JPS61279768A - Alcohol engine starter - Google Patents

Abstract

PURPOSE:To enhance the starting performance of an engine with less modification to a carburetor body, by providing such an arrangement that a highly combustible auxiliary fuel is fed into the inlet port of a carburetor float chamber through a three-way selector valve device during cold-engine starting. CONSTITUTION:A main fuel passage 22 led from a main fuel (alcohol) tank 1 and disposed therein with a main fuel pump 2 and a main fuel filter 3, is connected the main communication port 24 of a solenoid three-way selector valve 4. Further, an auxiliary fuel passage 24 led from an auxiliary fuel (gasoline) tank 10 and disposed therein with an auxiliary fuel pump 11 and an auxiliary fuel filter 12 is connected to a subsidiary port 25 of the above-mentioned three-way valve 4 whose outlet port side is connected to the inlet port 8a of a float chamber in which a needle valve 8 is disposed, in the carburetor 5. Further, a control device 17 controls the three-way valve and the fuel pumps 2, 11 such that the main fuel is fed into the engine when the temperature of the engine detected by a temperature sensor 8 is higher than a set value while the auxiliary fuel is fed when the temperature of the engine is below the set value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] This invention relates to a starting device for a carburetor type engine that uses alcohol as its main fuel.

[Conventional technology 1 Alcohol can be used as an engine fuel in place of ■gasoline. ■It is generally attracting attention because of its clean exhaust, but if this is used as the main fuel, there will be problems with startability. Therefore, as a starting device for the engine in such cases, an engine starting device with a carburetor has been proposed that allows the use of a different fuel, that is, gasoline, which has higher flammability than alcohol, during cold starting [8□ □59-165952□Ka□,.
[][5゜This conventional one supplies the main fuel alcohol to the carburetor□/,
(7) (Jt yarn feeding system and other 1, Kiichi machine,) Ziawe 21. An auxiliary fuel tank that stores cadsoline is connected to the auxiliary passageway, and the auxiliary passageway is opened and closed according to commands from the control device.11-:.

It is equipped with vi4r11 valves. In the conventional model, this I゛,- configuration allows the gas to be directly connected to the main well during a cold start.
The storage area in the float chamber is
::(・j This is an attempt to start the engine early regardless of the amount of alcohol.

[Problems to be Solved by the Invention] However, such conventional alcohol engine starting devices have a structure that supplies gasoline directly to the main well of the carburetor when the engine is cold, so the following problems occur. It has some problems.

■ Due to the structure of the carburetor, it is necessary to change the fuel passage inside the main body, making modification difficult. Even if it is modified or newly installed, there will be no commonality with gasoline use, resulting in high costs.

■ If the engine does not start after cranking, gasoline will flow into the carburetor body due to the head difference, making it difficult to start after zero.

This invention focuses on the fact that the amount of alcohol stored in the float chamber is small, and by appropriately processing this alcohol, it is possible to improve cold startability without significantly modifying the carburetor body. The purpose is to provide an engine starting device.

In addition, there is a conventional device similar to this invention that uses fuel injection valves and injects different types of fuel with a common injection valve or with separate injection valves depending on the respective usage conditions (
(Refer to Utility Model Publication No. 36-5204 and Japanese Unexamined Patent Publication No. 58-48736). However, these methods do not use a mechanical carburetor, but instead use fuel injection valves that are controlled electronically, so they are different from the present invention.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides an engine with a carburetor that uses alcohol as the main fuel. an auxiliary fuel tank for storage, a 3-way valve device having a main communication port and a sub-communication port and switchingly connecting either of the communication ports to the inlet of the float chamber of the carburetor, and a main fuel pump that connects the main communication port and the main A main fuel passage connecting the fuel tank, an auxiliary fuel passage having a auxiliary fuel pump and connecting the auxiliary communication port and the auxiliary fuel tank, and a main fuel passage connecting the auxiliary fuel tank to the auxiliary fuel tank. 3 above to supply auxiliary fuel below.
It is equipped with a control device that controls the operation of a direction valve device, a main fuel pump, and an auxiliary fuel pump.

[Function] When the engine is cold, the control device operates the three-way valve device and connects the auxiliary fuel system. In this case, either remove some of the alcohol stored in the float chamber or set the fuel pressure of the auxiliary fuel pump to a higher level. This causes the secondary fuel, gasoline, to enter the float chamber and mix with alcohol. Therefore,
When cranking, the engine starts easily. After a complete explosion, the main fuel pump is energized and the three-way valve device is opened and closed by duty control, etc., and the fuel is gradually switched to alcohol fuel.
℃ or higher), only the main fuel pump operates to supply alcohol fuel from the beginning.

This is because starting is good in this case. As a result of the above, the modification of the vaporizer requires only minor changes.

[Example] Examples of the present invention will be described below.

FIG. 1 is a diagram showing a first embodiment of the invention. First, to explain the structure, the main fuel tank 1 stores alcohol, which is the main fuel, and the main communication port 24 of the left three-way switching solenoid valve (three-way valve device) 4 is connected to the main fuel tank 1. Connect at passage 22 - this! .

A main fuel pump 2 and a main fuel filter 3 are installed in the passage 22 in this order from upstream. Further, the auxiliary fuel tank 10 contains gasoline as an auxiliary fuel, that is, Al, -7, yo□□. ,
Yes□□Eh. sor, 0 [reto, 3-way solenoid valve 4
is connected to the sub-communication port 25 by a sub-fuel passage 23, and an in-tank type sub-fuel pump 11 and a sub-fuel filter 2 are interposed in this passage 23. It is installed on the engine (as shown)! , the carburetor 5 floats a float 7 in a float chamber 6, and its buoyancy causes the needle valve 8 to float.
Press to maintain the level W of fuel entering from the float chamber inlet 8a at the specified value. The fuel in the float chamber 6 is a venturi in a carburetor.

When negative pressure is applied to contact 1 due to air flow, main jet 2
]:; The same amount of fuel is ejected from the main nozzle 21 according to the air flow rate. Main fuel tank 1 litter
The D-pipe 9 is branched from the main communication port 24 of the three-way switching solenoid valve 4, and is connected to the fuel pipe 14 that connects the pipe 9 to the connector 13 of the float chamber 6. The D-pipe 9 is connected to the fuel pipe 14 that connects the pipe 9 to the connector 13 of the float chamber 6. A fuel pump 16 is provided to remove fuel from the chamber 6. Temperature sensor 1 for engine cooling water temperature
8 and the intake negative pressure switch 19 of the engine intake pipe, the control device 17 inputs the signals of the three-way switching solenoid valve 4, the main fuel pump 2, the auxiliary fuel pump 11, the opening/closing solenoid valve 15, and the fuel pump depending on the engine state. Wire to output to 16. FIG. 2 shows a specific example of the three-way switching solenoid valve 4, in which a valve body 27, a spring 28, and an electromagnet 29 are housed in a main body 26.
When energized, the valve body (armature) 27 is pulled down against the spring 28, the main communication port 24 on the right side is closed, and the sub communication port 25 on the upper side is closed.
It is constructed so that it opens and communicates with the float chamber 8a.

Next, the effect will be explained.

When the ignition switch is turned on with the engine stopped, the control device outputs output to each electromagnetic valve and fuel pump to control their operation, depending on the input status.

(1) When it is cold (when the cooling water temperature is below the set temperature between 20°C and 30°C), the control device 17
Since the signal No. 8 is received, the on-off solenoid valve 15 is first opened and the output power is applied to drive the fuel pump 16. As a result, the alcohol stored in the float chamber 6 is returned to the main fuel tank 1 through the pipe 16, the solenoid valve 15, the fuel pump 16, and the return pipe 9. This time may be a short period of time, such as a few seconds, after which the power to both is stopped.

