DE102016217588A1 - Process for bellows-free vulcanization and multi-part vulcanization mold for it - Google Patents

Abstract

Method and multi-part mold for the bellows-free vulcanization of a blank of a toroidal elastomeric body, preferably a substantially cylindrical or conical air spring bellows, wherein the blank is positioned in an inner annulus of a multi-mold, closable vulcanization mold and then vulcanized, the blank initially on a inner protrusion or extension of a molded part is pushed, then the other mold parts are moved together to form the blank receiving annular space to a closed Vulkanisationsform vertically and horizontally, after which the blank surrounding moldings are heated and the blank by heat transfer and spewing excess material in the Annulus is vulcanized, and wherein after the vulcanization, the moldings are driven up and the vulcanized elastomeric body is removed.

Description

The invention relates to a method for the bellows-free vulcanization of a blank of a toroidal elastomeric body, preferably a substantially cylindrical or conical bellows. Also disclosed is a multi-part vulcanization mold for carrying out the process.

In the vulcanization of hollow bodies of elastomeric materials, such as tires, toroidal bellows, etc., it is common that the hollow bodies are placed in a heating mold, which surrounds them from the outside, and are additionally supplied with heating medium from its inside to a uniform To achieve inside and outside and complete heating to vulcanization temperature. Depending on the elastomer / material vulcanization is carried out at a temperature between 160 and 200 ° C. In general, the vulcanization time, also depending on the material, about 6 to 12 minutes.

Depending on the nature of the workpiece to be vulcanized, the inside or the outside can be acted upon directly with a heating medium or provided with a support bellows / bladder which separates the workpiece to be vulcanized from the heating medium. The heating medium normally used is hot steam. The use of bladders is not without problems, since here a separate component must be maintained that due to heavy load has only a limited life.

By the heat transfer via an additional component of course, the energy consumption is higher. In addition, in the steam heating, especially in the filling of larger Balginnenräume, a complex line and valve system for the supply and removal of superheated steam required, which must be maintained accordingly.

However, a significant disadvantage of direct or indirect steam heating is that, according to the vapor pressure curve for water, the pressure of the saturated steam used is dependent on the temperature and thus vulcanization pressure and vulcanization temperature can not be set independently and arbitrarily.

Thus, the object of the invention was to provide a method and a vulcanization mold for bellows-free vulcanization for toroidal elastomeric hollow bodies, which permit simplified vulcanization with good energy utilization and independent setting of vulcanization pressure and vulcanization temperature.

This object is achieved by the features of the main claim. Further advantageous embodiments are disclosed in the subclaims.

• a) der Rohling zunächst auf einen zu seinem Innenraum komplementären, konzentrischen Vorsprung bzw. Fortsatz eines Formteiles aufgeschoben wird,
• b) dann die mehreren Formteile zur Bildung des den Rohling aufnehmenden Ringraums zu einer geschlossenen Vulkanisationsform vertikal und horizontal zusammengefahren werden,
• c) wonach ein oder mehrere den Rohling umgebende Formteile der Vulkanisationsform aufgeheizt werden und der Rohling durch Wärmeübertragung und unter Austrieb überschüssigen Materials im Ringraum vulkanisiert wird,

und nach der Vulkanisation die Formteile aufgefahren und der vulkanisierte elastomere Körper entnommen wird. Üblicherweise sind die Formteile solcher Vulkanisationsformen aus Metall.In this case, the blank is positioned in an inner annular space consisting of a plurality of moldings, closable vulcanization mold and then vulcanized, wherein

• a) the blank is first pushed onto a complementary to its interior, concentric projection or extension of a molded part,
• b) then the plurality of mold parts for formation of the blank receiving annular space are moved together to a closed mold vulcanization vertically and horizontally,
• c) after which one or more moldings of the vulcanization mold surrounding the blank are heated and the blank is vulcanized by heat transfer and expulsion of excess material in the annular space,

and after vulcanization, the moldings are driven up and the vulcanized elastomeric body is removed. Usually, the moldings of such vulcanization molds are made of metal.

The fact that in this method, the heat transfer is not directly by saturated steam, but by heating one or more moldings surrounding the blank and transfer their heat to the latter, avoids the inevitable according to the vapor curve dependence between pressure and temperature during vulcanization. You can control the pressure in Vulkanisationsraum / annulus by the collapse of the moldings and set the temperature regardless of the individual moldings. For this purpose, the moldings may contain channels in which steam is used as the heating medium. However, since there is no direct contact with the vulcanized blank, this is not subject to the above-mentioned dependence.

