WO2013164282A1

WO2013164282A1 - Chamber for vulcanizing the inner portion of a tire and including a fan

Info

Publication number: WO2013164282A1
Application number: PCT/EP2013/058809
Authority: WO
Inventors: Jean-Claude Cambon; Thomas SIMONELLI; Romain MUGGEO; Gilles WALRAND; Jean-Charles Ferrand; Miguel TORRES-CATELLANO; Christophe Masclaux
Original assignee: Compagnie Generale Des Etablissements Michelin; Michelin Recherche Et Technique S.A.
Priority date: 2012-05-02
Filing date: 2013-04-26
Publication date: 2013-11-07
Also published as: FR2990150A1; FR2990150B1

Abstract

The invention relates to a chamber (1) for vulcanizing the inner portion of a tire (P), which is defined by the inner portions of an upper plate (12) and control plate (11) and of a curing membrane (10), the two beads (13, 14) being attached onto the periphery of said plates, wherein the inside of the chamber has an axis XX' and includes a heating means (50, 51) and a rotated circulation fan (40) having a given outlet cross-section SF, the chamber being suitable for agitating a heat-transport fluid. The casing also comprises pipe means (60, 70) for the heat-transport fluid arranged directly at the outlet of the circulation fan (40).

Description

ENCLOSURE FOR VULCANIZING THE INNER PART OF A TIRE

CONTAINING A FAN

[001] The invention relates to the field of tire vulcanization and is more particularly concerned with vulcanization enclosures in which the supply of calories is made using means located directly inside said enclosure. Pneumatic vulcanization enclosures are known in which the supply of heat transfer fluid is from a remote fan via a duct opening into the enclosure. Such an enclosure is described in document EP 0 578 105 in which the fan used for stirring a heat-transfer fluid is arranged at a distance from the cooking membrane and communicates with the internal part thereof by a supply duct after having passed through. a heating element. Other documents having a similar construction are described in EP 0 246 495, US 5 186 951 or JP 5104541.

[003] The devices described in these documents allow, certainly, to print a good orientation of the heat transfer fluid flow as soon as it arrives inside the cooking membrane when it is deployed, but at the cost of a large bulk overall, while subjecting significant heat losses to the heat transfer fluid with, as a result, a decrease in the speed thereof.

[004] Other types of devices, such as those described by way of example in the publication EP 0 686 492 or in the US publication, are also known.

In these documents, a heat transfer fluid, generally pressurized nitrogen, circulates in the internal cavity of the chamber using a circulation fan driven by an electric motor fully immersed in said coolant. The necessary calories are provided by heating elements such as resistors or induction heating means placed in the path of the heat transfer fluid.

[005] Figure 1 schematically describes a known device of the type above.

[006] The vulcanization chamber 1 of the inner part is delimited by a lower plate 1 1 and an upper plate 12, connected by an elastic membrane 10, wherein the two beads 13 and 14 are anchored to the circumference of said trays, and being pressed against the inner part of the tire under the effect of the pressure of the coolant. The inner chamber collaborates in a known manner with a rigid mold for imparting its external shape to said tire and formed of two shells (not shown) for molding the sidewalls and by annular sectors (not shown) for molding the tread .

[007] The central part of the enclosure comprises a maneuvering axis 20, concentric with the axis of revolution XX 'of the enclosure, for axially animating the upper and lower trays during the introduction and extraction phases of the tire. A hollow shaft 30 rotates the seat 31 carrying the blades of a fan 40.

[008] The coolant is introduced under pressure into the vulcanization chamber 1 at the beginning of the cycle by a conduit 22. The conduit 22 also extracts the fluid at the end of the cycle. In theory, under the action of the circulation fan and with reference to the arrows of FIG. 1, the heat-transfer fluid is sucked up at the central portion 43 of the fan 40, passes through the bundle of heating elements 50, and is then ejected in the lower part of the chamber and just lick the walls of the membrane where heat exchange with the tire through said membrane. [009] These devices have a compact construction and can print significant tangential velocities to the heat transfer fluid inside the membrane when it is deployed, which ensures a good heat exchange with the tire.

[010] However, it is observed that these devices sometimes fail to distribute the heat evenly over the entire inner surface of the tire, due in particular to uncontrolled circulation of the heat transfer fluid inside the enclosure.

