Surge protector and thermal trip device for a surge protector

Abstract

The utility model relates to a thermal trip device and surge protector for surge protector, the surge protector includes the nonlinear element with the lead-out sheet, the thermal trip device includes the piece that detaches, trip lever and energy storage spare. The piece that detaches includes the first section with the lead-out sheet through the soldering tin connection, the trip lever includes the pilot feature part and the cutting feature part, they are adjacent to each other in order to when the soldering tin melts allow trip lever under the action of energy storage spare moves in the specific mode, make the pilot feature part contact with the piece that detaches and push the piece that detaches to the first position ahead of the cutting feature part, and make the cutting feature part contact with the piece that detaches in the process that trip lever continues to move, push the piece that detaches to the second position and finally stay between the piece that detaches and the lead-out sheet, thereby realize the isolation between the piece that detaches and the lead-out sheet. The pilot trip technology of the utility model separates the upper top detaching function and the cutting isolation function of trip lever, reduces or avoids the risk of the trip failure.

Description

Technical Field

[0001] This utility model relates to the technical field of electrical protectors, and specifically to a thermal tripping device for a surge protector and a surge protector including such a thermal tripping device. Background Technology

[0002] Surge protectors (also known as surge protectors or lightning arresters, SPDs) are primarily used in the field of low-voltage electrical equipment to provide safety protection for various electronic devices, instruments, and communication lines. Specifically, when a power supply line or communication line experiences a sudden spike in current or voltage due to external interference (e.g., lightning), the surge protector can limit the instantaneous overvoltage entering the power supply line or communication line to within the voltage range that the electrical equipment can withstand within a very short time, thereby protecting the electrical equipment from overvoltage damage.

[0003] Existing surge protectors mainly include nonlinear elements, thermal trip devices, and remote signaling triggering devices. The nonlinear element, for example, is a varistor, which presents high impedance under normal conditions but rapidly conducts to form a current path when a voltage spike occurs in the line. This nonlinear element may have two leads, each electrically connected to a different electrode pin. The thermal trip device may include a release element, a trip lever, and an energy storage element. The release element can be connected to one lead of the nonlinear element via low-temperature solder to electrically connect that lead to one electrode pin. When the nonlinear element overheats abnormally, for example due to a fault, the low-temperature solder on its lead can melt. At this time, the trip lever can move under the drive of the energy storage element, pushing the release element to disconnect it from the lead, thereby breaking the electrical connection path in the surge protector. This process can be called "tripping".

[0004] In currently known surge protectors, thermal trip devices are generally designed to trip via rotational motion, sliding motion, or a combination of both. The moving parts of such trip devices, especially the trip lever, typically have a fixed motion pattern and trajectory, moving along a predetermined path during tripping. This known design makes the trip lever prone to malfunction during movement, such as getting stuck by unmelted solder, leading to tripping failure. Furthermore, if the part of the trip lever used to push the release element is damaged, such as softening or deforming due to heat, it can also prevent properly pushing the release element away from the lead, resulting in tripping failure. Utility Model Content

[0005] The purpose of this utility model is to solve at least one of the above-mentioned problems and / or other problems existing in the prior art.

[0006] Therefore, this utility model provides a thermal tripping device for a surge protector. The thermal tripping device includes a release element, a tripping lever, and an energy storage element. The release element includes a first section, which is fixed to the lead-out tab of a nonlinear element by solder. The tripping lever includes a pilot feature and a cut-off feature, which are adjacent to each other. When the solder melts, the tripping lever is allowed to move under the action of the energy storage element in the following manner: In the initial stage of movement, the pilot feature contacts the release element before the cut-off feature and pushes the release element to a first position; under further action of the energy storage element, the tripping lever continues to move, causing the cut-off feature to contact the release element and further push the release element to a second position; under continued action of the energy storage element, the cut-off feature moves further and finally stops between the release element and the lead-out tab, thereby achieving isolation between the release element and the lead-out tab.

