JP2024009556A - Laminate, and manufacturing method of bearing race ring - Google Patents

Abstract

To provide a laminate capable of suppressing deformation of a bearing race ring due to heat treatment and a method for manufacturing the bearing race ring.SOLUTION: A laminate includes a plurality of baskets stacked in front and back directions, and a tray on which the plurality of baskets are mounted. The basket has a basket mounting part capable of mounting a plurality of annular members serving as bearing race rings. The tray has a tray mounting part capable of mounting an annular member. The basket mounting part and the tray mounting part have a honeycomb shape in which a plurality of hexagonal prism-shaped through-holes penetrating in the front and back directions of the basket and the tray. The hexagonal shape of the through-hole constituting the honeycomb shape of the basket mounting part viewed from the front and back directions and the hexagonal shape of the through-hole constituting the honeycomb shape of the tray mounting part viewed from the front and back directions have the same dimensions.SELECTED DRAWING: Figure 1

Description

The present invention relates to a laminate and a method for manufacturing a bearing race.

A bearing ring, which is an annular member, is required to have a desired mechanical strength as a required function. In order to provide mechanical strength to the bearing race, in the manufacturing process of the bearing race, a heat treatment including hardening treatment is performed on an annular member formed of, for example, bearing steel (SUJ2).

For example, Patent Document 1 discloses a continuous heat treatment furnace that performs heat treatment such as carburizing and sintering on an object to be heated.

JP2009-228116A

Bearing races have low rigidity against elliptical deformation, and elliptical deformation may occur in a perfectly circular shaped material obtained by turning a material due to thermal effects due to quenching or phase transformation. As described above, elliptical deformation indicates a phenomenon in which a perfectly circular steel component is distorted into an elliptical shape.

Elliptical deformation of the bearing raceway is evaluated by measuring the roundness of the bearing raceway surface after hardening treatment. The elliptical deformation caused by such heat treatment will be removed by a subsequent grinding process, but if the elliptical deformation of the bearing race is large and the roundness is poor, the amount of grinding must be increased, and the bearing race This led to increased costs in the manufacturing process.

In addition, when heat-treating the annular member which becomes a bearing raceway, it is conceivable to perform continuous heat treatment or batch-type heat treatment, for example. The continuous type is a mass production method in which an annular member is placed on a belt conveyor or the like, and the annular member is heated as it passes through a furnace. The batch type is a method in which an annular member is placed in a basket, and the basket is placed in a fixed furnace (batch type heating furnace) to perform heat treatment (heating and cooling). Batch-type heating furnaces are characterized by the ability to freely adjust the temperature and time depending on the type of bearing rolling element, heating conditions, etc.

However, when an annular member is heat-treated using a batch heating furnace, there has been a conventional problem that the annular member undergoes elliptical deformation and its roundness deteriorates. However, it was not clear what caused this elliptical deformation and deterioration in roundness.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminate and a method for manufacturing a bearing race that can suppress deformation of the bearing race due to heat treatment.

The above object of the present invention is achieved by the following configuration.
(1) Multiple baskets stacked front to back,
a tray on which the plurality of baskets are placed;
A laminate comprising:
The basket has a basket placement part on which a plurality of annular members serving as bearing races can be placed,
The tray has a tray placement part on which the annular member can be placed,
The basket placement part and the tray placement part have a honeycomb shape in which a plurality of hexagonal prism-shaped through holes pass through the basket and the tray in the front and back directions,
The hexagonal shape of the through-holes that form the honeycomb shape of the basket placement section viewed from the front and back directions is the same as the hexagonal shape of the through-holes that make up the honeycomb shape of the tray placement section when viewed from the front and back directions. A laminate characterized in that it has dimensions.
(2) The honeycomb shape of the basket placement portion and the honeycomb shape of the tray placement portion are aligned in phase so that the plurality of through holes overlap each other when viewed from the front and back directions;
The laminate according to (1).
(3) The thickness of the tray placement section in the front and back directions is greater than the thickness of the basket placement section in the front and back directions;
The laminate according to (1).
(4) The thickness of the basket mounting portion in the front and back directions is equal to or greater than the dimension of opposite sides of the hexagonal shape when the through hole is viewed from the front and back directions;
The laminate according to (1).
(5) The thickness of the tray mounting portion in the front and back directions is at least twice the opposite side dimension of the hexagonal shape when the through hole is viewed from the front and back directions;
The laminate according to (1).
(6) A method for manufacturing a bearing raceway, comprising:
In the laminate according to any one of (1) to (5), an annular member placing step of placing the annular member on at least the basket placing part;
a laminate arrangement step of arranging the laminate inside a heating furnace;
a heat treatment step of heat treating the annular member;
A method of manufacturing a bearing race, including:
(7) In the annular member placement step, the annular member is placed on the basket placement section and the tray placement section;
The method for manufacturing a bearing ring according to (6).