[011] A detailed aeraulic study makes it possible to simulate the circulation of the coolant in the enclosure according to the dimensions of the tire to be manufactured. [012] These simulations show that, for certain dimensions, in particular the large diameter or large width dimensions, the flows in the enclosure are not established in the manner described above.

[013] Recirculation loops of the type of those illustrated in Figure 2, appear in certain areas of the enclosure ti, t ₂ , t _3. , in which it is noted that the fluid in contact with the wall of the membrane turns on itself without ironing through the center of the fan,

[014] It is also observed that, under the effect of the rotary movement imparted by the fan, the heat transfer fluid assembly is rotated about the axis XX ', as shown in FIG. 3.

[015] These two phenomena have the effect of greatly reducing the return of the "cold" flow from the wall of the membrane 10 to the heating elements 50.

[016] The object of the invention is to propose means capable of modifying the orientation and the speed of the heat transfer fluid flow at the outlet of the fan, so as to eliminate the appearance of these phenomena, whatever the size. of the tire to vulcanize, for an improved heat exchange with it.

[017] These objects are achieved with a vulcanization chamber of the inner surface of a tire defined by the inner portions of an upper plate and a maneuvering plate and a baking membrane whose two beads are fixed at the circumference of said trays, the interior of the chamber of axis XX 'comprising heating means and a circulation fan rotated, given output section S _F , and for stirring a heat transfer fluid. This enclosure is characterized in that means for channeling the flow of heat transfer fluid are arranged at the immediate output of the fan.

[018] By the interior or center of the vulcanization chamber according to the invention, the space having substantially a cylinder shape, the cylinder passing substantially at the edges of the baking membrane and being delimited in height by two planes perpendicular to the axis XX 'of the enclosure (or the axis of rotation of the vulcanized tire) these planes passing, one by the upper beads of the membrane (or the fixing beads to the maneuvering plate) and the other by the lower beads of the membrane (or the attachment beads to the lower plate thereof). Thus, when it is deployed, the heating means and the fan are located entirely inside the cooking membrane, which makes it possible to obtain significant tangential velocities of the heat transfer fluid inside the enclosure, an improved heat exchange between the fluid and the heating element, for a very compact construction means for stirring the fluid in the enclosure.

[019] According to the invention, the enclosure comprises flow channeling means coolant fluid disposed at the immediate output of the fan. Here means means of channeling means disposed at the outlet of the circulation fan at the radially outer circumference of said fan, and upstream of the point of entry into contact of the hot heat transfer fluid with the wall of the membrane to exchange calories with the pneumatic, and adapted to redirect the flow of heat transfer fluid in a given direction, to concentrate the stream vein, or to increase the speed of the heat transfer fluid. Each of these actions can be conducted separately or in combination. These channeling means are therefore together with the fan and the heating means in the cylindrical space forming the inside of the vulcanization chamber, as previously defined.

[020] According to a first embodiment, the flow channeling means are formed by a non-rotating confinement means capable of concentrating the output flow in the axial direction and orienting it in the radial direction.

[021] Preferably, the confinement means are formed by at least one substantially frustoconical wall of axis XX '.

[022] Preferably, the frustoconical wall or walls are oriented so that the opening or openings of smaller section are disposed on the side of the inlet of the coolant flow in the fan.

[023] Preferably, the small diameter of the frustoconical wall is substantially equal to the radially outer diameter of the circulation fan, and in which the radially outer diameter and the apex angle of said frustoconical wall are adapted so that the outlet section the containment means is less than the output section of the circulation fan, and greater than one quarter of said section. [024] According to a particular embodiment of this first embodiment the vulcanization chamber may comprise two frustoconical walls arranged symmetrically with respect to the equatorial plane of the enclosure so that the output flow of the circulation fan is concentrated at the equator of said enclosure. [025] According to a second embodiment of the invention, the flow channeling means are formed by non-rotating rectifying means, capable of directing the output flow of the circulation fan in the radial direction of said enclosure and to strongly reduce the component of rotation around the axis XX 'of the flow. [026] Preferably, the rectifying means are formed by blades, each having walls whose outer surface is generated by lines substantially parallel to the axis XX 'and disposed at the radially outer circumference of the fan. [027] Preferably, in projection in a plane perpendicular to the axis XX ', said blades have radially increasing cross sections.

[028] The invention also provides the possibility of combining means for confining the output flow of the circulation fan according to the first embodiment and rectifying means according to the second embodiment. [029] Preferably, the recovery means can then be carried by the confinement means.

