JP2008241626A - Wheel support bearing unit with load detection mechanism - Google Patents

Abstract

An object of the present invention is to provide a wheel support bearing unit with a load detection mechanism that has a load detection mechanism that can allow an accuracy error in the mounting position and can be mounted relatively easily even after assembly of the bearing unit.
A bearing unit 10 includes a light emitting element 41 and a light receiving element 42 provided on an end cap 30 fixed to an outer ring member 12, and a reflecting member 43 fixed to the hub 11 so as to rotate together with the hub 11. And a reflection surface 46 that can reflect light emitted from the light emitting element 41 toward the light receiving element 42, and has a load detection mechanism 40 that detects a load load based on the light reception result of the light receiving element 42.
[Selection] Figure 1

Description

  The present invention relates to a wheel support bearing unit with a load detection mechanism that is attached to a suspension device of an automobile and rotatably supports a wheel and can detect a load.

2. Description of the Related Art Conventionally, a technique for detecting a slip ratio of a wheel based on a difference in rotational speed of each wheel and controlling a braking force and a driving force using the signal is used in an automobile. However, since the control with the slip ratio is only a follow-up measure after the occurrence of a slip, research on preventive measures to control the vehicle attitude by detecting the road reaction force has been advanced for the purpose of performing better control. Yes. For this reason, for example, a technique is known in which a magnetostrictive sensor is installed on the outer ring of a wheel support bearing unit, and deformation due to a road surface reaction force on the inner ring side is captured by this magnetostrictive sensor to attempt load detection (for example, Patent Document 1). And 2).
JP 2005-43336 A JP 2005-99003 A

  However, since the deformation of the bearing unit is not so large, the magnetostrictive sensor needs to be accurately processed in the bearing unit where the machining is performed with high accuracy and the deformation is greatly increased. In order to attach the magnetostrictive sensor with high accuracy, it is ideal to attach it alone to the outer ring before assembling the bearing unit. However, if the magnetostrictive sensor is attached in advance, the magnetostrictive sensor will be a significant obstacle to the subsequent assembly work of the bearing unit. As a result, the assembly work becomes difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a load detection mechanism having a load detection mechanism that can tolerate a mounting position accuracy error and can be mounted relatively easily even after the assembly of the bearing unit. Another object is to provide a bearing unit for supporting a wheel.

The above object of the present invention is achieved by the following configurations.
(1) a stationary wheel having a stationary raceway surface on the peripheral surface and connectable to a suspension device;
A rotating wheel having a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface and having a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway surface and the rotation side raceway surface;
The light emitting element and the light receiving element provided on the stationary wheel or a member fixed to the stationary wheel, and the light emitting element provided on the rotating wheel or the member fixed to the rotating wheel so as to rotate together with the rotating wheel. A reflective surface capable of reflecting light emitted from the element toward the light receiving element, and a load detection mechanism for detecting a load load based on a light reception result of the light receiving element;
A wheel support bearing unit with a load detection mechanism.
(2) The load detection mechanism detects the load load by detecting a difference between a shape of light emitted by the light emitting element and a shape of light received by the light receiving element (1). A wheel support bearing unit with a load detection mechanism described in 1.
(3) a stationary wheel having a stationary raceway surface on its peripheral surface and connectable to a suspension device;
A rotating wheel having a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface and having a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway surface and the rotation side raceway surface;
A shadow mask having a plurality of translucent portions provided at predetermined intervals in the rotation direction, provided on the rotation wheel or a member fixed to the rotation wheel so as to rotate together with the rotation wheel, and the shadow mask A light emitting element provided on the stationary ring or a member fixed to the stationary ring on the inner side, and a light emitting element provided on the stationary ring or a member fixed to the stationary ring on the outer side of the shadow mask to emit light of the light emitting element. A light receiving element that receives light through the light transmitting portion, and a load detection mechanism that detects a load load based on a light reception result of the light receiving element;
A wheel support bearing unit with a load detection mechanism.
(4) The load detection mechanism detects the load load by detecting a difference between a shape of the translucent part and a shape of light received by the light receiving element. Wheel support bearing unit with load detection mechanism.

