APPARATUS FOR CONTROLLING ENGINE WARMING-UP

• US 20130144515A1
• Filed: 11/29/2012
• Published: 06/06/2013
• Est. Priority Date: 12/01/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: OKAMOTO, Tsuyoshi, TASHIRO, Tsutomu
• Granted Patent: US 9,151,242 B2
• Time in Patent Office: Days
• US Class Current: 701/113
• CPC Class Codes: F02D 2200/503 Battery correction, i.e. corrections as a function of the state of the battery, its output or its type
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 41/068 for warming-up
• CPC Class Codes: F02D 45/00 Electrical control not provided for in groups F02D41/00 - F02D43/00

Abstract

A vehicle has an engine as a driving source. The vehicle has a charge system which generates electric power by using a part of rotational output of an engine, and charges a battery by the generated electric power. Optimal shaft efficiency points are combinations of revolution speed and torque of the engine for maximizing the shaft efficiency. Optimal shaft efficiency line passes through the optimal shaft efficiency points for each engine output level. Warming-up operation line is defined by shifting the optimal shaft output efficiency line to a side to increase heat loss. An engine controller stores the lines. The engine controller performs a warming-up operation by operating the engine at a revolution speed and a torque on the warming-up operation line. The engine controller controls the battery to reduce possibilities of a full charge at a next warming-up.

Claims

1. An apparatus for controlling engine warming-up for a vehicle having a charge system which generates electric power by using rotational output of an engine for a driving source of the vehicle and charges a battery by the generated electric power, the apparatus comprising:

a storing section which stores a warming-up operation line which is defined by shifting an optimal shaft output efficiency line to a side to increase heat loss, the optimal shaft efficiency line being determined to pass through optimal shaft efficiency points for each engine output level, the optimal shaft efficiency points being combinations of revolution speed and torque of the engine for maximizing the shaft efficiency which is a rate of the rotational output of the engine to a fuel consumption; and

a performing section which performs a warming-up operation by operating the engine at a revolution speed and a torque on the warming-up operation line.

2. The apparatus in claim 1, wherein

the storing section further stores an optimal balance line which shows an optimal balance between a temperature of the engine or a coolant and a residual charge of the battery for performing the warming-up operation, and wherein

the performing section determines a shaft efficiency priority degree, which is a degree for giving priority to an improvement of the shaft efficiency more than an increase of the temperature, based on the temperature of the engine or the coolant at the present time, the residual charge at the present time, and the optimal balance line, and wherein

the performing section variably sets a shifting amount of the warming-up operation line to the optimal shaft efficiency line according to the determined shaft efficiency priority degree.

3. The apparatus in claim 1, wherein

the performing section sets the shifting amount of the warming-up operation line to the optimal shaft efficiency line small as the engine output becomes low.

4. The apparatus in claim 1, wherein

the performing section increases the engine output so that the engine output does not exceed a limit value, when a charging current flowing to the battery is limited to the limit value due to a low temperature of the battery.

5. The apparatus in claim 1, wherein

the performing section increases power consumption of an electric heater on the vehicle when the residual charge is equal to or higher than a predetermined value.

6. The apparatus in claim 1, wherein

the performing section transfers electric power from the battery to another battery when the residual charge is equal to or higher than a predetermined value.

7. The apparatus in claim 1, wherein

the apparatus is applied to a hybrid vehicle which has the charge system which controls the battery so that the residual charge is maintained less than an upper limit during the operation of the hybrid vehicle, and further comprising

an upper limit setting section which sets the upper limit to a lower level when it is estimated that a warming-up is necessary at the next engine start relative to that when it is estimated that a warming-up is not necessary at the next engine start.

8. The apparatus in claim 1, wherein

the apparatus is applied to a plug-in vehicle which has the charge system being capable of charging the battery from an external power source so that the residual charge is maintained less than an upper limit when the vehicle is not operated, and further comprising

an upper limit setting section which sets the upper limit to a lower level when it is estimated that a warming-up is necessary at the next engine start relative to that when it is estimated that a warming-up is not necessary at the next engine start.