WO2015097370A1 - Method for retreading a tyre using warm air - Google Patents
Method for retreading a tyre using warm air Download PDFInfo
- Publication number
- WO2015097370A1 WO2015097370A1 PCT/FR2014/053410 FR2014053410W WO2015097370A1 WO 2015097370 A1 WO2015097370 A1 WO 2015097370A1 FR 2014053410 W FR2014053410 W FR 2014053410W WO 2015097370 A1 WO2015097370 A1 WO 2015097370A1
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- WO
- WIPO (PCT)
- Prior art keywords
- tread
- carcass
- envelope
- fluid
- casing
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
- B29D30/54—Retreading
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
- B29D30/54—Retreading
- B29D30/56—Retreading with prevulcanised tread
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
- B29D30/00—Producing pneumatic or solid tyres or parts thereof
- B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
- B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
- B29D30/54—Retreading
- B29D2030/544—Applying an intermediate adhesive layer, e.g. cement or cushioning element between carcass and tread
Definitions
- the invention relates to the retreading of tire casings.
- the retreading of a tire casing consists in removing the used tread from the casing and replacing it with a tread in good condition, which is generally new.
- Different heating means are possible for heating the hot melt layer. It can be a heating before assembly (by infrared for example) or after assembly, for example by conduction of contact (thermal transfer by conduction between the source of heat and the glue), by convection (one uses a fluid for transfer the heat between the heat source and the outside of the tread, then the internal conduction of the tread to heat the glue), by radiation (infrared (IR), microwave (MO), high frequency (HF)), or by induction (in the presence of conductors in the inner part of the top layer, for example). In the latter case, however, it is important that the heating is homogeneous and made under uniform pressure to make a good assembly. It is therefore necessary to use a pressure means compatible with the heating means. In the examples presented, it must not interfere with conduction, or convection, or must be transparent to infrared and electromagnetic radiation (MO, HF, IR).
- An object of the invention is to provide heating and pressurizing performance.
- a casing comprising a carcass, a tread made of baked rubber and a thermofusible bonding layer interposed between the band and the carcass are provided in a tight-walled rigid enclosure;
- a fluid is sent into the enclosure which transmits heat to the envelope and exerts on it a pressure greater than atmospheric pressure.
- the heating means is therefore, by nature, perfectly compatible with the means of setting pressure.
- the fluid is air.
- the fluid is sent outside the envelope so as to urge the tread towards the carcass.
- the fluid is sent inside the carcass so as to inflate it.
- a region between the carcass and the tread is subjected to a vacuum.
- an outer face of the envelope is covered with a membrane and the fluid is sent against the membrane.
- the membrane is clamped between flanks of the casing and walls of the enclosure extending opposite the flanks and opposite to each other.
- the fluid acts only on the side of the flanks contiguous to the tread.
- the fluid is sent against the tread.
- the casing is arranged so that walls of the enclosure opposite to each other come into contact with flanks of the casing.
- tread forms part of the sidewalls of the envelope and extends in contact with the walls.
- seals are provided in outer grooves of the tread.
- the seals reduce or eliminate the heterogeneities of pressure exerted on the tread.
- a tire casing is also provided which results from a method according to the invention.
- FIG. 1 is an axial sectional view of a press used in an embodiment of the method of the invention.
- FIGS. 1 and 2 illustrate a press 2 serving to carry out the method of the invention in the present example.
- the press comprises lower horizontal plates 4 and upper 6. These plates each form a flat wall having a general disc shape. They are coaxial with the vertical main axis 8 of the press and have internal faces planes 10 extending opposite one another.
- the press also comprises a side wall 12 forming a shell.
- This wall has a generally cylindrical shape of axis 8. Its inner face delimits with the faces 10 of the trays a closed sealed chamber 14 for receiving a tire envelope 16. For this purpose, the trays bear on their singing a seal 18 in contact with the ferrule.
- the press 2 also comprises vertical spacers 20 keeping the two plates at a distance from each other and extending each in a direction parallel to the axis 8. These spacers are removable so as to open the press to deposit an envelope in the chamber 14, and then extract it.
- Each spacer comprises in particular a cylindrical central support 22 whose axial ends bear against the respective faces 10. It also comprises screws 24 whose heads bear against the external faces of the plates, the screws passing through them and forming screw-nut connections with the support 20.
- the press also comprises means for supplying the enclosure 14 with hot air under pressure.
- These means include in particular vertical ducts 26 traversing in this case the lower plate and opening inside the enclosure. These ducts are connected to a source of hot air under pressure not shown and known in itself.
