JP2006247738A - Method for manufacturing cage of thrust roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a cage of a thrust roller bearing which is excellent in durability by securing a sufficient plate thickness and a proper clearance between the roller and a roller retaining section so as to maintain the strength of the cage. <P>SOLUTION: An annular member is formed by punching a pilot hole (step a), a pocket (step b), an inner diameter (step c) and an outer diameter (step d) in a coil stock such as a cold rolled steel plate. On each of both sides of the annular member a ring-shaped groove is formed by lessening the plate thickness. Then a plurality of pockets for holding the roller are formed by punching (step g) and first and second roller touching sections are formed on the wall face of each pocket at the same time. At the next steps h and i, a roller retaining section and a roller guiding face are formed on each of the first and second roller touching sections. Last, an inner diameter (step j) and an outer diameter (step k) are formed by punching whereby the cage of the thrust roller bearing is completed (step l). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a thrust roller bearing used in an automatic transmission, a compressor, and the like.

  A thrust roller bearing used for an automatic transmission or a compressor of an automobile is described in, for example, Japanese Patent Application Laid-Open No. 2000-192965 (Patent Document 1). The thrust roller bearing described in the publication includes a roller and a cage 1 having a plurality of pockets 2 for accommodating the roller on an annular circumferential surface as shown in FIG. is doing.

  As shown in FIG. 2, the cross section taken along line A-A ′ of the cage 1 is formed by punching the pocket 2 by forming an annular plate material into a W shape by pressing. In the pocket 2, a plurality of roller stoppers 3 that prevent the rollers 5 from dropping off and a roller guide surface 4 that guides the rotation of the rollers 5 are formed during punching.

  The adjacent roller stoppers 3 are provided by shifting the positions of the bearing rotation axis direction and the roller 5 in the rotation axis direction. In FIG. 2, roller stoppers 3 are formed on the upper center portion of the pocket 2 and on the lower sides of both end portions. Further, the roller guide surface 4 is provided in an inclined portion between the adjacent roller stoppers 3.

  Here, the bearing rotation axis indicates an imaginary axis that passes through the center of the roller raceway during rotation of the bearing. The roller rotation axis indicates a virtual axis passing through the center of the roller rotation.

As shown in FIG. 3, the roller stopper 3 protrudes from the wall surface of the pocket 2, and prevents the rollers 5 from falling off when the thrust roller bearing is stopped. On the other hand, during the rotation of the thrust roller bearing, as shown in FIG. 4, the roller 5 is guided by the roller guide surface 4 without being in contact with the roller stopper 3 and maintaining the gap d _0. Rotate.

The thrust roller bearing as described above has an advantage that high load capacity and high rigidity can be obtained for a small bearing projected area because the roller and the rolling contact surface are in line contact.
JP 2000-192965 A

  In recent years, downsizing of automatic transmissions, compressors, and the like has progressed, and accordingly, there is a strong demand for reducing the axial thickness of thrust roller bearings used in these devices.

In general, when the size of a thrust roller bearing as shown in FIG. 4 is reduced, normally, as shown in FIG. 5A, the roller diameter, the thickness of the W-type cage, the plate of the W-type cage The thicknesses are reduced by a predetermined ratio of φ ₀ > φ ₁ , w ₀ > w ₁ , and t ₀ > t ₁ , respectively.

However, in order to maintain the strength of the W-type cage can not be too thin the thickness t ₁ of the W-type cage.

Therefore, as shown in FIG. 5B, without changing the roller diameter φ ₁ and the thickness dimension W ₁ of the W-type cage, the plate thickness t ₂ of the W-type cage is set to satisfy t ₁ <t _2. If set to, in order to prevent falling off of the 5 days, it must be smaller clearance volume d _2. When clearance amount d ₂ is reduced, it will be scraped off the outer circumferential surface lubricant of stopping part 3 Dekoro 5 rollers, which may lead to poor rotation.

  Further, in order to secure an appropriate amount of play, if the amount of protrusion from the end face of the pocket 2 of the roller stopper 3 is reduced and the frontage is widened, the roller 5 cannot be prevented from falling off.

On the other hand, as shown in FIG. 5C, when the plate thickness t ₃ is set to satisfy t ₁ > t ₃ , it is possible to sufficiently secure the play amount d ₃ , but the holding amount is maintained. The strength of the vessel is further reduced.

