JP2012101283A - Joining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining method and a joining apparatus which can join a junction member to a member to be joined with a slight press force with high reliability without detriment to working environment.SOLUTION: In the joining method, a member of lowering a melting point is placed between a stud 2 and a workpiece 3. The member of lowering the melting point is composed of a metal material capable of eutectic reaction with the metal material constructing the stud 2 and the workpiece 3. The stud 2 is rotated to generate friction heat while the stud 2 is pressed against the workpiece 3 via the material of lowering the melting point inserted therebetween. Taking advantage of eutectic reaction, the connection portions of the stud 2 and the workpiece 3 and the member of lowering the melting point are melted. Then, the rotation of the stud 2 is stopped and the stud 2 is joined to the workpiece 3. Thus, the junction member can be joined to the member to be joined with a slight press force with high reliability without detriment to working environment.

Description

  The present invention relates to a bonding method and a bonding apparatus for bonding a bonded object to an object to be bonded. Specific application fields of the joining method and joining apparatus according to the present invention include, for example, attachment of small members to large aluminum structures such as LNG tanks, attachment of small members to aluminum members of railway vehicles, automobiles, etc. There are also attachments of small parts to steel members such as bridges.

  There is an arc stud method as a conventional method for joining a joined object to an object to be joined. In the arc stud method, first, an arc discharge is generated between a joined article and a workpiece, and the joined article and the article to be joined are melted by the arc discharge, and a molten product is formed between the joined article and the article to be joined. A molten pool is formed. Next, in a state where the molten pool is formed, the bonded object is pressed against the object to be bonded, and the bonded object is bonded to the object to be bonded.

  There is a friction welding method as another conventional method for joining a joined object to an object to be joined. In the friction welding method, the bonded object is rotated while the bonded object is pressed against the object to be bonded, and frictional heat is generated between the bonded object and the object to be bonded, and the joint between the bonded object and the object to be bonded is plastic. The joined object and the article to be joined are joined by causing deformation (see, for example, Patent Document 1).

  There is brazing as another conventional method for joining a joined object to an object to be joined. In brazing, a brazing material having a melting point lower than that of the joined article and the article to be joined is disposed between the joined article and the article to be joined, and the brazing material is melted to join the joined article and the article to be joined. (For example, refer to Patent Document 2).

  However, the arc stud method has a problem that defects such as cracks and blowholes occur in the course of solidification of the molten pool, the quality of the welded portion and the variation in bonding strength tend to increase, and the bonding reliability is low. In addition, in order to perform the arc stud method, an auxiliary device such as a gun for performing welding, a welding power source for applying voltage and a device for supplying a shielding gas for preventing oxidation, etc., and wiring of these auxiliary devices And piping is necessary. In addition, an oxide film removal process, a stud bonding process, and a ferrule removal process before bonding are necessary, and the number of processes is large.

  The friction welding method is a stable method that is not affected by a change in posture, but in order to cause plastic deformation, it is necessary to press the bonded product against the workpiece with a pressing force of several hundred kg to ton order. Therefore, the friction welding method can be applied only to the joint that can withstand such a pressing force and the joint to be joined. For example, a joint having a small strength that buckles due to the pressing force can be applied to the friction welding method. Then, there is a problem that it cannot be joined. In addition, since the joining apparatus becomes large, it is difficult to carry the apparatus into an existing structure for construction. The generated frictional heat is proportional to the product of the relative speed and the pressing force. When the joint has a small diameter, the relative speed is low, and thus a particularly large pressing force or ultra-high speed rotation is required.

  In the brazing of aluminum, a step of removing the oxide film on the part to which the brazing material of the joined article and the article to be joined adheres is required. A strong active flux is often used to remove the oxide film. If this strong active flux remains, it causes corrosion of the joint portion. Therefore, in brazing, there is a problem that a step of removing the strong active flux is further required and the number of steps is increased. Further, since the difference in melting point between the brazing material and the base material is small, it is necessary to braze within a temperature range of about ± 5 ° C. Therefore, brazing is generally applied to aluminum alloys that have a narrow melting temperature range and a relatively large melting point difference with the brazing material, and have a wide melting temperature range and a relatively small melting point difference with the brazing material. It is difficult to apply to a high-strength aluminum alloy having a high content of Mg, Zn, Si and the like.

Japanese Patent Laid-Open No. 2002-153979 JP 2002-290068 A

  Therefore, an object of the present invention is to provide a bonding method and a bonding apparatus that can bond a bonded object to an object to be bonded with a small pressing force, high reliability, and without deteriorating the working environment.

In order to solve the above problems, the bonding method according to the present invention is:
Between each of the bonded object and the bonded object each formed of a metal material, the melting point lowering member of at least one of the bonded object and the bonded object is disposed,
Friction heat is generated by giving a relative motion between the bonded object and the bonded object in a state where the bonded object is pressed against the bonded object via the melting point lowering member, Melting at least one of the bonding object and the bonded object and the melting point reducing member at a temperature lower than the melting point of at least one of the bonded objects;
Relative motion between the bonded object and the object to be bonded is stopped, and the bonded object is bonded to the object to be bonded.

  Preferably, the present invention is characterized in that the bonded object and the bonded object are formed of the same type of metal material.

  Preferably, the present invention is characterized in that the metal material is aluminum.

  Preferably, the present invention is characterized in that a relative motion is given between the bonded object and the bonded object by rotating the bonded object.

  Preferably, the present invention is characterized in that the bonded article has a columnar shape, and a tip portion pressed against the bonded article is formed in a tapered shape.

Preferably, the present invention detects a load when causing relative movement between the bonded object and the bonded object,
Based on the detected load, the relative movement between the bonded object and the bonded object is stopped.

In order to solve the above-described problems, a bonding apparatus according to the present invention includes:
A gripping means for gripping a joint formed of a metal material;
A rotation driving means for rotating the gripping means in a state of gripping the bonded article;
A displacement driving means for displacing and driving the gripping means in a state of gripping the bonded article;
Control means for controlling the drive of the rotation drive means and the displacement drive means,
The control means includes
The rotational driving means is controlled with a melting point lowering member of at least one of the bonded object and the bonded object disposed between the bonded object and the bonded object formed of the metal material. Then, while the gripping means is rotated, the displacement driving means is controlled so that the gripping means presses the joined object against the joined object to generate frictional heat between them, and the joined article and the joined article Melting at least one of the joined article and the article to be joined and the melting point lowering member at a temperature lower than the melting point of at least one of the articles, The rotational drive is controlled to stop, and the joined article is joined to the article to be joined.

Preferably, the present invention further includes load detection means for detecting a load when the rotation driving means rotationally drives the gripping means,
The control means controls the rotation drive means based on the load detected by the load detection means to stop the rotation drive.

  Preferably, the present invention further includes supply means for disposing the melting point lowering member between the bonded object and the bonded object.

