Molded case circuit breakers

Abstract

The present invention provides a fully enclosed circuit board protective structure and a molded case circuit breaker, belonging to the field of circuit breaker structures. By providing a fully enclosed circuit board protective structure, the present invention enables the circuit board to be located in an independent space separated from the interior of the circuit breaker after installation. By making the space where the circuit board is located independent, the airflow containing micro-metal particles generated by the opening action is effectively prevented from rushing to the circuit board accessories and adhering to the circuit board, thereby affecting the insulation performance of the circuit board. This ensures that the circuit board is not affected by the opening and closing actions and is in normal working condition in real time.

Description

Technical Field

[0001] The present invention relates to the field of circuit breakers, and in particular to a protective structure for performing closed protection on a circuit board at the back of the circuit breaker and a molded case circuit breaker using the protective structure. Background Art

[0002] Currently, circuit breakers on the market, such as molded case leakage circuit breakers, universal circuit breakers, and frame-type circuit breakers, are equipped with circuit boards. These boards are mounted on the breaker's base or secured within a plastic cover. These circuit boards are open or semi-open. When the circuit breaker trips under high current, the contact resistance of the moving and static contacts increases dramatically, causing a sudden temperature rise. The high temperature burns and vaporizes the contact areas of the moving and static contacts. Microscopic metal particles generated by contact vaporization are sprayed throughout the product by air pressure. These microscopic metal particles can coat the surface of the circuit board, degrading the insulation between components. When power is applied, components can short-circuit, causing malfunctions. In severe cases, these components can burn out, rendering the circuit breaker's leakage protection and other features ineffective, endangering user safety.

[0003] Based on this, this application is filed. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a fully enclosed circuit board protection structure and a molded case circuit breaker, which effectively protect the circuit board part in a fully enclosed manner, prevent metal particles generated by the opening action from adhering to the circuit board and affecting the normal performance of the circuit board, enable the circuit breaker to operate normally, and ensure power safety.

[0005] To achieve the above-mentioned purpose, the fully enclosed circuit board protection structure of the present invention (hereinafter referred to as the first type of protection structure) is as follows:

[0006] The bracket has a closed bottom and an upper portion provided with a mounting surface for mounting a circuit board, with a certain height between the upper portion and the bottom portion; the mounting surface is surrounded by an inner edge, and one side of the inner edge is provided with an edge notch adapted to the width of a socket on the mating circuit board;

[0007] The outer edge is arranged on the inner side of the cover or middle cover of the circuit breaker, and its shape and size are adapted to the installation plane. The outer edge buckle is placed on the outer side of the inner edge, and the inner side wall thereof is provided with a clearance fit with the outer side wall of the inner edge.

[0008] The upper shielding surface is arranged on the face shield or middle cover of the circuit breaker. It is arranged opposite to the mounting plane and contacts with the outer peripheral edge to shield the upper part of the mounting plane. The upper shielding surface is provided with an opening for the buttons, handles and other operating structures on the circuit board to pass through.

[0009] Preferably, the height of the outer edge is not less than the height of the inner edge.

[0010] Through the above structure, the inner edge, outer edge, and bracket cooperate to form an internal space that is relatively independent of the internal space of the circuit breaker, thereby preventing air from flowing into the space where the circuit board is located between the internal space between the middle cover and the base, or between the mask and the base (without the middle cover). This effectively prevents micro-metal particles generated by the opening action from adhering to the circuit board under the action of air pressure, ensuring the normal operation of the circuit board.

[0011] Furthermore, the above technical solution isolates the circuit board from the outside world by arranging an upper mask surface in cooperation with the outer edge, thereby reducing the external influence on the circuit board.

[0012] The present invention is further configured as follows: inner edges are provided on three side surfaces around the mounting plane, and bosses are protruding from the edges of the inner edges adjacent to the sides without edges, and the gap between the boss and the edge of the inner edges on the opposite side or between the boss and the boss on the edge of the inner edges on the opposite side forms an edge gap, and the mounting opening is adapted to the width of the connector on the mating circuit board.

[0013] The above technical solution controls the size of the opening on the side without the inner edge by providing a boss structure, adapting it to the width of the connector of the installed circuit board. After the circuit board is installed on the bracket, the connector and the edge or boss engage and fit tightly together, minimizing the gap there, effectively sealing this side and reducing the risk of micro-metal particles entering and contacting the circuit board through this area. Furthermore, the advantage of the boss structure employed in this invention is that the boss can be integrally formed with the inner edge, eliminating the inconvenience of further machining the already formed inner edge. Furthermore, it prevents the gap from widening due to machining errors during slotting or opening, which could lead to insufficient sealing on this side.

[0014] In summary, by adopting the above technical solution, the sealing of the installation location can be ensured while the installation of the socket is achieved.

