JPS6014485B2 - How to bond lightning arrester elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for stacking a lightning arrester element (hereinafter simply referred to as an element) consisting of a non-linear resistor mainly composed of zinc oxide and used as an internal element by laminating a plurality of non-linear resistors. This relates to an adhesion method.

When bonding two elements, a metal body that can be easily induction heated is brought into contact with the upper and lower end surfaces of the laminated element with the fusible alloy (solder) sandwiched between the surfaces to be bonded. As an efficient bonding method, the eddy current due to high frequency transfer is transferred to the eddy current, and the generated heat is transferred to the fusible alloy through the element, thereby heating and melting the fusible alloy and bonding the elements together. Proposed.

To apply this bonding method to the case where three or more elements are stacked, as shown in Fig. 1, elements IA, IB and IB
, three elements IA, IB, and IC are placed in a neck layer with fusible alloys 2 and 2 sandwiched between the ICs, and a lower metal body 3A and an upper metal body 3B are placed on both end faces of the elements, and the lower Heating coils 4A and 48 are arranged to surround upper metal bodies 3A and 3B.

When bonding, the three elements IA and I in a stacked state are bonded.
B, while applying pressure to the metal bodies 3A, 3B on both end faces of the IC, a high frequency current is passed from the high frequency power source 5 to the heating coils 4A, 4B to induce eddy currents in each metal body 3A, 3B, and the generated heat is The fusible alloys 2, 2 are melted by heat transfer. However, with this method, when there are two elements, it can be bonded efficiently, but when there are three elements as shown in FIG. Even if it reaches the melting temperature, both sides B of the intermediate element IB,
Since C may not reach the melting temperature, cuts 21 may occur on the solder melting surface 201 due to insufficient preheating of the element as shown in FIG. 2, which may result in poor adhesion.

In addition, as a method for bonding three or more horizontally layered elements, each element is placed in a heating furnace with a fusible alloy sandwiched between the surfaces to be bonded, and each bonding part is heated and melted at once. There is a method of adhesion, but it has the disadvantage that adhesion takes a long time and consumes a lot of power.

It is an object of the present invention to provide a method for bonding elements for an earth arrester, which eliminates the above-mentioned drawbacks and allows for reliable and efficient bonding of multiple elements, especially when three or more elements are laminated. shall be.

In the method of the present invention, two elements are first bonded by heat transfer from the upper and lower metal bodies to the fusible alloy through the elements, and then the upper metal body is pulled up and the fusible alloy is temporarily attached. Attach the heated elements, and when the upper surface temperature of the upper layer element, which has been bonded for the first time, has fallen to near the appropriate temperature for soldering, press down on the upper metal body and pressurize each element at the same time.
This is characterized in that the upper metal body is moved to a position at the height of the upper metal body and a high frequency current is passed through the upper heating coil to heat the upper metal body.

Embodiments of the method of the present invention will be described below with reference to the drawings.

In FIGS. 3 and 4, IA, IB, and IC are elements,
2 is a fusible alloy (solder), 3A is a lower metal body, 3B is an upper metal body, 4A is a lower heating coil, 4B is an upper heating coil, 5 is a high frequency power supply, 6 is a pressure device bed, 7 is an alloy,
8 is the pusher.

The alloy 7 is installed on the bed 6, and the lower metal body 3A is disposed on the upper surface thereof. The lower heating coil 4A is arranged so as to surround the lower metal body 3A. Further, the upper heating coil 48 is arranged so as to surround the upper metal body 3B, but since the upper metal body 3B attached to the pusher 8 moves in the vertical direction, the upper heating coil 4B can also move up and down. The height is adjusted so that it always surrounds the upper metal body 3B during heating. Although not shown, the lower and upper metal bodies 3A and 3B are provided with a holding mechanism that allows the elements to be easily attached and detached.

Here, when bonding the elements, first, as shown in FIG. 3, the element IA is held on the lower metal body 3A, the element IB with the fusible alloy 2 temporarily attached to the lower surface is attached to the upper metal body 3B, and the element IA is attached to the upper metal body 3B.
The pressurizing device is operated so as to sandwich the fusible alloy 2 between A and IB.

