JPH01197013A - Holding device to follow work for thrust bending - Google Patents

Abstract

PURPOSE:To improve working accuracy and to prevent position deviation of a work by providing load holding springs to hold weight of a table and the work in a swinging device of the table and disposing a shock absorber in the table swinging cylinder. CONSTITUTION:A base frame 2 and the table 3 are provided reciprocatively and an air cylinder 28 to swing the table 3 at the time of working a punch 9 is disposed. Further, the load holding spring 28 holding the weight of the table 3 and the work perfectly in the first stage of working the punch 9 is provided and a cushion chamber is disposed at the opposed side of the pressure chamber of the air cylinder 28. In the first stage of working the work between the punch 9 and a die 5, the load of the cylinder 28 is initiated from zero, the spring 29 quickens the operation of the air cylinder 28 and reduces as progressing the working. Because the shock at finishing the work is lightened by the cushion chamber, the working accuracy is improved and the position deviation of the work is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a workpiece follow-up support device for projecting bending, and particularly to a workpiece whose swing speed is gradually reduced in accordance with the descending speed of a ram. Workpiece tracking for projecting bending that allows the table that supports the workpiece to follow the workpiece to improve machining accuracy, and also prevents the workpiece from shifting when the table is returned to the horizontal position after machining is completed. Relating to a support device.

[Prior art and its problems]

Conventionally, when bending heavy workpieces such as steel plates, it is necessary to prevent the workpiece from being bent around the shoulder of the die due to its own weight or inertia during processing, and to remove the processed workpiece from the press. In order to safely take out the workpiece, a workpiece following and supporting device is provided that supports the workpiece that swings outside the die during processing by following the swinging motion of the workpiece.

In the conventional workpiece tracking support device for projecting bending, a base frame is provided in front of the press bed, a table with a flat top surface is provided above the base frame, and the top surface of this table is fixed on the bed. The rear part of the arm, which swings around the front lower part of the base frame, is formed so that its forward extension line points toward the die, and the arm is guided to the rear part of the arm. The table is supported so as to be movable toward the die through means, and a position regulating means is provided for regulating the distance between the table and the die to a constant value when the arm and table swing, thereby controlling the machining operation of the ram of the press, i.e. The punch supported by the ram is configured to move the table up and down via the arm by the swing drive means in conjunction with the movement of the ram while the punch is bending the workpiece.

Usually, the swing drive means includes a cylinder mounted between a base frame and an arm. Although the driving source for the cylinder is not particularly limited, it is advantageous to use compressed air with low viscosity as the driving source in order to make the cylinder expansion speed as fast as possible.

By the way, if the workpiece is viewed as one rigid body, the swinging speed of the workpiece changes depending on the descending speed of the ram.

For example, in a friction press, the descending speed of the ram reaches its maximum at the top dead center, is decelerated in proportion to the descent of the ram, and becomes zero at the bottom dead center. In addition, in a projecting bending machine where the ram is driven via a slider crank mechanism such as a press brake, the descending speed of the ram is maximum at the intermediate height, and below the intermediate height there is a sign for changes in the ram height. The speed decreases in a curved manner and reaches zero at bottom dead center. Further, after the punch attached to the ram comes into contact with the upper surface of the descending object, the resistance due to work hardening increases as the ram descends, and the machining speed of the ram tends to be reduced more rapidly. in short,
The descending speed of the punch is at its maximum when the punch and workpiece come into contact, and after that it gradually decelerates and eventually stops at the bottom dead center. It reaches the maximum, then gradually decelerates and reaches zero at the end of machining.

On the other hand, the air cylinder does not expand during the precompression period from the start of supply of working fluid until the internal pressure of the cylinder rises above the weight of the arm, table, and workpiece at the beginning of processing. Therefore, by setting the timing at which the supply of working fluid to the cylinder starts prior to the timing at which the punch contacts the workpiece by the preload period, the start of cylinder extension and the contact of the punch at the workpiece can be synchronized. Can be done. However, the preload period needs to vary depending on the weight of the workpiece, and the timing at which the punch contacts the top surface of the workpiece varies depending on the thickness of the workpiece. It is extremely difficult to match the timing of the start of cylinder extension with the timing when the punch contacts the top surface of the workpiece by adjusting the timing of the start of supply of working fluid to various workpieces with different plate lengths and shapes. .

