DE102005046512B4 - Measuring method for the investigation of the heating power of a deicing device on a window of a motor vehicle and corresponding measuring stand - Google Patents

Abstract

Measuring method for the examination of the heating or de-icing performance of a deicing device on a pane (3) of a motor vehicle (2) in a measuring stand (1) comprising the steps:
Introduction of the vehicle (2) to be examined, which has ambient temperature, ambient temperature being understood as a temperature which results from the temperature in the measuring station at the time of the season and which will usually be in the range between 15 ° C and 25 ° C,
- Turning on the engine and the de-icing device of the vehicle (2) for simulating the de-icing of the vehicle and
- Recording of the heat distribution at the disc (3) at intervals by means of an IR sensor (6), in particular a digital IR camera (5), from outside the vehicle (2).

Description

The The invention relates to a measuring method for the Investigation of the heat output of a deicing device on a Disc of a motor vehicle in a measuring stand and a corresponding Measuring stand.

Usually is the de-icing of windows of motor vehicles at low Temperatures (usually z. B. -18 ° C). Around the efficiency and to test or investigate the functions of the deicing device the vehicle in a climatic chamber to the desired low temperature set, so provided with an icy disc. After that will the vehicle introduced into a wind tunnel and the engine started as well as the de-icing device (air conditioning, blower, heating etc.) to simulate the drive of the motor vehicle. Subsequently be at regular intervals Photographs of the examined disc were taken and based on the Degree of deicing, ie the change in the Icing of the disc, the deicing of the disc the heating or De-icing performance of the examined device assessed.

The Setting the required low temperatures and the icing of the discs in the climatic chamber is relatively expensive and time-consuming and expensive. In addition, will be size Quantities of energy needed to the desired Set or reach temperatures. It is also difficult to reproduce the icing reproducibly in consistent quality.

The DE 103 20 364 A1 describes a vehicle defroster designed to detect fogging on a disk with a sensor.

When Sensor is mounted in the interior of the vehicle to the ceiling Infrared (IR) sensor uses the surface temperature of the disc measures, to control the defrosting process.

task the invention it is in contrast, a measurement methods for the Investigation of the heating or de-icing performance of a de-icing device To provide a disc of a motor vehicle in a measuring booth, the in a simple way, the assessment of the defrosting power or heat output allowed.

These The object is achieved by the method according to claim 1 and by the measuring stand Claim 8 solved.

According to the invention is recognized been that that Method for investigating the heating or defrosting performance of a Deicing device can be simplified if not the actual Deicing is observed, as is the case in the prior art is, but the heat distribution in itself, so the cause of the heating or de-icing performance.

Thereby Is it possible, the vehicle even at ambient temperature, ie z. B. 21 ° C to examine. Surprisingly It has been found that the Results of relative heat distribution independent on the vehicle window are from the starting temperature of the vehicle and the measured Heat distribution over the Time at ambient temperature very good with the defrosting process correlated at low temperatures, both qualitatively and also qualitatively

Consequently can without the expense of a climatic chamber z. B. the blower or the heating and therefore the heat distribution be optimized for deicing.

Consequently can be on the elaborate and expensive as well as energy-consuming Step of lowering the temperature to low values (eg -18 ° C) omitted since the measurement takes place at ambient temperature.

From the DE 102 00 486 A1 is an air conditioner in a motor vehicle is known, which is equipped to control the thermal comfort with at least one non-contact temperature sensor. By means of the temperature sensors temperature distributions are measured on different surfaces of the vehicle interior and the air conditioning controlled so that this surface temperature is distributed as evenly as possible. This method is intended for vehicle operation where a temperature distribution in the range of frosty minus degrees, usually -18 ° C up to very high temperatures of 50 ° -60 ° C must be detected. If this method is used for measurement in a measuring stand, the vehicle must have such a temperature distribution. This means a high energy consumption to heat or cool the vehicle accordingly.

In the EP 1 028 604 A2 is a microwave device described in which by means of an infrared sensor, the temperature monitored on the food to be heated and displayed to the user. The temperature range extends from the frozen state to the completely heated state of the food. Again, only the current temperature of the measurement object is detected, which means in a measuring station with respect to a vehicle that the vehicle must have this temperature itself, with the Nach already described above share.

