RU2457949C1 - Method and device for assembly of automotive tire - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to assembling of tires. Device for tire assembly. Note here that tires represent two different types. Proposed device comprises tire assembly line including multiple work stations arranged to comply with ordered sequence. Note here that every work station allows assembling structural element of the tire. It comprises also tire handler arranged on supports coupled with every work station. It comprises also transfer device to transfer tire from any first work station of said ordered sequence to any second work station not adjoining the former so that tire is carried from first work station to second work station bypassing any work station arranged there between. Invention covers also method of producing tires and selecting tire assembly work station.

EFFECT: higher process flexibility and efficiency.

1 dwg

Description

The present invention relates to a method for assembling tires for vehicle wheels.

The present invention also relates to an assembly for assembling tires for vehicle wheels, which can be used to implement the above assembly method.

A tire manufacturing cycle includes an assembly process in which various elements of the tire itself are manufactured and / or assembled on one or more assembly lines, and then a molding and vulcanization process is carried out in an appropriate vulcanization line adapted to form the tire structure in accordance with the desired geometry and tread pattern .

A tire usually comprises a carcass of a toroidal shape, including one or more carcass layers reinforced with reinforcing cords located in so-called "radial" tires, in substantially radial planes (the radial plane contains the axis of rotation of the tire). Each layer of the carcass contains its ends, connected integrally with at least one metal reinforcing ring-shaped structure, known as a bead core, forming a bead hardening, i.e. in the radially inner ends of the tire, which performs the function of ensuring the assembly of the tire with the corresponding mounting rim. A ring of elastomeric material, called a tread band, is placed on said frame in the form of a crown, in which, at the end of the molding and vulcanization stages, a convex pattern is formed for contact with the ground. A reinforcing structure, commonly referred to as a bracelet, is placed between the frame and the tread band. Such a bracelet usually contains, in the case of car tires, at least two radially superimposed layers of rubberized fabric containing reinforcing cords, usually of metallic material, parallel to each other in each layer and intersecting with the cords of the adjacent layer, preferably symmetrically placed relative to the equatorial plane of the tire. Preferably, the belt bracelet further comprises, in its radially outer position, at least at the ends of the underlying belt layers, also a third layer of textile or metal cords arranged in a circumferential direction (at an angle of 0 °).

The belt bracelet and the tread band together form the so-called “belt tread band” of the tire.

Finally, tubeless tires have a radially inner layer, called a hermetic layer, which has airtight properties to ensure the airtightness of the tire itself.

In relation to the present invention and in the following claims, the term "elastomeric material" refers to a composition containing at least one elastomeric polymer and at least one reinforcing filler. Preferably, such a composition also contains additives, such as crosslinking and / or plasticizing agents. Thanks to crosslinking agents, such a material can be crosslinked by heating to form the final finished product.

In this case, the term "uncured tire" means a tire obtained as a result of the assembly process, but not yet vulcanized and molded.

As already noted, in the so-called "radial" tires, each of the cords located in the layer or layers of the carcass is in a plane essentially radial with respect to the axis of rotation of the tire, that is, it has an orientation substantially orthogonal to the circumferential direction. Conversely, in so-called "diagonal" tires, the carcass usually contains at least one first carcass ply containing cords angled relative to the tire circumferential direction, and a second carcass ply whose cords are oblique and symmetrically cross with respect to the cords of the first layer.

Compared to tires for four-wheeled vehicles, tires for two-wheeled vehicles must have very special characteristics that imply some structural features. The most important features are a consequence of the fact that on a bend the motorcycle should tilt significantly relative to the position that it has when driving on a straight road, forming an angle with a perpendicular to the ground (called the angle of heel), which usually reaches 45 °, but which in extreme conditions Driving can reach 65 °. Thus, when the motorcycle bends, the tire contact area is gradually shifted from the central zone of the tread band to the axially outermost zone in the direction of the bend center. Therefore, tires for two-wheeled vehicles are characterized by strong lateral bending. Such lateral bending is usually determined by the specific value of the deflection ratio R between the distance between the radially outer portion of the tread and the line passing through the transversely opposite ends of the tread band itself, measured in the equatorial plane of the tire, and the distance measured between the said ends along the tire chord. Compared to tires for automobiles in which the deflection ratio R is usually about 0.05, in tires for two-wheeled vehicles, the deflection ratio R is usually not less than 0.15 and is usually about 0.3 in the case of rear tires, and even higher, comes to about 0.45, in the case of front tires.

Currently, tires for two-wheeled vehicles typically comprise a radial carcass connected to the belt bracelet, which may contain one or more layers of belt, made in the form of a closed ring, essentially consisting of textile or metal cords, suitably oriented relative to the cords contained in adjacent frame.

In particular, a bracelet can be made by means of one or more continuous cords wound in accordance with axially adjacent rings and substantially parallel to the circumferential direction of the tire itself (the so-called “belt at an angle of 0 °”). Alternatively, the belt bracelet may consist of two radially overlapping layers, each consisting of an elastomeric material reinforced with cords arranged parallel to each other, said layers being arranged so that the cords of the first layer of the belt are oriented at an angle relative to the equatorial plane of the tire and the cords of the second layers also have an inclined orientation, but symmetrically cross with respect to the cords of the first layer (the so-called "cross breaker").

Thus, tires for vehicles, and in particular tires for two-wheeled vehicles, can be of various types. This implies a significant complication in terms of aggregates and tire assembly processes.

WO 01/32409 describes a tire assembly line comprising workstations configured to manufacture and assemble at least one structural element of a tire to be processed, in which at least one series of tires is simultaneously processed and in which the tire is transferred to the vulcanization line is carried out by means of mechanical hands and in accordance with the transfer speed equal to the transfer speed of the tires to each of the mentioned workstations.

Publication WO 01/39963 describes a method for manufacturing tires that are different from each other, comprising an assembly unit comprising a plurality of workstations adapted to assemble at least one structural element on at least one type of tire to be processed, a vulcanization unit and a device for transferring and moving the processed tire, operating between workstations and a vulcanization unit.

