JPH11176617A - Assembly structure of resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of discharge or the like before undergoing high voltage condition even if of a low resistance value, by assembling a plurality of stick ceramic resistors in parallel with a single terminal, and constituting electrodes of the resistors in a sectional structure. SOLUTION: Resistors 1 which are arranged in rows of four and files of four, sixteen in total, are clamped by a metal terminal 2A and a metal terminal 2B and fixed by means of an insulating support rod 4. In assembling, adjustment is done by means of a contact adjusting bolt 5 so as to complete contact of the individual resistors 1. Further, a contact plate is inserted so that electrodes of the resistors are not peeled off by the tip of the contact adjusting bolt 5 if the resistors 1 and the metal terminal 2A are directly contacted with each other. Furthermore, the resistors 1 and the metal terminal 2B are fixed by means of a tap plate 3 interposed by a coned disc spring therebetween, so as to mitigate length dispersion or the like of the individual resistors 1 and absorb stress caused by thermal expansion or the like of the individual resistors 1, thereby constituting electrodes of all the resistors 1 in a sectional structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly structure for a ceramic resistor. More specifically, the present invention provides an assembling structure of a ceramic resistor used in a high-voltage circuit, which is made compact by assembling a plurality of ceramic resistors in parallel with the same terminal, and which is space-saving and withstands high voltage.

[0002]

2. Description of the Related Art In general, ceramic resistors are widely used in high-voltage circuits such as high-voltage generators, large-capacity capacitor charging / discharging devices, power interrupters, and nuclear fusion devices.
Of these ceramic resistors, rod-shaped ones generally have metallized electrodes at both ends and have terminal fittings or metal caps attached to the electrodes.
Each rod-shaped resistor has a terminal fitting or a connection terminal of a metal cap, and these terminals are connected and connected by a lead wire or a metal plate (a bus bar or the like).

[0003]

In a conventional ceramic resistor in which electrodes are formed on the outer peripheral side surface of a circle and have a low resistance value, when a high voltage and a large current pulse are applied, corona discharge is generated from the electrode portion. Occur. In the case of the type in which the electrodes are formed only on the cross section of the resistor, corona discharge does not occur, but there is a disadvantage that electrical contact is easily made and cannot be held. Furthermore, in a resistor having a structure in which corona discharge is suppressed, a large terminal fitting is required, and a large space is required when a plurality of terminals are used. As a compact structure that can withstand high voltage, there is a method in which several disk-shaped resistors used for gas circuit breakers and the like are stacked and used.However, when large power is frequently applied to a disk-shaped resistor, Since it is difficult to radiate heat from the heat capacity, it is heated and causes a change in resistance, and cannot be used.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention has a structure in which a high-voltage ceramic resistor having a low resistance value does not cause corona discharge and is a compact resistor. Is provided. As a cause of the corona discharge, in the case of a conventional side electrode, a structure in which a current flows from the electrode boundary portion on the surface into the resistor element, and the contact area is reduced. It is considered that the current density increases in the portion where the contact area is small, and corona discharge occurs when the current density exceeds the allowable current density in the contact portion. In particular, since a large amount of current flows in a resistor having a low resistance value, it is considered that the current density at the contact portion increases, and corona discharge occurs from a low voltage. In order to make a compact resistor, a resistor is attached in parallel to the same metal terminal.In order to be able to cope with even higher voltages, all resistors are made with electrodes on the cross section. In order to prevent the peeling from occurring at the boundary of the above, a pressure structure by a spring and a screw was adopted so as to forcibly contact the electrode surface. In addition, the spring has a role of generating a pressure contact stress on the electrode surface and absorbing thermal expansion due to heat generation of the resistor when power is applied. In addition to forcibly pressing the screws, they also play a role in adjusting the variation in length in the production of the resistor. By using a plurality of rods with a diameter of about 8 to 16 in accordance with the power used, it was confirmed that the specific surface area was increased, the heat dissipation was improved, and the resistance was hardly heated and the resistance was stable. Was done. Further, it was confirmed that it is desirable to form a film of about 20 to 500 μm with an epoxy resin paint as an insulating layer of the resistor in order to further increase the withstand voltage.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing one embodiment of the present invention, and FIGS.
2 shows an enlarged cross-sectional view of the electrodes and terminals of the cross section. In FIG. 1, sixteen resistors 1 in four rows and four rows are used and set so as to be in parallel with the metal terminals on both sides. 1
The six resistors 1 are sandwiched between metal terminals 2 </ b> A and 2 </ b> B and fixed by insulating support rods 4. The resistor 1 is adjusted and assembled with a contact adjusting bolt 5 to complete the contact of the resistor 1. This will be described in detail with reference to FIGS.
When the resistor 1 and the metal terminal 2A are brought into direct contact with the contact adjustment bolt 5, the resistor electrode is peeled off at the tip of the bolt, so that the contact plate 7 is inserted and brought into contact. Also, resistor 1
The metal terminal 2B is fixed by contacting with the holding plate 3 with a disc spring 8 in order to reduce variations in the length of the resistor and absorb stress caused by thermal expansion of the resistor.