[0007] This invention proposes a solution that can be called pilot release technology. This solution separates the upward release function of the release rod from the arc cutting isolation function by setting a pilot feature and a cutting feature that are distinct from each other on the release rod. This improves the reliability of the release rod's release movement and avoids release failure caused by factors such as welding quality and excessive temperature.

[0008] According to a preferred embodiment of the present invention, the pilot feature is constructed and arranged to contact or be spaced apart from the release element when the solder is not melted (i.e., not in contact with the release element). This embodiment defines different initial arrangement states of the pilot feature, reflecting the design flexibility of the present invention.

[0009] According to a preferred embodiment of the present invention, the cutting feature has a stepped profile and includes at least two inclined surfaces that form different angles relative to the direction of movement of the tripping lever, so as to gradually change the direction of the contact friction between the cutting feature and the release member and reduce the force of the contact friction. This embodiment allows the release member to move along a varying trajectory and allows the tripping lever to effectively adapt to the fact that the pushing force of the energy storage element (e.g., a compression spring) may gradually decrease during the movement of the tripping lever, ensuring that the release member of the thermal tripping device and the lead-out tab of the nonlinear element can ultimately maintain a predetermined interval.

[0010] According to a preferred embodiment of the present invention, the disengagement member further includes a second segment, which extends from the first segment at an angle (i.e., forming a non-zero angle) relative to the first segment, and a pilot auxiliary feature is formed in the second segment, the pilot auxiliary feature protruding toward the pilot feature on the release lever. By providing mutually cooperating pilot features and pilot auxiliary features, this embodiment can advantageously ensure the implementation of the pilot disengagement technology.

[0011] According to a preferred embodiment of the present invention, the pilot feature is configured to be offset relative to the cutting feature in a direction perpendicular to the direction of movement of the trip lever. Here, "offset" means that the working surface of the pilot feature (i.e., the surface facing the release member, or the surface used to contact the release member to act on it) is not in the same plane as the working surface of the cutting feature. The specific form of the pilot feature defined in this embodiment can be easily formed at a low cost.

[0012] According to a preferred embodiment of the present invention, a through hole is provided in the first section for the flow of solder in a fluid state. In this embodiment, the fluid solder flowing through the through hole on the release member can solidify and be fixed on the surface of the release member with a larger size (especially the diameter), thereby forming a structure similar to a rivet head, thereby enhancing the connection strength between the release member and the lead-out piece.

[0013] According to a preferred embodiment of the present invention, the pilot feature is disposed on one or both sides of the cutting feature. That is, one pilot feature or two pilot features can be disposed side by side with the cutting feature. The pilot feature is less or almost unaffected by adverse factors between the release element and the lead-out piece (e.g., solidified solder blocks, high temperatures), ensuring the normal realization of the pilot function.

[0014] According to a preferred embodiment of the present invention, the pilot feature is at least partially disposed outside the extension range of the mating surface between the release member and the lead-out tab. According to this embodiment, during the movement of the trip lever, the pilot feature will not pass through the area where the welded joint between the release member and the lead-out tab is located, thus avoiding the influence of adverse factors in such area.

[0015] According to a preferred embodiment of the present invention, the trip lever further includes a flexible indicator portion disposed at its end, the flexible indicator portion having a feature structure for indicating whether a fuse has tripped. By providing a flexible indicator portion on the trip lever and correspondingly opening an observation window in the surge protector's housing, the user can intuitively understand the status changes of the surge protector, thereby allowing for timely replacement of the surge protector when necessary to prevent power line accidents.

