JP3488275B2 - Hemming method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming method and apparatus for joining an outer plate and an inner plate of a work such as an engine hood and a door of an automobile.

[0002]

2. Description of the Related Art In the case of joining an outer plate and an inner plate of a work in the manufacture of an engine hood of an automobile or the like, hemming in which the end of the outer plate is folded back toward the surface of the end of the inner plate and gripped. Although processing is often performed, the outer plate and the inner plate may be displaced by just gripping them, and water or the like may enter the gap between the outer plate and the inner plate.

Therefore, conventionally, a hemming machine is used for a work in which an outer plate and an inner plate are assembled by interposing a thermosetting adhesive between the end of the outer plate and the end of the inner plate in advance. After the hemming process, the front side of the outer plate of the hemming part is heated by a separate heating device independent of the hemming device to semi-cure the thermosetting adhesive to form an outer plate and an inner plate of the work. Is temporarily adhered to the coating process, and then the entire work is heated in an oven to fully cure the adhesive to perform final adhesion. However, when the front side of the outer plate is heated in this way, deformation such as distortion due to heat is likely to occur on the front side of the outer plate, and the rust preventive oil applied to the outer plate surface solidifies and can be removed. There is a disadvantage that a difficult oil burning phenomenon is likely to occur. Further, when the heating device is provided as a separate body from the hemming processing device, there is a disadvantage in that the installation place for that is required separately from the hemming processing device in the factory production line, and the equipment cost is high. It was

On the other hand, as in Japanese Utility Model Laid-Open No. 62-193918, when performing the hemming process of pressing the end portion of the outer plate with the upper die and folding it back toward the surface of the end portion of the inner plate for gripping. , The nichrome wire provided in the outer plate pressing portion of the upper die is used as a heat source to heat the folded back portion of the outer plate end of the hemming portion, and the thermosetting adhesive that has been interposed in advance in the hemming portion is heated. Some harden. However, when a nichrome wire is provided as a heat source in the outer plate pressing portion of the upper die as described above, heat from the nichrome wire is conducted to the periphery of the nichrome wire, so that the outer die pressing part of the upper die that performs hemming is pressed. There is a risk that the part will be distorted due to heat, and in order to heat and cure the adhesive without adversely affecting the mold, a temperature sensor or the like is required in the mold and temperature control is required. There was the inconvenience of becoming complicated. Further, the route of heat conduction to the adhesive is in the order of the nichrome wire, the mold, the outer plate of the hemming portion, and the adhesive, and heating is performed through the mold and the outer plate. The outer plate also has a disadvantage that it is easily deformed by heat.

Further, as in JP-A-2-254070, a thermosetting adhesive is interposed between the end portion of the outer plate and the end portion of the inner plate to perform hemming, and then the outer plate of the hemming portion. There is also known one in which the adhesive is heated and cured by applying hot air to the folded-back portion of the end. However, in the case of heating with such hot air, it takes time to heat to a predetermined temperature, and the efficiency of the amount of heat given to the work by the heating amount of the heating means, that is, the thermal energy efficiency is poor, and it is practically used in mass production. It was not the target.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned inconvenience, and in heating a thermosetting adhesive preliminarily interposed in a hemming portion during hemming processing. In the manufacturing line of the factory, there is no need for an installation place separately from the hemming device, and there are few adverse effects such as heat distortion and oil burning phenomenon on the outer plate of the die for performing the hemming process and the hemming process part, and,
The present invention provides a hemming method and a device therefor, in which temperature control is easy, a temperature rising time is short, and thermal energy efficiency is high.

[0007]

According to the hemming method of the present invention, a thermosetting adhesive is intervened in advance in the hemmed portion that is gripped by folding back the end of the outer plate toward the surface of the end of the inner plate. Then, during the hemming process, only the inner plate in the vicinity of the hemming process part is heated, and the hemming process part is transmitted along the inner plate.
It is characterized in that the thermosetting adhesive is heated and cured by the heat conducted to the thermosetting adhesive.

The hemming processing apparatus of the present invention places a work piece in a state in which an outer plate and an inner plate are assembled with a thermosetting adhesive interposed between the end of the outer plate and the end of the inner plate. A lower die having a mounting portion for holding, an upper die having a punch for performing a hemming process in which the end of the outer plate is folded back toward the surface of the end of the inner plate and gripped, and an upper die. When the upper die is lowered toward the lower die and the punch performs hemming, only the inner plate near the hemming portion is heated .
Due to the heat transmitted through the inner plate to the hemming portion,
And a heating means for heating and curing the thermosetting adhesive .

In the hemming method and the apparatus therefor, it is preferable that the heating means is a high frequency induction heating coil.

