JPH02274317A - Bending device for sheet metal - Google Patents

Abstract

PURPOSE:To prevent a scratch from being generated in a sheet metal by making up the tips of blades so that they can be moved by the rotation of a crankshaft along a vertically long elliptical orbit. CONSTITUTION:An upper die 11 is moved vertically by the rotation of a 3rd crankshaft to a lower die 12, the space between them is opened and when it is opened the sheet metal is inserted. When the sheet metal is clamped between the dies 11, 12, a supporting arm 13 is lowered by the rotation of a 1st crankshaft 21 and the end part of the sheet metal is bent by an upper blade 6a downward. Then, the space between the lower die 12 and the upper die 11 is opened, the sheet metal is inserted by a prescribed dimension, and clamped again between the upper and lower dies 11, 12 and the sheet metal is bent by a lower blade 6b while the supporting arm 13 is elevated. In the movement of this series of supporting arms 13, since the center O2 of an eccentric wheel 33 is turned vertically from the origin in a guide device, the orbits of the blades 6a, 6b are corrected for the best to the bending the sheet metal.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a sheet metal bending device. More specifically, the present invention relates to a blade-type bending device that clamps and fixes a sheet metal and bends the edge portion thereof by the movement of the blade.

``Prior Art'' In addition to the above-mentioned blade type, conventional sheet metal bending devices include ① bending type, ironing type, and side punch type.

■The bending type bending device is a goo with a ■-shaped groove (
The sheet metal is bent by lowering a ■-shaped punch (A type) onto the female type (female type), but the problem is that it is prone to bending, making the work dangerous and not suitable for labor-saving or automation. Because of this, there has been a shift towards other formats recently.

However, due to its structure, ironing-type bending devices cannot avoid scratches due to ironing, and since the punch is lowered vertically, that is, at right angles to the sheet metal, it is difficult to overturn the sheet metal at an acute angle in anticipation of the spring bank. The drawback was that it could not be formed.

The side punch type bending device solves the above drawback by having a side punch that rotates inverted next to the lower die and is pivoted. The sheet metal can be bent at a right angle or more by reversing the side punch, but the side punch inevitably rubs against the sheet metal, so scratches are unavoidable in this case as well.

Therefore, a blade-type bending device was developed. In the conventional blade type bending device, the blade is NCCNC.
It was mainly developed to draw a trajectory that does not rub against sheet metal through control, and an example of this is disclosed in Japanese Patent Application Laid-Open No. 61-206526. As can be seen, in the conventional blade-type bending device, the supporting arm of the blade is controlled by two wheels, a horizontal axis and a vertical axis, and a crank mechanism is used for the movement of the horizontal axis.
A pair of upper and lower cylinders was used for vertical axis movement, and a cylinder was also used to rotate the crankshaft for horizontal axis movement.

In addition, according to the conventional blade bending device, the frame is C-shaped with no flexibility, and the lower die is attached to the bottom of the opening and the upper die is opened and closed by a hydraulic cylinder or the like. Because of this, the force of tightening the sheet metal by the lower die and the upper die acts on the frame as a whole, and stress tends to concentrate particularly in the inner part of the C-shape.

``Problem to be solved by the invention'' According to the conventional blade-type bending device, the two axes are controlled by NC etc. as described above, so theoretically the blade should move on a trajectory that does not rub against the sheet metal. However, the ideal and proper movement of the trajectory differs depending on the material, thickness, bending radius, blade shape, etc. of the sheet metal, so the control program is extremely complicated, and it is difficult to create the program. It was impractical as it required a lot of effort. Moreover, the blades were powered by hydraulic cylinders that lacked stability, so even if the program was correct, accuracy could not be achieved. To explain this further, in a bending device, a large number of hydraulic cylinders are arranged horizontally at appropriate intervals, and a long upper mold or blade is operated by the cooperation of a series of hydraulic cylinders. Due to the unstable and specific nature of the force, it is difficult to obtain uniform force for each force, which tends to cause distortions and twists in the bending of the sheet metal (Also, the width of the sheet metal varies depending on the product order, but When the sheet metal is narrow compared to the total width of the bending device, the hydraulic cylinder comes off from the sheet metal at the end and presses down the long upper die or blade too much, causing them to bend. The bending action of the blade also became less uniform, which sometimes led to defective products.

In addition, when tightening sheet metal with the upper and lower molds, the tightening force is applied to the entire frame, so the frame is required to have the strength to withstand the force, which makes the frame very strong, large and heavy, and it is difficult to carry out foundation work. There was also the problem that equipment costs were excessive because the equipment was also large-scale.