[0016] On the other hand, this invention provides a surge protector that includes a nonlinear element and a thermal trip device as described above. Thus, the surge protector can possess the advantages or technical effects related to the thermal trip device described above. Attached Figure Description

[0017] The features and advantages of this utility model will become clear from the following detailed description provided with reference to the accompanying drawings. It should be understood that the following drawings are merely schematic and not necessarily drawn to scale, and therefore should not be considered as limitations on this utility model, wherein:

[0018] Figure 1 A perspective view of a surge protector according to a specific embodiment of the present invention is shown;

[0019] Figure 2 Show Figure 1 Exploded perspective view of an embodiment of the thermal tripping device of a surge protector;

[0020] Figure 3 Show Figure 1 A side view of a surge protector, with the surge protector housing removed and the thermal trip device in its initial assembly state;

[0021] Figure 4 Showing with Figure 3 A similar view, in which the disengagement component of the thermal trip device is in the first position;

[0022] Figure 5 Showing with Figure 3 A similar view, in which the disengaged part of the thermal trip device is in the second position;

[0023] Figure 6 Showing with Figure 3 A similar view, in which the disengagement element of the thermal trip device is in the tripped position. Detailed Implementation

[0024] Specific embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the present invention. However, it will be apparent to those skilled in the art that implementations of the present invention may not include some of these specific details. Furthermore, it should be understood that the present invention is not limited to the specific embodiments described. Rather, the present invention can be conceived to be implemented with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as elements or limitations of the claims unless expressly set forth in the claims.

[0025] This utility model relates to a surge protector, which can be connected in parallel with the protected electrical equipment (especially low-voltage electrical equipment) in a power supply line or communication line. The surge protector is typically configured to present high impedance under normal conditions, but instantaneously conduct when an overvoltage occurs in the power supply line, limiting the voltage across the electrical equipment to a range that the equipment can withstand, while simultaneously discharging the overcurrent to ground.

[0026] When a surge protector malfunctions due to abnormal aging or deterioration for various reasons, the internal components of the surge protector, especially the nonlinear components, will heat up violently, causing the low-temperature solder on its lead-out piece to melt. This allows the associated thermal tripping device to activate, disconnecting the lead-out piece from the electrode pin, thereby breaking the electrical connection path within the surge protector and preventing accidents such as fires caused by short circuits.

[0027] according to Figure 1 In the embodiment shown, the surge protector may include a box-shaped housing 6, which may consist of a base 61 and a cover 62 that encloses the base 61. Figure 1 The structure (shown in the open state) is configured to accommodate a nonlinear element 5 (e.g., a varistor) and a thermal trip device associated with the nonlinear element 5. An anti-misinsertion lever 7 can extend from the bottom of the housing 6 and may have a special cross-sectional shape corresponding to a specific surge protector model to prevent the surge protector from being inserted into the wrong base and connected to an incorrect backup protector model.

[0028] The surge protector may include two electrode pins 52, which can be electrically connected to a nonlinear element 5 (specifically, a lead of the nonlinear element 5) and extend from the housing 6 for insertion into an electrical terminal or socket electrically connected to a power supply line. For example, one lead of the nonlinear element 5 may be connected to one electrode pin 52 ( Figure 1 The electrode pin on the left side of the nonlinear element 5 is directly connected, and the other lead of the nonlinear element 5 can be connected to another electrode pin 52 via a thermal trip device (especially the release element 1, which will be described in detail below). Figure 1 The other lead is connected to the detachment member 1 of the thermal trip device. In particular, the other lead can be soldered to the detachment member 1 of the thermal trip device using a low-temperature soldering material, such as low-temperature solder. This allows the other lead to separate from the detachment member 1 when the nonlinear element 5 heats up abnormally and melts the low-temperature soldering material, thereby disconnecting the electrical connection between the nonlinear element 5 and one of the electrode pins 52, which means disconnecting the electrical connection path between the surge protector and the power supply line.

[0029] Of course, it is also possible to not set up independent electrode pins, but to extend and bend one of the leads of the nonlinear element 5 to form an electrode pin, and / or bend the end of the detachment 1 to form another electrode pin.

