EP0083518B1 - Deep slitting machine for making grooved wheels for air tyres from non plane blanks - Google Patents

Description

When it is desired to obtain, by deep splitting or slitting of the periphery of non-planar discs, wings of the same thickness or of different thickness so as to then conform these wings to finally obtain vehicle wheels each provided with a pneumatic tire , we quickly realize that deep splitting is very difficult if not impossible due to deformations of the flatness of the disc and internal tensions inherent in the material of the disc. In addition, the disc undergoes before the deep splitting of the deformations because the central web of the wheel is stamped in order to place the hub forming the wheel support and also to give this web of desired shapes in order to create, for example, a wheel of style.

There are already machines (see in particular FR-A-1 514 582) which make it possible to split the peripheral part of a disc but the latter is held at its periphery in a very rigid manner in a conical support having a angle corresponding to the angle of the working wheel so that the counter-discs forming the conical support follow the shapes of the part to be obtained. It is then necessary to use very high pressures so that the area being split is practically flat, but these machines are complicated and expensive because they require considerable power.

The present invention overcomes these drawbacks by creating a machine according to claim 1 or 2.

According to the invention according to claim 1, the slitting disc is rotated on a floating support, that is to say automatically compensating for unevenness while the slitting wheel (s) are mounted on a drive device rigidly supported on a fixed frame or vice versa, control means being suitably placed on the periphery of the slitting disc to automatically compensate for flatness irregularities by angularly and transversely displacing the rotary support as necessary floating disc or the drive device of the slitting wheel (s).

According to another variant of the invention according to claim 2, the mounting of the slitting disc is mounted on a floating rotary support and the slitting wheel (s) are also mounted on a drive device which can move as required on a frame designed for this function and then control means are arranged to automatically compensate for irregularities in flatness by angularly and transversely displacing, as necessary, the floating rotary support of the slitting disc and / or the drive device for the wheel (s) ( s) slitting.

According to a feature of the invention, the machine comprises a rigid frame on which are mounted two ends of shafts driven in rotation in synchronism, these two ends of the shaft carrying the disc or blank to be split deeply on its periphery then the aforementioned frame carries at least one U-shaped support articulated on an axis, this floating assembly being subjected to the action of a motor member making it possible to follow the deformations of the disc in order to allow at least one slitting wheel rotating on a shaft driven imperatively d '' nick and deeply cut the periphery of the disc.

According to another feature of the invention, the slitting wheel (s) have a thickness "E equal to seven or ten times the thickness" e of the slitting disc, the diameter "d" of the wheel (s) ( s) is between 30 to 70% of the outside diameter "D of the disc, the identical angle" A of each wheel is greater than 60 ° and can go up to 90 °, the peripheral end of each wheel is slightly obtuse and not cutting and, during the working phase for deep slitting, the working zone of the wheel (s) is permanently in an oil bath making it possible to avoid seizure of the wheel (s) and avoid also the removal of metal molecules from the disc.

• La figure 1 est une élévation schématique, partie en coupe, d'une première forme de réalisation de la machine dans laquelle la ou les molette(s) de refendage sont montées flottantes pour compenser les déformations et tensions internes du disque à refendre.
• La figure 2 est une élévation schématique, partie en coupe, montrant la machine dans laquelle le disque est monté sur un support rotatif flottant tandis que la ou les molette(s) de refendage sont montées sur un bâti fixe.
• La figure 3 est une élévation schématique d'une troisième forme de réalisation de la machine dans laquelle le disque à refendre est monté sur un dispositif d'entraînement rotatif flottant de même que la ou les molettes de refendage dont le support comporte un dispositif de suspension dit flottant.
• La figure 4 est une élévation latérale schématique correspondant à la fig. 3.
• La figure 5 montre une coupe-élévation d'un disque en cours de refendage profond et, en vue extérieure, l'une des molettes de refendage utilisée sur la machine.

Embodiments of the object of the invention are shown, by way of examples, in the accompanying drawings.

• Figure 1 is a schematic elevation, partly in section, of a first embodiment of the machine in which the slitting wheel (s) are mounted floating to compensate for the internal deformations and tensions of the disc to be slit.
• Figure 2 is a schematic elevation, partly in section, showing the machine in which the disc is mounted on a floating rotary support while the slitting wheel (s) are mounted on a fixed frame.
• Figure 3 is a schematic elevation of a third embodiment of the machine in which the slitting disc is mounted on a floating rotary drive device as well as the slitting wheel (s) whose support includes a suspension device said floating.
• Figure 4 is a schematic side elevation corresponding to FIG. 3.
• Figure 5 shows a sectional elevation of a disc during deep slitting and, in external view, one of the slitting wheels used on the machine.

