JP4890633B2 - Current diffusion bonding apparatus and method - Google Patents

Description

  The present invention relates to an electric diffusion bonding apparatus and method.

  Conventionally, current diffusion bonding is known in which a metal member is heated in a solid phase temperature range and bonded by an atomic diffusion phenomenon. The electric current diffusion bonding is suitable for the bonding of the same material or different materials made of a hardly weldable metal material.

  In energization diffusion bonding, a member to be bonded is sandwiched between electrodes, and a pressure current is applied to the bonding surface via the electrode by a pressurizing mechanism to flow a pulse current between the electrodes to heat the member to be bonded. Then, in the solid phase temperature range below the melting temperature of the member to be joined, the joining is performed by the adhesion of the joining surface due to softening and deformation of the material and the solid phase diffusion phenomenon.

  By the way, if even a slight gap occurs between the joining surfaces, joining failure occurs, so the member to be joined is heated while applying a large pressure from the pressurizing mechanism. However, when the base material temperature exceeds the softening start temperature, deformation such as distortion, bending, and compression occurs in the bonded member due to the applied pressure.

  Therefore, Patent Document 1 includes a pressure sensor that detects the pressure applied to the member to be joined, and feedback-controls the pressing force with a value determined by the material and dimensions of the member to be joined based on the detection value of the pressure sensor. A pulse energization bonding apparatus is disclosed. Specifically, in order to prevent the pressure applied to the member to be bonded due to the thermal expansion of the member to be bonded, the pressing force is fed back so that the detected value of the pressure sensor becomes constant after the start of energization. (Refer to paragraph 0017 of Patent Document 1 in particular). The pressing force is controlled by controlling an electric motor that drives the ball screw device of the pressing device.

  Further, Patent Document 2 includes a temperature detection unit that detects the temperature of the bonded portion, and a member displacement monitoring unit that monitors the displacement of the bonded member, and in a state where the temporal change in the temperature of the bonded portion is positive, An energization joining apparatus is disclosed that reduces the pressure applied to a member to be joined when it is detected that the displacement of the member to be joined is negative. The pressurization is performed using a commonly used mechanism such as a hydraulic type, a pneumatic type, or a mechanical type (see paragraph 0021 of Patent Document 2).

JP 2007-253240 A JP 2007-175740 A

  However, in the pulse energization joining apparatus disclosed in Patent Document 1, since the pressing force is controlled by the electric motor, a time lag occurs until the pressing force is changed in response to the detected value of the pressure sensor. There was a problem that the member to be joined was deformed. Moreover, in the energization joining apparatus disclosed in Patent Document 2, the member displacement monitoring unit detects that the displacement of the member to be joined has become negative, that is, compressive deformation, and then reduces the applied pressure. Therefore, there has been a problem that compression deformation is unavoidable in the members to be joined.

  In particular, when the member to be joined is a thin member such as a thin pipe material, it is deformed instantaneously, and the degree of deformation becomes significant. In recent years, environmental awareness such as the rise of electric vehicles has increased, and there has been an increasing demand for joining thin-walled members with high precision, but no measures have been realized to suppress deformation within several tens of micrometers.

  In view of the above, an object of the present invention is to provide an energization diffusion bonding apparatus and method capable of bonding a member to be bonded made of a thin pipe material or the like with high accuracy.

Energizing diffusion bonding apparatus of the present invention is a current diffusion bonding apparatus for bonding by energizing the plurality of bonded members, which is in contact with the bonding surface, and sandwich the plurality of bonded members, the plurality of the expansion and bonding member electrically conductible plurality of electrodes, a power supply unit for supplying current to said plurality of electrodes for clamped on the direction of the plurality of bonded members sandwiched plurality of electrodes A first pressurizing unit that regulates displacement in a direction to apply pressure to the joining surface, and a direction of expansion with respect to a direction in which the plurality of members to be joined sandwiched between the plurality of electrodes are sandwiched A second pressurizing unit that applies a pressure based on an elastic force of an elastic member that is elastically deformed in accordance with displacement to the joint surface via the plurality of electrodes, and either the first or second pressurizing unit. A pressure selection unit that selects whether to apply pressure to the joint surface. And features.

  According to the energization diffusion bonding apparatus of the present invention, the first and second pressure units and the pressure selection unit that selects whether to apply pressure to the bonding surface by any of these pressure units are provided. Since the first pressurizing unit regulates the displacement of the member to be joined and applies the pressure, it applies a large pressure to the joining surface. Therefore, a large pressure can be applied to the bonding surface when the bonding surface needs to be brought into close contact with the first pressurizing unit, for example, at the start of energization.

  On the other hand, the second pressurizing unit applies a pressure based on the elastic force of the elastic member elastically deforming according to the displacement of the bonded member to the bonded surface, so that the bonded member is heated by energization from the power supply unit to the electrode. Even if it thermally expands, the pressure applied to the joint surface does not change greatly. Therefore, when it is not preferable to apply an excessive pressure to the bonding surface, such as after the temperature of the member to be bonded approaches the softening start temperature, a relatively small pressure is applied to the bonding surface by the second pressure unit. It becomes possible to do.

  The elastic member is elastically deformed according to the thermal expansion of the member to be joined, but the change in elastic force due to the deformation is minute. Therefore, the pressure applied to the joining surface by the second pressurizing unit is substantially constant regardless of the thermal expansion of the member to be joined. Therefore, unlike the devices disclosed in Patent Documents 1 and 2, an excessive pressure is applied. There is no risk of being granted. Therefore, even if the member to be joined is made of a thin pipe material or the like, it is possible to join with high accuracy.

  Then, in consideration of the characteristics of the pressure applied by the first and second pressurizing units, the pressurizing selection unit selects the pressurizing unit to apply the pressure to the state of the member to be joined. It is possible to apply a suitable pressure to the bonding surface.

