JP2008126286A - Method for manufacturing bearing ring member - Google Patents

Abstract

An improved manufacturing method of a bearing ring member such as an outer ring 2 having a mounting portion 6 on an outer peripheral surface and double-row outer ring raceways 5 and 5 on an inner peripheral surface. Ensure fatigue life.
A first upsetting process of (A) → (B), a front / rear pushing process of (B) → (C), a second upsetting process of (C) → (D), The material 16 is processed into the fifth intermediate material 25 through the deburring step (D) → (E) and the punching step shown in (E) → (F). In the front-rear extrusion process, the second intermediate material 22 is obtained in which the first and second circular concave portions 26 and 27 are partitioned by the partition wall portion 28. In this state, the metal material 13 in the radially intermediate portion among the metal materials constituting the material 16 is present in the portions where the outer ring raceways 5 and 5 are to be formed. Further, in the second upsetting step, the third intermediate material 23 is obtained by forming the mounting portion 6 without changing the inner surface shape of the first and second circular concave portions 26 and 27.
[Selection] Figure 4

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 which is the object of the manufacturing method of the present invention is provided with double-row outer ring raceways at two axial positions on the inner peripheral surface and outward flanges 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. In addition, regardless of whether the race ring member is an outer ring or a hub, in the case of a race ring member that is an object of the manufacturing method of the present invention, the position of the outward flange with respect to the axial direction of the race ring is It is a condition that at least a part of the outward flange portion in the thickness direction exists between the center positions of the outer ring raceways. In addition, the center position of these outer ring raceways means the center position of the contact surface (contact ellipse when the rolling body is a ball) between these outer ring raceways and the rolling element.

  In order 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, a wheel bearing rolling bearing unit is widely used. As such a wheel-supporting rolling bearing unit, the inner ring rotating type as shown in FIG. 7 is generally used, but in some cases, the outer ring rotating type as shown in FIG. 8 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 MR vehicle, the rear wheel of the FF vehicle) shown in FIG. 7 includes a plurality of hubs 3 on the inner diameter side of the outer ring 2. The 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, the double-row outer ring raceways 5 and 5 are arranged at two positions on the inner peripheral surface of the outer ring 2 at a part of the outer peripheral surface slightly inwardly in the axial direction from the central part in the axial direction. Means the side which is the center side in the width direction of the vehicle body in the use state, and is the upper side of FIGS. , 11, and the left side of FIGS. 7 to 9 are referred to as outside in the axial direction. The same applies to the entire specification.) Forming. 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 support rolling bearing unit 1a shown in FIG. 8 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.

  A bearing ring member provided with two rows of outer ring raceways at two axial positions on the inner peripheral surface and outer flanges on the outer peripheral surface, such as the outer ring 2 constituting the wheel bearing rolling bearing unit 1 shown in FIG. Is made by combining forging, cutting and grinding. For example, in Patent Document 1, as shown in FIG. 9, an outer ring 2a for a driving wheel and an inner ring rotating type wheel support rolling bearing unit 1b, and a hub that forms a hub 3a in combination with the inner ring 9a. The processing method of the main body 11 is described. That is, the hub body 11 is forged into a finished product by a process as shown in FIG. 10A and the outer ring 2a is forged into a material as shown in FIG. 10B. The intermediate material has a close shape. Then, the intermediate material is subjected to necessary cutting and grinding to form the outer ring 2a or the hub body 11.

  By the way, the material for making a bearing ring member for a wheel bearing rolling bearing unit is a cylindrical shape made by cutting a long material with a circular cross section into a predetermined length extruded by a steel manufacturer. Use things. It has been conventionally known that the composition (cleanliness) of the columnar material obtained in this way is not uniform, as described in Patent Document 2. That is, in the range of 40% of the central portion of the material (a columnar portion near the center from the center to 40% of the radius), non-metallic inclusions are likely to be present, as described in Patent Document 2, etc. Conventionally known. In addition, the cleanliness of the range of 20% closer to the outer diameter of the material (cylindrical portion existing on the outer peripheral surface side than 80% of the radius from the center) is due to the presence of oxides and non-metallic inclusions. Is known to be low. Even if the metal material is present near the center or near the outer peripheral surface, the metal material with low cleanliness is the rolling surface of the rolling element, particularly among the raceway surfaces provided on the peripheral surface of the raceway ring member. If the surface is exposed to a portion that is in rolling contact, it will be difficult to ensure the rolling fatigue life of this portion.