EP 1481791 A2 describes a method for the simultaneous manufacture of tires, the tires being selected from a group of tires with different assembly specifications with different sizes. This method includes the steps of: selecting equipment for assembling the tires and materials required for the manufacture of the appropriate type of tire; calculating the appropriate number of cycles that each assembly equipment must carry out in order to assemble a given batch; and automatically switching to another assembly specification when a batch changes, by switching to another assembly specification after passing the last bus of the first assembly specification; repeating the automatic transition to the next assembly specification at each station when each last bus of each previous batch passes until the last batch is manufactured. The manufacturing system comprises at least four frame assembly stations, each station being located at a predetermined distance, and preferably a bracelet assembly line comprising workstations separate from the frame assembly line, the frames and bracelets being connected in a segmented, self-locking form.

Methods of this type described in WO 01/32409 and WO 01/39963 are intended to increase productivity in the manufacturing processes of tires assembled on a toroidal forming support and to use basic semi-finished products for assembly by means of automated standardized steps synchronized with each other. However, such processes do not allow achieving high technological flexibility, that is, the possibility of using basic semi-finished products for each tire that differ in the type of elastomeric material or the type of textile or metal reinforcing cord. In fact, such methods are suitable for the manufacture of tires that differ in limited ways, such as sizes, the optional presence of some structural elements of the tire, such as one or two layers of the carcass, reinforcing elements in the bead area, the placement of rings of rubber wire forming the bead cores in the bead area , more or less elongated belt layer at an angle of 0 °, the presence of a layer and a lower layer in the tread band.

This problem is even more pronounced in the case of tire assembly for two-wheeled vehicles. In this case, in fact, in most cases the same vehicle requires tires of different models, so the possibility of achieving appropriate technological flexibility becomes fundamental.

The method described in EP 1481791 is technologically flexible, because it allows you to get tires using semi-finished products containing different elements that are different from each other, but it is limited in performance, for example, when the model of the manufactured tire changes, and requires large-sized devices to move them.

In addition, in the production systems of this latter type, the management of a large number of materials and / or semi-finished products causes problems in synchronizing the manufacturing steps of the various elements making up the tire, and thus problems in the overall management of the production system with negative effects on productivity.

Finally, in all units described in the aforementioned documents, in the event of failure of one workstation, the entire assembly unit must be stopped with obvious negative consequences in this case.

In the present description and the following formula, the term “ordered sequence” of workstations means a plurality of at least three workstations arranged in accordance with a predetermined assembly sequence, each workstation between the first and last being adjacent to two different workstations , the previous and subsequent station, and the first workstation of the said set is located next to and in front of the second workstation of the said set, and the last workstation mention The set is located next to and after the penultimate workstation of the set.

Thus, sequential and adjacent workstations and serial and non-adjacent stations are in an ordered sequence.

Naturally, if there are three workstations, then the second and penultimate workstation coincide.

In this description, in the following claims, the term "base element" means a basic semi-finished product in the form of: a continuous elongated element of elastomeric material; rubber-metal or textile reinforcing cord, i.e. coated with elastomeric material; a tape-shaped element of elastomeric material, cut to size, containing at least two textile or metal cords, hereinafter referred to as the "strip element".

In the present description and in the following claims, the term "structural element" of a tire means any part of the tire suitable for performing a function or part thereof. Thus, structural elements are, for example, a hermetic layer, a lower hermetic layer, a wear-resistant element, a bead core, a bead filler, a carcass layer, a belt of a breaker, a lower layer of a belt, a lower layer of a tread band, side panels, side panels, a tread band, reinforcing inserts.

In this description and in the following claims, the term “model” of a tire means a set of geometric elements (such as, for example, the width of the tread band, side height, diameter of the connecting element), structural elements (such as, for example, a single or double layer structure radial or with intersecting layers of the frame, with or without a belt bracelet, type of belt bracelet - with crossing belts, angles 0 °, crossing belts and angles 0 °, - type of tread band with one or more layers s et al.) and technological elements (such as the compound of various structural elements, the material forming the textile or metallic reinforcing cords, the reinforcing cords formation type, and others.).

Thus, the applicant found that for assembling tires with very different technological requirements, eliminating downtime of the entire unit, increasing the flexibility and even productivity of processes, such as the processes described in WO 01/32409 and in WO 01/39963, eliminating production units having large overall dimensions and difficult to control and synchronize, such as the units described in EP 1481791 A2, it is necessary to create an assembly unit containing at least one device adapted to transfer the processed tire from any Static preparation station assembly line to any other workstation of the assembly line.

Thus, in the presence of at least one tire assembly line for vehicle wheels on forming supports comprising a plurality of workstations in an ordered sequence, each associated with at least one device for handling the processed tires, and at least one transfer device adapted to transfer the bus being processed from any workstation of said ordered sequence to any other non-adjacent work station of said ordered sequence flats, it is possible to produce simultaneously batches of tires with high differentiation and technological complexity, ensuring high productivity and quality of the finished product.

Finally, in the process of assembling tires of different models on the corresponding forming supports, collecting many structural elements on a plurality of workstations arranged in an ordered sequence, which provides for at least one step of transferring the machined tire from one workstation to a non-adjacent workstation station, you can get tires with high technological flexibility, also increasing productivity.

In other words, eliminating the sequential passage of processed tires across all workstations of the assembly line, moving from one workstation to a nearby workstation and applying logic for selecting and transferring tires, depending on the technological requirements for the bus being assembled and on the availability of workstations, to increase both the flexibility and productivity of the known processes and assemblies for assembling different tires, as well as eliminate the downtime of the entire assembly in the event of failure of one workstation.

More specifically, in accordance with its first aspect, the invention relates to a method for selecting workstations in a tire assembly line for vehicle wheels, the tires being tires of at least two different models, the assembly line comprising a plurality of workstations located in in accordance with an ordered sequence, and each workstation is configured to assemble at least one structural element of each bus, the method includes the step of:

ii) selecting at least two non-adjacent workstations to which the worktable is transferred based on the model of the bus, the structural element to be assembled and the workstations themselves, the transfer being carried out in such a way that the workable bus moves only in the aforementioned at least two workstations.

