Preload inspection method for wheel bearing device

Abstract

The preload inspection method for wheel bearing assembly includes: a pressing process (S02), in which the inner ring (4) is pressed into the small diameter step portion (3a); a first bearing preload value calculation process (S03), in which the first bearing preload value (P1) is calculated based on the axial negative clearance (G1) between the track surface and the rolling element after the pressing process (S02); a pressing-after-pressurization rotational torque measurement process (S05), in which the pressing-after-pressurization rotational torque (Ta) is measured after the pressing process; and a riveting process (S06), in which the small diameter step portion is riveted to the inner ring after the pressing-after-pressurization rotational torque measurement process. The process includes: a riveting torque measurement step (S07), which measures the riveting torque (Tb) after the riveting process; a second bearing preload calculation step (S08), which calculates the second bearing preload value (P2) by adding the preload change (ΔP) based on the difference torque (ΔT) between the pressed-in rotational torque (Ta) and the riveting rotational torque (Tb) to the first bearing preload value (P1); and a judgment step (S09), which determines whether the preload is appropriate based on whether the second bearing preload value (P2) is within the range of the reference value.

Description

Technical Field

[0001] This invention relates to a method for checking the preload of wheel bearing devices. Background Technology

[0002] Previously, wheel bearing devices were known in the suspension systems of motor vehicles and the like that support wheels for free rotation. In such wheel bearing devices, preload is applied between the rolling elements constituting the bearing device and the raceway.

[0003] Applying preload to the bearing assembly can improve its rigidity while suppressing vibration and noise. However, excessive preload can lead to increased rotational torque and reduced lifespan, so it is important to ensure that the bearing assembly is given an appropriate preload.

[0004] As a method for confirming the preload applied to the bearing assembly, such as that disclosed in Patent Document 1, a preload measurement method is known in which the preload applied to the bearing is determined by measuring the axial preload clearance in a rolling bearing in which rolling elements are arranged in a double row.

[0005] When the preload applied to the bearing is determined based on the preload clearance, for example in a wheel bearing assembly where the hub ring is riveted to the inner ring to form the inner component, the amount of the inner ring being pushed in during riveting can be converted into the amount of preload clearance reduction, and the amount of preload clearance reduction can be added to the preload clearance before riveting to determine the preload applied to the bearing assembly.

[0006] In addition, in a bearing assembly with a structure in which the hub ring is riveted to the inner ring, the rotational torque of the bearing assembly before and after riveting is measured. The increase in preload is calculated based on the increase in rotational torque before and after riveting. The increase in preload is then added to the preload of the bearing assembly before riveting to calculate the preload applied to the bearing assembly.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 10-185717 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, in bearing assemblies where the hub ring is riveted to the inner ring, if abnormalities such as shape distortion of the inner ring track surface occur during the riveting process, it is difficult to accurately determine the reduction in preload clearance based on the amount of inner ring insertion, which may reduce the reliability of the measured value of the preload applied to the bearing assembly.

[0012] Furthermore, regarding the rotational torque of the bearing assembly, the measured value will deviate even among bearing assemblies with the same preload clearance, depending on the temperature of the bearing assembly at the time of measurement. As a result, the reliability of the calculated preload may be reduced.

[0013] Furthermore, immediately after riveting, the wheel hub undergoes plastic deformation, causing the temperature near the inner ring to rise and the inner ring to expand. Consequently, the measured rotational torque is higher compared to measurements taken when the inner ring is not expanded, which may affect the accuracy of the preload measurement.

[0014] Furthermore, when the preload is calculated using the rotational torque before and after riveting, the determination of whether the preload is appropriate is based on whether it is within the range of the preload reference value. This method can only detect abnormalities of a greater degree. Therefore, there is room to further improve the reliability of the determination of whether the preload is appropriate.

[0015] Therefore, this invention provides a preload inspection method for a wheel bearing assembly capable of checking the preload applied to the wheel bearing assembly with higher reliability. Furthermore, this invention provides a preload inspection method for a wheel bearing assembly capable of checking the preload applied to the wheel bearing assembly with higher reliability by taking into account changes in rotational torque caused by temperature. Additionally, an object of this invention is to provide a preload inspection method for a wheel bearing assembly capable of suppressing the effects of temperature rise caused by riveting processes, thereby determining the quality of the preload applied to the wheel bearing assembly with higher accuracy. Furthermore, this invention provides a preload inspection method for a wheel bearing assembly capable of further improving the reliability of determining whether the preload applied to the wheel bearing assembly is appropriate.

[0016] Solution for solving the problem

[0017] That is, the first invention is a method for checking the preload of a wheel bearing assembly, wherein the wheel bearing assembly comprises: an outer member having two rows of outer track surfaces on its inner circumference; an inner member including a hub ring having a small-diameter stepped portion extending axially on its outer circumference, and an inner ring pressed into the small-diameter stepped portion of the hub ring, and having two rows of inner track surfaces facing the two rows of outer track surfaces; and two rows of rolling elements received between the two track surfaces of the outer member and the inner member in a rolling manner. The method for checking the preload of the wheel bearing assembly is characterized in that the method comprises: a pressing step, in which the inner ring is pressed axially relative to the small-diameter stepped portion of the hub ring until the inner ring abuts against the hub ring; and a first bearing preload value calculation step, in which the first bearing preload value of the wheel bearing assembly is calculated based on the axial negative clearance between the two track surfaces and the rolling elements after the pressing step. The process includes: bearing preload value; a pressing-in rotational torque measurement step, which measures the pressing-in rotational torque of the wheel bearing assembly when the inner component and the outer component rotate relative to each other after the pressing-in step; a riveting step, which rivets the inner end of the small-diameter stepped portion to the inner ring after the pressing-in rotational torque measurement step; a riveting rotational torque measurement step, which measures the riveting rotational torque of the wheel bearing assembly when the inner component and the outer component rotate relative to each other after the riveting step; a second bearing preload value calculation step, which adds the preload change between the pressing-in step and the riveting step, calculated based on the difference torque between the pressing-in rotational torque and the riveting rotational torque, to the first bearing preload value to calculate the second bearing preload value; and a judgment step, which determines whether the preload applied to the wheel bearing assembly is appropriate based on whether the second bearing preload value is within the range of the reference value.

[0018] In the second invention, based on the first invention, in the process of calculating the preload value of the second bearing, the relationship between the rotational torque corresponding to the ambient temperature and the preload is used, and the change in preload is calculated based on the difference torque.

[0019] In the third invention, based on the first invention, in the process of calculating the second bearing preload value, the relationship between the rotational torque corresponding to the surface temperature of the wheel bearing device and the preload is used, and the change in preload is calculated based on the difference torque.

[0020] In the fourth invention, based on the first invention, the preload inspection method for the wheel bearing device includes a rotational torque correction step between the post-riveting rotational torque measurement step and the second bearing preload value calculation step. In the rotational torque correction step, the post-riveting rotational torque is corrected based on the temperature rise of the inner ring caused by the riveting process, and the corrected post-riveting rotational torque is calculated. In the second bearing preload value calculation step, the preload change between the pressing process and the riveting process is calculated based on the difference between the pressing rotational torque and the corrected post-riveting rotational torque. The preload change is added to the first bearing preload value to calculate the second bearing preload value.

[0021] According to the fifth invention, based on the first invention, the preload inspection method for the wheel bearing device includes: a temperature measurement step, which measures the temperature of the riveted portion between the wheel hub and the inner ring after the riveting process is completed; and a rotational torque correction step, which corrects the rotational torque after riveting based on the temperature of the riveted portion measured in the temperature measurement step, and calculates the corrected rotational torque after riveting. In the second bearing preload value calculation step, the preload change between the pressing process and the riveting process is calculated based on the difference between the pressing rotational torque and the corrected rotational torque after riveting, and the preload change is added to the first bearing preload value to calculate the second bearing preload value.

[0022] According to the sixth invention, based on the first invention, the preload inspection method for the wheel bearing device includes a riveting workability measurement step for measuring the riveting workability of the riveting portion formed in the small-diameter step portion during the riveting process. The determination step includes: a first determination step for determining whether the preload applied to the wheel bearing device is appropriate based on whether the second bearing preload value is within the range of a reference value; and a second determination step for comparing the riveting workability with the value of the differential torque, and determining whether there is a riveting abnormality based on whether the value of the differential torque relative to the riveting workability is within the range of a torque reference value.

[0023] The seventh invention is a method for checking the preload of a wheel bearing assembly, wherein the wheel bearing assembly comprises: an outer member having two rows of outer track surfaces on its inner circumference; an inner member including a hub ring having a small-diameter stepped portion extending axially on its outer circumference, and an inner ring pressed into the small-diameter stepped portion of the hub ring, and having two rows of inner track surfaces facing the two rows of outer track surfaces; and two rows of rolling elements received between the two track surfaces of the outer member and the inner member in a rolling manner, characterized in that the method for checking the preload of the wheel bearing assembly comprises: a pressing step, wherein the inner ring is pressed axially into the hub ring relative to the small-diameter stepped portion of the hub ring until the inner ring and the inner track surface are aligned. The process includes: the position of the wheel hub abutment; a first inner ring height measurement process, measuring the height of the first inner ring from the outer end of the wheel hub to the inner end of the inner ring after the pressing process; a first bearing preload calculation process, measuring the axial negative clearance between the two track surfaces and the rolling element after the pressing process, and calculating the bearing preload of the wheel bearing assembly based on the axial negative clearance; a pressing-back rotational torque measurement process, measuring the pressing-back rotational torque of the wheel bearing assembly when the inner component and the outer component rotate relative to each other after the pressing process; and a riveting process, after the first inner ring height measurement process and the pressing-back rotational torque measurement process, riveting the inner side of the small diameter step portion. The end is riveted to the inner ring; a post-riveting temperature measurement process measures the temperature of the small-diameter stepped portion and the riveted portion of the inner ring after the riveting process; a second inner ring height measurement process measures the height of the second inner ring from the outer end of the hub ring to the inner end of the inner ring after the riveting process; an inner ring push-in estimation process calculates the push-in amount of the inner ring based on the difference between the first inner ring height and the second inner ring height, and corrects the push-in amount of the inner ring based on the temperature of the riveted portion, thereby estimating the corrected push-in amount of the inner ring relative to the hub ring; a final clearance calculation process calculates the clearance between the two track surfaces and the rolling element based on the estimated corrected push-in amount of the inner ring. The following steps are involved: 1) A clearance reduction step, which calculates the final clearance between the inner ring and the hub ring based on the clearance reduction and the axial negative clearance; 2) A second bearing preload calculation step, which calculates the second bearing preload value of the wheel bearing assembly based on the calculated final clearance; 3) A post-riveting rotational torque measurement step, which measures the post-riveting rotational torque of the wheel bearing assembly when the inner component and the outer component rotate relative to each other after the riveting process; 4) A post-riveting rotational torque correction step, which estimates the torque increase caused by temperature change in the post-riveting rotational torque based on the temperature of the riveted portion after the riveting process, and subtracts the torque increase from the post-riveting rotational torque to correct the post-riveting rotational torque.The process includes: a preload change estimation step, which calculates the difference between the rotational torque after pressing and the corrected rotational torque after riveting, and estimates the preload change caused by the riveting process based on this difference; a third bearing preload value calculation step, which adds the preload change to the first bearing preload value to calculate the third bearing preload value; and a judgment step, which determines whether the preload applied to the wheel bearing assembly is appropriate based on whether the second bearing preload value and the third bearing preload value are within a specified threshold, and whether the relative difference between the second bearing preload value and the third bearing preload value is within a specified threshold.

[0024] Invention Effects

[0025] As a result of the present invention, the following effects are achieved.

[0026] According to the first invention, the preload applied to the bearing assembly for wheels can be checked with greater reliability.

[0027] According to the second invention, the variation of rotational torque caused by ambient temperature is taken into account, and according to the third invention, the variation of rotational torque caused by the surface temperature of the wheel bearing assembly is taken into account, thus enabling the preload applied to the wheel bearing assembly to be checked with higher reliability.

[0028] According to the fourth invention, the effect of temperature rise in the inner ring caused by riveting can be suppressed, thereby allowing for more accurate determination of the quality of preload applied to the wheel bearing assembly.

[0029] According to the fifth invention, the effect of the temperature rise of the inner ring caused by the riveting process is taken into account, thereby enabling a more accurate determination of the quality of the preload applied to the bearing device for the wheel.

[0030] According to the sixth invention, the reliability of determining whether the preload applied to the wheel bearing device is appropriate can be further improved.

[0031] According to the seventh invention, the preload applied to the bearing assembly for wheels can be checked with higher reliability. Attached Figure Description

[0032] Figure 1 This is a side sectional view showing a wheel bearing assembly implementing a preload inspection method.

[0033] Figure 2 This is a flowchart illustrating the pre-pressure inspection method of the first embodiment.

[0034] Figure 3 This is a side sectional view of a wheel bearing assembly in the state where the inner ring is temporarily pressed into the small-diameter stepped portion of the wheel hub ring.

[0035] Figure 4 This is a side sectional view of a wheel bearing assembly showing the inner ring pressed into the small-diameter stepped portion of the wheel hub ring.

[0036] Figure 5 It is a graph showing the relationship between time and torque when the hub ring and the outer ring rotate relative to each other.

[0037] Figure 6 It is a diagram showing the relationship between the rotational speed and torque when the hub ring and the outer ring rotate relative to each other.

[0038] Figure 7 This is a side sectional view showing a wheel bearing assembly with the small-diameter stepped portion of the hub ring riveted to the inner ring.

[0039] Figure 8 This is a graph showing the relationship between bearing preload and rotational torque.

[0040] Figure 9 This is a side sectional view showing the assembly of the inner side sealing member onto the inner side end of the outer ring after the rotational torque measurement process following riveting.

[0041] Figure 10 This is a side sectional view of a wheel bearing assembly showing the inner ring pressed into the small-diameter stepped portion of the wheel hub ring.

[0042] Figure 11 This is a graph showing the relationship between bearing preload and rotational torque in relation to ambient temperature.

[0043] Figure 12 This is a flowchart illustrating the pre-pressure inspection method of the third embodiment.

[0044] Figure 13 This is a graph showing the relationship between the riveting time and the temperature rise of the inner ring.

[0045] Figure 14 This is a graph showing the relationship between riveting time and the increase in rotational torque.

[0046] Figure 15 This is a graph showing the relationship between bearing preload and rotational torque.

[0047] Figure 16 This is a flowchart illustrating the pre-pressure inspection method of the fourth embodiment.

[0048] Figure 17 This is a side sectional view of a wheel bearing assembly without temperature measurement of the riveted parts in the wheel hub.

[0049] Figure 18This is a diagram showing the relationship between the temperature of the riveted part of the wheel hub and the temperature of the inner track surface of the inner ring.

[0050] Figure 19 It is a graph showing the relationship between temperature and time on the inner track surface of the inner ring.

[0051] Figure 20 This is a graph showing the relationship between the temperature difference before and after riveting and the change in rotational torque.

[0052] Figure 21 This is a graph showing the relationship between bearing preload and rotational torque.

[0053] Figure 22 This is a flowchart illustrating the pre-pressure inspection method of the fifth embodiment.

[0054] Figure 23 This is a side sectional view of a wheel bearing assembly showing the height and outer diameter of the riveted section measured by a contact-type measuring instrument.

[0055] Figure 24 This is a side sectional view of a wheel bearing assembly showing the height dimension of the riveted part being measured by a non-contact measuring device.

[0056] Figure 25A This is a diagram showing the relationship between the height dimension of the riveted part and the differential torque. Figure 25B This is a diagram showing the relationship between the outer diameter of the riveted part and the differential torque.