  According to the wheel support bearing unit with a load detection mechanism of the present invention, the load detection mechanism rotates together with the light emitting element and the light receiving element provided on the stationary wheel or a member fixed to the stationary wheel, and the rotating wheel. An optical system that is provided on a rotating wheel or a member fixed to the rotating wheel and has a reflecting surface that can reflect light emitted from the light emitting element toward the light receiving element, and detects a load load based on a light receiving result of the light receiving element By setting the wheel load load state when there is no load or when the vehicle is stationary as the reference position, the load load can be detected even if there is some accuracy error in the mounting position. Easy to install.

  Further, according to the wheel support bearing unit with a load detection mechanism of the present invention, the load detection mechanism is provided on the rotating wheel or a member fixed to the rotating wheel so as to rotate together with the rotating wheel, and is predetermined in the rotation direction. A shadow mask having a plurality of light-transmitting portions formed at intervals, a light emitting element provided on a member fixed to the stationary ring or stationary ring inside the shadow mask, and a stationary ring or stationary ring outside the shadow mask Since it is provided on a fixed member and has a light receiving element that receives light emitted from the light emitting element through a light transmitting portion, and is an optical type that detects a load load based on a light reception result of the light receiving element, Also in this case, by providing the same reference position as described above, the load load can be detected even if there is some accuracy error in the mounting position, and it can be mounted relatively easily after the assembly of the bearing unit.

  Hereinafter, each embodiment of the wheel support bearing unit with a load detection mechanism according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
The wheel support bearing unit 10 with a load detection mechanism of the first embodiment is for a driven wheel. As shown in FIG. 1, a hub 11 that is a rotating wheel and an outer ring member 12 that is a stationary wheel, The ball 13 which is a rolling element is provided. The hub 11 includes a hollow hub wheel 15, and the hub wheel 15 is an end portion on the outboard side (an end portion on the outer side in the vehicle width direction in an assembled state in an automobile) that is a portion of the outer peripheral surface near one end in the axial direction. : The left end of FIG. 1) has a wheel mounting flange 16 extending radially outward. On the wheel mounting flange 16, a plurality of studs 17 for mounting a wheel, a brake rotor, and the like (not shown) constituting the wheel are planted on the outboard side side surface at substantially equal intervals in the circumferential direction.

  A small-diameter step portion 19 is formed at an axial end portion on the inboard side of the hub wheel 15 (the end portion on the inner side in the vehicle width direction in the assembled state in the automobile: the right end portion in FIG. 1). The inner ring 20 constituting the hub 11 is fitted on the outer side. Then, the inner ring 20 is coupled and fixed to the hub wheel 15 by caulking and expanding a portion protruding from the inner end surface of the inner ring 20 of the small-diameter stepped portion 19 in the diametrically outward direction. The inner ring 20 may be fixed to the hub wheel 15 by fastening a nut to the protruding portion of the small diameter step portion 19 of the hub wheel 15. Further, a first inner ring raceway surface 21 which is a rotation side raceway surface is formed on the outer peripheral surface of the hub ring 15 in the axial direction, and a second inner ring raceway surface 22 which is a rotation side raceway surface is formed on the outer peripheral surface of the inner ring 20. Is formed.

  On the inner peripheral surface of the outer ring member 12, a stationary side corresponding to the first outer ring raceway surface 23 corresponding to the first inner ring raceway surface 21 of the hub wheel 15 and the second inner ring raceway surface 22 of the inner ring 20. A second outer ring raceway surface 24 that is a raceway surface is formed. Further, a suspension device mounting flange 25 extending radially outward is provided at an end portion of the outer ring member 12 on the side away from the wheel mounting flange 16, and is fixed to a suspension device (not shown) via the flange 25. ing.

