JPS6222071Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a spark gap element that protects electrical equipment, electronic components, etc. from overvoltage. Conventionally, a spark gap element having a spherical electrode shape is known to have a stable discharge voltage and a short discharge response time, but it has not been used much because of its high manufacturing cost. Furthermore, as shown in FIGS. 1 and 2, a spark gap element has been proposed in which a pair of metal plate electrodes with curved peripheral edges are opposed to each other. In Figure 1, the non-opposing surface of a metal plate electrode 1 is connected to an insulating base 2.
An example of soldering or adhering with conductive paint, etc. to the end of the lead terminal 3 ₁ embedded in and supported by the metal plate electrode 1 is shown in FIG _.
This is an example in which the large diameter portion 5 at one end of the large diameter portion 5 is adhesively fixed to the bottom surface of the recess 6 of the metal plate electrode 1 so that the large diameter portion 5 has no relation to electric discharge. This figure 1 and 2
The one in the figure uses metal plate electrodes, so the metal plate electrode 1 must be supported away from the base 2 in order to make the inter-electrode creepage distance sufficiently long. Therefore, the length of the lead terminals 3 ₁ and 3 ₂ It is necessary to increase the length of the base body 2 in the longitudinal direction. Therefore, there is a drawback that the shape of the base body 2 becomes large and the cost becomes high. The purpose of the present invention is to eliminate the drawbacks of conventional spark gap elements and to obtain a spark gap element that is low cost, small, and has excellent discharge characteristics. A flange-like body made of a dielectric material having a dielectric constant of 2000 or more is attached to the tip portion through the electrode, and the flange-like bodies are opposed to each other. Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. FIG. 3 is a partially cutaway side view of an embodiment of the present invention;
FIG. 4 is a perspective view of the linear conductive electrode 7 used in this embodiment and the collar-shaped body 8 made of a dielectric material attached thereto. 9 is a hemispherical crushed portion at the tip of the linear conductor electrode 7;
10 is a groove for fitting the linear conductor electrode 7, 11 is an insulating base for supporting the conductor electrode made of synthetic resin, etc., 12 is a terminal portion drawn out from both sides of the lower surface, and the best shape for the collar-shaped body 8 is a circular one. However, it is not limited to this form. Further, instead of the groove 10, a hole may be used.
The collar-shaped body 8 attached to the linear conductor electrode 7 has a dielectric constant of
It is a dielectric material of more than 2000. When a collar-shaped body made of a dielectric material with a dielectric constant of 2000 or more is used, when a voltage containing many high-frequency components such as a surge voltage is applied between the linear conductor electrodes 7, the impedance of the collar-shaped body (1/WC ) decreases, so the electric lines of force tend to wrap around from the center of the brim to the periphery, and as a result, the density of the electric lines of force near the center decreases,
It is considered that the electric field approaches a uniform electric field compared to the case where the brim-shaped body 8 is not provided. As a result of the electric field formed in the spark gap element approaching a uniform electric field, the stability of the discharge voltage is greatly improved and the discharge response time is shortened. Furthermore, since the collar-shaped body 8 made of a dielectric material can be brought into contact with the insulating base 11 as shown in FIG. 3, it is similar to the lead terminal shown in FIGS. Since the creepage distance between the electrodes along the frame 11 is not shortened, there is no need to increase the shape of the frame 11 in any way. Figure 5 shows samples a and b of the present invention shown in the table below.
and shows the discharge voltage (vertical axis) characteristics with respect to the distance between the electrodes (horizontal axis) for sample c without a brim-shaped body and sample d using a hemispherical metal plate electrode. Note that a hemispherical metal plate electrode is known to exhibit excellent discharge characteristics, so this was shown as a reference sample.

[Table] For sample c without a flange, the discharge voltage reaches saturation at around 10 KV, and even if the interelectrode voltage is increased beyond this, the discharge voltage does not rise much. However, samples a and b, which are embodiments of the present invention, have a higher discharge voltage than sample c, and do not show any tendency to saturate even at 12 KV. In particular, sample a with ε = 10,000 has a discharge voltage that is increased by more than 10% compared to sample c, and exhibits characteristics almost identical to those of a hemispherical electrode (sample d), which exhibits excellent characteristics as a spark gap electrode. As a result, the use of the flange 3 makes it possible to significantly narrow the interelectrode distance compared to a case without a flange, making it possible to miniaturize the product. Figure 6 shows the characteristics of discharge response time (vertical axis) versus applied voltage (horizontal axis) for samples a to d (discharge voltage
6 shows the discharge response times at 7 KV for the samples a and b of the present invention, which are 0.11 and 0.36 μsec, respectively, while the conventional samples c and d have the times of 3.2 and 0.07 μsec at the same voltage. At 8 KV, the times for the samples a and b are 0.1 and 0.14 μsec, respectively, while the times for the samples c and d are 1.8 and 0.063 μsec. From this figure, it can be seen that the discharge response times of the samples a and b are 10 to 100 times faster than that of the sample c. It is considered that the spark gap must have a discharge response time of 1 μsec or less when a voltage twice the discharge voltage is applied in order to prevent the insulation breakdown of other electric parts, and both the samples a and b meet this requirement. Thus, according to the present invention, by attaching a flange-shaped body made of a dielectric with a dielectric constant of 2000 or more to the linear conductor electrode, it is possible to obtain superior discharge voltage stability and shorter discharge response time characteristics compared to those without a flange-shaped body, and it can be easily manufactured without the manufacturing difficulties and high costs associated with hemispherical metal plates. It can also be made smaller than those using flat metal plate electrodes. Furthermore, since the electric field strength between the conductor electrodes can be changed by changing the material and shape of the flange-shaped body, it has the effect of being able to obtain a variety of discharge voltages with electrodes of the same shape.

[Brief explanation of the drawing]

1 and 2 are a side view and a sectional view, respectively, of a spark gap element using metal plate electrodes that has already been proposed, FIG. 3 is a partially cutaway sectional view of an embodiment of the present invention, and FIG. A perspective view of the linear conductor electrode and the flange body of this embodiment, Fig. 5 is a discharge voltage characteristic diagram with respect to the inter-electrode distance of the present invention and the conventional one, and Fig. 6 is a discharge response time with respect to the applied voltage of the present invention and the conventional one. A characteristic diagram is shown. 1... Metal plate electrode, 2... Insulating base, 3 ₁ , 3
₂ ...Terminal lead, 4...Hole, 5...Large diameter part, 6
... recess, 7 ... linear conductor electrode, 8 ... collar-shaped body made of dielectric, 9 ... crushed portion, 10 ... groove,
11... Insulating base, 12... Terminal portion.

Claims (1)

[Scope of utility model registration request] A collar-shaped body made of a dielectric material having a dielectric constant of 2000 or more is attached to the tip of each of the linear conductive electrodes forming the spark gap, and the collar-shaped body is penetrated by the electrode, and the collar-shaped bodies are opposed to each other. A spark gap element featuring: