JPH03265704A - Fluid pressure cylinder - Google Patents
Fluid pressure cylinderInfo
- Publication number
- JPH03265704A JPH03265704A JP33992090A JP33992090A JPH03265704A JP H03265704 A JPH03265704 A JP H03265704A JP 33992090 A JP33992090 A JP 33992090A JP 33992090 A JP33992090 A JP 33992090A JP H03265704 A JPH03265704 A JP H03265704A
- Authority
- JP
- Japan
- Prior art keywords
- piston rod
- fluid pressure
- pressure cylinder
- scale
- detecting body
- 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.)
- Granted
Links
- 239000012530 fluid Substances 0.000 title claims description 12
- 239000000463 material Substances 0.000 claims abstract description 7
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 6
- 239000010959 steel Substances 0.000 claims abstract description 6
- 230000002093 peripheral effect Effects 0.000 claims abstract description 4
- 238000001514 detection method Methods 0.000 claims description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 6
- 229910052742 iron Inorganic materials 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 4
- 239000000428 dust Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000000985 reflectance spectrum Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
Abstract
Description
【発明の詳細な説明】
（発明の対象、産業上の利用分野）
本発明は、ピストンロッドにストローク検出用の目盛を
有する流体圧シリンダに関し、数値制御またはフィード
バック制御等に用いるサーボシリンダとして有用である
。Detailed Description of the Invention (Object of the Invention, Industrial Application Field) The present invention relates to a fluid pressure cylinder having a stroke detection scale on a piston rod, and is useful as a servo cylinder used for numerical control or feedback control. be.
（従来の技術）
流体圧シリンダを制御するためには、ストローク位置を
何らかの方法で検出する必要がある。このための従来の
方法はその一例として、当該シリンダのピストンと連動
する差動変圧器、ポテンショメータまたはディジタル的
な磁気式もしくは光学式のスケール等の測長機器を、流
体圧シリンダと並行して取付けておくことが行われてい
る。しかし、これではこれら測長機器が外方に突出する
ため、寸法形状の増大、他の装置との干渉および組立て
工数の増大等の問題がある。また、他の例として、特開
昭４ｉ１１７８８１号公報に開示されているように、ピ
ストンロッドに転接するローラを設けておき、このロー
ラの回転を回転パルス発振器等により検出する方法があ
る。この方法によると、寸法形状の増大は軽減するが、
ローラとピストンロッドとの間のすべりが生じると誤差
が発生し、またその接触面を常に清浄にしておくために
ダストワイパーが大がかりになるなど、複雑な構造とな
る難点を有している。(Prior Art) In order to control a fluid pressure cylinder, it is necessary to detect the stroke position by some method. Conventional methods for this include, for example, installing a length measuring device in parallel with the hydraulic cylinder, such as a differential transformer, a potentiometer or a digital, magnetic or optical scale, which is coupled to the piston of the cylinder. Things are being done. However, since these length measuring devices protrude outward, there are problems such as an increase in size, interference with other devices, and an increase in the number of assembly steps. As another example, as disclosed in Japanese Unexamined Patent Publication No. 4I117881, there is a method in which a roller is provided that rolls into contact with the piston rod, and the rotation of this roller is detected by a rotational pulse oscillator or the like. According to this method, the increase in size and shape is reduced, but
If slippage occurs between the roller and the piston rod, an error occurs, and a dust wiper is required to keep the contact surface clean at all times, resulting in a complicated structure.
（発明の目的）
本発明は、外部の測長機器を必要とせず、かつピストン
ロッドと非接触でストローク位置を検出することのでき
る流体圧シリンダを提供することを目的としている。(Objective of the Invention) An object of the present invention is to provide a fluid pressure cylinder that does not require an external length measuring device and can detect the stroke position without contacting the piston rod.
（発明の構成）
本発明は、ピストンロッドの周面部に、検出体よりなる
目盛を軸方向に形成してなる流体圧シリンダにおいて、
前記ピストンロッドは鉄鋼材料よりなり、前記検出体は
該ピストンロッドの表面が硬化された硬化層からなるこ
とを特徴とするものである。(Structure of the Invention) The present invention provides a fluid pressure cylinder in which a scale made of a detection body is formed in the axial direction on the peripheral surface of a piston rod.
