(1 ) 1257476 玖、發明說明 【發明所屬之技術領域】 本發明，是有關非圓形齒輪以及採用非圓形齒輪的體 積式流量計。 【先前技術】 習知，非圓形齒輪是使用體積式流量計或泵等。非圓 形齒輪之中間距曲線是由p =a/ ( l-bc〇S2e)表示的橢圓形 齒輪，其由旋轉所產生的嚙合壓力角的變化大，且，爲了 避免長徑部的齒形的切下等的干渉而使齒形模組縮小並使 齒數増多。在此，P :動徑、a :相似係數、b :偏平度、 Θ :偏角。 不使旋轉的嚙合壓力角的變化增大的技術，如一種橢 圓形齒輪（例如，日本特公平1 - 3 9 0 5 2號公報參照）。橢 圓形齒輪，是藉由使形成於齒輪的間距曲線上的齒形曲線 的實質部隨時朝旋轉中心方向地形成齒，減少嚙合壓力角 的變化且絕對不會成爲負的非圓形齒輪。此橢圓形齒輪， 因每一旋轉的吐出量大，可以維持長期間高精度，所以多 使用作爲體積式流量計的旋轉件。 且，作爲防止漸開線齒形的切下的技術，習知就有特 殊的轉位變形的橢圓齒輪（例如，市川時雄著、「齒輪 泵」、日刊工業新聞社、1 962年8月20日發行、p.165_ 1 6 6參照）。此變形橢圓齒輪，其實用化的例：齒數爲i 4 枚，組入已知的精工（七一〕一）泵的泵內，且位置於齒 -4- (2) 1257476 輪的長徑的先端（頂）的泵內壁的密封部分，在長軸方向 的兩端各由1個齒構成。 且，此變形橢圓齒輪，雖是無切下的齒形，但是具有 過多部分。在此’過多部分’是指齒形從連結間距曲線及 各齒形的嚙合齒面的接點及橢圓中心的直線超出的部分。 一方面，非圓形齒輪多是由金屬材料所製造，也有因 成本而由便宜的樹脂成型所製造。但是，考慮樹脂成型的 非圓形齒輪的情況，需要提高供成型性提高用的齒形強 度，因此必需加大齒形模組並減少齒數。 減少齒數的技術，是如上述市川時雄著「齒輪泵」的 變形橢圓齒輪，但此齒輪，是具有過多部分的齒形。由樹 脂成型所產生的橢圓齒輪，是樹脂注入固定時藉由在鎊型 中向橢圓中心方向使樹脂收縮形成，但是在過多部分中因 爲無收縮方向所以不會收縮而在其部分容易產生缺陷。因 此要求設計成過多部分不存在的齒形。 且，非圓形齒輪，如具有突起齒形的突起齒輪（例 如，特別是公昭62-3 8 8 5號公報參照）。特別是日本公昭 62-3885號公報的非圓形齒輪式流量計，其目的是提筒作 爲小型流量計的測量精度及每1旋轉的吐出量，具備使長 徑部的齒形突起且將與其突起部分嚙合的缺口設在短徑部 的非圓形齒輪。 如上述，使非圓形齒輪由樹脂成型製造的情況時’需 要提高樹脂齒形的強度，因此需要加大模組，但是爲了加 大模組，因齒輪整體的大小的制限而需減少齒數。但是’ -5- (3) 1257476 對於非圓形齒輪藉由只爲了防止切下使工具壓力角加大而 藉由齒形傾斜來加大齒輪整體的模組的比率的話，需要將 過多部分的齒形由樹脂成型來成形，其結果其部分會產生 缺陷。 特別是日本公昭62 - 3 8 8 5號公報的流量計中，實際設 計·製造該旋轉件的軸是固定於外殼（此爲計量室）側的 突起齒輪的情況時，頂部分的突起是需與模組成比例地加 大，因此嚙合於其突起的凹部的凹陷也變大，而使應設置 於突起齒輪的中心的軸承的***區域無法確保。進一步， 特別是即使是日本公昭62- 3 8 8 5號公報的突起齒輪，對於 使無過多部分且減少齒數的技術並無揭示。因此，此突起 齒輪，其齒數因爲多，所以需縮小其頂部分的突起及外殼 的內壁的密封長（密封寬）。 密封長較短的齒輪，會使來自頂部的漏出量多，不適 合設置於體積式流量計。 進一步，日本特公平卜3 905 2號公報等的習知技術的 非圓形齒輪，爲了減少齒數且防止過多部分，是藉由使工 具壓力角加大至尖角限度爲止使齒形傾斜且尖角地設計， 但是其非圓形齒輪及設置其的外殼的內壁的密封部分是幾 乎無，所以密封性無法確保，且隨著嚙合齒輪的旋轉會在 尖角部分使磨耗激烈。因此，特別是頂部或其附近的齒 形，無法設計成至尖角限度爲止地彎曲。 且，不限定於樹脂成型的非圓形齒輪，即使由例如金 屬等所形成的非圓形齒輪，至尖角限度爲止尖角的齒形及 -6 - (5) 1257476 部用的形狀的凸部、及具有與該非圓形齒輪相同的削去非 圓形齒輪的前述齒部的形狀的凹部。 申請專利範圍第3項的第3技術手段，是對於第1或 是第2技術手段，其中’前述齒形曲線是由前述外殻的該 非圓形齒輪的設置場所及內壁的大小決定，前述形狀，是 將前述凹部由配合前述外殼的內壁的圓弧所埋沒。 申請專利範圍第4項的第4技術手段，是對於第1或 是第2技術手段，其中，前述齒形曲線是由前述外殻的該 非圓形齒輪的設置場所及內壁的大小決定，前述形狀，是 將前述凹部由配合前述外殼的內壁的曲線所埋沒，該埋沒 的曲線，是當與該非圓形齒輪相同地削去非圓形齒輪的前 述齒部的凹部的底嚙合時相互接觸。 申請專利範圍第5項的第5技術手段，是對於第1或是2 的技術手段，其中，前述齒形曲線，其齒數爲1 4或是1 8 時，其結果，實際上的齒數是各別成爲1 〇或是1 4。 申請專利範圍第6項的第6技術手段，是對於第1或 是2的技術手段，其中，該非圓形齒輪的間距曲線，是滿 足滾動接觸條件的單一的閉曲線或是組合數種類的閉曲 線。 申請專利範圍第7項的第7技術手段，是對於第1或 是2的技術手段，其中，該非圓形齒輪，是由樹脂形成。 申請專利範圍第8項的第8技術手段，是對於第1或 是2的技術手段，其中，前述外殼，是體積式流量計的計 量室。 -8 - (8) 1257476 旋轉件所吐出的被測量流體的流量的體積式流量計’詳述 有關於由一對的旋轉件嚙合設置可能的非圓形齒輪。 第2圖，是本發明的一實施例的非圓形齒輪的一結構 例的圖，第 2圖（A ) 、 ( B )，是顯示使一對的非圓形 齒輪的嚙合對應其旋轉位置的圖。圖中，3 0是第一非圓 形齒輪，3 1〜3 7、4 1〜4 7分別是第一非圓形齒輪的第1〜 第1 4的齒形，3 3 a、3 3 b、3 3 c分別是第3齒形的嚙合齒 面、非嚙合齒面、齒頂，36a、36b、36c分別是第6齒形 的嚙合齒面、非嚙合齒面、齒頂，38、48是第一非圓形 齒輪的凹部，3 9、49是第一非圓形齒輪的凸部，5 0是第 二非圓形齒輪，5 1〜5 7、6 1〜6 7分別是第二非圓形齒輪 的第 1〜第 14的齒形，58、68是第二非圓形齒輪的凹 部，59、69是第二非圓形齒輪的凸部，01是第一非圓形 齒輪的中心，〇 2是第二非圓形齒輪的中心。 本發明的一實施例的非圓形齒輪3 0、5 0 (相當於第1 圖的旋轉件23、27)，是在外殼內呈一對設置的非圓形 齒輪，具有以下的齒形曲線。在此，外殼，是相當於體積 式流量計的計量室。在此，非圓形齒輪3 0、5 0是由樹脂 (由樹脂塑模等成型）所形成，不只可便宜製造，並成爲 可活用：減少齒數’且因朝旋轉中心方向的收縮缺陷所產 生的過多部分不會形成的本發明的特徵部分的形態。但 是，當然，非圓形齒輪3 0、5 0不只樹脂成型，由切削金 屬的加工等各式各樣的材料、製法形成也可能。 此齒形曲線’是使間距曲線呈橢圓形成的齒形曲線， -11 - (9) 1257476 齒數爲4n + 2枚（n=l、2、3、…），長軸上的兩端爲齒溝 (例如齒形3 4及齒形3 5之間的齒溝）’短軸上的兩端爲 齒頂（例如齒形3 1的齒頂）、及齒形3 1〜3 7、4 1〜4 7 (非圓形齒輪5 0的情況，齒形5 1〜5 7、6 1〜6 7 )爲基本 的曲線。然而，在第2圖中例示n = 3共計1 4枚的情況。 且，減小η的情況，或者是更小型的齒輪的情況時可縮小 間距曲線的扁平度，使接近於圓形即可。且，在此間距曲 線是由橢圓作說明，但是非圓形齒輪的間距曲線，是不限 定於橢圓形齒輪的間距曲線p =a/ ( l-bc〇S2 0 )的表示， 滿足滾動接觸條件的單一的閉曲線或是組合數種類的閉曲 線即可。 有關於齒數，考慮埋沒部分及切削部分前的齒數，即 作爲原來的齒形曲線的齒形的數，是鑑於埋沒部分及切削 部分有6個以上的數（4 n + 2 )即可，並考慮後述埋沒部分 及切削部分的話，最終完成的齒數是4n-2枚。實際上， 原來的齒形曲線，其齒數是1 4或是1 8，最終的齒數各別 是成爲1 〇或是1 4的結構較佳。 進一步此基本齒形曲線，是其嚙合齒面爲漸開線曲線 且非嚙合齒面爲擺線曲線地形成的齒形曲線。舉例第一非 圓形齒輪3 0的第3齒形3 3說明的話，嚙合齒面3 3 a爲漸 開線曲線，且挟持齒頂3 3 c地使非嚙合齒面3 3 b成爲擺線 曲線。進一步’此齒形曲線，是依據切下限界及尖角限度 設定各齒形的漸開線曲線的工具壓力角。然而，非嚙合齒 面是擺線曲線’工具壓力角是零，且，間距曲線的外側的 -12- (10) 1257476 非嚙合齒面是滾動於間距曲線的外側時所形成的外擺線， 間距曲線的內側的非嚙合齒面是滾動於間距曲線的內側時 所形成的內擺線。 而且，非圓形齒輪30、50，是依據上述基本齒形曲 線，對於其包含長軸上的兩端的齒溝（例如齒形3 4及@ 形3 5之間的齒溝）的凹部，是設計成具有可埋沒挾持_ 齒溝的2個齒形（例如齒形3 4及齒形3 5 )間的凹部的_ 狀。在第2圖中，是顯示具有將例如齒形3 4及齒形3 5 _ 的凹部由曲線所埋沒的凸部3 9的形狀，此凸部3 9是使_ 凹部由配合外殼的內壁的圓弧所埋沒。然而，這時，齒g 曲線是依據外殼的非圓形齒輪的設置場所及內壁的大小_ 定。且，例如，成爲凸部3 9的根部的齒形3 4及齒形3 Ο 的嚙合齒面側是保持原齒形。 進一步，非圓形齒輪3 0、5 0，其基本齒形曲線，錢 有實際上被削去的短軸上的兩端的齒頂（例如齒形3 1 % 園頂）的齒部的形狀。在第2圖中，是顯不被削去如齒_ 3 1的齒頂的齒部（相當於齒形3 1 )的具有凹部3 8的_ 狀。因此，基本齒形曲線的齒數爲4n + 2枚的話，最終白$ 實際齒形曲線的齒數是成爲4n-2枚。 而且，非圓形齒輪3 0及非圓形齒輪5 0，是使具有_ 埋沒2個齒形（例如齒形34及齒形3 5 )間的凹部用的_ 狀的凸部39、及具有被削去的非圓形齒輪50的齒部（_ 當於齒形5 1 )的形狀的凹部5 8，相互嚙合的結構，同g 地，使非圓形齒輪3 0的凹部3 8及非圓形齒輪5 0的凸純 -13- (11) 1257476 59，或是非圓形齒輪30的凸部49及非圓形齒輪50的凹 部68，或是非圓形齒輪30的凹部48及非圓形齒輪50的 凸部6 9，相互嚙合的結構。 