  Further, as a conventional problem, the roller guide surface 4 formed by punching includes a fracture surface in a part thereof. As a result, the contact resistance between the rough guide surface 4 and the roller 5 is increased, and iron powder is generated due to wear. In particular, under lean lubrication, the bearing may be damaged due to poor lubrication such as oil film breakage.

  The object of the present invention is to produce a thrust roller bearing retainer that has a sufficient thickness to maintain the strength of the cage and an appropriate amount of play between the roller and the roller stopper, and has excellent durability. Is to provide a method.

  A method of manufacturing a cage for a thrust roller bearing according to the present invention includes forming an annular member from a steel plate by punching, and reducing the plate thickness to one side and the other side of the annular member by pressing, respectively. A groove is formed on the surface of the annular member that intersects the bearing rotation axis, and there are a plurality of pockets that accommodate the rollers, and the pocket wall surfaces that are shifted in the bearing rotation axis direction and the roller rotation axis direction. In relation, the first roller contact portion and the second roller contact portion are formed by punching.

  The cage of the thrust roller bearing manufactured by the above method can increase the plate thickness up to the thickness dimension of the cage. As a result, it is possible to obtain a cage having extremely high strength as compared with the conventional cage.

  The punching of the annular member includes not only a case where the annular member is completely separated from the steel plate but also a case where a part of the annular member is connected to the steel plate and proceeds to the next process.

  Preferably, the first roller contact portion includes a first roller stopper that prevents the roller from coming off in one direction by pressing the corner portion on the contact side of the roller, and a first roller that guides the rotation of the roller. And a second roller stopper for preventing the roller from coming off in the other direction by guiding the corners on the contact side of the roller to the second roller contact portion and guiding the rotation of the roller. A second roller guide surface may be formed.

  By adopting the above configuration, the size of the roller stopper can be freely determined within the range of the plate thickness of the cage, so that the plate thickness necessary for ensuring the strength of the cage is maintained. The amount of play between the roller and the roller stopper can be set to an appropriate value.

  In the present specification, “surface pressing” refers to a processing method for forming a surface of a workpiece into a desired shape by plastic processing. According to this processing method, the surface of the processed product becomes a smooth surface, and can have various shapes depending on the shape of the processing tool.

  In the surface pressing process, for example, the first roller contact portion and the second roller contact portion are processed in separate steps. Thereby, the shape of a tool can be simplified.

  The surface pressing process is, for example, burnishing. Thereby, since a smooth guide surface can be obtained, contact resistance with a guide surface place can be eased and generation | occurrence | production of the iron powder by abrasion can be suppressed. Further, even under lean lubrication, high lubrication performance can be maintained without causing oil film breakage or the like. In the present specification, “burnishing” refers to a processing method in which a tool is pressed against a surface of a workpiece and slid to smooth the surface.

  The press work is, for example, coining. The cage formed by coining has a higher strength than the case where it is formed by bending, and deformation due to processing or heat treatment is extremely small. Even when deformation occurs, it can be corrected by a press temper.

  In the present specification, coining is a form of cold forging and refers to a processing method for forming irregularities on the material surface by pressing a die from above and below. In addition, the press temper refers to a method for correcting deformation such as bending by pressing during tempering.

  The method for manufacturing the cage of the thrust roller bearing is performed, for example, by a progressive press. Thereby, since each process can be performed continuously, productivity can be improved and the product price of a thrust roller bearing can be held down as a result.

  In the present specification, “sequential press” refers to a method of continuously processing a material by having a plurality of processing steps in the press and moving the material by a feeder at a press inlet. Shall.

  The present invention provides a thrust roller bearing capable of securing an appropriate amount of clearance between the roller and the roller stopper without reducing the plate thickness of the cage even when used for a thrust roller bearing having a small roller diameter. A cage can be manufactured.

  With reference to FIGS. 6-9, one Embodiment of the thrust roller bearing manufactured by the manufacturing method which concerns on this invention is described.

  The thrust roller bearing according to the present invention includes a roller 17 and a cage 11. The cage 11 is provided with ring-shaped grooves 12 on both sides thereof with a reduced thickness. In this embodiment, as shown in FIG. 6, ring-shaped grooves 12 are provided on the lower side surface of the central portion and the upper side surfaces of both end portions by coining processing or the like.

