Electromagnetic relay for preventing contact sticking

Abstract

The application discloses an electromagnetic relay capable of preventing contact adhesion, and particularly relates to the technical field of relays, which comprises a shell, a contact mechanism, an electromagnet, an executing device and a protection assembly. The executing device comprises a limiting assembly arranged in the interior of the shell, which can control the closing or opening of the contact mechanism. The executing device further comprises a cleaning assembly, which can clean the surfaces of the moving contact and the static contact respectively. The protection assembly is arranged in the interior of the executing device, and can control the limiting assembly to open the contact mechanism when the circuit at the contact is overloaded. The moving contact is limited by the limiting plate, so that the repeated arc generated by the contact rebound is prevented from releasing huge heat in a short time to cause the contact adhesion. When the contact mechanism is opened, the surfaces of the moving contact and the static contact are in contact with the insulating plate, so that the oil stains or oxides and other substances are prevented from adhering to the surfaces of the contacts, thereby preventing the problems of contact adhesion or poor contact.

Description

Technical Field

[0001] This invention relates to the field of relay technology, and more specifically, to an electromagnetic relay that prevents contact sticking. Background Technology

[0002] An electromagnetic relay is an electromechanical component that uses an input signal (voltage, current) to generate electromagnetic force in the core of an electromagnet, attracting an armature, thereby causing the contacts to open, close, or switch control. However, if the relay is under overload, the contacts will continue to work under high current, and the contacts are prone to melting due to overheating, resulting in sticking.

[0003] Chinese Patent Application No. 202411630135.6 discloses a protective short-circuit relay, including a base, a side plate on one side of the top of the base, and a housing connected between the other side of the top of the base and the side plate. An electromagnetic coil is installed on the top of the base, and a bracket is installed on the top of the base between the electromagnetic coil and the housing. A horizontal plate is rotatably connected to the bracket, and an armature is connected to the horizontal plate. This patent describes a process where, when an electromagnetic coil is energized, it attracts an armature, causing the moving contact to approach the second stationary contact. The second connecting piece then presses a sliding rod down within the cylinder via a lever, allowing air to escape through a narrow first opening on the opening plate. Because the diameter of the first opening is limited, the exhaust effect is also limited, thus providing a buffering effect and preventing rapid impact between the moving and stationary contacts. This avoids the long-term cracking and damage to the contacts, extending the service life. However, due to the elasticity of the elastic element, the moving and stationary contacts bounce back upon contact. When the contacts close, the repeated arcing generated during this bounce can release enormous heat in a short time, causing the contact surface to heat up, soften, and melt rapidly, followed by rapid cooling and solidification, resulting in the contacts sticking together.

[0004] Furthermore, during long-term use, dust easily accumulates on the contact surfaces of the moving and stationary contacts. If dust, oil, or oxides deposit on the contact surface, it can cause the contacts to stick together, preventing the relay from disconnecting properly, increasing contact resistance, and causing poor contact. Therefore, this invention proposes an electromagnetic relay to prevent contact sticking and solve the above problems. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, embodiments of the present invention provide an electromagnetic relay that prevents contact adhesion, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an electromagnetic relay for preventing contact adhesion, comprising: a housing, a contact mechanism, an electromagnet, an actuator, and a protection component. The contact mechanism includes a moving contact and a stationary contact. The actuator includes a limiting component disposed inside the housing, which controls the closing or opening of the contact mechanism. The actuator further includes a cleaning component, which cleans the surfaces of the moving and stationary contacts when the contact mechanism switches from a closed state to an open state, and prevents dust from entering between the moving and stationary contacts when the contact mechanism is in an open state. The protection component is disposed inside the actuator, and controls the limiting component to open the contact mechanism when the circuit at the contact point is overloaded.

[0007] Preferably, the limiting component includes a pressure cover that is slidably connected to the housing, a limiting plate is provided on the top of the pressure cover, an insulating plate is fixedly connected to the bottom of the pressure cover, and a dust collection component is provided at one end of the insulating plate.

[0008] Preferably, the actuator further includes a pressure plate slidably connected to the housing, a first groove is provided at one end of the pressure plate near the pressure cover, a slider is slidably connected inside the first groove, a second groove is provided at one end of the pressure cover near the pressure plate, one end of the slider can slide into the second groove, and the upper end of the slider is an inclined surface.

[0009] Preferably, a heat-conducting rod is fixedly connected inside the second slide groove, one end of the heat-conducting rod is fixedly connected to a bimetallic strip, and the end of the heat-conducting rod away from the bimetallic strip extends through the second slide groove to the side of the limiting plate. A third elastic element is provided inside the first slide groove, one end of the third elastic element is fixedly connected to the first slide groove, and the other end of the third elastic element is fixedly connected to the slider.

