Reciprocating Knife Assembly for Continuous Extruded Product Cutting
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Solution Overview
Problem
Existing mechanical devices for cutting and portioning extruded products face limitations in speed and accuracy due to intermittent operation, leading to excessive wear, fluctuations in product weight and shape, and high maintenance costs, while continuous cutting systems often result in incomplete cuts.
Innovation Solution
A knife assembly that reciprocates on a continuously moving conveyor system, actuated by a cam and spring mechanism, allowing the blade to pass through a die for clean cuts without stopping the product flow, with servo-driven feed belts and a profiled cam set for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the knife is actuated intermittently to cut product portions, then clean cuts are achieved, but production speed is limited and component wear increases
Solution Approach 1:
The knife assembly is made dynamic by allowing it to reciprocate at different speeds during its cycle. The forward movement speed matches the conveyor speed for clean cutting, while the return movement occurs at a different speed. This dynamic adjustment enables continuous operation at high speed while maintaining cut quality.
Solution Approach 2:
The system achieves continuous cutting action by overlapping the knife reciprocation cycle with the continuous conveyor movement. The knife cuts portions during the forward stroke while the conveyor continuously transports product, eliminating interruptions in production flow and maintaining constant productivity.
2Productivity
If the knife assembly reciprocates at high speed, then productivity increases, but the risk of blade sticking to product increases
Solution Approach 1:
The knife assembly employs periodic reciprocating motion with distinct forward and return strokes. The forward stroke performs cutting at matched speed, while the return stroke creates a speed differential that prevents blade sticking. This periodic acceleration and deceleration cycle continuously eliminates the harmful sticking effect.
Solution Approach 2:
The system changes the velocity parameter of the knife assembly during its cycle. The forward velocity matches the conveyor velocity for clean cutting, while the return velocity is adjusted to create separation. This parameter variation prevents blade sticking while maintaining high productivity.
3Productivity
If the conveyor system is lengthened to accommodate knife reciprocation, then continuous cutting is enabled, but system complexity increases
Solution Approach 1:
The conveyor system incorporates dynamic elements that allow it to function continuously while accommodating the reciprocating knife. The conveyor belts and rollers are designed to maintain continuous movement independent of the knife cycle, eliminating the need for system lengthening and reducing complexity.
4Object-affected harmful factors
If the knife is accelerated forward after cutting, then blade sticking is reduced, but energy consumption increases
Solution Approach 1:
The knife assembly uses periodic reciprocating motion with built-in acceleration phases. The forward acceleration after cutting naturally prevents blade sticking through the speed differential, and the periodic nature of the cycle ensures this acceleration occurs only when needed, minimizing unnecessary energy consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution increases production speed and accuracy, reduces operational costs and maintenance, and improves product quality by enabling continuous processing of extruded products like ground meat at rates of 150 pieces per minute or more, while minimizing wear on system components.
Implementation Method 1
The knife assembly can be actuated by a profiled cam set that pulls the blade down, and then returned by progressive springs
Implementation Method 2
The knife assembly can be actuated by a profiled cam set that pulls the blade down, and then returned by progressive springs
Implementation Method 3
The feed belts and knife assembly can be servo driven for accurate control
Data Source
AI summary
An input conveyor, output conveyor, and knife assembly with a blade between the input and output conveyors all reciprocate back and forth as a blade moves perpendicular to the conveyors to cut portioned sized of product, such as ground meat. The cut cycle allows the product feed to keep moving in a continuous manner on conveyors. For ground meat, this system can allow production rates of 150 pieces or more per minute per conveyor line and can improve the accuracy of portioning. The blade is actuated by a profiled cam set that pulls the blade down, and then returns it with a spring to an upper position. The knife assembly can accelerate just after cutting to reduce the potential for sticking to the cut product.