JPS59100093A - Apparatus for preventing air temperature rise inside cowling in outboard engine - Google Patents

Abstract

PURPOSE:To improve the output performance of an engine by installing covers for collecting and dicharging the hot air in a cowling and preventing the rise of the air temperature in the cowling. CONSTITUTION:Because of the circulation of lubricating oil, heat irradiation occurs at each upper part of a crank shaft 22 and a cam shaft 27, and on a flamag 34, etc., and hot air is confined. The upper and the lower collecting covers 54 and 51 collect the hot air and discharge outside through a discharge passage 55, exhaust port 49, and a discharge passage 47 by the revolution of a ring gear 34A. Since the hot air is not confined in a cowling, the density of the intake air in an engine 13 is not reduced, and the output performance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing a rise in temperature inside a cowling in an outboard motor.

Outboard motors are used in the sea or on the surface of the water, so in order to prevent problems caused by seawater, etc. covering the internal combustion engine, the internal combustion engine is housed in a cowling, and the air introduced into the cowling is used to prevent internal combustion. It is used as combustion air for engines.

However, the cowling of the above-mentioned outboard motor accommodates the internal combustion engine having a heat dissipating portion under conditions that allow it to be shaped to prevent water droplets from entering even in bad environments such as rain and waves. ing.

Therefore, in such an outboard motor, the temperature of the combustion air introduced into the cowling increases due to the influence of the heat radiation part F, and high-density combustion air is not supplied to the internal combustion engine. , it becomes difficult to improve the output performance.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus for preventing a rise in air temperature inside a cowling in an outboard motor, which can prevent the intake air temperature inside the cowling from rising and improve the output performance of the engine.

In order to achieve the above object, the present invention provides a collection cover in a cowling that collects air around a heat dissipation part of an internal combustion engine, and an exhaust L provided in the cowling to collect the air abstracted in the collection cover. From Ko to H1t [Jul] It was nine to make you feel like it.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a top view showing an outboard motor to which an embodiment of the present invention is applied, FIG. 2 is a cross-sectional view taken along line ii-n in FIG. 1, and FIG. 3 is a cross-sectional view of FIG. It is a sectional view along the In-III line.

The upper part of the casing 11, which can be supported by the stern of the hull (not shown), is provided with a plate-shaped spacer 12 therebetween.
A four-stroke two-cylinder internal combustion engine 13 is installed. The output of the internal combustion engine 13 enables the propeller to rotate via a drive shaft 14 vertically installed within the casing 11 and a forward/reverse switching mechanism (not shown).

The internal combustion engine 13 has an outer shell formed by a cylinder case 15, a crank case 16, a cylinder head 17, and a head cover 18. To cylinder case 15:
In this case, a pair of upper and lower cylinders are arranged horizontally, and a piston 19 is arranged in each cylinder.

A space defined by the cylinder case 15 and the cylinder head 1T on the upper surface side of the piston 19 is a combustion chamber 20. Further, a space defined by the cylinder case 15 and the crank case 16 on the back side of the piston 19 is defined as a crank chamber 21. A crankshaft 22 is mounted in the crank chamber 21, and the upper end of the drive shaft 14 is connected to the lower end of the crankshaft 22. The crankshaft 22 includes a crankcase 24 between webs 23 thereof.

A connecting rod 25 is connected to the crankshaft 24 at the connecting rod 25 . The small end of the connecting rod 25 is connected to the piston 19 by a piston pin 4).

A space defined by the cylinder head 1T and the cylinder cover 18 is a cam chamber 26. A cam shaft 2γ is vertically disposed in the cam chamber 26, and an intake cam 28.
An exhaust cam 29 is integrated, and a grind oil bonzo 30 is connected to its lower end. In addition, crankshaft 2
2 and a drive wheel 31 fixed to C, and 1b to the camshaft 2T.
A belt 33 is wound around the fixed driven wheel 32, and the camshaft 27 can be driven one rotation by % rotation of the crankshaft 22.

An oil pan 35 is suspended and fixed in the direction of the spacer 120F. The lubricating oil in the oil pan 35 is pumped up through a suction pipe 36 by the operation of a lubricating oil bonder 30.
Lower oil passage 3 formed in the cylinder case 15
7. The areas around the crankshaft 22 and the camshaft 27 are lubricated through oil passages such as the upper oil passage 38, and after these lubrications, the return oil passages 39 and 40 are passed through the return oil passages opened in the spacer 12. K is formed so as to return from the opening 41 into the oil pan 35.

A lower cowling 42 is fixed to the upper part of the casing 11, and an upper cowling 43 is detachably attached to the lower cowling 42. The lower cowling 42 and the lower cowling 43 are designed to prevent water droplets from entering even in bad environments such as rain and waves, and to protect the internal combustion engine 13 from fogging by rainwater, 21σ water, etc. ing.

In addition, there is a cutout at the rear of the cowling 43.
44 is fixed by 451C. cover 4
4 forms an air intake passage 46 and an air exhaust passage 47 between the upper cowling 43 and the upper cowling 43 . 11 j5, the air intake passage 46 and the exhaust passage 4γ are spaced apart from each other by +7:C.

The air intake passage 46 has one end opened outward.
, and the other end thereof is communicated with the inside of the upper cowling 43 via the air intake [148] of the upper cowling 43. That is, the air intake passage 46 is designed to be able to introduce combustion air for the internal combustion engine 13 into the lower cowling 42 and the upper cowling 43. form,
Direct intrusion of seawater spray into the upper cowling 43 can be prevented.

In addition, the -F exhaust path 4T is open to -J, -J, [1
At the same time, the other end is provided in the north cowling 43 and communicated with the IJ-exhaust port 49. In addition, the exhaust path 47 is also included.