[0057] Figure 26 This is a flowchart illustrating the pre-pressure inspection method according to the sixth embodiment.

[0058] Figure 27 This is a side sectional view showing a wheel bearing assembly with the small-diameter stepped portion of the hub ring riveted to the inner ring.

[0059] Figure 28 This is a graph showing the relationship between the temperature of the riveted part and the increase in rotational torque.

[0060] Figure 29 This is a flowchart illustrating a first embodiment of a pre-pressure inspection method in the case of performing a temperature measurement process before riveting.

[0061] Figure 30 This is a side sectional view of a wheel bearing assembly showing the temperature of the part corresponding to the riveted part before the riveting process.

[0062] Figure 31 This is a flowchart illustrating a second embodiment of a pre-pressure inspection method in the case of performing a temperature measurement process before riveting. Detailed Implementation

[0063] Wheel bearing assembly

[0064] The following uses Figure 1 One embodiment of the wheel bearing device that implements the preload inspection method of the present invention, namely wheel bearing device 1, will be described.

[0065] Figure 1 The wheel bearing assembly 1 shown supports the wheel for free rotation in the suspension system of vehicles such as motor vehicles. The wheel bearing assembly 1 has a structure referred to as the third generation, comprising an outer ring 2 as an outer component, a hub ring 3 and an inner ring 4 as inner components, a double row of inner ball bearings 5 ​​and an outer ball bearing 6 as rolling elements, and an inner sealing member 9 and an outer sealing member 10. Here, "inner side" refers to the body side of the wheel bearing assembly 1 when mounted on the vehicle body, and "outer side" refers to the wheel side of the wheel bearing assembly 1 when mounted on the vehicle body. Furthermore, "axial direction" refers to the direction along the rotation axis of the wheel bearing assembly 1.

[0066] An inner opening 2a is formed at the inner end of the outer ring 2, which allows the inner sealing member 9 to be fitted. An outer opening 2b is formed at the outer end of the outer ring 2, which allows the outer sealing member 10 to be fitted. An inner outer track surface 2c and an outer outer track surface 2d are formed on the inner circumferential surface of the outer ring 2. A body mounting flange 2e for mounting the outer ring 2 to a body side member is integrally formed on the outer circumferential surface of the outer ring 2. A bolt hole 2g is provided on the body mounting flange 2e for inserting a fastening connection member (here, a bolt) for fastening the body side member to the outer ring 2.

[0067] At the inner end of the wheel hub 3, a small-diameter stepped portion 3a, which is smaller than that at the outer end, is formed on the outer circumferential surface. A shoulder portion 3e is formed at the outer end of the small-diameter stepped portion 3a in the wheel hub 3. A wheel mounting flange 3b for mounting a wheel is integrally formed at the outer end of the wheel hub 3. The wheel mounting flange 3b is provided with bolt holes 3f for pressing in wheel bolts to fasten the wheel hub 3 to a wheel or brake component.

[0068] In the hub ring 3, an inner track surface 3c on the outer side is provided opposite to the outer track surface 2d on the outer side of the outer ring 2. A lip sliding surface 3d is formed on the base side of the wheel mounting flange 3b in the hub ring 3 for sliding contact with the outer side sealing member 10. The outer side sealing member 10 is fitted into the outer side opening end of the annular space formed by the outer ring 2 and the hub ring 3. The hub ring 3 has an outer side end face 3g at the end that is further outward than the wheel mounting flange 3b.

[0069] An inner ring 4 is provided on the small-diameter stepped portion 3a of the hub ring 3. The inner ring 4 is fixed to the small-diameter stepped portion 3a of the hub ring 3 by pressing and riveting. The inner ring 4 applies preload to the inner side ball row 5 and the outer side ball row 6, which are rolling rows. The inner ring 4 has an inner side end face 4b at its inner side end and an outer side end face 4c at its outer side end. A riveting portion 3h is formed on the inner side end of the hub ring 3, which is riveted to the inner side end face 4b of the inner ring 4. It should be noted that the part of the inner ring 4 that is in close contact with the riveting portion 3h of the hub ring 3 is called the riveting portion 4d on the inner ring 4 side. The riveting portion 4d is a part of the inner side end face 4b. That is, the riveting portion in the wheel bearing assembly 1 is composed of the riveting portion 3h on the hub ring 3 side and the riveting portion 4d on the inner ring 4 side.

[0070] An inner track surface 4a is formed on the outer circumferential surface of the inner ring 4. That is, the inner track surface 4a is formed on the inner side of the hub ring 3 through the inner ring 4. The inner track surface 4a of the inner ring 4 is opposite to the outer track surface 2c on the inner side of the outer ring 2.

[0071] The inner ball bearing row 5 and the outer ball bearing row 6, which are rolling elements, are formed by a retainer 8 holding multiple balls 7 as rolling elements. The inner ball bearing row 5 is freely clamped between the inner track surface 4a of the inner ring 4 and the outer track surface 2c of the inner side of the outer ring 2. The outer ball bearing row 6 is freely clamped between the inner track surface 3c of the hub ring 3 and the outer track surface 2d of the outer side of the outer ring 2.

[0072] In the wheel bearing assembly 1, a double-row angular contact ball bearing is constituted by an outer ring 2, a hub ring 3, an inner ring 4, an inner square ball row 5, and an outer square ball row 6. It should be noted that the wheel bearing assembly 1 can also be constructed using a double-row tapered roller bearing.

[0073] [Pre-compression check method]

[0074] Next, the preload inspection method for the wheel bearing device 1 will be described using the first to sixth embodiments as examples.

[0075] <First Implementation>

[0076] like Figure 2As shown, the preload inspection method of this embodiment is performed midway through the assembly of the wheel bearing assembly 1. Specifically, the preload inspection method includes a temporary pressing-in process (S01), a pressing-in process (S02), a first bearing preload value calculation process (S03), a sealing process (S04), a post-pressing rotational torque measurement process (S05), a riveting process (S06), a post-riveting rotational torque measurement process (S07), a second bearing preload value calculation process (S08), a judgment process (S09), and an inner side sealing member assembly process (S10). The steps of the preload inspection method will be described below.

[0077] (Temporary pressing process)

[0078] like Figure 3 As shown, the hub ring 3 is placed on the support platform 11 with its axial direction perpendicular and its outer side end face 3g facing downwards. The outer side end face 3g of the hub ring 3 contacts the support platform 11. An outer ring 2 is mounted on the hub ring 3 placed on the support platform 11 in a manner that allows it to rotate via the inner side ball bearing row 5 and the outer side ball bearing row 6. An outer side sealing member 10 is fitted into the outer side end of the outer ring 2. Grease is filled between the hub ring 3 and the outer ring 2.

[0079] In the temporary pressing process (S01), the inner ring 4 is first temporarily pressed into the small-diameter stepped portion 3a of the hub ring 3, which is placed on the support platform 11. The temporary pressing of the inner ring 4 is performed as follows: the inner ring 4 is pressed into the small-diameter stepped portion 3a from above, and the pressing is stopped when the outer end face 4c of the inner ring 4 is about to abut against the shoulder 3e of the hub ring 3. Here, the pressing operation of the inner ring 4 is performed, for example, under a specified pressure using a pushing device such as a hydraulic cylinder or a pneumatic cylinder. At the point when the temporary pressing of the inner ring 4 is completed, there is an axial positive clearance G0 between the track surface (e.g., the outer track surface 2c and the inner track surface 4a) and the rolling element. This axial positive clearance G0 can be measured, for example, based on the axial movement of the outer ring 2.

[0080] In the temporary pressing process (S01), the axial positive clearance G0 between the track surface (e.g., the outer track surface 2c and the inner track surface 4a) and the rolling element is measured, as well as the axial dimension H0 between the outer end face 3g of the inner ring 4 after the temporary pressing of the inner ring 4 and the inner end face 4b of the inner ring 4. The axial dimension H0 can be measured by a measuring instrument 12 such as a dial indicator.

[0081] (Pressing process)

[0082] The pressing process (S02) is performed after the temporary pressing process (S01). For example... Figure 4As shown, in the pressing process (S02), the inner ring 4 is pressed into the small-diameter stepped portion 3a until the outer side end face 4c of the inner ring 4 abuts against the shoulder 3e of the hub ring 3. After the inner ring 4 is pressed into the small-diameter stepped portion 3a, the axial dimension H1 between the outer side end face 3g and the inner side end face 4b of the hub ring 3 after the inner ring 4 is pressed in is measured. In addition, the value obtained by subtracting the axial dimension H1 from the axial dimension H0 is subtracted from the axial positive clearance G0 between the track surface and the rolling element measured in the temporary pressing process (S01) to obtain the axial negative clearance G1 between the track surface and the rolling element after the inner ring 4 is pressed in (G1=G0-(H0-H1)).

[0083] (The process of calculating the preload value of the first bearing)

[0084] After the pressing-in process (S02), a first bearing preload calculation process (S03) is performed. In the first bearing preload calculation process (S03), the first bearing preload value P1 applied to the bearing after the pressing-in process is calculated based on the axial negative clearance G1. The first bearing preload value P1 is calculated as follows: the relationship between the axial negative clearance and the bearing preload value in the wheel bearing assembly 1 is determined in advance through experiments, etc., and the axial negative clearance G1 is substituted into this relationship. It should be noted that the relationship between the axial negative clearance and the bearing preload value can be determined according to the specifications of the wheel bearing assembly 1.

[0085] (Sealing process)

[0086] After the first bearing preload calculation step (S03), a sealing step (S04) is performed. In the sealing step (S04), by rotating the hub ring 3, to which the inner ring 4 is pressed, relative to the outer ring 2, the grease filled between the hub ring 3 and the outer ring 2 is sealed to the balls 7 of the inner ball row 5 and the outer ball row 6. In the sealing step (S04), the outer ring 2 can be pre-fixed and the hub ring 2 rotated, or the hub ring 3 can be pre-fixed and the outer ring 2 rotated.

[0087] By performing the sealing process (S04), the resistance generated between the grease and the ball bearing 7 can be kept constant when the hub ring 3 and the outer ring 2 rotate relative to each other. Therefore, when measuring the rotational torque of the wheel bearing assembly 1 in the subsequent pressing-in rotational torque measurement process (S05) and riveting-in rotational torque measurement process (S08), deviations in the measured rotational torque can be suppressed. It should be noted that, from the viewpoint of suppressing deviations in rotational torque, it is preferable to rotate the hub ring 3 and the outer ring 2 relative to each other for more than 30 revolutions in the sealing process (S04).

[0088] (Measurement of rotational torque after pressing)

[0089] After the sealing process (S04), a post-pressing rotational torque measurement process (S05) is performed. In the post-pressing rotational torque measurement process (S05), the post-pressing rotational torque Ta is measured by the torque measuring device 13 when the hub ring 3 and the outer ring 2 rotate relative to each other after the inner ring 4 is pressed into the small diameter step portion 3a. The post-pressing rotational torque Ta is the rotational torque measured after the pressing process (S02) and before the riveting process (S06). In the post-pressing rotational torque measurement process (S05), the outer ring 2 can be fixed in advance and the hub ring 3 can be rotated, or the hub ring 3 can be fixed in advance and the outer ring 2 can be rotated.

[0090] When the hub ring 3 is rotated, compared to when the outer ring 2 is rotated, the revolution speed of the balls 7 in the inner ball row 5 and the outer ball row 6 is slower. Therefore, the deviation of the rotational torque value measured when the rotational speed of the hub ring 3 changes is smaller. Thus, in the rotational torque measurement process, it is preferable to rotate the hub ring 3. It should be noted that when the hub ring 3 is rotated, it can be rotated by rotating the support platform 11 on which the hub ring 3 is mounted.

[0091] Additionally, in the post-pressing rotational torque measurement process (S05), the rotational torque is measured, not the bearing's starting torque. For example... Figure 5 As shown, the starting torque is the peak value of the initial torque when the bearing begins to rotate, but it decreases over time and varies considerably over time. Therefore, it lacks repeatability. In contrast, the rotational torque is the torque after the bearing begins to rotate, and it shows a constant value with almost no change over time. Therefore, in the post-pressing rotational torque measurement process (S05), by measuring the post-pressing rotational torque Ta as the rotational torque, the torque value of the bearing can be measured with high accuracy.

[0092] like Figure 6 As shown, the rotational torque of the bearing when the hub ring 3 and the outer ring 2 rotate relative to each other increases with increasing speed within a range where the speed of the hub ring 3 or the outer ring 2 is constant. However, when the speed of the hub ring 3 or the outer ring 2 is extremely low, it decreases with increasing speed, and then begins to increase again. In other words, there exists a region where the rotational torque of the bearing changes from decreasing to increasing with increasing speed, and in this region, the variation of the rotational torque with respect to the change in speed is relatively small.

[0093] In the post-pressing rotational torque measurement process (S05), the hub ring 3 or outer ring 2 is rotated at a constant speed to ensure that the measured rotational torque does not deviate. Furthermore, the speed of the hub ring 3 or outer ring 2 is set to the range N1 to N2, within the region where the rotational torque transitions from decreasing to increasing. Therefore, even if the speed changes during the measurement of the post-pressing rotational torque Ta, the variation in rotational torque can be reduced.

[0094] In the post-pressing rotational torque measurement process (S05), the rotational torque is measured under conditions where dynamic friction occurs between the inner components 3 and 4 and the outer component 2. Specifically, the rotational torque is measured under conditions where dynamic friction occurs between the inner components 3 and 4 and the rolling element 7, between the hub ring 3 and the outer side sealing component 10, and between the outer ring 2 and the rolling element 7 and the outer side sealing component 10. Generally, the coefficient of dynamic friction is smaller than the coefficient of static friction and has a smaller deviation, thus enabling high-precision measurement of the rotational torque.

[0095] The lower limit of the rotational speed range, N1, is preferably set to 10 rpm, which allows for the measurement of rotational torque under conditions of dynamic friction. The upper limit of the rotational speed range, N2, is preferably set to 60 rpm, which minimizes the stirring resistance of the grease filled between the hub ring 3 and the outer ring 2. This allows for the measurement of rotational torque with high accuracy.

[0096] Furthermore, within the range of 10 rpm to 60 rpm, the rotational speed of the hub ring 3 or the outer ring 2 is preferably set to a range of 10 rpm to 30 rpm where the change in rotational torque with respect to the rotational speed is minimal. This allows for more accurate measurement of the rotational torque.

[0097] In this way, in the post-pressing rotational torque measurement process (S05), the hub ring 3 or the outer ring 2 is rotated within a small rotational speed range N1~N2 where the change in rotational torque relative to the change in rotational speed is smaller. Thus, even if the rotational speed of the hub ring 3 or the outer ring 2 changes, the change in rotational torque can be suppressed to a minimum, thereby enabling high-precision measurement of rotational torque.

[0098] Furthermore, in the post-pressing rotational torque measurement process (S05), the rotational torque of the wheel bearing assembly 1 is measured with the outer side sealing member 10 fitted into the outer side opening end of the annular space formed by the outer ring 2 and the hub ring 3. Here, the outer side sealing member 10 is located on the side opposite in the axial direction to the small-diameter stepped portion 3a of the hub ring 3, which is riveted to fix the inner ring 4. Therefore, in the riveting process (S06) described next, even if an abnormality occurs in the inner ring track surface 4a, it is difficult to affect the sealing torque of the outer side sealing member 10, and the rotational torque of the wheel bearing assembly 1 is not easily changed.

