JP4957390B2

JP4957390B2 - Method for manufacturing rolling bearing unit with physical quantity measuring device

Info

Publication number: JP4957390B2
Application number: JP2007144550A
Authority: JP
Inventors: 岳史滝澤
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 2007-05-31
Filing date: 2007-05-31
Publication date: 2012-06-20
Anticipated expiration: 2027-05-31
Also published as: JP2008298564A

Description

この発明の対象となる転がり軸受ユニットの物理量測定装置は、転がり軸受ユニットを構成する、外輪等の静止側軌道輪と、ハブ等の回転側軌道輪との間に作用する外力等の物理量を測定する為に利用する。更に、この求めた物理量を、自動車等の車両の走行安定性確保を図る為に利用する。本発明は、この様な転がり軸受ユニットの物理量測定装置の製造コストを低減する事を意図したものである。 A physical quantity measuring device for a rolling bearing unit that is an object of the present invention measures a physical quantity such as an external force that acts between a stationary side race ring such as an outer ring and a rotary side race ring such as a hub that constitutes the rolling bearing unit. Use to do. Further, the obtained physical quantity is used for ensuring the running stability of a vehicle such as an automobile. The present invention is intended to reduce the manufacturing cost of such a physical quantity measuring device for a rolling bearing unit.

例えば自動車の車輪は懸架装置に対し、複列アンギュラ型等の転がり軸受ユニットにより回転自在に支持する。又、自動車の走行安定性を確保する為に、例えばアンチロックブレーキシステム（ＡＢＳ）やトラクションコントロールシステム（ＴＣＳ）、更には、電子制御式ビークルスタビリティコントロールシステム（ＥＳＣ）等の車両用走行安定化装置が使用されている。この様な各種車両用走行安定化装置を制御する為には、車輪の回転速度、車体に加わる各方向の加速度等を表す信号が必要になる。そして、より高度の制御を行なう為には、車輪を介して上記転がり軸受ユニットに加わる荷重（例えばラジアル荷重とアキシアル荷重との一方又は双方）の大きさを知る事が好ましい場合がある。 For example, automobile wheels are rotatably supported by a suspension device by a double-row angular type rolling bearing unit. In order to ensure the running stability of automobiles, for example, anti-lock braking system (ABS), traction control system (TCS), and electronically controlled vehicle stability control system (ESC) etc. The device is in use. In order to control such various vehicle running stabilization devices, signals representing the rotational speed of the wheels, acceleration in each direction applied to the vehicle body, and the like are required. In order to perform higher-level control, it may be preferable to know the magnitude of a load (for example, one or both of a radial load and an axial load) applied to the rolling bearing unit via a wheel.

この様な事情に鑑みて、特許文献１には、特殊なエンコーダを使用して、転がり軸受ユニットに加わる荷重の大きさを測定する発明が記載されている。図３〜５は、この特許文献１に記載された構造と同じ荷重の測定原理を採用している、転がり軸受ユニットの物理量測定装置に関する従来構造の第１例を示している。この従来構造の第１例は、使用時にも回転しない静止側軌道輪である外輪１の内径側に、使用時に車輪を支持固定した状態でこの車輪と共に回転する、回転側軌道輪であるハブ２を、複数個の転動体３、３を介して、回転自在に支持している。これら各転動体３、３には、背面組み合わせ型の接触角と共に、予圧を付与している。尚、図示の例では、上記各転動体３、３として玉を使用しているが、重量が嵩む自動車用の軸受ユニットの場合には、玉に代えて円すいころを使用する場合もある。 In view of such circumstances, Patent Document 1 describes an invention in which a special encoder is used to measure the magnitude of a load applied to a rolling bearing unit. 3 to 5 show a first example of a conventional structure relating to a physical quantity measuring device for a rolling bearing unit, which employs the same load measurement principle as the structure described in Patent Document 1. FIG. The first example of this conventional structure is a hub 2 that is a rotating side race ring that rotates with the wheel while being supported and fixed to the inner diameter side of the outer race 1 that is a stationary side race ring that does not rotate even when used. Is rotatably supported via a plurality of rolling elements 3 and 3. A preload is applied to each of the rolling elements 3 and 3 together with a contact angle of the rear combination type. In the illustrated example, balls are used as the rolling elements 3 and 3. However, in the case of an automobile bearing unit that is heavy in weight, a tapered roller may be used instead of the ball.

又、上記ハブ２の内端部（軸方向に関して「内」とは、自動車への組み付け状態で車両の幅方向中央側を言い、図３、６、７、９の右側。反対に、自動車への組み付け状態で車両の幅方向外側となる、図３、６、７、９の左側を、軸方向に関して「外」と言う。本明細書全体で同じ。）には、円筒状のエンコーダ４を、上記ハブ２と同心に支持固定している。又、上記外輪１の内端開口を塞ぐ有底円筒状のカバー５の内側に、１対のセンサ６ａ、６ｂを包埋したセンサホルダ７を保持すると共に、これら両センサ６ａ、６ｂの検出部を、上記エンコーダ４の被検出面である外周面に近接対向させている。 Also, the inner end of the hub 2 ("inner" in the axial direction means the center side in the width direction of the vehicle when assembled to the automobile, and is the right side of FIGS. 3 , 6, 7 , and 9. On the contrary, to the automobile. The left side of FIGS. 3 , 6, 7 , and 9, which is the outer side in the width direction of the vehicle in the assembled state, is referred to as “outside” with respect to the axial direction. The hub 2 is supported and fixed concentrically. In addition, a sensor holder 7 in which a pair of sensors 6a and 6b are embedded is held inside a bottomed cylindrical cover 5 that closes the inner end opening of the outer ring 1, and a detection unit for both the sensors 6a and 6b. Is placed in close proximity to the outer peripheral surface which is the detected surface of the encoder 4.

このうちのエンコーダ４は、磁性金属板製である。被検出面である、このエンコーダ４の外周面の先半部（軸方向内半部）には、透孔８、８と柱部９、９（図４参照）とを、円周方向に関して交互に且つ等間隔で配置している。これら各透孔８、８と各柱部９、９との境界は、上記被検出面の軸方向（幅方向）に対し同じ角度だけ傾斜させると共に、この軸方向に対する傾斜方向を、上記被検出面の軸方向中間部を境に互いに逆方向としている。従って、上記各透孔８、８と上記各柱部９、９とは、軸方向中間部が円周方向に関して最も突出した「く」字形となっている。そして、上記境界の傾斜方向が互いに異なる、上記被検出面の軸方向外半部と軸方向内半部とのうち、軸方向外半部を第一特性変化部１０とし、軸方向内半部を第二特性変化部１１としている。尚、これら両特性変化部１０、１１を構成する各透孔は、図示の様に互いに連続した状態で形成しても良いし、互いに独立した状態で形成（各透孔を「ハ」字形に配置）しても良い。 Of these, the encoder 4 is made of a magnetic metal plate. Through holes 8 and 8 and column portions 9 and 9 (see FIG. 4 ) are alternately arranged in the circumferential direction in the front half (axially inner half) of the outer circumferential surface of the encoder 4 which is a detected surface . And at equal intervals. The boundaries between the through holes 8 and 8 and the pillars 9 and 9 are inclined by the same angle with respect to the axial direction (width direction) of the detection surface, and the inclination direction with respect to the axial direction is determined by the detection target. The directions are opposite to each other with the axial middle portion of the surface as a boundary. Accordingly, each of the through holes 8 and 8 and each of the column portions 9 and 9 has a "<" shape with an axially intermediate portion protruding most in the circumferential direction. And among the axially outer half part and the axially inner half part of the detected surface, the boundary inclination directions are different from each other, the axially outer half part is defined as the first characteristic changing part 10, and the axially inner half part Is the second characteristic changing unit 11. In addition, each through-hole which comprises both these characteristic change parts 10 and 11 may be formed in the mutually continuous state like illustration, and it forms in the mutually independent state (each through-hole is made into "C" shape. Arrangement).

又、上記カバー５は、ステンレス鋼板等の金属板により全体を有底円筒状に形成しており、上記外輪１の内端部に嵌合固定している。上記両センサ６ａ、６ｂはこの様なカバー５内に、合成樹脂製の上記センサホルダ７を介して保持固定されている。この様な上記両センサ６ａ、６ｂはそれぞれ、永久磁石と、検出部を構成するホールＩＣ、ホール素子、ＭＲ素子、ＧＭＲ素子等の磁気検知素子とから成る。この様な上記両センサ６ａ、６ｂは、上記センサホルダ７の一部（例えば下端部）に包埋された状態で、一方のセンサ６ａの検出部を上記第一特性変化部１０に、他方のセンサ６ｂの検出部を上記第二特性変化部１１に、それぞれ近接対向させている。 The cover 5 is formed in a bottomed cylindrical shape entirely by a metal plate such as a stainless steel plate, and is fitted and fixed to the inner end portion of the outer ring 1. Both the sensors 6a and 6b are held and fixed in such a cover 5 via the sensor holder 7 made of synthetic resin. Each of the sensors 6a and 6b is composed of a permanent magnet and a magnetic detection element such as a Hall IC, a Hall element, an MR element, and a GMR element constituting a detection unit. The two sensors 6a and 6b are embedded in a part (for example, the lower end) of the sensor holder 7, and the detection unit of one sensor 6a is used as the first characteristic changing unit 10 and the other sensor 6a and 6b is embedded in the other. The detection part of the sensor 6b is made to face and oppose the second characteristic change part 11 respectively.

