An electrical connector for traction transformer

Abstract

The present invention discloses an electric connector for a traction transformer, comprising a socket and a plug: the socket comprises a pin fixing seat, a fixing panel and a cylindrical ceramic body, the two ends of the ceramic body are respectively connected to the pin fixing seat and the fixing panel by welding, the inside of the welded ceramic body is a closed cavity, and the pin is connected to the pin fixing seat by a thread; the plug comprises a shell and a socket body arranged in the shell, the socket body is provided with a wire connection hole, the inner surface of the socket of the socket body is a rough wall surface, and a plurality of metal wires are arranged between the outside of the socket body corresponding to the socket and the shell; the present invention adopts a detachable structural design, which can enable the socket to complete the replacement of the pin in a high-pressure oil environment without draining the oil and removing the socket, thereby improving the maintainability of the overall connector and reducing the maintenance cost.

Description

Technical Field

[0001] The invention relates to the field of connectors, and in particular to an electric connector for a traction transformer used on a motor vehicle. Background Art

[0002] The electrical connector socket used for traction transformer output is immersed in transformer oil, and the output current is large and the transformer oil temperature rises, making it very difficult to inspect and repair the socket. This requires the electrical connector to have high oil resistance, protection, good electrical performance and maintainability.

[0003] The current electrical connector uses engineering plastics as insulating materials. Although it has good electrical properties, long-term immersion in transformer oil will cause degradation effects on the insulation properties of the plastics, and there is a high risk of failure. In terms of protection performance, the current electrical connector uses rubber seals for sealing to prevent leakage of transformer oil, but the aging of rubber is inevitable, which requires regular replacement of rubber seals. However, due to transformer oil, the cost of replacement is very high. The current electrical connector pin installation and wiring methods are all integral. When maintenance and replacement are required, they can only be replaced as a whole, resulting in a large waste of costs. The transformer output current is large, and the current electrical connector increases the current capacity by increasing the contact cross-sectional area. The electrical connector is correspondingly enlarged, which is not conducive to installation and use.

[0004] However, for the existing plugs that match the sockets, the connection between the pins and the sockets always has the problem of small effective contact area due to the manufacturing process and the use environment. In addition, the maintenance of the socket body will lead to the replacement of cables due to cable connection reasons, which is not conducive to on-site construction and maintenance.

[0005] However, for the current plugs that match the sockets, the connection between the pins and the sockets always has the problem of small effective contact area due to the manufacturing process and the use environment. In addition, the maintenance of the socket body will lead to the replacement of cables due to cable connection reasons, which is not conducive to on-site construction and maintenance. The current elastic element is usually in the form of a socket split slot, or an additional elastic part, which has the following disadvantages:

[0006] 1. The elasticity of the split groove closing depends on the strength of the material itself. When the strength is high, the conductivity will be reduced, which will cause the temperature of the contact to rise, especially when a large current passes through, which may cause contact failure;

[0007] 2. Adding a part will result in one more contact conversion, which will inevitably increase the contact resistance and may also cause the product to fail when a large current passes through it;

[0008] 3. Whether it is splitting the groove or adding parts, when a large current passes through, the diameter of the contact pair will increase with the increase of current. When the current reaches a certain level, the diameter of the contact pair will be very large, resulting in a large product volume and difficult operation;

[0009] 4. The connection between high-current jacks and cables usually adopts compression or terminal blocks, but both have the disadvantages of low reliability and difficult operation. Summary of the invention

[0010] The present invention proposes an improvement on the prior art, and its purpose is to change the socket of the existing connector so that the pins can be replaced without removing the socket as a whole during maintenance.

[0011] Another object of the present invention is to replace the insulating material on the basis of the existing socket and solve the problem that the ceramic material cannot be used under normal circumstances.

[0012] Another object of the present invention is to improve the existing plug and solve the problem of effective contact area between the pin and the socket.