[030] Whatever the embodiment of the invention, the heating means may be arranged axially upstream of the fan, or be inserted into the flow channeling means. [031] To improve the efficiency of the assembly, at least one input rectifier can be arranged to channel the heat transfer fluid axially at the inlet of the circulation fan, and to radially redirect it. towards the upstream portion of said circulation fan.

[032] The following description is based on Figures 1 to 16 in which:

FIG. 1 represents a vulcanization chamber according to the known prior art,

FIG. 2 represents, in a radial sectional view of the enclosure, a simulation of the circulation of flows,

FIG. 3 represents, in a perspective view, a simulation of the flow flow,

FIG. 4 represents a radial sectional view of a first embodiment of an enclosure according to the invention,

FIG. 5 represents a perspective view of a confinement wall according to the invention,

FIG. 6 represents an enlarged radial sectional view of part of FIG. 4,

FIG. 7 represents a radial sectional view of a second embodiment of an enclosure according to the invention, FIG. 8 represents a radial sectional view of a combination of the two embodiments of the invention above,

FIG. 9 represents a perspective view of an input rectifier for sucking the coolant flows at the inlet of the circulation fan,

FIG. 10 represents a perspective view of an output rectifier, FIG. 11 represents the different combinations of shapes of the vanes of the circulation fan and the output rectifier,

FIG. 12 represents a particularly advantageous embodiment of the blades of the output rectifier used in the second embodiment of the invention,

FIGS. 13 and 14 show particular modes of implantation of the heating means in an enclosure according to the invention,

FIG. 15 represents, in a perspective view, the circulation of the flows in the enclosure after implementation of the channeling devices according to the invention,

Figure 16 shows a particular embodiment of the first embodiment of the invention.

[033] The chamber illustrated in Figure 4 shows all the characteristics of the known prior art chamber illustrated in Figure 1 wherein the heat transfer fluid mixing means, more particularly the heating means and the fan of circulation 40, are arranged in the part forming the interior or center of the vulcanization chamber. The vulcanization chamber is delimited by the cooking membrane 10 when it is deployed by the heat transfer fluid under pressure and by the internal parts of an upper plate 12 and a maneuvering plate 1 1. However, it differs in that it comprises, according to a first embodiment of the invention, a flux concentrator in the axial direction, placed directly at the outlet of the circulation fan 40, and for orienting the flow of fluid in the radial direction of the enclosure. [034] The shape of the concentrator is substantially that of a truncated cone as illustrated in FIG. 5. The small diameter D _f of the cone 60, corresponding to the upper lip 61, is adjusted so as to correspond substantially to the diameter radially external of the circulation fan 40.

[035] This concentrator is fixedly mounted on the inner surface of the operating plate 11 by means of rods 63. The height of the rods 63, the height and the angle at the apex a of the frustoconical wall, and consequently the diameter Φ ₀ corresponding to the lower lip 62 of the cone 60, are adjusted so that the output section of the concentrator is less than the exit section of the circulation fan and greater than quarter of said output section. Let S _{F be} the output section of the fan, we have 8 _Ρ = π ^χ φ _Ρ ^χ Η _Ρ . The output section of the concentrator S _c is equal to S _c = π ^χ φ ₀ x H _c and can usefully be between

vs

S _F and S _F / 4, ie: S _F > S _c >.

[036] It will also be verified that the diameter Φ ₀ is smaller than the diameter of the operating plate so as to allow the movement of the membrane 10 during the introduction and extraction of the tire operations at each baking cycle.

[037] Preferably, it is also arranged so that the concentrator 60 is mounted so that the flow of heat transfer fluid is directed to the side of the operating plate 1 January. The hottest flow brings calories in priority to the part of the enclosure most exposed to heat loss.

The portion of smaller section of the frustoconical wall is thus placed on the side of the inlet orifice 41 of the return flow in the circulation fan 40.

[039] The concentrator 60 makes it possible to obtain several simultaneous effects. Concentrating and channeling the flow in the axial direction increases the radial velocity of the coolant flow and reduces the rotation of the fluid mass as shown in FIG. the output flow force the flow along the baking membrane and increases the heat exchange between the hot stream and the tire.

[040] The concentrator also forms a barrier for limiting the flow returns in the lower part corresponding to the zone t-ι of Figure 2.

