JP5494275B2 - 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. . Specifically, when making a ring member having an outward flange on the outer diameter side of one of the outer ring raceways in a double row formed on the inner peripheral surface, the surface of both outer ring raceways is formed. A manufacturing method that can effectively improve the rolling fatigue life of these outer ring raceways by exposing a clean material.

  2. Description of the Related Art Wheel bearing rolling bearing units are widely used to rotatably support braking rotating members such as automobile wheels and brake disks with respect to a suspension device. As such a wheel-supporting rolling bearing unit, an inner ring rotating type as shown in FIGS. 6 to 7 is generally used, but in some cases, an outer ring rotating type as shown in FIG. 8 is used. Things are also used.

  First, the inner ring rotation type wheel support rolling bearing unit 1 shown in FIG. 6 is for a driven wheel (a front wheel of an FR vehicle and an MR vehicle, a rear wheel of an FF vehicle), and includes an outer ring 2, a hub 3, A plurality of rolling elements 4 and 4 are provided. Of these, the outer ring 2 has two rows of outer ring raceways 5a and 5b at two positions in the axial direction of the inner peripheral surface. 6 to 8. On the other hand, the left side of FIGS.6 to 8 which is the outer side of the vehicle in the width direction is called “outside” in the axial direction. The same is applied to the outer flange 6. Further, the hub 3 has an outward flange 7 on the outer peripheral surface near the outer end in the axial direction, and double row inner ring raceways 8a and 8b at two positions in the axial direction between the intermediate portion and the inner end portion. Have. A plurality of rolling elements 4, 4 are arranged between the inner ring raceways 8a, 8b and the outer ring raceways 5a, 5b for each row, and the hub on the inner diameter side of the outer ring 2 is disposed. 3 rotations are possible. In the state of use, the outward flange 6 of the outer ring 2 is coupled and fixed to a knuckle that constitutes a suspension device, and the wheel and the braking rotary member are coupled and fixed to the outward flange 7 of the hub 3.

  Also, the inner ring rotating type wheel support rolling bearing unit 1a shown in FIG. 7 is for driving wheels (the rear wheels of FR and MR vehicles, the front wheels of FF vehicles, and all wheels of WD vehicles). In the case of the wheel-supporting rolling bearing unit 1a shown in FIG. 7, a spline hole 9 for spline engagement with the drive shaft when used is formed in the axial center portion of the hub 3a in the axial direction. doing. The basic configuration of the other parts is almost the same as that of the rolling bearing unit 1 for supporting a wheel shown in FIG.

An outer ring rotating type wheel bearing rolling bearing unit 1b shown in FIG. 8 is for a driven wheel, and includes a pair of inner rings 10, 10, a hub 11, and a plurality of rolling elements 4, 4. Prepare. Of these, the pair of inner rings 10, 10 each have a single row of inner ring raceways 8a, 8b on the outer peripheral surface, and are arranged side by side in the axial direction. The hub 11 has double-row outer ring raceways 5a and 5b at two positions in the axial direction of the inner peripheral surface, and an outward flange 7 at a portion near the outer end in the axial direction of the outer peripheral surface. Then, a plurality of rolling elements 4, 4 are arranged in each row between the outer ring raceways 5a, 5b and the inner ring raceways 8a, 8b. The hub 11 can be rotated. In the state of use, both the inner rings 10 and 10 are externally fitted and fixed to an axle provided in the suspension device, and the wheels and the braking rotating member are coupled and fixed to the outward flange 7 of the hub 11.
In the case of the rolling bearing units 1, 1 a, 1 b for supporting the wheels described above, balls are used as the rolling elements 4, 4, but the rolling bearing units for supporting the wheels for heavy vehicles are used. In some cases, a tapered roller may be used as the rolling element.

Double-row outer ring raceways 5a and 5b are arranged at two positions in the axial direction of the inner peripheral surface of the bearing ring members such as the outer ring 2 and the hub 11 constituting the wheel bearing rolling bearing units 1, 1a and 1b described above. The bearing ring member having the outward flange 6 at a position close to one axial side of the outer peripheral surface is formed by subjecting a metal material to forging and then finishing such as cutting and grinding.
Hereinafter, for a first example of such a conventional method of manufacturing a ring member, double row outer ring raceways 5a and 5b are disposed at two positions in the axial direction of the inner peripheral surface as shown in FIGS. An example of the manufacturing method of the outer ring 2 in which the outward flange 6 is formed at a position overlapping with the outer ring raceway 5a on one axial side (the upper side in FIGS. 9 to 10 will be described with reference to FIG.

