JPH04279217A - Press brake - Google Patents

Abstract

PURPOSE:To reduce the deformation generated on a side plate guiding an upper table and to minimize the moment load. CONSTITUTION:An upper table 5 is moved vertically to a lower table and a press brake bending a work W by the cooperation of a punch P and a die D is characterized in that a driving device 9 to lower this upper table 5 is mounted on the lower part of a frame 3 or on a lower table 7 and the upper table is lowered by this driving device 9 to the lower part.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to press brakes.

0002

2. Description of the Related Art Two types of conventional press brakes are known: a lower table raising type and an upper table lowering type.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional press brake, whether the lower table is raised or the upper table is lowered, the pressing force is applied in the direction of widening the gap between the side plates (frames). This causes the side plate that guides the upper table to bend. If this is repeated, distortion will occur in the side plate, causing displacement of the side plate in the front-rear direction, which poses a problem in terms of processing accuracy.

In other words, the deflection of the side plate is the product P×l of the force P applied to the punch on the upper table and the distance l between the punch on the upper table and the driving center of the punch, and l is large as long as it is received by the side plate. Due to the increased size and stress, the side plates will harm the guiding function of the upper table.

The purpose of this invention is to improve the above-mentioned problems by reducing the deformation that occurs in the frame (side plate) that guides the upper table, and by minimizing the rotational moment and improving the machining accuracy. To provide a press brake in which the frame can be made thinner and smaller.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a lower table with a die fixed to the upper end of the frame, and an upper table with a punch corresponding to the die fixed to the lower end. A drive device is provided on the upper part of the frame to move the upper table up and down with respect to the lower table to bend the workpiece by working with a punch and die, and to lower the upper table. A press brake was provided at the bottom of the frame or at the bottom table.

[0007]

[Operation] In the press brake of the present invention, a lower table with a die fixed to the upper end is provided at the lower part of the frame, an upper table with a punch corresponding to the die fixed to the lower end is provided at the upper part of the frame, and the lower table is connected to the lower table. The workpiece is bent by moving the upper table up and down and working together with the punch and die. At this time, since a drive device for pulling down the upper table is provided at the bottom of the frame or on the lower table, the upper table is pulled down by this drive device, so that a problem occurs on the side plate that guides the upper table. Deformation is less than before.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show an example of the press brake in this embodiment, with FIG. 1 showing a side view and FIG. 2 showing a front view. 1 and 2, the press brake 1 mainly includes a frame 3, an upper table 5, a lower table 7, a drive device 9, a ball screw 11, and a guide device 13.

The frame 3 has C-shaped side plates 15, 15 made up of two vertically elongated rectangular plates facing each other, and both sides 15 thereof.
.

The upper table 5 is provided at the upper part of the frame 3, and has a plate shape that hangs downward. A punch P is attached to the lower end of the upper table 5 via an intermediate plate 19, and is detachably provided.

The lower table 7 is fixed to the lower part of the frame 3 and extends upward to form a plate shape, and a die holder 21 is provided at the upper end of the lower table 7 in correspondence with the punch P of the upper table 5. A die D is provided so that it can be attached and removed freely, and press work is performed in which the upper table 5 is moved up and down and the punch P and die D work together to bend the plate material (workpiece) W. .

The drive device 9 is formed by an AC servo motor 23 provided on both sides of the frame 3, a timing belt device 25, and a transmission device 27.

A belt 39 runs endlessly between the main pulley 31 fixed to the motor shaft 29 of the AC servo motor 23 and the driven pulley 37 correspondingly fixed to the gear shaft 35 of the gear box 33. The power of the AC servo motor 23 is transmitted to the transmission device 27 .

That is, this power is transmitted through the engagement between the main gear 31 and the driven gear 37, and then is transmitted to the threaded portion 43 of the nut 41.
As a result, the ball screw 11, which is erected perpendicularly to the collar 45, is rotated through the collar 45 provided above.

A ball screw nut 49 is screwed onto a screw 47 provided at the upper end of the ball screw 11, and the ball screw nut 49 is screwed by the rotation of the ball screw 11.
rotates and moves up and down to the position shown in phantom lines in FIG. As the guide device 13, bolts 51 are attached to the side plate 15.
The mounting plate 55 is fitted into a linear guide 59 mounted with bolts 57. Moreover, the lower part of the mounting plate 55 is fixed by a pin 61 with the ball screw nut 49.

With the above configuration, the upper table 5 is smoothly moved up and down by the rotation of the ball screw 11 via the rail 53 and along the linear guide 59 of the mounting plate 55. That is, as the ball screw nut 49 moves up and down, the upper table 5 moves up and down via the mounting plate 55 as described above.

The upper table 5 is thus lowered, and the punch P and die D of the upper table 5 cooperate to bend the work W as described above.

Since the embodiment of the present invention is constructed as described above and operates as described above based on the construction, there is no tilting of the side plate 15 of the frame 3, and therefore there is little deformation. Furthermore, since no vertical pressure is applied to the side plates 15, the side plates can be made thinner and smaller.

It should be noted that the present invention is not limited to the embodiments described above, but can be implemented in other embodiments by making appropriate changes.

For example, in this embodiment, as shown in FIG. 2, the gear box 33 is fixed to the side plate 15 of the frame 3 with bolts. As shown, the gear box 33 may be attached directly to the lower table 7. With this configuration, the side plate 15 only functions as the guide device 13, so its intention becomes clear.

[0022]

Effects of the Invention As can be understood from the above description of the embodiments, since the present invention has the configuration as described in the claims, the driving device provided on the frame or the lower table can By pulling the upper table from below, the inclination of the side plates of the frame is reduced,
Deformation of the frame can be reduced.

Furthermore, by providing a base on the lower table that is pulled from the bottom by the above drive device, or placing it as close as possible to the lower table, it is possible to further reduce the inclination of the side plate, and since no vertical pressing force is applied to the side plate, the side plate can be made thinner. Since it can be made smaller, it is possible to save labor on materials.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of a press brake according to the present invention.

FIG. 2 is a front view of FIG. 1.

FIG. 3 is a schematic side view of another embodiment of the present invention.

[Explanation of symbols]

1 Press brake 3 Frame 5 Upper table 7 Lower table 9 Drive device P Punch D Die

Claims (1)

[Claims] 1. A lower table with a die fixed to the upper end is provided at the bottom of the frame, an upper table with a punch corresponding to the die fixed to the lower end is provided at the upper part of the frame, and the upper table is moved vertically with respect to the lower table. A press brake that bends a workpiece by collaborating with a punch and a die, and is characterized in that a drive device for lowering the upper table is provided at the lower part of the frame or at the lower table. .