JPH0315702A - Position detector for driving cylinder - Google Patents
Position detector for driving cylinderInfo
- Publication number
- JPH0315702A JPH0315702A JP15070489A JP15070489A JPH0315702A JP H0315702 A JPH0315702 A JP H0315702A JP 15070489 A JP15070489 A JP 15070489A JP 15070489 A JP15070489 A JP 15070489A JP H0315702 A JPH0315702 A JP H0315702A
- Authority
- JP
- Japan
- Prior art keywords
- shaft
- film
- magnet film
- sensor
- magnet
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/28—Means for indicating the position, e.g. end of stroke
- F15B15/2815—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT
- F15B15/2861—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT using magnetic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/28—Means for indicating the position, e.g. end of stroke
- F15B15/2815—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT
- F15B15/2846—Position sensing, i.e. means for continuous measurement of position, e.g. LVDT using detection of markings, e.g. markings on the piston rod
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Actuator (AREA)
Abstract
Description
【発明の詳細な説明】
「産業上のｆり用分野」
この発明は、油圧らしくは空気圧によって駆動される駆
動シリンダのシャフトの作動α置を検出する駆動シリン
ダ用位置検出器に関するものであ「従来の技術」
従来、駆動シリンダのシャフトの作動位置を検出する方
法としては、駆動シリンダの固定部に、シャフトと空隙
を隔てて対向するように磁気センサを取り付ける一方、
第７図（イ）および（口）に示すように、シャフトＩの
軸線方向に沿って一定ピンチでフエライト（＠性酸化物
）系の永久磁石材１４ ２２，・・を埋め込む方法、も
しくは、第８図（イ）および（ロ）に示すように、シャ
フト３全体を金属系永久磁石材料であるＦ ｅ−Ｃ ｒ
−Ｃ ｏ（鉄−クロムーコバルト）合金で構威し、この
ソヤフト３の軸線方向に沿って一定ピッチで着磁（正弦
波による磁気記録）を施す方法か知られていた。DETAILED DESCRIPTION OF THE INVENTION "Industrial Field" This invention relates to a position detector for a drive cylinder that detects the operating α position of the shaft of a drive cylinder driven by pneumatic pressure rather than hydraulic pressure. Conventional technology" Conventionally, as a method for detecting the operating position of the shaft of a drive cylinder, a magnetic sensor is attached to a fixed part of the drive cylinder so as to face the shaft across an air gap.
As shown in FIGS. 7(a) and 7(a), there is a method of embedding ferrite (@-type oxide)-based permanent magnet materials 14, 22, etc. along the axial direction of the shaft I with a constant pinch, or As shown in Figure 8 (a) and (b), the entire shaft 3 is made of Fe-Cr, which is a metallic permanent magnet material.
-Co (iron-chromium-cobalt) alloy, and a method of magnetizing (magnetic recording using a sine wave) at a constant pitch along the axial direction of the soyaft 3 was known.
「発明が解決しようとする課題」
ところで、上述した第７図に示す方法においては、シャ
フト１に一定ピッチで永久磁石材料２２．・・・を埋め
込まなければならないため、機械加工精度の関係からピ
ッチを細かく設定することができず、十分な立置分解能
が得られないという欠点があった。また、第８図に示す
方法においては、ピッチを細かく設定して十分な位置分
解能が得られるものの、シャフト３全体を金属系永久磁
石材料で構成しなければならないため、材料費が高くな
ってしまうという欠点があった。"Problem to be Solved by the Invention" By the way, in the method shown in FIG. 7 described above, the permanent magnet material 22. ... had to be embedded, the pitch could not be set finely due to machining accuracy, and there was a drawback that sufficient vertical resolution could not be obtained. In addition, in the method shown in Fig. 8, although sufficient position resolution can be obtained by setting the pitch finely, the entire shaft 3 must be constructed from a metallic permanent magnet material, which increases the material cost. There was a drawback.
この発明は上述した事情に鑑みてなされたもので、十分
な位置分解能が得られ、かつ安価に構成することができ
る駆動シリンダ用位置検出器を提供することを目的とし
ている。The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a position detector for a drive cylinder that can obtain sufficient position resolution and can be constructed at low cost.
