JP2002054461A - Throttle structure of outboard motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the throttle structure of an outboard motor to facilitate operation to open and close a throttle valve by simple structure. SOLUTION: A throttle drum 45 is integrally rotatably situated at the end part of a throttle grip 25, and the ends on one side of a main throttle cable 46, and a subthrottle cable 47 are connected to the throttle drum 45 with its center nipped therebetween. Meanwhile, a throttle valve 50 is pivotally supported at a carburetor 41 by a throttle shaft 51 having a return spring 53. A throttle shaft plate 52 is rotatably integrally mounted on the end part of the throttle shaft 51 protruding externally of the carburetor 41. The throttle shaft plate 52 is extended to both sides centering around the throttle shaft 51. The respective terminals of the main throttle cable 46 and the subthrottle cable 47 are connected to the two end parts thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a throttle structure for an outboard motor.

[0002]

2. Description of the Related Art Some engines adjust the output by opening and closing a throttle valve in a throttle body or a carburetor to increase or decrease the amount of inflow air. The opening and closing operation of the throttle valve is usually performed by remote control via a cable or a rod.

FIG. 8 shows an example of a carburetor used for an outboard motor. As shown in FIG.
A throttle valve 3 is rotatably supported by a throttle shaft 4 in the intake passage 2 inside, and a throttle shaft plate 5 is integrally mounted on an end of the throttle shaft 4 protruding outside the carburetor 1. One end of a throttle cable 6 is connected to the throttle shaft plate 5, and the throttle valve 3 is opened by pulling the throttle cable.

[0004] A return spring 7 is provided on the throttle shaft 4, and a throttle cable 6 is provided.
When the pulling operation is loosened, the throttle valve 3 is closed by the return spring 7.

FIG. 9 shows another example of a carburetor used for an outboard motor, for example. As shown in FIG. 9, a throttle valve 13 is rotatably supported by a throttle shaft 14 in an intake passage 12 in a carburetor 11, and a throttle shaft plate 15 is attached to an end of the throttle shaft 14 protruding outside the carburetor 11. Can be On the other hand, a throttle drum 16 is provided separately from the carburetor 11, and the throttle drum 16 and the throttle shaft plate 15 are operatively connected by a rod 17. One end of a main throttle cable 18 and one end of a sub throttle cable 19 are connected to the throttle drum 16, and the main throttle cable 18 is pulled to operate the throttle valve 13.
Is opened, and the throttle valve 13 is closed by pulling the sub-throttle cable 19. This opening and closing system is generally called a forced opening and closing system.

[0006]

However, in the case of a system in which the throttle valve is closed using a return spring, if the throttle shaft is stuck due to salt damage or the like, the opening and closing operation of the throttle valve becomes heavy, resulting in poor operability.

In the case of the forced opening / closing system, the structure is complicated, the number of parts is large, and the number of adjustment points is large.

The present invention has been made in consideration of the above circumstances, and has as its object to provide a throttle structure for an outboard motor which has a simple structure and facilitates opening and closing operations of a throttle valve.

[0009]

According to a first aspect of the present invention, there is provided a throttle structure for an outboard motor according to the present invention. A throttle cable for adjusting the engine output is provided at the end thereof so as to be rotatable in the circumferential direction, a carburetor is provided in the engine, and a throttle valve provided on the carburetor extends from the throttle grip to a throttle cable. In an outboard motor that is opened and closed using a throttle drum, a throttle drum is pivotally provided at an end of the throttle grip, and one end of each of a main throttle cable and a sub-throttle cable is connected to the throttle drum with the center thereof interposed therebetween. On the other hand, the throttle valve is a throttle with a return spring. A throttle shaft is rotatably supported on the carburetor by a torsion shaft, and a throttle shaft plate is attached to the end of the throttle shaft protruding out of the carburetor, and the throttle shaft plate extends on both sides around the throttle shaft. , To which both ends of the main throttle cable and the sub throttle cable are connected.

[0010] In order to solve the above-mentioned problem, an engagement hole is formed at an end of the throttle shaft plate on the side to which the end of the sub-throttle cable is connected, An end pin provided at the end of the sub-throttle cable is arranged so as to be able to engage with the engagement hole, and the engagement hole is provided so that the main throttle cable and the return spring operate without hindrance and the throttle valve operates. In a state where the throttle shaft plate is smoothly opened and closed, the position and the shape of the throttle shaft plate are set so that the end pin at the end of the sub-throttle cable does not lock in any position, while the throttle valve is smoothly opened and closed. If not, close the throttle grip to operate the sub throttle. Buru is pulled engaged end pin of the terminal in the engaging hole of the throttle shaft plate,
The throttle valve is forcibly closed.

