Solid-phase bonding device

Abstract

To control a bonding process in solid-phase bonding by feeding back measurement data of a contact portion in-process.SOLUTION: A solid-phase bonding device 1 comprises: a pair of pressurization shafts 11, 12; a heating device; a measuring device 13 that measures a temperature of a contact portion in a non-contact manner using infrared rays; and a control device 30. At least one of the pair of pressurization shafts 11, 12 includes a through-hole 11b in a pressing direction. The measuring device 13 measures the temperature of the contact portion by receiving infrared rays generated from the contact portion through the through-hole 11b. The control device 30 controls operations of the pair of pressurization shafts 11, 12 on the basis of measurement data measured by the measuring device 13.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a control method for a solid-state joining apparatus that joins, in a solid-state state, first and second workpieces that are electrically conductive and overlap each other in a thickness direction. [Background technology]

[0002] Japanese Patent No. 7242112 (Patent Document 1) discloses a solid-state spot joining apparatus equipped with a pressure mechanism including a pressing unit and a current-carrying mechanism including a pair of electrodes. The solid-state spot joining apparatus disclosed in Japanese Patent No. 7242112 (Patent Document 1) is configured to apply current to two metal plates using a pair of electrodes to heat each metal plate, and then press the two metal plates together using a pressing unit in a direction perpendicular to the metal plates. In a joining method (hereinafter also referred to as "solid-state joining") that joins metals in a solid state at a low temperature without melting them, such as that disclosed in Japanese Patent No. 7242112 (Patent Document 1), it is important to accurately detect whether the temperature at the contact point between the workpieces has reached a temperature suitable for joining in order to improve the joining quality. However, the solid-state joining disclosed in Japanese Patent No. 7242112 (Patent Document 1) does not disclose a technology for accurately measuring the temperature at the contact point between the workpieces.

[0003] In this regard, Japanese Patent Laid-Open Publication No. 2022-162847 (Patent Document 2) discloses a technique for measuring the temperature and load of workpieces being welded in real time during friction stir welding using frictional heat. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7242112 [Patent Document 2] Japanese Patent Publication No. 2022-162847 Summary of the Invention [Problem to be solved by the invention]

[0005] Japanese Patent Publication No. 2022-162847 (Patent Document 2) discloses a technology for measuring temperature using a thermocouple placed inside a rotary tool. However, in Japanese Patent Publication No. 2022-162847 (Patent Document 2), the thermocouple is not in contact with the workpiece, so it is not possible to directly measure the temperature at the contact point. Furthermore, in the structure shown in Japanese Patent Publication No. 7242112 (Patent Document 1), a large pressure is applied to the contact point by the pressure mechanism, so if a thermocouple or the like is placed at the contact point to directly measure the temperature, the thermocouple or the like will be damaged by the pressure during the joining process. Alternatively, the pressure and heat generated at the contact point will be combined, causing the thermocouple to be joined to the workpiece, making measurement impossible.

[0006] Even if temperature measurement can be performed using other methods, when solid-state welding dissimilar metals, the specific heat and inherent electrical resistance differ for each metal. Furthermore, when factors such as differences in the thickness and heat capacity of the metals being used as materials are combined, the temperature at the contact point will not be constant, making it difficult to contribute to improving and ensuring the quality of the joint. Thus, in the solid-state welding process, it is desirable to utilize the measured temperature to control the welding process. However, no control method has been proposed that controls the welding process by in-process feedback of measurement data from the contact point in a solid-state welding device.

[0007] An object of the present disclosure is to provide a technique for controlling a solid-state bonding process by in-process feedback of measurement data of a contact portion. [Means for solving the problem]

[0008] The solid-state joining apparatus of the present disclosure includes a pair of pressure shafts that press a first workpiece and a second workpiece, both of which have electrical conductivity, from both sides in the thickness direction, a heating device that heats the contact area where the first workpiece and the second workpiece contact each other when pressed by the pair of pressure shafts, a measuring device that measures the temperature of the contact area in a non-contact manner using infrared rays, and a control device. At least one of the pair of pressure shafts has a through hole formed in the pressing direction. The measuring device measures the temperature of the contact area by receiving infrared rays emitted from the contact area through the through hole. The control device controls the operation of the pair of pressure shafts based on the measurement data measured by the measuring device. [Effects of the Invention]

[0009] According to the present disclosure, at least one of the pair of pressure shafts has a through-hole formed in the pressing direction, and infrared rays generated from the contact area are received through the through-hole. Furthermore, a control device controls the operation of the pair of pressure shafts based on measurement data measured by the measurement device. This not only enables accurate measurement of the temperature of the contact area, but also contributes to improving and ensuring the quality of the joint by controlling the joining process through in-process feedback of the measurement data. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram schematically showing a solid-state joining apparatus according to a first embodiment. [Figure 2] FIG. 10 is a diagram for explaining a joining step. [Figure 3] FIG. 10 is a diagram showing changes in various items over time. [Figure 4] 4 is a flowchart showing the control content executed by the control device. [Figure 5] 10 is a flowchart showing the control content executed by a control device in a modified example. [Figure 6] FIG. 10 is a diagram schematically showing a solid-state joining apparatus according to a second embodiment. [Figure 7] FIG. 10 is a diagram schematically showing a solid-state joining apparatus according to a third embodiment. [Figure 8]4 is a flowchart showing the control content executed by the control device. [Figure 9] FIG. 10 is a diagram schematically showing a solid-state joining apparatus according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0012] [Embodiment 1] 1 is a diagram schematically illustrating a solid-state joining apparatus 1 according to embodiment 1. The solid-state joining apparatus 1 is an apparatus that forms softened regions at the interfaces of multiple workpieces W10, W20 by passing current through multiple workpieces W10, W20 that are stacked on top of each other, and then plastically deforms the softened regions to join the multiple workpieces W10, W20 together in a solid state without melting them.

[0013] The multiple workpieces W10, W20 include a first workpiece W10 and a second workpiece W20. Each workpiece W10, W20 is made of a metal such as iron or aluminum. Each workpiece W10, W20 is formed, for example, in a flat plate shape. Note that each workpiece W10, W20 may be made of a material other than metal, as long as it is electrically conductive and suitable for solid-state welding.

