JP3485098B2 - Outboard motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outboard motor. 2. Description of the Related Art As means for opening and closing a throttle valve of a carburetor mounted on an engine of an outboard motor, for example, a throttle valve (not shown) is disclosed in Japanese Utility Model Laid-Open Publication No. 61-25299. In many cases, a throttle lever provided at the shaft end of the vehicle and a throttle grip provided at the end of the steering handle are connected by a wire and a rod. [0003] By the way, the increase in the engine speed corresponding to the opening of the throttle grip is larger in a four-cycle engine than in a two-cycle engine. However, in the above-described prior art, since the throttle lever and the throttle grip are connected by a wire and a rod, their respective opening degrees become substantially linear. As a result, when the ratio between the opening of the throttle lever and the opening of the throttle grip, that is, the lever ratio is adjusted to the high-speed side, the opening of the throttle grip decreases,
It becomes difficult to finely adjust the engine speed during low-speed operation of the engine. Further, when the lever ratio is set to the low speed side, the opening degree of the throttle grip becomes large, and the opening / closing operation of the throttle grip becomes difficult, so that the drivability is impaired. Further, since a rod and a link device are interposed between the wire from the throttle grip and the throttle lever, play and play are liable to occur, and it is necessary to make adjustments at all times, resulting in poor maintainability. The present invention has been made in view of the above circumstances, and has as its object to provide an outboard motor having a compact structure and improved engine drivability. Another object of the present invention is to provide an outboard motor with improved maintainability. [0008] An outboard motor according to the present invention comprises:
In order to solve the above-mentioned problem, as described in claim 1, a crankshaft is provided vertically, and a reciprocating motion of a piston in a cylinder bore extending in a direction perpendicular to the crankshaft corresponds to a rotational motion of the crankshaft. A four-stroke engine that is converted and transmitted to a propeller via a drive shaft, an engine intake system that includes an intake pipe, a carburetor, and an intake pipe, and that is connected to a cylinder head of the engine; An outboard motor having an engine cover having a mouth and an engine starting device, and having a carburetor provided with a throttle control device having a throttle opening / closing means, wherein the engine starting device is disposed above the engine; Outside air sucked from the air inlet is sucked through the intake pipe. While disposing the carburetor to the cylinder head above the engine, in which is disposed so as not to protrude outward from the engine intake system at the time of operating the throttle closing means. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a right side view showing an example of an outboard motor according to the present invention. As shown in FIG. 1, this outboard motor 1 has a box-shaped engine cover 2 at the top, and a vertical engine 3 is housed inside. A steering handle 4 extends forward from a front portion (the right side in FIG. 1) of the engine cover 2, and a throttle grip 5 serving as throttle operating means for adjusting the engine output is provided at the tip. A drive shaft housing 6 is provided below the engine cover 2, and a gear case 7 is provided below the drive shaft housing 6.
A propeller shaft 8 is rotatably supported inside the gear case 7, and a propeller 9 is provided at a rear end thereof. FIG. 2 shows the engine 3 of the outboard motor 1 shown in FIG.
It is a longitudinal cross-sectional view of a part. As shown in FIG.
Inside, the crankshaft 10 is provided vertically (vertically) so as to face a substantially vertical direction. As shown in FIGS. 1 and 2, a shaft pipe 11 is formed in the drive shaft housing 6, and a crankshaft 10 is formed in the shaft pipe 11.
The drive shaft 12 connected to the lower end extends downward, and the lower end of the drive shaft 12 is linked to the propeller shaft 8 via the clutch mechanism 13. The output of the engine 3 is transmitted to the propeller shaft 8 via the drive shaft 12 and the clutch mechanism 13. The clutch mechanism 13 is remotely operated by a clutch control lever 51 connected to the engine 3 via a clutch control rod 50.
A clutch device 52 that changes the rotation direction of the propeller shaft 8 and the propeller 9 by switching the clutch mechanism 13 is provided. On the other hand, the upper portion of the drive shaft housing 6 is rotatably supported by a rotation support portion 16 of a clamp bracket 15, and the clamp bracket 15 is fixed to a transom 18 of a boat 17. That is, the outboard motor 1 is provided so as to be rotatable about 360 ° with respect to the boat 17, and the steering of the boat 17 is performed by changing the direction of the entire outboard motor 1 by swinging the steering handle 4 in the horizontal direction. It is configured to be able to. The engine cover 2 is, for example, vertically splittable, and includes a lower cover 2a fixed to a lower portion of the engine 3, and an upper cover detachably mounted on the lower cover 2a with a seal member 19 interposed therebetween. 2b. Note that the steering handle 4 is the lower cover 2
a, an air inlet 2 that guides outside air into the engine cover 2 at the rear upper portion of the upper cover 2b.
