JP2001001708A - Shaft end caulking tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool for caulking a shaft end which facilitates caulking work such that deflection and deformation rarely occurs even if elevated pressure force is applied, excessive pressure force is unnecessary for obtaining required axial tension, and setting of pressure force for obtaining the required shaft force is easy. SOLUTION: This shaft end caulking tool 10 has a shaft portion 12 and a bearing 2 disposed at the outer periphery of the shaft portion 12. The caulking tool 10 is used to caulk a shaft end of the shaft portion 12 onto an end face of a collar 21a of an inner ring 21 of the bearing 2 so as to prevent the bearing 2 from slipping and supply preload. At least a surface of a concave portion 10a contacting with the shaft end is made of a super-hard tool material having higher hardness (830 Hv or more) than that of high-speed tool steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device having at least a shaft body and an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion of the shaft body, for example, a vehicle attached to a vehicle such as an automobile. The present invention relates to a shaft end caulking tool in a bearing device such as a hub unit for a vehicle.

[0002]

2. Description of the Related Art As a conventional bearing device of this type, an example of the structure of a vehicle hub unit is shown in FIGS. The illustrated vehicle hub unit includes a hub wheel 1 and a double-row outwardly directed angular ball bearing 2. Hub wheel 1
Has an annular plate portion 11 and a shaft portion 12. Annular plate part 1
1, wheels (not shown) are attached. The shaft end of the shaft portion 12 has a structure of the caulking portion 3 formed by punching and caulking with a shaft end caulking tool (hereinafter, simply referred to as a tool) 10. 3a is the shaft end before swaging.

An angular ball bearing 2 is fixed to the outer periphery of the shaft portion 12 as a rolling bearing. Angular contact ball bearing 2
Has an inner ring 21, an outer ring 22, a plurality of balls 23, and two crown-shaped retainers 24.
By pressing the end face of 1a, a required preload (compressive stress) is given and is prevented from coming off.

[0004] In order to reduce the weight and reduce the number of parts, and to reduce the cost, such an angular ball bearing 2 is prevented from slipping off and applying a preload to the angular ball bearing 2 instead of tightening the shaft end of the shaft portion 12 with a conventional nut. It has become.

[0005]

By the way, in the bearing 2 described above, in order to compress the ball 23 between the inner ring 21 and the outer ring 22 and to apply a preload, a flange 21a of the inner ring 21 is required. Since the caulked portion 3 is applied to the end face, the inner ring 21 is provided.
A force which tries to escape from the shaft in the axial direction acts on the caulking portion 3.
As a result, a reaction force (axial force) inward in the axial direction is generated from the caulked portion 3. Therefore, in order to maintain the performance of the bearing 2, it is necessary for the caulking portion 3 to secure an axial force against the force of the inner ring 21 trying to come out.

By the way, when such a caulking portion 3 is formed, the tool end is deformed by pressing the tool 10 inward in the axial direction while the tool 10 is applied to the shaft end. The pressing force is set according to the required axial force.

In the conventional tool 10, the required axial force and
When comparing the pressing force required to obtain this axial force, even if the pressing force is increased, the axial force does not tend to increase in proportion to this, and therefore, when obtaining a large axial force, In addition, it is necessary to apply a considerably large pressing force to the tool 10, which makes it difficult to caulk the shaft end, or requires an expensive press machine to apply such a large pressing force. I was

Therefore, the present inventors have intensively studied the cause. As a result, when attention was paid to the material used for the conventional tool 10, the material was a high-speed tool steel generally used. This high-speed tool steel had a very high surface hardness of 780 Hv (Vickers hardness), so it was expected that the high-speed tool steel would not easily bend and deform even if the pressing force was increased. As a result, unexpectedly, it was easily deformed under the reaction force from the shaft end, and it was found that the pressure was attenuated. .

When the cause is investigated, the present inventors have found that when the shaft end is caulked using such a tool 10, a large amount of wear powder is generated due to the contact between the shaft end and the tool 92. They also found that the abrasion powder penetrated into the bearing and reduced the life of the bearing.

Therefore, the present invention provides a tool which does not easily bend and deform even when a pressing force is applied to obtain a required axial force and a reaction force from a shaft end, and does not easily cause a decrease in the pressing force. Is a common issue to be solved.

Another object of the present invention is to provide a tool capable of reducing the amount of abrasion powder generated when a shaft end caulking operation is performed and consequently extending the life of the bearing. And

[0012]

A first aspect of the present invention is a shaft body,
For a bearing device having at least an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion of the shaft body, the shaft end of the shaft body is used to prevent the rolling bearing from slipping off and apply a preload. A shaft end caulking tool used for caulking an end surface of a flange portion of an inner ring of a rolling bearing, at least a portion that comes into contact with the shaft body is formed of a super-hard tool material harder than high-speed tool steel. It is characterized by having.

In the first shaft end swaging tool of the present invention, preferably, a material having a hardness of 830 Hv or more is selected as the super hard tool material.

[0014] The first shaft end caulking tool of the present invention is preferably selected from the group consisting of cemented carbide, cermet, coated cemented carbide, and ultrafine grained cemented carbide as the ultrahard tool material.

A second aspect of the present invention is to provide a bearing device having at least a shaft body and an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion of the shaft body. A shaft end caulking tool used for caulking the shaft end of the shaft body to the end surface of the flange portion of the inner ring of the rolling bearing, wherein the base has a hardness smaller than that of the super hard tool material. Molded from material and at least
On the surface of the base, a hard film made of a super-hard tool material is formed at a portion in contact with the shaft.

In the second tool for caulking the shaft end of the present invention, preferably, a material having a hardness of 1000 Hv or more is selected as the material of the hard film.

In the second tool for caulking the shaft end of the present invention, preferably, either titanium nitride or diamond-like carbon is selected as the material of the hard film.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments shown in the drawings. This embodiment will be described with reference to FIGS.

The bearing device according to the present embodiment has a hub wheel 1 as an example of a shaft body, and a double row outward bearing as an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion 12 of the hub wheel 1. The present invention is applied to a vehicle hub unit having at least an angular ball bearing (hereinafter simply referred to as a bearing) 2.
This structure is the same as that shown in FIGS. 1 and 2 except for the shaft end swaging tool 10.

This embodiment has a feature in the structure of a shaft end swaging tool (hereinafter, referred to as a tool) 10.

The following is a description. As described above, the tool 10 is used for caulking the shaft end of the shaft portion 12 to the end surface of the flange portion of the inner ring 21 of the bearing 2 in order to prevent the bearing 2 from slipping off and apply a preload.

The tool 10 has an annular concave portion 10a which fits the caulking shape of the caulking portion 3 on the periphery of the flat bottom surface.
The recess 10a is included in a portion that comes into contact with the shaft. The shape of the concave portion 10a is not limited to the embodiment, and may be variously changed according to the caulking state. This tool 10
Is lowered at a predetermined speed by applying a pressing force P1 by a press machine. As a result, the shaft end in the upright state of the shaft portion 12 is deformed radially outward along the inner surface of the concave portion 10a, so that the caulked portion 3 is formed, and the inner ring 2 is formed.
The end face of the first flange 21a is swaged.

Next, the features of this embodiment will be described.

The tool 10 includes at least the caulking recess 1
The surface hardness of Oa is 830 Hv (Vickers hardness) or more. In this case, the entire tool 10 may have a hardness of 830 Hv or more. 83 only on the surface of recess 10a
It may have a hardness of 0 Hv or more. The critical significance of setting the lower limit of the surface hardness of the tool 10 to 830 Hv is 830
If it is less than Hv, it is not preferable because rigidity and wear resistance are low, and if it is more than 830 Hv, it is preferable because rigidity and wear resistance are high. In addition, even at a hardness of 830 Hv or more, more preferably, the surface hardness is 90
It is 0 Hv or more, and most preferably 1000 Hv or more.

An ultra-hard tool material is selected as a constituent material of the example tool 10 for obtaining a hardness of 830 Hv or more. Examples of the super-hard tool material include a super-hard alloy, a cermet, a coated super-hard alloy, and an ultra-fine super-hard alloy.

In these super-hard tool materials, the super-hard alloy comprises a metal and a hard metal compound, and the main component in the hard composition is tungsten carbide. Cermet is
It is composed of a metal and a hard metal compound, and the main components in the hard composition are titanium, tantalum (niobium) carbide, carbonitride and nitride, and the component of tungsten carbide is small. The coated cemented carbide is one in which a carbide or a nitride (such as titanium carbide, titanium nitride, or titanium carbonitride) is chemically or physically adhered in a single layer or a multilayer to the surface of the cemented carbide. The ultrafine cemented carbide is composed of a metal and a hard metal compound, the main component of the hard composition is tungsten carbide, and the hard coarse particles have an average particle size of 1%.
μm or less. A super-hard tool material suitable for obtaining a hardness of 830 Hv or more may be appropriately selected from these super-hard tool materials.

