JP4931537B2 - Wheel bearing device with in-wheel motor built-in sensor - Google Patents

Description

  The present invention relates to an in-wheel motor-equipped wheel bearing device in which a hub bearing, a speed reducer, and an electric motor are combined, and more particularly to a device provided with a sensor that detects a load applied to the hub bearing.

As a wheel bearing device for a vehicle such as an electric vehicle, an in-wheel type motor-integrated wheel bearing device in which a hub bearing, a speed reducer, and an electric motor are combined has attracted attention (for example, Patent Documents 1 and 2). When this in-wheel type motor-equipped wheel bearing device is used as a driving wheel of an electric vehicle, each driving wheel can be individually driven to rotate, so that a large-scale power transmission mechanism such as a propeller shaft and a differential is not required. Can be made lighter and more compact.
JP 2005-7914 A JP-A-5-332401 (FIGS. 1-3)

  When putting in-wheel motor-equipped wheel bearing devices into practical use, it is of course essential to measure the rotational speed of each wheel for traveling speed control, etc. It is also conceivable to measure the load acting on each wheel during vehicle travel and to control the vehicle attitude from the measurement result. 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, 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.

  The acting force acting on the contact point between the wheel and the road surface when the vehicle travels includes a vertical force, a horizontal force, and a longitudinal force. These triaxial forces all affect the running of the vehicle, but in particular the longitudinal force is largely related to the braking of the brake, so it is important to detect this with high accuracy. It is very important for stable driving and safe driving.

The purpose of this invention is made compact install sensors for detecting load on the vehicle, in-wheel type which can accurately detect the longitudinal force acting on the ground contact point of the car wheels and the road surface for use in attitude control of the vehicle A wheel bearing device with a motor built-in sensor is provided.

The in-wheel motor-equipped sensor-equipped wheel bearing device according to the present invention is a rolling type in which an output shaft of an electric motor and a vehicle wheel hub are connected coaxially via a speed reducer or directly and support the hub. In the wheel bearing device provided with a brake for braking the rotation of the hub, the vertical direction, the left-right direction, and the front-rear direction, which are perpendicular to each other, act on the grounding point of the wheel mounted on the hub and the road surface of the three axial forces, a force in the longitudinal direction, the only setting the longitudinal direction acting force estimation means for both whether we estimate the braking force of the electric motor current and the braking force of the estimated longitudinal direction It is used for attitude control of vehicles .

The amount of current flowing through the electric motor varies depending on the magnitude of the acting force in the front-rear direction that acts on the contact points between the wheels and the road surface when the vehicle is traveling. Similarly, the braking force of the brake varies depending on the magnitude of the acting force in the front-rear direction. Therefore, if the relationship between the acting force in the front-rear direction and the current of the electric motor and the braking force of the brake is obtained in advance through experiments and simulations, the action in the front-rear direction can be determined by measuring the current of the electric motor and the braking force of the brake. The force can be estimated. Although it is possible to estimate the acting force in the front-rear direction from a single measurement result of the electric motor current or the braking force of the brake, it is possible to accurately estimate the acting force in the front-rear direction by comparing and contrasting the two. Can do.
The front-rear direction acting force estimation means estimates the front-rear direction acting force from the relationship between the front-rear direction acting force determined in advance through experiments and simulations, the electric motor current, and the braking force of the brake. To do. Acting force in the longitudinal direction obtained by estimation is used your the attitude system of the vehicle. Thereby, advanced vehicle control becomes possible.

In this invention, the pressing force measuring means for measuring the pressing force between the brake rotor and the brake pad is provided, and the braking force of the brake can be obtained from the pressing force output from the pressing force measuring means. The pressing force measuring means preferably obtains the pressing force between the brake rotor and the brake pad from the hydraulic pressure of the brake fluid. In that case, for example, a hydraulic pressure gauge can be used as the pressing force measuring means. Further, the pressing force measuring means may determine a pressing force between the brake rotor and a brake pad from deformation of a brake caliper. In that case, for example, a strain sensor can be used as the pressing force measuring means.
In either case, the pressing force can be measured simply by attaching a pressing force measuring means such as a hydraulic pressure gauge or a strain sensor. Therefore, a sensor for measuring the braking force of the brake can be installed compactly in the vehicle. it can.

