JP7421451B2 - Preload inspection method for wheel bearing devices - Google Patents

Description

The present invention relates to a preload inspection method for a wheel bearing device.

2. Description of the Related Art Wheel bearing devices that rotatably support wheels in suspension systems for automobiles and the like are conventionally known. In such a wheel bearing device, a preload is applied between the rolling elements and the raceway that constitute the bearing device.

By applying preload to the bearing device, the rigidity of the bearing device can be increased and vibration and noise can be suppressed. However, it is important to check whether an appropriate preload is applied to the bearing device, since applying too much preload can cause an increase in rotational torque and a decrease in service life.

As a method for checking the preload applied to a bearing device, for example, as disclosed in Patent Document 1, in a rolling bearing in which rolling elements are provided in double rows, by measuring the preload gap in the axial direction, A preload measurement method for measuring the preload applied to the bearing is known.

When determining the preload applied to a bearing from the preload gap, for example, in a wheel bearing device with specifications in which the inner member is configured by crimping the hub ring onto the inner ring, the amount of push-in of the inner ring when the hub ring is swaged is calculated. The preload applied to the bearing device can be determined by converting it into a preload gap reduction amount and combining the preload gap reduction amount and the preload gap before caulking.

In addition, for bearing devices configured to swage the hub ring onto the inner ring, the rotational torque of the bearing device before and after swaging is measured, and the amount of preload increase is calculated from the amount of increase in rotational torque before and after swaging. It is conceivable to measure the preload applied to the bearing device by calculating the preload and adding the preload increase amount to the preload of the bearing device before caulking.

Japanese Patent Application Publication No. 10-185717

As mentioned above, when determining the amount of preload gap reduction in a bearing device configured to swage the hub ring onto the inner ring, if an abnormality such as deformation of the inner ring raceway surface occurs during swaging, the accuracy of the calculated preload gap reduction amount may be affected. However, it is difficult to detect abnormalities such as deformation of the inner raceway surface.

On the other hand, when calculating preload using the rotational torque before and after caulking, if an abnormality such as deformation of the inner ring raceway surface occurs during caulking, the amount of increase in rotational torque before and after caulking will increase. , it is possible to detect the occurrence of an abnormality such as a deformation of the inner ring raceway surface, and it is possible to increase the reliability when determining the suitability of the measured preload.

However, when preload is calculated using the rotational torque before and after caulking, the suitability of the preload is judged based on whether or not it is within a preset preload reference value. Therefore, there is room to further improve the reliability when determining whether or not the preload is appropriate.

Therefore, the present invention provides a preload inspection method for a wheel bearing device that can further increase the reliability when determining the suitability of the preload applied to the wheel bearing device.

That is, the first invention provides an outer member having a double-row outer raceway surface on an inner periphery, a hub wheel having a small diameter stepped portion extending in the axial direction on the outer periphery, and a hub wheel that is press-fitted into the small diameter stepped portion of the hub wheel. an inner member having a double-row inner raceway surface opposite to the double-row outer raceway surface; and a rotatable inner member that is rotatably housed between raceways of the outer member and the inner member. A preload inspection method for a wheel bearing device comprising a double row of rolling elements, wherein the inner ring is placed in contact with the hub ring in the axial direction with respect to the small diameter stepped portion of the hub ring. A first bearing that calculates a first bearing preload value of the wheel bearing device based on a press-fitting step of press-fitting to a position where they contact each other, and an axial negative clearance between the raceway surfaces and the rolling elements after the press-fitting step. a preload value calculation step; a post-press-fit rotational torque measuring step of measuring the post-press-fit rotational torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the press-fitting step; After the post-press-fitting rotational torque measuring step, a crimping step of crimping the inner end of the small-diameter stepped portion to the inner ring to form a crimped portion in the small-diameter stepped portion; A swaging degree measurement step of measuring the swaging degree of the swaging portion; and a swaging degree measurement step of measuring the swaging degree of the swaging portion; and a swaging degree measuring step of measuring the swaging degree of the swaging portion; and a swaging degree measuring step of measuring the swaging degree of the crimping portion; a rotational torque measurement step after caulking to measure a rotational torque after caulking; and after the press-fitting step and after the caulking step, which are determined based on the differential torque between the rotational torque after press-fitting and the rotational torque after caulking. a second bearing preload value calculation step of calculating a second bearing preload value by adding the preload change amount between to the first bearing preload value; A first determination step of determining whether or not the preload applied to the wheel bearing device is appropriate depending on whether or not it is within a range; and a first determination step of comparing the caulking degree and the value of the differential torque; A preload inspection method for a wheel bearing device, comprising: a second determination step of determining the presence or absence of caulking abnormality depending on whether the value of the differential torque with respect to the degree of tightening is within a torque reference value range. be.

The present invention has the following effects.

That is, according to the first invention, it is possible to further increase the reliability when determining the suitability of the preload applied to the wheel bearing device.

It is a side sectional view showing a wheel bearing device in which a preload inspection method is implemented. It is a figure showing the flow of a preload inspection method. FIG. 3 is a side sectional view showing the wheel bearing device in which the inner ring is temporarily press-fitted into the small diameter stepped portion of the hub ring. FIG. 3 is a side cross-sectional view showing the wheel bearing device in which the inner ring is press-fitted into the small-diameter stepped portion of the hub ring. FIG. 3 is a diagram showing the relationship between time and torque when a hub ring and an outer ring are rotated relative to each other. It is a figure which shows the relationship between rotation speed and torque when a hub ring and an outer ring are rotated relatively. FIG. 2 is a side cross-sectional view showing the wheel bearing device in which the small-diameter step portion of the hub wheel is being caulked. FIG. 3 is a side sectional view showing the wheel bearing device in a state where the height and outer diameter of the caulked portion are being measured using a contact-type measuring device. FIG. 3 is a side sectional view showing the wheel bearing device in a state where the height dimension of the caulked portion is being measured using a non-contact measuring device. FIG. 3 is a diagram showing the relationship between bearing preload and rotational torque. (a) is a diagram showing the relationship between the height dimension of the caulked part and the differential torque, and (b) is a diagram showing the relationship between the outer diameter dimension of the caulked part and the differential torque. FIG. 7 is a side cross-sectional view showing how the inner seal member is attached to the inner end of the outer ring after the post-crimping rotational torque measurement process.

