Fuel supply apparatus of outboard motor

BACKGROUND OF THE INVENTION

The present invention relates to a fuel supply apparatus of an outboard motor having an improved arrangement or structure.

In recent years, a four-stroke-cycle engine has been mainly utilized. Like the two-stroke-cycle engine, the four-stroke-cycle engine is mounted uprightly to the outboard motor in a state mounted to a hull, for example, in which a crankshaft is disposed so as to extend perpendicularly in an engine crankcase.

An intake manifold extending from a cylinder head on the rear side of the engine is curved and connected to a cylinder block or a fuel supply apparatus disposed on the side of the crankcase. An air-fuel supply means such as carburetors as many, in number, as cylinders or an air amount-adjusting device (throttle body) is continuously formed with the fuel supply apparatus by a connecting member, and an intake (inlet) noise silencer is connected to the front portion of the fuel supply apparatus.

An engine starting operation assisting device for easily starting the engine operation and a speed reduction control device for preventing an engine stall resulted from a rapid throttle closing operation are disposed in association with the fuel supply apparatus of the outboard motor.

In the known art, such engine starting operation assisting device and the speed reduction control device are disposed to the cylinder head of the engine independent from the air-fuel supply means. For this reason, it is necessary to carry out a setting operation such as linkage adjustment in an assembling line after the assembling of the air-fuel supply means, the starting operation assisting device and the speed reduction control device.

However, in such engine assembling line, the setting adjustment working is troublesome and inconvenient for the entire assembling working, which results in adverse affection on the outboard motor manufacturing process, as well as adverse affection on uniform or constant engine performance after the assembling of the engine. Moreover, it is necessary to again perform the setting adjustment working at the time of re-assembling of the engine after the once disassembling of the air-fuel supply means, thus being troublesome and not convenient for the engine performance and maintenance.

SUMMARY OF THE INVENTION

The present invention was conceived to solve or substantially eliminate defects or drawbacks encountered in the prior art mentioned above, and a primary object of the present invention is to provide a fuel supply apparatus of an outboard motor in which the outboard motor can be easily manufactured by enabling various setting workings before the assembling of the fuel supply apparatus with the engine to thereby easily manufacture the outboard motor with uniform engine operation performance having no defect due to the setting working.

Another object of the present invention is to provide a fuel supply apparatus of an outboard motor capable of making the fuel supply apparatus into a small assembly, which is easily detachable to an engine of the outboard motor for easy transportation, packaging and maintenance.

These and other objects can be achieved according to the present invention by providing a fuel supply apparatus of an outboard motor provided with an engine having a crankcase in which a crankshaft is perpendicularly arranged in a state that the outboard motor is mounted to a hull, the fuel supply apparatus comprising:

an interlocking mount member to be mounted to the engine;

a plurality of air-fuel mixture supply means mounted to the interlocking mount member;

an intake noise silencer mounted to the air-fuel supply means;

a starting operation assisting device for assisting smooth starting of an engine operation; and

a speed reduction control device for preventing an engine stall from causing,

the starting operation assisting device and the speed reduction control device being mounted to said interlocking mount member.

In a preferred embodiment, the intake noise silencer is mounted detachably to the air-fuel mixture supply means after the air-fuel supply means is mounted to the engine. The intake noise silencer is mounted to the air-fuel supply means through intake pipes.

Further, the air-fuel supply means are preferably a plurality of carburetors.

According to the structures or characters of the present invention mentioned above, the air-fuel mixture supply means, the engine starting operation assisting device and the speed reduction control device are assembled together as one unit with the interlocking mount member. Therefore, the setting adjustment between these members can be performed before the assembling with the engine, thus workability for the manufacturing of the outboard motor can be improved. Moreover, the engine performance influenced by the setting working of the fuel supply apparatus can be uniformly achieved. Furthermore, even if the fuel supply apparatus is detached from the engine, the relative positional relationship of the starting operation assisting device and the speed reduction control device with respect to the air-fuel supply means is not changed, so that the adjustment working can be eliminated which was required every assembling time in the prior art, so that the workability can be improved and the re-adjusting working can be eliminated, thus remarkably improving the engine performance and maintenance working.

Still furthermore, according to the further feature of the present invention, since the intake noise silencer can be mounted to the air-fuel mixture supply means such as carburetor after being assembled to the engine body, and accordingly, it is not necessary for the intake noise silencer to be initially mounted to the air-fuel mixture supply means, and hence, the fuel supply apparatus, as a whole structure, can be handled as small one unit, being convenient for transportation, storage, packaging workings.

