JPH0559374B2 - - Google Patents
Info
- Publication number
- JPH0559374B2 JPH0559374B2 JP58238658A JP23865883A JPH0559374B2 JP H0559374 B2 JPH0559374 B2 JP H0559374B2 JP 58238658 A JP58238658 A JP 58238658A JP 23865883 A JP23865883 A JP 23865883A JP H0559374 B2 JPH0559374 B2 JP H0559374B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- torque
- transmission shaft
- detection
- torque transmission
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005291 magnetic effect Effects 0.000 claims description 118
- 230000005540 biological transmission Effects 0.000 claims description 41
- 238000001514 detection method Methods 0.000 claims description 41
- 239000002184 metal Substances 0.000 claims description 40
- 238000004804 winding Methods 0.000 description 11
- 238000010586 diagram Methods 0.000 description 10
- 230000035699 permeability Effects 0.000 description 10
- 230000004907 flux Effects 0.000 description 9
- 230000007423 decrease Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 229910001004 magnetic alloy Inorganic materials 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 230000005284 excitation Effects 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- 229910000702 sendust Inorganic materials 0.000 description 2
- 229910021364 Al-Si alloy Inorganic materials 0.000 description 1
- 229910017082 Fe-Si Inorganic materials 0.000 description 1
- 229910017133 Fe—Si Inorganic materials 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- 229910000676 Si alloy Inorganic materials 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
- G01L3/02—Rotary-transmission dynamometers
- G01L3/04—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft
- G01L3/10—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating
- G01L3/101—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means
- G01L3/102—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means involving magnetostrictive means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
- G01L3/02—Rotary-transmission dynamometers
- G01L3/04—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft
- G01L3/10—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating
- G01L3/101—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means
- G01L3/105—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means involving inductive means
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
- Power Steering Mechanism (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は非接触でトルクを検出するトルクセン
サに関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a torque sensor that detects torque without contact.
トルクは回転駆動系の制御を行なう際の基本量
の一つである。トルクを精密に検出するために
は、その検出機構が非接触方式であることが必要
である。
Torque is one of the basic quantities when controlling a rotational drive system. In order to accurately detect torque, the detection mechanism must be of a non-contact type.
近年、上述したような非接触の方式のトルクセ
ンサとしてアモルフアス磁性合金の薄帯を利用し
たものが提案されている（電気学会マグネテイツ
クス研究会資料MAG−81−72）。 In recent years, a non-contact type torque sensor as described above that uses a thin ribbon of amorphous magnetic alloy has been proposed (IEE of Japan Magnetics Study Group Material MAG-81-72).
このトルクセンサの概略構成図は第１図に示す
ようなものである。第１図において、トルクを検
出すべき回転軸、すなわちトルク伝達軸１にはア
モルフアス磁性合金から形成された環状磁心２が
巻回されて固定されている。この環状磁心２には
予めその周方向に対して角度θの傾き方向に一軸
磁気異方性Ku(4)が付与され、この方向に磁化し
やすくなつている。 A schematic configuration diagram of this torque sensor is shown in FIG. In FIG. 1, an annular magnetic core 2 made of an amorphous magnetic alloy is wound around and fixed to a rotating shaft on which torque is to be detected, that is, a torque transmission shaft 1. As shown in FIG. Uniaxial magnetic anisotropy Ku(4) is imparted to this annular magnetic core 2 in advance in a direction inclined at an angle θ with respect to its circumferential direction, so that it is easily magnetized in this direction.
