[0001]The present disclosure, in the bonding of a plurality of metal plates, relates the mechanical bonding apparatus can be used when the deformation resistance of the metal plate is large, particularly, tensile plurality of metal plates strength of the above high strength steel sheet 780MPa when comprising more than one, or both small tensile strength of the metal plate relate mechanical bonding apparatus that can be used when machining speed is high.
Background technique
[0002]
　In recent years, in the automotive field, lower fuel consumption and CO 2 in order to reduce emissions, while the vehicle body weight, for the improvement of collision safety, are required to the vehicle body member with high strength. To satisfy these requirements, it is effective to use a high strength steel sheet such as a vehicle body or parts. Therefore, there is an increasing demand for high-strength steel sheet. To use the high-strength steel sheet, such as a vehicle body or parts, it is necessary to join the high-strength steel plate and other metal plates, in this bonding, has the following problems.
[0003]
　Conventionally, such attachment of the body assembly and parts, mainly, have been carried out by spot welding, also joining of a plurality of metal plates including a high-strength steel sheet is performed by spot welding. Such, by superimposing a plurality of metal plates, in the joint formed by spot welding, the tensile strength is an important property. The tensile strength, the tensile shear strength is measured by a load tensile shear direction (TSS), there is a cross tensile strength (CTS) to be measured by a load tensile peeling direction.
[0004]
　270 CTS spot welded joint formed by a plurality of steel plates having a tensile strength of ~ 600 MPa increases with increasing strength of the steel sheet. Accordingly, the spot welding joint is formed by a steel sheet having a tensile strength of 270 ~ 600 MPa, problems with joint strength is unlikely to occur. However, in the spot welded joint formed by a plurality of metal plates including more than one sheet of steel plate having a tensile strength of at least 780 MPa, even if increase the tensile strength of the steel sheet, CTS is either not increase or decrease. This is possible due to the high content of it and alloying elements increases the stress concentration to the weld portion due to a decrease in deformability, by and solidification segregation is baked into the weld toughness of the weld is reduced There is a reason.
[0005]
　Therefore, at the junction of a plurality of metal plates including a steel sheet having a tensile strength of at least 780MPa or one, a technique for improving the CTS is needed. As one of techniques for solving it, there is a mechanical bonding technique for bonding without melting the base metal. Specifically, overlay a plurality of metal plates are a material to be joined, the rivet while holding the outer circumference of the punch plate presser for preventing jumping of the metal plate, driving the rivet punch, a plurality of metal plates are in there is a technique of mechanically joined.
[0006]
　However, in this technique, for driving the rivet, deforming the die side of the steel sheet becomes very large, the ductility missing or deformed localized problem cracking occurs in the steel plate of the die side, tensile shearing direction and the peeling direction If the stress is applied, rivets fracture occurs missing, a problem that sufficient value is obtained for the tensile strength of the shearing direction and the peeling direction, and the joint of the joint and soft steel plate of high-strength steel sheet of the same riveting system , when comparing the fatigue strength of both, there is a problem that almost no difference.
[0007]
　As a technique for solving such a problem, Patent Document 1, the high-strength steel sheet of the superimposed tensile strength 430 ~ 1000 MPa, passed through by implanting rivet by deforming the leading end of the rivet passed through the machine to be joined, joining techniques to obtain a high strength steel sheet excellent in tensile properties and fatigue properties are disclosed. The technique disclosed in Patent Document 1, the tensile strength have been considered for high-strength steel sheet of up to 619MPa, which is effective as a technique for joining a plurality of steel plates. However, in Patent Document 1, with respect to a plurality of steel plates containing at least tensile strength 780MPa high strength steel sheet, the application of the technique has not been studied.
[0008]
　Further, Non-Patent Document 1, at the junction of the high-strength steel sheet and aluminum alloy sheet, when mechanically bonded by implanting rivets, to a plurality of metal plates including a high-strength steel sheet of about tensile strength 590MPa is , can be joined without defect, the plurality of metal plates including a high-strength steel sheet of a tensile strength 980 MPa, rivet is described as not able to penetrate the high-strength steel sheet.
[0009]
　In this way, by implanting rivet metal plate mechanically joining techniques, usually without the drilling in the welded material prior to bonding, it is necessary to punch the welded material in the rivet itself, deformation resistance is large steel , for example, it is mechanically joined by implanting rivet into a plurality of metal plates including more than one sheet of steel plate having a tensile strength of at least 780MPa had been difficult.
[0010]
　In contrast, Patent Document 2, or high work hardening has been bonded sheet having a high strength, a method for joining using rivets, start or just before the joining process, pressing member and the die, or pressing members and component disposed near the die, or by component disposed before a mechanical joining method local and heating temporally limit of the bonding sheet, carried out by electrical resistance heating There has been disclosed.
[0011]
　Thus, Patent Document 2 describes a technique that can be applied to or higher work hardening steel sheet having a high strength, a plurality of metal plates a tensile strength 780MPa or more high-strength steel sheet containing more than one with respect to it is considered to some extent an effective technique also. However, using the technique disclosed in Patent Document 2, in fact, when a plurality of metal plates including tensile strength 780MPa or more high-strength steel sheet more one were joined by rivets, may not be riveted, in addition, there is room for improvement. The tensile strength be a metal plate of less than 780 MPa, the processing speed during the riveting increases, deformation resistance of the metal plate is increased, there is room for improvement as well.
CITATION
Patent Literature
[0012]
Patent Document 1: JP 2000-202563 Patent Publication
Patent Document 2: JP-T 2004-516140 Patent Publication
Patent Document 3: JP 2007-254775 JP
Non-Patent Document
[0013]
Non-Patent Document 1: Ferrum, Vol. 16 (2011) No. 9, p. 32-38
Summary of the Invention
Problems that the Invention is to Solve
[0014]
　The present disclosure, in view of the current state of the prior art described above, provided at the junction of a plurality of metal plates, even if the deformation resistance of the metal plate is large, the mechanical bonding apparatus and mechanical bonding method can stably rivet an object of the present invention is to.
