An AC power distribution box based on shielded grounding

Abstract

The present invention relates to the technical field of junction boxes, and aims to solve the problem in the prior art that the tram power supply equipment is far away from the motor, and the cables need to be arranged through the wall multiple times according to the body structure, and if the cables are damaged, they are difficult to replace. An AC power supply junction box based on shielded grounding is provided, including a box body, the box body is provided with an inspection cover and a grounding column, the box body is provided with a terminal mounting plate, the terminal mounting plate is provided with a plurality of wiring terminals, one end of the wiring terminal is connected to the incoming cable, and the other end of the wiring terminal is connected to the outgoing cable, the junction box can realize the cable passing through the wall and pre-position the cable; the AC power supply junction box described in the present invention is small and light, and can be installed in different positions according to different body brackets; the junction box has a high degree of integration, a simple structure, low cost, good airtightness and watertightness, and meets the requirements of lightweight, space limitation and cost reduction design.

Description

Technical Field

[0001] The present invention relates to the technical field of junction boxes, and in particular to an AC power supply junction box based on shielded grounding. Background Art

[0002] With the acceleration of urbanization, the population is highly concentrated in large and medium-sized cities, and the demand for rail transportation has increased, which has promoted the rapid development of trams and also put forward higher requirements for the reliability and maintainability of trams. For the most common wheel-rail vehicles among rail vehicles, the running gear motor is the most important vehicle power. Its AC power supply cable has a great interference on low-voltage signal equipment. Generally, 50mm 2 Due to the layout restrictions of 100% low-floor trams, the power supply equipment is placed on the roof, which is far away from the running motors placed on the bottom of the car. In addition, the cables need to be laid through the walls multiple times according to the car body structure, and the length is long. Once a cable is damaged due to accident or aging, the entire cable will be unable to be replaced. Therefore, a junction box must be installed in the middle to split the cables, subdividing the original long cables into roof sections, passenger compartment sections, and chassis sections for easy maintenance. The design of the junction box needs to consider the following issues:

[0003] 1. The junction box should be able to ensure that the cables pass through the vehicle body or other metal panels;

[0004] 2. It must have a grounding function, preferably a separate grounding function, so that the AC line shield can be reliably grounded;

[0005] 3. Use 50mm 2 Shielded cables with a diameter of 20mm or more are generally difficult to bend. In the case of limited space, it is necessary to ensure that the cables are straight in the box after wiring.

[0006] 4. The design of the junction box should have good waterproof sealing measures to ensure the air tightness and water tightness of the vehicle and meet the protection requirements of IP65;

[0007] 5. After the junction box is installed and wired, the drainage of accidental water ingress and condensation water should be considered; 6. The installation space of rail vehicles is limited, and the focus should be on size and lightweight. Summary of the Invention

[0008] The present invention aims to provide an AC power distribution box based on shielded grounding to solve the problems in the prior art that the tram power supply equipment is far away from the motor, and the cables need to be laid through the wall multiple times according to the vehicle body structure, and if the cables are damaged, they are difficult to replace.

[0009] The present invention is achieved by adopting the following technical solutions:

[0010] An AC power supply distribution box based on shielded grounding includes a box body, an inspection cover and a grounding column are provided on the box body, a terminal mounting plate is provided inside the box body, and a plurality of wiring terminals are provided on the terminal mounting plate. One end of the wiring terminal is connected to the incoming cable, and the other end of the wiring terminal is connected to the outgoing cable. The distribution box can realize the cable passing through the wall and pre-position the cable.

[0011] The AC power supply distribution box described in the present invention can be used on various wheel-rail rail transit vehicles such as trams and light rails, so that the motor power supply cables can pass from inside the vehicle to outside the vehicle. The distribution box is mainly used for AC line distribution, especially for the distribution of power lines such as motors, to realize the disconnection of the motor AC power supply line.

[0012] Since most trams on the market currently have their power supply equipment placed on the roof, which is far away from the running motors located on the bottom of the vehicle, and the cables need to be laid through the wall multiple times according to the vehicle body structure, which brings great difficulties to subsequent maintenance, therefore, junction boxes or disconnect terminals are generally set at appropriate locations for disconnection, dividing the cables into different sections.

[0013] The AC power distribution box of the present invention is compact and lightweight and can be installed in different locations according to different vehicle body brackets. The distribution box allows cables to pass through the vehicle body or other metal panels, providing a cable through-the-wall function, and can also pre-position the cables to avoid installation errors.

