JP5306577B2 - Bearing and load measuring method for automobile wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for automobile wheels and a load measurement method that facilitats measurement of loads and the moments. <P>SOLUTION: The bearing 1 for automobile wheels comprises: an inner race 2, having a flange section 26 for engaging a hub bolt 261; and an outer race 3 extrapolated to the inner race 2 via two rows of bearing balls 40, arranged in the direction of the axis center of the inner race 2. The outer race 3 comprises: an inner-periphery section 31 that is in contact with each row of bearing balls 40; and an outer-periphery section 32, that is arranged at the outer-periphery side of the inner-periphery section 31 and elastically holds the inner-periphery section 31. A sensor (load sensor 5), for distortion measurement for measuring the distortions generated between the inner-periphery section 31 and the outer-periphery section 32, is arranged at least at one location between the outer-periphery section 32 and the inner-periphery section 31. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a bearing for an automobile wheel incorporating a load sensor and a load measuring method for measuring a load acting on the wheel.

2. Description of the Related Art Conventionally, an apparatus that measures a load acting on a wheel of an automobile or the like and measures a friction force or a friction coefficient acting on the wheel is known (see, for example, Patent Document 1). In this apparatus, a load sensor composed of a strain gauge is disposed in a wheel bearing and a suspension mechanism for suspending the wheel, and the load acting on the wheel is measured by the load sensor.
However, the conventional load measuring device has a problem that even if it can measure the load in the longitudinal direction or the vertical direction of the axle, it cannot measure the moment corresponding to the rotational force that tilts the axle.

Japanese Patent Publication No. 6-70600

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a bearing for an automobile wheel and a load measuring method capable of easily measuring a load and a moment.

The reference invention is an automobile having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing ball rows arranged in the axial direction of the inner race. In wheel bearings,
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Each of the pair of positions between the outer peripheral portion and the inner peripheral portion and symmetric with respect to the rotational axis of the inner race is distorted between the inner peripheral portion and the outer peripheral portion. Sensors for measuring strain for measurement are arranged in pairs as two sensor pairs,
The two strain measuring sensors constituting the sensor pair are arranged in parallel with each other along the axial direction,
The sensor pair comprising the two strain measurement sensors arranged in parallel has a position in the axial direction between the two bearing ball rows. It is in.

Next, the effects of the reference invention will be described.
In the bearing for an automobile wheel according to the reference invention, the strain measuring sensor is provided between the inner peripheral portion of the outer race that pivotally supports the inner race and the outer peripheral portion that elastically holds the inner peripheral portion. Is arranged. For this reason, the strain measuring sensor can measure the strain generated between the inner peripheral portion and the outer peripheral portion, and based on this strain, the wheel load acting on the flange portion of the inner race is indirectly measured. Can be measured automatically.

  Further, by arranging two strain measuring sensors in parallel in the axial direction, it is possible to measure a moment corresponding to a rotational force that tilts the axle. That is, for example, when a load orthogonal to the axial direction acts on the flange portion, a moment is generated to rotate the entire inner race. At this time, stress is applied between the outer peripheral portion and the inner peripheral portion of the outer race, but the stress varies depending on the position in the axial direction. The moment can be obtained based on the difference in strain based on the difference in stress. Therefore, if two strain measuring sensors are arranged in parallel in the axial direction and the amount of strain at each position is measured, the moment can be easily measured.

As described above, according to the reference invention , it is possible to provide a bearing for an automobile wheel capable of easily measuring a load and a moment.

According to a first aspect of the present invention, there is provided an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
The load sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion vertically above and below the rotation axis of the inner race, two by two at an arrangement pitch L1 in the axial direction.
Of the two load sensors arranged on the upper side, the load fz1 is detected by the load sensor on the side closer to the flange part, the load fz2 is detected by the load sensor on the far side, and the two load sensors arranged on the lower side The load fz3 is detected by the load sensor on the side closer to the flange part, and the load fz4 is detected by the load sensor on the far side,
Based on these loads fz1, fz2, fz3, and fz4, the vertical load Fz = k1 {(fz1 + fz2) − (fz3 + fz4)} [k1: coefficient] acting on the wheel, and the moment Mx = k2 about the longitudinal axis {(Fz1 + fz4) − (fz2 + fz3)} × L1 [k2: coefficient] is found in the load measuring method for an automobile wheel.

In the load measuring method, the inner peripheral portion and the outer peripheral portion are measured by a load sensor disposed between the inner peripheral portion that pivotally supports the inner race and the outer peripheral portion that elastically holds the inner peripheral portion. It is possible to measure the load acting between the parts. Therefore, the wheel load acting on the flange portion of the inner race can be indirectly measured.
Two load sensors are arranged in parallel in the axial direction. Therefore, the moment corresponding to the rotational force that tilts the axle can be measured.

  The load sensors are respectively disposed at positions vertically above and below the rotation axis of the inner race. Therefore, by measuring the load with the load sensor arranged at each position and obtaining the difference between the total of the measured value by the upper load sensor and the total of the measured value by the lower load sensor, The direction load Fz or its partial load can be derived. Since the partial load is approximately proportional to the load Fz, the load Fz can be obtained by multiplying the derived partial load by a predetermined coefficient.

  Also, the sum of the measured value fz1 measured by the upper load sensor near the flange and the measured value fz4 measured by the lower load sensor far from the flange, and the measured value measured by the upper load sensor far from the flange. By obtaining the difference between fz2 and the sum of the measured value fz3 by the lower load sensor on the side close to the flange, and applying the moment arm L1 to this difference, the moment Mx around the longitudinal axis or its partial moment can be derived. it can. Since the partial moment is substantially proportional to the moment Mx, the moment Mx can be obtained by multiplying the derived partial moment by a predetermined coefficient.

  As described above, according to the present invention, it is possible to provide a load measuring method for an automobile wheel that can easily measure the load in the vertical direction and the moment about the longitudinal axis.

A second invention includes an inner race having a flange portion for engaging a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing ball rows arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
Two load sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion in the horizontal front and the rear with respect to the rotation axis of the inner race at a pitch L2 in the axial direction.
Of the two load sensors arranged on the front side, the load fx1 is detected by the load sensor closer to the flange portion, the load fx2 is detected by the load sensor on the far side, and the two load sensors arranged on the rear side. The load fx3 is detected by the load sensor on the side close to the flange part, and the load fx4 is detected by the load sensor on the far side,
Based on these loads fx1, fx2, fx3, and fx4, the load Fx = k3 {(fx1 + fx2) − (fx3 + fx4)} [k3: coefficient] acting on the wheel and the moment Mz = k4 about the vertical axis {(Fx1 + fx4)-(fx2 + fx3)} × L2 [k4: coefficient] is found in the load measuring method for an automobile wheel.

In the present invention, as in the first invention , the wheel load acting on the flange portion of the inner race can be indirectly measured, and the moment corresponding to the rotational force that tilts the axle is measured. be able to.

  The load sensors are respectively disposed at positions that are horizontally forward and backward with respect to the rotation axis of the inner race. Therefore, before and after acting on the wheel, the load is measured by the load sensor arranged at each position, and the difference between the total of the measured value by the front load sensor and the total of the measured value by the rear load sensor is obtained. The direction load Fx or its partial load can be derived. Since the partial load is approximately proportional to the load Fx, the load Fx can be obtained by multiplying the derived partial load by a predetermined coefficient.

  Further, the sum of the measured value fx1 from the front load sensor near the flange and the measured value fx4 from the rear load sensor far from the flange, and the measured value from the upper load sensor far from the flange. By obtaining the difference between fx2 and the sum of the measured value fx3 measured by the rear load sensor on the side close to the flange, and applying the moment arm L2 to this difference, the moment Mz around the vertical axis or its partial moment can be derived. it can. Since the partial moment is substantially proportional to the moment Mz, the moment Mz can be obtained by multiplying the derived partial moment by a predetermined coefficient.

  As described above, according to the present invention, it is possible to provide a load measuring method for an automobile wheel that can easily measure the load in the front-rear direction and the moment about the vertical axis.

