JP2003053429A - Method for bending sheet metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bending method which is simply and by which financial load is reduced even in the work of bending a sheet metal to a specific shape. SOLUTION: This method of bending the sheet metal comprises steps (1) to (3). (1) On the sheet metal which is the object of the bending work, there are provided guide protruded pieces (a) which are a pair of protruded pieces along a bending line, (b) which are formed by working the sheet metal itself, (c) which have a V-shaped guide slopes inclining downward toward the middle and are provided with protruded parts which are formed into an approximately M-shape in the cross section and in which the angle αA formed by the V-shaped guide slopes is made not less than a bending angle αθwhich is the object of the working and (d) which have supplementary dents formed for providing a material to the protruded parts. (2) The sheet metal is placed on the lower die having a V-shaped groove, an upper bending die whose tip is similarly made to coincide with the bending angle as the lower die is arranged above the sheet and the upper die is lowered. (3) The supplementary dents are filled with the protruded parts by the pressing force of the upper die and thickness is returned to the original thickness of the sheet metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bending a sheet metal, and more particularly to a method for bending a sheet metal which is accurate and has high workability.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, a sheet metal is bent by a bending machine called a press brake.
It is usual that the abutting member is brought into contact with an object to perform a bending process. However, the bending process that can be performed by the abutting member is parallel bending of a square sheet metal with which the abutting member can abut, and a rectangular diagonal line (see FIG. 1A) in which other abutting members are difficult to abut, The square diagonal line (see FIG. 1B), the elliptical center line (see FIG. 1C), etc. were very difficult to determine the bending position. In this case, (1) draw a scoring line on the sheet metal, and perform bending by aligning the scoring line with a bending die visually, or
(2) The present situation is that the abutting member is specially manufactured so that the object can be bent, and the abutting member is used for bending.

[0003]

However, depending on the above method, (1) the former method cannot perform accurate bending since it is performed by visual measurement and the error is contained within a tolerance of 0.1 mm. Not applicable to precision sheet metal, (2)
In the latter method, it is necessary to manufacture an abutting member each time, and the cost becomes enormous. (3) Both of them require a great deal of work and are unsuitable for high-mix low-volume production, and have a large economical burden. It had the difficulty of becoming a thing. The present invention is intended to solve such a problem and to develop a bending method which is simple and has a small economical burden even for bending a sheet metal having a special shape.

[0004]

A method of bending a sheet metal according to claim 1 is a method of bending a sheet metal, wherein (1) the sheet metal to be bent is selected from the following (a) to (d). Forming a guide ridge that meets the requirements, and (a) a pair of ridges facing each other around the fold line along the fold line, and (b) processing the sheet metal itself to form the ridge.
(C) A V-shaped guide slope that falls toward the center is provided, and a ridge that supports it is provided to form a ridge having a substantially M-shaped cross section, and the lower vertex of the center of the M-shape is aligned with the fold line. At the same time, the angle αA of the V-shaped guide slope is set to be equal to or larger than the bending angle αθ for the purpose of processing, and (d) the back of the ridge is formed with a complementary recess for providing a member to the ridge, (2) The sheet metal is placed on a lower die having a concave groove on the lower side of the guide ridge, and the tip is aligned with the upper die bending die, and the upper die is lowered and bent at a predetermined angle. It is characterized by.

According to a second aspect of the present invention, there is provided a method of bending a sheet metal, wherein in the sheet metal bending process, (1) the guide ridges satisfying the following requirements (a) to (d) for the sheet metal to be bent. And (a) is a pair of raised pieces facing each other along the bending line, and (b) the sheet metal itself is processed to form the rising piece, and (c) is directed toward the center. Has a V-shaped guide slope that falls down and is provided with a ridge that supports it and a ridge having a substantially M-shaped cross section is provided.
The angle αA of the V-shaped guide slope is set to be equal to or larger than the bending angle αθ for the purpose of processing, and (d) the back of the ridge is formed with a complementary recess that provides a member for the ridge, (2) the sheet metal is guided. Placed on a lower die having a V-shaped groove with an angle matching the bending angle on the lower side of the raised piece, and similarly arranging an upper die for bending with the tip matching the bending angle. The upper die is lowered, and (3) the raised portion fills the filling recess by the pressing force of the upper die to restore the original thickness of the sheet metal.

