JPH06104475B2 - Outboard motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention mounts an engine on an upper part of an extension case in which a drive shaft for driving a propeller is vertically installed. The present invention relates to improvement of an outboard motor in which a crankshaft of this engine is connected to the drive shaft.

(2) Conventional Technology In the conventional outboard motor, the crankshaft and the drive shaft are directly connected to each other,
The reduction ratio between the crankshaft and the propeller is set constant by a transmission device that connects the drive shaft and the propeller (see, for example, Japanese Utility Model Laid-Open No. 53-154592).

(3) Problems to be Solved by the Invention In a conventional outboard motor, if the reduction ratio is set small in order to make the outboard motor a high speed type, it becomes difficult to perform extremely low speed navigation of the hull, and the outboard motor is a low speed type Therefore, if the reduction ratio is set to a large value, the efficiency of the hull at high speed is reduced. Therefore, it is difficult to control the navigation speed with a single outboard motor over a wide speed range from extremely low speed to high speed.

Therefore, it has already been proposed to provide a transmission between the crankshaft and the drive shaft so that the transmission is housed in an oil pan connected to the lower surface of the engine (for example, JP-A-60-
However, since the transmission directly supports the oil pan, the load on the oil pan is large and it is difficult to reduce the thickness and weight of the oil pan. There is also a problem that the molding is not easy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an outboard motor that can solve all the problems of the conventional ones.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention arranges a crankshaft and a drive shaft vertically with a space between them, A transmission that can switch the gear ratio between at least two stages, high and low, is installed between the shafts, and the transmission is housed in an oil pan that is attached to the lower surface of the engine and stores lubricating oil for the engine. The bracket is attached to the lower surface of the engine in the oil pan to support the transmission,
An oil pump, which is driven by the transmission and supplies lubricating oil in an oil pan to the engine, is attached to the bracket, and a discharge port of the oil pump is formed in the bracket.

(2) Action When the transmission is set to the high speed side, the propeller can be driven at a relatively high speed, enabling high-speed navigation of the hull, and when the transmission is set to the low speed side, the propeller can move at a relatively low speed. It can be driven by and enables extremely low speed navigation of the hull. Since such a transmission is housed in the oil pan of the engine, the transmission can be effectively lubricated by the splash of lubricating oil generated by the operation of the transmission, and the oil pan also serves as the mission case. Therefore, simplification of the structure is brought about.

Also, since the bracket that is independent of the oil pan supports the transmission, the load on the oil pan is reduced,
Also, because the oil pump is attached to the bracket, the installation space for the oil pump is eliminated from the engine, and the engine can be made smaller, and the bracket also serves as a conduit for supplying the oil discharged from the oil pump to the engine. , The piping structure is simplified.

(3) Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings. First, in FIG. 1, an outboard motor 1 is a stern plate of a hull S.
An extension case 3 equipped with a stern bracket 2 clamped to Sa in the front part, an engine 4 mounted on the upper part of the extension case 3, and a propeller 5 attached to the lower part of the extension case 3 by a rear wall. An engine cover 7 having a supporting gear case 6 and covering the engine 4 is attached to the extension case 3.

The engine 4 is arranged with the crankshaft 8 oriented vertically, and a drive shaft 9 driven from the crankshaft 8 is arranged in the extension case 3 so as to run longitudinally. Before the propeller 5 can be driven from the drive shaft 9 and its rotation direction can be switched between forward and reverse, a reverse drive transmission 10 is housed in the gear case 6.

In FIG. 2, the engine body 11 of the engine 4 is
Cylinder block 1 with a pair of upper and lower cylinders 12, 12
3, a crankcase 14 attached to one end surface of the cylinder block 13, and a cylinder head 15 attached to the other end surface of the cylinder block 13, and the cylinder head 15 is directed rearward of the hull S. Are arranged.

The crankshaft 8 includes three plain bearings 1 arranged at equal intervals between the cylinder block 13 and the crankcase 14.
The connecting rod is connected to the pistons 17 and 17 that are rotatably sandwiched via 6, 16 and 16 and that slide into the cylinders 12 and 12, respectively.
Connected via 18, 18.

The cylinder head 15 supports a cam shaft 19 for opening and closing intake and exhaust valves (not shown) of the cylinders 12, 12.

An oil pan 20 is bonded to the lower surfaces of the cylinder block 13 and the crankcase 14, and a predetermined amount of lubricating oil L for the engine 4 is stored in the oil pan 20. This oil pan
In FIG. 20, the crankshaft 8 and the drive shaft 9 are coaxially arranged with a space above and below and are connected to each other via a transmission 21, and a part of the transmission 21 is immersed in the lubricating oil L. To be done.

