JP2008122171A - Method of exchanging sensor of bearing unit with state quantity measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an exchange method of both sensors 6a, 6b, even when the predetermined relationship between the phase difference, existing between the output signals of these both 6a, 6b sensors, and an axial load, applying between an outer wheel 1 and a hub 2, is changed with the exchange of sensors 6a, 6b, capable of precisely measuring the axial load based on the phase difference after the exchange. <P>SOLUTION: The predetermined relationship is reviewed before resuming to use after exchanging the both sensors 6a, 6b. Thereafter, the predetermined relationship stored in the memory of a computing unit is compensated to this reviewed predetermined relationship. With this, the problem is solved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention comprises a rolling bearing unit and a state quantity measuring device for measuring a state quantity such as a load acting between a stationary side bearing ring and a rotating side bearing ring constituting the rolling bearing unit. The present invention relates to a method for replacing a sensor constituting the state quantity measuring device, which is implemented for a rolling bearing unit with a quantity measuring device.

  For example, automobile wheels are rotatably supported by a suspension device by a double-row angular type rolling bearing unit. In order to ensure the running stability of the automobile, for example, as described in Non-Patent Document 1, an antilock brake system (ABS), a traction control system (TCS), and an electronically controlled vehicle stability A vehicle travel stabilization device such as a control system (ESC) is used. In order to control such various vehicle running stabilization devices, signals representing the rotational speed of the wheels, acceleration in each direction applied to the vehicle body, and the like are required. In order to perform higher-level control, it may be preferable to know the magnitude of a load (for example, one or both of a radial load and an axial load) applied to the rolling bearing unit via a wheel.

  In view of such circumstances, Patent Document 1 discloses a radial applied to a rolling bearing unit based on the revolution speed of a pair of balls constituting a rolling bearing unit which is a double-row angular ball bearing unit. An invention relating to a rolling bearing unit with a state quantity measuring device that measures a load or an axial load (a structure that is an object of implementation of the invention described in claim 3 of the claims) is described. Such a rolling bearing unit with a state quantity measuring device described in Patent Document 1 obtains the revolution speed of the balls in both rows as the rotation speed of a pair of cages holding these balls. Based on the revolution speed of the ball, the radial load or the axial load is calculated. In the case of such a rolling bearing unit with a state quantity measuring device, the balls in both rows are caused by a gap that inevitably exists between the rolling surfaces of the balls and the pockets of the cages. There may be a slight deviation between the revolution speed of the cage and the rotational speed of the two cages. For this reason, there is room for improvement in order to increase the measurement accuracy of the radial load or the axial load.

  On the other hand, as a structure capable of preventing the deterioration of measurement accuracy based on the inevitable deviation as described above, Patent Document 2 discloses a structure based on the phase difference between the output signals of a pair of sensors arranged in the load acting direction. An invention for measuring the magnitude of a load applied to a rolling bearing unit (a structure to be an object of the invention described in claim 2 of the claims) is described. FIGS. 2 to 4 are not related to the structure described in Patent Document 2, but are related to a rolling bearing unit with a state quantity measuring device that employs the same load measurement principle as the structure described in Patent Document 2. 1 shows a first example of the structure of the invention. The first example of the structure of the prior invention is a hub that is a rotating side race ring that rotates together with the wheel while being supported and fixed to the inner diameter side of the outer race 1 that is a stationary side race ring that does not rotate during use. 2 is rotatably supported via a plurality of rolling elements 3 and 3. A preload is applied to each of the rolling elements 3 and 3 together with contact angles that are opposite to each other (in the illustrated case, a rear combination type). In the illustrated example, a ball is used as the rolling element 3, but in the case of an automobile bearing unit that is heavy, a tapered roller may be used instead of the ball.

  Further, the inner end of the hub 2 {"inner" in relation to the axial direction means the center side in the width direction of the vehicle in the assembled state to the automobile, and is the right side in FIGS. On the contrary, the left side of FIGS. 1, 2, 5, and 7 which is outside in the width direction of the vehicle in the assembled state in the automobile is referred to as “outside” in the axial direction. Same throughout this specification. }, A cylindrical encoder 4 is supported and fixed concentrically with the hub 2. In addition, a pair of sensors 6a and 6b are held inside a bottomed cylindrical cover 5 (sensor cover) that closes the inner end opening of the outer ring 1, and the detection portions of both the sensors 6a and 6b are provided as described above. The encoder 4 is placed in close proximity to the outer peripheral surface, which is the detected surface.

