201231843 六、發明說明： 【日月戶斤々頁】 技術領域 本發明涉及設有内齒輪的變速器箱體。 C ^ 背景技術 以往公知有減速器等變速單元使用了行星齒輪機構 變速器。行星齒輪機構一般由太陽齒輪、多個行星齒輅的 行星架以及内齒輪等構成。 ^ 例如，如果是減速器，各行星齒輪以能夠自如旋轉 方式支承於與輸出軸連接的行星架，並以與太陽齒輪: 的方式配置在太陽齒輪周圍。内齒輪以不能旋轉的方0 置在這些行星齒輪_@並且與這些行星齒料合。通配 對太陽齒麟賴_動，各行星絲繞太陽齒輪公^過 伴隨著行星齒輪的公轉，行星架減速旋轉，其旋轉^ ° 過輸出轴而被輸出。 通 通常’内齒輪被嵌入到變速器箱體的内側，例如 將銷嵌人到械於内it輪和變速H箱體雙方的銷孔過 内齒輪被固定於變速器箱體^ ’ 關於本發明，公開了齒輪的製造方法(專利文獻^和嵌 入用齒輪(專利文獻2)。 在專利文獻1中’公開了主體部為樹脂成型件或者壓鑄 件的齒輪的製造方法。具體來說，對帶狀的鋼板實施滾乾 成型來形成平齒狀的齒部’將該齒部彎成圓形來形成齒部 201231843 環。使用模具向所述齒部環的内側注入熔融的合成樹脂戈 合金並使其固化，由此使齒輪成型為一體。 在專利文獻2中，公開了這樣的齒輪：在對齒輪進行壓 鑄成型時，能夠防止熔融的合成樹脂等流入到齒槽中。 體來說，該齒輪構成大致圓筒形狀’在齒輪的外周面形成 有齒槽。並且，在該齒輪的一個側面的周緣—體形成有阻 止成型材料的流入的凸緣部。 專利文獻1:曰本特開平7_125〇88號公報 專利文獻2:日本實開昭51_158961號公報 在行星齒輪機構中，由於對内齒輪施加大的轉矩， |aj 此，在内齒輪通過銷固定的現有的變速器箱體的情況下， 如果接合不夠充分，則可能導致錯位或晃動等。因此，、 者要求高度㈣型精度和裝配精度，在提高生產率和抑制 生產成本方面成為障礙。 I[瘦^明内容】 發明概要 因此’本發明的目的在於提供一種變速器箱體， 將内齒輪敎且牢ϋ地接合於變速$箱體，㈣提高 率和降低生產成本。 產 —為了達成上述目的，在本發财，在制齒輪的形狀進 行了研九的基礎上，將該内齒輪嵌入成型在了箱體部件令。 具體來說，本發明的變速器箱體是這樣的變速器箱 體’其包括··箱體部件，其包圍太陽齒輪和行星齒輪的周 圍；以及圓筒狀的内齒輪’其以旋轉軸線與所述太陽齒輪 4 201231843 一致的狀態固定在所述箱體部件的内側。 在所述内齒輪的一端設置有比齒的末端向内側探出的 環狀的流入限制部。在所述内齒輪的外周面設置有防滑 部，在3亥防滑部形成有一個以上的凸部或者凹部。並且， 所述箱體部件通過壓鑄而成型，所述内齒輪嵌入成型於所 述箱體部件。 根據這樣的結構的變速器箱體，在内齒輪的一端設置 有比齒的末端向内側探出的環狀的流入限制部，該内齒輪 嵌入成型於壓鑄成型的箱體部件中，因此，在將内齒輪裝 配於模具的型芯的時候，流入限制部與型芯接觸，這樣則 能夠通過型芯和流入限制部來密閉位於型腔内的内齒輪的 齒的部分(環狀齒）。 因此’能夠防止熔融的鋁合金等成型材料進入環狀齒 的情況，不會損害環狀齒的品質，能夠省去熔融屑的除去 等多餘的作業。 於内齒輪嵌入成型於箱體部件，因此即使不像以往 的銷固定等那樣確保高度的成型精度和裝配精度，也能夠 更加穩疋且牢固地接合内齒輪。由於也不需要銷固定等作 業，因此在生產率和生產成本方面报有利。而且，在内齒 輪的外周面設置有形成了-個以上的凸部或者凹部的防滑 部，因此，内嵩輪與箱體部件的接合面積增加，能夠更加 牢固地進行接合。 :選的是，所述流人限制部由與所述内齒輪分體形成的 圓魏的部件構成，所述流入限制部後安裝於所述内齒輪。 201231843 二樣的话’能夠通過拉削加工來形成環狀齒的部分， 因此此夠谷易地量產内齒輪，在生產率和生產成本方面报 優秀。 另外，優選的是，所述防滑部由與旋轉軸線大致平行 的線狀的凹凸結構構成。 ，的岵，利帛防滑部，能夠有效地承受使用時施加 於内齒輪的較大的轉矩，因此能夠更加穩定地防止内齒輪 的錯位或晃動。 此外’優選的是，在所述箱體部件在固定有所述内齒 輪的部分的外側具有沿著旋轉轴線方向延伸並且截面突出 的角形部的情況下’設置铸孔和㈣就的容積的形變防 止部。 當在箱體部件具有這樣的角形部的情況下，由於部位的 不同’成型材料的量會有不平衡，因此，成型材料固化時的 冷卻速度會有偏差而使箱體部件產生形變。其結果是對内齒 輪施加不平衡的形變力，因此内齒輪的正圓度會降低。 與此相對，通過設置鑄孔，能夠消除一定程度的不平 衡’在拔模關係上’鑄孔的長度和形狀由於模具的滑動方 向等而大受限制。因此’如果僅靠鑄孔，根據成型的箱體 部件的形狀的不同’成型材料的分佈會產生不平衡。因此， 通過在鏵孔之外另行設置形變防止部，能夠補充僅靠轉孔 無法補充的部分。其結果是，能夠使内齒輪周圍的紹合金 的刀佈均一化’能夠抑制對内齒輪施加不平衡的形變力， 月匕夠提南内齒輪的正圓度〇 201231843 例如，在所述鑄孔沿著旋轉軸線方向延伸的情況下， 優選在比所述鑄孔的末端靠裏側的位置設置所述形變防止 部。這樣的話，即使是在鑄孔的末端側存在厚壁部的情況 下，也能夠通過形變防止部來調整厚壁部的成型材料的 量，因此能夠抑制成型材料的分佈的不平衡。 所述形變防止部能夠與所述内齒輪設置成一體。 這樣的話，通過形變防止部也能夠獲得與防滑部同樣 的效果，因此能夠將内齒輪更加穩定且牢固地接合於箱體 部件。另外，能夠通過形變防止部在結構上強化内齒輪， 能夠進一步提高内齒輪的正圓度。 發明效果 與利用銷固定等固定了内齒輪的以往的變速器箱體相 比，能夠將内齒輪穩定且牢固地固定於變速器箱體。不需 要高度的成型精度和裝配精度，因此能夠提高生產率和降 低生產成本。 圖式簡單說明 圖1是表示本實施方式的變速器的概要立體圖。為了示 出内部，對變速器的一部分進行了剖切。 圖2是沿圖1中的X-X線的箱體部件的概要剖視圖。環 狀齒的部分僅圖示了一部分。 圖3是從圖2中的箭頭Y方向看到的箱體部件的概要圖。 圖4是表示内齒輪部件的概要立體圖。環狀齒以及防滑 部的部分僅圖示了一部分。 圖5是内齒輪部件的概要平面圖。 201231843 圖6是表示第一箱體部件的成型過程的概要圖。 圖7是表示第一箱體部件的成型過程的概要圖。 圖8是表示比較例中的内齒輪的正圓度的測定結果的 概要圖。 圖9是表示實施例中的内齒輪的正圓度的測定結果的 概要圖。 圖10是表示内齒輪部件的變形例的概要立體圖。環狀 齒和防滑部的部分僅圖示了一部分。 圖11中（a)和(b)是表示變速器箱體的變形例的概要正視 圖。 圖12是表示變速器箱體的變形例的概要剖視圖 圖13是表示變速器箱體的變形例的概要剖視圖。 I：實施方式3 具體實施方式 以下，根據附圖對本發明的實施方式進行詳細說明。 但是，以下的說明不過是本質上的例示而已，該說明並不 對本發明、其應用品以及其用途進行限定。 圖1表示應用了本發明的減速器（變速器）。減速器具有 箱體1(變速器箱體）、輸入部2、行星齒輪機構3以及輸出軸4 等。在該減速器中，電動機的驅動軸等與輸入部2連接，由 此，旋轉驅動力從輸入部2輸入到減速器中。利用行星齒輪 機構3，其旋轉速度被減速，通過輸出軸4輸出轉矩升高了 的旋轉驅動力。 行星齒輪機構3由太陽齒輪31、多個行星齒輪32、内齒 201231843 輪33以及行星杀34等構成。太陽齒輪3丨以能夠自如旋轉的 方式支承於鈿體1，太陽齒輪31借助於從輸入部2輸入的旋 轉驅動力而以旋轉軸線Α為中心旋轉。各行星齒輪3 2以與太 陽齒輪31响合的方式配置在太陽齒輪31周圍。各行星齒輪 3 2以能夠自如旋轉的方式支承於行星架3 4。行星架3 4經— 對軸承35a 35b而以能夠自如旋轉的方式支承於箱體1。在 本貫施方式中，輪出軸4與行星架34設成一體。 内齒輪33是齒形成在内側的齒輪。内齒輪33以與從形 成於行1架34的側面的窗部34禮出的各行星齒輪32嗜合 的方式，以使旋轉轴線八與太陽齿輪31 一致的狀態配置在a 們的周圍°内齒輪33以不能旋轉的方式配置在箱體！的内 側。因此’隨著太陽齒輪31的旋轉，各行星齒輪^自轉 且繞太陽純31公轉，伴隨於此，行星糾(輸出偏自 定的減速比以旋轉轴線人為中心旋轉。另外，對於内齒 的詳細情況將在後文另行敍述。 本實施方式的箱體1由彼此對接而成為一體的第一… 體部件1〇(紐部件)和第二龍部件2G構成。輸人部: 在第二箱體部件20側，包括㈣輪33在内，行星齒輪機構的 和輸出軸4收納在第—箱體部件1〇側。所述第一箱體部 等使用鋁合金等成型材料通過壓鑄而成型。 〇 圖2和圖3表示第一箱體部件10的詳細情況。第一〜 部件10具有：外側的截面賴為四邊料周壁部U 1目體 堵塞周壁部U的-端的端壁部12。包括太陽齒輪31和2 齒輪32的行星齒輪機構3的周圍被周壁部丨丨包圍。 201231843 在端壁部12的中央部分，形成有呈圓筒狀突出的軸承 保持部13。在該軸承保持部13的内側，嵌入固定有上述的 軸承35a。並且，輸出軸4的末端部分穿過開設於軸承保持 部13的中央的軸孔14而突出到箱體1的外部。 在周壁部11中的各角的部分（角形部1丨a)，沿著旋轉輛 線A方向貫穿有用於與第二箱體部件2〇進行緊固的螺拴孔 15(4處）。此外，在各角形部Ua形成有鑄孔16。 本實施方式的鑄孔16從開口側（端壁部12的相反側）> 旋轉軸線A方向延伸，其内周面由截面為弧狀的弧狀面 16a、以及從弧狀面16a向外側連續並避開螺栓孔u而形成 為截面呈W字狀的W字狀面16b構成。本實施方式的鱗μ 形成為截面朝向末端而逐漸減小的末端較細的形狀(拔模 斜又）另外，拔模斜度並不是鑄孔16所必需的，只 j 側不比基端側大即可。 鸲 的内側，從開口側朝向端壁部12形 徑孔部Π，鼓射L和與歸_卵連通 部13要大。大徑練聰度形成得比周 、又®2中用標號1表示）要小，在周壁部11的與端 W的連接部分，存在厚壁㈣，該厚壁部 壁部11中的其他部分 Μ比周 的部分），料“^ 魏部17的裏侧(底 i而—體地固定有内齒輪部件50。 :表㈣齒輪部件5Q的詳細情況。内 鐵制的部件，其且古 "干川疋鋼 成為一體的形變防筒狀的齒輪部51、與齒輪部51形 万止452、以及環狀板53(流入限制部）。齒 10 201231843 輪部51是構成内齒輪33的部位。在齒輪部51的内周面，通 過拉削加工而呈環狀地形成有與各行星齒輪32嚙合的一組 齒（環狀齒51a)。 環狀板53是相對於齒輪部51和形變防止部52另行設置 的、由金屬板㈣形成的圓環狀的部件，其後安裝於齒輪 部51等。環狀板53通過焊接等_定於齒輪部㈣靠形變 防止部52側的-端，並與環狀齒51a的—端緊密接觸。環狀 板53被設定成其内周緣比各個齒的末端向内側探出。 在齒輪部51的外周面，在整周範圍形成有防滑部 本實施方式的防滑部54由與旋轉軸線从致平行地延伸的 多個線狀的凹凸形狀構成。防滑部54_㈣成為銳利的 折線形狀。 通過在齒輪部51的外周面設置這樣的防滑料，在將 内齒輪部件50嵌人成型於第—箱體部_的時候，兩者的 接合面積增力口 ’因此能夠更加牢固地進行接合。而且，通 過使防滑部54由與旋轉轴線AA致平行地延伸的多個線狀 的凹凸形狀構成’能夠有效地承受施加於環狀#5u的大的 轉矩’因此’能夠防止齒輪部51的錯位或晃動。 ★形變防止部52具有：與絲部端連續地延伸的圓 筒狀的延伸部似’以及從延伸部似的末端在整周範圍向徑 向外侧探出的凸緣部52b 〇如圖5所示，凸緣部52b的與周壁 部U的邊的部分(邊部)對置的部位形成為與触部U大致平 打：凸緣部52b的與周壁部u的各角形部⑴對置的部位形成 為圓弧狀。角形部Ua側的部位比邊部側的部位探出得更多。 11 201231843 内齒輪部件50是以環狀板53側朝向端壁部12的狀態嵌 入成型於第一箱體部件10的’形變防止部52被埋設於厚壁 部18中。如圖2和圖5所示’特別是在角形部11a，凸緣部52b 進入到鑄孔16的末端的裏面（下側）並佔據了預定的容積。更 詳細來說，在内齒輪部件50的周圍的部分處的邊部和角形 部11a，通過凸緣部52b和鑄孔16進行了調整使得鋁合金的 部分所占的容積儘量相等。 在拔模的關係方面，鑄孔16無法使其末端側增大，因 此，雖然與模具有關’但是僅通過鎢孔16在厚壁部18確保 足夠的容積並不容易。特別是在成型時使用由僅向一個方 向相對滑動的一對模具構成的簡易模具的情況下，非常困 難。因此，通過相對於鑄孔16另行設置形變防止部52，能 夠通過形變防止部52來補充容積不足的部分。這樣，通過 使内齒輪部件50周圍的鋁合金的分佈均一化，能夠有效地 抑制齒輪部51的形變。 接下來，參照圖6和圖7對第—箱體部件1〇的一般的成 型過私進行說明。如圖6所示，例如使用由固定模具（陰模） 以及可動模具62(陽模)構成的—對模具，通過壓鑄成型來形 成第彳目H部件1〇。這時，内絲部件5G被插人到模具的 型腔（空洞）來進行—體成型（I入成型）。 立在固疋模具61設置有形成周壁部11的外表面側的第一 * P 1 a以及形成軸承保持部丨3的外表面側的第二孔部6化 專固疋模具61被固定，相對於©定模具6卜可動模具62 在模具的中心、線S的方向滑動移位。另外，模具的中心如 12 201231843 與旋轉軸線A—致。 在可動杈具62設置有：中心芯62a、形成螺栓孔15的内 表面侧的柱狀芯62b、以及形成鑄孔16的内表面側的鑄芯 62c等。中心芯62a的基部的外形形成為比齒輪部51的内徑 稍小，以便能夠裝配齒輪部51。在中心芯62a的基部的上 鈿°又置有外控與環狀板53的内徑大致相同的接觸部63， 以便與環狀板53接觸。料，在巾《必的末端側，還設 置有形成軸孔14和軸承保持部13的内表面側的部分等。 内齒輪部件50以環狀板53側朝向固定模具61的底側的 狀態裝配於可動模具62的中d'62a的基部。這樣，齒輪部 51的％狀齒51a的部分被環狀板53和可動模具62堵住。並 且，如箭頭所示，可動模具62進入到固定模具61中，如圖7 所示，兩者接合H由此，在模具内部職了預定形 狀的型腔。 一然後，從設於固定模具61的注入口（未圖示）壓入溶融的 高溫的铭合金，將其喷射到型腔内。此時，環狀齒仏的部 分被環狀板53等堵塞，因此，能夠防趣合金進入到環狀 齒51a的部分。 在向型腔内注入了足夠的！呂合金之後，為了使銘合金 固化’通過自然放冷來進行冷卻處理。此主 口、 吟，通過鑄芯62c 和形變防止部52調整成··對於内齒輪部件5〇的周圍立 處的型腔的容積，變得大致均一，因此，邊如 ° 的^分 u您邵、角形部 厚壁部18等總容積不同的部位處的内齒輪部件％周 a、 合金的冷卻速度大致相同。其結果是，鋁八么 °園的在呂 .σ金的形變變小， 13 201231843 施加於内齒輪部件5G的形變力的不平衡減輕，因此能夠提 向齒輪部51 (環狀齒51 a)的正圓度。 (實施例） 為了確認形變防止部帶來的效果，製作使用了沒有形 變防止部的内齒輪部件的箱體部件（比較例）和使用了具有 形變防止部的内齒輪部件的箱體部件(實施例），對兩者的環 狀齒的正圓度進行比較。 關於比較所使用的箱體部件和内齒輪部件，除了形變 防止部的有無之外，形狀以及成型方法與上述實施方式的 第-箱體部件1G和内齒輪部件5G是相關。正圓度的測定 是在相同條件下、對於實施例品和比㈣品在旋轉軸線方 向的上部（開口側）、中央部以及下部（端壁部側）這預定的三 個部位在整周範圍對環狀齒的節圓直徑(pCD)進行了測定。 圖8表示比較例的PCD的測定結果。在該圖中，標號s 所示的曲線表示了嵌入成型前（未處理）的pCD的分佈。另 外，標號10所示的假像線表示了與PCD測定部位對應的箱 體部件外廓線。如該圖所示，成型後與處理前相比PCD有 所減小，其分佈越朝向底側偏差越大。特別是確認到了邊 部側的PCD比角部側的PCD小的趨勢。 圖9表示實施例的PCD的測定結果。該圖中，標號S所 不的曲線是未處理的PCD分佈，是與比較例大致相同的 值。在實施例的情況下’與比較例相比，成型前後的PCD 的差減小。另外，成型後的各部位的PCD的偏差也減小， 可以確認到與比較例相比正圓度大幅度提高。 201231843 (其他） 本發明的變速器箱體並不限定於上述實施方式，也包 括除此之外的各種結構。 例如，在箱體部件是圓形截面的情況下等，當在齒輪 部51(内齒輪33)的周圍鋁合金所占的容積沒有很大的差的 情況下，如圖10所示，可以不在内齒輪部件50設置形變防 止部52。 箱體部件的截面形狀並不限定於四邊形。例如，如圖 11的（a)所示，第一箱體部件10(周壁部11)的截面形狀也可 以是五邊形等，如圖11的（b)所示，也可以是一部分的截面 為圓形，而在一部分設置有角形部。另外，雖然未圖示， 但是旋轉軸線A也可以相對於箱體部件偏心配置。 另外，在上述的實施方式中，示出了第一箱體部件10 由周壁部11和堵塞其一端的端壁部12成型為一體的情況， 但是也可以分別形成與周壁部11相當的部件以及與端壁部 12相當的部件，通過將它們組合起來來構成第一箱體部件 1〇(參照圖12)。另外，該情況下的箱體部件為筒狀。 在上述的實施方式中，示出了可動模具由一個零件構 成的情況，但是可動模具也可以由多個零件構成。在該情 況下，由於與各零件的滑動方向對應地設置鑄芯，因此， 鑄孔16的延伸方向不限定於中心線S的方向。例如，鑄孔16 可以沿著與中心線S正交的方向或相對於中心線S傾斜的方 向延伸。 這樣，鑄孔16還可以如圖12或圖13所示形成為從周壁 15 201231843 部11的側方凹陷。 防滑面還可以用多個點狀突起或一個以上的線狀突起 構成。鑄孔和形變防止部的形狀可以根據箱體部件的形狀 等適當地形成。形變防止部也與環狀板一樣，可以後安裝 於内齒輪。 t：圖式簡單說明3 圖1是表示本實施方式的變速器的概要立體圖。為了示 出内部，對變速器的一部分進行了剖切。 圖2是沿圖1中的X-X線的箱體部件的概要剖視圖。環 狀齒的部分僅圖示了一部分。 圖3是從圖2中的箭頭Y方向看到的箱體部件的概要圖。 圖4是表示内齒輪部件的概要立體圖。環狀齒以及防滑 部的部分僅圖示了一部分。 圖5是内齒輪部件的概要平面圖。 圖6是表示第一箱體部件的成型過程的概要圖。 圖7是表示第一箱體部件的成型過程的概要圖。 圖8是表示比較例中的内齒輪的正圓度的測定結果的 概要圖。 圖9是表示實施例中的内齒輪的正圓度的測定結果的 概要圖。 圖10是表示内齒輪部件的變形例的概要立體圖。環狀 齒和防滑部的部分僅圖示了一部分。 圖11中（a)和(b)是表示變速器箱體的變形例的概要正視 圖。 16 201231843 圖12是表示變速器箱體 圖13是表示變速器箱體 【主要元件符號說明 1···箱體(變速器箱體） 2.. .輸入部 3.. .行星齒輪機構 4.. .輸出軸 10··.第一箱體部件(箱體部件） 11.. .周壁部 11a···角形部 12.. .端壁部 13.. .軸承保持部 14.. .軸孔 15.. .螺栓孔 16…鑄孔 16a...弧狀面 16b... W字狀面 17.. .大徑孔部 18…厚壁部 20.. .第二箱體部件 31…太陽齒輪 32…行星齒輪 33…内齒輪 34…行星架 的變形例的概要剖視圖 的變形例的概要剖視圖。 1 34a...窗部 35a、35b.··軸承 50···内齒輪部件 51…齒輪部 51a…環狀齒 52…形變防止部 52a...延伸部 52b...凸緣部 53·.·環狀板(流入限制部) 54…防滑部 61.. .固定模具 61a...第一孔部 61b...第二孔部 62.. .可動模具 62a...中心芯 62b...柱狀芯 62c...鑄: 63.. .接觸部 5.. .中心線 A...旋轉軸線 17201231843 VI. Description of the Invention: [Sun Moon Household Page] Technical Field The present invention relates to a transmission case provided with an internal gear. C ^ Background Art Conventionally, a transmission unit such as a speed reducer has been known to use a planetary gear mechanism transmission. The planetary gear mechanism is generally composed of a sun gear, a carrier of a plurality of planetary gears, an internal gear, and the like. ^ For example, in the case of a speed reducer, each of the planetary gears is rotatably supported by a carrier coupled to the output shaft and disposed around the sun gear in a manner similar to the sun gear: The internal gears are placed in these planetary gears _@ with a non-rotating side 0 and are combined with these planetary teeth. The sun gear is swayed by the sun, and the planets are wound around the sun gear. With the revolution of the planet gears, the planet carrier decelerates and rotates, and its rotation is output through the output shaft. Generally, the internal gear is embedded in the inner side of the transmission case, for example, the pin hole is embedded in the pin hole and the internal gear of the shifting H case is fixed to the