According to a third aspect of the present invention, there is provided an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
Two load sensors are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion vertically above, below, horizontally forward, and rearward with respect to the rotation axis of the inner race. And
Of the two load sensors arranged on the upper side, the load fz1 is detected by the load sensor on the side closer to the flange part, the load fz2 is detected by the load sensor on the far side, and the two load sensors arranged on the lower side The load fz3 is detected by the load sensor on the side closer to the flange part, and the load fz4 is detected by the load sensor on the far side,
Based on these loads fz1, fz2, fz3, and fz4, the vertical load Fz = k1 {(fz1 + fz2) − (fz3 + fz4)} [k1: coefficient] acting on the wheel, and the moment Mx = k2 about the longitudinal axis {(Fz1 + fz4) − (fz2 + fz3)} × L [k2: coefficient]
Of the two load sensors arranged on the front side, the load fx1 is detected by the load sensor closer to the flange portion, the load fx2 is detected by the load sensor on the far side, and the two load sensors arranged on the rear side. The load fx3 is detected by the load sensor on the side close to the flange part, and the load fx4 is detected by the load sensor on the far side,
Based on these loads fx1, fx2, fx3, and fx4, the load Fx = k3 {(fx1 + fx2) − (fx3 + fx4)} [k3: coefficient] acting on the wheel and the moment Mz = k4 about the vertical axis {(Fx1 + fx4)-(fx2 + fx3)} × L [k4: coefficient] is found in the load measuring method for an automobile wheel.

According to the present invention, both the operational effects of the first invention and the operational effects of the second invention described above can be achieved. That is, the load in the vertical direction and the load in the front-rear direction applied to the wheel can be easily measured, and the moment about the front-rear axis and the moment about the vertical axis can be easily measured.

According to a fourth aspect of the present invention, there is provided an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel on the outer peripheral surface of the inner peripheral part vertically above and below the rotational axis of the inner race, each in parallel at an arrangement pitch L1 in the axial direction.
Of the two displacement sensors arranged on the upper side, the displacement hz1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hz2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the lower side. The displacement hz3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hz4 is detected by the displacement sensor on the far side,
Based on these displacements hz1, hz2, hz3, and hz4, the vertical load Fz = j1 {(hz1 + hz2) − (hz3 + hz4)} [j1: coefficient] acting on the wheel, and the moment Mx = j2 about the longitudinal axis {(Hz1 + hz4)-(hz2 + hz3)} × L1 [j2: coefficient] A load measuring method for an automobile wheel, characterized by:

In the load measuring method, the inner peripheral portion and the outer peripheral portion are disposed by a displacement sensor disposed between the inner peripheral portion that pivotally supports the inner race and the outer peripheral portion that elastically holds the inner peripheral portion. The displacement between the parts can be measured. Therefore, based on this displacement, the wheel load acting on the flange portion of the inner race can be indirectly measured.
Two displacement sensors are arranged in parallel in the axial direction. Therefore, the moment corresponding to the rotational force that tilts the axle can be measured based on the two displacements measured by the respective displacement sensors.

  The displacement sensors are respectively disposed at positions vertically above and below the rotation axis of the inner race. For this reason, the load is measured by the displacement sensor arranged at each position, and the difference between the total of the measurement values by the upper displacement sensor and the total of the measurement values by the lower displacement sensor is obtained, which is approximately proportional to this difference. The vertical load Fz acting on the wheel can be derived.

  Also, the sum of the measured value fz1 from the upper displacement sensor near the flange and the measured value fz4 from the lower displacement sensor far from the flange, and the measured value from the upper displacement sensor far from the flange. By obtaining a difference between fz2 and the sum of the measured value fz3 by the lower displacement sensor on the side close to the flange, and multiplying this by the proportionality constant j2 and the moment arm L1, the moment Mx about the longitudinal axis can be derived. it can.

  As described above, according to the present invention, it is possible to provide a load measuring method for an automobile wheel that can easily measure the load in the vertical direction and the moment about the longitudinal axis.

According to a fifth aspect of the present invention, there is provided an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion in the horizontal front and rear with respect to the rotation axis of the inner race at a pitch L2 in the axial direction.
Of the two displacement sensors arranged on the front side, the displacement hx1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hx2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the rear side The displacement hx3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hx4 is detected by the displacement sensor on the far side,
Based on these displacements hx1, hx2, hx3, hx4, the longitudinal displacement Fx = j3 {(hx1 + hx2) − (hx3 + hx4)} [j3: coefficient] acting on the wheel and the moment Mz = j4 about the vertical axis {(Hx1 + hx4)-(hx2 + hx3)} × L2 [j4: Coefficient] is found in the load measuring method for an automobile wheel.

Also in the present invention, as in the fourth aspect of the invention , the wheel load acting on the flange portion of the inner race can be indirectly measured, and the moment corresponding to the rotational force that tilts the axle is measured. be able to.

  The displacement sensors are respectively disposed at positions that are horizontally forward and rearward with respect to the rotation axis of the inner race. Therefore, the displacement is measured by the displacement sensors arranged at the respective positions, and the difference between the total of the measurement values by the front displacement sensor and the total of the measurement values by the rear displacement sensor is obtained, and is approximately proportional to this difference. The load Fx in the front-rear direction acting on the wheel can be guided.

  Further, the sum of the measured value fx1 from the front displacement sensor near the flange portion and the measured value fx4 from the rear displacement sensor far from the flange portion, and the measured value from the upper displacement sensor far from the flange portion. The difference between fx2 and the sum of the measured value fx3 measured by the rear displacement sensor on the side close to the flange portion is obtained, and the proportional constant j4 and the moment arm L2 are multiplied by this to derive the moment Mz around the vertical axis. it can.

  As described above, according to the present invention, it is possible to provide a load measuring method for an automobile wheel that can easily measure the load in the front-rear direction and the moment about the vertical axis.

According to a sixth aspect of the present invention , an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing ball rows arranged in the axial direction of the inner race. In a bearing for an automobile wheel having
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion vertically above, below, horizontally forward, and rearward with respect to the rotation axis of the inner race. And
Of the two displacement sensors arranged on the upper side, the displacement hz1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hz2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the lower side. The displacement hz3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hz4 is detected by the displacement sensor on the far side,
Based on these displacements hz1, hz2, hz3, and hz4, the vertical load Fz = j1 {(hz1 + hz2) − (hz3 + hz4)} [j1: coefficient] acting on the wheel, and the moment Mx = j2 about the longitudinal axis {(Hz1 + hz4) − (hz2 + hz3)} × L [j2: coefficient]
Of the two displacement sensors arranged on the front side, the displacement hx1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hx2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the rear side The displacement hx3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hx4 is detected by the displacement sensor on the far side,
Based on these displacements hx1, hx2, hx3, and hx4, the load Fx = j3 {(hx1 + hx2) − (hx3 + hx4)} [j3: coefficient] acting on the wheel and the moment about the vertical axis Mz = j4 {(Hx1 + hx4)-(hx2 + hx3)} × L [j4: coefficient] is found in the load measuring method for an automobile wheel.

According to the present invention, both the operational effects of the fourth invention and the operational effects of the fifth invention described above can be achieved. That is, the load in the vertical direction and the load in the front-rear direction applied to the wheel can be easily measured, and the moment about the front-rear axis and the moment about the vertical axis can be easily measured.

In the above reference invention , it is preferable that the strain measuring sensor is disposed on the outer peripheral surface of the inner peripheral portion in one or both of the upper and lower directions in the vertical direction with respect to the rotation axis of the inner race.
In this case, it is possible to easily measure the vertical load applied to the wheel and the moment about the longitudinal axis.
In addition, it is preferable that the strain measuring sensor is arranged on both the upper and lower sides.

The strain measurement sensor is preferably disposed on the outer peripheral surface of the inner peripheral portion in either or both of the front and rear in the horizontal direction with respect to the rotation axis of the inner race.
In this case, the longitudinal load on the wheel and the moment about the vertical axis can be easily measured.
The strain measuring sensors are preferably arranged on both the front and rear sides.

In the outer race, the outer peripheral portion and the inner peripheral portion are integrally formed as one component, and a through-hole penetrating in the axial direction is formed between the outer peripheral portion and the inner peripheral portion. It is preferable that the strain measurement sensor is disposed in the through hole.
In this case, the inner peripheral portion facing the through hole is moderately suppressed in rigidity, and elastic deformation suitable for sensing a load acting from the inner peripheral portion is likely to occur in the inner peripheral portion. Can do.
And, by the strain measuring sensor arranged between the inner peripheral portion and the outer peripheral portion, the strain between the inner peripheral portion and the outer peripheral portion based on the load acting on the inner peripheral portion from the inner race, It can measure with high accuracy.

Further, the strain measuring sensor is preferably a load sensor that measures a load acting on the outer peripheral portion from the inner peripheral portion, and is preferably arranged in parallel in the axial direction.
In this case, a load acting on the outer peripheral portion from the inner peripheral portion can be detected, and based on this, the load and moment of the wheel acting on the flange portion of the inner race can be easily measured.

