JP2017061018A

JP2017061018A - Impact tool

Info

Publication number: JP2017061018A
Application number: JP2015188169A
Authority: JP
Inventors: 大谷　隆児; Koji Otani; 隆児大谷; 光政水野; Mitsumasa Mizuno; 関野　文昭; Fumiaki Sekino; 文昭関野; 次夫清水; Tsugio Shimizu
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2017-03-30
Anticipated expiration: 2035-09-25
Also published as: JP6543806B2

Abstract

PROBLEM TO BE SOLVED: To provide an impact tool capable of connecting a tool bit to an output shaft with a high holding force and effectively transferring a rotation impact to the tool bit over long time of use.SOLUTION: The present invention concerns an impact tool applying a rotation impact to a tool bit having a socket in an end portion. The impact tool comprises: a housing provided with the output shaft driven to rotate about an axis; an impact mechanism applying the rotation impact to the output shaft; and a loosening prevention mechanism. The loosening prevention mechanism is configured from at least one wedge movable along an axial direction of a plug on a peripheral surface of the plug and an operation handle disposed on an outer circumference of the output shaft. The operation handle is configured to be connected to the wedge to move the wedge between an attachment/detachment position and a lock position.SELECTED DRAWING: Figure 1

Description

本発明は、工具ビットを用いてネジやボルト、ナットなどの締め付けや締め戻しを行う際に、工具ビットへ回転インパクトを付与するインパクト工具に関するものである。 The present invention relates to an impact tool that imparts a rotational impact to a tool bit when a tool bit is used to tighten or tighten a screw, bolt, or nut.

特許文献１のインパクト工具では、回転駆動される断面が角形の出力軸と、この出力軸に装着される工具ビットと着脱構造を開示している。工具ビットは出力軸が嵌め込まれるソケットを有し、出力軸に固定された弾性部材の一部が、ソケットの内面に設けた穴内に弾性的に嵌め込まれることで、出力軸と工具ビットとの間の相対回転を無くして、出力軸に加えられる回転インパクトを工具ビットへ効果的に伝達することが期待されている。 The impact tool disclosed in Patent Document 1 discloses an output shaft having a square section that is rotationally driven, a tool bit mounted on the output shaft, and a detachable structure. The tool bit has a socket into which the output shaft is fitted, and a part of the elastic member fixed to the output shaft is elastically fitted into a hole provided in the inner surface of the socket, so that there is a gap between the output shaft and the tool bit. Therefore, it is expected that the rotational impact applied to the output shaft is effectively transmitted to the tool bit.

特開２００６−７３８９号公報JP 2006-7389 A

特許文献１のインパクト工具は、出力軸の外周に配置したばね片の径方向への変位を伴う弾性力によって出力軸を工具ビットに保持させる構造となっている。このため、出力軸の回転に伴って、ばね片にねじれが生じやすく、長期の使用でばね片に変形が生じ、弾性力に基づく結合が弱くなり易いという問題がある。
本発明は、上記の問題点に鑑みてなされたものであり、高い保持力で工具ビットを出力軸に結合できて、長期の使用に亘って、効果的に回転インパクトを工具ビットへ伝達することができるインパクト工具を提供することである。 The impact tool of Patent Document 1 has a structure in which the output shaft is held by the tool bit by an elastic force accompanied by a radial displacement of a spring piece arranged on the outer periphery of the output shaft. For this reason, there is a problem that the spring piece is easily twisted with rotation of the output shaft, the spring piece is deformed after long-term use, and the coupling based on the elastic force tends to be weakened.
The present invention has been made in view of the above-described problems, and is capable of coupling a tool bit to an output shaft with a high holding force and effectively transmitting a rotational impact to the tool bit over a long period of use. It is to provide an impact tool that can be used.

