JPS6084770U - Internal combustion engine ignition timing control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Brief explanation of drawings]

Fig. 1 is a sectional view of the conventional example, Fig. 2 is a sectional view of the first embodiment of this invention, Fig. 3 A and B are comparative characteristics of ignition timing,
4 and 5 are sectional views of the second and third embodiments of this invention, respectively, and FIGS. 6A and 6B are comparative characteristic diagrams of the operating range of the second throttle valve. 10... Combustion chamber, 5... Intake valve, 4.
...Main intake passage, 7...Carburetor throttle valve,
8...Second throttle valve, 9...Sub-intake passage, 13...Ignition device distributor,
14...Vacuum advance angle device, 15...Negative pressure outlet passage, 16...Throttle switch, 18
...Three-way solenoid valve.

Claims (1)

[Scope of utility model registration request] The main intake passage that communicates the intake valve with the combustion chamber is provided with an intake throttle valve and a second throttle valve that closes in a low load range downstream of the intake throttle valve. In an internal combustion engine, an internal combustion engine is provided with a sub-intake passage that guides intake air so as to generate a vortex flow, and is equipped with a vacuum advance device that advances the ignition timing in response to the intake pipe negative pressure taken out from between the throttle valves. means for detecting the opening degree of the second throttle valve; and in response to a signal from the detection means, atmospheric air is introduced into the negative pressure outlet passage of the vacuum advance device when the opening degree exceeds the set opening degree. 1. An ignition timing control device for an internal combustion engine, comprising means for forcibly retarding ignition timing.