然而，在此的嚙合，皆非由凹部及凸部的中心彼此的 接觸，舉例凸部3 9及凹部5 8的嚙合的例的話，如第2 (B )圖所示’非圓形齒輪3 0的長徑及非圓形齒輪5 0的 短徑一致時，凸部3 9及凹部5 8不相互接觸，凸部3 9的 原來的齒形3 5的嚙合齒面的頂點是與非圓形齒輪5 〇的齒 形6 7的嚙合齒面相互接觸，朝箭頭的旋轉方向旋轉，接 著，凸部3 9的原來的齒形3 4的嚙合齒面的頂點是與非圓 形齒輪5 0的第2齒形5 2的嚙合齒面接觸而旋轉。因此， 如第2圖所示的一對的非圓形齒輪30、50，依據來自一 方的齒輪的軸的旋轉力是無法使其他方的齒輪旋轉超過1 旋轉以上。但是，一對的非圓形齒輪3 0、5 0，在如體積 式流量計，藉由被測量流體所產生的流動力按壓位置於雙 方的齒輪的外側的部分的使用形態，朝第2圖的箭頭的旋 轉方向旋轉是可能，其切換點是因慣性的關係而位在頂附 近（凸部3 9等）。 且，在其他的齒形，是例如’非圓形齒輪3 0的第6 齒形36，如第2(A)圖所示，齒形36的嚙合齒面36a是 與非圓形齒輪5 0的齒形6 6的嚙合齒面側接觸嚙合，接 著，凸部39的齒形35的嚙合齒面是與非圓形齒輪50的 齒形67的嚙合齒面側接觸嚙合，朝箭頭的旋轉方向旋 轉。 -14- (12) 1257476 第3圖乃至第6圖，是說明設計第2圖的非圓形齒輪 時所考慮的點的一連的結構圖，任一的圖皆只有非橢圓形 齒輪的W4，第6圖是顯示第2圖的非圓形齒輪的1/4。 圖中，L是齒形曲線，La是嚙合齒面，Lb是非嚙合齒 面，Lc是齒頂，P是間距曲線，R是來自間距曲線的中心 的放射線，T是連結齒形的齒頂的曲線，b是連結齒形的 底的曲線’其他’弟6圖是使用與第2圖相同符號顯 示。 第3圖的齒形曲線L，是間距曲線P形成橢圓的齒形 曲線，齒數爲4n + 2枚（在此14枚），嚙合齒面La爲漸 開線曲線，非嚙合齒面Lb爲擺線曲線及齒形曲線。此齒 形曲線L，在由放射線R區切的領域（黑色部分）是多存 在過多部分。第3圖的齒形曲線L，是長軸上的兩端爲齒 頂，短軸上的兩端爲齒溝，在此設計中，只可設定切下不 會產生程度的工具壓力角，即使依據其設定長軸方向使齒 形傾斜，也無法消解過多部分。 在樹脂成型等中，因朝旋轉中心方向的收縮而會在過 多部分中產生缺陷，所以使過多部分不會形成地使頂齒形 設成2枚（長軸上的兩端爲齒溝）。即，如第4圖的齒形 曲線L所示，相反地長軸上的兩端爲齒溝，短軸上的兩端 爲齒頂，進一步依序如第4、5圖的齒形曲線L所示，使 過多部分減少地讓各齒形朝長軸方向傾斜。這時，嚙合齒 面L a雖是使用漸開線曲線，但是爲了減少嚙合壓力角的 變化，而要求其工具壓力角爲至切下限界爲止且嚙合壓力 -15- (13) 1257476 角不爲負的程度。但是，即使第5圖的齒形曲線L ’在最 接近長軸的齒形因爲存在過多部分，所以相同的噴合齒面 La雖是使用漸開線曲線，但是爲了減少嚙合壓力角的變 化而使其工具壓力角是由切下限界及尖角限度求得。然 而，使有利於嚙合齒面La的工具壓力角設定地’使非嚙 合齒面Lb是使用擺線曲線。在此，供過多部分的消解的 最高傾斜率的齒形，因爲是接近於長軸兩端的齒形’所以 藉由使長軸上的兩端成爲齒溝（凹），就可使供防止切下 用的工具壓力角更大（最大尖角限度爲止）地設定。 即，如第6的齒形曲線L圖所示，過多部分將完全消 除爲止使各齒形朝長軸方向傾斜，因只是使至尖角限度爲 止地形成尖角，所以齒形的齒頂Lb (特別是在齒形3 4的 齒頂）是太尖，而爲了消解此尖角而連 齒形34的齒頂 及第2圖的齒形3 5的齒頂。鑑於由連 此齒頂所產生的 凸部3 9的嚙合，而削去短徑上的齒形，形成凹部3 8。然 而，各連結齒形的齒頂的曲線T、及連結各齒形的底部的 曲線，是成爲與間距曲線平行的曲線。 使頂齒形的先端（凸部3 9 )形成與外殼並行的圓弧 的1個齒，去除一方的短徑部的齒的上述的設計，不只是 加大齒形模組且減少齒數而可堅牢，更可防止尖的頂部分 的密封長不足而可提高頂部的密封性。且，如第4圖乃至 第6圖所示，在基本齒形曲線的長軸上具有齒溝的設計， 對於過多部分形成的回避也有効。 依據實施例的非圓形齒輪，嚙合壓力角的變化減少， -16- (14) 1257476 有利於嚙合齒面的工具壓力角設定’不會形成過多部分且 齒數減少，或設置於外殼內時可使外殼的內壁的密封性充 分確保，且，即使軸固定於外殼的情況’也可確保軸承的 ***區域。進一步’此非圓形齒輪’因爲是使齒形模組整 體變大而堅牢，所以因可以由少齒數所構成而對於樹脂成 型也有効。進一步，具備上述的非圓形齒輪的體積流量 計，是可實現堅牢旦高精度，且非圓形齒輪是由樹脂成型 的情況時可以實現便宜的產品。 馨 第7圖，是顯示本發明的其他的實施例的非圓形齒輪 的一結構例的圖，第7圖（A ) 、 （ B ) ’是使一對的非 圓形齒輪的嚙合對應其旋轉位置顯示的圖。圖中’ 3 0 ’是 第一非圓形齒輪，39’、4W是第一非圓形齒輪的凸部’ 50’ 是第二非圓形齒輪，59’、69’是第二非圓形齒輪的凸部’ 其他，與第2圖相同部位附加相同符號省略其說明。 由第7圖所例示的實施例的非圓形齒輪’是對於具備 第2圖乃至第6圖所例示的非圓形齒輪及其齒輪的體積式 β 流量計（第1圖參照），使凸部（第2圖的凸部3 9、 4 9、5 9、6 9 )的形狀變形者，其變形部分以外的說明包含 其效果也省略。 本實施例的非圓形齒輪30’（ 50’），是將凸部39’、 4 9’（ 5 9’、69’），由配合外殼的內壁的曲線所埋沒，且， 埋沒的曲線，是與削去的非圓形齒輪5 0 ’（ 3 0 ’）的齒部的 凹部5 8、6 8 ( 3 8、4 8 )的底嚙合時相互接觸。然而，這 時，齒形曲線是依據外殼的非圓形齒輪的設置場所及內壁 -17- (15) 1257476 的大小決定。且，在第7圖中，例如，與成爲凸部3 9，的 根的齒形3 4及齒形3 5的嚙合齒面側雖是變形原來的齒形 的曲線，但是成爲凸部3 9 ’的根的齒形3 4及齒形3 5的嚙 合齒面側是保持原來的齒形也可以。依據本實施例的非圓 形齒輪，相比於第1圖乃至第6圖所說明的實施例，設置 於體積式流量計的情況時，藉由從嚙合壓力角的關係使密 閉現象緩和，可減輕壓力損失，可配合頂部的密封性提高 而提高測量精度。 0 【圖式簡單說明】 第1圖，本發明的一實施例的非圓形齒輪將具備體積 式流量計的一結構例的圖。 第2圖，是本發明的一實施例的非圓形齒輪的一結構 例的圖。 第3圖，是說明設計第2圖的非圓形齒輪時的考慮點 的一連的結構圖。 籲 第4圖，是說明設計第2圖的非圓形齒輪時的考慮點 的一連的結構圖。 第5圖，是說明設計第2圖的非圓形齒輪時的考慮點 的一連的結構圖。 第6圖，是說明設計第2圖的非圓形齒輪時的考慮點 的一連的結構圖。 第7圖，是本發明的其他的實施例的非圓形齒輪的一 結構例的圖。 -18- (16) 1257476 【主要元件符號說明】 10 流量計 1 1外框 12端面板 1 5磁性檢測器 2 0計量室 21流入□ φ 2 2 流出口 2 3旋轉件 2 3 b端面 2 4旋轉軸 25磁鐵 2 7旋轉件 3 0非圓形齒輪 30’非圓形齒輪 · 3 1〜3 7 齒形 3 3 a 嚙合齒面 3 3 b 非嚙合齒面 3 3c 齒頂 3 6 a嚙合齒面 3 8凹部 39凸部 3 9 ’凸部 -19- (17) 1257476 48凹部 4 9凸部 4 9 ’凸部 5 0 非圓形齒輪 5 0’非圓形齒輪 5 1〜5 7 齒形(1) 1257476 发明Invention Description [Technical Field] The present invention relates to a non-circular gear and a volumetric flowmeter using a non-circular gear. [Prior Art] Conventionally, a non-circular gear is a volumetric flow meter or a pump or the like. The pitch curve among the non-circular gears is an elliptical gear represented by p = a / ( l - bc 〇 S2e), which has a large change in the meshing pressure angle caused by the rotation, and, in order to avoid the tooth profile of the long diameter portion The cutting of the cognac makes the toothed module shrink and the number of teeth is increased. Here, P: dynamic path, a: similarity coefficient, b: flatness, Θ: declination. A technique which does not increase the variation of the meshing pressure angle of the rotation, such as an elliptical gear (for example, Japanese Patent Publication No. Hei. No. Hei. The elliptical gear is formed by making the substantial portion of the tooth profile formed on the pitch curve of the gear form