The piston rod is made of a steel material, and the detection body is characterized in that the surface of the piston rod is made of a hardened layer.
（実施例）
第１図において、１は油圧・空圧等の流体圧によって直
線往復駆動するシリンダであって、シリンダチューブ２
の両端がヘンドカバー３及びロッドカバー４で覆われ、
かつシリンダチューブ２内に密に嵌合するピストン５と
、ピストン５に一体的に連結されロッドカバー４を密に
貫通するピストンロッド６とが、摺動可能に挿入されて
いる。(Example) In FIG. 1, 1 is a cylinder that is linearly reciprocated by fluid pressure such as hydraulic pressure or pneumatic pressure, and cylinder tube 2
Both ends are covered with a hend cover 3 and a rod cover 4,
A piston 5 that tightly fits into the cylinder tube 2 and a piston rod 6 that is integrally connected to the piston 5 and tightly passes through the rod cover 4 are slidably inserted.
ピストンロッド６の周面部には、検出体７よりなる目盛
８が、その軸方向に形成されている。この目盛８は、ピ
ストンロッド６の周面に沿った一定ピッチの螺旋状に形
成されている。ロッドカバー４の前面には、ロッドカバ
ー４とほぼ同径の検出ブロック９がボルト等により固定
されており、検出ブロック９には、検出体７に対向する
位置に検出面が配置されたセンサー１０ａ、１０ｂが、
互に周方向に１８０度ずれた位置でかつ軸方向に同一位
置に、その外方より挿入されている。１１は、ピストン
ロッド６に付着したゴご、油等を取除いて清浄にするた
めのダストワイパーである。A scale 8 made of a detection body 7 is formed on the circumferential surface of the piston rod 6 in the axial direction thereof. The scale 8 is formed in a spiral shape along the circumferential surface of the piston rod 6 at a constant pitch. A detection block 9 having approximately the same diameter as the rod cover 4 is fixed to the front surface of the rod cover 4 with bolts or the like, and the detection block 9 has a sensor 10a having a detection surface disposed at a position facing the detection body 7. , 10b is
They are inserted from the outside at positions 180 degrees apart in the circumferential direction and at the same position in the axial direction. Reference numeral 11 denotes a dust wiper for removing dirt, oil, etc. adhering to the piston rod 6 to clean it.
ピストンロッド６は、炭素鋼・ステンレス鋼等の鉄鋼材
料により製作されている。The piston rod 6 is made of a steel material such as carbon steel or stainless steel.
検出体７は、ピストンロッド６の表面に物理的または化
学的処理を施してピストンロッド６の材質より硬化され
た硬化層よりなる。すなわち、鉄鋼材料からなるピスト
ンロッド６の表面に、高周波焼入れまたは窒化等を施す
ることにより、その部分がマルテンサイトに組織変化し
て硬化した螺旋状の検出体７が形成される。このように
して形成された検出体７は、ピストンロッド６とは磁気
的性質を異にするので、磁界と組合せたセンサーにより
容易に検出することができる。また、ピストンロッド６
の表面に硬化した層よりなる検出体７を形成する方法と
して、第２図に示すごとく、ローラ１２をピストンロッ
ド６に強く押し当てつつ周面に沿って螺旋状に回転させ
ると、押圧された部分の結晶が砕かれて塑性変形を起こ
すとともに若干収縮するので、その後ピストンロッド６
の表面を研磨して凹凸のない円柱状に仕上げることとし
てもよい。The detection body 7 is made of a hardened layer that is made harder than the material of the piston rod 6 by subjecting the surface of the piston rod 6 to physical or chemical treatment. That is, by subjecting the surface of the piston rod 6 made of a steel material to induction hardening, nitriding, or the like, the structure of that portion changes to martensite, and a hardened spiral detection body 7 is formed. The detection body 7 formed in this way has different magnetic properties from the piston rod 6, and therefore can be easily detected by a sensor combined with a magnetic field. In addition, the piston rod 6
As shown in FIG. 2, as shown in FIG. 2, when the roller 12 is strongly pressed against the piston rod 6 and rotated spirally along the peripheral surface, the The crystals in the part are crushed and undergo plastic deformation and shrink slightly, so the piston rod 6
The surface may be polished to give a cylindrical shape with no irregularities.
