JP4771048B2 - Roll type - Google Patents

Description

The present invention relates to a roll type, and in particular relates to aluminum-based stick-shaped material in a roll type to perform a predetermined process of the roll-type group of pre-formed into a predetermined shape by a plurality of steps.

  For example, when manufacturing parts with a large diameter difference in the axial direction, such as steering knuckles and connecting rods for automobile parts, by stamping forging, a deformed rod-shaped rough material is usually preformed by roll forging, and this roughing is performed. The shape material is subjected to die forging (see, for example, Patent Document 1). Moreover, in the automotive parts manufactured by such stamping forging, the hot roll which performs roll forging in the state heated, for example to about 410-460 degreeC, using the aluminum-type raw material for the objective of weight reduction etc. A rough shape is preformed by forging.

  FIG. 6 shows the final shape of the rough material W used for the steering forging of the steering knuckle. The large-diameter portion 2 is on one end side, the small-diameter portion 3 is on the middle, and the other end side is stepped. Each has a diameter portion 4 and has a shape in which the large diameter portion 2 and the small diameter portion 3 are connected to each other and the small diameter portion 3 and the medium diameter portion 4 are connected to each other by taper portions 5 and 6. By positioning and placing the rough shaped member W on the forging die and stamping and forging, the material is sufficiently filled up in the impression, and the product A has a steering knuckle having a desired shape as shown in FIG. Can be obtained.

Here, in the roll forging for forming the rough shaped material W, as shown in FIG. 8, a pair of roll dies 11 ′ and 12 ′ having a hole mold part 10 on a part of the outer peripheral surface are reversed. This is carried out through a heated rod-shaped material W ₀ whose one end is supported by a manipulator 13 in the hole mold 10 of the rotating roll molds 11 ′ and 12 ′.
In this case, it is difficult to mold the rough profile W of final shape in a single rod-shaped material W _0. Therefore, in general, for example, a plurality of roll mold groups are prepared, such as arranging a plurality of hole mold portions 10 at a predetermined pitch in the axial direction of roll molds for forming the rough shaped members W _{1 to} W at each stage. Then, crossfeed by a predetermined pitch while rotating the rough profile W ₁ to _W-3 90 degrees by the manipulator 13, respectively for each role type.
As shown in FIG. 9, in the conventional general role forging, carried rod-like material W _{0 (a)} the ellipses of circular cross-section shape shaping the rough profile W ₁ of the (oval) shape (b) (First pass), a step (c) is performed in which the rough shaped material W ₁ is displaced 90 degrees around its axis to form a rough shaped material W ₂ ′ having a rectangular or rhombus (square) shape (second pass). ), such a coarse profile W _{2 'is} 90 degrees displaced in its axial around perform step (d) of forming the coarse profile W ₃ cross-sectional oval shape (the third pass), then such a coarse profile W A rough shape of a desired shape is obtained by a plurality of processes, such as performing a step (e) of preliminarily forming a rough shaped material W having a circular cross section by displacing ₃ around its axis 90 degrees (fourth pass). The material W is formed. Note that the portion of the rod-shaped material W ₀ gripped by the manipulator 13 remains as an unformed portion, but this unformed portion becomes the large-diameter portion 2 of the rough shaped material W as it is.