the tooth toward the center of rotation at any time, thereby reducing the change in the meshing pressure angle and never becoming a negative non-circular gear. Since the elliptical gear has a large discharge amount per rotation and can maintain high precision for a long period of time, a rotary member as a volumetric flowmeter is often used. Further, as a technique for preventing the cutting of the involute profile, there is a special elliptical gear that has a special index deformation (for example, Ichikawa Yuki, "Gear Pump", Nikkan Kogyo Shimbun, August 20, 962 Japanese issue, p.165_ 1 6 6 reference). This anamorphic elliptical gear is a practical example: the number of teeth is i 4 pieces, which is incorporated into the pump of the known Seiko (July 1) pump, and is located in the long diameter of the tooth -4- (2) 1257476 wheel. The sealing portion of the inner wall of the tip end (top) is composed of one tooth at each end in the longitudinal direction. Moreover, the deformed elliptical gear has an uncut shape but has a large portion. Here, the "excessive portion" means a portion in which the tooth shape exceeds a line connecting the pitch curve and the contact surface of each tooth-shaped tooth surface and the straight line of the ellipse. On the one hand, non-circular gears are mostly made of metal materials, and are also manufactured by inexpensive resin molding due to cost. However, in consideration of the case of a resin-formed non-circular gear, it is necessary to increase the tooth profile strength for improving the moldability, so it is necessary to increase the tooth profile module and reduce the number of teeth. The technique for reducing the number of teeth is a deformed elliptical gear of the "gear pump" of the above-mentioned Ichikawa, but this gear has a tooth shape having an excessive portion. The elliptical gear produced by the resin molding is formed by shrinking the resin in the direction of the ellipse in the pound type when the resin is injected and fixed, but does not shrink in the excessive portion because there is no contraction direction, and defects are likely to occur in the portion. Therefore, it is required to design a tooth shape that does not exist in a large portion. Further, a non-circular gear such as a projecting gear having a protruding tooth shape (see, for example, Japanese Patent Publication No. 62-3 8 8 5). In particular, the non-circular gear type flowmeter of the Japanese Patent Publication No. 62-3885, the purpose of which is to provide a toothed projection of a long diameter portion as a measurement accuracy of a small flowmeter and a discharge amount per one rotation, and The notch in which the protruding portion is engaged is provided in the non-circular gear of the short diameter portion. As described above, when the non-circular gear is molded from a resin, it is necessary to increase the strength of the resin tooth shape. Therefore, it is necessary to enlarge the module. However, in order to enlarge the module, it is necessary to reduce the number of teeth due to the limitation of the overall size of the gear. However, '-5- (3) 1257476 For the non-circular gear, it is necessary to increase the ratio of the module of the gear as a whole by merely tilting the tooth shape to prevent the tool from increasing the pressure angle. The tooth shape is formed by resin molding, and as a result, a part thereof is defective. In particular, in the flow meter of the Japanese Patent Publication No. 62-38 8 5, when the shaft for actually designing and manufacturing the rotary member is a projection gear fixed to the side of the outer casing (this is a measuring chamber), the projection of the top portion is required. In addition to the mold composition, the depression of the concave portion that is engaged with the projection thereof is also increased, and the insertion region of the bearing to be provided at the center of the projection gear cannot be secured. Further, in particular, even the projection gear of the Japanese Patent Publication No. 62-38 8 5 does not disclose a technique for reducing the number of teeth without excessive portions. Therefore, since the number of teeth of the projecting gear is large, it is necessary to reduce the seal length (sealing