JP3489760B2 - Joining method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method of joining a pair of members to be joined with a pair of electrodes at a predetermined pressure, and applying a current to the members to be joined to each other by resistance heat generation. The stabilization of.

[0002]

2. Description of the Related Art Generally, a joining method using resistance heating is
A Joule heat is generated by supplying an electric current to the joining portion of a pair of members to be joined via an electrode, and the heat causes melting of the joining portion to join the members. Now, in the joining method using this resistance heating,
The resistance between the electrodes during the energization time changes as shown in FIG. That is, at the initial stage of energization, the micro contact point spreads between the surface of the member to be joined and the surface of the electrode, and the reduction process follows the range indicated by a in the figure depending on the state of surface contamination.

Then, the initial surface contact resistance disappears within several cycles after the start of energization, and the process proceeds to the process of increasing the specific resistance due to temperature rise and softening and crushing of the members to be joined to increase the area of the energizing path. Then, in the range indicated by b in the figure,
Since the increase in the specific resistance exceeds the decrease in the resistance due to the increase in the area of the current-carrying path, the inter-electrode resistance increases. Further, as the bonding progresses to generate and grow a nugget and the temperature rise of the members to be bonded reaches the saturation region, the resistance between the electrodes decreases as in the range indicated by c in the figure.

Further, the amount of heat generated in the members to be joined is an important factor that influences the joining quality, and Q (heat amount) = I ² (current value) × R (t) (in the electrodes and the members to be joined). Resistance values)
Therefore, the amount of heat generation can be determined by changing the energization conditions based on empirical judgment, such as the red light state due to the heat generated by the members to be joined, observation of the electrode surface, and strength measurement by extraction. In general, a method of suppressing the influence of the surface condition over time on the bonding quality and performing electrode dressing and replacement, and a method of automatically controlling the bonding conditions according to the consumption of the electrode are also used. .

FIG. 16 is a block diagram showing the construction of an apparatus for carrying out this type of conventional joining method described in, for example, Japanese Patent Laid-Open No. 61-78579, and FIG. It is a characteristic view which shows the change of the average value of resistance, and the boundary value corresponding to several consumption grades for correct | amending welding quality. It is generally known that the minimum value after the initial contact resistance disappears in the process of changing the interelectrode resistance described in FIG. 15 is proportional to the degree of electrode wear. Therefore, as shown in FIG. 17, the setter 1 in FIG. 16 divides the electrode wear degree grades according to the magnitude of the average value and presets the boundary value of each grade.

First, the resistance value between the electrodes 2 and 3 is calculated in the minimum resistance calculation circuit 5 based on the voltage between the electrodes 2 and 3 and the current measured by the toroidal coil 4 during the initial energization period of an arbitrary cycle. To be done. Next, only the minimum value among the resistance values calculated in the memory holding circuit 6 is sequentially stored, and the average value of these minimum values is calculated in the average value calculation circuit 7.

Then, the average value thus calculated is set in the setter 1 in the comparison operation circuit 8 as shown in FIG.
The phase control ignition circuit 9 controls the thyristor 10 so as to make a further step from the class I to the class II when the boundary value I is exceeded and to match the preset conditions of the class II. Then, the joining is performed. As described above, the conventional joining method is to improve the productivity by changing the joining conditions while monitoring the electrode wear with the resistance value between the electrodes, thereby extending the period of dressing or replacement of the electrodes.

[0008]

Since the conventional joining method for joining members to be joined by resistance heating is performed as described above, a general joining method in which joining conditions are determined by empirical judgment. Then, it is needless to say that the operator must have a judgment based on a highly advanced technique, and in order to obtain stable joining quality, the work is troublesome and the labor cost increases. Further, there is a problem that it is not easy in actual work to sequentially change the joining condition, that is, the applied current to an appropriate value with respect to electrode consumption, and it is difficult to obtain stable joining quality.

Furthermore, when a method of automatically controlling welding conditions as shown in FIG. 16 is used, it can be applied within a limited phenomenon of expanding the electrode tip diameter in spot welding of mild steel plate. However, when the contact surface between the electrode and the member to be joined is larger than the electrode, there is a large variation in the degree of contact at each welding point, and the degree of variation varies momentarily, or the mild steel sheet. Since it is not considered when applied to other joined members other than, it is not possible to follow, and since the occurrence of sudden failure modes such as explosion of the electrode or the joined members is not considered, from the point of full automation There was a problem that it was insufficient.

The present invention has been made in order to solve the above-mentioned problems, and grasps the change over time in the contact state between the electrode and the member to be joined due to the consumption of the electrode surface, and Welding quality is constantly evaluated by optimizing energization conditions by automatically determining the degree of wear, automatically determining the electrode replacement timing, and performing feedback control of the welding conditions during one welding point. It is an object of the present invention to provide a joining method capable of stabilizing the.

[0011]

According to a first aspect of the present invention, there is provided a joining method in which a pair of electrodes are sandwiched by a pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members are joined by resistance heating. In the joining method of joining members, the resistance value between both electrodes is measured one after another for a predetermined time from the start of energization for each dot, and the resistance between the specified number of dots is reached when the number of dots reaches the specified number of dots. The average value and the degree of variation of the values are calculated, and at least one of the energization current value and the energization time is corrected according to these calculated values.

According to a second aspect of the present invention, in the first aspect, the resistance value is the minimum value for each dot.

According to the third aspect of the present invention, the pair of members to be joined are sandwiched between the pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members to be joined are joined together by resistance heating. In the joining method, the time between the specified number of dots is measured at the time when the number of the dots reaches the specified number of dots and the time until the state reaches the specified state is detected by detecting the state of the connection for each dot. Is calculated, and at least one of the energization current value and the energization time is corrected according to these calculated values.

According to a fourth aspect of the present invention, the pair of members to be joined are sandwiched by a pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members to be joined are joined together by resistance heating. In the joining method, the resistance value between both electrodes after a predetermined time from the start of energization is sequentially measured for each dot and the average value of the resistance values between the predetermined number of dots is reached when the number of dots reaches the predetermined number of dots. And the degree of variation is calculated, at least one of the energizing current value and energizing time is corrected according to these calculated values, and the time until the state reaches the predetermined state by detecting the state of the joint at each dot. Is measured sequentially, and when the number of RBIs reaches the predetermined number of RBIs, the average value of the time between the predetermined number of RBIs and the degree of variation are calculated, and the energizing current corrected according to these calculated values. Or correction of the conduction time is obtained to perform again.

Further, a joining method according to a fifth aspect of the present invention is such that, in any one of the first, third, and fourth aspects, the joining process is stopped when the degree of variation reaches a predetermined value.

