Flexible fixtures in the tower crane boom welding applications

   Shenzhen Paul automation equipment co., LTD. Is a three dimensional flexible modular fixture, the three dimensional flexible welding platform, the flexible welding jig, three-dimensional flexible welding equipment, welding fixtures, robot welding platform, robot welding jigs and fixtures, such as solution and manufacturing of professional providers.

 Tower cranes are widely used in building construction, the crane manufacturing also gradually formed a certain scale. Crane belongs to the special operation equipment, its product quality cannot be ignored, especially the standard section of the welding quality directly affects the quality of the whole machine, in the process of mass production, must by welding equipment to ensure the welding quality, such as perpendicularity, parallelism and interchangeability.

Now several section of the arm frame welding jig structure, the advantages and disadvantages of analysis is as follows:

　　A, knuckle arm shelf structure and function

Knuckle arm frame is an important structure of tower crane, as shown in figure 1 is mainly composed of pieces of 1 set of connection, two main chord, a three oblique abdominal rod, a four level of CHS, 5 node plate. Standard section is not only to support the upper close to the weight of the machine, but also inherit the tower when the rotary torque. In addition, the national standard requirements of tower after installation, vertical degree is not more than four over one thousand of the machine. Standard section, therefore, the quality is very important, not only to have enough intensity but also have good precision.

Second, knuckle arm frame welding process

In the manufacturing process to ensure the quality of the standard section, need to have welding equipment (equipment) to ensure the accuracy after welding. Section of the arm frame welding process is mainly: 1, blanking, stock; 2, will join with the main chord welding; 3, the two end of the main chord with double-sided milling machine processing level (4 pieces a set), and to ensure that the consistency on both ends of the parallel degree and length; 4, labor and technology, ensure the quality of each pieces of welding forming; 5, clean up after welding.

　　Section three, boom welding jig profile - section boom group for tooling system

1. Flexible working platform: 2500 mmx2500mm

2. The mobile platform height from the ground: around 300 mm

3. Total height: 2945 mm

4. Effective stroke: 12000 m (according to customer requirements and decide)

5. Flexible working platform and track vertical degree: 0.5 to 0.6 mm

6. The parallelism between the two flexible platform: 0.5 1 mm

7. After positioning platform range error: 1-2 mm

Superiority of knuckle arm frame nc group for tooling system:

1. In to guarantee the accuracy of the workpiece positioning and reliable pressure, on the basis of mobility, security and stability should be very reliable.

2. Track is one of the core technology of tooling, have special debugging equipment, with the adjustment of the special tools.

3. Easy and convenient to operate, pay attention to the personal safety of front-line workers and labor intensity.

4) can greatly improve the welding quality of products and improve production efficiency.

Section four, other boom welding jig

Now each tower crane production enterprise of the tooling form is varied, induction for the bending plate, integral, integral tilting. Now will introduce these tooling as follows:

　　1, the bending plate

Bending plate tooling as shown in figure 2: by a 5 m changping electric welding plate (1) and two (2), among them, a piece of plate bending Angle seat (3) is fixed, the other a piece of plate bending Angle seat (4) for telescopic, two pieces of plate bending with t-shaped bolt respectively with the platform. Place the main chord end when it was used in fixed Angle of groove, through screw (5) the telescopic Angle stretched out, and the main chord top tight, then put the knuckle arm oblique abdominal rod according to the requirement of spot welding forming. Finally, the arm frame is taken from the tooling, the whole welding and cleaning. The tooling structure is: the advantages of simple structure, low tooling cost. Defect is: tooling low accuracy, low accuracy standard after welding section, affected by the working space of standard section only spot welding on the tooling, can't complete the welding, the welding efficiency is low.

　　2, the tailstock rotary

Tailstock rotary tooling as shown in figure 3: from the handwheel (1), a 5 m changping station (5) and (2), (4), two cross the tailstock shaft (3). Tailstock bottom is equipped with positioning groove, the width and changping T slot size of the corresponding, the purpose is to guarantee the tailstock is accurate, and the two axle hole on the platform of alignment. In the tailstock are installed in the hole of the tail shaft, the tail shaft in the back of the ball screw drive can scale before and after the (similar to the lathe tailstock structure), the other end of the tailstock axis is equipped with two centripetal ball bearings, used for bearing the cross, with eight holes on the cross processing, its location and size and set of corresponding to the standard section of the connection. Tailstock of the tooling, and crosses were made from cast iron, in order to ensure the accuracy of equipment installation in the process of machining, boring machine processing the tailstock, as far as possible put two tailstock processing in pairs. In use process, in order to prevent the standard section that the phenomena of "NingJin" on the platform has two positioning block (6), ensure the main chord and bottom on the standard section of verticality. Since the weight of the cross section and standard is very heavy, the weight of the standard section at 350 kg, the weight of the cross at about 500 kg, tail shaft structure and for cantilever axis, thus produced on the tailstock shaft deflection is larger, in order to reduce the influence of deflection, and as far as possible make out two tail shaft length.

The tooling structure is: the advantages of high precision of welding, machining efficiency is high, the operator can easily on tooling standard section rotation, more than 80% of the weld can weld on the tooling. In addition, because the tail shaft is scalable, so when the height of the standard section have change, the tooling can be completely applicability. The disadvantage is that: the manufacturing cost is higher; Affected by the tail of the deflection of the shaft of the standard section of precision will produce certain deviation.

3, stationary frame

Frame fixed tooling as shown in figure 4: the two pieces of steel structure of the end plate (1) and four pillars of the connecting rod (2). On both ends of the board shall ensure that the location of the connecting hole, four root length of the connecting rod to agree, such ability assure welder is equipped with high precision. When use, will first good welding connection of the main chord with installed on the end plate, one side using wedge iron (3) the top down, on the other side is close to the end plate, and other artifacts from the main chord spot welding, after welding structure landed, and complete all the welding seam. This tooling is: the advantages of simple structure, low manufacturing cost, high processing efficiency, high precision. Defect is: unable to complete the weld on tooling, as the main chord side is by wedge iron roof, so the standard section on this side of the precision will be affected by certain influence.

4, frame rotary

Framework will be rotary tooling is several integrated the advantages of the former, and as far as possible to reduce manufacturing cost and improve the efficiency of processing equipment types, as shown in figure 5: similar to stationary, is composed of four on both ends of the plate and the connecting rod, the difference is that both ends of plate shape is not square but round, in this way, the entire equipment installed to the roller shelf, tooling can rotate at any Angle, easy processing. This tooling is: the advantages of simple structure, low manufacturing cost, and high efficiency, high accuracy, can be more than 80% of the transition cost of weld seam, and complete the welds on the tooling