It has a curved shape and has a one-target iJ ability to prevent seawater spray from directly entering the upper cowling 43 4).

Furthermore, in this embodiment, a lower collection cover 51 is fixed to the upper part of the internal combustion engine 13 by bolts 50 inside the lower cowling 42 and the upper cowling 43, and a lower collection cover 51 is fixed to the upper part of the internal combustion engine 13 by bolts 52 and nuts 53. A fixed upper collection cover 54 is provided. The lower collection cover 51 and the upper collection cover 54 are attached to the crankshaft 22
the top of the.

The upper part of the camshaft 21, the drive wheel 31. Driven vehicle 32. belt 3
3 and the fluffing plug 34, and can collect air around the heat dissipating parts such as the bearings of the crankshaft 22 and the camshaft 27, and the crankshaft 34. Furthermore, the collection cover 54 is formed with a discharge passage 55 that communicates with the exhaust port 49, and the collected air is passed through the discharge passage 55, the exhaust port 49. Exhaust path 47
It has the ability to flow out to the outside through. In addition, the discharge path 55
As shown in FIGS. 1 and 3, the inlet 55A of the
The fluffing plug 34 is opened at a position facing the tangential direction of the rotation of the ring gear 34A, and the collected air can be smoothly introduced by the wind flow generated by the rotation of the ring gear 34A.
I'm here. In addition, the cup/shaft 27 in the upper collection cover 54
As shown in FIG. can be smoothly moved to the inlet 55A of the discharge path 55 along the ceiling surface 54A.

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

When the internal combustion engine 13 is operating, the lubricating oil cylinder 7'30 operates to cool the area around the crankshaft 22 and the camshaft 27.
Lubricating oil at a temperature of about 00°C is circulated.

Therefore, crankcase 16. head cover 18,
The bearing portion of the crankshaft 22, the bearing portion of the camshaft 270, the crankshaft 34, etc. radiate heat based on the oil temperature (heat radiation, heat radiation based on conduction from inside the engine).

Therefore, in this embodiment, since the upper part of the crankshaft 22, the upper part of the camshaft 27, the crankshaft 34, etc. are covered by the lower collection cover 51 and the upper collection cover 54, the crankshaft 220 bearing part , heated air generated around the heat dissipating parts such as the bearing part of the camshaft 270 and the Clammag 34 is collected by the fluff 34 in the upper collection cover 54 by convection, and is collected by the air flow based on the convection and the rotation of the ring gear 34A. , to the exhaust passage 55, and the exhaust port 49. It is discharged to the outside via the exhaust passage 47. Note that during actual cruising, the air collected in the upper collection cover 54 can be more smoothly discharged to the outside under the influence of air currents and changes in air that occur around the upper cowling 43.

(7 Therefore, - according to the above embodiment, the air intake channel 46
, the temperature rise of the combustion air is prevented without mixing the combustion air introduced into the upper cowling 43 through the air intake port 48 with the heated air around the heat dissipation portion collected by the upper collection cover 54. ○h to prevent becomes one ability.

In the above embodiment, since a sealed space is formed around the heat radiation part by the single collection cover 51 and the upper collection cover 54, the heated air around the heat radiation part is completely collected and the collected air and It is possible to completely reliably prevent RU-IJ with combustion air. However, in the present invention, for example, in the above-mentioned embodiment, the F collection cover 51 is simply attached instead of the stay, and the air around the heat radiating part is collected by the L collection cover 54 supported by the stay trap. In addition, in the above embodiment, the blade collection cover 51 and the upper collection cover 54 are placed on the upper part of the crankshaft 22, on the camshaft 2.
A case has been described in which it is disposed on the upper part of 7 and around the fluffer 34. However, in the present invention, other heat dissipating parts such as the crankcase 16 and the head cover 18 are
[Therefore, it may be a cover that "collects" the air.]

Furthermore, since the above embodiment is applied to a 4-cycle internal combustion engine in which the entire engine becomes hotter than a 2-cycle internal combustion engine, it is possible to more effectively prevent increases in intake air temperature and improve output performance. . However, the present invention is also applicable to outboard motors using two-stroke internal combustion engines.

As described above, the present invention provides a collection cover in the cowling that collects air around the heat radiating part of an internal combustion engine, and directs the air collected in the collection cover to the outside through an exhaust port provided in the cowling. It was designed to be exhausted. Therefore, it is possible to suppress mixing of the heated air generated around the heat radiating portion of the internal combustion engine and the combustion air introduced into the cowling, and to prevent the temperature of the combustion air from rising. Therefore, high-density air is supplied to the internal combustion engine, making it possible to improve output performance.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an outboard motor to which an embodiment of the present invention is applied, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. FIG. 2 is a cross-sectional view along line -m. 13... Internal combustion engine, 16... Crank case, 18
・°” Head cover, 22・Back crank shaft, 21...
Camshaft, 34...Flag, 42...Lower cowling, 43゛°Upper cowling, 46''°・Air intake passage, 47
...Exhaust path, 48...Air intake port, 49...Exhaust port, 51...Lower collection cover, 54.° Upper collection cover, 55...Exhaust channel. Agent Patent Attorney Osamu Shiokawa

Claims (1)

[Claims] (1) A device for preventing a rise in the temperature inside the cowling of an outboard motor in which the internal combustion engine is housed in the cowling and the air introduced into the cowling is used as combustion air for the internal combustion engine, which captures the air around the heat radiating part of the internal combustion engine. An increase in temperature inside a cowling in an outboard motor characterized in that a collecting cover is provided inside the cowling to collect the air, and the air collected in the collecting cover is exhausted to the outside from an exhaust port provided in the cowling. Prevention device.