Structure Design Analysis of Circular High Pressure Connector

Overall design of circular high pressure connectors

Designing connectors with no air gap requires special requirements for the mating interface and wire terminations of the connector. When the voltage is high, the dielectric withstand voltage and creepage distance have new meaning. With the trend of miniaturization of connector structures, the size of connectors is getting smaller and the distance between the contact pieces and between the contact pieces and the shell is very small. Therefore, a special structure must be used to increase its creepage distance.

The mounting plate of the high pressure connector should be designed to fix the convex "conical" shape of the contact pieces in the axial direction and the corresponding "conical hole" shape, and at least one mounting plate should be made of silicone rubber. This structure increases the creepage distance between the contact pieces, and because of the existence of the cone, the entire mating surface can apply equal pressure.

Under a certain interface pressure, a certain amount of compression can be generated in the soft mounting plate, and a sealing structure can be added to the soft mounting plate to more effectively eliminate the air gap communication between the electrodes, and achieve the purpose of eliminating air gaps on the interface. The compression of the soft mounting plate is controlled by the combination of the conical base, hole, connecting sleeve, and corrugated spring.

The overall structural design of high pressure connectors is as follows

The fixed-end custom electrical connectors and the free-end electrical connector are composed of contact pieces, insulation mounting plates, shells, and tail accessories. The free-end connector is equipped with pin-contact components, and the mounting plate is made of silicone rubber with good dielectric strength and elastic modulus; the fixed-end electrical connector is equipped with socket contact components, and the mounting plate is made of hard insulation materials.

In order to prevent misinsertion, the free-end connector shell and the fixed-end connector shell are designed with a five-key slot structure. In order to achieve rapid separation, the free-end connector shell is equipped with a connecting sleeve. The inner bore wall of the connecting sleeve is designed with three equally spaced helical slot structures, and there is a pinhole at the bottom of the slot for observing the mating of the connector. Correspondingly, the fixed high pressure connector shell surface is designed with three locking pins that can be rotated to the bottom of the helical slot. After the free-end electrical connector is rotated into place, the connector can be locked.

On the free-end connector, rotate the connecting sleeve clockwise to complete the connection, and rotate the connecting sleeve counterclockwise to complete the separation. When the connector is fully engaged and the connecting sleeve is in the locked position, the corresponding pin end can be seen through the hole on the connecting sleeve.

Insertion interface design of high pressure connectors

In order to meet the requirements of high-voltage performance for connectors, the mounting plate must be designed with a structure different from that of general connectors. On the mating interface of the connector, the free-end adopts a silicone rubber soft mounting plate, which is designed with an inwardly concave "conical hole" structure to fix the pin-contact components; the fixed-end adopts a DAP hard mounting plate, which is designed with a outwardly convex "conical" structure to fix the socket contact components.

Wire sealing of high pressure connectors

Wire sealing includes wire sealing of free-end connectors and fixed-end connectors. For wires using fluoroplastics, to ensure a strong bond, the adhesive parts of the wires must be sandblasted to make the surface rough, and then corroded with a strong oxidizing treatment agent to form a free-radical-containing carbon film on the surface of the wire. The carbon-containing film reacts chemically with the sealing adhesive to form a true chemical bond.

When welding the wire to the contact piece, the area of the welding point should be small and level with the surface of the contact piece. On the one hand, this can avoid damaging the surface coating of the contact piece due to the large area of the welding point; on the other hand, it can also avoid sharp discharges caused by the protrusions or depressions of the welding point, and the formation of "air pumps" caused by gas adsorption during molding.

In the free-end high pressure connector, the wire processed above is welded to the contact pieces and then coated with a layer of silicon rubber adhesive. It is then sent into the silicone rubber soft mounting plate with a special tool, and then the hard mounting plate is tightened with a connecting nut to support the soft mounting plate and the wire.

In the case of fixed connectors, two problems need to be solved at the wire welding location: the creepage distance on the mating interface and wire sealing.