An advantageous development is that in the step a) the blank preferably by means of pressure medium, preferably compressed air, is acted upon on its inner side so that a slight camber of the blank takes place and a medium cushion between the inner wall of the blank and the outer wall of the Extension is built. This facilitates the introduction of the blank into the mold or the sliding / slipping of the blank on the molding, which fills its interior, ie on the projection or extension. The interior of the blank is now supported by a metallic part as a rule, which receives the blank from the inside and fills its interior, and no longer acted upon by steam or filled by a vapor-loaded bellows. The internal molding is then heated according to the method and then performs the heat required for vulcanization from the inside too.

A further advantageous embodiment consists in that, in the step b), the plurality of molded parts are moved together in a force-controlled manner vertically and horizontally. By means of such control, the corresponding pressure (vulcanization pressure) is applied to the blank to be vulcanized without the temperature having to be changed or increased. The dependence between temperature and vapor pressure is thus eliminated.

• a) ein vertikal in Richtung der Formenachse verfahrbares Formenoberteil mit einer konzentrisch innenliegenden Vertiefung zur Aufnahme des oberen Bereiches eines äußeren Formenmittelteils
• b) ein vertikal in Richtung der Formenachse verfahrbares, mehrteiliges torusförmiges äußeres Formenmittelteil, dessen Innenwandung die äußere Wand des Ringraumes zur Aufnahme des zu vulkanisierenden Rohlings bildet,
• c) ein Formenunterteil mit einem zum Torusinnenraum des äußeren Formenmittelteils komplementär ausgebildeten und in dem Torusinnenraum aufnehmbaren konzentrischen Fortsatz, dessen Außenwandung die innere Wand des Ringraumes zur Aufnahme des zu vulkanisierenden Rohlings bildet,

wobei das Formenoberteil, das Formenmittelteil und das Formenunterteil beheizbar ausgebildet sind, vorzugsweise mit Kanälen für ein Heizmedium versehen sind und zusammenwirkende Führungselemente aufweisen, vorzugsweise konzentrische konische Anlaufflächen, durch welche bei der vertikalen Bewegung zum Schließen der Form und zur Bildung des Ringraumes eine horizontale und auf den Fortsatz gerichtete Schließ- und/oder Kippbewegung des Formenmittelteils oder seiner Teile durchführbar ist.Particularly suitable for carrying out the method is a multi-part vulcanization mold whose multiple parts are formed complementary and for bellows-free vulcanization to form an annular space for receiving a blank to be vulcanized toroidal elastomeric body by a primarily vertical movement to a closed Vulkanisationsform be moved together. The vulcanization mold has the following parts:

• a) a vertically movable in the direction of the mold axis upper mold part with a concentric inner recess for receiving the upper portion of an outer mold center part
• b) a vertically movable in the direction of the mold axis, multi-part torus-shaped outer mold middle part whose inner wall forms the outer wall of the annular space for receiving the blank to be vulcanized,
• c) a lower mold part with a complementary to the Torusinnenraum the outer mold center part and can be accommodated in the Torusinnenraum concentric extension whose outer wall forms the inner wall of the annular space for receiving the blank to be vulcanized,

wherein the upper mold part, the mold middle part and the lower mold part are formed heatable, preferably provided with channels for a heating medium and having cooperating guide elements, preferably concentric conical ramp surfaces through which in the vertical movement to close the mold and to form the annulus a horizontal and on the extension directed closing and / or tilting movement of the mold center part or its parts is feasible.

With the vulcanization mold according to the invention and its horizontally and vertically movable parts / segments, it is then possible to exert a uniform pressure acting uniformly on all sides on the blank to be vulcanized, which is independent of the temperature of the heating medium.

An advantageous development is that the mold center part is divided horizontally and / or segmentally divided vertically. Such a multiple division facilitates the horizontal and vertical movement with which the individual parts of the vulcanization mold are closed. This is supported by a further advantageous embodiment, which consists in that the individual parts of the mold center part are mutually articulated and / or resiliently supported.

A further advantageous embodiment is that the segment-shaped vertical parts are tiltably mounted with respect to the concentric extension of the mold base and the tilting movement takes place about an axis perpendicular to the mold axis. This also supports the above-mentioned safe closure movement of the vulcanization mold and the application of a uniform pressure on the blank to be vulcanized.

