| 摘要 |
<p>A reducing agent supply apparatus that can reduce the state of large deviation of the pressure within a reducing agent supply passage from a target pressure and an exhaust gas purification apparatus including such a reducing agent supply apparatus are provided. A reducing agent supply apparatus including a pump, a reducing agent injection valve, a reducing agent supply passage, a reducing agent return passage and a pressure sensor, in which injection control of the liquid reducing agent by the reducing agent injection valve is performed while the reducing agent pressure is controlled so as to be maintained at a predetermined target pressure, includes: a passage throttle valve provided on the reducing agent return passage and having an opening controlled by energization; a pump control means for feedback-controlling the output of the pump based on the difference between the reducing agent pressure and the target pressure; and a passage throttle valve control means for controlling the opening of the passage throttle valve according to the change in the operation amount of the reducing agent injection valve.</p> |