[0014] 1, the solid-state bonding apparatus 1 includes a solid-state bonding device 10, a control device 30, and a power supply device 60. The solid-state bonding device 10 includes a pair of pressure shafts 11 and 12, a pair of electrodes 21 and 22, a sensor 40, a measuring device 13, a housing 14, and an actuator 15. The "pressure shafts" may also be referred to as "pressure members" or "pressing members."

[0015] The pair of pressure applying shafts 11, 12 includes a first pressure applying shaft 11 and a second pressure applying shaft 12. The pair of pressure applying shafts 11, 12 can apply pressure to the first workpiece W10 and the second workpiece W20 from both sides in the thickness direction of the stacked plate-like workpieces. The first pressure applying shaft 11 is driven by an actuator 15 serving as a drive source. The second pressure applying shaft 12 may be provided with a sensor 40, a measuring device 13, a housing 14, and an actuator 15, similar to the first pressure applying shaft 11 side. Note that the second pressure applying shaft 12 may be fixed rather than being driven by a drive source (not shown). In this way, one of the pair of pressure applying shafts 11, 12 may be a fixed shaft.

[0016] The first pressure shaft 11 is capable of pressing the first workpiece W10 so as to plastically deform the first workpiece W10. Specifically, the first pressure shaft 11 is capable of pressing the first workpiece W10 so as to form a protrusion W11 on the first workpiece W10. The first pressure shaft 11 is made of, for example, tungsten carbide. In this embodiment, the first pressure shaft 11 is formed in a cylindrical shape. The first pressure shaft 11 has a pressing surface 11a that presses the first workpiece W10. The pressing surface 11a is an end surface of the first pressure shaft 11. The pressing surface 11a is formed in a circular shape. A first through hole 11b (hereinafter also referred to as through hole 11b) is formed inside the first pressure shaft 11 in the pressing direction.

[0017] The first through hole 11b is preferably formed near the center of the first pressure shaft 11 and has a circular cross section similar to the first pressure shaft 11. The diameter of the first through hole 11b may be large enough to allow infrared rays generated from the contact portion to pass through and to withstand pressure. The first through hole 11b may be located at a position offset from the center of the first pressure shaft 11, and the cross section may have a shape other than circular. As such, the through hole may have any shape as long as the temperature of the contact portion can be measured. The temperature of the contact portion does not refer to the temperature of the joining surface where the first workpiece and the second workpiece are in contact, but rather refers to the temperature directly above the joining surface radiated from the first through hole 11b on the pressing surface 11a of the first pressure shaft 11. In this disclosure, the temperature directly above the joining surface will be described as the temperature of the contact portion.

[0018] The second pressure applying shaft 12 has the same configuration as the first pressure applying shaft 11 except that no through hole is formed. The second pressure applying shaft 12 is disposed in such a position that the central axis of the second pressure applying shaft 12 is located on an extension of the central axis of the first pressure applying shaft 11 and the pressing surface 12a of the second pressure applying shaft 12 faces the pressing surface 11a of the first pressure applying shaft 11. The first pressure applying shaft 11 and the second pressure applying shaft 12 may have a shape other than a cylindrical shape.

[0019] The sensor 40 is provided, for example, on the actuator 15. In this embodiment, a load cell is used as the sensor 40. The location where the sensor 40 is installed is not limited to the actuator 15. The sensor 40 may also be provided on the first pressure shaft 11.

[0020] The pair of electrodes 21, 22 includes a first electrode 21 and a second electrode 22. The pair of electrodes 21, 22 can pass electricity through the first workpiece W10 and the second workpiece W20 while in contact with the first workpiece W10 and the second workpiece W20. When a voltage is applied to the pair of electrodes 21, 22 while the pair of electrodes 21, 22 are in contact with the first workpiece W10 and the second workpiece W20, power is supplied to the first electrode 21, the first workpiece W10, the second workpiece W20, and the second electrode 22.

[0021] The first electrode 21 can come into contact with a portion of the first workpiece W10 surrounding the portion that is pressed by the first pressing shaft 11. In this embodiment, the first electrode 21 is formed in a cylindrical shape that surrounds the first pressing shaft 11. A gap is provided between the inner peripheral surface of the first electrode 21 and the outer peripheral surface of the first pressing shaft 11. The first electrode 21 is made of, for example, copper. The first electrode 21 has a contact surface 21a that comes into contact with the first workpiece W10. The contact surface 21a is formed in an annular shape. However, the shape of the contact surface 21a is not limited to an annular shape.

[0022] The second electrode 22 has the same configuration as the first electrode 21. The second electrode 22 can come into contact with a portion of the second workpiece W20 surrounding a portion that is pressed by the second pressure shaft 12. The second electrode 22 is disposed in such a position that the central axis of the second electrode 22 is located on an extension of the central axis of the first electrode 21, and the contact surface 22a of the second electrode 22 faces the contact surface 21a of the first electrode 21.

[0023] The control device 30 includes an arithmetic unit 31, a memory 32, a storage device 33, and an input / output interface 34. These components are connected via a bus.

[0024] The arithmetic device 31 is a computing entity (computer) that executes predetermined processing. The arithmetic device 31 is configured with a processor such as a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), a TPU (Tensor Processing Unit), or a GPU (Graphics Processing Unit). A processor, which is an example of the arithmetic device 31, has the function of executing predetermined processing by executing a predetermined program. However, some or all of these functions may be implemented using dedicated hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). The term "processor" is not limited to processors in the narrow sense that execute processing using a stored program, such as a CPU, MPU, TPU, or GPU, but may also include hardwired circuits such as an ASIC or FPGA. Furthermore, the arithmetic device 31 is not limited to von Neumann computers such as a CPU or GPU, but may also be configured with a non-von Neumann computer such as a quantum computer or an optical computer. The arithmetic device 31 described above may also be interpreted as a processing circuitry that executes predetermined processing. The computing device 31 may be configured as a single chip or multiple chips. Furthermore, the processor and related processing circuits may be configured as multiple computers interconnected by wire or wirelessly via a local area network or a wireless network. The processor and related processing circuits may be configured as a cloud computer that performs remote calculations based on input data and outputs the calculation results to other devices in remote locations.

