JP2001165170A - Method of manufacturing rolling bearing cage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a rolling bearing cage with a specified wall thickness from a steel plate with a thicker plate thickness than the specified wall thickness. SOLUTION: A punched plate 21 of 2.9 mm in plate thickness discharged in a process of manufacturing a large-sized tapered roller bearing cage 10 is used as a blank, and the plate thickness is thinned by an ironing-spinning method to manufacture a tapered roller bearing cage 20 of 2.0 mm in wall thickness smaller than the tapered roller bearing cage 10. In this case, a wall thickness decrease rate ηis 31.0%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a cage for a rolling bearing, and more particularly to a method for manufacturing a cage for a rolling bearing by cold plastic working.

[0002]

2. Description of the Related Art Roller bearing retainers have heretofore often been manufactured from a blank formed by punching a steel plate into a circular shape by drawing such as drawing pressing or drawing spinning. For example, a cage cage for a tapered roller bearing has been manufactured from a steel plate through the following steps. (1) A plate removing process for punching a disk (blank) from a steel plate. (2) A drawing process in which the disk is subjected to drawing as described above, and an outer peripheral portion of the disk is bent to form a cup shape (conical frustum shape). (3) A cutting step in which the opening end of the cylindrical portion of the cup-shaped molded product is cut with a cutting bite to make it smooth. (4) A punching step of punching a circular hole by punching a bottom plate portion of a cup-shaped molded product. (5) A pocket forming step of providing a plurality of rectangular holes (pockets) along the circumferential direction in the cylindrical portion of the cup-shaped molded product. (6) A pillar forming step for finishing the pillars of the cage.

[0003] The thickness of the rolling bearing cage is substantially proportional to the size of the rolling bearing used, that is, the size of the rolling bearing cage, and is almost univocally determined according to the size of the rolling bearing cage. It is decided to be. Therefore, when manufacturing the rolling bearing cage as described above, according to the size of the rolling bearing cage, to select a steel plate having a thickness substantially equal to the thickness of the rolling bearing cage to be manufactured, A blank was punched from the steel plate.

[0004]

However, in the above-described method of selecting a steel plate to be used according to the thickness of the rolling bearing cage, the rolling bearing cages of different sizes have different thicknesses. Therefore, when it is necessary to manufacture rolling bearing retainers of various sizes, it is necessary to prepare steel plates having a plurality of thicknesses according to the sizes.

In addition, if a steel plate having a thickness matching the thickness of the rolling bearing cage to be manufactured is manufactured by rolling the steel plate in advance, and the rolling bearing cage is manufactured using the steel plate. Since a steel plate having a small thickness can be manufactured from a steel plate having a large thickness, the types of steel plates to be prepared can be reduced. However, in this case, since a rolling process of the steel plate is required, there are problems such as an increase in the manufacturing cost of the cage for the rolling bearing and an increase in the time required for the manufacture.

In the punching step of the manufacturing process, a circular steel plate is discharged when a circular hole is formed.
Since this disk (hereinafter, referred to as a punched plate) has a smaller diameter than a disk (blank) for manufacturing a cage for a rolling bearing, a cage for a rolling bearing smaller than the cage for a rolling bearing. Is considered to be usable as a blank for the manufacture of small rolling bearings, but since its thickness is too thick for the manufacture of small rolling bearing cages, it was discarded as scrap without being used as a blank .

Accordingly, the present invention solves the above-mentioned problems of the conventional method for manufacturing a rolling bearing cage, and reduces the thickness of a rolling bearing cage having a predetermined thickness to a thickness greater than the thickness. It is an object of the present invention to provide a method for manufacturing from a steel sheet.

[0008]

In order to solve the above problems, the present invention has the following arrangement. That method of manufacturing a rolling bearing cage of the present invention, there is provided a method of producing the rolling bearing retainer having a predetermined thickness t ₁ of a steel plate of larger thickness t ₀ than the thick t _1, the steel plate At least a portion of the thickness t ₀ by cold plastic working method thinned to the thickness t _1, the thinner, the formula eta = {(t ₀ -t of
₁ ) / t ₀ ｝ × 100 (%)
Is set to 40% or less.

[0009] With such a configuration, even when thicker plate thickness t ₀ of the steel sheet than the thickness t ₁ of the rolling bearing retainer of manufacturing, the steel sheet was thinned by cold plastic working method The rolling bearing cage can be manufactured by processing to a desired thickness, so that it is not necessary to select a steel plate according to the thickness t ₁ of the rolling bearing cage to be manufactured, and a steel plate of one type Can manufacture rolling bearing retainers having various thicknesses (sizes).

