JP2008194741A - Method for manufacturing flange-structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a flange-structure with which the development of crack in this material can be restrained and a high quality hub-ring can be manufactured. <P>SOLUTION: This method for manufacturing the flange-structure, is the one, by which the flange-structure provided with a shaft member and the flange extended to the outer-diameter direction from the shaft member, is formed. This manufacturing method comprises a first process 21, in which a blank 36 being introduced into closed forging die devices with a forming die for cold-working to a solid or a hollow blank material 20, and a second process 22, in which the flange 12 for fitting a wheel is formed with the closed forging die devices by introducing the blank into the closed-forging die devices. Before introducing the blank material in the first process 21, a lubricating treatment 23 is performed, and before introducing the blank material in the second process 22, a softening treatment 20 and a lubricating treatment 25 are performed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flange structure manufacturing method for forming a flange structure (for example, a hub wheel of a wheel bearing device) including a shaft member and a flange extending in the outer diameter direction from the shaft member.

A wheel of an automobile or the like is rotatably supported via a wheel bearing device attached to a suspension device of a vehicle body. The wheel bearing device is formed by integrating a hub wheel, a rolling bearing, and a constant velocity universal joint.

  As shown in FIG. 10, the hub wheel 10 includes a shaft member 1, a wheel mounting flange 2 that protrudes from the outer diameter surface of the large diameter portion 1 a of the shaft member 1 in the outer diameter direction, and a wheel mounting flange 2. And a brake pilot 3 projecting on the opposite shaft side. The wheel mounting flange 2 is provided at an end portion on the outboard side of the shaft member 1 (an end portion on the outer side in the vehicle width direction in the assembled state in the automobile: the left end portion in FIG. 10). A hub bolt 4 is attached to each wheel mounting flange 2.

  A small-diameter step portion 6 is formed at an end portion on the inboard side of the hub wheel 10 (an end portion on the inner side in the vehicle width direction in the assembled state in the automobile: the right end portion in FIG. 10). 7 is fitted. An inner ring raceway surface 9 is formed on the outer peripheral surface of the inner ring 7, and an inner ring raceway surface 8 is formed on the outer peripheral surface in the axial direction of the hub ring 10. The tip of the hub wheel 10 on the inboard side is swaged outwardly in the radial direction to form a swaged portion 11, and the inner ring 7 is swaged and fixed to the hub wheel 10.

  An outer member (outer ring) 12 constituting a part of the rolling bearing includes a cylindrical main body 15 as a hollow shaft member provided with two rows of outer raceways 13 and 14 on the inner periphery thereof, and the cylindrical main body. A flange (vehicle body mounting flange) 16 is provided on the outer periphery of the portion 15. The first outer raceway surface 13 of the outer member 12 and the first inner raceway surface 8 of the hub wheel 10 face each other, and the second outer raceway surface 14 of the outer member 12 and the raceway surface 9 of the inner ring 7 are in contact with each other. Opposing and the rolling element 17 is interposed between these. The rolling element 17 is supported by a cage 18 disposed between the outer diameter surface of the shaft member 1 of the hub wheel 10 and the inner diameter surface of the outer member 12.

Such a hub wheel 10 forms a solid material or a hollow material by cold working (for example, Patent Document 1 and Patent Document 2). That is, as shown in FIG. 11A, the shaft member 20a of FIG. 11B is formed by subjecting the hollow cylindrical shaft material 20 to forward extrusion. Next, the head of the shaft member 20a is installed, and the shaft member 20b as shown in FIG. 11C is formed. Further, the shaft member 20b is subjected to a head rear extrusion to form a stepped shape that forms the inner peripheral shape of the shaft member 1 and the positioning cylinder portion (brake pilot) 3, as shown in FIG. 11 (d). A head 19 having a recess 19a is formed. Next, a side extrusion perpendicular to the pressing direction is performed on the shaft member (molding material) 20c molded as shown in FIG. 11 (d) using a molding die (closed forging die device) (not shown). Thus, as shown in FIGS. 11 (e) and 10, a hub wheel 10 in which the wheel mounting flange 2 and the brake pilot (positioning cylinder portion) 3 are integrated is formed.
JP 2006-1111070 A JP 2006-142983 A

  Thus, in the manufacturing methods described in Patent Document 1 and Patent Document 2, a solid material or a hollow material is selected according to the product shape, and all processes are formed by cold working. For this reason, the processing strain is accumulated and the strength can be improved by the processing hardness, and the cost can be reduced by the near net shape. Further, in the final molding, closed forging is performed, and because of the characteristics of this closed forging, since molding can be performed with a low load, there is an advantage that processing can be performed with small equipment.

