JPS6012688A - Method of producing airtight insulated terminal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an airtight insulated terminal, and more particularly, to a method for manufacturing an airtight insulated terminal that is installed through a wall of a metal airtight container. The present invention relates to a method of manufacturing an airtight insulated terminal used in a forced cooling type rectifying device, etc., in which a rectifying element made of a semiconductor for large currents that generates heat is immersed in a cooling medium filled with a rectifier.

Recently, the above-mentioned rectifying devices are often installed in vehicles, and in that case, there is a strong demand for the airtight insulated terminals, which are related to the overall weight, to be lighter and smaller. It is also required to be stable against vibrations, etc.

Conventionally, the airtight terminals that have been commonly used include those that use rubber, glass, or porcelain as airtight adhesives and electrical insulators, but those that use rubber have poor heat resistance and deteriorate over time. Furthermore, there are problems with corrosion resistance against cooling media, etc., and those made of glass or porcelain have poor vibration and shock resistance and have a high risk of breakage, so they are rarely used in rectifiers installed in vehicles. Mostly unused.

As mentioned above, the conventional airtight insulated terminal has an unavoidable fatal flaw.

It is made from a mixed powder of vitreous powder and mica powder as a raw material that has completely completed the above-mentioned fatal defects, namely heat resistance properties, aging properties, corrosion resistance against cooling media, and vibration and shock resistance, and maintains extremely excellent properties. The present inventor has developed an insulating material obtained by heating the vitreous material to a temperature at which it flows under pressure and then press-molding it under the heated state, using a so-called glass-mica plastic material as an airtight sealant and an insulating material. It was proposed by L.

However, in order to maintain the above characteristics with the above airtight insulated terminal,
The current-carrying conductor (hereinafter referred to as the current-carrying electrode) is limited to those with a large diameter, for example, those with a diameter of /2 Omr or larger, and as the reverse electrode diameter becomes smaller, the airtightness property decreases, When it becomes small to about 2 to lIma, its airtightness is extremely degraded, and only products that are practically unusable can be manufactured. This was an unavoidable situation due to the conventional manufacturing method.

Prior to explaining the present invention, in order to facilitate understanding, a conventional manufacturing method for a reverse electrode with a large diameter will be explained.

FIG. 1 shows the structure of a conventional airtight insulated terminal with a large reverse electrode diameter. In the figure, the rod-shaped reverse electrode / is made of a material with good electrical conductivity, such as copper or copper alloy, and the metal tube, which is installed by penetrating the wall of the metal airtight container, has high mechanical strength. , and is made of a metal with as high a coefficient of thermal expansion and contraction as possible, and stainless steel or the like is generally used. The insulating member 3 is made of a glass-mica plastic body made of a mixed powder of vitreous powder and mica powder, heated to a temperature at which the vitreous material can flow under pressure, and then pressure-molded in the heated state. There is.

Next, a conventional manufacturing method of the above-mentioned hermetic insulated terminal will be explained with reference to FIG. In the figure, a four part 3-/ is formed on the left side of the wall of the divided structure in which a receiver 7 can be accommodated at the bottom. The wall S is fastened by the frame base.

Receiver 7 has an insertion hole into which 1/rl −1,=l is inserted? -/ and a cooling water channel 7-2 are formed. Cooling water channel 7
-2 has pipes (not shown) at both ends that allow water to be injected and drained. Cooling water channel g-
A water injection ring and a pipe (not shown) capable of draining water are attached to both ends of the cooling water channel g-/. The above-mentioned mold is used for molding.

The raw material for the insulating member 3 is a mixture of vitreous powder and mica powder, which is made wet by adding water to it, and then cold-pressed using another mold (not shown) to conduct electricity in the center. (It is used as a cylindrical preformed body with a hole through which the shell can be passed through.)

