pressure canceling chamber and a second valve allowing or cutting the supply of hydraulic pressure into the second hydraulic pressure chamber and the first hydraulic pressure canceling chamber application_number US 201515304832 A description hereinafter a dual clutch device according to an embodiment of the invention will be described based on the accompanying drawings like reference numerals are given to like component parts and this will also be true with names and functions consequently the detailed description of those constituent components will not be repeated in the description as shown in fig1 a dual clutch device 10 includes a first wet type clutch c 1 and a second wet type clutch c 2 reference numeral 11 denotes a clutch input shaft into which power of an engine e is transmitted reference numeral 12 a denotes a first transmission input shaft on which a speed change gear train which establishes for example odd numbered gears of a transmission t is provided and reference numeral 12 b denotes a second transmission input shaft on which a speed change gear train which establishes for example even numbered gears is provided the second input shaft 12 b is supported rotatably via bearings 13 within a hollow shaft of the first input shaft 12 a the first wet type clutch c 1 includes a clutch hub 20 which rotates together with the clutch input shaft 11 a plurality of first inner plates 21 a which are spline fitted in the clutch hub 20 a first clutch drum 22 which rotates together with the first.