[0010] Further, in order to reduce the kinds of necessary steel plates, the steel plates are rolled in advance to produce steel plates having a thickness suitable for the thickness t ₁ of the rolling bearing cage to be manufactured. There is no need to adopt a method of manufacturing a rolling bearing cage by using it.Therefore, the problem of increasing the manufacturing cost of the rolling bearing cage by rolling the steel plate and increasing the time required for manufacturing Etc. do not occur.

Further, according to the method for manufacturing a cage for a rolling bearing of the present invention, a waste material (a punched plate discharged in a punching step of the manufacturing process) discharged in a manufacturing process of a large-sized rolling bearing cage is manufactured. By using it as a blank, it is possible to manufacture a rolling bearing cage smaller than the large rolling bearing cage. Therefore, in the production of cages for rolling bearings, it is possible to improve the material yield,
Cost reduction and effective use of resources can be achieved.

However, the thickness reduction rate η is preferably 40% or less. When the wall thickness reduction rate η exceeds 40%, processing defects such as a reduction in processing accuracy of the outer shape of the cage for the rolling bearing and a roughening of the cold-worked part of the cage in the cage are caused. It is easy to occur. The thickness reduction rate η may be 0%. The working method adopted as the cold plastic working method in the present invention is not particularly limited as long as the thickness of the steel sheet can be reduced,
An ironing method such as an ironing spinning method is preferably used.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a cage for a rolling bearing according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a process diagram showing one embodiment of a method for manufacturing a cage for a rolling bearing according to the present invention.
Waste material (punched plate 2) discharged in the process of manufacturing the tapered roller bearing retainer 10 (hereinafter, referred to as the first retainer) (the manufacturing process of the first retainer shown in FIG. 1A).
A step of manufacturing a tapered roller bearing retainer 20 (hereinafter, referred to as a second retainer) smaller than the first retainer 10 by using 1) as a blank (the first retainer shown in FIG. 1B). (Manufacturing process of a double cage).

Tapered roller bearings (inner diameter 90 mm, outer diameter 16
A steel blank having a thickness (t = 2.9 mm) suitable for manufacturing the first retainer 10 for 0 mm) is punched, and the disc blank 11 is stripped (plate stripping step). This disk blank 1
1 is drawn by a drawing press working method and formed into a cup shape (drawing step). Next, the opening end of the cylindrical portion 12a of the cup-shaped object 12 is cut by a cutting bit 34 to make the edge smooth (cutting step). And cup-shaped material 1
The second bottom plate 12b is punched to form a circular hole 13 (punching step), and a plurality of rectangular holes are further formed in the cylindrical part 12a along the circumferential direction to form a pocket 14 (pocket forming step). Then, the pillars 15 are further formed (pillar forming step) to complete the large first retainer 10. The thickness of the first retainer 10 is set to 2 in both the cylindrical portion 12a and the bottom plate portion 12b.
9 mm.

The punching plate 21, which is a circular steel plate that is discharged when the circular hole 13 is formed by punching the bottom plate portion 12b, is normally discharged in the pocket forming step. Although discarded together with a plurality of rectangular steel plates as scrap, in the present embodiment, since it is used as a disk blank for manufacturing the second retainer 20 for tapered roller bearings (inner diameter 50 mm, outer diameter 90 mm), It is sent to the manufacturing process of the second cage shown in FIG.

The second cage 20 is manufactured in substantially the same manner as the first cage 10. However, since the thickness (2.9 mm) of the punched plate 21 is large as the thickness of the small-diameter second retainer 20, it is necessary to reduce the thickness to an appropriate thickness. The circular punched plate 21 (diameter 116.0 mm) discharged in the manufacturing process of the first cage 10 is drawn as a disk blank by a drawing spinning method, and formed into a cup shape (drawing step). The condition of the drawing spinning at this time is 0.1 mm / rev. Then, Yushiroken EC-50 (manufactured by Yushiro Chemical Industry Co., Ltd.) was used as a lubricating oil.

As one example, FIG. 2 shows a method of forming a cup 22 by drawing and spinning the punched plate 21 using a plate holder 31, a roller 32, and a mandrel (male mold) 33. . That is, the punched plate 21
The mandrel 33 is arranged so that the rotation axis and the axis of the drawing spinning process coincide with each other, and the plate holder 31 and the mandrel 33 sandwich and fix the punching plate 21. While rotating the punching plate 21 and the mandrel 33 about the rotation axis, the roller 32 that is freely displaced in the rotation axis direction and the radial direction of the punching plate 21 is pressed against the outer peripheral portion of the punching plate 21 and plastically deformed. , The outer periphery of the mandrel 33
Curve along the outline of. By such an operation, the punching plate 21 is formed into the same shape as the outer shape of the mandrel 33 to form a cup shape. Note that a spatula may be used instead of the roller 32.

