JPS6342379B2 - - 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, and a method for manufacturing the same. It is suitable for use in forced cooling type rectifiers in which a liquid compound such as fluorocarbon is filled as a cooling medium and a rectifying element that generates heat, for example made of a semiconductor for large currents, is immersed in the liquid compound, and other control or measurement equipment. Hermetically insulated terminals with multiple current-carrying terminal conductors that can be generally used for applications such as terminals (hereinafter referred to as "multi-pole terminals")
and its manufacturing method.

Conventionally, multi-pole terminals commonly used have used rubber, glass, or porcelain as airtight sealants and electrical insulators, but those using rubber have poor heat resistance and deteriorate over time. Products made of glass or porcelain have poor thermal and mechanical shock resistance, and may be damaged by vibration, especially when used in rectifiers mounted on vehicles. They have a fatal flaw that makes it impossible to use them.

The above fatal flaw is corrosion resistance to refrigerants;
Because it is not possible to obtain a multi-pole terminal that maintains satisfactory aging and impact characteristics, the current-carrying terminal conductor (hereinafter simply referred to as the "carrying electrode") is replaced by a single airtight insulated terminal (hereinafter referred to as a single-pole terminal). ), which fully satisfies the above characteristics and is described in detail below, was used in the required number of poles. In this case, as the number of uses increases, it goes without saying that a mounting means is required.
The installation area was increased, the size of the device itself became larger than necessary, and manufacturing costs inevitably increased, which were unavoidable conditions. A single-electrode terminal with the above-mentioned stable characteristics is made by using a mixed powder of vitreous powder and mica powder as an airtight sealant and insulating material, and heating the raw material mixture to a temperature at which the vitreous material in this raw material softens.
This is a single-electrode terminal obtained by forming an airtight sealant and insulator. This single-electrode terminal maintains the properties required of a terminal, namely, corrosion resistance against refrigerant, heat resistance, and mechanical shock resistance, as well as extremely excellent properties including aging. By the way, there is a multi-electrode terminal derived from this excellent single-electrode terminal configuration as shown in FIG. In FIG. 1, a is a cross-sectional view, and b is a vertical cross-sectional view.

The structure will be explained below with reference to FIG. Reference numeral 1 denotes a peripheral metal fitting constituting the base body, which is made of a metal such as iron or stainless steel that can withstand heating of about 600°C, and is attached to a necessary part such as the vessel wall by welding screws or other methods. 2a is the through hole 1a in the center of the outer peripheral fitting.
2b is a conducting electrode located outside the center of the through hole 1a, 3 is an insulating material, and like the single-electrode terminal, the raw material is a mixed powder of glassy powder and mica powder. These are glass and mica plastic bodies that are heated to a temperature at which the glassy substance softens and flows under pressure, and then pressure-formed in the heated state. In the figure, a total of seven conducting electrodes 2a and 2b are shown, but the number does not matter; the important point is the position where the conducting electrodes are present. Although FIG. 1 shows the structure of a multi-electrode terminal, if the conducting electrode 2b is removed and only the conducting electrode 2a is used, it becomes a single-electrode terminal.

In the case of a single-pole terminal, the excellent characteristics described above are completely maintained, but in the case of a multi-pole terminal, the airtightness of the outer periphery of the conducting electrode 2b deteriorates when the temperature rises and falls repeatedly, which is a fatal flaw. begins to appear. Therefore, it cannot be used for applications such as airtight insulated terminals for boiling cooling devices.

The reason for this will be explained. The basic principle behind how a single-electrode terminal with this type of structure maintains excellent airtightness is that the outer periphery is The tool 1 strongly tightens the insulator 3 and also connects the conductive electrode 2
This is because the phenomenon that a is strongly tightened by the insulator 3 is realized. In other words, the insulator 3 and the conducting electrode 2a are strongly shrink-fitted by the outer peripheral fitting 1. When the conducting electrode 2a is located at the center of the through hole 1a in the center of the outer fitting 1, the outer circumferential surface of the conducting electrode 2a is equidistant from the inner wall 4 of the outer fitting 1 and is tightened with uniform pressure over the entire surface. Therefore, the airtightness is extremely stable.