Further, a joining method according to a sixth aspect of the present invention is, in the third or fourth aspect, a predetermined state when a resistance value between both electrodes reaches a maximum value.

Further, in the joining method according to claim 7 of the present invention, in claim 3 or 4, the amount of the reflected light reflected by the joining part while irradiating the joining part with a light beam has reached a predetermined value. The time is set to a predetermined state.

Further, the bonding method according to claim 8 of the present invention is the bonding method according to claim 3 or 4, wherein a member having a melting point lower than that of the members to be bonded is disposed in the vicinity of the bonding portion, and the surface of the members is irradiated with a light beam. At the same time, the time when the amount of light reflected by the surface of the member reaches a predetermined value is set to a predetermined state.

According to a ninth aspect of the present invention, a pair of electrodes to be joined are sandwiched between a pair of electrodes at a predetermined pressure, a current is passed through the members to be joined, and the members to be joined are joined together by resistance heating. In the joining method, the maximum resistance value between the electrodes is measured sequentially after a predetermined time has passed from the start of energization for each dot, and the maximum resistance value exceeds a preset first reference value,
Further, when the maximum resistance value after the next hitting point exceeds the preset second reference value, the subsequent joining process is stopped.

According to a tenth aspect of the present invention, in the ninth aspect, the first and second reference values are the same.

Further, in a joining method according to an eleventh aspect of the present invention, in each of the first to tenth aspects, the area of each contact surface where the member to be joined and the electrode contact each other is larger for the electrode. It was designed to be large.

Further, a joining method according to a twelfth aspect of the present invention is the joining method according to any one of the first to tenth aspects, wherein the electrode is formed of a material having a larger electrical resistivity than the members to be joined.

The joining method according to a thirteenth aspect of the present invention is the joining method according to any one of the first to tenth aspects, wherein a conductive member having a melting point lower than that of the members to be joined is interposed between the members to be joined. The members to be joined are joined together by melting.

[0024]

In the joining method according to the first aspect of the present invention, at least one of the energization current value and the energization time is corrected in accordance with the average value and the degree of dispersion of the resistance value between both electrodes between the predetermined number of dots. .

Further, in the joining method according to the second aspect of the present invention, the minimum value of the resistance value between the electrodes is measured successively after a lapse of a predetermined time from the start of energization for each dot.

Further, in the joining method according to the third aspect of the present invention, at least one of the energizing current value and the energizing time is determined depending on the average value and the degree of dispersion of the time until the predetermined state between the predetermined number of dots. Is corrected.

Further, in the joining method according to the fourth aspect of the present invention, at least one of the energization current value and the energization time is corrected in accordance with the average value and the degree of dispersion of the resistance value between both electrodes between the predetermined number of dots. At the same time, the energization current value or the energization time is corrected again according to the average value and the degree of dispersion of the time to the predetermined state between the predetermined number of dots.

Further, in the joining method according to the fifth aspect of the present invention, the degree of variation in the resistance value between the electrodes between the predetermined number of dots or the degree of variation in the time until the predetermined state is reached between the predetermined number of dots. When reaches a predetermined value, the joining process is stopped.

Further, according to a sixth aspect of the present invention, in the joining method, at least the energizing current value is determined in accordance with the average value and the degree of dispersion of the time until the resistance value between both electrodes reaches the maximum value between the predetermined number of dots. Alternatively, either one of the energization times is corrected.

Further, in the joining method according to the seventh aspect of the present invention, the average value and the variation degree of the time until the amount of the reflected light of the light beam applied to the joining portion between the predetermined number of spots reaches the predetermined value. Accordingly, at least one of the energizing current value and the energizing time is corrected.

Further, in the joining method according to the eighth aspect of the present invention, until the amount of reflected light of the light beam applied to the member arranged in the vicinity of the joining portion during a predetermined number of hit points reaches a predetermined value. At least one of the energizing current value and the energizing time is corrected according to the average value of time and the degree of variation.

In the joining method according to claim 9 of the present invention, the maximum resistance value between both electrodes exceeds the preset first reference value, and the maximum resistance value after the next dot is preset. When the second reference value is exceeded, the subsequent joining process is stopped.

In the joining method according to the tenth aspect of the present invention, the determination circuits can be made compatible by setting the first reference value and the second reference value to the same value.

In the joining method according to the eleventh aspect of the present invention, the contact surface of the electrode is made larger in area than the contact surface of the member to be joined, so that the electrode surface is covered with the progress of the joining process. By actively causing familiarity with the joining members, the energization path is enlarged and the joining quality is improved.

Further, in the joining method according to the twelfth aspect of the present invention, the electrode is formed of a material having a larger electric resistivity than the members to be joined, so that the surface of the electrode becomes familiar with the member to be joined as the joining process progresses. By positively inducing it, the energization path is expanded to improve the joining quality, and the change in the resistance value inside the electrode due to the electrode deformation is clearly captured to facilitate the measurement.

In the joining method according to the thirteenth aspect of the present invention, the conductive member having a melting point lower than that of the joined members interposed between the joined members is melted and joined to form the joined members. It suppresses excessive heat generation and deformation and accurately detects the changing process of the resistance value between electrodes.

[0037]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a joining apparatus to which the joining method according to the first embodiment of the present invention is applied, and FIG. 2 shows a change in inter-electrode resistance value with an increase in joining points and an inter-electrode resistance value at every 200 points. FIG. 3 is a curve diagram showing an average value and a deviation value, and FIG. 3 is a curve diagram showing a change in inter-electrode resistance during energization when joining is performed by sandwiching a brazing material having a lower melting point between the members to be joined. 4 shows an example of a reference table for changing the energizing current value and energizing time according to the average value and deviation value of the interelectrode resistance value shown in FIG. 2 or for stopping the joining process and determining the electrode replacement time. It is a figure.

In the figure, 11 and 12 are a pair of members to be joined, 13 and 14 are a pair of electrodes that sandwich these members to be joined 11 and 12 with a predetermined pressure, and 15 is both electrodes 13 and 14.
A voltage detection unit for detecting a voltage between them, 16 is a current detection unit for detecting a current flowing between the electrodes 13 and 14 via the toroidal coil 17, and a detection unit 18 is detected by the voltage detection unit 15 and the current detection unit 16. A resistance calculation circuit that sequentially calculates the resistance value between the electrodes 13 and 14 from the voltage value and the current value. Reference numeral 19 is a memory holding circuit that stores and holds each resistance value after a predetermined time from the start of energization for each dot. Is an average value calculation circuit for calculating the average value of the resistance values held in the memory holding circuit 19 between a predetermined number of dots.