In accordance with its second aspect, the invention relates to a method for manufacturing tires for vehicle wheels, the tires being tires of at least two different models, comprising the steps of:

b) assembling at least the first and second tire model on the respective forming supports by assembling each structural element on a plurality of workstations arranged in accordance with an ordered sequence in the tire assembly line, wherein the processed tires on the respective forming supports are transferred from one working stations to another by means of a transfer device;

moreover, step b) of assembling at least the first and second model of the tire includes at least one step c) transferring the machined tire on its own forming support from the first workstation of the assembly line to a second non-adjacent workstation in the aforementioned ordered sequence;

in this case, each step c) of the transfer occurs in such a way that the processed tire on its forming support moves only in the aforementioned first and second workstation.

Since the method in accordance with the invention is compatible with the use of basic semi-finished products that are different for each tire produced, this eliminates the above-mentioned disadvantages of reduced technological flexibility and / or productivity, ensuring high performance of the finished product.

Thus, the process in accordance with the present invention is technologically flexible and efficient. In fact, it was confirmed that with a method of this type, productivity increases by at least about 50% for each assembly line if the required flexibility is maximum, and by a maximum of about 80% for each assembly line if the required flexibility is limited.

In accordance with its third aspect, the invention relates to an assembly for assembling tires for vehicle wheels, the tires being tires of at least two different models, comprising at least one tire assembly line, which in turn comprises:

a plurality of workstations arranged in accordance with an ordered sequence, each workstation being configured to assemble at least one structural element of each bus;

at least one manipulation device for the processed tires on the respective forming supports associated with each workstation; and,

at least one transfer device adapted to transfer the work tire on its forming support from any first workstation of said ordered sequence to any other second non-adjacent work station of said ordered sequence, so that the processed tire on its forming support only moves in the aforementioned first and second workstation.

Said unit implementing said method provides the aforementioned advantages.

Since the assembly unit contains a device for transferring the bus to be processed from any workstation of the ordered sequence to any other non-adjacent work station of this ordered sequence, this also eliminates the aforementioned disadvantages associated with the need to stop the unit in case of failure of one work station .

Finally, eliminating the use of manipulation devices associated with individual workstations, also for transferring tires from one workstation to another, and allocating a special transfer device to perform such an operation, it is also possible to optimize the cycle time of different workstations and increase the productivity of the assembly unit.

The present invention, in at least one of its aspects mentioned, may have at least one of the following preferred features.

Said step of selecting at least two workstations is preferably preceded by a step of receiving information about the assembled bus model and the availability of workstations. Thus, it is possible to process such information and select the most suitable workstations in order to optimize production costs and production time.

Preferably, step b) of the assembly is preceded by step:

a) placing a plurality of basic elements of assembled tires on said plurality of workstations.

Preferably, the assembly step b) includes, before the transfer step c), the step:

d) the choice of the workstation to which the bus being processed is transferred based on the bus model, the assembled structural element and the availability of the workstations themselves.

This provides a comprehensive assessment of the situation during tire assembly and, thus, the selection of the most suitable workstations.

Preferably, assembly step b) is carried out by transferring the work tire on its forming support from one work station to the next work station of said ordered sequence. In other words, this method of assembling tires provides the transfer of the processed tire in one direction of movement of the ordered sequence. Thus, the tire is prevented from moving the tire back and forth in said ordered sequence with disadvantages in terms of processing and control time.

According to a preferred embodiment, said assembly step b) comprises the steps of:

i) assembly of the frame, and the frame contains at least one layer of the frame and a pair of annular fixing structures;

ii) assembling a belt bracelet, wherein the belt bracelet comprises at least one layer of belt; and

iii) the assembly of the tread band.

Preferably, in at least one assembled tire model, the deflection ratio R between the distance between the radially outer portion of the tread band and the line passing through the transversely opposite ends of the tread band itself, measured in the equatorial plane of the tire, and the distance measured between the said ends along the chord tires greater than or equal to about 0.15. Thus, it is possible to obtain tires for two-wheeled vehicles.

According to preferred embodiments, said deflection ratio R is less than or equal to about 0.3. Thus, it is possible to obtain rear tires of two-wheeled vehicles.

According to other preferred embodiments, said deflection ratio R is less than or equal to about 0.45. Thus, it is possible to obtain front tires of two-wheeled vehicles.

Preferably, in step ii), at least one layer of the breaker is a layer of textile or metal cords in the circumferential direction at an angle of 0 °.

Preferably, step iii) of assembling the tread band includes a step iii ') of applying the tread band in a position radially external to the belt band.

Preferably, step iv) is provided for applying at least a portion of the sidewalls of the tire to be machined in a position axially external to the tire being machined.

Step iii) of assembling the tread band may include, before step iii ′) of applying the tread band, step iii ″) of applying at least one lower layer of the tread band in a position radially external to the belt band.

Preferably, at least one of steps iii ′), iii ″) or iv) is performed by applying at least one continuous elongated element of elastomeric material in accordance with adjacent or at least partially overlapping rings.

Preferably, at least one structural element is assembled by assembling at least one base element.

A method of manufacturing tires may further include a preliminary step of supplying the basic elements to at least one workstation.

Preferably, the forming support is a toroidal support.

Preferably, the toroidal support comprises a radially outer surface corresponding to the radially inner surface of the tire being machined.

According to preferred embodiments, the first and second tire models differ in size.

According to other preferred embodiments, the first and second tire models differ in structural elements.

According to other preferred embodiments, the first and second tire models differ in the basis elements used.

Preferably, the plurality of workstations comprises:

at least one frame assembly workstation, the frame comprising at least one layer of the frame and a pair of annular fixing structures;

at least one belt bracelet assembly workstation, wherein the belt bracelet comprises at least one belt layer; and

at least one tread band bracelet workstation.

Preferably, the tire assembly comprises two carcass assembly workstations.

Preferably, the first carcass assembly workstation is configured to assemble the carcass different from the carcass assembled by the second carcass assembly workstation.

In accordance with a preferred embodiment of the assembly unit, each frame assembly workstation comprises at least:

one layer overlay node and

overlay core assembly.

Preferably, at least one workstation is configured to assemble at least one structural element of each tire by assembling at least one base element.

