JP6185793B2 - Terminal connection structure, manufacturing method and manufacturing apparatus thereof - Google Patents

Description

  The present invention relates to a terminal connection structure for connecting a copper clad aluminum electric wire to a crimp terminal by thermocompression bonding, and a manufacturing method and a manufacturing apparatus therefor.

  Generally, when an electric wire is used for electrical wiring, connection terminals are attached to both ends of the electric wire. Conventionally, crimp terminals are frequently used as this type of connection terminal. The crimp terminal includes a cylindrical or U-shaped crimp barrel (barrel) into which a given electric wire can be inserted or attached, and a round or tip-open tongue extending in the longitudinal direction from one end of the crimp barrel. Are integrated. One end of the electric wire is connected to the crimping barrel by crimping, and the tongue is attached to a terminal board or the like with a bolt. Generally, the crimp terminal is made of a copper-based metal and may be tin-plated to prevent corrosion.

  On the other hand, copper wires, particularly coated copper wires, are often used as electric wires regardless of whether they are single wires or multi-wires (multi-core). When connecting the coated copper wire to the crimp terminal, it is necessary to remove the insulating coating from the surface of the copper wire, and fusing processing is performed in a mass production factory of the terminal connection structure.

  In this type of fusing process, a crimping body of a crimping terminal mounted so as to wrap one end of a coated copper wire is sandwiched between a pair of electrodes and pressurized, and a current flows between the two electrodes. Then, the insulation film of the coated copper wire is pushed out and removed by the Joule heat generated in the crimping cylinder part, the copper wire is exposed from inside, and the conductive state is established between the crimping cylinder part and the copper wire, and the copper wire becomes Joule. It softens with heat and is in close contact with the crimping cylinder and solid phase bonded. Furthermore, the copper wire is caulked by the pressure-bonding body, and the bonding strength is further increased. In such fusing processing, heating is performed at a temperature of 700 ° C. to 900 ° C. in order to quickly soften the copper wire in the crimping body.

  By the way, in recent years, the use of aluminum wires (aluminum wires) has been studied for the purpose of reducing the weight and reducing the cost of wires for motor vehicles (particularly hybrid vehicles and electric vehicles) and motor wires (windings). . If the copper wire is replaced with an aluminum wire, a weight reduction of about 35% can be achieved when the same current flows. However, since the aluminum wire and the crimp terminal are made of different materials and have an oxide film on the surface of the aluminum wire, it is difficult to obtain a physically and electrically stable terminal connection structure even by fusing. For this reason, the replacement of the copper wire with the aluminum wire has not progressed.

  Therefore, recently, replacement of copper wires with copper clad aluminum electric wires has been studied. A copper clad aluminum electric wire is a composite electric wire having an aluminum core (core wire) and a copper clad layer, and is considerably lighter in weight than a copper wire, and is about half as cheap as a copper wire. .

JP-A-61-199575 JP 2010-110790 A

  When the copper clad aluminum electric wire is also used as an electric wire for an automobile, for example, for electrical wiring, connection terminals such as crimp terminals are attached to both ends thereof. The appearance of the copper clad aluminum wire is the same as that of the copper wire. At first glance, the conventional fusing process used to connect the conventional copper wire and the crimp terminal is also applied to the connection between the copper clad aluminum wire and the crimp terminal. It can be used.

  However, when the present inventor tried in an experiment, a conventional fusing process was applied to the connection between the copper clad aluminum wire and the crimp terminal, and heat was applied at a temperature of 700 ° C. to 900 ° C. in order to soften the copper in the clad layer. When caulking, it was found that the aluminum in the core melted and ejected, and the thermocompression bonding was not successful. Moreover, it was found that the molten aluminum forms an alloy with the copper of the clad layer and causes the formation of an oxide film and corrosion, resulting in poor electrical characteristics. In particular, it has been found that the above-mentioned problems are remarkably exposed in a multi-core copper clad aluminum electric wire composed of a large number of thin copper clad aluminum strands.

