DE2420937A1 - METHOD AND DEVICE FOR VULCANIZING A TUBE-SHAPED SEMI-FINISHED PRODUCT MADE OF UNVULCANIZED RUBBER, IN PARTICULAR A SEMI-FINISHED PRODUCT FOR MOTOR VEHICLE RADIATOR HOSES - Google Patents

Description

INDUSTRY PIRELLI S.p.A. Milan, Italy

Method and device for vulcanizing a tubular semi-finished product made from unvulcanized material Rubber, in particular a semi-finished product for motor vehicle radiator hoses

Priority of 05/29/1973; Italy

The invention relates to a method and a device for vulcanizing a tubular semi-finished product made of non-vulcanized rubber, in particular a semi-finished product for an article that is rectilinear or non-rectilinear Has axis and can have sudden changes in diameter, such as motor vehicle radiator hoses.

As is known, these hoses are made by making semi-finished products from a non-vulcanized Rubber composition in which reinforcing threads are embedded, can be vulcanized.

One of the following methods is commonly used to vulcanize the semi-finished products.

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Each semi-finished product is first placed on a metal core, which is also assigned the task of Dimensional changes of the tube during the vulcanization step to prevent.

The tubes mounted on the cores are then introduced into an autoclave, inside which more saturated Steam or other heating fluid at a predetermined temperature and pressure and over a circulating for a predetermined period of time sufficient to allow the composition to vulcanize respectively. Finally, the hoses pulled from the autoclave are removed from their respective Cores separated.

Another method is to obtain the heat necessary to vulcanize the semi-finished products by Warm air or smoke gases are circulated inside an oven in which the semi-finished products that still sitting on the respective cores, were arranged.

According to a third procedure, this heating is carried out, by immersing the semi-finished products and their cores in a bath of molten salts being held.

The above methods have certain disadvantages. The first two can be seen in that relative long vulcanization times are required due to the low temperature of the heating fluid (steam) or due to the low heat transfer coefficient between the eluid (fuel gas) and the semi-finished product forming rubber composition.

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This leads to the fact that the number of cores that is necessary to produce a preset production of Getting articles in the unit of time is relevant. In addition, because the heating of the semi-finished product essentially through the effect of the thermal energy transferred by the heating device takes place through the thickness of the semi-finished product, it is not uniform; it follows from this, that, while the mean temperature of the cores is relatively low, the postponement of the unvulcanized Semi-finished product on the core becomes difficult and the shrinkage of the vulcanized semi-finished product is quite high.

In order to be able to continue to carry out these processes, it becomes necessary to have expensive systems of considerable dimensions (Autoclaves or ovens) to provide, which means high costs in terms of operation and maintenance, namely due to the low output and the complexity of the systems themselves.

Furthermore, it must be taken into account that the main phases (installation and removal of the semi-finished products regarding the cores, introduction and removal of the latter in relation to the autoclaves) in the above procedures, if done by hand, as is usually the pail, to a further increase in process time and the cost of the articles so obtained; they are carried out with the help of a machine park they complicate the system necessary to carry out the processes.

Finally, the environmental conditions under which

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the processes are carried out "particularly be inconvenient due to the heat and R _a uchgase which immediately adjacent to the zones of the plant circulate.

The third method mentioned makes it possible to eliminate some of the disadvantages mentioned above, since it a reduction in vulcanization times (due to the higher heat transfer coefficient between the heating fluid and the semi-finished product) and gives the opportunity to more easily attach the non-vulcanized semi-finished product on the Core and the removal of the vulcanized semi-finished product from the latter (due to the higher Temperature of the core); however, this method requires expensive equipment and additional work steps for washing the articles in order to be able to do so to eliminate salts deposited in the vulcanizing apparatus.

There is now a method for vulcanizing a tubular semi-finished product made from unvulcanized Rubber are proposed in which the above-mentioned disadvantages do not occur.

Furthermore, a device for carrying out this method is to be proposed.

The method according to the invention, in which during the vulcanization step the semi-finished product is placed on a core set so that there is substantial contact between its inner surface and the outer surface of the core is characterized by the fact that the necessary to Tulcanize the semi-finished product Heat energy from the inside of the core

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is delivered, the semi-finished product thermally against its environment by means of an insulating cover is isolated, which is at least partially arranged around this semi-finished product and this core.

An example embodiment of the invention will now be described in more detail with reference to the accompanying drawings are explained in which:

Pig. 1 is a front view of part of the device in a first working position shows;

Pig. 2 shows a section through a vulcanizing unit, which is part of the device after Pig. 1 forms namely in ·. open position; and

Pig. Figure 3 shows the part of the Pig device. I. in a second working position;

Pig. 4 gives a section through the vulcanizing unit the pig. 2 in the closed position or working position and with a semi-finished product applied to it again;

Pig. 5 shows in detail on a larger scale Units of the Pig. 2 and 4 »and the

Pig. 6 and 7 each show a plan view and a section through a tool for cutting the vulcanized semi-finished products, as part of the device.

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The method according to the invention, the phases of which will be considered in the following, can be carried out with a device that is partially in Eig. 1 and 5 of the type shown. The device has essentially a plurality of vulcanizing units, each of which is designated as a whole by the reference number 1 and each of which is capable of vulcanizing a tubular semi-finished product (Mg. 5 and 4), which in the illustrated embodiment is formed so that it comprises two curved parts and has a substantially constant diameter; this final product, which is a usual hose for motor vehicle radiators, is preferably with reinforcing thread 3 (3? ig. 4) Mistake.

Each vulcanizing unit 1 essentially comprises one

metallic core 4 (I ¹ Ig. 2) tubular shape, which is cantilevered at one of its ends 5 with respect to a carrier plate 6. The outer surface 7 of the core 4 has a shape and size which are substantially the same as those of the inner surface of the vulcanized hose.

The core 4 (Fig. 2) is provided with a closing element 8 in order to form an inner cavity 9 which is partly occupied by a small tube 10 for the supply of the heating fluid; this small tube is attached to the plate 6 at one of its ends. The lower end of the core 4 is connected by means of a ring 11 (Hg. 5) and a collar 4a integral with the core itself to a bushing 12 which in turn is connected to the plate 6. The small tube 10 stands over a hole. 12a in the socket in hydraulic connection

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with a suitable source of this fluid (not shown) · "

Outlet holes 12Td received in the sleeve and in the core 4 allow the heating fluid to exit. (or its condensate) so that there is an ITuid circulation occurs within the cavity 9.

At its end 5, the core 4 carries a ring element 13 (Pig. 2), which is a carrier for the semi-finished product 2 ″ and in turn are supported on a shoulder 14 of the core itself target.

This single element is zx ^ angular with an edge 13a provided such a size that it can accommodate one end of the semi-finished product itself on its inside can.

A second annular element 13 analogous to the first (Pig. 4) is intended to be placed on the other end of the To be stored core 4 and to come into contact with the other end of the semi-finished product 2. The surface of the closing element is expediently shaped, for example as a cone, so that simple management of the semi-finished product 2 to the core becomes possible.

Each vulcanizing unit also has a shell 16 (FIGS. 1 to 4) which completely surrounds the core 4 surrounds; it can be in the form of a bell, open at the bottom, and provided with an end edge 17

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which is suitable with the plate 6 (Fig. 4)
To come into contact and to form a substantially tight cavity 18 with this. This coat can consist of a first in the pig. I and 2 shown position in which the core 4 is left naked, move into a second position (shown in FIGS. 3 and 4) in which they move over this core to form the cavity
18 is arranged. This movement is regulated by actuating devices, for example a fluid dynamic double-acting cylinder 19 which is supported by arms 20 which are integral with the plate 6.

The walls of the shell 16 must be designed so that they do not allow any transfer of thermal energy from the cavity 18 to the environment; They are expediently made up of one or more layers of insulating material, for example a layer of glass wool 21,
which is located between a pair of walls 22 and has the effect of mechanical strength, for example a pair of walls made of sheet metal. Appropriately, but not necessarily, the jacket 16 contains a heating element 23, for example a tubular coil for circulating the heating fluid around which the / ^. can act the same fluid that is given to the cavity 9 of the core 4 through the small tube IO.

