201217757 六、發明說明： [發明所屬之技術領域】 本發明係關於進行汽車及產業機器等之旋轉部位及直 線移動部位的位置檢測之磁性檢測型的位置檢測裝置。 【先前技術】 先前，檢測旋轉角度位置之磁性式的編碼器之狀況中 ’如日本專利申請公開H06-8 8704 (專利文獻1 )所示般， 利用接近配置之磁性感測器來檢測出因多極著磁之圓板狀 的磁石之旋轉所產生之磁場的方向之切換。圖1 0 A係專利 文獻1所示之磁性旋轉編碼器的俯視圖，參照記號與專利 文獻不同。圖10B及圖10C係爲了易於理解此磁性旋轉編碼 器的構造與動作，本案發明者所作成之用以說明的立體圖 及側視圖。於此先前技術中，以將著磁於旋轉軸方向之圓 板狀磁石分割成每個90°的扇狀磁石板81A〜81D，鄰接磁 石板的磁極性N，S相互反轉之方式配置，一體固定來形成 圓板狀的旋轉子8 1。從旋轉子8 1的板面隔開距離，在此範 例中爲3個磁性感測器82a、82b、82c於以旋轉子81的旋轉 軸Ox爲中心的相同圓上以60°的間隔來配置，_ 於圖1 OB、1 0C係代表3個磁性感測器之一，作爲磁性 感測器82來表示，磁性感測器82的磁場檢測方向係以箭頭 8 4所示般，爲與旋轉子81的板面垂直之方向。隨著旋轉子 8 1以旋轉軸〇x爲中心旋轉，在磁性感測器82位於相同磁極 上時，磁性感測器82係輸出相同電極性的磁性檢測訊號， 201217757 磁極反轉時則磁性檢測訊號的電極性也反轉。所以，旋轉 子8 1旋轉的話，磁性感測器82會輸出正負交替的磁性檢測 訊號。在圖10的先前技術中，從3個磁性感測器82a、82b 、82c取得相位相互偏離60。之3個磁性檢測訊號。 圖10C係揭示旋轉子81旋轉，磁性感測器82位於鄰接 之兩個磁石板81A與81 B之邊際時，此時磁性感測器82揭示 通過垂直方向（磁場檢測方向84)之磁場成分幾近零之狀 態。 在圖10A、10B、10C的先前技術中，鄰接之磁石板的 邊際附近之磁束密度較小，故磁性感測器從一方的磁石板 往另一方的磁石板相對移動時的磁場之切換較爲緩慢，結 果，磁性感測器之檢測輸出的上升、下降之斜度較小，利 用臨限値來邏輯判定磁性感測器的檢測輸出所得之位置檢 測訊號的磁滯寬度變大，位置檢測時機會延遲，又，難以 提升旋轉角度檢測精度。 【發明內容】 本發明的目的係提供位置檢測時機較不會延遲，可提 升檢測精度的位置檢測裝置。 第1發明所致之磁性檢測型的位置檢測裝置，係 包含： 環狀的磁性基板，係以軟磁性材形成； 偶數個圓弧狀的磁石板，係層積於前述磁性基板上， 相互隔開間隔而排列於第1圓周上； ⑧ -6 - 201217757 偶數個圓弧狀的磁軛板，係層積於各別之前述磁石板 上，以相互形成空隙而排列於第2圓周上的軟磁性材所形 成；及 磁性感測器.，係從前述磁軛板之排列的面往層積方向 ，隔開一定距離而可相對移動於圓周方向地配置； 鄰接之前述磁軛板之間的空隙，係與鄰接之前述磁石 板之間的間隔相等或比其狹窄，而位於前述間隔的中央； 各前述磁石板，係著磁於層積方向；鄰接之前述磁石板相 互對向的端面之著磁方向，係相互爲反極性。 第2發明所致之磁性檢測型的位置檢測裝置，係 包含： 圓弧狀的磁性基板，係以軟磁性材形成： 兩個圓弧狀的磁石板，係層積於前述磁性基板上，相 互隔開間隔而排列於第1圓周上； 兩個圓弧狀的磁軛板，係層積於各別之前述磁石板上 ，以相互形成空隙而排列於第2圓周上的軟磁性材所形成 :及 磁性感測器，係從前述磁軛板之排列的面往層積方向 ，隔開一定距離而可相對移動於圓周方向地配置； 鄰接之前述磁軛板之間的空隙，係與鄰接之前述磁石 板之間的間隔相等或比其狹窄，而位於前述間隔的中央； 各前述磁石板，係著磁於層積方向；鄰接之前述磁石板相 互對向的端面之著磁方向，係相互爲反極性。 第3發明所致之磁性檢測型的位置檢測裝置，係 201217757 包含： 磁性基板，係以軟磁性材形成，延長於一方向； 3個磁石板，係層積於前述磁性基板上，相互隔開間 隔而排列於前述磁性基板的長度方向； 3個磁軛板，係層積於各別之前述磁石板上，以相互 形成空隙而排列之軟磁性材所形成；及 磁性感測器，係從前述磁軛板之排列的面，隔開一定 距離而可相對移動地配置； 鄰接之前述磁軛板之間的空隙，係比鄰接之前述磁石 板之間的間隔還要狹窄，而位於前述間隔的中央；各前述 磁石板，係著磁於層積方向；鄰接之前述磁石板相互對向 的端面之著磁方向，係相互爲反極性。 [發明的效果] 本發明係可使磁力線集中於磁軛板的空隙附近，故相 對於空隙附近之位置的磁束密度之變化變爲急遽，結果， 位置檢測的時機遲緩變小，可發揮提升位置檢測精度變高 的效果。 【實施方式】 以下，針對本發明的實施例，進行詳細說明。 [第1實施例] 圖1 A係揭示此發明的第1實施例所致之磁性檢測型的 ⑧ -8- 201217757 位置檢測裝置的立體圖，圖1 B係揭示其俯視圖，圖1 C係掲 示側視圖。在此實施例，由環狀的磁性基板1 1、於其磁性 基板的板面上排列於圓周方向而安裝之圓弧狀的偶數個（ 在此範例中爲兩個）磁石板12A、12B、重疊於其磁石板各 別上而安裝之圓弧狀的偶數個磁軛板13A、13B構成旋轉子 1 〇。位置檢測裝置係包含旋轉子1 0，與和其磁軛板的板面 隔開一定間隔而可相對旋動地設置的磁性感測器1 4。 環狀的磁性基板1 1係由磁透率較高的軟磁性材料，例 如，高導磁合金（permalloy)或砍鋼板所作成。圓弧狀的 磁石板12A、12B係例如由鐵磁體（ferrite)系或釤鈷合金 (samarium cobalt)系或銳（neodymium)系等的強磁性 材，利用切削加工或成型加工來形成，具有由具有與環狀 的磁性基板1 1相同內徑與外徑之環狀磁石，以等圓弧長切 割出偶數個的形狀。各磁石板的圓弧之中心角係相互相等 ，該等的和小於360°，於磁性基板U上相互隔開間隔D， 於相同圓周上將磁石板排列於圓周方向。又，各磁石板12 、12B係以於與磁性基板11及磁軛板13A、13B的層積方向 (在此實施例中爲旋轉軸〇x方向）相互成爲反極性之方式 著磁。 圓弧狀的磁軛板13A、13B也排列於相同圓周上，磁軛 板13A的圓周方向兩端面係與鄰接之磁軛板13B的端面接近 ，隔開空隙G而對向。空隙G係比鄰接之磁石板12A、12B 之相互對向之端面之間的間隔D還要狹窄’且位於間隔D 的圓周方向中央。形成空隙G之磁軛板13A、13B的對向之 201217757 端點係如圖式般相互平行亦可，與圓周方向成直角之面亦 可。同樣地’形成間隔D之磁石板12A、12B的對向之端面 也相互平行亦可，與圓周方向成直角之面亦可。磁性基板 11、磁石板12A、12B、磁軛板13A、13B係層積於旋轉軸 Ox方向’相互例如以塑模（未圖示）固定外周面而形成旋 轉子1 0。於圖1的實施例中，此旋轉子1 〇係安裝於使用此 發明的位置檢測裝置之未圖示的產業機器所具有之旋動部 的旋動軸’於其產業機器的非可動部，磁性感測器1 4以與 磁軛板1 3 A、1 3 B的板面隔開距離而對向之方式固定。磁性 感測器1 4的磁場檢測方向係於圖中以箭頭1 4S所示般，爲 與磁軛板13A、13B的板面垂直，亦即，磁性基板、磁石板 、磁轭板的層積方向。 作爲磁性感測器14，例如可使用霍爾元件（Hall element)或磁電阻元件。例如在使用霍爾元件時，如圖2 所示，磁性感測器Μ具有4個端子，對一對端子施加恆定 電壓V b (恆定電壓動作時），從其他一對端子輸出磁性檢 測訊號VM。磁性檢測訊號VM係藉由邏輯判定電路2 0來放 大，並進行邏輯判定，判定結果作爲位置檢測訊號S D而被 輸出。 如圖1 C所示，來自磁石板1 2 B的磁力線大多進入磁透 率較高的磁軛板13B，被磁軛板13B導引而朝空隙G方向的 前端流動。結果，磁力線係集中於磁軛板13B的前端部， 從前端部附近的表面如以箭頭曲線所示，放射至空氣中。 磁力線係通過空隙G附近的空氣中，進入磁軛板1 3 A的前 ⑧ -10- 201217757 端部附近之表面，流動於磁軛板1 3 A中而進入磁石板1 2 A 。從磁石板1 2 A流出而進行磁性基板1 1之幾乎所有磁力線 係通過磁性基板1 1而回到磁石板1 2 B。於此實施例中，於 各空隙G中對向之磁極必須爲反極性，故空隙G必須爲偶 數，所以，磁石板與磁軛板也同樣地設置偶數個。 例如，於圖1 C以虛線所示般，磁性感測器1 4從磁軛板 1 3 B的表面位於上方時，磁性感測器1 4係檢測出貫通於磁 場檢測方向1 4S的磁力線所致之磁場，輸出對應其磁場之 方向的電極性之磁性檢測訊號VM。隨著藉由旋轉子1 0的旋 轉而磁性感測器14接近空隙G，貫通磁性感測器14之磁力 線的數量會增加，但是，其方向係在超越空隙G時反轉， 結果，磁性感測器1 4之磁性檢測訊號VM的電極性會反轉， 進而，隨著於磁軛板13A的圓周方向中磁性感測器14從空 隙G離開，貫通於反方向之磁力線的數量會減少。 圖1 A、1 B、1 C之實施例之狀況中，旋轉子1 〇旋轉1圈 時，磁性感測器1 4的磁性檢測訊號VM係如圖3 A所示，爲 正負交替之1週期的波形。圖3 A的波形係揭示磁性感測器 14的位置在空隙G的中央，旋轉子10開始旋轉，旋轉丨圈而 回到空隙G的中央之狀況。邏輯判定電路2 0係具有絕對値 相等之正與負的臨限値電壓+Vth，-Vth，如圖3 A、B所示 ，磁性檢測訊號V μ超過正的臨限値電壓+ V t h時，判定輸出 (亦即，位置檢測訊號S D )係成爲ON狀態（邏輯” 1 ”）。 此ON狀態係即使磁性檢測訊號VM降低至比+Vth還低，只 要負方向不超過-V t h的話’會被維持。接著，磁性檢測訊 -11 - 201217757 號νΜ於負方向超過-vth時，則成爲OFF狀態（邏輯”0")， 接著，到磁性檢測訊號Vm超過+Vth爲止，維持OFF狀態。 此種特性係稱爲磁滯。 如此一來，邏輯判定電路20係邏輯判定被輸入之例如 如圖3A所示之磁性檢測訊號VM，輸出如圖3B所示之位置 檢測訊號S d。如圖3 A、B所不’邏輯判定電路2 0係比較磁 性檢測訊號VM與臨限値電壓+Vth，-Vth，來進行邏輯判定 ，故例如磁性檢測訊號VM從+Vth變化成-Vth之角度寬度（ 磁滯寬度）dA之間，邏輯狀態係維持爲最近的狀態，故位 置檢測係會產生角度dA/2的延遲。所以，磁滯寬度dA係盡 可能小爲佳》 圖4 A係揭示藉由模擬來計算圖1的第1實施例與圖1 0、 10B、10C的先前技術之貫通磁性感測器14及82的磁力線之 磁場檢測方向成份的磁束密度之結果。但是，在此先前技 術中，使用4個扇狀磁鐵板，但是，爲了與圖1 A比較，圖 10A之磁石板的數量設爲兩個，而且設爲與圖1A相同的圓 弧狀，並設爲連結與圖1 A相同外徑及內徑之兩個圓弧狀磁 石板（中心角180°)的環狀旋轉子。以下將此稱爲變形先 前技術。 第1實施例的磁性基板11、磁石板12A、12B、磁軛板 13A、13B及變形先前技術的磁石板任一皆爲外徑1 1.5mm 、內徑8.5mm、厚度1mm。又，第1實施例及變形先前技術 之磁石板的保持力皆爲2 0 0k A/m。進而，在第1實施例中， 以電磁軟鐵（electromagnetic soft iron)來形成磁性基板 ⑧ -12- 201217757 11與磁軛板13A、13B。又，圓弧狀的各磁石板12A、12B 的中心角設爲140°，圓弧狀的各磁軛板13A、13B的中心角 設爲168.5°。所以，各間隔D的中心角爲40° (前述外徑與 內徑的中間約爲3.4 9 m m )，空隙G係1 · 〇 〇 m m (中心角 11.46。）。 針對在磁性感測器之半徑方向的位置任一皆爲從旋轉 子的中心離開1 〇mm，磁性感測器與旋轉子的表面之間的 距離（以下稱爲感測器距離）爲1mm之狀況與2mm之狀況 ，將藉由模擬來計算貫通磁性感測器之磁力線的磁場檢測 方向成份的磁束密度之結果，於圖4A的圖表之縱軸揭示。 橫軸係表示將磁性感測器的位置對合空隙G的中央（變形 先前技術之狀況爲鄰接磁石板的接合邊際）而設爲0，使 旋轉子旋轉的角度。由圖可知，在相同感測器距離中，第 1實施例所致之空隙附近的磁束密度比變形先前技術之磁 石板接合邊際附近的磁束密度還要高，但是，隨著從空隙 往圓周方向離開，磁束密度會減少，在此範例中比變形先 前技術還要低。此係揭示在此發明中藉由使用磁性基板1 1 及磁軛板13A、13B，從磁石板的表面之廣泛區域導引磁力 線’並使其集中於空隙附近。感測器距離越大的話，當然 在磁性感測器位置的磁束密度會越減少。 圖4B係放大圖4A之位置180°的附近者。將用以進行邏 輯判定電路20之邏輯判定的臨限値電壓+ Vth，-Vth所對應 之磁声密度分別設爲0.01T ( tesla) 、-0.01 T的話，感測器 距離爲1mm時，在第1實施例中磁滯寬度dA係約爲2.3°，比 -13- 201217757 變形先前技術的約2.9°還要狹窄。在感測器距離爲2mm時 ，第1實施例的磁滯寬度dA也比較小。所以，可知第1實施 例之位置檢測的時機延遲較小，位置檢測精度較高。 亦即，在先前的位置檢測裝置中將在磁石的表面之磁 束密度設爲一定的話，來自鄰接磁石板之接合部附近區域 的磁力線係集中於接合部而在接合部附近空間的磁束密度 變高，但是，來自磁石板表面的磁力線係被放射至磁透率 較低之空氣中，故隨著離開接合部，來自磁石表面的磁力 並不會太過集中於接合部附近。相對於此，在此發明中從 磁石板的表面發出之磁束係通過磁透率比空氣還高的磁軛 板，易於流動至空隙G方向，可使空隙附近之空間的磁束 密度比先前還要高。結果，在磁性感測器超越空隙時所產 生之磁束密度之反轉的坡度（亦即，檢測磁場之反轉的坡 度）變急遽，磁滯寬度變小。此效果係可藉由使用高磁透 率的磁軛板所得，間隔D與空隙G之圓周方向的長度（各 別長度以D與G表示）即使G=D，也可發揮此發明的效果 ，但是，D> G爲佳。 於變形先前技術中，可利用加強或增加磁石的保持力 ，來縮小磁滯寬度，但是，產生之磁力賦予周圍的影響也 會增加，且磁石的成本也會增加，所以並不理想。在此發 明中，利用軟磁性材來挾持磁石，故也有提升強度，磁導 係數變大，難以去磁的效果。 再者，在圖1 A、1 B、1 C的實施例，磁性基板1 1、磁 石板12A、12B、磁軛板13A、13B的外徑及內徑分別揭示 ⑧ -14- 201217757 相同狀況，但是，相較於磁性基板1 1及磁軛板1 3 A、1 3 B， 縮小磁石板1 2 A、1 2B的外徑及/或擴大磁石板1 2 A、1 2B的 內徑亦可。 [第2實施例] 圖5係揭示此發明所致之位置檢測裝置的第2實施例。 在此實施例，環狀的磁性基板1 1、排列於相同圓周上之圓 弧狀的磁石板1 2A、1 2B、排列於相同圓周上之圓弧狀的磁 軛板1 3 A、1 3 B，在相同面上於半徑方向從內側往外側依序 層積，形成旋轉子1〇。該等磁性基板11、磁石板12A、12B 、磁軛板13A、13B的旋轉軸之Ox方向的寬度相等。 圓弧狀的磁石板12A、12B係於層積方向，在此實施例 中爲半徑方向著磁，鄰接之磁石板的著磁方向係於半徑方 向中相互爲反極性。與第1實施例相同，各磁石板1 2 A、 1213的圓周方向兩端面係與分別鄰接之磁石板的一端面隔 開間隔D而對向，各磁軛板1 3 A、1 3 B也與鄰接者的圓周方 向端面隔開空隙G而對向。各空隙G係位於對應之間隔D的 中央。於此實施例中空隙G必須爲偶數個，所以，磁石板 及磁軛板也分別需要偶數個。 磁性感測器1 4係從磁軛板1 3 A、1 3 B的外周面往半徑方 向外側隔開距離而配置。磁性感測器1 4的磁場檢測方向 14S係與磁軛板13A、13B的外周面垂直之半徑方向（層積 方向）。除此之外，各構件的材質係與第1實施例所對應 者相同即可。因爲即使依據此第2實施例也可提升空隙G附 -15- 201217757 近的磁束密度，故位置檢測的磁滞寬度變小，所以，位置 檢測時機延遲變小，位置檢測精度變高。 [第3實施例] 圖6係掲示此發明所致之第3實施例的位置檢測裝置。 此實施例係具有切斷第1實施例之環狀的旋轉子10之環， 往直線方向延伸的構造。所以，磁性基板1 1係延伸成直線 軌道板狀，其上的磁石板及磁軛板係形成爲長方形。但是 ，因爲設置至少兩個空隙G，故設置有3個以上之所希望數 量的磁石板12A、12B、12C、12D…，與於其相同數量的 磁軛板13A、13B、13C、13D…。磁性基板11、磁石板12A 、12B、12C、12D及磁軛板 13A、13B、13C、13D 被層積 一體化所形成之直進體10’係於未圖示之產業機器所具有 之位置檢測對象的直線可動部，使其可動方向與直進體1 0 ’的長度方向一致而安裝。與直進體10’ 一起構成位置檢 測裝置的磁性感測器1 4係於產業機器之非可動部，從磁軛 板的表面隔開距離而固定。 第3實施例的各構成構件，也利用與第1實施例所對應 之構成構件相同的材質來構成即可。 [第4實施例] 於圖1 A、1 B、1 C的實施例中，爲了降低磁石材料的 成本，於各磁石板12A、12B的圓周方向中間部之1處或複 數處，形成切斷磁石板的間隙亦可。並於圖7揭示其範例 ⑧ -16- 201217757 。圖7係揭示將圖1的各磁石板12A、12B的兩端部分別作爲 磁石板片12A1、12A2及12B1、12B2而留下，切除中間部 且分別形成間隙1 2Ad、1 2Bd之狀況。所以，磁石板1 2A係 以磁石板片12A1與12A2的組群所構成，磁石板12B係以磁 石板片12B1與12B2的組群所構成。藉此，可減少磁石板 12A、12B所需之磁石材料的量。 再者，藉由如此隔開間隙而排列磁石板片1 2 A 1、 12A2、12B1、12B2，圓弧狀之各磁石板片的中心角會變 小，相對於其圓弧長度，寬度（半徑方向的長度）某種程 度夠大的話，不使用圓弧，使用長方形的磁石板片亦可。 此時，以長方形的4角任一都不會從磁性基板11及磁軛板 13A、13B的內周面及外周面往外超出之方式決定長方形的 尺寸與配置。 [第5實施例] 關於第5實施例，也與圖7的實施例相同，如圖8所示 ，以將磁石板12A及12B分別以複數磁石板片12A1、12A2 及1 2B1、12B2構成之方式，形成間隙12Ad及12Bd亦可。 [第6實施例] 在圖1的實施例，已揭示具有環狀的旋轉子1 〇之位置 檢測裝置的範例，但是，不作爲環狀，作爲圓弧狀亦可。 並於圖9揭示其範例。此範例係具有以通過中心軸Ox的道: 線切斷圖1B之旋轉子10所形成之180°的圓弧狀。空隙G係 -17- 201217757 未於圓弧的圓周方向中央。當然，作爲圓弧，並不需要爲 18 0°’比其大亦可，比其小亦可。如此藉由設爲圓弧狀的 旋轉子10，可減少磁石材料的量，可降低成本。 同樣地即使於圖5的實施例中，使用從環狀的旋轉子 10切出之圓弧狀的旋轉子（未圖示）亦可。又，如於圖9 以點虛線所示，將各磁石板1 2 A、1 2 B與圖7的實施例相同 ，以於圓周方向隔開間隙1 2 A d、1 2 B d而排列之複數磁石板 片的組群構成亦可。 [產業上之利用可能性] 本發明係可利用於產業機器之旋轉構件及直線可動構 件的位置檢測。 【圖式簡單說明】 圖1A係此發明之第1實施例的立體圖。 圖1B係第1實施例的俯視圖。 圖1C係第1實施例的側視圖。 圖2係用以說明處理磁性感測器與其磁性檢測訊號輸 出之邏輯判定電路的區塊圖。 圖3係揭示磁性檢測訊號的波形例，與邏輯判定磁性 檢測訊號所得之位置檢測訊號的波形的圖。 圖4 A係比較第1實施例與變形先前技術所致之磁性感 測器位置的磁束密度之模擬結果的圖表。 圖4B係圖4A之空隙G附近的放大圖。 -18- ⑧ 201217757 圖5係此發明之第2實施例的立體圖。 圖6係此發明之第3實施例的立體圖。 圖7係此發明之第4實施例的立體圖。 圖8係此發明之第5實施例的立體圖。 圖9係此發明之第6實施例的俯視圖。 圖1 〇 A係先前技術所致之旋轉編碼器的俯視圖。 圖10B係圖10A的立體圖。 圖1 0 C係圖1 0 A的側視圖。 【主要元件符號說明】 1 0、8 1 :旋轉子 10’ ：直進體 1 1 :磁性基板 12A1〜2、12B1〜2、12A〜D:磁石板 1 3 A〜D :磁軛板 1 4 :磁性感測器 1 4 S、8 4 :磁場檢測方向 20 :邏輯判定電路 8 1 A〜8 1 D :扇狀磁石板 8 2、8 2 a〜8 2 c :磁性感測器 1 2 A d、1 2 B d、D :間隔 G :空隙[Technical Field] The present invention relates to a magnetic detection type position detecting device that performs position detection of a rotating portion and a linear moving portion of an automobile or an industrial machine. [Prior Art] In the case of the magnetic encoder that detects the position of the rotation angle, as shown in Japanese Patent Application Laid-Open No. H06-8 8704 (Patent Document 1), the magnetic sensor is used to detect the cause. The switching of the direction of the magnetic field generated by the rotation of the multi-pole magnetic disk-shaped magnet. Fig. 10 A is a top view of the magnetic rotary encoder shown in the document 1, and the reference mark is different from the patent document. 10B and 10C are perspective views and side views for making the structure and operation of the magnetic rotary encoder easy to understand. In the prior art, the disk-shaped magnets that are magnetized in the direction of the rotation axis are divided into the fan-shaped magnet plates 81A to 81D of 90°, and the magnetic polarities N and S of the adjacent magnet plates are reversed. It is integrally fixed to form a disk-shaped rotor 8 1 . The distance from the plate surface of the rotor 8 1 is spaced apart. In this example, the three magnetic sensors 82a, 82b, 82c are arranged at intervals of 60° on the same circle centered on the rotation axis Ox of the rotor 81. _, FIG. 1 OB, 1 0C represents one of three magnetic sensors, and is shown as a magnetic sensor 82. The magnetic field detecting direction of the magnetic sensor 82 is indicated by an arrow 8 4 as a rotation. The direction of the face of the sub-81 is perpendicular. As the rotor 8 1 rotates around the rotation axis 〇x, when the magnetic sensor 82 is located on the same magnetic pole, the magnetic sensor 82 outputs a magnetic detection signal of the same polarity, and the magnetic detection is performed when the magnetic pole is reversed in 201217757 The polarity of the signal is also reversed. Therefore, if the rotating sub- 8 1 is rotated, the magnetic sensor 82 outputs a positive and negative alternating magnetic detecting signal. In the prior art of Fig. 10, phase deviations 60 are obtained from the three magnetic sensers 82a, 82b, 82c. 3 magnetic detection signals. Fig. 10C shows that the rotor 81 is rotated, and the magnetic sensor 82 is located at the margin of the adjacent two magnet plates 81A and 81B. At this time, the magnetic sensor 82 reveals the magnetic field component passing through the vertical direction (the magnetic field detecting direction 84). Near zero status. In the prior art of Figs. 10A, 10B, and 10C, the magnetic flux density near the margin of the adjacent magnet plate is small, so that the magnetic field of the magnetic sensor is relatively switched from one magnet plate to the other. As a result, the slope of the rise and fall of the detection output of the magnetic sensor is small, and the hysteresis width of the position detection signal obtained by logically determining the detection output of the magnetic sensor is increased by the threshold ,, and the position detection is performed. The opportunity is delayed, and it is difficult to improve the rotation angle detection accuracy. SUMMARY OF THE INVENTION An object of the present invention is to provide a position detecting device which can improve the detection accuracy without delaying the position detecting timing. The magnetic detecting type position detecting device according to the first aspect of the invention includes: a ring-shaped magnetic substrate formed of a soft magnetic material; and an even number of arc-shaped magnet plates laminated on the magnetic substrate and separated from each other Arranged on the first circumference at intervals; 8 -6 - 201217757 An even number of arc-shaped yoke plates are laminated on the respective magnet plates to form a gap with each other and arranged on the second circumference. a magnetic material is formed; and a magnetic sensor is disposed between the yoke plates adjacent to the yoke plate from the surface of the yoke plate in a stacking direction at a predetermined distance; The gap is equal to or narrower than the spacing between the adjacent magnet plates, and is located at the center of the interval; each of the magnet plates is magnetized in the stacking direction; adjacent to the opposite end faces of the magnet plates The magnetic direction is opposite to each other. The magnetic detecting type position detecting device according to the second aspect of the invention includes: an arc-shaped magnetic substrate formed of a soft magnetic material: two arc-shaped magnet plates are laminated on the magnetic substrate, and are mutually Arranged on the first circumference at intervals; two arc-shaped yoke plates are laminated on the respective magnet plates, and are formed of soft magnetic materials which are arranged on the second circumference by forming a gap therebetween And the magnetic sensor is arranged to be relatively movable in a circumferential direction from a surface in which the yoke plates are arranged in a stacking direction; a gap between the adjacent yoke plates is adjacent to The spacing between the magnet plates is equal or narrower than the narrow spacing, and is located at the center of the interval; each of the magnet plates is magnetized in a lamination direction; adjacent to the magnetic direction of the opposite end faces of the magnet plates They are opposite to each other. The magnetic detecting type position detecting device according to the third aspect of the present invention is characterized in that: the magnetic substrate is formed of a soft magnetic material and extended in one direction; and three magnet plates are laminated on the magnetic substrate and are spaced apart from each other. Arranged in the longitudinal direction of the magnetic substrate at intervals; three yoke plates are formed on the respective magnet plates, and are formed by soft magnetic materials in which voids are arranged to form each other; and the magnetic sensor is The surface of the yoke plate is arranged to be relatively movable with a certain distance; the gap between the adjacent yoke plates is narrower than the interval between the adjacent magnet plates, and is located at the interval The center of each of the magnet plates is magnetized in the stacking direction; the magnetic directions of the end faces of the adjacent magnet plates adjacent to each other are opposite to each other. [Effects of the Invention] According to the present invention, the magnetic flux is concentrated in the vicinity of the gap of the yoke plate, so that the change in the magnetic flux density with respect to the position near the gap becomes sharp, and as a result, the timing of the position detection becomes sluggish and the lift position can be exhibited. The detection accuracy becomes high. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail. [First Embodiment] Fig. 1A is a perspective view showing a magnetic detecting type 8-8-201217757 position detecting device according to a first embodiment of the present invention, and Fig. 1B shows a plan view thereof, and Fig. 1C shows a side view. view. In this embodiment, an even number of (in this example, two) magnet plates 12A, 12B, which are arranged in an arc shape, are arranged in the circumferential direction on the disk surface of the magnetic substrate 1 . An even number of yoke plates 13A and 13B which are arranged in an arc shape which are superimposed on the respective magnet plates are formed to constitute a rotor 1 〇. The position detecting device includes a magnetic sensor 14 which is rotatably provided at a predetermined interval from the plate surface of the yoke plate. The annular magnetic substrate 11 is made of a soft magnetic material having a high magnetic permeability, for example, a permalloy or a chopped steel plate. The arc-shaped magnet plates 12A and 12B are formed of, for example, a ferromagnetic system, a samarium cobalt system, or a neodymium-based ferromagnetic material, and are formed by cutting or molding. An annular magnet having the same inner diameter and outer diameter as the annular magnetic substrate 11 has an even number of shapes cut by an arc length. The central angles of the arcs of the respective magnet plates are equal to each other, and the sum is less than 360°, and the magnetic plates are spaced apart from each other by a space D, and the magnet plates are arranged in the circumferential direction on the same circumference. Further, each of the magnet plates 12 and 12B is magnetized so as to have a reverse polarity with respect to the lamination direction of the magnetic substrate 11 and the yoke plates 13A and 13B (in the embodiment, the direction of the rotation axis 〇 x). The arc-shaped yoke plates 13A and 13B are also arranged on the same circumference, and the circumferential end faces of the yoke plate 13A are close to the end faces of the adjacent yoke plates 13B, and are opposed to each other with the gap G interposed therebetween. The gap G is narrower than the interval D between the mutually opposing end faces of the adjacent magnet plates 12A and 12B and is located at the center in the circumferential direction of the interval D. The opposite ends of the yoke plates 13A, 13B forming the gap G may be parallel to each other as shown in the figure, and may be at right angles to the circumferential direction. Similarly, the opposite end faces of the magnet plates 12A and 12B forming the interval D may be parallel to each other, and may be a surface at right angles to the circumferential direction. The magnetic substrate 11, the magnet plates 12A and 12B, and the yoke plates 13A and 13B are laminated on the rotation axis Ox direction. The outer circumferential surface is fixed to each other by, for example, a mold (not shown) to form the rotor 100. In the embodiment of Fig. 1, the rotator 1 is attached to the non-movable portion of the industrial machine of the industrial machine which is not shown in the position detecting device of the present invention. The magnetic sensor 14 is fixed in such a manner as to be spaced apart from the plate faces of the yoke plates 1 3 A and 1 3 B. The magnetic field detecting direction of the magnetic sensor 14 is perpendicular to the plate surface of the yoke plates 13A, 13B as indicated by an arrow 14S in the drawing, that is, the lamination of the magnetic substrate, the magnet plate, and the yoke plate. direction. As the magnetic sensor 14, for example, a Hall element or a magnetoresistive element can be used. For example, when a Hall element is used, as shown in FIG. 2, the magnetic sensor Μ has four terminals, and a constant voltage V b is applied to a pair of terminals (at a constant voltage operation), and a magnetic detection signal VM is output from the other pair of terminals. . The magnetic detection signal VM is amplified by the logic decision circuit 20, and logically determined, and the result of the determination is output as the position detection signal S D . As shown in Fig. 1C, the magnetic lines of force from the magnet plate 1 2 B mostly enter the yoke plate 13B having a high magnetic permeability, and are guided by the yoke plate 13B to flow toward the front end in the direction of the gap G. As a result, the magnetic lines of force are concentrated on the front end portion of the yoke plate 13B, and the surface near the front end portion is radiated into the air as indicated by an arrow curve. The magnetic lines of force pass through the air in the vicinity of the gap G, enter the surface near the end of the front 8-10-201217757 of the yoke plate 13A, and flow into the yoke plate 13A to enter the magnet plate 1 2A. Almost all of the magnetic lines of force of the magnetic substrate 1 1 flowing out of the magnet plate 1 2 A pass through the magnetic substrate 1 1 and return to the magnet plate 1 2 B. In this embodiment, the opposing magnetic poles in each of the gaps G must have a reverse polarity, so the gap G must be an even number. Therefore, the magnet plates and the yoke plates are also provided in an even number. For example, when the magnetic sensor 14 is positioned above the surface of the yoke plate 1 3 B as shown by a broken line in FIG. 1 C, the magnetic sensor 14 detects magnetic lines of force penetrating the magnetic field detecting direction 14S. The magnetic field is output, and the magnetic detection signal VM corresponding to the polarity of the magnetic field is output. As the magnetic sensor 14 approaches the gap G by the rotation of the rotator 10, the number of magnetic lines of force passing through the magnetic sensor 14 increases, but the direction thereof reverses when the gap G is exceeded. As a result, magnetically sexy The polarity of the magnetic detection signal VM of the detector 14 is reversed. Further, as the magnetic sensor 14 is separated from the gap G in the circumferential direction of the yoke plate 13A, the number of magnetic lines that penetrate in the opposite direction is reduced. In the case of the embodiment of FIG. 1 A, 1 B, and 1 C, when the rotator 1 〇 rotates once, the magnetic detecting signal VM of the magnetic sensor 14 is as shown in FIG. 3A, and is one cycle of positive and negative alternating. Waveform. The waveform of Fig. 3A reveals that the position of the magnetic sensor 14 is in the center of the gap G, and the rotor 10 starts to rotate, and the ring is rotated to return to the center of the gap G. The logic decision circuit 20 has a positive and negative threshold voltages +Vth, -Vth which are absolutely equal to each other, as shown in FIGS. 3A and B, when the magnetic detection signal V μ exceeds the positive threshold voltage + V th The determination output (that is, the position detection signal SD) is in an ON state (logic "1"). This ON state is maintained even if the magnetic detection signal VM is lowered to be lower than +Vth, and the negative direction is not more than -V t h. Then, when the magnetic detection signal -11 - 201217757 ν Μ in the negative direction exceeds -vth, it turns OFF (logic "0"), and then until the magnetic detection signal Vm exceeds +Vth, it remains OFF. In this way, the logic decision circuit 20 logically determines the magnetic detection signal VM input, for example, as shown in FIG. 3A, and outputs the position detection signal S d as shown in FIG. 3B. As shown in FIG. 3A, B. The logical decision circuit 20 compares the magnetic detection signal VM with the threshold voltages +Vth, -Vth to perform a logic determination. Therefore, for example, the magnetic detection signal VM changes from +Vth to an angular width of -Vth (hysteresis width). Between dA, the logic state is maintained in the nearest state, so the position detection system will produce a delay of angle dA/2. Therefore, the hysteresis width dA is as small as possible. Figure 4 A shows the calculation by simulation The result of the magnetic flux density of the magnetic field detecting direction component of the magnetic field lines of the first embodiment of Fig. 1 and Figs. 10, 10B, and 10C of the prior art magnetic flux detectors 14 and 82. However, in the prior art, 4 is used. a fan-shaped magnet plate, but In order to compare with FIG. 1A, the number of the