Cabin Door Lock Layout for Excavator Open-State Stability
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Solution Overview
Problem
The manufacturing cost of cabins for work machines is increased due to the need for custom cabins for each type of work machine with different-sized support bodies, and existing lock devices on the cabin side fail to hold the door in fully open state when the support body protrudes sideways.
Innovation Solution
A work machine configuration featuring a cabin with a center pillar and a rotatably supported door that can be opened forward, and a support body with a lock device to hold the door in a fully open state, allowing the same cabin to be used across different-sized support bodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a lock device is provided on the cabin side to hold the door in a fully open state, then door fluttering is prevented, but the door cannot be held when the support body protrudes sideward and the door hits the support body
Solution Approach 1:
The lock device is relocated from the cabin side to the support body side. This inversion allows the lock device to be positioned such that it can hold the door in a fully open state without being interfered with by the support body's protruding portions, thereby resolving the conflict between door holding capability and adaptability to different support body sizes.
Solution Approach 2:
A lock device is introduced as an intermediary mechanism between the door and the support body. This lock device acts as a mediator to hold the door in the fully open state, preventing direct contact and interference between the door and the support body, thus enabling the cabin to be used across different support body sizes.
2Adaptability or versatility
If custom cabins are manufactured for each type of work machine with different-sized support bodies, then door opening compatibility is achieved, but cabin manufacturing cost increases
Solution Approach 1:
The cabin is designed with universal applicability to multiple types of work machines with different-sized support bodies. By relocating the lock device to the support body side, the same cabin design can be used across different machine types, eliminating the need for custom cabins for each support body size and thereby reducing manufacturing costs.
Solution Approach 2:
The locking function is separated from the cabin structure and assigned to the support body side. This segmentation allows the cabin to be standardized and reused across different machine types, while the support body is customized to include the appropriate lock device positioning, thus reducing overall system cost.
3Object-affected harmful factors
If a chamfered portion is provided on the engine cover to prevent contact with the door, then door hitting is prevented, but processing and forming the chamfered portion for each support body increases manufacturing complexity
Solution Approach 1:
The conflict prevention function is extracted from the support body structure (by removing the need for chamfered portions) and transferred to a dedicated lock device. This eliminates the need for complex processing of the support body for each machine type, while still preventing door contact with the support body through the locking mechanism.
Data Source
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AI summary
[Problem] To provide a work machine capable of preventing fluttering of a door in a fully open state and reducing a manufacturing cost of a cabin by enabling the cabin to be used in common for support bodies different in size. [Solution] A hydraulic excavator as a work machine includes a cabin that covers a driver's seat and a support body that supports the cabin. The cabin has a center pillar that extends in an up-down direction and a door that is rotatably supported by the center pillar in such a manner to be opened forward. The support body has a lock device that holds the door when the door is in a fully open state.