[Wheel bearing device]
A wheel bearing device 1, which is a first embodiment of a wheel bearing device in which a preload inspection method according to the present invention is implemented, will be described below with reference to FIG.

A wheel bearing device 1 shown in FIG. 1 rotatably supports a wheel in a suspension system of a vehicle such as an automobile. The wheel bearing device 1 has a configuration called third generation, and includes an outer ring 2 as an outer member, a hub ring 3 and an inner ring 4 as inner members, and two rows of inner wheels as rolling rows. It includes a side ball row 5, an outer ball row 6, an inner seal member 9, and an outer seal member 10. Here, the inner side refers to the vehicle body side of the wheel bearing device 1 when attached to the vehicle body, and the outer side refers to the wheel side of the wheel bearing device 1 when attached to the vehicle body. Further, the axial direction refers to a direction along the rotation axis of the wheel bearing device 1.

An inner opening 2a into which an inner seal member 9 can be fitted is formed at the inner end of the outer ring 2. An outer opening 2b into which the outer seal member 10 can be fitted is formed at the outer end of the outer ring 2. The inner peripheral surface of the outer ring 2 is formed with an inner outer raceway surface 2c and an outer outer raceway surface 2d. A vehicle body attachment flange 2e for attaching the outer race 2 to a vehicle body side member is integrally formed on the outer peripheral surface of the outer race 2. The vehicle body mounting flange 2e is provided with a bolt hole 2g into which a fastening member (here, a bolt) for fastening the vehicle body side member and the outer ring 2 is inserted.

At the inner end of the hub ring 3, a small-diameter stepped portion 3a is formed on the outer circumferential surface, the diameter of which is smaller than that of the outer end. A shoulder portion 3e is formed at the outer end of the small diameter stepped portion 3a of the hub ring 3. A wheel attachment flange 3b for attaching a wheel is integrally formed at the outer end of the hub wheel 3. The wheel attachment flange 3b is provided with a bolt hole 3f into which a hub bolt for fastening the hub wheel 3 and a wheel or a brake component is press-fitted.

The hub ring 3 is provided with an inner raceway surface 3c on the outer side so as to face the outer raceway surface 2d on the outer side of the outer ring 2. A lip sliding surface 3d on which the outer seal member 10 slides is formed on the base side of the wheel attachment flange 3b of the hub wheel 3. The outer seal member 10 fits into the outer open end of the annular space formed by the outer ring 2 and the hub ring 3. The hub wheel 3 has an outer end surface 3g at an end on the outer side of the wheel mounting flange 3b.

An inner ring 4 is provided on the small diameter stepped portion 3a of the hub ring 3. The inner ring 4 is fixed to the small diameter stepped portion 3a of the hub ring 3 by press-fitting and caulking. The inner ring 4 applies preload to an inner ball row 5 and an outer ball row 6, which are rolling rows. The inner ring 4 has an inner end surface 4b at its inner end, and an outer end surface 4c at its outer end. A caulking portion 3h is formed at the inner end of the hub ring 3 and is caulked to the inner end surface 4b of the inner ring 4.

An inner raceway surface 4a is formed on the outer peripheral surface of the inner ring 4. That is, on the inner side of the hub ring 3, the inner ring 4 forms an inner raceway surface 4a. An inner raceway surface 4a of the inner ring 4 faces an inner outer raceway surface 2c of the outer ring 2.

The inner ball row 5 and the outer ball row 6, which are rolling rows, are constituted by a plurality of balls 7, which are rolling elements, held by a retainer 8. The inner ball row 5 is rotatably sandwiched between the inner raceway surface 4a of the inner ring 4 and the inner outer raceway surface 2c of the outer ring 2. The outer ball row 6 is rotatably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer raceway surface 2d on the outer side of the outer ring 2.

In the wheel bearing device 1, an outer ring 2, a hub ring 3, an inner ring 4, an inner ball row 5, and an outer ball row 6 constitute a double row angular contact ball bearing. Note that the wheel bearing device 1 may be constituted by a double-row tapered roller bearing.

[Preload inspection method]
Next, a preload inspection method for the wheel bearing device 1 will be explained. As shown in FIG. 2, the preload inspection method in this embodiment is carried out during the assembly of the wheel bearing device 1. Specifically, the preload inspection method includes a temporary press-fitting process (S01), a press-fitting process (S02), a first bearing preload value calculation process (S03), a break-in process (S04), and a rotational torque measurement process after press-fitting (S05). , caulking process (S06), caulking degree measurement process (S07), rotational torque measurement process after caulking (S08), second bearing preload value calculation process (S09), first determination process (S10), It includes a second determination step (S11) and an inner side seal member mounting step (S12). Each step of the preload inspection method will be explained below.

(Temporary press-in process)
As shown in FIG. 3, the hub wheel 3 is placed on the support base 11 with its axial direction being vertical and the outer end surface 3g facing downward. An outer end surface 3g of the hub wheel 3 is in contact with the support base 11. The outer ring 2 is rotatably mounted on the hub wheel 3 placed on the support stand 11 via an inner ball row 5 and an outer ball row 6. An outer seal member 10 is fitted to the outer end of the outer ring 2 . Grease is filled between the hub ring 3 and the outer ring 2.

