JP5459059B2 - Rolling bearing unit for wheel support with physical quantity measuring device - Google Patents

Description

  The present invention measures a wheel bearing rolling bearing unit for rotatably supporting a wheel of a vehicle such as an automobile with respect to a suspension device, a load acting on the wheel, and a physical quantity such as a rotation speed of the wheel. The present invention relates to an improvement of a rolling bearing unit for supporting a wheel with a physical quantity measuring device, which is combined with a physical quantity measuring device for performing the above.

  In order to make the control of the stability control device to ensure the running stability of the car more sophisticated, a load measuring device, which is a kind of physical quantity measuring device, is incorporated in the rolling bearing unit for wheel support of the car, It is considered to measure the axial load and radial load applied to each wheel. 5-6 has shown what was described in patent document 1 as an example of the conventional structure of such a rolling bearing unit with a load measuring device. One example of this conventional structure includes a wheel-supporting rolling bearing unit 1, an encoder 2, a pair of sensors 3a and 3b, each of which constitutes a load measuring device, and a calculator (not shown).

  As shown in FIG. 5, the wheel bearing rolling bearing unit 1 includes an outer ring 4 that is a stationary side race ring, a hub 5 that is a rotary side race ring, and a plurality of balls 6 each of which is a rolling element. , 6. Outer ring 4 has double-row outer ring raceways 7a and 7b on the inner peripheral surface and stationary flange 8 on the outer peripheral surface. The hub 5 is disposed concentrically with the outer ring 4 on the inner diameter side of the outer ring 4, and a double row of inner ring raceways 9a is arranged on the outer peripheral surface of the hub 5 opposite to the outer ring raceways 7a and 7b. 9b from the inner diameter side of the outer ring 4 to the outside in the axial direction ("outside" with respect to the axial direction means the outside in the width direction of the vehicle when assembled to the automobile, and the left side in FIGS. 1, 5, 8, which is the central side in the width direction of the vehicle, is referred to as “inside” with respect to the axial direction, and is the same as the entirety of the present specification and claims. Each has a rotation side flange 10. Further, a plurality of balls 6, 6 are provided between the outer ring raceways 7a, 7b and the inner ring raceways 9a, 9b so as to roll freely for each row. A preload is applied to these rows of balls 6 and 6 together with the contact angle of the rear combination type. When such a wheel-supporting rolling bearing unit 1 is used, the stationary-side flange 8 of the outer ring 4 is coupled and fixed to a vehicle body-side support member such as a knuckle that constitutes a suspension device of an automobile, and the rotation side of the hub 5 is also fixed. A wheel is supported and fixed to the flange 10. Thereby, this wheel is rotatably supported with respect to the said suspension apparatus.

  The encoder 2 includes a cylindrical metal core 11 made of a magnetic metal plate, and a permanent magnet cylindrical encoder body 12 fixedly attached to the outer peripheral surface of the metal core 11 over the entire circumference. . On the outer peripheral surface of the encoder main body 12, which is a detected surface, S poles and N poles are alternately arranged at equal intervals in the circumferential direction. The boundary between the S pole and the N pole has a “V” shape in which a bent portion is arranged at the center in the width direction of the detected surface. Moreover, the width direction both half parts which pinched | interposed this "V" -shaped bending part are made into the 1st characteristic change part 13 and the 2nd characteristic change part 14 among this to-be-detected surface. Such an encoder 2 is externally fitted and fixed concentrically to the hub 5 at a portion sandwiched between the inner ring raceways 9a and 9b at the axially intermediate portion of the hub 5.

  The pair of sensors 3a and 3b incorporate magnetic sensing elements such as a Hall IC, a Hall element, an MR element, and a GMR element as detection parts at their respective distal ends. On the other hand, a pair of support holes 15 and 15 are formed in a portion between the outer ring raceways 7a and 7b at an intermediate portion in the axial direction of the outer ring 4. The two sensors 3a and 3b are configured such that the detection part of one sensor 3a faces the first characteristic change part 13 and the detection part of the other sensor 3b faces the second characteristic change part 14, respectively. It is supported and fixed inside the support holes 15 and 15.

  In the case of an example of the conventional structure configured as described above, when an axial load acts between the outer ring 4 and the hub 5, when the outer ring 4 and the hub 5 are relatively displaced in the axial direction, The scanning positions of the detection units of the sensors 3a and 3b with respect to the first and second characteristic change units 13 and 14 are shifted in the axial direction. As a result, the phase difference ratio (= phase difference / 1 period) between the output signals of these sensors 3a and 3b changes. In this case, this phase difference ratio takes a value commensurate with the axial load (relative displacement in the axial direction). Therefore, the axial load (relative displacement in the axial direction) can be calculated based on this phase difference ratio. This calculation process is performed by the calculator. For this reason, in this computing unit, the relationship between the phase difference ratio and the axial load (relative displacement in the axial direction), which has been studied in advance by theoretical calculation or experiment, is incorporated in a calculation formula or a model such as a map. deep.

