JP5440328B2 - Rivet joining method - Google Patents

Description

  The present invention relates to a rivet joining method, and is particularly suitable for use in joining a plurality of materials to be joined using a self-piercing rivet.

  Conventionally, a plurality of sheets using a self-piercing rivet having a head and a leg formed integrally with the head so that a hole coaxial with the head is formed from the head to the tip. Joining materials to be joined is performed. In such joining, a die having a recess corresponding to the shape and size of the leg portion of the self-piercing rivet is prepared. Then, the self-piercing rivet and the die are arranged so that the leg portion of the self-piercing rivet and the concave portion of the die are opposed to each other through the plurality of overlapped materials to be joined. In this state, the head of the self-piercing rivet is pressed with a punch from above, and the self-piercing rivet is driven into the material to be joined.

  By doing so, the leg portion of the self-piercing rivet penetrates the upper material to be joined although the lowermost material to be joined does not penetrate. At this time, the leg portion of the self-piercing rivet and the material to be joined undergo plastic deformation under the pressure restraint force generated when the self-piercing rivet is driven. In particular, the material to be joined at the lowermost portion is plastically deformed to such an extent that the shape of the concave portion of the die is substantially transferred by the pressure restraining force. For this reason, radial or annular cracks may occur in the rivet joint of the lowermost material to be joined, and the rivet joint may have a non-uniform shape. If it does so, in addition to the beauty | look of a rivet junction part being impaired, there exists a problem that the intensity | strength in a rivet junction part will fall. The occurrence of such cracks in the rivet joint becomes prominent when a high-tensile steel plate is used.

Therefore, Patent Document 1 discloses that the rivet driving point of the material to be bonded or the vicinity thereof is heated and then the self-piercing rivet is driven into the material to be bonded.
Patent Document 2 discloses that the die is rotated before and after the completion of the driving of the self-piercing rivet, and the crack is repaired by frictional heat accompanying the rotation.

JP 2006-7266 A JP 2006-43769 A

However, in patent document 1 mentioned above, you have to set different temperature with a to-be-joined material. In addition, if the overlapped materials to be joined are not completely adhered, heating by heat conduction may not be stable, and the ductility of the rivet joint may not be improved. If it does so, a crack will generate | occur | produce in a to-be-joined material at the time of rivet driving | operation, and there exists a possibility that the appearance and intensity | strength in the rivet joining part of a to-be-joined material may fall.
Moreover, in patent document 2 mentioned above, you have to generate | occur | produce the frictional heat of different temperature with a to-be-joined material. Further, there is a risk that the mechanical characteristics of the materials to be joined joined by the self-piercing rivet may be lowered due to a temperature rise accompanying heat generation. If it does so, there exists a possibility that the appearance and intensity | strength in the rivet junction part of a to-be-joined material may fall.
This invention is made | formed in view of the above problems, and makes it the 1st objective to improve the beauty | look of the junction part when joining a to-be-joined material using a self-piercing rivet. The second object is to stabilize the strength.

A rivet joining method according to the present invention is a rivet joining method for joining a plurality of stacked materials to be joined using a self-piercing rivet, wherein a recess corresponding to the shape and size of a leg portion of the self-piercing rivet is provided. An arrangement step of disposing the self-piercing rivet so that the concave portion of the die having the tip of the leg of the self-piercing rivet faces each other via the plurality of materials to be joined; A supply step of supplying a dedicated lubricant for lubricating the die between the material to be joined, which is disposed at a position closest to the die, among the bonding materials, and the supply A step of driving the self-piercing rivets arranged in the arrangement step into the plurality of materials to be joined after the lubricant is supplied in the step. Among the plurality of materials to be bonded, at least the material to be bonded arranged at a position closest to the die is a bare steel plate, an aluminum alloy plate, a steel plate whose surface is plated, or a surface plating treatment is aluminum alloy plate having undergone, the lubricant, the resin film, a lubricating oil, or Ri solid lubricant der, the implantation process, among the plurality of members to be joined, closest to the self-piercing rivet The self-piercing rivet is driven into the plurality of materials to be joined in a state where no lubricant is supplied to the surface of the material to be joined arranged at a position where the self-piercing rivet is arranged. To do.

According to the present invention, a dedicated lubricant for lubricating the die is supplied between the die to be joined and the die arranged closest to the die, and then a plurality of self-piercing rivets are joined. I put it into the material. Accordingly, it is possible to more easily and surely prevent the shape trace of the self-piercing rivet from becoming symmetric. Therefore, the aesthetics of the rivet joint can be improved.
In addition, when a material to be bonded having a tensile tension of 440 [MPa] or more is used as the material to be bonded at least at the position closest to the die, the occurrence of cracks in the rivet bonded portion can be easily suppressed. And the strength of the rivet joint can be stabilized.