  Of these, the encoder 4 is made of a magnetic metal plate. In the front half of the outer peripheral surface of the encoder 4 (the inner half in the axial direction), which is the detection surface, the through holes 7 and 7 and the column portions 8 and 8 are alternately arranged at equal intervals in the circumferential direction. It is arranged. The boundaries between the through holes 7 and 7 and the pillars 8 and 8 are inclined by the same angle with respect to the axial direction (width direction) of the detection surface, and the inclination direction with respect to the axial direction is determined as the detection target. The directions are opposite to each other with the axial middle portion of the surface as a boundary. Accordingly, each of the through holes 7 and 7 and each of the column portions 8 and 8 has a “h” shape (or “k” shape) in which an intermediate portion in the axial direction protrudes most in the circumferential direction. And among the axially outer half part and the axially inner half part of the detected surface, the inclination directions of the boundaries are different from each other, the axially outer half part is defined as the first characteristic changing part 9, and the axially inner half part is formed. This portion is the second characteristic changing portion 10. In addition, each through-hole which comprises both these characteristic change parts 9 and 10 may be formed in the mutually continuous state like illustration, and may be formed in the mutually independent state. Further, although the detection accuracy is inferior, only the boundary of one of the characteristic change parts 9 and 10 is inclined with respect to the axial direction, and the boundary of the other characteristic change part is parallel to the axial direction. You can also do it.

  The cover 5 is formed in a bottomed cylindrical shape entirely by a metal plate such as a stainless steel plate, and is fitted and fixed to the inner end portion of the outer ring 1. Such a cover 5 has a cylindrical portion 11 whose outer end portion is fitted and fixed to the inner end portion of the outer ring 1 by an interference fit (in the illustrated example, the inner fit is fixed), and an inner end opening of the cylindrical portion 11. And a bottom plate portion 12 that closes the door.

  The pair of sensors 6 a and 6 b is held at the lower end portion of the inner peripheral surface of the cylindrical portion 11 constituting the cover 5. Each of these sensors 6a and 6b is composed of a permanent magnet and a magnetic sensing element such as a Hall IC, a Hall element, an MR element, and a GMR element that constitute a detection unit. Of these two sensors 6a and 6b, the detection part of one sensor 6a is close to the first characteristic change part 9 and the detection part of the other sensor 6b is close to the second characteristic change part 10, respectively. Yes. The positions where the detection parts of both the sensors 6a and 6b face the characteristic change parts 9 and 10 are the same position (the lower end in the illustrated example) in the circumferential direction of the encoder 4. Further, in the state where an axial load does not act between the outer ring 1 and the hub 2, the portion that protrudes most in the circumferential direction in the axial direction intermediate portion of each of the through holes 7 and 7 and the column portions 8 and 8 (boundary boundary). The position where each member is installed is regulated so that the portion in which the inclination direction changes) is just at the center position between the detection parts of the sensors 6a and 6b.

  In the case of a rolling bearing unit with a state quantity measuring device 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), both the sensors The phase at which the output signals 6a and 6b change is shifted. That is, in the neutral state where an axial load is not applied between the outer ring 1 and the hub 2, the detection portions of the sensors 6a and 6b 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. Therefore, the phases of the output signals of the sensors 6a and 6b coincide as shown in FIG.

  On the other hand, when a downward axial load acts on the hub 2 to which the encoder 4 is fixed as shown in FIG. 4A, the detecting portions of the sensors 6a and 6b are shown in FIG. , Opposite to the portions where the deviations in the axial direction from the most protruding portion are different from each other. In this state, the phases of the output signals of the sensors 6a and 6b are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 2 to which the encoder 4 is fixed as shown in FIG. 4A, the detecting portions of both the sensors 6a and 6b are connected to the chain line H shown in 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 6a and 6b are shifted as shown in FIG.

