JP2002018529A - Method and apparatus for bending - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constantly bend a flange including its bent part in high quality when bending the flange bent to a dog-legged shape of a work with using a pair of tools. SOLUTION: In a method, by which a first flange part 3a and a second flange part 3b continuing to a dog-legged shape of a bending flange 3 of a work 1 are bent with a first/second tools 6a, 6b respectively oscillating/ advancing from the orthogonal direction, when both tools 6a, 6b are most advanced to bend a bending flange, the tools are set to adjoin it without clearance to directly press a bending part 3c of the bending flange 3, bending is conducted, retreating of both tools to a prescribed waiting position apart from the work 1 is conducted in the order not interfering with each other, further, the tools from a waiting position up to a most advanced position of bending are advanced in the order opposite to the retreating so as not to mutually interfere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for bending (hemming) a flange, which is bent around the periphery of a work such as a sheet metal panel, at a predetermined angle with a tool.

[0002]

2. Description of the Related Art When the outer panel of an automobile door and the inner panel are joined by a hemming process, a flange bent at a substantially right angle to a peripheral portion of a work of the outer panel is formed with a pre-hem blade (pre-blade) if necessary. Pre-bending (pre-bending) back and forth, then hem-bending (main bending) with a hem blade, and pressure-bonded to the peripheral portion of the inner panel. Tools used for workpiece bending, such as pre-hem blades and hem blades, are divided into multiple parts corresponding to the bent shape when the flange of the workpiece bends in the flange length direction. The tool is independently and synchronously rocked back and forth to bend the bent flange.

For example, FIG. 3A shows a work 1 to be hemmed. The work 1 corresponds to the outer panel, and has a substantially concave bent concave portion 2 on a peripheral portion thereof.
A bent flange 3 is bent substantially at right angles on the two sides of the U-shape. The bent flange 3 is a bent portion 3 bent at an obtuse angle.
c, a first flange portion 3a on one side and a second flange portion 3b on the other side. First and second flange portions 3a, 3b
Is almost linear. When the entire bent flange 3 is pre-bent to the work 1 at a constant angle of about 45 ° as shown in FIG. 3B, for example, the first flange portion 3a and the second
A pair of prehem blades of a specific tool is pressed against each outer surface of the flange portion 3b, and each flange portion 3 is
a and 3b are simultaneously pushed and bent toward the work 1.

FIG. 4 shows a pair of first and second prehem blades 4a,
4b shows a cross section of FIG. As shown in FIG. 4 (A), the pair of prehem blades 4a and 4b swing forward from a standby position at a predetermined separation distance from the corresponding flange portions 3a and 3b with a predetermined trajectory, and the outer surfaces of the flange portions 3a and 3b. 4B, and is swung forward so as to rotate as it is, and the flange portions 3a and 3b are bent at a predetermined angle toward the work 1 as shown in FIG. When the flange bending is completed, each of the prehem blades 4a and 4b retreats to the standby position on the reverse trajectory. The work 1 shown in FIG. 4 is an outer panel that is positioned and held on the lower die 5 and is bent by the first and second prehem blades 4a and 4b. (B) is arranged, and the hem is bent after the pre-bending of the flange 4 so that the flange 4 is joined to the periphery of the inner panel.

[0005]

SUMMARY OF THE INVENTION The pair of first and second pairs
The prehem blades 4a, 4b are block bodies having a length corresponding to the length of the linear portions of the corresponding first and second flange portions 3a, 3b, each of which swings in the directions of two arrows in FIG. It moves forward and retreats in the same direction in the opposite direction. The longitudinal movement direction of each of the prehem blades 4a, 4b corresponds to the corresponding two flange portions 3.
a, 3b, and the angle formed by these two directions is α, which is the same as the angle formed by the first flange portion 3a and the second flange portion 3b of the bent flange 3. Here, when the pair of prehem blades 4a and 4b swing forward from the standby position and are at the bending final position where the bending flange 3 is pre-bent, as shown in FIG. If the lengths of both prehem blades 4a, 4b are set so that the contact final bending distance g 'between them becomes zero, the respective prehem blades 4a, 4b form an angle α with each other after bending. When retreating simultaneously or sequentially in different directions, it cannot interfere with the other party and cannot retreat.
For example, even if the second prehem blade 4b in FIG. 5 attempts to retreat to the position shown by the dashed line in FIG. 5, the first prehem blade 4a cannot obstruct the retraction, and the same occurs in the first prehem blade 4a. Also, when the prehem blades 4a and 4b are swung forward from the standby position to the bending final position shown by the solid line in FIG.