  In consideration of these things, and taking into account variations in the distribution of oxides and non-metallic inclusions in the material and various variations (such as pressing force) that occur during manufacturing operations, the central portion of the material is 50%. It is preferable that the metal material existing in the range of 30% and the outer diameter of the material in the range of 30% is not exposed to at least the portion of the raceway where the rolling surface is in rolling contact. In other words, a metal material existing in an intermediate cylindrical portion having a radius from the center of 50 to 70% of the above-mentioned material is a portion of the raceway surface where the rolling contact surface is in rolling contact. It is preferable to expose.

  However, as shown in the manufacturing method of the present invention, two rows of outer ring raceways are provided at two axial positions on the inner peripheral surface, and the axial position of the outward flange portion provided on the outer peripheral surface is at least the outward direction. When forging a race ring member in which a part of the flange portion in the thickness direction exists between the center positions of the outer races, the intermediate cylindrical portion may be exposed on the raceway surfaces. difficult. For example, when the outer ring 2 of the wheel supporting rolling bearing unit 1 shown in FIG. 7 is manufactured by the method described in the Patent Document 1 as shown in FIG. Metal material of each part inside, that is, metal material 12 of a cylindrical portion closer to the center from the center to 50% of the radius, and metal existing in the intermediate cylindrical portion whose radius from the center is in the range of 50 to 70% The material 13 and the metal material 14 present in the cylindrical portion near the outer diameter in the range of 30% near the outer diameter are distributed in the outer ring 2 as shown in FIG. The outer ring 2 is manufactured by forging the intermediate material 15 shown by a solid line in FIG. 11, and then cutting and grinding the intermediate material 15 to the state shown by the chain line by cutting and grinding. To be completed.

  In FIG. 11 showing such an intermediate material 15 and the outer ring 2, if the metal material 13 present in the intermediate cylindrical part shown by the oblique lattice is exposed to the pair of outer ring raceways 5 and 5, It is easy to ensure the rolling fatigue life of the outer ring raceways 5 and 5 and to ensure the durability of the wheel bearing rolling bearing unit 1 including the outer ring 2. However, as apparent from FIG. 11, when the outer ring 2 is manufactured by the conventional manufacturing method, the metal material 12 of the cylindrical portion closer to the center is the outer ring raceway on the axially inner side of the outer ring raceways 5 and 5. 5 is exposed on a part of the surface. For this reason, in a conventionally known method for manufacturing a bearing ring member, the degree of freedom in design for ensuring the durability of the wheel bearing rolling bearing unit 1 is limited.

  In Patent Document 2, by devising an extrusion method when performing a front-rear extrusion process on a columnar material, a metal material 12 of a columnar portion closer to the center is formed on a portion of the intermediate material that becomes an outer ring raceway. It describes about the manufacturing method of a bearing ring member so that {the oblique lattice part of FIG. 12 (B) (C) described below} does not exist. In the case of such a conventional manufacturing method, the center portions of both axial end surfaces of the cylindrical material 16 as shown in FIG. 12A are crushed in a direction approaching each other, and FIGS. The intermediate material provided with the first and second circular recesses 17 and 18 opened on both axial end surfaces and the partition wall 19 existing between the bottom surfaces of the circular recesses 17 and 18 as shown in FIG. 20 Further, the intermediate material 20 is subjected to predetermined cutting (turning) processing and grinding processing to obtain an outer ring 2b having a cross-sectional shape as indicated by a chain line in FIGS.

  In the case where the formation position of the partition wall 19 is not devised, the metal material 12 of the cylindrical portion near the center is present in the portion to be the outer ring raceways 5 and 5 as shown in FIG. On the other hand, as shown in FIG. 12C, when the partition wall 19 is formed at a position between the portions to be the outer ring raceways 5 and 5, the metal material of the cylindrical portion near the center is formed. 12 no longer exists in the portion to be the outer ring raceway 5, 5. However, as shown in FIG. 12C, the reduction in manufacturing cost and the improvement in durability cannot be achieved at a high level only by devising the formation position of the partition wall 19.