上記トルクセンサの原理を概略的に説明する。
ここで、説明を簡単にするために、環状磁心２に
予め導入される一軸磁気異方性Ku(4)の方向を、
周方向に対してθ＝45゜の方向とする。いま、ト
ルク伝達軸１にトルク３を加えると、トルク伝達
軸１にはその周方向に対して±45゜の方向にひず
み応力が加わり、これに伴つてトルク伝達軸１に
完全密着した環状磁心２にもその周方向に対して
ひずみ応力σが生じる。このびずみ応力σによつ
て環状磁心２には一軸磁気異方性が誘導される。
この誘導された一軸磁気異方性が合成される結
果、一軸磁気異方性はKu(4)からKu′(5)へ変化す
る。トルク伝達軸１にトルク３が加わることによ
り、環状磁心２の一軸磁気異方性が変化すると、
磁束貫通方向における環状磁心２の透磁率が変化
する。この透磁率の変化は、例えば電圧変化とし
て検出される。したがつて、トルク３の大きさと
電圧変化の大きさとの対応関係から、トルクを検
出することができる。 The principle of the torque sensor described above will be schematically explained.
Here, to simplify the explanation, the direction of the uniaxial magnetic anisotropy Ku(4) introduced in advance into the annular magnetic core 2 is
The direction is θ=45° with respect to the circumferential direction. Now, when torque 3 is applied to the torque transmission shaft 1, strain stress is applied to the torque transmission shaft 1 in a direction of ±45° with respect to its circumferential direction, and as a result, the annular magnetic core that is in complete contact with the torque transmission shaft 1 2, strain stress σ is also generated in the circumferential direction. Uniaxial magnetic anisotropy is induced in the annular magnetic core 2 by this strain stress σ.
As a result of this induced uniaxial magnetic anisotropy being synthesized, the uniaxial magnetic anisotropy changes from Ku(4) to Ku'(5). When the uniaxial magnetic anisotropy of the annular magnetic core 2 changes due to the application of torque 3 to the torque transmission shaft 1,
The magnetic permeability of the annular magnetic core 2 in the magnetic flux penetration direction changes. This change in magnetic permeability is detected, for example, as a voltage change. Therefore, the torque can be detected from the correspondence between the magnitude of the torque 3 and the magnitude of the voltage change.
なお、環状磁心２に予め一軸磁気異方性Ku(4)
を導入してしない場合、トルク検出特性がヒステ
リシスを示すため、センサとて使用できなくな
る。 In addition, the annular magnetic core 2 has uniaxial magnetic anisotropy Ku(4)
If not introduced, the torque detection characteristics will exhibit hysteresis, making it unusable as a sensor.
なお、上記トルクセンサの説明では環状磁心を
構成する磁性体としてアモルフアス磁性合金を用
いた場合について述べたが、これに限らず軟質磁
性を示すものであれば、例えばパーマロイ（Fe
−Ni合金）、センダスト（Fe−Al−Si合金）、Fe
−Si合金など他の磁性体を用いることができる。 In the above description of the torque sensor, we have described the case where an amorphous magnetic alloy is used as the magnetic material constituting the annular magnetic core.
-Ni alloy), Sendust (Fe-Al-Si alloy), Fe
- Other magnetic materials such as Si alloys can be used.
上述した透磁率の変化の検出機構としては第２
図ａ及びｂに示すようなものが知られている。 The second mechanism for detecting the change in magnetic permeability described above is
Those shown in Figures a and b are known.
第２図ａは中空のトルク伝達軸１１に磁性金属
薄帯の環状磁心１２を固定し、ソレノイドコイル
１３を用いて環状磁心１２の周方向に励磁し、さ
らに検出巻線１４を巻いて出力を検出するもので
ある。また、同図ｂはトルク伝達軸１１に磁性金
属薄帯の環状磁心１２を固定し、その外周に巻か
れたソレノイドコイル１３′を用いて環状磁心１
２の巾方向に励磁し、さらにその外側に検出巻線
１４′を巻いて出力を検出するものである。 In Fig. 2a, an annular magnetic core 12 made of a thin magnetic metal strip is fixed to a hollow torque transmission shaft 11, the annular magnetic core 12 is excited in the circumferential direction using a solenoid coil 13, and a detection winding 14 is further wound to output an output. It is something to detect. In addition, in the same figure b, an annular magnetic core 12 made of a magnetic metal ribbon is fixed to a torque transmission shaft 11, and a solenoid coil 13' wound around the outer circumference of the annular magnetic core 12 is fixed.
