ENGINE ROTATIONAL SPEED CONTROL APPARATUS

• US 20150291003A1
• Filed: 03/17/2015
• Published: 10/15/2015
• Est. Priority Date: 04/11/2014
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: WATANABE, Hiroshi
• Granted Patent: US 10,094,315 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60H 1/0045 mechanical power take-offs from the vehicle propulsion unit
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: B60H 2001/3238 related to the operation of the compressor
• CPC Class Codes: B60H 2001/3266 related to the operation of the vehicle
• CPC Class Codes: B60H 2001/3273 related to the operation of the vehicle, e.g. the compressor driving torque
• CPC Class Codes: F02D 2200/1006 Engine torque losses, e.g. friction or pumping losses or losses caused by external loads of accessories
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 2250/22 by keeping a torque reserve, i.e. with temporarily reduced drive train or engine efficiency
• CPC Class Codes: F02D 29/04 peculiar to engines driving pumps
• CPC Class Codes: F02D 31/003 for idle speed control
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/16 for idling
• CPC Class Codes: F02P 5/1504 with particular means during a transient phase, e.g. acceleration, deceleration, gear change during starting F02P5/1506
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A rotational speed control apparatus for an engine is provided. The engine is configured to drive a compressor for air conditioning. The rotational speed control apparatus includes an electronic control unit. The electronic control unit is configured to: (a) correct a calculated value of the load torque in accordance with a deviation between a rotational speed of the engine and the target rotational speed, as changeover transition period control, in a changeover transition period; and (b) set an execution period of the changeover transition period control such that the execution period in a changeover transition period from the stopped state of the compressor to the driven state of the compressor becomes longer than an execution period of the changeover transition period control in a changeover transition period from the driven state of the compressor to the stopped state of the compressor.

Claims

1. A rotational speed control apparatus for an engine, the engine configured to drive a compressor that compresses a cooling medium for air conditioning, the rotational speed control apparatus comprising:

an electronic control unit that is configured to;

(a) correct a torque of the engine through feedback in accordance with a deviation between a rotational speed of the engine during idle operation and a target rotational speed;

(b) (i) calculate a load torque of the compressor, and (ii) correct the calculated value of the load torque in accordance with a deviation between the rotational speed of the engine and the target rotational speed and correct a required value of the torque of the engine in accordance with the corrected value of the calculated value of the load torque, as changeover transition period control, in a changeover transition period between a driven state of the compressor and a stopped state of the compressor; and

(c) set an execution period of the changeover transition period control such that the execution period in a changeover transition period from the stopped state of the compressor to the driven state of the compressor is longer than an execution period of the changeover transition period control in a changeover transition period from the driven state of the compressor to the stopped state of the compressor.

2. The rotational speed control apparatus according to claim 1, wherein

the electronic control unit is configured to set the execution period of the changeover transition period control in the changeover transition period from the stopped state of the compressor to the driven state of the compressor, such that the execution period in a case where there is a possibility of a liquid pool being formed inside the compressor is longer than the execution period in a case where there is no possibility of a liquid pool being formed inside the compressor.