JP2002333016A - Manufacturing method of rolling bearing unit for wheel support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine quality of a state of a suppressing part suppressing an inner end face of an inner ring 3 such as a fastened state of a nut 11 and enhance improvement of durability of a rolling bearing unit 1 for wheel support. SOLUTION: An internal gap of the rolling bearing unit 1 for wheel support is measured or calculated after the inner ring 3 is fit onto a step part 8 and before tightly fastening the nut 11. Then, after tightly fastening the nut 11, the internal gap of the rolling bearing unit 1 for wheel support is measured again. A difference of the internal gap before and after tightly fastening the nut 11 is compared with a set value predetermined on the basis of a non- defective item, and an obtained quality of the rolling bearing unit 1 for wheel support is determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The rolling bearing unit for supporting wheels according to the present invention is used to rotatably support wheels of an automobile with respect to a suspension device.

[0002]

2. Description of the Related Art The wheels of an automobile are supported on a suspension system by rolling bearing units for supporting wheels. FIG. 3 shows a first example of a rolling bearing unit for supporting a wheel, which has been widely implemented conventionally. The rolling bearing unit 1 for supporting a wheel includes a hub 2, an inner ring 3, an outer ring 4, and a plurality of rolling elements 5,5. Of these, the outer end of the outer peripheral surface of the hub 2 (the term "outside in the axial direction" refers to the side that is shifted outward in the width direction when assembled to an automobile, and is the left side in FIGS. The side closer to the side is referred to as the inner side and is on the right side in FIGS. 3 and 4.) Is formed with a first flange 6 for supporting the wheels. A first inner raceway 7 is formed on the outer peripheral surface of the intermediate portion of the hub 2, and a step 8 having a smaller outer diameter is formed on the inner end of the hub 2.

The inner ring 3 having a second inner raceway 9 formed on the outer peripheral surface thereof is fitted on the step portion 8. A male thread 10 is formed at the inner end of the hub 2, and the tip (the right end in FIG. 3) of the male thread 10 protrudes inward from the inner end surface of the inner race 3. And this male screw part 1
By holding the inner ring 3 between a nut 11 screwed to zero and a step surface 12 of the step 8, the inner ring 3 is fixedly connected to a predetermined position of the hub 2. A locking recess 13 is formed on the outer peripheral surface of the distal end of the male screw portion 10. Then, after tightening the nut 11 with a predetermined torque, a part of the nut 11 that is aligned with the locking recess 13 is crimped inward in the diameter direction to prevent the nut 11 from being loosened. I have.

A first outer raceway 14 facing the first inner raceway 7 and a second outer raceway 15 facing the second inner raceway 9 are provided on the inner peripheral surface of the outer race 4. Is formed. And these first and second inner raceways 7, 9
A plurality of the rolling elements 5 are provided between the first and second outer raceways 14 and 15, respectively. In the illustrated example, balls are used as the rolling elements 5 and 5. However, in the case of a heavy-duty rolling bearing unit for an automobile, tapered rollers may be used as these rolling elements.

In order to assemble the above-described rolling bearing unit 1 for supporting a wheel into an automobile, the outer ring 4 is fixed to a suspension device by a second flange 16 formed on the outer peripheral surface of the outer ring 4. The wheel is fixed to the flange 6 of.
As a result, the wheels can be rotatably supported by the suspension device.

Japanese Unexamined Patent Application Publication No. 11-129703 discloses a rolling bearing unit 1a for supporting a wheel as shown in FIG. The wheel supporting rolling bearing unit 1a of the second example of the conventional structure includes a hub 2a, an inner ring 3, and an outer ring 4
And a plurality of rolling elements 5 and 5. A first flange 6 for supporting the wheel is formed at a portion of the outer peripheral surface of the hub 2a near the outer end. A first inner raceway 7 is formed on the outer peripheral surface of the intermediate portion of the hub 2a, and a step 8 having a smaller outer diameter is formed on the inner end.

A cylindrical portion 1 for forming a caulking portion 17 for fixing the inner ring 3 is provided at the inner end of the hub 2a.
8 are formed. The inner ring 3 is attached to the inner end of the hub 2a.
Is fixed by plastically deforming the distal end portion of the cylindrical portion 18 radially outward as described above, and expanding the caulked portion 17.
To form The inner ring 3 is held between the caulked portion 17 and the step surface 12 of the step 8 formed at the inner end of the hub 2a.
To fix the inner ring 3 to the hub 2a.