The energization diffusion bonding apparatus of the present invention includes a temperature sensor that detects a temperature of the member to be bonded, and the pressurization selection unit is based on the temperature detected by the temperature sensor, and the first or second pressurization unit to grant pressure on the bonding surface by any of.

Pressure selection unit, when the temperature sensor has exceeded the temperature preset temperature, for example, and a predetermined temperature by a temperature lower than the softening start temperature of the workpieces detected, the second pressure from the first pressure portion It becomes possible to apply pressure to the joint surface by switching to the pressure part. Therefore, it can join favorably, without a to-be-joined member changing.

  The pressurization selection unit is a condition other than temperature, such as a switchover from the first pressurization unit to the second pressurization unit when a preset time has elapsed since the start of electrode energization, or a temperature The first pressure unit may be switched to the second pressure unit based on conditions including other conditions. Furthermore, the pressurization selection unit may include switching from the second pressurization unit to the first pressurization unit when the displacement amount of the bonded member exceeds a preset amount. Good.

  In the energization diffusion bonding apparatus of the present invention, the first pressurizing unit applies a pressure to the bonding surface by regulating a position of a member to which the electrode is fixed, and the second pressurizing unit includes: It is preferable to apply an elastic force of the elastic member to the member to apply pressure to the joint surface.

  In this case, the first and second pressure units can be simply made compact and configured.

An energization diffusion bonding method of the present invention is an energization diffusion bonding method of energizing and bonding a plurality of members to be bonded that are in contact with bonding surfaces, and is expanded in a direction in which the plurality of members to be bonded are sandwiched. regulating the direction of displacement of, by applying pressure to the joining surface, the workpieces sandwiched between the plurality of bonded members and the electrically conductive manner a plurality of electrodes, a current to the plurality of electrodes And when the temperature in the vicinity of the joining surfaces of the plurality of members to be joined exceeds a preset temperature, the displacement restriction of the plurality of members to be joined is released, and the plurality of members sandwiched between the plurality of electrodes A pressure based on an elastic force of an elastic member that is elastically deformed according to a displacement in a direction in which the member to be bonded is sandwiched is applied to the bonding surface via the plurality of electrodes. To do.

  According to the energization diffusion bonding method of the present invention, pressure is applied to the bonding surfaces by regulating the displacement of the members to be bonded until the temperature of the members to be bonded exceeds a preset temperature. For this reason, it is possible to apply a large pressure to the bonding surface to bring the bonding surface into close contact.

  And when the temperature of a to-be-joined member exceeds preset temperature, the pressure based on the elastic force of the elastic member which elastically deforms according to the displacement of a to-be-joined member is provided to a joining surface. The elastic member is elastically deformed according to the thermal expansion of the member to be joined, but the change in elastic force due to the deformation is minute, and the pressure applied to the joining surface is substantially constant regardless of the thermal expansion of the member to be joined. Therefore, unlike the methods disclosed in Patent Documents 1 and 2, there is no possibility that an excessive pressure is applied. Therefore, even if the member to be joined is made of a thin pipe material or the like, it is possible to join with high accuracy.

1 is a front view of an electric diffusion bonding apparatus according to a first embodiment of the present invention. The enlarged view which shows the press unit periphery of FIG. FIG. 3 is a block diagram of energization diffusion bonding. The flowchart which shows the electricity-diffusion joining method which concerns on 1st Embodiment of this invention. The graph which shows the time change of the temperature and the pressure of a junction part in an electricity diffusion bonding method. The side view of the electricity diffusion bonding apparatus which concerns on 2nd Embodiment of this invention. The enlarged front view which shows the electrode unit periphery of the electricity supply diffusion bonding apparatus which concerns on 3rd Embodiment of this invention. The flowchart which shows the electricity-diffusion joining method which concerns on 3rd Embodiment of this invention.

  Hereinafter, the electric current diffusion bonding apparatus 1 which is 1st Embodiment of this invention is demonstrated.

  With reference to FIG. 1 to FIG. 3, the current diffusion bonding apparatus 1 joins the contact portions in a state where a plurality, in this case, two members to be joined M, M are in contact. The energization diffusion bonding apparatus 1 includes an electrode unit 10, a power supply unit 20, a pressure unit 30, a vacuum unit 40, and a control unit 50. These units 10 to 50 are mounted on the gantry 60.

  The material and shape of the member to be joined M are not particularly limited as long as energization is possible. As the material of the contacted member M, for example, steel materials such as stainless steel, simple non-ferrous metals such as copper, aluminum and zinc, metal materials such as various alloys including aluminum, nickel, chromium, titanium and copper, Examples include non-metallic materials such as ceramics, semiconductors, and single crystal materials having high-temperature conductivity. The members to be joined M and M may be made of the same material or different materials.

  Examples of the shape of the member to be bonded M include a pipe shape, a bulk shape, a thick plate shape, and a thin plate shape, and any processing such as grooving or drilling 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. The joining surface S is preferably a mirror surface, but may be a rough surface. Note that three or more members to be joined may be arranged in series to join the members to be joined. Further, a positioning pin or the like may be used for positioning the member to be joined.

  The electrode unit 10 includes a pair of upper and lower electrodes 11 and 12. Here, the upper electrode 11 includes a cylindrical upper energizing electrode 11a made of copper, molybdenum, tungsten or the like, and a resistor 11b fixed to the lower portion of the upper energizing electrode 11a, and the upper portion of the upper energizing electrode 11a is insulated. It is fixed to the top plate 61 of the gantry 60 via the body 13.

  Here, the lower electrode 12 includes a cylindrical lower energizing electrode 12a made of copper, molybdenum, tungsten, or the like, and a resistor 12b fixed to the upper portion of the lower energizing electrode 12a. The lower portion of the lower energizing electrode 12a is insulated. It is fixed to a movable table 31 described later via the body 14.

  The resistors 11b and 12b are made of a material that generates heat when energized, and are made of, for example, a carbon composite material, silicon carbide, or stainless steel.

