A single-cavity explosion-proof electromagnetic relay

Abstract

This invention provides a single-cavity explosion-proof electromagnetic relay, comprising a base plate, a coil support on one side of the base plate, a coil mounted in the coil support, an adsorption plate above the coil support for contacting normally open or normally closed contacts, normally open, normally closed, and other contacts integrated into the base plate, a contact heat-conducting plate embedded within the base plate for contacting the normally open or normally closed contacts, and the upper and lower ends of the coil respectively contacting the coil heat-conducting plate; an inner sleeve connected to the base plate is provided outside the coil support, an outer sleeve is provided outside the inner sleeve, and a support grid is provided inside the outer sleeve, forming a gap between the inner sleeve and the outer sleeve for resin casting; heat dissipation fins are bolted to the outside of the movable cover. This invention maintains excellent explosion-proof performance while ensuring heat dissipation performance, achieving a balance between the two and meeting the requirements for use in a single explosion-proof cavity.

Description

Technical Field

[0001] This utility model belongs to the field of explosion-proof relay technology, and in particular relates to a single-cavity explosion-proof electromagnetic relay. Background Technology

[0002] Electromagnetic relays are widely used in the electrical field. In hazardous environments containing flammable and explosive gases or dust, explosion-proof electromagnetic relays are crucial. Existing explosion-proof relays, in pursuit of reliable explosion-proof performance, generally employ an integral sealed structure or traditional potting process, but these methods have the following drawbacks:

[0003] While sealing and potting structures can effectively prevent internal electrical activities from contacting external flammable and explosive substances, existing relays struggle to balance heat dissipation and explosion protection. During relay operation, heat is inevitably generated due to core hysteresis loss, current passing through coils, and contacts. If the potting layer is too thick, heat dissipation efficiency will decrease significantly, affecting the performance and lifespan of the electronic components in the relay. On the other hand, if it is too thin, it cannot be used in single-cavity products (such as single-cavity explosion-proof control boxes) and cannot meet their explosion-proof requirements. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a single-cavity explosion-proof electromagnetic relay, and the technical solution adopted is as follows:

[0005] A single-cavity explosion-proof electromagnetic relay includes a base plate, a coil support on one side of the base plate, a coil installed in the coil support, an adsorption plate above the coil support that contacts normally open or normally closed contacts, normally open, normally closed and other contacts are integrated in the base plate, a contact heat-conducting plate embedded in the base plate that contacts normally open or normally closed contacts, and the upper and lower ends of the coil respectively contact the coil heat-conducting plate.

[0006] An inner sleeve connected to the substrate is provided on the outside of the coil support, an outer sleeve is provided on the outside of the inner sleeve, and a support grid is provided on the inside of the outer sleeve. A gap for resin pouring is formed between the inner sleeve and the outer sleeve. Heat dissipation fins are installed on the outside of the movable cover by bolts.

[0007] Furthermore, the outer sleeve adopts a split assembly structure. A movable cover is provided on one side of the heat-conducting plate in the outer sleeve. During installation, the inner sleeve, coil assembly, heat-conducting plate and base plate can be pre-assembled first, and then the outer sleeve can be assembled through the detachable connection of the movable cover, which can avoid rigid interference between the heat-conducting plate and the outer sleeve.

[0008] Furthermore, the movable cover has openings for the outer ends of the coil heat-conducting plate and the contact heat-conducting plate to be exposed. After the movable cover is installed, the outer ends of the coil heat-conducting plate and the contact heat-conducting plate are exposed 1-2mm above the surface of the movable cover, ensuring that sufficient pressure is formed between the outer ends of the heat-conducting plate and the contact surface of the heat dissipation fins.

[0009] Furthermore, a slot is provided in the inner sleeve for the coil heat-conducting plate to pass through. The shape of the slot matches the cross-sectional profile of the coil heat-conducting plate to ensure that the heat-conducting plate is in close contact with the inner wall of the inner sleeve when it passes through, thus preventing the filling resin from flowing into the inner sleeve.

[0010] Furthermore, the rear side of the heat dissipation fins is in close contact with the outer end face of the coil heat-conducting plate and the contact heat-conducting plate, and thermally conductive silicone is applied at their connection points; furthermore, thermally conductive silicone is applied at the upper and lower ends of the coil heat-conducting plate and the coil frame, as well as at the connection points of the contact heat-conducting plate and the normally open / normally closed contacts.

