JP2539750B2 - Method of manufacturing inner ring and outer ring of bearing - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method of manufacturing an outer ring and an inner ring of a bearing.

[0002]

2. Description of the Related Art FIG. 1 is a process diagram showing the most advanced small diameter bearing manufacturing method at present. The manufacturing method shown in this figure manufactures an outer ring and an inner ring in the following steps. (1) Bar material 1 which is a raw material for bearings is forged by a forging machine 2
Forging to form a disc with a hole in the center. After that, it is heat-treated and annealed. Raw materials that have undergone this treatment are transported to a processing plant. (2) The disc-shaped raw material 3 transported to the processing factory is ground to the widths of the side surfaces of the outer ring portion and the inner ring portion. In this step, the width of the raw material 3 is processed to be equal to the width of the finished outer ring 5 and the inner ring 6. (3) The outer diameter surface of the raw material 3 is polished. In this step, the outer diameter of the raw material 3 is processed to be equal to the outer diameter of the finished outer ring 5. (4) The inner diameter surface of the raw material 3 is turned. In this step, the inner diameter of the raw material 3 is turned to be equal to the inner diameter of the finished inner ring 6. By the way, in this specification, "turning" is used in a broad sense including polishing. (5) The outer peripheral corner and the inner peripheral corner are turned to form a round surface. (6) The groove 4 is turned on one side of the raw material 3 in order to separate the outer ring and the inner ring. The width of the groove 4 is determined such that the inner diameter of the outer ring separated by the groove 4 and the outer diameter of the inner ring are approximately the dimensions of the finished product. (7) The raw material 3 is reversed and the groove 4 is also turned on the opposite surface. (8) The outer ring is stopped and the inner ring is pressed to separate the outer ring and the inner ring. (9) The outer raceway 7 is turned on the inner surface of the outer ring. (10) The outer groove 9 for fitting the bearing seal is turned on both sides of the outer ring. (11) The inner raceway 8 is turned on the outer peripheral surface of the separated inner ring. (12) Turn the outer peripheral surface of the inner ring to make the inner ring a finished product.

The outer ring 5 and the inner ring 6 processed in the above steps are races whose processing accuracy is on the order of ± 4/100 mm. The races which are the outer ring and the inner ring processed to this precision are carried to a bearing assembly plant, quenched and polished, and finished to the precision of 1/1000 mm to be assembled as a bearing. In the present specification, the finished product of the outer ring and the inner ring means a state before being transported to a bearing assembly factory, that is, a state before being polished and processed to a predetermined accuracy.

[0004]

As described above, in the method for manufacturing the outer ring and the inner ring of the small diameter bearing, the raw materials cannot be effectively used, and the amount of chips generated increases. Can not be solved in principle. Disc-shaped raw material 3
This is because the groove 4 is turned to separate the outer ring 5 and the inner ring 6. Bearings are basic components often used in many mechanical devices. Therefore, it is extremely important to be able to mass-produce inexpensively. In the above-mentioned conventional processing method, each processing step has been thoroughly examined, and the manufacturing cost has been reduced almost to the limit. Therefore,
It is extremely difficult to improve the conventional method and reduce the manufacturing cost.

In order to reduce the cost of the outer ring and the inner ring,
Raw material costs need to be reduced to reduce the processing costs. The present inventors have focused on cutting and removing a considerable amount of metal when turning a groove. This turning process not only reduces the use efficiency of the raw material by increasing the number of portions where the raw material cannot be used effectively, but also generates a lot of chips that are troublesome to discard. If the outer ring and the inner ring can be manufactured by omitting this turning step, the use efficiency of raw materials can be improved and the amount of chips generated can be significantly reduced. Therefore, the raw material cost can be reduced, and the processing cost can be reduced as a whole.