0 and a waterproof cover 21 also serving as a raising handle. The clutch control lever 51 of the clutch device 52 is rotatably mounted on a stay 53 projecting from the lower cover 2a toward the front of the engine 3. And, the clutch control lever 51
Is rotated back and forth as indicated by the arrow A in FIG. 1, thereby switching the clutch mechanism 13 via the clutch control rod 50 to switch the rotation direction of the propeller shaft 8 and the propeller 9 between forward, reverse and neutral. . The engine 3 is a single-cylinder engine of, for example, a four-cycle OHV type. The engine 3 is, for example, divided into upper and lower parts, and is constituted by joining a lower crankcase 23a and an upper cylinder block 23b. Having. The engine case 23 is fixed on an extension case 22 provided at the upper end of the drive shaft housing 6. A cylindrical cylinder sleeve 24 is formed integrally with the cylinder block 23b and extends rearward (leftward in FIG. 2) in a direction perpendicular to the crankshaft 10. A cylinder head 25 is attached to the rear end of the cylinder sleeve 24. And a head cover 26 are provided. A cylinder bore 27 extending in a direction perpendicular to the crankshaft 10 is formed inside the cylinder sleeve 24, and a combustion chamber 28 matching the cylinder bore 27 is formed in the cylinder head 25. In the cylinder head 25, the combustion chamber 28
, An intake port 41 and an exhaust port 42 are formed. In the cylinder head 25, both ports 41, 4 are provided.
An intake valve 43 and an exhaust valve 44 for opening and closing the valve 2 are arranged, and a valve train 45 for opening and closing these valves 43 and 44 is also arranged. On the other hand, an oil pan 30 is formed at the bottom of the crankcase 23a, and a support 32 for the crankshaft 10 is provided substantially at the center of the oil pan 30. The crankshaft 10 is rotatably supported in the vertical direction by a metal bearing 35 provided on the support portion 32 and a ball bearing 36 provided on the cylinder block 23b side. A pair of webs 10a and 10b are formed at a substantially middle portion of the crankshaft 10 so as to be vertically separated from each other.
Meanwhile, the crankpin 10c is provided eccentrically. Further, a piston 37 is slidably inserted into the cylinder bore 27, and a piston pin 37a of the piston 37 and
The crankpin 10c of the crankshaft 10 is connected by a connecting rod 38, whereby the cylinder bore 2
The reciprocating motion of the piston 37 in 7 is converted into the rotational motion of the crankshaft 10. Further, at the upper end of the crankshaft 10 located above the engine 3, for example, a flywheel magneto device 39 as a power generating device and a rope recoil type engine starting device 40 are provided. FIG. 3 is a sectional view taken along the line III-III in FIG. As shown in FIG. 3, a carburetor 55 is connected to an upper surface of the cylinder head 25 via an intake pipe 54. A downstream side of the carburetor 55 communicates with the intake port 41, and an intake pipe 56 is connected to an upstream side of the carburetor 55. As is apparent from FIG. 3, the carburetor 55 is arranged to be inclined in a direction crossing the reciprocating direction of the piston 37 in plan view. As shown in FIGS. 2 to 4, the air inlet 20 is formed in the upper cover 2 b above the carburetor 55, and the outside air sucked from the air inlet 20 is supplied to the upper cover 2 b and the engine 3. The air is sucked into the carburetor 55 through a space formed therebetween (for example, see FIG. 2) and an intake pipe 56 arranged in this space. And
The intake pipe 54, the carburetor 55, and the intake pipe 56 constitute an engine intake system 57. FIG. 4 is a diagram showing the clutch device 52 and the throttle control device 58. FIG. 5 is an enlarged plan view of the carburetor 55. As clearly shown in FIG. 4, the upper height of the carburetor 55 is set to be substantially the same as the upper height of the engine 3 on the boat 17 side, in the figure, on the right side. 3 to 5, a throttle valve is disposed in an intake passage formed in the carburetor 55 (none of them is shown). The throttle valve has a shaft 59 arranged in a vertical direction and a shaft end protruding upward. One end of a throttle lever 60 that is, for example, oval and rotatable in a horizontal plane is fixed to the protruding portion of the shaft 59. A pin 60 a protrudes from the other end of the throttle lever 60 to form a driven portion 61. On the other hand, on the side of the carburetor 55, a pulley 62 constituting a throttle control device 58 is arranged. The pulley 62 is rotatably supported on a horizontal plane, and a throttle cable 63 extending from the throttle grip 5.