Preferably, the overlay core application unit comprises at least one device including a dispenser of a continuous elongated element made in the form of a rubber reinforcing cord.

Even more preferably, at least one drive is connected to a manipulation device associated with the frame assembly workstation for moving the forming support with the possibility of applying a continuous elongated element in accordance with radially overlapping rings.

Preferably, the belt bracelet assembly workstation comprises a sub-belt layer overlay unit including devices for applying a sub-belt layer in a position radially external to said frame.

Preferably, the belt bracelet assembly workstation comprises at least one belt layer overlay assembly including devices for applying at least the first belt layer in a position radially external to said frame.

Preferably, two such breaker layer overlay assemblies are provided.

Preferably, at least two workstations for assembling the belt bracelet are provided.

Preferably, the first belt bracelet assembly workstation is configured to superimpose at least two radially overlapping belt layers, the layers being arranged so that the cords of the first belt layer are oriented at an angle relative to the equatorial plane of the tire being processed, and the cords of the second layer also have an inclined angle orientation, but symmetrically cross relative to the cords of the first layer.

Preferably, the second belt bracelet assembly workstation is configured to apply at least one layer of belt, which is a layer of textile or metal cords, oriented in the circumferential direction at an angle of 0 °.

According to an embodiment of the assembly, the tread band assembly workstation comprises at least one tread band bracelet overlay assembly.

Preferably, two tread band bracelet overlay assemblies are provided.

Preferably, the assembly further comprises at least one sidewall assembly workstation including a sidewall overlay assembly for assembling at least a portion of the sidewall in a position axially external to the tire being machined.

Preferably, the assembly further comprises at least one overlay assembly for the lower layer of the tread band, including devices for applying at least one lower layer of the tread band.

Such an assembly is preferably located in the tread band assembly workstation.

The tire assembly may further comprise a pressurization overlay workstation including a pressurize overlay assembly.

The tire assembly may further comprise at least one feed unit for the base elements.

In accordance with preferred embodiments, at least one of the workstations comprises at least one device including a dispenser for a continuous elongated member of elastomeric material.

Even more preferably, at least one drive is connected to a manipulation device associated with the workstation to move the forming support with the possibility of applying a continuous elongated element in accordance with adjacent or at least partially overlapping rings.

Optionally, the assembly unit may include the stage of preparation of basic elements adapted for supply to at least one workstation.

Preferably, the transfer device adapted to transfer the work tire on its forming support from one work station to another work station of said ordered sequence comprises at least one mechanical manipulator or mechanical arm.

In addition, the transfer device is preferably arranged to move along the guide.

Preferably, the handling device for the machined tires on the respective forming supports comprises at least one mechanical arm.

Other features and advantages of the invention will become apparent from the following description of some preferred examples of methods for selecting workstations, methods for manufacturing tires and assemblies for assembling tires in accordance with the invention, presented as an illustrative non-limiting example with reference to the accompanying drawing, in which:

figure 1 is a diagram of an assembly for assembling tires for vehicle wheels in which a method for selecting workstations and a method for manufacturing tires in accordance with an embodiment of the present invention are implemented.

In the drawing, reference numeral 1 denotes the assembly line of the tire assembly unit for vehicle wheels in accordance with the present invention. At the same time, tires are assembled in at least two different models. Such models may differ in size, structural elements and / or basic elements.

The assembly line 1 of the assembly comprises a plurality of workstations 4, 4 ', 5, 5', 6, 12, 14, each of which is configured to assemble at least one structural element of each tire by assembling at least one base element. Workstations 4, 4 ', 5, 5', 6, 12, 14 are arranged according to an ordered sequence, in accordance with the above definition.

The assembly line 1 further comprises at least one manipulation device 3 for tires machined on the respective forming supports associated with each workstation 4, 4 ', 5, 5', 6, 12, 14. Each manipulation device is configured to interaction with the corresponding workstation 4, 4 ', 5, 5', 6, 12, 14 to assemble the basic elements.

The assembly line 1 also comprises at least one transfer device 2, which is adapted to transfer the work tire on its forming support from any first work station of an ordered sequence to any other second work station not adjacent to the first station, so that the work bus on its forming support it moves only in the first and second workstations along the transfer path.

The transfer path is the path along which the forming support 2 moves, and can be of any type (rectangular, zigzag, etc.). If the transfer is carried out from one workstation 4, 4 ', 5, 5', 6, 12, 14 to the next and non-adjacent workstation, then the transfer path usually differs from the path along which the transfer support 2 moves when moving from one the workstation 4, 4 ', 5, 5', 6, 12, 14 to the workstation 4, 4 ', 5, 5', 6, 12, 14 adjacent to and following it in said ordered sequence.

In particular, many workstations 4, 4 ', 5, 5', 6, 12, 14 contain:

at least one frame assembly workstation 4, 4 ′;

at least one workstation 5, 5 ′ of the belt bracelet assembly; and,

at least one tread band bracelet workstation 6;

moreover, the frame contains at least one layer of the frame and a pair of annular fixing structures, and the belt bracelet contains at least one layer of the belt.

As shown in the drawing, two first carcass assembly workstations 4, 4 ′ are provided, the first carcass assembly workstation 4 being configured to assemble the carcass, which may differ from the carcass assembled by the second carcass assembly workstation 4 ′. Alternatively, the first carcass assembly workstation 4 and the second carcass assembly workstation 4 'can assemble the same carcass on a corresponding forming drum, for example, in the case of double-layer tires.

Each frame assembly workstation 4, 4 ′ comprises a layer overlay unit 7 and a bead core application unit 8.

The bead core superimposing unit 8 preferably comprises a device including a dispenser of a continuous elongated element made in the form of a rubber reinforcing cord, the actuators being preferably connected to each manipulation device 3 associated with the frame assembly workstation 4, 4 ′, moving the forming support with the possibility of winding a continuous elongated element in accordance with preferably radially overlapping rings for the manufacture of annular fixing structure R.

In the embodiment shown in the drawing, the two mentioned workstations 5, 5 'of the assembly of the belt bracelet are provided (of which only one is shown in detail in FIG. 1). Each of them contains a sub-breaker layer overlay unit 9, comprising devices for applying the sub-breaker layer in a position radially external to said frame.