The outer ring and inner ring should not be scraped
The method of separation is described in JP-A-52-119463.
It is described in the report. Manufacture of the bearings described in this publication
The manufacturing method is to manufacture the inner ring and the outer ring in the process shown in FIG. (1) The raw material 20 is processed into a flat shape. (2) Flat material is formed into a bottomed shape with a recess
I do. The material processed into this shape has an inner ring at the bottom.
Therefore, the tubular part becomes the outer ring. The outer diameter and inner diameter of the cylinder are
Machined to have the same diameter and inner diameter. Furthermore, the height of the entire material
Is machined to the same height as the outer ring. (3) For the inner part of the tubular part of the material processed into the bottomed shape
With a cutting line that extends in the axial direction, cut into the bottom part and the cylinder part,
The outer ring is formed and the inner ring is separated. Furthermore, in this process,
A ring that punches the center from the bottom to make an inner ring
The material 21 is formed. When forming the annular material 21,
The punched circular part is discarded as scrap. (4) The annular material 21 has an outer diameter larger than that of the inner ring and
The inner diameter is smaller than the ring. In addition, ring material
Is thinner than the inner ring. Predetermined thin annular material
The inner ring 22 having the outer diameter, inner diameter, and thickness is processed.

The manufacturing method described in this publication is based on the raw material
The outer ring and inner ring can be separated so that
There are features. However, this manufacturing method
To eliminate the scrap that can occur when separating the inner ring
In order to manufacture the inner ring from an annular material that has been processed into a thin plate,
Need to In other words, the inner ring is made of thin annular material.
It needs to be processed. The outer diameter of the annular material processed into the inner ring
Is equal to the inner diameter of the outer ring and the outer ring and inner ring are separated
This is because there is no scrap that can be made. Thin ring
It is extremely difficult to process a blank into an inner ring. Toku
, The bearing uses a hard metal material with a high carbon content
Therefore, the annular material pressed into a thin plate is
In later processing, thicken and reduce the outer diameter to thicken the whole.
Is actually quite difficult. Furthermore, for bearings
The extremely high reliability is required, and the thin annular material is used.
Thick, making the outer diameter small making it extremely difficult
It It is a thin annular material that is thickly processed to reduce the outer diameter.
In the difficult process of rolling, the inner ring of the rolling surface of the steel ball
There is no possibility of cracks on the outer peripheral surface.
Because. In the bearing manufacturing process, even if
Even if one defective product occurs every 10,000
Need to be removed reliably, and its selection is extremely difficult
It is.

Rather than making the inner ring a thin annular material,
Separate the completed inner ring and outer ring into almost the same shape
Methods are also described. This manufacturing method is as shown in FIG.
The raw material 20 was processed to have the same thickness as the outer ring and the inner ring.
After that, punch out the center with a size equal to the inner diameter of the inner ring,
In addition, the outer ring and the inner ring are processed into a shape with a step, and the outer ring and
The outer ring and the inner ring are separated by removing the disc between the inner rings. This
The outer ring and the inner ring, which are separated by
No need to process. However, this method is
I couldn't eliminate the disc-shaped scrap
Absent. Therefore, the raw materials cannot be used effectively.

That is, in the conventional method, the outer ring and the inner ring are separated.
Can scraps occur when separated or scrap
The inner ring is difficult to machine.
Therefore, there is a drawback that high-quality inner rings cannot be mass-produced at low cost.
is there.

The present invention was developed for the purpose of eliminating these adverse effects . An important object of the present invention is
It is an object of the present invention to provide a method of manufacturing an inner ring and an outer ring of a bearing which can improve the use efficiency of raw materials and reduce the cost of raw materials by punching the inner ring from the outer ring and rolling and forming the same.

The outer diameter of the inner ring separated by punching is equal to the inner diameter of the separated outer ring. This is because unlike the conventional manufacturing method, the outer ring and the inner ring are not separated by turning a groove having a predetermined width between the outer ring and the inner ring. The present invention, both the outer ring and the inner ring that have been separated by punching, by rolling, the outer diameter and the inner diameter to a predetermined size, further, the turning amount is extremely reduced to significantly reduce the amount of chips generated. It is an object of the present invention to provide a method of manufacturing an inner ring and an outer ring of a bearing which can be reduced.

Still another important object of the present invention is to
It is an object of the present invention to provide a method of manufacturing an inner ring and an outer ring of a bearing, which can reduce the number of machines to be processed to save labor and efficiently process the outer ring and the inner ring to mass-produce a race at low cost.