Therefore, in the current prehem device,
As shown in FIG. 6 (A), when the pair of prehem blades 4a and 4b are at the standby position, they are brought into contact with each other so that the interval between the standby positions becomes zero. In this case, when the two prehem blades 4a and 4b advance, they advance in the direction in which they spread at an angle α, so that the corresponding flange portions 3a and 3b are pre-bent in the manner shown in FIG. 4 without interfering with each other.
Also, after the pre-bending operation, when the two prehem blades 4a and 4b are retracted, they retreat without interfering with each other and return to the original standby position.

[0007] However, in the case of FIG.
When a and b are advanced in the direction of spreading at the angle α and moved to the final bending position, a certain gap g is generated between them as shown in FIG. 6B. The gap g has a size proportional to the advance distance and the angle α of the two prehem blades 4a and 4b, and the bent portion 3c of the bent flange 3 viewed from the gap g does not directly contact the two prehem blades 4a and 4b. Becomes Therefore, the bent portion 3c of the bent flange 3 is
The first and second flange portions 3a and 3b, which are directly pressed and bent by the prehem blades 4a and 4b, are bent so as to follow the bending of the first and second flange portions 3a and 3b, and the bent portion 3c is originally difficult to be bent. Because of the bent portion, the pre-bending quality of the bent portion 3c is not stable, and this may lead to a decrease in the pre-bending quality of the entire bending flange 3.

[0008] An object of the present invention is to provide a bending method capable of always bending a bent portion of a flange with high quality when a bent flange of the work is bent using a pair of tools. Is to do.

[0009]

A bending method for achieving the above object of the present invention comprises a first flange portion on one side and a second flange portion on the other side from a bent portion of a bent flange of a work which is bent substantially in a letter shape. A method for bending a workpiece by pressing a flange portion with a first tool and a second tool that swing forward from directions substantially orthogonal to the respective flange portions, wherein the first tool and the second tool When the entire bending flange is bent to the final angle, the two tools are immediately adjacent to each other without any gap so as to directly contact and press the entirety including the bending portion of the bending flange, and from the bending final position, Corresponding first and second
It is characterized in that the flange portion is moved forward and backward sequentially between a standby position in which the flange portion is retracted and stopped rearward without interfering with each other substantially orthogonally.

Here, the first tool and the second tool are a pre-hem blade, a hem blade, and the like. When the two tools are at the final bending position, the two tools are in contact with each other and are adjacent to the bent flange of the work. The whole including the bent portion is bent to the final angle. The trajectory of the two tools retreating from the bending final position to the standby position and the trajectory of moving forward from the standby position to the bending final position are set to be the same, and the two tools sequentially advance without interfering with each other,
Retreat in order. The first tool and the second tool are naturally separated from each other at the standby position, and are in different angular postures so as not to interfere with each other.

In the bending apparatus according to the present invention, the first tool and the second tool may directly contact and press the entire bent portion of the bent flange when the entire bent flange is bent to the final angle. It is characterized by having. That is,
By moving the first tool and the second tool forward and backward so as not to interfere with each other, the two tools can be adjacent to each other without any gap at the bending final position. At the final position, the extended ends which are adjacent to each other without any gap are formed, and the bent portion of the bent flange is also pressed directly by both tools and bent.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bent flange 3 of a work 1 shown in FIG.
An embodiment of pre-bending will be described with reference to FIGS. 1 (A) to 1 (C) show a pre-hem blade swinging forward process until the bending flange 3 is pre-bent by a pair of tools, a first and a second pre-hem blade 6a, 6b.
FIGS. 2A to 2C show a process of retreating the swing of the prehem blade from the end of the pre-bending. 1 (C) and FIG. 2 (A)
Indicate the same state.