transmission case. A method of manufacturing a gear (a patent document and a gear for embedding (Patent Document 2). In Patent Document 1, a method of manufacturing a gear in which a main body portion is a resin molded product or a die-casting member is disclosed. Specifically, a belt-shaped method is used. The steel sheet is subjected to roll-drying to form a flat-toothed tooth portion. The tooth portion is bent into a circular shape to form a ring portion 201231843. The molten synthetic resin Go alloy is injected into the inside of the tooth ring and cured by using a mold. In this case, the gear is integrally molded. In the case of the die-casting of the gear, it is possible to prevent the molten synthetic resin or the like from flowing into the tooth gap. The cylindrical shape ' is formed with a tooth groove on the outer circumferential surface of the gear. Further, a flange portion that blocks the inflow of the molding material is formed on the periphery of one side surface of the gear. Patent Document 1: 曰本特In the planetary gear mechanism, since a large torque is applied to the internal gear, |aj, the existing transmission case in which the internal gear is fixed by the pin is disclosed in Japanese Laid-Open Patent Publication No. Hei 51-158961. In this case, if the joint is insufficient, it may cause misalignment or sway, etc. Therefore, the height (four) type accuracy and assembly accuracy are required, which is an obstacle in improving productivity and suppressing production costs. The object of the present invention is to provide a transmission case in which the internal gear is firmly and firmly engaged with the shifting box, (4) the rate of increase and the production cost are reduced. Production - In order to achieve the above purpose, the gear is made in the present The shape of the casing is embedded in the casing member. Specifically, the transmission case of the present invention is a transmission case that includes a casing member that surrounds a sun gear and a planetary gear; and a cylindrical inner gear 'fixed in a state in which the axis of rotation coincides with the sun gear 4 201231843 An inner side of the inner gear is provided with an annular inflow restricting portion that is protruded inward from the end of the tooth. An outer surface of the inner gear is provided with an anti-slip portion, and the anti-slip portion is provided at 3 More than one convex portion or concave portion is formed. Further, the case member is molded by die casting, and the internal gear is insert-molded to the case member. According to the transmission case of such a configuration, one end of the internal gear is provided There is an annular inflow restricting portion that protrudes inward from the end of the tooth, and the internal gear is insert-molded into the die-cast case member. Therefore, when the internal gear is fitted to the core of the mold, the inflow restricting portion is When the core is in contact, the core portion and the inflow restricting portion can seal the portion (annular tooth) of the tooth of the internal gear located in the cavity. Therefore, it is possible to prevent the molding material such as molten aluminum alloy from entering the annular tooth. The quality of the ring-shaped teeth is not impaired, and unnecessary work such as removal of the molten chips can be omitted. Since the internal gear is insert-molded into the case member, the internal gear can be more stably and firmly joined without securing the high molding accuracy and assembly accuracy as in the conventional pin fixing. Since it is not necessary to perform work such as pin fixing, it is advantageous in terms of productivity and production cost. Further, since the outer peripheral surface of the inner ring is provided with an anti-slip portion in which a plurality of convex portions or concave portions are formed, the joint area between the inner turn wheel and the case member is increased, and the joining can be performed more firmly. It is preferable that the flow restricting portion is constituted by a member formed of a separate body formed by the internal gear, and the inflow restricting portion is attached to the internal gear. In the case of 201231843, it is possible to form a portion of the ring-shaped tooth by broaching. Therefore, it is easy to mass-produce the internal gear, and it is excellent in terms of productivity and production cost. Further, it is preferable that the anti-slip portion is constituted by a linear uneven structure substantially parallel to the rotation axis. In addition, the anti-slip portion can effectively withstand a large torque applied to the internal gear during use, so that the misalignment or sway of the internal gear can be more