Reference numeral 21 is a standard deviation calculation circuit for calculating the degree of variation in the resistance value held in the memory holding circuit 19 between predetermined number of dots, for example, a standard deviation calculation circuit, and 22 is a reference average value and standard deviation value in advance. A reference setting circuit for setting and storing the reference value 23, a first comparison arithmetic circuit 23 for comparing the reference average value stored in the reference setting circuit 22 with the average value calculated by the average value calculation circuit 20, 24 Is the standard deviation value of the standard stored in the standard setting circuit 22, and the standard deviation calculation circuit 21.
The second comparison operation circuit for comparing with the standard deviation value calculated in step 25, the current value and the energization time are changed and corrected via the energization controller 26 in accordance with the comparison result of both comparison operation circuits 23, 24. Is an energization condition calculating circuit.

Now, the electrodes 13 and 14 accompanying the increase in the number of joining points
The transition of the resistance value during the experiment is experimentally measured, and the average value and the standard deviation value for every 200 dots are obtained as shown in FIG. As is clear from the figure, in the contact state between the electrodes 13 and 14 and the members to be joined 11 and 12, the deformation of the electrodes 13 and 14 changes transiently in the initial region d immediately after the electrode replacement. Variation occurs depending on the positions of the members to be joined 11 and 12.

After that, as the bonding process progresses, the surfaces of the electrodes 13 and 14 are deformed into a shape conforming to the members 11 and 12 to be bonded, so that the resistance value between the electrodes 13 and 14 tends to be small, and variations occur. The degree, that is, the standard deviation value, is smaller than that in the initial area d, and is in the stable area e for processing. If this state continues, electrode 1
When the current path is expanded due to the conforming deformation of Nos. 3 and 14, and the current value is controlled to be constant, heat generation becomes insufficient as the resistance decreases, and the joining quality is affected.

When the joining process is further continued, the electrode 1
Excessive deformation of the surfaces of the members 3 and 14 causes the members 11 and 12 to be joined.
Deviates from the limit that can independently correct the position variation of the electrode, or the shape of the surface of the electrodes 13 and 14 suddenly deteriorates due to the occurrence of bombing and adhesion, and the degree of variation of the contact state increases. Enter the area f. In this unstable region f, variation in the heat generation state is induced, and it becomes difficult to continue the joining process.

When the brazing material having a lower melting point is sandwiched between the members 11 and 12 to be joined, the resistance value between the electrodes 13 and 14 during the energization time is as shown in FIG. In the initial stage of about 5 to 10 cycles after the start of energization, it decreases due to the decrease of the contact resistance, and thereafter, the increase of the specific resistance or the resistance change during the melting of the brazing material is small and stable. If the resistance value is calculated, a stable and accurate value can be obtained.

Therefore, in the bonding apparatus according to the first embodiment configured as described above, first, the voltage detecting unit 15 detects the voltage between the electrodes 13 and 14 and the current detecting unit 1 first.
The current flowing between the electrodes 13 and 14 is detected by 6 respectively. Then, the resistance value between the electrodes 13 and 14 is sequentially calculated in the resistance calculation circuit 18 based on the detected voltage value and current value. Next, the memory holding circuit 19
At, each resistance value after a predetermined time from the start of energization, for example, the minimum resistance value shown in FIG. 15 is stored and held. In this case, the minimum resistance value is not affected by the change in the initial contact state and reflects the contact state between the electrodes 13 and 14 and the members to be joined 11 and 12, so that the accurate value can be grasped.

Subsequently, from the resistance values stored in the storage holding circuit 19, the average value calculation circuit 20 gives the average value between the predetermined number of dots and the standard deviation value calculation circuit 21 gives the average value between the predetermined number of dots. The degree of variation, for example, a general standard deviation value is calculated. Then, the calculated average value and standard deviation value are the standard average value and standard standard deviation stored in advance in the standard setting circuit 22 by the first and second comparison operation circuits 23 and 24, respectively. The energization condition calculation circuit 25 calculates the energization current value and the energization time, that is, the energization condition according to the result of the comparison calculation, and the energization control unit 26 specifically controls the energization condition. .

Next, the determination of the energization condition and the specific control method based on this energization condition will be described in a little more detail. As shown in FIG. 2, first, in the initial region d, both the standard deviation value and the average value are large. Therefore, the energization current value is suppressed and the energization time is lengthened, so that the local excessive heat input is suppressed and the substantially uniform heat input is achieved. Get the heat. And the electrode 1
3, 14 and the members 11, 12 to be joined progress, and the standard deviation value and the average value gradually decrease. Therefore, the energization current value is increased accordingly, and the energization is performed to suppress excessive heat input. Shorten the time.

Next, in the stable region e, the energization current value is increased as the average value decreases to compensate for insufficient heat generation.
Then, in the unstable region f, the energization current value is decreased again and the energization time is lengthened as the variation degree, that is, the standard deviation value increases. Further, when the standard deviation value exceeds a preset value, it is determined that the electrodes 13 and 14 have been consumed excessively, the joining process is stopped, and the electrodes 13 and 14 are replaced.

As described above, it is obvious that the energization condition can be determined by the average value and the standard deviation value of the resistance values between the electrodes 13 and 14, and it is actually experimental as in the reference table shown in FIG. By performing the processing, the numerical value can be quantitatively determined, and the condition number of the reference table can be experimentally determined depending on the mode of the bonding processing such as the configurations of the electrodes 13 and 14 and the members 11 and 12 to be bonded. You can

For example, an appropriate energizing current value I _opt and energizing time t _opt at the next welding point can be obtained from the average value R of the interelectrode resistance and the standard deviation value σ based on the following equations (1) and (2). it can. I _opt = k ₁ (R _i −R) + k ₂ (σ _i −σ) + I _ref (1) t _opt = k ₃ (R _i −R) + k ₄ (σ _i −σ) + t _ref (2) Here, I _ref and t _ref are conducting current values and conducting times that serve as a reference that are experimentally obtained in advance, k _{1 to} k ₄ are coefficients that can be experimentally obtained, and R _i and σ _i are the average value and standard deviation value of the interelectrode resistance, which is a reference experimentally obtained. Therefore, the energization condition calculation circuit 25 sets a reference table based on the above equations (1) and (2), and changes the energization condition according to this reference table.

Average value R and standard deviation value σ of interelectrode resistance
The predetermined number of points used for the calculation also varies depending on the form of the joining process, and it is simple and effective to experimentally determine from several tens to several hundreds of points. Also,
The average value R and the standard deviation value σ are values at a predetermined number of dots immediately before the current point is hit, and are updated at the next dot, and the value at the oldest number of dots is excluded.

