JP2007292157A - Wheel bearing with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing with a sensor capable of compactly mounting the sensor for load detection on a vehicle, sensitively detecting the load on a wheel and reducing costs in mass-production. <P>SOLUTION: In the wheel bearing for freely rotatably supporting a wheel to a vehicle body by interposing double-row rolling elements 3 between an outer member 1 and an inner member 2, a sensor unit 21 is mounted in a fixed side member of the outer member 1 and inner member 2. When the outer member 1 is taken as the fixed side member, for instance, the sensor unit 21 consists of a sensor mounting member 22 and one or more distortion sensor 23 mounted in a sensor mounting part 22. The sensor mounting part 22 is provided with two contact fixing parts 22a, 22b to be fixed to the outer member 1. A first contact fixing part 22a is fixed to a suspension device 16 in a vehicle body. A second contact fixing part 22b is fixed to a peripheral surface of the outer member 1. <P>COPYRIGHT: (C)2008,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 carried out 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 attitude 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. Further, even when the load is uneven, the load applied to each wheel becomes uneven. For this reason, if the load applied to the wheel can be detected at any time, based on the detection result, the suspension and the like are controlled in advance, thereby controlling the posture 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 is such that 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.

  An object of the present invention is to provide a sensor-equipped wheel bearing in which a load detection sensor can be compactly installed in a vehicle, a load applied to a wheel can be detected, and the cost during mass production is reduced.

  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 having a double row rolling element interposed between both rolling surfaces and attached to a suspension device to rotatably support the wheel with respect to the vehicle body, the sensor mounting member and the sensor mounting member A sensor unit comprising at least one or more strain sensors is attached to a fixed side member of the outer member and the inner member, and the sensor mounting member has two contact fixing parts for fixing to the fixed side member. The first contact fixing portion of the contact fixing portion is fixed to a suspension device of a vehicle body, and the second contact fixing portion is fixed to the peripheral surface of the fixed side member. It is characterized by being.

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 sensor unit. The strain sensor provided in the sensor unit detects the strain of the sensor unit. If the relationship between strain and load is obtained in advance through experiments and simulations, the load applied to the wheel and the vehicle steering moment can be detected from the output of the strain sensor. Further, the detected load and steering moment can be used for vehicle control of the automobile. The steering moment is a moment applied to the vehicle bearing when the vehicle travels on a curved path.
Since the sensor unit is fixed to the stationary member by fixing the two contact fixing portions of the sensor mounting member to the suspension of the vehicle body and the peripheral surface of the stationary member, the load applied to the wheel and the vehicle steering moment In addition, it is possible to detect the fixed state of the stationary member and the suspension device. If the fixed state is poor and there is a looseness between the fixed side member and the suspension device, the sensor mounting member is greatly distorted.
Since this wheel bearing has a structure in which a sensor unit comprising a sensor mounting member and at least one strain sensor mounted on the sensor mounting member is mounted on the stationary member, the load detection sensor can be compactly and easily mounted on the vehicle. Can be installed. Since the sensor attachment member is a simple part that is fixedly attached to the stationary member and the suspension device, attaching a strain sensor to the sensor attachment member makes it possible to achieve excellent mass productivity and reduce costs.

  In the present invention, the sensor unit can be arranged on the upper side or the lower side or both above and below the fixed side member. In this case, the load applied to the vehicle can be calculated from the output of the strain sensor.

  Moreover, in this invention, you may arrange | position the said sensor unit in the front part in the vehicle advancing direction of the said fixed side member, a rear part, or both front and back. In this case, the vehicle steering moment can be calculated from the output of the strain sensor.

The second contact fixing portion of the sensor mounting member is fixed to the peripheral surface of the fixed side member that is in the same circumferential direction as the first contact fixing portion in the circumferential direction of the fixed side member. Is good.
When the first and second contact fixing portions have the same phase in the circumferential direction, the length of the sensor mounting member can be shortened, and the sensor unit can be easily installed.

  The fixed member can be an outer member. In that case, the sensor unit is attached to the outer member.

