JP5182144B2 - Method for manufacturing bearing ring member - Google Patents

Description

  The present invention relates to an improvement in a manufacturing method of a bearing ring member constituting a wheel bearing rolling bearing unit, which is used for rotatably supporting a braking rotary member such as a vehicle wheel and a brake disk with respect to a suspension device. . The bearing ring that is the object of the manufacturing method of the present invention is a back-combined double-row outer ring raceway at two axial positions on the inner peripheral surface and an outward flange on the outer peripheral surface. Such a ring member has a state in which the wheel is supported and fixed when the outer ring coupled to the suspension device is the outer ring rotating type when the wheel bearing rolling bearing unit is the inner ring rotating type. Hubs rotating with the wheels correspond to each.

  2. Description of the Related Art A wheel bearing rolling bearing unit is widely used to rotatably support a wheel constituting a wheel of an automobile and a disk or drum which is a rotating member for braking on a knuckle constituting a suspension device. As such a wheel-supporting rolling bearing unit, the inner ring rotating type shown in FIG. 4 is generally used, but in some cases, the outer ring rotating type as shown in FIG. 5 is also used. Has been.

  First, the wheel support rolling bearing unit 1 for the inner ring rotating type driven wheel (the front wheel of the FR vehicle and the MR vehicle, the rear wheel of the FF vehicle) shown in FIG. 4 has a hub 3 on the inner diameter side of the outer ring 2. A plurality of rolling elements 4 and 4 are rotatably supported. In the use state, the outer ring 2 is coupled and fixed to the knuckle, and the wheel and the brake rotating member are supported and fixed to the hub 3. For this purpose, double-row outer ring raceways 5 and 5 are formed at two positions on the inner peripheral surface of the outer ring 2, and attachment portions 6 that are outward flanges described in the claims are formed on the outer peripheral surface, respectively. Yes. On the other hand, on the outer peripheral surface of the hub 3, a support flange 7 for supporting and fixing the wheel and the rotating member for braking is provided on an outer end portion projecting outward in the axial direction from the outer ring 2. Or the inner ring raceways 8 and 8 of the double row are formed in the part near an inner end, respectively. A plurality of rolling elements 4, 4 are arranged for each row between the inner ring raceways 8, 8 in both rows and the outer ring raceways 5, 5 in both rows, and the inner diameter side of the outer race 2 is arranged. The hub 3 can be freely rotated.

  Further, the outer ring rotating type wheel bearing rolling bearing unit 1a shown in FIG. 5 includes a plurality of hubs 10 around a pair of inner rings 9, 9 having inner ring raceways 8, 8 formed on the outer peripheral surfaces thereof. The rolling elements 4 and 4 are rotatably supported. In use, both the inner rings 9, 9 are externally fitted and fixed to an axle provided in the suspension device, and the wheel and the braking rotating member are supported and fixed to the hub 10. For this purpose, double-row outer ring raceways 5 and 5 are provided at two positions on the inner peripheral surface of the hub 10, and support flanges 7 a that are outward flanges described in the claims are provided at axially outer portions of the outer peripheral surface. , Each formed. A plurality of rolling elements 4, 4 are arranged for each row between the inner ring raceways 8, 8 in both rows and the outer ring raceways 5, 5 in both rows. The hub 10 can be freely rotated on the outer diameter side. In the illustrated example, balls are shown as the rolling elements 4, 4. However, in the case of a rolling bearing unit for supporting a wheel for a heavy vehicle, a tapered roller may be used as the rolling element. Furthermore, as shown in FIG. 6, a wheel for driving wheels (the rear wheels of FR and MR vehicles, the front wheels of FF vehicles, and all wheels of 4WD vehicles) incorporating a hub 3a having a spline hole 11 at the center. The supporting rolling bearing unit 1b is also widely known.

