JPS634014B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides gasoline fuel and liquefied petroleum gas (hereinafter referred to as
This invention relates to a carburetor exhaust system in a mixed fuel engine that can selectively use different fuels such as LPG.

Some passenger cars are equipped with engines that use a combination of different fuels, such as using LPG as a regular fuel and using gasoline only when driving when high output is required (application regarding LPG-gasoline combination carburetor). Patent application 1978-8361, practical application 178582, 54-181462, 54-167134, 54-
165598, 54−179190, 54−181460, 55−8892).

Conventionally, a carburetor exhaust system in such a mixed fuel type engine has a structure as shown in FIGS. 1 and 2, for example. Figure 1 shows vaporizer 1
, an LPG nozzle 2 is provided at the upper end to which an air cleaner (not shown) is connected, and its downstream intake passage is arranged in parallel to the primary barrel 3 and secondary barrel 4, each of which is connected to a gasoline fuel nozzle 2. A primary throttle valve 7 and a secondary throttle valve 8 are arranged downstream of the nozzles 5 and 6. LPG gasified by a vaporizer is introduced into the LPG nozzle 2 from an LPG cylinder (not shown) via an LPG passage 9, and is sucked and mixed into the intake air flowing through the nozzle 2. On the other hand, the gasoline fuel in the float chamber 11 is supplied to the main jet 1 through the gasoline nozzles 5 and 6.
2. Gasoline is led through the fuel passage 14 with the main air bleed 13 interposed, and the gasoline is introduced into the nozzles 5 and 6.
Gasoline is sucked in from the nozzles 5, 6 by the intake flow flowing through the bench lilies 15, 16, is atomized and mixed, is metered by the throttle valves 7, 8, and is sucked into the combustion chamber of the engine. . And these
The LPG fuel system and the gasoline fuel system are each equipped with a control device that cuts off fuel supply, etc. In driving areas where fuel economy is prioritized, such as city driving, LPG fuel is primarily supplied, while engine output is reduced. In the required high-speed actual load range, control is performed such as mainly by supplying gasoline fuel. The amount of fuel on the primary side is controlled by the opening/closing control of the primary throttle valve 7 from engine startup to partial load, and when the primary throttle valve 7 opens to a predetermined opening or more, the secondary throttle opens. Valve 8 opens in conjunction with this to supply gasoline fuel from the secondary side as well, thereby increasing output.

The yoke valve 21 is located upstream of the gasoline nozzle 5 on the primary side and is connected to the yoke valve shaft 2.
It is pivoted (fixedly connected) to 2 and can rotate integrally therewith.

A chiyoke device including the chiyoke valve 21 described above will be explained using FIG. 2.

A choke lever 23 is rotatably supported on the outer end of the choke valve shaft 22, and a throttle lever 25 is rotatably supported on the outer end of the throttle shaft 24 of the primary throttle valve 7. These choke lever 23 and throttle lever 25
and are connected to each other by a link 26 so as to be able to interoperate with each other. A brake wire 27 is connected to an end of the brake lever 23 opposite to the brake shaft 22, so that the driver's external force for operating the brake is transmitted to the brake lever 23.

On the other hand, a yoke arm 28 is pivotally attached to the yoke valve shaft 22, and the yoke arm 28 is always connected to the yoke valve 21 by a coil spring wound around the yoke valve shaft 22.
is elastically biased in the valve closing direction of the valve 23.
leaning on one side. Further, the throttle arm 2 is also attached to the throttle shaft 24.
9 is provided, and the throttle arm 29, which is always elastically biased in the closing direction of the throttle valve 7, rests on one side of the throttle lever 25.

Now, from the state where the choke valve is fully open and the throttle valve is fully closed, as shown by the imaginary line in FIG.
3 clockwise around the valve shaft 22 and bring it to the position shown by the solid line.
The yoke arm 28 receives elastic force and rotates clockwise following the rotation of the yoke lever 23.
Fully closed.

On the other hand, in response to the rotation of the throttle lever 23, the throttle valve 7 is slightly opened via the link 26 and the throttle lever 25 by the clockwise rotation of the throttle arm 29 that follows the movement of the throttle lever 25. It is only opened once.