A further advantageous embodiment is that the upper mold part or the lower mold part have a compressed air supply, can be introduced with the compressed air into the interior of the blank to be vulcanized or to its sliding onto the concentric extension between the outer wall of the extension and the blank to be vulcanized. Here, for example, in the case of a partially closed vulcanization mold, a so-called camber space can be provided for the blank in which the blank can easily be inflated and slip onto the molded part (projection or extension on the lower mold part) on its underside as the print medium emerges. which fills its interior.

A further advantageous embodiment is that the blank to be vulcanized, the annular space for receiving it and the extension are formed conically in the same direction with each increasing the diameter of the mold base. Conical bellows can be easily produced / vulcanized in this way.

A further advantageous embodiment consists in that the upper mold part, the middle mold part and the lower mold part have chambers or spaces for excess rubber ejection of the blank to be vulcanized, wherein the individual molded parts optionally cooperate to form the chambers or spaces. Thus, excess rubber leakage after vulcanization can be easily removed.

Reference to an embodiment, namely a vulcanization of the invention for bellows vulcanization of air spring blanks, the invention will be explained in more detail. The figures show schematically a vulcanization press to carry out the process for the vulcanization of air spring blanks. Show it

1 a vulcanization mold according to the invention in half section, on the left side in its closed state, on the right side in the open state

2 one of the 1 corresponding graphic representation in which the vulcanization form is seen on the left and right in different stages of the closing process

3 in one of the 1 and 2 corresponding graphic representation of the vulcanization mold in a closed position on the right side and just before the closure on the left side.

The 1 shows a vulcanization mold according to the invention in half section, on the left side in its closed state, on the right side in the open state.

The vulcanization press is shown in different phases of the loading and vulcanization process and consists here of top mold 1 , Mold middle part 2 and mold base 3 , All fittings are with channels 4 are provided for a heating medium, in this case superheated steam. The left side of the 1 represents a half-section of the vulcanization mold in its closed state, while the right side of the 1 uses the same form of representation for the individual parts of the vulcanization mold in the open state.

All of the individual molded parts are designed to be complementary and cooperating and to form an annular space for receiving a blank to be vulcanized 5 by an initially substantially in the direction of the shape axis 6 vertical movement can be brought together. The vertically movable in the direction of the mold axis upper mold part 1 is with a concentric inside recess 7 for receiving the upper portion of the upper outer mold center part 2 Mistake.

The multipart torus-shaped outer mold middle part 2 is vertical in the direction of the mold axis 6 movable, with its inner wall 8th the outer wall of the annular space for receiving the blank to be vulcanized 5 forms.

The mold base 3 has one to Torusinnenraum 9 the outer mold center part complementarily formed and accommodated in the Torusinnenraum concentric extension 10 on whose outer wall 11 forms the inner wall of the annular space for receiving the blank.

Mold top 1 , Mold middle part 2 and mold base 3 have cooperating, concentric tapered contact surfaces 12 . 13 as guide elements, through which in the vertical movement a horizontal and on the extension 10 directed closing and / or tilting movement of the mold center part 2 or its individual parts.

The mold middle part 2 is horizontally and / segmentally divided vertically, wherein the parts of the mold center part hinged and with spring elements 14 are supported against each other, so that the segment-shaped vertical parts are tiltably mounted with respect to the concentric extension of the lower mold part and the tilting movement takes place about an axis perpendicular to the mold axis. The spring elements 14 are in recesses of the individual parts of the mold middle part 2 arranged and support the individual parts or segments each spring against each other.

2 shows one of the 1 corresponding drawing representation in which the mold center part 2 already partially in the direction of the extension 10 ascended. The mold shell 1 has a compressed air supply not shown here in detail, with the compressed air in the interior 15 of the blank to be vulcanized or for its sliding onto the concentric extension 10 between outer wall 11 of the extension 10 and the blank to be vulcanized 5 can be initiated. This will make the interior 15 of the blank to be vulcanized to a so-called "bombage space", in the area of the blank receives a curvature to the outside. This facilitates the sliding of the blank 5 on the heatable molding / extension 10 which then fills the interior of the blank.

3 shows in a corresponding representation of the vulcanization mold in a closed position on the right side and just before the closure on the left side. Clearly recognizable here is the tilting movement of the mold center part 2 just before the closure. When closed, the top mold presses 1 The entire mold package with a defined force put together that excess rubber material gets into the designated chambers 16 expelled and regardless of the pressure prevailing in the mold, the heating can now take place.