  As described above, in the case of the first example of the structure of the previous invention, the phase of the output signals of the two sensors 6a and 6b is the direction of action of the axial load applied between the outer ring 1 and the hub 2 (these outer rings 1 and the hub 2 are displaced in the direction corresponding to the axial direction of relative displacement). Further, the degree of the phase shift of the output signals of the sensors 6a and 6b due to the axial load (relative displacement) increases as the axial load (relative displacement) increases. Therefore, the direction and magnitude of the relative displacement in the axial direction between the outer ring 1 and the hub 2 based on the presence or absence of the phase shift of the output signals of the sensors 6a and 6b and the direction and magnitude of the deviation, if any. In addition, the acting direction and magnitude of the axial load acting between the outer ring 1 and the hub 2 can be obtained. The processing for calculating the relative displacement and load in the axial direction based on the phase difference between the output signals of the two sensors 6a and 6b is performed by a calculator (not shown). For this reason, the relationship between the phase difference, the relative displacement in the axial direction, and the load, which has been examined in advance by theoretical calculation or experiment, is stored in the memory of this arithmetic unit as a relational expression or a map type. .

  In the case of the first example of the structure of the above-described invention, a sensor set including a pair of sensors 6a and 6b in which the respective detection units are opposed to the first and second characteristic change units 9 and 10, respectively. Only one set is provided. On the other hand, although not shown in the drawings, Japanese Patent Application Nos. 2006-143097 and 2006-214197 are provided with a plurality of sensor sets each consisting of a pair of sensors to obtain multi-directional displacement or external force. The resulting structure is disclosed.

  Next, FIGS. 5-6 has shown the 2nd example of the structure of prior invention regarding the rolling bearing unit with a state quantity measuring apparatus. In the case of the second example of the structure of the prior invention, slit-shaped through holes 7a and 7a and a column portion are formed on the tip half of a cylindrical encoder 4a made of a magnetic metal plate and fixedly fitted to the inner end of the hub 2. 8a and 8a are alternately arranged at equal intervals in the circumferential direction. The boundaries between the through holes 7a and 7a and the pillars 8a and 8a are linear shapes that are inclined by the same angle in the same direction with respect to the axial direction of the encoder 4a. Further, a pair of sensors 6 a and 6 b supported on the inner end of the outer ring 1 via a cover 5 (sensor cover) are provided, one on each of the upper and lower ends of the inner peripheral surface of the cylindrical portion 11 constituting the cover 5. keeping. The detection parts of both the sensors 6a and 6b are close to and opposed to two upper and lower positions on the outer peripheral surface of the front half of the encoder 4a, which is the detection surface.

  In the case of a rolling bearing unit for supporting a wheel of an automobile, an axial load applied between the outer ring 1 and the hub 2 is input from a ground contact surface between a tire outer peripheral surface and a road surface constituting a wheel coupled and fixed to the hub 2. Is done. 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). When such a moment is applied between the outer ring 1 and the hub 2, the central axis of the hub 2 is inclined with respect to the central axis of the outer ring 1. Accordingly, the upper end of the encoder 4a 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 output signals of the sensors 6a and 6b, in which the detection units are placed close to and opposed to the upper and lower ends of the outer peripheral surface of the encoder 4a, are shifted in the opposite directions with respect to the neutral positions. Therefore, the action direction and magnitude of the axial load can be obtained based on the direction and magnitude of the phase shift of the output signals of both sensors 6a, 6b.

  Next, FIGS. 7-8 has shown the 3rd example of the structure of a prior invention regarding the rolling bearing unit with a state quantity measuring device. In the case of the third example of the structure of the prior invention, the through holes 7b and 7b and the column portions 8b and 8b are formed on the tip half of the cylindrical encoder 4b made of a magnetic metal plate and fitted and fixed to the inner end of the hub 2. Are arranged alternately at equal intervals in the circumferential direction. Each of these through holes 7b and 7b has a trapezoidal shape as viewed from the radial direction, and gradually changes the width dimension in the circumferential direction with respect to the axial direction. A single sensor 6 a supported on the inner end of the outer ring 1 via a cover 5 (sensor cover) is held at the lower end of the inner peripheral surface of the cylindrical portion 11 constituting the cover 5. And the detection part of this one sensor 6a is made to oppose and adjoin the lower end part of the front-end | tip half outer peripheral surface of the said encoder 4b which is a to-be-detected surface. In the case of the third example of the structure of the prior invention configured as described above, when the outer ring 1 and the hub 2 are relatively displaced in the axial direction based on the axial load, the duty ratio (high potential duration time) of the output signal of the sensor 6a. / 1 period) changes. Therefore, based on this duty ratio, the direction and magnitude of the relative displacement, and further the direction and magnitude of the axial load can be obtained.

