JPH0453101A - Surge absorber with safety function - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a surge absorber with a security function for protecting equipment from surge voltages caused by lightning, etc. The present invention relates to a surge absorber with a security function that includes a surge absorbing element and an element that cuts off overcurrent to prevent a protected circuit from igniting.

2. Description of the Related Art Conventionally, this type of surge absorber has had a configuration as shown in FIG. 9 (for example, there is a surge absorber as shown in Japanese Patent Application Laid-Open No. 76551/1983).

In FIG. 9, 1 is a disk-shaped surge absorption element, 2
Reference numerals a and 2b are electrodes provided on both sides, and elastic lead wires 3 and 4 are connected to the electrode 2a with a low melting point solder 5, and a lead wire 6 is connected to the electrode 2b with a high melting point solder (not shown). It is connected. Additionally, lead wire 3.4.6
are connected and fixed to the grounding terminals 8, 9 and 10 of the support 7, respectively.

The operation of the surge absorber constructed as above will be explained below. This surge absorber is the 10th
Use as shown. First, the connection terminals 8 and 9 are connected to the power source 11, and the connection terminals 9 and 10 are connected to the circuit to be protected 12. Normally, there is a short circuit between connecting terminals 8 and 10.
．． The connection terminals 8 and 9 have a high resistance and are almost open, and when a surge voltage occurs on the power line, the surge absorber f1 has a low resistance and the connection terminal? -8 and 9 are close to a short circuit, and the surge current does not flow through the protected circuit 12, but instead flows between the connection terminals 8 and 9, absorbing the surge. In this circuit, when a continuous overvoltage is applied to the power supply line, a continuous overcurrent flows to the surge absorbing element 1, which generates heat and melts the low melting point solder 5.
As shown in the figure, the -F wires 3 and 4 having elasticity separate from the electrode 2a as indicated by the arrows, and the surge absorbing element 1 and the protected circuit 12 are cut off from the wait.

Problems to be Solved by the Invention In such a conventional configuration, when a continuous overcurrent flows through the surge absorbing element, the solder melts and separates from the electrode to which the wire was connected. , due to the large current, an arc discharge occurs between the 1st electrode and the distant 1st lead wire, and from the overcurrent, the energy absorption mechanism is completely cut off. There was a problem with the stimulant r igniting.

The present invention is intended to solve such problems, and aims to completely cut off the surge absorbing element No. 16 from continuous overcurrent.

Means for Solving the Problem In order to solve this problem, the present invention provides five surge absorbing elements, a low melting point metal element electrically connected in series with the surge absorbing element, and the surge absorber element. The surface of the low-melting point metal element is covered so as to be in close contact with the surface thereof, and the surface is contracted by the heat generated by the di-absorbing element A, causing the low-melting point metal element to melt, and the contact surface with the low-melting point metal element. It is constructed of a heat-shrinkable insulating tube having openings at two or several places.

Due to the configuration of each function, when a continuous overvoltage is applied to the surge absorber with a security function of the present invention, a continuous overcurrent flows to the surge absorbing element, and the surge absorbing element generates heat.
The heat melts the low-melting point metal element, and then the heat-shrinkable insulation (1-B) contracts, causing the low-melting-point metal element to melt, and the heat-shrinkable insulation (1-B) as an insulator melts. By intervening with the metal element, it is possible to completely cut off the RIS current 7 and prevent the surge absorbing element and the protected circuit from igniting.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing the structure of a surge absorber with a security function according to a first embodiment of the present invention, and FIG. 2 is a side view showing the structure of the surge absorber with a security function. In FIGS. 1 and 2, 21 is a surge absorber element using, for example, a varistor body, and includes electrodes 22 and 22a, and connecting wires 23 and 23a connected to the electrodes 22.22a.

Reference numeral 24 is an insulating material made of an inorganic non-metallic material such as glass, and coats the entire (or part) of the surface of the surge absorber element 21. 25 is a low melting point metal element such as a eutectic solder wire of tin or lead, and one end of this low melting point metal element 25 and a connecting wire 23 are connected by caulking 26 or the like, and the low melting point metal element The other end of the connecting lead wire 27 is connected to the other end of the connecting lead wire 27 by, for example, caulking 26a. Reference numeral 28 denotes a heat-shrinkable insulating tube having an opening 29 at one location so that its diameter shrinks to be smaller than the diameter of the surge absorber element 21 due to heat. Divided portions 28a and 28b, which are divided into two by the opening 29, cover and fix the low melting point metal element 25 so that the surface contacts the low melting point metal element 25.

In addition, the product of the present invention has connection lead wires 23, 23a to prevent the low melting point metal element 25 from scattering and to prevent moisture when melting.
, 27 is left and at least the area around the low melting point metal element 25 is often gauged with insulating resin or the like.
These are not shown in the figure.

