JP2008241379A - Bearing for wheel with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a wheel with a sensor capable of installing a sensor for load detection compactly in a vehicle, preventing the influence of breakage, failure, and electromagnetic noise, and enabling sensitive detection of a load over a long time, and reducing the cost. <P>SOLUTION: The bearing for the wheel with the sensor comprises an outer member 1, an inner member 2, and a plurality of rows of rolling bodies 5 interposed in between rolling surfaces 3 and 4, and supports the wheel on a vehicle body rotatably, and distortion sensor 21 is attached to the outer member 1 as a fixed member, for example, of the outer member and inner member. The distortion sensor 21 is formed of a distortion generating member 22, and a sensor element 23 that is attached to the distortion generating member 22 and detects the distortion of the distortion generating member 22. An attachment surface 22ca of the sensor element 23 of the distortion generating part material 22 of the distortion sensor 21 is provided with a covering material 24 that covers at least the sensor element 23, in a sealed state and is made of over-molded resin or vulcanization adhered elastomer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sensor-equipped wheel bearing with a built-in load sensor for detecting a load applied to a bearing portion of the wheel.

  2. Description of the Related Art Conventionally, there is a wheel bearing provided with a sensor for detecting the rotational speed of each wheel for safe driving of an automobile. Conventional measures to ensure driving safety of general automobiles are performed by detecting the rotational speed of the wheels of each part, but the rotational speed of the wheels is not sufficient, and it is further safer by using other sensor signals. It is required that the surface can be controlled.

  Therefore, it is conceivable to control the posture from the load acting on each wheel during vehicle travel. For example, a large load is applied to the outer wheel in cornering, and the load applied to each wheel is not uniform. In addition, even when the load is uneven, the load applied to each wheel is uneven. For this reason, if the load applied to the wheel can be detected at any time, the suspension control etc. is controlled in advance based on the detection result, thereby controlling the attitude during vehicle travel (preventing rolling during cornering, preventing the front wheel from sinking during braking, It is possible to prevent subsidence due to uneven load capacity. However, there is no appropriate installation location of a sensor that detects a load acting on the wheel, and it is difficult to realize posture control by load detection.

  In addition, when steer-by-wire is introduced in the future and the system becomes a system in which the axle and the steering are not mechanically coupled, it is required to detect the axle direction load and transmit the road surface information to the handle held by the driver.

As a response to such a demand, a wheel bearing has been proposed in which a strain gauge is attached to the outer ring of the wheel bearing to detect the strain (for example, Patent Document 1).
Special table 2003-530565 gazette

  The outer ring of the wheel bearing is a part that has a rolling surface and requires strength, and is a bearing part that is produced through complicated processes such as plastic working, turning, heat treatment, and grinding. When a strain gauge is attached to the outer ring as in Patent Document 1, there is a problem that productivity is poor and the cost for mass production is high. In addition, it is difficult to detect the distortion of the outer ring with high sensitivity, and when the detection result is used for attitude control during vehicle travel, the accuracy of control becomes a problem.

In order to solve these problems, a strain sensor comprising a strain generating member and a sensor element such as a strain gauge attached to the strain generating member and detecting the strain of the strain generating member is provided as a fixed ring of a wheel bearing. For example, the structure attached to the outer ring can be considered. In this case, the strain generating member includes a first contact fixing portion that is fixed to the body mounting flange surface of the outer ring, and a second contact fixing portion that is fixed to the outer periphery of the outer ring.
In the wheel bearing having such a configuration, when a load is applied to the hub wheel which is a rotation side member as the vehicle travels, the outer ring is deformed via the rolling elements, and the deformation is transmitted to the strain generating member of the strain sensor. The sensor element attached to the strain generating member measures the strain. Since the first contact fixing portion of the strain generating member is fixed to the body mounting flange surface of the outer ring, and the second contact fixing portion is fixed to the outer ring outer periphery, the first and second contact fixing portions The radial positions of the outer ring are different, and the distortion of the outer ring is likely to expand and appear on the distortion generating member. Since this enlarged distortion is measured by the sensor element, the distortion of the outer ring can be detected with high sensitivity.

