JPH11185944A - Pre-curing device for sheet metal work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pre-curing device capable of efficiently applying a pre- cure treating to a sheet metal component and abundant in flexibility. SOLUTION: The moving sections 22, 24, 26, 28 of a robot 20 are driven to position a high-frequency heating coil 10 fitted to the hand 28 at the required portion of a sheet metal component 2. A high-frequency current is fed to the high-frequency heating coil 10 from a high-frequency power supply 30 to heat the sheet metal component 2 via a high frequency, an adhesive applied to the sheet metal component 2 is hardened, and the outer plate of the sheet metal component 2 and a reinforcing plate are temporarily fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating type pre-curing apparatus, and more particularly to a high-precision pre-curing apparatus having a high-frequency heating coil mounted on a robot hand to efficiently perform pre-curing processing of sheet metal works of various shapes. Related to the device.

[0002]

[Related Background Art] In the production process of vehicles, doors,
An outer plate of a body part such as a hood hood and a trunk is joined to a reinforcing material in a hemming process. This body part is conveyed to the painting process after being assembled to the body body. At this time, during the transfer from the hemming step to the coating step or during the heating step in the coating step, the relative displacement and deformation of the body parts are likely to occur. Conventionally, in order to prevent such displacement, the outer plate of the body component subjected to the hemming process and the reinforcing material are temporarily fixed by spot welding or laser welding. However, temporary fixing by spot welding has an inconvenience that an indentation is left at a welding site. On the other hand, temporary fixing by laser welding requires a considerable capital investment, and if the laser beam is too strong, a pinhole is generated in the body part, which often causes a problem in controlling the intensity of the laser beam.

Therefore, a thermosetting adhesive is applied between the outer plate of the body component and the reinforcing material, and then the body component is heated to cure the adhesive, thereby temporarily fixing the outer plate and the reinforcing material. A so-called precure process is often performed. Various methods such as hot-air heating, infrared heating, and high-frequency heating are used for heating the body part in the precure treatment. In the case of high-frequency heating, a jig generally having a high-frequency heating coil embedded in a groove having substantially the same outer shape as the body part and formed over the entire circumference is used. Then, a high-frequency current is applied to the high-frequency heating coil with the thermosetting adhesive applied in advance and the hemmed body component placed on the jig to generate an alternating magnetic field, and the induced current generated in the body component is generated. The heat is used to cure the thermosetting adhesive to temporarily fix the body parts.

[0004]

However, in the high-frequency heating apparatus for pre-curing, the high-frequency heating coil is arranged only below the body part. In general, a high-frequency heating coil is formed by forming a single pipe in a spiral shape and providing a large number of circular coil portions. When such a high-frequency heating coil is disposed in an outer circumferential groove of a jig, a circular shape is formed. Each of the coil portions is arranged in such a direction that its axis crosses the body part obliquely, and the density of lines of magnetic force crossing the body part is reduced. Therefore, the heating efficiency is low, the power consumption is large, and the heating requires time. Further, in order to compensate for the low heating efficiency, it is necessary to use a high-output type device, and in this case, the capital investment cost increases. Further, since only the lower surface of the body component is heated, a difference occurs between the amount of heat input to the upper surface of the body component and the amount of heat input to the lower surface, resulting in a temperature difference between the upper and lower surfaces of the body component, and thermal distortion of the body component. . In order to perform the precure process using the above-described apparatus, as described above, a special jig having substantially the same outer shape as the body part and having the high-frequency heating coil embedded therein is required. Therefore, in order to perform a pre-curing process on body parts having various shapes, a dedicated jig is required for each body part. Further, in order to respond to a request to manufacture various kinds of vehicles on the same production line, more dedicated jigs are required.

Accordingly, the present invention provides a versatile sheet metal work pre-curing apparatus capable of efficiently performing a pre-curing process on a sheet metal work such as a body part without using a dedicated jig for a work of a different type. The purpose is to:

[0006]

SUMMARY OF THE INVENTION In a precure apparatus for temporarily fixing works by hardening an adhesive applied to an overlapped portion of a sheet metal work by high-frequency heating, the precure apparatus according to the present invention comprises: A high-frequency heating coil formed so as to be sandwiched from both sides at a predetermined interval with respect to the portion, and a positioning device provided with a coil holding portion for holding the high-frequency heating coil. Characterized in that it is positioned with respect to.

According to the precure apparatus of the present invention, the high-frequency heating coil is positioned with respect to the work, and a high-frequency current is applied to the high-frequency heating coil to cure the adhesive applied to the overlapping portion of the sheet metal work. Then, the workpieces can be temporarily fixed. The apparatus of the present invention can position the high-frequency heating coil with respect to any part of the work, and it is necessary to prepare a dedicated jig having the same shape as the work and embedding the high-frequency heating coil for each type of work. There is no. For this reason, it is possible to carry out a precure process for works of various shapes.

In addition, a high-frequency heating coil can be positioned at a required work site to heat an arbitrary work site by high-frequency heating.
Therefore, it is possible to improve the precure treatment efficiency by, for example, performing high-frequency heating only on the most effective and effective work portion for temporarily fixing the work. If necessary, high-frequency heating can be performed over the entire circumference of the work, and the temporary fixing strength can be improved.

Further, the high-frequency heating coil has a high degree of freedom in setting the shape of the high-frequency heating coil, and the high-frequency heating coil can be appropriately set for different workpieces and positioned in an appropriate direction, so that the high-frequency heating coil can be set in a proper direction. The heating efficiency can be improved by increasing the density of the generated magnetic force lines. In the present invention, preferably, the positioning device includes a robot having a hand that functions as the coil holding unit and an arm that functions as the movable unit.

According to the pre-curing apparatus having such a preferable configuration, the high-frequency heating coil can be quickly and accurately positioned with respect to the work by applying a known robot control technique, and the pre-curing process can be efficiently performed. . Preferably, the high-frequency heating coil includes a first coil portion extending in a loop in a first plane, and a second coil portion extending in a loop in a second plane parallel to the first plane with the work interposed therebetween. Connected between the first coil portion and the second coil portion.
And a third coil portion extending linearly in a third plane orthogonal to the second plane. The first, second, and third coil portions define a space that can accommodate at least an outer edge portion of the work.

According to the precure device having such a preferable configuration, the high-frequency current is caused to flow while the outer edge portion of the work is accommodated in the space defined by the first, second, and third coil portions. The lines of magnetic force generated by the coil section can be perpendicular to the upper and lower surfaces and the outer side surface of the work,
High-frequency heating can be performed efficiently from the top and bottom and the side of the work, and the heating efficiency is improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a precure device according to an embodiment of the present invention will be described. As shown in FIG. 1, the pre-curing apparatus of the present embodiment includes a robot 20 equipped with a high-frequency heating coil 10 as a positioning device, and positions the high-frequency heating coil 10 with respect to a sheet metal work such as a body part to be pre-cured. Then, a high-frequency current is applied to the coil 10 to cure the adhesive applied to the work by high-frequency heating.

The high-frequency heating coil 10 is formed, for example, by bending a single hollow copper pipe as schematically shown in FIG. 4, and a high-frequency current flows through the peripheral wall of the copper pipe to cool the hollow part of the copper pipe. Water is flowing. The outer peripheral surface of the copper pipe is coated with a ceramic coating or coated with an electrically insulating resin. When it is coated with an electrically insulating resin, it has excellent maintainability.

In FIG. 4, the high-frequency heating coil 10 comprises:
A first straight portion 10a, a first rising portion 10b extending upward in the vertical plane from the straight portion 10a, a first coil portion 10c extending circularly in the first horizontal plane from the rising portion 10b, and a coil portion 10c , A falling portion 10d extending downward in a vertical plane, a second coil portion 10e extending in a circular shape from the falling portion 10d in a second horizontal plane separated from the first horizontal surface, and an upward portion in a vertical plane from the coil portion 10e. And a second straight portion 10g extending from the rising portion 10f. First and second
The coil portions 10c and 10e cooperate with other coil elements to define a space 10h capable of accommodating a work, for example, an outer edge portion of the hood 2, as shown in FIG. In FIG.
The arrows indicate the direction of the current in one half cycle of the high frequency current. In the next half cycle, the high-frequency current flows in the direction opposite to the arrow.

FIGS. 5 and 6 show another high-frequency heating coil having a different shape from the high-frequency heating coil 10 shown in FIGS. As schematically shown in FIG. 6, the high-frequency heating coil 110 has coil elements 110a to 110g corresponding to the coil elements indicated by reference numerals 10a to 10g in FIG. Both high-frequency heating coils 10, 1
The main difference of 10 is that the former coil portions 10c and 10e are circular, while the latter coil portions 110c and 110e are circular.
e is formed in a U-shape.