magnet plates of FIG. 10A is set to two, and is set to be the same arc shape as that of FIG. 1A, and is set to connect two circles having the same outer diameter and inner diameter as those of FIG. 1A. An annular rotor of an arc-shaped magnet plate (center angle of 180°). This will be referred to as a prior art of deformation. The magnetic substrate 11, the magnet plates 12A, 12B, the yoke plates 13A, 13B, and the prior art of the first embodiment Any one of the magnet plates has an outer diameter of 1.5 mm, an inner diameter of 8.5 mm, and a thickness of 1 mm. Further, the holding force of the magnet plate of the first embodiment and the prior art of the prior art is 200 k A/m. Further, In the first embodiment, the magnetic substrate 8-12-201217757 11 and the yoke plates 13A and 13B are formed by electromagnetic soft iron. Further, the central angle of each of the arc-shaped magnet plates 12A and 12B is set to 140. °, the central angle of each of the arc-shaped yoke plates 13A, 13B is set to 168.5. Therefore, the central angle of each interval D is 40 (the intermediate between the outer diameter and the inner diameter is about 3.4 9 mm), and the gap G Line 1 · 〇〇mm (center angle 11.46.). Any position in the radial direction of the magnetic sensor is from the rotor The center is separated by 1 〇mm, the distance between the surface of the magnetic sensor and the rotator (hereinafter referred to as the sensor distance) is 1 mm and the condition of 2 mm, and the magnetic lines of force passing through the magnetic sensor are calculated by simulation. The result of the magnetic flux density of the magnetic field detecting direction component is revealed on the vertical axis of the graph of Fig. 4A. The horizontal axis indicates that the position of the magnetic sensor is aligned with the center of the gap G (the state of the prior art is the joining of the adjacent magnet plates) Marginal) and set to 0, the angle at which the rotator is rotated. As can be seen from the figure, in the same sensor distance, the magnetic flux density near the gap caused by the first embodiment is higher than the magnetic flux density near the magnetic slab joint margin of the prior art, but with the circumferential direction from the gap. Leaving, the magnetic flux density is reduced, which is lower in this example than the prior art of the deformation. Thus, in the present invention, by using the magnetic substrate 11 and the yoke plates 13A, 13B, the magnetic lines ' are guided from a wide area of the surface of the magnet plate and concentrated in the vicinity of the gap. The larger the sensor distance, the less the magnetic flux density at the magnetic sensor position will be. Fig. 4B is an enlarged view of the vicinity of the position of Fig. 4A by 180°. When the magnetic sound density corresponding to the threshold voltages + Vth and -Vth of the logic determination circuit 20 is set to 0.01T (tesla) and -0.01 T, respectively, when the sensor distance is 1 mm, In the first embodiment, the hysteresis width dA is about 2.3°, which is narrower than the prior art of -13-201217757. When the sensor distance is 2 mm, the hysteresis width dA of the first embodiment is also relatively small. Therefore, it is understood that the timing of the position detection in the first embodiment is small, and the position detection accuracy is high. In other words, when the magnetic flux density on the surface of the magnet is constant in the position detecting device, the magnetic flux from the vicinity of the joint portion adjacent to the magnet plate is concentrated on the joint portion, and the magnetic flux density in the space near the joint portion becomes high. However, the magnetic lines of force from the surface of the magnet plate are radiated into the air having a low magnetic permeability, so that the magnetic force from the surface of the magnet does not become too concentrated near the joint portion as it leaves the joint portion. On the other hand, in the invention, the magnetic flux emitted from the surface of the magnet plate is passed through the yoke plate having a magnetic permeability higher than that of air, and it is easy to flow to the direction of the gap G, so that the magnetic flux density in the space near the gap can be made larger than before. high. As a result, the slope of the reversal of the magnetic flux density generated when the magnetic sensor exceeds the gap (i.e., the slope at which the magnetic field is reversed) becomes sharp, and the hysteresis width becomes small. This effect can be obtained by using a yoke plate having a high magnetic permeability, and the length of the interval D and the circumferential direction of the gap G (each length is represented by D and G) can exert the effect of the invention even if G=D. However, D> G is better. In the prior art of the deformation, the hysteresis width can be narrowed by reinforcing or increasing the holding force of the magnet. However, the magnetic force generated by the generated magnetic force also increases the influence of the magnet, and the cost of the magnet increases, which is not preferable. In this invention, the soft magnetic material is used to hold the magnet, so that the strength is increased, the magnetic permeability coefficient is increased, and the effect of demagnetization is difficult. Furthermore, in the embodiments of FIGS. 1A, 1B, and 1C, the outer diameter and the inner diameter of the magnetic substrate 11, the magnet plates 12A, 12B, and the yoke plates 13A, 13B respectively reveal the same condition of 8 -14 - 201217757, However, compared with the magnetic substrate 1 1 and the yoke plates 13 A and 1 3 B, the outer diameter of the magnet plates 1 2 A and 1 2B may be reduced and/or the inner diameters of the magnet plates 1 2 A and 1 2B may be enlarged. . [Second Embodiment] Fig. 5 is a view showing a second embodiment of the position detecting device of the present invention. In this embodiment, the ring-shaped magnetic substrate 11, the arc-shaped magnet plates 1 2A, 1 2B arranged on the same circumference, and the arc-shaped yoke plates 1 3 A, 1 3 arranged on the same circumference. B, in the radial direction, is laminated in order from the inner side to the outer side in the radial direction to form a rotator. The magnetic substrates 11, the magnet plates 12A and 12B, and the yoke plates 13A and 13B have the same width in the Ox direction of the rotation axis. The arc-shaped magnet plates 12A and 12B are in the stacking direction. In this embodiment, the magnetism is magnetized in the radial direction, and the magnetism directions of the adjacent magnet plates are opposite to each other in the radial direction. In the same manner as in the first embodiment, the circumferential end faces of the respective magnet plates 1 2 A and 1213 are opposed to each other with the end faces of the adjacent magnet plates, and the yoke plates 1 3 A and 1 3 B are also opposed. The space G is opposed to the circumferential end surface of the adjacent person. Each gap G is located at the center of the corresponding interval D. In this embodiment, the gap G must be an even number, so that the magnet plate and the yoke plate also require an even number, respectively. The magnetic sensor 14 is disposed with a distance from the outer peripheral surface of the yoke plates 1 3 A and 1 3 B to the outer side in the radial direction. The magnetic field detecting direction 14S of the magnetic sensor 14 is a radial direction (stacking direction) perpendicular to the outer peripheral surfaces of the yoke plates 13A and 13B. In addition, the material of each member may be the same as that of the first embodiment. Since the magnetic flux density near the gap G -15 - 201217757 can be increased according to the second embodiment, the hysteresis width of the position detection becomes small, so that the position detection timing delay becomes small and the position detection accuracy becomes high. [THIRD EMBODIMENT] Fig. 6 is a view showing a position detecting device according to a third embodiment of the present invention. This embodiment has a structure in which the ring of the ring-shaped rotor 10 of the first embodiment is cut and extends in the straight line direction. Therefore, the magnetic substrate 11 extends in a linear track plate shape, and the magnet plate and the yoke plate thereon are formed in a rectangular shape. However, since at least two gaps G are provided, three or more desired numbers of magnet plates 12A, 12B, 12C, 12D, ... are provided, and the same number of yoke plates 13A, 13B, 13C, 13D, ... are provided. The linear body 10' formed by laminating the magnetic substrate 11, the magnet plates 12A, 12B, 12C, and 12D and the yoke plates 13A, 13B, 13C, and 13D is attached to a position detecting object of an industrial machine (not shown). The linear movable portion is mounted so that the movable direction thereof coincides with the longitudinal direction of the straight body 10'. The magnetic sensor 14 that constitutes the position detecting device together with the straight body 10' is attached to the non-movable portion of the industrial machine, and is fixed by a distance from the surface of the yoke plate. Each of the constituent members of the third embodiment may be configured by the same material as the constituent members corresponding to the first embodiment. [Fourth Embodiment] In the embodiment of Figs. 1A, 1B, and 1C, in order to reduce the cost of the magnet material, a cut is formed at one or a plurality of intermediate portions of the