Marine propulsion – Means to control the supply of energy responsive to a sensed...
Reexamination Certificate
2001-08-08
2002-11-12
Basinger, Sherman (Department: 3617)
Marine propulsion
Means to control the supply of energy responsive to a sensed...
C440S002000, C440S042000, C440S087000
Reexamination Certificate
active
06478638
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a jet-propulsion watercraft which ejects water rearward and planes on a water surface as the resulting reaction. More particularly, the present invention relates to a jet-propulsion watercraft that can maintain steering capability even when the throttle is operated in the closed position and propulsion force is thereby reduced.
2. Description of the Related Art
In recent years, so-called jet-propulsion personal watercraft (PWC) have been widely used in leisure, sport, rescue activities, and the like. The personal watercraft is configured to have a water jet pump that pressurizes and accelerates water sucked from a water intake generally provided on a bottom of a hull and ejects it rearward from an outlet port. Thereby, the personal watercraft is propelled.
In the personal watercraft, in association with a steering handle of a general bar type, a steering nozzle provided behind the outlet port of the water jet pump is swung either to the right or left, to change the ejecting direction of the water to the right or to the left, thereby turning the watercraft to the right or to the left.
A deflector is retractably provided behind the steering nozzle for blocking the water ejected from the steering nozzle. The deflector is moved downward to deflect the ejected water forward, and as the resulting reaction, the personal watercraft moves rearward. In some watercraft, in order to move rearward, a water flow is formed so as to flow from an opening provided laterally of the deflector along a transom board to reduce the water pressure in an area behind the watercraft.
In the above-described personal watercraft, when the throttle is moved to a substantially fully closed position and the water ejected from the water jet pump is thereby reduced, during forward movement and rearward movement, the propulsion force necessary for turning the watercraft is correspondingly reduced, and the steering capability of the watercraft is therefore reduced until the throttle is re-opened.
To address the above-described condition with a mechanical structure, the applicant disclosed a jet-propulsion personal watercraft comprising a steering component for an auxiliary steering system which operates in association with the steering handle in addition to a steering nozzle for the main steering system in Japanese Patent Application No. Hei. 2000-6708.
Also, for the purpose of achieving a lightweight watercraft, the applicant disclosed a jet-propulsion personal watercraft in Japanese Patent Application No. Hei. 2000-173232, in which a sensor is adapted to detect a throttle-close operation, a steering operation, or the like, and an engine speed is increased according to the detection.
SUMMARY OF THE INVENTION
The present invention addresses the above-described condition, and an object of the present invention is to provide a jet-propulsion watercraft that can maintain steering capability according to the cruising speed thereof even while an operation which closes the throttle (hereinafter referred to as “throttle-close operation”) is performed and the amount of water ejected from a water jet pump is thereby reduced.
According to the present invention, there is provided a jet-propulsion watercraft comprising: a water jet pump that pressurizes and accelerates sucked water and ejects the water from an outlet port provided behind the water jet pump to propel the watercraft as a reaction of the ejecting water; an engine for driving the water jet pump, the engine being provided with a throttle valve; a steering operation means that operates in association with a steering nozzle of the water jet pump; a throttle lever for being operated to open/close the throttle valve; a first connecting member for connecting the throttle lever to the throttle valve; and a second connecting member for connecting the steering operation means or a rotational shaft of the steering operation means to the throttle lever so as to operate the throttle lever to cause the throttle valve to be opened according to an steering operation of the steering operation means.
In a jet-propulsion watercraft of the present invention, even while the throttle-close operation is performed but the steering operation means is operated, the second connecting member operates the throttle lever to a direction to open the throttle valve according to the steering amount or a rotational angle of the rotational shaft according to the steering. Since the engine speed is increased according to the amount of the throttle lever operation, the water sufficient to turn the watercraft is ejected from the water jet pump, that is, a sufficient propulsion force is thereby obtained. Consequently, the steering capability can be maintained even while the throttle-close operation is performed.
Herein, control for increasing the engine speed is referred to as “steering assist mode control”, and the “throttle-close operation” is to be understood to signify an operation performed to bring the throttle toward a closed position by a predetermined amount or more.
The second connecting member may be constituted by a push-pull cable. One end portion of the cable is connected to a portion protruded directly or indirectly on an outer peripheral face of the rotational shaft of the steering handle. Since the one end portion of the push-pull cable is thus connected to the portion protruded on the outer peripheral face of the rotational shaft, the rotational angle of the rotational shaft according to the steering operation can be converted into the movement of the cable at a greater rate. Also, since advancement/retraction of the other end portion of the operated cable operates the throttle lever to cause the throttle to be opened, the second connecting member can be constituted by a simple general member.
As the second connecting member described above, a pair of push-pull cables are provided. These cables are pushed and pulled toward opposite directions with respect to each other according to the rotation of the rotational shaft. One of the other end portions of these cables, i.e., the end portions of the cables connected to the throttle lever, is advanced/retracted to operate the throttle lever to cause the throttle to be opened. When the steering operation means is steered to the right or to the left, the throttle lever can be operated to cause the throttle to be opened regardless of the steering direction.
According to the present invention, there is also provided a jet-propulsion watercraft comprising: a water jet pump that pressurizes and accelerates sucked water and ejects the water from an outlet port provided behind the water jet pump to propel the watercraft as a reaction of the ejecting water; an engine for driving the water jet pump; a steering operation means that operates in association with a steering nozzle of the water jet pump; a first air-fuel mixture supplying system for supplying an air-fuel mixture to the engine through a first air-fuel mixture supplying passage, the first air-fuel mixture supplying system being provided with a first throttle valve; a second air-fuel mixture supplying system for supplying an air-fuel mixture to the engine through a second air-fuel mixture supplying passage; and a throttle lever for performing an open/close operation of the first throttle valve, and the second air-fuel mixture supplying system is adapted to increase the air-fuel mixture supplied to the engine during the operation of the steering operation means, thereby increasing the engine speed.
According to the jet-propulsion watercraft of the present invention, while the throttle-close operation is performed, and thereby the air-fuel mixture is not supplied from the first air-fuel mixture supplying system generally provided in the engine, the air-fuel mixture is supplied to the engine from the second air-fuel mixture supplying system while the steering operation means is operated. Thereby, the engine speed is increased. Therefore, the water sufficient to turn the watercraft is ejected from the water
Matsuda Yoshimoto
Takahashi Keiji
Basinger Sherman
Kawasaki Jukogyo Kabushiki Kaisha
Marshall Gerstein & Borun
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