JPS6346539B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airtight insulated terminal used, for example, when making an electrical connection between an electrical device housed in a metal airtight container and the outside. Suitable for use in forced cooling type rectifiers filled with a liquid compound as a cooling medium and immersed in heat-generating semiconductor rectifiers for large currents, etc., and generally used in other control or measurement devices. The present invention relates to an airtight insulated terminal (hereinafter referred to as a "multipolar terminal") having a plurality of terminal conductors for current carrying.

The characteristics required for this type of multi-pole terminal are that it has high heat resistance, does not deteriorate over time, maintains extremely high airtightness (watertightness), has high corrosion resistance against cooling media, and has high thermal and mechanical impact strength. In particular, this type Since the insulation properties between the conductive electrodes may deteriorate due to contamination during use, high creepage insulation properties are strongly required. This requires long creepage insulation lengths. In addition, it goes without saying that it is easy to attach to equipment, etc., and that it is inexpensive.

Traditionally known multi-pole terminals include those that use synthetic resin, rubber, glass, or porcelain as electrical insulators and airtight sealing materials, but those that use synthetic resin or rubber are heat-resistant. It has poor properties and deteriorates over time, its airtightness is unreliable, and there are many problems with its corrosion resistance against cooling media. Glass or porcelain materials maintain perfect performance in terms of airtightness and corrosion resistance, but they have poor thermal and mechanical impact resistance, and therefore, when used in rectifiers installed in vehicles etc., vibrations may occur. They have a fatal flaw in that they can be damaged, making them impossible to use.

A multi-electrode terminal that maintains the satisfactory characteristics as described above has not been known so far, but fortunately there is a hermetically insulated terminal with a single conducting electrode (hereinafter referred to as a "single-electrode terminal").
Since a material satisfying the above-mentioned characteristics described in detail below can be obtained, the required number of poles was used. In this case, as the number of uses increases, it is not only difficult to install it, but also the installation area increases, the size of the device itself becomes larger than necessary, and manufacturing costs inevitably increase. It was hot. The single-pole terminal with stable characteristics is shown in cross-section in FIG.

In FIG. 1, reference numeral 1 denotes a base body having a through hole 101, and is made of a metal such as iron or stainless steel that can withstand heating of about 600°C.
It is attached to the necessary part of the container wall by, for example, welding, screwing, or other methods. Reference numeral 2 designates a terminal body located at the center of the through hole 101 in the center of the base 1, and is generally made of a good electrical conductor such as iron, titanium, or a copper alloy, such as copper chrome. 3 is an insulating material made of a mixed powder of glass powder and mica powder. This raw material is heated to a temperature where the glass becomes soft and flows under pressure, and the through hole 101 and the conducting electrode 2 are formed by pressure molding in the heated state. It is a glass-mica plastic body that is sealed and fixed.

The prior art single-pole terminal configured as described above has the characteristics required for this type of terminal, namely, heat resistance and no aging, airtightness, corrosion resistance against refrigerants, resistance to cold and thermal shock, and mechanical shock resistance. This is an extremely excellent product that maintains all insulation properties including creepage insulation.

The present inventors completed the present invention as a result of extensive research in order to obtain a multi-pole terminal that maintains characteristics equivalent to the single-pole terminal shown in FIG. 1 above. That is, an object of the present invention is to provide a compact multi-pole insulated terminal that has all the characteristics of the single-pole terminal according to the prior art, including creeping insulation resistance characteristics.

FIG. 2 shows the structure of a multipolar airtight insulated terminal according to an embodiment of the present invention. In the figure, 2a is a conducting electrode arranged at the center of the terminal, 2b is a conducting electrode arranged outside the center, and these conducting electrodes 2 are connected to the through hole 1.
01, and the insulator 3 fills the space between the through hole 101 and the conducting electrode 2, and the upper surface 103 and the lower surface 1 of the base 1.
A creeping insulating part 31 is formed to cover the protruding part 21 from the through hole 101 of the conducting electrode 2 and separately surround the circumferential surface of the protruding part 21 from the through hole 101 of the conducting electrode 2.