It is preferable to provide an acting force estimating means for estimating an external force acting on the wheel bearing or an acting force between the tire and the road surface by the output of the strain sensor.
By using the external force acting on the wheel bearing obtained by the acting force estimation means or the acting force between the tire and the road surface for vehicle control of the automobile, fine vehicle control is possible.

It is preferable that the sensor unit is not plastically deformed even when a maximum force assumed as an external force acting on the stationary member or an acting force acting between the tire and the road surface is applied. The 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 sensor unit, the deformation of the fixed side member is not accurately transmitted to the sensor mounting member of the sensor unit and affects the measurement of strain.

  The sensor mounting member may be a press-processed product. If the sensor mounting member is manufactured by press working, the processing is easy and the cost can be reduced.

The sensor mounting member may be a sintered metal by metal powder injection molding.
When the sensor mounting member is manufactured by metal powder injection molding, a sensor mounting member with good dimensional accuracy can be obtained.

The sensor mounting member and the fixed side member can be fixed using either a bolt or an adhesive, or a combination of both, or welding.
When the sensor attachment member and the fixed side member are fixed by any one of the above methods, the sensor attachment member can be firmly fixed to the fixed side member. Therefore, the sensor mounting member is not displaced with respect to the fixed side member, and the deformation of the fixed side member can be accurately transmitted to the sensor mounting member.

A temperature sensor may be provided on the sensor mounting member.
Since the temperature of the wheel bearing changes during use, the temperature change affects the strain of the sensor mounting member or the operation of the strain sensor. It also has the same effect on changes in ambient environmental temperature. By correcting the temperature characteristics of the strain sensor based on the output of the temperature sensor, it is possible to detect a load with high accuracy.

The sensor mounting member may be provided with at least one of an acceleration sensor and a vibration sensor.
When various sensors such as an acceleration sensor and a vibration sensor are mounted on the sensor mounting member in addition to the strain sensor, the load and the state of the wheel bearing can be measured at one place, and wiring and the like can be simplified. it can.

In the strain sensor, an insulating layer may be formed on the surface of the sensor mounting member by printing and baking, and an electrode and a strain measurement resistor may be formed on the insulating layer by printing and baking.
When the strain sensor is formed as described above, the adhesion strength due to secular change does not decrease as in the case where the strain sensor is fixed to the sensor mounting member by adhesion, so that the reliability of the sensor unit can be improved. . Moreover, since processing is easy, cost reduction can be achieved.

A sensor signal processing circuit unit having a sensor signal processing circuit for processing the output signal of the strain sensor may be provided in the vicinity of the sensor unit.
Providing a sensor signal processing circuit unit in the vicinity of the sensor unit can simplify the wiring work from the sensor unit to the sensor signal processing circuit unit. Further, the sensor signal processing circuit unit can be installed more compactly than when the sensor signal processing circuit unit is provided in a place other than the wheel bearing.

  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 having a double row rolling element interposed between both rolling surfaces and attached to a suspension device to rotatably support the wheel with respect to the vehicle body, the sensor mounting member and the sensor mounting member A sensor unit comprising at least one or more strain sensors is attached to a fixed side member of the outer member and the inner member, and the sensor mounting member has two contact fixing parts for fixing to the fixed side member. The first contact fixing portion of the contact fixing portion is fixed to a suspension device of a vehicle body, and the second contact fixing portion is fixed to the peripheral surface of the fixed side member. Therefore, the load detection sensor is compact in the vehicle. Installation can, and can detect the locked state of the steering moment of the load and the vehicle according to the wheels, and the fixed-side member and the suspension device. Since the sensor mounting member is a simple part that can be mounted on the fixed side member, by attaching a strain sensor to the sensor mounting member, the sensor mounting member can be excellent in mass productivity and cost reduction can be achieved.

  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.

  This sensor-equipped wheel bearing includes an outer member 1 having a double row rolling surface 3 formed on the inner periphery, an inner member 2 having a rolling surface 4 opposed to each of the rolling surfaces 3, and these It is comprised by the double row rolling element 5 interposed between the rolling surfaces 3 and 4 of the outer member 1 and the inner member 2. 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 are arc-shaped in cross section, and each rolling surface 3 and 4 is formed so that the contact angle is outward. Both ends of the bearing space between the outer member 1 and the inner member 2 are sealed by sealing devices 7 and 8, respectively.

  The outer member 1 is a fixed side member, and is formed as an integral part as a whole. The outer member 1 has flanges 1a for attaching to the knuckle 16 of the vehicle body suspension device on the outer peripheral portion, and female threads are cut on the inner periphery at a plurality of circumferential positions (four in this embodiment) of the flange 1a. A vehicle body mounting hole 14 is provided. On the other hand, a stepped knuckle bolt hole 17 is provided at a position corresponding to the vehicle body mounting hole 14 in the knuckle 16. By screwing the knuckle bolt 18 inserted from the knuckle bolt hole 17 side into the vehicle body mounting hole 14, the outer member 1 and the knuckle 16 (suspension device) are fixedly integrated with each other.

  The inner member 2 serves as a rotation 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 inboard side end of the shaft portion 9b of the hub wheel 9. And become. The hub ring 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-fitting holes 15 for hub bolts 19 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 sensor unit 21 shown in FIG. 3 is provided on the outer peripheral portion of the outer member 1. The sensor unit 21 is obtained by attaching a strain sensor 23 for measuring the strain of the sensor attachment member 22 to the sensor attachment member 22. The sensor mounting member 22 includes a first contact fixing portion 22a that is fixed in contact with the knuckle 16, and a second contact fixing portion 22b that is fixed in contact with the outer peripheral surface of the outer member 1. . The strain sensor 23 is disposed at an intermediate portion of the sensor attachment member 22 and attached by an adhesive or the like.

  As shown in FIGS. 1 and 2, the sensor unit 21 is arranged on the upper part of the outer member 1, and the first and second contact fixing portions 22a and 22b of the sensor mounting member 22 are used to form both contact fixing portions 22a. , 22b are fixedly attached to the outer peripheral surface of the knuckle 16 and the outer member 1 with an adhesive or the like so that they are positioned in the same phase in the circumferential direction of the outer member 1. If the positions of the first and second contact fixing portions 22a and 22b are in the same phase in the circumferential direction, the sensor mounting member 22 can be shortened, so that the sensor unit 21 can be easily installed. The axial direction position of the outer member 1 to which the sensor unit 21 is attached is a position near the outboard side end of the outer member 1, for example, a position on the outboard side with respect to the rolling surface 3 of the outboard side row. The sensor mounting member 22 has a shape or material that does not cause plastic deformation by being fixed to the outer member 1.

  Further, the sensor mounting 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 assumed maximum force is the maximum force assumed in traveling that does not lead to vehicle failure. This is because when the sensor mounting member 22 is plastically deformed, the deformation of the outer member 1 is not accurately transmitted to the sensor mounting member 22 and affects the measurement of strain.

The sensor mounting member 22 of the sensor unit 21 can be manufactured by, for example, press working. If the sensor mounting member 22 is a pressed product, the cost can be reduced.
The sensor mounting member 22 may be a sintered metal product by metal powder injection molding. Metal powder injection molding is one of the molding techniques for metals, intermetallic compounds, etc., a step of kneading metal powder with a binder, a step of injection molding using this kneaded product, a step of degreasing the molded body, Including a step of sintering the compact. According to this metal powder injection molding, a sintered body having a higher sintering density than that of general powder metallurgy is obtained, and sintered metal products can be manufactured with high dimensional accuracy, and mechanical strength is also high. There are advantages.

  Various strain sensors 23 can be used. For example, when the strain sensor 23 is composed of a metal foil strain gauge, considering the durability of the metal foil strain gauge, the sensor mounting member 22 can be used even when the expected maximum load is applied to the wheel bearing. It is preferable that the strain amount of the portion where the strain sensor 23 is attached is 1500 microstrain or less. For the same reason, when the strain sensor 23 is composed of a semiconductor strain gauge, the amount of strain is preferably 1000 microstrain or less. Further, when the strain sensor 23 is constituted by a pressure film type sensor, the strain amount is preferably 1500 microstrain or less.

