JP2002035839A - Inverse bending press die and inverse bending method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a die structure forming an inverse portion in a flanged portion of plate material. SOLUTION: In the plate material W setting in a die B for inverse bending, the flanged portion Wf is bent in right angles in advance in a right angle bending process as a previous process, and a recessed groove Wg is also cut in a portion becoming a ridge portion in the inner face of the flanged portion when inverse bending is performed. Consequently, an inverse portion Wi, in which the recessed groove Wg becomes a ridge line, can be easily bent so that a tip side of the flanged portion Wf is only pushed from its outward periphery by an inverse bending die 17 in an inverse bending process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverse bending press die and an inverse bending method for directly bending a flange portion on a sheet material and further bending an inverse portion on the flange portion.

[0002]

2. Description of the Related Art Heretofore, when an inverse portion is formed at the front end side of a flange portion formed by directly bending a plate material, a so-called double cam mechanism is often used.

A press die for performing inverse processing on a plate material as described above is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-418, which will be described with reference to FIGS.

The inverse bending press shown in FIG. 5 is a so-called single-acting press, and when not in operation, is supported by the upper die main body 2 connected to a ram (not shown) and the upper die main body 2. The pressing member 3, the cam drive 6, and the bending blade 7 are at the upper limit position, and the cam slide block 4 provided on the lower die body 11 is moved leftward in the figure by the urging force of an elastic body (not shown). Has been retracted to the standby position.

In this state, after the plate material W (see FIG. 4 (a)) cut into a predetermined shape is placed on the lower die body 11, the ram is lowered by driving a ram (not shown).
First, the holding member 3 comes into contact with the upper surface of the plate material W, and the plate material W is held in cooperation with the lower die body 11.

When the upper mold body 2 is further lowered, the first cam surface 6a of the cam drive 6 comes into sliding contact with the cam surface 4a of the cam slide block 4, and the cam slide 6 moves with the lowering operation of the upper mold body 2. The block 4 is advanced rightward in the figure, and reaches the advance limit at a position where the cam surface 6a has passed the cam surface 4a.

Subsequently, the bending blade 7 comes into contact with the front end side of the plate material W, and when the upper die body 2 is lowered, this front end portion is bent at a right angle to form a flange portion Wf (see FIG. 4B).

Thereafter, the second cam surface 6b formed on the cam drive 6 comes into sliding contact with the cam surface 5a of the inverse bending die 5 mounted on the cam slide block 4,
The inverse bending die 5 is advanced in the left direction in the drawing, that is, in a direction approaching the flange portion Wf.

Then, the cam surface 5b formed on the upper part of the inverse bending die 5 comes into contact with the cam surface 7b formed on the bending blade 7, and the bending blade 7 resists the urging force of the elastic body 7a. And raise the bending blade 7 with the inverse bending die 5
From the stroke area. At this time, the bending blade 7
Is located above the flange portion Wf, and functions as a suppressing member for holding the flange portion Wf together with the cam slide block 4.

When the inverse bending die 5 further advances, the inverse bending die 5 pushes the distal end side of the flange portion Wf in the direction of the inclined surface 4b formed on the cam slide block 4 to form the inverse bending die 5. The pressure is sandwiched between the cam slide block 4 and the inclined surfaces 5c and 4b to form an inverse portion Wi (see FIG. 4C).

[0011]

However, in the conventional inverse bending press described above, the flange W
When the inverse portion Wi is formed in f, the cam slide block 4 and the inverse bending die 5 are slid using a cam mechanism and pressed between the inclined surfaces 4c and 5b provided on the two members 4 and 5. Since the so-called double cam mechanism is used, there is a problem that the structure of the mold is complicated.

In view of the above circumstances, it is an object of the present invention to provide an inverse bending press die and an inverse bending method capable of forming an inverse portion with a simple structure without using a so-called double cam mechanism. I do.

[0013]

In order to achieve the above object, an inverse bending press die according to the present invention comprises a straight bending die for bending a plate material to form a flange portion and an inverse bending die for bending the inverse portion to the flange portion. A bending mold, wherein the straight bending mold has a first
A lower mold body having a surface and a second surface intersecting the first surface;
A holding member that holds the plate material placed on the first surface in cooperation with the lower mold body, and a third surface that can face the second lower surface of the lower mold body in a substantially parallel state. A second body provided on the lower mold body by the upper mold body moving relative to the lower mold body; and a third surface provided on the upper mold body. In the above-mentioned plate material, a flange portion is formed by direct bending, while the inverse bending mold presses the flange portion from a direction substantially perpendicular to the holding means for holding the plate material, and forms an inverse portion on the tip side of the flange portion. In an inverse bending press die having an inverse bending die to be formed by bending, a ridge portion is provided on the second surface along a ridge line between the flange portion and the inverse portion.

