The structure, working principle and usage precautions of the bidirectional side unloading device for loaders

The structure, working principle and usage precautions of the bidirectional side unloading device

The bidirectional side unloading device is a multi-functional new type of machinery configured at the front end of the loader, which can unload materials in the forward direction as well as to the left and right sides. In addition to the functions of a common loader's working device, it is particularly suitable for tunnel excavation and construction in relatively narrow and small sites. It can also operate in parallel with the matching transport vehicles without the need for turning or U-turning and other control actions, reducing the operation cycle time and improving work efficiency. It is an ideal deformation operation tool for earthwork and long tunnel construction. Compared with the working device of the ordinary loader, in the design, manufacture and assembly, it is only necessary to modify the two-part hydraulic system and its distribution valve of the ordinary loader to a three-part one, then replace the normal bucket with a bracket and side unloading bucket assembly, and then configure and connect the side unloading hydraulic cylinder and its pipelines and other accessories. Although the manufacturing and assembly difficulty has increased, the manufacturing cost has also slightly increased. However, stronger domestic and foreign shovel and transportation companies are still willing to develop and manufacture a series of tonnage bidirectional side unloading devices to improve the utilization rate of the main body of the loader and the economic operation. Due to the significant differences in its structural composition and working principle from the working devices of ordinary loaders, the following is a brief introduction to the basic structure, working principle and operation and usage precautions of this device.

1. Structural composition

The bidirectional side-unloading working device, like the common working device of a loader, is of the front-moving type. However, due to an additional pipeline in its hydraulic system, the front frame of the side-unloading loader needs to be slightly modified in design. Its three-dimensional shape structure is shown in Figure 1.

As can be seen from the above figure, the side-unloading working device (bidirectional) is composed of the side-unloading bucket assembly (including the teeth of the bucket or the replaceable tooth seat sleeve), the bracket assembly, the side-flipping hydraulic cylinder and its flexible and rigid pipe accessories, the hinge pin shaft and other components. Among them, the bracket assembly 5 is hinged to the loading boom assembly through the pull rod hinge pin 7 and the boom hinge pin 8. The side-unloading bucket welded joint 3 is fixedly connected to the bracket assembly 5 through the hinged pins 4 at both ends (the forward unloading pin shaft or the side unloading pin shaft can be selected according to the user's requirements for the forward unloading or side unloading working conditions). The upper end of the side-unloading hydraulic cylinder hinge pin 9 is hinged to point A of the bucket 3, and then the lower end of the side-unloading hydraulic cylinder hinge pin 11 is hinged to point B or C of the bracket assembly 5 (depending on the user's usage requirements). Finally, install the necessary connecting accessories, and an organic moving whole is assembled, thereby achieving the two functions of left and right bidirectional side-unloading and forward unloading. When in the normal unloading state, the wedge at position E on the bracket assembly 5 is closely attached to the wedge sleeve at position D on the bucket welded joint 3 to enhance its force-bearing strength and prevent severe deformation of the entire device under the harsh condition of overload. In addition, the "V" -shaped block at the upper F of the bucket welded joint 3 can also be well attached to the lower steel pipe in the bracket assembly 5 to enhance the anti-twisting deformation capacity of the device under the forward unloading condition, ensuring the safety and reliability of the entire device. The final side-discharge bucket assembly can be designed as a common reinforced side-discharge bucket or a rock-specific "V" -shaped blade bucket based on the user's usage environment and specific working conditions.

2 The working principle of the bidirectional side unloading device

2.1 Principle of the Motion Mechanism of the Bidirectional Side Unloading Device:

The schematic diagram of the side unloading condition of the bidirectional side unloading working device is shown in Figure 2 (the figure shows the unloading condition to the right). Its main components include the side unloading bucket assembly, the bracket assembly and the side unloading cylinder, etc. The bracket assembly is hinged to the boom and pull rod, and is integrated with the side unloading bucket assembly through the side unloading or stop unloading pin shaft. The side unloading hydraulic cylinder is installed on the back of the side unloading bucket. Its front fulcrum is hinged to the side unloading bucket assembly, and its rear fulcrum is hinged to the bracket assembly. Under the repeated extension and retraction of the piston rod of the side unloading hydraulic cylinder, the side unloading bucket assembly can rotate laterally back and forth around the side unloading pin shaft, thereby achieving the lateral unloading function. When unloading from the left (right) side, only the rear support point of the side-unloading hydraulic cylinder needs to be hinged to the shaft seat hole on the left (right) side of the bracket assembly with the hinge pin shaft, and the corresponding left (right) side hinge seat of the side-unloading bucket assembly and the hinge hole of the bracket assembly need to be fixed with the side unloading pin shaft. When the user needs this device to perform forward unloading operations, they only need to lock the side unloading hydraulic cylinder (at this time, the driver can move the side unloading control lever to the middle position), and then hinged the hinge hole on the other side of the side unloading bucket assembly and the bracket assembly with a forward unloading pin shaft, making the bucket and the bracket a rigid whole, thereby achieving the same forward unloading operation function as a common bucket.