The device described also includes a tool shown in FIGS. 6 and 7, which
is able to perform the cutting of one end of the semi-finished product 2.

This tool comprises a sleeve 24 (Fig. 7), the
is performed on the .obere end of the core 4, with the
a ring gear 25 is integrally formed, which is thereupon by means of a tongue 26 and an elastic ring 27

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is stored.

On the sleeve or sleeve 23, a collar 28 is rotatably mounted, on which a lever 30 by means of a pin 29 pivoted. The end of an arm 31 of this lever rotatably carries thereon a pin 32 on which a gear wheel 33 is fixed, which is able to mesh with the ring gear 25; the end of the arm this Lever also carries a cutting tool 34, which is essentially designed as a disc and capable of being brought into contact with the semi-finished product 4 will.

An actuating handle 35, which is provided with a nut thread 36, is rotatable on the upper part of the sleeve 24 is, with which a threaded pin 37 meshes, the lower end of which is able to press against the locking Element 8 to be attached; this pin, which can move freely axially, is prevented from to turn with any equipment.

The method carried out with an apparatus of the type described above is carried out as follows.

A semi-finished product 2 (Fig. 4) of tubular shape made by the normal procedures with a rubber composition is made with embedded reinforcing threads 3 is in each vulcanizing unit 1 in the open state and with the jacket 16 raised in the pig. 1 and 2 position shown stored; the semi-finished product is introduced from the upper end of the respective core 4 by causing it to be on the surface 7- slide this core. The outside diameter of the semi-finished product is after being inserted into the Core 4 slightly larger than that of the ring edge 13a of the

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annular element 3. The underside of the semi-finished product 4 is first brought into contact with the annular element 13 and then the other becomes annular Element 13 in contact with the top of the semi-finished product, as shown in Fig. 4, brought.

Then the shell 16 of the unit is lowered by actuating the associated cylinder 19, whereby the cavity 18 is closed substantially tightly. Then the cavity 9 of the core 4 with heating fluid (for example saturated steam) · acted upon through the small tube 10, which inside the cavity is to circulate; the condensate flows out of the outlet holes 12b alone or with water vapor.

According to an alternative solution, a continuous circulation of the irritant fluid within the cavity 9 can be provided instead of this circulation only during each vulcanization step of the semi-finished product to be provided.

In addition, the temperature of the fluid can be adjusted accordingly the vulcanization time vary so that Vulcanization processes are carried out during which each the temperature is varied in a predetermined manner as a function of time.

Due to the structural arrangement described above, the heating fluid flow runs within the cavity 9 between the outer wall of the small tube 10 and the inner wall of the core 4 essentially in one direction, so that the formation of air pockets within the cavity is prevented. The inside the cavity 9

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Circulating water vapor quickly heats first the core 4 and then the semi-finished product 2 due to the high value of the heat transfer coefficient between the fluid and the core and between the latter and the semi-finished product. The heat transferred from the semi-finished product to the air of the cavity 18 within the shell 16 brings the air itself within a short time to a temperature which is essentially equal to that of the water vapor, so that all parts located within the cavity quickly reach such a temperature. It follows that the semi-finished product 2 is uniformly heated to the same temperature, thereby terminating its vulcanization. Using steam at a temperature between 180 and 23O ⁰ C is reached (on the assumption that it consists of a radiator hose for motor vehicles), the vulcanization in a time interval of 1 to 3 minutes.

The envelope or jacket 16, the walls of which are insulating, prevents the one supplied to the product 2 from being removed Heat energy is transferred to the environment. This goal is made better by the action of the thermal energy reached, which from the heating element 23 to the in the cavity 18 contained air is transmitted.

At the end of the vulcanization phase, the cylinder 19 is actuated again and moves the jacket 16 into a raised position Position (see Pig. 1 and 2). At this moment, the upper ring element 13 can be detached from the core 4 and the now vulcanized semi-finished product can be peeled off from the core itself. This process is easy as the vulcanization shrinkage is almost the same ITuIl is due to the fact that the temperature of the

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Zerns 4 in the v / es, equal to that of the vulcanized Semi-finished product is.