[0013]

In order to achieve the above-mentioned object, the manufacturing method of the present invention manufactures an outer ring and an inner ring as follows. In the manufacturing method of the present invention, a metal raw material formed in a disk shape having an outer diameter smaller than that of the outer ring to be a product is punched by a punching machine, and is smaller than the outer diameter of the finished inner ring which is a finished product. Separate the inner ring of outer diameter from the outer ring.

The surfaces of the separated inner ring and outer ring are removed and smoothed.

The outer ring and the inner ring separated by punching are
The outer diameter and the inner diameter are not the same as when completed, unlike the outer ring and inner ring that have been separated by turning the groove as in the past. An outer ring and an inner ring whose outer and inner diameters are not completed dimensions are rolled and formed. In this step, the outer diameter and inner diameter of the outer ring are molded to the outer diameter and inner diameter of the completed outer ring, and the outer diameter and inner diameter of the inner ring are molded to be the same as the outer diameter and inner diameter of the completed inner ring.

[0016]

According to the method of manufacturing the inner ring and the outer ring of the bearing of the present invention, instead of turning the disc-shaped raw material to separate the outer ring and the inner ring as in the conventional case, the outer ring and the outer ring are punched to form the outer ring. Separated from the inner ring. As described above, the method of the present invention does not turn the groove, so that no chips are generated. The conventional method of turning and separating the groove separates the raw material into an outer ring, an inner ring and a considerable amount of chips. In the manufacturing method of the present invention, the raw material is punched to separate it into an outer ring and an inner ring, and chips are not generated in the step of separating. Therefore, the raw material can be effectively used without waste, and the outer ring and the inner ring can be separated.

However, the outer diameter and the inner diameter of the punched outer ring and inner ring are not the dimensions of the finished race. This is because the outer diameter of the inner ring becomes equal to the inner diameter of the outer ring in the punched state. The outer ring and the inner ring having different outer diameters and inner diameters are roll-molded to have the same size as the finished race. In the rolling forming, the outer ring and the inner ring are pressed and formed, not turning, so that no chips are generated. Further, when the molding is performed by this method, at the same time as molding the outer diameter and the inner diameter to a predetermined dimension, it is possible to provide a track or the like and round chamfer or the like. Therefore, when compared with the conventional turning method,
The track or the like can be provided simply and easily by molding to a predetermined size in a short time.

[0018]

Embodiment An embodiment of the present invention will be described below with reference to FIG. However, the following examples exemplify a method for embodying the technical idea of the present invention, and specify the method for manufacturing the inner ring and the outer ring of the bearing of the invention as the following method. Not.

(1) Step of cutting bar material to a predetermined thickness As shown in FIG. 3, a cutter 10 is used to cut a cylindrical bar material 1 to a predetermined thickness, and a raw material 3 for a bearing is cut.
And The bar material 1 has a spheroidized structure and has a hardness of HRB = 90 as measured by Rockwell (B scale).
Use SUJ2 which is ~ 91. The bar material 1 contains the following components in addition to iron. C ... 0.95 to 1.10 wt% Si ... 0.15 to 0.35 wt% Mn ... 0.5 wt% or less P ... 0.025 wt% or less S ... 0.020 wt% or less Cr ... 1.30 1.60 wt% Mo ... 0.08 wt% or less Ni ... 0.25 wt% Cu ... 0.25 wt% or less For the bar material 1, SUJ3 to 5 can be used instead of SUJ2. The cutter 10 for cutting the bar material 1 has a rotary shaft 1
The circular saw blade 10B is fixed to 0A at a predetermined interval. The rotary shaft 10A of the cutter 10 is arranged parallel to the bar material 1, and the rotating circular saw blade 10B is brought close to the bar material 1 to cut the bar material 1. The outer diameter of the bar material 1 is designed such that it can be punched and then roll-molded to form an outer ring and an inner ring of predetermined dimensions. For example, the outer diameter of the finished outer ring is 4
The outer diameter of the bar material used to make the race to be 0 mm is 31 m.
m.

