DE102009012259B4 - Method for testing a motor vehicle for its corrosion resistance - Google Patents

Abstract

A method for testing a motor vehicle for its corrosion resistance, wherein the motor vehicle is exposed in a climate chamber environmental and weather conditions, characterized in that the motor vehicle is subjected to the following method steps: a. Passage through a basin filled with saline solution and drizzle, b. exposure to salt solution and sprayed liquid for several hours during a test run on a test track, c. Shut down in a climatic chamber, with decreasing relative humidity, the temperature is kept constant and then the temperature and the relative humidity can be controlled increased.

Description

The invention relates to a method for testing a motor vehicle for its corrosion resistance, wherein the motor vehicle is exposed in a climate chamber environmental and weather conditions.

Such a generic method is for example from the US 2003/0046048 A1 known. Other corrosion studies in which objects are exposed to saline liquids and are located in rooms, are from the US 4794 804 A , of the DE 103 31 474 A1 and the DE 100 10 250 A1 known. In addition, it is from the JP 57 020 643 A It is known that the motor vehicle drives on a saltwater-covered road section.

It has proved to be disadvantageous in all known methods that it is difficult to create the same, repeatable and realistic conditions for the test method.

The object of the present invention is to specify a method with which a vehicle can be tested in a sustainable and realistic manner for its corrosion resistance.

• a. Durchfahrt durch ein Becken, gefüllt mit Salzlösung, und Sprühregen,
• b. mehrstündiges Einwirken von Salzlösung und aufgesprühter Flüssigkeit während eines Testlaufes auf einer Teststrecke,
• c. Abstellen in einer Klimakammer, wobei bei abnehmender relativer Feuchte die Temperatur konstant gehalten wird und anschließend die Temperatur und die relative Feuchte erhöht werden.

The invention proposes a method for testing a motor vehicle for its corrosion resistance, wherein the motor vehicle is subjected to the following method steps:

• a. Passage through a basin filled with saline solution and drizzle,
• b. exposure of salt solution and sprayed liquid for several hours during a test run on a test track,
• c. Setting down in a climatic chamber, with decreasing relative humidity, the temperature is kept constant and then the temperature and the relative humidity are increased.

The passage through the salt basin and drizzle ensures that the vehicle comes into intensive contact with the salt solution and the sprayed liquid. The saline solution can consist of a 1-5% sodium chloride solution or a mixed salt solution with calcium chloride additives. The action of saline solution and liquid for several hours during the running of a test run of the vehicle on a test track ensures that the saline solution and liquid can sustainably end up in areas that are not easily accessible, such as gaps, slots, cavities of the vehicle. The vehicle is then transported to a climatic chamber where it is exposed to different humidity conditions and temperatures. With decreasing relative humidity and constant temperature, a daily routine is simulated in temperate climates, while the subsequent increase in temperature and relative humidity simulates a tropical climate. This procedure can be repeated, preferably one cycle lasts 24 hours.

During this test run of the vehicle, in which the vehicle is dynamically and thermally stressed due to its operation, the saline solution and the sprayed-on liquid can have a particularly lasting effect on the vehicle.

Advantageously, the action of saline solution and liquid during driving over a longer period, for example, at least 5 hours. If the action is sustained over a period of 5 hours and the cycle is restarted after 24 hours, the vehicle is parked in the climatic chamber for the remaining time of the day, ie 19 hours.

In the climatic chamber, temperate climates are simulated over a longer period of time than the tropical climate. In this respect, it is considered advantageous from the point of view of the simulation of temperate climates, if the temperature is kept constant with decreasing relative humidity over 15 hours. In particular, with decreasing relative humidity, the temperature can be kept constant at 45 ° C and at constant temperature, the relative humidity from 95% to 50% can be lowered. Regardless of the specific values or duration, it is important that the relative humidity be varied during a test run. A preferred procedure provides that the relative humidity is partially lowered after every 1 or 2 hours. The moisture is removed in a controlled and not abrupt manner.

In the subsequent increase of temperature and relative humidity to simulate a tropical climate, it is preferably provided that the temperature and the relative humidity is increased over 4 hours. In particular, at elevated relative humidity, the elevated temperature 48 ° C to 50 ° C and it is at elevated temperature, the increased relative humidity 95%.

The method steps discussed above, namely passage through the salt pool and the spray mist, the action of saline and sprayed liquid, in particular during a test run on a test track, as well as the shutdown in a climatic chamber with simulation of the temperate climates and the tropical climate, preferably include a process duration of 24 hours. According to an advantageous procedure, this 24-hour process cycle can be repeated several times, preferably it repeats itself four times, so that there is a total duration of 120 hours.

