en procédant simplement à l'enlèvement du ou des matériaux de recouvrement suivi de la pose d'un nouveau matériau de recouvrement figurant un autre motif. Ainsi, un même modèle de base permet de réaliser une pluralité de moules d'une même dimension de pneumatique ayant des textures différentes.Advantageously, step b of the method according to the invention can be carried out as follows: the plurality of patterns formed on the external surface of the basic model is obtained by partial or total covering of said surface with at least one body in particular in the form of a plurality of grains, a leaf of a plant, a tissue or any other shape so as to form on said surface a large number of hollows and reliefs intended to be reproduced by molding on at least part of the surface of the tire. This way of doing things has the advantage of allowing the faithful reproduction of a given texture pattern; in addition, it is easy to modify the surface of the tire mold by simply removing the covering material or materials followed by laying a new covering material appearing in another pattern. Thus, the same basic model makes it possible to produce a plurality of molds of the same dimension of tire having different textures.
Une autre alternative de réalisation de l'étape b du procédé selon l'invention consiste à réaliser une partie au moins du modèle de base dans un matériau susceptible soit d'être gravé par attaque chimique ou soit par un laser (matériau résine par exemple) pour reproduire un motif prédéterminé formé d'un grand nombre de creux et de reliefs de faible hauteur par unité de surface.Another alternative for carrying out step b of the method according to the invention consists in producing at least part of the basic model in a material capable of either being etched by chemical attack or by a laser (resin material for example) to reproduce a predetermined pattern formed by a large number of hollows and reliefs of low height per unit area.
Un autre avantage du procédé selon l'invention réside dans la réduction sensible du coût d'obtention de chaque pièce de moule de pneumatique.Another advantage of the method according to the invention lies in the appreciable reduction in the cost of obtaining each tire mold part.
Dans le cas de motifs présentant des contre-dépouilles réalisés sur le modèle de base, il est alors judicieux d'employer un matériau suffisamment déformable et élastique pour effectuer le moulage et le démoulage de l'empreinte sans avoir à détruire le modèle de base.In the case of patterns having undercuts made on the basic model, it is then advisable to use a material that is sufficiently deformable and elastic to perform the molding and demolding of the imprint without having to destroy the basic model.
De manière avantageuse, ce procédé permet également de mouler des pneumatiques comportant sur leur surface extérieure un grand nombre d'éléments de relief de manière à conférer à celui-ci un effet esthétique comme par exemple obtenir une brillance renforcée (répondant ainsi aux attentes des constructeurs automobiles et des automobilistes) en utilisant des motifs de hauteur préférentiellement de l'ordre de 0.5 mm ou moins (pouvant même descendre jusqu'à quelques microns).Advantageously, this method also makes it possible to mold tires comprising on their external surface a large number of relief elements so as to give it an aesthetic effect such as for example obtaining a reinforced shine (thus meeting the expectations of manufacturers automobiles and motorists) by using height patterns preferably of the order of 0.5 mm or less (possibly even going down to a few microns).
Le procédé de moulage de pneumatique selon l'invention présente en outre l'avantage de permettre facilement et à moindre coût la remise à neuf du modèle de base par exemple en remplaçant le matériau de revêtement lorsque celui-ci est usé ou détérioré après usage. Pour augmenter encore l'effet décoratif et mettre en valeur certaines régions prédéterminées sur un pneumatique, il est possible d'employer plusieurs types de corps ou matériaux de recouvrement et de les disposer en des endroits différents sur le même modèle de base.The tire molding method according to the invention also has the advantage of allowing the basic model to be refurbished easily and inexpensively, for example by replacing the coating material when it is worn or deteriorated after use. To further increase the decorative effect and enhance certain predetermined regions on a tire, it is possible to use several types of body or covering materials and to arrange them in different places on the same basic model.
L'invention sera mieux comprise à l'aide de la figure unique jointe à la présente description et qui n'est en rien limitative des possibilités de ladite invention.The invention will be better understood using the single figure attached to this description and which is in no way limiting the possibilities of said invention.
- La figure 1 montre une vue partielle de la surface d'une partie d'un modèle de base, ladite partie comportant localement une pluralité d'éléments de relief formant une texture présentant un effet esthétique visible.- Figure 1 shows a partial view of the surface of part of a basic model, said part locally comprising a plurality of relief elements forming a texture having a visible aesthetic effect.
La figure 1 montre schématiquement une partie d'un modèle de base 1 réalisée en résine et destinée au moulage d'une partie de coquille destinée elle-même au moulage d'un flanc de pneumatique.FIG. 1 schematically shows part of a basic model 1 made of resin and intended for molding a shell part intended itself for molding a tire sidewall.
Cette partie de modèle de base a été réalisée par usinage direct dans un bloc de matière et reproduit la géométrie d'une partie de la surface d'un flanc de pneumatique.This part of the basic model was produced by direct machining in a block of material and reproduces the geometry of a part of the surface of a tire sidewall.
Sur une partie 3 de la surface 2 du modèle de base 1 sur laquelle il est prévu de mouler une empreinte, on distingue un tissu textile 4 constituant un corps de recouvrement partiel dudit modèle. Les fils de trame 5 et de chaîne 6 de ce tissu forment sur ladite surface une pluralité de motifs en relief; le diamètre moyen desdits fils est voisin de 0.4 mm. L'amplitude maximale entre les creux formés dans les zones 7 où il y a ni fils de chaîne ni fils de trame et les reliefs 8 de hauteur maximale (correspondant aux zones de chevauchement des fils de chaîne et des fils de trame) est sensiblement égale à 0.5 mm.On a part 3 of the surface 2 of the base model 1 on which it is planned to mold an imprint, there is a textile fabric 4 constituting a partial covering body of said model. The weft 5 and warp 6 son of this fabric form on said surface a plurality of relief patterns; the average diameter of said wires is close to 0.4 mm. The maximum amplitude between the recesses formed in the zones 7 where there are no warp threads or weft threads and the reliefs 8 of maximum height (corresponding to the overlapping zones of the warp threads and weft threads) is substantially equal. at 0.5 mm.
Dans le cas présent, la bande de tissu a été préalablement recouverte d'un enduit sur sa face destinée à venir en contact avec le modèle de base de manière à empêcher la pénétration du matériau constituant l'empreinte pendant le moulage de ladite empreinte sous les fils de chaîne et de trame (ce qui aurait pour conséquence, un arrachement dudit tissu pendant le démoulage de l'empreinte ainsi qu'une moindre qualité de reproduction 1 -In the present case, the strip of fabric has been previously coated with a coating on its face intended to come into contact with the basic model so as to prevent the penetration of the material constituting the impression during the molding of said impression under the warp and weft yarns (which would result in tearing of said fabric during the release of the imprint and a lower quality of reproduction 1 -
de la texture). Ensuite, cette bande a été placée dans la bonne position et collée sur le modèle de base en jouant sur l'élasticité du tissu pour suivre au plus près la géométrie externe dudit modèle.texture). Then, this strip was placed in the right position and glued to the basic model while playing on the elasticity of the fabric to closely follow the external geometry of said model.
Dans le cas d'espèce, le nombre moyen de creux sur le modèle de base c'est à dire le nombre de motifs en relief sur le moule de pneumatique par unité de surface est au moins égal à 2. 10 par mètre carré. Cette valeur permet de mesurer combien le procédé selon l'invention est performant et intéressant économiquement comparativement aux procédés usuels.In the present case, the average number of depressions on the basic model, that is to say the number of patterns in relief on the tire mold per unit area is at least equal to 2.10 per square meter. This value makes it possible to measure how efficient the process according to the invention is and economically advantageous compared to the usual processes.
Une coquille pour mouler un flanc de pneumatique peut être formée de plusieurs parties annulaires concentriques, les jeux entre lesdites parties annulaires étant appropriés pour permettre une bonne évacuation de l'air occlus pendant le moulage d'un pneumatique et au moins une desdites parties étant obtenue par le procédé de l'invention. Ainsi, il est possible de remplacer une partie seulement d'une coquille par une autre de même dimension mais comportant un motif décoratif différent sur sa surface de moulage.A shell for molding a tire sidewall may be formed from several concentric annular parts, the clearances between said annular parts being suitable for allowing good evacuation of the air trapped during the molding of a tire and at least one of said parts being obtained. by the method of the invention. Thus, it is possible to replace only part of a shell with another of the same size but having a different decorative pattern on its molding surface.
Préférentiellement, les motifs en relief sur le moule ont des hauteurs maximales au plus égales à 0.5 mm de façon à faciliter l'éventation de l'air occlus entre le moule et un pneumatique en cours de moulage pour éviter l'apparition de défauts d'aspect.Preferably, the patterns in relief on the mold have maximum heights at most equal to 0.5 mm so as to facilitate the venting of the air occluded between the mold and a tire during molding to avoid the appearance of defects of aspect.
