A circuit protection switch

Abstract

The present application belongs to the field of electric power control and electric vehicle, and particularly relates to a circuit protection switch, comprising a shell, a smoke and fire device, a short circuit device and a plug-in part, the shell is provided with a static contact and a moving contact, when the moving contact combines with the static contact, the current is allowed to flow through the switch, when the moving contact separates from the static contact, the current is interrupted to flow through the switch; the smoke and fire device is arranged in the interior of the shell, when the current flowing through the switch is greater than a set value, the smoke and fire device receives an explosion signal through its pin, when the smoke and fire device explodes, the moving contact is caused to separate from the static contact; the short circuit device is arranged outside the shell, the pin of the smoke and fire device passes through the shell and is connected with the short circuit device, the short circuit device is used for short circuiting the pin of the smoke and fire device; when the plug-in part is inserted into the short circuit device, the plug-in part interrupts the short circuit of the smoke and fire device. The circuit protection switch is directly acted on the interior of the shell by the explosion device, the required position is more reliably blown open, and the circuit and personal safety are ensured.

Description

Technical Field

[0001] This invention belongs to the field of power control and electric vehicle technology, and particularly relates to a circuit protection switch. Background Technology

[0002] High-voltage DC circuit protection switches are commonly used in new energy industries such as electric vehicles, energy storage systems, and charging pile systems. With the rapid development of these industries, the performance requirements and quantity demands for circuit protection switches are constantly increasing. High-voltage DC circuit protection switches utilize sealing technology to reduce product size and cost. Existing circuit protection switches have an external explosive fuse. When an abnormality such as a large current occurs in the circuit, the fuse is detonated, acting on the moving contact of the circuit protection switch, causing the moving contact to separate from the stationary contact to disconnect the circuit and protect the entire circuit.

[0003] The explosive fuse is placed outside the sealed cavity of the circuit protection switch. When the explosive fuse activates, the sealed structure must first be breached to disconnect the circuit protection switch. According to the principle of action and reaction, the force of the explosive fuse breaching the sealed cavity is equal to the outward bursting force, thus requiring reinforcement of the external structure. However, because the external structure needs to be insulated from the high-voltage end, insulating materials such as plastic or ceramic shells are required. Plastic shells are not strong enough, and ceramic shells are not easily made into complex reinforced shapes. Therefore, there is a risk that the explosive fuse may shatter and scatter the surrounding fixed insulating material when it detonates, or even cause the entire system to explode. Furthermore, there is still a risk that the moving and stationary contacts inside the sealed cavity may not be triggered to separate. For example, in a fuse-integrated contactor disclosed in existing patent application CN202210250275.5, in order to ensure the sealing effect and connection strength of the ceramic cover, the existing ceramic cover uses ceramic brazing technology for sealing connection. The welding temperature of ceramic brazing is high, generally exceeding 800°C. If the explosive fuse is placed inside the sealed cavity of the circuit protection switch, the explosive fuse may be accidentally detonated during ceramic welding. In addition, it is difficult to lead the pin of the explosive fuse out of the sealed cavity. Therefore, placing the explosive fuse inside the sealed cavity of the switch presents a great technical challenge. Summary of the Invention

[0004] To address the problem that existing circuit protection switches have explosive fuses located outside the sealed cavity, making them highly susceptible to external destructive explosions during blasting, this invention provides a circuit protection switch.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a circuit protection switch, comprising,

[0006] The housing contains a stationary contact and a moving contact. When the moving contact is engaged with the stationary contact, current is allowed to flow through the switch. When the moving contact is disengaged from the stationary contact, current flow through the switch is interrupted.

[0007] A pyrotechnic device is installed inside a housing. When the current flowing through the switch is greater than a set value, the pyrotechnic device receives an ignition signal through its pins. When the pyrotechnic device explodes, the moving contact separates from the stationary contact.

[0008] A short-circuit device is disposed outside the housing, and the pins of the pyrotechnic device pass through the housing and are connected to the short-circuit device. The short-circuit device is used to short-circuit the pins of the pyrotechnic device.

[0009] And a connector that, when inserted into the short-circuit device, interrupts the short circuit of the pyrotechnic device.