  Rather, the development of terminal connection technology that connects copper clad aluminum wires to crimp terminals by soldering has become the mainstream, taking advantage of the fact that the clad layer of copper clad aluminum wires is easy to solder. . However, since the copper clad layer is thin (usually 10 μm or less), it is easily eroded by solder (so-called copper erosion). When the copper clad layer is broken and the aluminum core is exposed, the solder is not bonded to the aluminum, so that the soldering joint strength and electrical conductivity are lowered. In particular, in the multi-core type copper clad aluminum electric wire, it is immersed in a solder bath and solder is poured between the strands, but such a soldering method not only requires a long processing time, Even if the gaps between the strands are filled with solder, the problem will not be solved because copper erosion tends to occur.

  The present invention has been made in view of the above-mentioned problems of the prior art, and a terminal connection structure capable of stably and reliably obtaining good physical and electrical characteristics between a copper clad aluminum electric wire and a crimp terminal, and The manufacturing method and the manufacturing apparatus are provided.

A manufacturing method of a terminal connection structure in the present invention is a method for manufacturing a terminal connection structure in which a copper clad aluminum electric wire including a plurality of copper clad aluminum wires is connected to a crimping body of a crimp terminal by thermocompression bonding. A first step of mounting the copper clad aluminum wire so as to be wrapped in the crimp body of the crimp terminal, and a first electrode facing the crimp body enclosing the copper clad aluminum wire. A second step of continuously applying a constant pressing force preset in one direction by being sandwiched between the second electrode, and the first pressing force while the pressing force is being applied to the pressure-bonding body. Inside the crimping cylinder so that the aluminum core and the copper clad layer of all the copper clad aluminum strands generate Joule heat themselves between the electrode and the second electrode A third step of passing an electric current across the entire area and connecting the copper-clad aluminum wire to the crimping cylinder by thermal caulking, and measuring or monitoring the temperature of the crimping cylinder, and measuring the processing temperature of the thermal caulking A fourth step of controlling or managing within a predetermined temperature range, and in the third step, the crimping barrel portion of the crimp terminal is interposed between the first electrode and the second electrode. In the crimped body deformed flat, the aluminum core is deformed into a polygonal cross-section for all the copper-clad aluminum strands, and the aluminum core is crushed without crushing the copper clad layer. The copper is deformed into a polygonal cross-section following the deformation of the copper, and all the side surfaces of the polygonal cross-section are deformed into a polygonal cross-section of the other copper clad aluminum strand adjacent thereto. Rudd layer one side or to the inner surface and the solid-phase bonding of the crimp barrel of the predetermined temperature range is below 400 ° C. or higher 660 ° C..

According to the above method of the present invention, in fusing processing for connecting a copper clad aluminum electric wire including a plurality of copper clad aluminum strands and a crimp terminal, the temperature of heat caulking is set to 400 ° C. or higher and lower than 600 ° C. (more preferably 450 ° C. By controlling or managing within the range of ℃ ~ 550 ℃), by deforming the crimping cylinder enclosing the copper clad aluminum electric wire of the crimping terminal flat between the first electrode and the second electrode, all closes the gap between the copper-clad aluminum element wire, and all of the copper clad without crushing the copper clad aluminum element wire and a polygonal cross section of each copper clad aluminum element wires without breaking inside of the crimp barrel by plastically deforming, obtaining excellent terminal connection structure of the physical strength and electrical conductivity between the copper clad aluminum wire and the crimping terminal that the It can be.

In particular, according to the above method of the present invention, the aluminum core part of the aluminum core part and the copper clad layer constituting each copper clad aluminum element wire inside the crimping cylinder part has a polygonal cross section without melting. The copper clad layer is deformed into a polygonal cross-section following the deformation of the aluminum core while maintaining a certain thickness without being crushed, and all the side faces of the cross-sectional polygon are adjacent to it. copper clad aluminum element wire of being solid phase bonded to the inner surface of one side or the crimp barrel of the copper clad layer which is deformed polygonal cross section, it is possible to obtain a terminal connection structure. In this terminal connection structure, good electrical characteristics with low resistance can be obtained for all of the many copper-clad aluminum wires, and as a result, the copper-clad aluminum wire as a whole has good electrical characteristics with low resistance. can get.

According to the terminal connection structure and a manufacturing method thereof of the present invention, by having the configuration described above, stable reliably getting good physical and electrical properties between the crimp terminal and the copper clad aluminum wire Can do.

