USA Zama, Inc.

Zama Japan

Oki Electric Industry Co., Ltd.

Zama Japan Kabushiki Kaisha

Z Ama Japan Co., Ltd.

Shinagawa Diecast Industrial Corp.

Satoru Araki

Kimio Koizumi

Yasuaki Kohira

Mamoru Toda

A carburetor having a choke valve has an open-close valve sliding reciprocatingly inside a valve hole partway along a bypass air passage. The open-close valve, pressed by urging member, slides according to a rotation angle of a choke valve shaft while a distal end side continuously contacts a side face of the shaft. A projecting part, urged by a coil spring, projects from a distal end of a body. The urging member includes a temperature-sensitive material that expands at or above a prescribed temperature. When the choke valve is closed and the ambient temperature is less than the prescribed temperature, the bypass air passage enters a closed state while the body remains in a closed-valve position; and when the ambient temperature is at or above the prescribed temperature, the urging member elongates and the body enters an open-valve position, and the bypass air passage enters an open state.

Carburetor

An interlocking lever having first and second cam faces is mounted on a throttle valve stem, and a throttle valve is arbitrarily opened to perform start-up in a state in which the first cam face makes contact with the choke valve lever and the interlocking lever is stopped during low-temperature start-up with the choke valve closed. After the choke valve has been returned to the fully open position, the throttle valve alone is opened with a small degree of opening to perform low-load operation; and in the mid- and high-load region, the interlocking lever integrally turns with the throttle valve, the second cam face pushes the air valve lever, and the throttle valve and air valve are caused to open and close proportionally. Preferably, the degree of opening of the throttle valve for low load operation is adjustable.

Carburetor for two-cycle engine

The carburetor prevents an air-fuel mixture from becoming excessively lean and prevents a fuel pressure from becoming unstable, thereby making it possible to stably supply a fuel to an engine, in a diaphragm-type carburetor with a pressure regulator. A diaphragm-type carburetor includes a fuel pump using a pulsation pressure generated in a crank chamber of an engine or an intake pipe as a driving force, and a metering chamber having a diaphragm and a lever mechanism and provided with fuel at a desired constant pressure. The diaphragm-type carburetor includes a bubble discharge path connecting the metering chamber to other predetermined discharge portions and with a check valve in each of an inlet side and an outlet side. A bubble removing pump is connected to the bubble discharge path, withdraws the bubble to the bubble discharge path from the metering chamber in conjunction with a closing or opening operation of a throttle shaft by a driver or operator and discharging the withdrawn bubble to the discharge portion in conjunction with an opening or closing operation of the throttle shaft.

Diaphragm-type carburetors

The present invention provides a carburetor that can be adapted to a variety of engines with different positional relationships between the location for feeding the air/fuel mixture and the location for feeding scavenging air. The carburetor a carburetor main body () with an air intake passage () forming a portion of the air/fuel mixture passage () and is provided with an air passage () that forms a portion of an air channel () for scavenging air. The air passage () is positioned parallel to an air intake passage (), and the front end thereof is positioned further to the base end side than to the engine-side front end face of the carburetor main body (), enhancing the degree of freedom for placing the conduit pipe () for connecting the air passage () to the scavenging air feed port (. Also, the throttle valve () and the air valve () are butterfly valves with mutually parallel valve stems, and the interlocking mechanism thereof has a simple configuration.

Carburetor for two-stroke engine

An interface circuit includes a frequency divider which divides a frequency of a base clock to provide frequency-divided clock signals; a first address register which stores an address signal at a timing in which the frequency-divided clock signal is turned to high; a second address register which stores the address signal at a timing in which the clock signal is turned to low; a first data register which stores a data signal at a timing in which the clock signal is turned to high; and a second data register which stores the data signal at a timing in which the clock signal is turned to low. The data signals stored in the first and second data registers are selectively outputted.

Interface circuit for selectively latching between different sets of address and data registers based on the transitions of a frequency-divided clock

An accelerator for a carburetor that is linked to a throttle valve and allows a piston-type accelerator pump to be operated in a simple configuration that dispenses with a link mechanism and does not greatly enlarge the carburetor. The lower surface of a throttle valve lever () is provided with a cam () that has a circular shape centered about a throttle valve stem () and is configured such that the cam surface (A) thereof faces a carburetor main body (). An accelerator pump () is placed parallel to the throttle valve stem () and the upper end of a piston rod () thereof is brought into contact with the cam surface (A). The cam () pushes the piston rod () down as the throttle valve lever () swings in the opening direction of the throttle valve, and the acceleration fuel in the pump chamber () is delivered and supplied to the suction channel ().

