US2064160A

US2064160A - Apparatus for die drawing large irregularly shaped sheet metal articles

Info

Publication number: US2064160A
Application number: US582032A
Authority: US
Inventors: Hochreiter Edward; Frank E Mcgary
Original assignee: Edward G Budd Manufacturing Co
Current assignee: ThyssenKrupp Budd Co
Priority date: 1931-12-19
Filing date: 1931-12-19
Publication date: 1936-12-15
Anticipated expiration: 1953-12-15

Description

De@ 15, 1936. E. HocHRElT-ERA'ETAL 2,034,160 APPARATUS ECR DIE DRAWING' LARGE IRREGULARLY SHAPED SHEET METAL ARTICLES Filed Dec. :19,l 1951 5 sheets-sheet 1 INVENTOR.

EDWARD HQCHREUER l FRANKBNQ GARY- De 15 1935- E. HocHRElTER Er AL 2,064,160

APPARATUS FOR DIE DRAWING LARGE IRREGULARLY S'IAPED SHEET METAL. ARTICLES vFiled Dec. 19, 1931 5 Sheets-Sheet 2 23 n Fm INVENTOR. EDWARD HOQHREITEQ. -PRMKBMC'CTARY ATToRNEY.

15, E936. E. Hoge-:REITER ET A1. 2,054,160

APPARATUS FOR DIE DRAWING LARGE IRREGULARLY SHAPED SHEET METAL ARTICLS Filed Dec, 19, 1931 5 Sheets-Sheet 3 l, Il" "I A FRANKEMC-GARY Y BY - M'ZTVEY.

De@ i5 3936 E. HOCHREITER ET AL.' 064,169

APPARATUS FOR DIE DRAWING LARGE IRREGULARL-Y SHAPEDV SHEET METAL ARTICLES Filed Dec. 19, 1931 s sheds-sheet 4 K 34 y l? 3 36 Fl. l5

1 I l r -IQ 33 :1 -1a?.- 30

l' ll il c l' mo FRANK CGARYl lll BY E M jww 0 ATTORNEY.

Dec. 15, 1936.

. E. HocHRElTER ETAL 2,064,160 APPARATUS FOR DIE DRAWING LARGE IRREGULARLX SHAPED SHEET METAL ARTICLES Filed Dec. 19, 1931 5 Sheets-Sheet 5 i8 Y Z Y AFlag/14 M ATTORNEY.

Patented Dec. 15, 1936` )PATENT oFFIcE ArrAnA'rUs ron nm mmwnve.r maar:

IRREGULARLY- SHAPED SHEET METAL ARTICLES Edward Hochreiter and Frank E. McGary, Philadelphia, Pa., assignors to"v Edward G. Budd Manufacturing Co., Philadelphia, Pa., a corporation of Pennsylvania Application December 19,1931', Serial No. 582,032

7 Claims. (Cl. 113-46) The invention relates to an apparatus for forming large sheet metal stampings of irregular form.

It is a main object of the invention to reduce 5 the cost of forming such stampings to improve -their surface and generally to provide an article of this class which is superior to the articles heretofore produced. In the present application the invention is shown applied to the formation -of anentire front fenderfincluding the inclined apron joining the crown of the fender to the body or chassis and the horizontal ledge bridging the space between this inclined portion and the body. The crown of the fender is of a double 'horizontal ledge. In the region where the curved crown intersects the horizontal ledge, less metal is required to form the fender than in it-s forward and rearward portion, and in previous at tempts to draw the entire fender, ridges and wrinkles have resulted in this region which were impossible of complete removal, even with expensive operations of hammering and grinding, and-thus marred the entire stamping. Sucha o condition has manifested itself in other relations,

where the drawwas directed in diiferent directions in different parts of a. large irregular stamping in regions between such parts, or where the conditions of draw left too much metal in certain regions to be removed without wrinkles by the draw in other regions.

The present invention has remediedthis condition., and by the use of it a large irregularly formed'stamping of this class can be produced with a smooth lsurface throughout and with a minimum number of operations. The main feature of the invention by which these improved results are attained is the use of the step of stretching the metal of the blank in a direction which I 40 will tend to remove the excess metal from the region likely to produce wrinkles prior to the final forming operation.