Each belt bracelet assembly workstation 5, 5 ′ further comprises at least one belt layer overlay assembly 10 including devices for applying at least the first belt layer in a position radially external to said frame.

The first belt bracelet assembly workstation 5 is preferably configured to overlap at least two radially overlapping belt layers, the layers being arranged so that the cords of the first belt layer are oriented at an angle relative to the equatorial plane of the tire being processed, and the cords of the second layer also have an inclined orientation, but symmetrically cross with respect to the cords of the first layer.

The second workstation 5 'of the assembly of the belt bracelet of the tire assembly shown in the drawing comprises two belt layering units 10.

Preferably, the second belt bracelet assembly station 5 ′ is configured to overlay at least one layer of the belt, which is a layer of textile or metal cords oriented in the circumferential direction at an angle of 0 °.

The tread band assembly workstation 6 of the assembly line 1 comprises at least one tread band bracelet overlay unit 11.

In the embodiment shown in the drawing, the tread band assembly workstation 6 comprises two tread band wrist overlay assemblies 11 and one tread band wrist overlay assembly 13. The latter includes devices for applying at least one lower layer of the tread band.

However, such a node 13 for applying the lower layer of the tread band can be located outside the workstation 6 of the tread band assembly in a special assembly work station.

The assembly unit 1 further comprises at least one sidewall assembly workstation 12 comprising a sidewall overlay assembly 17 for assembling at least a portion of the sidewall in a position axially external to the tire being machined.

The assembly unit 1, shown in figure 1, further comprises a workstation for applying the hermetic layer 14, containing a node 18 for applying the hermetic layer.

The assembly line 1 comprises a strip element supply unit 16 for each frame assembly workstation 4, 4 ′. Similar feed units of the strip element may be provided for each workstation 5.5 'of the belt bracelet assembly.

Preferably, at least one of the workstations 4, 4 ′, 5, 5 ′, 6, 12, 14 in an ordered sequence comprises a device that includes a dispenser of a continuous elongated element of elastomeric material. In this case, each workstation containing such a device also contains one or more drives for moving the forming support with the possibility of winding a continuous elongated element in accordance with adjacent and / or at least partially overlapping rings. Even more preferably, at least the sub-breaker layer overlay unit 9, the tread band lower layer overlay unit 13, the tread band overlay unit 11, the sidewall overlay unit 17, the hermetic overlay unit 18 each comprise said device.

A tire assembly in accordance with an embodiment of the invention may comprise a preparation line for some basic elements (typically strip elements and / or rubber cords) adapted to be fed to workstations 4, 4 ', 5, 5'. Such a line is not shown in the drawing.

The transfer device 2, adapted to transfer the processed tire on its forming support from one workstation to another workstation of an ordered sequence, contains a mechanized arm. Preferably, the transfer device 2 is connected to a guide 15 along which such a mechanized arm moves.

Preferably, each manipulation device 3 for the machined tires on the respective forming supports comprises at least one mechanized arm.

According to preferred embodiments of the present invention, at least one assembled tire model is for two-wheeled vehicles in which the deflection ratio R is between the distance between the radially outer point of the tread band and the line passing through the transversely opposite ends of the tread band itself, measured in the equatorial plane of the tire, and the distance between said ends, measured along the tire chord, is greater than or equal to about 0.15.

In particular, the deflection ratio R is less than or equal to about 0.3, or less than or equal to about 0.45, depending on which tire to be assembled, rear or front.

Preferably, the forming support is a toroidal support. Even more preferably, the toroidal support comprises a radially outer surface corresponding to the radially inner surface of the processed (and assembled) tire.

A method for selecting workstations 4, 4 ', 5, 5', 6, 12, 14 in bus assembly line 1 of at least two different models, in which assembly line 1 contains a plurality of workstations 4, 4 ', 5, 5 ', 6, 12, 14 arranged in accordance with an ordered sequence, each workstation 4, 4', 5, 5 ', 6, 12, 14 being configured to assemble at least one structural element of each bus, preferably , by assembling at least one base element, in accordance with the present invention includes the step of:

selection of at least two workstations 4, 4 ', 5, 5', 6, 12, 14, not adjacent to each other, onto which the processed bus is transferred, based on the bus model, the assembled structural element and the availability of the workstations themselves .

The transfer is carried out so that the processed bus moves only in at least two workstations 4, 4 ', 5, 5', 6, 12, 14 along the transfer path.

The method for selecting workstations 4, 4 ', 5, 5', 6, 12, 14 includes, before the selection step, the step of receiving information about the assembled bus model and the availability of workstations 4, 4 ', 5, 5', 6, 12 , fourteen.

In other words, the selection method in accordance with the invention provides for the reception of information and its processing with the possibility of choosing the most suitable workstations 4, 4 ', 5, 5', 6, 12, 14 for transferring processed buses.

Preferably, in accordance with step a), the tire assembly process comprises placing a plurality of basic elements of the assembled tires in a plurality of workstations 4, 4 ′, 5, 5 ′, 6, 12, 14.

The process then includes step b) assembling at least a first and a second tire model on respective forming supports, assembling each structural element, preferably by assembling at least one of the basic elements, at workstations 4, 4 ′, 5 , 5 ', 6, 12, 14. The latter are placed in accordance with the ordered sequence in the tire assembly line 1, and the processed tires on the corresponding forming supports are transferred from one workstation 4, 4', 5, 5 ', 6, 12, 14 to another by means of the transfer device 2.

In accordance with the invention, step b) of assembling at least the first and second tire model includes at least one step c) transferring the workpiece to its own forming support from the first workstation 4, 4 ′, 5, 5 ′, 6, 12, 14 of assembly line 1 to a second, non-adjacent workstation 4, 4 ′, 5, 5 ′, 6, 12, 14 in an ordered sequence.

In addition, in accordance with the method of the present invention, each step c) of the transfer is carried out so that the processed tire on its own forming support moves only in the first and second workstations 4, 4 ', 5, 5', 6, 12, 14 along transfer paths.