  The upper and lower electrodes 11 and 12 are arranged so that the axes thereof are on the same line, and the members to be joined M and M are sandwiched therebetween. The upper and lower energization electrodes 11a and 12a are connected to the power supply unit 20 via cables (not shown), respectively, and are configured to be energized. By energizing the upper and lower energizing electrodes 11a and 12a with the members to be joined M and M sandwiched between the resistors 11b and 12b, the joining surface S is directly heated and the whole materials to be joined M and M are uniformly heated. Thus, continuous joining in the same process becomes possible.

  The upper and lower energization electrodes 11a and 12a are configured to be cooled by circulating a cooling fluid such as pure water or tap water by a cooling mechanism (not shown).

  Here, the power supply unit 20 is an inverter control pulse power supply. This power supply unit 20 includes a rectifier circuit, an inverter having a diode and a thyristor, and a pulse characteristic adjusting element such as a pulse waveform, a pulse width, a pulse interval, a current, and a voltage to be generated can be changed by the control unit 50. It is configured. As the power supply unit 20, a mass-produced product of a commercially available inverter power supply can be used.

  The pressure unit 30 includes a movable table 31 to which the lower energization electrode 12a is fixed, a pressure plate 32 for transmitting pressure to the movable table 31, a drive source 33 for driving the pressure plate 32, and a drive. A ball screw mechanism 34 that transmits the driving force of the source 33 and moves the pressure plate 32 up and down, and a pressure adjustment body 35 that adjusts the pressure transmitted from the pressure plate 32 to the movable table 31 are configured. .

  The movable table 31 is provided with bearings (bushings) 31a at the four corners thereof, and the four guide rods 64 that vertically connect the upper plate 62 and the lower plate 63 of the gantry 60 via these bearings 31a. It is configured to be slidable in the vertical direction. The movable table 31 corresponds to a member of the present invention.

  The pressure plate 32 is provided with bearings (bushes) 32a at the four corners thereof, and is configured to be slidable in the vertical direction with respect to the four guide rods 64 via the bearings 32a. The pressure plate 32 is located below the movable table 31 via the pressure adjustment body 35.

  Here, the drive source 33 is a servo motor with a speed reducer. The servo motor 33 is provided with an encoder 33a, and is fixed to the lower portion of the gantry 60 by known fixing means (not shown).

  The ball screw mechanism 34 includes a screw shaft 34a extending in the vertical direction and having a thread groove formed on the outer peripheral surface, a nut 34b fixed to the lower portion of the pressure plate 32 and having a thread groove formed on the inner peripheral surface, It is comprised from the some ball | bowl 34c accommodated between the thread grooves. The screw shaft 34a is connected to the rotation shaft of the servo motor 33 via a speed reducer. When the servo motor 33 is driven to rotate, the screw shaft 34a rotates, and the nut 34b and consequently the pressure plate 32 move up and down relatively with respect to the screw shaft 34a.

  The pressure adjusting body 35 includes a base 35 a having a fitting recess that fits into a convex portion formed at the upper center of the pressure plate 32, and a screw portion screwed into a screw hole formed in the base 35 a. The spring rod 35b is fixed to the base 35a, and the shaft of the spring rod 35b is slidable vertically by a predetermined distance between the upper surface of the base 35a and the lower surface of the upper flange of the spring rod 35b. A spring block 35c inserted therethrough, and a spring 35d that is interposed between the upper surface of the base 35a and the lower surface of the upper flange portion of the spring block 35c, and that extrapolates the lower body of the spring block 35c. It is configured.

  The spring 35d corresponds to the elastic member of the present invention and is a coil spring here, but may be another type of spring. The axis lines of the upper and lower electrodes 11 and 12, the ball screw mechanism 34, and the pressure adjusting body 35 are configured to be located on the same line. The base 35a, the spring rod 35b, and the spring block 35c are made of a hard material such as metal.

  An interposition block 36 made of a hard material such as metal is in contact with the upper surface of the spring block 35 c, and the interposition block 36 is fixed to the lower surface of the movable table 31 via a pressure sensor 37. The pressure sensor 37 is, for example, a uniaxial load cell that measures the pressure in the vertical direction, but a multiaxial pressure sensor may be used. The pressure sensor 37 can indirectly detect the pressure applied to the joint surface S.

  Note that the pressure adjusting body 35 is replaced according to the members to be joined M and M, and although not shown, it is preferable to provide a sensor for detecting the presence or absence of the pressure adjusting body 35.

  The rotational driving force of the servo motor 33 is converted into a vertical driving force by the ball screw mechanism 34, and the pressure plate 32 is raised. At this time, in the state where the pressure plate 32 is raised until the total length of the spring 35d is compressed to the total length L of the lower body of the spring block 35c, the movable table 31 includes a base 35a, a spring block 35c, and an interposition block 36. The pressure applied to the pressure plate 32 is transmitted without decreasing.

  Then, when the drive of the servo motor 33 is stopped, the position of the pressure plate 32 and consequently the movable table 31 is maintained. At this time, the pressurizing unit 30 regulates the displacement of the members to be joined M and M to apply pressure to the joining surface S, and functions as the first pressurizing unit of the present invention. In addition, although the pressure which the pressurization unit 30 which functions as a 1st pressurization part gives differs according to the to-be-joined member M, it is 5000N thru | or 10000N, for example.

  On the other hand, when the total length of the spring 35d is longer than the total length L of the lower main body of the spring block 35c, the movable table 31 has the same urging force (elastic force) as the spring 35d via the spring block 35c and the interposition block 36. Pressure is applied. At this time, the pressure unit 30 applies a pressure based on the urging force of the spring 35d to the joint surface S, and functions as the second pressure unit of the present invention. In addition, although the pressure which the pressurization unit 30 which functions as a 2nd pressurization part provides differs according to the to-be-joined member M, it is several dozen N thru | or several hundred N, for example.

