JP2008173661A - Die device for manufacturing hub ring, and method for manufacturing hub ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die device for manufacturing a hub ring and a method for manufacturing the hub ring, by which die device and method, a large number of products can be forged by one die, and the deformation of a flange can be prevented when knocking-out the product after forging without projecting the outside diameter of the flange in the direction of the outside diameter because of the wear of the die due to forging. <P>SOLUTION: The die device for manufacturing the hub ring comprises a die set having a first die 1 and a second die 2, and forges the hub ring 4 in the closed state that the first die 1 has been fitted into the bore portion 14 of the second die 2. A cavity 11 for forging a flange is formed by the cavity corresponding surface 16 of the first die 1 and the inside diameter surface and the stepped surface 27 in the bore portion 14 of the second die 2 in the closed state of the die set. The inside diameter surface of the cavity 11 for forging the flange is provided with a tapered surface 7a which reduces its diameter in the direction opposed to the pressing direction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  As shown in FIG. 7, some wheel bearing devices include a hub wheel 102 having a flange 114 extending in the outer diameter direction, and a bearing structure portion that is fitted onto the hub wheel 102.

  The hub wheel 102 includes a shaft portion 113 and the flange 114 projecting from the shaft portion 113. A mounting hole 123 is provided in the flange 114 along the circumferential direction, and a hub bolt 133 is mounted in the mounting hole 123. That is, the brake rotor and the wheel are overlapped with the end surface of the flange 114 and fixed by the hub bolt 133.

  In recent years, from the viewpoint of resource saving and low pollution, a reduction in vehicle weight has been strongly demanded in order to improve the fuel efficiency of automobiles. In automobile parts, the wheel bearing device is required to reduce the vehicle weight from the standpoints of improving the riding comfort by reducing the unsprung weight and improving the running stability by improving the ground contact property of the tire. Here, the unsprung weight refers to the weight of parts below the spring, such as tires, wheels, axles, and brake parts.

  In addition, when manufacturing a product (for example, a hub wheel), reducing the weight (material loss) that is removed by cutting or the like during processing in the middle is also used up (used efficiently). It is also desired from the viewpoint of cost reduction.

  Conventionally, when a machine part (hub wheel) having a flange is formed by forging, a billet (forging material) S1 as shown in FIG. 8A is placed as shown in FIG. After forming into the shape of S3 by performing the roughing as shown in (c), so-called deburring forging is performed by the forging die device, and the finishing is performed as shown in (d). To form the shape of S4. Here, the upsetting is intended to form an enlarged diameter portion at a predetermined portion of the material by pressing the material in the axial direction. Further, in this case, in the case of roughing, the product is a hub wheel and can be put into a mold apparatus (a large diameter portion 140 and a small diameter portion 141, and a tapered portion 142 that connects the large diameter portion 140 and the small diameter portion 141). Columnar shape of the shape consisting of

  In S4 formed as shown in FIG. 8D, the outer diameter burr 130 is formed at the tip of the flange 114. Therefore, the outer diameter burr 130 is trimmed as shown in FIG. I will finish it. After the hub wheel 102 having the flange 114 and the shaft portion 113 is molded, the hub bolt seat surface 132 is turned so that the flange surface 131 and the hub bolt seat surface 132 are parallel to each other as shown in FIG. In addition, the virtual line of FIG. 10 has shown the flange before turning.

  However, in the above-described deburring and forging, since the outer diameter burr 130 is cut by trimming, the cut portion is a material loss. Therefore, it is known that a processing method using hermetic forging as shown in FIG. 9 is effective as a means for reducing the material loss (Patent Document 1). For closed forging, a closed forging die apparatus as shown in FIG. 11 is used. In this case, similarly to the deburring and forging shown in FIG. 8, first, the billet S1 (forging material) as shown in FIG. 9 (a) is set up as shown in FIG. 9 (b) and formed into the shape of S2. Then, as shown in (c), roughing is performed to form the shape of S3. Then, finish punching as shown in (d) is performed using a closed forging die apparatus as shown in FIG.

