US2593730A - Apparatus for making pierced forged hubs and the like - Google Patents

Description

April 22, 1952 D. R; CORNELL 2,593,730

APPARATUS FOR MAKING PIERCED FORGED HUBS AND THE LIKE Filed May 6, 1946 4 Sheets-Sheet l l N V EN T OR. DANA P. Cos/v54 z.

A ril 22, 1952 D. R. CORNELL 2,593,730

APPARATUS FOR MAKING PIERCED FORGED HUBS AND THE LIKE Filed May 6, 1946 4 Sheets-Sheet 2 INVEN TOR. Dfl/V/P P. CoewzLL w 2 BY mzww u w ,4 7- TOP/YE Y April 22, 1952 D. R. CORNELL 2,593,730

APPARATUS FOR MAKING PIERCED FORGED HUBS AND THE LIKE Filed May 6, 1946 4 Sheets-Sheet 3 I N V EN TOR. DANA 2 COPNEL L /4 T Ta /YE Y A ril 22, 1952 D. R. CORNELL 2,593,730

APPARATUS FOR MAKING PIERCED FORGED HUBS AND THE LIKE Filed May s, 1946 4 Sheets-Sheet 4 F/a. 4 J .1...)

2a VII/III INVENTOR. Ha 6 DANA P. CORNELL.

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A TTOE/YE r Patented Apr. 22, 1952 APPARATUS FOR MAKING PIERCED FORGED HUBS AND THE LIKE Dana R. Cornell, East Chicago, Ind, assignor to Standard Forging Corporation, Chicago, 111., a

corporation of Delaware Application May 6, 1946, Serial No. 667,678

2 Claims.

This invention relates to apparatus for making pierced forged wheel hubs from preformed forgings having boreless hub bodies.

The apparatus herein shown and described embodies certain additions to and improvements in the apparatus disclosed in United States Letters Patent No. 2,342,021, dated February 15, 1944., whereby the savings in metal and operating costs described in said patent are substantially increased without weakening the resultant hub structures.

Prior to the application for the said Patent No. 2,342,021, hubs had been produced by forging steel to the desired dimensions and form of the hub and then drilling through the hub axially and removing the metal occupying the bore. The bject of this invention is to produce a hub having the desired dimensions, form and bore by forging and piercing operations, without drilling and without removing all of the metal initially occupying the bore. Valuable advantages result from this invention, such as the saving accomplished by using in the hub most of the metal which in the past has been removed in the drilling of the hub to produce the bore. Thus the operator is enabled to use a blank of less initial weight for a given sized hub, and consequently less heating and handling is required.

Prior to the invention disclosed in said Patent No. 2,342,021, it was necessary to use metal having a gross weight of 240 pounds in order to obtain a not solid forging weight of 225 pounds, and to discard approximately 25 pounds thereof in the drilling operation, resulting in a bored hub of 200 pounds net weight. By using the apparatus of said patent, it was possible to produce a pierced forged hub similar in dimensions, form and efliciency to said drilled forged hub, yet reduced in weight to 192 pounds. The forging operation was begun with 212 pounds of metal, the net preformed forging weight was 197 or 198 pounds, and. the pierced forging weight 192 pounds, only 5 or 6 pounds being discarded in the piercing operation.

By using the apparatus of the present invention, still greater reduction in weight of metal, both in the solid and pierced forgings, is attained. I am able to produce a pierced forged hub'substantially similar in dimensions and form and equal in efiiciency to the heavier ones heretofore described, by starting with a gross weight of 183 pounds, resulting in a net solid preformedforging weight of 166 pounds and a pierced forging weight of 160. pounds. Only about. six pounds of the initial stock of the solid preformed forging is dis- 2 carded. Thus the heating and handling of approximately 24 pounds, the difference between 212 and 188 pounds, are saved by using the improved apparatus disclosed herein instead of the apparatus of said patent- These additional advantages and increased efiiciency in operation are attained by certain changes in the piercing tool and by the addition of mechanism for supporting the forging duringv the piercing operation whereby the preformed solid forging is pierced and formed, its axial di. mension being materially increased, without separation or weakening of the metal in the pierced thin walls. The said forging supporting means also serves to hold the forged hub con centric with the die cavity.

Due to the additional reduction in Weight, the preformed forged solid shape which I employ is substantially shorter than the solid forging em-,- ployed in the invention of the patent aforementioned, and greater care is required in axially lengthening it without weakening the resultant structure. The combined piercing and extrud ing treatment forms the axial bore and radially displaces and spreads and axially lengthens the metal into the desired hub form and dimensions with removal of a very small amount of metal. Prior to the piercing operation, the preformed forging has at least a i draft but after the forged metal has been subjected to the displacing, spreading and lengthening resulting from the operation of my apparatus, the external inclination isonly about 2", and thus the excess thickness is reduced to a minimum and all but a very small percentage of the initially heated metal has been embodied in the finished hub.

