AU622798B2 - Air conditioner control unit - Google Patents

Description

622798 FormOLS COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION (OH IGiNAL) Class Application Number: Lodged: Int. Class Complete Specification Lodged: oPriority: Sl .Related Art: *0 •06 .e S Accepted: Published: o••Name of Applicant PERT'EX[ INVESTENS PTY LTD trading as KALINA AIRE Address of Applicant: 1A LOUISE AVENUE INGLEBURN NSW 2656 oo. S Actual Inventor: JAMES WILLIAM BRENNAN and NEIL KENNY Address for Service: WATERMARK PATENT TRADEMARK ATTORNEYS SUITE 6, FLOOR 16, TOWN HALL HOUSE, 456 KENT STREET, SYDNEY, NSW, 2000 AUSTRALIA.

Complete Specification for the invention entitled: AIR CONDITIONER CONTROL UNIT The following statement is a full description of this invention, including the best method of performing it known to SI 4E'74 1j 7 05 'it I 2 TECHNICAL FIELD This invention relates to air conditioning and more particularly to a control unit for a vehicle air conditioner.

BACKGROUND ART Vehicle air conditioners are often specifically designed for cooling the operator cabins of such as heavy road and off-road vehicles, cranes, rollers, loaders, graders, fork lifts, crawler tractors and the like. Such air conditioners are generally roof-mounted and include condenser and cooling fan assemblies, evaporator-heater coil and blower assembly, receiver-drier, air handling chamber etc., contained within a steel case. A thermostatically-controlled clutch, mounted on the compressor, controls compressor operation. The compressor/clutch unit is mounted as a separate assembly with belt and pulley on a mounting bracket specifically designed for each particular engine arrangement.

0° Existing manual air conditioner control mechanisms require the operator to be continually adjusting both fan speed Got 0 and heat/cool cycles. As the operator is thus always responding to 'uncomfortable' conditions, efficiency suffers, adjustments are frequently necessary and cabin climate o.0* conditions are never optimised.

DISCLOSURE OF INVENTION 0S0O It is therefore an object of the present invention to overcome the above and other disadvantages by the provision of an electronic control unit for a vehicle air conditioner of the kind defined above; the said electronic control unit being comprised of a microprocessor-controlled unit including means to sense climatic conditions within a vehicle's cabin, and 0 means to automatically adjust fan speed and evaporator coil

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ouput to thereby precisely control the said climatic conditions.

Preferably the control unit's means to sense climatic conditions comprises a software system able to sense the differential between actual and desired cabin temperatures and the said means to automatically adjust fan speed and 3 evaporator coil output is constituted by the software system which includes a multi-band, heat/cool cycle arrangement and which is able to monitor temperature and select appropriate fan speed and cyle to thereby maintain, constantly and accurately, the desired cabin temperature.

Ideally, the electronic control unit may be accommodated within a housing which is mountable in the vehicle's cabin and in which the microprocessor-controlled is contained. The housing has a face consisting in an embossed fingertip touchpad adapted to seal and protect the internal electronic componentry, the touchpad including, at least, an on/off keypad, a cabin temperature-checking keypad, a pair of scrolling keypads, and a LED display panel adapted to display c. cabin temperature and over which the display is able to scroll oupon operation of either one of the scrolling keypads.

geee: The microprocessor-controlled software may be adapted to operate in conjunction with two off-coil sensors which can monitor the output performance of the air-conditioner ooo evaporator coil tcgether with the cycled air temperature, and to monitor the heat cycle output; whereby, respectively, the evaporator coil is able to be protected from icing damage at low cool cycle input levels, and whereby over-run and peak level condensation build-up is prevented by disengaging the se solenoid valve.

BRIEF DESCRIPTION OF DRAWINGS 9 In order that the reader may gain a better understanding of the present invention, hereinafter is described one or more preferred embodiments thereof, by way of se example only and with reference to the accompanying drawings in which:o Figure 1 is a front view of an electronic control unit according to the present invention; Figure 2 is a corresponding side view; and Figure 3 is a front view of an inventive control unit in vertical format.

Throughout the drawings, like integers are i 4 referenced by the same numeral.

BEST MODE FOR CARRYING OUT THE INVENTION The control unit, generally referenced i, is comprised of a housing 2, ideally injection-moulded from impact-resistant, engineering grade thermoplastic material, in which the electronic componentry is accommodated. Housing 2, while it may form an integral part of a roof-mounted vehicle air conditioner, it is ideally suited to function as a "remote" controller; that is to say, it can be located conveniently in a preferred position in a vehicle cabin.

The face of housing 2 consists in a embossed polycarbonate fingertip touchpad 3 which seals and protects the internal electronic components. Touchpad 3 includes tactile embossed keypads 4, 5, 6 and 7 hereinafter to be more fully described with LED indication for each one, referenced S. respectively 8, 9, 10 and 11. Touchpad 3 also includes an LED display panel 12.

*Keypad 4 is an on/off control which activates the unit. When it is pressed the digital display at LED panel 12 will display the actual cabin temperature. The unit then acts to control air conditioner output so as to rapidly reach and maintain the desired cabin temperature or "set point".

Keypad 5 has for its purpose the checking of the level of the set point temperature that is to say, the said desired cabin temperature. It may be used to quickly check the r differential between the desired cabin temperature and the actual cabin temperature. When keypad 5 is pressed, the display will show desired temperature; this set point temperature is stored in the microprocessor memory and will remain unaffected by machine shutdown. If no additional keypads are pressed the set point temperature will remain displayed for a period of, say, five seconds before reverting to actual cabin temperature.

Keypads 6 and 7 may aptly be termed, respectively, "down" and "up" controls as indicated by the arrows 13 and 14.

These controls are used to alter the set point conditions.

-0 M M 0000 *go *o 0 *.:00 0 o 0000..

0 00 0 000 00 00 0 000 0 000 0 *000 000 00 00 0 Keypad 5 is pressed firstly and then either keypad 6 or keypad 7 pressed to change set point temperature. The display will "scroll" through slowly by 0.5 0 C increments.

In LED display panel 12 is shown cabin temperature conditions in 0.5 0 C increments. Display temperature range is in the order of -7 0 C to 57 0 C, normal display shows actual cabin temperature.

The mode of operation is as follows:- pressing keypad 5 the operator "sets" the desired cabin temperature on the digital display panel. As stated previously, this set point temperature is stored in the software memory of the unit and will not be affected by machine shutdown. With the set point established, the operator needs only to engage the unit by pressing keypad 4. However, if required, it is possible to manually override the set point temperature to select a lower or higher temperature.

Immediately the unit is engaged, the differential between the actual cabin temperature and the desired cabin temperature the set point is sensed by the software within the housing. The unit is then programmed to select the appropriate fan speed and cy:le to quickly, automatically and accurately reach and maintain the desired cabin temperature.

No further control adjustment is necessary. The digital display enables the operator to monitor actual cabin temperature at all times and to check set point level.

The differential between the actual cabin temperature and the desired cabin temperature "set point") is sensed by the advanced system software of the unit.

The unit then steps up or down in this embodiment through its five-band heat/cool cycle to quickly optimise the cabin temperature and maintain it accurately. The software monitors temperature and selects the appropriate fan speed and cycle to maintain constantly and accurately the desired cabin temperature.

Turning now to Figure 3 of the drawings, there is to be seen an electronic control unit according to the present r invention, in what may be considered a "vertical format".

In this embodiment, the control unit, again generally referenced 1, has a housing 2, ideally injection-moulded from impact-resistant, engineering grade thermoplastic material, inside which the electronic componentry, or circuitry, is accommodated.

The face of housing 2 consists in a fingertip touchpad 3 which seals and protects the internal electronic components and circuits. Touchpad 3 includes, inter alia, tactile keypads 4, 5, 6 and 7 to be more fully described hereinafter with integral LED indicators for each one, these indicators being referenced 8, 9, 10 and 11 respectively, and r an LED display panel 12.