本発明は、ソケットを端部に有する工具ビットに回転インパクトを与えるインパクト工具である。インパクト工具は、軸の周りで回転駆動される出力軸を備えたハウジングと、前記出力軸へ回転インパクトを付与するインパクト機構と、緩み止め機構とを備える。前記出力軸はその軸方向の一端にプラグを有し、このプラグが工具ビットのソケットに着脱自在に嵌まり込んで工具ビットへ回転運動を伝達するものである。記緩み止め機構は、プラグの周面でプラグの軸方向に沿って移動自在の少なくとも一つのくさびと、出力軸の外周に配置された操作ハンドルとで構成される。緩み止め機構の操作ハンドルはくさびと結合されて、くさびを着脱位置とロック位置との間移動させるように構成される。着脱位置では、くさびとソケットの内周面との間にクリアランスが残って前記プラグがソケットへこのクリアランスの範囲内でプラグが工具ビットに対してわずかな相対回転が許容され、ロック位置では、くさびがプラグ外周面とソケットの内周面との間に密に挟みこまれてソケットに対するプラグの相対回転が許容されないようになったことを特徴とする。 The present invention is an impact tool that gives a rotational impact to a tool bit having a socket at an end. The impact tool includes a housing having an output shaft that is driven to rotate around a shaft, an impact mechanism that imparts a rotational impact to the output shaft, and a locking mechanism. The output shaft has a plug at one end in the axial direction, and the plug is detachably fitted into the socket of the tool bit to transmit the rotational motion to the tool bit. The locking mechanism includes at least one wedge that is movable along the axial direction of the plug on the peripheral surface of the plug, and an operation handle disposed on the outer periphery of the output shaft. The operating handle of the locking mechanism is coupled to the wedge and is configured to move the wedge between the attach / detach position and the lock position. In the attachment / detachment position, a clearance remains between the wedge and the inner peripheral surface of the socket, and the plug is allowed to rotate slightly relative to the tool bit within the clearance within the clearance range. Is tightly sandwiched between the outer peripheral surface of the plug and the inner peripheral surface of the socket, so that the relative rotation of the plug with respect to the socket is not allowed.

本発明に係るインパクト工具は、工具ビットへ高い保持力で出力軸を結合して、工具ビットへ効果的に回転インパクトを伝達することができる。 The impact tool according to the present invention can effectively transmit the rotational impact to the tool bit by coupling the output shaft to the tool bit with a high holding force.

本発明の一実施形態に係るインパクト工具を示す概略断面図。1 is a schematic cross-sectional view showing an impact tool according to an embodiment of the present invention. （ａ）同上のインパクト工具が備える緩み止め機構を示す概略断面図。（ｂ）同上の緩み止め機構の動作を示す断面図。(A) The schematic sectional drawing which shows the locking mechanism with which an impact tool same as the above is provided. (B) Sectional drawing which shows operation | movement of a locking mechanism same as the above. （ａ）同上の緩み止め機構を構成するくさびがロック位置にある状態を示す概略断面図。（ｂ）同上のくさびが着脱位置にある状態を示す概略断面図。(A) The schematic sectional drawing which shows the state which has the wedge which comprises the locking mechanism in the same as the above. (B) The schematic sectional drawing which shows the state which has a wedge same as the above in an attachment or detachment position. 同上の変形例における軸方向に対して垂直方向の概略分解図であるIt is a schematic exploded view perpendicular to the axial direction in the modified example （ａ）同上のゆるみ止め機構における変形例における軸方向に対して垂直方向の概略分解図である。（ｂ）同上のゆるみ止め機構におけるおける軸方向に対して垂直方向の概略分解図である。(A) It is a schematic exploded view of a perpendicular | vertical direction with respect to the axial direction in the modification in the locking mechanism same as the above. (B) It is a schematic exploded view of a perpendicular | vertical direction with respect to the axial direction in the locking mechanism in the same as the above. （ａ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す概略断面図。（ｂ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す概略断面図。(A) The schematic sectional drawing which shows the locking mechanism used in the further another modified aspect of the impact tool same as the above. (B) The schematic sectional drawing which shows the locking mechanism used in the further another modified aspect of the impact tool same as the above. （ａ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す分解斜視図。（ｂ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す概略断面図。(A) The disassembled perspective view which shows the locking mechanism used in the further another change aspect of the impact tool same as the above. (B) The schematic sectional drawing which shows the locking mechanism used in the further another modified aspect of the impact tool same as the above. （ａ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す分解斜視図。（ｂ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す断面図。(A) The disassembled perspective view which shows the locking mechanism used in the further another change aspect of the impact tool same as the above. (B) Sectional drawing which shows the locking mechanism used in the further another change aspect of an impact tool same as the above. （ａ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す斜視図。（ｂ）同上のインパクト工具の更に他の変更態様で使用する緩み止め機構を示す断面図。(A) The perspective view which shows the locking mechanism used in the further another change aspect of an impact tool same as the above. (B) Sectional drawing which shows the locking mechanism used in the further another change aspect of an impact tool same as the above.