  Further, the cage 11 has a plurality of pockets 13 for accommodating the rollers 17 as shown in FIG. 7 on the surface intersecting the bearing rotation axis. The pocket 13 includes a plurality of roller contact portions 14 and 15 protruding from the wall surface facing the outer peripheral surface of the roller 17, and a roller non-contact portion 16 provided at a position retracted from the roller contact portions 14 and 15.

  Adjacent roller contact portions 14 and 15 are provided at a plurality of positions by shifting the positions in the bearing rotation axis direction and the roller rotation axis direction. In this embodiment, as shown in FIG. 8, a first roller contact portion 14 is formed above the central portion of the pocket 13, and a second roller contact portion 15 is formed below both end portions.

  Furthermore, as shown in FIG. 9, the first roller contact portion 14 includes a first roller stopper 14 a that prevents the roller 17 from coming off upward, and a first roller guide that guides the rotation of the roller 17 on its processed surface. The second roller contact portion 15 has a surface 14b, and the second roller contact portion 15 prevents the roller 17 from coming off downward, and the second roller guide surface 15b guides the rotation of the roller 17 to the processed surface. And have.

  By setting it as the said structure, the plate | board thickness t of the holder | retainer 11 can be thickened to the thickness dimension of the holder | retainer 11. FIG. As a result, it is possible to obtain the cage 11 having extremely high strength as compared with the conventional cage.

  Further, since the size of the roller stoppers 14a and 15a can be freely determined within the range of the plate thickness t of the cage 11, the plate thickness t necessary for ensuring the strength of the cage 11 is maintained. In addition, the amount of play between the roller 17 and the roller stoppers 14a and 15a can be set to an appropriate value. As a result, it is possible to prevent the lubrication performance of the thrust roller bearing from being lowered.

  The roller guide surfaces may be provided between the adjacent roller contact portions 14 and 15, but conventionally, the roller contact surfaces 14b and 15b are used as the processed surfaces of the roller contact portions 14 and 15, so that the roller guide surfaces have been conventionally used. The cut surface portion at the time of punching can be the roller non-contact portion 16.

  Since the roller non-contact portion 16 can be largely retracted from the roller guide surfaces 14b and 15b, the interval between the roller non-contact portion 16 and the roller 17 can be increased as shown in FIG. Thereby, oil permeability to the inside of the bearing is enhanced, and a thrust roller bearing having high lubrication performance can be obtained.

  Since the ring-shaped groove 12 of the cage 11 is formed by coining or other cold forging, the cage strength is high and deformation due to processing or heat treatment is extremely small. Even when deformation occurs, it can be corrected by a press temper.

  The relationship between the plate thickness t of the cage 11 and the roller diameter φ of the roller 17 is t / φ ≧ 0.6 and φ ≦ 2. When the plate thickness t of the cage 11 is reduced, the amount of play d between the roller 17 and the roller contact portions 14 and 15 is reduced, and the lubricating oil on the outer peripheral surface of the roller 17 is scraped off by the roller contact portions 14 and 15. This may cause rotation failure.

  Therefore, in a thrust roller bearing having a roller diameter φ of 2 mm or less, the relationship between the plate thickness t of the cage 11 and the roller diameter φ of the roller 17 is t / φ ≧ 0.6, so that Problems can be avoided.

  The cage shown in each of the above embodiments is a finished product by heat treatment, for example, carburizing and quenching and tempering, or instead of carbonitriding or soft nitriding.

  In the above embodiment, an example of a thrust roller bearing including a roller and a cage has been described. However, the present invention is not limited thereto, and a thrust roller bearing further including a raceway may be used.

  Next, with reference to FIG. 10, the procedure for manufacturing the cage 11 as shown in FIG. 8 by the method for manufacturing the cage of the thrust roller bearing according to the embodiment of the present invention will be described.

  As a raw material for the cage of the thrust roller bearing according to the present invention, for example, a coil-shaped cold rolled steel sheet or the like is used.

  First, a pilot hole for determining the processing position of each processing step is formed by punching (a step), and a pocket (b step), an inner diameter (c step) are preliminarily left, and an outer diameter is left partially. (D process) is punched to form an annular member. In addition, when performing each process of FIG. 10 separately, an annular member may be completely punched in d process. Further, the above steps a to d are preparation steps for the convenience of subsequent processing steps, and may be omitted depending on circumstances.

  Next, a ring-shaped groove is formed by reducing the plate thickness of the annular member on one surface and the other surface of the annular member by pressing. Specifically, as shown in the cross-sectional view, ring-shaped grooves are formed in the pocket central portion on the lower surface of the annular member (step e) and on the inner and outer pockets on the upper surface of the annular member (step f). create. In this embodiment, press working refers to, for example, coining.

