The basic operation process of a loader is loading, transferring, unloading, and returning. Different operation methods should be selected according to different construction objects. Below is an introduction to the application skills of loaders in highway engineering.
1. Loading loose materials such as crushed stone and sand
In highway engineering, currently, loaders are mainly used to shovel and load various loose materials such as gravel and sand in the mixing plant. A straight toothed bucket should be used for shovel loading. Quality buckets and other accessories are required to recognize the grand view of intelligent manufacturing. First, place the bucket at the bottom of the pile, with the bucket mouth facing forward, the machine moving forward at low speed, and the bucket teeth inserted into the pile. If the shovel loading resistance is large, the boom can be manipulated to make the hopper vibrate up and down, which can reduce the friction resistance between the materials and accelerate the speed of material feeding until the hopper is full; Then retract the bucket with the bucket mouth facing upward, use the boom to lift the bucket to a transfer position about 50 cm from the ground, and the machine will reverse and turn to the unloading location.
2. Soil below the shovel loading surface
In highway engineering, loaders can be used to peel off topsoil. At this time, loaders should use straight blade buckets, similar to bulldozer operations. During shovel loading, first lower the bucket and rotate it to form a certain shovel angle (10-30 °) with the ground. The shovel angle can be larger for Grade I and II soil, larger for Grade III and above soil, and smaller for Grade III and above soil; Then, the machine moves forward in gear I, allowing the blade to cut into the soil, with the cutting depth generally maintained at about 15-20 cm. For difficult to shovel soil, in order to reduce the resistance of shovel loading, the boom can be manipulated to make the bucket vibrate up and down or slightly change the shovel angle until the bucket is full; Collect the bucket after filling it with material. Lift the bucket to the transportation position, drive away from the working surface, and transport to the unloading location. This method is also commonly used for collecting river sand and for leveling the work site.
3. Shovel loaded soil pile
Currently, stone mixed stabilized soil is often used in the construction of lime flyash soil base. When mixing stabilized soil, a loader can be used to load the soil pile. During shovel loading, the following three different methods can be used based on the accumulation of soil and the differences in the technical water used by drivers.
(1) Layered shovel loading method
Lower the bucket close to the bottom of the slope, face the soil pile, and advance at low speed; When the bucket is inserted into the soil pile to a certain depth, cooperate with the boom to lift the bucket; After the bucket teeth have left the mound, turn the bucket to the transport position. Due to the lack of deep insertion and the coordination of lifting actions after insertion, this method of operation has low insertion resistance and relatively stable operation. In addition, due to the longer loading surface, a higher filling coefficient can be obtained. Due to its characteristics, it is similar to the operation method of a front shovel excavator. Therefore, it is also known as the excavator shovel loading method.
(2) Segmented shovel loading method
During operation, tilt the bucket forward slightly and insert it from the bottom of the slope. After inserting it to a certain depth, lift the bucket. When the engine speed decreases, cut off the clutch to restore the engine speed; During the recovery of rotational speed, the bucket will continue to rise and load a portion of soil; After the rotational speed is restored, proceed to the second insertion. Repeat this process until the bucket is filled or raised above the working surface. Sometimes, after filling the bucket, the bucket is still slightly pushed into the working surface to loosen the soil to facilitate the next shovel loading. This method is suitable for occasions with hard soil. Its characteristics are that it can always maintain the engine operating at rated operating conditions, improve the operating ability, and rely on the bucket to successively insert and lift operations, which is relatively complex. The driver is prone to fatigue, and the clutch is prone to wear.
(3) Matching shovel loading method
Firstly, lower the bucket to the bottom of the slope, and while the loader is advancing, cooperate with the action of rotating the bucket or lifting the boom to carry out the shovel loading operation. That is, when the bucket is inserted into the material pile at a depth of about 0.2-0.5 bucket, while the loader is advancing, intermittently operate the bucket to turn up, and cooperate with the boom to lift until the bucket is full; After the bucket teeth have left the mound, turn the bucket to the transport position. Using a matching shovel loading method, the bucket does not need to be inserted very deeply. The combination of insertion motion, bucket tooth rotation, and lifting motion greatly reduces insertion resistance and makes the bucket easy to fill; However, the driver is required to have a high level of operation.
During the operation of the above three types, it is necessary to pay attention to the cleaning of the cohesive soil inside and outside the bucket at any time, otherwise it will not affect its effective capacity, and will also increase the resistance of the operation.
4. Clean up the earth and rock at the blasting site
In subgrade earthwork blasting engineering, loaders (or excavators) are commonly used to clean up the blasting site. When using a loader for cleaning, it is advisable to replace a V-shaped toothed bucket to improve its loading and digging capabilities. During cleaning, the particle size of crushed stone after blasting cannot exceed the allowable capacity of the bucket, and if it exceeds the allowable capacity, it is necessary to blast the stone again. In addition, when the cleaning distance is within 40-100m, the loader can shovel and transport itself. When the transportation distance exceeds 100m, it is necessary to cooperate with a dump truck. After cleaning, the loader should be transferred and parked outside the blasting warning line to ensure the safety of the human machine.
5. Lifting various working tools and equipment
In the construction site of highway engineering, if there is no dedicated lifting equipment, loaders can be used to lift various working tools and equipment. For example, when it is necessary to repair or assemble a construction machine at the construction site, the loader can operate as a lifting device for disassembling and assembling various components. The official account Smart Manufacturing Grand View focuses on the sharing of relevant theoretical knowledge in the construction machinery manufacturing industry. When using the loader as a lifting device, the lifting load must be bound firmly, and the wire rope or hook must be hung between the bucket teeth of the loader. The center of the load must be at the same vertical position with the center of the bucket. During operation, special personnel shall be assigned to command, and the driver shall carefully operate. During lifting, the bucket shall be retracted first, and then the boom shall be slowly lifted. During assembly, it shall be handled slowly and gently; At the same time, the lifting capacity of the loader should be greater than the weight of the lifted object to ensure the safety and reliability of the lifting and prevent damage to personnel and mechanical equipment.
