Detection and use of old construction machinery to delay the aging of equipment

After being used for a period of time, bulldozers, loaders, excavators and truck cranes often experience a decline in the sensitivity of the operating mechanism and slow movement of the working mechanism.

1. Phenomenon

The engine exhaust, operation and sound are all abnormal. It is difficult to start and the acceleration is slow. The oil in the hydraulic system is contaminated. The external and internal oil leakage of hydraulic components, pipelines and joints is severe. The hydraulic cylinder cannot be locked and automatically retracts. The transmission chains of all the control handles of the entire machine are loose, causing obstruction and difficulty during operation.

2 Reason

The main issues are prolonged overwork and operating in environments that do not meet the requirements. Daily maintenance is not timely, and major, medium and minor repairs fail to meet the standard requirements.

3 Measures

(1) Strictly manage and continuously improve the technical quality of operators to ensure the correct use of construction machinery.

(2) Strengthen the daily maintenance and inspection of equipment to improve its integrity rate.

(3) Enhance the technical proficiency and sense of responsibility of maintenance personnel to ensure the quality of major, medium and minor repairs. Appropriately increase dedicated maintenance equipment, tools, instruments and technical data.

(4) Adjust and repair the machinery

4 Adjustment and repair methods

Adjustment of the engine throttle

For instance, the diesel engine installed on a truck crane, after long-term use, sometimes shows a slow acceleration when operating the throttle on the vehicle, failing to reach the maximum speed and maximum power. At this point, it is necessary to inspect and adjust the entire transmission chain of the foot pedal on the vehicle. This job requires two people. One person gets on the vehicle and operates the accelerator pedal, while the other observes the movement of the speed control lever at the fuel injection pump. Although the operator in the cab of a crane that has been in use for many years has pushed the accelerator pedal to the limit position, in reality, the speed control lever of the diesel fuel injection pump sometimes still cannot reach the limit position. Because the speed control lever is located in a part of the entire machine that is not easily observable by the operator, its idle stroke is often overlooked. Therefore, it is necessary to observe it for a longer time and try it several times. The reasons for this situation are, first, the dimensional chain of the transmission system of the diesel engine throttle has changed, resulting in excessive accumulation of idle travel in the middle. The second reason is that some fasteners on the transmission devices, such as set screws, are loose. At this point, the throttle transmission dimension chain should be checked step by step. When the throttle is fully depressed on the vehicle, the speed control lever must also reach the limit. The clearance on the throttle transmission chain should be retained as required and tightened and adjusted according to the specific conditions of each piece of equipment.

After being used for a period of time, bulldozers, loaders, excavators and truck cranes often experience a decline in the sensitivity of the operating mechanism and slow movement of the working mechanism.

1. Phenomenon

The engine exhaust, operation and sound are all abnormal. It is difficult to start and the acceleration is slow. The oil in the hydraulic system is contaminated. The external and internal oil leakage of hydraulic components, pipelines and joints is severe. The hydraulic cylinder cannot be locked and automatically retracts. The transmission chains of all the control handles of the entire machine are loose, causing obstruction and difficulty during operation.

2 Reason

The main issues are prolonged overwork and operating in environments that do not meet the requirements. Daily maintenance is not timely, and major, medium and minor repairs fail to meet the standard requirements.

3 Measures

(1) Strictly manage and continuously improve the technical quality of operators to ensure the correct use of construction machinery.

(2) Strengthen the daily maintenance and inspection of equipment to improve its integrity rate.

(3) Enhance the technical proficiency and sense of responsibility of maintenance personnel to ensure the quality of major, medium and minor repairs. Appropriately increase dedicated maintenance equipment, tools, instruments and technical data.

(4) Adjust and repair the machinery

4 Adjustment and repair methods

Adjustment of the engine throttle

For instance, the diesel engine installed on a truck crane, after long-term use, sometimes shows a slow acceleration when operating the throttle on the vehicle, failing to reach the maximum speed and maximum power. At this point, it is necessary to inspect and adjust the entire transmission chain of the foot pedal on the vehicle. This job requires two people. One person gets on the vehicle and operates the accelerator pedal, while the other observes the movement of the speed control lever at the fuel injection pump. Although the operator in the cab of a crane that has been in use for many years has pushed the accelerator pedal to the limit position, in reality, the speed control lever of the diesel fuel injection pump sometimes still cannot reach the limit position. Because the speed control lever is located in a part of the entire machine that is not easily observable by the operator, its idle stroke is often overlooked. Therefore, it is necessary to observe it for a longer time and try it several times. The reasons for this situation are, first, the dimensional chain of the transmission system of the diesel engine throttle has changed, resulting in excessive accumulation of idle travel in the middle. The second reason is that some fasteners on the transmission devices, such as set screws, are loose. At this point, the throttle transmission dimension chain should be checked step by step. When the throttle is fully depressed on the vehicle, the speed control lever must also reach the limit. The clearance on the throttle transmission chain should be retained as required and tightened and adjusted according to the specific conditions of each piece of equipment.