JPH10246136A - Control device for ship engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent engine stalling surely by carrying out control so as to turn off an alternator in the case where engine rotation is rapidly decelerated or gear shift is performed. SOLUTION: In an engine 6 of an outboard motor 1, an fuel injection rate and an injection timing of a fuel injection valve 40 and an ignition timing of an ignition plug 25 are controlled on the basis of an operation control map which is beforehand stored from detecting values from an engine speed sensor 43, an intake pressure sensor 44, a throttle opening sensor 52, and the like by a control unit 42. A rotor coil of an alternator 49 is driven by means of rotation of the crank-shaft 20 of the engine 6. In the case where the alternator 49 is controlled, it is judged by a lever speed sensor 57 or a hull speed sensor whether rapid deceleration is carried out or not, and also it is judged by a shift position sensor 55 whether a shift position is a neutral position or not. When the rapid deceleration is carried out and the shift position is changed from the neutral position, the alternator 49 is turned off, and an idling rotation is raised so as to avoid engine stalling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a control system for a marine engine.

[0002]

2. Description of the Related Art For example, in a small boat equipped with an outboard motor, a shift position is switched between forward, neutral and reverse by turning an operation lever, and the operation lever is further rotated from a forward position and a reverse position. The throttle valve opening is adjusted by moving the throttle valve. In such a small boat, when braking during forward running, the throttle valve is closed, the shift position is switched from forward to reverse, and the propeller is reversed to generate reverse thrust and decelerate. .

[0003]

However, during rapid deceleration from the above-mentioned forward running, the hull is moving forward by the inertial force, so that the engine is rotated from the propeller side to be in an engine braking state. As a result, the intake negative pressure increases due to the rapid closing of the throttle valve, and the air-fuel mixture becomes over-rich due to the influence of the wall film flow of the fuel in the intake pipe.As a result, the combustion deteriorates. If this is done, there is a problem in that a force for reverse rotation of the engine is applied from the propeller side to cause engine stall.

In order to solve this problem, Japanese Utility Model Laid-Open Publication No. 3-21
In Japanese Patent Application Laid-Open No. 551, an additional mechanism is provided so that the throttle valve closes gradually when the throttle is suddenly closed, but the response is not sufficient and engine stall cannot be reliably prevented. In addition, there is a problem that the structure of the additional mechanism is complicated and the cost increases.

[0005] The present invention solves the above-mentioned problem, and is intended for use in a case where a shift change is performed after sudden deceleration of an engine.
An object of the present invention is to provide a control device for a marine engine that can reliably prevent engine stall with a simple configuration.

[0006]

According to a first aspect of the present invention, there is provided an alternator driven by an engine, and a shift position is switched between forward, neutral, and reverse by an operation lever. In the marine engine control device as described above, the alternator is turned off when the engine speed suddenly decelerates or there is a shift change. The invention according to claim 2 is the invention according to claim 1, wherein According to a third aspect of the present invention, the engine is a four-stroke engine.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an example of an outboard motor as a small boat to which the present invention is applied. FIG. 1 is a schematic view showing the entire configuration of the outboard motor, and FIG. 2 is a schematic side view of an engine unit in FIG. FIG. 3 is a diagram for explaining the shift position of the operation lever, and FIG. 4 is a diagram showing characteristics of the shift position sensor.

In FIG. 1, an outboard motor 1 is pivotally supported on a stern 2a of a hull 2 via a clamp bracket 3 so as to be able to swing up, down, left and right. The outboard motor 1 has a schematic structure in which an engine 6 is mounted on a lower case 5 in which a propulsion device 4 is disposed, and the engine 6 is surrounded by a cowling 7 (FIG. 2).

The propulsion unit 4 has a propulsion shaft 1 at a lower end of a drive shaft 8 extending in a vertical direction via a bevel gear mechanism 10.
1 and a propeller 12 is connected to the rear end of the propulsion shaft 11. The bevel gear mechanism 10 includes a drive bevel gear 10a mounted on the drive shaft 8, a forward bevel gear 10b rotatably mounted on the propulsion shaft 11, and meshed with the drive bevel gear 10a, and a reverse bevel gear 10c.

