1. Confirm the back hinge shaft center position
The completed data shall be verified before the installation design of the air spring for the tailgate automobile. Confirm whether the two hinges of the back door are coaxial; Whether the hatch door interferes with the surrounding area of the vehicle body during the whole process of rotation along the hinge axis: automobile gas spring installation Whether the space is fully reserved.
2. Determine the total mass of the back door and the position of the center of mass
The total mass of the back door is the sum of several components made of metal and non-metallic materials. Including back sheet metal parts, glass, rear wiper system, license plate lamp and trim panel, rear license plate, back [lock and back door trim panel, etc. On the premise of knowing the density of parts, the weight and centroid coordinate point can be automatically calculated.
3. Determine the position of the mounting point of the gas spring on the back door
Here is the installation point theory of gas springs for automobiles The upper refers to the rotation center of the ball head at both ends of the automobile gas spring. When installing the gas spring for automobiles, the piston is generally placed at the top and the piston rod is placed at the bottom. The connection between the automobile gas spring and the inner plate must be transited by the bracket installed on the inner plate of the back door to keep away the outer diameter of the piston and the movement space. The inner side of the door inner plate must have a reinforcing nut plate to install the automobile gas spring bracket. The strength of the back nut plate and bracket, and the stiffness of the back door must meet the requirements of the automobile gas spring under heavy stress. The mounting position of the automobile gas spring on the bracket is the upper mounting point position of the automobile gas spring. The size from this position to the hinge shaft center affects the supporting force required by the automobile gas spring. Under the condition of constant load torque, the size decreases by 10%, the supporting force of the automobile gas spring will increase by more than 10%, and the travel of the automobile gas spring will also change accordingly. The design goal should be to minimize the support force required by the automotive gas spring on the premise of meeting the hatch door opening and convenient access to both sides of the hatch, because excessive support force will increase the manufacturing cost of the automotive gas spring and the stiffness requirements of the hatch door.
4. Determine the opening angle of the back door
Determine the hatch door opening according to ergonomics analysis. At present, there is no regulation on the ground clearance when the back door is opened to the lower edge of the large position door. According to the convenience of people standing on the ground, when the door is opened to a large position, the low point height of the lower part of the back door
The opening angle of the back door shall be determined at about 1800mm above the ground. This design is based on the consideration that the head of the person is not easy to touch the low point of the lower part of the back door, and the hand can easily contact the handle when closing the door. Due to the different height and structure of the vehicle body, the opening angle of the back [] of each vehicle model is also different, which is roughly 100 ° - 110 ° from the vertical direction. At the same time, the large opening angle of the back [] shall be less than the large opening angle that the hinge can reach; The automobile gas spring runs to the end of the stroke and has a buffer mechanism to avoid damage to the components.
5. Establish the three-dimensional digital model of automobile gas spring and design the installation and connection mode
According to the existing basic parameters of automobile gas spring and the selected specification form of automobile gas spring, the 3D digital model of automobile gas spring shall be established. The expression content shall include the external dimensions of automobile gas spring, movement stroke relationship, structure form of both ends, ball head movement relationship, bolts, etc. The connection forms at both ends of automotive gas springs are different, and the connection methods shall be matched according to the installation position and the product specifications of the selected supplier. Some use mounting brackets at both ends, and some are directly fixed on the vehicle body.
Post time: Dec-16-2022
