C-Frame Tool Closing System for Blow Molding Machines
Solution Overview
Problem
Existing tool closing systems for blow molding machines face issues with bending moments in guide elements, leading to deformation and complexity, particularly in large mold projections, which complicates force distribution and accessibility.
Innovation Solution
The system employs parallel C-shaped frame elements for force transmission between mold clamping plates, eliminating bending moments and maintaining parallel alignment, with simplified kinematics and cost-effective design, allowing easy access and distribution of forces across the mold width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a lever mechanism is used for force transmission, then symmetrical force introduction is achieved, but the mechanical structure becomes relatively complicated and opening stroke increase is difficult
Solution Approach 1:
The patent extracts the lever mechanism from the force transmission system and replaces it with a direct linear drive connection. The drive unit (7) acts directly on the mold clamping plates (4, 5) through the drive rod (8), eliminating the need for complex lever mechanisms while maintaining symmetrical force introduction.
Solution Approach 2:
Instead of using a lever mechanism that requires complex articulations and intermediate plates, the patent inverts the approach by using a direct linear transmission system where the drive rod moves parallel to the mold clamping plates, simplifying the overall structure.
2Force
If a bottom type drive is used, then symmetrical force introduction is achieved, but the structure becomes complicated and accessibility is reduced
Solution Approach 1:
The patent transitions from a bottom-type drive arrangement to a rear-type drive arrangement where the drive unit is positioned behind the third plate (crosshead). This dimensional change in drive location improves accessibility underneath the mold while maintaining force transmission effectiveness through the C-shaped frame elements.
3Stability of the object's composition
If rack or lever synchronization is used for synchronous movement, then mold halves move towards joint parting plane, but deformations occur in guide elements due to bending moments
Solution Approach 1:
The patent introduces C-shaped frame elements (12) as intermediary components between the drive unit and the mold clamping plates. These frame elements act as mediators that transmit force without creating bending moments in the guide elements, as the articulation points (13, 18) are positioned to eliminate such moments while maintaining synchronous movement.
4Manufacturing precision
If complex lever mechanisms or intermediate plates are used to prevent bending in guide system, then force transmission is improved, but device complexity increases
Solution Approach 1:
The patent removes the complex lever mechanisms and intermediate plates from the system. Instead, it uses a simplified direct connection system where the drive rod acts parallel to the mold clamping plates, and the C-shaped frame elements provide the necessary force transmission without requiring complex articulations to prevent bending.
Data Source
AI summary
A tool closing system for plastic blow molding machines comprises a drive base plate, a front mold clamping plate and a rear mold clamping plate positioned between the front clamping plate and the base plate. The base plate, front clamping plate, and rear clamping plate are shiftably arranged on guides which are mounted on a carriage. A drive device is fastened to the base plate and comprises an extensible and retractable drive rod which is articulated to the rear clamping plate for force transmission without bending moment. Two substantially C-shaped or U-shaped frame elements are arranged side by side in parallel with the guides. Each have a substantially horizontally extending central web and two substantially vertically extending webs. A respective one of the two vertical webs is articulated to the base plate and the other vertical web is articulated to the front clamping plate.