Next, regarding the constituent metal materials of the conducting electrode 2 and the base 1, it is assumed that they can withstand heating at 600°C and maintain mechanical strength. becomes the standard. It can be safely assumed that the transition temperature of this glass-mica plastic body is equivalent to that of the raw material glass. In addition, its coefficient of thermal expansion is largely controlled by the raw material glass, and its value is 8×12
About ×10 ^-6 can be obtained. The base 1 is made of a material whose coefficient of thermal expansion is larger than that of the glass/mica plastic body. Specifically, stainless steel is suitable. In addition, the coefficient of thermal expansion of the conducting electrode is that of glass.
Ideally, it should be smaller than that of the mica plastic body,
For example, titanium is suitable. However, similar or larger materials such as iron and its alloys, or copper and its alloys, such as copper chromium, can also be used. Since this relationship is closely related to the manufacturing method, it will be explained separately, and the relationship between structure and characteristics will be explained first. The multi-pole terminal according to the present invention has the same number of through holes 10 as the number of conductive electrodes 2 in the base 1.
1 is provided, and a conducting electrode 2 is located in the center thereof, and the conducting electrode 2 is inserted into the through hole 101 due to contraction of the base 1.
The glass-mica plastic body 3 existing in the space between the inner wall of the terminal and the conducting electrode 2 applies uniform pressure to the entire surface, and a state equivalent to that of the single-pole terminal shown in Fig. 1 appears. This prevents the airtightness from deteriorating due to repeated temperature rises and falls.
In addition, it maintains all the characteristics of the single-electrode terminal described above in terms of maintaining perfect characteristics against cold, heat and mechanical shock. The feature of this invention is that creeping insulation parts 31 each independently surround the protruding part 21 of the conducting electrode 2 with the connecting part 32 as the root part.
exists. Due to the presence of the creeping insulation portion 31, the creeping insulation characteristics which conventional multi-pole terminals could not maintain are completely maintained, and the fatal defects of the conventional products are completely eliminated.

Next, a typical manufacturing method will be explained with reference to FIG. In the figure, 5 is a molding frame, 6 is a receiving metal fitting, and a holding hole 61 can hold the conducting electrodes 2a, 2b upright.
and a conical space 63 that can form the support portion 62 of the base 5 and the tapered creeping insulation portion 31.
is provided at the upper part of the holding hole 61. 7 is a pressurized metal having a penetration hole 71 that can pass through the conductive electrodes 2a and 2b, and a conical space 72 that can form the creeping insulation part 31. The mold is made up of the above three parts. Note that each of the mold component parts is provided with a heating device (not shown), so that it can be heated to a desired temperature.

In manufacturing, normally, a fixed platen 8, a first driving part 9 disposed in the center of a through hole 81 provided in the fixed platen and driven up and down, and opposing to this first driving part 9 are used. A pressure molding machine having a second driving section 10 disposed at the top of the figure and driven vertically is used.
The forming frame 5 is fixed to a fixed platen 8 via a jig (not shown). The receiving fitting 6 is fixed to the lower drive part 9, and the pressurizing metal 7 is fixed to the upper drive part 10 by jigs (not shown), respectively.

Prepare the base 1. The material used for these metal fittings is one that has a coefficient of thermal expansion that is lower than the transition temperature of the vitreous material of the glass-mica plastic body. Specifically, iron and its alloys, such as stainless steel, can be suitably used, and those with high-temperature strength comparable to iron are generally preferred.

Next, a preformed body 15 is prepared. This preformed body 15 is formed into a predetermined shape by pressing a mixed powder of vitreous powder and mica powder at room temperature using another press die (not shown). Next, the conducting electrodes 2a, 2b
However, the material is not particularly limited and may include iron, titanium,
Copper alloys such as copper chrome can be used.
In general, a smaller coefficient of thermal expansion is desirable, but it can be increased significantly depending on the molding conditions.