  However, in the case of the above configuration, since the strain sensor is exposed outside the wheel bearing, the strain sensor may be damaged or broken down due to the external environment (intrusion of muddy water, collision of foreign matter, etc.), and accurate strain detection is possible. It cannot be done for a long time. Further, since the sensor element in the strain sensor is an electronic component, it is easily affected by external electromagnetic noise, and the reliability of the detection result is lowered in the above-described exposed state.

  The object of the present invention is to install a load detection sensor in a compact vehicle, prevent damage or failure due to the external environment and the influence of electromagnetic noise from the outside, can detect the load applied to the wheel over a long period of time, The object is to provide a sensor-equipped wheel bearing that is inexpensive in mass production.

The sensor-equipped wheel bearing according to the present invention includes an outer member having a double row rolling surface formed on the inner periphery, an inner member having a rolling surface facing the rolling surface of the outer member, In a wheel bearing comprising a double row rolling element interposed between both rolling surfaces, and rotatably supporting the wheel with respect to the vehicle body,
A strain sensor comprising a strain generating member and a sensor element that is attached to the strain generating member and detects the strain of the strain generating member is attached to a fixed side member of the outer member and the inner member. The mounting surface of the sensor element of the strain generating member is provided with a covering material made of overmolded resin or vulcanized elastomer so as to cover at least the sensor element in a sealed state.

When a load is applied to the rotation side member as the vehicle travels, the fixed side member is deformed via the rolling elements, and the deformation causes distortion of the strain generating member. The sensor element attached to the strain generating member detects the strain of the strain generating member. If the relationship between strain and load is obtained in advance through experiments and simulations, the load applied to the wheel can be detected from the output of the sensor element.
Since the wheel bearing has a configuration in which a strain sensor including a strain generating member and a sensor element attached to the strain generating member is attached to the fixed member, the load detection sensor can be compactly installed in the vehicle. Since the strain generating member is a simple part that can be attached to the fixed member, attaching the sensor element to the member can provide excellent mass productivity and reduce the cost.
In particular, a cover material made of overmolded resin or vulcanized elastomer is provided on the mounting surface of the sensor element of the strain generating member, and at least the sensor element is sealed with this cover material in a sealed state. It is possible to prevent the sensor element from being damaged or broken due to intrusion of sewage or collision of foreign matter depending on the external environment. As a result, highly accurate distortion detection is possible over a long period of time. In addition, since it is possible to prevent the influence of external electromagnetic noise from affecting the sensor element, it is possible to measure distortion with higher accuracy.

The strain generating member has two contact fixing portions with respect to the fixed side member, and the first contact fixing portion of the contact fixing portions is a fixing portion for a flange surface provided on the fixed side member. The second contact fixing portion may be a fixing portion with respect to the peripheral surface of the fixed side member.
Thus, the strain generating member has two contact fixing portions, the first contact fixing portion is a flange surface provided on the fixing side member, and the second contact fixing portion is the fixing side member. In the case of the peripheral surface, the radial positions of the first and second contact fixing portions are different, and the distortion of the fixing-side member is easily transferred and enlarged to the distortion generating member. Since this transferred and enlarged strain is measured by the sensor element, the strain of the fixed member can be detected with high sensitivity, and the load measurement accuracy is increased.

In this invention, you may pull out the cable of the said sensor element in the said strain sensor from the vicinity of the contact fixing | fixed part with respect to the surrounding surface of the said fixed side member in the said strain generation member in the circumferential direction of the said fixed side member.
In this case, the cable of the sensor element can be routed along the peripheral surface of the fixed side member, so that the cable does not get in the way compared to the case of wiring along the flange of the fixed side member, and the electromagnetic noise to the output signal of the sensor element Can be further reduced.