Next, the three-way switching solenoid valve 4 is energized to open the auxiliary communication port 25 and close the main communication port 24 as shown in FIG. 2, and the in-tank type auxiliary fuel pump 11 is energized. As a result, the auxiliary fuel and gasoline in the auxiliary fuel tank 10 drop to the level W via the auxiliary fuel pump 11, the auxiliary fuel filter 12, the auxiliary fuel passage 23, the auxiliary communication port 25, the float chamber inlet 8a, and the needle valve 8. The liquid enters the float chamber 6 where it is being heated, and mixes with the alcohol collected at the bottom. The height position for installing the connector 13 on the Nilevel W is selected so that the mixing ratio of gasoline is equal to or higher than that of alcohol.

In this state, when the driver turns on the starter switch and cranks the engine, the mixed fuel in the float chamber 6 passes through the main jet 20 and is ejected from the main nozzle 21. The water is also ejected from a slow boat (not shown) that communicates with the float chamber 6. These amounts are supplied to the engine in accordance with the amount of air passing through the venturi, and since the combustibility is high, the engine starts easily.

When the engine starts and explodes, negative suction pressure develops.
The control bag @ 17 receives a signal from the suction negative pressure switch 19 and stops energizing the three-way solenoid valve 4 and the auxiliary fuel pump 11, and at the same time starts energizing the main fuel pump 2. As a result,
In the three-way switching solenoid valve 4, the valve body 27 is raised by a spring 28, as shown by the dashed line in FIG. 2, to close the sub-communication port 25 and open the main communication port 24. As a result, alcohol in the main fuel tank 1 is transferred to the main fuel pump 2, the main fuel filter 3, and the main fuel passage 22.
, the main communication port 24, the float chamber port 8a and the needle valve 8 portion to the float chamber 6, and the fuel therein is gradually switched to alcohol. Therefore, the engine is operated with alcohol, which is the regular main fuel, to clean the exhaust gas.

(2) Warm time (when the cooling water temperature is higher than the above-mentioned set temperature)
In response to the signal from the temperature sensor 18, the controller 17
The directional switching solenoid valve 4, the opening/closing solenoid valve 15, the III fuel pump 12, and the fuel pump 16 are energized, and only the main fuel pump 2 is energized. This supplies alcohol from the beginning. At such warm times, there is no problem in starting with alcohol fuel, but (2).

In the embodiment described above, the carburetor 5 does not require any modification to the main body and only requires adding a solenoid valve and a fuel pump, so it is possible to avoid the difficulty of modifying the carburetor as in the past.
Moreover, it does not cause an increase in cost.

Furthermore, even if the engine does not start during cranking, the supply of gasoline, which is auxiliary fuel, depends on the solenoid valve 4 and the pump 11, so by stopping the operation of both, the conventional gravity action can be avoided: '' will not cause gasoline to flow into the carburetor body.

FIG. 3 shows a second embodiment. In this embodiment, mixed fuel in the float chamber is produced by adjusting the fuel pressure without handling the float chamber alcohol as in the first embodiment.

That is, the connector 13, fuel pipe 14, fuel solenoid valve 15, and fuel pump 16 shown in FIG.
An orifice 30 for adjusting the fuel pressure is provided in the. This reduces the fuel pressure at the main fuel pump 2 to 0°2~0, 15k! II
/cgi2, and set the fuel pressure at the auxiliary fuel pump 11 to a higher value than the former, for example, about 0.25 to 0.45 kQ10 2.

For this reason, the three-way switching solenoid valve 4 is controlled by the cold time control device 17.
When the auxiliary fuel pump 11 is energized, the fuel pressure of gasoline, which is the auxiliary fuel, reaches the float chamber 6 from the float chamber 8a through the needle valve 8.

Since this fuel pressure is higher than the fuel pressure of the alcohol fuel previously stored in the float chamber 6, the float level W rises by the higher amount, and this added gasoline eventually mixes with alcohol.

Therefore, when the starter switch is turned on and the engine is cranked from the above-mentioned state, since the alcohol side of the main fuel is stopped, the mixed fuel gradually becomes richer and is supplied to the engine, making it easier to start the engine.

