JPH01138020A - Pressing device for bending sheet metal - Google Patents

Abstract

PURPOSE:To prevent scratches of a press product by operating a special mechanism capable of vertically moving a clamp rest for a sheet metal composed of an adjacent punch part and its engaging piece, etc. CONSTITUTION:The sheet metal 5 also falls according as a clamp 51 falls. Then, the side punch 12 is pushed up by a receiving shelf 16 to the clamp rest 11 and reversed up around the central shaft 33 to fold the end 5a of the sheet metal 5. In other words, the force to fold the sheet metal 5 by the principle of lever works strongly in the neighborhood of the lever edge 59 to reduce the bending resistance of the sheet metal 5. Hereby, the scratch of the product can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a bending press working apparatus for sheet metal such as galvanized iron plates, copper plates, and stainless steel plates.

``Prior Art'' Typical examples of conventional devices of this type include: (1) bending type, ironing type, and side punching type.

1) V-bending type equipment is the earliest and most basic device, in which a ■-shaped punch (male die) is lowered into a die (female die) with a ■-shaped groove, and the sheet metal is bent between them. .

2) The ironing type device is a device that tightens a sheet metal onto a die with a clamp from above, and lowers a punch on the side of the die to squeeze and bend the sheet metal. (
The one shown in Figure 6, which will be described later, is also a type of ironing type in which the structure is upside down and different. ) 3) In the side punch type device, a side punch is installed next to the clamp pedestal on the table holder, and when the sheet metal is sandwiched on top of the clamp pedestal and pressed from above with the clamp, the side punch is interlocked. The side punch is L-shaped with a petal projecting laterally at the lower end, and is pivotally attached to the table holder at the lower end (L-shaped bent part), and It is biased by a spring in the lateral direction away from the clamp pedestal, and when the clamp pedestal is pushed down by the pressure of the clamp, it steps on the peckle, causing the side punch to reverse and strike the edge of the sheet metal. It is configured to be bent into a die on the side of the clamp.

``Problems to be solved by the invention'' In the bending press processing of sheet metal, problems such as bending (also known as bending), springback (elastic restoration), scratches due to friction, and labor-saving problems can be solved. It is considered the main thing to do.

10. With bending type products, it is possible to bend more than the right angle to the bending angle (overforming) in anticipation of springback, and scratches are less likely to occur, but if one end of a wide sheet metal is bent, one end of the sheet metal will be The robot is lifted high, and its gravity tends to cause the waist to buckle, and it also tends to cause danger from jumping.

Such defects not only greatly affect the quality of the product, but also impede automation or labor saving, so currently, the second. The third one is the mainstream.

Regarding the second ironing type device, it is of course impossible to avoid the occurrence of scratches due to ironing due to its structure, and since the punch is lowered vertically, that is, at right angles to the sheet metal, it is not possible to avoid scratches due to ironing. There was a problem that it could not be formed.

In order to solve this problem of overforming, the present applicant developed the device shown in FIG. 6 prior to the present invention. In other words, the clamp pedestal 2 is attached to the pedestal holder 1.
and the side punch 3 are arranged side by side, and when the clamp 4 presses the sheet metal 5 against the clamp holder 2, the clamp holder 2 is pushed down against the elasticity of the spring 6, and the lowering of the clamp 4 causes the side punch 3 to move. The end portion 5a of the sheet metal 5 is bent to a side die 4a formed on the clamp 4, and the punch surface 3a of the side punch 3 and the side die 4a of the clamp 4 are formed on the same slope. In addition, the sheet metal 5 can be bent at an acute angle by configuring the side die 3a and the punch surface 4a to rub against each other obliquely due to the rubbing of the guide slopes 7.8.

However, in this case, it is not possible to freely set the bending angle of the sheet metal unless the mold is changed, and even if a large number of molds are prepared, the amount of springback is not constant depending on the material of the sheet metal. Furthermore, it was impractical as it was necessary to prepare molds for each material.

Next, in the third side punch type device, when installing the side punch, the shaft is protruded from both ends and supported by a stand holder, so the central part lacks stability, especially when pressing. As a result of the side punches flexing between the ends, the pressing force is uneven and the bent ends of the sheet metal are not flush all the way around, causing an unsightly bulge towards the center, and Since the pivot axis of the side punch is separated by a considerable distance from the bending point of the sheet metal, it is difficult to apply a strong force to the bending point using the principle of leverage, so it is difficult to bend the sheet metal strongly and sharply, and the round Not only did it become close to bending, but springback occurred more than expected, making it impossible to obtain accurate bending angles for the product, which also caused the bending part in the center to bulge out. .