Is wound. The throttle cable 63 is composed of two cables, for example, “pull” and “return”.
Is rotated. Note that a cable holder 64 is fixed to the cylinder head 25 and holds the throttle cable 63. The carburetor 55 has a throttle control device 5
8 is provided with a throttle control lever 65 which is a throttle opening / closing means. The throttle control lever 65 is fixed to the outer peripheral portion of the pulley 62 so as to rotate integrally therewith, and is arranged such that the rotation center portion (center of the pulley 62) is located above the intake pipe 54. Then, the throttle control lever 65 rotates in the horizontal direction together with the pulley 62, and this operation (rotation)
At this time, its shape and arrangement are set so as not to protrude outside the engine intake system 57. Further, the driven portion 61 of the throttle lever 60 is disposed so as to be closer to the center of the engine 3 than the center of rotation of the throttle control lever 65. A guide groove 66 is formed in the throttle control lever 65. A pin 60 a of a driven portion 61 formed at the end of the throttle lever 60 is formed in the guide groove 66.
Are engaged. The rotation of the throttle control lever 65 causes the throttle lever follower 6 to rotate.
The first pin 60a moves in the guide groove 66 to rotate the throttle lever 60. The guide groove 66 is provided so that the opening of the throttle lever 60 is smaller than the opening of the throttle grip 5 when the engine 3 is operating at a low speed, and the opening is smaller than the opening of the throttle grip 5 when the engine 3 is operating at a high speed. In a non-linear manner so that the opening degree of the lever 60 is equal or large, that is, in such a manner that the ratio between the opening degree of the throttle grip 5 and the opening degree of the throttle lever 60 is non-linear,
For example, in the present embodiment, it is formed in a “H” shape. The outboard motor 1 is provided with a throttle opening control mechanism 67 for controlling the opening of the throttle when the clutch mechanism 13 is in neutral. As shown in FIGS. 3 to 5, the control mechanism 67 includes a throttle rod 68 having one end rotatably mounted on a base end of a throttle control lever 65, and a throttle rod 6.
8 has a throttle limiter lever 69 having an upper end pivotally attached to the other end and a stopper 69a at the lower end. On the other hand, a clutch control rod 50 having one end connected to a clutch control lever 51 is provided.
Is pivotally attached to the upper end of the lever portion 70a of the clutch lever 70. A stopper projection 70b is formed on the upper end of the lever 70a. The stopper 69a at the lower end of the throttle limiter lever 69 is configured to abut on the stopper projection 70b only when the clutch lever 70 is in the neutral position. Next, the operation of the present embodiment will be described. When the throttle grip 5 is turned, for example, to the speed increasing side, the pulley 62 is turned clockwise in the horizontal direction by the throttle cable 63 as shown by an arrow B in FIG. As the pulley 62 rotates, the throttle control lever 65 also rotates clockwise in the horizontal direction. When the throttle control lever 65 rotates, the inside of the guide groove 66 is moved by the throttle lever follower 61.
Is moved, and the throttle lever 60 is rotated clockwise. Here, the throttle control lever 6
5 is formed in a non-linear shape such as a "H" shape so that the opening of the throttle lever 60 can be set smaller than the opening of the throttle grip 5 when the engine 3 is running at a low speed. Fine adjustment of the engine speed is easily possible. In addition, the opening of the throttle lever 60 can be set to be equal to or larger than the opening of the throttle grip 5 during high-speed operation of the engine 3, and the opening and closing operation can be performed with an appropriate opening of the throttle grip 5. That is, the drivability of the engine 3 is improved. Then, the throttle control lever 6
5 is arranged above the intake pipe 54, and the throttle control lever 65 is horizontally rotated together with the pulley 62 so that the throttle control lever 65 does not protrude outside the engine intake system 57 during operation (rotation). In addition, the shape and arrangement of the throttle control device are set so that the driven portion 61 of the throttle lever 60 is located closer to the center of the engine 3 than the rotation center of the throttle control lever 65, so that the structure of the throttle control device 58 becomes compact. As a result, the entire outboard motor 1 becomes compact. Further, by directly winding the throttle cable 63 extending from the throttle grip 5 around the pulley 62 and operating the throttle control lever 65,
The rod, link device, and the like, which have been conventionally used, become unnecessary, and play and play are less likely to occur, thereby improving maintainability. Next, the throttle opening control mechanism 67 will be described. As shown by an arrow B in FIG. 6, when the pulley 62 is rotated clockwise by the throttle cable 63, the throttle rod 68 pivotally attached to the base end of the throttle control lever 65 moves toward the arrow C, As shown by arrow D, the throttle limiter lever 69 is rotated counterclockwise. Then, with the rotation of the throttle limiter lever 69, the stopper 69a provided at the lower end thereof also rotates. Here, the stopper portion 69a is provided with the stopper projection 7 only when the clutch lever 70 is in the neutral position.
