WO2020179855A1

WO2020179855A1 - Conduction diffusion bonding device

Info

Publication number: WO2020179855A1
Application number: PCT/JP2020/009289
Authority: WO
Inventors: 水野芳伸; 中村武; 伊藤誠
Original assignee: Ｅｃｏ－Ａ株式会社
Priority date: 2019-03-05
Filing date: 2020-03-05
Publication date: 2020-09-10
Also published as: CN113543919A; JPWO2020179855A1

Abstract

The purpose of the present invention is to provide a conduction diffusion bonding device enabling fine control of a power source output and making it possible to finely manage the temperature of a member to be bonded. A conduction diffusion bonding device 10 for bonding a plurality of members 1 to be bonded, which abut at bonding surfaces S, by energizing the members, wherein the current diffusion bonding device 10 is provided with: a plurality of electrodes 2 for energizing the plurality of members 1 to be bonded; a power source 3 that can continuously modify the output applied to the plurality of electrodes 2; a temperature information provision unit 4 for providing temperature information about the members 1 to be bonded or the electrodes 2; and an output control unit 5 for controlling the output of the power source 3 with an upslope on the basis of the temperature information from the temperature information provision unit 4.

Description

Energization diffusion joining device

The present invention relates to a current diffusion bonding device for bonding members to be bonded together.

Conventionally, there is known an energization diffusion bonding in which a metal member is heated in a solid phase temperature range and bonded by an atomic diffusion phenomenon (see, for example, Patent Document 1). The electric current diffusion bonding is suitable for bonding the same kind of material or different kinds of material made of a hard-to-weld metal material.

In current diffusion bonding, a member to be joined is sandwiched between electrodes, and a current (direct current or pulse) is passed between the electrodes while pressure is applied to the joining surface via the electrodes by a pressure mechanism. To heat. Then, in the solid phase temperature range equal to or lower than the melting temperature of the member to be joined, the joint surface is brought into close contact due to softening and deformation of the material, and the joint is joined by the solid phase diffusion phenomenon.

JP 2012-6068

Here, in the current diffusion bonding, it is necessary to make the current density flowing through the bonding surface of the member to be bonded uniform and the temperature of the bonding surface uniform. However, in the conventional pulse step response, even if the current value is narrowed down to some extent, the location where the current is concentrated occurs unspecified. Since the temperature at the location where the current is concentrated rises sharply, the bonding state at that location rapidly becomes a liquid phase bond, and the bonding state at the bonding interface becomes non-uniform, leading to variations in bonding strength. In current diffusion bonding, it is necessary to maintain the optimum bonding temperature condition for a certain time from the viewpoint of accelerating the movement of atoms in the solid phase region. Therefore, in the current diffusion bonding, the temperature control of the member to be joined is very important, and the control of the electric power energy converted into heat by the member to be joined is important.

However, in general resistance welding, temperature is a secondary factor depending on the amount of electric power supplied (current x time), and is rarely controlled primary. The conventional method has a problem in that the variation in the bonding strength is large because ON/OFF control is not a precise control even when the current is supplied or controlled for a certain period of time.

In addition, in the current diffusion bonding, the load applied to the bonding surface is also an important factor of the bonding strength, and in order to keep the load constant, it is necessary to take measures against the thermal expansion of the members to be bonded during heat generation. Regarding this, Patent Document 1 also describes measures against thermal expansion of the member to be joined. However, in ON/OFF temperature control, since stress is repeatedly applied to the members to be joined, these measures alone are insufficient.

Therefore, an object of the present invention is to provide an energization diffusion joining device capable of controlling the output of a power source more precisely and enabling precise temperature control of a member to be joined.

In order to achieve the above object, the energization diffusion joining device of the present invention energizes and joins a plurality of abutted members to be joined, and conducts electricity to the plurality of members to be joined. A plurality of electrodes for making the electrodes, a power source capable of continuously changing the output applied to the plurality of electrodes, a temperature information providing unit that provides temperature information of the member to be joined or the electrodes, and the temperature information providing unit. And an output control unit that controls the output of the power supply with an up-slope based on the temperature information from.

In this case, a voltage drop detecting means capable of detecting a voltage drop on the joint surface by supplying a constant current to the jointed member may be provided. Further, the output control unit may control the output of the power source based on the voltage drop detected by the voltage drop detection means.

Further, the temperature information providing unit may be a temperature sensor that detects the temperature information of the member to be joined or the electrode, or the temperature information storage in which the temperature information of the member to be joined or the electrode is stored. It may be a department.

Further, the current diffusion bonding apparatus of the present invention includes a pressurizing unit for applying pressure to the bonding surface of the members to be bonded.

