JPH0445477B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrical bonding device for ceramics, and particularly to an electrode arrangement.

[Prior Art] FIG. 2 is a schematic diagram showing a conventional electrical bonding apparatus for ceramics. For example, when plate-shaped non-conductive ceramics are to be bonded, the , after interposing the adhesive 3 which is conductive at high temperature, the power supply 1 for energizing between the electrodes is applied.
Blowpipe electrode 1 which also serves as a discharge electrode connected to 4
6 and 17, the gap between this tip and the joint is
Arrange them facing each other so that they are about 10mm apart.

Now, the joint is heated with combustible gas flame from blowpipe electrodes 16 and 17 placed on both sides of ceramics 1 and 2.
At the same time as heating to 850 to 900°C, heat is applied between blowpipe electrodes 16 and 17 at a temperature of 3000 to
When an AC or DC voltage of 10,000V is applied, the conductivity of the adhesive 3 improves with the heating described above, and an arc discharge occurs between the blowpipe electrodes 16, 17 and both ends of the joint, resulting in an electric current of several tens of mA. A current of a certain amount or more is applied to the adhesive 3. For example, the joint width is 17
In mm ceramics, when a voltage of 6000V is applied, a current of about 0.5A flows. As a result, the adhesive 3 is heated to a high temperature by the Joule heat, melts in a short time, and the ceramics 1 and 2 are firmly joined. When the joint is rapidly heated by Joule heat, the electrical resistance value decreases significantly and the conductivity rapidly increases. For this purpose, an interelectrode current control device 15 is required to maintain the current at an appropriate value. Note that a voltage may be applied between the blowpipe electrodes before heating the joint to 850 to 900°C.

[Problems to be Solved by the Invention] However, in conventional devices in which the blowpipe also serves as an electrode, in order to properly ignite and maintain the gas flame without causing misfire, the gap between the blowpipe electrode and the joint is flammable. Although it varies depending on the type of gas, flow rate, etc., it is necessary to ensure at least 10 mm or more, and for this purpose, the required applied voltage must be increased. Therefore, applying a high voltage is not preferable from the viewpoints of work, safety, and increase in input power. In addition, because the heating width by the gas flame becomes wider, especially in the vertical direction, and the directionality of the arc is unstable, creeping discharge occurs near the top of the joint, and this state continues, causing the original purpose to be There were cases in which current was not applied to certain joints.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, a blowpipe that heats the joint part of ceramics to be joined with a gas flame and an electrode that applies a voltage to the joint part are provided. The present invention is characterized in that the blowpipe and electrode are integrated, and the tip of the electrode is disposed between the blowpipe outlet and the joint, and the blowpipe and the electrode are placed close to the joint.

[Operations and Examples] The present invention will be described below with reference to the drawings. 1st
The figure is a schematic diagram showing an embodiment of the electrical bonding device of the present invention, and similarly to FIG. are given the same reference numerals. Note that 1, 2, 3, 14, and 15 are the same as in FIG. 2, so their description will be omitted. In FIG. 1, numerals 4 and 5 are blowpipe tubes, which are disposed facing each other such that the gap between the tip and the joint is approximately 10 mm. Reference numerals 6 and 7 denote a pair of rod-shaped electrodes connected to a power source 14 for energizing between the electrodes, which are arranged facing each other so that the gap between the tip and the joint is approximately 2 mm. In the embodiment, rod-shaped electrodes 6 and 7 are attached to blowpipe tubes 4 and 5, respectively. That is, the tip of the electrode protrudes from the opening of the blowpipe. In this case, heat resistance is required for the electrode, such as tungsten,
Carbon, molybdenum, hafnium, zirconium, tantalum, iridium, etc. can be used. Among them, tungsten, carbon, hafnium, and zirconium are preferable in order to lower the discharge voltage. Reference numerals 8 and 9 denote a pair of electromagnetic cores, which are arranged to sandwich the ceramic joint, and the tips of the electrodes 6 and 7 are located in the gap between the magnetic poles, so that the ceramics can be removed from the tips of the electrodes. A strong magnetic field is generated across the outer surface of the joint. Excitation coils 10 and 11 magnetize the electromagnetic cores 8 and 9, and are connected so as to generate magnetic fields in the same direction on the left and right sides of the ceramic joint. Reference numeral 12 denotes excitation coil electrodes for the excitation coils 10 and 11, for which a DC power source is used in this embodiment.

Now, the joint part is heated to 850 to 900℃ using combustible gas flame from blowpipe 4 and 5 installed on both sides of ceramics 1 and 2.
When heating is performed and a voltage is applied between the electrodes 6 and 7, the electrical conductivity of the adhesive 3 improves with the heating, and a current is passed through the adhesive 3 through the electrodes 6 and 7 and the joint. Ru. For example, the joint width is 17
In mm ceramics, when an AC voltage of 2000V is applied, a current of about 0.5A flows. When the direction of the magnetic field B ₂ due to the current I ₁ and the current I ₂ of the excitation coil is in the direction of the solid arrow shown in Figure 1, the Lorentz force is
The arc moves in that direction, and the current-carrying part inside the ceramic also moves accordingly. When the direction of the current between the electrodes is reversed in the direction of the dotted arrow, the direction of the Lorentz force is also reversed, and the moving direction of the arc and the moving direction of the current-carrying part are also reversed. By repeating this, the current-carrying portion within the ceramic oscillates over the entire length of the joint in synchronization with the alternating current frequency. As a result, the entire length of the ceramic joint is uniformly melted and joined.

In addition, although the power source for inter-electrode energization is AC and the power source for excitation coil is DC, conversely, the power source for inter-electrode energization may be DC, and the power source for excitation coil may be AC.

Furthermore, if the length of the bond is long, the entire surface may be bonded while moving the ceramic or the blowpipe and the electrode using an appropriate moving means (not shown). Alternatively, by providing multiple pairs of blowpipe and electrodes, a wide area can be joined simultaneously.

[Effects of the Invention] As described above, according to the present invention, by bringing the electrode close to the joint, the applied voltage can be reduced compared to the conventional method, thereby reducing power equipment and improving safety for the human body. , workability is improved, etc.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the electrical bonding device of the present invention, and FIG. 2 is a schematic diagram showing a conventional electrical bonding device for ceramics. 1, 2... Ceramics, 3... Adhesive, 4, 5...
Blowpipe, 6, 7...electrodes, 14...power supply for energizing between the electrodes.

Claims (1)

[Claims] 1 By butting ceramics that are electrically conductive at high temperatures or butting ceramics with an adhesive that is electrically conductive at high temperatures, heating the joint with a gas flame, and applying a voltage to the joint. In electrical bonding equipment for ceramics, which connects ceramics by applying a heating current,
A blowpipe for heating the joint part with a gas flame and an electrode for applying voltage to the joint part are integrated,
and a ceramic electrical joining device, wherein the tip of the electrode is disposed between the spout of the blowpipe and the joint, and the blowpipe and the electrode are arranged close to the joint.