CN118871226A

CN118871226A - Roll forging method and device

Info

Publication number: CN118871226A
Application number: CN202480001853.9A
Authority: CN
Inventors: 井上尚路
Original assignee: Kogaya Co ltd
Current assignee: Kogaya Co ltd
Priority date: 2023-09-25
Filing date: 2024-04-23
Publication date: 2024-10-29
Anticipated expiration: 2044-04-23
Also published as: CN118871226B

Abstract

Provided are a roll forging method and apparatus capable of improving the roundness of the shape of the final product without interference of the outer peripheral surfaces of rolls with each other. The roll forging apparatus of the present invention is characterized by comprising: two edge rollers (1, 2), wherein the two edge rollers (1, 2) are abutted against the inner diameter of the annular forging blank (c 4) from the two axial sides of the forging blank (c 4) in an inclined state to apply an axial pressing force; and two receiving rollers (3A, 3B), wherein the two receiving rollers (3A, 3B) are arranged opposite to each other on the outer peripheral side of the forged blank (c 4) with respect to a plane including the axes of the two edge rollers (1, 2) as a boundary, and apply a pressing force to the outer peripheral surface of the forged blank (c 4).

Description

Rolling forging method and apparatus

Technical Field

The invention relates to a roll forging method and apparatus.

Background

Conventionally, a ring gear used for a differential gear of an automobile or the like is manufactured by roll forging. As a roll forging apparatus used for forging, an apparatus (roll press) disclosed in patent document 1 (japanese patent No. 2507867) is known.

The roller press has: two edge rollers which are abutted against both sides of the annular blank in the axial direction in an inclined state to apply an axial pressing force to the inner diameter of the annular blank; and a receiving roller for applying a pressing force to the outer peripheral surface of the forged blank. A triangular closed region is formed by two edge rolls and a receiving roll, with which the final product shape is closed-rolled.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 2507867

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional roller press, the inner and outer circumferences of the forged blank are free (unsupported) on both circumferential sides (upstream side and downstream side) of the triangular closed region, and therefore there is a problem that the roundness of the final product shape is not good. In addition, when two edge rollers and one receiving roller approach each other on the outer peripheral side of the triangular closed area, there is a possibility that the outer peripheral surfaces of these rollers interfere with each other. Therefore, there is a limitation in the shape of the final product that can be roll forged.

Accordingly, an object of the present invention is to provide a roll forging method and apparatus capable of improving the roundness of the shape of the final product without interference of the outer peripheral surfaces of rolls with each other.

Means for solving the problems

In order to solve the above problems, a roll forging method according to the present invention includes: forging and stamping to form an annular forging blank; and a rolling step of rolling a final product shape from the forging blank by using two edge rollers that apply an axial pressing force to the inner diameter of the forging blank by abutting the two edge rollers in an inclined state from both axial sides of the forging blank, and two receiving rollers that are disposed opposite to each other on the outer peripheral side of the forging blank with respect to a plane including the axes of the two edge rollers as a boundary, and apply the pressing force to the outer peripheral surface of the forging blank.

In addition, the roll forging apparatus according to the present invention is characterized by comprising: two edge rollers for applying an axial pressing force to the inner diameter of the annular forged blank by abutting the two edge rollers in an inclined state from both axial sides of the forged blank; and two receiving rollers which are arranged opposite to each other on the outer peripheral side of the forged blank with respect to a plane including axes of the two edge rollers as a boundary, and which apply a pressing force to the outer peripheral surface of the forged blank.

Effects of the invention

According to the present invention, the roundness of the final product shape can be improved, and the outer peripheral surfaces of the rollers can be prevented from interfering with each other.

Drawings

FIG. 1A is a perspective view of the roll forging apparatus of the present invention as seen obliquely from above.

FIG. 1B is a perspective view of the roll forging apparatus of the present invention as seen obliquely from below.

Fig. 2A is a top view of the roll forging apparatus of the present invention.

Fig. 2B is a bottom view of the roll forging apparatus of the present invention.

Fig. 3A is a front view of the roll forging apparatus of the present invention.

FIG. 3B is a right side view of the roll forging apparatus of the present invention.

Fig. 4 is a plan view of the upper edge roll of fig. 2A omitted.

Fig. 5A is a perspective view of the upper side edge roller.

Fig. 5B is a perspective view of the lower edge roll.

Fig. 6A is a cross-sectional view of an annular product example 1 using the roll forging method of the present invention.

Fig. 6B is a cross-sectional view of an annular product example 2 using the roll forging method of the present invention.

