Roll forging method and device

Abstract

Provided are a rolling forging method and device, which can improve the roundness of the final product shape and prevent the outer peripheral surfaces of the rollers from interfering with each other. The rolling forging device of the present invention is characterized in that the rolling forging device comprises: two edge rollers (1, 2), which abut against the inner diameter of an annular forging blank (c4) from both axial sides of the forging blank (c4) in an inclined state to apply axial pressing force; and two receiving rollers (3A, 3B), which are arranged opposite to each other on the outer peripheral side of the forging blank (c4) with a plane containing the axes of the two edge rollers (1, 2) as a boundary, and apply pressing force to the outer peripheral surface of the forging blank (c4).

Description

Technical Field

[0001] The invention relates to a rolling forging method and a device. Background Art

[0002] Conventionally, ring gears used in automobile differentials and the like are manufactured by roll forging. As a roll forging device used for such forging, a device (rolling machine) disclosed in Patent Document 1 (Japanese Patent No. 2507867) is known.

[0003] The rolling machine has two edge rollers that abut against the inner diameter of the annular blank from both sides of the axial direction in an inclined state to apply axial pressing force; and a receiving roller that applies pressing force to the outer peripheral surface of the forged blank. The two edge rollers and the receiving roller form a triangular closed area, and the closed area is used to close the rolling rolling to form the final product shape.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 2507867 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the conventional rolling machine, the inner and outer circumferences of the forged blank are free (unsupported) on both sides (upstream and downstream) of the triangular closed area, so there is a problem of poor roundness of the final product shape. In addition, when two edge rollers and one receiving roller approach each other on the outer circumference side of the triangular closed area, the outer circumferential surfaces of these rollers may interfere with each other. Therefore, there are restrictions on the final product shape that can be rolled forged.

[0009] Therefore, an object of the present invention is to provide a roll forging method and apparatus that can improve the roundness of the final product shape and prevent the outer peripheral surfaces of the rollers from interfering with each other.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the rolling forging method of the present invention is characterized in that the rolling forging method includes the following steps: a forging and stamping step to form a ring-shaped forging blank; and a rolling and rolling step to roll the forging blank into a final product shape using two edge rollers and two receiving rollers, the two edge rollers abutting the inner diameter of the forging blank from both axial sides of the forging blank in an inclined state to apply axial pressing pressure, the two receiving rollers are arranged opposite to each other on the outer peripheral side of the forging blank with a plane containing the axes of the two edge rollers as the boundary, and apply pressing pressure to the outer peripheral surface of the forging blank.

[0012] In addition, the rolling forging device of the present invention is characterized in that the rolling forging device comprises: two edge rollers, which abut against the inner diameter of the annular forging blank in an inclined state from both axial sides of the forging blank to apply axial pressing pressure; and two receiving rollers, which are arranged opposite to each other on the outer peripheral side of the forging blank with a plane containing the axes of the two edge rollers as the boundary, and apply pressing pressure to the outer peripheral surface of the forging blank.

[0013] Effects of the Invention

[0014] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1A This is a perspective view of the roll forging device of the present invention as viewed from obliquely above.

[0016] Figure 1B This is a perspective view of the roll forging device of the present invention as viewed obliquely from below.

[0017] Figure 2A It is a top view of the rolling forging device of the present invention.

[0018] Figure 2B It is a bottom view of the rolling forging device of the present invention.

[0019] Figure 3A It is a front view of the rolling forging device of the present invention.

[0020] Figure 3B It is a right side view of the rolling forging device of the present invention.

[0021] Figure 4 Yes Figure 2A A top view with the upper edge of the roller omitted.

[0022] Figure 5A It is a perspective view of the upper edge roller.

[0023] Figure 5B It is a perspective view of the lower edge roller.

[0024] Fig. 6A It is a cross-sectional view of a ring-shaped product example 1 produced by the roll forging method of the present invention.

[0025] Figure 6B It is a cross-sectional view of a ring-shaped product example 2 produced by the roll forging method of the present invention.

[0026] Figure 6C It is a cross-sectional view of a ring-shaped product example 3 produced by the roll forging method of the present invention.

[0027] Fig.6D It is a cross-sectional view of a ring-shaped product example 4 produced by the roll forging method of the present invention.

[0028] Figure 7 It is an explanatory diagram showing the steps of a conventional roll forging method.

[0029] Figure 8 This is an explanatory diagram of an apparatus used in a conventional roll forging method.