It is a perspective view which shows the structure of the crimp terminal and copper clad aluminum electric wire which form a terminal connection structure in embodiment. It is sectional drawing which shows the structure of the copper clad aluminum strand which comprises a copper clad aluminum electric wire. It is a perspective view which shows the state by which the one end part of the copper clad aluminum electric wire was mounted | worn with the crimping | compression-bonding trunk | drum of the said crimp terminal before the fusing process. It is a perspective view which shows the external appearance of the terminal connection structure after a fusing process is performed. It is a block diagram which shows the structure of the fusing apparatus in embodiment. It is a figure which expands and shows the structure inside the crimping | compression-bonding trunk | drum before a fusing process is performed. It is a wave form diagram of each part for demonstrating the effect | action of the fusing process of embodiment. It is a figure which shows typically the cross-sectional structure of the terminal connection structure obtained in the fusing process of embodiment. It is a figure which shows the cross-section of the terminal connection structure obtained in embodiment with a photograph. It is a flowchart figure which shows the procedure of the fusing process containing the 1st method for satisfy | filling the temperature conditions of heat caulking in embodiment. It is a flowchart figure which shows the procedure of the fusing process containing the 2nd method for satisfy | filling the temperature conditions of heat caulking in embodiment. It is a flowchart figure which shows the procedure of the fusing process containing the 2nd method for satisfy | filling the temperature conditions of heat caulking in embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[Configuration of crimp terminal and copper clad aluminum wire]

  In FIG. 1, the structure of the crimp terminal and copper clad aluminum electric wire which form a terminal connection structure in this embodiment is shown.

  The crimp terminal 10 is made of copper-based metal such as pure copper, copper alloy, or plated copper, and has a cylindrical crimp body (barrel portion) 12 and a round tongue extending from one end of the crimp body 12 in the longitudinal direction. 14 integrally. The crimping | compression-bonding trunk | drum 12 is connected with the one end part of the copper clad aluminum electric wire 16 by thermocompression bonding so that it may mention later. The tongue 14 is attached to a terminal board (not shown) or the like by passing a bolt (not shown) through a hole in the ring in the form of electric wiring.

  The copper clad aluminum electric wire 16 is a multi-wire or multi-core electric wire, and a plurality of, for example, 50 to 150 thin copper clad aluminum strands 18 having a diameter of 0.15 to 0.3 mm are twisted together. The copper clad aluminum electric wire 16 may be bundled with an insulating coating (exterior) such as vinyl except for both ends to which the crimp terminal 10 is attached.

  As shown in FIG. 2, the copper-clad aluminum element wire 18 includes an aluminum core portion (core wire) 20, a copper clad layer 22 covering the aluminum core portion 20, and an insulating coating covering the copper clad layer 22. 24. Here, the copper clad layer 22 is made of, for example, oxygen-free copper, usually has a thickness of 10 μm or less and an area ratio (volume ratio) of 10 to 15%, and is metal-bonded to the aluminum core 20 and peeled off. There is no. The insulating coating 24 is made of a resin and has a thickness of, for example, 50 to 100 μm.

In this embodiment, when the copper clad aluminum wire 16 is connected to the crimp terminal 10, before performing the fusing process, as shown in FIG. 3, the copper clad aluminum wire 16 is connected to the crimp body 12 of the crimp terminal 10. Insert (attach) one end. And the copper clad aluminum electric wire 16 is connected to the crimping | compression-bonding trunk | drum 12 by a fusing process or heat crimping using the fusing apparatus (FIG. 5) mentioned later. As a result, as shown in FIG. 4, in appearance, the crimping body 12 is deformed flat, and the copper clad aluminum electric wire 16 is caulked. As will be described later, all the copper-clad aluminum strands 18 are plastically deformed into a polygonal cross section without forming a gap, and between the adjacent strands 18 and between the adjacent strands 18, as will be described later. A good physical and electrical connection is formed between the crimping cylinder 12 and the crimping cylinder 12.