In such a configuration, when the flange portion is formed by bending the plate member directly on the second surface provided on the lower mold body and the third surface provided on the upper mold body, the second surface is formed. A groove is formed on the ridgeline of the inverse portion formed by post-processing on the inner surface of the flange portion by the ridge portion provided in the flange portion, and when the inverse bending is performed using the inverse bending mold, the inverse groove is formed. The inverse portion can be formed with the concave groove as a ridge line simply by pressing the front end side of the flange portion from the outside by the bending mold.

In this case, preferably, 1) the ridge portion is projected from the second surface in a range of 0.9 to 0.6 times the thickness of the plate material. 2) The ridge is formed in a substantially inverted V-shaped cross section.

The inverse bending method according to the present invention comprises:
A step of forming a flange portion directly on a plate material, a step of forming a concave groove in a portion that becomes a ridgeline during the inverse bending formation on the inner surface side of the flange portion, and a process of pressing an outer surface of the flange portion to form a tip of the flange portion. A step of bending an inverse portion having the concave groove as a ridgeline on the side.

In such a configuration, after the flange portion is formed by bending the plate material directly, a concave groove is formed in a portion which becomes a ridgeline at the time of the inverse bending on the inner surface side of the flange portion, and then the outer surface of the flange portion is pressed. An inverse portion having a concave groove as a ridgeline is formed at the front end side of the flange portion by bending.

In this case, preferably, 1) the groove depth of the concave groove is about 0.7 times the thickness of the plate material. 2) The groove has a substantially V-shaped cross section.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is an enlarged cross-sectional view of a main part of a straight bending die, FIG. 2 is an enlarged view of a plate material that is directly bent, and FIG. 3 is an enlarged cross-sectional view of a main part of an inverse bending die.

The inverse bending press die shown in the present embodiment includes a direct bending die A and an inverse bending die B, and each of the dies A and B exchanges the dies with one press machine. By doing so, they may be shared, or may be constituted by individually independent presses.

As shown in FIG. 1, a direct bending die A includes a lower die body 11, a holding member 12 facing above the lower die body 11, and an upper part disposed substantially parallel to the holding member 12. And a mold body 13.

The lower die body 11 is provided with a first
A top surface 11a, which is a surface, and a second surface orthogonal to the top surface 11a.
And a vertical wall surface 11b which is a surface. The plate material W is a thin steel plate cut into a predetermined shape, and is used, for example, as a panel component of a vehicle.

The holding member 12 is connected to a ram (not shown) via an elastic body.
The plate material W which is close to the top surface 11a of the lower mold body 11 and is placed on the top surface 11a is pinched and held in cooperation with the lower mold body 11.

The upper die body 13 operates integrally with a ram (not shown), and has a lower pressing surface as a third surface which is substantially parallel to the vertical wall surface 11b of the lower die body 11. A punch 14 having a sheet material W is provided between the pressing surface 14a and the vertical wall surface 11b of the lower die body 11.
The tip of is bent and formed with a pressure.

The vertical wall surface 11 provided on the lower die body 11
b, a groove forming die 15 formed of a tool steel material or the like is parallel to the ridge portion between the top surface 11a and the vertical wall surface 11b, that is, from the near side to the far side of FIG. The groove 15 is formed horizontally, and a protrusion 15 a is formed on the groove forming die 15 along the extending direction of the die 15. The ridge 15a is for engraving a concave groove Wg on the back surface of the flange portion Wf formed by the direct bending of the plate material W, and has a substantially inverted V-shaped cross section.

The concave groove Wg gives a bend for forming the inverse portion Wi on the front end side of the flange portion Wf. The inverse portion Wi is bent with the concave groove Wg as a ridge line.

As shown in FIG. 2, according to the experiment, the groove Wg
Is preferably about 0.7 times the plate thickness t1 of the plate material W.
By setting it to be seven times, it is possible to obtain a good start of inverse bending with an external pressing force while maintaining strength.

In the present embodiment, the groove depth t2 of the concave groove Wg
Is set to about 0.7 times the plate thickness t1 of the plate material W, the protrusion height h of the ridge portion 15a formed on the groove forming die 15 is set to 0.6 to 0. It is formed in a range of 9 times.

As shown in FIG. 3, an inverse bending die B is a direct bending die A, which is formed by bending an inverse portion Wi at a tip end side of a flange portion Wf formed by bending a plate material W. , Holding means 16 and inverse bending mold 17.

The holding means 16 has a fixed holding member 16a and a movable holding member 16b. Movable restraining member 16b
Is connected to a ram (not shown) via an elastic body,
Due to the lowering operation of the ram, the non-processed portion Wo of the plate W placed close to the top surface of the fixed holding member 16a and placed on this top surface
Is pressed and held in cooperation with the fixed holding member 16a.