[0030] Fig. 9A This is a cross-sectional view of a forging blank used in a conventional roll forging method.

[0031] Fig. 9B This is a cross-sectional view of a roll forging device used in a conventional roll forging method.

[0032] Fig. 9C This is a top view of a roll forging device used in a conventional roll forging method.

[0033] Fig. 10A It is a side view of a conventional rolling forging device.

[0034] Fig. 10B It is a top view of an existing rolling forging device. DETAILED DESCRIPTION

[0035] ●Rolling forging method and device

[0036] Hereinafter, one embodiment of the roll forging method and apparatus of the present invention will be described with reference to the drawings. Figure 1A This is a three-dimensional view of the rolling forging device viewed from above. Figure 1B This is a perspective view of the device viewed from obliquely below.

[0037] The rolling forging device comprises an upper edge roller 1, a lower edge roller 2, and a pair of front and rear receiving rollers 3A and 3B. The upper edge roller 1 and the lower edge roller 2 press the inner diameter surface (inner peripheral surface) of the final product d, and the receiving rollers 3A and 3B press the outer diameter surface (outer peripheral surface) of the final product d.

[0038] The upper edge roller 1 and the lower edge roller 2 are connected to the rotation drive unit, such as Figure 1A In addition, the upper edge roller 1 and the lower edge roller 2 are configured to be able to rotate along the arrow direction. Figure 2A The plane P moves horizontally. The plane P is a plane containing the axes of the upper and lower edge rollers 1 and 2.

[0039] The axes of the upper edge roller 1 and the lower edge roller 2 are inclined at a predetermined angle relative to the rotation plane of the final product d. The inclination direction is radially outward of the final product d.

[0040] The predetermined inclination angle of the axis 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 of the upper edge roller 1 and the lower edge roller 2 can be substantially equal.

[0041] For example, the inclination angle of the upper edge roll 1 and the lower edge roll 2 can be set to about 60 degrees. However, the predetermined inclination angles of the upper edge roll 1 and the lower edge roll 2 may be different from each other depending on the inner diameter shape of the final product d.

[0042] The reason why the axes of the upper edge roller 1 and the lower edge roller 2 are tilted is to forge the inner diameter shape of the final product d by sharing the inner diameter shape of the final product d between the upper and lower edge rollers 1 and 2. By tilting the edge rollers 1 and 2, the inner diameter of the final product d can be pressed in both the axial direction and the radial direction. This can also cope with various and complex inner diameter shapes of the final product d.

[0043] The upper edge roll 1 and the lower edge roll 2 are shown in FIG. Figure 5A , Figure 5B .like Figure 5A As shown, the upper edge roller 1 is connected to the main cylindrical portion 1i and has four annular steps 1h, 1g, 1f, 1e. These four annular steps 1h, 1g, 1f, 1e are respectively connected to the four annular steps d8, d7, d6, d5 formed on the inner diameter of the final product d (see Figure 1A )correspond.

[0044] like Figure 5B As shown, the lower edge roller 2 has three annular steps 2g, 2f, and 2e. The three annular steps 2g, 2f, and 2e are respectively connected to the three annular steps d11, d10, and d9 formed on the inner diameter of the final product d (see Figure 1B , Figure 2B )correspond.

[0045] The front and rear anvil rollers 3A and 3B are arranged opposite to each other on the outer periphery of the final product d with the plane P including the axes of the upper and lower edge rollers 1 and 2 as the boundary. The height positions of the anvil rollers 3A and 3B are at the same height as the rotation surface (support surface) of the final product d.

[0046] The lower surface of the final product d is supported by a horizontal support plate. The support plate has a plurality of edges along which the front ends of the edge rollers 1 and 2 are supported. Figure 2A The plane P can be movably inserted into the long hole.

[0047] The plane P including the axes of the upper and lower edge rollers 1 and 2 is Figure 2A The axes 3Ac and 3Bc of the anvil rollers 3A and 3B are arranged at an equal distance E from the plane P.

[0048] By using two receiving rollers 3A and 3B in this way, the roundness of the final product d can be improved. Figure 2A , Figure 4 In the figure, the inner diameter of the final product d is pressed toward the right direction along the plane P by the upper and lower edge rollers 1 and 2 with an outward force vector F1. In contrast, the outer diameter of the final product d is pressed evenly from the upper and lower sides of the plane P by the two receiving rollers 3A and 3B toward the direction of the rotation center C with an inward force vector F2 and F2.