[0014] Based on the vehicle's requirements for electromagnetic shielding, the junction box described in the present invention is provided with a grounding post to provide a grounding point for the AC cable with a shielding layer, so that the shielding layer can be grounded nearby, ensuring the shielding function and solving the electromagnetic interference problem caused by the AC power supply cable; a separate grounding point is set in the box, so that the AC cable shielding layer can be grounded separately at the near end and not shared with other grounding points, thereby avoiding the potential difference caused by the shared grounding point.

[0015] The AC power distribution box of the present invention has good sealing performance and meets the protection level requirement of IP65.

[0016] The AC power distribution box of the present invention has a high degree of integration, a simple structure, low cost, and good airtightness and watertightness, and meets the requirements of lightweight, space limitation and cost reduction design.

[0017] As the preferred technical solution:

[0018] The junction box body is made of SUS 304 material and is painted, and can adapt to the environment outside the vehicle.

[0019] As the preferred technical solution:

[0020] The box body is provided with a wire inlet and a wire outlet, and the centers of the wire inlet, the wire outlet, and the wiring terminal connection port are in a straight line.

[0021] The cables can be fixed smoothly after entering the box, ensuring that the cables can be laid straight without being subjected to bending stress.

[0022] As the preferred technical solution:

[0023] The number of the line inlets and the number of the line outlets are both four.

[0024] Meet the three-phase four-wire AC power supply principle.

[0025] As the preferred technical solution:

[0026] A steel pipe is provided at the wire inlet for the incoming cable to pass through; a threaded sleeve is provided at the wire outlet for the outgoing cable to pass through and position the outgoing cable.

[0027] The junction box can not only have the function of cable passing through the wall, but also can well pre-position the cables for installation to avoid installation errors.

[0028] As the preferred technical solution:

[0029] A one-way drain valve is provided at the bottom of the box.

[0030] When water accidentally enters the junction box or condensation water accumulates to a certain amount, the water can be discharged through the one-way drain valve to avoid the risk of electrical short circuit.

[0031] As the preferred technical solution:

[0032] A waterproof rubber strip is provided between the inspection cover and the box body.

[0033] Used to seal junction boxes.

[0034] As the preferred technical solution:

[0035] A gasket is provided on the inspection cover, a through hole for the gasket to pass through is opened on the waterproof rubber strip, and the gasket is in contact with the box body.

[0036] The gasket is located between the inspection cover and the box body. While ensuring that the waterproof strip has a reliable compression amount to play a waterproof role, it can also play a supporting role to ensure that the waterproof strip will not be damaged by excessive extrusion.

[0037] As the preferred technical solution:

[0038] The inspection cover is connected to the box body by bolts, and the bolts are arranged through the washers.

[0039] The bolt connection method is simple, easy to disassemble and easy to repair;

[0040] When the inspection cover and the waterproof strip are in close contact with the box body, the gasket is always located between the inspection cover and the box body. When tightening the bolts, the compression of the waterproof strip can be accurately controlled to prevent the waterproof strip from being crushed due to the stress of the bolts.

[0041] As the preferred technical solution:

[0042] The gasket may be made of metal.

[0043] As the preferred technical solution:

[0044] The waterproof rubber strip may be made of EPDM material with high compression.

[0045] As the preferred technical solution:

[0046] The gasket is welded to the inspection cover.

[0047] As the preferred technical solution:

[0048] The thickness of the waterproof rubber strip is 3-5 mm, and the thickness of the gasket is 2-3 mm.

[0049] As the preferred technical solution:

[0050] A mounting plate is provided on the top of the box body, and the junction box is mounted on the vehicle body through the mounting plate.

[0051] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0052] 1. In addition to installing branch terminals, the junction box can also serve as a wall-penetrating cable passage.

[0053] 2. Four input and output positions are set on both sides of the box to meet the needs of all three-phase four-wire AC power supply motors.

[0054] 3. A separate grounding point is set inside the box, so that the AC cable shield can be grounded separately at the near end and not shared with other grounding points, avoiding the potential difference caused by the shared grounding point and solving the electromagnetic interference problem caused by the AC power supply cable.

[0055] 4. The centers of the junction box inlet, terminal connection points, and outlet are in a straight line to ensure that the cables are straight and that the cables, especially high-voltage cables, are not subject to bending stress.

[0056] 5. A one-way drain valve is installed inside the box to avoid the risk of short circuit caused by accidental water ingress.

[0057] 6. Washers are pre-welded at the bolt fixing points on the inspection cover. After the inspection cover and the waterproof strip are tightly attached to the box body, the washers are always located between the inspection cover and the box body. When tightening the bolts, the compression of the waterproof strip can be accurately controlled to prevent the waterproof strip from being crushed due to the stress of the bolts.