[041] Figure 7 illustrates another embodiment of the invention in which rectifying means are provided at the output of the fan 40. These rectifying means are formed by vanes 74 of an output rectifier 70, each of these blades having an outer wall formed of lines substantially parallel to the axis XX 'of the enclosure. The blades 74 of the output rectifier 70 are arranged at the radially outer circumference of the vanes of the fan 40. [042] The blades 74 of the output rectifier 70 have the effect of orienting the flow in the radial direction so as to counteract the rotation of the fluid mass as shown in FIG. 3.

[043] Of course, we can usefully combine the means according to the first and second embodiments of the invention by simultaneously arranging a flow concentrator 60 and rectifying vanes 74 downstream of the fan. These two means can usefully be attached to one another as shown in Figure 8.

[044] To improve the circulation of the flow and reinforce the action of the channeling means, it is possible to place an input rectifier 80, as shown in FIG. 9, whose blades may also be designated by the term input direction, for axially concentrating the incoming flow at the orifice 41 and radially redirect it towards the inlet of the fan. This increases the booster at the inlet of the fan 40 and improves the air flow efficiency of the latter and consequently increase the relative speed of the fluid output of the fan 40. This input rectifier 80 allows also to compensate for the pressure losses generated by the heating means 50 interposed upstream of the vanes of the circulation fan 40.

[045] In the case of the device shown in Figure 8, the blades of the input flow rectifier 80 are fixed, but it is quite possible to give a rotary movement to these blades so as to increase the helical effect centrifugal.

[046] Figure 1 1 illustrates, in top view, several embodiments of the blades of the circulation fan 40 and the output rectifier 70. The shape of these blades can be optimized for the purpose of arranging the flow output of the assembly formed by the circulation fan and the output rectifier. We can in a known manner, try to optimize the output speed or the more or less radial orientation of this flow.

[047] Thus, the center of curvature of the blades 42 or 42 'can be placed on one side or the other of the blades. [048] The blades of the output rectifier 70 may have a straight profile 71 or, for a better air flow performance have a curved profile 72, or have an intermediate profile formed by broken lines 71 '.

[049] Of all these possible forms and combinations, the form shown in Figure 12 is of particular interest. Indeed, the blades 73 (see inset of Figure 12) have cross sections radially increasing SD-ι, SD ₂ , SD ₃ .

[050] It follows that, for blades of constant axial height H, it can be arranged for the distance L _s between two blades juxtaposed downstream of the output rectifier is less than or equal to the distance L _E between these two blades at the inlet of said rectifier. The downstream section S _R of the output rectifier is then less than or equal to the output section S _F of the fan. This particular shape makes it possible to increase the speed of the flow downstream of the output rectifier.

[051] These effects can of course be combined with the effects described above and related to the output section of the concentrator, when the two flow channeling means are used simultaneously.

[052] It is also possible to take advantage of the non-movable nature of the channeling means according to the invention, in that they are brought to be in close contact with the coolant flow. Also, it may seem advisable to place the heating means directly inside the channeling means as shown in FIG. 14 where these heating means 51 are located in the wall of the concentrator 60 and where the heating means 52 are located in the inner wall of the operating plate 1 1. It will be observed that it is possible to obtain equivalent results by arranging these heating elements in the vanes of the output rectifier by integrating, for example, electric heating means by Joule effect. Or we can combine these two propositions.

[053] This particular arrangement as shown in Figure 14 reduces the pressure losses upstream of the blades of the circulation fan when the heating elements are placed upstream of the fan blades as shown in Figure 13.

[054] Each of the flow channeling devices as discussed above, considered in isolation or in combination with each other, circulate the heat transfer fluid from the inner walls of the membrane where operate the heat exchange with the tire to the heating means as shown in FIG.

[055] The vortex zones in which the fluid loops back on itself and cools are completely removed, and the temperature heterogeneities noted with the means of the state of the art such as those shown in Figure 1 disappear. [056] Figure 16 shows another alternative in the embodiment of the vulcanization chamber according to the invention wherein the flow at the outlet of the circulation fan is confined between two frustoconical walls 60 and 64, mounted on the operating plate 1 1 via rods 63, and arranged so that the output stream is concentrated at the equator E of the enclosure 1.