[0010] Preferably, a guide cylinder is fixedly connected to the bottom of the housing, a guide rod is fixedly connected to one end of the pressure cap, the guide rod is slidably connected to the guide cylinder, a first elastic element is provided inside the guide cylinder, one end of the first elastic element is fixedly connected to the guide cylinder, and the other end of the first elastic element is fixedly connected to the guide rod.

[0011] Preferably, a second elastic element is provided inside the housing, one end of the second elastic element is fixedly connected to the bottom of the housing, the other end of the second elastic element is fixedly connected to the side wall of the pressure plate, a guide groove is fixedly connected to the bottom of the housing, and one end of the pressure plate slides inside the guide groove.

[0012] Preferably, one end of the stationary contact is fixedly connected to the bottom of the housing, the end of the stationary contact away from the housing is inside the gland, and the side wall of the end of the stationary contact away from the moving contact is in contact with the inner wall of the gland.

[0013] Preferably, the sidewall of the moving contact away from the stationary contact is in contact with the inner wall of the pressure cap, and the limiting plate is fixedly connected to the sidewall of the pressure cap in contact with the moving contact.

[0014] Preferably, a groove is provided at the bottom of the housing, one end of the moving contact is slidably connected to the groove, a spring is provided in the groove, one end of the spring is fixedly connected to the side wall of the groove, and the other end of the spring is fixedly connected to the moving contact.

[0015] Preferably, an armature is fixedly connected to the side of the pressure plate near the electromagnet.

[0016] The technical effects and advantages of this invention are as follows:

[0017] This invention prevents contact sticking caused by repeated arcing during contact mechanism closure, which releases enormous heat in a short time due to contact rebound. When the contact mechanism is open, the insulating plate contacts the surfaces of the moving and stationary contacts respectively, preventing fatigue or deformation of the spring inside the groove, which would prevent insufficient breaking force and contact sticking, thus avoiding the problem of the circuit failing to disconnect. It also prevents dust and oil from entering the contact surface, causing contact sticking or poor contact. Furthermore, when the relay is overloaded, the bimetallic strip undergoes thermal deformation, squeezing the slider and causing the pressure cap to move upwards to disconnect the contact mechanism, thus preventing contact sticking caused by contact melting due to continuous high current and localized overheating. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of the execution device of the present invention.

[0020] Figure 3 This is an exploded view of the overall structure of the present invention.

[0021] Figure 4 This is a cross-sectional view of the contact mechanism of the present invention in the closed state.

[0022] Figure 5 For the present invention Figure 4 An enlarged schematic diagram of the structure of part A.

[0023] Figure 6 This is a schematic diagram of the overload protection state of the present invention.

[0024] The reference numerals in the attached drawings are as follows: 1. Housing; 11. Contact mechanism; 111. Moving contact; 112. Stationary contact; 12. Electromagnet; 13. Guide cylinder; 2. Actuating device; 21. Limiting assembly; 211. Pressure cover; 212. Limiting plate; 22. Cleaning assembly; 221. Insulating plate; 222. Dust collection component; 23. Pressure plate; 24. Guide rod; 25. First elastic element; 26. Second elastic element; 3. Protection assembly; 31. First slide groove; 311. Third elastic element; 32. Slider; 33. Second slide groove; 331. Heat-conducting rod; 332. Bimetallic strip. Detailed Implementation

[0025] The technical solutions of 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] In actual production, when the contacts are closed, the repeated arcing generated when the contacts bounce back may release a huge amount of heat in a short time, causing the contact surface to heat up, soften, and melt rapidly in a localized manner, and then cool and solidify quickly, causing the contacts to stick together. This embodiment is invented to solve the above problems.

[0028] Please see Figures 1 to 6 As shown, an embodiment of the present invention provides an electromagnetic relay for preventing contact sticking, comprising a housing 1, a contact mechanism 11, an electromagnet 12, an actuator 2, and a protection component 3. The contact mechanism 11 includes a moving contact 111 and a stationary contact 112. The actuator 2 includes a limiting component 21 disposed inside the housing 1, which can control the closing or opening of the contact mechanism 11. The actuator 2 also includes a cleaning component 22, which can clean the surfaces of the moving contact 111 and the stationary contact 112 respectively when the contact mechanism 11 switches from a closed state to an open state. When the contact mechanism 11 is in an open state, the cleaning component 22 can prevent dust from entering between the moving contact 111 and the stationary contact 112. The protection component 3 is disposed inside the actuator 2. When the circuit at the contact is overloaded, the protection component 3 can control the limiting component 21 to open the contact mechanism 11.