これら両センサ６ａ、６ｂの検出部がこれら両特性変化部１０、１１に対向する位置は、上記エンコーダ４の円周方向に関して同じ位置としている。又、上記外輪１とハブ２との間にアキシアル荷重が作用していない、中立状態で、上記各透孔８、８及び柱部９、９の軸方向中間部で円周方向に関して最も突出した部分（境界の傾斜方向が変化する部分）が、上記両センサ６ａ、６ｂの検出部同士の間の丁度中央位置に存在する様に、各部材の設置位置を規制している。 The positions where the detection units of both the sensors 6 a and 6 b face both the characteristic change units 10 and 11 are the same in the circumferential direction of the encoder 4. Further, in the neutral state where no axial load is applied between the outer ring 1 and the hub 2, the axially intermediate portions of the through holes 8, 8 and the column portions 9, 9 are projected most in the circumferential direction. The position of each member is regulated so that a portion (a portion where the tilt direction of the boundary changes) is located at the center position between the detection portions of the sensors 6a and 6b.

上述の様に構成する転がり軸受ユニットの物理量測定装置の場合、上記外輪１とハブ２との間にアキシアル荷重が作用｛これら外輪１とハブ２とがアキシアル方向（軸方向）に相対変位｝すると、上記両センサ６ａ、６ｂの出力信号が変化する位相がずれる。即ち、上記外輪１とハブ２との間にアキシアル荷重が作用していない、中立状態では、上記両センサ６ａ、６ｂの検出部は、図５の（Ａ）の実線イ、イ上、即ち、上記最も突出した部分から軸方向に同じだけずれた部分に対向する。従って、上記両センサ６ａ、６ｂの出力信号の位相は、同図の（Ｃ）に示す様に一致する。 In the case of the physical quantity measuring device for a rolling bearing unit configured as described above, when an axial load acts between the outer ring 1 and the hub 2 (the outer ring 1 and the hub 2 are relatively displaced in the axial direction (axial direction)). The phase at which the output signals of the sensors 6a and 6b change is shifted. That is, in the neutral state in which an axial load is not applied between the outer ring 1 and the hub 2, the detection portions of the sensors 6a and 6b are on the solid lines A and B in FIG. It faces a portion that is shifted by the same amount in the axial direction from the most protruding portion. Therefore, the phases of the output signals of the sensors 6a and 6b coincide as shown in FIG.

これに対して、上記エンコーダ４を固定したハブ２に、図５の（Ａ）で下向きのアキシアル荷重が作用した場合には、上記両センサ６ａ、６ｂの検出部は、図５の（Ａ）の破線ロ、ロ上、即ち、上記最も突出した部分からの軸方向に関するずれが互いに異なる部分に対向する。この状態では上記両センサ６ａ、６ｂの出力信号の位相は、同図の（Ｂ）に示す様にずれる。更に、上記エンコーダ４を固定したハブ２に、図５の（Ａ）で上向きのアキシアル荷重が作用した場合には、上記両センサ６ａ、６ｂの検出部は、図５の（Ａ）の鎖線ハ、ハ上、即ち、上記最も突出した部分からの軸方向に関するずれが、逆方向に互いに異なる部分に対向する。この状態では上記両センサ６ａ、６ｂの出力信号の位相は、同図の（Ｄ）に示す様に、上記（Ｂ）の場合とは逆方向にずれる。 On the other hand, when a downward axial load is applied to the hub 2 to which the encoder 4 is fixed in FIG. 5A , the detecting portions of the sensors 6a and 6b are shown in FIG. , Opposite to the portions where the deviations in the axial direction from the most protruding portion are different from each other. In this state, the phases of the output signals of the sensors 6a and 6b are shifted as shown in FIG. Further, when an upward axial load is applied to the hub 2 to which the encoder 4 is fixed as shown in FIG. 5A , the detecting portions of both the sensors 6a and 6b are connected to the chain line H shown in FIG. , C, that is, the deviation in the axial direction from the most projecting portion opposes different portions in the opposite direction. In this state, the phases of the output signals of the sensors 6a and 6b are shifted in the opposite direction to the case of (B), as shown in (D) of FIG.

上述の様に、特許文献１に記載される等により従来から知られている転がり軸受ユニットの物理量測定装置の場合には、上記両センサ６ａ、６ｂの出力信号の位相が、上記外輪１とハブ２との間に加わるアキシアル荷重の作用方向（これら外輪１とハブ２との軸方向の相対変位の方向）に応じた向きにずれる。又、このアキシアル荷重（相対変位）により上記両センサ６ａ、６ｂの出力信号の位相がずれる程度は、このアキシアル荷重（相対変位）が大きくなる程大きくなる。従って、上記両センサ６ａ、６ｂの出力信号の位相ずれの有無、ずれが存在する場合にはその向き及び大きさに基づいて、それぞれが上記外輪１と上記ハブ２との間の物理量である、上記軸方向の相対変位の向き及び大きさ、並びに、上記アキシアル荷重の作用方向及び大きさを求められる。 As described above, in the case of a conventionally known physical quantity measuring device for a rolling bearing unit as described in Patent Document 1, the phases of the output signals of both the sensors 6a and 6b are the same as those of the outer ring 1 and the hub. 2 is shifted in a direction corresponding to the direction of action of the axial load applied between the outer ring 1 and the axial direction of the outer ring 1 and the hub 2. Further, the degree of the phase shift of the output signals of the sensors 6a and 6b due to the axial load (relative displacement) increases as the axial load (relative displacement) increases. Therefore, based on the presence and absence of the phase shift of the output signals of the sensors 6a and 6b and the direction and magnitude of the shift, each is a physical quantity between the outer ring 1 and the hub 2. The direction and magnitude of the relative displacement in the axial direction, and the direction and magnitude of the axial load are obtained.

尚、この様な、物理量の一種であるアキシアル荷重を算出する処理は、図示しない演算器により行なう。この為、この演算器のメモリ中に、予め理論計算や実験により調べておいた、上記両センサ６ａ、６ｂの出力信号同士の間の位相の相違である位相差（出力信号に応じて変化する値）と、上記軸方向の相対変位又はアキシアル荷重との関係を、関係式やマップの型式で記憶させておく。尚、この関係としては、上記位相差が変化する程度と上記アキシアル荷重の大きさが変化する程度との関係であるゲイン、及び、このアキシアル荷重の値がゼロである場合の位相差の値である零点がある。 Note that such processing for calculating an axial load, which is a kind of physical quantity, is performed by a calculator (not shown). For this reason, in the memory of this computing unit, a phase difference (which changes according to the output signal), which is a phase difference between the output signals of the two sensors 6a and 6b, which has been examined in advance by theoretical calculation or experiment. Value) and the relative displacement in the axial direction or the axial load is stored as a relational expression or a map type. This relationship includes the gain that is the relationship between the degree of change of the phase difference and the amount of change of the axial load, and the value of the phase difference when the value of the axial load is zero. There is a zero.

上述した従来構造の第１例の場合には、前記エンコーダ４の被検出面に前記透孔８、８と柱部９、９とを交互に配置して、この被検出面の特性を交互に、且つ、等間隔で変化させている。これに対して、図６に示す様に、被検出面である外周面にＳ極とＮ極とを交互に配置した、永久磁石製のエンコーダ４ａを備えた転がり軸受ユニットの物理量測定装置も、特許文献２等に記載されて、従来から知られている。上記図６に示した転がり軸受ユニットの物理量測定装置の基本的構造及び作用は、前述した図３〜５に示した従来構造の第１例の場合と同様である。但し、上記図６に示した従来構造の第２例の場合には、エンコーダ４ａ側に永久磁石を設けている為、センサ６ａ、６ｂ側には、原則的には磁気検知素子を設ければ良く、永久磁石は不要である。又、図６に示した構造の場合には、ハブ２ａを構成するハブ本体と内輪との結合を、図３に示したナットに代えて、ハブ本体の軸方向内端部に形成したかしめ部により行なっている。但し、この様な構造に就いては、従来から周知であり、本発明の要旨とも関係しない。 In the case of the above-described first example of the conventional structure, the through holes 8 and 8 and the column portions 9 and 9 are alternately arranged on the detection surface of the encoder 4, and the characteristics of the detection surface are alternately set. And it is changed at equal intervals. On the other hand, as shown in FIG. 6 , a physical quantity measuring device for a rolling bearing unit having an encoder 4a made of a permanent magnet, in which S poles and N poles are alternately arranged on the outer peripheral surface which is a detected surface, It is described in Patent Document 2 and the like and has been conventionally known. The basic structure and operation of the physical quantity measuring device of the rolling bearing unit shown in FIG. 6 are the same as those of the first example of the conventional structure shown in FIGS. 3-5 described above. However, in the case of the second example of the conventional structure shown in FIG. 6 , since a permanent magnet is provided on the encoder 4a side, in principle, if a magnetic sensing element is provided on the sensor 6a, 6b side. Good, no permanent magnet is needed. Further, in the case of the structure shown in FIG. 6 , a caulking portion formed on the inner end in the axial direction of the hub main body instead of the nut shown in FIG. It is done by. However, such a structure has been conventionally known and is not related to the gist of the present invention.

