JPH0419750Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a surge absorbing element having a parallel connection structure of a voltage nonlinear resistor and a discharge gap formed between discharge electrodes. A composite surge absorption element that can be suitably used for grounding and between lines in a two-wire circuit, or between lines in a three-wire circuit, by integrating the elements in a delta connection in the same space. Regarding.

[Prior Art] Conventionally, in order to protect electronic circuit elements from excessive abnormal voltages applied to electronic equipment and surges caused by induced lightning, varistors made of voltage non-linear resistors and discharge gaps sealed in airtight containers have been used. Surge absorbing elements such as arresters that utilize discharge phenomena are widely used, and the applicant has already proposed a surge absorbing element having a parallel connection structure of a varistor and an arrester (Japanese Patent Laid-Open No.
59-157981, Utility Model 60-32783, etc.).

The above-mentioned surge absorbing element 8, as shown in FIG.
A pair of discharge electrodes 4, 4 are connected to both ends of the voltage nonlinear resistor 2, facing each other with a discharge gap 5 in between,
It has a structure in which this is sealed together with a discharge gas in an airtight container 7, and external terminals 6, 6 are led out.

When a surge having a voltage higher than the clip voltage of the element is applied to the surge absorbing element 8 having the above configuration, a current immediately flows through the voltage non-linear resistor 2 by the varistor operation and surge absorption is started. A voltage drop occurs across the resistor 2 due to the product of the resistance value of the resistor 2 and the surge current value. As the amount of current increases, this voltage drop also increases, and when this exceeds the discharge starting voltage between the discharge electrodes 4, 4, the voltage between the discharge electrodes 4, 4 is excited in a region close to the nonlinear resistor 2. A discharge occurs, and due to its energization, the discharge instantaneously transfers to the outer area between the discharge electrodes 4 and 4, and an arc discharge, which is the main discharge that conducts a large current, is generated, and this arrester operation causes a surge. Absorbed. In this manner, the surge absorbing element 8 has excellent surge absorbing characteristics that combine the quick response of a varistor and the large current withstand capability of an arrester.

By the way, when using the above-mentioned surge absorption element, a single element is individually connected between each power line or signal line and the ground, and it is incorporated into the circuit to prevent the common mode that enters from between the lines and the ground. Surges are absorbed, and if necessary, single elements are individually connected between each line to absorb normal mode surges that enter between the lines.

For example, in the case of a two-wire circuit such as a single-phase power supply circuit, as shown in FIG.
In the case of a three-wire circuit such as a three-phase power supply circuit, a total of three surge absorbing elements 8 are connected, and as shown in Fig. Therefore, one each between lines a, b, and c, total 6
surge absorbing elements 8 are connected.

[Problems to be solved by the invention] However, as mentioned above, the method of connecting single elements individually requires a large number of elements, which requires a large installation space and increases the cost of surge countermeasures. However, there is a problem in that the connection work becomes complicated.

Furthermore, when a continuous surge is applied, there is a risk that the surge will be applied to the electronic device due to a discharge delay due to variations in the discharge characteristics of each element.

The present invention has been devised in view of the above points, and has both the quick response of a varistor and the large current withstand capability of an arrester, and also has the ability to be used between wires and ground in two-wire circuits, between wires in three-wire circuits, and between wires in three-wire circuits. To realize a composite surge absorption element that is easy to connect between the elements, is small and requires less space for integration into a multiphase circuit, reduces surge countermeasure costs, and prevents discharge delays of each element. The purpose is to

[Means for solving the problem] In order to achieve the above object, the composite surge absorbing element according to the present invention includes one side of a voltage nonlinear resistor having a shape in which a part of the annular body has a defective part. a second varistor electrode facing both the first and third varistor electrodes and a fourth varistor electrode facing the first varistor electrode; In addition to providing
First, second, third, and fourth discharge electrodes are connected to the first, second, third, and fourth varistor electrodes, respectively, and the first discharge electrode and the second discharge electrode are connected to each other. first, second, and third discharge gaps are formed between the second discharge electrode and the third discharge electrode, and between the fourth discharge electrode and the first discharge electrode, respectively; At least one of the third discharge electrode and the third varistor electrode is connected to at least one of the fourth discharge electrode and the fourth varistor electrode in the defective part through a connecting part, and the first varistor a first surge absorbing element having a parallel connection structure of a voltage nonlinear resistor between an electrode and a second varistor electrode and the first discharge gap; and a second varistor electrode and a third varistor electrode. a second surge absorbing element having a parallel connection structure of a non-linear resistor and the second discharge gap; and a non-linear voltage between the fourth varistor electrode and the first varistor electrode. The resistor and the third surge absorbing element having a parallel connection structure with the third discharge gap are integrated by delta connection, and this is sealed in an airtight container together with the discharge gas.