The sensor is excited in the width direction of the sensor 2, and a detection winding 14' is further wound around the outer side of the sensor to detect the output.
すなわち、第２図ａ及びｂ図示の検出機構では
いずれも透磁率の変化をソレノイドコイルを検出
巻線との相互誘導による電圧の変化としてとら
え、増幅回路を経て出力を得るものである。 That is, in both the detection mechanisms shown in FIGS. 2a and 2b, a change in magnetic permeability is interpreted as a change in voltage due to mutual induction between a solenoid coil and a detection winding, and an output is obtained through an amplifier circuit.
上述したような検出機構で回転時のトルク検出
出力を実用レベルにするためにはトルク伝達軸に
巻いて固定する環状磁芯に予め大きな誘導磁気異
方性を付与しなければならないが、環状磁芯に大
きな誘導磁気異方性を±45゜方向に付与すること
は極めて困難である。また、トルグ伝達軸の全周
に亘つて連続的に透磁率を検出するため、透磁率
をどの位置でも一定値にする必要があるが、トル
ク伝達軸にFe系などの強磁性体を用いた場合、
材質の不均一性から一周のうちに透磁率変化が生
じる。したがつて、この透磁率変化に起因する出
力変動がトルクの検出出力に重畳されるためＳ／
Ｎ比が著しく低下する。
In order to achieve a practical level of torque detection output during rotation with the detection mechanism described above, it is necessary to impart large induced magnetic anisotropy to the annular magnetic core that is wound and fixed around the torque transmission shaft. It is extremely difficult to impart large induced magnetic anisotropy to the core in the ±45° direction. In addition, since the magnetic permeability is detected continuously over the entire circumference of the torque transmission shaft, it is necessary to keep the magnetic permeability at a constant value at any position. case,
Due to the non-uniformity of the material, magnetic permeability changes within one rotation. Therefore, since the output fluctuation caused by this permeability change is superimposed on the torque detection output, S/
The N ratio decreases significantly.
また、トルク伝達軸に雑音電流が流れた場合、
トルク伝達軸の周方向に磁束が生じ、この磁束に
起因する出力変動がトルクの検出出力に重畳され
るため、Ｓ／Ｎ比が著しく低下する。 Also, if a noise current flows through the torque transmission shaft,
Magnetic flux is generated in the circumferential direction of the torque transmission shaft, and output fluctuations caused by this magnetic flux are superimposed on the detected torque output, resulting in a significant decrease in the S/N ratio.
本発明は上記欠点を解消するためになされたも
のであり、Ｓ／Ｎ比を向上し、安定したトルク検
出を行なえるトルクセンサを提供しようとするも
のである。
The present invention has been made in order to eliminate the above-mentioned drawbacks, and aims to provide a torque sensor that can improve the S/N ratio and perform stable torque detection.
本発明のトルクセンサは、磁歪を有する磁性金
属薄体をトルク伝達軸に固定し、該軸に加えられ
たトルクにより前記磁性金属薄体の磁気特性が変
化することを利用してトルクの非抵触検出を行な
うトルクセンサにおいて、前記トルク伝達軸の周
方向の一部に誘導磁気異方性を有する長さｌがｌ
≦（1/2）・Ｌ（ただしＬはトルク伝達軸の全周）の
磁性金属体を一個または複数個固定し、この金属
薄体の回転面の外周に検出磁芯を配置したことを
特徴とするトルクセンサである。なお磁性金属薄
体の形状としては例えば薄帯などが挙げられる
が、薄膜形状でも良いことはいうまでもない。
The torque sensor of the present invention fixes a thin magnetic metal body having magnetostriction to a torque transmission shaft, and utilizes the fact that the magnetic properties of the thin magnetic metal body change due to the torque applied to the shaft to prevent torque from colliding with each other. In a torque sensor that performs detection, a length l having induced magnetic anisotropy in a part of the circumferential direction of the torque transmission shaft is l.
