1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW3043 Defogging System Maximum Performance Validation of Windshield, Side Windows and Backlight Copyright 2012 General Motors Company All Rights Reserved December 2012 Originating Department: North American Engineering Standards Page 1 of 10 1 Scope
2、Note: Nothing in this standard supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. The purpose of this standard is the validation of the performance capability of a defogging sy
3、stem for the windshield, side windows, and the performance of the electrically heated backlight. 1.2 Foreword. Not applicable. 1.3 Applicability. The applicability for this standard is for all passenger vehicle defroster systems and electrically heated backlights. 2 References Note: Only the latest
4、approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. GMW15845 2.3 Additional References. None 3 Resources 3.1 Facilities. Climatic wind tunnel including a chassis dynamometer with adjusting possibilities for a dyna
5、mometer speed of 40 km/h minimum, a wind speed of 40 km/h minimum and an ambient temperature of -20 C minimum. 3.2 Equipment. 3.2.1 Temperature measuring and recording equipment for at least 13 measuring points. 3.2.2 Voltage and current measuring and recording equipment for compartment blower(s) an
6、d battery(ies). 3.2.3 Measuring and recording equipment for the engine speed. 3.2.4 Engine Oil, Coolant and Fuel. As released for the engine application at the test ambient temperature. 3.2.5 Device for operation and adjustment of accelerator pedal to accelerate and maintain vehicle speed. 3.2.6 Vap
7、or generator with water capacity adequate for generating 70 5 g/h water vapor per occupant seating position for 40 minutes. 3.2.7 Beaker for measuring the quantity of water required. 3.2.8 Timing device with stopwatch functions. 3.2.9 Means of recording cleared glass area for all tests (felt-tip mar
8、ker, camera, etc.) 3.2.10 Degrease using Methyl alcohol or equivalent degreasing agent. 3.2.11 Clean the window(s) with a cleaning agent of 3 to 5% ammonia or equivalent. 3.3 Test Vehicle/Test Piece. Test passenger vehicle with defroster systems and electrically heated backlights. Copyright General
9、Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3043 Copyright 2012 General Motors Company All Rights Reserved December 2012 Page 2 of 10 3.4 Test Time. Ca
10、lendar time: 1 days Test hours: 9 hours Coordination hours: 10 hours 3.5 Test Required Information. Blower setting, HVAC mode selection and time of mode change are to be recorded. 3.5.1 Blower setting and HVAC mode settings are per the appropriate program Vehicle Technical Specification (VTS). 3.5.2
11、 The vision areas of the windscreen are specified per Appendix B. The same vision area is used on benchmarking tests. 3.6 Personnel/Skills. Provide one climate tunnel operator, one driver and at least one in-vehicle observer. 4 Procedure 4.1 Preparation. The vehicle shall be prepared for the climati
12、c tunnel and shall be equipped with devices according to 3.2. 4.1.1 Cleaning of the Windows. The inner surfaces of all vehicle glass (including backlight) shall be completely degreased with methyl alcohol or an equivalent degreasing agent. After drying, an ammonia solution of 3 to 5% shall be applie
13、d. The surface treated in this manner shall be allowed to dry and then wiped with a dry cotton cloth. 4.1.2 Settings. Initially the vehicle ventilation system controls shall be set to full hot, Production Outside-Air (P/OSA) and defrost and high blower. 4.1.2.1 The blower setting and mode change dur
14、ing the test is specified by the corresponding Vehicle Technical Specification (VTS). Default setting shall be used for benchmarking tests. The default mode change is to change to defog mode, with blower speed a customer selectable value best approximating 50% of the high blower airflow volume (appr
15、oximately 6 V in a 12 V blower system) (See Table 2). 4.1.2.2 The center face outlets shall remain closed and the outboard face vents shall be aimed as much as possible at the center of the mirror patch on the front side windows. This setup is performed regardless of the vehicle having dedicated Sid
16、e Window Defogger (SWD) outlets. 4.2 Conditions. 4.2.1 Environmental Conditions. Ambient temperature: -20 1 C. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports,
17、 etc. 4.2.2.1 Soak. Allow vehicle to cool down with hood open. It shall be ensured that the entire vehicle is at a uniform temperature (vehicle mass, e.g., seat rail) of (-20 1C) prior to start of test. 4.2.2.2 Defogging Conditions. Vehicle and wind speeds as specified in the measurement program (se