0b, the rotation of the throttle limiter lever 69 is restricted when the clutch lever 70 is in the neutral position, as a result, the rotation of the pulley 62 and the throttle control lever 65 is also restricted as shown in FIG. Thus, the opening of the throttle valve provided in the intake passage of the carburetor 55 is regulated, the engine idling speed during neutral is suppressed, and damage to the engine 3 due to overspeed can be prevented. As shown in FIG.
When the clutch lever 70 is in the forward or reverse position, the stopper 69a does not come into contact with the stopper projection 70b, so that the rotation of the throttle limiter lever 69 is not restricted.
Any throttle valve opening can be obtained. As described above, according to the outboard motor of the present invention, the reciprocating motion of the piston in the cylinder bore extending in the direction perpendicular to the crankshaft is provided by vertically setting the crankshaft. A four-stroke engine that is converted into rotational motion of the crankshaft and transmitted to a propeller via a drive shaft, an engine intake system including an intake pipe, a carburetor, and an intake pipe, connected to a cylinder head of the engine; An outboard motor including an engine cover having an air inlet for housing an engine, and an engine starting device, wherein the carburetor is provided with a throttle control device having a throttle opening / closing means. And the outside air sucked from the air inlet above. Since the carburetor sucking through the intake pipe is arranged above the cylinder head of the engine, and the throttle opening / closing means is arranged so as not to protrude outside the engine intake system at the time of its operation, the throttle control device is compact. And the whole outboard motor becomes compact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a right side view of an outboard motor showing one embodiment of an outboard motor according to the present invention. FIG. 2 is a longitudinal sectional view of an engine portion of the outboard motor shown in FIG. FIG. 3 is a sectional view taken along the line III-III in FIG. 2; FIG. 4 is a side view showing a clutch device and a throttle control device. FIG. 5 is an enlarged plan view of the carburetor. FIG. 6 is an enlarged plan view of the carburetor for explaining the operation of the throttle control device. FIG. 7 is a side view of a throttle limiter lever and a clutch lever illustrating the operation of a throttle opening control mechanism. [Description of Signs] 1 Outboard motor 3 Engine 5 Throttle grip (Throttle operating means) 6 Drive shaft housing 13 Clutch mechanism 23 Engine case 25 Cylinder head 40 Engine starter 54 Intake pipe 55 Carburetor 56 Intake pipe 57 Engine intake system 58 Throttle Control device 60 Throttle lever 61 Throttle lever follower 62 Pulley 63 Throttle cable 65 Throttle control lever (throttle opening / closing means) 66 Guide groove 67 Throttle opening control mechanism

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-25299 (JP, A) JP-A-8-68337 (JP, A) JP-A-8-68335 (JP, A) JP-A-8-683 100667 (JP, A) JP-A-7-208196 (JP, A) JP-A-7-77059 (JP, A) JP-A-2-274690 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B63H 20/12 F02B 67/00

Claims (1)

(57) [Claim 1] A crankshaft is provided vertically, and a reciprocating motion of a piston in a cylinder bore extending in a direction orthogonal to the crankshaft is converted into a rotational motion of the crankshaft to drive the crankshaft. A four-stroke engine transmitted to a propeller via a shaft, an engine intake system including an intake pipe, a carburetor, and an intake pipe, connected to a cylinder head of the engine, and an air inlet for accommodating the engine. An outboard motor having an engine cover and an engine starting device, wherein the carburetor is provided with a throttle control device having a throttle opening / closing means, wherein the engine starting device is disposed above the engine, and the air introduction port is provided. The carburetor that sucks in the outside air taken in from the While located in the cylinder head above the serial engine, outboard motor, characterized in that arranged so as not to protrude outward from the engine intake system at the time of operating the throttle closing means.