SASH

To improve heat insulation performance by forming a hollow part on the indoor side of a metal frame without affecting the erection of a sash.SOLUTION: A resin cover is provided at a portion on the indoor side of an outer sash when the sashes are closed, out of an inner peripheral recess part of an upper frame for guiding an inner sash. The resin cover includes a resin cover body and a flap member. The resin cover body has an upper wall part covering an upper surface of the inner peripheral recess part of the upper frame, an outdoor side wall part covering an outdoor side surface of the inner peripheral recess part of the upper frame, and an indoor side wall part covering an indoor side surface of the inner peripheral recess part of the upper frame. The flap member is supported on an outdoor side wall part or a lower part of the indoor side wall part of the resin cover body. A heat insulating space is formed by the resin cover body and the flap member.SELECTED DRAWING: Figure 4 【課題】 障子の建て込みに影響を及ぼすことなく金属枠の室内側に中空部の形成して、断熱性能を向上させる。【解決手段】内障子を案内する上枠の内周凹部のうち障子の閉鎖時における外障子の室内側の部分に樹脂カバーが設けられており、樹脂カバーは、樹脂カバー本体とフラップ部材を備え、樹脂カバー本体は、上枠の内周凹部の上面を覆う上壁部と、上枠の内周凹部の室外側面を覆う室外側壁部と、上枠の内周凹部の室内側面を覆う室内側壁部を有し、フラップ部材は、樹脂カバー本体の室外側壁部もしくは室内側壁部の下方部位に支持されており、樹脂カバー本体とフラップ部材とにより断熱空間が形成されている。【選択図】 図４