In order to manufacture such an outer ring 2, first, a metal columnar raw material 12 as shown in FIG. 11A is prepared.
Then, in the first upsetting step, the raw material 12 is crushed in the axial direction to obtain a first intermediate material 13 as shown in FIG. The first intermediate material 13 has a shape such as a beer barrel or a thick disk shape in which the outer diameter of the intermediate portion in the axial direction is larger than the outer diameter of both end portions in the axial direction.
When such a first intermediate material 13 is obtained, both axial end surfaces of the first intermediate material 13 are surrounded by a rough forming die in the subsequent rough forming step. A pair of rough forming pressing punches is pressed against the center of the first intermediate material 13 to cause plastic deformation. Then, a second intermediate material 14 as shown in FIG. 11C is obtained. The second intermediate material 14 includes a pair of recesses 15a and 15b that open on both axial end surfaces, a partition wall 16 that exists between the bottoms of the recesses 15a and 15b, and one axial side of the outer peripheral surface ( And an outward flange 6 formed so as to protrude radially outward at a position close to the upper side of FIG. 11.

When such a second intermediate material 14 is obtained, both ends of the second intermediate material 14 in the axial direction are surrounded by a finish forming die in the subsequent finish forming step. Press a pair of finish forming press punches onto the surface. As a result, the partition wall 16 is crushed in the direction of reducing the thickness, and the shape of the cylindrical portion 24 existing around the partition wall 16 is changed to the shape of the outer ring 2 shown in FIGS. Get closer. And the 3rd intermediate material 17 as shown to (D) of FIG. 11 is obtained.
When such a third intermediate material 17 is obtained, in the subsequent punching step, the partition wall portion 16 of the third intermediate material 17 is punched and removed except for the outer peripheral edge portion, so that FIG. A fourth intermediate material 18 as shown in FIG.
When such a fourth intermediate material 18 is obtained, the burrs 19 remaining on the outer peripheral edge portion of the outward flange 6 of the fourth intermediate material 18 are removed in a subsequent deburring step, as shown in FIG. A fifth intermediate material 20 as shown in F) is obtained.
Then, the outer ring 2 shown in FIGS. 9 to 10 is completed by performing finishing processing such as cutting or grinding by turning or the like on each part of the fifth intermediate material 20.

  By the way, the columnar raw material 12 shown in FIG. 11 (A) is obtained by cutting a long material having a circular cross section perpendicular to the axial direction, which is extruded by a steel manufacturer, into a predetermined length. Built. The fact that the composition (cleanliness) of the raw material 12 is not uniform is described in Patent Document 1 and the like and has been conventionally known. That is, in the raw material 12, a range of 40% on the center side in the radial direction (range from the center to a radius of 40%) and a range of 20% on the outside in the radial direction (radius from the center of 80%). It is known that the degree of cleanliness is low due to the presence of a large amount of oxide-based non-metallic inclusions in the outer range). Such a low-cleanness metal material is in rolling contact with the rolling surfaces of the rolling elements 4 and 4 in the double-row outer ring raceways 5a and 5b provided on the inner peripheral surface of the outer ring 1. When exposed to a part, it becomes difficult to ensure the rolling fatigue life of the part.

  Considering these things, and taking into account variations in the distribution of oxide-based non-metallic inclusions in the raw material 12 and various variations such as pressing force generated during manufacturing operations, out of the raw material 12 In the radial direction, it exists in the range of 50% on the center side (range from the center to a radius of 50%), and in the range of 30% on the outside in the radial direction (range from the center to a radius outside 70%) It is preferable that the metal material to be exposed is not exposed to at least a portion of each of the outer ring raceways 5a and 5b where the respective rolling surfaces are in rolling contact. In other words, at least a portion of the outer ring raceways 5a and 5b where the rolling surfaces 4 and 4 are in rolling contact has a radius from the center of the raw material 12 of 50 to 70%. It is preferable to expose a metal material having a high cleanliness that exists in the range. However, when the outer ring 2 is manufactured by the above-described conventional manufacturing method, it is difficult to expose the metal material having such a high cleanliness to the outer ring raceways 5a and 5b. This point will be described below with reference to FIGS. 12 to 13 in addition to FIG. 11 described above.

  FIG. 12 shows a distribution state of the metal material in the second intermediate material 14, and FIG. 13 shows a distribution state of the metal material in the third intermediate material 17, respectively. In the process in which the first intermediate material 13 shown in FIG. 11B is plastically processed into the second intermediate material 14 shown in FIG. 11C, and further plastically processed into the third intermediate material 17 shown in FIG. The metal material constituting the intermediate materials 13 and 14 in the previous stage flows (moves) in the radial direction and the axial direction in accordance with the shape of the intermediate materials 14 and 17 in the next stage (to form this shape). The direction of the flow is greatly influenced by the presence of the outward flange 6, and many portions of the metal material pushed away from the portion corresponding to the partition wall portion 16 due to the processing of the recesses 15 a and 15 b, It flows toward the outward flange 6.

  As a result of the flow of the metal material performed in this manner, the innermost side of each of the second and third intermediate materials 14 and 17 is within the range of 50% of the raw material 12 in the center side in the radial direction. The existing center metal material 21 with a low cleanliness is present. Moreover, in the part shown by the slanted lattice surrounding this central metal material 21, the radius from the center exists in the range of 50-70% among the said raw materials 12, and the intermediate | middle with high cleanliness is high. The partial metal material 22 is present. Further, in the portion surrounding the intermediate metal material 22, the outer metal material 23 having a low cleanliness, which is present in a range of 30% of the raw material 12 in the radial direction, is present. Become.

  The third intermediate material 17 manufactured in this way is subjected to punching, deburring, finishing, cutting, and turning, which are finishing processes, so that the outer ring as shown by a chain line in FIG. 2. However, when the outer ring 2 is made in this manner, the clean intermediate metal material 22 cannot be exposed on the surfaces of the outer ring raceways 5a and 5b, as can be seen from the description of FIG. Specifically, with respect to one outer ring raceway 5a existing on the inner diameter side of the outward flange 6, the clean intermediate metal material 22 is removed, and the unclean central metal material 21 is exposed. Further, the non-clean outer portion metal material 23 is exposed on the surface of the other outer ring raceway 5b far from the outward flange 6.

  In the case of the conventional manufacturing method described above, the first intermediate material 13 having a shape like a beer barrel as shown in FIG. 11 (B) is used as shown in FIG. 11 (C) and FIG. The second intermediate material 14 formed by a positional relationship in which the partition wall portion 16 is formed on the inner diameter side of the cylindrical portion 24 existing in the radial intermediate portion, the outward flange 6 is also formed on the outer diameter side, and does not overlap with each other in the radial direction, It is formed by a rough forming process. However, when the second intermediate material 14 is formed in this manner, the second intermediate material obtained by the flow of the metal material accompanying plastic deformation from the first intermediate material 13 to the second intermediate material 14 is obtained. The distribution of the metal material in 14 is as shown in FIG. That is, a part of the central metal material 21 and the intermediate metal material 22 existing in the central portion and the radial intermediate portion of the first intermediate material 13 are radially outward toward the outward flange 6. At the same time, it also flows in the axial direction.

  Along with the flow of the metal materials 21 and 22 in each part, the clean intermediate metal material 22 is greatly stretched in the axial direction between the partition wall 16 and the outward flange 6, and the radial direction The thickness about becomes small (thin). Then, the thin metal part 21 that is not clean is present on the outer diameter side of the intermediate part metal material 22 that has become thin. In this way, the portion where the intermediate metallic material 22 becomes thin and the central metallic material 21 exists in the periphery is the portion that becomes the outer ring raceway 5a on one axial side (the upper side in FIGS. 9, 10 and 13) after completion. . On the other hand, the non-clean outer metal material 23 is still present in the portion that becomes the outer ring raceway 5b on the other side in the axial direction (the lower side in FIGS. 9, 10, and 13) after completion. In particular, the intermediate metal material 22 does not exist from the stage of the second intermediate material 14 in the portion to be the outer ring raceway 5b on the other side in the axial direction, which is located on the opposite side to the outward flange 6. It becomes. As a result, the metal distribution in the third intermediate material 17 produced by the subsequent finish forming process shown in FIGS. 11C to 11D is as shown in FIG.

  The third intermediate material 17 is subjected to the punching and deburring processes shown in (D) → (E) → (F) of FIG. 11 to obtain the fifth intermediate material 20 shown in (F). When the fifth intermediate material 20 is subjected to turning and grinding, which are finishing processes, and the inner peripheral surface portion of the cylindrical portion 24 of the fifth intermediate material 20 is scraped off, any of the outer ring raceways 5a and 5b is removed. Also, the clean intermediate metal material 22 cannot be exposed on the surface. Specifically, with respect to the surface of the outer ring raceway 5 a existing on the inner diameter side of the outward flange 6, the intermediate metal material 22 existing up to the stage of the fifth intermediate material 20 is scraped off, and the center The partial metal material 21 is exposed. On the other hand, on the surface of the outer ring raceway 5b on the side far from the outward flange 6, the outer portion metal material 23 originally present in the portion where the outer ring raceway 5b should be provided is exposed. As a result, it becomes difficult to secure a rolling fatigue life for both the outer ring raceways 5a and 5b.

  In view of such circumstances, Patent Document 1 describes the first intermediate material 13 as the fifth as shown in FIG. 14 (B) → (C) → (D) → (E) → (F). In the process of processing the intermediate material 20a, a method of forming the second intermediate material 25 having no outward flange on the outer peripheral surface is described. In the case of the second example of the conventional method of manufacturing the bearing ring member shown in FIG. 14, a pair of outer ring raceways are formed on the inner peripheral surface of the cylindrical portion 24a constituting the second intermediate material 25. A clean intermediate metal material 22 is present in a sufficient thickness dimension in the portions 5a and 5b. Next, as shown in the order of (A) → (B) → (C) in FIG. 15, a pressing punch 28, a counter punch 29, an upper die 30, a lower die 31, and an extrusion punch 32 were provided. While the cylindrical portion 24a is crushed in the axial direction by the mold apparatus, a part of the metal material constituting the cylindrical portion 24a is caused to flow radially outward to form the outward flange 6, as shown in FIG. The third intermediate material 26 shown in FIG. Further, the burrs 19 are removed from the third intermediate material 26 to obtain the fourth intermediate material 27 shown in FIG. 5E, and the partition wall 16 of the fourth intermediate material 27 is punched out. The fifth intermediate material 20a shown in FIG. Further, finishing processing such as turning and grinding is performed on the fifth intermediate material 20a to obtain an outer ring 2 having a shape indicated by a chain line in FIG.

  In the case of the manufacturing method of the second example described in Patent Document 1 and conventionally known as described above, the outer ring existing on the inner diameter side of the outward flange 6 as can be seen from FIG. Regardless of the track 5a and the outer ring track 5b existing in the part away from the outward flange 6, the clean intermediate metal material 22 can be exposed on the respective surfaces. For this reason, it is easy to ensure a rolling fatigue life in any of the outer ring raceways 5a and 5b.

  However, in the case of the second example of the conventional manufacturing method shown in FIG. 14 described above, the structure of the mold apparatus for processing the second intermediate material 25 into the third intermediate material 26 becomes complicated. The equipment cost of this mold apparatus and, in turn, the manufacturing cost of the bearing ring member such as the outer ring 2 manufactured using this mold apparatus will increase. Further, it is difficult to make the central metal material 21 sufficiently away from the inner ring raceway 5a provided on the inner circumferential surface of the outer ring 2. For this reason, depending on the manufacturing conditions, it may not be possible to prevent the unclean central metal material 21 from being exposed to the inner ring raceway 5a. As a result, it is difficult to ensure the yield, and the manufacturing cost of the outer ring 2 may increase.

JP 2008-126286 A

  In view of the circumstances as described above, the present invention provides a bearing ring member having a double row outer ring raceway on the inner circumferential surface and an outward flange on the outer diameter side of one outer ring raceway on the outer circumferential surface. The invention was invented to realize a manufacturing method that can be stably manufactured using a mold apparatus having a simple structure so that the rolling fatigue life of both outer ring raceways can be sufficiently secured.

The method of manufacturing a race ring member according to the present invention includes a double row outer ring raceway on an inner peripheral surface, and an outward flange at a portion of the outer peripheral surface where the position in the axial direction coincides with one of the outer ring raceways. Are each a manufacturing method for producing a bearing ring member, and includes an upsetting step, a rough forming step, and a finish forming step.
In this upsetting process, the first intermediate material with the outer diameter of the axial intermediate portion made larger than the outer diameter of both axial end portions is squeezed in the axial direction by crushing the metal cylindrical material. obtain.
In the rough forming step, the first intermediate material is plastically deformed to open a second intermediate portion having a pair of concave portions that are opened at both axial end surfaces and partitioned by partition walls and the outward flange. Get the material.
Further, in the finish forming step, the second intermediate material is plastically deformed to crush the partition wall in the direction of reducing the thickness dimension, and the shape of the portion other than the partition wall is changed to the shape of the bearing ring member. Get a third intermediate material close to.
In addition, regarding the bearing ring member that is the object of the manufacturing method of the present invention, the state in which the position in the axial direction coincides with one outer ring raceway has the outward flange in each of the outer ring raceways. And a portion that is in rolling contact with each other exists in the thickness range of the outward flange (a portion in the thickness direction of the outward flange exists at a radially outward position of the portion in contact with the rolling).

  In particular, in the method for manufacturing a race member of the present invention, the second intermediate material is formed in the rough forming step in a state where the outward flange and the partition wall are overlapped in the radial direction. The state in which the outward flange and the partition wall are overlapped in the radial direction is at least 1/2 or more (preferably 60% or more, more preferably 80% or more) of the thickness dimension in the axial direction of the partition wall. Is superimposed on the outward flange in the radial direction (more than half of the partition walls are present on the inner diameter side of the outward flange). In other words, a portion of the partition wall having a thickness less than ½ (preferably less than 40%, more preferably less than 20%) may be offset in the axial direction with respect to the outward flange. good. The offset amount and the direction of the offset are the positions in the axial direction of the outward flange and the portion of the outer ring raceway existing on the inner diameter side of the outward flange, in contact with the rolling surface of the rolling element. Appropriately regulated by the relationship and the pitch between the outer ring raceways of the double row. This regulation is determined by computer simulation and experiment in consideration of fluidity of the metal material constituting the intermediate material in each process. In order to satisfy the above condition, the axial thickness of the outward flange is at least 1/2 (preferably at least 60%, more preferably at least 80%) of the axial thickness of the partition wall. Of course, exceeding 100% is not preferable because the metal material flowing to the outward flange becomes excessive.)

As described above, if the outward flange and the partition wall are formed, then the one outer ring raceway is formed on one side in the axial direction of the partition wall as the partition wall is crushed in the finish molding step. Is retracted from the portion to be formed.
And the part which should become this one outer ring track is formed in the part near the outer diameter of the axial direction one side of this partition part. That is, by moving the partition wall in the axial direction, the inner diameter side of the outward flange is disposed between the inner peripheral surface of the cylindrical portion constituting the third intermediate material and the outer peripheral edge on one side of the partition wall. A portion for forming the outer ring raceway is provided. When forming the third intermediate material in this way, if necessary, the bulkhead portion is crushed in the axial direction, and at the same time, the shape and dimensions of the cylindrical portion are made of the completed ring members. Close to the shape of the cylindrical portion (processing to a shape and size slightly larger than the cylindrical portion of the completed race ring member).

According to the method of manufacturing the raceway ring member of the present invention configured as described above, the outer ring raceway in one row of the outer circumferential surface is arranged on the outer circumferential surface of the double row outer raceway in two axial positions on the inner circumference surface. A ring member having an outward flange on each side and capable of sufficiently securing the rolling fatigue life of both outer ring raceways can be manufactured at low cost.
First, the rolling fatigue life of both outer ring raceways can be ensured by exposing a clean intermediate metal material to both outer ring raceway portions.
And in the case of the manufacturing method of the bearing ring member of the present invention, the processing which uses the first intermediate material as the second intermediate material in the rough forming step is also used as the third intermediate material in the finish forming step. Both processes can be performed by a mold apparatus having a relatively simple structure in which a pair of molds are moved far and away from each other. For this reason, the installation cost for this mold apparatus can be kept low. Moreover, the non-clean center metal material in each of the intermediate materials is not exposed to any of the double-row outer ring raceways, so that the central metal material is not exposed on the surface of any outer ring raceway. I can do it. For this reason, the intermediate metal material can be stably exposed to both outer ring raceway portions, and the production cost of the race ring member can be suppressed by the yield.

Sectional drawing of a raw material thru | or a 5th intermediate material which shows one example of embodiment of the manufacturing method of the bearing ring member of this invention in process order. Sectional drawing which shows the process of processing a 1st intermediate material into a 2nd intermediate material in order. Sectional drawing which shows the distribution condition of the metal material which each existed in the center part of the raw material, the intermediate part, and the outer part in the stage of the 2nd intermediate material. Sectional drawing which shows the process of processing a 2nd intermediate material into a 3rd intermediate material in order. Sectional drawing which shows the distribution condition of the metal material which each existed in the center part of the raw material, the intermediate part, and the outer part 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. FIG. 6 is a half sectional view showing an example of a wheel bearing rolling bearing unit for an inner ring rotation type and driving wheel, which is provided with an outer ring which is a bearing ring member that is an object of the manufacturing method of the present invention. The half part sectional view showing an example of a rolling bearing unit for wheel support of an outer ring rotation type provided with a hub which is a track ring member used as a subject of a manufacturing method of the present invention. Sectional drawing of the outer ring | wheel used as the object of the manufacturing method of this invention. Similarly perspective view. Sectional drawing of a raw material thru | or a 5th intermediate material which shows the 1st example of the manufacturing method of the conventional bearing ring member in order of a process. Sectional drawing which shows the distribution condition of the metal material which each existed in the center part of the raw material, the intermediate part, and the outer part in the stage of the 2nd intermediate material. Sectional drawing which shows the distribution condition of the metal material which each existed in the center part of the raw material, the intermediate part, and the outer part in the stage of the 3rd intermediate material. Sectional drawing of a raw material thru | or a 5th intermediate material which shows the 2nd example of the manufacturing method of the conventional bearing ring member in order of a process. Sectional drawing which shows the process of processing a 2nd intermediate raw material into a 3rd intermediate raw material in order with the conventional manufacturing method.

  An example of an embodiment of the present invention will be described with reference to FIGS. The feature of this example is that the outer ring 2 having the shape shown in FIGS. 9 to 10 is manufactured with a highly clean metallic material exposed on the surfaces of the double row outer ring raceways 5a and 5b. In addition, the rough forming step for processing the first intermediate material 13 into the second intermediate material 14a and the finish forming step for processing the second intermediate material 14a into the third intermediate material 17a are devised. . The configuration of the other parts is the same as that of the first example of the conventional manufacturing method described above with reference to FIG. The first example of the conventional manufacturing method has been conventionally known, for example, as described in Patent Document 1 described above, and therefore, illustration and detailed description of the same or equivalent parts are omitted or simplified. In the following, the characteristic part of this example will be mainly described.

  Also in the case of this example, as in the case of the first example of the conventional manufacturing method described above, when the outer ring 2 is manufactured, first, as shown in FIG. A raw material 12 is prepared. And the upsetting process shown to (B)-> (B) of the figure, the rough-forming process shown to (B)-> (C), the finish-forming process shown to (C)-> (D), (D) → The first to fifth intermediate materials 13, 14a, 17a, 18a, and 20b are sequentially obtained by sequentially performing the punching process shown in (E) and the deburring process shown in (E) → (F). . After that, the outer ring 2 as shown in FIGS. 9 to 10 is completed as shown by the chain line in FIG. 5 by performing finishing such as cutting and grinding on the fifth intermediate material 20b.