  In the case of one example of the conventional structure described above, the frequency (cycle) of the output signals of both sensors 3a and 3b changes according to the rotational speed of the wheel. For this reason, it is considered that the output signals of both the sensors 3a and 3b can be used for the control of the ABS or the like as a signal representing the rotational speed of the wheel. However, in this case, in order to control the ABS or the like at a level comparable to the conventional level, the pulse waveforms of the output signals of the sensors 3a and 3b are used as physical quantities that have been conventionally used for the control of the ABS and the like. It is necessary to approach the same specification as the pulse waveform of the output signal of the sensor that constitutes the rotational speed detection device, which is a kind of measurement device. Specifically, at least the following two conditions must be satisfied.

First, the first condition is that the number of characteristic changes per revolution of the detected surface of the encoder 2 is approximately the same as the number of characteristic changes per revolution of the detected surface of the encoder constituting the rotational speed detection device. It is a condition to say that it is more. This first condition can be easily satisfied by determining the configuration of the encoder 2 as such.
Next, the second condition is that the density of the magnetic flux passing through the detection units of both the sensors 3a and 3b is as high as the density of the magnetic flux passing through the detection unit of the sensor constituting the rotational speed detection device. It is a condition to say. A method that satisfies the second condition will be described below.

  FIG. 7 shows a surface to be detected of a radially opposed encoder 16 constituting a rotational speed detection device that has been conventionally used for control of ABS and the like. As for the encoder, the radial facing type means a type in which its peripheral surface is a surface to be detected, and the detection portion of the sensor faces the surface to be detected in the radial direction (radial direction). Therefore, the encoder 2 shown in FIGS. 5 to 6 is also of a radial facing type. On the other hand, a type in which its side surface is a detection surface and the detection part of the sensor is opposed to the detection surface in the axial direction (axial direction) is referred to as an axial opposed type.

In the case of the encoder 16 that constitutes the rotational speed detection device shown in FIG. 7, unlike the encoder 2 that constitutes the load measuring device shown in FIG. It is not inclined with respect to the width direction of the surface, and is parallel to the width direction of the detected surface. When the diameters of the surfaces to be detected of both the encoders 16 and 2 are equal to each other and the first condition is satisfied, that is, when the number of characteristic changes per round of the both surfaces to be detected is equal to each other. The pitch width P in the circumferential direction of the characteristic boundary that is the boundary between the S pole and the N pole existing on both of the detected surfaces is also equal to each other. However, the pitch width that contributes to the density of magnetic flux generated around both of the detected surfaces is a pitch width that represents the degree of geometric proximity between the S pole and the N pole. That is, in the case of the encoder 16 shown in FIG. 7, the pitch width P in the circumferential direction becomes the pitch width that contributes to the magnetic flux density as it is. On the other hand, in the case of the encoder 2 shown in FIG. 6, since the shape of the characteristic boundary is a “V” shape with an opening of 90 degrees, the pitch width P _{d of} 45 degrees obliquely contributes to the magnetic flux density. It becomes the pitch width. Pitch P _d of this oblique 45 °, 1 / √2 times the circumferential direction of the pitch width P (about 0.7 times) shorter. For this reason, in the case of the encoder 2 shown in FIG. 6, the magnetic flux density at the position where the distance from the detection surface is equal is lower than in the case of the encoder 16 shown in FIG.

  In such a case, the second condition, that is, the density of the magnetic flux passing through the detection units of the pair of sensors 3a and 3b constituting the load measuring device is determined by the sensor constituting the rotational speed detecting device. In order to satisfy the condition that it is as high as the density of the magnetic flux passing through the detection unit, an air gap, which is a distance between the detection surface of the encoder 2 and the detection units of the sensors 3a and 3b, It is necessary to make it smaller than the air gap between the detected surface of the encoder 16 and the detection part of the sensor. This is because the density of the magnetic flux generated around the detection surfaces of the encoders 16 and 2 decreases as the distance from the detection surfaces increases, and increases as the distance from the detection surfaces increases.

Further, when the second condition is satisfied by such a method, a structure in which both the sensors 3a and 3b are directly supported and fixed to the outer ring 4 as in the example of the conventional structure shown in FIG. If this is adopted, the assembly error can be reduced as compared with the case where both the sensors 3a, 3b are supported and fixed to the outer ring 4 via a support member, and the case where these sensors 3a, 3b are supported and fixed to a part of the vehicle body. As much as possible, the air gap can be set with high accuracy. For this reason, it becomes easy to make this air gap small as desired.
However, even if the air gap is made small, the density of the magnetic flux passing through the detection parts of the sensors 3a and 3b may not be increased to a desired height. Therefore, it cannot be said that the method of reducing the air gap is a reliable countermeasure.

  In consideration of the above points, when performing control of ABS or the like, the rotation speed detection device is not used as the signal indicating the rotation speed of the wheel, but the output signal of the sensor constituting the load measuring device is used as usual. It can be said that using the output signal of the constituent sensor is the most reliable method that does not reduce the reliability related to the control.