  However, since all the processes are formed by cold working, the frictional resistance between the mold and the molded product is large in the closed forging process in the final forming as shown in FIGS. The resulting material crack B occurs. This material crack B occurs at the base of the wheel mounting flange 2. Thus, if the material crack B arises, strength will be reduced and it will become inferior goods which cannot function as a product (hub wheel).

  In view of the above problems, the present invention provides a flange structure manufacturing method capable of suppressing the occurrence of material cracking and manufacturing a high-quality hub wheel.

  The flange structure manufacturing method of the present invention is a flange structure manufacturing method for forming a flange structure including a shaft member and a flange extending in the outer diameter direction from the shaft member, and is a solid or hollow blank material A first step of forming a material to be put into a closed forging die apparatus by cold working forming, and the material is put into the closed forging mold apparatus and the wheel mounting flange is inserted into the closed forging mold apparatus. And a second process for forming the material, a lubrication process is performed before the blank material is charged in the first process, and a softening process and a lubrication process are performed before the material is charged in the second process.

  According to the flange structure manufacturing method of the present invention, in the first step, since cold work forming is performed on the blank material that has been subjected to the lubrication treatment, the friction generated between the mold and the blank material is reduced. It is possible to facilitate plastic working without causing seizure. Further, in the second step, since the closed forging is performed on the material subjected to the softening process and the lubrication process, the ease of plastic working can be improved.

  As the lubrication treatment, for example, a metal surface treatment called a phosphate coating treatment can be performed. This phosphate film treatment is also called chemical conversion treatment or bond treatment. This treatment serves to protect the metal itself by forming various phosphate compound layers on the surface of the metal (mainly iron). For this reason, by processing the processed material, there is a function of extending the life of the cold forging die or increasing the accuracy during forging. When using cold forging to perform press processing, using a processed material that is not lubricated by rubbing the mold and the material may cause adhesion between the mold and the material, material cracking, and die breakage. Can be prevented by performing a phosphate film treatment.

  The softening treatment is a heat treatment by spheroidizing annealing. Annealing (annealing) is a process in which when a metal material is in an unstable state during a processing step, it is stabilized by heat treatment. It can be heated to the vicinity of the A1 transformation point and then gradually cooled in the furnace to spheroidize the carbide (cementite) in the steel and improve the workability.

  In the flange structure manufacturing method of the present invention, it is possible to prevent high pressure from being applied to the mold in each step, and in the manufactured flange structure (hub wheel or the like), the conventional material cracking occurs. It can be avoided and high quality products can be provided. Moreover, damage to the mold used can be prevented, and the mold life can be increased.

  Lubricating treatment can be performed by bond processing, and softening processing can be performed by spheroidizing annealing, which improves the reliability of avoiding material cracking.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a process diagram of a flange structure manufacturing method, and this flange structure manufacturing method forms a hub ring as a flange structure as shown in FIGS. In this case, the hub wheel includes a shaft member 31 having a bearing raceway surface 34 formed on the outer periphery thereof, a wheel mounting flange 32 protruding in an outer diameter direction from the outer diameter surface of the large diameter portion 31a of the shaft member 31, This is a drive-side hub wheel provided with a brake pilot 33 protruding from the base portion of the wheel mounting flange 32 on the opposite shaft side. This hub wheel is a hub wheel in which four wheel mounting flanges 32 are arranged at a pitch of 90 ° along the circumferential direction as shown in FIG.

  In the flange structure manufacturing method, a solid blank 35 (see FIG. 2 (a)) is inserted into a closed forging die apparatus using a cold working mold (see FIG. 2 (c)). And a second step 22 in which the material 36 is put into a closed forging die device and a wheel mounting flange 32 is formed with the closed forging die device. In addition, the lubrication process 23 is performed before the blank material is charged in the first process 21, and the softening process 24 and the lubrication process 25 are performed before the second process.