In order for the above-described wheel supporting rolling bearing units 1 and 1a to exhibit the performance as designed, FIG.
The structure shown in FIG. 4 or the structure shown in FIG. 4 has a proper value for pressing the inner ring 3 axially outwardly fixed to the inner ends of the hubs 2 and 2a. Something is necessary. When the nut 11 in the structure shown in FIG. 3 and the caulking portion 17 in the structure shown in FIG. 4 respectively deviate from the appropriate values in the axial pressing force of the inner ring 3, the screwed portion or the caulking portion of the nut 11 17 is not only insufficient in strength, but also the rolling bearing units 1 and 1a for supporting the wheel.
The preload applied to each of the rolling elements 5, 5 constituting the above-mentioned formula deviates from an appropriate value. Further, so-called creep, in which the inner ring 3 rotates with respect to the hubs 2 and 2a, may occur.

Insufficient strength of the threaded portion or the portion where the caulking portion 17 is formed leads to a decrease in durability of the wheel supporting rolling bearing units 1 and 1a. If the preload is insufficient, the rolling bearing units 1 and 1a
Is reduced, and the running performance of the vehicle to which the wheel supporting rolling bearing units 1 and 1a are assembled is deteriorated. On the other hand, when the preload becomes excessive, the rotational resistance of the wheel supporting rolling bearing units 1 and 1a increases, and the fuel consumption performance of the vehicle to which the wheel supporting rolling bearing units 1 and 1a are assembled is included. Not only the running performance is deteriorated, but also the durability of the wheel supporting rolling bearing units 1 and 1a is impaired due to the excessive contact pressure of the rolling contact portion.

Conventionally, in the case of the structure shown in FIG. 3, the tightening torque of the nut 11 is restricted, and in the case of the structure shown in FIG. By regulating the caulking load applied to the cylindrical portion 18 provided at the inner end of the inner ring 2a, the force for pressing the inner ring 3 is regulated to an appropriate value. However, simply regulating the tightening torque and the caulking load may not necessarily result in the force for pressing the inner ring 3 becoming an appropriate value. For example, when regulating the tightening torque of the nut 11, the surfaces that rub against each other when the nut 11 is tightened (the end surface of the nut 11, both surfaces of the washer, the inner end surface of the inner race 3,
Differences in the frictional state based on differences in the shape, roughness, and the like of the inner peripheral surface of the female screw and the outer peripheral surface of the male screw portion 10 cause a difference in the relationship between the torque and the pressing force, and regulate this force to an appropriate value. There is a possibility that it will not be possible. Even when the caulking load for processing the caulking portion 17 is regulated, the cylindrical portion 18
Due to the difference in the shape of the member, the difference in the frictional state of each part, and the like, there is a difference in the relationship between the caulking load and the pressing force.

In the conventional case, after the nut 11 is tightened or the caulking portion 17 is formed, the preload applied to the rolling elements 5, 5 of the wheel supporting rolling bearing units 1, 1a is applied. By performing the measurement, the quality of the wheel supporting rolling bearing units 1 and 1a is determined.
In such a case, a method for measuring the preload is disclosed in
000-74788, a method of obtaining from a natural frequency of a rolling bearing unit,
0-96672, a method of obtaining from the bearing rigidity of a rolling bearing unit,
As described in Japanese Patent Publication No. 717, a method of individually measuring the preload of each row and calculating the preload from the sum is the same.
As described in Japanese Patent Application Laid-Open Publication No. H11-107, there is known a method of measuring a rotational torque in a state where an axial load is applied, and obtaining a preload from the measured value.

A method for measuring the internal clearance between the wheel supporting rolling bearing units 1 and 1a before the nut 11 is tightened or before the caulking portion 17 is formed is disclosed in Japanese Patent Application Laid-Open No. 7-127634. As described, from the internal clearance measured in a state where the inner ring 3 is partially fitted to the hubs 2 and 2a, and the press-fit length of the inner ring 3 thereafter,
There is a method of obtaining a preload (negative internal clearance). Further, it has been conventionally performed to measure the dimensions of the components of the wheel supporting rolling bearing units 1 and 1a separately, and to combine appropriate components to obtain a desired preload. In this way, before the nut 11 is tightened or before the caulking portion 17 is formed, the internal clearance of the wheel supporting rolling bearing units 1 and 1a is measured, and then the nut 11 is tightened or caulked. Even if the forming operation is performed, if the tightening or forming operation is performed as desired, the internal clearance (preload) of the completed wheel supporting rolling bearing unit 1, 1a can be set to a desired value.