A method for bending a sheet metal according to claim 3 is
(1) The following (a) to the sheet metal to be bent are
(D) A pair of raised pieces that form guide raised pieces that meet the requirements of (d) and that face each other along the bending line (a), and that are formed by processing the sheet metal itself (b). Has a V-shaped guide slope that falls toward the center, and has a ridge that supports the slope, and has a cross section of approximately M.
A raised portion forming a V-shape is provided, the lower apex of the center of the M-shape is aligned with the bending line, and the angle αA of the V-shaped guide slope is equal to or larger than the bending angle αθ for the purpose of processing.
(D) In the rear part of the ridge, a complementary recess for providing a member to the ridge is formed. (2) The sheet metal is placed on a lower mold having a groove under the guide ridge, Further, the tip is aligned with a bending die of the upper die, and the upper die is lowered and bent at a predetermined angle.

According to a fourth aspect of the present invention, there is provided a method of bending a sheet metal, wherein in the bending process of the sheet metal, (1) the guide ridge piece satisfying the following requirements (a) to (d) is applied to the sheet metal to be bent. And (a) is a pair of raised pieces facing each other along the bending line, and (b) the sheet metal itself is processed to form the rising piece, and (c) is directed toward the center. Has a V-shaped guide slope that falls, and a ridge that supports it is provided to form a ridge having a substantially M-shaped cross-section.
The angle αA of the V-shaped guide slope is set to be equal to or larger than the bending angle αθ for the purpose of processing, (d) a supplementary recess that forms a space is formed on the outer side of the raised portion, and (2) the sheet metal is used as a guide raised portion. It is placed on a lower die having a V-shaped groove whose angle corresponds to the bending angle on the lower side of one piece, and an upper bending die whose tip matches the bending angle is placed on the lower die, and Lower the mold,
(3) It is characterized in that the raised portion fills the filling recess and restores the original thickness of the sheet metal by the pressing force of the upper mold.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION A sheet metal 1 to which the present invention is applied, as shown in FIG. 1, is a line 2 which is not parallel to each side such as a rectangle, a square, an ellipse, etc. The main target is to bend along. This is because these are sheet metals that cannot be bent by an abutting member of a normal press brake. However, the method of the present invention is
The present invention is not limited to these objects and may be applied to the case of performing parallel bending in a conventional quadrangle. The sheet metal usually refers to a metal plate having a thickness of 0.1 to 6.0 mm.
The method of the present invention is not limited to this as long as it is applicable.

With respect to these sheet metals, (a) to
The guide ridge 10 which satisfies the requirement of (d) is formed.

The requirement (a) is that a pair of raised pieces 11 facing each other along the bending line 2 and having the bending line 2 as a center.
a and 11b are required. The bending line 2 indicates a position where the target sheet metal should be bent,
In the present invention, it is not necessary to perform scoring, but the location may be set by an NCT machine to be described later. It is desirable that the raised pieces 11a and 11b are symmetrical with respect to the bending line 2 and that the bending line as the center point forms the axis of symmetry.

Next, the requirement (b) is that the sheet metal 1 itself is processed to form the raised pieces 11a and 11b, that is, the sheet processed from the other is not added to the sheet metal. As will be described later, the sheet metal is directly processed into a sheet metal by a numerically controlled turret punch press (NCT) to form protrusions and associated depressions and recesses, and the sheet metal itself is the object of processing. This is because, as will be described later, the present invention aims to fill the protrusions and the depressions and integrate them into the original state after the bending process is completed.

The requirement (c) is that the raised pieces 11a and 11b are
Is a V-shaped guide slope 13 that falls toward the center.
a and 13b, and a ridge for supporting the
Protrusions 14a and 14b having a V shape are provided, and a lower apex 12 at the center of the M shape is aligned with the folding line 2. As shown in FIG. 2, the M-shaped type may have the ridges 14a and 14b as vertical walls, but it may be an M-shaped type in which the ridges 14a and 14b are slightly slanted walls, and in that sense is "substantially" M-shaped. . Further, as shown in FIG. 5, when the target bending angle of the sheet metal is αθ, the angle αA of the V-shaped guide slope is set to be the bending angle αθ or more. Generally, the angle αB of the tip 3a of the upper mold 3 and the angle αC of the groove 4a of the lower mold 4 of the bending machine 30 such as a press brake used for bending, which will be described later, are matched with the bending angle αθ. Therefore, the angle αA formed by the two guide slopes 13a and 13b forming the central V-shape is αA> αB =
It is assumed that the relationship of αC holds. For example, αB = α
When C is 90 °, αA = 93 °. This is because the tip 3a of the upper die 3 of the bending machine 30 is brought into contact with only the lower apex 12 of the center of the M-shape that coincides with the folding line 2 so that the bending work becomes accurate.