- One of these conduits comprises a pressure measuring member for regulating the pressure of the convective air flow entering the chamber.
- the press further comprises one or more ducts 27 supplying the ducts 26 with hot air and equipped with a calibrated outlet valve, here at three bars, namely 3.10 5 Pa, in addition to the atmospheric pressure, and a control valve. flow rate for regulating the inlet pressure.
- the press also comprises a core 30 in the form of a rim and used to support an envelope housed in the enclosure.
- the core has a symmetrical shape of revolution of axis 8. It comprises means 32, which have not been illustrated in detail and which can feed from the outside of the press and through the core inside. of the envelope with hot air under pressure.
- the press further comprises means for bringing into contact with a vacuum source a zone of the envelope between the carcass and the tread.
- a tire tire casing 16 which comprises a carcass 34 having a generally annular toroidal shape and a "U" shaped profile.
- the carcass comprises a crown layer 36 and two sidewalls 38.
- the envelope comprises a tread 40 extending on one side of an outer face of the crown layer 36.
- the tread has sculptures and furrows on its outer face.
- thermofusible material there is understood a material capable of softening when heated to bring it to a predetermined temperature characteristic of the material, said softening temperature.
- such a material may be selected from thermoplastic elastomers such as SBS (styrene-butadiene-styrene) or SIS (styrene-isoprene-styrene).
- SBS styrene-butadiene-styrene
- SIS styrene-isoprene-styrene
- hot melt material capable of softening at a temperature of between 140 ° and 200 °.
- the casing is covered with a membrane 42 extending against the entire outer face of the tread and projecting over most of the flanks 38.
- the casing 16 thus covered with the membrane and mounted on the core 30 as on a rim.
- the press is then closed by putting the top plate 6 back in position. As illustrated in FIG. 2, the two plates are in contact with the membrane 42 at the respective flanks without touching them directly.
- the carcass is inflated by the means 32 with hot air here at a controlled pressure of 2.5 bar, or 2.5.10 5 Pa, relative to the atmospheric pressure.
- This pressure aims in particular to allow the carcass to withstand the external pressure applied as indicated below.
- the interface between the carcass and the tread, at the level of the layer 43, is placed in contact with a source of vacuum in order to place it in depression. It is thus possible to eliminate any air bubbles. This interface is isolated from the other two zones.
- the ducts 26 are supplied with hot air at a pressure of 2.5 bar, ie 2.5 ⁇ 10 5 Pa, in order to urge the membrane and the tread towards the carcass to put the bonding layer under pressure.
- the hot air is sent continuously on the membrane and performs a convection movement. Its temperature is for example 150 ° C.
- the heat transmitted to the casing from outside and inside the carcass softens the hot melt layer.
- the internal and external pressure applies the carcass and the tread tightly against this layer.
- the supply of hot air is then interrupted, the press is opened and the shell is allowed to cool, which causes the hot-melt layer to solidify.
- the new tread is therefore closely attached to the casing of the casing.
- the membrane is deformable and that the same membrane can be used for different types of tire envelopes having different dimensions.
- this implementation mode generates an additional step, namely the step of installing the joints and requires additional products formed by them.
- this procedure is not suitable when the grooves do not extend along the circumference of the envelope, for example in the case of slatted furrows as snow tires.
- the use of the membrane is dispensed with and the hot air is pressurized directly in contact with the tread.
- the pressure is exerted evenly on the tread despite the presence of grooves and sculptures.
- the lower and upper horizontal plates are in contact with the sides of the envelope. If the tread has a diameter smaller than that of the crown layer of the carcass, the elasticity of the tread generates a pressure at the bonding layer. This pressure also makes it possible to eliminate any air bubbles present between the tread and the carcass.
- the tread forms a membrane in the sense of the membrane 42 described above.
- the retreading method described operates if the press is devoid of the membrane 42.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tyre Moulding (AREA)
Abstract
Description
Procédé de rechapage d'un pneumatique au moyen d'air chaud Method of retreading a tire with hot air
L'invention concerne le rechapage des enveloppes de pneumatique. The invention relates to the retreading of tire casings.
Le rechapage d'une enveloppe de pneumatique consiste à enlever la bande de roulement usagée de l'enveloppe pour la remplacer par une bande de roulement en bon état, généralement neuve. The retreading of a tire casing consists in removing the used tread from the casing and replacing it with a tread in good condition, which is generally new.