  That is, the partition wall 19 is then punched and removed, and discarded and recovered as scrap. Therefore, the axial dimension (thickness) of the partition wall 19 is preferably as small as possible from the viewpoint of facilitating the punching and removing operation and the aspect of improving the material yield. However, when the partition wall portion 19 is further crushed from the state shown in FIG. 12C, the metal material 12 in the central cylindrical portion moves to the portions to be the outer ring raceways 5, 5, It becomes difficult to ensure the rolling fatigue life of both outer ring raceways 5 and 5. In other words, in the manufacturing method shown in FIGS. 12A to 12C, the axial dimension of the partition wall 19 needs to be considerably increased, which is preferable from the viewpoint of suppressing the manufacturing cost as an industrial product. Absent.

JP 2005-83513 A JP 2006-250317 A

  In view of the circumstances as described above, the present invention provides a circular ring member including a double-row outer ring raceway at two axial positions on the inner peripheral surface, an outward flange on the outer peripheral surface, and a cylindrical material. When building by plastic deformation, the metal material of the intermediate cylindrical part with high cleanliness among the raw materials can be exposed to at least the part where the rolling element load acts on both outer ring raceways, and at low cost. The invention was invented to realize a method of manufacturing a bearing ring member that can be implemented in the above. In the case of a race ring member that is an object of the manufacturing method of the present invention, at least a part of the outward flange portion is between the center positions of both the outer race tracks (a chain line in FIG. 3 described later). It must be present between α and β. In the case where the axial position of the outward flange does not satisfy this condition, it is necessary to manufacture by a manufacturing method different from the present invention.

In the method of manufacturing a race ring member of the present invention, a cylindrical material is plastically deformed to form double-row outer ring raceways at two positions in the axial direction of the inner peripheral surface, and an outward flange is formed on the outer peripheral surface. A raceway ring member is formed by forming at least part of the outward flange portion in the thickness direction between the center positions of the outer raceways.
In particular, in the method of manufacturing a bearing ring member according to the present invention, the material is close to the bearing ring member by a first upsetting process, a front-rear pushing process, and a second upsetting process ( A third intermediate material having a shape that can be machined into this ring member by performing necessary cutting and grinding.

First, in the first upsetting step, the material is crushed in the axial direction to obtain a first intermediate material.
Next, in the front-rear extrusion step, the central portions of the axial end faces of the first intermediate material are crushed in a direction approaching each other, and the first circular recess opening on the one axial end surface side and opening on the other axial end surface side are opened. The second intermediate material includes a second circular recess and a partition wall existing between the bottom surfaces of both circular recesses.
Further, in the second upsetting step, the partition wall is crushed without changing the depth of the first circular recess of the second intermediate material, and the metal material is moved radially outward. . Then, the outward flange is formed in a state in which at least a part of the outward flange in the thickness direction is located around the first circular concave portion, thereby forming the third intermediate material.

When carrying out the present invention as described above, if necessary, in the front-rear extrusion step, a step is formed between the back half with a small inner diameter and the opening half with a large inner diameter. A first circular recess is formed which is continuous at the portion.
Alternatively, as described in claim 3, the inner shape of the first circular recess is not changed during the second upsetting step.
Alternatively, as described in claim 4, the inner shape of the second circular recess is not changed during the second upsetting step.
Alternatively, as described in claim 5, in the front-rear extrusion step, a second circular recess is formed in which a back half having a small inner diameter and an opening half having a large inner diameter are continuously provided by a stepped portion.
When carrying out such an invention described in claim 5, for example, as described in claim 6, during the second upsetting process, the cylindrical portion surrounding the second circular recess is crushed, and this first The inner shape of the two circular recesses is changed in the direction of decreasing the depth dimension.