更に、特許文献３には、図７〜１０に示す様な転がり軸受ユニットの物理量測定装置が記載されている。先ず、図７〜８に示した従来構造の第３例の場合、ハブ２の内端部に外嵌固定した、磁性金属板製で円筒状のエンコーダ４ｂの先半部に、スリット状の透孔８ａ、８ａと柱部９ａ、９ａ（図８参照）とを、円周方向に関して交互に且つ等間隔で配置している。これら各透孔８ａ、８ａと各柱部９ａ、９ａとの境界はそれぞれ、上記エンコーダ４ｂの軸方向に対し同方向に同じ角度だけ傾斜した、直線状である。又、外輪１の内端部にカバー５及びセンサホルダ７を介して支持固定した１対のセンサ６ａ、６ｂの検出部を、被検出面である、上記エンコーダ４ｂの先半部外周面の上下２個所位置（円周方向の位相が互いに１８０度異なる部分）に近接対向させている。 Further, Patent Document 3 describes a physical quantity measuring device for a rolling bearing unit as shown in FIGS . First, in the case of the third example of the conventional structure shown in FIGS. 7 to 8 , a slit-shaped transparent member is formed on the tip half of a cylindrical encoder 4 b made of a magnetic metal plate and fitted and fixed to the inner end of the hub 2. The holes 8a, 8a and the column portions 9a, 9a (see FIG. 8 ) are alternately arranged at equal intervals in the circumferential direction. The boundaries between the through holes 8a and 8a and the pillars 9a and 9a are linear shapes that are inclined by the same angle in the same direction with respect to the axial direction of the encoder 4b. Further, the detection portions of the pair of sensors 6a and 6b supported and fixed to the inner end portion of the outer ring 1 via the cover 5 and the sensor holder 7 are arranged on the upper and lower sides of the outer peripheral surface of the front half of the encoder 4b, which is the detection surface. The two positions (the portions in which the circumferential phases are different from each other by 180 degrees) are placed close to each other.

自動車の車輪支持用転がり軸受ユニットの場合、上記外輪１と上記ハブ２との間に加わるアキシアル荷重は、このハブ２に結合固定した車輪を構成するタイヤの外周面と路面との接地面から入力される。この接地面は、上記外輪１及び上記ハブ２の回転中心よりも径方向外方に存在する為、上記アキシアル荷重はこれら外輪１とハブ２との間に、純アキシアル荷重としてではなく、これら外輪１及びハブ２の中心軸と上記接地面の中心とを含む（鉛直方向の）仮想平面内での、モーメントを伴って加わる。この様なモーメントが上記外輪１と上記ハブ２との間に加わると、このハブ２の中心軸がこの外輪１の中心軸に対して傾く。これに伴い、上記エンコーダ４ｂの上端部が軸方向に関して何れかの方向に、同じく下端部がこれと逆方向に、それぞれ変位する。この結果、上記エンコーダ４ｂの外周面の上下両端部にそれぞれの検出部を近接対向させた、上記両センサ６ａ、６ｂの出力信号の位相が、それぞれ中立位置に対して、逆方向にずれる。従って、これら両センサ６ａ、６ｂの出力信号の位相のずれの向き及び大きさに基づいて、上記アキシアル荷重の向き及び大きさを求められる。 In the case of a rolling bearing unit for supporting a wheel of an automobile, an axial load applied between the outer ring 1 and the hub 2 is input from a ground contact surface between a tire outer peripheral surface and a road surface constituting a wheel coupled and fixed to the hub 2. Is done. Since this ground contact surface exists radially outward from the rotation center of the outer ring 1 and the hub 2, the axial load is not between the outer ring 1 and the hub 2 but as a pure axial load. 1 and the center axis of the hub 2 and the center of the grounding surface are applied with a moment in a virtual plane (in the vertical direction). When such a moment is applied between the outer ring 1 and the hub 2, the central axis of the hub 2 is inclined with respect to the central axis of the outer ring 1. Accordingly, the upper end of the encoder 4b is displaced in any direction with respect to the axial direction, and the lower end is similarly displaced in the opposite direction. As a result, the phases of the output signals of the sensors 6a and 6b, in which the detection units are placed close to and opposed to the upper and lower ends of the outer peripheral surface of the encoder 4b, are shifted in the opposite directions with respect to the neutral position. Therefore, the direction and magnitude of the axial load can be obtained based on the direction and magnitude of the phase shift between the output signals of both the sensors 6a and 6b.

更に、図９〜１０に示した、従来構造の第４例の場合、ハブ２の内端部に外嵌固定した、磁性金属板製で円筒状のエンコーダ４ｃの先半部に、透孔８ｂ、８ｂと柱部９ｂ、９ｂ（図１０参照）とを、円周方向に関して交互に且つ等間隔で配置している。これら各透孔８ｂ、８ｂはそれぞれ、径方向から見た形状を台形として、それぞれの円周方向に関する幅寸法を、軸方向に関して漸次変化させている。又、外輪１の内端部にカバー５及びセンサホルダ７を介して支持固定した１個のセンサ６の検出部を、被検出面である、上記エンコーダ４ｃの先半部外周面に近接対向させている。この様に構成する従来構造の第４例の場合、アキシアル荷重に基づいて上記外輪１と上記ハブ２とが軸方向に相対変位すると、上記センサ６の出力信号のデューティ比（高電位継続時間／１周期）が変化する。従って、このデューティ比に基づいて、上記相対変位の大きさ、更には上記アキシアル荷重の大きさを求められる。 Further, in the case of the fourth example of the conventional structure shown in FIGS. 9 to 10 , a through hole 8 b is formed in the front half of a cylindrical encoder 4 c made of a magnetic metal plate and fitted and fixed to the inner end of the hub 2. 8b and column portions 9b and 9b (see FIG. 10 ) are alternately arranged at equal intervals in the circumferential direction. Each of these through holes 8b, 8b has a trapezoidal shape when viewed from the radial direction, and gradually changes the width dimension in the circumferential direction with respect to the axial direction. Further, the detection portion of one sensor 6 supported and fixed to the inner end portion of the outer ring 1 via the cover 5 and the sensor holder 7 is brought close to and opposed to the outer peripheral surface of the front half of the encoder 4c, which is the detected surface. ing. In the fourth example of the conventional structure configured as described above, when the outer ring 1 and the hub 2 are relatively displaced in the axial direction based on the axial load, the duty ratio of the output signal of the sensor 6 (high potential duration / 1 cycle) changes. Therefore, the magnitude of the relative displacement and further the magnitude of the axial load can be obtained based on the duty ratio.

尚、前述の図３〜６に示した従来構造の第１〜２例の場合には、それぞれの検出部を第一、第二両特性変化部１０、１１に対向させた１対のセンサ６ａ、６ｂから成るセンサ組を、１組だけ設けている。これに対し、図示は省略するが、特許文献３及び特願２００６−３４５８４９には、それぞれが１対のセンサから成るセンサ組を複数組設ける事で、多方向の変位或は外力を求められる構造が記載されている。 In the case of the first and second examples of the conventional structure shown in FIGS. 3 to 6 described above, a pair of sensors 6a in which the respective detection units are opposed to the first and second characteristic change units 10 and 11, respectively. , 6b, only one set is provided. In contrast, although not shown in the drawings, Patent Document 3 and Japanese Patent Application No. 2006-345849 each have a structure in which a plurality of sensor sets each including a pair of sensors are provided so that multidirectional displacement or external force can be obtained. Is described.