As shown in FIG. 11, the closed forging die apparatus has a first die (upper die) 110 and a second die (lower die) 111 that fits into the upper die 110. A knockout pin 117 is inserted into the hole of the lower mold 111. That is, the first mold 110, the second mold 111, and the knockout pin 117 form a space for molding the hub wheel 102. Then, using a mold in which the first mold 110 and the second mold 111 are combined, the material in the molding hole of the second mold 111 is pressed by the first mold 110 and the second mold 111.
2004-034058

  The above-described processing method by hermetic forging eliminates the need for trimming the outer diameter burr 130, so that material loss can be suppressed and processing time and cost can be reduced. In some cases, the mold life becomes short and the mold life becomes short. That is, when the hub wheel 102 of the hub bearing is hermetically forged, as shown in FIGS. 12 and 13, the flange outer diameter corresponding portion 112 of the second die 111 is worn as the number of forgings increases. Due to this wear, as shown in FIG. 13, the flange outer diameter 119 of the product (hub wheel) increases on the drum (projects in the outer diameter direction). For this reason, when knocking out a product that has been forged in the final forging process from the mold with the knockout pin 117, the hub flange outer diameter 119 gets caught on the mold wear part (flange outer diameter corresponding part 112), and the normal product. (As shown in FIG. 14A, the flange 114 extends in a direction orthogonal to the hub wheel 102 axis) As shown in FIG. 14B, the flange 114 warps. Occurred. If warpage occurs in this way, a process such as coining the flange 114 later is required to correct the warpage of the flange 114. Further, when coining is not performed, due to the warp of the flange 114, an extra turning allowance for the flange surface 131 is required as compared with the case where there is no warp, and there is a problem that the effect of reducing material loss by closed forging is lost.

  Further, as one method for reducing the material loss, there is an omission of turning of the hub bolt seat surface 132. However, if the turning process of the hub bolt seat surface 132 is omitted, the step of making the hub bolt seat surface 132 and the flange surface 131 parallel to each other is omitted, so that the hub bolt seat surface 132 is affected by forging accuracy. When the hub bolt seat surface 132 is inclined with respect to the flange surface 131, the following problem occurs. (A) The head of the bolt may not be in close contact with the hub bolt seating surface 132, and the bolt head may be damaged when the nut is tightened by receiving the load (axial force) of the wheel nut tightening with only a part of the head. (B) Possibility of slanting when the bolt is driven (C) Possibility that the head of the bolt that is grounded only partially wears due to repeated driving load, and the nut is loosened due to a decrease in axial force, which may lead to the wheel falling off. Etc.

  In view of the above problems, the present invention can forge a large number of pieces with one mold without the flange outer diameter protruding in the outer diameter direction due to wear of the mold by forging. Provided is a hub wheel manufacturing mold apparatus and a hub wheel manufacturing method capable of preventing a flange from being deformed at the time of knockout.

  A hub apparatus for manufacturing a hub wheel according to the present invention includes a mold having a first mold and a second mold, and a hub forging the hub ring in a closed state in which the first mold is fitted into a hole of the second mold. In the wheel manufacturing mold apparatus, when the mold is closed, a flange forging cavity is formed by the cavity corresponding surface of the first mold and the inner diameter surface and the stepped surface of the hole of the second mold. A tapered surface that is reduced in diameter toward the counter-extrusion direction side is provided on the inner diameter surface of the cavity.

  In the hub wheel manufacturing mold of the present invention, the number of forgings is increased because a tapered surface that is reduced in the diameter toward the non-extrusion direction is formed on the inner diameter surface of the flange forging cavity formed in the mold closed state. Thus, even if the inner diameter surface of the flange forging cavity is worn, it is possible to prevent the outer diameter surface of the flange of the forged hub wheel from becoming larger than the inner diameter surface of the flange forging cavity.

  The tapered surface is provided on the anti-extrusion direction side of the inner diameter surface of the flange forging cavity, and a flat surface parallel to the axial direction is provided continuously from the tapered surface on the extrusion direction side of the inner diameter surface of the flange forging cavity. Can do. Thereby, the flange which has a plane and a taper surface on an outer diameter surface can be formed.

  The flange forging flange may have a petal shape in which protruding portions protruding in the outer diameter direction are arranged at a predetermined pitch along the circumferential direction. Thereby, the petal-shaped flange which arrange | positioned the protrusion part which protrudes in an outer diameter direction with the predetermined pitch along the circumferential direction can be formed.

  The flange forging flange can increase the axial clearance dimension of the space for forging the hub bolt seat surface forming portion, and can decrease the axial clearance dimension of other portions. Thereby, the hub bolt seat surface forming portion becomes a thick rib, and a flange that becomes a thin portion can be formed between the bolt seat surface forming portions.

