RECIPROCATION WORK MACHINE

PROBLEM TO BE SOLVED: To provide a reciprocation work machine of a simple structure capable of changing a stroke quantity of reciprocatably operating a tool support member.SOLUTION: A jigsaw 10 comprises a motion conversion mechanism 96 for reciprocating a plunger 42 in the direction along the axis C1 by torque of a rotary member 26, and comprises an operation control mechanism 58 for switching to the orbital control nonexistence for operating the plunger 42 only in the direction along the axis C1 and the orbital control existence for operating the plunger 42 in an elliptical shape, an electric motor 17 for switching the rotational direction of the rotary member 26 to normal rotation and reverse rotation, and a stroke quantity changing mechanism 88 for making a stroke quantity of reciprocating the plunger 42 different when the rotary member 26 normally rotates and when reversely rotating.SELECTED DRAWING: Figure 1 【課題】工具支持部材が往復動作するストローク量を変えることができ、かつ、構造の簡単な往復動作業機を提供する。【解決手段】回転部材２６の回転力でプランジャ４２を軸線Ｃ１に沿った方向に往復動させる運動変換機構９６を備えたジグソー１０であって、プランジャ４２を、軸線Ｃ１に沿った方向にのみ動作させるオービタル制御無しと、プランジャ４２を楕円形状に動作させるオービタル制御有りと、に切り替える動作制御機構５８と、回転部材２６の回転方向を正回転と逆回転とに切り替える電動モータ１７と、プランジャ４２が往復動するストローク量を、回転部材２６が正回転する場合と逆回転する場合とで異ならせるストローク量変更機構８８と、を有する。【選択図】図１