JPH0829352B2 - Bending method for saddle warp plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for correcting saddle warp due to bending of a plate in press brake work.

[Conventional technology]

Conventionally, as a saddle warp correction method of this type, as shown in FIG. 14, there has been a method in which the mold, that is, the punch a and the die b, is warped in advance to warp the product, as opposed to the saddle warpage.

In addition, it is a general saddle warp phenomenon that internal stress of compression is generated at the inner side of bending and tensile force is generated at the outer side of the saddle.
As shown in the figure, the outside vertex d of the plate c is connected to the punch a and die b,
There was a method of crushing with b'to release the pulling internal force on the outside.

[Problems to be Solved by the Invention]

The former saddle warp straightening method had the drawback of requiring individual molds according to various conditions such as the material of the product, plate thickness, bending angle, and bending R, while the latter saddle warp straightening method had a die-side split die. There were many examples of molds, and the production of molds became a problem.

The present invention has been made in view of the above circumstances, and the purpose thereof is to obtain approximate straightness within a practical range by not performing strict saddle warp correction but only approximate correction. It is an object of the present invention to provide a method for bending a saddle warp straightening plate, which is possible, inexpensive, and highly versatile.

[Means and Actions for Solving the Problems]

In order to achieve the above object, the present invention uses punches and dies each having a length obtained by appropriately dividing the bending width, and at the time of pressing, the punches and dies are warped in the same direction as the saddle warpage for each set and adjacent to the plate. In the portion corresponding to the joint between the punch and the die, a bent portion having the same height as the apex of the back is formed in the direction opposite to the warp.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 12. FIG. 1 shows a cross section of a press brake device used in the method of the present invention, and FIG. 2 shows a cross section taken along line II-II of FIG. In the drawings, reference numeral 1 denotes a punch base, and a punch housing 1 and a punch insertion portion 3 are formed on the punch base 1. A fixed piece 4, a moving piece 5, a connecting tool 6 for connecting these pieces 4 and 5, and an auxiliary plate 7 are housed in the piece housing portion 2.

The mating surfaces 8 and 9 of the fixed top 4 and the moving top 5 have the same slope, and in the combined state, the end surfaces 10 of both tops 4 and 5,
11 will be parallel to each other.

The combination of fixed pieces 4 and moving pieces 5 is 6 in one group.
There is a pair, the fixed top 4-1 of the first combination, the moving top 5-1 and the fixed tops 4-6, 5-6 of the sixth combination have the same mating surfaces 8, 9
As shown in FIGS. 4 and 5, the inclination is made at an angle α with respect to the horizontal plane b in the moving direction a of the moving pieces 5-1 and 5-6.

Then, when the moving pieces 5-1 and 5-6 move along the mating surfaces 8 and 9, the vertical movement of Sm occurs.

Further, the fixed top 4-2 of the second combination, the moving top 5-2 and the fixed top 4-5 of the fifth combination, and the moving top 5-5 have mating surfaces 8 and 9 of the same slope. , Its slope is shown in FIGS. 6 and 7.
As shown in the figure, the angle C is formed at an angle β with respect to the moving direction a, and the angle α is formed with respect to the horizontal plane B.

Then, when the movable pieces 5-2, 5-5 move along the mating surfaces 8, 9, Sx (= αcosβ) is vertically moved.

Further, the fixed piece 4-3 and the movable piece 5-3 of the third combination and the fixed piece 4-4 and the movable piece 5-4 of the fourth combination have mating surfaces 8 and 9 having the same slope. , Its slope is shown in FIGS. 8 and 9
As shown in the figure, the angle β is 90 ° with respect to the moving direction a, and the angle α is formed with respect to the horizontal plane b. The vertical movement S ₀ when the moving pieces 5-3 and 5-4 move along the mating surfaces 8 and 9 is zero.

From the above, by adjusting the angle β, it is possible to make an arbitrary vertical movement that maximizes Sm for the same horizontal movement amount.

