A thermal trip mechanism

Abstract

The present application belongs to surge protection equipment, disclose a kind of thermal tripping mechanism, for the entity current leakage protection device being arranged on circuit board is applied with sustained thrust, including the anti-falling cover and base being arranged on both sides of circuit board;Circuit board has opening at the position where current leakage protection device is arranged, for the force storage mechanism being arranged in base to pass through opening and contact with current leakage protection device being fixed on circuit board by low melting point material welding mode and sustained thrust is applied, and the thrust gives current leakage protection device the movement tendency of action towards the inside of anti-falling cover.The thermal tripping mechanism provided by the present application is used to cooperate with the current leakage protection device being arranged on circuit board, and a pushing force is continuously given to current leakage protection device by force storage mechanism, so that it can timely separate contact when the fixed connection part of circuit board is melted in the process of deterioration short-circuit heating, so as to realize better passive tripping protection effect.

Description

Technical Field

[0001] This invention belongs to the field of lightning protection equipment technology, and specifically relates to a thermal tripping mechanism. Background Technology

[0002] Lightning disasters are among the most severe natural disasters, causing countless casualties and property losses worldwide each year. With the widespread use of integrated electronic and microelectronic devices, damage to systems and equipment caused by lightning overvoltages and electromagnetic pulses is increasing. Therefore, it is crucial to address the issue of lightning protection for electronic information systems as soon as possible. Sustained-state power distribution (SPD) devices are indispensable for lightning protection of electronic equipment. Their function is to limit transient overvoltages entering power lines and signal transmission lines to within the voltage range that the equipment or system can withstand, or to divert powerful lightning currents to the ground, protecting the protected equipment or system from impact.

[0003] While surge protectors (SPDs) come in various structures and configurations, the core components in most SPDs are prone to degradation and failure. When damage or degradation occurs, the SPD structure, which should be breaking the circuit, becomes a short circuit, allowing current to continuously leak out. This causes the core components to overheat, creating a fire hazard. To effectively prevent this, existing SPD devices are equipped with thermal trip mechanisms. These mechanisms disconnect the circuit when leakage current reaches a certain temperature, preventing fires. Thermal tripping essentially means overheat protection tripping. Overheat protection is an overload protection system with delayed tripping and delayed return characteristics, operating based on the thermal effect of the current flowing through the trip unit. This mechanism typically breaks the circuit directly without affecting other internal components. However, many circuit boards integrate SPD modules, and because their circuitry is printed, ordinary thermal trip mechanisms cannot be used to achieve circuit disconnection. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a novel thermal tripping mechanism, which essentially provides an effective thermal tripping effect for onboard surge protection devices, while preventing protection devices detached from the circuit board from falling off and affecting the normal use of other functional components.

[0005] The technical solution adopted in this invention is as follows:

[0006] In a first aspect, the present invention provides a thermal tripping mechanism for applying a continuous thrust to a physical leakage protection device disposed on a circuit board, including an anti-drop cover and a base disposed on both sides of the circuit board.

[0007] The circuit board has an opening at the location of the leakage protection device, through which the energy storage mechanism set in the base passes and contacts the leakage protection device, which is fixed to the circuit board by soldering with a low melting point material, and continuously applies a thrust. This thrust gives the leakage protection device a tendency to move toward the anti-drop cover.

[0008] First, the thermal tripping mechanism in this invention provides thermal tripping functionality for physical bleed current protection devices installed on a PCB circuit board. A physical bleed current protection device refers to one or more independent components fixed to the circuit board through soldering or other methods, forming a bleed current protection circuit with the printed circuitry on the board. Unlike ordinary circuit protection devices, this device is connected to a bleed current circuit, which only conducts bleed current when an abnormal pulse current or lightning current occurs in the working circuit, thus preventing damage to chips and components on the main circuit.