  For example, the inner circumference such as the outer rings 2, 2a constituting the wheel support rolling bearing units 1, 1b shown in FIGS. 4 and 6, or the hub 3a constituting the wheel support rolling bearing unit 1a shown in FIG. A ring member having double-row outer ring raceways at two positions in the axial direction of the surface and an outward flange on the outer peripheral surface is formed by combining forging, cutting, and grinding. In addition, as a material for producing such a ring member, a cylindrical material made by cutting a long material having a circular cross section into a predetermined length, which is extruded by a steel manufacturer, is used. It is known that the composition (cleanliness) of the columnar material obtained in this way is not uniform, and the cleanliness of the metal material existing in the portion near the center and the portion near the outer peripheral surface is low. When the metal material with low cleanliness is exposed to a portion of the raceway surface provided on the peripheral surface of the raceway member, particularly where the rolling surface of the rolling element is in contact with the rolling contact, the rolling fatigue life of this portion is reduced. It is also known that it will be difficult to secure.

  Considering these things, and taking into account variations in the distribution of oxides and non-metallic inclusions in the material, as well as various variations (such as pressing force) that occur during manufacturing operations, There is a manufacturing method for preventing the metal material existing in the range of 50% and in the range of 30% of the material from the outer diameter from being exposed to at least the part of the raceway where the rolling surface is in rolling contact. Are conventionally known, for example, as described in Patent Documents 1 to 4. In the known manufacturing methods described in each of these patent documents, by devising the processing procedure of the material, at least the rolling surface of the raceway surface is in contact with the rolling contact with the material from the center. Expose clean metallic material present in the intermediate cylindrical portion with a radius in the range of 50-70%.

For example, as shown in FIG. 7, the outer ring 2 is formed by forming double rows of outer ring raceways 5 and 5 at two positions on the inner peripheral surface and an outward flange-shaped mounting portion 6 on the outer peripheral surface. A process as shown in FIG.
In the case of this conventional manufacturing method, first, the material 12 is subjected to an upsetting process for crushing the columnar material 12 in the axial direction as shown in FIG. As shown in B), a first intermediate material 13 having a beer barrel shape in which the outer diameter of the intermediate portion in the axial direction is larger than the outer diameters of both end portions in the axial direction.
Thereafter, a rough forming process is performed in which a pair of rough forming dies are pressed on both axial end surfaces of the first intermediate material 13 with a rough forming die disposed around the first intermediate material 13. . Then, the first intermediate material 13 is plastically deformed to form a second intermediate material 14 as shown in FIG. The second intermediate material 14 has a pair of recesses 15a and 15b that are open at both axial end faces, a partition plate part 16 that partitions the bottoms of both recesses 15a and 15b, and an axially intermediate part on the outer peripheral surface. And a support flange 7 formed so as to protrude outward in the direction.

Next, a finishing process is performed in which a pair of finish molding dies are pressed on both end surfaces in the axial direction of the second intermediate material 14 and a finish molding die is disposed around the second intermediate material 14. . In this finishing process, the thickness dimensions of the partition plate portion 16 and the support flange 7 are reduced, and the shapes and dimensions of both the inner and outer peripheral surfaces of the cylindrical portion 18 are adjusted to obtain a first shape as shown in FIG. Three intermediate materials 17 are used.
Next, the partition plate portion 16 of the third intermediate material 17 is punched and removed except for a portion closer to the outer diameter, thereby forming a fourth intermediate material 19 as shown in FIG.
Further, the fourth intermediate material 19 is deburred to remove the burrs 20 remaining on the outer peripheral edge of the support flange 7 to obtain a fifth intermediate material 21 as shown in FIG. . Finally, each part is subjected to a finishing process such as a cutting process or a grinding process by turning or the like to obtain an outer ring 2 as shown in FIG.