In the temporary press-fitting step (S01), first, the inner ring 4 is temporarily press-fitted into the small diameter stepped portion 3a of the hub wheel 3 placed on the support stand 11. Temporary press-fitting of the inner ring 4 is performed by press-fitting the inner ring 4 into the small-diameter stepped portion 3a from above, and stopping the press-fitting just before the outer end surface 4c of the inner ring 4 comes into contact with the shoulder portion 3e of the hub ring 3. Here, the press-fitting operation of the inner ring 4 is performed while applying a predetermined pressure using a pushing device such as a hydraulic cylinder or an air cylinder. At the time when the temporary press-fitting of the inner ring 4 is completed, a positive axial clearance G0 exists between the raceway surfaces (for example, the outer raceway surface 2c and the inner raceway surface 4a) and the rolling elements. This axial positive gap G0 can be measured, for example, from the amount of axial movement of the outer ring 2.

In the temporary press-fitting process (S01), a positive axial clearance G0 between the raceway surfaces (for example, the outer raceway surface 2c and the inner raceway surface 4a) and the rolling elements, and the outer side end surface of the hub ring 3 after the inner ring 4 is temporarily press-fitted. 3g and the axial dimension H0 between the inner end surface 4b of the inner ring 4. The axial dimension H0 can be measured with a measuring device 12 such as a dial gauge.

(Press-fitting process)
A press-fitting process (S02) is performed after the temporary press-fitting process (S01). As shown in FIG. 4, in the press-fitting step (S02), the inner ring 4 is press-fitted into the small diameter stepped portion 3a until the outer end surface 4c of the inner ring 4 contacts the shoulder portion 3e of the hub ring 3. After the press-fitting of the inner ring 4 into the small-diameter stepped portion 3a is completed, the axial dimension H1 between the outer end surface 3g of the hub ring 3 and the inner end surface 4b of the inner ring 4 after the press-fitting of the inner ring 4 is measured. In addition, by subtracting the value obtained by subtracting the axial dimension H1 from the axial dimension H0 from the axial positive gap G0 between the raceway surface and the rolling elements measured in the preliminary press-fitting step (S01), the orbit after press-fitting the inner ring 4 can be calculated. The axial negative clearance G1 between the surface and the rolling element is determined (G1=G0-(H0-H1)).

(First bearing preload value calculation step)
After the press-fitting step (S02), a first bearing preload value calculation step (S03) is performed. In the first bearing preload value calculation step (S03), the first bearing preload value P1 given to the bearing after the press-fitting process is calculated based on the axial negative clearance G1 found in the press-fitting process (S02). do. The first bearing preload value P1 is determined by determining the relationship between the axial negative clearance G1 and the bearing preload value in the wheel bearing device 1 through experiments, etc. Calculated by fitting the negative gap G1. Note that the relationship between this axial negative clearance and the bearing preload value can be determined for each specification of the wheel bearing device 1.

(Familiarization process)
A break-in step (S04) is performed after the first bearing preload value calculation step (S03). In the breaking-in step (S04), by relatively rotating the hub ring 3 into which the inner ring 4 is press-fitted and the outer ring 2, the grease filled between the hub ring 3 and the outer ring 2 is transferred to the inner ball. Apply it to the balls 7 in row 5 and outer ball row 6. In the breaking-in step (S04), the outer ring 2 may be fixed and the hub ring 2 may be rotated, or the hub ring 3 may be fixed and the outer ring 2 may be rotated.

By performing the break-in step (S04), the resistance generated between the grease and the balls 7 can be made constant when the hub ring 3 and the outer ring 2 are rotated relative to each other. As a result, when the rotational torque of the wheel bearing device 1 is measured in the rotational torque measurement process after press-fitting (S05) and rotational torque measurement process after caulking (S08), which will be carried out later, variations occur in the measured rotational torque. It becomes possible to suppress this. In addition, in the breaking-in step (S04), from the viewpoint of suppressing variations in rotational torque, it is preferable to relatively rotate the hub ring 3 and the outer ring 2 by 30 rotations or more.

(Rotational torque measurement process after press-fitting)
After the break-in step (S04), a post-press-fit rotational torque measurement step (S05) is performed. In the post-press-fitting rotational torque measuring step (S05), the post-press-fitting rotational torque Ta when the hub ring 3 with the inner ring 4 press-fitted into the small diameter stepped portion 3a and the outer ring 2 are relatively rotated is measured using a torque measuring device. 13. The post-press-fitting rotational torque Ta is the rotational torque measured after the press-fitting process (S02) and before the caulking process (S06). In the rotational torque measuring step after press-fitting (S05), the outer ring 2 may be fixed and the hub ring 3 may be rotated, or the hub ring 3 may be fixed and the outer ring 2 may be rotated.

When the hub ring 3 is rotated, the revolution speed of the balls 7 in the inner ball row 5 and the outer ball row 6 is slower than when the outer ring 2 is rotated, and the rotational speed of the hub ring 3 changes. It is preferable to rotate the hub wheel 3 in the rotational torque measurement step because the variation in the rotational torque values measured in the rotational torque measurement step is reduced. In addition, when rotating the hub ring 3, the hub ring 3 can be rotated by rotating the support base 11 on which the hub ring 3 is placed.

Furthermore, in the post-press-fitting rotational torque measuring step (S05), the rotational torque is measured instead of the starting torque of the bearing. As shown in FIG. 5, the starting torque is the peak value of the initial torque when the bearing starts rotating, but it decreases as time passes, and changes significantly over time. Therefore, repeatability is poor. On the other hand, the rotational torque is the torque after the bearing starts rotating, and exhibits a constant value with almost no change over time. Therefore, in the post-press-fitting rotational torque measuring step (S05), by measuring the post-press-fitting rotational torque Ta, which is the rotational torque, it is possible to measure the torque value of the bearing with high precision.

As shown in FIG. 6, when the hub ring 3 and the outer ring 2 are rotated relative to each other, the rotational torque of the bearing increases in the range where the rotation speed of the hub ring 3 or the outer ring 2 is above a certain value. However, when the rotation speed of the hub ring 3 or the outer ring 2 is extremely small, it decreases as the rotation speed rises, and then starts to increase. In other words, there is a region in which the rotational torque of the bearing changes from decreasing to increasing as the rotational speed increases, and in that region, the degree of variation in the rotational torque with respect to changes in the rotational speed is small.

In the rotational torque measuring step after press-fitting (S05), the hub ring 3 or the outer ring 2 is rotated at a constant rotational speed so that there is no variation in the measured rotational torque. Further, the rotational speed of the hub ring 3 or the outer ring 2 is set within a rotational speed range of N1 to N2 in a region where the rotational torque changes from decreasing to increasing. Thereby, even if the rotational speed changes during the measurement of the rotational torque Ta after press-fitting, it is possible to reduce the variation in the rotational torque.

In the rotational torque measuring step after press-fitting (S05), the rotational torque is measured in a state where dynamic frictional force is generated between the inner members 3 and 4 and the outer member 2. Specifically, dynamic frictional force is generated between the inner members 3, 4 and the rolling elements 7, between the hub ring 3 and the outer seal member 10, and between the outer ring 2, the rolling elements 7, and the outer seal member 10. The rotational torque is being measured while this is occurring. In general, the dynamic friction coefficient is smaller than the static friction coefficient and has less variation, so rotational torque can be measured with high precision.

The rotational speed N1, which is the lower limit of the rotational speed range, is preferably set to 10 rotations/min, which makes it possible to measure the rotational torque while dynamic frictional force is occurring. The rotation speed N2, which is the upper limit of the rotation speed range, is preferably set to 60 rotations/min, which is the rotation speed at which the stirring resistance of the grease filled between the hub ring 3 and the outer ring 2 is as small as possible. In the present embodiment, the rotational speed of the hub ring 3 or the outer ring 2 is set between 10 rotations/min and 30 rotations, at which fluctuations in rotational torque with respect to changes in rotational speed are the smallest within the range of 10 rotations/min to 60 rotations/min. The rotation speed is set to be 1/min. This makes it possible to measure rotational torque with high precision.

In this way, in the post-press-fitting rotational torque measuring step (S05), the hub ring 3 or the outer ring 2 is rotated in a small rotational speed range of N1 to N2 in which the degree of variation in rotational torque with respect to changes in rotational speed is small. As a result, even if the rotational speed of the hub ring 3 or the outer ring 2 changes, fluctuations in the rotational torque can be minimized, and the rotational torque can be measured with high precision.

In addition, in the post-press-fitting rotational torque measurement step (S05), the wheel bearing device is 1 rotational torque is measured. Here, since the outer side seal member 10 is located on the opposite side in the axial direction from the small diameter stepped portion 3a of the hub ring 3 which is crimped to fix the inner ring 4, the crimping step (S06) described below is performed. In this case, even if an abnormality occurs on the inner ring raceway surface 4a or the like, the sealing torque of the outer seal member 10 is hardly affected, and the rotational torque of the wheel bearing device 1 is also unlikely to change.

(Facing process)
A caulking process (S06) is performed after the rotational torque measurement process (S05) after press-fitting. In the caulking process (S06), caulking is performed to caulk the inner end of the small diameter stepped portion 3a of the hub ring 3 to the inner end surface 4b of the inner ring 4. By performing the crimping process, a crimped part 3h is formed at the inner end of the small diameter stepped part 3a.

As shown in FIG. 7, the crimping process can be performed by swing crimping using a crimping tool such as a crimping punch 14, for example. The crimping process by the swing crimping process is performed, for example, by lowering the crimping punch 14 disposed above the small-diameter step 3a of the hub ring 3 and bringing it into contact with the inner end of the small-diameter step 3a. This is done by swinging the crimping punch 14 that is in contact with the stepped portion 3a. After the caulking process is performed, an axial negative gap is created between the inner ring 4 and the hub ring 3.

(Facing degree measurement process)
After the caulking process (S06), a caulking degree measuring process (S07) is performed. In the caulking degree measuring step (S07), the degree of caulking of the caulking portion 3h formed by the caulking process is measured.

Here, the degree of caulking is the degree of deformation of the caulked portion 3h that is plastically deformed by the caulking process, and can be expressed by the shape of the caulked portion 3h. Further, the shape of the caulking portion 3h to be measured includes a height dimension h of the caulking portion 3h in the axial direction, an outer diameter dimension r of the caulking portion 3h in a direction perpendicular to the axial direction, and the like. In other words, the degree of caulking includes the height h of the caulked portion 3h in the axial direction, and the outer diameter dimension r of the caulked portion 3h in the direction perpendicular to the axial direction.

In this embodiment, the degree of caulking of the caulking portion 3h is measured by measuring the height dimension h and the outer diameter dimension r. However, the degree of caulking of the caulked portion 3h can also be measured by measuring only one of the height dimension h and the outer diameter dimension r.

As shown in FIG. 8, the height h and outer diameter r, which are the degree of caulking of the caulked portion 3h, can be measured using, for example, a measuring device 15. The measuring device 15 is a contact type measuring device that performs measurement by bringing a contact into contact with the caulking portion 3h, and includes a main body portion 151, a first contact 152, and a second contact 153.