Therefore, in the conventional workpiece following support device for projecting bending,
In the early stages of machining, the table's upward movement may be slow or slow for a workpiece that is moving up and down at high speed, causing the workpiece to be bent by the shoulder of the die or the table, or catching up with the workpiece during the upward movement. There is a problem in that the table collides with the workpiece, causing the workpiece to vibrate and shift the machining position.

Further, the cylinder expands at a constant speed depending on the amount of working fluid such as compressed air supplied, and even if the supply of compressed air is stopped when the cylinder is stopped, it tends to further expand due to the dynamic inertia of the arm and table. This expansion of the air cylinder due to inertia is usually prevented by mechanically restricting the stroke of the air cylinder by providing a suitable stopper inside or outside the cylinder. In this way, when mechanically restricting the extension of the cylinder, the table is stopped with an impact at the upper limit of the rise, and the workpiece is thrown forward from the table due to inertia, which impairs machining accuracy. Jiru.

Furthermore, after the machining is completed, the workpiece and the table are returned to the horizontal position, and in this case, conventionally, a suitable stopper is provided inside or outside the cylinder to stop the cylinder from being shortened. Similarly, when the table is shortened and stopped, there is a problem in that the table is stopped with an impact, the workpiece jumps up on the table due to the reaction, and the position of the workpiece is shifted.

The present invention has been made in consideration of the above circumstances, and improves machining accuracy by making a table supporting the workpiece follow the workpiece whose swing speed is gradually reduced in accordance with the machining speed of the ram. It is an object of the present invention to provide a workpiece tracking and supporting device for projecting bending, which is capable of increasing the height of the workpiece and also prevents the workpiece from being displaced when the table is returned to the horizontal position after the workpiece is finished.

[Means for solving problems]

In order to achieve the above object, the workpiece tracking support device for projecting bending according to the present invention includes a base frame provided in front of the bed of the press, a table with a flat top surface provided above the base frame, and a table with a flat top surface provided above the base frame. The table is positioned at approximately the same height as the top surface of the die fixed on the bed, and the rear part of the arm that swings around the front lower part of the base frame is formed so that its forward extension line faces the die. The table is supported at the rear of the arm via a guide means so as to be movable toward the dice, and a position regulating means is provided for regulating the distance between the table and the dice to a constant value when the arm and the table swing. In a workpiece follow-up support device for projecting bending, which is configured to cause a table to be upwardly oscillated via an arm by a oscillating drive means in conjunction with the machining operation of a ram of a press, the oscillating drive means is configured to upwardly oscillate a table via an arm. It is characterized by the provision of a support spring that supports the weight of the table and workpiece at the start of driving, a cylinder that swings the arm and table upward, and a cushion means that cushions the shock when the cylinder stops extending.

[Effect]

According to the present invention, when the cylinder starts to extend, the weight of the table and workpiece is supported by the support spring, so the load on the cylinder is zero, and the cylinder starts to expand at the same time as the working fluid is supplied to the cylinder. Decompression begins.

Therefore, by simply adjusting the timing of starting the supply of working fluid to the timing when the punch contacts the workpiece, which is determined according to the thickness of the workpiece, the timing of starting machining and the timing of the start of upward swinging of the table can be easily adjusted. can be matched.

In addition, at the beginning of machining, the weight of the arm, table, and workpiece is supported by the support spring, and as the support spring extends, the load on the cylinder increases, so the cylinder extension speed reaches its maximum at the beginning of extension. After that, the speed will be gradually reduced.

Further, when the cylinder is fully extended and stopped, the shock at the time of stopping the extension is buffered by the cushioning means, so the arm and table are stopped smoothly and the workpiece can be prevented from being thrown off the table.