The propulsion device 4 is provided with a forward / reverse switching device 15. This switching device 15 connects a shift rod 18b via a shift cable 18a to an operation lever 16 pivotally supported in a swingable manner in the front-rear direction.
Any one of the front and rear bevel gears 10b and 10c is connected to the propulsion shaft 11 by a dog clutch 18c connected to the propulsion shaft 8b.
Or, they are configured not to be combined. Also,
By turning the operation lever 16 to a predetermined opening degree or more, the throttle actuator 45
Is configured to open and close. Reference numeral 52 denotes a throttle opening sensor.

As shown in FIG. 3, the operation lever 16 is driven by a dog clutch 18c to move the front and rear bevel gears 10 together.
b and 10c are both in a neutral position (region) A with respect to the propulsion shaft 11 and in a forward clutch-in position B1 in which the forward bevel gear 10b is coupled to the propulsion shaft 11 by being rotated further forward from the neutral position A. By rotating the throttle valve 17 further forward from the forward clutch-in position B1, the throttle valve 17 is rotated between a forward travel position (region) B2 that opens according to the amount of rotation. A reverse clutch-in position C1 in which the reverse bevel gear 10c is coupled to the propulsion shaft 11 by rotating backward from the neutral position A, and a throttle valve by further rotating backward from the reverse clutch-in position C1. 17 is rotated between a reverse traveling position (area) C2 that opens according to the amount of rotation.

The engine 6 is a water-cooled, four-cycle, four-cylinder engine, in which a crankshaft 20 is arranged vertically so as to be substantially vertical when traveling. The upper end of the shaft 8 is connected. The engine 6 has a structure in which a piston 22 is inserted and arranged in a cylinder bore 21 a formed in a cylinder block 21, and the piston 22 is connected to a crankshaft 20 by a connecting rod 23. As shown in FIG. 2, the cylinder head 24 is fastened to the rear mating surface of the cylinder block 21 as viewed in the hull longitudinal direction of the cylinder block 21, and the crankcase 34 that accommodates the crankshaft 20 is fastened to the front mating surface.

A flywheel 60 and a driving pulley 61 are fixed to an upper portion of the crankshaft 20. A driven pulley 62 is fixed above the rotating shaft 49 a of the alternator 49, and a belt 63 is stretched between the driving pulley 61 and the driven pulley 62, so that the rotation of the crankshaft 20 drives the rotor coil of the alternator 49. I have to.

Cylinder bore 21a and cylinder head 2
The ignition plug 25 is mounted in the combustion chamber 24a for each cylinder formed in FIG. An exhaust valve 28 and an intake valve 29 are disposed at an exhaust port 26 and an intake port 27 communicating with each combustion chamber 24a, respectively. These valves 28 and 29 are disposed in parallel with the crankshaft 20. The camshafts 30 and 31 are driven to open and close. In addition,
25a is an ignition coil, 25b is an igniter. An exhaust manifold 32 is connected to the exhaust port 26, and exhaust gas is discharged from the rear end of the propulsion device 4 from the exhaust manifold 32 through the lower case 5.

Each intake port 27 has an intake manifold 3
3 are connected. Each intake manifold 33 is connected to a junction 35 disposed on the side of the oil pan 34a of the crankcase 34. The junction 35 includes a throttle body 3 having a throttle valve 17 common to each cylinder.
6 are connected. The throttle body 36 is connected to a surge tank 37 provided behind the oil pan 34a. An intake duct 38 is connected to the surge tank 37, and the intake duct 38 is disposed above the engine 6. An air inlet 38a is formed in the intake duct 38, and air is taken in from an outside air inlet 7a formed in the rear wall of the cowling 7 (see an arrow in FIG. 2).