Mating surface between the fixed tops 4-1 to 4-6 and the moving tops 5-1 to 5-6
Grooves 22 and 23 along the moving direction a are formed in 8 and 9, and a plurality of protrusions 12 are provided at predetermined intervals on the moving pieces 5-1 to 5-6 side of the connecting tool 6. Further, both ends of the connector 6 are formed in a block shape, and a screw hole 14 is formed in the left block portion 13 along the moving direction a.

Then, one edge 6a of the connecting tool 6 is fixed to the fixing piece 4-1.
~ 4-6 is slidably inserted into the groove 22 of the mating surface 8, and the connecting tool 6
Move the edge 6b between the projections 12 of the groove of the mating surface 9 of the moving pieces 5-1 to 5-6.
23, the mating surfaces 8 and 9 are in sliding contact with each other, the end surfaces 10 of the fixed pieces 4-1 to 4-6 are in contact with the upper surface 15 of the piece accommodating portion 2, and the moving pieces are also movable. The end faces 11 of 5-1 to 5-6 are brought into contact with the auxiliary plate 7.

A fixed frame 4-1 that makes up a group of 6 pairs like this
.About.4-6 and moving pieces 5-1 to 5-6 are stored in the frame storage portion 2 in a plurality of groups.

At the left end of the punch base 1 is a movement adjusting bolt 16
Is rotatably provided, and the movement adjusting bolt 16 is screwed into the screw hole 14.

A plurality of punches 17 are lined up and inserted and fixed in the punch insertion portion 3 of the punch base 1, and one punch is provided for each group of fixed pieces 4-1 to 4-6 and movable pieces 5-1 to 5-6. 17 are arranged.

The die base 18 is also provided with a frame accommodating portion 19, and the fixed accommodating piece 4, the movable piece 5 and the connector 6 having the same structure are accommodated in the frame accommodating portion 19 upside down. An auxiliary plate 20 is placed on the upper surface of the die base 18, and a plurality of dies 21 are placed on the upper surface of the auxiliary plate 20. Die 21
Is arranged for each of the fixed frames 4-1 to 4-6 and the movable frames 5-1 to 5-6.

Next, the operation of bending the saddle warp straightening plate by the above-described press brake device will be described.

On the punch 17 side, the movement adjusting bolt 16 is rotated and screwed to move the connector 6 leftward in FIG. 1 to move the movable pieces 5-1 to 5-6 leftward. Therefore, in each group, the first and sixth moving pieces 5-1 and 5-6 move down by Sm, and the second and fifth moving pieces 5-2 and 5-5 move down by Sx. Then, the curve formed by the first to sixth moving pieces 5-1 to 5-6 has an upwardly convex arcuate shape, and a gap of δ ₀ is formed in the center.

Further, on the die 21 side, by rotating the movement adjusting bolt 16 'and screw-feeding, the connecting tool 6 is moved leftward in FIG. 1 to move the moving pieces 5-1 to 5-6 leftward. To move. Therefore, in each group, the first and sixth moving pieces 5-1 and 5-6 move down by Sm, and the second and fifth moving pieces 5-2 and 5-5 move down by Sx. Then, the curve formed by the first to sixth moving pieces 5-1 to 5-6 has an upwardly convex bow shape, and a gap of δ ₀ is formed at both ends.

In this state, the plate 24 of material is put between the punch 17 and the die 21, and when the punch 17 is lowered and pressed, the punch 17 and the die 21 are pressed.
After being deflected by δ ₀ due to the applied pressure, is brought into contact with the respective moving pieces 5-1 to 5-6 and further pressed to bend the plate 24.

By bending in this way, a plurality of longitudinal portions of the plate 24 are curved in the saddle warp direction by the punches 17 and the dies 21, respectively, and a plurality of R portions are formed in the longitudinal direction of the plate 24.

A boundary portion between adjacent R portions of the plate 24, that is, a portion corresponding to a joint between the punch 17 and the die 21 which are adjacent to each other, is relatively sharply curved at a tangent angle θ in the opposite direction to the R portions at a plurality of locations,
The initial purpose is to correct saddle warpage by partial reverse bending. (Figs. 10 and 11).

