WO2003061952A1

WO2003061952A1 - Clamping mechanism for vulcanizing mold

Info

Publication number: WO2003061952A1
Application number: PCT/IT2003/000014
Authority: WO
Inventors: Tiziano Galicani; Daniele Brogi; Massino Capecchi
Original assignee: Cima Impianti S.P.A.
Priority date: 2002-01-23
Filing date: 2003-01-17
Publication date: 2003-07-31
Also published as: ITFI20020015A1; TW200302159A

Abstract

A moving element (18) with an upper half-mold (20) can be raised from a base structure (1) with a lower half-mold (7) by means of vertical guides (24, 26, 28); retaining bars (53) are pivoted (51) on said base structure (1) and made to oscillate between an opened-out position for opening the mold and a vertical position in which they are brought toward each other so that the head (53A) of each bar engages in a corresponding seat (55) formed in the moving element (18) when the latter is lowered.

Description

CLAMPING MECHANISM FOR TIRE VULCANI ZING MOLD

DESCRIPTION

The invention relates to a vulcanizing machine for producing tires for road vehicles and other vehicles, comprising a mold with lower components carried by a base structure and upper components carried by a moving element which can be raised to open the mold and lowered to close the mold.

More particularly, the invention relates to means for locking the components of the mold when it is closed and for unlocking them to permit the opening of the mold and the operations of removing the vulcanized tire and inserting a tire to be vulcanized.

The. invention essentially comprises:- vertical guide means for said raisable and lowerable moving element; retaining bars, each pivoted on said base structure and able to oscillate between an opened-out position for opening the mold and an essentially vertical position in which they are brought toward each other so that their heads engage in corresponding seats formed in the moving element when it is lowered, thus forcing the element into the configuration in which the mold is closed; and means for forcing said retaining bars to close the mold, and means for opening out said retaining bars.

Said means for forcing said retaining bars to close the mold and said means for opening out said retaining bars can comprise a ring housed slidably on the base structure and an actuator to cause the angular sliding of said ring in two opposite directions; and, on said ring, cam means for forcing said retaining bars downward to close the mold and cam means for opening them out against an opposing elastic force. The bars can be pivoted on pins which can be lowered.

The head of each retaining bar can be adjustable, to ensure the correct simultaneous operation by all the bars. The vertical guide means can comprise rails and pairs of wheels interacting with said rails, and cylinder and piston systems which can be activated simultaneously. The arrangement of the bars could be reversed, while providing the same functions.

The invention will be more clearly understood from the description and the attached drawing, which shows a practical and non-restrictive example of the invention. In the drawing,

Fig. 1 shows a view in partial section, taken approximately through the line l-l of Fig. 5, of a vulcanizing machine with the mold open; Figs. 1 A and 1 B show two details of Fig. 1j

Figs. 1 C and 1 D show, in a similar way to Fig. 1 B, two successive configurations of the components illustrated therein;

_Fig._2 shows a view and partial section, essentially taken hrough ll-I.IJn. Fig. 5, in the open mold configuration of the machine;

Fig. 3 is similar to Fig. 2, but shows the machine in the closed mold configuration as in Fig. 1 C; Fig. 4 shows a section similar to that of Fig. 1 , with the mold closed;

Fig. 5 shows a view from above, essentially from the line V-V of Fig. 1 ; Figs. 6, 7 and 8 show a partial view taken through the line VI-VIII of Fig. 1 , looking upward from the base, showing the means for opening out the locking bars and for forcing them, in three views showing different stages of separation, from the start of the operation of bringing the bars toward each other and in the conditions of the locking of the bars once brought toward each other to ensure the closing of the mold;

Figs. 9, 10 and 11 show a local view through IX-IX in Fig. 3, enlarged, a section through X-X, and a view from the line XI-XI of Fig. 9; Figs. 12 and 13 show, in two positions, a device for fixing the upper component of the mold to the raisable moving element and for releasing it therefrom.