Preferably, the present invention further includes posture detection means for detecting an inclination with respect to the vertical direction,
The control means controls the displacement driving means based on a detection result of the posture detecting means so that a resultant force of gravity and a force applied by the displacement driving means becomes a predetermined force.

  According to the bonding method and the bonding apparatus of the present invention described above, at least one of the bonded object and the bonded object is first formed between the bonded object formed of metal and the bonded object formed of metal. One melting point lowering member is arranged. The melting point lowering member is formed of a metal material that undergoes a eutectic reaction with at least one of the bonded object and the bonded object. Next, in a state where the melting point lowering member is interposed, a relative motion is given between the bonded object and the bonded object while pressing the bonded object against the bonded object. As a result, frictional heat is generated in the portion where the bonded object and the bonded object are abutted. This frictional heat raises the temperature of the friction surface, and a liquid phase is generated by the eutectic reaction only at the site where at least one of the bonded object and the bonded object contacts the melting point reducing member. The relative movement is stopped after a sufficient liquid phase has been formed between the bonded object and the bonded object. Further, as an optional step, upset pressurization can be performed by controlling the displacement driving means. Thereby, the liquid phase of a friction surface is discharged | emitted, and both can be joined because the active new surfaces of a to-be-joined object and a to-be-joined object are faced | matched.

  In the present invention, since the region where friction occurs can be locally heated and the melting range can be locally limited, when the molten pool formed like the arc stud method of the prior art solidifies, cracking occurs. In addition, the occurrence of defects such as blow holes can be suppressed, and highly reliable bonding can be realized. Further, since a power source for generating arc discharge and a device for supplying shield gas are not required unlike the arc stud method, the cost of the device for realizing the joining method can be greatly reduced. Furthermore, compared with the arc stud method, since it can join without generating an arc discharge, it can join by energy saving. Furthermore, since harmful ultraviolet rays and fumes generated by arc discharge are not generated, the work environment can be prevented from deteriorating, and the joining work can be performed in a clean environment.

  Further, in the conventional friction welding method, a large pressing force is required to cause plastic deformation, but in the present invention, the melting point of the metal material forming the joined object and the object to be joined are formed by lowering the melting point. Since the object to be bonded and the object to be bonded can be melted at a temperature lower than the melting point of at least one of the melting points of the metal material to be compared, (i) lowering the rotational speed compared to the friction welding method, (ii) It is advantageous in reducing the pressing force, or (iii) reducing the rotational speed and reducing the pressing force, and requires a large-scale device for generating a large pressing force. do not do. Furthermore, in the present invention, since the welding can be realized with a small pressing force compared to the friction welding method, the friction welding method cannot withstand the pressing force, and the bonding is small so that the friction welding method cannot be applied. Even an object can be bonded to an object to be bonded. Further, since the region where friction occurs can be locally heated and the melting range can be limited locally, even when the shape of the joint surface between the joint and the joint is different, the joint is covered. Can be joined to a joint.

  Further, according to the present invention, for example, the bonding of the bonded object formed by the same type of metal material and the object to be bonded can be performed with energy saving while greatly reducing the cost of the apparatus as described above. In addition, when the structure of the device does not become large like a device that performs friction welding, a small object that cannot be bonded by the friction welding method can be bonded, and the shape of the bonded object and the object to be bonded are different. Even so, the bonded object can be bonded to the object to be bonded, the work environment can be prevented from deteriorating, and highly reliable bonding can be performed in a clean environment.

  Further, according to the present invention, for example, the joining of the joined object formed of aluminum and the object to be joined can be performed with energy saving while greatly reducing the cost of the apparatus as described above, and the friction welding can be performed. It is possible to join a small joint that cannot be joined by the friction welding method, and the shape of the joint and the object to be joined are different. The bonded object can be bonded to the object to be bonded, the work environment can be prevented from deteriorating, and highly reliable bonding can be performed in a clean environment.

  Further, according to the present invention, for example, since the relative motion is given by rotating the joined object, the region where the frictional heat of the object to be joined can be made as narrow as possible, and the region where the influence of joining is possible is possible. It can be as narrow as possible. For example, the region where the frictional heat is generated can be narrowed as compared with the case where the joined object is slid while being pressed against the article to be joined and reciprocated. This makes it possible to make the region where the influence of the joining occurs as small as possible.

  Furthermore, according to the present invention, for example, the joined object is a columnar shape, and the tip portion pressed against the object to be joined is formed in a tapered shape. This is to make the frictional heat generated on the friction surface uniform. If the joint is completely cylindrical and the tip is formed in a flat surface, when the joint is rotated, the rotational speed is more outward when the joint is rotated radially inward and outward. Get higher. Friction heat is expressed as the product of pressure, relative speed, and friction time, so the outer side in the radial direction with a higher rotational speed is heated than the inner side with a lower rotational speed, and the temperature at the time of joining is higher. Variations occur and bonding reliability decreases. In a tapered joint, the tip is first heated and melted, and the region radially outward is sequentially pressed against the work piece and melted by frictional heat, so that all the parts to be melted can be melted. That is, the radially inward direction where the rotational speed is low is rubbed at a high pressure for a long time, and the radially outward direction where the rotational speed is high is rubbed at a low pressure for a short time. As a result, variations in temperature during bonding can be suppressed, and highly reliable bonding can be realized.

  Further, according to the present invention, for example, a load when a relative motion is given between the joined object and the object to be joined is first detected, and then a relative between the joined object and the object to be joined is based on the detected load. Stop exercise. The load when the relative motion between the bonded object and the object to be bonded is given depends on the molten state of the bonded object and the object to be bonded. In the present invention, since the melt state can be indirectly confirmed simply by detecting the load, the timing for stopping the relative motion is determined without directly detecting the melt state such as the temperature and the melted part. Can do.

  Further, according to the present invention, for example, the above-described joining method is executed by the joint being gripped by the gripping means, and the rotation driving means and the displacement driving means whose drive is controlled by the control means driving the gripping means. A joining device is realized. Since this joining apparatus executes the joining method of the present invention described above, the construction of the apparatus is large as in the case of joining by energy saving and friction welding as described above while greatly reducing the cost of the apparatus. Therefore, it is possible to join small joints that cannot be joined by the friction welding method, and join the joints to the joints even if the joints and the joints have different shapes. It is possible to prevent deterioration of the working environment and perform highly reliable joining in a clean environment.

  Furthermore, according to the present invention, for example, the load when the displacement driving means rotationally drives the gripping means is detected by the load detecting means. The control unit controls the rotation drive unit based on the load detected by the load detection unit to stop the rotation drive. The load when the relative motion between the bonded object and the object to be bonded is given depends on the molten state of the bonded object and the object to be bonded. In the present invention, since the melting state can be indirectly confirmed only by detecting the load, the timing for stopping the relative motion without providing a detection means for directly detecting the melting state such as the temperature and the melting site. Can be determined, and the apparatus can be prevented from becoming complicated.

  Further, according to the present invention, for example, the supply means arranges the melting point lowering member between the joined object and the article to be joined, so that the operator can arrange the joining method of the present invention without arranging the melting point lowering member. The joining apparatus to be executed can be realized.

