JP2009156677A - Rolling bearing device equipped with sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device equipped with a sensor capable of improving linearity of all of five signals output from a signal processing part, reducing operational error generated in operating when subsequently computing physical quantity, and accurately detecting physical quantity to be computed. <P>SOLUTION: This device extracts the output for obtaining axial displacement signal from output terminals YT, YR, YB, and YF different from output terminals T, R, B, and F which extract the output from a displacement detecting part for obtaining radial displacement signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing device with a sensor.

  Conventionally, as a rolling bearing device with a sensor, there is a rolling bearing device for a wheel described in JP 2007-127253 A (Patent Document 1).

In this rolling bearing device for a wheel, an inductance type displacement detection unit is arranged in two rows in the axial direction, and signals from the displacement detection units arranged in the two rows are input to a signal processing circuit. Then, four signals related to radial displacement and one signal related to axial displacement are calculated, and based on these signals, three translational loads and two moment loads of the rolling bearing device for a wheel are calculated. It is supposed to be.
JP 2007-127253 A

  In the conventional apparatus, when each passive element included in the signal processing circuit is set so that the linearity of the signals related to the four radial displacements is improved, the linearity of the signal related to the displacement in one axial direction is poor. On the contrary, if each passive element included in the signal processing circuit is set so that the linearity of the signal related to the displacement in the one axial direction is improved, the linearity of the signal related to the displacement in the four radial directions is deteriorated. .

  That is, it is difficult to improve the linearity of all the five signals. For this reason, it is difficult to reduce calculation errors that occur in subsequent calculations.

  Therefore, an object of the present invention is to improve the linearity of all the five signals output from the signal processing unit, to reduce the calculation error caused by the calculation when the physical quantity is calculated thereafter, and to calculate it. It is an object of the present invention to provide a rolling bearing device with a sensor capable of accurately detecting a physical quantity.

In order to solve the above problems, a rolling bearing device with a sensor according to the present invention comprises:
A first track member having a track surface on the inner peripheral surface;
A second track member having a track surface and an annular displacement detector on the outer peripheral surface;
A rolling element disposed between the raceway surface of the first raceway member and the raceway surface of the second raceway member;
A sensor device for detecting a radial displacement of the displacement detection unit and an axial displacement of the displacement detection unit;
The sensor device is
A first displacement detection unit having a detection surface opposed to the displacement detection unit in the radial direction;
A second displacement detector having a detection surface opposed to the displacement detector in the radial direction;
A third displacement detector having a detection surface positioned in the first displacement detector at an interval in the axial direction and opposed to the displacement detector in the radial direction;
A fourth displacement detection unit positioned on the second displacement detection unit at an interval in the axial direction and having a detection surface opposed to the displacement detection unit in the radial direction;
A first signal processing unit that outputs a first radial displacement signal and a second radial displacement signal based on two radial displacements orthogonal to each other in the displacement detection unit based on a signal from the first displacement detection unit; ,
A second signal processing unit that outputs a third radial displacement signal and a fourth radial displacement signal based on two radial displacements orthogonal to each other in the displacement detection unit based on a signal from the third displacement detection unit; ,
And a third signal processing unit that outputs an axial displacement signal based on an axial displacement of the displacement detection unit based on signals from the second displacement detection unit and the fourth displacement detection unit. Yes.

  According to the present invention, the displacement detection unit and signal processing unit for outputting four radial displacement signals are different from the displacement detection unit and signal processing unit for outputting axial displacement signals. The linearity of all signals of the radial displacement signal and one axial displacement signal can be made excellent. Therefore, it is possible to significantly reduce the calculation error in the subsequent calculation using the four radial displacement signals and the one axial displacement signal. Therefore, the physical quantity to be detected, for example, five loads described in the following embodiments can be detected more accurately.

In one embodiment,
Each of the first displacement detection unit includes the second displacement detection unit, the third displacement detection unit, and the fourth displacement detection unit, each of which includes four portions arranged at approximately equal intervals in the circumferential direction.
When N1 is a natural number and N2 is a natural number smaller than N1,
Each of the portions of the first displacement detection unit includes N1 first coil elements that are directly connected,
The respective portions of the second displacement detection unit include N2 first directly connected elements among the N1 first coil elements directly connected constituting the respective portions of the first displacement detection unit. Consisting of one coil element,
Each of the parts of the third displacement detector comprises N1 second coil elements that are directly connected,
The respective portions of the fourth displacement detection unit include N2 second directly connected elements among the directly connected N1 second coil elements constituting the respective portions of the third displacement detection unit. It consists of two coil elements.

  According to the embodiment, some of the plurality of first coil elements constituting the first displacement detector are also used as the first coil elements constituting the second displacement detector, and the third displacement detector is Since some of the plurality of second coil elements that are configured are also used as the second coil elements that configure the fourth displacement detector, the manufacturing cost of the sensor device can be significantly reduced. Further, the first displacement detector and the second displacement detector can be arranged at the same axial position, and the third displacement detector and the fourth displacement detector can be arranged at the same axial position. The arrangement space of the sensor device can be reduced, and the rolling bearing device with the sensor can be made compact.

In one embodiment,
Each of the first signal processor, the second signal processor, and the third signal processor is
A first node;
A second node;
The respective parts and capacitors connected in parallel between the first node and the second node;
A resistor having one end connected to the first node;
The resistance value of the resistor of the first signal processing unit is the same as the resistance value of the resistor of the second signal processing unit, while the resistance value of the resistor of the first signal processing unit is the third value. It differs from the resistance value of the resistor of the signal processing unit.

