EP1316500B1

EP1316500B1 - Outboard motor

Info

Publication number: EP1316500B1
Application number: EP20020026473
Authority: EP
Inventors: Arai Sanshin Kogyo K.K. Hideto; Kitajima Sanshin Kogyo K.K. Kazuyuki; Tsujii Yamaha Hatsudoki K.K. Eiichiro
Original assignee: Yamaha Marine Co Ltd
Current assignee: Yamaha Marine Co Ltd
Priority date: 2001-11-29
Filing date: 2002-11-27
Publication date: 2006-07-26
Anticipated expiration: 2022-11-27
Also published as: EP1316500A3; EP1316500A2

Description

The present invention relates to an outboard motor comprising a propulsion unit with an engine.
An outboard motor, in general, comprise: a propulsion unit supported by a hull via a swivel bracket so that the propulsion unit can be rotated with respect to the swivel bracket to steer the boat; an engine disposed in a cowl of the propulsion unit for generating a propulsive force; and a fuel tank for supplying fuel to the engine. A propeller arranged at a lower rear part of the propulsion unit and driven by the engine via a drive shaft and a propeller shaft. Such an outboard motor is known from EP-A-0 902 174.
In such a small outboard motor, when the engine and the fuel tank are housed in a small space in a cowl of the propulsion unit, the fuel tank needs to be firmly secured because it is heavy in weight. Also, in some fitting structures, it is difficult to provide sufficient capacity to the fuel tank.
Furthermore, in a small outboard motor, when an engine and a fuel tank is housed in a small space within a cowl of a propulsion unit, the engine may be cooled by outside air containing water and adversely affected thereby, depending upon the fuel tank arrangement structure.
Some outboard motors are equipped with an oil inspection device which enables visual observation of oil reserved in an oil reservoir of the engine.
Conventionally, the engine oil level is checked to see whether or not the engine oil is at a proper level with the device of an inspection window type, a stick type, a screw type or the like.
For a small outboard motor, a stick type device or a screw type device are too complicated in structure. An inspection window type device is preferred due to the simplicity in structure, but needs to be installed in such a position that it can be easily observed when the cowl is removed. Additionally, the oil inspection device needs to be designed such that it can be used to check the degree of contamination as well as the amount of oil.
Some propulsion units of such outboard motors can be rotated with respect to the swivel bracket so that the running direction of the boat may be changed without changing the rotational direction of the propeller, and can be tilted up and down.
Such a propulsion unit is rotated with respect to the swivel bracket between forward and reverse positions with a carrying handle. Thus, when the propulsion unit is tilted up and down when the carrying handle is on the hull side, the carrying handle interferes with a member on the hull for attaching the propulsion unit to the hull such as a fixing screw mechanism and gets a damage which may impair the appearance and durability thereof.
It is an objective of the present invention to provide an outboard motor comprising a propulsion unit with an engine which is compact in structure.
According to the present invention, said objective is solved by an outboard motor comprising a propulsion unit with an engine having a starter and a fuel tank for supplying fuel to the engine, said starter comprises a rotational center shaft, wherein the fuel tank has an end secured to said rotational center shaft of the starter.
According to a preferred embodiment, the fuel tank has an extended portion overhanging the starter, and the starter is covered with a starter cover having a communication hole for introducing air, and the fuel tank is arranged such that the communication hole is covered with the extended portion of the fuel tank.
According to a preferred embodiment, the starter cover has an extension forming a partition between a fuel tank room receiving said fuel tank and an engine room receiving said engine, and said communication hole is provided for communicating the fuel tank room and the engine room, so that outside air introduced into the fuel tank room can be introduced into the engine room therethrough.
According to a preferred embodiment, a gap is provided between the fuel tank housed in the fuel tank room and the starter cover, and air can be introduced into the gap.
According to a preferred embodiment, fuel tank has a tank capacity section formed by extending a part thereof and located above the starter.
According to a preferred embodiment, an oil inspection device is provided for visual observation of oil reserved in an oil reservoir in the engine.
According to a preferred embodiment, the oil inspection device is installed in such a position that the oil in the oil reservoir can visually be observed when the cowl is removed.
According to a preferred embodiment, the oil inspection device comprises an inspection unit with a fitting rubber member press-inserted into the engine, a glass window supported by the fitting rubber member and a detection plate, said detection plate has a detection surface disposed at a predetermined angle with respect to the oil surface and generally perpendicularly to an inspector's line of sight through the glass window.
According to a preferred embodiment, the oil reservoir is formed with an oil pan having an anti-fall stopper formed in a position below the detection plate, and a gap is provided between the anti-fall stopper and the detection plate.
According to a preferred embodiment, a propulsion unit is supported by a hull via a swivel bracket, and a carrying handle is provided for rotating said propulsion unit in forward and reverse position and with which said propulsion unit can be tilted up and down, wherein said carrying handle is provided with a cushioning member for preventing said carrying handle from interfering with a member on said hull.
According to a preferred embodiment, said cushioning member is provided on either upper or lower side of said carrying handle.
According to a preferred embodiment, hollow portions are formed between said carrying handle and said cushioning member.
According to a preferred embodiment, said carrying handle and said cushioning member overlap in at least a portion which may interfere with said member on said hull.
According to a preferred embodiment, said engine is disposed in an upper part of said propulsion unit for generating a propulsive force, and a propeller is arranged at a lower rear part of said propulsion unit and driven by said engine via a drive shaft and a propeller shaft.
In the following, the present invention is illustrated and explained in greater detail with respect to embodiments thereof in conjunction with the accompanying drawings, wherein:

Fig. 1: is a side view of an outboard motor;
Fig. 2: is a front view of the outboard motor;
Fig. 3: is a plan view of the outboard motor;
Fig. 4: is a vertical cross-sectional view of a casing part of the outboard motor;
Fig. 5: is a front view of the casing part of the outboard motor;
Fig. 6: is a cross-sectional view of an engine part of the outboard motor;
Fig. 7: is a plan view of the engine part of the outboard motor;
Fig. 8: is a plan view of the outboard motor with its fuel tank removed;
Fig. 9: is a side view of the engine of the outboard motor;
Fig. 10: is a rear view of the engine of the outboard motor;
Fig. 11: is a plan view of the fuel tank;
Fig. 12: is a plan view of a fly wheel;
Fig. 13: is a cross-sectional view taken along the line XIII-XIII in Fig. 12;
Fig. 14: is a front view of a cylinder head, illustrating breather chambers thereof;
Fig. 15: is an enlarged view of the part of the breather chambers of the cylinder head;
Fig. 16: is a cross-sectional view taken along the line XIV-XIV in Fig. 15;
Fig. 17: is a cross-sectional view taken along the line XV-XV in Fig. 15;
Fig. 18: is a cross-sectional view taken along the line XVI-XVI in Fig. 15;
Fig. 19: is a front view of a head cover, illustrating breather chambers thereof;
Fig. 20: is a side view of the head cover;
Fig. 21: is a plan view of the head cover;
Fig. 22: is a rear view of the head cover;
Fig. 23: is a cross-sectional view taken along the line XXI-XXI in Fig. 19;
Fig. 24: is an enlarged view of the part of the breather chambers of the head cover;
Fig. 25: is a cross-sectional view of an inspection unit;
Fig. 26: is a cross-sectional view taken along the line XXIV-XXIV in Fig. 25;
Fig. 27: is a plan view of a detection plate;
Fig. 28: is a cross-sectional view taken along the line XXVI-XXVI in Fig. 27;
Fig. 29: is a cross-sectional side view of a swivel bracket part in a forward position;
Fig. 30: is a side view of a propulsion unit in tilted-up state;
Fig. 31: is a side view of a carrying handle with a cushioning member fitted thereto;
Fig. 32: is a plan view of the carrying handle with the cushioning member fitted thereto;
Fig. 33: is a side view of the carrying handle;
Fig. 34: is a plan view of the carrying handle;
Fig. 35: is a bottom view of the carrying handle;
Fig. 36: is a side view of the cushioning member;
Fig. 37: is a plan view of the cushioning member;
Fig. 38: is a bottom view of the cushioning member;
Fig. 39: is a cross-sectional view taken along the line XVI-XVI in Fig. 32; and
Fig. 40: is a cross-sectional view taken along the line XVII-XVII in Fig. 32.

Regarding Figs. 1 to 3, a hull 1 of a boat has a transom board 1 a which forms the stern thereof, and a clamp bracket 3 of an outboard motor 2 holding the transom board 1a from above is fixed thereto with clamp members 4. A swivel bracket 33 is attached to the clamp bracket 3 via a tilt shaft 5 so that a propulsion unit 6 can be tilted up about the tilt shaft 5.
The propulsion unit 6 has a top cowl 6A, a bottom cowl 6B, an upper case 6C and a lower case 6D. An engine 9 and the like are housed in a space defined by the top and bottom cowls 6A and 6B. A choke knob 10 and a starter handle 11 are protruded from the front side of the top cowl 6A, and a fuel cap 12 is protruded from an upper part thereof. The top cowl 6A has a pair of right and left air inlets 34 in an upper part thereof, and the engine 9 is cooled by air introduced through the air inlets 34.
A carrying handle 13 is provided at an upper rear part of the upper case 6C. By rotating the propulsion unit 6 180° with the carrying handle 13, the running direction of the boat can be changed from forward to reverse, or from reverse to forward.
A bar-like steering handle 7 protruded forward is attached to the left side of the bottom cowl 6B. A shift lever 8 for engaging and disengaging a propulsive force is attached to the right side of the bottom cowl 6B.
As shown in Fig. 4, a drive shaft 15 driven by the engine 9 extends almost vertically through the upper and lower cases 6C and 6D, which are fitted together by clamp bolts 16.
The drive shaft 15 has a lower end on which a small diameter bevel gear 17 is secured. The bevel gear 17 is in meshing engagement with a large diameter bevel gear 18. The bevel gear 18 is rotatably journaled on the lower case 6D via a bearing 19 for reducing the rotational speed of the drive shaft 15.
The lower case 6D has a rear end part to which a propeller housing 20 is secured by a plurality of bolts 21. A propeller shaft 22 extends longitudinally through the propeller housing 20 and is rotatably supported at its mid-portion by the propeller housing 20 via a bearing 23.
The propeller shaft 22 has a rear end on which a boss 25a of a propeller 25 (Figs. 1 and 2) is fitted and integrally fixed by a nut 26. The boss 25a is integrated with a collar 27 with a rubber damper 28 interposed therebetween. The collar 27 is splined to the rear end of the propeller shaft 22, so that the propeller 25 is integrally rotated therewith.
Above the propeller 25, a cavitation plate 30 is fixed to the lower case 6D by a bolt 31 at a position close to the outer periphery of the propeller 25. An exhaust passage 32 (Fig. 4) is formed in the upper and lower cases 6C and 6D, and an outlet 32a of the exhaust passage 32 is formed in the lower front of the cavitation plate 30.
The propeller shaft 22 has a front end on which a dog clutch 40 is mounted for movement in the axial direction thereof. The dog clutch 40 is urged to be in constant contact with a shift pin 42 by a spring 41. The shift pin 42 is shift-operated by a shift rod 50. The shift rod 50 comprises an upper portion 50a and a lower portion 50b which can be connected by connecting means 60.
When the shift lever 8 is shifted, the shift rod 50 moves up and down about a shift shaft 55 via a link 56, and, when an operating portion 50b1 of the lower portion 50b presses the shift pin 42 (neutral position), a clutch projection 40a of the dog clutch 40 is released from engagement with a clutch recess 18a of the bevel gear 18, stopping the rotation of the propeller shaft 22.
When the operating portion 50b1 releases the shift pin 42 (engagement position), the dog clutch 40 is pressed by the spring 41 and the clutch projection 40a of the dog clutch 40 is brought into engagement with a clutch recess 18a of the bevel gear 18, rotating the propeller shaft 22 together therewith.