In the method of the present invention, FIGS.
As shown in (A), when the first prehem blade 6a and the second prehem blade 6b pre-bend the bent flange 3, the two prehem blades 6a and 6b are set to be adjacent to each other without a gap, and each prehem blade is set. 6a and 6b are bent at the final bending position without a gap, and the first and second flange portions 3a,
Swing forward and swing back in order between a standby position (fixed position in FIG. 1A and FIG. 2C) in which the back is stopped backward without interfering with each other substantially orthogonal to 3b. . Further, in the apparatus of the present invention, the extended ends 6a ', 6b each having an adjacent side end extended from the prehem blade shown in FIG. 6 so that the two prehem blades 6a, 6b are adjacent to each other without any gap at the bending final position. '
Provided at the extension ends 6a 'and 6b'.
Is directly pressed and pre-bent.

The pair of prehem blades 6a and 6b are moved forward and backward in order so as to move back and forth without interfering with each other. Further, the posture of the two at the standby position and the angle with respect to the workpiece 1 are made different. For example, after the second prehem blade 6b is advanced first, the first prehem blade 6a is advanced to pre-bend the bent flange 3, and after the pre-bending, the first prehem blade 6a is first retracted in the reverse order, and then The second prehem blade 6b is retracted at a small inclination angle (the inclination is, for example, 12 degrees upward from horizontal) different from the first prehem blade 6a (the inclination is, for example, upwards from horizontal 20 °). This operation sequence is shown in FIG. 1 and FIG.

FIG. 1A shows a state before the pre-bending process, in which a pair of prehem blades 6
a and 6b are positioned at the respective standby positions.
At the standby position, the prehem blades 6a, 6b are separated from the outer surfaces of the corresponding flange portions 3a, 3b of the work 1 by a desired distance and in an obliquely upward posture, and the first prehem blade 6a
Is set larger than the second prehem blade 6b, and the extended end 6a 'of the first prehem blade 6a is
It is located above the extension end 6b 'of the prehem blade 6b. In this state, first, the second prehem blade 6b swings forward from a substantially orthogonal direction toward the corresponding second flange portion 3b, and pre-bends the second flange portion 3b as shown in FIG. 1 (B). When the second prehem blade 6b swings forward,
The extension end 6b 'moves forward along an arc trajectory without interfering below the extension end 6a' of the first prehem blade 6a at the standby position. The second flange portion 3b is pre-bent by the swing advance of the second prehem blade 6b, and the other first flange portion 3a is bent.
Is left unpre-bent, and the bent portion 3c is pressed by the extended end 6b 'of the second prehem blade 6b, and is about half pre-bent.

When the swinging advance of the second prehem blade 6b is completed, the first prehem blade 6a is switched to the second prehem blade 6b at the timing of the end of the advance or at a preset timing immediately before or immediately after the end of the advance. The swing advance is started in the direction of the angle α with the advance direction. The first pre-hem blade 6a swings forward from a substantially orthogonal direction toward the corresponding first flange portion 3a, and pre-bends the first flange portion 3a as shown in FIG. When the first prehem blade 6a swings forward, the extension end 6a 'interferes with the end face of the extension end 6b' from directly above the extension end 6b 'of the second prehem blade 6b at the bending final position. It is performed by moving along the arc trajectory without
At the time of the most forward movement, the end faces of the two prehem blades 6a and 6b are adjacent to each other without any gap. The first prehem blade 6a leaves the first
When the flange portion 3a is pre-bent, the entire length of the bent flange 3 is pre-bent at a predetermined angle. Bending flange 3
Bent portion 3c is an extended end 6 of both prehem blades 6a, 6b.
a ', 6b' directly presses and pre-bends,
The bent portion 3c is also pre-bent with stable quality (shape, appearance, etc.).

