ISO 7096:2000 pdf download

ISO 7096:2000 pdf download.Earth-moving machinery – Laboratory evaluation of operator seat vibration.
A platform, the dimensions of which correspond approximately to those of the operator’s platform of an earth- moving machine, shall be mounted on a vibrator which is capable of generating vibration along the vertical axis (see Figure 1).
NOTE In the case of classes EM 1 and EM 2 the vibrator should be capable of simulating sinusoidal vibration having a displacement amplitude of at least ± 7,5 cm at a frequency of 2 Hz; see 5.4.1.
5.2 Test seat
The operator seat for the test shall be representative of series-produced models, with regard to construction, static and vibration characteristics and other features which may affect the vibration test result. Before the test, the suspension seats shall be run-in under conditions stipulated by the manufacturer. If the manufacturer does not state such conditions, then the seat shall be run-in for 5 000 cycles, with measurements at 1 000 cycle intervals.
For this purpose, the seat shall be loaded with an inert mass of 75 kg and adjusted to the mass in accordance with the manufacturer’s instructions. The seat and suspension shall be mounted on the platform of a vibrator, and a sinusoidal input vibration shall be applied to the platform at approximately the suspension natural frequency. This input vibration shall have a peak to peak displacement sufficient to cause movement of the seat suspension over approximately 75 % of its stroke. A platform peak to peak displacement of approximately 40 % of the seat suspension stroke is likely to achieve this. Care should be taken to ensure against overheating of the suspension damper during the running-in, for which forced cooling is acceptable.
The seat shall be considered to have been run-in if the value for the vertical transmissibility remains within a tolerance of ± 5 % when three successive measurements are performed under the condition described above. The time interval between two measurements shall be half an hour, or 1 000 cycles (whichever is less), with the seat being constantly run-in.
The seat shall be adjusted to the weight of the test person in accordance with the manufacturer’s instructions.
With seats where the suspension stroke available is unaffected by the adjustment for seat height or test person weight, testing shall be performed with the seat adjusted to the centre of the stroke.
With seats where the suspension stroke available is affected by the adjustment of the seat height or by test person weight, testing shall be performed in the lowest position which provides the full working suspension stroke as specified by the seat manufacturer.
When the inclination of the backrest is adjustable, it shall be set approximately upright, inclined slightly backwards (approximately 100 ± 5°).
5.3 Test person and posture
The simulated input vibration test shall be performed with two persons. The light person shall have a total mass of
52 kg to 55 kg, of which not more than 5 kg may be carried in a belt around the waist. The heavy person shall have
a total mass of 98 kg to 103 kg, of which not more than 8 kg may be carried in a belt around the waist.
Each person shall adopt a natural upright position on the seat and maintain this position throughout the test (see Figure 1).
Differences in the posture of the test person can cause a 10 % difference between test results. For this reason, recommended angles of knees and ankles have been specified in Figure 1.
5.4 Input vibration
5.4.1 Simulated input vibration test to evaluate the SEAT factor
This International Standard specifies the input vibration in nine input spectral classes (EM 1 through EM 9) for earth-moving machinery for the purpose of determining the SEAT factor.
The input vibration shall be determined (calculated) without components at frequencies outside the frequency range defined byJ1 andf2.
Table 4 further defines the test input values for the actual test input PSD at the base of the seat.
Three tests shall be performed for each test person and each input vibration in accordance with ISO 10326-1:1992,
9.1. The effective duration of each test shall be at least 180 S.
If none of the SEAT values relating to one particular test configuration deviate by more than ± 5 % from the arithmetic mean, then, in terms of repeatability, the three tests mentioned above shall be deemed to be valid. If this is not the case, as many series of three tests as are necessary to satisfy this requirement shall be carried out.
The sampling time T and resolution bandwidth Be, shall satisfy the following.