Jet propelled watercraft

Patent metadata

Field	Value
Publication number	US-9725148-B2
Application number	US-201414487125-A
Country	US
Kind code	B2
Filing date	Sep 16, 2014
Priority date	Oct 31, 2013
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

A jet propelled watercraft includes a vessel body, a jet propulsion mechanism, a bucket, and a controller. The jet propulsion mechanism is configured to propel the vessel body. The controller is configured and programmed to control a thrust of the jet propulsion mechanism to propel the vessel body. The bucket is configured to move to a retracted position spaced away from the jet of water ejected from the jet propulsion mechanism and a jet receiving position to receive the jet of water ejected from the jet propulsion mechanism. The controller is configured and programmed to change an increase rate of the thrust in accordance with a forward speed of the vessel body until the thrust is increased to a predetermined value after the bucket has been moved from the retracted position to the jet receiving position.

First claim

What is claimed is:

1. A jet propelled watercraft comprising:
a vessel body;
a jet propulsion mechanism configured to propel the vessel body;
a controller configured and programmed to control a thrust of the jet propulsion mechanism to propel the vessel body; and
a bucket configured to move to a retracted position spaced away from a jet of water ejected from the jet propulsion mechanism and to a jet receiving position to receive the jet of water ejected from the jet propulsion mechanism; wherein
the controller is configured and programmed to increase the thrust until the thrust is increased to a predetermined value after the bucket has been moved from the retracted position to the jet receiving position;
the controller is configured and programmed to increase the thrust at a rate that is changing in accordance with a forward speed of the vessel body; and
the controller is configured and programmed to control the thrust using a throttle opening degree that is calculated by multiplying a target throttle opening degree and a regulation coefficient.

2. The jet propelled watercraft according to claim 1 , wherein the controller is configured and programmed to increase the rate in accordance with a reduction in the forward speed until the thrust is increased to the predetermined value.

3. The jet propelled watercraft according to claim 1 , wherein the controller is configured and programmed to reduce the rate in accordance with a reduction in the forward speed until the thrust is increased to the predetermined value.

4. The jet propelled watercraft according to claim 1 , further comprising:
an engine configured to drive the jet propulsion mechanism; and
a throttle operating member configured to regulate the target throttle opening degree of the engine; wherein
the controller is configured and programmed to set the predetermined value in accordance with an operating amount of the throttle operating member.

5. The jet propelled watercraft according to claim 4 , wherein the controller is configured and programmed to determine the predetermined value regardless of the forward speed at which the bucket has been moved from the retracted position to the jet receiving position.

6. The jet propelled watercraft according to claim 1 , further comprising:
an engine configured to drive the jet propulsion mechanism, the engine including a crankshaft; wherein
the jet propulsion mechanism includes an impeller shaft coupled to the crankshaft and an impeller attached to the impeller shaft; and
the controller is configured and programmed to control the thrust by regulating a rotation speed of the impeller.

Assignees

• Yamaha Motor Co Ltd

Inventors

• Kinoshita Yoshimasa

Classifications

• B63H21/14

  relating to internal-combustion engines {(of outboard type B63H20/00)} · CPC title

• B63H11/08

  of rotary type · CPC title

• B63H11/11 Primary

  with bucket or clamshell-type reversing means · CPC title

• B63H2011/081

  with axial flow, i.e. the axis of rotation being parallel to the flow direction · CPC title

• B63H21/21

  Control means for engine or transmission, specially adapted for use on marine vessels · CPC title