The main body portion 151 is a long member extending along a direction perpendicular to the axial direction, and supports the first contactor 152 so as to be movable along the direction perpendicular to the axial direction.

The first contacts 152 are elongated members extending along the axial direction, and a pair of the first contacts 152 are provided in the main body portion 151 . When measuring the height dimension h and the outer diameter dimension r, the first contactor 152 contacts the inner end surface 4b of the inner ring 4 and the outer diameter edge of the caulked portion 3h in a direction perpendicular to the axial direction. .

The second contact 153 is an elongated member extending along a direction perpendicular to the axial direction, and is supported by the first contact 152 so as to be movable along the axial direction. The second contactor 153 comes into contact with the inner end surface in the axial direction of the caulking portion 3h when measuring the height dimension h and the outer diameter dimension r.

When measuring the height dimension h of the caulking portion 3h using the measuring instrument 15 configured as described above, the second contact 153 is moved along the axial direction with respect to the first contact 152. , the tip of the first contact 152 is brought into contact with the inner end surface 4b of the inner ring 4, and the second contact 153 is brought into contact with the inner end surface of the caulked portion 3h. Thereafter, by measuring the length in the axial direction from the tip of the first contact 152 to the second contact 153, the inner side of the crimped part 3h is Measure the axial dimension to the side end face

In addition, when measuring the outer diameter dimension r of the caulking portion 3h using the measuring device 15, the first contactor 152 is moved in a direction perpendicular to the axial direction with respect to the main body portion 151, and the first contact The child 152 is brought into contact with the outer diameter edge of the caulking portion 3h. Thereafter, by measuring the length between the first contacts 152 in the direction perpendicular to the axial direction, the outer diameter dimension r of the caulked portion 3h is measured.

In the present embodiment, the degree of caulking of the caulking portion 3h is measured using the measuring device 15 having the main body portion 151, the first contact 152, and the second contact 153. However, the degree of caulking of the caulking portion 3h can also be measured using a contact-type measuring device having another configuration. In this way, when the degree of caulking is measured using a contact type measuring device, it is easy to make the measuring device simple in configuration.

Furthermore, the degree of caulking of the caulked portion 3h can be measured using a non-contact measuring instrument that measures without touching the caulked portion 3h. As a non-contact measuring device, for example, as shown in FIG. 9, a laser displacement meter can be used, which measures the height h etc. of the caulked portion 3h by irradiating the caulked portion 3h with a laser beam. Furthermore, it is also possible to measure the height dimension h, outer diameter dimension r, etc. of the caulking part 3h by taking an image of the caulking part 3h and processing the imaged image of the caulking part 3h. In this way, when the degree of caulking is measured using a non-contact measuring device, the measurement can be performed without contacting the caulked portion 3h, so that the wheel bearing device 1 can be assembled. It becomes easy to measure the caulking degree on the production line.

(Rotational torque measurement process after caulking)
After the caulking degree measuring process (S07), a post-caulking rotational torque measuring process (S08) is carried out. In the rotational torque measurement step after caulking (S08), similarly to the rotational torque measurement step after press-fitting, the rotational torque is measured while dynamic frictional force is generated between the inner members 3, 4 and the outer member 2. Measuring. In the rotational torque measurement step after caulking (S08), the rotational torque Tb after caulking when the small-diameter stepped portion 3a relatively rotates the hub ring 3 and the outer ring 2, which are caulked to the inner ring 4, is calculated as the torque. Measurement is performed using a measuring device 13. The rotational torque Tb after caulking is the rotational torque measured after the caulking process (S06) and before the inner side seal member mounting process (S12). In the rotational torque measurement step after caulking (S08), the outer ring 2 may be fixed and the hub ring 3 may be rotated, or the hub ring 3 may be fixed and the outer ring 2 may be rotated. .

However, as in the case of the rotational torque measurement step after press-fitting (S05), rotating the hub ring 3 reduces the variation in the rotational torque value measured when the rotational speed of the hub ring 3 changes. preferable. Also, in the rotational torque measurement step after caulking (S08), as in the rotational torque measurement step after press-fitting (S05), the rotational torque is measured instead of the starting torque of the bearing, and the hub ring 3 or outer ring 2 is rotated at a low speed. By measuring the rotational torque Tb after caulking while rotating at a constant rotational speed between N1 and N2, it is possible to measure the rotational torque with high precision.

In this case, the rotation speed N1 and the rotation speed N2 are set to 10 rotations/min and the rotation speed N2 to 60 rotations/min, as in the case of the post-press-fitting rotation torque measurement step (S05). It is preferable. In the present embodiment, the rotational speed of the hub ring 3 or the outer ring 2 is set between 10 rotations/min and 30 rotations, at which fluctuations in rotational torque with respect to changes in rotational speed are the smallest within the range of 10 rotations/min to 60 rotations/min. The rotation speed is set to be 1/min. As a result, even if the rotational speed changes during the measurement of the rotational torque Tb after caulking, the fluctuation in the rotational torque Tb after caulking can be reduced, and it is possible to stably measure the rotational torque. .

In addition, in this embodiment, the rotational torque measurement step after caulking (S08) is performed after the caulking degree measurement step (S07); It is also possible to perform a processing degree measuring step (S07).

Also, between the caulking process (S06) and the rotational torque measurement process after caulking (S08), a process similar to the breaking-in process (S04) is performed, that is, the space between the hub ring 3 and the outer ring 2 is filled. A step of blending the grease into the balls 7 of the inner ball row 5 and the outer ball row 6 can be performed. As a result, the resistance generated between the grease and the balls 7 when the hub ring 3 and the outer ring 2 are rotated relative to each other can be made constant, and the wheel When measuring the rotational torque Tb after caulking of the bearing device 1, it is possible to further suppress variations in the measured rotational torque Tb after caulking.

