JPH03230485A - Surge absorbing element for overvoltage/overcurrent protection - Google Patents

Abstract

PURPOSE:To shorten the cutoff time by providing a low-melting point metal wire in a close contact state so that a surge absorbing element is brought into contact in the peripheral direction of an outer body. CONSTITUTION:Lead pins 1-4 each provided with a constricted part at the center section of the pin are driven into a base material 5. The length of the lead pins 1-4 is set to 10.0mm for metal wires 1, 3 and 6.0mm for metal wires 2, 4. Lead terminals on both ends of a micro-gap type surge absorbing element 6 are connected by spot welding to the pins 1, 3, then a zinc wire 7 as a low- melting point metal wire is arranged in contact with the peripheral direction of the element 6 at the center section of the element 6, and both ends of the wire 7 are connected to the pins 2, 4 by welding. A case 8 is fixed to the base material 5 to cover the element 6 and the wire 7.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a surge absorbing element f having an overvoltage A current protection function, and in particular, to improving the cut-off speed and improving the mounting characteristics on a board. The present invention relates to a surge absorbing element that is

[Prior Art and Problems to be Solved by the Invention] Surge absorbing elements are for devices connected to telephone lines, such as telephones, facsimiles, and telephone exchanges. In this case, when an overvoltage/current is applied to the surge absorbing element, the low melting point metal wire melts due to heat and breaks, thereby protecting the surge absorbing element from the overvoltage. In conventional surge absorbing elements having such an overvoltage/overcurrent protection function, a low melting point metal wire is attached to the surface of a cap type or microgap type surge absorbing element, and a wire is attached around the low melting point metal wire and the surge absorbing element. , provided a surge absorbing element for overvoltage and overcurrent protection with a structure covered with an inorganic material outer cover. It has a structure in which lead terminals are provided at both ends of this inorganic material outer cover. That is, a conventional surge absorbing element with an overvoltage/overcurrent protection function has a structure as shown in FIG. 2 disclosed in Japanese Patent Laid-Open No. 63-205026.

In the prior art, low melting point metal wires are closely spaced parallel to the axial direction of a gap type or microgap type surge absorption element. In other words, when overvoltage and overcurrent are applied, the gap type or micro gear type surge absorption element generates heat as follows:
In the prior art, where the center gap or microgap area is high, the area of the low melting point metal wire that is in close contact with the center part is small, so the time required to shut off is long. The heat generated by the gap-type surge absorption element has also increased. For this reason, it was necessary to cover the entire gap type or microphone type gap type surge absorption element and the low melting point metal wire with an inorganic material jacket.

In order to solve the drawbacks of the prior art, the present invention improves the method of bringing a gear 7-type or micro-gear 71 type surge absorbing element into close contact with a low melting point metal wire compared to conventional products, and heat is concentrated on the low melting point metal wire,
It is an object of the present invention to provide a surge absorption element with an overvoltage/overcurrent protection function that can have the same characteristics as conventional products without using an inorganic material outer cover.

[Structure of the invention] [Means for solving the problems] The gist of the present invention is to use a gap type or microphone [1
In a surge absorbing element having an overvoltage/overcurrent protection function consisting essentially of a gap type surge absorbing element and a low melting point metal wire provided in contact therewith, in the circumferential direction Jj of the central part of the outer cover of the surge absorbing element. The low melting point metal wires are closely stretched so that they touch each other, and both lead wires of the surge absorbing element and both ends of the low melting point metal wires are each independently attached to lead terminals provided on the resin base. A surge absorbing element having an overvoltage/overcurrent protection function, characterized by a structure in which the entire surge absorbing element f assembled as described above and the low melting point metal wire are protected by a protective case. be.

[Function] According to the present invention, in a surge absorption element for overvoltage/overcurrent protection that essentially consists of a gap type or microgap type surge absorption element and a low melting point metal wire provided in contact with the surge absorption element, the most The low melting point metal wire is placed in close contact with the central part in the circumferential direction, which generates a high amount of heat, so that the same characteristics as in the conventional technology can be obtained without using the inorganic material jacket of the conventional technology. It is something.

That is, in the conventional technology, the low melting point metal wire is connected parallel to the axial direction of the gap type or micro gap type surge absorbing element, but in the surge absorbing element for overvoltage and overcurrent protection according to the present invention, the center where the heat generation is highest is The low melting point metal wire can be closely spaced in the circumferential direction of the surge absorbing element, making it easier for the heat generated by the surge absorbing element to be transmitted to the low melting point metal wire. This allows the same characteristics as those of the conventional technology to be obtained.

Therefore, in the surge absorbing element having the overvoltage/overcurrent protector of the present invention, the low melting point metal wire is disposed in close contact with the circumferential direction of the central part of the outer cover of the surge absorbing element, and A large amount of heat is transferred to the melting point metal wire, and the structure of the outer cover etc. can be simplified compared to conventional products.

Furthermore, both lead wires of the surge absorbing element and both ends of the low melting point metal wire are each independently attached to lead terminals provided on the resin base, which improves workability when mounting the surge absorbing element. is improved.

The surge absorbing element of the present invention can be used in equipment connected to telephone lines, such as telephones, facsimile machines, and telephone exchanges.

Next, the surge absorbing element with the overvoltage/overcurrent protection function of the present invention will be explained using specific examples, but the present invention is not limited by the explanation.

[Example] This embodiment is shown in FIG.

A pin having a diameter of 0.8 cm with a constriction in the center was driven into a base material 5 made of PBT to form the structure shown in FIG.

The length of the lead pin is 1.3 and the length of the metal wire is 10.
For 0 cabinet and metal +112.4, a length of 6.0 m was used.

As a surge absorption element, the outer size is 7. Oma length x 3.3
It uses a micro-gap type surge absorption element (discharge starting voltage 300V) 6 with a diameter of IΦ, and the -ficro gear 7
After the node terminals at both ends of the surge absorbing element 6 are electrically connected to the lead pins 1.3 by spot welding, the central part of the surge absorbing element is brought into contact with the circumferential direction of the surge absorbing element. In addition, zinc wire 7 is used as a low melting point metal wire.
After placing the metal wire 7, both ends of the low melting point metal wire 7 are connected to the lead pins 2.
．． 4. I made an electrical connection using solder.

Furthermore, this -ficro gear type surge absorption element 6,
A case 8 made of PBT was fixed to the base material 5 so as to cover the low melting point metal wire 7.

The conventional surge absorbing element with overvoltage/overcurrent protection function and the surge absorbing element according to the embodiment of the present invention have AC 600V-
Table 1 shows the cut-off time of the low melting point metal wire when an overvoltage and overcurrent of 2.2 A is applied in series to the micro gear 7 type surge absorbing element 6 and the low melting point metal wire 7.

Table 1 Conventional products Example products Low-melting point metal rod Zinc wire Zinc wire cover glass Yes No Applied voltage AC600V AC600
V2.2A 2.2A test results
Fuses out in 2 to 6 seconds Fuses out in 2 to 6 seconds As shown in FIG. Even without using an inorganic outer covering such as a cover glass as in the product, similar interrupting characteristics can be obtained when overvoltage and overcurrent are applied.

In addition, it becomes possible to suppress the thermal influence on the board on which it is mounted, thereby increasing safety.

In addition, compared to conventional products, the lid wire of the surge absorption element is
It is fixed to the base through lead pins, and the low melting point metal wire is also fixed to the base through lead pins, so it can be assembled using the lead pins on the base when mounting the board, significantly improving work efficiency. be done.

[Effects of the Invention] The surge absorbing element having an overvoltage/overcurrent protection function of the present invention has the low melting point metal wires brought into close contact with each other in the circumferential direction of the central part of the outer cover of the surge absorbing element. established,
Furthermore, both J-F wires of the surge absorbing element and both ends of the low melting point metal wire are each independently attached to the lead terminal □ provided on the resin base, and the surge absorbing element assembled as above The entire element f and the low melting point metal wire are covered with a protective case,
It is a surge absorbing element with a protected structure, and as a result, the following remarkable technical effects can be obtained. That is, firstly, it is possible to provide a Cern absorbing element f for overvoltage and overcurrent protection, in which heat is easily transmitted to the low melting point metal wire, the melting occurs quickly, and the cut-off time is shortened, compared to the conventional technology. Ta.

Second, the present invention provides a surge absorbing element for overvoltage A current protection, which has a structure that can improve work efficiency even when mounting the surge absorbing element.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a surge absorbing element having an overvoltage/overcurrent protection function according to the present invention. FIG. 2 is a sectional view showing a surge absorbing element with a conventional overvoltage/overcurrent protection function. 1. 51. . 69. . 7. 81. . [Explanation of symbols of main parts] 2.3.4 , , , , , Lead pin 6 , Base material (PBT) 0. Microgap type 89. Low melting point metal wire 11. Case absorption element

Claims (1)

[Claims] 1. A surge absorption element having an overvoltage/overcurrent protection function consisting essentially of a gap type or microgap type surge absorption element and a low melting point metal wire provided in contact with the surge absorption element, comprising: The low melting point metal wires are provided in close contact with each other in the circumferential direction of the central portion of the outer cover, and both lead wires of the surge absorbing element and both ends of the low melting point metal wires are provided independently. It has a structure in which it is attached to lead terminals provided on a resin base, and the entire surge absorbing element and low melting point metal wire assembled as described above are covered with a protective case.
A surge absorption element with overvoltage and overcurrent protection function characterized by a protected structure.