1.1 This standard specifies, in accordance with GB/T 18707.1, a laboratory method for measuring and evaluating the effectiveness of the seat suspension in reducing the vertical whole-body vibration transmitted to the operator of earth-moving machines at frequencies between 1~20Hz. It also specifies acceptance criteria for application to seats on different machines.
1.2 This Standard is applicable to operator seats used on earth-moving machines as defined in GB/T 8498.
1.3 This standard defines the input spectral classes required for the following earth-moving machines. Each class defines a group of machines having similar vibration characteristics:
- Rigid frame dumpers>4500kg operating mass ;
- articulated frame dumpers;
- scrapers without axle or frame suspension ;
- wheel-loaders>4500kg operating mass1;
- graders;
- wheel-dozers;
- soil compactors (wheel type);
- backhoe-loaders;
- crawler loaders;
- crawler-dozers ≤50000kg operating mass1;
- compact dumpers≤4500kg operating mass1;
- compact loaders≤4500kg operating mass1;
- skid-steer loaders≤4500kg operating mass1.
1.4 The following machines impart sufficiently low vertical vibration inputs at frequencies between 1~20Hz to the seat during operation that these seats do not require suspension for the attenuation of transmitted vibration:
- excavators, including walking excavators and cable excavators ;
- trenchers;
- landfill compactors;
- non-vibratory rollers;
- milling machines;
- pipelayers;
- finishers;
- vibratory rollers;
1.5 The tests and criteria defined in this standard are intended for operator seats used in earth- moving machines of conventional design.
Note: other tests may be appropriate for machines with design features that result in significantly different vibration characteristics.
1.6 Vibration which reaches the operator other than through his seat, for example that sensed by his feet on the platform or control pedals or by his hands on the steering-wheel, is not covered.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding amending errors in the text), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of the normative document is applicable. For undated references, the latest edition of the normative document applies.
GB/T 2298 Mechanical Vibration and Shock - Terminology (GB/T 2298-1991, neq ISO 2041:1990)
GB/T 8498 Earth-moving Machinery - Basic Types - Vocabulary (GB/T 8498-1999, eqv ISO 6165:1997)