[0010]

According to the present invention, the work in the state where the outer plate and the inner plate are assembled by interposing the thermosetting adhesive between the end of the outer plate and the end of the inner plate in advance is the lower mold. Is placed on the placing part of. The upper die moves down toward the lower die, and the punch provided in the upper die folds and grips the end of the outer plate of the work on the mounting part toward the surface of the end of the inner plate. Hemming is performed. During the hemming process, the heating means heats the inner plate near the hemming part. The heat from the heating means is conducted to the hemming portion through the inner plate, the thermosetting adhesive interposed in the hemming portion is heated and the adhesive is semi-cured, and the outer plate and the inner plate of the work are separated. Temporarily bonded.

In the case of high frequency induction heating,
During the hemming process, the high-frequency induction heating coil inductively heats the inner plate near the hemming process part, and the heat generated in the inner plate by the induction heating is conducted to the hemming process part through the inner plate, and the heat is applied to the hemming process part. The interposed thermosetting adhesive is heated to semi-cure the adhesive, and the outer plate and the inner plate of the work are temporarily bonded.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory cross-sectional view showing a part of a work in a state in which an outer plate and an inner plate before hemming are assembled in this embodiment.
FIG. 2 is an explanatory cross-sectional view showing a part of the work during hemming in this embodiment. FIG. 3 is an explanatory sectional view showing the overall structure of this embodiment. FIG. 4 is an explanatory sectional view of a part of the present embodiment when the upper mold is at the highest position. FIG. 5 is a partial explanatory cross-sectional view of this embodiment at the time of preliminary bending. FIG. 6 is a partial explanatory cross-sectional view of this embodiment during the actual bending process.

In FIG. 1, a work 1 is a state in which an outer plate 2 such as an engine hood and an inner plate 3 are assembled, and an end portion 4 of the outer plate 2 has a flange portion 4a. And inner plate 3
A thermosetting adhesive 6 is interposed between the end portion 5 and the end 5. The work 1 conveyed to a hemming processing device described later by a conveyor (not shown) is put into the hemming processing device, preliminarily bent (virtual line X) as described later by the hemming processing device, and then finally bent (virtual line Y )
After being hemmed, it is again discharged to a conveyor (not shown) and conveyed to the next step or the like.

The structure of the hemming device 7 will be described with reference to FIGS. 2, 3 and 4.

As shown in FIG. 3, the hemming device 7 has an upper die 8 and a lower die 9, and the upper die 8 reciprocates vertically toward the lower die 9 by a crank mechanism (not shown). Exercise.

At the bottom of the upper die 8, there is provided a main bending punch 10 projecting downward along the outer peripheral shape of the work 1 placed on the lower die 9, and the main bending punch 10 is at the top. It moves down toward the lower die 9 together with the die 8, and the bottom surface 10a of the main bending punch 10 is lowered to the lower die 9 as shown in FIG.
The end portion 4 of the outer plate 2 of the work 1 placed on is pressed and gripped on the surface of the end portion 5 of the inner plate 3. When the upper die 8 is at the lowest position, the main bending punch 10 completes the gripping.

Inside the main bending punch 10, there is provided a heating means 11 which projects downwardly in a circumferential shape at a distance from the main bending punch 10. The heating means 11 uses a high-frequency induction heating coil 13 as a heat source, and the periphery of the coil 13 is covered with a magnetic shielding material 14 except for the lower end surface.
Magnetic flux generated when electricity is applied to 3 is prevented from leaking except in the downward direction. An insulating material 12 is interposed between the upper die 8 and the high frequency induction heating coil 13. When the main bending punch 10 performs the main bending process, the heating means 11 also comes close to the inner plate 3 in the vicinity of the hemming process portion and the coil 13 is energized.
Induction heating of the inner plate 3 located in the magnetic flux generated from. When the upper die 8 is at the lowest position, the heating means 11
Is closest to the inner plate 3 near the hemming portion.

The lower die 9 is provided with a placing portion 15 for accommodating and placing the work 1 put into the hemming processing device 7. Around the placement unit 15, a guide unit 16 is provided for guiding the work 1 that has been conveyed from a conveyor (not shown) and is placed on the placement unit 15.
The guide portion 16 is provided with a slit 16a for inserting the pre-bending punch 20 from the side.

Around the outside of the guide portion 16, a support base 17 provided on the lower mold 9 side and a pre-bending pivotally supported on the support base 17 by a first link 18 and a second link 19 which are parallel to each other. A punch 20 is provided. The pre-bending punch 20 moves forward and backward in the slit 16a of the guide portion 16 as the first link 18 and the second link 19 rotate about the support base side shafts 21 and 22. Has become. The pre-bending punch 20 has a guide portion 1
6 is inserted through the slit 16 a of the workpiece 6 and protrudes onto the placing portion 15, the end portion 4 of the outer plate 2 of the work 1 placed on the placing portion 15
The flange portion 4a of is pressed and folded back toward the surface of the end portion 5 of the inner plate 3. The support base 17 has a lower stopper 17a with which the bottom portion 20a of the pre-bending punch 20 abuts when the pre-bending punch 20 is most protruded onto the placing portion 15, and the pre-bending punch 20 is most retracted from the placing portion 15 to the outside. Sometimes second
It has a side stopper 17b with which the upper edge 19a of the link abuts. Pre-bending punch side shaft 23 of the second link 19
Is connected to the support base side shaft 21 of the first link 18 by a return spring 24 and is always urged in the direction of the support base side shaft 21 of the first link 18, so that the pre-bending punch 20 is placed. It is constantly urged in the direction of retracting from the portion 15. The first link 18 is provided with a cam roller 26 supported by a shaft 25.

A cam top 27a and a cam upper slope 27b and a cam lower slope 27c, which are tapered upward and downward, sandwiching the cam top 27a, are provided outside the portion of the bottom of the upper mold 8 facing the support base 17. Cam driver 2 having a provided cam
8 is provided so as to project downward. When the upper die 8 descends from the highest position, the cam lower slope 27c of the cam driver 28 contacts the cam roller 26, pushes the pre-bending punch 20 toward the mounting portion 15 and projects it onto the mounting portion 15. Let The cam top portion 27 a of the cam driver 28 contacts the cam roller 26 when the pre-bending punch 20 is most projected on the mounting portion 15.

At the inner portion of the cam driver 28 at the bottom of the upper die 8, there is a cam return 29 which is located above the cam top 27a of the cam driver 28 and has a return lower slope 29a parallel to the cam upper slope 27b. Is provided. When the cam driver 28 descends lower than when the cam top 27a is in contact with the cam roller 26, the return lower slope 29a contacts the shaft 25 of the cam roller 26 and returns the cam roller 26 to the lower slope 29a and the cam top. The pre-bending punch 20 is immobile by pushing it back in a direction away from the mounting portion 15 along with the inclined surface 27b to retract the preliminary bending punch 20 laterally from the mounting portion 15. When the upper die 8 is at the lowermost position, the cam roller 26 is between the cam return 29 and the cam driver 28, and the inner wall surface 2 that is continuous with the lower return slope 29 a of the cam return 29.
It touches 9b.

The operation of this embodiment will be described below.

As shown in FIG. 4, the upper mold 8 reciprocates in the vertical direction by a crank mechanism (not shown). When the upper mold 8 is at the highest position, the upper mold 8 is moved.
The main bending punch 10 provided in the
Retracted above 5. Further, the second link 19 is pulled by the tension of the return spring 24 and is held at a position where it hits the side stopper 17b provided on the support stand 17, and is thereby pivotally supported by the first link 18 and the second link 19. The preliminary bending punch 20 is retracted to the side of the mounting portion 15.

When the upper mold 8 is in the above-mentioned position, the thermosetting adhesive 6 is preliminarily interposed between the end 4 of the outer plate 2 and the end 5 of the inner plate 3 and assembled. The workpiece 1 in which the end portion of the outer plate 2 is raised in a flange shape is conveyed to the hemming processing device 7 by a conveyor (not shown), guided by the guide portion 16 of the lower die 9, and placed on the mounting portion 15. Placed.

Next, as shown in FIG. 5, when the upper mold 8 starts to descend, the cam driver 28 of the upper mold 8 also descends, and the cam lower slope 27c of the cam driver 28 mounts the cam roller 26. The first and second parts are pushed out toward the placing part 15
The links 18 and 19 rotate around the support-side shafts 21 and 22 in the direction of the mounting portion 15, and the pre-bending punch 20 inserts the slit 16a of the guide portion 16 obliquely downward from the side of the mounting portion 15. The flange portion 4a of the end portion 4 of the outer plate 2 of the work 1 placed on the placing portion 15 is pressed obliquely downward from above the outer side and folded back toward the surface of the end portion 5 of the inner plate 3. When the cam top portion 27a of the cam driver 28 of the upper die 8 is in a position in contact with the cam roller 26, the pre-bending punch 20 moves from the slit 16a of the guide portion 16 to the mounting portion 15.
The bottom portion 20a of the pre-bending punch 20 projects most upwardly and abuts on the lower stopper 17a of the support base 17.

As shown in FIG. 6, when the upper mold 8 is further lowered, the lower return slope 29a of the cam return 29 provided on the upper mold 8 comes into contact with the shaft 25 of the cam roller 26, and the cam roller 26. The mounting portion 1 is provided between the lower return slope 29a of the cam return 29 and the upper cam slope 27b of the cam driver 28.
Push back in the direction away from 5, and the first and second links 1
8 and 19 are mounting parts 1 centering on the support stand side shafts 21 and 22.
The pre-bending punch 20 rotates in a direction away from 5, and retracts obliquely upward from the mounting portion 15 through the slit 16a of the guide portion 16.