  Further, according to the present invention, for example, the control means includes posture detecting means for detecting an inclination with respect to the vertical direction, and the control means applies in advance the force applied to the joint by gravity and the displacement driving means based on the detection result of the posture detecting means. The displacement driving means is controlled so as to have a predetermined force. Accordingly, the bonded object can be pressed against the object to be bonded regardless of the posture of the bonding apparatus with respect to the vertical direction, and the bonded object can be bonded to the object to be bonded with substantially the same bonding strength. .

In order to solve the above problems, a joining apparatus according to the present invention comprises a gripping means for gripping a joined article,
Rotation drive means for rotationally driving the gripping means in a state of gripping the joined product,
Displacement driving means for driving the gripping means in a state of gripping the joined article to press the joined article against the article to be joined,
Control means for controlling the driving of the rotation driving means and the displacement driving means;
Load detecting means for detecting a load applied to a rotation shaft of the rotation driving means when the rotation driving means rotates the gripping means; and
The control means is configured to stop the rotation of the joint by the rotation driving means based on the detection result of the load detection means.

  Preferably, a rotation stopping means for stopping the rotation of the joined article is further provided separately from the rotation driving means.

  Preferably, the apparatus further includes fixing means for relatively fixing the object to be bonded and the bonding apparatus.

  Preferably, the apparatus further includes supply means for supplying a melting point lowering substance between the bonded object and the bonded object.

  Preferably, the rotation stopping means includes at least one of a clutch for separating the rotation driving means and the gripping means and a brake for braking the gripping means.

  Preferably, the fixing means has a shape along the shape of the object to be joined, and / or a portion in contact with the object to be joined is formed of an elastic material.

  Preferably, the fixing means includes a high vacuum suction pad or a magnet.

  Preferably, the supply unit includes a sprayer that injects the melting point lowering substance in a mist form on at least one of the joining surfaces of the joined article and the article to be joined.

  Preferably, the supply means includes a clamp or a holder for fixing the thin plate-shaped melting point lowering substance to at least one of the joining surface and the joining object.

  Preferably, the rotation driving means includes an electric motor.

  Preferably, the displacement driving means includes an air cylinder.

  According to the joining apparatus according to the present invention, as compared with the conventional arc stud welding apparatus, since the melting region associated with joining is the minimum necessary, defects such as cracks and blowholes that occur with melting are less likely to occur. Moreover, it is an energy-saving device that does not require large electric power. In addition, since no arc is generated, there is no need for prior oxide film removal, and no harmful ultraviolet rays or fumes are generated. Moreover, there is little influence on the joint performance by the change in construction posture, and the dependence on the skill of the operator is small.

  In addition, compared to conventional friction welding equipment, the bonding interface is melted using a metal-metal chemical reaction, so the energy required for melting is low, and (i) the rotational speed is low compared to the friction welding method. (Ii) It is advantageous to reduce the pressing force, or (iii) reduce the rotational speed and reduce the pressing force. For this reason, even when the joined product has a small diameter, joining can be performed with a relatively low rotational speed and a relatively small pressing force. Further, the joining device can be reliably fixed to the object to be joined by a fixing means such as a suction pad without subjecting the object to be joined (work) to processing such as a bolt hole. In a state where the joining device is fixed to the object to be joined, joining can be performed in an arbitrary posture. Moreover, since the apparatus can be greatly reduced in size, it is possible to carry out the construction easily by carrying the joining apparatus to the existing structure. Moreover, it can be arbitrarily handled with only a simple auxiliary device.

It is a front view which shows the joining apparatus 1 of one Embodiment of this invention. It is the side view which looked at the joining apparatus 1 from the right side of FIG. It is sectional drawing which looked at the joining apparatus 1 from III-III of FIG. It is sectional drawing seen from the cut surface line IV-IV of FIG. FIG. 5 is a diagram showing a step of forming a melting point lowering member 54 on the surface of the stud 2. It is a figure which shows the process of fixing melting | fusing point lowering member 54 to a predetermined position with the fixing tool 55A. It is a flowchart which shows the joining process of the control means 8 when joining the stud 2 and the workpiece | work 3. FIG. It is a figure which shows typically the joining process which joins the stud 2 and the workpiece | work 3. FIG. It is a figure which shows typically the time change of the electric current which flows into the servomotor. It is a figure showing the tensile strength of the joined body which joined the 1st-4th studs 61-64 to the aluminum substrate, respectively. It is a figure showing each tensile strength of the joined object which changed the pressing force at the time of upset pressurization with the 4th stud 64, and joined to the aluminum substrate. FIG. 4 is a cross-sectional view of a joined body in which a fourth stud 64 is joined to a work 3. The upper row is the result of observing the state of the fourth stud 64 side with a scanning electron microscope (SEM) on the fracture surface of the workpiece 3 and the fourth stud 64, and a melting point lowering member (Zn) is used as a comparative example. The observation results in the case of joining without performing are shown below. It is the figure which expanded further the enlarged drawing 2 of the upper stage (Example) of FIG. 11A. It is the figure which expanded further FIG. 11A lower stage (comparative example) enlarged drawing 2. FIG. It is a top view of the joined body which joined the 4th stud 64 after performing a bending test to work 3. FIG. It is a figure which shows the influence on the joint tensile strength by the change of a construction posture.

  The joining apparatus 1 as one embodiment of the present invention and a joining method using the apparatus will be described below.

  In the present embodiment, the direction perpendicular to the paper surface of FIG. 1 is defined as the first direction X1, X2 (“X1, X2” is collectively described as X), and the left-right direction in FIG. 1 is defined as the second direction. Y1 and Y2 ("Y1, Y2" are collectively described as Y), and the vertical direction in FIG. 1 is defined as the third direction Z1, Z2 ("Z1, Z2" is collectively described as Z). Further, the third direction one Z1 may be referred to as an upper Z1, and the third direction other Z2 may be referred to as a lower Z2. The first to third directions X, Y, and Z are orthogonal to each other.

  As shown in FIGS. 1 to 4, the joining apparatus 1 joins a stud 2 corresponding to a joined object formed of a metal material to a workpiece 3 corresponding to an object to be joined formed of a metal material. Specifically, the stud 2 is pressed against the work 3 and the stud 2 is rotated to weld the stud 2 and the work 3 by frictional heat. The work 3 constitutes a part of an LNG tank that houses, for example, liquefied natural gas (abbreviated as LNG) and has a spherical shape. The joining device 1 joins the stud 2 so that the axis of the stud 2 is perpendicular to the outer surface of the spherical workpiece 3. The joining apparatus 1 includes a support base 4, a gripping means 5 that grips the stud 2 and extends in the third direction Z, a displacement driving means 6 that drives the gripping means 5 in the third direction Z, and a gripping means 5 that It includes a rotation drive means 7 that rotates around a reference axis L extending in three directions Z, and a displacement drive means 6 and a control means 8 that controls the drive of the rotation drive means 7, and the stud 2 using the joining method of the present invention. A joined body in which is bonded to the work 3 is manufactured.