The inverse bending mold 17 engages with a cam vertically provided on a ram (not shown) so as to approach the vertical wall surface of the fixed holding member 16a from a direction substantially perpendicular to the lowering operation of the ram. , And an inverse bending blade 18 is fixed to the forward end thereof.

The inverse bending blade 18 has an inclined surface 18a formed on the top surface of the distal end of the flange portion Wf of the plate W for bending the inverse portion Wi at a predetermined angle.

The holding means 16 positions the non-processed portion Wo of the plate material W at least slightly beyond the horizontal length L of the inverse portion Wi, as shown in FIG. 3B. Is done.

Next, the operation of the present embodiment having the above configuration will be described. In the straight bending die A shown in FIG. 1, a ram (not shown) is in a raised position in a standby state, and the holding member 12 and the upper die body 13 connected to the ram are raised to predetermined positions. .

In this state, the top surface 11a of the lower die body 11
A plate material W cut in a predetermined shape in advance is placed. At this time, the distal end portion of the plate material W where the flange portion Wf is formed to bend protrudes from the vertical wall surface 11b of the lower die body 11 by a predetermined amount.

When the ram descends, the holding member 12 first comes into contact with the upper surface of the plate material W placed on the top surface 11a of the lower die body 11, and this plate material W is moved to the lower die body 11
And cooperate with to hold. Since an elastic body is interposed between the ram and the holding member 12, the lowering operation of the holding member 12 stops here.

Next, the upper die body 13 which operates integrally with the ram is lowered, and a punch 14 provided below the upper die body 13 is provided.
Abuts on the tip end protruding horizontally from the lower die body 11 of the plate material W, and causes the tip end to bend downward.

Thereafter, when the pressing surface 14a of the punch 14 is opposed to the vertical wall surface 11b of the lower die body 11, the front end portion of the plate material W is narrowly pressed between the pressing surface 14a and the vertical wall surface 11b to be bent directly. Thus, a flange portion Wf is formed.

At this time, since the ridge 15a formed on the groove forming die 15 is projected from the vertical wall surface 11b, the ridge 15a is formed on the rear surface of the flange Wf by the ridge 15a.
A concave groove Wg having a substantially V-shaped cross section is formed in parallel with the ridge line of the flange portion Wf.

The protrusion height h of the ridge 15a is set to a value such that the groove depth t2 of the concave groove Wg formed in the flange Wf is 0.7 times the plate thickness t1 of the plate material W. In the present embodiment, the protrusion height h is set to 0.6 to less than the plate thickness t1 of the plate material W.
The range is set to 0.9 times.

When the ram reaches the lowering limit and the straight bending of the plate material W is completed, the ram starts to ascend, the upper die body 13 integrally operating with the ram is separated from the lower die body 11, and the flange portion Wf Release the narrow pressure. Next, the holding member 12 is separated from the top surface 11a of the lower die body 11, and the plate material W
Is released, the mold can be released, and eventually the ram reaches the upper limit and the straight bending process is completed.

Next, the plate material W that has been subjected to the direct bending process is taken out of the direct bending die A, and the inverse bending die B
Set to.

In the inverse bending die B shown in FIG. 3, the ram (not shown) is in the raised position in the standby state.
A movable restraining member 16b suspended from the ram faces above the fixed restraining member 16a. The inverse bending die 17 is retracted to the right in FIG. 3A under the urging force of an elastic body (not shown).

In this state, the non-processed portion Wo of the plate W is placed on the fixed holding member 16a. At this time, the flange portion Wf on the distal end side is set so as to protrude by a set amount.

When the ram descends, first, the movable holding member 16b comes into contact with the upper surface of the non-working portion Wo of the plate W placed on the fixed holding member 16a, and presses the non-working portion Wo. And cooperate with the fixing holding member 16a to hold and press. Since an elastic body (not shown) is interposed between the ram and the movable holding member 16b, the lowering operation of the movable holding member 16b stops here.

Then, as the ram is lowered, a cam (not shown) which operates integrally with the ram is lowered, and its cam surface is formed on a cam surface (both not shown) formed on the back surface of the inverse bending die 17. When sliding, the inverse bending mold 17 is
It is pressed in the left horizontal direction in FIG.

Then, the inverse bending die 17 moves forward in the left horizontal direction, that is, in a direction substantially perpendicular to the flange portion Wf, against the urging force of the elastic body (not shown), and is provided at the distal end thereof. The inverse bending blade 18 comes into contact with the distal end side of the flange portion Wf which is formed by bending the plate material W directly. Press in the direction of the vertical wall.

