200946800 九、發明說明 【發明所屬之技術領域】 本發明是關於螺帽構件透過滾珠螺合於螺桿，例如可 於工作機械的工作台等將馬達的旋轉運動轉換成直線運動 的滾珠螺桿裝置，詳細地說是關於型式爲大致U字形回 轉管裝接在螺帽構件形成滾珠無限循環道的滾珠螺桿裝置 的改良。 ❹ 【先前技術】 所謂使用回轉管形成滾珠無限循環道的滾珠螺桿裝置 ’例如已知有日本特開2002-982 12等各種的滾珠螺桿裝 置。該滾珠螺桿裝置，具備：多數滾珠；形成有該等滾珠 滾行用螺旋狀滾動溝槽的螺桿；具有和上述滾動溝槽成相 向的螺旋狀負荷滾動溝槽的同時透過滾珠螺合於上述螺桿 的螺帽構件；及裝接在該螺帽構件形成滾珠無限循環道的 G 回轉管。 上述螺桿的滾動溝槽和螺帽構件的負荷滾動溝槽是以 彼此相向形成著滾珠的負荷區域，滾珠是於該負荷區域一 邊負荷著載重一邊滾動。此外，上述回轉管是以跨越螺帽 構件上形成的數圈負荷滾動溝槽裝接在該螺帽構件，構成 可使在上述負荷區域滾動結束的滾珠從螺桿的滾動溝槽脫 離回到負荷區域的開始位置。 先前的回轉管是形成爲剖面大致U字形，具備有： 插入在螺帽構件的一對腳部；及連結該等腳部彼此的連絡 -5- 200946800 通道部，構成可使滾珠從一方的腳部朝另一方的腳部滾行 在內部。上述螺帽構件形成有—對夾著螺帽構件中心軸線 形成回轉管腳部插入用的管裝接孔’此外’該等的管裝接 孔是隔著數圈負荷滾動溝槽形成。 接著，當對該管裝接孔插入回轉管的腳部時’各腳部 會稍微突出於螺帽構件的內周圍面’構成爲可從螺桿的滾 動溝槽將滾珠撈起在回轉管內。因此，在螺桿的滾動溝槽 和螺帽構件的負荷滾動溝槽之間一邊負荷著載重一邊滾動 q 過來的滾珠，一到達回轉管腳部突出的位置時，就會釋放 載重的同時從螺桿的滾動溝槽脫離，以無負荷狀態滾動在 回轉管內回到數圈前的滾珠滾動溝槽。即，透過回轉管裝 接在螺帽構件就可形成滾珠的無限循環道。 上述負荷區域中滾珠是以螺旋狀一邊旋繞一邊滾動在 螺桿的周圍，但此時的滾珠旋繞軌道的直徑若爲d時，貝 螺桿的外徑是設定成比直徑d還小，此外，螺帽構件的內 徑是設定成比直徑d還大。其理由是，因滾動在負荷區域 〇 的滾珠中心是位於上述旋繞軌道上，所以當要在螺桿及螺 帽構件形成有比滾珠直徑還淺的滾動溝槽及負荷滾動溝槽 — 時，自然就需要有上述的設定限制。 另一方面，爲了讓滾動在負荷區域的滾珠可從螺桿的 滾動溝槽被撈起脫離該滾動溝槽，需要使回轉管的前端從 螺帽構件側超過上述旋繞軌道成爲接近螺桿側，因此先前 的滾珠螺桿裝置是構成插入在管裝接孔的回轉管的前端從 螺帽構件內周圍面往螺桿側稍微突出。 -6- 200946800 [專利文獻1]日本特開2002-98212 【發明內容】 [發明欲解決之課題] 但是’在螺帽構件設有上述管裝接孔時，該管裝接孔 其內徑至少必須比滾珠直徑還大回轉管厚度量，因此無法 避免管裝接孔大型化。由於螺帽構件的內周圍面是以指定 0 的螺紋升導角形成有負荷滾動溝槽，所以當對螺帽構件從 和其中心軸線垂直方向開設有內徑大的管裝接孔時，該管 裝接孔恐怕會干涉到鄰接的負荷滾動溝槽，特別是，當螺 桿的滾動溝槽螺紋升導長較短並且滾珠直徑較大的狀況時 ，就會難以開設管裝接孔。 此外，對螺帽構件的管裝接孔插入回轉管的腳部，使 該回轉管內的通道連續於螺帽構件的負荷滾動溝槽時，該 等的連接位置上會產生有螺帽構件和回轉管的接頭。通常 Q ’螺帽構件的負荷滾動溝槽的加工誤差爲數程度，但 回轉管的加工誤差存在有負荷滾動溝槽的數百倍程度，兩 者加工精度的不同以致上述接頭容易產生段差，恐怕會妨 礙到滾珠的順暢循環。 [用以解決課題之手段] 本發明是有鑑於上述問題點所硏創的發明，其目的是 提供一種即使是在螺桿滾動溝槽螺紋升導長較短並且滾珠 直徑較大的狀況使用回轉管還是能構築滾珠無限循環道， 200946800 並且可使回轉管和螺帽構件的負荷滾動溝槽的接頭不會對 滾珠的循環造成不良影響的滾珠螺桿裝置。 即’本發明的滾珠螺桿裝置’具備：多數滾珠；以螺 旋狀在外圍面形成有該滾珠滾動溝槽的螺桿；形成爲大致 圓筒狀的同時透過上述滾珠螺合於螺桿的螺帽構件；形成 在該螺帽構件內周圍面’與上述螺桿的滾動溝槽成相向， 和螺桿的滾動溝槽相結合形成滾珠負荷區域的螺旋狀負荷 滾動溝槽；及連通連結著上述負荷區域的始端和終端，與 q 該負荷區域相結合形成滾珠無限循環道的無負荷滾珠通道 。此外，上述無負荷滾珠通道，是由：設置在上述螺帽構 件的至少一對滾珠通過孔；可使滾珠通行在該等滾珠通過 孔之間的回轉管；及從該回轉管兩端部突出插入在上述滾 珠通過孔的滾珠撈起片所構成。 上述滾珠通過孔，是對應著上述負荷滾動溝槽端部形 成在上述螺帽構件的同時沿著該螺帽構件內周圍面的切線 方向形成。此外，該滾珠通過孔在內部具有無段差連續於 © 上述負荷滾動溝槽端部的滾珠引導面，形成比上述滾珠還 大的剖面形狀。 另一方面，上述回轉管是裝接在上述螺帽構件外側的 — 同時，具備有可使滾珠通行在上述一對滾珠通過孔之間的 滾珠返回通道。此外’該回轉管是連接於設置在上述螺帽 構件的滾珠通過孔開口緣’藉此使滾珠通過孔和滾珠返回 通道連結著。 此外，上述滾珠携起片是於上述滾珠通過孔內部形成 -8- 200946800 和上述滾珠引導面相向，與該滾珠引導面相結合形成比滾 珠直徑還稍微大內徑的滾珠通道的同時’其前端部比上述 負荷區域的滾珠旋繞軌道還突出於螺桿側。 先前的滾珠螺桿裝置爲了在螺帽構件插入回轉管的腳 部，讓該腳部與形成在螺帽構件內周圍面的負荷滾動溝槽 成爲連續，在螺帽構件設有管裝接孔，該管裝接孔最少需 要設定成和回轉管腳部相同程度的直徑。但是，本發明的 Φ 滾珠螺桿裝置是構成回轉管本身並不插入螺帽構件，只是 將從回轉管端部突出的滾珠撈起片插入螺帽構件。 即，螺帽構件設有上述滾珠撈起片插入用的滾珠通過 孔，但該滾珠通過孔是內部具有可和螺帽構件的負荷滾動 溝槽端部成無段差連續的滾珠引導面，上述滾珠撈起片和 滾珠引導面在滾珠通過孔的內部是成相向，兩者相結合形 成比滾珠直徑還稍微大內徑的滾珠通道。因此，上述滾珠 通過孔的尺寸相對於滾珠剖面形狀只要多出有滾珠撈起片 〇 剖面形狀的量就足夠，並不需要開設有如先前的滾珠螺桿 裝置的管裝接孔般的大直徑孔。即，與先前的管裝接孔相 ' 比上述滾珠通過孔的剖面積可設定成較小，因此即使是在 滾動溝槽螺紋升導長較短並且滾珠直徑較大的狀況，還是 能夠不干涉到鄰接的負荷滾動溝槽將滾珠通過孔設置在螺 帽構件。 另外，上述滾珠通過孔因是直接加工在螺帽構件，所 以其加工精度可維持成和形成在螺帽構件內周圍面的負荷 滾動溝槽的加工精度大致相同程度，即使將該滾珠通過孔 -9- 200946800 內部的滾珠引導面加工成和負荷滾動溝槽端部成連續，兩 者之間產生段差的可能性還是極低，此外即使產生段差其 尺寸也可抑制在數// m程度。因此，滾珠是可順暢通行在 負荷滾動溝槽和滾珠引導面之間，能夠使負荷區域和無負 荷滾珠通道之連接部的滾珠舉動穩定，能夠實現螺帽構件 內部的滾珠循環順暢。 再加上，上述滾珠撈起片是從螺帽構件外側插入滾珠 通過孔，其前端比負荷區域的滾珠旋繞軌道還突出於螺桿 側’因當滾動在上述負荷滾動溝槽的滾珠到達滾珠通過孔 的開口位置時，上述滾珠榜起片會讓滾珠從螺桿的滾動溝 槽脫離，使滾珠誘導往滾珠通過孔。 【實施方式】 [發明之最佳實施形態] 以下，根據附圖詳細說明本發明的滾珠螺桿裝置。 第1圖爲表示應用本發明的滾珠螺桿裝置之第一實施 形態的透視圖。該滾珠螺桿裝置，是由：多數滾珠；以螺 旋狀在外圍面形成有該等滾珠滾動溝槽的螺桿1;形成爲 大致圓筒狀的同時透過上述滾珠螺合於螺桿1的螺帽構件 2;及裝接在該螺帽構件2形成滾珠無限循環道的回轉管 3所構成。另，第1圖所示的螺帽構件2裝接有3個回轉 管3’但圖中只有1個回轉管3裝接在螺帽構件2，其他 2個回轉管3是卸下。 上述螺桿1是在外圍面以指定的螺紋升導形成有螺旋 -10- 200946800 狀的滾珠滾動溝槽，其與先前已知的滾珠螺桿裝置並無不 同。基於此，第1圖是以二點虛線的假想線繪製螺桿。上 述滾動溝槽的螺紋升導是指螺桿1 一次旋轉時滾動溝槽朝 螺桿1軸方向行進的距離，換句話說，是指螺桿1 一次旋 ' 轉使螺帽構件2朝軸方向行進的距離。該螺紋升導可根據 滾珠螺桿裝置的使用用途進行適當的設計變更。 上述螺帽構件2是形成爲大致圓筒狀具有可保持著些 φ 許間隙插入有上述螺桿1的貫通孔20，上述回轉管3是 形成爲安裝在該螺帽構件2的外圍面。此外，螺帽構件2 的軸方向的一端設有凸緣部21，螺帽構件2是構成爲利 用該凸緣部21以螺栓固定在工作台等的被安裝體。 上述螺帽構件2的內周圍面形成有螺旋狀的滾珠負荷 滾動溝槽22。該負荷滾動溝槽22是和螺桿1的滾動溝槽 相同的螺紋升導，與該滾動溝槽形成相向，藉由螺帽構件 2的負荷滾動溝槽2 2和螺桿1的滾動溝槽彼此形成相向 φ ，就形成滾珠在螺帽構件2和螺桿1之間一邊負荷著載重 一邊滾動的負荷通道。該實施形態的螺帽構件2形成有3 ' 條路徑的滾珠無限循環道，螺帽構件2的內周圍面形成有 3條負荷滾動溝槽22。各負荷滾動溝槽22是以約3.5圈 的圈數形成在螺帽構件2的內周圍面，3條負荷滾動溝槽 22是以彼此不重疊的狀態沿著螺帽構件2的軸方向設置 成串聯。但是，該等3條負荷滾動溝槽22是以連續的1 條溝槽形成在螺帽構件2的內周圍面，由下述的滚珠通過 孔及滾珠撈起片分離成3條的負荷滾動溝槽22。 -11 - 200946800 此外，螺帽構件2形成有貫通內周圍面和外圍面之間 的複數滾珠通過孔24。該等滾珠通過孔24是形成比滾珠 還大的剖面形狀，滾珠是以無負荷狀態通過該滾珠通過孔 24。另外，滾珠通過孔24是形成在上述各負荷滾動溝槽 22兩端對應的位置，夾著螺帽構件2中心軸成定位的2 ' 個滾珠通過孔24爲一對與1條負荷滾動溝槽22形成對應 著。該實施形態因上述螺帽構件2形成有3條的負荷滾動 溝槽22，所以該螺帽構件2就形成有3組共6個的滾珠 @ 通過孔24。 第2圖爲表示上述回轉管3的透視圖，第3圖爲上述 回轉管3的分解透視圖。該回轉管3是形成爲大致U字 形具備有一對腳部30和連接該等腳部30的連結部31， 形成爲跨越上述螺帽構件2中心軸線裝接在該螺帽構件2 外圍面的同時，由各腳部30覆蓋上述滾珠通過孔24。上 述腳部30和連結部31形成有比滾珠直徑還稍微大內徑的 滾珠返回通道32,該滾珠返回通道32是和螺帽構件2的 © 滾珠通過孔24連接著。滾珠返回通道32的內徑是和上述 滾珠通過孔24同樣設定成比滾珠的直徑還梢微大，構成 可使滾珠以無負荷狀態滾動在回轉管3的滾珠返回通道 ^ 32 ° 上述螺帽構件2的外圍面形成有凹處25在上述滾珠 通過孔24的周圍，當回轉管3裝接在螺帽構件2時，回 轉管3的腳部30是嵌合在該凹處25，使回轉管3定位在 螺帽構件2。螺帽構件2的凹處25的底面是形成爲平坦 -12- 200946800 面，其中央開口著上述滾珠通過孔24。另一方面， 管3的腳部30的前端面也是形成爲平坦，當回轉管 腳部30嵌合在上述凹處25時，腳部30的前端面會 於凹處25內的底面’藉此使上述滾珠通過孔24的開 形成和回轉管3的滾珠返回通道32連接著。 此外，上述回轉管3的各腳部30的前端，突出 入在上述滾珠通過孔24內部的滾珠撈起片4。該滾 φ 起片4的前端部40是貫通滾珠通過孔24從螺帽構件 內周圍面突出，形成爲位於螺桿1的滾動溝槽的內部 於此，回轉管3的各腳部30的滾珠撈起片4的形成 是在各腳部3 0的內側，又如第1圖所示，回轉管3 螺帽構件2的軸方向成傾斜安裝，所以滾珠撈起片4 設置在各腳部30的位置就成爲以指定角度朝上述腳 圍方向位移相當於該傾斜量。 如第3圖所示，上述回轉管3是由—對的上側半 〇 3a及下側半管體3b組合構成，各半管體3a、3b形 沿著滾珠的滾動方向分成爲二個半圓形剖面的滾珠返 ' 道32 °此外’上述滚珠撈起片4是具備在下側半管| 。各半管體3a、3b的接合面突設有榫33的同時，形 該榫33嵌合用的定位孔34，將一方半管體3a的榫： 合於另一方半管體3b的定位孔34，就可正確組合一 上側半管體3a及下側半管體3b。經上述組合完成的 管3是使用未圖示的管緊固構件固定在螺帽構件2。 螺帽構件2設有管緊固構件螺絲固定用的螺孔26。 回轉 3的 抵接 口緣 有插 珠撈 2的 。