  The rotation driving means 7 holds the gripping means 5 and rotationally drives the gripping means 5. The rotation driving means 7 is held by the displacement driving means 6. The displacement driving means 6 drives the rotation driving means 7 in the third direction Z. The displacement driving means 6 displaces and drives the rotation driving means 7 in the third direction Z, whereby the holding means 5 held by the rotation driving means 7 and the stud 2 held by the holding means 5 are moved in the third direction Z. It is displaced to. The displacement driving means 6 is connected to a support base 4 that is fixed to the work 3 by being attached thereto. In such a joining apparatus 1, the rotation driving means is in a state where the gripping means 5 holds the stud 2 and the displacement driving means 6 presses the stud 2 against the workpiece 3 by driving the rotation driving means 7 downward Z2. By rotating the gripping means 5 by 7, the stud 2 is pressed against the work 3, and a rotational motion can be generated to generate frictional heat at the contact portion.

  The support base 4 is affixed and fixed to the work 3 by a bolt member, an adhesive, a magnet, vacuum suction, or the like, and in this embodiment, is attached to the work 3 by vacuum suction. The support 4 has a fixing means including a high vacuum suction pad 4a made of an elastic member and an exhaust pipe 4b, and the suction pad 4a is sucked and fixed to the work 3 by exhausting by a separately provided exhaust means. The exhaust means is realized by an ejector, a vacuum pump or the like. Due to the elasticity of the suction pad 4a, the joining device 1 can be reliably fixed to the work 3 even when the surface 3a of the work 3 is not flat or smooth. In the present embodiment, the evacuation means is realized by a vacuum pump, and the direction in which the normal line on the reference axis L of the surface 3a of the workpiece 3 extends coincides with the third direction Z.

  The displacement driving means 6 is realized by an electric motor, a hydraulic device, a pneumatic device or the like, and is realized by a pneumatic device in the present embodiment. The displacement driving means 6 includes two double-action air cylinders 15a and 15b. The rods 16a and 16b of the double-acting air cylinders 15a and 15b extend downward from the cylinder tubes 17a and 17b to the lower Z2, respectively, and the ends of the lower Z2 are connected to the support 4 respectively. The displacement driving means 6 further includes a first guide portion 18 provided to be sandwiched between the two cylinder tubes 17a and 17b and guided through the gripping means 5 in the third direction Z. A through hole penetrating in the third direction Z is formed in the first guide portion 18, and the gripping means 5 is guided in the third direction Z through the through hole. The displacement driving means 6 further includes a compressed air supply source, an electromagnetic switching valve, and a flow path through which the compressed air is passed.

  The rotation driving means 7 is realized by an electric motor, and is realized by a servo motor 23 in the present embodiment. The servo motor 23 includes a drive output shaft 24 having an axis common to the reference axis L. The rotation driving means 7 further includes a connecting shaft 25 connected to the drive output shaft 24, and a clutch 26 that connects the upper Z1 end of the shaft 21 of the gripping means 5 to the connecting shaft 25. The clutch 26 is realized by a dry single-plate electromagnetic clutch in the present embodiment. The clutch 26 switches between connecting and disconnecting the connecting shaft 25 and the gripping means 5 according to the current flowing in the coil, and the rotational power of the servo motor 23 is gripped by the drive output shaft 24 and the connecting shaft 25. 5 is switched. The joining apparatus 1 further includes a brake 34 that applies a force in a direction opposite to the rotation direction of the gripping means 5. In the present embodiment, the brake 34 is realized by a dry single plate electromagnetic brake. The brake 34 is fixed to the end of the lower Z2 of the first guide portion 18 by a bolt member 35, and the gripping means 5 passes through the center.

  As a modified example, by using a motor with a brake function, the electromagnetic clutch and the electromagnetic brake are not required, and the apparatus can be downsized.

  The rotation driving means 7 further includes a second guide portion 28 fixed to the upper Z1 of the displacement driving means 6 with a plurality of bolt members 27. The second guide portion 28 is formed with a through hole 31 penetrating in the third direction Z around the reference axis L, and the end portion of the upper Z1 of the gripping means 5 and the connecting shaft 25 are guided to the through hole 31. And is supported rotatably around the reference axis L.

  The joining apparatus 1 further includes a melt state grasping means 43 for grasping the melt state of the interface of the joining objects being joined. The molten state grasping means 43 includes a load detecting means for detecting a load when the rotation driving means 7 rotationally drives the gripping means 5, a thermometer for measuring the temperature in the vicinity of the interface between the stud 2 being joined and the workpiece 3, and This is realized by a deformation amount detecting means for measuring the deformation amount of the stud 2 and the workpiece 3 being joined. The deformation amount detection means calculates the deformation amount based on, for example, the displacement amount of the gripping means that grips the stud 2. The melt state grasping means 43 in the present embodiment is realized by a galvanometer that detects a current flowing through the rotation drive means 7 as a load detection means, and is provided in the rotation drive means 7 so that a part of the rotation drive means 7 is provided. Constitute. The molten state grasping means 43 detects the current flowing through the rotation driving means 7 and gives information representing the detected current to the control means 8. Information given from the molten state grasping means 43 to the control means 8 is information representing the current flowing through the servo motor 23 that realizes the rotation driving means 7 and corresponds to the magnitude of torque when the grasping means 5 is rotated. Information, that is, a load when the rotation driving means 7 drives the gripping means 5 to rotate.

  The joining apparatus 1 further includes posture detection means 44 that detects an inclination with respect to the vertical direction and detects its own posture. The posture detection means 44 is attached to the second guide portion 28 from the other side Y2 in the second direction. The posture detection means 44 includes a disc-shaped protractor 45, an instruction unit 46 that indicates an angle, and a central shaft 47 that rotatably supports the instruction unit 46.

  The joining apparatus 1 further includes an annular suspension ring 48. The suspension ring 48 is attached to one side X1 of the second guide portion 28 in the first direction. The suspension ring 48 is disposed on a straight line that passes through the center of gravity of the joining device 1 and extends in parallel with the first direction X, for example. Thus, when the suspension ring 48 is supported, the reference axis L is parallel to the horizontal direction.

  The joining device 1 further includes an annular suspension ring 48 and one or a plurality of handles, and in the present embodiment, includes two first handles 51 and a second handle 52. The operator can support the joining device 1 so as to be displaceable by gripping the first handle 51 and the second handle 52.

  The control unit 8 controls the driving of the displacement driving unit 6 and the rotation driving unit 7. The control means 8 is realized by, for example, a microcomputer and a PLC (Programmable Logic Controller). The control means 8 controls the drive of the displacement drive means 6 and the rotation drive means 7 according to a control program stored in advance. The joining apparatus 1 further includes input means including a numeric keypad. When the operator operates the input unit, a command corresponding to this operation is given to the control unit 8, and the control unit 8 performs control based on the given command. For example, the control program is changed according to the operation of the input means. Thus, the operator operates the input means to change the control program, so that the rotation speed when the rotation driving means 7 is driven to rotate, and the driving in the third direction Z when the displacement driving means 6 is driven to displace. You can set the force.

