JPH105885A - Hemming method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent troubles such as buckling in which a tip of a flange is hooked by a formed surface of a bending blade during the bending by moving the bending blade in a copying manner to the moving locus of the tip of the flange. SOLUTION: A work W which is a pressed article is positioned at the working position by a lower die 13. The work W is loaded on a receiving surface 13u. A flange wf formed on an edge of the work W is folded using a bending blade 16s and the lower die 13. The bending blade 16s is moved in a copying manner to the moving locus E of the tip of the flange wf. Because a pre-bending blade (bending blade) 16 is advanced in a copying manner to the moving locus E of the tip of the flange wf of the work W, a formed surface 16f of the pre- bending blade 16s is little rubbed by the tip of the flange wf. Secular generation of a recess, etc., in the formed surface of the bending blade can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming method for bending a flange formed on an edge of a pressed product using a bending blade and a lower die.

[0002]

2. Description of the Related Art FIG. 8 is a processing diagram showing a conventional hemming method related to this, and FIG. 9 is a longitudinal sectional view of a main part of the apparatus. The hemming device 1
As shown in FIG. 9, a bed 2 is provided, and a lower mold 3 and a fixing bracket 4 are placed on the bed 2. The lower die 3 is a die for holding a pressed product (hereinafter, referred to as a work w) at a processing position, and includes a receiving surface 3u on which the work w is placed. A pre-bracket 6 having a pre-blade 6s is disposed between the lower die 3 and the fixed bracket 4, and the pre-bracket 6 is connected to the fixed bracket 4 via a link mechanism 5.

The link mechanism 5 comprises a pair of link blocks 5a, 5b and supporting shafts 4a, 6a, 4b, 6b rotatably supporting the respective link blocks 5a, 5b. 5a and 5b are arranged parallel to each other at the oblique upper part and the oblique lower part. Also,
A spring (not shown) is provided between the fixed bracket 4 and the pre-bracket 6 to bias the pre-bracket 6 toward the fixed bracket 4. Further, a cam roller 6k is attached to a base end of the pre-bracket 6 by a support arm 6x, and a plate provided at a tip of a cam driver 8 of an upper die (not shown) capable of moving the cam roller 6k up and down. It can move following the cam 8k. A hem blade (not shown) is also mounted on the upper die at a predetermined position.

In order to perform hemming of the workpiece w by the hemming apparatus 1, the workpiece w is set on the receiving surface 3u of the lower die 3 in a predetermined manner, and the upper die is lowered. In the process of lowering the upper die, first, the left inclined surface 8f of the plate cam 8k contacts the cam roller 6k, and the cam roller 6k follows the left inclined surface 8f. As a result, the cam roller 6k advances (moves leftward in the drawing) by an amount corresponding to the inclination of the left inclined surface 8f, and the cam roller 6k moves forward.
As k advances, the pre-bracket 6 and the pre-blade 6
s moves forward following the locus of a predetermined curvature (see the arrow T in FIG. 8) by the action of the link mechanism 5. Then, the flange wf of the work w set on the receiving surface 3u of the lower die 3 is folded inward by the forming surface 6f of the pre-blade 6s. When the flange wf of the workpiece w is turned back by about 45 ° by the pre-blade 6s, the pre-bending process is completed, and the cam roller 6k is returned to the original position while following the upper inclined surface 8u. Next, when the upper hem blade (not shown) presses the flange wf, the flange wf is further moved from the position by about 45 degrees.
° Bending is completed by hemming.

[0005]

However, according to the hemming apparatus 1 described above, the pre-blade 6s is not
As shown in FIG. 5, while the link mechanism 5 moves along a locus (arrow T) having a predetermined curvature, the tip of the flange wf has a radius defined by the width of the flange wf about the bending reference point ws. Move following the arc E (see dashed line). That is, bending starts (see the solid line in FIG. 8A).
If the point at which the forming surface 6f of the pre-blade 6s abuts on the tip of the flange wf is α, the point α on the pre-blade 6s moves to the point β at the end of bending, and the tip of the flange wf is at the point α. To the point γ. Thus, both 6s, w
Due to the different movement locus of f, friction occurs between the forming surface 6f of the pre-blade 6s and the tip of the flange wf,
Over time, the molding surface 6f wears and dents and the like are formed. When a dent or the like is formed on the molding surface 6f, the tip of the flange wf may be caught in the dent during the pre-bending process, and the flange wf may buckle. The technical problem of the present invention is to reduce the abrasion of the pre-blade by reducing the friction between the forming surface of the pre-blade and the front end of the flange by moving the movement trajectory of the pre-blade closer to the movement trajectory of the flange end of the work. It is to try to make it.