By the way, in the conventional roll forging shown in FIG. 9, in the second pass, the roll die 11 ′ in the step (c) of forming the coarse shaped material W _{1 having} an oval cross section into a square shaped material W ₂ ′, the shape of 12 'grooved portion 10', as shown in (a) ~ (c) of FIG. 10, Sokatachizai W ₂ 'apex cross-sectional square shape of the groove bottom 10a' is arranged to be located Square hole type.
Then, the square hole type hole portion 10 ′ is engraved so as to form an inclined surface 10b ′ that linearly extends from the groove bottom 10a ′ toward the parting surfaces 10c ′ of both roll types. In the roll dies 11 ′ and 12 ′ configured as described above, one end is held by the manipulator 13 in a state in which the rough shaped material W ₁ which is formed in an oval cross section and is displaced 90 degrees around its axis is held. It arrange | positions between both roll type | molds 11 'and 12' ((a) of FIG. 10).
Then, the rolls type 11 ', 12' of both rolled 11 Sokatachizai W ₁ while rotating in opposite directions to each other ', 12' through between the grooved portion 10 ', the Sokatachizai W ₁ The end portion L in the longitudinal direction of the cross section is pressed (FIG. 10B). At the beginning of roll forging in this step, the end portion L in the longitudinal direction of the cross section W ₁ is pressed by the vicinity of the groove bottom 10a ′ of the hole mold portion 10 ′, and then the groove bottom 10a ′ of the roll dies 11 ′ and 12 ′. And gradually expands in the lateral direction (refer to the arrows), and is deformed plastically so that the material of the rough shaped member W ₁ flows in the axial direction, corresponding to the shape of the hole portion 10 ′. A rough material W ₂ ′ having a square cross section is formed ((c) of FIG. 10).

Japanese Utility Model Publication No. 5-60636

However, as shown in FIG. 10, at the beginning of forming a rough shaped material W ₂ ′ having a cross-sectional square shape from a rough shape material W _{1 having a} cross-sectional shape into a square-shaped roll shape 11 ′, 12 ′, W _A gap K is formed between the end portion L in the longitudinal direction of the cross section ₁ and the groove bottom 10a ′ of the hole mold portion 10 ′. When W ₁ is pressed by the hole mold portions 10 ′ of the roll dies 11 ′ and 12 ′, the material of the end portion L in the longitudinal direction of the cross section W ₁ flows into the gap K, while the rough shape W The material at the center of the cross section of ₁ flows in the axial direction and the end face protrudes. Therefore, the end surface W ₂ a ′ of the formed rough shape member W ₂ ′ is projected from the center as shown in the photograph in FIG. The position corresponding to the groove bottom 10a 'of 10' can be pulled without overhanging.
When such third pass of the crude shaped product W ₂ 'which is formed (in FIG. 9 (d) is the reference) around the axis by 90 ° displaced in forming the crude profile W ₃ cross-sectional oval shape, As the material of the portion where the shrinkage occurs flows so as not to flow in the axial direction but spread in the lateral direction, as shown in the photograph in FIG. 12, the portion corresponding to the closed portion of the end face W ₂ a ′ further shrinks. The rough shape W ₃ ′ at the end W ₃ a ′ is formed. Thereafter, the rough shaped material W ₃ ′ is displaced 90 degrees around its axis in the fourth pass to form a final rough shape W having a circular cross section. As shown in FIG. A clear ridge line J is formed between the closed portion of the end portion Wa ′ of W ′ and the side surface. 14 is formed into a predetermined shape such as a steering nack as a product A by subsequent stamping forging, as shown in FIG. 15, the ridge line J is formed. Remains in the part constituting the shape of the product A as a scratch J ', which causes a quality problem. Such a problem occurs remarkably when roll forging an aluminum-based material.

The present invention has been made in view of the above-described conventional problems, and the problem is that when an aluminum-based rod-shaped material is preformed into a predetermined shape by roll forging, it has a simple structure and is attached to the end portion. An object of the present invention is to provide a roll mold in which a closed portion is generated and becomes a ridgeline and does not remain as a scratch on a product.