In this invention, the braking force of the brake can be obtained from the detection signal of the deformation of the brake components. The brake component for obtaining the deformation detection signal may be a brake caliper. In that case, for example, a strain sensor can be used to detect deformation of the brake caliper.
Since the brake caliper is the detection target for detecting the deformation of the brake components, for example, simply by attaching a strain sensor to the brake caliper, a detection signal for the deformation of the brake components can be obtained, and the braking force of the brake It is possible to install a sensor for measuring the vehicle in a compact manner.

In this invention, the braking force of the brake can be obtained from the detection signal of the deformation of the components of the suspension device. The component of the suspension device that obtains the deformation detection signal may be a knuckle. In that case, for example, a strain sensor can be used to detect the deformation of the knuckle.
Since the detection target for detecting the deformation of the suspension component is a knuckle, for example, simply by attaching a strain sensor to the knuckle, a detection signal for the deformation of the suspension component can be obtained, and the braking force of the brake It is possible to install a sensor for measuring the vehicle in a compact manner.

In the present invention, the braking force of the brake can be obtained from the detection signal of the relative displacement between the brake component and the suspension device component. The brake component for determining the relative displacement may be a brake caliper. Moreover, the component part of the suspension apparatus which calculates | requires the said relative displacement is good in it being a knuckle. In that case, for example, a displacement sensor can be used to detect the relative displacement of the brake caliper relative to the suspension component and to detect the relative displacement of the knuckle relative to the brake component.
When the detection target for detecting the deformation of the brake component is a brake caliper and the detection target for detecting the deformation of the suspension component is a knuckle, for example, a strain sensor is attached to the knuckle or the brake caliper. The detection signal of the relative displacement between the components of the brake and the components of the suspension device can be obtained simply, and a sensor for measuring the braking force of the brake can be compactly installed in the vehicle.

The in-wheel motor-equipped sensor-equipped wheel bearing device according to the present invention is a rolling type in which an output shaft of an electric motor and a vehicle wheel hub are connected coaxially via a speed reducer or directly and support the hub. In the wheel bearing device provided with a brake for braking the rotation of the hub, the vertical direction, the left-right direction, and the front-rear direction, which are perpendicular to each other, act on the grounding point of the wheel mounted on the hub and the road surface 3 out of axial forces, the longitudinal force, due to the provision of the longitudinal direction acting force estimation means for both whether we estimate the braking force of the current and the brake of the electric motor, acts on the ground contact point of the wheel and the road surface of the It made accurately detect the front-rear direction of the force is used to the attitude control of the vehicle, allowing sophisticated vehicle control by Re it.

  A pressing force measuring means for measuring the pressing force between the brake rotor and the brake pad is provided, and the braking force of the brake is obtained from the pressing force output from the pressing force measuring means, or deformation of the brake components is detected. The braking force of the brake is determined from the signal, or the braking force of the brake is determined from the detection signal of the relative displacement between the brake component and the suspension component, or the brake component and the suspension device. By detecting the braking force of the brake from the detection signal of the relative displacement with the component, the load detection sensor can be installed in the vehicle in a compact manner.

  A first embodiment of the present invention will be described with reference to FIGS. This in-wheel type sensor-equipped wheel bearing device with a built-in in-wheel motor includes a hub bearing A that rotatably supports a wheel hub, an electric motor B as a rotational drive source, and a speed reduction of the rotation of the electric motor B. The transmission speed reducer C is arranged on the same central axis O, and is assembled to the vehicle body together with a brake D that applies a braking force to the hub. In this embodiment, the hub bearing A is a third generation type inner ring rotating type in which the inner member of the bearing forms part of the hub. 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 FIG. 1, the hub bearing A includes an outer member 1 in which double-row rolling surfaces 3 are formed on the inner periphery, and an inner member in which rolling surfaces 4 that face the respective rolling surfaces 3 are formed. 2 and double row rolling elements 5 interposed between the rolling surfaces 3 and 4 of the outer member 1 and the inner member 2. The hub bearing A is a double-row angular ball bearing type, and the rolling elements 5 are formed 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. The end of the bearing space between the outer member 1 and the inner member 2 is sealed with a seal member 7.

  The outer member 1 is a stationary raceway, and has a flange 1a attached to the casing 33b on the outboard side of the speed reducer C on the outer periphery, and the whole is an integral part. The flange 1a is provided with bolt insertion holes 14 at a plurality of locations in the circumferential direction. Further, the casing 33b is provided with a bolt screw hole 44 whose inner periphery is threaded at a position corresponding to the bolt insertion hole 14. The outer member 1 is attached to the casing 33b by screwing the attachment bolt 15 inserted into the bolt insertion hole 14 into the bolt screw hole 44.

