JP2000265931A - Ignition timing control mechanism of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of knocking in starting an engine at a low cost and with a simple structure, in an engine for mechanically interlocking control of the ignition timing with the throttle opening and closing operation. SOLUTION: In an engine, control of the ignition timing is performed while being mechanically interlocked with the throttle opening and closing operation, and a shift mechanism is moved by the operation of a shift operation lever 9 through a shift connection lever 22. A spark advance lever 27 for interlocking the throttle opening and closing operation with the control of the ignition timing is coaxially provided in relation to a throttle opening and closing accelerator cam 24 to be rotated by the accelerator operation so as to follow the accelerator cam by specified connecting force through a spring only by the specified range, and a stopper 32 abuttabe on the shift connection lever 22 in the neutral state is integrally provided with the spark advance lever 27 so as to limit following of the spark advance lever 27 in relation to the rotation of the accelerator cam 24 against connecting force between the stopper and the accelerator cam 24 when the shift mechanism opens a throttle in the neutral state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine in which ignition timing control is mechanically linked with a throttle opening / closing operation, and more particularly, to preventing occurrence of kicking at the time of starting in such an engine. The ignition timing control structure.

[0002]

2. Description of the Related Art As an outboard motor engine mounted on an outboard motor of a small boat, the start of the engine is manually performed by a manual starter, and the ignition timing is mechanically linked with the operation for opening and closing a throttle. Control is performed, and a shift mechanism for switching transmission of engine power between neutral, forward and reverse is manually operated via a shift lever (shift operation lever) through each connecting member such as a shift connecting lever. Such engines are commonly used in the past.

[0003]

By the way, in the above-described engine, when the engine is manually started by a manual starter, the throttle is fully opened in order to reduce the intake resistance and reduce the burden of the starting operation. In such a case, the engine may be started in such a state.In such a case, the ignition timing control is mechanically linked with the operation for opening and closing the throttle, so that the accelerator operation for fully opening the throttle is performed. The ignition is advanced.

[0004] As a result, the ignition timing is advanced in spite of the fact that the power for rotating the engine for manual start is low, and the ignition is started before the piston rises to the top dead center. A so-called "ketch" in which the engine is rotated backward by being pushed back may occur.

[0005] Incidentally, a technique for preventing the occurrence of clicks at the time of starting the engine is conventionally known, for example, from JP-A-5-60044 and JP-A-7-259711. In any of such conventionally known anti-ketchin structures, since the ignition timing is electrically controlled using a microcomputer, the cost is high.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems. More specifically, in an engine in which ignition timing control is mechanically linked with a throttle opening / closing operation, a simple method is used. It is an object of the present invention to prevent the occurrence of kicking at the time of starting an engine at a low cost by a structure.

[0007]

According to the present invention, in order to solve the above-mentioned problems, the ignition timing is controlled mechanically in conjunction with a throttle opening / closing operation, and the shift connection is operated by operating a shift operation lever. In an engine in which the shift mechanism is moved via the lever, an advance lever for linking the throttle opening / closing operation and the control of the ignition timing is provided.
The throttle opening and closing accelerator cam which is rotated by the accelerator operation is provided coaxially so as to follow a predetermined range with a predetermined coupling force via a spring force, and the throttle mechanism is operated in a neutral state so that the throttle is opened. When opening, a stopper capable of contacting the shift connection lever in the neutral state, so as to limit the follow-up of the advance lever to the rotation of the accelerator cam against the connection force between the accelerator cam and It is provided integrally with the advance lever.

According to such a configuration, when the engine is started with the shift being neutral and the throttle being fully opened, even if the accelerator cam is rotated so that the throttle is fully opened by operating the accelerator, the advance lever is not moved. When the integrally provided stopper abuts on the shift connection lever in the neutral state, the rotation of the advance lever that follows the rotation of the accelerator cam is suppressed by the shift connection lever, and the advance of ignition is reduced. Since the ignition timing is suppressed so that the ignition timing cannot be advanced, even if the engine rotational force at the time of starting is low, no kicking occurs.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an engine ignition timing control structure according to the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an outboard motor equipped with an engine having an ignition timing control structure according to the present invention. The outboard motor 1 has a top cowl 2, an upper case 3, a lower case An engine 5 serving as a drive source is housed in the top cowl 2, a steering handle 6 is connected to the upper case 3 via a steering bracket 7, and a propeller 8 serving as a propulsion device is provided in a lower case. A shift operation lever 9 mounted on the rear side of the steering wheel 4 and near the steering handle of the steering bracket 7 for manually performing shift switching is provided.