The transmission 21 includes a main shaft 23 driven by the reduction gear train 22 on the crankshaft 8, a sub-shaft 24 arranged in parallel with the main shaft 23, and a high-speed gear train 25 provided over both shafts 23, 24. And a low speed gear train 26 and a dog clutch 27 slidably fitted to the main shaft 23 so as to be able to selectively connect either one of the two gear trains 25 and 26 to the main shaft 23. 23,2
4 is arranged vertically like the crankshaft 8. Spindle 2
The upper end of 3 is rotatably supported by the cylinder block 13 via a ball bearing 28, and the upper end of the auxiliary shaft 24 is rotatably supported by the crankshaft 8 via a plain bearing 29. Further, the lower ends of the main shaft 23 and the sub shaft 24 are connected to the lower surfaces of the cylinder block 13 and the crankcase 14 in the oil pan 20 by L.
The bracket 30 of the mold is rotatably supported by bearings 31 and 32, and the upper end of the drive shaft 9 is splined to the lower end of the counter shaft 24.

An oil pump 33 is provided on the bracket 30 below the main shaft 23, and the pump shaft 34 is connected to the main shaft 23 by a joint pin 35.

The suction port 36 and the discharge port 37 of the oil pump 33 are formed in the bracket 30 together with the pump housing 38 that houses the oil pump 33. Intake port 36 has an oil pan
A suction pipe 40 connected to an oil filter 39 immersed in the lubricating oil L in 20 is connected, and a first oil passage 41 formed in the side wall of the cylinder block 13 is connected to the discharge port 37, the cylinder block 13 and the cylinder head. The second oil passage 42 formed on the lower wall of 15 is connected.

The first oil passage 41 has three oil supply holes 43, 43, 43 branched therefrom.
Through the three said plain bearings 16,16, for the crankshaft 8
16 plain bearings on both the top and bottom
The inner peripheral surface of is connected to the inner peripheral surfaces of the large ends of the connecting rods 18, 18 through oiling holes 44, 44 formed in the crankshaft 8. Further, the lower oil supply hole 44 communicates with the inner peripheral surface of the plain bearing 29 for the auxiliary shaft 24 via an oil supply hole 45 branched from the lower oil supply hole 44.

On the other hand, the second oil passage 42 communicates with an oil supply hole 46 formed in the center of the cam shaft 19, and the oil supply hole 46 communicates with a lubricating portion around the cam shaft 19.

At the center of the main shaft 23, there is an oil supply hole 47 having an open upper end.
The oil supply hole 47 is bored over substantially the entire length of 23 and has a plurality of lateral holes.
It communicates with the lubrication section of the high and low speed gear trains 25 and 26 via 48 and 48.

A funnel-shaped oil collector 49 is provided above the ball bearing 28 that supports the upper end of the main shaft 23, and the center cylinder 49a is projected into the oil supply hole 47. A through hole 50 communicating with the inside is formed in the bottom wall of the engine body 11.

The lower surface of the cylinder head 15 and the outer rear surface of the extension case 3 are connected by a main exhaust pipe 51 connected to a waste port 53 in the cylinder head 15, and communicated with the lower end of the main exhaust pipe 51 with the open end facing downward. The auxiliary exhaust pipe 52 is attached to the inner rear surface of the extension case 3 with the oil pan 20 below. By doing so, the oil pan 20 can be formed in a large capacity while avoiding the enlargement of the extension case 3 by the main exhaust pipe 51, and the extension case 3 can be prevented from being heated by the exhaust gas. Allows underwater exhaust through.

Next, the operation of this embodiment will be described.

While the engine 4 is operating, the dog clutch 27 is operated upward by operating a gear shift lever (not shown), and the high speed gear train 25
, The reduction gear train 22 from the crankshaft 8
The rotational torque transmitted to the main shaft 23 via the
It is transmitted to the auxiliary shaft 24 and the drive shaft 9 via 25, and further transmitted to the propeller 5 via the forward / reverse switching transmission 10, which can be driven at a relatively high speed.
Is operated downward to connect the low speed gear train 26 to the main shaft 23,
Since the rotational torque of the main shaft 23 is transmitted to the sub shaft 24 side via the low speed gear train 26, the propeller 5 can be driven at a relatively low speed.

Thus, in the operating state of the high speed gear train 25, the maximum speed of the propeller 5 can be obtained at the maximum output of the engine 4 to allow the hull S to travel at the maximum speed. However, in this case, even if the output of the engine 4 is sufficiently reduced, there is a limit to lowering the navigation speed, and it is difficult to perform extremely low speed navigation. Therefore, this time, by operating the low speed gear train 26 and controlling the output of the engine 4, the low speed rotation of the propeller 5 can be freely adjusted, so that the extremely low speed navigation of the hull S can be easily performed. .

