JP2005076700A - Hub unit with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hub unit with a sensor capable of properly adjusting a sensor mounting position by specifying a part where the reverse magnetostrictive effect or the displacement in the hub unit is increased in mounting the sensor, to determine the tire grounding load with high accuracy by using the sensor, and further to take and determine only the tire grounding load in the lateral direction. <P>SOLUTION: This hub unit with the sensor comprises a hub unit 1 having a car body-side track member 3, a wheel-side track member 4 and two-row rolling elements 5, and a sensor device 2. The sensor device 2 has a magnetostrictive sensor 8 detecting the reverse magnetostrictive effect, and the magnetostrictive sensor 8 is mounted on the car body-side track member 3 to measure the tensile distortion at an uppermost part of an inner ring 17 of the wheel-side track member 4. The lateral tire grounding load can be detected on the basis of the output of the magnetostrictive sensor 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sensor-equipped hub unit in which a hub unit constituting an automobile and a sensor device for detecting various information of the automobile are integrated.

  In automobiles, various information is necessary to perform the control. Therefore, a vehicle body side track member fixed to the vehicle body side, a wheel side track member to which a wheel is attached, and two members disposed between both members. It has been proposed to provide a sensor device in a hub unit having a row of rolling elements. For example, Patent Document 1 discloses a sensor-equipped hub unit in which an annular support member is attached to an inner end surface of a vehicle body side track member, and a strain sensor is attached to the annular support member.

  In recent years, in addition to ABS control (anti-lock brake system), driving force control that does not spin the driving wheel when starting or accelerating, and braking force control that suppresses side slip during cornering have been implemented as a vehicle control means. However, in order to perform more accurate control, it is important to detect data that can be used effectively for these controls. In view of such circumstances, the present inventors have created a problem of measuring the ground load applied to the tire (wheel) with high accuracy to improve vehicle control.

On the other hand, the sensor-equipped hub unit of Patent Document 1 measures the strain of the annular support member. Therefore, when obtaining the tire ground contact load from this strain, an error increases, and the accuracy is determined from the measured value of the strain sensor. There was a problem that the tire contact load could not be obtained well. Therefore, the present inventor has proposed that the tire ground contact load is accurately obtained using a magnetostrictive sensor (Patent Document 2).
Japanese Patent Laid-Open No. 3-209016 Japanese Patent Application No. 2002-142417

  According to the hub unit with a sensor of the above-mentioned patent document 2, when the location where the magnetostrictive sensor is attached is appropriate, the expected effect can be obtained, but when the location where the magnetostrictive sensor is attached is inappropriate, the detection is reversed. The magnetostrictive effect is reduced, and as a result, an error in the obtained tire ground contact load may be increased. Moreover, as data suitable for vehicle control, it is desired to extract only the left and right direction component of the tire ground contact load. However, if the location where the magnetostrictive sensor is attached is inappropriate, the right and left tire contact load is accurately calculated. There was also a problem that it could not be requested.

  The object of the present invention is to optimize the mounting position of the sensor by identifying the location where the inverse magnetostriction effect or displacement amount in the hub unit is large when mounting the sensor (including not only the magnetostrictive sensor but also the displacement sensor), Accordingly, it is an object of the present invention to provide a sensor-equipped hub unit that allows a tire ground contact load to be obtained with high accuracy using a sensor and that allows only the right and left tire contact load to be obtained and obtained.

  A hub unit with a sensor according to a first invention includes a vehicle body side track member fixed to the vehicle body side, an inner shaft having a wheel mounting flange, and a wheel side track member to which a wheel is mounted having an inner ring fitted on the inner shaft. In addition, a sensor-equipped hub unit including a hub unit having two rows of rolling elements disposed between both raceway members and a sensor device, the sensor device includes a magnetostrictive sensor that detects an inverse magnetostrictive effect. The magnetostrictive sensor is attached to the vehicle body side track member so as to be able to measure either the tensile strain at the uppermost part of the inner ring or the compressive strain at the lowermost part of the vehicle body side track member. The ground load is detected.

