Explosion-proof overtemperature and overcurrent protection device sealing structure

Abstract

An explosion-proof over-temperature and overcurrent protection device sealing structure, comprising, in order from the inside out, an over-temperature and overcurrent protection device (2), an explosion-proof potting compound (5), a switching contact protection housing (4) and an outer protective housing (6), wherein the outer protective housing (6) is a relatively enclosed housing, fully enclosing the explosion-proof potting compound (5), and further comprising a cable (1) electrically connected to the over-temperature and overcurrent protection device (2), wherein the outer protective housing (6) is provided with a cable outlet bore (8), and wherein the edge of the cable outlet bore (8) is provided with an inwardly rounded corner.

Description

TECHNICAL AREA The present invention relates to overtemperature and overcurrent protection devices and in particular to an explosion-proof sealing structure for overtemperature and overcurrent protection devices. STATE OF THE ART A large number of electrical instruments are used in manufacturing. Electrical sparks from all kinds of friction, mechanical wear, static electricity, high temperatures, etc., are unavoidable, especially when instruments and electrical equipment fail. Many industrial sites have objectively explosive conditions. If the concentration of explosive substances in a mixture with oxygen is within the explosive limit, an explosion will occur if an explosive source is present; therefore, it is essential to implement explosion protection measures at industrial sites. To address the efficiency problem during assembly, state-of-the-art explosion-proof products do not have complete outer casing protection, leaving the encapsulated material partially exposed to the environment. Currently available encapsulated materials offer good thermal stability but poor UV resistance. Existing explosion-proof products cannot be used directly in UV-exposed environments. Chinese utility model no. CN 201 117 566 Y, filed on November 7, 2007, discloses a thermal melting element comprising a fusible element coated with low-temperature resin, each end of which is welded to a connecting pin, wherein the end of the connecting pins welded to the fusible element is provided with several bends, these bends of the connecting pins together with the fusible element are inserted into a housing, wherein the bends of the connecting pins rest against the inner wall of the housing and are joined to form an integral by potting compound cast into the housing. International patent publication no. WO 2005 / 025 285 A1, filed on 30 July 2004, discloses a protective device for electronic components, in particular memory modules, in which the electronic component(s) is / are embedded in a first protective shell (2) on a mineral basis with antifreeze water, encapsulated in silicone, and a second protective shell (1) containing a ceramic casting compound may be provided. Chinese utility model no. CN 212 648 132 U, filed on September 7, 2020, discloses an over-temperature and overcurrent protection device whose interior is permanently bonded to an epoxy resin layer, wherein a current input terminal is inserted into the epoxy resin layer. The current input terminal comprises a first printed circuit board, a static contact plate, and a plastic connector, wherein one end of the first printed circuit board is permanently bonded to the static contact plate and the first printed circuit board is inserted inside the plastic connector. Chinese patent publication no. CN 104 217 896 A, filed on September 15, 2014, discloses a built-in overcurrent and overtemperature protection device comprising a metal housing with a bottom opening, a metal base sealing the bottom opening of the metal housing, a thermal bimetallic plate provided with a movable contact that reverses when a predetermined temperature is reached and resets when the temperature falls below the predetermined temperature, a static contact arranged corresponding to the movable contact, a resistance heating wire, and two connecting pins. The upper ends of each of the two connecting pins penetrate the metal base and extend into the space sealed by the metal housing and the metal base.The static contact is permanently installed at the top of one terminal pin, and one end of the resistance heating wire is permanently installed at the top of the other terminal pin, while the other end of the resistance heating wire is permanently connected to the metal base. The space is filled with a gas mixture. German patent application DE 198 52 189 A1, filed on November 12, 1998, discloses a cable connection module for connecting a sensor / actuator unit located in potentially explosive atmospheres to a non-intrinsically safe circuit. The module comprises a housing (12), at least two input lines (14), and several output lines (16). The output lines (16) can be connected to the sensor / actuator unit, and the input lines (14) serve as a non-intrinsically safe power supply to the device. A current / voltage limiting device (18) is arranged in the housing (12) between the input lines (14) and the output lines (16). CONTENT OF THE PRESENT INVENTION The present invention overcomes the shortcomings of the prior art and creates an explosion-proof over-temperature and over-current protection device sealing structure; its structure is more reliable, no longer breaks or causes damage and potential explosion hazards; the reliability of operation is more long-term; the temperature sensing is more accurate; and the quality is more excellent. To solve the above technical problems, the present invention is solved by the following technical solution: an explosion-proof over-temperature and overcurrent protection device sealing structure comprising, in order from the inside out, an over-temperature and overcurrent protection device, an explosion-proof potting compound, a switching contact protection housing, and an outer protective housing, wherein the outer protective housing is a relatively closed housing, completely enclosing the explosion-proof potting compound, and further comprising a cable electrically connected to the over-temperature and overcurrent protection device, wherein the outer protective housing is provided with a cable outlet bore, and wherein the edge of the cable outlet bore has an inwardly rounded corner. Furthermore, one end of the switching contact protection housing is open and another end of the switching contact protection housing is closed, wherein one end of the outer protection housing pointing away from the cable outlet bore is open, wherein the open end of the outer protection housing is further provided with a housing end cap, wherein the switching contact protection housing is provided with a first bolt bore, wherein the outer protection housing is provided with a second bolt bore, wherein the housing end cap is provided with a third bolt bore, wherein the first bolt bore, the second bolt bore and the third bolt bore are aligned during assembly and are fixed by a fixing pin. Furthermore, the switching contact protection housing is provided with an extension, wherein the housing end cap is provided with a locking bore, the locking bore interacting with the extension, so that the switching contact protection housing is in snap-fit ​​connection with the housing end cap. Furthermore, the cable includes a positive conductor and a negative conductor, with the positive conductor and the negative conductor each bypassing the over-temperature and over-current protection devices on both sides. Furthermore, the switching contact protection housing consists of a thermally conductive ceramic material. Furthermore, the switching contact protection housing consists of a ceramic material with a thermal conductivity greater than 15W / m·K. Furthermore, the diameter of the cable outlet hole is slightly larger than the cross-section of the cable. Furthermore, a cable passage point projecting outwards is provided in the middle on one side of the switch contact protection housing, whereby the outer protection housing is also provided with a corresponding outwards projecting groove corresponding to the cable passage point. Furthermore, the outer protective housing is provided with a fourth bolt hole, with a positioning pin provided within the fourth bolt hole. Furthermore, a glue injection hole and an exhaust hole are provided at the end of the outer protective housing which is equipped with a cable outlet hole. In comparison to the prior art, the present invention has the following effects: An explosion-proof over-temperature and over-current protection device sealing structure, comprising, in order from the inside out, an over-temperature and over-current protection device, an explosion-proof potting compound, a switching contact protection housing, and an outer protective housing, wherein the outer protective housing is a relatively closed housing, wherein the explosion-proof potting compound is completely enclosed so that ultraviolet radiation does not irradiate it and it can be used directly in the vicinity of ultraviolet radiation, and it further comprises a cable that is electrically connected to the over-temperature and over-current protection device, wherein the outer protective housing is provided with a cable outlet bore, and wherein the edge of the cable outlet bore is provided with an inwardly rounded corner.This protects the cable insulation layer from damage caused by sharp edges, thus increasing the reliability of the product. In summary, the product structure is more reliable, the temperature measurement precision is higher, the quality is more stable, the service life is longer, the use is more convenient, economical and practical, the assembly time is significantly reduced, and production efficiency and product quality are improved. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings serve to further understand the present invention, are used in conjunction with embodiments of the invention to explain the invention, and do not represent a limitation of the invention as shown in the accompanying drawings: Fig. 1 is a perspective exploded view of an explosion-proof overtemperature and overcurrent protection device sealing structure of the present invention. Fig. 2 is a schematic structural view of an angle of an explosion-proof overtemperature and overcurrent protection device sealing structure of the present invention. Fig. 3 is a schematic structural view in section at AA in Fig. 2. Fig. 4 is a schematic structural view in section at BB in Fig. 2. In the figures: 1 Cable 2 Over-temperature and overcurrent protection device 3 Fixing pin 4 Switch contact protection housing 5 Explosion-proof potting compound 6 Outer protective housing 7 Temperature sensing surface 8 Cable outlet hole 9 Electrically charged switch terminal 10 Positive and negative conductors 11 Cable entry point 12 Groove 13 Housing end cap 14 First bolt hole 15 Second bolt hole 16 Third bolt hole 17 Extension 18 Positioning pin 19 Fourth bolt hole 20 Detent hole 21 Glue injection hole 22 Exhaust hole DETAILED DESCRIPTION Preferred embodiments of the present invention are described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described here serve only to illustrate and explain the present invention without limiting the invention. As shown in Figs. 1-4, an explosion-proof over-temperature and overcurrent protection device sealing structure comprises, from the inside out, an over-temperature and overcurrent protection device 2, an explosion-proof potting compound 5, a switching contact protection housing 4, and an outer protective housing 6. The switching contact protection housing 4 is made of a thermally conductive ceramic material with a thermal conductivity greater than 15 W / m·K. As shown in Fig. 4, the switching contact protection housing 4 within the explosion-proof over-temperature and overcurrent protection device 2 is made of a ceramic material with a thermal conductivity greater than 15 W / m·K, resulting in faster temperature transfer from the outer temperature-sensing surface 7 to the