[0030] See now Figure 2 It shows that it can be used in Figure 1 An exploded perspective view of an exemplary thermal trip device in a surge protector. (See attached image.) Figure 2 As shown, the thermal tripping device of this utility model may include a release component 1, a tripping rod 2, and an energy storage component 3. The release component 1 may include a first section 11, which can connect with a lead-out piece 51 of the nonlinear element 5 (see...). Figure 3 The trip lever 2 is connected together by soldering. The trip lever 2 may include a characteristic actuating portion, particularly a cut-off characteristic portion 21 and a pilot characteristic portion 22 adjacent to each other. The characteristic actuating portion, for example, has a specific shape and can be configured such that when the solder between the release member 1 and the lead-out piece 51 melts, the trip lever 2 can move under the action of the energy storage member 3 in the following manner: the movement of the trip lever 2 causes the pilot characteristic portion 22 to contact the release member 1 before the cut-off characteristic portion 21 and push the release member 1 to a first position (see...). Figure 4 Under the further action of the energy storage component 3, the trip lever 2 continues to move, causing the cutting feature 21 to contact the release component 1 and further push the release component 1 to the second position (see...). Figure 5 Under the continued action of the energy storage component 3, the cutting feature 21 moves further and eventually stops between the detachment component 1 and the lead-out piece 51, thereby achieving isolation between the detachment component 1 and the lead-out piece 51 (see...). Figure 6 ).

[0031] like Figure 2 As shown, the release element 1 can be made of a metal strip and can include two or more segments. Specifically, the release element 1 can include a first segment 11 for welding to the lead-out tab 51 of the nonlinear element 5, a second segment 12 extending at an angle relative to the first segment 11 from the first segment 11, and an optional third segment 13. The third segment 13 can be connected to the second segment 12 at one end via an arc-shaped transition section so as to extend substantially parallel to the first segment 11, and can be bent at the other end to connect to or form an electrode pin 52.

[0032] The trip lever 2 can be disposed on the other side of the lead-out piece 51 of the nonlinear element 5, opposite to the release member 1 (see [reference]). Figure 3 And is constructed and arranged to be movable relative to the release member 1 and the lead-out piece 51 under the action of an energy storage element 3, such as a compression spring, as... Figure 2As indicated by arrow F in the diagram. The trip lever 2 may include a lever portion 24, the aforementioned characteristic action portion, and a flexible indicator portion 23 disposed at its end.

[0033] The rod portion 24 may have, for example, a cylindrical shape, and may be as follows: Figure 1 As shown, the lever 24 is configured to extend from the surge protector housing 6 in its initial assembled state so as to interact with a remote signaling mechanism (not shown). This allows the remote signaling mechanism to sense changes in the surge protector's state via movement of the lever 24, thereby generating and transmitting remote signaling signals. The energy storage element 3 can be fitted onto the lever 24 and can be compressed against the inner wall surface of the housing 6 at one end and against the characteristic actuating portion at the other end, thereby generating a driving force for actuating the trip lever 2.

[0034] The flexible indicator 23 can be disposed at the end of the trip lever 2 opposite to its lever portion 24, and can slide along the guide groove 611 in the housing 6 (especially disposed on the base 61) when the trip lever 2 moves (see Figure 1 ) slide, thereby causing the characteristic structures on the flexible indicator 23, such as a specific texture or pattern or color coating, to slide against the window 612 in the base 61 of the housing 6 (see Figure 1 The flexible indicator 23 is aligned to show the user the status changes of the surge protector, especially whether a fuse has blown. Advantageously, the flexible indicator 23 can be sheet-shaped.

[0035] It should be noted here that the trip lever 2 can be a monolithic component made of, for example, plastic material. That is, the lever portion 24, the characteristic function portion, and the indicator portion 23 described above can be integrally formed, for example, by injection molding. Of course, these parts of the trip lever 2, such as the flexible indicator portion 23, can also be formed separately and then assembled together.

[0036] See also Figure 2 and combined Figures 3 to 6 The characteristic function portion of the trip lever 2 can protrude relative to the rest of the trip lever 2 (especially the lever portion 24), and can be disposed between the lever portion 24 and the flexible indicator portion 23. In the initial assembled state, this characteristic function portion can be located upstream of the lead-out piece 51 of the nonlinear element 5 relative to the moving direction F of the trip lever 2, and immediately adjacent to the joint between the lead-out piece 51 and the release member 1, such as... Figure 3 As shown in the image.

[0037] Advantageously, the leading feature 22 of the feature function can be constructed and arranged to contact the detachment 1 when the solder between the lead-out piece 51 and the detachment piece 1 has not melted (i.e., in the initial assembly state), or not to contact the detachment piece 1.

[0038] Back Figure 2According to the preferred embodiment shown in the figure, the characteristic working part of the trip lever 2 can be in the form of an integral wedge block, wherein the pilot feature 22 and the cutting feature 21 can be arranged side by side, and the pilot feature 22 can be configured to be offset relative to the cutting feature 21 in a direction perpendicular to the moving direction F of the trip lever 2. In other words, the working surface of the pilot feature 22 (i.e., the surface facing the release member 1 and acting on the surface of the release member 1) and the working surface of the cutting feature 21 (i.e., the surface facing the release member 1 and acting on the surface of the release member 1) are respectively in different planes. Here, preferably, the working surface of the pilot feature 22 and the working surface of the cutting feature 21 can form different angles relative to the moving direction F of the trip lever 2.

[0039] In this way, when the solder melts and the trip lever 2 moves under the action of the energy storage member 3, the pilot feature 22 can advantageously perform its function as the pilot push-open release member 1, and will not interfere with the cut-off feature 21.

[0040] Preferably, the pilot feature 22 is disposed on the side of the cut-off feature 21 away from the lead-out piece 51. More preferably, the pilot feature 22 is at least partially (preferably entirely) disposed outside the extension range of the mating surface between the release member 1 and the lead-out piece 51.

[0041] Therefore, compared to the cut-off feature 21 which directly faces the mating surface between the release element 1 and the lead-out piece 51, the pilot feature 22 is less affected by adverse factors that are prone to occur in the mating surface area (such as unmelted solder blocks, high temperatures generated by the nonlinear element 5, etc.), or may not be affected by these adverse factors at all. This further ensures the realization of the pilot function.

[0042] See Figures 2 to 6 Preferably, the release member 1 may include a pilot auxiliary feature 121 for cooperating with the pilot feature 22. This pilot auxiliary feature 121 may be formed in a second segment 12 of the release member 1 adjacent to its first segment 11, and may—in the initial assembled state—protrude toward the pilot feature 22 relative to the remainder of the second segment 12. For example, the pilot auxiliary feature 121 may be formed by stamping a portion of the second segment 12.

[0043] In this configuration, the pilot feature 22 can be retracted relative to the cutting feature 21, which facilitates its cooperation with the pilot auxiliary feature 121. For example, in the initial assembly state, the pilot feature 22 and the pilot auxiliary feature 121 can at least partially face-to-face, in order to prevent impurities or obstacles such as solder lumps from appearing on the movement path of the pilot feature 22, and to enable the pilot feature 22 to push open the detachment member 1 as early as possible.

[0044] See still Figure 2 According to the preferred embodiment shown in the figure, the cutting feature 21 of the trip lever 2 may have a stepped profile and may include at least two inclined surfaces, such as two successive inclined surfaces 211, 212, which may be configured to form different angles relative to the moving direction F of the trip lever 2. Thus, when the solder melts and the trip lever 2 moves along direction F, these inclined surfaces at different angles can gradually change the direction of the contact friction between the cutting feature 21 and the release member 1, and gradually reduce the force value of the contact friction.

[0045] This design takes into account the fact that the driving force of the energy storage element 3 (especially the compression spring) used to drive the trip lever 2 gradually decreases during the movement of the trip lever 2, making the movement of the trip lever 2 smoother and advantageously ensuring that the predetermined distance between the first segment 11 of the release element 1 and the lead-out piece 51 of the nonlinear element 5 is maintained in the final position, such as Figure 6 As shown.

