Special structure cable lead-in device in junction box and manufacturing method thereof

Abstract

The application discloses a special structure cable introduction device in a junction box, which comprises a threaded sleeve, a rubber-sealed inner sleeve arranged in the threaded sleeve, a copper pipe and a rubber-sealed sleeve, the rubber-sealed sleeve is connected with the copper pipe, and an explosion-proof joint surface is formed between the threaded sleeve and the copper pipe. The application solves the problem that the motor lead cannot be installed in a narrow space, saves space, reduces cost and shortens the production cycle of the motor.

Description

Technical Field

[0001] The invention relates to the technical field of cable introduction devices, in particular to a cable introduction device with a special structure in a junction box. Background Art

[0002] Currently, the cable entry device for flameproof motors uses a terminal sleeve structure, which requires the production of molding materials. The production of molding materials requires the opening of molds, which is costly and has a long production cycle. The terminal sleeve structure is limited by the motor structure and space and cannot be installed. Summary of the Invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, the present invention proposes a cable entry device with a special structure in a junction box that occupies a small space, has a low manufacturing cost and has flameproof properties. The technical solution adopted by the present invention is:

[0005] A cable entry device with a special structure in a junction box includes a threaded outer sleeve, a rubber-sealed inner sleeve provided inside the threaded outer sleeve, the rubber-sealed inner sleeve including a copper tube and the rubber-sealed outer sleeve, the outside of the rubber-sealed outer sleeve is connected to the copper tube, and an explosion-proof joint surface is formed between the threaded outer sleeve and the copper tube.

[0006] A copper tube hoop is arranged in the rubber sealing sleeve, and the lead wire is crimped in the copper tube hoop.

[0007] The copper tube and the threaded sleeve are fixed by clamping, and the clamping mechanism includes a spring clamping ring. The upper end of the copper tube is provided with a groove, and the lower end of the copper tube is provided with a clamping seat. The upper end of the threaded sleeve is provided at the lower end of the groove, and a spring clamping ring is provided in the groove. The lower end of the threaded sleeve is in contact with the clamping seat at the lower end of the copper tube.

[0008] The manufacturing method of the cable entry device includes the following steps:

[0009] A: Strip the insulation layer from the end of the lead wire to a length of 30mm. Insert the entire stripped portion of the lead wire into the crimping joint in the cavity of the copper pipe clamp. Place the copper pipe clamp into the crimping die of the crimping pliers for crimping. The crimping pressure should be 13-16MPa, the pit depth should be no less than 4mm, and the crimping time should be no less than 3s.

[0010] B: To make the seal, mix resin CW2248 and curing agent Hy956EN in the following ratio: resin CW2248 100 parts: curing agent Hy956EN 11 parts. Place the copper pipe clamp in the middle of the copper pipe and fix it with the tooling. Inject the prepared sealant into the copper pipe from the special equipment to the specified position to complete the seal.

[0011] C: Pass the upper end of the rubber seal inner sleeve through the lower end of the threaded outer sleeve. When the groove on the upper part of the copper tube is exposed, install the spring clamp and apply Loctite glue. The assembly is complete.

[0012] The center of the pressing pit is about 8-10 mm away from the end face of the copper pipe hoop; double-sided pressing is adopted, and the centers of the two pressing pits are about 180° apart.

[0013] The copper tube hoop and the lead wire are crimped and then soldered, so that the gap between the copper tube hoop and the lead wire is filled with tin.

[0014] The beneficial effects of the present invention are: it solves the problem that the motor leads cannot be installed in a small space, can save space well, meets the explosion-proof requirements of explosion-proof motors by providing a copper tube, and uses a curing agent to form a glue-sealed inner sleeve, which saves the time of producing the terminal sleeve and opening the mold, saves costs, and shortens the production cycle of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention;

[0016] Figure 2 It is a structural diagram of a threaded jacket;

[0017] Figure 3 It is a cross-sectional view of the threaded jacket;

[0018] Figure 4 It is a schematic diagram of the structure of the copper tube;

[0019] Figure 5 It is a structural diagram of a copper pipe clamp. DETAILED DESCRIPTION

[0020] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0021] like Figure 1 As shown, the present invention is a cable entry device with a special structure for use in a junction box. It includes a rubber-sealed inner sleeve and a threaded outer sleeve 5, the outer portion of which is connected to the threaded outer sleeve 5. The rubber-sealed inner sleeve includes a copper tube 4 and a rubber-sealed sleeve 2, the outer portion of which is connected to the copper tube 4. The threaded outer sleeve 5 and the copper tube 4 form a flameproof joint surface.