After starting, the fuel is switched to the main fuel side as in the previous embodiment. However, the switching may be performed all at once as described above, but the duty may be controlled by turning on and off gradually. In that case, the duty is set to mix 10 to 30% of the auxiliary fuel to the main fuel, and the duty cycle is set within the range of 2 to 20H2. When the cooling water temperature exceeds the set temperature (for example, 30°C), from then on, the power to the three-way solenoid valve 4 is stopped and the alcohol is turned off.
00% is supplied to the vaporizer 5. When the duty control as described above is performed during warm-up, the fuel changeover is performed smoothly and gradually.
There is one place.

FIG. 4 shows a third embodiment. In this embodiment, like the second embodiment, a mixture of cicada fuel is created by adjusting the fuel and pressure at startup, but when warming up after startup, alcohol return fuel is returned to the fuel pump inlet. This is intended to promote warm-up and improve drivability.

That is, in FIG. 4, the return pipe 9 is similarly provided with an orifice 30 for adjusting the fuel pressure, but a pipe 32 is provided that connects and branches from the return pipe 9 to the inlet 2 of the main fuel pump, and a pipe 32 is provided at this branch part. , a switching solenoid valve 31 is provided, which can be operated by a command from the control bag fi17.

During a cold start, as in the previous embodiment, the mixed fuel is used by adjusting the fuel pressure to facilitate the start. After the start is complete, when the control device 17 energizes the switching solenoid valve 31, excess alcohol fuel is generated by the operation of the main fuel pump 2. The fuel is returned to the inlet of the main fuel pump 2 via the return pipe 9, the switching solenoid valve 31, and the piping 32. As a result, the returned fuel does not return to the main fuel tank 1, which is cooled by the outside temperature, but passes through the main fuel pump 2, whose temperature has increased due to operation, and is therefore heated and its temperature increases.

Alcohol fuel whose temperature has increased in this way □
- es70-t-W6 □ engineering, huh. 8ゎ
! □ This improves fuel atomization and improves warm-up time.
From 1□□0 to 8□Oh,□. , 6° 1) When the temperature exceeds 30″C, the switching solenoid valve 31 is de-energized and becomes the normal return path to the main fuel tank 1.
,.

[Effect of the invention]
As explained above, according to the present invention, the configuration is installed at the inlet of the float chamber of the carburetor during cold start.
□゛□Since the auxiliary fuel (gasoline) is supplied via a 3-way valve device, modification of the carburetor body is reduced.
□:) 1 engine 0 startability using Al 1-le as main fuel 8
The effect of improving the inside of li can be obtained.
,! 1,)

[Brief explanation of drawings]

□llc, t, knee. -0□1-68-〇Wow. , ・
j: 1 □2□;t11゜,) Wow, ヮ□1□3□6. :)1
・J['r Overall view showing the second embodiment, Fig. 4 is also No. 31')
FIG. 1 is an overall diagram showing an example. Explanation of symbols appearing in the drawings 1... Main fuel tank 2... Main fuel pump 3.
...Main fuel filter 4...Three-way valve device 5...Carburizer 6...Float chamber 7...Float 8...Needle valve 9...Return pipe 1
0...Auxiliary fuel tank 11...In-tank type auxiliary fuel pump 12...Auxiliary fuel filter 15...Opening/closing solenoid valve 16...Fuel pump 17
...Control circuit 18...Temperature sensor 19...
・Suction negative pressure switch 20...Main jet 22...Main fuel passage 23
...Auxiliary fuel passage 24...Main communication port 25...
Sub-communication port 30... Orifice 31... Switching solenoid valve

Claims (1)

[Claims] In engines with a carburetor that use alcohol as the main fuel,
A main fuel tank that stores alcohol, an auxiliary fuel tank that stores auxiliary fuel with higher combustibility than alcohol, and a main communication port and a sub-communication port, and one of the communication ports is selectively connected to the inlet of the float chamber of the carburetor. a main fuel passage having a main fuel pump and connecting the main communication port and the main fuel tank; and a sub-fuel passage having a sub-fuel pump and connecting the sub-communication port and the sub-fuel tank. , a control device that controls the operation of the three-way valve device, the main fuel pump, and the auxiliary fuel pump so as to supply main fuel at a temperature above a set temperature and auxiliary fuel at a temperature below a set temperature in relation to engine humidity at the time of startup; An alcohol engine starting device characterized by being provided with.