Throttle valve opening controller

A throttle valve opening controller for applying retarding forces against the closing force of the throttle valve when the throttle valve is quickly closed, comprising:

• a diaphragm device consisting of a diaphragm which is movable in association with the throttle valve when the throttle valve opening is smaller than a specified value, a spring for urging said diaphragm against the closing force of the throttle valve with a force smaller than said closing force, and a diaphragm chamber which is formed on the rear side of said diaphragm and to which atmospheric pressure is admitted through a pressure transmitting valve;
• and
• means for varying the leak rate of air discharged from the diaphragm chamber of said diaphragm device when the throttle valve is quickly closed, which is selectively activated depending on the running condition of the engine, wherein said means for varying the leak rate is a bypass path provided therein with an orifice and a temperature sensing on-off valve for opening or closing the bypass path through which atmospheric pressure can be introduced to said diaphragm chamber simultaneously with the introduction of atmospheric pressure through the pressure transmitting valve, said temperature sensing on-off valve comprising a bimetallic element and a valve body, wherein said bimetallic element causes said valve body to close off said bypass path below a specified temperature and causes said valve body to open said bypass path above a specified temperature.

A throttle valve opening controller for applying retarding forces against the closing force of the throttle valve, when the throttle valve is quickly closed, comprising:

• a diaphragm device consisting of a diaphragm which is movable in association with the throttle valve when the throttle valve opening is smaller than a specified value, a spring for urging said diaphragm against the closing force of the throttle valve with a force smaller than said closing force, and a diaphragm chamber which is formed on the rear side of said diaphragm and to which atmospheric pressure is admitted through a pressure transmitting valve;
• and
• means for varying the leak rate of air discharged from the diaphragm chamber of said diaphragm device when the throttle valve is quickly closed, which is selectively activated depending on the running condition of the engine;
• said means for varying the leak rate being a bypass path provided therein with an orifice and an on-off valve for bypassing the pressure transmitting valve for introducing atmospheric pressure to said diaphragm chamber, said bypass path and said pressure transmitting valve both communicating with the atmosphere through a single air port.

A throttle valve opening controller for applying retarding forces against the closing force of the throttle valve when the throttle valve is quickly closed, comprising:

• a diaphragm device consisting of a diaphragm which is movable in association with the throttle valve when the throttle valve opening is smaller than a specified value, a spring for urging said diaphragm against the closing force of the throttle valve with a force smaller than said closing force, and a diaphragm chamber which is formed on the rear side of said diaphragm and to which atmospheric pressure is admitted through a pressure transmitting valve;
• and
• means for varying the leak rate of air discharged from the diaphragm chamber of said diaphragm device when the throttle valve is quickly closed, which is selectively activated depending on the running condition of the engine, wherein said means for varying the leak rate is a bypass path provided therein with an orifice and a temperature sensing on-off valve for bypassing said pressure transmitting valve, said temperature sensing on-off valve comprising a bimetallic element and a valve body, wherein said bimetallic element causes said valve body to close off said bypass path below a specified temperature and causes said valve body to open said bypass path above a specified temperature, and
• wherein said bypass path and said pressure transmitting valve both communicate with the atmospheric through a single air port.