  As shown in FIG. 1, acting force estimating means 31 and abnormality determining means 32 are provided as means for processing the output of the strain sensor 23. These means 31 and 32 may be provided in an electronic circuit device (not shown) on a circuit board or the like attached to the outer member 1 of the wheel bearing, or may be an electric control unit of an automobile. (ECU) may be provided.

  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, the outer member 1 is deformed via the rolling elements 5, and the deformation is transmitted to the outer member 1 and the sensor mounting member 22 fixed to the knuckle 16, and the sensor mounting member 22. Is deformed. The strain of the sensor mounting member 22 is measured by the strain sensor 23. The sensor mounting member 22 is weaker than the outer member 1, and the strain sensor 23 measures the strain of the weak sensor mounting member 22, so that a strain larger than the strain of the outer member 1 is obtained, and the sensitivity is high. The distortion of the outer member 1 can be detected.

  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. From the relationship between the strain and the load obtained and set in advance through experiments and simulations, the acting force estimation means 31 is configured so that the external force acting on the wheel bearing or the distance between the tire and the road surface is determined by the output of the strain sensor 23. Is calculated. The abnormality determining means 32 outputs an abnormal signal to the outside when it is determined that the external force acting on the wheel bearing calculated by the acting force estimating means 31 or the acting force between the tire and the road surface exceeds an allowable value. Output. This abnormal signal can be used for vehicle control of an automobile. Further, 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.

  The sensor unit 21 of this embodiment has a configuration in which only one strain sensor 23 is mounted on the sensor mounting member 22, but a configuration in which a plurality of strain sensors 23 are mounted on the sensor mounting member 22 may be employed. If a plurality of strain sensors 23 are attached to the sensor attachment member 22, it becomes possible to detect a load with higher accuracy.

  Further, in this embodiment, the sensor unit 21 is arranged at only one upper portion of the outer member 1. However, as shown in FIG. 4, the sensor unit 21 is provided at a plurality of locations at the upper and lower portions of the outer member 1. It is good also as a structure arrange | positioned. If the sensor units 21 are arranged at a plurality of locations, it becomes possible to detect a load with higher accuracy. Depending on the case, the sensor unit 21 may be arranged only at one lower portion of the outer member 1.

  5 and 6 show different embodiments. In this wheel bearing, the sensor mounting member 22 and the outer member 1 are fixed using bolts. As shown in FIG. 6, the sensor mounting member 22 has the same overall shape as the sensor mounting member 22 shown in FIG. 3, and an axial bolt insertion hole 40 is formed in the first contact fixing portion 22a. A radial bolt insertion hole 41 is formed in the second contact fixing portion 22b. Bolt screw holes 42 and 43 having internal threads formed on the inner peripheral surface are formed in the peripheral surfaces of the knuckle 16 and the outer member 1 at positions corresponding to the bolt insertion holes 40 and 41, respectively. As shown in FIG. 5, in the sensor unit 21, the bolts 44 are inserted into the bolt insertion holes 40, 41 of the sensor mounting member 22 from the outer peripheral side (more precisely, the bolts 44 are inserted from the outboard side with respect to the bolt insertion holes 40. The screw 44 is fixed to the knuckle 16 and the outer member 1 by screwing the male screw portion 44a of the bolt 44 into the bolt screw holes 42 and 43.

For fixing the sensor attachment member 22 to the knuckle 16 and the outer member 1, either an adhesive or a bolt may be used. Moreover, you may use both together. Furthermore, you may fix the sensor attachment member 22 and the outward member 1 by welding, without using an adhesive agent and a volt | bolt.
Regardless of which of these fixing structures is employed, the sensor mounting member 22 and the outer member 1 can be firmly fixed. Therefore, the sensor mounting member 22 is not displaced with respect to the outer member 1, and the deformation of the outer member 1 can be accurately transmitted to the sensor mounting member 22.

  FIG. 7 shows a different embodiment of the sensor unit. The sensor unit 21 is provided with a temperature sensor 24 in addition to the strain sensor 23. The shape of the sensor mounting member 22 is the same as that shown in FIG. 3, and both the strain sensor 23 and the temperature sensor 24 are arranged at the center of the sensor mounting member 22. As the temperature sensor 24, for example, a platinum resistance thermometer, a thermocouple, or a thermistor can be used. Furthermore, a sensor capable of detecting a temperature other than these can also be used.