[Description of Prior Invention]
8 to 10 show the structure of the prior invention relating to a wheel bearing rolling bearing unit with a physical quantity measuring device, which has not been disclosed, but was developed in view of the above-described circumstances and disclosed in Japanese Patent Application No. 2009-215463. ing. The structure of this prior invention is characterized in that a first encoder 2a and a pair of first sensors for measuring an axial load acting between the outer ring 4a and the hub 5a with respect to the wheel support rolling bearing unit 1a. 3c and 3d are provided with a second encoder 16a and a second sensor 17 for detecting the rotational speed of the hub 5a, and the encoders 2a and 16a and the first sensors 3c and 3d. , 17 installation points, installation methods and the like. Except for the point that the wheel bearing rolling bearing unit 1a is changed from the type supporting the driven wheel to the type supporting the driving wheel, other configurations and operations are shown in FIGS. This is almost the same as the conventional structure.

The first encoder 2a is supported and fixed to the inner end in the axial direction of the hub 5a. The first encoder 2a includes an annular cored bar 11a made of a magnetic metal plate and a cylindrical first encoder body 12a made of a permanent magnet. The core metal 11a includes a small-diameter cylindrical portion 18, an annular portion 19 that is bent radially outward from an axial inner end edge of the small-diameter cylindrical portion 18, and an axial direction from the outer peripheral edge of the annular portion 19. The large-diameter cylindrical portion 20 is bent inward at a right angle. The first encoder body 12a is fixedly attached to the outer peripheral surface of the large-diameter cylindrical portion 20 over the entire periphery. As shown in FIG. 9, on the outer peripheral surface of the first encoder body 12a, which is the first detected surface, there are S and N poles as in the case of the encoder 2 shown in FIGS. These are arranged alternately and at equal intervals in the circumferential direction. At the same time, the shape of the boundary between the S pole and the N pole is a “V” shape. In the first detected surface, the half halves in the width direction sandwiching the bent portion of the “V” shape are used as the first characteristic changing unit 13 and the second characteristic changing unit 14. Such a first encoder 2a is configured such that the outer half in the axial direction of the small-diameter cylindrical portion 18 constituting the core metal 11a is externally fitted to the inner end in the axial direction of the hub 5a by an interference fit. On the other hand, it is supported and fixed concentrically with the hub 5a. In the case of the illustrated structure, the outer diameter D _2a of the first detection target surface of the first encoder 2a has an inner diameter dimension D of the circular support hole 22 formed in a part of the vehicle body-side support member 21 to be described later Closer to ₂₂ and larger.

  Each of the pair of first sensors 3c and 3d includes a magnetic sensing element such as a Hall IC, a Hall element, an MR element, and a GMR element as a detection unit, and a first sensor holder 23 made of synthetic resin. Embedded in the tip (upper end in FIG. 8). In an assembled state to the vehicle body, which will be described later, the first sensor holder 23 is configured such that the detection part of one of the first sensors 3c and 3d is used as the first characteristic changing part 13 and the other sensor. The 3d detection unit is supported and fixed to a part of a vehicle body (not shown) in a state where the detection unit 3d is opposed to the second characteristic change unit 14 in the radial direction.

  The second encoder 16a is supported and fixed at a portion near the inner end in the axial direction of the outer peripheral surface of the hub 5a between the inner ring raceway 9b and the first encoder 2a in the axial direction. The second encoder 16a is fixedly attached to the entire circumference of a cored bar 24 that is L-shaped in cross section with a magnetic metal plate and is configured to be annular as a whole. The second encoder body 25 is made of a permanent magnet and has a ring shape. As shown in FIG. 10, S poles and N poles are alternately arranged at equal intervals in the circumferential direction on the inner surface in the axial direction of the second encoder body 25 which is the second detected surface. Yes. The shape of the boundary between the S pole and the N pole is a straight line parallel to the width direction (radial direction) of the second detected surface. Such a second encoder 16a is supported and fixed to the hub 5a concentrically with the hub 5a by fitting the core metal 24 to the axially inner end portion of the hub 5a with an interference fit. Yes.

  The second sensor 17 includes a magnetic sensing element such as a Hall IC, a Hall element, an MR element, and a GMR element as a detection unit, and the tip of the second sensor holder 26 made of synthetic resin (FIG. 8). Embedded in the lower end). The second sensor holder 26 is not shown in a state in which the detection part of the second sensor 17 is closely opposed to the second detection part of the second encoder 16a in the axial direction in an assembled state to the vehicle body described later. Supported and fixed to a part of the vehicle body.

  In the case of the structure of the prior invention as described above, when the wheel bearing rolling bearing unit 1a is assembled to the vehicle body, as shown in FIG. 8, the axially inner end of the outer ring 4a constitutes a suspension device. It is inserted inside a circular support hole 22 formed in the vehicle body side support member 21 such as a knuckle. As a result, the inner surface of the stationary flange 8 provided on the outer peripheral surface of the outer ring 4 a is brought into contact with the outer surface of the vehicle body side support member 21. In this state, the stationary flange 8 is coupled and fixed to the vehicle body support member 21 with a plurality of bolts (not shown). In addition, a spline shaft 29 fixed to the central portion of the outer end surface in the axial direction of the outer ring 28 for the constant velocity joint is connected to the spline hole 27 formed in the axial center portion of the hub 5a in the axial direction. Insert from. As a result, the spline shaft 29 is spline-engaged with the spline hole 27, and the outer peripheral edge portion of the axial outer end face of the constant velocity joint outer ring 28 is brought into contact with the axial inner end face of the hub 5a. In this state, the hub 5a and the constant velocity joint outer ring 28 are coupled and fixed so as to be able to transmit a rotational force by screwing and tightening a holding bolt 30 to the tip of the spline shaft 29. To do. The first and second sensor holders 23 and 26 are supported and fixed to a part of a vehicle body (not shown) in the state described above. Further, a wheel (not shown) is supported and fixed to the rotation side flange 10 provided on the outer peripheral surface of the hub 5a near the outer end in the axial direction.