[0025] The memory 32 includes a storage area (for example, a working area) for storing program code or work memory when the arithmetic unit 31 executes various programs. Examples of the memory 32 include volatile memories such as DRAM and SRAM, and non-volatile memories such as ROM and flash memory.

[0026] The storage device 33 stores various programs and various data executed by the arithmetic device 31. For example, the storage device 33 stores a control program 330 executed by the arithmetic device 31 to control the pair of pressure shafts 11, 12 and the pair of electrodes 21, 22. The storage device 33 may be one or more non-transitory computer-readable media, or one or more computer-readable storage media. Examples of the storage device 33 include a hard disk drive (HDD) and a solid state drive (SSD).

[0027] Values ​​acquired by an acquisition unit such as a sensor 40 are input to the input / output interface .

[0028] The control device 30 controls the pair of pressure applying shafts 11, 12 and the pair of electrodes 21, 22. Specifically, the control device 30 controls the loads acting on the first workpiece W10 and the second workpiece W20 from each of the pair of pressure applying shafts 11, 12, the loads acting on the first workpiece W10 and the second workpiece W20 from each of the pair of electrodes 21, 22, the voltages applied to the pair of electrodes 21, 22, and the amounts of pressing of the pair of pressure applying shafts 11, 12 and the pair of electrodes 21, 22. The control device 30 controls the voltages applied to the pair of electrodes 21, 22, thereby controlling the current X passed through the pair of electrodes 21, 22.

[0029] The control device 30 applies a load F (see FIG. 1 ) from the pair of pressure shafts 11, 12 to the first workpiece W10 and the second workpiece W20 so that protrusions W11, W21 that come into contact with each other are formed on the first workpiece W10 and the second workpiece W20, respectively. The control device 30 also applies electricity to the first workpiece W10 and the second workpiece W20. Specifically, the control device 30 applies the load F from the pair of pressure shafts 11, 12 to the first workpiece W10 and the second workpiece W20, and applies electricity to the first workpiece W10 and the second workpiece W20 while bringing the contact surface 21 a of the first electrode 21 into contact with a portion of the first workpiece W10 surrounding a portion of the first workpiece W10 that is pressed by the first pressure shaft 11 and bringing the contact surface 22 a of the second electrode 22 into contact with a portion of the second workpiece W20 surrounding a portion of the second workpiece W20 that is pressed by the second pressure shaft 12. The control device 30 controls the current X shown by the broken line to flow between the pair of electrodes 21 and 22 via the protrusions W11 and W21.

[0030] Each of the protrusions W11, W21 is softened by the flow of current X. In this embodiment, the control device 30 causes the current X to flow to soften each of the protrusions W11, W21, and also applies a load F to the first workpiece W10 and the second workpiece W20. As a result, in this embodiment, the first workpiece W10 and the second workpiece W20 can be joined at the positions of each of the protrusions W11, W21.

[0031] The measuring device 13 is an infrared temperature sensor that measures the temperature of an object by receiving infrared rays emitted from the object. The measuring device 13 measures the temperature of the contact area in a non-contact manner by receiving, for example, infrared rays L1 generated from an area including the protrusions W11 and W21, which are contact areas where the first workpiece W10 and the second workpiece W20 come into contact, through the first through-hole 11b.

[0032] Next, a description will be given of how the joining process is performed at the protrusions W11 and W21 where the first workpiece W10 and the second workpiece W20 come into contact with each other. Fig. 2 is a diagram for explaining the joining process.

[0033] The control device 30 executes the joining process in the order of Fig. 2(A) to (D). As shown in Fig. 2(A), the pair of electrodes 21, 22 are fixed to the pair of pressure shafts 11, 12 by a spring 50. The biasing force of the spring 50 acts on each of the workpieces W10, W20 via the pair of electrodes 21, 22. The spring 50 is not shown in Fig. 2(B) and subsequent figures.

[0034] As shown in FIG. 2(A), the control device 30 moves the pair of pressure shafts 11, 12 toward the workpieces W10, W20. At this time, each workpiece W10, W20 is sandwiched between a pair of electrodes 21, 22. A contact load of, for example, 1 kN acts on each workpiece W10, W20 as a biasing force from a spring 50. The pair of electrodes 21, 22 is biased to a position that protrudes approximately 1 mm from the pair of pressure shafts 11, 12 toward the workpieces W10, W20. The pair of pressure shafts 11, 12 and the pair of electrodes 21, 22 are a mechanism that is entirely driven by a drive source (actuator 15).

[0035] Next, as shown in Fig. 2(B), the control device 30 moves the pair of pressure shafts 11, 12 toward the workpieces W10, W20 and applies a load to each of the workpieces W10, W20 to form the protrusions. The protrusions W11, W21 are formed on each of the workpieces W10, W20 by applying the load to each of the workpieces W10, W20 to form the protrusions.

[0036] Next, the control device 30 applies current to each of the protrusions W11, W21, as shown in Fig. 2(C). The control device 30 applies current to each of the protrusions W11, W21 formed at the contact portion of each of the workpieces W10, W20, to soften the contact portion of each of the protrusions W11, W21. Next, as shown in Fig. 2(D), the control device 30 applies current to each of the protrusions W11, W21 while pressing the pair of pressure shafts 11, 12 to the joining position, thereby joining the workpieces W10, W20 at the contact portion.

[0037] 2, a first through-hole 11b is formed inside the first pressure shaft 11 in the pressing direction. The first through-hole 11b is formed at the center position of the contact portion of each workpiece W10, W20 (the center position of each protrusion W11, W21). Therefore, infrared rays emitted from the contact portion reach the measuring device 13 through the first through-hole 11b. This allows the measuring device 13 to accurately measure the temperature of the contact portion of each workpiece W10, W20.