  In carrying out the invention as described in the above first to fourth aspects, preferably, as described in the seventh aspect, the second upsetting process is performed around the first punch. The die is moved by using an upsetting device that can be moved up and down with respect to the first punch. And, the first punch in the first circular recess of the second intermediate material, the second punch in the second circular recess, and fitted in a state that does not interpose a gap that leads to the deformation of both the recesses, The other axial end of the second intermediate material is fitted into a second die disposed around the second punch. Thereafter, the first die is directed to the second die, and a predetermined amount of the second intermediate material is moved while being pressed, so that the shape of the outer peripheral surface of the end portion in the axial direction of the second intermediate material is changed. Process according to the shape of the inner peripheral surface of the first die. Next, the first punch is directed to the second punch, and the first die is pressed in synchronism with the pressing of the second die. Then, the outward flange is formed by moving the metal material to the molding space existing between the front end surfaces of these dies.

In carrying out the invention described in claim 7, preferably, as described in claim 8, after the third intermediate material is formed by the second upsetting process, both the first and second Corresponding to the gap between the tip surfaces of the dies, the burr formed in a state protruding radially outward from the outer peripheral surface is punched and removed on the outer peripheral surface of the outward flange to form a fourth intermediate material. .
In carrying out the present invention, if necessary, as described in claim 9, after the second upsetting process, the partition wall is punched and removed.

  According to the method of manufacturing the raceway ring member of the present invention configured as described above, at least a portion on which the rolling element load acts is formed on both outer raceways formed at two positions on the inner circumferential surface separated in the axial direction. Furthermore, the metal material of the intermediate cylindrical portion having a high cleanliness among the raw materials can be exposed. For this reason, the rolling fatigue life of the both outer ring raceways can be ensured, and the degree of freedom in design for ensuring the durability of the wheel bearing rolling bearing unit including the raceway ring members having the both outer ring raceways can be improved. In addition, even if the axial dimension (thickness) of the partition wall is reduced, a metal material with a high degree of cleanness can be exposed to the part where the rolling element load acts on both outer ring raceways. The increase in manufacturing cost can be suppressed by facilitating the operation and improving the material yield.

Further, if necessary, by adopting the configuration described in claims 2 to 6, the metal material of the intermediate cylindrical portion is changed according to the axial position of the outward flange and the installation position of each outer ring raceway. It is effectively exposed to the surface portion of the outer ring raceway.
Further, as described in claim 7, if the second upsetting process is performed by using the upsetting apparatus including both the first and second punches and the first and second dies, the front and rear extrusion is performed. With the processing, the outward flange can be efficiently processed while the metal material of the intermediate cylindrical portion that has moved to the portion to be the outer ring raceway in the second intermediate material is held in its position.
Further, as described in claim 8, if the burrs formed corresponding to the gaps between the tip surfaces of both the first and second dies are punched and removed, the volume of the material is strictly limited. Even if it does not restrict | regulate, the dimension and shape of each part including the said outward flange can be made with high precision as desired.
Furthermore, according to the manufacturing method of the bearing ring member of the invention described in claim 9, it is possible to remove a useless metal material and obtain a lightweight wheel support rolling bearing unit. In addition, instead of thinning other portions such as the cylindrical portion that forms the outer ring raceway, it is possible to adopt a structure that maintains the strength by the partition wall. In this case, the partition wall is removed. No process is required.

[First example of embodiment]
FIGS. 1-5 has shown the 1st example of embodiment of this invention corresponding to Claims 1-4 and 7-9. The manufacturing method of this example is a metal cylindrical material that can be quenched and hardened after plastic working, such as an iron-based alloy such as medium carbon steel, bearing steel, and carburized steel, as shown in FIG. 16 is sequentially subjected to plastic working or punching. Then, the first intermediate material 21 shown in (B), the second intermediate material 22 shown in (C), the third intermediate material 23 shown in (D), and the fourth intermediate material 24 shown in (E). Then, the fifth intermediate material 25 shown in (F) is obtained. Further, the fifth intermediate material 25 is subjected to necessary cutting and grinding to form an outer ring 2 constituting the inner ring rotating type wheel support rolling bearing unit 1 as shown in FIG. . Hereinafter, the process of processing the material 16 into the fifth intermediate material 25 will be described in order. The following processing is basically performed either hot or warm, but may be performed cold if possible, such as when a small hub is formed.