[0046] like Figure 1-6 As shown, advantageously, a through hole 110 can be provided in the first section 11 of the release member 1 for the flow of solder in a fluid state. Also advantageously, a through-hole for the flow of solder in a fluid state can be provided on the lead-out tab 51 of the nonlinear element 5. Figure 5 (See in the middle).

[0047] In this way, when the release member 1 and the nonlinear element 5 are soldered together, the fluid solder (e.g., solder) can flow through the through hole 110 or the through-hole to the surface of the first section 11 or the lead-out piece 51 facing away from them, and can solidify on the surface in a larger size, thereby forming a structure similar to a rivet head, which enhances the connection between the first section 11 of the release member 1 and the lead-out piece 51 of the nonlinear element 5.

[0048] Various modifications and variations can be made to the embodiments disclosed above without departing from the scope or spirit of this invention. Other embodiments of this invention will be apparent to those skilled in the art based on the practice of this invention disclosed in this specification. This specification and the examples disclosed herein should be considered illustrative only, and the true scope of this invention is defined by the appended claims and their equivalents.

Claims

1. A thermal tripping device for a surge protector, characterized in that, The thermal trip device includes a release component (1), a trip lever (2), and an energy storage component (3). The detachment component (1) includes a first segment (11), which is fixed to the lead-out piece (51) of the nonlinear element (5) by solder. The trip lever (2) includes a pilot feature (22) and a cutting feature (21), which are adjacent to each other so that when the solder melts, the trip lever (2) can move under the action of the energy storage member (3). During the movement, the pilot feature (22) contacts the release member (1) before the cutting feature (21) and pushes the release member (1) to the first position. Furthermore, the trip lever (2) is allowed to continue moving under the further action of the energy storage member (3), so that the cutting feature (21) contacts the release member (1), and further pushes the release member (1) to the second position. And allow the cut-off feature (21) to move further under the action of the energy storage member (3) and finally stop between the detachment member (1) and the lead-out piece (51), thereby achieving isolation between the detachment member (1) and the lead-out piece (51).

2. The thermal tripping device according to claim 1, characterized in that, The pilot feature (22) is constructed and arranged to contact or be spaced apart from the release member (1) when the solder is not melted.

3. The thermal tripping device according to claim 1 or 2, characterized in that, The cutting feature (21) has a stepped profile and includes at least two inclined surfaces (211, 212), which form different angles relative to the moving direction (F) of the release lever (2) in order to gradually change the direction of the contact friction between the cutting feature (21) and the release member (1) and reduce the force value of the contact friction.

4. The thermal tripping device according to claim 1 or 2, characterized in that, The detachment member (1) further includes a second segment (12) that extends at an angle relative to the first segment (11) from the first segment (11), and a pilot auxiliary feature (121) is formed in the second segment (12) that protrudes toward the pilot feature (22).

5. The thermal tripping device according to claim 1 or 2, characterized in that, The pilot feature (22) is configured to be offset relative to the cut-off feature (21) in a direction perpendicular to the moving direction (F) of the trip lever (2).

6. The thermal tripping device according to claim 1 or 2, characterized in that, The first section (11) is provided with a through hole (110) for allowing solder in a fluid state to flow through.

7. The thermal tripping device according to claim 1 or 2, characterized in that, The pilot feature (22) is disposed on one or both sides of the cutting feature (21).

8. The thermal tripping device according to claim 1 or 2, characterized in that, The pilot feature (22) is at least partially located outside the extension range of the mating surface between the release member (1) and the lead-out piece (51).

9. The thermal tripping device according to claim 1 or 2, characterized in that, The trip lever (2) also includes a flexible indicator (23) at its end, which has a feature structure for indicating whether a meltdown has occurred.

10. A surge protector comprising a nonlinear element (5), characterized in that, The surge protector includes a thermal trip device according to any one of claims 1-9.

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