It will be clear that the device described also includes means for moving each core 4 with respect to the corresponding one Sheath 16 may have so that the removal of the semi-finished product from the core itself facilitates will.

The machining of the flat end surfaces of the vulcanized finished product is found to be favorable, even if reinforcement thread 3 has been worked into the semi-finished product, because these surfaces, which lean on the annular element 13, substantially flat and smooth during the vulcanization process even if the respective areas of the unvulcanized semi-finished product are quite were irregular.

This smoothing effect can be even better if before Vulcanizing the semi-finished product 2, the ring members 13 are rotated; by means of this rotation namely, the possible irregularities in the end faces of the semi-finished product eliminated.

The edges 13a of the elements 13 perform a correct finishing effect on the semi-finished product, making it possible to access the. End parts of the vulcanized Semi-finished product with exact dimensions and a good surface finish. to reach; in itself as is known, clamping devices should be provided on these end portions when the vulcanized Product a radiator hose for motor vehicles

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- 13 should.

In order to improve this finishing effect, axial grooves (not shown) can expediently be added provided on the inner surfaces of the edges 13a; these grooves allow for what is provided in excess Material of the semi-finished product to occupy its inside and to partially or completely fill it; in this way the grooves form a collection chamber for

the excess material of the semi-finished product and allow both an easier introduction thereof to achieve within the edges 13a as well as more precise dimensions of these end parts of the semi-finished product.

In order to improve the finishing of the end faces of the vulcanized product, the tool after the pig. 6 and 7 can be used appropriately.

This tool is inserted with Seäer sleeve 24 (Pig. 7) placed on the core 4; the axial position of the sleeve or sleeve with respect to the semi-finished product 2 is adjusted by rotating the handle 35 which moves the pin 37 axially. By rotating the Lever 30 causes the gear 33 to mesh with the ring gear 25 and calls the rotation of both the Gear (and thus the tool 34) and the collar 28 around the axis of the sleeve or sleeve 24 out. In this way, an end part of the semi-finished product 2 can be cut.

The method described therefore makes it possible perfectly finished articles with good surface properties within a greatly reduced time

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range.

In addition, the device required to carry out this method is very simple and inexpensive.

Furthermore, the manual operations associated with this embodiment of the method are greatly reduced and much easier (especially that of introducing the non-vulcanized semi-finished product on the core and that of removing the vulcanized semi-finished product from the core), compared to those that were necessary with known methods.

Since there is no circulation of iTuiden and Warmth in the room where the process takes place, one obtains favorable working conditions.

The measures described according to the invention can be used to vulcanize semi-finished products from a Shape different from that of the semi-finished product 2 can be used. This is how it can be the number of bends in the semi-finished product as well as the two lengths of the semi-finished product and a curved angle formed differently Be: in addition, it is possible by means of the method described, advantageously also semi-finished products vulcanize formed by parts of different diameters.

Changes and modifications are within the framework of the invention.

Claims: - 15 -

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Claims (22)

