An explosion-proof junction box for automatic retractable cables

Abstract

This utility model discloses an explosion-proof junction box with automatic retractable cable. It features a built-in winding device for cable extension and retraction. During adjustment, the cable is simply pulled out for connection, and automatically retracts after resetting, preventing redundant cable accumulation. It replaces the traditional rigid "pipeline-equipment" connection with a flexible "pipeline-telescopic junction box-equipment" connection, creating a buffer zone for debugging. This significantly reduces wiring and disassembly time, improving debugging efficiency. The cable can be reused repeatedly, resulting in significant economic benefits. The limit buckle design restricts excessive cable extension, and the junction box is detachable and reusable within a sealed cavity, enabling dynamic cable extension and retraction. This overcomes the technical bias of traditional explosion-proof equipment with immovable wiring, making it suitable for large-scale industrial use and promotion.

Description

Technical Field

[0001] This utility model belongs to the field of industrial electrical connection technology, and specifically relates to an explosion-proof junction box for automatic retractable cables. Background Technology

[0002] In the construction of industrial automation systems, instrument cables are usually pre-laid in conduits within cable trays. Instruments and meters need to be frequently connected for testing. Traditional methods require repeated disassembly and reassembly of cables, which is both time-consuming and poses a risk of short circuits.

[0003] Existing explosion-proof junction boxes are mostly fixed structures, which cannot meet the needs of dynamic debugging. Debugging faces two major pain points: First, disassembly and reassembly are inefficient. Traditional debugging requires opening the cable tray to disassemble the cables, taking an average of 25 minutes per operation, and repeated bending can easily damage the wire cores. Second, the fixed design cannot address the needs of cable expansion and contraction, leading to redundant cable accumulation and increasing the risk of short circuits. Utility Model Content

[0004] The purpose of this invention is to provide an automatic retractable cable explosion-proof junction box to solve the problems of low disassembly and reassembly efficiency and easy cable accumulation when using explosion-proof junction boxes for wiring tests in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An explosion-proof junction box for automatic retractable cables includes an explosion-proof housing, with a conduit and an explosion-proof sealing tube connected to both sides of the explosion-proof housing; a wiring device and a winding device are provided inside the explosion-proof housing.

[0007] The wiring device includes a terminal block mounting base, on which a terminal block is mounted; external cables can pass through the explosion-proof sealing tube into the explosion-proof housing and connect to the terminal block;

[0008] The winding device includes a rotating shaft that can rotate around its own central axis. A spiral spring and a winding reel are sleeved on the rotating shaft. The outer end of the spiral spring is fixedly connected to the inside of the explosion-proof housing, and the inner end of the spiral spring is fixedly connected to the rotating shaft. The inner ring of the winding reel is fixedly connected to the outer wall of the rotating shaft.

[0009] The winding reel has a cable wound up. One end of the cable extends out of the explosion-proof housing from the explosion-proof sealing tube and can be connected to an external instrument. The other end of the cable can be connected to an external cable through a terminal block.

[0010] This utility model also has the following features:

[0011] Furthermore, the take-up reel has spirally distributed grooves, and the middle part of the cable is wound inside the grooves.

[0012] It also includes a cover plate whose shape matches the winding reel, the inner wall of the cover plate being fitted to the winding reel, and the side wall of the cover plate having two openings, from which the two ends of the cable extend respectively.

[0013] Furthermore, a first gear is rotatably disposed inside the explosion-proof housing near the rotating shaft, and a second gear that meshes with the first gear is fixedly sleeved at the bottom of the rotating shaft;

[0014] A limit buckle is fixedly provided on the end face of the first gear, with one end of the limit buckle located at the central shaft of the first gear and the other end extending out of the outer ring of the first gear.

[0015] The first gear can drive the limit buckle to rotate until the other end of the limit buckle contacts the end of the inner ring of the spiral spring.

[0016] Furthermore, a sealing ring and a clamping nut are provided at one end of the conduit located in the explosion-proof housing.

[0017] Furthermore, the terminal block holder is a quick-connect type terminal block holder;

[0018] The terminal block is a spring-pressed type.

