JP2001121214A - Press brake crowning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press brake crowning device which can prevent the breakage and deformation of upper and lower tables of a press brake, deflect the tables parallel to each other, and improve the bending precision. SOLUTION: A slit 9 is provided in the lower table 5L so that the upper table 5U and the lower table 5L are deflected parallel to each other when the work W is bent in cooperation with a punch P and a die D through the relative vertical movement of the upper and lower tables 5U and 5L, a round hole 13 provided at an end part of the slit 9 on the center side of the lower table is reinforced by a reinforcement plate 19 at forward and rear sides, and the forward and rear reinforcement plates 19 are connected to each other by a connection member 17 piercing the lower table 5L so that the lower table 5L and the upper table 5U are deflected parallel to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press brake crowning apparatus in which a slit is provided in a lower table for flexing upper and lower tables in a press brake in parallel.

[0002]

2. Description of the Related Art Referring to FIGS.
The press brake 105 which has a punch P attached to the lower end of the upper table 101U and a die D attached to the upper end of the lower table 101L to bend the workpiece W in cooperation with the press table 105 has a slit in the lower table 101L. The notch 107 allows the upper and lower tables 101U and 101L to bend in parallel during processing, thereby improving the accuracy at low cost.

[0003]

However, in such a conventional technique, as shown in FIG. 8 (A), when a uniform load is applied to the lower table 101L, for example, as indicated by a broken line. Deform to.

[0004] This lower table 101L is shown in FIG.
As shown in the figure, when the upper beam 109U and the lower beam 109L are considered to be separated from each other with the slit 107 as a boundary, the upper beam 109U bends and becomes parallel to the upper table 101U to obtain accuracy. . At this time, stress is generated at the portion A in FIG. 8B. Similarly, a load is applied to the lower beam 109L, and the lower beam 109L is deformed in a direction in which the space between the portions C and D becomes narrower, and a high stress is generated in the portion B.

For this reason, there is a problem that when pressure is applied, a high stress is generated in a portion B in FIG. 7 (A), and the stress exceeds the allowable stress, causing breakage or plastic deformation, thereby lowering the bending accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and prevents the upper and lower tables of the press brake from being damaged and deformed so that the upper and lower tables are flexed in parallel to achieve bending accuracy. An object of the present invention is to provide a press brake crowning device capable of improving the performance.

[0007]

To achieve the above object, a crowning device for a press brake according to the present invention is provided with a punch attached to a lower end of an upper table and an upper end of a lower table. A press brake crowning device for bending a work in cooperation with a die, wherein a lower side of a slit provided in the lower table and a lower side of the slit provided in the lower table to make the bending of the upper table and the lower table parallel. A pair of reinforcing plates for connecting a portion closer to the center of the lower table from the round hole at the tip to reinforce both front and rear surfaces of the lower table, and a connecting member penetrating the lower table to connect the pair of reinforcing plates. It is characterized by becoming.

Therefore, when the work is bent in cooperation with the punch and the die by the relative vertical movement of the upper and lower tables, a slit is provided in the lower table so that the bending of the upper table and the lower table becomes parallel. While the round hole provided at the lower table center side end of this slit is reinforced with reinforcing plates from both front and rear sides,
The front and rear reinforcing plates are connected by a connecting member penetrating the lower table so that the bending of the lower table is parallel to the bending of the upper table.

According to a second aspect of the present invention, in the crowning apparatus for a press brake according to the first aspect, the reinforcing plate has a substantially triangular shape as a whole, and a lower side of the slit and A side near the center above the round hole is fixed to the lower table by welding.

Therefore, the substantially triangular reinforcing plate is fixed to the lower table by welding the lower side of the slit and the side closer to the center than the round hole to reduce the stress generated near the round hole of the slit.

According to a third aspect of the present invention, in the crowning apparatus for a press brake according to the first aspect of the present invention, the lower table is arranged so that the connecting member does not contact a through hole provided in the lower table. Penetrating therethrough.

Therefore, the reinforcing plates on both sides are connected by a connecting member penetrating the lower table so as not to come into contact with the through holes provided in the lower table, thereby reducing the stress generated in the reinforcing plates.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 3A and 3B show the entire press brake 1, but since the press brake 1 is already well known, only its outline will be described.

In the press brake 1, left and right side plates 3L,
An upper table 5U is provided between the upper front surfaces of the side plates 3L and 3R so as to be vertically movable. Left and right cylinders 7 are provided on the upper front surfaces of the side plates 3L and 3R, and move the upper table 5U up and down. A punch P is exchangeably attached to the lower end of the upper table 5.

A lower table 5L is fixed between the lower front surfaces of the side plates 3L and 3R, and a die D is exchangeably mounted on the upper end of the lower table 5L. At the center height position of the lower table 5L, slits 9 whose details will be described later are provided from both left and right ends toward the center as a crowning device for bending the upper and lower tables 5U and 5L in parallel.

With the above structure, the work W is positioned between the punch P and the die D, the upper table 5U is lowered by the cylinder 7, and the work W is bent in cooperation with the punch P and the die D. It is.

FIGS. 1A and 1B show an embodiment of a crowning apparatus 11 for a press brake according to the present invention. In the crowning device 11, a slit 9 is provided at the center height position of the lower table 5L from the left and right ends to the center downward.
Are provided with substantially circular round holes 13 on the left and right sides near the center of the lower table 5L.

