Dual-Motor Bolt Tension Tightening for Accurate Nut Fastening

The patent replaces traditional mechanical tightening methods (torque method, turn-of-nut method) with a tensile force-based tightening system. A tensioning device applies controlled tensile force to the bolt, directly tensioning the screw section to achieve precise target tightening force. This substitution of the tightening mechanism eliminates the variability inherent in torque-based methods while maintaining relative simplicity through direct force application and sensing.

The patent incorporates a sensor that detects the tensile force acting on the screw section in real-time. This feedback mechanism allows the tightening device to monitor the applied force and adjust accordingly to achieve the target tightening force with high precision. The sensor provides continuous information about the tightening state, enabling closed-loop control that eliminates the ±20% to 50% variability of open-loop mechanical methods.

The patent replaces reliance on large fastener size to generate sufficient tightening force with a controlled tensile force application system. By using a tensioning device that directly applies the required force to the screw section, smaller fasteners can achieve the same tightening effect without needing excessive size margins. This eliminates the need to oversized fasteners while maintaining the required tightening force.

The patent changes the fundamental parameter for controlling tightening from torque or rotation angle to direct tensile force measurement and control. By monitoring and controlling the tensile force on the screw section rather than relying on mechanical leverage through large fastener dimensions, the system achieves precise force application with appropriately sized fasteners, reducing the weight of the fastening target object.

The patent extracts and removes the complex planetary gear mechanism and clutch assembly from the tightening system. By using a direct tensile force application method with a tensioning device, the system achieves precise tightening control without requiring these complex transmission components. This extraction of unnecessary complexity simplifies the mechanism while maintaining or improving precision through direct force control and sensing.

The patent substitutes the mechanical transmission system (planetary gear mechanism and clutch) with a direct force application and sensing system. Instead of using complex mechanical components to control and transmit drive force, the system directly applies tensile force to the screw section and monitors it with a sensor, achieving precise control with a simpler mechanism that requires no automatic attachment and detachment of members.

The patent uses a sensor to detect the tensile force on the screw section and provides feedback control to achieve the target tightening force with high precision. This eliminates the need to apply excessive tightening force as a safety margin, because the system can reliably achieve and maintain the exact target force. The feedback mechanism ensures consistent, precise tightening that maintains safety without requiring oversized fasteners or excessive force application.

The patent replaces torque-based or rotation-based tightening methods with direct tensile force control, enabling precise achievement of target tightening force without variability. This substitution allows for reliable, consistent tightening that maintains safety margins through precision rather than through excessive force or oversized components, thereby reducing the space and weight requirements of the fastening target object.