Furthermore, with this side punch type, there are fewer scratches compared to the ironing type, but because the pivot shaft of the side punch is fixedly supported at a certain position relative to the table holder, the clamping Since there is a large deviation corresponding to the amount by which the side punch descends relative to the side punch, it is inevitable that the sheet metal will be scratched due to the deviation.

This invention was made in view of the above-mentioned circumstances, and it is possible to prevent the occurrence of scratches on the product as much as possible, and not only can it be bent at any angle within a certain range, but also has a sharp and uniform shape over the entire length. The main objectives are to be able to obtain a bending angle and to be able to appropriately overform so that the expected springback can be obtained.

"Means for Solving the Problems" In order to achieve the above object, the present invention has a structure in which a plate holder that holds a sheet metal clamp pedestal in a vertically movable manner is provided with a side punch adjacent to the clamp pedestal. forming a receiving tank;
A bearing groove for the side punch is provided at the upper end of the side surface of the clamp pedestal, and an engaging piece is provided at the base end of the side punch, the tip of which engages with the bearing groove and becomes the central axis of reversal, and The lower end side near the bearing groove is used as a die, and a punch part for bending the sheet metal is provided protruding from the die, and the clamp holder is mounted upward so that it can be moved up and down by the holding motion of the clamp. A sheet metal bending press processing device that is equipped with an energizing spring so that the side punch is turned upside down in the receiving shelf and held therein by the movement of the central axis relative to the receiving tank as the clamp pedestal moves up and down. The gist is:

According to the above configuration, the reversal center axis of the side punch moves up and down together with the clamp holder, and the side punch is reversed due to the relative up and down movement between the center axis and the receiving tank, and the punch part is used to bend the sheet metal onto the die of the clamp, but since the center axis of the side punch's reversal always maintains a certain short distance from the bending point of the sheet metal, the extent to which the side punch rubs against the sheet metal is This is extremely small compared to the case where the punch is pivotally supported on the table holder, and it is possible to strongly apply the appropriate force for overforming to the bending point.In addition, the side punch is attached to the clamp holder. Since it is always supported by the receiving tank and stably supported over the entire length, there is no risk of bending in the center, and the sheet metal can be bent evenly, strongly, and neatly.

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

1 to 5 show one embodiment, and the sheet metal bending press processing apparatus has a clamp holder 50 provided above the table holder 10 so as to be movable up and down, and a clamp holder 50 mounted on the table holder IO. 11 and a side punch 12,
Clamp 51 that presses sheet metal 5 against clamp holder 50
It is composed of: Then, attach the stand holder 10 to the aircraft B.
The clamp holder 50 is fixed to the vertical drive body C for the body B.

The stand holder 10 is assembled with a main body 10a and a backing plate 10b, and the main body LOa is formed in three stages lower to the back and the backing plate 10b is fixed to the rear side.
1 storage groove 15 is provided, and a receiving tank 16 for the side punch 12 is connected to the front opening edge of the storage groove 15.

The storage groove 15 has a vertical inner side surface, and holding holes 18a for the coil springs 17 are provided at equal intervals on the bottom surface, and a holding core 19 is erected at the center of the holding holes 18a.

Further, the receiving tank 16 has a horizontal bottom surface 25 and vertical side surfaces 26, and the bottom surface 25 is provided with a protruding edge 27 at the edge of the storage groove 15 for regulating the position of the side punch I2.

The clamp pedestal 11 has a rectangular cross-sectional shape that fits into the storage groove 15 so as to be movable up and down. It is formed into an arcuate surface (Fig. 5), and the opening is wide and open.

Further, a holding hole 18b opposite to the holding hole 18a of the stand holder 10 is provided on the bottom surface of the clamp pedestal 11, and a holding core 19 is also provided in the holding hole 18b (FIG. 1).

The side punch 12 has an inverted fan shape in cross section, and is provided with a retaining piece 31 that protrudes in the proximal extension direction at the base end of the fan shape, and a punch part 32 that protrudes upward. The tip of 31 is the central axis of inversion 33, and its center is 0.
The outer surface 33a is formed into the same circular arc surface as the circular arc surface of the bottom surface 30a of the bearing groove 30 so that the position of the bearing groove 30 does not shift.
Figure 5). Further, the tip end surface of the sector of the side punch 12 is formed into an arcuate surface of a circle centered on the center O of the central shaft 33 as a tread surface 35 for the side surface 26 of the receiving tank 16,
The radius R of the circle is equal to the horizontal distance from the center 0 position of the central shaft 33 in the bearing groove 30 to the side surface 26 of the receiving shelf 16 (FIG. 4). And tread surface 35
The outer surface of the lower end continuous to the receiving shelf 16 is formed into an arcuate surface of a circle centered on the center 36 of the lower end as a sliding surface 35a with respect to the bottom surface 25 of the receiving shelf 16 (FIG. 5).