As shown in Fig. 29, a ball 58 urged by a spring 57 is received in a recess 6C4 formed in the upper case 6C. When the shift lever 8 is shifted to the neutral position or the engagement position, the ball 58 is brought into pressure contact with a recess 8a of the shift lever 8 to provide a click feel.
As shown in Fig. 4, the connecting means 60 for connecting the upper portion 50a and the lower portion 50b of the shift rod 50 comprises a pair of clamp plates 61 and a clamp bolt 63. The lower portion 50b of the shift rod 50 is put between the paired clamp plates 61 with the paired clamp plates 61 lightly clamped to the upper portion 50a. Then, the upper portion 50a and lower portion 50b are placed in position, and the paired clamp plates 61 are tightly clamped with the clamp bolt 63. Firstly, the paired clamp plates 61 are lightly clamped with the clamp bolt 63 and fitted to the upper portion 50a of the shift rod 50 by a washer 64.
The case has a pair of right and left work openings 70a and 70b (Figs. 1 and 2) on both sides thereof at positions corresponding to the connecting part of the upper portion 50a and the lower portion 50b of the shift rod 50.
The upper case 6C of the propulsion unit 6, through which the drive shaft 15 is disposed, has an upper part 6C1 having a circular cross-section and a lower part 6C2 having a wing-like cross-section, elongated in the longitudinal direction of the boat. The work openings 70a and 70b are formed toward the front of the part having the wing-like cross-section.
The work openings 70a and 70b can be closed by lid members 71 and 72, respectively. The lid members 71 and 72 are made of a rubber material, and the work openings 70a and 70b are sealed with the lid members 71 and 72, respectively.
The drive shaft 15, which is arranged in the rear of the shift rod 50, has an upper part connected to a crankshaft 100 of the engine 9 for rotation therewith and a lower part rotatably supported by the lower case 6D via a bearing 81. Said upper part is supported by the crankcase 105 of the engine via a bearing 80. A water pump 82 (Fig. 4) is driven with the drive shaft 15, and water is sucked into a water passage 84 through a water hole 83 formed in the lower case 6D. Water discharged from the water pump 82 is supplied to the engine 9 through a water passage 85 and a water introduction pipe 86.
In particular, water discharged from the water pump 82 is supplied through a water passage 85 and the water pipe 86 to a water passage 87 formed between the upper case 6C and a crankcase 105, then fed to every part of the engine 9 to cool the engine 9. The water passage 87 comprises a groove 6C3 formed in a joint surface of the upper part 6C1 of the upper case 6C and a groove 90a1 formed in a joint surface of a lower part 90a of the crankcase 105.
Excess pilot water is discharged to the outside from the water passage 87 through a water discharge port 88 formed in the upper part 6C1 of the upper case 6C.
The upper case 6C of the propulsion unit 6 is rotatably supported by a bearing part 33a of the swivel bracket 33, so that the propulsion unit 6 can be rotated 180° between forward and reverse positions with respect to the swivel bracket 33 with the carrying handle 13.
The swivel bracket 33 is provided with a separately formed gutter member 89 for receiving pilot water coming down from the water discharge port 88 and guiding the pilot water to the outside of the hull 1. The gutter member 89 is located below and on the side of the hull 1 from a locus which the water discharge port 88 draws when the propulsion unit 6 is rotated, and fitted to the swivel bracket 33.
As described before, the propulsion unit 6 can be rotated 180°between the forward and reverse positions with respect to the swivel bracket 33. When the boat is running forward, the water discharge port 88 is located on the rear side and pilot water is discharged from the rear side of the propulsion unit 6. When the propulsion unit 6 is rotated 180° to allow the boat to run backward, the water discharge port 88 is located on the front side, namely the hull side. However, pilot water falls from the water discharge port 88 onto the gutter member 89 and is guided thereby to the outside of the hull 1. Thus, the pilot water is prevented from entering the hull 1.
The propulsion unit 6 is tilted up and down about the tilt shaft 5 with a carrying handle 13 as shown in Fig. 30.
The engine 9 of this embodiment, which is constituted as shown in Fig. 6 through Fig. 28, is a single-cylinder, four-cycle engine and has a crank case 105, a cylinder body 102, a cylinder head 103 and a head cover 104. The crankshaft 100 extends vertically and is rotatably supported by the cylinder body 102 and the crank case 105. The crank case 105 has an oil reservoir 105b and forms an oil pan.
A piston 106 is movably received in the cylinder body 102. The piston 106 is connected to the crankshaft 100 via a piston pin 107 and a connecting rod 108, so that the movement of the piston 106 rotates the crankshaft 100. An intake passage 110 and an exhaust passage 111 formed in the cylinder head 103 open into a combustion chamber 112, and are opened and closed by an intake valve 113 and an exhaust valve 114, respectively.
The combustion chamber 112 is defined by the cylinder body 102, the piston 106 and the cylinder head 103. To the intake passage 110, air is introduced from an intake silencer 161 and fuel is supplied from a fuel supply device 115, to which fuel is supplied from a fuel tank 116 through a fuel hose 117. The exhaust passage 111 is communicated to an exhaust passage 118 formed in the crank case 105, and exhaust gas is discharged through the exhaust passage 118 and the exhaust passage 32 formed in the upper case 6C and the lower case 6D.
A driving gear 120 is provided on the crankshaft 100. As shown in Fig. 7, the driving gear 120 is meshing engagement with a driven gear 121 which rotates the cam shaft 122. A cam 123a and 123b corresponding to the intake valve 113 and the exhaust valve 114, respectively, are provided on the cam shaft 122. By the rotation of the cams 123a and 123b, push rods 124a and 124b are operated and open and close the intake valve 113 and the exhaust valve 114 via rocker arms 125a and 125b, respectively, at a predetermined timing.