  In the case of the structure of the prior invention as described above, it is used to measure the relative displacement in the axial direction between the outer ring 4a and the hub 5a and the axial load acting between the outer ring 4a and the hub 5a. In addition to the first encoder 2a and the pair of first sensors 3c and 3d, a second encoder 16a and a second sensor 17 are provided which are used to measure the rotational speed of the hub 5a. The second encoder 16a and the second sensor 17 have the same configuration as the encoder and sensor that constitute the rotational speed detection device that has been conventionally used for controlling ABS and the like. For this reason, in the case of this example, the output signal of the second encoder 16a can be suitably used for control of ABS or the like as a signal representing the rotational speed of the wheel.

  Further, in the case of the structure of the above-described prior invention, it is not necessary to use the output signals of the first sensors 3c and 3d as signals representing the rotational speed of the wheels for the control of ABS or the like. Therefore, in order to increase the density of the magnetic flux passing through the detection parts of the first sensors 3c and 3d, the air between the detection parts of the first sensors 3c and 3d and the first detected surface of the first encoder 2a. There is no need to take measures such as making the gap smaller than the normal setting. For this reason, in the case of the structure of the prior invention described above, the structure in which the measure is easily taken, that is, the first sensor holder 23 holding the first sensors 3c and 3d is directly supported and fixed to the outer ring 4a. There is no need to adopt a structure. Under such circumstances, the structure of the above-described prior invention employs a structure in which the first sensor holder 23 is supported and fixed to a part of the vehicle body. Further, the second sensor holder 26 that holds the second sensor 17 is not directly supported and fixed to the outer ring 4a but is supported and fixed to a part of the vehicle body.

  When the structure in which the first and second sensor holders 23 and 26 are directly supported and fixed to the outer ring 4a is adopted, the first and second sensor holders 23 and 26 are supported as the outer ring 4a. It is necessary to use the one formed with the support holes. That is, a general-purpose one cannot be used as the outer ring 4a. On the other hand, in the case of the structure of the prior invention described above, a structure is employed in which the first and second sensor holders 23 and 26 are supported and fixed to a part of the vehicle body. For this reason, a general-purpose outer ring 4a can be used. Therefore, the product cost can be reduced accordingly.

Further, in the case of the structure of the above-described invention, the first sensor holder 23 can be installed after the wheel-supporting rolling bearing unit 1a is assembled to the vehicle body-side support member 21. Therefore, without considering the presence of the first sensor holder 23, a first outer diameter D _2a of the detection surface of the first encoder 2a, a support hole formed in a portion of the vehicle body-side support member 21 The inner diameter dimension D22 of ₂₂ is made close and larger. When the number of characteristic changes per round of the first detected surface is constant, the characteristics of the output signals of the first sensors 3c and 3d increase as the outer diameter of the first detected surface increases. Become good. Therefore, in the case of the structure of the prior invention described above, by the amount of increasing the outer diameter D _2a of the first detection target surface as described above, good characteristics of both the first sensor 3c, 3d the output signal of the I can do it.

  In the case of the structure of the prior invention described above, the portion of the first encoder 2a other than the outer half portion in the axial direction of the small-diameter cylindrical portion 18 is more axial than the inner end portion in the axial direction of the hub 5a. It is arranged in a state protruding inward in the direction. However, the inner diameter dimension of the large-diameter cylindrical portion 20 is large enough to avoid interference with the convex outer peripheral surface of the constant velocity joint outer ring 28. For this reason, in order to avoid the interference, it is not necessary to retract the position of the convex outer peripheral surface of the constant velocity joint outer ring 28 inward in the axial direction. Therefore, it is not necessary to redesign the vehicle body side drive system.

  However, in the case of the structure of the above-described invention, the first and second encoders 2a and 16a are installed at positions close to each other. For this reason, magnetic interference occurs between the first detected surface of the first encoder 2a and the second detected surface of the second encoder 16a, and the first and second sensors 3c, There is a possibility that the pitch accuracy of the output signals of 3d and 17 deteriorates. However, both the first sensors 3c and 3d are considered to have a small influence of magnetic interference based on the presence of the second detected surface because the distance from the second detected surface is somewhat apart. . On the other hand, since the second sensor 17 has a short distance from the first detected surface, the influence of magnetic interference based on the presence of the first detected surface is large and may cause a detection error during use. There is. Therefore, it is desirable to realize a structure capable of reducing or eliminating the influence of the magnetic interference at least with respect to the second sensor 17. In addition, if the installation interval between the first and second encoders 2a and 16a is sufficiently widened, such a demand can be met, but a limited space in the axially inner end of the wheel support rolling bearing unit 1a. It is difficult to realize such a structure within.

