201132463 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種用於連接於工具（電動工具、氣動 工具、手動工具等）的工具用插座（socket)。 【先前技術】 工具用插座通常在筒狀之插座主體的後端具有用來供 工具之夾具握持的小徑的軸桿，在前端具有與螺栓、螺母 頭部進行嵌合的插口（孔）》 例如，在專利文獻1中，公開有關於以下內容的發明 :一種旋轉工具用插座，該旋轉工具用插座在軸方向一端 側係具有電動•充電螺絲起子、氣動螺絲起子等的旋轉工 具安裝軸部，在另一端側具有供螺帽•螺栓頭等之嵌合孔 的插口部，其特徵爲：上述軸部和插口部爲獨立的個體， 軸部係爲具有耐磨損性和韌性的高合金鋼製，插口部係爲 具有耐磨損性的高合金鋼製，並且，將軸部嵌入結合到插 口部而形成一體化。 在專利文獻2中，公開有關於以下內容的發明：一種 帶有軸之插座的製造方法，該帶有軸之插座的製造方法係 在插座主體的基端突出設置有以可裝卸之方式被安裝在旋 轉工具之輸出部的多邊形軸體，其特徵爲：插座主體係由 鋁或鋁合金材料所形成，多邊形軸體係由鋼材料所形成， 在該插座主體係形成安裝孔，該安裝孔係可以使上述軸體 之基端爲突出的狀態，插入並固定該軸體，在將該安裝孔 -5- 201132463 設定爲比軸體之尺寸稍大（rough )的孔徑，因此在將上 述軸體插入該安裝孔時，不會發生軸體在壓入狀態下被插 入，而在上述插座主體上產生殘餘應力，將軸體插入、配 設在設定爲該稍大尺寸的安裝孔中，從上述安裝孔的孔軸 方向以及外周方向對該插座主體施加外壓，使插座主體產 生塑性流動，將軸體壓裝固定在安裝孔內。 此外，在專利文獻3中，公開有關於以下內容的發明 :—種旋轉工具用插座，其特徵爲：具有：插座構件（1 )，該插座構件（Ο係在軸向後端具有與該軸向平行之 孔軸線的軸部嵌合孔（la)、以及軸構件（2)，該軸構 件（2)係嵌合、固定於該插座構件（1)的上述軸部嵌合 孔（la) ’並朝後方延伸；藉由使上述軸部嵌合孔（la) 與上述軸構件（2)的嵌合在前端和後端產生變化，將上 述插座構件（1)和上述軸構件（2)在上述軸部嵌合孔（ la)中的嵌合、固定後的過盈量設定爲在上述軸部嵌合孔 (1 a )的後端側變小’在先端側增大，從而進行嵌合、固 定。 專利文獻1 :日本特開平6 - 2 2 6 6 5 1號公報 專利文獻2:日本特開平9-248635號公報 專利文獻3 :日本特開2006- 1 75523號公報 【發明內容】 [發明所欲解決之課題] 在專利文獻1〜3中任一個所公開的發明中，工具安 -6 - 201132463 裝軸桿均是被壓入到軸桿插入部中，繼而被固定的。因此 ’存在以下的問題：被安裝在電動工具上，且被作用有轉 矩的情況下，該扭轉應力容易集中，並且，工具安裝軸桿 容易保持熱量。 本發明爲了解決這些現有的技術問題，其目的即爲提 供一種：即使在因爲長時間使用，工具安裝軸桿的熱量傳 導到插座主體的情況下，仍容易釋放其熱量，並且能防止 應力集中的工具用插座。 [用以解決課題之手段] 本案發明人爲了解決上述的課題，努力硏究的結果， 獲得了下述的見解。 (A)在使用電動工具時，會產生電動機的發熱、各 部位的摩擦熱等。特別是在夏季，於室外使用的情況下， 加上太陽熱量以及其輻射熱量等外在因素，這些熱量就會 傳導到工具安裝軸桿與插座主體的接合部。此時，在將硬 質的工具安裝軸桿壓入到軟質的插座主體中之現有技術的 插座中，會因爲工具安裝軸桿和插座主體緊密結合，所以 熱量難以散發出去。通常，插座主體多使用硬度低的合金 鋼，工具安裝軸桿多使用高硬度的合金鋼，但是在接合部 位聚集熱量時，因爲這些材料的熱膨脹率不同，所以被施 加了不需要的應力，就容易發生局部的龜裂或破損。因此 ，需要將工具安裝軸桿與插座主體的接合部設定爲容易散 熱的構成。 201132463 (B) 在插座主體和工具安裝軸桿彼此固定之現有技 術的插座中，應力容易集中。這是因爲插座主體和工具安 裝軸桿被牢固地固定，所以在使用電動工具時所產生於插 座的應力難以分散，如此一來，在相同的部位就會承受多 次的應力。並且，若在螺栓的軸向和插座的軸向一致的狀 態下來進行緊固等的話，則只要考慮扭轉應力即可，但實 際上，也有時螺栓的軸向和插座的軸向會不一致，在那樣 的情況下，在接合部不僅被施加扭轉應力，而且還有來自 電動工具之打擊的衝擊力或彎曲應力等。因此，需要將工 具安裝軸桿與插座主體的接合部設定爲不固定的結構。 (C) 根據以上的見解，在工具安裝軸桿與插座主體 的接合部，需要設置適當的空間（空隙）。並且，工具安 裝軸桿與插座主體的接合部需爲廉價且容易製造的構成。 本發明之工具用插座爲鑑於上述見解者，其要旨如下 述（1 )〜（4 )所示。 (1) 一種工具用插座，係具備：插座主體，該插座 主體係分別在 一端具有插口，在另一端具有用來插入工具安裝軸桿 的軸桿插入部；以及工具安裝軸桿，該工具安裝軸桿係分 別在一端具有插座主體安裝部，在另一端具有工具安裝部 ，其特徵爲： 軸桿插入部係具有用來內置環形彈簧的環形彈簧內置 溝，並且， 插座主體安裝部係具有用來外置環形彈簧的環形彈簧 201132463 外置溝； 工具安裝軸桿係藉由嵌入到環形彈簧外置溝與環形彈 簧內置溝中的環形彈簧，而被安裝於軸桿插入部。 (2) 如上述（1)所述的工具用插座，其中，軸桿插 入部係具備：具有環形彈簧內置溝的襯套。 (3) 如上述（2)所述的工具用插座，其中，在上述 襯套的外周面係施以滾花加工。 此外’插口也可以採用六角插口或十二角插口的任何 形狀。 [發明效果] 根據本發明，即可提供一種插座，其即使在工具安裝 軸桿的熱量傳導到插座的情況下，也能容易散發該熱量， 並且能防止應力集中。因此，插座主體與工具安裝軸桿的 接合部不易受到損傷，工具壽命得以延長。 【實施方式】 以下係使用圖面來詳細說明本發明的工具用插座。 第1圖係本發明之工具用插座的分解圖。第2圖係本 發明之工具用插座的局部剖面圖。第3圖係放大顯示本發 明之工具用插座之接合部份之例子的分解剖面圖。第4圖 係放大顯示本發明之工具用插座之接合部份之例子的局部 剖面圖。 如第1〜第4圖所示，本發明的工具用插座10，例如 -9- 201132463 由插座主體20和工具安裝軸桿30所構成。並且，例如： 插座主體20整體具有筒狀的形狀，一端具有插口 21，另 —端具有軸桿插入部22 <，例如：如第3圖所示，在軸桿插 入部22，例如：從插口 21側起，具有：襯套插入部26、 傾斜部27、小徑部28、以及軸桿插入口 29。 又例如：在襯套插入部26，從插口側壓入襯套24， 將襯套24固定於襯套插入部26的內面，成爲軸桿插入部 22的一部分。在襯套24的內面係設有環形彈簧內置溝25 ，例如，如第4圖所示，在由襯套24的環形彈簧內置溝 25與插座主體的傾斜部27所構成的空間部（由第4圖的 50所表示的部分，也稱之爲環形彈簧內置溝。）係嵌'入有 環形彈簧40。 作爲襯套24，係可使用比插座主體20更硬，且比工 具安裝軸桿30軟的材料。例如，能夠使用S45C等材料。 藉由如此，即能夠消除因爲插座主體20與工具安裝軸桿 3 〇之硬度差所帶來的問題，例如，能夠消除被高硬度的工 具安裝軸桿30朝插座主體20內面壓入所造成的壓痕（表 面缺陷），以及因此所造成的偏心或應力失衡。在安裝襯 套24的情況下，以對襯套的外面施以滾花加工爲佳。