However, it is not an absolute condition that the angle αB of the upper die 3 and the angle αC of the lower die 4 match the bending angle αθ. Even if αB and αC do not match the bending angle αθ, the press brake It is also possible to set the bending angle αθ by adjusting the position of descent.

Further, the requirement (d) is that the raised portions 14a, 14a
4b, on the back of the back, a complementary recess 16 that provides a member for the ridge.
to form a and 16b. Filling recess 16a, 1
As described in the requirement (b) above, the role of 6b is to form the ridges 14a and 14b with the sheet metal as a processing target, and thus naturally plays a role of providing a member to the ridge. Also, as another role, the filling recess 16a,
As will be described later, 16b undergoes plastic deformation when the ridges 14a and 14b are pressed by being sandwiched between the upper mold and the lower mold, and the lump of meat corresponding to the bulged part is deformed to the concave side and finally raised. All of the above are filled in the dents and play a role of returning to the original flat plate shape. In this case, it is necessary for the upper mold to be in a direction in which a force to be crushed is applied to the ridge, that is, in a rearward direction perpendicular to the fold line of the ridge, and to be a depression in which the meat mass of the ridge can be filled. The back is in a rear direction orthogonal to the bending line 2 against which the raised portions 14a and 14b are pressed.

When the above aspect is embodied, it is as shown in FIG.
The guide slopes 13a and 13b that fall inward toward the bottom of the valley extend in a semicircular shape from the lower apex 12, and the supplementary depression 16 is provided outside.
The a and 16b are engraved in an elliptical shape to form a flat egg shape. However, the above is an example, and the inner guide slopes 13a and 13b may be a quadrangle with the lower apex 12 linear rather than a semi-circle, and the supplementary depression recess 16
The a and 16b are not limited to the above, as long as the depressions are formed in the volume for supplying the thick solid portions to the raised portions 14a and 14b.
In this aspect, when the inner side of the bending process of the sheet metal is the back side and the outer side is the front side, the guide ridge 10 is formed on the back side, and therefore no scratch is left on the sheet metal surface even after the bending process. Becomes

Next, as a second embodiment, as shown in FIG. 3, the M-shape is slightly deformed to a shape close to a corrugated shape, and the first embodiment and (a) to (c) are used. Requirements are almost unchanged. The difference is that in the requirement (d), the raised portion 24
Outside the a and 24b, a complementary recess 26 that forms a raised portion
a, 26b. Filling recesses 26a, 2
6b, similar to the above, forms an outer space for forming the raised portions 24a, 24b, and when the raised portions 24a, 24b are pressed by being sandwiched between the upper die and the lower die, plastic deformation occurs, which corresponds to the raised portion. The lump of meat that is deformed is deformed toward the concave portion and returns to the original flat plate shape. Specifically, the V-shaped guide slope 2 is provided in the center with an M-shaped cross section.
3a, 23b are formed, and the raised portions 24a, 24b
The recesses 26a and 26b are formed along the outer side of the flat surface, and the plane has an oval shape in which the lower apex 22 of the bottom and the upper apices 25a and 25b are arranged in parallel lines.

The guide ridges 10 and 20 can be processed by a numerically controlled turret punch press (NCT).

Further, two or more guide ridges 10 and 20 are arranged in parallel along the bending line 2, and the number thereof is adjusted depending on the bending length and thickness of the sheet metal.

Next, in order to bend the sheet metal having the guide ridges 10 and 20 formed as described above, first, the sheet metal is V-shaped on the lower side of the bending machine 30 such as a press brake.
It is placed on the lower die 4 having the groove 4a, and the tip 3 is placed thereon.
The upper bending die 3 in which a is matched with the bending angle is arranged, and the upper die 3 is lowered.

Then, the sharp tip 3a of the upper die 3 of the bending die
Hits either one of the left and right sides of the V-shaped groove guide slopes 13a, 13b (FIG. 7 (A)), and when the upper die 3 further descends, the sharp tip 3 descends along the guide slopes 13a, 13b. . The descending force of the upper die tip 3a acts on the guide slopes 13a and 13b to work in a vector inward direction of the guide slope, that is, the sheet metal 1 is slid to the upper die tip 3a side (FIG. 7 (B)). Then, when the upper die tip 3a reaches the bottom dead center, that is, when it reaches the valley bottom, the descent is stopped. This means that the upper die tip 3a is guided to the lower apex 12 that serves as the V-shaped valley bottom of the guide piece 10. That is, the acute-angled tip 3a of the upper die 3 is guided to the V-shaped lower apex 12 of the guide ridge 10, and the upper die tip 3a and the folding line 2 are automatically and accurately aligned.

When the upper die 3 is further lowered, the tip 3 of the upper die
a and the descending apex 12 of the V-shaped groove of the guide raised piece 10,
From the side, it makes contact at one of the lowest points. The angle αA formed by the two guide slopes 13a and 13b forming the central V-shape is
Since αA> αB = αC, the upper die tip 3a of the bending machine 30 does not come into surface contact with the guide slopes 13a and 13b, and the downward pressing force of the upper die tip 3a is not dispersed. Is converted into a bending force (see FIG. 5).

When the upper die 3 reaches the bottom dead center, the upper die 3 is sandwiched between the V-shaped groove 4a of the lower die 4 and the tip 3a of the upper die, and the ridges 14a, 14b of the guide ridged piece 10 of the sheet metal. Has a crushing force (see FIG. 8D and FIGS. 6A to 6D). Furthermore, when a pressing force is applied in the direction perpendicular to the bending line 2 of the guide slopes 13a and 13b, the guide slope surface apex causes a crushing action, causing plastic deformation inside the metal, and a recess 16a formed in the rear direction of the right-angled axis. The thick portion flows into 16b (see FIG. 8 (E)). At this time, NCT from one sheet metal
Since the raised portions 14a and 14b and the complementary depressions 16a and 16b were formed by the excavating action by the machine, the volume of the raised portions and the volume of the depressed portions are the same, and all the raised portions fill up all the depressed portions, and the original flat plate. Can be returned to the shape (Fig. 8)
(See (F)). At the time of plastic deformation, internal frictional heat and component diffusion occur, which promotes thermal welding and not only regenerates them, but also promotes integration by welding and maintains physical strength as a plate.

Thus, when the bending process proceeds, the raised portion 1
4a, 14b and the compensation recesses 16a, 16b gradually overlap with each other, and when the bending is completed, the raised portions 14a, 14b fill the compensation recesses 16a, 16b, and both are integrated to return to the original sheet metal thickness.

In the case of the second embodiment, the raised portions 24a, 2a
On the outer side of 4b, there are filling recesses 26a, 26 forming ridges
b is formed, but is sandwiched between the V-shaped groove 4a of the lower die 4 and the tip 3a of the upper die, and the raised portion 24 of the guide raised piece 10 of the sheet metal is formed.
When the crushing force acts on a and 24b,
26b is crushed to return to the original flat plate-like body, and the other points are the same as in the first embodiment.

When the angle αB of the upper die 3 and the angle αC of the lower die 4 do not match the bending angle αθ, the position of the press brake is set to a predetermined distance and the descending position is set. By setting, the bending of the sheet metal can be set to a predetermined angle αθ. However, in this case, the raised portion 14a,
There is no effect that 14b fills the filling recesses 16a and 16b and the outer recesses 26a and 26b are crushed to return to the original flat plate body.

[0026]

The present invention having the above-described structure has the following excellent effects.

(A) Bending can be performed by the guide ridges formed on the sheet metal itself, and bending such as an elliptical shape or a diagonal line of a quadrangle that cannot be contacted by a conventional pad can be simply performed without using a pad. Bringing an epoch-making effect.

(B) Further, since the guide ridges are formed on the sheet metal itself, if one upper mold lower die is prepared, it is possible to cope with sheet metal of any size and adapt to small-lot production of various kinds. .

(C) Further, the guides are (a) to (d).
Since the above requirement is satisfied, positioning and the like can be accurately performed, and precision sheet metal fitting within a tolerance of 0.1 mm unit can be dealt with. (D) When the bending is completed, the protrusion fills the filling recess and the recess, and the both are integrated, so that the original thickness of the sheet metal is restored and the physical strength of the sheet metal is maintained.

[Brief description of drawings]

FIG. 1 is a plan view of a sheet metal to be processed according to the present invention.

FIG. 2 is a plan view showing a guide ridge, FIG.
(B) is a sectional view.

FIG. 3 shows another embodiment of the guide ridge, which is (A).
Is a plan view and (B) is a sectional view.

FIG. 4 is a partially enlarged side view of the guide protruding piece when the upper mold is in contact with the guide protruding piece.

FIG. 5 is a partially enlarged cross-sectional view of an upper die, a guide protrusion piece, and a lower die.

FIG. 6 is a side view showing a process of bending the sheet metal of the present invention by a bending machine, showing a process of sequentially bending the sheet metal from (A) to (D) in a time series.

FIG. 7 is a partially enlarged cross-sectional view showing a process of bending the sheet metal of the present invention by a bending machine. From (A) to (C), the tip of the upper die is aligned with the protruding piece, and the bending is started. The process of is shown in chronological order.

FIG. 8 is a partially enlarged cross-sectional view showing a process of bending the sheet metal of the present invention by a bending machine, showing a process from bending to completion in time series from (D) to (F).

FIG. 9 is a side view showing a state where a bending process is performed using a conventional butting member.

[Explanation of symbols]

1 sheet metal 2 folding lines 10 Guide ridge 11a, 11b Raised pieces 12 Lower vertex 13a, 13b Guide slope 14a, 14b Raised part 15a, 15b Upper vertex 16a, 16b hollow 20 Guide ridge 21a, 21b raised piece 22 Lower vertex 23a, 23b Guide slope 24a, 24b Raised part 25a, 25b Upper vertex 26a, 26b depression 30 bending machine 3 Upper mold 3a tip 4 Lower mold 4a groove

Claims (4)

[Claims] 1. When bending a sheet metal, (1) forming guide ridges satisfying the following requirements (a) to (d) on the sheet metal to be bent, and (a) bending line: A pair of raised pieces facing each other around the bending line, (b) a sheet metal itself is processed to form a raised piece, and (c) a V-shaped guide slope that falls toward the center. Then, a ridge for supporting it is provided to form a ridge having a substantially M-shaped cross section, the lower apex of the center of the M-shape is aligned with the bending line, and the angle αA of the V-shaped guide slope is set for the purpose of processing. A bending angle αθ or more, and (d) a backside of the raised portion is formed with a complementary recess for providing a member to the raised portion. (2) The sheet metal is a lower die having a groove on the lower side of the guide raised piece. Place the tip on the upper die, align the tip with the bending die of the upper die, and lower the upper die. Bending method of sheet metal, characterized in that bending by a predetermined angle. 2. When bending a sheet metal, (1) forming guide ridges satisfying the following requirements (a) to (d) on the sheet metal to be bent, and (a) bending line: A pair of raised pieces facing each other around the bending line, (b) a sheet metal itself is processed to form a raised piece, and (c) a V-shaped guide slope that falls toward the center. Then, a ridge for supporting it is provided to form a ridge having a substantially M-shaped cross section, the lower apex of the center of the M-shape is aligned with the bending line, and the angle αA of the V-shaped guide slope is set for the purpose of processing. The bending angle is αθ or more, and (d) a complementary recess for providing a member to the raised portion is formed on the back of the raised portion. (2) The sheet metal is aligned with the bending angle below the guide raised piece. Place it on a lower mold with an angled V-shaped groove, and similarly place the tip on it. It arranged upper die of the bending mold fitted to the lower angle, lowering the upper mold,
(3) A method of bending a sheet metal, wherein the raised portion fills the filling recess and restores the original thickness of the sheet metal by the pressing force of the upper die. 3. In bending a sheet metal, (1) forming guide ridges satisfying the following requirements (a) to (d) on the sheet metal to be bent, and (a) bending line: A pair of raised pieces facing each other around the bending line, (b) a sheet metal itself is processed to form a raised piece, and (c) a V-shaped guide slope that falls toward the center. Then, a ridge for supporting it is provided to form a ridge having a substantially M-shaped cross section, the lower apex of the center of the M-shape is aligned with the bending line, and the angle αA of the V-shaped guide slope is set for the purpose of processing. And (b) forming a supplementary concave portion for providing a member to the raised portion on the back of the raised portion, and (2) forming the sheet metal into a lower mold having a groove on the lower side of the guide raised piece. Place the tip on the upper die, align the tip with the bending die of the upper die, and lower the upper die. Bending method of sheet metal, characterized in that bending by a predetermined angle. 4. When bending a sheet metal, (1) forming guide ridges satisfying the following requirements (a) to (d) on the sheet metal to be bent, and (a) bending line: A pair of raised pieces facing each other around the bending line, (b) a sheet metal itself is processed to form a raised piece, and (c) a V-shaped guide slope that falls toward the center. Then, a ridge supporting the ridge is provided to form a ridge having a substantially M-shaped cross section, and the lower apex of the center of the M-shape is aligned with the bending line, and the angle αA of the V-shaped guide slope is set for the purpose of processing. The bending angle is αθ or more, and (d) a supplementary recess that forms a space is formed on the outer side of the raised portion. (2) An angle at which the sheet metal is aligned with the bending angle below the guide raised piece. Place it on the lower mold with V-shaped groove and bend the tip on it A feature is that a matched upper die bending die is arranged, the upper die is lowered, and (3) the pressing force of the upper die restores the original thickness of the sheet metal by filling the filling recess with the raised portion. Bending method for sheet metal.