JPH0650955Y2 - Surge absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a discharge type surge absorbing element that absorbs a surge such as induced lightning applied to a telephone circuit or the like by a discharge phenomenon of a discharge gap enclosed in an airtight container. In particular, the present invention relates to a surge absorber in which overcurrent interruption means is connected in series, and more particularly, to a surge absorber in which safety is further improved by preventing continuation of arc discharge in a discharge type surge absorbing element.

[Prior Art] A type of discharge type surge absorbing element 2, which is widely known as a gas arrester, has lead wires 5, 5 connected to a pair of discharge electrodes 4, 4 as shown in FIG. The discharge gaps 4 are formed between the discharge electrodes 4 and 4 and are sealed together with the discharge gas in a hermetic container 7 made of glass, and the lead wires 5 and 5 are placed outside the hermetic container 7. It has the structure derived to.

The discharge type surge absorbing element is used by being connected to a telephone line or the like, and when a surge such as an induced lightning is applied to this, a discharge is generated in the discharge gap to absorb the surge,
It has a function of preventing surge from entering a telephone or the like. Since the surge absorption is due to the arc discharge in the discharge gap, it is possible to absorb a considerably large surge.

[Problems to be solved by the invention] By the way, telephones are overvoltage tested by safety standards such as CSA and UL.

This overvoltage test assumes a case where a power line comes into contact with a telephone line, and applies an AC voltage exceeding the rated voltage (DC discharge start voltage) of the discharge type surge absorbing element. Therefore, when the above-mentioned overvoltage test is performed, the applied AC voltage causes the arc discharge between the discharge electrodes to be in a continuous state, and the discharge electrodes are melted and short-circuited. Further, the heat also melts the airtight container and entangles with the discharge electrode, and eventually the circuit board on which the discharge type surge absorbing element is mounted is burned out. This causes the overvoltage test to fail. In addition, if the above-mentioned phenomenon occurs during use, a fire may occur.

The present invention has been devised in view of the above-mentioned point, and even when the arc discharge is in a continuous state at the time of an overvoltage test or a line accident according to the safety standard, the arc discharge occurs before the discharge electrode is melted and short-circuited. The purpose is to prevent a burnout accident by shutting off the power and to realize a highly safe surge absorber that complies with safety standards.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the surge absorber of the present invention comprises:
A strip-shaped heating resistor formed by bending in a meandering shape formed on one surface of the insulating substrate, and the insulating substrate that is crushed by thermal shock of the strip-shaped heating resistor generated by continuous overcurrent conduction. A discharge which is connected in series with the overcurrent interrupting means consisting of a thin portion that crosses the strip-shaped heating resistor formed on the other surface and crosses the strip-shaped heating resistor, and is arranged to face each other across a discharge gap. It is characterized by comprising a discharge type surge absorbing element in which electrodes are hermetically sealed together with a discharge gas.

Also, a belt-shaped heating resistor bent in a meandering shape, which is formed by alternately connecting vertically and horizontally a resistor element and a good electrical conductor on one surface of an insulating substrate, and generated by continuous overcurrent And a strip-shaped heating resistor, which is composed of a thin portion that crosses the strip-shaped heating resistor formed in a groove shape on the other surface of the insulating substrate and crushes due to the thermal shock of the strip-shaped heating resistor. It is characterized in that it comprises a discharge type surge absorbing element which is connected in series with and is hermetically sealed together with a discharge gas with discharge electrodes which are opposed to each other with a discharge gap.

[Operation] The surge absorber of the present invention comprises a strip-shaped heating resistor which is bent in a meandering shape and has a bent portion adhered to one surface of an insulating substrate, and the strip-shaped heating resistor. Overcurrent interrupting means consisting of a thin portion crossing the strip-shaped heating resistor formed in the other surface of the insulating substrate which is crushed by thermal shock, and a discharge arranged opposite to each other across a discharge gap. Since the discharge type surge absorbing element in which the electrodes are hermetically sealed together with the discharge gas is connected in series, an arc discharge is generated in the discharge type surge absorbing element to increase the amount of current, and when this overcurrent becomes a continuous state, The band-shaped heat generating resistor rapidly generates heat and gives a thermal shock to the insulating substrate. Then, due to the thermal shock to the insulating substrate, the insulating substrate is ruptured in the thin portion, and the band-shaped heating resistor that is a current path is cut,
Cut off the arc discharge.

