Outboard motor

Abstract

An outboard motor having a grommet mounted on a lower cover is disclosed. The grommet is positioned outward from an area directly under a surface in which an upper cover and lower cover meet as viewed from above. A presser cover for pressing the upper half of the grommet expands in the lateral direction and has on the lower end portion a first concavity that opens in the downward direction and conforms to the external shape of the grommet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of the outboard engine according to the present invention;

FIG. 2 is a rear view of the outboard engine shown in FIG. 1;

FIG. 3 is an exploded perspective view of the lower cover shown in FIG. 1;

FIG. 4 is an enlarged view of the area around the rear bracket shown in FIG. 2;

FIG. 5 is an enlarged view of the right cover half, grommets, and front bracket of the lower cover shown in FIG. 3;

FIG. 6 is a perspective view of the front bracket shown in FIG. 5;

FIG. 7 is a front view showing a state in which the front bracket and grommets have been mounted on the lower cover;

FIG. 8 is a view as seen in the direction of arrow 8 of FIG. 7, showing in front elevation the state in which the grommets have been mounted;

FIG. 9 is a view as seen in the direction of arrow 9 of FIG. 7, showing in side elevation the state in which the grommets have been mounted; and

FIG. 10 is a view showing a state in which two outboard motors are mounted in parallel.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1 and 2, an outboard engine 1 has an engine 2 covered by an engine cover 3.

The engine cover 3 is composed of an upper cover 4 that covers the upper portion of the engine 2, and a lower cover 5 that covers the lower portion of the engine 2. An engine compartment 6 is partitioned by the upper and lower covers 4 and 5.

The engine 2 is a multi-cylinder four-stroke engine provided with substantially horizontally moving pistons and a vertically disposed crankshaft. The engine 2 is provided with a cylinder block 7, a cylinder head 8 disposed in the rear portion of the cylinder block 7, and a crankcase 9 disposed in the front portion of the cylinder block 7. The cylinder block 7 has a plurality of cylinders 7a. The cylinder head 8 has a plurality of combustion chambers 8a corresponding to the cylinders 7a. The reference numeral 8b is a camshaft. The crankcase 9 houses a vertically disposed crankshaft 9a.

An intake silencer 10 is disposed from the front portion of the right side of the crankcase 9 across the forward portion. A power generator (ACG) 11 is disposed above the engine 2.

The engine 2 is supported by a mounting case 12. The reference numeral 12a is an oil pan.

A crankshaft 9a is connected to a downwardly suspended drive shaft 13. The drive shaft 13 passes through the inside of an extension case 14 that is disposed below the bottom cover 5, and is connected to a gear transmission mechanism 15a inside a gear case 15 that is mounted on the lower end of the extension case 14.

The gear transmission mechanism 15a transmits the drive force of the drive shaft 13 to a horizontal driven shaft 15b. The rear end portion of the horizontal driven shaft 15b protrudes rearward from the gear case 15. A propeller 16 is mounted on the rear end portion of the horizontal driven shaft 15b. The propeller 16 is driven by the motive force of the engine 2. The outboard motor 1 produces forward or rearward propulsion by switching the direction of the propeller 16 with the aid of a pair of dog clutches.

A stem bracket 17 for mounting the outboard motor 1 on the stem is mounted on the front of the outboard motor 1 by way of a swivel case 18. The swivel case 18 is supported by mounting rubbers 18a and 18b.

Exhaust directed downward from the cylinder head 8 passes through a main exhaust channel 12d (FIG. 3) formed in the mounting case 12 and a main exhaust pipe 19a disposed downstream from the main exhaust channel 12d; subsequently passes through the interior of the lower cover 5, the extension case 14, and the gear case 15; and is then exhausted from the center of the propeller 16 into the water, as indicated by the arrow a.

A portion of the exhaust passes through a sub-exhaust pipe 19b adjacent to the primary exhaust pipe 19a, and is exhausted in the rearward direction of the outboard motor 1 as indicated by the arrow b.

A water test port 20 for visually confirming whether cooling water is flowing to the engine cooling unit is formed in the lower cover 5, and a portion of the cooling water is discharged in the rearward direction of the outboard motor 1.

An ignition plug 50 can be serviced by opening and closing a lid 51a that covers a notched portion 51 formed in the right cover half 32 (FIG. 2) of the lower cover 5 and removing and inserting the ignition plug.

The upper cover 4 is a resin molded article. The lower cover 5 is composed of divided left and right cover halves 31 and 32, and is a resin molded article. The left and right cover halves 31 and 32 are brought together and joined.

The structure of the lower cover 5 is described below with reference to FIG. 3.