18、e Table 2). 4.2.2.3 Electrical Power Supply. All electrical systems are supplied by the internal vehicle power supply. Headlights (low beam), backlight defogging system and heated seats (if standard equipment) are switched on (heated seats to maximum performance). If a time out occurs on either the
19、backlight defogging system or heated seats, they are to be turned back on for the duration of the test. 4.2.2.4 Dynamometer Load. Dynamometer loading is to be set to road load at a vehicle mass of curb weight plus the driver. The acceleration and deceleration rate is shown in Table 2. 4.2.2.5 Gear S
20、tep or Drive Position (See Table 1). Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3043 Copyright 2012 General Motors Company All Right
21、s Reserved December 2012 Page 3 of 10 Table 1: Gear Steps or Drive Positions Transmission Speed: 40 km/h Manual Transmission 4 Speed, 5 Speed, or 6 Speed 3rd Gear Automatic Transmission Drive 4.2.2.5.1 The specified dynamometer speeds are driven at road load (on level stretches without acceleration)
22、. 4.2.2.5.2 For repeat measurements on vehicles with automatic transmissions, it shall be ensured that same dynamometer speeds are driven at the same lowest engine speeds. 4.3 Instructions. 4.3.1 Measuring Program. Table 2: Measuring Program Temperature HVAC Vehicle Speed Wind Speed Duration 1 Soak
23、-20 C Blower Off 0 km/h 15 km/h Until Seat Rail at -20 1 C 2 Fog -20 C Blower Off 0 km/h 5 km/h 10 minutes 3 Test -20 C Full Hot Temperature, Defrost Mode, Maximum Blower Speed 40 km/h Note 1 40 km/h From Engine Crank (t = 0) Until drivers Critical Area is Cleared (t = Switch) 4 Test -20 C Temperatu
24、re Control to Maintain Breath Level Temperature Between 23 C and 25 C, Mode per VTS (Default Defog Mode, 6 V HVAC Blower) 40 km/h 40 km/h Switch t 50 minutes Note 1: Vehicle acceleration to be at 3.0 km/h/s, deceleration at 4.0 km/h/s. Accelerate vehicle at 3.0 km/h/s until vehicle speed target is r
25、eached, then adjust throttle to maintain test speed. 4.3.2 Water Vapor Generation. The hood shall be closed and water vapor shall be generated in the passenger compartment for 10 minutes. The amount of water vapor shall be 70 5 g/h for each passenger seating location. The water vapor generator shall
26、 be placed along the centerline of the vehicle, in the center of the vehicle passenger compartment (see Appendix A, Figure A1). 4.3.3 Windshield and Side Window Defogging. After 10 minutes of vapor generation, the observers shall enter the vehicle and the water vapor generator output shall be reduce
27、d by 70 5 g/h per each observer in the vehicle. Immediately afterwards the engine shall be started (t = 0 minutes) and the defogging procedure shall be performed at a vehicle and wind speed of 40 km/h. 4.3.3.1 At the commencement of the test, the compartment blower is set to maximum. The headlights
28、(low beam), the backlight defogging system and the heated seats (if standard equipment) are switched on. The defogged areas of the windshield and the side windows shall be marked by the observers at intervals of five (5) minutes or less. 4.3.3.2 After the drivers critical vision area (see Appendix B
29、) is cleared, the system shall be switched to the mode specified by the VTS (default is; defog mode with a HVAC blower of 6 V). The breath level temperature shall be maintained between 23 and 25 C, by modulating the temperature control. If a time out occurs on either the backlight defogging system o
30、r heated seats, they are to be turned back on for the duration of the test. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3043 Copyrigh
31、t 2012 General Motors Company All Rights Reserved December 2012 Page 4 of 10 Note: At: t = 50 minutes, the test is terminated. Note: If the HVAC blower utilizes a Pulse Width Modulator (PWM) control, 9 V to the blower shall use a customer selectable voltage that is the closest to providing 75% of th
32、e high blower system airflow in the appropriate HVAC mode, and 6 V to the blower shall represent a setting closest to providing 50% of the high blower system airflow. Note: Two HVAC modes are of customer interest after the driver critical vision area is cleared; defog 6 V and heater 9 V. The default
33、 selected above is a compromise between the higher airflow rate but cooler SWD outlet temperatures in heater mode at 9 V and the lower airflow but warmer SWD outlet in defog mode at 6 V. Both conditions should be studied during vehicle development to understand which customer usage condition results