FIG. 9 shows a distribution state of the metal material in the third intermediate material 17 produced in the steps (A) → (B) → (C) → (D) in FIG. 8. On the innermost diameter side, there is an unclean central metal material 22 that exists in the range of 50% of the central portion of the material 12. Further, in the portion surrounded by the slanted lattice in FIG. 9 surrounding the central metal material 22, the clean intermediate portion existing in the intermediate cylindrical portion whose radius from the center is in the range of 50 to 70%. Metal material 23 is present. Further, in the portion surrounding the intermediate metal material 23, there is an unclean outer diameter metal material 24 that exists in the range of 30% closer to the outer diameter of the material. A chain line in FIG. 9 indicates the outer ring 2 that is manufactured by finishing the third intermediate material 17 such as cutting and grinding. And the outer ring 2 of the chain line showing the shape position, as seen from the distribution of each metal material 22 to 24, in such a process shown in FIG. 8 described above, if make the outer ring 2, such as shown in FIG. 7, The clean metal material 23 existing in the intermediate cylindrical portion can be exposed to the double row outer ring raceways 5 and 5 formed on the inner peripheral surface of the outer ring 2.

  However, as shown in FIG. 10, the outer ring 2a in which the distance between the double-row outer ring raceways 5 and 5 is narrow (the pitch between the rows is short) by the manufacturing method as shown in FIG. Difficult when considering lifetime. That is, as apparent from the distribution of the intermediate metal material 23 shown by the oblique lattice in FIG. 9, the rolling elements 4 and 4 (FIGS. 4 to 6) of the surfaces of the outer ring raceways 5 and 5 are obtained. In order to expose the intermediate part metal material 23 to the part that is in rolling contact with the reference part), it is necessary to move the intermediate part metal material 23 to the parts to be the outer ring raceways 5 and 5. However, when the manufacturing method shown in FIG. 8 is applied to the processing of the outer ring 2a having a short pitch between rows as shown in FIG. 10, the clean intermediate metal material 23 as shown in FIG. However, it does not sufficiently move to the portion that should become the outer ring raceways 5 and 5.

  On the other hand, the amount of compression from the second intermediate material 14 to the third intermediate material 17 in the step shown in FIG. 8 (C) → (D) is increased, and as shown in FIG. If the partition plate portion 16a of the three intermediate material 17a is sufficiently thin (for example, about 4 mm in the case of an outer ring constituting a wheel bearing rolling bearing unit for a general passenger car), as shown in FIG. The intermediate metal material 23 can be sufficiently moved to the portions to be the outer ring raceways 5 and 5. However, as the partition plate portion 16a of the third intermediate material 17a is made thinner, the surface pressure applied to the mold when the second intermediate material 14 is processed into the third intermediate material 17 becomes higher. The resulting stress increases. FIG. 13 shows an example of the relationship between the thickness (horizontal axis) of the partition plate portion after processing and the surface pressure applied to the mold during processing. Note that the thickness of the partition plate portion (at the stage of the second intermediate material 14) before processing is the same (12 mm). As is apparent from FIG. 13, reducing the overall thickness of the partition plate portion 16a as in the case of the third intermediate material 17a increases the load on the mold and shortens the life of the mold. Because it is extremely short, it cannot be adopted when considering mass production. A practical value of the thickness of the partition plate is about 7 to 8 mm.

JP 2008-126286 A JP 2008-128256 A JP 2008-173677 A JP 2008-188612 A

  In view of the circumstances as described above, the present invention can ensure the durability of the mold by suppressing the stress generated in the mold at the time of processing, and moreover the double row existing on the inner peripheral surface of the outer ring with a short pitch between rows. The present invention has been invented to realize a method of manufacturing a ring member that can expose a clean metal material to the outer ring raceway.