  A hub wheel manufacturing method for forming a hub ring using the hub ring manufacturing die according to any one of claims 1 to 4, wherein the hub bolt seat surface is maintained in a non-turned forged skin finish. it can. That is, turning of the hub bolt seat surface after forging can be omitted.

  The hub wheel manufacturing die of the present invention can prevent the outer surface of the flange of the hub wheel to be forged from becoming larger than the inner surface of the cavity for flange forging even when the number of forgings is increased. It is possible to prevent the flange from being caught on the mold at the time of knockout. As a result, a larger number of pieces can be forged with a single die, and the die cost per product can be reduced, and a reduction in production cost can be expected. In addition, since the flange does not catch on the mold at the time of knockout after hammering, warping of the flange can be prevented. Thereby, the parallelism with the flange surface of a hub bolt seat surface improves, and even if a hub bolt seat surface remains forged, the whole bolt head will stick to a hub bolt seat surface. For this reason, it is possible to prevent the head of the bolt from being damaged when the nut is tightened, the possibility of being slanted when the bolt is driven, and the nut from being loosened to cause the wheel to fall off. Furthermore, the machining allowance of the flange surface can be reduced, and material loss can be reduced.

  Forming a flange having a flat surface and a tapered surface on the outer diameter surface by forming a plane parallel to the axial direction continuously from the tapered surface on the extrusion direction side of the outer diameter surface of the flange forging cavity. it can. Thereby, the rigidity of a flange is securable. In addition, since the plane provided in the flange forging flange is short, a large force is not applied during knockout after forging.

  Since it is possible to form a hub ring having a petal-shaped flange, or to form a hub ring having a flange where only the hub bolt seating surface is thick, it is possible to reduce the weight of the hub ring, Material costs can be reduced.

  Since the hub bolt seating surface can be maintained with a non-turned forged skin finish, turning of the hub bolt seating surface can be omitted, and the number of processing steps can be reduced and the processing cost can be reduced. be able to.

  Embodiments of a hub wheel manufacturing die and a hub wheel manufacturing method according to the present invention will be described with reference to FIGS.

  The hub wheel manufacturing mold of the present invention forms a hub wheel 4 of a wheel bearing device as shown in FIG. The wheel bearing device includes a hub wheel 4 having a flange 6 and a bearing structure part fitted on the hub wheel 4.

  The bearing structure includes an inner member (inner ring) 32 that is externally fitted and fixed to the hub wheel 4, an outer member (outer ring) 31 that is disposed around the hub wheel 4 and the inner ring 32, and the outer ring 31 and the hub. A rolling element (ball) 30 a interposed between the ring 4 and a rolling element (ball) 30 b interposed between the outer ring 31 and the inner ring 32 is provided.

  The hub wheel 4 includes a shaft portion 5 and the flange 6 protruding from the shaft portion 5. As shown in FIG. 5, a mounting hole 22 is provided in the flange 6 along the circumferential direction, and a hub bolt 23 is mounted in the mounting hole 22. That is, the brake rotor and the wheel are superimposed on the flange surface 20 of the flange 6 and fixed by the hub bolt 23.

  As shown in FIG. 1, the hub wheel manufacturing mold includes a first mold (upper mold) 1 and a second mold (lower mold) 2 that fits into the upper mold. A knockout pin 3 is inserted into the hole 12 of the lower mold 2. That is, the first mold 1, the second mold 2, and the knockout pin 3 form a space 26 for molding the hub wheel 4.

  The upper mold 1 has a short cylindrical shape, and a convex portion 9 is provided at the center of the lower surface thereof, and a concave groove 10 is formed on the outer periphery of the convex portion 9.

  The lower mold 2 has a through hole 29 penetrating in the vertical direction at the center. The through hole 29 includes an upper hole 14, an intermediate hole 13, and a lower hole 12. The upper hole 14 includes a large-diameter hole portion 8 and a tapered hole portion 7. The tapered hole portion 7 is reduced in diameter toward the non-extrusion direction side. The intermediate hole portion 13 includes a large diameter hole portion 17, a medium diameter hole portion 18, and a small diameter hole portion 19, and the lower hole 12 includes a small diameter hole portion 24 having a smaller diameter than the small diameter hole portion 19 of the intermediate hole 13.