[0049] In addition, Figure 4 Omitted Figure 2A The upper edge of the roller. Figure 4 The curvature radius of the final product d is limited by balancing the three force vectors F1, F2, and F3, resulting in an improved roundness of the final product d.

[0050] The straight line connecting the rotation center C of the final product d and the axes 3Ac and 3Bc of the receiving rollers 3A and 3B forms an equal angle θ with respect to the plane P. The triangle (C, 3Ac, 3Bc) with the rotation center C as a vertex is an isosceles triangle.

[0051] The diameter and angle θ of the receiving rollers 3A and 3B can be freely changed according to the size (diameter) of the final product d. However, the diameters of the receiving rollers 3A and 3B must be the same, and the angles θ of the receiving rollers 3A and 3B relative to the plane P must also be the same. When this relationship is broken, the roundness of the final product d will be affected, resulting in product defects. Therefore, the "isosceles triangle" is necessary for product quality.

[0052] In the example shown in the figure, the angle θ is set to about 30 degrees, but it is not limited to this angle. In addition, in the example shown in the figure, the diameters of the receiving rollers 3A and 3B are slightly smaller than the diameter of the final product d, but it is not limited to such a size relationship.

[0053] An integral roller support shaft is fitted in the center holes 3Aa and 3Ba of the anvil rollers 3A and 3B in a cassette manner. The roller support shaft is rotatably supported by a bearing disposed on a common stand (fixed).

[0054] like Figure 3A As shown, the width (up and down width) of the outer peripheral surface of the receiving rollers 3A and 3B is slightly wider than the width (up and down width) of the outer peripheral surface of the final product d. Therefore, the entire outer peripheral surface of the final product d is reliably supported by the receiving rollers 3A and 3B.

[0055] The upper end edges of the anvil rollers 3A and 3B are formed into tapered surfaces 3Ai and 3Bi, and are configured to avoid interference with the main body cylindrical portion 1i of the upper edge roller 1 by the tapered surfaces 3Ai and 3Bi.

[0056] That is, even if the anvil rollers 3A and 3B are arranged close to each other or the upper and lower edge rollers 1 and 2 are brought close to the anvil rollers 3A and 3B, interference between the upper edge roller 1 and the anvil rollers 3A and 3B can be prevented.

[0057] However, the tapered surfaces 3Ai and 3Bi are not necessary to prevent interference between the upper edge roller 1 and the ancillary rollers 3A and 3B. In the present embodiment, two ancillary rollers 3A and 3B are provided, so interference between the rollers can be easily avoided by increasing the interval between the ancillary rollers 3A and 3B.

[0058] In the case of a single receiving roller as in the prior art, Fig. 9B , Fig. 9C As shown, the anvil roll 3 easily interferes with the upper and lower edge rolls 1 and 2. Therefore, the shapes of the edge rolls 1 and 2 and the anvil roll 3 are restricted, and further, the shape of the final product d that can be roll-forged is restricted.

[0059] By forming the receiving rollers by a pair of two receiving rollers 3A and 3B in the front and rear as in the present embodiment, it is possible to avoid interference between the upper and lower edge rollers 1 and 2 and the receiving rollers 3A and 3B. Therefore, the shapes of the edge rollers 1 and 2 and the receiving rollers 3A and 3B can be freely designed, and thus the shape of the final product d that can be roll-forged can also be freely designed.

[0060] ●Examples of final products with different shapes

[0061] Figure 6A to Figure 6D Examples of final products d having different shapes are shown. The shapes of the upper edge roller 1 and the lower edge roller 2 correspond to the shapes of the respective final products d. In any example, the outer peripheral surface of the final product d is pressed by the two receiving rollers 3A and 3B.

[0062] exist Fig. 6A , Figure 6B In the embodiment, the outer peripheral surfaces of the two receiving rollers 3A and 3B are simple cylindrical corresponding to the outer peripheral surface of the final product d. Figure 6C In the embodiment, the outer peripheral surfaces of the receiving rollers 3A and 3B are tapered surfaces (conical surfaces) corresponding to the outer peripheral surface of the final product d. Fig.6D In the embodiment, annular convex portions are formed on the outer peripheral surfaces of the receiving rollers 3A and 3B so as to correspond to the outer peripheral surface of the final product d.

[0063] ●Existing rolling forging methods and devices

[0064] The roll forging method and roll forging device of the present invention are basically the same as the existing roll forging method and device disclosed in Patent Document 1 (Japanese Patent No. 2507867), except that they are composed of two receiving rollers. Figure 7 to Figure 10B The conventional roll forging method and apparatus are described.