Another sensor-equipped wheel bearing according to the present invention includes an outer member in which double-row rolling surfaces are formed on the inner periphery, and an inner member in which a rolling surface facing the rolling surface of the outer member is formed. And a double-row rolling element interposed between both rolling surfaces, and a wheel bearing for rotatably supporting the wheel with respect to the vehicle body, the distortion generating member and the distortion generating member attached to the distortion generating member A strain sensor comprising a sensor element for detecting the strain of the member is attached to the fixed side member of the outer member and the inner member, and the strain generating member has two contact fixing portions with respect to the fixed side member. A first contact fixing portion of the contact fixing portion is a flange surface provided on the fixing side member, and a second contact fixing portion is a peripheral surface of the fixing side member, in the strain sensor The cable of the sensor element is connected to the strain generating member. It is characterized in that it is pulled out in the circumferential direction of the fixed side member from the vicinity of the contact fixing portion with respect to the peripheral surface of the fixed side member.
According to this configuration, since the cable of the sensor element can be wired along the peripheral surface of the fixed side member, the cable does not get in the way compared to the case of wiring along the flange of the fixed side member, and the output signal of the sensor element is not disturbed. The influence of electromagnetic noise can also be reduced.

As described above, when the cable of the sensor element in the strain sensor is pulled out in the circumferential direction of the fixed side member from the vicinity of the contact fixing portion with respect to the peripheral surface of the fixed side member in the strain generating member, the cable It is also possible to provide a clamp member with a ferrite that fixes to the peripheral surface of the fixed side member.
In the case of this configuration, since the cable is fixed to the peripheral surface of the fixed side member by the clamp member with the ferrite core, the noise resistance of the signal path from the sensor element to the signal processing circuit can be improved. Moreover, by adding a ferrite core having a function of effectively attenuating high frequency components such as electromagnetic noise to the clamp member in this way, it is not necessary to provide a separate installation space for the ferrite core. The ferrite core can be easily fixed.

The wheel bearing with sensor of the present invention is an outer member in which double-row rolling surfaces are formed on the inner periphery, and an inner member that forms a rolling surface facing the rolling surface of the outer member, A double-row rolling element interposed between both rolling surfaces, and a wheel bearing for rotatably supporting a wheel with respect to a vehicle body. A strain sensor composed of a sensor element for detecting strain is attached to a fixed side member of the outer member and the inner member, and at least the sensor element is mounted on a mounting surface of the strain element of the strain sensor. The cover is made of overmolded resin or vulcanized elastomer, so that the load detection sensor can be installed compactly in the vehicle. The effect of these electromagnetic noises can be prevented, the load on the wheel can be detected with high sensitivity over a long period of time, and the cost for mass production is also low.
The strain generating member has two contact fixing portions with respect to the fixed side member, and the first contact fixing portion of the contact fixing portions is a fixing portion for a flange surface provided on the fixed side member. When the second contact fixing part is a fixing part with respect to the peripheral surface of the fixed side member, the distortion of the fixed side member can be detected with high sensitivity, and the measurement accuracy of the load is further increased.
Another sensor-equipped wheel bearing according to the present invention includes an outer member having a double-row rolling surface formed on the inner periphery, and an inner member having a rolling surface facing the rolling surface of the outer member. And a double-row rolling element interposed between both rolling surfaces, and a wheel bearing for rotatably supporting the wheel with respect to the vehicle body, the distortion generating member and the distortion generating member attached to the distortion generating member A strain sensor comprising a sensor element for detecting the strain of the member is attached to the fixed side member of the outer member and the inner member, and the strain generating member has two contact fixing portions with respect to the fixed side member. A first contact fixing portion of the contact fixing portion is a flange surface provided on the fixing side member; a second contact fixing portion is a peripheral surface of the fixing side member; The cable of the sensor element is connected to the strain generating member. Since it is pulled out in the circumferential direction of the fixed side member from the vicinity of the contact fixing portion with respect to the peripheral surface of the fixed side member, a load detection sensor can be installed in the vehicle in a compact manner. The effects of noise can be prevented, the load applied to the wheel over a long period of time can be detected with high sensitivity, and the cost for mass production is also low.

