JP7370072B2 - SPD with built-in separator and SPD unit with built-in separator - Google Patents

Description

The present invention relates to an SPD (Surge Protective Device) that safely releases lightning surges and prevents equipment from being destroyed by overvoltage and overcurrent, and particularly relates to an SPD that has a built-in overcurrent separator and thermal separator. .

Conventionally, SPDs (surge arresters) have been used to prevent breakdowns in electrical and electronic equipment caused by lightning. SPDs have built-in nonlinear elements for the purpose of limiting transient overvoltages such as lightning surges and shunting surge currents. This nonlinear element is, for example, a metal oxide varistor (MOV, hereinafter simply referred to as a varistor), such as a zinc oxide varistor. SPD has a high resistance equivalent to that of an insulator against normal power supply voltage, but instantly becomes low resistance against overvoltages such as lightning surges, allowing the surge current to flow to the ground side and suppressing the lightning surge voltage. suppress.

SPDs may deteriorate due to excessive lightning surges, etc., and as the deterioration progresses, 1. Overcurrent, 2. Phenomena such as overheating of the varistor occur. Patent Document 1 discloses a separator-built-in SPD that displays a failure and/or outputs an alarm contact when these phenomena are detected.

As shown in FIG. 9, the configuration of Patent Document 1 includes a current fuse 120 with a built-in striker 122 as an overcurrent separator, and serves as a thermal separator to separate the current fuse 120 from the terminals of the varistor 140 when the varistor 140 overheats. A conductor 130 is provided. In the current fuse 120, when the fuse body is blown by overcurrent, the striker 122 protrudes to the outside, and the first slider 123 struck by the striker 122 moves in a predetermined direction while resisting the restoring force of the spring. Further, the conductor 130 separates from the terminal of the varistor 140 when the varistor 140 overheats, and due to this separation, the second slider 131 is released from the conductor 130 and moves in a predetermined direction by the restoring force of the spring. The movement of the second slider 131 causes the first slider 123 to move in a predetermined direction. This movement of the first slider 123 turns on the microswitch 153 via the rotation lever 150.

Patent No. 6537089 (Figure 2)

In the configuration of Patent Document 1, when an overcurrent occurs or an overheat occurs in the varistor, the microswitch 153 is turned on, so that a failure indication and/or an alarm contact output can be performed.

However, the configuration of Patent Document 1 utilizes two sliders to detect the mechanical operation of the overcurrent separator and thermal separator and turn on the microswitch. Also, two springs are required to bias each slider. Furthermore, another component is required between the slider and the microswitch. For this reason, the number of parts of the SPD is increased, and high reliability cannot be obtained. Furthermore, the internal configuration is complicated, which makes it difficult to miniaturize the device. This is undesirable because it prevents the size of the SPD from falling within the so-called convention dimensions.

In view of the above-mentioned problems, the present invention provides a separator built-in SPD and a separator built-in SPD unit, which have an internal structure that is more reliable than conventional ones and can be easily miniaturized.

In one aspect of the present invention, the separator built-in SPD includes a first terminal, a second terminal, a varistor provided between the first terminal and the second terminal, and a varistor electrically connected in series with the varistor. The overcurrent separator includes an overcurrent separator connected to the varistor, a thermal separator electrically connected in series with the varistor, and a microswitch having an actuator and turned on when the actuator is pressed. is a current fuse in which a striker protrudes to the outside when the fuse body melts due to overcurrent, and the thermal separator is connected to a terminal of the varistor, and a conductor that separates from the terminal when the varistor overheats; The current fuse and the microswitch include a spring that moves the conductor by a restoring force so that the conductor pushes the actuator when the conductor is separated from the terminal, and the current fuse and the microswitch have a spring that causes the striker to protrude to the outside. The striker is arranged at a position where it directly pushes the actuator when the actuator is pressed.