That is, the pusher 8 is lowered to the illustrated state.

In this case, the position of the upper heating coil 4B is adjusted so that the height corresponds to the position of the upper metal body 38 when two elements are laminated. In this way, both heating coils 4A,
When a high frequency current is passed through 4B, eddy currents are generated in the metal bodies 3A and 3B, and the metal bodies 3A and 38 become heated.

This generated heat is transferred to the fusible alloy 2 via elements IA and IB, which heats and melts the fusible alloy 2, and the element I
A and IB are glued together.

At this time, the temperature distribution in each part is as shown in Figure 5.
Elements IA and IB also have appropriate temperatures. Therefore, adhesion is also ensured. Thereafter, the upper metal body 3B is pulled up, and as shown in FIG. 4, a fusible alloy 2 is temporarily attached to the lower surface of the upper metal body 3B, and an element IC heated below the solder melting temperature is attached thereto.

Further, the upper heating coil 4B is moved to a height corresponding to the position of the upper metal body 3B (indicated by a dashed line in FIG. 4) when three elements are stacked. In this way, while preparing for the next bonding, the element IB, which was heated above the optimum temperature for soldering during the first bonding operation, is cooled down, and when the temperature of its upper surface has decreased to near the optimum temperature for soldering, presser metal 8 is pushed down. Element IC and the fusible alloy 2 on its lower surface are pressed onto the upper surface of element IB.

At the same time, high frequency current is passed only to the upper heating coil 4B.
As a result, the upper metal body 3B is heated by induction heating,
The generated heat is transmitted to the fusible alloy 2 via the element IC. The fusible alloy 2 is heated and melted by conduction heat and residual heat of the element IB. In this case as well, the temperature distribution on the top surface of the upper metal body 3B, element IC, fusible alloy 2, and element IB is approximately the same as the distribution state shown in FIG. (Fig. 2) did not occur, and a good adhesion state was obtained. In the above explanation, we explained the bonding of three devices, but in the case of four or more devices, the bonding process of the device IC (2
The second finishing step) will be repeated one after another.

As described above, according to the present invention, heating is performed from room temperature in the first bonding process, but in the subsequent bonding process, child heat during standby and residual heat from the previous bonding are used.
10 minutes, and subsequent gluing takes less than 5 minutes, and although several pieces can be glued at the same time in a heating oven,
Work efficiency is significantly improved compared to methods that require 1 to 2 hours for one operation. Furthermore, it is possible to flexibly deal with changes in the number of laminated layers, and the adhesion is reliable.

[Brief explanation of drawings]

Fig. 1 is a schematic layout diagram for explaining an example of a bonding method using induction heating, Fig. 2 is a diagram showing a bonding surface with poor adhesion, and Figs. 3 and 4 are diagrams showing the method of the present invention. FIG. 5 is a schematic layout configuration diagram showing an embodiment, and a temperature distribution diagram showing the temperature of the bonded portion and its vicinity during bonding. IA~IC... Element, 2... Fusible alloy, 3
A and 38...lower and upper metal bodies, 4A and 4B...lower and upper heating coils, 5...
...High frequency power supply, 7...Alloy, 8...
Oshikin. Section 1 Figure Section 2 Key 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 Two lightning arrester elements made of non-linear resistors mainly composed of zinc oxide are laminated with a fusible alloy sandwiched between the surfaces to be bonded, and a metal that can be easily heated by induction is attached to both end surfaces. a first bonding step in which the metal bodies are brought into contact with each other, and the heat generated by induction heating of both metal bodies is transferred to the fusible alloy through the element to heat and melt the fusible alloy to bond both elements;
After this bonding process is completed, one metal body is separated from the element, a fusible alloy is temporarily attached to it, and a preheated third element is attached, and the heating coil corresponding to the moved metal body is repositioned. When the temperature of the bonding surface of the first bonded element with the third element drops to near the melting temperature of the fusible alloy, the metal body to which the third element is attached is pressed against the element. A second bonding step is performed in which the metal body is moved in the direction to pressurize the element, and at the same time, only the metal body is heated by induction, and the fusible alloy is heated and melted by conduction of the generated heat. A method for bonding elements for a lightning arrester, characterized by repeating a second bonding step.