  A magnetostrictive sensor is a sensor that measures the inverse magnetostrictive effect (a phenomenon in which a magnetic force appears when a material is distorted or deformed). For example, the magnetostrictive sensor can be configured such that both ends of a magnetic wire when a high-frequency current is applied to a magnetic wire with high permeability Examples thereof include a magnetic impedance sensor (MI sensor) that measures an external magnetic field using an electromagnetic phenomenon in which the impedance changes depending on the external magnetic field, and a stress impedance sensor (SI sensor) that uses a change in impedance due to stress.

  The ground load applied to each tire fluctuates with changes in the speed and posture of the traveling vehicle. At this time, the force that the rolling element exerts on the wheel side track member and the vehicle body side track member changes according to the tire ground load. To do. This change in force appears as a strain fluctuation amount of the wheel side raceway member and the vehicle body side raceway member in the vicinity of the rolling elements, and the fluctuation amount of the tire ground contact load is obtained by detecting the strain fluctuation amount by a magnetostrictive sensor and calculating back. be able to.

  When a ground load acts on the tire, compression or tension distortion occurs in each part of the hub unit. Usually, the vertical line passing through the center between the two rows of rolling elements of the hub unit is axially outer than the vertical line passing through the center of the tire, and has a wheel-side track member including an inner shaft and an inner ring. In the unit, a relatively large distortion occurs in the inner ring near the vehicle body. The distortion of the inner ring is the strain in the pulling direction that becomes the maximum at the uppermost portion on the opposite side of the ground contact center. Therefore, a larger inverse magnetostriction effect can be detected by arranging the magnetostrictive sensor so as to detect the tensile strain of the inner ring. Moreover, the output of the magnetostrictive sensor obtained by detecting the strain in the tensile direction has a very high correlation with the left and right tire contact load, and therefore, a relational expression between the sensor output and the left and right tire contact load is obtained in advance. Thus, the left and right tire contact load can be obtained from the strain in the pulling direction of the inner ring.

  Similarly, in the vehicle body side track member of the hub unit, a relatively large strain is generated in the vicinity of the vertical line passing through the center between the rolling elements, and the strain on the vehicle body side track member is the lowermost portion on the side close to the ground contact center. The distortion in the compression direction is the largest at. Therefore, a larger inverse magnetostrictive effect can be detected by arranging the magnetostrictive sensor so as to detect the compressive strain of the vehicle body side track member. Moreover, the output of the magnetostrictive sensor obtained by detecting the strain in the compression direction has a very high correlation with the left and right tire contact load, and therefore, a relational expression between the sensor output and the left and right tire contact load is obtained in advance. Thus, the left and right tire contact load can be obtained from the distortion in the compression direction of the vehicle body side track member.

  The magnetostrictive sensor may face the shoulder end face of the inner ring so that the axial strain of the inner ring can be measured, and the magnetostrictive sensor can measure the tensile strain in the radial direction of the inner ring. Furthermore, it may face the outer peripheral surface of the shoulder portion of the inner ring. In either case, the inverse magnetostriction effect can be measured from the same direction as the tensile strain direction, and measurement with the maximum sensitivity of the magnetostrictive sensor becomes possible.

  The magnetostrictive sensor for measuring the compressive strain of the vehicle body side track member is preferably exposed to the vehicle body side track member from the outside in the radial direction. By measuring the inverse magnetostriction effect from the radial direction, that is, the direction orthogonal to the compression strain, with respect to the direction (axial direction) of the compressive strain, measurement with the maximum sensitivity of the magnetostrictive sensor becomes possible.

  A hub unit with a sensor according to a second invention includes a vehicle body side track member fixed to the vehicle body side, an inner shaft having a wheel mounting flange, and a wheel side track member to which a wheel is mounted having an inner ring fitted to the inner shaft. , As well as a hub unit with a sensor comprising a hub unit having two rows of rolling elements arranged between both raceway members, and a sensor device, the sensor device has a displacement sensor, and the displacement sensor has an inner ring It is attached to the vehicle body side track member so that the displacement at the uppermost part or the lowermost part of either the vehicle body side track member or the vehicle body side track member can be measured, and the right and left tire contact load is detected from the output of the displacement sensor. To do.

  The displacement sensor may be any of eddy current type, laser type, optical type using PSD, ultrasonic type, magnetic type, magnetostrictive type, etc. The contact type may be used instead of the non-contact type.