基 位置 是對 豎立 部周 管體 成有 回通 i 3b 成有 嵌 對的 回轉 另， -13- 200946800 另’第2圖及第3圖所示回轉管3的具體構成只是一 個例子’只要滾珠返回通道32能夠使開口在螺帽構件2 外圍面的一對滾珠返回孔2 4連結，則具體形狀等加以適 當的變更設計亦無妨。 第4圖是表示形成在螺帽構件2的滾珠通過孔24的 剖面形狀。該滾珠通過孔2 4是形成像似比滾珠5直徑還 稍微大內徑的圓朝一方向移動後的長孔狀，其內部插入有 上述滾珠撈起片4。上述滾珠通過孔24是內部具有從螺 ◎ 帽構件2的負荷滾動溝槽22連續成無段差的滾珠引導面 27’該滾珠引導面27是以比滾珠5的球面還稍微大的曲 率半徑圓弧形成半圓形。此外，該滾珠引導面27是連接 於形成在回轉管3的上側半管體3a的滾珠返回通道32。 上述滾珠引導面27是和插入在滾珠通過孔24的上述滾珠 撈起片4成相向，滾珠撈起片4也形成有半圓形的滾珠誘 導面41在上述滾珠引導面27相向的位置。接著，經由上 述滾珠引導面27和滚珠誘導面41在滾珠通過孔24內部 〇 成相向，可形成比滾珠5直徑還稍微大內徑的滾珠通道， 該滾珠通道的一端是連接於上述負荷區域，另一端是連接 於上述回轉管3的滾珠返回通道32。 另，上述滾珠通過孔24只要內部具備有和負荷滾動 溝槽22連續的滾珠引導面27 ’則其剖面形狀並不限於第 4圖所示的形狀，可根據插入的滾珠撈起片4的剖面形狀 進行適當的設計變更。 第5圖是表示該第一實施形態的負荷區域L、滾珠返 -14- 200946800 回孔24及滾珠返回通道32的連接構造剖面圖。 區域L是螺帽構件2的負荷滾動溝槽22和螺桿 溝槽1〇對向形成著，當螺桿1相對於螺帽構件 ’滾珠5是在螺帽構件2及螺桿1兩者之間一邊 重一邊滾動於上述負荷區域L。上述滾珠通過孔 對螺帽構件2的內周圍面形成在其切線方向，此 珠通過孔24內部設置的滾珠引導面27是和上述 溝槽22連續成無段差。因此，滾動在負荷區域 5，一到達上述滾珠通過孔24的開口位置時，就 撈起片4改變軌道，從負荷滾動溝槽22滾換至 面27，直接進入滾珠通過孔24的內部。 爲了順暢執行上述的負荷區域L和滾珠通過 間的滾珠5的移動，上述滾珠撈起片4的前端窗 入在螺桿1的滾動溝槽1〇內部。即’上述滾珠 是從螺帽構件2的外側插入滾珠通過孔24’其調 從螺帽構件2的內周圍面突出’進入螺桿1的 10。如第2圖及第3圖所示，滾珠撈起片4的ί 是形成近似橢圓一部份的形狀’這是爲了不接觸 10，因此將該前端部40和螺桿1的滾動溝槽10 可能成爲較小。 第5圖中，負荷區域L的中心所示的一點虛 該負荷區域L的滾珠5旋繞軌道C’即是表示滾 桿1周圍旋繞成螺旋狀的軌道。上述滾珠撈起片 部4 0是比該滾珠旋繞軌道C還突出於螺桿1側 上述負荷 1的滾動 2旋轉時 負荷著載 24是針 外，該滾 負荷滾動 L的滾珠 會由滾珠 滾珠引導 孔24之 ;40是插 撈起片4 tf端部40 滾動溝槽 [ΐί端部40 滚動溝槽 的間隙盡 線皋表示 珠5在!^ 4的前端 ,又加上 -15- 200946800 是插入在上述螺桿1的滾動溝槽10，因此當滾動在螺桿1 的滾動溝槽10的滾珠5到達滾珠撈起片4前端部40的設 定位置時，該前端部40就會從螺桿1的滾動溝槽1 〇強制 性撈起滾珠5，使滾珠5引導至滾珠誘導面41進入滾珠 通過孔24。另，第5圖所示的滾動溝槽10是形成在螺桿 1的該滾動溝槽10的溝底，因此螺桿1的外圍面是位於 滾動溝槽1 0的溝底和上述滾珠旋繞軌道C之間。 接著’從負荷區域L進入滾珠通過孔24的滾珠5是 @ 以無負荷狀態通過該滾珠通過孔24內部後，從回轉管3 的一端進入滾珠返回通道32，從回轉管3的另一端回到 相反側的滾珠通過孔24。即，是由上述滾珠通過孔24及 滾珠返回通道32構成無負荷滾珠通道，該無負荷滾珠通 道的兩端是和負荷區域L連接，藉此使滾珠5的無限循環 道具備在螺帽構件2。 其次，根據上述構成的第一實施形態滾珠螺桿裝置時 ，上述負荷滾動溝槽22是經由切削加工或硏磨加工形成 〇 在螺帽構件2的內周圍面，此外，滾珠通過孔24也是經 由電鑽開孔加工形成’因此只要使滾珠通過孔24所具備 的滾珠引導面27和負荷滾動溝槽22的端部正確吻合，就 能夠使負荷滾動溝槽22和滾珠引導面27的連接部連續成 順暢無段差。如此一來’就能夠讓通行在負荷滾動溝槽 22和滾珠通過孔24之間的滾珠5的舉動穩定，能夠順暢 執行負荷區域L和滾珠通過孔24之間的滾珠5的移動。 此外，上述回轉管3其本身是裝接在螺帽構件2的外 -16- 200946800 側’只是連接於滾珠通過孔24的開口緣，只有從回轉管 3突出的滾珠撈起片4插入在滾珠通過孔24，該滚珠撈起 片4是和滾珠通過孔2合作形成滾珠通道。因此，滾珠通 過孔24的尺寸，特別是螺帽構件2的軸方向的滾珠通過 孔24的尺寸，只要比滾珠5的直徑還稍微大的程度就足 夠’所以連續形成在負荷滾動溝槽22端部的滾珠通過孔 24不會有干涉到一圈前的負荷滾動溝槽22的顧慮，特別 φ 是有利於螺桿1的滾動溝槽10螺紋升導較小的滾珠螺桿 裝置的製作。 再加上’該實施形態的滾珠螺桿裝置的構成零件是只 有螺桿1、螺帽構件2及回轉管3以及滾珠5共4個零件 ’並且回轉管3只是連接於形成在螺帽構件2的滾珠通過 孔24開口緣，只要正確裝接在螺帽構件2外圍面就能夠 充分發揮其功能，因此組裝時不需要高精度對準位置，能 夠極爲單純地組裝滾珠螺桿裝置。 φ 其次’第6圖是圖示著應用本發明的滾珠螺桿裝置第 二實施形態相關的回轉管6。 ' 上述第一實施形態的滾珠螺桿裝置是構成爲將回轉管 3所具備的滾珠撈起片4的前端部40插入在螺桿1的滾 動溝槽10內部，藉此使滾動在負荷區域L的滾珠5從螺 桿1的滾動溝槽10脫離。但是，該第二實施形態，並不 是將滾珠撈起片4的前端插入在螺桿i的滾動溝槽內 部，而是將該前端設定在滚珠旋繞軌道C和螺桿1外圍面 之間。另，除了滾珠撈起片4的前端部構成以外，其他的 -17- 200946800 構成在第一實施形態和第二實施形態並無改變。 如第6圖所示，與第一實施形態相同從回轉管6的腳 部突出有滾珠撈起片4，該滾珠撈起片4的前端形成有滾 珠通過部45。該滾珠通過部45是形成類似橢圓一部份的 形狀。如第4圖中所示，滾珠撈起片4具備有半圓形的滾 珠誘導面41，其剖面形狀是形成爲大致U字形。因此， 爲了讓滾珠撈起片4的前端和螺桿1外圍面保持著微小間 隙而將該滾珠撈起片4的前端形成爲缺口時，則形狀類似 橢圓一部份的滾珠通過部45就會形成在滾珠撈起片4的 前端。另，回轉管6的具體構成除了上述滾珠通過部45 以外，其他是和上述第一實施形態的回轉管3相同。 第7圖是表示該第二實施形態的負荷區域L、滾珠返 回孔24及滾珠返回通道32的連接構造剖面圖。插入在螺 帽構件2的滾珠通過孔24的滾珠撈起片4其前端是超過 一點虛線所示的滾珠旋繞軌道C成爲接近螺桿1。但是， 滾珠撈起片4的前端並未插入螺桿1的滾動溝槽1〇的內 部，而是與二點虛線所示的螺桿1外圍面d1保持些許間 隙形成定位。因此，滾珠撈起片4的前端是缺口形成模仿 螺桿1外圍面的形狀，使滾珠撈起片4的前端形成有上述 的滾珠通過部45。 上述滾珠撈起片4的前端因是比滾珠旋繞軌道c還突 出於螺桿1側，所以當滾動在負荷區域L的滾珠5到達滾 珠撈起片4前端的設定位置時，滾珠5的最大外徑部位就 會接觸滾珠通過部45的內側即滾珠撈起片4所具備的滾 -18- 200946800 珠誘導面41’直接由滾珠誘導面41引導進入滾珠通過孔 24 ° 接著，從負荷區域L進入到滾珠通過孔24的滾珠5 是以無負荷狀態通過該滾珠通過孔24內部後，就從回轉 管6的一端進入滾珠返回通道32，從回轉管6的另一端 回到相反側的滾珠通過孔24。此點是和上述第一實施形 態相同。 φ 於以上構成的第二實施形態的滾珠螺桿裝置中，同樣 地只要使滾珠通過孔24所具備的滾珠引導面27和負荷滾 動溝槽22的端部正確吻合，就能夠使負荷滾動溝槽22和 滾珠引導面27的連接部連續成順暢無段差，能夠讓通行 在負荷滾動溝槽22和滾珠通過孔24之間的滾珠5的舉動 穩定，能夠順暢執行負荷區域L和滾珠通過孔24之間的 滾珠5的移動。 © 【圖式簡單說明】 第1圖爲表示應用本發明的滾珠螺桿裝置之第一實施 形態的透視圖。 第2圖爲表示第一實施形態相關的回轉管的透視圖。 第3圖爲第2圖所示回轉管的分解透視圖。 第4圖爲表示順著滾珠通過孔具有滾珠撈起片的狀態 剖面圖。 第5圖爲表示第一實施形態相關的滾珠無限循環道的 剖面圖。 -19" 200946800 第6圖爲表示應用本發明的滾珠螺桿裝置之第二實施 形態所使用的回轉管的透視圖。 第7圖爲表示第二實施形態相關的滾珠無限循環道的 剖面圖。 【主要元件符號說明】 1 :螺桿 1 0 :滾動溝槽 2 :螺帽構件 20 :貫通孔 21 :凸緣部 22 :負荷滾動溝槽 24 :滾珠通過孔 25 :凹處 2 6 :螺孔 27 :滾珠引導面 3 :回轉管 3 a :上側半管體 3 b :下側半管體 3 0 :腳部 3 1 :連結部 32 :滾珠返回通道 33 :榫 34 :定位孔 -20- 200946800200946800 IX. Description of the Invention The present invention relates to a ball screw device in which a nut member is screwed to a screw through a ball, for example, a rotary motion of a motor can be converted into a linear motion on a work table of a working machine, It is said that the type is a modification of the ball screw device in which the substantially U-shaped rotary pipe is attached to the nut member to form an infinite loop of the ball.先前 [Prior Art] A ball screw device in which a ball infinite loop is formed by using a rotary pipe is known. For example, various ball screw devices such as JP-A-2002-98212 are known. The ball screw device includes: a plurality of balls; a screw in which the spiral rolling grooves for the ball rolling are formed; and a spiral load rolling groove facing the rolling groove, and the screw is screwed to the screw a nut member; and a G-turn tube attached to the nut member to form an infinite loop of the ball. The rolling groove of the screw and the load rolling groove of the nut member are load regions in which balls are formed to face each other, and the balls roll while being loaded with the load on the load region. Further, the above-mentioned rotary pipe is attached to the nut member by a plurality of load rolling grooves formed on the nut member, and the ball can be detached from