  The control means 8 controls the displacement driving means 6 so that the stud 2 presses the workpiece 3 with a predetermined force. The force by which the stud 2 presses the workpiece 3 includes the force applied in the third direction Z by the displacement driving means 6 and the members supported by the two cylinder tubes 17a and 17b and the displacement driving means 6 (gripping means 5, rotational drive). The resultant force with the component in the third direction Z of gravity applied to the means 7, the posture detecting means 44, the suspension ring 48, the first handle 51 and the second handle 52). The control means 8 in this embodiment is configured so that the resultant force of the force applied to the stud 2 by the weight of the joining device 1 and the force applied to the stud 2 by the displacement driving means 6 becomes a predetermined force. Control the compressed air supply. In the present embodiment, the total mass of the members supported by the two cylinder tubes 17a and 17b and the displacement driving means 6 is M, and the gravitational acceleration is g. The force applied to the stud 2 by the weight of the joining device 1 is a value obtained by integrating the cosine of the angle formed by the third direction Z and the vertical direction, M, and g. For example, when the joining device 1 is arranged so that one surface in the thickness direction of the protractor 45 is parallel to the vertical direction, the force applied to the stud 2 by the weight of the joining device 1 is the cosine of the angle indicated by the indicating unit 46. , M and g are integrated values. The joining apparatus 1 in the present embodiment will be described on the assumption that the joining apparatus 1 is used in a state where one surface in the thickness direction of the protractor 45 is parallel to the vertical direction.

  The operator reads the angle indicated by the instruction section 46 and gives the read angle to the control means 8 by operating the input means. Note that the angle indicated by the instruction unit 46 may be given from the posture detection unit 44 to the control unit 8 without an operator. The control means 8 is a displacement drive means so that the sum of the force applied in the third direction Z by the displacement drive means 6 and the integrated value of the cosine and M and g of the input angle becomes a predetermined force. 6 Compressed air supply source is controlled. Accordingly, the stud 2 can be pressed against the workpiece 3 regardless of the posture of the joining device 1 with respect to the vertical direction. This predetermined force can be set by the operator operating the input means.

  FIG. 5 is a diagram illustrating a process of forming the melting point lowering member 54 on the surface of the stud 2. The stud 2 includes a columnar shaft portion 2a, a columnar columnar portion 2b protruding in the circumferential direction from an end portion in the axial direction of the shaft portion 2a, and a tip portion 2c extending from the columnar portion 2b in a tapered shape. . The melting point lowering member 54 in the present embodiment is formed by being laminated on the side surface of the conical tip portion 2c. In the present embodiment, for example, by spraying the mist-like melting point lowering member 54a having a Zn content of 95% from the spraying device 55 disposed on the support base 4 toward the tip 2c, the melting point lowering member 54 is Laminated on the surface of the stud 2.

  The melting point lowering member 54 is disposed between the stud 2 and the work 3 when the stud 2 and the work 3 are joined. In the present embodiment, the melting point lowering member 54 is arranged between the stud 2 and the work 3 by arranging the melting point lowering member 54 on the surface of the stud 2. The melting point lowering member 54 may be formed by being laminated on the surface. In still another embodiment, the thin plate is placed between the stud 2 and the work 3 without being laminated on the surface of the stud 2 and the work 3. The melting point lowering member 54 may be arranged so that the stud 2 and the workpiece 3 sandwich the melting point lowering member 54 (see FIG. 5A).

  The melting point lowering member 54 generates a liquid phase at a temperature lower than the melting point of the metal material forming the stud 2 and the work 3 by the eutectic reaction with the metal material forming the stud 2 and the work 3. It melts with the metal material to be formed. The stud 2 and the workpiece 3 in the present embodiment are made of the same type of metal material and are made of aluminum. For example, JIS standard A5356, A5052, or A5056 can be used for the stud 2, and JIS standard A5083 can be used for the work 3. The melting point lowering member 54 is made of a metal material such as Zn, Cu, Si, and Mg that generates a liquid phase at a temperature lower than the melting point of aluminum by eutectic reaction with aluminum. In this embodiment, the melting point lowering member 54 is made of Zn.

  Next, with reference to FIG. 6 thru | or FIG. 8, the method of joining the stud 2 and the workpiece | work 3 using the joining apparatus 1 is demonstrated.

  When the melting point lowering member 54 is disposed between the stud 2 and the work 3, the control means 8 controls the rotation driving means 7 to rotate the gripping means 5 in that state, and the gripping means 5 causes the stud 2 to move. The displacement driving means 6 is controlled so as to be pressed against the work 3, and frictional heat is generated, which is less than the melting point of at least one of the melting point of the metal material forming the stud 2 and the melting point of the metal material forming the work 3. The liquid phase by the eutectic reaction is generated in the connection portion 56 between the stud 2 and the work 3 and the melting point lowering member 54 at the temperature of 5 to control the rotation driving means 7 to stop the rotation driving and perform the upset pressurization. The stud 2 is joined to the work 3. Note that the upset pressurization is not necessarily an essential process, and is appropriately performed according to the joining conditions.

  With the stud 2 attached to the gripping means 5, the joining device 1 is fixed to the work 3, and the operator operates the input means to give a command to start joining the stud 2 and the work 3 to the control means 8. , The process proceeds from step s0 to step s1.

  In step s1, the control unit 8 controls the rotation driving unit 7 to start the rotation driving of the gripping unit 5. In the present embodiment, for example, the gripping means 5 is rotated around the reference axis L at 6000 rpm. Next, in step s2, the control means 8 controls the displacement drive means 6 to start the displacement drive to the lower Z2. As a result, as shown in FIG. 7A, the stud 2 gripped by the gripping means 5 descends downward Z2 while rotating around the reference axis L. When the stud 2 rotates around the reference axis L and is pressed against the work 3, frictional heat is generated, and the tip of the stud 2 and the part of the work 3 attached to the stud 2 are melted.

  Next, in step s3, the control means 8 determines whether or not the load when the rotation driving means 7 rotationally drives the gripping means 5 is greater than or equal to a predetermined load. If it is greater than or equal to the predetermined load, the control means 8 proceeds to step s4. If it is less than the predetermined load, the process of step s3 is repeated.

  The current flowing through the servomotor 23 when the gripping means 5 is rotated at a constant rotational speed changes according to the melting state of the stud 2 and the workpiece 3. When the current flowing through the servomotor 23 reaches a preset joining end current, it is determined that the load is equal to or greater than a predetermined load, and the process proceeds to step s4. The preset joining end current is experimentally set so that the joining strength becomes the highest when the joining is finished.