[0038] Next, we will explain how various items change over time. Figure 3 is a diagram showing how various items change over time. Figure 3 shows the change in stroke, change in load, change in current, infrared input / output, and temperature change at the contact points over time. Note that the stroke in Figure 3 indicates that the pressure shaft 11 and the pressure shaft 12 are operating with the same stroke amount, and the load in Figure 3 indicates that the pressure shaft 11 and the pressure shaft 12 are acting with the same load. The values ​​shown in Figure 3 are just examples and can be changed as appropriate depending on the plate thickness, material, etc. of each workpiece W10, W20.

[0039] As shown in FIG. 3, the control device 30 moves the tip of the solid-state welding apparatus 1 closer to each of the workpieces W10 and W20 from time T0 to time T1, and at time T1, the stroke, which is the distance between the tip of the solid-state welding apparatus 1 and each of the workpieces W10 and W20, is set to 0 [mm]. At time T1, the pair of electrodes 21 and 22 are in contact with each of the workpieces W10 and W20. From time T1 to time T2, the control device 30 applies a contact load from the pair of electrodes 21 and 22 to each of the workpieces W10 and W20. At this time, the current does not change, but the load increases by 1 [kN], the contact load when the pair of electrodes 21 and 22 contact each of the workpieces W10 and W20.

[0040] Next, the control device 30 forms the protrusions W11, W21 by pressing the pair of pressure shafts 11, 12 into each workpiece W10, W20 by 1.2 mm from time T2 to time T3. At this time, the stroke changes, and the protrusion forming load when pressing the pair of pressure shafts 11, 12 into each workpiece W10, W20 becomes 35 kN. The control device maintains the pressure due to the protrusion forming load from time T3 to time T5. Note that the pressure due to the protrusion forming load may change over time rather than being maintained.

[0041] Next, the control device 30 presses the pair of pressure shafts 11, 12 into the workpieces W10, W20 by 2.4 mm from time T5 to time T6, thereby joining the protrusions W11, W21 together. At this time, the stroke changes, and the joining load when the pair of pressure shafts 11, 12 are pressed into the workpieces W10, W20 becomes 40 kN.

[0042] The control device continues to pass a current of 11 kA through each of the protrusions W11 and W21 from time T5 to time T6. The temperature of the contact points where the protrusions W11 and W21 come into contact rises rapidly from time T5 to time T6. This allows the softened regions of the protrusions W11 and W21 to plastically deform while still being welded in a solid state. Once the welding is complete, the control device 30 returns the pair of pressure shafts 11 and 12 to their origin positions or to positions where they can be restarted from time T6 to time T7. This causes the load to become zero. The current is also turned off when the welding is complete.

[0043] Here, the control device 30 turns on the setting for receiving infrared rays at time T4, which is before time T5 when current is passed through each of the protrusions W11 and W21. This allows the measuring device 13 to receive infrared rays L1 before heating of the contact portion begins.

[0044] The timing for receiving infrared light may be the same as the timing when current flows at time T5, or may be turned on at any timing before heating. By receiving infrared light before heating, the temperature of the contact part in the heated state can be accurately measured.

[0045] The temperature of the contact point gradually decreases from the timing T6 when the current is turned off. The reception of infrared light is turned off when the load becomes 0 [kN].

[0046] Next, the processing executed by the control device 30 will be described in detail. Fig. 4 is a flowchart showing the control content executed by the control device 30. The processing of the flowchart in Fig. 4 is repeatedly called as a subroutine from the main routine in the control of the control device 30 and executed. First, in step S (hereinafter simply referred to as "S") 11, the control device 30 moves the pair of pressure shafts 11, 12 toward the first workpiece W10 and the second workpiece W20.

[0047] Next, the control device 30 determines whether the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 (S12). For example, the control device 30 acquires the detection value of the sensor 40 and determines that the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 based on an increase in the detection value. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have not contacted the first workpiece W10 and the second workpiece W20 (NO in S12), it returns to the process of S11. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 (YES in S12), it proceeds to the process of S13.

[0048] The control device 30 stores the contact position as a reference position in S13. Next, the control device 30 sets a protrusion formation position (S14). For example, the control device 30 controls the actuator 15 to set the pair of pressure shafts 11 and 12 to move 1.2 mm as the protrusion formation amount. Next, the control device 30 sets a joining push-in end position (joining position) (S15). For example, the control device 30 controls the actuator 15 to set the pair of pressure shafts 11 and 12 to move 2.4 mm as the joining push-in amount.

[0049] Next, the control device 30 pushes the pair of pressure shafts 11, 12 to the protrusion formation position set in S14 (S16). Next, the control device 30 controls the measurement device 13 to turn on infrared light reception so that the temperature of the contact portion can be detected, and then starts heating using the pair of electrodes 21, 22 (S17). Next, the control device 30 controls the pair of electrodes 21, 22 to apply current for bonding, while pushing the pair of pressure shafts 11, 12 to the bonding position set in S15 (S20). As shown in S17 and S20, the solid-state bonding apparatus 1 is set to receive infrared light just before each of the protrusions W11, W21 is heated by applying current. This allows the solid-state joining apparatus 1 to measure the timing close to when the temperature of the contact area rises, compared to settings that receive infrared rays at all times, receive infrared rays after heating, and receive infrared rays well before the protrusion is formed, and allows the temperature of the contact area between the workpieces to be measured accurately without being affected by external disturbances, etc.

[0050] Next, the control device 30 determines whether the pair of pressure shafts 11, 12 have reached the joining push-in end position (S21). The control device 30 may determine, for example, whether the pair of pressure shafts 11, 12 have moved from the contact position stored in S13 to the joining position set in S15 where the protrusions W11, W21 are joined to the first workpiece W10 and the second workpiece W20. Note that the control device 30 may also determine whether the pair of pressure shafts 11, 12 have moved to the protrusion formation position where the protrusions W11, W21 are formed after S16.

[0051] If the control device 30 determines that the pair of pressure shafts 11, 12 have not reached the joining push-in end position (NO in S21), the process returns to S20. If the control device 30 determines that the pair of pressure shafts 11, 12 have reached the joining push-in end position (YES in S21), the control device 30 stops the supply of electricity to the pair of electrodes 21, 22 and ends heating of the contact portion (S22).

