Abstract: In a vehicle mounting an engine equipped with an exhaust turbocharger and a fluid transmission device as the power transmission device, occurrence of surging in the exhaust turbocharger is prevented at the time of connecting a lockup clutch in the fluid transmission device. When a condition for connecting the lockup clutch is held to lock up the fluid transmission device coupled to the engine 1 equipped with the exhaust turbocharger, the operation is executed by lowering a target engine rotational speed for a predetermined period of time prior to the locking up to avoid the occurrence of surging caused by a decrease in the engine rotational speed due to the lockup. A lockup clutch control device 50 includes first timer means 51 for setting a time for executing the operation by decreasing the target engine rotational speed, and second timer means 52 for setting a time for waiting for the start of lockup.

Abstract: In a vehicle mounting an engine equipped with an exhaust turbocharger and a fluid transmission device as the power transmission device, occurrence of surging in the exhaust turbocharger is prevented at the time of connecting a lockup clutch in the fluid transmission device. When a condition for connecting the lockup clutch is held to lock up the fluid transmission device coupled to the engine 1 equipped with the exhaust turbocharger, the operation is executed by lowering a target engine rotational speed for a predetermined period of time prior to the locking up to avoid the occurrence of surging caused by a decrease in the engine rotational speed due to the lockup. A lockup clutch control device 50 includes first timer means 51 for setting a time for executing the operation by decreasing the target engine rotational speed, and second timer means 52 for setting a time for waiting for the start of lockup.