As described above, according to the first embodiment, the average value and the standard deviation value of the interelectrode resistance value between the predetermined number of dots are calculated, and the energization current value and the energization time are corrected according to the calculated values. At the same time, the joining process is stopped when the standard deviation reaches a predetermined value, so the joining quality can be improved, and the inter-electrode resistance value is measured at the minimum value for each dot. As a result, it is possible to grasp the accurate value.

Example 2. In addition, in the above-mentioned Example 1, according to the average value and standard deviation value of the calculated inter-electrode resistance value,
Although the case where the energization current value and the energization time are corrected has been described, either one of the energization current value and the energization time may be appropriately corrected, and the same effect as in the case of the first embodiment is obtained. be able to.

Example 3. FIG. 5 is a block diagram showing the configuration of a joining device to which the joining method according to the third embodiment of the present invention is applied. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 27 denotes a processing time calculation circuit for calculating, for each dot, the time required to reach a predetermined bonding state, for example, the time until the inter-electrode resistance calculated by the resistance calculation circuit 18 reaches the maximum value, and 28 denotes this processing time calculation circuit. A memory holding circuit for storing and holding each time calculated in 27, 29 and 30 are average value calculation for calculating an average value and a standard deviation value between the predetermined number of dots of the time held in the memory holding circuit 28, respectively. It is a circuit and a standard deviation value calculation circuit.

Reference numeral 31 is a reference setting circuit for setting and storing the reference average value and standard deviation value in advance, and 32 is the reference average value stored in the reference setting circuit 31, and is calculated by the average value calculating circuit 29. A first comparison operation circuit for comparing the average value, 33 is a second comparison operation circuit for comparing the standard deviation value of the standard stored in the standard setting circuit 31 and the standard deviation value calculated by the standard deviation value calculation circuit 30. The comparison operation circuit 34 is an energization condition operation circuit that changes and corrects the energization current value and the energization time through the energization control unit 26 according to the comparison result of both comparison operation circuits 32 and 33.

In the joining apparatus according to the third embodiment having the above-described structure, the machining time calculating circuit 27 causes the interelectrode resistance calculated by the resistance calculating circuit 18 to reach the maximum value at each dot. The average value and the standard deviation value are calculated by the average value calculation circuit 29 and the standard deviation value calculation circuit 30 during a predetermined number of dots for the calculated time, and the energization condition calculation circuit 34 is calculated according to the calculated value. The energizing current value and energizing time are corrected, and when the standard deviation value reaches a predetermined value, the joining process is stopped.

As described above, according to the third embodiment, the energization current value and the energization time are corrected in accordance with the average value and the standard deviation value of the time until the interelectrode resistance reaches the maximum value during the predetermined number of dots. Therefore, it is possible to perform electrode diagnosis during the process of changing the bonding quality due to the change over time of electrode consumption, especially the transition process of insufficient bonding or excessive electrode consumption, and to improve the bonding quality. Can be improved.

Example 4. FIG. 6 is a block diagram showing the configuration of a joining device to which the joining method according to the fourth embodiment of the present invention is applied, and FIG. 7 is a curve diagram showing changes in the amount of light received by the light receiver in FIG. In the figure, the same parts as those in each of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted. 35 is sandwiched between both members 11 and 12 to be joined,
A brazing material having a melting point lower than 12, 36 is a light beam source,
Numeral 37 is a light receiver arranged to face the light beam source 36, and numeral 38 is a light beam which is irradiated from the light beam source 36 to a portion where the brazing material is melted and discharged. 38a and 38b are reflected.

Reference numeral 39 is a photoelectric conversion circuit for converting the amount of light received by the light receiver 37 into voltage, and 40 is this photoelectric conversion circuit 3.
The voltage conversion value converted in 9 is compared with, for example, a preset threshold value V _th as shown in FIG. 7, and when it exceeds the threshold value _Vth , a comparison operation circuit for detecting discharge of the brazing material 35, 41 is this comparison operation. A processing time calculation circuit that calculates the time until the brazing material 35 is discharged, which is detected by the circuit 40, for each dot, 42
Is a memory holding circuit for storing and holding each time calculated by the machining time calculating circuit 41, and 43 and 44 are the average value and standard deviation value of the times held in the memory holding circuit 42 between the predetermined number of dots. They are an average value calculation circuit and a standard deviation value calculation circuit which respectively calculate.

Reference numeral 45 is a reference setting circuit for setting and storing the reference average value and standard deviation value in advance, and 46 is the reference average value stored in the reference setting circuit 45 and calculated by the average value calculating circuit 43. A first comparison operation circuit for comparing the average value, and a second reference operation circuit 47 for comparing the standard deviation value of the standard stored in the standard setting circuit 45 and the standard deviation value calculated by the standard deviation value calculation circuit 44. The comparison operation circuit 48 is an energization condition operation circuit that changes and corrects the energization current value and the energization time via the energization control unit 26 according to the comparison result of both comparison operation circuits 46 and 47.

In the joining apparatus according to the fourth embodiment having the above-described structure, in the brazing process for holding the brazing material 35 between the members to be joined 11 and 12 and melting the brazing material 35 to join the brazing material 35, first, the temperature rises. Accordingly, the light beam 38 is emitted from the light beam source 36 to the position where the brazing material 35 is melted and discharged from between the members 11 and 12 to be joined, and the reflected light 38 a is detected by the light receiver 37. At this time, the amount of light received by the light receiver 37 changes as part of the reflected light 38a is reflected in different directions as the reflected light 38b as the brazing material 35 is discharged, and as shown in FIG. It decreases from g to h, and so on.

Therefore, for example, by comparing the threshold value V _th with the voltage conversion value obtained by the photoelectric conversion circuit 39 by the comparison operation circuit 40, the discharge of the brazing material 35 can be caught. At this time, for example, the time from the start of energization until the discharge of the brazing material 35 is detected by the above comparison largely depends on the heat generation state during the bonding process, that is, the electrode wear state. When the time is long, the heat generation is small, and when the time is short, the heat generation is large. Therefore, the processing time storage / holding circuit 41 calculates the time until the threshold value V _th is reached for each hit point, and the respective times obtained by these calculations are stored and held in the storage / holding circuit 42.

Thereafter, the average value calculation circuit 43 and the standard deviation value calculation circuit 44 calculate the average value and the standard deviation value between the predetermined number of dots from the respective times stored and held in this way. The value and the standard deviation value are respectively compared and calculated by the first and second comparison operation circuits 46 with the average value and the standard deviation value of each reference stored in the reference setting circuit 45, and according to the result of the comparison operation. The energization condition calculation circuit 48 calculates the energization current value and the energization time, that is, the energization condition, and the energization control unit 26.
Control is performed via.