[0006]

The above-mentioned object is achieved by a hemming method having the following features. That is, the invention according to claim 1 is a hemming method in which a flange formed on an edge of a pressed product is bent using a bending blade and a lower mold, wherein the bending blade is moved along a movement locus of a tip of the flange. It is characterized by being moved following.
For this reason, the bending blade is hardly rubbed at the tip of the flange, and the forming surface of the bending blade is less likely to be dented due to wear. Therefore, the trouble that the tip of the flange is caught on the forming surface of the bending blade during the pre-bending process is reduced.

According to a second aspect of the present invention, there is provided a hemming apparatus for bending a flange formed on an edge of a pressed product by using a bending blade and a lower die. It is characterized in that it is moved according to a movement locus. That is, the present invention also has the same operation and effect as the first aspect of the present invention.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A hemming method and an apparatus therefor according to a first embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a schematic view illustrating a hemming method according to the present embodiment, and FIG. 2 is a cross-sectional view of a main part of the hemming apparatus according to the present embodiment. 3 to 6 are operation diagrams showing the operation of the hemming apparatus. 1 to 6, the following description will be made with the left-right direction (front-back direction) as the X-axis direction, the direction perpendicular to the paper surface as the Y-axis direction, and the height direction as the Z-axis direction.

As shown in FIG. 2, the hemming apparatus 10 includes a lower die 13 for positioning a pressed product (hereinafter, referred to as a work w) at a processing position. The lower mold 1
3 has a receiving surface 13u on which the work w is placed on its upper end, and further has a horizontal base 13b on its lower side surface. A plate 13p is mounted on the base 13b.
A slide plate 13x is fixed on p in the X-axis direction. A front stopper 13f is positioned on the side surface of the lower mold 13 in front of the slide plate 13x, and a rear stopper 13e is positioned behind the slide plate 13x. Further, on the plate 13p, a retaining base 13k for retaining a first spring 17a and a second spring 17b to be described later is provided vertically behind the rear stopper 13e.

A slider 14s of the pre-bracket body 14 is provided on the slide plate 13x in the X-axis direction (front-back direction).
Are slidably engaged with each other. The pre-bracket body 14 is a bracket for supporting a pre-blade holder 16 described later, and includes a plate portion 14p, an inclined block 14t fixed on the plate portion 14p, and a rear tension fixed on an upper portion of the inclined block 14t. And an output block 14h. The aforementioned slider 14s is fixed to the lower surface of the plate portion 14p, and a main stopper 14x is attached to a front end (left end in the figure) of the plate portion 14p so as to face the front side stopper 13f. Further, a receiving stopper 14z for receiving the pre-blade holder 16 from below is attached to the upper surface of the front end of the plate portion 14p.

The inclined block 14t includes an inclined surface 14
A first support shaft 15a and a second support shaft 15b to which a link mechanism 15 described later is connected near the upper portion and the lower portion of k are fixed in the Y-axis direction. A first fitting 14r for holding the first spring 17a is provided behind the second support shaft 15b.
Has been fixed. Here, the first spring 17a is connected to the first bracket 14r of the inclined block 14t and the detent support 1
It is hung between the first metal fitting 13r of 3k and both
4t and 13k. Therefore, when no external force is applied to the pre-bracket body 14, the pre-bracket body 14
It has been retracted to the position of the rear stopper 13e (retraction limit position) by the spring force of 7a. Also, a first protruding block 14h of the pre-bracket body 14 has a first end at a rear end.
The cam roller 14c is mounted.

