JP4862318B2 - Load measuring device - Google Patents

Description

  The load measuring device according to the present invention is incorporated in a wheel bearing rolling bearing unit that supports a vehicle (automobile) wheel rotatably with respect to a suspension device, measures the load applied to the wheel, and operates the vehicle stably. Use to secure.

  For example, a rolling bearing unit is used to rotatably support a vehicle wheel with respect to a suspension device. In order to ensure the running stability of the vehicle, a running state stabilizing device for the vehicle such as an antilock brake system (ABS) or a traction control system (TCS) is widely used. According to these running state stabilizing devices such as ABS and TCS, the running state of the vehicle at the time of braking or acceleration can be stabilized, but in order to ensure this stability even under more severe conditions, the vehicle It is necessary to control the brakes and the engine by incorporating more information that affects the running stability of the vehicle.

  That is, in the case of the conventional running state stabilizing device such as ABS or TCS, since so-called feedback control is performed to detect the slip between the tire and the road surface and control the brake and the engine, the brake and engine Control is delayed for a moment. In other words, in order to improve performance under severe conditions, the so-called feed-forward control prevents slippage between the tire and the road surface, or the so-called brake one-side effect where the braking forces of the left and right wheels are extremely different. Cannot be prevented.

  In order to cope with such a problem, in order to perform the feedforward control or the like, one of a radial load and an axial load applied to the wheel is applied to the rolling bearing unit for supporting the wheel with respect to the suspension device. Or it is possible to incorporate a load measuring device for measuring both. Conventionally, what was described in patent documents 1-5 is known as a wheel bearing rolling bearing unit with a load measuring device which can be used in such a case.

  Of these, Patent Document 1 describes a rolling bearing unit with a load measuring device capable of measuring a radial load. In the case of the first example of this conventional structure, by measuring the displacement in the radial direction between the outer ring that does not rotate and the hub that rotates on the inner diameter side of the outer ring by a non-contact type displacement sensor, The radial load applied to the hub is calculated. The obtained radial load is used not only to properly control the ABS but also to inform the driver of a bad loading condition.

  Patent document 2 describes a structure for measuring an axial load applied to a rolling bearing unit. In the case of the second example of the conventional structure described in Patent Document 2, bolts for connecting the fixed side flange to the knuckle are screwed at a plurality of positions on the inner side surface of the fixed side flange provided on the outer peripheral surface of the outer ring. Each load sensor is attached to a portion surrounding the screw hole. Each load sensor is clamped between the outer surface of the knuckle and the inner surface of the fixed flange in a state where the outer ring is supported and fixed to the knuckle. In the case of the load measuring device for the rolling bearing unit of the second example having such a conventional structure, the axial load applied between the wheel and the knuckle is measured by the load sensors.

  Further, in Patent Document 3, the displacement sensor unit supported at four positions in the circumferential direction of the outer ring and the L-shaped detection ring that is externally fitted and fixed to the hub are used to detect the above-described outer ring at the four positions. A structure is described in which the displacement of the hub in the radial direction and the axial direction is detected, and the direction of the load applied to the hub and the magnitude thereof are determined based on the detection values of the respective parts.

  Further, in Patent Document 4, a strain gauge for detecting dynamic strain is provided in a member corresponding to an outer ring whose rigidity is partially reduced, and the revolution speed of the rolling element is determined from the passing frequency of the rolling element detected by the strain gauge. A method for determining the axial load applied to the rolling bearing from the revolution speed is described.

  Further, in Patent Document 5, the revolution speed of the rolling elements provided with contact angles in opposite directions is changed depending on the direction and magnitude of the load, and the outer ring that is a stationary side race ring is rotated. The structure which calculates | requires one or both of the radial load and axial load which act between the hubs which are a side track ring is described.

  Although not disclosed, for example, in Japanese Patent Application No. 2005-147642, the displacement between these two races is measured by an encoder supported on the rotation side raceway and a sensor supported on the stationary side raceway. The structure which calculates | requires the load added between these both bearing rings from this displacement is disclosed. 5 to 7 show a first example of the prior invention disclosed in Japanese Patent Application No. 2005-147642. As shown in FIG. 5, the structure of the first example of the prior invention is a rotating side track that supports and fixes a wheel radially inward of the outer ring 1 that is a stationary side ring that does not rotate while being supported by a suspension device. A hub 2 that is a ring is rotatably supported via a plurality of rolling elements 3 and 3. Then, an encoder 4 configured in a cylindrical shape by a permanent magnet is externally fitted and fixed to an intermediate portion of the hub 2, and each of the rolling elements 3 and 3 disposed in a double row at an axially intermediate portion of the outer ring 1. The sensor 5 is provided in the intermediate portion in a state where the detection portion is close to and opposed to the outer peripheral surface of the encoder 4 that is the detection surface. In addition, it is appropriate to incorporate a magnetic detection element such as a Hall IC, a Hall element, an MR element, or a GMR element in the detection portion of the sensor 5.

  As shown in FIG. 6, the outer peripheral surface of the encoder 4 includes a portion magnetized in the N pole (first characteristic portion) and a portion magnetized in the S pole (second characteristic portion) in the circumferential direction. They are arranged alternately and at equal intervals. A linear shape in which the shape of the boundary between the part magnetized in the N pole and the part magnetized in the S pole is inclined by a predetermined angle with respect to the axial direction of the encoder 4 (the width direction of the outer peripheral surface). In addition, the inclination directions with respect to the axial direction are opposite to each other at the boundaries adjacent to each other in the circumferential direction. As a result, the width in the circumferential direction of the portion magnetized in the N pole is made wider toward one axial side {lower side in FIG. 6B), and the circumference of the portion magnetized in the S pole The width with respect to the direction is made wider toward the other side in the axial direction (upper side in FIG. 6B). In the illustrated structure, since the encoder 4 is made of a permanent magnet, no permanent magnet is incorporated on the sensor 5 side. On the other hand, when using an encoder made of a magnetic material (for example, the first characteristic part is a convex part or a column part and the second characteristic part is a concave part or a through hole), the sensor 5 side is used. Incorporate a permanent magnet.