[0019] Furthermore, the terminal block holder is provided with an insulating cover.

[0020] Furthermore, the cable is a stretchable cable with a tensile length ≥ 1.5m.

[0021] Furthermore, the terminal block includes an L / N / PE three-pole interface, and the conductor cross-sectional area inside the cable is 1.5 mm². 2 .

[0022] Furthermore, it also includes a sealing plate installed inside the explosion-proof enclosure;

[0023] The cavity formed between the sealing plate and the inner wall of the explosion-proof housing is a sealing cavity; the wiring device and the winding device are both located inside the sealing cavity;

[0024] The sealing plate has a through hole, through which the cable passes and then extends out of the explosion-proof housing from the explosion-proof sealing tube.

[0025] Furthermore, the thickness of the explosion-proof housing is 4-6 mm.

[0026] Compared with the prior art, this utility model has the following technical effects:

[0027] (I) The automatic retractable cable explosion-proof junction box of this utility model has a built-in winding device to realize cable retraction. During adjustment, the cable can be directly pulled out for connection, and it can be automatically retracted after resetting, without causing redundant cable accumulation. The traditional rigid connection of "pipeline-equipment" is changed to a flexible connection of "pipeline-retractable junction box-equipment", which creates a debugging buffer; it greatly reduces the wiring and disassembly time and improves debugging efficiency.

[0028] (II) The automatic retractable cable explosion-proof junction box of this utility model can reuse the cable for work, which is economical. By limiting the cable from over-extending through the design of the limit buckle, the junction box can be disassembled and reused in the sealed cavity to realize dynamic cable retraction and extension. It breaks through the technical prejudice of traditional explosion-proof equipment with non-movable wiring, and is suitable for large-scale use and promotion in industry. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the automatic retractable cable explosion-proof junction box of this utility model;

[0030] Figure 2 This is an exploded view of the automatic retractable cable explosion-proof junction box of this utility model.

[0031] The meanings of the labels in the diagram are as follows:

[0032] 1. Explosion-proof housing; 2. Conduit; 3. Explosion-proof sealing tube; 4. Terminal block holder; 5. Spiral spring; 6. Winch; 7. Cable; 8. Cover plate; 9. Sealing plate; 10. Sealing ring. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, all components in this utility model are known components in the prior art. For example, the explosion-proof sealing tube uses a commonly known explosion-proof sealing tube.

[0034] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0035] like Figure 1 and 2 As shown, an explosion-proof junction box for automatic retractable cables includes an explosion-proof housing 1. Through holes are provided on both sides of the explosion-proof housing 1, and a conduit 2 and an explosion-proof sealing tube 3 are respectively installed in the two through holes. A wiring device and a winding device are installed inside the explosion-proof housing 1.

[0036] The wiring device includes a terminal block holder 4 and a terminal block. The terminal block is provided on the terminal block holder 4. External cables can pass through the explosion-proof sealing tube 3 into the explosion-proof housing 1 and connect to the terminal block.

[0037] It should be noted that the explosion-proof sealing tube 3 is a known component in the prior art. When wiring, the explosion-proof housing 1 needs to be opened, and the explosion-proof housing 1 can be opened and closed. The above functions are common structures known in the prior art, and those skilled in the art should know and understand how to operate them. For example, a sealing cover can be hinged to the explosion-proof housing 1 to achieve the opening and closing function. Further details will not be elaborated here.

[0038] The winding device includes a rotating shaft, which is rotatably installed inside the explosion-proof housing 1 and can rotate around its own central axis. A spiral spring 5 and a winding winch 6 are sleeved on the rotating shaft.

[0039] The end of the outer ring of the spiral spring 5 is fixedly connected to the inside of the explosion-proof housing 1, and the end of the inner ring of the spiral spring 5 is fixedly connected to the rotating shaft; the inner ring of the winding winch 6 is fixedly connected to the outer wall of the rotating shaft.