The attached drawing shows a vulcanizing machine with a mold of the type which can be opened by raising the upper part of the mold and by opening out the perimetric sections of the mold which form the tread with an arrangement for sliding along inclined lines along the generating lines of a frusto-conical surface. The number 1 indicates the base structure of the machine, part of which consists of an essentially square block 3 with rounded corners (see also Fig. 5), on which is mounted a ring 5 with a frusto-conical inner wall to receive mold sections 7 which form the tread part of the tire to be vulcanized. The number 9 indicates a heating annular element (used where electric heating is employed) of the mold. The sectors 7 are guided conically by the ring 5 and slide on a support 12, which in turn is vertically guided (see Figs. 1 to 4) by columns 14 and is raised and lowered by actuators 16, which thus provide the closing and opening movements of the sectors 7 by vertical movement with respect to the ring 5. This arrangement is essentially known. The number 18 indicates a moving element which can be raised to open the mold and lowered to close the mold; said moving element J 8 carries the component 20, 20A of the mold, which completes the mold which is additionally formed by the component 20B and by the sectors 7 with the corresponding completion shells for shaping the tread and sidewalls of the tire. The component 20 of the mold is carried by a block 22 shaped essentially in the same way as the block 3 and thus being essentially square with rounded corners (see also Fig. 5).

The upper components 20, 20A and the lower components 7, 5, 20B make up the mold, which is replaceable; they can be joined together and ' stored for replacement with another mold. Further elements can be replaced as required for the mold which is installed at any particular time. Suitable joining means - such as those shown in Figs. 10 and 11 - are provided for the fixing and release and replacement of the molds.

The moving element 18 is provided with two essentially box-shaped guide sections 24, each provided with dihedral guides 24A (Figs. 1 , 2, 4 and 5), which interact with wheels 26 mounted on walls 28 forming part of the base structure 1. Inside the box-shaped sections 24 there are two corresponding cylinder and piston systems 30, which operate between the base structure 1 and the moving element 18 so that they act simultaneously to raise and lower the moving element 18 with respect to the base structure 1.

The moving element 18 is additionally provided (see Figs. 1A and 1 B) with devices which are coaxial with the component 20 and which are indicated in a general way by 32, these devices forming centering systems for the tire P to be enclosed in the mold which is formed by the sections 7, by the component 20 and also by the opposing lower component 20A. Next to said lower component 20A of the mold there is an assembly, indicated in a general way by 34, which is designed to create an internal counter-pressure in the tire P to be vulcanized; this assembly comprises a bladder 34A and other components, including a cylinder and piston system 34B for raising and lowering the assembly 34. The parts 32 and 34 of the vulcanizing machine will not be described further, since they are essentially equivalent to those of a machine described in the co-pending international application PCT/IT02 00542,„file.d_August_19, 2002_held_by-J ιe same...applicant. The devices for transferring the green tire P from a conveyor to the mold and for collecting the vulcanized tire from the open mold are also of a known type, for example the type described in the aforesaid co-pending application and shown schematically in Figs. 1 , 1A and 1 B, 4 and 5. In particular, the number 38 indicates in a general way a device which serves to receive the green tire and which can be removed by an arm 40 pivoted at 42 when the mold has to be replaced. The green tire is transferred from said device 38 to a position coaxial with the mold by means of a tray 14, with an annular supporting seat, carried by an arm 44A which can be raised and lowered by a unit 44F and 44C, and which can also be moved angularly by the actuators 44E and 44D, so that the green tire can be picked up and transferred into the mold, which is open and has its sections 7 opened out, in order for the tire to be received and enclosed in the mold and vulcanized. The invention relates to an arrangement, provided in a vulcanizing machine such as that briefly described above, or other equivalent type, to join the lower group of components 5 and 7 of the mold to the upper group 18 and 20 which closes the mold by the lowering of the moving element such as that indicated by 18 or an equivalent. For this purpose, bars 53 are pivoted on the base structure 1 about corresponding pins 51 supported by elastic brackets 52, these bars being tiltable in radial planes between a position in which they are opened out as shown in Fig. 2 and a position in which they are brought toward each other by the elastic action of springs 65 and are essentially vertical, as shown in Fig. 3, the bars 53 in the latter position being capable of locking the moving element 18 when it is lowered from the configuration of Figs. 1 and 2 to the configuration of Figs. 3 and 4. The block 3 has radial recesses 3A next to the bars 53, into which the corresponding bars 53 can penetrate when they are brought toward each other in the configuration of Fig. 3.