stably prevented. Further, it is preferable to set the casting hole and the volume of the (four) in the case where the casing member has an angular portion extending in the direction of the rotation axis and protruding in the outer side of the portion to which the internal gear is fixed. Deformation prevention section. In the case where the box member has such an angular portion, the amount of the molding material may be unbalanced due to the difference in the portion. Therefore, the cooling rate at the time of curing of the molding material may vary to deform the casing member. As a result, an unbalanced deformation force is applied to the internal gear, so that the roundness of the internal gear is lowered. On the other hand, by providing the casting hole, it is possible to eliminate a certain degree of imbalance 'in the draft relationship'. The length and shape of the casting hole are greatly limited by the sliding direction of the mold or the like. Therefore, if the hole is cast only, the distribution of the molding material may be unbalanced depending on the shape of the formed box member. Therefore, by separately providing the deformation preventing portion outside the pupil, it is possible to supplement the portion which cannot be replenished only by the through hole. As a result, it is possible to uniformize the knives of the sinter alloy around the internal gears', and it is possible to suppress the unbalanced deformation force applied to the internal gears, and the fullness of the inner gears can be increased. 201231843 For example, in the casting holes In the case of extending in the direction of the rotation axis, it is preferable to provide the deformation preventing portion at a position on the back side of the end of the casting hole. In this case, even when the thick portion is present on the end side of the casting hole, the amount of the molding material in the thick portion can be adjusted by the deformation preventing portion, so that the imbalance of the distribution of the molding material can be suppressed. The deformation preventing portion can be provided integrally with the internal gear. In this case, the same effect as the anti-slip portion can be obtained by the deformation preventing portion, so that the internal gear can be more stably and firmly joined to the case member. Further, the internal gear can be structurally strengthened by the deformation preventing portion, and the roundness of the internal gear can be further improved. Advantageous Effects of Invention The internal gear can be stably and firmly fixed to the transmission case as compared with the conventional transmission case in which the internal gear is fixed by pin fixing or the like. It does not require high molding accuracy and assembly accuracy, thus increasing productivity and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic perspective view showing a transmission according to an embodiment of the present invention. In order to show the inside, a part of the transmission is cut. Fig. 2 is a schematic cross-sectional view of the casing member taken along line X-X of Fig. 1. The portion of the ring tooth is only a part of it. Fig. 3 is a schematic view of the casing member as seen from the direction of the arrow Y in Fig. 2; 4 is a schematic perspective view showing an internal gear member. The annular teeth and the portions of the anti-slip portions are only partially shown. Fig. 5 is a schematic plan view of an internal gear member. 201231843 Fig. 6 is a schematic view showing a molding process of the first case member. Fig. 7 is a schematic view showing a molding process of the first case member. Fig. 8 is a schematic view showing measurement results of the roundness of the internal gear in the comparative example. Fig. 9 is a schematic view showing the measurement results of the roundness of the internal gear in the embodiment. FIG. 10 is a schematic perspective view showing a modification of the internal gear member. The portions of the annular teeth and the anti-slip portions are only partially illustrated. Fig. 11 (a) and (b) are schematic front views showing a modification of the transmission case. Fig. 12 is a schematic cross-sectional view showing a modification of the transmission case. Fig. 13 is a schematic cross-sectional view showing a modification of the transmission case. I. Embodiment 3 BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the following description is merely an essential example, and the description does not limit the invention, its application, and its use. Fig. 1 shows a speed reducer (transmission) to which the present invention is applied. The speed reducer has a casing 1 (transmission case), an input unit 2, a planetary gear mechanism 3, an output shaft 4, and the like. In the speed reducer, the drive shaft of the motor or the like is connected to the input unit 2, whereby the rotational driving force is input from the input unit 2 to the speed reducer. With the planetary gear mechanism 3, the rotational speed is decelerated, and the rotational driving force whose torque is increased is output through the output shaft 4. The planetary gear mechanism 3 is composed of a sun gear 31, a plurality of planetary gears 32, an internal tooth 201231843 wheel 33, and a planetary killer 34. The sun gear 3 is rotatably supported by the body 1 and the sun gear 31 is rotated about the rotation axis 借助于 by the rotational driving force input from the input unit 2. Each of the planetary gears 3 2 is disposed around the sun gear 31 so as to be coupled to the sun gear 31. Each of the planetary gears 3 2 is rotatably supported by the carrier 34. The carrier 3 4 is supported by the casing 1 so as to be rotatable about the bearings 35a to 35b. In the present embodiment, the wheel shaft 4 is integrally formed with the carrier 34. The internal gear 33 is a gear in which teeth are formed inside. The internal gear 33 is disposed around the respective planetary gears 32 greeted by the window portion 34 formed on the side surface of the row frame 34 so that the rotation axis eight coincides with the sun gear 31. The internal gear 33 is disposed in the housing in a non-rotatable manner! The inside side. Therefore, with the rotation of the sun gear 31, each of the planetary gears ^ rotates and revolves around the sun for 31 revolutions, and along with this, the planetary correction (the output-defining speed reduction ratio is rotated centering on the rotation axis. In addition, for the internal teeth The details will be described later. The casing 1 of the present embodiment is composed of a first body member 1 〇 (new member) and a second dragon member 2G which are integrated with each other. The input unit: in the second box On the body member 20 side, the planetary gear mechanism and the output shaft 4 are housed on the side of the first case member 1 including the (four) wheel 33. The first case portion or the like is molded by die casting using a molding material such as aluminum alloy. 2 and 3 show the details of the first case member 10. The first to member 10 has an outer wall portion 12 which is formed by the four-side material peripheral wall portion U1 blocking the end portion of the peripheral wall portion U. The periphery of the planetary gear mechanism 3 of the sun gear 31 and the second gear 32 is surrounded by the peripheral wall portion. 201231843 A bearing holding portion 13 that protrudes in a cylindrical shape is formed in a central portion of the end wall portion 12. In the bearing holding portion 13 Inside, embedded and fixed above The end portion of the output shaft 4 protrudes to the outside of the casing 1 through the shaft hole 14 opened in the center of the bearing holding portion 13. The portion of each corner in the peripheral wall portion 11 (the angular portion 1a) The threaded holes 15 (four places) for fastening to the second case member 2A are inserted in the direction of the rotation line A. Further, the casting holes 16 are formed in the respective angular portions Ua. The cast hole 16 extends from the opening side (opposite side of the end wall portion 12) > in the direction of the rotation axis A, and the inner peripheral surface thereof is formed by an arcuate surface 16a having an arcuate cross section and continuous outward from the arcuate surface 16a. The bolt hole u is formed in a W-shaped surface 16b having a W-shaped cross section. The scale μ of the present embodiment is formed into a shape in which the end portion is gradually reduced toward the end and is thinner (the draft is inclined). The inclination is not necessary for the casting hole 16, and only the j side is not larger than the base end side. The inner side of the crucible, from the opening side toward the end wall portion 12, the diameter hole portion Π, the bulging L and the _ egg connection portion 13 is bigger. The large-scale training is formed smaller than the week, and the number 2 in the ®2 is smaller, and is connected to the end W of the peripheral wall portion 11. In part, there is a thick wall (four), and the other portion of the thick wall portion 11 is a portion of the circumference of the wall portion 11), and the inner side of the inner portion of the material portion 17 is fixed. The inner gear member 50 is fixed to the bottom portion. (4) Details of the gear member 5Q. The inner iron member is an integral deformation-proof cylindrical gear portion 51, the gear portion 51 shape 452, and