[0065] Figure 7 This is a process diagram illustrating a conventional roll forging method. In this process, first, the left end blank c1 is heated to a predetermined temperature (eg, 1250° C.) by an induction heating furnace. The heated blank c1 is upset into a disk-shaped blank c2 by an upset punch and a die.

[0066] Next, a punch and a die having a smaller diameter than the inner and outer diameters of the final product d are used to form a bottomed annular intermediate product blank c3 having a smaller diameter than the inner and outer diameters of the final product d and a thicker wall thickness in the axial direction than the wall thickness of the final product d. The center of the bottom of the blank c3 is punched out using a punching punch and a die to form a cross-sectional L-shaped annular forging blank c4 having a smaller diameter than the inner and outer diameters of the final product d and a thicker wall thickness in the axial direction than the wall thickness of the final product d.

[0067] The above is the forging and stamping process. Figure 8 The forging and pressing process is described in more detail in , firstly, the blank c1 is heated to a predetermined temperature by the induction heating furnace 4 , and the blank c1 is upset into a disk-shaped blank c2 by the upset punch 5 and the die 6 .

[0068] Next, a punch 7 and a die 8 having a diameter smaller than the inner and outer diameters of the final product d are used to form a bottomed annular intermediate product blank c3 having a diameter smaller than the inner and outer diameters of the final product d and a wall thickness in the axial direction thicker than the wall thickness in the axial direction of the final product d. The center of the bottom of the blank c3 is punched out by a punching punch 9 and a die 10 of a forging press 11 to form a forged blank c4 having a cross-section L-shaped annular shape having a diameter smaller than the inner and outer diameters of the final product d and a wall thickness in the axial direction thicker than the wall thickness in the axial direction of the final product d.

[0069] The forging press machine 11 is configured such that punches and dies are arranged at equal intervals and perform forming operations in a synchronized manner, and a forging object is sequentially supplied to processing positions of the punches and dies by a feeder (not shown).

[0070] The forging blank c4 with the bottom center blanked out is Figure 8 The rolling machine 12 at the right end performs rolling forging to form the final product shape. The rolling machine 12 comprises: two edge rollers 1, 2, which abut against the forging blank c4 from both ends in the axial direction to apply axial pressing force; and a receiving roller 3, which abuts against the outer peripheral surface of the forging blank c4 in a plane substantially the same as the plane where the two edge rollers 1, 2 apply pressing force to the forging blank c4 in the radial direction, thereby giving the outer peripheral surface shape of the final product d (two receiving rollers 3A, 3B in this embodiment).

[0071] like Fig. 9BAs shown, the two edge rollers 1 and 2 have the shape of the cross-section along the axial direction of the two axial end surfaces of the final product d. That is, the edge roller 1 on one side integrally has: a first molding surface 1a, which molds the web d1 of the final product d; a second molding surface 1b, which is continuous with the first molding surface 1a and molds the inner diameter tapered surface of the flange portion d2 of the final product d; and a third molding surface 1c, which is continuous with the second molding surface 1b and forms one axial end surface d3 of the final product d. The edge roller 2 on the other side also has substantially the same first molding surface 2a, second molding surface 2b and third molding surface 2c.

[0072] like Fig. 10A and Fig. 10B As shown, the two edge rollers 1 and 2 are arranged on the base 13 in a state of being tilted at a predetermined angle and facing each other up and down via support members 14 and 15, and are supported to be rotatable, and the upper edge roller 1 can be retracted upward. As described above, the receiving roller 3 can be fixedly mounted on a roller support shaft supported on a fixed stand, or can be supported in a rotatable manner on a slide table 17, which is arranged on the base 13 in a manner of sliding horizontally via a pressing unit 16. The receiving roller 3 causes a radial pressing force to act on the forged blank c4 during the roll rolling.

[0073] The plurality of guide rollers 18 are supported on the base 13 so as to be able to contact the outer peripheral surface of the forged blank c4 during the rolling process and to automatically move in the radial direction according to the diameter expansion of the forged blank c4 during the rolling process. Fig. 10B Among them, 19 is a carrying-in unit for the forging blank c4, and 20 is a carrying-out unit for the final product d.