In addition, when the table is returned to the horizontal position after machining, the weight of the arm, table, and workpiece is supported by the support spring, and the cushioning action of this support spring cushions the shock when the arm, table, and workpiece stop. Thus, the arm, table, and workpiece can be stopped smoothly. As a result, it is possible to prevent the workpiece from jumping up on the table due to the reaction of stopping, and it is possible to prevent the workpiece from being displaced.

In the present invention, the structure of the cushioning means is not particularly limited as long as it can buffer the shock when the cylinder fully extends and stops; however, in order to reduce the number of parts and simplify the structure, The space defined by the piston on the opposite side of the pressure receiving chamber is closed off as a cushion chamber, and the internal pressure of the cushion chamber, whose volume decreases as the cylinder expands, is configured to buffer the shock when the cylinder stops expanding. is advantageous.

In this case, it is optional whether or not the cushion chamber is communicated with the atmosphere when the cylinder is shortened. It is also possible to insert a spring for the cushion into the cushion chamber and use the internal pressure of the cushion chamber and the elasticity of the spring to buffer the shock when the extension stops. Furthermore, a spring for the cushion may be inserted into the cushion chamber which is constantly communicated with the atmosphere, and the shock at the time of stopping the extension may be buffered by the buffering action of this spring. In addition, it is also possible to insert the support spring into the pressure receiving chamber of the cylinder.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 11.

FIG. 1 is a longitudinal sectional side view of a workpiece tracking and supporting device for a press brake according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the operation of the arm and table, and FIGS. The figures are schematic side views showing the operation of the press brake workpiece following support device in order during deep bending,
FIG. 1θ is a timing diagram showing the relationship between the operation timings of each part, and FIG. 11 is a compressed air circuit diagram of the swing drive device. ' This workpiece tracking support device includes a table 3 with a flat top surface above a base frame 2 placed in front of a press brake 1, and moves the base frame 2 and table 3 to a forward position and a backward position by a forward/backward drive means 7. It is designed to be able to be driven back and forth between positions.

In the retreat position, as shown in FIG. 3, a workpiece W such as a steel plate is placed on the table 3 at a predetermined position, for example, from a carry-in conveyor (not shown), or a processed workpiece is placed on the table 3 as shown in FIG. W is transferred from the table 3 to, for example, an unillustrated carry-out conveyor. Further, in the forward position, the processing position of the workpiece W is located on the mold center line of the press brake 1, as shown in FIGS. 4 to 7.

The forward/backward driving means 7 may be configured to be able to move the base frame 2 and the table 3 forward and backward between forward and backward positions, and here, as shown in FIG. The other end is supported by the lifting drive means 6
An air cylinder 24 connected to the base frame 2 through
The forward and backward drive means 7 is constituted by these. This advance/retreat movement guide device 25 rotates with a pair of left and right guide rails 26 made of channel steel provided in the pit 20 and on both left and right sides of a base frame of the advance/retreat movement guide device 25 at appropriate intervals in the front and rear direction. It is composed of front and rear pairs of guide rollers 27 that are freely provided and freely roll within each guide rail 26.

The base frame 2 and table 3 are provided above a lifting drive means 6 which is driven forward and backward by a forward and backward drive means 7 together with them.

The elevating drive means 6 may be configured to be able to move the base frame 2 and the table 3 in parallel in the vertical direction. Here, the elevating drive means is a pantograph type table lifter that can obtain high parallel movement accuracy with a simple structure. 6 is composed.

In addition, the lifting/lowering driving means 6 moves the table 3 to a reference position H0 where the lower surface of the workpiece W placed thereon is at the same height as the upper surface of the die 5, and a position where the processed workpiece is placed on the processed groove 11 of the die 5. The structure may be such that the object W is raised and lowered over the mold release position H1 where the object W is lifted, but here, as shown in FIG. As shown in FIG. 8, the table 3 is configured to be able to be lowered to a lower level layer lower than the reference position in conjunction with the advance/retreat drive means 7 so that the die 5 can be pulled out obliquely backward and downward.

