JPH0518643Y2 - - Google Patents
Info
- Publication number
- JPH0518643Y2 JPH0518643Y2 JP16715186U JP16715186U JPH0518643Y2 JP H0518643 Y2 JPH0518643 Y2 JP H0518643Y2 JP 16715186 U JP16715186 U JP 16715186U JP 16715186 U JP16715186 U JP 16715186U JP H0518643 Y2 JPH0518643 Y2 JP H0518643Y2
- Authority
- JP
- Japan
- Prior art keywords
- rod
- current sensor
- eddy current
- output
- measured
- 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
- 238000001514 detection method Methods 0.000 claims description 8
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
Landscapes
- Actuator (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Indication Of The Valve Opening Or Closing Status (AREA)
Description
【考案の詳細な説明】
〔産業上の利用分野〕
この考案は、空圧あるいは油圧で作動する流体
圧シリンダや方向切換弁のスプール等、一般産業
機械に用いられる各種ロツドの位置を検出する装
置に関する。[Detailed description of the invention] [Field of industrial application] This invention is a device for detecting the position of various rods used in general industrial machinery, such as pneumatically or hydraulically operated fluid pressure cylinders and spools of directional control valves. Regarding.
ロツドの位置は、基準位置に対するロツドの移
動方向と基準点からの移動量とから判定できるも
のである。従来、この考案の出願人は、実願昭61
−62472号において、次のような構成のロツドの
位置検出装置を提案した。
The position of the rod can be determined from the direction of movement of the rod relative to the reference position and the amount of movement from the reference point. Previously, the applicant for this invention filed a Utility Application in 1983.
In No. 62472, we proposed a rod position detection device with the following configuration.
このものは、金属の種類によつて渦電流センサ
の出力が相違するという原理を応用したもので、
ロツドに設けられた複数の凹所のうち、隣合う三
つの凹所のそれぞれに異種金属を充填しておき、
ロツドの移動に伴つて渦電流センサから出力され
る異なるピーク値のパルス信号をカウントするこ
とによつてロツド移動量を検出し、また、それら
のピーク値の変化の割合を演算することによつて
ロツド移動方向を検出するようにしたものであ
る。 This device applies the principle that the output of an eddy current sensor differs depending on the type of metal.
Among the plurality of recesses provided in the rod, three adjacent recesses are each filled with different metals,
The amount of rod movement is detected by counting the pulse signals of different peak values output from the eddy current sensor as the rod moves, and by calculating the rate of change in those peak values. The rod movement direction is detected.
ところが、叙述の原理を応用してロツド位置を
検出する装置では、三種類の異種金属をロツドの
凹所に充填しておく必要があるのでロツド部分の
加工が複雑になるという問題があつた。
However, with the device that detects the rod position by applying the principle described above, there is a problem in that the machining of the rod part becomes complicated because it is necessary to fill the recesses of the rod with three different types of metals.
この考案は以上の問題を解決するもので、渦電
流センサの出力信号の波形が被測定部と渦電流セ
ンサとの間隔によつて相違するという事実を利用
することによつて、ロツド部分に複雑な加工を施
す必要がないロツドの位置検出装置を提供するこ
とを目的とする。 This idea solves the above problem by making use of the fact that the waveform of the output signal of an eddy current sensor differs depending on the distance between the part to be measured and the eddy current sensor. The object of the present invention is to provide a rod position detection device that does not require extensive processing.
以上の目的を達成するために講じた手段は、ロ
ツドの長手方向の複雑箇所に被測定部となる凹所
を設け、この凹所に対向する位置に渦電流センサ
を設けたロツドの位置検出装置において、前記被
測定部に設けられた凹所のうち、任意の三つの隣
会う凹所のそれぞれを異なる深さに形成し、前記
渦電流センサに、この渦電流センサから出力され
るパルス信号をカウントする回路と、この渦電流
センサから続いて出力される二つのパルス信号の
ピーク値の変化の割合を演算する回路とを接続し
たところにある。
The measures taken to achieve the above objectives were to create a rod position detection device by providing a recess to be measured at a complex longitudinal point of the rod, and installing an eddy current sensor at a position opposite to this recess. Of the recesses provided in the part to be measured, any three adjacent recesses are formed at different depths, and a pulse signal output from the eddy current sensor is sent to the eddy current sensor. This is where the counting circuit and the circuit that calculates the rate of change in the peak values of two pulse signals successively output from this eddy current sensor are connected.