[0011] Furthermore, the coil heat-conducting plate has a U-shaped structure tilted at 90 degrees. This U-shaped structure can simultaneously adhere to the metal surface of the coil frame from both the top and bottom ends, forming a symmetrical heat conduction path and avoiding temperature gradients caused by single-point heat conduction. The contact heat-conducting plate has a T-shaped structure tilted at 90 degrees. The horizontal arm of the T-shaped structure is parallel to the heat dissipation fins, which can increase the contact area with the heat dissipation fins. The vertical section of the T-shape is provided with a groove for the contact to be inserted, which can increase the contact area with the contact and prevent poor contact caused by vibration.

[0012] Furthermore, the coil frame, coil heat-conducting plate, and contact heat-conducting plate are all made of alumina plates that have undergone insulation treatment. These alumina plates are low in cost, have strong thermal conductivity, and their surfaces are treated with oxidation or sprayed with an insulating coating, which can meet the high-voltage isolation requirements inside the relay and prevent short circuits in the coil caused by the metal frame.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. This utility model uses an insulated alumina plate as the coil frame, coil heat-conducting plate, and contact heat-conducting plate. The alumina plate has excellent thermal conductivity, which can quickly conduct the heat generated by the hysteresis loss of the iron core, the heat generated by the current passing through the coil, and the heat generated by the current passing through the normally open / normally closed contacts to the external heat dissipation fins. By increasing the heat dissipation area, the heat dissipation fins can accelerate the heat exchange with the surrounding air, so that the heat can be quickly dissipated into the environment, ensuring that the relay works stably within the normal temperature range and effectively avoiding problems such as performance degradation and shortened life due to overheating.

[0015] 2. This utility model, through its single-cavity sealed structure design, combined with an inner sleeve, filled resin, and an outer sleeve three-layer protective structure, can effectively prevent internal electric sparks and arcs from contacting external flammable and explosive gases. While ensuring heat dissipation performance, it still maintains excellent explosion-proof performance, achieving a balance between the two and meeting the requirements for use in a single explosion-proof cavity.

[0016] 3. The outer sleeve of this utility model adopts a split assembly structure and is equipped with a movable cover, which facilitates the installation of the coil heat-conducting plate and the contact heat-conducting plate; the components are connected by bolts and other means, and the assembly process is clear and simple, which helps to improve production efficiency and reduce production costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the installation structure of the inner sleeve of this utility model;

[0018] Figure 2 This is a schematic diagram of the installation structure of the heat-conducting plate of this utility model;

[0019] Figure 3 This is a schematic diagram of the assembly structure of the outer sleeve of this utility model;

[0020] Figure 4 This is a schematic diagram of the gap between the outer sleeve and the substrate of this utility model;

[0021] Figure 5 This is a schematic diagram showing the connection state between the coil heat-conducting plate and the coil of this utility model;

[0022] Figure 6 This is a schematic diagram of the installation structure of the heat-conducting plate with internal contacts on the substrate of this utility model.

[0023] Figure 7 This is a schematic diagram of the overall structure of the present invention after assembly.

[0024] In the picture:

[0025] 1-Baseboard, 2-Coil bracket, 21-Coil, 22-Adsorption plate, 3-Inner sleeve, 4-Coil heat-conducting plate, 5-Contact heat-conducting plate, 6-Outer sleeve, 61-Modible cover, 62-Support grid, 7-Heat dissipation fins, 8-Resin. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] As attached Figure 1-7 As shown.

[0028] A single-cavity explosion-proof electromagnetic relay includes a base plate 1. A coil support 2 is provided on one side of the base plate 1, and a coil 21 is installed in the coil support 2. The frame of the coil 21 is made of metal plate, preferably an alumina plate that has undergone insulation treatment. An adsorption plate 22 is provided above the coil support 2. When the coil 21 is energized, the iron core inside the coil 21 is magnetized, thereby attracting the adsorption plate 22 above to swing downward, so that the adsorption plate 22 is connected to the normally open contact. When the coil 21 is de-energized, the iron core inside the coil 21 loses its magnetism, and the adsorption plate 22 returns to its original position under the action of the rear tension spring, thereby disconnecting the adsorption plate 22 from the normally open contact and restoring the connection with the normally closed contact.

[0029] Furthermore, all types of contacts in the relay are embedded in the substrate 1, and a contact heat-conducting plate 5 that contacts the normally open or normally closed contacts is embedded in the substrate 1; the upper and lower ends of the frame in the coil 21 are respectively in contact with the coil heat-conducting plate 4.