  A position sensor 38 that detects the position of the movable table 31 is installed on the column 65 of the gantry 60. The position sensor 38 is, for example, a magnetic linear scale (linear encoder), and detects the vertical position of the movable table 31.

  In addition, a stopper 66 is fixed to each guide rod 64 between the movable table 31 and the pressure plate 32 in order to restrict the lowering of the movable table 31 beyond a predetermined position. Here, the lowering of the movable table 31 is restricted by the bearing 31 a coming into contact with the stopper 66. By restricting the lowering of the movable table 31 that is lowered when the pressure plate 32 is lowered, the pressure adjusting body 35 can be replaced.

  The evacuation unit 40 makes at least a portion including the joining surface S of the members to be joined M and M into a vacuum atmosphere. Thereby, generation | occurrence | production of an oxide film on the joint surface S is suppressed, and joining becomes easy and strong. Here, the vacuum unit 40 includes a chamber 41 that surrounds the entire members M and M, a vacuum device 42 that evacuates the chamber 41, and a vacuum breaker 43 that breaks the vacuum state in the chamber 41. It is configured.

  The vacuum device 42 is, for example, a vacuum pump that discharges the gas in the chamber 41 via a supply / exhaust pipe (not shown). The vacuum breaker 43 is, for example, a gas supply pump that supplies gas into the chamber 41 via a supply / exhaust pipe. The vacuum breaker 43 may be a valve or the like provided in the supply / exhaust pipe in order to introduce outside air into the chamber 41.

  A Pirani type vacuum sensor 44 for detecting the degree of vacuum (pressure) in the chamber 41 is installed. Further, a temperature sensor 45 for detecting the temperature in the vicinity of the joining surface S of the members to be joined M and M arranged in the chamber 41 is installed outside the side window of the chamber 41. Here, the temperature sensor 45 is a non-contact type sensor such as an infrared radiation thermometer. The temperature sensor 45 may be replaced with a contact type sensor such as a thermocouple for measuring the temperature by contacting the vicinity of the joining surface S of the member to be joined. A non-contact type sensor and a contact type sensor may be used in combination. Also good.

  Moreover, although not shown in figure, the door for taking in / out the to-be-joined members M and M is provided in the front side of the chamber 41. As shown in FIG. Instead of the evacuation unit 40, a chamber 41 may be used to make an atmosphere of an inert gas such as nitrogen or argon.

  The control unit 50 includes a CPU, a ROM, a RAM, an I / O, and the like, and an operation unit 51 and a display unit 52 are electrically connected. Here, the operation unit 51 includes various operation switches such as a start switch and a start switch, an input panel including a touch panel, and the like. Information input from the operation unit 51 is transmitted to the control unit 50.

  In addition, detection signals are input to the control unit 50 from the encoder 33a, the pressure sensor 37, the position sensor 38, the vacuum sensor 44, and the temperature sensor 45. Based on these detection signals, information input from the operation unit 51, and control information such as the set pressure P1, the first set temperature T1, and the second set temperature T2 stored in the storage unit, the control unit 50 Then, control signals are output to the servo motor 33, the vacuum device 42 and the vacuum breaker 43. The control unit 50 corresponds to a pressure selection unit of the present invention.

  When the detected temperature exceeds the target temperature, the temperature sensor 45 directly outputs an off signal for turning off the power to the power supply unit 20. Further, the temperature sensor 45 directly outputs an ON signal for turning on the power supply to the power supply unit 20 when the detected temperature becomes lower than the target temperature. Thus, since the signal is directly output from the temperature sensor 45 to the power supply unit 20 without using the control unit 50, the temperature in the vicinity of the joining surface S of the members to be joined M and M can be quickly returned to the target temperature. Become. Therefore, the temperature in the vicinity of the joining surface S of the members to be joined M and M is always maintained at the target temperature.

  In addition, a display unit 52 is electrically connected to the control unit 50. Here, the display unit 52 includes a digital display panel, a lamp, and the like. The display unit 52 receives information from the control unit 50 based on an input to the control unit 50 or a calculation result in the control unit 50, and displays the information.

  Next, processing when the current diffusion bonding method according to the first embodiment of the present invention is performed using the above-described current diffusion bonding apparatus 1 will be described with reference to FIGS. In addition, the following processes of S4 to S12 are executed by the control unit 50.

  First, an operator installs the pressure adjusting body 35 suitable for the members to be joined M and M (S1). And an operator installs the to-be-joined members M and M between the upper and lower electrodes 11 and 12 (S2). At this time, clamping of the members to be joined M, M may be assisted by a positioning pin or the like. Then, the operator closes the door (not shown) of the chamber 41.

  When the start switch of the operation unit 51 is turned on by the operator (S3: YES), the servo motor 33 is driven to compress the total length of the spring 35d to the total length L of the lower body of the spring block 35c, and the pressure sensor 37 is Until the pressure P to be detected exceeds a predetermined set pressure P1 (S5: YES), the pressurizing plate 32 and eventually the movable table 31 are raised (S4). As a result, a predetermined large pressure is applied to the members to be joined M, M via the movable table 31, and the joining surface S is brought into close contact. The servo motor 33 is feedback-controlled with reference to the detection signal from the encoder 33a.

  Next, the vacuuming device 42 is started. When the degree of vacuum in the chamber 41 detected by the vacuum sensor 44 reaches a predetermined value, the vacuuming device 42 is stopped. Thereby, the inside of the chamber 41 is evacuated (S6).

  While maintaining a state in which a predetermined pressure is applied to the members to be joined M, M, the power supply unit 50 is started to energize the upper and lower electrodes 11, 12 (S7). Thereby, the to-be-joined members M and M are heated, temperature rises, and it expands thermally.