Furthermore, after the table 3 places the unprocessed workpiece W and moves to the forward position, the ram 8 and punch 9 are lowered, and after the punch 9 comes into contact with the upper surface of the workpiece W, the plate bending process is started. Until the end of the punch 9 stops descending, the fifth
From the horizontal position where the top surface of the table 3 is horizontal as indicated by the arrow A in FIG. 5 or FIGS. As indicated by arrow B in the figures and FIG. It has become.

Further, as shown in FIG. 5, the table 3 starts to move up the ram 8 and the punch 9 after the plate bending process is completed, and the workpiece W taken out from the press brake 1 is returned to the retreat position and then shaken. The eighth position is moved from the inclined position by the dynamic drive means 10.
It is then returned to the horizontal position as shown in the figure.

When the table 3 swings between the horizontal position and the swinging position, it is kept at a constant distance from the ridgeline 12 by the position regulating means 13.

The swing driving means 10 swings the table 3 upward between a horizontal position and an inclined position via an arm 14 that is swingably supported at the lower front side of the base frame 2 via a fulcrum shaft 35. Air cylinder 28 that can be driven, arm 14 at the beginning of machining,
It includes a support spring 29 that completely supports the weight of the table 3 and the workpiece W, and a compressed air circuit 38 that supplies compressed air to the air cylinder 28.

This compressed air circuit 38, as shown in FIG.
0. The compressed air is pressurized by the accumulator 41, the pulsation is removed by the accumulator 41, and the pressure is adjusted by the pressure setting valve 42. The resulting compressed air is supplied to the pressure receiving chamber 44 of the air cylinder 28 via the electromagnetic on-off valve 43, and The pressure receiving chamber 44 can be communicated with the atmosphere via the on-off valve 45.

A cushion chamber 4''7 is formed in the air cylinder 28, which is partitioned by the piston 46 on the opposite side of the pressure receiving chamber 44, and this cushion chamber 47 is provided with a solenoid valve while the piston 46 is at the bottom dead center. 48, and is sealed by closing the solenoid valve 48 from before the piston 46 starts moving from the bottom dead center toward the top dead center until it returns to the bottom dead center again. There is.

The arm 14 is formed into a substantially V-shape when viewed from the side so that its rear extension line faces the dice 5, and the table 3
is supported at the rear of this arm 14 via guide means 15 so that it can move forward and backward toward the dice 5. Then, as the swing angle α of the table 3 from the horizontal position increases, the distance between the arm 14 and the die 5 decreases, and the position regulating means 13 moves the table 3 to the rear of the arm 14. On the other hand, by moving the table 3 in a direction away from the dice, the distance between the table 3 and the ridge line 12 can be kept constant.

The position regulating means 13 may be configured to hold the table 3 at a certain distance from the ridge line 12 of the die 5, but here, in order to avoid increasing the size of the workpiece tracking support device, the above-mentioned a pair of position regulating plates 31 fixed to the table 3 at appropriate intervals in the left-right direction and having an arc-shaped position regulating groove 30 centered on the ridge line 12;
A pair of position regulating pins 32 that are slidably fitted into each position regulating groove 30 and fixed to the base frame 2, and a table 3.
The weight reduction mechanism 33 reduces the weight of the table 3 that is gradually applied to the position regulating pin 32 as the swing angle α of the table 3 increases. This weight reduction mechanism 3
3 is a position regulating pin 3, although it is not essential to the present invention.
By reducing the weight of the table 3 supported by the table 2, the diameter of the position regulating pin 32 is reduced, thereby reducing the size of the position regulating groove 30 and the position regulating plate 31. There is no particular limitation as long as the structure is such that the weight of the table 3 supported by the table 3 can be reduced. Here, when the intermediate part is pivotally supported by the arm 14, the upper end part is pivotally connected to the front lower side of the table 3 and slidably in a direction perpendicular to the top surface of the table 3. It consists of a link lever 34 and a tension coil spring 36 that pulls the lower end of the link lever 34 toward the fulcrum shaft 35 of the arm 14.