The engine 5 housed in the top cowl 2 of the outboard motor 1 is installed so that the axis of its crankshaft (not shown) is oriented vertically, and the upper end of the crankshaft of the engine 5 A manual starter 10 for starting the engine by a manual operation of a driver is connected to the side, and a drive shaft 11 for power transmission is connected to a lower end of the crankshaft of the engine 5.

A drive shaft 11 connected to the lower end of the crankshaft of the engine 5 extends vertically through the upper case 3 to the lower case 4, and the lower end of the drive shaft 11 is connected to a shift mechanism 12 using a bevel gear. The rotation of the crankshaft driven by the engine 5 is transmitted to the propeller 8 disposed on the rear side of the lower case 4 via the drive shaft 11, the shift mechanism 12, and the propeller shaft 13 in cooperation with the propeller shaft 13. You.

Although not shown in detail, the shift mechanism 12 engages a forward gear and a reverse gear rotatably provided on the propeller shaft 13 with a drive gear fixed to the lower end of the drive shaft 11, respectively. Shifting the dog clutch, which is spline-engaged on the propeller shaft 13 between the gear and the reverse gear, to neutral, forward or reverse by rotating a shift cam provided at the lower end of the shift rod 14. Thus, the rotation of the drive shaft 11 is transmitted to the propeller shaft 13 either forward or backward, or is not transmitted as neutral.

The shift rod 14 is mounted on the drive shaft 1
In a state substantially parallel to 1, the steering cowl is rotatably housed inside the outer cylindrical member integrally fixed to the swivel bracket 17 from the top cowl 2, and the upper end thereof is integrally connected to the steering bracket 7. ) Extends vertically to the lower case 4 through the hollow shaft core, and the upper end of the shift rod 14 is linked to the shift operating lever 9 via each connecting member. By manually operating the shift operation lever 9, the shift rod 14 is rotated about its axis through the respective connecting members.

The outboard motor 1 has a clamp bracket 16 which is detachably fixed to the tail plate 15 of the hull.
The swivel bracket 17 is rotatably connected in the vertical direction by a horizontal tilt shaft 18, and the outboard motor 1 is supported by the swivel bracket 17 so as to be rotatable in the left and right direction (ie, the outboard extending in the vertical direction). The steering shaft of the machine is rotatably housed inside an outer cylindrical member integrally fixed to the swivel bracket 17 and the upper end thereof is integrally connected to the steering bracket 7 so as to be vertically ( It is attached to the rear plate 15 of the hull so as to be rotatable in both the tilt direction) and the left and right direction (steering direction).

FIGS. 2 to 6 show a connecting member between the shift operating lever 9 and the shift rod 14 as one of the constituent members for controlling the ignition timing of the engine 5 of the outboard motor 1 as described above. FIG. 3 shows different throttle opening states in the neutral and forward shifts for the engine ignition timing control structure of the present embodiment.

As shown in FIG. 2, the shift operation lever 9 is linked to the upper end of the shift rod 14 via a shift connection rod 21 and a shift connection lever 22 for the driver to manually perform a shift operation. The shift connecting rod 21 is rotated by operating the shift operation lever 9 and the shift connecting lever 22 is rotated by moving the shift connecting rod 21, thereby rotating the shift rod 14.

At a position above a shift connecting lever 22 for interlocking the shift operating lever 9 and the shift rod 14, a throttle opening / closing pivoted via an accelerator wire 23 by operating an accelerator operating section provided on a steering wheel. Accelerator cam 24, a pickup unit 25 of an advancing device for controlling ignition timing, and a connecting arm 26
The advancing lever 27 movably connected via a .gamma. Is provided coaxially so as to be rotatable with respect to a common base member 28 fixed at a fixed position.