  After that, when the temperature T detected by the temperature sensor 45 exceeds the first set temperature T1 lower than the softening start temperature Ts of the members to be joined M and M (S8: YES), the servo motor 33 is driven and the spring The pressure plate 32 is lowered by a predetermined minute distance so that the total length of the spring 35d extends until it exceeds the total length L of the lower body of the spring block 35c (S9). However, the state where the upper surface of the spring block 35c is in contact with the interposition block 36 is maintained.

  As a result, the urging force of the spring 35d is applied to the movable table 31, and the joint surface S is maintained in close contact by the urging force. However, since the biasing force of the spring 35d is small, even if the temperature of the members to be joined M and M further approaches the softening start temperature Ts, the base material of the members to be joined M and M is deformed, bent, or compressed. Absent.

  When the temperature T detected by the temperature sensor 45 exceeds the second set temperature T2 that is a predetermined temperature higher than the first set temperature T1 (S10: YES), the temperature T detected by the temperature sensor 45 becomes the second set temperature T2. The maintained state is continued for a predetermined time (S11). This is performed by the temperature sensor 45 directly outputting an off signal or an on signal to the power supply unit 20. During this time, the members to be joined M and M contract due to thermal expansion, and the pressure P gradually decreases. And the joining surface S of the to-be-joined members M and M is joined firmly.

  Note that the detection value from the position sensor 38 is monitored, and it is detected whether or not the movable table 31 has moved beyond a preset range in the vertical direction from the start of this state. When it is detected that the movable table 31 has moved beyond the set range, the occurrence of abnormality is displayed on the display unit 52.

  Further, the detection value from the pressure sensor 37 is monitored to detect whether or not the pressure P detected by the pressure sensor 37 exceeds an upper limit and a lower limit, respectively. When the pressure detected by the pressure sensor 37 exceeds the upper limit, the servo motor 33 is driven to lower the pressure plate 32. On the other hand, when the lower limit is exceeded, the servo motor 33 is driven to raise the pressure plate 32. When the pressure sensor 37 detects the pressure P exceeding the set range, the abnormality occurrence is displayed on the display unit 52.

  However, these processes are emergency evacuation processes when an abnormality occurs, and the amount of movement of the movable table 31 detected by the position sensor 38 and the pressure P detected by the pressure sensor 37 are within a set range during normal processing. It will fit.

  Thereafter, the power supply unit 20 is stopped, the vacuum breaker 43 is started to release the vacuum state in the chamber 41, and the servo motor 33 is driven to lower the pressure plate 32 and eventually the movable table 31 (S12). Then, the operator takes out the joining member from the chamber 41 (S13).

  As described above, until the temperature T detected by the temperature sensor 45 exceeds the first set temperature T1 (S8: NO), the pressurizing unit 30 regulates the displacement of the joined members M and M by the pressurizing plate 32. Since a large pressure is applied to the joining surface S, the joining surface S can be brought into close contact.

  Then, after the temperature T detected by the temperature sensor 45 exceeds the first set temperature T1 (S8: YES), the pressure based on the elastic force of the spring 35d that is elastically deformed according to the displacement of the members to be joined M, M is applied. Since it gives to joining surface S, even if to-be-joined member M and M thermally expand, the pressure given to joining surface S does not change a lot.

  The spring 35d is elastically deformed in accordance with the thermal expansion of the members to be joined M and M, but the change in elastic force due to the deformation is minute. Therefore, the pressure applied to the joining surface S is substantially constant regardless of the thermal expansion of the members to be joined M, M, and unlike the devices disclosed in Patent Documents 1 and 2, there is a possibility that an excessive pressure is applied. Absent. Therefore, even if the members to be joined M, M are made of a thin pipe material or the like, it is possible to join with high accuracy.

  Conventionally, a thin member made of a thin-walled pipe material or the like has been joined by an electron beam or brazing, which requires a high degree of skill and is expensive. Using the electric diffusion bonding apparatus 1, it becomes possible to automatically join a thin member made of a thin pipe material or the like at a low cost.

  Hereinafter, the current diffusion bonding apparatus 101 according to the second embodiment of the present invention will be described.

  With reference to FIG. 6, the current diffusion bonding apparatus 101 connects a large number of members to be bonded M in series to form a long member. Since the electric diffusion bonding apparatus 101 is similar to the electric diffusion bonding apparatus 1 described above, the same or corresponding members are denoted by the same reference numerals, and only different portions will be described.

  The energization diffusion bonding apparatus 101 includes an electrode unit 110 that sandwiches a member to be bonded M and energizes the member. Here, the member to be joined M is a cylindrical member.

  The electrode unit 110 includes three electrodes 111, 112, and 113. Here, the vertically opposed electrodes 111 and 112 are, respectively, cylindrical current-carrying electrodes 111a and 112a made of copper, molybdenum, tungsten, and the like, and resistors 111b and 111b fixed to opposite sides of the current-carrying electrodes 111a and 112a. 112b.

  An upper end portion of the upper energizing electrode 111a is fixed to a piston of an air cylinder 115 slidable in the vertical direction via an insulator 114. The lower end portion of the lower energizing electrode 112a is fixed to the cradle 117 via an insulator 116.

  Here, the electrode 113 includes a cylindrical energizing electrode 113a made of copper, molybdenum, tungsten, or the like, and a resistor 113b fixed to one end of the energizing electrode 113a, and the other end of the energizing electrode 113a. Is fixed to a movable plate 131 to be described later via an insulator 118.

  The electrodes 111 and 112 are arranged so that the axes thereof are on the same line, and when the electrode 111 is pushed down by the air cylinder 115, the member M to be bonded is sandwiched between the electrodes 111 and 112. The electrode 113 is arranged such that its axis is on the same line as the axis of the member to be joined M, and the surface opposite to the joint surface S of the member to be joined M is in contact.

  As a result, the member M is sandwiched between the electrodes 111, 112, and 113 with the axis thereof horizontally. A receiving jig 119 for supporting the member to be joined M is also provided.

