Fan control system and method for simultaneous heat transfer application and engine enclosure ventilation

• US 6,435,144 B1
• Filed: 06/30/2000
• Issued: 08/20/2002
• Est. Priority Date: 11/02/1999
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Luster, Gary L, Dicke, Paul A
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): Harris, Katrina B.
• Application Number:
  US09/609,084
• Time in Patent Office: 781 Days
• Field of Search: 123/41.66, 123/41.12, 123/41.65, 165/41, 165/51, 180/68.4, 180/68.1, 623/231
• US Class Current: 123/41.12
• CPC Class Codes: B60H 1/00735 Control systems or circuits characterised by their input, i.e. by the detection, measurement or calculation of particular conditions, e.g. signal treatment, dynamic models
• CPC Class Codes: B60H 1/00814 Control systems or circuits characterised by their output, for controlling particular components of the heating, cooling or ventilating installation
• CPC Class Codes: B60H 1/3204 using compression B60H1/3233 takes precedence
• CPC Class Codes: B60K 11/06 with air cooling
• CPC Class Codes: F01P 11/10 Guiding or ducting cooling-air, to, or from, liquid-to-air heat exchangers
• CPC Class Codes: F01P 2001/005 Cooling engine rooms
• CPC Class Codes: F01P 5/02 Pumping cooling-air; Arrangements of cooling-air pumps, e.g. fans or blowers

Abstract

A system for both providing air flow through a condenser core of an air conditioner and ventilating an engine compartment in a work machine. A control system for controlling the air flow through the condenser core and through the engine compartment includes a signal generating mechanism associated with the air conditioner operable to output a signal to the control system indicative of a desired fan speed, at least one sensor positioned in the engine compartment for determining the air temperature therein, and a controller coupled to the signal generating mechanism and to the at least one sensor for outputting a signal to the fan to control the speed thereof, the output signal being indicative of the highest fan speed dictated by the signals received from the signal generating mechanism and from the at least one sensor.

Claims

1. A system for controlling air flow through a a refrigerant condenser core for an air conditioner and ventilating an engine compartment in a work machine comprising:

a fan positioned adjacent one end portion of the engine compartment downstream from the condenser core;

signal generating means associated with the air conditioner, the signal generating means being operable to output a signal indicative of a desired fan speed based upon operation of the air conditioner;

at least one sensor positioned in the engine compartment for determining the air temperature thereof;

an electronic controller coupled with the signal generating means and with the at least one sensor for receiving signals therefrom, the controller being operable to receive a signal from the signal generating means indicative of a desired fan speed for operation of the air conditioner, and a signal from the at least one sensor indicative of the temperature of the engine compartment;

the controller being further operable to determine a desired fan speed for ventilating the engine compartment based upon the signal received from the at least one sensor indicative of the temperature within the engine compartment; and

the controller outputting a signal to the fan to control the speed thereof, the output signal being indicative of the highest fan speed dictated by the signals received from the signal generating means and from the at least one sensor.

2. The control system as set forth in claim 1, wherein the at least one sensor positioned in the engine compartment is positioned proximate to the hottest area associated with the engine compartment.

3. The control system as set forth in claim 1, wherein the engine compartment includes at least one functional component positioned downstream from the fan, the at least one sensor being positioned proximate to the at least one functional component.

4. The control system as set forth in claim 1, wherein the fan is operable between a zero speed and a predetermined maximum speed, the controller determining the desired fan speed for ventilating the engine compartment to be zero if the temperature sensed by the at least one sensor is below a predetermined minimum temperature.

5. The control system as set forth in claim 1, wherein the fan is operable between a zero speed and a predetermined maximum speed, the controller determining the desired fan speed for ventilating the engine compartment to be the maximum fan speed if the temperature sensed by the at least one sensor is above a predetermined maximum temperature.

6. The control system as set forth in claim 1, wherein the fan is operable between a zero speed and a predetermined maximum speed, the controller determining the desired fan speed for ventilating the engine compartment to be proportionately between zero and the maximum fan speed if the temperature sensed by the at least one sensor is between a predetermined minimum and maximum temperature.

7. The control system as set forth in claim 1, wherein the work machine includes an engine and an ignition switch, the ignition switch being operable between at least an on position wherein the engine is allowed to operate and an off position wherein the engine is shutdown, the controller being operable to allow the fan to continue to operate at the last determined desired fan speed if the temperature sensed by the at least one sensor is above a first predetermined temperature, the fan being allowed to continue to operate until the temperature sensed by the at least one temperature sensor falls below a second predetermined temperature.

8. The control system as set forth in claim 1, wherein the control system includes a plurality of sensors positioned at different locations within the engine compartment, the controller being operable to receive a signal from each of the plurality of sensors indicative of the temperature in the engine compartment proximate to the corresponding sensor;

and

the controller being further operable to determine a fan speed for ventilating the engine compartment based upon the signal received from the sensor indicative of the hottest temperature within the engine compartment.

9. A method for controlling the speed of a fan in a work machine, the work machine including an air conditioner and an engine compartment, the fan being positioned between a condenser core of the air conditioner and one end portion of the engine compartment, the method comprising the steps of:

sensing an air temperature in the engine compartment of the work machine;

determining a fan speed based upon the temperature sensed in the engine compartment;

sensing the operation of the air conditioner;

determining a fan speed based upon the operation of the air conditioner;

comparing the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment with the fan speed determined in the step of determining a fan speed based upon the operation of the air conditioner; and

setting the speed of the fan to the higher of the fan speeds determined by said comparison.

10. The method as set forth in claim 9, wherein the fan is operable between a zero speed and a predetermined maximum speed, the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment being determined in accordance with the following criteria:

if the temperature sensed in the step of sensing a temperature in the engine compartment of the work machine is below a predetermined minimum temperature, the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment will be zero;

if the temperature sensed in the step of sensing a temperature in the engine compartment of the work machine is above a predetermined maximum temperature, the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment will be the maximum fan speed; and

if the temperature sensed in the step of sensing a temperature in the engine compartment of the work machine is between the predetermined minimum and maximum temperatures, the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment will be a speed proportionately between zero and the maximum fan speed.

11. The method as set forth in claim 9, wherein the temperature sensed in the step of sensing a temperature in the engine compartment of the work machine step is proximate to the hottest area associated with the engine compartment.

12. The method as set forth in claim 9, wherein the engine compartment includes at least one functional component positioned downstream from the fan, the temperature sensed in the step of sensing a temperature in the engine compartment of the work machine step being proximate to the at least one functional component.

13. The method as set forth in claim 9, wherein a plurality of temperatures are sensed temperature sensed in the step of sensing a temperature in the engine compartment of the work machine at different locations within the engine compartment, and wherein the fan speed determined in the step of determining a fan speed based upon the temperature sensed in the engine compartment is based upon the hottest temperature sensed within the engine compartment.