JP 2006-317420 A JP 2006-322928 A JP 2008-64731 A

  The rolling bearing unit for supporting a wheel with a physical quantity measuring device of the present invention, in view of the circumstances as described above, separately from the first encoder and the first sensor for measuring the load acting between both races, A second encoder and a second sensor for detecting the rotational speed of the wheel are provided, and when the second sensor and the first encoder are arranged at positions close to each other, the presence of the first encoder The present invention was invented to realize a structure capable of suppressing or eliminating the influence of magnetic interference exerted on the second sensor.

A wheel support rolling bearing unit with a physical quantity measuring device of the present invention includes a wheel support rolling bearing unit, a first encoder, a first sensor, a second encoder, and a second sensor.
Of these, the rolling bearing unit for supporting the wheel includes a stationary side bearing ring that does not rotate while being coupled and fixed to a suspension device in use, and a rotating side bearing ring that rotates together with the wheel while supporting and fixing the wheel during use. , And are combined in a relatively rotatable manner via a plurality of rolling elements.
The first encoder is supported and fixed to the rotation-side raceway and has a first detection surface concentric with the rotation-side raceway. The first detection surface includes an S pole and an N pole. Are alternately arranged in the circumferential direction, and the boundary between the S pole and the N pole adjacent in the circumferential direction is inclined with respect to the width direction of the first detected surface.
In addition, the first sensor changes its output signal in response to a change in magnetic flux passing through its own detection unit, and when used, its own detection unit is made to face the first detection surface. In this state, it is supported and fixed to the stationary side race ring or a member that is not displaced relative to the stationary side race ring.
Further, the second encoder is supported and fixed to a portion of the rotation side raceway that is disengaged from the first encoder, and has a second detected surface concentric with the rotation side raceway. S poles and N poles are alternately arranged in the circumferential direction on the two detected surfaces, and the boundary between the S pole and the N pole adjacent in the circumferential direction is made parallel to the width direction of the second detected surface. Yes.
The second sensor changes its output signal in response to a change in magnetic flux passing through its own detection unit, and when used, its own detection unit is made to face the second detection surface. In the state, it is supported and fixed to the stationary side race ring or a member that is not displaced with respect to the stationary side race ring.
The output signal of the first sensor is used to measure at least one of a relative displacement between the two races and an external force acting between the races.
The output signal of the second sensor is used to detect the rotational speed of the rotating side race.
In addition, the distance between the detection unit of the second sensor and the first detected surface during use is greater than the distance between the detection unit of the first sensor and the second detected surface during use. short.
In particular, the wheel support rolling bearing unit with a physical quantity measuring device of the present invention includes a magnetic shield member made of a magnetic material. And any one of the positions surrounding the second sensor, excluding the position sandwiched between the detection portion of the second sensor and the second detected surface, and the magnetic shield The magnetic shield member is provided at a position where the member can suppress or eliminate the influence of the magnetic interference based on the presence of the first detected surface from reaching the second sensor.

In carrying out the present invention, for example, the configuration of the invention described in claim 2 can be adopted.
When the configuration of the invention described in claim 2 is adopted, the stationary-side bearing ring constituting the wheel-supporting rolling bearing unit is an outer ring having double-row outer ring raceways on the inner peripheral surface. Similarly, the rotation side raceway is arranged concentrically with the outer race on the inner diameter side of the outer race, and a double row of inner raceways are arranged on the outer peripheral surface of the outer race in a portion facing both outer raceways. Each hub has a rotation-side flange for supporting and fixing a wheel to a portion protruding axially outward from the inner diameter side. Similarly, a plurality of the rolling elements are provided between the outer ring raceways and the inner ring raceways so as to be freely rollable in both rows.
In addition, the first encoder is supported and fixed to the inner side in the axial direction of the outer peripheral surface of the hub with respect to the inner ring raceways, and the first detected surface is provided on the outer peripheral surface.
In addition, when the first sensor is used, its own detection unit is opposed to the first detected surface in the radial direction.
The second encoder is supported and fixed to a portion of the outer peripheral surface of the hub between the inner ring raceways and the first encoder with respect to the axial direction, and the second detected surface is the inner surface in the axial direction. It shall have in.
In addition, when the second sensor is used, its own detection unit is made to face the second detection surface in the axial direction.

In carrying out the present invention, preferably, the second sensor is embedded in a sensor holder made of synthetic resin, as in the invention described in claim 3. At the same time, the magnetic shield member is coupled and fixed to the sensor holder in a state where the magnetic shield member is disposed at a position sandwiched between the detection portion of the second sensor and the detection surface of the first encoder.
In carrying out the invention described in claim 3, preferably, the magnetic shield member is embedded inside the second sensor as in the invention described in claim 4. A sensor case having an opening at a position sandwiched between the detection portion of the second sensor and the second detected surface of the second encoder in a state where the sensor holder is housed.
In carrying out the inventions described in the third to fourth aspects, preferably, as in the invention described in the fifth aspect, the magnetic shield member is moved along with the injection molding of the sensor holder. Connect and fix to the sensor holder.