≦(1/2)・L (where L is the entire circumference of the torque transmission shaft) One or more magnetic metal bodies are fixed, and the detection magnetic core is arranged around the outer periphery of the rotating surface of this thin metal body. This is a torque sensor. Note that the shape of the magnetic thin metal body includes, for example, a thin ribbon, but it goes without saying that a thin film shape may also be used.
上述したようなトルクセンサによれば、トルク
伝達軸の一部にのみ磁性金属薄帯を固定するので
全周に磁性金属薄帯を巻回する場合に比べ、長さ
が短いので予め大きな誘導磁気異方性を付与する
ことが容易である。また、トルク伝達軸の周方向
の一部に磁性金属薄帯を固定しているので、その
部分ではトルク伝達軸の材質の不均一性の影響を
受けることが少なくなる。このため、１回転当り
の出力変動がほとんどなくなり、ほぼ静止状態と
等価な条件下で、Ｓ／Ｎ比が高く、かつ安定した
トルク検出が行なえる。更に、トルク伝達軸の全
周にわたつて磁性金属薄帯が固定されているので
はなく、磁性金属薄帯の端部の間に間〓が存在す
るので、トルク伝達軸に雑音電流が流れた場合で
もトルク伝達軸の周方向の磁束を切ることができ
る。このため、この磁束に起因する出力変動がト
ルクの検出出力に重畳されることなく、雑音電流
によるＳ／Ｎ比の低下を防止することができる。
しかも、磁性金属薄帯が存在する部分では、出力
にピークが生じるので、このピークを利用してト
ルク伝達軸の回転数を検出することもできる。 According to the above-mentioned torque sensor, since the magnetic metal ribbon is fixed only on a part of the torque transmission shaft, the length is shorter than when the magnetic metal ribbon is wound around the entire circumference, so it has a large induced magnetism. It is easy to impart anisotropy. Furthermore, since the magnetic metal ribbon is fixed to a portion of the torque transmission shaft in the circumferential direction, that portion is less affected by non-uniformity of the material of the torque transmission shaft. Therefore, there is almost no output fluctuation per revolution, and stable torque detection with a high S/N ratio can be performed under conditions almost equivalent to a stationary state. Furthermore, the magnetic metal ribbon is not fixed all the way around the torque transmission shaft, but there is a gap between the ends of the magnetic metal ribbon, so a noise current flows through the torque transmission shaft. It is possible to cut the magnetic flux in the circumferential direction of the torque transmission shaft. Therefore, output fluctuations caused by this magnetic flux are not superimposed on the detected torque output, and a decrease in the S/N ratio due to noise current can be prevented.
Furthermore, since a peak occurs in the output in the area where the magnetic metal ribbon exists, the rotational speed of the torque transmission shaft can also be detected using this peak.
なお、本発明のトルクセンサにおいて磁性金属
薄帯（複数個固定された場合はそれぞれの磁性金
属薄帯）の長さｌは、検出磁芯の有効磁路長さを
l′とすると、l′≦ｌ≦2l′の範囲にあることが望ま
しい。この理由を第３図及び第４図を参照して説
明する。第３図はトルク伝達軸の一部に固定され
た磁性金属薄帯２１の長さｌと検出磁芯２２の有
効磁路長さl′との関係を示す説明図、第４図はト
ルク伝達軸を回転した際、検出磁芯により得られ
るインダクタンスの特性図である。第３図におい
て有効磁路長さl′は検出磁芯２２が磁束変化を有
効に得ることができる磁路長さを意味する。ここ
で、磁路長さは、磁束が通過する検出磁芯２２中
の磁気抵抗が最も小さい部分、すなわち検出磁芯
２２の中央部を結んだ線の長さである。ただし、
インダクタンスに関しては、前記磁路のうち磁性
金属２１に直交する部分の長さは無視できるの
で、有効磁路長さl′は前記時路のうち磁性金属２
１に平行な部分の長さで表わされる。また、第４
図において、インダクタンスとは、検出巻線に生
じる誘導電流の大きさに相当する。第４図におい
て、磁性金属薄帯が存在する部分でインダクタン
スに非常に大きい突出部が現れるのは、磁性金属
薄帯の透磁率μが1000〜10000であるのに対し、
トルク伝達軸の透磁率μが10〜100であるためで
ある。したがつて、ｌがl′未満であると磁性金属
薄帯２１の磁束変化を有効に得ることができず、
第４図のインダクタンスＰが大幅に低下する。一
方、ｌが2l′を超えると第４図のＷが拡がるとと
もにＷの範囲内でインダクタンスＰが変動してし
まい、Ｓ／Ｎ比が著しく低下する。このため、ｌ
はl′≦ｌ≦2l′の範囲にあることが望ましい。ま
た、有効磁路l′を得るための磁芯の構造を考慮し
た場合、トルク伝達軸の直径を越えて磁心を配置
することは困難であり、実質的に有効磁路l′は
l′＜1/2Ｌである。トルク伝達軸の全周をＬとす
ると、なお磁性金属薄体の長さであるが、部分的
にすることで回転数の検出などの効果を得ること