As shown in FIG. 5, the high-frequency heating coil 11
0 is supported by the coil support 112. The coil support 112 includes a first support portion 112a having a vertical wall through which the first linear portion 110a of the coil 110 penetrates and a horizontal wall supporting the linear portion 110a, and a second support configured similarly to the support portion 112a. Section 112b. Both support parts 1
An electric insulating plate 114 made of, for example, bakelite is disposed between 12a and 112b.

The high-frequency coil 10 shown in FIG. 3 is supported by a coil support (not shown) having the same configuration as the coil support 112 shown in FIG. As shown in FIG. 1, a robot 20 of the precure device includes a swivel table 22 that can swivel with respect to a floor on which the robot is disposed, a first arm 24 that can swing with respect to the swivel table 22, and an arm 24. And a hand 28 attached to the tip of the arm 26. The hand 28 is provided so as to be swingable with respect to the second arm 26 and pivotable around the longitudinal axis of the arm 26, and is provided so as to hold the high-frequency heating coil 10. For example, the high-frequency heating coil 10 is fixed to the hand 28 by bolting a coil support of the high-frequency heating coil 10 to an end bracket (not shown) of the robot hand 28 as a coil holding unit.

The robot 20 includes a required number of servomotors that operate under the control of a robot controller (not shown), and includes a swivel 22, arms 24 and 26, and a hand 28.
That is, the movable part of the robot is swung by the servomotor.
By rotating, the high-frequency heating coil 10 fixed to the hand 28 is positioned at an arbitrary part of the work to be precured.

The linear portions 10a and 10g of the high-frequency heating coil 10 are connected to a high-frequency power source 30 through an electric cable and a cooling water hose (collectively indicated by reference numeral 29 in FIG. 2).
It is connected to the. The high frequency power supply 30 has a hose 31a
The cooling water is supplied from the cooling device 32 via the. The water used for cooling the high-frequency heating coil 10 is returned to the cooling device 32 via the hose 31b and cooled, and then reused for cooling the high-frequency heating coil 10.

The high-frequency power supply 30 is controlled by a higher-level controller (not shown) in the process control panel 36 and operates under the control of a low-level controller (not shown) provided in the heating condition panel 34 to generate a high-frequency heating coil. A high frequency current of, for example, 10 KHz is supplied to 10 or 110. On the input side of the controller of the heating condition panel 34, a thermometer for measuring the work surface temperature, for example, a radiation thermometer 38 is connected. The radiation thermometer 38 is mounted on, for example, the upper surface of the positioning jig 4 (FIG. 1).

Hereinafter, the operation of the pre-curing apparatus having the above configuration will be described. This precure device is a hood 2 shown in FIG.
Various body parts such as doors and doors (more generally works)
Applied to the precure treatment. When the hood 2 is subjected to the precure treatment, the outer panel 2a and the inner panel 2b of the door 2 are joined to each other in a hemming step before the precure treatment, and a thermosetting adhesive is applied to the joint surface of both panels as shown in FIG. You. In the case of the hood 102, the adhesive is applied between the outer plate of the hood 102 and the reinforcing plate as shown in FIG.
As shown by a broken line in FIG.

A work to which an adhesive is applied, for example, a hood 2
The upper and lower edges are clamped by, for example, four pneumatic clamping mechanisms 6 provided on the positioning jig 4, and are supported on the positioning jig 4. When the hood 2 is clamped, the air cylinder 6b attached to the clamp mechanism body 6a
Compressed air is supplied from a pressurized air source (not shown) to drive the clamp piece 6c in the locking direction via the movable rod of the air cylinder 6b, and the hood 2 is moved by the clamp mechanism body 6a and the clamp piece 6c. Pinch.

The positioning jig 4 is more versatile than a conventional dedicated jig in which a high-frequency heating coil is embedded. However, the clamping jig 4 is provided on the positioning jig 4 so as to be able to move horizontally. May be further improved. On the other hand, prior to the precure process, the high-frequency heating coil 1 for the workpiece in the precure process is used.
The target position of the positioning of 0 or 110 (specifically, the turning position of the swivel base 22, the swinging positions of the arms 24 and 26, and the swinging / turning positions of the hand 28) is determined for each type of work, and also for the pre-curing of the work. The robot controller is taught for each position. In the case of the hood 102, four precure sites 102a to 1021 shown by hatching in FIG.
The target position of the high-frequency heating coil corresponding to 02d is sequentially taught.