Il est connu à cette fin de prévoir entre la carcasse et la bande de roulement une couche de liaison thermofusible assurant l'adhérence de la bande à la carcasse et qui se ramollit lorsqu'elle est chauffée à une température prédéterminée, permettant ainsi de séparer facilement la bande de roulement de la carcasse. De même, lors de la mise en place de la nouvelle bande de roulement, on chauffe la couche thermofusible puis on la laisse refroidir pour obtenir l'adhérence de la bande à la carcasse. It is known for this purpose to provide between the carcass and the tread a hot melt bonding layer ensuring the adhesion of the band to the carcass and which softens when heated to a predetermined temperature, thus allowing to separate easily the tread of the carcass. Similarly, during the introduction of the new tread, the hot melt layer is heated and then allowed to cool to obtain the adhesion of the band to the carcass.
Différents moyens de chauffage sont possibles pour chauffer la couche thermofusible. Il peut s'agir d'un chauffage avant assemblage (par infrarouge par exemple) ou après assemblage, par exemple par conduction de contact (transfert thermique par conduction entre la source de chaleur et la colle), par convection (on utilise un fluide pour transférer la chaleur entre la source de chaleur et l'extérieur de la bande de roulement, puis la conduction en interne de la bande de roulement pour aller chauffer la colle), par rayonnement (infrarouge (IR), micro-onde (MO), haute fréquence (HF)), ou par induction (en présence de conducteurs en partie interne de la couche sommet, par exemple). Dans ce dernier cas, il importe toutefois que le chauffage soit homogène et réalisé sous pression homogène pour effectuer un bon assemblage. Il faut donc employer un moyen de pression compatible avec le moyen de chauffage. Dans les exemples présentés, il ne doit donc pas nuire à la conduction, ou à la convection, ou encore doit être transparent aux rayonnements infrarouge, et électromagnétique (MO, HF, IR). Different heating means are possible for heating the hot melt layer. It can be a heating before assembly (by infrared for example) or after assembly, for example by conduction of contact (thermal transfer by conduction between the source of heat and the glue), by convection (one uses a fluid for transfer the heat between the heat source and the outside of the tread, then the internal conduction of the tread to heat the glue), by radiation (infrared (IR), microwave (MO), high frequency (HF)), or by induction (in the presence of conductors in the inner part of the top layer, for example). In the latter case, however, it is important that the heating is homogeneous and made under uniform pressure to make a good assembly. It is therefore necessary to use a pressure means compatible with the heating means. In the examples presented, it must not interfere with conduction, or convection, or must be transparent to infrared and electromagnetic radiation (MO, HF, IR).
Un but de l'invention est d'assurer le chauffage et la mise sous pression de façon performante. An object of the invention is to provide heating and pressurizing performance.
À cet effet, on prévoit selon l'invention un procédé de rechapage d'une enveloppe de pneumatique, dans lequel : For this purpose, it is provided according to the invention a method of retreading a tire casing, in which:
- on dispose dans une enceinte étanche à parois rigides une enveloppe comprenant une carcasse, une bande de roulement en gomme cuite et une couche de liaison thermofusible interposée entre la bande et la carcasse, et a casing comprising a carcass, a tread made of baked rubber and a thermofusible bonding layer interposed between the band and the carcass are provided in a tight-walled rigid enclosure; and
- on envoie dans l'enceinte un fluide qui transmet de la chaleur à l'enveloppe et exerce sur elle une pression supérieure à la pression atmosphérique. a fluid is sent into the enclosure which transmits heat to the envelope and exerts on it a pressure greater than atmospheric pressure.
Ainsi le fluide assure à la fois la transmission de chaleur et de pression. Le moyen de chauffage est donc par nature parfaitement compatible avec le moyen de mise en pression. Thus the fluid ensures both the transmission of heat and pressure. The heating means is therefore, by nature, perfectly compatible with the means of setting pressure.
Avantageusement, le fluide est de l'air. Advantageously, the fluid is air.
De préférence, on envoie le fluide à l'extérieur de l'enveloppe de façon à solliciter la bande de roulement en direction de la carcasse. Preferably, the fluid is sent outside the envelope so as to urge the tread towards the carcass.
Ainsi la mise en pression a lieu notamment à partir de l'extérieur de l'enveloppe. Thus the pressurization takes place in particular from the outside of the envelope.
De préférence, on envoie le fluide à l'intérieur de la carcasse de façon à la gonfler.Preferably, the fluid is sent inside the carcass so as to inflate it.
Ainsi la mise en pression a lieu notamment à partir de l'intérieur de l'enveloppe.Thus the pressurization takes place in particular from the inside of the envelope.