inner temperature-sensing element and higher temperature sensing accuracy.Furthermore, ceramic is a material with very good heat resistance and electrical insulation. This encompasses a wide range of thermally conductive ceramic materials and is not limited to a specific type. As shown in Fig. 3, it further comprises a cable 1 electrically connected to the over-temperature and overcurrent protection device 2, wherein the cable 1 comprises a positive conductor and a negative conductor 10, the positive conductor and the negative conductor 10 each being routed around the over-temperature and overcurrent protection device 2 on both sides. The two wires are separated by a thermostat housing to ensure faster heat dissipation, and the wire insulation layer is encased externally with an insulating, explosion-proof potting compound 5 to ensure the safety of the insulation. As shown in Fig.As shown in Fig. 1-2, an outwardly projecting cable entry point 11 is provided in the center on one side of the switching contact protection housing 4, with the outer protection housing 6 also having a corresponding outwardly projecting groove 12 corresponding to the cable entry point 11. The cable entry point 11 is designed so that the entire protector can be made thinner, except at the cable entry point 11, which is made larger according to the size of the cable 1. This allows for miniaturization of the entire product. As shown in Fig. 1, after the groove 12 of the outer protection housing 6 has been aligned with the cable entry point 11 during assembly, the cable entry point 11 slides into the groove 12 when the switching contact protection housing 4 is installed in the outer protection housing 6, which can play a role in positioning and improve assembly efficiency. As shown in Fig. 3 and Fig.As shown in Fig. 4, the outer protective housing 6 is a relatively closed housing, with the explosion-proof potting compound 5 being completely enclosed so that ultraviolet radiation does not reach it and it can be used directly in the vicinity of ultraviolet radiation. As shown in Fig. 1, Fig. 3 and Fig. 4, one end of the switching contact protection housing 4 is open and another end of the switching contact protection housing 4 is closed, with one end of the outer protective housing 6 pointing away from the cable outlet bore 8 being open, and the open end of the outer protective housing 6 being further provided with a housing end cap 13. As shown in Fig.Figure 1 shows the switching contact protection housing 4 provided with a first bolt bore 14, the outer protective housing 6 provided with a second bolt bore 15, and the housing end cap 13 provided with a third bolt bore 16. The first bolt bore 14, the second bolt bore 15, and the third bolt bore 16 are aligned during assembly and secured by a locking pin 3. The switching contact protection housing 4 is provided with a projection 17, the housing end cap 13 being provided with a detent bore 20. The detent bore 20 engages with the projection 17, so that the switching contact protection housing 4 is snap-fit ​​to the housing end cap 13. The outer protective housing 6 is provided with a fourth bolt bore 19, within which a positioning pin 18 is provided. This pin serves to limit the position of the switching contact protection housing 4. As shown in Figs. 2 and 4, the outer protective housing 6 is provided with a cable outlet bore 8, the diameter of which is slightly larger than the cross-section of the cable 1. The cable 1 is reliably secured to prevent damage to the product due to loosening and to improve product quality. The edge of the cable outlet bore 8 has an inwardly rounded corner. This protects the insulation layer of the cable 1 from damage by a sharp edge, thus increasing the product's reliability. Furthermore, a glue injection bore 21 and a vent bore 22 are provided at the end of the outer protective housing 6 with the cable outlet bore 8. These are used for filling and venting the explosion-proof potting compound 5 into the outer protective housing 6. As shown in Figs. 1-4, the positive and negative leads 10 of cable 1 are first connected to the two electrically charged switching terminals 9 of the over-temperature and overcurrent protection device 2 during assembly, ensuring that the positive and negative leads 10 are bypassed by the over-temperature and overcurrent protection device 2 on both sides. The connected cable 1 and the over-temperature and overcurrent protection device 2 are installed in the switching contact protection housing 4. Cable 1 passes through the cable outlet bore 8 of the outer protective housing 6. The switching contact protection housing 4 snaps into place with the housing end cap 13. The positioning pin 18 is inserted into the fourth bolt bore 19. The switching contact protection housing 4 is inserted through the open end of the outer protective housing 6. The groove 12 of the outer protective housing 6 is aligned with the cable entry point 11.The cable entry point 11 slides in the groove 12 of the outer protective housing 6 until one end of the switching contact protection housing 4 is connected to the positioning pin 18. At this point, the first bolt hole 14, the second bolt hole 15, and the third bolt hole 16 are aligned. The fixing pin 3 is inserted into the second bolt hole 15 and simultaneously passes through the first bolt hole 14 and the third bolt hole 16, securing the entire overtemperature and overcurrent protection device 2. Liquid explosion-proof potting compound 5 is injected from the glue injection hole 21 into the outer protective housing 6, and the internal air is discharged through the exhaust hole 22 during the injection of the adhesive. The assembly is complete after the explosion-proof potting compound 5 has cooled and solidified. In summary, the product structure is more reliable, the temperature measurement precision is higher, the quality is more stable, the service life is longer, the use is more convenient, economical and practical, the assembly time is significantly reduced, and production efficiency and product quality are improved.