[0058] 7. The junction box adopts various forms of airtight and watertight designs to meet the IP65 protection level. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a structural diagram of the AC power distribution box based on shielded grounding according to the present invention.

[0060] Figure 2 for Figure 1 Front view of .

[0061] Figure 3 for Figure 1 Left view of .

[0062] Figure 4 for Figure 1 Right view of .

[0063] Figure 5 for Figure 1 Top view of .

[0064] Figure 6 This is an exploded view of the parts of the AC power distribution box based on shielded grounding according to the present invention.

[0065] Figure 7 This is a schematic plan view of the first inspection cover plate of the present invention.

[0066] Figure 8 This is a side view of the first inspection cover described in the present invention.

[0067] Figure 9 This is a result diagram of the AC power supply distribution box based on shielded grounding after cables are arranged as described in the present invention.

[0068] Figure 10 This is a structural schematic diagram of an AC power supply distribution box based on shielding grounding according to the present invention installed on a vehicle.

[0069] Icon: 1- box body, 2- first inspection cover, 3- second inspection cover, 4- steel pipe, 5- grounding column, 6- one-way drain valve, 7- threaded sleeve, 8- terminal block, 9- terminal mounting plate, 10- mounting plate, 11- first waterproof rubber strip, 12- second waterproof rubber strip, 13- gasket, 14- incoming cable, 15- outgoing cable, 16- vehicle body. DETAILED DESCRIPTION

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0071] Example 1

[0072] See also Figures 1-10 This embodiment proposes an AC power distribution box based on shielded grounding, including a box body 1, and openings are provided on two sides of the box body 1. A detachable inspection cover is provided at the opening, and the inspection cover is used to close the opening. The inspection cover includes a first inspection cover 2 and a second inspection cover 3, which are respectively located at the openings on the two sides of the box body 1.

[0073] In this embodiment, the junction box body is made of SUS 304 material and painted, which can adapt to the environment outside the vehicle. The inspection cover is also made of SUS 304 material. The inspection cover is installed on the box body 1 using M6x20 bolts and is removed during wiring, installation and maintenance.

[0074] A terminal mounting plate 9 is provided inside the box 1, and a plurality of wiring terminals 8 are provided on the terminal mounting plate 9. One end of the wiring terminal 8 is connected to the incoming cable 14, and the other end of the wiring terminal 8 is connected to the outgoing cable 15. The junction box can realize the cable passing through the wall and pre-position the cables.

[0075] In this embodiment, a line inlet is provided on one side of the box body 1, and a line outlet is provided on the first inspection cover 2. The line inlet and the line outlet are located on two opposite sides of the box body 1. The centers of the line inlet, the line outlet, and the wiring port of the terminal block 8 are in a straight line, which is used to ensure that the cables are arranged straightly and are not subject to bending stress.

[0076] The number of the line inlets and the line outlets is four, satisfying the principle of three-phase four-wire AC power supply.

[0077] Each inlet is equipped with a seamless steel tube 4, and each outlet is equipped with a threaded sleeve 7. The steel tube 4 is welded to the box 1. The incoming cables 14 pass through the steel tube 4 and are crimped onto stud terminals 8 using cold-pressed terminals. The outgoing cables 15 are then tightened through the threaded sleeve 7 before exiting. This allows the box to not only pass cables through walls but also effectively pre-position the cables for installation, preventing installation errors.

[0078] The AC power supply distribution box described in the present invention can be used on various wheel-rail type rail transit vehicles such as trams and light rails. The distribution box is mainly used for AC line distribution, and is particularly suitable for line distribution of power lines such as motors, to realize disconnection of the AC power supply line of the motor.

[0079] Since most trams on the market currently have their power supply equipment placed on the roof, which is far away from the running motors located on the bottom of the vehicle, and the cables need to be laid through the wall multiple times according to the vehicle body structure, which brings great difficulties to subsequent maintenance, therefore, junction boxes or disconnect terminals are generally set at appropriate locations for disconnection, dividing the cables into different sections.

[0080] The AC power distribution box of the present invention is compact and lightweight and can be installed in different locations according to different vehicle body brackets. The distribution box can not only pass cables through the wall, but also can well pre-position the cables for installation to avoid installation errors.