  According to the above embodiment, the resistance value of the resistor of the first signal processing unit and the resistance value of the resistor of the third signal processing unit are set appropriately and independently of each other, so that 4 The linearity of one radial displacement signal and one axial displacement signal can be made excellent.

  According to the rolling bearing device with a sensor of the present invention, the displacement detector and signal processor for outputting four radial displacement signals are different from the displacement detector and signal processor for outputting axial displacement signals. Therefore, the linearity of all four radial displacement signals and one axial displacement signal can be made excellent. Accordingly, the calculation error in the subsequent calculation using the four radial displacement signals and the one axial displacement signal can be remarkably reduced, and the physical quantity to be detected such as the load signal can be accurately detected.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view in the axial direction of a rolling bearing device for a vehicle for a driven wheel, which is an embodiment of a rolling bearing device with a sensor according to the present invention.

  The rolling bearing device for a vehicle includes an inner shaft 1, an inner ring 2, an outer ring 3 as a first race member, a plurality of first balls 4 as rolling elements, a plurality of second balls 5 as rolling elements, and a case member. 6 and the sensor device 10.

  The inner shaft 1 has a small diameter shaft portion 19, a medium diameter shaft portion 20, and a large diameter shaft portion 21. A screw is formed on the outer peripheral surface of the small diameter shaft portion 19. The medium-diameter shaft portion 20 is connected to the small-diameter shaft portion 19 via the step portion 18 and has an outer diameter larger than the outer diameter of the small-diameter shaft portion 19. The large-diameter shaft portion 21 is located on the opposite side of the medium-diameter shaft portion 20 from the small-diameter shaft portion 19 side. The large-diameter shaft portion 21 is connected to the medium-diameter shaft portion 20 via a step portion 22 and has an outer diameter larger than the outer diameter of the medium-diameter shaft portion 20. The outer peripheral surface of the large-diameter shaft portion 21 has an angular type raceway groove 23 as a raceway surface, and the outer diameter of the raceway groove 23 increases as the distance from the medium-diameter shaft portion 20 increases.

  The inner shaft 1 has a center hole 31. The center hole 31 is formed in the central portion in the radial direction of the end surface of the inner shaft 1 on the large diameter shaft portion 21 side in the axial direction. The first center hole 31 has a cylindrical portion and extends a predetermined distance in the axial direction. The inner shaft 1 has a rotor mounting flange (or a wheel mounting flange) for mounting a rotor (or a wheel) (not shown) at the end of the large-diameter shaft portion 21 in the axial direction. 50.

  The inner ring 2 is fitted and fixed to the outer peripheral surface of the medium-diameter shaft portion 20 of the inner shaft 1. The end surface of the inner ring 2 on the large diameter shaft portion 21 side in the axial direction is in contact with the stepped portion 22. The inner ring 2 has an angular type raceway groove 28 as a raceway surface on the large-diameter shaft portion 21 side of the outer peripheral surface thereof. The outer diameter of the raceway groove 28 increases as the distance from the large-diameter shaft portion 21 increases. The outer peripheral surface of the inner ring 2 has a cylindrical outer peripheral surface 26 on the side opposite to the large-diameter shaft portion 21 side in the axial direction. The cylindrical outer peripheral surface 26 is different from the large-diameter shaft portion 21 side of the raceway groove 28. The track shoulder 29 located on the opposite side is connected via a step 30. The track shoulder 29 has a cylindrical outer peripheral surface 35. The outer diameter of the cylindrical outer peripheral surface 26 located at the axial end of the outer peripheral surface of the inner ring 2 is smaller than the outer diameter of the cylindrical outer peripheral surface 35 of the track shoulder 29.

  The end surface of the inner ring 2 on the large diameter shaft portion 21 side in the axial direction is in contact with the step portion 22. As shown in FIG. 1, the nut 63 is screwed into the screw of the small diameter shaft portion 19. The end surface of the inner ring 2 opposite to the large-diameter shaft portion 21 in the axial direction is in contact with the end surface of the nut 63 on the large-diameter shaft portion 21 side in the axial direction. The inner ring 2 is securely fixed to the inner shaft 1 by screwing the nut 63 into the large-diameter shaft portion 21 side in the axial direction for a predetermined distance.

  The outer ring 3 is located outward in the radial direction of the large-diameter shaft portion 21. The inner peripheral surface of the outer ring 3 has an angular first raceway groove 44 as a raceway surface and an angular second raceway groove 45 as a raceway surface. The outer ring 3 has a body mounting flange 75 for fixing to the vehicle body. The plurality of first balls 4 are spaced apart from each other in the circumferential direction while being held by the first cage 40 between the raceway groove 28 of the inner ring 2 and the first raceway groove 44 of the outer ring 3. The plurality of second balls 5 are held by the second cage 41 between the raceway groove 23 of the inner shaft 1 and the second raceway groove 45 of the outer ring 3, They are arranged at intervals in the circumferential direction.