Further, in order to solve the above-mentioned problems,
According to a third aspect of the present invention, a choke valve is rotatably supported by a choke shaft upstream of the throttle valve of the carburetor, and a choke shaft plate is rotated at an end of the choke shaft protruding outside the carburetor. In addition to being integrally mounted, the carburetor is provided with restricting means for restricting the position of the throttle valve when using a choke, and the restricting means includes a protrusion integrally provided on the throttle shaft plate and the choke shaft plate. The throttle valve is positioned at the opening when the engine is started with the protrusion of the throttle shaft plate abutting on the stopper of the choke shaft plate in a state where a choke is used. It is set to do.

[0012]

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, the outboard motor 21 has a box-shaped engine cover 22 at the uppermost portion, and a vertical (vertical) engine 23 is housed therein. A tiller handle 24 extends forward from the front lower portion (right side in the figure) of the engine 23, and a throttle grip 25 for adjusting the engine output is provided at the tip thereof.

A drive shaft housing 26 is provided below the engine cover 22, and a gear case 27 is provided below the drive shaft housing 26. Inside the gear case 27 is a propeller shaft 2
8, a propeller 29 is provided at the rear end.

The engine 23 includes a crankshaft 30.
Are provided vertically (vertically) so as to face almost vertically. The drive shaft 3 connected to the lower end of the crankshaft 30 is provided in the drive shaft housing 26.
1 extends downward, and the lower end of the drive shaft 31 is connected to the propeller shaft 28 via the bevel gear 32. The output of the engine 23, that is, the rotation of the crankshaft 30 is transmitted to the propeller shaft 28 via the drive shaft 31 and the bevel gear 32, and rotates the propeller 29.

The upper portion of the drive shaft housing 26 is rotatably supported by a rotation support portion 33a of a clamp bracket 33, and the clamp bracket 33 is fixed to a transom 34a of the boat 34. That is, the outboard motor 21 is provided so as to be rotatable through substantially 360 ° with respect to the boat 34, and steers the boat 34 by changing the direction of the entire outboard motor 21 by swinging the tiller handle 24 in the horizontal direction. It is configured to be able to.

On the other hand, the engine 2 used in this embodiment
Reference numeral 3 denotes, for example, a 4-cycle single-cylinder engine. The engine 23 includes a vertically split crankcase 35 disposed on the front side (the right side in FIG. 1) of the outboard motor 21 and a rear side of the crankcase 35 (FIG. To the left)
A cylinder block 36 formed integrally with the upper portion of the crankcase 35, and a cylinder head 37 disposed on the rear side (left side in FIG. 1) of the cylinder block 36
It is composed of The engine 23 is fixed on an extension case 38 provided at the upper end of the drive shaft housing 26. At the upper end of the crankshaft 30, a flywheel magneto device 39 for power generation and a rope recoil type engine starting device 40 are provided.

FIG. 2 is a plan view of the engine 23. FIG.
As shown in FIG. 3, a carburetor 41 constituting an intake device is disposed above the cylinder block 36, and a downstream side thereof is connected to an intake port (not shown) opened on the upper surface of the cylinder head 37 via an inlet pipe 42. At the same time, a silencer 43 is connected to the upstream side of the carburetor 41.

FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1 and shows the structure of the tiller handle 24. As shown in FIG. 3, a throttle grip 25 is attached to the free end of the tiller handle 24 so as to be rotatable in the circumferential direction. From the throttle grip 25, a throttle rod 44 provided integrally with the throttle grip 25 extends into the tiller handle 24, and a throttle drum 45 is provided integrally with the end of the throttle rod 25.

Although not shown in detail, one end of each of a main throttle cable 46 and a sub-throttle cable 47 is connected to the throttle drum 45 with its center interposed therebetween. One of the cables is pulled. Then, as shown in FIG. 2, the main throttle cable 46 and the sub throttle cable 47 are guided into the engine cover 21 and extend toward the carburetor 41. The main throttle cable 46 and the sub throttle cable 47 are held by a cable holder 48 near the carburetor 41.

FIG. 4 is an enlarged plan view of the carburetor 41, and FIG. 5 is a view taken in the direction of the arrow V in FIG. As shown in FIGS. 4 and 5, in an intake passage 49 in the carburetor 41, a throttle valve 50 that adjusts the output of the engine 23 by increasing or decreasing the amount of air flowing in the intake passage 49 is rotatable by a throttle shaft 51. And carburetor 41
A throttle shaft plate 52 is integrally attached to the end of the throttle shaft 51 protruding outward. A return spring 5 is provided on the throttle shaft 51.
3 are provided. FIG. 4 shows a state in which the throttle valve 50 is closed (fully closed). FIG. 6 shows a state where the throttle valve 50 is opened (fully opened).