Note that each of the discharge electrodes is formed into a substantially U-shaped cross section with two tip portions, and the first,
between both tips of the first discharge electrode and the second discharge electrode so that second and third discharge gaps are formed on the outer peripheral surface side and the inner peripheral surface side of the voltage nonlinear resistor, respectively. Both tips, both tips of the second discharge electrode and both tips of the third discharge electrode, and both tips of the fourth discharge electrode and both tips of the first discharge electrode are configured to face each other. is desirable.

Further, it is preferable that the third discharge electrode, the fourth discharge electrode, and the connecting portion be integrally formed.

[Function] As described above, the composite surge absorbing element according to the present invention has a parallel connection structure of a voltage nonlinear resistor between opposing varistor electrodes and a discharge gap formed between opposing discharge electrodes. The surge absorbing elements are integrated in the same space in a delta-connected state.

Each of the surge absorbing elements constituting the composite surge absorbing element has excellent surge absorbing characteristics that combine the quick response of a varistor and the large current withstand capability of an arrester. In other words, when a surge having a voltage higher than the clip voltage of each element is applied to each surge absorption element, current immediately flows through the voltage nonlinear resistor due to varistor operation and surge absorption begins, and the resistor A voltage drop occurs across the resistor due to the product of the resistance value of the resistor and the surge current value. As the amount of current increases, this voltage drop also increases, and when this exceeds the discharge starting voltage between the discharge electrodes, an excited discharge occurs in a region close to the voltage nonlinear resistor between the discharge electrodes, and its energization As a result, the discharge instantly transfers to the area outside the discharge electrode, and an arc discharge, which is the main discharge that conducts a large current, is generated, and the surge is absorbed by this arrester operation.

To implement the above composite surge absorbing element in a circuit, in the case of a two-wire circuit, connect each of the above electrodes to each line and the ground, and the surge absorbing element will be incorporated between the lines and the ground, and between the lines. Furthermore, in the case of a three-wire circuit, by connecting each of the above electrodes to each line, a surge absorbing element is incorporated between the lines.

When continuous surges are applied to the above composite surge absorbing element, ions are generated by the discharge of the element due to the first surge application, and since each element exists in the same space, the ion priming effect is Therefore, the response speed of the element becomes faster, and no matter which element the next surge is applied to, the surge is instantly absorbed.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1 to 3 show a composite surge absorbing element 1 according to an embodiment of the present invention, and FIG.
1B is an enlarged sectional view of the main part, FIG. 2 is a perspective view, and FIG. 3 is an equivalent circuit diagram.

In the figure, the composite surge absorbing element 1 is made of a material whose main component is a metal oxide such as ZnO, BaTiO ₃ , SiC, etc., and has a circular annular body with a generally rectangular cross section. A first varistor electrode 3 is disposed on the upper surface of the voltage nonlinear resistor 2, which has a substantially horseshoe-shaped or C-shaped planar shape.
A and a third varistor electrode 3c are provided, and a second varistor electrode 3b is provided on the lower surface of the resistor 2, facing a part of the first varistor electrode 3a and a part of the third varistor electrode 3c. Further, a fourth varistor electrode 3d is formed to face a part of the first varistor electrode 3a.

The first, second, third, and fourth varistor electrodes 3a, 3b, 3c, and 3d are formed by baking, spraying, vapor depositing, or the like a metal material such as silver or aluminum on the surface of the voltage nonlinear resistor 2. This is an ohmic connection.

Further, the first, second, third and fourth varistor electrodes 3a, 3b, 3c and 3d are provided with a first
Second, third and fourth discharge electrodes 4a, 4b, 4
c and 4d, between the first discharge electrode 4a and the second discharge electrode 4b, between the second discharge electrode 4b and the third discharge electrode 4c, and between the fourth discharge electrode 4.
d and the first discharge electrode 4a, respectively.
Second and third discharge gaps 5ab, 5bc, and 5da are formed.

