JP3067887B2 - Outboard engine unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine device for an outboard motor, and more particularly to an engine device for an outboard motor having a cylinder block and a cylinder head.

[0002]

2. Description of the Related Art FIG. 3 shows a state in which a general outboard motor 1 is mounted on a stern 2. In this figure, an outboard motor 1 includes an upper unit 4 equipped with an engine 3, a lower unit 6 containing a drive shaft for transmitting the output of the engine 3 to a screw 5, and an upper unit 4 and a lower unit 6. And a clamp bracket 7 for fixing the stern 2 to the stern 2.

The engine 3 has a configuration shown in FIGS. That is, a carburetor 11 is arranged on one side of a cylinder block 10 in the engine 3, and an intake pipe 14 is interposed between the carburetor 11 and an intake passage 13 formed in a cylinder head 12. The combustion gas atomized by the carburetor 11 through the pipe 14 and the intake passage 13 is turned around 180 degrees and supplied into the cylinder 15.

[0004]

However, in the conventional engine device, the connecting surfaces of the carburetor 11 and the cylinder head 12 in the intake pipe 14 are substantially 9 mm apart from each other.
Since the surface is inclined at 0 degrees, not only the number of processing jigs must be increased, but also the number of processing steps increases, which has a disadvantage of affecting the product cost.

[0005] Further, the intake pipe 14 has a shape that bends at a short distance of nearly 90 degrees due to a demand for arrangement in an extremely narrow space such as an outboard motor. This causes the loss of the intake pipe 14, and also causes difficulty in manufacturing the intake pipe 14.

Further, as is apparent from the illustrated configuration example,
Since the carburetor 11 has a cantilever structure with the intake pipe 14, there is a disadvantage that strength is disadvantageous.

[0007]

The object of the present invention is to solve the disadvantages of the prior art.
The cylinder head, especially Of the intake passage
Machining process of intake pipe connection surface and its assembly
Simplifies the process, thereby improving productivity and
To provide an outboard engine device with improved durability
And its purpose.

[0008]

According to the present invention, a crankshaft is provided.
The shaft, the piston and the direction perpendicular to the crankshaft
A cylinder block in which a piston slides in the direction
A cylinder head attached to one end of the dublock,
A spark plug attached to the cylinder head;
A carburetor that supplies the combined gas to the cylinder head,
Intake pipe connecting carburetor and intake passage
And And the intake pipe is almost straight
Formed and substantially parallel to the sliding direction of the piston
The cylinder head has a spark plug on one side.
The intake and exhaust passages are integrally curved on the other side
And each opening of the intake passage and the exhaust passage.
Face against the cylinder block of the cylinder head
Are set on the same surface as the mating surface. In addition,
Cylinder block to the cylinder head side exhaust passage.
Exhaust passage on the cylinder block side
Arrange the exhaust passage by sliding the intake pipe and piston.
It is configured to be set between the center axis . This aims to achieve the above-mentioned object.

[0009]

The opening surfaces of the intake passage and the exhaust passage are connected to the cylinder.
On the same plane as the mating surface of the cylinder with the cylinder block
Setting, the opening surface and the mating surface are the same.
At the same time, the connection surface can be processed using a single jig, and the passage in the pipe can be formed in a straight line, so that the intake resistance can be suppressed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In the description of this embodiment, the same reference numerals are used for the same structures as those in the conventional example, and the description will be omitted or simplified.

FIG. 1 shows the overall structure of an intake device 18 in a two-cylinder engine 3. FIG. 2 shows a view as seen from the direction of arrows AA in FIG. FIG. 1 is a cross-sectional view at the position of the exhaust valve 20, and a part of an intake passage 13 formed in the cylinder head 12 is indicated by a dotted line.

As shown in FIG . 1 or FIG.
3 is the crankshaft, piston and crankshaft
Cylinder block with piston sliding in the direction perpendicular to the shaft
And attached to one end of the cylinder block 10
Cylinder head 12 and the cylinder head 12
Install the spark plug and premix gas to the cylinder.
And a carburetor 11 for supplying the carburetor 11
Pipe 1 that connects cylinder head 12 to cylinder
4 is provided. The cylinder head 12 is located on one side.
A spark plug is attached to the
The air passages are formed integrally curved, and
Each opening surface of the passage 13 and the exhaust passage is
On the same surface as the mating surface for cylinder block 10
You have set. Further, in FIGS. 1 and 2, the cylinder head 12 is partially be the projecting portion 12A which is formed to protrude carburetor 11 side, the intake passage 13 is formed in the projecting portion 12A. This intake passage 13
Indicates that the premixed gas supplied from the carburetor 11 is approximately 18
It is formed so as to form a gentle curve as a whole so that it can be supplied in the direction of turning by 0 degrees, so that the suction resistance can be suppressed small.