Further, a choke valve 54 for adjusting the amount of air flowing into the intake passage 49 at the time of starting the engine 23 to temporarily increase the air-fuel ratio at the upstream of the throttle valve 50 is rotatably pivoted by a choke shaft 55. A choke shaft plate 56 is attached to the end of the choke shaft 55 which is supported and protrudes out of the carburetor 41. Then, as shown in FIG. 2, a choke knob 57 provided outside the outboard motor 21 is operatively connected to a choke shaft plate 56 via a choke rod 58.

The throttle shaft plate 52 extends, for example, on both sides in the width direction of the carburetor 41 around the throttle shaft 51, and one end of the throttle shaft plate 52 is connected to an end of a main throttle cable 46. Then, the throttle grip 25 is opened and the main throttle cable 46 is opened.
Is pulled, the throttle valve 50 opens. A return spring 5 is provided on the throttle shaft 51.
3, the return spring 53 automatically closes the throttle valve 50 when the opening operation of the throttle grip 25 is loosened.

The carburetor 41 is provided with a regulating means for regulating the position of the throttle valve 50 when using the choke. More specifically, as shown in FIG.
9 are integrally provided, and a stopper portion 60 for position regulation is extended from the choke shaft plate 56.
Then, the throttle valve 50 is set to the opening at the time of starting the engine 23 in a state where the projection 59 of the throttle shaft plate 52 is in contact with the stopper portion 60 of the choke shaft plate 56 in a state where the choke is used. .

On the other hand, the throttle shaft plate 52
An engagement hole 61 is formed at the end opposite to the main throttle cable 46 mounting portion with the throttle shaft 51 interposed therebetween.
An end pin 62 provided at the end of 7 is arranged to be engageable. When the main throttle cable 46 and the return spring 53 are operated without hindrance and the throttle valve 50 is smoothly opened and closed, the engagement hole 61 is provided at the end of the sub throttle cable 47 regardless of the position of the throttle shaft plate 52. End pin 6
The position and shape are set to, for example, an arc-shaped long hole so that 2 does not lock. That is, as long as the throttle valve 50 opens and closes smoothly, the throttle grip 2
Sub-throttle cable 47 which moves forward and backward by the operation of 5
Does not interfere with the opening and closing operation of the throttle valve 50.

However, if the operation of the main throttle cable 46 and the return spring 53 becomes heavy and the opening and closing of the throttle valve 50 cannot be performed smoothly due to some reason such as salt in seawater, the throttle grip 25 must be moved. By forcibly closing the sub-throttle cable 47, the end pin 62 at the end thereof is pulled.
Is set so as to be locked in the engagement hole 61 of the throttle shaft 51 and forcibly close the throttle valve 50.
(See FIG. 7). At this time, the throttle valve 50 is set so as to be able to be closed as far as the opening at the time of starting the engine 23 (when using the choke), and the engine 23 does not stop even if the throttle grip 25 is forcibly closed. .

As a setting method, for example, as shown in FIG.
Can be made possible by adjusting the length of the sub-throttle cable 47 in a state in which the sub-throttle cable 47 is in contact with the stopper portion 60 of the choke shaft plate 56 when the choke is used.

Next, the operation of the present embodiment will be described.

The opening and closing operation of the throttle valve 50 is performed using two throttle cables, and one of them is used only for the forced closing operation. The structure can be simplified, the number of parts and the number of assembly steps can be reduced, and the throttle valve 50 can be reliably closed even if the operation of the main throttle cable 46 and the return spring 53 becomes heavy for some reason.

Further, since the sub-throttle cable 47 which normally moves by operating the throttle grip 25 does not interfere with the opening / closing operation of the throttle valve 50, the opening / closing of the throttle valve 50 can be smoothly performed with a light feeling.

Further, a means for restricting the position of the throttle valve 50 when the choke is used is provided, and when the throttle valve 50 is forcibly closed, the throttle valve 50 is closed with an opening limit when the engine 23 is started (when the choke is used). With this setting, the length adjustment of the sub-throttle cable 47 is easily performed.

[0032]

As described above, according to the throttle structure of an outboard motor according to the present invention, a tiller handle extends forward in front of the engine, and a throttle grip for adjusting the engine output is provided at the tip thereof. An outboard motor provided with a carburetor in the engine and opening and closing a throttle valve provided on the carburetor using a throttle cable extending from the throttle grip. A throttle drum is provided at one end of the throttle drum and one end of each of a main throttle cable and a sub throttle cable is connected to the throttle drum with the center thereof interposed therebetween, while the throttle valve is connected to a throttle shaft provided with a return spring. The carburetor turns The throttle shaft plate is pivotally attached to the end of the throttle shaft projecting out of the carburetor, and the throttle shaft plate extends to both sides around the throttle shaft. Also, since the respective ends of the sub-throttle cable are connected, the structure is simplified, the number of parts and the number of assembling steps can be reduced, and the throttle valve can be reliably closed.