Means for Solving the Problems
[0015]
　Accordingly, the present inventors have intensively studied how to solve the above problems. In the technology disclosed in Patent Document 2, the heating temperature of the steel sheet and 35 ~ 250 ° C., was complete the heating of the steel sheet before driving of the rivet. Accordingly, the present inventors have found that when the deformation resistance of the metal plate is large, when the riveted was conceived implanting rivet while heating a plurality of metal plates.
[0016]
　As a result, cracking of the metal plate, rivets damaged or rivet blind and has found that it does not. Then, while by implanting rivets plurality of metal plates, by energizing between Itaosae and die it was conceived to raise the temperature of the plurality of metal plates.
[0017]
　Mechanical bonding apparatus and mechanical bonding method of the present disclosure has been made based on the above findings, it is an gist is as follows.
(1) a mechanical bonding apparatus driving a rivet by punching a plurality of metal plates,
　a punch and die,
　and Itaosae,
　a first power supply device,
　comprising a
　said punch and die superimposed as can be sandwiched between a plurality of metal plates, are arranged to face each other,
　said plate presser is insertable tubular body the punch therein, one end portion of said plate presser, in contact with the punch side of the metal plate of the plurality of metal plates, said possible pressing a plurality of metal plates and consists of a current heatable electrode material,
　the punch is a material capable of driving a rivet is configured,
　the die, said plurality of metal plates is composed of a supportable and energizing heatable electrode material,
　said first power supply, the punch at the same time as the start driving of the rivet by, the plurality above the temperature of the metal plate It starts the power distribution to the plate retainer and die so that is configured to energize the plate retainer and the die to the end driving of the rivet,
　a mechanical bonding apparatus.
(2) further comprising mechanical joining device a cooling device, the cooling device, the are connected to the punch until completion driving from the start driving of the rivet, it is configured to cool the rivet are, mechanical bonding apparatus according to (1).
(3) the punch, capable driving the rivet and is composed of a current heatable electrode material, such that the second power supply, a heat treatment by energizing the rivet after typing the rivet by the punch, wherein being configured to energize the punch and die,
　said mechanical bonding apparatus further comprises a cooling device, the cooling device is configured to cool the rivet after the heat treatment of the rivet,
　the ( mechanical bonding apparatus according to 1) or (2).
(4)
　of the die, the material of the rivet portion opposite to sandwiching between at least the plurality of metal plates are tool steel, the material of the outer peripheral portion of the tool steel is copper or a copper alloy, (1) mechanical bonding apparatus according to any one of - (3).
(5) a mechanical joining method of implanting rivet by the punch on a plurality of metal plates,
　providing a plurality of metal plates,
　between the punch disposed opposite and die, said plurality of metal placing superposed plate,
　one end portion of the plate pressing is insertable tubular body the punch inside, is pressed against the punch side of the metal plate of the plurality of metal plates,
　the plates said plurality of metal plates pressed by the pressing, implanting rivet by said punch, and
　at the same time as the start driving of the rivet, so as to raise the temperature of a plurality of metal plates, the plate retainer and the die through it, said plurality of starts energization heating of the metal plate, by energizing heating the plurality of metal plates to the end driving of the rivet
　including a mechanical joining method.
(6) until the completion of implantation from the start driving of the rivet, further comprising cooling said rivet through said punch, the mechanical bonding method according to (5).
(7) after implantation of the rivet, via the punch and the die, and a heat treatment by energizing heating the rivet, then comprises cooling the rivet, the machine according to (5) or (6) joining method.
(8) of the die, is said rivet portion opposite to the material is tool steel sandwiched between at least the plurality of metal plates, the material of the outer peripheral portion of the tool steel is copper or a copper alloy, mechanical bonding method according to any one of (5) to (7).
Effect of the invention
[0018]
　According to the mechanical joining system and mechanical bonding method of the present disclosure, even if the deformation resistance of the metal plate is large, it is possible cracking of the metal plate, rivets breakage, and obtaining a bonded joint without causing a rivet blind.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
[1] Figure 1 is a schematic sectional view showing the form of a mechanical joint. 1 (a) is a cross-sectional schematic view showing a state of starting at the same time the plate sets of electrically heating the starting driving of the rivet, FIG. 1 (b), a cross-sectional schematic view showing the state after implantation of the rivet it is.
FIG. 2 is a schematic sectional view showing the form of a mechanical joint. 2 (a) is a cross-sectional schematic view showing a state of starting at the same time the plate sets of electrically heating the starting driving of the rivet, FIG. 2 (b) were electrically heated rivets after implantation of the rivet it is a cross-sectional schematic view showing the state.
FIG. 3 is a schematic sectional view showing the form of mechanical bonding in the case of using a tool steel to a portion of the die. 3 (a) shows, in the case of using a tool steel to a portion of the die, a cross-sectional schematic view showing a state in which the starting driving of the rivet to be electrically heated plate set at the same time, FIG. 3 (b), when using a tool steel to a portion of the die, it is a cross-sectional schematic view showing a state of electrically heating the rivet after implantation of the rivet.
DESCRIPTION OF THE INVENTION
[0020]
　The present inventors used the technique disclosed in Patent Document 2, a tensile strength of 780MPa or more high-strength steel sheet (hereinafter, "high-strength steel sheet" as referred to) a plurality of metal plates including (hereinafter "plate assembly also referred to) was electrically heated plate set by applying a current between the die installed in the opposite side of the plate presser and punch disposed so as to sandwich the a ", when implanted rivets, may not be riveted there were. The tensile strength in the case of using a metal plate for only less than 780 MPa, was increased machining speed during riveting, the deformation resistance of the metal plate is increased, there may not be riveted.
[0021]
　When present inventors, the technology disclosed in Patent Document 2, which was the heating temperature of the steel sheet and 35 ~ 250 ° C., focuses on the fact that end the heating of the steel sheet before driving of the rivet is riveted, plate It was conceived to be driven rivets while heating the set.
