JPH066926B2 - Fuel supply device for ship propulsion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel supply device for a marine propulsion engine such as an outboard motor, an outboard motor, an inboard motor, or the like.

[Prior Art] A ship propulsion device is installed and used in an engine room, a stern plate, or the like of a ship. This engine for a marine propulsion device is additionally provided with a fuel supply source such as a carburetor and a fuel injection device, and fuel supplied from the fuel supply source can be introduced into a combustion chamber of the engine through a fuel supply path.

[Problems to be Solved by the Invention] However, an engine for a marine propulsion device is, as compared with an engine for an automobile, an uneven load state of a ship, an accelerating state of a ship, a wave state, a trim in an outboard motor or the like. The engine posture is likely to change due to changes in the angle setting state and the like. The change in the engine posture changes the relative positional relationship between the fuel supply source such as the carburetor and the combustion chamber. Therefore, when the combustion chamber is located at a higher level than the fuel supply source as compared with the standard positional relationship, gravity acts as a resistance against the flow of fuel from the fuel supply source to the fuel chamber. However, the amount of fuel supplied to the fuel chamber is reduced below the standard supply amount, resulting in inconvenience such as an output reduction unintended by the driver.

It is an object of the present invention to automatically increase / decrease the amount of fuel supplied to an engine in accordance with a change in the attitude of the engine, and secure a fuel supply state that is optimum for the operating state of the engine.

[Means for Solving Problems] The present invention relates to an engine attitude detecting means for detecting a change in the attitude of the engine and a fuel attitude detecting means for detecting the attitude change of the engine, in a fuel supply device for an engine for a marine propulsion apparatus installed and used in a ship. And a fuel supply amount control means for adjusting the fuel supply amount to the engine based on the detection result.

[Operation] According to the present invention, the fuel supply amount to the engine is controlled by the fuel supply amount control means based on the detection result of the engine attitude detection means to ensure the optimum fuel supply state for the operating state of the engine. It is automatically increased or decreased.

That is, for example, when the position of the engine causes the fuel chamber to be located higher than the fuel supply source, the resistance of gravity acting on the flow of fuel from the fuel supply source to the combustion chamber may be increased. The fuel supply is increased so as to offset the fuel decrease trend. On the other hand, in the case where the combustion chamber is located lower than the fuel supply source, the increasing tendency of the fuel due to the addition of gravity acting on the fuel flow from the fuel supply source to the combustion chamber is offset. Thus, the fuel supply is reduced.

Therefore, according to the present invention, the fuel supply amount to the engine is automatically increased or decreased according to the change in the attitude of the engine,
It is possible to secure the optimum fuel supply condition for the engine operating condition.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing an example of a vaporizer used for implementing the present invention.
FIG. 3 is a schematic diagram showing an outboard motor to which the present invention is applied, and FIG.
(A) to (C) are flow charts showing the control state in one embodiment of the present invention.

As shown in FIG. 3, the outboard motor 10 has a clamp brat 12 attached to a stern plate of a ship 11, and a swivel bracket 14 is attached to the clamp brat 12 via a tilt shaft 13.
Is supported so that it can be tilted (trim up / down), and the swivel bracket 14 supports the propulsion unit 15 so that it can be steered. Reference numeral 16 is a hydraulic trim cylinder provided between the clamp bracket 12 and the swivel brat 14, and trims the propulsion unit 15 between a trim down position shown by a solid line and a trim up position shown by a two-dot chain line in FIG. 1, for example. Up / down operation is possible. The propulsion unit 15 includes an engine 17, and the engine 17 includes a carburetor 18 and an intake box 19.