  In the case of the structure of each of the prior inventions described above, the encoder is made of a magnetic metal plate, the first characteristic portion provided on the detection surface of the encoder is a through hole, and the second characteristic portion is a column portion. The configuration is adopted. On the other hand, the encoder is made 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 a portion magnetized to the S pole. Can also be adopted. When such a configuration is employed, it is not necessary to incorporate a permanent magnet on the sensor side. Further, in the case of the structure of each of the above-described prior inventions, a configuration is adopted in which the detection surface of the encoder is a cylindrical surface and the detection portion of the sensor is opposed to the detection surface in the radial direction. On the other hand, if the detection surface of the encoder is an annular surface, and the configuration in which the detection portion of the sensor is opposed to the detection surface in the axial direction, the relative displacement in the radial direction between the outer ring and the hub, and A radial load acting between the outer ring and the hub can be obtained.

  As described above, regarding the above-described rolling bearing unit with a state quantity measuring device, the state quantity between the outer ring 1 and the hub 2 {the axial load acting between the outer ring 1 and the hub 2 or these Relative displacement in the axial direction between the outer ring 1 and the hub 2 and information on the output signal of the sensor 6a (6b) {the phase difference ratio (phase difference) existing between the output signals of the pair of sensors 6a and 6b / 1 period) or the duty ratio of the output signal of one sensor 6a}. Therefore, it is assumed that a relationship as indicated by a solid line α in FIG. 9 is established as the predetermined relationship. The gain characteristic (gradient at each point of the solid line α) and the zero point {the value of the phase difference ratio (duty ratio) when the axial load (relative displacement) = 0} regarding the predetermined relationship} are: Characteristics of the detection surface of the encoder 4 (4a, 4b) (characteristic boundary change pattern), characteristics of the detection part of the sensor 6a (6b) (output characteristics), and the positions of the detection surface and the detection part It is specifically determined by a plurality of factors such as the relationship and the rigidity of the rolling bearing unit (mainly the preload applied to the rolling elements 3 and 3). In any case, it is assumed that the relationship indicated by the solid line α is stored in the memory of the arithmetic unit constituting the rolling bearing unit with each state quantity measuring device.

  On the other hand, for example, when the sensor 6a (6b) constituting the rolling bearing unit with each state quantity measuring device is replaced during maintenance of the vehicle, first, the rolling bearing unit with each state quantity measuring device (vehicle) A part other than the above-mentioned computing unit attached separately to a part of the computer. Next, after removing the cover 5 holding the sensor 6a (6b) from the inner end of the outer ring 1, the cover 5 holding a new sensor 6a (6b) is attached to the inner end of the outer ring 1. Assemble. However, if the sensor 6a (6b) is replaced in this way, it is caused by a manufacturing error of the cover 5 (sensor cover unit) holding the new sensor 6a (6b) or an assembly error of the cover 5 with respect to the outer ring 1. Thus, the positional relationship between the detection part of the sensor 6a (6b) and the detected surface of the encoder 4 (4a, 4b) is slightly different before and after the exchange {if the assembly error is temporarily eliminated. Even so, the deviation is always within the range of the manufacturing error (tolerance). As a result, the predetermined relationship changes by an amount corresponding to the positional relationship shift, for example, as indicated by the solid line α → broken line β in FIG.