In the case of the multi-pole terminal shown in FIG. 1, in addition to the conducting electrode 2a located at the center of the through hole 1a, six conducting electrodes 2b are arranged on an equal circumference.
The distances between the outer peripheral surface and the inner wall 4 of the outer peripheral outer member 1 of the other conductive electrodes 2b are all different. That is, the outer circumferential surface of the conducting electrode 2b located close to the inner wall 4 is directly compressed by the contraction of the outer circumferential metal fitting 1, but the surface on the opposite side is located at a longer distance from the inner wall 4, and
Since there is another current-carrying electrode between them, the compressive force received is reduced. In this way, the compressive force, or in other words, the tightening force, applied to the outer circumferential surface of the conducting electrode 2b is non-uniform. At room temperature after molding, it maintains sufficient airtightness, but when subjected to repeated rises and falls in temperature, the surface with weak compressive force begins to leak. As is clear from the above description, the multi-pole terminal of this structure has a fatal defect in that its airtightness deteriorates, and it cannot be used in devices that require airtightness. However, it can be used for applications that require characteristics such as watertightness.

The present invention relates to a structure of a multi-polar hermetically insulated terminal with excellent hermetic properties and a manufacturing method for obtaining the same.

FIG. 2 shows the structure of a hermetically insulated terminal according to an embodiment of the present invention. In the figure, 2a is a conducting electrode located at the center of the terminal, 2b is a conducting electrode located other than the center, and 3
5 is an insulator made of glass or mica plastic, and 5 is a base body having the same number of through holes 6 as the conducting electrodes 2a and 2b, and the hole diameter is larger than the diameter of the conducting electrodes. To explain in more detail, the conducting electrodes 2a and 2b are connected to the through hole 6.
The insulator 3 fills the gaps between the through hole 6 and the conductive electrodes 2a, 2b, and surrounds and connects the conductive electrodes 2a, 2b on the upper surface of the base 5. There is. Next, the metal materials of the conductive electrodes 2a, 2b and the base body 5 are required to withstand heating at 600°C and maintain mechanical strength. Regarding the coefficient of thermal expansion, the coefficient of thermal expansion up to the transposition temperature of glass and mica plastic bodies is used as a standard. It is safe to assume that the transition temperature of this glass or mica plastic body is equivalent to that of the raw material glass. Further, the coefficient of thermal expansion is largely controlled by the raw material glass, and its value is about 8 to 12×10 ⁻⁶ . The thermal expansion coefficient of the base body 5 is larger than that of glass or mica plastic material. Ideally, the coefficient of thermal expansion of the conductive electrodes 2a, 2b is smaller than that of the glass or mica plastic body, but there is no problem if it is equal to or larger to some extent. Since this relationship is closely related to the manufacturing method, it will be explained separately, and the relationship with the structure itself will be explained first. The feature of the multi-electrode terminal according to the present invention is that the base body 5 is provided with the same number of through holes 6 as the carrying electrodes.
Since electrodes a and 2b are located at the center of each through hole 6, the distances between the outer circumferential surfaces of the conductive electrodes 2a and 2b and the inner wall of the through hole 6 are equal over the entire surface. Therefore, due to the contraction of the base body 5, the conductive electrodes 2a, 2b are pressurized with uniform pressure over the entire surface by the glass or mica plastic body existing in the space between the inner wall of the through hole 6 and the outer peripheral surface of the conductive electrodes 2a, 2b. Therefore, regardless of whether or not the conducting electrode 2b is located at the center of the base 5, the pressurized state that appears in the conducting electrode 2a that is present at the center of the single-electrode terminal will appear in each case. . Therefore, its characteristics maintain the same value as a single-pole terminal, and the airtightness does not deteriorate even when the temperature rises and falls repeatedly, completely eliminating the fatal flaw of the conventional product shown in Figure 1. It was done.

Next, a typical manufacturing method will be explained with reference to FIG. In the figure, 7 is a molding frame, 8 is a receiving metal fitting, and holding hole 8a can hold the conducting electrodes 2a, 2b upright.
has. Reference numeral 9 has a through hole 9a through which the conductive electrodes 2a and 2b can be penetrated with pressurized metal. The mold is made up of the above three parts. It should be noted 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.

For manufacturing, a pressure molding machine is used which has a fixed platen 10 in the center, a drive section 11 at the bottom that drives up and down, and a drive section 12 at the top that drives up and down. The frame 7 is fixed to a fixed platen 10 via a jig (not shown). The receiving fitting 8 is fixed to the lower drive part 11, and the pressurizing metal 9 is fixed to the upper drive part 12 by jigs (not shown), respectively.