the rolling groove of the screw to the load region by the rolling end of the screw in the load region. The starting position. The conventional rotary tube is formed in a substantially U-shaped cross section, and includes: a pair of leg portions inserted into the nut member; and a connection portion connecting the leg portions to each other - 5 - 200946800, which constitutes a ball from one foot The part rolls toward the other side of the foot. The nut member is formed by forming a tube attachment hole for inserting a swivel pin portion with respect to a central axis of the nut member. Further, the tube attaching holes are formed by a plurality of load rolling grooves. Next, when the tube attachment hole is inserted into the leg portion of the rotary tube, the legs are slightly protruded from the inner peripheral surface of the nut member, and the balls are formed to be picked up from the rolling groove of the screw in the rotary tube. Therefore, between the rolling groove of the screw and the load rolling groove of the nut member, the ball that rolls q when the load is loaded is loaded, and when it reaches the position where the rotary pin protrudes, the load is released from the screw. The rolling groove is disengaged and rolls in a no-load state to return to the ball rolling groove before the number of turns in the rotating pipe. That is, an infinite circulation path of the balls can be formed by attaching the rotary pipe to the nut member. In the load region, the ball is spirally wound around the screw while being spirally wound. However, when the diameter of the ball-wound track is d, the outer diameter of the beard screw is set to be smaller than the diameter d, and the nut is further The inner diameter of the member is set to be larger than the diameter d. The reason is that since the center of the ball rolling in the load region is located on the spiral track, when the screw and the nut member are formed with a rolling groove and a load rolling groove which are shallower than the diameter of the ball, it is natural. The above setting restrictions are required. On the other hand, in order to allow the ball rolling in the load region to be lifted off the rolling groove from the rolling groove of the screw, it is necessary to make the front end of the rotary pipe from the nut member side beyond the above-mentioned winding track to be close to the screw side, thus The ball screw device is formed such that the front end of the rotary pipe inserted into the pipe attachment hole slightly protrudes from the inner peripheral surface of the nut member toward the screw side. -6-200946800 [Patent Document 1] JP-A-2002-98212 [Summary of the Invention] [The object to be solved by the invention] However, when the nut member is provided with the above-mentioned tube attachment hole, the tube attachment hole has an inner diameter of at least The thickness of the rotary tube must be larger than the diameter of the ball, so that it is not possible to increase the size of the pipe connection hole. Since the inner peripheral surface of the nut member is formed with a load rolling groove at a threaded rising angle of 0, when the nut member is opened from a tube having a large inner diameter perpendicular to a central axis thereof, The pipe fitting hole may interfere with the adjacent load rolling groove. In particular, when the rolling groove of the screw has a short lead length and a large ball diameter, it is difficult to open the pipe attaching hole. In addition, when the tube attachment hole of the nut member is inserted into the leg portion of the rotary tube so that the passage in the rotary tube is continuous with the load rolling groove of the nut member, the nut member is generated at the connection position and The joint of the rotary pipe. Generally, the machining error of the load rolling groove of the Q' nut member is several degrees, but the machining error of the rotary pipe is several hundred times that of the load rolling groove. The machining accuracy of the two is different, so that the joint is prone to a step difference. It will hinder the smooth circulation of the balls. [Means for Solving the Problems] The present invention has been made in view of the above problems, and an object of the invention is to provide a rotary tube even in a case where a screw rolling groove has a short lead length and a large ball diameter. It is also possible to construct a ball infinite circulation path, 200946800 and a ball screw device which can make the joint of the load rolling groove of the rotary pipe and the nut member do not adversely affect the circulation of the ball. That is, the "ball screw device of the present invention" includes: a plurality of balls; a screw having a spiral rolling groove formed on the outer peripheral surface in a spiral shape; and a nut member that is formed into a substantially cylindrical shape and that is screwed to the screw through the ball; a spiral load-bearing rolling groove formed in a peripheral surface of the nut member that faces the rolling groove of the screw and is combined with a rolling groove of the screw to form a ball load region; and a start end that connects and