  In particular, in the case of the manufacturing method of this example, unlike the case of the first example of the conventional manufacturing method described above, in the rough forming step shown in FIG. In the material 14a, the outward flange 6 and the partition wall portion 16a overlap each other with respect to the radial direction and at least 1/2 of the thickness in the axial direction of the partition wall portion 16a (1/2 or more of the partition wall portions 16a are overlapped). , Existing on the inner diameter side of the outward flange 6). In the case of this example, the thickness of the outward flange 6 and the thickness of the partition wall portion 16a are substantially the same, and the axial direction one side (the upper side in FIGS. 1 and 3) of the partition wall portion 16a. % And the second intermediate material in a state where about 70% of the axially other side (the lower side in FIGS. 1 and 3) of the outward flange 6 is overlapped in the radial direction. 14a is formed.

  In particular, in the case of this example, a mold apparatus used in the rough forming step is a relatively simple structure composed of an upper mold 33 and a lower mold 34 as shown in FIG. Of these, an upper cavity 35 having an inner surface shape that matches the outer surface shape of the portion near the inner end in the axial direction of the second intermediate material 14a is opened on the lower surface of the upper mold 33. On the other hand, on the upper surface of the lower mold 34, a lower cavity 36 having an inner surface shape corresponding to the outer surface shape of the intermediate portion in the axial direction or the portion near the outer end of the second intermediate material 14a is opened. Then, as shown in the order of (A) → (B) in FIG. 2, the first intermediate material 13 is crushed in the axial direction between the upper cavity 35 and the lower cavity 36, so that the first The intermediate material 13 is plastically deformed to obtain the second intermediate material 14a. In the actual case, the lower end surface of the lower cavity 36 is constituted by the upper end surface of the cylindrical extrusion punch 32 as in the case of the conventional structure shown in FIG. The reason for this is to facilitate removal of the second intermediate material 14a after processing from the lower cavity 36.

  In the manufacturing method of the present example, the outward flange 6 and the partition wall portion 16a are related to the axial direction of the partition wall portion 16a as described above by devising the shapes and dimensions of the upper and lower cavities 35 and 36. The second intermediate material 14a is formed so as to be ½ or more of the thickness and overlapped in the radial direction. In the case of this example, with the second intermediate material 14a obtained, the partition wall 16a and the outward flange 6 are overlapped with each other in the radial direction by about 70% of the axial thickness. ing.

  Thus, in the process of forming the second intermediate material 14a in which the partition wall portion 16a and the outward flange 6 are sufficiently overlapped in the radial direction (about 70% in this example), both concave portions are formed. The metal material present in the portions to be 15c and 15d and pushed away by a part of the upper mold 33 and the lower mold 34 flows toward the cylindrical portion 24b. Then, the axial length of the cylindrical portion 24b is expanded as compared with the axial length of the first intermediate material 13, and a part thereof flows to the outward flange 6 portion. In the case of this example, since the partition wall 16a and the outward flange 6 are sufficiently overlapped (about 70%) in the radial direction, among the metal materials that flow toward the outward flange 6 portion, The non-clean center metal material 21 flows radially outward toward the outward flange 6. Since the central metal material 21 hardly flows in the axial direction, the central metal material 21 is not so close to the portion to be the outer ring raceways 5a and 5b. On the other hand, the clean intermediate metal material 22 present in the radial intermediate portion of the raw material 12 mainly flows toward the radially outer side of the partition wall 16a as shown in FIG. Flows on both axial sides. As in the case of the first example of the conventional manufacturing method shown in FIG. 12 described above, the thickness in the radial direction is not reduced (thinned) by being greatly stretched in the axial direction.

  As described above, in the case of the manufacturing method of this example, the central metal material 21 approaches the portion to be the outer ring raceways 5a and 5b, or the intermediate metal material 22 is connected to the partition wall 16a and the outward direction. It is not greatly stretched between the flange 6 in the axial direction. The intermediate metal material 22 is in a state of being spanned in the radial direction between the partition wall portions 16 a and the outward flange 6. In this state, the intermediate metallic material 22 forms a relatively thick layer in the axially intermediate portion and the radial intermediate portion of the cylindrical portion 24b constituting the second intermediate material 14a. Of the second intermediate material 14a, the portion where the thick layer is formed becomes a double row outer ring raceway 5a, 5b (see FIGS. 9 to 10 and FIG. 5 described below) after completion. Located in the vicinity of Thus, in the case of this example, the non-clean center metal material 21 is made to flow almost only in the radial direction, and the portions near the outer diameter of the clean intermediate metal material 22 are expanded on both sides in the axial direction. . For this reason, the distribution state of the intermediate metal material 22 can be stably distributed over the entire circumference in the portions to be the outer ring raceways 5a and 5b. On the other hand, the central metal material 21 can be sufficiently separated from the portions to be the outer ring raceways 5a and 5b.