Then, a concave groove W is formed on the inner surface of the flange portion Wf.
Since g is engraved, the concave groove Wf provides a start for inverse bending, and the front end of the flange portion Wf is bent inward with the concave groove Wf as a ridge line.

The groove depth t2 of the concave groove Wf is a value capable of obtaining a good start of the inverse bending with an external pressing force while maintaining the strength. The thickness is set to about 0.7 times the plate thickness t1.

When the inverse bending die 17 reaches the forward limit, as shown in FIG. 3 (b), the inverse bending die 17 moves along the inclined surface 18a formed on the upper surface of the inverse bending blade 18 toward the tip end of the flange portion Wf. The portion Wi is formed by bending.

Thereafter, when the ram reaches the lower limit and the bending of the inverse portion Wi is completed, the ram starts to rise,
As the cam fixed to the ram rises, the pressing force on the inverse bending die 17 is gradually released, and the inverse bending die 17 receives the urging force of the elastic body (not shown), and the inverse bending die 17 receives the urging force of FIG. It retreats rightward and moves to the retreat position shown in FIG.

Next, the movable holding member 16b separates from the fixed holding member 16a, the narrow pressure of the non-processed portion Wo is released, the mold can be released, and eventually the ram reaches the upper limit.
The inverse bending process is completed.

As described above, in the present embodiment, in the straight bending step of forming the flange portion Wf, the concave groove Wg is carved in a portion that becomes a ridgeline when the inverse bending is formed. Then, the flange Wi
By simply pressing the distal end portion of the above from the outside with the inverse bending die 17, the inverse portion Wi can be easily bent and formed. Therefore, unlike the related art, it is not necessary to bend the inverse portion Wi using a so-called double cam mechanism, and the structure of the inverse bending die B can be simplified.

[0054]

As described above, according to the present invention,
The inverse portion can be bent and formed with a simple structure without using a so-called double cam mechanism, so that the structure of the inverse bending die can be simplified and the inverse portion can be easily bent.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a straight bending mold.

FIG. 2 is an enlarged view of a plate material that is bent straight.

FIG. 3 is an enlarged sectional view of a main part of an inverse bending mold.

FIG. 4 is an explanatory view showing a bending procedure of a plate material.

FIG. 5 is a sectional view of a main part showing a conventional inverse bending press die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Lower type | mold main body 11a Top surface (1st surface) 11b Vertical wall surface (2nd surface) 12 Suppression member 13 Upper type | mold main body 14a Pressurization surface (3rd surface) 15a Ridge part 16 Holding means 17 Inverse bending type A For direct bending Mold B Mold for inverse bending t1 Sheet thickness t2 Groove depth W Sheet material Wf Flange part Wg Groove groove Wi Inverse part

Continuation of front page (72) Inventor Noboru Endo 1-7-2 Nishishinjuku, Shinjuku-ku, Tokyo F-term in Fuji Heavy Industries Ltd. (reference) 4E063 AA01 BA01 BA07 KA11

Claims (6)

[Claims] 1. A direct bending die for bending a plate material to form a flange portion, and an inverse bending die for bending and forming an inverse portion on the flange portion, wherein the straight bending die is formed of the plate material. A lower die main body having a first surface to be mounted and a second surface intersecting the first surface, and a restraint for holding a plate material mounted on the first surface in cooperation with the lower die main body. A member having an upper die body having a third surface that can be opposed to the second surface of the lower die body in a state substantially parallel to the second surface of the lower die body; A flange portion is formed by bending the plate material directly with the second surface provided on the mold body and the third surface provided on the upper mold body. Holding means for holding, and pressing the flange portion from a substantially orthogonal direction to insert into the front end side of the flange portion. An inverse bending press having an inverse bending die for bending the base portion, wherein an inverse ridge portion is provided on the second surface along a ridge line between the flange portion and the inverse portion. Type. 2. An inverse bending press die according to claim 1, wherein said ridge portion projects from said second surface in a range of 0.9 to 0.6 times the thickness of said plate material. . 3. An inverse bending press die according to claim 1, wherein said ridge portion is formed in a substantially inverted V-shaped cross section. 4. A step of forming a flange portion in a plate material by direct bending, a step of forming a concave groove in a portion which becomes a ridgeline at the time of inverse bending on the inner surface side of the flange portion, and pressing an outer surface of the flange portion. A step of bending an inverse portion having the concave groove as a ridgeline at a front end side of the flange portion. 5. The groove depth of the concave groove is about 0.7 of the plate thickness of the plate material.
The inverse bending method according to claim 4, wherein the number is twice. 6. An inverse bending method according to claim 1, wherein said concave groove is formed in a substantially V-shaped cross section.