In view of the above-mentioned circumstances regarding sheet metal bending devices using blades, the present invention has been developed to achieve a blade trajectory that can be obtained fairly accurately using only a mechanical structure, and to achieve uniformity in the force of the blades. To provide a sheet metal bending device which can accurately bend a sheet metal without scratches and can bend the sheet metal without scratches by a simple program even if controlled by an NC or the like.

Another object of the present invention is to provide a sheet metal bending device that can reduce the overall weight of the frame because the tightening force is not applied forcefully to the inner part of the C-shaped frame when the sheet metal is tightened with the upper and lower dies. did.

"Means for Solving the Problem" In order to achieve the above first objective, this invention (hereinafter referred to as
(referred to as Category 1 invention) is a sheet metal folding method in which a lower mold and an upper mold for tightening a sheet metal are provided in an opening of a C-shaped frame, and a blade for bending the end of the sheet metal is attached to the supporting arm of the opening. In the bending device, a crankshaft with crankpins arranged in a row is provided below the opening, the supporting arms of the blades are arranged vertically along the crankshaft, and the eccentric wheel at the lower end is fitted onto the crankpin. , a support shaft is provided above the support arm at a position higher than the middle of the height from the center of the eccentric ring to the tip of the blade, and the support shaft serves as a fulcrum for swinging, and the frame is further provided with a guide that allows the support shaft to move up and down the support arm. A sheet metal bending device was constructed in such a way that the tip of the blade could move up and down in a long elliptical orbit by the rotation of the crankshaft.

In addition, regarding the guide device for the support shaft of the support arm, a crankshaft with crank pins arranged in a row is installed in the back of the frame, and forward-facing swinging rods are arranged along the crankshaft. An eccentric ring at the base end of the swinging rod may be fitted, and the tip of the swinging rod may be connected to a support shaft serving as a fulcrum of the support arm.

Further, the support shaft of the support arm may be vertically adjustable with respect to the support arm.

Next, in order to achieve the second objective, this invention (hereinafter referred to as
21st! Invention a) is a sheet metal bending device in which a lower mold and an upper mold for tightening a sheet metal are provided in an opening of a C-shaped frame, and a blade for bending the end of the sheet metal is attached to the supporting arm of the opening.・In the installation, the frame is divided into a lower frame and an upper frame at the height of the opening, and at the back of the opening, the upper frame is pivotally supported on the lower frame so that it can be opened and closed, and crank pins are arranged in rows. A crankshaft is provided at the lower part of the opening, and a plurality of support rods supporting the upper frame are arranged vertically at the front end of the frame along the crankshaft, and the eccentric ring at the lower end of the support rod is connected to the crankshaft. A sheet metal bending device was constructed by fitting the support rod into the pin and pivotally supporting the upper end of the support rod to the upper frame at a position directly above the crankshaft.

"Function" The folding device of the eleventh invention described above will first be explained based on FIG. 1.

When the crankshaft 21 rotates, the eccentric wheel 28 at the lower end of the blade support arm 13 also rotates, and at the same time, the support shaft 4 moves up and down, and the blade 6 above the support shaft 4 rotates in the opposite direction to the crank pin. move. However, since the distance M r-z to the tip of the blade 6 is shorter than the distance from the support shaft 4 to the center OI of the eccentric wheel 28, the center 01 swings back and forth.
The width of the tip of the blade swinging back and forth is smaller than the width,
Therefore, the tip of the blade draws a vertically long elliptical trajectory R, and the thick line portion shown in the figure is used for bending. Also, due to the special nature of the crank mechanism, the greatest force can be obtained near the end of the bend.

By the way, the ideal trajectory of the blade that does not damage the sheet metal when bending it is determined by the arc shape 31 for bending the sheet metal and the arc shape 30 of the curved tip of the blade, as shown in FIG. . If the tip of the blade advances in both turns, for example, to wind up the thread 5, the desired trajectory R is obtained, but as shown in the figure, this trajectory R is an elliptical shape with a vertical length of 1'.

The trajectory R1 shown in FIG. 1 is the case where the support shaft 4 is guided straight up and down (guide line S), but it is very close to the ideal trajectory R, and if the trajectory R1 is used as the basis, the fulcrum The ideal trajectory R can be brought as close as possible by the variable guidance or position adjustment in step 4.

The invention of item 2 and the invention of item 3 respectively adjust the trajectory R by adjusting the position of the fulcrum 4 by guiding the fulcrum 4.
1 can be modified, and in the case of the invention of item 2, the invention of item 3 can be modified.
As shown in the figure, the guide line T of the fulcrum 4 is made into a circular orbit centered on the center point 0 of the swing by the swing of the swing rod 8, that is, the center 02 of the eccentric wheel, and the rotation of the crankshaft 22 The circular orbit is changed as shown by the arrow, thereby making it possible to bring the orbit R1 as close as possible to the ideal orbit.

In addition, as in the third aspect of the invention, the support shaft 4 is connected to the support arm 13.
By changing the height position of , the size and shape of the elliptical orbit R1 can be changed. If this adjustment causes the position of the support shaft 4 to become less than half the height of the blade 6 (L
Even if there is a case where the L2 wall is thicker than l, it does not contradict the spirit of the invention δ.

Furthermore, in the invention of Category 1, as the crankshaft 210 rotates, each of the support arms 13 connected thereto mechanically moves uniformly, and unlike the case of a hydraulic cylinder, the presence or absence of a sheet metal, that is, the presence or absence of a reaction, is determined. Since the movement is the same regardless, the sheet metal can be bent evenly across its entire width.

In addition, in the second aspect of the invention, since each swinging rod 8 is connected to the crankshaft in the support shaft guide device, the trajectory correction of the blade 6 is applied equally to each support arm 13 based on the same principle. be able to.

2nd #! In invention 4, the strength of the support rods tightens the upper and lower molds, and the effect is exerted at the positions of the upper and lower molds, so that the force hardly reaches the rear end of the frame, and the support rods do not have much strength. Since it is not necessary, not only the frame but also the overall strength is not required.

"Example" Next, embodiments of the present invention will be described based on the drawings.

FIGS. 4 and 5 show an embodiment, in which the bending device includes a C-shaped frame IO, an upper mold 11, a lower mold 12,
, a blade support arm 13, a swinging rod 8, a supporting rod 9, etc. are provided.

The frame 10 is constructed by pivotally supporting an upper frame 16 at each rear end of lower frames 15 arranged horizontally at equal intervals,
It is C-shaped and has an opening 19 at the front end.

The lower frame 15 is provided with a row of brackets 17 for pivotally supporting the upper frame 16 at its rear end, and a mounting base 18 for the lower die 12 at its front end. Further, a first crankshaft 21 for driving the support arm 13 is provided at the front end of the lower frame 15,
A third crankshaft 23 for driving the support rod 9 is supported through the entire width of the shaft. In addition to providing the support shaft 20 of the upper frame 16 on the bracket 17, a second crankshaft 22 for operating the swinging rod 8 is also supported thereunder by passing through the entire width of the beam of the frame 10.

i-1 Each of the second and third crankshafts 21.2223 has crank pins 21a, 22a, 2 at equal intervals.
3a is formed.

The upper frame 16 has a row of brackets 25 that are pivotally supported by a support shaft 20 at the rear end, and an upper die 11 is attached to the front end, as well as a bracket throat 26 that pivotally supports the support rod 9.

The blade support arms 13 are vertically arranged and arranged at regular intervals along the first crankshaft 21, that is, laterally, and have an eccentric ring 28 fitted to the crank pin 21a of the first crankshaft 21 at the lower end. An upper blade 6a and a lower blade 6b are attached to the upper end. Further, a support shaft 4 is provided at a rear end portion away from the center O1 of the eccentric wheel 28 and near the lower blade 6b.

The guide device G of the fulcrum 4 uses a swinging rod 8, and the crank pin 22 of the second crankshaft 22 is attached to the base end of the swinging rod 8.
An eccentric ring 33 is formed to fit into the shaft a, and its tip is pivotally supported on a support shaft 4.

The support rod 9 has an arcuate shape that curves backward so as not to be caught by the support arm 13, and has an eccentric ring 35 at its lower end that fits onto the crank pin 23a of the third crankshaft 23, and an upper end that is connected to the bracket 26 by a pin 36. It is connected by .

Next, the operation of the above-mentioned bending device will be explained.

Before operation, the center 02 of the eccentric wheel 33 of the swinging rod 8 is adjusted so as to be movable back and forth and up and down to a position as a starting point.

The upper mold 1 is attached to the lower mold 12 by 230 rotations of the third crankshaft.
1 moves up and down, and the space between them opens and closes, so when the metal plate P is inserted when it is opened, and the metal plate P is tightened between the molds 11 and 12, the support arm 13 is lowered by the rotation of the first crankshaft 21. The end of the sheet metal P is bent downward by the upper blade 6a, and then the space between the lower mold 12 and the upper mold 11 is opened, and after the sheet metal P is pushed in by a predetermined dimension, the upper and lower molds 11 and 12 are bent again. After being tightened between the supporting arms 13
By rising, the sheet metal P is bent upward by the lower blade 6b. During this series of movements of the support arm 13, in the guide device G, the center 0□ of the eccentric ring 33 rotates up and down from the origin, so that the trajectory of the blades 6a, 6b is optimally corrected for bending the sheet metal P. be done.

"Effects of the Invention" As explained above, the present invention significantly exhibits the following effects.