As described above, according to the fourth embodiment, the energization current value and the energization time are corrected according to the average value and the standard deviation value of the time until the brazing material 35 is detected between the predetermined number of dots. Since it is performed, it is possible to directly and quantitatively grasp the progress of the joining process, that is, the brazing process, that is, the degree of quality, and it is possible to further improve the joining quality.

Example 5. In the fourth embodiment, the discharge of the brazing material 35 interposed between the members to be joined 11 and 12 is detected by the change in the light amount of the reflected light 38a of the light beam 38,
The case where the joining state is determined has been described.
A member having a melting point lower than that of the members 11 and 12 to be joined is disposed in the vicinity of the joint such as the side surfaces 13 and 14 of the electrodes 13 and 14, and the surface of the member is irradiated with a light beam to form the member. The joining state may be determined by the change in the amount of the reflected light due to the melting of No. 4, and the same effect as in the case of the above-described Embodiment 4 can be exhibited, and the grasping of the melting state can be ensured. Therefore, the joining quality can be further improved.

Example 6. FIG. 8 is a block diagram showing the configuration of a joining apparatus to which the joining method according to the sixth embodiment of the present invention is applied, FIG. 9 is a diagram showing an example of a reference table set by the reference setting circuit in FIG. 8, and FIG. It is a figure for explaining. In the figure, the same parts as those in each of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 49 is a reference value setting circuit for presetting and storing a reference table as shown in FIG. 9, and reference numeral 50 is a value until the interelectrode resistance for each dot calculated by the machining time arithmetic circuit 27 reaches the maximum value. A comparison calculation circuit for comparing and calculating time and the contents of the reference table preset by the reference value setting circuit 49, 51 is calculated by the energization condition calculation circuit 25 according to the comparison calculation result by the comparison calculation circuit 50. It is an energization amount resetting circuit that changes and corrects the energized current value thus determined again via the energization control unit 26.

In the joining apparatus according to the sixth embodiment having the above structure, first, as in the case of the first embodiment,
The resistance operation circuit 18, the memory holding circuit 19, the average value calculation circuit 20, the standard deviation value calculation circuit 21, the reference setting circuit 22, the first and second comparison operation circuits 23 and 24, and the energization condition operation circuit 25 cause the energization current to flow. Energization conditions such as value and energization time are set at any time. Next, as in the case of the third embodiment, the machining time calculation circuit 27 calculates the time until the interelectrode resistance calculated by the resistance calculation circuit 18 reaches the maximum value for each dot.

The time t calculated in this way is compared by the comparison calculation circuit 50 in the reference value setting circuit 49 with the reference table preset as shown in FIG. For example, when the time t is t1 or more, there is no influence of disturbance and it is determined that proper joining processing has been performed, and the welding is performed under energization conditions of a preset energization current value I0 and energization time t0. Next, when t <t1, it is determined that excessive heat is generated, and the time becomes shorter according to the length of the detection time (t1>t2>t3>).
At t4), the energization current value after the detection time is set to be smaller (I0>I1>I2> I3) as shown in FIG. 10 to suppress excessive heat generation and ensure uniform heating.

In the case of brazing in which the brazing material 35 is sandwiched between the members 11 and 12 to be energized and the brazing material 35 is melted to perform the joining process as already described in the fourth embodiment, for example. In particular, if the formation of the current-carrying path is biased due to variations in the position of the brazing filler metal 35, and if the brazing filler metal 35 is biased to one side from the center, the joining process may be performed under appropriate energizing conditions. The spread of the material 35 may be uneven, and the discharge of the brazing material 35 may be non-uniform, resulting in problems such as generation of unbrazed parts and excessive discharge.

Observing this problem, it was found that it often occurred when the detection time was short, and when the detection time was short, excessive deformation occurred, and the required shape accuracy as a product was not satisfied. It was Therefore, in Example 6 above.
By using the method described above, it is possible to compensate for the variation in the formation of the current-carrying path that is not caused by electrode consumption and the variation in the inter-electrode resistance value that is caused by the surface condition, etc., and suppress the influence of disturbance. Therefore, it is possible to remarkably improve the bonding quality as compared with the above-mentioned respective examples.

Example 7. FIG. 11 is a block diagram showing the configuration of a joining apparatus to which the joining method according to the seventh embodiment of the present invention is applied, and FIG. 12 is an energization time when joining is performed by sandwiching a brazing material having a lower melting point than the joining members. It is a curve figure which shows the change of the resistance between electrodes in the inside. In the figure, the same parts as those in each of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

Reference numeral 52 is not shown, but the resistance calculation circuit 18, the memory holding circuit 19, the average value calculation circuit 20, the standard deviation value calculation circuit 21, the reference setting circuit 22, and the first and second comparison calculation circuits shown in FIG. An energization condition setting circuit composed of 23 and 24 and an energization condition calculation circuit 25, and 53 is a maximum resistance after a predetermined time from the start of energization for each dot based on the resistance between both electrodes 13 and 14 calculated by the resistance calculation circuit 18. A maximum value calculation circuit for calculating a value, 54 is a threshold value indicated by Rth1 in FIG. 12 in advance as a first reference value, and R is a second reference value.
This is a threshold setting circuit that sets and stores the thresholds indicated by th2.

Reference numeral 55 compares the maximum resistance value calculated by the maximum value calculation circuit 53 with the threshold value Rth1 preset in the threshold value setting circuit 54, and also compares the maximum resistance value after the next hitting point with the threshold value Rth2. Then, when any one of the maximum resistance values exceeds the threshold value Rth1 and the maximum resistance value after the next hitting point exceeds the threshold value Rth2, a comparison operation circuit is outputted.
Reference numeral 56 indicates a display unit formed of, for example, an LED, CRT or the like, which indicates the termination of the joining processing by the output of the comparison operation circuit 55, and 57 indicates the termination operation by sending an interruption signal to the energization control unit 26 by the output of the comparison operation circuit 55. Is a stop signal output circuit.

In the joining apparatus according to the seventh embodiment having the above-described structure, first, the energization condition setting circuit 52 sets the energization conditions such as the energization current value and the energization time as needed. On the other hand, in the maximum value calculation circuit 53, the maximum resistance value after a predetermined time from the start of energization is calculated for each dot from the inter-electrode resistance calculated by the resistance calculation circuit 18.

Next, in the comparison operation circuit 55, the maximum resistance value and the threshold value setting circuit 54 calculated as described above are set.
When the maximum resistance value exceeds the threshold value Rth1, the maximum resistance value and the threshold value Rth2 are compared with each other and the maximum resistance value exceeds the threshold value Rth2. And the signal is sent. Then, a signal from the comparison calculation circuit 55 indicates that the joining process is stopped on the display unit 56, and the stop signal output circuit 57
Then, a stop signal is sent to the energization control unit 26 to stop the joining process.