[0040] The winding winch 6 winds up a cable 7. One end of the cable 7 extends out of the explosion-proof housing 1 from the explosion-proof sealing tube 3 and can be connected to an external instrument. The other end of the cable 7 can be connected to an external cable through a terminal block.

[0041] The material of the explosion-proof housing 1 can be selected by those skilled in the art according to actual needs and conventional knowledge in the field. In the embodiment, the material of the explosion-proof housing 1 is an Ex dIIB T4 explosion-proof certified housing to achieve an IP68 protection level.

[0042] Due to the complex installation environment of instruments, when using this device for testing, the power line (signal line) of the instrument's DCS or PLC is connected to the terminal block through conduit 2, and then connected to the instrument through a cable to form a circuit for live debugging and data verification with the DCS or PLC system.

[0043] When cable 7 needs to be pulled out, the winding winch 6 rotates, causing the shaft to rotate, which in turn causes the spiral spring 5 to contract. When cable 7 needs to be retracted, the spiral spring 5 returns to its original state, thereby retracting cable 7.

[0044] As a preferred option, the take-up winch 6 has multiple spirally distributed grooves, allowing the cable 7 to enter the grooves;

[0045] It also includes a cover plate 8 whose shape matches the winding reel 6. The inner wall of the cover plate 8 fits snugly against the winding reel 6, and the cover plate 8 is fixedly installed inside the explosion-proof housing 1. The side wall of the cover plate 8 has two openings, and the two ends of the cable 7 extend out from the two openings respectively.

[0046] The cable 7 is wound inside the groove on the take-up reel 6. The cover plate 8 serves two purposes: dust prevention and protection, and preventing the cable 7 from coming out of the groove.

[0047] As a preferred embodiment, a first gear is rotatably mounted inside the explosion-proof housing 1 near the rotating shaft, and a second gear that meshes with the first gear is fixedly mounted on the bottom of the rotating shaft;

[0048] A limit buckle is fixedly provided on the end face of the first gear. One end of the limit buckle is located at the central shaft of the first gear, and the other end extends out of the outer ring of the first gear.

[0049] The first gear can drive the other end of the limit buckle to rotate until it contacts the end of the inner ring of the spiral spring 5.

[0050] In actual use, the rotation of the shaft drives the second gear to rotate, the second gear drives the first gear to rotate, and the rotation of the first gear drives the limit buckle to rotate. When the limit buckle rotates to the end of the inner ring of the spiral spring 5, it will be stuck by the end of the inner ring of the spiral spring 5 and cannot rotate anymore, thus playing a limiting role. The purpose of this is to prevent the cable 7 from being pulled out excessively.

[0051] As a preferred embodiment, the conduit 2 is provided with a sealing ring and a clamping nut at one end of the explosion-proof housing 1.

[0052] Both the sealing ring and the clamping nut are existing components in the prior art. The sealing ring enhances the sealing performance, and the clamping nut can lock or release the cable 7 by its own locking or loosening.

[0053] Specifically, the terminal block holder 4 is a quick-connect type terminal block holder;

[0054] The terminals are spring-pressed.

[0055] An insulating cover is provided on the terminal block mounting base 4.

[0056] Cable 7 is a retractable cable with a tensile length of ≥1.5m. It reduces wire consumption by 60% compared to traditional temporary wiring and can be reused at multiple commissioning points.

[0057] The terminal blocks include L / N / PE three-pole interfaces, and the conductor cross-sectional area inside cable 7 is 1.5mm². 2 The rated current of this configuration is 10A, which meets the power supply requirements of most instruments.

[0058] The thickness of the explosion-proof housing 1 is 4-6mm, which meets the requirements for thinness.

[0059] As a preferred embodiment, it also includes a sealing plate 9, and the cavity formed between the sealing plate 9 and the inner wall of the explosion-proof housing 1 is a sealing cavity; the wiring device and the winding device are both located inside the sealing cavity;

[0060] The sealing plate 9 has through holes through which cables can pass, further improving the sealing performance.