  The cage formed by coining has a higher strength than the case where it is formed by bending, and deformation due to processing or heat treatment is extremely small. Even when deformation occurs, it can be corrected by a press temper.

  Next, a plurality of pockets for accommodating the rollers are formed on a surface intersecting the bearing rotation axis of the annular member by punching (step g). In the punching process, one to several pockets may be partially processed, but all pockets may be formed simultaneously. As a result, it is possible to suppress the occurrence of pocket displacement.

  In step g, the first roller contact portion and the second roller contact portion are formed at the same time as the pocket in a positional relationship shifted in the bearing rotation axis direction of the pocket wall surface and the roller rotation axis direction. For example, a first roller contact portion is formed above the center of the pocket, and a second roller contact portion is formed below both ends.

  Next, the roller contact portion is subjected to surface pressing on the contact portion of the roller to form a roller stopper and a roller guide surface. Specifically, as shown in the cross-sectional view, the first roller contact portion includes a first roller stopper that prevents the roller from coming off upward by inserting a tool from below, and a processed surface thereof. A first roller guide surface for guiding the rotation of the rollers is formed (step h).

  As for the second roller contact portion, a second roller guide for preventing the roller from coming out downward by inserting a tool from above, and a second roller guide for guiding the rotation of the roller to the processed surface. Forming a surface (step i).

  In the above embodiment, the example of performing the processing of the second roller contact portion after processing of the first roller contact portion has been shown. However, the present invention is not limited thereto, and the second roller contact portion is processed first, The first roller contact portion may be processed. Moreover, the processing method of a roller stopper part and a roller guide surface is performed by the burnishing etc. which are mentioned later.

  Finally, as a finishing step, the inner diameter is punched to a predetermined size (step j), and the cage is punched from the coil material (step k), thereby completing the thrust roller bearing retainer (step l).

  Each of the above steps (steps a to l) may be performed as separate steps, but may be performed by a progressive press. Thereby, since each process can be performed continuously, productivity can be improved and the product price of a thrust roller bearing can be held down as a result.

  Alternatively, each of the above steps (steps a to l) may be performed by transfer press. In this specification, “transfer press” means that when multiple processing steps are required, the necessary number of stages for performing each step is provided, and processing is performed at each stage while moving the process product by the transfer device. Refers to the method of performing

  Finally, the cage is subjected to heat treatment, for example, carburizing and tempering, or instead of carbonitriding or soft nitriding, to obtain a finished product. The heat treatment may be performed in an atmosphere furnace, but may be performed with a high frequency heat treatment. This eliminates the need for large equipment such as an atmospheric furnace. In addition, processing in a small lot is possible, and manufacturing costs can be reduced.

  Next, a procedure for forming the second roller stopper 15a and the second roller guide surface 15b in the second roller contact portion 15 will be described with reference to FIGS.

The second roller stopper 15a and the second roller guide surface 15b are formed by burnishing as shown in FIG. Specifically, as shown in FIG. 11 (a), the second roller contact portion 15 is placed at a position retracted from the end surface of the work table 18 by a width L ₁ , and the tool 19 is placed on the second roller contact portion 15. processed is set to the overlap from the end face by a width L ₂ position. Thereby, as shown in FIG.11 (b), the 2nd roller stop part 15a and the roller guide surface 15b are formed.

With respect to the second roller contact portion 15 of post processing, as shown in FIG. 12, a second roller guide surface 15b is retracted from the end surface of the second roller contact portion 15 before processing by a width L _2, depressed by the burnishing process the resulting part, the second roller stoppers 15a is formed from the end face of the second roller contact portion 15 before processing protrudes by the width L _1.

  As described above, by forming the second roller guide surface 15b by burnishing, a smooth roller guide surface with low surface roughness can be obtained, so that the contact resistance with the guide surface is reduced, and iron powder due to wear is reduced. Can be suppressed. Further, even under lean lubrication, high lubrication performance can be maintained without causing oil film breakage or the like. As a result, a thrust roller bearing excellent in durability and quietness can be obtained.

By changing the values of the widths L ₁ and L ₂ at the time of machining, it becomes possible to easily adjust the amount of play between the roller and the roller contact portion.

