JP2018089658A - Steering knuckle forging preliminary molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering knuckle forging preliminary molding method by which reduction in yielding percentage due to burr generation can be suppressed.SOLUTION: A steering knuckle forging preliminary molding method comprises: sandwiching a heated rod-like coarse material 10 between upsetting dies, namely, an upper die 21 and a lower die 22 to draw a tip of the rod-like coarse material 10 with the upper die 21 having a drawing shape; and simultaneously pushing a punch P1 into a side face of the rod-like coarse material 10 between the upper die 21 and the lower die thereby vending the rod-like coarse material 10. When the punch P1 is pushed into the side face of the rod-like coarse material 10, the punch P1 is lowered in synchronization with the upper die 21.SELECTED DRAWING: Figure 3

Description

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

  The knuckle arm, which is a part of the steering knuckle, is an important part for angling the front wheels of the automobile. The steering knuckle is generally 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 producing a forging material by hot upsetting forging.

JP 2013-27925 A

The inventor has found the following problems with respect to bending, which is forging preforming of a steering knuckle.
FIG. 4 is a schematic cross-sectional view of a bending process of a rod-like rough material by upset forging according to the problem to be solved by the present invention. As shown in FIG. 4, by pressing the punch P2 horizontally while lowering the upper die 31 against the side surface of the rod-like coarse material 10 sandwiched by the upper die 31 and the lower die 32 having a drawing shape, While bending the rough material 10, the tip of the rod-like rough material 10 is drawn. However, this processing method has a problem in that the burrs B are generated on the upper side where the punch P2 is pushed in, and the yield decreases.

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

  In the forging pre-forming method for a steering knuckle according to the present invention, the heated rod-like coarse material is held by an upsetting die composed of an upper die and a lower die. The top end of the rod-like coarse material is drawn with an upper die having a drawing shape, and a punch is pushed into the side surface of the rod-like coarse material between the upper die and the lower die to bend the rod-like coarse material. When the punch is pushed into the side surface of the rod-like coarse material, the punch is lowered while being synchronized with the upper die.

  According to the present invention, it is possible to provide a forging pre-forming method for a steering knuckle that can suppress a decrease in yield due to generation of burrs.

It is a flowchart which shows the forge forming process of the steering knuckle concerning embodiment. It is a model perspective view of the molding material in each step in the middle of forging forming, corresponding to a part of a flowchart showing the forging forming process of the steering knuckle according to the embodiment. In the bending process concerning embodiment, it is the schematic sectional drawing which showed the process in which a punch descend | falls synchronizing with an upper mold | type, when forging and forging a rod-shaped rough material and pushing a punch into a rod-shaped rough material. It is a schematic cross section of the bending process of the rod-shaped coarse material by the upset forging concerning the subject which this invention tends to solve.

  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 embodiment. In addition, the drawings are appropriately simplified for the sake of clarity.

A method for manufacturing a steering knuckle according to the present embodiment will be described with reference to FIGS. 1, 2, and 3.
First, the overall flow of the method for forging a steering knuckle will be described with reference to FIG. FIG. 1 is a flowchart illustrating a method for forging a steering knuckle according to an embodiment. First, the rod-shaped coarse material is heated (step S1), and bending forming (step S2) and crushing forming (step S3) are performed. Bending and crushing are preforms. When forming a steering knuckle having a wide shape with respect to the diameter of the rod-shaped coarse material, the rough material can easily spread to every corner of the mold through pre-forming, thereby suppressing burrs and scratches. Next, rough ground forming (step S4) for forming a rough shape of the steering knuckle is performed. Then, finish molding (step S5) is performed, and trimming (step S6) is performed to manufacture the steering knuckle.

Next, each step will be described in detail with reference to the 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 at each step during forging, corresponding to a part of a flowchart showing a method for forging a steering knuckle according to an embodiment.
First, the rod-shaped coarse material 10 is heated (step S1). In the present embodiment, the rod-shaped coarse material 10 is a rod-shaped aluminum material as shown in the uppermost part of FIG. 2 and heated 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 metal. Furthermore, in the present embodiment, hot forging accompanied by heating of a rod-like coarse material is used as forging, but the forging type may be cold forging or warm forging.