  The inner member 2 is a rotating raceway, and the outboard side member 9 having a hub flange 9a for attaching a wheel and a brake is fitted to the outer periphery of the outboard side member 9. It consists of the inboard side material 10 integrated with the outboard side material 9 by caulking. The rolling surface 4 of each said row | line | column is formed in these outboard side materials 9 and inboard side materials 10. FIG. A through hole 11 is provided at the center of the inboard side member 10. The hub flange 9a is provided with insertion holes 17 for hub bolts 16 at a plurality of locations in the circumferential direction. In the vicinity of the base portion of the hub flange 9a of the outboard side member 9, a cylindrical pilot portion 13 that guides the wheel 19 of the wheel and the brake rotor 56 of the brake D protrudes toward the outboard side. A cap 18 that closes the outboard side end of the through hole 11 is attached to the inner periphery of the pilot portion 13.

  The electric motor B is an axial gap type in which an axial gap is provided between a stator 23 fixed to a cylindrical casing 22 and a rotor 25 attached to an output shaft 24. The output shaft 24 is cantilevered by two bearings 26 on the cylindrical portion of the casing 33a on the inboard side of the reduction gear C. The inboard side end of the gap between the output shaft 24 and the casing 33 a is sealed with a seal member 27. A cap 28 is attached to the opening on the inboard side of the casing 22. An ammeter 29 for detecting a current value flowing through the electric motor B is provided.

  As shown in FIGS. 1 and 2, the speed reducer C is configured as a cycloid speed reducer. In other words, the speed reducer C has two curved plates 34a and 34b formed with wavy trochoidal curves having a gentle outer shape, mounted on the eccentric portions 32a and 32b of the input shaft 32 via bearings 35, respectively. A plurality of outer pins 36 passed to the casing 33b guide the eccentric movement of the curved plates 34a, 34b on the outer peripheral side, and a plurality of inner pins 38 attached to the inboard side member 10 of the inner member 2 The curved plates 34a and 34b are inserted into and engaged with a plurality of through holes 39 provided inside the curved plates 34a and 34b. The input shaft 32 is spline-coupled with the output shaft 24 of the electric motor B so as to rotate integrally. The input shaft 32 is supported at both ends by two bearings 40 on the casing 33a on the inboard side and the inner diameter surface of the inboard side member 10 of the inner member 2.

  When the output shaft 24 of the electric motor B rotates, the curved plates 34a and 34b attached to the input shaft 32 that rotates integrally with the output shaft 24 perform an eccentric motion. The eccentric motion of each of the curved plates 34a and 34b is transmitted as rotational motion to the inner member 2 which is a wheel hub by the engagement of the inner pin 38 and the through hole 39. The rotation of the inner member 2 is decelerated with respect to the rotation of the output shaft 24. For example, a reduction ratio of 1/10 or more can be obtained with a single-stage cycloid reducer.

  The two curved plates 34a and 34b are mounted on the eccentric portions 32a and 32b of the input shaft 32 so that the vibrations caused by the eccentric motion are canceled out from each other, and are mounted on both sides of the eccentric portions 32a and 32b. The counterweights are eccentric in the direction opposite to the eccentric direction of the eccentric parts 32a, 32b so as to cancel the vibration caused by the inertial couple around the axis orthogonal to the rotation axis generated by the eccentric movement of the curved plates 34a, 34b. 41 is attached.

  As shown in FIG. 3, bearings 42 and 43 are mounted on the outer pins 36 and the inner pins 38. The outer rings 42a and 43a of the bearings 42 and 43 are respectively connected to the outer circumferences of the curved plates 34a and 34b and the outer rings 42a and 34b, respectively. It comes into rolling contact with the inner periphery of the through hole 39. Therefore, the contact resistance between the outer pin 36 and the outer periphery of each curved plate 34a, 34b and the contact resistance between the inner pin 38 and the inner periphery of each through hole 39 are reduced, and the eccentric motion of each curved plate 34a, 34b is smooth. Can be transmitted to the inner member 2 as a rotational motion.

  This wheel bearing device is assembled to the vehicle body together with the brake D via a knuckle 45 of a suspension device attached to the outer periphery of the casing 33b of the speed reducer C or the casing 22 of the electric motor B. In this embodiment, the knuckle 45 is attached to the casing 22 of the electric motor B.