connects the load region The terminal, in combination with the load region of q, forms an unloaded ball passage of the ball infinite loop. Further, the unloaded ball passage is formed by: at least one pair of ball passage holes provided in the nut member; a ball that can pass the ball between the ball passage holes; and protruding from both ends of the rotary pipe It is composed of a ball-carrying piece inserted into the above-mentioned ball passing hole. The ball passage hole is formed in a tangential direction along the peripheral surface of the nut member while the end of the load rolling groove is formed in the nut member. Further, the ball passage hole has a stepped shape which is continuous with the end of the load rolling groove end portion, and has a larger cross-sectional shape than the ball. On the other hand, the above-mentioned rotary pipe is attached to the outside of the nut member - and has a ball return passage through which the ball can pass between the pair of ball passage holes. Further, the rotary pipe is connected to the opening edge rim of the ball passage hole provided in the nut member, whereby the ball passage hole and the ball return passage are coupled. Further, the ball-carrying piece is formed in the ball through hole to form a -8-200946800 and the ball guiding surface, and the ball guiding surface is combined with the ball guiding surface to form a ball passage having a diameter slightly larger than the ball diameter, and the front end portion thereof The ball winding track of the load region is further protruded from the screw side. In the conventional ball screw device, in order to insert the nut member into the leg portion of the rotary pipe, the leg portion is continuous with the load rolling groove formed on the inner surface of the nut member, and the nut member is provided with a pipe attachment hole. The pipe fitting hole must be set to at least the same diameter as the rotating pin. However, the Φ ball screw device of the present invention constitutes the rotary pipe itself and does not insert the nut member, but only the ball-carrying piece projecting from the end of the rotary pipe is inserted into the nut member. That is, the nut member is provided with the ball passage hole for inserting the above-described ball-carrying piece, but the ball-passing hole has a ball guide surface which is continuous with the end portion of the load rolling groove of the nut member, and the ball is continuous. The pick-up piece and the ball guiding surface are in the opposite direction in the inside of the ball passing hole, and the two combine to form a ball passage which is slightly larger than the diameter of the ball. Therefore, it is sufficient that the size of the above-mentioned ball passage hole is larger than the shape of the ball cross-section, and that the large-diameter hole like the tube attachment hole of the prior ball screw device is not required. That is, the cross-sectional area of the ball passage hole can be set smaller than the previous pipe fitting hole, so that even in the case where the rolling groove thread has a short lead length and a large ball diameter, it is possible to prevent interference. To the adjacent load rolling groove, a ball passing hole is provided in the nut member. Further, since the ball passage hole is directly machined to the nut member, the machining accuracy can be maintained to be substantially the same as the machining accuracy of the load rolling groove formed on the peripheral surface of the nut member, even if the ball passes through the hole - 9- 200946800 The inner ball guiding surface is machined to be continuous with the end of the load rolling groove, and the possibility of a step difference between the two is extremely low. Moreover, even if a step is generated, the size can be suppressed to the number of / / m. Therefore, the ball can smoothly pass between the load rolling groove and the ball guiding surface, and the ball behavior of the connection portion between the load region and the unloaded ball passage can be stabilized, and the ball circulation inside the nut member can be smoothly performed. Further, the ball-carrying piece is inserted into the ball passage hole from the outside of the nut member, and the front end thereof protrudes from the screw-side track of the load region to the screw side, because the ball rolling in the load rolling groove reaches the ball passage hole. In the open position, the above-mentioned ball-and-rods will cause the balls to disengage from the rolling grooves of the screw, causing the balls to induce the balls to pass through the holes. [Embodiment] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a ball screw device of the present invention will be described in detail with reference to the drawings. Fig. 1 is a perspective view showing a first embodiment of a ball screw device to which the present invention is applied. The ball screw device is composed of a plurality of balls, a screw 1 having the ball rolling grooves formed on the outer surface thereof in a spiral shape, and a nut member 2 which is formed into a substantially cylindrical shape and is screwed to the screw 1 through