Then, in the case of brazing in which the brazing material 35 is sandwiched between the members to be joined 11 and 12 and electric current is applied to melt the brazing material 35 to perform the joining process as already described in Example 4, for example, As for the inter-electrode resistance value, as shown by the broken line in FIG. 12 (A), the initial resistance component decreases at the initial stage of energization, and thereafter the resistance component slightly increases due to the specific resistance components of the electrodes 13 and 14 and the members to be joined 11 and 12. However, the resistance value is almost constant during good processing. On the other hand, for example, the bonded member 1
The positions of 1 and 12 are greatly collapsed, or the electrode 1
The members to be joined 11, 1
When the two come into contact with each other, excessive heat is locally generated and a bomb is generated. The inter-electrode resistance value in this case is shown in FIG.
(A) It has the maximum value R _{max (n)} as shown by the solid line. Therefore, by comparing the maximum value R _{max (n)} and the threshold value Rth1 with the comparison operation circuit 55, it is possible to detect the bombing.

When the bombing occurs, the electrodes 13 and 14 and the members 11 and 12 to be joined are partly chipped. However, depending on the chipped state, that is, how the surface shape of the electrodes 13 and 14 changes. It is possible to continue the joining process continuously after this. This can be judged by the change in the resistance between the electrodes at the hitting point after the explosion.
That is, as shown in FIG. 12B, the maximum resistance value for each dot is compared with the threshold value Rth2, and the maximum resistance value is determined as the threshold value Rth2.
If it exceeds, it can be judged that a local one-sided contact state has occurred or there is a risk of explosion, and the joining process can be stopped.

As described above, according to the seventh embodiment, by comparing the maximum value of the interelectrode resistance with the threshold value Rth1,
It is not necessary to estimate whether or not to continue machining by estimating the occurrence of a sudden explosion phenomenon and comparing the maximum value of the interelectrode resistance after the occurrence of the explosion phenomenon with the threshold value Rth2. It is possible to improve the life of the electrode by eliminating the need to replace the electrode, and to reduce the working time required for the electrode replacement.

Example 8. In the seventh embodiment, the threshold values Rth1 and Rth2 are set to different values, but the same values may be set as appropriate, and the same effects as in the case of the seventh embodiment can be obtained. thing,
Both judgment circuits can be made compatible with each other and the circuits can be simplified.

Example 9. FIG. 13 is a perspective view for explaining the concept of the joining method in the ninth embodiment of the present invention.
When the electrodes 13 and 14 and the members to be joined 11 and 12 are configured as shown in the figure, softening due to high temperature occurs cyclically on the surfaces of the electrodes 13 and 14, and thus the members to be joined 11 and 12 are joined. The electrode is deformed, that is, the depressions 13a and 14a are generated at the positions where the depressions 13a and 14a come into contact with
Gap familiarization is positively caused, and the energization path is expanded as the joining process progresses. And this phenomenon is caused by the electrode 13,
14 is remarkable when the area of the contact surface is larger than that of the joined parts 11 and 12.

As described above, according to the ninth embodiment, the electrode 1
Since the areas of the contact surfaces of the members 3 and 14 are larger than those of the members 11 and 12, the recesses 13a and 14a are more likely to become familiar and the energization path can be expanded, and the quality is stable. It enables the joining process.

Example 10. If a material having a higher electrical resistivity than the joining members 11 and 12 is used for the electrodes 13 and 14,
Mainly members to be joined 11, 12 inside the electrodes 13, 14
Since resistance heat generation in the vicinity of the contact surface with
The amount of heat that contributes to the softening and deformation of the contact surfaces of 3 and 14 increases, for example, the formation of the depressions 13a and 14a illustrated in FIG. 13 is promoted, and the energization path is significantly expanded. further,
Since the electric resistivity is high, it is possible to clearly detect the change in the resistance value inside the electrode due to the electrode deformation.

For example, when joining silver-based, copper-based, or iron-based materials, it is preferable to use molybdenum, tungsten, copper-tungsten alloy, silver-tungsten alloy, chromium-copper alloy, or the like as the material of the electrodes 13 and 14. In particular, when the members 11 and 12 to be joined are composed of a silver-based contact material and a copper-based pedestal, it is more preferable to use the above materials.

Example 11. FIG. 14 is a first embodiment of the present invention.
It is a block diagram which shows the structure of the joining apparatus to which the joining method in 1 is applied. In the figure, the same parts as those in each of the above-described embodiments are designated by the same reference numerals, and the description thereof will be omitted. Reference numeral 58 denotes the resistance calculation circuit 18, the memory holding circuit 19, the average value calculation circuit 20, the standard deviation value calculation circuit 21, the reference setting circuit 22, the first and second comparison calculation circuits 23 and 24, and the energization condition calculation shown in FIG. A first energization condition setting circuit composed of the circuit 25, 59 is the photoelectric conversion circuit 39, the comparison operation circuit 40, the processing time operation circuit 41, the reference value setting circuit 45, the first and second comparison operations shown in FIG. A first energization condition operation circuit composed of the circuits 46 and 47 and the energization condition operation circuit 48, and 60 is a maximum value calculation circuit 53, a threshold value setting circuit 54, shown in FIG.
Comparison calculation circuit 55, display unit 56, stop signal output circuit 57
Is a power supply stop signal output circuit.

In the joining apparatus of the eleventh embodiment configured as described above, for example, a silver-based contact material having a size of 4 × 6 × 2 mm, a copper pedestal having a size of 3 × 50 × 6 mm and a member 11 to be joined,
A silver-tungsten alloy electrode 12 having a plate-shaped or silver brazing or phosphor copper brazing material fixed in advance on the pedestal contact surface side of the contact material is sandwiched between them and the contact surface with the members to be joined 11, 12 is 10 × 10 mm. And copper-tungsten alloy electrode 1
With the configurations of 3 and 14, electricity was applied to perform brazing. At this time, the contact surfaces of the members 11, 12 to be contacted with the electrodes 13, 14 were 4 × 6 mm on the contact side and 3 × 8 mm on the pedestal side.