ができ、また短くすればするほどトルク伝達軸の
材質の不均一などの影響を除外する効果が増大す
るが、磁性金属薄体もトルク伝達軸の全周Ｌの1/
２以下、すなわちｌ≦1/2Ｌであることが実質的に
有効である。 In addition, in the torque sensor of the present invention, the length l of the magnetic metal ribbon (or each magnetic metal ribbon if a plurality of magnetic metal ribbons are fixed) is equal to the effective magnetic path length of the detection magnetic core.
When l' is assumed, it is desirable that l'≦l≦2l'. The reason for this will be explained with reference to FIGS. 3 and 4. FIG. 3 is an explanatory diagram showing the relationship between the length l of the magnetic metal ribbon 21 fixed to a part of the torque transmission shaft and the effective magnetic path length l' of the detection magnetic core 22, and FIG. FIG. 7 is a characteristic diagram of inductance obtained by the detection magnetic core when the shaft is rotated. In FIG. 3, the effective magnetic path length l' means the magnetic path length that allows the detection magnetic core 22 to effectively obtain changes in magnetic flux. Here, the magnetic path length is the length of a line connecting the portion of the detection magnetic core 22 through which the magnetic flux passes and has the smallest magnetic resistance, that is, the center portion of the detection magnetic core 22. however,
Regarding inductance, since the length of the part of the magnetic path perpendicular to the magnetic metal 21 can be ignored, the effective magnetic path length l' is the magnetic metal 21 of the magnetic path.
It is expressed as the length of the part parallel to 1. Also, the fourth
In the figure, inductance corresponds to the magnitude of induced current generated in the detection winding. In Fig. 4, the reason why a very large protrusion appears in the inductance in the area where the magnetic metal ribbon exists is because the magnetic permeability μ of the magnetic metal ribbon is 1000 to 10000.
This is because the torque transmission shaft has a magnetic permeability μ of 10 to 100. Therefore, if l is less than l', the magnetic flux change of the magnetic metal ribbon 21 cannot be effectively obtained,
The inductance P shown in FIG. 4 is significantly reduced. On the other hand, when l exceeds 2l', W in FIG. 4 widens and the inductance P fluctuates within the range of W, resulting in a significant drop in the S/N ratio. For this reason, l
is preferably in the range l'≦l≦2l'. In addition, when considering the structure of the magnetic core to obtain the effective magnetic path l′, it is difficult to arrange the magnetic core beyond the diameter of the torque transmission shaft, and in reality the effective magnetic path l′ is
l′<1/2L. If the entire circumference of the torque transmission shaft is L, then this is the length of the magnetic thin metal body, but by making it partially, you can obtain effects such as detecting the rotation speed, and the shorter it is, the more the torque transmission will be. The effect of eliminating the effects of non-uniformity of the shaft material increases, but magnetic thin metal bodies also
2 or less, that is, l≦1/2L is substantially effective.
以下、本発明の実施例を第５図〜第７図を参照
して説明する。
Embodiments of the present invention will be described below with reference to FIGS. 5 to 7.