According to the present invention, it is possible to provide a laminate and a method for manufacturing a bearing race that can suppress deformation of the bearing race due to heat treatment.

In an embodiment, it is a top view showing the state where a plurality of annular members are arranged on a basket or a tray. FIG. 3 is a cross-sectional view of the laminate. FIG. 3 is a bottom view of the basket. 4 is a sectional view taken along line AA in FIG. 3. FIG. FIG. 3 is a bottom view of the tray. 6 is a sectional view taken along the line BB in FIG. 5. FIG. FIG. 7 is a top view showing a state in which a plurality of annular members are arranged on a basket in a comparative example. It is a schematic sectional view of a heating furnace. FIG. 9 is a view of the cooling section seen from the left and right directions in FIG. 8;

Hereinafter, a method for manufacturing a laminate and a bearing race according to an embodiment of the present invention will be described. In addition, in the following description, the bearing raceway will also be simply referred to as a "bearing race".

The method for manufacturing a bearing ring includes an annular member preparation step of preparing an annular member 1 serving as a bearing ring, an annular member arranging step of arranging the annular member 1 on at least a basket 10, and a plurality of baskets 10 and a plurality of baskets 10. A laminate arrangement step of arranging the laminate 100 composed of the trays 80 to be placed inside the heating furnace 20, a heat treatment step of heat treating the annular member 1 accommodated in the laminate 100, and after the heat treatment step, A grinding step of grinding the annular member 1 is included.

Note that, as described later, the plurality of annular members 1 may be placed not only on the basket 10 but also on the tray 80. In this case, the laminate 100 is placed inside the heating furnace 20 with the annular members 1 placed on the tray 80 in addition to the basket 10 (a laminate arrangement step), and the plurality of annular members 1 are heat-treated. is performed (heat treatment step).

(Annular member preparation process)
In the process of preparing the annular member 1 that will become the bearing ring (inner ring or outer ring), the annular member 1 made of a material that will become the bearing ring is prepared. The material for the annular member 1 is preferably case-hardened steel so that a hardened surface layer can be easily formed by carburizing, nitriding, carbonitriding, or the like. Further, in order to improve hardenability, it is also preferable to add Cr, Mn, etc. as an alloy component to the annular member 1.

(Annular member placement process)
FIG. 1 is a top view showing a state in which a plurality of annular members are arranged on a basket or a tray in an embodiment. In FIG. 1, the shape of the basket or tray is shown in a simplified manner. After preparing the annular members 1, as shown in FIG. 1, a plurality of annular members 1 are arranged on the basket 10 in an annular member arrangement step. Note that, as shown in FIG. 1, the plurality of annular members 1 may be placed not only on the basket 10 but also on the tray 80.

Here, the stacked body 100 constituted by the basket 10 and the tray 80 will be explained with reference to FIGS. 2 to 6. FIG. 2 is a cross-sectional view of the laminate. FIG. 3 is a bottom view of the basket. FIG. 4 is a sectional view taken along line AA in FIG. FIG. 5 is a bottom view of the tray. FIG. 6 is a sectional view taken along line BB in FIG.

As shown in FIG. 2, the laminate 100 includes a plurality of baskets 10 stacked in the front-back direction (vertical direction in FIG. 2) and a tray 80 on which the plurality of baskets 10 are placed on the front side. In FIG. 2, the upper side is the front side of the basket 10 and the tray 80, and the lower side is the back side of the basket 10 and the tray 80. On the other hand, in FIGS. 4 and 6, the upper side is the back side of the basket 10 and the tray 80, and the lower side is the front side of the basket 10 and the tray 80.

The basket 10 and the tray 80 are manufactured by casting or the like, and heat-resistant steel such as SCH22 is exemplified as a material for these materials.

As shown in FIGS. 3 and 4, the basket 10 extends substantially perpendicularly to the front and back directions, and supports a basket placement portion 11 on which the annular member 1 can be placed, and an outer peripheral edge of the basket placement portion 11. It has a basket outer peripheral part 13. The basket placement part 11 and the basket outer peripheral part 13 are integrally molded.