  A plurality of balls 13 are circumferentially arranged between the double-row first and second inner ring raceway surfaces 21 and 22 and the double-row first and second outer ring raceway surfaces 23 and 24 via retainers (not shown). It is arranged so that it can roll. In the illustrated example, the balls 13 are used as the rolling elements. However, in the case of a wheel support bearing unit that is heavy, tapered rollers may be used as the rolling elements.

  Further, a sealing device 27 for sealing an annular space in which a plurality of balls 13 are arranged between the inner peripheral surfaces of both end portions of the outer ring member 12 and the outer peripheral surfaces of the hub wheel 15 and the inner ring 20 facing the inner peripheral surface. , 28 are arranged to prevent leakage of grease filled inside and intrusion of water and foreign matters from the outside.

  On the other hand, the inboard side end of the outer ring member 12 extends axially inward from the seal member 28, and a metal end cap 30 is fitted and fixed to the inner peripheral surface of the inboard side end. ing. The end cap 30 includes a cylindrical portion 31 fitted into the inner peripheral surface of the end portion on the inboard side, and a cover portion 32 that closes the inboard side opening of the outer ring member 12 on one end side of the cylindrical portion 31. .

  An optical load detection mechanism 40 for detecting a load load is provided in the end portion on the inboard side of the outer ring member 12 closed by the end cap 30 and the seal member 28. As shown in FIG. 2, the load detection mechanism 40 is fixed to the inner peripheral surface of the cylindrical portion 31 of the end cap 30 by aligning the positions in the circumferential direction and shifting the position in the axial direction. 41 and a light receiving element 42.

  Further, the load detection mechanism 40 includes a reflection member 43 that is coaxially fixed to the hub wheel 15 inside the end cap 30. The reflecting member 43 is fitted to and fixed to the inner peripheral surface of the cylindrical portion 36 for forming the caulking portion 35 of the hub wheel 15, and is attached to the shaft portion 44. And a mirror portion 45 projecting from the front.

  The outer peripheral surface of the mirror part 45 is formed in a truncated cone shape that becomes gradually narrower toward the inboard side of the vehicle body, and constitutes a reflective surface 46 that is a mirror surface. The reflective surface 46 emits light from the light emitting element 41. Reflected toward the light receiving element 42. Thereby, the light emission of the light emitting element 41 is reflected by the reflecting surface 46 and can reach the light receiving element 42. Note that linear masks 47 may be formed on the reflecting surface 46 at equal intervals in the circumferential direction by photoetching or printing.

  Furthermore, the load detection mechanism 40 includes a load detection calculation unit 48 that detects a load load based on the light reception result of the light receiving element 42. Here, the light receiving element 42 is an imaging element such as a CCD, and is capable of recognizing the reflected light from the reflecting surface 46 of the light emitting element 41, and outputs the signal to the load detection calculation unit 48. The load detection calculation unit 48 detects the load load based on the light receiving position with respect to the reference position of the light received by the light receiving element 42. That is, when the outer ring member 12 and the hub ring 15 are relatively moved or inclined by the load of the bearing unit 10, the arrival position of the reflected light in the light receiving element 42 is moved. Therefore, if the arrival position of the reflected light is detected by the light receiving element 42, the load load of the bearing unit 10 can be determined.

  For example, when a turning outer load shown in the Y1 direction of FIG. 1 is applied to the bearing unit 10 during vehicle turning, the hub wheel 15 is inclined in the Y1 ′ direction of FIG. It moves in the direction A shown in FIG. 2B with respect to the reference position when the vehicle is stopped. By detecting the movement of the light receiving position, the turning outer load is detected. At this time, the reflecting surface 46 also moves in the direction toward the inside of the vehicle body due to the translational force of the hub wheel 15 in the Y1 direction. This is preferable because of the large amount of movement.

