JP4961778B2 - Manufacturing method of bearing ring member for rolling bearing unit - Google Patents

Description

The present invention relates to an improvement in a method of manufacturing a bearing member for a rolling bearing unit such as a wheel supporting hub unit for rotatably supporting a wheel on a suspension device of an automobile. Specifically, it is intended to realize a manufacturing method for obtaining a lightweight rolling bearing unit bearing ring member at low cost.

  A wheel 1 constituting a wheel of an automobile and a rotor 2 constituting a disc brake serving as a braking device that is a braking rotating member rotate to a knuckle 3 constituting a suspension device, for example, by a structure as shown in FIG. Supports freely. That is, the outer ring 6 constituting the wheel support hub unit 5 is fixed to the circular support hole 4 formed in the knuckle 3 by a plurality of bolts 7. On the other hand, the wheel 1 and the rotor 2 are coupled and fixed to a hub 8 constituting the wheel support hub unit 5 by a plurality of studs 9 and nuts 10. Further, double-row outer ring raceways 11a and 11b are formed on the inner peripheral surface of the outer ring 6, and a coupling flange 12 is formed on the outer peripheral surface. Such an outer ring 6 is fixed to the knuckle 3 by connecting the connecting flange 12 to the knuckle 3 with the bolts 7.

  The hub 8 includes a hub body 13 and an inner ring 14. Among these, a mounting flange 15 is formed on a part of the outer peripheral surface of the hub body 13 and protruding from the outer end opening of the outer ring 6. Note that “outside” with respect to the axial direction refers to the left side of FIGS. On the contrary, the right side of FIGS. 14 and 15, which is the center side in the width direction of the vehicle in the assembled state in the automobile, is referred to as “inside” in the axial direction. The wheel 1 and the rotor 2 are coupled and fixed to the outer surface of the mounting flange 15 by the studs 9 and nuts 10.

  Further, an inner ring raceway 16a is formed in the middle portion of the outer peripheral surface of the hub body 13 so as to face the outer ring raceway 11a on the outer side of the double row outer ring raceways 11a, 11b. Further, the inner ring 14 is externally fitted to a small diameter step portion 17 formed at the inner end portion. An inner ring raceway 16b is formed on the outer peripheral surface of the inner ring 14 so as to face the inner outer ring raceway 11b of the double row outer ring raceways 11a and 11b. Such an inner ring 14 is fixed to the hub body 13 by a caulking portion 18 formed by plastic deformation of the inner end portion of the hub body 13 radially outward. A plurality of rolling elements 19, 19 are provided between the outer ring raceways 11a, 11b and the inner ring raceways 16a, 16b, respectively, so as to be able to roll. In the illustrated example, balls are used as the rolling elements 19, 19. However, in the case of a heavy vehicle hub unit, tapered rollers may be used. Further, both end openings of the cylindrical space in which the rolling elements 19 and 19 are installed are sealed with seal rings 20a and 20b, respectively.

Furthermore, since the illustrated example is a wheel support hub unit 5 for driving wheels (front wheels of FF vehicles, rear wheels of FR and RR vehicles, all wheels of 4WD vehicles), A spline hole 21 is formed. A spline shaft 23 fixed to the outer end surface of the constant velocity joint outer ring 22 is inserted into the spline hole 21. At the same time, a nut 24 is screwed onto the tip of the spline shaft 23 and further tightened , whereby the hub body 13 is sandwiched between the nut 24 and the constant velocity joint outer ring 22.

  Next, FIG. 15 shows a second example of a conventionally known wheel support hub unit for a driven wheel (rear wheel of FF vehicle, front wheel of FR vehicle and RR vehicle). Since the wheel support hub unit 5a of the second example is for a driven wheel, a spline hole is not provided at the center of the hub body 13a constituting the hub 8a. In the illustrated example, the inner end surface of the inner ring 14 is suppressed by a caulking portion 18 provided at the inner end portion of the hub main body 13a. However, the inner end surface of the inner ring 14 is the inner end portion of the hub main body 13a. It can also be suppressed by a nut screwed into the nut. In this case, a male screw portion for screwing the nut is provided at the inner end portion of the hub body 13a. The structure and operation of the other parts are the same as in the case of the wheel support hub unit 5 of the first example described above.

  By the way, in the case of each wheel supporting hub unit 5, 5a as described above, in any structure, the coupling flange 12 is provided on the outer peripheral surface of the outer ring 6, and the mounting flange 15 is provided on the outer peripheral surface of the hub bodies 13, 13a. Each is formed. As a method for manufacturing the outer ring 6 or the hub main bodies 13 and 13a in which the connecting flange 12 or the mounting flange 15 which is an outward flange is formed on the outer peripheral surface, plasticity such as hot forging or cold forging is used. In addition to processing, cutting and the like can be considered.

  However, in order to improve the processing efficiency and secure the yield of the material to reduce the cost, it is preferable to perform the plastic processing. Moreover, since hot forging can be processed in a soft state among the plastic working, the molding load can be kept small, but the metal material of each constituent part even in a state after the metal material is cooled after the processing is finished. Since the degree of curing is limited (only the degree of hardness increase accompanying a temperature decrease), sufficient strength may not always be obtained. In addition, since it is necessary to consider the difference in thermal expansion amount of the processing mold, it is difficult to ensure dimensional accuracy and shape accuracy. On the other hand, the base of the coupling flange 12 formed on the outer peripheral surface of the outer ring 6 or the base of the mounting flange 15 formed on the outer peripheral surface of the mounting flange 15 does not cause harmful deformation regardless of the moment applied during use. Therefore, it is necessary to ensure strength. When the outer ring 6 or the hub main bodies 13 and 13a are processed by hot forging, it is difficult to give the necessary strength to the base of the coupling flange 12 or the mounting flange 15 as it is. For this reason, the process for improving the intensity | strength of these bases separately is needed, and the manufacturing cost of the said outer ring | wheel 6 or the said hub main bodies 13 and 13a increases.