這 是爲了防止襯套24從插座主體20脫落。 但是，在即使無法獲得上述的效果，降低一些插座的 壽命，也要製造廉價之插座的情況下，係可以省略襯套24 。此時，需要在插座主體20的內面預先設置環形彈簧內 置溝50。 -10- 201132463 另外，例如，如第2圖所示，在插口 21和軸桿插入 部22之間係具有空心部23，空心部23是例如在安裝、卸 下螺帽時，做爲螺桿的退避空間。 在此，插座主體20的外徑，例如是在插口 21的附近 爲最大，且朝向軸桿插入部22，呈階梯狀地縮小。插口 21的直徑沒有特別限制，可以設定爲一般所使用的12mm 〜2 4xnm左右的插口直徑。此外，在第2圖中雖顯示12角 的插口，但是也可以採用6角的插口。插座的材質沒有特 別限制，可以使用HRC爲40〜50左右之較爲軟質的合金材 料，例如爲鋁、鋁合金、硼釩鋼、鉻釩鋼、鉻鉬鋼。 另一方面，例如，如第1圖所示，工具安裝軸桿30 係在一端具有插座主體安裝部31，在另一端具有工具安裝 部3 2。插座主體安裝部3 1，例如具有斜面部3 4、環形彈 簧外置溝35、以及小徑圓柱部36。工具安裝部32例如設 有卡止溝33，在安裝到電動工具的夾具（無圖示）時可被 利用。作爲工具安裝軸桿3 0，通常可採用用於螺絲起子頭 的材料。例如，像鎳鉻鉬鋼等之HRC爲58〜62左右的硬 質合金材料。 如上所述，在本發明的工具用插座10中，插座主體 20的軸桿插入部22，係具有用來內置環形彈簧40的環形 彈簧內置溝50，工具安裝軸桿30的插座主體安裝部31， 係具有用來外置環形彈簧40的環形彈簧外置溝3 5，工具 安裝軸桿30從插座主體20的軸桿插入部22側被插入， 其前端係與環形彈簧40接觸，如果再進一步插入，環形 -11 - 201132463 彈簧40的直徑會被斜面部34逐漸壓寬，之後，一旦到達 環形彈簧外置溝35的位置時，環形彈簧40的直徑會縮小 ，環形彈簧40就會被收納在溝內。因此，環形彈簧40就 能夠以被嵌入到由環形彈簧外置溝3 5與環形彈簧內置溝 50所形成的空間部的狀態而被支持》如此一來’就能夠抑 制插座主體20與工具安裝軸桿30沿著軸向移動。 在此，作爲環形彈簧40的材質，係可使用SWC 8 0C 等一般的彈簧鋼，但是，在電動工具的作業中傳遞振動時 ，有時工具安裝軸桿30會脫落。此外，也有可能因爲生 鏽而造成性能變差。像道種現象會隨著使用次數越多愈容 易發生，對於工具用插座的壽命造成極大的影響。因此， 作爲環形彈簧的材質，最好是使用SWP-B等的鋼琴線 〇 本發明的工具用插座1 〇因爲具有這樣的構成，所以 例如如第4圖所示，能夠確保在插座主體20與工具安裝 軸桿30接觸之部份的各處具有適度的空間。意即，斜面 部34的最大直徑部與襯套24的內徑大致相同，在斜面部 34的前端部份與襯套24之間形成恒定的空間。此外，插 座主體2 0之小徑部2 8的內徑係比工具安裝軸桿3 0之小 徑圓柱部3 6的外徑稍大，所以，在該部分也可形成空間 。此外，插座主體的軸桿插入口 29的內徑係比工具安裝 軸桿30之主幹部37的外徑稍大，所以，在該部分也可形 成空間。由於存在這樣的空間，能高效率地散發插座主體 20與工具安裝軸桿30之接觸部份的發熱，並且，雖然在 -12- 201132463 這樣的接合部的各處存在空間，但插座主體20仍能夠毫 無障礙地隨著工具安裝軸桿30的旋轉而旋轉。並且，存 在適度的空間也具有防止應力集中的效果。 [產業上的利用可行性] 根據本發明，即使在工具安裝軸桿的熱量傳導到插座 的情況下，也能輕易地散發該熱量，並且能防止應力集中 。因此，可以提供一種插座主體和工具安裝軸桿的接合部 不易遭受損傷，工具壽命較長的插座。 【圖式簡單說明】 第1圖係本發明之工具用插座的分解圖。 第2圖係本發明之工具用插座的局部剖面圖。 第3圖係放大顯示本發明之工具用插座之接合部份之 例子的分解剖面圖。 第4圖係是放大顯示本發明之工具用插座之接合部份 之例子的局部剖面圖。 【主要元件符號說明】 10:本發明之工具用插座 20 :插座主體 21 :插口 22 :軸桿插入部 2 3 :空心部 -13- 201132463 2 4 ： 25 ： 26 ： 27 ： 28 ： 29 ： 30 ： 3 1: 32 : 3 3 ： 34 ： 35 ： 36 ： 40 ： 50 ： 襯套 環形彈簧內置溝 襯套插入部 傾斜部 小徑部 軸桿插入口 工具安裝軸桿 插座主體安裝部 工具安裝部 卡止溝 斜面部 環形彈簧外置溝 小徑圓柱部 環形彈簧 空間部（環形彈簧內置溝） -14-201132463 VI. Description of the Invention: [Technical Field] The present invention relates to a socket for a tool for connection to a tool (a power tool, a pneumatic tool, a hand tool, etc.). [Prior Art] The tool socket usually has a small-diameter shaft for holding the jig of the tool at the rear end of the cylindrical socket main body, and has a socket (hole) for fitting the bolt and the nut head at the front end. For example, Patent Document 1 discloses an invention for a rotating tool socket having a rotary tool mounting shaft such as an electric charging screw driver or a pneumatic screwdriver at one end side in the axial direction. The socket portion having a fitting hole for a nut, a bolt head or the like on the other end side, wherein the shaft portion and the socket portion are independent members, and the shaft portion is high in wear resistance and toughness. Made of alloy steel, the socket portion is made of high-alloy steel having wear resistance, and the shaft portion is fitted into the socket portion to be integrated. Patent Document 2 discloses an invention relating to a method of manufacturing a socket with a shaft which is provided with a detachable