  Also in the axle bearing provided with the sensor unit 21, the strain sensor 23 detects the strain of the sensor mounting member 22, and measures the load applied to the wheel by the strain. By the way, the temperature of the wheel bearing changes during use, and the temperature change affects the strain of the sensor mounting member 22 or the operation of the strain sensor 23. Therefore, the temperature sensor 24 arranged on the sensor mounting member 22 detects the temperature of the sensor mounting member 22 and corrects the output of the strain sensor 23 based on the detected temperature, thereby removing the influence of the temperature of the strain sensor 23. be able to. Thereby, it is possible to detect the load with high accuracy.

FIG. 8 shows a further different embodiment of the sensor unit. The sensor unit 21 is provided with various sensors 25 separately from the strain sensor 23. The various sensors 25 are at least one of an acceleration sensor and a vibration sensor. The shape of the sensor mounting member 22 is the same as that shown in FIG. 3, and the strain sensor 23 and the various sensors 25 are both disposed at the center of the sensor mounting member 22.
Thus, when the strain sensor 23 and the various sensors 25 are attached to the sensor attachment member 22, the load and the state of the wheel bearing can be measured at one place, and wiring and the like can be simplified.

  FIG. 9 shows a structure of a sensor unit in which a strain sensor is formed by a method different from that in each of the embodiments. In this sensor unit 21, an insulating layer 50 is formed on the sensor mounting member 22, and a pair of electrodes 51, 52 are formed on both sides of the surface of the insulating layer 50. A strain measuring resistor 53 serving as a strain sensor is formed on the layer 50, and a protective film 54 is further formed on the electrodes 51 and 52 and the strain measuring resistor 53.

  A method for manufacturing the sensor unit 21 will be described below. First, the insulating layer 50 is formed by printing and baking an insulating material such as glass on the surface of the sensor mounting member 22 formed of a metal material such as stainless steel. Next, a conductive material is printed and baked on the surface of the insulating layer 50 to form the electrodes 51 and 52. Furthermore, a strain measurement resistor 53 is formed by printing and baking a material to be a resistor between the electrode 51 and the electrode 52. Further, a protective film 54 is formed to protect the electrodes 51 and 52 and the strain measuring resistor 53.

  Usually, the strain sensor is fixed to the sensor mounting member 22 by bonding. However, this fixing structure may affect the detection of the strain sensor due to a decrease in bonding strength due to aging. It is also a cause. On the other hand, as in this embodiment, the insulating layer 50 is formed on the surface of the sensor mounting member 22 by printing and baking, and the electrodes 51 and 52 and the strain measurement resistor serving as the strain sensor are formed on the insulating layer 50. When the sensor unit 21 is formed by printing and baking 53, it is possible to improve reliability and reduce costs.

  10 to 12 show a further different embodiment. This wheel bearing incorporates a sensor signal processing circuit unit 60 for processing the outputs of the strain sensors provided in the sensor unit 21 and the aforementioned sensors (temperature sensor, acceleration sensor, vibration sensor). The sensor signal processing circuit unit 60 is attached to the outer peripheral surface of the outer member 1.

  The sensor signal processing circuit unit 60 has a circuit board 62 made of glass epoxy or the like in a housing 61 made of resin or the like, and the output signal of the strain sensor 23 is processed on the circuit board 62. An operational amplifier, a resistor, a microcomputer, etc., and a power supply electric / electronic component 63 for driving the strain sensor 23 are arranged. In addition, a joint portion 64 that joins the wiring of the strain sensor 23 and the circuit board 62 is provided. Further, it has a cable 65 for supplying power from the outside and outputting an output signal processed by the sensor signal processing circuit to the outside. When the sensor unit 21 is provided with each of the above-described sensors (temperature sensor, acceleration sensor, vibration sensor), the sensor signal processing circuit unit 60 includes a circuit board 62, an electric / electronic component 63, a joint corresponding to each sensor. A portion 64, a cable 65, and the like are provided.