In fig. 1, there is shown schematically the working area of a disc slitting machine, this machine generally being of the "lathe type". The two ends of the shafts 1, 2 are mounted on the ends of the lathe. Therefore, these shaft ends can rotate at a predetermined speed in the direction of the arrows F1, F2 (fig. 1). These shafts 1 and 2 thus rigidly hold the disc 3 the periphery 3a of which is to be slit deeply using at least one knurling wheel 4 which is mounted on a shaft 5 which is imperatively driven in rotation, this shaft 5 being mounted in bearings integral with a support 6 in “U fixed on axes 6a integral with the lathe bench so as to be able to move angularly according to the arrows F3, F4 (FIG. 4). Indeed, this support 6 in "U" is placed under the control of a double-acting cylinder 7 whose rod 8 carries at its end 8a a ball stop 9 integral with the lower part of the support 6 in "U". The supply to the double-acting cylinder 7 is effected by means of an electronic feeler 10 acting on the supply drawers of the double-acting cylinder 7.

The above description shows the use of a double-acting cylinder 7 of the hydraulic type, but in some cases it may be an electromagnetic device which could therefore be controlled directly by the electronic probe 10 opening and closing the circuits d power supply of the electromagnetic device replacing the jack 7.

As shown in fig. 1, the disc 3 is guided on its periphery by rollers 11 arranged in the horizontal plane parallel to the central axis of the ends of the shafts 1 and 2 and held in the slitting zone by rollers 12, 13 thus ensuring centering correct of the periphery 3a of the disc 3 relative to the slitting wheel 4. The rollers 12, 13 are mounted on shafts 12a, 13a secured to the support 6 in a U shape.

The above description therefore shows that the shaft ends 1 and 2 forming the support of the slitting disc are in a fixed position but due to the possibility of limited angular displacement of the support 6 in a "U" shape and of the correct maintenance of the periphery 3a. disc 3 by the rollers 11, 12, one can easily make up for the differences in flatness of the disc 3 and the irregularities coming from the release of internal tensions during the slitting work.

In fig. 2, the support 6 is shown in a "U" shape of the machine which is mounted on the bench and which carries a shaft 5 driven in rotation on which is mounted at least one slitting wheel 4. As in the previous case, the disc 3 is held on its periphery 3a by rollers 11, 12 mounted idly on axes 11a, 12a. On the other hand, the disc 3 which is pierced in its center by a channel 3b tightened by a flange 20 by means of a bolt 21 on a hub 22 is guided and driven in rotation by rods 23, 24 secured to a rotating shaft 25 in the direction of arrow F5 for example. The rod (s) 23 each having a head 23a allow the positioning of a helical spring 27 between the shaft 25 and the hub 22 while the rod (s) 24 simply allow the hub 22 to be guided relative to the shaft 25 due to the fact that the ends 24a of each rod 24 are placed between an overhanging crown 28 provided inside the recess 29 hollowed out in the hub 22. Thus it is possible to obtain very slight displacements to the right and to the left according to the arrows F6, F7 of the disc 3 to automatically catch up with the deformations of the disc or compensate for the release of the internal tensions of the metal. In addition, it is also possible to provide, as in FIG. 1, an electronic feeler (not shown) which then acts by means of a hydraulic cylinder or the like on the hub 22.

In this way, it is easy, with this machine, to perform a deep slitting of the periphery 3a of the disc 3.

In fig. 3, the mounting of the wheel 4 is identical to that of FIG. 1 and therefore bears the same references while the mounting of the disc 3 is identical to that described for FIG. 2 and therefore bears the same references. There is thus obtained a floating mounting of the wheel 4 and a floating mounting of the disc 3 thus ensuring automatic and perfect catching up of all the deformations of the flatness of the disc 3 as well as compensation for any release of internal tensions of this disc during the slitting from its periphery 3a.

The machine thus described therefore allows quick easy work of slitting the periphery of the disc to varying depths but which can for example be between 70 to 180 mm.

Although it has been described for the maintenance of the wheel 4 or of the disk 3 of the hydraulic and mechanical devices in order to ensure a floating assembly, one can use, instead of the hydraulic device, a pneumatic and even electric device by replacing the double-acting cylinder 7 and the guide device constituted by the hub 22 and the rods 23, 24 by electromagnets, small hydraulic or pneumatic cylinders to provide the same service.

Similarly, the servo rollers 11, 12, 13 can be mounted on shafts held by very sensitive means, for example of the electrical type, in order to control the exact position at each working instant of the disc 3 during the slitting operation. It should also be noted that the feelers 10 can be electric, hydraulic, pneumatic or other.

As indicated above, the machine described is adapted and designed to allow the deep splitting of the crown at the chosen location whatever the flatness of this crown and whatever the internal tensions which are released at the time deep slitting but this machine requires, in accordance with the invention, the use of at least one wheel 100 of great thickness "E which is substantially between eight and ten times the thickness" e "of the sheet to be slit and which is in fig. 5, the sheet metal constituting the wheel 102 whose central web 102a has been previously stamped to give it the desired desired shape.