  On the other hand, as described in Japanese Patent Application No. 2004-298585, the outer ring 6 or the hub main body 13 having the coupling flange 12 or the mounting flange 15 on the outer peripheral surface by side extrusion, which is a kind of cold forging. , 13a is considered. In the case of carrying out such a manufacturing method of a bearing member for a rolling bearing unit using side extrusion processing according to the previous invention, a material having an outer peripheral surface as a cylindrical surface is used as the connecting flange 12 or the mounting flange. It is set in a mold having an inner surface shape corresponding to 15 outer surface shapes. In this state, a portion of the outer peripheral surface of the material excluding a portion where the coupling flange 12 or the mounting flange 15 is to be formed is suppressed. On the other hand, a space corresponding to each of the flanges 12 and 15 exists around the portion where the coupling flange 12 or the mounting flange 15 is to be formed. In this state, if the material is pressed in the axial direction (if the axial dimension is reduced), the metal material that has lost its place as the axial dimension is shortened is pushed into the space, and the outer peripheral surface In part, the coupling flange 12 or the mounting flange 15 is formed.

  If the outer ring 6 or the hub main body 13 or 13a provided with the coupling flange 12 or the mounting flange 15 is manufactured by side extrusion as described above, it is formed on the outer peripheral surface of the outer ring 6 or the hub main body 13 or 13a. The strength of the base of the coupling flange 12 or the mounting flange 15 can be increased. That is, these coupling flanges 12 or mounting flanges 15 are hardened by work hardening including the base part, so that post-treatment for improving the strength of this base part is unnecessary or necessary, and can be simplified. The manufacturing cost of the outer ring 6 or the hub main bodies 13 and 13a can be reduced. In addition, since it is not necessary to consider the difference in thermal expansion between the processing molds, it is easy to ensure dimensional accuracy and shape accuracy, and post-processing can be simplified or omitted, and the manufacturing cost can be reduced from this aspect as well. .

  However, in order to further improve the strength of the base portion of the coupling flange 12 or the mounting flange 15 for the purpose of weight reduction and the like, there is room for improvement in the manufacturing method according to the above-described prior invention. That is, as is widely known in the field of automobile technology, in order to improve driving performance such as riding comfort, handling stability, etc., or fuel efficiency, the road surface side is more than the springs that make up the suspension system. It is effective to reduce the so-called unsprung load, which is the weight of the member existing in the. The outer ring 6 or the hub main bodies 13 and 13a provided with the coupling flange 12 or the mounting flange 15 is naturally an unsprung load. Reducing the weight of the outer ring 6 or the hub main bodies 13 and 13a as much as possible is the above-mentioned performance. It is very advantageous from the aspect of improving.

In order to reduce the weight of the outer ring 6 or the hub main bodies 13 and 13a, the coupling flange 12 or the mounting flange 15 can be thinned (the axial dimension can be shortened). It is advantageous to improve the strength of the flange 15, particularly the strength of the base to which a large moment is applied during turning. From this aspect, the above-described manufacturing method of the prior invention still has room for improvement.
In addition, what was described in patent document 1 is known as a structure of the hub which is a bearing ring for rolling bearing units provided with the outward flange on the outer peripheral surface. However, the structure described in Patent Document 1 relates to a structure in which a part of a cylindrical material is bent and raised outward in the radial direction to form an outward flange, and the strength of the outward flange is improved to improve the hub. It is not intended to reduce weight.

JP 2003-25803 A

In view of the circumstances as described above, the present invention has been invented to realize a lightweight manufacturing method for a rolling bearing unit bearing ring member and a rolling bearing unit that can be obtained at low cost.

The bearing member for a rolling bearing unit that is a target of the manufacturing method of the present invention includes an outward flange on the outer peripheral surface and a raceway surface on any of the peripheral surfaces.
In the case of a rolling bearing unit race ring member produced by the manufacturing method of the present invention, the outer diameter of the material for constituting the rolling bearing unit race ring member is reduced at least on the base surface of the outward flange. There is a work hardened layer formed by carrying out direction handling.

Further, the rolling bearing unit is rotatable between an outer ring raceway member having an outer ring raceway having an outer ring raceway on an inner peripheral surface, an inner diameter raceway ring member having an inner ring raceway on an outer peripheral face, and the outer ring raceway and the inner ring raceway. A plurality of rolling elements. And at least one of the outer ring side bearing ring member and the inner diameter side bearing ring member is provided with an outward flange on the outer peripheral surface, and at least the base ring surface of the outward flange is provided with the bearing ring member. There is a work hardened layer formed by handling in the direction of reducing the outer diameter of the material for construction .
Such a rolling bearing unit, one of the raceway ring member of the the outside diameter side raceway ring member and the inner diameter side raceway ring member, and a stationary side raceway ring that does not rotate and is supported fixed to the suspension system in use state Similarly, the other bearing ring member is a hub that rotates together with the wheels in use.

The manufacturing method of a bearing ring member for a rolling bearing unit according to the present invention for manufacturing a bearing ring member that constitutes such a rolling bearing unit includes a material having an outer peripheral surface as a cylindrical surface, and an outer peripheral surface of the material. By performing a side extrusion process that presses in the axial direction without restraining the portion, a bearing ring member having an outward flange on a part of the outer peripheral surface is obtained.
In particular, in the case of the method for manufacturing a bearing ring member for a rolling bearing unit according to the present invention , at least a portion of the material in the axial direction, which is to be a base portion of the outward flange with the side extrusion, A handling process is performed to reduce the outer diameter of the material. Then, at least a portion to be the base portion is work-hardened to obtain an intermediate material in which a work-hardened layer exists over the entire circumference of this portion . Thereafter, the lateral extrusion is performed on the portion of the intermediate material where the work-hardened layer exists to form the outward flange, and at least the base portion of the outward flange is work-hardened by work-hardening. It consists of the part where the layer exists .

Moreover, when the manufacturing method of the bearing member for a rolling bearing unit of the present invention as described above is carried out , for example, as in the invention described in claim 2, the handling is performed with the outermost diameter among the above materials. By applying it to the entire large portion , a work hardened layer is formed over the entire surface layer portion of the portion having the largest outer diameter. And after the said handling process, a side extrusion process is given to the part in which this work hardening layer was formed, and the whole base part thru | or one axial side surface of the said outward flange are comprised in the part in which the said work hardening layer exists .
Alternatively, as in the invention described in claim 3, by performing the handling process on a part of the material in the axial direction of the portion having the largest outer diameter, the portion in the axial direction of the portion having the largest outer diameter is provided. A work hardening layer is formed on a part of the surface layer. Later, side extrusion that moves the part where this work hardened layer does not exist to the part where this work hardened layer exists and the part where this work hardened layer does not exist moves more radially outward than the part where this work hardened layer exists. Processing is performed, and the base portion of the outward flange is configured by a portion that is work-hardened by the handling processing. And after the said side extrusion process, the part hardened | cured by the said handling process does not exist in the radial direction outer side part among the axial direction one side surfaces of this outward flange.
Alternatively, as in the invention described in claim 4, prior to the handling processing, an intermediate material in which a part of the axial direction of the material is compressed in the axial direction to increase the outer diameter of a part of the axial direction Apply upsetting. After that, by applying the above-mentioned processing only to a portion of the intermediate material in the axial direction whose outer diameter has been increased by this upsetting process , a work hardening layer is formed on the surface layer portion of the portion having the increased outer diameter. Form. Later, side extrusion that moves the part where this work hardened layer does not exist to the part where this work hardened layer exists and the part where this work hardened layer does not exist moves more radially outward than the part where this work hardened layer exists. giving the process, the base of the outward flange together constituting a portion where the work-hardened layer is present, on the radially outboard portion among the axially one side of the outward flange, the absence of the work-hardened layer.

According to the manufacturing method of the rolling ring unit bearing ring member of the present invention configured as described above, a lightweight rolling ring bearing unit ring member and rolling bearing unit can be obtained at low cost.
In other words, since the outward flange is formed on the outer peripheral surface of the bearing ring member for the rolling bearing unit by side extrusion processing, which is plastic processing in the cold, the processing efficiency is improved, the yield of the material is secured, and the cost is increased. Reduction can be achieved. Further, the hardness of the outward flange is improved from the hardness of the material by work hardening accompanying cold plastic working, so that it is easy to ensure the strength of the outward flange.
Moreover, in the case of the present invention, at least on the surface of the base portion of the outward flange, in order to present the work hardened layer formed by ironing work to reduce the outer diameter of the material, the strength of the base of the outward flange, more Can be improved.
Accordingly, the strength of the outward flange can be sufficiently increased, and the outer ring flange can be made lighter, and hence the rolling bearing unit can be easily reduced in weight, and further reduced in weight.

[First example of embodiment]
1-3 show a first example of an embodiment of the present invention corresponding to claims 1 and 2 . This example is intended to manufacture the hub body (ring ring member) 13a constituting the wheel bearing rolling bearing unit for the driven wheel as shown in FIG. 15 by the manufacturing method of the present invention. is there. 2 shows the working state of handling processing and FIG. 3 shows the state of side extrusion processing. In FIGS. 2 to 3, the right half is the state immediately before the start of processing, and the left half is The state immediately after the end of processing is shown.

  First, the columnar material 25 shown in FIG. 1 (A) is subjected to a first-stage forward extrusion process to obtain a stepped first intermediate material 26 as shown in FIG. 1 (B). . The forward extrusion process, which is a kind of cold plastic working, pushes the material 25 into the receiving mold having an inner peripheral surface shape that matches the outer peripheral surface shape of the first intermediate material 26 with a pressing die. By doing things. Such forward extrusion processing can be performed by a general method well known in the field of metal processing. The ratio of the outer diameter of the small diameter portion 27 and the outer diameter of the large diameter portion 28 of the first intermediate material 26 is large, or the inclination angle of the inclined portion 29 between these both portions 27 and 28 is steep. In such a case, a floating die that moves in the axial direction together with the material 25 is used. That is, the material 25 is pushed into the receiving die by the pressing die while the outer peripheral surface of the material 25 is suppressed by the floating die (so that the outer diameter does not expand). The forward extrusion process using the floating die is disclosed in detail in Japanese Patent Application No. 2005-354469, and is not related to the gist of the present invention.

The first intermediate material 26 is subjected to a second-stage forward extrusion process to obtain a second intermediate material 30 as shown in FIG. The second-stage forward extrusion process is basically performed in the same manner as the first-stage forward extrusion process described above. Needless to say, the shape of the inner peripheral surface of the receiving mold is made different from the shape of the outer peripheral surface of the second intermediate material 30. A floating die is used as necessary.
Next, the second intermediate material 30 is subjected to a stepping process and an upsetting process for forming a stepped portion or the like for providing an axially outer angular inner ring raceway 16a (see FIG. 15). A third intermediate material 31 as shown in FIG. The stepping process and the upsetting process for obtaining the third intermediate material 31 from the second intermediate material 30 are performed by holding the second intermediate material 30 while suppressing the outer peripheral surface of the second intermediate material 30 with a die. It is performed by pressing in the axial direction between the receiving die and the pressing die. Such stepping and upsetting can be easily performed by a metalworking engineer and is not directly related to the gist of the present invention, so illustration and detailed description are omitted.