As shown in FIG. 1, the brake D applies a braking force by sandwiching a brake rotor 56 between a pair of brake pads 55, 55 provided in a brake caliper 51. The brake rotor 56 is provided between the tire wheel 19 and the hub flange 9 a of the inner member 2. The brake caliper 51 is installed on a brake support member 45a fixed to the knuckle 45 of the suspension device.
Inside the brake caliper 51 is provided a cylinder chamber that accommodates the piston 54 so as to be able to advance and retreat by the hydraulic pressure of the brake fluid, and the brake pads 55 and 55 are attached to the piston 54. The cylinder chamber in the brake caliper 51 is supplied with the hydraulic pressure of the brake fluid via a brake pipe (or brake hose) 59 from a master cylinder 58 that has one end of the depression force of the brake pedal 57 to the hydraulic pressure of the brake fluid.

  A hydraulic pressure gauge 52 for measuring the hydraulic pressure of the brake fluid is provided at an arbitrary position in the path of the brake fluid from the master cylinder 58 through the brake pipe 59 into the brake caliper 51. The hydraulic pressure gauge 52 is a pressing force measuring unit that measures the pressing force between the brake rotor 56 and the brake pads 55 and 55. By obtaining the relationship between the hydraulic pressure of the brake fluid and the pressing force in advance through experiments and simulations, the pressing force can be detected from the hydraulic pressure.

  The ammeter 29 of the electric motor B and the hydraulic pressure gauge 52 of the brake D process these measured values to estimate the longitudinal force acting on the ground contact point between the wheel and the road surface. Is connected. In addition, an abnormality determination unit 61 is connected to the front-rear direction acting force estimation unit 60. These means 60 and 61 may be provided in an electronic circuit device (not shown) such as a circuit board attached to the wheel bearing device, or may be provided in an electric control unit (ECU) of an automobile. It may be.

  The operation of the in-wheel motor-equipped sensor-equipped wheel bearing device having the above-described configuration will be described. When the electric motor B is driven to rotate, the rotation of the output shaft 24 of the electric motor B is decelerated and transmitted to the inward member 2 that is a wheel hub via the speed reducer C, and the vehicle rotates to rotate the wheel. . When the vehicle travels, a force is applied to the wheel from the contact point between the wheel and the road surface. The force is a combination of forces in the three-axis directions of the vertical direction, the horizontal direction, and the front-rear direction orthogonal to each other. The force in the front-rear direction is estimated by the front-rear direction acting force estimation means 60. The principle is shown below.

  The amount of current flowing through the electric motor B varies depending on the magnitude of the acting force in the front-rear direction that acts on the contact point between the wheel and the road surface when the vehicle is traveling. Similarly, the braking force of the brake D varies depending on the magnitude of the acting force in the front-rear direction. Therefore, if the relationship between the front-rear direction acting force and the current of the electric motor B and the braking force of the brake D is obtained in advance through experiments and simulations, by measuring the current of the electric motor B and the braking force of the brake D, The acting force in the front-rear direction can be estimated. Although it is possible to estimate the acting force in the front-rear direction from a single measurement result of the current of the electric motor B or the braking force of the brake D, it is possible to accurately estimate the acting force in the front-rear direction by comparing and comparing the two. can do.

The front / rear direction acting force estimation means 60 acts in the front / rear direction based on the relationship between the acting force in the front / rear direction determined in advance through experiments and simulations, the current of the electric motor B, and the braking force of the brake D. Estimate force. Acting force in the longitudinal direction obtained by estimation is used your the attitude system of the vehicle. Thereby, advanced vehicle control becomes possible. The abnormality determining unit 61 outputs an abnormality signal to the outside when it is determined that the front-rear direction acting force estimated by the front-rear direction acting force estimating unit 60 exceeds the allowable value. This abnormal signal can also be used for vehicle attitude control and the like. Furthermore, if the front-rear direction acting force acting on the contact point between the wheel and the road surface is output in real time, more precise posture control becomes possible.

  In the case of this embodiment, the pressing force between the brake rotor 56 and the brake pads 55 and 55 can be measured by measuring the hydraulic pressure of the brake fluid simply by attaching the hydraulic pressure gauge 52 to an arbitrary place in the brake fluid path. it can. For this reason, the sensor for measuring the braking force of the brake D can be compactly installed in the vehicle.