width) of the projection of the top portion and the inner wall of the outer casing. Sealing the shorter gear will result in more leakage from the top and is not suitable for volumetric flowmeters. Further, in the non-circular gear of the prior art such as Japanese Patent Publication No. 3 905 2, in order to reduce the number of teeth and prevent excessive portions, the tooth shape is inclined and pointed by increasing the tool pressure angle to the sharp angle limit. The design is angular, but the sealing portion of the non-circular gear and the inner wall of the outer casing on which the casing is disposed is almost absent, so the sealing property cannot be ensured, and the wear of the meshing gear is intense at the sharp corner portion. Therefore, in particular, the tooth shape at or near the top cannot be designed to bend to the limit of the sharp corner. Further, it is not limited to a non-circular gear that is molded by a resin, and a non-circular gear formed of, for example, a metal, a tooth shape of a sharp angle to a sharp angle limit, and a convex shape of a shape of a -6 - (5) 1257476 part. And a recess having the same shape as the tooth portion of the non-circular gear that is the same as the non-circular gear. The third technical means of the third aspect of the patent application is the first or second technical means, wherein the 'tooth profile is determined by the installation location of the non-circular gear of the outer casing and the size of the inner wall. The shape is such that the concave portion is buried by an arc of an inner wall that fits the outer casing. The fourth technical means of the fourth aspect of the invention is the first or second technical means, wherein the tooth profile is determined by the installation location of the non-circular gear of the outer casing and the size of the inner wall. The shape is such that the concave portion is buried by a curve matching the inner wall of the outer casing, and the buried curve is in contact with each other when the bottom portion of the concave portion of the tooth portion of the non-circular gear is cut off in the same manner as the non-circular gear. . The fifth technical means of the fifth aspect of the patent application is the first or second technical means, wherein the tooth profile has a number of teeth of 14 or 18, and as a result, the actual number of teeth is Don't be 1 〇 or 1 4. The sixth technical means of claim 6 is a technical means for the first or the second, wherein the pitch curve of the non-circular gear is a single closed curve satisfying the rolling contact condition or a combined number of closed curves. The seventh technical means of claim 7 is the first or second technical means, wherein the non-circular gear is formed of a resin. The eighth technical means of claim 8 is the first or second technical means, wherein the outer casing is a measuring chamber of a volumetric flowmeter. -8 - (8) 1257476 Volumetric flowmeter for the flow rate of the fluid to be measured which is ejected by the rotary member' detailed description A possible non-circular gear is provided for engagement by a pair of rotating members. Fig. 2 is a view showing a configuration example of a non-circular gear according to an embodiment of the present invention, and Figs. 2(A) and (B) show the engagement of a pair of non-circular gears corresponding to their rotational positions. Figure. In the figure, 30 is the first non-circular gear, and 3 1 to 3 7 and 4 1 to 4 7 are the first to 14th tooth shapes of the first non-circular gear, respectively, 3 3 a, 3 3 b 3 3 c are the meshing tooth surface of the 3rd tooth shape, the non-engaging tooth surface, and the tooth top, respectively, 36a, 36b, 36c are the meshing tooth surface of the 6th tooth shape, the non-engaging tooth surface, the tooth top, 38, 48 It is a concave portion of the first non-circular gear, 39, 49 is a convex portion of the first non-circular gear, 50 is a second non-circular gear, and 5 1 to 5 7 and 6 1 to 6 7 are respectively second The first to fourteenth tooth shapes of the non-circular gear, 58, 68 are recesses of the second non-circular gear, 59, 69 are convex portions of the second non-circular gear, and 01 is the first non-circular gear. Center, 〇 