An embodiment of the present invention will be described with reference to FIGS. This embodiment is a third generation inner ring rotating type and is applied to a wheel bearing for driving wheel support. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.
As shown in the sectional view of FIG. 1, the bearing for this sensor-equipped wheel bearing includes an outer member 1 in which a double row rolling surface 3 is formed on the inner periphery, and rolling facing each of these rolling surfaces 3. The inner member 2 formed with the surface 4 and the double row rolling elements 5 interposed between the outer member 1 and the rolling surfaces 3 and 4 of the inner member 2 are constituted. This wheel bearing is a double-row angular ball bearing type, and the rolling elements 5 are made of balls and are held by a cage 6 for each row. The rolling surfaces 3 and 4 have a circular arc shape in cross section, and the rolling surfaces 3 and 4 are formed so that the contact angles are aligned with the back surface. Both ends of the bearing space between the outer member 1 and the inner member 2 are sealed by a pair of seals 7 and 8, respectively.

The outer member 1 is a fixed-side member, and has a flange 1a for mounting a vehicle body attached to a knuckle in a suspension device (not shown) of the vehicle body on the outer periphery, and the whole is an integral part. Bolt holes 14 for mounting the vehicle body are provided in the flange 1a at a plurality of locations in the circumferential direction.
The inner member 2 is a rotating side member, and includes a hub wheel 9 having a hub flange 9a for wheel mounting, and an inner ring 10 fitted to the outer periphery of the end portion on the inboard side of the shaft portion 9b of the hub wheel 9. And become. The hub wheel 9 and the inner ring 10 are formed with the rolling surfaces 4 of the respective rows. An inner ring fitting surface 12 having a small diameter with a step is provided on the outer periphery of the inboard side end of the hub wheel 9, and the inner ring 10 is fitted to the inner ring fitting surface 12. A through hole 11 is provided at the center of the hub wheel 9. The hub flange 9a is provided with press-fit holes 16 for hub bolts 15 at a plurality of locations in the circumferential direction. In the vicinity of the base portion of the hub flange 9a of the hub wheel 9, a cylindrical pilot portion 13 for guiding a wheel and a braking component (not shown) protrudes toward the outboard side.

  A strain sensor 21 shown in FIG. 3 is provided on the outer peripheral portion of the outer member 1. The strain sensor 21 is obtained by attaching a sensor element 23 that detects the strain of the strain generating member 22 to the strain generating member 22. The distortion generating member 22 includes a first contact fixing portion 22a which is fixed in contact with the vicinity of the bolt hole 14 of the flange surface 1aa facing the outboard side in the flange 1a for mounting the vehicle body of the outer member 1, and the outer member. And a second contact fixing portion 22b fixed to the outer peripheral surface 1b. The strain generating member 22 includes a radial portion 22c along the radial direction including the first contact fixing portion 22a and an axial portion 22d along the axial direction including the second contact fixing portion 22b. The intermediate portion of the radial portion 22c is the first contact fixing portion 22a, and the tip of the axial portion 22d is the second contact fixing portion 22b. Here, the radial portion 22c and the axial portion 22d of the strain generating member 22 are integrated, and the first and second contact fixing portions 22a and 22b, which are separate products, are fixed to the integrated product. However, the entire strain generating member 22 may be integrated.

  The sensor element 23 is disposed at a position radially inward of the first contact fixing portion 22a of the sensor mounting surface 22ca that is a surface on the inboard side of the radial portion 22c in the strain generating member 22. The sensor element 23 is fixed to the radial direction portion 22c, for example, by bonding with an adhesive. As for radial direction part 22c where sensor element 23 is arranged, it is desirable to make thickness thin so that rigidity may become low compared with axial direction part 22d.

The strain generating member 22 is provided with a covering material 24 covering at least the sensor element 23 in a sealed state from the sensor mounting surface 22ca to a surface 22da facing the outer member outer peripheral surface 1b of the axial portion 22d. The covering member 24 may cover the entire surface of the strain generating member 22. The covering member 24 is made of, for example, a resin overmolded on the surface area, or an elastomer (NBR, H-NBR, acrylic, or the like) vulcanized and bonded. As the overmold resin, for example: • Polyamide resin: 66 nylon, PPA (polyphthalimide), etc. • Special ether synthetic resin: PPS, etc. • Those obtained by adding glass fiber to these materials are suitable.

  As shown in FIGS. 1 and 2, the strain sensor 21 includes the first and second contact fixing portions 22 a and 22 b of the strain generating member 22 so that both contact fixing portions 22 a and 22 b are in the circumferential direction of the outer member 1. Are fixed to the outer peripheral portion of the outer member 1 so as to be in the same phase. When the first and second contact fixing portions 22a and 22b are in the same phase in the circumferential direction, the strain generating member 22 can be shortened, so that the strain sensor 21 can be easily installed.

