JP2778146B2 - Electrical joining method of current-carrying terminal member of ceramic heating element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to an electric joining method for locally heating a butt portion of a heating member and a current-carrying terminal member constituting a ceramic heating element.

<Problems to be solved by the conventional technology and the invention> As a method of joining ceramics, brazing, reaction sintering, solid phase diffusion, etc. using various joining agents have been proposed. In order to promote the heat treatment, a step of heating to a high temperature is required. For example, if the member to be joined is placed in a high-temperature furnace, and the member to be joined must be heated to a predetermined temperature by radiation or convection from a heater of the high-temperature furnace, so if the member to be joined becomes large, Accordingly, the equipment of the high-temperature furnace becomes expensive, and if the furnace becomes large, the time required for heating to a predetermined temperature and the cooling time become long, and the running cost becomes high.

Therefore, as shown in FIG. 5, both ends of the heat-generating member 1 and the current-carrying terminal members 2a and 2b are butted with the first and second bonding agents 3a and 3b interposed therebetween, and these are joined to the power supply device 4. The two electrodes 10a and 10b are opposed to each other while being pressed in the direction of the abutting surface so as to sandwich the two electrodes 10a and 10b. At the time of joining, the bonding agents 3a and 3b are reacted mainly by Joule heat generated by the heating member 1 having high and low resistance due to the heating current flowing through the heating member 1, the conductive terminal members 2a and 2b, and the bonding agents 3a and 3b. It is also conceivable that the heat-generating member and the current-carrying terminal member are simultaneously joined at two places.

However, in the case of joining as described above, the entire heating member 1 generates uniform Joule heat and is heated to a high temperature, and it is not possible to efficiently heat only the butt portion to a desired joining temperature efficiently. There is much waste in terms of power consumption.

Further, when the butt portion is heated to a desired joining temperature, for example, about 1500 ° C., the temperature becomes 1700 ° C. to 1800 ° C. or more at the central portion in the longitudinal direction of the heat generating member 1, and the decomposition of the ceramics starts to occur, and the deterioration is started. There is a possibility that the entire heat generating member 1 is covered.

<Means for Solving the Problems> The present invention is directed to claim 1 in order to solve the above problems.
In the above method, both ends of the heat generating member constituting the ceramic heat generating element and the first and second energizing terminal members are butted directly or with the first and second bonding agents interposed therebetween, and the first and second connecting members are brought into contact with each other. A first and a second electrode are respectively brought into contact with the outer peripheral surface of the second terminal member and a current bypass for making most of the heating current flowing through the heating element at the time of joining from the vicinity of both butted portions of the heating member. By providing at least one member to be joined, in which the member is brought into contact with the outer peripheral surface of the heat generating member, a joule generated more in the heat generating member in the vicinity of the butt portion by a heating current by applying a voltage between the electrodes. The joint and the vicinity thereof are heated by heat and Joule heat generated in the joint, and the joints are simultaneously joined.

According to a second aspect of the present invention, both ends of the heating member constituting the ceramic heating element and the first and second current-carrying terminal members are butted directly or with the first and second bonding agents interposed therebetween. The first counter electrode is brought into contact with the outer peripheral surface between the current-carrying terminal member and the heat generating member near the first butting portion, and the outer peripheral surface between the second current-carrying terminal member and the heat generating member near the second butting portion And a heating member controlled by separately applying a voltage between the first and second counter electrodes, thereby causing the heating member in the vicinity of the first and second butting portions to contact the second and third counter electrodes. It is characterized in that the butted portion and the vicinity thereof are heated by the Joule heat generated in many portions and the Joule heat generated in both butted portions, and the butted portions are simultaneously joined.