[0099] (Riveting process)

[0100] After the pressing-in rotational torque measurement process (S05), a riveting process (S06) is performed. In the riveting process (S06), the inner side end of the small-diameter stepped portion 3a in the hub ring 3 is riveted to the inner side end face 4b of the inner ring 4. For example... Figure 7As shown, riveting can be performed, for example, by using a riveting tool such as a riveting punch 14 for oscillating riveting. Riveting by oscillating riveting is performed, for example, by lowering the riveting punch 14 above the small-diameter stepped portion 3a disposed in the hub ring 3 to abut against the inner end of the small-diameter stepped portion 3a, and oscillating the riveting punch 14 while abutting against the small-diameter stepped portion 3a. When the riveting is completed, the riveting punch 14 is raised and moves away from the small-diameter stepped portion 3a. After the riveting is performed, an axial negative clearance is generated between the inner ring 4 and the hub ring 3.

[0101] (Riveting torque measurement process)

[0102] After the riveting process (S06), a post-riveting rotational torque measurement process (S07) is performed. In the post-riveting rotational torque measurement process (S07), similar to the post-pressing rotational torque measurement process, the rotational torque is measured under conditions of dynamic friction between the inner components 3 and 4 and the outer component 2. In the post-riveting rotational torque measurement process (S07), the post-riveting rotational torque Tb is measured by the torque measuring device 13 when the hub ring 3, after the small-diameter stepped portion 3a is riveted to the inner ring 4, rotates relative to the outer ring 2. The post-riveting rotational torque Tb is the rotational torque measured after the riveting process (S06) and before the inner side sealing component assembly process (S10). In the post-riveting rotational torque measurement process (S07), the outer ring 2 can be pre-fixed and the hub ring 3 rotated, or the hub ring 3 can be pre-fixed and the outer ring 2 rotated.

[0103] However, similar to the case of the post-pressing rotational torque measurement step (S05), since the deviation of the measured rotational torque value is small when the rotational speed of the hub ring 3 changes, it is preferable to rotate the hub ring 3. Furthermore, in the post-riveting rotational torque measurement step (S07), similar to the case of the post-pressing rotational torque measurement step (S05), the rotational torque is measured instead of the bearing's starting torque. By measuring the post-riveting rotational torque Tb while rotating the hub ring 3 or the outer ring 2 at a constant speed within a low speed range of N1 to N2, the rotational torque can be measured with high accuracy.

[0104] In this case, for speeds N1 and N2, similarly to the case of the post-riveting rotational torque measurement step (S05), it is preferable to set speed N1 to 10 rpm and speed N2 to 60 rpm. In this embodiment, within the range of 10 rpm to 60 rpm, the speed of the hub ring 3 or outer ring 2 is set to a speed of 10 rpm to 30 rpm, where the change in rotational torque with respect to speed is minimal. Therefore, even if the speed changes during the measurement of the post-riveting rotational torque Tb, the change in post-riveting rotational torque Tb can be reduced, thereby enabling stable measurement of the rotational torque.

[0105] Furthermore, the same process as the sealing process (S04) can be performed between the riveting process (S06) and the post-riveting rotational torque measurement process (S07), namely, the sealing process in which the grease filled between the hub ring 3 and the outer ring 2 seals 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 balls 7 when the hub ring 3 and the outer ring 2 rotate relative to each other can be kept constant, thereby further suppressing the deviation of the measured post-riveting rotational torque Tb when measuring the post-riveting rotational torque Tb of the wheel bearing assembly 1 in the post-riveting rotational torque measurement process (S07).

[0106] However, if the grease and the ball 7 are fully sealed by the sealing process (S04) and the resistance generated between the grease and the ball 7 is constant, the sealing process between the riveting process (S06) and the riveting torque measurement process (S07) can be omitted.

[0107] (The process of calculating the preload value of the second bearing)

[0108] After the riveting rotational torque measurement step (S07), the second bearing preload calculation step (S08) is performed. In the second bearing preload calculation step (S08), the difference torque ΔT between the pressing-in rotational torque Ta and the riveting rotational torque Tb is calculated (Tb-Ta=ΔT). Then, based on the difference torque ΔT, the preload change ΔP between the pressing-in step and the riveting process is calculated. Then, the second bearing preload value P2 is calculated by adding the preload change ΔP to the first bearing preload value P1 calculated in the first bearing preload calculation step (S03).

[0109] In this case, the differential torque ΔT is the increased rotational torque due to the riveting process performed in the riveting process (S06). Additionally, the preload change ΔP is the increased preload due to the riveting process performed in the riveting process (S06). Figure 8As shown, the preload change ΔP is calculated as follows: the relationship between the bearing preload and the bearing rotational torque of the wheel bearing assembly 1 is determined beforehand through experiments, and the difference torque ΔT is substituted into this relationship. It should be noted that the relationship between the bearing preload and the bearing rotational torque can be determined according to the specifications of the wheel bearing assembly 1.

[0110] (Judgment process)

[0111] After the second bearing preload value calculation step (S08), a judgment step (S09) is performed. In the judgment step (S09), it is determined whether the preload applied to the wheel bearing assembly 1 is appropriate based on whether the second bearing preload value P2 is within the range of a specified reference value. In the judgment step (S09), if the second bearing preload value P2 is within the range of the specified reference value, it is determined that the preload applied to the wheel bearing assembly 1 is appropriate; if the second bearing preload value P2 is not within the range of the specified reference value, it is determined that the preload applied to the wheel bearing assembly 1 is inappropriate.

[0112] In the second bearing preload calculation process (S08), based on the preload change ΔP caused by the riveting process obtained by using the post-riveting rotational torque Ta and the post-riveting rotational torque Tb as the rotational torque before and after the riveting process, the second bearing preload value P2 is calculated.

[0113] Thus, when calculating the preload using the rotational torque before and after riveting, if anomalies such as shape distortion of the inner raceway surface occur during riveting, the increase in rotational torque before and after riveting becomes larger, causing the calculated second bearing preload value P2 to deviate from the specified reference value range. Therefore, by judging the calculated second bearing preload value P2 in the judgment process (S09), it is possible to detect abnormalities that have occurred in the wheel bearing assembly 1 after riveting, thereby improving the reliability of the measured value of the preload applied to the wheel bearing assembly 1. As a result, the preload applied to the wheel bearing assembly 1 can be checked with higher reliability.

[0114] Furthermore, the rotational torques Ta and Tb after riveting, used in calculating the second bearing preload value P2, are values ​​measured for the same wheel bearing assembly 1. Therefore, the difference in torque ΔT between the rotational torque Ta and Tb does not include deviations of each individual wheel bearing assembly 1, such as the interference fit of the outer side sealing member 10 lip or the amount of grease filled between the hub ring 3 and the outer ring 2; it only extracts the increase in rotational torque caused by the riveting process. As a result, the second bearing preload value P2 can be calculated with high precision based on the difference in torque ΔT, thereby enabling a high-precision determination in the judgment process (S09) of whether the preload applied to the wheel bearing assembly 1 is appropriate.

[0115] In addition, the reference value used in the judgment process (S09) to determine whether the preload is appropriate is set with consideration of the deviation of the rotational torque caused by the riveting process of riveting the small diameter step 3a to the inner ring 4.

[0116] In other words, the difference between the pressing-in rotational torque Ta and the riveting rotational torque Tb sometimes includes deviations caused by the movement of the grease between the hub ring 3 and the outer ring 2 before and after the riveting process, as well as changes in the contact between the outer side sealing member 10 and the hub ring 3 and the outer ring 2. Furthermore, the difference between the pressing-in rotational torque Ta measured before the riveting process and the riveting rotational torque Tb measured after the riveting process sometimes includes repeating deviations in the rotational torque measurements.

[0117] Therefore, in this embodiment, these deviations are taken into account, and the range of the reference value is set to a smaller range compared to the case where deviations are not considered. As a result, it is possible to determine with high accuracy whether the preload applied to the wheel bearing device 1 is appropriate in the determination process (S09), thereby suppressing the occurrence of misdetermination.

[0118] (Inner side sealing component assembly process)

[0119] The inner side sealing component assembly process (S10) is performed after the judgment process (S09). By performing the inner side sealing component assembly process (S10), the assembly process of the wheel bearing assembly 1 is completed. It should be noted that the inner side sealing component assembly process (S10) can be performed after the riveting rotational torque measurement process (S07), and can be performed before the judgment process (S09) or before the second bearing preload value calculation process (S08). Figure 9 As shown, in the inner side sealing component assembly process (S10), the inner side sealing component 9 is fitted into the inner side opening 2a of the outer ring 2, thereby assembling the inner side sealing component 9 between the inner side end of the outer ring 2 and the inner side end of the inner ring 4.

[0120] If the inner square sealing member 9 is assembled before the riveting process (S06), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to factors such as the degree of riveting of the hub ring 3 in the riveting process (S06). Furthermore, even after the riveting process (S06), if the inner square sealing member 9 is assembled before the post-riveting rotational torque measurement process (S07), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to the assembly state of the inner square sealing member 9.

[0121] Therefore, if the inner side sealing member 9 is assembled before the riveting process (S06) or the riveting rotational torque measurement process (S07), it may affect the deviation of the riveting rotational torque Tb measured in the riveting rotational torque measurement process (S07). Similarly, if the inner side sealing member 9 is assembled before the pressing rotational torque measurement process (S05), the assembly state of the inner side sealing member 9 may affect the deviation of the pressing rotational torque Ta measured in the pressing rotational torque measurement process (S05).

[0122] However, in this embodiment, the inner side sealing member assembly process (S10) is performed after the riveting rotational torque measurement process (S07). Therefore, when measuring the riveting rotational torque Ta and riveting rotational torque Tb of the wheel bearing device 1 in the pressing rotational torque measurement process (S05) and the riveting rotational torque measurement process (S07), no deviation in rotational torque caused by the influence of the inner side sealing member 9 occurs, thereby enabling high-precision measurement of the rotational torque of the wheel bearing device 1.

[0123] In this embodiment, the inner side sealing member assembly process (S10) is performed after the riveting rotational torque measurement process (S07), but a structure in which the cover member assembly process is performed after the riveting rotational torque measurement process (S07) can also be adopted. In this case, in the cover member assembly process, the cover member replaces the inner side sealing member 9 and is fitted into the inner side opening 2a of the outer ring 2, and the inner side opening 2a is blocked by the cover member.

[0124] <Second Implementation>

[0125] like Figure 2 As shown, the pre-pressure inspection method of this embodiment includes a temporary pressing process (S01), a pressing process (S02), a first bearing pre-pressure value calculation process (S03), a sealing process (S04), a post-pressing rotational torque measurement process (S05), a riveting process (S06), a post-riveting rotational torque measurement process (S07), a second bearing pre-pressure value calculation process (S08), a judgment process (S09), and an inner side sealing component assembly process (S10). The following describes each step of the pre-pressure inspection method.

[0126] (Temporary pressing process)

[0127] The process is the same as that in the first embodiment, so the description is omitted.

[0128] (Pressing process)

[0129] The process is the same as that in the first embodiment, so the description is omitted.

[0130] (The process of calculating the preload value of the first bearing)

[0131] The process is the same as that in the first embodiment, so the description is omitted.

[0132] (Sealing process)

[0133] The process is the same as that in the first embodiment, so the description is omitted.

[0134] (Measurement of rotational torque after pressing)

[0135] Perform the same procedures as in the first implementation method.

[0136] Additionally, in the post-pressing rotational torque measurement process (S05), the ambient temperature A around the wheel bearing assembly 1 is also measured. For example, as... Figure 10 As shown, a temperature sensor 140 can also be installed on the torque measuring device 13 to measure the ambient temperature near the outer ring 2. It should be noted that in the preload check method of this embodiment, there is no process of rotating the wheel bearing assembly 1 at high speed as it does during use; therefore, the ambient temperature A remains approximately constant throughout all steps of the preload check method. Therefore, the measurement of the ambient temperature A can be performed in any of the steps from the temporary pressing step (S01) to the second bearing preload value calculation step (S08).

[0137] (Riveting process)

[0138] The process is the same as that in the first embodiment, so the description is omitted.

[0139] (Riveting torque measurement process)

[0140] The process is the same as that in the first embodiment, so the description is omitted.

[0141] (The process of calculating the preload value of the second bearing)

[0142] After the riveting rotational torque measurement step (S07), the second bearing preload calculation step (S08) is performed. In the second bearing preload calculation step (S08), the difference torque ΔT between the pressing-in rotational torque Ta and the riveting rotational torque Tb is calculated (Tb-Ta=ΔT). Then, based on the difference torque ΔT, the preload change ΔP between the pressing-in step and the riveting process is calculated. Then, the second bearing preload value P2 is calculated by adding the preload change ΔP to the first bearing preload value P1 calculated in the first bearing preload calculation step (S03).

[0143] In this case, the differential torque ΔT is the rotational torque increased by the riveting process performed in the riveting process (S06). Additionally, the preload change ΔP is the preload increased by the riveting process performed in the riveting process (S06). To calculate the preload change ΔP, as follows... Figure 11 As shown, the relationship between the bearing preload and the bearing rotational torque of the wheel bearing assembly 1 was determined in advance through experiments and other methods based on multiple ambient temperatures. Figure 11 In the diagram, the dashed line indicates ambient temperature A1, the solid line indicates ambient temperature A2 (A2 > A1), and the single-dotted line indicates ambient temperature A3 (A3 > A2). Furthermore, the preload change ΔP is calculated as follows: a relationship corresponding to the ambient temperature A measured in the post-pressurization rotational torque measurement step (S05) is selected (ambient temperature A2 is selected in this embodiment), and as shown... Figure 8 As shown, the differential torque ΔT is substituted into this relationship.

[0144] It should be noted that the relationship between the bearing preload and the bearing rotational torque can be determined according to the specifications of wheel bearing assembly 1. Additionally, in Figure 11 The example provided is for three ambient temperatures A1 to A3, but it is not limited to these. As long as the relationship between bearing preload and bearing rotational torque under two or more ambient temperatures is used, the accuracy will be improved as the number of such relationships increases.

[0145] For the rotational torque Ta after pressing and the rotational torque Tb after riveting, the measured values ​​will deviate even in wheel bearing assemblies 1 with the same positive axial clearance G0 or negative axial clearance G1, depending on the ambient temperature A at the time of measurement. This is because the viscosity of the grease filling between the hub ring 3 and the outer ring 2 changes, causing changes in the grease film thickness on the surface of the balls 7 in the inner ball row 5 and the outer ball row 6, thus changing the contact area of ​​the balls 7. Therefore, by using the relationship between the bearing preload and the bearing rotational torque corresponding to the ambient temperature A as described above, the preload change ΔP can be calculated based on the difference torque ΔT, resulting in a highly reliable preload change ΔP. Furthermore, since a second bearing preload value P2 is calculated based on the highly reliable preload change ΔP taking into account the ambient temperature A, the reliability of the measured value of the preload applied to the wheel bearing assembly 1 can be improved.

[0146] (Judgment process)

[0147] The process is the same as that in the first embodiment, so the description is omitted.

[0148] (Inner side sealing component assembly process)

[0149] The process is the same as that in the first embodiment, so the description is omitted.

[0150] In this embodiment, the ambient temperature A around the wheel bearing assembly 1 is measured in the post-pressing rotational torque measurement step (S05). In the second bearing preload calculation step (S08), a relationship between the bearing preload and the bearing rotational torque corresponding to the ambient temperature A is selected, and the difference torque ΔT is substituted into this relationship to calculate the preload change ΔP. However, the surface temperature B of the wheel bearing assembly 1 can also be used instead of the ambient temperature A. That is, the surface temperature B of the wheel bearing assembly 1 can be measured in the post-pressing rotational torque measurement step (S05), and in the second bearing preload calculation step (S08), a relationship between the bearing preload and the bearing rotational torque corresponding to the surface temperature B is selected, and the difference torque ΔT is substituted into this relationship to calculate the preload change ΔP. It is assumed that the surface temperature B of the wheel bearing assembly 1 and the ambient temperature A generally show approximately the same temperature. For example, the surface of the outer ring 2 can be selected as the location for measuring the surface temperature B. As the measuring mechanism for the surface temperature B, a contact temperature sensor or a non-contact temperature sensor can be used.