  The attachment structure of the strain sensor 21 to the outer member 1 is as follows. As shown in FIG. 3, bolt insertion holes 25 and 26 penetrating in the axial direction and the radial direction are formed in the first and second contact fixing portions 22 a and 22 b of the strain generating member 22. On the other hand, bolt holes 27 and 28 are formed on the flange surface 1aa and the outer peripheral surface 1b of the outer member 1 at positions corresponding to the bolt insertion holes 25 and 26, respectively. The bolt 29 inserted from the outboard side into the bolt insertion hole 25 of the first contact fixing portion 22a is screwed into the bolt hole 27 of the flange surface 1aa of the outer member 1, and the bolt insertion of the second contact fixing portion 22b is inserted. The strain sensor 21 is fixed to the outer member 1 by screwing the bolt 30 inserted into the hole 26 from the outer peripheral side into the bolt hole 28 of the outer peripheral surface 1 b of the outer member 1.

  The strain generating member 22 has a shape or material that does not cause plastic deformation by being fixed to the outer member 1. Further, the strain generating member 22 needs to have a shape that does not cause plastic deformation even when the maximum load expected for the wheel bearing is applied. The above assumed maximum force is the maximum force assumed in traveling that does not lead to vehicle failure. This is because, when plastic deformation occurs in the strain generating member 22, the deformation of the outer member 1 is not accurately transmitted to the strain generating member 22 and affects the measurement of strain.

  Various sensors can be used as the sensor element 23. For example, the sensor element 23 may be a metal foil strain gauge, a semiconductor strain gauge, or a thick film sensor.

  As shown in FIG. 1, the sensor element 23 of the strain sensor 21 is connected to the estimation means 31. The estimation means 31 is a means for estimating the acting force between the wheel tire and the road surface based on the output signal of the sensor element 23. The estimation means 31 has a relation setting means (not shown) in which the relation between the acting force between the wheel tire and the road surface and the output signal of the sensor element 23 is set by an arithmetic expression or a table, etc., and the input output signal The action force is output using the relationship setting means. The setting contents of the relationship setting means are obtained by testing and simulation in advance.

  As shown in FIG. 2, a circuit box 32 having the estimation means 31 and the like is attached to the outer peripheral surface 1 b of the outer member 1. A cable 33 drawn from the sensor element 23 in the strain sensor 21 is wired along the flange 1a of the outer member 1 and connected to the estimation means 31 through the ferrite core 34 in the circuit box 32. Since the output signal of the sensor element 23 is input to the estimation means 31 via the ferrite core 34, the influence of electromagnetic noise on the output signal of the sensor element 23 is prevented.

  Generally, a circuit box 32 having a circuit unit for processing the output of the strain sensor 21 provided in a wheel bearing is provided in an electric control unit (ECU) of an automobile. By providing the circuit box 32 in the vicinity of the strain sensor 21 in the bearing for the vehicle, labor for wiring from the strain sensor 21 to the circuit box 32 can be simplified, and more than in the case where the circuit box 32 is provided in a place other than the wheel bearing. The circuit box 32 can be installed in a compact manner.

  The operation of the sensor-equipped wheel bearing with the above configuration will be described. When a load is applied to the hub wheel 9 as the vehicle travels, the outer member 1 is deformed via the rolling elements 5, and the deformation is transmitted to the strain generating member 22 attached to the outer member 1. 22 is deformed. The strain of the strain generating member 22 is measured by the sensor element 23. At this time, the radial portion 22 c of the strain generating member 22 is deformed according to the deformation of the flange 1 a of the outer member 1. In the case of this embodiment, the radial portion 22c is less rigid than the outer member 1, and the radial portion 22c and the axial portion 22d having higher rigidity than the radial portion 22c form an L shape. Since the strain generating member 22 is configured, the strain concentrates near the corner on the radial portion 22c side between the radial portion 22c and the axial portion 22d, resulting in a strain larger than that of the outer member 1. appear. That is, the distortion generated between the radial portion 22c and the axial portion 22d is a transfer and expansion of the distortion of the R portion at the proximal end of the flange 1a. Since this distortion is measured by the sensor element 23, the distortion of the outer member 1 can be detected with high sensitivity, and the distortion measurement accuracy is increased.