The wheel 102 is mounted, as described above, on two ends of axes 103a, 103b driven by floating members represented here by the blocks 104. It should be noted that the outside diameter of the wheel 100 indicated by "d" is equal to at least one third of the outside diameter "D of disc 102. However, it should be considered that “d is most often between 35 to 40% of“ D •. In certain cases, the diameter of the wheel can be equal to 7/10 ° of the diameter "D of the disc 102.

In addition, and as shown in FIG. 5, the angle "A" of the wheel 100 is between 60 and 90 ° and has a peripheral terminal shape 100a which is not sharp but on the contrary slightly rounded.

Thus the disc 102 is forced to follow the wheel 100 because the latter is mounted, as has been said previously, on oscillating members 105 giving permanent centering thus making it possible to obtain the deep slitting of the crown of the disc 102 by creating wings 106, 107 of the same thickness which can, when the deep slitting is completed, be easily shaped to finally obtain the support of the tire.

During slitting, the slitting zone is maintained by mechanically driven rollers or rollers driven by electronic or electrical control in order to easily and immediately compensate for flatness defects and internal tensions.

During the slitting, the working area is permanently sprinkled with a special oil having qualities depending on the material to be slit in order to avoid the seizure of the thumbwheel 100 in relation to the disc or the uprooting of metallic molecules in zones of least resistance. Most often a fine cutting oil having a viscosity of 380 ° centipoise at a temperature of 20 ° C is used.

Although in the above description we mentioned the presence of a wheel 100, the work can be carried out by two or more wheels simultaneously, wheels having the characteristics described above and working under oil bath as explained in what precedes.

The knobs are made of a hard material which can be a special steel and in some cases even a special synthetic resin.

Claims (8)

1. Machine permitting the deep slitting in the periphery of non plane discs provided to obtaining pneumatic tyre wheels, characterized in that the disc (3) to be slit is driven in rotation on a floating support, i. e. a support automatically compensating for flatness irregularities, while the slitting roller(s) (4) are mounted on a driving device rigidly mounted on a fixed frame or vice versa, control means (12, 13 and 7 to 10) being suitably placed on the periphery of the disc (3) to be slit for automatically compensating for flatness irregularities by angularly and transversely moving according to needs the floatting rotating support (22) of the disc (3) to be slit or the driving device (6) of the slitting roller(s) (4).

2. Machine permitting the deep slitting in the periphery of non plane discs provided to obtaining pneumatic tyre wheels, characterized in that the jig for the disc (3) to be slit is mounted on a floating rotating support, and the slitting roller(s) (4) being also mounted on a driving device displaceable according to needs on a frame designed therefor, then control means (12, 12a, 13, 13a, 7 to 10) being placed for automatically compensating for flatness irregularities by angularly and transversely moving according to needs the floating rotating support (22) of the disc (3) to be slit and/or the driving device (6) of the slitting roller(s) (4).

3. Machine according to claim 1, characterized in that it comprises a rigid frame on which are mounted two stub-shafts (1, 2) rotatably driven in synchronism, these two stub-shafts carrying the disc or blank (3) to be deeply slit on its periphery, then the above mentioned frame carries at least a U-shaped support (6) articulated on an axis (6a), this floating unit being subjected to action of a driving member permitting to follow deformation of the disc (3) so as to permit at least one slitting roller (4) rotating on a driven shaft (5) to forcibly groove and deeply cut the periphery of the disc (4).

4. Machine according to one of claims 1 to 3, characterized in that the driving members permitting the angular displacement of the slitting roller(s) (4) are made by an electronic sensor acting, via an electrical connection, on the slides of a double action cylinder (7), thereby controlling, via a thrust-ball bearing (9), the angular displacement of the U-shapped support carrying the slitting roller(s) (4).

5. Machine according to one of claims 1 to 4, characterized in that the floating support of the disc (3) to be deeply slit is made by a rotating shaft (25) the end of which carries guiding rods (23, 24) permitting the angular displacement of a hub (22) made of two cylindrical parts connected by a bolt (21), this hub which carries in its center the disc (3) to be slit returning to its idle position after an angular displacement due to springs or resilient members (27) centered on one or various rods (23).

6. Machine according to one of claims 1 to 5, characterized in that both the support (22) of the disc (3) to be slit and the support (6) of the slitting roller(s) are floatingly mounted, and controlled by electrical, pneumatical or other sensors.

7. Machine according to the preceding claims, characterized in that the slitting roller(s) (100) have a thickness « E » comprised between about eight and ten times the thickness « e of the disc (102) to be slit, the diameter « d of the roller(s) (100) is comprised between 30 and 70 % of the outer diameter « D » of the disc (102), the identical angle « A of each roller (100) is greater than 60° and can be up to 90°, the peripheral end of each roller (100) is slightly blunt and not sharp and, during the working phase for the deep slitting, the working area of the roller(s) (100) is permanently in an oil bath permitting to avoid jamming of the roller(s) and to also avoid tearing off of metallic molecules on the disc.

8. Machine according to claim 7, characterized in that there is used an oil for fine cutting having a viscosity of substantially 380 centipoises at a temperature of 20 °C.

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