On the other hand, the cam driver 24 of the upper die 23 is provided with first plate cams 23a and 23b for displacing the first cam roller 14c in the front-rear direction (X-axis direction). The first plate cam 23a has a first left inclined surface 23e, a second left inclined surface 23 in order from the tip (lower end).
f, a vertical surface 23h, and a third right inclined surface 23j. When the upper die 23 descends, the first cam roller 14c is moved to the first left inclined surface 23e and the second left inclined surface 23e.
f, the first cam roller 14c is displaced forward (displaced leftward in the figure), and is moved to the forward limit position by following the vertical surface 23h.
By imitating 3j, it is displaced backward.

Since the first cam roller 14c is mounted on the rearwardly extending block 14h of the pre-bracket body 14, the first cam roller 14c is displaced back and forth following the first plate cams 23a and 23b of the upper die 23. As a result, the pre-bracket body 14
It moves forward on x against the spring force of the first spring 17a, or retreats under the spring force of the first spring 17a. When the first cam roller 14c is at the forward limit position, the main stopper 14x of the pre-bracket body 14 comes into contact with the front stopper 13f of the lower die 13.

A pre-blade holder 16 is connected to the pre-bracket body 14 by the link mechanism 15. The pre-blade holder 16 holds the pre-blade 1 at its tip position.
This is a holder for horizontally supporting the 6s, and is disposed between the inclined surface 14k of the pre-bracket body 14 and the lower mold 13.

The link mechanism 15 has a substantially inverted T-shaped first link mechanism.
A link block 15x and a rectangular second link block 15y are provided. Both ends of the first link block 15x are rotatably connected to a first support shaft 15a of the pre-bracket body 14 and a first support shaft 16a of the pre-blade holder 16, respectively. The T-shaped tip portion (upper end portion) of the first link block 15x is bent in a "L" shape, and the second cam roller 1
5c is mounted.

Further, a second metal fitting 15r is mounted at the position of the second cam roller 15c, and the two metal fittings 15r and 13m are attracted between the second metal fitting 15r and the second metal fitting 13m of the retaining base 13k. A second spring 17b is urged in the direction. Therefore, when no external force is applied to the second cam roller 15c, the second cam roller 15c is retracted to the retreat limit position (right limit position in the drawing) by the spring force of the second spring 17b.

The second link block 15y is connected to the first link block 15y.
It is positioned parallel to the link block 15x, and both ends thereof are rotatably connected to the second support shaft 15b of the pre-bracket body 14 and the second support shaft 16b of the pre-blade holder 16, respectively. As described above, the pre-blade holder 16 includes the link mechanism 15, the first support shafts 15a, 16a.
And the pre-blade holder 16 is connected to the pre-bracket body 14 by the second support shafts 15b and 16b.
Is moved forward / backward with respect to the pre-bracket body 14 following the locus of a predetermined curvature by the action of the link mechanism 15.

The cam driver 24 of the upper die 23 has a pair of second plate cams 25 for displacing the second cam roller 15c of the link mechanism 15 in the front-rear direction (X-axis direction).
a and 25b are mounted. The second plate cam 2
5a is a first left inclined curved surface 25 in order from the front end (lower end).
e, a second left inclined curved surface 25f, a vertical surface 25h, and a third right inclined surface 25j. Then, as the upper die 23 descends, the second cam roller 15c is moved to the first left inclined curved surface 2.
5e, by imitating the second left inclined curved surface 25f,
The cam roller 15c is displaced forward with respect to the pre-bracket body 14, held at the forward limit position by following the vertical surface 25h, and displaced rearward with respect to the pre-bracket body 14 by following the third right inclined surface 25j.

As described above, the second cam roller 15c is mounted on the first link block 15x, and the first link block 15x is connected to the pre-blade holder 16 via the first support shaft 16a. Have been. For this reason, the second cam roller 15c is
4, the second cam roller 15
movement of the pre-blade holder 16 via the link mechanism 15
Is transmitted to Then, the pre-blade holder 16 moves forward / backward with respect to the pre-bracket main body 14 following the locus of a predetermined curvature by the function of the link mechanism 15. The second cam roller 15c and the pre-blade holder 16 move forward against the spring force of the second spring 17b when moving forward, and return to the retreat limit position when receiving the spring force of the second spring 17b when moving backward. When the second cam roller 15c is at the forward limit position, the lower surface of the pre-blade holder 16 comes into contact with the receiving stopper 14z of the pre-bracket body 14.

