JP2006144868A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device of simple structure reduced in assembling man-hours and capable of detecting a load in three axial directions crossing each other. <P>SOLUTION: This bearing device has an outer ring member 23 as a fixed side, an inside rotating member 10 as a movable side, and two lines of rolling elements 3 and 3. Vibration sensors 5 and 6 respectively formed of an AE sensor are arranged at positions corresponding to each of the two lines of the rolling elements 3 and 3 on a peripheral side of the outer ring member 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheel bearing device (hereinafter also simply referred to as a bearing device) capable of detecting the direction of an acting load.

  In recent years, various types of information are required to perform control such as driving and braking of automobiles, and in order to obtain such information, it has been proposed to provide a sensor in a wheel bearing device. The bearing device includes a wheel-side track member to which a wheel is attached, a vehicle-side track member fixed to the vehicle body side, and a rolling element disposed between the both track members. As shown in FIG. 1, there is one that obtains information on a load acting on a bearing device by attaching a strain gauge to a flange portion of a wheel side raceway member.

In addition, there is a device that obtains a relative displacement between a vehicle body side track member and a wheel side track member by a displacement sensor and measures an acting load. For example, in Patent Document 2, a displacement sensor is inserted into a through-hole formed in an outer ring member, and the displacement of an inner wheel side track member is detected by a displacement sensor between two rows of rolling elements.
Japanese Patent Laying-Open No. 2003-246201 (FIG. 1) Japanese Patent Laying-Open No. 2004-45219 (FIG. 1)

  However, the configuration described in Patent Document 1 has a problem that the direction of the acting load cannot be accurately detected because the strain gauge is provided on the rotating wheel side raceway member. . In particular, a load in the direction in which the axis of the vehicle body side race member (outer ring) and the axis of the wheel side race member (inner ring) are inclined (torsion) (load in the Y axis direction: turning force) cannot be detected.

  Further, in the configuration described in Patent Document 2, in order to use a displacement sensor, it is necessary to form a through hole in the outer ring member, and additionally provide a detected member on the inner rotating member, which increases the number of parts. However, the structure becomes complicated. In particular, there is a problem that the mounting accuracy of the displacement sensor and the mounting accuracy of the detected member are required to be high. In addition, since the displacement sensor performs measurement between two rows of rolling elements, there is a problem in that a load in a direction in which the axis of the vehicle body side track member and the axis of the wheel side track member are inclined cannot be detected with high accuracy.

  The present invention has been made in view of the above problems, and provides a bearing device that is simple in structure and capable of reducing the number of assembling steps and that can detect loads in three orthogonal axes. The purpose is to do.

  In order to achieve the above object, a wheel bearing device of the present invention includes an outer ring member that is a fixed side, an inner rotating member that is a movable side, and an outer ring member that is disposed between the outer ring member and the inner rotating member. A bearing device for a wheel having rolling elements in a row, wherein a vibration sensor is provided in a state where the vibration sensor is arranged at a position corresponding to each row of the rolling elements on the outer peripheral side of the outer ring member. . According to the bearing device having such a configuration, since only the vibration sensor is provided on the outer peripheral side of the outer ring member, there is no need to separately drill holes in the bearing device body, the structure is simplified, and the assembly man-hours are reduced. Can be reduced. Therefore, the present invention can also be applied to existing bearing devices. Further, it is possible to accurately detect the load in the direction in which the axis of the outer ring member and the axis of the inner rotating member are inclined (load in the Y-axis direction serving as the axis direction).

  Further, the vibration sensor is an AE sensor that detects a contact state between the rolling element and the raceway for the rolling element as an AE signal, and the two vibration sensors provided side by side are the outer ring member. It is preferable to be provided at the top of the outer peripheral side. According to this configuration, unlike the pressure sensor, it is not necessary to adjust the preload. In addition, since the pattern (form) of the contact state in the two rows of rolling elements is different due to the load acting, this is detected as an AE signal in each rolling element, and due to the difference in the output pattern of the two AE sensors, The load in the Y-axis direction and the load in the Z-axis direction orthogonal to the Y-axis can be accurately detected.

  Further, it is preferable that the two vibration sensors provided side by side are further provided on the outer peripheral side of the outer ring member. With this configuration, the load in the X-axis direction that is the front-rear horizontal direction of the bearing device is preferably provided. Can be accurately detected, and the load in the three orthogonal axes (XYZ) can be detected with high accuracy.

  According to the wheel bearing device of the present invention, the vibration sensor can be externally installed on the outer ring member in an exposed state, and there is no need to separately drill holes in the bearing device body. This simplifies and reduces the assembly man-hours. In addition, the present invention can be applied to an existing bearing device, and can detect a load in three orthogonal directions.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing a bearing device according to an embodiment of the present invention. This bearing device is disposed between a vehicle body side track member 1 fixed to a vehicle body (not shown), a wheel side track member 2 to which a wheel (not shown) is attached, and the track members 1 and 2. Two rows of rolling elements 3a and 3b are provided. Note that the bearing device is not limited to the illustrated form, and may be of other forms within the scope of the present invention.