Then, the pre-bending punch 20 is mounted on the mounting portion 15.
Bending punch 10 instead of retreating to the side of
Then, the heating means 11 descends toward the work 1 on the mounting portion 15, and the main bending punch 10 presses the folded flange portion 4a of the end portion 4 of the outer plate 2 from above, and the inner plate 3 is pressed.
Grab it on the surface of the end 5 of the.

During the hemming process, as shown in FIG. 2, the heating means 11 is also in the magnetic flux generated by the energized high frequency induction heating coil 13 near the inner plate 3 near the hemming part. The inner plate 3 is induction-heated. The heat of the inner plate 3 that has been induction-heated is transmitted through the inner plate 3 to the hemming processing portion, and the thermosetting adhesive 6 interposed in the hemming processing portion.
Is heat-cured, and the outer plate 2 and the inner plate 3 are temporarily bonded. A magnetic shield 14 is disposed around the coil 13 to prevent the leakage magnetic flux from affecting the die.

After that, the upper die 8 starts to rise again. When the upper die 8 reaches the highest position, both the main bending punch 10 and the preliminary bending punch 20 are retracted above and on the side of the placing portion 15, and at this position, the hemmed work 1 is The work 1 is delivered from the placement unit 15 to a conveyor (not shown) and conveyed to the next step, and a new work 1 is placed on the placement unit 15 instead.

[0030]

According to the present invention, since the thermosetting adhesive previously intervened in the hemming portion is heat-cured by heating only the inner plate in the vicinity of the hemming portion, the work outside the hemming portion is processed. It is possible to prevent adverse effects such as heat distortion of the plate and oil burning phenomenon of the outer plate.

Since the upper die for hemming can be constructed by adding a heating means to the upper die, it is not necessary to significantly change the existing die, and the heating device is separate from the hemming device in the factory production line. There is no need to occupy the installation place.

Further, particularly in the case of high frequency induction heating, since only the portion where electromagnetic induction occurs in the magnetic flux generated by the energized high frequency induction heating coil can be intensively and rapidly heated at high temperature, the die It is possible to effectively prevent adverse effects such as heat distortion on the outer plate and the outer plate, and to perform work in a short time with a short heating time and high thermal energy efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory cross-sectional view showing a part of a work 1 in a state where an outer plate and an inner plate before hemming of the present embodiment are assembled.

FIG. 2 is an explanatory sectional view showing a part of a work at the time of hemming processing according to the present embodiment.

FIG. 3 is an explanatory sectional view showing the overall structure of the present embodiment.

FIG. 4 is an explanatory cross-sectional view of a part of the present embodiment when the upper mold is at the highest position.

FIG. 5 is an explanatory cross-sectional view of a part of the present embodiment at the time of pre-bending.

FIG. 6 is an explanatory cross-sectional view of a part of this embodiment at the time of actual bending.

[Explanation of symbols]

1-Workpiece, 2-Outer plate, 3-Inner plate, 4-End of outer plate, 5
-End of inner plate, 6-thermosetting adhesive, 7-hemming machine, 8-upper mold, 9-lower mold, 10-bending punch, 11-heating means, 13-high frequency induction heating coil,
15-placement part, 20-preliminary bending punch

Front Page Continuation (72) Inventor Toshio Emori 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Within Honda Engineering Co., Ltd. (56) Reference JP-A-2-217121 (JP, A) Jitsuko Sho 4848-12 (JP, Y2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B21D 19/08 B21D 39/02 B21D 53/88

Claims (4)

(57) [Claims] Claim: What is claimed is: 1. A thermosetting adhesive is preliminarily interposed in a hemming portion which is folded and gripped by folding the end portion of the outer plate toward the surface of the end portion of the inner plate. Hemming by heating only the inner plate in the vicinity and passing through the inner plate
A hemming method, wherein the thermosetting adhesive is heat-cured by heat conducted to a processed portion . 2. The thermosetting adhesive is heat-cured by high-frequency induction heating the inner plate.
The described hemming method. 3. A mounting portion for mounting a work piece in a state where an outer plate and an inner plate are assembled with a thermosetting adhesive interposed between the end portion of the outer plate and the end portion of the inner plate. A lower die, an upper die with a hemming punch that folds the end of the outer plate toward the surface of the end of the inner plate for gripping, and an upper die provided on the upper die When the die descends toward the lower die and the punch performs the hemming process, only the inner plate near the hemming process is heated and the hemin is transferred along the inner plate.
The thermosetting adhesive is heated and hardened by the heat conducted to the processing part.
Hemming apparatus characterized by having heating means for reduction. 4. The hemming processing apparatus according to claim 3, wherein the heating means is a high frequency induction heating coil.