In this step, the punched plate 21 is drawn and formed into a cup shape, and the formed cylindrical portion 22a is subjected to ironing and spinning with a roller 32 to make the cylindrical portion 22a thick. The thickness of the second cage 20 is reduced to a suitable thickness (2.0 mm). When the thickness of the punched plate 21 is within a range suitable for the thickness of the second retainer 20, the cylindrical portion 22a need not be thinned as described above.

Next, the cylindrical portion 22a of the cup-shaped material 22
Is cut by the cutting tool 34 to make the edge smooth (cutting step). Then, the bottom plate portion 22b of the cup-shaped material 22 is punched to form a circular hole 23 (a punching step), and a plurality of rectangular holes are further formed in the cylindrical portion 22a along the circumferential direction to form the pocket 24 (FIG. Pocket forming step). Then, the pillar 25 is further formed (pillar forming step) to complete the small second retainer 20 as shown in FIG.

In FIG. 3, t ₀ is the thickness of the bottom plate portion 22b, that is, the initial thickness of the punched plate 21, and t ₁ is the thickness of the cylindrical portion 22a after ironing and spinning. Therefore, the thickness reduction rate η in thinning by ironing spinning is 31.0% as calculated by the following equation. η = {(t ₀ −t ₁ ) / t ₀ } × 100 (%) The thickness of the bottom plate 22 b of the cup 22 is 2.9 m.
m, but there is a problem in the production or use of the bearing, for example, the caulking force of the cage becomes excessive during the assembly of the bearing, or it is difficult to incorporate the bearing into the housing due to the large cage. In such a case, it is preferable to perform cutting, turning, or the like, so that the thickness is reduced so that the above-described problem does not occur. For example, it may be the thickness t ₁ of the same level as the cylindrical portion 22a '(2.0 mm) as indicated by a dotted line in FIG. In that case, t ₁ ≒ t ₁ ′.

As described above, the circular punching plate 21 discharged in the punching step of the step of manufacturing the first retainer 10, that is, the step of punching the bottom plate portion 12b to form the circular hole 13 is used as a disk blank. Since the second retainer 20 was manufactured by using the same, the material yield was improved by about 50% from the conventional method to about 30%. Thus, resources were saved.

The circular steel plate 26 discharged when the second retainer 20 is manufactured, that is, when the circular hole 23 is formed by punching the bottom plate 22b, is discharged in the pocket forming step. May be discarded together with a plurality of rectangular steel sheets as scrap.
It may be used as a disc blank for manufacturing a roller bearing cage smaller than zero. that way,
It is possible to further improve the material yield.

However, when the difference between the thickness of the disk blank and the thickness after thinning by ironing and spinning becomes large (when the above-mentioned thickness reduction rate η becomes large), the completed holding for the rolling bearing is performed. The roundness of the cylindrical part of the vessel decreases,
Processing defects such as roughening of the part of the cage subjected to ironing and spinning are likely to occur. In order to prevent such processing defects from occurring, the thickness reduction rate η is preferably 40% or less.

Further, when the correlation between the diameter Φ of the punched plate 21 and the manufacturing cost of the second cage and the disposal cost when the punched plate 21 was discarded was examined, as shown in the graph of FIG. In the case where the diameter Φ of the sample No. 21 is less than 35 mm, the production cost exceeds the disposal cost. Therefore, the lower limit of the diameter Φ of the punched plate 21 is not particularly limited,
It is preferably at least 35 mm, and more preferably at least 40 mm in order to obtain a sufficient cost merit.

The upper limit of the diameter Φ of the punched plate 21 is not particularly limited. For example, a large-diameter disc for manufacturing a large-sized cage such as a tapered roller bearing cage applied to a bearing having an inner diameter φ of about 600 mm, which is usually manufactured using a steel plate cage. A blank can be used. However, the larger the size of the bearing, the smaller the production quantity tends to be, so that the cost merit tends to be reduced.