In the molding, the wall j1, frame 6 and receiver 7 are assembled in a mold as shown in FIG. 1(a) and heated to a predetermined temperature. In addition, the reverse electrode, the metal tube, and the preform are also heated to a predetermined temperature. When these heatings are completed, the counter electrode l
Insert hole? -/, the metal cylinder is loaded into the wall S, and the preform G is loaded onto the metal cylinder. The state at this time is shown in FIG. 2(a). Next, the pressurized metal g is placed on the preformed body q, and the pressurized metal g is pressurized by a pressure molding machine, and the preformed body D is made to flow into the gap between the metal cylinder and the counter electrode l. Press fit and fill. The state at this time is shown in FIG. 1(b). When the pressurization is completed, water is immediately passed through the cooling channels 7-, g-/ provided in the receiving metal 7 and the pressurizing metal g. During this time, continue applying pressure. When the temperature of the molded insulating member 3 reaches a temperature below the glass transition temperature and solidifies, the water flow is stopped, and after depressurizing, the mold is separated. +%t, and take out the molded product.

In the above manufacturing process, by passing water through the cooling channel of the receiving metal 7 and the pressurizing metal g, which is performed at the same time as the pressurizing process is completed,
The receiving metal 7 and the pressurizing metal 3 are rapidly cooled.

Since the counter electrode l in contact with this receiver 7 and the pressurizing metal plate is made of copper or copper alloy with good thermal conductivity,
This counter electrode is cooled preferentially to other parts, its volume contracts, and its diameter becomes thinner. That's why it's so good! A gap is generated at the contact surface with the molded insulating part 3 on the outer peripheral surface of J, pole/, but on the other hand, the molded t3 edge member 3 is in a flowable state at this point, and Since the pressurizing force is applied from above, this gap is filled with the insulating member 3, and this gap does not actually occur. Next, insulation member 3
is cooled and solidified by the reverse electrode l. At this time, as will be explained in detail later, the metal cylinder on the outer periphery maintains a high temperature because the heating temperature is higher than that of the insulator 3.
When the insulating member 3 is in a solidified state, it is cooled from a higher temperature, so the volumetric contraction becomes a tightening pressure on the insulating member 3, and as a result, a phenomenon equivalent to shrink fitting occurs.
Airtightness is ensured.

According to the conventional manufacturing method described above, in the case of a product with a large diameter conductor, a product with extremely excellent airtightness can be obtained, as is clear from the above explanation, but as the diameter of the conductor becomes smaller, The air-tightness property deteriorated, especially when the diameter became 2 to +y+m, the property deteriorated extremely, and only a product that could not be used was obtained. The reason for this will be explained below.

In the above manufacturing method, the essential conditions that must be realized are that the temperature of the opposite electrode is lowered in priority to the temperature of the molded insulating member 3, and that the temperature of the metal cylinder is lowered by reducing the temperature of the insulating member 3. It is to be later than that of . In order to realize these conditions, after the completion of pressure forming, cooling channels for the support metal 7 and the pressure metal 3 are installed. -2,g-/, but before molding, a temperature difference is established when heating the reverse electrode 11 metal cylinder 2, preform body DA, and mold to ensure the above conditions. There is.

Each heating temperature will be explained below. First, regarding the heating temperature of the counter electrode, it is preferable that it be as low as possible, but in reality it needs to be at or slightly higher than the glassy transition temperature. This is because if the temperature is lower than this, when the heated preform comes into contact with the glass, the glass of the preform will solidify and form a low-density layer on the surface. Since this is the worst case in terms of airtightness, it is necessary to heat it to the above temperature. Next, regarding the heating temperature of the metal tube 2, although higher is preferable in concept, it is governed by the mechanical strength at high temperatures. As shown in FIG. 2(a), a gap 10 exists between the outer periphery of the metal cylinder and the inner wall surface of the wall body 5 during loading, but in FIG. is deformed, the above-mentioned void lθ disappears,
Completely adhere.

When heating a metal cylinder λ, deformation in the pressurizing direction becomes a problem, and although it varies depending on the material used, in reality 6θ0-A! ;
The limit is 0°C. Next, regarding the heating temperature of the preform, increasing the temperature is effective in increasing the temperature of the metal cylinder after filling is completed and slowing down the cooling rate.
At the same time, the temperature of the counter electrode 1 will also rise, leading to
I don't want to have any effect on cooling, which is the highest priority.

Therefore, it is extremely difficult to set the temperature, and the temperature must be set so that it will flow sufficiently when pressurized. Finally, as for the heating temperature of the mold, it is desirable to set it as high as possible in order to slow down the temperature drop rate of the fully curved cylinder, but the upper limit is 50°C in relation to mechanical strength.