「課題を解決するための手段」
この発明は、駆動シリンダのシャフトの作動位置を検出
する位置検出器において、前記シャフトの表面に被覆さ
れ、該シャフトの軸線方向へ所定ピッチで着磁された高
保磁力を有する磁石膜と、前記駆動シリンダの固定部に
、前記シャフトと空隙を隔てて配置され、前記磁石膜の
周囲の磁束を検出する磁気検出手段とを具備することを
特徴としている。``Means for Solving the Problems'' The present invention provides a position detector for detecting the operating position of a shaft of a drive cylinder, in which the surface of the shaft is coated and magnetized at a predetermined pitch in the axial direction of the shaft. The present invention is characterized in that it includes a magnet film having magnetic force, and a magnetic detection means that is arranged at a fixed portion of the drive cylinder with an air gap in between and the shaft, and detects magnetic flux around the magnet film.
「作用ｊ
上記の構成によれば、シャフトの表面に被覆された磁石
膜に着磁を施すので、着磁ビッチを細かく設定すること
ができ、また材料費を低く抑えることができる。Effect j According to the above configuration, since the magnet film coated on the surface of the shaft is magnetized, the magnetization pitch can be set finely, and the material cost can be kept low.
「実施例」
以下、図面を参照し、この発明の実施例について説明す
る。"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.
第１図〜第３図はこの発明の第１実施例の構成を示す図
である。まず、第１図において、５は駆動シリンダであ
り、空気圧もしくは油圧によってシャフト６が図面左右
方法へ移動する。７は駆動シリンダ５の端面に取り付け
られ、シャフト６と所定の空隙を隔てて対向する磁気セ
ンサであり、ＭＲ（＠気抵抗）素子を用いて構成されて
いる。また、シャフト６は、第２図（イ）および（口）
に示すように、シャフト基材８の表面に磁石膜９と保護
膜１０が順次形成された構成となっており、磁石膜９に
は、シャフト６の軸線方向に沿って所定ピッチで着磁が
施されている。この場合、第３図に示すように、磁石膜
９の厚さｔ，＝ＳＯμｍ，保護膜１０の厚さｔ，＝５μ
ｍ、シャフト６と磁気センサ７との間の空隙ｇ二！５０
μｍ１着磁ピヅチＰ＝２００μｍに各々設定されている
。そして、シャフト基材８は磁束の吸収を防ぐために非
磁性を有するオーステナイト系のステンレス鋼によって
構成されている。また、磁石膜９はスパッタリング法に
よって形成されており、十分な磁束が得られるように、
高保磁力を有するサマリウム１８％とコバルト８２％の
合金であるＳｍ−Ｃｏ（サマリウムーコバルト）合金膜
によって構成されている。この磁石膜９の厚さ１，は、
十分な磁束が得られるようにＩＯμｍ以上であることが
望ましい。また、保護ＭｌＯは耐摩耗性と耐腐食性を付
与するためのもので、硬質クロムメッキ膜によって構威
されている。1 to 3 are diagrams showing the configuration of a first embodiment of the present invention. First, in FIG. 1, 5 is a drive cylinder, and a shaft 6 is moved from side to side in the drawing by air pressure or oil pressure. A magnetic sensor 7 is attached to the end face of the drive cylinder 5 and faces the shaft 6 with a predetermined gap therebetween, and is constructed using an MR (@resistance) element. In addition, the shaft 6 is shown in Fig. 2 (a) and (mouth).
As shown in FIG. 2, a magnet film 9 and a protective film 10 are sequentially formed on the surface of the shaft base material 8, and the magnet film 9 is magnetized at a predetermined pitch along the axial direction of the shaft 6. It has been subjected. In this case, as shown in FIG.
m, the air gap between the shaft 6 and the magnetic sensor 7 g2! 50
Each μm1 magnetization pitch P is set to 200 μm. The shaft base material 8 is made of non-magnetic austenitic stainless steel to prevent absorption of magnetic flux. Moreover, the magnet film 9 is formed by sputtering method, and in order to obtain sufficient magnetic flux,
It is composed of an Sm-Co (samarium-cobalt) alloy film, which is an alloy of 18% samarium and 82% cobalt and has a high coercive force. The thickness 1 of this magnet film 9 is
It is desirable that the thickness is IO μm or more so that sufficient magnetic flux can be obtained. Further, the protective MlO is used to impart wear resistance and corrosion resistance, and is constituted by a hard chromium plating film.
ここで、上記磁気センサ７の出力特性について第４図お
よび第５図を参照して説明する。第４図はシャフト６と
の空隙ｇを１００μｍ１着磁ビツチＰを１００μｍとし
た場合における、シャフト６の移動距離と、センサ出力
電圧との関係を示している。また、第５図は、シャフト
６との間の空隙ｇとセンサ出力電圧との関係を示してい
る。Here, the output characteristics of the magnetic sensor 7 will be explained with reference to FIGS. 4 and 5. FIG. 4 shows the relationship between the moving distance of the shaft 6 and the sensor output voltage when the gap g with the shaft 6 is 100 μm and the magnetized bit P is 100 μm. Moreover, FIG. 5 shows the relationship between the gap g between the shaft 6 and the sensor output voltage.