Further, an engagement hole is formed at the end of the throttle shaft plate on the side to which the end of the sub-throttle cable is connected, and an end pin provided at the end of the sub-throttle cable is engaged with the engagement hole. The engagement hole is provided at any position of the throttle shaft plate in a state where the main throttle cable and the return spring operate without trouble and the throttle valve is smoothly opened and closed. Also, while setting the position and shape so that the end pin at the end of the sub-throttle cable does not lock, if the throttle valve does not open and close smoothly, the sub-throttle cable is pulled by closing the throttle grip. The end pin at the end is the throttle It engages the engagement hole of the plate, for which is set to forcibly close the throttle valve, together with the operation of the throttle valve is increased, also ensures the opening and closing of the throttle valve.

Further, a choke valve is rotatably supported by a choke shaft on the upstream side of the throttle valve of the carburetor, and a choke shaft plate is rotatably attached to an end of the choke shaft protruding outside the carburetor. At the same time, the carburetor is provided with restricting means for restricting the position of the throttle valve when using a choke, and the restricting means is extended from the projection integrally formed on the throttle shaft plate and the choke shaft plate. The throttle valve is set at the opening when the engine is started with the protrusion of the throttle shaft plate abutting against the stopper of the choke shaft plate using a choke. Did
When the throttle valve is forcibly closed, the length of the sub-throttle cable can be easily adjusted by setting the throttle valve so as to close the opening at the start of the engine as much as possible.

[Brief description of the drawings]

FIG. 1 is a right side view of an outboard motor showing one embodiment of a throttle structure for an outboard motor according to the present invention.

FIG. 2 is a plan view of the engine.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is an enlarged plan view of the carburetor (with the throttle valve closed).

FIG. 5 is a view taken in the direction of arrow V in FIG. 4;

FIG. 6 is an enlarged plan view of the carburetor (with the throttle valve opened).

FIG. 7 is an enlarged plan view of the carburetor (with chalk used).

FIG. 8 is a diagram showing an example of a carburetor used in a conventional outboard motor.

FIG. 9 is a diagram showing another example of a carburetor used in a conventional outboard motor.

[Description of Signs] 21 Outboard motor 23 Engine 24 Tiller handle 25 Throttle grip 41 Carburetor 45 Throttle drum 46 Main throttle cable 47 Sub throttle cable 50 Throttle valve 51 Throttle shaft 52 Throttle shaft plate 53 Return spring 54 Choke valve 55 Choke shaft 56 Choke shaft plate 59 Protrusion 60 Stopper 61 Engagement hole 62 End pin

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02M 1/02 B63H 21/26 K

Claims (3)

[Claims] 1. A tiller handle extends forward of an engine, and a throttle grip for adjusting engine output is provided at the end thereof so as to be rotatable in a circumferential direction thereof, and a carburetor is provided in the engine. In an outboard motor in which a throttle valve provided on the carburetor is opened and closed using a throttle cable extending from the throttle grip, a throttle drum is integrally provided at an end of the throttle grip, and the center of the throttle drum is provided on the throttle drum. The throttle valve is rotatably supported on the carburetor by a throttle shaft provided with a return spring, and the throttle shaft end protrudes out of the carburetor. Part The throttle shaft plate is attached integrally with the rotary shaft, the throttle shaft plate extends on both sides around the throttle shaft, and ends of the main throttle cable and the sub throttle cable are connected to both ends. Outboard motor throttle structure. 2. An engagement hole is formed at the end of the throttle shaft plate on the side to which the end of the sub-throttle cable is connected, and an end pin provided at the end of the sub-throttle cable is engaged with the engagement hole. The engagement hole is provided at any position of the throttle shaft plate in a state where the main throttle cable and the return spring operate without trouble and the throttle valve is smoothly opened and closed. Also, while setting the position and shape so that the end pin at the end of the sub-throttle cable does not lock, if the throttle valve does not open and close smoothly, the sub-throttle cable is pulled by closing the throttle grip. The end pin at the end is the throttle shaft 2. A throttle structure for an outboard motor according to claim 1, wherein said throttle structure is set so as to be engaged with an engagement hole of said boat and forcibly close said throttle valve. 3. A choke valve is rotatably supported by a choke shaft on the upstream side of the throttle valve of the carburetor, and a choke shaft plate is rotatably attached to an end of the choke shaft protruding outside the carburetor. At the same time, the carburetor is provided with restricting means for restricting the position of the throttle valve when using a choke, and the restricting means is extended from the projection integrally formed on the throttle shaft plate and the choke shaft plate. The throttle valve is set at the opening when the engine is started with the protrusion of the throttle shaft plate abutting against the stopper of the choke shaft plate using a choke. The outboard motor according to claim 1 or 2, Throttle structure.