  When the second intermediate material 14a is obtained as described above, the second intermediate material 14a is plastically deformed in a mold for finish molding. Specifically, as shown in FIG. 4, a partition device 16a of the second intermediate material 14a is crushed in the axial direction using a mold device composed of an upper die 37 and a lower die 38 (thickness dimension). ). On the lower surface of the upper die 37, there is an upper cavity 39 having an inner surface shape corresponding to the outer surface shape of the portion near the inner end in the axial direction of the third intermediate material 17a, and on the upper surface of the lower die 38, the third intermediate material. The lower cavities 40 each having an inner surface shape corresponding to the outer surface shape of the axially intermediate portion or the outer end portion of 17a are opened. The lower end surface of the lower cavity 40 is also constituted by the upper end surface of the cylindrical extrusion punch.

  In the process of using the mold apparatus shown in FIG. 4 as the second intermediate material 14a as the third intermediate material 17a, the partition wall portion 16a is crushed so that the metal material of the partition wall portion 16a portion is used. Flowing radially outward, the metal material is fed into the cylindrical portion 24b, the cylindrical portion 24b is stretched, and is slightly smaller than the axial dimension of the outer ring 2 (see the chain line in FIG. 5) after completion. The cylindrical portion 24 is long. In this way, in the process of crushing the partition wall 16a and extending the cylindrical portion 24b (24), the intermediate portion that is present in the axially intermediate portion of the cylindrical portion 24b and in the radially intermediate portion. A relatively thick layer of the partial metal material 22 extends in the axial direction of the cylindrical portion 24b (24).

  In this way, in the process in which the cylindrical portion 24b (24) expands in the axial direction, a relatively thick layer of the intermediate metal material 22 is also extended in the axial direction, but even in the state where the third intermediate material 17a is obtained. As shown in FIG. 5, the intermediate metallic material 22 is formed in a relatively thick layer over the entire circumference in the axial intermediate portion of the cylindrical portion 24 and on both side portions in the axial direction of the partition wall portion 16 a. Remains. That is, as can be seen by comparing FIG. 3 and FIG. 5, in the process of crushing the partition wall 16a, a substantial portion of the intermediate metal material 22 existing near the outer diameter of the partition wall 16a is The cylindrical portion 24 is fed (supplemented) into the axially opposite side portions of the partition wall portion 16a at the intermediate portion in the axial direction. Therefore, the outer ring raceways 5a and 5b are formed in the cylindrical portion 24 regardless of the extension of the cylindrical portion 24b of the second intermediate material 14a to the cylindrical portion 24 of the third intermediate material 17a. The thickness in the radial direction of the intermediate metal material 22 existing in the portion to be secured can be sufficiently secured.

  That is, with respect to the portion where the outer ring raceway 5a on one side in the axial direction is to be provided, a sufficient thickness can be obtained by retracting one side (the upper surface in FIGS. A layer of the intermediate metal material 22 having dimensions is formed. On the other hand, with respect to the portion where the outer ring raceway 5b on the other side in the axial direction is to be provided, the outer surface of the partition wall 16a (the lower surface in FIGS. 1 to 5) is closer to the outer diameter as the recess 15d is deepened. As the existing intermediate metal material 22 is extruded into the cylindrical portion 24, a layer of the intermediate metal material 22 having a sufficient thickness dimension is formed. In this case, the movement of the intermediate metal material 22 to be the outer ring raceways 5a and 5b is also relatively simple (basically, the outer surfaces of the pair of press punches). It will only move along the flow). Therefore, the distribution state of the intermediate metal material 22 as shown in FIG. 5 can be realized stably.

  When the third intermediate material 17a as described above is obtained, in the subsequent punching step, the partition wall portion 16a of the third intermediate material 17a is removed from the outside as shown in (D) → (E) of FIG. The fourth intermediate material 18a is obtained by punching and removing except for the peripheral portion. Next, as shown in FIGS. 1E to 1F, the burrs 19 remaining on the outer peripheral edge of the outward flange 6 of the fourth intermediate material 18a are removed to obtain a fifth intermediate material 20b. After that, each part of the fifth intermediate material 20b is subjected to a finishing process such as a cutting process or a grinding process by turning or the like, so that an outer ring 2 as shown by a chain line in FIG. 5 is obtained. As is clear from FIG. 5, the clean intermediate metal material 22 is formed on the surface of the double row outer ring raceways 5a and 5b provided on the inner peripheral surface of the outer ring 2 after the completion of any outer ring raceways 5a and 5b. Is exposed. For this reason, it is easy to secure the rolling fatigue life of both the outer ring raceways 5a and 5b.