  The energization electrodes 111a, 112a, and 113a are connected to the power supply unit 20 via cables (not shown), respectively, and are configured to be energized. By energizing the energizing electrodes 111a, 112a, and 113a with the member to be bonded M sandwiched between the resistors 111b, 112b, and 113b, the vicinity of the bonding surface S can be heated and the entire material to be bonded M can be uniformly heated. This enables continuous joining in the same process.

  The current diffusion bonding apparatus 101 includes a cooling unit 120 that cools the bonded members M after bonding. The cooling unit 120 includes cooling bodies 121 and 122 that are in contact with the upper and lower sides of the member to be joined M and configured to be cooled by circulating a cooling fluid such as pure water or tap water by a cooling mechanism (not shown).

  The cooling bodies 121 and 122 are arranged on the same line, and when the upper cooling body 121 is pushed down by the air cylinder 123, the member to be joined M is placed between the lower cooling body 122 supported by the cradle 124. It is sandwiched up and down. Thus, the cooling unit 120 also has a function of supporting the joined member M after joining.

  The energization diffusion bonding apparatus 101 includes a pressure unit 130 that applies a pressure P to the bonding surface S of the member M to be bonded. The pressure unit 130 includes a movable plate 131 to which the energization electrode 113a is fixed, a pressure plate 132 for transmitting pressure to the movable plate 131, a drive source 133 for driving the pressure plate 132, and a drive source. The ball screw mechanism 134 that transmits the driving force 133 and moves the pressure plate 132 in the left-right direction in FIG. 6 and the pressure adjustment body 135 that adjusts the pressure transmitted from the pressure plate 132 to the movable plate 131. It is configured.

  The movable plate 131 is configured to be slidable in the left-right direction with respect to the linear motion guide 136 fixed to the base 102. The movable plate 131 corresponds to a member of the present invention.

  The pressure plate 132 is configured to be slidable in the left-right direction with respect to the linear motion guide 136. The pressure plate 132 is located on the opposite side of the movable plate 131 from the electrode unit 110 with the pressure adjustment body 135 interposed therebetween.

  Here, the drive source 133 is a servo motor with a speed reducer. The servo motor 133 is provided with an encoder, and is fixed to the base 102 by known fixing means (not shown).

  Since the ball screw mechanism 134 is the same as the above-described ball screw mechanism 34 except that the pressure plate 132 is changed to move in the left-right direction, the description thereof is omitted. The pressure adjustment body 135 is also the same as the pressure adjustment body 35 described above, and a description thereof will be omitted. Although not shown, a position sensor for detecting the position of the movable table 131 is provided.

  The current diffusion bonding apparatus 101 includes a vacuum unit 140 that places at least a portion including the bonding surface S of the member to be bonded M in a vacuum atmosphere. The vacuum unit 140 includes a chamber 141 that surrounds the entire two members to be bonded M having the bonding surfaces S to be bonded. Although not shown, the vacuuming unit 140 also includes a vacuuming device 42, a vacuum breaker 43, a vacuum sensor 44, and a temperature sensor 45, similar to the vacuuming unit 40 described above.

  Here, the chamber 141 is formed with a hole in close contact with the electrodes 111 and 113 and the cooling body 121 so that the electrodes can slide. The chamber 141 contains the electrode 112, the cooling body 122, the cradles 117 and 124, and the receiving jig 119.

  Further, the vacuum unit 140 includes a support portion 142 for supporting the joined member M after joining. The support part 142 includes a cylindrical member 142a made of a hard material, and a donut-shaped elastic member 142b located between the inner peripheral surface of the cylindrical member 142a and the outer peripheral surface of the member M to be joined.

  The elastic member 142b can inject air into the inside by an air pump (not shown), thereby bringing the elastic member 142b into close contact with the cylindrical member 142a and the member to be joined M, thereby preventing vacuum leakage. It becomes possible. Further, the support part 142 is also provided as appropriate in a part away from the chamber 141.

  In addition, when the inside of the chamber 141 is evacuated, if a vacuum leaks from the end of the joined member M to be joined, a cylindrical elastic member may be disposed at the end, although not shown. By injecting air into the elastic member with an air pump (not shown), the elastic member and the inner peripheral surface of the member to be joined M can be brought into close contact with each other.

  Furthermore, although not shown, the current diffusion bonding apparatus 101 includes a control unit 50, an operation unit 51, and a display unit 52 as in the case of the current diffusion bonding apparatus 1 described above.

  Since the process at the time of carrying out the current diffusion bonding method according to the embodiment of the present invention using the current diffusion bonding apparatus 101 described above is the same as the method described with reference to FIG. 3, the description thereof is omitted. .

  Thereby, the current diffusion bonding apparatus 101 has the same advantages as the current diffusion bonding apparatus 1 described above. Furthermore, by using the electric current diffusion bonding apparatus 101, it becomes easy to connect a large number of members to be bonded M in series and easily form a long member continuously.

  Hereinafter, the electric diffusion bonding apparatus 201 which is 3rd Embodiment of this invention is demonstrated.

  Referring to FIG. 7, the current diffusion bonding apparatus 201 is capable of simultaneously bonding a large number of sets of members to be bonded M and M in parallel. Since the electric diffusion bonding apparatus 201 is similar to the electric diffusion bonding apparatus 1 described above, the lower part is not shown, the same or corresponding members are denoted by the same reference numerals, and only different portions will be described.

  The current diffusion bonding apparatus 201 includes an electrode unit 210 having a plurality of pairs of upper and lower electrodes 11 and 12. The members to be joined M and M are sandwiched between the electrodes 11 and 12 and are energized.

  The upper part of the upper energizing electrode 11a constituting the upper electrode 11 is fixed to the pressure adjusting body 231 via the insulator 13 respectively. Lower portions of the lower energizing electrodes 12a constituting the lower electrode 12 are fixed to the pressure adjusting body 232 via the insulators 14, respectively.