It is a figure which shows the 1st Embodiment of this invention and shows an example of a structure of a rivet joining apparatus. It is a figure which shows the 1st Embodiment of this invention and shows an example of a mode that a to-be-joined material is joined by the rivet joining apparatus. It is a figure which shows the 2nd Embodiment of this invention and shows an example of a structure of a rivet joining apparatus. It is a figure which shows the 2nd Embodiment of this invention and shows an example of a mode that a to-be-joined material is joined by the rivet joining apparatus. It is a figure which shows the 3rd Embodiment of this invention and shows an example of a structure of a rivet joining apparatus. It is a figure which shows the 3rd Embodiment of this invention and shows an example of a mode that a to-be-joined material is joined by the rivet joining apparatus. It is a figure which shows the 3rd Embodiment of this invention and shows an example of a mode that a to-be-joined material is joined by the rivet joining apparatus. It is a figure which shows embodiment of this invention and shows the result of Example 1. FIG. It is a figure which shows embodiment of this invention and shows the result of Example 2. FIG. It is a figure which shows embodiment of this invention and shows the result of Example 3. FIG.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of a configuration of a self-piercing rivet joining apparatus. In order to simplify the explanation, in each drawing, only the configuration necessary for the explanation is shown in a simplified manner. In the following description, “self-piercing rivet” is abbreviated as “rivet” as necessary.

In FIG. 1, a rivet joining apparatus 1 includes a C-shaped frame 2, a die 3, a pad 4, a punch 5, a stand 6, a pressurizing motor 7, a ball screw 8, a box 9, and a pump 10. , Pipes 11, 12 a, 12 b, a vibration applying device 13, and a control device 14.
The die 3 and the pad 4 are attached to the C-shaped frame 2 so as to face each other in the horizontal direction (the direction of the double arrow in FIG. 1). Specifically, the die 3 is attached to the upper surface of the lower end portion of the C-type frame 2, and the pad 4 is attached to the lower surface of the upper end portion of the C-type frame 2. A punch 5 is disposed inside the pad 4.

A stand 6 is attached to the upper surface of the upper end portion of the C-shaped frame 2. A ball screw 8 is disposed inside the stand 6. A box 9 is disposed on the upper surface of the stand 6, and a pressurizing motor 7 is disposed on the lower surface of the box 9.
The pressurizing motor 7 is a motor for moving the punch 5 up and down. The rotational force of the pressurizing motor 7 is transmitted to the screw shaft of the ball screw 8 through a transmission gear train (not shown) provided in the box 9, and the screw shaft rotates. In accordance with the rotation of the screw shaft, the nut member fitted to the screw shaft by the action of the screw moves up and down together with the punch 5.

The pump 10 is for supplying the lubricating oil 15 accommodated in the container 16 to the recess 3a of the die 3 (see FIG. 2A). The lubricating oil 15 is supplied to the concave portion 3a of the die 3 through the pipes 11, 12a, and 12b. As the lubricating oil, a mineral oil, a synthetic oil, or a mixed oil of a mineral oil and a synthetic oil can be used. The viscosity of the lubricating oil can be appropriately determined according to the size of the recess 3a of the die 3, the size and material of the rivet, the material of the materials to be joined 100a and 100b, and the like.
The vibration applying device 13 is for applying a minute vibration to the die 3 in the horizontal direction (the direction of a double arrow shown below the die 3 in FIG. 1). The vibration adding device 13 includes a vibrator 13a for generating such vibration and a horn 13b for transmitting the vibration generated by the vibrator 13a to the die 3. As the vibrator 13a, for example, a bolt-clamped Langevin type vibrator (BLT) using a piezoelectric ceramic element (for example, a PZT (lead zirconate titanate) element), or an externally-sealed sealed vibrator using a piezoelectric ceramic element. Alternatively, a magnetostrictive vibrator (for example, a ferrite magnetostrictive vibrator or a nickel magnetostrictive vibrator) can be used.