[0009] Leakage protection devices typically include zinc oxide varistors, gas discharge pipes, discharge gaps, and induction coils. These devices have a high resistance when normal current is applied, and can be considered as circuit breakers. However, during use, due to continuous surge current impacts or long-term degradation, their initially high resistance gradually decreases, leading to continuous leakage current in the connected circuit. Once this occurs, it affects the electrical safety of the main circuit. Therefore, to mitigate this risk, various types of tripping mechanisms are installed to break the circuit upon leakage current, thus protecting the connected circuit.

[0010] Thermal tripping is a common tripping method. In this invention, the leakage protection device is soldered to the circuit board using a low-melting-point material, providing good fixation at room temperature. The continuous thrust applied by the energy storage mechanism within the base also maintains stability and does not affect its normal leakage function. However, in cases of degradation, continuous leakage current causes it to heat up, which melts the low-melting-point solder material, loosening multiple connections of the leakage protection device. Due to the continuous thrust applied to the leakage protection device, one or more connections disengage, thus breaking the circuit and protecting the entire structure. Compared to existing technologies, the anti-drop cover in this invention restricts the detached leakage protection device, confining it within the cover and preventing it from falling to other locations and affecting the normal operation of the corresponding functional components. Especially since the circuit board is only a part of a larger circuit board, and the electrical equipment is a moving part, any detached device would move around; the added anti-drop cover effectively restricts its movement.

[0011] In conjunction with the first aspect, the present invention provides a first embodiment of the first aspect, wherein the energy storage mechanism has an indicator end, and the anti-drop cover has an indicator window, the indicator end has a clear marking, and when the energy storage mechanism pushes the leakage protection device to operate, the indicator end extends outward from the indicator window to indicate.

[0012] In conjunction with the first aspect, the present invention provides a second embodiment of the first aspect, wherein the anti-drop cover has a hook that is detachably connected to the circuit board.

[0013] A hook is a structure with a protruding end that has a bent part. This part of the structure can deform or rotate and achieves a limiting and fixing effect by engaging with a corresponding structure. Once disassembly is required, external force can be applied to the hook to disengage it from the corresponding structure. At this time, the anti-drop cover can be moved to complete the disassembly.

[0014] In conjunction with the second embodiment of the first aspect, the present invention provides a third embodiment of the first aspect, wherein the base is movably connected to the circuit board, and has a snap-fit ​​on the base, wherein the snap hook passes through the circuit board and through the inside of the base and engages with the snap-fit ​​to tighten and fix the base to the circuit board.

[0015] It is worth noting that both the base and the anti-drop cover are movably connected to the circuit board. The anti-drop cover uses a hook to pass through the circuit board and engage with the base, thus clamping the base and anti-drop cover onto the circuit board. This fixing method offers good assembly and disassembly efficiency. When internal maintenance and inspection are required, the hook can be moved to disconnect the anti-drop cover from the base. At this point, both the anti-drop cover and the base can be removed simultaneously, exposing the circuit board structure inside. The disengaged energy storage mechanism can be restored, and the detached leakage protection device can be removed and soldered on a new one. Finally, the base and anti-drop cover can be reattached to complete the maintenance process, which is convenient, quick, and efficient.

[0016] In conjunction with the third embodiment of the first aspect, the present invention provides a fourth embodiment of the first aspect, wherein the anti-drop cover has at least two positioning posts and a matching positioning hole is provided on the circuit board, and the positioning posts are inserted into the positioning holes when the anti-drop cover is snapped into the base.

[0017] It is worth noting that the positioning pin and positioning hole work together to achieve a snap-fit ​​connection, which can prevent ordinary clamping connection methods from shifting when a certain external force or vibration is transmitted, thus causing the anti-drop cover and base to detach from the area to be covered.

[0018] In conjunction with the third embodiment of the first aspect, the present invention provides a fifth embodiment of the first aspect, wherein the energy storage mechanism includes a spring disposed on a base and a release member connected to the spring, the release member having an end that contacts a leakage protection device, and the spring being in a compressed state when the leakage protection device is fixed on a circuit board.