上述の様な従来から知られている物理量測定装置付転がり軸受ユニットで、外輪１等の静止側軌道輪と、ハブ２等の回転側軌道輪との間に作用する、アキシアル荷重の如き外力等の物理量を測定する為には、センサの出力信号とこの物理量との関係、即ち、これら出力信号と物理量との関係に関する零点及びゲインを知っておく必要がある。例えば、図３〜８に示した従来構造の第１〜３例で、１対のセンサ６ａ、６ｂの位相差比（＝これら両センサ６ａ、６ｂの出力信号同士の位相差／１周期）とアキシアル荷重との関係に関しては、このアキシアル荷重がゼロである場合の位相差比（零点）と、このアキシアル荷重が単位量変化した場合に於けるこの位相差比の変化量（ゲイン）を知っておく必要がある。又、図９〜１０に示した従来構造の第４例に関しても、アキシアル荷重がゼロである場合のデューティ比（零点）と、このアキシアル荷重が単位量変化した場合に於けるこのデューティ比の変化量（ゲイン）を知っておく必要がある。 The above-described conventionally known rolling bearing unit with a physical quantity measuring device, such as an external force such as an axial load, which acts between a stationary raceway such as the outer ring 1 and a rotary raceway such as the hub 2. In order to measure the physical quantity, it is necessary to know the relationship between the sensor output signal and the physical quantity, that is, the zero point and gain related to the relation between the output signal and the physical quantity. For example, in the first to third examples of the conventional structure shown in FIGS. 3 to 8 , the phase difference ratio of the pair of sensors 6a and 6b (= phase difference between output signals of both the sensors 6a and 6b / 1 period) Regarding the relationship with the axial load, know the phase difference ratio (zero point) when this axial load is zero, and the change amount (gain) of this phase difference ratio when this axial load changes by a unit amount. It is necessary to keep. Also, with respect to the fourth example of the conventional structure shown in FIGS. 9 to 10, the duty ratio (zero point) when the axial load is zero and the change of the duty ratio when the axial load changes by a unit amount. You need to know the amount (gain).

この為従来は、特許文献４に記載されている様に、組立完了後の物理量測定装置付転がり軸受ユニットを構成するハブを回転させつつ、このハブと外輪との間に既知のアキシアル荷重を負荷して、センサの出力信号を測定し、これらアキシアル荷重と出力信号との関係（零点及びゲイン）を求める事が考えられている。求めた零点及びゲインは、無線ＩＣタグ等を介して、上記アキシアル荷重を求める為の演算器のメモリ中に記憶させる。この様な、零点及びゲインを求める為の従来方法の場合には、これら零点及びゲインを精度良く求められる代わりに、製造装置のコストが嵩む。この理由は、組立完了後の物理量測定装置付転がり軸受ユニットを構成するハブを回転させつつ、このハブと外輪との間に既知のアキシアル荷重を負荷する装置が必要になる為である。又、物理量測定装置付転がり軸受ユニットの製造工場でこの物理量測定装置付転がり軸受ユニットの組立を完了した後、出荷以前に上記零点及びゲインを求める為の作業が入り込む為、この物理量測定装置付転がり軸受ユニットの製造作業の段取りが悪化する。これらにより、物理量測定装置付転がり軸受ユニットの製造コストが嵩む。
尚、本発明に関連する刊行物として、特許文献５〜８及び非特許文献１がある。 Therefore, conventionally, as described in Patent Document 4, a known axial load is applied between the hub and the outer ring while rotating the hub constituting the rolling bearing unit with a physical quantity measuring device after assembly is completed. Then, it is considered to measure the output signal of the sensor and obtain the relationship (zero point and gain) between these axial loads and the output signal. The obtained zero and gain are stored in the memory of the arithmetic unit for obtaining the axial load via a wireless IC tag or the like. In the case of such a conventional method for obtaining the zero and gain, the cost of the manufacturing apparatus increases instead of obtaining the zero and gain with high accuracy. This is because it is necessary to provide a device that applies a known axial load between the hub and the outer ring while rotating the hub constituting the rolling bearing unit with a physical quantity measuring device after assembly is completed. In addition, after completing the assembly of the rolling bearing unit with a physical quantity measuring device at the manufacturing factory of the rolling bearing unit with a physical quantity measuring device, the work for obtaining the zero point and the gain before entering the product enters the rolling bearing unit with the physical quantity measuring device. The setup for manufacturing the bearing unit deteriorates. These increase the manufacturing cost of the rolling bearing unit with a physical quantity measuring device.
As publications related to the present invention, there are Patent Literatures 5 to 8 and Non-Patent Literature 1.

特開２００６−１１３０１７号公報JP 2006-1113017 A 特開２００６−３１７４２０号公報JP 2006-317420 A 特開２００７−９３５８０号公報JP 2007-93580 A 特開２００７−１９４６７３号公報JP 2007-194673 A 特開平５−１０８３５号公報Japanese Patent Laid-Open No. 5-10835 特開平６−３４４２３３号公報JP-A-6-344233 特開２０００−７４７８８号公報JP 2000-74788 A 特開２００２−２６３９６９号公報JP 2002-263969 A ＮＳＫレポート、日本精工株式会社、１９８９年１１月、ｐ．５９−６６NSK Report, NSK Ltd., November 1989, p. 59-66

本発明は、上述の様な事情に鑑み、既知のアキシアル荷重を負荷する装置を不要にして製造装置のコストを抑えると共に、段取りを簡略化して、物理量測定装置付転がり軸受ユニットの製造コストを抑えられる製造方法を実現すべく発明したものである。 In view of the circumstances as described above, the present invention eliminates the need for a device that applies a known axial load, thereby reducing the cost of the manufacturing device, simplifying the setup, and reducing the manufacturing cost of the rolling bearing unit with a physical quantity measuring device. The present invention has been invented to realize a manufacturing method.

本発明の製造方法の対象となる物理量測定装置付転がり軸受ユニットは、転がり軸受ユニットと物理量測定装置とを備える。
このうちの転がり軸受ユニットは、静止側軌道輪と、回転側軌道輪と、複数個の転動体とを備える。そして、このうちの静止側軌道輪は、静止側周面に複列の静止側軌道を有し、使用時にも回転しない。又、上記回転側軌道輪は、この静止側周面と径方向に対向する回転側周面に複列の回転側軌道を有し、使用時に回転する。更に、上記各転動体は、これら両列の回転側軌道と上記両列の静止側軌道との間に、両列毎に複数個ずつ、それぞれ予圧を付与された状態で転動自在に設けられている。 A rolling bearing unit with a physical quantity measuring device, which is an object of the manufacturing method of the present invention, includes a rolling bearing unit and a physical quantity measuring device.
Of these, the rolling bearing unit includes a stationary-side bearing ring, a rotating-side bearing ring, and a plurality of rolling elements. Of these, the stationary-side raceway has a double-row stationary-side raceway on the stationary-side peripheral surface, and does not rotate during use. The rotation-side raceway has a double-row rotation-side raceway on the rotation-side circumferential surface facing the stationary side circumferential surface in the radial direction, and rotates when in use. Further, each of the rolling elements is provided between the rotation-side tracks of both rows and the stationary-side tracks of both rows so as to be freely rollable in a state where a preload is applied to each row. ing.

一方、上記物理量測定装置は、エンコーダと、少なくとも１個のセンサと、演算器とを備える。
このうちのエンコーダは、上記回転側軌道輪若しくはこの回転側軌道輪と同心に結合固定された回転部材の一部にこの回転側軌道輪と同心に支持固定されたもので、この回転側軌道輪と同心の被検出面を備える。そして、この被検出面の特性を円周方向に関して交互に変化させている。
又、上記センサは、検出部を上記エンコーダの被検出面に対向させた状態で、回転しない部分に支持されていて、上記被検出面の特性変化に対応して出力信号を変化させる。
更に、上記演算器は、上記センサの出力信号に基づいて、上記静止側軌道輪と上記回転側軌道輪との間の相対変位と、これら静止側軌道輪と回転側軌道輪との間に作用する外力とのうちの、少なくとも一方の物理量を算出する機能を有する。 On the other hand, the physical quantity measuring device includes an encoder, at least one sensor, and a calculator.
Of these, the encoder is supported and fixed concentrically with the rotation-side raceway by a part of the rotation-side raceway or a rotation member coupled and fixed concentrically with the rotation-side raceway. And a concentric surface to be detected. The characteristics of the detected surface are alternately changed in the circumferential direction.
The sensor is supported by a non-rotating portion in a state where the detection unit faces the detection surface of the encoder, and changes an output signal in response to a change in characteristics of the detection surface.
Further, the computing unit acts on the relative displacement between the stationary side raceway and the rotation side raceway and between the stationary side raceway and the rotation side raceway based on the output signal of the sensor. It has a function of calculating at least one physical quantity of the external force.

この様な物理量測定装置付転がり軸受ユニットを造る為に、本発明の製造方法の場合には、上記演算器が上記センサの出力信号に基づいて上記物理量を算出する際に使用する、この出力信号若しくはこの出力信号に応じて変化する値が変化する程度と、この物理量の大きさが変化する程度との関係であるゲインに影響する、上記転がり軸受ユニットに関する特性を、この転がり軸受ユニット単体の状態で測定して（物理量測定装置を使用する事なく測定するとの意味で、測定作業時に物理量測定装置と転がり軸受ユニットとが組み合わされている事は差し支えない）記録する。そして、この記録を、当該転がり軸受ユニットと組み合わされた、上記物理量測定装置を構成する演算器のメモリ中に記録する。 In order to manufacture such a rolling bearing unit with a physical quantity measuring device, in the case of the manufacturing method of the present invention , this output signal is used when the arithmetic unit calculates the physical quantity based on the output signal of the sensor. Alternatively, the characteristics of the rolling bearing unit that affect the gain, which is the relationship between the degree of change in accordance with the output signal and the degree of change in the physical quantity, can be expressed as the state of the rolling bearing unit alone. (Recording means that the physical quantity measuring device is used without using the physical quantity measuring device, and the physical quantity measuring device and the rolling bearing unit may be combined during the measurement work) and record. And this record is recorded in the memory of the arithmetic unit which comprises the said physical quantity measuring apparatus combined with the said rolling bearing unit.