[Configuration of fusing device]

  FIG. 5 shows the configuration of the fusing device in this embodiment. The fusing apparatus includes an upper electrode 30 and a lower electrode 32 that are arranged so as to be relatively movable so as to be opposed to each other so that the workpiece W can be sandwiched in the vertical direction, and through both the electrodes 30, 32. A pressurizing device 34 that applies pressure for heat caulking to the work W, a power supply unit 36 that supplies heat caulking current to the work W via both electrodes 30 and 32, and the temperature of the work W A radiation thermometer 38 that measures the temperature in a non-contact manner, and a control unit 40 that controls the entire apparatus or each unit, in particular, the pressurizing device 34 and the power supply unit 36.

  More specifically, the lower electrode 32 is supported by a base 42 fixed to the floor. The upper electrode 30 is coupled to a pressurizing device 34 and is pressed against the lower electrode 32 with a desired pressure across the workpiece W. The pressurizing device 34 has, for example, an air cylinder as a pressure generating source. The power supply circuit 36 may be either an AC type or a DC type, and has a power supply circuit that can supply required power or current to the load side, and a switching mechanism that can perform on / off or variable control of the output current. Preferably, an inverter circuit is incorporated. The radiation thermometer 38 includes an infrared lens, a photoelectric conversion element, a temperature measurement calculation circuit, and the like, detects the amount of infrared energy emitted from the workpiece W, and performs a predetermined calculation from the detected amount of infrared energy. The temperature measurement value of the workpiece W is obtained. Usually, the radiation thermometer 38 is disposed at the same height as the workpiece W and beside the electrodes 30 and 32, and the crimping body 12 of the crimp terminal 10 is used as a temperature measurement point.

  The control unit 40 includes a CPU (microcomputer) and controls the entire apparatus or each unit according to various programs (software) stored in the memory. Especially in the fusing process of this embodiment, the radiation thermometer 38 It has a function of controlling or managing the processing temperature of heat caulking based on the output signal. Further, the main control unit 40 exchanges information (setting values, monitor information, etc.) with users (operators, maintenance personnel, etc.) via the input unit and display unit of the touch panel 44.

In this embodiment, the workpiece W is inserted (attached) into the crimped copper portion 12 of the crimp terminal 10 and the crimped copper portion 12 of the copper clad aluminum wire 16 as shown in FIGS. 3 and 5. It consists of. FIG. 6 shows an enlarged structure inside the crimp terminal 12 before the fusing process is performed. As shown in the drawing, the individual copper clad aluminum wires 18 constituting the copper clad aluminum wire 16 are only twisted together in the crimp terminal portion 12, and in a cross section orthogonal to the axial direction of the wire. Adjacent strands 18 are locally in contact with each other at almost points via insulating coatings 24 (not shown in FIG. 6) of the respective surface layer portions, and there are many gaps G.

[Function of fusing processing]

  Below, the fusing method of this embodiment which can be implemented from this fusing apparatus is demonstrated about FIGS. 7-12.

First, the crimping body 12 (workpiece W) of the crimp terminal 10 enclosing one end of the copper clad aluminum wire 16 is placed on the lower electrode 32 by a handling operation of the robot or a manual operation of the operator. Is done. Immediately after that, the control unit 40 operates the pressurizing device 34 to lower the upper electrode 30 and apply it to the upper surface of the pressure-bonding body 12, and apply a predetermined pressure F to the workpiece W via both electrodes 32 and 34. _S is continuously added ((a) of FIG. 7). The applied pressure F _S varies depending on the material (hardness) of the crimp terminal 10 and the wire diameter (thickness) of the copper clad aluminum wire 16. If the applied pressure F _S is too large, the base material may be destroyed. However, if the applied pressure F _S is too small, the gap G between the strands 18 is not lost in the crimping body 12. Usually, the pressing force F _S is selected within the range of 50 to 200 kg, preferably within the range of 120 to 160 kg.

  The control unit 40 operates the power supply unit 36 while applying a constant pressure F to the workpiece W as described above, and energizes the workpiece W via both electrodes 32 and 34 ( 7 (b) The energization time varies depending on the material of the crimp terminal 10 and the wire diameter (thickness) of the copper clad aluminum electric wire 16 but usually requires 0.5 seconds or more, for example, 2 seconds. Selected before and after.