In the drawings:

Fig. 1 is a front elevation, partly in section, of apparatus for making pierced forged hubs em bodying my invention, showing the piercing tool" in its downward stroke, having passed partly through the solid forging.

Fig. 2 is a view similar to Fig. 1, with parts of the mechanism broken away, showing the piercing tool at the end of its downward stroke after having pierced and extruded the solid forging.

Fig. 3 is a view similar to Fig. 2, showing the piercing tool raised and withdrawn from the pierced forging.

Fig. 4 is a sectional view of the preformed solid forging from which the pierced hub is produced, the dotted lines indicating the shape of the finished hub. v

Fig. 5 is a sectional view of the pierced forged" hub.

In that embodiment of the invention shown in Figs. 1, 2 and 3, inclusive, frame members ID, ID support a ram H in which is mounted the frame I2 which has a key 13 slidable in the keyway of the ram. A head I4 is mounted in the slide frame 12, being insertable in the frame by a horizontal sliding action and retained by wedge members if: adjusted by screws It. A pair of guide rods I! depend from the frame 12 and are movable therewith.

A punch or piercing tool 18 is mounted in the head 14. The tool 18 is concentric and frustoconical in form, being of greater diameter at its upper end 19 than its lower end where it terminates in the inwardly tapered surfaces 29, 2 i, said surface 20 being located slightly inwardly of the frusto-conical wall 18 so as to form a right angle edge 22 at the bottom of the body of the tool. The taper of the body 18 is made to conform to the finished machined size and tapered shape of the boreof the hub intended to be produced.

Concentric with the tool 18 is the lower die comprising the parts 23, 24 25 and 2d fitted and bolted together and having a recess or cavity adapted to receive the forging 2'1 shown in Figs. 1 and 4, with the flange 25 of the forging supported by the die members 25, 23, and the lower end of the forging 21 spaced from the apertured end or bottom 29 of the recess as shown in Fig. l. The hub portion of the forging is spaced, radially, a slight distance from the recessed die 23, there being "about a 2 difference in the inclination-of the forging wall and the side walls of the recess in which the forging is located, as indicated at 35 in Fig. 1.

After the forging has been positioned .in the lower die, a cover 31 is placed on the forging and rests on the flange 23. The cover is centrally apertured to accommodate the upper end of the hub. The lower die members are apertured (not shown) to receive the guide rods ll. The cover 3| is held on the die and the work by two sets of jaws 33 shown in clamping position in Figs. 1 and 2, and retracted in Fig. 3. The jaws 33 are rigidly connected to connecting rods 3d actuated by pressure fluid in the cylinders 35. When the jaws are in clamping position, they hold the die, work and cover securely together. The jaws and cylinders are supported by struts 35'. The dies 23, 24 rest on a suitable base such as the member 36, which is provided with an aperture 3? which is concentric with the tool 18.

Located below the base 35 is a plunger 38 provided with an upper pointed, tapered end 39 and with a piston 40 on its lower end. The piston 40 and plunger 38 are mounted in an hydraulic or other fluid cylinder 41 which has an upper port 42 and a lower port 43 communicating with fluid chambers above and below, respectively, the piston 4B. Said ports are connected by conduits through a four way valve 44 (shown diagrammatically) to a fluid (preferably oil) supply tank 41. A solenoid 45 controls the valve 44 and is electrically connected to a foot operated switch 48 and to a switch 43 on the frame Ill, said switch 49 being designed for actuation by the finger 50 on the ram l I. 45 indicates a back pressure valve in the conduit between the port 43 and supply tank 41. Below the base 36 is a chute i designed to receive the waste slug 52.

The recess in the upper portion of the solid preformed forging"?! is indicated at 53, and the recess in the opposite end at 54. lhe bore in the finished pierced forging is indicated at 55.

The operation of the apparatus is as follows: The forging 21, preformed and solid as shown in full lines in Fig. 4, is placed on the die members 23, 24, 25, 26 as shownin Fig. 1, the cover 31 is placed on the forging, the jaws 33 are moved into clamping position, and the slide frame I2 carrying the head I4 and tool 18 is moved to bring the tool into a position concentric with the forging.

Then the operator steps on the electric foot switch 48 which is. connected to the solenoid 45 in such manner that it actuates the four way valve 44 to direct oil to the bottom of the cylinder 4!, through port 43, to raise the plunger 38 into the position shown in Fig. 1, where the upper end 39 of the plunger engages the depression or recess 54in the forging 21. The plunger 38 remains in that position temporarily under influence of the oil pressure beneath the piston 48 in the cylinder 4|.