[0015] The present invention is further configured as follows: the outer edge is arranged on the middle cover,

[0016] The present invention is further configured as follows: the gap between the inner peripheral edge and the outer peripheral edge is 0.1-0.5 mm.

[0017] The present invention is further configured as follows: a mounting groove for installing an indicator button is provided in the middle of the bracket, a mounting channel connected to the mounting groove is opened on the side wall of the bracket, and the opening of the mounting channel on the side wall of the bracket is closed by a baffle whose shape is adapted to the opening.

[0018] The present invention is further configured as follows: the bottom of the bracket is provided with pins for plugging and cooperating with the base.

[0019] The present invention is further configured as follows: it also includes a pressing portion, which is configured on the middle cover or the mask together with the outer edge, and is pressed and matched with the pins at the bottom of the bracket.

[0020] The present invention is further configured as follows: a cavity for installing a coil, a dynamic and static iron core, and a transmission hook is provided in the middle of the bracket; the installation coil, the dynamic and static iron core, the transmission hook and the circuit board are combined to form a leakage release.

[0021] The present invention also provides another fully enclosed circuit board protection structure (hereinafter referred to as the second type of protection structure), which is different from the above structure. It adopts a cover-type structural design. The specific structure is as follows:

[0022] The cover is closed on all sides along its length and has an L-shaped opening on the top. The L-shaped opening is formed by the main opening and the side openings vertically interconnected. A fixing structure for fixing the circuit board is configured inside the cover, and mounting feet are provided near the bottom.

[0023] The protective cover is configured to close the L-shaped opening on the cover body, including a main cover body corresponding to the main opening and a side cover body with comb-shaped grooves perpendicular to the side opening. It is also configured with a connection structure that is fixedly connected or detachably fixedly connected to the cover body.

[0024] By combining the housing and the protective cover of the above-mentioned technical solution, the present invention provides a vertical fully enclosed circuit board protection structure. Unlike the aforementioned horizontal fully enclosed circuit board protection structure, the protection structure provided by the present technical solution occupies a small space on the horizontal plane and can be installed in a circuit breaker where the horizontal installation space is limited but the vertical installation space is relatively abundant.

[0025] In order to simplify the parts structure and reduce production costs, the above-mentioned second type of protection structure is further configured as follows: the bottom of the cover body is also provided with an opening, which is used to contact and cooperate with the bottom surface or side surface of the circuit breaker to be closed.

[0026] To facilitate installation, the above-mentioned second type of protective structure is further configured as follows: the fixed structure is a guide groove arranged along the inner side wall of the cylindrical cover in the length direction, and the number of the guide grooves is preferably 2 and the 2 guide grooves are arranged opposite to each other.

[0027] In order to facilitate the introduction of the sensor wires, the second type of protective structure is further configured as follows: a wiring gap is further provided on the L-shaped opening, and a shielding protrusion opposite to the wiring gap is provided on the protective cover.

[0028] The structure of the molded case circuit breaker of the present invention is specifically as follows: it includes a base, a mask, a middle cover, a tripper component, a tripper circuit board, a wire harness group, a leakage signal detection and amplification circuit board, and the above-mentioned two types of fully enclosed circuit board protection structures. The tripper component is installed in the cavity inside the bracket of the first type of protection structure, and the bracket is plugged into the base through the pins at its bottom; the tripper circuit board is installed on the mounting plane on the upper part of the bracket; the leakage signal detection and amplification circuit board is installed in the second type of protection structure, and the cover body is fixedly connected to the base through the mounting angle at its bottom; the socket on the leakage signal detection and amplification circuit board is electrically connected to the socket on the tripper circuit board through the wire harness group; the outer edge is provided on the bottom surface of the middle cover, and the upper shield surface is located on the bottom surface of the mask, and the middle cover and the mask are sequentially covered on the base.

[0029] The above technical solution distributes the circuit structure required for the leakage tripping protection structure of the molded case circuit breaker to two circuit boards, disperses the original large-volume circuit boards into a small space by segmentation, and encloses the circuit boards through protective structures. While setting up protective structures to protect the circuit boards to improve the protection level of the circuit boards, it also effectively prevents the protective structures from occupying too much internal space of the circuit breaker.

[0030] In addition, the present invention allocates different functions to different circuit boards, which not only reduces the risk of simultaneous damage to the circuit boards, but also reduces the maintenance cost when the damaged circuit boards need to be replaced.

[0031] The above structure is further configured as follows: the first type of protection structure and the second type of protection structure are adjacently arranged and are arranged opposite to each other on one side of the outlet for installing the socket.

[0032] The above technical solution brings the two circuit boards very close together, making it easy to plug and match them with the wire harness assembly, while also reducing the space required to install the circuit boards, reducing unnecessary space occupied inside the circuit breaker, and optimizing space utilization.