[0151] <Third Implementation>

[0152] like Figure 12 As shown, the pre-pressure inspection method of this embodiment includes a temporary pressing process (S21), a pressing process (S22), a first bearing pre-pressure value calculation process (S23), a sealing process (S24), a post-pressing rotational torque measurement process (S25), a riveting process (S26), a processing time determination process (S27), a post-riveting rotational torque measurement process (S28), a rotational torque correction process (S29), a second bearing pre-pressure value calculation process (S30), a determination process (S31), and an inner side sealing component assembly process (S32). The following describes each step of the pre-pressure inspection method.

[0153] (Temporary pressing process)

[0154] The process is the same as that in the first embodiment, so the description is omitted.

[0155] (Pressing process)

[0156] The process is the same as that in the first embodiment, so the description is omitted.

[0157] (The process of calculating the preload value of the first bearing)

[0158] The process is the same as that in the first embodiment, so the description is omitted.

[0159] (Sealing process)

[0160] The process is the same as that in the first embodiment, so the description is omitted.

[0161] (Measurement of rotational torque after pressing)

[0162] The process is the same as that in the first embodiment, so the description is omitted.

[0163] (Riveting process)

[0164] Perform the same procedures as in the first implementation method.

[0165] In addition, during the riveting process (S26), the time required for riveting is measured, i.e., the riveting time t. In this embodiment, the measured riveting time t is the time from the point when the riveting punch 14 begins to descend in order to perform the riveting process to the point when the riveting punch 14 begins to rise after the riveting process is completed.

[0166] (Processing time determination procedure)

[0167] After the riveting process (S26), a processing time determination process (S27) is performed. In the processing time determination process (S27), it is determined whether the measured riveting processing time t exceeds a predetermined upper limit value. In step S27, if it is determined that the riveting processing time t does not exceed the predetermined upper limit value (S27; No), the post-riveting rotational torque measurement process (S28) is then performed. On the other hand, if it is determined in step S27 that the riveting processing time t exceeds the predetermined upper limit value (S27; Yes), the riveted wheel bearing device 1 is discharged as a NG product (S33). In this embodiment, the predetermined upper limit value is set to 20 seconds.

[0168] (Riveting torque measurement process)

[0169] If the measured riveting processing time t does not exceed the specified upper limit, the riveting rotation torque measurement process (S28) is performed after the processing time determination process (S27), similar to the first embodiment.

[0170] (Rotational torque correction process)

[0171] A rotational torque correction step (S29) is performed after the riveting rotational torque measurement step (S28). In the rotational torque correction step (S29), the riveting rotational torque Tb measured in the riveting rotational torque measurement step (S28) is corrected based on the temperature rise of the inner ring 4 caused by the riveting process, and the corrected riveting rotational torque Tc is calculated.

[0172] When the riveting process of riveting the small-diameter stepped portion 3a of the hub ring 3 to the inner ring 4 is performed, the riveting portion 3h in the small-diameter stepped portion 3a undergoes plastic deformation, resulting in a temperature rise. Furthermore, the heat from the riveting portion 3h in the small-diameter stepped portion 3a is transferred to the inner ring 4, causing the temperature of the inner ring 4 to rise. Because the inner ring 4 expands due to the temperature rise, the post-riveting rotational torque Tb measured in the post-riveting rotational torque measurement step (S28) is a larger value compared to the case where no temperature rise caused by the riveting process occurs.

[0173] In this case, the temperature rise of the inner ring 4 caused by the riveting process is correlated with the riveting time t, showing that the temperature rise of the inner ring 4 increases with the increase of the riveting time t (refer to...). Figure 13 The curves shown are R1a, R1b, and R1c. Furthermore, the inner ring 4 expands as the temperature rises; therefore, if the temperature rise of the inner ring 4 increases, the increase in the rotational torque Tb after riveting also increases.

[0174] Therefore, the riveting processing time t is correlated with the increase in rotational torque Ti, which is the increase in rotational torque Tb after riveting. There exists a relationship where the increase in rotational torque Ti increases with the increase in riveting processing time t (refer to...). Figure 14 The curves shown are R2a, R2b, and R2c.

[0175] Therefore, in the rotational torque correction process (S29), the following is used: Figure 14 The relationship between the riveting processing time t and the increase in rotational torque Ti is shown. The increase in rotational torque Ti is calculated based on the riveting processing time t measured in the riveting process (S26). The calculated increase in rotational torque Ti is then subtracted from the rotational torque Tb after riveting, thereby calculating the corrected rotational torque Tc (Tc=Tb-Ti).

[0176] It should be noted that it is possible to determine this in advance through experiments, etc. Figure 14 The relationship between the riveting time t and the increase in rotational torque Ti is shown. In this case, the relationship between the riveting time t and the increase in rotational torque Ti can be determined, for example, within a range before the riveting time t reaches a predetermined time. Furthermore, the relationship between the riveting time t and the increase in rotational torque Ti can be determined according to the specifications of the wheel bearing assembly 1.

[0177] Figure 13 The relationship between the riveting time t and the temperature rise of the inner ring 4 shown varies depending on the ambient temperature around the wheel bearing assembly 1 when the rotational torque Tb after riveting is measured. For the same riveting time t, the higher the ambient temperature, the smaller the temperature rise. For example, in... Figure 13In the figure, curve R1a shows the relationship when the ambient temperature is a℃, curve R1b shows the relationship when the ambient temperature is b℃ (b℃ > a℃), which is higher than a℃, and curve R1c shows the relationship when the ambient temperature is c℃ (c℃ > b℃), which is higher than b℃.

[0178] Similarly, Figure 14 The relationship between the riveting time t and the increase in rotational torque Ti shown varies depending on the ambient temperature around the wheel bearing assembly 1 when the rotational torque Tb after riveting is measured. For the same riveting time t, the higher the ambient temperature, the smaller the increase in rotational torque Ti. For example, in... Figure 14 In the diagram, curve R2a shows the relationship when the ambient temperature is a℃, curve R2b shows the relationship when the ambient temperature is b℃, and curve R1c shows the relationship when the ambient temperature is c℃.

[0179] Thus, the relationship between riveting time t and the increase in rotational torque Ti varies depending on the ambient temperature. Therefore, in the preload inspection method, when the relationship between riveting time t and the increase in rotational torque Ti is pre-determined for multiple ambient temperatures, and the increase in rotational torque Ti is calculated based on the riveting time t, the increase in rotational torque Ti is determined from these multiple relationships using the relationship between riveting time t and the increase in rotational torque Ti corresponding to the ambient temperature during riveting.

[0180] For example, when the ambient temperature is b℃ when measuring the rotational torque Tb after riveting, the relationship between the riveting processing time t corresponding to b℃ and the increase in rotational torque Ti is shown. Figure 9 The increase in rotational torque Ti is calculated from the curve R2b based on the riveting processing time t. This allows for the precise calculation of the increase in rotational torque Ti.

[0181] (The process of calculating the preload value of the second bearing)

[0182] After the rotational torque correction step (S29), the second bearing preload calculation step (S30) is performed. In the second bearing preload calculation step (S30), the difference torque ΔT (Tc-Ta=ΔT) between the rotational torque Ta after pressing and the rotational torque Tc after riveting correction is calculated. Then, based on the difference torque ΔT, the preload change ΔP between the pressing and riveting processes is calculated. Then, the second bearing preload value P2 is calculated by adding the preload change ΔP to the first bearing preload value P1 calculated in the first bearing preload calculation step (S23).

[0183] In this case, the differential torque ΔT is the rotational torque increased by the riveting process performed in the riveting process (S26). Additionally, the preload change ΔP is the preload increased by the riveting process performed in the riveting process (S26). Both the differential torque ΔT and the preload change ΔP are values ​​obtained after removing the effect of the temperature rise of the inner ring 4 caused by the riveting process.

[0184] like Figure 15 As shown, the preload change ΔP is calculated as follows: the relationship between the bearing preload and the bearing rotational torque of the wheel bearing assembly 1 is determined beforehand through experiments, and the difference torque ΔT is substituted into this relationship. It should be noted that the relationship between the bearing preload and the bearing rotational torque can be determined according to the specifications of the wheel bearing assembly 1.

[0185] In the second bearing preload calculation step (S30), the first bearing preload value P1 is calculated based on the axial negative clearance G1 between the track surface and the rolling element measured in the pressing step (S22), and the preload change ΔP is calculated based on the rotational torque Ta after pressing and the rotational torque Tc after riveting correction. Therefore, the second bearing preload value P2 can be calculated with high accuracy.

[0186] (Judgment process)

[0187] After the second bearing preload value calculation step (S30), a judgment step (S31) is performed. In the judgment step (S31), the quality of the preload applied to the wheel bearing device 1 is determined based on whether the second bearing preload value P2 is within the range of the specified reference value.

[0188] In the judgment process (S31), if the preload value P2 of the second bearing is within the range of the specified reference value, a judgment is made that the preload applied to the wheel bearing assembly 1 is appropriate, i.e., a good judgment (S31; Yes), and then the inner side sealing member assembly process (S32) is carried out. On the other hand, in the judgment process (S31), if the preload value P2 of the second bearing is not within the range of the specified reference value, a judgment is made that the preload applied to the wheel bearing assembly 1 is inappropriate, i.e., a bad judgment (S31; No), and the wheel bearing assembly 1 is discharged as an NG product (S33).

[0189] In the second bearing preload calculation step (S30), the preload change ΔP is calculated based on the corrected post-riveting rotational torque Tc obtained after removing the influence of the temperature rise of the inner ring 4 caused by the riveting process. Therefore, the second bearing preload value P2 can be calculated with high accuracy. As a result, in the judgment step (S11), the influence of the temperature rise of the inner ring 4 caused by the riveting process can be suppressed, thereby judging the quality of the preload applied to the wheel bearing assembly 1 with higher accuracy.

[0190] In particular, in the rotational torque correction process (S29), the increase in rotational torque Tb caused by the temperature rise of the inner ring 4 due to the riveting process is calculated based on the riveting processing time t. Therefore, by subtracting the increase in rotational torque Ti from the rotational torque Tb after riveting, the corrected rotational torque Tc after riveting is calculated, and the corrected rotational torque Tc after riveting can be calculated easily and with high accuracy.

[0191] Furthermore, by calculating the corrected riveting rotational torque Tc based on the riveting processing time t in the rotational torque correction process (S29), it is not necessary to wait for the temperature of the inner ring 4 to return to the temperature before riveting before measuring the riveting rotational torque Tb after the riveting process (S26). Therefore, the riveting rotational torque Tb can be measured for all wheel bearing assemblies 1 in a manner that does not reduce production efficiency on the mass production line, and the quality of the preload applied to the wheel bearing assembly 1 can be determined. Moreover, the pressing rotational torque Ta and the riveting rotational torque Tb can be measured in the same process equipment, thus enabling the correlation between the values ​​of the pressing rotational torque Ta and the riveting rotational torque Tb for all wheel bearing assemblies 1.

[0192] Furthermore, when calculating the preload using the rotational torque before and after riveting, if anomalies such as shape distortion of the inner raceway surface occur during riveting, the increase in rotational torque before and after riveting becomes larger, causing the calculated second bearing preload value P2 to deviate from the specified reference value range. Therefore, by judging the calculated second bearing preload value P2 in the judgment process (S31), it is possible to detect abnormalities that have occurred in the wheel bearing assembly 1 after riveting, thereby improving the reliability of the measured value of the preload applied to the wheel bearing assembly 1. Thus, the preload applied to the wheel bearing assembly 1 can be checked with higher reliability.

[0193] Furthermore, in the rotational torque correction process (S29), the rotational torque increase Ti is calculated using the relationship between the riveting processing time t and the rotational torque increase Ti, which is derived from the relationship between the riveting processing time t and the rotational torque increase Ti corresponding to the ambient temperature during riveting. This allows for a high-precision calculation of the rotational torque increase Ti, thereby enabling a more accurate determination of the quality of the preload applied to the wheel bearing assembly 1.

[0194] In addition, for Figure 14 Regarding the relationship between the riveting time t and the increase in rotational torque Ti shown, even if it falls outside the range determined experimentally, it can still be inferred based on the relationship within the experimentally determined range. However, if the riveting time t deviates significantly from the range determined experimentally, the error in the inferred relationship between the riveting time t and the increase in rotational torque Ti increases, making it difficult to calculate the increase in rotational torque Ti with high accuracy based on the riveting time t.

[0195] Therefore, in this preload inspection method, in the processing time determination process (S27), it is determined whether the riveting processing time t exceeds the specified upper limit value. If it is determined that the riveting processing time t exceeds the specified upper limit value, it is considered that it is difficult to correct the rotational torque Tb after riveting with high precision, and the wheel bearing device 1 that has undergone riveting processing is discharged as NG product.

[0196] This improves the accuracy of the corrected riveting torque Tc calculated in the rotational torque correction process (S29) performed after the processing time determination process (S07), thereby enabling a higher accuracy in determining the quality of the preload applied to the wheel bearing device 1 in the determination process (S31).

[0197] (Inner side sealing component assembly process)

[0198] The inner side sealing component assembly process (S32) is performed after the judgment process (S31). By performing the inner side sealing component assembly process (S32), the assembly process of the wheel bearing assembly 1 is completed. It should be noted that the inner side sealing component assembly process (S32) can be performed after the riveting rotational torque measurement process (S28), but it can be performed before the judgment process (S31), before the second bearing preload value calculation process (S30), or before the rotational torque correction process (S09). Figure 9 As shown, in the inner side sealing component assembly process (S32), the inner side sealing component 9 is fitted into the inner side opening 2a of the outer ring 2, thereby assembling the inner side sealing component 9 between the inner side end of the outer ring 2 and the inner side end of the inner ring 4.

[0199] If the inner square sealing member 9 is assembled before the riveting process (S26), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to factors such as the degree of riveting of the hub ring 3 in the riveting process (S26). Furthermore, even after the riveting process (S26), if the inner square sealing member 9 is assembled before the post-riveting rotational torque measurement process (S28), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to the assembly state of the inner square sealing member 9.

[0200] Therefore, if the inner side sealing member 9 is assembled before the riveting process (S26) or the riveting rotational torque measurement process (S28), it may affect the deviation of the riveting rotational torque Tb measured in the riveting rotational torque measurement process (S28). Similarly, if the inner side sealing member 9 is assembled before the pressing rotational torque measurement process (S25), the assembly state of the inner side sealing member 9 may affect the deviation of the pressing rotational torque Ta measured in the pressing rotational torque measurement process (S25).

[0201] However, in this embodiment, the inner side sealing member assembly process (S32) is performed after the riveting rotational torque measurement process (S28). Therefore, when measuring the riveting rotational torque Ta and riveting rotational torque Tb of the wheel bearing device 1 in the pressing rotational torque measurement process (S25) and the riveting rotational torque measurement process (S28), no deviation in rotational torque caused by the influence of the inner side sealing member 9 occurs, thereby enabling high-precision measurement of the rotational torque of the wheel bearing device 1.