That is, the load sensor can measure the load acting between the inner peripheral portion and the outer peripheral portion, and can indirectly measure the wheel load acting on the flange portion of the inner race. .
Further, since the two load sensors are arranged in parallel in the axial direction, the moment corresponding to the rotational force for inclining the axle can be measured. That is, for example, when a load orthogonal to the axial direction acts on the flange portion, a moment is generated to rotate the entire inner race. At this time, stress is applied between the outer peripheral portion and the inner peripheral portion of the outer race, but the stress varies depending on the position in the axial direction. The moment can be obtained based on the difference in stress. Therefore, if the stress is measured with two load sensors arranged in parallel, the moment can be easily measured.

  The arrangement pitch of the two load sensors arranged in parallel in the axial direction is preferably 2.0 to 20 mm, for example. In this case, the moment can be measured more accurately without hindering the downsizing of the bearing.

Further, it is preferable that a preload is applied to the load sensor in advance.
In this case, measurement is possible even for a negative load applied to the load sensor. In addition, it is possible to accurately measure even a small load range.

The load sensor is preferably a ceramic sensor.
In this case, using the ceramic sensor having a high rigidity and a small amount of deformation with respect to the load, while supporting the inner peripheral portion with high rigidity with respect to the outer peripheral portion, The acting load can be measured with high accuracy.
According to the ceramic sensor having high rigidity, the rigidity of the entire outer race can be maintained high by supporting the inner peripheral portion with high rigidity.

Various ceramic sensors may be used as long as they are mainly made of a ceramic material and can withstand high loads. Among them, it is particularly preferable to apply a sensor manufactured from a mechanical quantity sensor material having the following characteristics.
As a suitable mechanical quantity sensor material, for example, there is a material in which a pressure resistance effect material is dispersed so as to be electrically continuously connected to a matrix made of an electrically insulating ceramic material. In this mechanical quantity sensor material, a material for exerting a pressure resistance effect is dispersed with respect to a material excellent in strength called a ceramic material.
In addition, a sensor element using a pressure sensitive body in which RuO ₂ is dispersed as conductive particles in a glass matrix can be used as the load sensor.

Examples of the ceramic material that can serve as the matrix include ZrO ₂ , Al ₂ O ₃ , MgAl ₂ O ₄ , SiO ₂ , 3Al ₂ O ₃ .2SiO ₂ , Y ₂ O ₃ , CeO ₂ , La ₂ O ₃ , and Si ₃ N. ₄ and one or more substances selected from these solid solutions.

As the pressure resistance effect _{material, (Ln 1-x Ma x} ) of perovskite structure _1-y MbO _3-z (here 0 <x ≦ 0.5,0 ≦ y ≦ 0.2,0 ≦ z ≦ 0.6, Ln; lanthanoid element, Ma; 1 or more kinds of alkaline earth elements, Mb; 1 kind or more transition metal _{elements), (Ln 2-u Ma} u layered perovskite structure) _1-v Mb ₂ O _7-w (where 0 <u ≦ 1.0, 0 ≦ v ≦ 0.2, 0 ≦ w ≦ 1.0, Ln; rare earth element, Ma; one or more alkaline earth elements , Mb; one or more transition metal elements), Si, and a substance composed of any one or more of substances obtained by adding a trace amount of additive elements to these.
Moreover, this pressure resistance effect material can be made into various particle | grain forms, such as spherical shape, ellipse shape, and fibrous form.

In the ceramic sensor produced from the above-mentioned mechanical quantity sensor material, the above-mentioned ceramic material bears a resistance force against a high load, a high pressure and the like, so that it becomes a high strength sensor.
Moreover, in this mechanical quantity sensor material, since said pressure resistance effect material exists so that it may connect continuously inside a ceramic material, each pressure resistance effect material is in an electrically continuous state.
And in this mechanical quantity sensor material, the characteristic that an electrical resistance value changes can be demonstrated by applying a pressure and a load similarly to the normal sensor material comprised only with the pressure resistance effect material.

Therefore, when a ceramic sensor made from this mechanical quantity sensor material is applied, it can withstand high stresses and high loads and measure mechanical quantities such as compressive loads.
And according to such a ceramic sensor, it can be utilized as a part for structural members, such as a machine part, besides being utilized as a sensor for load measurement. That is, the rigidity of the whole outer race can be improved by supporting the inner peripheral portion with high rigidity with respect to the outer peripheral portion.

The strain measuring sensor is preferably a displacement sensor that measures a displacement between the inner peripheral portion and the outer peripheral portion, and is preferably arranged in parallel in the axial direction.
In this case, the displacement between the inner peripheral portion and the outer peripheral portion can be detected, and based on this, the load and moment of the wheel acting on the flange portion of the inner race can be easily measured.

  The arrangement pitch of the two displacement sensors arranged in parallel in the axial direction is preferably 2.0 to 20 mm, for example. In this case, the moment can be measured more accurately without hindering the downsizing of the bearing.

In the third aspect of the invention , the bearing for the automobile wheel is formed from the inner race through the bearing ball row on the side close to the flange portion when a load is applied to the vehicle body in the axial direction on the wheel. The pressing force to the inner peripheral portion of the outer race increases, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row far from the flange portion decreases,
When a load is applied to the wheel on the side opposite to the vehicle body in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion decreases. The pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is increased.
Based on the loads fx1, fx2, fx3, fx4, fz1, fz2, fz3, and fz4, a load Fy = k5 {(fz1 + fx3 + fx1 + fx3) − (fz2 + fxz + fx2 + fx4)} [k5: coefficient] is obtained. Is preferred.

In this case, the axial load applied to the wheel can be easily measured.
That is, when a load Fy is applied to the vehicle body side in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion increases. The pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is reduced. As a result, the loads fz1, fz3, fx1, and fx3 applied to the load sensor closer to the flange portion increase, and the loads fx2, fz4, fx2, and fx4 applied to the far side load sensor decrease.

When a load Fy is applied to the opposite side of the vehicle body in the axial direction, a reverse phenomenon occurs.
Therefore, by calculating the difference between the total load applied to the load sensor near the flange and the total load applied to the far side load sensor, it is possible to measure the partial load of the load in the axial direction. Become.

In the sixth aspect of the invention , the bearing for the automobile wheel is formed from the inner race via the bearing ball row on the side close to the flange portion when a load is applied to the vehicle body in the axial direction on the wheel. The pressing force to the inner peripheral portion of the outer race increases, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row far from the flange portion decreases,
When a load is applied to the wheel on the side opposite to the vehicle body in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion decreases. The pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is increased.
Based on the displacements hx1, hx2, hx3, hx4, hz1, hz2, hz3, hz4, the axial load Fy = j5 {(hz1 + hz3 + hx1 + hx3) − (hz2 + hz4 + hx2 + hx4)} [j5: coefficient] is obtained. Is preferred.

In this case, the axial load applied to the wheel can be easily measured.
That is, when a load Fy is applied to the vehicle body side in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion increases. The pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is reduced. As a result, the displacements hz1, hz3, hx1, and hx3 measured by the displacement sensor closer to the flange portion increase, and the displacements hz2, hz4, hx2, and hx4 measured by the far side displacement sensor decrease.

When a load Fy is applied to the opposite side of the vehicle body in the axial direction, a reverse phenomenon occurs.
Accordingly, the difference between the total displacement measured by the displacement sensor closer to the flange portion and the total displacement measured by the far side displacement sensor is obtained, and by multiplying this difference by the coefficient j5, the axial direction It is possible to measure the load.

Example 1
A bearing for an automobile wheel and a load measuring method according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the bearing 1 for an automobile wheel of the present example has an inner race 2 having a flange portion 26 for engaging the hub bolt 261, and an axial direction (Y-axis direction) of the inner race 2. And an outer race 3 that is externally inserted into the inner race 2 via two rows of bearing ball rows 40 arranged.

The outer race 3 has an inner peripheral portion 31 that contacts each bearing ball row 40 and an outer peripheral portion 32 that is disposed on the outer peripheral side of the inner peripheral portion 31 and elastically holds the inner peripheral portion 31. doing.
Then, two load sensors 5 for measuring the load acting on the outer peripheral portion 32 from the inner peripheral portion 31 are arranged in parallel at four positions between the outer peripheral portion 32 and the inner peripheral portion 31 in the axial direction. is there.

As shown in FIG. 2, the load sensor 5 includes the rotation shaft 21 of the inner race 2 and the rotation shaft 21 of the inner race 2 on the outer peripheral surface of the inner peripheral portion 31 in both the vertical direction (Z-axis direction). Are arranged at a total of four locations on the outer peripheral surface of the inner peripheral portion 31 both in the front and rear in the horizontal direction (X-axis direction).
In addition, in the bearing 1 of this example, it is comprised so that a part of load applied to a wheel may be applied to the load sensor 5, and most of the load is absorbed in the outer race 3 itself.