  The wheel-side track member 2 has a shaft-shaped hub 4 to which a wheel (wheel) (not shown) is attached, and an inner ring member 16 fitted to the outer peripheral surface on one end portion side of the hub 4. The hub 4 and the inner ring member 16 constitute an inner rotating member 10. The hub 4 is formed with a radially outer flange portion 11 on the other end side, and a bolt 7 for attaching a wheel is attached to the flange portion 11. A first inner ring raceway 24a is formed on the outer peripheral surface of the hub 4, and a second inner ring raceway 24b is formed on the inner ring member 16 externally fitted to the hub 4 to form two rows of inner ring raceways. ing.

  The vehicle body-side track member 1 has an outer ring member 20 that constitutes an outer ring of a bearing. The outer ring member 20 includes a cylindrical portion 22 in which outer ring raceways 23 a and 23 b are formed on an inner peripheral surface, and an outer periphery of the cylindrical portion 22. A fixed-side member (not shown) formed on the surface and a radially outward flange portion 21 to be fixed are provided. That is, the outer ring member 20 is a fixed side in the bearing device, and the inner rotating member 10 is a movable side. A first outer ring raceway 23a and a second outer ring raceway 23b are formed in two rows on the inner peripheral surface of the cylindrical portion 22 so as to correspond to the first inner ring raceway 24a and the second inner ring raceway 24b, respectively. Yes. The flange portion 21 is provided on the outer peripheral surface side of the cylindrical portion 22 corresponding to the intermediate position in the axial direction between the first outer ring raceway 23a and the second outer ring raceway 23b.

And the vibration sensors 5 and 6 are provided in the state corresponding to each row | line | column of the rolling elements 3a and 3b in the outer peripheral side of the cylinder part 22 of the outer ring member 20, so that it may become a parallel state. . That is, the two vibration sensors 5 and 6 are arranged on the outer peripheral side of the cylindrical portion 22 of the outer ring member 20 side by side in a direction parallel to the Y-axis direction that is the axial direction.
Note that “the outer peripheral side of the cylindrical portion 22” means that the vibration sensors 5 and 6 are provided so as to be in contact with the outer peripheral surface of the cylindrical portion 22. The case where the tip portions of the vibration sensors 5 and 6 are embedded in the concave portion is also included.

The vibration sensors 5 and 6 are in contact between the rolling elements 3a and 3b and the rolling element raceway, that is, the outer ring raceways 23a and 23b of the outer ring member 20 and the inner ring raceways 24a and 24b of the inner rotating member 10. Can be used as an AE sensor. In this case, each of these two vibration sensors 5 and 6 detects the behavior of the radially inward rolling elements 3a and 3b as an AE signal. By using two vibration sensors 5 and 6 as a set, the behavior of the two rows of rolling elements 3a and 3b that occur when a load is applied to the bearing device from a certain direction as described later is different. The direction of the load can be detected by the difference in pattern. That is, the outputs of the sensors 5 and 6 corresponding to the change in the contact state of the rolling elements 3a and 3b that occur when a load is applied are different between the two vibration sensors 5 and 6, as shown in FIG. In the case of (opposite) or when the two vibration sensors 5 and 6 are the same at the same time as shown in FIG. .

  As shown in the cross-sectional view of FIG. 3, the two vibration sensors 5 and 6 that are provided side by side are provided on the top portion 22 a on the outer peripheral side of the cylindrical portion 22 of the vehicle body side track member 1. That is, the set of vibration sensors 5 and 6 is arranged on the vertical plane including the Y axis and the Z axis with the radially inner side of the bearing device as the detection direction. The contact state of the rolling elements 3a and 3b below the vibration sensors 5 and 6 is detected by a pair of vibration sensors 5 and 6 on the top portion 22a, and the X-axis direction, the Y-axis direction, and the Z-axis direction are detected. Can be detected.

  Further, in the embodiment shown in FIG. 3, two vibration sensors 5 and 6 provided side by side are further provided on the side portion 22 b on the outer peripheral side of the cylindrical portion 22 of the vehicle body side track member 1. The second set of vibration sensors 5 and 6 provided on the side portion 22b is disposed on the horizontal plane including the Y axis and the X axis with the radially inner side of the bearing device as the detection direction. The contact state of the rolling elements 3a and 3b on the lateral inner sides of the vibration sensors 5 and 6 is detected by the pair of vibration sensors 5 and 6 on the side portion 22b, and the load in the X-axis direction is detected more accurately. it can.

  Here, the Y axis serving as the axis, and the X axis and the Z axis orthogonal to the Y axis will be described. In the case of a wheel bearing device, the Y axis direction, which is the axial direction of the bearing device, is left and right (left and right horizontal) Direction, the X-axis direction is the front-rear (front-rear horizontal) direction, and the Z-axis direction is the height direction (vertical direction).