In the case of the first example of the prior invention configured as described above, the ratio relating to the output signal of the sensor 5 changes when an axial load acts between the outer ring 1 and the hub 2. This point will be described with reference to FIG. First, in a state where an axial load is not applied between the outer ring 1 and the hub 2, the detection portion of the sensor 5 is on the chain line α in FIG. 7, that is, in the axial center of the outer peripheral surface of the encoder 4. Suppose that they face each other. On this chain line α, the width in the circumferential direction of the part magnetized in the N pole and the width in the circumferential direction of the part magnetized in the S pole are equal to each other. As shown in FIG. 7B, the same voltage is swung on both sides around the reference voltage (for example, 0 V). That is, the period T _H when the voltage of the output signal is higher than the reference voltage and the period T _{L when} it is lower are equal to each other (T _H = T _L ). The difference ΔV _H between the maximum value of the output signal voltage and the reference voltage and the difference ΔV _L between the minimum value and the reference voltage are also equal to each other (ΔV _H = ΔV _L ).

On the other hand, when a downward axial load in FIG. 7 acts on the hub 2 to which the encoder 4 is fixed (the outer ring 1 and the hub 2 are relatively displaced in the axial direction), the sensor 5 The detection unit faces the portion on the chain line β in FIG. On the chain line β, the width in the circumferential direction of the portion magnetized in the N pole is narrower than the width in the circumferential direction of the portion magnetized in the S pole. As shown in (A) of FIG. 7, the reference voltage (for example, 0 V) is largely shifted toward the lower side. That is, the period T _{L at} which the voltage of the output signal is lower than the reference voltage is greater than the period T _{H at} which the voltage T _L becomes higher (T _H <T _L ). Further, the difference ΔV _L between the minimum value of the output signal voltage and the reference voltage is also larger than the difference ΔV _H between the maximum value and the reference voltage (ΔV _L > ΔV _H ).

Further, when an upward axial load in FIG. 7 is applied to the hub 2 to which the encoder 4 is fixed, the detection portion of the sensor 5 faces the portion on the chain line γ in FIG. On this chain line γ, the width in the circumferential direction of the portion magnetized in the N pole is wider than the width in the circumferential direction of the portion magnetized in the S pole. As shown in (C) of FIG. 7, the reference voltage (for example, 0V) is largely swung to the higher side. That is, the period T _H when the voltage of the output signal becomes higher than the reference voltage is larger than the period T _{L when} it becomes lower (T _H > T _L ). Further, the difference ΔV _H between the maximum value of the output signal voltage and the reference voltage is also larger than the difference ΔV _L between the minimum value and the reference voltage (ΔV _H > ΔV _L ).

Therefore, the axial displacement of the hub 2 relative to the outer ring 1 can be obtained by looking at the ratio of the output signal of the sensor 5. Specifically, by looking at the ratio "T _{H /} T _L" in the period T _L of the potential of the output signal becomes lower as the higher becomes the period T _H than the reference voltage, it finding the axial displacement it can. Or, observe the ratio “ΔV _H / ΔV _L ” between the difference ΔV _H between the maximum value of the voltage of the output signal and the reference voltage and the difference ΔV _L between the minimum value and the reference voltage. Can also determine the amount of axial displacement. Furthermore, the output signal of the sensor 5 is converted into a rectangular wave signal in which, for example, the higher side than the reference voltage is set to a high level and the lower side is set to a low level, and the duty ratio “T _H / ( The axial displacement amount can also be obtained by observing “T _H + T _L )”. Each of these ratios _"T H / _{T L",} "△ _{V H} / △ _{V L",} the relationship between _{"T H / (T H + T} L) " and the axial displacement is also concerning in any ratio Since it is linear, it is easily obtained. Then, the obtained relationship is incorporated in software installed in a computing unit (microcomputer) (not shown).

Further, the relationship between the axial displacement and the axial load can be obtained by calculation or experiment. When obtaining by calculation, it is obtained based on the theory widely known in the technical field of the rolling bearing unit based on the specifications and materials of the rolling bearing unit. Further, when obtained by experiment, the axial displacement of the hub 2 with respect to the outer ring 1 is measured while applying different known axial loads between the outer ring 1 and the hub 2. To do. In any case, the relationship between the axial displacement amount and the axial load is obtained and incorporated in the software. At the time of operation, the arithmetic unit operates as any one of the ratios “T _H / T _L ”, “ΔV _H / ΔV _L ”, “T _H / (T _H + T _L )” regarding the output signal of the sensor 5. The axial load is determined based on the above relationships.

  Next, FIGS. 8 to 11 show a second example of the prior invention disclosed in Japanese Patent Application No. 2005-147642. In the case of the second example of the present invention, an encoder 4a configured in a cylindrical shape by a permanent magnet is fitted and fixed to an intermediate portion of the hub 2 which is a rotating side raceway, and the outer ring 1 which is a stationary side raceway is fixed. A pair of sensors 5, 5 are arranged between the rolling elements 3, 3 arranged in a double row at the axially intermediate portion, and the respective detection portions are made to face each other close to the outer peripheral surface of the encoder 4 a as a detection surface. Provided.

  As shown in FIGS. 9 to 11, on the outer peripheral surface of the encoder 4a, there are a portion magnetized in the N pole (first characteristic portion) and a portion magnetized in the S pole (second characteristic portion). They are alternately arranged at equal intervals in the direction. Further, the outer peripheral surface is divided into two regions adjacent to each other in the axial direction with the central portion of the encoder 4a in the axial direction (the width direction of the outer peripheral surface) as a boundary, and these regions are attached to the N pole. The form of the boundary between the magnetized portion and the portion magnetized to the S pole is made different from each other. Specifically, in each of the above regions, the shape of the boundary between the portion magnetized at the N pole and the portion magnetized at the S pole is a linear shape inclined by the same angle as an absolute value with respect to the axial direction. In addition, the inclination directions of the boundary with respect to the axial direction are opposite to each other in the regions. Therefore, the axially central portion of the portion magnetized by the N pole and the portion magnetized by the S pole arranged on the outer peripheral surface protrudes most (or is depressed) in the circumferential direction. , "K" character shape.

  Each of the sensors 5 and 5 incorporates a magnetic detection element such as a Hall IC, a Hall element, MR, or GMR in the detection unit. The positions at which the detection parts of both the sensors 5 and 5 face the outer peripheral surface of the encoder 4a are the same with respect to the circumferential direction of the encoder 4a. In other words, the detection parts of the sensors 5 and 5 are arranged on the same virtual plane including the central axis of the outer ring 1. Further, in a state where an axial load is not applied between the outer ring 1 and the hub 2, a circumferential direction is provided at the axial center portion between the portion magnetized at the N pole and the portion magnetized at the S pole. The positions where the members 4a, 5 and 5 are installed so that the most protruding part (the part where the inclination direction of the boundary changes) exists at the central position between the detection parts of the sensors 5 and 5 above. It is regulated.