In the outer race 3, the outer peripheral portion 32 and the inner peripheral portion 31 are integrally formed as one component. A through hole 33 penetrating in the axial direction is formed between the outer peripheral portion 32 and the inner peripheral portion 31, and the load sensor 5 is disposed in the through hole 33.
A preload is applied to the load sensor 5 in advance. This preload is 50 MPa for each load sensor 5.
The load sensor 5 is a ceramic sensor.

  Below, it explains in full detail about the structure of the bearing 1 for motor vehicle wheels of this example. As shown in FIG. 1, the bearing 1 rotatably supports the inner race 2 inserted in the outer race 3 via two rows of bearing ball rows 40 arranged between the outer race 3 and the inner race 2. Bearing.

Here, as shown in FIG. 1 to FIG. 3, in each of the bearing ball rows 40, a plurality of rolling balls 41 are configured to be held at an equal distance in the circumferential direction by a cage (not shown). The rolling balls 41 are interposed between the double-row outer raceway surface 34 and the inner raceway surface 24 so as to roll on the respective raceway surfaces.
In this example, the bearing ball row 40 is constituted by a plurality of spherical rolling balls 41, but instead of the rolling balls 41, tapered rollers can be used.

As shown in FIG. 2, the outer race 3 is integrally formed with an inner peripheral portion 31 and an outer peripheral portion 32 arranged so as to exhibit a coaxial double structure.
And between the inner peripheral part 31 and the outer peripheral part 32, the through-hole 33 penetrated to an axial direction is provided in four places equally spaced in the circumferential direction. A bridge portion 35 that connects the inner peripheral portion 31 and the outer peripheral portion 32 is formed in the gap between the through holes 33 adjacent in the circumferential direction.

The through-hole 33 of this example is in the central portion in the circumferential direction, and is accommodated in a state of being inclined along the arc direction around the axial center with the accommodating portion 331 having a substantially rectangular cross section that accommodates the load sensor 5. It is formed from an elastically deforming portion 332 having an elongated cross-sectional shape adjacent to both sides of the portion 331.
The through-hole 33 is formed so as to exhibit a substantially arc-shaped cross-sectional shape as a whole.

As shown in FIG. 2, the inner peripheral portion 31 and the outer peripheral portion 32 are connected by a bridge portion 35 between adjacent through holes 33.
And the inner peripheral part 31 which faces the substantially circular arc-shaped through-hole 33 is formed in the thin circular arc shape, and it is comprised so that it may produce elastic deformation easily.
That is, in the outer race 3 of this example, the thin arc-shaped inner peripheral portion 31 is elastically deformed by the load transmitted from the inner race 2, and the inner peripheral portion 31 is slightly relative to the outer peripheral portion 32. It is comprised so that it can move.

Further, as shown in the figure, the load sensor 5 is disposed in the through hole 33 of the outer race 3 of the present example in a state where the load measuring surface is in contact with the outer peripheral surface of the inner peripheral portion 31 having a thin arc shape. It is.
Then, according to the load sensor 5 brought into contact with the outer peripheral surface of the inner peripheral portion 31, the load acting on the outer peripheral portion 32 from the inner peripheral portion 31 can be directly measured.

  In the outer race 3 of this example, as shown in FIG. 1, a positioning unit (not shown) that protrudes from the inner peripheral surface of the outer peripheral portion 32 toward the through hole 33 includes a sensor unit including two load sensors 5. 50, the load sensor 5 is fixed at a predetermined position in the through hole 33. As shown in FIGS. 1, 3, and 4, two load sensors 5 arranged in the sensor unit 50 are arranged in the axial direction (Y-axis direction) with a pitch L = 7.5 mm. .

In order to accommodate the sensor unit 50 in the through hole 33, the opening of the through hole 33 is forcibly expanded in the radial direction using a jack or the like, and the sensor unit 50 enters the through hole 33 from the opening side. 50 is inserted.
Here, in this example, the dimensions of each part such as the through-hole 33, the sensor unit 50, the load sensor 5 and the like are applied to the load sensor 5 accommodated in the through-hole 33 so that a preload of 50 MPa is applied thereto. Etc. are designed. Further, the zero point correction of each load sensor 5 is performed in advance based on the preload value measured by each load sensor 5 to suppress the influence of dimensional errors and the like on the preload.

  Thus, according to each load sensor 5 to which a preload is applied, it is possible to accurately measure even a small load range. Furthermore, it is possible to measure a load lower than the preload, that is, a tensile load. Further, according to the load sensor 5 in which the zero point is corrected in advance based on the actually measured preload value, load measurement with higher accuracy can be performed.

Here, as shown in FIG. 5A, the load sensor 5 applied in this example is a sensor manufactured from a mechanical quantity sensor material 51 (FIG. 6) described later.
As shown in FIG. 5A, electrodes 519 for connecting lead wires 518 are formed on both end faces of a 2 mm thick ceramic block having a load measuring surface of 2 mm in length and 2 mm in width to form a load sensor 5. It is as.

The sensor unit 50 can be configured by individually preparing two load sensors 5 and then arranging them at a pitch L. As shown in FIG. It can also be configured by integrally manufacturing from one ceramic body so that the pitch between them is L. The electrode 519 may be formed on the entire surface of both ends of the load sensor 5 as shown in FIG. 5A, or may be formed on a part of both ends of the load sensor 5 as shown in FIG. May be.
In this example, the load sensor 5 is configured to generate a displacement of about 1 μm with respect to a load in the vertical direction of 100 MPa.

In the outer race 3 of this example, as shown in FIG. 2, at four locations on the outer peripheral surface of the inner peripheral portion 31 corresponding to the vertical vertical direction (Z-axis direction) and the horizontal front-rear direction (X-axis direction) of the automobile. Each of the load sensors 5 is arranged in parallel in the axial direction (Y-axis direction).
Therefore, according to the outer race 3 of this example, based on the load measured by the load sensor 5, the load acting in the vertical vertical direction and the horizontal front-back direction of the wheel can be accurately measured.

  Further, as shown in FIGS. 1 and 3, double row outer raceway surfaces 34 are formed on two inner peripheral surfaces in the axial direction of the inner peripheral portion 31. Each outer raceway surface 34 is a curved surface that is recessed inward in the axial direction of the inner peripheral portion 31. The rolling balls 41 of the bearing ball row 40 are configured to roll along the outer raceway surface 34.

As shown in FIGS. 1 and 3, the inner diameter of the intermediate portion sandwiched between the outer raceway surfaces 34 is formed to be smaller than both end portions. That is, in the outer race 3 of this example, the rolling balls 41 of each bearing ball row 40 are inserted and arranged from both ends in the axial direction.
As shown in FIG. 2, a mounting member on the vehicle body side, for example, a knuckle arm extending from a suspension device, is attached to the end surface of the outer peripheral portion 32 on the opposite side of the flange portion 26 of the inner race 2. A vehicle body side flange portion 325 is formed. Further, the vehicle body side flange portion 325 is provided with a bolt hole 326 for fixing the knuckle arm.

Next, the mechanical quantity sensor material 51 used in this example will be described. As shown in FIG. 6, the mechanical quantity sensor material 51 is a material in which a pressure resistance effect material 512 is dispersed in a matrix made of an electrically insulating ceramic material 511 so as to be electrically continuously connected.
In addition, as shown in the figure, some pressure resistance effect materials 513 are not electrically continuous but may exist in the ceramic 511 material in isolation.
In this example, ZrO ₂ added with 12 mol% of CeO ₂ was used as the electrically insulating ceramic material, and La _0.8 Sr _0.2 MnO ₃ was used as the pressure resistance effect material.
In addition, a sensor element using a pressure sensitive body in which RuO ₂ is dispersed as conductive particles in a glass matrix can be used as the load sensor 5.

Next, as shown in FIG. 1, the inner race 2 has an insertion portion 28 inserted into the outer race 3 and a flange portion 26 that engages with the hub bolt 261.
The end surface of the flange portion 26 on the side from which the hub bolt 261 protrudes is a mounting surface for mounting a brake disk (not shown). Further, a wheel (not shown) is attached to the flange portion 26 via the brake disk by a hub bolt 261 that engages with the flange portion 26.

  As shown in FIG. 1, the insertion portion 28 of the inner race 2 includes a main shaft portion 281 formed with an inner raceway surface 24, a ring-shaped pressure ring 283 that is extrapolated to the main shaft portion 281, and a main shaft portion 281. It has a three-part structure composed of a shaft nut 285 that is screwed into a screw portion 288 at the tip of the shaft and presses the pressure ring 283 in the axial direction.