  The ground load applied to each tire varies with changes in the speed and posture of the traveling vehicle. At this time, the displacement of the wheel side track member (especially the inner ring) and the vehicle body side track member changes according to the tire ground load. To do. By detecting this change in displacement with a displacement sensor and calculating backward, the amount of variation in the tire ground contact load can be obtained.

  When a ground load acts on the tire, compression or tension distortion occurs in each part of the hub unit. Usually, the vertical line passing through the center between the two rows of rolling elements of the hub unit is axially outer than the vertical line passing through the center of the tire, and has a wheel-side track member including an inner shaft and an inner ring. In the unit, a relatively large distortion (displacement) occurs in the inner ring near the vehicle body. The displacement of the inner ring is maximum at the uppermost part on the opposite side of the grounding center and the lowermost part on the grounding center side. Therefore, a larger displacement can be detected by arranging the displacement sensor so as to detect the displacement at the uppermost part or the lowermost part of the inner ring. In addition, the output of the displacement sensor obtained by detecting this displacement has a very high correlation with the left-right tire contact load, and therefore, by obtaining in advance a relational expression between the sensor output and the left-right tire contact load, The left and right tire contact load can be obtained from the displacement of the inner ring.

  Similarly, in the vehicle body side track member of the hub unit, a relatively large strain is generated in the vicinity of the vertical line passing through the center between the rolling elements, and the strain on the vehicle body side track member is the lowermost portion on the side close to the ground contact center. The maximum strain in the compression direction, and the maximum strain in the tension direction at the uppermost portion on the side far from the ground center. Therefore, a larger displacement can be detected by arranging the displacement sensor so as to detect a radial displacement in the vicinity of the rolling elements of the vehicle body side track member. Further, in the flange of the vehicle body side track member, the axial displacement is maximum at the lowermost part and the uppermost part. Therefore, a larger displacement can be detected by disposing the displacement sensor so as to detect the axial displacement of the flange at the lowermost part and the uppermost part of the vehicle body side track member.

  In addition, the output of the displacement sensor obtained by detecting each displacement of the vehicle body side track member has a very high correlation with the left and right tire contact load. Therefore, the relational expression between the sensor output and the left and right tire contact load is calculated in advance. By obtaining this, the left and right tire contact load can be obtained from the displacement.

  In the hub unit with a sensor according to the second invention, the displacement sensor may face the shoulder end face of the inner ring so as to be able to measure the displacement in the radial direction of the inner ring. The displacement sensor may face the flange of the vehicle body side raceway member from the axially inner side. In any case, the displacement sensor can detect a large displacement.

  According to the hub unit with a sensor of the first invention, the magnetostrictive sensor detects the reverse magnetostrictive effect accompanying the tensile strain at the uppermost part of the inner ring near the rolling element or the compressive strain at the lowermost part of the vehicle body side track member. Measurement is performed at a location where the magnetostrictive effect is large, and therefore the tire ground contact load can be detected with high accuracy. The tire ground contact load thus obtained is used as substitute data for the slip ratio in the ABS control, and is used in driving force control, braking force control, and the like, and can contribute to improvement in accuracy of vehicle control. Moreover, the output of the magnetostrictive sensor has a very high correlation with the left and right tire contact load regardless of whether the inner ring tensile strain or the vehicle body side track member compressive strain is detected. The ground load can be obtained. Thus, the obtained lateral tire contact load in the left-right direction becomes important data for control during turning of the vehicle and the like, and control before the wheel slips becomes possible.

  According to the hub unit with a sensor of the second invention, since the displacement sensor detects the displacement of the maximum displacement portion of the inner ring or the vehicle body side race member, the measurement is performed at a location where the displacement is large, and therefore the tire ground contact load is accurately measured. Can be detected. The tire ground contact load thus obtained is used as substitute data for the slip ratio in the ABS control, and is used in driving force control, braking force control, and the like, and can contribute to improvement in accuracy of vehicle control. In addition, when detecting any displacement of the inner ring and the vehicle body side track member, the output of the displacement sensor has an extremely high correlation with the left and right tire contact load, and therefore the left and right tire contact load can be obtained from the displacement. . Thus, the obtained lateral tire contact load in the left-right direction becomes important data for control during turning of the vehicle and the like, and control before the wheel slips becomes possible.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a first embodiment of a hub unit with a sensor according to a first invention. In the following description, the left and right refer to the left and right in FIG. Note that the left is inside the vehicle and the right is outside the vehicle.