The method of manufacturing a bearing ring member according to the present invention produces a bearing ring member provided with a pair of rear combination outer ring raceways at two axial positions on the inner peripheral surface of the cylindrical portion and an outward flange on the outer peripheral surface. Use for this purpose.
In such a method of manufacturing the race ring member of the present invention, first, a circle made of a metal material in which a clean intermediate metal material is present in an intermediate cylindrical portion whose radius from the center is in the range of 50 to 70%. By subjecting the columnar material to an upsetting process that crushes it in the axial direction, a first intermediate material in which the outer diameter of the axially intermediate portion is larger than the outer diameters of both axial end portions is made from this material.
Next, the first intermediate material is plastically deformed by subjecting the first intermediate material to rough forming. This rough forming process is performed by pressing a pair of first dies on both axial end surfaces of the first intermediate material in a state where a rough forming die is disposed around the first intermediate material, or by roughing. The molding die is omitted, and the first intermediate material is pressed between a pair of molds. And it formed in the state which protrudes to the radial direction outward in the axial direction intermediate part of an outer peripheral surface, and the 1st partition plate part which partitions off a pair of recessed part opened to both axial direction both end surfaces, and the bottom parts of these both recessed parts The second intermediate material is provided with the outward flange.
Next, at least a portion near the outer diameter of the first partition plate portion of the second intermediate material is pushed in the axial direction by a pair of second dies provided with a relief recess in the central portion of at least one tip surface. By crushing , the intermediate metal material is moved to the portion to be the outer ring raceways, and surplus material generated by the crushing is moved to the escape recess. And it is set as the 3rd intermediate material provided with the 2nd partition plate part whose thickness of a center part is large compared with the thickness of the part near an outer diameter.
Next, the second partition plate portion is punched and removed at a portion having a small thickness near the outer diameter to form a cylindrical fourth intermediate material having the outer flange on the outer peripheral surface.
Further, by finishing the fourth intermediate material to form the raceway ring member, the intermediate metal material is exposed to the outer raceway portions .

  In the case of the method of manufacturing the bearing ring member of the present invention configured as described above, in the process of processing the first partition plate portion into the second partition plate portion, By sufficiently reducing the thickness dimension, the clean intermediate metal material can be sufficiently moved to the portion to be the outer ring raceway. As a result, a clean metal material is exposed on the double row outer ring raceway existing on the inner peripheral surface of the outer ring with a short pitch between rows, and the rolling fatigue life of these outer ring raceways can be ensured.

  Further, in the process of processing the first partition plate portion into the second partition plate portion as described above, the central portion of both the partition plate portions is the presence of the relief recess existing in the center portion of the tip surface of the second mold. It will not be crushed based on it. In addition, the surplus generated by the crushing of the first partition plate portion at the end surface outer diameter portion of both the second molds is directed radially inward toward the escape recess of the second mold. Move to. Along with this movement, the force (surface pressure) required to crush (shrink the thickness dimension) the first partition plate portion or the outer diameter portion of the second partition plate portion in the axial direction is kept small. It is done. For this reason, it is possible to suppress the stress generated in the mold during processing and to ensure the durability of the mold.

Sectional drawing of the raw material thru | or 5th intermediate material which shows one example of embodiment of the manufacturing method of the bearing ring member of this invention in order of a process. Sectional drawing which shows the implementation condition of the finish molding process which processes a 2nd intermediate material into a 3rd intermediate material. Sectional drawing which shows the distribution condition of a center part, an intermediate part, an outer diameter part, and each metal material in the stage of the 3rd intermediate material. Sectional drawing which shows an example of the wheel bearing rolling bearing unit for inner ring rotation type and a driven wheel provided with the outer ring | wheel which is the bearing ring member used as the object of the manufacturing method of this invention. Sectional drawing which shows an example of the rolling bearing unit for wheel support of an outer ring | wheel rotation type provided with the hub which is the bearing ring member used as the object of the manufacturing method of this invention. Sectional drawing which shows an example of the wheel bearing rolling bearing unit for inner-wheel rotation type and drive wheels provided with the outer ring used as the object of the manufacturing method of this invention. Sectional drawing of the outer ring | wheel which can be made with the conventional manufacturing method. Sectional drawing of the raw material thru | or 5th intermediate material which shows one example of the conventional manufacturing method in order of a process. Sectional drawing which shows the distribution condition of a center part, an intermediate part, an outer diameter part, and each metal material in the stage of the 3rd intermediate material. Sectional drawing which shows an example of the outer ring | wheel with a short pitch between rows of an outer ring | wheel track | truck with which it is difficult to manufacture a quality thing with the conventional manufacturing method. Sectional drawing which shows the distribution state of a center part, an intermediate part, an outer diameter part, and each metal material in the step of the 3rd intermediate material obtained in the process of manufacturing the outer ring | wheel shown in FIG. 10 with the conventional manufacturing method. When the outer ring shown in FIG. 10 is manufactured, the center portion, the intermediate portion, the outer diameter portion, and the metal materials in the state where the partition plate portion is sufficiently crushed are obtained in order to improve the distribution of the intermediate portion metal material. Sectional drawing which shows a distribution condition. The diagram which shows the influence which the amount of crushing of a partition board part has on the magnitude | size of the stress which arises in a metal mold | die.