LIST OF REFERENCE NUMBERS

1

Mold top

2

Form midsection

3

Mold part

4

heating duct

5

to be vulcanized blank of a toroidal elastomeric body

6

mold axis

7

Inner recess

8th

inner wall

9

Torusinnenraum

10

Projection / projection

11

outer wall

12

Upper contact surface

13

Lower starting surface

14

spring element

15

Interior / camber room

16

Excess rubber chamber / for rubber outlet

Claims (10)

Method for the bellows-free vulcanization of a blank ( 5 ) of a toroidal elastomeric body, preferably a substantially cylindrical or conical bellows, characterized in that the blank ( 5 ) is positioned in an inner annulus of a multi-mold, closable vulcanization mold and then vulcanized, wherein a) the blank first on a complementary to its interior, concentric projection or extension ( 10 ) of a molded part ( 3 ) is pushed so that the extension fills the interior of the blank, b) then the plurality of molded parts ( 1 . 2 . 3 ) to form the blank ( 5 c) whereafter one or more moldings surrounding the blank of the vulcanization mold are heated and the blank is vulcanized by heat transfer and expulsion of surplus material in the annular space, and after the vulcanization the moldings are raised and the vulcanized elastomeric body is removed. A method according to claim 1, wherein in step a) the blank is preferably acted upon by means of pressure medium, preferably compressed air, on its inside so that a slight camber of the blank takes place and a medium cushion between the inner wall of the blank and the outer wall ( 11 ) of the extension is constructed. Method according to Claim 1 or 2, in which, in step b), the plurality of molded parts are moved together in a force-controlled manner vertically and horizontally. Multi-part vulcanization mold for carrying out the method according to claim 1 to 3, whose multiple parts are complementary and for the bellows-free vulcanization to form an annular space for receiving a blank to be vulcanized ( 5 ) of a toroidal elastomeric body can be brought together by a vertical movement to form a closed vulcanization mold, characterized in that the vulcanization mold comprises the following parts: a) a mold upper part which can be moved vertically in the direction of the mold axis ( 1 ) with a concentric inner depression ( 7 ) for receiving the upper region of an outer mold middle part ( 2 ), b) vertically in the direction of the mold axis ( 6 ) movable, multipart torus-shaped outer mold middle part ( 2 ), whose inner wall ( 8th ) the outer wall of the annular space for receiving the blank to be vulcanized ( 5 ), c) a mold base ( 3 ) with a torus interior ( 9 ) of the outer mold middle part ( 2 ) formed concentrically and in the Torusinnenraum recordable concentric extension ( 10 ) whose outer wall ( 11 ) the inner wall of the annular space for receiving the blank to be vulcanized ( 5 ), wherein the upper mold part ( 1 ), the mold middle part ( 2 ) and the lower mold part ( 3 ) are formed heatable, preferably with channels ( 14 ) are provided for a heating medium and have cooperating guide elements, preferably concentric conical contact surfaces ( 12 . 13 ), by which in the vertical movement of a horizontal and the extension directed closing and / or tilting movement of the mold center part ( 2 ) or its parts is feasible. Vulcanization mold according to claim 4, wherein the mold center part is divided horizontally and / or segmentally vertically divided. A vulcanization mold according to claim 5, wherein the individual parts of the mold center part ( 2 ) are mutually articulated and / or resiliently supported, preferably arranged in recesses and acting between the individual parts spring elements ( 14 ). Vulcanization mold according to claim 5 or 6, in which the segment-shaped vertical parts with respect to the concentric extension ( 10 ) of the mold base ( 3 ) are tiltably mounted and the tilting movement about a perpendicular to the mold axis ( 6 ) axis. Vulcanization mold according to one of Claims 4 to 7, in which the mold top part ( 1 ) or the lower mold part ( 3 ) have a compressed air supply, with the compressed air into the interior ( 15 ) of the blank to be vulcanized ( 5 ) or for its sliding on the concentric extension between the outer wall ( 11 ) of the extension ( 10 ) and the blank to be vulcanized ( 5 ) is initiated. Vulcanization mold according to one of claims 4 to 8, in which the blank to be vulcanized ( 5 ), the annulus to its inclusion and the extension ( 10 ) are conically formed with each lower mold part ( 3 ) increasing diameter. Vulcanization mold according to one of Claims 4 to 9, in which the mold top part ( 1 ), the mold middle part ( 2 ) and the lower mold part ( 3 ) Chambers ( 16 ) or spaces for excess rubber ejection of the blank to be vulcanized.

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