Further, in order to reduce the error of the protruding width L _1, before the burnishing processing step shown in FIG. 10 (h step) it may be provided positioning step.

  In the above embodiment, tool steel or the like is generally used for the tool 19 used for burnishing, but cemented carbide or the like may be used in order to improve the wear resistance of the tool 19.

  In the above embodiment, the example in which the second roller stopper 15a and the second roller guide surface 15b are formed by burnishing has been described. Good.

  Furthermore, the roller stoppers 14a and 15a and the roller guide surfaces 14b and 15b may be formed by surface pressing the corners of the roller contact portions 14 and 15 on the roller contact side. Surface pressing is effective in that the shape of the tool can be simplified.

  In the embodiment shown in FIG. 7, the second roller contact portion 15 is provided at two locations on the inner side and the outer side as viewed in the radial direction of the cage 11, but the second roller stopper 15 a and the second roller guide are provided. The processing of the surface 15b may be performed simultaneously at two locations, or may be performed separately one by one.

  Moreover, in said embodiment, although the method to form the 2nd roller stopper part 15a and the 2nd roller guide surface 15b in the 2nd roller contact part 15 was shown, the tool 19 is applied from the bottom also about a 1st contact part. Thus, the first roller stopper 14a and the first roller guide surface 14b can be formed by the same method.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used in a method of manufacturing a thrust roller bearing used for an automatic transmission, a compressor, or the like.

It is a schematic plan view of the cage for thrust roller bearings. It is the AA 'sectional view in Drawing 1 of the conventional cage for thrust roller bearings. It is a schematic plan view of the pocket part of the conventional cage for thrust roller bearings. It is BB 'sectional drawing in FIG. 2 of the conventional cage for thrust roller bearings. FIG. 3 is a cross-sectional view taken along the line BB ′ in FIG. 2 of a cage for a thrust roller bearing having a reduced roller diameter. It is CC 'sectional drawing in FIG. 1 of the cage for thrust roller bearings concerning one Embodiment of this invention. It is a schematic plan view of the pocket part of the cage for thrust roller bearings concerning one Embodiment of this invention. It is an AA 'sectional view in Drawing 1 of a cage for thrust roller bearings concerning one embodiment of this invention. It is DD 'sectional drawing in FIG. 8 of the cage for thrust roller bearings concerning one Embodiment of this invention. It is a figure which shows the manufacturing process of the cage for thrust roller bearings concerning one Embodiment of this invention. It is an illustration sectional view showing a processing method of a roller stop part and a roller guide surface. It is an expanded sectional view of the roller contact part before and after forming the roller stopper and the roller guide surface.

Explanation of symbols

  1,11 Cage, 2,13 Pocket, 3,14a, 15a Roller stopper, 4,14b, 15b Roller guide surface, 5,17 rollers, 12 Ring-shaped groove, 14,15 Roller contact portion, 16 Roller non-contact Part, 18 working table, 19 tools.

Claims (6)

An annular member is formed by punching from a steel plate,
On one side and the other side of the annular member, a ring-shaped groove is formed by reducing the plate thickness by pressing,
A plurality of pockets for accommodating rollers on a surface intersecting with the bearing rotation axis of the annular member, and a positional relationship shifted on the wall surface of the pocket as viewed in the bearing rotation axis direction and the roller rotation axis direction A method for manufacturing a retainer for a thrust roller bearing, wherein the first roller contact portion and the second roller contact portion are formed by punching. The first roller contact portion includes a first roller stopper for preventing the roller from coming off in one direction by pressing the corner portion on the contact side of the roller, and a first for guiding the rotation of the roller. Forming a roller guide surface,
The second roller contact portion includes a second roller stopper for preventing the roller from coming off in the other direction by pressing the corner portion on the contact side of the roller, and a second for guiding the rotation of the roller. The method of manufacturing a cage for a thrust roller bearing according to claim 1, wherein the roller guide surface is formed.   The method for manufacturing a retainer for a thrust roller bearing according to claim 2, wherein in the surface pressing process, the first roller contact portion and the second roller contact portion are processed in separate steps.   The method for manufacturing a retainer for a thrust roller bearing according to claim 2, wherein the surface pressing is burnishing.   The method for manufacturing a retainer for a thrust roller bearing according to any one of claims 1 to 4, wherein the pressing is coining.   The method for manufacturing a thrust roller bearing retainer according to any one of claims 1 to 5, wherein the thrust roller bearing retainer is manufactured by a progressive press.

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