A connecting surface 21 between the projection 12A, which is the suction side end of the intake passage 13, and the intake pipe 14 extends in a direction parallel to a connecting surface 22 between the intake pipe 14 and the carburetor 11. The connection between the intake pipe 14 and the connection surface 12B can be made via an appropriate fixing means such as a bolt. The connection between the intake pipe 14 and the carburetor 11 is performed by connecting a flange 24 formed on the intake pipe 14 to the carburetor 11.
Is carried out by bolts or the like (not shown) in a state where the flange 25 provided on the butt is abutted.

[0014] The intake pipe 14 is
Due to the presence of the intake passage 13 formed in A, the intake passage 13 can be formed by a relatively short member, and the internal passage 14A also extends linearly. Also, as shown in the figure,
The intake pipe 14 is almost parallel to the sliding direction of the piston.
Connected to the opening surface of the intake passage 13 of the cylinder head 12
ing. Further, as shown, the cylinder blow
Communicates with the exhaust passage on the cylinder head 12 side.
An exhaust passage on the cylinder block side is formed. this
The layout of the exhaust passage on the cylinder block side is
Between the piston 14 and the center axis of the piston.
You.

When assembling the apparatus of this embodiment, the protrusion 12A of the cylinder head 12 and the intake pipe 14
Are connected by bolts or the like.

Next, the flange 24 of the intake pipe 14 and the flange 25 of the carburetor 11 are butted,
The two are connected in the same manner as described above, whereby the assembly of the intake device 20 is completed.

At the time of intake at the start of the engine 3, the intake air is sucked from below in the state of FIG. 1 and the intake air is premixed with fuel by the carburetor 11. Carburetor 1
The premixed gas in 1 is rotated through substantially 180 degrees through the intake pipe 14 and the inside of the intake passage 13 and supplied to the cylinder 15.

Therefore, according to the above configuration of the present invention, the intake passage in the protruding portion 12A formed in the cylinder head 12 is formed relatively gently, so that the intake resistance in this region is favorably reduced. There is an effect that can be.

Also, each opening surface of the intake passage and the exhaust passage is
The mating surface of the cylinder head against the cylinder block
Since they are set on the same plane,
It is only necessary to employ a single processing jig for the end face of the intake pipe 14 as well as to reduce the number of manufacturing steps as compared with the conventional one which is inclined at approximately 90 degrees. Can be realized, and it is expected that the manufacturing cost is reduced.

Further, since the length of the intake pipe 14 can be set shorter than that of the conventional example, the strength is excellent, and even if the carburetor 11 has a cantilever structure, a decrease in strength due to vibration or the like can be suppressed as much as possible. This has the effect.

The cylinder head 12 can be integrally formed by die casting or the like, and the protrusion 12A can be formed without difficulty. It is technically difficult to form the intake passage 13 in the protrusion 12A. Since it is considered to be small, there is no inconvenience that causes an increase in manufacturing cost.

Although the above-described embodiment has been illustrated and described as a two-cylinder engine, the present invention is not limited to this and can be applied to a single-cylinder engine or an engine having three or more cylinders.

Further, the type of the engine is not particularly limited.
Various types of engines such as HC and DOHC can be exemplified.

[0024]

The present invention is constructed and operated as described above. According to this, the connecting surface of the intake pipe can be processed by a single processing jig or the like, and the number of manufacturing steps can be reduced. There is an effect that it is possible to provide an engine device for an outboard motor capable of reducing the intake resistance as much as possible, reducing the cause of the output loss, and improving the strength.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an engine device according to the present invention in a partially sectional view.

FIG. 2 is a view as seen from line AA in FIG. 1;

FIG. 3 is an external view for explaining a general configuration of the outboard motor.

FIG. 4 is an explanatory view partially sectioned along the direction of arrows BB in FIG. 3;

5 is an enlarged view similar to FIG. 1 but showing the engine and the intake device in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Carburetor 12 Cylinder head 13 Intake passage 14 Intake pipe 18 Intake device 21 Connection surface 22 Connection surface

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02M 35/10 101 B63H 20/00 F02F 1/42 F02M 17/34

Claims (1)

(57) [Claims] 1. A crankshaft, a piston, and
The piston slides in the direction perpendicular to the crankshaft
Cylinder block and one end of the cylinder block
With the attached cylinder head and the cylinder head
The spark plug to be attached and the premix gas to the cylinder
And a carburetor to be supplied to the
An intake pipe for connecting to the Linda head.
The cylinder head has a spark plug attached to one side.
The intake and exhaust passages are integrally curved on the other side.
And the opening surfaces of these intake passages and exhaust passages
Of the cylinder head to the cylinder block
The intake pipe is set on the same surface as the contact surface, and the intake pipe is formed in a substantially linear shape.
Of the cylinder head substantially parallel to the sliding direction of the piston.
The cylinder block is connected to the opening surface of the intake passage,
Form an exhaust passage on the cylinder block side that communicates with the passage
And the arrangement of the exhaust passage is changed to the intake pipe.
And the piston slide center axis.
Outboard engine equipment.