 The plate 24 thus processed is shown in FIG.

The plate 24 has a plurality of longitudinal portions 24a curved in a saddle warp direction,
The boundary between the portions 24a adjacent to each other in the longitudinal direction is a bent portion 24b that is curved in the direction opposite to the saddle warp. The apex 24c of the back portion in each of the bent portions 24b has the same height,
When the plate 24 is placed on the surface plate, each vertex 24c contacts the surface plate.

At this time, the maximum gap δ _{2 at} the center of each bend decreases in inverse proportion to the square of the length L / n of the bent portion with respect to the total length L.

That is, Note that δ ₁ is the general saddle warped plate 24 'shown in Fig. 13.
Is the maximum gap in the center of.

For example, by bending a plate with a total length of 5 m by the conventional method, the maximum clearance δ ₁
= 10 mm, according to the method of the present invention, the maximum gap δ ₂ ≈ 0.1 when bent by using 10 sets of punches 17 and dies 21 each having a length of 500 mm.
Calculated as mm, a product with practically no problem can be obtained.

By using the saddle warp correction mechanism shown as the above-mentioned embodiment, it is possible to easily obtain a high-precision product without touching the conventionally used press brake, Since they can be merged, a press brake with a saddle warp correction device that is cheaper and has excellent operability can be provided.

Also, since the mold, especially the punch side, has relatively high rigidity,
In the case of thin plate bending, there is low pressure processing that makes it difficult to bend the punch as scheduled.

At this time, the saddle warp correction can be performed by using a mold in which R is given in the longitudinal direction in advance, or by using a mold which is further divided into one group.

In any case, the flexure of the mold can be freely controlled within a certain range, so that one mold can be used to correct saddle warpage with high versatility.

〔The invention's effect〕

As described in detail above, according to the present invention, punches and dies each having a length obtained by appropriately dividing the entire bending width are used, and at the time of pressing, the punches and the dies are warped in the same direction as the saddle warpage for each set so that the plates are adjacent to each other. In the part that corresponds to the seam of the punch and die, in the opposite direction to the saddle warp, the apex of the back part forms a bent part with the same height, so the bent plate has saddle warp over the entire length, In the opposite direction from this saddle warp,
By providing a bent portion having the same height at the apex of the back portion, approximate straightness can be obtained within a practical range.

[Brief description of drawings]

1 is a sectional view of a press brake device used in the method of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, FIG. 3 is an exploded perspective view of a frame height adjusting mechanism, and FIG. FIG. 5 is a plan view of a fixed top and a moving top in a combined state, FIG. 6 is a front view of another fixed top and a moving top in a combined state, and FIG.
FIG. 8 is a plan view of the same, FIG. 8 is a front view of another fixed frame and movable frame in combination, FIG. 9 is the same plan view, FIG. 10 and FIG. 11 are explanatory views of the method of the present invention, and FIG. FIG. 13 is a perspective view of a plate having a finished shape according to the method of the present invention, FIG. 13 is a perspective view of a plate having a general saddle warp, and FIGS. 14 and 15 are explanatory views of a conventional saddle warp prevention means. 1 is a punch base, 2 is a top accommodating section, 3 is a punch inserting section, 4 is a fixed top, 5 is a moving top, 6 is a connecting tool, 7 is an auxiliary plate, 8 and 9 are mating surfaces, 17 is a punch, and 18 is a punch. Die base, 21
Is a die.

Claims (1)

[Claims] 1. A punch and a die each having a length obtained by appropriately dividing the entire bending width are used, and the punch and the die are warped in the same direction as the saddle warpage for each set at the time of pressing, and the punch and the die serve as a joint between adjacent punches and dies of a plate. A method for bending a saddle warp straightening plate, characterized in that a bent portion is formed in each of the portions in a direction opposite to that of the saddle warp, and the apex of the back portion has the same height.