JPH06344033A - Press brake robot system - Google Patents

Abstract

PURPOSE:To bent an arbitrary work and together to bend it with excellent production efficiency. CONSTITUTION:A compliance mechanism which is interposed between a hand to hold a work and a robot arm, and changes between a 1st state that the hand is in a fixed state against the robot arm and a 2nd state that the hand is movable against the robot arm is provided. At the time of positioning the work with respect to the press brake and taking out the work from the press brake, the hand is kept in holding state and the compliance mechanism is made in the 1st state. A controlling means performs control so that during bending the work, the hand is kept in holding state and the compliance mechanism is made in the 2nd state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a press brake for bending a work, and a robot for moving a hand holding the work according to the movement of the end of the work when the work is bent. Press brake robot system.

[0002]

2. Description of the Related Art A press brake has a die having a V groove and a punch that moves up and down, and a work placed on the die is bent by lowering the punch or raising the die to fold the work. In recent years, a system in which a robot is used to bend and perform work supply and removal for the press brake is becoming widespread.

In the press brake robot system in which the press brake and the robot are combined as described above, the work is moved immediately after the bending of the next side in order to prevent the work from being bent due to a sudden jump of the work during bending. In order to be able to perform the above, the hand is made to follow the movement as the work end portion rises as the work is bent.

During this follow-up operation, if the work is held while being held by the hand, the bending itself will be adversely affected unless the work is accurately followed along the locus of the end of the work. Since complicated calculations are required to find each rising trajectory, conventionally, the hand follows the workpiece with an appropriate trajectory with the workpiece separated, and re-grasps the workpiece after bending the side. Was there.

For this reason, the gripping position of the workpiece changes every time the bending of the side is completed. Therefore, conventionally, the work is positioned by pressing the work against two NC-controlled backstops each time the negative side is bent.

[0006]

However, the method of positioning the work by the backstop has a dimension that cannot be positioned by the backstop, such as when bending a work having a width shorter than the distance between the two backstops. It could not be applied to a shaped work.

Further, in the system in which the work is positioned by the backstop, the work is pressed on the backstop by moving the work on the die, so that the edge of the work is caught in the die. There was a problem of lowering the operating rate of the system.

In addition, 1/4 to 1/3 of the price of a normal NC press brake is currently spent for the backstop portion and the control device therefor, and the backstop is expensive. There is a problem.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a low-cost press brake robot system capable of bending an arbitrary work and capable of bending with high production efficiency. To aim.

[0010]

According to the present invention, there is provided a press brake for bending a work by sandwiching the work with a die and a punch and applying a pressing force, and when the work is bent between the punch and the die. In a press brake robot system including a robot that causes a hand holding the work to follow the movement of the end of the work, the hand is inserted between the hand holding the work and the robot arm, and the hand is attached to the robot arm. On the other hand, the compliance mechanism that switches between the first state in the fixed state and the second state in which the hand can move with respect to the robot arm, and the positioning of the work with respect to the press brake and the removal of the work from the press brake are described above. The hand is maintained in the gripped state and the compliance mechanism is set to the first The state, the middle of the workpiece bending so as comprising a control means for was and the compliance mechanism maintains the hand in gripping state to said second state.

[0011]

According to the present invention, the robot hand keeps gripping the same place during bending. And during the bending process,
The compliance mechanism provided between the hand and the robot arm allows the hand to move with respect to the robot arm, thereby eliminating the need for accurate follow-up operation.

That is, in the prior art, since the work is re-gripped each time the side is bent, the position at which the work is gripped shifts each time the side is bent. Since the robot continues to grasp the same position of the work, once the robot is correctly positioned, the relative position of the robot and the work does not change. Therefore, the back stop for positioning the work is unnecessary.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings.

FIGS. 2 and 3 show an example of a press brake robot system according to the present invention. A press brake 10 has a fixed table 3 having a die 2 supported on the upper side and a punch 1 on the lower side. It has a movable table 4 and the like which is supported on and moved up and down. In this case, the robot 20 uses a robot having a joint structure as shown in FIG. That is, the robot 20 includes a slide rail 22 for moving the base portion 21 in parallel to the press brake 10, a first shaft 24 for rotating the first arm 23 in the front-rear direction, and a second arm 25 for the front-rear direction. The second shaft 26 for rotating the third arm 27 in the left-right direction, the fourth shaft 30 for rotating the fourth arm 29 in the front-back direction, and the fourth arm 29 for rotating the left-right direction. And a suction shaft 32 at the tip of the arm.

In other words, if a normal vertical articulated robot is used, it is difficult to obtain the absolute position accuracy of the robot tip position. In this case, therefore, the front-back direction, which is important for positioning with respect to the press brake, is emphasized. The robot having the above-described joint structure is used so that the positioning can be performed on four or less axes independently of other axes.

In FIG. 2, reference numeral 40 denotes a carry-out table and 50
Is a destacker, 60 is a brake pendant, and 70 is a robot controller.

FIG. 5 shows the detailed construction of the suction hand 32. The suction hand 32 is capable of moving the suction pad 33 in the three-dimensional directions of up, down, front, back, left and right by a compliance mechanism.

That is, the shaft 3 supporting the suction pad 33.
4 is movable in the vertical direction with respect to the housing 37 by springs 35 and 36, and a disk-shaped space 38 is formed in the housing 37.
Then, the disc portion 40 of the center unit 39 is fitted and inserted in the void 38. The diameter of the disk portion 40 is 38
Since it is set smaller than the inner diameter of
Is movable to the front, rear, left and right with respect to the center unit 39. Further, the housing 37 is formed with a recess 43 into which the piston 42 of the air cylinder 41 is fitted, and when the piston 42 is not fitted into the recess 43, the housing 37 has a center unit 39.
However, when the piston 42 is fitted in the recess 43, the housing 37 cannot move with respect to the center unit 39.