  Similarly, when a turning inner load shown in the Y2 direction in FIG. 1 is applied to the bearing unit 10 during vehicle turning, the hub wheel 15 is inclined in the Y2 ′ direction in FIG. Moves in the direction B shown in FIG. 2B with respect to the reference position when the vehicle is stopped. By detecting the movement of the light receiving position, the turning inner load is detected.

  Further, when a load in the longitudinal direction of the vehicle body (X direction) is applied to the bearing unit 10, a relative inclination or displacement in the longitudinal direction occurs, and the light receiving position changes in the C direction or the D direction shown in FIG. . Therefore, the vehicle body longitudinal load is detected by detecting the movement of the light receiving position.

  Moreover, as the light emitting element 41, a laser light emitting element or the like that has good straightness and can easily control the sectional shape of light is preferable. For example, as shown in FIG. 2, when circular light is irradiated, the light received by the light receiving element 42 after being reflected by the reflecting surface 46 becomes elliptical. Since the major axis of the ellipse changes depending on the inclination of the reflecting surface 46, the load on the bearing unit 10 is determined by detecting the difference between the light emission shape of the light emitting element 41 and the light reception shape of the light receiving element 42. You can also If it does in this way, a load can be detected also adding the change of the light reception shape on the basis of the light reception shape after the attachment to the bearing unit 10, and a load load can be detected more accurately.

  Therefore, according to the bearing unit 10 of the first embodiment, the load detection mechanism 40 for detecting the load load includes the light emitting element 41 and the light receiving element 42 provided on the end cap 30 fixed to the outer ring member 12, and the hub. 11 is provided on a reflection member 43 fixed to the hub 11 so as to rotate together with the light source 11, and has a reflection surface 46 capable of reflecting light emitted from the light emitting element 41 toward the light receiving element 42. Since the optical type detects the load based on the result, the load can be detected even if there is some accuracy error in the mounting position, and can be mounted relatively easily after the bearing unit 10 is assembled. Since the load detection mechanism 40 can be attached relatively easily as described above, it is possible to implement a preventive measure for controlling the vehicle posture by detecting the road surface reaction force, and to improve the driving stability and safety of the vehicle. it can.

  The load detection mechanism 40 detects the load load by detecting the difference between the shape of the light emitted from the light emitting element 41 and the shape of the light received by the light receiving element 42 in addition to the change in the light receiving position. Therefore, the load can be detected based on the change in the light receiving shape based on the light receiving position and shape after being attached to the bearing unit 10, and the load load can be detected with higher accuracy.

  Further, if the masks 47 are formed on the reflecting surface 46 at equal intervals in the circumferential direction, the light received by the light receiving element 42 during the rotation of the hub wheel 15 becomes intermittent according to the rotation of the hub 11, and therefore very much. An accurate rotation speed signal can be obtained with a fine pitch.

  Note that the light emitting element 41 and the light receiving element 42 may be arranged at an angle in the circumferential direction as shown in FIG. 3 instead of arranging them in the circumferential direction as described above. .

  Further, instead of providing the light emitting element 41 and the light receiving element 42 on the cylindrical portion 31 of the end cap 30, the light emitting element 41 and the light receiving element 42 may be provided on the outer ring member 12, and either the light emitting element 41 or the light receiving element 42 may be provided. One may be provided on the end cap 30, and the other may be provided on the outer ring member 12.

  The load detection mechanism 40 is partitioned by a seal member 27 outside the vehicle body and a seal member 28 inside the vehicle body instead of being arranged between the seal member 28 inside the vehicle body and the cover portion 32 of the end cap 30. It can also be provided in the inter-column space 37.

  Furthermore, a plurality of load detection mechanisms 40 can be provided for one bearing unit 10, for example, in the vehicle longitudinal direction (X direction) and the vertical direction (Z direction), respectively, so that load detection accuracy can be further improved.