[0010] Preferably, the pyrotechnic device includes an ignition tube, a PCB board, and explosive filler disposed within the ignition tube. The pyrotechnic device has external and internal pins. The PCB board is housed within a casing. The internal pins are electrically connected to both the ignition tube and the PCB board. The external pins are electrically connected to the PCB board and pass through the casing to connect to a short-circuit device. The external pins are first welded and sealed to the casing, then connected to the short-circuit device. The internal pins are connected to the PCB board. The PCB board is then placed inside the casing, and the external pins are connected to the PCB board again. The PCB board serves as a safe transfer mechanism, facilitating the safe exit of the pyrotechnic device's pins from the casing. Existing explosive filler contains carbon powder; if external conduction occurs, a circuit is formed, dissipating the electrical energy of conductive materials such as static electricity. This also ensures safety during the production and assembly of the switch under abnormal temperatures, such as elevated temperatures, effectively preventing accidental explosions of the pyrotechnic device due to static electricity or abnormal temperatures, and facilitating safety management during production and transportation.

[0011] Furthermore, the housing is provided with a cavity for mounting the PCB board and the ignition tube, and the PCB board is secured within the cavity. This ensures that the PCB board is securely mounted.

[0012] Furthermore, a piston structure is provided between the pyrotechnic device and the moving contact. When the pyrotechnic device explodes, it impacts the piston and the moving contact in sequence, causing the moving contact to separate from the stationary contact. The piston structure ensures both the separation of the moving contact from the stationary contact and prevents the moving contact from re-engaging after separation.

[0013] Preferably, the short-circuit device includes a short-circuit body and a metal spring. The metal spring is disposed within the short-circuit body, and the external pin contacts the metal spring for short-circuiting. When the connector is inserted into the short-circuit body, the connector disengages the metal spring from the external pin, thereby interrupting the short circuit of the pyrotechnic device. The short-circuit device has a simple and reliable structure, is ingeniously designed, and facilitates control over the contact and disconnection between the metal spring and the external pin.

[0014] Furthermore, the short-circuit body is a female connector, and the plug-in is a female connector that matches the short-circuit body. When the plug-in is inserted into the short-circuit body and interrupts the short circuit of the pyrotechnic device, the wires inside the plug-in are electrically connected to the external pins. The plug-in is a standard component. If the plug-in is installed in an electric vehicle, the short-circuit body is only connected to the plug-in when the switch needs to be installed. At this time, the plug-in interrupts the short circuit of the pyrotechnic device, and the wires inside the plug-in are electrically connected to the external pins. The switch is in normal operating condition and acts as a safety device in case of high current overload in the circuit.

[0015] Furthermore, the housing includes a ceramic cover and a base plate, which are sealed together by ceramic brazing. The external pins pass through the ceramic cover and connect to the short-circuit device. The external pins are also sealed to the ceramic cover by ceramic brazing. The stationary contacts are exposed outside the ceramic cover and are also sealed to the ceramic cover by ceramic brazing. The ceramic brazing provides excellent sealing and high connection strength. The cleverly designed short-circuit device allows the pyrotechnic device to be placed inside the housing. The explosive filler in the pyrotechnic device contains carbon powder. The short-circuit device conducts electricity to the outside of the pyrotechnic device, forming a circuit, which dissipates the electrical energy of conductive materials such as static electricity. This ensures safety during the production and assembly of the switch under abnormal temperatures, such as elevated temperatures, effectively preventing accidental explosions of the pyrotechnic device due to static electricity or abnormal temperatures, and facilitating safety control during production and transportation.

[0016] Furthermore, a protective outer shell is provided on the exterior of the ceramic cover, and a base portion is provided on the protective outer shell. The short-circuit body is disposed on the base portion, and a partition extends outward from the outer shell, the partition being located between the stationary contact and the short-circuit device. The protective outer shell effectively protects the switch, and the partition effectively isolates the high-voltage current of the stationary contact from the low-voltage current of the explosive device pin.

[0017] Furthermore, a mis-proof structure is provided between the short-circuit body and the base, which is used to indicate the installation position of the short-circuit body, facilitating the installation of the short-circuit device.

[0018] Beneficial effects:

[0019] 1. The circuit protection switch of the present invention, when the switch is connected to the circuit and the connector is inserted into the short-circuit body, the connector peels the metal spring from the pin of the pyrotechnic device to interrupt the short circuit of the pyrotechnic device. At the same time, the wire inside the connector is electrically connected to the external pin. At this time, the ignition tube is in normal working state. When the moving contact and the stationary contact are combined, the current flows through the switch. When the current flowing through the switch is greater than the set value, that is, when the circuit current is overloaded, the ignition tube receives the detonation current through the pin, the explosive filler explodes, causing the moving contact and the stationary contact to separate, so as to interrupt the current flow through the switch. Since the explosive device is set inside the shell, it acts directly on the inside of the shell. Only a small explosive force is needed to cause the moving contact and the stationary contact to separate, more reliably detonating the required position, ensuring that the external parts will not explode, ensuring the safety of the circuit and personnel, and saving the amount of explosive filler, greatly reducing the cost.

[0020] 2. In the circuit protection switch of the present invention, the pyrotechnic device is located inside the housing, and the pins of the pyrotechnic device are cleverly led out to the outside of the housing through a short-circuit device. Since the explosive filler of the pyrotechnic device contains carbon powder, the short-circuit device conducts the external circuit of the pyrotechnic device, thereby consuming the electrical energy of conductive materials such as static electricity, and ensuring the safety of the switch during production and assembly under abnormal temperatures, such as temperature rise. It effectively avoids accidental explosion of the pyrotechnic device due to static electricity, abnormal temperature, etc. Therefore, the pyrotechnic device can only be activated when the current flowing through the switch and the temperature reach a certain level. Under normal circumstances, the pyrotechnic device cannot be activated, which facilitates the safety control during the production and transportation of the switch. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a three-dimensional structural diagram of the circuit protection switch of the present invention;

[0023] Figure 2 This is a three-dimensional structural diagram of the circuit protection switch of the present invention from another angle, wherein the outer casing is not shown;

[0024] Figure 3 This is a cross-sectional schematic diagram of the circuit protection switch of the present invention;

[0025] Figure 4 yes Figure 3 A partially enlarged schematic diagram of part A, showing the metal spring contacting the external pin;

[0026] Figure 5 yes Figure 3A magnified view of part A, showing the metal spring strip separated from the external pin;

[0027] Figure 6 This is a three-dimensional structural schematic diagram of the short-circuit device of the circuit protection switch of the present invention;

[0028] Figure 7 This is a cross-sectional schematic diagram of the short-circuit device of the circuit protection switch of the present invention, wherein the metal spring is in contact with the external pin;

[0029] Figure 8 This is a cross-sectional schematic diagram of the short-circuit device of the circuit protection switch of the present invention, wherein the metal spring is in a state of external pin stripping.

[0030] In the diagram: 1. Housing, 11. Ceramic cover, 111. Cavity, 12. Base plate, 2. Stationary contact, 3. Moving contact, 4. Pyrotechnic device, 41. Pin, 411. External pin, 412. Internal pin, 42. Ignition tube, 43. PCB board, 5. Short-circuit device, 51. Short-circuit body, 52. Metal spring, 53. Error-proof structure, 6. Piston structure, 7. Protective shell, 71. Base, 72. Partition. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example

[0033] like Figures 1-8As shown, a circuit protection switch includes a housing 1, a pyrotechnic device 4, a short-circuit device 5, and a connector. The housing 1 contains a stationary contact 2 and a moving contact 3. When the moving contact 3 is engaged with the stationary contact 2, current flows through the switch; when the moving contact 3 is disengaged from the stationary contact 2, current flow is interrupted. The pyrotechnic device 4 is located inside the housing 1. When the current flowing through the switch exceeds a set value, the pyrotechnic device 4 receives an ignition signal through its pin 41. In this embodiment, the ignition signal is a current. When the pyrotechnic device 4 explodes, the moving contact 3 separates from the stationary contact 2. The short-circuit device 5 is located outside the housing 1. The pin 41 of the pyrotechnic device 4 passes through the housing 1 and connects to the short-circuit device 5. The short-circuit device 5 is used to short-circuit the pin 41 of the pyrotechnic device 4. When the connector is inserted into the short-circuit device 5, the connector interrupts the short circuit of the pyrotechnic device 4.

[0034] Specifically, in this embodiment, such as Figures 3-5 As shown, the pyrotechnic device 4 includes an ignition tube 42, a PCB board 43, and explosive filler disposed inside the ignition tube 42. The pins 41 of the pyrotechnic device 4 include external pins 411 and internal pins 412. The PCB board 43 is disposed inside the housing 1. The internal pins 412 are electrically connected to the ignition tube 42 and the PCB board 43 respectively. The external pins 411 are electrically connected to the PCB board 43 and pass through the housing 1 to connect to the short-circuit device 5. The housing 1 is provided with a cavity 111 for mounting the PCB board 43 and the ignition tube 42. The PCB board 43 is stuck in the cavity 111. A piston structure 6 is provided between the pyrotechnic device 4 and the moving contact 3. When the pyrotechnic device 4 explodes, it impacts the piston of the piston structure 6 and the moving contact 3 in sequence, causing the moving contact 3 to separate from the stationary contact 2.

[0035] Specifically, in this embodiment, such as Figures 1-8 As shown, the short-circuit device 5 includes a short-circuit body 51 and a metal spring 52. The metal spring 52 is disposed inside the short-circuit body 51. The external pin 411 contacts the metal spring 52 to short-circuit. When the connector is inserted into the short-circuit body 51, the connector peels the metal spring 52 from the external pin 411 to interrupt the short circuit of the pyrotechnic device 4. The short-circuit body 51 is a female connector, and the connector is a female connector that matches the short-circuit body 51. In this embodiment, the connector is a standard part and is not shown in the figure. When the connector is inserted into the short-circuit body 51 and interrupts the short circuit of the pyrotechnic device 4, the wire inside the connector is electrically connected to the external pin 411.

[0036] Specifically, in this embodiment, such as Figure 3As shown, the housing 1 includes a ceramic cover 11 and a base plate 12, which are sealed together by ceramic brazing. The external pin 411 passes through the ceramic cover 11 and is connected to the short-circuit device 5. The external pin 411 is also sealed to the ceramic cover 11 by ceramic brazing. The stationary contact 2 is exposed outside the ceramic cover 11 and is also sealed to the ceramic cover 11 by ceramic brazing. Figure 1 and Figure 3 As shown, a protective outer shell 7 is provided on the outside of the ceramic cover 11, and a base portion 71 is provided on the protective outer shell 7. The short-circuit body 51 is disposed on the base portion 71, and a partition 72 extends outward from the outer shell. The partition 72 is located between the stationary contact 2 and the short-circuit device 5; Figures 4-8 As shown, a fault-prevention structure 53 is provided between the short-circuit body 51 and the base 71. The fault-prevention structure 53 is used to indicate the installation position of the short-circuit body 51.

[0037] The lead-out process of pin 41 of the pyrotechnic device 4 of the circuit protection switch is as follows:

[0038] First, the external pin 411 is connected to the ceramic cover 11 by ceramic brazing and sealing. Then, the internal pin 412 is connected to the PCB board 43 by soldering. Because the soldering temperature is low, the ignition tube 42 will not be activated. Then, the PCB board 43 is placed in the cavity 111 of the housing 1. Then, the external pin 411 is connected to the PCB board 43 by soldering. Because the soldering temperature is low, the ignition tube 42 will not be activated.

[0039] Next, the outer shell is placed over the ceramic cover 11, and the short-circuit body 51 is installed on the base 71. At the same time, the external pin 411 is inserted into the short-circuit body 51 and short-circuits with the metal spring 52. At this time, the ceramic cover 11 and the base plate 12 can be ceramic brazed to seal the connection. Because the explosive filler contains carbon powder, the short-circuit device 5 forms a circuit by connecting the external of the pyrotechnic device 4, which can consume the electrical energy of conductive materials such as static electricity and ensure the safety of the production and assembly of the switch when the temperature is abnormal, such as when the temperature rises. It effectively avoids the accidental explosion of the pyrotechnic device 4 due to static electricity, abnormal temperature, etc. Therefore, the pyrotechnic device 4 can only be activated when the current and temperature flowing through the switch reach a certain level. The pyrotechnic device 4 cannot be activated normally, which facilitates the safety control during the production and transportation of the switch.