  Regarding the change in the predetermined relationship at this time, as can be seen by comparing the solid line α and the broken line β, there is almost no change in the gain characteristic (so small that it can be ignored), and the change in the zero point is dominant. It becomes the target. The reason for this is as follows. That is, the change in the gain characteristic occurs when the positional relationship is shifted in the circumferential direction before and after the replacement, whereas the change in the zero point causes the positional relationship to be shifted in the axial direction before and after the replacement. Caused by. However, the change rate of the gain characteristic is only slightly generated based on the inclination of the central axes of the outer ring 1 and the hub 2 and is very small, whereas the change rate of the zero point is quite large. For this reason, with respect to the change in the predetermined relationship that occurs when the positional relationship is shifted before and after the replacement, there is almost no change in the gain characteristic (so small that it can be ignored), and the change in the zero point is dominant. . In any case, since the predetermined relationship changes before and after the exchange (from the solid line α to the broken line β), the relationship stored in the memory before the exchange (shown by the solid line α). If this relationship is used as it is after this exchange, the state quantity cannot be measured accurately. Therefore, it is desirable to be able to avoid such a situation.

JP 2005-31063 A JP 2006-1113017 A Motoo Aoyama, “Red Badge Super Illustrated Series / A book that shows the latest mechanics of cars”, p. 138-139, p. 146-149, Sangensha Co., Ltd./Kodansha Co., Ltd., December 20, 2001

  In view of the circumstances as described above, the present invention provides a predetermined relationship established between the state quantity between the stationary-side raceway and the rotation-side raceway and information related to the output signal of the sensor, as the sensor is replaced. The present invention has been invented to realize a sensor replacement method capable of accurately measuring the state quantity based on the information after the replacement even when the relationship changes.

Of the present invention, a rolling bearing unit with a state quantity measuring device, which is an object of the sensor replacement method described in claim 1 of the claims, includes a rolling bearing unit and a state quantity measuring device.
Of these, the rolling bearing unit has two rows on each of the stationary bearing rings that do not rotate when used, the rotating bearing rings that rotate when used, and the circumferential surfaces of the stationary bearing ring and the rotating bearing ring facing each other. A plurality of rolling elements are provided between the stationary-side track and the rotating-side track, each of which is formed so as to be able to roll with a contact angle direction opposite to each other between a pair of rows.
Further, the state quantity measuring device is configured to obtain at least one state quantity of a relative displacement between the stationary side raceway and the rotation side raceway and an external force acting between the two raceways. It measures and comprises a sensor device and a calculator.
Of these, the sensor device is supported by a portion that does not rotate during use, and includes one or more sensors.
Further, the arithmetic unit stores a predetermined relationship (relational expression or map) established between the state quantity and the information on the output signals of the one or more sensors in the memory, and In use, this predetermined relationship is used to calculate the state quantity based on the information.
The sensor replacement method according to claim 1, which is intended for such a rolling bearing unit with a state quantity measuring device, discontinues use of the rolling bearing unit with a state quantity measuring device. After the replacement, the predetermined relationship is reexamined before the use of the rolling bearing unit with the state quantity measuring device is resumed. Then, the predetermined relationship stored in the memory of the arithmetic unit is corrected to the reexamined predetermined relationship.

When carrying out the invention described in claim 1 described above, for example, the structure described in claims 2 to 3 of the claims can be adopted as a rolling bearing unit with a state quantity measuring device. .
In the case of the structure described in claim 2, the state quantity measuring device includes an encoder. The encoder is supported and fixed directly on a part of the rotation side raceway or through another member, and has a detection surface concentric with the rotation side raceway, and the characteristics of the detection surface are determined. While alternately changing in the circumferential direction, the phase or pitch at which the characteristics of the detected surface change in the circumferential direction is continuously changed in the width direction in at least a part of the width direction of the detected surface. Yes.
In the sensor device, the detection unit of one or a plurality of sensors is opposed to the detection surface, and at least one of the detection units of the sensor device has the characteristic change in the detection surface. The one or more sensors each change an output signal corresponding to a change in the characteristics of the detected surface.
Further, the computing unit stores a predetermined relationship established between the state quantity to be measured and the information on the output signals of the one or more sensors in the memory, and at the time of use, Using this predetermined relationship, it has a function of calculating the state quantity based on the information.

In contrast, in the case of the structure described in claim 3, the sensor device includes a pair of revolution speed detection sensors for detecting the revolution speed of the rolling elements in each row as one or a plurality of sensors. Prepare.
The computing unit stores in the memory a predetermined relationship established between the state quantity to be measured and the information related to the output signal of the pair of revolution speed detection sensors, and is used. Sometimes, using this predetermined relationship, the state quantity is calculated based on the information.

