JP2022034924A - Preload inspection method of wheel bearing device - Google Patents

Abstract

To provide a preload inspection method of a wheel bearing device, capable of inspecting a preload with high reliability.SOLUTION: A preload inspection method includes: a press-fitting process S02 for press-fitting an inner ring; a first bearing preload value calculation process S03 for calculating a first bearing preload value on the basis of an axial negative clearance G1 between a raceway surface and a rolling element after the press-fitting process S02; an after-press-fitting rotational torque measurement process S05 for measuring the after-press-fitting rotational torque, after the press-fitting process; a caulking process S06 for caulking a small-diameter step portion to the inner ring after the after-press-fitting rotational torque measurement process; an after-caulking rotational torque measurement process S07 for measuring after-caulking rotational torque after the caulking process; a second bearing preload value calculation process S08 for calculating a second bearing preload value by adding a preload change amount determined from differential torque between the after-press-fitting rotational torque and the after-caulking rotational torque to the first bearing preload value by using a relationship between the rotational torque and the preload according to an atmospheric temperature; and a determination process S09 for determining propriety of the preload on the basis of whether the second bearing preload value is within a range of a reference value or not.SELECTED DRAWING: Figure 2

Description

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

Conventionally, a wheel bearing device that rotatably supports a wheel in a suspension device such as an automobile is known. In such a wheel bearing device, a preload is applied between the rolling elements constituting the bearing device and the raceway wheels.

By applying a preload to the bearing device, it is possible to increase the rigidity of the bearing device and suppress vibration and noise. However, if an excessive preload is applied, it may cause an increase in rotational torque and a decrease in life, so it is important to confirm whether an appropriate preload is applied to the bearing device.

As a method of confirming the preload applied to the bearing device, for example, as disclosed in Patent Document 1, in a rolling bearing provided with rolling elements in multiple rows, a preload gap in the axial direction is measured. A preload measuring method for measuring the preload applied to the bearing is known.

Further, in the bearing device having the structure in which the hub wheel is crimped to the inner ring, the rotational torque of the bearing device before and after the crimping process is measured, and the preload increase amount is obtained from the increase amount of the rotational torque before and after the crimping process. It is conceivable to calculate the preload applied to the bearing device by adding the preload increase amount to the preload of the bearing device before the crimping process.

Japanese Unexamined Patent Publication No. 10-185717

However, the rotational torque of the bearing device varies depending on the temperature of the bearing device at the time of measurement, even if the bearing device has the same preload gap. As a result, the reliability of the calculated preload may decrease.

Therefore, the present invention provides a preload inspection method for a wheel bearing device that can inspect the preload applied to the wheel bearing device with higher reliability by taking into account the change in rotational torque due to temperature. do.

That is, the first invention is press-fitted into an outer member having a double-row outer raceway surface on the inner circumference, a hub ring having a small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub ring. The inner member is composed of an inner ring and has a double-row inner raceway surface facing the outer raceway surface of the double-row, and is rotatably accommodated between both racecourse surfaces of the outer member and the inner member. A preload inspection method for a wheel bearing device including a double-row rolling element, wherein the inner ring hits the hub wheel with respect to the small-diameter step portion of the hub wheel, and the inner ring hits the hub wheel in the axial direction. 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 contact position and an axial negative gap between both raceway surfaces and the rolling element after the press-fitting step. A preload value calculation step, a post-press-fit rotation torque measurement step for 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, and a post-press-fit rotation torque measurement step. After the press-fitting rotation torque measurement step, the crimping step of crimping the inner end of the small diameter step portion to the inner ring, and after the crimping step, the inner member and the outer member are relatively rotated. The press-fitting obtained based on the post-crimping rotational torque measuring step of measuring the post-crimping rotational torque of the wheel bearing device at the time and the difference torque between the post-pressing rotational torque and the post-crimping rotational torque. The second bearing preload value calculation step of calculating the second bearing preload value by adding the preload change amount between the step and the crimping step to the first bearing preload value, and the second bearing preload calculation step. In the second bearing preload value calculation step, a determination step of determining the suitability of the preload applied to the wheel bearing device based on whether or not the bearing preload value of the above is within the range of the reference value is provided. Is a method for preload inspection of a wheel bearing device, characterized in that the amount of change in preload is obtained from the differential torque using the relationship between the rotational torque and the preload according to the ambient temperature.

