JPH0454695Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an insulating structure for an external terminal used in, for example, a line filter, in which the external terminal protrudes outside from within a metal case.

[Conventional technology]

FIG. 4 is a partially cutaway side view of a line filter using a conventional insulating structure.
FIG. 5 is a front view thereof. This line filter 1 includes, for example, two filter elements (not shown) made of L, C, LC, etc., insulated by two insulating plates, and more specifically, an insulating case 4 having a split structure.
A, 4b are housed and insulated in the metal case 2, and two external terminals 10 for input or output (one not shown in the figure) connected to each filter element are connected to the metal case 2. It protrudes from the opening 3 and is insulated as described below.

That is, insulating protrusions 8a and 8b each having a U-shaped cross section are provided at opposing positions of the joint parts (joint surfaces) 6 of the insulating cases 4a and 4b, and the external terminal 10 is sandwiched between both the insulating cases 4a and 4b. Insulating protrusion 8
a and 8b and protrudes outward from the opening 3 of the metal case 2.

[Problem that the invention attempts to solve]

In the above case, according to safety standards, the external terminal 10
It is necessary to ensure a certain creepage distance between the metal case 2 and the metal case 2. However, in the above structure, since there is a joint part between the insulating cases 4a and 4b between the external terminal 10 and the metal case 2, the straight line distance L ₁ between the two at that part (Fig. (bold line part) is one creepage distance, and the other creepage distance is the distance to get over the insulating protrusion 8a or 8b, as shown by _L2 in the figure, and the withstand voltage is determined by whichever is shorter.

In that case, when securing a predetermined creepage distance, distance L ₂ can be easily set larger than distance L ₁ because it includes the height direction;
In order to increase L ₁ , it is necessary to increase the width W ₁ of the insulating protrusions 8a and 8b, which increases the size of the line filter 1 itself and causes an increase in its price.

Therefore, an object of this invention is to provide an insulating structure for an external terminal that can ensure a large creepage distance without increasing the dimensions of the insulating protrusion, for example in the above-mentioned case.

[Means for solving problems]

The insulating structure of the external terminal of this invention is such that insulating protrusions each having a U-shaped cross section are provided at opposite positions of the joint of two insulating plates, and the external terminal is sandwiched between both insulating plates and surrounded by both insulating protrusions. and protruding outward from the opening of the metal case, one of the two insulating protrusions having a U-shaped cross section is retracted from the main part of the joint part, and the other insulating protrusion is retracted from the main part of the joint part. The two insulating protrusions protruding from the main part of the joining part are interlocked with each other to form a single box-like shape, and the insulating plate in a portion partially surrounded by the one insulating protrusion is made convex, and the insulating plate of the other insulating plate is made convex. The insulating plates in the portions partially surrounded by the insulating protrusions are made concave so that they engage with each other, and the external terminals are sandwiched between the engaged portions.

[Effect]

In the protruding part of the external terminal, the two insulating protrusions and the parts of the two insulating plates surrounded by the insulating protrusions are engaged with each other, so the horizontal creepage distance between the external terminal and the metal case is reduced. becomes the bending distance and becomes sufficiently large.

〔Example〕

FIG. 1 is a front view partially showing a line filter using the insulating structure according to the invention with the metal case taken out, and FIG. 2 is an exploded view thereof. FIG. 3 is a partial sectional view taken along line - in FIG. 1.

External terminal 10 in this line filter 11
The insulation structure consists of two insulation plates, more specifically two
Insulating protrusions 1 having a U-shaped cross section are located at opposing positions of the joint portion 16 of the insulating cases 14a and 14b having a split structure.
8a and 18b are respectively provided, and the external terminal 10 is sandwiched between both insulating cases 14a and 14b, and is surrounded by both insulating protrusions 18a and 18b and protrudes outward from opening 3 of metal case 2 (see FIG. 3). This is the same as the conventional method, but unlike the conventional method, the insulating protrusion 18a is retracted from the main part of the joint part 16, and the insulating protrusion 18b is protruded from the main part of the joint part 16 (see FIG. 2), and the insulation is The inner diameter of the protrusion 18a is set to a size that allows the insulating protrusion 18b to fit therein, and the two insulating protrusions 18a, 18
b are interlocked with each other to form one box shape, and the insulating case 14a in the part surrounded by the insulating protrusion 18a is made convex, and the insulating case 14b in the part surrounded by the insulating protrusion 18b is made in a concave shape. The external terminals 10 are sandwiched between the meshing portions and the external terminals 10 are interlocked with each other.

In this embodiment, the creepage distance between the external terminal 10 and the metal case 2 is the distance L ₂ including the height direction as described above (see Fig. 1), and the joint portion 16
Because it is bent, the distance L ₃ (thick line in Figure 1) is bent in a U-shape in the horizontal direction, and furthermore, the distance L ₄ (thick line in Figure 3) in the width direction including the height direction. ), and the withstand voltage is determined by the shortest distance L ₂ to L ₄ .

In that case, the distances L ₂ and L ₄ include the height direction as described above, so it is easy to determine the distances L 2 and L 4 (i.e., the insulating protrusion 18
(without increasing the widths of a and 18b or the shape of the line filter 11 itself), and the distance L ₃ is curved, unlike the distance L ₁ in the conventional case (see Figure 5). Therefore, it can be easily made larger.

Although not specifically indicated by thick lines in the figure, there are creepage areas corresponding to these L ₂ to L ₄ at positions symmetrical to the distances L ₂ to _{L 4} shown in thick lines in the figure across the external terminal 10. Needless to say, a distance is created.

Therefore, according to the above structure, it is possible to reduce the width W ₂ of the insulating projection 18a (and the width of the insulating projection 18b) while ensuring the necessary creepage distance, thereby making the line filter 11 smaller. can be converted into Furthermore, the miniaturization can also reduce the cost of the product.

Although the embodiment has been described above using a line filter as an example, this invention is not limited thereto, and insulating protrusions having a U-shaped cross section are provided at opposing positions of the joint portion of two insulating plates. Of course, it can be widely applied to devices in which the external terminal is sandwiched between both insulating plates, surrounded by both insulating protrusions, and protrudes outward from the opening of the metal case.

[Effect of idea]

As described above, according to this invention, a large creepage distance can be secured between the external terminal and the metal case without increasing the dimensions of the insulating protrusion. Therefore, by adopting the insulating structure of the present invention, it is possible to downsize the product, and
Along with this, it is also possible to reduce the cost of the product.

[Brief explanation of drawings]

FIG. 1 is a front view partially showing a line filter using the insulating structure according to the invention with the metal case removed, and FIG. 2 is an exploded view thereof. FIG. 3 is a partial sectional view taken along line - in FIG. 1. FIG. 4 is a partially cutaway side view of a line filter using a conventional insulating structure, and FIG. 5 is a front view thereof. 1, 11... Line filter, 2... Metal case, 3... Opening, 4a, 4b, 14a, 14b
... Insulation case, 6, 16 ... Joint part, 8a,
8b, 18a, 18b...Insulating protrusion, 10...External terminal.

Claims (1)

[Scope of utility model registration request] Insulating protrusions each having a U-shaped cross section are provided at opposite positions of the joining portion of two insulating plates, and the external terminal is sandwiched between both insulating plates, surrounded by both insulating protrusions, and protruded outward from the opening of the metal case. wherein one of the two insulating protrusions having a U-shaped cross section is retracted from the main part of the joint part, and the other insulating protrusion protrudes from the main part of the joint part to form two insulating protrusions. The insulating protrusions are interlocked with each other to form a single box shape, and the insulating plate is made convex in a portion partially surrounded by the one insulating protrusion and insulated in a portion partially surrounded by the other insulating protrusion. An insulating structure for an external terminal, characterized in that the plates are formed into concave shapes so that they engage with each other, and the external terminal is sandwiched between the engaged portions.