[0033] The above structure is further configured as follows: the first type of protective structure is disposed across the operating mechanism mounted on the base, allowing the trip unit to control the operating mechanism to disconnect the connected circuits in the circuit breaker, thereby saving on parts. Furthermore, this structure is simplified and compact, improving the efficient use of space.

[0034] The above structure is further configured as follows: the second type of protective structure is sandwiched between or inserted between the terminal blocks. On the one hand, this structural design facilitates the close proximity of the second type of protective structure and the circuit board therein to the first type of protective structure, facilitating connectivity; on the other hand, this structural design fully utilizes the extra space between the terminal blocks and the center of the base, cleverly utilizing this small space.

[0035] The beneficial effects of the present invention are as follows: By providing a fully enclosed protective structure for the circuit board, the present invention allows the circuit board to be located in an independent space separated from the interior of the circuit breaker after installation. By making the space where the circuit board is located independent, the airflow containing micro-metal particles generated by the opening action is effectively prevented from rushing to the circuit board accessories and adhering to the circuit board, thereby affecting the insulation performance of the circuit board. This ensures that the circuit board is not affected by the opening and closing actions and is in normal working condition in real time.

[0036] For example, the molded case circuit breaker adopting this protective structure in the present invention can effectively protect the control circuit of the tripping action corresponding to its leakage function and the effectiveness of the corresponding circuit structure for detecting whether there is leakage, thereby ensuring that the molded case leakage circuit breaker functions normally in the power grid or low-voltage circuit and protects the power installation.

[0037] Furthermore, the protective structure of the present invention is simple and easy to assemble, which provides certain convenience for subsequent operations such as later supervision and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of a molded case circuit breaker according to a specific embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the first type of protection structure in a specific embodiment of the present invention.

[0040] Figure 3 It is a schematic diagram of the support structure of a specific embodiment of the present invention.

[0041] Figure 4 The figure is a schematic diagram of the circuit board structure of a release according to a specific embodiment of the present invention.

[0042] Figure 5 The figure is a schematic diagram of the structure of the indicator button according to a specific embodiment of the present invention.

[0043] Figure 6 Schematic diagram of the baffle structure according to a specific embodiment of the present invention.

[0044] Figure 7 This is a schematic diagram of the second type of protective assembly state of a specific embodiment of the present invention.

[0045] Figure 8 This is a schematic diagram of the second type of protection structure in a specific embodiment of the present invention.

[0046] Figure 9 This is an overall schematic diagram of the second type of protection in a specific embodiment of the present invention.

[0047] Figure 10 It is an overall schematic diagram of the cover body according to a specific embodiment of the present invention.

[0048] Figure 11It is a schematic diagram of the internal structure of the cover body according to a specific embodiment of the present invention.

[0049] Figure 12 This is a schematic diagram of the structure of a leakage signal detection and amplification circuit board according to a specific embodiment of the present invention.

[0050] Figure 13 It is a schematic diagram of the protective cover structure of a specific embodiment of the present invention.

[0051] Figure 14 This is a schematic diagram of the structure of a wire harness group according to a specific embodiment of the present invention.

[0052] Figure 15 It is a schematic diagram of the base structure of a specific embodiment of the present invention.

[0053] Figure 16 Schematic diagram of the bottom structure of the cover in a specific embodiment of the present invention.

[0054] Figure 17 It is a schematic diagram of the partial structure of the front side of the cover in a specific embodiment of the present invention.

[0055] Figure 18 It is a schematic diagram of the bottom structure of the mask according to a specific embodiment of the present invention.

[0056] Figure 19 This is a schematic diagram of the first type of protective structure status in a specific embodiment of the present invention.

[0057] Figure 20 This is a schematic diagram of the second type of protective structure status in a specific embodiment of the present invention.

[0058] Reference numerals: 1—circuit breaker, 2—trip circuit board, 3—bracket, 4—indicator button, 5—baffle, 6—leakage signal detection and amplification circuit board, 7—housing, 8—protective cover, 9—wire harness assembly, 10—base, 11—middle cover, 12—face mask;

[0059] 2-1—Connector 1, 2-2—Side notch, 2-3—Middle opening, 2-4—Positioning opening, 3-1—Mounting plane, 3-2—Inner edge, 3-3—Side boss, 3-4—Positioning boss, 3-5—Mounting opening, 3-6—Mounting slot, 3-7—Connector slot, 3-8—Pin 1, 5-1—Connector pin, 5-2—Blocking wall, 7-1—Upper opening, 7-2—Mounting guide groove, 7-3—Connector guide groove, 7-4—Termination surface, 7-5—Reaching notch, 7-6—Positioning cylinder, 6-1—PCB body, 6-2—Connector 2, 6-3 —Bottom of the circuit board, 8-1—Pin 2, 8-2—Side cover, 8-3—Comb-shaped groove, 8-4—Routing boss, 8-5—Wire outlet notch, 9-1—Connector 1, 9-2—Connector 2, 10-1—Slot 1, 10-2—Rectangular groove, 10-3—Location hole, 11-1—Middle cover cavity, 11-2—Location plane, 11-3—Outer edge 1, 11-4—Accessory opening 1, 11-5—Accessory opening 2, 11-6—Outer edge 2, 12-1—Accessory opening 3, 12-2—Accessory opening 4, 12-3—Upper mask surface. DETAILED DESCRIPTION