[0081] Based on the vehicle's requirements for electromagnetic shielding, the junction box described in the present invention is also provided with a grounding column 5, which provides a grounding point for the AC cable with a shielding layer, so that the shielding layer can be grounded nearby, ensuring the shielding function and solving the electromagnetic interference problem caused by the AC power supply cable; a separate grounding point is set in the box body 1, so that the AC cable shielding layer can be grounded separately at the near end, and not shared with other grounding points, thereby avoiding the potential difference caused by the shared grounding point.

[0082] The grounding column 5 is made of copper-clad aluminum, and the surface is made of brass material with high conductivity to ensure good electrical performance and reliable grounding. The center is made of aluminum alloy, and the prefabricated M8 thread is used for connecting the grounding wire, which is connected to the external grounding point through the grounding wire.

[0083] The AC power distribution box of the present invention has a high degree of integration, a simple structure, low cost, and good airtightness and watertightness, and meets the requirements of lightweight, space limitation and cost reduction design.

[0084] Example 2

[0085] The difference between this embodiment and embodiment 1 is that a one-way drain valve 6 is provided at the bottom of the box body 1. When water accidentally enters the junction box or condensation water accumulates to a certain amount, the water can be discharged through the one-way drain valve 6 to avoid the risk of electrical short circuit.

[0086] Example 3

[0087] The difference between this embodiment and embodiment 1 is that a first waterproof rubber strip 11 is provided between the first inspection cover 2 and the box body 1, and a second waterproof rubber strip 12 is provided between the second inspection cover 3 and the box body 1, and the waterproof rubber strips are used to seal the junction box.

[0088] Example 4

[0089] This embodiment differs from Embodiment 3 in that washers 13 are provided at the screw holes on the access cover, and through holes are provided in the waterproof strips (first waterproof strip 11 and second waterproof strip 12) for the washers 13 to pass through. The washers 13 are located between the access cover and the housing 1, abutting against the housing 1 to ensure that the compression of the waterproof strips remains within a normal range after torque is applied. The access cover is connected to the housing 1 via bolts and rivet nuts, with the bolts passing through the washers 13.

[0090] Preferably, the gasket 13 is made of metal and welded to the inspection cover; the waterproof rubber strip is made of high-compression EPDM material.

[0091] When sealing the junction box, the access cover and the waterproof strip are tightly attached to the box body 1. The waterproof strip is located between the access cover and the box body 1, and the gasket 13 is also always located between the access cover and the box body 1. Because the gasket 13 is relatively hard, it can ensure that the distance between the access cover and the box body 1 is not too small, and the waterproof strip is not damaged by excessive compression, ensuring that the waterproof strip has a reliable compression capacity to play a waterproof role. When tightening the bolts, the compression of the waterproof strip can be precisely controlled to prevent the waterproof strip from being crushed by the bolt stress.

[0092] Preferably, the thickness of the waterproof rubber strip is 3-5 mm, and the thickness of the gasket 13 is 2-3 mm.

[0093] Example 5

[0094] This embodiment differs from Example 1 in that a mounting plate 10 is provided on the top of the box 1. This mounting plate 10 and bolts are used to suspend the junction box from the underframe of a vehicle body 16. A hole is provided in the vehicle body 16 to allow the steel pipe 4 to be inserted into the vehicle body 16, ensuring that the air pressure inside the vehicle body 16 and the junction box are the same. The junction box's sealed design prevents drastic pressure fluctuations during high-speed operation, preventing discomfort to passengers.

[0095] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An AC power distribution box based on shielded grounding, characterized by: The box comprises a box body, on which an inspection cover and a grounding column are provided, a terminal mounting plate is provided inside the box body, and a plurality of wiring terminals are provided on the terminal mounting plate. One end of the wiring terminal is connected to the incoming cable, and the other end of the wiring terminal is connected to the outgoing cable. The junction box can realize the cable passing through the wall and pre-position the cables; The box body is provided with a wire inlet and a wire outlet, and the centers of the wire inlet, the wire outlet, and the wiring terminal connection port are in a straight line; The number of the line inlets and the line outlets is four; The inlet is provided with a steel pipe for the inlet cable to pass through; the outlet is provided with a threaded sleeve for the outlet cable to pass through and position; A one-way drain valve is provided at the bottom of the box; A waterproof rubber strip is provided between the inspection cover and the box body; A gasket is provided on the inspection cover, a through hole for the gasket to pass through is opened on the waterproof rubber strip, and the gasket abuts against the box body; The inspection cover is connected to the box body by bolts, and the bolts are arranged through the washers; The thickness of the waterproof strip is 3-5 mm, and the thickness of the gasket is 2-3 mm; A mounting plate is provided on the top of the box body, and the junction box is mounted on the vehicle body through the mounting plate.

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