The upper halves 31a and 32a of the left and right cover halves 31 and 32 are longer in the forward and rearward direction than the lower halves 31b and 32b. In other words, the front portions 31d and 32d of the upper halves 31a and 32a extend further in the forward direction than do the front portions 31c and 35c of the lower halves 31b and 32b.

The left and right cover halves 31 and 32 have an engaging groove portion 31e (in the diagram, the engaging groove portion of the right cover half 32 is hidden and cannot be seen) formed with bilateral symmetry at substantially the border between the upper halves 31a and 32a and the lower halves 31b and 32b on the inner surface of the left and right cover halves. When the left and right cover halves 31 and 32 are brought together and joined, a seal member 12g mounted around a flange portion 12f of the mounting case 12 is fitted into the engaging groove portion 31e to seal the space between the cover halves 31 and 32 and the mounting case.

The mounting case 12 is provided with a drive shaft vertical through-hole 12c, a hole 12b though which a shift rod inside a swivel shaft vertically passes, an engine-mounting flange 12e, an oil return aperture in an oil pan 12a, and a primary exhaust channel 7d.

The front bracket that connects the upper space between the left and right cover halves, the grommet that holds and seals the cables, and the presser cover body are described later.

Notched longitudinal engaging concave portions 31g and 32g are formed in the upper half of the rear portions 31f and 32f of the left and right cover halves 31 and 32. Mounting bosses 31h and 32h are disposed in the upper portions of the engaging concave portions 31g and 32g. The mounting bosses 31h and 32h have mounting holes 31i and 32i.

The upper rear portions of the left and right cover halves 31 and 32 are mounted on the engine side by way of a rear bracket 23. The sub-exhaust pipe 19b and a pipe 20a of the water test port 20 are positioned inside the lower cover 5.

The rear bracket 23 has a U-shaped flat main body 24, as shown in FIGS. 3 and 4. The flat main body 24 is exposed in the center portion of the rear surface of the lower cover 5. Support arms 24a and 24a curved in the form of a dogleg to the left and right are disposed inside the flat main body 24. The support arms 24a and 24a are fixed with the aid of bolts 25 and 25 to mounting eyes 8b and 8b, which are formed so as to protrude to the left and right of the cylinder head 8.

In the example shown in the diagram, the rear bracket 23 is mounted on the engine side, but the rear bracket may be mounted on the rear surface of the mounting case 12.

Concave grooves 31j and 32j are formed to the left and right of the main body 24 of the rear bracket 23. The edges of the engaging concave portions 31g and 32g of the left and right cover halves 31 and 32 are fitted into the concave grooves 31j and 32j.

Erect pieces 24b and 24b are disposed to the left and right on the upper portion of the rear bracket 23. Nuts, which are not shown, are embedded in the erect pieces 24b and 24b. The left and right mounting bosses 31h and 32h, which are disposed in protruding fashion in the vicinity of the joined portion of the left and right cover halves 31 and 32, are superimposed on the left and right erect pieces 24b and 24b, and bolts 26 and 26 are inserted by way of the mounting holes 31i and 32i and are screwed into the embedded nuts of the erect pieces 24b and 24b. The joined portion of the left and right cover halves 31 and 32 is thereby connected to the rear bracket 23.

A mounting hole 24c bored into the lower end of the bracket main body 24, and a mounting hole 31k formed in the lower portion of the engaging concave portions 31g and 32g (see FIG. 3; the right cover half 32 also has a mounting hole in the same manner, but the mounting hole is not visible in the diagram) are superimposed onto each other, and a decorative bolt is inserted and screwed into a nut 24d (see FIG. 3) disposed inside the main body 24 to connect the assembly.

Therefore, the component exposed behind the upper cover 4 and lower cover 5 is only the main body 24 of the rear bracket 23. The portions mounted on the engine 2, the portions mounted on the rear bracket 23 of the left and right cover halves 31 and 32, and other mounted portions are hidden by the covers.

In FIG. 4, an operation arm 27 is pivotably mounted on the rear bracket 23. The operation arm 27 has an inverted U-shaped latch post 27a. The latch post 27a engages a hook 2b when operated by a handle 27b, and locks the closed state of the upper cover 4 against the lower cover 5. The hook 2b is disposed on the upper cover 4.

The cover halves 31 and 32 have holding portions 31r and 32r, as shown in FIG. 3, and are held by an engine-side holder (not shown).

The sub-exhaust pipe 19b opens on the rear surface of the rear bracket 23. The water test port 20 also opens on the rear surface of the rear bracket 23 in the same manner. The sub-exhaust pipe 19b leads to a sub-exhaust channel 12h (FIG. 4) formed in the mounting case 12.

