US2239203A - rendleman - Google Patents

Description

April 22, 1941. N. c. RENDLEMAN 2,239,203 METHOD OF: MAKING STEERING KNUCKLES Original Filed July 9', 1958 2 sheets-sheet 1 INVENTOR I 4 M NormanCfiend/eman Z5 25' 25 April 1941- N. c. RENDLEMAN 2,239,203

METHOD OF MAKING STEERING KNUCKLES Original Filed July 9, 1938 2 Sheets-Sheei 2 INVENTOR /I/0//77a/7 CZ M no/W278 kZM /LJZ atenteol Apr. 22, 1941 METHOD OF MAKING STEERING KNUCKLES Norman C. Rendleman, Pittsburgh, Pa, assignor to Jones and Laughlin Steel Corporation, a corporation of Pennsylvania Original application July 9, 1938, Serial No.

218,454. Divided and this amllication Novemher 18, 1940, Serial No. 366,169

3 Claims. (Cl. 29-152) This invention relates to the manufacture of forged articles, and, in particular to a method of making steering knuckles by rolling a bar of special shape in section and forging short lengths thereof.

application, Serial No. 218,454 filed July 9, 1938, forForging blank for steering knuckles.

Steering knuckles have been manufactured ?"5 This is a division carved from my co-pendmg heretofore by a series of forging operations per-(I formed on a work piece which is originally in the form of a short length of a billet of square section. The length is first reduced at one end to provide a tong hold and is then subjected to a series of forging operations in a plurality of different shaping dies. Twelve forging blows in all are necessary for making a forged knuckle by the prior method and, of the weight of the initial work piece, forty-four per cent is removed as scrap.

I have invented a novel method of making steering knuckles by forging, which is simpler, quicker and less costly than the former method. By my invention, I am able to convert a blank into a forged steering knuckle with one or two forging blows and the amount of scrap to be removed is only about fourteen per cent of the initial weight of the blank. In a preferred form, the blank comprises a short length of a rolled section of substantially Y-shape, the upper ends of the section being enlarged to provide spaced metal masses connected by a web of relatively reduced section, with a rib or stem projecting from the web in the opposite direction from said masses. The blank is formed by rolling a bar of suitable shape and cutting it into appropriate lengths. For a complete understanding of the invention, reference is made to the accompanying drawings illustrating a preferred embodiment and practice of the invention. In the drawings:

Fig. l is an end View in perspective of a bar in accordance with my invention adapted to provide a plurality of short lengths having metal masses spaced appropriately for the forging of steering knuckles;

Fig. 2 is a side elevation of a forged steering knuckle with the forging flash thereon;

Fig. 3 is a plan view of a finished steering knuckle;

Figs. 4 and 5 are side and end views thereof;

and

Figs. 6, 7, 8 and 9 show roughly the successive steps in the manufacture of the bar shown in Fig. 1.

Referring in detail to the drawings, the first step in the manufacture of steering knuckles, in

accordance with the invention, is the rolling of an elongated bar H] of suitable sectional shape to provide masses of metal appropriately spaced to fill the dies wherein steering knuckles are forged. As shown in Fig. Lthe bar Hi is roughly of Y-shape, the upper endsof the section being enlarged as at H and i2, and connected by a relatively thin web I3.

A rib I l projects outwardly from the web lit in a direction opposite from the masses H and [2. The rib I 4 is disposed substantially centrally of the web it although not precisely so.

Considered in a slightly different light, the bar it might be'described as a special bar the section of which is of generally Y-shape, wider than it is deep, with enlarged, bulbous, upper extremities thicker than the mid-portion, and a rib extending downwardly from the mid-portion. Regardless of how the bar It is described, it will be recognized that it constitutes roughly a channel section with flanges thickened adjacent their outer edges and a rib projecting outwardly from the web.

The bar It may be produced in convenient lengths by known methods of "rolling so it is unnecessary to make a detailed disclosure of the successive rolling operations. It will suffice to refer to Figs. 6-9 showing roughly the steps by which a billet of square section may be reduced by ordinary rolling procedure to a bar such as shown at Ill. The important feature of this portion of the invention is that the center of the billet shown at 25, which contains the segregations and defects from the parent ingot is so distributed as shown in Fig. 9, that such defects are almost obliterated and without adverse effect upon the resulting blank or the knuckle forged therefrom. This is in contrast to the prior practice according to which the center of the billet extends axially of the knuckle spindle.

Short sections, of a length indicated by dotted lines l5, when out from the bar it, constitute blanks from which steering knuckles such as shown in Figs. 3 through 5 may readily be formed by one or two forging operations. Referring for a moment to the figures last mentioned, it will :be observed that the knuckle there shown comprises a spindle l6 and a yoke portion ll substantially at right angles thereto terminating in bearing sockets I8 and [9 adapted to receive the king bolt of a tilting wheel mounting. Lugs 23 extend outwardly from the sockets and are drilled as at 2| to receive bolts for securing the brake drum and assembly to the knuckle. The dotted lines in Figs. 3 through 5 show the portion of the forged knuckle that is removed in machining it to accurate dimensions and performing other finishing operations thereon.