The rocker arms 125a and 125b are attached to the cylinder head 103. Also attached to the cylinder head 103 is a spark plug 126 with its end facing into the combustion chamber 112. An opening 127 is formed in the bottom cowl 6B in a position opposed to the spark plug 126, and closed by a cap 128. Maintenance or exchange of the spark plug 126 can be performed by removing the cap 128 and inserting a tool from the opening 127 without removing the bottom cowl 6B. As shown in Fig. 8, the opening 127, which is formed in that inclined surface of the bottom cowl 6B which faces downward and closed by the cap 128, hardly permits entrance of water, and is hardly visible from the outside and thus good in appearance.
The crankshaft 100 has an upper part received in a fitting hole 130a of a fly wheel 130, engaged with a key 131, and clamped by a nut 132, so that the fly wheel 130 can be rotated together with the crankshaft 100. The fly wheel 130 has an upper surface on which protrusions 130b are formed as shown in Fig. 12 and Fig. 13, so that an air flow is created by rotation of the fly wheel 130.
The fly wheel 130 is covered with a fly wheel cover 133, which is secured to the cylinder body 102 by a clamp bolt 135 together with an extension 134a of a starter cover 134 of a starter 140.
The starter 140 comprises a primary rotor 141, a return spring 142, an engaging slider 143 and a driven rotor 144. The primary rotor 141 is rotatably joumaled on a rotational center shaft 146, and a wire 147 wound around the primary rotor 141 is connected to a starter handle 11. When the starter handle 11 is pulled, the primary rotor 141 is rotated about the rotational center shaft 146, and then restored to the original position by the return spring 142.
The driven rotor 144 is clamped to an upper part of the crankshaft 100 by the nut 132. Along with the rotation of the primary rotor 141, the engaging slider 143 is moved and brought into engagement with an engaging portion 144a of the driven rotor 144. Thereby, the driven rotor 144 is rotated together with the primary rotor 141, and forcibly rotates the crankshaft 100 to start the engine 9. When engine 9 is started, the engaging slider 143 is restored to its original position and disengaged from the driven rotor 144.
The rotational center shaft 146 is secured to the starter cover 134 by a clamp bolt 149. A handle attaching part 134b is formed on the starter cover 134. A rubber seal 148 is provided at the handle attaching part 134b for sealing a gap between the handle attaching part 134b and the top cowl 6A.
In this embodiment, the extension 134a of the starter cover 134 forms a partition and has a periphery 134c. A partition seal 150 is provided on the periphery 134c and a rising portion 134d of the starter cover 134 is provided for sealing a gap between them and the top cowl 6A.
The space defined by the top cowl 6A and the bottom cowl 6B is partitioned by the starter cover 134 and the partition seal 150 to form a fuel tank room A on the upper side and an engine room B on the lower side. The fuel tank room A houses the fuel tank 116 and the engine room B houses the engine 9. As described above, the starter cover 134 is extended, and the thus formed extension 134a forms the partition. By integrating the starter cover 134 and the partition, the fuel tank room A and the engine room B can be partitioned with a simple and compact structure and without using a special member.
The fuel tank 116 has a front end portion 116a secured to the rotational center shaft 146 of the starter 140 by a clamp bolt 149 with a rubber damper 151 interposed therebetween (Fig. 6). The fuel tank 116 also has rear end portions 116b and 116c secured by clamp bolts 154 and 155 with rubber dampers 152 and 153 interposed therebetween, respectively (Figs. 10 and 11). A fuel cap 12 is provided on top of the fuel tank 116. As described above, one end portion 116a of the fuel tank 116 is secured to the rotational center shaft 146 of the starter 140.
The rotational center shaft 146 of the starter 140 is supported by the starter cover 134, which is firmly secured together with the fly wheel cover 133, and the fuel tank 116 is secured to the rotational center shaft 146, which is firmly supported essentially. Thus, the fuel tank 116 can be firmly secured even with a compact structure and without using a special fitting member.
As shown in Fig. 6, Fig. 9 and Fig. 11, the fuel tank 116 has a tank capacity section 116d formed by extending a front part thereof and covering about a half of the starter 140, so that the fuel tank 116 can have a sufficient capacity.
In this embodiment, the tank capacity section 116d as a part of the fuel tank 116 covers the starter 140, and the extension 134a of the starter cover 134 has a communication hole 170 for communicating the fuel tank room A and the engine room B at a position under the tank capacity section 116d of the fuel tank 116. There is a gap 180 between the fuel tank 116 and the starter cover 134 forming the partition, and outside air can be introduced into the gap 180.
Air introduced into the fuel tank room A through the paired right and left air inlets 34 passes through a gap 181 between the fuel tank 116 and the top cowl 6A and the gap 180, and then introduced into the engine room B through the communication hole 170.
The outside air is introduced into the engine room B through the communication hole 170 by the rotation of the fly wheel 130 and flows through an opening 133a in the fly wheel cover 133 to cool the cylinder body 102 and the cylinder head 103.
As described above, the gap 180 is provided between the fuel tank 116 and the extension 134a of the starter cover 134 which forms the partition and the communicating hole 170 is formed in the partition to form a maze-like passage through which outside air is introduced to the engine room B. Thereby, it is possible to improve engine cooling performance by preventing outside air containing water from adversely affecting the engine 9 and to prevent the fuel from becoming high in temperature, even with a compact structure.
Also, by introducing outside air into the gap 180, water contained in the outside air can be removed. Additionally, the air inhibits the transmission of heat from the engine 9 and cools a surface of the fuel tank 116 on the side of the engine 9 effectively.
The fuel tank 116 has an extended portion overhanging the starter 140, so that the fuel tank 116 can have sufficient capacity. The communication hole 170 for introducing air into the engine room B is formed in the starter cover 134 covering the starter 140, and the fuel tank 116 is arranged such that the communication hole 170 formed in the starter cover 134 is covered with a part of the fuel tank 116, so that the fuel tank 116 can be effectively cooled by the outside air flowing toward the communication hole 170. Additionally, even if water enters the cowl from the outside, since the communication hole 170 and said part of the fuel tank 116 which covers the communication hole form a maze-like structure, the water can hardly flow into the engine side through the communication hole 170. Accordingly, even if water enters the cowl from the outside, since the inside of the fuel tank room A has a labyrinth structure in which outside air is introduced into the engine room B through the communication hole 170 formed in that part of the partition which is covered with a part of the fuel tank 116, the water can hardly flow into the engine side through the communication hole 170.
