Abstract: A reductant supply device having a reductant injection valve with an injection tip that is fixed to an exhaust pipe on the exhaust gas upstream side of a reduction catalyst, the device directly injecting and supplying an urea aqueous solution which is pressure-fed to the reductant injection valve in a state of a liquid fluid, by controlling opening and closing of the reductant injection valve. The device includes a cooling water circulation passage; a flow rate control valve; a temperature sensor for detecting a temperature at the tip of the reductant injection valve; and a controller for controlling the flow rate control valve based on the temperature at the tip such that the temperature at the tip of the reductant injection valve is maintained at a temperature between equal to or higher than a boiling point of the urea aqueous solution and equal to or lower than 130° C.

Abstract: Disclosed is a common rail fuel injection control apparatus that is used in an engine that drives power equipment, an actual measurement temperature difference that is a difference between a pre-pressurization temperature of the fuel and a post-pressurization release temperature of the fuel is obtained, and it is determined that a pressure sensor is failed when an absolute value of a difference between a representative temperature difference set in advance as a difference between the pre-pressurization temperature of the fuel and the post-pressurization release temperature of the fuel, and the actual measurement temperature difference exceeds a predetermined threshold value.