The operation of the surge absorber with security function configured as described above will be explained below. Here, this surge absorber with safety function is used as shown in FIG. That is, in FIG. 3, 30 is a surge absorber with a safety function. 31 is the @ source or signal source, which is connected to the connecting leads 23a and 27 of the surge absorber with safety function 30, and 32 is the protected circuit, which is connected to the connecting leads 23 and 23a.
It is connected to the.

And normally the connection lead wire 23 and the connection lead vA27
There is a short circuit between the connecting lead wire 23a and the connecting lead wire 27, and there is a high resistance between the connecting lead wire 23a and the connecting lead wire 27, which is close to an open state. If a surge voltage occurs on the power line or signal line,
The surge absorbing element 21 that constitutes the present surge absorber 30 has a low resistance, and the connection lead wire 23a and the connection lead wire 27 are almost in a short circuit state, and the surge current is transferred to the protected circuit 3.
2, but instead flows between the connection lead wire 23a and the connection lead wire 27, and the surge is absorbed.

In this circuit, when continuous overvoltage is applied to the power supply line or signal line due to contact between high-voltage lines, etc., continuous overcurrent flows to the surge absorption element 21, which gradually generates heat and conducts heat. This heat is transferred to the low melting point metal element 25 by the insulator 24, such as a glass having good properties, and the low melting point metal element 25 is melted. At the same time, either or both of the participle portions 28a and 28b of the heat-shrinkable insulating tube 28 shrinks in the radial direction, and the molten low-melting metal element 25 is transferred to the divided portion 2 of the heat-shrinkable insulating tube 28.
The low melting point metal element 25 is pushed out by the contraction force in the radial direction of either or both of the heat-shrinkable insulating tubes 28, and the separated into

In other words, the overcurrent flowing through the surge absorbing element 2I is
Divided portion 28a of heat-shrinkable insulation tube 28 which is an insulator
, 28b or both low melting point metal elements 25
After the low melting point metal element 25 has been separated, the arc is completely shut off without any arc discharge occurring. Therefore, the surge absorbing element 21 stops generating heat, and ignition can be prevented.

As described above, the surge absorber with security function of this embodiment has the effect of preventing the surge absorbing element 21 and the protected circuit 32 from igniting due to continuous overvoltage.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 is a front view showing the structure of a surge absorber with a security function according to a second embodiment of the present invention, and FIG. 5 is a side view showing the structure of the same surge absorber with a security function.

The difference from the first embodiment is that the heat-shrinkable insulating tube has two openings instead of one. 4 and 5, 33 is a surge absorption element using, for example, a varistor body, and electrodes 34 and 34a
, connection leads $1135 and 35a.

Reference numeral 36 is an insulating material made of an inorganic non-metallic material such as glass, which coats the entire (or part of) the surface of the surge absorbing element 33. Reference numeral 37 denotes a low melting point metal element such as a eutectic solder wire of tin or lead, and one end of this low melting point metal element 37 and the connection lead wire 35 are connected by, for example, caulking 38. The end and the connecting lead wire 39 are connected by, for example, caulking 38a. Reference numeral 40 denotes a heat-shrinkable insulating tube having two openings 4L and 41a so that its diameter shrinks to be smaller than the diameter of the surge absorbing element 33 due to heat, and an insulator 36 coating the surface of the surge absorbing element 33.
The divided portion 40 is divided into three parts by the openings 41 and 41a such that the low melting point metal element 37 is in contact with the surface of the divided portion 40.
a, 40b and 40c cover and fix the low melting point metal element 33 so that they are in contact with it.

The function of the surge absorber with security function configured in this way is similar to that of the first embodiment, but compared to the first embodiment, the heat-shrinkable insulating tube has two openings. Therefore, the number of fusing points of the low melting point metal element becomes three, the insulation distance becomes longer, and continuous overcurrent can be interrupted more reliably. Further, it is possible to reduce the variation in time until melting occurs.

Next, a third embodiment of the present invention will be explained with reference to FIGS. 6 and 7. FIG. 6 is a front view showing the structure of a surge absorber with a security function according to the second embodiment of the present invention, and FIG. 7 is a side view showing the structure of the surge absorber with the security function. It is a diagram.

Here, the first. The difference from the second embodiment is that a discharge gap 1 is used as the surge absorbing element 2 instead of a varistor body. In Figures 6 and 7, 4
Reference numeral 2 denotes a power absorption element using, for example, a discharge gap, and is provided with four connection lead wires 43 and 43a. 44 is a low melting point metal element such as a eutectic solder wire of tin or lead, and one end of this low melting point metal element 44 is connected to a connecting lead WA46 by, for example, caulking 45, and the other end of the low melting point metal element 44 and the connection lead 143a are connected to each other by, for example, caulking 45a. 47
is a heat-receiving insulation plate having two openings 48 and 48a whose diameter shrinks to be smaller than the diameter of the surge absorbing element 42 due to heat; The divided portion 5N is divided into three parts by the openings 48 and 4.8a so that the metal element 44 is in contact with the divided part 5N? a
, 47b, 4, and 41c are the low melting point metal elements 4
They are covered and fixed so that they are in contact with 4.

The operation of the surge absorber with security function configured as described in 1-1 below will be described above. Security IN
! The power container is used as shown in Figure 8. 49 is a body security function-equipped absorber.

50 is a power supply or signal source, and 4 with this safety function is connected to the 4 absorbers with 4 connecting lead wires 43.46! : "Connected, 51 is connected in the protected circuit, connected to the lead wire 43.43a. Then, normally connected, there is a short circuit between the lead wire 43a and the connecting lead 146, and the connecting lead wire 43 and the connecting lead wire 46 is in a state of high resistance and close to open circuit.If a surge voltage occurs on the in-line or signal line, the surge absorbing element 42 that constitutes this surge absorber 49 has a low resistance, The connection lead wire 43 and the connection lead wire 46 are almost in a short-circuit state, and the surge current does not flow through the protected circuit 51 but instead flows between the connection saw 1' wire 46 and the connection lead wire 43, and the surge is absorbed. Ru.

When a continuous overvoltage is applied to the power supply line or signal line in this @ path due to contact between high voltage lines, the continuous overvoltage flows to the surge absorber f'42, and the surge absorbing element 42 gradually generates heat, and the low melting point metal element 44 melts. At the same time, the divided portion 4 of the heat-shrinkable insulating tube 47
Any or all of 7a, 47b, and 47c contract in the radial direction, and the molten low-melting metal element 44 becomes the divided portion 4.7a, 47b+47 of the heat-shrinkable insulating tube 47.
The low melting point metal element 44 is pushed out by the contraction force in the radial direction of any or all of the heat-shrinkable parts 47a, 47b, 4
7. Separated by sandwiching any or all of c. That is, the overcurrent flowing through the surge absorbing element 42 is absorbed by the divided portion 4 of the heat-shrinkable insulating tube 470, which is an insulator.
After separation of the low melting point metal element 44 by intervention of any or all of the low melting point metal elements 44 of ?7a, 47b, 47c? - It is completely shut off without any discharge.

Therefore, the surge absorbing element 42 stops generating heat, and ignition can be prevented.

As described above, the surge absorber with a safety function of the present invention has the effect of preventing the surge absorbing element f42 and the protected circuit 51 from igniting due to continuous overvoltage.

In the embodiment of the present invention, an inorganic non-metallic material is used as the insulator coating the surface of the surge absorbing element.
Although glass was used as the insulator, it is not limited to this, and eutectic solder wire of tin and lead was used as the low melting point metal element, and r is the low melting point metal element. Although the heat-shrinkable insulating tube is provided with apertures at one or two places, the number of apertures is not limited.

Effects of the Invention As described above, according to the present invention, a surge absorbing element, a low melting point metal element electrically connected in series with the surge absorbing element, and a surface of the surge absorbing element described in 1- Cover the low melting point metal elements so that they are in close contact with each other, contract by the heat generated by the surge absorbing element, fuse the low melting point metal elements, and cover a portion or part of the contact surface with the low melting point metal elements. By being configured with a heat-shrinkable insulating tube having openings at certain locations, it is possible to prevent the surge absorbing element and the protected circuit from igniting due to continuous overvoltage.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the structure of the first embodiment of the surge absorber with security function according to the present invention, FIG. 2 is a side view showing the structure of the same embodiment, and FIG. 3 is the use of the same embodiment. A circuit diagram showing an example, FIG. 4 is a front view showing a structure according to a second embodiment of the present invention, FIG. 5 is a side view showing a structure according to the same embodiment, and FIG. 6 is a third embodiment of the present invention. FIG. 7 is a front view showing the structure according to the example, FIG. 7 is a side view showing the structure according to the same example, FIG. 8 is a circuit diagram showing an example of use according to the example, and FIG. 9 is a structure of a conventional surge absorber. A front view, FIG. 10 is a circuit diagram showing an example of use of the surge absorber, and FIG. 11 is a front view showing the state of the surge absorber in operation. 2L 33.42...Surge absorption element, 25.
37 44...Low melting point metal element, 2B, 40
．． 47...Heat-shrinkable insulating tube, 29.41.
41. a, 48.48a...Opening part. Name of agent: Patent attorney Shigetaka Awano Haka 1 person 2/v
- Ji W and Harshun 7 b Statue - Cruelty, sac! SpringFigure 3Figure 4Figure 4Figure 10FigureFigure ■

Claims (3)

[Claims] (1) a surge absorbing element; a low melting point metal element electrically connected in series with the surge absorbing element; A safety device consisting of a heat-shrinkable insulating tube that shrinks due to the heat generated by the surge absorbing element, fuses the low-melting point metal element, and has openings in a portion or several places of the contact surface with the low-melting point metal element. Surge absorber with security function. (2) The surge absorber with a security function according to claim 1, wherein the surge absorbing element is a varistor body whose surface is partially or entirely coated with an insulating material. (3) As an insulator coating the varistor body,
The surge absorber with a security function according to claim 2, which is made of an inorganic nonmetallic material.