[0022] A copper pipe clamp 3 is provided inside the rubber seal 2, and a pressing joint 3.1 is provided in the middle of the copper pipe clamp 3. The lead wire 1 is inserted into the pressing joint 3.1 of the copper pipe clamp 3 for crimping. The outside of the copper pipe clamp 3 is connected to the rubber seal 2, and the outside of the rubber seal 2 is connected to the copper pipe 4.

[0023] The copper tube 4 and the threaded sleeve 5 are fixed by a snap connection. The snap connection mechanism includes a spring collar 6. The threaded sleeve 5 is provided on the outside of the copper tube 4. The upper end of the copper tube 4 is provided with a groove, and the lower end of the copper tube 4 is provided with a clamping seat. The upper end of the threaded sleeve 5 is located at the lower end of the groove, and the spring collar is located in the groove. The lower end of the threaded sleeve 5 abuts against the clamping seat at the lower end of the copper tube 4.

[0024] During use, the glue-sealed inner sleeve is passed from the main cavity into the cavity of the junction box and through the threaded outer sleeve 5; the glue-sealed inner sleeve is pulled upwards so that it contacts the lower part of the threaded outer sleeve 5; the threaded outer sleeve 5 is screwed in from the junction box toward the main cavity, and Loctite glue is applied when screwing in; when the groove on the upper part of the copper tube 4 is exposed, the spring retaining ring 6 is installed and Loctite glue is applied, and the installation is completed.

[0025] Working principle: the lead wire 1 is arranged in the copper tube clamp 3, the copper tube clamp 3 is placed in the middle position of the copper tube 4, the prepared sealant is injected into the copper tube 4 to form a seal inner sleeve, the outside of the copper tube 4 is connected to a threaded outer sleeve 5, and a flameproof joint surface is formed between the copper tube 4 and the threaded outer sleeve 5.

[0026] A method for manufacturing a cable entry device includes the following steps:

[0027] A: Strip the insulation layer from the end of lead wire 1 to a length of 30 mm (greater than 20 mm, in accordance with the provisions of Appendix C.1.3 of GB3836.2-2010). Insert the entire stripped portion of lead wire 1 into the crimping port 3.1 in the cavity of the copper tube clamp 3. Place the copper tube clamp 3 into the die of the crimping pliers and crimp it. The crimping pressure should be 13-16 MPa, the dent depth should be no less than 4 mm, and the crimping time should be no less than 3 seconds.

[0028] B: To make the sealant, mix resin CW2248 and curing agent Hy956EN in the following ratio: resin CW2248 100g: curing agent Hy956EN 11g. Place the copper pipe clamp 3 in the middle of the copper pipe 4 and fix it using a tool (existing technology). Inject the prepared sealant into the copper pipe using a dedicated device to the specified position to complete the sealant production.

[0029] C: Pass the rubber seal inner sleeve through the threaded outer sleeve 5. When the groove on the upper part of the copper tube 4 is exposed, install the spring clamp 6 and apply Loctite glue. The assembly is completed.

[0030] The sealant needs to cure at room temperature, typically at 35°C for 2 hours, 20°C for 5 hours, or 15°C for 12 hours. The CW2248 resin has a continuous operating temperature (COT) lower limit below the motor's minimum operating temperature and an upper limit at least 20°C above the maximum operating temperature. The sealant also exhibits sufficient thermal stability (in compliance with the test requirements for adhesive materials in Chapter 12 of GB3836.1-2010).