  Next, in step s4, the control means 8 controls the clutch 26 and the brake 34 of the rotation drive means 7 to suddenly stop the rotation drive. Thereby, a to-be-joined object and a to-be-joined object are joined. In FIG. 8, the current flowing through the servomotor 23 when the rotation drive of the rotation drive means 7 is not stopped is indicated by a broken line.

  Next, in step s5, the control means 8 controls the displacement driving means 6 to start the displacement driving to the upper Z1, displace the gripping means 5 to the upper Z1, and release the stud 2 from the gripping means 5. Next, it transfers to step s6 and a joining process is complete | finished.

  As an optional step to be performed after step s4, the control means 8 controls the displacement driving means 6 so that the force applied to the lower Z2 to the gripping means 5 for about 1 to 3 seconds from the stop of rotation driving is 5% to 150%. %, And an upset pressure may be applied to the stud 2. Thus, by performing upset pressurization for about 1 to 3 seconds after stopping the rotation drive, the eutectic liquid phase at the bonding interface is discharged, and the active new surfaces of the bonded object and the bonded object are brought into contact with each other. The stud 2 is joined to the work 3.

  According to the joining device 1 of the present embodiment described above, the stud 2 and the workpiece 3 are pressed while pressing the stud 2 against the workpiece 3 with the melting point lowering member 54 interposed between the stud 2 and the workpiece 3. Give relative motion between. As a result, the connecting portion 56 of the stud 2 and the workpiece 3 is melted by the eutectic reaction at a temperature lower than the melting point of the stud 2 and the workpiece 3. After the stud 2 and the work 3 are melted, the relative movement is stopped, so that the stud 2 formed of the same kind of metal material can be joined to the work 3.

  In the present embodiment, since the region where friction occurs is locally heated and the melting range can be limited locally, when the molten pool formed like the arc stud method of the prior art solidifies. The occurrence of defects such as cracks and blow holes can be suppressed, and highly reliable bonding can be realized. Moreover, since the power supply for generating arc discharge and the apparatus which supplies shield gas etc. are not required like the arc stud method, the cost of the joining apparatus 1 for implement | achieving a joining method can be reduced significantly. Furthermore, compared with the arc stud method, since it can join without generating an arc discharge, it can join by energy saving. Furthermore, since harmful ultraviolet rays and fumes generated by arc discharge are not generated, the work environment can be prevented from deteriorating, and the joining work can be performed in a clean environment.

  Further, in the conventional friction welding method, a large pressing force is required to cause plastic deformation. However, in the present invention, the melting point of the metal material forming the stud 2 and the workpiece 3 is utilized by utilizing a eutectic reaction. Since the stud 2 and the work 3 can be melted at a temperature lower than the melting point of at least one of them, the joining can be realized with a smaller pressing force than the friction welding method, and a large pressing force is generated. Does not require large-scale equipment. Furthermore, compared with the friction welding method, (i) to reduce the rotational speed, (ii) to reduce the pressing force, or (iii) to reduce the rotational speed and reduce the pressing force. Since it is advantageous, even a small stud 2 to which the friction welding method cannot be applied can be joined to the workpiece 3. Furthermore, since the region where friction occurs can be locally heated and the melting range can be locally limited, the stud 2 is attached to the workpiece 3 even when the shape of the joint surface between the stud 2 and the workpiece 3 is different. Can be joined.

  Moreover, according to the joining apparatus 1 of this embodiment, since brazing is not performed, it is difficult to apply brazing, the melting temperature range is wide, and the difference in melting point from the brazing material is relatively small. Cu, Mg, Zn , High strength aluminum alloy having a high content of Si, etc. can be joined.

  Moreover, according to the joining apparatus 1 of this Embodiment, since the relative motion is given by rotating the stud 2, the region where the frictional heat is generated can be made as narrow as possible, and the region where the influence of the joining is possible is possible. It can be as narrow as possible. For example, compared with the case where the stud 2 is slid while being pressed against the workpiece 3 and reciprocates, the region where the frictional heat is generated can be narrowed. This makes it possible to make the region where the influence of the joining occurs as small as possible.

  Furthermore, according to the joining apparatus 1 of the present embodiment, the stud 2 has a cylindrical shape, and the tip portion 2c pressed against the work 3 is formed in a tapered shape. If the stud 2 has a completely cylindrical shape and the tip is formed in a flat surface, the relative speed is higher at the outer side and the outer side when the joint is rotated. Become. Friction heat is expressed as the product of pressure, relative speed, and friction time, so the outer side in the radial direction with a higher rotational speed is heated than the inner side with a lower rotational speed, and the temperature at the time of joining is higher. Variations occur and bonding reliability decreases. In the tapered stud 2, the tip is first heated and melted, and the region radially outward is sequentially pressed against the object to be welded and melted by frictional heat, so that all the parts to be melted can be melted. That is, the radially inward direction where the rotational speed is low is rubbed at a high pressure for a long time, and the radially outward direction where the rotational speed is high is rubbed at a low pressure for a short time. As a result, variations in temperature during bonding can be suppressed, and highly reliable bonding can be realized.

  Furthermore, the stud 2 in the present embodiment is formed such that the cylindrical portion 2b protrudes in the radial direction with respect to the shaft portion 2a. For example, as compared with the case where the cylindrical portion 2b is formed in a tapered shape from the tip of the shaft portion 2a without protruding in the radial direction with respect to the shaft portion 2a, the cylindrical portion 2b is formed in the radial direction with respect to the shaft portion 2a. By projecting and forming, when the stud 2 is joined to the workpiece 3, a cross section perpendicular to the axial direction at the joining portion is increased, and the joining strength is increased. The stud shape to which the present invention can be applied is not limited to this example.

  Furthermore, according to the joining apparatus 1 of the present embodiment, the molten state grasping means 43 detects the load of the rotation driving means 7 when a relative motion is given between the stud 2 and the work 3, and based on the detected load. The relative movement between the stud 2 and the workpiece 3 is stopped. The load when the relative motion is applied between the stud 2 and the work 3 depends on the molten state of the stud 2 and the work 3. In the present invention, since the melting state can be indirectly confirmed only by detecting the load, the timing for stopping the relative motion without providing a detection means for directly detecting the melting state such as the temperature and the melting site. Can be determined, and the apparatus can be prevented from becoming complicated.

  Furthermore, according to the joining apparatus 1 of the present embodiment, the control means 8 is the sum of the force applied in the third direction Z by the displacement driving means 6 and the integrated value of the cosine of the input angle, M and g. However, the compressed air supply source of the displacement driving means 6 is controlled so as to have a predetermined force. Accordingly, the stud 2 can be pressed against the workpiece 3 regardless of the posture of the joining device 1 with respect to the vertical direction. For example, when the stud 2 is joined to the spherical workpiece 3 constituting a part of the LNG tank, the stud 2 is pressed against the workpiece 3 upward in the vertical direction, or the stud 2 is pressed against the workpiece 3 in the horizontal direction. To do. Even in such a case, the stud 2 can be pressed against the work 3 with a predetermined force regardless of the posture of the joining device 1 with respect to the vertical direction. Instead, the stud 2 can be joined to the workpiece 3 with substantially the same joining strength.

  In the joining device 1 of the present embodiment, a spray device 55 is disposed on the support 4 as a supply means for supplying the melting point lowering member 54 between the stud 2 and the workpiece 3. Alternatively, the mist-like melting point lowering member 54 a is ejected toward the work 3. In addition to the spraying device 55, as shown in FIG. 5A, the supply means may be constituted by a fixture 55A composed of a clamp or a holder for fixing the thin plate-shaped melting point reducing member 54 between the stud 2 and the workpiece 3. good. Accordingly, it is possible to realize the joining apparatus 1 that executes the joining method of the present invention without disposing the melting point lowering member 54 by the operator.

  The tip 2c of the stud 2 in the present embodiment has a conical shape, but may have a tapered shape. For example, a shape in which a side surface protrudes from a conical shape such as a hemisphere, or a side surface with respect to a conical shape. The shape may be retracted inward. Further, although the stud 2 is assumed to have a substantially cylindrical shape, the stud 2 may have a polygonal prism shape such as a triangular prism and a pentagonal prism.

  Moreover, although the joining apparatus 1 of this Embodiment was made to rotate the stud 2 to the surroundings of the reference axis line L, it is not restricted to rotation, for example, performs a sliding motion in the state which pressed the front-end | tip of the stud 2 against the workpiece | work 3, and joined. Frictional heat may be generated by giving a relative motion between the object and the object to be joined.

  Further, although the joining apparatus 1 of the present embodiment includes one posture detecting means 44, it includes two posture detecting means in other embodiments, and no matter what posture the joining apparatus 1 is in. An angle formed by the vertical direction and the reference axis L may be detected. For example, a protractor whose one surface in the thickness direction is perpendicular to the first direction X, and a protractor whose one surface in the thickness direction is perpendicular to the second direction Y, based on each angle of each indicator provided in the two protractors, The angle formed between the vertical direction and the reference axis L may be detected. As a result, the force applied to the stud 2 by the weight of the joining device 1 is calculated by integrating the cosines, M, and g of the angle formed by the reference axis L and the vertical direction, regardless of the posture of the joining device 1. As described above, the displacement driving means 6 can be controlled so that the stud 2 presses the workpiece 3 with a predetermined force.

  In addition, although the joining apparatus 1 according to the present embodiment can be carried by the operator by gripping the first and second handles 51 and 52, the first and second handles 51 and 52, the suspension ring 48, and the like can be used. You may fix to the predetermined work position, without providing.

  Moreover, although the stud 2 and the workpiece | work 3 in this Embodiment are formed with aluminum of the same kind of metal material and the melting point lowering member 54 is formed with Zn, it is not limited to these. When the stud 2 and the work 3 are made of iron, the melting point lowering member 54 may be made of Mn and Si. The stud 2 and the work 3 may be formed of different metal materials. For example, one of the stud 2 and the work 3 is formed of iron, the other is formed of aluminum, and the melting point lowering member 54 is formed of Si. May be.

[Example]
As an example, the four first to fourth studs 61 to 64 shown in FIG. 9 were joined to the workpiece 3 under the same conditions using the joining device 1 of the above-described embodiment. Moreover, the 4th stud 64 was joined to the workpiece | work 3 on two conditions from which the pressing force at the time of an upset press differs.

  FIG. 9 is a diagram illustrating the tensile strengths of the first to fourth studs 61 to 64. In FIG. 9, each of the first to fourth studs 61 to 64 was subjected to a tensile test six times, and the average value of the tensile strength was represented by a bar graph. In addition, the maximum value and the minimum value of the tensile strength in each tensile test are marked with a symbol (♦), and the maximum value and the minimum value are connected with a solid line.

  The first stud 61 has a cylindrical shape with a diameter of 6 mm. The second and third studs 62 and 63 have the same shape, and cylindrical shaft portions 62a and 63a having a diameter of 6 mm, and distal end portions 62b and 63b extending in a conical shape from the distal ends of the shaft portions 62a and 63a. Have. The heights of the tip portions 62b and 63b are 2 mm. The fourth stud 64 is the same as the stud 2 of the above-described embodiment, and the diameter of the shaft portion 64a is 6 mm, the diameter of the cylindrical portion 64b is 8 mm, and the height of the cylindrical tip portion 64c is 2 mm. The first and second studs 61 and 62 are not formed with the melting point lowering member 54, and the melting point lowering member 54 is formed on the surfaces of the end portions of the third and fourth studs 63 and 64. That is, the first and second studs 61 and 62 were joined to the work 3 without using the joining method of the present invention, and the third and fourth studs 63 and 64 were joined to the work 3 using the joining method of the present invention. The work 3 is made of aluminum, and JIS standard A5083 was used. The first to fourth studs 61 to 64 are made of aluminum, and JIS standard A5356 is used. The melting point lowering member 54 was formed by spraying a spray having a Zn content of 95%. The force that presses the first to fourth studs 61 to 64 against the workpiece 3 was set to 1000 Newton (N) as the pressing force during friction and 1900 N as the pressing force during upset pressurization. The joining method of the first and second studs 61 and 62 is the same as the friction welding method of the prior art. However, when the friction welding method is applied to a cylindrical stud having a diameter of about 6 mm, the pressing force during friction is usually The pressing force at the time of upset pressurization is about 5500 N, while the pressing force is small.

  As shown in FIG. 9, the tensile strength increases in the order of the first, second, third and fourth studs 61, 62, 63 and 64. Thus, it was shown that the 3rd and 4th studs 63 and 64 joined using the joining method of the present invention have higher tensile strength than the first and second studs 61 and 62. Moreover, since the tensile strength of the 2nd stud 62 became larger than the 1st stud 61, it was shown that a tensile strength becomes large by making an edge part tapered. In addition, since the tensile strength of the third stud 63 is larger than that of the second stud 62, it is shown that the tensile strength is increased by arranging the melting point lowering member 54, that is, by using the joining method of the present invention. It was. Further, since the tensile strength of the fourth stud 64 is larger than that of the third stud 63, the diameters of the bottom sides of the tip portions 63b and 64c are large, and the tensile strength increases as the cross-sectional area of the joining region increases. Indicated.

  FIG. 10 is a diagram illustrating the respective tensile strengths when the fourth stud 64 is joined to the workpiece 3 under two conditions with different pressing forces during upset pressurization. In FIG. 10, the pressing force at the time of friction is 1000 N, the pressing force at the time of friction and upset pressurization is equal to 1000 N, and the case where 1900 N increased by 90% from the friction at the time of upset pressurization is loaded. Each was subjected to six tensile tests, and the average value of the tensile strength was represented by a bar graph. In addition, the maximum value and the minimum value of the tensile strength in each tensile test are marked with a symbol (♦), and the maximum value and the minimum value are connected with a solid line.

  As shown in FIG. 10, it can be seen that the tensile strength is greater when 1900N increased by 90% than when friction is applied during upset pressurization, compared to when the pressing force during upset is equal to that during friction. .

  FIG. 11 is a cross-sectional view of a joined body in which the fourth stud 64 is joined to the workpiece 3. As shown in FIG. 11, by using the joining method of the present invention, most of the tip 64c and part of the cylindrical part 64b of the fourth stud 64 and the surface part of the workpiece 3 are plastically flowed in the joining process. I understand that.

  In the upper part of FIG. 11A, the state on the fourth stud 64 side is observed with a scanning electron microscope (SEM) in the fracture surface of the joint surface between the workpiece 3 and the fourth stud 64. No solidified droplets were observed in the central area of the joint surface, but in the peripheral area of the joint surface (the portion indicated by X in FIG. 11), the solidified liquid droplets as shown in the SEM photograph at the top of FIG. 11A. Was observed (see FIG. 11B in which the enlarged view 2 is further enlarged). Therefore, it can be seen that the material is melted at the time of joining and discharged to the outer peripheral portion by plastic flow.

  The lower part of FIG. 11A shows an observation result when a melting point lowering member (Zn) is not used as a comparative example, and solidified droplets were not observed in this comparative example (see FIG. (See enlarged FIG. 11C).

  FIG. 12 is a plan view of a joined body obtained by joining the fourth stud 64 to the work 3 after performing a bending test. As shown in FIG. 12, when the fourth stud 64 is joined using the joining method of the present invention, even if the angle formed between the normal of the surface of the workpiece 3 and the fourth stud 64 is 90 ° or more by a bending test. It has been shown that the fourth stud 64 does not peel from the workpiece 3. For example, the standard MIL-S-24149B stipulates that the stud bends 15 ° or more without being peeled off in a bending test. When the joining method of the present invention is used, the standard defined in the standard MIL-S-24149B can be satisfied despite the pressing force smaller than the normal pressing force when applying the friction welding method of the prior art. confirmed.

  FIG. 13 is a diagram showing the influence on the joint tensile strength due to the change in the construction posture, and there is no significant change in the joint tensile strength between the case of joining in the vertically downward direction and the case of joining in the horizontal lateral direction. I understand.

  Although the preferred examples of the present invention have been described above in a specific manner, it is obvious that various modifications can be made. Accordingly, it is to be understood that the invention can be practiced otherwise than as specifically described herein without departing from the scope and spirit of the invention.

Claims (21)

Between each of the bonded object and the bonded object each formed of a metal material, the melting point lowering member of at least one of the bonded object and the bonded object is disposed,
Friction heat is generated by giving a relative motion between the bonded object and the bonded object in a state where the bonded object is pressed against the bonded object via the melting point lowering member, Melting at least one of the bonding object and the bonded object and the melting point reducing member at a temperature lower than the melting point of at least one of the bonded objects;
Relative motion between the said joining thing and the said to-be-joined object is stopped, and the said joining thing is joined to the said to-be-joined object, The joining method characterized by the above-mentioned.   The bonding method according to claim 1, wherein the bonded object and the bonded object are formed of the same type of metal material.   The joining method according to claim 2, wherein the metal material is aluminum.   The joining method according to any one of claims 1 to 3, wherein a relative motion is given between the joined article and the article to be joined by rotating the joined article.   The joining method according to claim 4, wherein the joined article has a cylindrical shape, and a tip portion pressed against the joined object is formed in a tapered shape. Detecting a load when a relative motion is given between the bonded object and the bonded object;
The joining method according to any one of claims 1 to 5, wherein the relative motion between the joined article and the article to be joined is stopped based on the detected load. A gripping means for gripping a joint formed of a metal material;
A rotation driving means for rotating the gripping means in a state of gripping the bonded article;
A displacement driving means for displacing and driving the gripping means in a state of gripping the bonded article;
Control means for controlling the drive of the rotation drive means and the displacement drive means,
The control means includes
The rotational driving means is controlled with a melting point lowering member of at least one of the bonded object and the bonded object disposed between the bonded object and the bonded object formed of the metal material. Then, while the gripping means is rotated, the displacement driving means is controlled so that the gripping means presses the joined object against the joined object to generate frictional heat between the two, and the joined article and the joined object. Melting at least one of the joined article and the article to be joined and the melting point lowering member at a temperature lower than the melting point of at least one of the articles, A joining apparatus characterized by controlling to stop rotational driving and joining the joined article to the article to be joined. Load detection means for detecting a load when the rotation driving means rotationally drives the gripping means;
The joining apparatus according to claim 7, wherein the control unit controls the rotation driving unit to stop the rotation driving based on the load detected by the load detection unit.   The joining apparatus according to claim 7, further comprising a supply unit that disposes the melting point lowering member between the joined article and the article to be joined. It further includes posture detecting means for detecting the inclination with respect to the vertical direction,
The control means controls the displacement driving means based on a detection result of the posture detection means so that a force applied to the joint by gravity and the displacement driving means becomes a predetermined force. The joining apparatus as described in any one of Claims 7-9. A gripping means for gripping the joined article;
A rotation driving means for rotating the gripping means in a state of gripping the bonded article;
Displacement driving means for driving the gripping means to displace and pressing the joined article against the article to be joined in a state where the joined article is grasped.
Control means for controlling the driving of the rotation driving means and the displacement driving means;
Load detecting means for detecting a load applied to a rotation shaft of the rotation driving means when the rotation driving means rotates the gripping means; and
The said control means is comprised so that rotation of the said joining thing by the said rotation drive means may be stopped based on the detection result of the said load detection means, The joining apparatus characterized by the above-mentioned.   The joining apparatus according to claim 11, further comprising: a rotation stopping unit that stops the rotation of the joined object separately from the rotation driving unit.   The bonding apparatus according to claim 11, further comprising a fixing unit that relatively fixes the object to be bonded and the bonding apparatus.   The joining apparatus according to claim 11, further comprising supply means for supplying a melting point lowering substance between the joined article and the article to be joined.   13. The joining apparatus according to claim 12, wherein the rotation stopping means includes at least one of a clutch for separating the rotation driving means and the gripping means and a brake for braking the gripping means.   The said fixing means is provided with the shape along the shape of the said to-be-joined object, and / or the part which contacts the said to-be-joined object is formed of the elastic material. Welding equipment.   14. The joining apparatus according to claim 13, wherein the fixing means includes a high vacuum suction pad or a magnet.   The said supply means contains the sprayer which injects the said melting | fusing point lowering substance in the shape of a mist with respect to the joining surface of at least any one of the said joining thing and the said to-be-joined thing. Joining device.   15. The joining apparatus according to claim 14, wherein the supply means includes a fixture for fixing the thin plate-shaped melting point lowering substance between the joined article and the article to be joined.   The joining apparatus according to claim 11, wherein the rotation driving unit includes an electric motor.   21. The joining apparatus according to claim 11, wherein the displacement driving means includes an air cylinder.

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