[0074] When the forging punch machine 11 and the rolling machine 12 are constituted by a continuous production line, the forging blank c4 is slightly heated directly or in an induction heating furnace to a predetermined temperature (e.g., 950° C.) using the residual heat of the forging blank c4 after hot forging, and then provided between the two edge rollers 1 and 2 of the rolling machine 12. The forging blank c4 is pressed from both ends of the axial direction by the two edge rollers 1 and 2, and a receiving roller 3 is pressed against the outer peripheral surface of the forging blank c4 to apply a radial pressing force (in this embodiment, the pressing force is applied by the two receiving rollers 3A and 3B).

[0075] In this state, the forging billet c4 is rolled by the two edge rolls 1 and 2 and one anvil roll 3 while the anvil roll 3 rotates to contact the forging billet c4, thereby forming a final product d. The two edge rolls 1 and 2 may rotate actively in addition to being driven.

[0076] After rolling is completed, the rotation of the receiving roller 3 is stopped, and the receiving roller 3 is moved back in the radial direction, so that the upper edge roller 1 is moved back upward. Thus, the final product d after rolling is carried out by the carrying-out unit 20, and the next forging blank c4 is carried in by the carrying-in unit 19, and the above-mentioned operation is repeated.

[0077] 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 embodiments, both the upper edge roller 1 and the lower edge roller 2 have stepped shapes, but the stepped shapes depend on the shape of the final product d. Depending on the shape of the final product d, for example, only one of the upper edge roller 1 or the lower edge roller 2 may have a stepped shape, and the other may have a tapered shape.

[0078] Description of symbols

[0079] 1: upper edge roller; 1a: first molding surface; 1b: second molding surface; 1c: third molding surface; 1h, 1g, 1f, 1e: step portion; 1i: main cylindrical portion; 2: lower edge roller; 2a: first molding surface; 2b: second molding surface; 2c: third molding surface; 2g, 2f, 2e: step portion; 3A, 3B: receiving roller; 3Aa, 3Ba: center hole; 3Ac, 3Bc: axis; 3Ai, 3Bi: conical surface; 4: induction heating furnace; 5: upsetting punch; 6: die; 7: punch; 8: die; 9: blanking punch; 10: die; 11: Forging press; 12: Rolling press; 13: Base; 14, 15: Supporting parts; 16: Pressing unit; 17: Sliding table; 18: Guide roller; 19: Loading unit; 20: Loading unit; C: Rotation center; E: Equidistant; P: Plane; c1: Billet; c2: Billet; c3: Intermediate billet; c4: Forging billet; d: Final product; d1: Web; d11, d10: Step; d2: Flange; d3: Axial end face; d8, d7: Step; F1: Outward force vector; F2: Inward force vector; θ: Angle.

Claims

1. A rolling forging method, characterized in that: The rolling forging method comprises the following steps: A forging and stamping process to form a ring-shaped forging blank; and The rolling process uses two edge rollers and two receiving rollers to roll the final product shape from the forging blank. The two edge rollers can move in the radial direction of the forging blank, and abut against the inner diameter of the forging blank from both axial sides of the forging blank in an inclined state to apply axial pressing pressure. The two receiving rollers are arranged opposite to each other at fixed positions on the outer peripheral side of the forging blank with a plane containing the axes of the two edge rollers as the boundary, and apply pressing pressure to the outer peripheral surface of the forging blank when the two edge rollers move outward in the radial direction of the forging blank.

2. A rolling forging device, characterized in that: The rolling forging device has: Two edge rollers, which are movable in the radial direction of the annular forging blank and abut against the inner diameter of the forging blank from both axial sides of the forging blank in an inclined state to apply an axial pressing force; and Two receiving rollers are arranged opposite to each other at fixed positions on the outer peripheral side of the forging blank with a plane containing the axes of the two edge rollers as the boundary, and apply pressing force to the outer peripheral surface of the forging blank when the two edge rollers move outward in the radial direction of the forging blank.

3. The rolling forging device according to claim 2, characterized in that: The two ancillary rollers have the same outer diameter, and the axes of the two ancillary rollers are disposed at positions equidistant from a plane including the axes of the two edge rollers.

4. The rolling forging device according to claim 2 or 3, characterized in that: The two edge rollers are connected to a rotation drive source, and the forging blank is driven to rotate by the rotation of the two edge rollers, and the two receiving rollers are driven to rotate by the rotation of the forging blank.

5. The rolling forging device according to claim 2 or 3, characterized in that: The two receiving rollers are connected to a rotation driving source, and the forging blank is driven to rotate by the rotation of the two receiving rollers, and the two edge rollers are driven to rotate by the rotation of the forging blank.

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