The diameter of the reverse electrode l of the airtight insulated terminal to be molded is /j ~ λOV
a or larger, the shape of the metal cylinder will inevitably become larger and the wall thickness will become thicker. Also, the mold will also naturally become larger and the heat capacity of each part will be large. The effect of cooling the reverse electrode 1 with the highest priority by passing water through the cooling channel is completely obtained, the above-mentioned essential conditions are completely satisfied, and an airtight insulated terminal with high airtightness retention properties is obtained.

By the way, if a reverse electrode l with a small diameter is manufactured using the conventional molding method described above, the main reason why a product that maintains a certain airtight property cannot be obtained is that the above essential conditions are violated. The reason for this is thought to be a lack of heat capacity due to the downsizing of the metal cylinder 2 and the mold due to the reduction in the diameter of the reverse electrode.

This invention was made with attention to the above points, and completely eliminates the fatal flaw of the conventional manufacturing method, namely, the small diameter of the reverse electrode, which deteriorates its airtightness. To provide a manufacturing method that maintains various characteristics of a large reverse electrode obtained by conventional manufacturing methods and provides a hermetic insulated terminal having perfect airtightness regardless of the reverse electrode diameter. The purpose is to

Another object of the present invention is to place a reverse electrode in the center of a metal cylinder, and between the two, a mixed powder of vitreous powder and mica powder is heated to a temperature at which the vitreous material flows under pressure. , a method for manufacturing an airtight insulated terminal in which an insulating member made of a glass-mica plastic body press-molded in a heated state is interposed, in which a preformed body formed into a cylindrical shape with a metal tube, a reverse electrode, and raw material powder is placed on top. A wall body with a split structure that can house a receiver that can be loaded and has a cooling water channel and a reverse electrode insertion hole in the lower part, and a frame body that tightens this wall body;
A pressurized metal mold with a through hole for fitting the reverse electrode in the center is used, and the metal tube has a bottom groove on the bottom that touches the wall when loading, and a screw groove or annular groove on the facing outer peripheral surface. Heat the reverse electrode, metal cylinder, preform, and mold to a predetermined temperature, insert the reverse electrode into the insertion hole I of the holder, and place the metal cylinder and preform on the upper part of the wall. The process of loading the body and placing the pressurized metal on the preform, pressurizes the pressurized metal, press-fits the preform into the gap between the counter electrode and the metal cylinder, and fills the gap between the counter electrode and the metal cylinder, and creates a high-density insulating member. and, once the pressure is completed, the process of rapidly cooling the reverse electrode by passing water through the receiver while continuing the pressure, and the step of rapidly cooling the reverse electrode until the temperature of the insulating member reaches a temperature below the glass transition temperature. It is an object of the present invention to provide a method for manufacturing an airtight insulated terminal, which comprises a step of disassembling the mold and taking out the molded product at the time when the mold is removed.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. In the figure, the same reference numerals as in FIG. 2 indicate the same parts. In the figure, the metal cylinder 2 has an outer circumferential groove 1, which is a screw groove or an annular groove, on its outer circumferential surface, and a bottom groove 2, which is in contact with the wall S. In the mold, a pressurizing metal/g without cooling channels is used.

The molding procedure is the same as the conventional method: heat the reverse electrode/, the metal tube 7.2 preform, and the mold to a predetermined temperature, and insert the reverse electrode/ into the insertion hole 7-/ of the receiver 7. Then, the metal tube 2 and the preform 2 are loaded into the wall 5. The state at this time is shown in FIG. 3(a). Next, the pressurized gold/g is placed on the preformed body DA, and the pressurized gold/g is pressurized by the pressure molding machine, and the preformed body G is made to flow and the gap between the reverse electrode 1 and the metal tube 12 is made to flow. Press fit and fill. The state at this time is shown in FIG. 3 (1). Immediately after the pressurized filling is completed, water is passed through the cooling water channel Cuco provided in the receiver 7.

Continue pressurizing during this time. When the temperature of the molded insulating member 3 reaches a temperature below the glass transition temperature and solidifies, the water flow is stopped, and after depressurization, the mold is disassembled and the molded product is taken out, and the outer circumferential groove /, 2- Perform necessary machining such as removing / and bottom groove /2-2 to finish the product.