以上のように構成されたロツドの位置検出装置
は次のように作用する。まずロツドが移動する
と、隣り会う三つの凹所の深さが異なつているた
め渦電流センサから三種類の異なる波形のパルス
信号が出力される。そして、パルス信号をカウン
トする回路により上記パルス信号がカウントさ
れ、その一方で、ピーク電圧値の変化の割合を演
算する回路により、渦電流センサから続いて出力
される二つのパルス信号のピーク値の変化の割合
が演算される。したがつて、パルス信号のカウン
ト数からピストンロツドの移動量が検出され、上
記ピーク値の変化の割合からピストンロツドの移
動方向が検出される。
The rod position detection device constructed as described above operates as follows. First, when the rod moves, the eddy current sensor outputs pulse signals with three different waveforms because the depths of the three adjacent recesses are different. Then, the pulse signals are counted by a circuit that counts the pulse signals, and at the same time, a circuit that calculates the rate of change in the peak voltage value calculates the peak value of the two pulse signals successively output from the eddy current sensor. The rate of change is calculated. Therefore, the amount of movement of the piston rod is detected from the count number of the pulse signal, and the direction of movement of the piston rod is detected from the rate of change in the peak value.
第１図はこの考案の第一実施例を示す構成図で
あり、１はロツド（たとえば油圧シリンダのピス
トンロツド）、２はロツドカバー等に配備された
渦電流センサ、３は渦電流センサ２の出力信号処
理回路として、パルス信号をカウントする回路及
び続いて出力される二つのパルス信号のピーク値
の変化の割合を演算する回路を示してある（な
お、この出力信号処理回路は、実願昭61−62472
号の装置と同様である。従つて、その説明は要部
のみにとどめる）。ロツド１の表面には三種類の
被測定部４ａ，４ｂ，４ｃをこのロツド１の長手
方向に間隔を隔てて繰り返し形成してあり、これ
らの被測定部４ａ，４ｂ，４ｃがロツド１の移動
に伴つて渦電流センサ２に順次対向する構成とな
つている。この実施例の被測定部４ａ，４ｂ，４
ｃは凹所５…により形成されており、それぞれの
凹所５…には第２図のように非磁性体よりなる表
面が平滑なライニング材６が充填されている。ま
た、同図に示すように、被測定部４ａ，４ｂ，４
ｃのそれぞれの凹所５…は深さが異なつており、
それぞれの被測定部４ａ，４ｂ，４ｃが渦電流セ
ンサ２に対向した状態では、それらの底面と渦電
流センサ２の表面との間の図示間隔la，lb，lcが
la＞lb＞lcの関係になるように設定されている。
次に、第１図に示した出力信号処理回路３は、渦
電流センサ２から出力されたパルス信号の増幅器
７と、増幅器７から続いて出力された四つのパル
ス信号を記憶するメモリ８と、メモリ８に記憶さ
れているパルス信号の中で最大ピーク値を示す信
号を検出する第一波高リミツタ９と、メモリ８に
記憶されているパルス信号の中で最大ピーク値を
示す信号の次に発生した信号を検出する第二波高
リミツタ１０と、第一波高リミツタ９と第二波高
リミツタ１０の出力信号が入力され、上記最大ピ
ーク値を示す信号とこの最大ピーク値を示す信号
の次に発生した信号との間のピーク値の変化率を
求める微分器１１と、この微分器１１により求め
られた上記変化率とあらかじめ設定されている基
準値とを比較する比較器１２と、第一波高リミツ
タ９の出力信号によつて増幅器７から出力される
パルス信号のカウントを開始するカウンタ１３
と、第一波高リミツタ９の出力信号によつて所定
時間の作動指令信号を出力するタイマ１４と、カ
ウンタ１３とタイマ１４の出力信号が印加されて
ロツド移動量を演算する演算器１５とからなる。
FIG. 1 is a configuration diagram showing a first embodiment of this invention, in which 1 is a rod (for example, a piston rod of a hydraulic cylinder), 2 is an eddy current sensor installed on a rod cover, etc., and 3 is an output signal of the eddy current sensor 2. As processing circuits, a circuit that counts pulse signals and a circuit that calculates the rate of change in the peak value of two pulse signals that are subsequently output are shown. 62472
