| 摘要 |
PROBLEM TO BE SOLVED: To provide an engine choke mechanism capable of providing good startability in a wide temperature range by automatically opening and closing a choke valve at an appropriate timing corresponding to engine temperature. SOLUTION: This choke mechanism is provided with a diaphragm actuator 10 actuating a choke valve 5 from a closed valve position to an open valve position by negative pressure transmitted to a negative pressure chamber 14 via a negative pressure passage 20 from an intake air passage 3. A negative pressure transmission amount control part 25 provided with a first negative pressure passage 26, a second negative pressure passage 27 of which effective section area of a passage is set smaller than that of the first negative pressure passage 26 and in parallel with the first negative pressure passage 26, and a negative pressure passage switching valve 28 constructed to selectively open the first negative pressure passage 26 and the second negative pressure passage 27 and opening the first negative pressure passage 26 when engine temperature detected by a temperature detection part 30 is high and opening the second negative pressure passage 27 when engine temperature detected by a temperature detection part 30 is low, is installed in a middle of the negative pressure passage 20. COPYRIGHT: (C)2005,JPO&NCIPI
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