Each of the bars 53 has a terminal head 53A, which is used for locking and whose position can be adjusted by means of a nut and locknut arrangement on the end of each bar. The block 22 of the moving element 18 has radial seats 55 facing .the recesses 3A, ihese__seats_being_„capable of receiving the parts of the corresponding bars 53 adjacent to the heads 53A of said bars; each head 53A is brought immediately above the seats 55 of the block 22 of the moving element 18 after the latter has been lowered to the closing position, as shown in Fig. 3.

The assembly described below is provided to act simultaneously to move the bars 53 angularly between the opened-out configuration shown in Fig. 2 and the configuration in which they are brought toward each other as shown in Fig. 3, and to lock the mold in the closed position. An annular seat is formed on the block 3 of the moving element 1 for the angular sliding of a ring 57 which can be moved between two terminal angular positions which are shown, in particular, in Figs. 6 to 8. This angular movement of the ring 57 is produced by an actuator 59 which is particularly clearly visible in Figs. 5 to 8; the actuator 59, in the form of a cylinder and piston, is pivoted at 59A on a projection of the ring 57 and at 59B on a bracket 61 (see Fig. 5) projecting from the base 1. The ring 57 has four cam profiles 63, which can be moved by the ring 57 in the direction of the arrows f63 from a position remote from the bars 53 (see Fig. 8) to a position next to the bars 53 (Figs. 2, 5 and 6), passing through an intermediate approach position shown in Fig. 7. As they pass from the position of Fig. 7 to the position of Fig. 6, the cam profiles 63 act on rings 53B carried by the corresponding bars 53, thus causing an outward movement, in other words a movement toward the opened-out configuration of the bars 53, as shown in Fig. 2, from the configuration in which the bars are held elastically within the recesses 3A and the radial seats 55. When the ring 57 is rotated by the actuator 59 in the direction opposite that of the arrows f63 and is moved from the configuration of Fig. 6 to the configuration of Fig. 7 and then to the configuration of Fig. 8, the elastic force - imparted by the extension springs 65 or equivalent elements - initially returns the bars to the vertical configuration shown in Fig. 3 from the opened-out configuration of Fig. 2. The bars 53 are then made to impart a force in the direction f53 to the moving element 18 to ensure the clamping in the closed position between the upper components 20 and 20A and the lower components.5, 7 and.20B. To achieve this clamping in- the direction f53,-each of the bars 53 is provided with a nut 66 which is integral with the bar and which has its upper surface 66A inclined tangentially with respect to the shape of the ring 57. Said ring 57 is integral with curved cam profiles 67, each of which has on its lower side a surface 67A whose inclination matches the inclination of the surface 66A of the nut 66. As the ring 57 moves in the opposite direction to the arrows f63, the surfaces 67A of these curved cam profiles 67 engage with the surfaces 66A of the nuts 66, and push them downward in the direction f53 so that the pivots 51 carried by the elastic brackets 63 are made to yield elastically; the heads 53A of the bars 53, inserted in the seats 55, consequently act on the assembly of the moving element 18, thus forcing the mold into the closed configuration. As the ring 57 is rotated in the direction of the arrows f63 by the actuator 59, the curved cam profiles 67 are disengaged from the bars 53; the action of the cam profiles 63, which are wedged from inside onto the bars 53, cause the bars to be opened out.

The bars 53 can be of cylindrical shape, with flats, if necessary, in the areas which are to be received in the recesses 3A and if necessary also in the seats 55. When the mold is reopened, after the bars 53 have been opened out from the configuration of Fig. 3 to the configuration of Fig. 2, the vulcanized tire P1 (see Fig. 5) is lifted by the device 32 and can be picked up by a discharge device 70, 72 (see Figs. 1A, 1 D and 5) which transfers it from the position coaxial with the mold to the outside of the machine, so that the tire can be received by a suitable conveyor and sent for further processing.