A fuel injection valve 40 is inserted into a desired portion of each of the intake ports 27 of the cylinder head 24, and an injection port of the fuel injection valve 40 is directed toward an opening of the intake port 27. Each fuel injection valve 40 has a crankshaft 20
Supply rail 4 that is arranged in parallel with and supplies pressurized fuel
The fuel supply rail 41 is connected to a vapor separator tank (not shown).

The engine 6 has a control unit 42 as an operation control device. The control unit 42 receives detection values from an engine speed sensor 43, an intake pressure sensor 44, a throttle opening sensor 52, a coolant temperature sensor 46, a hull speed sensor 47, a cylinder discriminating sensor 48, and a throttle opening sensor 52. The fuel injection amount of the fuel injection valve 40, the injection timing, and the ignition timing of the ignition plug 25 are controlled based on the operation control map stored in advance from these detected values.

The shift rod 18b of the switching device 15 is provided with a shift position sensor 55. The shift position sensor 55 is connected to the shift rod 18b.
, That is, the shift position (forward, neutral, reverse) of the operating lever, and outputs a voltage value proportional to the shift position to the control unit 42 as shown in FIG. Opens and closes the throttle valve 17. Operation lever 1
6 is provided with a lever speed sensor 57 for detecting the rotation speed, and outputs a detection value from the sensor to the control unit 42.

5 and 6 show an embodiment of the control device according to the present invention. FIG. 5 is a diagram showing a processing flow, and FIG. 6 is a diagram for explaining a control method.

In FIG. 5, first, at step S1, it is determined whether or not rapid deceleration is performed by the lever speed sensor 57 or the hull speed sensor 47.
5, it is determined whether or not the vehicle is in the neutral position. If the vehicle is suddenly decelerated and the vehicle is in the neutral position, it is determined in step S2 whether or not there has been a shift change (reverse or forward from neutral). Turn 49 off. Thereafter, after a predetermined time has elapsed in step S4, control is performed so that the load on the alternator 49 is gradually increased. The determination in step S4 may determine that the engine speed has become equal to or greater than a predetermined value.

Normally, the alternator is always turned on when the engine is driven to energize the rotor coil. However, in the present invention, as shown in FIG. (E.g., 1,000 rpm). When a shift change is detected, the alternator is turned off and the alternator is set to no load, so that the idling speed rises to b (e.g., 1,500 rpm), and engine stall can be avoided. .

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above embodiment, the alternator is turned off when the engine rotation is rapidly decelerated and there is a shift change, but the alternator is turned off when the engine rotation is suddenly decelerated or there is a shift change. You may. Further, in the above embodiment, an example in which the invention is applied to a four-cycle engine is described. However, it is needless to say that the invention may be applied to a two-cycle engine.

[0023]

As is apparent from the above description, according to the first aspect of the present invention, the alternator is turned off when the engine speed suddenly decelerates or there is a shift change. Can be prevented.

According to the second aspect of the invention, it is particularly effective when the shift change is from neutral to reverse, and according to the third aspect of the invention, when the invention is applied to a four-cycle engine. It is effective.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a control system showing a first embodiment of a fuel injection control device for an internal combustion engine of the present invention.

FIG. 2 is a configuration diagram of fuel injection control that is arithmetically processed by the control device of FIG. 1;

FIG. 3 is a diagram for explaining a shift position of an operation lever.

FIG. 4 is a diagram illustrating characteristics of a shift position sensor.

FIG. 5 is a diagram showing a flow of processing showing an embodiment of a control device according to the present invention.

FIG. 6 is a diagram for explaining a control method.

[Explanation of symbols]

6 engine, 15 switching device, 16 operating lever, 4
9 Alternator 55 Shift position sensor 57 Lever speed sensor

Claims (3)

[Claims] 1. A marine engine control device comprising an alternator driven by an engine, wherein a shift position is switched between forward, neutral, and reverse by an operation lever. A marine engine control device characterized in that the alternator is turned off in the event of occurrence. 2. The marine engine control device according to claim 1, wherein the shift change is from neutral to reverse. 3. The control system for a marine engine according to claim 1, wherein said engine is a four-stroke engine.