JP3737859B2 - Bending press - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a press that performs bending of a plate material with a pair of molds (punch and die) that perform an approaching movement, and more particularly to a press mainly called a linear bending process called a brake press or the like. .
[0002]
[Prior art]
A press called a brake press, which is mainly used for straight bending of plate materials, has as its main components a frame, a ram, a lifting drive for the ram, and a material positioning device called a back gauge. It has. The frame is a C-shaped side that connects the upper table, the lower table, and the upper and lower tables located on both sides of the machine on the front (worker side) of the machine. The frame is used as a main component. The upper table, the lower table and the ram are usually formed of a wide and thick plate on the left and right, and the ram is a vertical guide provided on both sides of the upper table (upper drive machine) or the lower table (lower drive machine). It is driven up and down along. A punch and a die are mounted on the ram and the table facing the ram, and the plate material inserted between the punch and the die is bent along the folding line in the left-right direction of the machine by the lifting and lowering operation of the ram. The back gauge is located behind the punch and the die, and the plate material is positioned by bringing the back end of the plate material into contact with the back gauge.
[0003]
Conventionally, hydraulic cylinders have been mainly used as ram lifting drive devices, but the structure driven by a combination of servo motors and ball screws has the advantage that ram positioning can be performed accurately and easily. Therefore, it is increasingly used mainly for small machines. In the case of a large machine, the lifting drive is arranged at both ends of the ram. In the case of a small machine, only one lifting drive is arranged at the center of the ram.
[0004]
There are various sizes of workpieces to be machined, and various machining accuracy is required. In order to process a large workpiece, it is a matter of course that a large machine is required, and the lateral width dimensions of the ram and the table must be increased. On the other hand, a processing reaction force acts on the table or ram, and bending distortion occurs in the ram or table due to the frame structure in which both ends of the table are fixed by side frames. This bending strain is proportional to the cube of the width dimension of the ram or table. Due to bending distortion of the ram or table, the gap between the punch and die during workpiece machining differs at both ends and the center of the workpiece, causing a phenomenon called so-called center sagging and reducing workpiece machining accuracy. Let
[0005]
As a means to correct table and ram distortion due to processing reaction force, a structure is used in which the height of the mold is adjusted with a wedge material, or the fixed mold is received with a floating structure to follow the deformation of the frame. However, such a means makes the setup work prior to the machining of the workpiece very troublesome, requires skill from the operator, and increases the setup time and decreases the productivity.
[0006]
Another machine distortion that reduces machining accuracy is side frame deflection. Since the side frame exists only on the back side of the table, a force that pulls the upper table and the lower table apart due to the processing reaction force causes the side frame to bend. The C-shaped notch provided in the side frame enables machining of a workpiece exceeding the arrangement interval dimension of the side frame, and allows the workpiece to be inserted into the machining area from the side of the machine. Increasing the size of the notch lengthens the arm length of the bending moment applied to the side frame and reduces the depth dimension of the side frame that is effective in resisting bending, which greatly increases the side frame deflection. Become. Therefore, the C-shaped notch provided in the side frame should be as small as possible, and both side frames can be provided at the side edges of the machine to take a wide space behind the table, and the workpiece can be bent deeply into this space. It has a structure.
[0007]
Although it is possible to process a small work with a large press, it is disadvantageous in terms of factory space efficiency and equipment efficiency. On the other hand, it is usually impossible to process a large workpiece with a small press. Therefore, in general press factories, large, medium and small presses are installed, and production plans are made so that processing is performed most efficiently. However, since the types of workpieces fluctuate, a small press plays with a large number of large workpieces, and a small workpiece must be machined with a large press when a large number of small workpieces increase.
[0008]
When processing a small workpiece with a large press, attach a plurality of dies with different processes to the ram and the table facing it, and move the workpiece in the horizontal direction. Processing is also performed. However, even if such a means is adopted, it is usually difficult to simultaneously insert a plurality of workpieces into a plurality of installed dies, and even if a plurality of dies are mounted, one step at a time. Processing is normal and does not improve work efficiency.
