JP2021146367A - Joining device and joining method - Google Patents

Abstract

To provide a joining device that has high joining quality of joining, in particular, a stud material to a material to be joined and is effective for achieving miniaturization, and a joining method using the same.SOLUTION: A joining device for joining a stud material to a material to be joined has a chuck for holding the stud material, a spindle for controlling rotation while holding the stud material on the chuck, and heating means for heating a joint of one or both of the stud material and the material to be joined. The heating means has a coil to which a high frequency is applied, pressing means which is composed of a magnetic body guide arranged along the outer circumference of the coil, and presses and controls the rotation-controlled stud material toward the material to be joined. and pressurizing means which stops the rotation of the stud material and controls upset-pressure toward the material to be joined.SELECTED DRAWING: Figure 1

Description

The present invention relates to an apparatus and a method for joining a stud material to a material to be joined.

Conventionally, the arc stud welding method has been used as a method for joining stud materials such as stud bolts in the manufacturing process of metal floor boards for bridges, tunnel interior boards, guide boards for highways, and the like.
In the arc stud welding method, the stud material is pressed and joined to the material to be joined in a state where a molten pool made of a molten material is formed between the stud material and the material to be joined by arc discharge.
However, in such a joining method, the pressing force tends to vary depending on the operator, and the stud material tends to be tilted.
In addition, the arc discharge is unstable, and the quality of the welded part and the joint strength tend to vary greatly due to the adhesion of oil, dust, etc. on the welded surface and the residual oxides, which causes problems such as poor joints and insufficient strength. I was afraid to do it.

Patent Document 1 describes an inspection step of detecting a welding pin in which a welding defect has occurred by applying an inspection current while applying a tensile force between the welding pin (stud material) and the material to be joined after the stud welding process. Disclose a stud welding method including.
However, although the technique disclosed in the same publication can detect welding pins with poor welding, it does not solve the problems of poor joining between the welding pin and the material to be joined and insufficient strength.

JP-A-2019-107674

The present invention has been made to solve the above-mentioned problems related to poor joining and insufficient strength, and in particular, a joining device for joining a stud material to a material to be joined, which has high joining quality and is effective for miniaturization. It is an object of the present invention to provide a joining method using.

The joining device according to the present invention is a joining device for joining a stud material to a material to be joined, and controls rotation while holding a chuck for holding the stud material and the stud material on the chuck. The heating means has a heating means for heating one or both joints of the stud material and the material to be joined, and the heating means has a coil to which a high frequency is applied and an outer circumference of the coil. A pressing means for pressing and controlling the rotation-controlled stud material toward the material to be joined, and a pressing means for stopping the rotation of the stud material and aiming at the material to be joined. It is characterized by having a pressurizing means for controlling upset pressurization.
Here, as the chuck, for example, a collet chuck whose tightening force is adjusted by pressure, hydraulic pressure, pneumatic pressure, electromagnetic force, or the like may be used.

When a high-frequency current is applied to the coil, a magnetic field is generated around the coil.
In this case, the magnetic flux generated in the magnetic field is generated not only in the inner peripheral portion of the coil but also in the outer peripheral portion.
When the stud material is placed inside the coil and joined to the material to be joined, it is preferable to intensively heat the inside of the coil, but the magnetic field generated on the outer periphery of the coil as described above heats the joint. Will not contribute to.
Therefore, the present invention is characterized in that the magnetic flux is concentrated on the inner joint portion of the coil by disposing the magnetic material guide on the outer peripheral side of the coil.
As a result, the temperature rise during heating of the joint portion is accelerated, and the joint can be joined with a smaller pressing force and in a shorter time than before.
Further, by rotating the stud material and pressing it against the material to be joined, heating is promoted by the friction of the pressing surface, and the rotational force due to the friction contaminates the oxides and oils held on the joint surface. The substance will be removed and the bonding quality will be improved.