Fig. 6C is a cross-sectional view of annular product example 3 using the roll forging method of the present invention.

Fig. 6D is a cross-sectional view of annular product example 4 using the roll forging method of the present invention.

Fig. 7 is an explanatory diagram showing a process of a conventional roll forging method.

Fig. 8 is an explanatory view of an apparatus used in a conventional roll forging method.

Fig. 9A is a cross-sectional view of a forged blank used in a conventional roll forging method.

Fig. 9B is a cross-sectional view of a roll forging apparatus used in a conventional roll forging method.

Fig. 9C is a top view of a roll forging apparatus used in a conventional roll forging method.

Fig. 10A is a side view of a conventional roll forging apparatus.

Fig. 10B is a top view of a conventional roll forging apparatus.

Detailed Description

● Rolling forging method and apparatus

Hereinafter, an embodiment of the roll forging method and apparatus of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of the roll forging apparatus as viewed from obliquely above, and fig. 1B is a perspective view of the apparatus as viewed from obliquely below.

The roll forging apparatus has an upper edge roll 1, a lower edge roll 2, and a pair of front and rear receiving rolls 3A, 3B. The inner diameter surface (inner peripheral surface) of the final product d is pressed by the upper edge roller 1 and the lower edge roller 2, and the outer diameter surface (outer peripheral surface) of the final product d is pressed by the receiving rollers 3A, 3B.

The upper edge roller 1 and the lower edge roller 2 are coupled to a rotation driving unit, and are driven to rotate in the arrow direction as shown in fig. 1A. In addition, the upper edge roller 1 and the lower edge roller 2 are configured to be horizontally movable along a plane P of fig. 2A. The plane P is a plane containing the axes of the upper and lower edge rollers 1, 2.

The axes of the upper edge roller 1 and the lower edge roller 2 are inclined at a prescribed angle with respect to the rotation plane of the final product d. The oblique direction is radially outward of the end product d.

The predetermined inclination angles of the axes of the upper edge roller 1 and the lower edge roller 2 can be set in accordance with the inner diameter shape of the final product d. The predetermined inclination angle can be substantially equal in the upper edge roller 1 and the lower edge roller 2.

For example, the inclination angle of the upper edge roller 1 and the lower edge roller 2 can be set to about 60 degrees. However, the predetermined inclination angles of the upper edge roller 1 and the lower edge roller 2 may be different from each other depending on the inner diameter shape of the final product d.

The axes of the upper edge roll 1 and the lower edge roll 2 are inclined so as to be formed by forging so that the inner diameter shape of the final product d is shared by the upper and lower edge rolls 1, 2. By tilting the edge rollers 1,2, the inner diameter of the final product d can be pressed in both the axial direction and the radial direction. This also makes it possible to cope with various and complicated inner diameter shapes of the final product d.

Fig. 5A and 5B show the individual bodies of the upper edge roller 1 and the lower edge roller 2. As shown in fig. 5A, the upper edge roller 1 has four annular stepped portions 1h, 1g, 1f, 1e connected to the main body cylindrical portion 1 i. The four annular stepped portions 1h, 1g, 1f, 1e correspond to the four annular stepped portions d8, d7, d6, d5 (see fig. 1A) formed on the inner diameter of the final product d, respectively.

As shown in fig. 5B, the lower edge roller 2 has three annular stepped portions 2g, 2f, 2e. These three annular stepped portions 2g, 2f, 2e correspond to three annular stepped portions d11, d10, d9 (see fig. 1B, 2B) formed on the inner diameter of the final product d, respectively.

The front and rear receiving rollers 3A and 3B are disposed opposite to each other on the outer peripheral side of the final product d, with respect to a plane P including the axes of the upper and lower edge rollers 1 and 2. The height position of the receiving rollers 3A, 3B is the same as the height of the rotation surface (bearing surface) of the final product d.

The lower surface of the end product d is supported by a horizontal support plate. The support plate has a long hole into which the tip ends of the edge rollers 1, 2 are inserted so as to be movable along the plane P of fig. 2A.

The plane P containing the axes of the upper and lower edge rollers 1, 2 is shown by a horizontal one-dot chain line in fig. 2A. The axes 3Ac, 3Bc of the receiving rollers 3A, 3B are arranged equidistantly E from the plane P.