  The case member 6 includes a cylindrical member 52 and a disk-shaped lid member 53. An end of the inner peripheral surface of the cylindrical member 52 on the outer ring 3 side is fixed to an end of the outer peripheral surface of the outer ring 3 on the small diameter shaft portion 19 side by a set screw 55. On the other hand, the lid member 53 closes the opening of the cylindrical member 52 on the side opposite to the outer ring side. In this way, foreign matter is prevented from entering the inside of the sensor-equipped rolling bearing device.

  The sensor device 10 includes a first displacement detector 70, a second displacement detector 70, a third displacement detector 71, a fourth displacement detector 71, and a target member 73. The second displacement detector 70 includes a part of the first displacement detector 70, and a part of the first displacement detector 70 is shared by the first displacement detector 70 and the second displacement detector 70. . In FIG. 1, a portion 70 is used as the first displacement detector and the second displacement detector.

  In addition, the fourth displacement detection unit 71 includes a part of the third displacement detection unit 71, and a part of the third displacement detection unit 71 is shared by the third displacement detection unit 71 and the fourth displacement detection unit 71. Has been. In FIG. 1, reference numeral 71 denotes a portion that serves both as the third displacement detector and the fourth displacement detector.

  Accordingly, the first displacement detection unit 70 and the second displacement detection unit 70 have the same position in the axial direction of the place where they are arranged, and the third displacement detection unit 71 and the fourth displacement detection unit 71. Means that the positions in the axial direction of the arranged portions are the same.

  The first to fourth displacement detectors 70 and 71 are fixed to the inner peripheral surface of the cylindrical member 52. On the other hand, the target member 73 has a cylindrical shape. One end of the target member 73 in the axial direction is pressed into the cylindrical outer peripheral surface 26 of the inner ring 2 by press-fitting. One end portion of the target member 73 is externally fitted and fixed to a cylindrical outer peripheral surface 26 as one end portion of the outer peripheral surface of the inner ring 2. The inner shaft 1, the inner ring 2 and the target member 73 constitute a second track member. Moreover, the outer peripheral surface of the target member 73 is a displacement detection part.

  FIG. 2 is an enlarged cross-sectional view of the periphery of the first displacement detector 70 in FIG.

  The third displacement detector 71 is located on the wheel side (the rotor mounting flange 50 side) of the first displacement detector 70. Each of the first and third displacement detectors 70 and 71 is fixed to the inner peripheral surface of the cylindrical member 52. The first displacement detection unit 70 is the same as the third displacement detection unit 71, and the first displacement detection unit 70 is disposed at an interval in the axial direction with respect to the third displacement detection unit 71. The first displacement detector 70 overlaps the third displacement detector 71 substantially in the axial direction.

  FIG. 3 is a circumferential arrangement diagram showing a circumferential configuration of the first displacement detector 70 in a state where the rolling bearing device for a vehicle is installed at a predetermined position of the vehicle.

  The first displacement detector 70 includes four parts. Specifically, the first displacement detector 70 includes a first portion 103, a second portion 104, a third portion 105, and a fourth portion 106, and the first portion 103 is surrounded by a dotted line 101 in FIG. It consists of four first coil elements 103a, 103b, 103c, and 103d existing in the region.

  In FIG. 3, the second portion 104 is composed of the following four first coil elements clockwise from the first coil element 103d, and the third portion 105 is clockwise the next four first coils. The fourth portion 106 is composed of the next four first coil elements in the clockwise direction.

  In FIG. 3, the upper side of the page corresponds to the upper side in the vertical direction when the rolling bearing device for a vehicle is installed at a predetermined position of the vehicle, and the lower side of the page corresponds to the lower side in the vertical direction. The right side corresponds to the rear side of the vehicle on which the rolling bearing device for the vehicle is installed, and the left side of the paper corresponds to the front side of the vehicle.

  As shown in FIG. 3, each first coil element is arranged so that its detection surface (indicated by 222 in FIG. 3) faces inward in the radial direction of the cylindrical member 52. Each first coil element 103 a, 103 b, 103 c, 103 d extends in the radial direction of the cylindrical member 52.

  FIG. 4 is a schematic diagram showing a connection relationship between the four first coil elements 103 a, 103 b, 103 c, and 103 d of the first portion 103.

  As shown in FIG. 4, the four first coil elements 103a, 103b, 103c, and 103d are connected in series. Although not shown in FIG. 4, the first coil element 103a and the first coil element 103b are connected on the radially inner side of the cylindrical member 52 (see FIG. 3), and the first coil element 103b and the first coil element 103b The one coil element 103c is connected on the outer side in the radial direction, and the first coil element 103c and the first coil element 103d are connected on the inner side in the radial direction.

  When a current flows through the four first coil elements 103a, 103b, 103c, and 103d arranged in series, the winding direction of each of the first coil elements 103a, 103b, 103c, and 103d is determined as follows. 103a is the N pole on the radially inner side, the first coil element 103b is the S pole on the radially inner side, the first coil element 103c is the S pole on the radially inner side, and the first coil element 103d is The wiring is wound so that the radially inner side becomes the N pole.