Next, the ram H is made to descend, being operated by any suitable means (not shown) and carries with it the tapered tool l8 which pierces the forging 21. The downward travel of the tool i8 displaces some of the metal of the preformed forging 2'! radially and axially, thereby spreading the metal and lengthening the forging axially to a substantial extent. This extruding of the metal takes place while the forging is being supported by the plunger 38 which, during this part of the operation, is held raised by oil pressure. This action of the tool i3 and consequent lengthening of the forging in a downward direction causes the forging to bear down on the plunger 38 and to force the plunger down against the fluid pressure in the cylinder 41. Some oil is thereby forced out of said cylinder, through the heel; pressure valve 45 to the supply tank 4'5, but pressure is maintained against the piston 4? throughout the downward stroke until the waste metal slug 52 has been formed and forced out of the forging and through the bottom 29 of the die recess. At this point in the press stroke, the finger 50 on the ram ll comes into contact with the electrical switch 49 on frame it (Fig. 2). Said switch 49, through its connection with the solenoid 46, functions to actuate the four way valve 44 in such manner that it reverses the oil flow and pressure to the top of the piston 43. This causes the plunger 38 to move quickly down, out of the way, and allows the waste slug 5-2 to fall into the chute 5|.

By comparing Figs, 1 and 2, it will be seen that the forging 21 of Fig. 1 has been reshaped and the metal displaced both radially and axially into the pierced hub 21 of Fig. 2 by the action of the descending tool l8 while the forging 27 was supported by the pressure-controlled plunger 38.

Fig. 2 also shows the contacting of the finger 55 with switch 49 which takes place when the tool 13 has reached the end of its down stroke. Said actuation of the switch 49, as heretofore explained, causes the solenoid 45 to operate the four way valve and thereby to make oil flow into the top of the cylinder and move the piston 46 down quickly. Fig. 2 shows the piston and the plunger 38 after having started downwardly under influence of the oil pressure above the piston.

Fig. 3 shows the plunger 38 at the end of its down stroke, and the tool [8 in raised position. Now the pierced hub 21' may be removed from the apparatus. After another unbored forging 21 has been positioned on the dies, the cycle of operations may be repeated by starting the switch 48, to actuate solenoid 45, to operate four way valve 44 andforce oil into the bottom of cylinder 4| to raise plunger 38, as heretofore explained.

An important feature of the invention is the controlled support supplied to the forging 21 while it is being reshaped and bored. The provision of said controlled support in the form of the fluidpressure controlled plunger 38 prevents separation of the metal in the relativelythih walls of the bored hub portion below the flange 28. The cooperation between the tool I 8 and the plunger 38 results in maintaining the density and continuity of the metal throughout the piercing and extruding operation.

Changes may be made in details of construction and the form of some ofsthe parts of my apparatus without departing from the scope of the invention as set forth in the'appended claims.

I claim:

1. In metal working apparatusincluding a centrally recessed work forming dieihaving a slug ejecting aperture in its base in alignment with said recess and an annular shearing step at the juncture of said recess and aperture, a reciprocating ram and a piercing tool-actuated by the ram, said piercing tool havingia leading shearing end adapted to cooperatewith said shearing step to sever the slug remaining .from the piercing operation, cushioning means opposed to the piercing tool and initially extending through said aperture and into said die recess for yieldingly engaging the work and retarding axial movement of the metal thereof by the piercing tool whereby said metal is forced in radial directions to fill the die recess while the piercing tool is moving axially through the work and into said aperture, said cushioning means comprising a reciprocating plunger, a piston on the plunger, and means for controlling the plunger, said controlling means comprising a cylinder concentric with the plunger and in which the piston is operably disposed, a fluid supply under pressure, conduits connecting the supply to the cylinder above and below the piston therein, a back pressure valve in the conduitv between the supply and the bottom of the cylinder for providing cushioned movement of the plunger with the work during penetration thereof by the piercing tool and upon completion of the piercing operation adapted to cooperate with the piercing tool to grip'the slug as it is sheared from the work, a four way valve in the conduit, manually operable means for actuating thel ivalve' to direct fluid to the bottom of the cylinder and raise the p-lunger'to initially move the-plunger through said aperture and into said recess? in bearin engagement with the work, and aivaljve actuating solenoid operable by the ram when the ram and piercing tool have reached the end of their downstroke With" the end of the piercing tool in said aperture for actuating said four way valve to direct fluid to the top of the cylinder and quickly move theplu'nger out of the aperture so that the slugmay beejected.

2. The structure acccrding'to'claim 1, wherein said piercing tool and plunger have opposed axially aligned conical endsfor augmenting the piercing and shearing operations.-

DA NA' R. CORNELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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