<Operation> By adopting the method of claim 1 as described above, the first
The heating current at the time of joining that flows sequentially from the current-carrying terminal member to the first butting portion and the heating member in the vicinity thereof does not flow over the entire length of the heating member. In accordance with the resistance ratio, the current is shunted to the current bypass member, and the entire current for heating again flows sequentially to the heating member near the other butting portion, the second butting portion, and the second energizing terminal member. . In this case, as the resistance of the current bypassing member becomes larger than the resistance of the heat generating member during this time, the current flowing through the heat generating member during this time decreases, and the Joule heat generated at this portion decreases. In addition, since the resistance of the current-carrying terminal member is smaller than the resistance of the heat-generating member in the vicinity of the joint, the heat-generating member in the vicinity of the joint generates the largest amount of heat due to the heating current. For example, heat generated by contact resistance or heat generated by the resistance of the bonding agent can be combined to heat the butted portion and its vicinity.

According to the method of the second aspect, the first heating current at the time of joining that flows sequentially from the first current-carrying terminal member to the first butting portion does not flow over the entire length of the heating member. This current flows only in the heat generating member near the butting portion, and on the other hand, the second heating current flowing from the second conducting terminal member to the second butting portion flows only in the heat generating member near the other butting portion. Therefore, similarly to the first aspect, the heat generated by the heat generating member in the vicinity of the butting portion and the heat generated by the contact resistance or the heat generated by the resistance of the bonding agent can be combined to heat the butting portion and the vicinity thereof, and separately. By controlling the heating current, both butted portions can be accurately heated to a desired joining temperature.

<Example> A first example corresponds to claim 1 of the present invention.

FIG. 1 is a schematic partial cross-sectional view showing a first embodiment to which the method of the present invention is applied. First, both ends of the heat-generating member 1 made of a pipe-shaped silicon carbide-based ceramic having high and low resistance and the first
Then, the first and second conductive bonding agents 3a, 3b in the form of paste made of Si, SiC, C, and a binder are applied to the current-carrying terminal members 2a, 2b of silicon carbide ceramics having a low resistance and the second, respectively. These were butted and fixed by applying a pressure P of about 10 kg / cm ² .

Next, the first and second electrodes 5a and 5b connected to the power supply device 4 in a ring shape and, for example, divided into two parts are connected to the first and second energizing terminal members 2 in the vicinity of both butting portions, respectively.
Bolt the outer peripheral surfaces of a and 2b tightly. A highly conductive heat-resistant material having a cylindrical shape and, for example, divided into two parts, and having a longitudinal dimension slightly smaller than that of the heat generating member 1;
For example, a current bypass member 6 made of carbon is bolted to the outer peripheral surface of the heat generating member 1 except for the vicinity of both abutting portions, so as to be in tight contact with each other. Further, in order to prevent heat dissipation at the butted portions, the entire vicinity of both butted portions is covered with heat insulating materials 7a and 7b.

Thereafter, when the bonding atmosphere is an inert gas, for example, Ar gas, and a voltage is applied between the first and second electrodes 5a and 5b,
The heating current that flows sequentially from the first current-carrying terminal member 2a to the first bonding agent 3a and to the heat generating member 1 near the butting portion does not flow over the entire length of the heat generating member 1, and most of this current is current. The current is completely diverted to the bypass member 6, and the original total heating current again flows sequentially to the heating member 1, the second bonding agent 3b, and the second energizing terminal member 2b in the vicinity of the other butting portion. Joule heat is generated in accordance with the resistance value at the section. By the way, since the resistance value of the heating member 1 is larger than others,
The conduction of Joule heat, which is mainly generated in a part thereof, and the Joule heat due to both the current-carrying terminal members 2a, 2b and the bonding agents 3a, 3b are combined, so that the entire vicinity of both butted portions is intensively heated to a higher temperature. The two joining agents 3a and 3b were reacted while the both butted portions were held at about 1500 ° C. for 15 minutes, and then cooled to room temperature to complete the joining. The current was gradually increased and decreased during energization to prevent breakage due to rapid heating and rapid cooling.

 The second embodiment corresponds to claim 1 of the present invention.

