The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1992
Filed:
Jun. 19, 1990
Naoyuki Moriya, Kobe, JP;
Makoto Sameshima, Takasago, JP;
Shin Caterpillar Mitsubishi Ltd., Minato, JP;
Abstract
A torque control system for variable delivery pumps receiving torque from an engine employs a signal related to an engine torque available at each engine speed setting to control the torque, and thus the amount of engine power that is absorbed by the variable delivery pumps. In a low-power regime, wherein the fuel injected into the engine is less than maximum, torque control is effected by comparing the available torque with an amount of torque that would be available at maximum fuel injection. In a high-power regime, wherein the fuel injected is at least a predetermined value, torque contol is effected by comparing the available torque with an amount of torque that is available at a combination of a set engine speed and an actual engine speed. A bias circuit biases the stable speed operating point a small amount below the maximum speed, whereby improved fuel economy is attained. In a system with more than one variable delivery pump, when less than the full number of pumps is employed, control is effected in the low-power regime, even though all pumps in service are receiving maximum fuel.