第５図中３１は直径55mmの強磁性体のトルク伝
達軸であり、このトルク伝達軸３１の軸方向の２
箇所には一対の磁性金属薄帯３２1，３２2がトル
ク伝達軸３１の周方向の一部に接着剤により固定
されている。これら磁性金属薄帯３２1，３２2は
単ロールにより作製された幅５mm、厚さ30μｍの
（Fe0.65Ni0.3Cr0.05）75Si11B14アモルフアス磁性合
金の薄帯をｌ＝10mmの長さに切出したものであ
る。また、これら磁性金属薄帯３２1，３２2には
トルク伝達軸３１の周方向に対してそれぞれ角度
θと角度−θの傾き方向に誘導磁気異方性が付与
されている。更に、磁性金属薄帯３２1，３２2の
回転面の外周には１mmのギヤツプを隔てて一対の
Ｕ型の検出磁芯３３1３３2の端部がトルク伝達軸
３１と同心円状に配設されている。これら検出磁
芯３３1，３３2にはそれぞれ励磁巻線３４1，３
４2及び検出巻線３５1，３５2が施されている。
また、検出巻線３５1と検出巻線３５2とは差動接
続されている。なお、前記検出磁芯３３1，３３2
の有効磁路長さl′はともに10mmとしてある。ま
た、励磁方向はトルク伝達軸の周方向である。 In Fig. 5, 31 is a ferromagnetic torque transmission shaft with a diameter of 55 mm.
A pair of magnetic metal thin strips 32 1 and 32 2 are fixed to a portion of the torque transmission shaft 31 in the circumferential direction using an adhesive. These magnetic metal thin strips 32 1 and 32 2 are made of (Fe 0.65 Ni 0.3 Cr 0.05 ) 75 Si 11 B 14 amorphous magnetic alloy thin strips with a width of 5 mm and a thickness of 30 μm produced by a single roll, and a length of l=10 mm. This is what was cut out. In addition, induced magnetic anisotropy is imparted to these magnetic metal ribbons 32 1 and 32 2 in the direction of inclination at an angle θ and an angle −θ with respect to the circumferential direction of the torque transmission shaft 31, respectively. Furthermore, the ends of a pair of U-shaped detection magnetic cores 33 1 33 2 are arranged concentrically with the torque transmission shaft 31 on the outer periphery of the rotating surfaces of the magnetic metal thin strips 32 1 and 32 2 with a gap of 1 mm between them. has been done. These detection magnetic cores 33 1 and 33 2 have excitation windings 34 1 and 3, respectively.
4 2 and detection windings 35 1 and 35 2 are provided.
Further, the detection winding 35 1 and the detection winding 35 2 are differentially connected. Note that the detection magnetic cores 33 1 , 33 2
The effective magnetic path length l′ of both is set to 10 mm. Further, the excitation direction is the circumferential direction of the torque transmission shaft.
上記トルクセンサを用いて回転数1500rpmのト
ルク伝達軸３１の動トルクを検出したところ、第
６図中のＡに示す如くＳ／Ｎ比が高く安定でしか
も線形性の優れた検出特性を得ることができた。 When the dynamic torque of the torque transmission shaft 31 at a rotational speed of 1500 rpm was detected using the above torque sensor, a detection characteristic with a high S/N ratio, stability, and excellent linearity was obtained as shown in A in Fig. 6. was completed.