Therefore, when the choke wire 27 is pulled as described above in an attempt to start the engine using gasoline, the choke valve 21 is fully closed and the throttle valve 7 is slightly opened. As a result, when using gasoline fuel, the engine's suction negative pressure acts on the downstream side of the choke valve 21, and the intake air flow passing through the throttle valve 7 is allowed, and the fuel is sucked from the gasoline nozzle 5. The mixture becomes a mixture and is inhaled into the engine. Therefore, the engine can be started easily.

However, when trying to start the engine using LPG fuel, the intake air flow flowing through the LPG nozzle 2 is not sufficient because the choke valve 21 is fully closed, and therefore, the intake air is drawn from the LPG nozzle 2.
The amount of LPG fuel becomes insufficient. For this reason, there was an inconvenience that the engine did not start properly when LPG fuel was used. To avoid such inconvenience, instead of operating the throttle wire 27, by operating an accelerator pedal that can rotate the throttle valve 7 independently of the throttle valve, the throttle valve 7 can be rotated while maintaining the rotation of the throttle valve at the fully open position. It is also possible to open the chisel slightly.
However, it is extremely difficult to maintain the opening degree of the throttle valve 7 at a value suitable for starting using the accelerator pedal, making starting difficult and resulting in an increase in battery consumption.

The present invention was made in view of the inconveniences of the conventional devices and to solve these problems.When trying to start an engine using LPG fuel, the throttle valve opens by a small angle even if the choke wire is pulled, but the choke valve The present invention provides a check valve release mechanism that prevents the valve from closing, and provides a check valve device that facilitates engine starting even when using LPG fuel.

Embodiments of the present invention will be described below with reference to FIGS. 3 and 4. Incidentally, the same elements as those in the above-mentioned conventional example are given the same reference numerals, and the explanation thereof will be omitted.

A second brake arm 31 is pivotally attached to the end of the brake valve shaft 22 opposite to the brake arm 28, and a brake release lever 33 is connected to a brake release wire 32 of another operating tool that transmits the brake release force of the driver's seat. is rotatably supported on the chiyoke valve shaft 22. And the second
The yoke arm 31 rests against the yoke release lever 33 under elastic force in the valve closing direction due to the spring force of a coil spring 34 interposed between the yoke arm 28 and the yoke lever 23. Coil springs 35 and 35b are interposed between the carburetor body, the choke lever 23, and the choke release lever 33, and elastically bias these levers 23, 33 in the opening direction of the choke valve 21.

As a result, in the above embodiment, the gasoline fuel starting device is configured by the yoke wire 27, the yoke lever 23, the yoke arm 28, the second yoke arm 31, the coil spring 35, etc., and the yoke release wire 32, the yoke release lever 33, the coil spring 35b, etc., constitute a chi yoke release device.

Therefore, its operation is as follows.

Now, if you try to start using gasoline fuel, pull the chain yoke release wire 32 in the direction of arrow B in Figure 3 (to the left in the figure) and release the second chain yoke arm 3
apart from the abutment of the second chiyoke arm 31
allows for clockwise rotation. When the yoke wire 27 is pulled, the yoke lever 23 rotates clockwise as shown in the figure, and the yoke arm 28 is rotated by the coil spring 3.
By similarly rotating it clockwise using the elastic force of 4, the check valve 21 is fully closed.
The rotation of the valve lever 23 also rotates the throttle lever 25 clockwise around the throttle shaft 24 via the link 26, and the throttle arm 29 is rotated in the figure against the spring force acting in the valve closing direction. Rotate clockwise to open the throttle valve 7 to a predetermined degree.

In addition, when attempting to start using LPG fuel, pull the chiyoke wire 27 in the direction of the arrow in FIG.
Return 2 in the direction of the arrow. Then, the yoke release lever 33 rotates counterclockwise in the figure and comes into contact with the second yoke arm 31. Therefore, even if the chiyoke lever 23 rotates clockwise, the chiyoke arm 28
The coil spring 34 is simply wound up by the contact between the second check arm 31 and the check release lever 33, and cannot follow the rotation of the check lever 23, thereby holding the check valve 21 in an open state. Then, the throttle lever 23 is only opened by the predetermined opening degree as described above via the link 26, the throttle lever 25, and the throttle arm 29. That is, by simultaneously operating the check wire 27 and the check release wire 32, the check valve 21 is fully opened and the throttle valve 7 is opened by a predetermined opening degree. For this reason, the primary barrel 3
An intake flow is generated according to the opening degree of the throttle valve 7, which generates negative pressure in the nozzle 2, and a pressure difference is generated between the vaporizer secondary chamber (not shown) and the LPG passage 9. LPG fuel is supplied from the engine through the nozzle 2, making it possible to start the engine easily.