The energization diffusion joining device of the present invention can control a more precise power supply, enable precise temperature control or pressure control of the member to be joined, and can perform joining with strong joining strength and small variation.

It is a partial cross section figure which shows the electrical diffusion bonding apparatus of this invention. It is a block diagram for explaining an output control unit according to the present invention. It is a block diagram for explaining a pressure control part concerning the present invention.

The electric diffusion bonding apparatus 10 of the present invention will be described with reference to FIGS. 1 to 3. The energization diffusion joining device 10 of the present invention energizes and joins a plurality of members 1 to be joined with the joining surface S, and includes an electrode 2, a power source 3, a temperature information providing unit 4, and the like. It is mainly configured with the output control unit 5.

Here, the member 1 to be joined is a member to be joined on the joint surface S, and any material, shape, etc. may be used as long as it can be energized. Materials include steel materials such as stainless steel, non-ferrous metals such as copper, aluminum and zinc, metal materials such as various alloys including aluminum, nickel, chromium, titanium and copper, as well as ceramics having high temperature conductivity. , Semiconductors, non-ferrous materials such as single crystal materials. Further, the member 1 to be joined may be made of the same material or a different material. Further, examples of the shape include a pipe shape, a bulk shape, a thick plate shape, and a thin plate shape, and arbitrary processing such as groove processing and hole forming processing may be performed. The joining surface S is preferably flat, but may be a curved surface, for example, a curved surface having the same curvature, as long as no gap is formed. Further, the joint surface S is preferably a mirror surface, but may be a rough surface.

The electrode 2 is for conducting electricity output from the power source 3 to the plurality of members 1 to be joined. The energization diffusion joining device 10 may be provided with at least two electrodes 2 in order to conduct electricity to the member 1 to be joined, and is provided, for example, at a portion of the member 1 to be joined that faces the joint surface S. .. Of course, three or more electrodes 2 may be provided depending on the material and shape of the member to be joined 1. The electrode 2 may be made of any material as long as electricity can be conducted through the member 1 to be joined, and for example, copper, molybdenum, tungsten, or the like can be used. Further, the electrode 2 is connected to the power source 3 via the cable 31.

The power supply 3 is for outputting electric power to a plurality of electrodes 2. The power supply 3 may be any power source 3 as long as the outputs applied to the plurality of electrodes 2 can be continuously changed, and for example, a known inverter power supply can be used.

The temperature information providing unit 4 is for providing the output control unit 5 with the temperature information of the member to be joined 1 or the electrode 2. The temperature information means information on the temperature of the member 1 to be joined or the electrode 2, and may be the information as it is, or is converted from the temperature by calculation, for example, a voltage value that determines the voltage of the power supply 3. It may be information. As the temperature information providing unit 4, for example, a temperature sensor that detects the temperature of the member to be joined 1 or the electrode 2 can be used. The temperature sensor may be any one as long as it can detect the temperature of the joining member or the electrode 2. For example, a non-contact type sensor that detects the temperature in a non-contact manner such as an infrared radiation thermometer, or the joining member 1 or A contact type sensor such as a thermocouple that contacts the electrode 2 to detect the temperature may be used. It is also possible to use a non-contact type and a contact type together.

The output control unit 5 is for controlling the output of the power supply 3 with an upslope based on the temperature information from the temperature information providing unit 4. Conventionally, a constant current is supplied for a fixed time, or a constant current is supplied by ON/OFF control, so that the temperature at a location where the current is concentrated may rise rapidly. In this case, the bonding state of the bonding surface S becomes non-uniform, for example, the bonding state at the relevant portion becomes a liquid phase bond, which leads to variations in the bonding state. On the other hand, in the up-slope control, the current is gradually increased, so that sudden current concentration is suppressed and the temperature of the joint surface can be made uniform. Therefore, it becomes possible to grow a uniform diffusion layer on the bonding surface S, and the strength can be made uniform. Further, the output control unit 5 can continuously control the output of the power supply 3 in real time with an upslope based on the temperature information detected by the temperature sensor, and can enable precise temperature control of the member 1 to be joined. Therefore, it is possible to perform joining with high joining strength on the joining surface S between the joining members and with little variation. Further, since such continuous control can maintain the thermal expansion constant as compared with the ON / OFF control, the influence of the pressure fluctuation due to the thermal expansion can be reduced.