34、 in less effective side window clearing and defog. In each mode selection, the procedure is to maintain occupant comfort via HVAC temperature door modulation. 4.3.4 Backlight Defogging. After 10 minutes of vapor generation, the observers shall enter the vehicle and the water vapor generator output s
35、hall be reduced by 70 5 g/h per each observer in the vehicle. Immediately afterwards the engine shall be started (t = 0 minutes) and the defogging procedure shall be performed at a vehicle and wind speed of 40 km/h. 4.3.4.1 The compartment blower is set to maximum. The headlights (low beam), the bac
36、klight defogging system and the heated seats (if standard equipment) are switched on. The defogged areas of the backlight shall be photographed by the observer(s) at intervals of five (5) minutes or less. Note: If the backlight defogger or heated seats are switched off automatically after a defined
37、time, they shall be switched back on. Note: At: t = 20 minutes, the test is terminated. Note: The steps per 4.3.3 and 4.3.4 may be performed at the same time, if possible. 4.3.5 Measuring Values and Data to Record. (See GMW15845). 4.3.5.1 Defogged Areas. At the completion of the test the defogged ar
38、eas shall be determined. 4.3.5.2 Temperatures in Degree Celsius (C). Ambient. Coolant, Heater In. Coolant, Heater Out. Coolant, Cylinder Head or Under Stat. Coolant, Radiator Out. Engine Oil (Bottom of the Oil Dipstick). Air, Windshield Defroster Left. Air, Windshield Defroster Right. Air, Front Sid
39、e Window Defroster Left. Air, Front Side Window Defroster Right. Air, Rear Side Window Defroster Left (if applicable). Air, Rear Side Window Defroster Right (if applicable). Breath Temperature at All Seating Positions. Mass Temperature of Body, e.g., Seat Rail. 4.3.5.3 Voltage in Volt (V) and Curren
40、t in Ampere (A). Compartment Blower(s). Backlight Defogging System. Battery(ies) (Only Voltage). 4.3.5.4 Speed in min-1 (or: Rotation per Minute (rpm). Engine. 4.3.5.5 Further Measurement Data. Vehicle Speed in km/h. Copyright General Motors Company Provided by IHS under license with General Motors
41、CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3043 Copyright 2012 General Motors Company All Rights Reserved December 2012 Page 5 of 10 Dynamometer Speed in km/h. Wind Speed in km/h. Traction Force of Chassis Dynamomet
42、er in Newton (N). 4.3.5 6 Further Data. Vehicle Data, Mileage and Description of the System to Validate. Test Number and Date. Name of the Observer(s) and the Person in Charge of the Test. List of Calibrated Test Equipment. 5 Data 5.1 Calculations. The defogged areas shall be calculated according to
43、 the windshield areas defined in Appendix B. There are two methods employed to calculate the area cleared vs. time. 5.1.1 Method One (1): Calculating Areas Cleared; Using the Computer Aided Drawing (CAD) System. 5.1.1.1 Transfer the defrosted pattern from the vehicle windshield to tracing paper. 5.1
44、.1.2 Scan the traced lines from the tracing paper to Math CAD using a two dimensional stylus. 5.1.1.3 Using a CAD system, overlay a windshield critical area template with the test result file and calculate areas cleared using the built-in functions in the CAD system. (This requires a template of the
45、 windshield areas to be generated in Math data and saved as a template). 5.1.2 Method 2: Calculating Areas Cleared; Using Mass of Tracing Paper. 5.1.2.1 Transfer the defrosted pattern from the vehicle windshield to tracing paper. 5.1.2.2 Transfer the windshield critical area template onto the tracin
46、g paper containing the defroster patterns. 5.1.2.3 Cut out the drivers side clearing area template (Critical Vision Area (CVA) per Appendix B, B1), and the windshield clearing area template and weigh using a calibrated scale with an accuracy of 0.01 g. 5.1.2.4 Cut out the defrosted areas at the time
47、s set out in the VTS and weigh to determine mass of cleared areas. 5.1.2.5 Calculate percentage of the areas cleared using the mass of the entire template area and the defrosted areas. 5.2 Interpretation of Results. The targets are defined by the VTS. 5.3 Test Documentation. With reference to this t
48、est procedure the results of the measurements shall be presented in a test report following a format similar to that shown in Appendix C, Data Sheet C1. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problem
49、s associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Defog: HVAC mode whereby airflow is directed towards both the foot and windshield, also referred to as blend mode. Defogging: With the engine running, t