As with the horizontal-format embodiment shown in Figures 1 and 2, keypad 4 is the on/off control; keypad 5 is ooooo O the set point temperature key; while keypads 6 and 7 are, respectively, the "up" and "down" scrolling controls as indicated by the arrows 14 and 13. The mode of operation of the electronic control unit of Figure 3 is exactly the same as that of the first embodiment; manipulation of the four keypads 4, 5, 6 and 7 is facilitated by their "large field" format.

:oAlso incorporated in touchpad 3 is an array 15 of circuit fault LED indicators, in this instance eleven in number, which indicate faults in the eleven electronic circuits accommodated within housing 2.

The vertical format, or orientation, of the electronic control unit shown in Figure 3 allows the lower wall 16 to be provided with an exit aperture 17 for the cable 18.

Thus, the vertical format control unit is particularly suited to function as a "remote" controller for, say, a roof-mounted vehicle air conditioner, the unit being able to be located conveniently with the operator's reach perhaps on an instrument panel or cabin wall.

INDUSTRIAL APPLICABILITY The inventive control unit is able to cope thus with the most severe environmental conditions and to eliminate I j 7 the problems caused by operator abuse in the field. Serious malfunctions often occur when air conditioners are left unattended and operating at maximum levels in open or closed cabins. In the present invention, the microprocessor-controlled software program operates in conjunction with two remote off-coil sensors which monitor the output performance of the air conditioner's evaporator coil together with the cycled air temperature at all times. In this manriner, the evaporator coil can be protected from icing damage at low output levels on the cool cycle. In similar manner, output is monitored on the heat cycle, preventing over-run and the build up of condensation at peak levels by disengaging the OQ ~solenoid valve. As such the program balances the performance See.

ro of the air conditioner and improves its efficiency, while protecting the electronic componentry from damage. These oIOOQ maximum and minimum operating conditions may be set accurately in the factory.

NMaintenance, installation and service difficulties are minimised and air conditioning units fitted with the inventive electronic control units can be left unattended for long periods of time without the risk of damage.

From the abovegoing, it will be appreciated by 5505 o*o° those skilled in the art that numerous variations and modifications may be made to the invention without departing S from the spirit and scope thereof, as set out in the following claims.

SSo eooee

Claims (3)

1. 2. The electronic control unit as claimed in Claim I, wherein said means to sense climatic conditions comprises a Soso c ~software system able to sense the differential between actual and desired cabin temperatures and said means to automatically adjust fan speed and evaporator coil output is constituted by the said software system which includes a multi-band heat/cool a. cycle and which is able to monitor temperature and select appropriate fan speed and cycle to thereby maintain, constantly and accurately, thedesired cabin temperature.
2. 3. The electronic control unit as claimed in Claim 1 or Claim 2, wherein the said unit is accommodated within a housing mountable in said vehicle's cabin and in which said microprocessor-controlled unit is contained; the said housing having a face consisting in an embossed fingertip touchpad adapted to seal and protect internal electronic componentry, said touchpad including, at least, an on/off keypad, a cabin temperature-checking keypad, a pair of scrolling keypads, and a "LED display panel adapted to display cabin temperature and over which said display is able to scroll upon operation of either Sone of said scrolling keypads.
3. 4. The electronic control unit as claimed in Claim 1 or Claim 2, wherein said microprocessor-controlled unit is adapted to operate in conjunction with two off-coil sensors which are able to monitor output performance of said cAI A 9 air-conditioner evaporator coil together with cycled air temperature in the vehicle's cabin, and to monitor heat cycle output; whereby, respectively, said evaporator coil is able to be protected from icing damage at low cool cycle input levels, and whereby over-run and peak level condensation build-up is prevented by disengagement of an associated solenoid valve. DATED this 17th day of May, 1990. PERTEX INVESTMENTS PTY. LTD. trading as KALINA AIRE WATERMARK PATENT TRADEMARK ATTORNEYS SUITE 6, FLOOR 16, TOWN HALL HOUSE, 456 KENT STREET, SYDNEY, NSW, 2000. *O S S 0 I B ft I