As the pressing force measuring means, a strain sensor 53A attached to the brake caliper 51 as shown in FIG. In this case, the deformation of the brake caliper 51 caused by the pressing force acting between the brake rotor 56 and the brake pad 55 is measured by the strain sensor 53A, and the pressing force is obtained from the deformation amount. The direction of deformation to be measured is a direction in which the brake pad 55 is pressed against the brake rotor 56. By determining the relationship between the deformation of the brake caliper 51 and the pressing force in advance through experiments and simulations, the pressing force can be detected from the output of the strain sensor 53A.
In this case, the pressing force between the brake rotor 56 and the brake pads 55 and 55 can be measured only by attaching the strain sensor 53A to the brake caliper 51. For this reason, the sensor for measuring the braking force of the brake D can be compactly installed in the vehicle.

The braking force of the brake D can be obtained from other than the pressing force between the brake rotor 56 and the brake pads 55 and 55. For example, it is obtained by measuring the deformation of the components of the brake D. In that case, as shown in FIG. 5, the deformation of the brake caliper 51 may be detected by a strain sensor 53A.
By using the brake caliper 51 as a detection target for detecting the deformation of the components of the brake D, it is possible to obtain a deformation detection signal of the components of the brake D simply by attaching the strain sensor 53A to the brake caliper 51. . For this reason, the sensor for measuring the braking force of the brake D can be compactly installed in the vehicle.

Also, the braking force of the brake D can be obtained by measuring the deformation of the components of the suspension device. In that case, as shown in FIG. 6, the deformation of the knuckle 45 (exactly the brake support member 45a) of the suspension device may be detected by the strain sensor 53A.
By using the knuckle 45 as a detection target for detecting deformation of the suspension device components, a detection signal for deformation of the suspension device components can be obtained simply by attaching the strain sensor 53A to the brake support member 45a. . For this reason, the sensor for measuring the braking force of the brake D can be compactly installed in the vehicle.

Furthermore, the braking force of the brake D can also be obtained by measuring the relative displacement between the components of the brake D and the components of the suspension device. In this case, as shown in FIG. 7 or FIG. 8, the relative displacement between the brake caliper 51 of the brake D and the knuckle 45 (more precisely, the brake support member 45a) of the suspension device may be detected by a displacement sensor 53B. FIG. 7 shows a case where the relative displacement is measured by the displacement sensor 53B attached to the knuckle 45, and FIG. 8 shows a case where the relative displacement is measured by the displacement sensor 53B attached to the brake caliper 51.
A brake caliper 51 is used as a component of the brake D for obtaining the relative displacement, and a knuckle 45 is used as a component of the suspension device for obtaining the relative displacement, whereby the displacement sensor 53B is attached to the brake support member 45a of the knuckle 45 or the brake caliper 51. Only the relative displacement between the components of the brake D and the components of the suspension device can be obtained. For this reason, the sensor for measuring the braking force of the brake D can be compactly installed in the vehicle.

  FIG. 9 shows a second embodiment of the present invention. In this embodiment, the electric motor B is a radial gap type in which a radial gap is provided between a stator 103 fixed to the casing 102 and a rotor 105 attached to the output shaft 104. The output shaft 104 is splined to the input shaft 32 of the speed reducer C. Except for the electric motor B, the configuration is the same as that of the first embodiment. In the second embodiment, as in the case of the first embodiment, the current of the electric motor B is measured by an ammeter (not shown), and a hydrometer, a strain sensor, a displacement sensor, etc. (not shown) ) And the braking force of the brake D can be measured, and the longitudinal force acting on the contact point between the wheel and the road surface can be estimated from the measurement results by the longitudinal acting force estimation means (not shown). Thereby, advanced vehicle control becomes possible.

  FIG. 10 shows a third embodiment of the present invention. In this embodiment, the speed reducer C is a planetary speed reducer. The electric motor B is a radial gap type as in the second embodiment. In the planetary reduction gear C, a sun gear 113 is integrally provided on the outer periphery of the input shaft 112, and a plurality of planetary gears 115 meshing with the sun gear 113 and the inner teeth 114 provided on the inner periphery of the outboard casing 33b of the reduction gear. Is rotatably supported by an inner pin 118 attached to the inboard side member 10 of the inner member 2. Also with this planetary reduction gear, the rotation of the output shaft 104 of the electric motor B can be decelerated and transmitted to the inner member 2 that is a hub. However, the reduction ratio is not as great as that of the cycloid reducer. In the third embodiment as well, the current of the electric motor B is measured with an ammeter (not shown), and the braking force of the brake D is measured with a hydraulic pressure gauge, a strain sensor, a displacement sensor, etc. (not shown). From the measurement results, the longitudinal force acting on the contact point between the wheel and the road surface can be estimated by the longitudinal force estimation means (not shown). Thereby, advanced vehicle control becomes possible.

In each of the embodiments described above, the output of the electric motor B is decelerated by the reduction gear C and transmitted to the wheel hub. However, without providing the reduction gear C, the output shaft of the electric motor B and the wheel It is good also as a structure which connects with the hub 2 directly.
In each of the above embodiments, the case where the hub bearing A is applied to a wheel bearing device of the third generation type has been described. However, in the present invention, the inner member of the hub bearing A and the wheel hub are independent of each other. The present invention can also be applied to a first or second generation type wheel bearing device. Further, the present invention can be applied to a wheel bearing device in which the hub bearing A is a tapered roller type of each generation type.

It is sectional drawing of the wheel bearing apparatus with a sensor with a built-in in-wheel type motor concerning 1st Embodiment of this invention. It is II-II sectional drawing of FIG. It is sectional drawing which expands and shows the principal part of FIG. It is sectional drawing of a brake. It is sectional drawing of a different brake. Furthermore, it is sectional drawing of a different brake. Furthermore, it is sectional drawing of a different brake. Furthermore, it is sectional drawing of a different brake. It is sectional drawing of the wheel bearing apparatus with an in-wheel type motor built-in sensor concerning 2nd Embodiment of this invention. It is sectional drawing of the bearing apparatus for wheels with a sensor with a built-in in-wheel type motor concerning 3rd Embodiment of this invention.

Explanation of symbols

1 ... Outer member 2 ... Inner member (hub)
5 ... rolling element 24 ... output shaft 29 ... ammeter 45 ... knuckle 51 ... brake caliper 52 ... hydraulic pressure meter (pressing force measuring means)
53A ... Strain sensor (pressing force measuring means)
53B ... Displacement sensor (pressing force measuring means)
55 ... Brake pad 56 ... Brake rotor 60 ... Front / rear direction acting force estimation means 61 ... Abnormality determination means A ... Hub bearing B ... Electric motor C ... Reducer D ... Brake

Claims (11)

The output shaft of the electric motor and the hub of the vehicle wheel are connected coaxially via a speed reducer or directly, provided with a rolling bearing that supports the hub, and provided with a brake that brakes the rotation of the hub. In the wheel bearing device,
Of the three axial forces in the vertical direction, the left-right direction, and the front-rear direction that act on the wheels attached to the hub and the ground contact point of the road surface, the force in the front-rear direction is the current of the electric motor and the before and after only set the direction acting force estimation means, the estimated longitudinal force is in-wheel motor built-in sensor equipped wheel support bearing, characterized in that used for the attitude control of the vehicle to both whether we estimate the braking force of the brake apparatus.   2. The in-wheel motor built-in sensor according to claim 1, further comprising a pressing force measuring means for measuring a pressing force between the brake rotor and the brake pad, and determining a braking force of the brake from the pressing force output from the pressing force measuring means. Wheel bearing device with attached wheels.   3. The in-wheel motor-equipped sensor-equipped bearing device according to claim 2, wherein the pressing force measuring means calculates a pressing force between the brake rotor and a brake pad from a hydraulic pressure of a brake fluid.   3. The in-wheel motor-equipped sensor-equipped bearing device according to claim 2, wherein the pressing force measuring means calculates a pressing force between the brake rotor and a brake pad from deformation of a brake caliper.   The wheel bearing device with an in-wheel type motor built-in sensor according to claim 1, wherein the braking force of the brake is obtained from a detection signal of deformation of the components of the brake.   6. The wheel bearing device with an in-wheel motor-equipped sensor according to claim 5, wherein the brake component that obtains the deformation detection signal is a brake caliper.   The wheel bearing device with a sensor with a built-in in-wheel motor according to claim 1, wherein the braking force of the brake is obtained from a detection signal of deformation of the components of the suspension device.   8. The wheel bearing device with an in-wheel type motor built-in sensor according to claim 7, wherein a component of the suspension device that obtains the deformation detection signal is a knuckle.   2. The wheel bearing device with an in-wheel motor-equipped sensor according to claim 1, wherein a braking force of the brake is obtained from a detection signal of a relative displacement between the brake component and the suspension device component.   10. The wheel bearing device with an in-wheel motor-equipped sensor according to claim 9, wherein the brake component for obtaining the relative displacement is a brake caliper.   The bearing device for a wheel with a sensor with a built-in in-wheel motor according to claim 9, wherein a component of the suspension device for obtaining the relative displacement is a knuckle.

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