However, if the grease and the ball 7 are sufficiently familiar with each other by performing the breaking-in step (S04) and the resistance generated between the grease and the ball 7 is constant, the tightening step (S06) is performed. It is possible to omit the run-in process between the rotational torque measurement process (S08) and the post-crimping rotational torque measurement process (S08).

(Second bearing preload value calculation process)
A second bearing preload value calculation step (S09) is performed after the post-crimping rotational torque measurement step (S08). In the second bearing preload value calculation step (S09), a differential torque ΔT (Tb−Ta=ΔT) between the post-press-fit rotational torque Ta and the post-crimping rotational torque Tb is calculated. Furthermore, the preload change amount ΔP between after the press-fitting process and after the caulking process is determined based on the differential torque ΔT. Furthermore, a second bearing preload value P2 is calculated by adding the preload change amount ΔP to the first bearing preload value P1 calculated in the first bearing preload value calculation step (S03).

In this case, the differential torque ΔT is the rotational torque increased by the caulking process performed in the caulking step (S06). Further, the preload change amount ΔP is the preload increased by the crimping process performed in the crimping process (S06). As shown in FIG. 10, the preload change amount ΔP is calculated by determining the relationship between the bearing preload of the wheel bearing device 1 and the rotational torque of the bearing in advance through experiments, etc., and applying the differential torque ΔT to this relationship. do. Note that the relationship between the bearing preload and the rotational torque of the bearing can be determined for each specification of the wheel bearing device 1.

(First judgment step)
The first determination step (S10) is performed after the second bearing preload value calculation step (S09). In the first determination step (S10), the suitability of the preload applied to the wheel bearing device 1 is determined based on whether the second bearing preload value P2 is within the range of the preload reference value. In the first determination step (S10), if the second bearing preload value P2 is within the preload reference value range, it is determined that the preload applied to the wheel bearing device 1 is appropriate; If the bearing preload value P2 of No. 2 is not within the range of the preload reference value, it is determined that the preload applied to the wheel bearing device 1 is not appropriate.

In the second bearing preload value calculation step (S09), the preload change amount ΔP due to swaging was calculated using the post-press-fit rotational torque Ta and the post-swaging rotational torque Tb, which are the rotational torques before and after swaging. Then, the second bearing preload value P2 is calculated.

In this way, when calculating preload using the rotational torque before and after caulking, for example, if an abnormality such as deformation of the inner ring raceway surface occurs during caulking, the amount of increase in rotational torque before and after caulking is As a result, the calculated second bearing preload value P2 falls outside the range of the preload reference value. Therefore, by determining the calculated second bearing preload value P2 in the first determination step (S10), an abnormality such as deformation of the inner ring raceway surface has occurred in the wheel bearing device 1 after caulking. It becomes possible to detect this, and the reliability of the measured value of the preload applied to the wheel bearing device 1 can be increased. Thereby, it becomes possible to inspect the preload applied to the wheel bearing device 1 with higher reliability.

Further, the post-press-fit rotational torque Ta and the post-crimping rotational torque Tb used before and after the caulking process when calculating the second bearing preload value P2 are values measured for the same wheel bearing device 1. Therefore, the difference torque ΔT between the rotational torque Ta after press-fitting and the rotational torque Tb after caulking is determined by the lip tightening margin of the outer seal member 10 and the amount of grease filled between the hub ring 3 and the outer ring 2, etc. It does not include variations among individual bearing devices 1, and only the amount of increase in rotational torque due to caulking is extracted. Thereby, the second bearing preload value P2 can be calculated with high precision from the differential torque ΔT, and the suitability of the preload applied to the wheel bearing device 1 can be determined with high precision in the first determination step (S10). It is possible to judge.

In addition, the reference value used when determining the suitability of the preload in the first determination step (S10) takes into account variations in rotational torque caused by caulking the small diameter stepped portion 3a to the inner ring 4. It is set.

In other words, the difference between the post-press-fitting rotational torque Ta and the post-staking rotational torque Tb is the movement of the position of the grease between the hub ring 3 and the outer ring 2 before and after the swaging process, and the hub of the outer seal member 10. Variations caused by changes in the contact with the ring 3 and the outer ring 2 may be included. Further, there may be repeated variations in the rotational torque measurement between the post-press-fit rotational torque Ta measured before the crimping process and the post-crimping rotational torque Tb measured after the crimping process.

Therefore, in this embodiment, in consideration of these variations, the range of the preload reference value is set to a narrower range than in the case where the variations are not considered. Thereby, the suitability of the preload applied to the wheel bearing device 1 can be determined with high precision in the first determination step (S10), and it is possible to suppress the occurrence of erroneous determination. .

(Second judgment step)
After the first determination step (S10), a second determination step (S11) is performed. In the second determination step (S11), the degree of caulking of the caulking portion 3h and the value of the differential torque ΔT are compared, and the value of the differential torque ΔT with respect to the degree of caulking of the caulking portion 3h is the torque reference value. The presence or absence of caulking abnormality is determined based on whether or not it is within the range of .

Specifically, as shown in FIG. 11(a), a first relationship line X1 representing the relationship between the height h of the caulked portion 3h and the differential torque ΔT is determined in advance through experiments, etc., and the height h The range between the upper limit value X1U and the lower limit value X1L of the value of the differential torque ΔT is set in advance as the range R1 of the first torque reference value when determining the presence or absence of caulking abnormality. In addition, as shown in FIG. 11(b), a second relationship line X2 representing the relationship between the outer diameter dimension r of the caulked portion 3h and the differential torque ΔT is determined in advance through experiments, etc., and the differential torque with respect to the outer diameter dimension r is determined in advance. The range between the upper limit value X2U and the lower limit value X2L of the value of ΔT is set in advance as the range R2 of the second torque reference value when determining the presence or absence of caulking abnormality.