The accelerator cam 24 and the advancing lever 27, which are relatively rotatable and provided coaxially, are not shown, but one end of a coil spring arranged concentrically with the rotation shaft is connected to the accelerator cam. 24, and the other end is fixed to the rotating base 29 of the advancing lever 27, so that a predetermined force is applied through the torsion direction spring force of the coil spring. It is linked so that it can be linked with the connecting force.

The stopper levers 28a and 28b formed on the base member 28 for restricting the rotation of the lead lever 27 to a predetermined range are used.
The stopper 3 integrally fixed to the turning base 29 of the
0 and a stopper 31 that can be adjusted by a screw are provided integrally with each other, and further, an advance angle with respect to the rotation of the accelerator cam 24 in the neutral state so as to abut on the shift connection lever 22 in the neutral state. 3 for restricting the following of the lever 27
2 are provided integrally.

The operation of the ignition timing control structure of the engine according to the present embodiment having the above-described structure will be described below with reference to FIGS.

In a state in which the shift is advanced (F) by operating the shift operation lever 9, as shown in FIGS.
Regardless of how the shift connecting lever 22 is tilted forward and the advance lever 27 is turned, the stopper 32 integrally provided on the turning base 29 does not contact the shift connecting lever 22. It has become. Even when the shift is set to reverse (R), only the direction in which the shift connecting lever 22 falls is reversed, and the relationship between the stopper 32 and the shift connecting lever 22 is the same as that when the shift is set to forward (F). is there.

In such a state other than neutral,
When the accelerator cam 24 is rotated via the accelerator wire 23 by the accelerator operation, the shift connecting lever 22
Regardless of the rotation angle of the accelerator cam 24 for opening and closing the throttle valve 33, the advance lever 2
7 are stopper stoppers 2 formed on the base member 28.
Rotation following the rotation of the accelerator cam 24 in a predetermined rotation range regulated by the stoppers 30, 31 provided on the rotation base 29 of the advance lever 27. Becomes

That is, when the throttle is closed, FIG.
As shown in the figure, the stopper receiving portion 28 on the base member 28 side
b and the stopper 31 on the advance lever 27 side abut against each other, thereby preventing the rotation of the advance lever 27 in the counterclockwise direction, and the stopper 30 on the advance lever 27 side prevents the accelerator cam 24 from rotating. Since the rotation in the counterclockwise direction is prevented, the advance lever 27 and the accelerator cam 24 are prevented from rotating.
Is stopped at a fixed initial position with respect to the base member 28, which is adjusted by a stopper 31 which can be adjusted with a screw.

When the accelerator is operated so as to open the throttle from the closed state, the accelerator cam 24 and the advance lever 27 are connected to each other by a coil spring interposed therebetween, as shown in FIG. Thus, the stopper receiving portion 28a on the base member 28 side and the advance lever 27
Until the stopper 30 on the side contacts the accelerator cam 24.
The advancing lever 27 follows the rotation of the engine, and the advancing lever 27 rotates until the throttle valve 33 reaches a predetermined opening degree (partial state), so that the ignition timing is suitable for the operating state of the engine. Advanced ignition timing (advanced by θ1-θ2)
Is done.

Further, when the accelerator is operated so that the throttle is fully opened from the partial state, as shown in FIG. 6, the stopper receiving portion 28a on the base member 28 and the stopper 30 on the advance lever 27 are connected. By contact
The advance lever 27 does not rotate clockwise any further.
While the advance angle (θ1−θ2) of the ignition timing does not advance any more, the accelerator cam 24 rotated via the accelerator wire 23 is interposed between the accelerator cam 24 and the advance lever 27. The throttle valve 33 rotates to a position where the throttle valve 33 is fully opened against the spring force of the coil spring.

In the state where the shift is set to neutral as compared to the state where the shift is set to forward (F), as shown in FIGS. 2 and 3, the shift connecting lever 22 is in an upright state. Thus, when the accelerator is operated to open the throttle from the closed state, the rotation of the advance lever 27 that follows the accelerator cam 24 that is rotated via the accelerator wire 23, When the stopper 32 provided integrally with the rotation base 29 of the lever 27 abuts on the shift connection lever 22,
The advance is only slightly advanced (θ1−θ3), and it is regulated so as not to reach the set advance position (θ1−θ2) when the throttle is fully opened.

That is, when the throttle is closed, FIG.
As shown in the figure, the advance lever 27 and the accelerator cam 24
Is similar to the case where the shift is forward (F),
8 is stopped at a fixed initial position, but when the accelerator is operated to open the throttle from such a closed state, as shown in FIG. Part 28a and advance lever 2
When the stopper 30 on the side of the advancing lever 27 is not in contact with the stopper 30 on the side of the
Abut.

Then, at that time, the accelerator cam 2
The rotation of the advance lever 27 following the rotation of the accelerator cam 24 is prevented by the shift connection lever 22 against the spring force of the coil spring interposed between the lever 4 and the advance lever 27. In other words, even if the accelerator operation is performed from such a state until the throttle is fully opened, only the accelerator cam 24 rotates and the throttle is fully opened.
Regarding the ignition timing, the advance position (θ1-θ) where the rotation of the advance lever 27 is stopped by the shift connection lever 22
3) I will not go any further.

According to the ignition timing control structure of the engine according to the present embodiment, which operates as described above, a simple structure is provided in which the stopper 32 for contacting the advance lever 27 with the shift connection lever 22 is provided. In the case where the engine 5 is started with the throttle fully opened just by adding the throttle lever 24, even if the accelerator cam 24 is rotated by the accelerator operation, if the shift is in the neutral state, the advance lever 27
The stopper 32 provided integrally with the shift lever 22 abuts on the shift connecting lever 22, whereby the rotation of the advance lever 27 that follows the rotation of the accelerator cam 24 is suppressed, and as a result,
Since the advance of the ignition is suppressed and the ignition timing cannot be advanced, even if the engine rotational force at the time of starting is low, no kicking occurs.

The embodiment of the ignition timing control structure of the engine according to the present invention has been described above. However, the present invention is not limited only to the above-described embodiment. The outboard engine is an engine for an outboard motor, but the present invention can also be applied to an engine other than an outboard motor, and the engine shown in the above embodiment uses a manual starter as an engine starter. However, it is needless to say that the present invention can be appropriately changed, for example, the present invention can be applied to an engine using an electric starter.

[0032]

According to the ignition timing control structure for an engine of the present invention as described above, even if the engine is started with the throttle fully open, it is possible to prevent the occurrence of clicks at the time of starting. The control of the ignition timing for preventing the kicking can be carried out at a low cost with an extremely simple structure.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an outboard motor equipped with an engine having an ignition timing control structure according to the present invention.

FIG. 2 is a side view showing one embodiment of the engine ignition timing control structure of the present invention in a state where the shift is neutral and the throttle is closed.

FIG. 3 is a side view of the engine ignition timing control structure shown in FIG. 2, showing a state in which a shift is neutral and a throttle is fully open.

FIG. 4 is a side view showing the ignition timing control structure of the engine shown in FIG. 2, showing a state where the shift is forward (F) and the throttle is closed.

FIG. 5 is a side view showing a state in which a shift is forward (F) and a throttle is partial in the engine ignition timing control structure shown in FIG. 2;

FIG. 6 is a side view showing the ignition timing control structure of the engine shown in FIG. 2, showing a state where the shift is forward (F) and the throttle is fully open.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outboard motor 5 Engine 9 Shift operation lever 10 Manual starter 12 Shift mechanism 22 Shift connection lever 24 Accel cam 27 Advance lever 32 Stopper (which contacts the shift connection lever) Stopper 33 Throttle valve

Claims (2)

[Claims] In an engine in which ignition timing is controlled in mechanical linkage with a throttle opening / closing operation, and a shift mechanism is moved via a shift connection lever by operating a shift operation lever, the throttle opening / closing operation and ignition are performed. The advance lever for interlocking the timing control is coaxial so that it follows the accelerator cam for opening and closing the throttle, which is rotated by the accelerator operation, by a predetermined coupling force via a spring force within a predetermined range. When the shift mechanism opens the throttle in a neutral state, the shift mechanism restricts the follow-up of the advance lever to the rotation of the accelerator cam against the coupling force between the accelerator mechanism and the accelerator cam. An engine, characterized in that a stopper capable of contacting the shift connection lever in a neutral state is provided integrally with the advance lever. Ignition timing control structure. 2. The ignition timing control structure for an engine according to claim 1, wherein the starter for starting the engine is a manual starter operated manually.