[0022]
　The present inventors have implanted rivet while heating to a plate set of combinations of various metal plate was investigated the relationship between such rivets damage. As a result, simultaneously with the start driving the rivet into a plate assembly, by increasing the plate set of temperature it was found that can be stably rivet connection. Furthermore, in order to increase the plate set temperature, and conceived by energizing between the Itaosae and die, mechanical bonding apparatus of the present disclosure (hereinafter, also referred to as "joining apparatus") it was found.
[0023]
　The present disclosure provides a mechanical bonding apparatus driving a rivet by punching a plurality of metal plates,
　a punch and die,
　and Itaosae,
　a first power supply device,
　comprising a
　said punch and die, overlay and so can be sandwiched between a plurality of metal plates, are arranged to face each other,
　said plate presser, the is punch insertable tubular body therein, one end portion of said plate presser , said plurality of contacting with the punch side of the metal plate of the metal plate, is composed of a plurality of metal plates to allow pressing and energizing heatable electrode material,
　the punch is capable of driving the rivet material in the configuration,
　the die, said plurality of metal plates is composed of a supportable and available electrical heating electrode material,
　said first power supply, the punch at the same time as the start driving of the rivet by the plurality temperature of the metal plate The energization of the plate retainer and die begin to increase, until the end driving of the rivet is configured to energize the plate retainer and die,
　directed to a mechanical bonding apparatus.
[0024]
　Hereinafter, with reference to the accompanying drawings, illustrating a bonding apparatus of the present disclosure. For convenience of explanation, the upper punch side, the die-side as the lower punch side of the metal plate upper metal plate, but refers to the die side of the metal plate and lower metal plate, joining device as long as it can be fixed, vertical, direction, such as horizontal placement does not matter.
[0025]
　(Embodiment 1)
　FIG. 1 shows a schematic sectional view showing the form of mechanical junctions with mechanical bonding apparatus of the present disclosure. 1 (a) is a cross-sectional schematic view showing a state of starting at the same time the plate sets of electrically heating the starting driving of the rivet, FIG. 1 (b), a cross-sectional schematic view showing the state after implantation of the rivet it is.
[0026]
　As shown in FIG. 1 (a), in the mechanical connecting apparatus 1, so that it can sandwich the upper metal plate 2 and the lower metal plate 3 is a plate pair 4 superposed, facing the punch 5 and the die 6 is arranged. The outer periphery of the punch 5, Itaosae 7 is arranged.
[0027]
　Mechanical bonding device 1, simultaneously with the start of driving of the rivet 8 the punch 5, so as to raise the temperature of the plate assembly 4, without first power supply (shown for energizing the Itaosae 7 and the die 6 ) a.
[0028]
　Implantation and initiation of rivets 8, means a time when the rivet 8, which are discharged by the punch 5 is in contact with the punch side of the metal plate of the plate assembly 4.
[0029]
　Simultaneously with the start of driving of the rivet 8, by electrically heating the plate assembly 4 may be cracks in the metal plate, rivets breakage, and obtaining a bonded joint without causing a rivet blind. Since heating the plate pairs from the start riveting, in comparison with the case where heated before implantation, tends to limit the plate sets of the heating region in the junction region, to suppress the plate set of softening of the non-bonding region it can. Therefore, it is possible to prevent the deterioration of the plate sets of the metal structure. In particular, when a 780MPa or more high strength steel sheet as a metal plate, while suppressing the strength reduction of the steel sheet, it is possible to perform bonding.
[0030]
　The first power supply is connected to Itaosae 7 and the die 6, and is configured to electrically heating the plate pair 4. The first power supply may comprise a first control unit (not shown) for controlling the quantity of electricity (current value and the energization time) for energizing the Itaosae 7 and the die 6, to heat the plate assembly 4 .
[0031]
　The first control device, simultaneously with the start of driving of the rivet 8, so as to raise the temperature of the plate assembly 4, and starts energizing the Itaosae 7 and the die 6, to the end driving of the rivet 8, Itaosae 7 and controlling that energized the die 6 for electrically heating the plate pair 4 to a desired temperature.
[0032]
　Electrical heating of the plate assembly 4 begins with the start driving of the rivet 8. Electrical heating of the plate assembly 4, after the end driving of the rivet 8 also continues, although thereafter may be stopped, preferably, it stops driving of the rivet 8 ends substantially simultaneously.
[0033]
　Implantation and the end of the rivet 8, can be moved in the driving direction of the punch means the time when substantially stopped, it is detected by detecting the position of the punch. Method of detecting the position of the punch is not particularly limited, for example, it can be carried out using a device for detecting the position from the rotational speed of the ball screw to push the non-contact laser displacement meter or punch.
[0034]
　Riveting rate is preferably 1 mm / sec or more, more preferably 10 mm / sec. Riveting rate can be adjusted according to the tensile strength and the like of the plate set of metal plates.
[0035]
　The time to the end driving from the start driving of the rivet 8, may be adjusted material of the metal plate used in a plate assembly, thickness, number of sheets and the like, preferably 0.3 to 2.0 seconds, more preferably from 0.5 to is 1.4 seconds.
[0036]
　The heating temperature of the plate assembly 4 is improved plate set of ductility, cracking of metal plate such as a steel plate rivets breakage, and while suppressing the rivet blind, may be a temperature range which can drive a rivet. That is, the lower limit of the heating temperature of the plate assembly 4, cracking of the metal plate, rivets damaged, and may be set to a temperature capable of suppressing the rivet blind. The upper limit of the heating temperature of the plate assembly 4 may be a temperature below the melting point of the highest melting point is lower metal plate in the plate pair 4.
[0037]
　The lower limit of the heating temperature of the plate assembly 4 is preferably 400 ° C. or higher, more preferably 500 ° C. or higher, more preferably 600 ° C. or higher. The upper limit of the heating temperature of the plate assembly 4 is preferably 900 ° C. or less, more preferably 800 ° C. or less. The heating temperature of the plate assembly 4, the temperature of the end driving, the measuring point is the riveting positions of the surface of the upper metal plate in surrounded by Itaosae 7 region. The surface temperature of the upper metal plate, for example, can be measured using a thermocouple. Surface temperature measurement of the upper metal plate, before preparing a rivet, may be performed in advance. If advance for surface temperature measurement of the upper metal plate, when implanted by holding the rivet punch, it is possible to omit the temperature measurement.
[0038]
　Current for energizing the heating plate assembly 4, the plate assembly 4 within the time from the start to the end driving to heat within the temperature range can be controlled by the first control device. The first control unit may control the current flowing through the plate assembly 4, for example 8 ~ 14 kA or 10 ~ 12 kA. The first controller may be substantially the same control time to end driving the energization time from the start driving of the rivet 8.
[0039]
　The first controller may be rivets 8 detects the time in contact with the plate group 4, and controls the first power supply to start energizing the Itaosae 7 and the die 6. To rivet 8 detects the time in contact with the plate group 4, for example, a voltmeter rivet 8 detects a change in voltage between the punch 5 and the die 6 when in contact with the plate group 4, the punch 5 it can be used incorporating a load cell and the like.
[0040]
　The first power supply device is not limited in particular, the power conventionally used, can be, for example, a DC power supply or AC power supply.
[0041]
　The first control device is not limited in particular, can contain a known temperature controller. The first controller may control the quantity of electricity using a temperature controller comprising a thermometer for measuring the temperature of the plate assembly 4, energizing the Itaosae 7 and the die 6. Obtained in advance the relationship between the current value and the time at which the desired temperature in accordance with the combination of the metal plate of the plate assembly 4, the first control unit may control so that the current value and time .
[0042]
　Punch 5 may be a rod-like cross-sectional shape perpendicular to the longitudinal direction of the punch 5 is not limited in particular, circular, elliptical, it can be located in such as a rectangular shape. Punch 5 may have a different cross-sectional shapes in the longitudinal direction.
[0043]
　Punch 5, if the one having a strength capable of driving the rivet 8, can be the material is not particularly limited, is selected from materials having the desired mechanical strength. Punch 5 is preferably a Vickers hardness Hv of 300 to 510, composed of steel, copper, or copper alloy. When using even the punch as the electrode body, the punch 5 is preferably electric conductivity is constructed from high copper or a copper alloy.
[0044]
　Die 6, if the present invention is composed of the electrode material having a mechanical Tsuyoo and electrical conductivity a and plate assembly 4 can support a plurality of metal plates can be electrically heating, the material it can is not particularly limited, selected from desired material. Die 6 is preferably a copper or copper alloy.
[0045]
　The outer periphery of the punch 5, Itaosae 7 is arranged. Itaosae 7, the one end plate assembly 4 punch 5 side in contact with the metal plate plate sets 4 is a member which can be pressed against the die 6, along the longitudinal axis of the punch 5, the relative it can be moved. The shape of Itaosae 7 is a cylindrical body, such as a cylindrical punch 4 is inserted therein.
[0046]
　Itaosae 7, if the present invention is composed of the electrode material having a mechanical strength and electrical conductivity can be and conduction heating can be pressed against a plurality of metal plates to the die 6, the material is particularly limited not, it can be selected from the desired material. Itaosae 7 is preferably copper or a copper alloy.
[0047]
　Punch 5, the die 6, the composition of the copper alloy Itaosae 7, and may be used in the cooling pipes 9 is preferably chromium copper alloy or alumina dispersed copper alloy. The composition of the chromium copper alloy is preferably 0.4 ~ 1.6% Cr-Cu, more preferably 0.8 ~ 1.2% Cr-Cu, for example, 1.0% Cr-Cu, alumina dispersed copper the composition of the alloy, preferably ~ 1.0% 0.2 Al 2 O 3 -Cu, more preferably ~ 0.7% 0.3 Al 2 O 3 -Cu, eg% Al 0.5 2 O 3 - is Cu.
[0048]
　The distal end of the punch 5, the rivet 8 is arranged. The rivet 8 is what is driven into the plate assembly 4 by the punch 5 may be a general-purpose products of rivets, or the like can be used full tubular rivet. The material of the rivet 8 can not limited in particular as long as it can be bonded dedicated to the plate assembly 4, for example, mechanical structural steel, high hardness steel.
[0049]
　Before implantation, the rivet 8, while being supported by the state or a suitable supporting member supported on the punch 5 may be disposed above the plate assembly 4.
[0050]
　Method for instructing the punch 5 to the rivet 8 or a suitable support member is not particularly limited, for example, may be mechanically held, magnetically attaching rivet 8 the punch 5 and the support member, as a material having a magnetic force it may be held by.
[0051]
　Die 6 disposed punch 5 and opposite to have a dish-shaped or concave pressing restraining surface 11 corresponding to the shape and size of the legs of the rivet 8 to implant, protruding substantially frustoconical central portion thereof part 12 may have. Top portion of the protruding portion 12 may be slightly lower than the upper surface of the die 6. Root portion side of the projecting portion 12 may have a smooth arcuate surface so as to be continuous to the bottom of the restraint surface 11 pressed.
[0052]
　Plate pairs 4, which are discharged rivets using the apparatus of the present disclosure may be configured by two upper metal plate 2 and the lower metal plate 3 may include three or more of the plurality of metal plates. Metal plate has a plate-shaped portion on at least a portion, as long as the plate-like portion having a stackable parts together, may not be entirely plate shape. The plate assembly 4 is not limited to those composed of separate metal plate, it may be a superposition of those forming the single metal plate into a predetermined shape, such as tubular.
