Wheel Loader Engine Speed Limiting During Raise-and-Run
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wheel loaders equipped with torque converter type travel drive systems, the high rate of increase in actual engine rotational speed during raise and run operations leads to increased travel speed and relatively low lift arm lifting speed, necessitating longer traveling distances and higher fuel consumption.
Innovation Solution
A wheel loader with a front working device, traveling state sensor, motion sensor, and controller that determines whether specific conditions for lift arm operation are met, and reduces the maximum engine rotational speed to limit vehicle speed during these operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional wheel loader is used, then it can perform basic loading operations, but it cannot effectively handle materials with high adhesion or abrasiveness due to lack of specialized bucket features
Solution Approach 1:
The bucket is equipped with specific local features (teeth, ribs, edges) at critical contact points to handle particular material challenges. These localized structural enhancements allow the bucket to adapt to high adhesion, abrasiveness, or impact conditions without requiring complete redesign of the entire bucket structure.
Solution Approach 2:
The bucket design allows for dynamic adjustment of its functional characteristics through the selective engagement of different features (teeth, ribs, edges) based on material conditions. The structure can effectively change its operational properties by utilizing different geometric elements suited to specific loading scenarios.
2Productivity
If the bucket operates in high adhesion conditions, then it can load sticky materials, but material accumulates on the bucket bottom reducing efficiency
Solution Approach 1:
V-shaped ribs are specifically positioned at the bottom of the bucket to create a geometric configuration that prevents material accumulation. This localized geometric feature addresses the adhesion problem at the critical bottom surface where material buildup would otherwise occur.
Solution Approach 2:
The design converts the potentially harmful adhesive property of materials into a beneficial gripping action. The V-shaped ribs and teeth leverage the adhesion of sticky materials to improve gripping action and loading efficiency, transforming the problem of material stickiness into an advantage for material handling.
3Productivity
If the bucket operates in high abrasiveness conditions, then it can handle abrasive materials, but the bucket structure wears down quickly
Solution Approach 1:
Wear-resistant teeth and reinforced edges are placed at specific high-wear locations (contact points with material) rather than throughout the entire bucket. This localized reinforcement provides abrasion resistance where it is most needed while maintaining overall bucket integrity and extending service life.
4Productivity
If the bucket operates in high impact conditions, then it can load heavy materials, but the bucket structure suffers damage
Solution Approach 1:
Reinforced edges and impact-resistant features are concentrated at the bucket's leading edge and contact points where impact forces are applied. This localized strengthening protects the bucket structure from damage during heavy material loading while avoiding unnecessary reinforcement throughout the entire bucket.
5Ease of manufacture
If conventional bucket design is used, then it has simple structure, but it lacks wear-resistant and cutting features needed for challenging materials
Solution Approach 1:
The bucket incorporates wear-resistant teeth, cutting edges, and reinforcing ribs only at critical locations where they are most needed for handling challenging materials. This approach maintains relative manufacturing simplicity while adding targeted features that significantly improve performance in high adhesion, abrasiveness, and impact conditions.
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
This solution reduces the traveling distance required for raise and run operations and decreases fuel consumption by controlling engine speed in accordance with lift arm motion, ensuring efficient operation and reduced fuel usage.
Implementation Method 1
a torque converter type travel drive system that transmits the drive force of an engine to wheels via a torque converter
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A wheel loader is provided that can reduce the traveling distance required for a raise and run operation, and reduce fuel consumption. A wheel loader 1 includes: an engine 3; a torque converter 41; a forward and reverse switch 62; a stepping amount sensor 610; an operation amount sensor 73; and a controller 5. The controller 5 determines whether a specific condition for specifying an operation of the lift arm 21 in an upper direction during forward travel of the vehicle body, on the basis of a forward and reverse switching signal, the stepping amount on the accelerator pedal 61, and a pilot pressure Ti pertaining to the lifting operation amount for the lift arm 21. When the specific condition is satisfied, the vehicle speed is limited by reducing the maximum rotational speed of the engine 3 in response to increase in the pilot pressure Ti.