the balls. And a rotary tube 3 attached to the nut member 2 to form an infinite loop of the ball. Further, the nut member 2 shown in Fig. 1 is attached with three rotary tubes 3'. However, only one rotary tube 3 is attached to the nut member 2, and the other two rotary tubes 3 are removed. The screw 1 described above is formed with a spiral - 10 2009 46800-shaped ball rolling groove formed on the outer peripheral surface by a predetermined thread, which is different from the previously known ball screw device. Based on this, Fig. 1 is a drawing of a screw with an imaginary line of two dotted lines. The thread lift of the above-mentioned rolling groove refers to the distance that the rolling groove travels in the axial direction of the screw 1 when the screw 1 rotates once, in other words, the distance that the screw 1 rotates once and turns the nut member 2 toward the axial direction. . This thread lift can be appropriately modified depending on the intended use of the ball screw unit. The nut member 2 is formed in a substantially cylindrical shape and has a through hole 20 into which the screw 1 can be inserted while maintaining a gap therebetween. The rotary tube 3 is formed to be attached to a peripheral surface of the nut member 2. Further, one end of the nut member 2 in the axial direction is provided with a flange portion 21, and the nut member 2 is a member to be attached to the table or the like by bolts to the table or the like. A spiral ball load rolling groove 22 is formed in the inner peripheral surface of the nut member 2. The load rolling groove 22 is the same thread lift as the rolling groove of the screw 1, and is formed opposite to the rolling groove, and is formed by the load rolling groove 2 2 of the nut member 2 and the rolling groove of the screw 1 In the opposite direction φ, a load passage is formed in which the ball rolls between the nut member 2 and the screw 1 while being loaded with the load. The nut member 2 of this embodiment is formed with a ball endless circulation path of 3' paths, and three load rolling grooves 22 are formed on the inner peripheral surface of the nut member 2. Each of the load rolling grooves 22 is formed on the inner peripheral surface of the nut member 2 by a number of turns of about 3.5 turns, and the three load rolling grooves 22 are disposed along the axial direction of the nut member 2 in a state of not overlapping each other. In series. However, the three load rolling grooves 22 are formed on the inner peripheral surface of the nut member 2 by a continuous groove, and are separated into three load rolling grooves by the following ball passing holes and the ball-removing pieces. Slot 22. -11 - 200946800 Further, the nut member 2 is formed with a plurality of ball passage holes 24 penetrating between the inner peripheral surface and the outer peripheral surface. The ball passage holes 24 are formed in a cross-sectional shape larger than the balls, and the balls pass through the ball passage holes 24 in an unloaded state. Further, the ball passage holes 24 are formed at positions corresponding to both ends of the respective load rolling grooves 22, and the 2' ball passage holes 24 positioned to sandwich the central axis of the nut member 2 are a pair of one-load rolling grooves. 22 forms a correspondence. In this embodiment, since the three nut load rolling grooves 22 are formed in the nut member 2, three sets of six balls @ passage holes 24 are formed in the nut member 2. Fig. 2 is a perspective view showing the above-mentioned rotary pipe 3, and Fig. 3 is an exploded perspective view of the above-described rotary pipe 3. The rotary tube 3 is formed in a substantially U-shape and includes a pair of leg portions 30 and a coupling portion 31 that connects the leg portions 30, and is formed to be attached to the outer peripheral surface of the nut member 2 across the central axis of the nut member 2 The ball passage holes 24 are covered by the respective leg portions 30. The leg portion 30 and the joint portion 31 are formed with a ball return passage 32 which is slightly larger than the diameter of the ball, and the ball return passage 32 is connected to the © ball passage hole 24 of the nut member 2. The inner diameter of the ball return passage 32 is set to be larger than the diameter of the ball by the ball passage hole 24, and the ball is returned to the ball return passage of the rotary pipe 3 in an unloaded state. The peripheral surface of 2 is formed with a recess 25 around the ball passage hole 24, and when the rotary tube 3 is attached to the nut member 2, the leg portion 30 of the rotary tube 3 is fitted in the recess 25, so that the rotary tube 3 is positioned on the nut member 2. The bottom surface of the recess 25 of the nut member 2 is formed to be flat -12-200946800, and the ball passage hole 24 is opened at the center. On the other hand, the front end surface of the leg portion 30 of the tube 3 is also formed to be flat, and when the swivel pin portion 30 is fitted in the recess 25, the front end surface of the leg portion 30 is formed on the bottom surface in the recess 25 The opening of the ball through hole 24 is connected to the ball