When the pre-curing apparatus is operated after the above preparation is completed, cooling water circulates between the cooling apparatus 32 and the high-frequency heating coils 10 and 110 via the cooling water hoses 29, 31a and 31b. When a command indicating the type of work (door, hood, etc.) to be subjected to the pre-curing process is supplied from a higher-level controller of the process control panel 36, the controller of the heating condition panel 34 sets the work surface temperature before the pre-curing process to the radiation temperature. The target heating temperature is set by correcting the tentative target heating temperature read from the total 38 and predetermined from the memory built in the controller in accordance with the type of the work with the surface temperature, and further, the target heating temperature is obtained. Set a target high frequency current value. By performing such a target heating temperature setting, the influence of the work temperature fluctuation is eliminated. In addition, by controlling the high-frequency current in this way, it becomes possible to control the heating temperature while fixing the control parameters such as the heating time for each work, and the practicality of the pre-cure device is improved.

Next, under the control of a robot controller (not shown), each axis servo motor is driven to drive the turntable 22, the arms 24, 26 and the hand 28 of the robot 20, and the high-frequency heating coil 10 or 110 is Position at the first precure position. Upon completion of the positioning of the high-frequency heating coil, the controller of the heating condition panel 34 outputs the target value of the high-frequency current from the high-frequency power supply 30 for a predetermined time according to the type of the work.
The high frequency power supply 30 is controlled. During the power supply control, the controller controls the high-frequency power supply 30 in consideration of the supply current value from the operation power supply for the high-frequency power supply 30 detected by the current sensor 39 (FIG. 2).

When a high-frequency current output from the high-frequency power supply 30 flows through the high-frequency heating coil 10 or 110, the circular coil portions 10c and 10e of the coil 10 or the coil 1
The ten U-shaped coil portions 110c and 110e are connected to the hood 2
An alternating magnetic field (indicated by a two-dot chain line in FIG. 5) crossing the joint (corresponding to the folded portion of the outer panel 2a) between the outer panel 2a and the inner panel 2b. When the coil 10 or 110 is positioned as shown in FIG. 3 or FIG.
The distal ends of the e or U-shaped coil portions 110c and 110e are located almost directly above the edge 2c of the outer panel 2a, and the base end is located outside the side edge 2d of the hood 2 (panel joint). That is, the circular coil portion and the U-shaped coil portion have longitudinal dimensions slightly longer than the depth dimension of the panel joint. For this reason, the magnetic field lines of the alternating magnetic field generated by the circular or U-shaped coil portion cross substantially the entire depth region of the panel joint.

Then, an induced current due to the alternating magnetic field is generated in both panels, heat is generated in the panels 2a and 2b by the induced current, the two panels are heated, and the adhesive in the heated portion is thermoset. In FIG. 5, symbol A indicates an induced current flowing through the outer panel 2a. Since the circular coil portion of the high-frequency heating coil 10 or the U-shaped coil portion of the coil 110 has the above dimensions, the allowable positioning error of the coil 10 or 110 can be relatively large. That is, even when the positioning of the high-frequency heating coil is misaligned, the magnetic field lines pass through the entire depth region of the panel joining portion, so that the precure process is reliably performed.

Although not shown, the rising and falling portions 10b, 10d, and 10f (or 110b, 110d, and 110b) of the high-frequency heating coil 10 (or 110).
110f), the outer panel 2
An alternating magnetic field that crosses in the horizontal direction perpendicular to the bent portion a (the end surface on the peripheral edge 2d side of the hood 2) is generated, and an induced current is generated at the end surface of the bent portion to heat the portion.
As a result, the adhesive is hardened at the first precure position of the hood 2, and the outer panel 2a and the inner panel 2b are temporarily fixed.

As described above, since both the upper and lower surfaces of the work and the end surface of the work can be heated simultaneously, the heating efficiency is high,
The heating time is reduced. Further, the heating temperature difference between the upper and lower surfaces of the work is extremely small, and the thermal distortion at the pre-cure position is greatly reduced. Further, the work is not heated except at the precure position, and unnecessary work heating can be prevented. Next, while the high-frequency heating coil 10 or 110 is positioned at the second pre-curing position, a high-frequency current is supplied to the high-frequency heating coil to temporarily fix the panels at the pre-curing position. In the same manner, the temporary fixing is performed at the remaining precure positions.