[0060] The main purpose of the present invention is to provide a fully enclosed circuit protection structure for enclosing the circuit board in a circuit breaker 1 in an independent cavity. By making the space where the circuit board is located independent of the interior of the circuit breaker 1, the circuit board can be protected from being affected by the gas with a certain pressure that entrains micro-metal particles when the circuit breaker 1 is opened, thereby ensuring the normal operation of the circuit board and its corresponding circuit breaker 1 and guaranteeing electrical safety.

[0061] The structure is described in detail below with reference to specific embodiments.

[0062] It should be noted that the orientation concepts described in the present invention are all described with the base of the circuit breaker 1 as a reference.

[0063] Example 1 Figure 2 As shown, this embodiment provides a fully enclosed circuit board protection structure in which the circuit board can be installed parallel to the base, which includes a bracket 3, an outer edge and an upper mask surface 12-3. Figure 3As shown, bracket 3 has a horizontal mounting surface 3-1. Since circuit boards are often rectangular in practical applications, this embodiment uses a rectangular mounting surface 3-1, which is compatible with rectangular circuit boards, as an example. Below one side of mounting surface 3-1 is a central cavity connected to mounting surface 3-1, resulting in a generally L-shaped bracket 3. To facilitate installation and positioning of bracket 3, four pins 3-8 are positioned at the bottom of the outer wall of the central cavity, distributed at the four corners. The insertion direction of pins 3-8 can be customized based on actual assembly needs; for example, the insertion directions of all four pins 3-8 can be aligned or varied.

[0064] Mounting surface 3-1 has inner edges 3-2 on its two long sides and one short side, surrounding mounting surface 3-1. The short sides of mounting surface 3-1 where inner edges 3-2 are not provided have edge notches. Symmetrical side bosses 3-3 protrude from the inner edges 3-2 on opposite sides near the edge notches. The gap between the two symmetrical side bosses 3-3 forms the edge notch, which is adapted to the width of the connector on the mating circuit board.

[0065] In the above structure, bracket 3 can be integrally injection-molded, facilitating processing and eliminating assembly. The central cavity of bracket 3 provides space for independently mounted electronic components, such as moving and stationary cores, coils, drive hooks, independent buttons, and dials. The open slotted structure formed by the combination of mounting plane 3-1 and the three inner edges 3-2 on bracket 3 is used to mount a horizontally mounted circuit board. The notches along the edges of mounting plane 3-1 are used to mount connectors. Consequently, the bottom of bracket 3 and the surroundings of mounting plane 3-1 are obscured, leaving only the top of bracket 3 open.

[0066] Combine Figure 19 As shown, the outer edge is a convex edge protruding from the bottom of the bottom surface of the middle cover 11, and the convex edge is preferably configured as a rectangular frame structure with a shape and size that is adapted to the installation plane 3-1; combined Figure 18 and Figure 19 As shown, the upper mask surface 12-3 is the portion of the mask 12 body directly opposite the mounting plane 3-1. It can contact and fit with the outer edge, forming a closed covering structure with it, so as to interlock with the top of the bracket 3 below it (i.e., the mounting plane 3-1 and the inner edge 3-2). The outer edge is placed outside the inner edge 3-2, and its inner sidewall is provided with a clearance of 0.1-0.5mm with the outer sidewall of the inner edge 3-2. In addition, to ensure a good sealing effect, the height of the outer edge is preferably not less than that of the inner edge 3-2.

[0067] Since there is a certain gap between the middle cover 11 and the mask 12 in the above structure, in a preferred specific embodiment, the outer edge not only includes the outer edge 11-3 set on the bottom of the middle cover 11, but also includes the outer edge 11-6 extending to the front of the middle cover 11. The outer edge 11-3 is gap-fitted with the inner edge 3-2, and the outer edge 11-6 is in contact with and sealed with the upper mask surface 12-3, finally forming a relatively closed space above the mounting plane 3-1.

[0068] Of course, in another specific embodiment, the circuit breaker 1 has no middle cover 11 but only has the mask 12 , then the outer edge and the upper mask surface 12 - 3 are both provided on the mask 12 and buckled with the top of the bracket 3 .

