Pinch Roll Device Electro-Hydraulic Control
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Solution Overview
Problem
Existing pinch roll devices for metallurgic products face issues with controlling the distance and pressure between rolls due to constructional complexity, backlash, and high maintenance costs, leading to instability and surface faults in rolled products.
Innovation Solution
A pinch roll device utilizing a closed hydraulic circuit with a reversible pump controlled by an electric motor, integrated with position and pressure sensors, allows precise control of roll distance and pressure, eliminating the need for servo valves and reducing fluid usage, while ensuring continuous contact and high throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hydraulic actuators with servo valves are used to control roll distance, then roll positioning is achieved, but operating speed is low (40-50 Hz) and reactivity is poor
Solution Approach 1:
The patent replaces the mechanical servo valve system with a direct electro-hydraulic actuation system. The electric motor directly drives the hydraulic pump without mechanical transmission components, eliminating the speed limitations of servo valves while maintaining positioning accuracy through electronic control of the reversible pump.
Solution Approach 2:
The patent uses a closed hydraulic circuit with a reversible hydraulic pump to actuate the rolls. The hydraulic system provides high-speed response and precise positioning by controlling fluid flow to the hydraulic cylinder, achieving both high operating speed and accurate roll distance control.
2Ease of operation
If mechanical transmission chains with multiple members are used to connect motor to rolls, then roll movement is achieved, but backlash occurs and control precision is lost
Solution Approach 1:
The patent eliminates the mechanical transmission chain between the motor and rolls by using direct electro-hydraulic actuation. The electric motor drives a hydraulic pump that actuates the rolls through a hydraulic cylinder, removing all mechanical gears, belts, and linkages that cause backlash, thereby achieving precise distance control.
3Ease of manufacture
If open circuit hydraulic operation is used, then hydraulic actuation is achieved, but external hydraulic attachments are required and maintenance costs increase
Solution Approach 1:
The patent merges the hydraulic actuation circuit into a closed loop where the hydraulic pump is directly integrated with the actuator system. The hydraulic fluid circulates within the system without requiring external reservoirs or attachments, simplifying the overall device structure and reducing maintenance requirements while maintaining full hydraulic actuation capability.
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 achieves stable and precise control of roll distance and pressure, reducing material rejects and maintenance costs, enabling high-speed processing of metallurgic products with improved surface quality and reduced operational complexity.
Implementation Method 1
a hydraulic actuator (21) connected to the first roll (2) to approach it to or space it apart from the second roll (3)
Implementation Method 2
a reversible pump (9) connected to the hydraulic actuator (21) to slidingly move a piston (22) of the actuator (21)
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A pinch roll device (1 ) for rolled metallurgic products comprises: - a first pinch roll and a second pinch roll (2, 3), a passage gap (5) being defined therebetween, the first and second rolls (2, 3) being rotable about a first rotation axis and a second rotation axis (Y1, Y2), respectively, to draw a rolled metallurgic product (10) through the gap (5), - a hydraulic actuator (21, 41 ) comprising a hydraulic actuator (21, 42, 43) connected to the first roll (2) and/or the second roll (3) to reciprocally either approach or space apart the first and second rolls (2, 3), so as to either reduce or increase the width of the passage gap (5), respectively, - a pressure sensor (25) in the hydraulic circuit (20), - a position sensor (24) in the actuator (21 ), - a reversible pump (9) in the hydraulic circuit (20, 41 ) connected to the actuator (21, 42, 43) to slidingly move a piston (22) connected to the first roll (2) and/or to the second roll (3).