The nature and further characteristic features of the present invention will be made more clear from the following descriptions made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1

is a right side view of a portion of an outboard motor near an engine thereof to which the present invention is applicable;

FIG. 2

is a plan view of the outboard motor shown from a direction of an arrow II in

FIG. 1

;

FIG. 3

is a right side view of a fuel supply device of the outboard motor of

FIG. 1

;

FIG. 4

is a left side view of the fuel supply device of the outboard motor representing one embodiment of the present invention;

FIG. 5

is a plan view of the fuel supply device; and

FIG. 6

is a view shown from a direction of an arrow VI in FIG.

4

.

DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will be described hereunder with reference to the accompanying drawings.

With reference to

FIG. 1

, an outboard motor

1

has a forward portion (right side portion as viewed) which is mounted to a hull, for example, and has a rearward portion (left side portion as viewed).

With reference to

FIGS. 1 and 2

, an engine

2

is mounted to the outboard motor

1

at an upper portion thereof in a state of the outboard motor

1

mounted to a hull, for example. The engine

2

is, for example, an in-line three-cylinder four-stroke-cycle engine, and the engine

2

is disposed above an engine holder

4

having substantially flat-plate like structure, in which a crankshaft

3

(which is shown only with its central axis in

FIG. 1

for showing the position thereof) is perpendicularly arranged.

An oil pan

5

is fixedly mounted to a lower portion of the engine holder

4

, and a drive shaft housing and a gear housing, which are not shown, are disposed below the oil pan

5

. A screw propeller is also provided for the gear housing.

In the engine

2

, there are disposed, from the front side (right side as viewed in FIG.

1

), a crankcase

7

, a cylinder block

8

, a cylinder head

9

and a head cover

10

. The entire structure of the engine

2

, the engine holder

4

and the oil pan

5

are covered by an engine cover

11

formed of synthetic resin material for waterproofing. The engine cover

11

comprises upper and lower half cover sections with a sealing member portion

12

being a boundary therebetween, and engine maintenance or inspection is performed by removing the upper half cover section.

A fuel supply apparatus

15

together with a fuel pump

14

is disposed, for example, on a right side of the cylinder block

8

of the engine

2

, and an exhaust device

16

, an ignition device

17

, an electrical equipment box

18

and the like are disposed on a left side of the cylinder block

8

. Furthermore, a generator (dynamo)

19

(

FIG. 2

) and a re-coil starter

20

(

FIG. 1

) are disposed to an upper portion of the engine

2

, and a starter motor

21

is also disposed to a front portion of the engine

2

.

An intake manifold

23

, which is formed with thee input pipes, disposed so as to extend from the right side surface portion of the cylinder head

9

, and these input pipes are curved forward by about 90° and connected to a substantially flat plate-like connection flange

24

. The input pipes of the intake manifold

23

and the connection flange

24

are integrally formed together with the cylinder head

9

.

With reference to

FIGS. 3

to

5

, in the fuel supply apparatus

15

, three carburetors

25

a,

25

b

and

25

c

are vertically continuously mounted to a substantially flat plate-like mounting member

26

as an interlocking mount member, and an intake (inlet) noise silencer

28

is connected to front portions of the carburetors

25

a

to

25

c

through an intake pipe (pipes)

27

. The intake noise silencer

28

is provided, at its surface portion on the side of the engine

2

, with an intake port

29

(

FIG. 2

or

4

), to which a flame arrester

30

is provided. Further, although these carburetors serve as air-fuel mixture supply means, in the case of the fuel injection type engine, for example, the carburetors man be replaced with air-amount adjusting means (throttle body) of a fuel injector. The carburetors

25

a

to

25

c

are arranged in this order from the upper portion in the state of the outboard motor being mounted to the hull, for example, as shown in

FIG. 1

, and in this meaning, the carburetor

25

a

is described herein as uppermost one.

As shown in

FIG. 6

, the interlocking mount member

26

is provided with a connection flange

32

having a shape aligned with the connection flange

24

of the intake manifold

23

. The connection flange

32

is formed with six screw holes

33

for fastening the three carburetors

25

a

to

25

c

at its peripheral portion by means of bolts. The connection flange

32

is further formed with three ports

34

to be aligned with the respective input pipes of the intake manifold

23

, and a pair of screw holes

35

are formed at opposite side portions of each port

34

, that is a pair of holes

35

are formed while the port

34

being positioned therebetween. Furthermore, a fastening members such as seating members

36

and

37

are integrally formed on an upper portion of the mounting member

26

.