[0052] Next, the control device 30 controls the actuator 15 to move the pair of pressure applying shafts 11, 12 toward the initial position (S23). Next, the control device 30 determines whether the pair of pressure applying shafts 11, 12 have reached the initial position (S24). If the control device 30 determines that the pair of pressure applying shafts 11, 12 have not reached the initial position (NO in S24), the control device 30 returns to the processing of S23. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have reached the initial position (YES in S24), the control device 30 controls the measuring device 13 to turn off infrared light reception (S25), and returns the processing from the subroutine to the main routine.

[0053] According to the solid-state joining apparatus 1 of the first embodiment, the infrared rays L1 can be received through the through-hole 11b without being affected by external disturbances, etc., and therefore the temperature of the contact portion between the workpieces can be accurately measured. The solid-state joining apparatus 1 of the first embodiment can accurately measure the temperature of the contact portion in a sufficiently heated state by receiving the infrared rays just before the projections W11, W21 are energized and heated.

[0054] Next, a modified example of the first embodiment will be described. Fig. 5 is a flowchart showing the control content executed by the control device in the modified example. In the processing of Fig. 5, the control device 30 performs the same processing as that of Fig. 4 except that the processing of S18 and S19 is added, the processing of S21 is changed to S21A, and the return position of the flowchart is different. In Fig. 5, the processing different from that of Fig. 4 will be mainly described.

[0055] After the process of S17, the control device 30 executes a temperature rise standby process to wait until the temperature of the contact portion reaches a predetermined temperature (S18). By executing the temperature rise standby process, the temperature can be raised to a level suitable for joining the protrusions W11, W21. Next, the control device 30 determines whether the temperature measured by the measuring device 13 is equal to or higher than the target temperature (S19).

[0056] If the control device 30 determines that the measured temperature is below the target value (NO in S19), it returns to the process of S18. This makes it possible to prevent poor welding caused by the temperature of the contact portion, which is the temperature directly above the joining surfaces of the first workpiece W10 and the second workpiece W20, falling below the target value. If the control device 30 determines that the measured temperature is equal to or higher than the target value (YES in S19), it proceeds to the process of S20. In S20, the control device 30 controls the pair of electrodes 21, 22 to apply current for joining, while pushing the pair of pressure shafts 11, 12 to the joining position set in S15 (S20). The process of S20 prevents a decrease in contact resistance and a decrease in the level of heat generation due to an increase in contact area caused by material deformation, and makes it possible to maintain the temperature by heat input and push the workpieces to the joining completion position.

[0057] Next, the control device 30 determines whether the pair of pressure shafts 11, 12 have reached the joining push-in end position (S21A). If the control device 30 determines that the pair of pressure shafts 11, 12 have not reached the joining push-in end position (NO in S21A), the process returns to S18. By returning to S18 if the pair of pressure shafts 11, 12 have not reached the joining push-in end position after the determination in S21A, heating is not terminated while maintaining the temperature by heat input during the joining push-in, which prevents poor joining. If the control device 30 determines that the pair of pressure shafts 11, 12 have reached the joining push-in end position (YES in S21A), the control device 30 stops the supply of electricity to the pair of electrodes 21, 22 and ends heating of the contact portion (S22).

[0058] In a modification of the first embodiment, when it is determined that the pair of pressure shafts 11, 12 have not reached the joining push-in end position (NO in S21A), the processes of S18 to S19 are executed again. As a result, heating is not ended until the temperature of the contact portion reaches or exceeds the target temperature. Therefore, even if the temperature of the contact portion drops during the process due to some influence, the temperature can be raised to a temperature appropriate for joining, and poor joining can be prevented. Note that if S21A is NO, the return position may be S20. As a result, although it is unclear whether the temperature of the contact portion has reached the target temperature, heating is not ended if the joining push-in end position has not been reached, and poor joining can be prevented.

[0059] In this way, the solid-state joining apparatus 1 in the modification of the first embodiment controls the operation of the pair of pressure shafts 11, 12 based on the measurement data obtained by the measuring device 13 receiving the infrared rays L1 through the through-hole 11b. This not only makes it possible to accurately measure the temperature of the contact area, but also contributes to improving and guaranteeing the joining quality by controlling the joining process by feeding back the measurement data in-process.

[0060] [Embodiment 2] Next, a solid-state bonding apparatus 10A according to embodiment 2 will be described. Fig. 6 is a diagram schematically showing the solid-state bonding apparatus 10A according to embodiment 2. The solid-state bonding apparatus 10A according to embodiment 2 differs from the solid-state bonding apparatus 10 according to embodiment 1 in that a through hole is formed not only in the first pressure shaft 11 but also in the second pressure shaft 12, and a measuring device 13 is arranged on the second pressure shaft 12 side.

[0061] The solid-state bonding apparatus 10A includes a pair of pressure shafts 11 and 12, a pair of electrodes 21 and 22, a pair of measuring devices 13, a pair of housings 14, and a pair of actuators 15. The sensor 40 shown in FIG. 1 is not shown. The solid-state bonding apparatus 10A includes a first pressure shaft 11 and a second pressure shaft 12 as the pair of pressure shafts 11 and 12. A first through-hole 11b is formed inside the first pressure shaft 11 in the pressing direction. A second through-hole 12b is formed inside the second pressure shaft 12 in the pressing direction.

[0062] The measuring device 13 on the first pressure applying shaft 11 side measures the temperature of the contact portion on the first workpiece W10 side (the temperature on the first workpiece W10 side directly above the joint surface where the first workpiece and the second workpiece come into contact) by, for example, receiving infrared light L1 through the first through-hole 11b. The measuring device 13 on the second pressure applying shaft 12 side measures the temperature of the contact portion on the second workpiece W20 side (the temperature on the second workpiece W20 side directly above the joint surface where the first workpiece and the second workpiece come into contact) by, for example, receiving infrared light L2 through the second through-hole 12b.