[0013]

In the prior art, after the nut 11 has been tightened or the caulking portion 17 has been formed, it is applied to the rolling elements 5, 5 of the wheel supporting rolling bearing units 1, 1a. Either measuring the preload, or measuring the internal clearance of the wheel supporting rolling bearing units 1 and 1a before tightening the nut 11 or forming the caulking portion 17, I didn't do both. Therefore, the state before and after the tightening of the nut 11 or the state before and after the formation of the caulking portion 17 is compared to judge whether or not the tightening of the nut 11 or the formation of the caulking portion 17 is good. Did not.

On the other hand, in order to further improve the performance including the durability of the wheel supporting rolling bearing units 1 and 1a, the tightening of the nut 11 or the quality of the formation of the caulking portion 17 must be checked. It is considered preferable to determine. The manufacturing method of the rolling bearing unit for supporting a wheel of the present invention has been made in view of such circumstances.

[0015]

The rolling bearing unit for supporting a wheel, which is manufactured by the manufacturing method of the present invention, has first and second inner peripheral surfaces.
An outer member having a second outer raceway, a first on the outer peripheral surface, an inner member having a second inner raceway, and between the first, second outer raceway and the first, second inner raceway. , And a plurality of rolling elements provided so as to be freely rollable. Then, the inner member externally fits the inner ring provided with the second inner ring track on a part of the hub provided with the first inner ring track, and the inner ring is provided with a holding portion provided on a part of the hub. It is formed by pressing in the axial direction toward the first inner raceway.

According to the method of manufacturing a rolling bearing unit for supporting a wheel of the present invention, when manufacturing the rolling bearing unit for supporting a wheel as described above, the wheel support in a state before the inner ring is pressed by the restraining portion is provided. Measure or calculate the internal clearance of the rolling bearing unit. Then, after the inner ring is pressed by the holding portion, the internal clearance of the wheel supporting rolling bearing unit is measured. And, the difference between the internal gap before and after the pressing by the above-mentioned suppressing portion, which was obtained in advance,
By comparing the inner clearance before and after the inner ring is pressed by an appropriate holding portion with the difference between the internal clearances, the quality of the holding portion is determined.

[0017]

According to the method of manufacturing a rolling bearing unit for supporting a wheel of the present invention having the above-described configuration, it is determined whether or not a holding portion for pressing an inner ring in an axial direction, such as a tightening portion or a caulking portion of a nut against a male screw portion, is good. it can. Therefore, various performances including the durability of the wheel supporting rolling bearing unit can be further improved as compared with the case where the preload applied to the wheel supporting rolling bearing unit is simply measured.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 are block diagrams showing an apparatus used in carrying out the present invention, and the distribution of internal gaps before and after pressing when an inner ring is pressed by an appropriate holding portion. FIG. The structure itself of the wheel supporting rolling bearing unit manufactured by the manufacturing method of the present invention includes the wheel supporting rolling bearing units 1 and 1a of the first and second examples of the conventional structure shown in FIGS. This is the same as various conventionally known wheel supporting rolling bearing units. or,
Although not shown, the present invention can be applied not only to the wheel supporting rolling bearing units 1 and 1a for driven wheels as shown in FIGS. 3 and 4 but also to the wheel supporting rolling bearing units for driving wheels. .

In the method of manufacturing a wheel supporting rolling bearing unit according to the present invention, for example, when manufacturing the wheel supporting rolling bearing units 1 and 1a as shown in FIGS. After assembling, the internal clearance of the wheel supporting rolling bearing units 1 and 1a is measured or calculated by the first internal clearance measuring device 20.