The carburetors

25

a

to

25

c

and the interlocking mount member

26

are preliminarily assembled as the fuel supply apparatus

15

, and the connection flange

32

of the interlocking mount member

26

are mated with the connection flange

24

of the intake manifold

23

and six bolts

39

(

FIG. 1

) are inserted throughout the screw holes

35

of the interlocking mount member

26

, respectively, and then fastened together. Further, a plate-shape gasket, not shown, is disposed between these connection flanges

24

and

32

to ensure air-tight performance therebetween.

Throttle shafts

40

a,

40

b

and

40

c

are pivotally supported by the three carburetors

25

a,

25

b

and

25

c

for opening and closing throttle valves, not shown, incorporated in the carburetors

25

a

to

25

c,

respectively. Throttle levers

41

a,

41

b

and

41

c

are pivoted on right ends of the throttle shafts

40

a

to

40

c

to be rotatable together. Free ends of the throttle levers

41

a

to

41

c

are connected to a linkage link

33

(

FIG. 3

) so that a cam roller

43

provided for the lowermost throttle lever

41

c

abuts against a cam surface of a throttle cam

44

, which is supported by the cylinder head

9

, for example.

With reference to

FIG. 1

, an intermediate lever

46

is supported to the lower portion of the lowermost carburetor

25

c,

and the intermediate lever

46

, and the throttle cam

44

are interlocked by means of a throttle link

47

. Further, two cables

48

and

49

are coupled, at one ends thereof, to the intermediate lever

46

and, at other ends, to a throttle apparatus

100

disposed at a front portion of the outboard motor, i.e. hull side.

When the throttle apparatus

100

is operated, the intermediate lever

46

is rotated through the two cables

48

and

49

, and the rotation of the intermediate lever

46

is transmitted to the throttle cam

44

through the throttle link

47

to thereby rotate the throttle cam

44

. The throttle cam

44

then presses the throttle lever

41

c

(cam roller

43

) of the lowermost carburetor

25

c,

and the other throttle levers

41

a

and

41

b

are operated in association with the motion of the throttle lever

41

c

through the linkage link

42

. Accordingly, the throttle shafts

40

a

to

40

c

of the three carburetors

25

a

to

25

c

are simultaneously driven and rotated, and hence, the throttle valves accommodated in the respective carburetors are synchronously opened or closed to thereby control the engine output power. The three throttle levers

41

a

to

41

c

are usually urged by spring means

50

in a direction closing the throttle valve.

A starting operation assisting device (auto-choke device)

52

is fastened, by means of two bolts

53

, to the seating member

36

disposed to the upper portion of the interlocking mount member

26

. A speed reduction control device

56

is also mounted to the seating member

37

through a bracket

55

which is fixed thereto by screws

54

(FIG.

4

). For example, the starting operation assisting device

52

is disposed to an obliquely rear upper portion of the uppermost carburetor

25

a,

and the speed reduction control device

56

is disposed at a left side portion of the starting operation assisting device

52

side by side.

As such starting operation assisting device

52

, a known electromagnetic-type one using a solenoid will be arranged. As shown in

FIGS. 3

to

5

, an operation rod

57

is disposed so as to extend from the starting operation assisting device

52

and is connected, for example, to an input lever

59

(

FIG. 4

) of a cam shaft

58

supported to the upper portion of the intake pipe

27

. A choke cam

60

(

FIG. 3

) is mounted to the other end portion of the cam shaft

58

.

Three choke lever shafts

61

a,

61

b

and

61

c

for operating choke mechanisms respectively incorporated in the three carburetors

25

a,

25

b

and

25

c

are arranged vertically as viewed and supported by these carburetors, and a choke cam

60

abuts against a choke lever

62

(

FIG. 3

) integrally rotatably mounted to the uppermost choke lever shaft

61

a.

With reference to

FIG. 4

, Choke interlocking levers

63

a,

63

b

and

63

c

are mounted to other end side (engine side) of the respective choke lever shafts

61

a,

61

b

and

61

c

and mutually connected through an interlocking link

64

.

When the starting operation assisting device

52

is operated, the operation rod

57

is contracted from the extending position to thereby pull the input lever

59

and, hence, the choke cam

60

presses the choke lever

62

of the uppermost carburetor

25

a

and rotates the choke lever shaft

61

a.

The rotating motion of the choke lever shaft

61

a

is transmitted to the other two choke lever shafts

61

b

and

61

c

of the other two carburetors

25

b

and

25

c

through the choke interlocking levers

63

a

to

63

c

and the interlocking link

64

, whereby the choke mechanisms of all the carburetors

25

a

to

25

c

are simultaneously operated and the density of the air-fuel mixture is increased, thus easily starting the operation of the engine

2

.