Le procédé décrit permet la reproduction fidèle sur la surface d'un pneumatique de textures quelconques et tout particulièrement des textures formées de motifs dont les reliefs et les creux ont des hauteurs très petites, jusqu'à quelques microns et avec une densité très grande, par exemple supérieure à 1. 10 creux ou reliefs par mètre carré (la reproduction de telles textures sur des moules de pneumatique est quasiment impossible avec les procédés usuels de fabrication desdits moules). La mise en oeuvre de ce procédé permet de réaliser des états de surface variés sur un pneumatique, comme par exemple divers motifs particulièrement esthétiques ou des motifs conférant à ladite surface un toucher particulier (par exemple : velouté d'un tissu de velours).The described method allows the faithful reproduction on the surface of a tire of any textures and very particularly textures formed of patterns whose reliefs and hollows have very small heights, up to a few microns and with a very high density, by example greater than 1. 10 depressions or reliefs per square meter (the reproduction of such textures on tire molds is almost impossible with the usual methods of manufacturing said molds). The implementation of this process makes it possible to produce various surface conditions on a tire, such as for example various particularly aesthetic patterns or patterns giving the said surface a particular feel (for example: velvety of a velvet fabric).
Description des étapes du procédé pour mouler la texture d'un tissu sur la surface extérieure d'un flanc de pneumatique : Après avoir construit le modèle de base reproduisant la géométrie dudit flanc et après avoir recouvert ledit modèle avec un tissu selon la figure 1, on procède au moulage d'une pièce de moule en coulant sur le modèle de base un matériau coulable et solidifiable et pouvant éventuellement rester élastique après solidification. Un matériau pouvant être utilisé dans cette application est par exemple du silastène.Description of the process steps for molding the texture of a fabric on the outer surface of a tire sidewall: After having constructed the basic model reproducing the geometry of said sidewall and after having covered said model with a fabric according to FIG. 1, one proceeds to the molding of a mold part by casting on the basic model a flowable and solidifiable material which can possibly remain elastic after solidification. A material which can be used in this application is for example silastene.
Après démoulage de l'empreinte, on réalise, par moulage sur l'empreinte, un contre-moule dans un matériau se solidifiant et caractérisé par le fait qu'après solidification ledit matériau est pratiquement indéformable. La surface extérieure dudit contre-moule reproduit à l'identique la surface du modèle de base en résine dans ses moindres détails. Un très bon matériau est par exemple du plâtre choisi pour sa granulométrie particulièrement bien adaptée à la reproduction des motifs de relief les plus fins.After demolding the imprint, a mold is made against the imprint in a solidifying material and characterized in that after solidification said material is practically non-deformable. The external surface of said counter-mold reproduces identically the surface of the basic resin model in every detail. A very good material is for example plaster chosen for its particle size which is particularly well suited to reproducing the finest relief patterns.
Après démoulage du contre-moule en plâtre, on moule la partie de moule en coulant sur le contre-moule une matière coulable et solidifiable, comme par exemple un alliage d'aluminium ou d'acier.After demoulding the plaster counter-mold, the mold part is molded by pouring onto the counter-mold a flowable and solidifiable material, for example an aluminum or steel alloy.
Après réalisation de la pièce de moule de pneumatique selon le procédé décrit, il peut être réalisé une finition pour parfaire l'assemblage des différents éléments constitutifs dudit moule. Cette opération de finition d'une pièce de moule est du reste considérablement simplifiée par rapport aux opérations actuelles puisqu'il n'y a pas de marquage à réaliser sur ladite pièce.After the tire mold part has been produced according to the method described, a finish can be produced to perfect the assembly of the various constituent elements of said mold. This operation of finishing a mold part is, moreover, considerably simplified compared to current operations since there is no marking to be carried out on said part.
Les différentes pièces constitutives d'un moule de pneumatique sont alors assemblées avant de procéder au moulage d'un pneumatique.The various component parts of a tire mold are then assembled before molding a tire.
Le procédé selon l'invention permet également d'obtenir des pièces de moule pour mouler à la surface de roulement d'une bande de roulement d'un pneumatique une pluralité de motifs en creux, formant une texture, de façon à conférer à ladite bande à l'état neuf des caractéristiques améliorées en adhérence sur sol mouillé. The method according to the invention also makes it possible to obtain mold parts for molding on the running surface of a tire tread a plurality of hollow patterns, forming a texture, so as to give said strip. in new condition, improved characteristics in wet grip.