[0019] In conjunction with the fifth embodiment of the first aspect, the present invention provides a sixth embodiment of the first aspect, wherein the circuit board on one side of the leakage protection device has an opening, and the indicator end is a structure in which the tripping member extends outward and passes through the opening and is retained in the anti-drop cover.

[0020] In conjunction with the first aspect and its first to sixth embodiments, the present invention provides a seventh embodiment of the first aspect, wherein the circuit board has at least two pads, and the connection terminal of the leakage protection device is connected to the corresponding pad by a low-temperature soldering method.

[0021] The beneficial effects of this invention are as follows:

[0022] The thermal tripping mechanism provided by this invention is used in conjunction with the leakage protection device installed on the circuit board. Through the energy storage mechanism, a pushing force is continuously applied to the leakage protection device, so that it can promptly break contact when the deteriorated short circuit heats up and the fixed connection part of the circuit board melts, thereby achieving a better passive tripping protection effect.

[0023] Meanwhile, the anti-drop cover and the base are designed to work together to clamp and fix the device to the circuit board. The anti-drop cover also collects any fallen leakage protection devices, preventing them from moving around after being thermally tripped off the circuit board and thus affecting the normal operation of other functional devices on the same circuit board or in the same housing. Attached Figure Description

[0024] Figure 1 This is a first axial side view of the assembly state of a portion of the circuit board in Embodiment 1 of the present invention;

[0025] Figure 2 This is a second axial side view of the assembly state of a portion of the circuit board in Embodiment 1 of the present invention;

[0026] Figure 3 This is a side view of the assembly state of a portion of a circuit board in Embodiment 1 of the present invention;

[0027] Figure 4 This is the present invention. Figure 3 A schematic diagram of the cross-section after cutting along line AA.

[0028] Figure 5 This is a side view of the split state of a portion of the circuit board in Embodiment 1 of the present invention;

[0029] Figure 6 This is a first axial side view of the split state of a portion of the circuit board in Embodiment 1 of the present invention;

[0030] Figure 7 This is a second axial view of the split state of the circuit board in Embodiment 1 of the present invention;

[0031] In the diagram: 1-Circuit board, 1.1-Pad, 2-Anti-drop cover, 2.1-Hook, 2.2-Positioning post, 2.3-Indicator window, 3-Base, 3.1-Hook, 4-Releasing component, 5-Drainage protection device, 6-Spring. Detailed Implementation

[0032] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0036] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0038] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] Example 1:

[0040] This embodiment discloses a novel thermal tripping mechanism, which is installed in an electrical device with an SPD protection module. The SPD protection module is a circuit structure installed on a PCB circuit board 1 and has one or more physical leakage protection devices 5, which are fixed on the PCB circuit board 1 by low-temperature soldering.

[0041] Specifically, such as Figure 1 As shown in the figure, only a portion of the PCB of the electrical equipment is displayed, which is represented by a square sheet-like circuit board 1. The circuit board 1 contains a portion of the SPD module circuitry for the electrical equipment, and two pads 1.1 are provided on its upper surface. The two connection terminals of the leakage protection device 5 are connected to the pads 1.1 by low-temperature soldering.

[0042] As shown in the figure, the leakage protection device 5 has a cuboid structure and is attached to the middle of the circuit board 1. A cover 2 is provided on the upper part of the leakage protection device 5 to cover it. The cover 2 is a plastic part with a rectangular structure and a groove at the bottom to accommodate the leakage protection device 5 and other components.

[0043] Two symmetrically arranged, downward-protruding strips extending a certain length are provided on the edge of the groove opening at the lower part of the anti-drop cover 2, and a hook 2.1 structure is provided at the end of the strip. As can be seen in the figure, the hook 2.1 protrudes to both sides, and two openings are provided on both sides of the circuit board 1 where the leakage protection device 5 is provided, allowing the hook 2.1 to pass through the circuit board 1 and engage.