  The upper and lower electrodes 11 and 12 are arranged so that the axes thereof are on the same line, and the members to be joined M and M are sandwiched therebetween. By energizing the upper and lower energizing electrodes 11a and 12a with the members to be joined M and M sandwiched between the resistors 11b and 12b, the joining surface S is directly heated and the whole materials to be joined M and M are uniformly heated. Thus, continuous joining in the same process becomes possible.

  The current diffusion bonding apparatus 201 includes a pressure unit 230 that applies pressure P to the bonding surface S of the members to be bonded M and M. The pressure unit 230 includes a plurality of pressure adjusting bodies 231, a plurality of pressure adjusting bodies 232, a first pressure plate 233 to which the upper portion of each pressure adjusting body 231 is fixed, and each pressure adjusting body 232. The second pressure plate 234 to which the lower portion of the plate is fixed, the servo motor 33 (see FIG. 1) for driving the second pressure plate 234, the driving force of the servo motor 33 is transmitted, and the second pressure plate The ball screw mechanism 34 moves the 234 up and down.

  The pressure adjusting bodies 231 and 232 are both configured in the same manner as the pressure adjusting body 35 described above. However, the elastic coefficient of the spring 231 a of the pressure adjusting body 231 is smaller than the elastic coefficient of the spring 232 a of the pressure adjusting body 232. By using the pressure adjusting body 231, it is possible to pressurize the bonding members M and M evenly.

  The first pressure plate 233 is fixed to the gantry 60 and is configured as a top plate of the gantry 60 here.

  The second pressure plate 234 is provided with bearings (bushings) 234a at the four corners thereof, and is configured to be slidable in the vertical direction with respect to the four guide rods 64 via the bearings 234a.

  The servo motor 33 and the ball screw mechanism 34 are the same as the drive source motor 33 and the ball screw mechanism 34 described above, and thus the description thereof is omitted. When the servo motor 33 is driven to rotate, the screw shaft 34a rotates, and the second pressure plate 234 moves up and down relatively with respect to the screw shaft 34a.

  The energization diffusion bonding apparatus 201 includes a evacuation unit 240 that puts at least a portion including the bonding surfaces S of all the members to be bonded M into a vacuum atmosphere. The vacuum unit 240 includes a chamber 241 that surrounds a plurality of sets of members to be joined M and M each having a joining surface S to be joined. Although not shown, the vacuuming unit 240 includes a vacuuming device 42, a vacuum breaker 43, a vacuum sensor 44, and a temperature sensor 45 as in the vacuuming unit 40 described above.

  The chamber 241 includes all the upper and lower electrode pairs 11 and 12, the pressure adjusting bodies 231 and 232, the first pressure plate 233 and the second pressure plate 234.

  Further, although not shown, the current diffusion bonding apparatus 201 includes a control unit 50, an operation unit 51, and a display unit 52 as in the case of the current diffusion bonding apparatus 1 described above.

  With reference to FIG. 8, a description will be given of processing when the current diffusion bonding method according to the embodiment of the present invention is performed using the current diffusion bonding apparatus 201 described above.

  First, the worker installs pressure adjusting bodies 231 and 232 suitable for the members to be joined M and M (S1). And an operator installs the to-be-joined members M and M between the upper and lower electrodes 11 and 12 (S2). At this time, clamping of the members to be joined M, M may be assisted by a positioning pin or the like. Then, the operator closes the door (not shown) of the chamber 241.

  When the start switch of the operation unit 51 is turned on by the operator (S3: YES), the servo motor 33 is driven, and the total length of the springs 231a and 232a of the pressure adjusting bodies 231 and 232 is set to the lower body of the spring block. The second pressure plate 234 is raised until the entire length is compressed and the pressure P detected by the pressure sensor 37 exceeds a predetermined set pressure P1 (S5: YES) (S4). Thereby, a predetermined large pressure is applied to the members to be joined M and M via the first pressure plate 231 and the second pressure plate 234, and the joining surface S is brought into close contact.

  Next, the vacuuming device 42 is started. When the degree of vacuum in the chamber 41 detected by the vacuum sensor 44 becomes a predetermined value or less, the vacuuming device 42 is stopped. Thereby, the inside of the chamber 41 is evacuated (S6).

  While maintaining a state in which a predetermined pressure is applied to the members to be joined M, M, the power supply unit 50 is started to energize the upper and lower electrodes 11, 12 (S7). Thereby, the to-be-joined members M and M are heated, temperature rises, and it expands thermally.

  Thereafter, when the temperature T detected by the temperature sensor 45 exceeds the first set temperature T1 lower than the softening start temperature Ts of the members to be joined M and M (S8: YES), the servo motor 33 is driven to The second pressure plate 234 is lowered by a predetermined minute distance so that the spring total length of the spring 231a of the pressure adjusting body 231 extends beyond the total length of the lower body of the spring block (S9). However, the state where the upper surface of the spring block is in contact with the intervening block is maintained. Thereby, the state where the joint surface S is in close contact by the urging force of the spring 231a is maintained. However, since the urging force of the spring 231a is small, even if the temperature of the members to be joined M, M approaches the softening start temperature Ts, the base material of the members to be joined M, M is deformed, bent, compressed, etc. Absent.

  And the temperature T in the vicinity of the joining surface S of the to-be-joined members M and M detected by the temperature sensor 45 is increased by increasing the current to be passed through the upper and lower energizing electrodes 11a and 12a sandwiching the to-be-joined members M and M. When the second set temperature T2 higher than the first set temperature T1 by a predetermined temperature is exceeded (S10: YES), the temperature T detected by the temperature sensor 45 is maintained at the second set temperature T2 for a predetermined time (S11). ). This is performed by the temperature sensor 45 directly outputting an off signal or an on signal to the power supply unit 20. During this time, the members to be joined M and M contract due to thermal expansion, and the pressure P gradually decreases. And the joining surface S of the to-be-joined members M and M is joined firmly.

