Exhaust pressure modulation valve

摘要

PCT No. PCT/GB91/02004 Sec. 371 Date May 12, 1993 Sec. 102(e) Date May 12, 1993 PCT Filed Nov. 13, 1991 PCT Pub. No. WO92/08887 PCT Pub. Date May 29, 1992.An exhaust gas pressure modulation valve for a diesel engine vehicle combines the functions of an exhaust brake and a warm-up valve and has a single butterfly valve (12) to close the exhaust passage. The butterfly is reactive and opens automatically at a predetermined back pressure to prevent engine damage. The butterfly includes a small bypass passage or aperture (29) to permit a low throughput of exhaust gas when closed.