又、本発明の場合には、上記ゲインに影響する、転がり軸受ユニットに関する特性を、この転がり軸受ユニットの剛性とする。そして、この剛性又はこの剛性に関連するデータを演算器のメモリ中に記録する事で、この演算器が使用するゲインを、上記転がり軸受ユニットの剛性に対応したものとする。
或いは、上記ゲインに影響する、転がり軸受ユニットに関する特性を、この転がり軸受ユニットの予圧とする。そして、この予圧又はこの予圧に関連するデータを演算器のメモリ中に記録する事で、この演算器が使用するゲインを、上記転がり軸受ユニットの予圧に対応したものとする。
尚、上記転がり軸受ユニットの剛性又は予圧は、この転がり軸受ユニット単体の状態で、この転がり軸受ユニットに振動を付与してこの転がり軸受ユニットの共振周波数を求める事により測定する。 In the case of the present invention, the characteristic of the rolling bearing unit that affects the gain is the rigidity of the rolling bearing unit. Then, by recording this rigidity or data related to this rigidity in the memory of the calculator, the gain used by this calculator corresponds to the rigidity of the rolling bearing unit.
Alternatively, affects the gain, the characteristics related to the rolling bearing unit, the preload of the rolling bearing unit. Then, by recording this preload or data related to this preload in the memory of the calculator, the gain used by this calculator corresponds to the preload of the rolling bearing unit .
The rigidity or preload of the rolling bearing unit is measured by applying vibration to the rolling bearing unit and obtaining the resonance frequency of the rolling bearing unit in the state of the rolling bearing unit alone.

上述の様な本発明を実施する場合に、好ましくは、請求項２に記載した発明の様に、転がり軸受ユニットと物理量測定装置とを組み合わせた後、静止側軌道輪と回転側軌道輪との間に運転状態で変動する外力が加わらず、これら両軌道輪同士が中立位置に存在する状態でセンサの出力信号を演算器に取り込む。そして、この状態でのセンサの出力信号を、物理量が中立状態に存在する場合に於けるこの出力信号の値である零点として、演算器のメモリ中に記録する。 When carrying out the present invention as described above , preferably, after combining the rolling bearing unit and the physical quantity measuring device as in the invention described in claim 2 , the stationary-side bearing ring and the rotating-side bearing ring are The sensor output signal is taken into the arithmetic unit in the state where the external force fluctuating in the driving state is not applied and the two race wheels are in the neutral position. Then, the output signal of the sensor in this state is recorded in the memory of the arithmetic unit as a zero point which is the value of this output signal when the physical quantity is in a neutral state.

又、好ましくは、請求項３に記載した発明の様に、転がり軸受ユニットを、自動車の懸架装置に車輪を回転自在に支持する為の車輪支持用転がり軸受ユニットとする。そして、静止側軌道輪を、使用時に懸架装置に支持固定される外輪とし、回転側軌道輪を、車輪を結合固定した状態でこの車輪と共に回転するハブとする。
この様な請求項３に記載した発明を実施する場合に、好ましくは、請求項４に記載した発明の様に、上記転がり軸受ユニットと物理量測定装置とを組み合わせると共に、上記外輪を懸架装置に支持固定し、ハブに車輪を結合固定した後、平坦面上で自動車の重量をこの車輪により支えた状態で、上記外輪と上記ハブとの間に、この自動車の走行状態で変動する外力が加わらず、これら外輪とハブとが中立位置に存在する状態で、センサの出力信号を演算器に取り込む。そして、この状態でのセンサの出力信号を、物理量が中立状態に存在する場合に於けるこの出力信号の値である零点として、演算器のメモリ中に記録する。 Further, preferably, as in the invention described in claim 3, the rolling bearing unit is a wheel supporting rolling bearing unit for rotatably supporting the wheel suspension system of a motor vehicle. The stationary raceway is an outer ring that is supported and fixed to the suspension device during use, and the rotation-side raceway is a hub that rotates together with the wheel while the wheels are coupled and fixed.
When carrying out the invention described in claim 3 , it is preferable that the rolling bearing unit and the physical quantity measuring device are combined and the outer ring is supported by the suspension device as in the invention described in claim 4. After fixing and fixing the wheel to the hub, with the weight of the vehicle supported by the wheel on a flat surface, an external force that varies depending on the running state of the vehicle is not applied between the outer wheel and the hub. In the state where the outer ring and the hub are in the neutral position, the output signal of the sensor is taken into the arithmetic unit. Then, the output signal of the sensor in this state is recorded in the memory of the arithmetic unit as a zero point which is the value of this output signal when the physical quantity is in a neutral state.

上述の様に構成する本発明によれば、既知のアキシアル荷重を負荷する装置を不要にして製造装置のコストを抑えると共に、段取りを簡略化して、物理量測定装置付転がり軸受ユニットの製造コストを抑えられる。
即ち、転がり軸受ユニットの剛性、或いは、この転がり軸受ユニットに付与されている予圧は、この転がり軸受ユニットを構成する静止側軌道輪と回転側軌道輪との相対変位しにくさに影響する。具体的には、剛性が高い程、予圧が大きい程、外力が加わった状態での、上記静止側軌道輪と上記回転側軌道輪との相対変位量が少なくなる。逆に言えば、剛性が低い程、予圧が小さい程、外力が加わった状態での、上記静止側軌道輪と上記回転側軌道輪との相対変位量が多くなる。そして、同種の（型番が同じである）転がり軸受ユニットの場合、剛性或いは予圧が多少（実用上問題なく、転がり軸受ユニットとしての品質検査により合格とされる範囲で）変化しても、剛性或いは予圧と上記相対変位量との間には比例関係に近い、明確な関係が存在する。そして、この関係は、予め実験或いは解析により知る事ができる。 According to the present invention configured as described above, a device for applying a known axial load is not required, the cost of the manufacturing device is reduced, the setup is simplified, and the manufacturing cost of the rolling bearing unit with a physical quantity measuring device is reduced. It is done.
That is, the rigidity of the rolling bearing unit or the preload applied to the rolling bearing unit affects the difficulty of relative displacement between the stationary bearing ring and the rotating bearing ring constituting the rolling bearing unit. Specifically, the higher the rigidity and the greater the preload, the smaller the relative displacement between the stationary side raceway and the rotation side raceway when an external force is applied. In other words, the lower the rigidity and the smaller the preload, the greater the relative displacement between the stationary side raceway and the rotation side raceway when an external force is applied. In the case of rolling bearing units of the same type (with the same model number), even if the rigidity or preload changes to some extent (with no problem in practice and passed by quality inspection as a rolling bearing unit), There is a clear relationship close to a proportional relationship between the preload and the relative displacement. And this relationship can be known beforehand by experiment or analysis.

そこで、上記剛性或いは予圧を、転がり軸受ユニット単体で測定して、これら剛性或いは予圧、或いはこれら剛性或いは予圧に関連するデータを保存し、演算器のメモリ中に記録すれば、この演算器に、センサの出力信号若しくはこの出力信号に応じて変化する値が変化する程度と、物理量の大きさが変化する程度との関係である、ゲインを入力できる。そして、このゲインにより、静止側軌道輪と回転側軌道輪との間の物理量の変化の程度を求められる。 Therefore, if the rigidity or preload is measured by a single rolling bearing unit, the rigidity or preload, or data related to the rigidity or preload is stored and recorded in the memory of the calculator, A gain, which is a relationship between the degree to which the sensor output signal or a value that changes in accordance with the output signal changes, and the degree to which the physical quantity changes can be input. Then, the degree of change in the physical quantity between the stationary side raceway and the rotation side raceway can be obtained from this gain .

本発明の実施の形態の１例に就いて、図１〜２により説明する。尚、本例は、前述の図３〜８に示す様に、１対のセンサ６ａ、６ｂの出力信号同士の間に存在する位相差比により、外輪１とハブ２との間に作用するアキシアル荷重を求める構造を造る場合に就いて示している。この様な本例の物理量測定装置付転がり軸受ユニットの製造方法の場合には、図１のフローチャートに示す様に、先ず、ステップ１（Ｓ１）で、転がり軸受ユニットの構成各部材（外輪１、ハブ２、転動体３、３等。図３、６、７参照）を組み立てた後、ステップ２（Ｓ２）で、ナットを締め付けたり（図３、７の構造の場合）、或いはかしめ部を形成する（図６の構造の場合）事により、各転動体３、３に予圧を付与する。この状態で、上記転がり軸受ユニットとしては完成する。 An example of an embodiment of the present invention will be described with reference to FIGS. In this example, as shown in FIGS. 3 to 8 described above, an axial acting between the outer ring 1 and the hub 2 by the phase difference ratio existing between the output signals of the pair of sensors 6a and 6b. It shows a case where a structure for obtaining a load is made. In the case of such a manufacturing method of a rolling bearing unit with a physical quantity measuring device of this example, as shown in the flowchart of FIG. 1, first, in step 1 (S1), each component (outer ring 1, hub 2, rolling elements 3, 3, etc.. after assembling the see FIG 3, 6, 7), at step 2 (S2), when the structure of or tightening the nut (3, 7), or forming the crimped portion By doing this (in the case of the structure of FIG. 6 ), a preload is applied to each rolling element 3, 3. In this state, the rolling bearing unit is completed.