[0030] The structure of the coil 21 and the principle of electromagnetic attraction and reset are basic common technologies of electromagnetic relays. They are highly mature and widely used in the electrical field. The above description of the coil 21 mainly points out that the coil frame used in this technical solution is a metal frame. The metal frame, the coil heat-conducting plate 4 and the contact heat-conducting plate are all made of aluminum oxide plates that have been insulated. The aluminum oxide plates have good thermal conductivity and can effectively conduct the heat generated by the hysteresis loss of the iron core, the heat generated by the current passing through the coil and the heat generated by the current passing through the normally open / normally closed contacts.

[0031] An inner sleeve 3, which is connected to the substrate 1, is provided on the outside of the coil support 2, as shown in the attached figure. Figure 1 , 2 As shown, the substrate 1 and the inner sleeve 3 are connected by bolts, and the inner sleeve 3 has a slot for the coil heat-conducting plate 4 to pass through.

[0032] The coil heat-conducting plate 4 has a U-shaped structure, as shown in the attached figure. Figure 2 As shown, the coil heat-conducting plate 4 is inclined at 90 degrees, and the rear end of the coil heat-conducting plate 4 is flat, which can better connect with the external heat dissipation fins 7; the contact heat-conducting plate 5 has a T-shaped structure inclined at 90 degrees.

[0033] An outer sleeve 6 is provided on the outside of the inner sleeve 3, and a support grid 62 is provided on the inside of the outer sleeve 6. The inner sleeve 3 can be snapped into the center of the outer sleeve 6 through the support grid 62, and a gap for pouring resin 8 is formed between the inner sleeve 3 and the outer sleeve 6.

[0034] Furthermore, to facilitate the installation of the coil heat-conducting plate 4 and the contact heat-conducting plate 5, the outer sleeve 6 adopts a split assembly structure. A movable cover 61 is provided on one side of the heat-conducting plate within the outer sleeve 6. The movable cover 61 is connected to the outer sleeve 6 by bolts, and an opening is provided inside the movable cover 61 for the outer ends of the coil heat-conducting plate 4 and the contact heat-conducting plate 5 to be exposed. The specific structure is shown in the attached figure. Figure 3 As shown.

[0035] After the movable cover 61 is installed, the outer ends of the coil heat-conducting plate 4 and the contact heat-conducting plate 5 protrude 1-2mm from the surface of the movable cover 61; heat dissipation fins 7 are installed on the outside of the movable cover 61 by bolts, and the rear side of the heat dissipation fins 7 is in close contact with the outer end face of the coil heat-conducting plate 4 and the contact heat-conducting plate 5, and thermally conductive silicone is applied at their connection.

[0036] The coil 21 used is an existing product and can be purchased directly from the market. Note that the purchased coil frame should be metal. The assembly process of this device is as follows: connect the inner sleeve 3 to the base plate 1. After the two are connected, pass the coil heat-conducting plate 4 through the hole slot opened on the inner sleeve 3 so that the coil heat-conducting plate 4 contacts the upper and lower ends of the frame in the coil 21. At the same time, install the contact heat-conducting plate 5 in the base plate 1 so that it contacts the normally open or normally closed contacts.

[0037] As attached Figure 3 As shown, the assembled components are installed into the outer sleeve 6. The movable cover 61 is then connected to the outer sleeve 6 using bolts. When connecting, it is important to ensure that the opening in the movable cover 61 corresponds to the outer end of the coil heat-conducting plate 4 and the contact heat-conducting plate 5, so that the outer ends of the coil heat-conducting plate 4 and the contact heat-conducting plate 5 protrude 1-2mm from the surface of the movable cover 61.

[0038] Furthermore, a grid is also provided on the inner side of the movable cover 61. After the movable cover 61 is connected to the outer sleeve 6, the inner sleeve 3 can be inserted into the center of the outer sleeve 6. At this time, a gap for pouring resin 8 will be formed between the inner sleeve 3 and the outer sleeve 6.

[0039] Furthermore, heat dissipation fins 7 are installed on the outside of the movable cover 61 by bolts, and thermally conductive silicone is applied to the connection between the rear side of the heat dissipation fins 7 and the outer end face of the coil heat-conducting plate 4 and the contact heat-conducting plate 5 to ensure tight contact. Thermally conductive silicone is also applied to the upper and lower ends of the coil heat-conducting plate and the coil frame, as well as to the connection between the contact heat-conducting plate and the normally open / normally closed contacts, which can effectively fill the gap between the coil frame / contacts and the heat-conducting plate and effectively increase the contact area.