  Further, the reflecting surface may be a cylindrical shape instead of the truncated cone shape as in the present embodiment, and further, a load is applied from the locus of the light receiving position using a polygon mirror having a polygonal reflecting surface. Although it may be detected, a high-precision polygon mirror having a large number of corners is expensive, and is preferably a truncated cone shape or a cylindrical shape.

(Second Embodiment)
Next, a wheel support bearing unit with a load detection mechanism according to a second embodiment of the present invention will be described with reference to FIG. In addition, this embodiment differs from 1st Embodiment in the structure of a load detection mechanism, About the part equivalent to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  The load detection mechanism 50 of the second embodiment has a shadow mask 51 that is coaxially fixed to the hub wheel 15 inside the end cap 30. The shadow mask 51 includes a shaft portion 52 that is fitted and fixed to the cylindrical portion 36 for forming the crimped portion 35 of the hub wheel 15, a disk portion 53 that extends in the radial direction from one end of the shaft portion 52, and a circle A cylindrical portion 54 that extends from the outer peripheral edge of the plate portion 53 to the opposite side of the shaft portion 52 is provided. In the cylindrical portion 54 of the shadow mask 51, a plurality of translucent portions 55 made of holes penetrating in the radial direction are formed at equal intervals in the circumferential direction with the axial position aligned. The portion is masked so as not to transmit light in the radial direction.

  In the load detection mechanism 50, a light emitting element 57 that is a point light source is fixed at the center position of the cover portion 32 of the end cap 30 so as to advance to the center position in the cylindrical portion 54 of the shadow mask 51. Further, the load detection mechanism 50 includes a light receiving element 58 that is fixed to the inner peripheral surface of the cylindrical portion 31 of the end cap 30 outside the shadow mask 51 in the radial direction.

  The load detection mechanism 50 includes a load detection calculation unit 59 that detects a load load based on the light reception result of the light receiving element 58. Here, the light receiving element 58 is an image pickup element such as a CCD, and is capable of pattern recognition of the light receiving shape, and outputs a signal thereof to the load detection calculation unit 59. The load detection calculation unit 59 detects the load load by detecting the light receiving position of the light received by the light receiving element 58 with respect to the reference position. In other words, the light emitted from the light emitting element 57 passes through the light transmitting portion 55 and reaches the light receiving element 58. The light reaching position in the light receiving element 58 depends on the load of the bearing unit 10. If the outer ring member 12 and the hub ring 15 are relatively moved or inclined, they are moved. Therefore, if the light arrival position is detected by the light receiving element 58, the load applied to the bearing unit 10 can be determined as in the first embodiment.

  Therefore, according to the bearing unit 10 of the second embodiment, the load detection mechanism 50 for detecting the load is provided on the hub 11 so as to rotate together with the hub 11 and is formed at a predetermined interval in the rotation direction. The shadow mask 51 having a plurality of light transmitting portions 55, the light emitting element 57 provided on the end cap 30 fixed to the outer ring member 12 inside the shadow mask 51, and the end cap 30 provided outside the shadow mask 51. In this case, the optical element includes a light receiving element 58 that receives light emitted from the light emitting element 57 via the light transmitting portion 55, and detects a load load based on a light reception result of the light receiving element 58. However, even if there is some accuracy error in the mounting position, it is possible to detect the load and relatively easily mount it after the bearing unit is assembled. Since the load detection mechanism 50 can be attached relatively easily as described above, it is possible to implement a preventive measure for controlling the vehicle posture by detecting the road surface reaction force, thereby improving the handling stability and safety of the vehicle. it can.

Further, the shadow mask 51 is tilted due to the load applied to the bearing unit 10, and the difference between the shape of the light transmitting portion 55 and the shape of the light received by the light receiving element 58 also changes, so that the light receiving shape after being attached to the bearing unit 10. The load applied to the bearing unit 10 can also be determined by the change in the light receiving shape of the light receiving element 58 with reference to.
Furthermore, the load on the bearing unit 10 can be determined from the locus of the light receiving position.