  The inner raceway surface 24 of the main shaft portion 281 is a curved surface that is recessed toward the flange portion 26 as shown in FIG. The inner raceway surface 24 is configured to hold the rolling balls 41 of the bearing ball row 40 so as to roll between the outer raceway surfaces 34 formed on the inner peripheral portion 31.

Further, as shown in FIGS. 1 and 3, the pressure ring 283 is formed with an inner raceway surface 24 that is recessed in a curved shape. When the pressure ring 283 is extrapolated to the inner race 2 from the screw portion 288 side, the inner raceway surface 24 is arranged to face the inner raceway surface 24 of the main shaft portion 281. .
The inner raceway surface 24 is configured to hold the rolling balls 41 of the bearing ball row 40 so as to roll between the outer raceway surfaces 34 formed on the inner peripheral portion 31.

  Further, as shown in FIG. 4, the direction of the pressing force Fa applied from the inner raceway surface 24 near the flange portion 26 to the outer raceway surface 34 via the bearing ball row 40 is relative to the axial direction (Y-axis direction). And an angle of 40 °. Further, the direction of the pressing force Fb applied from the inner raceway surface 24 on the side far from the flange portion 26 to the outer raceway surface 34 via the bearing ball row 40 is an angle of 140 ° with respect to the axial direction (Y-axis direction). Have. Therefore, when no axial load is applied to the wheel, Fa = Fb, the Y-axis direction components cancel each other, and the Z-axis and X-axis direction component loads are applied from the inner race 2 to the outer race 3. It becomes.

  However, when a load Fy on the vehicle body side (Y direction + side) in the axial center direction is applied to the wheel, the inner peripheral portion of the outer race 3 from the inner race 2 via the bearing ball row 40 on the side close to the flange portion 26. The pressing force Fa to 31 increases, and the pressing force Fb from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange portion 26 decreases.

As a result, the load applied to the load sensor 501 (503, 505, 507) on the side close to the flange portion 26 of the two load sensors 5 arranged in parallel in the axial direction increases, and the load sensor 502 (504, 504, 504, 504, 504, 504, 504, 504) 506, 508) is reduced.
Therefore, it is possible to measure the load in the axial direction (Y-axis direction) based on the difference between the two loads (see Equation 5 described later).

  Further, when a load is applied to the wheel on the side opposite to the vehicle body in the axial direction (the Y direction minus side), the inner circumference of the outer race 3 is changed from the inner race 2 through the bearing ball row 40 on the side close to the flange portion 26. The pressing force Fa to the portion 31 decreases, and the pressing force Fb from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange portion 26 increases.

As a result, the load applied to the load sensor 501 (503, 505, 507) on the side close to the flange portion 26 of the two load sensors 5 arranged in parallel in the axial direction is reduced, and the load sensor 502 (504, 504, 504, 504, 504, 504, 504, 504, 504, 504) 506, 508) load increases.
Also in this case, the load in the axial direction (Y-axis direction) can be measured based on the difference between the two loads.

  As shown in FIGS. 1 and 3, the shaft nut 285 is screwed into the screw portion 288 at the tip of the main shaft portion 281, so that the pressure ring 283 is formed at the end surface in the axial direction of the shaft nut 285. It is comprised so that can be pressed. A predetermined preload can be applied to the bearing ball row 40 by adjusting the tightening amount of the shaft nut 285.

  Further, in the bearing 1 in which the outer race 3 and the inner race 2 are assembled, between the inner race 2 and the outer race 3, in order to prevent intrusion of moisture, dust and the like into each bearing ball row 40, A sealing material (not shown) is arranged.

Next, the load measuring method of this example using the load sensor 5 will be described.
Two load sensors 5 are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion 31 vertically above, below, horizontally forward, and rearward with respect to the rotation shaft 21 of the inner race 2. (See FIG. 4). This arrangement pitch L becomes a moment arm of the following moments Mx and Mz.

  As shown in FIG. 1, among the two load sensors 5 arranged on the upper side, the load fz1 is detected by the load sensor 501 on the side closer to the flange 26, and the load fz2 is detected by the load sensor 502 on the far side. Further, of the two load sensors 5 arranged on the lower side, the load fz3 is detected by the load sensor 503 on the side close to the flange portion 26, and the load fz4 is detected by the load sensor 504 on the far side.

Based on these loads fz1, fz2, fz3, and fz4, the vertical load Fz and the moment Mx about the longitudinal axis that acted on the wheel are obtained by the following expressions 1 and 2, respectively. Here, k1 and k2 are coefficients.
Fz = k1 {(fz1 + fz2)-(fz3 + fz4)} (Expression 1)
Mx = k2 {(fz1 + fz4) − (fz2 + fz3)} × L (Expression 2)

  Further, as shown in FIG. 3, the load fx1 is detected by the load sensor 505 near the flange portion 26 of the two load sensors 5 arranged on the front side, and the load fx2 is detected by the load sensor 506 on the far side. The load fx3 is detected by the load sensor 507 on the side close to the flange portion 26, and the load fx4 is detected by the load sensor 508 on the far side.

Based on these loads fx1, fx2, fx3, and fx4, the front-rear direction load Fx and the moment Mz about the vertical axis that are applied to the wheels are obtained by the following expressions 3 and 4, respectively. Here, k3 and k4 are coefficients.
Fx = k3 {(fx1 + fx2) − (fx3 + fx4)} (Equation 3)
Mz = k4 {(fx1 + fx4) − (fx2 + fx3)} × L (Expression 4)

Further, based on the loads fx1, fx2, fx3, fx4, fz1, fz2, fz3, and fz4, the load Fy in the axial direction applied to the wheel is obtained by the following equation (5). Here, k5 is a coefficient.
Fy = k5 {(fz1 + fz3 + fx1 + fx3) − (fz2 + fz4 + fx2 + fx4)} (Expression 5)

Here, the directions of the X axis, the Y axis, and the Z axis in FIGS. That is, the horizontal front-rear direction of the vehicle is the X axis, and the front is +. The vertical direction is the Z axis, and the upper direction is +. The axis direction of the axle is defined as the Y axis, and the direction in which the inner race 2 is inserted into the outer race 3 is defined as +.
The load sensor 5 outputs a positive output when compressed.

Next, as shown in FIGS. 7 to 11, partial loads fx, fy, fz and moments mx, mz in each direction detected when a load is input to the automobile wheel bearing 1 of this example. The size of the was confirmed.
As shown in FIG. 1 and FIG. 3, when the loads of Fx, Fy, and Fz are input as the main axis components, the load and moment measured by the load sensor 5 are as shown in FIG. 7, FIG. 8, and FIG. 9, respectively. It was.

That is, as shown in FIG. 7A, the partial load fx is output for the load Fx of the main shaft component. And fx and Fx have a substantially linear relationship, and have a relationship of fx = 0.025Fx. That is, the coefficient k3 in Equation 3 is k3 = 1 / 0.025.
Further, as shown in FIG. 8B, the partial load fy is output for the load Fy of the main shaft component. And fy and Fy have a substantially linear relationship, and fy = 0.04Fy. That is, the coefficient k5 in Equation 5 is k5 = 1 / 0.04.
Further, as shown in FIG. 9C, the partial load fz is output for the load Fz of the main shaft component. Fz and Fz have a substantially linear relationship, and have a relationship of fz = 0.03Fz. That is, the coefficient k1 in Equation 1 is k1 = 1 / 0.03.

  As shown in FIGS. 1 and 3, when the Fx and Fz loads are offset input in the flange portion 26, the partial load and the partial moment measured by the load sensor 5 are as shown in FIGS. 10 and 11, respectively. there were. The moments Mz and Mx input at this time are Mz = 0.05Fx and Mx = 0.05Fx.

That is, as shown in FIGS. 10A and 10E, the partial load fx and the partial moment mz are output for the offset-input load Fx and moment Mz. The relationship between Mz and mz has a substantially linear relationship, and Mz = 0.003 mz. That is, the coefficient k4 in Equation 4 is k4 = 1 / 0.003.
Further, as shown in FIGS. 11A and 11E, the partial load fz and the partial moment mx are output for the loads Fz and Mx that are offset input. The relationship between Mx and mx is a substantially linear relationship, and Mx = 0.003 mx. That is, the coefficient k2 in Equation 2 is k2 = 1 / 0.003.

In addition, since the hysteresis and nonlinearity are small in the relationship between these inputs and outputs, the input load can be accurately measured.
In addition, an error due to crosstalk occurs in the output. Since this crosstalk is linear, it can be easily corrected by performing linear matrix correction.