The inductance in each first coil element 103a, 103b, 103c, 103d is L, the area of the radially inner end face (detection surface) of the material on which the coil is wound is A, the magnetic permeability of the material is μ, the coil Is N, and the distance (gap) from the end surface (detection surface) to the target member 73 (see FIG. 2) is d, the following equation (a) is established.
L = A × μ × N ² / d (a)

  Therefore, when the gap d to the target member 73 (see FIG. 2) changes, the inductance L of each first coil element 103a, 103b, 103c, 103d changes, and in each one coil element 103a, 103b, 103c, 103d, The output voltage changes. This rolling bearing device for a wheel detects the fluctuation of the output voltage of the first portion 103 based on the output voltage of each one coil element 103a, 103b, 103c, 103d, from the end face (detection face) to the target part 4. The gap in the radial direction is detected. As described above, since the four first coil elements 103a, 103b, 103c, and 103d are connected in series, the output voltage of the first displacement detector 70 can be increased.

  FIG. 5 shows a detection surface A1 of one first coil element 103a among a plurality of first coil elements constituting the first displacement detection unit 70, and a third displacement overlapping the first coil element 103a in a substantially axial direction. It is a figure which shows the positional relationship with the detection surface A2 of one 2nd coil element 153a among the several 2nd coil elements which comprise the detection part 71. FIG.

  As shown in FIG. 5, the displacement detection portion that is the outer peripheral surface of the target member 73 has a first annular groove 134 and a second annular groove 135. The first annular groove 134 and the second annular groove 135 extend in the circumferential direction. Each of the first annular groove 134 and the second annular groove 135 has a rectangular cross section. The second annular groove 135 is located on the wheel side of the first annular groove 134 with an axial distance from the first annular groove 134.

  Although not shown, in a state where no load is applied to the wheel rolling bearing device, each of the 16 first coil elements 103a, 103b, 103c, 103d,. Each of the 16 first coil elements 103a, 103b, 103c, 103d,..., The 16 second coil elements constituting the third displacement detector 71 that overlaps in the axial direction, the first annular groove 134, and the first The two annular grooves 135 are all in the same positional relationship. Further, the 32 coil elements that constitute the first displacement detection unit 70 and the third displacement detection unit 71 are the same coil elements except for the way of winding the coil.

  As shown in FIG. 5, in the axial direction, the central portion of the detection surface A1 substantially coincides with the edge of the first annular groove 134 on the second annular groove 135 side, while the central portion of the detection surface A2 is The two annular grooves 135 substantially coincide with the edge on the first annular groove 134 side.

  If the target member 73 is displaced from the state in the axial direction toward the lid member 53 by a distance δ, the lap length in the axial direction between the detection surface A1 and the first annular groove 134 (the length overlapping in the axial direction). Decreases, the wrap length in the axial direction between the detection surface A2 and the second annular groove 135 (the overlapping length in the axial direction) increases. From this, the detected displacement value of the gap of the first coil element 103a decreases, while the detected displacement value of the gap of the second coil element 153a increases. Thus, when the target member 73 is displaced in the axial direction, a difference is generated between the displacement detection value detected by the first coil element 103a and the displacement detection value detected by the second coil element 153a.

  When the target member 73 moves in the axial direction, the first annular groove 134 and the second annular portion 135 include each first coil element and each second coil element that substantially overlaps the first coil element in the axial direction. The axial position with respect to the first and second coil elements is set so that the detected displacement detection value is changed in the positive and negative directions. By taking the difference between the displacement detection value of the first coil element and the displacement detection value of the second coil element, the translational amount in the axial direction (the displacement in the axial direction) , Which has a correlation with the translational load).

  Displacement detection values of the portions 103, 104, 105, and 106 of the first displacement detector on the center side (hereinafter referred to as the inner side) of the vehicle, and the wheel side that overlaps the portions 103, 104, 105, and 106 in the axial direction By taking the difference from the displacement detection value of each part of the third displacement detector 71 (hereinafter referred to as the outer side), the displacement detection value with respect to the unit translation amount in the axial direction of the second track member is amplified. Thus, the detection sensitivity of the axial displacement of the sensor device 10 can be increased.

  Contrary to the arrangement shown in FIG. 5, the inner first annular groove is shifted to the outer side with respect to the detection surface of the first displacement detector, and the outer second annular groove is detected as the third displacement. It may be arranged so as to be shifted to the inner side with respect to the detection surface of the part, and in this case as well, the same effect as the above arrangement can be obtained.

  FIG. 6 is a diagram illustrating a gap detection circuit 90 as an example of a part of the first signal processing unit that processes the output of the first displacement detection unit 70. In FIG. 6, in the first displacement detector 70, the first portion 103 and the third portion 105 located in the front-rear direction of the vehicle, and the second portion 104 and the fourth portion 106 located in the vertical direction are simply shown. And simplified. In FIG. 6, arrows A and B indicate correspondence.

  As shown in FIG. 6, in the first displacement detector 70, each of the second portion 104 and the fourth portion 106 positioned in the vertical direction is connected to the oscillator 130. An alternating current having a constant period is supplied from the oscillator 130 to the second portion 104 and the fourth portion 106. Synchronizing capacitors 131 and 139 are connected in parallel to the second portion 104 and the fourth portion 106, respectively.

  As shown in FIG. 6, the first signal processing unit includes a first displacement detection unit connected in parallel between a first node 381, a second node 382, and a first node 381 and a second node 382. The fourth portion 106 and the capacitor 131 have a resistor 120 having one end connected to the first node 381.

  The first signal processing unit includes the first node 383, the second node 384, the second portion 104 of the first displacement detection unit connected in parallel between the first node 383 and the second node 384, and The capacitor 139 and the resistor 121 having one end connected to the first node 383 are included.

