Hydraulic Lifting Arm End-of-Stroke Pressure Cutoff Control
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Solution Overview
Problem
Lifting machines with hydraulic actuators face issues such as excessive energy consumption, engine stalling, noise increase, and component wear due to maintaining movement commands beyond the actuator's end-stop, which prior control systems fail to address effectively.
Innovation Solution
A control system for hydraulic actuators that includes a control unit and position sensors to detect the end-of-stroke position, allowing a controlled delay before stopping hydraulic pressure supply, reducing energy waste and prolonging component life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a lifting machine uses a brake drum and brake shoe configuration with a single pivot point, then the structure is simple and easy to manufacture, but the brake shoe cannot maintain consistent contact pressure with the brake drum during rotation, leading to reduced braking reliability and increased wear
Solution Approach 1:
The brake shoe is divided into two separate brake shoes instead of one unified shoe. Each brake shoe independently contacts the brake drum at different locations, allowing each to maintain optimal contact pressure during rotation. This segmentation resolves the contradiction by improving braking reliability through consistent contact while keeping each individual shoe structurally simple.
2Stability of the object's composition
If the lifting machine uses a complex counterweight balancing mechanism with multiple moving parts, then the counterbalancing precision is improved, but the device complexity and maintenance difficulty increase significantly
Solution Approach 1:
A counterweight is provided that rotates with the brake drum, with its center of gravity positioned to create a counterbalancing moment against the brake shoe pressure. This simple counterweight mechanism achieves precise counterbalancing by matching the rotational motion of the brake drum, eliminating the need for complex multi-part balancing mechanisms while maintaining high precision.
Solution Approach 2:
The counterweight is integrated with the brake drum assembly, rotating together as a unified structure. This merging of the counterweight with the existing rotating component eliminates separate driving mechanisms and reduces overall device complexity while maintaining effective counterbalancing precision.
3Device complexity
If the lifting machine operates without a dust-proof cover, then the structure remains simple and ventilation is good, but dust and debris enter the brake mechanism causing accelerated wear and reduced reliability
Solution Approach 1:
A dust-proof cover is provided that encloses the brake mechanism. The cover acts as a protective barrier preventing dust and debris from entering the brake components, thereby reducing wear and improving reliability. The cover design maintains structural simplicity while effectively protecting the internal mechanism.
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
Reduces energy consumption, minimizes noise and vibration, and extends hydraulic system availability by intelligently managing hydraulic actuator movements at the end of stroke.
Implementation Method 1
a spring (13) arranged to apply a braking action to the rotating member (10) when the rotating member (10) rotates in a first rotational direction
Implementation Method 2
wear on the brake shoe (12) and the brake drum (11)
Implementation Method 3
a counterweight (20) arranged to counterbalance the spring (13)
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
The invention relates to a lifting machine (1) comprising: a main body (2), a handling arm (3), a hydraulic actuator configured to move the handling arm, a hydraulic power supply device, and; a control system comprising: a control unit (7) configured to receive a movement request signal and to control the hydraulic power supply device in response to the movement request signal and a position sensor (13, 14, 15) configured to transmit a position signal representative of a position of the hydraulic actuator to the control unit, wherein the control unit is further configured to detect an end-of-travel stop position of the hydraulic actuator according to the position signal and to control the hydraulic power supply device so as to stop the supply of pressure to the hydraulic actuator in response to the detection of the end-of-travel stop position.