1. Cylinder operation time
Measurement purpose: measure the operating time of the boom, arm and bucket to determine the performance between the hydraulic pump and the cylinder of the accessory transmission system.
Measurement conditions: The temperature of the hydraulic oil is 45~55℃, the engine should be idling at high speed, and the operating time except the buffer stroke.
Preparation for measurement: Kobelco SK130 excavator should be parked on level ground and the bucket should be emptied.
Figure 2-24 shows the measurement positions of bucket excavation and dumping.
Measurement 1: Boom up and down. The measurement position is shown in Figure 2-25(a).
Drive the boom control lever to full stroke and measure the operating time required for the bucket to reach its highest position from the ground surface. When lowering the boom, allow the bucket to rest on soft ground or cushions such as rubber tires, and it is strictly forbidden to rest the bucket on concrete ground or other solid objects.
Measurement 2: Forearm contraction and extension, bucket digging and dumping. The measurement position is shown in Figure 2-25(b).
When the half tooth of the bucket is at a position of 30 cm from the ground, measure the full stroke operation time required when the arm and bucket control lever are at full stroke. The operation time of the cylinder is shown in Table 2-11.
2. The tightness of the cylinder
Purpose of measurement: To check whether the cylinder is leaking oil by checking the moving length of the piston rod.
Measurement conditions: The temperature of the hydraulic oil is 45~55℃. During the measurement, the excavator should be parked on a flat, level and solid ground.
[Note] After replacing the cylinder, let the air out of the cylinder immediately. This work should be completed before checking the tightness of the cylinder.
Preparation for measurement: Maintain the height of the bucket end 1.5m above the ground and empty the bucket to make the arm cylinder shrink to the maximum.
Measurement: The measurement should be started 5 minutes after the engine is stopped. Figure 2-26 shows the parking posture of the excavator during the measurement. The tightness of the cylinder is shown in Table 2-12.