本発明にかかるインパクト工具１は、工具ビット１００を介してボルトやナットの締め付け又は緩める際に、工具ビット１００へ回転インパクトを付与することで大きなトルクを発生させて締め付けや緩めを容易に行う工具である。
本発明の一実施形態に係るインパクト工具１は、図１に示すように、外郭を成し内部にモータ８を備えるハウジング２と、ハウジング２の前端部に突出し軸の周りでモータ８によって回転駆動される出力軸２１と、回転インパクトを出力軸２１に与えるインパクト機構とで構成される。
インパクト機構は、ハンマー４とアンビル６とを備える。ハンマー４は、モータ８により回転する駆動軸３にスライド自在に嵌合され、駆動軸３は駆動軸カム溝３ａを有し、ハンマー４はハンマーカム溝４ａを有する。駆動軸カム溝３ａとハンマーカム溝４ａに挟まれるように嵌合させた鋼球５を介して駆動軸３の回転運動がハンマー４に伝達され、更にハンマー４と噛合したアンビル６を介して出力軸２１へ回転運動が伝達される。作業中に出力軸２１にある一定以上の荷重が作用し、その回転が鈍った場合には、鋼球５がハンマーカム溝４ａに沿って移動してハンマー４を駆動軸３上で後退させて、ハンマー４とアンビル６の噛合が外れる。この時ハンマー４は回転運動を続行しているのに対して、出力軸２１に固定のアンビル６はその回転運動が停止された状態となる。ハンマー４の後方にはコイル状のスプリング７が配されており、スプリング７の付勢力によりハンマー４は押し戻されて再びアンビル６と噛合し、その際に、停止しているアンビル６に対してハンマー４が自らの回転による打撃を与える。打撃時の衝撃により反力を受けたハンマー４は、駆動軸３の回転方向と逆方向に回転しながら再度後退するが、スプリング７による付勢力と駆動軸３の回転力によってこの回転及び後退は減衰されて次の打撃動作へと移行する。このようにして、締め付け或いは緩め作業中である一定以上の荷重が生じた場合には、回転インパクトが繰り返して出力軸２１に加えられる。
出力軸２１は、アンビル６より回転インパクトを受けて、工具ビット１００に回転インパクトを伝達する。出力軸２１は、ハウジング２の前端側に設けられ、工具ビット１００のソケットに挿着された状態で、ボルトやナットの締め付け・緩めを行う。 The impact tool 1 according to the present invention is a tool for easily tightening or loosening by generating a large torque by applying a rotational impact to the tool bit 100 when a bolt or nut is tightened or loosened via the tool bit 100. It is.
As shown in FIG. 1, an impact tool 1 according to an embodiment of the present invention includes a housing 2 that forms an outer shell and includes a motor 8 inside, and is driven to rotate by a motor 8 around a shaft that projects from the front end of the housing 2 Output shaft 21 and an impact mechanism that gives a rotational impact to the output shaft 21.
The impact mechanism includes a hammer 4 and an anvil 6. The hammer 4 is slidably fitted to a drive shaft 3 rotated by a motor 8, the drive shaft 3 has a drive shaft cam groove 3a, and the hammer 4 has a hammer cam groove 4a. The rotational motion of the drive shaft 3 is transmitted to the hammer 4 through the steel ball 5 fitted so as to be sandwiched between the drive shaft cam groove 3a and the hammer cam groove 4a, and further output through the anvil 6 meshed with the hammer 4. A rotational motion is transmitted to the shaft 21. When a certain load or more is applied to the output shaft 21 during the operation and the rotation of the output shaft 21 is slow, the steel ball 5 moves along the hammer cam groove 4a and the hammer 4 is moved backward on the drive shaft 3. The engagement between the hammer 4 and the anvil 6 is released. At this time, the hammer 4 continues to rotate, whereas the anvil 6 fixed to the output shaft 21 is stopped from rotating. A coiled spring 7 is arranged behind the hammer 4, and the hammer 4 is pushed back by the urging force of the spring 7 and meshes with the anvil 6 again. 4 gives a blow by its own rotation. The hammer 4 that has received a reaction force due to the impact at the time of impact is retracted again while rotating in the direction opposite to the rotation direction of the drive shaft 3. It is attenuated and moves to the next striking motion. In this way, when a certain load or more occurs during the tightening or loosening operation, the rotational impact is repeatedly applied to the output shaft 21.
The output shaft 21 receives a rotational impact from the anvil 6 and transmits the rotational impact to the tool bit 100. The output shaft 21 is provided on the front end side of the housing 2, and tightens and loosens bolts and nuts while being inserted into the socket of the tool bit 100.