First, in the first upsetting step, as shown in FIG. 1A to FIG. 1B, the outer diameter is expanded while the material 16 is crushed in the axial direction, The first intermediate material 21 is an expanded beer barrel type.
In the next front-rear extrusion process, the first intermediate material 21 is plastically processed into the second intermediate material 22 as shown in FIGS. In such a front-rear extrusion process, the radially intermediate portion of the first intermediate material 21 is compressed in the axial direction by a method widely known in the field of forging, so that the metal material is radially outward. While moving, move it on both sides in the axial direction (both front and rear).

  The process of compressing the radially intermediate portion of the first intermediate material 21 in the axial direction corresponds to the shape of the outer peripheral surface of the second intermediate material 22 (the irregularities are reversed). In the state set in the die, it is performed by pressing the central part of both axial end surfaces of the first intermediate material 21 between the pressing punch and the counter punch arranged concentrically with each other. In general, the pressing punch is pressed against the counter punch while the counter punch arranged on the lower side in FIG. 1 is fixed. Then, the metal material constituting the first intermediate material 21 is moved to fill a cavity surrounded by the inner peripheral surface of the die and the outer surfaces (outer peripheral surface and tip surface) of the pressing punch and the counter punch. Thus, the second intermediate material 22 is obtained. The second intermediate material 22 has a first circular recess 26 that opens to the one end surface in the axial direction (the upper end surface in FIGS. 1 to 5) and a second opening that opens to the other end surface in the axial direction (the lower end surface in FIGS. 1 to 5). The circular recessed part 27 and the partition part 28 which exists between the bottom surfaces of these circular recessed parts 26 and 27 are provided. In the case of this example, the shape of the first circular concave portion 26 is a stepped shape in which a back half portion having a small inner diameter and an opening side half portion having a large inner diameter are continuously provided by a step portion. For this reason, a stepped punch having a small outer diameter at the front half and a large outer diameter at the base half is used as the pressing punch. In such a front-rear extrusion process, as the first intermediate material 21 is plastically processed into the second intermediate material 22, the metal material 12 of the central cylindrical portion, the metal material 13 of the intermediate cylindrical portion, The distribution state of the cylindrical portion closer to the outer diameter with the metal material 14 changes as shown in FIGS. 4B to 4C. As apparent from FIG. 4C and FIG. 5, in the stage of the second intermediate material 22, the portion where the outer ring raceways 5, 5 are to be formed later is a metal with a high degree of cleanness in the intermediate cylindrical portion. Material 13 is present.

  The second intermediate material 22 made as described above is used as the third intermediate material 23 in the next second upsetting process. This second upsetting step is performed using the upsetting apparatus shown in FIG. This upsetting apparatus includes a press punch 29 corresponding to the first punch described in the claims, a counter punch 30 corresponding to the second punch, an upper die 31 corresponding to the first die, and a first punch. A lower die 32 corresponding to two dies and an extrusion punch 33 are provided.

  Among these constituent members 29 to 33, the upper die 31 is fixed to the lower surface of the ram of the press machine and moves up and down together with the ram. The pressing punch 29 is supported on the inner diameter side of the upper die 31 so that a predetermined amount of axial displacement (elevation) with respect to the upper die 31 is possible. When the ram is lowered, the pressing punch 29 stops at a small resistance until the upper die 31 is lowered by the predetermined amount, and only the upper die 31 is allowed to descend. On the other hand, when the upper die 31 is lowered by a predetermined amount with respect to the pressing punch 29, the upper end surface of the pressing punch 29 comes into contact with one surface of the ram. When the ram is further lowered from this state, the pressing punch 29 is also lowered together with the upper die 31.

  On the other hand, the counter punch 30 and the lower die 32 are fixed concentrically to each other on the upper surface of the support base of the press machine, and between the two, the second half of the second intermediate material 22 is axially outer half. A lower cavity 34 having an inner surface shape corresponding to the outer surface shape of the part (irregularities are reversed) is provided. The counter punch 30 and the lower die 32 are not displaced as the second upsetting process proceeds. Further, the extrusion punch 33 has a cylindrical shape, and a lower end portion of the lower cavity 34 is partitioned by an upper end surface thereof. Such an extrusion punch 33 is supported so as to be movable up and down with respect to a support base of the press machine. Then, with the extrusion punch 33 fully lowered, the inner surface shape of the lower cavity 34 becomes a shape commensurate with the outer surface shape of the second half of the second intermediate material 22 in the axial direction.