[0061] This utility model of an automatic retractable cable explosion-proof junction box has been put into use by a certain enterprise. In actual use, under the ASTM D642 standard test standard, it reduces the wiring and disassembly time by 90% and improves debugging efficiency: the single wiring time is shortened from 22.5 minutes to 3.2 minutes.

[0062] Based on 10 commissioning points, the cable 7 has a winding life of >10,000 cycles, resulting in significant economic benefits: each project reduces temporary cable costs by approximately 3,800 yuan.

[0063] Suitable for explosion-proof environments of Ex dIIB T4 rating, with a breakthrough in safety: passing the IEC 60079-1 spark test, ensuring safe operation in environments with 8% methane concentration.

Claims

1. An automatic shrink cable explosion-proof junction box comprising an explosion-proof housing (1), characterized in that; The explosion-proof housing (1) is connected to a conduit (2) and an explosion-proof sealing pipe (3) on both sides respectively; the explosion-proof housing (1) is equipped with a wiring device and a winding device inside; The wiring device includes a terminal block holder (4), on which a terminal block is installed; external cables can pass through the explosion-proof sealing tube (3) into the explosion-proof housing (1) and connect to the terminal block; The winding device includes a rotating shaft that can rotate around its own central axis. A spiral spring (5) and a winding winch (6) are sleeved on the rotating shaft. The outer end of the spiral spring (5) is fixedly connected to the inside of the explosion-proof housing (1), and the inner end of the spiral spring (5) is fixedly connected to the rotating shaft. The inner ring of the winding winch (6) is fixedly connected to the outer wall of the rotating shaft. The winding winch (6) has a cable (7) wound on it. One end of the cable (7) extends out of the explosion-proof housing (1) from the explosion-proof sealing tube (3) and can be connected to an external instrument. The other end of the cable (7) can be connected to an external cable through a terminal block.

2. The automatic pinch cable gland of claim 1, wherein, The winding reel (6) is provided with spirally distributed grooves, and the cable (7) is wound in the middle of the grooves; It also includes a cover plate (8) whose shape matches the take-up winch (6), the inner wall of the cover plate (8) is in contact with the take-up winch (6), and the side wall of the cover plate (8) is provided with two openings, from which the two ends of the cable (7) extend respectively.

3. The automatic pinch cable gland of claim 1, wherein, The explosion-proof housing (1) has a first gear rotatably mounted inside near the shaft, and a second gear meshing with the first gear is fixedly mounted on the bottom of the shaft. A limit buckle is fixedly provided on the end face of the first gear, with one end of the limit buckle located at the central shaft of the first gear and the other end extending out of the outer ring of the first gear. The first gear can drive the limit buckle to rotate until the other end of the limit buckle contacts the end of the inner ring of the spiral spring (5).

4. The automatic pinch cable gland of claim 1, wherein, The conduit (2) is provided with a sealing ring and a clamping nut at one end of the explosion-proof housing (1).

5. The automatic pinch cable gland of claim 1, wherein, The terminal block holder (4) is a quick-connect type terminal block holder; The terminal block is a spring-pressed type.

6. The automatic pinch cable gland of claim 5, wherein, An insulating cover is provided on the terminal block holder (4).

7. The automatic pinch cable gland of claim 6, wherein, The cable (7) is a stretchable cable with a stretch length ≥ 1.5m.

8. The automatic pinch cable gland of claim 7, wherein, The terminal comprises an L / N / PE three-pole interface, and the conductor cross-sectional area in the cable (7) is 1.5 mm 2 .

9. An automatic pinch cable gland as claimed in any one of claims 1 to 8, wherein, It also includes a sealing plate (9) installed inside the explosion-proof housing (1); The cavity formed between the sealing plate (9) and the inner wall of the explosion-proof housing (1) is a sealing cavity; the wiring device and the winding device are both located inside the sealing cavity; The sealing plate (9) has a through hole, through which the cable (7) passes and extends out of the explosion-proof housing (1) from the explosion-proof sealing tube (3).

10. The explosion-proof junction box for automatic retractable cables as described in claim 9, characterized in that, The thickness of the explosion-proof housing (1) is 4-6 mm.

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