JPS639087B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water cooling system for an engine in an outboard motor.

Generally, outboard motors use water-cooled engines, which draw in water from outside the machine through a suction port formed in a lower casing that is immersed below the water surface outside the machine, and pump it into the waterway around the engine using a cooling water pump. ing. Incidentally, even if such cooling water is seawater or fresh water, it may contain mud or sand, and therefore mud and sand may be sent into the waterway surrounding the engine along with the water. However,
In the middle of the waterway, there is a room with an expanded passage area.
In other words, when an expansion chamber is formed, a portion where cooling water accumulates, that is, stagnation occurs.
When the cooling water mixed with mud and sand is flushed, the mud and sand accumulates in the stagnant portion, resulting in clogging of the water channel.

The present invention was developed based on the above circumstances, and is an outboard vessel that eliminates stagnation by introducing a pilot water flow that disturbs the main flow of cooling water into the expansion chamber, prevents the accumulation of mud and sand, and eliminates clogging of waterways. The aim is to provide a water cooling system for engines in aircraft.

An embodiment of the present invention will be described below based on the drawings.

In the figure, 1 is an engine cowling, 2 is an upper casing, and 3 is a lower casing. A water-cooled V-type 4-cylinder two-stroke engine 4 is housed within the engine cowling 1. This engine 4
A drive shaft 6 is connected to the crankshaft 5 of the
The drive shaft 6 penetrates through the upper casing 2 and the lower casing 3 to rotationally drive the propeller 7. A cooling water pump 8 is installed in the lower part of the upper casing 2, and the pump 8 is rotated by a drive shaft 6. A suction port 9 for taking in cooling water such as seawater is formed on the side surface of the lower casing 3, and this suction port 9 is communicated with the pump 8. A delivery pipe 10 is connected to the discharge port of the pump 8, and this pipe 10 is connected to a water jacket of the engine 4.

The engine 4 has a horizontal V-shape as shown in FIG. 2, and two cylinders are disposed at the top and bottom on each side of the V-shape. In FIG. 2, 11 indicates an intake silencer, and 12 indicates a multiple carburetor. The engine 4 has four cylinders integrally forming a cylinder block 15, and two cylinder heads 16a and 16b are attached to the cylinder block 15 corresponding to the left and right sides. Each of the single cylinder heads 16a, 16b covers two cylinders along the upper and lower sides. And each cylinder head 16a, 16b
Cylinder head covers 17a and 17b are attached to the cylinder head covers 17a and 17b.

The cooling water discharged from the cooling water pump 8 is sent through the delivery pipe 10 to a water jacket 18 formed inside the cylinder block 15, as shown in FIG. 3, to cool the cylinder block 15. do. Note that this water jacket 18 surrounds each cylinder and an exhaust passage (not shown).

The cooling water that has passed through the water jacket 18 of the cylinder block 15 is branched and directed to each cylinder head 16a, 16b. Each cylinder head 16a, 16b has a cylinder head cover 17
Seal 1 of packing material etc. between a and 17b.
A water passage 20 is formed in the cylinder heads 16a, 16b separated by the sealing material 19. The water channel 20 communicates with a water channel 21 formed in the cylinder head covers 17a, 17b at one end of the cylinder heads 16a, 16b. Heat-responsive valves 22a, 22b and pressure control valves 23a, 23b are provided at locations where the water channels 20 and 21 communicate with each other. Therefore, based on these valves 22a, 22b and 23a, 23b, waterway 20 is an inflow waterway, and waterway 21 is an outlet waterway. After the discharge waterway 21 flows out of the cylinder head covers 17a and 17b, it enters the cylinder block 15 again, passes through the upper casing 2 shown in FIG.
The water is removed from the drain hole 24 of the drain hole 24.
Note that 25 in FIG. 3 indicates a spark plug.

One of the pressure control valves 23a, 23b is constructed as shown in FIGS. 4 to 6. That is, 26 is an inflow chamber connected to the inflow channel 20, and the passage area of the inflow chamber 26 is larger than that of the outlet 20a of the inflow channel 20, thereby forming an expansion chamber of the present invention. A valve hole 2 is provided in the cylinder head cover 17a facing the inflow chamber 26.
7 and 28 are open. One valve hole 27
The heat-responsive valve 22a described above is attached to the valve 22a, and although it is not shown in detail, when the temperature of the cooling water reaches a predetermined value or higher, the valve hole 27 is opened and the cooling water in the inlet chamber 26 is directed to the direction indicated by the broken line. As shown in , it is designed to flow toward an outflow chamber 29 . The outflow chamber 29 is constructed by attaching a valve cover 30 to the cylinder head cover 17a.

