JPS639661A - Automatic starter for carburetor of outboard motor - Google Patents

Abstract

PURPOSE:To prevent leakage of oil due to the tilting of carburetor at the start, by opening an open section a starting fuel lead-in path into a float chamber below predetermined liquid level under some operating position of an outboard motor while opening said open section above predetermined liquid level under tilt-up condition. CONSTITUTION:In a carburetor C for an outboard motor, a float chamber body 4 is arranged at a lower portion of the carburetor body 1 and a float chamber 5 is formed by said bodies 1, 4. Said float chamber 5 is communicated through a starting fuel lead-in path 8, a starting fuel chamber 7, a starting fuel nozzle 9 the opening area of which is varied by a valve body 10 and a starting path 6 to the inside of an intake path in the upstream and downstream of a throttle valve 3. Here, the position of an open section 8A of the starting fuel path 8 to the float chamber 5 is set above an inclined liquid level X-X under tilt-up condition of the outboard motor. Consequently, the fuel in the float chamber 5 is completely prevented from flowing out through the starting fuel nozzle 9 to the intake path 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a carburetor that supplies and controls a mixture to be supplied to an outboard engine, and particularly relates to a carburetor that supplies and controls a mixture to an outboard engine. The present invention relates to an automatic starting device for an outboard motor carburetor that automatically supplies and controls an optimal starting air-fuel mixture.

[Conventional technology]

Conventionally, as an automatic device for outboard motor carburetors.

The starter system automatically opens and closes the choke valve located in the intake passage, and the starting passage that connects the upstream and downstream of the throttle valve automatically opens and closes to control the starting air-fuel mixture. There is a one-start type, and one of these systems is selected as appropriate for the engine starting operation and starting performance.

The present invention relates to the latter one-type starter that automatically opens and closes the starting passage.

A conventionally commonly used method will be explained with reference to FIG. 1. Reference numeral 1 denotes a carburetor main body through which an intake passage 2 passes, and a throttle valve 3 for opening and closing the intake passage 2 is disposed within the intake passage.

A float basic body 4 is disposed at the lower part of the carburetor main body l, and a float chamber 5 is formed by the carburetor main body l and the float basic body 4, and a float (not shown) and an end of the fuel inflow path are contained in the float chamber 5. The liquid level x is always constant due to the cooperative action of the valve seat located in the area and the float valve that opens and closes the valve seat.
-x is formed. The upstream and downstream sides of the throttle valve 3 (in the figure, the downstream right side is the engine side, and the upstream left side is the air cleaner side) are connected by a starting passage 6, and a starting fuel chamber 7 is formed below this starting passage 6. Ru. The starting fuel chamber 7 is connected at its lower part to a constant liquid level xx in the float chamber 5 by a starting fuel introduction passage 8, and its upper part is connected to the atmosphere through an atmosphere opening hole (not shown). Therefore, the fuel in the float chamber 5 is introduced into the starting fuel chamber 7 from the starting fuel introduction passage 8, and a liquid level at the same level as the constant liquid level xx in the float chamber 5 is formed. Further, an upper opening 9A of the starting fuel nozzle 9 is opened in the middle part of the starting passage 6, and a lower opening 8B of the starting fuel nozzle 9 is submerged below a constant liquid level in the starting fuel chamber 7. Reference numeral 10 denotes a valve body disposed corresponding to the upper opening 9A of the starting fuel nozzle 9, and the lower end of this valve body 10 includes a valve portion 10A that can close the upper opening 9A, and an opening area of the upper opening 8A. A tapered needle valve 9B that can be changed in accordance with the movement of the valve body 10 is disposed.

Further, reference numeral 11 is a heat sensitive response body which is heated by a PTC heater 12 having positive temperature characteristics, is sealed with a thermal expansion material such as paraffin or olefin, and has an output rod 11A protruding from its end. The output rod 11A of the heat sensitive responsive body 11 is engaged with the valve body via the transmission member 12. That is, the PTC heater 12, the heat sensitive response body 11, the transmission member 12. The valve body lO1 forms an automatic temperature control valve.

In addition, 13 is a spring that presses the transmission member 12 to the output rod 11A, and 14 is a spring that presses the transmission member 12 against the valve body 1 more than necessary.
This is an interference spring that prevents pressing 0.

The opening/closing characteristics of the upper opening 9A of the starting fuel nozzle 9 with respect to the temperature of the automatic temperature control valve are, for example, as shown in FIG.
The needle valve 10B fully opens the upper opening 9A, and as the temperature rises, the output rod 11A,
By gradually pressing the valve body 10 downward using the transmission member 12, the effective area of the upper opening 9A is gradually reduced by the needle valve IQB, and the valve body 10A is closed at +60°C. is fully opened.

Incidentally, this opening/closing characteristic should be optimally matched to the engine, and the carburetor C for such an outboard motor is in the state shown in Fig. 3 with respect to the engine E, that is, the engine side is on the right and the air cleaner side is on the right. It is arranged as shown on the left, and this engine E
The outboard motor F is equipped with a screw S, a screw T, etc., and is then attached to the hull P.