A comparison of the structural difference between the tool 10 of the embodiment having the above-described structure and the conventional tool 10 shows that the conventional tool 10 is made of high-speed tool steel. The surface hardness of the concave portion 10a is 780 Hv conventionally, whereas the tool 10 of the embodiment has a surface hardness of 780 Hv.
Is made of a super-hard tool material, and its recess 1
The surface hardness of Oa is 830 Hv or more. Therefore,
The difference in the surface hardness between the two concave portions 10a is that the embodiment has a hardness of 50 Hv or more, and the tool 10
Can be suppressed from bending deformation.

The axial force obtained when the caulking portion 3 was formed by applying the same pressing force P1 to the conventional tool 10 and the tool 10 according to the embodiment was measured. While the axial force is 3900kgf,
According to the tool 10 of the embodiment, the axial force is 5500 kgf.
Becomes The difference between the two axial forces is that the tool 10 of the embodiment has a larger axial force of 1600 kgf. Therefore, in the embodiment, despite the same pressing force P1, a larger axial force is obtained as compared with the conventional art, and as a result, the bending deformation is suppressed, and in this case, the same axial force is obtained. In the case of the tool 10 of the embodiment, the pressing force P1 can be reduced, so that the caulking operation is easy, and the press machine does not need to be expensive and large, which is preferable.

The diameter of the caulked portion 3 by the conventional tool 10 and the tool 10 of the embodiment is the same as that of the conventional tool 10.
Is 37.5 mm in the case of
In the case of 0, it was 38.5 mm. With the tool 10 of the embodiment, the diameter of the swaged portion 3 is larger. That is, according to the tool 10 of the embodiment, the shaft end of the shaft portion is extended outward in the radial direction, and the swaged form is more improved. Is a favorable result.

Further, the amount of abrasion powder generated by the conventional tool 10 and the tool 10 of the embodiment is large in the conventional case, but is small in the embodiment. . This is effective in extending the life of the bearing by swaging with the tool 10 of the embodiment, and is a preferable result.

In the above-described embodiment, the entire tool 10 is made of a super-hard tool material.
A hard film (not shown) made of a super-hard tool material may be formed only on the surface of the concave portion 10a as a portion that comes into contact with the shaft. In order to form the hard film, the basic shape of the tool 10 is formed on the basis of a metal material having a hardness lower than that of the super hard tool material, for example, a high speed tool steel, and the super hard tool The material is CVD or PV
It may be formed by a method D or an ion plating method.

In this case, the base material is high-speed tool steel or a tool material having a hardness lower than that, and the ultra-hard tool material forming the hard film is 1000 Hv.
A material having the above hardness is preferable. Since the hardness of the base is as low as 780 Hv, the surface film is at least 1000
By setting it to Hv or more, bending deformation of the tool 10 due to caulking can be sufficiently suppressed. As the surface film material, a material having 1000 Hv or more among the above-mentioned super hard tool materials may be selected. For example, titanium nitride (TiN, TiC, CrN, etc.) or diamond-like carbon (Diamond Like Carb) may be used.
on: DLC) is selected, the surface hardness becomes 3000 Hv, which is particularly preferable when the hardness of the base material is small.

In the case of the tool 10 according to the embodiment in which the hard film is formed only on the surface as described above, the bending deformation of the tool 10 due to caulking can be suppressed more than the conventional one, and the axial force larger than the conventional one can be reduced. In addition, the amount of abrasion powder generated is small, so that it is effective for extending the life of the bearing, which is preferable.

In the above-described embodiment, the bearing is a double-row outward-facing angular contact ball bearing. However, the bearing is not limited to this, and may be an oblique contact type rolling bearing.

The above-described embodiment is not limited to a vehicle hub unit comprising a combination of a hub wheel and an angular ball bearing. The present invention can also be applied to a bearing device in which a rolling bearing of the type is arranged on the outer periphery of a shaft portion of the shaft body.