[0069] Also, considering that in actual applications, the circuit board is usually provided with buttons, dial handles and other structures, the upper mask surface 12-3 can be provided with buttons, dial handles and other operating structures on the circuit board. Since the specific implementation of the first 2 to 3 paragraphs is provided with a middle cover 11 and the middle cover 11 and the mask 12 are independent, the middle cover 11 and the mask 12 are respectively provided with the following Figure 17 and Figure 18 The accessory opening one 11-4, accessory opening two 11-5, accessory opening three 12-1, and accessory opening four 12-2 opened above correspond to each other in position.

[0070] During assembly and use, the circuit board can be directly placed on the mounting plane 3 - 1 from above the bracket 3 . After assembly, the outer edge and the upper mask surface 12 - 3 form a closed shielding structure to seal the upper side of the bracket 3 .

[0071] Example 2 This example is further configured as follows on the basis of the various specific implementation methods described in Example 1: In view of the need to install independent buttons and other structures in the central cavity of the bracket 3, in order to fix the independent buttons and other structures, this example provides an installation opening 3-5 on the side wall of the central cavity connected to the inner peripheral edge 3-2 above it. The installation opening 3-5 is connected to the installation groove inside the central cavity for installing independent buttons and other structures. In this way, independent buttons and other structures can enter the installation groove from the side through the installation opening 3-5 and be fixedly installed. While facilitating assembly, it also avoids the inconvenience caused to the installed parts by the installation method of inserting from the top of the bracket 3 downward.

[0072] Since this embodiment requires all-round protection of the circuit board, a plug-in slot 3-7 is provided at the installation opening 3-5 on the side wall of the bracket 3 of the installation channel. A baffle 5 is plugged into the plug-in slot 3-7. The shape of the baffle 5 is adapted to the installation opening 3-5, and a plug-in pin 5-1 that cooperates with the plug-in slot 3-7 is also provided at the bottom. After the independent button is installed, the baffle 5 is inserted into the plug-in slot 3-7 to close the opening.

[0073] In the above embodiment, in order to ensure that the bracket 3 is stably fixed between the middle cover 11 and the base or the mask 12 and the base after installation, a pressing portion can also be provided on the bottom surface of the middle cover 11 or the mask 12, such as Figure 16 As shown, the pressing portion can be an annular abutting surface or a pressing foot that presses against pin 1 3-8. The structure of the abutting portion can be adjusted according to the model and internal design of the circuit breaker 1. It only needs to ensure that its length and height are sufficient to abut against pin 1 3-8 and press against the fixed structure mounted on the bracket 3. Accordingly, the height of the inner edge 3-2 and the outer edge is also adapted to the circuit board to be installed.

[0074] Example 3 Figure 8 As shown, this embodiment provides a fully enclosed circuit board protection structure that can make the circuit board stand upright and achieve sealing, which includes a cover body 7 and a protective cover 8. The cover body 7 is tubular, its sides are closed, and the top and bottom are respectively provided with an upper opening and a lower opening.

[0075] like Figure 10 As shown, the upper opening is an L-shaped opening, which is formed by the main opening and the side opening vertically connected to each other: the size of the main opening is the size of the horizontal surface of the cover body 7, and the side opening is smaller in height and can be used to lead out wires from the socket on the circuit board installed in the cover body 7 - so it can be set to a relatively flat shape. Figure 7 、 Figure 11 As shown, the housing 7 is provided with an installation insertion guide groove 7-2 for fixing the circuit board in the width direction thereof. The installation insertion guide groove 7-2 preferably has two symmetrical grooves on opposite sides of the housing 7. The groove width of the installation insertion guide groove 7-2 is adapted to the thickness of the circuit board. The length of the installation insertion guide groove 7-2 is not less than the length of the circuit board but less than the length of the housing 7. Therefore, when installing the circuit board, it is only necessary to insert the circuit board into the installation insertion guide groove 7-2 from the upper opening and push the circuit board along the installation insertion guide groove 7-2 until the bottom of the circuit board contacts the end surface 7-4 at the bottom of the installation insertion guide groove 7-2. The installation insertion guide groove 7-2 not only serves as an installation guide, but also serves to fix the circuit board at a specific position in the housing 7 and prevent the circuit board from unnecessary displacement relative to the housing 7.

[0076] like Figure 13As shown, the protective cover 8 is used to close the upper opening. Therefore, its structure is adapted to the upper opening and includes a corresponding main cover body and a side cover body 8-2 corresponding to the side opening. At the same time, in order to fix it to the cover body 7, a corresponding plug-in structure is also provided, such as a second pin 8-1 on the side edge of the bottom of the main cover body and a corresponding slot 2 provided on the cover body 7. Since the side opening is used to lead wires from the socket of the circuit board for external connection, in this embodiment, a comb-shaped groove 8-3 can be provided on the side cover body 8-2. The combing groove can allow multiple wires or a row of wire bundles 9 to pass through.