According to the invention of Category 1, the eccentric ring at the lower end of the support arm that fixes the blade is fitted onto the crank pin, and the support arm has an upper part attached to the support arm at a position higher than the middle of the height from the center of the eccentric ring to the tip of the blade. A support shaft is provided as a fulcrum for swinging, and the frame is also equipped with a guide device that allows the support shaft to move up and down the support arm, so the tip of the blade traces a long approximately elliptical trajectory up and down. When the blade bends, an ideal trajectory is obtained that does not rub between the blade and the blade, and even without NC control, scratches on the sheet metal can be prevented by mechanical movement alone. It is also easy to program. In addition, the crank pins into which the eccentric wheels of the support arms fit are arranged in rows on the crankshaft, and each blade moves in the same trajectory due to the movement of the two crankshafts, resulting in uniform movement of each blade. The sheet metal can be bent evenly, and even if the sheet metal is narrower than the length of the blade and a blade comes off from it, no distortion occurs in the sheet metal bending.

It is possible to simply guide the support arm's support shaft up and down, but
When the guide device is configured by fitting the eccentric ring at the base end of the swinging rod to the crank pin of the crankshaft and connecting the tip of the swinging rod to the support shaft that serves as the fulcrum of the support arm, only the mechanical configuration is possible. By adjusting the blade movement, it is possible to get as close to the ideal trajectory as possible without causing scratches on the sheet metal.

When the support shaft of the support arm is vertically adjustable with respect to the support arm, the height of the support shaft 4 can be adjusted to approximate the ideal trajectory.

In the second type of invention, since the action of tightening the upper and lower molds by the support rod is performed at a position close to the location where the upper and lower molds are tightened,
Since most of the tightening force is received by the support rods, the frame does not require much strength, and the entire device can be made economically and lightweight. Similarly, the crank mechanism ensures uniform tightening of the upper and lower molds, allowing for accurate bending of sheet metal without distortion.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the basic trajectory of the blade in the first type of invention. FIG. 2 is an explanatory diagram for determining a generally ideal trajectory of the blade. FIG. 3 is an explanatory diagram in which the basic trajectory of the blade is corrected in the invention of 1'R. 4 and 5 show an embodiment of the present invention, and FIG.
The figure is a sectional view seen from the side, and FIG. 5 is a partially enlarged sectional view of FIG. 4. G...Spindle guide device 0, . 0. ... Center of eccentric ring P ... Sheet metal Rl + Rz ... Raceway 4 ... Support shaft 6.6 a, 6 b, - Blade 8 ... Swinging rod 9 ... Support rod 0 ... - Frame... Upper die 2... Lower die 3... Support arm 5... Lower frame 6... Upper frame 9... Opening 1.22.23... Crank shaft la, 22a , 23a--Crank pin 8.33.3
5... Eccentric wheel

Claims (1)

[Claims] 1) A sheet metal bending method in which a lower mold and an upper mold for tightening the sheet metal are provided in the opening of a C-shaped frame, and a plate for bending the end of the sheet metal is attached to the support arm of the opening. In the device, a crankshaft with crankpins arranged in a row is provided in the lower part of the opening, the support arms of the blades are arranged vertically in a row along the crankshaft, and the eccentric wheel at the lower end is fitted to the crankpin, The support arm is provided with a support shaft that serves as a fulcrum for swinging at a position higher than the midpoint of the height from the center of the eccentric ring to the tip of the blade, and the frame is further equipped with a guide that allows the support shaft to move up and down the support arm. 1. A sheet metal bending device, characterized in that the device is configured such that the tip of the blade can move up and down in a long elliptical trajectory by rotation of the crankshaft. 2) Regarding the guide device for the support shaft of the support arm, a crankshaft with crank pins arranged in a row is installed in the back of the frame, and forward-facing swinging rods are arranged along the crankshaft. Bending of sheet metal according to claim 1, characterized in that an eccentric ring at the base end of the swinging rod is fitted, and the tip of the swinging rod is connected to a support shaft serving as a fulcrum of the support arm. Device. 3) The sheet metal bending device according to claim 1 or 2, wherein the support shaft of the support arm is vertically adjustable with respect to the support arm. 4) In a sheet metal bending device, a lower mold and an upper mold for tightening the sheet metal are provided in the opening of a C-shaped frame, and a blade for bending the end of the sheet metal is attached to the supporting arm of the opening. The upper frame is divided into a lower frame and an upper frame at the height of the opening, and the upper frame is pivotably supported on the lower frame at the back of the opening so that the upper frame can be opened and closed. Furthermore, a plurality of support rods supporting the upper frame are arranged vertically along the crankshaft at the front end of the frame, and the eccentric ring at the lower end of the support rod is fitted into the crank pin of the crankshaft. A sheet metal bending device characterized in that an upper end is pivotally supported on an upper frame at a position directly above a crankshaft.