[0009]
A press apparatus that performs automatic processing by arranging a robot or a conveyor for transporting a workpiece in front of the machine is known. If multiple press molds are mounted on a single press, installing a robot according to the number of processes and inserting and removing workpieces from the press in synchronization can improve work efficiency. it can. However, in a normal configuration in which robots are arranged in front of the press, two robots must be arranged on the front of the machine when performing two processes simultaneously, and three robots when performing three processes simultaneously. It is not practical in terms of robot installation space and cost. Even if only one robot is installed on the front of the machine, in the case of a small lot, the processing efficiency may be reduced due to the setup of the robot. Therefore, the workability of the setup work such as adjusting the stroke of the ram and the height of the mold while performing the test bending is greatly reduced.
[0010]
[Problems to be solved by the invention]
In view of the various problems of the conventional bending press described above, the present invention firstly improves work efficiency when processing a small workpiece with a large press, thereby reducing the size of a small workpiece with a large press. The first problem is to eliminate the decrease in space efficiency and equipment efficiency when machining the steel. Secondly, it eliminates the processing accuracy degradation and difficulty of setup work caused by bending of rams, tables and side frames, which is a problem with large presses. Third, it can process multiple processes with a single press. It is an object to obtain an effective arrangement structure of a robot for transferring a workpiece that is particularly effective when performed simultaneously.
[0011]
[Means for Solving the Problems]
The main components of the present invention are an upper table 1 and a lower table 2 positioned on the front surface of the machine, and a C-shaped side frame 5 connecting the upper table 1 and the lower table 2 behind both ends of the machine. The present invention relates to a bending press provided with a frame to perform.
[0012]
The bending press according to claim 1 of the present invention includes one or a plurality of back frames 6 connecting the upper and lower tables 1 and 2 behind the tables 1 and 2 between the two side frames 5. The width of the machine corresponds to the arrangement of the C-shaped notch 7 provided in the back frame 6 with a size that does not prevent the workpiece from being inserted and swinging during processing of the inserted portion, and the side frame 5 and the back frame 6. A plurality of rams 3 that are divided in the direction and individually guided to be lifted, a plurality of lifting drive devices 10 that individually lift and lower each of the divided rams 3, and a plurality of lifting drive devices that are individually controlled And a switching means 25 for switching the plurality of elevating drive devices 10 to individual control and synchronous control. With this configuration, the first problem is achieved.
[0013]
A bending press according to a second aspect of the present invention includes the matter described in the first aspect, and is further divided by a lifting stroke correcting means 22 provided individually for each lifting driving device corresponding to each divided ram. And a gauge 16 for detecting the relative displacement between the tables 1 and 2 in each portion corresponding to each ram 3, and the correction means of the lifting drive device 10 for the ram according to the measured value of the gauge 16 corresponding to each ram 3. 22 correction values are set. With this structure, the first problem and the second problem are both achieved.
[0014]
As a specific example of the gauge 16, the relative displacement between the distal end of the C-shaped gauge frame 15 whose base end is fixed to one of the tables 2 and the distal end is brought close to the other 1 and the other table 1 is linear scale. A structure that detects the difference between one of the tables 1 and 2 with a laser length measuring device, etc., or a structure that measures the displacement of both tables 1 and 2 with a measuring device mounted on a frame to obtain the difference And so on.
[0015]
The bending press according to claim 3 is a bending press provided with the above items, and the function of the back gauge in the space between the back frames 6 behind the divided ram 3 or between the back frame 6 and the side frame 5. The robots 30 and 40 are arranged so that the robots 30 and 40 move the hand 36 horizontally in the extending direction of the tables 1 and 2, and a hand 36 that holds the workpiece behind the tables 1 and 2. Drive mechanisms 32 and 33 are provided.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show a first embodiment of the present invention. The upper table 1 and the lower table 2 are formed by a single thick plate having a large left-right width dimension, and a ram 3 divided into four in the width direction is fixed to the upper table 1 on the front surface of the upper table 1. It is guided by the guide 4 and is mounted so that it can be raised and lowered individually. The upper table 1 and the lower table 2 are integrally connected by a side frame 5 at both ends and a back frame 6 provided behind the dividing position of the ram 3.