[0063] As shown in Fig. 6, the pair of measuring devices 13 can separately measure the temperature of the contact portion between the first workpiece W10 and the second workpiece W20 from the first pressure shaft 11 side and the second pressure shaft 12 side. For example, if the first workpiece W10 and the second workpiece W20 have different thicknesses, materials, etc., the temperature appropriate for joining may differ from that when the same materials are used. Even in such a case, by measuring the temperature of the contact portion from two directions, joining can be performed at an appropriate temperature.

[0064] [Embodiment 3] Next, a solid-state welding apparatus 1B according to a third embodiment will be described. FIG. 7 is a diagram schematically showing the solid-state welding apparatus 1B according to the third embodiment. The solid-state welding apparatus 1B according to the third embodiment is configured to heat the contact area where the first workpiece W10 and the second workpiece W20 come into contact with each other using a laser beam, rather than by energizing a pair of electrodes 21, 22. Therefore, the solid-state welding apparatus 1B according to the third embodiment does not have a power supply unit 60 and has a different configuration from the solid-state welding apparatus 1 according to the first embodiment. The solid-state welding apparatus 1B will be described mainly with respect to the differences from the solid-state welding apparatus 1.

[0065] The solid-state welding apparatus 10B includes a pair of pressure shafts 11 and 12, a laser oscillator 51, a measuring device 13, a pair of housings 14, and a pair of actuators 15. The solid-state welding apparatus 10B includes a first pressure shaft 11 and a second pressure shaft 12 as the pair of pressure shafts 11 and 12. A first through-hole 11b is formed inside the first pressure shaft 11 in the pressing direction. A second through-hole 12b is formed inside the second pressure shaft 12 in the pressing direction. Sensors 40 are disposed on the actuator on the first pressure shaft 11 side and the actuator 15 on the second pressure shaft 12 side.

[0066] The laser oscillator 51 on the first pressure applying shaft 11 irradiates laser light L3 through the first through-hole 11b to heat the contact area where the first workpiece W10 and the second workpiece W20 come into contact (the portion on the first workpiece W10 side directly above the joint surface where the first workpiece and the second workpiece come into contact). The measuring device 13 on the second pressure applying shaft 12 receives infrared light L2 through the second through-hole 12b to measure the temperature of the contact area where the first workpiece W10 and the second workpiece W20 come into contact (the temperature on the second workpiece W20 side directly above the joint surface where the first workpiece and the second workpiece come into contact).

[0067] The solid state bonding apparatus 1B of FIG. 7 does not have the power supply unit 60 and the pair of electrodes 21, 22, and therefore can accurately measure the temperature of the contact portion while reducing the size of the entire apparatus.

[0068] Next, a specific description will be given of the processing executed by the control device 30 of the third embodiment. Fig. 8 is a flowchart showing the control content executed by the control device 30. First, in step S31, the control device 30 moves the pair of pressure axes 11, 12 toward the first workpiece W10 and the second workpiece W20.

[0069] Next, the control device 30 determines whether the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 (S32). For example, the control device 30 acquires the detection value of the sensor 40 and determines that the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 based on an increase in the detection value. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have not contacted the first workpiece W10 and the second workpiece W20 (NO in S32), it returns to the processing of S31. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have contacted the first workpiece W10 and the second workpiece W20 (YES in S32), it proceeds to the processing of S33.

[0070] In S33, the control device 30 stores the contact position as a reference position. Next, the control device 30 sets a joining push-in end position (joining position) (S34). Here, the process of FIG. 8 does not include a protrusion formation step, unlike the process of FIG. 4. The solid-state joining apparatus 1B heats the contact portion using a laser oscillator 51, rather than by passing current through the pair of electrodes 21, 22. This eliminates the need to form a protrusion to restrict the current path.

[0071] Next, the control device 30 controls the measuring device 13 to turn on infrared light reception so that the temperature of the contact portion can be detected (S35). Next, the control device 30 controls the laser oscillator 51 to irradiate the contact portion with laser light L3 to heat the contact portion (S36). Next, the control device 30 executes a temperature rise standby process to wait until the temperature of the contact portion reaches a predetermined target temperature (S37). By executing the temperature rise standby process, the temperature can be raised to a temperature suitable for joining the first workpiece W10 and the second workpiece W20.

[0072] Next, the control device 30 determines whether the temperature measured by the measuring device 13 is equal to or higher than the target temperature (S38). If the control device 30 determines that the measured temperature is lower than the target value (NO in S38), the process returns to S37. If the control device 30 determines that the measured temperature is equal to or higher than the target value (YES in S38), the process proceeds to S39. In S39, the control device 30 presses the pair of pressure shafts 11, 12 to the joining position set in S34 while irradiating the laser light L3.

[0073] Next, the control device 30 determines whether the pair of pressure shafts 11, 12 have reached the joining push-in end position (S40). If the control device 30 determines that the pair of pressure shafts 11, 12 have not reached the joining push-in end position (NO in S40), the process returns to S37. If the control device 30 determines that the pair of pressure shafts 11, 12 have reached the joining push-in end position (YES in S40), the control device 30 controls the laser oscillator 51 to turn off the laser light irradiation signal, thereby ending heating of the contact portion (S41).

[0074] If it is determined that the pair of pressure shafts 11, 12 have not reached the joining push-in end position (NO in S40), the processes of S37 to S38 are executed again. By returning to the process of S37 when the joining push-in end position has not been reached, heating is not terminated in a state where the temperature is maintained by heat input during the joining push-in, which makes it possible to prevent poor joining. Note that if S40 is NO, the return position may be S39. In this way, although it is unclear whether the temperature of the contact portion has reached the target temperature, heating is not terminated if the joining push-in end position has not been reached, making it possible to prevent poor joining.

[0075] Next, the control device 30 controls the actuator 15 to move the pair of pressure applying shafts 11, 12 toward the initial position (S42). Next, the control device 30 determines whether the pair of pressure applying shafts 11, 12 have reached the initial position (S43). If the control device 30 determines that the pair of pressure applying shafts 11, 12 have not reached the initial position (NO in S43), the control device 30 returns to the processing of S42. If the control device 30 determines that the pair of pressure applying shafts 11, 12 have reached the initial position (YES in S43), the control device 30 controls the measuring device 13 to turn off infrared light reception (S44), and the processing returns from the subroutine to the main routine.