Next, the function and effect of this example will be described.
In the automotive wheel bearing 1 of this example, the load is between the inner peripheral portion 31 of the outer race 3 that pivotally supports the inner race 2 and the outer peripheral portion 32 that elastically holds the inner peripheral portion 31. A sensor 5 is arranged. Therefore, the load sensor 5 can measure the load acting between the inner peripheral portion 31 and the outer peripheral portion 32 and indirectly measure the wheel load acting on the flange portion 26 of the inner race 2. Can do.

  Two load sensors 5 are arranged in parallel in the axial direction (Y-axis direction). Therefore, the moment corresponding to the rotational force that tilts the axle can be measured. That is, when a load orthogonal to the axial direction acts on the flange portion 26, a moment is generated to rotate the entire inner race 2. At this time, stress is applied between the outer peripheral portion 32 and the inner peripheral portion 31 of the outer race 3, and the stress varies depending on the position in the axial direction. The moment can be obtained based on the difference in stress. Therefore, if the stress is measured by the two load sensors 5 arranged in parallel, the moment can be easily measured.

As shown in FIGS. 1 and 2, the load sensor 5 is disposed on the outer peripheral surface of the inner peripheral portion 31 both vertically and vertically with respect to the rotation shaft 21 of the inner race 2. Therefore, the load Fz in the vertical direction (Z-axis direction) applied to the wheel and the moment Mx around the front-rear axis (X-axis) can be easily measured.
As shown in FIGS. 2 and 3, the load sensor 5 is disposed on the outer peripheral surface of the inner peripheral portion 31 both in the front and rear directions in the horizontal direction with respect to the rotation shaft 21 of the inner race 2. Therefore, it is possible to easily measure the load Fx in the front-rear direction (X-axis direction) applied to the wheel and the moment Mz around the vertical axis (Z-axis).

The outer race 3 has an outer peripheral portion 32 and an inner peripheral portion 31 integrally formed as one component, and the through hole 100 is formed between the outer peripheral portion 32 and the inner peripheral portion 31. The load sensor 5 is disposed in the through hole 100. Therefore, it is possible to moderately suppress the rigidity of the inner peripheral portion 31 facing the through hole 100 and easily cause elastic deformation suitable for sensing of the load acting from the inner peripheral portion 31 in the inner peripheral portion 31. it can.
The load sensor 5 disposed between the inner peripheral portion 31 and the outer peripheral portion 32 can accurately measure the load applied to the inner peripheral portion 31 from the inner race 2.

  In addition, since a preload is applied to the load sensor 5 in advance, it is possible to measure a negative load applied to the load sensor 5, that is, a load acting in a direction in which the load sensor 5 is depressurized. In addition, it is possible to accurately measure even a small load range.

Further, since the load sensor 5 is made of a ceramic sensor having high rigidity and a small deformation amount with respect to the load, the load sensor 5 is supported between the outer periphery 32 and the inner periphery 31 with high rigidity. The load acting on the can be measured with high accuracy.
According to the ceramic sensor having high rigidity, the rigidity of the entire outer race 3 can be maintained high by supporting the inner peripheral portion 31 with high rigidity.

  Further, the load sensor 5 is disposed at a position vertically above and below the rotation shaft 21 of the inner race 2. Therefore, as described above, the load is measured by the load sensors 5 arranged at the respective positions, and the total of the measured values by the upper load sensors 501 and 502 and the total of the measured values by the lower load sensors 503 and 504 are calculated. By obtaining the difference, the partial load fz of the vertical load Fz acting on the wheel can be derived. Since the partial load fz is substantially proportional to the load Fz, the load Fz can be obtained by multiplying the derived partial load fz by a coefficient k1 (= 1 / 0.03) (see Equation 1 above).

  Further, the sum of the measured value fz1 measured by the upper load sensor 501 near the flange 26 and the measured value fz4 measured by the lower load sensor 504 far from the flange 26, and the upper value farther from the flange 26. By calculating the difference between the measurement value fz2 measured by the load sensor 502 and the sum of the measurement value fz3 measured by the lower load sensor 503 on the side close to the flange portion 26 and multiplying this by the moment arm L, the longitudinal axis (X axis) The turning moment Mx or its partial moment mx can be derived. Since the partial moment mx is substantially proportional to the moment Mx, the moment Mx can be obtained by multiplying the derived partial moment mx by a coefficient k2 (= 1 / 0.003) (see Equation 2 above).

  The load sensors 5 are also arranged at positions that are horizontally forward and rearward with respect to the rotation shaft 21 of the inner race 2. Therefore, as described above, the load is measured by the load sensors 5 arranged at the respective positions, and the sum of the measurement values by the front load sensors 505 and 506 and the sum of the measurement values by the rear load sensors 507 and 508 are calculated. By obtaining the difference, the partial load fx of the load Fx in the front-rear direction acting on the wheel can be derived. Since the partial load fx is substantially proportional to the load Fx, the load Fx can be obtained by multiplying the derived partial load fx by a coefficient k3 (= 1 / 0.025) (see Equation 3 above).

  Further, the sum of the measured value fx1 measured by the front load sensor 505 near the flange portion 26 and the measured value fx4 measured by the rear load sensor 508 far from the flange portion 26, and the upper value farther from the flange portion 26. A difference between the measured value fx2 measured by the load sensor 506 and the sum of the measured value fx3 measured by the rear load sensor 507 on the side close to the flange portion 26 is obtained, and by applying a moment arm L to this difference, a moment Mz about the vertical axis is obtained. The partial moment mz of can be derived. Since the partial moment mz is substantially proportional to the moment Mz, the moment Mz can be obtained by multiplying the derived partial moment mz by a coefficient k4 (= 1 / 0.003) (see Equation 4 above).

  As described above, the load Fz in the vertical direction and the load Fx in the front-rear direction applied to the wheel can be easily measured, and the moment Mx about the front-rear axis and the moment Mz about the vertical axis can be easily measured. .

  Further, as described above, the load Fy in the axial direction (Y-axis direction) applied to the wheel can be obtained based on the loads detected by the load sensors 5 arranged before and after the rotating shaft 21 of the inner race 2. . Therefore, the axial load applied to the wheel can be easily measured.

  That is, when a load Fy is applied to the vehicle body side in the axial direction, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 through the bearing ball row 40 on the side close to the flange portion 26 increases. The pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange portion 26 is reduced. As a result, the loads fz1, fz3, fx1, and fx3 applied to the load sensors 501, 503, 505, and 507 on the side closer to the flange portion 26 are increased, and the loads fz2 applied to the load sensors 502, 504, 506, and 508 on the far side are increased. fz4, fx2, and fx4 decrease.

When a load Fy is applied to the opposite side of the vehicle body in the axial direction, a reverse phenomenon occurs.
Therefore, the total of loads applied to the load sensors 501, 503, 505, and 507 on the side closer to the flange portion (fz1 + fz3 + fx1 + fx3) and the total load applied to the load sensors 502, 504, 506, and 508 on the far side (fz2 + fz4 + fx2 + fx4) By obtaining the difference, the partial load fy of the load in the axial direction can be measured.
Then, by applying a coefficient k5 (= 1 / 0.04) to this partial load fy, the load Fy in the axial direction applied to the wheel can be obtained (see the above formula 5).

  As described above, according to this example, it is possible to provide a bearing for an automobile wheel and a load measuring method capable of easily measuring a load and a moment.

(Example 2)
In this example, as shown in FIGS. 12 and 13, the displacement sensor 6 is disposed between the inner peripheral portion 31 and the outer peripheral portion 32 in the outer race 3.
That is, the automobile wheel bearing 1 of this example is provided with a displacement sensor 6 instead of the load sensor 5 in the first embodiment.

As shown in FIGS. 12 and 13, the displacement sensor 6 is fixed to the outer peripheral portion 32 of the outer race 3, and its distal end portion is disposed in the through hole 33 between the inner peripheral portion 31 and the outer peripheral portion 32. Yes. And the displacement sensor 6 can measure the displacement between the inner peripheral part 31 and the outer peripheral part 32 by detecting the change of the distance between the front-end | tip part and the outer peripheral surface 311 of the inner peripheral part 31. It is configured to be able to. As the displacement sensor 6, for example, a non-contact type such as an optical type, a contact type, or an eddy current type can be used.
Other configurations are the same as those of the first embodiment.

Next, the load measuring method of this example will be described.
Two displacement sensors 6 are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion 31 vertically above, below, horizontally forward, and rearward with respect to the rotation shaft 21 of the inner race 2. (See FIG. 4). This arrangement pitch L becomes a moment arm of the following moments Mx and Mz.