The second invention is press-fitted into an outer member having a double row of outer raceway surfaces on the inner circumference, a hub ring having a small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub ring. The inner member is composed of an inner ring and has a double-row inner raceway surface facing the outer raceway surface of the double-row, and is rotatably accommodated between both racecourse surfaces of the outer member and the inner member. A method for preload inspection of a wheel bearing device including a double-row rolling element, wherein the inner ring hits the hub wheel with respect to the small-diameter step portion of the hub wheel, and the inner ring hits the hub wheel in the axial direction. The first bearing preload value of the wheel bearing device is calculated based on the press-fitting step of press-fitting to the contacting position and the axial negative gap between the two railing surfaces and the rolling element after the press-fitting step. A bearing preload calculation step and a post-press-fit rotation torque measurement 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 press-fitting rotation torque measurement step, the crimping step of crimping the inner end of the small diameter step portion to the inner ring, and after the crimping step, the inner member and the outer member are relatively rotated. The above-mentioned obtained based on the post-crimping rotational torque measuring step of measuring the post-crimping rotational torque of the wheel bearing device when the wheel bearing device is pressed, and the difference torque between the post-press-fit rotational torque and the post-crimping rotational torque. The second bearing preload value calculation step of calculating the second bearing preload value by adding the preload change amount between the press-fitting step and the crimping step to the first bearing preload value, and the first bearing preload value calculation step. The second bearing preload value calculation step includes a determination step of determining the suitability of the preload applied to the wheel bearing device depending on whether or not the bearing preload value of 2 is within the range of the reference value. The present invention is a method for preload inspection of a wheel bearing device, which comprises obtaining the preload change amount from the differential torque by using the relationship between the rotational torque and the preload according to the surface temperature of the wheel bearing device.

As the effect of the present invention, the following effects are exhibited.

That is, according to the first invention, the change in the rotational torque due to the ambient temperature is taken into consideration, and according to the second invention, the change in the rotational torque due to the surface temperature of the wheel bearing device is taken into consideration. The preload applied to the wheel bearing device can be inspected with higher reliability.

It is a side sectional view which shows the bearing device for a wheel which carries out the preload inspection method. It is a figure which shows the flow of the preload inspection method. It is a side sectional view showing the wheel bearing device in the state where the inner ring is temporarily press-fitted into the small diameter step portion of the hub ring. It is a side sectional view which shows the bearing device for a wheel in the state which the inner ring is press-fitted into the small diameter step part of a hub ring. It is a figure which shows the relationship between the time and torque when the hub wheel and the outer ring are relatively rotated. It is a figure which shows the relationship between the rotation speed and torque when the hub wheel and the outer ring are relatively rotated. It is a side sectional view which shows the bearing device for a wheel in the state which the small diameter step part of a hub wheel is crimped to the inner ring. It is a figure which shows the relationship between the bearing preload and the rotational torque according to the atmospheric temperature. It is a figure which shows the relationship between a bearing preload and a rotational torque. It is a side sectional view showing how the inner side seal member is attached to the inner side end portion of an outer ring after a rotation torque measurement process after crimping.

[Wheel bearing device]
Hereinafter, the wheel bearing device 1 which is an embodiment of the wheel bearing device in which the preload inspection method according to the present invention is carried out will be described with reference to FIG. 1.

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

An inner side opening 2a into which the inner side sealing member 9 can be fitted is formed at the inner side end of the outer ring 2. An outer side opening 2b into which the outer side sealing member 10 can be fitted is formed at the outer side end of the outer ring 2. An outer raceway surface 2c on the inner side and an outer raceway surface 2d on the outer side are formed on the inner peripheral surface of the outer ring 2. On the outer peripheral surface of the outer ring 2, a vehicle body mounting flange 2e for attaching the outer ring 2 to the vehicle body side member is integrally formed. 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 side end portion of the hub ring 3, a small diameter step portion 3a having a diameter smaller than that of the outer side end portion is formed on the outer peripheral surface. A shoulder portion 3e is formed at the outer side end portion of the small diameter step portion 3a in the hub ring 3. A wheel mounting flange 3b for mounting a wheel is integrally formed at the outer end of the hub wheel 3. The wheel mounting flange 3b is provided with a bolt hole 3f into which a hub bolt for fastening the hub wheel 3 to the 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 to which the outer side sealing member 10 slides is formed on the base side of the wheel mounting flange 3b in the hub wheel 3. The outer side seal member 10 is fitted to the outer 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 step portion 3a of the hub ring 3. The inner ring 4 is fixed to the small diameter step portion 3a of the hub ring 3 by press fitting and crimping. The inner ring 4 applies a preload to the inner ball row 5 and the outer ball row 6 which are rolling rows. The inner ring 4 has an inner side end surface 4b at the inner side end portion and an outer side end surface 4c at the outer side end portion. A crimping portion 3h that is crimped to the inner side end surface 4b of the inner ring 4 is formed at the inner side end portion of the hub ring 3.

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 raceway surface 4a is formed by the inner ring 4. The inner raceway surface 4a of the inner ring 4 faces the outer raceway surface 2c on the inner side of the outer ring 2.

The inner side ball row 5 and the outer side ball row 6 which are rolling rows are configured by holding a plurality of balls 7 which are rolling elements by a cage 8. The inner ball row 5 is rotatably sandwiched between the inner raceway surface 4a of the inner ring 4 and the outer raceway surface 2c on the inner side 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, a double row angular contact ball bearing is composed of an outer ring 2, a hub ring 3, an inner ring 4, an inner ball row 5, and an outer ball row 6. The wheel bearing device 1 may be composed of a double-row conical roller bearing.

[Preload inspection method]
Next, a preload inspection method for the wheel bearing device 1 will be described. As shown in FIG. 2, the preload inspection method in the present embodiment is performed 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 step (S03), a familiar process (S04), and a post-press-fitting rotational torque measurement step (S05). , A crimping step (S06), a post-crimping rotation torque measuring step (S07), a second bearing preload value calculation step (S08), a determination step (S09), and an inner side seal member mounting step (S10). There is. Each step of the preload inspection method will be described below.

(Temporary press-fitting process)
As shown in FIG. 3, the hub wheel 3 is placed on the support base 11 in a posture in which the axial direction is vertical and the outer end surface 3g is located downward. The 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 ring 3 mounted on the support base 11 via the inner ball row 5 and the outer ball row 6. The outer side seal member 10 is fitted to the outer side end portion 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 step portion 3a of the hub ring 3 mounted on the support base 11. Temporary press-fitting of the inner ring 4 is performed by press-fitting the inner ring 4 from above into the small diameter step portion 3a and stopping the press-fitting before the outer end surface 4c of the inner ring 4 abuts on the shoulder portion 3e of the hub ring 3. Here, the press-fitting operation of the inner ring 4 is performed in a state where a predetermined pressure is applied by using a pushing device such as a hydraulic cylinder or an air cylinder. When the temporary press-fitting of the inner ring 4 is completed, an axial positive gap G0 exists between the raceway surface (for example, the outer raceway surface 2c and the inner raceway surface 4a) and the rolling element. 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 step (S01), the axial positive gap G0 between the raceway surface (for example, the outer raceway surface 2c and the inner raceway surface 4a) and the rolling element, and the outer end surface of the hub ring 3 after the temporary press-fitting of the inner ring 4. The axial dimension H0 between 3 g and the inner end surface 4b of the inner ring 4 is measured. The axial dimension H0 can be measured by a measuring instrument 12 such as a dial gauge.

(Press-fitting process)
The press-fitting step (S02) is performed after the temporary press-fitting step (S01). As shown in FIG. 4, in the press-fitting step (S02), the inner ring 4 is press-fitted into the small diameter step portion 3a until the outer end surface 4c of the inner ring 4 comes into contact with the shoulder portion 3e of the hub ring 3. After the press-fitting of the inner ring 4 into the small diameter step portion 3a is completed, the axial dimension H1 between the outer side end surface 3g of the hub ring 3 and the inner side end surface 4b of the inner ring 4 after the press-fitting of the inner ring 4 is measured. Further, 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 element measured in the temporary press-fitting step (S01), the trajectory after press-fitting of the inner ring 4 Axial negative clearance G1 between the surface and the rolling element is obtained (G1 = G0- (H0-H1)).

(First bearing preload calculation process)
After the press-fitting step (S02), the first bearing preload 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 obtained in the press-fitting process (S02). do. For the first bearing preload value P1, the relationship between the axial negative clearance and the bearing preload value in the wheel bearing device 1 is obtained in advance by experiments or the like, and this relationship is obtained in the press-fitting step (S02) in the axial direction. Calculated by fitting the gap G1. The relationship between this axial negative clearance and the bearing preload value can be obtained for each specification of the wheel bearing device 1.

(Familiar process)
After the first bearing preload value calculation step (S03), the familiarization step (S04) is carried out. In the familiarization step (S04), the hub ring 3 into which the inner ring 4 is press-fitted and the outer ring 2 are relatively rotated, so that the grease filled between the hub ring 3 and the outer ring 2 is filled with the inner ball. Familiarize with the ball 7 in the row 5 and the outer ball row 6. In the familiarization 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 carrying out the familiarization step (S04), the resistance generated between the grease and the ball 7 when the hub ring 3 and the outer ring 2 are relatively rotated can be made constant. As a result, when the rotational torque of the wheel bearing device 1 is measured in the post-press-fit rotational torque measurement step (S05) and the post-crimping rotational torque measurement step (S07), the measured rotational torque varies. It is possible to suppress this. In the familiarization step (S04), it is preferable to rotate the hub ring 3 and the outer ring 2 relatively by 30 rotations or more from the viewpoint of suppressing variation in rotational torque.

(Rotation torque measurement process after press fitting)
After the familiarization step (S04), the rotational torque measurement step (S05) after press-fitting is carried out. In the press-fitting post-rotation torque measuring step (S05), the press-fitting post-rotation torque Ta when the hub ring 3 in which the inner ring 4 is press-fitted into the small diameter step portion 3a and the outer ring 2 are relatively rotated is a torque measuring instrument. Measure according to 13. The post-press-fit rotational torque Ta is a rotational torque measured after the press-fitting step (S02) and before the crimping step (S06). In the post-press-fit rotation torque measuring step (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 wheel 3 is rotated, the rotational speed of the ball 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 wheel 3 changes. It is preferable to rotate the hub wheel 3 in the rotational torque measuring step because the variation in the rotational torque value measured in 1 is small. When rotating the hub wheel 3, the hub wheel 3 can be rotated by rotating the support base 11 on which the hub wheel 3 is placed.

Further, in the post-press-fit rotational torque measurement 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 to rotate, but it decreases with the passage of time and changes greatly with time. Therefore, the reproducibility is poor. On the other hand, the rotational torque is the torque after the bearing has started to rotate, and shows a constant value with almost no change over time. Therefore, in the post-press-fit rotation torque measurement step (S05), it is possible to measure the torque value of the bearing with high accuracy by measuring the post-press-fit rotation torque Ta, which is the rotational torque.

As shown in FIG. 6, the rotational torque of the bearing when the hub wheel 3 and the outer ring 2 are relatively rotated increases in the range where the rotational speed of the hub wheel 3 or the outer ring 2 is equal to or higher than a certain value. However, when the rotation speed of the hub wheel 3 or the outer ring 2 is extremely small, it decreases as the rotation speed increases, and then increases. That is, the rotational torque of the bearing has a region where the rotational torque changes from a decrease to an increase as the rotational speed increases, and in that region, the degree of fluctuation of the rotational torque with respect to the change in the rotational speed is small.

In the post-press-fit rotation torque measurement step (S05), the hub wheel 3 or the outer ring 2 is rotated at a constant rotation speed so that the measured rotation torque does not vary. Further, the rotation speed of the hub wheel 3 or the outer ring 2 is set in the range of rotation speeds N1 to N2 in the region where the rotation torque changes from decrease to increase. As a result, even if the rotation speed changes during the measurement of the rotation torque Ta after press-fitting, it is possible to reduce the fluctuation of the rotation torque.

In the post-press-fit rotational torque measurement step (S05), the rotational torque is measured in a state where a 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 and 4 and the ball 7, between the hub ring 3 and the outer side seal member 10, and between the outer ring 2 and the ball 7 and the outer side seal member 10. The rotational torque is measured while the ball is running. In general, the dynamic friction coefficient is smaller than the static friction coefficient and the variation is small, so that the rotational torque can be measured with high accuracy.

The rotation speed N1, which is the lower limit of the rotation speed range, is preferably set to 2 rotations / min, which enables measurement of the rotation torque in a state where a dynamic friction force is generated. The rotation speed N2, which is the upper limit of the rotation speed range, is preferably set to 60 rotation speeds / 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 minimized. In the present embodiment, the rotation speed of the hub wheel 3 or the outer ring 2 is set to be in the range of 2 rotations / min to 60 rotations / min. This makes it possible to measure the rotational torque with high accuracy.

As described above, in the post-press-fit rotation torque measurement step (S05), the hub wheel 3 or the outer ring 2 is rotated in a small range of rotation speeds N1 to N2 in which the degree of fluctuation of the rotation torque with respect to the change in the rotation speed is small. As a result, even if the rotation speed of the hub wheel 3 or the outer ring 2 changes, the fluctuation of the rotation torque can be minimized, and the rotation torque can be measured with high accuracy.

Further, in the post-press-fit rotational torque measurement step (S05), the wheel bearing device is in a state where the outer side seal member 10 is fitted to the outer side opening end of the annular space formed by the outer ring 2 and the hub ring 3. The rotational torque of 1 is measured. Here, since the outer side sealing member 10 is located on the side opposite to the small diameter step portion 3a of the hub ring 3 to be crimped for fixing the inner ring 4, the crimping step (S06) described below In the above, even if an abnormality occurs in the inner raceway surface 4a or the like, the seal torque of the outer side seal member 10 is unlikely to be affected, and the rotational torque of the wheel bearing device 1 is also unlikely to change.

In the post-press-fit rotational torque measurement step (S05), the atmospheric temperature A around the wheel bearing device 1 is also measured. For example, the torque measuring device 13 may be provided with a temperature sensor 14 to measure the atmospheric temperature in the vicinity of the outer ring 2. In the preload inspection method of the present embodiment, since there is no step of rotating the wheel bearing device 1 at a high speed as in the case of use, the atmospheric temperature A is substantially constant in all the steps of the preload inspection method. Therefore, the measurement of the atmospheric temperature A may be performed in any of the steps from the temporary press-fitting step (S01) to the second bearing preload value calculation step (S08).

(Cramping process)
After the press-fitting, the rotational torque measuring step (S05) is followed by the crimping step (S06). In the crimping step (S06), a crimping process is performed in which the inner side end portion of the small diameter step portion 3a of the hub ring 3 is crimped to the inner side end surface 4b of the inner ring 4. The crimping process can be performed by, for example, a swing crimping process. After the crimping process, an axial negative gap is formed between the inner ring 4 and the hub ring 3.

(Rotation torque measurement process after crimping)
After the crimping step (S06), the post-crimping rotational torque measuring step (S07) is performed. In the post-crimping rotational torque measuring step (S07), as in the post-pressing rotational torque measuring step, the rotational torque is applied in a state where a dynamic frictional force is generated between the inner members 3 and 4 and the outer member 2. I'm measuring. In the post-crimping rotational torque measuring step (S07), the torque after crimping rotational torque Tb when the small diameter step portion 3a relatively rotates the hub ring 3 crimped to the inner ring 4 and the outer ring 2. It is measured by the measuring instrument 13. The post-crimping rotational torque Tb is a rotational torque measured after the crimping step (S06) and before the inner side seal member mounting step (S10). In the post-crimping rotational torque measuring step (S07), the outer ring 2 may be fixed and the hub wheel 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 (S05) after press fitting, when the hub wheel 3 is rotated, the variation in the rotational torque value measured when the rotational speed of the hub wheel 3 changes becomes smaller. preferable. Further, also in the post-crimping rotational torque measuring step (S07), as in the case of the press-fitting post-pressing rotational torque measuring step (S05), the rotational torque is measured instead of the starting torque of the bearing, and the hub wheel 3 or the outer ring 2 is operated at a low speed. By measuring the rotation torque Tb after crimping while rotating at a constant rotation speed at the rotation speeds N1 to N2, it is possible to measure the rotation torque with high accuracy.

In this case, for the rotation speed N1 and the rotation speed N2, the rotation speed N1 is set to 2 rotations / min and the rotation speed N2 is set to 60 rotations / min, as in the case of the rotation torque measurement step (S05) after press fitting. Is preferable. As a result, even if the rotation speed changes during the measurement of the rotational torque Tb after crimping, the fluctuation of the rotational torque Tb after crimping can be reduced, and the rotational torque can be stably measured. ..

Further, between the crimping step (S06) and the post-crimping rotational torque measuring step (S07), the same process as the familiar step (S04), that is, between the hub ring 3 and the outer ring 2 is filled. It is possible to carry out a familiarization step of applying the grease to the balls 7 of the inner side ball row 5 and the outer side ball row 6. As a result, the resistance generated between the grease and the ball 7 when the hub wheel 3 and the outer ring 2 are relatively rotated can be made constant, and is used for wheels in the post-crimping rotational torque measurement step (S07). When the rotational torque Tb after crimping of the bearing device 1 is measured, it is possible to further suppress the variation in the measured rotational torque Tb after crimping.

However, if the grease and the ball 7 are sufficiently familiar by carrying out the familiarization step (S04) and the resistance generated between the grease and the ball 7 is constant, the crimping step (S06) is performed. It is possible to omit the familiar step between the crimping and the rotational torque measuring step (S07).

(Second bearing preload calculation process)
After the crimping rotation torque measurement step (S07), the second bearing preload value calculation step (S08) is carried out. In the second bearing preload value calculation step (S08), the difference torque ΔT (Tb—Ta = ΔT) between the press-fitting rotational torque Ta and the crimped rotational torque Tb is calculated. Further, the preload change amount ΔP between after the press-fitting process and after the crimping process is obtained based on the differential torque ΔT. Further, the 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 crimping process performed in the crimping step (S06). Further, the preload change amount ΔP is a preload increased by the crimping process performed in the crimping step (S06). In order to obtain the preload change amount ΔP, as shown in FIG. 8, the relationship between the bearing preload of the wheel bearing device 1 and the rotational torque of the bearing is obtained in advance by experiments or the like according to a plurality of atmospheric temperatures. FIG. 8 shows the case where the broken line is the ambient temperature A1, the solid line is the ambient temperature A2 (A2> A1), and the alternate long and short dash line is the ambient temperature A3 (A3> A2). Then, the preload change amount ΔP selects a relationship corresponding to the atmospheric temperature A measured in the post-pressing rotational torque measurement step (S05) (in the present embodiment, the atmospheric temperature A2 is selected), and as shown in FIG. Calculated by applying the differential torque ΔT to the relationship.

The relationship between the bearing preload and the rotational torque of the bearing can be obtained for each specification of the wheel bearing device 1. Further, in FIG. 8, three atmospheric temperatures A1 to A3 are illustrated, but the present invention is not limited to this, and the relationship between the bearing preload and the rotational torque of the bearing at two or more atmospheric temperatures may be used, and the number thereof may be used. As the number increases, the accuracy improves.

The rotational torque Ta after press-fitting and the rotational torque Tb after crimping vary in measured values depending on the atmospheric temperature A at the time of measurement, even if the wheel bearing device 1 has the same axial positive clearance G0 or axial negative clearance G1. Occurs. This is because the viscosity of the grease filled between the hub ring 3 and the outer ring 2 changes, so that the thickness of the grease on the surface of the balls 7 of the inner ball row 5 and the outer ball row 6 changes, and the balls This is because the contact area of 7 changes. Therefore, as described above, it is possible to obtain a highly reliable preload change amount ΔP by obtaining the preload change amount ΔP from the differential torque ΔT using the relationship between the bearing preload and the bearing rotation torque according to the atmospheric temperature A. can.

(Judgment process)
A determination step (S09) is performed after the second bearing preload value calculation step (S08). In the determination step (S09), the suitability of the preload applied to the wheel bearing device 1 is determined depending on whether or not the second bearing preload value P2 is within a predetermined reference value range. In the determination step (S09), if the second bearing preload value P2 is within a predetermined reference value range, it is determined that the preload applied to the wheel bearing device 1 is appropriate, and the second bearing preload is determined to be appropriate. If the bearing preload value P2 is not within the range of the predetermined 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 (S08), the preload change amount ΔP due to the crimping was obtained by using the post-pressing rotational torque Ta and the post-crimping rotational torque Tb, which are the rotational torques before and after the crimping. Then, the second bearing preload value P2 is calculated.

In this way, when calculating the preload using the rotational torque before and after the crimping process, for example, when an abnormality such as the shape of the inner ring raceway surface collapses during the crimping process, the amount of increase in the rotational torque before and after the crimping process increases. Since it becomes large, the calculated second bearing preload value P2 is out of the range of the predetermined reference value. Therefore, by determining the calculated second bearing preload value P2 in the determination step (S09), it becomes possible to detect that an abnormality has occurred in the wheel bearing device 1 after the crimping process, and it is possible to detect that an abnormality has occurred in the wheel bearing device 1. It is possible to increase the reliability of the measured value of the preload applied to the bearing device 1. Further, since the second bearing preload value P2 is calculated from the highly reliable preload change amount ΔP in consideration of the ambient temperature A, the reliability of the measured value of the preload applied to the wheel bearing device 1 can be increased. .. As a result, it becomes possible to inspect the preload applied to the wheel bearing device 1 with higher reliability.

Further, the post-pressing rotational torque Ta and the post-crimping rotational torque Tb used 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 press-fitting rotational torque Ta and the crimping rotational torque Tb is for wheels such as the tightening allowance of the outer side sealing member 10 and the amount of grease filled between the hub wheel 3 and the outer ring 2. The variation of the bearing device 1 for each individual is not included, and only the amount of increase in the rotational torque due to the crimping process is extracted. As a result, the second bearing preload value P2 can be calculated accurately from the differential torque ΔT, and the suitability of the preload applied to the wheel bearing device 1 can be determined with high accuracy in the determination step (S09). Is possible.

Further, the reference value used when determining the suitability of the preload in the determination step (S09) is set in consideration of the variation in the rotational torque caused by the crimping process of crimping the small diameter step portion 3a to the inner ring 4. There is.

That is, between the post-pressing rotational torque Ta and the post-crimping rotational torque Tb, the position of the grease moves between the hub ring 3 and the outer ring 2 before and after the crimping process, and the hub of the outer side seal member 10 Variations due to changes in the degree of 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 the present embodiment, in consideration of these variations, the range of the reference value is set to a smaller range than in the case where the variations are not taken into consideration. As a result, the appropriateness of the preload applied to the wheel bearing device 1 can be determined with high accuracy in the determination step (S09), and it is possible to suppress the occurrence of erroneous determination.

(Inner side seal member mounting process)
After the determination step (S09), the inner side seal member mounting step (S10) is performed. By carrying out the inner side seal member mounting step (S10), the assembly step of the wheel bearing device 1 is completed. The inner side seal member mounting step (S10) may be performed before the determination step (S09) or after the second bearing preload value calculation step (S08) if it is after the crimping and rotational torque measurement step (S07). It is also possible to do it before. As shown in FIG. 10, in the inner ring member mounting step (S10), by fitting the inner side seal member 9 into the inner side opening 2a of the outer ring 2, the inner side end portion of the outer ring 2 and the inner ring 4 are fitted. The inner side seal member 9 is mounted between the inner side end portion and the inner side.

When the inner side seal member 9 is attached before the crimping step (S06), the inner ring 3 is slid between the outer ring 2 and the inner ring 4 depending on the degree of crimping of the hub ring 3 in the crimping step (S06). The dynamic resistance changes. Further, if the inner side seal member 9 is attached even after the crimping step (S06) but before the post-crimping rotational torque measurement step (S07), the inner side seal member 9 depends on the attached state of the inner side seal member 9. The sliding resistance between the outer ring 2 and the inner ring 4 of the above changes.

Therefore, if the inner side seal member 9 is mounted before the crimping step (S06) or the post-crimping rotational torque measuring step (S07), the post-crimping rotational torque measured in the post-crimping rotational torque measuring step (S07). It may affect the variation of Tb. Similarly, when the inner side sealing member 9 is mounted before the press-fitting post-rotation torque measuring step (S05), the press-fitting is measured in the post-press-fitting rotational torque measuring step (S05) depending on the mounting state of the inner side sealing member 9. It may affect the variation of the rear rotation torque Ta.

However, in the present embodiment, since the inner side seal member mounting step (S10) is performed after the post-crimping rotational torque measuring step (S07), the post-pressing rotational torque measuring step (S05) and the crimping are performed. In the rear rotation torque measuring step (S07), when the rotation torque Ta after press fitting and the rotation torque Tb after crimping of the wheel bearing device 1 are measured, the rotation torque may vary due to the influence of the inner side sealing member 9. It is possible to measure the rotational torque of the wheel bearing device 1 with high accuracy.

In the present embodiment, the inner side seal member mounting step (S10) is carried out after the crimping rotation torque measurement step (S07), but the cap member mounting step is carried out after the crimping rotation torque measurement step (S07). It can also be configured to carry out. In this case, in the cap member mounting step, the cap member is fitted into the inner side opening 2a of the outer ring 2 instead of the inner side sealing member 9, and the inner side opening 2a is closed by the cap member.

In the present embodiment, the atmospheric temperature A around the wheel bearing device 1 is measured in the post-press-fit rotational torque measurement step (S05), and the preload change amount ΔP is the atmosphere in the second bearing preload value calculation step (S08). It was calculated by selecting the relationship between the bearing preload and the bearing rotation torque according to the temperature A and applying the differential torque ΔT to this relationship, but instead of the atmospheric temperature A, the surface temperature B of the wheel bearing device 1 was used. You may use it. That is, the surface temperature B of the wheel bearing device 1 is measured in the post-press-fit rotational torque measurement step (S05), and the preload change amount ΔP corresponds to the surface temperature B in the second bearing preload value calculation step (S08). It may be calculated by selecting the relationship between the bearing preload and the rotational torque of the bearing and applying the differential torque ΔT to this relationship. It is considered that the surface temperature B and the atmospheric temperature A of the wheel bearing device 1 usually show substantially the same temperature. The place where the surface temperature B is measured may be, for example, the surface of the outer ring 2. As a means for measuring the surface temperature B, a contact type temperature sensor or a non-contact type temperature sensor can be used.