According to a preferred embodiment, the assembly step b) includes, before the transfer step c), the step:

d) selecting a workstation 4, 4 ', 5, 5', 6, 12, 14, on which the bus to be processed is transferred, based on the bus model, the assembled structural element and the availability of workstations 4, 4 ', 5, 5', 6, 12, 14.

Assembly step b) is preferably carried out by transferring the bus to be processed from the workstation 4, 4 ′, 5, 5 ′, 6, 12, 14 to the next workstation 4, 4 ′, 5, 5 ′, 6, 12, 14 ordered sequence. That is, the transfer is carried out in accordance with the direction of movement of the assembly line 1.

In particular, assembly step c) includes the steps of:

i) assembly of the frame, which contains at least one layer of the frame and a pair of annular fixing structures,

ii) assembling a belt bracelet that contains at least one layer of belt, and

iii) the assembly of the tread band.

According to a preferred embodiment, step ii) comprises assembling a bracelet containing a layer of textile or metal cords oriented in the circumferential direction at an angle of 0 °.

A method of manufacturing tires also includes a preliminary step of supplying the basic elements to the corresponding workstation.

With reference to the tire assembly line 1, a valid example of the assembly shown in FIG. 1 will be described below, for example, in the case of two tire models A and B, where A is a single layer tire and B is a two-layer tire, wherein A and B both contain a layer metal cords at an angle of 0 ° as a bracelet.

The forming support for the machined tire A is transferred to the pressurization workstation 14, in which the pressurization application unit 18 imposes a pressurized layer on it, preferably by applying at least one continuous elongated element of elastomeric material in accordance with adjacent and / or overlapping rings. Such a step of applying a pressure layer may be preceded by a step of applying at least one fabric to strengthen the bead and / or a step of applying a wear-resistant element to the forming support of the tire A.

Then, it is also possible to impose a lower hermetic layer in a position radially external to the hermetic layer.

The processed bus A is transferred to the carcass assembly workstation 4 or 4 ', in accordance with the type of layer required for bus A, or the availability of the said workstations 4, 4', where, according to step i), the carcass is assembled. In this example, the single layer bus A is transferred by the transfer device 2 from the pressurization workstation 14 directly to the second frame assembly workstation 4 ′, if the latter is free, bypassing the first frame assembly workstation 4, in accordance with the procedure in the step of selecting the above method and with step c) of the method in accordance with the invention.

In the second carcass assembly workstation 4 ', a carcass ply is applied at a position radially external to the hermetic layer or lower hermetic layer (if provided) by means of a layer superimposing unit 7, preferably by layering a plurality of strip elements next to each other. In accordance with other design specifications, additional basic elements may be imposed for the manufacture of additional structural elements of the frame.

Then step i) involves the application of at least a pair of annular anchoring structures at axially opposite ends of the carcass ply. This stage is carried out through the node 8 overlay core bead, the operation of which is described below.

Then, a plurality of internal and / or external reinforcing elements and / or a wear-resistant element can be applied in the carcass layer of the tire A to be processed.

Simultaneously with the assembly of the tire A, the tire B is also assembled in accordance with step b) of the method described above.

More specifically, the forming support of the machined tire B is transferred to the pressurized workstation 14 as soon as it is freed from the machined tire A. The method described above for tire A is carried out in the pressurized workstation 14.

Then, in accordance with step i) of the present invention, the carcass is assembled: the processed bus B is transferred by the transfer device 2 to the first workstation 4 of the carcass assembly for applying the first carcass layer, and such a workstation is free since the bus A is transferred to the second workstation 4 'frame assembly. After that, the transfer device 2 transfers the bus B to the second frame assembly workstation 4 ′ for applying the second frame layer as soon as the tire A, after completing the frame assembly step, is transferred from the workstation.

In particular, on the second carcass assembly workstation 4 ′, a second carcass ply is applied in a position radially external to the first carcass ply of the tire B using methods similar to the methods for applying the first carcass ply. After this step, at least an additional pair of annular fastening structures is superimposed on the axially opposite ends of the second carcass ply.

Then, in accordance with step c), the tire to be processed is transferred by means of the transfer device 2 to the second work station 5 'of the assembly of the belt bracelet.

In other words, in the example illustrated in this document, the processed tire A is transferred from the second frame assembly workstation 4 ′ to the second belt bracelet assembly workstation 5 ′, bypassing the first belt bracelet assembly workstation 5.

In such a second belt bracelet assembly workstation 5 ′, step ii) of the belt bracelet assembly is carried out, which, in this particular example, involves first applying a sub-belt layer in a position radially external to the tire A processed by the sub-belt layer applying unit 9, preferably , by applying at least one continuous elongated element of elastomeric material in accordance with adjacent and / or partially overlapping rings, then applying a layer a breaker obtained by applying a layer of rubber cord, oriented in the circumferential direction at an angle of 0 °, in a particular node 10 overlay layer of the breaker.

In accordance with the aforementioned step c), the processed tire B is transferred by means of the transfer device 2 to the second workstation 5 'of the assembly of the bracelet.

In other words, the processed tire B is transferred from the first frame assembly workstation 4 to the second belt bracelet assembly workstation 5 ', bypassing workstation 5.

In addition, it should be noted that, due to the preferred configuration of the second belt bracelet assembly workstation 5 ′ (comprising two belt layer overlay assemblies 10), transfer of the bus B to the workstation can preferably be carried out even if the workstation is still located tire A.

Step ii) of assembling the bracelet of the tire B is carried out in such a workstation 5 'by analogy with that described above for the assembly of the tire A.

Then, the processed tire A is transferred via the transfer device 2 to the tread band assembly workstation 6, in which step iii) of the tread band assembly is carried out. Such step iii) may include a sub-step iii ″) of applying at least one lower layer of the tread band in a position radially external to the belt bracelet in the overlay unit 13 of the lower layer of the tread band. Finally, step iii) includes a sub-step iii ″) of applying at least one layer of the tread band in a position radially external to said lower layer of the tread band, if provided, or with respect to the belt band, in the tread overlay unit 11 bracelet. If two layers of the tread band are provided, then they are preferably applied sequentially in two respective overlay sections 11 of the tread band. Preferably, at least one of steps iii ′) and iii ″) is performed by applying at least one continuous elongated element of elastomeric material in accordance with adjacent and / or at least partially overlapping rings.