  In the first step 21, the shaft-like member 35a shown in FIG. 2B is formed by subjecting the solid round bar material (blank material) 35 shown in FIG. Next, the head portion of the shaft-shaped member 35a is headed and immersed to the same diameter as the outer diameter of the brake pilot 3, thereby forming the material 36 shown in FIG.

  In the second step 22, the material (molding material) 36 is subjected to side extrusion perpendicular to the pushing direction by using a molding die (closed forging die device) (not shown), thereby FIG. 2 (d). As shown in FIG. 2, after forming the wheel mounting flange 2 and the brake pilot (positioning cylinder portion) 3, as shown in FIG. 2 (e), the hub is formed by drilling to form the shaft hole 37. 31 can be formed. Generally, a closed forging die apparatus includes a pair of dies provided so as to be openable and closable and a pair of punches that are driven in parallel with the opening and closing direction of the dies and press a material disposed in the dies. . In addition, the closed forging die apparatus in the 2nd process 22 of this invention can use the general thing used when shape | molding this kind of hub ring.

  The lubrication treatment 23 before the first step 21 is a metal surface treatment called a phosphate film treatment, for example. This phosphate film treatment is also called chemical conversion treatment or bond treatment. The purpose of the lubrication treatment is to reduce the friction generated between the mold and the material and facilitate plastic working without causing seizure.

  Specifically, the lubrication treatment 23 as the phosphate film treatment includes a phosphate treatment, a degreasing step and scale removal (pickling) performed before the phosphate treatment, and a reaction performed after the phosphate treatment. Processing such as mold soap lubrication.

  The degreasing step is a step of removing dirt such as lubricating oil and rust-preventing oil used before cutting the steel material. In this case, for example, a strong alkali type deconjugating agent is used. The components of the defecation are usually composed of an inorganic salt alkali builder and a surfactant. Alkaline pillers are mainly sodium orthosuccinate, sodium phosphate, caustic soda and sodium carbonate.

  As the scale removal, a shot plast method is used. In the lubrication process 23, pickling in the process is sufficient. However, since a large amount of scale is generated after the 24 softening process, the scale is removed before the 25 lubrication process. The shot plast method is a method of removing scales by projecting small particles of steel called shots on the surface, and pickling is to remove scale by passing it through an acid solution.

  The phosphate treatment is a treatment for forming a phosphate film having good adhesion on the descaled steel surface by immersing in an aqueous solution containing phosphoric acid and zinc as main components. Further, after the phosphate treatment, a reactive soap lubrication treatment is performed. Sodium stearate, which is the main component of soap, reacts with the zinc phosphate coating to produce a zinc stearate coating with good adhesion. The generated lubricating layer is a thin layer (about 2 to 5 μm), but this thin layer prevents direct contact between the metal fitting and the workpiece, and the excellent heat resistance and adhesion of the lubricating layer prevents seizure and galling. Generation can be prevented and severe processing can be performed.

  Moreover, the softening process 24 performed after completion | finish of a 1st process is the heat processing by spheroidizing annealing. Annealing (annealing) is a process in which when a metal material is in an unstable state during a processing step, it is stabilized by heat treatment. Heating up to the vicinity of the A1 transformation point and then gradually cooling in the furnace to make the carbide (cementite) in the steel a fine sphere is referred to as spheroidizing annealing. For this reason, the material 36 is softened. The lubrication process 25 performed after the first process is the same as the lubrication process 23 performed before the first process 21.

  Thus, as shown in FIG. 1, the flange structure manufacturing method of the present invention performs the lubrication process 23, the first process 21, the softening process 24, the lubrication process 25, and the second process 22 in sequence. A hub wheel as shown in FIG. 3 can be formed.

  In the present invention, in the first step 21, since cold work forming is performed on the blank material that has been subjected to the lubrication treatment, friction generated between the mold and the blank material 35 can be reduced, and seizure occurs. Therefore, plastic working can be facilitated. Further, in the second step 22, closed forging is performed on the material subjected to the softening process and the lubrication process, so that the ease of plastic working can be improved. For this reason, it is possible to prevent high pressure from being applied to the mold in each process, and in the manufactured flange structure (hub wheel, etc.), the conventional material cracking can be avoided, and high quality products can be avoided. Can provide. Moreover, damage to the mold used can be prevented, and the mold life can be increased.

  Further, a lubrication treatment can be performed by a bond treatment, and a softening treatment can be performed by spheroidizing annealing, so that reliability of avoiding material cracking is improved.