  In the case where the second intermediate material 22 is subjected to the second upsetting step using the upsetting apparatus having the above-described configuration, first, the first circular concave portion of the second intermediate material 22 is provided. 26 and the second circular recess 27 are fitted with the counter punch 30 in a state where there is no gap between them, which leads to deformation of both the recesses 26 and 27, and the second intermediate material 22 is inserted. The other end in the axial direction is fitted into the lower die 32. Thereafter, as shown in FIGS. 2A to 2B, the upper die 31 is moved toward the lower die 32 by a predetermined amount. Along with this movement, the upper die 31 presses a part of the second intermediate material 22, that is, a portion closer to the outer diameter of the inner end portion in the axial direction, and plastically deforms radially outward. At the same time, the shape of the outer peripheral surface of the inner end side portion in the axial direction of the second intermediate material 22 is processed according to the inner peripheral surface shape of the upper die 31. At this time, the pressing punch 29 does not descend due to the resistance of the second intermediate material 22 but remains in the same position.

  When the upper die 31 is lowered by the predetermined amount with respect to the pressing punch 29, the upper end surface of the pressing punch 29 and the lower end surface of the ram come into contact with each other. When the ram is further lowered from this state, the pressing punch 29 starts to descend toward the counter punch 30. That is, the upper die 31 presses the outer diameter portion of the second intermediate material 22 in the axial direction, and at the same time, the pressing punch 29 moves from the axial inner end surface of the second intermediate material 22 to the partition wall 28. Is pressed on the inner side surface in the axial direction. Then, as shown in FIGS. 2B to 2C, while the axial dimension (thickness) of the partition wall portion 28 is reduced, the molding exists between the tip surfaces of the dies 31 and 32. A metal material is moved to the space 35 to form the attachment portion 6 which is an outward flange described in the claims, and the third intermediate material 23 as shown in FIG.

  Along with the second upsetting step shown in FIG. 1 (C) → (D), the metal material 12 of the central cylindrical portion, the metal material 13 of the intermediate cylindrical portion, The distribution status of the cylindrical portion closer to the outer diameter with the metal material 14 changes as shown in (C) → (D) of FIG. In the second upsetting step, the inner surface shapes of the circular recesses 26 and 27 adjacent to the portions where the outer ring raceways 5 and 5 are to be formed are not changed. For this reason, as is apparent from FIG. 4D and FIG. 5, even in the stage of the third intermediate material 23, the portion where the outer ring raceways 5 and 5 are to be formed later has an intermediate cylindrical shape with high cleanliness. Part of the metal material 13 is present.

  In the case of this example, when the processing of the third intermediate material 23 is completed, the tip surfaces of the dies 31 and 32 do not contact each other, and there is a gap 36 between the tip surfaces. Intervene. A surplus of metal material enters the gap 36 to form a burr 37. The third intermediate material 23 having the burr 37 projecting from the outer peripheral surface of the mounting portion 6 manufactured in this way raises the pressing punch 29 and the upper die 31 and then pushes the extrusion punch 33. Is removed from the upsetting device. Then, as shown in (D) → (E) of FIG. 1, the burr 37 is punched and removed to form the fourth intermediate material 24.

  Finally, as shown in FIGS. 1E to 1F, the partition wall 28 existing between the circular recesses 26 and 27 is punched and removed by pressing or the like, and the fifth The intermediate material 25 is used. The fifth intermediate material 25 is thicker than the outer ring 2 after completion (see the chain line in FIG. 3). Accordingly, the fifth intermediate material 25 is subjected to predetermined cutting (turning) processing and grinding processing to complete the outer ring 2. FIG. 5 shows a distribution state of the metal materials 12 to 14 at the stage of the fourth intermediate material 24 and a cross-sectional shape of the outer ring 2 after completion (see the chain line in FIG. 5). As apparent from FIG. 5, according to the manufacturing method of the outer ring 2 of this example, the outer ring raceways 5, 5 formed at two positions separated in the axial direction on the inner peripheral surface of the outer ring 2. Among them, the metal material 13 of the intermediate cylindrical portion having a high cleanliness among the raw materials can be exposed to at least a portion where the rolling element load acts. For this reason, the rolling fatigue life of the both outer ring raceways 5 and 5 is ensured, and the degree of freedom in design for ensuring the durability of the wheel bearing rolling bearing unit including the outer ring 2 provided with the both outer ring raceways 5 and 5 is improved. Can be planned.