As shown in FIG. 2, the carburetor 18 includes a float chamber 20 and an intake passage 21, and the intake passage 21 has a choke valve 22,
A throttle valve 23 and a main discharge pipe 24 are arranged. Further, in the carburetor 18, a fuel supply amount adjusting pipe 25 is arranged inside the float chamber 20, a discharge port 25A of the adjusting pipe 25 is opened on the intake downstream side of the throttle valve 23, and an intake port 25B of the adjusting pipe 25 is provided. Is controlled by a solenoid valve 26. The solenoid valve 26 controls the ratio of the opening time and the closing time of the suction port 25B, that is, the duty ratio control, as described later in detail. Incidentally, in FIG.
Is an air bleed tube, and the solenoid valve 26 controls the duty ratio of the fuel passage before the air bleed. However, in the embodiment of the present invention, the duty ratio of the fuel passage after the air bleed is controlled. May be. That is, the fuel is discharged from the discharge port 25A to the intake passage 21 by the intake negative pressure of the engine 17 through the adjustment pipe 25 whose duty ratio is controlled by the solenoid valve 26, and is supplied to the combustion chamber through the fuel supply path (not shown). To be done.

The outboard motor 10 includes a control circuit for the carburetor 18 as shown in FIG.

In FIG. 1, 31 is a start switch of the engine 17, 32 is a trim angle sensor of the propulsion unit 15, and 33 is a trim angle sensor.
Is a temperature sensor of the engine 17, 34 is a throttle opening sensor of the carburetor 18, 35 is a knock sensor of the engine 17, and 36 is an engine speed sensor. 41 is C
PU (microcomputer), 42 is a memory, 43 is a clock circuit, and 44 is a duty control circuit.

The following data (1) to (4) are written in advance in the memory 42 for fuel control corresponding to each operating state of the engine 17.

A basic fuel supply amount A that is optimal (for example, an optimal setting that minimizes fuel consumption) for all combinations of the throttle opening and engine speed during normal operation of the engine 17, and a startup increase amount B engine 17 required when starting the engine 17. Increase in engine attitude C required to offset the increase / decrease in fuel due to change in attitude C. Increase in temperature required to optimize the operating state of engine 17 in response to temperature changes in engine 17 D Required during acceleration of engine 17 Acceleration amount increase E The knock amount increase F required to eliminate the knock when the engine 17 knocks occurs The basic fuel supply amount A is richer than the optimum fuel consumption value in order to correct the response delay of the throttle valve 23. When the throttle opening is constant under the condition set to
Since it is not necessary to consider the improvement of the responsiveness of the throttle valve 23, the throttle amount reduction G CPU 41, which can reduce the fuel consumption in order to optimize the fuel consumption, includes the on / off state of the starter switch 31, the detection results of the sensors 32 to 36, and the memory. Based on the data previously written in 42, the optimum fuel supply amount for the current operating state of the engine 17 is shown in FIG.
Calculation is performed according to the flow chart of (C). The duty control circuit 44 drives and controls the solenoid valve 26 at a duty ratio necessary to secure the optimum fuel supply amount based on the calculation result of the CPU 41.

That is, in this embodiment, the CPU 41 and the memory 4 are
2. Solenoid valve 2 based on duty ratio control circuit 44
By the drive control of 6, the fuel control operation shown in FIGS. 4 (A) to 4 (C) is executed. The respective modes constituting the fuel control operation will be described below.

Start-Up Increasing Mode Based on the output signals of the starter switch 31 and the temperature sensor 33, the duty ratio of the solenoid valve 26 is controlled so that the start-up increasing amount B stored in the memory 42 is executed. This increase in engine start amount ends when the engine speed sensor 36 detects that combustion of the engine 17 has continued.

Engine attitude increase mode Based on the output signal of the trim angle sensor 32, the memory 42
The duty ratio of the solenoid valve 26 is controlled so that the engine attitude increase C stored in the above is executed.

Chiller increase mode Based on the output signal of the temperature sensor 33, the duty ratio of the solenoid valve 26 is controlled so that the temperature increase D stored in the memory 42 is executed.

Acceleration increasing mode The change rate of the throttle valve 23 is detected by differentiating the output signal of the throttle opening sensor 34, and the memory 42
The duty ratio of the solenoid valve 26 is controlled so that the acceleration increase amount E stored in 1 is executed.