The basket placement part 11 has a honeycomb shape in which a plurality of hexagonal prism-shaped through holes 15 pass through the basket 10 in the front and back directions (thickness direction). The honeycomb shape of the basket placement part 11 is formed by continuously connecting a plurality of flat plate parts 16 extending in the front and back directions. A hexagonal prism-shaped through hole 15 is formed in a portion surrounded by the six flat plate portions 16.

A flat plate portion 16 formed on the outer peripheral edge of the basket placement portion 11 is connected to the basket outer peripheral portion 13 . A hexagonal prism-shaped through hole 15 is formed in the outer peripheral edge of the basket mounting portion 11 in a portion surrounded by the basket outer peripheral portion 13 and the five flat plate portions 16. A pentagonal prism-shaped through hole 15 is formed in a portion surrounded by , and a quadrangular prism-shaped through hole 15 is formed in a portion surrounded by the basket outer peripheral portion 13 and three flat plate portions 16 .

As described above, since the basket placement part 11 has a honeycomb shape, deformation of the basket 10 in the front and back directions (thickness direction) and deformation in the plane direction that is perpendicular to the front and back directions is effectively suppressed. . In particular, since the deformation of the basket 10 in the planar direction is suppressed, the basket 10 will not be deformed even if an external force is applied to the basket outer peripheral portion 13 during transportation of the basket 10 (during transportation of the laminate 100). hard.

Further, the thickness D ₁ of the basket placement portion 11 is set to be equal to or larger than the dimension L ₁ of the opposite side of the hexagonal shape when the through hole 15 is viewed from the front and back directions (D ₁ ≧L ₁ ). Here, the thickness D ₁ of the basket placement part 11 corresponds to the honeycomb shape of the basket placement part 11 and the thickness of the through hole 15 in the front and back directions. Further, the opposite side dimension L ₁ corresponds to the distance between a pair of flat plate portions 16 facing each other among the six flat plate portions 16 constituting the honeycomb-shaped through hole 15 . As the opposite side dimension _L1 , for example, the distance between the largest pair of flat plate parts 16 among the distances between the three pairs of flat plate parts 16 may be adopted.

In this way, the strength of the basket 10 can be improved by increasing the thickness _D1 of the basket mounting portion 11 having a honeycomb shape. In addition, since the honeycomb shape (through holes 15) is thick, heating medium and cooling medium such as air, water, and oil can be rectified during quenching as described later, and the annular member 1 can be uniformly heated and cooled. Deformation of the member 1 can be suppressed.

Approximately L-shaped convex portions 14 are formed at each of the four corners of the back surface 13a of the basket outer peripheral portion 13 so as to protrude toward the back surface side.

As shown in FIG. 2, when a plurality of baskets 10 are stacked, the tip of the convex portion 14 of the upper basket 10 comes into contact with the surface 13b of the basket outer peripheral portion 13 of the lower basket 10. Thereby, a space in which the annular member 1 is arranged is formed between the back surface of the upper basket 10 and the front surface of the lower basket 10.

Further, the tip of the convex portion 14 of the lowest basket 10 among the plurality of baskets 10 comes into contact with a surface 83b of a tray outer peripheral portion 83, which will be described later, of the tray 80. Thereby, a space in which the annular member 1 is arranged is formed between the back surface of the bottom basket 10 and the front surface of the tray 80. Although FIG. 2 shows an example in which the annular member 1 is placed on the tray placement section 81 in addition to the basket placement section 11, the annular member 1 is not necessarily placed on the tray placement section 81. It doesn't have to be done.

As shown in FIGS. 5 and 6, the tray 80 extends substantially perpendicularly to the front and back directions, and supports a tray mounting section 81 on which the annular member 1 can be placed, and an outer peripheral edge of the tray mounting section 81. It has a tray outer peripheral part 83. The tray mounting portion 81 and the tray outer peripheral portion 83 are integrally molded.

The tray mounting portion 81 has a honeycomb shape in which a plurality of hexagonal prism-shaped through holes 85 extend in the front and back directions (thickness direction) of the tray 80 . The honeycomb shape of the tray mounting portion 81 is formed by continuously connecting a plurality of flat plate portions 86 extending in the front and back directions. A hexagonal column-shaped through hole 85 is formed in a portion surrounded by the six flat plate portions 86.

A flat plate portion 86 formed on the outer peripheral edge of the tray mounting portion 81 is connected to the tray outer peripheral portion 83 . A hexagonal prism-shaped through hole 85 is formed in the outer peripheral edge of the tray mounting portion 81 at a portion surrounded by the tray outer peripheral portion 83 and the five flat plate portions 86 . A pentagonal prism-shaped through hole 85 is formed in a portion surrounded by , and a quadrangular prism-shaped through hole 85 is formed in a portion surrounded by the tray outer peripheral portion 83 and three flat plate portions 86 .

In this way, since the tray mounting portion 81 has a honeycomb shape, deformation of the tray 80 in the front and back directions (thickness direction) and deformation in the plane direction that is perpendicular to the front and back directions is effectively suppressed. . In particular, since the deformation of the tray 80 in the planar direction is suppressed, the tray 80 will not be deformed even if an external force is applied to the tray outer peripheral portion 83 during transportation of the tray 80 (transportation of the stacked body 100). hard.

Further, the thickness D ₂ of the tray placement portion 81 is greater than the thickness D ₁ (see FIG. 4) of the basket placement portion 11, and the width across opposite sides L ₂ of the hexagonal shape when the through hole 85 is viewed from the front and back directions. It is set to be twice or more (D ₂ ≧2L ₂ ). Here, the thickness D ₂ of the tray mounting portion 81 corresponds to the honeycomb shape of the tray mounting portion 81 and the thickness of the through hole 85 in the front and back directions. Further, the opposite side dimension L ₂ corresponds to the distance between a pair of flat plate portions 86 facing each other among the six flat plate portions 86 forming the honeycomb-shaped through hole 85 . As the opposite side dimension _L2 , for example, the distance between the largest pair of flat plate parts 86 among the distances between the three pairs of flat plate parts 86 may be adopted.

In this way, by increasing the thickness _D2 of the honeycomb-shaped tray mounting portion 81, the strength of the tray 80 can be improved, and many baskets 10 can be stacked on the tray 80. In addition, since the honeycomb shape (through holes 85) is thick, heating medium and cooling medium such as air, water, and oil can be rectified during quenching as described later, and the annular member 1 can be uniformly heated and cooled. Deformation of the member 1 can be suppressed.

Note that, unlike the basket outer circumferential portion 13, no convex portion is formed on the back surface 83a of the tray outer circumferential portion 83.

Here, the through holes 15 forming the honeycomb shape of the basket placement section 11 have a hexagonal shape when viewed from the front and back directions, and the through holes 85 forming the honeycomb shape of the tray placement section 81 have a hexagonal shape when viewed from the front and back directions. , have the same dimensions. That is, the through-holes 15 forming the honeycomb shape of the basket placement part 11 and the through-holes 85 forming the honeycomb shape of the tray placement part 81 differ only in the thicknesses D ₁ and D ₂ in the front and back directions. , and other dimensions (for example, opposite side dimensions L ₁ and L ₂ ) are the same. In this way, by making the honeycomb shape of the basket mounting part 11 and the honeycomb shape of the tray mounting part 81 the same when viewed from the front and back directions, the annular member 1 can be uniformly heated and cooled during hardening as described later. Therefore, deformation of the annular member 1 can be suppressed.

The honeycomb shape of the basket placement part 11 and the honeycomb shape of the tray placement part 81 are preferably aligned in phase so that the plurality of through holes 15 and 85 overlap each other when viewed from the front and back directions. That is, when the plurality of through-holes 15 of a certain basket placement part 11 are extended in the front and back directions, they completely overlap with the plurality of through-holes 15 of another basket placement part 11 and the plurality of tray placement parts 81 are extended. It is preferable that the through hole 85 completely overlaps with the through hole 85 . In this case, when the laminate 100 is viewed from the front side, the back side of the laminate 100 is visible through the plurality of through holes 15 of the basket mounting section 11 and the plurality of through holes 85 of the tray mounting section 81. be. By adopting such a honeycomb-shaped arrangement relationship of the basket placement part 11 and the tray placement part 81, the annular member 1 can be uniformly heated and cooled during hardening as described below. deformation can be suppressed.

Note that the honeycomb shape of the basket mounting section 11 and the honeycomb shape of the tray mounting section 81 do not necessarily have to be aligned in phase, and may be arranged, for example, shifted by half a pitch.

As shown in FIGS. 1 and 2, in this embodiment, the plurality of annular members 1 are arranged on the basket mounting section 11 and the tray mounting section 81 so as not to contact each other. That is, the minimum distance L in the horizontal direction between adjacent annular members 1 is set to be greater than 0 (L>0).