2 is the center of the second non-circular gear. The non-circular gears 30 and 50 (corresponding to the rotating members 23 and 27 of the first drawing) according to an embodiment of the present invention are non-circular gears provided in a pair in the outer casing, and have the following tooth profile. . Here, the outer casing is a measuring chamber equivalent to a volumetric flow meter. Here, the non-circular gears 30 and 50 are formed of a resin (molded by a resin mold or the like), and can be manufactured not only inexpensively but also usable: a reduction in the number of teeth and a shrinkage defect in the direction of the center of rotation. The excessive portion does not form the form of the characteristic portion of the present invention. However, of course, the non-circular gears 30 and 50 are not only resin-molded, but may be formed by various materials and manufacturing methods such as machining of cutting metals. This tooth profile 'is a tooth profile curve that makes the pitch curve elliptical, -11 - (9) 1257476 The number of teeth is 4n + 2 pieces (n = l, 2, 3, ...), and the ends on the long axis are teeth The groove (for example, the groove between the tooth shape 34 and the tooth shape 3 5) is a tooth top (for example, a tooth top of the tooth shape 3 1), and a tooth shape 3 1 to 3 7 , 4 1 ~4 7 (in the case of non-circular gears 50, tooth profiles 5 1 to 5 7 , 6 1 to 6 7 ) are basic curves. However, in the second figure, a case where n = 3 totals 14 pieces is exemplified. Further, in the case of reducing η or in the case of a smaller gear, the flatness of the pitch curve can be made small so as to be close to a circle. Moreover, the pitch curve is illustrated by an ellipse, but the pitch curve of the non-circular gear is not limited to the pitch curve p = a / ( l - bc 〇 S2 0 ) of the elliptical gear, and satisfies the rolling contact condition. A single closed curve or a combination of several types of closed curves can be used. Regarding the number of teeth, considering the number of teeth before the buried portion and the cutting portion, that is, the number of the tooth shapes as the original tooth profile curve is that the buried portion and the cutting portion have six or more numbers (4 n + 2 ), and When the buried portion and the cut portion are described later, the number of finished teeth is 4n-2 pieces. In fact, the original tooth profile has a number of teeth of 14 or 18. The final number of teeth is preferably a structure of 1 〇 or 14 . Further, the basic tooth profile is a tooth profile curve in which the meshing tooth surface is an involute curve and the non-engaging tooth surface is a cycloid curve. For example, if the third tooth shape 3 3 of the first non-circular gear 30 is illustrated, the meshing tooth surface 3 3 a is an involute curve, and the non-engaging tooth surface 3 3 b is made to be a cycloid. curve. Further, the tooth profile curve is a tool pressure angle for setting the involute curve of each tooth shape based on the lower limit boundary and the sharp angle limit. However, the non-intermeshing tooth surface is a cycloid curve 'tool pressure angle is zero, and the outer side of the pitch curve -12- (10) 1257476 non-intermeshing tooth surface is the outer cycloid formed when rolling outside the pitch curve, The non-engaging tooth surface on the inner side of the pitch curve is a hypocycloid formed when rolling on the inner side of the pitch curve. Further, the non-circular gears 30, 50 are recesses according to the basic tooth profile curve for the grooves including the both ends on the long axis (for example, the grooves between the tooth shape 34 and the @-shaped 35). It is designed to have a shape of a recess between two tooth shapes (for example, the tooth shape 34 and the tooth shape 3 5 ) that can be buried. In Fig. 2, the shape of the convex portion 39 having a concave portion in which the tooth shape 34 and the tooth shape 3 5 _ are buried by a curve is shown, and the convex portion 39 is such that the concave portion is made by the inner wall of the fitting outer casing. The arc is buried. However, at this time, the tooth g curve is determined according to the installation place of the non-circular gear of the outer casing and the size of