Knock amount increase mode Based on the output signal of the knock sensor 35, the duty ratio of the solenoid valve 26 is controlled so that the knock amount increase F stored in the memory 42 is executed.

Throttle reduction mode The output signal of the throttle opening sensor 34 detects that a certain throttle opening is maintained for a certain time or longer, and the throttle valve G stored in the memory 42 is executed so that the solenoid valve is executed. 26 is duty ratio controlled.

Next, the operation of the above embodiment will be described.

According to the above embodiment, the fuel supply amount to the engine 17 is determined by the CPU 4 based on the detection result of the trim angle sensor 32.
By the control operation No. 1, the fuel supply amount is automatically increased or decreased so as to secure the optimum fuel supply state for the operating state of the engine 17.

That is, for example, when the combustion chamber is located higher than the carburetor 18 due to a change in the posture of the engine 17, the resistance of gravity acting on the flow of fuel from the carburetor 18 to the combustion chamber is increased. The fuel supply amount is increased so as to offset the decrease tendency of fuel due to. On the other hand, in the case where the combustion chamber is located lower than the carburetor 18, the increasing tendency of the fuel due to the load of gravity acting on the fuel flow from the carburetor 18 to the combustion chamber is offset. Thus, the fuel supply is reduced.

Therefore, according to the above-described embodiment, the fuel supply amount to the engine 17 is automatically increased / decreased in accordance with the change in the attitude of the engine 17, and the fuel supply state optimal for the operating state of the engine 17 can be secured.

It should be noted that the present invention can be applied to a fuel supply device for an engine such as an inboard motor, an inboard motor, or an inboard motor, which has an engine installed in a ship.

Further, in the practice of the present invention, the engine attitude detecting means may be directly arranged on the engine body.

Further, in the practice of the present invention, when setting the increase / decrease in the fuel supply amount based on the change in the engine attitude, for example, the submersion level of the underwater exhaust port of the outboard motor becomes shallow as the propulsion unit trims up, and When the back pressure becomes low and the intake air amount to the engine increases, it is possible to add a consideration to increase the fuel amount in order to supply a larger amount of fuel corresponding to the increase in the intake air amount.

[Advantages of the Invention] As described above, according to the present invention, the fuel supply amount to the engine is controlled by the fuel supply amount control means based on the detection result of the engine attitude detection means so that the optimum fuel amount for the operating state of the engine is obtained. It is automatically increased or decreased to secure the supply status.

That is, for example, when the combustion chamber is located higher than the fuel supply source due to a change in the attitude of the engine, the resistance of gravity acting on the flow of fuel from the fuel supply source to the combustion chamber is caused by the resistance of gravity. The fuel supply is increased so as to offset the fuel decrease trend. On the other hand, in the case where the combustion chamber is located lower than the fuel supply source, the increasing tendency of the fuel due to the addition of gravity acting on the fuel flow from the fuel supply source to the combustion chamber is offset. Thus, the fuel supply is reduced.

Therefore, according to the present invention, the amount of fuel supplied to the engine can be automatically increased / decreased according to the change in the attitude of the engine, and the optimal fuel supply state for the operating state of the engine can be secured.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a schematic diagram showing an example of a vaporizer used for carrying out the present invention,
FIG. 3 is a schematic diagram showing an outboard motor to which the present invention is applied, and FIG.
(A) to (C) are flow charts showing the control state in one embodiment of the present invention. 10 ... Outboard motor, 11 ... Ship, 17 ... Engine, 32 ... Trim angle sensor (engine attitude detecting means), 41 ... CP
U (fuel supply amount control means).

Claims (1)

[Claims] 1. A fuel supply device for a marine vessel propulsion engine installed and used on a ship, the engine attitude detecting means detecting an attitude change of the engine, and the fuel supplying to the engine based on the detection result of the engine attitude detecting means. A fuel supply device for a marine vessel propulsion engine, comprising a fuel supply amount control means for adjusting the amount.