The invention also resides in the means whereby this step can be carried out in proper sequence to the nal forming and with a single die press operation.

Other and further objects and advantages will become apparent from the following detailed description of a form of apparatus well adapted to carry out the method and as used in the formation of complete fenders.

In the accompanying drawings showing the invention applied to the. formation of the diilicult complete fender stampings,

Fig. 1 is a perspective view of a fender stampcurvature, its rear portion dipping below the ing made in accordance with the invention, with the excess metal necessary for the drawing trimmed off. l

Fig. 2 is a central vertical longitudinal sectional view of the fender shown in Fig. l.

Figs. v3 and 4 are transverse sectional views taken respectively on the correspondingly numbered lines of Fig. 2.

401. is a transverse section of the fender stamping corresponding to the section shown in Fig. 4 showing the stamping before trimming rand indicating in dotted lines the trim lines.

Fig. 5 is a plan view of an, untrimmed fender stamping indicating the region in which the wrinkles have heretofore formed, and showing in dottedlines the location of the auxiliary die for removing the excess metal in this region laterally in the drawing operation of the complete stamp-s ing.

Fig. 6 is a fragmentary elevational view of a double-action press to which the invention is shown applied, the dies being shown in separated position.

Fig. 7 is a longitudinal vertical sectional view showing the dies and work in theposition they occupy at the end of the draw.

Fig. 8 is a corresponding View of the parts at lthe beginning of the draw.

Fig. 9 is an endperspective view, parts being broken away and shown in section, showing the same just prior to the final draw.

Figs. 10, 11, 12, 13 and 14 are corresponding vertical transverse sectional views showing successive different positions of the parts, respectively, in the approach movement of the dies.

Fig. 15'is a fragmentary sectional view, looking at the inside face of the well or depression in the .lower die showing the parts in the position indicated in Figs. 7 and 14.

In the drawings', the apparatus for carrying out the improved method comprises a double acting press in which A designates generally the lower holding die block, B the upper movable holding die block, C the plunger or ram, D an auxiliary upwardly moving die mounted in the lower holding die block A and E, a floating stretching die mounted in the upper holding die.

The lower holding die block A is supported in a usual manner upon the bed I0 of a press and has a central well or recess within which lthe movable ram C and die D may be accommodated. Surrounding this well it is provided with a continuous seat Il adapted to receive the peripheral portion of the blank I2,the seat being generally inclined inwardly toward the well, as clearly appears in Figs. 7 to 13. Centrally of the well'is a transverse wall I3 on one side of which is mounted the vertically movable auxiliary die D.

The face I I of the lower holdingV die is provided with recesses |5 and projecting ribs I6 extending longitudinally-of the seat, and adapted to cooperate with corresponding recesses on the upper holding die to firmly grip the blank. The depth of lthese ribs and' recesses may vary in various locations in accordance with the firmness which it is necessary for the blank to be held in those locations.

The upper holding die B is supported in a usual manner from the vertically reciprocating head I'I of the press and is provided with a working face I8 corresponding to the face II of the lower holding die, and between these faces the peripheral portion of the blank is gripped in the nal approach movement of the holding die B, as indicated in Figs. 10 to 13. A

The holding die faces conform to the peripheral portion of the blank and are adapted to receive a substantially flat blank located as by pins (not shown) on the lower die, and slots on the edges of the blank adapted to engage the pins.

'Ihe plunger C is designed to eiect the major draw upon the blank and is mounted on a vertically reciprocating head I8 movable independently ofthe head I'I carrying the upper holding die. In longitudinal section lower working face I9 of the plunger C is of a double curvature, con- 'forming to the shape of the work to be formed,

and the face is also transversely curved as indicated in Figs. 9 to. 13. l

The lowest point of the plunger face I9 is also the region of the greatest draw, and the plunger is free to reciprocate vertically through a central opening in the upper holding die block B and into the well of the lower holding die block A.

In conformity with the shape of the article, a portion of the draw is made in the reverse direction from the movement of the plunger C in making the main draw, and the means for making this reverse draw is the die D having an upper face 20 corresponding to the shape of the' article in the region remote from the end engaged by th lowest portion of the plunger.

The actuating means for this die, as clearly shown in Figs. '7 and 8, is a horizontally sliding cam block 2| mounted in the base of the die block A and having on its upper face stepped cam faces 22 adapted to coact with corresponding cam faces 23 on the lower side of the die D. It is guided in its longitudinal movement by gibs 24, and is actuated in the vertical movement of the plunger C by a vertical actuator block 25 secured to the head I8 carrying the ram or plunger C, and having an inclined cam face 26 acting on an inclined block 25 engage the correspondingly inclined under side of the inwardly extending edge plungers 2| of the brackets 22 secured to the block 2|.

Between the .front and-rear portions of maxi-v mum draw, there is a region of minimum draw Aand in this region, as indicated at 21 in Fig. 5, the

metal of the blank has, heretofore, been pushed up into wrinkles. To avoid this objectionable condition, the apparatus of the invention is provided With means for transversely stretching the metal as indicated by the arrow b in said figure and to this end, opposite said region of minimum draw the lower holding die face II is formed with a longitudinally extending recess 28 laterally located between the blank gripping ribs and depressions on the lower and upper holding die faces I and I8, respectively, and the central well into which the ram C descends. The edges of this recess are rounded and the oating die E mounted for vertical movement in the upper dieblock is adapted to have its lower longitudinally and transversely rounded face 29 descend into this recess after the blank has been iirmly gripped by the opposed holding die faces II and I 8, and transversely stretch the blank to remove the excess metal in this longitudinal region of the blank prior to the nal die drawing operation, and thus avoid the wrinkling of the metal in this region.

The die E is guided in a vertical slot 30 in the upper holding die block B and has at its upper end an inclined cam face 3l which is adapted to be engaged by a corresponding cam face 32 on an actuator block 33 guided for transverse movement in the block B, and itself adapted to be actuated by a vertically movable actuator block 34 secured to the vertically reciprocating ram carrying head I8. This actuation is by the'engagement of a cam face 35 on the lower end of the actuator 34 with a correspondingly inclined cam face 36 on the actuator block 33. After the block 33 has been moved` transversely by the engagement of said cam faces, a vertical face 3'I on the actuator 34 slides in engagement with a corresponding face 38 on the actuator block'33 and maintains it in operative position during the further descent of the head I8'. Suitable springs 3 3' act upon the block 33 to move it to inoperative position after it is released by the upward movement of the actuator 34.

From the foregoing description of the construction of the improved apparatus its operation will be readily understood from the following description of its operation when read in connection with the various iigures of the drawings showing different successive stages of the operation.

A flat metal sheet roughly of the peripheral contour shown in the plan view of Fig. 5 is ilrst placed over the lower holding die A with-its peripheral portion resting on the face II of the lower holding die while the parts of the press are in the position shown in Figs. 6 and 10.

'I'he press is then operated to cause the upper holding die B to descend and grip the margin of the blank between the mating faces II and I8,

respectively, of the lower and upper holding dies, as shown in Fig. 11.

After the' sheet is grasped by the holding dies,

the lowest portion of the ram C strikes the sheet and starts the drawing operation in thev region of the deepest drawat the front of the fender blank `n1ediate the front and rear deeply drawn portions of. the blank, all as clearly shown in the figures of the drawings above referred to.

The metal of the blank will thus be simultaneously subjected to drawing strains in the three directions indicated by the arrows a, b and c of Fig. 5.

In the final drawing movement of the dies C and D, a longitudinally extending raised projection 40 at the side of the ram in the longitudinal region of the minimum draw opposite the stretching dieE engages the blank and depresses it into a corresponding recess 4| in the lower holding die face and thus further transversely stretches the blank in this region and at the sam-e time the entire blank is given the final drawing, which is completed when the parts reach the position shown in Fig. 7, when the blank is nally formed.