As shown in Fig.7, the cylinder head 103 and the head cover 104 are joined and clamped by clamp bolts 201 with a gasket 200 interposed therebetween. As shown in Fig. 14 through Fig. 18, three breather recesses 103a to 103c are formed in the cylinder head 103. A notch 103d1 is formed in a wall 103d between the breather recesses 103a and 103b, by which the breather recesses 103a and 103b are communicated to each other. A notch 103f1 is formed in a wall 103f between the breather recess 103c and an external recess 103e, by which the breather recess 103c and the external recess 103e are communicated to each other.
A nipple 202 is attached to the cylinder head 103 and communicated to the breather recess 103a. The nipple 202 is communicated to the intake silencer 161 via a hose 203.
As shown in Fig. 19 through Fig. 24, three breather recesses 104a to 104c are formed in the head cover 104. A notch 104d1 is formed in a wall 104d between the breather recesses 104a and 104b, by which the breather recesses 104a and 104b are communicated to each other. A notch 104e1 is formed in a wall 104e between the breather recesses 104a and 104c, by which the breather recesses 104a and 104c are communicated to each other. A notch 104g1 is formed in a wall between the breather recess 104b and an external recess 104f, by which the breather recess 104b and the external recess 104f are communicated to each other.
When the cylinder head 103 and the head cover 104 are joined with the gasket 200 interposed therebetween, breather chambers C1 to C3 are formed by the three breather recesses 103a to 103c and the three breather recesses 104a to 104c, respectively, and a valve chamber C4 is formed by the external recesses 103e and the 104f.
Thus, gas containing oil flows into the breather chamber C3 through a notch 103f1 located at the lowermost part thereof from the valve chamber C4, and into the breather chamber C1 through the notch 104e1, then into the breather chamber C2 through the notch 104d1 and into the breather chamber C1 through the notch 103d1. While the oil containing gas flows as shown by the arrow in Fig. 14, the oil is separated therefrom and returned to the valve chamber C4 through the notch 104g1. The reminder gas is returned to the intake silencer 161 from the breather chamber C1 through the nipple 202 and the hose 203.
As described above, the breather chambers C1 to C3 are formed by the cylinder head 103 and the head cover 104, so that the breather chambers C1 to C3 can have sufficient capacities. Also, the notches 103d1, 104d1 and 104e1 for communicating the breather chambers C1 to C3 are easy to form by molding since they are formed in the joint surfaces of the cylinder head 103 and the head cover 104.
In this embodiment, as shown in Fig. 7 and Fig. 10, there is provided an oil inspection device 300 which enables visual observation of oil reserved in an oil reservoir D in the engine 9. The oil inspection device 300 is installed in such a position that the oil in the oil reservoir D can be visually observed when the top cowl 6A is removed.
As shown in Fig. 25 through Fig. 28, the oil inspection device 300 has an inspection unit 304 comprising a fitting rubber member 301 press-inserted into the engine 9, a glass window 302 supported by the fitting rubber member 301, and a detection plate 303. The glass window 302 is supported at the periphery by the fitting rubber member 301 and the detection plate 303 is fitted to the fitting rubber member 301 by an annular metal plate 305.
The detection plate 303 is a metal plate formed by punching and has an annular fitting portion 303a, a circular detecting portion 303b and holding portions 303c. The annular fitting portion 303a is engaged with the annular metal plate 305 and held by the fitting rubber member 301. The detection portion 303b is held at a predetermined angle with respect to the glass window 302 by the holding portion 303c.
The oil reservoir D is formed with the cylinder body 102 and the crank case 105. The crank case 105 forms an oil pan. As shown in Fig.10, the inspection unit 304 is fitted to the cylinder body 102 by inserting the fitting rubber member 301 into a fitting recess 102a formed in a lower part of the cylinder body 102 from below before the crank case 105 is fitted to the cylinder body 102. Then, the crank case 105 is fitted to the cylinder body 102.
The crank case 105 has an anti-fall stopper 105a formed in a position below the detection portion 303b of the detection plate 303. A gap S is provided between the anti-fall stopper 105a and the detection portion 303b.
As shown in Fig. 10, when the inspection unit 304 is fitted, the glass window 302 is horizontal. The detection plate 303 has a detection surface 303b1, which is at a predetermined angle with respect to the oil surface L and generally perpendicular to an inspector's line of sight through the glass window 302. The lower end and the upper end of the inspection surface 303b1 indicate a lower limit level L1 and an upper limit level L2, respectively. When the oil surface L lowers to the lower limit level L1, oil needs to be replenished to the upper limit level L2.
As the detection surface 303b1 of the detection plate 303 is at a predetermined angle with respect to the oil surface L, the oil level can be visually observed with ease. Also, since the detection surface 303b1 of the detection plate 303 is generally perpendicular to an inspector's line of sight through the glass window 302, the degree of contamination of the oil can be easily checked by the color thereof.
The inspection unit 304 can be easily fitted to the engine 9 by press-inserting the fitting rubber member 301 into the fitting recess 102a of the cylinder body 102. Also, the anti-fall stopper 105a of the crank case 105 prevents the inspection unit 304 from falling off.
Additionally, the gap S is provided between the anti-fall stopper 105a and the detection portion 303b of the detection plate 303, so that, when the oil surface L is lowered to slightly below the top of the anti-fall stopper 105a, the oil may be dominated on top of the anti-fall stopper 105a by the surface tension thereof but is prevented from rising from the anti-fall stopper 105a to the detection portion 303b by capillary action. Thus, the oil surface L is kept under the lower limit level L1 and the oil level can be observed accurately.
The carrying handle 13 attached to the propulsion unit 6 is constituted as shown in Fig. 31 through Fig. 40.
