JPS6354813U - - Google Patents

Description

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of an embodiment of the present invention, Figure 2 is a graph showing the relationship between exhaust gas temperature and catalyst purification performance, and Figure 3 is a graph showing the relationship between exhaust temperature and HC emission amount. . 1...Exhaust manifold, 2...Front pipe, 3
...Catalyst, 5...Pump, 6...Relief valve, 11...Outer pipe, 12...Inner pipe, 13...Space, 14...Outlet port, 15...Inlet port, 31...Air discharge pipe, 3
2...Air introduction pipe, 61, 62...3-way switching valve.

Claims (1)

[Claims for Utility Model Registration] 1. In an exhaust purification device that purifies exhaust gas by installing a catalyst in the exhaust passage of an engine, the exhaust passage on the upstream side of the catalyst is made up of an inner tube and an outer tube, and 2. The outer pipe is connected to the pump via a switching valve, and the switching valve is switched depending on when the engine is cold or warmed up, and when the engine is cold, the outer pipe and inner pipe are An exhaust purification device characterized in that the air in the space between them is discharged by the pump, and the pump supplies air to the space during warm-up. 2 A relief valve is provided in the outer tube, and when the pressure in the space between the outer tube and the inner tube exceeds a predetermined pressure, the air in the space is relieved. The exhaust purification device according to item 1. 3. Utility model registration claim 1, wherein the outer tube and the pump are connected by a circulation passage, and a three-way switching valve is provided in each passage connecting the outlet and inlet of the outer tube and the pump. Or the exhaust purification device according to item 2.