Here, the timing at which the second plate cam 25a of the upper die 23 contacts the second cam roller 15c, and the first die of the upper die 23 with respect to the first cam roller 14c.
The timing at which the plate cam 23a abuts is set to be equal. For this reason, the movement start timing of the pre-bracket body 14 and the pre-blade holder 16 becomes equal. Further, the shape of the first left inclined surface 23e and the second left inclined surface 23f of the first plate cam 23a and the shape of the first left inclined surface 25e and the second left inclined surface 25f of the second plate cam 25a are the same as those of the first plate cam 25a. The pre-blade 16s mounted on the blade holder 16 is formed in a shape such that the movement locus of the pre-blade 16s is equal to the movement locus (arc E) of the front end of the flange wf of the work w. For this reason, as shown in FIG. 1, the pre-blade 16s can move along the arc E having the radius of the width of the flange wf around the reference point ws of the work w. Further, a hem blade 27 is vertically attached to the upper die 23 at a position directly above the receiving surface 13u of the lower die 13.

Next, a description will be given of the hemming method according to the present embodiment while explaining the operation of the hemming apparatus 10. First, as shown in FIG. 3, the work w is set on the receiving surface 13u of the lower die 13. At this time, the pre-bracket body 14 is held at the position of the rear stopper 13e by the spring force of the first spring 17a. Also,
The pre-blade holder 16 is held at the retreat limit position by the spring force of the second spring 17b. In this state, the upper mold 2
3 descends, as shown in FIG.
The first left inclined surface 23e of the first plate cam 23a attached to the cam driver 24 abuts against the first cam roller 14c, and the first left inclined surface 25e of the second plate cam 25a.
e comes into contact with the second cam roller 15c.

As shown in FIGS. 4 to 6, the first cam roller 14c moves from the first left inclined surface 23e to the second left inclined surface 23f of the first plate cam 23a during the lowering of the upper die 23. The pre-bracket body 14 moves forward on the slide plate 13x against the spring force of the first spring 17a. The second cam roller 15c follows the first left inclined surface 25e of the second plate cam 25a from the second left inclined surface 25f, so that the pre-blade holder 16 follows the locus of a predetermined curvature by the action of the link mechanism 15. It advances with respect to the pre-bracket body 14. As a result, the pre-blade 16s mounted on the tip of the pre-blade holder 16 moves forward along the arc E as shown in FIG. 1, and the flange wf of the workpiece w is moved by the molding surface 16f. Pressed.

Then, as shown in FIG. 2, the first cam roller 14c is connected to the vertical surface 23h of the first plate cam 23a.
Accordingly, the main stopper 14x of the pre-bracket main body 14 abuts on the front stopper 13f of the lower die 13 and is held at the forward limit position. Also, the second cam roller 1
5c follows the vertical surface 25h of the second plate cam 25a, so that the lower surface of the pre-blade holder 16 contacts the receiving stopper 14z of the pre-bracket body 14 and is held at the forward limit position. As a result, the pre-blade 16s advances to the position indicated by the two-dot chain line in FIG. 1A, and bends the flange wf of the work w inward by about 45 °, thereby completing the pre-bending process.

When the upper die 23 is further lowered from this state, the first cam roller 14c is moved to the first plate cam 23a.
Following the third right inclined surface 23j, the pre-bracket body 14 moves backward on the slide plate 13x under the spring force of the first spring 17a. Also, the second cam roller 15c follows the third right inclined surface 25j of the second plate cam 25a,
The pre-blade holder 16 retreats under the spring force of the second spring 17b. As a result, the pre-blade 16s separates from the flange wf of the work w, and the hem blade 27 attached to the upper die 23 moves the pre-bent flange wf of the work w substantially parallel to the receiving surface 13u of the lower die 13. Press until Thus, the hemming process ends.

As described above, in the hemming method according to the present embodiment, the pre-blade 16s is advanced in accordance with the tip movement locus E of the flange wf of the work w.
Is hardly rubbed by the tip of the flange wf. For this reason, the forming surface 16f of the pre-blade 16s is unlikely to have a dent due to wear, and the flange wf is formed by the flange wf during the pre-bending process.
Troubles such as buckling due to being hooked on 6f are reduced.