According to a particular embodiment of the method according to the invention, it is provided that the vehicle is put into a freezing phase before, after or between the multiple process cycle, in particular the respective 24-hour process cycle. For example, the vehicle can be put in the freezing phase for 48 hours. The temperature during the freezing phase should be equal to or less than -20 ° C. Before the start of the repeated process cycle according to the invention, the cooled vehicle is exposed in particular to heating for one or two hours, in particular to a climatic chamber temperature of 20 ° C. The relative humidity during this heating is in particular 50%.

The method described in addition to training allows a test that is suitable for mixed construction, as it simulates the climate from outside according to the daily routine. In addition, the test can simulate the corrosion processes on the vehicle accelerated, resulting from a moderate increase in temperature or from a controlled decrease and increase in the relative humidity. For example, morning dew, noon drying, wet conditions in the tropics, and freezing phases during the winter months are simulated. Since most previous endurance runners only include abrupt jumps in relative humidity from 50% to 100% and vice versa, not all of the corrosion processes observed in the field under customer operation are adjusted. This ensures the inventive method.

Further features of the invention will become apparent from the dependent claims, the following description of the drawing and the drawing itself.

A preferred embodiment of the method according to the invention is illustrated in the drawing and explained in more detail in the following description. It shows:

1 for a 24-hour cycle of the method according to the invention the course of relative humidity and temperature,

2 a one-week test run with a 48-hour freeze period and five subsequent 24-hour cycles 1 , illustrated only for the first of the five process cycles, for the course of the relative humidity and the temperature.

The method simulates climatic or climatic phases, for example the tropics or winter months in temperate climates. It also simulates the course of relative humidity during the day. The illustrated climate cycle spans over a week.

1 shows a day of the climatic cycle, which is four times as shown in 1 repeated. This illustrates the first 5 days of the climate cycle.

After passing through a salt basin and drizzle according to area A, the motor vehicle completes a test run for 5 hours on a test track according to area B. Subsequently, the vehicle is parked for 19 hours in a climatic chamber according to area C. In this climatic chamber, the temperature is kept constant for 15 hours at a controlled decreasing relative humidity, which according to area D corresponds to the daily routine in temperate climates. Subsequently, according to region E, the temperature and the relative humidity are controlledly increased in order to simulate a tropical climate. After 24 hours, thus at time F, the process starts again, which is followed four times by process sequences A, B and C, the latter comprising regions D and E.

For the simulation of Arctic climates, the vehicle is in accordance with 1 after 5 days z. B. in a 48-hour freezing phase according to area G added. Then, after one hour of heating, the vehicle will be in the H range for the next 5-day cycle 1 supplied, in 2 again, only one cycle day following the two-day freeze phase is illustrated. After the identical 5-day cycle, the two-day freezing phase follows again.

Claims (18)

A method for testing a motor vehicle for its corrosion resistance, wherein the motor vehicle is exposed to environmental and weather conditions in a climatic chamber, characterized in that the motor vehicle is exposed to the following method steps: a. Passage through a basin filled with saline solution and drizzle, b. exposure to salt solution and sprayed liquid for several hours during a test run on a test track, c. Shut down in a climatic chamber, with decreasing relative humidity, the temperature is kept constant and then the temperature and the relative humidity can be controlled increased. The method of claim 1, wherein the exposure to saline and liquid is over 5 hours. The method of claims 1 or 2, wherein the vehicle is parked for over 19 hours in the climatic chamber. Method according to one of claims 1 to 3, wherein the temperature is kept constant with controlled decreasing relative humidity over 15 hours. Method according to one of claims 1 to 4, wherein with controlled decreasing relative humidity, the temperature is kept constant at 45 ° C. Method according to one of claims 1 to 5, wherein at a constant temperature, the relative humidity is lowered from 95% to 50%. The method of claim 6, wherein the relative humidity is partially lowered after every 1 or 2 hours. Method according to one of claims 1 to 7, wherein the temperature and the relative humidity is increased over 4 hours. Method according to one of claims 1 to 8, wherein at elevated relative humidity, the elevated temperature is 48 ° C to 50 ° C. Method according to one of claims 1 to 9, wherein at elevated temperature, the increased relative humidity is 95%. Method according to one of claims 1 to 10, wherein the process duration of the method steps a. to c. 24 hours. Method according to one of claims 1 to 11, wherein the from the method steps a. to c. formed process cycle several times, in particular four times repeated. The method of claim 12, wherein the vehicle is placed in a freezing phase before, after or between the multiple process cycle in the climate chamber. The method of claim 13, wherein the vehicle is placed in the freezing phase for 48 hours. A method according to claim 13 or 14, wherein the temperature during the freezing phase is -20 ° C. Method according to one of claims 13 to 15, wherein before the beginning of the multiple cycle of the process, the cooled vehicle is subjected to a one-hour warming, in particular at a temperature of the climatic chamber of 20 ° C. The method of claim 16, wherein the relative humidity during exposure to the refrigerated vehicle is 50%. The method of any one of claims 1 to 17, wherein the spray is a salt spray gene.

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