(2) Process of punching raw material by punching machine As shown in FIG. 4, raw material 3 is punched by using a punching machine.
Then, the center hole 11 of the inner ring is punched. Then, the bush 12 is fitted into the center hole 11, and the raw material 3 is punched using the punching machine shown in FIG. 5 to separate the outer ring and the inner ring. The punching machine has a recess 1 into which a raw material 3 can be fitted.
A die 13 having 3A and a punch 14 for punching the center of the raw material 3 are provided. Further, the punching machine uses the punch guide 1 for inserting the raw material 3 into the recess 13A of the die 13.
7 is provided. The punch 14 punches the raw material 3 while the punch guide 17 presses the raw material 3.
The recess 13A of the die 13 is designed to have an inner diameter slightly larger than the outer diameter of the raw material 3 and prevents the outer shape of the raw material 3 from being deformed during punching. This punching machine punches the raw material 3 with a punch 14 to form a center hole 11, and further separates the raw material 3 into an outer ring and an inner ring. The outer shape of the inner ring to be punched is, for example, 22 mm in the outer diameter of the inner ring to be punched when manufacturing a race in which the outer diameter of the completed inner ring is 25 mm.

(3) Heat Treatment of Outer Ring and Inner Ring The outer ring and inner ring punched by the punching machine are hardened due to work hardening and residual stress. When the hardened outer ring and inner ring are cold-rolled and roll-formed, fine cracks occur on the surface, and they are deformed and cannot be formed into a perfect circle. To prevent cracking and deformation in cold rolling,
The outer ring and the inner ring are heat treated. During heat treatment, the outer ring and inner ring are heated to 780 ° C for 3 hours, and the heating temperature is changed to 700 ° C.
Let cool for 3 hours. Also, the heating temperature is 800
C., heating time may be 10 minutes, and this may be air-cooled for heat treatment. Instead of air cooling, it is also possible to heat and cool the outer ring and the inner ring by furnace cooling.

The work hardening and residual stress generated in the outer ring and the inner ring when punched by the punching machine are 600 ± 25.
After heating to ℃, by air cooling or furnace cooling,
Can be removed almost completely. However, in order to further reduce the hardness by annealing the outer ring and the inner ring, they are heated to 730 ° C. or higher and air-cooled or furnace-cooled. Therefore, the outer ring and the inner ring to be heat-treated are preferably heated to 700 ° C to 900 ° C, more preferably 730 ° C to 900 ° C. Set the heating temperature to 700 ° C or higher, preferably 730 ° C or higher,
Further, increasing the cooling time of the heated outer ring and inner ring is effective in softening. However, heating to 900 ° C. or higher is not preferable because it destroys the spheroidization of the tissue.

(4) Step of Turning Heat Treated Outer Ring and Inner Ring The heat treated outer ring and inner ring are heated to form a decarburized layer on the surface. The thickness of the decarburized layer is 5/100 to 8/100 mm. In order to remove this decarburized layer, the surfaces of the outer ring and the inner ring are turned. For the outer ring and the inner ring, the inner diameter is turned, the outer diameter is turned or polished, and the width is polished. In order to completely remove the decarburized layer, the outer ring and the inner ring have their surfaces turned by 10/100 mm or more.

(5) Step of Roll Forming Outer Ring and Inner Ring The outer ring and inner ring whose surfaces have been turned are roll formed by cold rolling using a cold rolling forming machine. The outer ring and the inner ring formed by rolling are finished to the dimensions of the finished outer ring and the inner ring.

As shown in FIG. 6, the cold rolling forming machine has a mandrel 15 and a forming roll 16 which are inserted into the centers of the inner ring and the outer ring. The mandrel 15 is inserted into the inner diameter of the outer ring or the inner ring, and the forming roll 16 presses the outer periphery of the mandrel 15 and rolls it to cold-roll the outer ring and the inner ring. For example, the inner diameter is 1
Mandrel 15 for rolling and forming the inner ring of 0.5 mm
Is the maximum outer diameter of the part that rolls the inner diameter of the inner ring 10.3m
m and the minimum outer shape is about 8 mm. The outer ring and the inner ring are
Roll forming is carried out to finish the surfaces A to H in FIG. That is,
Finish the A, B, C, D surfaces of the outer ring and the E, F, G, H surfaces of the inner ring. The mandrel 15 that finishes the outer ring by rolling and forming into this shape has a ridge that forms an outer race on the outer ring. The forming roll 16 for rolling and forming the inner ring into this shape is
It has a ridge that forms the inner track. Thus, when the inner race is roll-formed to form the inner race, and the outer race is formed when the outer race is roll-formed, the material of the portion removed as the race is effectively used. However, it goes without saying that the inner raceway and the outer raceway can be processed by turning after rolling and forming.