In the case of the hood 102, a precure process is performed on the precure portions 102a to 102d shown in FIG. As shown in FIG. 7B, the precure position is set around the bent portion of the hood 102. By setting the precure position in this way, while reducing the number of precure positions and shortening the precure processing time,
The required precure strength can be achieved.

The body parts such as the hood 2 and the hood 102 which have been subjected to the precure treatment as described above are shown in FIG.
As shown in (c), it is assembled to the body 103 and transferred to the painting process. The panels 2a and 2b of the hood 2 and the outer plate and the reinforcing plate of the hood 102 on which the above-mentioned precure treatment has been performed are temporarily fixed with a required strength.
The deformation of the hood 2 and the hood 102 during transportation to the painting process or during charging into the baking furnace in the painting process is suppressed. Then, the entire adhesive is heated in the furnace of the coating process, and the body design strength is achieved.

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the hemmed sheet metal work (for example, the panel 2 of the hood 2)
Although the case where a and 2b) are set as the objects of the pre-curing process has been described, the present invention can also be applied to the pre-curing process of other works such as simply two plates arranged in parallel.

Further, in the precure apparatus of the present invention, FIG.
Alternatively, a different type of high frequency heating coil than that shown in FIG. 6 can be used. For example, the coil configuration shown in FIG. 4 can be modified as shown in FIG. In FIG. 8, the high-frequency heating coil 210 has two circular coil portions 210c, 21c.
0e, and the coil portion 210e includes a connection portion 210i,
They are connected to the straight portions 210a and 210g via 210j.

Further, in the above embodiment, the robot 20 of the type shown in FIG. 1 is used as a positioning device, but various positioning devices including other types of robots can be applied to the present invention.

[0035]

The precure device of the present invention includes a positioning device provided with a coil holding portion for holding the high-frequency heating coil, and the positioning device positions the high-frequency heating coil with respect to the sheet metal work. Precure processing for sheet metal works such as can be performed efficiently without using dedicated jigs for works of different types, and is versatile. In addition, the high-frequency heating coil can be positioned at a required work portion to heat any work portion with high frequency, thereby improving the efficiency of the pre-curing process. If necessary,
High frequency heating can be performed over the entire circumference of the work, and the temporary fixing strength can be improved. Furthermore, the degree of freedom in setting the shape of the high-frequency heating coil is high, and by appropriately setting the shape of the high-frequency heating coil and positioning it in an appropriate direction,
Heating efficiency can be improved by increasing the density of magnetic lines of force generated by the high-frequency heating coil.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a precure device according to an embodiment of the present invention.

FIG. 2 is a block diagram of the precure device shown in FIG.

FIG. 3 is a partial perspective view showing a state in which the high-frequency heating coil shown in FIG. 1 is positioned with respect to a hood to be subjected to a pre-curing process.

FIG. 4 is a diagram schematically showing the high-frequency heating coil shown in FIGS. 1 and 3;

FIG. 5 is a partial perspective view showing another type of high-frequency heating coil shown in FIGS. 1, 3 and 4 in a state where it is positioned with respect to a hood.

FIG. 6 is a view schematically showing the high-frequency heating coil shown in FIG. 5;

FIG. 7 is a perspective view showing a region where an adhesive is applied to a hood before a precure process, a precure process position of the hood, and an assembled state of the hood and a door to a body main body.

FIG. 8 schematically shows a high-frequency heating coil of a type similar to that shown in FIGS. 1, 3 and 4;

[Explanation of symbols]

2 Hood 10, 110, 210 High frequency heating coil 10a, 10g, 110a, 110g, 210a, 21
0g Straight section 10b, 10f, 110b, 110f, rising section 10c, 10e, 110c, 110e, 210c, 21
0e Coil part 10d, 110d Falling part 20 Robot 24, 26 Arm 28 Hand 30 High frequency power supply 102 Hood

Claims (1)

[Claims] 1. A pre-cure apparatus for temporarily fixing works by hardening an adhesive applied to an overlapped portion of a sheet metal work by high-frequency heating, wherein the work is sandwiched from both sides at a predetermined interval with respect to the overlapped portion of the sheet metal work. A high-frequency heating coil formed as described above, and a coil holding portion that holds the high-frequency heating coil is provided, and a positioning device that positions the high-frequency heating coil with respect to the sheet metal work is provided. Precure device.