[Problem that the invention seeks to solve]

According to such a conventional automatic starting device for an outboard motor carburetor,
When the engine is started, the heat-sensitive body 11 automatically senses the engine ambient temperature, controls the valve body 10 to the optimum position via the output rod 11A and the transmission member 12, and controls the starting fuel/throttle 9.
The gap between the upper opening 9A and the needle valve 10B is set, and the optimum starting mixture concentration for the temperature condition is determined and supplied to the engine, thereby satisfying the starting operation of the engine.

Here, when looking at the state when the outboard motor F is attached to the hull P, there are two main states:

The first is the operating state of the outboard motor F, in which the screw S of the outboard motor F is submerged in water to provide grip to the hull. Even in this operating state, there is a shallow water operation in which the screw S is pulled up close to the water surface (to avoid collision of the screw with obstacles in the shallow water), and a normal operation.

Second, when pulling the hull P onto land and storing it or holding it at a port, in order to prevent corrosion caused by water, it is important to prevent the propeller from hitting the ground or water surface when pulling the outboard motor above the water surface. There is a so-called tilt-up state, which is a non-operating state, in which the external machine F is rotated counterclockwise (in a direction in which the air cleaner side of the carburetor faces downward) in the figure.

As mentioned above, there are two ways in which the outboard motor can be arranged. The opening position of the starting fuel nozzle 9 must be selected particularly carefully. If this selection is not made properly, the upper opening 9A of the starting fuel nozzle 9, especially in an automatic starting device at room temperature as shown in FIG. Since this is open, it may flow from the float chamber 5 or the starting fuel chamber 7 to the engine F through the intake passage 2 through the passage or opening, causing a state in which the engine cannot be started, which is not desirable. Ta.

[Means for solving problems]

The automatic starting device for an outboard motor carburetor according to the present invention has been developed in view of the above-mentioned problems, and completely prevents fuel leakage from the starting system of the carburetor in the above-mentioned operating and non-operating conditions. The purpose of this invention is to provide the above-mentioned apparatus, and to achieve the above-mentioned object, the following structure is adopted.

That is, in an engine operating state where the outboard motor screw is underwater, the opening of the starting fuel introduction passage into the float chamber is opened below a certain level of liquid in the float chamber, and the outboard motor screw is pulled up to the atmosphere. In the non-operating state in the tilt-up state, the opening of the starting fuel introduction passage into the float chamber is opened above a constant liquid level in the float chamber.

[Effect]

When the engine is in operation, the starting fuel can be supplied from the starting fuel introduction passage into the starting fuel chamber, so that the starting fuel can be supplied and the engine can be started satisfactorily.On the other hand, when the engine is not in operation, Since the opening of the starting fuel introduction passage to the float chamber opens above a constant liquid level in the float chamber, the fuel in the float chamber will not flow out into the intake passage through the starting fuel nozzle in the inclined non-operating state. ,
[Embodiment] Hereinafter, an embodiment of an automatic starting device for an outboard motor carburetor, which has not yet been invented, will be described. In the drawings, the same reference numerals are used for the same parts as in the conventional one, and the description thereof will be omitted.

In other words, the present invention is advantageous in that the opening position of the starting fuel introduction passage 8 that connects the float chamber 5 and the starting fuel chamber 7, the opening position of the starting fuel nozzle 9, and the lower opening 9B of the starting fuel nozzle 9, The opening position with respect to a constant liquid level x-X in the chamber 5 is specified.

FIG. 4 shows the arrangement of the carburetor with respect to the horizontal plane when the screw S of the outboard motor F is normally submerged in water. In this state, the opening 8A of the starting fuel passage 8 to the float chamber 5 The position of is the constant liquid level x-x of the float chamber 5
On the other hand, the upper opening 9A of the starting fuel nozzle 9 is above the constant liquid level XX, and the lower opening 9B is above the constant liquid level
It's under x.

In this state, the starting fuel is supplied from the opening 8A of the starting fuel passage 8 into the starting fuel chamber 7, so that the air-fuel mixture necessary for starting is formed, and engine starting is satisfied. Since the upper opening 9A of the fuel nozzle 9 is above a constant liquid level xx, no unnecessary fuel flows out into the intake passage.

Next, referring to FIG. 5, the shallow water state in which the screw S of the outboard motor F is raised from the normal state (rotated counterclockwise) will be explained.
The constant liquid levels x and -X (which form the same liquid level as the constant liquid level in the float chamber 5) change as shown in the figure. At this time, the opening 8A of the starting fuel passage 8 is still under the same constant liquid level as in the above state, and the upper opening 9A of the starting fuel nozzle 9
is above a constant liquid level and the lower opening is below a constant liquid level. Therefore, the same problem does not arise when starting the engine when traveling in such shallow water.