  The output voltages (detected values) of the second portion 104 and the fourth portion 106 are input to the differential amplifier 132, and the output voltage (first radial displacement signal) corresponding to the same straight line direction (vertical direction). By doing so, temperature drift is removed. Although not shown, the first portion 103 and the third portion 105 positioned in the front-rear direction also remove the temperature drift by taking the difference with the differential amplifier in the same manner as described above, and output the second radial displacement signal. It is supposed to be.

  The first signal processing unit 90 includes a vertical signal processing circuit shown in FIG. 6 and a front-rear signal processing circuit (not shown) having the same configuration.

  Although not described, the third signal processing unit has the same configuration as the first signal processing unit, and a vertical signal processing circuit and a front-rear signal processing circuit as shown in FIG. It is made up of.

  Referring to FIG. 3 again, the second displacement detector has four parts. Specifically, the second displacement detector includes a first portion 203, a second portion 204, a third portion 205, and a fourth portion 206, and the first portion 203 is surrounded by a dotted line 101 in FIG. It consists of two first coil elements among the four first coil elements 103a, 103b, 103c, 103d existing in the region, specifically, the first coil elements 103a, 103b.

  Further, in FIG. 3, the second portion 204 is composed of the following two first coil elements in the clockwise direction from the first coil element 103d, and the third portion 205 is in the clockwise direction from the second portion 204 to the two second portions. One coil element is skipped and the next two first coil elements are formed, and the fourth part 206 is skipped clockwise from the third part 205 to the two first coil elements, and the next two second coil elements. It consists of one coil element. This relationship is similarly established in the relationship between the second displacement detector and the fourth displacement detector.

  That is, the fourth displacement detection unit also includes four parts, and each part of the fourth displacement detection unit includes two second coil elements among the four second coil elements of each part of the third displacement detection unit. ing. The second displacement detector and the fourth displacement detector are substantially overlapped in the axial direction.

  Referring to FIG. 4, the first portion 203 of the second displacement detection unit includes two first coil elements 103 a and 103 b that are directly connected.

  The output of each part of the second displacement detector and the output of each part of the fourth displacement detector that overlaps each part in the axial direction are the same as the circuit shown in FIG. 6 as the third signal processor. The circuit is differentially amplified.

  Here, the resistance value of the resistor indicated by 120 in FIG. 6 and the resistance value of the resistor indicated by 121 are the signal processing circuit that processes the signals from the first and third displacement detectors, and the second and fourth displacements, respectively. It is set to a different value in the signal processing circuit that processes the signal from the detection unit. The resistance value of the resistor in each signal processing circuit is set to a value with good linearity of a differentially amplified signal that is an output signal in each signal processing circuit.

  FIG. 7 is a diagram showing a calculation method conventionally used in the process of calculating five loads acting on the wheels (described in detail below), and FIG. 8 is a diagram illustrating an apparatus according to the present invention. It is a figure which shows the calculation method used in the process in the middle of calculating five loads which are acting on the wheel.

  As shown in FIG. 7, in the conventional method, the displacement detection unit has only the first and second displacement detection units arranged in two rows in the axial direction, and when calculating the displacement in the radial direction, When calculating the displacement, the calculation is performed using the output of the same displacement detector.

  On the other hand, referring to FIG. 3, in the present invention, in the displacement in the radial direction, the outputs from the first and third displacement detectors composed of four coil elements connected in series (in FIG. 3, R (rear), F (front), T (top), and B (bottom) outputs), while in the axial direction, second and fourth displacements comprising two series-connected coil elements It is calculated from the output from the detector (in FIG. 3, the outputs at YR, YF, YT, and YB) (Note that GND, R, and YR correspond in FIGS. 3 and 4).

  Therefore, in this embodiment, as shown in FIG. 8, the radial signal processing and the axial signal processing can be performed independently of each other. That is, in this embodiment, in order to improve the linearity of the output of the differential signal, the signal processing unit that calculates the radial displacement and the signal processing unit that calculates the axial displacement are shown in FIG. Can be set independently of each other, and the linearity of all signals can be made excellent.

  FIG. 9 is a diagram illustrating an example of a signal output from each signal processing circuit in the apparatus using the conventional arithmetic operation illustrated in FIG. 6, and FIG. 10 is a diagram illustrating a signal output from each signal processing circuit in the apparatus according to the present embodiment. It is a figure which shows an example.

  9 and 10 are compared, the linearity of each signal is remarkably improved in the apparatus of this embodiment compared to the conventional apparatus. Therefore, in the apparatus of this embodiment, the calculation error can be remarkably reduced as compared with the conventional apparatus, and the physical quantities to be detected (in this embodiment, the five loads shown below) can be accurately determined. Can be detected.

  FIG. 11 is a schematic diagram illustrating a method for setting the resistance values of the resistors 120 and 121 shown in FIG. 6 in each signal processing circuit.

  As shown in FIG. 11, when the resistance values of the resistors 120 and 121 shown in FIG. 6 are larger than the appropriate values, the output signal becomes a downwardly convex curve, and conversely, the resistance values of the resistors are smaller than the appropriate values. Then, the output signal becomes a convex curve. By utilizing this phenomenon, the resistance value of the resistor can be set to an appropriate value (a value at which the output becomes a straight line).

  The apparatus of this embodiment has a calculation part connected to each signal processing circuit, and calculates the moment load and translational load of each direction which act on a wheel with this calculation part.