The guide means 15 includes a guide rail 16 fixed in the table 3 at an appropriate interval in the left and right direction, and an arm 14.
It is composed of two pairs of guide rollers 17 rotatably supported on both left and right sides of the rear part of the rollers, respectively, at an appropriate interval in the front-rear direction. These guide rollers 17 are the guide rail 1
The table 3 is held at a fixed distance from the ridgeline 12 of the die 5 by the position regulating means 13, and the rear part of the arm 14 is pushed up by the swinging drive means 10 to swing it from a horizontal position to an inclined position. When the table 3 is moved, the table 3 moves forward within the guide rail 16 as it retreats from the rear of the arm 14.

In the first half of the guide rail 16, the guide roller 17 on the side closer to the die 5 of the front and rear guide rollers 17 transferred inside the guide rail 16 is set at a table third inclination angle α over a predetermined swing angle range of the arm 13. A curved guide portion 18 is provided that displaces the arm 14 downward so that the swing angle β is smaller than the swing angle β of the arm 14. The guide roller 17 is formed in a downwardly convex arc shape so that as it moves forward while rolling within the guide roller 16, the amount of downward displacement of the guide roller 17 gradually increases and then decreases.

Incidentally, suction devices 19 are provided on the table 3 at appropriate intervals in the front-rear direction and the left-right direction in order to fix the workpiece W placed on the table 3 to the table 3.
The upper surface of each suction device 19 that protrudes upward from the upper surface of the table 3 forms a following surface 20 that causes the workpiece W to follow. In FIG. 2, the top surface of the table 3 is shown as the follow-up surface 20 for the sake of simplicity.

The suction device 19 may be configured to be able to suction and fix the workpiece W placed thereon, and for example, an electromagnet or a vacuum suction device can be used. Here, each suction device 19 is constituted by a vacuum suction device that can suction and fix the workpiece W regardless of the strength of magnetism. These suction devices 19 are started when the punch 9 has completely descended, and then operate until the ram 8 and punch 9 are raised, and the workpiece W is taken out of the press brake 1, and the table 3 is returned to a horizontal position. controlled as follows.

Note that the table 3 has a part of the workpiece W further tilted than the tilted position so that the lightweight deeply bent workpiece W can be tilted further further than the tilted position and can be taken out by retreating from the bus brake 1 without contacting the punch 9. It is designed to allow a large incline.

That is, the table 3 is divided into a main table 21 that supports the guide rail 17 and auxiliary tables 22 on both the left and right sides of the main table 21, and the main table 21 and the auxiliary tables 22 are pivotable relative to each other via the fulcrum pin 18. While connecting,
An air cylinder 19 is mounted across the lower side of the main table 21 and the lower side of the auxiliary table 22. Then, with the table 3 in the inclined position, the air cylinder 19
When extended, the auxiliary table 22 is raised to an upright position where the angle of inclination is greater than the tilted position, as indicated by arrow C in FIG.

The suction device 19 is attached to an auxiliary table 22 in order to fix the workpiece W to the table 3 between an inclined position and a horizontal position.
It is supported by

Although not shown, on the top surface of the auxiliary table 22, a free conveyor equipped with a large number of rotatable balls is installed as necessary to facilitate the loading and unloading of the workpiece W onto the table 3. provided.

Further, when the table 3 is swung from a horizontal position to an inclined position, the center of gravity of the table 3 moves forward and the weight of the table 3 acts to lift the rear part of the base frame 2, but the lifting drive means 6 Pressing spring 3 connected to the base frame of
7 counteracts the weight of the table 3 and prevents the base frame 2 from tilting forward.

Next, the procedure of plate bending using the press brake 1 equipped with the workpiece following and supporting device configured as described above and the operation of the workpiece following and supporting device will be explained.

First, in the workpiece loading process in which the workpiece W is placed on the table 3, the base frame 2 is placed in the retracted position, the table 3 is placed in the horizontal position, and the mold release position H It is difficult to raise the temperature.