An example of actual production of a multi-electrode terminal will be explained in detail according to the steps. First, the preform 15 is created.
Glassy contains PbO1.0, B ₂ O ₃ 0.4, SiO ₂ 0.4,
The raw material is a mixture of 55 wt% powder of AlF ₃ 0.2 molar ratio composition crushed into 200 meshes, 45 wt% of synthetic gold fluorine mica powder of 60 to 100 meshes, and 5 wt% water added to make it wet. Weigh out the grams;
Using another mold (not shown), by cold pressing, the outer diameter was 46mmφ, the height was 40mm, and the center and
A disk with 6 through holes of 5 mmφ located at equal distances on the circumference of mmφ was made, and it was placed in a dryer at 120℃ for 2 hours.
After holding for a while and removing moisture, the creation was completed.

Next, regarding base 1, it is made of stainless steel and has an outer diameter of
A disk having a diameter of 50 mm, a height of 15 mm, and six through holes of 7 mm diameter located equidistantly on the center and the circumference of 30 mm diameter was used. In addition, the conducting electrode is made of titanium material with an outer diameter
We prepared 7 pieces of 2.6mmφ with lengths starting from the shortest 115mm, each length increased by 1.5mm to the longest 124mm, each with a 1mm radius on one end. The mold holds the receiving metal fitting 6 in the position shown in FIG.
Heat to 300 °C using each heating device. Base 1
The preform 15 is heated to 550°C and the preform 15 is heated to 600°C using another electric furnace (not shown). When each heating is completed, the pressurizing metal 7 is first raised as shown in FIG. 3A to create a space between it and the frame 5.
Next, the receiver 6 is raised until its upper surface is at the same position as the upper surface of the frame 5, and the conductive electrodes 2a, 2b are inserted into the holding holes 61 of the receiver 6 at room temperature. Next, the base body 1 is inserted onto the receiving metal fitting 6 with the conductive electrodes 2a and 2b inserted into the through holes 101 thereof, and subsequently the preform 15 is inserted onto the base body 1 in the same manner. When the insertion is completed, the receiving metal fitting 6 is lowered to its original position, and the pressurizing metal fitting 7 is then lowered to insert the conductive electrode 2 into the penetration hole 71.
The preformed body 15 is pressurized with a total pressure of 40 tons so that the parts a and 2b enter into the state shown in FIG. 3B. The entire molded product is cooled to 320° C., and after the pressurizing metal 7 is raised, the receiving metal fitting 6 is raised to take out the molded product and the molding is completed.

In the above manufacturing example, matters directly related to molding will be explained. First, when pressure molding is completed, conductive electrode 2
It is an essential condition that a and 2b penetrate smoothly into the penetration hole 71 of the pressurizing metal 7. As a method to satisfy this condition, the holding hole 61 of the receiving metal fitting 6
The conductive electrodes 2a and 2b are held upright and their mutual spacing is maintained at the same distance, and when the pressurizing metal 7 is lowered, the penetration hole 71
It is important to have a function that allows the conductive electrodes 2a, 2b to penetrate smoothly. Further, providing a difference in length between the conducting electrodes 2a and 2b and making the upper end portions curved is a means for ensuring reliable insertion. Furthermore, when the presser metal 7 descends during pressure molding, the tip 73 of the presser metal 7 first touches the preform 15.
The preform 15 then deforms and fills the space 72 of the press metal 7. Next, the preform 15 passes through the through hole 101 of the base 1 and flows into the space 63 of the receiving metal fitting 6. During this flow, the conductive electrodes 2a and 2b come to penetrate into the penetration hole 71 of the pressurized metal 7. At this point, the conductive electrodes 2a, 2b are under pressure from the outer periphery due to the preform 15 filling the space 72, so that it becomes difficult to penetrate into the penetration hole 71. As a means to avoid this difficulty, the penetration hole 7 of the pressurizing metal 7 is
It is an effective means to make the entrance 74 of No. 1 a curved surface.

