Outboard engine

FIELD OF THE INVENTION

[0001] The present invention relates to an outboard engine which allows an easy tilt-up operation relative to a boat.

BACKGROUND OF THE INVENTION

[0002] An outboard engine is attached to a stern of a boat through a stern bracket, so that the outboard engine may be steered and moved up and down (tilt-up operation).

[0003] Tilt-up operation is performed by vertically pivoting or rotating the outboard engine, attached to a stern, about a tilt axis, when, for example, the boat moves through shallow water or needs to avoid driftwood. A conventional outboard engine structure is known from, for example, Japanese Patent Laid-Open Publication No. SHO-57-27199 and SHO-59-15800 for allowing a tilt-up operation.

[0004] The outboard engine in Japanese Patent Laid-Open Publication No. SHO-57-27199 includes a lever for performing the tilt-up operation. Because the structure of the outboard engine is such that the lever comprises a separate unit that juts upward from a top surface of a cover of the outboard engine, the aesthetics of the outboard engine is compromised. Additional components lead to increased costs.

[0005] The outboard engine in Japanese Patent Laid-Open Publication No. 59-15800 has a recess in the rear portion of an upper engine cover, and the opening of this indentation faces toward the back of the outboard engine and serves as a handle for tilt-up operation. This structure makes the tilt-up operation difficult, when the outboard engine is large, because the distance between the steer of the boat (front portion of the outboard engine) and the lever is too long.

SUMMARY OF THE INVENTION

[0006] It is therefore an objective of the present invention to provide an outboard engine that facilitates easy tilt-up operation while avoiding unnecessary cost increases.

[0007] According to an aspect of the present invention, there is provided an outboard engine comprising: an engine; an engine cover for covering the engine and its peripheral equipment; an under cover mounted to the bottom of the engine cover; an extension case mounted to the bottom of the under cover; a gear case having a screw and placed in the lower part of the extension case; and a recess formed on a part of the top surface of the engine cover to provide a grip for holding the top portion of the engine cover by hand.

[0008] In the outboard engine thus arranged, it is possible to perform the tilt-up operation by inserting fingers into the grip recess to get a hold on the outboard engine, lift the outboard engine, which includes the engine cover, about a tilt axis. When the outboard engine is large, both hands may be inserted into the grip recess for the tilt-up operation.

[0009] The grip recess is placed in the rear part of the top of the engine cover, thereby allowing easy rotation of the outboard engine with a tilt operation.

[0010] The engine cover comprises an engine cover body and a separate top cover, which is coupled onto the top of the engine cover body to form a single unit. The grip recess is formed on the top cover. When the outboard engine is large, the grip recess can be formed more easily, the engine cover with the grip recess can be manufactured more easily, and the entire structure may be simplified, when the top cover comprises a separate unit from the engine cover, the grip recess is formed on the top cover, and the top cover is coupled to the engine cover.

[0011] The grip recess comprises an opening formed on the top cover, a curved guide surface on the lower part of the opening, and rounded ends at both ends of the opening to ensure easy and sure insertion of a hand into the grip recess. The curved guide surface facilitates smooth hand insertion. The rounded ends enhance the strength of the grip recess.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] A preferred embodiment of the present invention will be described in detail herein below, by way of example only, with the reference to the accompanying drawings, in which:

[0013]
FIG. 1 is a side view illustrating an outboard engine, as attached to the steer of a boat, embodying the present invention;

[0014]
FIG. 2 is an enlarged cross sectional view illustrating the cross section of the top part of the outboard engine in FIG. 1;

[0015]
FIG. 3 is a top plan view of the top cover with the grip recess shown in FIG. 2;

[0016]
FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. 3;

[0017]
FIG. 5 is a top plan view illustrating the main engine cover unit with the top cover removed;

[0018]
FIG. 6 is a view from an angle in which the top cover, engine cover body, and air intake guide in FIG. 2 have been taken apart;

[0019]
FIG. 7 is a cross sectional view illustrating the top cover, engine cover body, and air intake guide, shown in FIG. 6, as assembled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0020] Referring to FIG. 1, the outboard engine 1 comprises a top engine cover 2, an under cover 3 placed in the lower part of the engine cover 2, an extension case 4 extending from the lower part of the under cover 3, and a gear case 5 placed in the lower part of the extension case 4. Screws 6 are placed in the back part of the gear case 5. This outboard engine 1 is attached to the boat through a stern bracket 7 attached to a steer B. The outboard engine 1 moves up and down about a tilt axis 7a.

[0021] Referring to FIG. 2, the outboard engine 1 includes an engine 8. The engine 8 includes a cylinder block 9, a crank case 10 placed in the front part of a skirt 9c of the cylinder block 9, a cylinder head 11 placed in the rear part of the cylinder block 9, and a cylinder head cover 12 placed in the rear part of the cylinder head 11. The engine 8 comprises a vertical engine whose crankshaft 13 is disposed vertically. The cylinder block 9 includes a plurality of horizontal cylinders 9a (in the illustrated example, three cylinders) horizontally laid in parallel relation to each other. Each cylinder 9a has a piston 9b in it. Each piston 9b is linked to a crankshaft 13 through a connecting rod. Cylinder head 11 has a plurality of combustion chambers 11a corresponding to the cylinders 9a. The engine 8 in this particular example embodiment is a V-shaped 6-cylinder engine.

[0022] In the rear part of the cylinder head 11 is an intake manifold 14 that extends in the up and down directions. An air intake guide 15 is placed at the rear part of the intake manifold 14.

[0023] Camshaft pulley 16 is placed in the upper part of the cylinder head 11. Guide pulley 17 is placed in the upper part of the rear of the cylinder block 9. A first driver pulley 18, driven by the crankshaft 13, is placed in the upper part of the skirt 9c. Timing belt 19 links a camshaft pulley 16 and the first driver pulley 18. A camshaft not in this FIG. is driven with the rotation of the crankshaft 13 and through the first driver pulley 18, timing belt 19, and camshaft pulley 16.

[0024] Generator (ACG) 20 is attached to the upper front surface of the crank case 10, which comprises the front part of the engine. Driven pulley 21 for driving the generator is placed on the top surface of the generator 20. Second driver pulley 22 is placed on the top part of the crankshaft 13. The second driver pulley 22 and the driven pulley 21 are linked by a driver belt 23. Generator 20 is driven by the rotation of crankshaft 7 through the second driver pulley 22, driver belt 23, and driven pulley 21.

[0025] A box-shaped intake muffler 24 is placed above the belt pulley structure, which is placed above the engine 8, in the middle to rear part of the belt pulley structure. Box-shaped front half 24a of the intake muffler 24 is placed on the top part of the aforementioned second driver pulley 22. A front half 24b of the intake muffler 24 is shaped like a shelf and is located on the top part of the driven pulley 21 of the generator 20. The front portion 24b, in the shape of a shelf, is formed as a separate unit from the box part and joined to the box part.

[0026] The intake muffler 24 includes an intake connector duct 24c in the rear. The intake connector duct 24c is linked to grommet 26 in the upstream portion of the intake path of a throttle valve 25 placed in the upper rear part of engine 8.

[0027] In the Figure, reference numeral 27 designates a control cable for controlling the throttle valve. The control cable 27 extends along one side of the top surface of the intake muffler 24 toward the front, goes down from the front portion 24b and through the crankcase 10 and extends to the front of the outboard engine 1. Reference numeral 28 denotes an oil filter, and reference numeral 29 designates an exhaust pipe.

[0028] Engine cover 2 covers the engine 8 and some peripheral equipment. Engine cover 2 includes a plurality of slit 30 for intake which are formed in the front and lower part of the engine cover 2. Intake through the slit 30 passes through an intake opening 31 and passes through cooling paths 32 and 33 to cool the generator 20. The cooling paths 32 and 33 comprise a moisture separator.

[0029] Top cover 40 is placed in the upper rear part of engine cover 2. Grip recess 43 is formed toward the front part of the top cover 40, as shown in detail in FIGS. 3 and 4.

[0030] When viewed from the top, the top cover 40 forms a long plate that extends from front to back in FIGS. 3 and 4. A rear part 40a of the top cover 40 is wide in the right-left directions, while a front part 40b of the top cover 40 is narrow, and a front edge part 40c of the top cover 40 is cylindrically shaped.

[0031] Top cover 40 includes a shallow recess 40d at the midpoint with respect to the front and back of the top cover 40. The recess 40d is wider in the back half with respect to the midpoint of top cover 40 and narrower in the front part with respect to the midpoint. Two rear intake slits 41 and 42, which penetrate in the up and down directions, are formed in the rear part of the recess 40d. These rear slits 41 and 42 extend along the width of the top cover 40 and are separated from each other in the front and back directions. Front intake slits 42 and 42, which penetrate in the front/back direction, are formed in the front part 40b of the top cover 40. These front slits 42 and 42 extend along the width of the top cover 40 and are separated from each other in the back and front direction.

[0032] The rear slits 41 and 41 include a border 41a that hangs down as shown in FIG. 4. The front slits 42 and 42 include a border 42a that hangs slightly below to enhance strength around the slits.

[0033] Top cover 40 includes a grip recess 43 provided at a longitudinally central part and extending laterally thereof. The recess 43 is sized in length and width such that it allows operator's four fingers from a pointing finger to a little finger pulled together to be fitted thereinto.

[0034] Grip recess 43 includes a back edge part 43a at the same level as the surface of the recess 40d, as shown in FIG. 4. The grip recess 43 also includes a bottom surface 40b (which acts as a guide when a person inserts his or her fingers), which curves from the front edge 43a down toward the front. Both ends of the bottom surface 43b are connected to the surface of the recess 40d through right and left sidewalls 43c.

[0035] The front edge part of the bottom surface 43b of the grip recess 43 includes a cut-out slit 43d, which opens in the front and back direction. This slit 43d is where the fingers go in. The upper edge of the slit 43d continues to a front part 40e of the recess 40d. Beading 44 is formed at the top edge of the slit 43d. The beading 44 extends across the entire front edge of the grip recess 43 to enhance its toughness.