[0044] Furthermore, a base 3 structure is provided at the lower part of the circuit board 1. Similar to the anti-drop cover 2, the base 3 is also snapped and fixed to the circuit board 1. A groove is provided in the base 3, and a columnar body is provided in the groove. A spring 6 is sleeved on the columnar body.

[0045] As not shown in the figure, the circuit board 1 in this embodiment also has an opening in the middle, which is smaller than the maximum external lateral cross-sectional size of the leakage protection device 5. This opening is connected to the two openings through which the hooks 2.1 pass and engage, and the leakage protection device 5 is located at the upper edge of this opening.

[0046] At the bottom of the leakage protection device 5, there is a release element 4 that fits against it. The release element 4 has a contact end face, and its bottom is connected to the end of the spring 6, which provides an upward thrust. An upwardly extending indicator end is also provided on the contact end face; this indicator end is a protrusion integrally formed with the release element 4, as shown in the figure. This structure does not contact the leakage protection device 5, but passes through the aforementioned opening into the circuit board 1 and extends a certain distance, with a marking surface at its end. This marking surface may have a conspicuous color, pattern, or other design, and remains inside the anti-drop cover 2 when not in use. Because it is integrally formed with the release element 4, when the release element 4 is activated, it moves upward simultaneously, eventually passing through the anti-drop cover 2 and indicating outward that the leakage protection device 5 inside the device has disengaged from the circuit board 1 and requires timely maintenance or replacement.

[0047] The so-called thermal tripping occurs when the leakage protection device 5 deteriorates and fails, resulting in continuous leakage current. The device heats up, causing its low-temperature solder joint to melt and break. The compressed spring 6 then pushes the tripping component 4 upwards, breaking the circuit and preventing a fire hazard caused by continuous heating. Furthermore, due to the anti-drop cover 2 structure, existing onboard thermal tripping devices, after tripping and falling off, can move freely within the circuit board 1 housing of the electrical equipment, potentially affecting its normal operation. This anti-drop cover 2 confines the leakage protection device 5 within a certain space, allowing for direct removal after the cover is removed, making it convenient and efficient.

[0048] Example 2:

[0049] This embodiment is an optimization and adjustment based on the above embodiment 1, such as... Figure 2-7 As shown, there are two latches 3.1 at the bottom of the base 3. By increasing the length of the two hooks 2.1 on the lower side of the anti-drop cover 2, they can pass through the circuit board 1 and continue downward, and finally pass out of the base 3 and engage with the edge of the latch 3.1 of the base 3 to achieve latching and limiting.

[0050] Unlike embodiment 1, the anti-drop cover 2 and the base 3 are not directly connected to the circuit board 1. Instead, the base 3 is pulled tight by two hooks 2.1 on the anti-drop cover 2 that pass through the circuit board 1, so that the anti-drop cover 2 and the base 3 are clamped together on the circuit board 1, thereby achieving a detachable and fixed effect.

[0051] Meanwhile, to prevent the two structures mentioned above from shifting on the circuit board 1, a positioning post 2.2 is provided at each of the four corners of the bottom of the anti-fall cover 2 in this embodiment. Figure 2 As can be seen, corresponding positioning holes are provided on the circuit board 1. When the anti-drop cover 2 is attached to the surface of the circuit board 1, the positioning post 2.2 is inserted into the positioning hole to achieve horizontal positioning.

[0052] Meanwhile, to achieve better feedback, an indicator window 2.3 is provided on the top surface of the anti-fall cover 2. When assembled and fixed, the end face of the indicator of the tripping component 4 is flush with the plane of the indicator window 2.3. When the internal leakage protection device 5 trips, the indicator end of the tripping component 4 moves upward and extends a certain length through the indicator window 2.3. Due to its obvious color difference, it can be quickly found that the device inside the anti-fall cover 2 has tripped during maintenance.