In order to solve the above-mentioned problems, the invention according to the roll mold of claim 1 is a roll mold in a pre-process for forming a pre-rough shape material having an oval cross section in an aluminum-based rod-shaped material,
A roll mold of the step of forming the rough profile having a circular cross section by displacing the front rough profile and pressing the longitudinal end of the cross section;
A pre-rough shape in a group of roll molds, which includes a roll mold in a post-process for forming a post-rough shape member having a cross-sectional oval shape by displacing the rough shape member, and preforming the rod-shaped material into a predetermined shape A roll mold of a step of forming a rough cross-sectional material by pressing a cross-sectional longitudinal end of the material,
There is a hole mold part on the outer peripheral surface, and the hole mold part is pressed without causing a gap between the end part in the cross-sectional longitudinal direction of the oval-shaped pre-rough shape material, The material of the material is engraved so as to flow in the transverse direction in the cross section and in the axial direction of the rod-shaped material to form a rough shaped material with a circular cross section ,
The roll mold is recessed at the groove bottom of the hole mold portion with the same width as the width of the end portion in the longitudinal direction of the cross section of the previous rough shape formed in the previous step, and the front of the cross section oval shape is formed. It has a holding part which hold | maintains and presses the edge part of this cross-sectional longitudinal direction, without producing a clearance gap between cross-sectional longitudinal direction edge parts of a rough shaped material .

According to the first aspect of the present invention, a roll is formed so as to form a pre-rough shape with a cross-sectional oval shape by roll forging from an aluminum rod-shaped material, and to displace the front rough shape around its axis and press the end in the longitudinal direction of the cross-section. Forging to form a rough section with a circular cross section. At the groove bottom of the roll-type hole portion, there is a holding portion that holds the end portion in the longitudinal direction of the cross-section oval-shaped pre-rough shape material. It is recessed with the same width as the width of the cross-sectional longitudinal end of the front rough profile so as to be held and pressed without any gap between it and the cross-sectional longitudinal end. Therefore, in the state where the holding portion abuts the end portion in the longitudinal direction of the cross-sectional oval shape of the cross-section oval shape without gaps and starts positioning, the material of the pre-rough shape material in the lateral direction in the cross-section, The rod-shaped material can be made to flow uniformly in the axial direction, and as a result, the end face of the rough shaped material is uniformly stretched without being partially pulled, so that the end of the preformed final rough shaped material is A ridgeline is not generated, and therefore a product is not damaged in a subsequent process such as stamping and forging. And since the cross-sectional longitudinal direction edge part of a front rough shape material is hold | maintained at the holding | maintenance part of a hole mold | type part, it becomes easy to sit down, and a cross-section oval shape which a front rough shape material becomes difficult to buckle by pressing force and shape | molds in the 1st pass. Since the thickness can be reduced, the molding efficiency is good, and the pre-rough shape does not escape due to the pressing force.

According to the first aspect of the present invention, the roll die holds the end portion in the longitudinal direction of the cross section of the previous rough profile which has been deformed and formed into an oval cross section in the previous step at the groove bottom of the hole mold portion. The holding portion has the same width as the end of the cross-section longitudinal direction of the front rough profile without a gap between the end of the cross-section oval shape of the cross-section oval shape and the end of the cross-section longitudinal direction. Since the end of the cross section in the longitudinal direction of the rough profile is reliably positioned and pressed because it is recessed with a width, the pre-rough profile does not escape due to the pressing force. Since the material is less likely to buckle and the thickness of the cross-sectional oval shape formed in the first pass can be reduced, the molding efficiency is good. presses without cross longitudinal end and a gap is generated, the previous coarse profile Fee shaping the thickness direction and the axial direction uniformly without force by flow vortex type grooved portion shape with the corresponding rough profile of circular section shape with the. And, since a ridgeline does not occur at the end of the final shaped rough material, a roll mold that does not cause scratches in a product formed in a subsequent process such as stamping and forging is provided. Can do.

First, an embodiment of the roll dies 11, 12 of the present invention will be described mainly based on FIG. In the drawings, the same reference numerals are given to similar or corresponding parts. In this embodiment, as shown in FIG. 9, a final rough shape W for manufacturing a steering knuckle having a shape as shown in FIG. is intended process for preforming an aluminum-based stick-shaped material W ₀ by roll forging (path), the final preformed coarse profile W is shaped as shown in FIG. 6, the present invention A case will be described in which the roll dies 11 and 12 are for performing the second pass step as shown in FIG. 9C.
The roll dies 11 and 12 of the present invention generally perform a predetermined process of a roll mold group for preforming an aluminum-based rod-shaped material W ₀ into a predetermined shape by a plurality of processes. In the case of the first pass), the pre-rough shaped material W ₁ whose cross section is formed into an oval shape is displaced and the end in the longitudinal direction of the cross section is pressed. It rolled 11 step (second pass) of molding the crude profile W ₂ for being molded into W ₃ is intended for molding the rough profile W ₂ of cross land shape.

