YANMAR Technical Review

Abstract

Yanmar's ViO series of excavators are now in their 6th generation. Features of the latest models include an LCD monitor, ECO mode, automatic deceleration, external engine shut-off, and a one-touch (tool-less) engine cover opening mechanism. The newly developed ViO20-6 retains the best features of previous models together with technologies developed for the 6th generation with unified form and function. Designed to be more economical and easier to operate and maintain, the ViO20-6 is also the first Yanmar excavator in the 2-ton class to offer a variable undercarriage option (previously a feature of 1.7-ton and smaller models). With its 6th generation technologies and variable undercarriage option, the ViO20-6 represents a new initiative for Yanmar.

1. Introduction

Designed with zero tail swing (such that the rear of the rotating upper structure never extends outside the width of the crawlers), a feature that ensures a high level of safety, the ViO series is the largest range of hydraulic excavators made by Yanmar Construction Equipment. The ViO series is currently in its 6th generation, with standard features on the latest models including an LCD monitor, ECO mode, automatic deceleration, external engine shut-off, and an engine cover with a one-touch (tool-less) opening mechanism. The new ViO20 forms part of this 6th generation and has undergone a full model change, the first since the 3rd generation model 14 years ago. The model change retains the best features of previous models while also incorporating the technologies developed for the 6th generation models, resulting in a compact machine that is designed to be more economical and easier to operate and maintain. It is a product that incorporates high-end design concepts throughout in terms of both form and function. Along with the model change, the ViO20 is also the first Yanmar model in this class to offer a variable undercarriage option. Although a variable undercarriage mechanism is available on the ViO17 and below models, a new variable undercarriage concept has been incorporated into the ViO20. This report describes the ViO20 excavator, which represents a new initiative for Yanmar, featuring a mix of high-end and entry-level technologies.

2. Product Overview

Although targeted primarily at the Japanese and South Korean markets, the ViO20 excavator is a global product that is also sold in the rest of Asia, South America, and Australia. The fixed undercarriage option is designed with the same undercarriage width as the 3rd generation models to allow for ease of transportation, and also features high-end functions that include ECO mode, automatic deceleration, and an LCD monitor. The control panel is also the same as high-end models and is significantly different from that on the 3rd generation models. The variable undercarriage option meanwhile, was designed with lifting capacity and undercarriage width in mind, based on a concept of ensuring stable operation, including when fitting attachments. The undercarriage width can be adjusted in the range of 1380 mm to 1550 mm (the same as the higher-end ViO30 and ViO35 models) to ensure the stability of excavator operation when working with heavy attachments or when working on unstable ground. The ViO20 also reduces operator stress, being designed with zero tail swing (meaning the rear of the rotating upper structure never extends outside the width of the crawlers) when the undercarriage is extended, even when counterweights are attached.

3. Features

3.1. Variable Undercarriage

Comparisons were performed to assess the stability of the ViO20-6 with the undercarriage at its narrowest and widest positions, and at its widest position with counterweights fitted. For the configurations shown below, the lifting capacity for the wide-undercarriage configuration is 23% higher than that of the narrow-undercarriage configuration, while that of the wide-undercarriage-with-counterweights configuration is 38% higher. These configurations not only increase lifting capacity, they also significantly reduce the amount of sway experienced by the operator.

3.2. Economics

ECO mode and automatic deceleration mode have been added as standard features to improve the operational efficiency (economics) of the excavator. Turning on ECO mode slows the engine by 300 RPM from high idling speed at the push of a button, improving fuel economy by about 20%. Similarly, engaging automatic deceleration mode eliminates unnecessary fuel consumption and noise when the machine is idling.

3.3. Ease of Operation

The blade has been made longer than before to make it easier to use the arm and blade to lift up asphalt when working on roads or at other urban worksites. The operation and movements of the machine have also been made more intuitive by shrinking the gap between the bucket and blade by 90 mm compared to previous models.

In response to customer demand for making it easier to work at night, LED lights have been fitted as a standard feature, the first time this has been done for 6th generation excavators. (Note, however, that this is not available in some overseas markets.) In consideration of the rotation of the upper structure, the illuminated area extends to the left and right also, while the brightness has also been adjusted to prevent the operator from being dazzled by over-illumination of particular areas. The lights are also controlled by a dual-position switch that includes the option of turning on the boom lights only, a feature provided in consideration of people working nearby. To make operation safe and stress-free when working at sites where there are height restrictions, or when using an attachment that could potentially collide with the body of the excavator, a boom height limit and arm retraction limit have been added as safety features to automatically halt the boom and arm at specified positions.

3.4. Ease of Maintenance

To facilitate maintenance of the radiator and other parts, the engine cover features a one-touch (tool-less) opening mechanism. Furthermore, one of the benefits of the LCD monitor is that it can provide information in the event of a fault, making it easier to detect faults early and identify where the problem lies. By enabling a timely response to any problems that occur, this keeps machine downtime to a minimum.

4. Conclusions

The new ViO20 excavator brings together all the features of the 6th generation product range, built using concurrent engineering with different areas working together and achieving QCT. It was developed based on Yanmar Construction Equipment's concept of "BEST PERFORMANCE BY YOUR SIDE" and the company is confident that it will find use with a wide variety of customers. In the future, Yanmar intends to continue delivering superior products, not only by listening to what our customers say, but also by actively seeking out what it is that customers need.

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The original technical report is written in Japanese.

This document was translated by Research & Development Management Division.