Structural Machining Aerospace


    Structural Machining Aerospace application has become one of the most important applications using the flexibility of Tricept modules with Loxin 2002 as integrator. Loxin has successfully installed their modules based on tricept technologies at the most important aeronautics customers based on its own range of machining centers based on tricept.


    Some of the projects where Loxin has been involved in the Aerospace sector are: Wing Box (Front and Rear Spars, Ribs, Stringers), Movables (Elevator, Rudder), and Fuselage (Skin panels and Stringers Assembly). Loxin has paid much attention to developping the necessary technology to assure the best tolerances on the countersinkings through the use of a patented Drilling tool holder.


    Loxin Drilling tool holder


    The biggest success in automation in this sector comes from the application for automatically Riveting Composite Sandwiches. Beyond drilling, Loxin has taken a big step forward offering its customers its all-included Automatic End effectors that allow fast and automatic drilling of varios types of compound layers (Composite, Aluminium, Titanium, etc.). These processes have a number of characteristics in which the combination of Tricept technology and Automatic End Effectors provide optimum solutions.

    Automatic Riveting Head

    The idea behing the development of this automatic drilling head was to create an end-effector that, combined with the Tricept capabilities, would include all the needed functions to perform automatic CNC riveting in 3D surfaces:


    - The previous standard process for the riveting operations included holed position through templates over the part. The hole positions where marked and then drilled and countersinked. After that, the riveting operation was done manually by the operators.


    - The new proccess based on the developed end-effector copes with all the necessary steps to get the product finished. In order to do that, in each and and every drilling-countersinking-riveting cycle, the follwing steps are followed by the system:


    1. Drilling and countersinking (controlled to the micron)
    2. Suction System (integrated in the tool holder)
    3. Thickness measurement
    4. Mastic Sealant application
    5. Rivets feeding
    6. Riveting
    7. Riveting tail measurement
    8. Shaving of broken pins

    First, the Tricept robot moves the tool holder in the programmed hole position. Then the drilling and countersinking are performed by moving the Tricept forward. The automatic countersinking depth control informs the machine when to stop. During the machining the suction system placed in the tool holder cleans the dust from the machined area.

    Tricept T805 with riveting end effector

    As a second step, the system changes automatically the TCP position parameters in order to poistion the thickness measurement tool. Then, the part thickness at the drill position is measured. With this measure, the rivet dimension in automatically selected from the rivets feeding cabinet. Thile the rivet is coming from the cabinet to the "rivets feeding position" the system updates the new TCP parameters and the sealant is applied in the countersinked area.


    Once the sealant is applied and the correct rivet has been selected, the new TCP position parameters are changed once more and the riveting operation is perfored. After it, the tail of the rivet is measured and stored for control and later use. Afterwards the cycle starts over again in a differente hole position. The described steps are perfored, all of them in around 30 seconds.


    After all the rivets have been placed, the ATC automatically removes the drilling and countersinking tool holder and put in place the "shaving holder". Then the information stored about the tails of the rivets if located and the rivets are shaved if needed. These riveting heads have already been installed in ten machines in Airbus Spain, obtaining a big reduction in process time in all operations where the tricept system has been installed.

    Riveting Head Loxin

    So far the whole range of tricept solutions have been used in aerospace applications, ranging from the tricept T605, through the tricept T805 to the tricept T9000 when bigger stiffness and harder materials need to be machined.