mounting at a base end of a socket main body. The polygonal shaft body at the output part of the rotary tool is characterized in that: the main system of the socket is formed of aluminum or aluminum alloy material, and the polygonal shaft system is formed of steel material, and a mounting hole is formed in the main system of the socket, and the mounting hole can be Inserting and fixing the shaft end of the shaft body in a state in which the base end of the shaft body is protruded, and setting the mounting hole -5-201132463 to a diameter slightly larger than the size of the shaft body, thereby inserting the shaft body When the hole is mounted, the shaft body is not inserted in the pressed state, and residual stress is generated on the socket body, and the shaft body is inserted and disposed in the mounting hole set to the slightly larger size, from the above installation. The hole axis direction and the outer circumferential direction of the hole apply an external pressure to the socket main body to cause plastic flow of the socket main body, and the shaft body is press-fitted and fixed in the mounting hole. Further, Patent Document 3 discloses an invention relating to a socket for a rotary tool, characterized in that it has a socket member (1) which has a shaft at the axial rear end and the shaft a shaft fitting hole (la) that is parallel to the axis of the hole, and a shaft member (2) that is fitted and fixed to the shaft fitting hole (la) of the socket member (1) 'and extending rearward; the socket member (1) and the shaft member (2) are changed at the front end and the rear end by fitting the shaft fitting hole (la) to the shaft member (2) The amount of interference after fitting and fixing in the shaft fitting hole (la) is set to be smaller at the rear end side of the shaft fitting hole (1 a ), and is increased at the tip end side to be embedded. [Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. [Problems to be Solved by the Invention] In the invention disclosed in any one of Patent Documents 1 to 3, the tool An-6 - 201132463 The shaft is pressed into the shaft insertion portion and then fixed. Therefore, there is a problem that the torsional stress is easily concentrated in the case where it is mounted on the power tool and is applied with torque, and In order to solve these prior art problems, the present invention aims to provide a method for easily releasing even when the heat of the tool mounting shaft is transmitted to the socket main body due to long-term use. In order to solve the above problems, the inventors of the present invention have obtained the following findings in order to solve the above problems. (A) Using a power tool When it is generated, the heat generated by the motor, the friction heat of each part, etc., especially in the summer, when externally used, plus the external factors such as solar heat and radiant heat, the heat is transmitted to the tool mounting shaft. a joint with the socket body. At this time, the prior art of pressing a rigid tool mounting shaft into a soft socket body In the socket, the heat is difficult to dissipate because the tool mounting shaft and the socket body are tightly combined. Usually, the socket body is mostly made of alloy steel with low hardness, and the tool mounting shaft mostly uses high hardness alloy steel, but gathers at the joint. In the case of heat, since the thermal expansion rates of these materials are different, it is easy to cause local cracking or breakage when unnecessary stress is applied. Therefore, it is necessary to set the joint portion between the tool mounting shaft and the socket main body to be easy to dissipate heat. 201132463 (B) In the prior art socket in which the socket main body and the tool mounting shaft are fixed to each other, the stress is easily concentrated. This is because the socket main body and the tool mounting shaft are firmly fixed, so that when the power tool is used, The stress of the socket is difficult to disperse, and as a result, multiple stresses are applied to the same portion. In addition, if tightening is performed in a state where the axial direction of the bolt and the axial direction of the socket are aligned, the torsional stress may be considered. However, in actuality, the axial direction of the bolt may not coincide with the axial direction of the socket. In such a case, not only torsional stress but also impact force or bending stress from the impact of the electric tool is applied to the joint portion. Therefore, it is necessary to set the joint portion of the tool mounting shaft and the socket main body to an unfixed structure. (C) According to the above findings, it is necessary to provide an appropriate space (gap) at the joint between the tool mounting shaft and the socket main body. Further, the joint portion between the tool mounting shaft and the socket main body needs to be inexpensive and easy to manufacture. The tool socket of the present invention is based on the above findings, and the gist thereof is as follows (1) to (4). (1) A socket for a tool, comprising: a socket main body having a socket at one end, a shaft insertion portion for inserting a tool mounting shaft at the other end; and a tool mounting shaft, the tool mounting The shaft has a socket body mounting portion at one end and a tool mounting portion at the other end, wherein the shaft insertion portion has an annular spring built-in groove for a built-in ring spring, and the socket body mounting portion has a function. The annular spring 201132463 of the external annular spring is externally grooved; the tool mounting shaft is attached to the shaft insertion portion by an annular spring embedded in the outer groove of the annular spring and the inner groove of the annular spring. (2) The tool socket according to the above (1), wherein the shaft insertion portion includes a bushing having a ring spring built-in groove. (3) The tool socket according to the above (2), wherein the outer peripheral surface of the bush is knurled. In addition, the socket can be any shape with a hexagonal socket or a twelve-point socket. [Effect of the Invention] According to the present invention, it is possible to provide a socket which can