Folder: 9869 - 15 CLAIMS 1. Method of vulcanizing a tubular Semi-finished product made of non-vulcanized rubber, "in the case of the semi-finished product during the vulcanization stage is guided on a metal core in such a way that there is essentially a contact between its inner surface and the outer surface of the core, characterized in that the for vulcanizing the Semi-finished product necessary energy is supplied from the inside of the core, this semi-finished product is thermally isolated from its surroundings by an insulating jacket, which is at least partially is arranged around this semi-finished product and this core, such that the semi-finished product is brought to the core temperature substantially during the vulcanization process. 2. The method of claim 1, wherein the vulcanizing the semi-finished product is obtained by the action of a heating fluid, characterized in that that the heating fluid is caused to circulate in at least one cavity created within the core. 3- The method of claim 2, wherein the heating fluid Steam is characterized in that this circulation of the fluid is carried out by at least one steam supplying channel in connection with a steam source and through at least one channel for discharging the Steam condensate and the steam is obtained. 4. The method according to any one of the preceding claims, characterized in that each of these cores to one its ends is held attached to a support plate. - 16 A09851 / 0685 5. The method according to claim 4, characterized in that the jacket is designed as a bell so that it from a first position, in which the corresponding core is left naked, to the semi-finished product to be able to push this core, moves into a second position in which it is in contact with this Carrier plate stands to form a cavity within which this core and the respective semi-finished product are arranged. 6. The method according to any one of the preceding claims, characterized in that during vulcanization of the semi-finished product, thermal energy is also supplied within the jacket. 7. The method according to claim 6, characterized in that the "thermal energy within the jacket by a Heat exchanger is supplied in which this heating fluid circulates. 8. A method of vulcanizing a tubular semi-finished product made from unvulcanized rubber, in which the semi-finished product is pushed onto a metal core during the vulcanization process is maintained that there is substantial contact between its inner surface and the outer surface of the Core is maintained, characterized by devices for supplying the necessary thermal energy such that the semifinished product can be vulcanized within the respective core (4-); and by means (16) that transfer this thermal energy to the environment of the semi-finished product and core prevent, in such a way that during the vulcanization this semi-finished product substantially on the temperature of the core is brought. 409851/0685 -. 17 - 9. The device according to claim 8, wherein the vulcanization of the semi-finished product by the action a heating fluid is obtained, characterized in that these means for supplying thermal energy at least one cavity within the respective core comprise in this core in hydraulic communication with a source of this heating fluid. 10. The device according to claim 9> wherein this heating fluid Steam is characterized in that this core is substantially tubular with a cavity Shape is provided and a small pipe (10) in connection with a steam source eibhalt, at least a channel (12) is provided for discharging the steam condensate and the steam. 11. Device according to one of claims 8 to 10, characterized in that one end of each of these cores is attached to a carrier plate®. 12. Device according to one of claims 8 to 11, characterized in that each of these cores with a first support element is provided which is designed so that it is a support for one end of this semi-finished product forms. 13. The apparatus according to claim 12, characterized in that this first carrier element consists of one on this The core is movable ring and is designed so that it is thereupon in a predetermined axial position is stopped. 14 · Device according to one of claims 8 to 13, characterized in that each of the cores with a second carrier element is provided with such a design, 409851/0685 - 18 - that it is placed on the respective core and brought into contact with the other end of the semi-finished product can be. 15. Device according to one of claims 12 to 14, characterized in that each of the carrier elements is provided with an annular edge, on the inner surface of which axial grooves are provided. 16. Gate direction according to one of claims 8 to 15, characterized in that these devices for Preventing the transfer of thermal energy to the environment of the semi-finished product and the core of a bell with insulating walls that are movable from a first position in which they hold the respective core left naked, is in a second position in which it is in contact with this carrier plate and forms a cavity within which this core and the respective semi-finished product are arranged are. 17. Device according to one of claims 8 to 16, characterized in that this device for Preventing the transfer of heat to the surroundings of the semi-finished product and core, in addition within this Have jacket arranged heating devices. 18. The device according to claim 17, characterized in that these heating devices are a heat exchanger, in which this heating fluid circulates. 19. Device according to one of claims 8 to 18, characterized by a tool for. Cutting off one - 19 409851/0685 End, of the semi-finished product, which is placed on the upper The end of the core is insertable. 20. The device according to claim 19 »characterized in that that the tool has a fastener that can be pushed onto the end of the core, comprises a support element rotatable about the axis of the fastening element and a cutting element which is rotatable about this rotatable carrier element in such a way that the semi-finished product is cut through; and by means of driving this tool in rotation when this rotatable Trägeirfement in Rotation is offset. 21. The device according to claim 20, characterized in that these devices for taking away this Tool in rotation with a fixed ring gear to the fastening element, a hand-operated lever that on the support element pivoted and carries the rotatably mounted tool on one of its arms as well as a 'gear wheel, which with the ring gear due to this lever actuation fixed with the tool combs. 22. Method of vulcanizing a tubular Semi-finished product made from non-vulcanized Rubber and device for carrying out this process, essentially as described and shown. PAtSMTANWALTE DMW. H. PiNCKS, DIPL-WG. H. BOHC -—— WPWNG.S.STA6GÜI 409851/0685 Blank page