Moreover, as shown in FIG. 1, it is preferable that the plurality of annular members 1 be arranged in a houndstooth pattern. A positioning member may be used to accurately install the plurality of annular members 1 at predetermined positions in the basket. By adopting the houndstooth arrangement, it is possible to arrange more annular members 1 on the basket 10 while ensuring a gap between adjacent annular members 1.

Note that the arrangement of the plurality of annular members 1 is not particularly limited to a houndstooth pattern, as long as a gap between adjacent annular members 1 can be secured (L>0), and for example, a checkerboard pattern (lattice pattern) may be adopted. I don't mind.

When arranging the plurality of annular members 1 on the basket 10 with gaps between them, the plurality of annular members 1 may be positioned using a jig that is separate from or integrated with the basket 10. The plurality of annular members 1 may be positioned by providing unevenness or the like on the basket 10, and the positioning method is not particularly limited.

FIG. 7 is a top view showing a state in which a plurality of annular members are arranged on a basket in a comparative example. As shown in FIG. 7, in the prior art, a plurality of annular members 1 are packed on a basket 10 without any gaps. Considering productivity, it is normal to pack adjacent annular members 1 so that they are in contact with each other without any gaps. That is, when a plurality of annular members 1 are packed without any gaps, the number of bearing rings that can be produced at one time can be increased, and the arrangement work is also very simple. In such a conventional technique, an elliptical deformation occurs in the annular member 1 after the heat treatment, but the machining allowance is increased to ensure the roundness of the annular member 1 in the subsequent grinding process. Therefore, in the past, there was no tendency to be so concerned about the elliptical deformation of the annular member 1. However, in reality, it takes a lot of time and cost to ensure the roundness of the annular member 1 in the grinding process.

The inventor of the present application focused on the fact that when the annular member 1 is heat-treated using a batch-type heating furnace, elliptical deformation occurs in the annular member 1 and the roundness deteriorates in the method of the prior art, and this elliptical deformation It was also found that the deterioration in roundness was caused by heat treatment (especially cooling during hardening) of adjacent annular members 1 while in contact with each other. Therefore, as mentioned above, we came up with the idea of arranging the plurality of annular members 1 so that they do not come into contact with each other.

(Laminated body arrangement process)
Next, a laminate arrangement step of arranging the laminate 100 in which the plurality of annular members 1 are arranged inside the heating furnace 20 will be described. FIG. 8 is a schematic cross-sectional view of the heating furnace.

As shown in FIG. 8, the heating furnace 20 is a batch type heating furnace, and includes a loading section 30 into which the laminate 100 is transported, a heating section 40 for heating the plurality of annular members 1, and a plurality of annular members 1. A cooling section 50 for cooling the member 1 and a transport section 60 for transporting the basket 10 between the loading section 30 and the heating section 40 and between the loading section 30 and the cooling section 50 are provided. Note that in FIG. 8, illustration of the circulation device 55 provided in the cooling unit 50 is omitted. The circulation device 55 will be described later using FIG. 9.

Each of the carrying-in section 30, the heating section 40, the cooling section 50, and the conveying section 60 supports a plurality of rollers 31, 41, 51, 61 for moving the laminate 100, and rollers 31, 41, 51, 61. It has bases 33, 43, 53, 63.

A first door 71 that can be opened and closed is provided between the carry-in section 30 and the transport section 60, and a second door 73 that can be opened and closed is provided between the transport section 60 and the heating section 40.

The heating section 40 includes a burner 45 for heating the inside of the heating section 40, and a fan 47 for stirring the atmosphere inside the heating section 40.

The base 53 of the cooling unit 50 and the base 63 of the transport unit 60 are connected to each other, and are movable together in the vertical direction by a cylinder 65 provided above.

The cooling unit 50 is a liquid tank in which a cooling liquid is stored, and in this example, it is an oil tank in which cooling oil O is stored. Note that the cooling fluid is not limited to cooling oil, and may be water, an aqueous solution, or the like. The height of the liquid level of the cooling oil O is set so that the entire stacked body 100 disposed in the cooling unit 50 is immersed in the cooling oil O.

As shown in FIG. 9, the cooling unit 50 includes a circulation device 55 that circulates cooling oil within the oil tank. FIG. 9 is a diagram of the cooling unit 50 seen from the left and right directions in FIG. The circulation device 55 is disposed on both sides of the base 53 and includes a pair of screws 56 that generate a vertical flow of cooling oil O, and a circulation device 55 that surrounds the pair of screws 56 from the outside and that generates a flow of cooling oil O by the pair of screws 56. A pair of guide members 57 for guiding the flow of the water.