[0029] Please see Figure 3 and Figure 4As shown, the limiting component 21 includes a pressure cover 211 that is slidably connected to the housing 1. A limiting plate 212 is provided on the top of the pressure cover 211, and an insulating plate 221 is fixedly connected to the bottom of the pressure cover 211. A dust collection component 222 is provided at one end of the insulating plate 221. A V-shaped groove is opened at one end of the insulating plate 221, and the bottom of the V-shaped groove is connected to the dust collection component 222. A mounting groove is opened at one end of the insulating plate 221, and the dust collection component 222 is disposed inside the mounting groove. The dust collection component 222 and the insulating plate 221 are detachably connected. This is prior art and will not be described in detail here.

[0030] Please see Figure 4 and Figure 5 As shown, the actuator 2 also includes a pressure plate 23 that is slidably connected to the housing 1. The pressure plate 23 has a first groove 31 at one end near the pressure cover 211. A slider 32 is slidably connected inside the first groove 31. The pressure cover 211 has a second groove 33 at one end near the pressure plate 23. One end of the slider 32 can slide into the second groove 33. The upper end of the slider 32 is an inclined surface.

[0031] Please see Figure 4 and Figure 5 As shown, a heat-conducting rod 331 is fixedly connected inside the second groove 33, combined with... Figure 3 and Figure 6 As shown, one end of the heat-conducting rod 331 is fixedly connected to a bimetallic strip 332, and the end of the heat-conducting rod 331 away from the bimetallic strip 332 extends through the second slide groove 33 to the side of the limiting plate 212. A third elastic element 311 is provided inside the first slide groove 31. One end of the third elastic element 311 is fixedly connected to the first slide groove 31, and the other end of the third elastic element 311 is fixedly connected to the slider 32. When the contact mechanism 11 is closed, the heat-conducting rod 331 contacts the side wall of the moving contact 111 away from the stationary contact 112. The heat-conducting rod 331 can transfer the heat of the moving contact 111 to the bimetallic strip 332. The bimetallic strip 332 can expand and deform when heated. This is the prior art and will not be described in detail.

[0032] Please see Figure 3 and Figure 4 As shown, a guide cylinder 13 is fixedly connected to the bottom of the housing 1, and a guide rod 24 is fixedly connected to one end of the pressure cap 211. The guide rod 24 is slidably connected to the guide cylinder 13. A first elastic element 25 is provided inside the guide cylinder 13. One end of the first elastic element 25 is fixedly connected to the guide cylinder 13, and the other end of the first elastic element 25 is fixedly connected to the guide rod 24.

[0033] Please see Figure 4 and Figure 6As shown, a second elastic element 26 is provided inside the housing 1. One end of the second elastic element 26 is fixedly connected to the bottom of the housing 1, and the other end of the second elastic element 26 is fixedly connected to the side wall of the pressure plate 23. A guide groove is fixedly connected to the bottom of the housing 1, and one end of the pressure plate 23 slides inside the guide groove.

[0034] Please see Figure 4 As shown, one end of the stationary contact 112 is fixedly connected to the bottom of the housing 1. The end of the stationary contact 112 away from the housing 1 is inside the pressure cover 211. The side wall of the end of the stationary contact 112 away from the moving contact 111 is in contact with the inner wall of the pressure cover 211. The side wall of the end of the moving contact 111 away from the stationary contact 112 is in contact with the inner wall of the pressure cover 211. The limiting plate 212 is fixedly connected to the side wall of the pressure cover 211 that is in contact with the moving contact 111. The end of the limiting plate 212 near the moving contact 111 and the end of the moving contact 111 near the limiting plate 212 are both arc-shaped. The limiting plate 212 can squeeze the moving contact 111 to move closer to the stationary contact 112.

[0035] Please see Figure 3 As shown, a groove is provided at the bottom of the housing 1, one end of the moving contact 111 is slidably connected to the groove, a spring is provided in the groove, one end of the spring is fixedly connected to the side wall of the groove, and the other end of the spring is fixedly connected to the moving contact 111.

[0036] Please see Figure 1 As shown, an armature is fixedly connected to the side of the pressure plate 23 near the electromagnet 12. When the electromagnet 12 is energized, the electromagnet 12 can attract the armature, causing it to move the pressure plate 23 downward.