[0077] When installing the circuit board into the housing 7, insert a wire harness 9 into the socket opposite the side opening. Then, align and insert pin 2 8-1 on the protective cover 8 with slot 2 on the housing 7. At the same time, pay attention to combing the wires on the wire harness 9 so that they pass evenly through the comb-shaped grooves 8-3. This completes the fully enclosed assembly of the circuit board. Finally, the lower opening of the bottom of the housing 7 is brought into contact with the surface of the fixed structure to be installed, and the assembly is completed.

[0078] In a preferred embodiment, to facilitate signal connection between the circuit board and external transformers, a routing notch 7-5 is provided in the main opening, and a corresponding routing boss 8-4 is provided on the protective cover 8. When the bottom surface of the protective cover 8 rests against the end surface of the upper opening of the housing 7, the routing boss 8-4 fits neatly into the routing notch 7-5, thereby supporting the signal lines required for signal connection. The height of the routing boss 8-4 is smaller than that of the routing notch 7-5, and the remaining small gap after mating is just enough for the signal lines to pass through.

[0079] This embodiment provides a molded case circuit breaker 1, comprising a base 10, a face shield 12, a middle cover 11, a trip unit component, a trip unit circuit board 2, a wire harness assembly 9, a leakage signal detection and amplification circuit board 6 (i.e., a control circuit board), a first fully enclosed circuit board protective structure for mounting the trip unit circuit board 2, and a second fully enclosed circuit board protective structure for mounting the leakage detection and amplification circuit board. The first fully enclosed circuit board protective structure adopts the horizontally mounted circuit board protective structure provided in embodiment 1, while the second fully enclosed circuit board protective structure adopts the vertically mounted circuit board protective structure provided in embodiment 2.

[0080] Among them, the trip circuit board 2, the bracket 3, the indicator button 4 and the baffle 5 constitute the leakage protection action module a (see Figure 2 , referred to as leakage release); leakage signal detection and amplification circuit board 6, cover 7, protective cover 8 and wire harness group 9 constitute leakage signal detection and amplification module b (see Figure 7 , referred to as controller).

[0081] As described in Example 1, the first fully enclosed circuit board protection structure includes a bracket 3, outer edge 11-3 and outer edge 2 11-6 provided on the middle cover 11, an upper shielding surface 12-3 provided on the face shield 12 and representing a surface of the face shield 12, and a baffle 5. The bracket 3 includes a mounting surface 3-1, an inner edge 3-2, a central cavity, and pin 1 3-8. The trip device is mounted in the central cavity. The sidewall of the central cavity is provided with an actuation opening. The actuation opening is used to allow an actuation rod installed in the central cavity to extend to the operating mechanism installed on the base 10 for linkage. This allows the trip device to actuate and drive the operating mechanism to disconnect the connected circuit. Given the enclosed design, the actuation opening is shaped to accommodate the actuation rod.

[0082] The trip unit's corresponding indicator button 4 needs to be linked to the trip unit components and therefore requires independent installation. Therefore, a corresponding button mounting slot is provided in the central cavity. This slot communicates with a mounting opening 3-5 provided on the side wall of the bracket 3. The indicator button 4 enters the central cavity through the mounting opening 3-5 and is installed in the mounting slot. A baffle 5 is inserted into the mounting opening 3-5, and its shape is adapted to seal the mounting opening 3-5.

[0083] The trip unit circuit board 2 is mounted on the mounting surface 3-1. A central opening 2-3 is provided in the center of the circuit board 2 for the indicator button 4 to pass through. A positioning opening 2-4 is also provided for the positioning boss 3-4 on the mounting surface 3-1 to position and secure the trip unit circuit board 2. To accommodate the edge notch formed by the side boss 3-3, the portion of the circuit board housing the connector 2-1 is machined to match its width. This allows it to contact and mate with the side boss 3-3, sealing the edge notch on the side of the connector 2-1 and preventing air from entering.

[0084] After the circuit board is installed, the bracket 3 and the tripper assembly and the tripper circuit board 2 thereon can be installed on the base 10 together by plugging and matching the four pins 3-8 at the bottom of the bracket 3 with the corresponding slots 10-1 on the base 10.