Further, the outer surface of the tip of the punch portion 32 is formed into a rounded arc surface of a circle centered on the center 38 of the tip as a thrusting surface 37 against the sheet metal 5, and the side surface on the central axis 33 side is used as the final joining surface 37 to the sheet metal 5. The surface 39 is formed flat.

The clamp holder 50 consists of a main body 50a and a fixing plate 50b for the clamp 51 (Fig. 1).
Among them, the main body 50a has a lower surface formed lower in three stages, and a clamp 51 is tightened at the uppermost part by a contact plate 50b. A space 52 is provided at the central step portion, into which the end portion 5a of the sheet metal 5 is bent. Further, the lowermost hanging portion is formed as a thrust plate 55 whose inner surface 56 is vertical and which rubs against the outer surface 40 of the platform holder 10.

The clamp 51 has a die 58 integrally molded on the front side of the lower end, and the lower edge 59 of the die 58 is formed at an acute angle at a position corresponding to the front edge of the clamp pedestal 11.
The end portion 5a is provided with a recessed notch 60 that is bent at an acute angle.

Next, the operation of the above embodiment will be explained.

When the metal plate 5 is inserted onto the clamp holder 11 (first
), the clamp 51 descends and fixes the sheet metal 5 on the clamp pedestal II (two-dot chain line in FIG. solid line).

At this time, the clamp 51, clamp pedestal 11, and sheet metal 5 descend together relative to the platform holder 10, but since the side punch 12 is received by the receiving shelf 16 provided on the platform holder 10, the receiving shelf 16 As a result, the sheet metal 5 is pushed up against the clamp pedestal 11, turned upward about the central axis 33, and the end portion 5a of the sheet metal 5 is bent.

The bending of the sheet metal 5 mainly occurs at the location where it hits the lower edge 59 of the die 58, but since the contact point P of the punch portion 32 with the sheet metal 5 is quite far from the lower edge 59 just before the bending begins, the sheet metal 5 The force of refraction is strong near the lower edge 59, and the sheet metal 5 is easily bent. In other words, since there is little resistance to bending the sheet metal 5, it is possible to prevent scratches from occurring due to the punch portion 32 coming into contact with the sheet metal 5.

Since the center of refraction of the sheet metal 5 and the center of reversal 0 of the side bunch 12 are slightly different in position, it is avoided that the trajectories 62 and 63 of the first two contact points P shift and a difference d occurs between them. I can't. However, as can be seen from the fact that the difference d is much smaller than the drop of the clamp 5I, the extent to which the punch portion 32 rubs against the sheet metal 5 is extremely small compared to the conventional side punch type. In this respect as well, the occurrence of scratches can be effectively prevented.

Therefore, structurally, the center of inversion of the side bunch 12 is 0
The occurrence of scratches can be further prevented by bringing the bearing groove 33 as close as possible to the lower edge 59 of the die 58, that is, by positioning the bearing groove 33 as high as possible to reduce the difference d between the two raceways 62 and 63. .

When the end portion 5a of the sheet metal 5 is bent at a right angle (FIG. 3), the final joining surface 39 of the punch portion 32 is joined to the sheet metal 5 evenly over a wide area up to the bent point, so that from now on, the punch The bending force by the portion 32 is directly applied to the bent portion of the sheet metal 5. Incidentally, the pressing force of the punch portion 32 acts in the tangential direction of a circle (not shown) centered on its rotation center O, and the center 0 is located at the die 58.
Since it is located at a position deeper than the position of the lower edge 59 (rearward), it is easy to press the sheet metal 5 toward the acute-angled tip of the lower edge 59.

When bending the sheet metal 5 at right angles, overforming will begin, and in this way, not only is the force applied directly to the bent part, but also the contact point Q of the side bunch 12 with the bottom surface 25 of the receiving shelf 16 is rotated. By gradually moving away from the center 0 (as the distance S increases), the moment of the force that rotates the side bunch 12 increases, resulting in a large force being applied to the bending part very close to the rotation center O. , the desired right-angled refraction angle can be accurately obtained for the product with reliable bending and little overforming, and,
A sharp and orderly refraction pattern is obtained.