  Since the strain changes depending on the direction and magnitude of the load, if the relationship between the strain and the load is obtained in advance through experiments and simulations, the external force acting on the wheel bearing or the acting force between the tire and the road surface is calculated. be able to. The estimation means 31 is based on the relationship between the strain and the load obtained and set in advance through experiments and simulations, and the external force acting on the wheel bearing or the action between the tire and the road surface by the output of the sensor element 23. Calculate the force. In addition, when an external force acting on the wheel bearing in real time or an acting force between the tire and the road surface is output, finer vehicle control becomes possible.

  In particular, in this embodiment, a covering material 24 made of overmolded resin or vulcanized elastomer is provided on the sensor mounting surface 22ca of the strain generating member 22 in the strain sensor 21, and at least the sensor element 23 is covered. Since the material 24 is covered in a sealed state, it is possible to prevent the sensor element 23 from being damaged or broken due to the external environment (intrusion of dirty water, collision of foreign matter, etc.). As a result, highly accurate distortion detection is possible over a long period of time. In addition, since it is possible to prevent the influence of external electromagnetic noise from affecting the sensor element 23, it is possible to measure distortion with higher accuracy.

FIG. 4 shows another wiring configuration example of the cable 33 drawn from the sensor element 23 of the strain sensor 21 in the above embodiment. In this wiring configuration example, the cable 33 of the sensor element 23 is connected to the bottom surface in the axial portion 22d of the strain generating member 22, that is, in the vicinity of the second contact fixing portion 22b on the surface 22da facing the outer peripheral surface 1b of the outer member 1. From the outer circumferential surface 1 b of the outer member 1, the outer member 1 is pulled out in the circumferential direction and connected to the estimating means 31 in the circuit box 32. In this case, a portion along the outer peripheral surface 1 b of the outer member 1 of the cable 33 is fixed to the outer peripheral surface 1 b of the outer member 1 by a clamp member 35 with a ferrite core 34.
For example, as shown in FIG. 5A, the clamp member 35 with the ferrite core 34 has a thick cylindrical shape through which the cable 33 is inserted, and the mounting flange 35a protrudes. It is fixed to the outer member 1 with a bolt inserted through the hole 41 of the mounting flange 35a. The clamp member 35 may be a stack of two semi-cylindrical pieces each having a flange member 35a overlapping each other.

In the case of this wiring configuration example, since the cable 33 of the sensor element 23 can be wired along the outer peripheral surface 1b of the outer member 1, the cable 33 does not get in the way compared to the case of wiring along the flange 1a. The influence of electromagnetic noise on the output signal can be reduced.
Further, since the cable 33 is fixed to the outer peripheral surface 1b of the outer member 1 by the clamp member 35 with the ferrite core 34, the noise resistance of the signal path from the sensor element 23 to the estimating means 31 in the circuit box 32 is improved. be able to. In addition, by adding the ferrite core 34 having a function of effectively attenuating a high-frequency component such as electromagnetic noise to the clamp member 35 as described above, it is necessary to separately provide an installation space for the ferrite core 34. In addition, the ferrite core 34 can be easily fixed.
As shown in FIG. 5B, the clamp member 35 may be made of an electromagnetic wave absorbing sheet, or may be a saddle with an electromagnetic wave adsorbing sheet attached to the surface. In this case, the clamp member 35 is fixed to the surface of the outer member 1 by bolts inserted through holes provided on both sides of the cable 33, and the cable 33 is inserted into the surface of the outer member 33. Fix it.

  In addition, although the strain sensor 21 in this embodiment has a configuration in which only one sensor element 23 is attached to the strain generating member 22, a configuration in which a plurality of sensor elements 23 are attached to the strain generating member 22 may be employed. When a plurality of sensor elements 23 are attached to the strain generating member 22, it is possible to detect a load with higher accuracy.