A non-contact measuring method for the qualitative determination of the weather-dependent condition of the road surface is in DE 199 32 094 A1 disclosed. By means of a millimeter wave sensor, the surface moisture of a lit carriageway area is detected. An intense measurement signal indicates a dry road surface, while the absence of a measurable signal indicates the presence of a closed layer of water or ice on the road surface. However, this method does not measure temperature distribution, but provides only a qualitative statement about the surface condition of the road.

This means a significant energy savings, as a vehicle in the Usually ambient temperature, and thus no additional Energy must be used to make the measurement preferable and the vehicle to the test temperature - the here the ambient temperature is - cool. Also the energy consumption in a possibly used wind tunnel becomes considerably reduced, because no energy needed to cool the wind tunnel is.

Further the obtained data or results are better reproducible and This results in a better examination quality, since the empirical factor of the ice layer is omitted. It is very much difficult to produce these constantly and recurrently in constant "quality".

When Ambient temperature is understood to mean a temperature that is different the temperature prevailing at the time of the season in the measuring stand results. Usually this will be a temperature in the range between 15 ° C and 25 ° C. When Temperatures between 18 ° C and 22 ° C have proven particularly suitable. Particularly preferred is a temperature around 21 ° C.

For receiving the heat distribution IR photographs are particularly suitable, the z. B. with a suitable IR camera to be made. Preferably, the shots from outside the Vehicle recorded because the IR camera there z. B. not by the Distributed warm air of a blower disturbed becomes.

Preferably Shielding of the measuring stand against interference radiation also takes place, in particular IR radiation. This allows particularly sensitive and accurate measurements or qualitative high quality IR recordings.

To the Shielding the measuring stand this can be surrounded laterally and above by a shielding surface be, d. H. it is z. B. when using the wind tunnel a passage calmly. It is important that the shielding a preferably assumes homogeneous temperature, this is preferably the temperature of the surrounding air. The shielding surface is preferably from a flat body formed, the body good heat radiation can absorb should. Preference is therefore given to using dark, in particular black, bodies. because they absorb radiation very well. Especially suitable as shielding a curtain, preferably made of textile fabric, in which case the Color should be dark or black.

The gained IR recordings can represented as isotherms, d. H. Areas more similar Temperature are mapped in the same way. This is useful a quantified overview to get the de-icing.

is also the change the distribution or the flow of heat distribution of interest, so can do without the isothermal representation and resorted to the "raw shots" be that with high resolution the areas of different heat played. In addition, it can be the changes in heat distribution make it visible.

Farther can be applied to the vehicle window an optical grid, after a distortion-free representation of the temperature distribution to obtain. This grid can z. B. the form of legally defined Have visible zones and allows thus the quick check, whether within the statutory timeframe, the vehicle window can be de-iced in the visual zones. This grid is preferred by means of self-adhesive metallic film strips on the vehicle window glued.

Further Features, details and advantages of the invention will become apparent the following description of an embodiment with reference to the Drawing. Show it:

1A . 1B schematic views of a measuring stand;

2 the correlation of IR images at ambient temperature with conventional photographs at -18 ° C in isothermal mode and

3 the flow of heat distribution from the IR images at ambient temperature 2 ,

1A and 1B each show a schematic side and front view of a measuring stand 1 for the investigation of the heating or de-icing performance of a built-in air conditioning system Defrosting operation (de-icer) on a pulley 3 a passenger car 2 at ambient temperature.

The measuring stand 1 includes a shield 4 , which are in the form of black fabric webs laterally and above the vehicle suspended or suspended.

The measuring stand further comprises a digital camera 5 with an IR sensor 6 and a related and appropriately configured and programmed computer 7 for controlling the camera as well as recording and evaluating or displaying the digital recordings 9 of the sensor 6 eg on a screen or printout.

In the example shown, the windscreen 3 a commercial car 2 from the camera 5 detected. This is the car 2 in the measuring stand 1 brought and the shielding 4 closed. Here are both the measuring stand 1 as well as the car 2 Ambient temperature, ie are neither cooled nor heated, but showed about 21 ° C.

The shield prevents interference with the IR recordings by interfering rays, such. B. on the disc 3 reflected IR light, and thus allows reproducible results with a high resolution in the range of 0.04 K. In the IR images should reflect the original differences in the temperature distribution of the disc 3 At the beginning of the measurements, it is expedient to be less than or equal to 0.8 K. Then a particularly good quality of the IR recordings is obtained.

After the car 2 in the measuring stand 1 aligned and shielded, is the engine of the car 2 started and the heating, air conditioning and / or an electrically heated vehicle window turned on and put on defrosting. At the same time, when using a wind tunnel, this can be put into operation to possibly simulate the wind during operation of the car. If a curtain is used as a shielding, it must be braced so that no displacement or movement by air currents is possible.

