Design
Design
Sun roof assembly
1. Sun roof frame
2. Drain channel
3. Glass panel
4. Sunshade (closed)
5. Sun Roof Module (SRM)
6. Motor
7. Drive cables
8. Mechanism
The drive mechanism consists of the Sun Roof Module (SRM), motor and mechanism with drive cables. The Sun Roof Module (SRM) with motor is connected to the vehicle electrical system.
Sun roof frame
The sun roof frame is designed to hold all components together and to maintain rigidity, which keeps the movements of the mechanism stable. The A-frame struts serve as guide rails (1) for the drive mechanism. The guide rails contain fixed notches (8), which are necessary for the function of the mechanism. The center member (2) is riveted between the guide rails to increase frame strength and is used for mounting the edging. The front member (4) houses mountings (3) for the motor and Sun Roof Module (SRM). There are eight mounting points (6) along the guide rails and front member to mount the sun roof in the body.
The frame also serves to lead rain water to the drain hoses housed in the four corners (5). The drain channel, which is not part of the frame, collects the water and leads it to the guide rail channels in the frame. These channels are connected to the drain hoses (5) in the front edge and the drains with drain hoses (7) in the rear edge. The drain hoses, drains and connections between the front crossmember and the guide rails are sealed to prevent water from leaking into the headlining.
Drain channel
The drain channel is designed to lead rain water to the guide rail channels. The drain channel is mounted on the mechanism and moves along with the glass panel when it slides back.
When the sun roof is closed, the drain channel lies under the glass panel seals to catch any water that may leak in. When the sun roof is in the tilted position, the drain rail is positioned farther forward to catch rain water and prevent it from entering the passenger compartment.
Glass panel
The glass panel (2) and sunshade are the visible components of the sun roof. The glass provides extra light to the drive and passengers while protecting them from cold air and rain. The panel is made of safety glass to protect the driver and passengers. It is mounted on metal reinforcements (3) and side brackets (4). The glass panel is mounted in the drive mechanism with screws in the side brackets. The reinforcements are secured to the glass with adhesive, which provides extra rigidity against impact and wind load. The glass edge is covered with a rubber seal (1) that keeps out rain water and dust.
Sunshade
The sunshade protects the driver and passengers from intense sunlight and also serves as an insulator. The sunshade is usually opened and closed manually. If, however, the glass panel is open to the comfort position or is completely open, the sunshade is opened by the drain channel, which moves the sunshade back to the open position. The spring-loaded carriages (1) sit in the guide rail and allow the sunshade to slide easily.
Drive cables
1. Drive cables
2. Drive plate
The two sun roof drive cables constitute the connection between the motor and the drive mechanism. Each cable is of a worm type, which moves forward or back by the motor turning a gear wheel. The rear end of the cable is fixed in the drive plate, which is connected to the drive mechanism. The cable moves in the guide rail and drive tube.
Drive mechanism
The drive mechanism is depicted above. The mechanism bears the glass panel and moves it to the various positions. The left and right mechanism each have two mounting points for the glass panel (1). The drive mechanism can move through the guide rail on carriages (2). Because the carriages slide through the rail, it must be well lubricated.
The drain channel is mounted on the support (3) and the drive plate on the carriage (4).
Sun Roof Module (SRM)
The Sun Roof Module (SRM) regulates the sun roof motor with the help of software. This software regulates pinch protection, calibration and drive mechanism movements.
- Pinch protection is a safety requirement to prevent anyone from getting injured when the sun roof is closed. Maximum closing force up to 50 km/h (30 mph) is 100 Nm. Over 50 km/h (30 mph), the closing force is adjusted based on vehicle speed to compensate for wind resistance.
- The sun roof is calibrated by opening the glass panel to its end position (completely open), which is then set as its zero position. The Sun Roof Module (SRM) must be calibrated for the panel to be able to find its main positions and for the pinch protection function to be active. The sun roof must be calibrated each time it has been disassembled. Calibration is performed following the information in VIDA under Repairing/Cleaning, checking and adjusting.
The following are the main glass panel positions programmed in the Sun Roof Module (SRM):
Tilted position
Closed
Open
Comfort position
The Sun Roof Module (SRM) determines the positions using a slotted gear wheel and two light sensors. These measure the number of gear wheel revolutions, which is proportionate to glass panel displacement.
Sun roof motor
The sun roof motor is connected (1) to the Sun Roof Module (SRM), which regulates current to the motor. Nominal system voltage is 12 V. Maximum top load during normal operation is 5 A. The motor drives a gear wheel (2), which engages the drive cables and causes them to rotate. The gear wheel has a maximum torque of 2.0 Nm and the motor has thermal overload protection. The motor is mounted with screws in the three mounting points (3) in the sun roof frame.
Caution! In the event of mechanical blockage, which is normally prevented by the Sun Roof Module (SRM), the motor can produce a maximum torque of 6.8 Nm. This can damage drive wheels and cables. If the sun roof has been blocked, all sun roof components must be checked and, if necessary, replaced before recalibration.