[Second Example of Embodiment]
FIG. 6 shows a second example of an embodiment of the present invention corresponding to claims 1 to 3, 5, 6, 8 and 9. This example is different from the first example described above in the following three points (a) to (c).
(a) The axial position of the mounting portion 6 formed on the outer peripheral surface of the outer ring 2c is biased toward the inner half in the axial direction as compared with the case of the first example.
(b) The shape of the second circular recess 27a processed in the front-rear extrusion process is different from that of the first example.
(c) During the second upsetting step, the cylindrical portion surrounding the second circular recess 27a is crushed.

  First, with respect to the point (b), the outer peripheral surface shape of the pressing punch used in the front-rear extrusion process shown in FIGS. 6B to 6C is different from that of the first example. Specifically, as the pressing punch, the one having the outer diameter of the front half portion being small and the outer diameter of the base half portion being large is used, and the second circular concave portion 27a processed by pressing the pressing punch is used. The inner surface shape is a shape in which a back half 38 having a small inner diameter and an opening side half 39 having a large inner diameter are connected by a stepped portion 40. Further, the axial dimension (thickness) of the partition wall 28a between the bottom surface of the second circular recess 27a and the bottom surface of the first circular recess 26 is made smaller than in the case of the first example.

In the case of this example, after the second circular recess 27a as described above is formed in the front / rear extrusion process, the second upsetting process shown in FIG. 6 (C) → (D) A portion near the inner end in the axial direction of the intermediate material 22a is crushed in the axial direction, and this portion is plastically deformed in a direction to reduce the depth dimension of the second circular recess 27a. Along with the plastic deformation, the metal material is moved to the partition wall portion 28a, and the axial dimension of the partition wall portion 28a is increased. However, the inner shape of the first circular recess 26 is not changed.
According to this example, the two outer ring raceways 5 and 5 formed at two positions separated in the axial direction on the inner peripheral surface of the outer ring 2c, regardless of the difference in the axial position of the mounting portion 6. Among them, the metal material 13 of the intermediate cylindrical portion having a high cleanliness among the raw materials can be exposed to at least a portion where the rolling element load acts.

  In the above description, the outer ring 2, 2a constituting the inner ring rotating type wheel support rolling bearing unit 1, 1b as shown in FIGS. 7 and 9 is manufactured by the method of manufacturing the bearing ring member of the present invention. The explanation was focused on the case. However, even in the hub 10 constituting the outer ring rotating type wheel support rolling bearing unit 1a as shown in FIG. 8, the axial position of the support flange 7a satisfies the conditions of the present invention (FIG. If it exists to the right of 8), it can be produced by the production method of the present invention.

Sectional drawing of the raw material thru | or 5th intermediate material which shows the 1st 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 a 2nd upsetting process in order of a process. Sectional drawing which shows the range of the axial position of an attaching part regarding the outer ring which can apply the manufacturing method of this invention. As the processing from the material to each intermediate material progresses, the distribution status of the metal material in the central cylindrical part, the metal material in the intermediate cylindrical part, and the metal material in the cylindrical part near the outer diameter changes. FIG. Sectional drawing which shows the distribution condition of the metal material of the cylindrical part near the center, the metal material of the intermediate cylindrical part, and the metal material of the cylindrical part near the outer diameter at the stage of the fourth intermediate material. The figure similar to FIG. 4 which shows the 2nd example of embodiment of the manufacturing method of the bearing ring member of this invention. 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 which shows two examples of the manufacturing method of the ring member conventionally known conventionally in order of a process. Shows the distribution of the metal material near the center, the metal material near the middle cylindrical part, and the metal material near the outer diameter cylindrical part in the state where the third intermediate material is made by the conventional manufacturing method Sectional drawing. Another example of the conventional manufacturing method is described. The cross-sectional shape (A) of the material, the cross-sectional shape of the intermediate material (B) when the position of the partition wall is not devised, and the cross-sectional shape of the intermediate material (when devised) FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b Rolling bearing unit for wheel support 2, 2a, 2b, 2c Outer ring 3, 3a Hub 4 Rolling element 5 Outer ring raceway 6 Mounting part 7, 7a Support flange 8 Inner ring raceway 9, 9a Inner ring 10 Hub 11 Hub body 12 Metal material of the cylindrical portion closer to the center 13 Metal material of the intermediate cylindrical portion 14 Metal material of the cylindrical portion closer to the outer diameter 15 Intermediate material 16 Material 17 First circular concave portion 18 Second circular concave portion 19 Partition portion 20 Intermediate material 21 First intermediate material Material 22, 22a Second intermediate material 23 Third intermediate material 24 Fourth intermediate material 25 Fifth intermediate material 26 First circular concave portion 27, 27a Second circular concave portion 28, 28a Partition portion 29 Press punch 30 Counter punch 31 Upper die 32 Lower die 33 Extrusion punch 34 Lower cavity 35 Molding space 36 Gap 37 Burr 38 Back half 3 9 Opening side half 40 Stepped part