For example, the workpiece is transferred to table 3 by a conveyor (not shown).
When the transfer is completed to the predetermined position above, the air cylinder 24 of the advance/retreat drive means 7 is activated based on a command given to the control means by the operator or a control program incorporated in the control means.
is extended to move the base frame 2 to the forward position, and as shown in FIG. 4, the processing position of the workpiece W is positioned on the center line of the die 5 and punch 9 of the press brake 1. Thereafter, based on a command given to the control means by the operator or a control program incorporated in the control means, the press brake l of the workpiece W is lowered to the reference position H0 as shown in FIG. Setting is completed. In the subsequent press working process, the ram 8 is lowered based on a command given to the control means by the operator or a control program built into the control means, and when the punch 9 comes into contact with the upper surface of the workpiece, the ram 8 is driven to swing. Means 10 are activated.

In this workpiece following support device, the weight of the arm 14, table 3, and workpiece W is supported by the support spring 29 at the initial stage of plate bending, so the air cylinder 2
The load on the air cylinder 28 at the time of starting the supply of compressed air to the air cylinder 8 is zero, and the expansion of the air cylinder 28 is started simultaneously with the start of the supply of compressed air. Therefore, the timing of starting processing determined by the thickness of the workpiece W, that is, the punch 9
The start of machining and the start of upward swinging of the table 3 can be easily synchronized by simply timing the start of supply of compressed air with the time when the table 3 contacts the top surface of the workpiece W.
Ru.

In addition, since the punch 9 is driven by a motor (not shown) via a slider crank mechanism (not shown), the acceleration of the punch 9 reaches its maximum at the midpoint of the vertical stroke, then decreases in a sine curve shape, and downwards. It becomes zero at dead center. In addition, the load applied to the punch 9 is relatively small at the initial stage of sheet bending, and as the process progresses, work hardening progresses and the load applied to the punch 9 increases, and the downward speed of the punch 9 becomes even slower. Become. Therefore, the descending speed of the punch 9 is fast at the beginning of machining, and as the machining progresses, the descending speed of the punch 9 becomes slow (the swing speed of the workpiece outside the die 5 corresponds to the descending speed of the punch 9). It is fast at the beginning of machining and becomes slower as machining progresses.

On the other hand, the proportion of the weight of the arm 14, the table 3, and the workpiece W being shared by the support spring 29 gradually decreases between the time when the air cylinder 28 starts to extend and the time when the support spring 29 is fully extended. As the air cylinder 28 is shortened, the cushion chamber 47 is closed, because the resistance to the expansion of the air cylinder 28 gradually increases, and because the cushion chamber 47 is closed just before the air cylinder 28 starts to expand. As the volume of the air cylinder 28 decreases and its internal pressure increases, the expansion speed of the air cylinder 28 is gradually slowed down, so the expansion speed of the air cylinder 28 reaches its maximum at the start of non-resistance expansion, and is gradually decelerated thereafter. .

Air cylinder 2 whose extension speed is gradually reduced in this way
Since the table 3 is raised and swung by the punch 9
The oscillation of the table 3 can be made to follow the oscillation of the workpiece W whose oscillation speed is gradually reduced as the oscillation speed is lowered,
The workpiece W lifts up from the following surface 20, and the workpiece W is plastically deformed at the ridge line 12 of the die 5 due to its own weight and inertia, or the workpiece W vibrates on the table 3, causing the machining position to change to the metal position. This can prevent it from shifting from the center of the mold.

When the air cylinder 28 reaches its maximum length, the air in the cushion chamber 47 acts as a cushion and absorbs the shock when the air cylinder 28 stops expanding, so that the upward swinging of the table 3 is stopped smoothly. This prevents the table 3 from jumping out of the follow-up surface 20 due to inertia when the table 3 stops swinging upward, thereby preventing loss of machining accuracy.

In addition, since the workpiece W is actually not a rigid body but an elastic plate, at the beginning of the process when the workpiece W suddenly starts to swing, the part of the workpiece W near the die 5 is 5
0 It oscillates as the part oscillates between the shoulders, but the die is 5.
In the part far away from the following surface 2 due to static inertia and own weight
Trying to stay at 0. As a result, the workpiece W is elastically deformed and bent upward in a convex arch, and the swing angle of the workpiece W outside the die 5 is the same as the swing angle of the workpiece W between the shoulders of the die 5. smaller than the angle.