the annular plate 53 (inflow) Restriction portion). The tooth portion 10 is a portion that constitutes the internal gear 33. The inner peripheral surface of the gear portion 51 is formed in a ring shape by a broaching process to form a group of teeth that mesh with the planetary gears 32. The annular plate 53 is an annular member formed of a metal plate (four) separately provided for the gear portion 51 and the deformation preventing portion 52, and is attached to the gear portion 51 or the like. The annular plate 53 is fixed to the end of the gear portion (4) on the side of the deformation preventing portion 52 by welding or the like, and is in close contact with the end of the annular tooth 51a. The annular plate 53 is set such that its inner periphery protrudes inward from the end of each tooth. An anti-slip portion is formed over the entire circumference of the outer peripheral surface of the gear portion 51. The anti-slip portion 54 of the present embodiment is constituted by a plurality of linear concavo-convex shapes extending in parallel with the rotation axis. The anti-slip portion 54_(4) has a sharp fold line shape. When such an anti-slip material is provided on the outer peripheral surface of the gear portion 51, when the internal gear member 50 is fitted into the first case portion, the joint area of the both sides can be more firmly joined. In addition, the anti-slip portion 54 is configured by a plurality of linear concavo-convex shapes extending in parallel with the rotation axis AA to be able to effectively withstand a large torque applied to the ring #5u. Therefore, the gear portion 51 can be prevented. Misplacement or shaking. The deformation preventing portion 52 has a cylindrical extending portion that continuously extends from the end of the wire portion, and a flange portion 52b that protrudes outward in the radial direction over the entire circumference from the end of the extending portion. The portion of the flange portion 52b that faces the side portion (side portion) of the peripheral wall portion U is formed to be substantially flush with the contact portion U: a portion of the flange portion 52b that faces each of the angular portions (1) of the peripheral wall portion u Formed in an arc shape. The portion on the side of the angular portion Ua is found to be more than the portion on the side of the side portion. 11 201231843 The internal gear member 50 is embedded in the thick portion 18 by the deformation preventing portion 52 that is fitted into the first casing member 10 in a state in which the annular plate 53 side faces the end wall portion 12. As shown in Figs. 2 and 5, particularly in the angular portion 11a, the flange portion 52b enters the inside (lower side) of the end of the casting hole 16 and occupies a predetermined volume. More specifically, the side portion and the angular portion 11a at the portion around the inner gear member 50 are adjusted by the flange portion 52b and the casting hole 16 so that the portions occupied by the aluminum alloy portions are as equal as possible. In terms of the draft relationship, the casting hole 16 cannot increase its end side, and therefore, it is not easy to ensure a sufficient volume in the thick portion 18 only by the tungsten hole 16 although it is related to the mold. In particular, in the case of using a simple mold composed of a pair of molds that slide only in one direction in the molding, it is extremely difficult. Therefore, by separately providing the deformation preventing portion 52 with respect to the casting hole 16, the portion having insufficient volume can be replenished by the deformation preventing portion 52. Thus, by uniformizing the distribution of the aluminum alloy around the internal gear member 50, the deformation of the gear portion 51 can be effectively suppressed. Next, the general molding of the first case member 1A will be described with reference to Figs. 6 and 7 . As shown in Fig. 6, for example, a first pair of H-pieces 1 is formed by die-casting using a pair of molds composed of a fixed mold (female mold) and a movable mold 62 (male mold). At this time, the inner wire member 5G is inserted into the cavity (cavity) of the mold to perform body molding (into molding). The solid mold 61 is provided with a first * P 1 a forming the outer surface side of the peripheral wall portion 11 and a second hole portion 6 forming the outer surface side of the bearing holding portion 3 to be fixed, and the mold 61 is fixed. The movable mold 62 is slidably displaced in the center of the mold and in the direction of the line S. In addition, the center of the mold, such as 12 201231843, is aligned with the axis of rotation A. The movable cooker 62 is provided with a center