FIG. 2 is a schematic partial cross-sectional view showing a second embodiment to which the method of the present invention is applied. The difference from FIG. 1 is that the current bypass member 6 includes current collecting members 61a and 61b and lead wires. 62
It is composed of The current collecting members 61a and 61b have a ring shape and are, for example, divided into two parts, and each of them is brought into close contact with the outer peripheral surface of the heat generating member 1 near both butted portions. Then, the current collecting members 61a and 61b are connected by a lead wire 62.

With the above configuration, the heating current that flows sequentially from the first energizing terminal member 2a to the first bonding agent 3a and the heating member 1 near the butting portion does not flow over the entire length of the heating member 1. Most of the current is collected by the current collecting member 61a, flows through the lead wire 62 to the current collecting member 61b, and the original total heating current is again applied to the heating member 1 and the second bonding agent near the other butting portion. 3b, and flows sequentially to the second energizing terminal member 2b.

 The third embodiment corresponds to claim 1 of the present invention.

FIG. 3 is a schematic partial cross-sectional view showing a third embodiment to which the method of the present invention is applied. The difference from FIG. 1 is that a large number of parts are simultaneously connected from the power supply device 4 to each electrode. Wiring is connected in series. This series connection is, for example, when two heat generating members are joined by the above-described method, a first member including a heat generating member 1, current-carrying terminal members 2a, 2b, bonding agents 3a, 3b, electrodes 5a, 5b, and a current bypass member 6. To be joined 5
Between the inner electrode 5a and the electrode 51b in the second bonded component 51 including the heat generating member 11, the conducting terminal members 21a and 21b, the bonding agents 31a and 31b, the electrodes 51a and 51b, and the current bypass member 61. The power supply device 4 is connected to the power supply device 4, and the electrode 5 b in the first bonded component 5 is directly connected to the electrode 51 a in the second bonded component 51.

In the case of serial connection, the power supply device 4 preferably has a high voltage output.

The connection method may be parallel connection, and in this case, the power supply device 4 preferably has a large current output.

By the way, in the above embodiment, if the current flowing through both butted portions is naturally the same, and if the resistance values of the heating member and the bonding agent and the electrode positions vary greatly, the heating temperature difference between both butted portions becomes large. There is a possibility that, for example, one of them may be overheated to an optimum junction temperature or more.Therefore, it is necessary to consider the variation in the resistance value. However, if this is not solved, the following implementation is required. The example solves this problem.

 The fourth embodiment corresponds to claim 2 of the present invention.

FIG. 4 is a schematic partial cross-sectional view showing a fourth embodiment to which the method of the present invention is applied. First, the both ends of the heat generating member 1 and the current-carrying terminal members 2a and 2b, which are the same as those in the first embodiment, are connected to each other by paste-like first and second conductive bonding agents 3a made of Si, SiC, C and a binder, respectively. , 3b, which were butted together and fixed by applying a pressure P of about 10 kg / cm ² .

Next, the first counter electrodes 8a and 8a ′ connected to the first power supply device 4a in the shape of a ring and divided into two parts, for example,
Each of the first energizing terminal member 2a and the heat generating member 1 in the vicinity of the first butting portion is tightly contacted by bolting to the outer peripheral surface thereof. Then, the second counter electrodes 8b and 8b 'having the same shape as the above connected to the second power supply device 4b are respectively attached to the outer peripheral surfaces of the second energizing terminal member 2b and the heat generating member 1 near the second butting portion. Tighten the bolts to make tight contact. In addition, in order to prevent heat dissipation at the butted portion, the entire vicinity of both butted portions is thermally insulated 7a, 7a.
Cover with b.