[0013] In order to achieve the above object, the present invention adopts the following technical solution:

[0014] An electrical connector for a traction transformer, comprising a socket and a plug:

[0015] The socket comprises a pin fixing seat, a fixing panel and a cylindrical ceramic body, the two ends of the ceramic body are respectively connected to the pin fixing seat and the fixing panel by welding, the ceramic body after welding is a closed cavity, and the pin is connected to the pin fixing seat by a thread;

[0016] The plug comprises a shell and a socket body arranged in the shell, the socket body is provided with a wire connection hole, the inner surface of the socket of the socket body is a rough wall surface, and a plurality of metal wires are arranged between the outer part of the socket body corresponding to the socket and the shell.

[0017] In the above technical solution, a varable ring is provided between the ceramic body and the pin fixing seat, and between the ceramic body and the fixing panel.

[0018] In the above technical solution, one end of the kovable ring is sealed and welded to the ceramic body, and the other end of the kovable ring is sealed and welded to the pin fixing seat or the fixed panel.

[0019] In the above technical solution, the pin fixing seat is provided with a connecting hole, and a conical connecting surface is provided in the connecting hole.

[0020] In the above technical solution, the connecting hole includes a threaded cylindrical connecting section and a conical connecting section, and the inner surface of the conical connecting section is a smooth plane.

[0021] In the above technical solution, the pin includes a threaded connection section and a tapered connection surface that matches the connection hole, and the tapered connection surface is a smooth surface.

[0022] In the above technical solution, the inner wall of the jack of the jack body is evenly provided with a plurality of concave and convex petal-shaped structures along the axis.

[0023] In the above technical solution, the metal wire outside the jack body is sleeved on the jack body.

[0024] In the above technical solution, a wiring terminal is provided between the wire connection hole on the jack body and the wire.

[0025] In the above technical solution, a threaded connection end is arranged in the wire connection hole, one end of the terminal block is provided with a thread, the threaded section of the terminal block is threadedly connected to the wire connection hole, and the other end of the terminal block is connected to the wire through a crimping structure.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] The present invention improves the current carrying capacity by more than double under the same pin diameter by changing the plug structure;

[0028] The present invention improves the anti-aging ability of the socket in high-pressure oil by changing the socket structure, and the service life is increased by more than 10 years;

[0029] The present invention adopts a detachable structural design, which allows the socket to be replaced with a pin in a high-pressure oil environment without draining the oil or removing the socket, thereby improving the maintainability of the overall connector and reducing maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0031] Figure 1 It is a schematic diagram of the structure of the plug;

[0032] Figure 2 It is a schematic diagram of the structure of the socket;

[0033] Among them: 1 is an insulating shell, 2 is a socket body, 3 is a threaded connection end, 4 is a terminal, 5 is a wire, 6 is a fixed mounting plate, 7 is a pin, 8 and 10 are Kovar rings, 9 is a ceramic body, 11 is a pin fixing seat, and 12 is a fastening nut. DETAILED DESCRIPTION

[0034] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0035] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0036] The connector includes a socket and a plug. The socket is used in a fixed environment where it is immersed in transformer oil for a long time. The transformer oil has a very high temperature rise when the connector is powered on. Therefore, it is necessary to consider the service life of the socket material in the oil and the replacement and maintenance of the socket.

[0037] This embodiment makes structural improvements to the socket based on practical considerations, such as Figure 2 As shown, the socket includes a fastening nut 12, a pin fixing seat 11, a ceramic body 9 and a fixed mounting plate 6, wherein the fastening nut 12 is fixedly connected to the oil cylinder as a whole, the pin fixing seat 11 is connected to the fastening nut 12 by threaded connection, and the ceramic body 9 is connected between the pin fixing seat 11 and the fixed mounting plate 6. After the connection, the inside and outside of the ceramic body 9 are isolated and closed spaces, and the pin is connected to the pin connection seat 11 in the ceramic body 9 by threaded connection. After the entire socket is installed, the part below the fixed mounting plate 6 is completely immersed in the transformer oil. In the later maintenance process, there is no need to drain the oil and disassemble the socket, and the pin can be directly replaced from the ceramic body 9 by threaded connection.