A base 5 is prepared. The material used for these metal fittings is one that has a thermal expansion coefficient lower than the transition temperature of glass or mica plastic material. 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 13 is prepared. This preformed body 13 is formed by pressing a mixed powder of glassy powder and mica powder into a certain shape using another press die (not shown) at room temperature. Next, the material of the conductive electrode is not particularly limited, and iron, titanium, copper alloys, such as copper chrome, etc. can be used. Although a smaller coefficient of thermal expansion is generally desirable, it can be greatly increased by changing 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 13 is prepared, and the glass materials include pbo-1.0, B ₂ O ₃ -0.4, SiO ₂ -0.4,
55w% powder obtained by grinding a molar ratio composition of AlF ₃ -0.2 into 200 meshes, 60-100% synthetic gold fluorine mica powder
Mix 45w% of mesh products, add 5w% of water to make it wet, and weigh out 320 grams.
Using another mold (not shown), by cold pressing, the outer diameter is 37φ, the height is 15mm, and the center and 26φ
A disk having six through holes of 5φ located at equal distances on the circumference was prepared, and the disk was kept in a dryer at 120° C. for 2 hours to remove moisture and complete the preparation.

Next, the base 5 is made of stainless steel with an outer diameter of 40 mm.
A disk with a mmφ height of 20 mm and six through holes of 7 mmφ located equidistantly on the center and the 26φ circumference was used. In addition, the conducting electrode is made of iron and has an outer diameter of 2.6φ, and the length is increased from a minimum of 55 mm to a maximum of 64 mm.
7 mm, each with a different length, and one end of which was finished with a radius of 1 mm was prepared. The mold is held with the receiving metal fitting 8 in the position shown in Figure 3A and the pressurizing metal 9 in the position enclosed in the frame 7, using each heating device
Heat to 300℃. The substrate 5 is heated to 550°C, and the preform 13 is heated to 600°C using a separate electric furnace (not shown). When each heating is completed, the pressurized metal 9 is first raised as shown in FIG. 3A, and the frame 7
A space is provided between them, and then the receiving metal fitting 8 is raised until its upper surface is at the same position as the upper surface of the frame 7, and the conducting electrodes 2a, 2b are inserted into the holding holes 8a of the receiving metal fitting 8. Next, the base body 5 is inserted into the through hole 6 through the conductive electrodes 2a, 2.
b is penetrated and inserted onto the receiving metal fitting 8, and subsequently the preform 13 is inserted onto the base body 5 in the same manner.
When the insertion is completed, the receiving metal fitting 8 is lowered to its original position, and the pressurizing metal fitting 9 is subsequently lowered to apply the preformed body 13 with a total pressure of 20 tons so that the conductive electrodes 2a and 2b enter the through hole 9a. Press down to obtain the condition shown in Figure 3B. The entire molded product is cooled to 320° C., and after the pressurizing metal 9 is raised, the receiving metal fitting 8 is raised to take out the molded product and the molding is completed.

Matters directly related to molding in the above manufacturing example will be explained. The holding hole 8a of the receiving bracket 8 has the function of holding the conducting electrodes 2a, 2b upright with their upper ends equidistant from each other, and allowing the conducting electrodes 2a, 2b to smoothly penetrate the through hole 9a when the pressurizing metal 9 is lowered. It is important that you keep it. Also, the conducting electrode 2
Providing a difference in the lengths of a and 2b and making the upper end curved is a means to facilitate and ensure insertion.

Next, regarding the shape of the preformed body 13, uniform molding becomes difficult if there is a large temperature drop between the insertion of the preformed body and the pressurization process during molding. In order to avoid this phenomenon, the inner wall of the frame 7 and the conductive electrode 2 are
The necessary condition is to avoid contact with the electrodes 2a and 2b, and for this purpose, the outer diameter of the hole should be smaller than the inner diameter of the frame 7, and the inner diameter of the hole should be larger than the outer diameter of the conductive electrodes 2a and 2b. is important. In addition, in this manufacturing example, a so-called lead-based glass containing lead oxide is used as the glass material constituting the preform 13, but the composition is not limited to this in any way, and for example, commercially available Lead-free enamel glazes may be used. Furthermore, since the mica powder used is mixed with glass and heated to about 600°C or higher, it cannot be used if it decomposes at this temperature. 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 becomes 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 5. It is a prerequisite that the material 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 conductive electrodes 2a and 2b contained in the base 5 existing on the outer periphery and the insulating material interposed between them. This is achieved by tightening the Therefore, the difference in thermal expansion coefficient is an important factor. Note that the conducting electrodes 2a, 2
Regarding the relationship between the coefficient of thermal expansion and b, 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, the effect will be can get. 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 5, the conductive electrodes 2a and 2b, and the preform 13, the temperature of the mold is closely related to the transition temperature of the raw glass. In other words, if it 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 low. Note that it is essential that the temperature during depressurization decomposition be lower than the rearrangement temperature, so it is important to take this point into consideration when setting the temperature. Base body 5
This temperature is closely related to the heating temperature of the preformed body 13, which will be described later. In the manufacturing process, the preform 13 is inserted onto the top surface of the base 5 and makes surface contact, so if the temperature is low, the preform 13 is cooled, increasing its viscosity, and improving its fluidity during pressure molding. However, if it is too high, its mechanical strength will decrease and there will be a risk of deformation, so it is not preferable, and in fact, it is desirable to set the temperature to be somewhat lower than the heating temperature of the preform.