easily dissipate the heat even when the heat of the tool mounting shaft is conducted to the socket, and can prevent stress concentration. Therefore, the joint portion between the socket main body and the tool mounting shaft is less likely to be damaged, and the tool life is prolonged. [Embodiment] Hereinafter, the tool socket of the present invention will be described in detail using the drawings. Fig. 1 is an exploded view of the socket for a tool of the present invention. Fig. 2 is a partial cross-sectional view showing a socket for a tool of the present invention. Fig. 3 is an exploded cross-sectional view showing an enlarged example of a joint portion of the socket for a tool of the present invention. Fig. 4 is a partial cross-sectional view showing an enlarged example of a joint portion of the socket for a tool of the present invention. As shown in Figs. 1 to 4, the tool socket 10 of the present invention, for example, -9-201132463, is composed of a socket main body 20 and a tool mounting shaft 30. Further, for example, the socket main body 20 has a cylindrical shape as a whole, and has a socket 21 at one end and a shaft insertion portion 22 at the other end. For example, as shown in Fig. 3, at the shaft insertion portion 22, for example, The socket 21 has a bush insertion portion 26, an inclined portion 27, a small diameter portion 28, and a shaft insertion opening 29. Further, for example, in the bushing insertion portion 26, the bushing 24 is press-fitted from the socket side, and the bushing 24 is fixed to the inner surface of the bushing insertion portion 26 to be a part of the shaft insertion portion 22. An annular spring inner groove 25 is formed on the inner surface of the bushing 24. For example, as shown in Fig. 4, the space portion formed by the annular spring inner groove 25 of the bushing 24 and the inclined portion 27 of the socket main body (by The portion indicated by 50 in Fig. 4 is also referred to as a ring spring built-in groove.) A ring spring 40 is embedded. As the bushing 24, a material which is harder than the socket main body 20 and softer than the tool mounting shaft 30 can be used. For example, a material such as S45C can be used. By doing so, it is possible to eliminate the problem caused by the difference in hardness between the socket main body 20 and the tool mounting shaft 3, for example, it is possible to eliminate the pressing of the tool mounting shaft 30 with high hardness toward the inner surface of the socket main body 20. Indentation (surface defects), and thus the resulting eccentricity or stress imbalance. In the case of the bushing 24, it is preferred to apply knurling to the outer surface of the bushing. This is to prevent the bushing 24 from coming off the socket main body 20. However, in the case where the above-described effects are not obtained, the life of some of the sockets is lowered, and the inexpensive socket is to be manufactured, the bushing 24 can be omitted. At this time, it is necessary to provide the annular spring inner groove 50 in advance on the inner surface of the socket main body 20. -10- 201132463 