The mounting structure of the front bracket 43 for connecting the upper front portions of the left and right cover halves 31 and 32, the presser cover 38, and the grommet 42 that brings the cables together are described next with reference to FIG. 3 and FIGS. 5 to 9.

The upper edge of the front portion 32d of the upper half portion 32a of the right cover half 32 has a lower profile so as to accommodate the presser cover 38, and forms a concave conduit portion 36 that extends in the forward and rearward directions.

A side wall 36a of the conduit portion 36 is curved, opens in the rearward direction in the form of a half cylinder, and has a shape that expands in the lateral direction.

The upper edge of the conduit portion 36 has a narrow shelf portion 36b that is curved inward, and an erect rim 36c that stands erect at the inner edge of the shelf portion 36b. The rear end of the conduit portion 36 is L-shaped as viewed from the side. The upper edge of the rear end portion continues to a shelf surface 32m, which is a joining surface between the right cover half 32 and the lower edge of the upper cover 4. The shelf surface 32m has an erect rim 32n that stands erect at the inner edge of the shelf surface 32m. The erect rim 32n is in contact with the inner surface of the lower end of the upper cover 4.

An extended bottom piece 36d that extends inward is formed on the lower surface of the front portion of the conduit portion 36, and a mounting hole 36e is provided in the base portion of the extended bottom piece 36d.

A plate-shaped support portion 37, which internally houses a nut 37a, is disposed on the front end of the upper half portion 32a behind the conduit portion 36 of the right cover half 32.

The presser cover 38 has an integrally formed expanding portion 39 that expands outward to the side of the cover main body 38a extending in the forward and rearward directions. The front portion 38b of the cover main body 38a is curved inward, as shown in FIG. 8. The front end 38c is substantially flat in the same manner as the front surface of the engine cover of the outboard motor.

The front portion 39a of the expanding portion 39 protrudes considerably outward as viewed from above, and the side portion 39b merges with the rear portion of the cover main body 38a while gradually expanding in the rearward direction. The cover main body 38a of the presser cover 38 has a shelf surface 38d on the upper end thereof. The shelf surface 38d has an erect rim 38e that stands erect at the inner edge thereof. The shelf surface 38d and erect rim 38e conform to the shelf surface 32m and the erect rim 35n.

Mounting eyes 40, 40 in which mounting holes 40a, 40a are respectively formed are provided in the forward and rearward end portions of the erect rim 38e.

A semicircular open portion 41 is formed in the front portion 39a of the expanding portion 39. The semicircular open portion 41 has a shape that conforms to the upper half portion of the grommet 42 shown in FIG. 5.

The grommet 42 is composed of rubber, synthetic rubber, or another sealing material, and the overall shape is a cylindrical shape that is long in the forward and rearward directions. The grommet 42 has a plurality of cable insertion holes 42a composed of round and square holes that pass completely through the grommet in the axial direction. A plurality of seal lips 42b is provided in protruding fashion in the form of a ring in the external peripheral portion of the grommet 42. The grommet 42 provides support so that cables can be brought in and out of the engine compartment by way of the cable insertion holes 42a. Examples of the cables include an engine control cable for opening and closing a throttle valve, a drive control cable for switching between forward and rearward propulsion, a power supply cable, signal transmission cables, and a fuel supply tube.

The front bracket 43 has an insertion hole 43b for a swivel shaft formed in a bracket main body 43a in the form of a shelf board, and a power cord insertion hole 43c for a hydraulic tilt and trim cylinder device, as shown in FIG. 6.

The bracket main body 43a has an erect wall 43d that is curved as viewed from above and is formed in the front end of the bracket main body. An operation arm 21 for engaging and locking the upper and lower covers 4 and 5 (FIG. 1) is supported on a support shaft 43e mounted on the front portion of the erect wall 43d. A handle 21a of the operation arm 21 is pivotably mounted on the support shaft 43e. An inverted U-shaped lock post 21b interlocks with a pawl 2a disposed on the lower portion of the center portion of the upper cover 4 (FIG. 1) by operating the handle 21a, and locks the upper cover 4 and lower cover 5.

A receiver arm 44 that supports the lower half portion of the grommet 42 extends from the right side of the front bracket 43. The receiver arm 44 has a semicircular upward-facing concave portion 44a as viewed from the front. The semicircular concave portion 44a has a shape that conforms to the lower half portion of the grommet 42. The inner surface of the receiver arm 44 has a plurality of grooves 44b set at a distance from each other in the axial direction.

The receiver arm 44 has a mounting hole 44c formed in the outer end rear portion of the receiver arm. A mounting hole 44d is formed in the outward portion of the bracket main body 43a in the base portion side of the receiver arm 44.