[0017]
The back frame 6 has a side surface shape equal to that of the side frame 5, and the C-shaped notch 7 provided in the side frame 5 and the back frame 6 is a large notch that does not hinder the insertion of the workpiece having the maximum processing size. Therefore, the side frame 5 and the back frame 6 are flexibly bent (jaw opening phenomenon) due to the processing reaction force.
[0018]
The ram 3 divided into four is provided with a lifting drive device 10 for each ram. The lifting drive shown in the figure has a structure in which the rotation of an AC servo motor 11 is connected to a nut member 14 of a ball screw 13 by a timing belt 12. The ball screw 13 is erected on the top side of the ram 3. 1 is mounted so as to be rotatable and axially immovable. Therefore, the ram 3 is driven up and down via the ball screw 13 by rotating the AC servo motor 11 forward and backward.
[0019]
In the vicinity of the two side frames 5 and the three back frames 6, a C-shaped gauge frame 15 is fixedly provided on the lower table 2. The upper end of the gauge frame 15 is in a position close to the back surface of the upper table 1, and a linear scale 16 is attached to a portion where the tip of the gauge frame 15 and the back surface of the upper table 1 face each other.
[0020]
As described above, because the C-shaped notches 7 of the side frame 5 and the back frame 6 are enlarged, the side frame 5 and the back frame 6 are bent by the processing reaction force, and the upper table 1 is displaced upward. On the other hand, since no external force acts on the gauge frame 15, the tip end of the gauge frame 15 is not displaced. Therefore, the relative displacement of the upper table 1 relative to the lower table 2 is detected by the linear scale 16.
[0021]
A controller 21 is provided in each of the four lifting drive units 10 provided for each of the divided rams, and a stroke signal of this controller passes through the correction means 22 and the AC servo motor 11 of each lifting drive unit. Is given to. Detection signals of the linear scales 16 on both sides of the AC servomotor 11 to be controlled are input to each correction unit 22. The correction unit 22 drives the AC servo motor 11 by adding the average value of the deflection detected by the linear scales 16 on both sides to the stroke amount given from the controller 21.
[0022]
That is, if the upper table 1 is displaced upward by, for example, 0.2 mm due to the processing reaction force, the displacement is detected by the linear scale 16, and the correcting means 22 is set to 0.2 mm in the stroke amount given from the controller 21. The AC servo motor 11 is driven by adding the corresponding amounts. Accordingly, the displacement of the upper table 1 is always corrected by the correcting means 22, and the gap between the punch 23 and the die 24 when the ram 3 is lowered is always accurately maintained at the value commanded by the controller 21. It becomes.
[0023]
Since the linear scale 16 detects not only the deflection of the side frame 5 and the back frame 6, but also the deflection of the lower table 2 and the upper table 1, the gap between the punch 23 and the die 24 is controlled in the horizontal direction of the table by the above control. Is also maintained substantially constant.
[0024]
That is, in the above apparatus, a plurality of rams divided in the width direction of the table are corrected and stroked according to the amount of displacement of the table at each position. But it can be bent accurately without causing sagging.
[0025]
Changeover switches 25a, 25b, and 25c are provided between the controller 21 and the correction means 22 except for the rightmost side in FIG. In the illustrated state in which the selector switches 25a, 25b, and 25c are tilted to the left in the figure, the four controllers 21 individually control the four AC servomotors 11, and the ram 3 divided into four is Performs each independent operation. Therefore, if a die having a different process is attached to each of the four rams 3, one large press can be used as four small presses.
[0026]
On the other hand, when all of the switches 25a, 25b, and 25c in FIG. 4 are switched to the right side in the figure, all four AC servo motors 11 are synchronously controlled by the rightmost controller. In this state, the same mold is attached to the four rams 3 and they are simultaneously operated to process a wide range of large workpieces.