The first, second, third and fourth discharge electrodes 4
a, 4b, 4c, and 4d are metal plates with good discharge characteristics, such as nickel, iron, or their alloys, which are formed into a substantially U-shaped cross section by press working, and the opposing discharge electrodes Weld or conductive adhesive is applied to the first, second, third and fourth varistor electrodes 3a, 3b, 3c and 3d, respectively, with their tips facing each other so that the discharge gaps are formed between them. It is connected by etc.

As mentioned above, since the discharge electrodes are formed to have a substantially U-shaped cross section, they each have two tips, and a discharge gap is formed on both the outer circumferential surface side and the inner circumferential surface side of the voltage nonlinear resistor 2. can do.

Further, the third discharge electrode 4c and the fourth discharge electrode 4d are connected at the defective portion of the voltage nonlinear resistor 2 via a connecting portion 4cd. The connecting portion 4cd, the third discharge electrode 4c, and the fourth discharge electrode 4d are integrally formed, and the connecting portion 4cd vertically passes through the defective portion of the voltage nonlinear resistor 2. , the third discharge electrode 4c
and a fourth discharge electrode 4d are arranged on the upper and lower surfaces of the voltage nonlinear resistor 2, respectively.

In this way, the third discharge electrode 4
By connecting both the discharge electrodes via the connecting portion 4cd formed integrally with the fourth discharge electrode 4c and the fourth discharge electrode 4d, it is possible to reduce the size of the device and simplify the structure.

However, the connecting portion 4cd and the third discharge electrode 4c
Instead of integrally forming the third discharge electrode 4c (third varistor electrode 3c) and the fourth discharge electrode 4d, a separate connecting portion is formed between the third discharge electrode 4c (third varistor electrode 3c) and the fourth discharge electrode 4d.
(The fourth varistor electrode 3d) may be connected to the fourth varistor electrode 3d.

Furthermore, the first, second and third discharge electrodes 4
External terminals 6a, 6b, and a, 4b, and 4c are respectively connected to
6c, and as shown in Figure 2, it is placed in an airtight container 7 made of an insulating material such as ceramic or glass, containing mainly an inert gas such as a rare gas (He, Ne, Ar, etc.) or nitrogen gas. sealed with discharge gas,
The external terminals 6a, 6b, 6c are led out from the airtight container 7. Note that the external terminal 6c
may be connected to the fourth discharge electrode 4d.

Thus, inside the composite surge absorbing element 1,
First varistor electrode 3a and second varistor electrode 3
between the first surge absorption element having a parallel connection structure of the voltage nonlinear resistor 2ab and the first discharge gap 5ab, and the second varistor electrode 3b and the third varistor electrode 3c. Voltage nonlinear resistor 2
bc and the second discharge gap 5bc, a voltage nonlinear resistor 2da between the fourth varistor electrode 3d and the first varistor electrode 3a, and the third A total of three third surge absorbing elements having a parallel connection structure with the discharge electrode 5da
surge absorbing elements are formed.

Each of these surge absorbing elements is connected to a first varistor electrode 3a (first discharge electrode 4) as shown in FIG.
a), second varistor electrode 3b (second discharge electrode 4
b), third varistor electrode 3c (third discharge electrode 4
c) They are integrated in the same space in a delta-connected state via the connecting portion 4cd and the fourth varistor 3d (fourth discharge electrode 4d).

Therefore, in order to mount the composite surge absorbing element 1 of this embodiment in a single-phase circuit, each external terminal 6a, 6
If you connect b and 6c to each line of the circuit and ground,
Surge absorption elements are installed between the circuit line and ground, and between the lines, making it possible to absorb common mode surges and normal mode surges. In the case of a three-phase circuit, if each external terminal 6a, 6b, 6c is connected to each line of the circuit, a surge absorption element is incorporated between the lines of the circuit, making it possible to absorb normal mode surges.

In addition, when continuous surges are applied to the composite surge absorbing element 1, ions are generated by the discharge of the element due to the first surge application, and since each element exists in the same space, ions are generated. The priming effect increases the response speed of the element,
No matter which element the next surge is applied to, it will be absorbed instantly.

The clipping voltage of the composite surge absorbing element 1 can be adjusted by adjusting the thickness of the voltage nonlinear resistors 2ab, 2bc, and 2da, and the discharge starting voltage can be adjusted by adjusting the thickness of the voltage nonlinear resistors 2ab, 2bc, and 2da. 5ab, 5bc,
By adjusting the length of 5da, it can be easily set to a desired value.