FIGS. 1C and 2 after pre-bending is completed.
From the state of (A), the respective prehem blades 6a, 6b retreat in the reverse order of the forward movement and follow the same trajectory as the forward movement and return to the standby position. First, as shown in FIG. 2B, the first prehem blade 6a
Swings back to the original standby position, and at this time, the extension end 6
a 'is the extended end 6 of the second prehem blade 6b at the bending end position
It retreats along the locus of an arc that does not interfere directly above b '. Next, as shown in FIG.
b moves back and forth, and at this time, the extended end 6b 'moves backward so as to dive under the extended end 6a' of the first prehem blade 6a at the standby position, and the second prehem blade 6b returns to the original standby position. Return.

Although the above embodiment has been described with reference to the pre-bending process of a work such as an outer panel of an automobile door, the present invention can be effectively applied to a case where a hem is bent with a hem blade.

[0019]

According to the present invention, when the entire bent flange of the work is bent, the bent portion of the flange is also directly pressed by a pair of tools to be bent, so that the bent flange is bent. Product quality can be improved. Also,
A pair of tools that bend the left and right sides of the bent part of the bent flange are advanced in order to bend the flange, and then retracted in order to return to the standby position before bending, so one tool must be used. It can be driven back and forth without interfering with each other, and the workpiece can be bent in a stable operation.

[Brief description of the drawings]

FIGS. 1A and 1B are a partial plan view and a partial cross-sectional view of a bending apparatus in each operation state showing an embodiment of the method of the present invention, wherein FIG. 1A is a tool standby position before a bending operation, and FIG. , (C)
Indicates the bending final position after the tool is advanced.

FIGS. 2A and 2B are a partial plan view and a partial cross-sectional view showing each operation state after bending of the bending device, wherein FIG. 2A is a final bending position of the tool, FIG. This shows the standby position after the tool is retracted.

FIG. 3A is a perspective view of a work to be bent;
(B) is a perspective view of the bent workpiece.

FIG. 4A is a cross-sectional view of a tool and a workpiece before bending.
(B) is a sectional view at the time of bending.

FIG. 5 is a plan view showing an example of an arrangement relationship between a workpiece and a tool to be bent.

6A and 6B are a partial plan view and a partial cross-sectional view showing each operation state of a bending apparatus according to a conventional bending method, wherein FIG. 6A is a standby position of a tool before bending, and FIG. Indicates the final position.

[Explanation of symbols]

 Reference Signs List 1 work 3 bent flange 3a first flange portion 3b second flange portion 3c bent portion 6a first tool (prehem blade) 6a 'extended end 6b second tool (prehem blade) 6b' extended end

Claims (2)

[Claims] 1. A first flange part on one side and a second flange part on the other side from a bent portion of a bent flange of a work bent substantially in a letter shape.
A method for bending a workpiece by pressing a flange portion with a first tool and a second tool that swing forward from directions substantially orthogonal to the respective flange portions, wherein the first tool and the second tool are provided. When the entire bending flange is bent to the final angle, the two tools are immediately adjacent to each other without any gap so as to directly contact and press the entirety including the bending portion of the bending flange, and from the bending final position, A bending method comprising sequentially advancing and retreating between a corresponding first and second flange portion and a standby position in which the first and second flange portions are retracted and stopped rearward without interfering with each other substantially orthogonally. 2. A first flange portion on one side and a second flange portion on the other side from a bent portion of a bent flange of the work which is bent in a substantially rectangular shape.
A processing apparatus for bending a workpiece by pressing a flange portion with a first tool and a second tool that swing forward from directions substantially orthogonal to the respective flange portions, wherein the first tool and the second tool are bent. A bending apparatus, wherein the tool has an extended end portion that directly contacts and presses the entire bent portion of the bent flange when the entire bent flange is bent to the final angle.