In addition, the overcurrent cutoff means is formed by continuously connecting a resistor element and a good electric conductor alternately on one surface of the insulating substrate in a vertical and horizontal direction and forming a meandering band-shaped heat generating resistor. The strip-shaped heating resistor is ruptured by thermal shock of the strip-shaped heating resistor generated by the passing of an electric current, and the strip-shaped heating resistor is formed on the other surface of the insulating substrate in a groove shape and crosses the strip-shaped heating resistor. Since the body and the discharge-type surge absorbing element in which the discharge electrodes facing each other across the discharge gap are hermetically sealed together with the discharge gas are connected in series, the current easily concentrates when a high voltage such as a surge is applied. Since the bent portion is not a resistor but an electrically good conductor, there is no possibility of burning the bent portion.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a surge absorber according to an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram showing a surge absorber of the present invention, and FIG. 3 is a schematic side view of an embodiment of the present invention. FIG. 4 is a schematic sectional view of a discharge type surge absorber used in an embodiment of the present invention, FIG. 5 is a schematic rear view of an embodiment of the present invention, and FIG.
FIG. 7 is a schematic rear view of another embodiment of the present invention, and FIG. 7 is a schematic cross-sectional view of an overcurrent interruption means of the present invention. In the figure, reference numeral 1 denotes a surge absorber, which is configured by connecting a discharge type surge absorbing element 2 on an overcurrent interruption means 3 in series.

As shown in FIG. 4, the discharge type surge absorbing element 2 has a surface made of nickel or the like having a good discharge characteristic of BaO or BaO.
.Connecting lead wires 5 and 5 made of Dumet wire to the base ends of the pair of rod-shaped discharge electrodes 4 and 4 formed by covering with an emitter material such as Al ₂ O ₃ and facing them in parallel with each other. To form a discharge gap 6 between the discharge electrodes 4 and 4, and further to dispose both ends of the glass tube together with a discharge gas mainly containing an inert gas such as a rare gas such as Ne, Ar or He or a nitrogen gas. The lead wires 5 and 5 are led out of the airtight container 7 by enclosing it in an airtight container 7 formed by sealing.

The overcurrent interruption means 3 is made of ceramics such as alumina, forsterite, steatite, etc. and has a thickness of 0.5.
A strip-shaped heating resistor 9 made of ruthenium-based paste or the like is adhered and formed in a meandering shape having a plurality of bent portions on one surface of an insulating substrate 8 of up to 1.5 mm. It occurs when lead-out electrodes 10a and 10b made of a good electrical conductor such as Ag / Pd paste are adhered to both end portions, and a continuous overcurrent is applied to the substantially central portion of the other surface of the insulating substrate 8. A groove-shaped thin portion 11 that ruptures the insulating substrate 8 in the left-right direction by the thermal shock of the strip heating resistor 9 is formed across the strip heating resistor 9.

The strip heating resistor 9 is bent in a meandering manner on the insulating substrate 8 so that the resistance value between both ends of the strip heating resistor 9 is within the range of 1Ω to 300Ω in accordance with the test conditions in various safety standards. By doing so, the length is appropriately set. Also,
As shown in FIG. 5, when the strip-shaped heating resistor 9 is adhered and formed, the thickness of the strip-shaped heating resistor 9 is 10 μm to 25 μm.
It is preferable that the width is about 0.5 mm to 10 mm.

Then, the insulating substrate 8 is penetrated through the extraction electrode 10a to fix the external terminal 12a by soldering or the like, and one of the lead wires 5 and 5 of the discharge type surge absorbing element 2 is penetrated through the insulating substrate 8. Then, the lead-out electrode 10b is similarly fixed to the lead-out electrode 10b by soldering or the like, and the strip heating resistor 9 and the discharge type surge absorbing element 2 are connected in series. Further, the other of the lead wires 5 and 5 is fixed to the other surface of the insulating substrate 8 and is connected and led out to the external terminal 12b.

FIG. 6 shows another embodiment of the present invention, in which an insulating substrate 8
Three elongated resistor elements 9a, 9b, 9c are formed on one surface in parallel with each other in the left-right direction, and the resistor elements 9a, 9b
At the right end of the resistor element and the left end of the resistor elements 9b and 9c, respectively.
Electrically good conductors 13 and 13 made of a paste or the like are vertically formed to adhere to the resistor elements 9a, 9b and 9c and electrically good conductors 13 and 13.
And are alternately connected in series to form a meandering belt-shaped heating resistor 9. With the band-shaped heat generating resistor 9 having such a configuration, the bent portion where the current is likely to concentrate when a high voltage such as a surge is applied is not a resistor but an electrically good conductor. There is no risk of burning.

Further, as shown in FIG. 7, the junction between the strip heating resistor 9 and the extraction electrodes 10a and 10b, and the junction between the resistor elements 9a to 9c and the good electrical conductor 13 are as shown in FIG.
Are divided into lower layers 10a ₁ and 10b ₁ and upper layers 10a ₂ and 10b ₂ , respectively, and the electrically good conductor 13 is divided into lower layers 13 ₁ and 13 ₂ and these lower layers 10a ₁ , 10b ₁ and 13 ₁ The resistor 9 is interposed between the upper layers 10a ₂ , 10b ₂ and 13 ₂ . Further, the extraction electrodes 10a, 10b and the electrically good conductor 13 have a thickness of 10 μm.
It is preferable that the thickness is m to 25 μm and the width is 0.5 mm to 10 mm.

