Operating System for a Motor Vehicle Automatic Air-Conditioning System

The invention relates to a control unit for an automatic air-conditioning system for motor vehicles according to patent claim 1.

A control unit for an automatic air-conditioning system for motor vehicles is known, for example from DE 39 146 27. Said control unit contains two rotatable, coaxial control knobs projecting externally from the housing, as well as two coaxial shafts, an inner and an outer shaft, which are rotatably connected with the two control knobs. The temperature and the distribution of air in the interior of the motor vehicle are adjusted by way of said shafts. As another feature, the control unit comprises two indicator drums, which are rotatably connected with the two shafts, arranged in the interior of the control unit, and provided with symbols, which shift in relation to two windows in the front wall of the housing. Furthermore, when adjusted, the two control knobs lock in stable, exactly defined angular positions.

Furthermore, a control unit for an automatic air-conditioning system is known from U.S. Pat. No. 5, 220,805, where the usual parameters of an air-conditioning system such as, for example "air distribution", "air volume" and "air temperature" are adjusted via infinitely rotatable control knobs. With this control unit, the set point positions in the manual mode are indicated by digitally controlled symbols. When the control knob is turned, trailing of the digital symbols is accomplished by means of computer control, which determines the change in the desired parameter of the air-conditioning system from the original position, the sense of rotation, and the extent of rotation. When the parameter of the air-conditioning system is changed by manually overriding the automatic control by turning the knob, it is perceived as disadvantageous--due to the computer control--that the change takes place only in discrete, digitizable steps. Simple and safe adjustment of the desired parameter is prevented due to coarse digitization.

With other known designs of air-conditioning systems, it is possible, for example to override the automatic control by hand by manually actuating a great number of pushbuttons, or by actuating rocker keys a number of times for adjusting the speed of the blower and thus the value for air volume. The values so set by hand in the override function are indicated via LCD-displays. Provision is made for similar displays for indicating the actual value selected by the automatic system when operating in the purely automatic mode.

According to the problem of the present invention, the objective is to design possibilities for setting and recognizing manually adjustable values for "air distribution", "air volume" and, if necessary, "air temperature" in a simpler and safer way.

According to the invention, the solution to said problem is implemented by a control unit with the features of claim 1. Advantageous developments of the invention are the objects of the dependent claims.

In the embodiment of the control unit according to the invention, which has modes for both automatic and manual adjustment, provision is made for manually adjustable analog setting devices to regulate "air distribution" and/or "air volume" and/or "air temperature", permitting simple manual handling of such adjustments. As indicators of "air distribution" and/or "air volume" each analog setting device is associated with an analog display which in the manual setting mode acts as a direct analog indicator of the nominal value, activated by an independent outside drive, consistent with the preset nominal value, thereby affording quick and dependable read-out of the preset value. When switching to the automatic mode by actuating an "Automatic" pushbutton, such independent separate drive causes the indicator device to directly slave the given actual value of "air distribution" and/or "air volume" analogously, serving as an indicator for the actual value. In this way, the indicator previously used in the manual mode as a nominal value display can be concomitantly used in the automatic mode as an indication of the actual value.

To achieve simple and safe adjustments and read-outs, on the one hand, and a compact design of the device setting the nominal value, on the other, provision is usefully made in each case for a control knob surrounded concentrically over at least a portion of its circumference by a scale dial for the indicators of nominal or actual values. According to a preferred development of the invention, provision is made for slave indicators of nominal-value and actual-value of "air distribution" and/or "air volume", with the help of a separate drive, whereas a slave indication is omitted for the temperature setting controls. In a particularly compact embodiment, provision is made as a temperature-setting means for a ring concentric with the control knob for "air distribution" and/or "air volume" preferably at least with a control knob for "air distribution" particularly in the form of an outer ring having a stationary, annular dial scale associated with it.