Additionally, the side punch 12 extends over the entire length of the clamp pedestal 11.
and the receiving tank 16, and rotates in reverse due to their relative vertical movement, so it does not bend unlike when it is pivoted at both ends, and is spread evenly over the entire length. Strong (Since the sheet metal 5 is pressed, there is no risk that the refracting piece of the sheet metal 5 will bulge out at the center of its length.

Regarding the reversal operation of the side punch 12, since its tread surface 35 is a circular arc surface centered on the center O, it always maintains contact with the side surface 26 of the receiving tank 16, and the tread surface 35 moves on the side surface 26. Since the center shaft 33 is reversed while rotating at , the engagement of the center shaft 33 with the bearing groove 30 is reliably maintained.

Next, when the operation of bending the sheet metal 5 to a predetermined angle is completed, the clamp 51 rises, and the clamp pedestal 11 also rises at the same time due to the repulsive force of the spring 17, so that the center 0 of the reversal is lifted, and the side punch 12 is The trend side 35
Then, it falls over while rotating downward on the side surface 26 of the receiving tank 16. When the clamp pedestal 11 separates from the sheet metal 5 due to the loss of the repulsive force of the spring 17, the processed sheet metal 5 is pulled out and the next sheet metal 5 is inserted.

"Effects of the Invention" As explained above, the present invention forms a side punch receiving tank adjacent to the clamp holder in a base boulder that holds a sheet metal clamp holder in a vertically movable manner. A bearing groove for the side punch is provided at the upper end of the side surface of the stand, and at the base end of the side punch there is a retaining piece whose tip engages with the bearing groove and becomes the central axis of reversal, and a retaining piece that becomes the central axis of reversal. Since the lower end side near the bearing groove is used as a die and the punch part that inverts and bends the sheet metal is provided protruding from the die, the bending part of the sheet metal and the center of inversion of the side punch are not only close but also integral. As it moves downward, the extent to which the punch part rubs against the sheet metal is extremely small.Also, due to the position of the inversion center axis of the side punch, the punch part slightly pushes up against the sheet metal at the cylindrical part inserted from the bending point, so the punch part rubs against the sheet metal. No excessive force is applied, and scratches on the product can be prevented as much as possible.

In addition, the degree of inversion of the side punch can be changed by adjusting the degree of descent of the clamp, so the bending angle of the sheet metal can be adjusted without changing the mold. The bending angle of the product is sharp and uniform throughout the entire length because the product does not bend as it would if

In addition, since overforming can be effectively applied over the entire length, excellent effects such as being able to obtain an accurate bending angle in anticipation of springback can be achieved.

In addition, there is no phenomenon such as bending of the sheet metal, making it suitable for labor saving.
It has a simple structure and can be bent precisely.

[Brief explanation of the drawing]

1 to 5 show one embodiment of the present invention.
The figure is a cross-sectional view of the main part shown at the initial stage of the sheet metal bending cycle, Figures 2 to 4 are cross-sectional views of the main part explaining the bending order of the sheet metal, and Figure 5 is a cross-sectional view of the main part shown separately. It is an explanatory view of a cross-sectional shape. FIG. 6 is an explanatory diagram of a device at a preliminary stage that was tried before arriving at this invention. 5... Sheet metal 10... Base holder 11... Clamp pedestal 12... Side punch 16... Receiving tank 17... Spring 30,... Bearing groove 31... Holding piece 32...Punch part 33...Center shaft 51...Clamp 58...Die 5...Sheet metal 10...Base holder 11...Clamp pedestal 12...Side punch 16...・Receiving tank 17 +0. L: fne 30...Bearing groove 31...Engagement piece 32...Punch part 33...Center shaft 51...Clamp section N Method:/ ・ ■N effect. 17, y 7/, 1] Proclamation ゛”

Claims (1)

[Claims] A side punch receiving shelf adjacent to the clamp holder is formed on a holder that holds a sheet metal clamp holder so as to be able to move up and down, and a side punch bearing groove is provided at the upper end of the side surface of the clamp holder. At the base end of the punch, there is an engagement piece whose tip engages with the bearing groove and becomes the central axis of reversal, and the lower end side of the clamp near the bearing groove is used as a die and is inverted into a sheet metal piece. In addition, the base holder is provided with a spring that biases the clamp holder upward so that it can be moved up and down by the holding motion of the clamp, and the clamp holder is provided with a spring that biases the clamp holder upwardly so that it can move up and down as the clamp holder moves up and down. 1. A sheet metal bending press processing device, characterized in that a side punch is turned upside down within a receiving shelf and held therein by movement of a central axis.