(6) Step of turning to finish the outer ring and the inner ring to a predetermined size The roll-formed outer ring is turned to a predetermined size by turning and has a groove for fitting a seal of a bearing. Form by turning. However, the groove into which the seal is fitted can also be formed by roll forming. The outer ring and the inner ring in which the shape of the groove into which the seal is fitted are complicated can be formed by rolling forming an incomplete groove, and the groove can be turned into a groove having a designed shape. If the outer shape of the inner ring cannot be formed as designed by roll forming, the outer shape of the inner ring is turned to form a predetermined shape.

[0027]

The method of manufacturing the inner ring and the outer ring of the bearing of the present invention is characterized in that the material yield can be improved and the raw material cost can be reduced. This is because, in the manufacturing method of the present invention, a disc-shaped raw material having a smaller diameter than the outer diameter of the outer ring is punched to separate the outer ring and the inner ring, which are then roll-formed into a predetermined size. . In the manufacturing method of the present invention in which the outer ring and the inner ring are punched and separated from each other, the groove is turned and separated between the outer ring and the inner ring as in the conventional method , or as shown in FIG.
The outer ring and the inner ring are connected by a thin metal part.
It is not necessary to remove a part of the raw material as in the method of working . Therefore, almost all the raw materials can be effectively used for the outer ring and the inner ring. Therefore, there is a feature that the amount of raw materials actually used can be reduced and the raw material cost can be reduced. By the way, when manufacturing an outer ring having an outer diameter of 40.17 mm and an inner ring having an outer diameter of 25 mm as a race of a model number 6203 bearing, the conventional method requires the outer diameter of the raw material to be 4 mm.
0.8mm, inner diameter 15.30mm, width 12.7mm
I needed to. The weight of this raw material is 124.24.
It becomes g. On the other hand, according to the method of the present invention, the bar material having an outer diameter of 31 mm has a pitch of 15 mm including the allowance of the saw blade (the allowance of the saw blade is 2 mm, and the width of the cut raw material is 13 mm). ) Can be cut to produce outer and inner races. This raw material uses 88.95 g of bar material. Therefore, the raw material can be reduced to 35.29 g, which is about 28% less.

FIG. 8 (a) shows the raw materials of the bearing race manufactured by the conventional method and the outer diameters of the outer race and the inner race. FIG. 8 (b) shows raw materials of the bearing race manufactured by the method of the present invention and outer diameters of the outer race and the inner race. As shown in this figure, the conventional method requires the outer diameter of the raw material to be approximately equal to the outer diameter of the finished outer ring.
The manufacturing method of the present invention uses a raw material having a small outer diameter,
An outer ring and an inner ring that are larger than the raw material can be manufactured, and the yield of the raw material can be improved.

Furthermore, according to the method for manufacturing the inner ring and the outer ring of the bearing of the present invention, the outer ring and the inner ring are not punched into a predetermined size as in the prior art, but are punched. Since the outer ring and inner ring that have been separated are roll-formed and finished to a predetermined size, there is a feature that the amount of chips can be extremely reduced compared to the conventional method. Therefore, there is a feature that the processing of the chips does not take time and the working environment can be remarkably improved.

Further, in the method for manufacturing a bearing race according to the present invention, the outer ring and the inner ring, which have been punched and separated, are roll-formed to a predetermined size, so that the turning process can be significantly simplified. Therefore, the automation line of the processing device can be simplified and the skill period of the operator can be shortened.
In addition, workers are not required to have a high level of skill,
Achieve the feature that the failure rate is reduced and the bearing races can be mass-produced efficiently.