According to the manufacturing method of the outer ring 2 of this example configured as described above, one outer ring raceway 5a of the double row outer ring raceways 5a and 5b exists on the inner diameter side of the outward flange 6 formed on the outer peripheral surface. The outer ring 2 can be manufactured at a low cost by making the distribution of the metal material easy to sufficiently ensure the rolling fatigue life of the both outer ring raceways 5a and 5b.
First, the rolling fatigue life of the outer ring raceways 5a and 5b can be ensured by exposing the intermediate metal material 22 to both the outer ring raceways 5a and 5b. As described above, since the intermediate metal material 22 is a relatively clean metal material with a low probability of the presence of oxide-based non-metallic inclusions, the intermediate metal material 22 is exposed. Both the outer ring raceways 5a and 5b are unlikely to be damaged such as surface peeling, and it is easy to ensure the rolling fatigue life.

  And in the case of the manufacturing method of the outer ring | wheel 2 of this example, when the said 1st intermediate material 13 is used as said 2nd intermediate material 14a in the rough forming process of (B)-> (C) of FIG. The central metal material can be made to flow only outward in the radial direction so as not to approach the portions to be the outer ring raceways 5a and 5b. On the other hand, the clean intermediate metal material 22 is distributed with a sufficient thickness in the portions to be the outer ring raceways 5a and 5b. Furthermore, even when the second intermediate material 14a is the third intermediate material 17a shown in FIG. 5 in the finish molding step (C) → (D) in FIG. 1, the clean intermediate metal material 22 is The outer ring raceways 5a and 5b are distributed with sufficient thickness on the portions to be the outer raceways 5a and 5b. For this reason, the intermediate metal material 22 can be stably exposed to both the outer ring raceways 5a and 5b, and the production cost of the outer ring 2 can be suppressed by improving the yield.

  Furthermore, in the case of the manufacturing method of this example, the mold apparatus used in each process has a relatively simple structure as compared with the case of the second example of the conventional manufacturing method shown in FIG. Can be used. For this reason, it becomes possible to keep the manufacturing cost of the mold apparatus low, and the equipment cost can be kept low compared to the case of the second example of the conventional manufacturing method.

  The present invention is not limited to the manufacture of the outer ring for constituting the inner ring rotating type wheel support rolling bearing unit as shown in FIGS. 6 to 7 described above, but the outer ring rotating type as shown in FIG. 8 described above. The present invention can also be applied to the manufacture of a hub that constitutes a wheel bearing rolling bearing unit.

DESCRIPTION OF SYMBOLS 1, 1a, 1b Wheel support rolling bearing unit 2 Outer ring 3, 3a Hub 4 Rolling element 5a, 5b Outer ring raceway 6 Outer flange 7 Outward flange 8a, 8b Inner ring raceway 9 Spline hole 10 Inner ring 11 Hub 12 Raw material 13 First intermediate Material 14, 14a Second intermediate material 15a, 15b, 15c, 15d Recess 16, 16a Bulkhead 17, 17a Third intermediate material 18, 18a Fourth intermediate material 19 Burr 20, 20a, 20b Fifth intermediate material 21 Center metal Material 22 Intermediate metal material 23 Outer metal material 24, 24a, 24b Cylindrical portion 25 Second intermediate material 26 Third intermediate material 27 Fourth intermediate material 28 Press punch 29 Counter punch 30 Upper die 31 Lower die 32 Extrusion punch 33 Upper mold 34 Lower mold 35 Upper cavity 36 Lower cavity 3 Upper mold 38 lower mold 39 upper cavity 40 below the cavity

Claims (2)

  In order to make a double-row outer ring raceway on the inner peripheral surface, and an outer ring member having an outward flange at a portion of the outer peripheral surface where the position in the axial direction coincides with one outer ring raceway of these two outer ring raceways, An upsetting step of obtaining a first intermediate material in which the outer diameter of the axial intermediate portion is larger than the outer diameter of both axial end portions by crushing a metal column-shaped raw material in the axial direction, A rough forming step of obtaining a second intermediate material having a pair of recesses and openings outwardly opened at both axial end surfaces and partitioned by a partition wall and the outward flange by plastically deforming one intermediate material; The second intermediate material is plastically deformed to crush the partition wall in the direction of reducing the thickness dimension, and finish to obtain a third intermediate material in which the shape of the part other than the partition wall portion is close to the shape of the bearing ring member Bearing ring with molding process In the material manufacturing method, the second intermediate material is formed in the rough forming step in a state where the outward flange and the partition wall are radially overlapped, and then the partition wall is formed in the finish forming step. As it is crushed, the one axial surface of the partition wall is retracted from the portion where the one outer ring raceway should be formed, and the one outer ring raceway A method of manufacturing a bearing ring member, wherein a portion to be formed is formed.   When the third intermediate material is formed, the partition wall is crushed in the axial direction, and at the same time, the shape and dimensions of the cylindrical portion existing around the pair of recesses are adjusted to The method for manufacturing a bearing ring member according to claim 1, wherein the outer ring raceway of the double row is arranged on the peripheral surface and the outward flange is provided on the outer peripheral surface, respectively, to approach the shape of the cylindrical portion.

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