  An example of an embodiment of the present invention will be described with reference to FIGS. In this example, the outer ring 2a in which the distance between the double-row outer ring raceways 5 and 5 is narrow (the pitch between the rows is short) as shown in FIG. It is intended to expose the clean intermediate metal material 23 to both the outer ring raceways 5 and 5 while suppressing the stress generated in the molds 25a and 25b. Such a feature of the method of manufacturing the bearing ring member of this example is used in the process of processing the second intermediate material 14 shown in FIG. 1C into the third intermediate material 17b shown in FIG. It is in the shape of both the molds 25a and 25b. Since the configuration of the other parts is the same as that of the conventional method described above with reference to FIG. 8, the overlapping description will be omitted or simplified, and the following description will focus on the features of the present invention.

  The second intermediate material 14 shown in FIG. 2C, which is made from the cylindrical material 12 shown in FIG. 1A through the first intermediate material 13 shown in FIG. 1B, is shown in FIG. Similarly, each of the pair of molds (upper mold and lower mold) 25a and 25b, each corresponding to the second mold described in the claims, is strongly sandwiched and plastically deformed, The third intermediate material 17b shown in FIG. The molds 25a and 25b have a shape corresponding to the shape of the surface of the third intermediate material 17b in the portion excluding the central portion of the mutually facing surfaces (the size is the same and the concavities and convexities are reversed). Finishing recesses 26a and 26b having the above are provided. In addition, both the molds 25a and 25b are provided with relief recesses 27 and 27, which are characteristic of the method of manufacturing the bearing ring member of the present invention, in the center of the opposing surfaces.

  In order to use the second intermediate material 14 as the third intermediate material 17b by the two molds 25a and 25b each having such relief recesses 27 and 27, the second intermediate material 14 is used as the both metal molds. The molds 25a and 25b are strongly clamped. Then, while crushing the second intermediate material 14, the shapes of the inner surfaces of the both finish forming recesses 26 a and 26 b are transferred to the surface of the second intermediate material 14. As a result, the second intermediate material 14 is processed into the third intermediate material 17b. In this process, a portion near the outer diameter of the partition plate portion 16 provided at the center portion of the second intermediate material 14 is caused by the peripheral portions of the both escape recesses 27 and 27 in the molds 25a and 25b. It is crushed. Of the partition plate portion 16, the portion facing both the escape recesses 27, 27 is not crushed. Then, when the thickness dimension of the portion near the outer diameter of the partition plate portion 16 is sufficiently reduced, the clean intermediate metal material 23 should become the double row outer ring raceways 5 and 5 as shown in FIG. Move enough to the part.

  Further, the surplus generated by crushing the second intermediate material 14 moves to the support flange 7 side and becomes a burr 20 at the outer peripheral edge portion of the support flange 7, and the radial direction of the partition plate portion 16. It moves to the center side and swells at the two escape recesses 27 and 27. For this reason, the partition plate portion 16b of the third intermediate material 17b obtained in the process of carrying out the present invention has the smallest thickness near the outer diameter, and the thickness of the portion adjacent to the inner diameter side of the outer diameter closer portion. Is the largest, and the thickness of the center is an intermediate value. As described above, in the case of the present invention, in order to move the clean intermediate metal material 23 to the portions to be the outer ring raceways 5 and 5, the partition plate portion 16 of the second intermediate material 14 is moved. Only the portion near the outer diameter of the partition plate portion 16 is made to sufficiently reduce the thickness, and surplus portions generated by crushing the portion near the outer diameter are directed toward both the escape recesses 27 and 27, and the inner diameter side. To move to. For this reason, even the relatively small force (pressure) can crush the portion near the outer diameter of the partition plate portion 16 to a sufficiently small thickness.