[0076] [Embodiment 4] Next, a solid-state welding apparatus 10C according to embodiment 4 will be described. Fig. 9 is a diagram schematically showing the solid-state welding apparatus 10C according to embodiment 4. The solid-state welding apparatus 10C according to embodiment 4 differs from the solid-state welding apparatus 10 according to embodiment 1 in that a measuring device 13 and a laser oscillator 51 are arranged in a housing 14 on the first pressurizing shaft 11 side.

[0077] A first through-hole 11b is formed inside the first pressure shaft 11 in the pressing direction. The laser oscillator 51 on the first pressure shaft 11 side heats the contact area where the first workpiece W10 and the second workpiece W20 come into contact (the portion on the first workpiece W10 side directly above the joint surface where the first workpiece and the second workpiece come into contact) by irradiating laser light L3 through the first through-hole 11b. The measuring device 13 on the first pressure shaft 11 side receives infrared light L2 through the first through-hole 11b to measure the temperature of the contact area where the first workpiece W10 and the second workpiece W20 come into contact (the temperature on the first workpiece W10 side directly above the joint surface where the first workpiece and the second workpiece come into contact).

[0078] 9 can perform heating and measurement of the contact portion by using the first through-hole 11b on the side of the first pressing shaft 11. This allows wiring and the like to be collected on the side of the first pressing shaft 11, making it possible to accurately measure the temperature of the contact portion while facilitating wiring management compared to when separate devices are provided on the side of the first pressing shaft 11 and the side of the second pressing shaft 12.

[0079] In each of the above embodiments, the pair of pressure shafts 11, 12 may both be movable, or one of them may be fixed. When one of the pressure shafts is fixed, the measuring device 13 may be arranged on the fixed shaft side or on the moving shaft side.

[0080] In each of the above embodiments, the heating device may be either a pair of electrodes 21, 22 or a laser oscillator 51, or any other heating method may be used. The measuring device 13 may be disposed on at least one of the pair of pressure shafts 11, 12, and may be combined with any heating device.

[0081] <Summary> (1-1) The solid-state joining apparatus 1 of the present disclosure includes a pair of pressure shafts 11, 12 that press a first workpiece W10 and a second workpiece W20, each having electrical conductivity, from both sides in the thickness direction, a heating device that heats the contact area where the first workpiece W10 and the second workpiece W20, which are pressed by the pair of pressure shafts 11, 12, come into contact, and a measuring device 13 that uses infrared rays to measure the temperature of the contact area in a non-contact manner. A through hole 11b is formed in at least one of the pair of pressure shafts 11, 12 in the pressing direction. The measuring device 13 measures the temperature of the contact area by receiving infrared rays L1 generated from the contact area through the through hole 11b.

[0082] According to the solid-state joining apparatus 1 of the present disclosure, the temperature of the contact portion between the workpieces can be accurately measured by receiving infrared rays L1 generated from the contact portion through the through-hole 11b.

[0083] (1-2) In the solid-state joining apparatus 1 of (1-1), the heating device includes a pair of electrodes 21, 22 respectively arranged around the pair of pressure shafts 11, 12. The pair of electrodes 21, 22 heats the contact area by passing current through them while the first workpiece W10 and the second workpiece W20 are in contact with each other.

[0084] According to the solid-state bonding apparatus 1 of the present disclosure, the contact portion can be heated using the pair of electrodes 21, 22, and the temperature of the heated contact portion can be accurately measured.

[0085] (1-3) In the solid-state joining apparatus 1 of (1-1), the heating device includes a laser oscillator 51 that irradiates a laser beam. The laser oscillator 51 heats the contact portion by irradiating the contact portion with a laser beam while the first workpiece W10 and the second workpiece W20 are in contact with each other.

[0086] According to the solid-state bonding apparatus 1 of the present disclosure, the contact portion can be heated using the laser oscillator 51, and the temperature of the heated contact portion can be accurately measured.

[0087] (1-4) In the solid-state joining apparatus 1 of any one of (1-1) to (1-3), the pair of pressure applying shafts 11, 12 includes a first pressure applying shaft 11 that applies pressure to the first workpiece W10 and a second pressure applying shaft 12 that applies pressure to the second workpiece W20. A first through hole 11b is formed inside the first pressure applying shaft 11 in the pressing direction. A second through hole 12b is formed inside the second pressure applying shaft 12 in the pressing direction. The measuring device 13 measures the temperature of the contact portion on the first workpiece W10 side by receiving infrared rays through the first through hole 11b, and measures the temperature of the contact portion on the second workpiece W20 side by receiving infrared rays through the second through hole 12b.

[0088] According to the solid-state joining apparatus 1 of the present disclosure, the measuring device 13 can separately measure the temperature of the contact portion from the first pressure shaft 11 side and the temperature of the contact portion from the second pressure shaft 12 side at the contact portion where the first workpiece W10 and the second workpiece W20 come into contact.

[0089] (1-5) In the solid-state joining apparatus 1 (1B) of (1-1) or (1-3), the pair of pressure shafts 11, 12 includes a first pressure shaft 11 that presses the first workpiece W10 and a second pressure shaft 12 that presses the second workpiece W20. A first through hole 11b is formed inside the first pressure shaft 11 in the pressing direction. A second through hole 12b is formed inside the second pressure shaft 12 in the pressing direction. A laser oscillator 51 irradiates laser light through the first through hole 11b, and a measuring device 13 receives infrared light through the second through hole 12b.

[0090] According to the solid-state bonding apparatus 1 (1B) of the present disclosure, the temperature of the contact portion can be accurately measured while the entire apparatus is made smaller.

[0091] (1-6) In the solid-state joining apparatus 1 of (1-1) or (1-3), the pair of pressure shafts 11, 12 includes a first pressure shaft 11 that presses the first workpiece W10 and a second pressure shaft 12 that presses the second workpiece W20. A first through hole 11b is formed inside the first pressure shaft 11 in the pressing direction. A laser oscillator 51 irradiates laser light through the first through hole 11b. A measuring device 13 receives infrared light through the first through hole 11b.