circumferential direction of each of the magnet plates 12A and 12B. The gap between the magnet plates can also be used. And Figure 7 reveals its example 8 -16-201217757. Fig. 7 is a view showing a state in which both end portions of the respective magnet plates 12A and 12B of Fig. 1 are left as the magnet plate pieces 12A1, 12A2, and 12B1 and 12B2, and the intermediate portions are cut out to form the gaps 1 2Ad and 1 2Bd, respectively. Therefore, the magnet plate 12A is composed of a group of magnet plates 12A1 and 12A2, and the magnet plate 12B is composed of a group of magnet plates 12B1 and 12B2. Thereby, the amount of the magnet material required for the magnet plates 12A, 12B can be reduced. Furthermore, by arranging the magnet plates 1 2 A 1 , 12A2 , 12B1 , 12B 2 by the gaps as described above, the central angle of each of the arc-shaped magnet plates becomes smaller, and the width (radius) with respect to the length of the arc If the length of the direction is large enough, the circular magnet plate may be used without using an arc. In this case, the size and arrangement of the rectangles are determined such that the four corners of the rectangular shape do not extend beyond the inner peripheral surface and the outer peripheral surface of the magnetic substrate 11 and the yoke plates 13A and 13B. [Fifth Embodiment] The fifth embodiment is also the same as the embodiment of Fig. 7. As shown in Fig. 8, the magnet plates 12A and 12B are composed of a plurality of magnet plates 12A1, 12A2 and 1 2B1, 12B2, respectively. Alternatively, the gaps 12Ad and 12Bd may be formed. [Sixth embodiment] In the embodiment of Fig. 1, an example of a position detecting device having a ring-shaped rotor 1 is disclosed. However, it may be an arc shape as an annular shape. An example of this is disclosed in FIG. This example has an arc shape of 180° formed by cutting the rotor 10 of Fig. 1B by a track passing through the central axis Ox. The gap G system -17- 201217757 is not centered in the circumferential direction of the arc. Of course, as an arc, it is not necessary to be 18 0°', and it may be smaller than it. By thus providing the rotor 10 in an arc shape, the amount of the magnet material can be reduced, and the cost can be reduced. Similarly, even in the embodiment of Fig. 5, an arc-shaped rotator (not shown) cut out from the annular rotator 10 may be used. Further, as shown by a dotted line in Fig. 9, each of the magnet plates 1 2 A and 1 2 B is the same as the embodiment of Fig. 7, and is arranged in the circumferential direction with a gap of 1 2 A d and 1 2 B d. The group composition of the plurality of magnet plates may also be used. [Industrial Applicability] The present invention is applicable to position detection of a rotating member of an industrial machine and a linear movable member. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a perspective view of a first embodiment of the invention. Fig. 1B is a plan view of the first embodiment. Fig. 1C is a side view of the first embodiment. Fig. 2 is a block diagram for explaining a logic decision circuit for processing a magnetic sensor and its magnetic detection signal output. Fig. 3 is a view showing an example of a waveform of a magnetic detecting signal and a waveform of a position detecting signal obtained by logically determining a magnetic detecting signal. Fig. 4A is a graph comparing the simulation results of the magnetic flux density at the position of the magnetic sensor caused by the first embodiment and the prior art. Fig. 4B is an enlarged view of the vicinity of the gap G of Fig. 4A. -18- 8 201217757 Fig. 5 is a perspective view showing a second embodiment of the invention. Fig. 6 is a perspective view showing a third embodiment of the invention. Fig. 7 is a perspective view showing a fourth embodiment of the invention. Fig. 8 is a perspective view showing a fifth embodiment of the invention. Fig. 9 is a plan view showing a sixth embodiment of the invention. Figure 1 〇 A is a top view of a rotary encoder resulting from prior art. Fig. 10B is a perspective view of Fig. 10A. Figure 1 0 C is a side view of Figure 10 A. [Description of main component symbols] 1 0, 8 1 : Rotator 10': Straight-in body 1 1 : Magnetic substrate 12A1 to 2, 12B1 to 2, 12A to D: Magnet plate 1 3 A to D: Yoke plate 1 4 : Magnetic sensor 1 4 S, 8 4 : Magnetic field detection direction 20: Logic decision circuit 8 1 A~8 1 D : Fan-shaped magnet plate 8 2, 8 2 a~8 2 c : Magnetic sensor 1 2 A d , 1 2 B d, D: interval G: gap
Ox :旋轉軸 VB :恆定電壓 -19- 201217757 VM :磁性檢測訊號 SD :位置檢測訊號 + Vth、-Vth :臨限値電壓 dA :磁滯寬度 ⑧ -20-Ox : Rotary axis VB : Constant voltage -19- 201217757 VM : Magnetic detection signal SD : Position detection signal + Vth, -Vth : Restricted voltage d dA : Hysteresis width 8 -20-