  This sensor-equipped hub unit includes a hub unit (1) and a sensor device (2) for detecting the rotation and tire ground contact load.

  The hub unit (1) is arranged in two rows between the vehicle body side track member (3) fixed to the vehicle body side, the wheel side track member (4) to which the wheel is attached, and both members (3) and (4). A ball (5), which is a plurality of rolling elements, and a cage (6) for holding each row of balls (5) are provided.

  The vehicle body side raceway member (3) has a function of an outer ring (fixed ring) of the bearing. A cylindrical part (12) in which two rows of outer ring raceways are formed on the inner peripheral surface, and a cylindrical part (12 ) And a flange portion (13) attached to the suspension device (vehicle body) with a bolt.

  The wheel side raceway member (4) has a large diameter portion (15) having a first raceway groove (15a) and a small diameter portion (16) having an outer diameter smaller than the diameter of the first raceway groove (15a). The inner ring (14), and the inner ring (14), the inner ring (14), which has a small diameter part (16) and is fitted to the outer diameter, and the right side is in close contact with the left side of the large diameter part (15) of the inner axis (14) (17) Near the right end of the inner shaft (14), a flange portion (18) to which a plurality of bolts (19) for attaching a wheel is fixed is provided. A raceway groove (17a) is formed in the right part of the inner ring (17) so as to be parallel to the raceway groove (15a) of the inner shaft (14), and a shoulder part (17b ) Is formed. A seal device (20) is provided between the right end of the vehicle body side raceway member (3) and the inner shaft (14). A male screw is provided at the left end of the small diameter portion (16) of the inner shaft (14), and the inner ring (17) is connected to the inner shaft (14) by a nut (21) screwed to the male screw. It is fixed to. A cover (22) is covered with the left end portion of the vehicle body side track member (3).

  The sensor device (2) processes the output of the support member (7) attached to the vehicle body side track member (3), the magnetostrictive sensor (8) attached to the support member (7), and the magnetostrictive sensor (8). Processing means (not shown). The magnetostrictive sensor (8) is a magneto-impedance sensor, and the sensing surface of the inner ring so as to measure the tensile strain at the uppermost left end surface of the inner ring (17) of the wheel side raceway member (4) is measured. It faces the uppermost left end surface of (17) from the outside in the radial direction.

  When contact load (radial load and axial load) acts on the tire, compression or tension distortion occurs in each part of the hub unit (1). Usually, the vertical line (C) passing through the center between the two rows of balls (5) of the hub unit (1) is axially outside the vertical line passing through the center (O) of the tire, and the inner shaft (14) In the hub unit (1) having the wheel side raceway member (4) including the inner ring (17), a relatively large distortion is generated in the inner ring (17) close to the vehicle body side. The strain of the inner ring (17) is the strain in the pulling direction that is maximized at the uppermost portion on the opposite side of the center of contact. The magnetostrictive sensor (8) exhibits maximum sensitivity when it is exposed from a direction orthogonal to the compressive strain and from the same direction as the tensile strain. Therefore, as shown in FIG. 1, the magnetostrictive sensor (8) is arranged just outside the uppermost portion of the inner ring shoulder (17b) so as to detect the tensile strain on the left end surface of the inner ring (17). A large inverse magnetostrictive effect is detected.

  FIG. 3 shows the result of investigating the relationship between the output of the magnetostrictive sensor obtained by detecting the strain in the tension direction and the tire contact load in the left-right direction. As shown in the figure, the distortion (MI output voltage change amount) and the lateral G (lateral tire contact load) have a linear relationship, and therefore, the relational expression (y = By obtaining a and b) in ax + b in advance, the left and right tire contact load can be obtained from the radial tensile strain of the inner ring (17).

  FIG. 2 shows a second embodiment of the sensor-equipped hub unit according to the first invention. The sensor-equipped hub unit of the second embodiment is different from that of the first embodiment in the configuration of the sensor device. In the following description, the same components are denoted by the same reference numerals, and the description thereof is omitted.