Then, the height dimension h and outer diameter dimension r of the caulking portion 3h are compared with the value of the differential torque ΔT, and the value of the differential torque ΔT with respect to the height dimension h is within the range R1 of the first torque reference value. The presence or absence of caulking abnormality is determined based on whether the torque difference ΔT with respect to the outer diameter dimension r is within the range R2 of the second torque reference value.

In this case, for example, when comparing the height dimension h and the outer diameter dimension r with the value of the differential torque ΔT, the value of the differential torque ΔT with respect to the height dimension h is within the range R1 of the first torque reference value. , and if the value of the differential torque ΔT with respect to the outer diameter dimension r is within the range R2 of the second torque reference value, it is determined that no caulking abnormality has occurred. Also, when comparing the height dimension h and outer diameter dimension r with the value of the differential torque ΔT, check whether the value of the differential torque ΔT with respect to at least the height dimension h is within the range R1 of the first torque reference value. , or when the value of the differential torque ΔT with respect to the outer diameter dimension r is not within the range R2 of the second torque reference value, it is determined that a caulking abnormality has occurred.

In this way, by determining whether or not there is a crimping abnormality based on the crimping degree represented by the crimping shape such as the height h and the outer diameter r of the crimped part 3h, for example, the crimped part 3h It becomes possible to detect deformation of the inner raceway surface 4a of the inner ring 4 due to the deviation of the shape. In this case, the presence or absence of caulking abnormality is determined by comparing the degree of caulking of the caulking portion 3h and the value of the differential torque ΔT. It is possible to detect not only deformation of the surface 4a but also small deformation of the inner raceway surface 4a.

In addition, in this preload inspection method, the height dimension h and the outer diameter dimension r are used as the caulking degree to be measured, but the height dimension h and the outer diameter dimension r are relatively easy to measure. Therefore, it is possible to measure the degree of caulking on a mass production line without reducing production efficiency.

In addition, in the second determination step (S11), the determination result of the suitability of preload in the first determination step (S10) and the determination result of the presence or absence of caulking abnormality in the second determination step (S11) are used. Based on this, it is determined whether the wheel bearing device 1 after caulking is a good product.

For example, when it is determined in the first determination step (S10) that the preload of the wheel bearing device 1 is appropriate, and in the second determination step (S11) it is determined that no caulking abnormality has occurred, It is determined that the wheel bearing device 1 after tightening is a good product. Further, if it is determined that the preload of the wheel bearing device 1 is not appropriate in at least the first determination step (S10), or it is determined that a caulking abnormality has occurred in the second determination step (S11). In this case, it is determined that the wheel bearing device 1 after caulking is not a good product.

In this way, by performing the second determination step (S11) in addition to the first determination step (S10), the determination of whether or not the preload is appropriate in the first determination step (S10) can be performed in the second determination step. This can be supplemented by determining the presence or absence of crimping abnormality in (S11). Thereby, it is possible to further increase the reliability when determining the suitability of the preload applied to the wheel bearing device 1, and to manufacture a higher quality wheel bearing device 1.

In addition, by measuring the degree of caulking such as height dimension h and outer diameter dimension r in the preload inspection method, the shape of the caulked part 3h can be grasped, and the shape of the caulked part 3h can be Based on this, the crimping conditions can be set, and the crimping portion 3h can be adjusted to an appropriate shape. Thereby, the shape of the caulked portion 3h can be leveled at multiple manufacturing sites and manufacturing lots, and it is possible to manufacture wheel bearing devices 1 of uniform quality.

In this embodiment, both the height h and the outer diameter r are measured to measure the degree of caulking, but only one of the height h and the outer diameter r is caulked. It is also possible to measure the degree of processing. In this way, even when one of the height dimension h and the outer diameter dimension r is measured, the reliability when determining the appropriateness of the preload applied to the wheel bearing device 1 is further increased, and higher quality is achieved. It is possible to manufacture a wheel bearing device 1 that has the following characteristics.

However, the presence or absence of caulking abnormality can be determined more accurately when both the height dimension h and the outer diameter dimension r are measured than when one of the height dimension h and the outer diameter dimension r is measured. This makes it possible to further increase the reliability when determining whether or not the preload is appropriate.

Further, in the present embodiment, after determining whether or not the preload is appropriate in the first determining step (S10), the presence or absence of caulking abnormality is determined in the second determining step (S11). After determining the presence or absence of caulking abnormality in the first determination step (S10), it is also possible to determine whether or not the preload is appropriate in the second determination step (S11).

(Inner side seal member installation process)
After the second determination step (S11), an inner seal member mounting step (S12) is performed. By carrying out the inner side seal member mounting step (S12), the assembly step of the wheel bearing device 1 is completed. In addition, if the inner side seal member installation step (S12) is after the rotational torque measurement step after caulking (S08), it may be performed before the second determination step (S11) or before the first determination step (S10). Alternatively, it can also be performed before the second bearing preload value calculation step (S09). As shown in FIG. 12, in the inner side seal member mounting step (S12), the inner side end of the outer ring 2 and the inner ring 4 are fitted by fitting the inner side seal member 9 into the inner side opening 2a of the outer ring 2. An inner side seal member 9 is installed between the inner side end portion of the inner side end portion.