次に、出力軸２１へ工具ビット１００を保持する機構について説明する。
インパクト工具１は、図１に示すように、工具ビット１００を出力軸２１へ保持する機構として、緩み止め機構を備えます。出力軸２１の先端に形成されたプラグ２２が工具ビッ
ト１００のソケットに着脱自在に嵌まり込んで工具ビット１００へ回転運動を伝達します。緩み止め機構は、図２（ａ）に示すように、くさび３０と操作ハンドル４０とで構成され、工具ビット１００へのプラグ２２のへの着脱が行われる着脱位置と、工具ビット１００をプラグ２２へ強固に保持するロック位置とを選択するように構成される。着脱位置では、プラグ２２がソケットへ多少のクリアランスを有する状態で嵌め込まれて、この隙間の範囲内でプラグ２２がソケット孔に対してわずかに相対回転が許容される。ロック位置では、ソケット内でのプラグ２２の相対回転が許容されず、出力軸２１に加わる回転インパクトがずれなく工具ビット１００に伝達される。
以下、図２（ａ）（ｂ）を参照してプラグ２２と緩み止め機構の詳細を述べる。プラグ２２は先端側に向かって先細りとなる矩形状断面を有し、４つの外周面の内、対向する１組の外周面が傾斜面とされている。 Next, a mechanism for holding the tool bit 100 to the output shaft 21 will be described.
As shown in Fig. 1, the impact tool 1 is equipped with a locking mechanism as a mechanism for holding the tool bit 100 to the output shaft 21. A plug 22 formed at the tip of the output shaft 21 is detachably fitted into the socket of the tool bit 100 to transmit the rotational motion to the tool bit 100. As shown in FIG. 2A, the locking mechanism includes a wedge 30 and an operation handle 40, and an attachment / detachment position where the plug 22 is attached to and detached from the tool bit 100, and the tool bit 100 is plugged into the plug 22. And a lock position to hold firmly. In the attachment / detachment position, the plug 22 is fitted into the socket with some clearance, and the plug 22 is allowed to rotate slightly relative to the socket hole within the gap. In the locked position, relative rotation of the plug 22 in the socket is not allowed, and the rotational impact applied to the output shaft 21 is transmitted to the tool bit 100 without deviation.
The details of the plug 22 and the locking mechanism will be described below with reference to FIGS. The plug 22 has a rectangular cross section that tapers toward the distal end side, and one set of opposed outer peripheral surfaces among the four outer peripheral surfaces is inclined.

緩み止め機構のくさび３０は、２つの傾斜面に配置され、操作ハンドル４０は、出力軸２１の外周面に配置されて前端でくさび３０と結合し、後端の内周面が出力軸２１へ結合している。 The wedge 30 of the locking mechanism is disposed on two inclined surfaces, and the operation handle 40 is disposed on the outer peripheral surface of the output shaft 21 and is coupled to the wedge 30 at the front end, and the inner peripheral surface of the rear end is connected to the output shaft 21. Are connected.