According to this aspect, the SPD with a built-in separator includes, as an overcurrent separator, a current fuse whose striker protrudes to the outside when the fuse body is blown due to overcurrent. The SPD with built-in separator is used as a thermal separator to separate the conductor connected to the terminal of the varistor and the conductor by the restoring force so that when the conductor separates from the terminal of the varistor when the varistor overheats, the conductor pushes the actuator of the microswitch. It has a spring that moves the . The current fuse and the microswitch are arranged at a position where when the striker protrudes to the outside, it directly pushes the actuator of the microswitch. Accordingly, when an overcurrent occurs or an overheat occurs in the varistor, the microswitch is turned on, thereby making it possible to perform a failure indication and/or an alarm contact output. Furthermore, compared to the conventional configuration, two sliders are not used and only one spring is required, resulting in a simpler configuration with fewer parts. Therefore, it is possible to realize a separator built-in SPD that is highly reliable and easy to downsize.

In the above aspect, the conductor included in the thermal separator is a plate-shaped metal piece having a first part bent in an S-shape when viewed from the side, and a second part formed in a straight line. The metal piece has an end on the first portion side connected to a terminal of the current fuse, and one surface of the second portion is in contact with the actuator, and the other surface is in contact with the actuator. It may be biased by a spring.

According to this aspect, the thermal separator for detecting the occurrence of overheating of the varistor can be configured compactly.

In another aspect of the present invention, a separator built-in SPD unit constituting the SPD has the same configuration as the separator built-in SPD according to the above-described aspect.

According to the present invention, it is possible to provide a separator-built-in SPD and a separator-built-in SPD unit, which have an internal structure that is more reliable than conventional ones and can be easily miniaturized.

Internal configuration of separator built-in SPD according to embodiment of the present invention Basic circuit configuration of SPD with built-in separator shown in Figure 1 Explanatory diagram when the thermal separator operates in the configuration of Figure 1 Explanatory diagram when the overcurrent separator operates in the configuration of Figure 1 It is a configuration example of an SPD using a separator built-in SPD unit according to an embodiment, (a) is a front view, and (b) is a side view. (a) is an external view of the separator built-in SPD unit according to the embodiment, and (b) is a diagram showing the state in which the separator built-in SPD unit of (a) is incorporated into the SPD. External view of another example of the separator built-in SPD unit according to the embodiment Configuration example of a plug-in type SPD configured using the separator built-in SPD unit shown in Figure 7 Internal configuration of conventional SPD with built-in separator

Embodiments of the present invention will be described in detail below with reference to the drawings.

(Embodiment)
FIG. 1 is a diagram showing the internal configuration of a separator built-in SPD (Surge Protective Device) according to an embodiment of the present invention. The separator built-in SPD 1 in FIG. 1 has a metal oxide varistor 30 (hereinafter simply referred to as varistor 30) between the first terminal 11 and the second terminal 12 as an element for suppressing overvoltage caused by lightning surge. We are prepared. The varistor 30 is, for example, a zinc oxide varistor. The built-in separator type SPD 1 includes a current fuse 20 as an overcurrent separator and a thermal isolator 40. The separator built-in SPD 1 further includes a microswitch 50. By turning on the microswitch 50, a failure indication and/or alarm contact output is performed to the outside of the separator built-in SPD 1.

FIG. 2 is a diagram showing the basic configuration of the separator built-in SPD 1 shown in FIG. As shown in FIG. 2, the varistor 30 is provided between the first terminal 11 and the second terminal 12. Current fuse 20 is electrically connected in series with varistor 30. The thermal separator 40 is electrically connected in series with the varistor 30. When the current fuse 20 detects an overcurrent or when the thermal separator 40 detects overheating of the varistor 30, the microswitch 50 is turned on. That is, the separator built-in SPD 1 according to the present embodiment controls the microswitch 50 according to the mechanical operation of the current fuse 20 when an overcurrent occurs or the mechanical operation of the thermal isolator 40 when the varistor 30 overheats. is configured so that it is turned on.

Returning to FIG. 1, the current fuse 20 includes a fuse body 21 and terminals 21a and 21b. In the current fuse 20, a built-in striker (rod-shaped member) 22 protrudes to the outside when the fuse body 21 is blown out due to overcurrent. Here, the striker 22 protrudes upward in the drawing.

The thermal separator 40 has conductors 41 and 42 that electrically connect the terminal 31a of the varistor 30 and the terminal 21a of the current fuse 20. Note that the conductors 41 and 42 may be formed integrally. The conductor 41 is formed into a substantially linear plate shape, and one end is connected to the terminal 31a of the varistor 30 by solder. The conductor 42 is a plate-shaped metal piece having an S-shaped bent portion 42a and a linear portion 42b when viewed from the side (front view in the drawing). The end of the metal piece 42 on the side of the portion 42a is connected to the terminal 21a of the current fuse 20, and the end on the side of the portion 42b is connected to the other end of the conductor 41. The spring 43 has one end fixed in position, and the other end in contact with one surface of the portion 42b of the metal piece 42. The spring 43 biases the portion 42b of the metal piece 42 by its restoring force, that is, applies a force in the upward direction in the drawing. When the varistor 30 becomes overheated, the electrical connection (solder) between the conductor 41 and the terminal 31a of the varistor 30 melts, and the conductor 41 and the varistor 30 are separated. At this time, the conductor 41 moves upward in the drawing due to the restoring force of the spring 43 that urges the portion 42b of the metal piece 42.

The microswitch 50 is arranged above the current fuse 20 and the thermal isolator 40 in the drawing. In the microswitch 50, the actuator 51 is located on the side of the current fuse 20 and the thermal separator 40, and the terminal 52 for outputting an on/off signal is exposed from the separator built-in SPD 1. The actuator 51 of the microswitch 50 is in contact with the metal piece 42 of the thermal separator 40 . That is, one surface of the portion 42b of the metal piece 42 is in contact with the actuator 51, and the other surface is biased by the spring 43. When the conductor 41 and the terminal 31a of the varistor 30 are separated, the restoring force of the spring 43 moves the conductor 41 and the metal piece 42 upward in the drawing, thereby pushing the actuator 51 and turning on the microswitch 50. Further, when the striker 22 of the current fuse 20 protrudes to the outside, the actuator 51 is pushed and the microswitch 50 is turned on.

FIG. 3 shows a state in which the thermal separator 40 operates in the configuration of FIG. When the conductor 41 and the terminal 31a of the varistor 30 are separated due to overheating of the varistor 30, the conductor 41 and the metal piece 42 move upward in the drawing due to the restoring force of the spring 43, so that the surface of the portion 42b of the metal piece 42 The actuator 51 that was in contact with is pushed upward in the drawing, and the microswitch 50 is turned on.

FIG. 4 shows a state in which the overcurrent separator or current fuse 20 operates in the configuration of FIG. When the fuse body 21 is blown due to overcurrent, the striker 22 projects upward from the current fuse 20 in the drawing. The striker 22 directly pushes the actuator 51 of the microswitch 50 upward in the drawing, turning the microswitch 50 on.

As described above, according to the present embodiment, the separator built-in SPD 1 includes, as an overcurrent separator, the current fuse 20 in which the striker 22 protrudes to the outside when the fuse body 21 blows due to an overcurrent. Further, the separator built-in SPD 1 serves as a thermal separator 40, and includes conductors 41 and 42 connected to the terminal 31a of the varistor 30, and when the conductors 41 and 42 are separated from the terminal 31a of the varistor 30 when the varistor 30 overheats. It has a spring 43 that moves the conductors 41, 42 by restoring force so that the conductors 41, 42 press the switch 51 piece of the microswitch 50. The current fuse 20 and the microswitch 50 are arranged at a position where the striker 22 directly pushes the actuator 51 of the microswitch 50 when the striker 22 protrudes to the outside. Thereby, when an overcurrent occurs or when overheating occurs in the varistor 30, the microswitch 50 is turned on, so that a failure indication and/or an alarm contact output can be performed. Furthermore, compared to the conventional configuration, two sliders are not used and only one spring is required, resulting in a simpler configuration with fewer parts. Therefore, it is possible to realize a separator built-in SPD that is highly reliable and easy to downsize.

Further, the thermal separator 40 includes a plate-shaped metal piece 42 having a first portion 42a bent in an S-shape when viewed from the side, and a second portion 42b formed in a straight line. The end of the metal piece 42 on the first portion 42 a side is connected to the terminal 21 a of the current fuse 20 , and the second portion 42 b has one surface in contact with the actuator 51 and the other surface in contact with the spring 43 . energized. Thereby, the thermal separator 40 can be configured compactly.

Further, the upper surface of the rib 46 located below the conductor 41 of the thermal separator 40 is inclined. Specifically, the upper surface of the rib 46 gradually becomes higher as it goes from the right side to the left side in the drawing. As a result, when the conductor 41 is separated from the terminal 31a of the varistor 30, the conductor 41 moves upward due to the slope of the upper surface of the rib 46, thereby avoiding electrical contact between the conductor 41 and the varistor 30 again.

Further, the conductor 41 has a cutout portion 41a on the right side surface in the drawing. When the conductor 41 is separated from the terminal 31a of the varistor 30, the notch 41a engages the corner of the rib 46, thereby preventing electrical contact between the conductor 41 and the varistor 30 again.

<Configuration example using SPD unit with built-in separator>
The above-described separator built-in SPD may be used as one component of the SPD, that is, a separator built-in SPD unit. Hereinafter, a configuration example of an SPD configured using the separator built-in SPD unit according to the present embodiment will be described.

(Configuration example: built-in type)
FIG. 5 shows a configuration example of an SPD 200 configured using the separator built-in SPD unit according to the present embodiment, in which (a) is a front view and (b) is a side view. 6(a) is an external view of the separator built-in SPD unit 1, and FIG. 6(b) is an exploded view showing the state where the separator built-in SPD unit 1 is incorporated into the SPD 200.

In the SPD 200 shown in FIG. 5, a first case 201 and a second case 202 are connected by screws or other methods, and the separator built-in SPD unit 1 is installed therein. 203 is a screwless terminal block from which a signal is output when the SPD 200 deteriorates. A slider 204 is a mechanism for attaching the SPD 200 to a DIN rail used in a distribution board or the like.

The separator built-in SPD unit 1 shown in FIG. 6(a) has the same internal configuration as that in FIG. 1, and the terminal 52 from which the microswitch 50 outputs an on/off signal is exposed to the outside. In FIG. 6(b), three separator built-in SPD units 1 are installed inside the SPD 200. A flexible substrate (not shown) is provided inside the SPD 200 to connect the terminals 52 of each separator built-in SPD unit 1 to the screwless terminal block 203. When the actuator of the microswitch is pressed in any of the separator built-in SPD units 1, the switching of the signal output from the terminal 52 can be detected from the screwless terminal block 203.

Note that although FIG. 6(b) shows a state in which three separator-built-in SPD units 1 are installed inside the SPD 200, the number of separator-built-in SPD units 1 to be installed inside the SPD is 3. The number is not limited to 4, for example, but may be 4.

(Configuration example: Plug-in type)
FIG. 7 is an external view of another example of the separator built-in SPD unit according to the embodiment. The separator built-in SPD unit 301 shown in FIG. 7 basically has the same internal configuration as that in FIG. 1. However, the position of each terminal has been changed to make it compatible with the plug-in type. In FIG. 7, a terminal 311 corresponds to the first terminal 11 in FIG. 1, and a terminal 312 corresponds to the second terminal 12 in FIG. Further, the terminal 352 corresponds to the terminal 52 of the microswitch 50 in FIG. That is, in the separator built-in SPD unit 301 shown in FIG. 7, the terminals 311, 312, and 352 are all exposed to the outside from the same side surface (lower surface in the figure).