[0031] After the sealant sealant is cured, a withstand voltage test is conducted on the lead wires. The rated voltage is 1140V. The lead wires of the sealant sealant are subjected to a withstand voltage test between the lead wires and the sealant sealant for 1 minute. No flickering or breakdown should occur. The test voltage is 3.5kV. A water pressure test is also conducted. No leakage should occur between the sealant material and the lead wires during the test.

[0032] The center of the pressure pit is about 8-10mm away from the end face of the copper pipe clamp. Double-sided pressure is used, and the centers of the two pressure pits are about 180° apart. The lead-in cable should be firmly connected and must not be loose or pulled off. After the crimping is completed, it should be inspected. When checking, use both hands to hold the lead-in cable separately, slowly rotate it while pulling hard, and ensure that the crimped part is not loose or disconnected.

[0033] The copper tube hoop 3 is crimped onto the lead wire and then soldered to fill the gap between the copper tube hoop 3 and the lead wire with tin.

[0034] The present invention solves the problem that the motor leads cannot be installed in a small space, can save space well, meets the explosion-proof requirements of explosion-proof motors by providing a copper tube, and uses a curing agent to form a glue-sealed inner sleeve, which saves the time of producing the terminal sleeve and opening the mold, saves costs, and shortens the production cycle of the motor.

[0035] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications are possible without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the claimed invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0036] In the description of the present invention, it should be understood that the terms "front", "rear", "left", "right", "center", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the protection content of the present invention.

Claims

1. A method for manufacturing a special structure cable entry device in a junction box, characterized in that: The cable entry device includes a threaded outer sleeve, a rubber-sealed inner sleeve provided in the threaded outer sleeve, the rubber-sealed inner sleeve including a copper tube and the rubber-sealed outer sleeve, the outer portion of the rubber-sealed outer sleeve is connected to the copper tube, and a flameproof joint surface is formed between the threaded outer sleeve and the copper tube; The preparation method comprises the following steps: A: Strip the insulation layer from the end of the lead wire to a length of 30mm. Insert the entire stripped portion of the lead wire into the crimping joint in the cavity of the copper pipe clamp. Place the copper pipe clamp into the crimping die of the crimping pliers for crimping. The crimping pressure should be 13-16MPa, the pit depth should be no less than 4mm, and the crimping time should be no less than 3s. B: To make the sealant, mix resin CW2248 and curing agent Hy956EN in the following ratio: resin CW2248 100 parts: curing agent Hy956EN 11 parts. Place the copper pipe clamp in the middle of the copper pipe and fix it with a tool. Use the special equipment to inject the prepared sealant into the copper pipe to the specified position to complete the sealant. C: Pass the upper end of the rubber seal inner sleeve through the lower end of the threaded outer sleeve. When the groove on the upper part of the copper tube is exposed, install the spring clamp and apply Loctite glue. The assembly is complete.

2. The method for manufacturing a cable entry device with a special structure in a junction box according to claim 1, characterized in that: A copper tube hoop is arranged in the rubber sealing sleeve, and the lead wire is crimped in the copper tube hoop.

3. The method for manufacturing a special structure cable entry device in a junction box according to claim 2, characterized in that: The copper tube and the threaded sleeve are fixed by clamping, and the clamping mechanism includes a spring clamping ring. The upper end of the copper tube is provided with a groove, and the lower end of the copper tube is provided with a clamping seat. The upper end of the threaded sleeve is provided at the lower end of the groove, and a spring clamping ring is provided in the groove. The lower end of the threaded sleeve is in contact with the clamping seat at the lower end of the copper tube.

4. The method for manufacturing a cable entry device with a special structure in a junction box according to claim 1, characterized in that: The center of the pressing pit is 8-10 mm away from the end face of the copper pipe hoop; double-sided pressing is adopted, and the angle between the centers of the two pressing pits is 180°.

5. The method for manufacturing a cable entry device with a special structure in a junction box according to claim 1, characterized in that: The copper tube hoop and the lead wire are crimped and then soldered, so that the gap between the copper tube hoop and the lead wire is filled with tin.

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