そして、この様にして上記各転動体３、３に予圧を付与しつつ、上記転がり軸受ユニットを組み立てた後、ステップ３（Ｓ３）で、この転がり軸受ユニットの剛性を求める。この剛性を求める作業は、特許文献５〜７に記載される等により、転がり軸受の技術分野で周知の様に、上記転がり軸受ユニットに振動を付与して、この転がり軸受ユニットの共振周波数を求める事により行なう。この様にして求めた共振周波数に基づき、この転がり軸受ユニットに付与した予圧が求められる。この転がり軸受ユニットに付与した予圧はこの転がり軸受ユニットの剛性に大きく影響し、予圧が大きい程剛性も大きくなる。そして、この剛性が大きい程、外力に基づく、上記外輪１と上記ハブ２との相対変位量が少なくなる。要するに、図２に示す様に、上記転がり軸受ユニットに付与した予圧が大きい程、アキシアル荷重に基づく上記外輪１と上記ハブ２との相対変位量が少なくなり、上記位相差比も小さくなる。この事から、上記転がり軸受ユニットの剛性或いは予圧に関する情報を、上記アキシアル荷重を求める為のゲインとして利用できる事が分かる。 Then, after assembling the rolling bearing unit while applying a preload to the rolling elements 3 and 3 in this manner, the rigidity of the rolling bearing unit is obtained in step 3 (S3). The work for obtaining the rigidity is described in Patent Documents 5 to 7 and the like, as is well known in the technical field of rolling bearings, vibration is applied to the rolling bearing unit to obtain the resonance frequency of the rolling bearing unit. By doing things. Based on the resonance frequency thus obtained, the preload applied to the rolling bearing unit is obtained. The preload applied to the rolling bearing unit greatly affects the rigidity of the rolling bearing unit, and the rigidity increases as the preload increases. As the rigidity increases, the amount of relative displacement between the outer ring 1 and the hub 2 based on external force decreases. In short, as shown in FIG. 2, the larger the preload applied to the rolling bearing unit, the smaller the relative displacement between the outer ring 1 and the hub 2 based on the axial load, and the smaller the phase difference ratio. From this, it can be seen that the information on the rigidity or preload of the rolling bearing unit can be used as a gain for obtaining the axial load.

即ち、上記転がり軸受ユニットに付与した予圧が大きい場合は、上記転がり軸受ユニットの剛性が高くなる為、上記アキシアル荷重が作用した状態で前記両センサ６ａ、６ｂの出力信号同士の間に生じる位相差比の変動が小さくなる。これに対して、上記予圧が小さくなるに従って上記剛性が低くなり、上記アキシアル荷重に基づく上記位相差比の変動が大きくなる。従って、このアキシアル荷重を実用的な精度で求める為には、上記予圧若しくはこの予圧に基づいて変化する剛性を知る必要がある。この剛性が異なると、上記アキシアル荷重と上記位相差比との関係であるゲインが異なり、このアキシアル荷重を十分な精度で求められない可能性を生じる。 That is, when the preload applied to the rolling bearing unit is large, the rigidity of the rolling bearing unit is increased. Therefore, the phase difference generated between the output signals of the sensors 6a and 6b in the state where the axial load is applied. The variation of the ratio is reduced. On the other hand, as the preload decreases, the rigidity decreases, and the variation in the phase difference ratio based on the axial load increases. Therefore, in order to obtain the axial load with practical accuracy, it is necessary to know the preload or the stiffness that changes based on the preload. If the rigidity is different, the gain that is the relationship between the axial load and the phase difference ratio is different, and this axial load may not be obtained with sufficient accuracy.

因に、上記転がり軸受ユニットの剛性をＫａ、この転がり軸受ユニットを構成する上記各転動体３、３の接触角をα、この転がり軸受ユニットの共振周波数（固有振動数）をｆａとした場合に、この転がり軸受ユニットの剛性Ｋａは、
Ｋａ＝ｆ（ｆａ、α） −−− （１）
で求められる。
又、上記各転動体３、３に付与される予圧Ｆａは、
Ｆａ＝ｆ（Ｋa 、α） −−− （２）
で求められる。
尚、上述の様な、共振周波数から転がり軸受ユニットの剛性Ｋａや予圧Ｆａを求める方法は、特許文献５〜７や非特許文献１等に記載されており、転がり軸受ユニットの技術分野で周知の技術である為、詳しい説明は省略する。
何れにしても、上記転がり軸受ユニットの仕様は既知であるから、この転がり軸受ユニットの共振周波数を測定できれば、この転がり軸受ユニットの剛性、更にはこの転がり軸受ユニットに付与されている予圧を推定できる。そして、この推定した予圧の値を利用する事により、物理量測定装置付転がり軸受ユニットを構成する演算器が、上記位相差比に基づいて上記アキシアル荷重を算出する際に使用するゲインを決定できる。 For example, when the rigidity of the rolling bearing unit is Ka, the contact angle of each of the rolling elements 3 and 3 constituting the rolling bearing unit is α, and the resonance frequency (natural frequency) of the rolling bearing unit is fa. The rigidity Ka of this rolling bearing unit is
Ka = f (fa, α) --- (1)
Is required.
The preload Fa applied to the rolling elements 3 and 3 is
Fa = f (Ka, α) (2)
Is required.
The method for obtaining the rigidity Ka and the preload Fa of the rolling bearing unit from the resonance frequency as described above is described in Patent Documents 5 to 7, Non-Patent Document 1, etc., and is well known in the technical field of rolling bearing units. Since it is a technology, detailed explanation is omitted.
In any case, since the specifications of the rolling bearing unit are known, if the resonance frequency of the rolling bearing unit can be measured, the rigidity of the rolling bearing unit and further the preload applied to the rolling bearing unit can be estimated. . Then, by using the estimated preload value, the arithmetic unit constituting the rolling bearing unit with a physical quantity measuring device can determine the gain to be used when calculating the axial load based on the phase difference ratio.

そこで、上述の様にして求めた、上記転がり軸受ユニットの予圧又は剛性に関する情報を記録し、当該転がり軸受ユニットに付属させる（この転がり軸受ユニットと共に後の組立工程に送れる様にする）。上記情報をこの転がり軸受ユニットに付属させる方法は特に問わないが、例えば、バーコードや２次元バーコード等として上記情報を印刷したラベル、或いは、この情報を記録したＩＣタグ等の電子部品を、貼付若しくは細紐等で結び付ける方法や、転がり軸受ユニットに直接マーキングする方法を採用できる。又、上記情報は、上記転がり軸受ユニットの予圧そのものであっても良いし、剛性、共振周波数等、この予圧に関連して（１対１で対応して）変化する値であっても良い。 Therefore, information relating to the preload or rigidity of the rolling bearing unit obtained as described above is recorded and attached to the rolling bearing unit (so that it can be sent to the subsequent assembly process together with the rolling bearing unit). The method for attaching the information to the rolling bearing unit is not particularly limited. For example, a label on which the information is printed as a barcode or a two-dimensional barcode, or an electronic component such as an IC tag on which the information is recorded, It is possible to adopt a method of attaching by sticking or thin string, or a method of marking directly on the rolling bearing unit. Further, the information may be the preload itself of the rolling bearing unit, or may be a value that changes (corresponding one-to-one) with respect to the preload, such as rigidity and resonance frequency.

上述の様にして、上記ゲインに結び付く予圧の値を求めた後、ステップ４（Ｓ４）で、エンコーダ４、４ａ、４ｂ、及びセンサ６ａ、６ｂ（図３〜８参照）を組み立てた後、ステップ５（Ｓ５）で、これら両センサ６ａ、６ｂの出力信号を確認する為の出力検査を行なう。この出力検査は、前記ハブ２を回転させて、上記両センサ６ａ、６ｂから信号を出力させる事で行なう。この出力検査の際、これら両センサ６ａ、６ｂの出力信号同士の間に存在する位相差比をチェックする事で、アキシアル荷重が作用しない状態での位相差比である、初期位相差比を確認する。そこで、ステップ６（Ｓ６）で、この初期位相差比と、上述した予圧若しくは予圧に関連して変化する値に基づいて、上記位相差比に基づいて上記アキシアル荷重を求める際の、零点及びゲインに関する情報を作成する。 After obtaining the preload value associated with the gain as described above, in step 4 (S4), the encoders 4, 4a, 4b and the sensors 6a, 6b (see FIGS. 3 to 8 ) are assembled, 5 (S5), an output test is performed to confirm the output signals of both the sensors 6a and 6b. This output inspection is performed by rotating the hub 2 and outputting signals from both the sensors 6a and 6b. During this output inspection, by checking the phase difference ratio existing between the output signals of both sensors 6a and 6b, the initial phase difference ratio, which is the phase difference ratio when no axial load is applied, is confirmed. To do. Therefore, in step 6 (S6), based on this initial phase difference ratio and the preload or a value that changes in relation to the preload, the zero point and gain when the axial load is calculated based on the phase difference ratio. Create information about.