[0053]
　A plurality of metal plates may be the same type of metal plates may be of different types of metal plate. The metal plate can be a metal plate having a high strength steel sheet, it can be an aluminum plate, a magnesium or the like. Steel sheet is preferably a high strength steel plate, more preferably a high-strength steel sheet having a tensile strength of at least 780 MPa. A plurality of metal plates may include a steel plate or one, a high-strength steel sheet having a tensile strength of at least 780MPa may comprise more than one. For example, the plate pair 4 is a plate set to steel all metal plates of the plate assembly 4, the upper metal plate or the lower metal plate and high-strength steel sheet, tensile another metal plate strength and steel less than 780MPa plate assembly, an upper metal plate and an aluminum plate, a lower metal plate plate sets to high-strength steel sheet, or all of the metal plate of the plate assembly 4 may be a plate pair to the aluminum plate. With the apparatus of the present disclosure, it is possible to plate assembly comprising at least one or more high strength steel sheet even better bonding with the above tensile strength 780 MPa.
[0054]
　The thickness of the metal plate is not particularly limited, for example, be a 0.5 ~ 3.0 mm. The thickness of the plate pairs is also not particularly limited and may be, for example, 1.0 ~ 6.0 mm. Also, the presence or absence of plating, well as chemical composition, not particularly limited.
[0055]
　FIG. 1, the flow of current flowing from Itaosae 7 to the die 6 is exemplified by the dotted line arrow, as long electrically heated plate set 4 may be the flow of current flowing from the die 6 to Itaosae 7. The same applies to FIGS. 2 and 3.
[0056]
　(Embodiment 2)
　As a preferred embodiment, the second embodiment will be described. Bonding apparatus of the present disclosure preferably further includes a cooling device (not shown).
[0057]
　Cooling device is connected to the punch 5, via the punch 5 until completion driving from the start driving of the rivet 8, and is configured to cool the rivet 8. While performing electrical heating plate set 4, while cooling the rivet 8 in the connected cooling device to the punch 5 can be bonded to the plate assembly 4 by implanting rivet 8 in the punch 5.
[0058]
　The plate assembly 4 between the Itaosae 7 and the die 6 when implanting rivet 8 with electrical heating, cooling the rivet 8 through the punch 5, suppressing the softening of the rivet 8 by heat plate pairs 4 it can be, can be performed more stably rivet connection. By cooling the rivet 8, in particular, when the temperature of the plate assembly 4 when implanting the rivet 8 is higher, to suppress softening of the rivets 8, the rivet 8 is prevented from becoming a blind, more it can be performed stably joined.
[0059]
　Cooling of the rivet 8 may be carried out between the end driving from the start driving of the rivet 8. That is, the cooling of the rivet 8 may be started before driving, may be started driving at the same time as the start, preferably cooling the rivet 8 starts before implantation. Cooling of the rivet 8 may be terminated implanted Upon termination, after completion of implantation may be carried out continuously, but preferably terminates driving ends substantially simultaneously.
[0060]
　Cooling device is not particularly limited as long as it can cool the rivet 8 through the punch 5, the punch 5 may have a cooling tube 9 therein. In FIG. 1 (a), are arranged inside the punch 5 is illustrated connected a cooling tube 9 to the cooling device.
[0061]
　Cooling tube 9, for example in the direction indicated by the arrow, is a tube which can be supplied to the refrigerant. The end portion of the punch 5 the rivet 8 is in contact with the other end on the opposite side, the cooling device may be provided which is connected to the cooling tube 9. The material of the cooling tube 9, by circulating a coolant therein is not particularly limited as long as it can cool the rivet through the punch 5 can be, for example, copper or a copper alloy. In this case, it is preferable that the punch 5 and high copper or copper alloy heat conductivity.
[0062]
　The refrigerant is not limited in particular, but may be a known refrigerant fluid or refrigerant gas, taking into account such economic and ease of handling, water is preferred.
[0063]
　Inside the cooling tube 9 without providing the punch 5, the cooling device so as to be in contact with the other end portion opposite arranged to the end portion of the punch 5 the rivet 8 is in contact, to cool the punch 5, the punch 5 by heat conduction, it may be cooled rivets 8. Again, it is preferable that the punch 5 and high copper or copper alloy heat conductivity.
[0064]
　Cooling of the rivet 8 may be carried out between the end driving from the start driving of the rivet 8. That is, the cooling of the rivet 8 may be started before driving of the rivet 8, may be started driving at the same time as the start, preferably cooling the rivet 8 starts before implantation. Cooling of the rivet 8 may be terminated implanted Upon termination, after completion of implantation may be carried out continuously, but preferably terminates driving ends substantially simultaneously.
[0065]
　Cooling device is provided with a control device, it is possible to control the cooling temperature as well as the timing of the cooling start and end. Controller, preferably at the end implantation, more preferably to the end driving from the start driving, so that the temperature of the rivet 8 becomes preferably 3 ~ 50 ° C., more preferably between 5 ~ 30 ° C., controlling the cooling device can do. Temperature of the rivet 8, for example, before the actual joining, pre perform preliminary tests for measuring the temperature of the rivet may have been measuring the temperature of the rivet using a thermocouple. Control device provided in the cooling device is not limited in particular, can contain a known temperature controller.
[0066]
　(Embodiment 3)
　with reference to FIG. 2, illustrating a third embodiment is a preferred embodiment. Figure 2 shows a schematic sectional view showing the form of mechanical junctions with mechanical bonding apparatus of the present disclosure. 2 (a) is a cross-sectional schematic view showing a state where the start driving of the rivet to be electrically heated plate set at the same time, FIG. 2 (b), a state of electrically heating the rivet after implantation of the rivet schematic cross-sectional views showing.
[0067]
　Mechanical bonding apparatus 1 includes, as the rivet 8 which is driven by the punch 5 is heat treated, a second power supply for energizing the punch 5 and the die 6 (not shown). Mechanical bonding apparatus of Figure 2, except that the punch 5 and the die 6 is constituted by the electrode material can be electrically heated rivet 8, with mechanical joining apparatus similar to the configuration of FIG. 1.
