Pressing Machine Crankshaft Synchronization via Linkage
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Solution Overview
Problem
Existing pressing machines with crankshaft-driven mechanisms face difficulties in smoothly transmitting rotary motion due to dead centers, leading to poor start/stop performance, press forming accuracy, and increased cycle times, and are burdened by complex structures and high costs due to the use of gear members with large moments of inertia.
Innovation Solution
A pressing machine design featuring co-axially disposed crankshafts with eccentric shafts, connecting rods, and levers that transmit rotary motion without gear members, ensuring synchronization and eliminating dead centers through the cooperative actions of first and second connection levers, thereby improving start/stop performance and press forming accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gear members are used to transmit rotary driving force among crankshafts, then the structure is robust and reliable, but the moment of inertia becomes extremely large, resulting in poor start/stop performance and low operating response
Solution Approach 1:
The patent removes gear members from the rotary force transmission mechanism, extracting the harmful large moment of inertia while maintaining the essential function of synchronous rotation among crankshafts through alternative linkage mechanisms
Solution Approach 2:
The patent employs dynamic linkage mechanisms (connecting rods and levers) that allow for smoother acceleration and deceleration of crankshafts, enabling better start/stop performance compared to rigid gear connections
2Adaptability or versatility
If multiple gears and links are used to transmit driving force, then the structure can accommodate complex motion requirements, but the device complexity increases significantly with many components
Solution Approach 1:
The patent combines multiple transmission functions into integrated linkage structures where connecting rods and levers simultaneously perform force transmission, motion conversion, and synchronization functions, reducing the total component count
Solution Approach 2:
The linkage components are designed to perform multiple functions: connecting rods transmit force and enable motion conversion, while levers provide both structural support and motion control, eliminating the need for dedicated single-function components
3Device complexity
If yokes are used to transmit rotary motion among crankshafts, then the structure is simplified, but dead centers are created where the direction of rotation becomes instantaneously unfixed, preventing smooth transmission
Solution Approach 1:
The patent employs dynamic levers with controlled degrees of freedom that maintain continuous rotational direction control, eliminating the instantaneous unfixed state that occurs at dead centers in yoke mechanisms
Solution Approach 2:
The patent introduces intermediary linkage components (connecting rods and levers) that mediate the force transmission between crankshafts, preventing the direct linear force transmission through yokes that causes dead center problems
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
The solution enables smooth rotary force transmission among crankshafts, enhancing start/stop performance, reducing cycle times, and simplifying the machine structure to lower production costs while maintaining high press forming accuracy and concentricity.
Implementation Method 1
each of which has two co-axially disposed main shaft portions and an eccentric shaft portion disposed between and eccentrically with respect to the two main shaft portions
Implementation Method 2
the eccentric shaft portions and the pins have a phase difference of 90° therebetween during the rotary motions of the crankshafts
Data Source
AI summary
A pressing machine having a structure improved to smoothly transmit a rotary driving force among a plurality of crankshafts, and so as to have improved start/stop performance and improved press forming accuracy, and so as to permit reduction of a cycle time required for forming the desired product. In the pressing machine having a plurality of crankshafts (34) each having main shaft portions (30) and an eccentric shaft portion (32), at least one first connection lever (48) is attached to the eccentric shaft portions (32) of the plurality of crankshafts for rotating the plurality of crankshafts in synchronization with each other, and a second connection lever (56) is attached to pins (54) which are formed integrally with the respective crankshafts, and positions of which as seen in a circumferential direction of the main shaft portions are different from those of the eccentric shaft portions.