The positions of the heads 53A of the bars 53 can be adjusted, to provide minimum play between the heads and the block 22 of the moving element 18 which is lowered to close the mold when the bars 53 are brought together in the locking position.

Figs. 1 , 1A and 4, and the detailed views in Figs. 12 and 13, show devices 80, 81 for fixing the component 20 of the mold to the moving element 18 and releasing it therefrom, to allow this component to be connected to the lower part 5, 7. 20 of he_mold_for.. replacement.. Each of these devices 80,-81 comprises a lower elastic clamp 81 with springs 83 which, by reacting against the block 22, act on a rod 85 with a conical end which can open out fins 87 against a corresponding conical seat formed in the support 20A of the upper component 20 of the mold (Fig. 12). Each device comprises an actuator 80, having a pusher 80A acting on the upper end 85A of the rod 85, in opposition to the spring 83, to slacken the grip of the fins 87 on the corresponding seat formed in the support 20A (see Fig. 13), in order to allow the connection of the mold assembly which is to be replaced. Similar devices to the devices 80, 81 are provided for fixing the lower components of the mold to the base 1 and releasing them therefrom. The upper and lower components of the mold to be replaced can be connected to each other, which facilitates the replacement operations and storage. The heating unit 9 can be stored with the mold, forming a container for the mold. Clearly, the drawing shows only a simplified representation, provided solely as a practical demonstration of the invention, this invention being variable in its forms and arrangements without departure from the scope of the guiding concept of the invention. The presence of any reference numbers in the attached claims is intended to facilitate the reading of the claims with reference to the description and to the drawing, and does not limit the scope of protection represented by the claims.

Claims

1. Machine for vulcanizing tires for road vehicles and other vehicles, comprising a mold with lower components (5, 7, 20B) carried by a base structure (1) and upper components (20; 20A) carried by a moving

-5 - element (18) which can be raised to open the mold and lowered to close the mold, characterized in that it comprises: vertical guide means (28, 26, 24) for said raisable and lowerable moving element (18); retaining bars (53), each pivoted (at 51) on said base structure (1) and 0 able to oscillate between an opened-out position, for opening the mold, and an essentially vertical position in which they are brought toward each other so that the head (53A) of each bar engages in a corresponding seat (55) formed in the moving element (18) when it is lowered, and in which the element is forced into the configuration in which it closes the mold; 5 - means for acting on said bars (53) to force them to clamp the mold in the closed state; and means (57, 63, 67) for forcing said retaining bars to open out (53).

2. Machine according to Claim 1 , characterized in that said means for acting on said retaining bars (53) comprise a ring (57) movable angularly 0 in a seat of said base structure (1) and cam profiles (67) on said ring, for acting axially on shoulders (66) of the bars (53).

3. Machine according to Claim 1 or 2, characterized in that elastic means (65) are provided for opening out said retaining bars (53).

4. Machine according to Claim 2 or 3, characterized in that cam 5 profiles (63) for opening out said retaining bars (53) are provided on said ring

(57), which is slidably supported on the base structure (1).

5. Machine according to Claims 2 to 4, characterized in that it comprises an actuator (59) for making said ring (57) slide angularly in two directions, to activate said cam profiles (63, 67) in order, respectively, to open 0 out and to force said bars (53).

6. Machine according to at least one of the preceding claims, characterized in that the head (53A) of each retaining bar (53) is adjustable.

7. Machine according to at least Claim 1 , characterized in that said vertical guide means comprise dihedral rails (24A) and pairs of wheels (26) interacting with said rails, and cylinder and piston systems (30) which can be activated simultaneously.

8. Machine according to Claim 1 at least, characterized in that it comprises devices (80) and corresponding actuators (81) for fixing the components of the mold to the base (1) and to the vertically moving element (18), and for releasing them from said base and from said moving element, to facilitate the operations of replacing the mold.