[0068]
　The second power supply is connected to the punch 5 and the die 6, after typing the rivet 8 by the punch 5, is configured to heat treatment by energizing the rivet 8 via a punch 5 and a die 6. The second power supply device includes a second control device for controlling the electric amount to be supplied to the punch 5 and the die 6 (the current value and the energization time) (not shown), heating the rivet 8 to the desired temperature can.
[0069]
　With the connected cooling device to the second power supply and the punch 5, after the end driving of the rivet 8, a heat treatment of heating the rivet 8 in the austenite region, then it can be cooled. Thus, the rivet 8 may have a martensite structure, it is possible to improve the strength of the rivet 8. Cooling apparatus according to an embodiment 3 may be the same as or different from the cooling device used in the second embodiment.
[0070]
　By heat treated rivets 8 after completion of driving achieve high strength, the bonded joint obtained with rivets, damage to the peripheral including rivets, can be further reduced.
[0071]
　In particular, a plate assembly including a high-strength steel sheet, even when joining the general-purpose products of rivets not high strength, and suppress the stress concentration in the low strength rivets, damage to the resulting bonded joint using a rivet it is possible to prevent more stably.
[0072]
　To increase the strength of the rivet, conventionally, by adjusting the chemical composition, there is known a technique of applying a heat treatment such as quenching (Patent Document 3). However, in this technique, the component composition of the rivet is limited, the heat treatment furnace is required for the heat treatment, resulting an increase in cost, and further, a heat treatment step of the heat treatment furnace is required, causing an increase of the rivet production time there was a problem.
[0073]
　In contrast, the punch and die driving a rivet as an electrode material, were electrically heated by applying a current to the rivet after typing in a plate pair, austenitic heat-treated rivets, i.e., the steel-made general-rivets It was heated to a temperature at which the band, with the martensite structure by quenching, it is possible to increase the strength of the rivet. Therefore, without using a heat treatment furnace or the like, it is possible to obtain a high-strength rivets.
[0074]
　The heating temperature in the heat treatment of the rivet 8 is not particularly limited as long as it can heat the rivet 8 to the austenite region, preferably heated to a temperature below the melting point of A3 point-rivet. Current value and time in heating up to a maximum temperature of the rivet 8, for example, the current value can be 8 ~ 10 kA, time is 0.1 to 1.0 second.
[0075]
　Electrical heating of the rivet 8 may start from driving end of implant ends at the same time or rivets 8 rivets 8 after a predetermined time elapses. Second control apparatus, the driving end of the implant and end at the same time or rivets 8 rivets 8 after a predetermined time has elapsed, so as to energize the heating of the rivet 8, it is possible to control the second power supply.
[0076]
　Cooling conditions after heating the rivet 8 in the austenite region is not particularly limited as long as the martensite structure is obtained, a control device included in the cooling apparatus, after heating the rivet 8 in the austenite region, preferably in a cooling rate of more than 10 ° C. / sec, martensite transformation finish temperature of the material constituting the rivet or less, typically to cool the rivet 8 to about 200 ° C. or less, it is possible to control the cooling device.
[0077]
　When doing cooling of the rivet 8 through the punch 5 when driving of the rivet 8, while performing heat treatment of the rivet 8 after implantation of the rivet 8, as long as the rivet 8 is heated to a predetermined temperature by electric heating, may be continued cooling of the rivet 8 through the punch 5, but preferably the cooling of the punch 5 reduces the stopping addition amount of cooling, after the heat treatment of the rivet 8 to increase the resume the cooling amount to the cooling rivet 8 It is cooled.
[0078]
　Punch 5, if the present invention is composed of the electrode material having a mechanical strength and electrical conductivity can be and conduction heating can drive a rivet 8, the material is not particularly limited, the desired material it is possible to select from. Punch 5 is preferably a Vickers hardness Hv is 300 to 510, configured electric conductivity from high copper or a copper alloy.
[0079]
　Die 6, if the present invention is composed of the electrode material having a mechanical strength and electrical conductivity and plate assembly can support a plurality of metal plates 4 and the rivet 8 may be electric heating, the material is not particularly limited, it may be selected from the desired material. Die 6 is preferably a copper or copper alloy. Die 6 may be made of the same material as that used in Embodiment 1.
[0080]
　The second power supply unit is not limited in particular, the power conventionally used, can be, for example, a DC power supply or AC power supply. The second power supply may have the same configuration as the first power supply.
[0081]
　The second control device is not limited in particular, can contain a known temperature controller. The second controller may use a temperature controller comprising a thermometer for measuring the temperature of the rivet 8 to control the quantity of electricity for energizing the punch 5 and the die 6. Rivet 8 is obtained in advance the relationship between the current value and time to become a predetermined temperature, the second control apparatus may control the second power supply so that the current value and time.
[0082]
　Control device provided in the cooling device, can use the temperature controller to control the cooling rate and cooling temperature after the heat treatment of the rivet 8.
[0083]
　The first power supply and the second power supply may be separate power supply may be a function of may be a power device integrated, or the first power supply is a second power supply.
[0084]
　When the first power supply and the second power supply is integral power supply, or when the first power supply also has the function of the second power supply, the power supply is Itaosae 7 and the die 6 When, it is connected to both the punch 5 and the die 6.
[0085]
　(Embodiment 4)
[0086]
　With reference to FIG. 3, an embodiment 4 is a preferred embodiment. Figure 3 shows a schematic sectional view showing the form of mechanical bonding with mechanical joining device comprising a tool steel to a portion of the die. 3 (a) shows, in the case of using a tool steel to a portion of the die, a cross-sectional schematic view showing a state of electrically heating the plate pair before driving of the rivet, FIG. 3 (b), die when using a tool steel to a part of a cross-sectional schematic view showing a state of electrically heating the rivet after implantation of the rivet. Mechanical bonding device of Figure 3, except that the die 6 is constituted by a tool steel die 6a and copper or copper alloy die 6b, have a mechanical joint system similar to the configuration of FIG. 2.
