Automatic trim controller for marine propulsion unit
AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsToshihiko Uenage, Yoshihide Hirano
Life of this patent
Estimating the term…
Abstract
Several embodiments of automatic trim controls for marine outboard drives for maintaining the optimum trim angle under all running conditions. The velocity of the watercraft is determined and the outboard drive is trimmed up as long as the velocity continues to increase and then is trimmed down so as to maintain the highest velocity possible for a given running condition. Several different computer programs are illustrated and described for achieving this purpose and a number of different embodiments of power units for controlling the trim condition are also described, some hydraulic and other mechanical.
Claims12
In a watercraft comprising a hull, a propulsion unit adapted to be submerged in the water for propelling said hull, means for mounting said propulsion unit upon said hull for pivotal movement about a generally horizontally extending trim axis for adjusting the trim angle of said propulsion unit, power means for pivoting said propulsion unit about said trim axis for adjusting said propulsion unit trim angle, the improvement comprising means for controlling said power means to control the trim angle to achieve maximum watercraft speed for a given speed of said propulsion unit comprising means for sensing a rate of change in velocity of the watercraft, and means for operating said power means for adjusting said trim angle in response to a sensed rate of change in velocity to maximize the speed of the watercraft for a given propulsion unit speed.
In a watercraft comprising a hull, a propulsion unit adapted to be submerged in the water for propelling said hull and having a cooling water inlet, means for mounting said propulsion unit upon said hull for pivotal movement about a generally horizontally extending trim axis for adjusting the trim angle of said propulsion unit, power means for pivoting said propulsion unit about said trim axis for adjusting said propulsion unit trim angle, the improvement comprising means for sensing the pressure of water at said propulsion unit cooling water inlet, means for controlling said power means to maintain the appropriate trim angle for all running conditions comprising means for sensing a rate of change in velocity, and means for operating said power means for adjusting said trim angle in response to a sensed rate of change in velocity, and means for operating said power unit for trimming down said propulsion unit when the coolant pressure falls below a predetermined value.
A method of trimming a watercraft comprising a hull, a propulsion unit adapted to be submerged in the water for propelling the hull and having a cooling water inlet, means for mounting the propulsion unit upon the hull for pivotal movement about a generally horizontally extending trim axis for adjusting the trim angle of the propulsion unit, power means for pivoting said propulsion unit about the trim axis for adjusting the propulsion unit trim angle, said method comprising measuring the pressure of water at the cooling water inlet, controlling the power means to maintain the appropriate trim angle for all running conditions comprising the steps of measuring a change in velocity, and operating the power means for adjusting the trim angle in response to a measured change of velocity, and trimming down the propulsion unit when the coolant pressure falls below a predetermined value.
Dependencies are inferred from the claim text.