Since the overall structure of the roll dies 11 and 12 in this embodiment is the same as that shown in FIG. 8, the same reference numerals are given to the same parts, and the description thereof is omitted. As shown in FIG. 1, in the roll dies 11 and 12 in this embodiment, each hole part 10 has a cross-sectional land (circular) shape with a radius R from a rough shaped material W ₁ formed into a cross-sectional oval shape. to shape the Sokatachizai W _2, it is formed into an arc shape.
The boundary 10e between the grooved portion 10 and the parting surface 10c is so never chew coarse profile W ₁ formed into cross-sectional oval shape when plastically deformed by roll forging, a predetermined continuous smooth It is formed in a so-called round shape with a radius.
In addition, the cross-sectional area S of the rough shaped material W ₂ formed into a cross-sectional land shape by the roll dies 11 and 12 of the present invention has a square cross-sectional shape by the conventional square hole dies 11 ′ and 12 ′ as shown in FIG. It is set to be the same as the cross-sectional area s of the rough shaped material W ₂ ′ formed into the above.

In the roll molds 11 and 12 configured as described above, as shown in FIG. 9B, the rough shape material W ₁ having a predetermined temperature formed in the cross-sectional oval shape in the first pass is supplied to the manipulator 13 (FIG. 8). ) And the roll molds 11 and 12 are rotated in opposite directions to press the end portions L in the longitudinal direction of the cross section by the hole mold part 10. Molded so that the cross section of ₁ spreads in the horizontal direction and has a cross-sectional land shape.
Here, compared with the roll-type 11 and 12 of the present invention, the prior art 'rolled 11 for molding the' cross-sectional square roughness profile W ₂ form as described in (FIG. 10), and a 12 '. In the conventional roll molds 11 ′ and 12 ′ for forming the rough shaped material W ₂ ′ having a square cross section, as described above (see FIG. 10B), the cross section longitudinal end L of the rough shaped material W ₁ and Since the material flows in the gap K generated between the hole mold part 10 'and the groove bottom 10a', the flow in the axial direction of the cross-section longitudinal end L is reduced, and corresponds to the cross-section longitudinal end L. The overhang of the end face W ₂ a ′ is reduced as compared with the central portion, and the shrinkage occurs.
In contrast, in the roll-type 11 and 12 of the present invention, the caliber portion 10 are engraved in a circular arc shape, that gap is formed between the cross-sectional longitudinal end L of Sokatachizai W ₁ Therefore, the material of the rough shaped member W ₁ flows evenly in the axial direction, and as a result, the overhang of the end face W ₂ a of the formed rough shaped member W ₂ becomes uniform and no shrinkage occurs. . Accordingly, since the ridge line J (see FIG. 14) is not formed on the rough shaped material W finally preformed as in the prior art, a product such as a steering knuckle that is manufactured later by die forging. A scratch J ′ (see FIG. 15) no longer remains on A.

Next, another embodiment of the roll type of the present invention will be described in detail mainly based on FIG. Portions that are the same as or correspond to those in the above-described embodiment are given the same reference numerals, and descriptions thereof are omitted.
In addition to the configuration of the above-described embodiment, the roll dies 11 and 12 of the present invention have the longitudinal section L in the longitudinal direction of the front rough shape W ₁ formed into an oval shape and displaced 90 degrees around the axis in the previous step. A holding part 10 a that is held during roll forging is formed in the hole mold part 10.