また、センサー１０ａ、１０ｂは、ピストンロッド６と
検出体７との材質の相違を検出するもので、例えば鉄と
銅の導電率・透磁率等の差により出力を生じる高周波発
振形の近接センサーを用いる。The sensors 10a and 10b detect the difference in materials between the piston rod 6 and the detection body 7, and are, for example, high-frequency oscillation type proximity sensors that generate an output due to the difference in electrical conductivity, magnetic permeability, etc. between iron and copper. use
上述のように構成した流体圧シリンダ１は、負荷に取付
けることによってピストンロッド６の回転止めがなされ
、給排ボー）３ａ、４ａのいずれかより流体を供給する
ことにより、ピストン５及びピストンロッド６は直線往
復駆動する。その際に、センサー１０ａ、１０ｂは、検
出体６を検出して信号を発するので、この信号をパルス
カウンタ等によりカウントすることによって、ピストン
ロッドのストローク位置を検出することができる。In the fluid pressure cylinder 1 configured as described above, the piston rod 6 is prevented from rotating by being attached to a load, and the piston 5 and the piston rod 6 are fixed by supplying fluid from either the supply/discharge bow 3a or 4a. drives linearly back and forth. At this time, the sensors 10a and 10b detect the detection body 6 and emit a signal, so by counting this signal with a pulse counter or the like, the stroke position of the piston rod can be detected.
センサー１０ａ、１０ｂは、互に周方向１８０度ずらせ
て配置されているので、目盛８のピッチの半分毎に各セ
ンサー１０ａ、１０ｂより交互に信号を発し、目盛８の
ピッチよりもＡ細かいストローク位置を検出することが
できる。この実施例においては、２個のセンサー１０ａ
、１０ｂを用いたが、３個、または４個以上のセンサー
を周方向に等分した位置に配置することにより分解能を
たかめ、さらに細かいストローク位置を検出することが
できる。また、これらセンサーの周方向角度位置を調整
可能にしておけば、検出位置を微妙に調整することがで
き、高精度の検出が可能となる。Since the sensors 10a and 10b are arranged 180 degrees apart from each other in the circumferential direction, the sensors 10a and 10b alternately emit signals every half of the pitch of the scale 8, and the stroke position is A finer than the pitch of the scale 8. can be detected. In this embodiment, two sensors 10a
, 10b were used, but by arranging three or four or more sensors at positions equally divided in the circumferential direction, the resolution can be increased and even finer stroke positions can be detected. Furthermore, if the circumferential angular positions of these sensors are made adjustable, the detection position can be finely adjusted, allowing highly accurate detection.
上述の実施例においては、目盛８をピストンロッド６の
周面に沿った螺旋状に形成したが、これを例えばピスト
ンロッド６の周方向に連続した円環状の検出体を、軸方
向に等ピッチに配列してもよい。また、センサーｌＯと
しては、検出コイル、磁性抵抗素子、ホール素子または
これらと磁石との組合せによる電磁気的検出方式の他、
静電容量の変化またはピストンロッド６と検出体７との
光の反射率、吸収スペクトルの相違等を検出する光学的
検出方式のものをも適宜採用することができる。また流
体圧シリンダ１に、ピストンロッド６の回転防止装置を
設けてもよい。In the above embodiment, the scale 8 was formed in a spiral shape along the circumferential surface of the piston rod 6. For example, the scale 8 was formed in a spiral shape along the circumferential surface of the piston rod 6. may be arranged in In addition, as the sensor lO, in addition to an electromagnetic detection method using a detection coil, a magnetic resistance element, a Hall element, or a combination of these and a magnet,
An optical detection system that detects a change in capacitance or a difference in light reflectance or absorption spectrum between the piston rod 6 and the detection body 7 may also be appropriately employed. Further, the fluid pressure cylinder 1 may be provided with a device for preventing rotation of the piston rod 6.
（発明の効果）
本発明によると、ピストンロッドに目盛を形成している
ので外部の測長機器を必要とせず、かつピストンロッド
と非接触でストローク位置を検出でき、構造簡単で小型
であり、またスリップ等による誤差が絶無であるという
効果が得られる。(Effects of the Invention) According to the present invention, since a scale is formed on the piston rod, an external length measuring device is not required, and the stroke position can be detected without contacting the piston rod, and the structure is simple and small. Further, the effect that errors due to slips and the like are completely eliminated can be obtained.