[0202] In this embodiment, the inner side sealing member assembly process (S32) is performed after the riveting rotational torque measurement process (S28), but a structure in which the cover member assembly process is performed after the riveting rotational torque measurement process (S28) can also be adopted. In this case, in the cover member assembly process, the cover member replaces the inner side sealing member 9 and is fitted into the inner side opening 2a of the outer ring 2, and the inner side opening 2a is blocked by the cover member.

[0203] <Fourth Implementation>

[0204] like Figure 16As shown, the preload inspection method of this embodiment includes a temporary pressing process (S41), a pressing process (S42), a first inner ring height measurement process (S43), a first bearing preload value calculation process (S44), a sealing process (S45), a post-pressurization rotational torque measurement process (S46), a riveting process (S47), a temperature measurement process (S48), a post-riveting rotational torque measurement process (S49), a rotational torque correction process (S50), a second bearing preload value calculation process (S51), a judgment process (S52), and an inner side sealing component assembly process (S53). The following describes each step of the preload inspection method.

[0205] (Temporary pressing process)

[0206] The process is the same as that in the first embodiment, so the description is omitted.

[0207] (Pressing process)

[0208] The pressing process (S42) is performed after the temporary pressing process (S41). For example... Figure 4 As shown, in the pressing process (S42), the inner ring 4 is pressed into the small diameter step portion 3a until the outer side end face 4c of the inner ring 4 abuts against the shoulder portion 3e of the hub ring 3.

[0209] (First inner ring height measurement process)

[0210] The first inner ring height measurement process (S43) is performed after the pressing process (S42). Figure 4 As shown, in the inner ring height measurement process (S43), after the inner ring 4 is pressed into the small diameter step portion 3a, the axial dimension between the outer side end face 3g of the hub ring 3 after the inner ring 4 is pressed in and the inner side end face 4b of the inner ring 4 is measured, which is the first inner ring height H1. Then, the value obtained by subtracting the first inner ring height H1 from the axial dimension H0 is subtracted from the axial positive clearance G0 between the track surface and the rolling element measured in the temporary pressing process (S41), thereby calculating the axial negative clearance G1 between the track surface and the rolling element after the inner ring 4 is pressed in (G1=G0-(H0-H1)).

[0211] (The process of calculating the preload value of the first bearing)

[0212] The process is the same as that in the first embodiment, so the description is omitted.

[0213] (Sealing process)

[0214] The process is the same as that in the first embodiment, so the description is omitted.

[0215] (Measurement of rotational torque after pressing)

[0216] The process is the same as that in the first embodiment, so the description is omitted.

[0217] (Riveting process)

[0218] The process is the same as that in the first embodiment, so the description is omitted.

[0219] (Temperature measurement process)

[0220] A temperature measurement step (S48) is performed after the riveting process (S47). In the temperature measurement step (S48), the temperature ti0 of the riveted portion between the hub ring 3 and the inner ring 4 after the riveting process is completed is measured. Figure 17 As shown, in this embodiment, after the riveting process is completed, the temperature ti0 of the riveted portion 3h formed on the inner side end of the hub ring 3 is measured by the temperature sensor 15. The temperature ti0 of the riveted portion 3h can be measured immediately after the riveting process is completed, or after a certain period of time has elapsed since the riveting process was completed.

[0221] Temperature sensor 15 is installed, for example, in a riveting machine equipped with riveting punch 14. That is, the temperature ti0 of the riveting part 3h can be measured by temperature sensor 15 installed in the riveting machine. In this way, by using temperature sensor 15 installed in the riveting machine to measure the temperature ti0 of the riveting part 3h, the temperature ti0 of the riveting part 3h can be measured smoothly after the riveting process (S47) is performed.

[0222] As the temperature sensor 15, either a contact-type or a non-contact-type temperature sensor can be used. When the temperature sensor 15 is a contact-type temperature sensor, the temperature ti0 of the riveting part 3h can be directly measured while the contact of the temperature sensor 15 is in contact with the riveting part 3h. In this case, the contact of the temperature sensor 15 can be configured to rise and fall relative to the riveting part 3h. Specifically, the contact can be lowered and contacted with the riveting part 3h during the measurement of temperature ti0, and raised and removed from the riveting part 3h when the measurement of temperature ti0 ends. Alternatively, when the temperature sensor 15 is a non-contact-type temperature sensor, the temperature ti0 of the riveting part 3h can be measured while the temperature sensor 15 is positioned separately from the riveting part 3h.

[0223] In this embodiment, the temperature ti0 of the riveted portion 3h of the hub ring 3 is measured from the inner side in the axial direction, but the temperature of the inner side end face 4b of the inner ring 4 can also be measured. However, since the riveted portion 3h is located on the inner side in the axial direction than the inner side end face 4b, it is easier to measure the temperature ti0 of the riveted portion 3h than to measure the temperature of the inner side end face 4b.

[0224] (Riveting torque measurement process)

[0225] The process is the same as that in the first embodiment, so the description is omitted.

[0226] (Rotational torque correction process)

[0227] A rotational torque correction process (S50) is performed after the rotational torque measurement process (S39). In the rotational torque correction process (S50), the rotational torque Tb measured in the rotational torque measurement process (S49) after riveting is corrected based on the temperature ti0 of the riveted part 3h measured in the temperature measurement process (S08), and the corrected rotational torque Tc after riveting is calculated.

[0228] When the riveting process of riveting the small-diameter stepped portion 3a of the hub ring 3 to the inner ring 4 is performed, the riveting portion 3h in the small-diameter stepped portion 3a undergoes plastic deformation, resulting in a temperature rise. Furthermore, the heat from the riveting portion 3h in the small-diameter stepped portion 3a is transferred to the inner ring 4, causing the temperature of the inner ring 4 to rise. Because the inner ring 4 expands due to the temperature rise, the post-riveting rotational torque Tb measured in the post-riveting rotational torque measurement step (S49) is a larger value compared to the case where no temperature rise caused by the riveting process occurs.

[0229] Therefore, in the rotational torque correction process (S50), the post-riveting rotational torque Tb is corrected as follows, and the post-riveting rotational torque Tc is calculated when there is no temperature rise in the inner ring 4 caused by the riveting process. It should be noted that the temperature of the inner ring 4 when there is no temperature rise caused by the riveting process is the same as the ambient temperature around the wheel bearing assembly 1.

[0230] First, in the rotational torque correction process (S50), based on the temperature ti0 of the riveted part measured in the temperature measurement process (S48) over 3 hours, the following steps are taken: Figure 18 The temperature ti1 of the inner track surface 4a after riveting is calculated by relating the temperature of the riveted part 3h to the temperature of the inner track surface 4a of the inner ring 4. Here, it is possible to determine the temperature ti1 in advance through experiments, etc. Figure 18 The relationship between the temperature of the riveted part 3h and the temperature of the inner track surface 4a of the inner ring 4 is shown. Furthermore, the relationship between the temperature of the riveted part 3h and the temperature of the inner track surface 4a of the inner ring 4 can be determined according to the specifications of the wheel bearing assembly 1.

[0231] In the rotational torque correction process (S50), the change in rotational torque ΔT1 caused by the temperature change of the inner race 4 is further calculated based on the temperature difference Δt (Δt=ti1-t0) between the temperature ti1 of the inner race surface 4a after the riveting process and the temperature t0 of the inner race surface 4a before the riveting process, which is the same as the temperature of the inner race surface 4a before the riveting process. In this case, as Figure 19 As shown, the change in rotational torque ΔT1 is calculated as follows: the relationship between the temperature difference Δt and the change in rotational torque ΔT1 is determined beforehand through experiments, and the temperature difference Δt is substituted into this relationship. It should be noted that the relationship between the temperature difference Δt and the change in rotational torque ΔT1 can be determined according to the specifications of the wheel bearing device 1.

[0232] In reality, there is a time interval (s) between the riveting process and the measurement of the post-riveting rotational torque, and there is a temperature change. Therefore, to improve the accuracy of the post-riveting rotational torque Tb, the following method can also be used. For example... Figure 20 As shown, based on the elapsed time s from the time when the temperature ti0 of the riveted part was measured 3 hours after processing (the time of temperature measurement of the riveted part) to the time when the rotational torque Tb after riveting was measured (the time of measurement of the rotational torque after riveting), and the temperature ti1 of the inner track surface 4a after the riveting process is completed, the temperature ti2 of the inner track surface 4a at the time of measuring the rotational torque Tb after riveting is calculated using the relationship between the temperature and time of the inner track surface 4a of the inner ring 4. Here, it is possible to determine the temperature ti2 of the inner track surface 4a beforehand through experiments, etc. Figure 20 The temperature-time relationship of the inner track surface 4a is shown. Furthermore, the temperature-time relationship of the inner track surface 4a can be determined according to the specifications of the wheel bearing assembly 1.

[0233] exist Figure 20 In the temperature-time relationship of the inner track surface 4a shown, the temperature of the inner track surface 4a at the point when the temperature ti0 of the riveting part 3h is measured is ti1. Afterward, the temperature of the inner track surface 4a rises. This is because, after the temperature ti0 of the riveting part 3h is measured, the heat from the increased temperature of the riveting part 3h is transferred to the inner track surface 4a of the inner ring 4. Figure 20 In the process, the rotational torque Tb after riveting is measured at the moment when the temperature of the inner track surface 4a rises from ti1 and then drops slightly to ti2.

[0234] Thus, given the temperature ti2, the change in rotational torque ΔT1 can be calculated based on the temperature difference Δt between ti2 and the ambient temperature t0 (Δt = ti2 - t0).

[0235] After obtaining the change in rotational torque ΔT1, the corrected rotational torque Tc (Tc=Tb-ΔT1) is calculated by subtracting the change in rotational torque ΔT1 from the rotational torque Tb after riveting.

[0236] (The process of calculating the preload value of the second bearing)

[0237] After the rotational torque correction step (S50), a second bearing preload calculation step (S51) is performed. In the second bearing preload calculation step (S51), the difference torque ΔT2 (ΔT2=Tc-Ta) between the rotational torque Ta after pressing and the rotational torque Tc after riveting correction is calculated. Then, based on the difference torque ΔT2, the preload change ΔP between the pressing and riveting processes is calculated. Then, the second bearing preload value P2 is calculated by adding the preload change ΔP to the first bearing preload value P1 calculated in the first bearing preload calculation step (S44).

[0238] In this case, the differential torque ΔT2 is the increased rotational torque due to the riveting process performed in the riveting process (S47). Additionally, the preload change ΔP is the increased preload due to the riveting process performed in the riveting process (S47). Both the differential torque ΔT2 and the preload change ΔP are values ​​obtained after removing the effect of the temperature rise of the inner ring 4 caused by the riveting process.

[0239] like Figure 21 As shown, the preload change ΔP is calculated as follows: the relationship between the bearing preload and the bearing rotational torque of the wheel bearing assembly 1 is determined beforehand through experiments, and the difference torque ΔT2 is substituted into this relationship. It should be noted that the relationship between the bearing preload and the bearing rotational torque can be determined according to the specifications of the wheel bearing assembly 1.

[0240] In the second bearing preload calculation process (S51), the first bearing preload value P1 calculated based on the axial negative clearance G1 and the preload change ΔP calculated based on the rotational torque Ta after pressing and the rotational torque Tc after riveting are corrected are used to calculate the second bearing preload value P2. Therefore, the second bearing preload value P2 can be calculated with high accuracy.

[0241] (Judgment process)

[0242] Perform the same procedures as in the first implementation method.

[0243] In the second bearing preload calculation step (S51), based on the temperature ti0 of the riveted part measured 3h after the riveting process, the corrected rotational torque Tc after riveting, which excludes the effect of the temperature rise of the inner ring 4 caused by the riveting process, is calculated. This corrected rotational torque Tc is then used to calculate the second bearing preload value P2, thus enabling the calculation of the second bearing preload value P2 with high accuracy. Therefore, in the judgment step (S52), the effect of the temperature rise of the inner ring 4 caused by the riveting process can be considered, thereby allowing for a more accurate judgment of the quality of the preload applied to the wheel bearing assembly 1.

[0244] In particular, in the rotational torque correction process (S50), the temperature ti1 of the inner track surface 4a after riveting is completed is calculated based on the temperature ti0 of the riveting part 3h measured in the temperature measurement process (S48). The temperature ti2 of the inner track surface 4a when the rotational torque Tb after riveting is measured is calculated based on the elapsed time s from when the temperature ti of the riveting part 3h is measured to when the rotational torque Tb after riveting is measured, and the temperature ti1. The change in rotational torque ΔT1 caused by the temperature change of the inner ring 4 is calculated based on the temperature difference Δt between the temperature ti2 and the ambient temperature t0. The corrected rotational torque Tc after riveting is calculated by subtracting the change in rotational torque ΔT1 from the rotational torque Tb after riveting. Therefore, the corrected rotational torque Tc after riveting can be calculated easily and with high accuracy.

[0245] Furthermore, by calculating the corrected rotational torque Tc after riveting based on the temperature ti0 of the riveting section over 3 hours and the elapsed time s in the rotational torque correction process (S50), it is not necessary to wait for the temperature of the inner ring 4 to return to the temperature before riveting before measuring the rotational torque Tb after the riveting process (S47). Therefore, the quality of the preload applied to the wheel bearing assembly 1 can be determined in a mass production line without reducing production efficiency.

[0246] Furthermore, when calculating the preload using the rotational torque before and after riveting, if anomalies such as shape distortion of the inner raceway surface occur during riveting, the increase in rotational torque before and after riveting becomes larger, causing the calculated second bearing preload value P2 to deviate from the specified reference value range. Therefore, by judging the calculated second bearing preload value P2 in the judgment process (S52), it is possible to detect abnormalities that have occurred in the wheel bearing assembly 1 after riveting, thereby improving the reliability of the measured value of the preload applied to the wheel bearing assembly 1. Thus, the preload applied to the wheel bearing assembly 1 can be checked with higher reliability.

[0247] (Inner side sealing component assembly process)

[0248] The inner side sealing component assembly process (S53) is performed after the judgment process (S52). By performing the inner side sealing component assembly process (S53), the assembly process of the wheel bearing assembly 1 is completed. It should be noted that the inner side sealing component assembly process (S53) can be performed after the riveting rotational torque measurement process (S49), but it can be performed before the judgment process (S52), before the second bearing preload value calculation process (S51), or before the rotational torque correction process (S50). Figure 9 As shown, in the inner side sealing component assembly process (S53), the inner side sealing component 9 is fitted into the inner side opening 2a of the outer ring 2, thereby assembling the inner side sealing component 9 between the inner side end of the outer ring 2 and the inner side end of the inner ring 4.

[0249] If the inner square sealing member 9 is assembled before the riveting process (S47), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to factors such as the degree of riveting of the hub ring 3 in the riveting process (S47). Furthermore, even after the riveting process (S47), if the inner square sealing member 9 is assembled before the post-riveting rotational torque measurement process (S49), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to the assembly state of the inner square sealing member 9.

[0250] Therefore, if the inner side sealing member 9 is assembled before the riveting process (S47) or the riveting rotational torque measurement process (S49), it may affect the deviation of the riveting rotational torque Tb measured in the riveting rotational torque measurement process (S49). Similarly, if the inner side sealing member 9 is assembled before the pressing rotational torque measurement process (S46), the assembly state of the inner side sealing member 9 may affect the deviation of the pressing rotational torque Ta measured in the pressing rotational torque measurement process (S46).

[0251] However, in this embodiment, the inner side sealing member assembly process (S53) is performed after the riveting rotational torque measurement process (S49). Therefore, when measuring the riveting rotational torque Ta and riveting rotational torque Tb of the wheel bearing assembly 1 in the pressing rotational torque measurement process (S46) and the riveting rotational torque measurement process (S49), no deviation in rotational torque caused by the influence of the inner side sealing member 9 occurs, thereby enabling high-precision measurement of the rotational torque of the wheel bearing assembly 1.