  FIG. 12 is a diagram illustrating the direction.

  As shown in FIG. 12, in this embodiment, the front-rear horizontal direction of the wheel is defined as the x-axis direction, the left-right horizontal direction (axial direction) of the wheel is defined as the y-axis direction, and the vertical direction of the wheel is defined as the z-axis direction.

  Also, the subscript “1” is used for the output signal of each part of the first displacement detection unit on the inner side (vehicle center side), and the output signal of each part of the displacement detection unit on the outer side (wheel side) , Subscript “2” is used. Further, as described above, each part of each displacement detection unit is arranged on the front side, rear side, upper side and lower side of the vehicle, and the displacement detection value of the front side part is defined as “f (front)”. The displacement detection value of the portion is defined as “r (rear)”, the displacement detection value of the upper portion is defined as “t (top)”, and the displacement detection value of the lower portion is defined as “b (bottom)”. It is defined as

Therefore, the output signals of the 16 portions of the first to fourth displacement detectors can be defined as follows.
f1: Displacement detection value of the f disposition portion of the first displacement detection unit r1: Displacement detection value of the r disposition portion of the first displacement detection unit t1: Displacement detection value of the t disposition portion of the first displacement detection unit b1: First displacement Displacement detection value of b arrangement portion of detection unit f2: Displacement detection value of f arrangement portion of third displacement detection unit r2: Displacement detection value of r arrangement portion of third displacement detection unit t2: t arrangement of third displacement detection unit Displacement detection value of part b2: displacement detection value of b arrangement part of the third displacement detection part Yf1: displacement detection value of f arrangement part of the second displacement detection part Yr1: displacement detection value of r arrangement part of the second displacement detection part Yt1: displacement detection value of the t-placement portion of the second displacement detector Yb1: displacement detection value of the b-placement portion of the second displacement detector Yf2: displacement detection value of the f-placement portion of the fourth displacement detector Yr2: fourth displacement Displacement detection value of r arrangement portion of detection unit Yt2: t arrangement of fourth displacement detection unit Displacement detection value of a portion Yb2: displacement detection value of b arrangement portion of the fourth displacement detector

Further, the five differential signals x1, x2, z1, z2 and y1 are defined as follows.
x1 = f1-r1
x2 = f2-r2
z1 = b1-t1
z2 = b2-t2
y1 = Yf2 + Yr2 + Yt2 + Yb2- (Yf1 + Yr1 + Yt1 + Yb1)

ここで、ｍ１１〜ｍ５５は、定数である。 As mentioned above, when each variable is defined,
The five values x1, x2, z1, z2 and y1,
X-direction force acting on the wheel rolling bearing device (Fx), y-direction force acting on the wheel rolling bearing device (Fy), acting on the wheel rolling bearing device The magnitude of the z-direction force (Fz), the moment load around the x-axis acting on the wheel (Mx), and the moment load around the z-axis acting on the wheel There is a linear relationship with (Mz), and the following relationship (1) is established.

Here, m11 to m55 are constants.

Therefore, the following equation (2) is derived from the above (1).

  The said calculating part of the rolling bearing device for wheels of this embodiment has a memory | storage part, and in this memory | storage part, nij of said (2) Formula (each of i and j takes the value of 1-5) 25 elements of a constant matrix of 5 rows and 5 columns shown in the above are input in advance as a look-up table.

  In the wheel rolling bearing device of this embodiment, when each sensor outputs a signal to the signal processing unit, the signal processing unit calculates differential signals x1, x2, z1, z2, and y1 based on those signals. To do. After that, from the calculated x1, x2, z1, z2, and y1 and 25 elements nij of the 5-by-5 constant matrix stored in the storage unit, the calculation of the expression (2) is performed. Thus, Fx, Fy, Fz, Mx and Mz, which are actual forces (loads) acting on the wheel rolling bearing device, are calculated. In other words, in this embodiment, simply referring to the above nij, the vehicle's vertical translation load, the vehicle's translational load, the wheel's axial translational load, the vehicle's vertical translation, simply and cheaply and accurately. The moment load around the direction and the moment load around the traveling direction of the vehicle can be calculated.

  According to the wheel rolling bearing device of the above embodiment, since the signal processing unit that outputs four radial displacement signals and the signal processing unit that outputs an axial displacement signal are different, four radial displacement signals and 1 The linearity of all the signals of one axial displacement signal can be made excellent. Therefore, the calculation error in the subsequent calculation using four radial displacement signals and one axial displacement signal can be greatly reduced, and the detection of five loads (three translational loads and two moment loads) is more accurate. Can be done.

  Moreover, according to the rolling bearing device for wheels of the said embodiment, some 1st coil elements 103a of several 1st coil elements 103a, 103b, 103c, 103d, ... which comprise the 1st displacement detection part 70 are comprised. , 103b,... Are also used as the first coil elements constituting the second displacement detector, and some of the plurality of second coil elements constituting the third displacement detector 71 are replaced by the fourth displacement detector. Since the second coil element is also used, the manufacturing cost of the sensor device 10 can be greatly reduced. The first displacement detector 70 and the second displacement detector 71 can be easily arranged at the same axial position, and the third displacement detector and the fourth displacement detector can be easily arranged at the same axial position. The wheel rolling bearing device can be made compact.

