JP3078306B2 - Mechanical accelerator for can welding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical accelerator as used in a machine for welding cylindrical or similarly shaped hollow articles.

In the conventional welding machine in question, the discontinuous metal strip exiting the transfer is wound on a cylindrical shell to weld its two edges together. The feed direction of the strip is perpendicular to the transfer section, so that the mechanism must engage a strip that is already cylindrically wound around the guide rail, but still does not move in the longitudinal axial direction. The overlapping edges are finally brought together where they are welded together, the speed at which point is dictated by the operating speed of the welding member.

In short, the hollow cylindrical element must be accelerated along the longitudinal feed direction followed by the cylindrical element.

To this end, conventional welding machines utilize a pair of chain loop conveyors which now occupy a vertical plane, said conveyor passing through a cylindrical element and forming a plurality of pairs of engaging pins or teeth. A certain distance apart to provide, each pin or tooth engages the periphery of the rear end of each shell, pushing the shell to the next work location.

Such a chain is used to prevent the Canshel from being over-accelerated and to ultimately protect the Canshel from shocks that would cause permanent distortion of the surrounding edges, which would be a non-standard product in quality. Moves forward at a low speed of V ₀ −dV, and V ₀ + dV corresponds to the required production efficiency at the weld.
A motion of anharmonic at variable speeds V ₀ that accelerates the rate of.

Such an operation employs a cam-shaped linkage of particularly complex mechanical design, as shown in Italian Application No. 3400A / 89 filed by the same applicant. However,
The mechanism in question is that if the machine is not well adjusted, the impact on the surrounding edges that must occur during the pressing action of the teeth of the chain, without causing damage to the camshell, without the user of such a welder There is another limit that cannot reach even greater operating speeds as increasingly required by.

Accordingly, it is an object of the present invention to obviate the aforementioned disadvantages.

The object of the present invention is realized by using the accelerator according to the present invention, and the present invention has a cam drive mechanism that can even be inserted between the transfer unit, the shape unit, and the chain,
The chain drives the canshell forward for welding and reciprocates parallel to the path of the chain, such a device captures the stationary shell element in the correct form and does not damage the further required speed along the line without damage. Can accelerate.

The advantage of the mechanical device described in the present invention is that facilitating the shell never damages its surrounding edges, the conveyor in the lower line is driven at a constant speed, and complex and expensive linkages Is to be removed.

The device according to the invention, indicated generally at 1, is located between the transfer and forming unit 2 and the supply unit 4, wherein a discontinuous strip of metal 10 advances in the direction indicated by C, and has a cylindrical shape. And the shell element 3 thus formed by the supply unit 4 is conveyed in the direction of the part 5 and further to a line where the two overlapping edges of the element 3 are welded together.

The above-mentioned element is a typical conventional welding machine, the feeding unit 4 of which is provided with conveyor means designed to give the shell element 3 a movement along its own longitudinal axis in the direction indicated by F. 7; such a means has two chain loops 7 each of which form a vertical plane, and the shell element 3
A sufficient distance from each other and pass between them.

The two chains 7 each have a plurality of engagement teeth 9 spaced at regular intervals around the length of the loop, whereby one shell element 3 is engaged from the rear and carried forward. According to the invention, the chain of the supply unit 4 is driven at a constant speed V by a shaft 7a mechanically connected to the main drive mechanism of the welding machine. The accelerator 1 has a pressing means, shown as a flat block 11, which lies directly forward of the chain loop 7 with respect to the feed direction F and can move parallel to the feed direction F. From there, a pair of cantilevered cylindrical rods 12 extend forward in the direction of the chain loop 7. The rod 12 is located corresponding to the longitudinal socket provided by the block 11 and is fixed in that position by a clamping screw 13. The rod 12 is slidably supported in a support 14 which is rigidly mounted on the machine frame. This frame is shown schematically as a bushing in the example of the figure and guides the movement of the block 11.