くさび３０は、傾斜面と接する内接触面３１と、工具ビット１００と接触する外接触面３２とを有し、後端に操作ハンドル４０と結合する結合凸部３３を備える。内接触面３１と外接触面３２とで構成されるくさび３０の厚みは、前端に向かって厚く形成され、内接触面３１はプラグの傾斜面と接する傾斜面になっており、外接触面３２はソケットの内周面と接するよう平坦面である。結合凸部３３は、径方向外方へ突出し、操作ハンドル４０の前端内面の周溝４３に嵌合する。
操作ハンドル４０は、後端部で出力軸２１とネジ結合され、前端部でくさび３０の後端に結合することで、くさび３０をプラグ２２の傾斜面上に保持する。くさび３０は、操作ハンドル４０を出力軸２１の回りで回転させることで、着脱位置とロック位置との間で、プラグ２２に対して軸方向に移動し、図３（ａ）に示すように着脱位置ではくさび３０が工具ビット１００のソケットの内周面から離れて隙間を残し、図３（ｂ）に示すように、ロック位置ではくさび３０がソケットの内周面及びプラグ２２に密接して、工具ビット１００を出力軸２１へ相対回転不能に結合する。
図２（ｂ）に示すように、くさび３０はＵ字形断面を有し、ベースの両端から外方に突出する突起３４を有する。くさび３０がロック位置に移動すると、突起３４が工具ビット１００のソケットの内面における周方向に離間した２つの点に圧接する。これにより、くさび３０がロック位置に移動したとき、各くさび３０がソケット内周の凸面に周方向に離れた２点で密接することができ、工具ビット１００との結合力を高める。
次に、図３（ａ）（ｂ）を参照して、緩み止め機構によって、くさび３０を着脱位置とロック位置へと選択的に切り替える動作を説明する。工具ビット１００をインパクト工具１に取り付ける場合、プラグ２２を工具ビット１００のソケットに挿入する。この時点では、図３（ａ）に示すように、くさび３０はプラグ２２の先端側となる着脱位置に保持され、くさび３０とソケットの内周面との間に若干の隙間が残され、工具ビット１００のプラグ２２への着脱操作が容易に行われる。インパクト工具１を起動させる前に、図３（ｂ）に示すように、操作ハンドル４０を回転させて、くさび３０を出力軸２１の後端側へ軸方向に沿ってスライドさせることでロック位置に移動させる。このロック位置では、くさび３０がソケットの内周面に圧接して、ソケット内でのくさび３０のがたつきをなくして、回転インパクトが効果的に工具ビット１００に伝達される。
上述のように、プラグ２２の外周に配置したくさび３０が着脱位置とロック位置との間で出力軸の軸方向に沿って移動するため、着脱位置では工具ビットの着脱が容易に行え、ロック位置では、くさび結合によって、工具ビット１００を出力軸２１へ相対回転不能に強固に結合でき、回転インパクトを確実に工具ビット１００へ伝達することが可能となる。これに関連して、図４に示すように、くさび３０が配置されないプラグ２２の外周面に、ソケット内周の凸面へ周方向に離れた２点で接する突起３４を形成されていてもよい。
本実施形態では、４つの外周面の内、対向する１組の外周面が傾斜面とされているが、本発明はこの形態に限定されるものではなく、全ての外周面を傾斜面として、各傾斜面にくさび３０を配置してもよい。 The wedge 30 has an inner contact surface 31 in contact with the inclined surface and an outer contact surface 32 in contact with the tool bit 100, and includes a coupling convex portion 33 coupled to the operation handle 40 at the rear end. The wedge 30 composed of the inner contact surface 31 and the outer contact surface 32 is formed thicker toward the front end, and the inner contact surface 31 is an inclined surface in contact with the inclined surface of the plug. Is a flat surface in contact with the inner peripheral surface of the socket. The coupling convex portion 33 projects outward in the radial direction and fits into the circumferential groove 43 on the inner surface of the front end of the operation handle 40.
The operation handle 40 is screw-coupled to the output shaft 21 at the rear end portion and is coupled to the rear end of the wedge 30 at the front end portion, thereby holding the wedge 30 on the inclined surface of the plug 22. The wedge 30 moves in the axial direction with respect to the plug 22 between the attachment / detachment position and the lock position by rotating the operation handle 40 around the output shaft 21, and is attached / detached as shown in FIG. 3 (a). In the position, the wedge 30 is separated from the inner peripheral surface of the socket of the tool bit 100, leaving a gap, and as shown in FIG. 3B, the wedge 30 is in close contact with the inner peripheral surface of the socket and the plug 22, as shown in FIG. The tool bit 100 is coupled to the output shaft 21 so as not to be relatively rotatable.
As shown in FIG. 2B, the wedge 30 has a U-shaped cross section and has protrusions 34 protruding outward from both ends of the base. When the wedge 30 moves to the locked position, the protrusion 34 presses against two circumferentially spaced points on the inner surface of the socket of the tool bit 100. Thereby, when the wedge 30 moves to the lock position, each wedge 30 can be brought into close contact with the convex surface of the inner periphery of the socket at two points separated in the circumferential direction, and the coupling force with the tool bit 100 is increased.
Next, with reference to FIGS. 3A and 3B, an operation of selectively switching the wedge 30 between the attaching / detaching position and the locking position by the locking mechanism will be described. When attaching the tool bit 100 to the impact tool 1, the plug 22 is inserted into the socket of the tool bit 100. At this time, as shown in FIG. 3 (a), the wedge 30 is held at the attachment / detachment position on the distal end side of the plug 22, and a slight gap is left between the wedge 30 and the inner peripheral surface of the socket. The bit 100 can be easily attached to and detached from the plug 22. Before starting the impact tool 1, as shown in FIG. 3B, the operation handle 40 is rotated, and the wedge 30 is slid along the axial direction to the rear end side of the output shaft 21 to be in the locked position. Move. In this locked position, the wedge 30 is pressed against the inner peripheral surface of the socket, and rattling of the wedge 30 in the socket is eliminated, and the rotational impact is effectively transmitted to the tool bit 100.
As described above, since the wedge 30 arranged on the outer periphery of the plug 22 moves along the axial direction of the output shaft between the attachment / detachment position and the lock position, the tool bit can be easily attached / detached at the attachment / detachment position. Then, by the wedge coupling, the tool bit 100 can be firmly coupled to the output shaft 21 in a relatively non-rotatable manner, and the rotational impact can be reliably transmitted to the tool bit 100. In this connection, as shown in FIG. 4, protrusions 34 that contact the convex surface of the inner periphery of the socket at two points in the circumferential direction may be formed on the outer peripheral surface of the plug 22 where the wedge 30 is not disposed.
In the present embodiment, one set of opposed outer peripheral surfaces among the four outer peripheral surfaces are inclined surfaces, but the present invention is not limited to this form, and all the outer peripheral surfaces are inclined surfaces. A wedge 30 may be disposed on each inclined surface.