At the same time, at desired intervals with the camera 5 by means of the IR sensor 6 IR images of the heat distribution at the slide 3 recorded and on the computer 7 stored, mapped and possibly evaluated or z. B. printed. Thus, based on the ambient temperature, the change in the heat distribution at the disc can be 3 determine.

The representation of the IR recordings can, for. B. in isothermal representation, as shown in 2 the case is. There, a comparison with the prior art in isothermal representation is shown to obtain a quantitative overview of the heat distribution. The IR images are created with manually adjustable limit temperatures, ie all temperatures below the limit temperature have the same color.

In 2 are usual photo shots on the left side 8th after 9 min. or 15 minutes after the start of de-icing at -18 ° C. On the right side are these usual recordings corresponding IR recordings 9 after starting the de-icer at ambient temperature (21 ° C) faced.

you clearly recognizes the progressing de - icing in the Comparison of the superimposed Recordings. The comparison of the opposite shots different Art shows that the IR shots (right) in virtually all details with the photo shots (left) correlate at -18 ° C, So provide appropriate information about the heat distribution, though they only absorbed at ambient temperature without icing were.

Are more detailed information about the heat distribution and the development desired, such. For example, changing their distribution and spreading the heat, so can the high-resolution raw IR recordings 10 be used as in 3 based on 2 corresponding IR recordings is shown. For better illustration is also a scale 11 for the temperature.

you recognizes that starting from the dark areas (= areas with higher temperature) bleeding up and to the side, in their direction, the heat distribution developed, so the de-icing would proceed. Thus can be z. B. on the blower orientation shut down and optimize these together with the heating power if necessary.

Claims (13)

Measuring method for the examination of the heating and / or de-icing performance of a deicing device on a pane ( 3 ) of a motor vehicle ( 2 ) in a measuring stand ( 1 ) comprising the steps of: - introducing the vehicle to be examined ( 2 ), the ambient temperature, ambient temperature being understood to mean a temperature resulting from the temperature in the measuring station at the time of the year and which will normally be in the range between 15 ° C and 25 ° C, - switching on the engine and the de-icing device of the vehicle ( 2 ) for the simulation of the deicing of the vehicle and - Recording the heat distribution at the disc ( 3 ) at intervals by means of an IR sensor ( 6 ), in particular a digital IR camera ( 5 ), from outside the vehicle ( 2 ). Measuring method according to claim 1, characterized by shielding ( 4 ) of the measuring stand against interference radiation. Measuring method according to claim 2, characterized in that the measuring stand for shielding laterally and above a shielding surface ( 4 ) is surrounded. Measuring method according to claim 2 or 3, characterized in that the shielding with a flat body ( 4 ) is made. Measuring method according to claim 4, characterized in that the body has a curtain ( 4 ), in particular of textile fabric. measurement methods according to claim 2, 3 or 4, characterized in that the shielding surface, the body or the curtain is at least partially black. Measuring method according to one of the preceding claims, characterized in that the recorded IR images ( 9 ) are represented as isotherms. Measuring method according to one of the preceding claims, characterized in that the measuring stand ( 1 ) is arranged in a wind tunnel, which is in operation during the measurement to simulate wind. Measuring method according to one of the preceding claims, characterized in that the disc ( 3 ) by means of an optical grid, in particular produced by self-adhesive metallic film strips. Measuring station for the examination of the heating and / or de-icing performance of a deicing device on a pane ( 3 ) of a motor vehicle ( 2 ), in particular for carrying out the method according to one of the preceding claims, comprising: a vehicle to be examined ( 2 ) and - an IR sensor ( 6 ), in particular a digital IR camera ( 5 ) outside the vehicle ( 2 ) is arranged to receive the heat distribution at the disc ( 3 ) at intervals, wherein both the measuring stand and the vehicle have ambient temperature, wherein ambient temperature is understood to mean a temperature which results from the temperature prevailing in the measuring station during the season and which will usually be in the range between 15 ° C and 25 ° C. Measuring stand according to claim 10, characterized in that a shield ( 4 ) is present against interference. Measuring stand according to claim 11, characterized in that the shield ( 4 ) a flat body, in particular a curtain ( 4 ), preferably of textile fabric. measuring stand according to claim 11 or 12, characterized in that the shield or the flat body at least partially black.