Next, the state of the carburetor in the tilt-up state where the screw S of the outboard motor F is pulled up above the water surface (the outboard motor F is rotated further counterclockwise than when running in shallow water) will be explained using Fig. 6. The opening 8A of the starting fuel passage 8 opens above the constant liquid level X2 X2, and the upper opening of the starting fuel nozzle 9 opens above the constant liquid level x2-X2. Therefore, in such a state, the fuel in the float chamber 5 will not flow out from the starting fuel nozzle 9 into the intake passage 2, and the engine will not be unable to start.

In the above, the positions of the upper opening 8A and lower opening 8B of the starting fuel nozzle 9 are set relative to a constant liquid level, but when the capacity in the starting fuel chamber 7 is small, the influence of leakage of the fuel amount is small. Therefore, there is no need to select the location.

Further, as for the opening of the starting fuel nozzle 9 with respect to a constant liquid level, it is sufficient that either the upper opening 8A or the lower opening 9B is above the constant liquid level.

〔Effect of the invention〕

As described above, the automatic starting device for an outboard motor carburetor according to the present invention has the following effects.

■When the engine is in operation, the opening of the starting fuel introduction passage to the float chamber is located above a constant liquid level in the float chamber, which maintains good starting performance. In this state, since the opening of the starting fuel introduction passage to the float chamber is opened above a constant liquid level, unnecessary starting fuel will not flow out from the starting fuel nozzle into the intake passage.

■In particular, when it is necessary to increase the volume of the starting fuel chamber in order to improve warm-up characteristics when starting the engine, we have set the positions of the upper and lower openings of the starting fuel nozzle. This makes it possible to further improve starting performance.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the main parts of a conventional automatic starting device for an outboard motor carburetor, Figure 2 is a diagram showing the relationship between the opening of the starting fuel nozzle and temperature, and Figure 3 is a diagram showing the relationship between the opening of the starting fuel nozzle and temperature. Fig. 4 is a state diagram of the carburetor in normal operating condition.
Fig. 5 is a state diagram of the carburetor showing the shallow water operation state, Fig. 6 is a state diagram of the carburetor showing the tilt-up state of the non-operation state,
It is. C08, Vaporizer, E,, @Seki, Fo. Outboard motor, S01. Screw, Plo, hull,
586. Float chamber, 600. Starting passage, 700. Starting fuel chamber, 811. Starting fuel introduction passage, 8A, opening, 901. Starting fuel nozzle, 9A, upper opening, 9B, lower opening. y78 J 2 , q6

Claims (2)

[Claims] (1) A float chamber is formed below the carburetor main body to store a constant liquid level inside, and a starting fuel chamber is formed adjacent to the float chamber, and the float chamber and the starting fuel chamber are started. A fuel introduction passage communicates the two, and a starting passage connects the upstream and downstream sides of a throttle valve disposed in an intake passage passing through the carburetor body, and a starting fuel nozzle is opened in the starting passage, and the lower end of the starting fuel nozzle is connected to the starting passage. immersed under a constant liquid level in a starting fuel chamber, corresponding to the opening of the starting fuel nozzle to the starting passage, closing the opening in a high temperature state and opening the opening in a low temperature state; In an automatic starting device for an outboard motor carburetor equipped with an automatic temperature control valve, when the outboard motor is in operation with the screw submerged in the water, the opening of the starting fuel introduction passage into the float chamber is connected to a certain amount of liquid in the float chamber. Open below the surface,
A carburetor for an outboard motor in which the opening of the starting fuel introduction passage into the float chamber is opened above a constant liquid level in the float chamber when the outboard motor screw is raised to the atmosphere and the outboard motor is tilted up in a non-operating state. automatic starting device. (2) A float chamber is formed below the carburetor main body to store a constant liquid level inside, and a starting fuel chamber is formed adjacent to the float chamber, and the float chamber and the starting fuel chamber are started. A fuel introduction passage communicates the two, and a starting passage connects the upstream and downstream sides of a throttle valve disposed in an intake passage passing through the carburetor body, and a starting fuel nozzle is opened in the starting passage, and the lower end of the starting fuel nozzle is connected to the starting passage. immersed under a constant liquid level in a starting fuel chamber, corresponding to the opening of the starting fuel nozzle to the starting passage, closing the opening in a high temperature state and opening the opening in a low temperature state; In an automatic starting device for an outboard motor carburetor equipped with an automatic temperature control valve, when the outboard motor is in operation with the screw submerged in the water, the opening of the starting fuel introduction passage into the float chamber is connected to a certain amount of liquid in the float chamber. The upper opening of the starting fuel nozzle to the starting passage is opened above the constant liquid level in the float chamber, and the lower opening of the starting fuel nozzle to the starting fuel chamber is opened above the constant liquid level in the float chamber. At the same time, the screw of the outboard motor is raised to the atmosphere, and in the tilted up state and non-operating state, the opening of the starting fuel introduction passage into the float chamber is opened above a constant liquid level in the float chamber, and the outboard motor is started. An automatic starting device for a carburetor for an outboard motor, in which at least one of an upper opening to a starting passage of a fuel nozzle or a lower opening to a starting fuel chamber is disposed above a constant liquid level in a float chamber.