[0092] According to the solid-state joining apparatus 1 of the present disclosure, it is possible to easily route the wiring and to accurately measure the temperature of the contact portion.

[0093] (2-1) The solid-state joining apparatus 1 of the present disclosure includes a pair of pressure shafts 11, 12 that press a first workpiece W10 and a second workpiece W20, each having electrical conductivity, from both sides in the thickness direction, a heating device that heats the contact area where the first workpiece W10 and the second workpiece W20, which are pressed by the pair of pressure shafts 11, 12, come into contact, a measuring device 13 that measures the temperature of the contact area using infrared rays in a non-contact manner, and a control device 30. A through hole 11b is formed in at least one of the pair of pressure shafts 11, 12 in the pressing direction. The measuring device 13 measures the temperature of the contact area by receiving infrared rays emitted from the contact area through the through hole 11b. The control device 30 controls the operation of the pair of pressure shafts 11, 12 based on the measurement data measured by the measuring device 13.

[0094] According to the solid-state joining apparatus 1 of the present disclosure, infrared rays are received through the through-hole 11b, so the temperature of the contact portion can be measured accurately. Furthermore, the control device 30 controls the operation of the pair of pressure shafts 11, 12 based on the measurement data measured by the measuring device 13. Therefore, by controlling the joining process by feeding back the measurement data in-process, it is possible to contribute to improving and guaranteeing the joining quality.

[0095] (2-2) In the solid-state bonding apparatus 1 of (2-1), the control device 30 starts measurement by the measuring device 13 before the heating of the contact portion by the heating device starts.

[0096] According to the solid-state joining apparatus 1 of the present disclosure, it is possible to accurately measure the temperature of the contact portion while the workpieces are heated.

[0097] (2-3) In the solid-state joining apparatus 1 of (2-1) or (2-2), when the temperature of the contact area becomes equal to or higher than the target temperature for joining the first workpiece W10 and the second workpiece W20, the control device 30 controls the pair of pressure shafts 11, 12 to push the first workpiece W10 and the second workpiece W20 to the joining position.

[0098] According to the solid-state bonding apparatus 1 of the present disclosure, bonding can be performed at a temperature of the contact portion equal to or higher than a target temperature suitable for bonding.

[0099] (2-4) In any of the solid-state joining apparatuses 1 (2-1) to (2-3), if the first workpiece W10 and the second workpiece W20 have been pushed in but have not yet reached the joining position, the control device 30 again determines whether the temperature of the contact area is equal to or higher than the target temperature.

[0100] According to the solid-state bonding apparatus 1 of the present disclosure, heating does not end until the temperature of the contact area reaches or exceeds the target temperature. Therefore, even if the temperature of the contact area drops during the process due to some influence, the temperature can be raised to a temperature appropriate for bonding, thereby preventing poor bonding.

[0101] (2-5) In the solid-state joining apparatus 1 of any one of (2-1) to (2-4), the heating device includes a pair of electrodes 21, 22 respectively arranged around the pair of pressure shafts 11, 12. The pair of electrodes 21, 22 heats the contact portion by passing current through them while the first workpiece W10 and the second workpiece W20 are in contact with each other.

[0102] According to the solid-state bonding apparatus 1 of the present disclosure, the contact portion can be heated using the pair of electrodes 21, 22, and the temperature of the heated contact portion can be accurately measured.

[0103] (2-6) In the solid-state joining apparatus 1 of any one of (2-1) to (2-4), the heating device includes a laser oscillator 51 that irradiates a laser beam. The laser oscillator 51 heats the contact portion by irradiating the contact portion with a laser beam while the first workpiece W10 and the second workpiece W20 are in contact with each other.

[0104] According to the solid-state bonding apparatus 1 of the present disclosure, the contact portion can be heated using the laser oscillator 51, and the temperature of the heated contact portion can be accurately measured.

[0105] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0106] 1,1B solid-state bonding apparatus, 10,10A,10B,10C solid-state bonding equipment, 11,12 pressure shaft, 11a,12a pressing surface, 11b first through hole, 12b second through hole, 13 measuring device, 14 housing, 15 actuator, 21,22 electrodes, 21a,22a contact surface, 30 control device, 31 arithmetic unit, 32 memory, 33 storage device, 34 input / output interface, 40 sensor, 50 spring, 51 laser oscillator, 60 power supply unit, 330 control program, F load, X current, W10,W20 workpiece, W11,W21 protrusion.

Claims

1. a pair of pressure shafts that press the first and second conductive workpieces from both sides in a thickness direction; a heating device that heats a contact portion where the first workpiece and the second workpiece that are pressed by the pair of pressing shafts come into contact with each other; a measuring device that measures the temperature of the contact portion in a non-contact manner using infrared rays; a control device; a through hole is formed in at least one of the pair of pressure shafts in the pressing direction; the measuring device measures the temperature of the contact portion by receiving infrared rays generated from the contact portion through the through hole; The control device controls the operation of the pair of pressure shafts based on the measurement data measured by the measuring device.

2. 2. The solid-state joining apparatus according to claim 1, wherein the control device starts the measurement by the measuring device before the heating of the contact portion by the heating device starts.

3. 3. The solid-state joining apparatus according to claim 1, wherein the control device controls the pair of pressure shafts to push the first workpiece and the second workpiece to a joining position when the temperature of the contact portion becomes equal to or higher than a target temperature for joining the first workpiece and the second workpiece.

4. 4. The solid-state joining apparatus according to claim 3, wherein the control device determines again whether or not the temperature of the contact portion is equal to or higher than the target temperature when the first workpiece and the second workpiece have not yet reached the joining position after being pushed in.

5. the heating device includes a pair of electrodes respectively disposed around the pair of pressure shafts, 2. The solid-state joining apparatus according to claim 1, wherein the pair of electrodes are energized while the first workpiece and the second workpiece are in contact with each other, thereby heating the contact portion.

6. the heating device includes a laser oscillator that irradiates laser light, 2. The solid-state joining apparatus according to claim 1, wherein the laser oscillator heats the contact portion by irradiating the contact portion with the laser light while the first workpiece and the second workpiece are in contact with each other.

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