Further, when carrying out the invention described in claims 1 to 3 described above, for example, as described in claim 4 of the scope of claims, the rotating side race ring is arranged with respect to the stationary side race ring. While rotating, the predetermined relationship is reexamined.
In carrying out the invention described in claims 1 to 4, preferably, as described in claim 5 of the claims, the subject rolling bearing unit is used for supporting the wheels of an automobile. A hub unit is used. That is, the present invention is intended for a rolling bearing unit for supporting a wheel, in which the stationary bearing ring is supported by a vehicle suspension device and the wheel is coupled and fixed to a hub that is a rotating bearing ring.

  As described above, the sensor replacement method of the rolling bearing unit with the state quantity measuring device according to the present invention is based on the state quantity between the stationary side raceway and the rotary side raceway and the output of the sensor. Even when the predetermined relationship established with the information regarding the signal changes, the predetermined relationship stored in the memory of the arithmetic unit is corrected to the predetermined relationship after the change after the exchange. For this reason, after the exchange, the state quantity can be accurately measured based on the information.

  FIG. 1 shows an example of an embodiment of the present invention corresponding to claims 1, 2, 4, and 5 of the claims. The feature of this example is in a method of exchanging a pair of sensors 6a and 6b for the rolling bearing unit with a state quantity measuring device shown in FIGS. The structure and operation of this state quantity measuring device-equipped rolling bearing unit are as described above, and therefore, overlapping illustrations and descriptions are omitted or simplified, and the following description will focus on the features of this example. In this example, there is an axial load acting between the outer ring 1 and the hub 2 and the output signals of the sensors 6a and 6b before the sensors 6a and 6b are replaced. As a predetermined relationship established with respect to the phase difference ratio, a relationship indicated by a solid line α in FIG. 9 is established, and the relationship indicated by the solid line α is stored in a memory of a calculator (not shown). The following explanation will be given on the assumption that this is done.

  Also in the case of this example, as in the case of the above-described prior art, for example, when replacing the pair of sensors 6a and 6b constituting the rolling bearing unit with the state quantity measuring device at the time of vehicle maintenance, The rolling bearing unit with the state quantity measuring device (the part other than the arithmetic unit separately attached to a part of the vehicle) is removed from the vehicle. Next, after removing the cover 5 holding the sensors 6a and 6b from the inner end of the outer ring 1, the cover 5 holding new sensors 6a and 6b is assembled to the inner end of the outer ring 1. When the sensors 6a and 6b are exchanged in this way, as described above, the mutual positional relationship between the detection portions of both the sensors 6a and 6b and the detected surface of the encoder 4 is slightly shifted before and after the exchange. . As a result, the predetermined relationship changes, for example, as shown by the solid line α → broken line β in FIG. Therefore, in the case of this example, after replacing both sensors 6a and 6b as described above, the predetermined relationship after the change is examined before the rolling bearing unit with the state quantity measuring device is reassembled into the vehicle. However, only the zero point of the zero point and the gain characteristic related to the predetermined relationship after the change is examined here. The reason for this is that, as described above, with respect to the change in the predetermined relationship accompanying the shift in the positional relationship, there is almost no change in the gain characteristic (small enough to be ignored), and the change in the zero point is dominant. It is. That is, as long as the zero point after the change is known, the predetermined relationship after the change can be accurately grasped.

  In this example, a test apparatus as shown in FIG. 1 is used to check the zero point after the change. The test apparatus includes a support base 13, a rotation drive device 14, a load meter 15, a coupling 16, and a test arithmetic device 17. When the zero point after the change is examined using such a test apparatus, the outer ring 1 and the hub 2 are supported with the outer ring 1 supported and fixed by the support base 13 as shown in FIG. The hub 2 is rotationally driven through the coupling 16 by the rotational driving device 14 without applying an axial load between the two. In this state, the signal representing the axial load acting between the outer ring 1 and the hub 2 and the output signals of the sensors 6a and 6b, measured by the load meter 15, respectively, It inputs into the arithmetic unit 17 for a test. The test arithmetic unit 17 confirms that the axial load is not acting on the basis of the signal sent from the load meter 15, while the output signals of the two sensors 6a and 6b are in between. Is measured, that is, the zero point after the change.