  In general, a sensor signal processing circuit unit for processing the output of each sensor provided in a wheel bearing is provided in an electric control unit (ECU) of an automobile. As in this embodiment, a sensor in a wheel bearing is provided. By providing the sensor signal processing circuit unit 60 in the vicinity of the unit 21, labor for wiring from the sensor unit 21 to the sensor signal processing circuit unit 60 can be simplified, and the sensor signal processing circuit unit 60 is provided at a place other than the wheel bearing. The sensor signal processing circuit unit 60 can be installed more compactly than the case of providing the sensor.

  FIG. 13 and FIG. 14 show an embodiment in which the arrangement location of the sensor unit 21 is different from the above embodiments. In each of the above embodiments, the sensor unit 21 at the upper part, the lower part, or both the upper and lower parts of the outer member 1 is arranged. Is arranged. As shown in FIG. 13, as means for processing the output of the strain sensor 23, moment estimating means 33 is provided instead of the acting force estimating means 31 in the above embodiment. Other than this, the configuration is the same as that of the embodiment of FIGS. 1 to 3, and thus the same components are denoted by the same reference numerals and description thereof is omitted.

  Also in this embodiment, when a load is applied to the hub wheel 9, the outer member 1 is deformed via the rolling elements 5, and the deformation is a sensor mounting member 22 fixed to the outer member 1 and the knuckle 16. The sensor mounting member 22 is deformed. The strain of the sensor mounting member 22 is measured by the strain sensor 23. The sensor mounting member 22 is weaker than the outer member 1, and the strain sensor 23 measures the strain of the weak sensor mounting member 22, so that a strain larger than the strain of the outer member 1 is obtained, and the sensitivity is high. The distortion of the outer member 1 can be detected.

  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 steering moment acting on the wheel bearing can be calculated. The steering moment is a moment applied to the vehicle bearing when the vehicle travels on a curved path. The moment estimation means 33 calculates the steering moment acting on the wheel bearing based on the output of the strain sensor 23 from the relationship between the strain and the load obtained and set in advance through experiments and simulations. Based on this, the abnormality determination means 32 outputs an abnormality signal to the outside when it is determined that the steering moment acting on the wheel bearing exceeds the allowable value. This abnormal signal can be used for vehicle control of an automobile. Further, if the steering moment acting on the wheel bearing is output in real time, more detailed vehicle control becomes possible.

  In this embodiment, the sensor unit 21 is arranged at only one front portion of the outer member 1 in the vehicle traveling direction. However, as shown in FIG. Alternatively, the sensor unit 21 may be arranged. If the sensor units 21 are arranged in a plurality of places as described above, it is possible to detect the steer moment with higher accuracy. In some cases, the sensor unit 21 may be disposed only at one rear portion of the outer member 1.

In each of the above embodiments, the case where the outer member 1 is a fixed side member has been described. However, the present invention can also be applied to a wheel bearing in which the inner member is a fixed side member. The sensor unit 21 is provided between the inner circumferences of the inner member.
In each of the above embodiments, the case where the present invention is applied to a third generation type wheel bearing has been described. However, the present invention is applicable to a first or second generation type wheel in which the bearing portion and the hub are independent parts. The present invention can also be applied to a bearing or 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 a figure showing combining the sectional view of the wheel bearing with a sensor concerning the embodiment of this invention, and the block diagram of the conceptual composition of the detection system. It is a front view which shows the outward member and sensor unit of the wheel bearing with a sensor. (A) is a front view of the sensor unit, and (B) is a side view thereof. It is a front view which shows the outward member and sensor unit of a different wheel bearing with a sensor. It is sectional drawing of the bearing for wheels with a sensor concerning different embodiment of this invention. (A) is a top view of the sensor unit of the wheel bearing with a sensor, (B) is the VIB-VIB sectional drawing. (A) is a top view of a different sensor unit, (B) is the side view. (A) The top view of a different sensor unit, (B) is the side view. It is a figure which shows the cross-section of another sensor unit. It is sectional drawing of the bearing for wheels with a sensor concerning further different embodiment of this invention. It is a front view which shows the outward member and sensor unit of the wheel bearing with a sensor. It is a top view of a sensor signal processing circuit unit. It is a figure showing combining the sectional view of the bearing for wheels with a sensor concerning still another embodiment of this invention, and the block diagram of the conceptual composition of the detection system. It is a front view which shows the outward member and sensor unit of the wheel bearing with a sensor. (A) is a plan view of the sensor unit, and (B) is a side view thereof.