  Next, bending molding (step S2) is performed. In bending, the longitudinal direction of the rod-shaped coarse material 10 is set in the vertical direction. The rod-like coarse material 10 installed in the vertical direction is sandwiched between upper and lower upset molds and processed. The second drawing from the top in FIG. 2 is a schematic perspective view of the bending molded material 11 processed by bending. In the bending molding, the protruding portion 11 a is formed so as to protrude from the longitudinal direction of the bending molded material 11. The protrusion 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 original material diameter of the rod-shaped coarse material 10.

  Here, bending will be described in more detail with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a step in which the punch descends in synchronism with the upper die when the rod-like coarse material is upset and forged and the punch is pushed into the rod-like coarse material in bending according to the embodiment. . The rod-shaped coarse material 10 heated in step S <b> 1 is sandwiched by an upset mold composed of an upper mold 21 and a lower mold 22. Bending is performed simultaneously with two types of processes: (1) draw forming and (2) seat bending.

(1) Drawing Molding The upper die 21 has a drawing shape. In FIG. 3, when the upper mold | type 21 descend | falls in order, the front-end | tip part of the rod-shaped coarse material 10 will be what was drawn. Thus, since the upper mold | type 21 has a drawing shape, it is not necessary to provide the separate process for shape | molding a drawing shape. Therefore, the entire molding time can be shortened, and the temperature drop of the heated rod-like coarse material 10 can be prevented, so that the formability of the rod-like coarse material 10 can be maintained in all steps.

(2) Seat bend forming As described above, the upper die 21 is lowered in (1), the tip of the rod-like coarse material 10 is drawn, and the rod-like coarse material 10 is bent and formed by the punch P1. Done.
“Buckling” is a phenomenon in which a part of an object is suddenly bent when a load of a certain level or more is applied from the upper part of the rod-shaped object. Since the buckling position cannot be controlled, buckling should be avoided by nature. However, in the present embodiment, the buckling position is controlled by lowering the upper die 21 and pushing the bar-like coarse material 10 by the punch P1 from the side surface of the bar-like coarse material 10.

  By further pushing the bent portion by buckling with the punch P1, it becomes possible to spread the rough material to every corner of the wide mold, and the protruding portion 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-like coarse material 10. Further, by using the seat bending, it is possible to perform bending with a lower load.

  Further, when the punch P1 is pushed into the rod-like coarse material 10, the punch P1 is also lowered while being synchronized with the speed at which the upper die 21 of the upsetting mold is lowered. As a result, burrs caused by the pressing of the punch P1 can be prevented, so that the yield can be improved.

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

  Next, wasteland forming (step S4) is performed. In the rough ground molding, like the crushing molding, the longitudinal direction of the rough material is set to be horizontal, and is molded by press working. The lowermost view of FIG. 2 is a schematic perspective view of the wasteland molding material 13 processed by wasteland molding. By the press working, the protruding portion 12a is further stretched to form the protruding portion 13a. Then, after finishing molding (step S5) and trimming (step S6), finally the protrusion 13a becomes a knuckle arm. Through the above steps, a steering knuckle having a knuckle arm is manufactured.

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

  Therefore, in the present embodiment, when the punch is pushed into the side surface of the rod-like coarse material, the punch is lowered while being synchronized with the upper die having a drawing shape. Generation of burrs can be prevented by lowering and processing the punch and the upper die in synchronization. Therefore, the steering knuckle forging preforming method according to the present embodiment can provide a steering knuckle forging preforming method that suppresses a decrease in yield due to the occurrence of burrs.

  Furthermore, the molding time can be shortened by simultaneously performing the bending process and the drawing process. By reducing the molding time, it is possible to prevent the temperature of the heated coarse material from being lowered, so that the moldability can be maintained.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

10, 100 Bar-shaped rough material 11, 101 Bending molding material 12 Crushing molding material 13 Wasteland molding material 11a, 12a, 13a Protruding portion 21, 31 Lower die 22, 32 Lower die P1, P2 Punch B Burr

Claims (1)

The heated rod-like coarse material is sandwiched by an upset die composed of an upper die and a lower die, and the tip of the rod-like coarse material is drawn with the upper die having a drawn shape, and the upper die and the A forging preforming method for a steering knuckle, in which a punch is pushed into a side surface of the rod-like coarse material between a lower die and the rod-like coarse material is bent,
When the punch is pushed into the side surface of the rod-like coarse material, the punch is lowered while being synchronized with the upper die,
Steering knuckle forging preforming method.

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