  The sensor device (2) of the hub unit with sensor of the second embodiment includes a support member (7) attached to the vehicle body side track member (3), and a magnetostrictive sensor (9) attached to the support member (7). And a processing means (not shown) for processing the output of the magnetostrictive sensor (9). And the magnetostrictive sensor (9) is a magneto-impedance sensor, and its sensing surface is a wheel so as to measure the tensile strain at the outermost surface of the uppermost part of the inner ring (17) of the wheel side raceway member (4). The left end surface of the uppermost portion of the inner ring shoulder (17b) of the side raceway member (4) faces from the left in the axial direction. Thus, a large inverse magnetostrictive effect is detected by arranging the magnetostrictive sensor (9) immediately to the left of the top of the inner ring shoulder (17b) so as to detect the axial tensile strain of the inner ring (17). .

  The relationship between the output of the magnetostrictive sensor obtained by detecting the strain in the pulling direction and the left and right tire contact load is the same as in FIG. 3, and the strain (MI output voltage change amount) and the lateral G (left and right tire contact load) are the same. ) Is in a linear relationship, and therefore, by obtaining in advance a relational expression (y and a and b in y = ax + b) between the sensor output and the left and right tire contact load, it can be obtained from the axial tensile strain of the inner ring (17). The left and right tire contact load can be obtained.

  FIG. 4 shows a third embodiment of the sensor-equipped hub unit of the first invention. The sensor-equipped hub unit according to the third embodiment is different from that of the first embodiment in the configuration of the sensor device. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. Is omitted.

  The sensor device (2) processes the output of the support member (7) attached to the vehicle body side track member (3), the magnetostrictive sensor (10) attached to the support member (7), and the magnetostrictive sensor (10). Processing means (not shown). The magnetostrictive sensor (10) is a magneto-impedance sensor, and its sensing surface faces the outer peripheral surface of the lowermost part of the vehicle body side track member (3) from the outside in the radial direction.

  When contact load (radial load and axial load) acts on the tire, compression or tension distortion occurs in each part of the hub unit (1). Usually, the vertical line (C) passing through the center between the two rows of balls (5) of the hub unit (1) is axially outside the vertical line passing through the center (O) of the tire, and the hub unit (1) In the vehicle body side raceway member (3), a relatively large distortion occurs in the vicinity of a vertical line passing through the center between the two rows of balls (5). The distortion of the vehicle body side raceway member (3) is the maximum strain in the compression direction at the bottom of the ground contact side, and the maximum strain in the tension direction at the uppermost part opposite to the ground contact center. Become. The magnetostrictive sensor (10) exhibits the maximum sensitivity when facing from the direction orthogonal to the compressive strain and from the same direction as the tensile strain. Therefore, as shown in FIG. 4, in order to detect the axial compressive strain of the vehicle body side track member (3), the magnetostrictive sensor (10) is placed immediately on the outer peripheral surface of the vicinity of the ball of the vehicle body side track member (3). A large inverse magnetostriction effect is detected by disposing outward.

  FIG. 5 shows the results of investigating the relationship between the output of the magnetostrictive sensor obtained by detecting the strain in the compression direction and the tire ground contact load in the left-right direction. As shown in the figure, the distortion (MI output voltage change amount) and the lateral G (lateral tire contact load) have a linear relationship, and therefore, the relational expression (y = By obtaining a and b) in ax + b in advance, the left and right tire contact load can be obtained from the distortion in the compression direction of the vehicle body side raceway member (3).

  In the third embodiment, the magnetostrictive sensor (10) is faced in the vicinity of the left row of balls (5), but the vertical line passing through the center between this position and the two rows of balls (5) (C If the magnetostrictive sensor (10) is provided in the vicinity of the ball (5) in the right row, which is a symmetric position via), the same effect as described above can be obtained.

  In each embodiment, the attachment position and the shape of the support member (7) for supporting the magnetostrictive sensors (8), (9), and (10) are not particularly limited.