Next, regarding the shape of the preform 15, in the present invention, by heating the preform 15, the viscosity of the glassy substance contained therein is lowered, and the preform 15 itself maintains fluidity, thereby achieving the desired shape. Since the preform 15 is characterized by pressure molding into a shape, the shape of the preform 15 is a flat plate. More specifically, if the temperature drop is large between inserting the preform into the mold and the pressurizing process during molding, fluidity will be reduced and uniform molding will become difficult. To avoid this phenomenon, when inserting, the inner wall of the frame 5 and the conducting electrode 2a,
The necessary condition is to avoid contact with 2b.
For this purpose, it is important to make the outer diameter smaller than the inner diameter of the frame 5 and the inner diameter of the hole larger than the outer diameter of the conductive electrodes 2a, 2b. In addition, in this manufacturing example, a so-called lead-based glass containing lead oxide is used as the glass constituting the preform 15, but the composition is not limited to this in any way; for example, commercially available Lead-free enamel glazes may be used. Furthermore, the mica powder used is mixed with glass and heated to over 600°C, so it decomposes at this temperature and cannot be used. That is, natural mica cannot be used and is limited to synthetic mica, and synthetic gold fluorine mica is an optimal example. Next, regarding the insulator 3 formed by heating and pressurizing, the thermal expansion coefficient (in this case, it is the thermal contraction coefficient, but it can be considered equivalent) is lower than the transition temperature of the vitreous material used for the base material 1. It is essential that it be smaller than that of the material. The greatest feature of the multi-electrode terminal of this invention is that it maintains a complete airtight property, which is achieved through the insulator 3 between the conductive electrodes 2a and 2b contained in the base 1 existing on the outer periphery. This is achieved by strongly tightening. Therefore, the difference in thermal expansion coefficient is an important factor. Note that the conducting electrode 2a,
Regarding the relationship of thermal expansion coefficient with 2b, it is ideal that the conductive electrodes 2a and 2b are smaller than the insulator 3 for the same reason as above, but even if they are the same or somewhat larger, Effects can be obtained. The reason for this is that during molding, the conducting electrodes 2a and 2b are inserted into the mold at room temperature, so the outer periphery is filled with the insulating material 3 under conditions of low temperature rise, and the absolute amount of shrinkage is small. be.

Next, regarding the relationship between the heating temperatures of the mold, the base 1, the conductive electrodes 2a and 2b, and the preform 15, the temperature of the mold is closely related to the transition temperature of the raw glass. That is, if the temperature is too high than the transposition temperature, the insulator 3 may stick to the mold during pressure molding, making it difficult to release from the mold.If it is too low, there is a risk of forming a low-density part, It is desirable to keep it as low as possible. Note that it is essential that the temperature during depressurized decomposition be lower than the transposition temperature, so it is important to take this point into consideration when setting the temperature. Base 1
This temperature is closely related to the heating temperature of the preformed body 15, which will be described later. In the manufacturing process, the preform 15 is inserted onto the upper surface of the base 1 and makes surface contact with it, so if the temperature is low, the preform 15
A higher value is preferable because it cools the material, increases its viscosity, and worsens the fluidity during pressure molding, but if it is too high, its mechanical strength decreases and there is a risk of deformation, so it is not desirable. In reality, it is desirable that the heating temperature be somewhat lower than the heating temperature of the preform 15.

Next, regarding the heating temperature of the conducting electrodes 2a and 2b, they do not come into direct contact with the preform 15 during the insertion process of molding, and the insulator 3 is press-fitted into the outer periphery for an extremely short time. Since the heat capacity is extremely small, heating is not required because it hardly lowers the temperature of the preform 15 and reduces the fluidity, but rather, as mentioned above, it is related to the absolute amount of shrinkage. A lower value is desirable from the perspective of ensuring airtightness, and it is also easier to operate.
It is best to use it without heating it as in the production example. However, if the conducting electrode is thick, it is desirable to heat it appropriately as necessary.