By using the two receiving rollers 3A and 3B in this way, the roundness of the final product d can be improved. That is, in fig. 2A and 4, the inner diameter of the final product d is pressed by the upper and lower edge rollers 1 and 2 to the outward force vector F1 in the right direction along the plane P, whereas the outer diameter of the final product d is equally pressed by the two receiving rollers 3A and 3B from the upper and lower sides sandwiching the plane P to the direction of the rotation center C to the inward force vectors F2 and F2.

In addition, the upper edge roller of fig. 2A is omitted in fig. 4. The radius of curvature of the final product d is limited by the balance of the three force vectors F1, F2 of fig. 4, as a result of which the roundness of the final product d is improved.

The straight line connecting the rotation center C of the final product d and the axes 3Ac,3Bc of the receiving rollers 3A, 3B forms an equal angle θ with respect to the plane P. Triangles (C, 3ac,3 bc) with the rotation center C as vertices are isosceles triangles.

The diameters of the receiving rollers 3A and 3B and the magnitude of the angle θ can be freely changed according to the size (diameter) of the final product d. However, the diameter of the receiving rollers 3A, 3B must be the same, and the angle θ of the receiving rollers 3A, 3B with respect to the plane P must also be the same. If this relationship is broken, the roundness of the final product d is affected, and the product is defective. Therefore, the said "isosceles triangle" is necessary for the quality of the product.

In the example of the figure, the angle θ is set to about 30 degrees, but is of course not limited to this angle. In the illustrated example, the diameters of the receiving rollers 3A and 3B are slightly smaller than the diameter of the final product d, but the relationship is not limited to this.

An integral roller support shaft is fitted in a cassette manner in the center holes 3Aa, 3Ba of the receiving rollers 3A, 3B. The roller support shaft is rotatably supported by a bearing disposed on a common mount (fixed).

As shown in fig. 3A, the width (up-down width) of the outer peripheral surfaces of the receiving rollers 3A, 3B is slightly wider than the width (up-down width) of the outer peripheral surface of the final product d. Thus, the entire outer peripheral surface of the final product d is reliably supported by the receiving rollers 3A and 3B.

The upper edges of the receiving rollers 3A, 3B are formed as tapered surfaces 3Ai, 3Bi. The tapered surfaces 3Ai and 3Bi are configured to avoid interference with the main body cylindrical portion 1i of the upper edge roller 1.

That is, even if the receiving rollers 3A and 3B are disposed close to each other or the upper and lower edge rollers 1 and 2 are disposed close to the receiving rollers 3A and 3B, the interference between the upper edge roller 1 and the receiving rollers 3A and 3B can be prevented.

However, the tapered surfaces 3Ai, 3Bi are not necessary to prevent interference between the upper edge roller 1 and the receiving rollers 3A, 3B. In the present embodiment, since the two receiving rollers 3A and 3B are provided, interference between the rollers can be easily avoided by expanding the mutual interval between the receiving rollers 3A and 3B.

In the case of a single receiving roller as in the prior art, the receiving roller 3 is likely to interfere with the upper and lower edge rollers 1 and 2 as shown in fig. 9B and 9C. Therefore, the shapes of the edge rolls 1, 2 and the receiving roll 3 are restricted, and the shape of the final product d that can be roll forged is restricted.

By configuring the receiving rollers by the pair of front and rear receiving rollers 3A, 3B as in the present embodiment, interference between the upper and lower edge rollers 1, 2 and the receiving rollers 3A, 3B can be avoided. Therefore, the shape of the edge rolls 1, 2 and the receiving rolls 3A, 3B can be freely designed, and therefore, the shape of the final product d that can be roll-forged can also be freely designed.

● Examples of differently shaped end products d

Fig. 6A to 6D show examples of the final products D having different shapes. The shape of the upper edge roll 1 and the lower edge roll 2 corresponds to the shape of each end product d. In any case, the outer peripheral surface of the final product d is pressed by the two receiving rollers 3A, 3B.

In fig. 6A and 6B, the outer peripheral surfaces of the two receiving rollers 3A and 3B correspond to the outer peripheral surface of the final product d, and in fig. 6C, the outer peripheral surfaces of the receiving rollers 3A and 3B correspond to the outer peripheral surface of the final product d, and are tapered surfaces (conical surfaces). In fig. 6D, annular protruding portions are formed on the outer peripheral surfaces of the receiving rollers 3A and 3B corresponding to the outer peripheral surface of the final product D.

● Existing roll forging method and apparatus

The roll forging method and the roll forging apparatus of the present invention are basically the same as those of the conventional roll forging method and apparatus disclosed in patent document 1 (japanese patent No. 2507867), except that they are composed of two receiving rolls. Accordingly, a conventional roll forging method and apparatus will be described below with reference to fig. 7 to 10B.