The invention and other advantageous developments of the invention according to the features of dependent claims are explained in greater detail in the following exemplified embodiments shown schematically in the drawing in which:

FIG. 1 shows a view of the face plate of a first embodiment of a control unit according to the invention;

FIG. 2 shows a cutout of the top view of the control unit according to FIG. 1;

FIG. 3 shows the face plate of a second embodiment of a control unit according to the invention;

FIG. 4 shows a cutout of the top view of the control unit according to FIG. 3;

FIG. 5 shows a first cutout of the top view of the control unit according to FIGS. 1, 2, with an LED-display for adjusting the "air volume"; and

FIG. 6 shows a second cutout of the top view of the control unit according to FIGS. 1, 2, with an LCD-checker board display for adjusting the "air volume".

FIG. 1 shows a top view of the face plate of a control unit of an automatic air-conditioning system for motor vehicles, with manual adjusting means in override function for overriding the automatic mode in the form of a center control knob 2 for adjusting the "air volume" by changing the speed of the blower; with a left control knob 3 and a right control knob 3 for "air distribution" to the left and, respectively, to the right half of the vehicle; as well as a rotary ring 4 for adjusting the "air temperature". As the nominal value indicator in the manual adjustment mode, and the actual-value indicator mode in the automatic mode, provision is made according to FIG. 1 for the indicator 2.1 slaved by a separate drive, for control knob 2 setting "air volume", and the indicator 3.1 for control knob 3 regulating "air distribution", whereby indicators 2.1 and 3.1 are guided along the fixed indicator dials 2.2 and 3.2, respectively, arranged, for example as transparent displays in front of the indicator dials. A suitably controlled stepping motor drive is advantageously used for independently driving the indicators, which are slaving without mechanical connection to the control knobs, especially for fully rotatable adjustment and indication range over 360.degree.. In lieu of a stepping motor, provision can be made, for example for a rotary coil instrument, for a particularly economical design

The automatic function of the air-conditioning system is dependent in terms of switch-off upon manual actuation of the nominal-value adjusting means in the form of control knobs 2 and 3 for "air volume" by changing the speed of the blower of the air fan, and, respectively, for "air distribution". Following prior manual actuation of the nominal-value adjusting means in the form of control knobs 2 and 3, the automatic mode can be switched on again at any time by actuating an automatic switch-on means particularly in the form of a pushbutton 5. The latter can be arranged either as a separate component in the front panel of control unit 1 as shown in FIG. 1, or can be integrated with at least one of control knobs 2 and 3 to obtain a particularly high degree of compactness, such integration being accomplished by arranging it radially inside control knob 3 for "air distribution" so as to be axially movable.

In automatic mode, the given actual value is displayed by the indicator in accordance with the automatic setting. Now, if the device for manual adjustment, in particular in the form of control knobs 2 and 3 is turned in either direction, the automatic system is switched off by the control unit with respect to the corresponding function of the control knob and the unit immediately takes over the last value as the initial manual setting. Starting from such value, the indicators follow in advantageous local correlation to their adjusting means partially without noticeable time lag in the form of a nominal value indicator. If, by actuating the automatic switch-on particularly in the form of pushbutton 5, the mode is reversed back to automatic, the respective values are controlled by the automatic system according to its preset program. The indicators move to new values specific to the automatic system and indicate the value controlled by the automatic system, as an actual value display.

As particularly shown in FIGS. 2 and 4, the setting and displaying means arranged concentrically to the same axis or shaft are at least partly designed with different axial planes of actuation, in such a way that they can be easily identified and handled when gripped for manual actuation.

Instead of the mechanical indicators 2.1 and 3.1 for "air volume" and "air distribution" according to FIG. 1, provision is made according to special refinements of the invention illustrated in FIG. 4 for indicators in the form of light-emitting diodes 2.3 and LCD-fields 2.4, which are switched on or activated depending on the indicator position, such diodes and fields being adjustable corresponding to the given nominal and/or actual values.

As a means for adjusting the temperature, provision is made in each case for a rotary ring 4 for "air temperature", which is rotatably arranged concentrically with control knob 3, and which has an indicator 4.1, the latter being adjustable relative to a stationary temperature scale ring 4.2.