[0027]
Further, according to the switching circuit shown in FIG. 4, the right and left rams can be operated synchronously by switching the right end switch 25a and the left end switch 25c to the right side. Also, by tilting the two right switches 25a and 25b to the right, the three right rams operate synchronously and the leftmost one ram operates individually. If only the right switch 25a is tilted to the right, the two rams on the right side operate synchronously, and the two rams on the left side individually operate. By switching the control of the elevating drive device that drives each of the rams thus divided, one press can be used as a plurality of presses appropriately according to the width of the work, and the work to be processed with the equipment It is possible to avoid a decrease in productivity due to a mismatch with the dimensions of Even when the press is used in any manner, since the stroke amount is corrected for each ram by the correcting means 22 in accordance with the deflection of the mounting position of each ram, it is possible to always ensure accurate bending.
[0028]
A robot 30 that also serves as a back gauge is mounted in the space between the back frames 6 behind the divided rams 3 or between the back frame 5 and the side frames 6. The robot 30 includes a guide bar 32 that is long in the left-right direction and can be moved and positioned along a guide frame 31 in the front-rear direction of the machine, which is disposed in the approximate center of the space behind each ram 3. The guide bar 32 is provided with a carrier 33 that is reciprocated by a rodless cylinder, a motor-driven feed screw, or the like, and the hand 36 is connected to the carrier 33 via links 34 and 35 having joints around a horizontal axis. It is installed.
[0029]
The hand 36 has a finger 37 that can be opened and closed. When the hand 36 is used as a robot, the hand 36 grips and conveys the workpiece. When used as a back gauge, the links 34 and 35 are folded, the hand 36 is directed forward, and the finger 37 is opened. The work insertion depth is determined by positioning the guide bar 32 on the guide frame 31. The work is positioned by the rear edge of the work inserted from the front of the machine hitting the surface of the hand 36 facing forward.
[0030]
The operation of the robot 30 when the four steps are performed by one machine while the molds of the first to fourth steps are respectively attached to the four rams 3 and the workpiece is sequentially transferred is as follows. is there.
[0031]
First, when the bending process in the first step is completed, the carrier 33a moves to the right side in FIG. 1, and the finger 37 grips the workpiece at that position. Then, the workpiece is lifted from the die, and the carrier 33a moves to the left, thereby conveying the workpiece to the left side. At this time, the robot carrier 33b adjacent to the left side moves to the right, and the hand grips the left half portion of the work fed from the right side. Then, the fingers of the right robot 30a are opened and the left robot carrier 33b is moved to the left, so that the workpiece is transferred to the position of the mold in the second step. Two-step bending is performed.
[0032]
The finger of the second robot 30b opens just before the bending process is performed, and the carrier 33b moves to the right, and the hand of the second robot 30b grabs the right half of the workpiece for which the bending process in the second step has been completed. Then, the carrier 33b of the second robot moves to the left and transports the workpiece to the third step. By sequentially performing the above operations from the first robot 30a to the fourth robot 30d, bending in four steps is automatically performed.
[0033]
In the first embodiment described above, only the ram is divided in the width direction, but the table on the ram mounting side can be divided at the same time as the ram. In this case, each divided table must be held by two back frames or a back frame and a side frame.
[0034]
FIG. 6 shows a second embodiment having such a structure, in which the upper table 1 and the ram 3 are divided into three equal parts in the left-right direction of the machine. Each ram 3 is guided in the vertical direction on both sides of each upper table 1, and is provided with a lift drive device 10 similar to the first embodiment. Each of the divided upper tables 1 is connected to the lower table 2 by two back frames 6 or back frames 6 and side frames 5.
[0035]
The mounting position of the back frame 6 and the side frame 5 is the portion inside the both ends of the upper table 1, whereby the bending distortion of the upper table 1 is distributed on the plus side and the minus side, thereby reducing the absolute value. can do. Although not shown in the drawing, in the second embodiment as well, the C-shaped notches 7 of the back frame 6 and the side frame 5 are notched so as not to hinder the machining of the workpiece, and thus occur. The increase in the bending of the frames 5 and 6 is corrected by detecting the displacement of the upper table 1 as in the first embodiment. The gauge frame 15 and the gauge 16 for this correction are provided adjacent to the back frame 6 and the side frame 5.