On the other hand, in this workpiece tracking support device, the arm 14
The guide roller 17 of the guide rail 160 curve guide part 1
8, the table 3 is further displaced downward by the arm 14, and the swing angle α of the table 3 is reduced from the swing angle β of the arm 14, as indicated by the arrow B° in FIG. The swing angle of the follow-up surface 20 is adjusted to the swing angle of the workpiece W, which becomes smaller as it moves away from the workpiece W,
Thereafter, as indicated by arrow B in FIG.
is displaced above the table 3 by the punch 9.
The swing angle of the follow-up surface 20 is adjusted to the swing angle of the workpiece W that is the same as the swing angle of the workpiece W near the die 5. As a result, the elastic deformation of the workpiece W at the initial stage of machining causes the workpiece W to move toward the following surface 2.
The workpiece W does not rise from zero, and due to such lifting of the workpiece W, the workpiece W is plastically deformed at the ridge line 12 of the die 5, or vibrates on the follower surface 20, causing the machining position to shift from the center of the mold. This prevents them from doing so.

When the punch 9 pushes the workpiece W down to the bottom of the processing groove 11 of the die 5 and the plate bending process is completed, the table 3 is positioned at an inclined position as shown in FIG. An object W is fixed to a table 3. After this, the ram 8 and punch 9 are raised based on a command given to the control means by the worker or a control program incorporated in the control means, and then a command given to the control means from the worker or the control means The process of taking out the workpiece W is started based on the control program incorporated in the seventh
As shown in the figure, the table 3 is raised to the mold release position H by the lifting drive means 6, and the workpiece W is lifted onto the processing groove 11 and released from the mold. Next, when the bending depth of the workpiece W is small, the air cylinder 24 of the advance/retreat drive means 7 is shortened to move the base frame 2 and table 3 back to the retreat position, or the swing drive means 10 The workpiece W is taken out from the press brake 1 by returning the table 3 to the horizontal position and then shortening the air cylinder 24 of the advance/retreat drive means 7 to retract the base frame 2 and table 3 to the retracted position. Further, if the bending depth of the workpiece W is large and the workpiece W collides with the punch 9 when the workpiece W is moved backward, the air cylinder 24 of the forward/backward drive means 7 is used to prevent this collision. By operating the elevating drive means 6 in synchronization with the shortening of pass diagonally through the space of the low position H
Lower it to L. Thereafter, based on a command given to the control means by the operator or a control program incorporated in the control means, the air cylinder 24 of the advance/retreat drive means 7 is further shortened to retract the base frame 2 and table 3 to the retracted position. and then returned to the horizontal position.

When the table 3 is returned to the horizontal position, the pressure receiving chamber 44 of the air cylinder 28 is communicated with the atmosphere, and the air cylinder 28 is shortened by the weight of the arm 14, the table 3, and the workpiece W. Then, the arm 14, the table 3, and the workpiece W
The weight of is gradually shared by the support spring 29, and when the table 3 is returned to the horizontal position and the shortening of the air cylinder 28 is stopped, the weight of the arm 14, the table 3, and the workpiece W is no longer applied to the air cylinder 28. . The cushioning action of the support spring 29 buffers the shock when the air cylinder 28 shortens and the downward swinging motion of the arm 14, table 3, and workpiece W stops, and the arm 14, table 3, and workpiece W Stops smoothly. This prevents the workpiece W from jumping up from the table 3 due to reaction when stopped, and prevents the workpiece W from being displaced due to this jumping up.

Furthermore, the table 3 is raised to the mold release position H by the lifting drive means 6, and the base frame 2 and table 3 are returned to the same position as shown in FIG. 3, as shown in FIG.

Then, the processed workpiece W is removed from the table 3 at the position of
One cycle of the cannibal program is completed by transferring it to a delivery conveyor (not shown).

Note that the Kani program is not particularly limited to the order of operation of each part as described above; for example, when the bending depth of the workpiece W is shorter than the stroke of the punch 9,
Without raising the table 3 to the mold release position, the table 3 is returned from the tilted position B to the horizontal position A by the swing drive means 10 in synchronization with the rise of the punch 9, and then the forward/backward drive means 7
The workpiece W may be taken out from the press brake 1 by shortening the air cylinder 24 . In addition, after taking out the deep bending workpiece W from the press brake l, the table 3
The order of retracting to the retracted position, returning to the horizontal position, and raising to the mold release position may be interchanged with each other (or may be performed simultaneously,
In the above procedure, the carry-in position and carry-out position of the workpiece W are the same, but these carry-in positions and carry-out positions can be set arbitrarily, and these carry-in positions and carry-out positions can be made different. is also possible.

〔Effect of the invention〕

As described above, according to the present invention, the weight of the arm, the table, and the workpiece is supported by the support spring at the start of machining, and the load on the cylinder of the swing drive means becomes unloaded. The cylinder starts to extend at the same time as the working fluid is supplied to the cylinder. As a result, the timing diagram for the start of machining determined according to the thickness of the workpiece can be easily created by simply timing the start of supply of working fluid to the cylinder with the timing when the punch contacts the top surface of the workpiece. The start of the upward swing and the start of machining can be synchronized. In addition, from the start of machining until the support spring is fully extended, a portion of the weight of the arm, table, and workpiece that is shared by the cylinder gradually increases, so as machining progresses, the downward speed of the punch is reduced. The cylinder's extension speed is gradually reduced in response to this, and the table can be made to follow the swinging workpiece in response to the downward movement of the punch. Furthermore, when the extension of the cylinder is stopped, the shock caused by the stop of extension is buffered by the cushion means, and the upward swinging movement of the table is smoothly stopped.

In this way, the table swing can be made to follow the swing of the workpiece from the start of machining to the end of machining, which prevents the workpiece from lifting off the table. Improves machining accuracy by preventing plastic deformation of the workpiece at the edge of the die or contact area with the table, vibration of the workpiece on the follow-up surface, shifting the machining position, and loss of machining accuracy. be able to. - Also, since the upward swing of the table can be stopped smoothly, it is possible to prevent the workpiece from moving away from the table due to inertia when the table stops rising and swinging.

In addition, when returning the table to the horizontal position, the downward swing of the table can be smoothly stopped by the cushioning action of the support spring, so that when the table stops swinging downward, the workpiece will not jump up from the table due to the reaction of the stop. Misalignment can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of a press brake workpiece tracking support device according to an embodiment of the present invention, Fig. 2 is an explanatory view showing the operation of the arm and table, and Figs. 3 to 9 are deep bending Each schematic side view showing the operation of the press brake workpiece tracking support device during processing in sequence, FIG. 10 is a timing diagram showing the relationship between the operation timings of each part, and FIG. 11 is a compression diagram of the swing drive device. It is an air circuit diagram. In the figure, W...Workpiece, 1...Press brake (press), 2...Base frame, 3...Table, 4...Bed, 5...Dice, 8...Ram , 10・
... Swinging drive means, 13... Position regulating means, 14... Arm, 15... Guide means, 28...
- Air cylinder (cylinder), 29... Support spring, 47... Cushion chamber (cushion means).

Claims (1)

[Claims] (1) A base frame is provided in front of the bed of the press, a table with a flat top is provided above the base frame, and this table is positioned at approximately the same height as the top surface of the die fixed on the bed, The rear part of the arm that swings around the front lower part of the base frame is formed so that its forward extension line faces the die,
A table is supported at the rear of the arm via a guide means so as to be movable toward the die, and a position regulating means is provided for regulating the distance between the table and the die to a constant level when the arm and table swing. In the workpiece tracking support device for projection bending, the workpiece tracking support device for projecting bending is configured to upwardly swing the table via the arm by a swinging drive means in conjunction with the machining operation of the ram, wherein the swinging drive means is configured to swing the table up and down via the arm. The projector is characterized by being provided with a support spring that supports the weight of the table and the workpiece at the start, a cylinder that swings the arm and the table upward, and a cushion means that buffers the shock when the cylinder stops extending. Workpiece tracking support device for bending.