the inner wall. Further, for example, the tooth surface 34 of the root portion of the convex portion 39 and the meshing tooth surface side of the tooth shape 3 是 are maintained in the original tooth shape. Further, the non-circular gears 30, 50 have a substantially tooth profile, and the money has the shape of the tooth portions of the tooth tips (e.g., the tooth shape 3 1 % dome) on both ends of the short axis that are actually scraped. In Fig. 2, the tooth portion (corresponding to the tooth shape 3 1 ) of the addendum such as the tooth _ 3 1 is _ shaped with the concave portion 38. Therefore, if the number of teeth of the basic tooth profile is 4n + 2, the number of teeth of the final white $ actual tooth profile is 4n-2 pieces. Further, the non-circular gear 30 and the non-circular gear 50 are _-shaped convex portions 39 having _ buried recesses between the two tooth shapes (for example, the tooth shape 34 and the tooth shape 35), and The concave portion 5 8 of the shape of the tooth portion (_ in the tooth shape 5 1 ) of the cut non-circular gear 50 is meshed with each other, and the concave portion 38 of the non-circular gear 30 is not The convex pure 13-(11) 1257476 59 of the circular gear 50, or the convex portion 49 of the non-circular gear 30 and the concave portion 68 of the non-circular gear 50, or the concave portion 48 of the non-circular gear 30 and the non-circular shape The convex portion 6 of the gear 50 is engaged with each other. However, the meshing here is not the contact between the centers of the concave portion and the convex portion, and for example, the example of the engagement of the convex portion 39 and the concave portion 58 is as shown in the second (B) diagram. When the long diameter of 0 and the short diameter of the non-circular gear 50 are the same, the convex portion 39 and the concave portion 58 are not in contact with each other, and the apex of the meshing tooth surface of the original tooth shape 35 of the convex portion 39 is non-circular. The meshing tooth faces of the toothed shape of the gear 5 〇 are in contact with each other and rotate in the direction of rotation of the arrow. Then, the apex of the meshing tooth surface of the original tooth shape 34 of the convex portion 39 is a non-circular gear 5 0 The meshing tooth surfaces of the second tooth form 52 are rotated in contact with each other. Therefore, the pair of non-circular gears 30 and 50 shown in Fig. 2 cannot rotate the other gears by more than one rotation depending on the rotational force of the shaft from one of the gears. However, in the case of a volumetric flowmeter, the pair of non-circular gears 30 and 50 are pressed by the flow force of the fluid to be measured, and the position of the outer portion of the gears is pressed to the second figure. It is possible to rotate the direction of rotation of the arrow, and the switching point is located near the top due to the relationship of inertia (the convex portion 39, etc.). Further, in other tooth shapes, for example, the sixth tooth profile 36 of the non-circular gear 30, as shown in the second (A) diagram, the meshing tooth surface 36a of the tooth profile 36 is a non-circular gear 50. The meshing flank side of the tooth shape 66 is in contact engagement, and then the meshing tooth surface of the tooth shape 35 of the convex portion 39 is in contact with the meshing flank side of the tooth shape 67 of the non-circular gear 50, toward the direction of rotation of the arrow. Rotate. -14- (12) 1257476 Fig. 3 to Fig. 6 are diagrams showing a series of structural points considered when designing the non-circular gear of Fig. 2, and any of the figures only has W4 of a non-elliptical gear. Fig. 6 is a view showing 1/4 of the non-circular gear of Fig. 2. In the figure, L is a tooth profile curve, La is a meshing tooth face, Lb is a non-engaging tooth face, Lc is a tooth tip, P is a pitch curve, R is a radiation from the center of the pitch curve, and T is a tooth top that joins the tooth profile. The curve, b is a curve connecting the bottom of the tooth shape, and the other figure 6 is displayed using the same symbol as in the second figure. The tooth profile curve L of Fig. 3 is a tooth profile curve in which the pitch curve P forms an