Basic principles of process route setting for sheet metal production line

Basic principles of process route setting for sheet metal production line

The process route of the sheet metal production line must be set up with the shape of the product and the existing processing equipment of the company, in order to meet the requirements of product quality and ultimately to maximize the economic benefits.

The development of general process route can follow the following principles.

(1) Satisfy the product quality requirements;

(2) The product process route is economic;

(3) Provide optimization for subsequent processes;

(4) Convenient processing.

The focus of the process personnel’s consideration of quality comes from their grasp of the functionality and appearance of the product structure, as well as their proficiency in the processing capabilities of the equipment. Considering the cumulative error fit relationship of the whole machine, optimizing the product processing method to reduce the processing difficulty, and setting a relatively stable process route during mass production are the three directions to be considered for process preparation.

Cumulative error fit is a comprehensive reflection of the accumulated tolerance of the product itself manufacturing on the assembly, in the process analysis, should do the corresponding tolerance distribution to ensure that the cumulative error within the controllable range. Such as my company produces the AC electric control cabinet for such a typical product, now this is an example to expand the details.

AC electric control cabinets can generally be processed into assembled cabinets and welded cabinets. The more common is assembled cabinet, assembled cabinet typical main structure by the top frame, bottom frame, column, front door, back door and side door (plate) composition.

Deal with the processing process of these components, basically to ensure the processing quality of the cabinet products. General customers have certain requirements for the overall shape size of the cabinet after assembly, requiring diagonal size X1 and X2, X3 and X4 size difference of less than 2mm, according to the installation and use of the situation, customers have control over the width size L3, but the height and thickness of the size requirements are not strict. Because the customer design, generally with the body shape to the required size, did not consider the coating film thickness, resulting in workpiece spraying, assembly, the cabinet shape size will exceed the poor.

Therefore, it is necessary to adjust the coating margin for each component part to meet the width size L3, and also to ensure the size L1 and L2. Usually, the top frame, bottom frame and column are used to adjust the way together, and the adjustment amount varies according to the different assembly. The front and rear doors and side doors are generally embedded and installed between the upper and lower lintels, so the shape size is generally taken as negative deviation.

The coating margin needs to be adjusted according to the type of coating, taking into account the assembly gap and other factors, and generally adjusting the coating margin on the basis of taking the lower deviation in the control size (usually the door type takes the negative deviation and then leaves 0.5 to 1mm coating margin).

The optimization of the processing method lies in the adjustment of its processing sequence or process improvement, through a simple example to analyze and illustrate. Such as a door plate, this door plate single piece processing can focus on its quality and time, the general process scheme is: shear bed under the material → punching machine punching shape and inner hole → bending machine bending → welding four corners. Such a process program to save time and effort, but if the mass production of punching machine tool damage will intensify, greatly increasing the maintenance costs of the machine tool.

In addition, if the programming process is slightly problematic will cause irreparable damage. Since the role of this type of door plate shaped at the installation of door suction, so the mass production of such a door plate usually use the following processing scheme: shear machine material (three door suction small piece of separate material) → punching machine punching inside the hole → cutting corner → bending machine bending → welding four corners and three door suction small piece.