  In the case of the second example of the prior invention configured as described above, when an axial load is applied between the outer ring 1 and the hub 2, the phase in which the output signals of the sensors 5, 5 change is shifted. That is, in a state where an axial load is not applied between the outer ring 1 and the hub 2, the detection parts of the sensors 5 and 5 are on the solid lines A and B in FIG. It faces a portion that is shifted by the same amount in the axial direction from the most protruding portion. Accordingly, the phases of the output signals of the sensors 5 and 5 coincide as shown in FIG. On the other hand, when a downward axial load acts on the hub 2 to which the encoder 4a is fixed in FIG. 11A (the outer ring 1 and the hub 2 are relatively displaced in the axial direction), The detection parts of the sensors 5 and 5 are opposed to the broken lines B and B in FIG. 11A, that is, the parts different from each other in the axial direction from the most protruding part. In this state, the phases of the output signals of the sensors 5 and 5 are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 2 to which the encoder 4a is fixed as shown in FIG. 11A, the detecting portions of both the sensors 5 and 5 are connected to the chain line hub of FIG. , C, that is, the deviation in the axial direction from the most projecting portion opposes different portions in the opposite direction. In this state, the phases of the output signals of the sensors 5 and 5 are shifted as shown in FIG.

  Thus, in the case of the second example of the prior invention, the phases of the output signals of the sensors 5 and 5 are shifted in a direction corresponding to the direction of the axial load applied between the outer ring 1 and the hub 2. . Further, the degree to which the phase of the output signals of the sensors 5, 5 is shifted by this axial load (displacement amount) increases as the axial load increases. Therefore, in the case of the above-described second example of the present invention, the outer ring 1 and the outer ring 1 are determined based on the presence / absence of the phase shift of the output signals of the sensors 5 and 5 and, if there is a shift, the direction and magnitude. The direction and magnitude of the axial relative displacement with the hub 2 and, in turn, the direction and magnitude of the axial load acting between the outer ring 1 and the hub 2 can be obtained. In the case of the second example of the prior invention, as in the case of the first example of the previous invention, the calculation for obtaining the axial relative displacement amount and the axial load is performed by a calculator (not shown).

  Next, FIG. 12 shows a third example of the prior invention, which has been undisclosed, but which the present inventor previously considered. In the case of the third example of the present invention, an encoder 4b configured in a cylindrical shape by a permanent magnet is fitted and fixed to the intermediate portion of the hub 2 which is a rotating side raceway through a support ring 12 having a crank-shaped cross section. ing. On the outer peripheral surface, which is the detected surface of the encoder 4b, portions magnetized in the N pole (first characteristic portion) and portions magnetized in the S pole (second characteristic portion) are alternately arranged in the circumferential direction. And it arranges at equal intervals. As shown in FIG. 12A, the shape of the boundary between the portion magnetized at the N pole and the portion magnetized at the S pole is defined as the axial direction of the encoder 4b (the width direction of the outer peripheral surface). ) In the same direction and inclined by the same angle. On the outer peripheral surface of such an encoder 4b, the detection unit 6 of the sensor 5 supported on the intermediate portion in the axial direction of the outer ring 1 which is a stationary-side raceway is closely opposed in the radial direction. In addition, it is appropriate to incorporate a magnetic detection element such as a Hall IC, a Hall element, an MR element, or a GMR element into the detection unit 6 of the sensor 5.

  Further, the inner end portion of the outer ring 1 {"inner with respect to the axial direction" means the center side in the width direction of the vehicle when assembled to an automobile, and the inner peripheral surface of the right side in FIG. 12 (A) and FIG. An annular second encoder 9 is formed on the inner surface of the slinger 8 that is externally fitted and fixed to the inner end portion of the hub 2 that constitutes the combined seal ring 7 that closes the outer peripheral surface of the inner end portion of the hub 2. It is attached and fixed concentrically with the hub 2. On the inner side surface, which is the detected surface of the second encoder 9, portions magnetized in the N pole and portions magnetized in the S pole are arranged alternately and at equal intervals in the circumferential direction. Further, as shown in FIG. 12B, the boundary between the portion magnetized at the N pole and the portion magnetized at the S pole is a linear shape in the radial direction. The number of S poles and N poles existing on the outer peripheral surface of the encoder 4b is equal to the number of S poles and N poles existing on the inner side surface of the second encoder 9. On the inner side surface of the second encoder 9, the detection unit 11 of the second sensor 10 supported by a part of a stationary member such as a knuckle (not shown) constituting the suspension device is made to face and oppose in the axial direction. ing. In addition, it is appropriate to incorporate a magnetic detection element such as a Hall IC, a Hall element, an MR element, or a GMR element into the detection unit 11 of the second sensor 10.

  In the case of the third example of the present invention, an axial load does not act between the outer ring 1 and the hub 2, and the outer ring 1 and the hub 2 are not displaced relative to each other in the axial direction. Thus, the detection signals of the sensors 4b and 9 are changed simultaneously (or with a predetermined time difference). For this reason, in the neutral state, the detection unit 11 of the second sensor 10 faces the boundary between the S pole and the N pole existing on the inner surface of the second encoder 9 and at the same time, the detection of the sensor 5 The installation positions of the members 10, 9, 5, 4b are restricted so that the portion 6 faces the boundary between the S pole and the N pole existing on the outer peripheral surface of the encoder 4b.

  In the third example of the prior invention configured as described above, when an axial load acts between the outer ring 1 and the hub 2 (the outer ring 1 and the hub 2 are relatively displaced in the axial direction), The phases of the output signals of both sensors 5, 10 are shifted. That is, the phase of the detection signal of the second sensor 10 facing the inner surface of the second encoder 9 is constant (no advance or delay) regardless of the presence or absence of the relative displacement. On the other hand, the phase of the detection signal of the sensor 5 facing the outer peripheral surface of the encoder 4b is advanced or delayed with the relative displacement. Therefore, the phases of the output signals of the sensors 5 and 10 are shifted by the amount of advance or delay.