The holding portion 10a is recessed in the bottom surface (vertex) of the hole mold portion 10 of the roll dies 11 and 12, and as shown in FIG. 2, a rough shaped material W formed into a cross-section oval shape in the first pass. virtual line F that distributed to the left and right of the center line Y ₁ of the width T1 of the longitudinal ends L (see FIG. 3), the intersections of the arcuate surface 10b of the radius R of G and grooved portion 10 M, and N, It is formed in an arc shape passing through a point P offset by a predetermined amount H on the center line Y with respect to the extended line of the arc surface 10b of radius R. The depth of the holding portion 10a with respect to the circular arc face 10b of the radius R of the grooved portion 10 (offset amount), or cross-sectional shape, including size of the arc through the point M, P, and N is the cross-section of Sokatachizai W ₁ It can be set according to the shape of the longitudinal end L. The boundary portion between the holding portion 10a of the hole mold portion 10 and the circular arc surface 10b having a radius R has a so-called round shape having a predetermined radius. The portion extending from the arcuate surface 10b on the parting surface 10c of the grooved portion 10, so as not to chew Sokatachizai W _1, so that a straight line having a predetermined angle α with respect to cross section parting surface 10c A straight surface 10d is formed, and the straight surface 10d and the parting surface 10c are formed so as to be smoothly continuous in a so-called round shape having a predetermined radius. Incidentally, the sectional area S of the coarse profile W ₂ which is formed into a cross-sectional land shape by a roll-type 11 and 12 of the present invention, like the embodiment described above, as shown in FIG. 4, a conventional cross-sectional square shape It is set to be the same as the cross-sectional area s of the rough shaped material W ₂ ′ formed into the above.

In the roll molds 11 and 12 formed in this way, as shown in FIG. 9B, the rough shape material W ₁ having a predetermined temperature formed into a cross-sectional oval shape in the first pass is used as the manipulator 13 (FIG. 8). Thus, it is gripped in a state where it is displaced by 90 degrees around its axis, and is arranged so that the end in the longitudinal direction of the cross section corresponds to the holding portion 10a of the hole mold portion 10. Then, by rotating both roll molds 11 and 12 in opposite directions, the cross-section longitudinal end L of the rough shaped material W ₁ is held and pressed by the holding parts 10a of both roll molds 11 and 12. It spreads in the lateral direction and is shaped so that its cross section is substantially land-shaped according to the shape of the hole mold part 10 of the roll molds 11 and 12. Since the cross-section longitudinal direction end portion L of the rough profile W ₁ is held by the holding portions 10a of the two roll dies 11, 12, the so-called sitting of the rough profile W ₁ is good particularly when initially pressed in the cross-section longitudinal direction. .

In rolled 11 in this embodiment of the present invention, since the cross-sectional longitudinal end L of Sokatachizai W ₁ is improved sit held by the holding portion 10a of the grooved portions 10, crude form by a pressing force Since the material W ₁ is less likely to buckle and the thickness T2 of the cross-sectional oval shape formed in the first pass can be reduced, the forming efficiency is high, and the rough shape material W ₁ does not escape due to the pressing force. The cross-sectional longitudinal end L of Sokatachizai W ₁ is to be initially pressed by the holding portion 10a formed to correspond to the shape of such a width T1, described in the prior art (FIG. 10) Like the roll dies 11 ′ and 12 ′ formed into a square cross section, there is no gap K between the longitudinal section end portion L of the rough shaped material W ₁ and the groove bottom 10 a ′ of the hole mold 10. , therefore, for the material of the portions corresponding to the holding portion 10a of Sokatachizai W ₁ flows in the axial direction by the pressing, as shown in the photograph in FIG. 5, closed end face W ₂ a of Sokatachizai W ₂ It was overhanged uniformly in the same manner as the other parts without causing any problems. As a result, the final rough shape W such as for manufacturing a steering knuckle as the product A by die-forging eliminates the occurrence of the ridge line J (FIG. 14) that causes the scratch J ′ (FIG. 15). It was.