ellipse, the number of teeth is 4n + 2 pieces (14 pieces here), the meshing tooth surface La is an involute curve, and the non-in meshing tooth surface Lb is a pendulum. Line curve and tooth curve. This tooth profile L has a large number of areas (black portions) cut by the radiation R region. The tooth profile curve L of Fig. 3 is that the two ends on the long axis are the tooth tips, and the two ends on the short axis are the tooth grooves. In this design, only the tool pressure angle at which the cutting does not occur can be set, even if The tooth shape is tilted according to the direction in which the long axis is set, and too much portion cannot be eliminated. In resin molding or the like, defects are generated in a large portion due to shrinkage in the direction of the center of rotation. Therefore, the top teeth are formed in two pieces so that the excessive portion is not formed (the both ends on the long axis are the grooves). That is, as shown by the tooth profile curve L of Fig. 4, on the opposite side, both ends of the long axis are tooth grooves, and both ends of the short axis are tooth tips, and further, the tooth profile curve L of Figs. 4 and 5 is sequentially followed. As shown, the excess portion is reduced so that the respective tooth shapes are inclined toward the long axis direction. At this time, although the meshing tooth surface La is an involute curve, in order to reduce the change of the meshing pressure angle, the tool pressure angle is required to be the cut-off lower limit boundary and the meshing pressure is -15-(13) 1257476. The angle is not negative. Degree. However, even if the tooth profile L' of the fifth figure has an excessive portion in the tooth shape closest to the long axis, the same spray tooth surface La uses an involute curve, but in order to reduce the change of the meshing pressure angle. The tool pressure angle is obtained by cutting the lower limit boundary and the sharp corner limit. However, the tool pressure angle which facilitates the meshing of the tooth flanks La is set such that the non-engaging tooth flanks Lb use a cycloidal curve. Here, the tooth shape of the highest inclination rate for the excessive portion of the digestion is close to the tooth shape at both ends of the long axis. Therefore, by making the both ends of the long axis into a groove (concave), it is possible to prevent cutting. The lower tool has a larger pressure angle (up to the maximum sharp angle limit). In other words, as shown in the sixth tooth profile L diagram, the tooth portions are inclined in the long axis direction until the excessive portion is completely eliminated, and the sharp corners are formed only to the limit of the sharp angle. Therefore, the tooth tip Lb is formed. (especially at the crest of the toothed shape 34) is too sharp, and in order to resolve the sharp corner, the crest of the toothed shape 34 and the crest of the toothed form 3 of Fig. 2 are connected. The recess 38 is formed in view of the engagement of the projections 39 formed by the crests and the tooth profile on the short diameter is cut. However, the curve T of each of the tooth tips and the curve connecting the bottoms of the respective teeth are parallel to the pitch curve. The tip end (protrusion 3 9 ) of the top tooth shape forms one tooth of an arc parallel to the outer casing, and the above-described design of removing the teeth of one short diameter portion is not only an increase in the tooth profile module but also a reduction in the number of teeth. It is firmer and prevents the sealing of the top portion of the tip from being insufficient to improve the sealing of the top. Further, as shown in Fig. 4 to Fig. 6, the design of the groove on the long axis of the basic tooth profile is effective for avoiding the formation of excessive portions. According to the non-circular gear of the embodiment, the variation of the meshing pressure angle is reduced, and -16-(14) 1257476 is advantageous for the tool pressure angle setting of the meshing tooth surface to not form an excessive portion and the number of teeth is reduced, or when it is disposed in the outer casing The sealing property of the inner wall of the outer casing is sufficiently ensured, and the insertion region of