  Here, in the present embodiment, the amplitude is selected from the range of 5 [μm] to 30 [μm] and is selected from the range of 1 [kHz] to 25 [kHz]. It is preferable to apply a minute vibration having a different frequency to the die 3 in the horizontal direction. The reason why the amplitude of the minute vibration applied to the die 3 by the vibration applying device 13 is 5 [μm] or more is that when the amplitude is less than 5 [μm], the oil does not spread over the entire concave portion of the die 3 and the die 3 This is because there is a risk that the surface of the material to be bonded 100b that comes into contact with the die 3 may become extremely rough when oil is cut between the material and the material 100b to be bonded, and the rivets are used for bonding. The amplitude of the minute vibration given to the die 3 by the vibration applying device 13 is 30 [μm] or less because when the amplitude exceeds 30 [μm], the die 3 and the object to be in contact with the die 3 are caused by the minute vibration. This is because the frictional heat generated between the bonding material 100b is increased, and the bonded material 100b and the die 3 may adhere to each other when bonded with rivets. Further, the frequency of the minute vibration given to the die 3 by the vibration applying device 13 is set to 1 [kHz] or more. If the frequency is less than 1 [kHz], the oil spreads over the entire concave portion of the die 3. This is because oil shortage occurs between the die 3 and the material to be joined 100b, and the surface of the material to be joined 100b in contact with the die 3 may become rough when joined with a rivet. Moreover, the frequency of the minute vibration given to the die 3 by the vibration applying device 13 is set to 25 [kHz] or less because when the frequency exceeds 25 [kHz], the die 3 and the die 3 are caused by the minute vibration. This is because the frictional heat generated between the materials to be joined 100b is in contact with each other, and there is a possibility that the materials to be joined 100b and the die 3 adhere to each other when they are joined with rivets.

The control device 14 is a device that controls the rivet joining device 1 as a whole, and controls operations of the pressurizing motor 7, the pump 10, the vibration applying device 13, and the like according to a preset schedule. The control device 14 can be realized by using, for example, a computer having a CPU, ROM, RAM, HDD, and various interfaces.
FIG. 2 is a diagram illustrating an example of a state in which the materials to be bonded 100 a and 100 b are bonded by the rivet bonding apparatus 1. Specifically, FIG. 2A is a diagram illustrating an example of a state before the materials to be joined 100a and 100b are joined by the rivet joining apparatus 1, and FIG. It is a figure which shows an example of the mode after material 100a, 100b was joined.

In the present embodiment, as illustrated in FIG. 2, a case where two members to be bonded 100 a and 100 b that are superposed on each other are bonded will be described as an example. Of the materials to be bonded 100a and 100b, at least the material to be bonded 100b closest to the die 3 is a bare steel plate, an aluminum alloy plate, a steel plate having a surface plated, or an aluminum alloy having a surface plated. It is a board. Further, any of these can be employed as the material to be joined 100a. Further, the materials to be joined 100a and 100b may be the same type or different types. As the plating, zinc-based, aluminum-based, or tin-based plating can be used. In the rivet joining apparatus 1 of the present embodiment, it is desirable that the material 100 to be joined is a joining target. Specifically, in the rivet joining apparatus 1 of the present embodiment, it is preferable to use a material to be joined (for example, a steel plate) having a tensile tension of 440 [MPa] or more as a subject of joining. This is because the material to be joined having a tensile tension of less than 440 [MPa] is soft, so that the joining strength does not change greatly whether or not the lubricating oil 15 is used. However, even if it is a to-be-joined material which has a tensile tension of less than 440 [MPa], it can prevent that the beauty | look of a rivet joined part is impaired. In this case, the tensile tension of all the materials to be bonded 100a and 100b may be 440 [MPa] or more, but at least the tensile tension of the material to be bonded 100b closest to the die 3 is 440 [MPa] or more. If it is.
The number of materials to be joined 100 to be joined is not limited to “2” and may be 3 or more.

  First, the pump 10 sucks up a predetermined amount of the lubricating oil 15 accommodated in the container 16 and supplies it to the concave portion 3a of the die 3 through the pipes 11, 12a, 12b. When the lubricating oil 15 is supplied to the concave portion 3a in this way, the vibration applying device 13 applies a minute horizontal vibration to the die 3. Thereby, the die 3 vibrates in the horizontal direction. By this vibration, the lubricating oil 15 supplied to the concave portion 3a of the die 3 moves inside the concave portion 3a, and a thin film of the lubricating oil 15 can be formed over a wide range of the surface on which the concave portion 3a of the die 3 is formed. (See FIG. 2 (a)). At this time, it is desirable that the entire recess portion 3a of the die 3 is filled with the lubricating oil 15. If the die 3 is vibrated when the lubricating oil 15 is supplied to the concave portion 3a, the die 3 may be vibrated before the lubricating oil 15 is supplied to the concave portion 3a.

As described above, the lubricating oil 15 is supplied to the recess 3a of the die 3, and the rivet 21 is driven into the metal plates 100a and 100b while vibrating the die 3 in the horizontal direction.
The rivet 21 is a general self-piercing rivet and has a head portion 21a and a leg portion 21b. The head portion 21a has a disk shape, the leg portion 21b has a hollow cylindrical shape coaxial with the head portion 21a, and the head portion 21a and the leg portion 21b are integrally formed. The tip of the leg portion 21a has a tapered shape. Here, the recess 3 a of the die 3 has a shape and a size corresponding to the shape and size of the leg 21 b of the rivet 21.