  As shown in FIG. 12, the displacement hz1 is detected by the displacement sensor 601 on the side close to the flange portion 26 of the two displacement sensors 6 arranged on the upper side, and the displacement hz2 is detected by the displacement sensor 602 on the far side. Further, of the two displacement sensors 6 arranged on the lower side, the displacement hz3 is detected by the displacement sensor 603 on the side closer to the flange portion 26, and the displacement hz4 is detected by the displacement sensor 604 on the far side.

Based on these displacements hz1, hz2, hz3, and hz4, the vertical load Fz and the moment Mx about the longitudinal axis that acted on the wheel are obtained by the following equations 6 and 7, respectively. Here, j1 and j2 are coefficients, which are proportional constants obtained in advance from the relationship between the input load and the displacement.
Fz = j1 {(hz1 + hz2)-(hz3 + hz4)} (Expression 6)
Mx = j2 {(hz1 + hz4) − (hz2 + hz3)} × L (Expression 7)

  Further, as shown in FIG. 14, the displacement hx1 is detected by the displacement sensor 605 on the side closer to the flange portion 26 of the two displacement sensors 6 arranged on the front side, and the displacement hx2 is detected by the displacement sensor 606 on the far side, respectively. The displacement hx3 is detected by the displacement sensor 607 on the side closer to the flange 26 and the displacement hx4 is detected by the displacement sensor 608 on the far side.

Based on these displacements hx1, hx2, hx3, and hx4, the front-rear direction load Fx and the moment Mz about the vertical axis that are applied to the wheels are obtained by the following formulas 8 and 9, respectively. Here, j3 and j4 are coefficients, which are proportional constants obtained in advance from the relationship between the input load and the displacement.
Fx = j3 {(hx1 + hx2) − (hx3 + hx4)} (Equation 8)
Mz = j4 {(hx1 + hx4) − (hx2 + hx3)} × L (Equation 9)

Further, based on the displacements hx1, hx2, hx3, hx4, hz1, hz2, hz3, and hz4, a load Fy in the axial direction applied to the wheel is obtained by the following equation (10). Here, j5 is a coefficient, which is a proportional constant obtained in advance from the relationship between the input load and the displacement.
Fy = j5 {(hz1 + hz3 + hx1 + hx3) − (hz2 + hz4 + hx2 + hx4)} (Equation 10)

Here, the X-axis, Y-axis, and Z-axis directions in FIGS. That is, the horizontal front-rear direction of the vehicle is the X axis, and the front is + (plus). The vertical direction is the Z axis, and the upper direction is +. The axis direction of the axle is defined as the Y axis, and the direction in which the inner race 2 is inserted into the outer race 3 is defined as +.
Further, the displacement sensor 6 outputs a + (plus) output when the space between the inner peripheral portion 31 and the outer peripheral portion 32 is compressed, and outputs a-(minus) output when extended.

That is, as shown in FIG. 12, when a vertical force Fz is input to the axle via the wheel, a compressive load acts on the periphery of the through hole 33 to which the displacement sensors 601 and 602 are attached. 33 becomes narrower. Thereby, displacement outputs hz1 and hz2 of the displacement sensors 601 and 602 become positive. On the other hand, a tensile load acts around the through-hole 33 to which the displacement sensors 603 and 604 are attached, and the displacement outputs hz3 and hz4 of the displacement sensors 603 and 604 become negative.
When the force on the opposite side of the vertical force is applied, the polarity of the displacement output is opposite.
Then, the load Fz can be obtained by applying these displacement outputs hz1, hz2, hz3, and hz4 to the above equation 6.

Further, as shown in FIG. 14, when a longitudinal force Fx is input to the axle via the wheels, a compressive load acts on the periphery of the through hole 33 to which the displacement sensors 605 and 606 are attached. Becomes narrower. As a result, the displacement outputs hx1 and hx2 of the displacement sensors 605 and 606 become positive. On the other hand, a tensile load acts around the through-hole 33 to which the displacement sensors 607 and 608 are attached, and the displacement outputs hx3 and hx4 of the displacement sensors 607 and 608 become negative.
When the force on the opposite side of the horizontal force is applied, the polarity of the displacement output is opposite.
Then, the load Fx can be obtained by applying these displacement outputs hx1, hx2, hx3, hx4 to the above equation 8.

Further, as shown in FIGS. 12 and 14, when a load Fy is applied to the vehicle body side in the axial direction of the axle through the wheels, the outer race 2 is moved from the inner race 2 through the bearing ball row 40 closer to the flange portion 26 to the outer race. The pressing force to the inner peripheral portion 31 of the race 3 increases. Therefore, the displacement outputs hz1, hz3, hx1, and hx3 of the displacement sensors 601 and 603 on the side closer to the flange portion 26 are positive. On the other hand, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange portion 26 decreases. Therefore, the displacement outputs hz2, hz4, hx2, and hx4 of the displacement sensors 602 and 604 far from the flange portion 26 are negative.
When a load is applied to the wheel on the side opposite to the vehicle body in the axial direction, the polarity of the displacement output is reversed.
The load Fy can be obtained by applying these displacement outputs hx1, hx2, hx3, hx4, hz1, hz2, hz3, and hz4 to the above equation 10.

Also, as shown in FIG. 12, when the moment Mx around the longitudinal axis is input to the axle via the wheels, the bearing ball row 40 on the side close to the flange portion 26 of the through-hole 33 to which the displacement sensors 601 and 602 are attached. The pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 is reduced. Therefore, the displacement output hz1 of the displacement sensor 601 is negative.
Then, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 through the bearing ball row 40 on the side far from the flange 26 increases. Therefore, the displacement output hz2 of the displacement sensor 602 is positive.

Further, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 through the bearing ball row 40 on the side close to the flange portion 26 of the through hole 33 to which the displacement sensors 603 and 604 are attached increases. Therefore, the displacement output hz3 of the displacement sensor 603 is positive. Since the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange 26 is reduced, the displacement output hz4 of the displacement sensor 604 becomes negative.
When the moment about the opposite longitudinal axis is applied, the polarity of the displacement output is reversed.
The moment Mx can be obtained by applying these displacement outputs hz1, hz2, hz3, and hz4 to the above equation 7.

Further, as shown in FIG. 14, when the moment Mz around the vertical axis is input to the axle via the wheel, the bearing ball row 40 on the side close to the flange portion 26 of the through-hole 33 to which the displacement sensors 605 and 606 are attached. The pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 increases. Therefore, the displacement output hx1 of the displacement sensor 605 is positive.
Then, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 via the bearing ball row 40 on the side far from the flange 26 decreases. Therefore, the displacement output hx2 of the displacement sensor 606 is negative.

Further, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 through the bearing ball row 40 on the side close to the flange portion 26 of the through hole 33 to which the displacement sensors 607 and 608 are attached is reduced. Therefore, the displacement output hx3 of the displacement sensor 607 is negative.
Then, the pressing force from the inner race 2 to the inner peripheral portion 31 of the outer race 3 through the bearing ball row 40 on the side far from the flange 26 increases. Therefore, the displacement output hx4 of the displacement sensor 608 is positive.
When a moment around the vertical axis on the opposite side is applied, the polarity of the displacement output is opposite.
The moment Mz can be obtained by applying these displacement outputs hx1, hx2, hx3, and hx4 to the above equation 9.

In the case of this example, the displacement between the inner peripheral portion 31 and the outer peripheral portion 32 is detected, and based on this, the load and moment of the wheel acting on the flange portion 26 of the inner race 2 are easily measured. Can do.
In addition, the same effects as those of the first embodiment are obtained.

  In the first and second embodiments, the load sensor or the displacement sensor is used as the strain measurement sensor. However, the strain measurement sensor used in the present invention is not limited to this, and other sensors can be used. It is.