the bearing can be ensured even if the shaft is fixed to the outer casing. Further, since the non-circular gear is rigid in that the toothed module is made large as a whole, it can be formed by a small number of teeth and is also effective for resin molding. Further, the volume flow meter having the above-described non-circular gear can achieve a high precision and a non-circular gear can be realized by a resin. FIG. 7 is a view showing a configuration example of a non-circular gear according to another embodiment of the present invention, and FIGS. 7(A) and (B)′ are for the engagement of a pair of non-circular gears. Rotate the position of the map. In the figure, '30' is the first non-circular gear, 39', 4W is the convex portion of the first non-circular gear '50' is the second non-circular gear, and 59', 69' is the second non-circular The same portions as those in the second embodiment are denoted by the same reference numerals and the description thereof is omitted. The non-circular gear 'in the embodiment illustrated in Fig. 7 is a volumetric beta flowmeter (refer to Fig. 1) provided with the non-circular gears and the gears illustrated in Figs. 2 to 6 The shape change of the portion (the convex portions 3 9 , 4 9 , 5 9 , and 6 9 of the second drawing) is not described in addition to the description of the modified portion. The non-circular gear 30' (50') of the present embodiment is such that the convex portions 39', 4 9' (59', 69') are buried by the curve of the inner wall of the mating casing, and the buried curve It is in contact with each other when meshing with the bottoms of the recesses 5 8 , 6 8 ( 3 8 , 4 8 ) of the tooth portions of the cut non-circular gear 50 0 '( 3 0 '). However, at this time, the tooth profile is determined by the location of the non-circular gear of the outer casing and the size of the inner wall -17-(15) 1257476. In addition, in the seventh figure, for example, the meshing tooth surface side of the tooth shape 34 and the tooth shape 35 which is the root of the convex portion 39 is a curve which deforms the original tooth shape, but becomes a convex portion 39. It is also possible to maintain the original tooth shape on the meshing flank side of the root tooth shape 3 4 and the tooth shape 35. According to the non-circular gear of the present embodiment, in the case of the volumetric flowmeter as compared with the embodiment described in the first to sixth figures, the sealing phenomenon can be alleviated by the relationship of the meshing pressure angle. Reduces pressure loss and improves measurement accuracy with improved sealability at the top. [Brief Description of the Drawings] Fig. 1 is a view showing a configuration example of a volumetric flowmeter in a non-circular gear according to an embodiment of the present invention. Fig. 2 is a view showing a configuration example of a non-circular gear according to an embodiment of the present invention. Fig. 3 is a structural view showing a series of considerations when designing the non-circular gear of Fig. 2; 4 is a block diagram showing a series of considerations when designing the non-circular gear of Fig. 2 . Fig. 5 is a structural view showing a series of considerations when designing the non-circular gear of Fig. 2; Fig. 6 is a structural view showing a series of considerations when designing the non-circular gear of Fig. 2; Fig. 7 is a view showing a configuration example of a non-circular gear according to another embodiment of the present invention. -18- (16) 1257476 [Explanation of main component symbols] 10 Flowmeter 1 1 Outer frame 12 End panel 1 5 Magnetic detector 2 0 Metering chamber 21 inflow □ φ 2 2 Outlet 2 3 Rotating part 2 3 b End face 2 4 Rotary shaft 25 magnet 2 7 Rotating member 3 0 Non-circular gear 30' Non-circular gear · 3 1~3 7 Toothed 3 3 a Engaged tooth surface 3 3 b Non-intermeshing tooth surface 3 3c Teeth 3 6 a meshing tooth Face 3 8 recess 39 projection 3 9 'protrusion -19- (17) 1257476 48 recess 4 9 projection 4 9 'protrusion 5 0 non-circular gear 5 0' non-circular gear 5 1~5 7 tooth profile
58凹部 59凸部 66 齒形 67齒形 68 凹部 69凸部58 concave portion 59 convex portion 66 tooth shape 67 tooth shape 68 concave portion 69 convex portion
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