摘要 |
PURPOSE:To obtain the simple constitution at a low cost by installing a choke spring which adjusts the opening degree of a choke valve according to the temperature variation of the engine and is made of high-polymeric material and by adjusting the opening degree of the choke valve by the choke spring only. CONSTITUTION:When the choke shaft 19 of a choke valve 11 is set eccentric by (e) with respect to the center 14a of a choke bore 14, the inhaled air due to the lowering of a piston generates a couple of revolution force, since the pressure receiving area of the choke valve 11 differs with respect to the center. At this time, a reaction force for the couple of revolution force is generated onto a spiral spring 12 for choke which is made of the high polymeric material such as high-polymeric urethane elastomer and whose one edge is fixed onto the choke shaft 19 through a plate 15. Since the modulus of direct elasticity of the spring 12 varies because of the temperature variation, and the springy force varies, the choke valve 11 can be opening/closing-controlled according to the variation of the engine temperature by the spring 12 only. |