It is similar to the device of No. Therefore, the explanation will be limited to the main parts only.) Three types of parts to be measured 4a, 4b, 4c are repeatedly formed on the surface of the rod 1 at intervals in the longitudinal direction of the rod 1, and these parts to be measured 4a, 4b, 4c are The configuration is such that they face the eddy current sensor 2 in sequence as the eddy current sensor 2 increases. Measured parts 4a, 4b, 4 of this embodiment
c is formed by recesses 5, and each recess 5 is filled with a smooth-surfaced lining material 6 made of a non-magnetic material as shown in FIG. In addition, as shown in the figure, the parts to be measured 4a, 4b, 4
The depths of the recesses 5 of c are different,
When each of the measured parts 4a, 4b, and 4c faces the eddy current sensor 2, the illustrated distances la, lb, and lc between their bottom surfaces and the surface of the eddy current sensor 2 are as follows.
The relationship is set to be la > lb > lc.
Next, the output signal processing circuit 3 shown in FIG. 1 includes an amplifier 7 for the pulse signal output from the eddy current sensor 2, a memory 8 for storing the four pulse signals successively output from the amplifier 7, A first wave height limiter 9 detects a signal showing the maximum peak value among the pulse signals stored in the memory 8, and a first wave height limiter 9 detects the signal showing the maximum peak value among the pulse signals stored in the memory 8. The output signals of the first wave height limiter 9 and the second wave height limiter 10 are inputted to a second wave height limiter 10 which detects the signal that has been detected, and the output signals of the first wave height limiter 9 and the second wave height limiter 10 are inputted, and the signal indicating the maximum peak value and the signal generated after the signal indicating this maximum peak value are input. A differentiator 11 that determines the rate of change of the peak value between the signals, a comparator 12 that compares the rate of change determined by the differentiator 11 with a preset reference value, and a first wave height limiter 9. A counter 13 starts counting the pulse signals output from the amplifier 7 according to the output signal of
, a timer 14 that outputs an operation command signal for a predetermined time based on the output signal of the first wave height limiter 9, and a calculator 15 that calculates the rod movement amount by applying the output signals of the counter 13 and the timer 14. .
次に作用を説明する。 Next, the effect will be explained.
第１図において、たとえばロツド１が矢印イで
示す方向に移動していくと、渦電流センサ２には
被測定部４ａ，４ｂ，４ｃがこの順に対向する。
ロツド１の材質が鉄の場合の渦電流センサの表面
及び被測定部の相互間距離ｌと渦電流センサの出
力電圧Ｖとの関係は、第４図に示すように、距離
ｌが大きくなるとそれに比例して出力電圧Ｖも大
きくなる。従つて、ロツド１の移動に伴つて渦電
流センサ２から出力されるパルス信号は第３図に
示したピーク値が異なる三種類の波形のパルス信
号ａ，ｂ，ｃとなる。ここで、ａのパルス信号は
被測定部４ａに、ｂのパルス信号は被測定部４ｂ
に、ｃのパルス信号は被測定部４ｃにそれぞれ対
応し、それらの繰り返し順序はロツド１の移動方
向に関係する。これらのパルス信号ａ，ｂ，ｃが
増幅器７で増幅されてメモリ８に印加され、この
メモリ８によつて記憶されると、第一波高リミツ
タ９がそのうちの最大ピーク値を示すパルス信号
ａを検出する。また、第二波高リミツタ１０がパ
ルス信号ａの次に発生したパルス信号、たとえば
ｂのパルス信号を検出する。そして、これら二つ
のパルス信号ａ，ｂの間のピーク値の変化率が微
分器１１で求められ、その変化率と基準値とが比
較器１２で比較される。そして、比較器１２で変
化率が基準値よりも大きいか小さいかが判定さ
れ、その判定に基づいてロツド１の移動方向を表
す信号が出力される。また、第一波高リミツタ９
がパルス信号ａを検出した時点でカウンタ１３が
パルス信号のカウントを開始し、その出力信号で
演算器１５が作動を開始する。同時にタイマ１４
が始動し、その出力信号が演算器１５に印加され
る。そして、演算器１５の一方の端子1にカウ
ント数に基づくロツド移動量が出力され、他方の
端子2にその移動速度が出力される。 In FIG. 1, for example, when the rod 1 moves in the direction indicated by arrow A, the parts to be measured 4a, 4b, and 4c face the eddy current sensor 2 in this order.
When the material of the rod 1 is iron, the relationship between the distance l between the surface of the eddy current sensor and the part to be measured and the output voltage V of the eddy current sensor is as shown in Figure 4. The output voltage V also increases proportionally. Therefore, the pulse signals output from the eddy current sensor 2 as the rod 1 moves become pulse signals a, b, and c of three types of waveforms having different peak values as shown in FIG. Here, the pulse signal a is sent to the part to be measured 4a, and the pulse signal b is sent to the part to be measured 4b.
The pulse signals c correspond to the parts to be measured 4c, respectively, and their repetition order is related to the moving direction of the rod 1. These pulse signals a, b, and c are amplified by the amplifier 7 and applied to the memory 8, and when stored in the memory 8, the first wave height limiter 9 outputs the pulse signal a having the maximum peak value. To detect. Further, the second pulse height limiter 10 detects a pulse signal generated next to pulse signal a, for example, a pulse signal b. Then, the rate of change in the peak value between these two pulse signals a and b is determined by the differentiator 11, and the rate of change and the reference value are compared by the comparator 12. Then, the comparator 12 determines whether the rate of change is larger or smaller than a reference value, and a signal representing the moving direction of the rod 1 is output based on the determination. In addition, the first wave height limiter 9
When the counter 13 detects the pulse signal a, the counter 13 starts counting the pulse signals, and the arithmetic unit 15 starts operating based on the output signal. At the same time timer 14
starts, and its output signal is applied to the arithmetic unit 15. Then, the rod movement amount based on the count is output to one terminal 1 of the arithmetic unit 15, and the movement speed is output to the other terminal 2 .
以上の説明では、第一波高リミツタ９によつて
最大ピーク値を示すパルス信号ａを検出する場合
を説明したが、第一波高リミツタ９によつて検出
するパルス信号はａ，ｂ，ｃのいずれであつても
よい。いずれの場合においても、渦電流センサ２
から続いて出力される二つのパルス信号のピーク
値の変化率を求め、その変化率を基準値と比較す
ることは可能だからである。また、この実施例で
説明した被測定部ａ，ｂ，ｃの凹所５…は、深さ
の異なる三つの螺旋溝をロツド１に形成すること
によつて形成してもよく、その場合でも、ロツド
の長手方向の複雑箇所に被測定部を設けるという
この考案の要件は満たされる。 In the above explanation, the case where the first wave height limiter 9 detects the pulse signal a indicating the maximum peak value has been explained. It may be. In either case, the eddy current sensor 2
This is because it is possible to find the rate of change in the peak values of the two pulse signals that are successively outputted from , and to compare the rate of change with a reference value. Further, the recesses 5 in the parts a, b, c to be measured explained in this embodiment may be formed by forming three spiral grooves with different depths in the rod 1; , the requirement of this invention that the part to be measured be provided at a complicated location in the longitudinal direction of the rod is satisfied.
この実施例によると、第６図に示したロツド移
動量と出力電圧との関係を表す特性図から明らか
なように、ロツド１が移動すると、それぞれの渦
電流センサ２ａ，２ｂ，２ｃからピーク値の異な
るパルス信号a′，b′，c′が出力される。a′のパル
ス信号は渦電流センサ２ａに、b′のパルス信号は
渦電流センサ２ｂに、c′のパルス信号は渦電流セ
ンサ２ｃにそれぞれ対応する。渦電流センサ２
ａ，２ｂ，２ｃから出力されたパルス信号はたと
えば第１図で説明した出力信号処理回路によつて
処理され、ロツド移動量、ロツド移動方向、ロツ
ド移動速度などが検出される。 According to this embodiment, as is clear from the characteristic diagram showing the relationship between rod movement amount and output voltage shown in FIG. Different pulse signals a', b', and c' are output. The pulse signal a' corresponds to the eddy current sensor 2a, the pulse signal b' corresponds to the eddy current sensor 2b, and the pulse signal c' corresponds to the eddy current sensor 2c. Eddy current sensor 2
The pulse signals outputted from a, 2b, and 2c are processed, for example, by the output signal processing circuit described in FIG. 1, and the rod movement amount, rod movement direction, rod movement speed, etc. are detected.
この考案において、被測定部を形成する手段と
しては、第一実施例のようにロツドに凹所を形成
する場合や第二実施例のようにロツドに凸部を形
成する場合のほかにも種々ある。たとえば、低温
窒化法や高周波焼入れ法などの手段によつてロツ
ドの表面組織の一部を変化させることもその例で
ある。 In this invention, there are various means for forming the part to be measured, in addition to forming a recess in the rod as in the first embodiment and forming a convex part in the rod as in the second embodiment. be. For example, changing part of the surface structure of the rod by means such as low-temperature nitriding or induction hardening is an example of this.
以上のように、この考案のロツドの位置検出装
置は、渦電流センサとロツドに形成した被測定部
との間隔が異なると渦電流センサの出力信号が相
違するという原理に基づくものであるから、被測
定部をロツドに設けた凹所により形成し、その凹
所に金属を充填してロツドの表面を平滑にする場
合でも一種類の金属を充填するだけでよい。また
被測定部は、ロツドの表面組織の一部を高周波焼
入れ、クフトライド等で変化させて被測定部を形
成すればロツドに機械的切削加工を施す必要が無
くなる。従つて、従来に比べて被測定部を形成す
るための加工が極めて容易になる。特に、ロツド
の表面組織の一部を変化させて被測定部を形成す
る場合には、ロツドの表面に切り欠きを作らない
のでロツドの強度が低下しない利点もある。
As described above, the rod position detection device of this invention is based on the principle that the output signal of the eddy current sensor differs when the distance between the eddy current sensor and the part to be measured formed on the rod differs. Even when the part to be measured is formed by a recess provided in the rod and the recess is filled with metal to smooth the surface of the rod, it is sufficient to fill the recess with one type of metal. Further, if the part to be measured is formed by changing a part of the surface structure of the rod by induction hardening, Kuftride, etc., there is no need to perform mechanical cutting on the rod. Therefore, the processing for forming the part to be measured becomes much easier than in the past. Particularly, when a part of the surface structure of the rod is changed to form the part to be measured, there is an advantage that the strength of the rod is not reduced because no notch is made on the surface of the rod.
第１図はこの考案の第一実施例によるロツドの
位置検出装置の構成図、第２図はその要部を示す
詳細図、第３図は第１図の渦電流センサから出力
されるパルス信号の波形を例示した特性図、第４
図は金属と渦電流センサとの間の距離と渦電流セ
ンサの出力電圧との関係を表した特性図である。
１……ロツド、２……渦電流センサ、３……出
力信号処理回路、４ａ，４ｂ，４ｃ，４ｄ……被
測定部、la，lb，lc……被測定部と渦電流センサ
との間隔。
Fig. 1 is a block diagram of a rod position detection device according to the first embodiment of this invention, Fig. 2 is a detailed view showing its main parts, and Fig. 3 is a pulse signal output from the eddy current sensor of Fig. 1. Characteristic diagram illustrating the waveform of
The figure is a characteristic diagram showing the relationship between the distance between the metal and the eddy current sensor and the output voltage of the eddy current sensor. 1... Rod, 2... Eddy current sensor, 3... Output signal processing circuit, 4a, 4b, 4c, 4d... Part to be measured, la, lb, lc... Distance between part to be measured and eddy current sensor .
Claims (1)
凹所を設け、この凹所に対向する位置に渦電流セ
ンサを設けたロツドの位置検出装置において、 前記被測定部に設けられた凹所のうち、任意の
三つの隣会う凹所のそれぞれを異なる深さに形成
し、前記渦電流センサに、この渦電流センサから
出力されるパルス信号をカウントする回路と、こ
の渦電流センサから続いて出力される二つのパル
ス信号のピーク値の変化の割合を演算する回路と
を接続したことを特徴とするロツドの位置検出装
置。[Scope of Claim for Utility Model Registration] In a rod position detection device, the rod is provided with recesses serving as parts to be measured at a plurality of locations in the longitudinal direction of the rod, and an eddy current sensor is provided at a position facing the recesses, A circuit for forming arbitrary three adjacent recesses among the recesses provided in the section at different depths, and for counting pulse signals output from the eddy current sensor in the eddy current sensor; A rod position detection device characterized in that it is connected to a circuit that calculates the rate of change in the peak value of two pulse signals successively output from the eddy current sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16715186U JPH0518643Y2 (en) | 1986-10-30 | 1986-10-30 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16715186U JPH0518643Y2 (en) | 1986-10-30 | 1986-10-30 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6372502U JPS6372502U (en) | 1988-05-14 |
| JPH0518643Y2 true JPH0518643Y2 (en) | 1993-05-18 |
Family
ID=31098816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16715186U Expired - Lifetime JPH0518643Y2 (en) | 1986-10-30 | 1986-10-30 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0518643Y2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3634675B2 (en) * | 1999-07-12 | 2005-03-30 | Ｓｍｃ株式会社 | Switching valve with position detection function |
| DE102005017498B4 (en) * | 2005-04-15 | 2010-07-08 | Siemens Ag | Synchronous linear motor with contactless scanning of the tooth structure of the abutment |
| WO2011096066A1 (en) * | 2010-02-04 | 2011-08-11 | トヨタ自動車株式会社 | Device for detecting shift/select position in parallel-shaft transmission for vehicle |
| JP5600841B2 (en) * | 2010-07-16 | 2014-10-08 | ダイハツ工業株式会社 | Gear position detection device for manual transmission |
| JP6122714B2 (en) * | 2013-07-03 | 2017-04-26 | Ｋｙｂ株式会社 | Displacement sensor |
| US9267819B2 (en) * | 2014-06-12 | 2016-02-23 | Mitutoyo Corporation | Absolute position encoder scale having plates alternating with varying recesses |
| JP6438233B2 (en) * | 2014-08-18 | 2018-12-12 | Dmg森精機株式会社 | Displacement detector |
| US9435663B2 (en) * | 2014-08-22 | 2016-09-06 | Mitutoyo Corporation | Absolute position encoder scale having layers in a stacked configuration |
-
1986
- 1986-10-30 JP JP16715186U patent/JPH0518643Y2/ja not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6372502U (en) | 1988-05-14 |
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