Then, the first energization condition setting circuit 58 calculates the average value and standard deviation value of the interelectrode resistance value between the predetermined number of dots and corrects the energization current value and the energization time according to the calculated values. In addition, the second energization condition setting circuit 59 corrects the energization current value and the energization time according to the average value and standard deviation value of the time until the brazing material 35 is detected between the predetermined number of dots. In addition, in order to detect the abnormality of sudden electrode consumption, the energization stop signal output circuit 60 compares the maximum value of the interelectrode resistance with the threshold value Rth1.
Whether or not the machining can be continued is determined by estimating the occurrence of a sudden explosion phenomenon and comparing the maximum value of the interelectrode resistance after the occurrence of the explosion phenomenon with the threshold value Rth2.
As the predetermined number of RBIs, it is preferable to use a value with several tens to several hundreds of RBIs, further several tens to 100, and further 50 to 100 RMBs. Is more preferably used.

As described above, according to the eleventh embodiment, the brazing material 35 having a lower melting point is sandwiched between the members 11 and 12 to be joined, and the brazing material 35 is melted to perform the brazing process. Therefore, since the members to be joined 11 and 12 themselves are not deformed and melted due to excessive heat input, the shape of the surface contacting the electrodes 13 and 14 is not significantly deformed, and the fluctuation of the specific resistance is small. It is possible to accurately detect the changing process of the inter-electrode resistance value due to the electrode surface deformation.

[0088]

As described above, according to claim 1 of the present invention, a pair of members to be joined are sandwiched by a pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members to be joined are heated by resistance heating. In the joining method of joining each other, the resistance value between both electrodes after a predetermined time from the start of energization is sequentially measured for each dot and the resistance value between the predetermined number of dots is reached when the number of dots reaches the predetermined number of dots. Since the average value and the degree of variation of the values are calculated and at least one of the energizing current value and the energizing time is corrected according to these calculated values, a joining method capable of improving and stabilizing the joining quality is provided. be able to.

According to the second aspect of the present invention, the resistance value is set to the minimum value for each dot in the first aspect, so that the accurate value can be easily grasped, and the bonding quality can be improved and stabilized. It is possible to provide a simple joining method.

According to claim 3 of the present invention, a pair of electrodes are sandwiched by a pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members to be joined are joined by resistance heating. In the method, the state of the joint is detected for each RBI and the time until the condition reaches a predetermined state is sequentially measured, and when the number of RBI reaches the predetermined number of RMB, the average of the time between the predetermined number of RMB Since the value and the degree of variation are calculated and at least one of the energizing current value and the energizing time is corrected according to these calculated values, it becomes possible to diagnose the electrode when the electrode is worn out, and to improve the bonding quality. It is possible to provide a joining method that can be further stabilized.

According to claim 4 of the present invention, a pair of electrodes to be joined are sandwiched by a pair of electrodes at a predetermined pressure, a current is passed through the members to be joined, and the members to be joined are joined by resistance heating. In the method, the resistance value between both electrodes is measured one after another for a predetermined time from the start of energization for each dot, and when the number of dots reaches the specified number of dots, the average value and variation of the resistance value between the specified number of dots are measured. The degree is calculated and at least one of the energizing current value and energizing time is corrected according to these calculated values.Furthermore, the time until the state reaches a predetermined state by detecting the joining state at each dot is sequentially When the number of hit points reaches the specified number of hit points while measuring, the average value of the time and the degree of variation between the specified number of hit points are calculated, and the energization current value corrected according to these calculated values or Since the electrical time is corrected again, it is possible to compensate for the variation in the inter-electrode resistance value, suppress the influence of disturbance, and further improve and stabilize the bonding quality. A method can be provided.

According to the fifth aspect of the present invention, in any one of the first, third, and fourth aspects, the joining process is stopped when the degree of variation reaches a predetermined value, so that the joining quality is improved. In addition, it is possible to provide a bonding method that can be stabilized.

Further, according to claim 6 of the present invention, in claim 3 or 4, since the time when the resistance value between both electrodes reaches the maximum value is set to a predetermined state, the electrode diagnosis at the time of electrode consumption can be performed. As a result, it is possible to provide a joining method capable of further improving and stabilizing the joining quality.

According to a seventh aspect of the present invention, in the third or fourth aspect, the time when the light beam is applied to the joint portion and the amount of the reflected light reflected by the joint portion reaches a predetermined value. Since the predetermined state is adopted, it is possible to provide a joining method capable of grasping the progress of the joining process and further improving and stabilizing the joining quality.

According to claim 8 of the present invention, in claim 3 or 4, a member having a melting point lower than that of the members to be joined is disposed in the vicinity of the joining portion, and the surface of the member is irradiated with a light beam. A joining method capable of reliably grasping the molten state and further improving and stabilizing the joining quality because the time when the amount of the reflected light reflected on the surface of the member reaches a predetermined value is set to a predetermined state. Can be provided.

According to claim 9 of the present invention, a pair of electrodes to be joined are sandwiched by a pair of electrodes at a predetermined pressure, an electric current is passed through the members to be joined, and the members to be joined are joined by resistance heating. In the method, the maximum resistance value between the electrodes is sequentially measured after a lapse of a predetermined time from the start of energization for each dot, and the maximum resistance value exceeds a preset first reference value, and the maximum resistance value after the next dot is set. When the value exceeds the preset second reference value, the subsequent joining process is stopped.
It is possible to provide a joining method capable of improving the joining quality and stabilizing it, as well as improving the electrode life and reducing the electrode replacement work time.

According to the tenth aspect of the present invention, since the first and second reference values are the same in the ninth aspect, not only is the joining quality improved and stabilized, but the decision circuit is simplified. It is possible to provide a joining method that can be realized.

According to the eleventh aspect of the present invention, in each of the first to tenth aspects, the area of each contact surface where the member to be bonded and the electrode contact each other is larger for the electrode. Since it is formed, the energization path can be enlarged, and a joining method capable of improving and stabilizing the joining quality can be provided.

According to a twelfth aspect of the present invention, in any one of the first to tenth aspects, the electrodes are formed of a material having a larger electric resistivity than the members to be joined, so that the energization path can be expanded. Further, it is possible to provide a joining method capable of clearly grasping the change of the resistance value inside the electrode and improving and stabilizing the joining quality.

According to a thirteenth aspect of the present invention, in any one of the first to tenth aspects, a member having a melting point lower than that of the members to be joined is interposed between the members to be joined and the members are melted. By doing so, excessive heat generation and deformation of the members to be joined are suppressed and the members to be joined are joined together, so changes in the interelectrode resistance value due to electrode surface deformation can be accurately detected, and the joining quality can be improved. It is possible to provide a joining method capable of improving and stabilizing

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a joining device to which a joining method according to a first embodiment of the present invention is applied.

FIG. 2 is a curve diagram showing a change in inter-electrode resistance value with an increase in the number of joining dots and an average value and a deviation value of the inter-electrode resistance value at every 200 dots.