以上の構成において、駆動シリンダが駆動され、そのシ
ャフト６が移動すると、磁石膜９の周囲に着磁ピッチＰ
に対応して生じている磁束が磁気センサ７を順次横切る
ので、磁気センサ７からは第４図と略同様な波形の出力
電圧が得られる。したがって、磁気センサ７の出力電圧
のピーク点やゼロクロス点をカウントすることによって
、基準位置からの移動量を検出することができる。In the above configuration, when the drive cylinder is driven and its shaft 6 moves, the magnetization pitch P around the magnet film 9 is
Since the magnetic flux generated in response to the above sequentially crosses the magnetic sensor 7, an output voltage having a waveform substantially similar to that shown in FIG. 4 is obtained from the magnetic sensor 7. Therefore, by counting the peak points and zero-crossing points of the output voltage of the magnetic sensor 7, the amount of movement from the reference position can be detected.
次に、この発明の第２実施例について、第６図を参照し
て説明する。この実施例においては、シャフト基材８が
鉄系材料である鋼材によって構成されており、このシャ
フト基材８によって磁束が吸収されるのを防ぐために、
磁石膜９の厚さと同等以上の厚さの非磁性の下地膜ＩＩ
が形威されている。この場合、下地膜ＩＩは、例えば銅
メッキ膜によって構成されており、シャフト基材８の表
面に下地膜１１と磁石膜９と保護膜１０が順次形成され
、下地膜ｌ１の厚さｔ。−６０μｍ１磁石膜９の厚さｔ
，＝６０μｍ，保護膜ＩＯの厚さｔｔ＝５μｍに各々設
定されている。Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the shaft base material 8 is made of steel, which is a ferrous material, and in order to prevent magnetic flux from being absorbed by the shaft base material 8,
Non-magnetic base film II with a thickness equal to or greater than the thickness of the magnet film 9
is in great shape. In this case, the base film II is composed of, for example, a copper plating film, and the base film 11, the magnet film 9, and the protective film 10 are sequentially formed on the surface of the shaft base material 8, and the thickness of the base film l1 is t. -60 μm 1 Thickness t of magnet film 9
, = 60 μm, and the thickness tt of the protective film IO = 5 μm.
上述した各実施例によれば、厚さｔ＋−５ ０〜６０μ
ｍという極めて薄い膜の磁石膜９に着磁を施廿ばよいの
で、着磁ビッチＰを細かく設定することができ、高い位
置分解能が得られ、また、材料費も低く抑えることがで
きる。According to each of the embodiments described above, the thickness t+-5 0 to 60μ
Since it is sufficient to magnetize the magnet film 9, which is an extremely thin film of m, the magnetization pitch P can be set finely, high positional resolution can be obtained, and material costs can be kept low.
なお、上述した磁気センサ７としてはホール素子等を用
いて乙よく、また磁石膜９としては高保磁力を有するも
のであれば、例えば、Ｎｄ−Ｆｅ−Ｂ（ネオノムー鉄−
ホウ素）合金等によって構成しても構わない。In addition, as long as the above-mentioned magnetic sensor 7 uses a Hall element or the like, and the magnet film 9 has a high coercive force, for example, Nd-Fe-B (neonium iron-
It may also be made of a boron alloy or the like.
「発明の効果コ
以上説明したように、この発明によれば、駆動シリンダ
のシャフトの表面に高保磁力を有する磁石膜をＷｌ覆し
、シャフトの軸線方向へ所定ピッチで着磁を施すように
したので、着磁ビブチを細かく設定することができ、こ
れにより十分な位置分解能が得られると共に、材料費を
低く抑えることができ、安価に構或することができると
いう効果が得られる。``Effects of the Invention'' As explained above, according to the present invention, a magnet film having a high coercive force is overlaid on the surface of the shaft of the drive cylinder, and magnetization is applied at a predetermined pitch in the axial direction of the shaft. , the magnetization bibuttons can be set finely, thereby obtaining sufficient positional resolution, and also having the effect that material costs can be kept low and construction can be made at low cost.