  Further, according to the rolling bearing device for a wheel of the embodiment, the resistance values of the resistors 120 and 121 of the first signal processing unit and the resistance value of the third signal processing unit are appropriately set independently of each other. Therefore, the linearity of all four radial displacement signals and one axial displacement signal can be easily improved.

  In the rolling bearing device for a vehicle according to the above-described embodiment, the displacement detection unit is the outer peripheral surface of the target member 73 that is separate from the inner shaft 1. However, in the present invention, there is no target member and the displacement detection is performed. The part may be a part of the outer peripheral surface of the inner shaft (or inner ring). In the rolling bearing device for a vehicle according to the above embodiment, the inner shaft 1 and the inner ring 2 which are separate from the inner shaft 1 are fitted. However, in the present invention, there is no inner ring and the second track. The member may be composed of a single inner shaft, or may be composed of an inner shaft and a target member, and the inner shaft may have two raceway surfaces on the outer peripheral surface of the inner shaft.

  The sensor device that can be used in the present invention is not limited to the sensor device 10 used in the above-described embodiment, and may be a sensor device partially shown in the following FIGS. 13, 14, and 15.

  Specifically, as in the sensor device 400 shown in FIG. 13, the target member 473 is not formed with the annular grooves 134 and 135, and is larger than the surrounding constituent materials at the positions where the annular grooves 134 and 135 existed ( Alternatively, annular bands 434 and 435 having a small magnetic permeability may be formed. For example, in the case of steel, the annular band portions 434 and 435 can be formed by changing the amount of carbon contained.

  Further, as in the sensor device 500 shown in FIG. 14, the target member 573 is formed with convex portions 541 and 542 whose outer peripheral surfaces are cylindrical surfaces at the positions where the annular grooves 134 and 135 were formed in the above embodiment. You may form the cyclic | annular part 550 in which the outer diameter of a hill part is smaller than the convex parts 541 and 542 in the position where the cyclic | annular part 150 was formed in the said embodiment.

  Further, as in the sensor device 600 shown in FIG. 15, inclined portions 643 and 644 whose inclination directions are opposite to each other in the axial section may be formed on the outer peripheral surface of the target member 673. An annular portion having a groove may be formed in a part of 644. In FIG. 15, both inclined portions 643 and 644 have a valley-shaped joint portion, but the joint portions may be both inclined portions that form a mountain shape.

  Further, the annular groove that can be used in the rolling bearing device with a sensor of the present invention is not limited to the annular groove having a rectangular cross section like the annular grooves 134 and 135 of the above embodiment shown in FIG.

  For example, as shown in the schematic cross-sectional view in the axial direction of the target member 700 shown in FIG. 16, the target member 700 is arranged on the outer peripheral surface of the annular target member 700 at an axial interval, and has an isosceles triangular shape or a cross-sectional regular shape. Two triangular grooves 734 and 735 having a triangular shape can also be used. In FIG. 16, 738 and 739 are virtual lines indicating the positions of the conventional grooves.

  FIG. 17 is a diagram showing a waveform of the Y1 signal when the target member 700 having the annular grooves 734 and 735 having the isosceles triangle cross section shown in FIG. 16 is used.

  According to one experimental example, the present inventor has an isosceles triangular section shown in FIG. 16 as compared to the case where the annular grooves 134 and 135 having a rectangular section shown in FIG. 5 are used as the annular grooves formed in the target member. It was confirmed that the linearity of each output signal can be improved when the annular grooves 734 and 735 are used.

  For this reason, if the annular grooves 734 and 735 shown in FIG. 16 are used as the annular grooves formed in the target member, the physical quantity to be detected can be detected more accurately.

  In addition, in the rolling bearing device with a sensor of the said embodiment, although the displacement detection parts 70 and 71 were fixed to the cylindrical member 52, in this invention, you may attach a displacement detection part directly to an outer ring | wheel.

  In the above embodiment, the sensor-equipped rolling bearing device is a wheel rolling bearing device, but the sensor-equipped rolling bearing device of the present invention is not limited to a wheel rolling bearing device for a driven wheel or a driving wheel. Any bearing device other than a rolling bearing device for a wheel such as a magnetic bearing device may be used. It is needless to say that the configuration of the present invention described in the above embodiment can be applied to various bearing devices having a need to measure a plurality of moment loads and translation loads.

  In the rolling bearing with sensor of the above embodiment, the rolling element of the rolling bearing with sensor is a ball. However, in this invention, the rolling element of the rolling bearing with sensor may be a roller. May contain balls.

  In the rolling bearing device for a wheel according to the above embodiment, the second displacement detector is made up of a part of the first displacement detector, and the fourth displacement detector is made up of a part of the third displacement detector. However, in the present invention, the first displacement detection unit is made up of a part of the second displacement detection unit, and the third displacement detection unit is made up of a part of the fourth displacement detection unit. good. Further, there may be no coil element that is shared by different displacement detection units, and all of the first to fourth displacement detection units may be independent from each other. In the present invention, the first displacement detector and the third displacement detector are arranged to be separated from each other in the axial direction, and the second displacement detector and the fourth displacement detector are arranged to be separated from each other in the axial direction. It is because it is only necessary to be done.

  Further, in the wheel rolling bearing device of the above embodiment, each displacement detection unit is composed of four parts arranged in the rear direction, the front direction, the top direction, and the bottom direction. The part may consist of parts other than four, may consist of parts 1 to 3, or may consist of five or more parts.