緩み止め機構の操作ハンドル４０について、出力軸２１の外周にネジ結合で配置される場合を述べたが、図５に示すように、ばねを介して出力軸に結合され、このばねがくさびを着脱位置からロック位置へ移動させる方向へのばね力を操作ハンドルに与えてもよい。以下、緩み止め機構についての種々の変更態様を示す。
図６（ａ）（ｂ）に示す変更態様では、着脱位置とロック位置との間でのくさび３０の軸方向への移動をガイドするためのレール２５をプラグ２２の外周面に形成している。このレール２５は軸方向に沿って形成され、くさび３０の内接触面３１に形成した凹部３５へスライド自在に係合する。
図７示す変更態様での緩み止め機構では、プラグ２２の外周の４つのエッジのうち、少なくとも１つのエッジに、くさび３０を配置している。くさび３０は矩形断面を有し、プラグ２２のエッジを切り欠いて形成した凹所に収められる。この凹所は、互いに直交する２つの面で形成され、少なくとも一つの面がプラグ先端側に向けて下がる傾斜面とされ、この傾斜面にくさび３０が誘導されて、着脱位置とロック位置との間でくさびが軸方向に沿って移動する。くさび３０の後端には、リング形状の操作ハンドル４０の内周に結合するフランジが形成され、出力軸２１の外周へねじ結合される操作ハンドル４０の回転が、着脱位置とロック位置との間のくさびの軸方向移動に変換される。この変更態様では、くさび３０がソケットの隅へエッジ結合することができて、出力軸２１と工具ビット１００との間のがたつきを無くし、回転インパクトを効果的に工具ビット１００へ伝えることができる。
図８に示す変更態様での緩み止め機構は、２つの直交する辺と斜辺とで規定される三角形断面を有するくさび３０を、プラグ２２のエッジに配置している。プラグ２２のエッジは面取り面となり、この面取り面がプラグ２２の先端に向けて下り傾斜する傾斜面となり、くさび３０がその斜辺をこの傾斜面に沿って上にスライドすることで着脱位置とロック位置との間で移動する。ロック位置では、くさび３０の斜辺以外の２つの直交する辺がソケットの隅に密接して、工具ビット１００を強固に出力軸へ保持する。
図９に示す変更態様での緩み止め機構では、Ｌ字形断面のくさび３０をプラグ２２のエッジに配置している。プラグ２２の各エッジには、Ｌ字を構成するくさび３０の横片と縦片をそれぞれ収める横溝と縦溝が形成され、横溝と縦溝のそれぞれが軸方向に沿って下り傾斜する面を有し、くさびがこの傾斜面に沿って、着脱位置とロック位置との間で移動する。ロック位置では、くさびの横片と縦片とが共に、ソケットの隅に密接して工具ビットを出力軸へ強固に保持する。 Although the operation handle 40 of the locking mechanism has been described as being screwed on the outer periphery of the output shaft 21, it is connected to the output shaft via a spring as shown in FIG. A spring force in a direction of moving from the position to the lock position may be applied to the operation handle. Hereinafter, various modifications of the locking mechanism will be described.
6 (a) and 6 (b), rails 25 for guiding the movement of the wedge 30 in the axial direction between the attachment / detachment position and the lock position are formed on the outer peripheral surface of the plug 22. . The rail 25 is formed along the axial direction, and is slidably engaged with a recess 35 formed in the inner contact surface 31 of the wedge 30.
In the loosening prevention mechanism in the modified mode shown in FIG. 7, the wedge 30 is arranged on at least one of the four edges on the outer periphery of the plug 22. The wedge 30 has a rectangular cross section and is received in a recess formed by cutting out the edge of the plug 22. The recess is formed by two surfaces orthogonal to each other, and at least one surface is an inclined surface that is lowered toward the plug tip side, and the wedge 30 is guided to the inclined surface, so that the attachment / detachment position and the lock position are In between, the wedge moves along the axial direction. At the rear end of the wedge 30, a flange is formed that is coupled to the inner periphery of the ring-shaped operation handle 40, and the rotation of the operation handle 40 that is screwed to the outer periphery of the output shaft 21 is between the attachment / detachment position and the lock position. Converted to axial movement of the wedge. In this modification, the wedge 30 can be edge-coupled to the corner of the socket, eliminating rattling between the output shaft 21 and the tool bit 100, and effectively transmitting the rotational impact to the tool bit 100. it can.
In the locking mechanism in the modified mode shown in FIG. 8, a wedge 30 having a triangular cross section defined by two orthogonal sides and a hypotenuse is arranged at the edge of the plug 22. The edge of the plug 22 becomes a chamfered surface, and this chamfered surface becomes an inclined surface inclined downward toward the tip of the plug 22, and the wedge 30 slides its oblique side upward along the inclined surface so that the attaching / detaching position and the locking position are achieved. Move between. In the locked position, the two orthogonal sides other than the hypotenuse of the wedge 30 are in close contact with the corners of the socket, firmly holding the tool bit 100 to the output shaft.
In the loosening prevention mechanism in the modified mode shown in FIG. 9, the wedge 30 having an L-shaped cross section is arranged at the edge of the plug 22. Each edge of the plug 22 is formed with a horizontal groove and a vertical groove that respectively accommodate the horizontal piece and the vertical piece of the wedge 30 constituting the L-shape, and each of the horizontal groove and the vertical groove has a surface inclined downward along the axial direction. The wedge moves along the inclined surface between the attaching / detaching position and the locking position. In the locked position, both the lateral and longitudinal pieces of the wedge are in close contact with the corners of the socket and hold the tool bit firmly to the output shaft.