第１図はこの発明の第１実施例の全体構戊を示す一郎切
欠正面図、第２図（イ）および（口）は同実施例のシャ
フトの構成を示す一部切欠正面図および側面図、第３図
は同実施例の各部の寸法を説明するための図、第４図お
よび第５図は同実施例の磁気センサの出力特性を示すグ
ラフ、第６図はこの発明の第２実施例の各部の寸法を説
明するための図、第７図（イ）および（ロ）は従来の駆
動ノリンダ用位置検出器のシャフトの構戊を示す正面図
および側面図、第８図（イ）および（口）は従来の駆動
シ・リング用位置検出器のシャフトの構戊を示す正面図
および側面図である。
６・・・・・・シャフト、
７・・・・・・磁気センサ（磁気検出手段）、８・・・
・・・シャフト基材、９・・・・・・磁石膜、ｌＯ・・
・・・・保護膜、ＩＩ ・・・・・下地膜。FIG. 1 is a cutaway front view showing the overall structure of a first embodiment of the present invention, and FIGS. 2A and 2B are partially cutaway front and side views showing the structure of the shaft of the same embodiment. , FIG. 3 is a diagram for explaining the dimensions of each part of the same embodiment, FIGS. 4 and 5 are graphs showing the output characteristics of the magnetic sensor of the same embodiment, and FIG. 6 is a diagram showing the second embodiment of the present invention. Figures for explaining the dimensions of each part of the example, Figures 7 (a) and (b) are front and side views showing the structure of the shaft of a conventional drive nolinder position detector, and Figure 8 (a) and (2) are a front view and a side view showing the structure of a shaft of a conventional drive seat ring position detector. 6...Shaft, 7...Magnetic sensor (magnetic detection means), 8...
... Shaft base material, 9... Magnet film, lO...
...Protective film, II ... Base film.
Claims (1)
器において、 前記シャフトの表面に被覆され、該シャフトの軸線方向
へ所定ピッチで着磁された高保磁力を有する磁石膜と、 前記駆動シリンダの固定部に、前記シャフトと空隙を隔
てて配置され、前記磁石膜の周囲の磁束を検出する磁気
検出手段と、 を具備することを特徴とする駆動シリンダ用位置検出器
。[Scope of Claims] A position detector for detecting the operating position of a shaft of a drive cylinder, comprising: a magnet film having a high coercive force and coated on the surface of the shaft and magnetized at a predetermined pitch in the axial direction of the shaft; A position detector for a drive cylinder, comprising: magnetic detection means that is disposed at a fixed portion of the drive cylinder with a gap in between the shaft and detects magnetic flux around the magnet film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15070489A JPH0315702A (en) | 1989-06-14 | 1989-06-14 | Position detector for driving cylinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15070489A JPH0315702A (en) | 1989-06-14 | 1989-06-14 | Position detector for driving cylinder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0315702A true JPH0315702A (en) | 1991-01-24 |
Family
ID=15502593
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15070489A Pending JPH0315702A (en) | 1989-06-14 | 1989-06-14 | Position detector for driving cylinder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0315702A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0685927U (en) * | 1993-05-25 | 1994-12-13 | 日本トムソン株式会社 | Spline bearing |
| JP2006525529A (en) * | 2003-05-06 | 2006-11-09 | エスアールアイ インターナショナル | System and method for recording piston rod position information in a magnetic layer on a piston rod |
| JP2008536145A (en) * | 2005-04-13 | 2008-09-04 | エスアールアイ インターナショナル | System and method for magnetically sensing the position of a moving component |
| US8970208B2 (en) | 2010-02-11 | 2015-03-03 | Sri International | Displacement measurement system and method using magnetic encodings |
-
1989
- 1989-06-14 JP JP15070489A patent/JPH0315702A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0685927U (en) * | 1993-05-25 | 1994-12-13 | 日本トムソン株式会社 | Spline bearing |
| JP2006525529A (en) * | 2003-05-06 | 2006-11-09 | エスアールアイ インターナショナル | System and method for recording piston rod position information in a magnetic layer on a piston rod |
| US7737685B2 (en) | 2003-05-06 | 2010-06-15 | Sri International | Compositions for a magnetically hard layer on a piston rod |
| JP2011095269A (en) * | 2003-05-06 | 2011-05-12 | Sri Internatl | System and method for recording piston rod positional information on magnetic layer on piston rod |
| JP2008536145A (en) * | 2005-04-13 | 2008-09-04 | エスアールアイ インターナショナル | System and method for magnetically sensing the position of a moving component |
| US7755350B2 (en) | 2005-04-13 | 2010-07-13 | Sri International | System and method of perpendicularly magnetizing position information in a magnetically hard layer of a moving component |
| US8970208B2 (en) | 2010-02-11 | 2015-03-03 | Sri International | Displacement measurement system and method using magnetic encodings |
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