  In the case of the rolling bearing unit for supporting a wheel with a physical quantity measuring device of the present invention having the above-described configuration, the first encoder and the first sensor for measuring the load acting between the two race rings are Separately, a second encoder and a second sensor for detecting the rotational speed of the wheel are provided, and the detection part of the second sensor and the first detected surface of the first encoder are arranged close to each other. Although it is a structure, the magnetic shield member can suppress or eliminate the influence of magnetic interference exerted on the second sensor based on the presence of the first encoder. That is, since a magnetic path is formed between the first detected surface of the first encoder and the magnetic shield member, leakage magnetic flux from the first detected surface to the detecting portion of the second sensor is reduced. . Therefore, the magnetic shield member can suppress or eliminate the influence of magnetic interference exerted on the second sensor based on the presence of the first encoder. As a result, it is possible to ensure the pitch accuracy of the output signal of the second sensor at a level with no practical problem.

If the configuration of the invention described in claim 3 is adopted, the detection part of the second sensor and the detection surface of the first encoder are separated by the magnetic shield member. For this reason, the influence of magnetic interference exerted on the second sensor based on the presence of the first encoder can be effectively suppressed or eliminated by the magnetic shield member.
In addition, if the configuration of the invention described in claim 4 is adopted, most of the periphery of the second sensor excluding the side facing the second detection surface of the second encoder is the magnetic shield member. It will be in the state surrounded by the sensor case which is. For this reason, the influence of the magnetic interference exerted on the second sensor based on the presence of the first encoder can be more effectively suppressed or eliminated by the magnetic shield member.
If the configuration of the invention described in claim 5 is adopted, the magnetic shield member can be easily and efficiently fixed and fixed to the sensor holder.

The enlarged view equivalent to the X section of FIG. 8 which shows the 1st example of embodiment of this invention. The figure similar to FIG. 1 which shows the 2nd example. The figure similar to FIG. 1 which shows the 3rd example. The perspective view of the sensor case which is a 2nd sensor incorporated in this 3rd example, a 2nd sensor holder, and a magnetic shielding member. Sectional drawing which shows an example of a conventional structure. The figure which looked at a part of the to-be-detected surface of an encoder from the outer-diameter side. The figure which looked at a part of to-be-detected surface of the encoder which comprises a rotational speed detection apparatus from the outer-diameter side. Sectional drawing shown in the state assembled | attached to the vehicle body. The figure which looked at the 1st encoder from the diameter direction. The figure which looked at a part of 2nd to-be-detected surface of the 2nd encoder from the axial direction.

[First example of embodiment]
FIG. 1 shows a first example of an embodiment of the present invention corresponding to claims 1 to 5. The feature of this example is that the magnetic shield member 31 is coupled and fixed to the second sensor holder 26a made of synthetic resin in which the second sensor 17 is embedded. The structure and operation of other parts are the same as those of the structure of the prior invention shown in FIGS. For this reason, overlapping illustrations and descriptions will be omitted or simplified, and the following description will focus on the features of this example.

  In the case of this example, the second sensor holder 26a embedding the second sensor 17 includes an insertion portion 32 and a flange portion formed integrally with the proximal end portion (upper end portion in FIG. 1) of the insertion portion 32. 33. And the front-end | tip part (lower end part in FIG. 1) of the insertion part 32 is inserted in the inner diameter side of this vehicle body side support member 21a through the insertion hole 34 formed in a part of the vehicle body side support member 21a. doing. At the same time, the flange portion 33 is screwed and fixed to the vehicle body side support member 21a. The second sensor 17 has a side surface (in FIG. 1) that faces the second detected surface of the second encoder 16a in the distal end portion (lower end portion in FIG. 1) of the insertion portion 32. Embedded in the surface layer of the left side).

  The magnetic shield member 31 is formed in a rectangular plate shape using a magnetic plate material such as a steel plate or a magnetic alloy such as Permalloy (trade name). In the case of this example, such a magnetic shield member 31 is provided on the side surface (the right side surface in FIG. 1) of the insertion portion 32 opposite to the second detected surface of the second encoder 16a. Bonded and fixed. Thereby, the detection part of said 2nd sensor 17 and the 1st to-be-detected surface which is the outer peripheral surface of the 1st encoder 2a are made into the state separated by the said magnetic shield member 31. FIG. The operation of coupling and fixing the magnetic shield member 31 to the second sensor holder 26a can be performed along with the injection molding of the second sensor holder 26a, or the operation of the second sensor holder 26a can be performed. It can also be performed by adhesion after injection molding.

  In the case of the wheel bearing rolling bearing unit with a physical quantity measuring device of this example configured as described above, the first encoder 2a and the first encoder for measuring the axial load acting between the outer ring 4a and the hub 5a. In addition to the sensors 3c and 3d (see FIG. 8), a second encoder 16a and a second sensor 17 for detecting the rotational speed of the wheel are provided. The magnetic shield member 31 causes the magnetic shield member 31 to influence the magnetic interference exerted on the second sensor 17 based on the presence of the first encoder 2a. Can be suppressed or eliminated. That is, in the case of this example, the detection part of the second sensor 17 and the first detected surface of the first encoder 2 a are separated by the magnetic shield member 31. For this reason, a magnetic path is formed between the first detected surface and the magnetic shield member 31, and the leakage magnetic flux from the first detected surface to the detecting portion of the second sensor 17 can be reduced. Therefore, the magnetic shield member 31 can suppress or eliminate the influence of magnetic interference exerted on the second sensor 17 based on the presence of the first encoder 2a. As a result, it is possible to maintain the pitch accuracy of the output signal of the second sensor 17 at a level that causes no problem in practice.

[Second Example of Embodiment]
FIG. 2 shows a second example of an embodiment of the present invention corresponding to claims 1 to 5. In the case of this example, the magnetic shield member 31 is embedded in the intermediate portion in the width direction (left-right direction in FIG. 2) of the insertion portion 32 of the second sensor holder 26a. That is, in the case of this example, a structure is adopted in which the magnetic shield member 31 is integrally coupled and fixed to the second sensor holder 26a as the second sensor holder 26a is injection molded. Other configurations and operations are the same as those of the first example described above.

[Third example of embodiment]
FIGS. 3-4 has shown the 3rd example of embodiment of this invention corresponding to Claims 1-5. In the case of this example, the magnetic shield member 31a that is coupled and fixed to the second sensor holder 26b is used as a sensor case that houses the insertion portion 32a of the second sensor holder 26b. Such a magnetic shield member 31a includes a bottomed cylindrical storage portion 36 having an opening 35 in a portion facing the second detection surface of the second encoder 16a, and a base end portion of the storage portion 36 (FIG. 3). And a flange portion 37 fixed to the upper end portion in 4. The magnetic shield member 31a is coupled and fixed to the second sensor holder 26b in a state where the insertion portion 32a of the second sensor holder 26b is housed inside the housing portion 36. At the same time, the flange portion 37 is screwed and fixed to the vehicle body side support member 21a. In this state, in order to prevent a magnetic path from being formed between the magnetic shield member 31a and the second sensor 17 embedded in the sensor holder 26b, the magnetic shield member 31a and the second sensor 17 are prevented. To avoid contact. Also in this example, the operation of coupling and fixing the magnetic shield member 31a to the second sensor holder 26b can be performed along with the injection molding of the second sensor holder 26b. It can also carry out by adhesion after the injection molding of the second sensor holder 26b. In the case of this example, the detection portion of the second sensor 17 embedded in the second sensor holder 26b is opposed to the second detected surface of the second encoder 16a through the opening 35 of the magnetic shield member 31a. ing.

  In the case of this example configured as described above, the second sensor 17 is surrounded by the magnetic shield member 31a over a wide range. For this reason, the leakage magnetic flux from the 1st to-be-detected surface of the 1st encoder 2a to the detection part of the said 2nd sensor 17 can be reduced more. Therefore, the magnetic shield member 31a can more effectively suppress or eliminate the influence of magnetic interference exerted on the second sensor 17 based on the presence of the first encoder 2a.

In each of the above-described embodiments, the relative displacement between the stationary and rotating side raceways constituting the wheel support rolling bearing unit and the external force acting between these raceways are included. As a combination of the first encoder and the first sensor used for measuring at least one of them, a combination of an encoder having a “V” -shaped characteristic boundary on the detection surface and a pair of sensors was adopted. However, when the present invention is implemented, other types of combinations described in Patent Documents 1 to 3 and the like that have been conventionally known can be adopted as the combination.
When the present invention is implemented, the second encoder is not limited to the axially opposed type, but may be a radially opposed type.
Moreover, when implementing this invention, the aspect regarding the shape and installation position of a magnetic shield member can employ | adopt various aspects, as long as the objective of this invention can be achieved.
Furthermore, when practicing the present invention, the magnetic force for suppressing or eliminating the influence of magnetic interference on the first sensor is separated from the magnetic shield member for suppressing or eliminating the influence of magnetic interference on the second sensor. A shield member may be provided. That is, in this case, the position surrounding the periphery of the first sensor is any position excluding the position sandwiched between the detection unit of the first sensor and the first detection surface. The magnetic shield member is provided at a position where the magnetic shield member can suppress or eliminate the influence of magnetic interference based on the presence of the second detected surface from reaching the first sensor.

In the present invention, the distance between the detection part of the second sensor and the first detection surface during use is greater than the distance between the detection part of the first sensor and the second detection surface during use. For a short structure, a structure in which a magnetic shield member is provided at a position where at least the influence of magnetic interference on the second sensor can be suppressed or eliminated was adopted.
On the other hand, the structure in which the distance between the detection unit of the first sensor and the second detection surface during use is shorter than the distance between the detection unit of the second sensor and the first detection surface during use. When a target is used, a structure in which a magnetic shield member is provided at a position where at least the influence of magnetic interference on the first sensor can be suppressed or eliminated can be employed.