The bracket main body 43a has a substantially triangular rib wall 43f formed in the rear portion of the right side of the bracket main body. A mounting screw hole 43g that faces in the width direction of the outboard motor is formed in the rib wall 43f.

A mounting portion 43h curved in the rearward direction is formed in the right-side end portion of the erect wall 43d of the front bracket 43. The mounting portion 43h has a screw hole.

The front bracket 43 is mounted in the space between the upper portions of the front surfaces of the left and right cover halves 31 and 32, as shown in FIG. 3.

The outer end portion of the receiver arm 44 is mounted on the conduit portion 36 by inserting a stepped bolt 60 into the mounting hole 44c and the mounting hole 36e formed in the conduit portion 36 of the right cover half 32, and screwing the stepped bolt 60 into the nut 39c disposed in the expanding portion 39 of the presser cover 38 that has been placed on the conduit portion 36. The base portion of the receiver arm 44 is mounted on the presser cover 38 by inserting a stepped bolt 61 into the mounting hole 44d and the mounting hole 40a formed in the front mounting portion 40 of the presser cover 38, and tightening the bolt.

The rear end portion of the presser cover 38 is mounted on the right cover half 32 by inserting a bolt 62 into the mounting hole 40a of the front mounting portion 40, and screwing the bolt 62 into a nut 37a of the support portion 37 of the right cover half 32. A bolt 63 is furthermore inserted into a through-hole 35p (FIG. 7) provided in the lower front portion of the right cover half 32, the bolt 63 is screwed into the mounting screw hole 43g formed in the rib wall 43f of the front bracket 43, and the right cover half 32 and the front bracket 43 are fastened together.

The front bracket 43 also has a rib wall 43i on the side opposite of the rib wall 43f, as shown in FIG. 7. The rib wall 43i is fastened with the aid of a bolt 64 to the mounting portion 31q provided in the left cover half 31. The mounting portion 43h of the front bracket 43 is mounted with the aid of a bolt 65 to the mounting portion 31p formed in the upper portion of the left cover half 31.

In this manner, the left and right cover halves 31 and 32 are connected by way of the front bracket 43. When the presser cover 38 is mounted on the receiver arm 44 of the front bracket 43, a circular hole is formed that sandwiches the grommet 42 between the semicircular open portion 41 of the presser cover 38 and the semicircular concave portion 44a of the receiver arm 44.

The grommet 42 has a plurality of seal lips 42b in the form of a ring disposed in protruding fashion on the external periphery of the grommet. The seal lips 42b engage a plurality of semicircular grooves 44b formed in the receiver arm 44, the grommet 42 is reliably held by the presser cover 38 and the front bracket 43, and exceptional sealing characteristics can be provided by the plurality of seal lips 42b and the plurality of grooves 44b.

As shown in FIGS. 8 and 9, the grommet 42 is positioned outward from the area directly under the surface in which the upper cover and lower cover meet as viewed from above. The upper surface of the grommet 42 is essentially positioned on the upper edge, as indicated by the reference symbol A, of the right cover half 32 of the lower cover 5 that is in contact with the lower edge of the upper cover 4, i.e., is essentially positioned on the shelf surface 38d of the presser cover 38, which is in the same plane as the upper edge A.

Therefore, a large space can be secured below the grommet 42 because the upper surface of the grommet 42 is positioned above the lower edge of the upper cover 4.

For this reason, a plurality of outboard motors, e.g., two outboard motors 1 and 1, can be connected by a connecting rod 70 when the motors are disposed in parallel as shown in FIG. 10. The connecting portion 71 of the connecting rod 70 is positioned below the grommet 42 of one of the outboard motors 1, and the grommet 42 is positioned above the lower cover 5 as described above. Therefore, the degree of freedom in disposing the connecting portion 71 of the connecting rod 70 is improved. The options for selecting a commercially-available connecting device are thereby increased, and since a space is obtained below the grommet 42, the work for connecting a plurality of outboard motors is facilitated, and the degree of freedom for laying out, disposing, or otherwise positioning cables is further improved.

Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims

1. An outboard motor comprising: an engine;an engine cover comprised of an upper cover and a lower cover that define an engine compartment for accommodating the engine;cable introduction portions disposed in the lower cover; anda grommet for sealing the cable introduction portions,

2. The outboard motor of claim 1, wherein the lower cover has a notched concavity formed to accommodate the presser cover, and a second concavity opened in an upward direction so as to sandwich the grommet against the first concavity.

3. The outboard motor of claim 2, wherein the lower cover is comprised of left and right cover halves, and the second concavity of the lower cover is comprised of a receiver arm disposed on one side of a front bracket that links a space between the upper portion of the right and left cover halves.