return passage 32 of the rotary pipe 3. Further, the front end of each leg portion 30 of the above-mentioned turning pipe 3 protrudes into the ball-carrying piece 4 inside the ball passing hole 24. The front end portion 40 of the roll φ piece 4 protrudes from the inner peripheral surface of the nut member through the ball passage hole 24, and is formed inside the rolling groove of the screw 1, whereby the balls 30 of the leg portions 30 of the rotary tube 3 are formed. The starting piece 4 is formed on the inner side of each leg portion 30, and as shown in Fig. 1, the axial direction of the nut member 2 of the rotary tube 3 is obliquely mounted, so that the ball pick-up piece 4 is provided at each leg portion 30. The position is displaced by the specified angle in the direction of the foot circumference corresponding to the amount of tilt. As shown in Fig. 3, the above-mentioned rotary pipe 3 is composed of a pair of upper half turn 3a and a lower half pipe 3b, and each half pipe 3a, 3b is divided into two semicircles along the rolling direction of the balls. The profiled section of the ball returns 'channel 32 ° in addition' the above-mentioned ball-lifting piece 4 is provided in the lower half tube | While the joint faces of the respective half pipes 3a and 3b are provided with the cymbal 33, the locating holes 34 for fitting the cymbal 33 are formed, and the cymbal of one half pipe 3a is merged with the locating hole 34 of the other half pipe 3b. Then, an upper half pipe body 3a and a lower side pipe body 3b can be correctly combined. The tube 3 completed by the above combination is fixed to the nut member 2 by a tube fastening member not shown. The nut member 2 is provided with a screw hole 26 for screwing a pipe fastening member. The abutment edge of the revolving 3 is inserted into the bead 2 . The base position is a turn-around of the vertical pipe body i 3b into a paired turn, -13- 200946800 The other specific structure of the rotary pipe 3 shown in 'Fig. 2 and 3' is just an example 'as long as the ball The return passage 32 can connect the pair of ball return holes 24 on the outer peripheral surface of the nut member 2, and the specific shape or the like can be appropriately changed. Fig. 4 is a cross-sectional view showing the ball passage hole 24 formed in the nut member 2. The ball passage hole 24 is formed in a long hole shape in which a circle having a diameter slightly larger than the diameter of the ball 5 is moved in one direction, and the ball-carrying piece 4 is inserted into the inside. The ball passage hole 24 has a ball guide surface 27' which is continuously formed from the load rolling groove 22 of the screw cap member 2 without a step. The ball guide surface 27 is a curvature radius arc which is slightly larger than the spherical surface of the ball 5. Form a semicircle. Further, the ball guiding surface 27 is connected to the ball return passage 32 formed in the upper half pipe 3a of the rotary pipe 3. The ball guiding surface 27 is opposed to the ball pick-up piece 4 inserted in the ball passing hole 24, and the ball pick-up piece 4 is also formed with a semicircular ball guiding surface 41 at a position where the ball guiding surface 27 faces each other. Then, the ball guiding surface 27 and the ball inducing surface 41 are opposed to each other in the ball passing hole 24, and a ball passage having a diameter slightly larger than the diameter of the ball 5 can be formed. One end of the ball passage is connected to the load region. The other end is a ball return passage 32 connected to the above-described rotary tube 3. Further, the ball passage hole 24 is not limited to the shape shown in Fig. 4 as long as the ball guide surface 27' continuous with the load rolling groove 22 is provided inside, and the cross section of the inserted ball-removing piece 4 can be used. Shapes are subject to appropriate design changes. Fig. 5 is a cross-sectional view showing the connection structure of the load region L, the ball return -14 - 200946800 back hole 24, and the ball return passage 32 of the first embodiment. The region L is formed by the load rolling groove 22 of the nut member 2 and the screw groove 1〇, and the screw 1 is heavy with respect to the nut member 'the ball 5 between the nut member 2 and the screw 1 Rolls on the load area L as described above. The ball passing hole is formed in the tangential direction of the inner peripheral surface of the nut member 2, and the ball guiding surface 27 provided inside the bead passing hole 24 is continuous with the groove 22 without a step. Therefore, when rolling in the load region 5, upon reaching the opening position of the ball passage hole 24, the pick-up piece 4 changes the track, rolls from the load rolling groove 22 to the face 27, and directly enters the inside of the ball passing hole 24. In order to smoothly perform the above-described movement of the ball 5 between the load region L and the ball passing, the front end of the above-described ball-lifting piece 4 is inserted into the inside of the rolling groove 1 of the screw 1. That is, the ball is inserted into the screw 1 from the outer side of the nut member 2 and inserted