またピストンロッドの表面に硬化層を形成するだけでよ
いから製造が容易で、安価に製作することができる。Further, since it is only necessary to form a hardened layer on the surface of the piston rod, manufacturing is easy and inexpensive.
図面は本発明の実施例であって、第１図は断面図、第２
図は目盛８を形成する方法の一例を示す図である。
ｌ・・・流体圧シリンダ、６・・・ピストンロッド、７
・・・検出体、８・・・目盛。
ゝ−−〜−−−ノThe drawings show embodiments of the present invention, in which Figure 1 is a sectional view and Figure 2 is a sectional view.
The figure is a diagram showing an example of a method of forming the scale 8. l...Fluid pressure cylinder, 6...Piston rod, 7
... Detection object, 8... Scale.ゝ－－〜－－－ノ
Claims (1)
向に形成してなる流体圧シリンダにおいて、前記ピスト
ンロッドは鉄鋼材料よりなり、前記検出体は該ピストン
ロッドの表面が硬化された硬化層からなることを特徴と
する流体圧シリンダ。In a fluid pressure cylinder in which a scale made of a detection body is formed in the axial direction on the peripheral surface of a piston rod, the piston rod is made of a steel material, and the detection body is made of a hardened layer on the surface of the piston rod. A fluid pressure cylinder characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33992090A JPH03265704A (en) | 1990-11-30 | 1990-11-30 | Fluid pressure cylinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33992090A JPH03265704A (en) | 1990-11-30 | 1990-11-30 | Fluid pressure cylinder |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3550683A Division JPS59164406A (en) | 1983-03-03 | 1983-03-03 | Fluid pressure cylinder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03265704A true JPH03265704A (en) | 1991-11-26 |
| JPH0423127B2 JPH0423127B2 (en) | 1992-04-21 |
Family
ID=18332015
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33992090A Granted JPH03265704A (en) | 1990-11-30 | 1990-11-30 | Fluid pressure cylinder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03265704A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11320184A (en) * | 1998-05-08 | 1999-11-24 | Smc Corp | Linear actuator |
| EP1653089A1 (en) * | 2004-10-27 | 2006-05-03 | Deere & Company | Device for determining the position of a moving piston rod with respect to a cylinder |
| US7280937B1 (en) | 2006-04-18 | 2007-10-09 | Deere & Company | System and method for detecting an axial position of a shaft |
| US7307418B2 (en) * | 2003-05-06 | 2007-12-11 | Sri International | Systems for recording position information in a magnetic layer on a piston rod |
| 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 |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5520083A (en) * | 1978-08-01 | 1980-02-13 | Fujitsu Ltd | Voltage control oscillator |
| JPS5716309A (en) * | 1980-07-04 | 1982-01-27 | Toshiba Mach Co Ltd | Displacement detector |
-
1990
- 1990-11-30 JP JP33992090A patent/JPH03265704A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5520083A (en) * | 1978-08-01 | 1980-02-13 | Fujitsu Ltd | Voltage control oscillator |
| JPS5716309A (en) * | 1980-07-04 | 1982-01-27 | Toshiba Mach Co Ltd | Displacement detector |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11320184A (en) * | 1998-05-08 | 1999-11-24 | Smc Corp | Linear actuator |
| US7307418B2 (en) * | 2003-05-06 | 2007-12-11 | Sri International | Systems for recording 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 |
| EP1653089A1 (en) * | 2004-10-27 | 2006-05-03 | Deere & Company | Device for determining the position of a moving piston rod with respect to a cylinder |
| US7116097B2 (en) | 2004-10-27 | 2006-10-03 | Deere & Company | System and method for detecting the axial position of a shaft or a member attached thereto |
| 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 |
| US7280937B1 (en) | 2006-04-18 | 2007-10-09 | Deere & Company | System and method for detecting an axial position of a shaft |
| EP1847809A1 (en) * | 2006-04-18 | 2007-10-24 | Deere & Company | Method and system for detecting an axial position of a shaft |
| US8970208B2 (en) | 2010-02-11 | 2015-03-03 | Sri International | Displacement measurement system and method using magnetic encodings |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0423127B2 (en) | 1992-04-21 |
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