Next, in the roll forging method of the present invention, a rough shape material W having a predetermined shape for manufacturing a steering knuckle by stamping forging using the roll dies 11 and 12 configured as described above is used in 4 passes. This will be described in detail depending on the case of molding by the above process.
The roll forging method of the present invention generally includes a step of forming a pre-rough shaped material W ₁ having an oval cross-section from an aluminum-based rod-shaped material W ₀ by roll forging (the first pass in this embodiment), and this pre-rough shape. a step of forming a rough profile W ₂ of cross land shape by pressing the cross-sectional longitudinal ends L by displacing the wood W ₁ (2 pass), by displacing the crude profile W ₂ cross Oval And a step (third pass) of forming the rough post-shaped material W ₃ after the shape.

In forming the rough profile W having a predetermined shape is subjected an aluminum-based stick-shaped material W ₀ in such stamping forging is first rod-shaped material W ₀ of a circular cross-section shape _(see (a) of FIG. 9) A process of holding the manipulator 13 at a predetermined temperature, such as heating, placing it at a predetermined position between the roll molds, rotating the roll molds in opposite directions, and passing the coarse shaped material W ₀ is performed (first pass). . Coarse profile W ₀ of a circular section shape are formed on both rolled grooved portion is pressed by ellipses (Oval) crude form of shaped material W _{1 (see} FIG. 9 (b)).

Then, Sokatachizai W _1, such as to for example 410-460 ° heats state, preferably by displacing 90 degrees in the axis around at 420 to 450 degrees in the state held by the manipulator 13, a roll-type 11 and 12 The roll molds 11 and 12 are rotated in opposite directions to pass through the coarse shaped material W ₁ (second pass). When the roll dies 11 and 12 are configured as shown in FIG. 1, the rough shaped member W ₁ is pressed without causing a gap at the end L in the longitudinal direction of the cross section against the bottom surface of the hole mold 10. Thus, the material flows so as to spread in the lateral direction, and then the material flows evenly in the axial direction, so that the rough shaped material W ₂ having a land shape in cross section corresponding to the shape of the hole 10 shown in FIG. It will be molded. When the roll dies 11 and 12 are configured as shown in FIG. 2, the cross-section longitudinal end L of the rough shaped material W ₁ forms a gap with respect to the holding portion 10 a of the hole mold 10. The material is pressed without being held and flows so that the material spreads in the lateral direction, and then the material flows evenly in the axial direction, corresponding to the shape of the hole mold portion 10 shown in FIG. However, the substantially land-shaped rough material W ₂ is formed. By the present invention for forming a coarse profile W ₂ in cross land shape by roll forging, because the material flow in the axial direction is uniform, the end faces W ₂ a of Sokatachizai W ₂ is uniformly overhangs.

Subsequently, held by the manipulator 13 in a state of a predetermined temperature such as heating the crude profile W ₂ formed into cross land shape, and disposed at a predetermined position between the rolled, rotated in the opposite direction to the roll-type from each other a step of passing the crude shaped product W ₂ Te (third pass). Coarse profile W ₂ of cross land shape is molded into being pressed sectional ellipses by grooved portions of the roll-type (oval) roughness profile of the shape W _{3 (see} FIG. 9 (d)). Since the rough shaped material W ₂ with the end face protruding uniformly is roll-forged in the third pass, the formed rough shaped material W ₃ is not attracted and the material flows evenly in the axial direction. Will be issued.

Then, hold the manipulator 13 in a state of a predetermined temperature such as heating the crude profile W ₃ formed into cross oval shape, and disposed at a predetermined position between the rolled, by rotating in the opposite direction to the roll-type from each other A step of passing the rough shaped material W ₃ is performed (fourth pass). Coarse profiles W ₃ cross-sectional oval shape is formed into the final Sokatachizai W circular section shape is pressed by the grooved portions of the roll-type (see (e) in FIG. 9). Since the rough shaped member W ₃ with the end face extending evenly is further roll-forged in the fourth pass, there is no ridge line J (see FIG. 13) due to shrinkage in the formed rough shaped member W, and the axial direction is further increased. The material will flow evenly and overhang. Therefore, even when the rough shaped material W is die-forged and a steering knuckle is formed as the product A as shown in FIG. 7, scratches J ′ (see FIG. 15) are generated in the steering knuckle. There is nothing to do.