Although the wheel bearing device 1 for the driven wheel has been described in the present embodiment, this preload inspection method can also be applied to a wheel bearing device for a drive wheel having a specification for crimping a hub wheel. can.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, but is merely an example, and is further various as long as it does not deviate from the gist of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equal meaning described in the scope of claims, and all changes within the scope of the claims are made. include.

1 Bearing device for wheels 2 Outer ring 2c (inner side) outer raceway surface 2d (outer side) outer raceway surface 3 Hub wheel 3a Small diameter step 3c Inner raceway surface 4 Inner ring 4a Inner raceway surface 5 Inner side ball row 6 Outer side Ball row 7 Ball 9 Inner side seal member A Atmospheric temperature B Surface temperature G1 Axial negative clearance P1 First bearing preload value P2 Second bearing preload value S02 Press-fitting process S03 First bearing preload value calculation process S04 Familiar process S05 Rotational torque measurement process after press-fitting S06 Crunching process S07 Rotational torque measurement process after crimping S08 Second bearing preload value calculation process S09 Judgment process Ta Rotational torque after press-fitting Tb Rotational torque after crimping ΔT Difference torque ΔP Preload change amount

Claims (3)

An outer member having multiple rows of outer raceways on the inner circumference,
The inner ring is composed of a hub ring having a small diameter step portion extending in the axial direction on the outer periphery and an inner ring press-fitted into the small diameter step portion of the hub ring, and has an inner raceway surface of the double row facing the outer raceway surface of the double row. With square members,
A double-row rolling element rotatably accommodated between both raceways of the outer member and the inner member, and
It is a preload inspection method for wheel bearing devices equipped with
A press-fitting step of press-fitting the inner ring into the small-diameter step portion of the hub ring to a position where the inner ring abuts on the hub ring in the axial direction.
A first bearing preload value calculation step for calculating a first bearing preload value of the wheel bearing device based on an axial negative gap between both raceway surfaces and the rolling element after the press-fitting step.
A post-press-fit rotational torque measuring step for 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 press-fitting and rotational torque measurement step, a crimping step of crimping the inner end of the small diameter step portion to the inner ring,
A post-crimping rotational torque measuring step for measuring the post-crimping rotational torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the crimping step.
The amount of change in preload between after the press-fitting process and after the crimping process, which is obtained based on the difference torque between the post-pressing rotational torque and the post-crimping rotational torque, is added to the first bearing preload value. The second bearing preload calculation process for calculating the second bearing preload value, and the second bearing preload calculation process.
A determination step of determining the suitability of the preload applied to the wheel bearing device depending on whether or not the second bearing preload value is within the range of the reference value is provided.
In the second bearing preload value calculation step, a preload inspection method for a wheel bearing device is characterized in that the preload change amount is obtained from the differential torque using the relationship between the rotational torque and the preload according to the atmospheric temperature. .. An outer member having multiple rows of outer raceways on the inner circumference,
The inner ring is composed of a hub ring having a small diameter step portion extending in the axial direction on the outer periphery and an inner ring press-fitted into the small diameter step portion of the hub ring, and has an inner raceway surface of the double row facing the outer raceway surface of the double row. With square members,
A double-row rolling element rotatably accommodated between both raceways of the outer member and the inner member, and
It is a preload inspection method for wheel bearing devices equipped with
A press-fitting step of press-fitting the inner ring into the small-diameter step portion of the hub ring to a position where the inner ring abuts on the hub ring in the axial direction.
A first bearing preload value calculation step for calculating a first bearing preload value of the wheel bearing device based on an axial negative gap between both raceway surfaces and the rolling element after the press-fitting step.
A post-press-fit rotational torque measuring step for 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 press-fitting and rotational torque measurement step, a crimping step of crimping the inner end of the small diameter step portion to the inner ring,
A post-crimping rotational torque measuring step for measuring the post-crimping rotational torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the crimping step.
The amount of change in preload between after the press-fitting step and after the crimping step, which is obtained based on the difference torque between the post-pressing rotational torque and the post-crimping rotational torque, is added to the first bearing preload value. The second bearing preload calculation process for calculating the second bearing preload value, and the second bearing preload calculation process.
A determination step of determining the suitability of the preload applied to the wheel bearing device depending on whether or not the second bearing preload value is within the range of the reference value is provided.
In the second bearing preload calculation step, the amount of change in preload is obtained from the difference torque by using the relationship between the rotational torque and the preload according to the surface temperature of the wheel bearing device. Preload inspection method for bearing equipment. The preload inspection method for a wheel bearing device according to claim 2, wherein the surface temperature of the wheel bearing device is measured by a contact type temperature sensor or a non-contact type temperature sensor.

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