It is sectional drawing of the axial direction of the rolling bearing device for vehicles for driven wheels which is one Embodiment of the rolling bearing device with a sensor of this invention. It is an expanded sectional view of the periphery of the 1st displacement detection part in FIG. FIG. 3 is a circumferential arrangement diagram showing a circumferential configuration of a first displacement detector in a state where the rolling bearing device for a vehicle is installed at a predetermined position of the vehicle. It is a schematic diagram which shows the connection relation of four 1st coil elements of the 1st part of a 1st displacement detection part. The detection surface of one first coil element among the plurality of first coil elements constituting the first displacement detector, and the plurality of second elements constituting the third displacement detector overlapping the first coil element substantially in the axial direction. It is a figure which shows the positional relationship with the detection surface of one 2nd coil element of 2 coil elements. It is a figure which shows the gap detection circuit as an example of a part of 1st signal processing part which processes the output of a 1st displacement detection part. It is a figure which shows the calculation method used conventionally in the process in the middle of calculating five loads which are acting on the wheel (it explains in full detail below). It is a figure which shows the calculating method used in the process in the middle of calculating five loads which are acting on the wheel with the apparatus of this invention. FIG. 7 is a diagram illustrating an example of a signal output from each signal processing circuit in the apparatus using the conventional calculation illustrated in FIG. 6. It is a figure which shows an example of the signal which each signal processing circuit output in the apparatus of this embodiment. It is a schematic diagram explaining the setting method of the resistance value of the resistor shown in FIG. 6 in each signal processing circuit. It is a figure explaining a direction. It is a figure which shows a part of sensor apparatus which can be used by this invention. It is a figure which shows a part of sensor apparatus which can be used by this invention. It is a figure which shows a part of sensor apparatus which can be used by this invention. It is a figure which shows a part of sensor apparatus which can be used by this invention. It is a figure which shows an example of the waveform of Y1 signal at the time of using the target member which has an annular groove of an isosceles triangle shape shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner shaft 2 Inner ring 3 Outer ring 4 1st ball 5 2nd ball 70 1st displacement detection part 71 3rd displacement detection part 73 Target member 1st part of a 1st displacement detection part 103
Second portion 104 of the first displacement detector
Third portion 105 of the first displacement detector
Fourth portion 106 of the first displacement detector
First coil element 103a, 103b, 103c, 103d
Second coil element 153a
First portion 203 of the second displacement detector
Second part 204 of the second displacement detector
Third portion 205 of the second displacement detector
Fourth portion 206 of second displacement detector

Claims (3)

A first track member having a track surface on the inner peripheral surface;
A second track member having a track surface and an annular displacement detector on the outer peripheral surface;
A rolling element disposed between the raceway surface of the first raceway member and the raceway surface of the second raceway member;
A sensor device for detecting a radial displacement of the displacement detection unit and an axial displacement of the displacement detection unit;
The sensor device is
A first displacement detection unit having a detection surface opposed to the displacement detection unit in the radial direction;
A second displacement detector having a detection surface opposed to the displacement detector in the radial direction;
A third displacement detector having a detection surface positioned in the first displacement detector at an interval in the axial direction and opposed to the displacement detector in the radial direction;
A fourth displacement detection unit positioned on the second displacement detection unit at an interval in the axial direction and having a detection surface opposed to the displacement detection unit in the radial direction;
A first signal processing unit that outputs a first radial displacement signal and a second radial displacement signal based on two radial displacements orthogonal to each other in the displacement detection unit based on a signal from the first displacement detection unit; ,
A second signal processing unit that outputs a third radial displacement signal and a fourth radial displacement signal based on two radial displacements orthogonal to each other in the displacement detection unit based on a signal from the third displacement detection unit; ,
A third signal processing unit that outputs an axial displacement signal based on an axial displacement of the displacement detection unit based on signals from the second displacement detection unit and the fourth displacement detection unit; Rolling bearing device with sensor. In the rolling bearing device with a sensor according to claim 1,
Each of the first displacement detection unit includes the second displacement detection unit, the third displacement detection unit, and the fourth displacement detection unit, each of which includes four portions arranged at approximately equal intervals in the circumferential direction.
When N1 is a natural number and N2 is a natural number smaller than N1,
Each of the portions of the first displacement detection unit includes N1 first coil elements that are directly connected,
The respective portions of the second displacement detection unit include N2 first directly connected elements among the N1 first coil elements directly connected constituting the respective portions of the first displacement detection unit. Consisting of one coil element,
Each of the parts of the third displacement detector comprises N1 second coil elements that are directly connected,
The respective portions of the fourth displacement detection unit include N2 second directly connected elements among the directly connected N1 second coil elements constituting the respective portions of the third displacement detection unit. A rolling bearing device with a sensor comprising two coil elements. In the rolling bearing device with a sensor according to claim 2,
Each of the first signal processor, the second signal processor, and the third signal processor is
A first node;
A second node;
The respective parts and capacitors connected in parallel between the first node and the second node;
A resistor having one end connected to the first node;
The resistance value of the resistor of the first signal processing unit is the same as the resistance value of the resistor of the second signal processing unit, while the resistance value of the resistor of the first signal processing unit is the third value. A rolling bearing device with a sensor, wherein the resistance value of the resistance of the signal processing unit is different from that of the sensor.

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