Fig. 7 is a process diagram illustrating a conventional roll forging method. In this step, the left end billet c1 is first heated to a predetermined temperature (e.g., 1250 ℃) by an induction heating furnace. The heated blank material c1 is upset into a disc-shaped blank material c2 by an upsetting punch and a die.

Next, a blank member c3 of a bottomed annular shape having a diameter smaller than the inner and outer diameter dimensions of the final product d and a wall thickness in the axial direction thicker than the axial wall thickness of the final product d is formed by a punch and a die having a diameter smaller than the inner and outer diameter dimensions of the final product d. The bottom center of the blank member c3 is blanked by a blanking punch and a die, and a cross-sectional L-shaped annular forged blank member c4 having a smaller diameter than the inner and outer diameter dimensions of the final product d and a thicker wall thickness in the axial direction than the axial wall thickness of the final product d is formed.

The above is the forging and pressing process. In fig. 8, the forging press step is further described in detail, in which the blank c1 is first heated to a predetermined temperature by an induction heating furnace 4, and the blank c1 is upset into a disc-shaped blank c2 by an upsetting punch 5 and a die 6.

Next, a blank member c3 of a bottomed annular shape having a diameter smaller than the inner and outer diameter dimensions of the final product d and an axial wall thickness thicker than the axial wall thickness of the final product d is formed by a punch 7 and a die 8 having diameters smaller than the inner and outer diameter dimensions of the final product d. The bottom center of the blank member c3 is punched by a punching punch 9 of a forging press 11 and a die 10 to form a cross-sectional L-shaped annular forged blank member c4 having a smaller diameter than the inner and outer diameter dimensions of the final product d and a thicker axial wall thickness than the axial wall thickness of the final product d.

The forging press 11 is configured to perform the forming operation while arranging the punches and dies at equal intervals, and to sequentially supply forging objects to the processing positions of the punches and dies by a feeder (not shown).

The forged blank c4 having the bottom center blanked is roll-forged by the roll press 12 at the right end of fig. 8 to be a final product shape. The roller press 12 has: two edge rollers 1,2, wherein the two edge rollers 1,2 are abutted against the forging blank c4 from the axial both ends to apply an axial pressing force; and one receiving roller 3 that contacts the outer peripheral surface of the forging blank c4 in a plane substantially identical to the pressing force application plane of the two edge rollers 1,2 to the forging blank c4 and applies a pressing force inward in the radial direction, thereby giving the outer peripheral surface shape of the final product d (in the present embodiment, the two receiving rollers 3A, 3B).

As shown in fig. 9, the two edge rollers 1,2 have cut surfaces along the axial direction in both end surfaces of the end product d in the axial direction. That is, the edge roller 1 integrally includes: a first molding surface 1a that molds a web d1 of the final product d; a second molding surface 1b that is continuous with the first molding surface 1a and forms an inner diameter tapered surface of the flange portion d2 of the final product d; and a third molding surface 1c that is continuous with the second molding surface 1b and forms one axial end surface d3 of the final product d. The other edge roll 2 also has substantially the same first molding surface 2a, second molding surface 2b, and third molding surface 2c.

As shown in fig. 10A and 10B, these two edge rollers 1 and 2 are provided on the base 13 via support members 14 and 15 so as to be inclined at a predetermined angle and face each other vertically, and are rotatably supported, so that the upper edge roller 1 can retract upward. As described above, the receiving roller 3 may be fixed in position and mounted on a roller support shaft supported by a fixed mount, or may be rotatably supported by a slide table 17, and the slide table 17 may be provided on the base 13 so as to slide horizontally via the pressing unit 16. The radial pressing force is applied to the forged blank c4 during the rolling by the receiving roller 3.

The plurality of guide rollers 18 can be brought into contact with the outer peripheral surface of the forging blank c4 during rolling and supported by the base 13 so as to be automatically moved in the radial direction according to the expansion of the forging blank c4 during rolling. In fig. 10B, 19 is a carry-in unit of the forging blank c4, and 20 is a carry-out unit of the final product d.

In the case where the forging press 11 and the roller press 12 are formed by a continuous line, the forging blank c4 is slightly heated to a predetermined temperature (for example, 950 ℃) directly or in an induction heating furnace by using the waste heat of the forging blank c4 after hot forging, and then is supplied between the two edge rollers 1 and 2 of the roller press 12. The forged blank c4 is pressed by the two edge rollers 1 and 2 from both axial ends, and one receiving roller 3 is pressed against the outer peripheral surface of the forged blank c4 to apply a pressing force in the radial direction (in the present embodiment, the pressing force is applied by the two receiving rollers 3A and 3B).