core 62a, a columnar core 62b on the inner surface side where the bolt holes 15 are formed, and a casting core 62c on the inner surface side where the cast hole 16 is formed. The outer shape of the base of the center core 62a is formed to be slightly smaller than the inner diameter of the gear portion 51 so that the gear portion 51 can be assembled. Further, a contact portion 63 whose outer diameter is substantially the same as that of the annular plate 53 is placed on the upper portion of the base of the center core 62a so as to be in contact with the annular plate 53. In the "end end side of the towel", a portion where the shaft hole 14 and the inner surface side of the bearing holding portion 13 are formed is also provided. The internal gear member 50 is attached to the base portion d'62a of the movable mold 62 with the annular plate 53 side facing the bottom side of the fixed mold 61. Thus, the portion of the %-shaped tooth 51a of the gear portion 51 is blocked by the annular plate 53 and the movable mold 62. Further, as indicated by the arrow, the movable mold 62 enters the fixed mold 61, as shown in Fig. 7, and the two are joined to each other, whereby a cavity having a predetermined shape is placed inside the mold. Then, a molten high-temperature alloy is pressed from an injection port (not shown) provided in the fixed mold 61, and is ejected into the cavity. At this time, since the portion of the annular gingival is blocked by the annular plate 53 or the like, the anti-fun alloy can enter the portion of the annular tooth 51a. Inject enough into the cavity! After the Lu alloy, in order to cure the alloy, it is cooled by natural cooling. The main port and the cymbal are adjusted by the casting core 62c and the deformation preventing portion 52 so that the volume of the cavity around the inner gear member 5A is substantially uniform, and therefore, the side is like a ° The inner gear member % circumference a at the portion where the total volume is different, such as the Shao and the angled portion thick portion 18, and the cooling rate of the alloy are substantially the same. As a result, the deformation of Lu. σ gold in the aluminum slab is small, and the imbalance of the deformation force applied to the internal gear member 5G is reduced in 13 201231843, so that the gear portion 51 (annular tooth 51 a) can be lifted. Roundness. (Example) In order to confirm the effect by the deformation preventing portion, a case member (comparative example) using an internal gear member having no deformation preventing portion and a case member using an internal gear member having a deformation preventing portion were produced (implementation) Example), comparing the roundness of the annular teeth of the two. Regarding the comparison between the case member and the internal gear member used, the shape and the molding method are related to the first case member 1G and the internal gear member 5G of the above-described embodiment, in addition to the presence or absence of the deformation preventing portion. The roundness is measured over the entire circumference of the predetermined three conditions in the upper part (open side), the center part, and the lower part (end wall side) of the embodiment product and the ratio (4) in the direction of the rotation axis under the same conditions. The pitch circle diameter (pCD) of the annular teeth was measured. Fig. 8 shows the measurement results of the PCD of the comparative example. In the figure, the curve indicated by the symbol s indicates the distribution of pCD before (formed) embedded molding. Further, the imaginary line indicated by reference numeral 10 indicates the outline of the box member corresponding to the PCD measurement portion. As shown in the figure, the PCD is reduced after molding and before the treatment, and the deviation of the distribution toward the bottom side is larger. In particular, it was confirmed that the PCD on the side of the side was smaller than the PCD on the side of the corner. Fig. 9 shows the measurement results of the PCD of the example. In the figure, the curve indicated by the reference numeral S is an unprocessed PCD distribution, and is substantially the same value as the comparative example. In the case of the embodiment, the difference in PCD before and after molding was reduced as compared with the comparative example. Further, the variation in PCD at each portion after molding was also reduced, and it was confirmed that the roundness was greatly improved as compared with the comparative example. 