PROBLEM TO BE SOLVED: To enlarge the diameter of a passage, through which a suction object passes, inside a cylinder conduit, and also to suppress sliding resistance between a plunger and the cylinder conduit.SOLUTION: A valve guide member (a cylinder) 24 includes: a straight conduit 41 and a valve reception part 42 having a first truncated conduit 47. A plunger 25 includes: a body shaft part 51 with a diameter smaller than that of the straight conduit 41 a first truncated valve part 52 arranged at the distal end of the body shaft part 51 and a second truncated valve part 53 arranged at the rear end of the body shaft part 51. When the head 54 of the plunger 25 is not operated by pressurization, the second truncated valve part 53 is made to abut on the inner wall of the first truncated conduit 47, to block communication between a suction passage 17 and a negative pressure source passage 21. On the contrary, when the head 54 is operated by pressurization, the first truncated valve part 52 is made to abut on a cylinder opening 35 and also the abutment between the second truncated valve part 53 and the first truncated conduit 47 is released, to obtain communication between the suction passage 17 and the negative pressure source passage 21.COPYRIGHT: (C)2012,JPO&INPIT【課題】シリンダの管路内において吸引物が通る通路の径を広くするとともに、プランジャとシリンダの管路との摺動抵抗を抑える。【解決手段】弁ガイド部材(シリンダ)24に、直管管路41と、第1錐形管路47を有する弁受け部42とを設ける。プランジャ25を、直管管路41よりも細径の本体軸部51、本体軸部51の先端部に設けられた第1錐形弁部52と、本体軸部51の後端部に設けられた第2錐形弁部53とで構成する。プランジャ25の頭部54が押圧操作されていないときは、第2錐形弁部53を第1錐形管路47の内壁に当接させて、吸引通路17と負圧源通路21との連通を遮断する。逆に頭部54が押圧操作されたときは、第1錐形弁部52をシリンダ開口35に当接させるとともに、第2錐形弁部53と第1錐形管路47との当接を解除させることにより吸引通路17と負圧源通路21とを連通させる。【選択図】図2
