Excavator Coupler Locking Mechanism for Hydraulic Failure Safety
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Solution Overview
Problem
Existing hydraulic couplers for excavators face reliability issues due to debris interference and failure in harsh environments, leading to potential implement detachment and safety hazards, especially when hydraulic pressure is lost.
Innovation Solution
A coupler design with a fixed and movable jaw, each equipped with a locking mechanism, operated by a linear actuator, ensures both pins are securely engaged through a non-linear entry path and biased locking members, preventing detachment even in hydraulic failure scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a safety lock system is added to lock both pins, then reliability is improved, but device complexity increases
Solution Approach 1:
The locking mechanism is divided into two independent locking members (first locking member for first pin, second locking member for second pin), each capable of independent operation. This segmentation allows the system to lock both pins separately, improving reliability while maintaining manageable complexity through modular design.
Solution Approach 2:
The actuator's linear movement is combined with cam surfaces to simultaneously control both locking members. The cam surfaces convert the linear actuator movement into rotational movement of both locking members, merging one actuation source to control multiple locking functions, thereby reducing overall system complexity.
2Strength
If locking members are made robust to withstand large loads, then strength is improved, but debris interference increases
Solution Approach 1:
The locking members utilize cam surfaces with curved geometries instead of flat or sharp edges. The cam surfaces are designed with specific radii of curvature that allow smooth rotational movement while maintaining structural strength. This curvature reduces stress concentration points where debris could accumulate and prevents jamming while withstanding large loads.
Solution Approach 2:
Different regions of the locking members have different geometric properties optimized for their specific functions. The cam surfaces have smooth curved regions for actuation, while the locking engagement regions have robust geometries for withstanding loads. This local differentiation allows the locking members to be strong where needed while having smooth surfaces that resist debris interference in actuation areas.
3Reliability
If a non-linear entry path is used for pin engagement, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The pin engagement path transitions from a simple linear insertion to a non-linear path that includes rotational and lateral movements. The lip on the first jaw and the cam surfaces guide the pin through a multi-dimensional engagement sequence, ensuring proper alignment and secure locking. This dimensional complexity improves reliability by ensuring positive engagement but requires higher manufacturing precision for the guiding features.
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 coupler maintains secure attachment of implements under hydraulic failure by using non-linear pin engagement and biased locking mechanisms, enhancing reliability and safety in harsh conditions.
Implementation Method 1
the locking member is biased towards its locking position
Data Source
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AI summary
A coupler for coupling an implement having first and second spaced apart parallel pins, to the arm of a vehicle. The coupler has a body for attaching to the vehicle arm, a first fixed jaw, a movable second jaw facing away from the first jaw, and an actuator to selectively move the second jaw towards and away from the first jaw. The first jaw includes a lip forward of the seat for the first pin. A first locking member is pivotable between a locking position, in which a portion of the locking member protrudes into the opening of the first jaw, and an unlocked position. A second locking member is pivotable between a locking position in which a portion of the second locking member constricts the opening of the second jaw, and an unlocked position. Movement of the second jaw causes movement of the first locking member.