Next, a load detection method using the vibration sensors 5 and 6 will be described with reference to FIGS. 4 is a design center line of the rolling elements 3a and 3b (balls 17). In a wheel bearing device, as indicated by an arrow A in FIG. 1, when a load is applied in the Y-axis direction, a force point exists near the road surface on which the automobile travels. A load in the Y-axis direction (twisting direction as indicated by arrow R in FIG. 1) or the Z-axis direction acts to cause an inclination between the axis of the side track member 1 and the axis of the wheel-side track member 2.
When a load in the Y-axis direction that is the direction of the arrow R is applied, the rolling elements 3a and 3b that are present at the top of the bearing device (to be detected by the vibration sensors 5 and 6 of the top portion 22a) are indicated by an arrow a in FIG. As shown in FIG. 1, a force in a direction away from the outer ring raceway 23 a acts on the rolling element 3 a on the wheel side, and on the other hand, as indicated by an arrow b in FIG. The force that presses the outer ring raceway 23b) acts. Accordingly, the contact situation between the two rows of rolling elements 3a, 3b is a model as shown in FIG. 4 (a), and the mutual contact situation differs. As a result, the first sensor 5 and the second sensor 6 emit outputs in opposite directions as shown in FIG. That is, when such an output is obtained by the set of vibration sensors 5 and 6 provided on the top portion 22a, it can be detected that a load in the Y-axis direction is applied.

Further, when a positive load parallel to the Z-axis direction (load in the direction of arrow B in FIG. 1) is applied, the two rows of rolling elements 3a and 3b existing on the upper part both receive a compressive force, and FIG. As shown in FIG. 2 (b), the first sensor 5 and the second sensor 6 emit outputs of the same magnitude in the same direction. The output value increases greatly). That is, when such an output is obtained by the pair of vibration sensors 5 and 6 provided on the top portion 22a, it can be detected that a positive load is applied in the Z-axis direction.
If a negative load parallel to the Z-axis direction (a load in the direction opposite to the arrow B in FIG. 1) is applied, the model shown in FIG. 4 (c) is reversed and the rolling elements 3a and 3b contact each other. The situation is the same, and the first sensor 5 and the second sensor 6 emit the same magnitude of output in the same direction, but the output value appears to decrease (than the initial state). From this result, it can be detected that a negative load is applied in the Z-axis direction.
Further, in the pair of vibration sensors 5 and 6 provided on the side portion 22b of the cylindrical portion 22 of the vehicle body side track member 1, the load in the X-axis direction is detected by the increase / decrease of the output value by the same action as described above. be able to. In this way, it is possible to detect loads in three orthogonal directions.

Table 1 shows the relationship between the output patterns of the two vibration sensors 5 and 6 and the direction of the applied load. Table 1 shows a case where a set of vibration sensors 5 and 6 are provided only on the top portion 22a of the vehicle body side raceway member 1, and Table 2 shows a set of vibration sensors on the side portion 22b in addition to the top portion 22a. The case where 5 and 6 are provided is shown.
In Table 1, the load of the X-axis direction can be detected, as shown in Table 1, although the vibration sensors 5 and 6 on the side portion 22b are not provided. This is because the pattern is different from the case where a load is applied in each axial direction, and the load in the X-axis direction can be detected by a relative output. That is, the two vibration sensors 5 and 6 both generate a medium output that is smaller than when a load is applied in the Z-axis direction, and both output an output in the same direction, so that the load is applied in the X-axis direction. Detecting that it has acted. Note that this detection does not detect even the direction of force (positive and negative directions), but can detect that a load in the X-axis direction is applied.

1 is a longitudinal sectional view showing a bearing device according to an embodiment of the present invention. It is explanatory drawing which shows the output obtained by two vibration sensors. It is a cross-sectional view of the bearing device of the present invention. It is a model figure of a rolling element when the load of each axial direction acts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body side track member 2 Wheel side track member 3 Rolling element 5 Vibration sensor 6 Vibration sensor 10 Inner rotating member 20 Outer ring member 22 Tube part 22a Top part 22b Side part 23a Outer ring track 23b Outer ring track 24a Inner ring track 24b Inner ring track

Claims (3)

  A wheel bearing device having an outer ring member serving as a fixed side, an inner rotating member serving as a movable side, and two rows of rolling elements disposed between the outer ring member and the inner rotating member, A wheel bearing device, characterized in that a vibration sensor is provided in a state of being arranged on the outer peripheral side of the outer ring member and corresponding to each row of the rolling elements.   The vibration sensor is an AE sensor that detects a contact state between the rolling element and the raceway for the rolling element as an AE signal, and the two vibration sensors that are provided side by side are an outer periphery of the outer ring member. The wheel bearing device according to claim 1, wherein the wheel bearing device is provided at the top of the side.   The wheel bearing device according to claim 2, wherein two vibration sensors provided side by side are further provided on a side portion on an outer peripheral side of the outer ring member.

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