また、上記トルクセンサでは既述した第４図に
示したように１回転当り１個（周方向に複数個の
磁性金属薄帯を固定した場合には複数個）のイン
ダクタンスＰのピークが得られるため、この出力
信号をカウンタ等の計数器に導入することにより
トルク伝達軸の回転数を得ることもできる。更
に、トルク伝達軸の全周にわたつて磁性金属薄帯
が固定されているのではなく、磁性金属薄帯の端
部の間に間〓が存在するので、トルク伝達軸に雑
音電流が流れた場合でもトルク伝達軸の周方向の
磁束を切ることができ、雑音電流によるＳ／Ｎ比
の低下を防止することができる。 In addition, in the above torque sensor, as shown in Fig. 4 described above, one peak of inductance P can be obtained per rotation (or multiple peaks if multiple magnetic metal thin strips are fixed in the circumferential direction). Therefore, the rotational speed of the torque transmission shaft can also be obtained by introducing this output signal into a counter such as a counter. Furthermore, the magnetic metal ribbon is not fixed all the way around the torque transmission shaft, but there is a gap between the ends of the magnetic metal ribbon, so a noise current flows through the torque transmission shaft. Even in such cases, the magnetic flux in the circumferential direction of the torque transmission shaft can be cut, and a decrease in the S/N ratio due to noise current can be prevented.
なお、上記実施例では磁性金属薄帯の長さと検
出磁芯の有効磁路長さl′とを等しくしたが、ｌ＝
2l′に設定した場合でも第６図中Ｂに示す如く上
記実施例と同様の良好な結果が得られた。 In the above embodiment, the length of the magnetic metal ribbon and the effective magnetic path length l' of the detection magnetic core were made equal, but l=
Even when the setting was 2l', good results similar to those of the above embodiment were obtained as shown in B in FIG.
一方、ｌ＝1/2l′の場合を第７図中Ｃに、ｌ＝
3l′の場合を第７図中Ｄにそれぞれ示す。第７図
から明らかなようにｌ＝1/2l′とした場合にはト
ルクの検出感度が大幅に低下している。また、ｌ
＝3l′の場合にはＳ／Ｎ比の低下から出力が不安
定になつている。したがつて、ｌはl′≦ｌ≦2l′の
範囲にあることが望ましいことがわかる。 On the other hand, the case of l = 1/2l' is shown in C in Fig. 7, and l =
The case of 3l' is shown in D in FIG. As is clear from FIG. 7, when l=1/2l', the torque detection sensitivity is significantly reduced. Also, l
In the case of =3l', the output becomes unstable due to a decrease in the S/N ratio. Therefore, it can be seen that l is preferably in the range l'≦l≦2l'.
なお、上記実施例と同様な効果は磁性金属薄帯
としてパーマロイ、センダスト、Fe−Si合金な
ど他の磁性体を用いた場合にも得られることが確
認された。 It has been confirmed that the same effect as in the above embodiment can also be obtained when other magnetic materials such as permalloy, sendust, and Fe-Si alloy are used as the magnetic metal ribbon.
また、トルクの正転反転に伴うトルク検出特性
の線形性を向上するためには上記実施例のように
一対の検出磁芯を用い、更に検出巻線を差動接続
することが望ましい。 Furthermore, in order to improve the linearity of the torque detection characteristic accompanying the normal rotation and reversal of torque, it is desirable to use a pair of detection magnetic cores as in the above embodiment and to differentially connect the detection windings.
以上詳述した如く本発明によれば、Ｓ／Ｎ比を
向上し、安定したトルク検出を行なえるトルクセ
ンサを提供することができるものである。
As described in detail above, according to the present invention, it is possible to provide a torque sensor that can improve the S/N ratio and perform stable torque detection.
第１図は非接触方式のトルクセンサの原理図、
第２図ａ及びｂはそれぞれ従来のトルクセンサの
構成図、第３図は本発明のトルクセンサにおける
磁性金属薄帯の長さｌと検出磁芯の有効磁路長さ
l′との関係を示す説明図、第４図は同トルクセン
サにより得られるインダクタンスの特性図、第５
図は本発明の実施例におけるトルクセンサの構成
図、第６図は本発明のトルクセンサによるｌ＝
l′及びｌ＝2l′の場合のトルク検出特性図、第７図
は本発明のトルクセンサによるｌ＝1/2l′及びｌ
＝3l′の場合のトルク検出特性図である。
３１……トルク伝達軸、３２1，３２2……磁性
金属薄帯、３３1，３３2……検出磁芯、３４1，
３４2……励磁巻線、３５1，３５2……検出巻線。
Figure 1 is a diagram of the principle of a non-contact torque sensor.