In this state, the forged blank c4 is closed-rolled by the two edge rolls 1 and 2 and the one receiving roll 3 while the receiving roll 3 is rotated to rotate the forged blank c4 in contact therewith, thereby forming the final product d. The two edge rollers 1, 2 can also be positively rotated in addition to the driven rotation.

After the completion of the rolling, the rotation of the receiving roller 3 is stopped, and the receiving roller 3 is retracted in the radial direction, and the upper edge roller 1 is retracted upward. As a result, the rolled final product d is carried out by the carrying-out unit 20, and the next forged blank c4 is carried in by the carrying-in unit 19, and the above-described operations are repeated.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments and various modifications are possible. For example, in the above embodiment, both the upper edge roller 1 and the lower edge roller 2 have a stepped shape, but the stepped shape depends on the shape of the final product d, and depending on the shape of the final product d, for example, only one of the upper edge roller 1 and the lower edge roller 2 may have a stepped shape and the other may have a tapered shape.

Description of the reference numerals

1: An upper edge roll; 1a: a first molding surface; 1b: a second molding surface; 1c: a third molding surface; 1h, 1g, 1f, 1e: a step portion; 1i: a main body cylindrical portion; 2: a lower edge roll; 2a: a first molding surface; 2b: a second molding surface; 2c: a third molding surface; 2g, 2f, 2e: a step portion; 3A, 3B: a receiving roller; 3Aa, 3Ba: a central bore; 3Ac, 3Bc: an axis; 3Ai, 3Bi: a conical surface; 4: an induction heating furnace; 5: upsetting a punch; 6: a mold; 7: a punch; 8: a mold; 9: punching a punch; 10: a mold; 11: forging a punching machine; 12: a roller press; 13: a base station; 14. 15: a support member; 16: a pressing unit; 17: a sliding table; 18: a guide roller; 19: a carry-in unit; 20: a carry-out unit; c: a rotation center; e: equidistant; p: a plane; c1: blank material; c2: a blank; c3: a blank of intermediate product; c4: forging a blank; d: a final product; d1: a web; d11, d10: a step portion; d2: a flange portion; d3: an axial end face; d8, d7: a step portion; f1: an outward force vector; f2: an inward force vector; θ: angle.

Claims

1. A roll forging method is characterized in that,

The rolling forging method comprises the following steps:

Forging and stamping to form an annular forging blank; and

And a rolling step of rolling a final product shape from the forging blank by using two edge rollers movable in a radial direction of the forging blank, the two edge rollers being capable of applying an axial pressing force to the inner diameter of the forging blank by abutting the two edge rollers in an inclined state from both axial sides of the forging blank, and two receiving rollers being disposed so as to face each other at a fixed position on the outer peripheral side of the forging blank with respect to a plane including axes of the two edge rollers as a boundary, and applying the pressing force to the outer peripheral surface of the forging blank when the two edge rollers are moved outward in the radial direction of the forging blank.

2. A roll forging device is characterized in that,

The roll forging device has:

Two edge rollers movable in a radial direction of an annular forged blank, the two edge rollers being abutted against each other in an inclined state from both axial sides of the forged blank with respect to an inner diameter of the forged blank to apply an axial pressing force; and

And two receiving rollers which are arranged opposite to each other at a fixed position on the outer peripheral side of the forging blank with respect to a plane including axes of the two edge rollers as a boundary, and which apply a pressing force to the outer peripheral surface of the forging blank when the two edge rollers move radially outward of the forging blank.

3. The roll forging apparatus as recited in claim 2, wherein,

The two receiving rollers have the same outer diameter, and the axes of the two receiving rollers are arranged at equidistant positions from a plane containing the axes of the two edge rollers.

4. A roll forging apparatus as recited in claim 2 or 3, wherein,

The two edge rollers are connected to a rotation driving source, the forged blank is driven to rotate by rotation of the two edge rollers, and the two receiving rollers are driven to rotate by rotation of the forged blank.

5. A roll forging apparatus as recited in claim 2 or 3, wherein,

The two receiving rollers are connected to a rotation driving source, the forged blank is driven to rotate by rotation of the two receiving rollers, and the two edge rollers are driven to rotate by rotation of the forged blank.