[0053] The entire installation, operation, and maintenance process of the equipment is as follows:

[0054] First, fix the connection ends on both sides of the leakage protection device 5 to the pads 1.1 of the circuit board 1 by low temperature soldering. Then, install the spring 6 on the cylinder of the base 3 and move it to the lower part of the circuit board 1 so that the upper end face of the release piece 4 connected to the end of the spring 6 contacts the bottom of the leakage protection device 5.

[0055] Then, the hook 2.1 at the bottom of the anti-drop cover 2 is passed through the opening of the circuit board 1, and the base 3 and the anti-drop cover 2 are clamped together towards the circuit board 1, so that the hook 2.1 is inserted into the base 3 and passes out from the slot 3.1. Thus, when a fixed connection is formed, the spring 6 can also be compressed and continuously push the release piece 4 upward, and the positioning post 2.2 is also inserted into the positioning hole to achieve the limit.

[0056] In use, when the leakage protection device 5 deteriorates and fails, short-circuiting and begins to generate heat, the heat is transferred to the low-temperature solder joint. When the solder structure at one or both joints melts, and its connection strength is less than the thrust of the spring 6, the tripping component 4 can push it upward, either as a whole or on one side, thus forming an open circuit. At this time, the indicator end of the tripping component 4 extends out from the indicator window 2.3 to issue a warning.

[0057] During maintenance, if the indicator end is found to be protruding, push the two side hooks 2.1 towards the center to disengage them from the latch 3.1. Then, slowly remove the anti-drop cover 2 and the base 3 to expose the surface of the circuit board 1 it covers. Replace the components according to the disengagement situation. Finally, fasten the anti-drop cover 2 and the base 3 to complete the maintenance work.

[0058] This invention is not limited to the optional embodiments described above, and anyone can derive other various forms of products based on the inspiration of this invention. The specific embodiments described above should not be construed as limiting the scope of protection of this invention; the scope of protection of this invention should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A thermal tripping mechanism for applying a continuous thrust to a physical leakage protection device (5) disposed on a circuit board (1), characterized in that: Includes anti-drop covers (2) and bases (3) set on both sides of the circuit board (1); The circuit board (1) has an opening at the location where the leakage protection device (5) is provided, so that the energy storage mechanism set in the base (3) can pass through the opening and contact the leakage protection device (5) fixed on the circuit board (1) by welding with low melting point material and continuously apply a pushing force, which gives the leakage protection device (5) a tendency to move towards the anti-drop cover (2). The energy storage mechanism has an indicator end, and the anti-drop cover (2) has an indicator window (2.3). The indicator end has a clear mark. When the energy storage mechanism pushes the leakage protection device (5) to operate, the indicator end extends outward from the indicator window (2.3) to indicate. The anti-drop cover (2) has a hook (2.1) which is detachably connected to the circuit board (1). The base (3) is movably connected to the circuit board (1). The base (3) has a slot (3.1). The hook (2.1) passes through the circuit board (1) and through the inside of the base (3) and engages with the slot (3.1) to tighten and fix the base (3) on the circuit board (1). The anti-drop cover (2) has at least two positioning posts (2.2) and a matching positioning hole is provided on the circuit board (1). When the anti-drop cover (2) is engaged with the base (3), the positioning posts (2.2) are inserted into the positioning hole. The energy storage mechanism includes a spring (6) disposed on a base (3) and a release member (4) connected to the spring (6). The release member (4) has an end that contacts the leakage protection device (5). When the leakage protection device (5) is fixed on the circuit board (1), the spring (6) is in a compressed state.

2. The thermal tripping mechanism according to claim 1, characterized in that: The circuit board (1) on one side of the leakage protection device (5) has an opening, and the indicator end is a structure in which the tripping member (4) extends outward and passes through the opening and is retained in the anti-drop cover (2).

3. A thermal tripping mechanism according to claim 1 or 2, characterized in that: The circuit board (1) has at least two pads (1.1), and the connection end of the leakage protection device (5) is connected to the corresponding pad (1.1) by low temperature soldering.

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