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2020

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05

What problems should be paid attention to in the boom welding of wood grabber accessories


The small wood grabber arm is an important supporting member in the machine and equipment, and its welding quality is immediately related to the overall quality and characteristics of the excavator. The diesel engine is like the heart of the small wood grabber, so the boom is like an arm, moving The welding process of the arm means a company's technical strength and industry status. Because the small wood grabber arm must carry out a series of production and processing after welding, such as boring inner holes, milling inner holes, production and processing of mounting holes for sticks and hydraulic cylinders, and the production and processing requirements of this position are relatively high. , once there is a problem with welding, it is likely that other components cannot be installed, resulting in commodity billing and immediate property damage. Therefore, the welding process of the small excavator arm seems to be particularly important.

1. Problems that are very easy to appear in the welding of small wood grabbing motor arms

1. Welding deformation

The key reason is that the double-layer multi-channel high-current MAG welding is used for the fillet weld. During the welding, due to the welding ground stress, there will be a certain level of deformation on both sides of the boom, and a certain distortion will appear on the boom. If the wire hole or socket is deviated on the plan view, and the middle opening specification of the boom plate is deviated, once the deviation exceeds the specified value of its manufacturing standard, the product is a defective product.

2. Welding cracks

The key reason is that this type of wood grabber has more welding, including the left and right rear cover plates, the front and rear left and right baffle plates, the rear cover plate and the baffle plate, the baffle plate and the welding seam between the middle beam drum. It is closed type, so its rigidity is large, and the welding is concentrated. After each welding, there will be uneven temperature distribution, which will cause cracks caused by large internal stress during welding of stainless steel plates.

2. Control measures for welding quality of small wood grabbing motor arms

The key to the welding process of the boom welding of the small wood grabbing machine is to control the welding ground stress, so that the welding place has as little offset and internal stress as possible, so as to make the welding quality of the small wood grabbing machine arm more reliable.

1. Control measures for boom welding deformation

(1) Formulate an effective welding process

The welding process is immediately related to the welding quality of the small wood grabber arm. The quality of the product can only be guaranteed if a standardized production process is provided. The main parameters of the welding process are the control data information obtained after several tests, including welding The selection of welding method, welding sequence, welding position, starting welding position and closing welding position, and the welding process is not static, it needs to be changed with the specific conditions of material, thickness and welding position and welding gap, and the amount of welding current varies. The selection should be as small as possible, thereby reducing the thermal input, and the welding speed should be fast. When the thickness of the plate is too thick, the welding current should be increased as much as possible, but the current should be strictly controlled to reduce the thermal stress at the welding point. This reduces the generation of deformation.

(2) Select practical welding equipment

The whole process of small wood grabber arm welding is complicated with complicated machinery and equipment, and it is difficult to operate in practice. During welding, the orientation of the raw materials must be adjusted at all times to prevent the occurrence of welding blind spots. In addition, special attention should be paid to the entire welding process to avoid the appearance of objects to be welded. offset. Therefore, the key machinery and equipment for the welding of small wood grabber arms include lap welding service platform, welding positioner, welding fixture, etc. Among them, the lap welding service platform is also called tack welding, and its key function is to weld the board first. A frame shear wall is formed to improve its ability to resist welding deformation, and each component is reasonably welded; because the quality and appearance design of the small wood grabbing arm are relatively large, it is inconvenient to change the welding positioner during welding. direction, and it is very prone to blind spots, and the welding positioner can make the small wood grabbing boom change according to human factors during welding, so as to facilitate welding and improve the welding situation; the welding fixture is when welding, the boom components Not only must be positioned, but also must have sufficient clamping force to bear the force of the component and the stress of welding.

2. Auxiliary technology to avoid welding deformation of boom

(1) Reverse deformation welding technology

The anti-deformation method is to release a certain reverse force on the deformed position to offset the deformation stress. When choosing the anti-deformation method, it is necessary to first choose to measure the amount of shrinkage caused during the whole welding process, and then calculate the external release reaction based on it. The amount of deformation makes the two offset each other and reduces the deformation deviation at least. The key factors that endanger the vertical deformation of the welding are the length and cross-section of the welding piece.

(2) Select welding intelligent robot

As a popular technology in recent years, intelligent welding robots are widely used in the construction machinery and equipment industry. Because intelligent welding robots are controlled by the system, they implement a unified actual operation sequence in the whole welding process, so their welding quality can be maintained. Consistent, it is not easy to have different quality of goods due to human error.

(3) Laser welding technology

Laser welding is to focus the laser light together and point it to the welding site. According to the large kinetic energy, the welding site of the welding material is melted, and then welding is carried out. The bending stiffness after welding is significantly improved. At this stage, laser welding is mainly used for dynamic welding. The outer field of the arm is different from the welding of the thick plate structure. When laser welding, its temperature is high and the melting speed is faster, which in turn makes the welding speed faster and the welding deformation work capacity is small.

As a key type of construction machinery and equipment, small wood grabbers play a vital role in the infrastructure construction in our country, and their main uses are becoming more and more common, and even gradually replace construction machinery such as wood grabbers. The efficiency of the equipment, and the small wood grabber arm is very easy to cause problems such as deformation and cracking during welding. The small wood grabber arm is a key component of the small wood grabber, and its quality is immediately related to the small wood grabber. Performance indicators and product quality, once the deformation exceeds the standard value or the product is cracked, the product will be billed immediately, which is an expensive economic development cost for the company, so it seems crucial to carry out scientific research on the welding process of small wood grabber arms. important.