  If the zero point after the change is measured in this way, then, the rolling bearing unit with the state quantity measuring device is reassembled in the vehicle, and the zero point after the change is read into the memory of the arithmetic unit, A predetermined relationship (relation indicated by the solid line α) stored in the memory is corrected. Specifically, the zero point of this predetermined relationship is changed to the zero point after the change (in FIG. 9, the solid line α is translated so that the zero point of the solid line α becomes the zero point after the change). Make corrections. As a result, the predetermined relationship after correction is substantially equal to the predetermined relationship after replacement (relation indicated by the broken line β). Therefore, in the case of this example, the axial load can be accurately measured using the predetermined relationship after the correction when the vehicle is subsequently driven.

  In the above-described embodiment, when measuring the zero point after the change, the hub is rotated by the rotary drive device. However, in order to perform this measurement work more easily, the hub may be rotated manually. it can. Further, this measurement work can be performed in a state where the rolling bearing unit with the state quantity measuring device is reassembled to the vehicle. In this case, the hub may be rotated without supporting and fixing the wheel, or may be rotated with the wheel supported and fixed. Further, in this case, the zero point after the change may be measured by using a test arithmetic unit constituting the test apparatus as in the above-described embodiment, or the state quantity measuring apparatus may be You may measure using the calculating unit to comprise. Further, when the zero point after the change is measured using the test arithmetic device, the measured zero point may be read by a wire to the arithmetic unit, or one of the bearing units. It may be read using a bar code, a QR code, an IC tag (wireless IC), or the like attached to the part.

  Further, in the above-described embodiment, the present invention is implemented for the first example of the structure of the prior invention shown in FIGS. However, the present invention is not limited to this. Patents such as the structure of the other prior invention described above (target structure of claim 2) and the structure described in the above-mentioned patent document 1 (target structure of claim 3), etc. The present invention can be implemented for various rolling bearing units with state quantity measuring devices that satisfy the requirements described in the claims.

  The state quantity (relative displacement, external force) between the stationary side bearing ring and the rotating side bearing ring, and information on the output signal of the sensor (phase difference ratio, The factors that change the predetermined relationship established between the duty ratio and the revolution speed of the rolling elements in each row) are the factors described above, that is, the sensor detection unit and the encoder In addition to the factor that the mutual positional relationship with the surface to be detected is shifted (first factor), the factor that the output characteristics of this sensor are different before and after sensor replacement (second factor) There is a factor (third factor) that the preload applied to the plurality of rolling elements constituting the rolling bearing unit decreases. However, regarding the second factor, the new sensor after replacement has the same output characteristics as the old sensor before replacement (for this purpose, the output characteristics of the new sensor are inspected in advance). Thus, the predetermined relationship can be prevented from changing due to the second factor. As for the third factor, for example, by the method disclosed in Japanese Patent Application No. 2006-65675, the predetermined relationship changed by the third factor can be corrected while measuring the preload during driving of the vehicle. For these reasons, in the above-described embodiment, an example in which only the first factor is considered (ignoring the second and third factors) and the predetermined relationship is corrected has been described.

  However, when the present invention is implemented, the predetermined relationship changed by the second factor and the third factor together with the first factor can be corrected. However, unlike the first factor, each of the second and third factors changes not only the zero point of the predetermined relationship but also the gain characteristic relatively large. For this reason, when the predetermined relationship is corrected after sensor replacement, it is necessary to reexamine not only the zero of the predetermined relationship but also the gain characteristics in advance.

The figure which shows the condition which correct | amends the predetermined relationship memorize | stored in the memory of a calculator which shows an example of embodiment of this invention. Sectional drawing which shows the 1st example of the structure of the prior invention regarding a rolling bearing unit with a state quantity measuring device. The figure which looked at a part of encoder incorporated in this 1st example from the diameter direction. 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 2nd example of the structure of the prior invention regarding a rolling bearing unit with a state quantity measuring device. The figure which looked at a part of encoder incorporated in this 2nd example from the diameter direction. Sectional drawing which shows the 3rd example of the structure of the prior invention regarding a rolling bearing unit with a state quantity measuring device. The figure which looked at a part of encoder incorporated in this 3rd example from the diameter direction. The diagram which shows the relationship between the state quantity (axial load or relative displacement) between an outer ring | wheel and a hub, and the information (phase difference ratio or duty ratio) regarding the output signal of a sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer ring 2 Hub 3 Rolling element 4, 4a, 4b Encoder 5 Cover 6a, 6b Sensor 7, 7a, 7b Through-hole 8, 8a, 8b Column part 9 First characteristic change part 10 Second characteristic change part 11 Cylindrical part DESCRIPTION OF SYMBOLS 12 Bottom plate part 13 Support stand 14 Rotation drive device 15 Load meter 16 Coupling 17 Computing device