In this embodiment, the carrying handle 13 is provided with a cushioning member 13A for preventing interference of the carrying handle 13 with a member on the hull 1. As shown in Fig. 33 through Fig. 35, the carrying handle 13 comprises an aluminum die-cast frame having a generally rectangular shape as seen in a plan view and has a fitting portion 13a at one end, a grip 13b at the other, and connecting portions 13c, 13d, each of which connects ends of the fitting portion 13a and the grip 13b on the same side.
The fitting portion 13a has a pair of bolt holes 13a1. The grip 13b and the connecting portions 13c, 13d have recesses 13b1, 13c1 and 13d1, respectively, on the side to which the cushioning member 13A is fitted. The connecting portions 13c, 13d have screw holes 13c2 and 13d2, respectively, at both ends.
As shown in Fig. 36 through Fig. 38, the cushioning member 13A, which is made of a resin and is of a generally U-shape as seen in a plan view, has a grip 13Aa and connecting portions 13Ab, 13Ac on both sides of the grip 13Aa.
The grip 13Aa and the connecting portions 13Ab, 13Ac have recesses 13Aa1, 13Ab1 and 13Ac1, respectively, on the side to which the carrying handle 13 is attached. The connecting potions 13Ab, 13Ac have screw fastening holes 13Ab2 and 13Ac2, respectively, as both ends.
The cushioning member 13A is fitted to the lower side of the carrying handle 13 and, as shown in Fig. 31 and Fig. 32, screws 13C are inserted into the screw holes 13c2 and 13d2 and screwed into the screw fastening holes 13Ab2 and 13Ac2. As shown in Fig. 30, the carrying handle 13 is secured to an upper part of the upper case 6C by bolts 13D inserted through the bolt holes 13a1 in the fitting portions 13a.
Thereby, when the propulsion unit 6 in the reverse position is tilted up or down about the tilt shaft 5 with the carrying handle as shown in Fig. 30, the carrying handle 13 is prevented from interfering with the clamp means 4 on the hull by the cushioning member 13A. Thus, the carrying handle 13 can be prevented from being damaged and kept in good appearance. Also, the cushioning member 13A improves the durability of the carrying handle 13.
In this embodiment, the cushioning member 13A is attached to a lower side of the carrying handle 13. The cushioning member 13A only need to be provided on either upper or lower side of the carrying handle which may interfere with the clamp member 4 on the hull. The cushioning member 13A and the carrying handle 13 are integrated together and provide a good grip. Additionally, there is no need for a specifically designed cushioning member.
Between the carrying handle 13 and the cushioning member 13A, a hollow 13E is formed by the recesses 13b1 and 13Aa1 as shown in Fig. 40, and hollows 13F are formed by the recesses 13c1, 13d1, and 13Aab1, 13Ac1, respectively, as shown in Fig. 39. The hollows between the carrying handle 13 and the cushioning member 13A make the handle assembly light in weight and improve the rigidity thereof.
As shown in Fig. 39, the carrying handle 13 and the cushioning member 13A are fitted to each other such that portions 13c11, 13d11 of the carrying handle 13, which may interfere with the clamp member 4 on the hull, are overlapped with portions 13Ab3, 13Ac3 of the cushioning member 13A, respectively. The overlapped portions of the carrying handle 13 and the cushioning member 13A improve the strength of the cushion and also enhance the strength of the handle assembly.
Regarding a first aspect, the embodiment described above teaches an outboard motor comprising: a propulsion unit 6 supported by a hull 1 via a swivel bracket 33, an engine (9) disposed in a cowl 6A, 6B of the propulsion unit 6 for generating a propulsive force; and a fuel tank 116 for supplying fuel to the engine 9. The engine 9 has a starter 140 having a rotational center shaft 146; and the fuel tank 116 has an end secured to the rotational center shaft 146 of the starter 140. Accordingly, an end of the fuel tank is secured to the rotational center shaft of the starter, so that the fuel tank can be firmly secured with a compact structure and without a special fitting member. In addition, the fuel tank can have sufficient capacity. Thus, it is provided an outboard motor which is compact in structure and in which a fuel tank can be firmly secured. Furthermore, it is provided an outboard motor in which sufficient fuel tank capacity can be obtained.
The fuel tank 116 has an extended portion 116d overhanging the starter 140, and the starter 140 is covered with a starter cover 134 having a communication hole 170 for introducing air, and the fuel tank 116 is arranged such that the communication hole 170 is covered with the extended portion of the fuel tank 116. Accordingly, the fuel tank has an extended portion overhanging the starter, so that the fuel tank can have sufficient capacity. Also, the fuel tank is arranged such that the communication hole formed in the starter cover is covered with the extended portion of the fuel tank, so that the fuel tank can be effectively cooled by the outside air flowing toward the communication hole. Additionally, even if water enters the cowl, since the communication hole and that part of the fuel tank which covers the communication hole form a maze-like structure, the water can hardly flow into the engine side through the communication hole.
The fuel tank 116 has a tank capacity section formed by extending a part thereof and located above the starter 140. Accordingly, the fuel tank has an extended portion located above the starter and thus can have sufficient capacity.
The starter cover 134 has an extension 134a partitioning a fuel tank room A and an engine room B. Accordingly, the fuel tank room and the engine room can be partitioned with a simple and compact structure by using the starter cover and without a special member.
A gap 180 is provided between the fuel tank 116 housed in the fuel tank room A and the starter cover 134, and air can be introduced into the gap 180. Accordingly, by introducing outside air into the gap provided between the fuel tank housed in the fuel tank room and the starter cover, the fuel can be prevented from becoming high in temperature by the outside air, and engine cooling performance can be improved even with a compact structure.
Regarding a second aspect, the embodiment described above teaches an outboard motor comprising: a propulsion unit 6 supported by a hull via a swivel bracket; an engine 9 disposed in a cowl 6A, 6B of the propulsion unit 6 for generating a propulsive force, and a fuel tank 116 for supplying fuel to the engine 9. An inside space of the cowl 6A, 6B is partitioned by a partition to form a fuel tank room A on the upper side and an engine room B on the lower side, and the partition has a communication hole 170 for communicating the fuel tank room A and the engine room B, so that outside air introduced into the fuel tank room (A) can be introduced into the engine room B therethrough. Accordingly, there is provided a labyrinth structure that permits outside air to be introduced into the fuel tank room and then into the engine room through the communication hole formed in the partition. Therefore, it is possible to prevent the engine from being adversely affected by outside air containing water to improve engine cooling performance. Also, it is possible to prevent the fuel from becoming high in temperature. Thus, it is provided an outboard motor which can prevent the engine from being adversely affected by outside air containing water to improve engine cooling performance and which can prevent fuel from becoming high in temperature in spite of its compact structure.