[0006]

EXAMPLES Examples of the present invention will be specifically described below in comparison with comparative examples. [Example 1] Outer diameter φ14 mm, length 60 mm, resistance value 1
6Ω rod-shaped epoxy resin paint for electrical insulation
Sixteen ceramic resistors (four rows and four rows) each having a thickness of 0 μm and applied as a cross-sectional electrode were assembled with the structure shown in FIG.
An impulse voltage having a waveform of 1.2 × 50 μsec was applied to this assembly, and the voltage at which discharge occurred was examined. Table 1 shows the results. [Example 2] Outer diameter φ14 mm, length 60 mm, resistance value 1
6Ω rod-shaped epoxy resin paint 5
Sixteen (four, four rows) ceramic resistors which were applied at a thickness of 00 μm and were used as cross-sectional electrodes were assembled with the structure shown in FIG. An impulse voltage having a waveform of 1.2 × 50 μsec was applied to this assembly, and the voltage at which discharge occurred was examined. Table 1 shows the results. [Comparative Example 1] Outer diameter φ14 mm, length 60 mm, resistance value 1
6Ω rod-shaped epoxy resin paint 5
The assembly was applied so as to be applied with a thickness of 00 μm, attached with a cap-type fitting to a ceramic resistor serving as a normal electrode, and further attached in parallel to 16 (four, four rows) metal plates. An impulse voltage having a waveform of 1.2 × 50 μsec was applied to this assembly, and the voltage at which discharge occurred was examined. Table 1 shows the results. [Comparative Example 2] Outer diameter φ14 mm, length 60 mm, resistance value 1
6Ω rod-shaped silicone resin paint 5
Sixteen (four, four rows) ceramic resistors which were applied at a thickness of 00 μm and were used as cross-sectional electrodes were assembled with the structure shown in FIG. An impulse voltage having a waveform of 1.2 × 50 μsec was applied to this assembly, and the voltage at which discharge occurred was examined. Table 1 shows the results. [Comparative Example 3] Outer diameter φ14 mm, length 60 mm, resistance value 1
6Ω rod-shaped epoxy resin paint 1
Sixteen ceramic resistors (four rows and four rows) each having a thickness of 0 μm and applied as a cross-sectional electrode were assembled with the structure shown in FIG.
An impulse voltage having a waveform of 1.2 × 50 μsec was applied to this assembly, and the voltage at which discharge occurred was examined. Table 1 shows the results. [Comparative Example 4] Outer diameter φ14 mm, length 60 mm, resistance value 1
6 Ω rod-shaped epoxy resin paint for electrical insulation coating
When applied with a thickness of 00 μm, cracks occurred in the film, and a good insulating film could not be obtained.

[0007]

[Table 1]

[0008]

According to the assembly structure of this resistor, it has been confirmed that even if the resistor has a low resistance value, no discharge or the like is generated to a high voltage even if it has a low resistance value. A container can be provided.

[Brief description of the drawings]

FIG. 1 is an assembly schematic diagram showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of one end of an electrode and a terminal having a cross section according to the present invention.

FIG. 3 is an enlarged cross-sectional view of the other end of the electrode and terminal of the cross section of the present invention.

[Explanation of symbols]

 1. Resistor 2. Metal terminal 2A. Metal terminal 2B. Metal terminal 3. Holding plate 4. Insulation support rod 5. 5. Contact adjustment bolt Screw 7. Contact plate 8. Disc spring

Claims (3)

[Claims] 1. A resistor assembly structure in which a plurality of rod-shaped ceramic resistors are assembled in parallel on the same terminal, wherein the electrodes of all the resistors have a cross-sectional structure. 2. The assembly structure for a resistor according to claim 1, wherein a spring material is used in a contact portion between an electrode of the resistor and a resistor terminal. 3. An inner peripheral surface of the resistor body having a thickness of 20 to 500
2. The assembly structure for a resistor according to claim 1, wherein the insulating layer is formed of an epoxy resin film having a thickness of μm.