  The first mold 1 is fitted into the large-diameter hole portion 8 of the through-hole 29, and the knockout pin 3 is inserted into the small-diameter hole portion 24 of the through-hole 29, so that a space 26 for molding the hub wheel 4 is formed. . That is, the flange forging cavity 11 is formed by the cavity corresponding surface 16 of the upper die 1 and the inner diameter surface and the stepped surface 27 of the hole 14 of the lower die 2. For this reason, the flange forging cavity 11 is formed with a taper surface 7a having a diameter reduced toward the counter-extrusion direction side on the inner diameter surface, and the axial direction continuously from the taper surface 7a on the extrusion direction side. Parallel planes 8a are formed. Note that the inclination α (see FIG. 2) of the tapered surface 7a is 10 ° or more and 30 ° or less. The concave groove 10 of the upper mold 1 serves as a hole for forming a pilot portion 15 of the hub wheel 4 as shown in FIG. The intermediate hole 13 of the lower mold 2 is formed with a shaft forging cavity 28 for forming the shaft portion 5 of the hub wheel 4.

  Next, a method for using the manufacturing mold apparatus of the embodiment will be described. First, the billet (forging material) heated as shown in FIG. 9 (a) is placed as shown in FIG. 9 (b) and subjected to roughing as shown in FIG. 9 (c). Then, when performing the finishing shot as shown in (d), the hub wheel 4 is molded using a mold as shown in FIG. That is, when the first mold 1 and the second mold 2 are in an open state, the forging material is put into the second mold. Then, the first die 1 is lowered toward the second die 2 by a press machine (not shown) and both are closed, and the forging material is pressed between the first die 1 and the second die 2. As a result, the hub wheel 4 having a predetermined shape having the shaft portion 5 and the flange 6 having a contour corresponding to the molding surfaces of the first die 1 and the second die 2 is formed. Thereafter, the product (hub wheel 4) is pushed out in the direction of arrow A (see FIG. 1) with the knockout pin 3 and taken out from the mold.

  Thereafter, as shown in FIG. 4, the flange surface 20 is turned to make the flange surface 20 and the hub bolt seat surface 21 parallel to each other. Thereby, the hub bolt seating surface 21 can omit turning. In addition, the virtual line of FIG. 4 has shown the shape of the flange 6 before turning.

  In the present invention, since the tapered surface 7a which is reduced in diameter toward the counter-extrusion direction is formed on the inner diameter surface of the flange forging cavity 11 formed in the mold closed state, the flange forging cavity is increased by increasing the number of forgings. Even if the inner diameter surface of 11 is worn, the outer diameter of the flange 6 of the forged hub wheel 4 can be prevented from becoming larger than the inner diameter surface of the flange forging cavity 11. As a result, a larger number of pieces can be forged with a single die, and the die cost per product can be reduced, and a reduction in production cost can be expected.

  Moreover, since the flange 6 does not catch on a metal mold | die at the time of knockout after hammering, the curvature of the flange 6 can be prevented. Thereby, the parallelism with the flange surface 20 of the hub bolt seat surface 21 is improved, and the entire bolt head is in close contact with the hub bolt seat surface 21 even if the hub bolt seat surface 21 remains forged. For this reason, it is possible to prevent the head of the bolt from being damaged when the nut is tightened, the possibility of being slanted when the bolt is driven, and the nut from being loosened to cause the wheel to fall off. Furthermore, the machining allowance of the flange surface 20 can be reduced and material loss can be reduced. The inclination α of the tapered surface 7a is preferably 10 ° or more and 30 ° or less. If the angle is less than 10 °, the flange 6 after forging protrudes due to wear of the inner surface of the flange 11 for forging the flange of the second die 2, and if the angle exceeds 30 °, the tip of the flange 6 becomes sharp and the rigidity of the flange 6 is increased. It cannot be secured.

  The taper surface 7a is provided on the anti-extrusion direction side of the inner diameter surface of the flange forging cavity 11, and is continuously parallel to the axial direction from the taper surface 7a on the extrusion direction side of the inner diameter surface of the flange forging cavity 11. A plane 8a can be provided. Thereby, the flange 6 which has a flat surface and a taper surface in an outer-diameter surface can be formed, and the rigidity of the flange 6 can be ensured. Since the axial length β of the flat surface 8a provided in the flange forging cavity 11 is short, a large force is not applied during knockout after forging. β is preferably 2 mm or more and 5 mm or less. If it exceeds 5 mm, a large force is applied at the time of knockout after forging, and if it is less than 2 mm, the rigidity of the flange 6 cannot be ensured.