Next, the heating temperature of the preform 15 is directly related to the softening temperature of the glass used, and may be 800°C to 850°C when enamel glaze is used.

Next is the blending ratio of glassy powder and mica powder, which is an important factor as it relates to properties and molding conditions. If the blending ratio of glass increases, the fluidity during pressure molding will improve and molding will become easier, but on the other hand, defects such as a decrease in mechanical strength and generation of harshness will appear, and if it is too low, There is a tendency that molding becomes difficult, so in reality, a range of 25 to 50% vitreous content in terms of volume ratio is suitable.

Next is the relationship between the hole diameter of the through hole 101, and the relationship with the outer diameter of the conducting electrodes 2a and 2b. The resistance increases, and at the same time, the fluidity also improves, making it easier to increase the density of the lower creeping insulation portion 31. Note that the difference in diameter has almost no effect on airtightness. Rather, what has a large influence is the distance relationship between adjacent through holes 101. That is,
If the distance is short, the airtightness may deteriorate due to factors related to the tightening force. In fact, if the shortest distance between adjacent through holes is approximately the same as the diameter of the through hole 101, its airtightness can be completely ensured.

Next, regarding the shape of the upper and lower creeping insulation parts 31, in the example, the upper and lower parts have the same size and shape, but
There is no problem in providing different lengths depending on usage environmental conditions. Naturally, the longer the length, the more difficult it is to mold. Furthermore, by making the shape conical, with the diameter becoming narrower toward the tip, demolding after molding is completed becomes easier.

The product that has been molded as described above can be machined if necessary, and manufacturing is completed through this process.

The multi-pole terminal of the present invention, unlike conventionally used rubber, glass or porcelain insulators, completely maintains corrosion resistance, airtightness, thermal and mechanical impact strength, and It completely maintains creeping insulation resistance properties that were not possible with products made of glass/mica plastic, and has completely eliminated the defects of conventional products. Instead of using multiple devices in parallel, it is now possible to achieve the purpose by using a single device, which not only makes the device itself smaller and lighter, but also greatly simplifies the manufacturing process, which is extremely effective. big.

The base body 1 is also processed by simply providing the necessary number of through-holes, and its dimensions require little precision, are inexpensive, and have great secondary effects.

In addition, in explaining the present invention, the subject matter is an airtight insulated terminal for a rectifier that uses liquid as a medium, but the application is not limited to this aspect, and the invention is not limited to this. It can be used for food or metal containers filled with high-pressure gas, and its uses are extremely wide.

As described above, the multi-pole terminal according to the present invention has high performance and can be produced at low cost, and its effects are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure of a conventional single-pole insulated terminal, Fig. 2 is a sectional view showing the structure of a multi-polar insulated terminal according to an embodiment of the present invention, and Fig. 2a is a cross-sectional view;
FIG. 2b is a longitudinal sectional view. FIG. 3 is a sectional view showing an example of the method for manufacturing a multi-electrode terminal according to the present invention, where A shows the state immediately before pressure molding, and B shows the state after pressure molding is completed. In the figure, 1 is the base, 2, 2a, 2b are terminal conductors,
21 is a protruding portion, 3 is an insulator, and 31 is a creeping insulation portion. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A base body having a plurality of through-holes, a plurality of terminal conductors provided through each of the plurality of through-holes,
A creeping insulator is formed which seals and fixes the through hole and the terminal conductor, surrounds the peripheral surface of each protrusion of the terminal conductor from the through hole, and covers both upper and lower surfaces of the base at the base thereof. An insulator made of a glass mica plastic body is provided, and the coefficient of thermal expansion of the insulator is lower than the coefficient of thermal expansion of the base body at a temperature below the transition temperature of the glassy substance contained in the insulator. Multi-pole insulated terminal.