FIG. 3 is a curve diagram showing a change in interelectrode resistance during energization time when a brazing material having a lower melting point is sandwiched between the members to be joined and joined.

FIG. 4 changes the energizing current value and energizing time according to the average value and the deviation value of the interelectrode resistance values shown in FIG.
It is a figure which shows an example of the reference table for stopping a joining process and determining an electrode exchange time.

FIG. 5 is a block diagram showing a configuration of a joining device to which a joining method according to a third embodiment of the present invention is applied.

FIG. 6 is a block diagram showing a configuration of a joining device to which a joining method according to a fourth embodiment of the present invention is applied.

FIG. 7 is a curve diagram showing changes in the amount of light received by the light receiver in FIG.

FIG. 8 is a block diagram showing a configuration of a joining device to which a joining method according to a sixth embodiment of the present invention is applied.

9 is a diagram showing an example of a reference table set by a reference setting circuit in FIG.

FIG. 10 is a diagram for explaining energization conditions.

FIG. 11 is a block diagram showing a configuration of a joining device to which a joining method according to a seventh embodiment of the present invention is applied.

FIG. 12 is a curve diagram showing a change in interelectrode resistance during energization time when a brazing material having a lower melting point is sandwiched between the members to be joined and joined.

FIG. 13 is a perspective view for explaining the concept of the joining method in the ninth embodiment of the present invention.

FIG. 14 is a block diagram showing a configuration of a joining device to which a joining method according to an eleventh embodiment of the present invention is applied.

FIG. 15 is a curve diagram showing changes in inter-electrode resistance during energization time.

FIG. 16 is a block diagram showing a configuration of an apparatus for carrying out a conventional joining method.

FIG. 17 is a characteristic diagram showing a relationship between a change in average value of inter-electrode resistance with an increase in the number of joining points and boundary values corresponding to several wear grades for correcting welding quality.

[Explanation of symbols]

11,12 Members to be joined, 13,14 Electrodes, 13a,
14a hollow part, 15 voltage detection part, 16 current detection part, 18 resistance calculation circuit, 19, 28, 42 storage holding circuit, 20, 29, 43 average value calculation circuit 21, 3
0,44 standard deviation value calculation circuit, 22, 31, 45, 4
9 reference setting circuit, 23, 32, 46 first comparison operation circuit, 24, 33, 47 second comparison operation circuit, 25,
34, 48 energization condition calculation circuit, 26 energization control unit, 2
7, 41 Processing time arithmetic circuit, 35 brazing material, 36 light beam source, 37 light receiver, 38 light beam, 38a, 3
8b reflected light, 39 photoelectric conversion circuit, 40, 50, 55
Comparative arithmetic circuit, 51 energization amount resetting circuit, 52 energization condition setting circuit, 53 maximum value calculating circuit, 54 threshold value setting circuit, 56 display section, 57 stop signal output circuit, 58
First energization condition setting circuit, 59 Second energization condition setting circuit, 60 Energization stop signal output circuit.

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takao Hirosawa 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Yutaro Ando 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Incorporated (56) Reference JP-A-61-78579 (JP, A) JP-A-1-278973 (JP, A) JP-A-2-220785 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 11/24

Claims (13)

(57) [Claims] 1. In a joining method of sandwiching a pair of members to be joined with a pair of electrodes at a predetermined pressure and applying a current to the members to be joined to join the members to be joined by resistance heating, energization is started at each dot. After that, the resistance value between the two electrodes is measured sequentially after a predetermined time, and when the number of the above-mentioned dots reaches the predetermined number of dots, the average value and the degree of variation of the resistance value between the predetermined number of dots are calculated. A joining method characterized in that at least one of an energization current value and an energization time is corrected according to a calculated value. 2. The bonding method according to claim 1, wherein the resistance value is a minimum value for each dot. 3. A joining method for joining a pair of members to be joined by a pair of electrodes at a predetermined pressure and applying a current to the members to be joined to each other by resistance heating to join the members to each other at each welding point. The time until the state reaches a predetermined state is sequentially measured, and the average value and the degree of variation of the time between the predetermined number of RBIs are measured when the number of RBIs reaches the predetermined number of RBIs. And a correction method for correcting at least one of the energizing current value and the energizing time according to these calculated values. 4. A joining method for joining a pair of members to be joined with a pair of electrodes at a predetermined pressure to cause a current to flow through the members to be joined to join the members to be joined by resistance heat generation, and energization is started at each welding point. After that, the resistance value between the two electrodes is sequentially measured after a predetermined time, and at the time when the number of the above-mentioned dots reaches the predetermined number of dots, the average value and the degree of dispersion of the resistance value between the predetermined number of dots are calculated. At least one of the energizing current value and the energizing time is corrected according to the calculated value, and the time until the state reaches a predetermined state is detected by detecting the state of the joining for each dot and At the time when the number of RBIs reaches a predetermined number of RBIs, the average value and the degree of variation of the time between the predetermined number of RBIs are calculated, and the corrected energizing current is corrected according to these calculated values. A joining method characterized in that the value or the energization time is corrected again. 5. The joining method according to claim 1, wherein the joining process is stopped when the degree of variation reaches a predetermined value. 6. A predetermined state when a resistance value between both electrodes reaches a maximum value is set to a predetermined state.
The joining method described. 7. The method according to claim 3, wherein a time point when a light beam is applied to the joint portion and a quantity of reflected light reflected by the joint portion reaches a predetermined value is set to a predetermined state. How to join. 8. A member having a melting point lower than that of a member to be joined is disposed in the vicinity of the joined portion, the surface of the member is irradiated with a light beam, and the amount of reflected light reflected by the surface of the member is a predetermined value. The joining method according to claim 3 or 4, characterized in that the time point at which the temperature reaches is set to a predetermined state. 9. A joining method for joining a pair of members to be joined by a pair of electrodes at a predetermined pressure to cause a current to flow through the members to be joined to join the members to be joined by resistance heat generation, and energization is started at each welding point. The maximum resistance value between the both electrodes after a predetermined time is sequentially measured, and the maximum resistance value exceeds the preset first reference value, and the maximum resistance value after the next dot is preset. A joining method characterized in that the subsequent joining process is stopped when the second reference value is exceeded. 10. The bonding method according to claim 9, wherein the first and second reference values are the same value. 11. The joint according to claim 1, wherein the contact surface where the member to be joined and the electrode come into contact with each other is formed so that the electrode has a larger area. Method. 12. The joining method according to claim 1, wherein the electrode is made of a material having a larger electrical resistivity than the members to be joined. 13. The members to be joined are joined by interposing a conductive member having a lower melting point than the members to be joined between the members to be joined and melting the members. The joining method according to any one of claims 1 to 10.