[0036]
In the space behind each of the divided rams 3, the robot 40 similar to that described in the first embodiment is arranged. The guide bar 32 of the robot 40 in the second embodiment is provided with a guide frame 31. Is fixed to the tip of an arm 43 that can be rotated around a vertical pivot pin 42 and telescopically and telescopically. The robot 40 according to the second embodiment can perform a workpiece transfer operation similar to that described in the first embodiment, and turns the arm 43 90 degrees around the turning pin 42 while moving the slider 41 forward. By doing so, the work can be reversed and sent to the next process.
[0037]
FIG. 6 is a plan view for explaining the workpiece transfer operation by the robot 40 of the second embodiment. After the finger 37 grips the workpiece in the state indicated by the solid line in the drawing, the slider 41 moves forward (moves downward in the drawing). The arm 43 is rotated 90 degrees to the right while the arm 43 passes through the C-shaped notch 7 of the back frame 6, and the two back frames 6, 6 adjacent to the tip of the guide bar 32 of the robot 40 are adjacent to each other. It moves in the state rotated 90 degrees between. Therefore, the robot arm of the next process is rotated in the opposite direction so that the robot of the previous process and the robot of the subsequent process face each other, deliver the workpiece, and then move the arm 43 back while moving the slider 41 of both robots backward. The workpiece is transferred to the next process in a state where the workpiece is inverted 180 degrees.
[0038]
FIG. 7 is a side view showing a state of the robot when gripping the end portion of the bent work, and FIG. 8 is a side view when the robot is used as a back gauge.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a first embodiment. FIG. 2 is a sectional side view of the same. FIG. 3 is a perspective view showing details of a gauge for measuring the displacement of an upper table. FIG. 5 is a schematic plan view showing the second embodiment. FIG. 6 is an enlarged plan view of the robot of the second embodiment. FIG. 7 is a side view of the robot of the second embodiment. Side view of the main part when using as a back gauge [Fig. 9] Perspective view showing the frame structure of a conventional bending press [Explanation of symbols]
1 Upper table 2 Lower table 3 Ram 5 Side frame 6 Back frame
10 Lifting drive
15 gauge frame
16 Linear scale
21 Controller
22 Correction means
25 selector switch
30 robot
32 Guide bar
33 Career
36 hands
40 robot

Claims (3)

Upper table (1) and lower table (2) located at the front of the machine, and C-shaped side frame (5) connecting the upper table (1) and the lower table (2) at the back side of both ends of the machine In a bending press equipped with a frame whose main component is
One or more back frames (6) connecting the upper and lower tables (1), (2) behind the tables (1), (2) between the two side frames (5) A C-shaped notch (7) provided in the back frame (6) with a size that does not prevent the workpiece from being inserted and swung during processing of the inserted portion, and the side frame (5) and the back frame (6) A plurality of rams (3) divided in the width direction of the machine corresponding to the arrangement and individually guided for raising and lowering, and a plurality of raising and lowering drive devices (10) for individually raising and lowering each of the divided rams (3) ), A control device (21) for individually controlling each of the plurality of lifting drive devices, and a switching means (25) for switching the plurality of lifting drive devices (10) to individual control and synchronous control, Processing press. Elevating stroke correction means (22) individually provided in each elevating drive device (10) for raising and lowering each divided ram (3), and a table in each part corresponding to each divided ram (3) A gauge (16) that detects the relative displacement between (1) and (2), and correction of the lift drive device (10) of the ram according to the measured value of the gauge (16) corresponding to each ram (3) The bending press according to claim 1, wherein a correction value of the means (22) is set. A robot (30, 40) with a back gauge function is placed in the space between the back frame (6) and the back frame (6) and the side frame (5) behind the divided ram (3). The robot (30, 40) has a hand (36) that holds the workpiece behind the table (1, 2), and a transport that moves the hand (36) horizontally in the extending direction of the table (1, 2). The bending press according to claim 1 or 2, further comprising a drive mechanism (32, 33).

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