De préférence, on soumet à une dépression une zone située entre la carcasse et la bande de roulement. Preferably, a region between the carcass and the tread is subjected to a vacuum.
Ainsi on élimine d'éventuelles bulles d'air dans cette zone. This eliminates any air bubbles in this area.
Dans un mode de réalisation, on recouvre une face externe de l'enveloppe avec une membrane et on envoie le fluide contre la membrane. In one embodiment, an outer face of the envelope is covered with a membrane and the fluid is sent against the membrane.
Avantageusement, on pince la membrane entre des flancs de l'enveloppe et des parois de l'enceinte s'étendant en regard des flancs et opposées l'une à l'autre. Advantageously, the membrane is clamped between flanks of the casing and walls of the enclosure extending opposite the flanks and opposite to each other.
Ainsi le fluide agit seulement du côté des flancs contigus à la bande de roulement. Thus, the fluid acts only on the side of the flanks contiguous to the tread.
Dans un autre mode de réalisation, on envoie le fluide contre la bande de roulement.In another embodiment, the fluid is sent against the tread.
Ainsi, on se dispense d'utiliser une membrane. Thus, one dispenses to use a membrane.
De préférence, on dispose l'enveloppe de sorte que des parois de l'enceinte opposées l'une à l'autre viennent en contact avec des flancs de l'enveloppe. Preferably, the casing is arranged so that walls of the enclosure opposite to each other come into contact with flanks of the casing.
On peut prévoir que la bande de roulement forme une partie des flancs de l'enveloppe et s'étend au contact des parois. It can be provided that the tread forms part of the sidewalls of the envelope and extends in contact with the walls.
Dans un mode de réalisation, on dispose des joints dans des sillons externes de la bande de roulement. In one embodiment, seals are provided in outer grooves of the tread.
Les joints permettent de réduire voire d'éliminer les hétérogénéités de pression s'exerçant sur la bande de roulement. The seals reduce or eliminate the heterogeneities of pressure exerted on the tread.
On prévoit également une enveloppe de pneumatique qui résulte d'un procédé selon l'invention. A tire casing is also provided which results from a method according to the invention.
Nous allons maintenant présenter plusieurs modes de mise en œuvre du procédé de l'invention en référence aux dessins annexés sur lesquels : We will now present several modes of implementation of the method of the invention with reference to the accompanying drawings in which:
- la figure 1 est une vue en coupe axiale d'une presse servant dans un mode de mise en œuvre du procédé de l'invention ; et - Figure 1 is an axial sectional view of a press used in an embodiment of the method of the invention; and
- la figure 2 et une vue à plus grande échelle d'une partie de la presse de la figure 1 . - Figure 2 and an enlarged view of a portion of the press of Figure 1.
On a illustré aux figures 1 et 2 une presse 2 servant à la mise en œuvre du procédé de l'invention dans le présent exemple. FIGS. 1 and 2 illustrate a press 2 serving to carry out the method of the invention in the present example.
La presse comprend des plateaux horizontaux inférieur 4 et supérieur 6. Ces plateaux forment chacun une paroi plane ayant une forme générale de disque. Ils sont coaxiaux avec l'axe principal vertical 8 de la presse et présentent des faces internes planes 10 s'étendant en regard l'une de l'autre. The press comprises lower horizontal plates 4 and upper 6. These plates each form a flat wall having a general disc shape. They are coaxial with the vertical main axis 8 of the press and have internal faces planes 10 extending opposite one another.
La presse comprend également une paroi latérale 12 formant une virole. Cette paroi a une forme générale cylindrique d'axe 8. Sa face interne délimite avec les faces 10 des plateaux une enceinte fermée étanche 14 servant à la réception d'une enveloppe de pneumatique 16. À cette fin, les plateaux portent sur leur chant un joint d'étanchéité 18 en contact avec la virole. The press also comprises a side wall 12 forming a shell. This wall has a generally cylindrical shape of axis 8. Its inner face delimits with the faces 10 of the trays a closed sealed chamber 14 for receiving a tire envelope 16. For this purpose, the trays bear on their singing a seal 18 in contact with the ferrule.
La presse 2 comprend également des entretoises verticales 20 maintenant les deux plateaux à distance l'un de l'autre et s'étendant chacune suivant une direction parallèle à l'axe 8. Ces entretoises sont démontables de façon à permettre d'ouvrir la presse pour déposer une enveloppe dans l'enceinte 14, puis l'en extraire. Chaque entretoise comprend en particulier un support central cylindrique 22 dont les extrémités axiales sont en appui contre les faces 10 respectives. Elle comprend également des vis 24 dont les têtes sont en appui contre les faces externes des plateaux, les vis traversant ces derniers et formant des liaisons vis-écrou avec le support 20. The press 2 also comprises vertical spacers 20 keeping the two plates at a distance from each other and extending each in a direction parallel to the axis 8. These spacers are removable so as to open the press to deposit an envelope in the chamber 14, and then extract it. Each spacer comprises in particular a cylindrical central support 22 whose axial ends bear against the respective faces 10. It also comprises screws 24 whose heads bear against the external faces of the plates, the screws passing through them and forming screw-nut connections with the support 20.
La presse comprend également des moyens pour alimenter l'enceinte 14 avec de l'air chaud sous pression. Ces moyens comprennent notamment des conduits verticaux 26 traversant en l'espèce le plateau inférieur et débouchant à l'intérieur de l'enceinte. Ces conduits sont reliés à une source d'air chaud sous pression non représentée et connue en elle-même. L'un de ces conduits comprend un organe de mesure de pression pour réguler la pression du flux d'air convectif entrant dans l'enceinte. La presse comprend en outre un ou plusieurs conduits 27 alimentant les conduits 26 en air chaud et équipé d'une soupape de sortie tarée, ici à trois bars, soit 3.105 Pa, en plus de la pression atmosphérique, et d'un limiteur de débit servant à réguler la pression d'entrée. The press also comprises means for supplying the enclosure 14 with hot air under pressure. These means include in particular vertical ducts 26 traversing in this case the lower plate and opening inside the enclosure. These ducts are connected to a source of hot air under pressure not shown and known in itself. One of these conduits comprises a pressure measuring member for regulating the pressure of the convective air flow entering the chamber. The press further comprises one or more ducts 27 supplying the ducts 26 with hot air and equipped with a calibrated outlet valve, here at three bars, namely 3.10 5 Pa, in addition to the atmospheric pressure, and a control valve. flow rate for regulating the inlet pressure.
La presse comprend également un noyau 30 ayant la forme d'une jante et servant à supporter une enveloppe logée dans l'enceinte. Le noyau a une forme à symétrie de révolution d'axe 8. Il comprend des moyens 32, qui n'ont pas été illustrés en détail et qui permettent d'alimenter depuis l'extérieur de la presse et à travers le noyau l'intérieur de l'enveloppe avec de l'air chaud sous pression. The press also comprises a core 30 in the form of a rim and used to support an envelope housed in the enclosure. The core has a symmetrical shape of revolution of axis 8. It comprises means 32, which have not been illustrated in detail and which can feed from the outside of the press and through the core inside. of the envelope with hot air under pressure.
Pour ces deux mises sous pression, on utilise en l'espèce une pression de 2,5 bars soit 2,5.105 Pa. For these two pressurizations, a pressure of 2.5 bars or 2.5 × 10 5 Pa is used in this case.
La presse comprend par ailleurs des moyens pour mettre en contact avec une source de vide une zone de l'enveloppe comprise entre la carcasse et la bande de roulement. The press further comprises means for bringing into contact with a vacuum source a zone of the envelope between the carcass and the tread.
Nous allons maintenant présenter un mode de mise en œuvre du procédé de rechapage selon l'invention au moyen de cette presse. We will now present an embodiment of the retreading process according to the invention by means of this press.
On considère une enveloppe de pneumatique de roue 16 qui comprend une carcasse 34 ayant une forme générale annulaire de tore et un profil en « U ». La carcasse comprend une couche de sommet 36 et deux flancs 38. L'enveloppe comprend une bande de roulement 40 s'étendant d'un côté d'une face externe de la couche de sommet 36. La bande de roulement présente des sculptures et des sillons sur sa face externe. Entre la carcasse et la bande de roulement est interposée une couche de liaison 43 d'un matériau thermofusible apte à se ramollir lorsqu'on le porte à une température prédéterminée. Par matériau thermofusible, on comprend un matériau apte à se ramollir lorsqu'il est chauffé pour le porter à une température prédéterminée caractéristique du matériau, dite température de ramollissement. Par exemple, un tel matériau peut être choisi parmi les élastomères thermoplastiques tels que le SBS (styrène-butadiène-styrène) ou le SIS (styrène-isoprène-styrène). Pour les besoins de l'invention, on se réfère à un matériau thermofusible capable de ramollir à une température comprise entre 140 ^ et 200 'Ό. A tire tire casing 16 is considered which comprises a carcass 34 having a generally annular toroidal shape and a "U" shaped profile. The carcass comprises a crown layer 36 and two sidewalls 38. The envelope comprises a tread 40 extending on one side of an outer face of the crown layer 36. The tread has sculptures and furrows on its outer face. Between the carcass and the tread is interposed a bonding layer 43 of a hot melt material capable of softening when worn at a predetermined temperature. By thermofusible material, there is understood a material capable of softening when heated to bring it to a predetermined temperature characteristic of the material, said softening temperature. For example, such a material may be selected from thermoplastic elastomers such as SBS (styrene-butadiene-styrene) or SIS (styrene-isoprene-styrene). For the purposes of the invention, reference is made to a hot melt material capable of softening at a temperature of between 140 ° and 200 °.
On suppose que, préalablement à la mise en œuvre du procédé, l'enveloppe a été débarrassée de sa bande de roulement usagée et que celle-ci doit être remplacée par la bande neuve 40 qui comprend notamment de la gomme cuite. Il s'agit en l'espèce d'une bande en anneau fermée qui a été installée dans une telle configuration sur la carcasse avec interposition de la couche de liaison thermofusible. It is assumed that, prior to the implementation of the method, the casing has been removed from its used tread and that it must be replaced by the new band 40 which includes cooked gum. This is a closed ring band that has been installed in such a configuration on the carcass with interposition of the hot melt bonding layer.
On recouvre l'enveloppe avec une membrane 42 s'étendant contre toute la face externe de la bande de roulement et débordant sur la plus grande partie des flancs 38. On dispose dans l'enceinte de la presse l'enveloppe 16 ainsi recouverte de la membrane et on la monte sur le noyau 30 comme sur une jante. The casing is covered with a membrane 42 extending against the entire outer face of the tread and projecting over most of the flanks 38. The casing 16 thus covered with the membrane and mounted on the core 30 as on a rim.
On referme ensuite la presse en remettant en place le plateau supérieur 6. Comme illustré à la figure 2, les deux plateaux sont en contact avec la membrane 42 au niveau des flancs respectifs sans toucher ceux-ci directement. The press is then closed by putting the top plate 6 back in position. As illustrated in FIG. 2, the two plates are in contact with the membrane 42 at the respective flanks without touching them directly.
Ensuite, on gonfle la carcasse grâce aux moyens 32 avec de l'air chaud ici à une pression régulée de 2,5 bar, soit 2,5.105 Pa, en relatif par rapport à la pression atmosphérique. Cette pression vise notamment à permettre à la carcasse de résister à la pression externe appliquée comme indiqué ci-après. Then, the carcass is inflated by the means 32 with hot air here at a controlled pressure of 2.5 bar, or 2.5.10 5 Pa, relative to the atmospheric pressure. This pressure aims in particular to allow the carcass to withstand the external pressure applied as indicated below.
On met l'interface entre la carcasse et la bande de roulement, au niveau de la couche 43, en contact avec une source de vide afin de la placer en dépression. On peut ainsi éliminer d'éventuelles bulles d'air. Cette interface est isolée des deux autres zones. The interface between the carcass and the tread, at the level of the layer 43, is placed in contact with a source of vacuum in order to place it in depression. It is thus possible to eliminate any air bubbles. This interface is isolated from the other two zones.
Par ailleurs on alimente les conduits 26 avec de l'air chaud à une pression de 2,5 bar, soit 2,5.105 Pa, afin de solliciter la membrane et la bande de roulement en direction de la carcasse pour mettre la couche de liaison sous pression. Furthermore, the ducts 26 are supplied with hot air at a pressure of 2.5 bar, ie 2.5 × 10 5 Pa, in order to urge the membrane and the tread towards the carcass to put the bonding layer under pressure.
Il existe donc trois zones de pression différentes. Grâce au gonflage de la carcasse, l'enveloppe est pincée au niveau des flancs entre les deux plateaux. La pression appliquée sur la membrane ne s'étend donc pas de l'autre côté des flancs, au-delà de cette zone de pincement. There are therefore three different pressure zones. Thanks to the inflation of the carcass, the envelope is pinched at the flanks between the two plates. The pressure applied to the membrane therefore does not extend to the other side of the flanks, beyond this pinching zone.