Fig. 2 shows a steering knuckle forged from a blank cut from a bar such as shown at Ill, before the forging flash indicated at 22 has been trimmed therefrom. The forged knuckle is produced by one or two blows on a blank such as that indicated generally at 23, by the forging dies used heretofore to perform the finishing forging operation. A single blow of such dies usually sufiices to reduce the blank 23 to the condition illustrated in Fig. 2, although a second blow may be desirable in some cases. The shape of the blank 23 is such as to provide sufficient flash to cause the dies to fill fully and completely and to avoid cold shuts. It will be understood that the spaced masses ii and i2 provide metal for forming the bearing sockets i8 and I9 and the lugs 28. The web l3 furnishes the metal necessary to form the yoke l4 while the rib or stem portion of the blank indicated at 24 furnishes the metal necessary to form the spindle Hi.

It will be noted that in forging the blank 23, the pressure exerted by the dies is parallel to the rolling direction of the blank. Forging blanks have heretofore been compressed between forging dies along a line transverse to the rolling direction of the blank but I believe I am the first to adopt the procedure of disposing a' blank in the dies with its direction of rolling in the line along which forging pressure is exerted. This procedure appears to result in the production of a sounder and stronger forging than would be produced by the former practice. Forgings made by the prior practice exhibit irregular flow lines indicating excessive distortion. Forgings made in accordance with the invention show smooth flow lines indicating a minimum distortion consistent with the desired shaping effect.

When the forging shown in Fig. 2 has been subjected to a flash trimming operation, it is then ready for the machining and other finishing operations necessary to convert it into final form;

as shown in Figs. 3 through 5.

It will be apparent that the invention is characterized by numerous advantages over the previous method for the formation of steering knuckles. is the great reduction in the amount of scrap which has already been mentioned, viz., from forty-four per cent by the old method to about fourteen per cent by the practice described herein. which the knuckle is forged weighs less than the starting blank used in the prior method. Likewise a greater number of blanks may be produced from a given weight of metal. The reduction in the weight of the blank means that the blank can be heated more quickly, thus making it possible to obtain greater production with the same blank heating equipment.

The reduction in the number of forging blows from fourteen under the old method to one or two under the practice described is another highly important advantage since it reduces the labor cost per unit as well as the die cost. The wear on the dies per forging is reduced in proportion to the reduction in the number of blows and only a single set of dies is necessary to convert the blank into a finished forging as compared with several sets used under the old method. The reduction in the number of forging blows required Perhaps the most important of these,

This means that the original blank from further increases the output obtainable with existing forging equipment.

A further advantage of the invention has already been mentioned, viz., the disposition of the defects of the parent ingot such as segregations, pipes, etc., which, despite all efiorts to the contrary, persist in the product of the final rolling, being located at the axial center of the mass of metal regardless of its shape. Such defects are shown exaggerated in Figs. 6 through 9 at 25. The forging operations towhich the blanks of my invention are subjected, bring the defective center to the surface of the forging and tend to spread it along the length of the portion of the forging which is to form the yoke H of the finished knuckle. The metal of which the spindle is formed is sound and free from all defects.

In contra-distinction to the foregoing, the ingot defects carried over into the billets used heretofore for forging knuckles remain unaffected in about the same location, even after the final forging. Instead of being brought to the surface of the yoke H, the defects lie at the center of the spindle portion of the knuckle Where they may 'seriously imp-air the strength of the finished knuckle.

Blanks for various designs of knuckles may be made of bars differing somewhat in shape from the bar Hi, depending on the requirements of any 0 given design of knuckles.

Although I have illustrated and described but a preferred embodiment and practice of the invention, it will be understood that changes in the article or procedure disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1, In a method making a steering knuckle having spaced, alined bearing sockets connected by a yoke portion from which a spindle extends laterally, the steps including rolling a long bar generally Y-shaped in section, having bulbous enlargements adjacent the ends of the forked portion and a tape-ring rib forming the stem of the Y, severing the bar into short lengths and subjecting one of the lengths to die forging blows thereby forming said enlargements into said sockets and said rib into said spindle, while shaping the metal between said enlargements and said rib to form said yoke.

2. In a method of making a steering knuckle having spaced, alined bearing sockets connected by a yoke portion from which a spindle extends laterally, the steps including rolling a. long bar generally Y-shaped in section, having bulbous enlargements adjacent the ends of the forked portion and a tapering rib forming the stem of the Y, severing the bar into short lengths, and subjecting one of the lengths to die forging blows relatively small in number compared to the number necessary to forge a knuckle from plain stock, thereby forming said enlargements into said sockets and said rib into said spindle, while shaping the metal between said enlargements and said rib to form said yoke.

3. The method of making steering knuckles, which comprises rolling a bar Y-shaped in section having flanges connected by a Web, the flanges being thicker than the web and having a tapered rib projecting from the web, cutting the bar into short lengths, and forging said lengths into steering knuckles.

NORMAN C. RENDLEMAN.

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