[0087]
　To suppress the deformation of the die, of the die, it is effective to increase the strength of the rivet portion facing the (lower part of the portion where the rivet 8 is driven) in between the plate pairs 4. Therefore, as shown in FIG. 3, of the die 6, a portion for restraining a lower metal plate 3 which may be deformed by the rivet 8 is driven by a tool steel die 6a, the strength of the die 6 It can be increased, thereby suppressing the deformation of the die 6.
[0088]
　When driving a rivet into a plate pair, it is energized between the Itaosae and die, or implanted it is energized between the punch and the die to the heat treatment of rivets, die is heated. In this case, the material of the die are all tool steels, die tends to soften. Therefore, preferably, the outer peripheral part of the tool steel dies 6a, from the viewpoint of easy current flow, composed of copper or a copper alloy.
[0089]
　So as to surround the circumference of the tool steel die 6a, by placing a lower copper or copper alloy die 6b electric resistance, when energized between Itaosae 7 and the die 6, or punch 5 and when energized with the die 6, the current flows preferentially to lower outer peripheral portion of the electric resistance, tool steel die 6a is hardly heated, it is possible to prevent the softening.
[0090]
　When forming part of the die 6 tool steel, of a die 6, the portion facing the rivet 8 in between at least the plate assembly 4 may be composed of tool steel, but in between the plate pairs 4 in a part of Itaosae 7 a portion facing may be constructed of tool steel. However, among the die 6, as the proportion of the portion constituted of copper or a copper alloy is reduced, since the current tool steel flows through the tool steel is likely to soften during or punch the Itaosae 7 and the die 6 5 and in accordance with the energization amount between the die 6, it is possible to adjust the proportion between the portion constituted by the formed part and the copper or copper alloy tool steel.
[0091]
　The present disclosure also provides a mechanical joining method of implanting rivet by the punch on a plurality of metal plates,
　providing a plurality of metal plates,
　between the punch disposed opposite and die, said plurality of placing superposing a metal plate,
　one end portion of the plate pressing is insertable tubular body the punch inside, is pressed against the punch side of the metal plate of the plurality of metal plates,
　said plurality of metal plates which are pressed by the plate pressing, implanting rivet by said punch, and
　at the same time as the start driving of the rivet, so as to raise the temperature of said plurality of metal plates, the plate retainer and the through the die, and starts energizing the heating of the to a plurality of metal plates, by energizing heating the plurality of metal plates to the end driving of the rivet,
　comprising a mechanical bonding method (hereinafter, bonding Also referred to as the Act) to target.
[0092]
　The bonding method of the present disclosure will be described with reference to FIG.
[0093]
　Prepare a plate set 4 of a plurality of metal plates. Plate assembly 4, the tensile strength may comprise at least one or more of the high strength steel sheet 780 MPa, tensile strength may include only the metal plate below 780 MPa.
[0094]
　The plate assembly 4 is placed on the die 6, the one end portion of Itaosae 7 is a cylindrical body, pressing the metal plate the punch 5 side of the plate assembly 4, the plate set which is pressed by Itaosae 7 4, driving the rivet 8 by the punch 5.
[0095]
　To raise the temperature of the plate assembly 4, simultaneously with the start driving of the rivet 8, via the Itaosae 7 and the die 6, and starts energizing the plate assembly 4, passing a plate assembly 4 until the end driving of the rivet 8 .
[0096]
　Preferably, until the completion of implantation from the start driving of the rivet 8 to cool the rivet 8 through the punch 5.
[0097]
　Preferably, after implantation of the rivet, via a punch and die to heat treatment were electrically heated rivets.
[0098]
　Preferably, among the die, the material of the rivet portion opposite to sandwiching between at least a plurality of metal plates are tool steel, the material of the outer peripheral portion of the tool steel is copper or a copper alloy.
[0099]
　Preferably, Itaosae is, a has an insertion through hole that allows the punch, the punch is moved relative to the plate presser while the through-hole and sliding.
[0100]
　Preferably, an elastic body at the other end of Itaosae, elastic body, applies pressure pressing on a plurality of metal plates through the Itaosae.
[0101]
　By moving the punch 5 in the mobile device (not shown), it can be Itaosae 7 via the compression coil spring 14 moves together with the punch 5 makes contact with the plate group 4. As steel plates of the plate pair 4 is closely contacted at the degree of pressure the rivet 8 is stopped at a position not in contact with the plate group 4, it is possible to move the plate presser 7 against the die 6.
[0102]
　The configuration of the bonding method of the present disclosure, it is possible to apply the configuration explained in the mechanical bonding apparatus.
Example
[0103]
　(Example 1)
　using a mechanical joining apparatus 1 shown in FIG. 1, as the bonding test in the case deformation resistance of the metal plate is large, the tensile strength of the plate set including more than one of the above high strength steel sheet 780MPa bonding test It was carried out.
[0104]
　The steel sheet of thickness 1.2mm and upper metal plate tensile strength have a tensile strength of 980MPa as a high-strength steel sheet of more than 780MPa, the steel sheet of thickness 1.6mm tensile strength have a tensile strength of 440MPa as a steel sheet of less than 780MPa upper were prepared plate set 4 to the metal plate.
[0105]
　As shown in FIG. 1 (a), placing the plate assembly 4 on the copper die 6 was stuck with copper plate presser 7 presses the plate group 4. As the rivet 8 is made of hardened steel to prepare a full tubular rivet 6mm diameter it was held in the punch 5.
[0106]
　In riveting speed 10 mm / sec, at the same time by a punch 5 made of 1.0% Cr-Cu and to initiate the driving of the rivet 8 to the plate assembly 4, the Itaosae 7 and the die 6 comprises a first control device It was first a current of 10kA flows 1.0 seconds using the power supply, and heating the plate pair 4, implanted rivets 8. Temperature of the plate assembly 4 at the riveting termination was 750 ° C.. Figure 1 (b) junction, as shown in is obtained, the steel plates superimposed are completely in close contact, breakage of the metal plate, rivets damage, and without causing the rivet blind, the joining of the plate pairs It could be carried out.