  And this is repeated and the joining surface S of all the to-be-joined members M and M is joined sequentially. When the position sensor 38 or the pressure sensor 37 detects an abnormal value, the occurrence of abnormality is displayed on the display unit 52.

  Thereafter, the power supply unit 20 is stopped, the vacuum breaker 43 is started, the vacuum state in the chamber 241 is released, the servo motor 33 is driven, and the second pressure plate 234 is lowered (S12). Then, the operator takes out the joining member from the chamber 241 (S13).

  Thereby, the electric current diffusion bonding apparatus 201 has the same advantages as the electric current diffusion bonding apparatus 1 described above. Furthermore, by using the energization diffusion bonding apparatus 201, it becomes easy to join a large number of members M to be joined simultaneously in parallel.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, the number of electrodes with respect to the member to be joined M and the installation site are not limited.

  Further, in the energization diffusion bonding apparatus 201 for simultaneously bonding a plurality of sets of members to be bonded M, M, a case in which the pressure adjusting bodies 231 and 232 are provided for each set of members to be bonded M, M has been described. . However, it is not limited to this, You may provide the pressurization adjustment bodies 231 and 232 which are common to several sets of to-be-joined members M and M.

  Further, the case where the lower electrode 12 is operated in the energization diffusion bonding apparatus 1 has been described. However, the present invention is not limited to this, and the upper electrode 11 may be operated, or the upper and lower electrodes 11 and 12 may be operated together.

  Further, in the energization diffusion bonding apparatus 1, the case where the pressure unit 30 applies pressure to the bonding surface S through the upper and lower electrodes 11 and 12 has been described. However, the present invention is not limited to this, and a member corresponding to the movable table 31 may be directly brought into contact with the members to be joined M and M without the upper and lower electrodes 11 and 12 to apply pressure to the joining surface S.

  Further, the case where the pressure adjusting body 35 is positioned between the movable table 31 and the pressure plate 32 in the energization diffusion bonding apparatus 1 has been described. However, the present invention is not limited to this, and for example, the pressure adjusting body may be positioned between the upper electrode 11 and the top plate 61 and the movable table 31 and the pressure plate 32 may be integrated.

  In the energization diffusion bonding apparatus 1, 101, 201, the case where the movable tables 31, 131 and the second pressure plate 234 are reciprocated by the ball screw mechanisms 34, 134 has been described. However, the mechanism for reciprocating the movable tables 31 and 131 and the second pressure plate 234 is not limited to this, and a known mechanism may be used. For example, a linear movement guide mechanism may be used.

  Further, the case where the springs 35d, 231a, and 232a correspond to the elastic members of the present invention has been described. However, the elastic member is not limited to this, and may be a material made of an elastic material such as rubber, a fluid cushion using a hydraulic cylinder, an air cylinder, or the like. It is not limited at all including a formula etc. However, the use of a mechanical spring has the advantage of excellent reproducibility during repeated use.

  DESCRIPTION OF SYMBOLS 1,101,201 ... Current-diffusion joining apparatus 11 ... Upper electrode (electrode), 12 ... Lower electrode (electrode), 20 ... Power supply unit (power supply part) 30, 130, 230 ... Pressurization unit (1st addition unit) Pressure part, second pressure part), 31 ... movable table (member), 32, 132 ... pressure plate, 33, 133 ... drive source, servo motor, 34, 134 ... ball screw mechanism, 35, 135, 231 , 232 ... Pressure adjusting body, 35d, 231a, 232a ... Spring (elastic member), 45 ... Temperature sensor, 50 ... Control unit (pressurization selection unit), 111,112,113 ... Electrode, 131 ... Movable plate (member) , 233 ... 1st pressurizing plate, 234 ... 2nd pressurizing plate, M ... Member to be joined, S ... Joining surface.

Claims (3)

An energization diffusion bonding apparatus for energizing and bonding a plurality of members to be bonded that are brought into contact with a bonding surface,
A plurality of electrodes sandwiching the plurality of members to be joined and electrically conducting with the plurality of members to be joined;
A power supply for supplying current to the plurality of electrodes;
A first pressurizing unit that regulates displacement in a direction that expands with respect to a direction in which the plurality of members to be bonded sandwiched between the plurality of electrodes and that applies pressure to the joint surface;
The pressure based on the elastic force of the elastic member that elastically deforms in response to the displacement in the direction of expansion with respect to the direction in which the plurality of members to be bonded sandwiched between the plurality of electrodes is sandwiched is interposed via the plurality of electrodes. A second pressure member applied to the joint surface;
A pressure selection unit that selects whether the pressure is applied to the joint surface by the first or second pressure unit ;
A temperature sensor for detecting the temperature in the vicinity of the joining surfaces of the plurality of members to be joined;
The pressurization selection unit selects whether to apply pressure to the joint surface by the first or second pressurization unit based on the temperature detected by the temperature sensor. Joining device. The first pressurizing unit regulates a position of a member to which the electrode is fixed and applies pressure to the joint surface,
The energization diffusion bonding apparatus according to claim 1 , wherein the second pressurizing unit applies an elastic force of the elastic member to the member to apply pressure to the bonding surface. It is an energization diffusion bonding method of energizing and bonding a plurality of members to be bonded that are brought into contact with a bonding surface,
Between a plurality of electrodes that are electrically conductive with the plurality of members to be bonded by restricting displacement in a direction of expansion with respect to a direction in which the plurality of members to be bonded are sandwiched and applying pressure to the bonding surface Sandwiching the member to be joined,
Supplying current to the plurality of electrodes;
When the temperature in the vicinity of the bonding surfaces of the plurality of members to be bonded exceeds a preset temperature, the displacement restriction of the plurality of members to be bonded is released, and the plurality of members to be bonded sandwiched between the plurality of electrodes An electric current diffusion bonding characterized in that a pressure based on an elastic force of an elastic member that elastically deforms in response to a displacement in a direction of expansion with respect to a sandwiched direction is applied to the joint surface through the plurality of electrodes. Method.

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