Therefore, when a downward flow of cooling oil O is generated in the vicinity of the pair of screws 56, the cooling oil O passes upward through the stacked body 100 placed on the base 53 (see FIG. 9). (see dashed arrow). On the other hand, when the upward flow of cooling oil O is generated near the pair of screws 56, the cooling oil O passes downward through the stacked body 100 placed on the base 53.

When placing the laminate 100 inside such a heating furnace 20, first, a plurality of baskets 10 each containing a plurality of annular members 1 are placed on the base 33 (roller 31) of the loading section 30. Stacked on tray 80. In the illustrated example, nine baskets 10 are stacked on the tray 80. Note that a plurality of annular members 1 may be accommodated in the tray 80 as well.

Next, the first door 71 is opened, the stacked body 100 is moved onto the base 63 of the transport section 60, and the first door 71 is closed. Then, the second door 73 is opened, the laminate 100 is moved onto the base 43 of the heating section 40, and the second door 73 is closed. In this way, the laminate 100 containing the plurality of annular members 1 is arranged within the heating section 40.

(Heat treatment process)
In the heat treatment step of heat-treating the plurality of annular members 1 housed in the laminate 100, quenching (heating and cooling) is performed, followed by tempering (heating and cooling).

Note that it is preferable to form a surface hardening layer on the annular member 1 by carburizing, nitriding, or carbonitriding. This is because when the elliptical deformation is suppressed as in the annular member 1 of this embodiment, the hardened surface layer can be ground uniformly in the circumferential direction, so a hardened layer with less unevenness can be formed on the surface of the annular member 1. . Note that the carburizing treatment, nitriding treatment, or carbonitriding treatment is performed by maintaining the material at 900 to 1000° C. in a carbon or nitrogen gas atmosphere for several hours to several tens of hours. Thereby, a desired surface hardening layer can be obtained.

The plurality of annular members 1 arranged in the heating section 40 are hardened (heated). Note that it is preferable that the plurality of annular members 1 be subjected to deep hardening. Note that the conditions for deep quenching are oil cooling at a quenching temperature of 800 to 850°C.

Next, by driving the cylinder 65, the base 53 of the cooling section 50 and the integrated base 63 are raised and positioned at the same height as the base 33 of the carrying-in section 30 and the base 43 of the heating section 40. let After the quenching (heating) of the plurality of annular members 1 is completed, the second door 73 is opened and the stacked body 100 is moved to the base 53 of the cooling unit 50. Then, the base 53 of the cooling unit 50 is lowered so that the stacked body 100 is immersed in the cooling oil O.

As described above, the pair of screws 56 allow the basket mounting portion 11 and the tray mounting portion 81 of the stacked body 100 to be screwed upwardly or downwardly through the plurality of through holes 15 and 85 forming a honeycomb shape. Cooling oil O passes through. Note that the quenching (cooling) is performed by stirring cooling oil O at 60 to 100°C.

Here, since the heating furnace 20 is a batch-type heating furnace and has the above-described configuration, the quenching (heating) and quenching (cooling) are performed while the arrangement of the plurality of annular members 1 is maintained in the stacked body 100. That is, as shown in FIG. The member 1 moves between the loading section 30, the heating section 40, the cooling section 50, and the conveying section 60 without moving.

Therefore, even when the plurality of annular members 1 are hardened (cooled) in the cooling section 50, the plurality of annular members 1 are arranged on the laminate 100 so as not to come into contact with each other. As a result, the cooling oil O flows vertically between adjacent annular members 1, so that the annular members 1 are uniformly cooled. On the other hand, when the cooling oil O flows in the left-right direction (both sides, one side), there is a difference in cooling due to the difference in the flow rate of the cooling oil depending on where the annular member 1 is placed, and all the annular members in the same basket are uniformly distributed. The deformation of the annular member 1 increases because the annular member 1 is not cooled properly. When the cooling oil O flows in the vertical direction as in this embodiment, problems such as only a part of the annular member 1 being cooled and other parts not being cooled do not occur, and the entire annular member 1 is cooled uniformly. be done.