It should be noted that the strip-shaped heat generating resistor 9 formed on the insulating substrate 8 by adhesion.
Is coated with lead-free glass such as borosilicate glass or bismuth glass to a thickness of 10 μm to 100 μm,
Not only does it serve as an insulating film, but it is possible to prevent the occurrence of creeping discharge on the surface of the resistor 9.

However, if the surge absorber 1 of the present invention is connected to a telephone line or the like, when a surge such as inductive lightning is applied, a discharge is generated in the discharge gap 6 in the discharge type surge absorbing element 2 to generate the surge. However, since the surge current application means 3 has a short surge application time and the strip heating resistor 9 does not generate much heat, the thin portion 11 is not subjected to thermal shock.

In addition, when an AC voltage exceeding the rated voltage of the discharge type surge absorbing element 2 is applied to a telephone line for a long time, the arc discharge between the discharge electrodes 4 and 4 is maintained in the discharge type surge absorbing element 2. However, the strip-shaped heat generating resistor 9 of the overcurrent interruption means 3 rapidly generates heat to apply a thermal shock to the insulating substrate 8, and the brittle thin portion 11 of the insulating substrate 8 is crushed. As a result, the strip-shaped heating resistor 9, which is a current path formed on the insulating substrate 8, is cut off, and the overcurrent interrupting means 3 interrupts the excessive voltage that sustains the arc discharge.

[Advantages of the Invention] As described in detail above, according to the surge absorber of the present invention, a strip-shaped heating resistor formed by bending in a meandering shape on one surface of an insulating substrate and a continuous overcurrent. Means for overcurrent shutoff comprising a groove-like thin portion formed on the other surface of the insulating substrate and crushed by thermal shock of the strip-shaped heating resistor generated by energization of the strip-shaped heating resistor. And a discharge type surge absorbing element in which discharge electrodes facing each other across a discharge gap are hermetically sealed together with a discharge gas, are connected in series. Even when the arc discharge in (2) is in a continuous state, the thermal shock from the strip-shaped heating resistor is applied to the thin portion of the insulating substrate, and the thin portion is shredded. As a result, the strip-shaped heating resistor, which is the path through which the current flows, can be cut off, and the arc discharge in the discharge-type surge absorption element can be cut off, which in turn prevents burnout accidents and is highly safe in conformity with safety standards. It becomes possible to realize a surge absorber.

In addition, the overcurrent cutoff means is formed by continuously connecting a resistor element and a good electric conductor alternately on one surface of the insulating substrate in a vertical and horizontal direction and forming a meandering band-shaped heat generating resistor. The strip-shaped heating resistor is crushed by the thermal shock of the strip-shaped heating resistor generated by the passage of an electric current, and the strip-shaped heating resistor is formed on the other surface of the insulating substrate in a groove shape. Since the resistor and the discharge type surge absorbing element in which the discharge electrodes facing each other across the discharge gap are hermetically sealed together with the discharge gas are connected in series, the current concentrates when a high voltage such as a surge is applied. Since the easily bent portion is not a resistor but an electrically good conductor, the danger that the bent portion is burned can be eliminated, and a surge absorber with higher safety can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram showing a surge absorber of the present invention, FIG. 3 is a schematic side view showing an embodiment of the present invention, and FIG. FIG. 5 is a schematic sectional view of a discharge type surge absorbing element used in one embodiment of the present invention, FIG. 5 is a schematic rear view showing one embodiment of the present invention, and FIG. 6 is another embodiment of the present invention. FIG. 7 is a schematic rear view, and FIG. 7 is a schematic cross-sectional view of an essential part of the overcurrent interruption means in the present invention. 1 ... Surge absorber, 2 ... Discharge type surge absorber, 3
...... Overcurrent interruption means 4 ...... Discharge electrode, 6 ...... Discharge gap, 8 ...... Insulation substrate, 9
...... Strip-shaped heating resistor 11 ...... Thin portion, 13 ...... Good electrical conductor

Claims (2)

[Scope of utility model registration request] 1. A strip-shaped heating resistor formed on one surface of an insulating substrate and bent in a meandering shape, and crushed by thermal shock of the strip-shaped heating resistor generated by continuous energization of overcurrent. Which is formed on the other surface of the insulating substrate in the form of a groove and has a thin portion that traverses the strip-shaped heating resistor, and an overcurrent interrupting means, which is connected in series with the strip-shaped heating resistor and is separated by a discharge gap. And a discharge-type surge absorbing element in which discharge electrodes arranged to face each other are hermetically sealed together with a discharge gas. 2. A belt-shaped heating resistor bent in a meandering shape, which is formed by alternately connecting vertically and horizontally a resistor element and a good electrical conductor on one surface of an insulating substrate, and a continuous overcurrent An overcurrent cutoff means consisting of a thin portion formed in a groove shape on the other surface of the insulating substrate and crushed by the thermal shock of the strip-shaped heating resistor generated by energization, and the strip-shaped portion. A surge absorber, comprising: a discharge type surge absorbing element, which is connected in series with a heating resistor and is hermetically sealed together with a discharge gas, discharge electrodes that are opposed to each other with a discharge gap.