Numeral 15 indicates the teeth incorporated into the protruding end of each rod 12 and arranged to form a pair of engaging teeth similar to the teeth 9 of the chain loop 7, but the teeth 15 of the rod 12 have another pressing force. It moves in a horizontal plane above the teeth 9 of the chain loop to act as a means. Block 11 is a groove provided by a turret extending upward from block 11
The upper arm 16 and the projection 17 provided for movement in the 18 F ₁ and F ₂
Reciprocating in the direction, the other end of the arm 16 is keyed to a freely rotatable vertical shaft 28 supported by the frame of the machine. 19 shows a second arm keyed at one end to the bottom of this similar vertical shaft 28 and acting as a swing axis, more precisely the second arm 19 is arranged on an axis parallel to the feed direction F And a roller 20 which slides in a groove of a cylindrical cam 21 driven by a motor M at a constant speed of rotation synchronized with the movement of the chain 7 and the other parts of the machine. Is stabilized by a spring 22 attached to the second arm 19.

The mechanical linkage described above is such that when the block 11 is in the retracted dead center, the teeth 15 of the rod 12 are at zero speed and are located behind the guide element 30 in front of the exit of the transfer section and the forming section 2. . Thereafter, the rotation of the cam 21 causes the block 11 to move forward (F1) so that its speed gradually increases from zero to a speed V substantially engaging the teeth 9 of the chain loop, causing the cylindrical element 3 to rotate. Tell At this moment the acceleration operation has ended and the cylindrical element 3 moves from the rod teeth 15 to the chain teeth 9 and then completes the transfer operation. Block from this point
11 decelerates to zero speed, returns to the previous position in the opposite direction (F2), and prepares for the next shell element 3.

The device described above properly calculates the rate of acceleration transmitted to the shell element 3, so that engagement and disengagement occur at each speed, while the chain 7 can be driven at a constant operating speed.

While the preceding description shows only one embodiment of the device of the present invention, block 11 is a mechanism using a sliding pair of roller tappets with cams formed to produce a similar intermediate and limiting device. Can be reciprocated.

[Brief description of the drawings]

FIG. 1 shows a schematic and perspective view of the essential structural features of a mechanical device. 3 shell elements, 4 supply units, 7 conveyor means, 12 pressing means.

Claims (5)

(57) [Claims] 1. a main support frame; a weld; a transfer section from which a discontinuous strip of can material formed in a cylindrical shell element for applying a weld is provided; and along conveyor means. Conveyer means extending, rotating in a defined feed direction, engaging at least one trailing edge of the shell element, and forming at least one chain loop having a plurality of teeth fed one by one in the direction of the weld. A supply unit interconnecting the transfer section and the weld on the one hand and being independently moved towards the weld on the other hand; provided immediately before the conveyor means with respect to the weld and operating at least in synchronism with the conveyor means A mechanical link mechanism that engages with a cylindrical shell element emerging from the transfer and forming sections to achieve a substantially zero relative velocity. Three retracted positions: an intermediate position where acceleration reaches a speed that substantially matches the speed of the teeth of the chain and ends; and a fully advanced limit position where the motion is reversed to zero speed. A mechanical acceleration device of a can welding machine comprising a pressing means capable of performing a reciprocating motion in parallel with a supply direction between the two. 2. The mechanical acceleration device for a can welding machine according to claim 1, wherein the speed of the pressing means in the fully retracted position is zero. 3. A mechanical link mechanism comprising: a continuously driven cylindrical cam; one end engaged with the cam and the other end keyed to a vertical shaft rotatably supported by a main support frame. The mechanical accelerating device of a can welding machine according to claim 1, comprising: a swing arm; and a swinging horizontal arm keyed to the top of the vertical axis and connected to a pressing means. 4. A pair of cantilevered cylinders, the pressing means being movable parallel to the feeding direction, projecting forward in the direction of the chain conveyor means, and being slidably supported by guides rigidly incorporated in the main frame. A flat block for supporting the rods of the chain; incorporated into the projecting end of each rod, forming a pair of pressing elements, and acting on the chain teeth so as to act as a separate means from that provided by the chain teeth. The mechanical acceleration device for a can welding machine according to claim 1, comprising a pair of engaging teeth occupying and moving in an upper horizontal plane. 5. A mechanical acceleration device for a can welding machine according to claim 3, further comprising spring means incorporated in the swing arm to ensure stable engagement with the cam.