Figures 2a and b are block diagrams of conventional torque sensors, respectively, and Figure 3 shows the length l of the magnetic metal ribbon and the effective magnetic path length of the detection magnetic core in the torque sensor of the present invention.
Figure 4 is an explanatory diagram showing the relationship between
The figure is a configuration diagram of a torque sensor in an embodiment of the present invention, and FIG. 6 is a diagram showing the structure of a torque sensor according to an embodiment of the present invention.
A torque detection characteristic diagram in the case of l' and l=2l', FIG. 7 shows l=1/2l' and l by the torque sensor of the present invention.
FIG. 3 is a torque detection characteristic diagram when =3l'. 31...Torque transmission shaft, 32 1 , 32 2 ...Magnetic metal ribbon, 33 1 , 33 2 ...Detection magnetic core, 34 1 ,
34 2 ... excitation winding, 35 1 , 35 2 ... detection winding.
Claims (1)
固定し、該軸に加えられたトルクにより前記磁性
金属薄体の磁気特性が変化することを利用してト
ルクの非抵触検出を行なうトルクセンサにおい
て、前記トルク伝達軸の周方向の一部に誘導磁気
異方性を有する長さｌがｌ≦（1/2）・Ｌ（ただしＬ
はトルク伝達軸の全周）の磁性金属薄体を一個ま
たは複数個固定し、この金属薄体の回転面の外周
に検出磁芯を配置したことを特徴とするトルクセ
ンサ。 ２ トルク伝達軸の周方向に固定する磁性金属薄
体の長さｌが、検出磁芯の有効磁路長さをl′とす
ると、 l′≦ｌ≦2l′ の範囲にあることを特徴とする特許請求の範囲第
１項記載のトルクセンサ。[Claims] 1. A thin magnetic metal body having magnetostriction is fixed to a torque transmission shaft, and the magnetic properties of the thin magnetic metal body change due to the torque applied to the shaft. In the torque sensor that performs detection, the length l having induced magnetic anisotropy in a part of the circumferential direction of the torque transmission shaft is l≦(1/2)・L (however, L
A torque sensor characterized in that one or more thin magnetic metal bodies are fixed around the entire circumference of a torque transmission shaft, and a detection magnetic core is arranged on the outer periphery of the rotating surface of the thin metal bodies. 2. The length l of the thin magnetic metal body fixed in the circumferential direction of the torque transmission shaft is in the range of l'≦l≦2l', where l' is the effective magnetic path length of the detection magnetic core. A torque sensor according to claim 1.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58238658A JPS60129634A (en) | 1983-12-17 | 1983-12-17 | Torque sensor |
| EP84308792A EP0146382B1 (en) | 1983-12-17 | 1984-12-17 | Torque sensor of noncontact type |
| DE8484308792T DE3481546D1 (en) | 1983-12-17 | 1984-12-17 | TOUCH-FREE TORQUE PROBE. |
| US06/682,269 US4590807A (en) | 1983-12-17 | 1984-12-17 | Torque sensor of noncontact type |
| CA000470314A CA1222396A (en) | 1983-12-17 | 1984-12-17 | Torque sensor of noncontact type |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58238658A JPS60129634A (en) | 1983-12-17 | 1983-12-17 | Torque sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60129634A JPS60129634A (en) | 1985-07-10 |
| JPH0559374B2 true JPH0559374B2 (en) | 1993-08-30 |
Family
ID=17033398
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58238658A Granted JPS60129634A (en) | 1983-12-17 | 1983-12-17 | Torque sensor |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS60129634A (en) |
| CA (1) | CA1222396A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6275328A (en) * | 1985-09-30 | 1987-04-07 | Toshiba Corp | Torque sensor |
-
1983
- 1983-12-17 JP JP58238658A patent/JPS60129634A/en active Granted
-
1984
- 1984-12-17 CA CA000470314A patent/CA1222396A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CA1222396A (en) | 1987-06-02 |
| JPS60129634A (en) | 1985-07-10 |
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