Further, the outer ring and the inner ring manufactured by the method of the present invention have a feature that the inner diameter and the outer diameter can be set to predetermined dimensions by roll forming, and the uneven thickness accuracy can be increased.

Furthermore, a method of manufacturing the bearing of the present invention
The law creates scrap when separating the outer and inner rings.
The outer ring and inner ring are extremely high quality
It has the feature that it can produce a large amount of sauce. It is the basis of the present invention.
The manufacturing method of the ring is the same as the conventional method shown in FIG.
In addition, it is necessary to process the thin annular material thickly to manufacture the inner ring.
Because there is no. The manufacturing method of the present invention separates the outer ring from the inner ring.
The outer diameter of the inner ring so that scrap does not occur when
Equal to the inner diameter of the outer ring, but
The inner ring is thin because both are roll-formed to increase the outer diameter.
It is not necessary to use an annular material. As shown in FIG. 9, the axial direction
Ring material with a significantly wider radial width than the thickness of
Is crushed in the radial direction to form an inner ring with a specified outer diameter.
The conventional manufacturing method is to process a thin annular material into a thick inner ring.
It is extremely difficult to produce high-quality bearings in large quantities.
Is actually almost impossible. Manufacturing method of the present invention
Is the inner diameter of the separated outer ring and the outer diameter of the inner ring are almost equal
However, after that, both the outer ring and the inner ring are largely rolled and formed.
Therefore, it is not necessary to process the inner ring from a thin annular material.
Therefore, make sure that the outer and inner rings cannot be scrapped.
Despite being separable, many high quality laces can be
This is true for the bearing manufacturing method, which enables mass production.
To achieve the ideal features.

[Brief description of drawings]

FIG. 1 is a process diagram showing a manufacturing process of a conventional bearing.

FIG. 2 is a process diagram showing a manufacturing process of a bearing according to an embodiment of the present invention.

FIG. 3 is a front view showing a state in which the bar material is cut into a disc shape.

FIG. 4 is a cross-sectional view showing a state in which a raw material is punched by a punching machine to punch a center hole of an inner ring.

FIG. 5 is a cross-sectional view showing a state in which a punching machine punches a raw material and separates it into an outer ring and an inner ring.

FIG. 6 is a cross-sectional view showing a state in which an outer ring and an inner ring that have been punched are roll-formed.

FIG. 7 is a cross-sectional view showing a cross section of an outer ring and an inner ring which are roll-formed.

FIG. 8 is a cross-sectional view showing raw materials for manufacturing a bearing race by a conventional method and the method of the present invention and outer diameters of an outer ring and an inner ring.

[Figure 9] Separate the outer and inner rings to prevent scrapping.
Sectional drawing which shows the conventional manufacturing method to separate

FIG. 10 Conventional manufacturing of races by separating the outer and inner rings
Sectional view showing the manufacturing method of

[Explanation of symbols]

1 ... Bar material 2 ... Forging machine 3 ... Raw material 4 ... Groove 5 ... Outer ring 6 ... Inner ring 7 ... Outer track 8 ... Inner track 9 ... Outer groove 10 ... Cutter 10A ... Rotating shaft 10
B ... Circular saw blade 11 ... Center hole 12 ... Bushing 13 ... Mold 13A ... Recessed portion 14 ... Punch 15 ... Mandrel 16 ... Forming roll 17 ... Punch guide 20 ... Raw material 21 ... Annular material 22 ... Inner ring

Claims (1)

(57) [Claims] 1. A metal raw material, which is formed into a disk shape and has an outer diameter smaller than that of a product outer ring, is punched by a punching machine and is smaller than the outer diameter of a finished inner ring which is a finished bearing. Complete the outer and inner diameters of the outer ring by separating the inner ring with the outer diameter from the outer ring, removing the surfaces of the separated inner ring and outer ring, and rolling the inner ring and outer ring with the removed surface A method of manufacturing an inner ring and an outer ring of a bearing, characterized in that the outer diameter and the inner diameter of the outer ring are formed so that the outer diameter and the inner diameter of the inner ring are the same as the outer diameter and the inner diameter of the completed inner ring.