Draglines are a fairly old type of excavator, still in the age of steam, not long after wire rope excavators were invented. Its characteristics are that the boom is long and there is no stick. The position and inclination of the bucket are controlled by the lifting wire and the pulling wire. The bucket cuts soil by gravity, which is suitable for excavating relatively soft materials below the stop surface.

The dragline is not flexible enough when loading the truck, the accuracy is not enough, and the efficiency is relatively low. This limits its application, and construction draglines are mainly used for underwater excavation. Larger draglines have found their place in open-pit mines, with extra-long booms that allow for a large working range and deep digging depth, ideal for overburden stripping in coal mines. In order to pursue efficiency. People make the dragline bigger and bigger, and the working weight increases so much that the crawler travel mechanism can't bear it. To this end, a step-by-step running mechanism is applied to the dragline to reduce weight.

1. The hydraulic system of the excavator consists of a total of 5 parts. 2. The energy device part. The device that converts mechanical energy into pressure energy of fluid generally refers to a hydraulic pump, if it is pneumatic, it is an air compressor, the power part; 3. Execution device part. A device that converts the pressure of a fluid into mechanical energy, generally referring to hydraulic cylinders and hydraulic motors; 4. Part of the control and adjustment device. Control and adjust the pressure, flow and flow direction of the fluid in the hydraulic system, such as relief valve, throttle valve, reversing valve, etc.; 5. Auxiliary device part. In addition to the above 3 items, such as fuel tank, filter, accumulator, etc.; 6. Transmission medium. A medium that transmits energy.

Recently, a excavator caught fire while working at the dam construction site in Wuzhu Village, Qiupu River, Chizhou, Anhui. After receiving the alarm, firefighting and rescue personnel quickly rushed to the scene. The firefighters who arrived discovered that the excavator was burning fiercely, and thick smoke was billowing at the scene. Based on the on-site situation, the firefighters laid water gun positions to deal with the fire, and soon the open fire was successfully extinguished. To prevent it from reigniting, firefighters used water guns to continuously cool the excavator. After the fire was extinguished, the excavator had already burned into an empty shell. Fortunately, the accident did not cause any casualties. After entering summer, the temperature gradually increases. Before working on excavators, it is necessary to conduct safety performance checks to avoid spontaneous combustion. The following knowledge about self ignition prevention should be familiar with: 1. Keep the vehicle body clean and free of oil stains, and eliminate dirt. 2- Regular inspection of various oil pipes is required. 3- Regular inspection of electrical circuits is required, and aging circuits should be replaced in a timely manner. 4- Operators should develop good personal habits. 5- Fire extinguishers should be readily available in the vehicle.

According to a research report released by Zhejiang Securities (601878), according to the statistics of the China Construction Machinery Industry Association on major excavator manufacturing enterprises, 18772 excavators of various types were sold in April 2023, of which 9513 were domestically produced; Export 9259 units. Domestic leading enterprises have significantly increased their overseas layout efforts in 2022, and there is still significant room for improvement compared to global leaders Caterpillar and Komatsu. Industry exports are expected to maintain a high growth rate throughout 2023, with a more prominent role in cycle smoothing. The future overseas market will be an important competitive market for Chinese enterprises and global leaders. Assuming a 5% decline in excavator sales in 2023, a slight decline in export growth, and a 30% increase in annual exports, it can hedge against a 30% decline in domestic sales. It is expected that excavator sales will bottom out in 2023. In April 2023, the sales of excavators decreased by 24% year-on-year; Among them, the domestic decline was 41%, while exports increased by 9%. In April 2023, the sales of excavators reached 18772 units, a year-on-year decrease of 24% and a decrease of 7.5 pct compared to March. Among them, 9513 units were sold domestically, a year-on-year decrease of 41% and a decrease of 7 units compared to March; Export 9259 units, a year-on-year increase of 9%, a decrease of 2 pct compared to March. From January to April 2023, the sales of excavators were 76243 units, a year-on-year decrease of 25%, including 38341 units in China, a year-on-year decrease of 44%; Export 37902 units, a year-on-year increase of 12%. The decline in domestic sales is mainly due to the weak repair of downstream demand, the slow recovery of operating rates, and the need to improve the market acceptance of the fourth model in China. Coupled with the slowdown in foreign growth, the overall sales of excavators are under pressure.