[057] The small diameters of each of the frustoconical walls are respectively disposed on the side of each of the inlets 41 and 42 of the heat transfer fluid flow to the circulation fan 40. At the outlet of the circulation fan, these two walls form a convergent whose output section 8 ₀ = π ^χ φ ₀ ^χ Η ' _ε , is smaller than the output section of the circulation fan and directs the flow towards the equator E at a speed V greater than the output speed of the fan of circulation.

[058] This configuration is particularly advantageous when the tire has a tread of great width relative to the height of its sidewalls. It makes it possible to direct the flow of hot heat transfer fluid over the thickest zone of the tire, which requires the addition of a greater number of calories.

[059] After sweeping the top of the membrane, the flow of heat transfer fluid is split into two separate streams directed respectively to the upper part and to the lower part of the enclosure. However, for this solution to be the most effective it is necessary to regulate the return flows so as to balance the flows in the circulation fan respectively by the upper part 41 and the lower part 42.

[060] Similarly to the previous configurations, it is possible to combine the confinement means 60, 64 with rectifying means 70, mounted between the two frustoconical walls or with input rectifiers 80 having blades arranged axially and oriented axially respectively to each of the flow inlets 41 and 42.

Claims

1) vulcanization chamber (1) of the inner surface of a tire (P) delimited by the internal parts of an upper plate (12) and a maneuvering plate (1 1) and a baking membrane (10) whose two beads (13, 14) are fixed to the circumference of said trays, the inside of the chamber of axis XX 'comprising heating means (50, 51), and a circulation fan (40). ) rotated, of given output section S _F , and intended to stir a heat transfer fluid, characterized in that the channeling means (60, 70) of the coolant flow are arranged at the immediate output of the circulation fan (40 ).

2) vulcanization chamber (1) according to claim 1, wherein the channeling means (60) of the flow are formed by a non-rotating confinement means, able to concentrate the output stream in the axial direction (XX ') and to orient it in the radial direction.

3) vulcanization chamber (1) according to claim 2, wherein the confinement means are formed by at least one substantially frustoconical wall (60) of axis XX '.

4) vulcanization chamber (1) according to claim 3, wherein the one or more frustoconical walls (60) are oriented so that the opening or openings of smaller section are arranged on the side of the inlet orifice (41, 42) of the coolant flow in the circulation fan (40).

5) vulcanization chamber (1) according to claim 4, wherein the small diameter of the frustoconical wall (D _F ) is substantially equal to the diameter of the radially outer portion of the circulation fan (40), and wherein the diameter radially external (<D _C ) and the apex angle (a) of said frustoconical wall are adapted such that the section (S _c ) at the outlet of the confinement means (60) is smaller than the outlet section (S _F ) of the circulation fan (40) and greater than one quarter (S _F / 4) of said section.

6) vulcanization chamber (1) according to one of claims 3 or 4, comprising two frustoconical walls (60, 64) arranged symmetrically with respect to the equatorial plane (E) of the enclosure, so that the flow into output of the circulation fan is concentrated at the equator (E) of said enclosure (1). 7) vulcanization chamber (1) according to claim 1, wherein the flow channeling means are formed by non-rotating straightening means (70), able to direct the output flow of the circulation fan in the radial direction of said enclosure (1). 8) vulcanization chamber (1) according to claim 7, wherein the rectifying means (70) are formed by vanes, each having walls whose outer surface is generated by lines substantially parallel to the axis XX.

9) vulcanization chamber (1) according to claim 8, wherein, in projection in a plane perpendicular to the axis XX ', said blades (70) have cross sections (SD ^ SD ₂ , SD ₃ ) radially increasing right .

10) vulcanization chamber (1) comprising a combination of the confinement means (60) of the output flow of the circulation fan (40) according to one of claims 2 to 6, and rectifying means (70) of the flow of outlet of the circulation fan (40) according to one of claims 7 to 9. 1 1) Vulcanisation chamber (1) according to claim 10, wherein the rectifying means (70) are carried by the confining means (60). ).

12) vulcanization chamber (1) according to one of claims 1 to 1 1, wherein the heating means (50) are arranged axially upstream of the circulation fan (40). 13) vulcanization chamber (1) according to one of claims 1 to 1 1, wherein the heating means (51) are inserted into the flow channeling means.

14) vulcanization chamber (1) according to one of claims 1 to 13, wherein at least one inlet rectifier (80) is arranged to orient axially the heat transfer fluid at the inlet port ( 41) of the circulation fan (40), and to radially redirect it towards the upstream portion of said circulation fan.