The output control unit 5 may be any as long as the output of the power supply 3 can be controlled by an upslope based on the temperature information from the temperature information providing unit 4, but for example, the CPU, ROM, RAM, I / O. The operation unit 51 and the display unit 52 that are electrically connected to each other can be used. Specifically, a known PID temperature controller such as a high speed sampling temperature controller can be used. It should be noted that the operation unit 51 is composed of various operation switches such as a start switch and a start switch, an input panel including a touch panel, and the like. The information input from the operation unit 51 is transmitted to the output control unit 5. Further, the display unit 52 receives information from the output control unit 5 based on the input to the output control unit 5 or the calculation result of the output control unit 5, and displays the information. Here, the display unit 52 is composed of a digital display panel, a lamp, and the like.

When the temperature information providing unit 4 described above acquires the temperature of the member 1 or the electrode 2 to be joined in real time using a temperature sensor and provides the output control unit 5 with the temperature information of the member 1 or the electrode 2 to be joined. Was explained. However, when the members 1 to be joined of the same material are joined in the same environment using the current-carrying diffusion joining device 10 of the present invention, the relationship between the elapsed time and the temperature of the members 1 to be joined or the electrode 2 has the same result. Therefore, if temperature information indicating the relationship between the elapsed time and the temperature of the member 1 or the electrode 2 is acquired in advance, the temperature information can be provided without using the temperature sensor. Therefore, the temperature information providing unit 4 may be a temperature information storage unit that stores temperature information indicating the relationship between the elapsed time of the member to be joined 1 or the electrode 2 and the temperature of the member to be joined 1 or the electrode 2. Accordingly, the output control unit 5 can control the output of the power supply 3 based on the temperature information stored in the temperature information storage unit. The temperature information storage may be of any type as long as the temperature information for determining the relationship between the elapsed time and the output of the power supply 3 can be stored. For example, a known memory or the like may be used.

Further, in energization diffusion joining, it is very important to align the axes of the members to be joined in the pressurizing direction and to manage the load. Here, as a result of diligent research, the present inventor has found that the control state is reflected in the value of the contact resistance at the bonding interface. Therefore, by monitoring the contact resistance value, it is possible to determine whether or not the alignment of the axis lines and the management of the load can maintain the initial state. Further, depending on the degree of change in the contact resistance value, it is possible to clarify the maintenance time of the jig and tool for setting the member 1 to be joined in the energization diffusion joining device 10. Therefore, the current-carrying diffusion bonding apparatus 10 of the present invention may be provided with a voltage drop detecting means 53 that can supply a constant current to the members to be bonded 1 and can detect the voltage drop on the bonding surface S. The output control unit 5 can also control the output of the power supply 3 based on the voltage drop detected by the voltage drop detecting means 53. As a result, it is possible to further precisely control the temperature of the member 1 to be joined. Therefore, it is possible to perform joining with high joining strength on the joining surface S between the joining members and with little variation.

Next, other configurations of the electric diffusion welding device 10 will be described. The current diffusion bonding apparatus 10 includes a pressure unit 8 for applying pressure to the bonding surface S of the members 1 to be bonded. The structure of the pressurizing portion 8 may be any as long as pressure can be applied to the joint surface S of the member 1 to be joined. For example, the pressurizing member 81 to which the electrode 2 is fixed and the pressurizing member 81 are driven. And a ball screw mechanism 83 that transmits the driving force of the driving source 82 and moves the pressing member 81 up and down.

Here, the pressing member 81 is formed in a substantially columnar shape so as to have versatility, but may be formed in conformity with the shape of the member to be joined 1 or in conformity with the shape of the member to be joined 1. An intermediate member may be sandwiched between them. The material of the pressure member 81 may be any material as long as it has rigidity against pressure, and for example, a metal such as stainless steel, copper, molybdenum, or tungsten may be used. ‥

Although not shown, the pressing member 81 may have a cooling unit for cooling the bonded member 1. Any cooling means may be used as long as it can cool the members 1 to be joined. For example, a cooling fluid such as tap water may be circulated in the flow path. The flow path may be provided in the pressurizing member 81 itself, or the cooling block in which the flow path is formed may be arranged in close contact with the pressurizing member 81. ‥

As the drive source 82, for example, a servomotor with a speed reducer can be used. An encoder 74 is attached to the servo motor, and is arranged on a mount (not shown). ‥

The ball screw mechanism 83 is composed of a screw shaft extending in the vertical direction and having a thread groove formed on the outer peripheral surface, a nut having a thread groove formed on the inner peripheral surface, and a plurality of balls accommodated between the thread grooves. It is configured. The nut is fixed to the upper part of the pressing member 81 via an insulator made of Bakelite or the like and the pressure sensor 73. The screw shaft is connected to the rotating shaft of the servomotor via a speed reducer. When the servomotor is rotationally driven, the screw shaft rotates, and the nut, and by extension, the pressure member 81 moves up and down relatively with respect to the screw shaft. Further, when the driving of the servomotor is stopped, the position of the pressurizing member 81 is maintained. At this time, the pressurizing unit 8 regulates the displacement of the member 1 to be joined and applies pressure to the joining surface S. ‥