When the third intermediate material 31 is obtained, the third intermediate material 31 is referred to as the “material” described in the claims and the above-mentioned “Means for Solving the Problems”. The material 31 (material) is treated. As shown in FIG. 2, this handling process is performed by pushing the third intermediate material 31 into a thick cylindrical handling mold 32 with a punch 33.
Of these, the handling die 32 is formed with a center hole 34 having a circular cross section for handling the outer diameter of the third intermediate material 31. The inner diameter R of the inlet side end (upper end in FIG. 2) of the center hole 34 is the same as or larger than the outer diameter D of the base half (upper half of FIGS. 1 and 2) of the third intermediate material 31. Slightly larger than the diameter D (R ≧ D). On the other hand, the inner diameter r of the handling projection 35 provided on the inner peripheral surface of the intermediate portion of the center hole 34 over the entire circumference is slightly smaller than the outer diameter D of the base half portion of the third intermediate material 31. Small (r <D). The inner peripheral surface of the inlet side end portion of the center hole 34 and the inner peripheral surface of the handling protrusion 35 are smoothly continued.
On the other hand, the punch 33 has an outer diameter d (d <D) smaller than the outer diameter D of the base half of the third intermediate material 31, and the base end surface of the third intermediate material 31 (FIGS. 1-2). The tip surface facing the upper end surface is a convex surface having a substantially partial spherical shape. Specifically, the generatrix shape of the tip surface of the punch 33 is a shape in which a pair of quarter arcs are continuous with a straight line.

  In order to handle the third intermediate material 31 with the handling device 36 comprising the handling mold 32 and the punch 33 as described above, first, as shown in the right half of FIG. The intermediate material 31 is inserted into the handling mold 32 with the first half (the lower half of FIGS. 1 and 2) first. The base half of the third intermediate material 31 is fitted into the inlet side end of the center hole 34 without rattling. Next, the front end surface of the punch 33 is abutted against the base end surface of the third intermediate material 31, and the third intermediate material 31 is pushed into the center hole 34. As a result, the entire base half portion of the third intermediate material 31 is handled by the handling projection 35 provided in the middle portion of the center hole 34, and the outer diameter thereof is the inner diameter of the handling projection 35. In the same manner as described above, while being reduced to r, it is pushed into the center hole 34 and further passes through the center hole 34. At the same time, a substantially spherical concave portion 37 that matches the shape of the tip end surface of the punch 33 is formed on the base end surface of the third intermediate material 31, and is formed in the left half of FIG. This is the fourth intermediate material 38 as shown.

  Comparing the third intermediate material 31 with the fourth intermediate material 38, the fourth intermediate material 38 has the recess 37 formed on the base end surface, and the outer diameter r of the base half is third. It is slightly smaller than the intermediate material 31 (outer diameter of the base half = D), and is generated in the surface layer portion {the oblique lattice portion of FIG. The work-hardened layer 39 exists over the entire surface (the entire length of the base half portion × the entire circumference). The thickness of the work hardened layer 39 and the degree of work hardening (hardness) are the outer diameter D of the base half of the third intermediate material 31 and the end of the center hole 34 on the inlet side. It can be arbitrarily adjusted by the difference (D−r) from the inner diameter r of the portion excluding the portion.

Further, the fourth intermediate material 38 is subjected to a side extrusion process and a process for forming the inner ring raceway 16a to obtain a hub body 13a as shown in FIG.
The side extrusion process is performed, for example, by the method disclosed in the aforementioned Japanese Patent Application No. 2004-298585. That is, as shown in FIG. 3, in a state where the fourth intermediate material 38 is held inside the upper die 40 and the lower die 41, it is pressed in the axial direction by the pressing die 42, and the metal material is released radially outward. The mounting flange 15 is formed (by flowing).

  The upper die 40 is supported below the upper plate 43 fixed to the ram of the press machine via an elastic material 44, and the pressing die 42 is fixed to the lower surface of the upper plate 43. The lower die 41 is fixed above a lower plate 45 fixed to the upper surface of the base of the press machine. Then, in a state where the lower surface of the upper mold 40 and the upper surface of the lower mold 41 are abutted with each other, a molding space 46 having an inner surface shape corresponding to the outer surface shape of the mounting flange 15 is formed between both surfaces. I am doing it.

  The fourth intermediate material 38 is plastically deformed to form the mounting flange 15, and the hub main body 13a (or the fifth intermediate material having a shape close to the hub main body 13a) shown in FIG. Work is done as follows. First, the upper mold 40 and the pressing mold 42 are raised together with the ram, and the leading half of the fourth intermediate material 38 is inserted into the center hole of the lower mold 41 to set the lower mold 41. To do. Next, the upper die 40 and the pressing die 42 are lowered together with the ram, and the fourth intermediate material 38 is held inside the upper die 40 and the lower die 41 as shown in the right half of FIG. From this state, the pressing die 42 is further lowered together with the ram so that the metal material flows into the molding space 46 while the recess 37 existing on the base end surface of the fourth intermediate material 38 is processed into a deeper recess 37a. Thus, the mounting flange 15 is formed. The peripheral portion of the concave portion 37a is a positioning cylinder portion 48 for externally fitting a disc brake disc and a wheel center hole in use.

  The work hardened layer 39 formed by the handling process exists on the outer peripheral surface of the positioning cylinder portion 48, the outer surface of the mounting flange 15, and the continuous portion of both surfaces formed in this manner. It becomes a state. Therefore, the positioning cylinder portion 48 and the mounting flange 15 not only increase in hardness by work hardening due to plastic deformation accompanying the pressing of the pressing die 42 but also increase in hardness due to the presence of the work hardening layer 39. Therefore, the required strength can be secured even if the thickness dimensions of the positioning cylinder portion 48 and the mounting flange 15 are kept small, and the above-described effects can be obtained. That is, the fourth intermediate material 38 having the work-hardened layer 39 partially formed by the handling process is subjected to a side extrusion process, and the work-hardened layer 39 is particularly positioned with high strength. It arrange | positions in the continuous part of the cylinder part 48 and the said attachment flange 15 for it. In short, the entire hub main body 13a is not work-hardened, but it is hardened by work only at a portion requiring strength. As a result, the hub body 13a having high strength (lightweight while ensuring the required strength) can be manufactured while ensuring the action and effect that the mounting flange 15 can be easily processed by side extrusion.