On the other hand, the speed reduction control device

56

, which utilizes a pneumatic (hydraulic) damper, is also a known one, and as shown in

FIG. 4

, a damper rod

66

extending from the speed reduction control device

56

abuts against a tappet

68

provided for the front end portion of a damper lever

67

which is mounted to the left end portion, as viewed, of the throttle shaft

40

a

of the uppermost carburetor

25

a

to be integrally rotatable. The respective carburetors

25

a

to

25

c

have minimum degree of throttle opening in a state that the throttle levers

41

a

to

41

c

are rotated to the uppermost positions thereof, as shown in

FIG. 3

, and at that time, the damper lever

67

is also rotated to the uppermost position so as to push the damper rod

66

of the speed reduction control device

56

in the contracting direction.

As the degree of the throttle opening is increased by rotating downward the throttle levers

41

a

to

41

c

of the respective carburetors

25

a

to

25

c,

the damper lever

67

is also rotated downward and the damper rod

66

of the speed reduction control device

56

extends. In this operation, if the throttle closing operation is rapidly performed, the damper lever

67

is liable to be rapidly rotated upward by the urging force of the springs

50

of the carburetors

25

a

to

25

c.

However, according to the attenuation function caused by the speed reduction control device

56

, a resistance is caused against the contraction of the damper rod

66

, so that the closing speed for closing the throttle valve is delayed (made slow) and the engine stall can be hence prevented.

Incidentally, in the described starting operation assisting device

52

, the length (extension/contraction) of the operation rod

57

is adjusted by an adjustment nut

57

a

arranged to a base portion (on the side of the assisting device body) of the operation rod

57

so as to carry out a setting working for properly setting the initial position of the choke cam

60

with respect to the choke lever

62

. Further, in the speed reduction control device

56

, the tappet

68

disposed to the front end portion of the damper lever

67

is adjusted to thereby carry out a setting working for properly setting the initial positions of the damper rod

66

and the damper lever

67

.

In the fuel supply apparatus

15

of the outboard motor of the present invention of the structure mentioned above, the starting operation assisting device

52

and the speed reduction control device

56

are both mounted to the interlocking mounting member

26

and unitized as one assembly together with the three carburetors

25

a

to

25

c

as air-fuel mixture supply means. Therefore, the setting workings mentioned above can be carried out before the assembling of the fuel supply apparatus

15

to the engine

2

, and thus, it is not necessary to perform such setting workings on the assembling line of the engine

2

, resulting in the easy manufacturing of the outboard motor

1

with substantially no scattering of the engine performance which may be caused through the setting workings.

Furthermore, even if the fuel supply apparatus

15

is disassembled entirely from the engine

2

, the relative positional relationship of the starting operation assisting device

52

and the speed reduction control device

56

with respect to the carburetors

25

a

to

25

c

is not changed, so that it is not necessary to carry out the setting workings mentioned above every time of mounting or dismounting the fuel supply apparatus to or from the engine

2

. Accordingly, the operability or operational performance of the engine

2

can be remarkably improved.

Further, the intake pipes

27

are coupled to the carburetors

25

a

to

25

c

through the fastening of stud bolts

71

and nuts

72

provided for the carburetors

25

a

to

25

c

so as to project therefrom. The intake noise silencer

28

is mounted to the intake pipes

27

through a plurality of screws

73

. These intake pipes

27

and the intake noise silencer

28

may be detachably mounted to the carburetors

25

a

to

25

c

from the rear side thereof after the carburetors

25

a

to

25

c

have been mounted to the engine

2

.

That is, in the described embodiment, the mutually interlocked intake pipes

27

and the intake noise silencer

28

are mounted from the front side of the carburetors

25

a

to

25

c,

and at such mounting time, the engine

2

and other members are arranged so as not to interfere with the intake pipes

27

and the intake noise silencer

28

. According to such arrangement, since the intake pipe

27

and the intake noise silencer

28

can be mounted to the carburetors

25

a

to

25

c

which had already been mounted to the engine

2

, it is not necessary to mount these intake pipe and silencer in the initial assembling stage. Accordingly, the interlocking mount member

26

, the carburetors

25

a

to

25

c,

the starting operation assisting device

52

and the speed reduction control device

56

, assembled in one small unit, can be easily mounted to the engine

2

, whereby the packaging, transportation, maintenance and the like working of the fuel supply apparatus

15

can be made easy and improved.

It is to be noted that the present invention is not limited to the described embodiment and many other changes and modifications may be made without departing from the scopes of the appended claims.

Number	Name	Date	Kind
4126303	Yanagisawa et al.	Nov 1978
5524596	Nakai et al.	Jun 1996

Fuel supply apparatus of outboard motor

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (2)