A pressure control valve 23a is attached to the other valve hole 28. A valve seat 31 made of rubber or the like is fitted onto the inner peripheral surface of the valve hole 28, and a valve body 33 is removably seated on the upper surface of this valve seat 31, that is, the surface facing the outflow chamber 32. . The valve body 33 has a disk shape, and is provided with guide portions 34 and 35 formed of, for example, cross-shaped ribs on its upper and lower sides. The lower guide portion 34 enters into the valve seat valve 31 so as to be freely retractable. Further, the upper guide portion 35 serves as a locking portion for a coil spring 36, and locks the lower end of the coil spring 36 which is bridged between the valve cover 30 and the valve body 33. Therefore, when the water pressure in the inflow chamber 26 rises and overcomes the pressing force of the coil spring 36, the valve body 33 is pushed and the valve hole 2
It is designed to open 8. Note that the pressure control valve 23
The outflow chamber 32 of a and the outflow chamber 29 of the thermally responsive valve 22a communicate with each other via a communication hole 37, and these outflow chambers 29, 32 communicate with the outflow waterway 21.

By the way, the inflow chamber 26 has introduction holes 40 and 4 at a position different from the outlet 20a of the inflow waterway 20.
0 is established. These introduction holes 40, 40 are
As shown in FIG. 6, it communicates with the inflow waterway 20. Therefore, the outlet 20a of the inflow waterway 20
Assuming that the direction of water flowing into the inflow chamber 26 from the main flow A is indicated by the thick arrow, the introduction hole 40,
The pilot water flow flowing into the inflow chamber 26 from 40 flows in a direction different from the main flow A as shown by a thin arrow B.

The operation of the embodiment configured as described above will be explained.

During operation of the engine 4, water from outside the machine is sucked up by the cooling water pump 8, passes through the cylinder block 15, branches into each cylinder head 16a, 16b, and enters the inlet chamber via the inlet water channel 20, 20, respectively. It flows into 26,26.

The thermally responsive valves 22a and 22b open the valve hole 27 when the temperature of the cooling water reaches a certain value or higher, so the valve hole 27 opens when the engine temperature has not yet risen, such as immediately after starting the engine. is closed, thereby stopping the flow of cooling water.
This promotes a rise in engine temperature.

When the temperature of the cooling water reaches a certain value or more, the thermally responsive valves 22a and 22b are operated to open the valve holes 27 and 27, so that the cooling water in the inflow chambers 26 and 26 flows toward the outflow chamber 29. That is, water flows from the inflow channel 20 toward the outflow channel 21 and is then drained from the drain hole 24.

When the engine 4 is operating at high speed or accelerating, the rotational speed of the cooling water pump 8 is also increased, so the flow rate of cooling water increases and the water pressure increases. This water pressure causes pressure control valves 23a and 23b to
The valve bodies 33, 33 are pushed open against the coil springs 36, 36, respectively, thereby opening the valve holes 28, 28, and cooling water flows from the inflow chamber 26 to the discharge chamber 32.

By the way, since the inflow chamber 26 is formed to have a large capacity, the outflow port 20a of the inflow channel 20
The main stream A flowing from the main stream A tends to stay in the inflow chamber 26 and cause stagnation. However, since the pilot water flow B is introduced into the inflow chamber 26 through the introduction holes 40, 40, the pilot water flow B collides with the main flow A, thereby generating a turbulent flow within the inflow chamber 26. This turbulent flow also disturbs the muddy sand mixed in the cooling water, so that the muddy sand does not accumulate at the bottom of the inflow chamber 26, and the muddy sand that had accumulated at the bottom also rides the turbulent flow and flows into the valve hole 26. be excluded from

As a result, the cooling water channel is not clogged with mud and sand, and the flow of cooling water is maintained smoothly.

Although the inflow chambers of the thermally responsive valve and the pressure control valve have been described in the above embodiments, the present invention is not limited to the above inflow chambers, and may be applied to cooling water channels having an expansion chamber with an enlarged passage area. It is possible to implement it if

As detailed above, in the present invention, an introduction hole for guiding cooling water in a direction different from the main flow is formed in an expansion chamber that causes stagnation in the main flow of cooling water due to an increase in the passage area. The pilot water flow led from the introduction hole disturbs the main flow,
Since stagnation is thus prevented, muddy sand that is about to stay and accumulate in the expansion chamber or muddy sand that has already accumulated can be agitated and discharged together with the main stream. This prevents clogging of the waterway and ensures smooth flow.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side view of the outboard motor, FIG. 2 is a top view of the engine, FIG. 3 is a schematic system diagram showing the cooling system, and FIG. 4 is a schematic diagram showing the cooling system. In Figure 3 - Sectional view along the line, Figures 5 and 6
The figures are cross-sectional views taken along lines VV and - in FIG. 4, respectively. 4...Engine, 8...Cooling water pump, 9...
Suction port, 20... Inflow waterway, 21... Outflow waterway,
26...Inflow chamber (expansion chamber), 27, 28...Valve hole,
22a, 22b...thermally responsive valve, 23a, 23b...
...Pressure control valve, 40...Introduction hole.

Claims (1)

[Claims] 1 An outboard engine in which cooling water is introduced from a suction port opened below the water surface outside the engine by a cooling water pump, and this cooling water is allowed to flow around the engine to cool the engine. An expansion chamber with an expanded passage area is formed in the middle of the water channel, and an introduction hole is formed in the expansion chamber to guide the cooling water in a direction different from the main flow of the cooling water, and the cooling water is guided from the introduction hole. 1. A water cooling device for an engine in an outboard motor, characterized in that the main flow is disturbed by a pilot water flow.