Double-layer dissimilar metal watertight junction box

Abstract

The utility model discloses a double-layer dissimilar metal watertight junction box. According to the utility model, the shell of the watertight junction box is arranged into two layers, the inner layer and the outer layer are electrically insulated, the local grounding end in the electronic circuit board is connected with the inner-layer box body and is connected with a ship body structure through a grounding wire on the inner-layer box body, and other signal transmission terminals and grounding terminals in the electronic circuit board are connected into a cabin through signal isolation conversion. The junction box is grounded together with the in-cabin part, so that an electric loop formed by directly connecting the junction box with a ship body is effectively avoided, potential corrosion caused by contact of dissimilar metals is avoided, and the service life of the junction box is prolonged. The device is simple in structure, low in cost and easy to implement.

Description

Technical Field

[0001] The utility model relates to the technical field of marine environment anti-corrosion, in particular to a double-layer heterogeneous metal watertight junction box. Background Art

[0002] For offshore vessels, outboard equipment and devices generally need to use the same metal material as the hull structure to avoid potential corrosion. However, some equipment has special application requirements such as structural strength and weight reduction design, and the shell needs to be made of a metal material different from the main structure of the ship. For such equipment, special isolation measures are generally required to prevent direct or indirect contact between dissimilar metals to form an electrical circuit and cause potential corrosion, such as anti-corrosion coatings and the addition of isolation pads. However, the internal analog circuits and digital circuits of some electronic equipment are isolated, and there is a need for multi-point grounding; the analog signal shielding needs to be grounded nearby outboard. If the junction box is directly grounded to the hull, even if the junction box body adopts anti-corrosion isolation measures, an electrical circuit will still be formed through the grounding wire, resulting in potential corrosion. Utility Model Content

[0003] In view of this, the utility model provides a double-layer dissimilar metal watertight junction box, which can effectively avoid potential corrosion and increase the service life of the equipment.

[0004] The double-layer heterogeneous metal watertight junction box of the present invention has a double-layer shell, including an inner box body and an outer box body; wherein the outer box body is made of a metal material required for the design of a watertight box and is inconsistent with the hull structure material; the inner box body is made of a metal material; the outer box body and the inner box body are insulated;

[0005] The electronic circuit board is arranged in the inner box body, and the electrical terminals that need to be grounded on site in the electronic circuit board are connected to the inner box body. The inner box body is connected to the grounding wire, and the grounding wire passes through the watertight connector installed on the outer shell and is connected to the hull structure; other information transmission terminals and grounding terminals of the electronic circuit board enter the hull cabin after signal isolation and conversion.

[0006] Preferably, the watertight connector is made of the same metal material as the outer box body; the outer shell of the watertight connector and the outer box body are electrically insulated from the inner core wire of the watertight connector.

[0007] Preferably, the outer box body and the inner box body are fastened together by insulating material.

[0008] Preferably, the inner box body is made of a metal material that is inconsistent with the hull structure.

[0009] Preferably, the material of the inner box body can be a metal material that is different from that of the outer box body.

[0010] Beneficial effects:

[0011] This utility model provides a double-layered watertight junction box with electrical insulation between the inner and outer layers. The local grounding terminal of the electronic circuit board is connected to the inner box body, and the grounding wire on the inner box body is connected to the hull structure. The other signal transmission terminals and grounding terminals of the electronic circuit board are connected to the cabin through signal isolation and conversion, and are grounded together with the cabin components. This effectively avoids the electrical loop formed by the junction box directly connecting to the hull, avoids potential corrosion caused by the contact of dissimilar metals, and improves the service life of the junction box. The utility model has a simple structure, low cost, and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the watertight box of the utility model. DETAILED DESCRIPTION

[0013] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0014] The utility model provides a double-layer dissimilar metal watertight junction box, such as Figure 1 As shown, the watertight junction box is designed as a double-layer structure. The outer box is constructed of metal material A, as required by the watertight box design. The inner box is constructed of metal material B, and the main hull structure is constructed of metal material C. While outer box material A and hull structure material C can be dissimilar metals, inner box material B can be a metal material that matches outer box material A, hull structure material C, or neither. The inner and outer boxes are fastened together with insulating material to ensure electrical isolation.

[0015] The electronic circuit board is placed in the inner box. The electrical terminals on the circuit board that require local grounding are connected to the inner box. The inner box is connected to the hull structure via a grounding wire. The grounding wire can pass through the outer box via a watertight connector. The watertight connector should be made of the same metal material as the outer box. The connector housing and the outer box are electrically insulated from the core wire inside the connector.

[0016] Other information transmission terminals on the circuit board and their grounding terminals are connected to corresponding output cables (connectors), which are connected to the inside of the hull cabin and grounded together with the inside of the cabin. The output cables (connectors) must be electrically insulated from both the inner and outer boxes.

[0017] For multi-layer junction box cascade transmission, before isolating circuits with different grounding requirements, also pay attention to the insulation requirements between the inner and outer shells. For digital circuits, grounding can be done near the cabinet inside the cabin.

[0018] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A double-layer dissimilar metal watertight junction box, characterized in that: The shell of the watertight junction box is double-layered, including an inner box body and an outer box body; wherein the outer box body is made of metal material required by the watertight box design and is inconsistent with the hull structure material; the inner box body is made of metal material; the outer box body and the inner box body are electrically insulated; The electronic circuit board is arranged in the inner box body, and the electrical terminals of the electronic circuit board that need to be grounded locally are connected to the inner box body. The inner box body is connected to the grounding wire, and the grounding wire passes through the watertight connector installed on the outer shell and is connected to the hull structure; other information transmission terminals of the electronic circuit board and its grounding terminals enter the hull cabin after signal isolation and conversion.

2. The double-layer dissimilar metal watertight junction box according to claim 1, characterized in that: The watertight connector is made of the same metal material as the outer box body; the shell of the watertight connector and the outer box body are electrically insulated from the inner core wire of the watertight connector.

3. The double-layer dissimilar metal watertight junction box according to claim 1, characterized in that: The outer box body and the inner box body are fastened together by insulating material.

4. The double-layer dissimilar metal watertight junction box according to any one of claims 1 to 3, characterized in that: The material of the inner box body is a metal material that is inconsistent with the hull structure.

5. The double-layer dissimilar metal watertight junction box according to any one of claims 1 to 3, characterized in that: The material of the inner box body is a metal material different from that of the outer box body.

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