FIG. 8 is a diagram showing a plug-in type SPD 300 configured using the separator built-in SPD unit 301 shown in FIG. 7. As shown in FIG. 8, the terminal block 302 is configured such that a separator built-in SPD unit 301 shown in FIG. 7 can be attached thereto. In FIG. 8, three separator built-in SPD units 301 can be attached to the terminal block 302. The separator built-in SPD unit 301 is mounted with the surface on which the terminals 311, 312, and 352 are exposed facing the terminal block 302. 321 is a screwless terminal block from which a signal is output when the SPD 300 deteriorates. 322 is a slider that is a mechanism for attaching the SPD 300 to a DIN rail used for a distribution board or the like.

Inside the terminal block 302, a configuration is provided for connecting the terminals 352 of each attached separator built-in SPD unit 301 to the screwless terminal block 203. When the actuator of the microswitch is pressed in any of the separator built-in SPD units 301, switching of the signal output from the terminal 352 can be detected from the screwless terminal block 203.

In FIG. 8, three SPD units with built-in separators 301 can be attached to the terminal block 302, but the number of SPD units with built-in separators that can be attached to the terminal block is limited to three. For example, it may be four.

INDUSTRIAL APPLICABILITY The present invention is useful for improving the reliability and reducing the size of an SPD with a built-in separator used for lightning surge countermeasures.

1 SPD with built-in separator, SPD unit with built-in separator 11 First terminal 12 Second terminal 20 Current fuse (overcurrent separator)
21 Fuse body 22 Striker 30 Varistor 31a Varistor terminal 40 Thermal separator 41 Conductor 42 Metal piece (conductor)
42a First part 42b Second part 43 Spring 50 Micro switch 51 Actuator 200 SPD
300 SPD
301 SPD unit with built-in separator

Claims (4)

a first terminal and a second terminal;
a varistor provided between the first terminal and the second terminal;
an overcurrent separator electrically connected in series with the varistor;
a thermal separator electrically connected in series with the varistor;
and a microswitch that has an actuator and is turned on when the actuator is pressed,
The overcurrent separator is a current fuse whose striker protrudes to the outside when the fuse body melts due to overcurrent,
The thermal separator is connected to the terminals of the varistor, and includes a conductor that separates from the terminal when the varistor overheats, and a restoring force such that the conductor pushes the actuator when the conductor separates from the terminal. a spring that moves the conductor by
A separator-built-in SPD (Surge Protective Device), wherein the current fuse and the microswitch are arranged at a position where the striker directly pushes the actuator when the striker protrudes to the outside. The separator built-in SPD according to claim 1,
The conductor of the thermal separator is a metal plate having a first portion bent in an S-shape when viewed from the side, and a second portion formed into a straight line when viewed from the side. including a piece,
The end of the metal piece on the first part side is connected to the terminal of the current fuse, and the second part has one surface in contact with the actuator and the other surface in contact with the spring. This is an SPD with a built-in separator. An SPD unit with a built-in separator for configuring an SPD (Surge Protective Device),
a first terminal and a second terminal;
a varistor provided between the first terminal and the second terminal;
an overcurrent separator electrically connected in series with the varistor;
a thermal separator electrically connected in series with the varistor;
and a microswitch that has an actuator and is turned on when the actuator is pressed,
The overcurrent separator is a current fuse whose striker protrudes to the outside when the fuse body melts due to overcurrent,
The thermal separator is connected to the terminals of the varistor, and includes a conductor that separates from the terminal when the varistor overheats, and a restoring force such that the conductor pushes the actuator when the conductor separates from the terminal. a spring that moves the conductor by
The separator built-in SPD unit, wherein the current fuse and the microswitch are arranged at a position where the striker directly pushes the actuator when the striker protrudes to the outside. The separator built-in SPD unit according to claim 3,
The conductor of the thermal separator is a metal plate having a first portion bent in an S-shape when viewed from the side, and a second portion formed into a straight line when viewed from the side. including a piece,
The end of the metal piece on the first part side is connected to the terminal of the current fuse, and the second part has one surface in contact with the actuator and the other surface in contact with the spring. This is an SPD unit with a built-in separator.

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