[0037] In use, initially, the contact mechanism 11 is in the open state. The two sides of the insulating plate 221 contact the moving contact 111 and the stationary contact 112, respectively. The slider 32 extends into the second groove 33. When the electromagnet 12 is energized, it attracts the armature, causing the pressure plate 23 to move downwards. The pressure plate 23 drives the pressure cover 211 to slide downwards, compressing the first elastic element 25 and the second elastic element 26. When the pressure cover 211 slides downwards until the limiting plate 212 presses against the moving contact 111, the pressure cover 211 continues to slide downwards, causing the limiting plate 212 to press against the moving contact 111 and simultaneously limit the moving contact 111. This causes the moving contact 111 to slide closer to the stationary contact 112 and contact it. The spring inside the groove is compressed, and the contact mechanism 11 is in the closed state. When it is necessary to disconnect the contact mechanism 11, the electromagnet 12 is de-energized, the armature is no longer attracted, and the first elastic element... 25 and the second elastic element 26 relax, causing the pressure plate 23 and the pressure cover 211 to move upward. When the pressure cover 211 moves to the point where the limiting plate 212 no longer limits the moving contact 111, the spring inside the groove recovers, causing the moving contact 111 and the stationary contact 112 to separate, and the contact mechanism 11 is disconnected. At this time, the pressure cover 211 continues to move upward, causing the two sides of the insulating plate 221 to contact the moving contact 111 and the stationary contact 112 respectively. By limiting the moving contact 111 when the contact mechanism 11 is closed, the limiting plate 212 squeezes the moving contact 111 and limits the moving contact 111, thereby preventing the contact sticking caused by the repeated arcing generated by the contact rebound and the release of huge heat in a short time. When the contact mechanism 11 is disconnected, the two sides of the insulating plate 221 contact the surfaces of the moving contact 111 and the stationary contact 112 respectively, thereby preventing the spring inside the groove from fatigued or deformed, unable to provide sufficient breaking force, and the contacts from being unable to separate in time, resulting in the problem of the contact sticking and the circuit not being able to be disconnected.

[0038] Example 2

[0039] In actual use, it was found that dust easily accumulates on the contact surfaces of the moving contact 111 and the stationary contact 112 during long-term use. If dust, oil, oxides or other substances are deposited on the contact surface, it will cause the contacts to stick together, making the relay unable to disconnect normally, increasing the contact resistance, and causing poor contact. Further improvements have been made based on the above embodiments.

[0040] Based on the above embodiments, during use, when the contact mechanism 11 switches from a closed state to an open state, the pressure cover 211 moves to the limit plate 212, which no longer limits the moving contact 111. The spring inside the groove returns to its original position, causing the moving contact 111 and the stationary contact 112 to separate, and the contact mechanism 11 disconnects. At this time, the pressure cover 211 drives the insulating plate 221 to move upward, so that the top of the insulating plate 221 slides between the contact surfaces of the moving contact 111 and the stationary contact 112, thereby scraping away the dust and oil stains between the moving contact 111 and the stationary contact 112, which then fall into the dust collection box through the V-groove. Inside component 222, when the pressure cover 211 moves upward to its limit position, the two sides of the insulating plate 221 contact the moving contact 111 and the stationary contact 112 respectively, thereby preventing dust and oil from entering the contact surfaces of the moving contact 111 and the stationary contact 112. The insulating plate 221 contacts the surfaces of the moving contact 111 and the stationary contact 112, and scrapes away dust from the surfaces of the moving contact 111 and the stationary contact 112 when the contact mechanism 11 is disconnected, preventing oil or oxides from adhering to the contact surface and causing contact adhesion or poor contact.

[0041] Example 3

[0042] In practical use, it was found that if the relay is under overload, the contacts will continue to work under high current, and the contacts are prone to melting due to overheating, resulting in adhesion. Further improvements were made based on the above embodiments.

[0043] Based on the above embodiments, during use, when closed, the heat-conducting rod 331 contacts the side of the moving contact 111 away from the stationary contact 112. When the relay is in a long-term overload state, the contact mechanism 11 continuously bears a large current, causing the temperature of the moving contact 111 and the stationary contact 112 to rise, thereby increasing the heat of the heat-conducting rod 331. This temperature increase of the heat-conducting rod 331 causes the bimetallic strip 332 to deform, thus pressing the slider 32. This causes the slider 32 to slide inside the first groove 31 and the second groove 33, while simultaneously compressing the third elastic element 311. As the temperature gradually increases, the deformation of the bimetallic strip 332 gradually increases. When the bimetallic strip 332 presses the slider 32 to disengage it from the second slide groove 33, the first elastic element 25 relaxes, causing the pressure cap 211 to move upward, thereby disconnecting the contact mechanism 11 and providing overload protection for the relay. Simultaneously, the third elastic element 311 is no longer compressed, and the slider 32 extends out of the first slide groove 31 again. When the electromagnet 12 is de-energized, the pressure plate 23 moves upward. When the upper inclined surface of the slider 32 contacts the pressure cap 211, the pressure plate 23 continues to move upward, causing the slider 32 to be pressed into the first slide groove 31, while simultaneously compressing the third elastic element 311. When the pressure plate 23 reaches its limit position, the third elastic element 311 relaxes, pushing the slider 32 back into the second slide groove 33, and the relay returns to its initial state. The bimetallic strip 332 undergoes thermal deformation, pressing the slider 32 and causing the pressure cap 211 to move upward, disconnecting the contact mechanism 11. This prevents contact melting and adhesion caused by localized overheating due to continuous high current at the contacts.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An electromagnetic relay for preventing contact sticking, comprising a housing, a contact mechanism and an electromagnet, the contact mechanism comprising a movable contact and a stationary contact, characterized in that, Also include: The execution device includes a limiting component arranged in the interior of the shell, which can control the closing or opening of the contact mechanism; The execution device also includes a cleaning component that can clean the surface of the moving contact and the stationary contact respectively when the contact mechanism is switched from the closed state to the open state, and can prevent dust from entering between the moving contact and the stationary contact when the contact mechanism is in the open state; The protection component is arranged in the interior of the execution device, which can control the limiting component to disconnect the contact mechanism when the contact circuit is overloaded; The limiting component includes a gland slidingly connected with the shell, the top of the gland is provided with a limiting plate, the bottom of the gland is fixedly connected with an insulating plate, one end of the insulating plate is provided with a dust collecting piece; The execution device also includes a pressing plate slidingly connected with the shell, one end of the pressing plate close to the gland is provided with a first sliding groove, the first sliding groove is slidingly connected with a sliding block, one end of the sliding block can be extended into the second sliding groove by sliding, and the upper end of the sliding block is a slope; One end of the stationary contact is fixedly connected with the bottom of the shell, the end of the stationary contact away from the shell is in the interior of the gland, the side wall of the end of the stationary contact away from the moving contact is in contact with the inner wall of the gland, the side wall of the end of the moving contact away from the stationary contact is in contact with the inner wall of the gland, the limiting plate is fixedly connected with the side wall of the gland in contact with the moving contact, one end of the limiting plate close to the moving contact and one end of the moving contact close to the limiting plate are arc-shaped, and the limiting plate can extrude the moving contact to make it close to the stationary contact; When closing the contact mechanism, the limiting plate extrudes the moving contact while limiting the moving contact, and when the contact mechanism is disconnected, the two side surfaces of the insulating plate are respectively in contact with the surfaces of the moving contact and the stationary contact.

2. The electromagnetic relay for preventing contact sticking according to claim 1, characterized by: The second sliding groove is fixedly connected with a heat conducting rod, one end of the heat conducting rod is fixedly connected with a bimetallic strip, the end of the heat conducting rod away from the bimetallic strip extends to the side of the limiting plate through the second sliding groove, the first sliding groove is provided with a third elastic piece, one end of the third elastic piece is fixedly connected with the first sliding groove, and the other end of the third elastic piece is fixedly connected with the sliding block.

3. The electromagnetic relay to prevent contact sticking according to claim 2, characterized in that: The bottom of the shell is fixedly connected with a guide cylinder, one end of the gland is fixedly connected with a guide rod, the guide rod is slidingly connected with the guide cylinder, the guide cylinder is provided with a first elastic piece, one end of the first elastic piece is fixedly connected with the guide cylinder, and the other end of the first elastic piece is fixedly connected with the guide rod.

4. The electromagnetic relay for preventing contact sticking according to claim 3, characterized by: The interior of the shell is provided with a second elastic piece, one end of the second elastic piece is fixedly connected with the bottom of the shell, the other end of the second elastic piece is fixedly connected with the side wall of the pressing plate, the bottom of the shell is fixedly connected with a guide groove, and one end of the pressing plate slides in the guide groove.

5. The electromagnetic relay to prevent contact sticking according to claim 4, characterized in that: The bottom of the shell is provided with a groove, one end of the moving contact is slidingly connected with the groove, the groove is provided with a spring, one end of the spring is fixedly connected with the side wall of the groove, and the other end of the spring is fixedly connected with the moving contact.

6. The electromagnetic relay to prevent contact sticking according to claim 5, characterized in that: The side of the pressing plate close to the electromagnet is fixedly connected with a armature.

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