JP6642397B2 - Forging preforming method of steering knuckle - Google Patents

Description

  The present invention relates to a method for forging preforming of a steering knuckle.

  The knuckle arm, which is a part of the steering knuckle, is an important component for angling the front wheels of the vehicle. Generally, a steering knuckle is formed by forging. The knuckle arm takes a wide shape with respect to the diameter of the rod-like coarse material before forging. Patent Document 1 discloses a method for manufacturing a forged material by hot upsetting.

JP 2013-27925 A

The inventor has found the following problems with regard to bending, which is forging preforming of a steering knuckle.
FIG. 4 is a schematic cross-sectional view illustrating bending of a bar-shaped coarse material by upsetting forging according to a problem to be solved by the present invention. As shown in FIG. 4, the punch P2 is pressed horizontally against the side surface of the bar-shaped rough material 10 held by the upper die 31 and the lower die 32 having a drawing shape while lowering the upper die 31 to thereby obtain a rod-like shape. While the bending process for buckling the rough material 10 is performed, the drawing process of the distal end portion of the rod-shaped rough material 10 is performed. However, this processing method has a problem that burrs B are generated on the upper side where the punch P2 is pushed in, and the yield is reduced.

  The present invention has been made in view of the above-described problems, and provides a forging preforming method for a steering knuckle that can suppress a decrease in yield due to generation of burrs.

  In the forging preforming method for a steering knuckle according to the present invention, the heated bar-shaped coarse material is held by an upsetting die including an upper die and a lower die. The tip of the bar-shaped coarse material is drawn with an upper die having a drawn shape, and a punch is pushed into the side surface of the bar-shaped coarse material between the upper die and the lower die to bend the rod-shaped coarse material. When the punch is pressed into the side surface of the bar-shaped coarse material, the punch is lowered while being synchronized with the upper die.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a steering knuckle forging preforming method capable of suppressing a decrease in yield due to burr generation.

It is a flowchart which shows the forging process of the steering knuckle concerning embodiment. It is a typical perspective view of the forming material in each step in the middle of forging, corresponding to a part of the flow chart showing the forging process of the steering knuckle according to the embodiment. FIG. 5 is a schematic cross-sectional view showing a process of upsetting and forging a bar-shaped coarse material and lowering the punch while synchronizing with an upper mold when pushing a punch into the rod-shaped coarse material in the bending according to the embodiment. FIG. 3 is a schematic cross-sectional view of bending a bar-shaped coarse material by upsetting forging according to a problem to be solved by the present invention.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. In addition, in order to clarify the description, the drawings are simplified as appropriate.

A method of manufacturing a steering knuckle according to the present embodiment will be described with reference to FIGS.
First, an overall flow of a forging method of a steering knuckle will be described with reference to FIG. FIG. 1 is a flowchart illustrating a forging method of a steering knuckle according to the embodiment. First, the bar-shaped coarse material is heated (Step S1), and is subjected to bending (Step S2) and crushing (Step S3). Bending and crushing are preforms. In forming a steering knuckle having a wide shape with respect to the diameter of the rod-shaped coarse material, the rough material can be easily spread to every corner of the mold by performing pre-forming, so that burrs and scratches can be suppressed. Next, rough land forming (step S4) for forming a rough shape of the steering knuckle is performed. Then, finish forming (step S5) and trimming (step S6) are performed to manufacture a steering knuckle.

Next, each step will be described in detail with reference to a schematic perspective view of FIG. 2 corresponding to a part of the flowchart of FIG. FIG. 2 is a schematic perspective view of a molding material in each step during forging, corresponding to a part of a flowchart showing a method for forging a steering knuckle according to the embodiment.
First, the rod-shaped coarse material 10 is heated (Step S1). In the present embodiment, as the rod-shaped coarse material 10, a rod-shaped aluminum material as shown in the uppermost part of FIG. 2 is used, and heating is performed at about 500 ° C., but the rod-shaped coarse material 10 can be processed. Any metal may be used as long as it is a metal, and the heating temperature is appropriately determined depending on the type of the metal. Further, in the present embodiment, hot forging accompanied by heating of the bar-shaped coarse material is used as forging, but the type of forging may be cold forging or warm forging.

  Next, bending (Step S2) is performed. In the bending, the longitudinal direction of the rod-shaped coarse material 10 is set in the vertical direction. The bar-shaped coarse material 10 installed in the vertical direction is clamped and processed into an upright upright type. The second diagram from the top in FIG. 2 is a schematic perspective view of the bent material 11 processed by bending. In the bending, the protrusion 11a is formed so as to protrude from the longitudinal direction of the bent material 11. The protruding portion 11a is further stretched in the processing after the bending, and becomes a knuckle arm of a steering knuckle having a wide shape with respect to the initial material diameter of the rod-shaped coarse material 10.

  Here, the bending will be described in more detail with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a process of upsetting and forging a bar-shaped coarse material and lowering the punch while synchronizing with the upper mold when pushing the punch into the rod-shaped coarse material in the bending according to the embodiment. . The rod-shaped coarse material 10 heated in step S <b> 1 is clamped by an upsetting die including an upper die 21 and a lower die 22. In the bending, two kinds of processes of (1) drawing and (2) bending of the seat are simultaneously performed.

(1) Drawing The upper die 21 has a drawing shape. In FIG. 3, as the upper die 21 descends in order, the leading end of the rod-shaped coarse material 10 is drawn. As described above, since the upper die 21 has the drawn shape, there is no need to provide another step for forming the drawn shape. For this reason, the entire molding time can be shortened, and the temperature of the heated rod-shaped coarse material 10 can be prevented from lowering, so that the formability of the rod-shaped coarse material 10 can be maintained in all steps.

(2) Shaft bending forming As described above, the upper die 21 descends in (1), the tip of the bar-shaped rough material 10 is drawn, and the seat bent forming of the rod-shaped rough material 10 by the punch P1 is performed. Done.
"Buckling" is a phenomenon in which a part of an object is sharply bent when a certain load or more is applied from above the rod-shaped object. Buckling is inherently to be avoided because the buckling position cannot be controlled. However, in the present embodiment, the buckling position is controlled by lowering the upper die 21 and pushing the rod-shaped coarse material 10 by the punch P1 from the side surface of the rod-shaped coarse material 10.

  By pushing the part bent by buckling further with the punch P1, it becomes possible to spread the coarse material to every corner of the wide mold, and the projection 11a is formed. The protrusion 11a finally becomes a knuckle arm of a steering knuckle having a wide shape with respect to the initial material diameter of the rod-shaped coarse material 10. In addition, by using the seat bending forming, it is possible to perform bending forming with a lower load.

  Further, when the punch P1 is pushed into the bar-shaped coarse material 10, the punch P1 is also lowered while being synchronized with the speed at which the upsetting upper die 21 is lowered. Thus, burrs due to the pressing of the punch P1 can be prevented, so that the yield can be improved.

  Next, flattening (step S3) is performed. In crushing, the coarse material is placed so that the longitudinal direction is horizontal, and is formed by press working. The third figure from the top in FIG. 2 is a schematic perspective view of the crushed material 12 processed by crushing by press working. By pressing, the protruding portion 11a is stretched to form the protruding portion 12a.

  Next, rough land forming (step S4) is performed. In the rough land forming, similar to the crushing forming, the rough material is installed so that the longitudinal direction thereof is horizontal, and is formed by press working. The lowermost view in FIG. 2 is a schematic perspective view of the rough land forming material 13 processed by the rough land forming. By the pressing, the protruding portion 12a is further stretched to form the protruding portion 13a. Thereafter, after the finish forming (step S5) and the trimming (step S6), the projection 13a finally becomes a knuckle arm. Through the above steps, a steering knuckle having a knuckle arm is manufactured.

  In the bending by buckling shown in FIG. 4, a punch is pressed horizontally into the side surface of the rod-shaped coarse material held by the upper die and the lower die. For this reason, burrs are generated on the upper side where the punch is pushed in, and there is a problem that the yield is deteriorated.

  Therefore, in the present embodiment, when the punch is pressed into the side surface of the bar-shaped coarse material, the punch is lowered while synchronizing with the upper die having the drawing shape. When the punch and the upper die are moved down in synchronization with each other and processed, the occurrence of burrs can be prevented. Therefore, the forging preforming method for a steering knuckle according to the present embodiment can provide a forging preforming method for a steering knuckle that suppresses a decrease in yield due to the generation of burrs.

  Further, by simultaneously performing the bending and the drawing, the molding time can be shortened. Since the molding time is short, it is possible to prevent a decrease in the temperature of the heated rough material, so that the moldability can be maintained.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist.

10, 100 Bar-shaped coarse material 11, 101 Bent formed material 12 Crushed formed material 13 Wasteland formed material 11a, 12a, 13a Projection 21, 31 Upper mold 22, 32 Lower mold P1, P2 Punch B Burr

Claims (1)

The heated bar-shaped coarse material is clamped by an upsetting die consisting of an upper die and a lower die, and the tip of the rod-shaped coarse material is drawn by the upper die having a drawn shape, and the upper die and the upper die are formed. Pushing a punch into the side surface of the rod-shaped coarse material between the lower mold and bending the rod-shaped coarse material, a forging preforming method of a steering knuckle,
When pushing the punch into the side surface of the rod-shaped coarse material, the punch is lowered while being synchronized with the upper mold,
Forging preforming method for steering knuckle.

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