L'air chaud est envoyé en continu sur la membrane et réalise un mouvement de convection. Sa température est par exemple de 150°C. La chaleur transmise à l'enveloppe depuis l'extérieur et l'intérieur de la carcasse ramollit la couche thermofusible. La pression interne et externe applique la carcasse et la bande de roulement étroitement contre cette couche. The hot air is sent continuously on the membrane and performs a convection movement. Its temperature is for example 150 ° C. The heat transmitted to the casing from outside and inside the carcass softens the hot melt layer. The internal and external pressure applies the carcass and the tread tightly against this layer.
On interrompt ensuite l'alimentation en air chaud, on ouvre la presse et on laisse refroidir l'enveloppe, ce qui entraîne la solidification de la couche thermofusible. La nouvelle bande de roulement est donc étroitement fixée à la carcasse de l'enveloppe. The supply of hot air is then interrupted, the press is opened and the shell is allowed to cool, which causes the hot-melt layer to solidify. The new tread is therefore closely attached to the casing of the casing.
On observe que la membrane est déformable et que cette même membrane peut être utilisée pour différents types d'enveloppes de pneumatique ayant des dimensions différentes. It is observed that the membrane is deformable and that the same membrane can be used for different types of tire envelopes having different dimensions.
D'autres modes de mise en œuvre du procédé de l'invention sont envisageables. Other modes of implementation of the method of the invention are conceivable.
Dans le mode de mise en œuvre décrit plus haut, on risque de voir survenir des hétérogénéités de pression au niveau des sillons et des sculptures de la bande de roulement. Pour y pallier, avant la mise en place de la membrane, on peut disposer des joints toriques à l'intérieur des sillons. In the implementation mode described above, there is a risk of occurrence of pressure heterogeneities in the grooves and tread patterns. To overcome this, before the introduction of the membrane, we can have O-rings inside the grooves.
Toutefois, ce mode de mise en œuvre engendre une étape supplémentaire, à savoir l'étape d'installation des joints et nécessite des produits supplémentaires constitués par ces derniers. De plus, cette façon de faire ne convient pas lorsque les sillons ne s'étendent pas suivant la circonférence de l'enveloppe, par exemple lorsqu'il s'agit de sillons en forme de lamelles comme sur les pneus neige. However, this implementation mode generates an additional step, namely the step of installing the joints and requires additional products formed by them. In addition, this procedure is not suitable when the grooves do not extend along the circumference of the envelope, for example in the case of slatted furrows as snow tires.
C'est pourquoi, dans un autre mode de mise en œuvre, on se dispense d'utiliser la membrane et on met l'air chaud sous pression directement au contact de la bande de roulement. Ainsi, la pression s'exerce de façon homogène sur la bande de roulement en dépit de la présence des sillons et des sculptures. Cela suppose de garantir que la bande de roulement n'est pas percée. Selon ce mode de mise en œuvre, les plateaux horizontaux inférieur et supérieur sont en contact avec les flancs de l'enveloppe. Si la bande de roulement présente un diamètre inférieur à celui de la couche de sommet de la carcasse, l'élasticité de la bande de roulement engendre une pression au niveau de la couche de liaison. Cette pression permet par ailleurs d'éliminer d'éventuelles bulles d'air présentes entre la bande de roulement et la carcasse. En d'autres termes, la bande de roulement forme une membrane au sens de la membrane 42 décrite précédemment. On comprend ainsi que le procédé de rechapage décrit fonctionne si la presse est dépourvue de la membrane 42. De plus, il est préférable de doter la bande de roulement de pattes qui recouvrent latéralement une partie des flancs respectifs afin que le contact entre les plateaux et l'enveloppe s'effectue au niveau de ces pattes, là où il s'effectuait avec la membrane dans le premier mode de mise en œuvre. This is why, in another embodiment, the use of the membrane is dispensed with and the hot air is pressurized directly in contact with the tread. Thus, the pressure is exerted evenly on the tread despite the presence of grooves and sculptures. This assumes to guarantee that the tread is not pierced. According to this mode of implementation, the lower and upper horizontal plates are in contact with the sides of the envelope. If the tread has a diameter smaller than that of the crown layer of the carcass, the elasticity of the tread generates a pressure at the bonding layer. This pressure also makes it possible to eliminate any air bubbles present between the tread and the carcass. In other words, the tread forms a membrane in the sense of the membrane 42 described above. It is thus understood that the retreading method described operates if the press is devoid of the membrane 42. In addition, it is preferable to provide the tread with tabs that laterally cover a portion of the respective flanks so that the contact between the trays and the envelope is effected at these legs, where it was carried out with the membrane in the first mode of implementation.