The conveying apparatus (not shown) is to be bonded so that the bonding positions of the bonded materials 100a and 100b are located on the concave portion 3a of the die 3 and the lower bonded material 100b is in contact with the die 3. 100 a and 100 b are arranged on the die 3.
After that, when the rivet 21 is attached to the punch 5 so that the upper surface of the head 21a of the rivet 21 is positioned on the lower surface of the punch 5, the motor (not shown) lowers the pad 4 and the upper bonded material 100a. The pad 4 is pressed against the upper surface. Here, the die 3, the pad 4, the tip of the leg portion 21 b of the rivet 21 attached to the punch 5 and the central region in the surface direction of the concave portion 3 a of the die 3 are substantially opposed to each other in the vertical direction. And the punch 5 is positioned. By such an operation of the pad 4, the bonded materials 100 a and 100 b are pressed and restrained from above and below by the pad 4 and the die 3. Thus, the pad 4 has a role of pressing the materials to be joined 100a and 100b.

Thereafter, the pressurizing motor 7 rotates the screw shaft of the ball screw 8 with a predetermined torque to lower the punch 5, and from above the upper material to be bonded 100 a, the rivet 21 is moved to the materials to be bonded 100 a and 100 b. Type in. Then, the lower material to be bonded 100b receives a driving force from the rivet 21, and is plastically deformed together with the upper material to be bonded 100a so as to be in close contact with the concave portion 3a of the die 3. At this time, the rivet 21 is also crushed in a so-called bottom-out state with respect to the recess 3 a of the die 3. In this way, the rivet 21 penetrates only through the upper material to be bonded 100a and enters the middle of the lower material to be bonded 100b while entering the middle, and the upper surface of the head 21a of the rivet 21 and the upper material to be bonded 100a are entered. The entry of the rivet 21 ends when the upper surface is substantially flush (see FIG. 4B). In this way, the joining of the workpieces 100a and 100b by the rivet 21 is completed. 4B shows a state in which the lubricant 15 does not remain in the recess 3a of the die 3, the lubricant 15 may remain in the recess 3a of the die 3.
The control device 14 incorporates a computer program for repeatedly executing the above-described operation. By executing this computer program, an operation command is issued to each part of the rivet joining device 1.

As described above, in the present embodiment, the lubricating oil 15 is supplied to the concave portion 3a of the die 3, and the rivet 21 is driven into the workpieces 100a and 100b. Therefore, the lubricity of the surface of the recess 3 a of the die 3 can be improved, and the lower workpiece 100 b can follow the deformation of the rivet 21. Therefore, it is possible to more easily and reliably prevent the rivet shape traces from having symmetry in the rivet joint portion of the lower workpiece 100b. Thereby, the beauty | look of the rivet junction part at the time of joining the some to-be-joined material 100a, 100b using a self-piercing rivet can be improved.
In particular, when the material to be bonded 100b having a tensile tension of 440 [MPa] or more is used as the material to be bonded 100b closest to the die 3, it is easy for cracks to occur in the rivet bonded portion. And it can prevent reliably. Thereby, the intensity | strength of the rivet joining part at the time of joining the some to-be-joined material 100a, 100b using a self piercing rivet can be improved.
In the present embodiment, the rivet 21 is driven into the metal plates 100a and 100b while vibrating the die 3 in the horizontal direction. Therefore, when the rivet 21 is driven, the lubricating oil covers a wide range of the recess 3a of the die 3. 15 can be spread. Thereby, the lubricating oil 15 supplied to the recessed part 3a of the die | dye 3 can be decreased, for example.

[Modification 1]
In the present embodiment, the surface of the concave portion 3a of the die 3 is made smooth. However, the surface of the concave portion 31a of the die 3 may be dulled to form irregularities on the surface of the concave portion 31a of the die 3. In this case, the average depth which is an average value of 10 depths of the central portion of the opening with respect to the central portion of the concave opening formed in the concave portion 31a of the die 3 is 5 [μm] or more. , 20 [μm] or less (for example, 5 [μm]) is desirable. This is because if the average depth is less than 5 [μm], it is difficult to keep the lubricating oil 15 inside the opening. On the other hand, if the average depth exceeds 20 [μm], the shape of the upper end portion of the dulled portion is not stable in manufacturing, and it becomes difficult to keep the lubricating oil 15 inside the opening. is there.