[0040] The working principle of the circuit protection switch is as follows:

[0041] When the switch is connected to the circuit and the connector is inserted into the short-circuit body 51, the connector peels the metal spring 52 from the external pin 411 to interrupt the short circuit of the pyrotechnic device 4. At the same time, the wire inside the connector is electrically connected to the external pin 411. At this time, the ignition tube 42 is in normal working condition. When the moving contact 3 and the stationary contact 2 are engaged, current flows through the switch. When the current flowing through the switch is greater than the set value, that is, when the circuit current is overloaded, the ignition tube 42 receives the detonation current through the pin 41. The explosive filler explodes and impacts the piston of the piston structure 6 and the moving contact 3 in sequence, causing the moving contact 3 to separate from the stationary contact 2, thereby interrupting the current flow through the switch. Since the explosive device is located inside the ceramic cover 11, it acts directly on the inside of the ceramic cover 11. Only a small explosive force is needed to separate the moving contact 3 from the stationary contact 2, more reliably detonating the required position, ensuring that external parts will not explode, ensuring circuit and personal safety, and saving the amount of explosive filler, greatly reducing costs.

[0042] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A circuit protection switch, characterized in that: include, The housing (1) is provided with a stationary contact (2) and a moving contact (3). When the moving contact (3) is engaged with the stationary contact (2), current is allowed to flow through the switch. When the moving contact (3) is disengaged from the stationary contact (2), the current flow through the switch is interrupted. The pyrotechnic device (4) is located inside the housing (1). When the current flowing through the switch is greater than the set value, the pyrotechnic device (4) receives an ignition signal through its pin (41). When the pyrotechnic device (4) explodes, the moving contact (3) separates from the stationary contact (2). A short-circuit device (5) is provided outside the housing (1). The pin (41) of the pyrotechnic device (4) passes through the housing (1) and is connected to the short-circuit device (5). The short-circuit device (5) is used to short-circuit the pin (41) of the pyrotechnic device (4). And a connector, which interrupts the short circuit of the pyrotechnic device (4) when the connector is inserted into the short-circuit device (5); The pyrotechnic device (4) includes an ignition tube (42), a PCB board (43), and explosive filler disposed in the ignition tube (42). The pins (41) of the pyrotechnic device (4) include external pins (411) and internal pins (412). The PCB board (43) is disposed in the housing (1). The internal pins (412) are electrically connected to the ignition tube (42) and the PCB board (43) respectively. The external pins (411) are electrically connected to the PCB board (43) and pass through the housing (1) to connect to the short-circuit device (5). The short-circuit device (5) includes a short-circuit body (51) and a metal spring (52). The metal spring (52) is disposed inside the short-circuit body (51). The external pin (411) contacts the metal spring (52) and short-circuits. When the connector is inserted into the short-circuit body (51), the connector peels the metal spring (52) from the external pin (411) to interrupt the short circuit of the pyrotechnic device (4). The housing (1) includes a ceramic cover (11) and a base plate (12), which are connected by ceramic brazing. The external pin (411) passes through the ceramic cover (11) and is connected to the short-circuit device (5). The external pin (411) is also connected to the ceramic cover (11) by ceramic brazing. The stationary contact (2) is exposed outside the ceramic cover (11), and the stationary contact (2) is also connected to the ceramic cover (11) by ceramic brazing.

2. The circuit protection switch according to claim 1, characterized in that: The housing (1) is provided with a cavity (111) for mounting the PCB board (43) and the ignition tube (42), and the PCB board (43) is stuck in the cavity (111).

3. The circuit protection switch according to claim 1, characterized in that: A piston structure (6) is provided between the pyrotechnic device (4) and the moving contact (3). When the pyrotechnic device (4) explodes, it impacts the piston and the moving contact (3) of the piston structure (6) in sequence, causing the moving contact (3) to separate from the stationary contact (2).

4. The circuit protection switch according to claim 1, characterized in that: The short-circuit body (51) is a female connector, and the plug is a female connector that matches the short-circuit body (51). When the plug is inserted into the short-circuit body (51) and interrupts the short circuit of the pyrotechnic device (4), the wire inside the plug is electrically connected to the external pin (411).

5. The circuit protection switch according to claim 1, characterized in that: The ceramic cover (11) is provided with a protective shell (7) on the outside. The protective shell (7) is provided with a base (71). The short-circuit body (51) is provided on the base (71). A partition (72) extends outward from the shell. The partition (72) is located between the stationary contact (2) and the short-circuit device (5).

6. The circuit protection switch according to claim 5, characterized in that: An error prevention structure (53) is provided between the short-circuit body (51) and the base (71), and the error prevention structure (53) is used to indicate the installation position of the short-circuit body (51).

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