试验用单缸风冷化油器式发动机,其上装有吊挂式气门、半球形燃烧室和平顶活塞。对该机的研究表明,发动机气缸盖上火花塞的布置对气缸活塞组的热状况有着明显影响。能得到上述试验结果,是因为有热效应出现。在热效应出现的同时,由发火点点燃可燃混合气并在密闭容器中有火焰传播[1]。 Test single-cylinder air-cooled carburetor-type engine, which is equipped with hanging valve, hemispherical combustion chamber and flat-top piston. Research on this machine shows that the arrangement of spark plugs on the engine cylinder head has a significant effect on the thermal condition of the cylinder piston set. The above test results can be obtained because of the thermal effect. Simultaneously with the onset of the thermal effect, the combustible mixture is ignited by the ignition point and propagated in a closed vessel with flame [1].