JPS60113030A - Valve gear system driving device in vertical shaft type diesel engine for outboard motor - Google Patents

Abstract

PURPOSE:To prevent a flywheel from shooting out and thereby promote safety for an operator, by installing a pulley for cam shaft driving use in a lower end part of the cam shaft of a valve gear system driving device, while driving a unit injector or a fuel-in-jection pump and each of suction drain valves through the said pulley. CONSTITUTION:In time of driving a cam shaft 12 of a Diesel engine 2 by a crankshaft 6 via a timing belt, a pulley 13 stretching over this timing belt 17 is installed in a lower end part of the cam shaft 12, namely, at the opposite side to a flywheel. On the over hand, this timing belt 17 is installed in the left side alone in a forward direction A of a cylinder center of the Diesel engine 2, avoiding an oil pan 16 situated in a position shown in broken lines, however, it will do that a tensioner 18 may be installed in the right side in the forward direction a and that another timing belt 17' may also be installed so as to describe a large circle around the oil pan 16 as shown in two-dot chain lines. Accordingly, protrusion to the upside of the flywheel will in no case occur so that such an accident that one's hand is caught by the timing belt is preventable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a valve train drive system for a vertical shaft Tessel engine for an outboard motor, which is mainly mounted on a small boat.

[Prior art]

Vertical shaft diesel engines, where the crankshaft is the axle,
Generally used as a gate for outboard motors]S, the first
An example of this will be explained with a schematic side view of the figure.
The outboard motor attached to the stern 1 of a small boat consists of a tea cell engine 2 and a dry drive unit 6. The tea cell engine 2 rotates a propeller screw 4 provided at the bottom of the drive unit B, and the small boat moves in the direction of arrow A. In addition to propelling the outboard motor in the direction of travel, the outboard motor is steered by moving the IFe handle 5 protruding from the front side to the left and right of the boat.

In this Tee cell engine, the crankshaft 6 is a vertical axis, so the piston 70 (d: 7k) slides flatly, and the unit injector 8 is opposed to the combustion engine on the side of the piston 70. /It is attached to the cylinder head 9, and the combustion caused by the fuel injection from this unit injector 8 causes the screw I.77 to reciprocate in the horizontal direction, thereby rotating the crankshaft 6 installed in the vertical direction. .

Further, as shown in FIG. 2, which is an enlarged side cross-sectional view of FIG.
A pulley 16 provided at the upper end of the camshaft 12 is driven by the crankshaft 6 via a timing belt 17.

Note that a flywheel 11 is provided at the top end of the crankshaft 6;
A dynamo 14 for power generation is provided, and this dynamo 14
It is desirable to provide a recoil starter 1 at the top of the chasel engine 2, and furthermore, a recoil starter 1 at the top of the flywheel 11.
5, it is desirable that this flywheel 11 be in the second position when pulling the blade from the outside.

On the other hand, in engines that require high-speed rotation, such as the diesel engine 2 for outboard motors, the camshaft 12 for driving the intake and exhaust valves 1o is usually of an overhead type.
Since it is necessary to bring the cylinder head 2 to the cylinder head 9, using the timing held 17 for driving it is currently considered the most efficient method.

In this way, the timing belt 17 is connected to the flywheel 1.
The advantage of having the timing belt 17 at the top directly below the oil pan is that it is easy to take out, and since the timing belt 17 cannot be used in oil, it can be placed far away from the oil pan. In addition to the disadvantage that the flywheel 11 is exposed and easily damaged or damaged, by placing the flywheel 11 above the timing held 17, the middle length of the crankshaft 6 becomes longer, and the flywheel 11 There is a risk that it will protrude to the top and become unbalanced, and there is still a risk that the worker's hand may get caught.

[Purpose of the invention]

Therefore, the present invention eliminates the above-mentioned drawbacks of the conventional technology, and eliminates the upward protrusion of the flywheel of a vertical shaft type engine that drives an overhead cam type camshaft via a timing held, thereby eliminating unbalance. In addition to reducing
The purpose is to protect the timing held and ensure the safety of workers.

