Bolt Clamping System for Blow Mold Halves
Solution Overview
Problem
Existing blow molding systems face challenges in maintaining the closed position of blow mold halves during the blow molding process due to insufficient cam-controlled forces, leading to incorrect container formation and the formation of a 'parting line' due to insufficient contact pressure between the mold parts.
Innovation Solution
A bolt clamping system with adjustable clamping bolts and chucks is used to securely lock the blow mold halves together, generating a clamping force of 10-50 kN per locking device, which ensures precise positioning and sufficient contact pressure within the blow cavity, potentially eliminating the need for additional locking devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking device is provided to connect the blow mold parts in the closed position, then the blow mold parts are prevented from pivoting apart, but a time offset is required between reaching the closed position and introducing blowing pressure, which affects production time
Solution Approach 1:
The bolt clamping system is designed to automatically engage and generate clamping force as the blow mold parts approach the closed position, rather than requiring a separate locking action after closure. The clamping bolts are pre-positioned to engage with the chuck at the closed position, eliminating the need for a time offset between closing and locking.
2Reliability
If a locking device is provided to prevent pivoting apart, then the blow mold parts are secured in the closed position, but insufficient contact pressure between the blow mold parts allows gaps to form, resulting in a parting line on the beverage container
Solution Approach 1:
The bolt clamping system generates adjustable clamping forces (10-50 kN per locking device) that can be optimized to achieve sufficient contact pressure between the blow mold parts. The system transitions from binary locking (locked/unlocked) to continuous adjustable clamping, allowing precise control of contact pressure to eliminate gaps and parting lines.
3Manufacturing precision
If additional locking devices are provided to press the blow mold parts together to eliminate gaps, then contact pressure is improved, but the device complexity increases
Solution Approach 1:
The bolt clamping system serves multiple functions simultaneously: it locks the blow mold parts in the closed position, generates sufficient contact pressure to eliminate gaps, and provides adjustable clamping force. This multi-functional design eliminates the need for separate locking devices and pressure application mechanisms, reducing overall device complexity while achieving the required manufacturing precision.
Data Source
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AI summary
The present invention relates to a blow molding unit for a blow molding machine for forming plastic preforms into containers, comprising at least one blow mold (1) and a blowing device associated with the blow mold (1), wherein the blow mold (1) is formed from at least a first and a second blow mold part (2, 3) which are movable relative to each other between an open and closed position, and wherein at least one locking device (6) is provided which locks the blow mold parts (2, 3) together in the closed position. According to the invention, the locking device (6) is designed as a bolt clamping system with clamping bolts (8) and a chuck (7) which can be set into a locking position.