  In other words, when the side extrusion is performed as described above, the work-hardened layer 39 based on work-hardening by handling is present in the base half of the fourth intermediate material 38 that is a workpiece. The processing load increases. However, the work-hardened layer 39 is only partially present, and since the thickness of the work-hardened layer 39 is limited, an increase in work load can be suppressed slightly. That is, when the fourth intermediate material 38 shown in FIG. 1E is plastically deformed to form the hub body 13a shown in FIG. 1F, the work hardened layer 39 is bent while being bent. Although it is necessary to flow outward in the direction, the increase in processing load required for this bending and flow is small. For this reason, an increase in load applied to each mold such as the upper mold 40, the lower mold 41, and the pressing mold 42 can be suppressed slightly, and a decrease in mold life can be reduced.

  The hub main body 13a obtained as described above (or the fifth intermediate material having a shape close to the hub main body 13a) is taken out from the side extrusion processing apparatus shown in FIG. Accordingly, after finishing such as polishing and heat treatment, the wheel support hub unit 5a as shown in FIG. 15 is combined with other members. The operation of removing the hub body 13a from the side extrusion processing apparatus is performed by raising the upper die 40 and the pushing die 42 together with the ram and then raising the knockout pin 47 provided at the center of the lower die 41. The hub body 13a is pushed out from the center hole of the lower die 41.

[Second Example of Embodiment]
4 to 5 show a second example of an embodiment of the present invention corresponding to claims 1 and 3 . FIGS. 4A to 4F show the overall configuration when the hub body 13a is made from the columnar material 25 according to this example, but the steps (A) to (D) of these, That is, the process of sequentially processing the material 25 → the first intermediate material 26 → the second intermediate material 30 → the third intermediate material 31 is the same as that in the first example of the above-described embodiment. In particular, in the case of this example, the step of handling the third intermediate material 31 to form the fourth intermediate material 38a shown in FIG. 4E is the same as the first example of the above embodiment. Is different.

That is, in the case of the first example, as shown in FIGS. 1D to 1E and FIG. 2, the entire surface of the base half of the third intermediate material 31 having the largest outer diameter ( The fourth intermediate material 38 in which the work-hardened layer 39 is formed on the entire surface of the base half portion is obtained by carrying out handling processing over the entire length × the entire circumference. On the other hand, in the case of this example, the base half portion having the largest outer diameter among the third intermediate materials 31 corresponding to the material described in claim 3 { D) Upper half, lower half of FIG. 5} (the upper end or middle part of FIG. 4 or lower end or middle part of FIG. 5). In other words, the remaining part of the base half {the lower end of FIG. 4D, the upper end of FIG. 5} is not subjected to the above-described processing. Therefore, after the handling process, the surface layer portion of the base half of the fourth intermediate material 38a has the work hardened layer 39a only in the part and the work hardened layer does not exist in the remaining part. .

In order to form the work-hardened layer 39a as described above, in the case of this example, the handling process is performed in the opposite direction to the case of the first example, as shown in FIG. That is, the third intermediate material 31 is pushed from the base half side into a handling die 32 provided with handling protrusions 35 on the inner peripheral surface over the entire circumference. This pushing operation is performed by pressing the step surface 52 provided at the intermediate portion of the third intermediate material 31 with the tip surface of the cylindrical punch 49. Further, the pressing operation by the punch 49 is from the state shown in the right half of FIG. 5 to the state shown in the left half, that is, a part of the base half of the third intermediate material 31 is used for the handling. Until the projection 35 is passed, in other words, the remaining portion of the base half is not handled by the handling projection 35 and remains. By the handling process performed in this manner, the fourth intermediate material 38a having the work hardened layer 39a in a part of the base half as shown in FIG. 4E can be obtained. Among the groups half of the fourth intermediate material 38a, the outer diameter D ₁ of the remainder is not covered by the work hardening layer 39a is the same as the outer diameter D ₁ of the groups half of the third intermediate material 31 . In contrast, the outer diameter D ₂ of the portion forming the work hardened layer 39a is smaller than the outer diameter D ₁ of the groups half of the third intermediate material 31 (D 2 _{<D 1)} . In addition, due to the handling, a portion near the outer diameter of the base end portion of the fourth intermediate material 38a projects in the axial direction, and a concave portion 37b is formed on the base end surface of the fourth intermediate material 38a.

Such a fourth intermediate material 38a is extruded from the handling die 32 by means of a counter punch (not shown) and then sent to the next side extrusion process, and the portion corresponding to the remaining portion in the base half is radially arranged. Plastically deform outward. Then, a mounting flange 15 is formed in this portion to form the hub main body 13a (or the fifth intermediate material having a shape close to the hub main body 13a) shown in FIG. The side extrusion processing using the fourth intermediate material 38a as the hub body 13a is performed as shown in FIG. 3 as in the case of the first example of the embodiment described above. In this case, the remaining portion (outer diameter D ₁ ) of the base half of the fourth intermediate material 38a that is not covered by the work hardened layer 39a is the inner diameter side end of the molding space 46 (see FIG. 3). as entering the axial position of the balance, and properly regulating the axial dimension L _1.

  In the case of this example configured as described above, the portion where the work hardened layer 39a is provided is hung from the outer peripheral surface of the positioning cylinder portion 48 to the outer surface of the mounting flange 15 where it is particularly necessary to improve the strength. It can be limited to the part. In other words, no work hardened layer is present in the radially outer portion of the outer surface of the mounting flange 15. For this reason, the strength of the required portion can be ensured while the processing load required in the side extrusion step is kept lower. Since the configuration and operation of the other parts are the same as in the case of the first example of the above-described embodiment, a duplicate description is omitted.