  In this embodiment, the strain sensor 21 is provided at only one place on the outer member 1. However, the strain sensor 21 may be provided at two or more places. When the strain sensors 21 are provided at two or more locations, it becomes possible to detect a load with higher accuracy.

Moreover, although this embodiment demonstrated about the case where the outer member 1 is a stationary member, this invention can be applied also to the wheel bearing in which an inner member is a stationary member, in that case, The strain sensor 21 is provided on the peripheral surface that is the inner periphery of the inner member 2.
Further, in this embodiment, the case where the present invention is applied to a third generation type wheel bearing has been described. However, the present invention relates to a first or second generation type wheel bearing in which the bearing portion and the hub are independent parts. In addition, the present invention can also be applied to a fourth generation type wheel bearing in which a part of the inner member is composed of an outer ring of a constant velocity joint. Further, this sensor-equipped wheel bearing can be applied to a wheel bearing for a driven wheel, and can also be applied to a tapered roller type wheel bearing of each generation type.

It is sectional drawing of the bearing for wheels with a sensor concerning one Embodiment of this invention. It is the front view which looked at the outer member of the wheel bearing with a sensor from the outboard side. It is an expanded sectional view which shows the attachment structure of the distortion sensor of the wheel bearing with a sensor. It is a perspective view which shows the other example of a cable wiring structure of the wheel bearing with a sensor. It is a perspective view shown in each example of a clamp member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 1a ... Flange 1aa ... Flange surface 1b ... Outer peripheral surface 2 ... Inner member 3, 4 ... Rolling surface 5 ... Rolling body 21 ... Strain sensor 22 ... Strain generating member 22a ... 1st contact fixing | fixed part 22b ... 2nd contact fixing | fixed part 22ca ... Sensor mounting surface 23 ... Sensor element 24 ... Cover material 33 ... Cable 34 ... Ferrite core 35 ... Clamp member

Claims (5)

An outer member in which a double row rolling surface is formed on the inner periphery, an inner member having a rolling surface opposite to the rolling surface of the outer member, and a double row interposed between both rolling surfaces In the wheel bearing for supporting the wheel rotatably with respect to the vehicle body,
A strain sensor comprising a strain generating member and a sensor element that is attached to the strain generating member and detects the strain of the strain generating member is attached to a fixed side member of the outer member and the inner member. A sensor-attached surface comprising a cover member made of an overmolded resin or a vulcanized elastomer covering at least the sensor element in a sealed state on a mounting surface of the sensor element of the strain generating member. Wheel bearing.   2. The strain generating member according to claim 1, wherein the strain generating member has two contact fixing portions with respect to the fixed side member, and the first contact fixing portion of the contact fixing portions is a flange surface provided on the fixed side member. A sensor-equipped wheel bearing, wherein the second contact fixing portion is a fixing portion for the peripheral surface of the fixed-side member.   3. The cable of the sensor element in the strain sensor according to claim 1, wherein the cable of the sensor element is pulled out in the circumferential direction of the fixed member from the vicinity of the contact fixing portion with respect to the peripheral surface of the fixed member in the strain generating member. Wheel bearing with sensor. An outer member in which a double row rolling surface is formed on the inner periphery, an inner member having a rolling surface opposite to the rolling surface of the outer member, and a double row interposed between both rolling surfaces In the wheel bearing for supporting the wheel rotatably with respect to the vehicle body,
A strain sensor comprising a strain generating member and a sensor element that is attached to the strain generating member and detects the strain of the strain generating member is attached to a fixed member of the outer member and the inner member, and the strain generating member Has two contact fixing portions with respect to the fixed side member, and the first contact fixing portion of the contact fixing portions is a flange surface provided on the fixed side member, and the second contact fixing portion. Is a peripheral surface of the fixed side member, and the cable of the sensor element in the strain sensor is arranged in the circumferential direction of the fixed side member from the vicinity of the contact fixing portion with respect to the peripheral surface of the fixed side member in the strain generating member. A wheel bearing with sensor characterized by being pulled out.   5. The sensor-equipped wheel bearing according to claim 3 or 4, wherein a ferrite clamp member for fixing the cable to the peripheral surface of the stationary member is provided.

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