  Thus, in the case of the third example of the present invention, the phases of the output signals of the sensors 5, 10 are shifted in a direction corresponding to the direction of the axial load applied between the outer ring 1 and the hub 2. . Further, the degree to which the phase of the output signals of the sensors 5 and 10 is displaced by this axial load (the amount of displacement) increases as the axial load increases. Therefore, in the case of the above-described third example of the present invention, the outer ring 1 and the outer ring 1 are determined based on the presence / absence of a phase shift between the output signals of the sensors 5 and 10 and, if there is a shift, the direction and magnitude thereof. The direction and magnitude of the axial relative displacement with the hub 2 and, in turn, the direction and magnitude of the axial load acting between the outer ring 1 and the hub 2 can be obtained. In the case of the third example of the prior invention, as in the case of the first example of the previous invention described above, the calculation for obtaining the axial relative displacement amount and the axial load is performed by a calculator (not shown).

  Next, FIG. 13 shows a fourth example of the prior invention, which is still unpublished, and which the present inventor considered earlier. In the case of the fourth example of the prior invention, the support ring 13 is fitted and fixed concentrically with the hub 2 at the inner end of the hub 2 which is the rotating raceway. At the same time, a cylindrical encoder 4b having the same configuration as that used in the above-described third example of the invention is attached and fixed to the outer peripheral surface of the large-diameter cylindrical portion 14 constituting the support ring 13. Further, the detection portions of the pair of sensors 5a and 5b are made to face each other close to the upper and lower end portions of the outer peripheral surface which is the detection surface of the encoder 4b. That is, both the sensors 5a and 5b are supported and fixed at both upper and lower ends of the inner peripheral surface of the cover 15 attached to the inner end opening of the outer ring 1 which is a stationary side race, and the detection of these sensors 5a and 5b is performed. The portion is made to face and oppose the upper and lower end portions of the outer peripheral surface of the encoder 4b. In addition, it is appropriate to incorporate a magnetic detection element such as a Hall IC, a Hall element, an MR element, or a GMR element in the detection portions of both the sensors 5a and 5b.

  In the case of a rolling bearing unit for supporting a wheel of an automobile, the axial load applied between the outer ring 1 and the hub 2 is input from the ground contact surface between the outer peripheral surface of the wheel (tire) coupled to the hub 2 and the road surface. The Since this ground contact surface exists radially outward from the rotation center of the outer ring 1 and the hub 2, the axial load is not between the outer ring 1 and the hub 2 but as a pure axial load. 1 and the center axis of the hub 2 and the center of the grounding surface are applied with a moment in a virtual plane (in the vertical direction). The magnitude of this moment is proportional to the magnitude of the axial load input from the ground plane. Therefore, if this moment is obtained, this axial load can be obtained. On the other hand, when a moment is applied to the hub 2, the upper end of the encoder 4b is displaced in any direction with respect to the axial direction, and the lower end is similarly displaced in the opposite direction. As a result, the phases of the detection signals of the two sensors 5a and 5b in which the respective detection units are brought close to and opposed to the upper and lower ends of the outer peripheral surface of the encoder 4b are shifted in the opposite directions with respect to the neutral positions. Therefore, the direction and magnitude of the axial load can be obtained based on the direction and magnitude of the phase shift of the detection signals of both the sensors 5a and 5b. In the case of the fourth example of the prior invention, as in the case of the first example of the prior invention, the calculation for obtaining the moment and the axial load is performed by a calculator (not shown).

  As described above, in the case of the first to fourth examples of the present invention, since the displacement amount and the load are obtained based on the output signals of the sensors 5, 5a, 5b, and 10, the cost measurement and durability of the load measuring device are reduced. Secure enough. However, each of the prior inventions as described above has the following points to be improved regarding the arithmetic processing performed when the displacement amount and the load are obtained. This point will be described with reference to FIGS. In the case of the rolling bearing unit targeted by each of the above-described prior inventions, a load or force acting between the outer ring 1 and the hub 2 (axial load, radial load, moment, hereinafter simply referred to as load), and these outer rings 1 And the hub 2 have a relative displacement (axial displacement, radial displacement, inclination) as shown in FIG. 14A, that is, as the absolute value of the load increases. In general, a relationship {nonlinear (curve) relationship} in which the rate of change of the relative displacement with respect to the load is small is established. The reason why such a non-linear relationship is established is that as the absolute value of the relative displacement increases with the absolute value of the load, the rigidity of the rolling bearing unit increases. On the other hand, in the case of each of the above-described prior inventions, there is a difference between the relative displacement amount and change information (for example, duty ratio, phase difference) regarding the output signals of the sensors 5, 5a, 5b as shown in FIG. The following relationship {linear (straight line) relationship} is established. In the case of each of the above-described prior inventions, the reason why such a linear relationship is established is that FIG. 15 {(A) is the first example of the prior invention, (B) is the second example, and (C) is the third to third. As shown in FIG. 4}, the boundary between the part magnetized in the N pole and the part magnetized in the S pole existing on the detected surfaces of the encoders 4, 4a and 4b is { This is because (A), (C)} or each region {FIG. (B)} has a linear shape inclined with respect to the width direction of the detected surface.

  Therefore, in each of the above-described prior inventions, the relationship as shown in FIG. 14C between the change information and the load, that is, as the absolute value of the change information increases, the change information with respect to the change information becomes larger. A relationship (nonlinear relationship) in which the rate of change in load increases is established. As a result, in the case of each of the above-described prior inventions, when obtaining the load from the change information, it is necessary to perform map conversion by the arithmetic unit using a map indicating the relationship between the change information and the load. . However, when such map conversion is performed, the amount of calculation increases compared to, for example, the case where simple four arithmetic operations are performed. Accordingly, the time required to obtain the load is correspondingly increased. However, such a long time required to obtain the load is not preferable from the viewpoint of improving the reliability of the vehicle travel control. In the case of each of the above-described prior inventions, it is necessary to store the map in the memory of the arithmetic unit so that the map can be converted by the arithmetic unit. However, storing the map in the memory in this way is not preferable because the cost of the arithmetic unit increases accordingly.

  As a countermeasure for solving these problems, for example, the structure of the rolling bearing unit may be devised so that a linear relationship is established between the load and the relative displacement amount over the entire load range to be measured. Conceivable. However, adopting such a countermeasure is not preferable because the bearing performance of the rolling bearing unit is sacrificed. As another countermeasure, it is conceivable to approximate the relationship between the load and the relative displacement amount by a polynomial function instead of using a map, and obtain the load from the coefficient of the polynomial function. However, when such a countermeasure is adopted, there are many cases where the relationship between the load and the relative displacement cannot be approximated by a simple polynomial function, and a large approximation error may occur in the calculation result. . In addition, if a complex polynomial function is used to minimize this approximation error, the amount of calculation increases as in the case of the above map conversion, resulting in a disadvantage that the time required for obtaining the load becomes longer. .

JP 2001-21577 A Japanese Patent Laid-Open No. 3-209016 Japanese Patent Laid-Open No. 2004-3918 Japanese Patent Publication No.62-3365 JP 2005-31063 A

  In view of the circumstances as described above, the load measuring device of the present invention is a change related to the output signal of the sensor without using a map, even in the case of a rotation support device in which the relationship between the load and the relative displacement amount is nonlinear. The present invention was invented to realize a structure capable of easily calculating a load from information.

The load measuring device of the present invention includes an encoder, one sensor or a plurality of sensors, and a calculator.
Of these, the encoder is supported by a part of the rotating member and rotates together with the rotating member. And the to-be-detected surface which makes the direction perpendicular to the rotation direction of this rotation member the width direction is concentric with the rotation center of this rotation member is provided. Then, the first characteristic portion and the second characteristic portion having different characteristics on the detected surface are alternately arranged in the circumferential direction, and the circumference of the boundary between the first characteristic portion and the second characteristic portion is arranged. The pitch or phase related to the direction is continuously changed over the width direction of the detected surface.
The one sensor or the plurality of sensors are supported by a stationary member in a state where the detection unit faces the detection surface of the encoder. And, as the relative position between the stationary member and the rotating member changes due to the load acting between the stationary member and the rotating member, the opposing position of the detection unit with respect to the detected surface becomes The ratio of the output signal corresponding to the pattern of characteristic change in the circumferential direction of the portion of the detected surface that faces the detecting portion of the detected surface is changed (the one above) Or the phase difference between the output signals (in the case of the plurality of sensors) is changed.
The ratio regarding the output signal is the same as the ratio between the period when the potential of the output signal is higher than the reference voltage and the period when the potential of the output signal is lower, and the difference between the maximum value of the voltage of the output signal and the reference voltage. Any of the ratio of the difference between the minimum value and the reference voltage and the duty ratio of the rectangular wave signal in which the higher side of the output voltage is higher than the reference voltage and the lower side is also low. is there.
The computing unit obtains the load based on the output signal of the sensor.
In particular, in the load measuring apparatus of the present invention, the ratio of the load and the output signal of the sensor or the phase difference between the output signals is a linear function (Claim 1) or quadratic or cubic. The shape of the boundary between the first characteristic part and the second characteristic part is regulated so as to change according to the relation of the polynomial function (Claim 3).

As described above, in the case of the load measuring device according to the present invention, the ratio of the load and the output signal of the sensor or the output signals between the output signals regardless of the characteristics related to the relationship between the load magnitude and the displacement amount of the target rotation support device The phase difference between the two changes in a linear function relationship or a quadratic or cubic polynomial function . For this reason, change information regarding the output signal of the sensor (for example, duty ratio, phase difference of output signals of a plurality of sensors) also changes with a relationship of a linear function or a quadratic or cubic polynomial function with respect to the load. To do. Therefore, the calculation for obtaining the load from the change information regarding the output signal of the sensor can be easily performed by the calculator without using the map. As a result, the cost of this calculator can be reduced. At the same time, since the time required to obtain the load can be shortened, the reliability of the vehicle travel control can be improved.

  When the invention described in claim 1 is carried out, preferably, as described in claim 2, the boundary between the first characteristic portion and the second characteristic portion is defined by the relative position between the rotating member and the stationary member and the load. Or a characteristic curve showing a relationship with the characteristic curve or a mirror-symmetrical curve with this characteristic curve (it is natural to include a similar shape).

Further, when the invention described in claims 1 to 3 is carried out, for example, as described in claim 4, the width of the first characteristic portion in the circumferential direction is increased toward one side in the width direction of the detected surface, In addition, a structure is adopted in which the width of the second characteristic portion in the circumferential direction is increased toward the other side in the width direction of the detected surface.
Alternatively, as described in claim 5, the surface to be detected is divided into a plurality of regions in the width direction, and the shape of the boundary between the first characteristic portion and the second characteristic portion is made different for each region, and The shape of the boundary of at least one of these regions is regulated so that the load and the phase difference between the output signals of the plurality of sensors change in relation to a linear function or a quadratic or cubic polynomial function. . At the same time, a structure is employed in which the magnitude of the load is obtained by an arithmetic unit based on the phase difference between the output signals of a plurality of sensors having the respective detection units opposed to the respective regions.
Alternatively, as described in claim 6, the widths of the first and second characteristic portions in the circumferential direction are set constant in the width direction of the detected surface. Along with this, a structure is employed in which the magnitude of the load is obtained by an arithmetic unit based on the phase difference of the output signals of a plurality of sensors having their respective detection portions opposed to a plurality of locations in the circumferential direction of the detected surface.
Alternatively, as described in claim 7, the widths of both the first and second characteristic portions in the circumferential direction are set constant in the width direction of the detected surface. At the same time, based on the phase difference between the output signal of the sensor whose detection unit faces the detection surface and the output signal of another sensor whose detection unit faces the detection surface of another encoder, A structure is used in which the magnitude of the load is determined by an arithmetic unit.

In carrying out the present invention, preferably, as described in claim 8, the rotating member constitutes a rolling bearing unit and is rotated and fixed at the time of use. The stationary member is a stationary bearing ring that does not rotate during use by configuring the rolling bearing unit or a member that supports and fixes the stationary bearing ring.
More preferably, as described in claim 9, the rolling bearing unit is configured to support the wheels of the automobile so as to be rotatable with respect to the suspension device.

  1 and 2 show a first embodiment of the present invention corresponding to claims 1, 2, 4, 8 and 9. The feature of this embodiment is that the shape of the boundary between the part magnetized in the N pole and the part magnetized in the S pole existing on the outer peripheral surface (detected surface) of the encoder 4c is devised. . Since the structure and operation of the other parts are the same as those in the first example of the prior invention shown in FIGS. 5 to 7 and FIG. 15A, overlapping illustrations and explanations are omitted or simplified. The description will focus on the features of this embodiment.

  In the case of the present embodiment, instead of the encoder 4 having the detected surface as shown in FIGS. 6 to 7 and FIG. 15A, an encoder 4c having the detected surface as shown in FIG. use. As in the case of the encoder 4 shown in FIGS. 6 to 7 and FIG. 15A, in the case of the encoder 4c of this embodiment, a portion magnetized to the N pole existing on the outer peripheral surface that is the detected surface, Of the portion magnetized at the S pole, the width of the portion magnetized at the N pole in the circumferential direction (left and right direction in FIGS. 1 and 15) is wider as one axial side {upper side in FIGS. 1 and 15}. In addition, the width in the circumferential direction of the portion magnetized in the S pole is made wider toward the other side in the axial direction (the lower side in FIGS. 1 and 15). However, in the case of the encoder 4 shown in FIGS. 6 to 7 and FIG. 15 (A), the shape of the boundary between the portion magnetized at the N pole and the portion magnetized at the S pole is a linear shape. On the other hand, in the case of the encoder 4 of the present embodiment, the shape of the boundary between the portion magnetized at the N pole and the portion magnetized at the S pole is a curved shape. Specifically, the shape of each boundary is represented by a characteristic curve as shown in FIG. 2A {the above-mentioned FIG. 14A}, that is, the outer ring 1 and the hub 2 (see FIG. 5) of the rolling bearing unit. As the absolute value of the axial load (“load”) acting during the period increases, the rate of change in the axial relative displacement (“relative displacement”) between the outer ring 1 and the hub 2 with respect to this axial load decreases. A characteristic curve (non-linear curve) showing the following relationship or a shape that is mirror-symmetrical to the characteristic curve. More specifically, a boundary having the same shape as the characteristic curve and a boundary having the same shape as a mirror-symmetrical curve with respect to the characteristic curve are alternately arranged on the outer peripheral surface of the encoder 4c in the circumferential direction. .

By adopting such a configuration, change information (for example, the above-described relative displacement amount in the axial direction and the output signal (see FIGS. 5 and 7) of the sensor 5 opposed to the outer peripheral surface of the encoder 4c). (T _H / (T _H + T _L ))) as shown in FIG. 2B, that is, as the absolute value of the relative displacement in the axial direction increases, the relative A relationship (nonlinear curve relationship) in which the rate of change of the change information with respect to the displacement amount increases is established. Then, by establishing such a relationship {by the combination of the relationship of FIG. 2A and the relationship of FIG. 2B}, between the change information and the axial load, FIG. The linear relationship as shown in is established.

  As described above, in the case of the load measuring device of this embodiment, the change information related to the output signal of the sensor 5 and the axial load are in a linear relationship (linear function) as shown in FIG. Change. Therefore, in the case of the present embodiment, it is possible to obtain from the change information regarding the output signal of the sensor 5 only by performing a simple (primary function) arithmetic operation using the linear relationship by an arithmetic unit (not shown) without using a map. The axial load can be obtained. As a result, in the case of the present embodiment, the cost of the arithmetic unit can be reduced. At the same time, since the time required to obtain the axial load can be shortened, the reliability of the vehicle running control can be improved.

  Next, a second embodiment of the present invention corresponding to claims 1, 2, 5, 8, and 9 will be described with reference to FIG. 3 in addition to FIG. 2 used in the first embodiment. . The feature of this embodiment is that the shape of the boundary between the part magnetized in the N pole and the part magnetized in the S pole existing on the outer peripheral surface (detected surface) of the encoder 4d is devised. . Since the structure and operation of the other parts are the same as those of the second example of the prior invention shown in FIGS. 8 to 11 and FIG. 15 (B), overlapping illustrations and descriptions are omitted or simplified. The description will focus on the features of this embodiment.

  In the case of the present embodiment, instead of the encoder 4a having the detected surface as shown in FIGS. 9 to 11 and FIG. 15B, an encoder 4d having the detected surface as shown in FIG. use. As in the case of the encoder 4a shown in FIGS. 9 to 11 and FIG. 15 (B), in the case of the encoder 4d of the present embodiment shown in FIG. The direction (the width direction of this outer peripheral surface; the vertical direction in FIGS. 3 and 15) is divided into two regions adjacent to each other in the axial direction with the central portion as a boundary. The form of the boundary with the portion magnetized in the S pole is made different from each other. As a result, the axially central portion of the portion magnetized at the N pole and the portion magnetized at the S pole arranged on the outer peripheral surface is in the circumferential direction (left and right direction in FIGS. 3 and 15). The most protruding (or recessed) spindle shape. That is, in the case of the encoder 4a shown in FIGS. 9 to 11 and FIG. 15B, the shape of the boundary for each region is a linear shape, whereas in the case of the encoder 4d of the present embodiment, The shape of the boundary for each region is a curved shape. Specifically, the shape of the boundary for each of these regions is represented by a characteristic curve as shown in FIG. 2A {the above-mentioned FIG. 14A}, that is, the outer ring 1 and the hub 2 of the rolling bearing unit (FIG. 8). The characteristic curve (nonlinear curve) showing the relationship that the rate of change of the relative displacement in the axial direction of the outer ring 1 and the hub 2 with respect to the axial load decreases as the absolute value of the axial load acting between the outer ring 1 and the hub 2 increases. ), Or the same shape as a mirror-symmetrical curve with respect to this characteristic curve. More specifically, the shape of the boundary existing in the region on one side in the axial direction (upper side in FIG. 3) is made the same shape as the above characteristic curve, and the region on the other side in the axial direction (lower side in FIG. 3). The shape of the existing boundary is the same as that of a mirror-symmetrical curve with respect to the characteristic curve.

  By adopting such a configuration, change information (these are information about the relative displacement in the axial direction and the output signals (see FIGS. 8 and 11) of the pair of sensors 5 and 5 facing each region. 2 (B), that is, as the absolute value of the relative displacement amount in the axial direction increases, the relative displacement amount increases with respect to the relative displacement amount. The relationship (nonlinear relationship) in which the change rate of the change information increases is established. Then, by establishing such a relationship, a linear relationship as shown in FIG. 2C is established between the change information and the axial load.

  As described above, also in the case of the load measuring apparatus of the present embodiment, the change information regarding the output signals of the sensors 5 and 5 and the axial load change in a linear relationship as shown in FIG. . Therefore, also in the case of the present embodiment, the above-described change information regarding the output signals of the sensors 5 and 5 can be obtained by simply performing a simple four arithmetic operation using the linear relationship without using a map. Axial load can be obtained. As a result, the cost of the computing unit can be reduced. At the same time, since the time required to obtain the axial load can be shortened, the reliability of the vehicle running control can be improved.

