PRESSURE WRITING TOOL

To provide a pressure writing tool, in which a sealed state of a back space of an ink storage cylinder is cancelled to easily make it the same pressure as the external pressure under a situation where a writing tip projects from a front end opening of a shaft cylinder, and pressure may be applied thereto under a situation where the writing tip projects from the front end opening of the shaft cylinder.SOLUTION: A ball pen refill 7 comprising a an ink storage cylinder 11 filled with an ink composition 12 for a writing tool and a ballpoint pen tip 14 is accommodated in a shaft cylinder 4. A pressurizing mechanism 6 connected to a back part of the ink storage cylinder 11 and a slider engaged with the shaft cylinder 4 in a manner movable back and forth are provided behind the ink storage cylinder 11. The pressurizing mechanism 6 comprises a cylinder 17 having an air port 17c behind the ballpoint pen refill 7, which communicates inside and outside; a piston 18 arranged in a manner movable back and forth relatively to the cylinder 17; and a pressurizing space 10 accommodated in the cylinder 17, which communicates a back space 7c of the ballpoint pen refill 7 with the piston 18.SELECTED DRAWING: Figure 1 【課題】筆記先端部を軸筒の前端開口部から突出させた状態で、インキ収容筒の後方空間部の密閉状態を解除して容易に外気圧と同圧とし、且つ、筆記先端部を軸筒の前端開口部から突出させた状態で、加圧可能な加圧式筆記具を提供すること【解決手段】軸筒４内に、筆記具用インキ組成物１２を充填したインキ収容筒１１と、ボールペンチップ１４と、を具備したボールペンレフィル７を収容し、インキ収容筒１１の後方には、インキ収容筒１１の後部に連結した加圧機構６と、軸筒４に対して前後動自在に係止した摺動体と、を具備し、加圧機構６が、ボールペンレフィル７の後方に内外を連通する空気口１７ｃを有するシリンダー１７と、シリンダー１７に対し前後動可能に配設したピストン１８と、シリンダー１７の内部にボールペンレフィル７の後方空間部７ｃとピストン１８との間を連通する加圧空間部１０と、を備える。【選択図】図１