From these facts, it can be seen that the thickness reduction rate η is 40%
In the following, it is understood that if the diameter Φ of the punched plate 21 is 40 mm or more, both the processing surface and the cost are favorable. FIG. 5 is a graph simply showing these points. That is, as shown in Table 1, punching plates 21 having various diameters are subjected to the above-described ironing spinning,
The thickness was reduced so as to achieve the respective thickness reduction rates η. In each case, processing defects such as roughening of the skin did not occur, and the cost merit was sufficient. FIG. 5 is a graph in which these results are plotted, and it can be seen that all the results in Table 1 are in a region where no processing defects occur and a sufficient cost merit is generated.

[0027]

[Table 1]

As described above, according to the method for manufacturing a cage for a rolling bearing of the present embodiment, the waste material discharged in the manufacturing process of the large cage for a rolling bearing (first cage 10) (in the punching process). Discharged circular punching plate 21)
Is used as a blank, and a cage for a rolling bearing smaller than the cage for a large rolling bearing (the second cage 2).
0) can be produced. Therefore, it is possible to improve the material yield, reduce costs, and effectively use resources when manufacturing the rolling bearing cage.

In this case, the thickness reduction rate η is 31.0%.
And 40% or less, it is possible to manufacture a rolling bearing retainer without causing any processing problems. Further, since it is not necessary to select the thickness of the steel plate as a material depending on the thickness of the rolling bearing retainer to be manufactured, the types of the prepared steel plates can be reduced, and the stock of the steel plate can be reduced.

Note that the present embodiment is an example of the present invention, and the present invention is not limited to the present embodiment. For example, in the present embodiment, a tapered roller bearing retainer has been described as an example of a rolling bearing retainer, but the method of manufacturing a rolling bearing retainer of the present invention is applicable to various types of rolling bearings. Applicable to retainers. For example, cages for cylindrical roller bearings, cages for spherical roller bearings, cages for deep groove ball bearings, cages for angular ball bearings, and the like.

[0031]

As described above, according to the method for manufacturing a cage for a rolling bearing of the present invention, even if the thickness of the steel plate is thicker than the thickness of the cage for the rolling bearing to be manufactured, the cold rolling can be performed. Since the steel sheet is thinned and processed to a desired thickness by a cold working method, a cage for a rolling bearing can be manufactured.
It is not necessary to select a steel plate as a material depending on the thickness of the rolling bearing cage to be manufactured. Therefore, it is possible to manufacture rolling bearing retainers of various thicknesses (sizes) from a single type of steel plate.

Further, in order to reduce the number of necessary steel sheets, the steel sheets are rolled in advance to produce steel sheets having a thickness suitable for the thickness of the rolling bearing cage to be manufactured. It is not necessary to adopt the method of manufacturing a cage for rolling bearings.Therefore, there is a problem that the rolling cost of a rolling bearing increases due to the rolling of a steel sheet, and a problem that the time required for manufacturing becomes long. Will not occur.

Further, it is possible to manufacture a cage smaller than the large-sized rolling bearing cage by using, as a blank, a punched plate that is waste material discharged in a manufacturing process of the large-sized rolling bearing cage. It is possible. Therefore, in the production of the cage for the rolling bearing, it is possible to improve the material yield, reduce the cost, and effectively use the resources.

Furthermore, since the thickness reduction rate η in manufacturing the rolling bearing cage is set to 40% or less, the processing accuracy of the outer shape of the rolling bearing cage is reduced, or the rolling bearing cage is reduced. The rolling bearing cage can be manufactured without causing any processing problem such as roughening of the portion of the cage subjected to cold plastic working.

[Brief description of the drawings]

FIG. 1 is a process diagram showing one embodiment of a method for manufacturing a cage for a rolling bearing of the present invention.

FIG. 2 is an explanatory view showing a spinning method.

FIG. 3 is a vertical sectional view of a second cage.

FIG. 4 is a graph showing a correlation between a diameter Φ of a punched plate, a manufacturing cost of a second cage, and a disposal cost when the punched plate is discarded.

FIG. 5 is a diagram schematically showing a range of a diameter Φ and a thickness reduction rate η of a punched plate in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 First retainer 11 Disc blank 12a, 22a Tubular part 12b, 22b Bottom plate part 20 Second retainer 21 Punched plate

Claims (1)

[Claims] 1. A method for the rolling bearing retainer for producing a thick steel plate having a plate thickness of t ₀ than the thick t ₁ having a predetermined thickness t _1, at least a portion of the plate thickness t of the steel sheet
₀ is thinned by the cold plastic working method to the above-mentioned thickness t ₁ , and the thinning is performed by the formula η = {(t ₀ −t ₁ ) / t ₀ } × 100.
A method for manufacturing a rolling bearing cage, wherein the thickness reduction rate η defined by (%) is set to 40% or less.