Further, the pressurizing unit 8 may include a pressure sensor 73 that detects the pressure of the joint surface S. The pressure sensor 73 is, for example, a uniaxial load cell that measures vertical pressure, but a multiaxial pressure sensor may be used. The pressure sensor 73 can indirectly detect the pressure applied to the joint surface S between the members 1 to be joined. ‥

Further, the pressurizing portion 8 may further include an elastic force urging means 84 for urging the joint surfaces S of the members to be joined 1 with an elastic force. For example, the elastic force urging means 84 is arranged between the base member 6 on which the pressure member 81 is arranged and the base 9 of the current-carrying diffusion joining device 10. The elastic force urging means 84 is composed of, for example, a spring 84a and a block body 84b for restricting the spring 84a to a preset length shorter than the free length between the spring 84a and the base member 6. The pressure exerted on the joined member 1 from the base member 6 pushed up by the elastic force urging means 84 varies depending on the material and shape of the joined member 1, but is, for example, 5 to 100N. This pressure can then be changed by replacing the spring 84a. With this configuration, even if the member 1 to be joined undergoes thermal expansion or contraction, a sudden change in pressure acting on the joint surface S can be alleviated. ‥

Although the above-described configuration has been described as the pressurizing unit 8, the pressurizing unit 8 may have any other configuration as long as it presses the members 1 to be welded with the joint surface S. For example, it is possible to simply use a member in which a weight is placed on the members 1 to be joined and the members 1 to be joined are pressed against each other. ‥

Further, the energization heating joining device 10 of the present invention may further include a pressure control unit 7 for controlling the pressure applied to the joining surface S. The pressure control unit 7 is composed of, for example, a CPU, a ROM, a RAM, an I / O, and the like, and the operation unit 71 and the display unit 72 are electrically connected to each other. The operation unit 71 is composed of a start switch, various operation switches such as a start switch, and an input panel including a touch panel. The information input from the operation unit 71 is transmitted to the pressure control unit 7. Further, the display unit 72 receives information from the pressure control unit 7 based on the input to the pressure control unit 7 or the calculation result of the pressure control unit 7, and displays the information. Here, the display unit 72 is composed of a digital display panel, a lamp, and the like. The pressure control unit 7 may be the same as the output control unit 5 described above. ‥

Further, detection signals are input to the pressure control unit 7 from the encoder 74, the pressure sensor 73, and the temperature sensor. The pressure control unit 7 is based on these detection signals, information input from the operation unit 71, and control information such as set pressure Ps, lower limit set pressure Ps1, set temperature Ts, and set holding time Hs stored in the storage unit. A control signal is output to the power supply 3 and the servomotor.

1: Joined member 2: Electrode 3: Power supply 4: Temperature information providing unit 5: Output control unit 6: Base member 7: Pressure control unit 8: Pressurizing unit 9: Base
10: Energization diffusion joining device
51: Operation unit
52: Display
53: Voltage drop detecting means
71: Operation unit
72: Display
73: Pressure sensor
74: Encoder
81: Pressurizing member
82: Drive source
83: Ball screw mechanism
84: Elastic force urging means
84a: Spring
84b: Block body S: Joining surface

Claims

It is an energization diffusion joining device that energizes and joins a plurality of members to be joined with the joint surface abutted.
A plurality of electrodes for conducting electricity to the plurality of members to be joined,
A power supply capable of continuously changing the output applied to the plurality of electrodes,
A temperature information providing unit that provides temperature information of the member to be joined or the electrode,
An output control unit that controls the output of the power supply with an upslope based on the temperature information from the temperature information providing unit.
An electric current diffusion bonding apparatus comprising:
The energization diffusion bonding device according to claim 1, further comprising a voltage drop detecting means capable of supplying a constant current to the bonded member and detecting a voltage drop on the bonding surface.
The current spreading/bonding device according to claim 2, wherein the output control unit controls the output of the power source based on the voltage drop detected by the voltage drop detection means.
The energization diffusion bonding device according to any one of claims 1 to 3, wherein the temperature information providing unit is a temperature sensor that detects temperature information of the member to be bonded or the electrode.
The current diffusion providing device according to any one of claims 1 to 3, wherein the temperature information providing unit is a temperature information storage unit that stores temperature information of the member to be joined or the electrode.
The current-carrying diffusion bonding apparatus according to any one of claims 1 to 5, further comprising a pressurizing unit for applying pressure to the bonding surface of the members to be bonded.