Next, regarding the heating temperature of the conductive electrodes 2a and 2b, they do not come into direct contact with the preform 13 during the insertion process of molding, and the insulator 3 is press-fitted into the outer periphery for an extremely short time, and its heat capacity Since the temperature of the preform 13 is extremely small, there is almost no reduction in the temperature of the preform 13 and its fluidity, so there is no need for heating. From the viewpoint of ensuring properties, it is desirable that the temperature be lower, and since it is easier to operate, it is best to use it without heating 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 13 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, the blending ratio of glassy powder and mica powder is an important factor as it relates to the 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 there is too little, molding will become difficult. In reality, it is preferable for the glass content to be in the range of 30 to 50% in terms of capacity ratio.

Next, regarding the hole diameter of the through hole 6, the conducting electrode 2
In this case, the relationship with the outer diameters of a and 2b is mainly related to the creeping insulation resistance, and the difference in diameter has almost no effect on the airtightness. Rather, what has a large influence is the distance relationship between adjacent through holes 6. 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 about the same as the diameter of the through hole 6, its airtightness can be completely ensured.

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 terminals, completely maintains corrosion resistance, airtightness, thermal and mechanical impact strength, and completely eliminates the defects of conventional products. In order to maintain the same characteristics as a single-pole terminal, multiple single-pole terminals of this type were used in parallel, but now it is possible to achieve the purpose by using a single terminal. Not only can the device itself be made smaller and lighter, but the manufacturing process can also be greatly simplified, and the effects are extremely large.

The base body 5 can also be processed by simply providing the required number of through holes, requiring almost no precision in its dimensions, being inexpensive, and having 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 can be used for corrosion protection of metal containers filled with water. Alternatively, it can be used for metal containers filled with high-pressure gas, and its uses are extremely wide.

As described above, the multi-electrode 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 cross-sectional view showing the structure of a conventional multi-electrode terminal, in which a is a cross-sectional view and b is a vertical cross-section. FIG. 2 is a cross-sectional view showing the structure of a multi-pole terminal according to the present invention, in which a is a cross-sectional view and b is a vertical cross-sectional view. FIG. 3 is a cross-sectional view showing an example of the method for manufacturing a multi-pole terminal according to the present invention.
B shows the state immediately before pressure molding, and B shows the state after pressure molding is completed. In the figure, 2a and 2b are conductive electrodes, 3 is an insulator, 5 is a base, 6 is a through hole, 7 is a molding frame, 8 is a receiving metal fitting, 9
10 is the pressure molding machine fixed plate, 11 is the lower drive part, 12 is the upper drive part, 13
is a preform. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A base body having a plurality of through holes, a plurality of terminal conductors respectively penetrating through the plurality of through holes,
An insulator made of a glass-mica plastic body is provided which seals and fixes the through hole and the terminal conductor, and the coefficient of thermal expansion of the insulator is equal to or lower than that of the base material at a temperature below the transition temperature of the glass contained in the insulator. A multi-pole insulated terminal characterized by a coefficient of thermal expansion smaller than that of the thermal expansion coefficient. 2. A step of holding a plurality of terminal conductors within the molding frame,
accommodating a base body heated to a predetermined temperature in the molding frame, the base body having a through hole formed so as to be able to pass through each of the plurality of terminal conductors with a gap left between each; A preformed body made of vitreous material and mica, which has through-holes formed so as to be able to pass through each separately, and is heated to a predetermined temperature, is placed on the base body housed in the molded frame and the molded frame. In the step of placing the preform so as not to contact the terminal conductor, pressurize the preform and fill the space between the through hole provided in the base and the terminal conductor to connect the through hole and the terminal conductor. A method for manufacturing a multi-pole insulated terminal, characterized by comprising a step of sealing and fixing. 3. The multipole according to claim 2, characterized in that the molding is performed with the temperature of the molding frame lower than the transition temperature of the glass and the base temperature higher than the transition temperature of the glass. Method of manufacturing insulated terminals. 4. The method of manufacturing a multi-polar insulated terminal according to claim 2 or 3, characterized in that a plurality of terminal conductors having different lengths are used, and the upper end portions are curved.