[0085] The second fully enclosed circuit board protective structure includes a housing 7 and a protective cover 8. Housing 7 is provided with mounting guide grooves 7-2, guide slots, and routing notches 7-5. Protective cover 8 is provided with pin 2 8-1, comb-shaped grooves 8-3, and a wire entry boss. One end of the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board) is provided with a second socket 6-2 and a third socket for connecting to the transformer's signal line. Socket 2 6-2 is located at one end of the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board), near its edge. With the other end of the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board) serving as the base, the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board) is fully inserted through the upper opening of housing 7 along its mounting guide grooves 7-2, allowing the portion of socket 2 facing the side opening to be visible through the side opening. Before fully inserting the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board), the corresponding wire harnesses 9 and connecting wires must be connected to sockets 2 and 3, respectively. After the protective cover 8 and housing 7 are securely plugged in, the wires of the wire harnesses 9 are positioned within the corresponding comb-shaped slots 8-3 and then pass through them. The connecting wires are also led out through the routing notches 7-5 to the outside and ultimately electrically connected to the signal wires of the transformer C mounted on the base 10. The other end of the wire harness 9, which exits the housing 7, is directly electrically connected to the corresponding socket 2-1 via connector 1 9-1.

[0086] To ensure that the bracket 3 is stably fixed between the middle cover 11 and the base 10 after installation, a pressing structure consisting of an annular positioning plane 11-2 is also provided on the bottom surface of the middle cover 11 for pressing against the pin 3-8 and reducing the pressure on the base 10.

[0087] In order to ensure that the cover body 7 can be stably and reliably fixed on the base 10, a positioning cylinder 7-6 can be further provided on the outer side wall of the bottom of the cover body 7, that is, near the lower opening, for assistance. At the same time, the base 10 is provided with a corresponding positioning hole 10-3 at the corresponding position. When the cover body 7 is installed, the positioning cylinder 7-6 is also inserted into the positioning hole 10-3 of the base 10 ( Figure 20 E). It is best to use interference fit between the positioning cylinder 7-6 and the positioning hole 10-3.

[0088] In this embodiment, the first fully enclosed circuit board protection structure is horizontally positioned above the operating mechanism mounted on base 10. The second fully enclosed circuit board protection structure is positioned adjacent to the first fully enclosed circuit board protection structure and vertically inserted into base 10, with the side opening of cover 7 facing the side of bracket 3 not provided with inner edge 3-2. This allows the trip unit assembly within bracket 3 to be directly linked to the operating mechanism. Connector 2 6-2 is positioned opposite connector 1 2-1. The wire harness 9 connects the trip unit circuit board 2 to the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board) via a short, straight line, facilitating connection while avoiding excessive internal space occupation within circuit breaker 1.

[0089] After the above-mentioned protective structure and other structures inside the circuit breaker 1, such as the operating mechanism and the wiring mechanism, are installed, the middle cover 11 is first placed on the base 10. During this process, the outer edge is arranged outside the inner edge 3-2 to form a snap-fit ​​structure, leaving only an assembly gap A on the left and right (see Figure 19 ), leaving an assembly gap C (see Figure 20 ), the assembly gap is preferably controlled within 0.1~0.5mm to ensure the sealing of the first fully enclosed circuit board protection structure. Then, cover the mask 12 on the middle cover 11 so that the upper mask surface 12-3 contacts and fits with the outer edge, thereby completely sealing the upper part of the bracket 3, leaving only the assembly gaps B and D (see Figure 19 and Figure 20 ), and the indicator button 4 and the toggle handle passing through the accessory opening.

[0090] The structural status after installation is as follows Figure 19 、 20 As shown, the bracket 3, inner edge 3-2, outer edge, middle cover 11, and face shield 12 together form a closed cavity that completely encloses the trip unit circuit board 2. The cover 7, base 10, and protective cover 8 also form a completely enclosed cavity for the leakage signal detection and amplification circuit board 6 (i.e., the control circuit board). This closed cavity separates the circuit board from the rest of the space inside the circuit breaker 1, effectively preventing metal particles generated during the tripping process from adhering to the circuit board and potentially causing failure.

[0091] In the above structure, as a preferred embodiment, the cover 7 is sandwiched between or inserted between the terminal blocks, which can increase the optimized use of the internal space of the circuit breaker 1; and, further considering the closedness and installation convenience of the second fully enclosed circuit board protection structure, a corresponding rectangular groove 10-2 can be provided on the base 10 to cooperate with the bottom of the cover 7 to completely close the lower opening.

[0092] In each specific scheme of the above embodiment, interference fit can be adopted in structures such as between the pin and the slot, between the positioning boss 3-4 and the positioning opening 2-4, between the side boss 3-3 and the side wall of the connector 2-1, and between the wire and the routing gap 7-5. On the one hand, the corresponding structure can be fixed quickly and effectively to prevent loosening. On the other hand, it can further enhance the sealing of the protective structure from subtle details, thereby increasing the protection of the circuit board.

[0093] The circuit board protection structure of the molded case leakage circuit breaker 1 designed in the present invention is simple in structure, fully utilizing the existing components of the circuit breaker 1 to form an effective isolation space, thereby providing fully enclosed and effective protection for the circuit board. This invention can maximize the protection of electronic components, ensure the reliability of leakage products, and extend the product life.

