1、 Front and rear engineering process design

APre-engineering process

1. The design of terminal crimping parameters is unreasonable, and the terminal head is tilted back and forth

Such problems are relatively easy to find and have a small probability of occurrence. Some terminal drawings also put forward reasonable requirements for the selection of height and width values.

2. Improper selection of terminal insulation crimping shape

The unreasonable height and width of the insulation part of the terminal and the unreasonable design of the crimping shape will cause the terminal to shake a lot in the sheath, causing the terminal to easily deviate from the position of the butt hole when the sheath is butted.

BPost-engineering process

1. Low forward insertion rate of male terminal

The work pace on the assembly line is short, and 100% vertical insertion cannot be guaranteed. A large number of male terminals are inserted on the assembly line, which is easy to lead to terminal insertion deviation, especially the probability of male terminals with smaller width and thickness is higher.

2. The wiring sequence is designed so that the male terminal is waiting for operation

The design of wiring operation sequence is not reasonable. The male terminal that has not been implanted should be wired first, and then the sheath should be set for the terminal to be implanted, which is easy to cause the terminal to be squeezed and deformed on the clamp.

Countermeasures:

1. Reasonably design crimping parameters and necessary inspection tools to prevent the terminal from tilting forward and backward.

2. Reasonably design the crimping shape of the insulation part of the terminal to reduce the movement space of the terminal in the sheath.

3. Improve the plug and pull ratio of male terminal, try to make the male terminal work on the sub-assembly table, and ensure vertical interpolation. At the same time, it can reduce the extrusion deformation of bundled terminals from sub-packaging and transportation to final assembly.

4. The whole wiring sequence cannot guarantee the 100% insertion rate of the male terminal, especially for the terminal with small thickness and width, the sheath end of the male terminal should be connected first. The male terminal of this later distribution shall be immediately inserted into the sheath.

2、 Manufacturing process

Each link in the manufacturing process may cause terminal deformation, especially in the process of crimping, planting and handling.

Crimping

The main reason why the crimping station is easy to cause terminal skew is that the control and protection of the crimping process are not in place.

Countermeasures:

The crimping finished product needs to be equipped with a protective cup. In addition, attention should be paid to the problem of the front and back tilt of the terminal during the crimping process. For the male terminal that is easy to tilt forward and backward, use the professional detection tools designed and manufactured to control the front and back tilt of the first, middle and end products during the crimping, and filter out 99% of the hidden dangers from the beginning.

Subpackage

Pay attention to the process protection of the terminal to prevent the terminal from being squeezed during transportation at the sub-loading station. Problems during repacking:

1. The terminal hook is deformed in the process of splitting and pulling;

2. The planting operation is not standardized, and the deformation is caused by non-vertical insertion.

Countermeasures:

Pay attention to the standardization of operation at the sub-loading station, insert the side of the male terminal first, ensure the vertical insertion, and pay attention to the status of the terminal after insertion. In addition, the design and reasonable use of interpolation tooling will also reduce the occurrence of defective products.

Final assembly

The final assembly is greatly affected by the operation sequence, which is usually caused by the terminal skew caused by the insertion operation after the male terminal.

1. The wiring sequence is unreasonable. The male terminal is hung on the board first, and is squeezed and deformed when clamping the fixture;

2. The male terminal is located in the operation area with dense wires, which is easy to be touched or pulled by other wires or plug-ins during wiring.

3. The planting operation is not standardized, and the deformation is caused by non-vertical insertion.

Countermeasures:

Strictly follow the process design sequence, reduce the interpolation operation of the final assembly male terminal, pay attention to the standardization of the vertical insertion operation, and conduct self-inspection on the terminal status after the insertion.

Electrical inspection

The electric inspection platform is not equipped with vertical detection or the detection tolerance of vertical detection module is too large. Some electrical inspection modules can only detect deflection in the vertical direction, but not in the horizontal direction.

Countermeasures:

The vertical detection module of the electrical detection platform shall be reasonably selected and designed to minimize the size of the detection position. After the electrical inspection, the auxiliary calibration fixture can be used for calibration.

3、 Packaging and main engine factory assembly

packing

For the male connector with more holes and larger size, the cavity is easy to be embedded by other small parts, resulting in terminal extrusion deformation.

Countermeasures:

Try to protect the larger male connector separately, add a protective sleeve or wrap it in a bag.

Harness assembly

The unreasonable design structure leads to blind insertion and non-vertical docking between male and female terminals, which is easy to lead to extrusion deformation of terminals.

Countermeasures:

For connectors with more hole positions and smaller male terminals, more assembly space is preferred.

Before assembly, check whether the male terminals are not parallel, standardize the assembly operation and butt vertically.