Ventilation – Vehicle – Having automatic control means
Reexamination Certificate
1999-09-01
2001-05-01
Joyce, Harold (Department: 3744)
Ventilation
Vehicle
Having automatic control means
C237S01230R
Reexamination Certificate
active
06224478
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to climate control systems and in particular, but not exclusively, to a climate control system which is suitable for use in a vehicle.
BACKGROUND OF THE INVENTION
The objective of a climate control system is to provide a comfortable environment to a vehicle occupant, whilst being relatively unobtrusive and avoiding sudden and/or severe changes which may distract the vehicle occupant, along with providing efficient usage of the climate control system equipment.
It will be appreciated that increasingly more sophisticated climate control systems are being incorporated within vehicles, in order to provide comfort and convenience for their users. It is necessary, however, to appropriately direct airflows from such a climate control system in order to maximise performance. It may, for example, prove desirable to defrost/demist window surfaces within the vehicle prior to heating/cooling of the cabin and, in such circumstances, it would be necessary to direct the air flows towards those surfaces.
Major changes between air flow directions may appear to be relatively unpleasant to a user, particularly if the air flow is heated or cooled, e.g. foot level to face level changes.
A sophisticated climate control system could, as depicted in
FIG. 1
, continuously calculate a control quotient Z in order to set a distribution F of a flap means between a foot level, a bi-level and a face level in order to direct the flow most appropriately.
As can be appreciated from
FIG. 1
, however, use of a substantially linear relationship for the control quotient Z means you need sophisticated feedback arrangements to provide substantially absolute positional control of flap drive mechanisms, e.g. using servo motors, in order to provide satisfactory bi-level control.
It will be appreciated that calculation of such a control quotient Z for absolute positional determination often includes consideration of a range of environmental factors, such as internal temperature, external temperature, desired temperature, solar load and air flow speed. Thus, a relatively complicated relationship may have to be used in order to continuously derive the control quotient Z and thus adjust, through servo motor control across substantially the whole range, an absolute bi-level position for air flow direction and orientation F. Such sophistication within the climate control system can be expensive and cumbersome.
It will also be appreciated that, typically, environmental conditions within vehicles will not change very rapidly. Thus, the calculation of the control quotient Z will precipitate relatively marginal differentials between actual successive determinations of the value of Z. In previous systems, such as the one as described above with regard to
FIG. 1
, these marginal changes in the control quotient Z precipitate a reciprocally marginal change in the bi-level position, determined through accurate servo motor control of the air direction flap. Thus, the motor and direction flap are repeatedly altered for only marginal differences in performance.
One example of a quite sophisticated climate control system is disclosed in U.S. Pat. No. 5,156,204 and it is used to provide an appropriate temperature distribution between ventilation used for users and that used for defrosting.
Instead of the absolute determination of a bi-level position F on a linear slope between face level and foot level, a cheaper system might use exclusive orientations and a possible such arrangement is depicted in FIG.
2
. In this manner, the climate control system still has a face level, a foot level and a bi-level position but uses a less cumbersome control relationship to derive its control quotient Z. In this case, the control quotient Z is approximated to the nearest exclusive orientation, i.e. foot, face or bi-level.
Although complicated methods of controlling the setting of the flaps are no longer necessary, there is a price to pay in terms of user comfort/convenience. With such cheaper systems there is a noticeable transition between respective foot level, bi-level and face level orientations. This can be particularly uncomfortable for a user when the airflow from the vents is significantly cooler or hotter than the air presently around him. For example, in a simpler system of the type shown in
FIG. 2
, upon determination of a value for the control quotient Z, a relatively minor change in value may lead to a massive step between the foot level and bilevel, followed by the bi-level to face level and vice-versa.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved climate control system which is suitable for use in a vehicle.
In accordance with the present invention, there is provided a climate control system for a vehicle, the system including an air flow direction means arranged in use to operate according to a control quotient so as to resent an air flow in a range of orientations substantially towards an occupant of said vehicle, a said presentation in a said orientation being dependent upon a plurality of environmental factors which are consolidated into said control quotient, said system being characterised in that said range of orientations are arranged in groups which include at least one base orientation group having a plurality of base orientation levels and at least one intermediate orientation group which comprises one or more intermediate orientation levels between two neighbouring said base orientation levels, and in that said air flow direction means is arranged to pass, if moving between said neighbouring base orientation levels, at least transiently through the or each said intermediate orientation level, whereby a variation in said presentation of said air flow between said neighbouring base orientations appears to a user to be more gradual than would be a substantially stepped change if made directly therebetween.
The air flow direction means may be arranged, while moving between said orientation levels, to dwell at a said orientation level for a predetermined time period. A said predetermined time period spent dwelling at one or more of said base orientation levels may longer than a said time period spent dwelling at one or more said intermediate orientation levels.
Said system may include a rapid start mode of operation in which the number of said base and/or intermediate orientation levels used is reduced.
Said system may further comprise an absolute position placing means arranged in use to place said air flow direction means in substantially absolute operational positions in the region of at least said base orientation levels.
Said system may further comprise a nudging means arranged in use to substantially nudge, push or move said air flow direction means into the or each said intermediate orientation levels between said base orientation levels.
Said environmental factors may include one or more of an interior temperature, an exterior temperature, a solar load, an air flow speed, a desired temperature and vehicle occupancy.
Typically, the control relationship will be:
Z=T
set.
K
1
−
Tn.K
2
−
Tx.K
3
−
Sol.K
4
−
K
5
where:
Tset=set temperature
Tn=in car temperature
Tx=exterior temperature
Sol=solar load; and
K
1
-
5
are tuning coefficients set for a particular climate control installation within a vehicle.
At least one said base orientation group may include at least three base orientation levels. At least one said intermediate orientation group may include at least two intermediate orientation levels. Said range of orientations may include a face level orientation and a foot level orientation.
The invention also provides a vehicle including a climate control system according to the invention.
REFERENCES:
patent: 5156204 (1992-10-01), Doi
patent: 5186387 (1993-02-01), Doi et al.
patent: 0 031 518 A1 (1980-12-01), None
patent: 0031518 A1 (1981-07-01), None
patent: 2 297 155 (1996-07-01), None
Boles Derek S.
Davis and Bujold
Joyce Harold
Rover Group Limited
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