Referring to FIG. 2 as well, a through hole 15 is provided above the round hole 13 in the lower table 5L, and a round bar 17 as a connecting material penetrates the through hole 15. Is provided. The diameter of the through hole 15 is larger than the diameter of the round bar 17, so that the round bar 17 does not hit the lower table 5L even when the lower table 5L is bent.

On both front and rear surfaces of the lower table 5L at the positions of the left and right slits 9, a reinforcing plate 19 having a generally triangular shape is fixed to the round bar 17 so that a part of the lower plate 5L extends over the slits 9. Sides L1 and L2 indicated by thick lines in FIG. 1A are fixed by welding. Here, the side L1 is located above the slit 9 and closer to the center than the round hole 13 at the tip of the slit 9, and the side L2 is located below the slit 9.

As described above, by providing the front and rear two reinforcing plates 19, when pressure is applied, the reinforcing plates 19 in FIG.
Corresponds to the stress concentration occurring in the B portion. FIG.
(A) The C portion of the middle reinforcing plate 19 is processed into an arc shape to prevent stress concentration.

FIG. 4 shows the state of stress in the vicinity of the round hole 13 described above.
FIG. 5 shows the above-described reinforcing plate 19 and a stress state in the vicinity thereof. FIG. 6 shows a stress state near a round hole of the conventional press brake 1 for reference.

From the above results, by connecting the lower side of the slit 9 and the upper side of the slit 9 to the center of the lower table 5L with the reinforcing plate 19 and further connecting the two reinforcing plates 19 with the round bar 17, The stress near the round hole 13 of the slit 9 of the lower table 5L can be reduced.

Further, since the reinforcing plate 19 is provided on both front and rear sides of the lower table 5L, the stress of the reinforcing plate 19 can be reduced. Further, the portion where the stress is concentrated in the reinforcing plate 19 is processed into an arc shape to prevent the stress concentration.

Thus, the upper and lower tables 5 can be formed using an inexpensive device.
U and 5L can be bent in parallel, and the processing accuracy can be improved.

It should be noted that the present invention is not limited to the above-described embodiment of the present invention, but by making appropriate changes,
It can be implemented in other aspects. That is, in the above-described embodiment of the present invention, the case where the upper table 5U is applied to the press brake 1 in which the upper table 5U is lowered by the cylinder 7 and bending is performed in cooperation with the die D is described. Can be similarly applied to the case where bending is performed by raising the height.

[0027]

As described above, in the crowning apparatus for a press brake according to the first aspect of the present invention, the upper and lower tables are relatively moved up and down so that the punch and the die cooperate to bend the work. A slit is provided in the lower table so that the bending of the table and the lower table are parallel to each other, and a round hole provided in the lower table center end portion of the slit is reinforced by a reinforcing plate from both front and rear sides. The bending accuracy of the lower table can be made parallel to the bending of the upper table by connecting the front and rear reinforcing plates with a connecting member penetrating the lower table, so that the processing accuracy can be improved at low cost. In the crowning device for a press brake according to the present invention, the substantially triangular reinforcing plate is provided at the lower side of the slit and above the round hole and at the center. By fixing the lower table in welding Rinohen, it is possible to reduce the stress generated in the vicinity of the round hole of the slit.

In the press brake crowning device according to the third aspect of the present invention, the reinforcing plates on both sides are connected by a connecting member penetrating the lower table so as not to contact the through-hole provided in the lower table. Can be reduced.

[Brief description of the drawings]

FIGS. 1A and 1B are a front view and a side view showing an embodiment of a crowning device for a press brake according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIGS. 3A and 3B are a front view and a side view showing a general press brake in which a slit is provided in a lower table.

FIG. 4 is an analysis diagram showing a stress state of a round hole at the tip of a slit of a lower table.

FIG. 5 is an analysis diagram showing a reinforcing plate attached to a lower table and a stress state around the reinforcing plate.

FIG. 6 is an analysis diagram showing a stress state generated when only a slit and a round hole are provided.

FIGS. 7A and 7B are a front view and a side view showing a conventional and more general press brake.

FIGS. 8A and 8B are explanatory views showing problems in a conventional press brake crowning device.

[Explanation of symbols]

 Reference Signs List 1 press brake 5U upper table 5L lower table 9 slit 11 crowning device 13 round hole 15 through hole 17 round bar (connecting material) 19 reinforcing plate P punch D die W work

Claims (3)

[Claims] 1. A press brake crowning apparatus for bending a work by cooperation of a punch attached to a lower end of an upper table and a die attached to an upper end of a lower table, wherein the apparatus comprises: A pair of reinforcements that connect the lower side of the slit provided on the lower table to make the deflection of the lower table parallel and the part near the center of the lower table from the round hole at the tip of this slit to reinforce both front and rear surfaces of the lower table A crowning device for a press brake, comprising: a plate; and a connecting member penetrating through the lower table to connect the pair of reinforcing plates. 2. The reinforcing plate has a substantially triangular shape as a whole, and a lower side of the slit and a side closer to the center above the round hole and fixed to the lower table by welding. The crowning device for a press brake according to claim 1, wherein: 3. The crowning device for a press brake according to claim 1, wherein the connecting member penetrates the lower table so as not to contact a through hole provided in the lower table.