[Third example of embodiment]
FIGS. 6-8 has shown the 3rd example of embodiment of this invention corresponding to Claim 1,4 . 6 (A) to 6 (F) show the overall configuration when the hub body 13a is made from the cylindrical material 25 according to this example, the steps (A) to (C) of these, That is, the process of sequentially processing the material 25 → the first intermediate material 26 → the second intermediate material 30 is the same as in the first example of the above-described embodiment and the second example of the above-described embodiment. It is. In particular, in the case of this example, the second intermediate material 30 is processed into a third intermediate material 31a, and the third intermediate material 31a is further processed to be processed as shown in FIG. The step of forming the intermediate material 38b is different from the first and second examples of the above embodiment.

That is, in the case of this example, in the process of processing the second intermediate material 30 into the third intermediate material 31a, which is performed prior to handling, one of the second intermediate materials 30 corresponding to the material of claim 4 is used. The part is compressed in the axial direction. That is, the second intermediate material 30 is fitted into a center hole 54 of the receiving die 53 as shown in FIG. The center hole 54 has an inner peripheral surface shape that matches the outer peripheral surface shape of the third intermediate material 31a. When the second intermediate material 30 is pushed into the center hole 54 by the punch 55 in a state in which the second intermediate material 30 is fitted in the center hole 54, the second intermediate material 30 is plastically deformed. The outer peripheral surface is shaped to match the inner peripheral surface of the center hole 54, and becomes the third intermediate material 31a. At this time, the proximal end of the second intermediate material 30 (the upper end in FIG. 6-7), the outer diameter of the portion axial dimension is L ₂ is, upsetting is axially compressed by the punch 55 By processing, it expands from D ₁ to D ₂ (D ₁ <D ₂ , where D ₁ , D ₂ are different in size from the second example of the embodiment described above).

Such a third intermediate material 31a is treated as shown in FIG. 8 so that a work hardening layer 39b is formed on a part of the base half as shown in FIG. 6E. The formed fourth intermediate material 38b is used. As in the case of the first example of the embodiment described above, this handling process is performed as shown in FIG. 8 by placing the third intermediate material 31a in the center hole 34 of the thick cylindrical handling mold 32. This is done by pushing in with the punch 33. However, in the case of this example, among the groups half of the third intermediate material 31a, the outer diameter of spread D _2, only the portion axial dimension is L _2, the center hole 34 ironing the ironing projection 35 of the inner peripheral surface, the outer diameter of this portion is shortened to a D _3, to form the work hardening layer 39b in the portion. At the same time, a substantially partial spherical concave portion 37 that matches the shape of the tip end surface of the punch 33 is formed on the base end surface of the third intermediate material 31a, and is formed in the left half of FIG. 6E and FIG. The fourth intermediate material 38b as shown is used. The outer diameter D ₃ after the ironing work is either equal to the outer diameter D ₁ of the previous upsetting the slightly smaller (D ₃ ≦ D ₁₎ to. In any case, the handling is performed over the entire length of the base half of the third intermediate material 31a, as is apparent from FIG. 8, so that there is no step in the base half after the handling. Become. In this case, when the D ₃ the outer diameter after the ironing work were slightly smaller than the outer diameter D ₁ of the previous upsetting above, the portion (the third the outer diameter of D ₁ among groups half of the intermediate material 31a, the axial dimension in portions) other than the portion which is L _2, slightly ironing work is performed. However, the outer diameter of the portion which is D _1, is not be work hardened layer of extent of the resistance to the next lateral extrusion is formed.

  Such a fourth intermediate material 38b is extruded from the handling die 32 by a counter punch (not shown), and then sent to the next side extrusion process, and is covered with the work hardened layer 39b in the base half. The part which does not exist is plastically deformed radially outward. Then, a mounting flange 15 is formed in this portion to form the hub main body 13a (or the fifth intermediate material having a shape close to the hub main body 13a) shown in FIG. The side extrusion processing using the fourth intermediate material 38b as the hub body 13a is performed as shown in FIG. 3 as in the case of the first example of the embodiment described above.

In the case of this example configured as described above, as in the case of the second example of the above-described embodiment, the portion where the work hardened layer 39b is provided needs to be improved in strength in particular. The portion can be limited to a portion extending from the outer peripheral surface of 48 to the outer surface of the mounting flange 15. For this reason, the strength of the required portion can be ensured while the processing load required in the side extrusion step is kept lower.
Particularly in the case of this example, the degree of freedom of the portion where the work hardened layer 39b is provided can be made larger than in the case of the second example. That is, it is not necessary to form a work hardened layer over the entire length of the base half as in the first example of the above-described embodiment, and no work hardened layer is formed as in the second example. There is no need to regulate the axial dimension of the part (having a diameter larger than the part where the work hardened layer is formed) in relation to the dimension of the molding space.

Furthermore, in the case of this example, the handling amount (outer diameter difference before and after the handling process) can be set to some extent, and work hardening associated with upsetting to increase the outer diameter can also be used. The hardness of the work hardened layer 39b obtained by the embedding process → the handling process can be further increased.
Accordingly, in the case of the present example, the strength of the required portion can be further increased while suppressing the increase in the processing load slightly.
Since the configuration and operation of the other parts are the same as in the case of the first example of the above-described embodiment, a duplicate description is omitted.

[Fourth Example of Embodiment]
9 to 11 show a fourth example of an embodiment of the present invention corresponding to claims 1 and 2 . This example shows a case where the present invention is applied to the outer ring 6 (see FIGS. 14 to 15) constituting the wheel supporting hub units 5 and 5a. 9 to 11, FIG. 9 shows all steps for processing the cylindrical material 50 into the third intermediate material 51 having a shape close to the outer ring 6. First, the material 50 shown in FIG. 9A is a first intermediate having a stepped outer peripheral surface as shown in FIG. 9B by forward extrusion, which is a kind of cold forging. The material 56 (the material described in the claims) is processed. This forward extrusion process is performed by pushing the material 50 into an outer mold having a stepped inner peripheral surface in a state where the material 50 is fitted on a cylindrical mandrel. The forward extrusion process is disclosed in the above-mentioned Japanese Patent Application No. 2004-298585, and is not related to the gist of the present invention.

