Ball-Screw Lift Control for Precise Variable Compression Engines
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Solution Overview
Problem
Existing ball-lift compression ratio adjustment devices for variable compression ratio engines face issues with precision control, durability, and reliability due to limitations in lift height variation, wear, and repeatability, particularly with solenoid valves and piezoelectric components.
Innovation Solution
A screw ball lifting device with a rotary electric motor driving screws to lift or remove balls from their seats, allowing continuous precision control of lift height and preventing wear-related precision issues, using a double-acting hydraulic control cylinder with non-return valves and a cylindrical pusher for hydraulic fluid management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solenoid valves or piezoelectric components are used for ball lifting, then the compression ratio can be adjusted, but precision control and durability are compromised due to wear and limited lift height variation
Solution Approach 1:
The patent replaces solenoid valves and piezoelectric components with a screw mechanism driven by a rotary actuator. This mechanical substitution eliminates the wear and precision issues associated with electromagnetic and piezoelectric components, providing durable and precise lift height control for the balls in the hydraulic system.
Solution Approach 2:
The screw mechanism allows continuous variation of the lift height parameter, enabling precise control of ball displacement. By changing the rotational position of the screw, the system can achieve any lift height within its range, overcoming the limited variation of fixed-lift solenoid and piezoelectric components.
2Adaptability or versatility
If solenoid valves are used for ball lifting, then compression ratio adjustment is enabled, but wear leads to loss of precision and repeatability
Solution Approach 1:
The screw mechanism driven by a rotary actuator replaces solenoid valves, providing a wear-free method for compression ratio adjustment. The screw's threaded geometry maintains consistent lift height repeatability over time, eliminating the precision degradation caused by solenoid wear while preserving full adaptability of compression ratio control.
3Device complexity
If fixed lift height mechanisms are used, then device complexity is reduced, but precision control of compression ratio is limited
Solution Approach 1:
The screw mechanism transforms the rotary motion of a simple actuator into precise linear displacement of the ball. This dynamic conversion allows a low-complexity actuator to achieve high precision lift height control, maintaining simplicity while enabling continuous precision adjustment of the compression ratio.
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
Enables precise and repeatable control of compression ratio adjustments with improved durability and reliability by ensuring consistent lift heights and preventing wear, enhancing the engine's operational efficiency and performance.
Implementation Method 1
at least one rotary electric motor intended to drive in rotation at least one screw
Implementation Method 2
enabling the lifting or lowering from its seat at least one ball or valve of a control cylinder
Implementation Method 3
which, when held by a spring on its seat, acts as a check valve
Implementation Method 4
so as to allow hydraulic fluid to pass in only one direction
Data Source
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AI summary
The screw ball lifting device for a variable compression ratio motor comprising a double-acting hydraulic control cylinder (8) having an upper chamber (121) and a lower chamber (122) and at least one cylinder piston (13) connected to a control rack (7) includes: • At least two balls (401, 402) or valves each resting on a seat (403, 404) and respectively closing one and the other end of a transfer channel (405) connecting the upper chamber (121) and the lower chamber (122) of the control cylinder (8), said balls (401, 402) acting as a check valve when held on their seat (403, 404) by a spring (408, 409) so as to allow the hydraulic fluid to pass in only one direction;• And lifting means (410) comprising at least one electric motor (480) intended to drive in rotation at least one screw (481, 482) enabling the lifting or lowering from its seat (403, 404) of at least one ball (401, 402).