Bien entendu, on pourra apporter à l'invention de nombreuses modifications sans sortir du cadre de celle-ci. Of course, we can bring to the invention many changes without departing from the scope thereof.
Claims
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR1363439A FR3015349B1 (en) | 2013-12-23 | 2013-12-23 | METHOD FOR RETRIEVING A TIRE BY MEANS OF HOT AIR |
| FR1363439 | 2013-12-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2015097370A1 true WO2015097370A1 (en) | 2015-07-02 |
Family
ID=50179833
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/FR2014/053410 Ceased WO2015097370A1 (en) | 2013-12-23 | 2014-12-18 | Method for retreading a tyre using warm air |
Country Status (2)
| Country | Link |
|---|---|
| FR (1) | FR3015349B1 (en) |
| WO (1) | WO2015097370A1 (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3809592A (en) * | 1972-04-04 | 1974-05-07 | Denbilt Corp | Process and apparatus for retreading tires |
| US3886028A (en) * | 1973-06-14 | 1975-05-27 | Oliver Tire & Rubber Co | Apparatus for recapping tires with precured tread rubber |
| US3895985A (en) * | 1972-04-11 | 1975-07-22 | Wilhelm Schelkmann | Method of repairing tires and shells used for this method |
| US3935045A (en) * | 1973-10-26 | 1976-01-27 | The Goodyear Tire & Rubber Company | Method of retreading a tire |
| US4046947A (en) * | 1974-02-04 | 1977-09-06 | Bandag Incorporation | Material and methods for bonding treads to tires |
| US4111732A (en) * | 1974-03-22 | 1978-09-05 | Macmillan Kenneth T | Process of and molds for applying precured rubber tires and other objects |
| GB2091173A (en) * | 1981-01-14 | 1982-07-28 | Michelin & Cie | Apparatus for heating pneumatic tyre assemblies under pressure |
| US5055148A (en) * | 1989-05-26 | 1991-10-08 | The Goodyear Tire & Rubber Company | Method for retreading tires |
| US20110056603A1 (en) * | 2008-05-16 | 2011-03-10 | The Yokohama Rubber Co., Ltd. | Pneumatic radial tire and process for producing retreaded tire |
| FR2988644A1 (en) * | 2012-04-02 | 2013-10-04 | Michelin & Cie | METHOD FOR RECHAMING A TIRE WHOSE TOP ZONE IS PROVIDED WITH A SUB-LAYER COMPRISING A THERMOPLASTIC ELASTOMER |
-
2013
- 2013-12-23 FR FR1363439A patent/FR3015349B1/en not_active Expired - Fee Related
-
2014
- 2014-12-18 WO PCT/FR2014/053410 patent/WO2015097370A1/en not_active Ceased
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3809592A (en) * | 1972-04-04 | 1974-05-07 | Denbilt Corp | Process and apparatus for retreading tires |
| US3895985A (en) * | 1972-04-11 | 1975-07-22 | Wilhelm Schelkmann | Method of repairing tires and shells used for this method |
| US3886028A (en) * | 1973-06-14 | 1975-05-27 | Oliver Tire & Rubber Co | Apparatus for recapping tires with precured tread rubber |
| US3935045A (en) * | 1973-10-26 | 1976-01-27 | The Goodyear Tire & Rubber Company | Method of retreading a tire |
| US4046947A (en) * | 1974-02-04 | 1977-09-06 | Bandag Incorporation | Material and methods for bonding treads to tires |
| US4111732A (en) * | 1974-03-22 | 1978-09-05 | Macmillan Kenneth T | Process of and molds for applying precured rubber tires and other objects |
| GB2091173A (en) * | 1981-01-14 | 1982-07-28 | Michelin & Cie | Apparatus for heating pneumatic tyre assemblies under pressure |
| US5055148A (en) * | 1989-05-26 | 1991-10-08 | The Goodyear Tire & Rubber Company | Method for retreading tires |
| US20110056603A1 (en) * | 2008-05-16 | 2011-03-10 | The Yokohama Rubber Co., Ltd. | Pneumatic radial tire and process for producing retreaded tire |
| FR2988644A1 (en) * | 2012-04-02 | 2013-10-04 | Michelin & Cie | METHOD FOR RECHAMING A TIRE WHOSE TOP ZONE IS PROVIDED WITH A SUB-LAYER COMPRISING A THERMOPLASTIC ELASTOMER |
Also Published As
| Publication number | Publication date |
|---|---|
| FR3015349A1 (en) | 2015-06-26 |
| FR3015349B1 (en) | 2016-08-05 |
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