Further, if the transmission 21 is switched as described above in accordance with the load fluctuation of the hull S, that is, the increase or decrease of the number of passengers or luggage, the propeller speed according to the load of the hull S does not change the pitch of the propeller 5. Therefore, the output of the engine 4 can be effectively exerted and the hull S can be efficiently navigated.

By the way, the transmission 21 is housed in an oil pan 20 bound to the lower surface of the engine body 11 and partly immersed in the lubricating oil L. Each part of the transmission 21 can be effectively lubricated by the scattered oil method.

Further, the lubricating oil L in the oil pan 20 is sucked into the oil pump 33 driven by the main shaft 23 through the oil filter 39, and is then discharged to the discharge port 37, so that the first and second oil passages are formed.
It is pumped to 41 and 42. The oil in the first oil passage 41 is supplied to the oil supply holes 43,
Plain bearings 16,16,16 supporting the crankshaft 8 through 43,43
Connected to the connecting rod 18,1 through the oiling holes 4,44.
It is fed into the large end of 8 and into a plain bearing 29 that supports the countershaft 24 and lubricates them.

The oil in the second oil passage 42 is sent to the lubrication portion around the cam shaft 19 through the oil supply hole 46.

The oil thus lubricated flows down to the bottom of the crankcase 14 and moves to the oil collector 49 through the through hole 50, where it is collected and supplied to the oil supply hole 47 in the main shaft 23.
It flows out from the lateral holes 48, 48 and lubricates the lubrication part around the main shaft 23,
Then, the oil is returned to the oil pan 20. Therefore, the transmission 21 is effectively lubricated by the oil after lubricating the engine 4.

C. Effects of the Invention As described above, according to the present invention, since the high speed machines capable of switching the gear ratio between the crankshaft and the drive shaft to at least two stages, high and low, are connected to each other, the transmission is It is possible to freely set one of the outboard motors to a high speed type or a low speed type by switching, and it becomes easy to control the navigation speed and the range of use can be expanded. Moreover, since the transmission is bound to the lower surface of the engine and housed in the oil pan,
Not only can lubrication of the transmission be performed easily and reliably with the lubricating oil of the engine, but the oil pan also serves as the mission case, and the structure can be simplified.

In addition, since the above-mentioned transmission is supported by a bracket that is supported on the bottom surface of the engine and is independent of the oil pan, it is possible to avoid applying the load of the transmission to the oil pan and reduce the load on the oil pan. Therefore, it is possible to reduce the thickness and weight of the oil pan and to easily form the oil pan. Moreover, since the oil pump is attached to the bracket and the discharge port of the pump is formed in the bracket, not only can the installation space for the oil pump be eliminated from the engine, but the engine can be downsized, and the bracket Also, the oil pump can be used also as a discharge oil supply pipeline from the oil pump to the engine, which can contribute to simplification of the piping structure.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a side view of an outboard motor, and FIG. 2 is a vertical cross-sectional side view of an engine portion of the outboard motor. L: Lubricating oil 1 ... Outboard motor, 3 ... Extension case, 4 ...
Engine, 5 ... propeller, 6 ... gear case, 8 ...
Crankshaft, 9 ... Drive shaft, 11 ... Engine body, 20 ...
… Oil pan, 21 …… Transmission, 23 …… Main shaft, 24 …… Sub shaft, 25 …… High speed gear train, 26 …… Low speed gear train, 27 …… Dog clutch, 30 …… Bracket, 33 …… Oil pump , 37
…… Discharge port, 49 …… Oil collector

Claims (2)

[Claims] 1. An engine (4) is mounted on top of an extension case (3) having a drive shaft (9) for driving a propeller (5) longitudinally arranged therein. Vertically extending crankshaft (8)
In the outboard motor in which the crankshaft (8) and the drive shaft (9) are connected to the drive shaft (9), the crankshaft (8) and the drive shaft (9) are vertically spaced apart from each other, and the crankshaft (8) and the drive shaft (9) are arranged.
A transmission (21) capable of switching the gear ratio between at least two stages, high and low, is interposed between the transmission (21) and the lower surface of the engine (4) for connecting the transmission (21) to the engine (4). The transmission (21) is supported by a bracket (30) that is housed in an oil pan (20) that stores lubricating oil and that is attached to the lower surface of the engine (4) within the oil pan (20). An oil pump (33), which is driven by a transmission (21) and supplies the lubricating oil in the oil pan (20) to the engine (4), is attached to the bracket (30), and a discharge port of the oil pump (33). An outboard motor having the bracket (30) formed on the bracket (30). 2. An outboard motor according to claim 1, wherein an oil collector (49) for collecting lubricating oil that has finished lubricating the engine (4) is provided above the transmission (21).
An outboard motor characterized in that the outlet of the oil collector (49) is communicated with the lubricating portion of the transmission (21).