Sectional drawing of the bearing for motor vehicle wheels by the YZ plane in Example 1. FIG. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. Sectional drawing of the bearing for motor vehicle wheels by XY plane in Example 1. FIG. Sectional drawing of the inner race and the outer race in Example 1. FIG. FIG. 3 is an explanatory diagram showing a state of electrical connection of a ceramic sensor in Example 1. FIG. 3 is an explanatory diagram showing a structure of a mechanical quantity sensor material in Example 1. FIG. 3 is a diagram illustrating an output when a load Fx is input as an axial component in the first embodiment. FIG. 3 is a diagram illustrating an output when a load Fy is input as an axial component in the first embodiment. The diagram showing the output at the time of inputting load Fz as an axial direction ingredient in Example 1. FIG. 6 is a diagram illustrating an output when a load Fx is offset input in the first embodiment. The diagram showing the output at the time of carrying out offset input of load Fz in Example 1. FIG. Sectional drawing of the bearing for motor vehicle wheels by the YZ plane in Example 2. FIG. FIG. 13 is a cross-sectional view taken along line B-B in FIG. 12. Sectional drawing of the bearing for motor vehicle wheels by XY plane in Example 2. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Bearing, 2 Inner race, 26 Flange part, 3 Outer race, 31 Inner peripheral part, 32 Outer peripheral part, 40 Bearing ball row | line | column, 5 Load sensor, 6 Displacement sensor

Claims (8)

A bearing for an automobile wheel having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
Two load sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion vertically above and below the rotation axis of the inner race, two by two at an arrangement pitch L1 in the axial direction.
Of the two load sensors arranged on the upper side, the load fz1 is detected by the load sensor on the side closer to the flange part, the load fz2 is detected by the load sensor on the far side, and the two load sensors arranged on the lower side The load fz3 is detected by the load sensor on the side closer to the flange part, and the load fz4 is detected by the load sensor on the far side,
Based on these loads fz1, fz2, fz3, and fz4, the vertical load Fz = k1 {(fz1 + fz2) − (fz3 + fz4)} [k1: coefficient] acting on the wheel, and the moment Mx = k2 about the longitudinal axis {(Fz1 + fz4)-(fz2 + fz3)} × L1 [k2: coefficient] A load measuring method for an automobile wheel, characterized by: A bearing for an automobile wheel having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
Two load sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion in the horizontal front and rear with respect to the rotation axis of the inner race at a pitch L2 in the axial direction.
Of the two load sensors arranged on the front side, the load fx1 is detected by the load sensor closer to the flange portion, the load fx2 is detected by the load sensor on the far side, and the two load sensors arranged on the rear side. The load fx3 is detected by the load sensor on the side close to the flange part, and the load fx4 is detected by the load sensor on the far side,
Based on these loads fx1, fx2, fx3, and fx4, the load Fx = k3 {(fx1 + fx2) − (fx3 + fx4)} [k3: coefficient] acting on the wheel and the moment Mz = k4 about the vertical axis {(Fx1 + fx4)-(fx2 + fx3)} × L2 [k4: coefficient] A load measuring method for an automobile wheel, characterized by: A bearing for an automobile wheel having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a load sensor for measuring a load acting on the outer peripheral part from the inner peripheral part is arranged,
Two load sensors are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion vertically above, below, horizontally forward, and rearward with respect to the rotation axis of the inner race. And
Of the two load sensors arranged on the upper side, the load fz1 is detected by the load sensor on the side closer to the flange part, the load fz2 is detected by the load sensor on the far side, and the two load sensors arranged on the lower side The load fz3 is detected by the load sensor on the side closer to the flange part, and the load fz4 is detected by the load sensor on the far side,
Based on these loads fz1, fz2, fz3, and fz4, the vertical load Fz = k1 {(fz1 + fz2) − (fz3 + fz4)} [k1: coefficient] acting on the wheel, and the moment Mx = k2 about the longitudinal axis {(Fz1 + fz4) − (fz2 + fz3)} × L [k2: coefficient]
Of the two load sensors arranged on the front side, the load fx1 is detected by the load sensor closer to the flange portion, the load fx2 is detected by the load sensor on the far side, and the two load sensors arranged on the rear side. The load fx3 is detected by the load sensor on the side close to the flange part, and the load fx4 is detected by the load sensor on the far side,
Based on these loads fx1, fx2, fx3, and fx4, the load Fx = k3 {(fx1 + fx2) − (fx3 + fx4)} [k3: coefficient] acting on the wheel and the moment Mz = k4 about the vertical axis {(Fx1 + fx4)-(fx2 + fx3)} × L [k4: coefficient] A load measuring method for an automobile wheel, characterized by: 4. The bearing for an automobile wheel according to claim 3, wherein when a load is applied to the vehicle body in the axial direction on the wheel, the bearing from the inner race via the bearing ball row on the side close to the flange portion. The pressing force to the inner peripheral portion of the race increases, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row far from the flange portion decreases,
When a load is applied to the wheel on the side opposite to the vehicle body in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion is And the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is increased,
Based on the loads fx1, fx2, fx3, fx4, fz1, fz2, fz3, and fz4, the axial load Fy = k5 {(fz1 + fx3 + fx1 + fx3) − (fz2 + fxz + fx2 + fx4)} [k5: coefficient] is obtained. A method for measuring a load for an automobile wheel. An inner race having a flange for engaging the hub bolts, bearing for motor vehicle wheel having an outer race fitted around the two rows the inner race via the bearing rows of balls arranged in the axial direction of the inner race In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion vertically above and below the rotation axis of the inner race, with two at a pitch L1 in the axial direction.
Of the two displacement sensors arranged on the upper side, the displacement hz1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hz2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the lower side. The displacement hz3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hz4 is detected by the displacement sensor on the far side,
Based on these displacements hz1, hz2, hz3, and hz4, the vertical load Fz = j1 {(hz1 + hz2) − (hz3 + hz4)} [j1: coefficient] acting on the wheel, and the moment Mx = j2 about the longitudinal axis {(Hz1 + hz4)-(hz2 + hz3)} × L1 [j2: coefficient] A load measuring method for an automobile wheel, characterized by: A bearing for an automobile wheel having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel on the outer peripheral surface of the inner peripheral portion in the horizontal front and rear with respect to the rotation axis of the inner race at a pitch L2 in the axial direction.
Of the two displacement sensors arranged on the front side, the displacement hx1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hx2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the rear side The displacement hx3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hx4 is detected by the displacement sensor on the far side,
Based on these displacements hx1, hx2, hx3, hx4, the longitudinal displacement Fx = j3 {(hx1 + hx2) − (hx3 + hx4)} [j3: coefficient] acting on the wheel and the moment Mz = j4 about the vertical axis {(Hx1 + hx4)-(hx2 + hx3)} × L2 [j4: coefficient] A load measuring method for an automobile wheel, characterized by: A bearing for an automobile wheel having an inner race having a flange portion that engages with a hub bolt, and an outer race that is externally inserted into the inner race via two rows of bearing balls arranged in the axial direction of the inner race. In
The outer race has an inner peripheral portion that contacts each of the bearing ball rows,
The outer peripheral portion is disposed on the outer peripheral side of the inner peripheral portion, and has an outer peripheral portion that elastically holds the inner peripheral portion,
Between the outer peripheral part and the inner peripheral part, a displacement sensor for measuring the displacement between the inner peripheral part and the outer peripheral part is arranged,
Two displacement sensors are arranged in parallel at a pitch L in the axial direction on the outer peripheral surface of the inner peripheral portion vertically above, below, horizontally forward and rearward with respect to the rotation axis of the inner race. And
Of the two displacement sensors arranged on the upper side, the displacement hz1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hz2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the lower side. The displacement hz3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hz4 is detected by the displacement sensor on the far side,
Based on these displacements hz1, hz2, hz3, and hz4, the vertical load Fz = j1 {(hz1 + hz2) − (hz3 + hz4)} [j1: coefficient] acting on the wheel, and the moment Mx = j2 about the longitudinal axis {(Hz1 + hz4) − (hz2 + hz3)} × L [j2: coefficient]
Of the two displacement sensors arranged on the front side, the displacement hx1 is detected by the displacement sensor on the side closer to the flange portion, the displacement hx2 is detected by the displacement sensor on the far side, and of the two displacement sensors arranged on the rear side The displacement hx3 is detected by the displacement sensor on the side closer to the flange part, and the displacement hx4 is detected by the displacement sensor on the far side,
Based on these displacements hx1, hx2, hx3, and hx4, the load Fx = j3 {(hx1 + hx2) − (hx3 + hx4)} [j3: coefficient] acting on the wheel and the moment about the vertical axis Mz = j4 {(Hx1 + hx4)-(hx2 + hx3)} × L [j4: coefficient] A load measuring method for an automobile wheel, characterized by: 8. The bearing for an automobile wheel according to claim 7, wherein when a load is applied to the vehicle body in the axial direction on the wheel, the bearing for the automobile wheel is separated from the inner race via the bearing ball row on the side close to the flange portion. The pressing force to the inner peripheral portion of the race increases, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row far from the flange portion decreases,
When a load is applied to the wheel on the side opposite to the vehicle body in the axial direction, the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side close to the flange portion is And the pressing force from the inner race to the inner peripheral portion of the outer race through the bearing ball row on the side far from the flange portion is increased,
Based on the displacements hx1, hx2, hx3, hx4, hz1, hz2, hz3, hz4, the axial load Fy = j5 {(hz1 + hz3 + hx1 + hx3) − (hz2 + hz4 + hx2 + hx4)} [j5: coefficient] is obtained. A method for measuring a load for an automobile wheel.

Images