  Further, as described above, since the translucent portions 55 are formed in the shadow mask 51 at equal intervals in the circumferential direction, the light received by the light receiving element 58 when the hub wheel 15 rotates depends on the rotation of the hub wheel 15. Therefore, an accurate rotation speed signal can be obtained with a very fine pitch. Here, it is also possible to detect the absolute position in the rotation direction of the hub wheel 15 by making the shape of the translucent part 55 different depending on the position.

  Furthermore, also in the present embodiment, a plurality of load detection mechanisms 50 are provided for one bearing unit 10, for example, in the vehicle body longitudinal direction (X direction) and the vertical direction (Z direction), respectively, to further increase load detection accuracy. You can also.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In the above embodiment, the load detection mechanism 40 is attached to the cylindrical portion 36 for forming the crimping portion 35, but it may be at any position of the hub wheel 15 or may be provided on the inner ring 20. . When the inner ring 20 is fixed with a nut, the load detection mechanism 40 may be provided on any of the hub wheel 15, the inner ring 20, and the nut.
In the above embodiment, the bearing unit for the driven wheel has been described. However, the present invention can also be applied to a bearing unit for the driving wheel.

It is sectional drawing which shows the bearing unit of 1st Embodiment of this invention. (A) is a principal part enlarged view for demonstrating the load detection by a load detection mechanism, (b) is a figure which shows the light-receiving state of a light receiving element. FIG. 3 is a view taken along the arrow III in FIG. It is a fragmentary sectional view showing the bearing unit of a 2nd embodiment of the present invention.

Explanation of symbols

10 Wheel support bearing unit with load detection mechanism 11 Hub (rotating wheel)
12 Outer ring member (stationary ring)
13 balls (rolling elements)
15 Hub wheel 20 Inner ring 21 First inner ring raceway surface (rotation side raceway surface)
22 Second inner ring raceway surface (rotation side raceway surface)
23 First outer ring raceway surface (stationary raceway surface)
24 Second outer ring raceway surface (stationary raceway surface)
40, 50 Load detection mechanism 41, 57 Light emitting element 42, 58 Light receiving element 46 Reflecting surface 51 Shadow mask 55 Translucent part

Claims (4)

A stationary wheel having a stationary raceway surface on the peripheral surface and connectable to a suspension device;
A rotating wheel having a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface and having a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway surface and the rotation side raceway surface;
The light emitting element and the light receiving element provided on the stationary wheel or a member fixed to the stationary wheel, and the light emitting element provided on the rotating wheel or the member fixed to the rotating wheel so as to rotate together with the rotating wheel. A reflective surface capable of reflecting light emitted from the element toward the light receiving element, and a load detection mechanism for detecting a load load based on a light reception result of the light receiving element;
A wheel support bearing unit with a load detection mechanism.   The load detection mechanism detects the load load by detecting a difference between a shape of light emitted from the light emitting element and a shape of light received by the light receiving element. Wheel support bearing unit with load detection mechanism. A stationary wheel having a stationary raceway surface on the peripheral surface and connectable to a suspension device;
A rotating wheel having a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface and having a wheel mounting flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements provided between the stationary side raceway surface and the rotation side raceway surface;
A shadow mask having a plurality of translucent portions provided at predetermined intervals in the rotation direction, provided on the rotation wheel or a member fixed to the rotation wheel so as to rotate together with the rotation wheel, and the shadow mask A light emitting element provided on the stationary ring or a member fixed to the stationary ring on the inner side, and a light emitting element provided on the stationary ring or a member fixed to the stationary ring on the outer side of the shadow mask to emit light of the light emitting element. A light receiving element that receives light through the light transmitting portion, and a load detection mechanism that detects a load load based on a light reception result of the light receiving element;
A wheel support bearing unit with a load detection mechanism.   The load detection mechanism according to claim 3, wherein the load detection mechanism detects the load load by detecting a difference between a shape of the light transmitting portion and a shape of light received by the light receiving element. Bearing unit for wheel support.

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