into the ball through hole 24' to protrude from the inner peripheral surface of the nut member 2. As shown in Fig. 2 and Fig. 3, the ί of the ball pick-up piece 4 is formed into a shape of an approximately elliptical portion 'this is for not contacting 10, so the front end portion 40 and the rolling groove 10 of the screw 1 may Become smaller. In Fig. 5, a point indicated by the center of the load region L is imaginary. The ball 5 winding track C' of the load region L is a track indicating that the roller 1 is spirally wound around the roller 1. The ball-carrying blade portion 40 is a roller 2 rotation that is greater than the ball-wound track C and protrudes from the screw 1 side of the load 1 when the load is applied. The load-bearing load 24 is outside the needle, and the roller of the roller load-rolling L is guided by the ball-ball guide hole. 24; 40 is the insertion of the lifting piece 4 tf end 40 rolling groove [ΐί end 40 rolling groove gap line 皋 indicates that the bead 5 is at the front end of !^ 4, plus -15- 200946800 is inserted In the rolling groove 10 of the screw 1, the front end portion 40 is guided from the rolling groove of the screw 1 when the ball 5 rolling in the rolling groove 10 of the screw 1 reaches the set position of the front end portion 40 of the ball-lifting piece 4. The groove 1 is forcibly picked up by the ball 5, and the ball 5 is guided to the ball inducing surface 41 into the ball passing hole 24. In addition, the rolling groove 10 shown in FIG. 5 is formed at the groove bottom of the rolling groove 10 of the screw 1, so that the peripheral surface of the screw 1 is the groove bottom of the rolling groove 10 and the ball winding track C. between. Then, the ball 5 which enters the ball passage hole 24 from the load region L is @ passes through the inside of the hole through the hole 24 in an unloaded state, and enters the ball return passage 32 from one end of the rotary pipe 3, and returns from the other end of the rotary pipe 3 The balls on the opposite side pass through the holes 24. That is, the ball passage hole 24 and the ball return passage 32 constitute an unloaded ball passage, and both ends of the unloaded ball passage are connected to the load region L, whereby the infinite circulation passage of the ball 5 is provided in the nut member 2 . According to the ball screw device of the first embodiment configured as described above, the load rolling groove 22 is formed on the inner peripheral surface of the nut member 2 by cutting or honing, and the ball passing hole 24 is also via the electric drill. The hole forming process is formed so that the connection portion between the load rolling groove 22 and the ball guiding surface 27 can be smoothly formed as long as the ball guiding surface 27 of the ball passing hole 24 and the end portion of the load rolling groove 22 are correctly fitted. No step difference. In this way, the behavior of the balls 5 passing between the load rolling groove 22 and the ball passing holes 24 can be stabilized, and the movement of the balls 5 between the load region L and the ball passing holes 24 can be smoothly performed. Further, the above-mentioned rotary pipe 3 itself is attached to the outer side of the nut member 2 on the outer-16-200946800 side. It is only connected to the opening edge of the ball passage hole 24, and only the ball-carrying piece 4 protruding from the rotary pipe 3 is inserted into the ball. Through the hole 24, the ball pick-up piece 4 cooperates with the ball through hole 2 to form a ball passage. Therefore, the size of the ball passing hole 24, particularly the size of the ball passing hole 24 in the axial direction of the nut member 2, is sufficient as long as it is slightly larger than the diameter of the ball 5, so that it is continuously formed at the end of the load rolling groove 22. The ball passage hole 24 does not interfere with the load rolling groove 22 before one turn, and in particular, φ is advantageous for the manufacture of the ball screw device in which the rolling groove 10 of the screw 1 has a small thread guide. Further, the components of the ball screw device of the embodiment are only the screw 1, the nut member 2, the rotary pipe 3, and the ball 5, and the rotary pipe 3 is only connected to the ball formed in the nut member 2. Since the opening edge of the hole 24 can be sufficiently attached to the outer surface of the nut member 2, the function can be sufficiently exhibited. Therefore, a high-precision alignment position is not required for assembly, and the ball screw device can be assembled extremely simply. φ Next Fig. 6 is a view showing a rotary pipe 6 according to a second embodiment of the ball screw device to which the present invention is applied. The ball screw device according to the first embodiment is configured such that the front end portion 40 of the ball-carrying piece 4 provided in the rotary tube 3 is inserted into the rolling groove 10 of the screw 1, thereby rolling the ball in the load region L. 5 is detached from the rolling groove 10 of the screw 1. However, in the second embodiment, the tip end of the ball-carrying piece 4 is not inserted into the inner portion