  Next, with reference to FIG. 4 in addition to FIG. 2 used in the above-described first embodiment, the third embodiment of the present invention corresponding to claims 1, 2, 6, 7, 8, and 9 will be described. explain. The feature of this embodiment is that the shape of the boundary between the part magnetized in the N pole and the part magnetized in the S pole on the outer peripheral surface (detected surface) of the cylindrical encoder 4e is devised. In the point. Since the structure and operation of the other parts are the same as those of the third to fourth examples of the prior invention shown in FIGS. 12 to 13 and FIG. 15C, overlapping illustrations and explanations are omitted or simplified. Hereinafter, the characteristic part of the present embodiment will be mainly described.

  In the case of the present embodiment, an encoder 4e having a detected surface as shown in FIG. 4 is used instead of the encoder 4b having the detected surface as shown in FIGS. use. As in the case of the encoder 4b shown in FIGS. 12 to 13 and FIG. 15 (C), in the case of the encoder 4e of the present embodiment shown in FIG. The phase of the boundary between the magnetized portion and the portion magnetized to the S pole in the circumferential direction (the left-right direction in FIGS. 4 and 15) is expressed in the axial direction of the encoder 4e (the width direction of the outer peripheral surface. FIG. 15 (vertical direction) Continuing from one side (upper side of the figure) to the other side (lower side of the figure) in the direction from the circumferential one side (right side of the figure) to the other side (left side of the figure) Is changing. By making the shape of each boundary equal to each other, the width in the circumferential direction of the portion magnetized in the N pole and the portion magnetized in the S pole is the same in any part in the axial direction. It ’s like that. However, in the case of the encoder 4b shown in FIGS. 12 to 13 and FIG. 15C, the shape of the boundary between the portion magnetized in the N pole and the portion magnetized in the S pole is set in the axial direction. On the other hand, in the case of the encoder 4e according to the present embodiment, the shape of the boundary between the portion magnetized in the N pole and the portion magnetized in the S pole is set as a curved shape. Yes. Specifically, the shape of each boundary is a characteristic curve as shown in FIG. 2A (the above-mentioned FIG. 14), that is, the outer ring 1 of the rolling bearing unit and the hub 2 (see FIGS. 12 to 13). As the absolute value of the axial load or moment (load) acting between them increases, the relative displacement amount or inclination ("relative displacement amount") in the axial direction between the outer ring 1 and the hub 2 with respect to this axial load or moment changes. It has the same shape as a characteristic curve (nonlinear curve) showing a relationship of decreasing rate.

  Then, by adopting such a configuration, the relative displacement amount or inclination in the axial direction and the change information regarding the output signal of the sensor 5 (5a) opposed to the outer peripheral surface of the encoder 4e (this embodiment is described above). 12, the phase difference between the output signal of the sensor 5 and the output signal of the second sensor 10. Similarly, when applied to the structure of FIG. 2B), the higher the relative displacement amount or the absolute value of the inclination in the axial direction is, the larger the axial direction is. A relationship (nonlinear relationship) is established in which the rate of change of the change information with respect to the relative displacement amount or inclination is large. Then, by establishing such a relationship, a linear relationship as shown in FIG. 2C is established between the change information and the axial load or moment load.

  As described above, also in the case of the load measuring apparatus according to the present embodiment, the change information related to the output signal of the sensor 5 (5a) and the axial load or moment load are in a linear relationship as shown in FIG. It changes with. Therefore, also in the case of the present embodiment, the above-described change information regarding the output signals of the sensors 5 and 5 can be obtained by simply performing a simple four arithmetic operation using the linear relationship without using a map. Axial load or moment load can be obtained. As a result, the cost of the computing unit can be reduced. At the same time, the time required to obtain the axial load or moment load can be shortened, so that the reliability of vehicle travel control can be improved.

  In each of the above-described embodiments, the encoder is composed of a permanent magnet, the first characteristic portion provided on the detection surface of the encoder is a portion magnetized to the N pole, and the second characteristic portion is attached to the S pole. The magnetized part. However, when implementing the present invention, the encoder is made of a magnetic material, the first characteristic portion provided on the detection surface of the encoder is a convex portion, a column portion, or a tongue piece, and the second characteristic portion is a concave portion or It can be a through hole or a notch. When such an encoder made of a magnetic material is employed, a permanent magnet is incorporated on the sensor side facing the detection surface of the encoder.

  Further, in each of the embodiments described above, the detection surface of the encoder is a cylindrical surface, so that the relative displacement amount or inclination in the axial direction between the outer ring and the hub constituting the rolling bearing unit, and further, the outer ring and the hub. A structure for determining the axial load or moment load acting between the two is adopted. However, when the present invention is carried out, the relative surface in the radial direction between the outer ring and the hub is obtained by using the same principle as in each of the above-described embodiments by making the detected surface of the encoder an annular surface. The radial load acting between the outer ring and the hub can also be obtained. In this case, the boundary between the first and second characteristic portions is inclined with respect to the radial direction (a surface to be detected having a shape in which the vertical direction in FIGS. 1, 3 and 4 is the radial direction is provided).

Further, when the present invention is implemented, the degree of freedom in designing the shape of the boundary existing on the detected surface of the encoder is small, and the relationship between the change information relating to the output signal of the sensor and the load is corrected to a complete linear function relationship. Even if it is not possible, if it is corrected to a simple polynomial function (for example, a quadratic or cubic polynomial function), as in the case of the above-described embodiments, a simple four arithmetic operation using the relationship without using a map. The load can be obtained from the change information simply by performing the above.

  Further, in each of the above-described embodiments, by devising the shape of the boundary existing on the detected surface of the encoder, the magnitude of the load applied to the rolling bearing unit and the amount of displacement between the bearing rings constituting this rolling bearing unit The non-linear characteristic related to the relationship was corrected. On the other hand, when the present invention is implemented, non-linear factors other than the above (for example, non-linearity of the encoder and the arithmetic unit) are corrected by devising the shape of the boundary existing on the detected surface of the encoder. You can also do things.

