15  EP 3 800 011 A1 16  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 at leasttwothrottle portionsconfigured to graduallychange areas of flow channels in which air movementofthe valve member,to controla flow amount of the air in the pipe line, and change amounts of the areas of the flow channels of the throttle portions with respect to a movement amount of the valve member are different from each other. 5 10 change of the clearance amount at the throttle portion and the change of the opening amount of the opening portion.Accordingto the structure,the flow channelarea can be stepwisely adjusted by the flow amount adjust- ment at two places. Therefore, even when the pressure difference between infrontofand behind the throttle por- tion becomes small by operating the operation portion to a certain extent and the pressure to jet out the air de- creases, the decrease in the pressure can be compen- sated by the increase in the flow channel area, so that the relationship between the operation amountoftheop- eration portion and the amount of air jetted out of the nozzle can be made close to a proportional relationship. 15 [0060] According to an aspect of the invention, there is also provided a driving tool comprising the air duster structure, the driving tool configured to eject a fastener by using the compressed air. 20 [0061] According to an aspect of the invention, there isalso provided a driving toolwhich includesanairduster structure that is configured to jet compressed air out of a nozzle, and which is configured to eject a fastener by using the compressed air,the driving toolcomprising:an operation portion; a pipe line for circulating air; and a valve member which is configured to move in the pipe line with an operation to the operation portion, wherein, when the operation portion is operated, the compressed air is jetted out of the nozzle, and, when the operation portion is operated, the valve member moves in the pipe line, and an area of a flow channel in which air circulates is changed with the movement of the valve member so that a flow amount of the air in the pipe line is adjusted. [0056] In the above described structure, at least two throttle portions are provided where the flowchannelarea change amounts with respect to the movement amount of the valve member can be made different from each other. According to the structure, the flow channel area can be stepwisely adjusted by the flow amount adjust- ment at two places. Therefore, even when the pressure differencebetweenin frontofand behind the throttlepor- tion becomes small by operating the operation portion to a certain extent and the pressure to jet out the air de- creases, the decrease in the pressure can be compen- sated by the increase in the flow channel area, so that the relationship between the operation amountofthe op- eration portion and the amount of air jetted out of the nozzle can be made close to a proportional relationship. 25 30 [0057] The throttle portion may be configured to grad- ually change an amount of clearance between the pipe line and the valve member when the valve mem moves, to control the flow amount of the air in the pipe line. In this case, the flow channel area can be changed by the change of the clearance amount. 35 [0058] 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 graduallychange an amount ofclearance betweenthe pipe line and thevalvemember when the valve member moves, an opening portion that is open in a direction orthogonal to a direction in which the valve member moves is provided on one of the pipe line or the valve member, a blocking portion capable of adjusting an opening amount of the opening portion is provided on the otherofthe pipeline orthevalve member, and the flow amount adjustment mechanism is config- ured to control a flow amount of the air in the pipe line by a change of the clearance amount at the throttle por- tion and a change of the opening amount of the opening portion. 40 45 50 55 [0059] In the above described structure, the flow amount of the air in the pipe line is controlled by t he a tool body (11) having a striking mechanism inside; a grip (12) protruding from the tool body 11 in an orthogonal direction; a nose portion (14)protrudingon a tipofthe tool body(11),the nose portion (14)having an eject- ing hole (14a) from which a fastener is ejected; an operation portion (30) disposed in a position such that it can be depressed with a finger of a user’s hand grasping the grip (12); a valve member(31)provided withthe operation portion (30),wherein the valve member isstruc- tured so as to slide along with the depression of the operation portion (30); and an air outlet (40) which is configured to release air to an outside of a housing of the tool body (11), wherein the nozzle (17b) is open in the neigh- Claims 1. A driving tool(10)which includes an airdusterstruc- ture that is configured to jet air out of a nozzle (17b) by using externally supplied compressed air, the driving tool (10) comprising: 9