At the end of the belt bracelet assembly, the processed tire B is also transferred via the transfer device 2 to the tread band assembly workstation 6, in which step iii) of the tread band assembly is carried out using methods similar to those described for assembling the tread band of the tire A.

In addition, in this case, due to the preferred configuration of the tread band assembly workstation 6 (containing two tread band bracelet overlay assemblies 11), the tire B can be transferred to the tread band assembly workstation 6 while the tire A is still on it, further increasing productivity.

Then, the processed tire A is transferred by means of the transfer device 2 to the side station assembly workstation 12. In such a workstation 12, the sidewall overlay assembly 17 provides at least one part of the sidewalls of the tire A in a position axially external to the tread band, performing step iv) by applying at least one continuous elongated element of elastomeric material in accordance with adjacent and / or partially overlapping rings.

After that, the processed tire B is also transferred by means of the transfer device 2 to the sidewall assembly workstation 12, in which the sidewall superimposing unit 17 provides for the application of at least one part of the sidewalls of tire B using methods similar to those described for tire A.

Tires A and B thus assembled are transferred to optional additional workstations for applying optional elements such as bar codes, labels, etc., or to exit assembly line 1 to move toward a molding and vulcanizing unit not shown in this document.

Within the scope of the above description and in the formula below, all numerical values indicating quantities, parameters, percentages, etc., should be taken with the prefix "approximately", unless otherwise specified. In addition, all ranges of numerical values include all possible combinations of maximum and minimum numerical values and all possible intermediate ranges, in addition to those specifically indicated in the text.

Claims (51)