Claims

1. A molded case circuit breaker, characterized in that: It includes a base, a mask, a middle cover, a trip unit component, a trip unit circuit board, a wire harness group, a leakage signal detection and amplification circuit board, a first fully enclosed circuit board protection structure, and a second fully enclosed circuit board protection structure. The first fully enclosed circuit board protection structure is as follows: it includes a bracket, the bottom of which is closed, and the upper part of which is provided with a mounting plane for mounting the release circuit board, and a certain height is provided between the upper part and the bottom; the mounting plane is provided with an inner peripheral edge on all sides, and one side of the inner peripheral edge is provided with a peripheral edge notch adapted to the width of the socket on the matching release circuit board; the outer peripheral edge is arranged on the inner side of the mask or the middle cover of the circuit breaker, and its shape and size are adapted to the mounting plane, the outer peripheral edge buckle is placed on the outer side of the inner peripheral edge, and its inner side wall is gap-matched with the outer side wall of the inner peripheral edge; the upper shield surface is arranged on the mask or the middle cover of the circuit breaker, and is arranged opposite to the mounting plane and contacts the outer peripheral edge to shield the upper part of the mounting plane; the upper shield surface is provided with an opening for the operating structure on the release circuit board to pass through, and the operating structure includes a button and a handle; the height of the outer peripheral edge is not less than the height of the inner peripheral edge; The second fully enclosed circuit board protection structure is as follows: it includes a cover body, which is enclosed on all sides in the longitudinal direction and has an L-shaped opening on the top. The L-shaped opening is formed by a main opening and a side opening that are vertically connected to each other. The L-shaped opening is provided with a fixing structure for fixing the leakage signal detection and amplification circuit board, and a mounting foot is provided near the bottom; a protective cover is configured to close the L-shaped opening on the cover body, including a main cover body corresponding to the main opening and a side cover body having comb-shaped grooves perpendicular to the side opening, and is further provided with a connection structure fixedly connected or detachably connected to the cover body; The release component is installed in the cavity inside the bracket of the first fully enclosed circuit board protection structure; the bottom of the bracket is installed on the base; the release circuit board is installed on the installation plane on the upper part of the bracket; the leakage signal detection and amplification circuit board is installed in the second fully enclosed circuit board protection structure, and the cover is installed on the base; the socket on the leakage signal detection and amplification circuit board is electrically connected to the socket on the release circuit board through a wire harness assembly; the outer edge is provided on the bottom surface of the middle cover, the upper shield surface is located on the bottom surface of the mask, and the middle cover and the mask are sequentially covered on the base; The first fully enclosed circuit board protection structure and the second fully enclosed circuit board protection structure are arranged adjacent to each other and the outlets of the first and second fully enclosed circuit board protection structures are arranged opposite to each other; A first fully enclosed circuit board protection structure is disposed across and above the operating mechanism mounted on the base; The second fully enclosed circuit board protection structure is sandwiched or inserted between the wiring boards.

2. The molded case circuit breaker according to claim 1, wherein: Inner edges are provided on three side surfaces around the mounting plane, and bosses are protruding from the edges of the inner edges adjacent to the sides without edges. The gap between the boss and the edge of the inner edges on the opposite side or between the boss and the boss on the edge of the inner edges on the opposite side forms an edge gap, and the edge gap is adapted to the width of the socket on the circuit board of the matching release.

3. The molded case circuit breaker according to claim 1, wherein: The gap between the inner edge and the outer edge is 0.1 to 0.5 mm.

4. The molded case circuit breaker according to claim 1, wherein: The middle part of the bracket is provided with a mounting groove for installing an indicator button, and the side wall of the bracket is provided with a mounting channel connected to the mounting groove. The opening of the mounting channel on the side wall of the bracket is closed by a baffle with a shape matching the opening.

5. The molded case circuit breaker according to claim 1, wherein: The bottom of the bracket is provided with pins for plugging with the base; or it also includes a pressing portion, which is configured on the middle cover or mask together with the outer edge and presses with the pins at the bottom of the bracket.

6. The molded case circuit breaker according to claim 1, wherein: The middle part of the bracket is provided with a cavity for installing the coil, the dynamic and static iron cores, and the transmission hook.

7. The molded case circuit breaker according to claim 1, wherein: The bottom of the cover is also provided with an opening, which is used to contact and cooperate with the bottom or side of the circuit breaker to be closed; and / or the fixing structure is a guide groove arranged on the inner side wall along the length direction of the cylindrical cover, and the number of the guide grooves is 2 and the 2 guide grooves are arranged opposite to each other.

8. The molded case circuit breaker according to claim 1, wherein: The L-shaped opening is further provided with a wiring notch, and the protective cover is provided with a shielding protrusion opposite to the wiring notch.

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