[0107]
　(Example 2)
　as tensile strength plate group composed of a metal plate of less than 780 MPa, respectively as the upper metal plate and lower metal plate, providing a metal plate having a tensile strength of 590MPa and 440 MPa, the riveting speed by increasing the 20 mm / sec, except that the current of 20kA to 0.5 seconds, under the same conditions as in example 1, was subjected to bonding tests. Cracking of the metal plate, rivets damage, and without causing the rivet blind, it was possible to perform the bonding of the plate sets.
[0108]
　(Example 3)
　the cooling tube 9 shown in the temperature controller connected to Figure 1 to a cooling apparatus equipped with using a punch 5 provided inside, while cooling the rivet 8 to 30 ° C. over the punch 5, the punch 5 by implanted rivets 8, and except that heated plate set 4 up to 780 ° C., was bonded test under the same conditions as in example 1. Cracking of the metal plate, rivets damage, and without causing the rivet blind, it was possible to perform the bonding of the plate sets.
[0109]
　(Example 4)
　using a mechanical joining apparatus 1 shown in FIG. 2, except that heat-treated and cooled rivets 8 after implantation of the rivet 8 were bonded test under the same conditions as in Example 3.
[0110]
　After completion of implantation, stop cooling and heating of the plate assembly 4 of the rivet 8, the punch 5 and the die 6, the current of 8kA flow 0.5 seconds using a second power supply having a temperature controller, rivets 8 was heated to 900 ° C. in the austenite region, then up to 180 ° C. at a cooling rate of 30 ° C. / sec, and quenched using a cooling apparatus equipped with a temperature controller.
[0111]
　When checking rivet after the heat treatment, it was confirmed to have a martensitic structure. Then, was subjected to a joint strength test of the bonded joint, compared with the case of no heat treatment of the rivet, peripheral damage, including rivets it was found that a more reduced.
[0112]
　(Example 5)
　using a mechanical joining apparatus 1 shown in FIG. 3, the portion facing the rivet 8 in between the plate pairs 4 and tool steel die 6a, copper on the outer peripheral portion of the die 6a die except that disposed 6b was subjected to bonding tests under the same conditions as in example 1. It is possible to suppress the deformation of the die 6, and cracking of the metal plate, rivets damage, and without causing the rivet blind, it was possible to perform the bonding of the plate sets.
DESCRIPTION OF SYMBOLS
[0113]
　1 mechanical bonding device
　2 upper metal plate
　3 lower metal plate
　4 plate assembly
　5 punch
　5a punch of the contact portion
　5b punch sliding portion
　6 die
　6a tool steel die
　6b copper or copper alloy die
　7 Itaosae
　8 rivet
　9 cooling tube
　10 through hole
　11 pressed restraint surface
　12 protrusion
　13 movable plate
　14 holder
　15 compression coil spring
　16 hold plate
　17 molded resin
　18 guide bolt

WE CLAIM

[Claim 1]A mechanical bonding apparatus driving a rivet by punching a plurality of metal plates,
　a punch and die,
　and Itaosae,
　a first power supply device,
　comprising a
　said punch and die, a plurality of superimposed as can be sandwiched between a metal plate, is arranged opposite,
　said plates holding is insertable tubular body the punch therein, one end portion of said plate presser, said plurality wherein in contact with the punch side of the metal plate of the metal plate, said possible pressing a plurality of metal plates and consists of a current heatable electrode material,
　the punch is formed of a material capable of driving the rivet,
　said die, said a plurality of metal plates is composed of a supportable and available electrical heating electrode material,
　said first power supply, the punch at the same time as the start driving of the rivet by, the plurality of metal plates raising the temperature The plate pressing and starts the power distribution to the die, and is configured to energize the plate retainer and the die to the end driving of the rivet, the
　mechanical joining system.
[Claim 2]
　Further comprising mechanical joining apparatus a cooling apparatus, the cooling apparatus is connected to said punch, until the completion of implantation from the start driving of the rivet, and is configured to cool the rivet, wherein mechanical bonding apparatus according to claim 1.
[Claim 3]
　The punch, the configured implantation can and energization heatable electrode material rivet, as the second power supply, a heat treatment by energizing the rivet after typing the rivet by the punch, the punch and it is configured to energize the die,
　further comprising mechanical joining apparatus a cooling apparatus, the cooling apparatus, the being configured to cool the rivet after the heat treatment of the rivet,
　claim 1 or mechanical bonding apparatus according to 2.
[Claim 4]
　Among the die is sandwiched therebetween the material is tool steel of the rivet facing the portion between at least the plurality of metal plates, the material of the outer peripheral portion of the tool steel is copper or a copper alloy, according to claim 1 mechanical bonding apparatus according to any one of 1-3.
[Claim 5]
　A mechanical bonding method of implanting rivet by the punch on a plurality of metal plates,
　providing a plurality of metal plates,
　between the punch and die arranged to face, overlapping the plurality of metal plates placing together,
　one end of the plate presser is insertable tubular body the punch inside, is pressed against the punch side of the metal plate of the plurality of metal plates,
　pressed by the plate pressing said plurality of metal plates which are, implanting rivet by said punch, and
　at the same time as the start driving of the rivet, so as to raise the temperature of a plurality of metal plates, through the plate retainer and said die, It said plurality of starts energization heating of the metal plate, by energizing heating the plurality of metal plates to the end driving of the rivet
　including a mechanical joining method.
[Claim 6]
　Until completion driving from the start driving of the rivet, further comprising a mechanical bonding method according to claim 5 to cool the rivet through the punch.
[Claim 7]
　After implantation of the rivet, the punch and through the die, and a heat treatment by energizing heating the rivet, then it comprises cooling the rivet, a mechanical bonding method according to claim 5 or 6.
[8.]
　Among the die, the material of the portion facing the rivet in between at least the plurality of metal plates are tool steel, the material of the outer peripheral portion of the tool steel is copper or a copper alloy, according to claim 5 mechanical bonding method according to any one of 1-7.