Claims (9)

  By plastically deforming the cylindrical material, double row outer ring raceways are formed at two positions in the axial direction of the inner peripheral surface, and an outward flange is provided on the outer peripheral surface, at least in the thickness direction of the outward flange portion. In the method for manufacturing a race ring member, a part of the outer ring raceway is formed between the center positions of both outer race raceways. The first upsetting step to be a material and the axial center end portions of the first intermediate material are crushed in a direction approaching each other, the first circular recess opening on one axial end surface side and the other axial end surface side A front-rear extrusion process as a second intermediate material having a second circular recess opening and a partition wall between the bottom surfaces of both circular recesses, and the first circular recess of the second intermediate material Without changing the depth of the Crushing and moving the metal material radially outward, and forming the outward flange with a third intermediate material formed with at least a part of the thickness of the outward flange positioned around the first circular recess. And a second upsetting step. A method for manufacturing a bearing ring member.   The manufacturing method of the bearing ring member of Claim 1 which forms the 1st circular recessed part which continued the back half part with a small internal diameter, and the opening side half part with a large internal diameter by the level | step-difference part by the front-rear extrusion process.   The method for manufacturing a bearing ring member according to any one of claims 1 to 2, wherein the inner surface shape of the first circular recess is not changed during the second upsetting step.   The method for manufacturing a bearing ring member according to any one of claims 1 to 3, wherein the inner surface shape of the second circular recess is not changed during the second upsetting step.   The front-rear extrusion step forms a second circular concave portion in which a back half portion having a small inner diameter and an opening half portion having a large inner diameter are made continuous by a stepped portion. Method for manufacturing a bearing ring member.   The track according to claim 5, wherein, during the second upsetting step, the cylindrical portion surrounding the second circular recess is crushed to change the inner surface shape of the second circular recess in the direction of decreasing the depth dimension. A manufacturing method of a ring member.   The second upsetting step is performed by using the first die around the first punch and the upsetting device provided so as to be able to move up and down with respect to the first punch. The first punch is fitted in the second circular recess, and the second punch is inserted in a state that does not interpose a gap that leads to deformation of both recesses, and the other axial end of the second intermediate material is inserted, After being fitted into a second die arranged around the second punch, the first die is directed to the second die, and a part of the second intermediate material is pressed and moved by a predetermined amount. Processing the shape of the outer peripheral surface of the one end portion in the axial direction of the second intermediate material in accordance with the inner peripheral surface shape of the first die, and then directing the first punch toward the second punch, Pressing in sync with pressing on the second die The manufacturing of the bearing ring member according to any one of claims 1 to 4, wherein a metal material is moved to a forming space existing between the front end surfaces of both dies to form an outward flange. Method.   After the third intermediate material is produced by the second upsetting process, the outer peripheral surface of the outward flange is radially outward from the outer peripheral surface corresponding to the gap between the tip surfaces of the first and second dies. The method for manufacturing a bearing ring member according to claim 7, wherein the burr formed in a protruding state is punched and removed to form a fourth intermediate material.   The method for manufacturing a bearing ring member according to any one of claims 1 to 8, wherein the partition wall portion is punched and removed after the second upsetting process.

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