The inventors of the present application have found that whether or not the annular member 1 can be uniformly cooled during this quenching (cooling) is related to the elliptical deformation (deterioration of roundness) of the annular member after heat treatment. In other words, during quenching (cooling), the non-uniformity of cooling, in which the parts where the annular members 1 are in contact with each other is not sufficiently cooled, while the parts where the annular members 1 are not in contact with each other is cooled is caused by the It was discovered that this is the cause of the elliptical deformation of the annular member 1. Then, in order to uniformly cool the annular member 1, we came up with a configuration in which a plurality of annular members 1 are arranged on the stacked body 100 so as not to come into contact with each other.

Note that the arrangement of the plurality of annular members 1 as described above is a case where quenching (heating) and quenching (cooling) are performed while the arrangement of the plurality of annular members 1 on the laminate 100 is maintained, that is, a batch method. This is particularly suitable when the heating furnace 20 is used. In the batch heating furnace 20, the arrangement of the plurality of annular members 1 on the stacked body 100 is maintained from the annular member arrangement step before the annular members 1 are carried into the heating furnace 20 to the basket arrangement step and the heat treatment step. Therefore, the arrangement of the plurality of annular members 1 during the annular member arrangement step is very important.

On the other hand, in a continuous heating furnace, the arrangement of the plurality of annular members 1 may be different between hardening (heating) and hardening (cooling). That is, during quenching (during cooling), the plurality of annular members 1 are individually placed into an oil tank in which cooling oil is stored. In this case, the arrangement of the plurality of annular members 1 is not maintained. In such a case, even if the plurality of annular members 1 are lined up and quenched (heated) so that they do not come into contact with each other, the annular members 1 may come into contact with each other during quenching (during cooling), causing elliptical deformation in the annular member 1. be.

Furthermore, as described above, the through holes 15 forming the honeycomb shape of the basket placement section 11 have a hexagonal shape when viewed from the front and back directions, and the through holes 85 forming the honeycomb shape of the tray placement section 81 are viewed from the front and back directions. Since the hexagonal shapes have the same dimensions, the annular member 1 can be uniformly heated and cooled during hardening, and deformation of the annular member 1 can be suppressed.

In addition, the honeycomb shape of the basket mounting portion 11 and the honeycomb shape of the tray mounting portion 81 are aligned in phase so that the plurality of through holes 15 and 85 overlap each other when viewed from the front and back directions. At times, the annular member 1 can be heated and cooled uniformly, and deformation of the annular member 1 can be suppressed.

Furthermore, since the thickness D ₂ of the tray placement portion 81 is larger than the thickness D 1 of the basket placement portion 11, the thickness D ₂ of the tray placement portion 81 having a honeycomb shape becomes thicker, and _air is removed during quenching. The effect of rectifying the heating medium and cooling medium such as water, oil, etc. is enhanced, the annular member 1 can be uniformly heated and cooled, and deformation of the annular member 1 can be suppressed.

Further, the thickness D ₁ of the basket mounting portion 11 is set to be equal to or larger than the hexagonal opposite side dimension L 1 when the through hole 15 is viewed from the front and back directions (D 1 ≧L 1 ), so that the thickness D ₁ of the basket mounting portion 11 is set to be equal to or larger than the hexagonal opposite side dimension L 1 when the through hole 15 is viewed from the front and back directions (D ₁ ≧L ₁ ). ) becomes thicker, the heating medium and cooling medium such as air, water, and oil can be rectified during quenching, the annular member 1 can be uniformly heated and cooled, and deformation of the annular member 1 can be suppressed. can.

Further, the thickness D ₂ of the tray mounting portion 81 is set to be more than twice the opposite side dimension L ₂ of the hexagonal shape when the through hole 85 is viewed from the front and back directions (D ₂ ≧2L ₂ ), so the honeycomb shape ( The thickness of the through hole 85) is increased, and during quenching, the heating medium and cooling medium such as air, water, and oil can be rectified, and the annular member 1 can be uniformly heated and cooled, thereby suppressing deformation of the annular member 1. can do.

After the quenching (cooling) is performed as described above, the laminate 100 is again moved to the base 33 of the carry-in section 30 and further moved to a tempering furnace (not shown), where the plurality of annular members 1 are tempered ( heating and cooling). Note that tempering is performed at 150 to 300°C for 1 to 2 hours.

(Grinding process)
After the heat treatment process, a grinding process for grinding the annular member 1 is performed. In the grinding process, the inner and outer diameter surfaces of the annular member 1 are ground to produce a bearing ring. According to the manufacturing method of the present application, the elliptical deformation of the annular member 1 due to heat treatment is suppressed, and the circularity of the annular member 1 is also good, so the amount of grinding required in the grinding process can be reduced, and the number of times of the grinding process can be reduced. This has a significant cost reduction effect.