201231843 (Others) The transmission case of the present invention is not limited to the above embodiment, and various other configurations are also included. For example, in the case where the case member has a circular cross section or the like, when the volume occupied by the aluminum alloy around the gear portion 51 (internal gear 33) is not greatly different, as shown in FIG. 10, it may not be The internal gear member 50 is provided with a deformation preventing portion 52. The cross-sectional shape of the case member is not limited to the quadrilateral shape. For example, as shown in FIG. 11( a ), the cross-sectional shape of the first case member 10 (peripheral wall portion 11 ) may be a pentagon or the like, as shown in FIG. 11( b ), or may be a part of the cross section. It is round and has a corner portion in a part. Further, although not shown, the rotation axis A may be arranged eccentrically with respect to the case member. Further, in the above-described embodiment, the first case member 10 is integrally molded by the peripheral wall portion 11 and the end wall portion 12 that closes one end thereof. However, the members corresponding to the peripheral wall portion 11 may be formed separately. The members corresponding to the end wall portion 12 are combined to form a first case member 1 (see Fig. 12). Further, the case member in this case has a tubular shape. In the above embodiment, the case where the movable mold is constituted by one part is shown, but the movable mold may be composed of a plurality of parts. In this case, since the casting core is provided corresponding to the sliding direction of each component, the extending direction of the casting hole 16 is not limited to the direction of the center line S. For example, the cast hole 16 may extend in a direction orthogonal to the center line S or in a direction inclined with respect to the center line S. Thus, the casting hole 16 can also be formed to be recessed from the side of the peripheral wall 15 201231843 portion 11 as shown in Fig. 12 or Fig. 13 . The non-slip surface may also be formed by a plurality of dot protrusions or one or more linear protrusions. The shape of the cast hole and the deformation preventing portion can be appropriately formed in accordance with the shape of the case member or the like. The deformation preventing portion is also attached to the internal gear like the annular plate. t: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view showing a transmission according to the present embodiment. In order to show the inside, a part of the transmission is cut. Fig. 2 is a schematic cross-sectional view of the casing member taken along line X-X of Fig. 1. The portion of the ring tooth is only a part of it. Fig. 3 is a schematic view of the casing member as seen from the direction of the arrow Y in Fig. 2; 4 is a schematic perspective view showing an internal gear member. The annular teeth and the portions of the anti-slip portions are only partially shown. Fig. 5 is a schematic plan view of an internal gear member. Fig. 6 is a schematic view showing a molding process of the first case member. Fig. 7 is a schematic view showing a molding process of the first case member. Fig. 8 is a schematic view showing measurement results of the roundness of the internal gear in the comparative example. Fig. 9 is a schematic view showing the measurement results of the roundness of the internal gear in the embodiment. FIG. 10 is a schematic perspective view showing a modification of the internal gear member. The portions of the annular teeth and the anti-slip portions are only partially illustrated. Fig. 11 (a) and (b) are schematic front views showing a modification of the transmission case. 16 201231843 Fig. 12 is a view showing a transmission case. Fig. 13 is a view showing a transmission case. [Main component code description 1···box (transmission case) 2. Input unit 3. Planetary gear mechanism 4.. Output Shaft 10··. First box member (box member) 11.. Peripheral wall portion 11a···Angle portion 12: End wall portion 13.. Bearing retaining portion 14.. Shaft hole 15.. Bolt hole 16... Cast hole 16a... Arc surface 16b... W-shaped surface 17: Large diameter hole portion 18: Thick portion 20: Second case member 31... Sun gear 32... Planetary gear 33... Internal gear 34: A schematic cross-sectional view of a modification of a schematic cross-sectional view of a modification of the carrier. 1 34 a ... window portion 35 a , 35 b . . . bearing 50 · internal gear member 51 ... gear portion 51 a ... annular tooth 52 ... deformation preventing portion 52 a ... extending portion 52 b ... flange portion 53 · . . annular plate (inflow restricting portion) 54... non-slip portion 61.. fixed mold 61a... first hole portion 61b... second hole portion 62.. movable mold 62a... center core 62b. .. cylindrical core 62c... cast: 63.. contact portion 5.. center line A... rotation axis 17