US 5,626,118 A · Piston valve type carburetor

Abstract

The position located above the upper surface of fuel in a float chamber is communicated with the position where the sectional area of a suction passage varies or the position in the vicinity of the foregoing position via a negative pressure introduction passage. The intermediate part of the negative pressure passage is opened or closed by a solenoid valve adapted to be controlled by electronic controlling means. An opening/closing rate of a solenoid valve is determined by inputting informations from a temperature sensor sensing the atmospheric temperature as well as a pressure sensor sensing the atmospheric pressure into the electronic controlling means. The float chamber is normally communicated with the atmosphere via an atmosphere passage. As an altitude becomes high more and more, the valve opening time for the negative pressure introduction passage is elongated and the differential pressure between the float chamber and the suction passage is reduced, causing a quantity of ejected fuel to be reduced. In addition, as the atmospheric temperature becomes high more and more, the valve opening time for the negative pressure introduction passage is elongated and the differential pressure between the float chamber and the suction chamber is reduced, and a quantity of ejected fuel is reduced so that the air fuel ratio is corrected by adjusting a quantity of fuel to be ejected.

Claims14

Dependent claims

A piston valve type carburetor including a float chamber having fuel stored therein, a piston valve adapted to be directly actuated to variably change a sectional area of a suction passage, and a jet needle secured to said piston valve to adjust a quantity of fuel to be ejected from a float chamber to said suction passage, comprising;

an atmospheric passage by way of which said float chamber is normally communicated with atmosphere,
a negative pressure introduction passage of which one end is opened at the position of said suction passage or the position in the vicinity of said suction passage of which sectional area is varied by said piston valve and of which other end is opened at the position located above a fuel surface of said float chamber,
opening/closing means for opening or closing the intermediate part of said negative pressure introduction passage,
a temperature sensor for sensing the temperature of atmosphere,
a pressure sensor for sensing the atmospheric pressure, and
electronical controlling means for controlling opening or closing of said opening/closing means in response to informations from said temperature sensor and said pressure sensor.

3 more elements

A piston valve type carburetor including a float chamber having fuel stored therein, a piston valve adapted to be directly actuated to variably change a sectional area of a suction passage, and a jet needle secured to said piston valve to adjust a quantity of fuel to be ejected from said float chamber to said suction passage, comprising;

an atmospheric passage by way of which said float chamber is normally communicated with atmosphere,
opening/closing means for opening or closing the intermediate part of said atmospheric passage,
a negative pressure introduction passage of which one end is opened at the position of said suction passage or the position in the vicinity of said suction passage of which sectional area is varied by said piston valve and of which other end is opened at the position located above a fuel surface of said float chamber,
a temperature sensor for sensing the temperature of atmosphere,
a pressure sensor for sending the atmospheric pressure, and
electronical controlling means for controlling opening or closing of said opening/closing means in response to informations from said temperature sensor and said pressure sensor.

3 more elements

Dependencies are inferred from the claim text.

Piston valve type carburetor

Life of this patent

Piston valve type carburetor

Life of this patent

Abstract

Claims14