Then, the bearing ring completed by the above method can be assembled together with the rolling elements and the cage to form a bearing.

As explained above, the following contents are disclosed in this specification.
(1) Multiple baskets stacked front to back,
a tray on which the plurality of baskets are placed;
A laminate comprising:
The basket has a basket placement part on which a plurality of annular members serving as bearing races can be placed,
The tray has a tray placement part on which the annular member can be placed,
The basket placement part and the tray placement part have a honeycomb shape in which a plurality of hexagonal prism-shaped through holes pass through the basket and the tray in the front and back directions,
The hexagonal shape of the through-holes that form the honeycomb shape of the basket placement section viewed from the front and back directions is the same as the hexagonal shape of the through-holes that make up the honeycomb shape of the tray placement section when viewed from the front and back directions. A laminate characterized in that it has dimensions.
(2) The honeycomb shape of the basket placement portion and the honeycomb shape of the tray placement portion are aligned in phase so that the plurality of through holes overlap each other when viewed from the front and back directions;
The laminate according to (1).
(3) The thickness of the tray placement section in the front and back directions is greater than the thickness of the basket placement section in the front and back directions;
The laminate according to (1) or (2).
(4) The thickness of the basket mounting portion in the front and back directions is equal to or larger than the opposite side dimension of the hexagonal shape when the through hole is viewed from the front and back directions;
The laminate according to any one of (1) to (3).
(5) The thickness of the tray mounting portion in the front and back directions is at least twice the opposite side dimension of the hexagonal shape when the through hole is viewed from the front and back directions;
The laminate according to any one of (1) to (4).
(6) A method for manufacturing a bearing raceway, comprising:
In the laminate according to any one of (1) to (5), an annular member placing step of placing the annular member on at least the basket placing part;
a laminate arrangement step of arranging the laminate inside a heating furnace;
a heat treatment step of heat treating the annular member;
A method of manufacturing a bearing race, including:
(7) In the annular member placement step, the annular member is placed on the basket placement section and the tray placement section;
The method for manufacturing a bearing ring according to (6).

1 Annular member 10 Basket 11 Basket placing part 13 Basket outer circumferential part 13a Back surface 13b Front surface 14 Convex part 16 Flat plate part 20 Heating furnace 30 Carrying-in part 40 Heating part 50 Cooling part 60 Conveying part 80 Tray 81 Tray placing part 83 Tray outer circumferential part 83a Back surface 83b Front surface 85 Through hole 86 Flat plate portion 100 Laminated body D ₁ , D ₂ thickness L ₁ , L ₂ opposite side dimension

Claims (7)

Multiple baskets stacked front to back,
a tray on which the plurality of baskets are placed;
A laminate comprising:
The basket has a basket placement part on which a plurality of annular members serving as bearing races can be placed,
The tray has a tray placement part on which the annular member can be placed,
The basket placement part and the tray placement part have a honeycomb shape in which a plurality of hexagonal prism-shaped through holes pass through the basket and the tray in the front and back directions,
The hexagonal shape of the through-holes that form the honeycomb shape of the basket placement section viewed from the front and back directions is the same as the hexagonal shape of the through-holes that make up the honeycomb shape of the tray placement section when viewed from the front and back directions. A laminate characterized in that it has dimensions. The honeycomb shape of the basket placement portion and the honeycomb shape of the tray placement portion are aligned in phase so that the plurality of through holes overlap each other when viewed from the front and back directions,
The laminate according to claim 1. The thickness of the tray placement part in the front and back directions is greater than the thickness of the basket placement part in the front and back directions.
The laminate according to claim 1. The thickness of the basket mounting portion in the front and back directions is equal to or larger than the opposite side dimension of the hexagonal shape when the through hole is viewed from the front and back directions.
The laminate according to claim 1. The thickness of the tray mounting portion in the front and back directions is at least twice the opposite side dimension of the hexagonal shape when the through hole is viewed from the front and back directions.
The laminate according to claim 1. A method for manufacturing a bearing ring, the method comprising:
In the laminate according to any one of claims 1 to 5, an annular member placing step of placing the annular member on at least the basket placement part;
a laminate arrangement step of arranging the laminate inside a heating furnace;
a heat treatment step of heat treating the annular member;
A method of manufacturing a bearing race, including: In the annular member placement step, the annular member is placed on the basket placement section and the tray placement section;
A method for manufacturing a bearing race according to claim 6.

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