  The first intermediate material 56 is treated as a feature of the present invention to form a second intermediate material 57 as shown in FIG. As shown in FIG. 10, this handling is performed by pushing the first intermediate material 56 into the center hole 34 of the handling die 32 with a cylindrical punch 49 in a state where the first intermediate material 56 is externally fitted to the mandrel 58. That is, in the first intermediate material 56, the half piece in the axial direction whose outer diameter is increased is handled by the handling protrusion 35 formed in the middle part of the center hole 34, and the half of the half piece in the axial direction is handled. At the same time as reducing the outer diameter, a work hardened layer 39c is formed on the surface portion of the half piece in the axial direction to form the second intermediate material 57.

  Such a second intermediate material 57 is subjected to a side extrusion process to form a third intermediate material 51 having a shape close to the outer ring 6 as shown in FIG. This side extrusion is performed as shown in FIG. The basic structure of the side extrusion processing apparatus shown in FIG. 11 is the same as that of the apparatus shown in FIG. However, in the case of this example, since each of the intermediate materials 57 and 51 is hollow cylindrical, it is intended to process the second intermediate material 57 into the third intermediate material 51. A mandrel 59 is provided to prevent deformation inward in the direction.

  In order to process the second intermediate material 57 into the third intermediate material 51, first, the second intermediate material 57 is made up of an upper mold 60 and a lower mold 61 as shown in the right half of FIG. More specifically, the upper half inner peripheral surface of the lower mold 61 and the upper outer peripheral surface of the mandrel 59 are mounted. This mounting operation is performed with the upper die 60 and the upper punch 62 raised together with the ram of the press machine. Next, the ram that has been raised is lowered. First, as shown in the right half of FIG. 11, a portion near the upper surface outer diameter of the lower die 61 and a portion near the lower surface outer diameter of the upper die 60. Match. Next, the ram is further lowered, and the second intermediate material 57 is strongly pressed toward the lower punch 63 by the upper punch 62. At this time, the elastic member 64 provided above the upper mold 60 is elastically compressed. In this state, only the upper punch 62 is lowered while the portion near the upper surface outer diameter of the lower die 61 and the portion near the lower surface outer diameter of the upper die 60 are in close contact with each other. As a result, the lower half portion of the second intermediate material 57 is plastically deformed, and from the inner peripheral surface of the lower half portion of the lower mold 61 and the outer peripheral surface of the mandrel 59, from the face pressing portion 65. Is also pushed into the cylindrical space 66 between the lower part. Then, the lower half portion of the second intermediate material 57 is plastic processed into a shape following the cylindrical space 66. In this state, one (axially outer) outer ring raceway 11a is formed.

  The lowering of the upper punch 62 continues until after the lower half of the second intermediate material 57 has been completely pushed into the cylindrical space 66. As a result, a part of the second intermediate material 57 flows (flows) into the molding space 46a existing at the abutting portion between the upper mold 60 and the lower mold 61, and the coupling flange 12 is formed. In this state, the second intermediate material 57 is processed into the third intermediate material 51 that is closer to the shape of the outer ring 6. In the third intermediate material 51, a work hardened layer 39c is present at a portion extending from the axial end to one axial side surface of the coupling flange 12. For this reason, the strength of the connecting flange 12 portion can be sufficiently secured.

If such a third intermediate material 51 is processed, then the ram is raised again, and the third intermediate material 51 formed with the coupling flange 12 is taken out. This take-out operation is performed by raising the lower punch 63 that also functions as a knockout pin. And the other (axially inner side) outer ring raceway 11b (see FIGS. 14 to 15) is formed on the inner peripheral surface of the third intermediate material 51 taken out, and necessary portions of the inner peripheral surface are quenched and hardened. After the necessary post-processing (post-processing such as necessary cutting, heat treatment, and grinding) is combined with other members, the rolling bearing unit for wheel support as shown in FIGS. And
Since the configuration and operation other than the change of the configuration of each part in accordance with the change of the bearing ring member for the rolling bearing unit from the hub body to the outer ring are the same as those in the first example of the above-described embodiment, The description to be omitted is omitted.

[Fifth Example of Embodiment]
FIG. 12 shows a fifth example of an embodiment of the present invention corresponding to claims 1 and 3 . FIGS. 12A to 12D show the overall configuration when the third intermediate material 51 having a shape close to the outer ring 6 is formed from the cylindrical material 50 according to this example. The process (B) is the same as in the case of the fourth example of the embodiment described above. In particular, in the case of this example, the first intermediate material 56 shown in (B) of FIG. 12 is processed to form the second intermediate material 57a shown in (C). It differs from the 4th example of form.

That is, in the case of this example, as in the case of the second example of the above-described embodiment, the outer diameter of the first intermediate material 56 corresponding to the material described in claim 3 is handled. Is applied to a part {the upper half to the middle part of FIG. 12B} of the half part {the upper half part of FIG. 12B}. In other words, the above-described handling process is not performed on the remaining portion of the half portion {the lower end portion in FIG. 12B). Accordingly, the surface hardened portion 39d of the second intermediate material 57a after the handling process has the work hardened layer 39d only in the part and the work hardened layer in the remaining part. However, the outer diameter is larger than this part.
The configuration and operation other than changing the configuration of each part in accordance with the change of the bearing ring member for the rolling bearing unit from the hub main body to the outer ring and using the mandrel at each processing are the same as in the second embodiment. Since it is the same as that of the example, the overlapping description is omitted.