１インパクト工具
２ハウジング
２１出力軸
２２プラグ
３０くさび
３４突起
４０操作ハンドル 1 Impact Tool 2 Housing 21 Output Shaft 22 Plug 30 Wedge 34 Projection 40 Operation Handle

Claims

An impact tool that gives a rotational impact to a tool bit having a socket at its end, and a housing having an output shaft that is driven to rotate about the shaft;
An impact mechanism for imparting a rotational impact to the output shaft;
With a locking mechanism,
The output shaft has a plug at one end in the axial direction, and the plug is detachably fitted into the socket of the tool bit to transmit the rotational motion to the tool bit.
The locking mechanism is
At least one wedge movable along the axial direction of the plug on the peripheral surface of the plug;
It consists of an operation handle arranged on the outer periphery of the output shaft,
The operating handle is coupled to the wedge and is configured to move the wedge between the attach / detach position and the locking position;
In the attachment / detachment position, a clearance remains between the wedge and the inner peripheral surface of the socket, and the plug is allowed to rotate slightly relative to the tool bit within the clearance within the clearance of the plug.
In the locked position, an impact tool in which the wedge is tightly sandwiched between the outer peripheral surface of the plug and the inner peripheral surface of the socket so that the relative rotation of the plug with respect to the socket is not allowed.

The operation handle is disposed on the outer periphery of the output shaft, coupled to the wedge, and rotated relative to the output shaft to move the wedge axially relative to the plug between the attachment / detachment position and the locking position. 2. The wedge according to claim 1, wherein the wedge leaves a gap between the inner peripheral surface of the socket at the attachment / detachment position, and the wedge comes into close contact with the inner peripheral surface of the socket and the outer peripheral surface of the plug at the lock position. Impact tool.

The plug has a rectangular cross section, and is fitted into the socket having a corresponding cross section, and the plug is tapered and has an inclined surface on the outer periphery thereof.
The impact tool according to claim 1, wherein the wedge is disposed on an inclined surface of the plug and is slidable along an axial direction of the output shaft.

The wedge has a U-shaped cross section composed of a base and protrusions protruding from both ends thereof,
The base is supported by the inclined surface of the plug, and when the wedge is in the locked position, the protrusions are pressed against two circumferentially spaced points on the inner surface of the socket, respectively. The listed impact tool.

The impact tool according to any one of claims 1 to 4, wherein the plug has a rectangular cross section, two outer peripheral surfaces facing each other in a radial direction are inclined surfaces, and the wedge is disposed on each inclined surface.

The operation handle is disposed on the outer periphery of the output shaft, is coupled to the wedge, and is slidable along the axial direction of the output shaft together with the wedge, and is spring-biased in the direction of moving the wedge from the attachment / detachment position to the lock position. The impact tool according to any one of claims 1 to 5.

The plug has a rail extending in the axial direction along the inclined surface,
The impact tool according to any one of claims 1 to 5, wherein a concave groove into which the rail is slidably fitted is formed in the wedge.

The wedge is
The impact tool according to any one of claims 1 to 5, wherein the impact tool is formed at at least one place on an edge of an outer peripheral surface of the plug.

The impact tool according to any one of claims 1 to 3, wherein the wedge is disposed on at least one of a plurality of edges existing on an outer peripheral surface of the plug.