  Further, an average diameter which is an average value of ten diameters of the surface of the concave opening formed in the concave portion 31a of the die 3 (or the diameter of the circle when the shape of the surface of the opening is a circle) is It is desirable to set it to 50 [μm] or more and 150 [μm] or less (for example, 100 [μm]). If this average diameter is less than 50 [μm], there is little intrusion due to the deflection of the joined portion into the opening, and the lubricating oil 15 retained inside the opening cannot be discharged appropriately. This is because the frictional resistance with the material 100b increases. Further, when the average diameter exceeds 150 [μm], the sag due to the deflection of the bonded portion into the inside of the opening becomes large, and a lot of lubricating oil 15 is discharged from the inside of the opening, and This is because the frictional resistance between the shoulder and the material to be joined 100b increases.

  Further, the interval between the concave openings formed in the concave portion 31a of the die 3 (the distance between the centers of (the front surface) of the concave openings) is 1.5 times to 3 times the average diameter described above. It is desirable to do. When the distance is less than 1.5 times the average diameter, the area of the area where the die 3 and the material to be bonded 100b are in direct contact with each other becomes small, and this area becomes a convex portion to cause friction between the material to be bonded 100b and the die 3. This is because the coefficient increases. Further, if this interval exceeds three times the average diameter, the lubricating oil 15 on the surface of the die 3 is reduced, and a sufficient lubricating effect cannot be obtained.

  The unevenness as described above can be formed by performing shot blast processing, electric discharge processing, etching processing, laser processing or the like on the concave portion 3 a of the die 3. Of these methods, etching is preferable because the most accurate uneven pattern can be formed. By doing so, the lubricating oil 15 supplied to the concave portion 3a of the die 3 can be retained in the concave portion 3a of the die 3, and, for example, the rivet 21 is driven and scattered from the concave portion 3a of the die 3. It can suppress more reliably. Here, the uneven pattern as described above can be obtained, for example, by processing an image measured using a digital microscope. When the surface of the workpieces 100a and 100b is lubricated, the surface of the recess 3a of the die 3 may be uneven and the lubricant 15 need not be supplied.

[Modification 2]
FIG. 3 is a view showing a modification of the configuration of the self-piercing rivet joining apparatus. In this embodiment, as shown in FIG. 1, the die 3 is vibrated in the horizontal direction. However, as shown in FIG. 3, vibration may be applied to the die 3 in the vertical direction (the direction of the double arrow shown below the die 3 in FIG. 3).
[Modification 3]
In the present embodiment, the lubricating oil 15 is supplied to the recess 3 a of the die 3. However, the lubricating oil may be applied not to the recess 3 a of the die 3 but to the region of the lower material to be bonded 100 b facing the recess 3 a of the die 3.

[Modification 4]
In the present embodiment, the vibration applying device 13 applies a minute vibration to the die 3. However, it is not always necessary to use the vibration adding device 13. When the vibration applying device 13 is not used, for example, the pump 10 supplies the lubricating oil 15 to the concave portion 3a of the die 3 by a predetermined amount at a predetermined pressure so that the lubricating oil 15 is filled in the concave portion 3a of the die 3. Thereafter, if the lubricating oil 15 is pulled back by a predetermined amount at a predetermined pressure and returned to the container 16, the lubricating oil 15 can be supplied over a wide range of the surface of the die 3 where the concave portion 3a is formed. However, it is not always necessary to supply the lubricating oil 15 in this way.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the first embodiment, the case where the lubricating oil is used as the dedicated lubricant supplied between the materials to be bonded 100 a and 100 b and the die 3 has been described as an example. On the other hand, in this embodiment, the case where a resin film is used as the lubricant will be described as an example. Therefore, in the description of the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals as those in FIGS.
FIG. 4 is a diagram illustrating an example of the configuration of the rivet joining apparatus.
In FIG. 4, a rivet joining device 41 includes a C-shaped frame 2, a die 46, a pad 4, a punch 5, a stand 6, a pressurizing motor 7, a ball screw 8, a box 9, and a feeding device. 42, rolls 43a and 43b, a drive device 44, and a control device 45.

The feeding device 42 is for feeding the resin film 47 in order to supply the resin film 47 to the upper surface of the die 46. The rolls 43 a and 43 b define the conveyance path of the resin film 47. In FIG. 4, only representative rolls 43a and 43b are shown, but there may be other rolls. The drive device 44 is for rotating the rolls 43a and 43b. In the example shown in FIG. 4, by rotating the rolls 43a and 43b counterclockwise toward the paper surface, the resin film 47 is directed from right to left toward the paper surface (the arrow indicated by the resin film 47). In the example shown, the direction is sent out in the direction).
The control device 45 is a device that controls the rivet joining device 41 as a whole, and controls the operations of the feeding device 42, the drive device 44, and the like according to a preset schedule. The control device 45 can be realized by using, for example, a computer having a CPU, ROM, RAM, HDD, and various interfaces.

  FIG. 5 is a diagram illustrating an example of a state in which the materials to be joined 100 a and 100 b are joined by the rivet joining device 41. Specifically, FIG. 5A is a diagram illustrating an example of a state before the materials to be joined 100a and 100b are joined by the rivet joining device 41, and FIG. It is a figure which shows an example of the mode after material 100a, 100b was joined. In the present embodiment, similarly to the first embodiment, a case where two bonded materials 100a and 100b that are superposed on each other are bonded will be described as an example.

First, the driving device 44 drives the rollers 43a and 43b to rotate. Then, the resin film 47 is sent out from the feeding device 42. When the rollers 43a and 43b are rotated so that the resin film 47 moves by a predetermined distance, the driving device 44 stops the rotational driving of the rollers 43a and 43b. As a result, the resin film 47 is positioned on the upper surface of the die 46 (at least the entire upper portion of the recess 46a of the die 46).
Here, as the resin film, for example, “polytetrafluoroethylene, polyethylene, or nylon” having a thickness of 10 [μm] or more and 100 [μm] or less can be used. The reason why the thickness of the resin film 47 is 10 [μm] or more is that if the thickness of the resin film 47 is less than 10 [μm], the resin film 47 may be cut too thin. On the other hand, the thickness of the resin film 37 is set to 100 [μm] or less because if the thickness of the resin film 47 exceeds 100 [μm], the resin film 47 is too thick and the processing accuracy of the rivet joint may be lowered. Because there is.

After placing the resin film 47 on the upper surface of the die 46 as described above, an operation of driving the rivet 21 into the metal plates 100a and 100b is performed. Since the operation of driving the rivet 21 into the workpieces 100a and 100b is the same as that in the first embodiment, a detailed description thereof is omitted here.
Then, each time the driving operation of the rivet 21 is performed, the driving device 44 drives the rollers 43a and 43b so that the resin film 47 moves by a predetermined distance. However, it is not always necessary to move the resin film 47 every time the rivet 21 is driven once. For example, every time the rivet 41 is driven two or more times, the resin film 47 is moved. May be moved.

The control device 45 incorporates a computer program for repeatedly executing the above-described operation. By executing this computer program, an operation command is issued to each part of the rivet joining device 41.
As described above, even when the resin film 47 is disposed on the upper surface of the die 46 and the rivet 21 is driven into the workpieces 100a and 100b, the same effects as those of the first embodiment described above can be obtained. it can.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the present embodiment, a case where a solid lubricant is used as the lubricant will be described as an example. Also in the description of the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals as those in FIGS. 1 and 2, and detailed description thereof is omitted.
FIG. 6 is a diagram illustrating an example of the configuration of the rivet joining apparatus.
In FIG. 6, the rivet joining device 61 includes a C-shaped frame 2, a die 46, a pad 4, a punch 5, a stand 6, a pressurizing motor 7, a ball screw 8, a box 9, and a spray device 62. And a driving device 63.

The spray device 62 contains a solid lubricant, and sprays the solid lubricant over the entire surface of the die 46 where the recess 46a is formed.
The control device 63 is a device that controls the rivet joining device 61 as a whole, and controls the operation of the spray device 62 and the like according to a preset schedule. The control device 63 can be realized by using, for example, a computer having a CPU, ROM, RAM, HDD, and various interfaces.

  FIG. 7 is a diagram showing an example of a state in which the materials to be joined 100 a and 100 b are joined by the rivet joining device 61. Specifically, FIG. 6A is a diagram showing a state in which the solid lubricant 71 is sprayed on the surface of the die 46 where the recess 46a is formed. FIG. FIG. 6C is a diagram showing an example of a state after the materials to be joined 100a and 100b are joined by the rivet joining device 61. FIG. In the present embodiment, similarly to the first embodiment, a case where two bonded materials 100a and 100b that are superposed on each other are bonded will be described as an example.

First, the spray device 62 sprays the solid lubricant 71 onto the concave portion 46a of the die 46 (preferably the entire surface on which the concave portion 46a is formed) in a state where the materials to be bonded 100a and 100b are not placed on the die 56. Then, the solid lubricant 71 is sprayed to the concave portion 46a of the die 46 by a predetermined amount (see FIG. 7A). Thereafter, the spray device 42 retreats to a predetermined position that does not interfere with the driving operation of the rivet 21.
Here, as the solid lubricant 71, for example, molybdenum disulfide, graphite, tungsten disulfide, boron nitride, or wheat flour can be used.

After the solid lubricant 71 is sprayed on the concave portion 46a of the die 46 as described above, the conveyance device (not shown) causes the joining target positions of the materials to be joined 100a and 100b to be positioned on the concave portion 46a of the die 46. In addition, the materials 100a and 100b to be joined are disposed on the die 46 (see FIG. 7B). Note that in FIG. 7B, the solid lubricant 71 is provided only in the recess 46a of the die 46 for convenience of description. Is shown). Then, the rivet 21 is driven into the metal plates 100a and 100b. Since the operation of driving the rivet 21 into the metal plates 100a and 100b is the same as that in the first embodiment, a detailed description thereof is omitted here.
Thereafter, the unillustrated transfer device moves the materials to be bonded 100 a and 100 b from the top of the recess 46 a of the die 46. Then, as described above, the solid lubricant 71 is sprayed onto the recess 46 a of the die 46 by the spray device 62. However, it is not always necessary to spray the solid lubricant 71 every time the rivet 21 is driven once. For example, each time the rivet 21 is driven two or more times, the solid lubricant 71 is not sprayed. 71 may be sprayed.

The control device 63 incorporates a computer program for repeatedly executing the above-described operation. By executing this computer program, an operation command is issued to each part of the rivet joining device 61.
As described above, even when the solid lubricant 71 is sprayed on the recess 46a of the die 46 and the rivet 21 is driven into the metal plates 100a and 100b, the same effect as that of the first embodiment described above can be obtained. Can do.
Here, by using a dispenser as the spray device 62, the lubricating oil 15 described in the first embodiment can be sprayed onto the concave portion 46a of the die 46 using the rivet joining device 61 of the present embodiment.

Next, examples of the embodiment of the present invention will be described.
Example 1
FIG. 8 is a diagram showing the results of Example 1. Example 1 is an example of the first embodiment.
The joining conditions in this example are as follows.
-Material to be joined: Cold-rolled steel sheet (thickness = 1.6 [mm], 2 layers)
・ Rivets: Steel rivets (diameter = 5.0 [mm], neck length = 6.0 [mm])
・ Oscillator; Bolt-clamped Langevin type vibrator ・ Method of adding vibration to die; Transmit vibration of vibrator to die by horn ・ Direction of vibration by vibrator; Horizontal direction ・ Frequency of vibration by vibrator; 15 [ kHz]
・ Vibration amplitude: 10 [μm]
・ Maximum output of vibration by vibrator; 3500 [W]
・ Oil: Press washed rust preventive oil (Preton R-303P (mineral oil, viscosity = 3.9 [mm ² / S] (40 [° C.])), manufactured by Sugimura Chemical Co., Ltd.)
・ Oil supply method; dispenser / dull processing method; etching method / dull shape; average depth = 5 [μm], average diameter = 100 [μm], interval between concave shapes = 0.2 [mm] (= average Twice the diameter)

In FIG. 8, “vibration addition” indicates that the die not subjected to dull processing is joined by applying the minute vibration shown in the joining condition described above. Further, “dull processing” indicates that the die subjected to the dull processing shown in the above-described bonding conditions is bonded without giving a minute vibration.
Further, the “crack” refers to a crack on the surface of the material to be joined that is in contact with the die. When this “crack” is ◯, it indicates that no crack was generated, Δ indicates that a fine crack has occurred, and × indicates that a clear crack has occurred.

Further, “symmetry” refers to the symmetry of the rivet shape trace on the surface of the material to be joined that is in contact with the die. When this “symmetry” is ○, it indicates that the shape mark of the rivet was annulus, and for △, the shape mark of the rivet is not annulus, but is acceptable as a product aesthetic (beauty). The shape indicated by “×” indicates that the shape mark of the rivet was an unacceptable shape as a product aesthetic.
In addition, when the “overall determination” is “◎”, the result of the joining is good, and when the result is “x”, the result of the joining is bad.
As shown in FIG. 8, it can be seen that the aesthetics of the rivet joint can be improved by giving micro vibrations to the die in which oil is supplied to the recess, or by applying dull processing to the surface of the recess. In particular, when a 440 MPa grade steel plate and a 590 MPa grade steel plate are used as a material to be welded (a steel plate having a tensile strength of 440 MPa or more), the occurrence of cracks in the rivet joint can be suppressed, and the strength of the rivet joint can be stabilized and improved. I understand that I can do it.

(Example 2)
FIG. 9 is a diagram showing the results of Example 2. Example 2 is an example of the second embodiment.
The joining conditions in this example are as follows.
-Material to be joined: Cold-rolled steel sheet (thickness = 1.6 [mm], 2 layers)
・ Rivets: Steel rivets (diameter = 5.0 [mm], neck length = 6.0 [mm])
・ Lubricating sheet (resin film); polytetrafluoroethylene (thickness = 20 [μm])
As shown in FIG. 9, it can be seen that the aesthetic appearance of the rivet joint can be improved by inserting a resin film between the die and the material to be joined. In particular, when a 440 MPa grade steel plate and a 590 MPa grade steel plate are used as a material to be welded (a steel plate having a tensile strength of 440 MPa or more), the occurrence of cracks in the rivet joint can be suppressed, and the strength of the rivet joint can be stabilized and improved. I understand that I can do it.

(Example 3)
FIG. 10 is a diagram showing the results of Example 3. Example 3 is an example of the third embodiment.
The joining conditions in this example are as follows.
-Material to be joined: Cold-rolled steel sheet (thickness = 1.6 [mm], 2 layers)
・ Rivets: Steel rivets (diameter = 5.0 [mm], neck length = 6.0 [mm])
Solid lubricant; molybdenum disulfide As shown in FIG. 10, it can be seen that the aesthetics of the rivet joint can be improved by supplying the solid lubricant to the recess. In particular, when a 440 MPa grade steel plate and a 590 MPa grade steel plate are used as a material to be welded (a steel plate having a tensile strength of 440 MPa or more), the occurrence of cracks in the rivet joint can be suppressed, and the strength of the rivet joint can be stabilized and improved. I understand that I can do it.

In addition, among embodiment of this invention demonstrated above, the process of the control apparatuses 14, 45, and 63 is realizable when a computer runs a program. Further, a means for supplying the program to the computer, for example, a computer-readable recording medium such as a CD-ROM recording such a program, or a transmission medium for transmitting such a program may be applied as an embodiment of the present invention. it can. A program product such as a computer-readable recording medium that records the program can also be applied as an embodiment of the present invention. The programs, computer-readable recording media, transmission media, and program products are included in the scope of the present invention.
In addition, the embodiments of the present invention described above are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. Is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

1, 41, 61 Rivet welding device 3, 46 Die 3a, 46a Recess 4 Pad 5 Punch 13 Vibration applying device 14, 45, 63 Control device 15 Lubricating oil 21 Self-piercing rivet 42 Feeding device 43 Roller 44 Drive device 47 Resin film 62 Spraying device 100 Material to be joined

Claims (6)

A rivet joining method for joining a plurality of stacked workpieces using self-piercing rivets,
The concave portion of the die having a concave portion corresponding to the shape and size of the leg portion of the self-piercing rivet and the tip of the leg portion of the self-piercing rivet are opposed to each other through the plurality of materials to be joined. An arrangement step of arranging the self-piercing rivet,
Supplying step of supplying a dedicated lubricant for lubricating the die between the material to be joined, which is disposed closest to the die, among the plurality of materials to be joined, and the concave portion of the die. When,
A driving step of driving the self-piercing rivets arranged in the arrangement step into the plurality of materials to be bonded after the lubricant is supplied in the supply step;
Of the plurality of materials to be bonded, at least the material to be bonded arranged at a position closest to the die is a bare steel plate, an aluminum alloy plate, a steel plate having a surface plated, or a surface plated. An applied aluminum alloy plate,
The lubricant, a resin film, Ri lubricant or solid lubricant der,
In the driving step, a lubricant is supplied to a surface of the material to be bonded, which is disposed closest to the self-piercing rivet among the plurality of materials to be bonded, on the side where the self-piercing rivet is disposed. A rivet joining method , wherein the self-piercing rivet is driven into the plurality of materials to be joined in a state where the piercing rivet is not attached . On the surface forming the concave portion of the die, a plurality of irregularities are formed,
The average depth at the center of the plurality of concave openings formed by the plurality of irregularities is 5 [μm] or more and 20 [μm] or less,
The average diameter of the surfaces of the plurality of concave openings formed by the plurality of irregularities is 50 [μm] or more and 150 [μm] or less,
The distance between the centers of the plurality of concave openings formed by the plurality of irregularities is 1.5 times or more and 3 times or less of the average diameter,
The rivet joining method according to claim 1, wherein the lubricant is lubricating oil. At least when the self-piercing rivet is driven into the plurality of materials to be joined by the driving step in a state where the lubricant is supplied by the supplying step, the range is from 5 [μm] to 30 [μm]. A vibration imparting step of providing the die with a minute vibration having an amplitude selected from 1 and a frequency selected from a range of 1 [kHz] to 25 [kHz];
The rivet joining method according to claim 1, wherein the lubricant is lubricating oil. The supplying step supplies a dedicated lubricant for lubricating the die to the concave portion of the die,
The rivet joining method according to claim 1, wherein the lubricant is a lubricant or a solid lubricant. In the supplying step, a dedicated lubricant for lubricating the die is sent out between the material to be joined arranged at a position closest to the die and the concave portion of the die,
The rivet bonding method according to claim 1, wherein the lubricant is a resin film.   The tensile tension of the said to-be-joined material arrange | positioned at least in the position nearest to the said die among these several to-be-joined materials is 440 [MPa] or more, The any one of Claims 1-5 characterized by the above-mentioned. The rivet joining method according to item 1.

Images