  The third intermediate material 17b shown in FIG. 1 (D) and FIG. 3 thus obtained is punched and removed from the partition plate portion 16b except for the outermost diameter portion. E) The fourth intermediate material 19 as shown in FIG. 1 is further deburred to form the fifth intermediate material 21a as shown in FIG. 1 (F), and then each part is subjected to cutting or grinding by turning or the like. Thus, the outer ring 2a as shown in FIG. 10 is obtained.

  According to the method for manufacturing the race ring member of the present invention as described above, as is clear from FIG. 3, the clean intermediate metal material 23 can be sufficiently moved to the portions to be the outer race races 5 and 5. Thus, the intermediate metal material 23 can be exposed at a portion of the outer ring raceways 5 and 5 that is in rolling contact with the rolling element. Further, the rolling fatigue life of both the outer ring raceways 5 and 5 can be secured, and the durability of the wheel bearing rolling bearing unit incorporating the outer ring 2a can be secured. In addition, the force required to sufficiently reduce the thickness of the partition plate portion 16 of the second intermediate material 14 is kept low so that the intermediate metal material 23 is moved to the portions to be the outer ring raceways 5 and 5. Therefore, in the process of processing the second intermediate material 14 into the third intermediate material 17b, the stress generated in the molds 25a and 25b can be kept low. As a result, the durability of both the molds 25a and 25b can be ensured, and the mass production of the bearing ring member such as the outer ring 2a having a short inter-pitch pitch and sufficient durability can be achieved while suppressing the cost. .

  When carrying out the present invention, it is sufficient that the relief recess is provided at the center of the front end surface of at least one second mold. However, in order to move the metal material symmetrically with respect to the axial direction, it is preferable to provide relief recesses on both front end surfaces of the pair of second molds as in the illustrated example.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Wheel support rolling bearing unit 2, 2a Outer ring 3, 3a Hub 4 Rolling body 5 Outer ring raceway 6 Mounting part 7, 7a Support flange 8 Inner ring raceway 9 Inner ring 10 Hub 11 Spline hole 12 Material 13 First intermediate material 14 Second intermediate material 15a, 15b Recess 16, 16, a, 16b Partition plate portion 17, 17a, 17b Third intermediate material 18 Cylindrical portion 19 Fourth intermediate material 20 Burr 21, 21a Fifth intermediate material 22 Center metal material 23 Intermediate Part metal material 24 Outer diameter part metal material 25a, 25b Mold 26a, 26b Finish molding recess 27 Escape recess

Claims (1)

To make a ring member with a pair of backside outer ring raceways at the two axial positions on the inner peripheral surface of the cylindrical portion and an outward flange on the outer peripheral surface, the radius from the center is 50 to 70%. By applying upsetting processing to crush in the axial direction to a cylindrical material made of metal with a clean intermediate metal material present in the intermediate cylindrical part that is in the range of A first intermediate material whose outer diameter is larger than the outer diameters at both axial ends, and then plastically deforming the first intermediate material to form a pair of recesses that open at both axial end surfaces, A second intermediate material comprising a first partition plate part for partitioning the bottoms of the recesses and the outward flange formed in a state of projecting radially outward at an axially intermediate part of the outer peripheral surface, and then at least one of them A pair of second molds provided with a relief recess in the center of the tip surface More, at least the outer径寄Ri portion of the first partition plate portion of the second intermediate material By crushing in the axial direction, moves the said intermediate part metallic material into the portion to be the outer ring raceways, After moving the surplus generated with this crushing to the escape recess, as a third intermediate material provided with a second partition plate portion with a thicker central portion than the outer diameter portion. The second partition plate portion is punched and removed at a portion having a small thickness near the outer diameter to form a cylindrical fourth intermediate material having the outward flange on the outer peripheral surface. A method of manufacturing a bearing ring member, wherein the intermediate metal material is exposed to the upper outer ring raceway portion by finishing the bearing ring member.

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