この場合に、ゲインに関する情報は、前記ステップ３で前記転がり軸受ユニットの共振周波数を測定する事により得られた情報（予圧、剛性、共振周波数の何れか）からゲインマップを選択する（この情報に対応するマップを選択する）事で得られる。尚、ゲインマップは、転がり軸受ユニットの特性、使用される車両諸元等から、予め実験又は解析により、上記情報（予圧、剛性、共振周波数の何れか）とゲインとの関係を求める事により、容易に得られる。この場合に使用するゲインマップとしては、上記予圧等の情報を何種類かの範囲に分けて分類したものを使用する事が考えられる。この場合には、予め行なった実験又は解析に基づき、誤差を最小限に抑えられる様に（多種類になる面倒を許容できる範囲で、できるだけ多段階に）分割しておく。好ましくは、３〜１０段階に｛各段階の範囲が、予圧値で０．９８〜１．９６ｋＮ（１００ｋｇｆ〜２００ｋｇｆ）程度に収まる様に｝分割しておく。この程度に分割したマップのうちから、上記情報が対応するマップを選択して、上記位相差比から上記アキシアル荷重を算出する為のゲインを得る様にすれば、必要な精度を確保しつつ、ゲインの選定を容易に行なえる。 In this case, for gain information, a gain map is selected from the information (preload, stiffness, resonance frequency) obtained by measuring the resonance frequency of the rolling bearing unit in step 3 (in this information). Obtained by selecting the corresponding map). The gain map is obtained by obtaining the relationship between the above information (preload, stiffness, resonance frequency) and the gain from the characteristics of the rolling bearing unit, the specifications of the vehicle to be used, etc. in advance by experiment or analysis. Easy to get. As the gain map used in this case, it is conceivable to use information obtained by dividing the information such as the preload into several types of ranges. In this case, division is performed based on experiments or analyzes performed in advance so that errors can be minimized (in as many stages as possible within a range that allows for various types of trouble). Preferably, it is divided into 3 to 10 stages so that the range of each stage is within the range of about 0.98 to 1.96 kN (100 kgf to 200 kgf) as a preload value. While selecting the map corresponding to the above information from the maps divided to this extent and obtaining the gain for calculating the axial load from the phase difference ratio, while ensuring the necessary accuracy, Gain selection is easy.

一方、上記零点に関する情報は、前記ステップ５で行なった、前記両センサ６ａ、６ｂの出力信号を確認する為の出力検査時の初期位相差比に基づいて作成する。この場合に、この出力検査で求めた初期位相差比をそのまま零点として使用しても良いが、好ましくは、車両に取り付けた状態、即ち、懸架装置と車輪との間に設けて車重が加わっている状態での初期位相差を零点とする。車重が加わっている状態での初期位相差比を零点とすれば、直進走行時が零点と（車両に取り付けた状態でのトー角、キャンバー角、キャスター角等による多少のずれを無視すれば）ほぼ一致する。尚、車重が加わっている状態を零点とするには、物理量測定装置付転がり軸受ユニット組み付けた車両を、平坦路で直線走行させる事が考えられる（この場合には、トー角、キャンバー角、キャスター角によるずれを含んだ状態で上記初期位相差を求められる）。 On the other hand, the information regarding the zero point is created based on the initial phase difference ratio at the time of the output inspection for confirming the output signals of the two sensors 6a and 6b performed in step 5. In this case, the initial phase difference ratio obtained in the output inspection may be used as the zero point as it is. However, preferably, the initial phase difference ratio is attached to the vehicle, that is, provided between the suspension device and the wheel to add the vehicle weight. The initial phase difference in the state is set to zero. If the initial phase difference ratio in the state where the vehicle weight is applied is set to the zero point, when traveling straight, the zero point is the zero point (if the slight deviation due to the toe angle, camber angle, caster angle, etc. when attached to the vehicle is ignored) ) Almost matches. In addition, in order to make the state in which the vehicle weight is applied to be a zero point, it is conceivable that the vehicle assembled with the rolling bearing unit with a physical quantity measuring device is run in a straight line on a flat road (in this case, The initial phase difference can be obtained in a state including a shift due to the caster angle).

但し、この様な事を各車両毎に行なう事は面倒で、物理量測定装置付転がり軸受ユニットを搭載した車両のコスト上昇の原因となる。これに対して、上記ステップ５で行なう出力検査は、無負荷での回転検査であるから、この検査での初期位相差と、上記車重が加わった状態での初期位相差との間には、（車重の作用中心と転がり軸受ユニットの中心とがオフセットしていると、この車重により外輪１とハブ２との間にモーメントが加わる為）相違が存在する可能性がある。そこで、予め実験又は解析により、無負荷での初期位相差比と、車重が加わった状態での初期位相差比との関係を求めておき、上記ステップ５で行なう出力検査により得られた初期位相差比に基づいて、車重が加わった状態での初期位相差比を算出すれば、必要な精度を確保しつつ、初期位相差比の決定を容易に（実際に車両を走行させずに）行なえる。 However, it is troublesome to perform such a thing for each vehicle, which causes an increase in the cost of a vehicle equipped with a rolling bearing unit with a physical quantity measuring device. On the other hand, since the output inspection performed in step 5 is a rotation inspection with no load, there is no difference between the initial phase difference in this inspection and the initial phase difference with the vehicle weight added. (There is a possibility that a difference is present between the outer ring 1 and the hub 2 due to the vehicle weight if the center of action of the vehicle weight and the center of the rolling bearing unit are offset). Therefore, a relationship between the initial phase difference ratio with no load and the initial phase difference ratio with the vehicle weight added is obtained in advance by experiment or analysis, and the initial phase obtained by the output inspection performed in step 5 above is obtained. By calculating the initial phase difference ratio with the vehicle weight applied based on the phase difference ratio, it is easy to determine the initial phase difference ratio while ensuring the required accuracy (without actually driving the vehicle). ) Yes.

上述の様にして、前記両センサ６ａ、６ｂの出力信号同士の間に存在する位相差比に基づいてアキシアル荷重を求める為の零点及びゲインを得れば、物理量測定装置付転がり軸受ユニットを製造する通常の（元々必要な）工程中で、上記零点及びゲインを得られる。この為、検査・出荷工程を最小限にできて、上記物理量測定装置付転がり軸受ユニットを低コストで造れる。
即ち、車輪支持用転がり軸受ユニットに関しては、従来から予圧管理を行なっているし、ＡＢＳ制御用のエンコーダを組み込んだ回転速度測定装置付転がり軸受ユニットに関しては、従来からセンサの出力確認を、この回転速度測定装置付転がり軸受ユニットの製造工程内で行なっている。
そして、本発明を実施する場合に、上記予圧管理の工程を利用してゲインを得られるし、上記出力確認の工程を利用して、上記零点を得られる。この為、前述した特許文献４に記載した従来技術の様に、零点及びゲインを得る為に、専用の装置及び専用の工程を用意する必要がなくなり、上記物理量測定装置付転がり軸受ユニットの製造コストの低減を図れる。 As described above, if the zero point and gain for obtaining the axial load are obtained based on the phase difference ratio existing between the output signals of the sensors 6a and 6b, a rolling bearing unit with a physical quantity measuring device is manufactured. In the normal (originally necessary) process, the zero and gain can be obtained. Therefore, the inspection / shipment process can be minimized, and the above-mentioned rolling bearing unit with a physical quantity measuring device can be manufactured at low cost.
In other words, preload management is conventionally performed for the wheel bearing rolling bearing unit, and for the rolling bearing unit with a rotational speed measuring device incorporating an ABS control encoder, the sensor output confirmation has been performed conventionally. This is done in the manufacturing process of the rolling bearing unit with speed measuring device.
And when implementing this invention, a gain can be obtained using the said preload management process, and the said zero point can be obtained using the said output confirmation process. For this reason, unlike the prior art described in Patent Document 4 described above, it is not necessary to prepare a dedicated device and a dedicated process in order to obtain a zero and a gain, and the manufacturing cost of the rolling bearing unit with the physical quantity measuring device is eliminated. Can be reduced.