Although the tool 10 for caulking is punching caulking, rolling caulking as shown in FIG. 3 may be used. In other words, for example, the shaft end of the shaft portion 12 of the hub wheel is formed in a cylindrical shape, and the tool 30 is tilted at a required angle θ with respect to the cylindrical shaft end, and the tool 90 is rotated by rotating the rotating shaft 31. By rolling, the cylindrical shaft end of the shaft portion 12 may be plastically deformed radially outward, and the plastically deformed portion may be pressed against the outer end surface of the inner race 21 to form the caulked portion 3. Absent. That is, the tool 30 of FIG.
It may have the same configuration as 0 and have the same operation and effect.

[0037]

As described above, in the case of the first shaft end swaging tool according to the present invention, at least the portion that comes into contact with the shaft body is formed of a super-hard tool material harder than high-speed tool steel. In order to obtain the required axial force, even if the pressing force is increased like a conventional tool, it does not easily bend and deform, and it is not necessary to apply an excessive pressing force to obtain the required axial force. Thus, a tool for crimping the shaft end can be easily formed, for example, the setting of the pressing force for obtaining the axial force can be facilitated.

Further, in this case, when the shaft end caulking operation is performed, the amount of abrasion powder generated due to the contact between the shaft end and the tool can be reduced, which is preferable for improving the life of the bearing.

Particularly, 830H is used as the super hard tool material.
When a material having a hardness of at least v is selected, compared with a high-speed tool steel having a hardness of 780 Hv, at least 50 Hv,
Since it is hard, in the past, it deformed in the process of pressurizing with a predetermined pressing force and caulking, but it became a shaft end caulking tool that does not bend and becomes easy to caulking work, and the amount of wear powder generated It is greatly reduced, making it a very practical tool.

In the case of the second shaft end caulking tool of the present invention, the base is formed of a tool material having a hardness lower than that of the super-hard tool material, and at least at the surface of the base,
Since a hard film made of a super-hard tool material is formed in a portion in contact with the shaft body, in order to obtain a required axial force,
Even if the pressing force is increased like a conventional tool, it does not easily bend and deform, so there is no need to apply an excessive pressing force to obtain the required axial force, and the pressing force for obtaining the required axial force It is a tool for shaft end caulking that facilitates caulking work, such as easy setting of the tool, and it is easy to manufacture compared to the case where the whole is made of super-hard tool material, etc. The amount used can be reduced, which can contribute to cost reduction.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a vehicle hub unit according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a longitudinal side view of a vehicle hub unit according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hub wheel 12 Hub wheel shaft part 3a Shaft end 2 Double row outward angular ball bearing 21 Inner ring 21a Inner ring flange 3 Caulking part 10 Shaft end caulking tool

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Shinichiro Kashiwagi 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Inside Koyo Seiko Co., Ltd. (72) Inventor Tadashi Tadashi 3-5-8 Minamisenba, Chuo-ku, Osaka-shi Koyo Seiko Co., Ltd. F-term (reference) 3C030 BD05 CA02 3J101 AA02 AA32 AA43 AA54 AA62 BA53 DA09 FA44 GA01

Claims (6)

[Claims] The present invention relates to a bearing device having at least a shaft body and an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion of the shaft body. A tool for caulking the shaft end used to caulk the shaft end of the shaft body to the end surface of the flange of the inner ring of the rolling bearing, at least a portion that comes into contact with the shaft body is made of high-speed tool steel. A shaft end swaging tool made of a hard super hard tool material. 2. The tool for crimping a shaft end according to claim 1, wherein a material having a hardness of 830 Hv or more is selected as the super-hard tool material. 3. The tool for caulking a shaft end according to claim 2, wherein the ultra-hard tool material is selected from one of a cemented carbide, a cermet, a coated cemented carbide, and an ultra-fine cemented carbide. A tool for caulking a shaft end, characterized in that: 4. A bearing device having at least a shaft body and an oblique contact type rolling bearing disposed on the outer periphery of a shaft portion of the shaft body, for preventing the rolling bearing from coming off and applying a preload. A shaft end caulking tool used for caulking the shaft end of the shaft body to the end surface of the flange of the inner ring of the rolling bearing, wherein the base is formed of a tool material having a hardness smaller than that of the super hard tool material. And a hard film made of an ultra-hard tool material is formed on at least a portion of the base surface that comes into contact with the shaft body. 5. The tool according to claim 4, wherein a material having a hardness of 1000 Hv or more is selected as a material of the hard film. 6. The shaft end swaging tool according to claim 5, wherein one of titanium nitride and diamond-like carbon is selected as a material of the hard film.
A tool for caulking a shaft end, characterized in that: