Passive energized fuse

Abstract

The utility model discloses a passive excitation fuse, including at least one main circuit and at least one branch circuit, at least one main circuit and at least one branch circuit are in parallel, and the cut -off action device is connected in series outside parallel position on at least one main circuit, and the variable resistance is connected in series on at least one main circuit and / or at least one branch circuit, and the tripping device is connected in series on at least one branch circuit. Utilize the characteristic that thermistor is sensitive to temperature, when temperature is abnormally high, capture this feature, make it through the resistance change response to the circuit, realize the commutation. Satisfy short -circuit protection under the low -times short -circuit current limit value fast response, improve the reliability of excitation fuse.

Description

Technical Field

[0001] This utility model belongs to the field of switch technology, specifically relating to a passive excitation fuse with active and passive protection functions. Background Technology

[0002] An excitation fuse works by detonating gunpowder to generate a high-pressure impact, which drives a mechanical device to cut off the circuit. It mainly consists of an excitation module, an execution module, and an arc-extinguishing device. The excitation module is used to generate a high-pressure impact by detonating an explosion after receiving an excitation signal. The excitation signal acquisition method is usually divided into external active excitation and internal passive excitation. The execution module drives a piston or knife switch with the thrust of the high-pressure impact to cut off the conductive parts of the main circuit and disconnect the circuit. The arc-extinguishing device uses a small arc-extinguishing fuse or grid to transfer and absorb the energy of the arc after the high-pressure current is cut off and a huge arc is generated.

[0003] Most existing energized fuses are active energized fuses. If the signal line of an active energized fuse fails, its function cannot be guaranteed. A small number of fuses combine active and passive energization, but their fusing time is difficult to control under low short-circuit current conditions, resulting in an inability to respond promptly.

[0004] Chinese patent CN201921427354.9 discloses a control circuit and vehicle for a fuse device. The fuse device includes: an arc-extinguishing fuse with an arc-extinguishing fuse wire, and an interrupter including a fuse wire and an actuating part capable of cutting off the fuse wire when energized. The fuse wire has a first lead and a second lead, one end of the arc-extinguishing fuse wire is connected to the first lead, and the other end of the arc-extinguishing fuse wire is connected to the second lead. The control circuit includes: a resistor connected in series with the fuse wire to form a first circuit; a normally open reed switch and a first power supply connected in series with the actuating part to form a second circuit; and a control coil connected in parallel across the resistor. When the current in the first circuit is greater than or equal to a threshold current, the control coil can control the normally open reed switch to close to conduct the second circuit, so that the actuating part cuts off the fuse wire. However, in this technical solution, the signal circuit requires an external power supply; the resistance value is manually adjusted, resulting in insufficient reliability and untimely response. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing excitation fuses, which require an external power supply, involve manual adjustment of the resistor value, suffer from insufficient reliability, and have slow response times. This invention provides a passive excitation fuse that utilizes the temperature-sensitive characteristic of a thermistor. When the temperature rises abnormally, this characteristic is detected, and the change in resistance is reflected in the circuit, achieving commutation. This meets the requirement of rapid response for short-circuit protection at low multiples of the short-circuit current limit, thus improving the reliability of the excitation fuse.

[0006] Technical solution

[0007] To achieve the above technical objectives, this utility model provides a passive excitation fuse, comprising at least one main circuit and at least one branch circuit, characterized in that: the at least one main circuit and at least one branch circuit are connected in parallel, a disconnection device is connected in series outside the parallel position on the at least one main circuit, a variable resistor is connected in series on the at least one main circuit and / or at least one branch circuit, and a tripping device is connected in series on the at least one branch circuit.

[0008] In one embodiment, the variable resistor is a thermistor.

[0009] In one embodiment, the resistance of the thermistor connected in series on the at least one main circuit increases with increasing temperature.

[0010] In one embodiment, the resistance of the thermistor connected in series on the at least one branch circuit decreases as the temperature increases.

[0011] In one embodiment, the tripping device on the at least one branch circuit is connected to a transmission device, which is linked to the ignition device on the cut-off action device via a lever mechanism.

[0012] In one embodiment, the transmission device includes an energy storage spring, one end of which is fixed and the other end is linked to a release element in the release device. During the movement of the energy storage spring, it can drive the lever mechanism to move, thereby impacting and igniting the ignition device.

[0013] In one embodiment, the two ends of the tripping device on the at least one branch circuit are directly connected to the ignition position on the cut-off action device to form a signal circuit, which can ignite the cut-off action device with an electrical signal.

[0014] In one embodiment, both ends of the tripping device are directly connected to at least one circuit of the cut-off action device equipped with a control switch.

[0015] In one embodiment, the tripping device is a thermal tripping device or a magnetic tripping device.

[0016] In one embodiment, a pair of tungsten electrodes is provided at the ignition position.

[0017] Beneficial effects

[0018] This utility model provides a passively activated fuse, comprising at least one main circuit and at least one branch circuit, wherein the at least one main circuit and at least one branch circuit are connected in parallel. A disconnecting device is connected in series outside the parallel connection position on the at least one main circuit. A variable resistor is connected in series on the at least one main circuit and / or at least one branch circuit, and a tripping device is connected in series on the at least one branch circuit. Utilizing the temperature-sensitive characteristic of a thermistor, when the temperature abnormally rises, this characteristic is detected and reflected in the circuit through a change in resistance, achieving commutation. This provides a fast response to short-circuit protection at low multiples of the short-circuit current lower limit, improving the reliability of the activated fuse. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Appendix Figure 1 This is a connection diagram of Embodiment 1 of this utility model;

[0021] Appendix Figure 2 This is a connection diagram of Embodiment 2 of this utility model. Detailed Implementation

[0022] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0027] Example

[0028] As attached Figure 1As shown, a passively activated fuse includes at least one main circuit 1 and at least one branch circuit 2, which are connected in parallel. A disconnecting device 3 is connected in series outside the parallel connection position on the at least one main circuit 1. A variable resistor 4 is connected in series on the at least one main circuit 1 and / or at least one branch circuit 2, and a tripping device 5 is connected in series on the at least one branch circuit 2. In this embodiment, it includes one main circuit 1 and one branch circuit 2, both of which are connected in series with a variable resistor 4. The branch circuit 2 is connected in series with a tripping device 5. Specifically, the variable resistor 4 is a thermistor, and the tripping device 5 is a thermal trip unit or a magnetic trip unit. In this embodiment, the tripping device 5 is a magnetic trip unit. The resistance of the thermistor 4a connected in series on the main circuit 1 increases with increasing temperature. The resistance of the thermistor 4b connected in series on the branch circuit 2 decreases with increasing temperature. When the rated current passes through, the resistance of the thermistor 4b on branch circuit 2 is greater than the resistance of the thermistor 4a on main circuit 1, and the current flows through main circuit 1. The current in branch circuit 2 is insufficient to activate the tripping device 5. When the current increases and the temperature rises, the resistance of the thermistor 4b on branch circuit 2 becomes less than the resistance of the thermistor 4a on main circuit 1, and the current through branch circuit 2 increases, activating the tripping device 5.

[0029] The tripping device 5 on one of the branch circuits 2 is connected to a transmission device 6, which is linked to the ignition device 8 on the cutting-off action device 3 via a lever mechanism 7. (See attached diagram) Figure 1 As shown, the transmission device 6 includes an energy storage spring 6a. One end of the energy storage spring 6a is fixed, and the other end is linked with the release element 5a in the release device 5. During the movement of the energy storage spring 6a, it can drive the lever mechanism 7 to move, thereby impacting and igniting the ignition device 8.

[0030] The working principle of this embodiment is as follows: Under normal operating conditions, current flows through the circuit and the magnetic trip unit does not operate; when a short-circuit current flows through, the current through the circuit where the magnetic trip unit is located increases, triggering the magnetic trip unit. The magnetic trip unit leaves the energy storage spring 6a, and the movement of the energy storage spring 6a drives the lever mechanism 7 to rotate. During the rotation of the lever mechanism 7, one end strikes the ignition device 8 to ignite the gas generator and pushes the piston rod in the cutting-off action device 3 to move and cut off the main circuit 1.