Claims (5)

A rolling bearing unit and a state quantity measuring device;
Of these, the rolling bearing unit has two rows on each of the stationary bearing rings that do not rotate when used, the rotating bearing rings that rotate when used, and the circumferential surfaces of the stationary bearing ring and the rotating bearing ring facing each other. A plurality of rolling elements are provided between the stationary-side track and the rotating-side track, each of which is formed so as to be able to roll with a contact angle direction opposite to each other between a pair of rows. Is,
The state quantity measuring apparatus measures at least one state quantity of a relative displacement between the stationary side raceway and the rotation side raceway and an external force acting between the two raceways. It has a sensor device and an arithmetic unit,
Among these, the sensor device is supported by a portion that does not rotate during use and includes one or more sensors.
The computing unit stores in the memory a predetermined relationship established between the state quantity and the information relating to the output signals of the one or more sensors, and the predetermined relationship at the time of use. And has a function of calculating the state quantity based on the information.
A sensor replacement method for a rolling bearing unit with a state quantity measuring device, comprising:
After stopping the use of the rolling bearing unit with the state quantity measuring device and replacing the sensor, before resuming the use of the rolling bearing unit with the state quantity measuring device, reexamine the predetermined relationship and calculate A method for replacing a sensor of a rolling bearing unit with a state quantity measuring device, wherein the predetermined relationship stored in the memory of the vessel is corrected to the predetermined relationship that has been reexamined. Regarding the rolling bearing unit with state quantity measuring device
The state quantity measuring device includes an encoder, and this encoder is supported and fixed directly on a part of the rotation side raceway or through another member, and has a detected surface concentric with the rotation side raceway. In addition, the characteristics of the surface to be detected are alternately changed with respect to the circumferential direction, and the phase or pitch at which the characteristics of the surface to be detected changes with respect to the circumferential direction is determined in at least a part of the width direction of the surface to be detected. The width direction is continuously changed,
In the sensor device, the detection unit of one or more sensors is opposed to the detection surface, and the detection unit of at least one of them is set to the phase of the characteristic change or the phase of the detection surface. The pitch is opposed to a portion that continuously changes in the width direction, and each of the one or more sensors changes an output signal in response to a change in characteristics of the detected surface.
The computing unit stores in the memory a predetermined relationship established between the state quantity to be measured and the information related to the output signals of the one or more sensors, and the predetermined amount is used during use. Using a relationship, it has a function to calculate the state quantity based on the information,
A method for replacing a sensor of a rolling bearing unit with a state quantity measuring device according to claim 1. Regarding the rolling bearing unit with state quantity measuring device
The sensor device includes a pair of revolution speed detection sensors for detecting the revolution speed of the rolling elements in each row as one or a plurality of sensors.
The computing unit stores in the memory a predetermined relationship established between the state quantity to be measured and the information related to the output signal of the pair of revolution speed detection sensors. Having a function of calculating the state quantity based on the information using a predetermined relationship;
A method for replacing a sensor of a rolling bearing unit with a state quantity measuring device according to claim 1.   Replacing the sensor of the rolling bearing unit with a state quantity measuring device according to any one of claims 1 to 3, wherein a predetermined relationship is reexamined while rotating the rotating side raceway with respect to the stationary side raceway. Method.   The rolling bearing unit is a hub unit for supporting a wheel of an automobile, the stationary-side bearing ring is supported by a suspension device of the automobile in use, and the wheel is coupled and fixed to a hub that is a rotating-side bearing ring. 4. A method for replacing a sensor of a rolling bearing unit with a state quantity measuring device according to any one of 4.

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