  In each of the first to third embodiments, the vehicle body side race member (3) and the wheel side race member (4) are made of carbon steel for machine structure (S55C), which is an iron-based magnetic body, and rolling members ( 5) is made of high carbon chromium bearing steel (SUJ2) or ceramics, and the cage (6) is made of resin (polyamide 66). Here, when the rolling member (5) is made of ceramics, the vehicle body side race member (3) and the wheel side race member (4) have magnetism, whereas the rolling member (5) and the holding member Since the vessel (6) is made of a nonmagnetic material, the inner ring (17) and the inner shaft (14) move closer to and away from the magnetostrictive sensors (8), (9), and (10). However, it does not affect the magnetic field in the vicinity of the shoulder (17b) of the inner ring (17) and in the vicinity of the ball of the vehicle body side raceway member (3), so that the rotation of the ball (5) and the cage (6) The resulting error (noise) does not occur, and the error contained in the data detected by the highly sensitive magnetostrictive sensors (8), (9), and (10) can be made very small. Thus, according to this sensor-equipped hub unit, the rotation (number of rotations, rotation speed, rotation angle, etc.) of the hub unit (1) is determined by the magnetostrictive sensors (8), (9), and (10), and the hub unit (1 ) Is accurately detected.

  Next, a sensor-equipped hub unit according to the second invention will be described.

  A first embodiment of the sensor-equipped hub unit according to the second invention is shown in FIG. In this embodiment, the sensor is a magnetostrictive sensor (8) in FIG. 1, but a displacement sensor (11) is used instead of the magnetostrictive sensor. The displacement sensor (11) detects the radial displacement of the outer peripheral surface of the inner ring (17) and the shoulder (17b). In FIG. 6, except for the sensor (11), it is the same as that shown in FIG. 1, and the same components are denoted by the same reference numerals and the description thereof is omitted.

  FIG. 7 shows the result of investigating the relationship between the output of the displacement sensor (11) obtained by detecting the radial displacement and the left and right tire ground contact load. As shown in the figure, the displacement and the lateral G (left and right tire contact load) are in a linear relationship. Therefore, the relational expression (a and b in y = ax + b) between the sensor output and the left and right tire contact load is expressed as follows. By obtaining in advance, the left and right tire contact load can be obtained from the radial displacement of the shoulder portion of the inner ring.

  In the first embodiment of the sensor-equipped hub unit according to the second aspect of the invention, the displacement sensor (11) is shifted by 180 ° from the position shown in FIG. 6, and the outer circumference of the inner ring (17) shoulder (17b) in the lowermost part. The displacement of the surface may be measured, and even in this case, the same effect as described above can be obtained.

  In the second embodiment of the sensor-equipped hub unit according to the second aspect of the present invention, the magnetostrictive sensor (10) in FIG. 4 is replaced with a displacement sensor, and the displacement sensor allows the radial displacement of the outer peripheral surface of the vehicle body side track member (3). It was made to detect. Although the internal structure of the sensor is different, the illustration of this embodiment is the same as FIG.

  FIG. 9 shows the results of investigating the relationship between the displacement sensor output obtained by detecting the radial displacement of the vehicle body side track member (3) and the tire contact load in the left-right direction. As shown in the figure, the displacement and the lateral G (left and right tire contact load) are in a linear relationship. Therefore, the relational expression (a and b in y = ax + b) between the sensor output and the left and right tire contact load is expressed as follows. By obtaining in advance, the left and right tire contact load can be obtained from the radial displacement of the vehicle body side track member.

  FIG. 8 shows a third embodiment of the sensor-equipped hub unit of the second invention. The sensor-equipped hub unit according to the third embodiment is configured to detect the axial displacement of the flange (18) of the vehicle body side raceway member (3) by the displacement sensor (11). In FIG. 8, the same components as those of the first embodiment shown in FIG.

  The sensor device (2) processes the outputs of the support member (7) attached to the vehicle body side track member (3), the displacement sensor (11) attached to the support member (7), and the displacement sensor (11). Processing means (not shown). The displacement sensor (11) faces the left side surface of the flange (18) of the vehicle body side raceway member (3) from the axially inner side (left side).

  The relationship between the output of the displacement sensor (11) and the left and right tire ground contact load in the third embodiment is the same as in FIG. 9, and therefore, the relational expression between the sensor output and the left and right tire contact load (a in y = ax + b) And b) can be obtained in advance from the axial displacement of the flange (18) of the vehicle body side track member (3).

  In the second and third embodiments of the sensor-equipped hub unit of the second invention, the outer diameter of the vehicle body side track member (3) at the uppermost position is shifted by 180 ° from the position shown in the figure. Alternatively, the displacement of the flange (18) may be measured, and in this case, the same effect as described above can be obtained.

  Further, in each embodiment, the support member (7) that supports the displacement sensor (11) is not particularly limited in the mounting position and the shape thereof, but the base of the support member (7) is a vehicle body side track member. It is preferable to fix in the vicinity of the part fixed to the vehicle body of (3).

It is a longitudinal cross-sectional view which shows 1st Embodiment of the hub unit with a sensor by 1st invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the hub unit with a sensor by 1st invention. It is a graph which shows the relationship between the output of the magnetostriction sensor in 1st and 2nd Embodiment of 1st invention, and lateral G. FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the hub unit with a sensor by 1st invention. It is a graph which shows the relationship between the output of the magnetostriction sensor in 3rd Embodiment of 1st invention, and lateral G. FIG. It is a longitudinal cross-sectional view which shows 1st Embodiment of the hub unit with a sensor by 2nd invention. It is a graph which shows the relationship between the output of the displacement sensor and horizontal G in 1st Embodiment of 2nd invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the hub unit with a sensor by 2nd invention. It is a graph which shows the relationship between the output of the displacement sensor and the horizontal G in 2nd and 3rd embodiment of 2nd invention.

Explanation of symbols

(1) Hub unit
(2) Sensor device
(3) Car body side track member
(4) Wheel-side track member
(5) Ball (rolling element)
(8) Magnetostrictive sensor for measuring radial tensile strain
(9) Magnetostrictive sensor for measuring axial tensile strain
(10) Magnetostrictive sensor for measuring axial compressive strain
(11) Displacement sensor
(17) Inner ring
(17b) Inner ring shoulder

Claims (8)

A vehicle body side track member fixed to the vehicle body side, an inner shaft having a wheel mounting flange, a wheel side track member having an inner ring fitted to the inner shaft and to which a wheel is mounted, and disposed between both track members. In a hub unit with a sensor comprising a hub unit having two rows of rolling elements and a sensor device,
The sensor device includes a magnetostrictive sensor that detects an inverse magnetostrictive effect, and the magnetostrictive sensor is capable of measuring either tensile strain at the uppermost portion of the inner ring and compressive strain at the lowermost portion of the vehicle body side track member. A hub unit with a sensor, which is attached to a side raceway member and detects a left-right tire ground load from an output of a magnetostrictive sensor. 2. The sensor-equipped hub unit according to claim 1, wherein the magnetostrictive sensor faces the shoulder end face of the inner ring so that an axial tensile strain of the inner ring can be measured. 2. The sensor-equipped hub unit according to claim 1, wherein the magnetostrictive sensor faces the outer peripheral surface of the shoulder portion of the inner ring so that the tensile strain in the radial direction of the inner ring can be measured. The hub unit with a sensor according to claim 1, wherein the magnetostrictive sensor faces the vehicle body side track member from the outside in the radial direction. A vehicle body side track member fixed to the vehicle body side, an inner shaft having a wheel mounting flange, a wheel side track member having an inner ring fitted to the inner shaft and to which a wheel is mounted, and disposed between both track members. In a hub unit with a sensor comprising a hub unit having two rows of rolling elements and a sensor device,
The sensor device includes a displacement sensor, and the displacement sensor is attached to the vehicle body side track member so as to be able to measure the displacement at the uppermost part or the lowermost part of either the inner ring or the vehicle body side track member. A sensor-equipped hub unit that detects a tire ground load in a left-right direction from an output. The hub unit with a sensor according to claim 5, wherein the displacement sensor faces the end surface of the shoulder portion of the inner ring so that the displacement in the radial direction of the inner ring can be measured. 6. The sensor-equipped hub unit according to claim 5, wherein the displacement sensor faces the vehicle body side track member from the outside in the radial direction. 6. The sensor-equipped hub unit according to claim 5, wherein the displacement sensor faces the flange of the vehicle body side track member from the inside in the axial direction.

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