DESCRIPTION OF SYMBOLS 1, 1a Rolling bearing unit for wheel support 2 Encoder 2a 1st encoder 3a, 3b Sensor 3c, 3d 1st sensor 4, 4a Outer ring 5, 5a Hub 6 Ball 7a, 7b Outer ring track 8 Stationary side flange 9a, 9b Inner ring track 10 Rotation side flange 11, 11a Core metal 12 Encoder body 12a First encoder body 13 First characteristic changing part 14 Second characteristic changing part 15 Support hole 16 Encoder 16a Second encoder 17 Second sensor 18 Small diameter cylindrical part 19 Circular ring part 20 Large diameter cylindrical portion 21, 21a Car body side support member 22 Support hole 23 First sensor holder 24 Core metal 25 Second encoder body 26, 26a, 26b Second sensor holder 27 Spline hole 28 Outer ring for constant velocity joint 29 Spline shaft 30 Suppression Bolt 31, 31a Magnetic shield member 32, 32 a Insertion part 33 Flange part 34 Insertion hole 35 Opening part 36 Storage part 37 Flange part

Claims (5)

A wheel bearing rolling bearing unit, a first encoder, a first sensor, a second encoder, and a second sensor;
Of these, the rolling bearing unit for supporting a wheel includes a stationary side bearing ring that does not rotate while being coupled and fixed to a suspension device in use, and a rotating side bearing ring that rotates together with the wheel while supporting and fixing the wheel during use. , Which are combined in a relatively rotatable manner via a plurality of rolling elements,
The first encoder is supported and fixed to the rotation-side raceway and has a first detected surface concentric with the rotation-side raceway. While alternately arranged in the circumferential direction, the boundary between the S pole and the N pole adjacent in the circumferential direction is inclined with respect to the width direction of the first detected surface,
The first sensor changes its output signal in response to a change in the magnetic flux passing through its own detection unit, and is used in a state where its detection unit is opposed to the first detection surface during use. It is supported and fixed to a stationary side race ring or a member that is not displaced with respect to the stationary side race ring,
The second encoder is supported and fixed to a portion of the rotation side raceway that is separated from the first encoder, and has a second detection surface concentric with the rotation side raceway. S poles and N poles are alternately arranged on the detection surface in the circumferential direction, and the boundary between the S pole and N pole adjacent in the circumferential direction is parallel to the width direction of the second detection surface. Yes,
The second sensor changes its output signal in response to a change in magnetic flux passing through its own detection unit, and when used, the detection unit faces the second detection surface in a state where the detection unit faces the second detection surface. It is supported and fixed to a stationary side race ring or a member that is not displaced with respect to the stationary side race ring,
The output signal of the first sensor is used to measure at least one of a relative displacement between the two races and an external force acting between the races. ,
The output signal of the second sensor is used to detect the rotational speed of the rotating side race ring,
The distance between the detection unit of the second sensor and the first detection surface during use is shorter than the distance between the detection unit of the first sensor and the second detection surface during use,
A rolling bearing unit for supporting wheels with a physical quantity measuring device,
A magnetic shield member made of a magnetic material is provided, and the position surrounding the periphery of the second sensor, excluding the position sandwiched between the detection portion of the second sensor and the second detection surface, The magnetic shield member is provided at a position where the magnetic shield member can suppress or eliminate the influence of the magnetic interference based on the presence of the first detected surface from reaching the second sensor. A rolling bearing unit for supporting wheels with a physical quantity measuring device. The stationary bearing ring constituting the wheel support rolling bearing unit is an outer ring having a double row outer ring raceway on the inner peripheral surface, and the rotating side race ring is concentric with the outer ring on the inner diameter side of the outer ring. Rotation for supporting and fixing a double row of inner ring raceways in a portion of the outer peripheral surface facing the both outer ring raceways, and a wheel in a portion protruding axially outward from the inner diameter side of the outer ring. Each of the rolling elements is a hub having side flanges, and each of the rolling elements is provided between the outer ring raceways and the inner ring raceways so as to be capable of rolling plurally in both rows.
The first encoder is supported and fixed to the inner side in the axial direction from the inner ring raceway among the outer peripheral surfaces of the hub, and has a first detected surface on the outer peripheral surface,
The first sensor, when in use, has its detection unit opposed to the first detection surface in the radial direction,
The second encoder is supported and fixed at a portion between the inner ring raceways and the first encoder in the axial direction on the outer peripheral surface of the hub, and has a second detected surface on the inner surface in the axial direction. Is,
The second sensor, when in use, has its detection unit opposed to the second detected surface in the axial direction.
The wheel bearing rolling bearing unit with a physical quantity measuring device according to claim 1.   The second sensor is embedded in a sensor holder made of synthetic resin, and the magnetic shield member is sandwiched between a detection portion of the second sensor and a detection surface of the first encoder. The wheel bearing rolling bearing unit with a physical quantity measuring device according to any one of claims 1 and 2, wherein the wheel bearing rolling bearing unit is coupled and fixed to the sensor holder in a state of being disposed on the wheel.   The magnetic shield member is sandwiched between the detection part of the second sensor and the second detected surface of the second encoder in a state where the sensor holder in which the second sensor is embedded is housed inside. The rolling bearing unit for supporting a wheel with a physical quantity measuring device according to claim 3, which is a sensor case having an opening at a certain position.   The wheel support rolling bearing with a physical quantity measuring device according to any one of claims 3 to 4, wherein the magnetic shield member is coupled and fixed to the sensor holder along with the injection molding of the sensor holder. unit.

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