Said engine 9 is provided with a starter 140, and the partition is formed by extending a starter cover 134 covering the starter 140. Accordingly, the partition is formed by extending the starter cover covering the starter, so that the outboard motor can have a compact structure in which the starter cover and the partition are integrated with each other. Furthermore, a gap 180 is provided into which outside air can be introduced between the fuel tank 116 housed in the fuel tank room A and the partition. Accordingly, by introducing outside air into the gap provided between the fuel tank and the partition, water contained in the outside air can be removed. In addition, the outside air inhibits the transmission of heat from the engine and cools a surface of the fuel tank on the side of the engine effectively.
The fuel tank 116 has an end part secured to a rotational center shaft 146 of the starter 140. Accordingly, an end of the fuel tank is secured to the rotational center shaft of the starter. Since the rotational center shaft of the starter serves as a tank securing member and there is no need for a special member therefor, the outboard motor can be compact in structure. In addition, the fuel tank is secured to the rotational center shaft of the starter, which is firmly supported essentially, so that the fuel tank can be firmly secured with a simple structure. Said starter 140 is covered with a part of the fuel tank 116 from above, and the communication hole 170 is formed in that position of the partition which is covered with the part of fuel tank 116. Accordingly, the fuel tank can have sufficient capacity due to that part of the fuel tank which covers the starter. Also, the present invention has a labyrinth structure that outside air is introduced into the engine room through the communication hole formed in that position of the partition which is covered with a part of the fuel tank, so that water contained in the outside air can be removed. In addition, the outside air inhibits the transmission of heat from the engine and cools a surface of the fuel tank on the side of the engine effectively.
Regarding a third aspect, the embodiment described above teaches an outboard motor comprising: a propulsion unit 6 supported by a hull 1 via a swivel bracket 33; an engine 9 disposed in a cowl 6A, 6B of the propulsion unit 6 for generating a propulsive driving force; and an oil inspection device 300 which enables visual observation of oil reserved in an oil reservoir D in the engine 9. The oil inspection device 300 is installed in such a position that the oil in the oil reservoir D can visually be observed when the cowl 6A, 6B is removed; that the oil inspection device 300 has an inspection unit 304 comprising a fitting rubber member 301 press-inserted into the engine 9, a glass window 302 supported by the fitting rubber member 301 and a detection plate 303; and that the detection plate 303 has a detection surface 303b1 disposed at a predetermined angle with respect to the oil surface L and generally perpendicularly to an inspector's line of sight through the glass window 302. Accordingly, the detection surface of the detection plate is disposed at a predetermined angle with respect to the oil surface, so that the oil level can be visually observed with ease. Also, the detection surface of the detection plate is disposed generally perpendicularly to an inspector's line of sight through the glass window, so that the degree of contamination of the oil can visually be checked by the color thereof with ease. Furthermore, it is provided an outboard motor in which the amount and degree of contamination of engine oil can be easily observed when the cowl is removed.
The oil reservoir D is formed with an oil pan having an anti-fall stopper 105a formed in a position below the detection plate 303, and a gap S is provided between the anti-fall stopper 105a and the detection plate 303. Accordingly, the anti-fall stopper of the oil pan prevents the inspection unit from falling off. Also, since there is a gap between the anti-fall stopper and the detection plate, oil does not rise from the anti-fall stopper to the detection plate, making it possible to observe the oil level accurately.
Regarding a fourth aspect, the embodiment described above teaches an outboard motor comprising a propulsion unit 6 supported by a hull 1 via a swivel bracket 33, an engine 9 disposed in an upper part of said propulsion unit 6, and a propeller 25 arranged at a lower rear part of said propulsion unit 6 and driven by said engine 9 via a drive shaft 15 and a propeller shaft 22. Said propulsion unit 6 has a carrying handle 13 with which said propulsion unit 6 can be rotated with respect to said swivel bracket 33 between forward and reverse positions and with which said propulsion unit 6 can be tilted up and down. Said carrying handle 13 is provided with a cushioning member 13A for preventing said carrying handle 13 from interfering with a member 4 on said hull 1. Accordingly, the cushioning member provided on the carrying handle prevents the carrying handle from being damaged by interference with a member on the hull and keeps the appearance of the carrying handle good. Also, the cushioning member improves the durability of the carrying handle. Furthermore, it is provided an outboard motor in which a carrying handle can be protected from being damaged and kept in good appearance, and has an increased durability.
Said cushioning member 13A is provided on either upper or lower side of said carrying handle 13. Accordingly, the cushioning member is provided on either upper or lower side of the carrying handle and integrated with the carrying handle. The cushioning member serves as a part of the carrying handle and thus can provide a good grip. Additionally, there is no need for a specifically designed cushioning member.
Hollows 13E, 13F are formed between said carrying handle 13 and said cushioning member 13A. Accordingly, the hollows between the carrying handle and the cushioning member makes the handle assembly light in weight and improve the rigidity thereof.
Said carrying handle 13 and said cushioning member 13A overlap in at least a portion which may interfere with said member 4 on said hull 1. Accordingly, the overlapped portions of the carrying handle and the cushioning member improve the strength of the cushion and also enhance the strength of the handle assembly.
The embodiment described above teaches an outboard motor comprising a propulsion unit 6 with an engine 9 having a starter 140 and a fuel tank 116 for supplying fuel to the engine 9. Said starter 140 comprises a rotational center shaft 146. The fuel tank 116 has an end 116a secured to said rotational center shaft 146 of the starter 140. Furthermore, said fuel tank 116 has an extended portion 116d overhanging the starter 140. Said starter 140 is covered with a starter cover 134 having a communication hole 170 for introducing air. Said fuel tank 116 is arranged such that the communication hole 170 is covered with the extended portion 116d of the fuel tank 116.