  In this case, initially, a current flows only between the crimping cylinder 12 between the electrodes 32 and 34, and the crimping cylinder 12 generates Joule heat. Then, in each copper clad aluminum element wire 18 in the crimping cylinder 12, the insulating coating 24 is melted and extruded (peeled) by heating and pressurization received from the crimping cylinder 12, and the copper cladding layer 22 is exposed. To do. Thereafter, a current flows between the electrodes 32 and 34 across the crimping body 12 and the copper clad aluminum electric wire 16 (element wire 18). Thereby, in each strand 18, the copper clad layer 22 and the aluminum core part 20 receive heating and pressurization from the surroundings while generating Joule heat by themselves. Since both the copper clad layer 22 and the aluminum core part 20 have high thermal conductivity and the thermal conductivity of the crimping cylinder part 12 is also high, the temperature of the entire area within the crimping cylinder part 12, that is, all the copper clad aluminum strands 18 is uniform. The temperature of the crimping body 12 is substantially the same as the temperature of each strand 18.

  As a result of diligent investigations through many experiments, the present inventor has found that the temperature of the heat caulking is 400 ° C. or higher in the fusing process for connecting the copper clad aluminum wire 16 and the crimp terminal 10 as described above. 8 (schematic diagram) and FIG. 9 (cross-sectional photographs) on the inner side of the crimping barrel 12 by controlling or managing it within a range of 660 ° C. (more preferably 450 ° C. to 550 ° C.), which is the melting temperature of aluminum It was found that the thermocompression bonding of the cross-sectional structure as shown in FIG. 2) was obtained, and that the physical and electrical characteristics of the processed product (terminal connection structure) could be reliably and reliably guaranteed with good reproducibility.

In the cross-sectional structures shown in FIGS. 8 and 9, the aluminum core portion 20 is melted out of the aluminum core portion 20 and the copper clad layer 22 constituting each copper clad aluminum element wire 18 inside the crimping barrel portion 12. The copper clad layer 22 follows the deformation of the aluminum core 20 while maintaining a constant thickness without being crushed, and is deformed into a polygon (substantially unequal sides). It is deformed to a pentagon. The copper clad layer 22 has all the side faces of the cross-sectional polygon (substantially unequal sides pentagons) deformed into the cross-section polygon (substantially unequal sides pentagons) of other strands 18 adjacent thereto. Are solid- phase bonded in close contact with one side surface or the inner side surface of the pressure-bonding body 12. The gap G existing between the strands 18 and between the strands 18 and the inner surface of the crimping body 12 before the fusing process is almost completely eliminated.

  A terminal having a cross-sectional shape as shown in FIGS. 8 and 9 using the copper clad aluminum wire 16 formed by twisting 144 copper clad aluminum strands 18 having a diameter of 0.16 mm. In the connection structure, when the electrical conductivity from the other end to the tongue portion 14 of the crimp terminal 10 was examined one by one for each copper clad aluminum strand 18, all 144 copper clad aluminum strands 18 had low resistance. Good electrical continuity was obtained.

Theoretically, when the processing temperature of heat caulking is in the range of 400 ° C. or higher and lower than 660 ° C., the aluminum core 20 is softened without being melted and plastically deformed because it is lower than the melting point of aluminum (660 ° C.). . On the other hand, the copper clad layer 22 does not melt or soften. However, since the copper clad layer 22 is thin like a copper foil (usually 10 μm or less), it follows the deformation of the aluminum core portion 20 and keeps its original thickness without being crushed and torn without breaking and having the same shape, that is, a polygonal cross section. Transforms into Thereby, all the strands 18 are solid- phase bonded to the other adjacent strands 18 via the respective copper clad layers 22. Further, all the strands 18 adjacent to the inner side surface of the crimping cylinder 12 are solid- phase bonded to the inner side surface of the crimping cylinder 12 via the respective copper clad layers 22.

  However, although aluminum softens at 400 ° C. or higher, a higher temperature is needed to quickly and sufficiently soften the aluminum core 20 so that no gaps remain between the copper clad aluminum strands 18 in heat caulking. preferable. According to the experiment of the present invention, it was found that stable bonding can be achieved without gaps at 450 ° C. or higher. Moreover, if the degree of softening is too large even if the aluminum core 20 is not melted, the follow-up deformation of the copper clad layer 22 may be insufficient, or the aluminum core 20 may be eluted. According to the experiments of the present inventors, it was found that extremely stable bonding can be achieved at 550 ° C. or lower. As described above, in order to obtain a terminal connection structure having excellent physical and electrical characteristics as shown in FIGS. 8 and 9 inside the crimping body 12 with high reproducibility and reliability, the temperature of the heat caulking is set to 450. Experiments have confirmed that it is preferable to control and manage the temperature within a range of from 0C to 550C.

In the fusing device of this embodiment, the control unit 40 performs at least one of the following three types of control or management methods MD1, MD2, and MD3 in order to satisfy the above-described thermal caulking temperature condition. It is like that.

[First Method for Satisfying Thermal Caulking Temperature Conditions]

The first method MD1 is executed in the fusing processing procedure as shown in FIG. 10 (steps S ₄ , S ₅ , S ₆ , S ₉ ). It is preferably used when the waveform changes as shown in (c).

In this method MD1, the control unit 40 sets in advance a desired energization time T _E (t _{s to} t _e ) suitable for fusing processing for manufacturing the terminal connection structure through the touch panel 44, and this energization. A desired monitoring period T _E excluding _a certain time (t _{a to} t _b ) immediately after the start of energization is set in the time T _E (t _{s to} t _e ), and further, the predetermined temperature range (450 ° C. to 550 ° C.) is set. The desired upper limit monitoring value S _U (for example, 550 ° C.) and the lower limit monitoring value S _L (for example, 450 ° C.) are set.

When energization of the fusing process is started, the control unit 40 takes in the output signal of the radiation thermometer 38, obtains a measured value of the temperature of the crimping cylinder 12, that is, a machining temperature, and calculates the measured temperature value of both. monitoring value S _U, S _L compared to determine during monitoring period T _E processing temperature (measured value) of the two monitoring value S _U, whether or not fall within the S _L (step S _4, S ₅ , S ₆ ). Then, after completion of the energization time T _E, and outputs the determination result via the touch panel 44 (step S _9).

That is, when the processing temperature (measured value) of the heat caulking stays between the lower limit monitoring value S _L and the upper limit monitoring value S _U throughout the monitoring period T _E , the crimping cylinder portion 12 has FIG. Further, it is considered that a cross-sectional structure as shown in FIG. 9 is obtained, and it is determined that the terminal connection structure obtained by this fusing process is a non-defective product. However, if the processing temperature (measured value) of the thermal caulking divides the lower limit monitoring value S _L even once or exceeds the upper limit monitoring value S _U during the monitoring period T _E , 8 and FIG. 9 are regarded as having no cross-sectional structure, and the terminal connection structure obtained by this fusing process is determined to be defective.

[Second Method for Satisfying Thermal Caulking Temperature Conditions]

The second method MD2 is in the fusing processing procedure as shown in FIG. 11 is performed in (step _{S 14, S 15, S 16} ), processing temperature of the hot crimping during energization of FIG 7, for example (d) It is preferably used when the waveform changes as shown in FIG.

In this method MD2, the control unit 40 sets a desired reference temperature S _A (for example, 5400 ° C.) within the predetermined temperature range (450 ° C. to 550 ° C.) through the touch panel 44 in advance. The energization time may not be set to a desired value, but it is preferable to set the maximum or limit energization time _TMAX .

When energization of the fusing process is started, the control unit 40 takes in an output signal of the radiation thermometer 38, obtains a measured value of the temperature of the crimping cylinder 12, that is, a machining temperature, and the measured temperature value is a reference value. Whether or not the temperature S _A is reached is inspected continuously or at regular time intervals (steps S _{14 to} S ₁₇ ), and the processing temperature (measured value) of the heat caulking is used as a reference before the maximum energization time T _MAX elapses. When the temperature S _A is reached (step S ₁₆ ), energization is stopped at that time (t _c ) (step S ₁₈ ). In this case, it is considered that the cross-sectional structure as shown in FIGS. 8 and 9 is obtained in the crimping cylinder 12, and the determination result that the terminal connection structure obtained by the fusing process is a non-defective product is obtained. Output (step S ₂₀ ).