2.2 Working Principle of the Hydraulic System of the Bidirectional side unloading device:

The hydraulic system principle of the bidirectional side-discharge working device is shown in Figure 3. The pressure oil output by the combined flow of the working pump and the steering pump enters the front and rear chambers of the side-discharge hydraulic cylinder through the three-way hydraulic control multi-way valve (model D32.3) as the power source for the operation of the side-discharge device. When the driver pushes the side unloading control lever forward, high-pressure oil enters the rod-free chamber of the side unloading hydraulic cylinder. Meanwhile, the low-pressure oil in the rod-free chamber of the side unloading hydraulic cylinder is discharged back to the oil tank through the three-way hydraulic control multi-way valve and the hydraulic oil radiator, causing the piston rod to extend and thus achieving the side unloading condition. Similarly, when the side unloading control lever is pulled backward, the piston rod of the side unloading hydraulic cylinder retracts, achieving the lateral bucket retraction action of the side unloading device. When the side unloading control lever is in the middle position, the valve core of the hydraulic control multi-way valve is locked, and the bucket is in the current forward unloading operation position.

3 Precautions for the operation, use and maintenance of the bidirectional side-discharge working device

Due to the specific structure and special operational nature of the bidirectional side unloading working device, especially when performing full-load side unloading operations, its safety is relatively reduced, and the design requirements for the performance parameters of the entire machine are higher. Therefore, stricter requirements are put forward for the operation and maintenance of users to reduce the degree of damage to the main machine. Here are a few brief examples of points to note:

3.1 If the user needs to change the side unloading direction of the side unloading device, the side unloading hydraulic cylinder can be replaced to the corresponding hinge position (refer to Figure 2 above), and attention should be paid to the direction of the oil port. When the side unloading bucket is hinged to the bracket assembly, the gap must be appropriately adjusted with an adjusting gasket, and then the side unloading hinge pin shaft should be installed. It is necessary to ensure that the side unloading hydraulic cylinder moves in the same plane as much as possible.

3.2 If a forward unloading operation is required, the user must install a forward unloading pin shaft (included with the random accessories). The forward unloading pin shaft is only used in conjunction with the side unloading pin shaft during the forward unloading operation. During the forward unloading operation, it is strictly forbidden to use a single side unloading pin shaft for the forward unloading operation, nor should the forward unloading pin shaft be used as a hinged pin during the side unloading operation to avoid damaging the entire side unloading device.

3.3 Under normal working conditions, the operator should ensure that the boom is raised to the highest position as much as possible before performing side unloading operations. If restricted by the construction site (such as tunnels following the tunnel, etc.), the position for side unloading operations should also be raised as much as possible. It is strictly prohibited to perform side unloading operations when the lower hinge point of the boom is less than 1 meter above the ground to prevent damage to the side unloading bucket.

3.4 Due to the particularity of the full-load side unloading operation conditions, it is strictly prohibited for drivers to carry out side unloading operations on sites with lateral ramps, nor when there is a certain bending and turning Angle. This is of great significance for ensuring the safety of the machine and personnel. Operators must keep this in mind carefully.

3.5 When conducting short-distance transportation operations, the side unloading device must not be lifted to the highest position to transport materials. During the transportation of materials, the lower hinge point of the boom should be kept at a transportation position approximately 400mm above the ground to ensure the stable operation of the main machine.

3.6 Before conducting side-unloading operations, the operator should ensure that the tire pressure on the side-unloading side is not lower than that on the non-side-unloading side.

3.7 Finally, before using this machine, clean grease must be injected into each hinge of the side unloading working device to ensure adequate lubrication and guarantee the long service life of the side unloading device.