Further, for example, as shown in Fig. 2, a hollow portion 23 is provided between the socket 21 and the shaft insertion portion 22, and the hollow portion 23 is used as a screw, for example, when the nut is attached and detached. Retreat space. Here, the outer diameter of the socket main body 20 is, for example, the largest in the vicinity of the socket 21, and is reduced toward the shaft insertion portion 22 in a stepwise manner. The diameter of the socket 21 is not particularly limited, and can be set to a diameter of about 12 mm to 2 4 x nm which is generally used. Further, although a socket of 12 corners is shown in Fig. 2, a socket of 6 corners may be used. The material of the socket is not particularly limited, and a relatively soft alloy material having an HRC of about 40 to 50, such as aluminum, aluminum alloy, boron vanadium steel, chrome vanadium steel, or chrome molybdenum steel, can be used. On the other hand, for example, as shown in Fig. 1, the tool mounting shaft 30 has a socket main body mounting portion 31 at one end and a tool mounting portion 32 at the other end. The socket main body mounting portion 3 1, for example, has a slope portion 34, a ring spring outer groove 35, and a small diameter cylindrical portion 36. The tool attachment portion 32 is provided with, for example, a locking groove 33, and can be used when attached to a jig (not shown) of the electric power tool. As the tool for mounting the shaft 30, a material for the screwdriver bit can usually be used. For example, a HRC such as nickel-chromium-molybdenum steel has a hard alloy material of about 58 to 62. As described above, in the tool socket 10 of the present invention, the shaft insertion portion 22 of the socket main body 20 has the annular spring built-in groove 50 for the built-in ring spring 40, and the socket main body mounting portion 31 of the tool mounting shaft 30. There is an annular spring outer groove 35 for the external annular spring 40, and the tool mounting shaft 30 is inserted from the shaft insertion portion 22 side of the socket main body 20, and the front end thereof is in contact with the ring spring 40, if further Insertion, ring-11 - 201132463 The diameter of the spring 40 is gradually widened by the inclined surface portion 34. Thereafter, once the position of the annular spring outer groove 35 is reached, the diameter of the ring spring 40 is reduced, and the ring spring 40 is accommodated. Inside the ditch. Therefore, the ring spring 40 can be supported in a state of being fitted into the space portion formed by the annular spring outer groove 35 and the ring spring inner groove 50. Thus, the socket main body 20 and the tool mounting shaft can be suppressed. The rod 30 moves in the axial direction. Here, as the material of the ring spring 40, a general spring steel such as SWC 8 0C can be used. However, when the vibration is transmitted during the operation of the electric tool, the tool mounting shaft 30 may fall off. In addition, it is also possible that performance is deteriorated due to rust. Like the phenomenon, the more it is used, the more