[0040] Finally, resin 8 is poured into the gap between the inner sleeve 3 and the outer sleeve 6 to complete the assembly of the single-cavity explosion-proof electromagnetic relay; furthermore, the gap between the inner sleeve 3 and the outer sleeve 6 (i.e., the pouring thickness) is greater than or equal to 3mm.

[0041] The working principle of this device is as follows: During the operation of the relay, the heat generated by the hysteresis loss of the iron core, the heat generated by the current passing through the coil, and the heat generated by the current passing through the normally open / normally closed contacts will be conducted away through the coil frame made of insulated alumina plate, the coil heat-conducting plate 4, and the contact heat-conducting plate 5.

[0042] Heat is conducted to the heat dissipation fins 7, which, by increasing the heat dissipation area, accelerate heat exchange with the surrounding air and dissipate heat into the environment, ensuring that the relay operates stably within the normal temperature range and preventing performance degradation or even safety issues due to overheating. Simultaneously, the single-cavity sealed structure, combined with resin casting and other processes, effectively isolates internal electrical activity from the external flammable and explosive environment, ensuring explosion-proof performance.

[0043] Because of the working method of the coil, the driving voltage does not need to be very high, and the heat generated by the contacts is low. Therefore, there is no need to set a heat-conducting plate on the contacts connected to the coil. In the adsorption plate 22, since the adsorption plate 22 is movable, whether the adsorption plate 22 is in contact with the normally open contact or the normally closed contact, it can transfer heat to the contact heat-conducting plate 5, and the contact heat-conducting plate 5 conducts the heat away.

[0044] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. A single-cavity explosion-proof electromagnetic relay, comprising a base plate (1), a coil support (2) provided on one side of the base plate (1), a coil (21) installed in the coil support (2), and an adsorption plate (22) above the coil support (2) for contacting normally open or normally closed contacts, wherein normally open, normally closed and other contacts are integrated in the base plate (1), characterized in that: A contact heat-conducting plate (5) is embedded in the substrate (1) to contact normally open or normally closed contacts, and the upper and lower ends of the coil (21) are respectively in contact with the coil heat-conducting plate (4); An inner sleeve (3) connected to the substrate (1) is provided on the outside of the coil support (2), an outer sleeve (6) is provided on the outside of the inner sleeve (3), and a support grid (62) is provided on the inside of the outer sleeve (6). A gap for casting resin (8) is formed between the inner sleeve (3) and the outer sleeve (6); heat dissipation fins (7) are installed on the outside of the movable cover (61) by bolts.

2. The single-cavity explosion-proof electromagnetic relay as described in claim 1, characterized in that: The outer sleeve (6) adopts a split assembly structure, and a movable cover (61) is provided on one side of the heat-conducting plate in the outer sleeve (6).

3. A single-cavity explosion-proof electromagnetic relay as described in claim 2, characterized in that: An opening is provided inside the movable cover (61) for the outer ends of the coil heat-conducting plate (4) and the contact heat-conducting plate (5) to be exposed. After the movable cover (61) is installed, the outer ends of the coil heat-conducting plate (4) and the contact heat-conducting plate (5) are exposed 1-2 mm above the surface of the movable cover (61).

4. The single-cavity explosion-proof electromagnetic relay as described in claim 1, characterized in that: The inner sleeve (3) has a slot for the coil heat-conducting plate (4) to pass through.

5. A single-cavity explosion-proof electromagnetic relay as described in claim 3, characterized in that: The rear side of the heat dissipation fins (7) is in close contact with the outer end face of the coil heat-conducting plate (4) and the contact heat-conducting plate (5), and thermally conductive silicone is applied at their connection.

6. A single-cavity explosion-proof electromagnetic relay as described in claim 5, characterized in that: The coil heat-conducting plate (4) has a U-shaped structure with an inclination of 90 degrees, and the contact heat-conducting plate (5) has a T-shaped structure with an inclination of 90 degrees.

7. A single-cavity explosion-proof electromagnetic relay as described in claim 1, characterized in that: The coil (21) frame, coil heat-conducting plate (4), and contact heat-conducting plate (5) are all made of aluminum oxide plates that have undergone insulation treatment.

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