  In the above embodiment, the driving side is a hollow hub ring, but the hub ring may be a solid driven side. Even in this case, the lubrication process 23, the first process 21, the softening process 24, the lubrication process 25, and the second process 22 may be sequentially performed as shown in FIG.

  By the way, in this invention, the outward member (outer ring | wheel) of the wheel bearing apparatus can be shape | molded. As shown in FIGS. 4E and 7, the outer member (outer ring) 52 includes a main body cylinder portion 40 as a shaft member, and a flange 41 extending from the main body cylinder portion 40 in the outer diameter direction. The raceway surfaces 42 and 43 are formed on the inner diameter surface of the main body cylinder portion 40.

  That is, an upsetting process is performed on the shaft portion material 45 in FIG. 4A to form a disk-shaped member 45a as shown in FIG. Next, a pre-molding step is performed on the disk-shaped member 45a to mold a molding material 46 in which concave and concave portions 49 and 50 are formed on both sides as shown in FIGS. Thereafter, the molding material 46 is subjected to lateral extrusion using a molding die (closed forging die device) (not shown) so as to be orthogonal to the pressing direction, as shown in FIGS. 4D and 6. Then, a molded product 47 provided with the mounting flange 41 is molded. Thereafter, a hole forming process is performed on the molded product 47 to remove the partition portion 48 and form an outer ring as shown in FIGS.

  In this case, the step of forming the shape shown in FIGS. 4A to 4C is the first step 21, and the step of forming the shape shown in FIG. 4D is the second step. 22 And before the 1st process 21, the lubrication process 23 is performed, and the softening process 24 and the lubrication process 25 are performed to the raw material 36 shape | molded at the 1st process 21. FIG.

  For this reason, even if it is the manufacturing method shown in FIG. 4, there exists an effect similar to the method of manufacturing an above described hub ring.

  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 can be made. For example, in the hub wheel, even if the flange 2 has a disk shape. Good. When a plurality of flanges 2 are arranged along the circumferential direction as in the above embodiment, the number of flanges can be increased or decreased arbitrarily. Further, even in the case of the outer member (outer ring) of the wheel bearing device, the number of flanges can be increased or decreased.

  When the softening process 24 and the lubrication process 25 are performed on the material 36, the softening process 24 is performed first and the lubrication process 25 is performed later in the above embodiment, but conversely, the lubrication process 25 is performed first and the softening process is performed. 24 may be performed later. Further, the softening process 24 and the lubrication process 25 may be performed a plurality of times.

It is a simplified process diagram of a flange structure manufacturing method showing an embodiment of the present invention. It is process drawing of the said flange structure manufacturing method. It is a top view of the hub ring manufactured with the said flange structure manufacturing method. It is process drawing of the flange structure manufacturing method which shows other embodiment of this invention. It is a top view of the molding material shape | molded at the 1st process of the said flange structure manufacturing method. It is a top view of the molded product shape | molded at the 2nd process of the said flange structure manufacturing method. It is a top view of the outer ring | wheel shape | molded with the said flange structure manufacturing method. It is sectional drawing of the hub ring manufactured with the conventional flange structure manufacturing method. It is a top view of the hub wheel manufactured with the conventional flange structure manufacturing method. It is sectional drawing of the bearing apparatus for wheels. It is process drawing of the manufacturing method of the hub ring of the conventional wheel bearing apparatus.

Explanation of symbols

21 First step 22 Second step 23 Lubrication treatment 24 Softening treatment 25 Lubrication treatment 31 Shaft member 32 Wheel mounting flange

Claims (3)

A flange structure manufacturing method for forming a flange structure including a shaft member and a flange extending in an outer diameter direction from the shaft member,
A first step of forming a material to be put into a closed forging die apparatus by cold working molding of a solid or hollow blank material, and this closed forging mold apparatus by putting the material into a closed forging die apparatus And a second step of forming the flange, wherein a lubrication process is performed before the blank material is charged in the first process, and a softening process and a lubrication process are performed before the material is charged in the second process. A method for manufacturing a flange structure.   2. The flange structure manufacturing method according to claim 1, wherein the lubrication treatment is a bond treatment.   2. The flange structure manufacturing method according to claim 1, wherein the softening treatment is spheroidizing annealing.

Images