Patent attributes
A vehicle includes a filter, a negative-pressure mechanism, and a first opening and closing mechanism. The filter is disposed in an exhaust passage coupled to an engine. The negative-pressure mechanism is configured to pressurize a portion of the exhaust passage upstream of the filter to a negative pressure less than an atmospheric pressure. The first opening and closing mechanism includes an opening disposed in the exhaust passage, and a valve configured to selectively open and close the opening. The valve is configured to, when the exhaust passage becomes negatively pressurized by the negative-pressure mechanism, open the opening.