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR97/09243 | 1997-07-18 | ||
| FR9709243 | 1997-07-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1999003662A1 true WO1999003662A1 (en) | 1999-01-28 |
Family
ID=9509441
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1998/004279 Ceased WO1999003662A1 (en) | 1997-07-18 | 1998-07-10 | Method for moulding a tyre |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO1999003662A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000058066A1 (en) * | 1999-03-31 | 2000-10-05 | Gravutex Eschmann International Limited | Rapid texture prototyping |
| US6558496B1 (en) | 1997-11-28 | 2003-05-06 | Eschmann-Stahl Gmbh & Co., Kg | Rapid texture prototyping |
| US6565693B1 (en) | 1997-11-28 | 2003-05-20 | Eschmann-Stahl Gmbh & Co. Kg | Rapid texture prototyping |
| DE102007005455B4 (en) * | 2007-02-03 | 2017-03-23 | Continental Reifen Deutschland Gmbh | Tire vulcanization mold and method for producing a tire vulcanization mold |
| CN116604747A (en) * | 2023-07-20 | 2023-08-18 | 山东豪迈机械科技股份有限公司 | Mould manufacturing method based on additive manufacturing technology and tyre |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB844714A (en) * | 1957-05-20 | 1960-08-17 | Firestone Tire & Rubber Co | Method of producing molds |
| GB2085612A (en) * | 1980-08-04 | 1982-04-28 | Goodyear Tire & Rubber | Method of making a sight model said model its use as a mold part and said mold |
| JPS62214910A (en) * | 1986-03-17 | 1987-09-21 | Keizo Saeki | Manufacture of tire |
| FR2631861A1 (en) * | 1988-05-27 | 1989-12-01 | Staphane Sa | Process for the manufacture of an injection mould for a thermoplastic |
| EP0384775A2 (en) * | 1989-02-23 | 1990-08-29 | Bridgestone Corporation | Split dies for casting small segments of tire mold |
| EP0400672A2 (en) * | 1989-06-02 | 1990-12-05 | American Bank Note Holographics, Inc. | Plastic molding of articles including a hologram or other microstructure |
| DE4324970A1 (en) * | 1993-07-24 | 1995-01-26 | Benecke Kaliko Ag | Process for producing an embossing roller for continuously embossing the surface of a thermoplastic film with a pattern |
| EP0668136A1 (en) * | 1994-02-04 | 1995-08-23 | The Goodyear Tire & Rubber Company | Method and apparatus for making a tire mold |
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1998
- 1998-07-10 WO PCT/EP1998/004279 patent/WO1999003662A1/en not_active Ceased
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB844714A (en) * | 1957-05-20 | 1960-08-17 | Firestone Tire & Rubber Co | Method of producing molds |
| GB2085612A (en) * | 1980-08-04 | 1982-04-28 | Goodyear Tire & Rubber | Method of making a sight model said model its use as a mold part and said mold |
| JPS62214910A (en) * | 1986-03-17 | 1987-09-21 | Keizo Saeki | Manufacture of tire |
| FR2631861A1 (en) * | 1988-05-27 | 1989-12-01 | Staphane Sa | Process for the manufacture of an injection mould for a thermoplastic |
| EP0384775A2 (en) * | 1989-02-23 | 1990-08-29 | Bridgestone Corporation | Split dies for casting small segments of tire mold |
| EP0400672A2 (en) * | 1989-06-02 | 1990-12-05 | American Bank Note Holographics, Inc. | Plastic molding of articles including a hologram or other microstructure |
| DE4324970A1 (en) * | 1993-07-24 | 1995-01-26 | Benecke Kaliko Ag | Process for producing an embossing roller for continuously embossing the surface of a thermoplastic film with a pattern |
| EP0668136A1 (en) * | 1994-02-04 | 1995-08-23 | The Goodyear Tire & Rubber Company | Method and apparatus for making a tire mold |
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| Title |
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| PATENT ABSTRACTS OF JAPAN vol. 012, no. 073 (M - 674) 8 March 1988 (1988-03-08) * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6558496B1 (en) | 1997-11-28 | 2003-05-06 | Eschmann-Stahl Gmbh & Co., Kg | Rapid texture prototyping |
| US6565693B1 (en) | 1997-11-28 | 2003-05-20 | Eschmann-Stahl Gmbh & Co. Kg | Rapid texture prototyping |
| WO2000058066A1 (en) * | 1999-03-31 | 2000-10-05 | Gravutex Eschmann International Limited | Rapid texture prototyping |
| DE102007005455B4 (en) * | 2007-02-03 | 2017-03-23 | Continental Reifen Deutschland Gmbh | Tire vulcanization mold and method for producing a tire vulcanization mold |
| CN116604747A (en) * | 2023-07-20 | 2023-08-18 | 山东豪迈机械科技股份有限公司 | Mould manufacturing method based on additive manufacturing technology and tyre |
| CN116604747B (en) * | 2023-07-20 | 2023-09-29 | 山东豪迈机械科技股份有限公司 | A mold manufacturing method and tire based on additive manufacturing technology |
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