[0038] In this embodiment, there are two improvements to the socket. One is that a ceramic body 9 is used to replace the traditional rubber parts, and the other is the connection method of the pin. First of all, for the ceramic body, in the electrical field, technicians know that the ceramic body has the best insulation performance and has an irreplaceable position in terms of insulation effect (especially in the high-voltage power transmission process). However, the ceramic body also has a fatal disadvantage, because the ceramic body is very fragile and easy to break, and the ceramic body can only be formed once and cannot be used for secondary processing. Therefore, in the field of connectors, plastic parts or rubber parts are generally used for overall one-time molding and pouring to complete the outer shape packaging of the connector. In this embodiment, after multiple tests, the ceramic body 9 is once molded into a cylindrical structure, and the two ends of the ceramic body are connected using a ferrule, the ferrule 8 is used to connect to the fixed mounting plate 6, and the ferrule 10 is used to connect to the pin connection seat 11. The ceramic body 9 and the ferrule are connected in the form of welding. After welding, the ferrule and the ceramic body are a sealed integrated structure, and the other ends of the ferrule are respectively sealed and welded to the fixed mounting plate 6 and the pin connection seat 11. After the connection, the ceramic body has a certain amount of deformation space because the Kovar ring has a certain margin. Therefore, when the connector is powered on, the high temperature causes the ceramic body to expand outward, and the expansion stress can be successfully offset by the Kovar ring.

[0039] In this embodiment, the pin is no longer fixed in the traditional way, because the traditional threaded connection holes or riveted holes are straight holes, and the pin may become loose after long-term use. In addition, because the connector works in a high-current environment, the contact area is an important factor to be considered. In this embodiment, a pin connection hole is provided on the pin connection seat 11, and the pin connection hole includes a threaded connection section and a contact surface with a conical structure. The conical structure of the pin connection hole matches the connection end structure of the pin. Figure 2 As shown, after the front end thread of the pin 7 is threadedly connected with the threaded connection hole, the tapered surface of the pin 7 contacts the tapered surface of the connection hole. When the threads are in mutual engagement, the tension of the threads can drive the tapered surface of the pin to be tightly pressed against the tapered surface of the threaded connection hole, thereby increasing the connection strength between the pin and the pin connection seat, and the tapered surface can increase the contact area between the pin and the pin connection seat.

[0040] The plug that matches the socket generally includes a shell and a jack body. The jack body is provided with a wire connection hole and a jack. The jack is connected to the pin of the socket, and the wire connection hole is used to connect the wire. In the traditional practice, the wire is generally connected by extrusion to squeeze the wire into the connection hole of the jack body. This connection method is very practical, but because the connector of this embodiment is used in a high-voltage and high-current environment, when the jack body is repaired, the wire end after removal will be deformed due to extrusion, and the deformed wire cannot be used again due to the change in its physical form. The connection end must be replaced, but it is obviously impossible to replace the wire in actual application, so the wire can only be trimmed. The premise of trimming the wire is that the wire must have enough margin during the initial installation to ensure that the trimmed wire can meet the use requirements, but this construction plan will inevitably increase the difficulty of electrical construction.

[0041] like Figure 1 As shown, the present embodiment makes an improvement on this situation. A threaded connection end 3 is provided in the wire connection hole on the jack body 2, and the end of the wire 5 is fixedly connected to the wiring terminal 4. A threaded structure is provided at one end of the wiring terminal 4. When the jack body 2 is connected, the threaded connection end 3 in the wire connection hole is threadedly connected through the threaded structure of the wiring terminal. When replacement is required, the wire and the wiring terminal are directly taken out from the jack body together. There is no need for secondary processing of the wire, and the electrical performance of the wire will not be affected.

[0042] For the socket on the socket body, the traditional connection method is to use an inner cylindrical structure, and the wall surface is a smooth surface. In theory, when the diameter of the cylinder is consistent, the contact area between the smooth walls is the largest. However, in actual experiments, it was found that our processing technology will cause tolerances between the pin and the socket. During the connection process, the position of the pin and the socket will be offset due to uneven force, especially after the connection, the external jitter will cause displacement between the pin and the socket. These real-life factors will lead to a reduction in the contact area between the pin and the socket. Therefore, in order to ensure the maximum increase in the amount of current passing through the effective contact area, this embodiment splits the inner wall of the socket into a number of petals, each of which is provided with a concave-convex structure, and the petal-like structure increases the contact surface between the pin and the socket.