[Sixth Example of Embodiment]
FIG. 13 shows a sixth example of an embodiment of the present invention corresponding to claims 1 and 4 . In the case of this example, the outer diameter of one end of the first intermediate material 56a {the upper end of FIG. 12B} is made larger than the other parts by upsetting. Then, by handling this part, a second intermediate material 57b having a part of the work hardened layer 39e as shown in FIG. 13C is obtained.
The configuration and operation other than changing the configuration of each part in accordance with the change of the bearing ring member for the rolling bearing unit from the hub main body to the outer ring and using the mandrel at each processing are the same as in the third embodiment. Since it is the same as that of the example, the overlapping description is omitted.
In addition, when the present invention is applied to the hub body for a driving wheel having a spline hole at the center as shown in FIG. 14 described above, as in the case of applying the present invention to the outer ring, Use a mandrel.

Sectional drawing and end elevation which show the 1st example of embodiment of this invention in order of a process process. Sectional drawing which shows the implementation condition of the handling process in a 1st example. Sectional drawing which similarly shows the implementation status of a side extrusion process. Sectional drawing and end elevation which show the 2nd example of embodiment of this invention in order of a process process. Sectional drawing which shows the implementation condition of the handling process in a 2nd example. Sectional drawing and end elevation which show the 3rd example of embodiment of this invention in order of a manufacturing process. Sectional drawing which shows the implementation condition of the stepping process and upsetting process to an outer peripheral surface in a 3rd example. Sectional drawing which similarly shows the implementation condition of handling processing. Sectional drawing and end elevation which show the 4th example of embodiment of this invention in order of a process process. Sectional drawing which shows the implementation condition of the handling process in a 4th example. Sectional drawing which similarly shows the implementation status of a side extrusion process. Sectional drawing and end elevation which show the 5th example of embodiment of this invention in order of a manufacturing process. Sectional drawing and end elevation which show the 6th example of embodiment of this invention in order of a process process. Sectional drawing which shows an example of the hub unit for wheel support for drive wheels in the state assembled | attached to the knuckle. Sectional drawing which shows one example of the hub unit for wheel support for driven wheels.

DESCRIPTION OF SYMBOLS 1 Wheel 2 Rotor 3 Knuckle 4 Support hole 5, 5a Wheel support hub unit 6 Outer ring 7 Bolt 8, 8a Hub 9 Stud 10 Nut 11a, 11b Outer ring track 12 Coupling flange 13, 13a Hub body 14 Inner ring 15 Mounting flange 16a, 16b Inner ring raceway 17 Small diameter step portion 18 Caulking portion 19 Rolling element 20a, 20b Seal ring 21 Spline hole 22 Outer ring for constant velocity joint 23 Spline shaft 24 Nut 25 Material 26 First intermediate material 27 Small diameter portion 28 Large diameter portion 29 Inclined portion 30 First Second intermediate material 31, 31a Third intermediate material 32 Handling mold 33 Punch 34 Center hole 35 Handling protrusion 36 Handling device 37, 37a, 37b Recess 38, 38a, 38b Fourth intermediate material 39, 39a, 39b, 39c , 39d, 39e Work hardening layer 40 Upper mold 41 Lower mold 42 Push mold 43 Upper plate 44 Elastic material 45 Lower plate 46, 46a Molding space 47 Knockout pin 48 Positioning tube portion 49 Punch 50 Material 51 Third intermediate material 52 Stepped surface 53 Receiving die 54 Center hole 55 Punch 56, 56a First intermediate material 57, 57a, 57b Second intermediate material 58 Mandrel 59 Mandrel 60 Upper die 61 Lower die 62 Upper punch 63 Lower punch 64 Elastic member 65 Surface pressing portion 66 Cylindrical space

Claims (4)

A bearing ring having an outward flange on a part of the outer peripheral surface by subjecting the material having an outer peripheral surface to a cylindrical surface to side extrusion that presses in an axial direction without suppressing a part of the outer peripheral surface of the material. A method of manufacturing a bearing ring member for a rolling bearing unit as a member, wherein at least a portion of the material in the axial direction is to be a base portion of the outward flange along with the side extrusion. By applying a handling process that reduces the outer diameter of the material, at least the part that should be the base is work-hardened to make an intermediate material that has a work-hardened layer over the entire circumference of this part . the portion where the work-hardened layer is present is subjected to the lateral extrusion to form the said outward flange in out, at least the base of the outward flange, to configure a portion where the work-hardened layer is present Method of manufacturing a rolling bearing unit for bearing ring member. By applying the processing to the entire part with the largest outer diameter of the material , the work hardened layer is formed over the entire surface layer of the part with the largest outer diameter, and then this work hardened layer is formed. The method of manufacturing a bearing member for a rolling bearing unit according to claim 1 , wherein the extruded portion is subjected to a side extrusion process, and the base portion or the entire axial one side surface of the outward flange is constituted by the portion where the work hardening layer exists. . After forming a work hardened layer on a part of the surface layer in the axial direction of the portion with the largest outer diameter by applying a handling process to a part of the material in the axial direction of the portion with the largest outer diameter, Side extruding is performed on the part where the work hardened layer exists and the part where the work hardened layer does not exist so that the part where the work hardened layer does not exist is moved radially outward from the part where the work hardened layer exists. subjected to, the base of the outward flange together constituting a portion where there is the work hardening layer, the absence of the work hardening layer in the radial direction outboard portion among the axially one side of the outward flange, claim 1 The manufacturing method of the bearing ring member for rolling bearing units described in 2 .. Prior to ironing work, by compressing a portion of the axial direction of the material in the axial direction after being subjected to upsetting the intermediate material obtained by increasing the outer diameter of a portion of the axial axis of the intermediate material After forming the work hardened layer on the surface layer of the part where the outer diameter is increased by applying the above-mentioned processing only to the part where the outer diameter is increased by this upsetting process in a part of the direction , this processing The part where the hardened layer exists and the part where the work hardened layer does not exist are subjected to a side extrusion process in which the part where the work hardened layer does not exist is moved radially outward from the part where the work hardened layer exists. the base of the outward flange together constituting a portion where the work-hardened layer is present, the absence of the work hardening layer in the radial direction outboard portion among the axially one side of the outward flange, according to claim 1 Rolling bearing Method for producing a knitted for bearing ring member.

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