JP2022039482A - Preload inspection method of wheel bearing device - Google Patents

Abstract

To provide a preload inspection method of a wheel bearing device which can further enhance reliability when determining the adaptability of a preload.SOLUTION: A preload inspection method comprises: a process S02 of pressure-inserting an inner ring 4 into a small-diameter step part 3a; a process S03 of calculating a first bearing preload value P1 on the basis of a negative clearance G1 in an axial direction; a process S05 of measuring post pressure-insertion rotation torque Ta; a process S06 of forming a caulking part 3h by caulking the small-diameter step part to the inner ring; a caulking processing degree measurement process S07 of measuring a height dimension h and an outside-diameter dimension r of the caulking part; a process S08 of measuring post-caulking rotation torque Tb; a process S09 of calculating a second bearing preload value P2 by adding a preload change amount ΔP based on differential torque ΔT to the first bearing preload value; a first determination process S10 of determining the adaptability of the preload by a determination whether or not the second bearing preload value is within a reference value; and a second determination process S11 of determining the presence or absence of a caulking abnormality by collating the height dimension, the outside-diameter dimension and a value of the differential torque.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.

When the preload applied to the bearing is obtained from the preload gap, for example, in a wheel bearing device having specifications in which the hub wheel is crimped to the inner ring to form an inner member, the amount of pushing of the inner ring when the hub wheel is crimped is determined. It is possible to obtain the preload applied to the bearing device by converting it into the preload gap reduction amount and combining the preload gap reduction amount and the preload gap before the crimping process.

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 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 the crimping process.

Japanese Unexamined Patent Publication No. 10-185717

As described above, when the preload gap reduction amount is obtained in a bearing device configured to crimp the hub wheel to the inner ring, the accuracy of the preload gap reduction amount obtained is that an abnormality such as a shape collapse of the inner ring raceway surface occurs during the crimping process. Although there is a risk of deterioration, it is difficult to detect abnormalities such as deformation of the inner ring raceway surface.

On the other hand, when the preload is calculated using the rotational torque before and after the crimping process, the amount of increase in the rotational torque before and after the crimping process becomes large when an abnormality such as the shape of the inner ring raceway surface is deformed during the crimping process. It is possible to detect that an abnormality such as a shape collapse of the inner ring raceway surface has occurred, and it is possible to increase the reliability when determining the suitability of the measured preload.

However, when the preload is calculated using the rotational torque before and after the crimping process, the suitability of the preload is determined by whether or not it is within the preset pressurization reference value, and the degree of abnormality is large. Since it can only be detected, there is room for further increasing the reliability when determining the suitability of preload.

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 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 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. 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-pressurization rotational torque measurement step for measuring the post-pressurization rotational torque of the wheel bearing device when the inner member and the outer member are relatively rotated after the press-fitting step, and a post-pressurization rotational torque measurement step. After the press-fitting rotational torque measurement step, a crimping step of crimping the inner end of the small-diameter step portion to the inner ring to form a crimping portion in the small-diameter step portion, and a crimping step formed in the crimping step. The wheel bearing device when the inner member and the outer member are relatively rotated after the crimping process and the crimping process for measuring the crimping degree of the crimping portion. After the press-fitting step and after the crimping step, which are obtained based on the difference torque between the post-pressing rotational torque and the post-crimping rotational torque, and the post-crimping rotational torque measuring step for measuring 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 above to the first bearing preload value, and the second bearing preload value is the preload reference value. The first determination step of determining the suitability of the preload applied to the wheel bearing device depending on whether or not it is within the range is collated with the crimping degree and the value of the differential torque, and the addition is performed. A preload inspection method for a wheel bearing device comprising a second determination step of determining the presence or absence of a crimping abnormality depending on whether or not the value of the differential torque with respect to the degree of tightening is within the range of the torque reference value. be.