[0043] In theory, the pin contacts the socket only at the point where each petal on the socket is tangent to the pin, so the more petals there are, the more contact points there are and the larger the contact area is; but if there are too many petals, the strength of the socket body will decrease, so in this embodiment, a steel wire for reinforcement is provided at the position corresponding to the socket on the outer wall of the socket body, and the steel wire fixes and reinforces the petals of the socket body. The steel wire is arranged between the socket body and the plug housing and is looped around the socket body.

[0044] When the pin is inserted into the socket, the petal-shaped socket body is acted upon by the steel wire to provide the pin with a sufficiently large elastic force. When the pin and the hole are deflected at an angle, the position of the pin and the socket can be calibrated by the tightening force of the steel wire to ensure that the pin and the socket can always maintain full contact. Experiments have shown that this method effectively increases the contact points between the socket body and the pin by adding grooves while meeting the strength requirements of the socket body, correspondingly increases the contact area, and improves the current passing capacity. Under the same pin diameter, the current passing capacity can be increased by more than double.

[0045] After long-term use, the plug and socket of this embodiment need regular maintenance. The present invention designs the jack body and the pin as a detachable structure. The cable on the plug is crimped to the terminal and fastened to the jack body by the threaded connection end. The pin on the socket is fastened to the pin fixing seat by threads. When maintenance or electrical failure occurs, the jack body and the pin can be directly removed from the plug and the socket. In particular, when the socket is immersed in transformer oil, the pin can be removed without disassembling the entire socket, which greatly improves maintenance efficiency and reduces maintenance costs.

[0046] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. An electrical connector for a traction transformer, comprising a socket and a plug, characterized in that: The socket comprises a pin fixing seat, a fixing panel and a cylindrical ceramic body. The two ends of the ceramic body are respectively connected to the pin fixing seat and the fixing panel by welding. A var ring is respectively arranged between the ceramic body and the pin fixing seat, and between the ceramic body and the fixing panel. The ceramic body after welding is a closed cavity. The pin is connected to the pin fixing seat by a thread. The plug comprises a housing and a socket body arranged in the housing, wherein the socket body is provided with a wire connection hole, the inner surface of the socket of the socket body is a rough wall surface, and the inner wall is evenly provided with a plurality of concave and convex petal structures along the axis. A plurality of metal wires are arranged between the outside of the socket body corresponding to the socket and the shell, and the metal wire ring is sleeved on the socket body, and the metal wires fix the plurality of petals of the socket body.

2. The electrical connector for a traction transformer according to claim 1, characterized in that: One end of the kovar ring is sealed and welded to the ceramic body, and the other end of the kovar ring is sealed and welded to the pin fixing seat or the fixing panel.

3. The electrical connector for a traction transformer according to claim 1, characterized in that: The pin fixing seat is provided with a connection hole, and a conical connection surface is provided in the connection hole.

4. The electrical connector for a traction transformer according to claim 3, characterized in that: The connecting hole comprises a threaded cylindrical connecting section and a conical connecting section, and the inner surface of the conical connecting section is a smooth plane.

5. An electrical connector for a traction transformer according to claim 3 or 4, characterized in that: The plug pin comprises a threaded connection section and a tapered connection surface which match the connection hole, and the tapered connection surface is a smooth surface.

6. The electrical connector for a traction transformer according to claim 1, characterized in that: A wiring terminal is arranged between the wire connection hole on the jack body and the wire.

7. An electrical connector for a traction transformer according to claim 6, characterized in that: A threaded connection end is arranged in the wire connection hole, one end of the terminal is arranged with a thread, the threaded section of the terminal is threadedly connected to the wire connection hole, and the other end of the terminal is connected to the wire through a crimping structure.

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