DE1218848B - Process for forging individual crank lifts, especially for semi-assembled crankshafts - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

B 21k

German class: 49 ir 16

Number: 1218 848

File number: 0100841 b / 49 i

Filing date: April 14, 1964

Opening day: June 8, 1966

The invention relates to a method for hot forging individual crank strokes, with one of the favorable fiber orientation of a volume-based round rod maintaining deformation by upsetting and bending of the cheek areas and subsequent final shaping by flame cutting or chip removal.

According to a well-known drop forging process, a round blank is produced in the first work step pressed flat. In the second step, the crank pin is placed in a die using a punch enforced. The forged fiber, which runs in the longitudinal direction of the blank, is thereby held by the punch partially cut through and the remaining part, corresponding to the crank pin cross section, shifted in parallel. A fiber course that can be described as favorable is achieved by using this deformation process already excluded. In the following, third work step, the one that is partially completed in the die Lifting blank with the help of a holding and internal forming device finish forged. This completely delimits the crank stroke except for the outer plane surfaces and is separable and lockable at the passage for the crank pin. The outer planar surfaces are formed by the tools of an open-die forging press during finish forging, while the Distance between the flat surfaces and the circumference of the crank webs be determined by the holding and internal forming device.

In another known die process, a molding with a longitudinally directed Forged or machined fiber flow, the middle part of which is the Has dimensions of the crank pin and its ends must be thicker, club-like, so for the crank webs are sufficiently large in volume. The production of the molding can according to the process also by upsetting the club-like ends, starting from the cylindrical round rod, take place in a special die. In the second step, the molding is made in a special device bent into a U-shape and in the third step under pure drop forging conditions forged into a finished stroke blank whose mechanical further processing is limited to a minimum remains and whose fiber orientation can be regarded as favorable.

Known methods for largely true-to-size forging of crank strokes thus require high die costs and high forging costs as a result of several work steps after each intermediate heating period, the method being very advantageous for forging individual
Crank strokes, especially for semi-built
Crankshafts

Applicant:

Oehler & Fick G. m. B. H., Weidenau / Sieg

Named as inventor:
ίο Siegfried Geisler, Unglinghausen

Visible, unimpaired and U-shaped fiber orientation can only be achieved with a particularly high level of effort will.

Other known, simpler methods are carried out with little tool effort, but the shape of the Hubrohlings produced is so misshapen that the subsequent mechanical Machining causes significant costs and a considerable impairment of the fiber flow due to high machining is the result. In this process too, there are several forging heats inevitable. In one of these known methods, between several bending steps Scarfing work is still carried out at the bending point, both of which impair the forged fiber as well as a delay in the forging process in addition to the corresponding scarfing costs cause.

The method according to the invention brings the least as a result of the known methods Tool effort and the short deformation time of just one forging heat are significant advantages. It is done so that a heated round rod with about the diameter of the crank pin in a For open die forging known holding and internal forming device clamped in the same Heat only upset under open-die forging tools in upright position, then through eccentric force application between the forging saddles is bent into a U-shape, which is then directly followed by as known per se - the preforming of the crank webs against the middle part of the holding and Interior molding is made. This forging process is followed by the final forming of the Umf on the crank webs by flame cutting or chip removal. The application of these two operations, combined with the somewhat larger expenditure of materials, turn out to be much cheaper than the application well-known, extensive dies and the

609 578/163

required multiple forging heat on a forging press according to known methods the associated heating costs, while the very simple tool used in the method according to the invention is used, in addition to the low manufacturing costs, it also enables short-term dispositions, requires little capital outlay and only depends on the crank pin dimensions, high Universality.

The sequence of the forging process according to the invention is made with the help of the holding and internal forming device (Fig. 1) possible. This device consists of a lower part 1, an upper part 2 and two Bolt 3 for locking the closed device by inserting the bolts 3 into the bores 4. The surfaces 5 are wedge-shaped so that the lower and upper parts are not self-locking into one another can be jammed and are easy to detach from each other. The pins are on the lower part 1 6, the hooks 7 attached to the upper part 2 so that the device can be easily transported by crane or can be turned over and held during the work process, provided a forge manipulator not used. No other facilities are required. Forging with the The device is easy to insert into any open-die forging program with little effort the device can be manipulated freely under a press or hammer, i.e. not wedged or otherwise attached must become.

The procedure for forging a crank stroke is as follows:

According to FIG. 2, a round rod 9 is inserted into the recess 8 of the lower part 1 (Fig. 1) inserted and the upper part 2 inserted. The diameter of the Round rod 9 be so large that the round rod 9 take over centering function for the upper and lower part can. The diameter of the round rod 9 should also be so large that the round rod after closing the Device and insertion of the bolt 3 is clamped, so that the following turning process without the risk of slipping is feasible. The device is clamped by means of a forge crane Round rod 9 turned and from now on held so that the round rod 9 comes in a vertical position. Well will with the aid of the device of the round bar 9 between the forging saddles 10 of a press or a hammer brought and according to FIG. 3 at the discretion of the blacksmith on the basis of a previous calculation or Estimate compressed. By eccentrically pressing or hitting the points 11 according to FIG the compressed round rod 9 bent to a complete U-shape. This is followed by spreading according to FIG. 5 of the crank webs 12 by means of the forging saddles 10. At 90 ° to the stretching direction through the forging saddles If necessary, material is spread out by means of balustrades (not shown).

When forging the crank webs, it is advantageous, but not necessary, to use the width 13 (FIG. 5) of the lower part 1 to execute the raw dimension of the crank strokes in the same extent as the same size, so the knees of the two times 90 ° 'bend are supported by the lower part 1 against the stretching direction of the crank webs so that the part of the crank webs adjoining the crank pin has the shape of the Recess 8 of the lower part 1, according to FIG. 1, can accept and no further processing absolutely necessary. The shape of the recess 8 on the lower part 1 (Fig. 1) must be a segment of a circle downwards describe as it takes on a centering function for the round rod 9. But she becomes the herself usually adapted in the opening direction widening crank web shape. Outside the recess 8 crank webs are produced, which are finished by oxy-fuel cutting or chip removal make necessary. One for a specific crank pin diameter and a fixed distance the inner one. The device provided for flat surfaces is for any shape or size Universal crank web molds. This is all the more important as experience has shown for one type of crankshaft Counterweights of different shapes forged on with the same cross-section of the cheeks can occur.

Claims (2)

Patent claims: 1. Process for the hot forging of individual crank strokes, with a favorable fiber flow of a volume-appropriate round rod maintaining deformation through upsetting and bending of the cheek areas and through subsequent Final shaping by flame cutting or chip removal, characterized in that a round rod with approximately the same diameter of the crank pin in a holding and internal forming device known per se for open die forging clamped and in the same heat exclusively under open-die forging tools in upright position after brief upsetting bent by eccentric force application in the cheek area and then how known per se, for cheek preforming against the central part of the holding and inner forming device is finished compressed. 2. Holding and internal forming device for implementation of the method according to claim 1, which consists of an upper part and a lower part, which by Plug connection are releasably connected to each other and the recesses of the blank in the Clamp the pin area and where crane suspension options are provided, characterized in that that the upper part (2), which is much narrower than the lower part (1), is slightly wedge-shaped and is guided in a correspondingly wedge-shaped groove (5) of the lower part (1). Considered publications:
German Auslegeschrift No. 1133 219, 1101108, 1042 353; "Handelsblatt" magazine, vol. 9, no. 35, March 24th 1954, p. 4. 1 sheet of drawings 609 578/163 5.66 © Bundesdruckerei Berlin