[Second Embodiment] Next, a hemming method and an apparatus therefor according to a second embodiment of the present invention will be described with reference to FIG. Here, FIG. 7 is a main part side view of the hemming apparatus 40 according to the present embodiment. The hemming device 40 includes a lower die 43, and a receiving surface 43u on which the work w is placed is formed on the upper end of the lower die 43. Further, a horizontal base 43b is provided on a lower side surface of the lower die 43, and the base 43b
A pair of bearing members 43j are fixed on the upper side in the Y-axis direction via a plate 43p. And the bearing member 4
A support pin 44p formed at the lower rear end of the pre-bracket body 44 is inserted through 3j. As a result, the pre-bracket main body 44 can rotate by a predetermined angle about the support pin 44p.

Also, the pre-bracket body 44 is
The plate 43p is retained by a fixed retaining frame 43k at the rear of the plate 43p by a spring 47a. For this reason,
When no external force is applied to the pre-bracket main body 44, the pre-bracket main body 44 is held at the position of the rear stopper 43e by the spring force of the first spring 47a.

Further, a cylindrical first bush 44a and a second bush 44b are fixed to an upper portion and a front portion of the pre-bracket main body 44, respectively.
a, the first pin 46a and the second pin 46b of the pre-blade holder 46 are engaged with the second bush 44b, respectively. Here, the first bush 44a, the second bush 44b
The inner diameter of the first pin 46a and the second pin 46b is set sufficiently larger than the outer diameter of the first pin 46a and the second pin 46b.
The pin 46b can move by a fixed distance along the inner wall surfaces of the first bush 44a and the second bush 44b, respectively.

The pre-blade holder 46 is a member that horizontally supports the pre-blade 46s at the tip end thereof, and has cam plates 55a, 55 attached to the upper die 53 at the upper rear thereof.
A cam roller 46c that follows 5b is mounted. Further, the pre-blade holder 46 is retained by the rear extension block 44h of the pre-bracket main body 44 by a second spring 47b. For this reason, the pre-blade holder 46
When no external force is applied to the pre-blade holder 46, the pre-blade holder 46 is held at the retreat limit position by the spring force of the second spring 47b.

On the cam plate 55a of the upper die 53, a first left inclined surface 55e, a second left inclined surface 55f, a vertical surface 55h, and a third right inclined surface 55j are formed in this order from the tip (lower end). In the process of lowering the upper mold 53, the cam roller 46c follows the first left inclined curved surface 55e and the second left inclined curved surface 55f, so that the cam roller 46c is displaced forward, and the cam roller 46c follows the vertical surface 55h. And is displaced backward by following the third right inclined surface 55j.

When the cam roller 46c is displaced forward, the pre-blade holder 46 is pressed forward by the cam roller 46c and moves forward against the spring force of the second spring 17b. The movement of the pre-blade holder 46 includes the first pin 46a, the second pin 46b, the first bush 44a, and the second pin 46a.
The pre-bracket body 44 is transmitted to the pre-bracket body 44 via a bush 44b, and the pre-bracket body 44 is also
The support pin 44p rotates forward against the spring force of a. Here, the shape of the first left inclined surface 55e and the second left inclined surface 55f of the cam plate 55a is such that the pre-blade 46s mounted on the tip of the pre-blade holder 46 has a locus equal to the movement locus of the flange tip of the work w. It is shaped so that it can move forward.

When the cam roller 46c is at the forward limit position, the pre-blade 46s and the pre-blade holder 4
6 and the pre-bracket body 44 are also held at the forward limit position. When the cam roller 46c is displaced backward,
The pre-blade 46s, the pre-blade holder 46, and the pre-bracket body 44 are returned to the retreat limit position by receiving the spring force of the second spring 17b and the first spring 47a.

Next, the hemming method according to the present embodiment will be described while explaining the operation of the hemming device 40. First, the work w is set on the receiving surface 43u of the lower die 43. At this time, the pre-bracket main body 44 is held at the position of the rear stopper 43e by the spring force of the first spring 47a. Further, the pre-blade holder 46 is held at the retreat limit position by the spring force of the second spring 17b. When the upper mold 53 is lowered in this state, the first left inclined surface 55e of the plate cam 55a attached to the upper mold 53 comes into contact with the cam roller 46c.