[0036] An attachment boss 45 is formed on the lower surface of the front edge part 40c of the top cover 40. Two attachment bosses 46 and 46 are formed at right and left of the lower surface in the front part of the grip recess 43. Support ribs 47 and 47 hang down and extend in the front-back directions where the bosses 46 and 46 are. Attachment bosses 48 are placed at right and left and at the center of the back lower surface of the top cover 40. A support rib 49 hangs down and extends in the front and back direction where this boss 48 is.

[0037]
FIG. 5 shows a top view of the engine cover 2, when the top cover is removed.

[0038] A cover main unit 50 of the engine cover 2 includes a rear part 50a, which is wider in width, and a front part 50b, which is narrower. The cover main unit 50 also includes a top surface 50c and a recess 51 (see FIG. 6), which is lower than the top surface 50c and is formed between the center point of the top surface 50c and the rear part 50a.

[0039] The recess 51 has two openings 52 on right and left of a bridge 52a, which extends in the front and back directions. Each of the stays 52b and 52b links the bridge 52a and the inner perimeter of the right and left openings 52 and 52, respectively. Attachment bosses 53 are formed on the rear part of the bridge 52a and the right and left stays 52b and 52b, respectively. A hole 54 is formed at the center of the bridge 52a to position the rubber bush 58, as shown in FIG. 7. The rubber bush 58 supports the top cover 40. Two attachment bosses 55 and 55 are placed in the front part of the recess 51. An attachment boss 56 is placed in the front edge part.

[0040]
FIG. 6 shows an exploded view at an angle on how the intake guide 15 in FIG. 2, top cover 40, engine cover 2, and the cover main unit 50 are attached.

[0041] Intake guide 15 is coupled to the top cover 40 through the cover main unit 50. The intake guide 15 forms a thin, reverse-L shaped box when seen from the side, as in FIG. 2. The frame 50b is formed around the opening 50a of the top shelf part 50a that extends toward the front. Three attachment bosses 15c are placed in the rear inside of the frame 50b at the center and right and left. An attachment boss 15d is placed at the center in the front part.

[0042] The shelf part 15a of the intake guide 15 is aligned to the lower surface of the recess 51 of the engine cover body 50, while the top cover 40 is placed on top of the recess 51.

[0043] The three attachment bosses 48 on top cover 40 are aligned with the three attachment bosses 53 on the engine cover body 50. At the same time, the attachment bosses 53 are aligned to the three attachment bosses 15c on the intake guide 15. Screws 60 couple the top cover 40, engine cover body 50, and the shelf part 15a of the intake guide 15. Intake guide 15 is attached to the engine cover body 50 by coupling the rubber bush 58 to the opening 54 in the engine cover body 50, and attaching the attachment boss 57 of the engine cover body 50 to the attachment boss 15d of the intake guide 15 with screws 60.

[0044] Top cover 40 is attached to the engine cover body 50 by attaching the three attachment bosses 45, 46 and 46, which are placed between the front part and the front edge of the top cover 40, to the attachment bosses 56, 55 and 55 placed in the recess 51 of the engine cover body 50.

[0045]
FIG. 7 shows the top cover for the intake guide 15 attached to the engine cover main until 50.

[0046] Top cover 40 is attached to the rear top surface of the engine cover body 50 through the six attachment bosses 45, 46 and 48, as in FIG. 3. Ribs 47 and 49 around these attachment bosses ensure strong attachment to the engine cover body 50. Engine cover body 50 is strong, because the top cover 40 is attached in the recess 51, the opening 52 is surrounded by the frame 51a, and the attachment is to the shelf part 15a of the intake guide 15, which includes the frame 15b.

[0047] In order to move the outboard engine 1 up and down about the tilt axis 7a, a person inserts fingers of his or her hand H into the grip recess 43 and pushes the fingertips into the slit 43b, as FIG. 7 shows. Because the lower surface 43b is curved, the person can insert the fingers smoothly. The beaded top edge 44 of the slit 43d protects the fingers and enhances strength.

[0048] Thus shown, a person can rotate the outboard engine 1 about the tilt axis 7a as though he or she is lifting the outboard engine, by using as a handle the grip recess 43, formed at middle to front half of the top cover 40, by inserting his or her fingers into the recess 43 and holding onto it.

[0049] Space S is left between the rear part of the top cover 40 and the rear part of the engine cover body 50, as well as between the peripheral of the top cover 40 and the engine cover body 50, if needed. The space S allows air intake into the intake guide 15. The air coming in from this guide is introduced into the combustion chambers 11a through the intake muffler 24, throttle valve 25, and intake manifold 14, as FIG. 2 shows.

[0050] In addition to this embodiment, the grip recess 43 can also be formed directly on the top surface of the engine cover 2. It is also possible to place a handle across the width of the grip recess 43.

[0051] The present disclosure relates to the subject matter of Japanese Patent Application, No. 2001-035209, filed Feb. 13, 2001, the disclosure of which is expressly incorporated herein by reference in its entirety.

Outboard engine

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CPC

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Abstract

Description

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Priority Claims (1)