  In addition, this invention is not limited to embodiment mentioned above, It is not limited to the case where it shape | molds by 4 passes. Furthermore, the present invention is also applicable to the case where the step of forming a cross-sectional land-shaped rough material by roll forging between the previous step and the subsequent step is not the second pass but the third pass or later. can do. In addition, the shape of the rough material W to be finally formed is not limited to a steering knuckle formed by stamping forging as a product, and is also applicable when a product of another shape is formed by other methods. can do.

It is sectional drawing which shows the principal part structure of one Embodiment of the roll type | mold which concerns on this invention, and the shape of the rough shaped material shape | molded by this roll type | mold. It is sectional drawing which shows the principal part structure of another embodiment of the roll type | mold which concerns on this invention. It is sectional drawing of the cross-section oval-shaped front rough shape shape | molded with the roll type | mold which concerns on this invention. It is sectional drawing of the rough shaped material shape | molded by the conventional roll type | mold by the cross-sectional square shape. It is a photograph which shows the end surface of the rough shaped material shape | molded by this invention. It is a front view of the rough shaped material finally shape | molded by this invention. It is a front view of the steering knuckle shown as an example of the product manufactured by the rough shape material shown in FIG. It is a schematic diagram which shows the general implementation condition of roll forging. It is a schematic diagram which shows the raw material shape change for every pass in roll forging. It is a schematic diagram which shows the state which performs the process of the 2nd pass by the conventional roll type | mold. It is a photograph which shows the edge part of the rough shape material which the process of the 2nd pass was performed with the conventional roll type | mold, and the shrinkage | contraction produced. It is a photograph which shows the edge part of the rough shape material which performed the process of the 3rd pass to the rough shape material shown in FIG. FIG. 13 is a photograph showing an end portion of a final rough shape member that has been subjected to a fourth pass step on the rough shape member shown in FIG. It is a front view which shows the final rough shape material in which the ridgeline shown in FIG. 13 was formed. FIG. 15 is a front view of a steering knuckle formed by stamping and forging using the final rough shape member on which the ridgeline shown in FIG. 14 is formed, and generating scratches.

Explanation of symbols

10 caliber portion, 10a: holding portion, 11, 12: roller type, W _0: rod-like material, W _1: Sokatachizai (front rough profile), W _2: Sokatachizai, W _3: Sokatachizai ( Post-rough profile), W: final profile

Claims (1)

A roll mold in the previous process for forming a pre-rough shaped material with an oval cross section from an aluminum rod-shaped material,
A roll mold of the step of forming the rough profile having a circular cross section by displacing the front rough profile and pressing the longitudinal end of the cross section;
A pre-rough shape in a group of roll molds, which includes a roll mold in a post-process for forming a post-rough shape member having a cross-sectional oval shape by displacing the rough shape member, and preforming the rod-shaped material into a predetermined shape A roll mold of a step of forming a rough cross-sectional material by pressing a cross-sectional longitudinal end of the material,
There is a hole mold part on the outer peripheral surface, and the hole mold part is pressed without causing a gap between the end part in the cross-sectional longitudinal direction of the oval-shaped pre-rough shape material, The material of the material is engraved so as to flow in the transverse direction in the cross section and in the axial direction of the rod-shaped material to form a rough shaped material with a circular cross section ,
The roll mold is recessed at the groove bottom of the hole mold portion with the same width as the width of the end portion in the longitudinal direction of the cross section of the previous rough shape formed in the previous step, and the front of the cross section oval shape is formed. A roll type characterized by having a holding part that holds and presses the end in the longitudinal direction of the cross-section without causing a gap between the end of the rough profile in the longitudinal direction of the cross-section .

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