LY/T 1934-2010Garden machinery Mounted lawn trimmer powered by gasoline (diesel) engine (English PDF)

6.2.1 Requirements

The performance of the diesel engine for the mounted lawn mower should meet the requirements of GB/T 1147.1.

The performance of the gasoline engine matched with the mounted lawn mower should meet the requirements of JB/T 5135.1.

6.2.2 Inspection

The performance test of the diesel engine is carried out in accordance with the provisions of GB/T 1147.2.

The performance test of the gasoline engine is carried out in accordance with the regulations of JB/T 5135.2 and JB/T 5135.3.

Overall performance

6.3.1 Mowing height and gear

6.3.1.1 Requirements

Mounted lawn mowers should have at least 3 mowing height gears, and should be easy to adjust; the actual mowing height measurement at any cutting position the deviation between the value and the given value in the manual should be within ±5 mm.

6.3.1.2 Inspection

By controlling the shift mechanism, check whether the clutch of each gear is flexible and reliable. When checking the height of the mowing, place the mounted lawn mower on a level ground on the surface, adjust to each cutting gear according to the method given in the manual, and measure (with an accuracy of ±0.5 mm) the tip of the knife at each cutting position.

For the distance from the ground, take the minimum value measured as the mowing height value, and calculate whether the deviation is within the set range.

6.3.2 Maximum no-load speed of the tool

6.3.2.1 Requirements

In the no-load state of the mounted lawn mower, the measured maximum no-load speed of the tool should be within the range of 95% to 110% of its calibration value.

6.3.2.2 Inspection

Combine the pruning tool, the mounted lawn mower runs stably at the maximum no-load speed of the tool in situ, and the speed of the tool is directly measured by the tachometer (Allowable measurement error ±10 r/min); for machines where the tool is directly connected to the engine output shaft, it can also be measured by the engine spindle the speed method indirectly measures the maximum no-load speed of the tool.

6.3.3 Grass gathering performance

6.3.3.1 Requirements

For mount lawn mowers with grass collectors, the amount of fragments that can be collected in the grass collectors should not be less than 80% of the nominal volume of the grass collectors, that is, the grass catching rate should not be less than 80%.

6.3.3.2 Inspection

6.3.3.2.1 Test lawn

Choose warm-season obtuse-leaf grass or cold-season perennial ryegrass as the test lawn. The height of the grass is greater than 60 mm.

The rain has not been sprinkled.

6.3.3.2.2 Site preparation

The mowing height of the mounted lawn mower is set to the gear closest to 60 mm, and the commissioning is completed according to the regulations of the manual, and the grass collector is installed.

Cut out a large enough lawn to be tested in the test site. If the grass height of the lawn to be tested is 60 mm ± 5 mm, the test can be carried out directly.

6.3.3.2.3 The actual grass collecting quality measurement of the grass collector Remove the broken grass on the surface of the lawn to be tested before the test.

The mowing height of the mounted lawn mower is set to the gear closest to 30 mm, and the grass collector is installed according to the instructions. The lawn is to be tested.

Perform normal pruning until the grass collector cannot collect grass. Stop the rotation of the cutting tool and fix the mount lawn mower in a horizontal state, Remove the grass collector and collect the scraps of grass collected in the grass collector. Repeat the test three times or use three machines of the same specification to test each time. respectively Weigh the mass of the grass collected in the three trials (allowable measurement error ±1%), and take the arithmetic average of the three trials as the actual grass collector quality.

6.3.3.2.4 Nominal volume of grass collector

In addition, prepare a grass collector with the same volume as the manufacturer's instructions (allowable error ±0.5%), and its diameter and height are the same.

For standard cylindrical containers with a tolerance of ±10%, the pieces cut from the three tests in 6.3.3.2.3 shall be broken without applying external force.

Fill the standard container with grass, weigh the mass of the grass collected in the container, repeat three times, and take the arithmetic average of the three times as the nominal volume of the grass collector Collect grass quality.

6.3.3.2.5 Sloppy

The sloppy rate is calculated according to formula (1).

eta-grass collection rate, %;

m1--the actual mass of grass collected by the grass collector, in grams (g);

m2-the nominal volume of the grass collector, the mass of the grass, the unit is grams (g).

Note. In the case of a certain grass collection density, the grass collection volume percentage is equal to the grass collection mass percentage, so the grass collection mass percentage is used instead of the grass collection volume percentage.

6.3.4 Maximum travel speed

6.3.4.1 Requirements

The actual measured value of the maximum travel speed of the mounted lawn mower should be within the range of 95% to 105% of its calibration value.

6.3.4.2 Inspection

6.3.4.2.1 Test conditions

The test conditions for the maximum travel speed are as follows.

a) Test on a pavement (or other similar test surface) with a strong, dry, smooth, and hard concrete level (gradient not exceeding 1%) get on.

b) The distance of the test interval is 100 m, and the allowable deviation range is controlled within ±0.5%. At both ends of this test interval, there are sufficiently long Auxiliary driving section to ensure that the machine's driving speed can reach its maximum driving speed before reaching the measurement start point.

c) Mounted lawn mower has all the devices installed according to the regulations of the manual, and the debugging is completed.

d) The weight of the operator is (75±5) kg.

e) The test environment conditions should meet the following requirements.

1) Atmospheric pressure is not less than 97 kPa;

2) The temperature is not less than 5 °C;

3) The relative humidity is not more than 95%;

4) The wind speed is not more than 3 m/s.

e) The measurement tolerances are as follows.

1) Driving speed. ±3%;

2) Tire inflation pressure. ±5%;

3) Time. ±0.1 s.

f) Number of measurements. One round trip counts as one time.

g) If the test result does not satisfy that the difference between the round-trip speed is less than 5%, then repeat...