  By the way, the flange 11 for flange forging can be formed into a petal shape in which protruding portions protruding in the outer diameter direction are arranged at a predetermined pitch along the circumferential direction. Accordingly, as shown in FIG. 6, the projecting portions 25 projecting in the outer diameter direction (that is, the hub bolt seat surface forming portion on which the hub bolt seat surface 21 is formed) are arranged at a predetermined pitch along the circumferential direction. A hub wheel 4 having a shaped flange 6 can be formed. For this reason, the hub wheel 4 can be reduced in weight and the material cost can be reduced.

  In addition, the flange forging cavity 11 can increase the axial clearance dimension of the space for forging the hub bolt seat surface forming portion 25 and reduce the axial clearance dimension of other portions. As a result, the hub bolt seat surface forming portion 25 (the portion where the hub bolt seat surface 21 is formed) becomes a thick rib, and the hub wheel 4 having the thin flange 6 is formed between the hub bolt seat surface forming portions 25. be able to. For this reason, the hub wheel 4 can be reduced in weight and the material cost can be reduced.

  Using the hub wheel manufacturing die, the hub bolt seating surface 21 can be maintained in a non-turned forged surface finish. Thereby, the turning process of the hub bolt seating surface 21 can be omitted, the number of processing steps can be reduced, and the processing cost can be reduced.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the flange outer diameter surface may be turned on the entire surface. , Only a part or the whole surface may not be turned.

It is sectional drawing of the metal mold | die for hub ring manufacture which shows embodiment of this invention. It is a principal part expanded sectional view of the metal mold | die for hub ring manufacture of the said FIG. It is sectional drawing of the wheel bearing apparatus using the hub ring manufactured using the metal mold | die for hub ring manufacture of the said FIG. It is a principal part expanded sectional view of the hub ring manufactured using the metal mold | die for hub ring manufacture of the said FIG. It is a front view of the hub wheel. It is a front view of the other hub ring manufactured using the metal mold | die for hub ring manufacture of the said FIG. It is sectional drawing of the conventional wheel bearing apparatus. It is process drawing of the conventional hub ring manufacture. It is process drawing of other conventional hub wheel manufacture. It is a principal part expanded sectional view of the conventional hub ring. It is sectional drawing of the conventional metal mold | die for hub ring manufacture. It is a principal part expanded sectional view of the metal mold | die for hub ring manufacture of the said FIG. FIG. 11 is an enlarged cross-sectional view of a main part after the wear of the hub wheel manufacturing mold of FIG. 10. It is a simplification figure showing a problem in conventional hub wheel manufacture.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st type 2 2nd type 4 Hub wheel 6 Flange 7a Tapered surface 8a Plane 11 Flange forging cavity 14 Hole part 16 Cavity corresponding surface 21 Hub bolt seat surface 25 Hub bolt seat surface formation part 27 Stepped surface

Claims (5)

In a mold device for manufacturing a hub wheel, comprising a mold having a first mold and a second mold, and forging the hub wheel in a closed state in which the first mold is fitted in the hole of the second mold,
In the mold closed state, a flange forging cavity is formed by the cavity-corresponding surface of the first mold and the inner diameter surface and the stepped surface of the hole of the second mold, and the anti-extrusion direction is formed on the inner diameter surface of the flange forging cavity. A hub apparatus for manufacturing a hub wheel, characterized in that a tapered surface having a diameter decreasing toward the side is provided.   The taper surface is provided on the anti-extrusion direction side of the inner diameter surface of the flange forging cavity, and a plane parallel to the axial direction is provided continuously from the taper surface on the extrusion direction side of the inner diameter surface of the flange forging cavity. The mold apparatus for manufacturing a hub wheel according to claim 1.   3. The hub wheel manufacturing gold according to claim 1, wherein the flange forging flange has a petal shape in which projecting portions projecting in an outer diameter direction are arranged at a predetermined pitch along a circumferential direction. Mold device.   The flange for forging flange has a large axial clearance dimension in a space for forging the hub bolt seat surface forming portion and a small axial clearance dimension in other portions. 3. A mold apparatus for producing a hub wheel according to any one of 3 above. A hub wheel manufacturing method for forming a hub wheel using the hub wheel manufacturing mold according to any one of claims 1 to 4,
A hub wheel manufacturing method comprising maintaining a hub bolt seat surface with a non-turned forged skin finish.

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