According to the first internal clearance measuring device 20,
The method of measuring the internal clearance of the wheel supporting rolling bearing units 1 and 1a is not particularly limited. For example, the inner ring 3 is externally fitted to a step 8 formed at the inner end of the hub 2 or 2a by interference fitting. The outer end surface of the inner ring 3 is connected to the step surface 1 of the hubs 2 and 2a.
It is conceivable to measure the internal clearance of the wheel supporting rolling bearing units 1 and 1a in a state where the rolling bearing unit 2 is abutted. In this case, the measurement of the internal gap is performed as described in Japanese Patent Application Laid-Open No. 2000-74788.
A method of obtaining from the natural frequency of the rolling bearing unit, a method of obtaining from the bearing rigidity of the rolling bearing unit as described in JP-A-10-96672, and 10-1.
As described in Japanese Patent No. 85717, a method of individually measuring the preload of each row and calculating the preload from the total, see, 8-748.
As described in Japanese Patent Application Publication No. 44-44, a method of measuring a rotational torque in a state where an axial load is applied and obtaining a preload from the measured value can be adopted. Further, the dimensions of the components of the wheel supporting rolling bearing units 1 and 1a are separately measured, and the assembled components are brought into contact with the outer end surface of the inner ring 3 against the step surface 12 of the hubs 2 and 2a. It is also possible to adopt a method of calculating the preload obtained when the above is combined.

Regardless of which method is used to measure the internal clearance of the wheel supporting rolling bearing units 1 and 1a before the screwing / tightening of the nut 11 or the formation of the caulking portion 17, the measurement results are obtained. Is sent to the storage unit of the determiner incorporated in the second internal gap measuring device 21. On the other hand, the wheel supporting rolling bearing units 1 and 1a screw and tighten the nut 11 or form a caulking portion 17,
The inner ring 3 is fed into a fastening device 22 which presses the inner ring 3 outward in the axial direction. The fastening device 22 allows the hub 2
Nut 11 screwed into a male thread 10 formed at the inner end of the nut
The inner end surface of the inner ring 3 is suppressed by tightening the inner ring 3 or by forming the caulking portion 17 by plastically deforming the cylindrical portion 18 formed at the inner end portion of the hub 2a radially outward. In this state, the outer end surface of the inner ring 3 is
2, the rolling bearing units 1 and 1a for wheel support are obtained.

Thereafter, the wheel supporting rolling bearing units 1 and 1a are transferred to the second internal clearance measuring device 21 to measure the internal clearances of the wheel supporting rolling bearing units 1 and 1a. Such a second internal clearance measuring device 21
As a measuring method used when measuring the internal gap by the method described above, a method of obtaining from the natural frequency of the rolling bearing unit as described in Japanese Patent Application Laid-Open No. 2000-74788, and Japanese Patent Application Laid-Open No. 10-96672. As described in JP-A-10-185717, a method of obtaining from the bearing stiffness of a rolling bearing unit, as described in JP-A-10-185717, a method of individually measuring the preload of each row and obtaining the sum from the sum thereof, As described in JP-A-8-74844, a method of measuring a rotational torque in a state where an axial load is applied and obtaining a preload from the measured value can be adopted.

Regardless of the method used to measure the internal clearance of the wheel supporting rolling bearing units 1 and 1a, the difference between the internal clearance before and after the nut 11 is tightened or before and after the formation of the caulking portion 17 is determined. A properly tightened nut 11 or a suitably formed caulking portion 17 previously determined
Then, the difference between the internal clearance before and after the inner ring 3 is pressed when the inner ring 3 is pressed, that is, the set value is compared. When the difference between the internal gaps before and after the nut 11 is tightened or before and after the formation of the caulking portion 17 is within the range of the set value, the obtained wheel supporting rolling bearing unit 1 is obtained. 1a is determined to be a non-defective product. Conversely, if the value deviates from the set value, it is determined to be a defective product.

In order to obtain the set value, for example, 5
About 0 samples, all of which are non-defective samples, the difference in the internal gap before and after the tightening of the nut 11 or before and after the formation of the caulking portion 17 is measured. If the result of this measurement is subjected to normal distribution processing, a diagram showing the distribution of the internal gap before and after pressing when the inner ring is pressed by an appropriate holding portion as shown in FIG. 2 can be obtained. Therefore, if the individual measured values relating to the difference in the internal clearance are within the set range 6σ shown in FIG. 2, tightening or crimping of the nut 11 with respect to the obtained wheel supporting rolling bearing units 1 and 1a. Part 17
Is properly formed, and the wheel supporting rolling bearing units 1 and 1a are determined to be non-defective.

