1 EP 3 800 011 A1 2  Description BACKGROUND [0007] BRIEF DESCRIPTION OF THE DRAWINGS SUMMARY [0001] The present invention relates to an air duster structure that jets air from a nozzle by using externally supplied compressed air and to a driving tool provided with the air duster structure. in the pipe line, and the throttle portion is structured so as to increase the area of the flow channel at an accel- erated rate when the valve member moves in a direction that opens the pipe line. 5 10 [0002] An air duster gun or an air duster included with a driving toolhas been used in orderto blow offfine wood debris and the like before performing nail driving. For example, JP-A-H10-109280 discloses a driving tool in- cluding an airduster.The related-arttechnique disclosed in JP-A-H10-109280 is structured so that air is jetted out of a nozzle by pushing in an operation button that opens and closes a release valve. 15 FIG. 1 is a right side view of a driving tool provided with an air duster structure. FIG. 2 is a left side view of the driving tool provided with the air duster structure. FIG. 3 is an A-A cross-sectional view of the driving tool. FIG.4 isa leftside view ofthedriving toolfromwhich a tip cover member and a side cover member are detached. FIG.5A isa perspectiveview ofthe tip covermember viewed from the reverse side, and FIG. 5B is a per- spective view of the tip cover member viewed from the obverse side. FIG.6 isa perspective viewofthe driving toolviewed from below. FIG. 7 is a cross-sectional view of a flow amount adjustment mechanism according to a first embodi- ment, and a view of a condition where an operation portion is not operated. FIG. 8 is a cross-sectional view of the flow amount adjustmentmechanismaccording tothe firstembod- iment,and a view ofa condition where the operation portion is depressed all the way in. FIG. 10 is a graph showing a relationship between the operation amount, and the flow amount and the flow channelarea according to the firstembodiment. FIGS. 9A to 9D are views explaining the operation ofthe flow amountadjustmentmechanismaccording to the first embodiment,FIG.9A isa view ofthe con- dition where the operation portion is not operated, FIG. 9B is a view of a condition where the operation portion is operated approximately 1/3 the way, FIG. 9C is a view of a condition where the operation por- tion isoperated approximately 2/3 the way,and FIG. 9D is a view of a condition where the operation por- tion is fully operated. FIG. 11 is a cross-sectional view of a flow amount adjustment mechanism according to a second em- bodiment, and a view of a condition where the oper- ation portion is not operated. FIG. 12 is a cross-sectional view of the flow amount adjustmentmechanismaccordingto the second em- bodiment, and a view of a condition where the oper- ation portion is depressed all the way in. FIGS.13A to 13E are views explainingthe operation ofthe flow amountadjustmentmechanismaccording to the second embodiment,FIG.13A isa view ofthe condition where the operation portion is not operat- ed, FIG. 13B is a view of a condition where the op- [0005] Accordingly, an object of the present invention is to provide an air duster structure and a driving tool where the adjustment of the flow amount of the air being jetted out is easy. [0006] According to an aspect of the invention, there is provided an air duster structure that is configured to jetcompressed airoutofa nozzle,the airdusterstructure comprising:a flow amountadjustmentmechanismwhich is configured to adjust an amount of air jetted out of the nozzle, wherein the flow amountadjustmentmechanism includes: a pipe line for circulating air; a valve member disposed inside the pipe line and being movable; and a throttle portion configured to gradually change an area ofa flow channelin which aircirculates,with a movement of the valve member, to control a flow amount of the air 55 50 45 40 [0004] However,in actuality,as the flow amountofthe air being jetted out increases, the pressure in the accu- mulator provided on the upstream side of the release valve decreases and the difference in the pressure be- tween in front of and behind the throttle of the release valve becomes small, so that the change in the flo amount with respect to the change in the operati amountbecomes small.Thisproduces aninconvenience in that after the operation button is operated to a certain extent, even if the operation button is operated any fur- ther, the amount of air jetted out of the nozzle does not largely change and this deteriorates operability. 35 on 30 25 [0003] To adjustthe amountofairjetted outofthenoz- zle according to the operation amount of the operation button in an air duster as described above, it is consid- ered to form the release valve or a pipe line in a tapered shape to increase the area of the flow channel of the air accordingto the pushing amountofthe operationbutton. At this time, if the flow amount gradually increases while the pushing amount of the operation button and the flow amount of the air maintain a proportional relationship therebetween, and the flow amount of the air is largest when the operation amount is highest, operability is ex- cellent. 20 2