The expanded view of the to-be-detected surface of the encoder which shows Example 1 of this invention. Three types of characteristic diagrams for explaining the operation of the embodiment. The expanded view of the to-be-detected surface of the encoder which shows Example 2 of this invention. The expanded view of the to-be-detected surface of the encoder which shows the same Example 3. FIG. Sectional drawing which shows the structure of the 1st example of a prior invention. The encoder is shown, (A) is a raw material, (B) is a perspective view of a finished product. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. Sectional drawing which shows the structure of the 2nd example of a prior invention. The perspective view of an encoder. The expanded view of the to-be-detected surface of an encoder. The diagram which shows the output signal of the sensor which changes with the fluctuation | variation of an axial load. Sectional drawing which shows the structure of the 3rd example of a prior invention. Sectional drawing which shows the structure of the 4th example. Three types of characteristic diagrams for explaining the problems caused by the prior invention. Similarly, the expanded view which shows three examples of the to-be-detected surface of an encoder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Hub 3 Rolling element 4, 4a-4e Encoder 5, 5a, 5b Sensor 6 Detection part 7 Combination seal ring 8 Slinger 9 Second encoder 10 Second sensor 11 Detection part 12 Support ring 13 Support ring 14 Large diameter cylindrical part 15 Cover

Claims (9)

A detected surface that is supported by a part of the rotating member and rotates with the rotating member, is concentric with the rotation center of the rotating member and has a width direction that is perpendicular to the rotating direction of the rotating member. The first characteristic portion and the second characteristic portion having different characteristics are alternately arranged in the circumferential direction, and the pitch or position in the circumferential direction of the boundary between the first characteristic portion and the second characteristic portion is set as described above. An encoder that is continuously changed in the width direction of the surface to be detected, and a detector that is supported by a stationary member with the detection portion facing the surface to be detected of the encoder, and between the stationary member and the rotating member As the relative position of the stationary member and the rotating member changes due to the action of a load, the opposing position of the detection unit with respect to the detected surface changes in the width direction of the detected surface, and the detected Plane Chi the detection unit corresponding to the pattern of the characteristic change in the circumferential direction of the opposite is not part of a plurality of sensors for changing the phase difference between the one sensor or output signals with each other to change the ratio for that output signal And an arithmetic unit that obtains the load based on the output signals of the one sensor or the plurality of sensors , and the ratio relating to the output signal is low when the potential of the output signal is higher than the reference voltage. The ratio between the period, the ratio between the maximum value of the voltage of the output signal and the reference voltage, the difference between the minimum value and the reference voltage, and the high level of the output signal higher than the reference voltage. and then also at the low side to the load measuring device is one of a duty ratio of the Low level to the square wave signal, and the load, and the phase difference between the ratio or the output signal to each other about said output signal As changes in relation to a linear function with each other, the load measuring device, characterized in that the regulating the shape of the boundary between the first characteristic portion and the second characteristic portion.   The boundary between the first characteristic part and the second characteristic part has the same shape as the characteristic curve showing the relationship between the amount of change in the relative position between the rotating member and the stationary member and the magnitude of the load, or a mirror-symmetrical curve with this characteristic curve. The load measuring device according to claim 1. A detected surface that is supported by a part of the rotating member and rotates with the rotating member, is concentric with the rotation center of the rotating member and has a width direction that is perpendicular to the rotating direction of the rotating member. The first characteristic portion and the second characteristic portion having different characteristics are alternately arranged in the circumferential direction, and the pitch or position in the circumferential direction of the boundary between the first characteristic portion and the second characteristic portion is set as described above. An encoder that is continuously changed in the width direction of the surface to be detected, and a detector that is supported by a stationary member with the detection portion facing the surface to be detected of the encoder, and between the stationary member and the rotating member As the relative position of the stationary member and the rotating member changes due to the action of a load, the opposing position of the detection unit with respect to the detected surface changes in the width direction of the detected surface, and the detected Plane Chi the detection unit corresponding to the pattern of the characteristic change in the circumferential direction of the opposite is not part of a plurality of sensors for changing the phase difference between the one sensor or output signals with each other to change the ratio for that output signal And an arithmetic unit that obtains the load based on the output signals of the one sensor or the plurality of sensors , and the ratio relating to the output signal is low when the potential of the output signal is higher than the reference voltage. The ratio between the period, the ratio between the maximum value of the voltage of the output signal and the reference voltage, the difference between the minimum value and the reference voltage, and the high level of the output signal higher than the reference voltage. and to also at the load measuring device is one of a duty ratio of the Low level to the square wave signal to low side, and the phase difference between the ratio or the output signal to each other about the load and the output signal As changes in relation to each other secondary or tertiary polynomial function, the load measuring device, characterized in that the regulating the shape of the boundary between the first characteristic portion and the second characteristic portion.   The width of the first characteristic part in the circumferential direction is wider toward one side in the width direction of the detected surface, and the width of the second characteristic part in the circumferential direction is wider toward the other side in the width direction of the detected surface. The load measuring apparatus described in any one of them. The detected surface is divided into a plurality of regions in the width direction, and the shape of the boundary between the first characteristic portion and the second characteristic portion is made different for each region, and the boundary of at least one of these regions is The shape is regulated so that the load and the phase difference between the output signals of the plurality of sensors change in relation to each other by a linear function or a quadratic or cubic polynomial function. obtains the magnitude of the load based on the phase difference between the output signal between the respective sensors are opposed to each detection unit, the load measuring apparatus according to any one of claims 1 to 3.   The widths of the first and second characteristic portions in the circumferential direction are constant with respect to the width direction of the surface to be detected, and the arithmetic unit makes each detection portion face a plurality of locations in the circumferential direction of the surface to be detected. The load measuring device according to any one of claims 1 to 3, wherein a load magnitude is obtained based on a phase difference between output signals of a plurality of sensors.   The widths of the first and second characteristic portions in the circumferential direction are constant with respect to the width direction of the surface to be detected, respectively, and the calculator outputs an output signal of a sensor having the detection portion opposed to the surface to be detected; The magnitude of a load is calculated according to any one of claims 1 to 3, wherein a magnitude of a load is obtained based on a phase difference with an output signal of another sensor whose detection unit is opposed to a detection surface of another encoder. Load measuring device.   The rotating member is a rotating bearing ring that constitutes a rolling bearing unit and rotates during use, or a member that is coupled and fixed to the rotating bearing ring, and the stationary member does not rotate even when used by constituting the rolling bearing unit. The load measuring device according to any one of claims 1 to 7, wherein the load measuring device is a stationary side ring or a member that supports and fixes the stationary side ring.   The load measuring device according to claim 8, wherein the rolling bearing unit rotatably supports the wheel of the automobile with respect to the suspension device.

Images