With the gradual overcapacity of the manufacturing industry, it is more and more important to improve the market share of their products on the premise of market saturation, which requires enterprises to greatly improve their sensitivity to market demand.
Plane laser and three-dimensional laser are more and more favored by the market because of their strong flexible processing ability, rapid production transformation and small tooling investment in the early stage.
The embodiment of the above advantages is inseparable from the production of the jigs used.
Good jigs can give better play to the flexible processing capacity of the equipment and ensure the quality of the final product.
Discussion on the manufacture of different types of jigs
Different equipment uses different jigs, which can be roughly divided into two categories: 2D jigs and 3D jigs. They are described below.
Two-dimensional jigs are mainly used for plane laser cutting of plane steel plates. Its main function is to support the steel plate and ensure that the equipment can carry out the corresponding cutting operations on the steel plate smoothly.
Because the two-dimensional cutting operation is completed in one plane, the required jigs are relatively simple, which only needs to ensure smooth processing on the two-dimensional plane.
In the process of design and manufacture, first determine the processing range of the equipment, that is, the maximum processing plane size.
After determining the maximum size, design the cutting jigs according to the data of equipment processing blind area, boundary size and so on.
Steel plate is generally selected as the basic material, and reasonable support clearance shall be selected in the design process to ensure that the raw materials will not deform due to self-weight in the cutting process.
In order to ensure the cutting quality and prolong the service time of jigs, it is necessary to carry out secondary processing on the steel plate for manufacturing jigs, so that the support of raw materials and steel plate is one point by one.
The whole jigs use the points on the steel plate to support the raw materials. At the same time, in order to avoid the scratch of raw materials caused by sharp points, it is best to design the contact point as a circular arc surface, as shown in Fig. 1, and the structure of the contact point is shown in Fig. 2.
Fig. 1 Steel plate structure for support
Fig. 2 Structure of contact point
The steel plate for support is fixed on the foundation bridge.
The foundation bridge can be fabricated by selecting angle steel for welding according to specific requirements, and the strength can meet the use requirements.
It should be noted that when fixing the steel plate on the foundation bridge, it is best to select the screw connection method.
The laser cutting jigs belong to vulnerable parts. After long-term use, the supporting steel plate will inevitably be damaged by the laser, and it needs to be replaced regularly.
The method of screw connection can reduce the replacement cost and improve the replacement speed.
In addition, during the assembly process, ensure that the clearance of the supporting steel plate should not exceed 100mm, so as to avoid the falling of products and raw materials after cutting.
Three-dimensional jigs, as the name suggests, are used to ensure the processing of products in three-dimensional space.
It can be divided into grid jigs, jigs positioned by profile and electromagnetic jigs.
(1) Grid jigs.
Before making jigs, observe and analyze the parts to confirm whether the parts are easy to deform.
Grid jigs can be considered when there is little difference between the final parts and digital simulation;
For the three-dimensional workpiece of the thin plate which is elastic and easy to deform, the grid jigs can also be used for correction.
Firstly, the logarithmic analog is analyzed, and the digital-analog section line of the part is made in the three-dimensional software, as shown in Figure 3.
After making the section line, make the plan with cutting notch according to the section line projection, as shown in Figure 4.
After the plan is made, according to the actual needs of the parts, use 2 ~ 5mm steel plate to cut and process as shown in Figure 4.
Fig. 3 Making digital and analog section line after part modeling
Fig. 4 Plan view with cutting notch
Fig. 5 Cutting according to the plan
During the manufacturing process, it shall be noted that the corresponding openings and assembly feet shall be reserved in advance to facilitate the final assembly. After the assembly is completed, the assembly, dimension correction, welding and fixation shall be carried out according to the digital-analog design, as shown in Fig. 6.
Fig. 6 Assembly, dimension modification, welding and fixing
After the final fixed welding is completed, the corresponding dimensions shall be measured and confirmed again.
The differences can be corrected by hand-held grinding equipment such as grinder.
(2) Jigs positioned by profile.
For parts with complex profile, such jigs can be selected. Firstly, select the part with large division R angle on the complete part profile as the jigs support surface;
Then, laser or plasma cutting is used to segment the product sheet. During this period, it is necessary to ensure that the cut sheet does not produce overheating deformation;
Next, put a piece of intact product workpiece upside down on the ground or working platform, and fully fit the divided product wafer on the inner surface of the workpiece according to the profile, as shown in Fig. 7
Fig. 7 Positioning workpiece with profile positioning jigs
The application program developed based on the Windows operating system platform is a platform with multiple tasks, that is, the application program can perform multiple tasks, but only the Windows operating system can be selected.
The application developed based on the embedded system platform should not only perform multiple tasks but also run across multiple operating system platforms, which requires the embedded system to have high portability.
Finally, the fabricated frame support shall be inverted on the surface of the product sheet for spot welding.
In the final welding process, round steel shall be used to weld and reinforce the support sheet, as shown in Fig. 8.
Fig. 8 Round steel for welding and strengthening the support sheet
The following points shall be paid attention to in the manufacturing process of such jigs: the maximum size of the divided sheet shall not exceed 150mm;
In the final welding process, pay attention to avoiding welding adhesion between the surface of the segmented sheet and the workpiece.
(3) Electromagnetic jigs.
Electromagnetic jigs is widely used in recent years with the deepening application and promotion of automation equipment in the field of sheet metal and welding.
Its advantages are as follows: the workpiece can better enter the accurate position; Reduce the time of manual decoration; It is convenient for manual operation and reduces labor intensity to a certain extent.
On the basis of the above two kinds of jigs, the electromagnetic jigs realize the rapid positioning of the workpiece by further optimizing its basic structure and adding electromagnet and ensuring the stable position of the workpiece in the processing process.
Based on the completion of the above two jigs, the position and length of the electromagnetic fixed support shall be determined on the support.
Next, process the mounting hole position on the square steel according to the required size of the electromagnetic mounting hole.
Then weld the electromagnetic mounting bracket, finally install the traction electromagnet and assemble the power supply and control line, as shown in Fig. 9.
Fig. 9 Electromagnetic jigs structure
Pay attention to the following points in the manufacturing process: the diameter of the mounting hole is larger than the diameter of the fastening screw for later adjustment;
First, weld the electromagnet on the fixed support, and then weld the fixed support on the jigs; The electromagnetic mounting bracket shall avoid laser cutting track;
Cables used for electromagnets shall be resistant to high temperature, and the routing shall avoid laser track;
The most important thing is that the working point of the electromagnet should be on the surface of the finished part.
Since the electromagnetic jigs need electricity in the production and use process, the electrical engineer of the unit must participate in the production and conduct corresponding management and inspection according to the electrical management system of the unit, as shown in Fig. 10.
Fig. 10 Power supply structure of electromagnetic jigs
Inspection and commissioning of jigs
After the jigs are manufactured, it is necessary to check and debug the parts before mass production, mainly in the following aspects.
(1) The clearance between the jigs and the part surface should not be too large, which is generally controlled within 1mm;
(2) Before production, the position of jigs on the table shall be determined to ensure that there is no dead corner in the processing process;
(3) After confirming that there is no dead angle, fix the jigs on the table with the triangular fixing method. Note that, like the electromagnet mounting hole, the hole diameter should be greater than the diameter of the fastening screw and the diameter of the fixing hole on the table, so as to facilitate the fixing with the pressing plate;
(4) If it is found that the cutting track cannot avoid the support point of jigs and workpiece after simulation, it is necessary to avoid the groove on the support point.
Finally, before making jigs, fully consider the types and characteristics of processed products, and select appropriate materials and jigs types in combination with the actual use needs of the unit, so as to avoid unnecessary waste.
This post introduces the commonly used two-dimensional and three-dimensional jigs manufacturing methods and precautions.
The above is only my thoughts.
Different products, production modes and site conditions have different requirements for jigs manufacturing, which requires specific analysis by technicians according to the actual situation, only in this way can the jigs most suitable for the needs of the unit be selected.