上述の様にして得た、上記零点及びゲインは、ステップ７（Ｓ７）で、前記演算器のメモリ中に記憶させ、ステップ８（Ｓ８）で、物理量測定装置付転がり軸受ユニットとして完成する。この場合に、この物理量測定装置付転がり軸受ユニット自体に上記演算器が組み込まれている（内蔵している）場合には、上記零点及びゲインに関する情報を、上記物理量測定装置付転がり軸受ユニットの製造工場で、直接上記演算器のメモリに記憶させれば良い。これに対して、演算器が別置きの場合（専用の荷重演算部を設ける場合、或いは、荷重演算の為のＣＰＵを他のコントロールユニットに搭載する場合等、転がり軸受ユニット部分にない場合）には、上記零点及びゲインは、自動車の組立工場で上記演算器に読み込ませる必要がある。そこで、この様な場合には、バーコードや２次元バーコード等として上記情報を印刷したラベル、或いは、この情報を記録したＩＣタグ等の電子部品を上記物理量測定装置付転がり軸受ユニットに、貼付若しくは細紐等で結び付ける。又は、転がり軸受ユニットに直接マーキングする事もできる。 The zero point and gain obtained as described above are stored in the memory of the computing unit in step 7 (S7), and completed in step 8 (S8) as a rolling bearing unit with a physical quantity measuring device. In this case, when the arithmetic unit is incorporated in (incorporated into) the rolling bearing unit with a physical quantity measuring device, information on the zero point and the gain is used to manufacture the rolling bearing unit with the physical quantity measuring device. What is necessary is just to memorize | store in the memory of the said calculator directly at a factory. On the other hand, when the arithmetic unit is installed separately (when a dedicated load calculation unit is provided, or when a CPU for load calculation is mounted on another control unit, such as when it is not in the rolling bearing unit). The zero point and gain need to be read into the arithmetic unit at the automobile assembly plant. Therefore, in such a case, a label on which the above information is printed as a barcode, a two-dimensional barcode, or an electronic component such as an IC tag on which this information is recorded is attached to the rolling bearing unit with a physical quantity measuring device. Or tie with a thin string. Alternatively, it is possible to directly mark the rolling bearing unit.

上述の説明は、車輪支持用転がり軸受ユニットに関して、１対のセンサの出力信号同士の間に存在する位相差比に基づき、外輪とハブとの間に加わるアキシアル荷重を求める場合を中心に説明した。但し、本発明の製造方法は、この様な車輪支持用転がり軸受ユニットに限らず、各種産業機械用、工作機械用の複列転がり軸受ユニットに加わる外力を測定する構造に適用できる。測定する外力の種類は、アキシアル荷重に限らず、ラジアル荷重、モーメントも対象となる。更に、センサに関しても、１対に限らず、複数組であっても対象となるし、前述の図９〜１０に示した従来構造の第４例の様に、センサが１個だけであっても良い。 In the above description, the rolling bearing unit for supporting the wheel has been described with a focus on the case of obtaining the axial load applied between the outer ring and the hub based on the phase difference ratio existing between the output signals of the pair of sensors. . However, the manufacturing method of the present invention can be applied not only to such a wheel support rolling bearing unit but also to a structure for measuring an external force applied to a double row rolling bearing unit for various industrial machines and machine tools. The types of external force to be measured are not limited to axial loads, but also include radial loads and moments. Furthermore, the sensor is not limited to a pair, and a plurality of sets can be targeted . As in the fourth example of the conventional structure shown in FIGS. 9 to 10 described above, there is only one sensor. Also good.

本発明の実施の形態の第１例に関して、物理量測定装置付転がり軸受ユニットの製造方法を工程順に示すフローチャート。The flowchart which shows the manufacturing method of a rolling-bearing unit with a physical quantity measuring apparatus in order of a process regarding the 1st example of embodiment of this invention. 転がり軸受ユニットを構成する各転動体に付与された予圧の大きさと、外力に基づいて１対のセンサの出力信号同士の間に生じる位相差比との関係を示す線図。The diagram which shows the relationship between the magnitude | size of the preload provided to each rolling element which comprises a rolling bearing unit, and the phase difference ratio produced between the output signals of a pair of sensor based on external force. 従来構造の第１例を示す断面図。Sectional drawing which shows the 1st example of a conventional structure. この第１例に組み込むエンコーダの一部を径方向から見た図。The figure which looked at a part of encoder incorporated in this 1st example from the diameter direction. アキシアル荷重に基づいて１対のセンサの出力信号が変化する状態を説明する為の線図。The diagram for demonstrating the state from which the output signal of a pair of sensor changes based on an axial load. 従来構造の第２例を示す断面図。Sectional drawing which shows the 2nd example of a conventional structure. 同第３例を示す断面図。Sectional drawing which shows the 3rd example. この第３例に組み込むエンコーダの一部を径方向から見た図。The figure which looked at a part of encoder incorporated in this 3rd example from the diameter direction. 従来構造の第４例を示す断面図。Sectional drawing which shows the 4th example of a conventional structure. この第４例に組み込むエンコーダの一部を径方向から見た図。The figure which looked at a part of encoder incorporated in this 4th example from the diameter direction.

１外輪
２ハブ
３転動体
４、４ａ〜４ｃエンコーダ
５カバー
６ａ、６ｂセンサ
７センサホルダ
８、８ａ、８ｂ透孔
９、９ａ、９ｂ柱部
１０第一特性変化部
１１第二特性変化部 DESCRIPTION OF SYMBOLS 1 Outer ring 2 Hub 3 Rolling element 4, 4a-4c Encoder 5 Cover 6a, 6b Sensor 7 Sensor holder 8, 8a, 8b Through-hole 9, 9a, 9b Column part 10 First characteristic change part 11 Second characteristic change part

Claims

A rolling bearing unit and a physical quantity measuring device;
Of these, the rolling bearing unit has a double-row stationary side raceway on the stationary side circumferential surface, and a stationary side raceway that does not rotate during use, and a rotational side circumferential surface that faces the stationary side circumferential surface in the radial direction. A plurality of rotation-side raceways that have double-row rotation-side tracks, and a rotation-side raceway that rotates during use, and a plurality of preloads for each row between the rotation-side raceways of both rows and the stationary-side raceways of both rows. And a rolling element provided so as to be able to roll freely in a state where
The physical quantity measuring device includes an encoder, at least one sensor, and a computing unit,
Of these, the encoder is supported and fixed concentrically with the rotation-side raceway by a part of the rotation-side raceway or a rotation member coupled and fixed concentrically with the rotation-side raceway. With the surface to be detected concentrically, and the characteristics of this surface to be detected are alternately changed in the circumferential direction.
The sensor is supported by a portion that does not rotate with the detection unit facing the detection surface of the encoder, and changes an output signal in response to a change in the characteristics of the detection surface.
Based on the output signal of the sensor, the calculator calculates the relative displacement between the stationary side raceway and the rotation side raceway and the external force acting between the stationary side raceway and the rotation side raceway. And having a function of calculating a physical quantity of at least one of
A method for manufacturing a rolling bearing unit with a physical quantity measuring device, comprising:
The degree to which the arithmetic unit calculates the physical quantity based on the output signal of the sensor, the degree to which the output signal or a value that changes according to the output signal changes, and the degree to which the physical quantity changes affecting a is the gain relationship with a characteristic related to the rolling bearing unit, the rigidity or preload of the rolling bearing unit, in the state of the rolling bearing unit alone, the rolling by applying a vibration to the rolling bearing unit Measurement by determining the resonance frequency of the bearing unit, and the physical quantity measurement in which the rigidity or data related to the rigidity, or the recording of the preload or data related to the preload is combined with the rolling bearing unit. by recording in the memory of the arithmetic unit constituting the apparatus, a gain this calculator uses, the rolling bearing unit Method of manufacturing a physical quantity measuring rolling bearing unit, characterized in that the one corresponding to the stiffness or preload.

After combining the rolling bearing unit and the physical quantity measuring device, the external force that fluctuates in the operating state is not applied between the stationary bearing ring and the rotating bearing ring, and the two bearing rings are in a neutral position. the output signal taken into the arithmetic unit, the output signal of the sensor in this state, the physical quantity as a zero point in the value of the output signal when present in a neutral state, is recorded in the memory of the arithmetic unit, wherein A method for manufacturing a rolling bearing unit with a physical quantity measuring device according to Item 1 .

A rolling bearing unit is a wheel bearing rolling bearing unit for rotatably supporting a wheel on a suspension device of an automobile, and a stationary raceway is an outer ring that is supported and fixed to the suspension device when in use. The manufacturing method of the rolling bearing unit with a physical quantity measuring device according to any one of claims 1 and 2 , wherein the raceway is a hub that rotates together with the wheel while the wheel is coupled and fixed.

The rolling bearing unit and physical quantity measuring device are combined, the outer ring is supported and fixed to the suspension device, the wheel is coupled and fixed to the hub, and the weight of the automobile is supported by the wheel on a flat surface. The sensor output signal is taken into the calculator while the outer wheel and the hub are in the neutral position without any external force changing between the hub and the driving state of the vehicle, and the sensor output signal in this state. The method of manufacturing a rolling bearing unit with a physical quantity measuring device according to claim 3 , wherein the physical quantity is recorded in a memory of a computing unit as a zero point which is a value of the output signal when the physical quantity exists in a neutral state.