[0252] In this embodiment, the inner side sealing member assembly process (S53) is performed after the riveting rotational torque measurement process (S49), but a structure in which the cover member assembly process is performed after the riveting rotational torque measurement process (S49) can also be adopted. In this case, in the cover member assembly process, the cover member replaces the inner side sealing member 9 and is fitted into the inner side opening 2a of the outer ring 2, and the inner side opening 2a is blocked by the cover member.

[0253] <Fifth Implementation>

[0254] like Figure 22 As shown, the pre-pressure inspection method of this embodiment includes a temporary pressing-in process (S61), a pressing-in process (S62), a first bearing pre-pressure value calculation process (S63), a sealing process (S64), a post-pressing rotational torque measurement process (S65), a riveting process (S66), a riveting workmanship measurement process (S67), a post-riveting rotational torque measurement process (S68), a second bearing pre-pressure value calculation process (S69), a first judgment process (S70), a second judgment process (S71), and an inner side sealing component assembly process (S72). The following describes each step of the pre-pressure inspection method.

[0255] (Temporary pressing process)

[0256] The process is the same as that in the first embodiment, so the description is omitted.

[0257] (Pressing process)

[0258] The process is the same as that in the first embodiment, so the description is omitted.

[0259] (The process of calculating the preload value of the first bearing)

[0260] The process is the same as that in the first embodiment, so the description is omitted.

[0261] (Sealing process)

[0262] The process is the same as that in the first embodiment, so the description is omitted.

[0263] (Measurement of rotational torque after pressing)

[0264] The process is the same as that in the first embodiment, so the description is omitted.

[0265] (Riveting process)

[0266] The process is the same as that in the first embodiment, so the description is omitted.

[0267] (Riveting process measurement procedure)

[0268] After the riveting process (S06), a riveting workability measurement process (S67) is performed. In the riveting workability measurement process (S67), the riveting workability of the riveted part formed by the riveting process is measured for 3h.

[0269] Here, the riveting workability refers to the degree of deformation of the riveted portion 3h that has undergone plastic deformation due to the riveting process, and can be represented by the shape of the riveted portion 3h. Furthermore, the shape of the riveted portion 3h, which is the object of measurement, includes the axial height h of the riveted portion 3h and the outer diameter r of the riveted portion 3h in the direction orthogonal to the axial direction. In other words, the riveting workability includes the axial height h of the riveted portion 3h and the outer diameter r of the riveted portion 3h in the direction orthogonal to the axial direction.

[0270] In this embodiment, the riveting degree of the riveting part 3h is measured by measuring the height dimension h and the outer diameter dimension r. However, the riveting degree of the riveting part 3h can also be measured by measuring only either the height dimension h or the outer diameter dimension r.

[0271] like Figure 23 As shown, the riveting degree of the riveting part 3h, i.e., the height dimension h and the outer diameter dimension r, can be measured, for example, using a measuring device 150. The measuring device 150 is a contact-type measuring device that makes a contact with the riveting part 3h to perform the measurement, and has a main body 151, a first contact 152 and a second contact 153.

[0272] The main body 151 is an elongated member extending in a direction orthogonal to the axial direction, supporting the first contact 152 so that it can move in a direction orthogonal to the axial direction.

[0273] The first contact 152 is an elongated member extending along the axial direction, and a pair is provided on the main body 151. When measuring the height dimension h and the outer diameter dimension r, the first contact 152 contacts the inner side end face 4b of the inner ring 4 and the outer diameter edge of the riveting part 3h in the direction orthogonal to the axial direction.

[0274] The second contact 153 is an elongated member extending in a direction orthogonal to the axial direction, supported by the first contact 152 so that it can move axially. When the height dimension h and the outer diameter dimension r are measured, the second contact 153 abuts against the inner side end face of the riveting part 3h in the axial direction.

[0275] When measuring the height dimension h of the riveting portion 3h using the measuring device 150 configured in this way, the second contact 153 is moved axially relative to the first contact 152, so that the front end of the first contact 152 abuts against the inner side end face 4b of the inner ring 4, and the second contact 153 contacts the inner side end face of the riveting portion 3h. Then, by measuring the axial length from the front end of the first contact 152 to the second contact 153, the axial dimension h of the riveting portion 3h from the inner side end face 4b to the inner side end face of the riveting portion 3h is measured.

[0276] Furthermore, when measuring the outer diameter r of the riveting portion 3h using the measuring device 150, the first contact 152 is moved relative to the main body 151 in a direction orthogonal to the axial direction, and the first contact 152 is brought into contact with the outer diameter edge of the riveting portion 3h. Then, the outer diameter r of the riveting portion 3h is measured by measuring the length between the first contacts 152 in the direction orthogonal to the axial direction.

[0277] It should be noted that in this embodiment, a measuring device 150 having a main body 151, a first contact 152, and a second contact 153 is used to measure the riveting degree of the riveting part 3h, but it is not limited to this. Other contact-type measuring devices with different structures can also be used to measure the riveting degree of the riveting part 3h. In this way, when using a contact-type measuring device to measure the riveting degree, it is easy to make the measuring device a simple structure.

[0278] Furthermore, the riveting workmanship of the riveting part 3h can also be measured using a non-contact measuring device that measures without contacting the riveting part 3h. For example, a non-contact measuring device could be... Figure 24 As shown, a laser displacement gauge can be used to measure the height h and other dimensions of the riveted part 3h by irradiating the riveted part 3h with a laser. Alternatively, the height h and outer diameter r of the riveted part 3h can be measured by photographing the riveted part 3h and processing the image. In this way, when measuring the riveting degree using a non-contact measuring device, the measurement can be performed without contact with the riveted part 3h, making it easy to measure the riveting degree in a manufacturing production line assembling wheel bearing devices 1.

[0279] (Riveting torque measurement process)

[0280] Perform the same procedures as in the first implementation method.

[0281] It should be noted that in this embodiment, the riveting workability measurement process (S68) is performed after the riveting workability measurement process (S67), but the riveting workability measurement process (S67) can also be performed after the riveting workability measurement process (S68).

[0282] (The process of calculating the preload value of the second bearing)

[0283] The process is the same as that in the first embodiment, so the description is omitted.

[0284] (First judgment process)

[0285] The first determination process (S70) is the same as the determination process (S09) in the first embodiment, so the description is omitted.

[0286] (Second judgment process)

[0287] A second judgment step (S71) is performed after the first judgment step (S70). In the second judgment step (S71), the riveting degree of the riveting part 3h is compared with the value of the differential torque ΔT. The presence or absence of riveting abnormality is determined based on whether the value of the differential torque ΔT relative to the riveting degree of the riveting part 3h is within the range of the torque reference value.

[0288] Specifically, such as Figure 25A As shown, a first relationship line X1, representing the relationship between the height dimension h of the riveted part 3h and the differential torque ΔT, is determined in advance through experiments, etc. Furthermore, the range between the upper limit X1U and the lower limit X1L of the differential torque ΔT relative to the height dimension h is pre-set as the range R1 of the first torque reference value for determining whether there is a riveting abnormality. Additionally, as... Figure 25B As shown, a second relationship line X2 representing the relationship between the outer diameter r of the riveted part 3h and the differential torque ΔT is obtained in advance through experiments, etc., and the range between the upper limit X2U and the lower limit X2L of the differential torque ΔT relative to the outer diameter r is set in advance as the range R2 of the second torque reference value for determining whether there is a riveting abnormality.

[0289] Then, the height dimension h and outer diameter dimension r of the riveted part 3h are compared with the value of the difference torque ΔT. Based on whether the value of the difference torque ΔT relative to the height dimension h is within the range R1 of the first torque reference value and whether the value of the difference torque ΔT relative to the outer diameter dimension r is within the range R2 of the second torque reference value, it is determined whether there is a riveting abnormality.

[0290] In this case, for example, when comparing the values ​​of the height dimension h and the outer diameter dimension r with the differential torque ΔT, if the value of the differential torque ΔT relative to the height dimension h is within the range R1 of the first torque reference value, and the value of the differential torque ΔT relative to the outer diameter dimension r is within the range R2 of the second torque reference value, it is determined that no riveting abnormality has occurred. Conversely, if when comparing the values ​​of the height dimension h and the outer diameter dimension r with the differential torque ΔT, if the value of the differential torque ΔT relative to the height dimension h is not within the range R1 of the first torque reference value, or if the value of the differential torque ΔT relative to the outer diameter dimension r is not within the range R2 of the second torque reference value, it is determined that a riveting abnormality has occurred.

[0291] In this way, by determining the presence or absence of riveting abnormalities based on the riveting workmanship degree, which is represented by the riveting shape, such as the height dimension h and outer diameter dimension r of the riveting part 3h, deformation of the inner track surface 4a of the inner ring 4, for example, originating from deviations in the shape of the riveting part 3h, can be detected. In this case, the determination of whether there is a riveting abnormality is by comparing the riveting workmanship degree of the riveting part 3h with the value of the differential torque ΔT. Therefore, in addition to detecting larger deformations of the inner track surface 4a by determining whether the preload is appropriate, smaller deformations of the inner track surface 4a can also be detected.

[0292] Furthermore, in this preload inspection method, the height dimension h and the outer diameter dimension r are used as the riveting workmanship to be measured. Since the height dimension h and the outer diameter dimension r are relatively easy to measure, the riveting workmanship can be measured in a way that does not reduce production efficiency in the mass production line.

[0293] In addition, in the second determination process (S71), based on the determination result of whether the pre-pressure is appropriate in the first determination process (S70) and the determination result of whether there is riveting abnormality in the second determination process (S71), it is determined whether the wheel bearing device 1 after riveting is a qualified product.

[0294] For example, if the preload of the wheel bearing assembly 1 is determined to be appropriate in the first judgment step (S70), and no riveting abnormality is determined to occur in the second judgment step (S71), the riveted wheel bearing assembly 1 is judged to be a qualified product. Conversely, if the preload of the wheel bearing assembly 1 is determined to be inappropriate in at least the first judgment step (S70), or a riveting abnormality is determined to occur in the second judgment step (S71), the riveted wheel bearing assembly 1 is judged to be a non-qualified product.

[0295] Thus, by implementing a second determination step (S71) based on the first determination step (S70), the determination of whether the preload is appropriate in the first determination step (S70) can be supplemented by the determination of whether there is a riveting abnormality in the second determination step (S71). As a result, the reliability of determining whether the preload applied to the wheel bearing assembly 1 is appropriate can be further improved, thereby manufacturing a higher quality wheel bearing assembly 1.

[0296] Furthermore, by measuring the riveting process details such as height h and outer diameter r in the pre-load inspection method, the shape of the riveted part 3h can be determined, and riveting conditions can be set based on the determined shape of the riveted part 3h, thereby adjusting the riveted part 3h to an appropriate shape. As a result, the shape of the riveted part 3h can be uniformized in multiple manufacturing sites and in each manufacturing batch, thereby enabling the manufacture of wheel bearing assemblies 1 with uniform quality.

[0297] It should be noted that in this embodiment, both the height dimension h and the outer diameter dimension r are measured as the riveting workability. However, it is also possible to measure only one of the height dimension h and the outer diameter dimension r as the riveting workability. In this way, by measuring only one of the height dimension h and the outer diameter dimension r, the reliability of determining whether the preload applied to the wheel bearing assembly 1 is appropriate can be further improved, thereby manufacturing a higher quality wheel bearing assembly 1.

[0298] However, compared to measuring only one of the height dimension h and the outer diameter dimension r, measuring both the height dimension h and the outer diameter dimension r allows for a more accurate determination of whether there is a riveting abnormality, and further improves the reliability of determining whether the preload is appropriate.

[0299] In addition, in this embodiment, after determining whether the pre-pressure is appropriate in the first determination step (S70), the determination of whether there is a riveting abnormality is performed in the second determination step (S71). However, it is also possible to determine whether the pre-pressure is appropriate in the second determination step (S71) after determining whether there is a riveting abnormality in the first determination step (S70).

[0300] (Inner side sealing component assembly process)

[0301] The inner side sealing component assembly process (S72) is performed after the second judgment process (S71). By performing the inner side sealing component assembly process (S72), the assembly process of the wheel bearing assembly 1 is completed. It should be noted that the inner side sealing component assembly process (S72) can be performed after the riveting rotational torque measurement process (S68), and can be performed before the second judgment process (S71), before the first judgment process (S70), or before the second bearing preload value calculation process (S69). Figure 9 As shown, in the inner side sealing component assembly process (S72), the inner side sealing component 9 is fitted into the inner side opening 2a of the outer ring 2, thereby assembling the inner side sealing component 9 between the inner side end of the outer ring 2 and the inner side end of the inner ring 4.

[0302] If the inner square sealing member 9 is assembled before the riveting process (S66), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to factors such as the degree of riveting of the hub ring 3 in the riveting process (S66). Furthermore, even after the riveting process (S66), if the inner square sealing member 9 is assembled before the post-riveting rotational torque measurement process (S68), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to the assembly state of the inner square sealing member 9.

[0303] Therefore, if the inner side sealing member 9 is assembled before the riveting process (S66) or the riveting rotational torque measurement process (S68), it may affect the deviation of the riveting rotational torque Tb measured in the riveting rotational torque measurement process (S68). Similarly, if the inner side sealing member 9 is assembled before the pressing rotational torque measurement process (S65), the assembly state of the inner side sealing member 9 may affect the deviation of the pressing rotational torque Ta measured in the pressing rotational torque measurement process (S65).

[0304] However, in this embodiment, the inner side sealing member assembly process (S72) is performed after the riveting rotational torque measurement process (S68). Therefore, when measuring the riveting rotational torque Ta and riveting rotational torque Tb of the wheel bearing assembly 1 in the pressing rotational torque measurement process (S65) and the riveting rotational torque measurement process (S68), no deviation in rotational torque caused by the influence of the inner side sealing member 9 occurs, thereby enabling high-precision measurement of the rotational torque of the wheel bearing assembly 1.

[0305] In this embodiment, the inner side sealing member assembly process (S72) is performed after the riveting rotational torque measurement process (S68), but a structure in which the cover member assembly process is performed after the riveting rotational torque measurement process (S68) can also be adopted. In this case, in the cover member assembly process, the cover member replaces the inner side sealing member 9 and is fitted into the inner side opening 2a of the outer ring 2, and the inner side opening 2a is blocked by the cover member.

[0306] <Sixth Implementation Method>

[0307] like Figure 26 As shown, the preload inspection method of this embodiment includes a temporary pressing-in process (S81), a pressing-in process (S82), a first inner ring height measurement process (S83), a first bearing preload value calculation process (S84), a sealing process (S85), a pressing-in rotational torque measurement process (S86), a riveting process (S87), a riveting-in temperature measurement process (S88), a second inner ring height measurement process (S89), a push-in change estimation process (S90), an inner ring push-in amount estimation process (S91), a final clearance calculation process (S92), a second bearing preload value calculation process (S93), a riveting-in rotational torque measurement process (S94), a torque increase estimation process (S95), a riveting-in rotational torque correction process (S96), a preload change estimation process (S97), a third bearing preload value calculation process (S98), a judgment process (S99), and an inner side sealing component assembly process (S100). The following describes each step of the preload inspection method.

[0308] (Temporary pressing process)

[0309] The process is the same as that in the first embodiment, so the description is omitted.

[0310] (Pressing process)

[0311] The pressing process (S82) is performed after the temporary pressing process (S81). Figure 4 As shown, in the pressing process (S82), the inner ring 4 is pressed into the small diameter step portion 3a until the outer side end face 4c of the inner ring 4 abuts against the shoulder portion 3e of the hub ring 3.