If the inner seal member 9 is installed before the crimping process (S06), the sliding between the inner ring 2 and the inner ring 4 of the inner seal member 9 may occur depending on the degree of crimping of the hub ring 3 in the crimping process (S06). Dynamic resistance changes. Furthermore, if the inner side seal member 9 is installed after the swage process (S06) but before the post-swage rotational torque measurement process (S08), the inner side seal member 9 The sliding resistance between the outer ring 2 and the inner ring 4 changes.

Therefore, if the inner side seal member 9 is installed before the caulking process (S06) or the rotational torque measurement process after caulking (S08), the rotational torque after caulking measured in the rotational torque measurement process after caulking (S08) This may affect the variation in Tb. Similarly, if the inner side seal member 9 is installed before the post-press-fit rotational torque measurement step (S05), the press-fit measured in the post-press-fit rotational torque measurement step (S05) will depend on the installation state of the inner-side seal member 9. This may affect the variation in the post-rotation torque Ta.

However, in the present embodiment, since the inner side seal member mounting step (S12) is performed after the rotational torque measurement step after crimping (S08), the rotational torque measurement step after press-fitting (S05) and the crimping When measuring the post-press-fitting rotational torque Ta and the post-crimping rotational torque Tb of the wheel bearing device 1 in the post-rotational torque measuring step (S08), variations in the rotational torque due to the influence of the inner side seal member 9 do not occur. , it is possible to measure the rotational torque of the wheel bearing device 1 with high precision.

In this embodiment, the inner side seal member mounting step (S12) is performed after the rotational torque measurement step after crimping (S08), but the cap member mounting step is performed after the rotational torque measurement step after crimping (S08). It is also possible to adopt a configuration that implements the following. In this case, in the cap member mounting step, a cap member is fitted into the inner opening 2a of the outer ring 2 instead of the inner seal member 9, and the inner opening 2a is closed by the cap member.

In addition, in this embodiment, the wheel bearing device 1 for a driven wheel was explained, but the present preload inspection method can also be applied to a wheel bearing device for a driving wheel that is designed to caulk a hub wheel. can.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, but are merely illustrative, and various further modifications may be made without departing from the gist of the present invention. Of course, the scope of the present invention is indicated by the description of the claims, and furthermore, the meaning of equivalents described in the claims and all changes within the scope of the claims are understood. include.

1 Wheel Bearing Device 2 Outer Ring 2c (Inner Side) Outer Raceway Surface 2d (Outer Side) Outer Raceway Surface 3 Hub Ring 3a Small Diameter Step 3c Inner Raceway Surface 4 Inner Ring 4a Inner Raceway Surface 5 Inner Ball Row 6 Outer Side Ball row 7 Ball 9 Inner side sealing member 15 (Contact type) measuring device 16 (Non-contact type) measuring device h Height dimension (of the caulked part) r Outer diameter dimension (of the caulked part) G1 Axial direction negative Gap P1 First bearing preload value P2 Second bearing preload value R1 Range of first torque reference value R2 Range of second torque reference value S02 Press-fitting process S03 First bearing preload value calculation process S05 Rotational torque measurement process after press-fitting S06 crimping process S07 crimping degree measurement process S08 Post-caulking rotational torque measurement process S09 Second bearing preload value calculation process S10 First judgment process S11 Second judgment process Ta Rotational torque after press-fitting Tb Rotation after crimping Torque ΔT Differential torque ΔP Preload change amount

Claims (4)

an outer member having a double-row outer raceway surface on the inner periphery;
The inner ring includes a hub ring having a small-diameter stepped portion extending in the axial direction on the outer periphery, and an inner ring press-fitted into the small-diameter stepped portion of the hub ring, and has a double-row inner raceway surface facing the double-row outer raceway surface. A square member,
a double row of rolling elements rotatably housed between raceway surfaces of the outer member and the inner member;
A preload inspection method for a wheel bearing device comprising:
a press-fitting step of press-fitting the inner ring into the small-diameter stepped portion of the hub ring to a position where the inner ring contacts the hub ring in the axial direction;
a first bearing preload value calculation step of calculating a first bearing preload value of the wheel bearing device based on the axial negative clearance between the both raceways and the rolling elements after the press-fitting step;
a post-press-fit rotation torque measuring step of measuring the post-press-fit rotation torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the press-fit step;
After the post-press-fitting rotational torque measuring step, a crimping step of crimping an inner end of the small diameter stepped portion to the inner ring to form a crimped portion in the small diameter stepped portion;
a caulking degree measuring step of measuring the degree of caulking of the caulking portion formed in the caulking step;
a post-crimping rotational torque measuring step of measuring post-crimping rotational torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the tightening step;
Adding a preload change amount between after the press-fitting process and after the caulking process, which is determined based on the differential torque between the post-press-fitting rotational torque and the post-caulking rotational torque, to the first bearing preload value. a second bearing preload value calculation step of calculating a second bearing preload value by
a first determination step of determining whether or not the preload applied to the wheel bearing device is appropriate depending on whether the second bearing preload value is within a range of a preload reference value;
The caulking degree and the value of the differential torque are compared, and the presence or absence of caulking abnormality is determined based on whether the value of the differential torque with respect to the caulking degree is within a torque reference value range. A preload inspection method for a wheel bearing device, comprising: a second determination step. The wheel bearing according to claim 1, wherein the degree of caulking includes at least one of a height dimension of the caulked portion in the axial direction and an outer diameter dimension of the caulked portion in a direction orthogonal to the axial direction. Equipment preload inspection method. In the caulking degree measurement step,
3. The preload inspection method for a wheel bearing device according to claim 1, wherein the caulking degree is measured by a contact type measuring device that measures by bringing a contact into contact with the caulking portion. In the caulking degree measurement step,
The preload inspection method for a wheel bearing device according to claim 1 or 2, wherein the degree of caulking is measured by a non-contact measuring device that measures without contacting the caulking portion.

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