1. The method of selecting workstations (4, 4 ', 5, 5', 6, 12, 14) in the tire assembly line (1) for the wheels of the vehicle, the tires being tires of at least two different models, wherein assembly line (1) contains many workstations (4, 4 ', 5, 5', 6, 12, 14) arranged in accordance with an ordered sequence, with each workstation (4, 4 ', 5, 5', 6 , 12, 14) is configured to assemble at least one structural element of each tire, the method comprising the step of:
transferring, on the basis of the bus model, the assembled structural element, and the availability of the workstations themselves, the processed bus from the first workstation (4, 4 ', 5, 5', 6, 12, 14) to a second, non-adjacent workstation in said ordered sequence, bypassing any workstation located in said ordered sequence, between the first workstation and the second workstation. 2. The method according to claim 1, in which the selection step is preceded by the step of receiving information about the assembled bus model and the availability of workstations (4, 4 ', 5, 5', 6, 12, 14). 3. A method of manufacturing tires for vehicle wheels, the tires being tires of at least two different models, comprising the steps of:
b) assembling at least the first and second tire models on the respective forming supports by assembling each structural element on a plurality of workstations (4, 4 ', 5, 5', 6, 12, 14) arranged in accordance with the ordered the sequence in the tire assembly line (1), the tires being processed on the respective forming supports being transferred from one workstation (4, 4 ', 5, 5', 6, 12, 14) to another by means of a transfer device (2);
moreover, step b) of assembling at least the first and second tire model includes at least one step c) transferring the workpiece to be processed on its own forming support from the first workstation (4, 4 ', 5, 5', 6, 12, 14) assembly lines (1) to a second non-adjacent workstation (4, 4 ′, 5, 5 ′, 6, 12, 14) in said ordered sequence; moreover, the processed tire on its forming support is transferred from the first workstation to the second workstation, bypassing any workstation located, in the mentioned ordered sequence, between the first workstation and the second workstation. 4. The method according to claim 3, in which step b) of the assembly is preceded by step a) placing a plurality of basic elements of the assembled tires on a plurality of workstations (4, 4 ′, 5, 5 ′, 6, 12, 14). 5. The method according to claim 3, wherein step b) of the assembly includes, before step c) the transfer, step d) selecting a workstation (4, 4 ', 5, 5', 6, 12, 14) to which the workpiece is being transferred a bus based on a bus model, an assembled structural element and the availability of the workstations themselves (4, 4 ', 5, 5', 6, 12, 14). 6. The method according to claim 3, in which step b) of the assembly is carried out by transferring the machined tire on its own forming support from the workstation (4, 4 ', 5, 5', 6, 12, 14) to the next workstation (4 4 ', 5, 5', 6, 12, 14) of said ordered sequence. 7. The method according to claim 3, in which the step b) of the assembly includes the steps of:
i) assembly of the frame containing at least one layer of the frame and a pair of annular fixing structures;
ii) assembling a belt bracelet containing at least one layer of belt; and
iii) the assembly of the tread band. 8. The method according to claim 7, wherein in at least one assembled tire model, the deflection ratio R is between the distance between the radially outer portion of the tread band and the line passing through the transversely opposite ends of the tread band itself, measured in the equatorial plane of the tire, and the distance between said ends, measured along the tire chord, is greater than or equal to about 0.15. 9. The method of claim 8, wherein the deflection ratio R is less than or equal to about 0.3. 10. The method of claim 8, wherein the deflection ratio R is less than or equal to about 0.45. 11. The method according to claim 7, wherein in step ii), at least one layer of the breaker is a layer of textile or metal cords oriented in the circumferential direction at an angle of 0 °. 12. The method according to claim 7, wherein step iii) of assembling the tread band includes a step iii ′) of applying the tread band in a position radially external to the belt band. 13. The method according to claim 7, in which stage iv) of applying at least one part of the sidewalls of the processed tire in a position axially external to the processed tire is carried out. 14. The method of claim 12, wherein step iii) of assembling the tread band includes, before step iii ') of applying the tread band, step iii ") of applying at least one lower layer of the tread band in a position radially external to to a bracelet. 15. The method according to item 12, in which at least one of the steps iii '), iii ") or iv) is carried out by applying at least one continuous elongated element of elastomeric material in accordance with adjacent or, at least partially overlapping rings. 16. The method according to claim 3, in which at least one structural element is assembled by assembling at least one base element. 17. The method according to claim 3, in which additionally carry out a preliminary supply of basic elements to at least one workstation (4, 4 ', 5, 5', 6, 12, 14). 18. The method according to claim 3, in which the forming support is a toroidal support. 19. The method according to p, in which the toroidal support contains a radially outer surface corresponding to the radially inner surface of the processed tire. 20. The method according to claim 3, in which the first and second tire models differ in size. 21. The method according to claim 3, in which the first and second tire models differ in structural elements. 22. The method according to claim 3, in which the first and second tire models differ in basic elements. 23. An assembly for assembling tires for vehicle wheels, the tires being tires of at least two different models, comprising at least one tire assembly line (1), which in turn contains:
a plurality of workstations (4, 4 ', 5, 5', 6, 12, 14) arranged in accordance with an ordered sequence, each workstation (4, 4 ', 5, 5', 6, 12, 14) being made with the possibility of assembling at least one structural element of each tire;
at least one manipulation device (3) for the machined tires on the respective forming supports associated with each workstation (4, 4 ', 5, 5', 6, 12, 14); and
at least one transfer device (2), configured to transfer the tire to be processed on its forming support from any first workstation (4, 4 ', 5, 5', 6, 12, 14) of said ordered sequence to any other second not a workstation adjacent to it (4, 4 ', 5, 5', 6, 12, 14) of said ordered sequence, so that the processed tire on its forming support moves from the first workstation to the second workstation, bypassing any workstation located, in said ordered sequence, between at the first workstation and a second workstation. 24. The unit according to item 23, in which many workstations (4, 4 ', 5, 5', 6, 12, 14) includes:
at least one workstation (4.4 ') of the frame assembly, the frame comprising at least one layer of the frame and a pair of annular fixing structures;
at least one workstation (5.5 ') assembly belt bracelet, and the belt bracelet contains at least one layer of a broker; and
at least one workstation (6) of the tread band assembly. 25. The assembly according to item 23, in which the forming support is a toroidal support. 26. The assembly of claim 25, wherein the toroidal support comprises a radially outer surface corresponding to a radially inner surface of the tire being machined. 27. The unit according to paragraph 24, which provides two workstations (4.4 ') of the frame assembly. 28. The assembly according to claim 27, wherein the first frame assembly workstation (4) is configured to assemble a framework different from the framework assembled by the second frame assembly workstation (4 '). 29. The assembly according to item 23, in which at least one workstation (4, 4 ', 5, 5', 6, 12, 14) is configured to assemble at least one structural element of each bus by assemblies of at least one base element. 30. The unit according to paragraph 24, in which each workstation (4.4 ') assembly of the frame contains at least:
one node (7) overlay layer and
one node (8) of the overlay core. 31. The assembly according to claim 30, wherein the bead core application unit (8) comprises at least one device including a dispenser of a continuous elongated element made in the form of a rubber reinforcing cord. 32. The assembly according to p. 31, in which at least one drive is connected to a manipulation device (3) connected to the frame assembly workstation (4, 4 ') for moving the forming support with the possibility of applying a continuous elongated element in accordance with radially overlapping rings. 33. The assembly according to paragraph 24, in which the frame assembly workstation (5.5 ′) comprises a sub-breaker layer overlay unit (9) comprising devices for applying a sub-breaker layer in a position radially external to the frame. 34. The unit according to paragraph 24, in which the workstation (5.5 ') of the assembly of the belt bracelet contains at least one node (10) overlay layer of the belt containing devices for applying at least the first layer of belt in position radially external to the frame. 35. The unit according to clause 34, in which there are two nodes (10) overlay layer of the breaker. 36. The unit according to paragraph 24, which provides for at least two workstations (5.5 ') assembly belt bracelet. 37. The unit according to clause 36, in which the first workstation (5) assembling the belt bracelet is configured to impose at least two radially overlapping layers of the belt, the layers being arranged so that the cords of the first layer are oriented at an angle relative to the equatorial plane processed tires, and the cords of the second layer also have an inclined orientation, but symmetrically cross with respect to the cords of the first layer. 38. The unit according to clause 36, in which the second workstation (5 ') of the assembly of the bracelet is made with the possibility of applying at least one layer of the broker, which is a layer of metal cords oriented in the circumferential direction at an angle of 0 °. 39. The unit according to paragraph 24, in which the workstation (6) assembly of the tread band contains at least one node (11) overlay tread band. 40. The unit according to clause 39, in which there are two nodes (11) for applying a tread band. 41. The assembly according to paragraph 24, further comprising at least one node (13) for applying the lower layer of the tread band, comprising devices for applying at least one lower layer of the tread band. 42. The assembly according to paragraph 41, wherein said one node (13) for applying the lower layer of the tread band is located on the workstation (6) of the tread band assembly. 43. The assembly according to claim 24, further comprising at least one sidewall assembly workstation (12), comprising a sidewall assembly (17) for assembling at least one part of the sidewall in a position axially external to the workpiece to the bus. 44. The assembly according to claim 24, further comprising a workstation (14) for applying the hermetic layer, comprising a unit (18) for applying the hermetic layer. 45. The assembly according to item 23, further comprising at least one node (16) for supplying the strip element. 46. The unit according to item 23, in which at least one of the workstations (4, 4 ', 5, 5', 6, 12, 14) contains at least one device containing a dispenser continuous elongated element from elastomeric material. 47. The unit according to item 46, in which at least one drive is connected to a manipulation device (3) associated with a workstation (4, 4 ', 5, 5', 6, 12, 14) to move the forming supports with the possibility of applying a continuous elongated element in accordance with adjacent or at least partially overlapping rings. 48. The unit according to clause 29, containing a line for the preparation of basic elements, made with the possibility of filing at least one workstation (4, 4 ', 5, 5', 6, 12, 14). 49. The assembly according to item 23, in which the transfer device (2), made with the possibility of transferring the processed tire on its own forming support from one workstation (4, 4 ', 5, 5', 6, 12, 14) to another the workstation (4, 4 ', 5, 5', 6, 12, 14) of the said ordered sequence contains at least one mechanical arm. 50. The unit according to item 23, in which the transfer device (2) is connected with the guide (15). 51. The unit according to item 23, in which the device (3) manipulation for the processed tires on the respective forming supports contains at least one mechanical arm.

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