[0312] (First inner ring height measurement process)

[0313] The first inner ring height measurement process (S83) is performed after the pressing process (S82). Figure 4As shown, after the inner ring 4 is pressed into the small-diameter stepped portion 3a, the axial dimension between the outer end face 3g of the inner ring 4 and the inner end face 4b of the inner ring 4 after the inner ring 4 is pressed in is measured, which is the first inner ring height H1. Then, the value obtained by subtracting the first inner ring height H1 from the axial dimension H0 is subtracted from the axial positive clearance G0 between the track surface and the rolling element measured in the temporary pressing process (S81), thereby calculating the axial negative clearance G1 between the track surface and the rolling element after the inner ring 4 is pressed in (G1=G0-(H0-H1)).

[0314] (The process of calculating the preload value of the first bearing)

[0315] The process is the same as that in the first embodiment, so the description is omitted.

[0316] (Sealing process)

[0317] The process is the same as that in the first embodiment, so the description is omitted.

[0318] (Measurement of rotational torque after pressing)

[0319] The process is the same as that in the first embodiment, so the description is omitted.

[0320] (Riveting process)

[0321] The process is the same as that in the first embodiment, so the description is omitted.

[0322] (Temperature measurement process after riveting)

[0323] A post-riveting temperature measurement process (S88) is performed after the riveting process (S87). In the post-riveting temperature measurement process (S88), as follows... Figure 27 As shown, the temperature t1 of the riveting portion 3h-4d where the inner end of the small-diameter stepped portion 3a of the wheel hub 3 is riveted to the inner end face 4b of the inner ring 4 is measured. The temperature t1 is measured by a temperature measuring device 141.

[0324] For the temperature measurement of the riveted portion 3h-4d in the post-riveting temperature measurement process (S88), for example, it is preferable to install a temperature measuring device 141 for measuring the temperature of the riveted portion 3h-4d in advance on a part of the transfer device of the wheel bearing assembly 1 during the transfer assembly process, relative to the riveting device used for oscillating riveting. By adopting such a structure, the temperature can be efficiently measured during the transfer process from the riveting device to the next process after the riveting process of the wheel bearing assembly 1 is performed during assembly. As the temperature measuring device 141, both contact and non-contact temperature measuring devices can be used. It should be noted that the part where the temperature measurement is performed in the post-riveting temperature measurement process (S88) can be any part that can appropriately capture the effect of the temperature rise caused by the riveting process, such as the inner side end face 4b of the inner ring 4.

[0325] Then, after the temperature measurement process after riveting (S88), the second inner ring height measurement process (S89) and the rotational torque measurement process after riveting (S94) are performed. It should be noted that there is no restriction on the order in which the second inner ring height measurement process (S89) and the rotational torque measurement process after riveting (S94) are performed.

[0326] Here, we will first explain the series of steps (S89) to (S93) that follow the second inner ring height measurement step (S89). Each step (S89) to (S93) is a pre-pressure inspection method based on the so-called gap method.

[0327] (Second inner ring height measurement process)

[0328] A second inner ring height measurement process (S89) is performed after the post-riveting temperature measurement process (S88). In the second inner ring height measurement process (S89), as follows... Figure 27 As shown, the axial dimension between the outer end face 3g of the riveted hub ring 3 and the inner end face 4b of the inner ring 4, i.e., the second inner ring height H2, is measured. Then, the value obtained by subtracting the second inner ring height H2 from the first inner ring height H1 is calculated, i.e., the pushing amount D of the inner ring 4 (D=H1-H2). The pushing amount D of the inner ring 4 indicates the axial movement of the inner ring 4 from the completion of pressing in the inner ring 4 to the completion of riveting of the small diameter step portion 3a.

[0329] (Introducing the process for estimating changes)

[0330] After the second inner ring height measurement process (S89), a push-in change estimation process (S90) is performed. In the push-in change estimation process (S90), based on the temperature t1 of the riveting part 3h-4d, the change in the push-in amount D of the inner ring 4 caused by the temperature rise during riveting is estimated, namely, the push-in decrease ΔD. In the wheel bearing assembly 1 after riveting, the hub ring 3 and the inner ring 4 expand due to the temperature rise, so the push-in amount D of the inner ring 4 is smaller than that without the temperature rise. This smaller portion of the push-in amount D is the push-in decrease ΔD. The push-in decrease ΔD can be estimated, for example, by determining the relationship between the temperature t1 of the riveting part 3h-4d and the push-in decrease ΔD in advance through experiments, etc., and substituting the measured temperature t1 into this relationship. It should be noted that the relationship between the temperature t1 of the riveting part 3h-4d and the push-in decrease ΔD can be determined according to the specifications of the wheel bearing assembly 1.

[0331] (Estimation of inner ring insertion amount)

[0332] After the step of estimating the change in the amount of feed (S90), the step of estimating the amount of feed in the inner ring (S91) is performed. In the step of estimating the amount of feed in the inner ring (S91), the feed amount D of the inner ring 4 is corrected based on the decrease in feed amount ΔD, and the corrected feed amount D is estimated, which is the corrected feed amount Dh. (Dh=D+ΔD)

[0333] (Final gap calculation process)

[0334] After the inner ring insertion amount estimation process (S91), the final clearance calculation process (S92) is performed. In the final clearance calculation process (S92), the clearance reduction ΔG calculated by subtracting the corrected insertion amount Dh of the inner ring 4 from the axial negative clearance G1 before riveting, thereby calculating the final clearance G2 (G2=G1-ΔG). The clearance reduction ΔG can be estimated in the following way: the relationship between the insertion amount D and the clearance reduction ΔG is determined in advance through experiments, etc., and the measured corrected insertion amount Dh is substituted into this relationship. It should be noted that the relationship between the insertion amount D and the clearance reduction ΔG can be determined according to the specifications of the wheel bearing assembly 1.

[0335] (The process of calculating the preload value of the second bearing)

[0336] After the final clearance calculation step (S92), the second bearing preload calculation step (S93) is performed. In the second bearing preload calculation step (S93), based on the final clearance G2, the bearing preload value P2 to be applied to the riveted bearing is calculated using the clearance method. The bearing preload value P2 is calculated as follows: the relationship between the final clearance and the bearing preload value in the wheel bearing assembly 1 is determined in advance through experiments, etc., and the final clearance G2 is substituted into this relationship. It should be noted that the relationship between the final clearance and the bearing preload value can be determined according to the specifications of the wheel bearing assembly 1.

[0337] Next, the series of steps (S94) to (S98) following the step of measuring the rotational torque after riveting (S94) will be explained. Each step (S94) to (S98) is a preload inspection method based on the so-called torque method. It should be noted that the steps included in the series of steps (S89) to (S93) of the preload inspection method based on the gap method described above and the steps included in the series of steps (S94) to (S98) of the preload inspection method based on the torque method described below can be performed in parallel, regardless of the order of their implementation.

[0338] (Riveting torque measurement process)

[0339] After the post-riveting temperature measurement process (S88), a post-riveting rotational torque measurement process (S94) is performed. In the post-riveting rotational torque measurement process (S94), similar to the post-pressing rotational torque measurement process (S86), the rotational torque is measured under conditions where dynamic friction occurs between the inner members 3 and 4 and the outer member 2. In the post-riveting rotational torque measurement process (S94), the second rotational torque Tb is measured by the torque measuring device 13 when the hub ring rotates relative to the outer ring after the small-diameter stepped portion 3a is riveted to the inner ring 4. However, similar to the post-pressing rotational torque measurement process (S86), since the deviation of the measured rotational torque value is small when the rotational speed of the hub ring 3 changes, it is preferable to rotate the hub ring 3.

[0340] The post-riveting temperature measurement process (S88) is preferably performed just before the post-riveting rotational torque measurement process (S94), and the time between the post-riveting temperature measurement process (S88) and the post-riveting rotational torque measurement process (S94) is preferably shortened as much as possible. By shortening the time between the post-riveting temperature measurement process (S88) and the post-riveting rotational torque measurement process (S94), the temperature drop can be reduced, thereby improving the accuracy of calculating the third bearing preload value P3, which will be described later.

[0341] (Estimated torque increase process)

[0342] After the riveting rotational torque measurement step (S94), a torque increase estimation step (S95) is performed. In the torque increase estimation step (S95), the increase in the second rotational torque Tb caused by the temperature rise during the riveting process is estimated based on the temperature of the riveted part 3h-4d measured in the riveting temperature measurement step (S88).

[0343] In this case, such as Figure 28 As shown, the increase ΔTb is estimated as follows: the relationship between the temperature of the riveted part 3h-4d and the increase of the second rotational torque Tb is determined in advance through experiments, etc., and the temperature t1 of the riveted part 3h-4d is substituted into this relationship. It should be noted that the relationship between the temperature of the riveted part 3h-4d and the increase of the second rotational torque Tb can be determined according to the specifications of the wheel bearing device 1.

[0344] (Correction process for rotational torque after riveting)

[0345] After the torque increase estimation step (S95), a riveting rotational torque correction step (S96) is performed. In the riveting rotational torque correction step (S96), the second rotational torque Tb is corrected based on the increase ΔTb of the second rotational torque Tb estimated in the torque increase estimation step (S95). Specifically, the increase ΔTb is subtracted from the value of the second rotational torque Tb to calculate the corrected second rotational torque Tb, which is the third rotational torque Tc (Tc=Tb-ΔTb).

[0346] (Pre-compression variation estimation process)

[0347] After the riveting rotational torque correction process (S96), a preload change estimation process (S97) is performed. In the preload change estimation process (S97), the preload change is determined in advance through experiments, etc. Figure 15 The relationship between bearing preload and rotational torque (line R) is shown, and the first rotational torque Ta and the third rotational torque Tc are substituted into this relationship to calculate the difference torque ΔT. Then, in the preload change estimation step (S97), based on the calculated difference torque ΔT, the bearing preload is adjusted... Figure 15 The relationship shown is used to estimate the preload change ΔP caused by the riveting process.

[0348] In this case, such as Figure 15 As shown, the preload change ΔP is calculated as follows: the relationship between the bearing preload and the bearing rotational torque of the wheel bearing assembly 1 is determined beforehand through experiments, and the difference torque ΔT is substituted into this relationship. It should be noted that the relationship between the bearing preload and the bearing rotational torque can be determined according to the specifications of the wheel bearing assembly 1.

[0349] (The process of calculating the preload value of the third bearing)

[0350] After the preload change estimation step (S97), the third bearing preload value calculation step (S98) is performed. In the third bearing preload value calculation step (S98), the preload change ΔP is added to the first bearing preload value P1 to calculate the third bearing preload value P3.

[0351] (Judgment process)

[0352] After the second bearing preload calculation step (S93) and the third bearing preload calculation step (S98) are completed, a judgment step (S99) is performed. In the judgment step (S99), the appropriateness of the preload applied to the wheel bearing device 1 is determined based on three conditions: 1) whether the second bearing preload value P2 is within a specified threshold, 2) whether the third bearing preload value P3 is within a specified threshold, and 3) whether the relative difference between the second bearing preload value P2 and the third bearing preload value P3 is within a specified threshold.

[0353] In the preload inspection method of this embodiment, when calculating the second bearing preload value P2, the final clearance G3 is corrected by taking into account the temperature rise during riveting. Therefore, the second bearing preload value P2 can be calculated with high accuracy based on the clearance method, and the judgment accuracy based on the second bearing preload value P2 is improved in the judgment step (S99).

[0354] Furthermore, in the preload inspection method of this embodiment, when calculating the preload value P3 of the third bearing based on the rotational torque after pressing and the rotational torque after riveting, the preload change ΔP is corrected by considering the temperature rise during riveting. Therefore, the preload value P3 of the third bearing can be calculated with high accuracy based on the torque method, and the judgment accuracy based on the preload value P3 of the third bearing is improved in the judgment step (S99).

[0355] Furthermore, in the preload inspection method of this embodiment, the second bearing preload value P2 calculated by the so-called gap method and the third bearing preload value P3 calculated by the so-called torque method are compared to confirm whether the two are within a predetermined range of relative difference. This allows for more precise verification of the preload value applied to the bearing assembly 1 for the wheel. As a result, in the judgment step (S99), the appropriateness of the preload range of the wheel bearing assembly 1 can be verified with greater precision than in the past, thus ensuring a stable supply of wheel bearing assemblies 1 with guaranteed bearing life.

[0356] (Inner side sealing component assembly process)

[0357] After the judgment process (S99), the inner side sealing component assembly process (S100) is performed, thereby completing the assembly process of the wheel bearing assembly 1. That is, the inner side sealing component assembly process (S100) is part of the assembly method of the wheel bearing assembly 1. Figure 9 As shown, in the inner side sealing component assembly process (S100), the inner side sealing component 9 is fitted into the inner side opening 2a of the outer ring 2, thereby assembling the inner side sealing component 9 between the inner side end of the outer ring 2 and the inner side end of the inner ring 4.

[0358] If the inner square sealing member 9 is assembled before the riveting process (S87), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to factors such as the degree of riveting of the hub ring 3 in the riveting process (S87). Furthermore, even after the riveting process (S87), if the inner square sealing member 9 is assembled before the post-riveting rotational torque measurement process (S94), the sliding resistance between the outer ring 2 and the inner ring 4 of the inner square sealing member 9 will change due to the assembly state of the inner square sealing member 9.

[0359] Therefore, if the inner side sealing member 9 is assembled before the riveting process (S87) or the post-riveting rotational torque measurement process (S94), it may affect the deviation of the second rotational torque Tb measured in the post-riveting rotational torque measurement process (S94). Similarly, if the inner side sealing member 9 is assembled before the post-pressing rotational torque measurement process (S86), the assembly state of the inner side sealing member 9 may affect the deviation of the first rotational torque Ta measured in the post-pressing rotational torque measurement process (S86).

[0360] However, in this embodiment, the inner side sealing member assembly process (S100) is performed after the riveting rotational torque measurement process (S94). Therefore, when measuring the first rotational torque Ta and the second rotational torque Tb of the wheel bearing device 1 in the pressing-in rotational torque measurement process (S86) and the riveting rotational torque measurement process (S94), no deviation in rotational torque caused by the influence of the inner side sealing member 9 occurs, thereby enabling high-precision measurement of the rotational torque of the wheel bearing device 1.

[0361] (Temperature measurement procedure before riveting)

[0362] In the preload inspection method of wheel bearing assembly 1, such as Figure 29 As shown, it is preferable to perform a pre-riveting temperature measurement step (S101) before the riveting step (S87). In the pre-riveting temperature measurement step (S101), as follows: Figure 30As shown, the temperature t0 of the part corresponding to the riveting part 3h-4d before the inner side end of the small diameter stepped part 3a in the hub ring 3 is riveted to the inner side end face 4b of the inner ring 4 is measured.

[0363] exist Figure 2 In the preload inspection method for the wheel bearing assembly 1 shown, only the temperature t1 of the riveted portion 3h-4d after riveting is measured. In this case, the temperature of the portion of the wheel bearing assembly 1 before riveting corresponding to the riveted portion 3h-4d is equal to the ambient temperature (room temperature) of the wheel bearing assembly 1, and the temperature rise of the riveted portion 3h-4d after riveting is calculated. However, the ambient temperature of the wheel bearing assembly 1 varies due to differences in the installation environment of the inspection device (country, region, season, time, etc.).

