TH4414A - Rotary welding machine - Google Patents

Abstract

The rotary welding machine consists of a rotary welding head with a rotating welding head 16, a tamper assembly 15, and a feeding mechanism 12. The tamper assembly is driven by shaft 8, and the feeding mechanism consists of a rotating turret mounted on shaft 13, which is driven by shaft 8 via a Geneva mechanism 14. The rotary welding head 16 is driven by a low-inertia DC servo motor 17, which is operated by a programmable logic controller and timer from a switch unit 18, which is driven from shaft 8.

Claims (6)

1. A rotary welding machine for joining opposing thermoplastic components that are assembled together before welding consists of a rotating welding head for rotating one component relative to another and a low-inertia DC servo motor for driving the rotating welding head. The servo motor drive is controlled by a programmable logic controller, which is programmed to initially rotate at a slow speed to ensure a tight fit of the components, rapidly accelerate the welding process, maintain the process speed for the desired period, and finally rapidly decelerate and stop the motor. 2. The instrument under claim 1 consists of a pressure path for applying a pre-selected radial pressure to opposing surface elements while the servo motor welding process speed is constant, and a control path for measurement during slow-start rotation. The parameters, which are a function of the insertion between the two welded elements, are for comparing the parameters to a set value and for selecting the radial pressure value by the pressure path. 3. The device under claim number 2, where the measured parameter is the voltage generated by the servo amplifier as an analog of the servo motor current during initial rotation. 4. A device that provides for any one of the claims under Claims 1-3, in which a programmable logic controller is connected to a servo motor via an amplifier. 5. Under claim number 4, the programmable logic controller is programmed to continue from the final power interruption to the amplifier during the aforementioned time period, i.e., the servo motor is decelerated and stopped by friction at the joint. 6. A machine that provides for one or more of the claims in Claims 1-5, which also includes a feeding mechanism for sequentially feeding pre-assembled components to the workstation on the machine, and an assembly for sliding the components at the workstation into contact with the rotating welding head, where the feeding mechanism and the pushing assembly are driven in relation to time by the first motor drive shaft, and where the servo motor drive is timed by a switch unit driven by the first shaft (Claims 6, 2 pages, 11 figures).