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

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 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 portion of a hub wheel is crimped. It is a side sectional view which shows the bearing device for a wheel in the state which the height dimension and the outer diameter dimension of a crimping portion are measured by a contact type measuring instrument. It is a side sectional view which shows the bearing device for a wheel in the state which the height dimension of a crimping portion is measured by a non-contact type measuring instrument. It is a figure which shows the relationship between a bearing preload and a rotational torque. (A) is a diagram showing the relationship between the height dimension of the crimping portion and the differential torque, and (b) is a diagram showing the relationship between the outer diameter dimension of the crimping portion and the differential 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 the first 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 wheel 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). , Crying step (S06), crimping degree measurement step (S07), post-crimping rotation torque measuring step (S08), second bearing preload value calculation step (S09), first determination step (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 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 side 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 The axial negative gap 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 gap G1 in the wheel bearing device 1 and the bearing preload value is obtained in advance by an experiment or the like, and this relationship is obtained in the axial direction in the press-fitting step (S02). Calculated by fitting the negative gap G1. The relationship between the negative clearance in the axial direction 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 (S08), 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 rotation torque measurement step (S05) after press-fitting is carried out. In the press-fitting post-rotation torque measurement 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 revolution 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 rotation 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 starts to increase. 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, a dynamic frictional force is applied between the inner members 3 and 4 and the rolling element 7, between the hub ring 3 and the outer side sealing member 10, and between the outer ring 2 and the rolling element 7 and the outer side sealing member 10. The rotational torque is measured while the above is occurring. 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 10 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 10 rotations / min to 30 rotations / min to 30 in which the fluctuation of the rotation torque with respect to the change of the rotation speed is the smallest in the range of 10 rotations / min to 60 rotations / min. The rotation speed is set to rotation / 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 Even if an abnormality occurs in the inner ring 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.

(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. By performing the crimping process, the crimping portion 3h is formed at the inner side end portion of the small diameter step portion 3a.

As shown in FIG. 7, the crimping process can be performed by a rocking crimping process using a crimping tool such as a crimping punch 14. In the crimping process by the swing crimping process, for example, the crimping punch 14 arranged above the small diameter step portion 3a in the hub ring 3 is lowered to bring it into contact with the inner side end portion of the small diameter step portion 3a to have a small diameter. This is done by swinging the crimping punch 14 in contact with the step portion 3a. After the crimping process, an axial negative gap is formed between the inner ring 4 and the hub ring 3.

(Crimping process degree measurement process)
After the crimping step (S06), the crimping processability measuring step (S07) is carried out. In the crimping work degree measuring step (S07), the crimping work degree of the crimping portion 3h formed by the crimping work is measured.

Here, the degree of crimping is the degree of deformation of the crimping portion 3h that has been plastically deformed by the crimping, and can be represented by the shape of the crimping portion 3h. The shape of the crimping portion 3h to be measured includes a height dimension h in the axial direction of the crimping portion 3h, an outer diameter dimension r in a direction orthogonal to the axial direction of the crimping portion 3h, and the like. That is, the crimping degree includes the height dimension h in the axial direction of the crimping portion 3h and the outer diameter dimension r in the direction orthogonal to the axial direction of the crimping portion 3h.

In the present embodiment, the degree of crimping work of the crimping portion 3h is measured by measuring the height dimension h and the outer diameter dimension r. However, the degree of crimping work of the crimping portion 3h can be measured by measuring only one of the height dimension h and the outer diameter dimension r.

As shown in FIG. 8, the height dimension h and the outer diameter dimension r, which are the crimping degree of the crimping portion 3h, can be measured by using, for example, a measuring instrument 15. The measuring instrument 15 is a contact-type measuring instrument in which a contactor is brought into contact with the crimping portion 3h to perform measurement, and has a main body portion 151, a first contactor 152, and a second contactor 153.

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

The first contact 152 is a long member extending along the axial direction, and is provided in a pair on the main body portion 151. The first contact 152 contacts the inner end surface 4b of the inner ring 4 and the outer diameter edge portion in the direction orthogonal to the axial direction of the crimping portion 3h when measuring the height dimension h and the outer diameter dimension r. ..

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

When measuring the height dimension h of the crimping 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 crimping portion 3h. After that, by measuring the axial length from the tip of the first contact 152 to the second contact 153, the inner side of the crimping portion 3h becomes the height dimension h of the crimping portion 3h. Measure the axial dimension to the side end face

Further, when measuring the outer diameter dimension r of the crimping portion 3h using the measuring instrument 15, the first contact piece 152 is moved in a direction orthogonal to the axial direction with respect to the main body portion 151, and the first contact is made. The child 152 is brought into contact with the outer diameter edge portion of the crimping portion 3h. After that, the outer diameter dimension r of the crimping portion 3h is measured by measuring the length between the first contactor 152 and the first contactor 152 in the direction orthogonal to the axial direction.

In the present embodiment, the crimping degree of the crimping portion 3h is measured by using the measuring instrument 15 having the main body portion 151, the first contactor 152, and the second contactor 153. The degree of crimping of the crimping portion 3h can be measured by a contact-type measuring instrument having another configuration without limitation. As described above, when the degree of crimping is measured by using the contact type measuring instrument, it is easy to make the measuring instrument a simple structure.

Further, the degree of crimping work of the crimping portion 3h can be measured by using a non-contact type measuring instrument that performs the measurement without contacting the crimping portion 3h. As the non-contact type measuring instrument, for example, as shown in FIG. 9, a laser displacement meter that measures the height dimension h of the crimping portion 3h by irradiating the crimping portion 3h with a laser can be used. Further, it is also possible to measure the height dimension h, the outer diameter dimension r, and the like of the crimping portion 3h by imaging the crimping portion 3h and processing the image of the captured crimping portion 3h. In this way, when the degree of crimping is measured using a non-contact type measuring instrument, the measurement can be performed without contacting the crimping portion 3h, so that the wheel bearing device 1 is assembled. It becomes easy to measure the degree of crimping on the production line.

(Rotation torque measurement process after crimping)
After the crimping degree measurement step (S07), the post-crimping rotational torque measuring step (S08) is performed. In the post-crimping rotational torque measuring step (S08), as in the post-pressing rotational torque measuring step, the rotational torque is applied in a state where a dynamic friction 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 (S08), 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 (S12). In the post-crimping rotational torque measuring step (S08), 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 (S08), 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 slowed down. 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 10 rotations / min and the rotation speed N2 is set to 60 rotations / min, as in the case of the post-press-fit rotation torque measurement step (S05). Is preferable. In the present embodiment, the rotation speed of the hub wheel 3 or the outer ring 2 is 10 rotations / min to 30 rotations / min to 30 in which the fluctuation of the rotation torque with respect to the change of the rotation speed is the smallest in the range of 10 rotations / min to 60 rotations / min. The rotation speed is set to rotation / min. 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. ..

In the present embodiment, the post-crimping rotational torque measurement step (S08) is performed after the crimping degree measurement step (S07), but the crimping is performed after the post-crimping rotational torque measuring step (S08). It is also possible to carry out the workability measuring step (S07).

Further, between the crimping step (S06) and the post-crimping rotational torque measuring step (S08), 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 in which the grease is applied to the balls 7 of the inner ball row 5 and the outer 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 (S08). 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 (S08).

(Second bearing preload calculation process)
After the crimping rotation torque measurement step (S08), the second bearing preload value calculation step (S09) is carried out. In the second bearing preload value calculation step (S09), 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). As shown in FIG. 10, the preload change amount ΔP is calculated by obtaining the relationship between the bearing preload of the wheel bearing device 1 and the rotational torque of the bearing in advance by experiments or the like and applying the differential torque ΔT to this relationship. do. 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.

(First determination step)
After the second bearing preload value calculation step (S09), the first determination step (S10) is carried out. In the first determination step (S10), 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 the range of the preload reference value. In the first determination step (S10), if the second bearing preload value P2 is within the range of the preload reference value, it is determined that the preload applied to the wheel bearing device 1 is appropriate, and the first step is made. If the bearing preload value P2 of 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 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. Therefore, the calculated second bearing preload value P2 is out of 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 a shape deformation of the inner ring raceway surface occurs in the wheel bearing device 1 after the crimping process. It becomes possible to detect that, and it is possible to increase the reliability of the measured value of the preload applied to the wheel bearing device 1. This makes it 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 the wheel such as the lip 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 first determination step (S10). It is possible to judge.

Further, the reference value used when determining the suitability of the preload in the first determination step (S10) takes into consideration the variation in the rotational torque caused by the crimping process of crimping the small diameter step portion 3a to the inner ring 4. It is set.

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 preload 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 first determination step (S10), and it is possible to suppress the occurrence of erroneous determination. ..

(Second determination step)
After the first determination step (S10), the second determination step (S11) is carried out. In the second determination step (S11), the crimping work degree of the crimping portion 3h and the value of the differential torque ΔT are collated, and the value of the differential torque ΔT with respect to the crimping work degree of the crimping portion 3h is the torque reference value. Whether or not there is a crimping abnormality is determined based on whether or not it is within the range of.

Specifically, as shown in FIG. 11A, the first relational line X1 representing the relationship between the height dimension h of the crimping portion 3h and the differential torque ΔT is obtained in advance by an experiment or the like, and the height dimension h. The range between the upper limit value X1U and the lower limit value X1L of the value of the differential torque ΔT with respect to the above is set in advance as the range R1 of the first torque reference value when determining the presence or absence of a crimping abnormality. Further, as shown in FIG. 11B, the second relational line X2 showing the relationship between the outer diameter dimension r of the crimping portion 3h and the differential torque ΔT is obtained in advance by experiments or the like, and the differential torque with respect to the outer diameter dimension r is obtained. 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 a crimping abnormality.

Then, the height dimension h and the outer diameter dimension r of the crimping portion 3h are collated with the value of the differential torque ΔT, and the value of the differential torque ΔT with respect to the height dimension h falls within the range R1 of the first torque reference value. Whether or not the difference torque ΔT with respect to the outer diameter dimension r is within the range R2 of the second torque reference value determines whether or not there is a crimping abnormality.

In this case, for example, when the height dimension h and the outer diameter dimension r are collated with the value of the difference torque ΔT, the value of the difference torque ΔT with respect to the height dimension h is within the range R1 of the first torque reference value. When 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 crimping abnormality has occurred. Further, when the height dimension h and the outer diameter dimension r are collated with the value of the differential torque ΔT, is the value of the differential torque ΔT with respect to the height dimension h at least within the range R1 of the first torque reference value? Or, if 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 crimping abnormality has occurred.

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

Further, in this preload inspection method, the height dimension h and the outer diameter dimension r are used as the degree of crimping 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 crimping without lowering the production efficiency in the mass production line.

Further, in the second determination step (S11), the determination result of the appropriateness of the preload in the first determination step (S10) and the determination result of the presence or absence of the crimping abnormality in the second determination step (S11) are used. Based on this, it is determined whether or not the wheel bearing device 1 after the crimping process 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 it is determined in the second determination step (S11) that a crimping abnormality has not occurred, the addition is applied. It is determined that the wheel bearing device 1 after tightening is a good product. Further, when it is determined that the preload of the wheel bearing device 1 is not appropriate at least in the first determination step (S10), or it is determined that a crimping abnormality has occurred in the second determination step (S11). It is determined that the wheel bearing device 1 after the crimping process is not a good product.

In this way, by carrying out the second determination step (S11) in addition to the first determination step (S10), the determination of the suitability of the preload in the first determination step (S10) can be determined by the second determination step. It can be supplemented by the determination of the presence or absence of the crimping abnormality in (S11). This makes it 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.

Further, by measuring the crimping degree such as the height dimension h and the outer diameter dimension r in the preload inspection method, the shape of the crimping portion 3h can be grasped, and the grasped shape of the crimping portion 3h can be obtained. The crimping condition can be set based on this, and the crimping portion 3h can be adjusted to an appropriate shape. As a result, the shape of the crimping portion 3h can be leveled at a plurality of manufacturing bases, manufacturing lots, and the like, and it becomes possible to manufacture a wheel bearing device 1 of uniform quality.

In this embodiment, both the height dimension h and the outer diameter dimension r are measured as the measurement of the degree of crimping, but only one of the height dimension h and the outer diameter dimension r is crimped. It is also possible to measure it as 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 suitability of the preload applied to the wheel bearing device 1 is further improved, and the quality is higher. It is possible to manufacture a wheel bearing device 1.

However, it is more accurate to determine the presence or absence of a crimping abnormality 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 the suitability of preload.

Further, in the present embodiment, after the appropriateness of the preload is determined in the first determination step (S10), the presence or absence of the crimping abnormality is determined in the second determination step (S11). It is also possible to determine the appropriateness of the preload in the second determination step (S11) after determining the presence or absence of the crimping abnormality in the determination step (S10) of 1.

(Inner side seal member mounting process)
After the second determination step (S11), the inner side seal member mounting step (S12) is carried out. By carrying out the inner side seal member mounting step (S12), the assembly step of the wheel bearing device 1 is completed. The inner side seal member mounting step (S12) is before the second determination step (S11) and before the first determination step (S10) if it is after the crimping and rotational torque measurement step (S08). , Or it can be carried out before the second bearing preload value calculation step (S09). As shown in FIG. 12, in the inner ring member mounting step (S12), 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 (S08), 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 (S08), the post-crimping rotational torque measured in the post-crimping rotational torque measuring step (S08). 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 (S12) is performed after the post-crimping rotational torque measuring step (S08), the post-pressing rotational torque measuring step (S05) and the crimping are performed. In the rear rotation torque measuring step (S08), 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 does not 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 (S12) is carried out after the crimping rotation torque measurement step (S08), but the cap member mounting step is carried out after the crimping rotation torque measurement step (S08). 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.

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 15 (contact type) measuring instrument 16 (non-contact type) measuring instrument h (tightening part) height dimension r (tightening part) outer diameter dimension G1 Axial negative Gap P1 First bearing preload value P2 Second bearing preload value R1 First torque reference value range R2 Second torque reference value range S02 Press-fitting process S03 First bearing preload value calculation process S05 Rotational torque measurement process after press-fitting S06 Crunching process S07 Cramping degree measurement step S08 Rotational torque measurement step after crimping S09 Second bearing preload value calculation step S10 First judgment step S11 Second judgment step Ta Rotation torque after press-fitting Tb Rotation after crimping Torque ΔT Differential torque ΔP Preload change amount

Claims (4)

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 rotation torque measurement step, a crimping step of crimping the inner end of the small diameter step portion to the inner ring to form a crimping portion on the small diameter step portion.
A crimping work degree measuring step for measuring the crimping work degree of the crimping portion formed in the crimping step, and a crimping work degree measuring step.
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.
The first 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 preload reference value.
The crimping degree and the differential torque value are collated, and the presence or absence of a crimping abnormality is determined based on whether or not the differential torque value with respect to the crimping degree is within the range of the torque reference value. A method for preload inspection of a wheel bearing device, which comprises a second determination step. The wheel bearing according to claim 1, wherein the degree of crimping includes at least one of a height dimension in the axial direction of the crimping portion and an outer diameter dimension in a direction orthogonal to the axial direction of the crimping portion. Preload inspection method for the device. In the crimping degree measurement step,
The preload inspection method for a wheel bearing device according to claim 1 or 2, wherein the degree of crimping is measured by a contact-type measuring instrument that measures the crimping portion by bringing a contactor into contact with the crimping portion. In the crimping degree measurement step,
The preload inspection method for a wheel bearing device according to claim 1 or 2, wherein the degree of crimping is measured by a non-contact type measuring instrument that measures without contacting the crimping portion.

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