Therefore, as in this embodiment, the characteristics of each element may be made the same, or the clip voltage of one element may be set to a smaller value than the clip voltage of the other two elements, etc., as necessary. It is also possible to form elements having different characteristics.

[Effects of the invention] As detailed above, the composite surge absorbing element of the present invention is configured so that three surge absorbing elements are connected in delta and integrated, so it is possible to significantly reduce surge countermeasure costs, and It is small, requires less space for integration into a circuit, and can be easily integrated into a circuit.

In addition, each of the above surge absorption elements has a parallel connection structure of a voltage nonlinear resistor and a discharge gap, so it provides excellent surge absorption that combines the quick response of a varistor and the large current withstand capability of an arrester. It can demonstrate its characteristics.

In addition, since three surge absorbing elements are arranged in the same space, when continuous surges are applied to the above composite surge absorbing element, ions are generated by the discharge of the element due to the first surge application. The priming effect of ions increases the response speed of the element, and no matter which element the next surge is applied to, the surge is instantly absorbed. Therefore, delay in discharge of each element can be effectively prevented.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, in which FIG. 1A is a partially cutaway perspective view of the main part, FIG. 1B is an enlarged sectional view of the main part, FIG. 2 is a perspective view, and FIG. 3 is an equivalent circuit diagram, FIG. 4 is a schematic sectional view of the conventional example, and FIGS. 5A and 5B are circuit diagrams showing the connection state of the conventional example. DESCRIPTION OF SYMBOLS 1... Composite surge absorption element, 2... Voltage nonlinear resistor, 2ab, 2bc, 2da... Voltage nonlinear resistor between varistor electrodes, 3a... First varistor electrode, 3b... Second Varistor electrode, 3c... Third varistor electrode, 3d... Fourth varistor electrode, 4a... First discharge electrode, 4b... Second discharge electrode, 4c... Third discharge electrode, 4d... …Fourth
discharge electrode, 4cd...discharge electrode connection part, 5ab,
5bc, 5da...first, second, third discharge gaps,
7...Airtight container.

Claims (1)

[Claims for Utility Model Registration] (1) First and third resistors are formed on one surface of a voltage nonlinear resistor having a shape with a cutout in a part of an annular body.
a second varistor electrode facing both the first and third varistor electrodes and a fourth varistor electrode facing the first varistor electrode are provided on the other surface; First, second, third and fourth discharge electrodes are connected to the second, third and fourth varistor electrodes respectively, and a second discharge electrode is connected between the first discharge electrode and the second discharge electrode. First, second, and third discharge gaps are formed between the discharge electrode and the third discharge electrode and between the fourth discharge electrode and the first discharge electrode, respectively, and the Connecting at least one of the third discharge electrode and the third varistor electrode to at least one of the fourth discharge electrode and the fourth varistor electrode via a connecting portion,
This is sealed together with a discharge gas in an airtight container, and a second varistor having a parallel connection structure of a voltage non-linear resistor between the first varistor electrode and the second varistor electrode and the first discharge gap is provided. A second surge absorbing element having a parallel connection structure of the first surge absorbing element, a voltage nonlinear resistor between the second varistor electrode and the third varistor electrode, and the second discharge gap.
and a third surge absorption element having a parallel connection structure of a voltage nonlinear resistor between the fourth varistor electrode and the first varistor electrode and the third discharge gap, A composite surge absorption element that is integrated by delta connection in the same space. (2) Each of the discharge electrodes is formed into a substantially U-shaped cross section with two tips, and the first, second, and third discharge gaps are located on the outer circumferential surface of the voltage nonlinear resistor, respectively. and both tip portions of the first discharge electrode and both tip portions of the second discharge electrode, both tip portions of the second discharge electrode and both tip portions of the third discharge electrode so as to be formed on the inner peripheral surface side. The composite surge absorbing element according to claim 1 of the utility model registration claim, characterized in that both the tip portion and both tip portions of the fourth discharge electrode and both tip portions of the first discharge electrode are opposed to each other. . (3) The composite type according to claim 1 or 2 of the utility model registration claim, characterized in that the third discharge electrode, the fourth discharge electrode, and the connecting portion are integrally formed. Surge absorption element.