of the rolling groove of the screw i, but the tip end is set between the ball-wound track C and the peripheral surface of the screw 1. Further, the configuration of the other -17-200946800 is not changed in the first embodiment and the second embodiment except for the configuration of the front end portion of the ball-recovering piece 4. As shown in Fig. 6, a ball-carrying piece 4 is protruded from the leg portion of the rotary tube 6 in the same manner as in the first embodiment, and a ball passing portion 45 is formed at the tip end of the ball-carrying piece 4. The ball passing portion 45 is formed in a shape similar to a part of an ellipse. As shown in Fig. 4, the ball-lifting piece 4 is provided with a semicircular ball-inducing surface 41 having a substantially U-shaped cross-sectional shape. Therefore, in order to make the front end of the ball-lifting piece 4 and the outer surface of the screw 1 have a small gap and the front end of the ball-lifting piece 4 is formed as a notch, the ball passing portion 45 having a shape similar to an ellipse is formed. The front end of the sheet 4 is picked up by the ball. The specific configuration of the turning pipe 6 is the same as that of the turning pipe 3 of the above-described first embodiment except for the ball passing portion 45 described above. Fig. 7 is a cross-sectional view showing the connection structure of the load region L, the ball return hole 24, and the ball return passage 32 of the second embodiment. The ball-carrying piece 4 inserted into the ball-passing hole 24 of the nut member 2 has a ball-end winding track C which is more than a dotted line and has a tip end closer to the screw 1. However, the front end of the ball-removing blade 4 is not inserted into the inner portion of the rolling groove 1 of the screw 1, but is held at a slight gap with the peripheral surface d1 of the screw 1 shown by the two-dot chain line to form a position. Therefore, the front end of the ball-lifting piece 4 is formed in a shape in which the notch forms the outer peripheral surface of the screw 1, and the ball passing portion 45 is formed at the front end of the ball-lifting piece 4. Since the front end of the ball-carrying piece 4 protrudes from the side of the screw 1 more than the ball-wound track c, the maximum outer diameter of the ball 5 when the ball 5 rolling in the load region L reaches the set position of the front end of the ball-carrying piece 4 The portion is in contact with the inside of the ball passing portion 45, that is, the roller 18-200946800 provided by the ball-lifting piece 4, and the bead-inducing surface 41' is directly guided by the ball-inducing surface 41 into the ball passing hole 24°, and then enters from the load region L. The ball 5 passing through the hole 24 passes through the inside of the hole 24 in a no-load state, and then enters the ball return passage 32 from one end of the rotary pipe 6, and returns to the ball passage hole 24 on the opposite side from the other end of the rotary pipe 6. . This point is the same as the first embodiment described above. In the ball screw device of the second embodiment configured as described above, the load rolling groove 22 can be made by similarly matching the end portions of the ball guiding surface 27 and the load rolling groove 22 provided in the ball passing hole 24 in the same manner. The connection portion with the ball guide surface 27 is continuously smooth and stepless, and the behavior of the balls 5 passing between the load rolling groove 22 and the ball passing hole 24 can be stabilized, and the load region L and the ball passing hole 24 can be smoothly executed. The movement of the ball 5 . [Embodiment of the drawings] Fig. 1 is a perspective view showing a first embodiment of a ball screw device to which the present invention is applied. Fig. 2 is a perspective view showing a rotary pipe according to the first embodiment. Fig. 3 is an exploded perspective view of the rotary pipe shown in Fig. 2. Fig. 4 is a cross-sectional view showing a state in which a ball-carrying piece is formed along a ball passing hole. Fig. 5 is a cross-sectional view showing the infinite loop path of the ball according to the first embodiment. -19 " 200946800 Fig. 6 is a perspective view showing a rotary pipe used in a second embodiment of the ball screw device to which the present invention is applied. Fig. 7 is a cross-sectional view showing the infinite loop path of the ball according to the second embodiment. [Description of main component symbols] 1 : Screw 1 0 : Rolling groove 2 : Nut member 20 : Through hole 21 : Flange portion 22 : Load rolling groove 24 : Ball passing hole 25 : Recess 2 6 : Screw hole 27 : Ball guide surface 3 : Rotary tube 3 a : Upper side half tube body 3 b : Lower side half tube body 3 0 : Foot portion 3 1 : Connection portion 32 : Ball return passage 33 : 榫 34 : Positioning hole -20 - 200946800
4 ： 40 ： 41 ： 45 ： 5 : 6 '· dl ： L ： 滾珠撈起片 前端部 滾珠誘導面 滾珠通過部 滾珠 回轉管 螺桿的外圍面 旋繞軌道 負荷區域4 : 40 : 41 : 45 : 5 : 6 '· dl : L : Ball-lifting piece Front end Ball-inducing surface Ball passing part Ball Rotating tube Peripheral surface of screw Rotating orbit Load area
-21-twenty one