In the present invention, the coil constituting the heating means may be a single-winding coil, and the magnetic material guide has slopes on one or both of the upper and lower surfaces along the inner peripheral surface for adjusting the magnetic flux distribution of the magnetic field. It may be a thing.
By disposing the magnetic guide on the outer peripheral side of the coil, the magnetic flux can be concentrated inside the coil, so that it is not necessary to increase the number of turns of the coil to strengthen the magnetic field.
In addition, the magnetic flux distribution of the magnetic field can be adjusted by adjusting the angle of the slope on the inner peripheral surface of the magnetic guide, and the magnetic flux is concentrated according to the diameter and material of the stud material placed inside the coil. Can be adjusted.
As a result, not only the stud material and the material to be joined may be made of the same metal, but the stud material and the material to be joined may be made of different materials.
If the stud material and the material to be joined are different metals, the magnetic permeability or conductivity will be different, but by adjusting the angle of the slope of the magnetic guide, of the joints between the stud material and the material to be joined. The magnetic flux can be concentrated on the metal side having high magnetic permeability or low thermal conductivity, and the joint portion between the stud material and the material to be joined can be efficiently heated.

The joining method according to the present invention includes a step of heating one or both joints of the stud material and the material to be joined by the heating means, and directing the stud material toward the joint surface of the material to be joined. It is characterized by having a step of rotationally pressing and then a step of stopping the rotation of the stud material and pressurizing the upset.
As a result, the stud material is joined to the material to be joined by upset pressurization after the stud material rotates and stops rotating.

In the joining device according to the present invention and the joining method using the same, the magnetic flux is concentrated on the joint portion inside the coil by arranging the magnetic material guide on the outer peripheral side of the coil, and the heating temperature of the joint portion is raised. Since the rise is accelerated and the maximum temperature reached is raised, the heating time can be shortened and the stud material can be joined to the material to be joined.
In addition, the joining quality is improved in the following points.
(1) By concentrating the magnetic flux on the joint portion, heat diffusion to the surface of the material to be joined is suppressed, the softening region in the vicinity of the joint portion due to the heat effect is reduced, joint defects are suppressed, and the joint quality is improved.
(2) By rotating the stud material and pressing it against the material to be joined, contaminants such as oxides and oils held on the joint surface are removed by the rotational force due to friction, and the joint quality is improved.
(3) By controlling the upset pressurization by the device, the variation in pressurization is eliminated and the joining quality is improved.
Further, since the softened joint portion can be joined with a small upset pressing force by the heating and friction according to the present invention, miniaturization of the joining device can be expected.
In the present invention, instead of the arc stud welding method, a plurality of stud materials can be continuously and continuously joined to the material to be joined with high joining quality.

An example of the positions of the coil and the magnetic material guide constituting the joining device according to the present invention is shown. An example of a magnetic material guide is shown. A configuration example of the joining device according to the present invention is shown. An example of the joining method according to the present invention is shown in a flowchart. The positional relationship between the stud material, the material to be joined, the coil and the magnetic material guide in this experiment is shown. The temperature distribution map of the joint portion by heating in this experiment is shown, (a) shows the result under the condition without the magnetic material guide, and (b) shows the result under the condition with the magnetic material guide arrangement.

In the present embodiment, the stud material 1 will be described as an example using a rod-shaped member as shown in FIG. 1, but the stud material 1 according to the present invention may be a pin, a bolt, or the like.
Further, the shape of the material to be joined 2 according to the present invention may be a flat plate, a flange surface or web surface of an I-beam, each surface of a cube, a cylindrical surface having a radius of curvature of 10 m or more, or a spherical surface, and a flat portion of the extruded profile, welding. Alternatively, it may be a flat portion of a member fastened with a bolt or the like.
The stud material 1 and the material to be joined may be, for example, various metal materials such as iron, steel, aluminum, and copper. Even if the stud material 1 and the material to be joined 2 are both metals of the same material, one of them may be made of the same material. It may be a heterogeneous joint made of different materials.

An example of the joining device according to the present invention will be described with reference to FIGS. 1 to 3.
The joining device 10 of this embodiment has a single-wound coil 12a and a magnetic material guide 12b arranged along the outer circumference of the coil 12a.
For convenience, the coil 12a and the magnetic material guide 12b are collectively referred to as the heating means 12.
As shown in FIG. 1, the magnetic material guide 12b is arranged along the outer circumference of the coil 12a, but may be arranged along the entire outer circumference of the coil 12a or only a part thereof. good.
Further, as shown in FIG. 2, the magnetic material guide 12b may have slope portions A and B vertically along the inner peripheral surface in order to adjust the magnetic flux distribution of the magnetic field.
The magnetic guide 12b may have only the slope portion A or the slope portion B, if necessary, and the angles of the slope portions A and B are the materials and sizes of the stud material 1 and the material to be joined 2. , It is preferable to determine by the thickness and the like.

The joining device 10 of the embodiment shown in FIG. 3 has a chuck 13 for holding the stud material 1 and a spindle 14 for controlling the rotation of the chuck 13 at the tip of the joining device main body 11, and the spindle 14 Pressing means 15 that presses and controls the stud material 1 whose rotation is controlled by And have.
All of the above components are comprehensively controlled and managed by the control management unit 17a built in the controller 17, and the controller 17 also includes an IH power supply 17b for applying a high frequency to the coil 12a and a cooling unit 17c. ing.
In the joining device 10 of this embodiment, an example in which an articulated robot arm is used as the joining device main body 11 is given so that the joining position of the stud material 1 can be easily controlled.
The joining device main body 11 may be a handy type or the like as long as the stud material can be positioned.
The controller 17 may be housed in a housing different from that of the joining device main body 11, or may be housed in the same housing as the joining device main body 11 and the joining device 10 may be formed as one unit.

In the embodiment shown in FIG. 3, the pressing force 15 between the stud material 1 and the material to be joined 2 is controlled by the pressing means 15 whose position in the Z-axis direction is servo-controlled by a ball screw or the like.
On the other hand, when the position control in the Z-axis direction is shared by the articulated robot arm, the pressing means 15 can be omitted.
Further, the heating means 12 may be fixed to the tip arm side of the articulated robot so that the relative position with respect to the stud material 1 is constant, and the center and height of the coil 12a and the magnetic material guide 12b can be adjusted. It may have an independent position control means as described above.
In the embodiment shown in FIG. 3, the output control means 12c for controlling the application of high frequency is connected to the heating means 12, but the output control means 12c may be built in the controller 17.

An example of a joining method using the joining device 10 of the above configuration example will be described together with the flowchart shown in FIG.
First, the stud material 1 is chucked on the chuck 13 (S1), and the coil 12a and the magnetic material guide 12b are positioned with respect to the material 2 to be joined in the X-axis direction, the Y-axis direction, and the Z-axis direction (S2).
The material 2 to be joined may be placed on the XY table 3 as shown in FIG. 3, and the positions in the X-axis direction and the Y-axis direction may be determined by moving the XY table 3.
As a result, positioning in the X-axis direction and the Y-axis direction becomes easy, and it becomes easy to continuously join a plurality of stud materials 1 to the joint material 2 even with a wide joint material 2.
Here, when the heating means 12 is fixed to the tip arm side of the robot, the position of the heating means 12 with respect to the stud material 1 is determined in conjunction with the chuck operation of the stud material 1, so that only the heating means is independent. Therefore, the mechanism for controlling the position can be omitted.

Next, the tip of the stud material 1 is positioned in the Z-axis direction (S3), a high frequency is applied to the coil 12a while controlling the application of the high frequency by the output control means 12c, and one of the stud material 1 and the material to be joined 2 is applied. Alternatively, both joints are heated (S4).
It may have an independent position control means for adjusting the center and height of the coil 12a and the magnetic guide 12b.
Even if the length of the stud material 1 is different, the position control means can be omitted by adjusting the chuck depth of the chuck 13 such as the collet chuck.
Specifically, an insertion restricting portion such as a flange portion is provided at a predetermined height from the tip of the stud material 1 so that the distance from the tip of the chuck 13 to the tip of the stud material 1 is the same. When the insertion restricting portion abuts on the tip of the chuck 13, the height of the tip of the stud material 1 becomes the same even if the stud materials 1 have different lengths.
When the stud material 1 and the material to be joined 2 are made of different metals, the joint portion is heated on the metal side having a large magnetic permeability or a small thermal conductivity, and when the same metal is used, only the material 2 to be joined or It is preferable to heat the joints of both the stud material 1 and the material to be joined 2.

While the joint portion is heated by the heating means 12 until a predetermined time or a predetermined temperature is reached, or after that, the stud material 1 rotated by the spindle 14 is rotationally pressed against the material to be joined 2 by the pressing means 15 (S5).
After that, the rotation of the spindle 14 is stopped (S6), and the stud material 1 is immediately upset and pressurized to the material to be joined 2 by the pressurizing means 16 (S7).
When the stud material 1 and the material to be joined 2 are different metals, the joint portion may be cooled immediately after pressurization.
Here, the coil 12a is preferably a single-winding coil so as not to interfere with the rotational pressing and the upset pressurization.
Since the single-winding coil has almost no thickness in the Z-axis direction, the rotary pressing and upset pressing can be performed while the coil 12a is arranged outside the stud material 1.
The magnetic guide 12b arranged along the outer circumference of the coil 12a preferably has substantially the same thickness as the coil 12a.
Finally, the stud material 1 is released from the chuck 11 (S8), and if the next stud material 1 is present, the above operation is repeated, and if not, the joining operation is terminated.

FIG. 6 is a temperature distribution map showing a difference in the temperature rise of the joint portion due to heating depending on the presence or absence of the magnetic material guide 12b.
FIG. 6A shows the result of applying a high frequency to the coil 12a in which the magnetic material guide 12b is not arranged, and FIG. 6B shows the result of applying a high frequency to the coil 12a in which the magnetic material guide 12b is arranged.
This experiment was carried out in the positional relationship shown in FIG. 5, and the stud material 1 is made of SS400 (JIS standard), which is a rolled steel material for general structure having a diameter of 16 mm and a length of 50 mm, and has a thickness of 20 mm. Also used SS400 as the material.
Further, a high frequency is applied to a coil 12a having a shape as shown in FIG. 1 made of copper having a diameter of 3 mm and an inner diameter of 20 mm.
As for the magnetic material guide 12b, a general-purpose material MB3 was used as a material, and a magnetic material guide 12b having a shape as shown in FIG. 2 and having C and D of 3 mm and E of 5 mm was used.

From the results, it can be seen that in FIG. 6 (b), the vicinity of the joint is heated at a higher temperature as compared with FIG. 6 (a), and the temperature rise is accelerated.
Further, the point A in FIG. 6 (a) was 80 mT / 720 ° C. and the point B was 750 mT / 890 ° C., whereas the point A in FIG. 6 (b) when the magnetic material guide 12b was arranged was The same is true because the temperature was 100 mT / 890 ° C. and the point B was 900 mT / 1120 ° C.
In this experiment, heating the joint to 800 ° C. required a heating time of about 60 to 90 seconds under the condition of FIG. 6 (a), whereas it required a heating time of about 60 to 90 seconds under the condition of FIG. 6 (b). If so, the heating time could be shortened to about 15 seconds.

According to the method of the present invention, a wide variety of metal stud materials can be joined to various metal plates and columns, and can be applied to, for example, manufacturing of highway guide plates and bridges.
With such technology, it is possible to develop a safe and secure infrastructure.

1 Stud material 2 Material to be joined 3 XY table 10 Joining device 11 Joining device body 12 Heating means 12a Coil 12b Magnetic material guide 12c Output control means 13 Chuck 14 Spindle 15 Pressing means 16 Pressurizing means 17 Controller 17a Control management unit 17b IH power supply 17c Cooling unit A Slope B Slope

Claims (3)

A joining device for joining a stud material to a material to be joined.
It has a chuck for holding the stud material and a spindle for controlling rotation while holding the stud material on the chuck.
It has a heating means for heating one or both joints of the stud material and the material to be joined.
The heating means comprises a coil to which a high frequency is applied and a magnetic material guide arranged along the outer circumference of the coil.
A pressing means for pressing and controlling the rotation-controlled stud material toward the material to be joined, and
A joining device comprising: a pressurizing means for stopping the rotation of the stud material and controlling upset pressurization toward the material to be joined. The coil constituting the heating means is a single-winding coil.
The joining device according to claim 1, wherein the magnetic guide has slopes on one or both of the upper and lower sides along the inner peripheral surface for adjusting the magnetic flux distribution of the magnetic field. A joining method using the joining device according to claim 1 or 2.
A step of heating one or both joints of the stud material and the material to be joined by the heating means.
A step of rotationally pressing the stud material toward the joint surface of the material to be joined, and
Next, a joining method characterized by having a step of stopping the rotation of the stud material and pressurizing the upset.

Images