Said starter cover 134 has an extension 134a forming a partition between a fuel tank room A receiving said fuel tank 116 and an engine room B receiving said engine 9. Said communication hole 170 is provided for communicating the fuel tank room A and the engine room B, so that outside air introduced into the fuel tank room A can be introduced into the engine room B therethrough. A gap 180 is provided between the fuel tank 116 housed in the fuel tank room A and the starter cover 134, and air can be introduced into the gap 180. Said fuel tank 116 has a tank capacity section formed by extending a part thereof and located above the starter 140.
Said embodiment of the outboard motor is provided with an oil inspection device 300 for visual observation of oil reserved in an oil reservoir D in the engine 9. Said oil inspection device 300 is installed in such a position that the oil in the oil reservoir D can visually be observed when the cowl 6A, 6B is removed. Said oil inspection device 300 comprises an inspection unit 304 with a fitting rubber member 301 press-inserted into the engine 9, a glass window 302 supported by the fitting rubber member 301 and a detection plate 303, said detection plate 303 has a detection surface 303b1 disposed at a predetermined angle with respect to the oil surface L and generally perpendicularly to an inspector's line of sight through the glass window 302. The oil reservoir D is formed with an oil pan having an anti-fall stopper 105a formed in a position below the detection plate 303, and a gap S is provided between the anti-fall stopper 105a and the detection plate 303.
Said embodiment of the outboard motor is provided with a propulsion unit 6 supported by a hull 1 via a swivel bracket 33. A carrying handle 13 is provided for rotating said propulsion unit 6 in forward and reverse position and with which said propulsion unit 6 can be tilted up and down. Said carrying handle 13 is provided with a cushioning member 13A for preventing said carrying handle 13 from interfering with a member 4 on said hull 1. Said cushioning member 13A is provided on either upper or lower side of said carrying handle 13. Hollow portions 13E, 13F are formed between said carrying handle 13 and said cushioning member 13A. Said carrying handle 13 and said cushioning member 13A overlap in at least a portion which may interfere with said member 4 on said hull 1.
Said embodiment of the outboard motor comprises the engine 9 disposed in an upper part of said propulsion unit 6 for generating a propulsive force, and a propeller 25 arranged at a lower rear part of said propulsion unit 6 and driven by said engine 9 via a drive shaft 15 and a propeller shaft 22.

Claims

An outboard motor comprising a propulsion unit (6) with an engine (9) having a starter (140) and a fuel tank (116) for supplying fuel to the engine (9), said starter (140) comprises a rotational center shaft (146), characterized in that the fuel tank (116) has an end (116a) secured to said rotational center shaft (146) of the starter (140).
An outboard motor according to claim 1, wherein the fuel tank (116) has an extended portion (116d) overhanging the starter (140), and the starter (140) is covered with a starter cover (134) having a communication hole (170) for introducing air, and the fuel tank (116) is arranged such that the communication hole (170) is covered with the extended portion (116d) of the fuel tank (116).
An outboard motor according to claim 2, wherein the starter cover (134) has an extension (134a) forming a partition between a fuel tank room (A) receiving said fuel tank (116) and an engine room (B) receiving said engine (9), and said communication hole (170) is provided for communicating the fuel tank room (A) and the engine room (B), so that outside air introduced into the fuel tank room (A) can be introduced into the engine room (B) therethrough.
An outboard motor according to claim 3, wherein a gap (180) is provided between the fuel tank (116) housed in the fuel tank room (A) and the starter cover (134), and air can be introduced into the gap (180).
An outboard motor according to at least one of the claims 1 to 4, wherein the fuel tank (116) has a tank capacity section formed by extending a part thereof and located above the starter (140).
An outboard motor according to at least one of the claims 1 to 5, wherein an oil inspection device (300) is provided for visual observation of oil reserved in an oil reservoir (D) in the engine (9).
An outboard motor according to claim 6, wherein the oil inspection device (300) is installed in such a position that the oil in the oil reservoir (D) can visually be observed when the cowl (6A, 6B) is removed.
An outboard motor according to claim 6 or 7, wherein the oil inspection device (300) comprises an inspection unit (304) with a fitting rubber member (301) press-inserted into the engine (9), a glass window (302) supported by the fitting rubber member (301) and a detection plate (303), said detection plate (303) has a detection surface (303b1) disposed at a predetermined angle with respect to the oil surface (L) and generally perpendicularly to an inspector's line of sight through the glass window (302).
An outboard motor according to at least one of the claims 6 to 8, wherein the oil reservoir (D) is formed with an oil pan having an anti-fall stopper (105a) formed in a position below the detection plate (303), and a gap (S) is provided between the anti-fall stopper (105a) and the detection plate (303).
An outboard motor according to at least one of the claims 1 to 9, wherein a propulsion unit (6) is supported by a hull (1) via a swivel bracket (33), and a carrying handle (13) is provided for rotating said propulsion unit (6) in forward and reverse position and with which said propulsion unit (6) can be tilted up and down, wherein said carrying handle (13) is provided with a cushioning member (13A) for preventing said carrying handle (13) from interfering with a member (4) on said hull (1).
An outboard motor according to claim 10, wherein said cushioning member (13A) is provided on either upper or lower side of said carrying handle (13).
An outboard motor according to claim 10 or 11, wherein hollow portions (13E, 13F) are formed between said carrying handle (13) and said cushioning member (13A).
An outboard motor according to any one of claims 10 to 12, wherein said carrying handle (13) and said cushioning member (13A) overlap in at least a portion which may interfere with said member (4) on said hull (1).
An outboard motor according to any one of claims 1 to 13, wherein said engine (9) is disposed in an upper part of said propulsion unit (6) for generating a propulsive force, and a propeller (25) is arranged at a lower rear part of said propulsion unit (6) and driven by said engine (9) via a drive shaft (15) and a propeller shaft (22).