That is, in this compliance mechanism, the compliance in the front-rear and left-right directions is fixed by extending the air cylinder 41, and the compliance in the front-rear and left-right directions is set free by shortening the air cylinder 41. This fixed / free switching is performed by the robot controller 70.

FIGS. 6 and 7 show a state in which the suction hand 32 is used for bending. The suction pad is directed upward in the case of FIG. 6 and the suction pad is moved in the case of FIG. Facing downwards.

A procedure for performing a bending process using the above structure will be described with reference to FIG.

First, the robot arm is appropriately moved so that the work W placed on the destacker 50 is sucked by the suction pad 33. At this time, the compliance mechanism is in a fixed state.

When the work is adsorbed on the destacker 50, it is not released until it is ejected onto the carry-out table 40 thereafter. That is, the suction pad 33 continues to hold the same position even during the bending process.

Next, the work W is inserted into the press brake 10 by driving the robot 20, and then the punch of the press brake 10 is lowered (FIGS. 1 (a) (b)).

While the punch is being lowered, the robot 20 is driven to position the work W at a predetermined position on the die of the press brake 10. However, the press brake 10 is not provided with a back stop, and positioning is performed by the accuracy of the robot itself (FIG. 1 (c)).

After this positioning, the punch descends to the position of the work W, and the work W is sandwiched by the punch and the die (FIG. 1 (d)).

When the work is sandwiched between the punch and the die in this way, the robot controller 70 issues a command to switch the compliance mechanism of the suction hand 32 of the robot 20 from the fixed state to the free state. This allows the suction pad 33 of the suction hand 32 to freely move with respect to the robot arm.
(FIG. 1 (e)) After that, when the work W is bent by the pressurization of the punch, the suction hand 3 is accompanied by this bending.
2 drives the robot arm to follow it (Fig. 1 (f)). Since the compliance mechanism is in a free state during this follow-up operation, it is not necessary for the robot arm to draw an accurate trajectory corresponding to the rising of the workpiece, and a somewhat rough trajectory may be used.

After that, when the bending process for this side is completed, the punch is raised (FIG. 1 (g)). Thereafter, the work W is lifted by a command from the robot controller 70, the compliance mechanism is switched from the free state to the fixed state, the work is taken out of the press brake 10, and the procedure shifts to the bending of the next side ( Figure 1
(h) (i) (j)).

When the bending on all sides is completed,
The work is transferred to and placed on the unloading table 40.

As described above, in this embodiment, after the work is once held, it is not released until the bending of all sides is completed, so that it is not necessary to position the work by the back stop.

Although the robot having the joint structure as shown in FIG. 3 or 4 is used in the above embodiment, a robot having another joint structure such as a normal 6-axis vertical multi-joint robot is used. You may do it.

Further, in the above embodiment, the suction hand is used as the robot hand, but a normal grip type hand may be used. Of course, even when the grip type hand is used, an appropriate compliance mechanism is provided. When using a grip type hand, 1
Since it becomes impossible to bend one side, it may be possible to place it at an appropriate positioning station between the bending steps and change the holding at this positioning station. Further, the compliance mechanism is not limited to that shown in the embodiment, and a compliance mechanism having an arbitrary structure may be adopted.

By the way, in the above embodiment, a folding and bending die as shown in FIG. 8 may be used as a die for bending the work. When such a folding and bending die is used, a follow-up operation at the time of bending is unnecessary, so that the joint structure of the robot can be made simpler. FIG. 9 shows an example of a joint structure of a robot when a folding bending die is used. In the robot of FIG. 9, one axis is configured to be slidable up and down and four rotation axes are provided.

[0034]

As described above, according to the present invention,
During the bending process, the robot's hand keeps gripping the same place, and during the bending process, the compliance mechanism provided between the hand and the robot arm enables the hand to move with respect to the robot arm. Positioning can be performed even if it is omitted, and it is not necessary to perform a follow-up operation based on an accurate trajectory, and bending of an arbitrary work can be performed with good production efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing a bending step in an embodiment of the present invention.

FIG. 2 is a plan view showing a press brake robot system.

FIG. 3 is a side view showing a press brake robot system.

FIG. 4 is a diagram showing a joint structure of a robot.

FIG. 5 is a sectional view of a suction hand.

FIG. 6 is a view showing a state of a robot hand when bending a work.

FIG. 7 is a diagram showing a state of a robot hand when bending a work.

FIG. 8 is a view showing a folding bending die.

FIG. 9 is a diagram showing an example of a robot used when a folding bending die is used.

[Explanation of symbols]

 10 ... Press brake 20 ... Robot 32 ... Suction hand 33 ... Suction pad 40 ... Delivery stand 50 ... Disstacker 70 ... Robot controller

Claims (2)

[Claims] 1. A press brake for bending a work by sandwiching the work with a die and a punch and applying a pressing force, and with a movement of an end portion of the work when the work is bent between the punch and the die. In a press brake robot system including a robot that follows the hand holding the work, the first brake is interposed between the hand holding the work and the robot arm, and the hand is fixed to the robot arm. And a second state in which the hand is movable with respect to the robot arm, and a hand is held in the gripping state when positioning the work with respect to the press brake and removing the work from the press brake. When the compliance mechanism is set to the first state, Press brake robot system comprising a control means for controlling so that was and the compliance mechanism maintains the hand in gripping state to said second state during. 2. The press brake robot system according to claim 1, wherein the hand is a suction hand that sucks and supports a work.