In the above configuration, when the bonding atmosphere is an inert gas, for example, Ar gas, and a voltage is applied between the first counter electrodes 8a and 8a 'and between the second counter electrodes 8b and 8b', the first energizing terminal The heating current that flows sequentially from the member 2a to the first bonding agent 3a and the heating member 1 near the first butting portion does not flow over the entire length of the heating member 1, and this current is only generated near the first butting portion. Flows through. The heating current flowing from the second current-carrying terminal member 2b to the second bonding agent 3b and the heating member 1 near the second butting portion flows only in the vicinity of the second butting portion, and each of the heating currents depends on the resistance value. Joule heat is generated. However, as described above, in order to correct the heating temperature difference due to the difference in the resistance value between the two butted portions and the vicinity thereof, the first and second power supply devices 4a and 4b are sensed while respectively sensing the heating temperatures of the two butted portions. Is separately controlled. During energization, the current was gradually increased and decreased as in the first embodiment.

In the above embodiment, the electrode may be attached to the current-carrying terminal member at an end instead of near the abutting portion because the resistance of the terminal member is smaller than the other members.

Although the case of the silicon carbide heating element has been described, for a melting substance such as a molybdenum silicide heating element, the heating member and the current-carrying terminal member are directly butted with no intervening bonding agent. The butt portion and its vicinity can be heated by the method to join the butt portion.

<Effects of the Invention> As described above, according to the present invention, the common effect of claims 1 and 2 is that both butted portions at the time of joining are effectively heated by Joule heat, so that joining can be performed in a shorter time. This makes it possible to reduce the equipment cost and the running cost due to the power consumption. Further, when the joining temperature is high, it is possible to prevent the deterioration of the heat generating member from extending to the whole.

According to the second aspect of the present invention, since the joining conditions at both butting portions can be controlled to be the same, it is possible to prevent poor joining or deterioration of the heating member due to a variation in the resistance value of the heating member.

[Brief description of the drawings]

FIG. 1 to FIG. 4 are schematic partial sectional views showing first to fourth embodiments to which the method of the present invention is applied, respectively. FIG. 5 is a schematic configuration sectional view showing a conventional example. 1 ... ceramic heating element, 2a, 2b ... energizing terminal member, 3
a, 3b ... bonding agent, 5a, 5b ... electrode, 5, 51 ... structure to be bonded, 6, 61 ... current bypass member, 8a, 8a ', 8b, 8b' ...
... counter electrode.

Continuation of the front page (56) References JP-A-58-126690 (JP, A) JP-A-63-26981 (JP, A) JP-A-60-172191 (JP, A) JP-A-63-285891 (JP) , A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05B 3/14 H05B 3/02 H05B 3/00 C04B 37/02

Claims (2)

(57) [Claims] In a method of joining a current-carrying terminal member of a ceramic heating element, both ends of a heat-generating member and first and second current-carrying terminal members are directly or through first and second bonding agents, respectively. The first and second electrodes are brought into contact with the outer peripheral surfaces of the first and second terminal members, respectively, and most of the heating current flowing through the heating element at the time of joining is
Providing at least one member to be joined constituted by contacting an outer peripheral surface of the heat generating member with a current bypass member for bypassing the vicinity of both butting portions of the heat generating member, and applying a voltage between the electrodes. By the heating current by
A method of electrically connecting a current-carrying terminal member of a ceramic heating element that simultaneously heats the butting portion and the vicinity thereof with the Joule heat generated by the heat generating member near the butting portion and the Joule heat generated at the butting portion and simultaneously joins the butting portion. . 2. A method for joining a current-carrying terminal member of a ceramic heating element, wherein both end portions of the heat-generating member and the first and second current-carrying terminal members are directly or through first and second bonding agents, respectively. Butting, the first energizing terminal member and the first
The first counter electrode is brought into contact with the outer peripheral surface of the heat generating member near the butting portion, and the second counter electrode is formed on the outer peripheral surface of the second energizing terminal member and the heat generating member near the second butting portion. Are brought into contact with each other, and the first current is controlled by applying a voltage separately between the first and second counter electrodes.
And an energizing terminal member of a ceramic heating element that heats the butted portion and its vicinity by joining the butted portions simultaneously by Joule heat generated by the heat generating member near the second butted portion and Joule heat generated at both butted portions. Electrical joining method.