According to the method of manufacturing the wheel supporting rolling bearing unit of the present invention configured as described above, the external thread portion 1 is formed.
0, the tightening portion of the nut 11 and the caulking portion 17
For example, it is possible to determine the quality of the suppressing portion that presses the inner ring 3 in the axial direction. For this reason, various performances including the durability of the wheel supporting rolling bearing units 1 and 1a can be further improved as compared with the case where the preload applied to the wheel supporting rolling bearing units 1 and 1a is simply measured. .

[0026]

Since the present invention is constructed and operates as described above, the reliability and durability of the wheel supporting rolling bearing unit can be further improved, and maintenance-free automobiles can be further promoted. Things become possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an apparatus used when carrying out a manufacturing method of the present invention.

FIG. 2 is a diagram showing distribution of internal gaps before and after pressing when an inner ring is pressed by an appropriate holding portion.

FIG. 3 is a half sectional view showing a first example of a conventional structure.

FIG. 4 is a half sectional view showing the second example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Wheel supporting rolling bearing unit 2, 2a Hub 3 Inner ring 4 Outer ring 5 Rolling element 6 First flange 7 First inner ring track 8 Step 9 Second inner ring track 10 Male thread 11 Nut 12 Step surface 13 Stop recess 14 First outer raceway 15 Second outer raceway 16 Second flange 17 Caulking portion 18 Cylindrical portion 20 First internal clearance measurement device 21 Second internal clearance measurement device 22 Fastening device

Claims (4)

[Claims] 1. An outer member having first and second inner races on an inner peripheral surface, an inner member having first and second inner races on an outer peripheral surface, and first and second outer races. A first and a second inner raceway, between which a plurality of rolling elements are provided so as to be able to freely roll, each of the inner member, a part of the hub provided with the first inner raceway, A wheel-supporting rolling bearing in which the inner ring provided with the second inner ring raceway is externally fitted, and the inner ring is axially pressed toward the first inner ring raceway by a holding portion provided on a part of the hub. When manufacturing a unit, after measuring or calculating the internal clearance of the wheel supporting rolling bearing unit in a state before pressing the inner ring by the pressing portion, after pressing the inner ring by the pressing portion, Measure the internal clearance of the rolling bearing unit for wheel support, By comparing the difference between the internal gap before and after pressing by the part and the difference between the internal gap before and after pressing when the inner ring is pressed by an appropriate holding part, which was obtained in advance, the quality of the holding part is determined. A method for manufacturing a wheel supporting rolling bearing unit for determining 2. A hub in which a first flange is formed on an outer peripheral surface of one end, and a first inner raceway is provided on an outer peripheral surface of an intermediate portion via an integral or separate inner race. An outer ring having an outer race formed with a second inner raceway on an outer peripheral surface, and a second outer raceway facing the first inner raceway and a second inner raceway facing the second inner raceway on the inner circumferential surface. An outer ring forming an outer raceway, and a plurality of rolling elements provided between the first and second inner raceways and the first and second outer raceways, respectively, and the other end of the hub By pressing the inner ring externally fitted to the hub in the axial direction toward the first inner ring raceway with a restraining portion provided at least at a portion protruding from the inner ring externally fitted to the hub at the portion, When manufacturing the rolling bearing unit for wheel support fixed to the hub, After measuring or calculating the internal clearance of the wheel supporting rolling bearing unit in a state before pressing the inner ring of, after pressing the inner ring by the suppressing portion, measuring the internal clearance of the wheel supporting rolling bearing unit. And, the difference between the internal gap before and after pressing by the holding part,
Manufacture of a rolling bearing unit for wheel support for judging pass / fail of the holding portion by comparing the difference between internal gaps before and after pressing when the inner ring is pressed with an appropriate holding portion determined in advance. Method. 3. The method of manufacturing a rolling bearing unit for supporting wheels according to claim 1, wherein the pressing portion is a nut screwed into a male screw portion formed at an end of the hub. 4. The rolling bearing for supporting wheels according to claim 1, wherein the pressing portion is a caulking portion formed by plastically deforming a cylindrical portion formed at an end of the hub radially outward. Unit manufacturing method.