Then, as the upper die 53 descends, the cam roller 46c is moved by the first left inclined surface 55e of the plate cam 55a.
Following the second left inclined surface 55f, the pre-blade holder 46 moves forward against the spring force of the second spring 17b, and the pre-bracket body 44 also moves against the support pin 44p against the spring force of the first spring 47a. It turns around forward. As a result, the pre-blade 46s mounted on the tip of the pre-blade holder 46 follows the arc E, as shown in FIG. 1, and the flange wf of the work w is pressed by the molding surface 46f. .

When the cam roller 46c follows the vertical surface 55h of the plate cam 55a, the pre-bracket body 44 and the pre-blade holder 46 are held at the forward limit position, and the pre-blade 46s is moved to the position shown in FIG. The workpiece w is advanced to the position indicated by the two-dot chain line, and the flange wf of the work w is bent inward by about 45 °. Thus, the pre-bending process ends. When the upper die 53 further descends from this state, the cam roller 46c follows the third right inclined surface 55j of the plate cam 55a, and the pre-bracket body 44 and the pre-blade holder 46 reduce the spring force of the first spring 47b and the second spring 47b. Receive and retreat. Thereby, the pre-blade 46
s is separated from the flange wf of the workpiece w, and then the hem blade 57 of the upper die 53 presses the flange wf of the pre-bent workpiece w to complete the hemming.

Thus, in the hemming method according to the present embodiment, similarly to the first embodiment, the pre-blade 4 is used.
Since 6s is moved forward along the movement path of the tip of the flange wf of the work w, the forming surface 46f of the pre-blade 46s is not rubbed by the tip of the flange wf. Further, since the structure of the apparatus is simpler than that of the hemming apparatus 10 according to the first embodiment, the apparatus can be made compact and the cost can be reduced.

Although the embodiments of the present invention have been described above, it is to be understood that the embodiments of the present invention have the following technical matters in addition to the technical matters described in the claims. Please note. (1) The hemming apparatus according to claim 2, wherein the bending blade is driven by a cam mechanism.

[0038]

According to the present invention, since the bending blade is no longer rubbed by the tip of the flange, no dent or the like is formed on the forming surface of the bending blade with the passage of time, and the tip of the flange is formed during the bending process. There is no trouble such as buckling due to being caught on the surface.

[Brief description of the drawings]

FIG. 1 is a processing diagram showing a hemming processing method according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a main part of the hemming apparatus according to the first embodiment of the present invention.

FIG. 3 is a longitudinal sectional view illustrating an operation of the hemming apparatus according to the first embodiment of the present invention.

FIG. 4 is a longitudinal sectional view illustrating an operation of the hemming apparatus according to the first embodiment of the present invention.

FIG. 5 is a longitudinal sectional view illustrating an operation of the hemming apparatus according to the first embodiment of the present invention.

FIG. 6 is a longitudinal sectional view illustrating an operation of the hemming apparatus according to the first embodiment of the present invention.

FIG. 7 is a longitudinal sectional view illustrating an operation of a hemming apparatus according to a second embodiment of the present invention.

FIG. 8 is a processing diagram showing a conventional hemming processing method.

FIG. 9 is a vertical sectional view of a main part of a conventional hemming apparatus.

[Explanation of symbols]

 w Work (pressed product) wf Flange 13 Lower die 14c First cam roller (cam mechanism) 15c Second cam roller (cam mechanism) 16s Pre-blade (bending blade) 23a First plate cam (cam mechanism) 25a Second plate cam (cam) mechanism)

Claims (2)

[Claims] 1. A hemming method for bending a flange formed on an edge of a pressed product using a bending blade and a lower die, wherein the bending blade is moved along a movement locus of a tip of the flange. Characteristic hemming processing method. 2. A hemming apparatus for bending a flange formed at an edge of a pressed product using a bending blade and a lower die, wherein the bending blade is moved along a movement locus of a tip of the flange. Characteristic hemming equipment.