[0364] On the other hand, if Figure 29 The preload inspection method for the wheel bearing assembly 1 shown is such that by employing a structure that accurately measures the temperature of the part corresponding to the riveted part 3h-4d before riveting and calculating the temperature rise of the riveted part 3h-4d after riveting, the accuracy of the preload inspection of the wheel bearing assembly 1 can be further improved.

[0365] In addition, such as Figure 31 As shown, the pre-riveting temperature measurement process (S101) is more preferably performed simultaneously with the first inner ring height measurement process (S83). This structure can be easily achieved by incorporating a temperature measuring device 141 as part of the measuring apparatus used to measure the first inner ring height H1 in the first inner ring height measurement process (S83). By employing this structure, for the wheel bearing assembly 1 during assembly, the temperature of the portion corresponding to the riveting part 3h-4d can be measured simultaneously with the measurement of the first inner ring height H1, thereby improving inspection accuracy and shortening a series of pre-pressure inspection steps. It should be noted that both contact and non-contact temperature measuring devices can be used.

[0366] And, as Figure 31 As shown, by performing a pre-riveting temperature measurement process (S101) before the sealing process (S85) and the post-pressing rotational torque measurement process (S86), the influence of temperature changes in the wheel bearing assembly 1 caused by the implementation of the sealing process (S85) or the post-pressing rotational torque measurement process (S86) can also be eliminated. Therefore, compared to the case where the pre-riveting temperature measurement process (S101) is performed after the sealing process (S85) and the post-pressing rotational torque measurement process (S86) (see...),... Figure 29 Compared to other methods, this method allows for a more accurate estimation of the bearing preload value.

[0367] And, as Figure 31As shown, the post-riveting temperature measurement process (S88) is preferably performed simultaneously with the second inner ring height measurement process (S89). As described above, by employing a structure in which the temperature measuring device 141 is installed as part of the measuring apparatus used to measure the first inner ring height H1 in the first inner ring height measurement process (S83), for the wheel bearing assembly 1 during assembly, the temperature of the riveted portion can be measured 3 hours to 4 days simultaneously with the measurement of the second inner ring height H2. This further shortens the series of pre-load checks.

[0368] It should be noted that the wheel bearing device 1 for the driven wheel has been described in each embodiment, but the preload inspection method of each embodiment can also be applied to the wheel bearing device for the drive wheel of the specification where the hub ring is riveted.

[0369] The embodiments of the present invention have been described above, but the present invention is not limited to any of the above embodiments, but is merely illustrative. Naturally, it can be implemented in various forms without departing from the spirit of the present invention. The scope of the present invention is shown by the content described in the technical solution, and also includes all changes within the scope and meaning of the content described in the technical solution.

[0370] Industrial applicability

[0371] This invention can be used in the preload inspection method for wheel bearing devices.

[0372] Explanation of reference numerals in the attached figures

[0373] 1. Wheel bearing assembly; 2. Outer ring; 2c (inner side) outer track surface; 2d (outer side) outer track surface; 3. Hub ring; 3a. Small diameter stepped section; 3c. Inner track surface; 4. Inner ring; 4a. Inner track surface; 5. Inner side ball bearing row; 6. Outer side ball bearing row; 7. Balls; 9. Inner side sealing component; P1. First bearing preload value; P2. Second bearing preload value; S02. Pressing process; S03. First bearing preload value calculation process; S04. Sealing process; S05. Pressing-in rotational torque measurement process; S06. Riveting process; S07. Riveting-in rotational torque measurement process; S08. Second bearing preload value calculation process; S09. Judgment process; Ta. Pressing-in rotational torque; Tb. Riveting-in rotational torque; ΔT. Differential torque; ΔP. Preload change.

Claims

1. A method for checking the preload of a wheel bearing assembly, wherein, The wheel bearing assembly includes: The outer component has two rows of outer track surfaces on its inner circumference; The inner component includes a hub ring having a small-diameter stepped portion extending axially on its outer periphery, and an inner ring pressed into the small-diameter stepped portion of the hub ring, and having a double-row inner track surface facing the double-row outer track surface; and A double-row rolling element, which is housed freely between the two track surfaces of the outer member and the inner member. The method for checking the preload of the wheel bearing assembly is characterized by the following: The preload inspection method for the wheel bearing assembly includes: In the pressing process, the inner ring is pressed axially into the position where it abuts against the hub ring relative to the small-diameter stepped portion of the hub ring. The first bearing preload value calculation process is to calculate the first bearing preload value of the wheel bearing device based on the axial negative clearance between the two track surfaces and the rolling element after the pressing process. The pressing-in rotational torque measurement process measures the pressing-in rotational torque of the wheel bearing device when the inner component and the outer component rotate relative to each other after the pressing-in process. In the riveting process, after the pressing-in rotational torque measurement process, the inner side end of the small-diameter stepped portion is riveted to the inner ring; The riveting rotation torque measurement process measures the riveting rotation torque of the wheel bearing device when the inner component and the outer component rotate relative to each other after the riveting process. The second bearing preload calculation process involves adding the preload change between the pressing and riveting processes (calculated based on the difference between the pressing-in and riveting rotational torques) to the first bearing preload value to calculate the second bearing preload value; and The determination process involves judging whether the preload applied to the wheel bearing device is appropriate based on whether the preload value of the second bearing is within the range of the reference value.

2. The preload inspection method for wheel bearing devices according to claim 1, wherein, The reference value is set taking into account the deviation of the rotational torque caused by riveting the small-diameter stepped portion to the inner ring.

3. The preload inspection method for wheel bearing devices according to claim 1, wherein, In the process of calculating the second bearing preload value, the relationship between the rotational torque corresponding to the ambient temperature and the preload is used, and the change in preload is calculated based on the difference torque.

4. The preload inspection method for wheel bearing devices according to claim 1, wherein, In the process of calculating the second bearing preload value, the relationship between the rotational torque corresponding to the surface temperature of the wheel bearing assembly and the preload is used, and the change in preload is calculated based on the difference torque.

5. The preload inspection method for wheel bearing devices according to claim 4, wherein, The surface temperature of the wheel bearing assembly is measured by a contact temperature sensor or a non-contact temperature sensor.

6. The method for checking the preload of a wheel bearing assembly according to claim 1, wherein, The preload inspection method for the wheel bearing assembly includes a rotational torque correction step between the post-riveting rotational torque measurement step and the second bearing preload value calculation step. In the rotational torque correction step, the post-riveting rotational torque is corrected based on the temperature rise of the inner ring caused by the riveting process, and the corrected post-riveting rotational torque is calculated. In the process of calculating the second bearing preload value, the preload change between the pressing process and the riveting process is calculated based on the difference between the rotational torque after pressing and the rotational torque after riveting correction. The preload change is then added to the first bearing preload value to calculate the second bearing preload value.

7. The preload inspection method for wheel bearing devices according to claim 6, wherein, In the riveting process, the time required for the riveting process is measured, i.e., the riveting processing time. In the rotational torque correction process, The increase in rotational torque after riveting, caused by the temperature rise of the inner ring due to the riveting process, is calculated based on the riveting time. The corrected riveting rotational torque is calculated by subtracting the increase in the riveting rotational torque from the riveting rotational torque.

8. The method for checking the preload of a wheel bearing assembly according to claim 7, wherein, In the rotational torque correction process, The increase in rotational torque after riveting is determined by using the relationship between the riveting processing time and the increase in rotational torque after riveting, which is obtained for multiple ambient temperatures, and the relationship between the riveting processing time and the increase in rotational torque after riveting corresponding to the ambient temperature during riveting.

9. The method for checking the preload of a wheel bearing assembly according to claim 7 or 8, wherein, The preload inspection method for the wheel bearing device also includes a processing time determination step. After the riveting process is completed, the processing time determination step determines whether the riveting processing time exceeds a specified upper limit value. If the riveting processing time exceeds the specified upper limit value, the wheel bearing device is discharged.

10. The method for checking the preload of a wheel bearing assembly according to claim 1, wherein, In the pressing-in rotational torque measurement process and the riveting-in rotational torque measurement process, the inner component and the outer component are rotated relative to each other at a speed of less than 60 rpm, and the rotational torque is measured.

11. The method for checking the preload of a wheel bearing assembly according to claim 1, wherein, Lubricating grease is filled between the wheel hub and the outer component. The preload inspection method for the wheel bearing device also includes a sealing process, which is performed at least between the pressing process and the post-pressing rotational torque measurement process. In this sealing process, the grease is sealed to the rolling element by rotating the inner component relative to the outer component.

12. The method for checking the preload of a wheel bearing assembly according to claim 1, wherein, The preload inspection method for the wheel bearing assembly includes: The temperature measurement process involves measuring the temperature of the riveted portion between the wheel hub and the inner ring after the riveting process is completed; and The rotational torque correction process corrects the post-riveting rotational torque based on the temperature of the riveted portion measured in the temperature measurement process, and calculates the corrected post-riveting rotational torque. In the process of calculating the second bearing preload value, the preload change between the pressing process and the riveting process is calculated based on the difference between the rotational torque after pressing and the rotational torque after riveting correction. The preload change is then added to the first bearing preload value to calculate the second bearing preload value.

13. The preload inspection method for wheel bearing devices according to claim 12, wherein, In the rotational torque correction process, Based on the temperature of the riveted portion measured in the temperature measurement process, and using the relationship between the temperature of the riveted portion and the temperature of the inner track surface of the inner ring, the temperature of the inner track surface of the inner ring after the riveting process is completed is calculated. Based on the elapsed time from when the temperature of the riveted part is measured to when the rotational torque after riveting is measured, and the temperature of the inner track surface of the inner ring after the riveting process is completed, the temperature of the inner track surface of the inner ring at the time of measuring the rotational torque after riveting is calculated using the relationship between the temperature of the inner track surface of the inner ring and time. Based on the temperature difference between the inner track surface of the inner ring and the ambient temperature when the rotational torque after riveting is measured, the change in rotational torque caused by the temperature change is calculated. The corrected riveting torque is calculated by subtracting the change in rotational torque from the riveting torque.

14. The method for checking the preload of a wheel bearing assembly according to claim 12 or 13, wherein, In the temperature measurement process, The temperature of the riveted part is measured by a temperature sensor installed on the riveting machine that performs the riveting process.

15. The preload inspection method for wheel bearing devices according to claim 14, wherein, The temperature sensor is either a contact temperature sensor or a non-contact temperature sensor.

16. The method for checking the preload of a wheel bearing assembly according to claim 1, wherein, The preload inspection method for the wheel bearing device includes a riveting workability measurement step for measuring the riveting workability of the riveted portion formed in the small-diameter step portion during the riveting process. The determination process includes: The first determination step involves determining whether the preload applied to the wheel bearing assembly is appropriate based on whether the second bearing preload value is within the range of the reference value; and The second determination process involves comparing the riveting work degree with the value of the differential torque, and determining whether there is a riveting abnormality based on whether the value of the differential torque relative to the riveting work degree is within the range of the torque reference value.

17. The method for checking the preload of a wheel bearing assembly according to claim 16, wherein, The riveting process includes at least one of the axial height dimension of the riveted portion and the outer diameter dimension of the riveted portion in a direction orthogonal to the axial direction.

18. The method for checking the preload of a wheel bearing assembly according to claim 16 or 17, wherein, In the riveting workmanship measurement process... The riveting workmanship is measured by a contact-type measuring instrument that makes a contact point come into contact with the riveting part.

19. The method for checking the preload of a wheel bearing assembly according to claim 16 or 17, wherein, In the riveting workmanship measurement process... The riveting workmanship is measured by a non-contact measuring instrument that does not contact the riveted part.

20. A method for checking the preload of a wheel bearing assembly, wherein, The wheel bearing assembly includes: The outer component has two rows of outer track surfaces on its inner circumference; The inner component includes a hub ring having a small-diameter stepped portion extending axially on its outer periphery, and an inner ring pressed into the small-diameter stepped portion of the hub ring, and having a double-row inner track surface facing the double-row outer track surface; and A double-row rolling element, which is housed freely between the two track surfaces of the outer member and the inner member. The method for checking the preload of the wheel bearing assembly is characterized by the following: The preload inspection method for the wheel bearing assembly includes: In the pressing process, the inner ring is pressed axially into the position where it abuts against the hub ring relative to the small-diameter stepped portion of the hub ring. The first inner ring height measurement process measures the height of the first inner ring from the outer end of the wheel hub ring to the inner end of the inner ring after the pressing process. In the first bearing preload calculation process, the axial negative clearance between the two track surfaces and the rolling element after the pressing process is measured, and the bearing preload value of the wheel bearing device is calculated based on the axial negative clearance. The pressing-in rotational torque measurement process measures the pressing-in rotational torque of the wheel bearing device when the inner component and the outer component rotate relative to each other after the pressing-in process. In the riveting process, after the first inner ring height measurement process and the pressing-in rotational torque measurement process, the inner side end of the small diameter step portion is riveted to the inner ring. The temperature measurement process after riveting involves measuring the temperature of the riveted portion between the small-diameter stepped part and the inner ring after the riveting process. The second inner ring height measurement process measures the height of the second inner ring from the outer end of the wheel hub ring to the inner end of the inner ring after the riveting process. The inner ring insertion amount estimation process calculates the insertion amount of the inner ring by the difference between the height of the first inner ring and the height of the second inner ring, and corrects the insertion amount of the inner ring based on the temperature of the riveting part, thereby estimating the corrected insertion amount of the inner ring relative to the wheel hub ring. The final clearance calculation process involves calculating the reduction in clearance between the two track surfaces and the rolling element based on the estimated, corrected push-in amount of the inner ring, and then calculating the final clearance between the inner ring and the hub ring based on the reduction in clearance and the axial negative clearance. The second bearing preload value calculation process involves calculating the second bearing preload value of the wheel bearing assembly based on the calculated final clearance. The riveting rotation torque measurement process measures the riveting rotation torque of the wheel bearing device when the inner component and the outer component rotate relative to each other after the riveting process. The riveting rotation torque correction process involves estimating the torque increase caused by temperature change in the riveted rotation torque based on the temperature of the riveted part after the riveting process, and subtracting the torque increase from the riveted rotation torque to correct the riveting rotation torque. The preload change estimation process calculates the difference torque between the rotational torque after pressing and the corrected rotational torque after riveting, and estimates the preload change caused by the riveting process based on the difference torque. The process of calculating the preload value of the third bearing involves adding the preload change to the preload value of the first bearing to calculate the preload value of the third bearing; and The determination process involves judging whether the preload applied to the wheel bearing device is appropriate based on whether the preload values ​​of the second and third bearings are within a specified threshold, and whether the relative difference between the preload values ​​of the second and third bearings is within a specified threshold.

21. The method for checking the preload of a wheel bearing assembly according to claim 20, wherein, The temperature of the riveting part is set to the temperature of the inner ring constituting the riveting part.

22. The method for checking the preload of a wheel bearing assembly according to claim 20 or 21, wherein, The preload inspection method for the wheel bearing device also includes a pre-riveting temperature measurement step for measuring the temperature of the riveted part before the riveting process. Calculate the temperature change of the part corresponding to the riveting part before the riveting process and the temperature of the riveting part after the riveting process. The temperature change is used as the temperature of the riveted part in the inner ring insertion estimation process and the torque increase estimation process.

23. The method for checking the preload of a wheel bearing assembly according to claim 22, wherein, The pre-riveting temperature measurement process is performed simultaneously during the first inner ring height measurement process.

24. The method for checking the preload of a wheel bearing assembly according to claim 20, wherein, The post-riveting temperature measurement process is performed simultaneously during the second inner ring height measurement process.

25. The method for checking the preload of a wheel bearing assembly according to claim 20, wherein, The post-riveting temperature measurement process is performed before the post-riveting rotational torque measurement process.

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