likely it is to occur, which has a great impact on the life of the tool socket. Therefore, it is preferable to use a piano cord of the SWP-B or the like as the material of the ring spring. Since the tool socket 1 of the present invention has such a configuration, for example, as shown in Fig. 4, it is possible to secure the socket body 20 and There is a moderate amount of space throughout the portion where the tool mounting shaft 30 contacts. That is, the maximum diameter portion of the slope portion 34 is substantially the same as the inner diameter of the bushing 24, and a constant space is formed between the front end portion of the slope portion 34 and the bushing 24. Further, the inner diameter of the small diameter portion 28 of the socket main body 20 is slightly larger than the outer diameter of the small diameter cylindrical portion 36 of the tool mounting shaft 30, so that a space can be formed in this portion. Further, the inner diameter of the shaft insertion opening 29 of the socket main body is slightly larger than the outer diameter of the trunk portion 37 of the tool mounting shaft 30, so that a space can be formed in this portion. Since such a space exists, heat generation of the contact portion between the socket main body 20 and the tool mounting shaft 30 can be efficiently dissipated, and although there is space everywhere in the joint portion such as -12-201132463, the socket main body 20 remains It is possible to rotate with the rotation of the tool mounting shaft 30 without any obstacle. Moreover, the presence of an appropriate space also has the effect of preventing stress concentration. [Industrial Applicability] According to the present invention, even when the heat of the tool mounting shaft is conducted to the socket, the heat can be easily dissipated and stress concentration can be prevented. Therefore, it is possible to provide a socket in which the joint portion of the socket main body and the tool mounting shaft is less likely to be damaged and the tool life is long. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded view of a socket for a tool of the present invention. Fig. 2 is a partial cross-sectional view showing the socket for a tool of the present invention. Fig. 3 is an exploded cross-sectional view showing an enlarged example of a joint portion of the socket for a tool of the present invention. Fig. 4 is a partial cross-sectional view showing an enlarged example of a joint portion of the socket for a tool of the present invention. [Description of main component symbols] 10: Tool socket 20 of the present invention: socket main body 21: socket 22: shaft insertion portion 2 3 : hollow portion - 13 - 201132463 2 4 : 25 : 26 : 27 : 28 : 29 : 30 : 3 1:32 : 3 3 : 34 : 35 : 36 : 40 : 50 : Bushing ring spring built-in groove bushing insertion part inclined part small diameter part shaft insertion port tool mounting shaft socket main body mounting part tool mounting part card Groove inclined surface annular spring external groove small diameter cylindrical portion annular spring space portion (annular spring built-in groove) -14-