The invention relates to improvements in progressive forming machines and, in particular, to tooling accessories for such machines.
Progressive formers shown, for example in U.S. Pat. Nos. 5,829,302 and 5,848,547 are well suited for making complex parts at high speeds and with little or no scrap. In such machines, a blank is typically cold formed at successive workstations by striking the blank with different tools that reciprocate in the same direction on a common slide or ram.
A need exists in the forming of certain products for a tool that moves in a path that is transverse to the motion of the ram. An example of such a product is a tubular part with a radial hole or holes through its sidewall.
The invention provides a tooling arrangement for a progressive cold former capable of forming a workpiece or blank with a forming blow or force transverse to the reciprocating direction of the ram of the machine. The disclosed arrangement utilizes sliding cam surfaces that convert ram motion to transverse or lateral motion for a tool element. The cam surfaces are outside of the swept or axially projected area of tool and die cases and are thereby enabled to be more robust than would ordinarily be practical. In a specifically disclosed arrangement, co-acting cam surfaces are both disposed on a stationary die side or bolster side of the machine and are actuated by tooling mounted on the ram.
The disclosed side motion tooling is arranged to pierce opposite sides of a hollow cylindrical wall of a blank to form circular holes in the wall by shearing out circular slugs. Prior to the actual piercing action, the blank is laterally gripped to lock it in place relative to the piercing pins and associated tooling elements. This gripping action reduces stresses on the pins which can otherwise cause premature failure of the pins.
The disclosed side forming mechanism is particularly suited for use on forming machines that use cassette tooling. Such machine arrangements can permit the mechanism to be carried on the tooling cassettes and thereby avoid major modification of existing machine structure.
In the present arrangement, the invention is utilized at the last workstation 11E, shown in the foreground in
The tooling includes a die block 22 removably fixed to the die breast plate 13, a generally cylindrical die case 23 received in the die block, a tool holder 24 removably fixed to the ram housing 16, and a generally cylindrical tool case 25 received in the tool holder.
The blank or workpiece 21 which, in the illustrated case as it is transferred to the last workstation 11E, is a hollow cylindrical article with an internal wall 26. The blank 21 is held immediately in front of the die case 23 by fingers of the transfer mechanism in a manner known in the art.
The die case 23, shown in a forwardmost position in
The section view of
In the illustrated embodiment, the side action mechanism 28 is arranged to pierce the workpiece or blank 21 on diametrically opposed sides. Pierce pins or tools 36, most clearly shown in
As the ram 17 advances the tool case 25 towards the die breast plate 13, a blank delivery sleeve at the center of and leading the tool case pushes the blank 21 into the die case 23 between the blank grip wedges 33. Thereafter, a projecting central area of the tool case 25 pushes the grip wedges 33 into a tapered slot in the die case 23. The tapered slot causes the wedges 33 to tightly radially clamp onto the blank 21 and prevent the blank from movement under piercing loads.
Advance of the ram 17 causes the tool case 25 to contact and then drive the die case 23 into the die block 22. A study of
A pusher 53 rigidly bolted to the tool case 25 engages the lower part of the primary driver 41 and secondary driver 42 to assure that these elements remain aligned with the die case groove 44 during their sideways stroke.
The pierce pins 36, guided by associated holes in the grip wedges 33 shear slugs of circular or other shape from the wall of the blank 21. Relative axial movement between the grip wedges 33 and the drivers 41, 42 is accommodated by T-slots 39 in the drivers in which the retraction sleeve flanges 38 are assembled. A mandrel 57 projecting from the blank delivery sleeve 46 supports the interior of the blank 21 during the piercing step. Screws 58 in the tool case 25 provide axial adjustment of the mandrel 57 so that holes in the mandrel are in line with the pierce pins 36. The slugs formed by the pierce pins 36 are swept out of the mandrel 57 by a vacuum applied to a tube 56.
When the tool case 25 and pusher 53 retract with the ram 17, the gas springs push the die case 23 out of the die block 22 to the position illustrated in
The disclosed side action mechanism 28 is very strong for its size. As disclosed, the mechanism 28 is carried on the tooling so that it avoids modification of the basic parts of the machine 10. Consequently, the mechanism can be employed at substantially any workstation and can be used in machines that have been previously manufactured and are in field service.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.
Number | Name | Date | Kind |
---|---|---|---|
5829302 | Hite | Nov 1998 | A |
5848547 | Hite | Dec 1998 | A |
8485013 | Hossler | Jul 2013 | B2 |
Number | Date | Country |
---|---|---|
100 30 792 | Jan 2002 | DE |
10 2012 100340 | Jul 2013 | DE |
2011 025267 | Feb 2011 | JP |
Number | Date | Country | |
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20180214931 A1 | Aug 2018 | US |