According to the above-described manufacturing method of the present invention, when the pressurized filling process is completed, the receiver 7 is rapidly cooled by water flow, so the reverse electrode l is cooled preferentially to other parts. It becomes like this. Moreover, since the pressurized gold/g does not have a cooling channel and is not directly cooled, it has no effect of rapidly cooling the reverse electrode l, but at the same time, the molded insulating member 3 in contact with it is also not rapidly cooled, and the reverse electrode l The insulating member 3 is continuously filled into the space on the outer circumferential surface created by the dimensional shrinkage caused by rapid cooling by the receiving metal 7. On the other hand, the metal cylinder has an outer circumferential groove on its outer circumferential surface and a bottom groove on its bottom, and is deformed during molding and comes into contact with the wall S, but the contact area is extremely large. As a result, the cooling rate due to the low-temperature wall body S becomes extremely slow. Due to the above-mentioned series of relationships, it is possible to lower the temperature of the reverse electrode with priority to lowering the temperature of the molded insulating member 3, which is an essential condition in the manufacturing conditions of this type of airtight insulated terminal, and to lower the temperature of the metal tube l. This ensures that the temperature drop of the insulating member 3 is slower than that of the insulating member 3.

For example, when copper chrome with a diameter + mrn is used for the current-carrying rod l and the conventional manufacturing method is followed, a test using a helium leak detector shows that the amount of leakage is s x /
O-'atm cc/sec (y) Only the product was obtained, but the product according to the manufacturing method of this invention is t x
Indicates the leakage amount of lo '-11 atmcc/sea,
The effect was clearly demonstrated.

As described above, according to the manufacturing method of the present invention, it is possible to easily obtain an airtight insulated terminal with high airtightness retention properties even in the case of a small conducting electrode diameter that could not be obtained using conventional manufacturing methods. The hermetic insulated terminal can be made smaller, and the rectifier itself can be made lighter and smaller, so its technical and practical effects are extremely large.

In the above explanation, the target is a forced cooling type rectifier, but it is not limited to the manufacture of airtight insulated terminals for this type of rectifier. Not only can it be implemented in the production of insulated terminals, but its applications are extremely wide-ranging.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional airtight insulated terminal, and Figure 1 is a half-cut vertical cross-sectional view showing the conventional manufacturing method. The state after pressure molding is completed. FIG. 3 is a half-cut vertical sectional view showing the manufacturing method according to the present invention, and FIG. 3(a) shows the state immediately before pressure molding.
b) shows the state after completion of pressure molding. In the figure, l is a current-carrying rod, 3 is an insulating member, da is a preformed body, and S
is a wall body, 6 is a frame body, 7 is a receiver, 7-7 is an insertion hole, 7-2
9 is a cooling channel, 9 is a gap, 12 is a metal cylinder, /2-/ is an outer circumferential groove, and l course is a bottom groove. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa 3 (G) (b)

Claims (1)

[Claims] A rod-shaped reverse electrode is placed in the center of the metal cylinder, and between the two,
An airtight insulated terminal made of a mixed powder of vitreous powder and mica powder, heated to a temperature at which the vitreous powder flows under pressure, and interposed with an insulating member made of a glass-mica plastic body which is pressure-molded in the heated state. In the manufacturing method, the wall body has a split structure in which an upper part can house the metal cylinder, the reverse electrode, and raw material powder for the insulating member, and a lower part can house a receiver having a cooling water channel and an insertion hole for the reverse electrode. and a frame body for tightening this wall body, and a pressurizing metal having a through hole in the center for fitting the above-mentioned reverse electrode. a step of heating the reverse electrode, the metal tube, the preformed body of the raw material powder previously formed into a plate shape having a through hole in the center, and the mold to a predetermined temperature using a cylinder, and the heating state inserting the reverse electrode into the insertion hole of the receiving metal and loading the metal tube and the preform onto the upper part of the wall; and placing the pressurizing metal onto the upper part of the preform. a step of pressurizing the pressurized metal to press-fit the preform into the gap between the counter electrode and the metal cylinder, and when this filling is completed, pressurizing the metal cylinder while continuing to press the metal cylinder; a step of rapidly cooling the reverse electrode by passing water through the insulating member, and a step of disassembling the mold and taking out the molded product when the temperature of the filled and molded insulating member reaches a temperature equal to or lower than the transition temperature of the glassy substance. and a step of removing the outer circumferential groove and the bottom groove of the metal tube by machining to finish the product.