[0031] Example 2

[0032] As attached Figure 2As shown, in this embodiment, the two ends of the tripping device 5 on at least one branch circuit 2 are directly connected to the ignition position 9 on the cutting-off device 3 to form a signal circuit 10. The signal circuit 10 can electrically ignite the cutting-off device 3. At least one circuit in the circuit where the two ends of the tripping device 5 are directly connected to the cutting-off device 3 is equipped with a control switch 11. A tungsten electrode pair 12 is provided at the ignition position 9.

[0033] The working principle of this embodiment is as follows: Under normal operating conditions, current flows through the circuit and the magnetic trip unit does not operate; when a short-circuit current flows through, a voltage is generated at both ends of the magnetic trip unit. The change in voltage causes the tungsten electrode to generate an electric spark at 12, which ignites the gas generator and drives the piston rod in the cutting-off action device 3 to move and cut off the main circuit 1.

[0034] This utility model provides a passively activated fuse, comprising at least one main circuit 1 and at least one branch circuit 2, wherein the at least one main circuit 1 and at least one branch circuit 2 are connected in parallel. A disconnecting device 3 is connected in series outside the parallel connection position on the at least one main circuit 1. A variable resistor 4 is connected in series on the at least one main circuit 1 and / or at least one branch circuit 2, and a tripping device 5 is connected in series on the at least one branch circuit 2. Utilizing the temperature-sensitive characteristic of a thermistor, when the temperature abnormally rises, this characteristic is captured and reflected in the circuit through a change in resistance, achieving commutation. This provides a fast response to short-circuit protection at low multiples of the short-circuit current lower limit, improving the reliability of the activated fuse.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A passive energized fuse comprising at least one main circuit (1) and at least one branch circuit (2), characterized in that: The at least one main circuit (1) and at least one branch circuit (2) are connected in parallel. A disconnection device (3) is connected in series outside the parallel position on the at least one main circuit (1). A variable resistor (4) is connected in series on the at least one main circuit (1) and / or at least one branch circuit (2). A tripping device (5) is connected in series on the at least one branch circuit (2).

2. A passively activated fuse as described in claim 1, characterized in that: The variable resistor (4) is a thermistor.

3. A passively activated fuse as described in claim 2, characterized in that: The resistance of the thermistor 4a connected in series on at least one main circuit (1) increases with increasing temperature.

4. A passively activated fuse as described in claim 2, characterized in that: The resistance of the thermistor 2 (4b) connected in series on at least one branch circuit (2) decreases as the temperature increases.

5. A passively activated fuse as described in claim 1, characterized in that: The tripping device (5) on at least one branch circuit (2) is connected to a transmission device (6), and the transmission device (6) is linked to the ignition device (8) on the cutting-off action device (3) through a lever mechanism (7).

6. A passively activated fuse as described in claim 5, characterized in that: The transmission device (6) includes an energy storage spring (6a). One end of the energy storage spring (6a) is fixed, and the other end is linked with the release element (5a) in the release device (5). During the movement of the energy storage spring (6a), it can drive the lever mechanism (7) to move, thereby impacting and igniting the ignition device (8).

7. A passively activated fuse as described in claim 1, characterized in that: The two ends of the tripping device (5) on at least one branch circuit (2) are directly connected to the ignition position (9) on the cutting action device (3) to form a signal circuit (10), which can ignite the cutting action device (3) with an electrical signal.

8. A passively activated fuse as described in claim 7, characterized in that: The two ends of the tripping device (5) are directly connected to the circuit of the cutting-off action device (3), and at least one circuit is equipped with a control switch (11).

9. A passively activated fuse as described in claim 5 or 7, characterized in that: The tripping device (5) is a thermal tripping device or a magnetic tripping device.

10. A passively activated fuse as described in claim 7, characterized in that: A pair of tungsten electrodes (12) is provided at the ignition position (9).

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