Next, after starting, the engine is rotated for a predetermined period of time, and when warm-up is completed, the choke wire 27 is returned, the throttle valve 7 is closed, and the engine is maintained at a predetermined idling opening to perform idling operation.

In addition, in the above configuration, the second chiyoke arm 3 is attached to the chiyoke valve shaft in addition to the chiyoke arm.
1 is pivotally mounted, and by the contact between the second yoke arm 31 and the yoke release lever 33, the yoke valve is held in a fully open state when starting LPG fuel.
It is also possible to configure the yoke release lever 33 to be able to directly contact the yoke arm 28 without providing the yoke arm 28. Furthermore, instead of the chiyoke wire 27, a known bimetallic chiyoke mechanism may be used to automatically perform the chiyoke action, and it does not matter whether the chiyoke action is performed manually or automatically. Furthermore, the check release lever 33 may be automatically operated in conjunction with a fuel switching valve installed in the LPG fuel passage.

In addition, in the above, the LPG nozzle is placed upstream of the primary and secondary nozzles for gasoline.If the LPG nozzle is placed on the primary and secondary sides, Since the fuel connection to the
This is because the amount of air that is the sum of the amount of intake air on the primary side and the amount of intake air on the secondary side can be taken in from a single nozzle.

As described above, according to the present invention, in a carburetor that uses different types of fuels, if there is a specific fuel nozzle upstream of the choke valve, the upstream fuel nozzle is used to supply fuel and start the engine. When attempting to do so, the throttle valve opening can be adjusted using the Chi-Yoke device while the Chi-Yoke valve is held in the fully open position, whereas the Chi-Yoke device is configured to fully close the Chi-Yoke valve. An amount of intake air corresponding to the opening degree of the throttle valve is generated in the side nozzle, and starting fuel can be supplied from this nozzle. Further, since the opening degree of the intake throttle valve can be adjusted by the amount of operation of the choke wire, the adjustment is extremely easy. Therefore, startability is improved regardless of which of the different types of fuel is used, and battery consumption does not deteriorate.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a conventional LPG-gasoline combination vaporizer, Fig. 2 is an explanatory diagram of a conventional chiyoke device,
FIG. 3 is an explanatory diagram of the chioke device according to the present invention, and FIG. 4 is a sectional view taken along line AA when starting with LPG fuel in FIG. DESCRIPTION OF SYMBOLS 1... Carburetor, 2... Nozzle, 3... Primary side barrel, 5... Nozzle, 7... Throttle valve, 21... Chi York valve, 22... Chi York valve shaft, 23... Chi York lever, 24... ...Throttle shaft, 25...Throttle lever, 26...
...Link, 27...Chiyo Wire, 28...
Chiyoke arm, 29...Throttle arm, 3
DESCRIPTION OF SYMBOLS 1...Second yoke arm, 32...Yoke release wire, 33...Yoke release lever, 3
4,35...Coil spring.

Claims (1)

[Claims] 1 A fuel nozzle for LPG, a choke valve, a fuel nozzle for gasoline, and an intake throttle valve are arranged in series along the intake flow, and when starting with gasoline fuel, the choke valve is fully closed and the intake throttle valve is fully closed in relation to the operation of the choke wire. In a mixed fuel carburetor equipped with a gasoline fuel starting device in which a choke valve and an intake throttle valve are configured in conjunction with each other so that the throttle valve opens to a predetermined opening degree, when starting with LPG fuel,
Among the operating conditions of the above gasoline fuel starting device,
A chiyoke device for a carburetor that uses different fuels, characterized in that it is provided with a chiyoke release device that fully opens the chiyoke valve while keeping the intake throttle valve open to a predetermined degree using a separate operating tool.