However, if the heat staking of the processing temperature (measured value) of the maximum energization time T _MAX without reaching the reference temperature S _A has elapsed stops energization in (Step S _15), which point (t _m) (Step S ₁₈ ). In this case, it is considered that the cross-sectional structure as shown in FIGS. 8 and 9 is not obtained in the crimping cylinder 12, and the terminal connection structure obtained by the fusing process is determined to be defective. The result is output (step S ₂₀ ).

[Third method for satisfying temperature condition of heat caulking]

The third method MD3, which runs in the fusing processing procedure shown in FIG. 12 (step S ₃₄ to S _37), as shown in (e) of the processing temperature of the thermal caulking while power eg 7 Force control to correct waveform.

In this method MD3, the control unit 40 sets in advance the desired energization time T _E (t _{s to} t _e ) suitable for fusing processing for manufacturing the terminal connection structure through the touch panel 44, and the predetermined setting the temperature range (450 ° C. to 550 ° C.) the desired reference temperature S _B for example 500 ° C. in a).

When energization of the fusing process is started, the control unit 40 takes in the output signal of the radiation thermometer 38, obtains the measured value of the temperature of the crimping cylinder 12, that is, the thermal crimping temperature, and the measured temperature value. The current value of the current flowing between the electrodes 30 and 32 through the power supply unit 36 is controlled by the feedback control method so that the value matches or approximates the reference temperature S _B (steps S _{34 to} S ₃₇ ).

In this case, there are two types of feedback control methods. One method is an on / off control method. That is, when the heat staking of the processing temperature (measured value) exceeds the reference temperature S _B is temporarily de-energized and resumes energization when thermal caulking processing temperatures (measured value) obtained by dividing the reference temperature S _B . Then, continue the on-off operation of the power supply until the end of the current time T _E.

Another method is to compare the processing temperature (measured value) of thermal caulking with the reference temperature S _B for each cycle of 10 kHz to 100 kHz, for example, to obtain a comparison error, and to make the comparison error close to zero as follows: This is a method of variably controlling the current value of the current flowing in a cycle using a high-speed switching means, and can be suitably implemented when an inverter circuit is provided.

According to the third method MD3, the processing temperature of the heat caulking is forcibly controlled to the vicinity of the reference temperature S _B through the energization time T _E , so that a determination function is not particularly required in the control unit 40. That is, unless a special error occurs, it is considered that the cross section structure shown in FIGS. 8 and 9 is obtained in the crimping cylinder 12 by the worker or the manager, and is obtained by this fusing process. It may be judged that the terminal connection structure is a non-defective product.

[Other Embodiments or Modifications]

  As mentioned above, although preferred embodiment of this invention was described, embodiment mentioned above does not limit this invention. Those skilled in the art can make various modifications and changes in specific embodiments without departing from the technical idea and technical scope of the present invention.

  For example, in the said embodiment, the crimping | compression-bonding trunk | drum 12 of the crimp terminal 10 was formed in the cylindrical shape. However, the crimping | compression-bonding trunk | drum 12 may be formed in the cross-sectional U shape of a horizontal direction, for example. The tongue portion 14 of the crimp terminal 10 is not limited to the ring shape, and may be a type that opens in a U shape or a Y shape. Moreover, as a material of the crimping | compression-bonding trunk | drum 12, iron-type metals other than copper type | system | group are also possible.

  In the copper-clad aluminum electric wire 16, the cross-sectional shape of the copper-clad aluminum wire 18 is arbitrary, and is not limited to a circle but may be a rectangle. Moreover, the copper clad aluminum electric wire 16 is not limited to the multi-wire (multi-core) type, but may be a single-wire type.

  In the fusing process in the embodiment, the above-described radiation thermometer 38 is most preferable as the temperature sensor for measuring the processing temperature of the heat caulking. However, other non-contact temperature sensors can also be used, and contact-type temperature sensors (for example, thermocouples) can also be used.