Acceleration apparatus for carburetor

An interlocking lever having first and second cam faces is mounted on a throttle valve stem, and a throttle valve is arbitrarily opened to perform start-up in a state in which the first cam face makes contact with the choke valve lever and the interlocking lever is stopped during low-temperature start-up with the choke valve closed. After the choke valve has been returned to the fully open position, the throttle valve alone is opened with a small degree of opening to perform low-load operation; and in the mid- and high-load region, the interlocking lever integrally turns with the throttle valve, the second cam face pushes the air valve lever, and the throttle valve and air valve are caused to open and close proportionally.

A delay apparatus delays a rising edge and a falling edge of a digital signal. The delay apparatus includes a first edge detection circuit which detects a first edge or rising edge of the digital signal and generates a detection signal; a set circuit that includes a first counter for generating a count value and clearing the count value in response to the detection signal, wherein the set circuit generates a set signal if the count value reaches the number of the reference clock signals corresponding to the delay period of time; a reset circuit which generates a reset signal if an elapsed period of time since a generation of the set signal equals a period of time the digital signal maintains the second logic level; and an output circuit that outputs a delayed digital signal including edges synchronized with the set signal and the reset signal.

Delay apparatus and method

A valve opening mechanism for a rotary throttle valve type carburetor having a lever which transmits the accelerator operation to the throttle valve. The lever and throttle valve are turned while the throttle valve is simultaneously caused to move in the central axial direction from the idle position by a cam part. This movement slightly increases the degree of overlap between a throttle orifice in the throttle valve and an air intake passage in the carburetor body, and slightly reduces the depth of insertion of a metering needle into the fuel nozzle. As a result, the amount of air and fuel is increased to an amount necessary for low-temperature starting. In operation, the cam part engages with the lever and is fixed in the operative position. Then, the lever is released by the normal operation of the accelerator, and is returned to the inoperative position by a return spring.

Rotary throttle valve type carburetor

In a first aspect, a carburetor fuel adjusting device that facilitates control of the quantity of fuel that flows from the fuel chamber to an air intake port of a carburetor by making it possible for the user to adjust an adjustment valve within the limits defined by emission control regulations. The carburetor fuel adjusting device has a cap having two appendages, and an engagement area to engage a valve extension of the fuel adjustment valves of a carburetor. The cap is retained by the retainer in either a disengaged position, or an engaged position wherein the engagement area of the cap becomes attached to the valve extensions. In the engaged position, the adjustment valves can be turned in unison with the cap within a range formed by the angle between the appendages which, when rotated, abut against stoppers. In a second aspect, a retaining plate of elastic material having two retainer holes adapted to receive and retain the pair of adjustment valves in a prescribed adjustment position is laid against an outer surface of the carburetor body. The adjustment valves each have a base-end portion and a small diameter portion, the threads of the base-end portion having an external diameter larger than that of the threads of the small diameter portion. The external diameter of the threads of the base-end portion is also larger than the diameter of each of the retainer holes of the retaining plate such that when the adjustment valve is screwed into the screw hole of the carburetor, the base-end portion cuts threads in the retainer holes of the retaining plate to thereby prevent rotation of the adjustment valve.

Carburetor fuel adjusting device

A carburetor fuel adjusting device that facilitates control of the quantity of fuel that flows from the fuel chamber to an air intake port of a carburetor by making it possible for the user to adjust an adjustment valve within the limits defined by emission control regulations. The carburetor fuel adjusting device has a cap having two appendages to limit its turning in the lean mixture direction and in the rich mixture direction, and an engagement area to engage a valve extension of the fuel adjustment valves of a carburetor. The valve extensions are inserted through insertion holes of a retainer attached to the carburetor body. When the cap is retained by the retainer in a disengaged position, wherein the engagement area is not attached to the valve extensions of the fuel adjustment valves, the adjustment valves can be adjusted separately from the cap. The cap, however, can be moved forward to an engaged position wherein the engagement area of the cap becomes attached to the valve extensions. In the engaged position, the adjustment valves can be turned in unison with the cap within a range formed by the angle between the appendages which, when rotated, abut against stoppers.

Growing community of inventors

Kanagawa, Japan

Satoru Araki