Explanation of symbols

1 ... Outer member (fixed side member)
2 ... Inward member (rotary member)
3, 4 ... rolling surface 5 ... rolling elements 7, 8 ... sealing device 16 ... knuckle (suspension device)
DESCRIPTION OF SYMBOLS 18 ... Knuckle bolt 21 ... Sensor unit 22 ... Sensor attachment member 22a ... 1st contact fixing part 22b ... 2nd contact fixing part 23 ... Strain sensor 24 ... Temperature sensor 25 ... Various sensors 31 ... Action force estimation means 32 ... Abnormality Determination means 33 ... Moment estimation means 50 ... Insulating layers 51, 52 ... Electrodes 53 ... Strain measuring resistor 54 ... Protective film 60 ... Sensor signal processing circuit unit 61 ... Housing 62 ... Circuit board 63 ... Electric / electronic component 64 ... Join Part 65 ... Cable

Claims (14)

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 A rolling bearing, and a wheel bearing that is attached to a suspension device and rotatably supports the wheel with respect to the vehicle body,
A sensor unit comprising a sensor attachment member and at least one strain sensor attached to the sensor attachment member is attached to a fixed side member of the outer member and the inner member, and the sensor attachment member is a fixed side member The first contact fixing part is fixed to the suspension device of the vehicle body, and the second contact fixing part is the above-mentioned contact fixing part. A sensor-equipped bearing for wheels, wherein the bearing is fixed to a peripheral surface of a stationary member.   The sensor-equipped wheel bearing according to claim 1, wherein the sensor unit is disposed on an upper portion, a lower portion, or both upper and lower sides of the fixed side member.   The sensor-equipped wheel bearing according to claim 1, wherein the sensor unit is disposed at a front portion, a rear portion, or both front and rear in the vehicle traveling direction of the fixed side member.   4. The second contact fixing portion of the sensor mounting member according to claim 1, wherein the second contact fixing portion of the sensor mounting member has a circumferential direction in phase with the first contact fixing portion in the circumferential direction of the fixing side member. The wheel bearing with a sensor fixed to the surrounding surface of the said fixed side member used as a position.   5. The wheel bearing with sensor according to claim 1, wherein the fixed side member is an outer member. 6.   6. The sensor-equipped wheel according to claim 1, further comprising an acting force estimating unit that estimates an external force acting on a wheel bearing or an acting force between a tire and a road surface based on an output of the strain sensor. Bearings.   In any one of claims 1 to 6, even in a state in which an assumed maximum force is applied as an external force acting on the stationary member or an acting force acting between the tire and a road surface. A sensor-equipped wheel bearing wherein the sensor mounting member of the sensor unit is not plastically deformed.   The sensor-equipped wheel bearing according to any one of claims 1 to 7, wherein the sensor mounting member is a press-processed product.   The wheel bearing with a sensor according to any one of claims 1 to 7, wherein the sensor mounting member is a sintered metal by metal injection molding.   In any one of Claims 1 thru | or 9, the said sensor attachment member and the said suspension apparatus are fixed using either a volt | bolt and an adhesive agent, or performing both together, or Wheel bearing with sensor that is performed by welding.   11. The wheel bearing with sensor according to claim 1, wherein a temperature sensor is provided on the sensor mounting member.   12. The sensor-equipped wheel bearing according to claim 1, wherein the sensor mounting member is provided with at least one of an acceleration sensor and a vibration sensor.   13. The strain sensor according to claim 1, wherein the strain sensor is formed by printing and baking an insulating layer on a surface of the sensor mounting member, and an electrode and a strain measuring resistor are formed on the insulating layer. Sensor-equipped wheel bearing formed by printing and firing.   14. The sensor-equipped wheel bearing according to claim 1, wherein a sensor signal processing circuit unit having a sensor signal processing circuit for processing an output signal of the strain sensor is provided in the vicinity of the sensor unit.

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