Claims

An explosion-proof over-temperature and overcurrent protection device sealing structure, comprising, in order from the inside out, an over-temperature and overcurrent protection device (2), an explosion-proof potting compound (5), a switching contact protection housing (4) and an outer protective housing (6), wherein the outer protective housing (6) is a relatively enclosed housing, fully enclosing the explosion-proof potting compound (5), and further comprising a cable (1) electrically connected to the over-temperature and overcurrent protection device (2), wherein the outer protective housing (6) is provided with a cable outlet bore (8), and wherein the edge of the cable outlet bore (8) is provided with an inwardly rounded corner. The explosion-proof overtemperature and overcurrent protection device sealing structure according to claim 1, characterized in that one end of the switching contact protection housing (4) is open and another end of the switching contact protection housing (4) is closed, wherein an end of the outer protection housing (6) pointing away from the cable outlet bore (8) is open, wherein the open end of the outer protection housing (6) is further provided with a housing end cap (13), wherein the switching contact protection housing (4) is provided with a first bolt bore (14), wherein the outer protection housing (6) is provided with a second bolt bore (15), wherein the housing end cap (13) is provided with a third bolt bore (16), wherein the first bolt bore (14), the second bolt bore (15) and the third bolt bore (16) are aligned during assembly and are fixed by a fixing pin (3). The explosion-proof over-temperature and over-current protection device sealing structure according to claim 2, characterized in that the switching contact protection housing (4) is provided with a projection (17), wherein the housing end cap (13) is provided with a locking bore (20), wherein the locking bore (20) interacts with the projection (17) so that the switching contact protection housing (4) is in snap-fit ​​connection with the housing end cap (13). The explosion-proof over-temperature and over-current protection device sealing structure according to one of claims 1 - 3, characterized in that the cable (1) comprises a positive line and a negative line (10), wherein the positive line and the negative line (10) are each bypassed around the over-temperature and over-current protection device (2) from both sides. The explosion-proof overtemperature and overcurrent protection device sealing structure according to one of claims 1 - 3, characterized in that the switching contact protection housing (4) is made of a thermally conductive ceramic material. The explosion-proof over-temperature and over-current protection device sealing structure according to claim 5, characterized in that the switching contact protection housing (4) is made of a ceramic material with a thermal conductivity greater than 15W / m·K. The explosion-proof over-temperature and over-current protection device sealing structure according to claim 1, characterized in that the hole diameter of the cable outlet bore (8) is slightly larger than the cross-section of the cable (1). The explosion-proof over-temperature and over-current protection device sealing structure according to claim 1, characterized in that an outwardly projecting cable passage point (11) is provided in the middle on one side of the switching contact protection housing (4), wherein the outer protective housing (6) is also provided with a corresponding outwardly projecting groove (12) corresponding to the cable passage point (11). The explosion-proof overtemperature and overcurrent protection device sealing structure according to claim 1, characterized in that the outer protective housing (4) is provided with a fourth bolt bore (19), wherein a positioning pin (18) is provided within the fourth bolt bore (19). The explosion-proof overtemperature and overcurrent protection device sealing structure according to claim 1, characterized in that a glue injection bore (21) and an exhaust bore (22) are further provided at the end of the outer protective housing (6) which is provided with a cable outlet bore (8).

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