DESCRIPTION OF SYMBOLS 10 Crimp terminal 12 Crimp body 16 Copper clad aluminum electric wire 18 Copper clad aluminum strand 20 Aluminum core part 22 Copper clad layer 24 Insulation coating 30 Upper electrode 32 Lower electrode 34 Pressurizing device 36 Power supply part 38 Radiation thermometer 40 Control part 44 Touch panel

Claims (8)

A method for producing a terminal connection structure in which a copper clad aluminum wire including a plurality of copper clad aluminum strands is connected to a crimping body of a crimp terminal by thermocompression bonding,
A first step of mounting the copper clad aluminum electric wire so as to be wrapped in the crimping body of the crimp terminal;
A second step of continuously applying a predetermined pressing force in one direction by sandwiching the crimping cylinder enclosing the copper clad aluminum electric wire between the first electrode and the second electrode facing each other; When,
While the pressurizing force is applied to the pressure-bonding body, the aluminum core portion and the copper clad layer of all the copper-clad aluminum strands between the first electrode and the second electrode themselves are joules. Passing a current across the entire area of the crimping cylinder so as to generate heat, and connecting the copper-clad aluminum wire to the crimping cylinder by thermal caulking;
Measuring or monitoring the temperature of the crimping cylinder, and controlling or managing the processing temperature of the thermal caulking within a predetermined temperature range, and
In the third step, the crimping drum portion of the crimping terminal is deformed flat between the first electrode and the second electrode, and all the copper is contained in the flattened crimp drum portion. For the clad aluminum strand, the aluminum core is deformed into a polygonal cross-section, and the copper clad layer is deformed into a polygonal cross-section following the deformation of the aluminum core without crushing the copper clad layer. A solid phase bonding of one side surface of the copper clad layer that is deformed into a polygonal cross-section of another copper clad aluminum strand adjacent thereto or the inner side surface of the crimping cylinder portion thereof,
The predetermined temperature range is 400 ° C. or more and less than 660 ° C.,
Manufacturing method of terminal connection structure. The method for manufacturing a terminal connection structure according to claim 1, wherein the predetermined temperature range is 450 ° C. or higher and lower than 550 ° C. The fourth step includes
Setting a desired monitoring period excluding a certain time immediately after the start of energization in the energization time during which the current flows between the first electrode and the second electrode;
Setting a desired upper limit monitoring value and a lower limit monitoring value within the predetermined temperature range; and
Monitoring whether or not the measured temperature of the crimping cylinder is kept between the lower limit monitoring value and the upper limit monitoring value throughout the monitoring period, and outputting the monitoring result after the end of the energization time. The manufacturing method of the terminal connection structure of Claim 1 or Claim 2 containing. The fourth step includes
Setting a desired reference temperature within the predetermined temperature range;
The method for manufacturing a terminal connection structure according to claim 1, further comprising: stopping the current when a measured temperature of the crimping cylinder part reaches the reference temperature. The fourth step includes
Setting a desired reference temperature within the predetermined temperature range;
A step of controlling the current value of the current by a feedback control method so that the measured temperature of the crimping cylinder matches or approximates the reference temperature through the energization time during which the current flows except for the rise time immediately after the start of energization; including,
The manufacturing method of the terminal connection structure of Claim 1 or Claim 2 . The method for manufacturing a terminal connection structure according to any one of claims 1 to 5 , wherein the fourth step measures the temperature of the crimping barrel using a non-contact temperature sensor. The said temperature sensor is arrange | positioned beside the said 1st and 2nd electrode, and manufactures the terminal connection structure of Claim 4 which uses the said crimping | compression-bonding cylinder part which has wrapped the said copper clad aluminum electric wire as a temperature measurement point. Method. The process according to any one of claims 1 to 7, in terminal connection structure in which a plurality of copper-clad aluminum element wire composing the copper clad aluminum wire is connected by thermocompression bonding barrel of the crimp terminal There,
Of the aluminum core portion and the copper clad layer constituting each of the copper clad aluminum strands inside the crimping barrel portion, the aluminum core portion is not melted and deformed into a polygonal cross section, and the copper clad The layer is deformed into a polygonal cross-section following the deformation of the aluminum core portion while maintaining a constant thickness without being crushed, and all the side surfaces of the cross-sectional polygon are adjacent to the other copper-clad aluminum element adjacent thereto. one aspect or the crimp barrel of being solid phase bonded to the inner surface, the terminal connection structure of the copper clad layer which is deformed into polygonal section of the line.