By so transversely stretching themetal of. the blank transversely through die E and projection 40 in the intermediate region of minimum draw,

while subjecting the opposite ends thereof to rela' er stamping shown in Figs. 1 and 2 produced from a fiat blank at one operation of the press.

After the stamping has been formed the movable dies recede to the positions-shown in Figs.

6 and 10, and the stamping is removed from the press and subsequently trimmed along the dotted lines indicated in Figs. 4a and 5 to produce the finished complete fender shown in Figs. 1 and 2.

The operation of. forming the stampings can proceed as rapidly as the press operation permits, a complete fender being formed at each operation.

While the invention has been shown and de- -scribed in connection with the manufacture of complete fenders, it will be understood that the outstanding feature thereof, namely, the stretching of the metal of the blank to remove excess metal from a region of minimum draw may be practiced in connection with the formation of irregularly shaped stampngs of .other forms and the particular structure of the apparatus by which this is achieved may be varied to suit the conditions of the particular forrl. of stamping being made, without departing from the generic spirit of the invention as expressed in the claims appended hereto.

What we claim is: l

1. Apparatus for die stamping large irregularly shaped sheet metal articles comprising means for' rigidly clampmg .the side and end edges of. an elongated blank, means independent of said clamping means for substantially stretching the blank transversely of its length in the plane of the blank when so clampedr and Ameans for die drawing the blank, when so stretched and rigidly held, movable generally transversely to the plane of the blank.

2. Apparatus for die drawing sheet metal articles of irregular form which consists of a bed having surfaces upon which the peripheral margins of the blank are adapted to rest, means covacting with said surfaces to clamp the margins in place, a die movable generally transversely to the sheet for drawing and shaping it, and a stretching die independent of the clamping meansto the iinal drawing of the blank to the required form.

3. Apparatus for die drawing sheet metal fenders comprising clamping means for holding the side and end peripheral portions of an elongated.

blank, a punch movable within said clamping means generally transversely to `the plane of the blank to form the same, and a die actuated independently of the clampingmeans `in the movement of said punch for -engaging a peripheral portion of the blank and thereby substantially stretching the metal of the blank transversely in a' region of minimum draw prior to the final drawing movement of the punch.

4. Apparatus for die drawing sheet metal fenders comprising albed having a-peripheral surface adapted to receive the margins of the blank, and a well within said surface, a die mounted in said bed for upward movement, a punch adapted for downward movement into said well, means associated with said punch for moving the said die upwardly while the punch moves downwardly to draw the metal of the blank in opposite directions at opposite ends thereof.

5. Apparatus for die drawing sheet metal fenders comprising a lower die having a peripheral surface for receivingthe marginal portion of the blank, and a central hollow well, a vertically movable die adjacent one end of the well and a vertically. movable ram, a. clamping die surrounding the ram and movable to clamp the marginal portion of the blank between it and the peripheral surface of said first-named die, a vertically movable stretching die for stretching the blank in a region of minimum draw mounted in said clamping die, and means associated with said ram for actuatingsaid stretching die and the vertically movable die in the approach movement of the ram for forming the blank.

6.` Apparatus for die drawing sheet metal articles of irregular'form which consists of' lateral and end hold down surfaces, a hold down Idie gripping the metal-of a blank between it and said surfaces and leaving a central portion free to be drawn, a movable -drawing die movable into engagement with the` sheet to form it, and a stretching die movable independently of the hold-down die to substantially stretch the blank in a region of minimum draw engaged by means associated with the drawing die prior to the nal drawing movement of the drawing die.

'7. Apparatus for'die drawing large irregularly of an elongated blank, a main plunger for drawing the metal of the blank in one direction to the maximum depth of draw, an auxiliary plunger cooperating with the main plunger for drawing the metal independently of the vholding dies from a region of minimum draw simultaneously with the drawing operation of the main plunger to remove excess metal from said region of minimum draw and prevent the formation of Wrinkles in the final stroke of the apparatus, and means for operating said parts in properly synchronized relation.

EDWARD VHOCHREITER, FRANK E. MCGARY.