[Structure of the invention]

That is, the valve train drive device of the present invention is a unit injector! In vertical shaft Tee Cell engines for outboard motors, in which a pulley is provided on the camshaft that drives the fuel injection pump and intake/exhaust valve, and the pulley is driven by the crankshaft via a timing belt, the camshaft drive described above is used. The camshaft is constructed by providing a pulley for use at the lower end of the camshaft.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a side sectional view of a vertical shaft type diesel engine for an outboard motor according to an embodiment of the present invention, and FIG. FIG.

First, the above-mentioned diesel engine 2 has a vertical rank axis 6 like the conventional example shown in Fig. 1, and has almost the same configuration and function as shown in Fig. 1, and the same parts have the same part numbers. It is shown in

Therefore, in the present invention, when the camshaft 12 is driven by the crankshaft 6 via the timing belt 17, as shown in FIG. 11
It is located on the opposite side.

Further, as shown in FIG. 4, this timing belt 17 is provided almost only on one side, that is, on the left side in the traveling direction A, with respect to the /s/da center of this tea cell engine 2. Oil pan 16 located at the position indicated by the broken line
However, as shown by the two-dot chain line in Figure 3,
/ The yonner 18 may be provided on the right side in the direction of travel A, and the timing heald 17' may be provided so as to form a large ring around the oil pan 16 as shown by the two-dot chain line.

[Function] As described above, in the present invention, the timing belt 17 is placed on the lower side opposite to the flywheel 11, so compared to the conventional example shown in FIG. 2, it is inconvenient to replace the timing belt 17. In recent years, the quality of the timing belt 17 has improved and its life has become longer, and its life has been extended to the same extent as the overhaul period of the diesel engine 2, which makes it possible to apply the present invention. It is.

In addition, in the valve train drive device of this embodiment, a camshaft 12 is provided with a pulley 16 of a timing belt 17 at its lower end.
A governor device 19 is provided at the upper end, and a control rod 20 for adjusting the increase/decrease of the fuel injection amount of the unit injector 8 is operated by the governor device 19. By removing the cowling 21 of the outer engine, these governor devices 19 can be easily adjusted.

Although this embodiment shows a diesel engine 2 provided with a unit injector 8, the present invention can be similarly applied to a diesel engine provided with a fuel injection valve and a fuel injection pump separately.

〔Effect of the invention〕

Therefore, in a vertical shaft diesel engine for an outboard motor to which the valve train drive system of the present invention is applied, the flywheel provided at the upper end of the crankshaft does not protrude upward, and the imbalance is eliminated. At the same time, it is possible to prevent damage to the timing belt and accidents such as getting your hand caught in the timing belt.

[Brief explanation of drawings]

Fig. 1 is a schematic side view of a conventional outboard motor, Fig. 2 is an enlarged side sectional view of the Tee cell engine shown in Fig. 1, and Fig. 3 is a vertical shaft type diesel engine for an outboard motor according to an embodiment of the present invention. 4 is a side sectional view of FIG. 3, and FIG. 4 is a plan sectional view of FIG. 2. Tessel engine, 8. Unit injector,
10... Intake and exhaust valve, 12. Camshaft, 1 Ro... Pulley, 1
7, 17'...Taimi/Gubel l-1 agent Patent attorney Nobuo Ogawa - Patent attorney Ken Noguchi Teru Patent attorney Kazuhiko Shinshita

Claims (1)

[Claims] Cam ``tql+'' that drives the unit injector or fuel injection pump and cam 11111 that drives the intake and exhaust valves
In a vertical type 1 diesel engine for a boat (vehicle) in which a pulley is provided on the camshaft and the pulley is driven by the crankshaft via a timing belt, the bobber for driving the camshaft is attached to the lower end of the camshaft. A valve train drive device for a vertical shaft tea cell engine for an outboard motor, characterized by the following: