JP2003311337A - Bender - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact bender for reducing noise, preventing an oil leakage, and requiring no piping space in a hemming device to fold an edge part of a work by pressing a bending blade against the work. <P>SOLUTION: The bending blade is provided in an advancing/retracting manner to an edge part of a work W via a parallel link mechanism 12, and the bending blade is pressed against the edge part of the work by using an electric driving device 41 with an electric motor 41a as a drive source. A control device to control the number of rotation and the output torque of the electric motor is included, the position of the bending blade is controlled based on the number of rotation, and the pressure of the bending blade to the edge part is controlled based on the output torque. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending apparatus suitable for hemming an edge of a panel component (hereinafter, simply referred to as a work) such as an automobile door panel or a hood panel.

[0002]

2. Description of the Related Art The applicant of the present application has variously improved a bending apparatus of this type. For example,
In Japanese Patent Laid-Open No. 2000-343156, processing units are installed at a plurality of locations around a lower die on which a work is placed, and the pressing force applied to the lower die corresponding to each processing unit (work bending There is disclosed a bending apparatus provided with a receiving mechanism that receives the pressing force applied by the processing unit from the lower die side. According to this bending apparatus, since a large pressing force applied to the lower die for bending is received by the receiving mechanism, the lower die does not need to have as large rigidity as before, and thus the lower die is not required. It has become possible to reduce the thickness and weight.

[0003]

However, the conventional bending apparatus described above has some points to be further improved. That is, in the above-described conventional bending apparatus, since the pressing force for pressing the bending blade against the edge of the work to bend the edge uses the hydraulic cylinder as the pressure source, the piping space is reduced. There is a problem in that the installation space for the bending apparatus is not only increased due to the necessity of securing the same, but also troubles such as oil leaks are likely to occur, and thus maintenance and the like for avoiding the troubles are troublesome. Further, even when the hemming process is not actually performed, the hydraulic oil needs to be fed to the hydraulic cylinder, which causes the power consumption of the hydraulic fluid feeder (hydraulic pump) as a hydraulic power source to be large, and the work caused by the noise. There was a problem that caused deterioration of the environment. The present invention has been made to solve such problems of the conventional bending apparatus, and provides a bending apparatus that does not use a conventional hydraulic cylinder as a drive source for pressing a bending blade. To aim.

[0004]

Therefore, the present invention is
The bending apparatus has the configuration described in each of the claims. According to the bending apparatus of the first aspect, the bending blade is pressed against the edge of the work, and the edge is bent in a folded shape, for example. Since the pressing force of the bending blade is made not by the conventional hydraulic cylinder but by an electric drive device using an electric motor as a drive source, various conventional problems when the hydraulic cylinder is used can be solved. That is, since the conventional hydraulic piping is unnecessary, the installation space of the bending apparatus can be reduced. Also, since there is no oil leak trouble like when using a hydraulic cylinder,
The maintenance work can be reduced. Further, since no hydraulic oil feeder (hydraulic pump) is required, not only power consumption can be saved, but also noise can be reduced and the working environment can be improved. According to the bending apparatus of claim 2, the position of the bending blade is controlled based on the rotation speed of the electric motor, and the pressing force of the bending blade is controlled based on the output torque of the electric motor. A more reliable bending process can be performed by absorbing a positional deviation or a positioning error. Further, according to the bending apparatus of the third aspect, in addition to the above-described function and effect, the output of the electric drive device can be amplified through the parallel link mechanism, so that a large pressing force of the bending blade can be obtained. it can.

According to the bending apparatus of the fourth aspect, in addition to the function and effect of the configurations of the first to third aspects,
Since the pressing force in the bending direction applied to the lower mold by the bending blade is received by the pressing force receiving device, it is possible to set the rigidity of the lower mold to be low, which enables the lower mold to be thin and lightweight. it can. According to the bending apparatus of claim 5, since the receiving arm is pressed in the anti-bending direction with respect to the lower mold in conjunction with the operation in which the bending blade is pressed against the edge portion of the work, the pressing tool added to the lower mold is pressed. The pressure can be reliably received by the receiving arm, and the pressing force receiving device can be surely functioned. According to the bending apparatus of claim 6, the edge of the work is bent in two stages of pre-bending and main bending, and since the bending blade is provided for each bending step, it is reliable and of high quality. Bending can be performed. In this specification, pre-bending refers to bending up to a bending position in the middle of reaching the final bending state of the edge of the work (for example, a position where an angle of about 45 ° remains until the folded state is left). This means bending to the final bending position (for example, a folded shape). Since the edge portion of the work is bent in two steps, that is, pre-bending and main bending, the spring back can be reduced and a high-quality bending work in a finished state can be performed. According to the bending apparatus of claim 7, the position of the bending blade is controlled based on the rotation speed of the electric motor in the preliminary bending step, and the bending blade position is controlled based on the rotation speed and the output torque of the electric motor in the main bending step. Since the position and pressing force are controlled, more reliable bending can be performed especially in the main bending process.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the entire bending apparatus H of this embodiment. In this embodiment, a so-called hemming device is illustrated as an example of the bending device H. Therefore, the hemming process is also simply referred to as bending process below. Accordingly, in the present embodiment, as an example of the work W, a door panel formed by joining the inner panel W1 and the outer panel W2 so as to overlap each other is illustrated. The inner panel W1 and the outer panel W2 are integrated by bending the edge W2a of the outer panel W2 of the work W into a folded shape by a bending apparatus H described below and sandwiching the edge W1a of the inner panel W1.

Now, as shown in FIG. 1, a plurality of (for example, four) pieces are provided on the upper surface of the base 1 in the bending apparatus H.
The lower die 2 supported by the supporting legs 2a to 2a of the is fixed. The lower mold 2 is made of, for example, a casting, and is formed in a substantially rectangular frame shape having an open central portion in a plan view. A lifter 3 that is moved up and down by an air cylinder 4 installed vertically on the base 1 is arranged in the center (space) of the lower mold 2. The lifter 3 can be moved up and down by mounting a work W on its upper surface. The work W is transferred to the lifter 3 by the operation of the robot hand R described later in a state where the lifter 3 is elevated to a position higher than the upper surface of the lower die 2. After the work W is transferred, when the lifter 3 is lowered to a position lower than the upper surface of the lower mold 2, the work W is transferred onto the lower mold 2 in the middle of the lowering. On the contrary, when the lifter 3 moves up while the work W is present on the lower mold 2, the work W is transferred to the lifter 3 and thus the work W is taken out from the lower mold 2. A work transfer jig 5 is attached to the tip of the robot hand R. The work transfer jig 5 has a function of clamping the work W and a function of pressing the work W against the lower die 2 as described below. On the lower surface of the frame 5a of the work transfer jig 5, pressing blocks 5b to 5b and clamp hangers are arranged at positions corresponding to a suitable number of positions (for example, four positions) around the work W.
The clamp hanger is omitted in the figure. This clamp hanger is provided so as to be movable back and forth by a cylinder. The work W is held in a suspended state along the lower surface side of the frame 5a by making this clamp hanger enter the lower side of the work W and pulling it up. When the clamp hanger is retracted, the work W is unclamped.
The pressing blocks 5b to 5b are brought into contact with the upper surface of the work W by the operation of the robot hand R, and are pressed against the work W by the operation force of the robot hand R in this contact state, whereby the work W is placed on the lower mold 2. It is fixed so that it can be pressed against. A positioning pin 6 for positioning the work W with respect to the work transfer jig 5 is provided on the lower surface of the frame 5a.

Next, FIGS. 2 and 3 show a main bending blade 20A, a preliminary bending blade 20B and a preliminary bending blade 2 which will be described later.
A hemming operation by 0B is shown. Figure 2
The preliminary bending step by the preliminary bending blade 20B is shown, and FIG. 3 shows the main bending step by the main bending blade 20A. The hemming process (preliminary bending process and main bending process) is a process in which the edge W2a of the outer panel W2 is folded back and crimped to the edge W1a of the inner panel W1, and the edge W1a of the inner panel W1 is Outer panel W that has been erected (flanged) at an angle of approximately 90 degrees in advance
As shown in FIG. 2, a pre-bending process for bending the edge W2a of the second part 2 in the folding direction up to an angle of about 45 degrees, and a book for further bending by 45 degrees and caulking as shown in FIG. It is performed in two steps, including bending.

The processing units 10 to 10 for performing such a hemming process are arranged at necessary locations around the lower die 2, that is, in the present embodiment, at three locations, namely the rear portion and the left and right portions. Each processing unit 10 has the same configuration. In FIG. 1, only one processing unit 10 on the left side of the drawing is shown. The configuration and processing operation of the processing unit 10 will be described below with reference to FIGS. 4 to 8. The processing unit 10 is roughly classified into a main bending blade 20A.
And an electric drive device 41 as a drive source for pressing the preliminary bending blade 20B against the work W, a toggle mechanism 31 operated by the electric drive device 41, and a parallel link mechanism 12 connected to the toggle mechanism 31. And receiving arm 21
And a bending blade switching mechanism 70 which is connected to the front end side of the parallel link mechanism 12 and which selects one of the main bending blade 20A and the pre-bending blade 20B for pre-bending and main-bending to switch their positions. .

First, the unit bracket 11 is fixed on the base 1 of the bending apparatus H in a state of standing upright. An electric drive device 41 is attached to the lower portion of the unit bracket 11. This electric drive device 41
Includes an electric motor 41a, a screw shaft 44 rotated by the electric motor 41a, and a nut 43 meshed with the screw shaft 44. The front end of the electric motor 41a is supported on the unit bracket 11 via a support shaft 42 so as to be vertically tiltable. Therefore, the electric drive device 41 is attached so as to be vertically tiltable via the support shaft 42. When the electric motor 41a is activated, the screw shaft 44 rotates and the nut 43 moves on the screw shaft 44. A so-called servo motor is used as this electric motor. This electric motor is equipped with a control device (not shown) for arbitrarily controlling (pulse control) the rotation direction, rotation speed, rotation speed, and the like. Also,
A load detection sensor 41b for detecting the output torque of the electric motor 41a is attached to the electric motor 41a. Based on the output torque detected by the load detection sensor 41b, the pressing force (bending force) of the main bending blade 20A and the preliminary bending blade 20B is controlled (torque control) by the control device.

Next, the toggle mechanism 31 is connected to the nut 43 via a connecting shaft 32. Toggle mechanism 31
Has two toggle links 33, 34. Both toggle links 33, 34 are rotatably connected to each other via the connecting shaft 32. Lower toggle link 34
A convex portion 55 is formed on the upper portion of the above, and a concave portion 54 is formed on the lower portion of the upper toggle ring 33 correspondingly. The toggle mechanism 31 extends in the extension direction (both toggle links 3
When the convex portions 55 come into contact with the side portions of the concave portions 54 by actuating in a direction in which 3, 34 are aligned with each other), the moving end in the extending direction is regulated. Upper toggle link 33
The front end side (upper end side in the drawing) of is connected to the parallel link mechanism 12. The parallel link mechanism 12 includes a pair of upper and lower links 13 and 14. Both links 13 and 14 are supported by unit bracket 11 via support shafts 15 and 16 so as to be vertically tiltable. The upper toggle link 3 is provided at the rear end of the upper link 13 via the connecting shaft 35.
The tip portions of 3 are rotatably connected to each other. on the other hand,
The rear end of the receiving arm 21 is rotatably connected to the tip of the lower toggle link 34 via a connecting shaft 36. The receiving arm 21 is attached to the lower portion of the unit bracket 11 via a support shaft 22 so as to be vertically tiltable. The tip end side (left end side in FIG. 4) of the receiving arm 21 reaches the lower surface side of the lower mold 2. A pressure plate 23 is fixed to the front end side of the receiving arm 21 so as to be able to contact the lower surface of the lower mold 2 with a slight gap therebetween. The parallel links 13 and 14, the receiving arm 2
1. The toggle links 33 and 34 are the unit bracket 1
Two sets are provided in the front-rear direction (the direction orthogonal to the plane of the drawing) between the vertical plates constituting one.

Next, the main bending blade 20 is provided between the tips of the upper and lower links 13 and 14 constituting the parallel link mechanism 12.
A bending blade switching mechanism 70 for selecting either A or the preliminary bending blade 20B and switching the mutual positions is attached. Details of the bending blade switching mechanism 70 are shown in FIGS.
Is shown in. Upper link 13 and lower link 14
Bending blade brackets 77 are rotatably connected between the tip ends of the two via connecting shafts 18 and 19, respectively. The bending blade bracket 77 is integrally provided with a fixed holder portion 77a for mounting the main bending blade 20A. The main bending blade 20A is attached to the front surface of the fixed holder portion 77a with the processing surface 20Aa thereof facing downward. The pre-bending blade 2 is provided below the fixed holder 77a.
A moving holder 73 for mounting 0B is arranged. The moving holder 73 is rotatably connected to the bending blade bracket 77 via a connecting bracket 74. One end of the connecting bracket 74 has a connecting shaft 71.
It is rotatably connected to the bending blade bracket 77 via. The other end of the connecting bracket 74 has a connecting shaft 7
It is rotatably connected to the moving holder 73 via 2.

A switching cylinder 76 is attached to the rear portion of the bending blade bracket 77 so as to be vertically tiltable via a connecting shaft 80. The tip of the rod of the switching cylinder 76 is connected to the moving holder 73 via the connecting shaft 75.
It is rotatably connected to the rear part. The connecting shaft 71,
72, 75, 80 correspond to the connecting portions of the four-bar link,
The inter-axis distance between the connecting shafts 71, 72, 75, 80 is set in advance so that the moving holder 73 moves in parallel along the arcuate locus as the switching cylinder 76 expands and contracts. Therefore, as shown in FIG. 7, when the switching cylinder 76 operates in the contracting direction, the connecting bracket 74 tilts counterclockwise in the drawing around the connecting shaft 71, and the moving holder 73 reaches the retracted position on the right side in the drawing. Move in parallel. When the movable holder 73 moves to the retracted position, the preliminary bending blade 20B attached to the moving holder 73 retreats from below the main bending blade 20A. As a result, the preliminary bending blade 20B is retracted to a position where it is not used for bending, and in this case, the main bending blade 20A attached to the fixed holder portion 77a is used for bending.

On the other hand, when the switching cylinder 76 operates in the extension direction as shown in FIG. 8, the connecting bracket 74 tilts in the clockwise direction in the figure around the connecting shaft 71, and the moving holder 73 moves to the left side in the figure. Move in parallel to the machining position of. As illustrated, when the movable holder 73 moves to the processing position, the preliminary bending blade 20B is positioned below the main bending blade 20A. In this state, the preliminary bending blade 20B is used for bending, and the main bending blade 20A is not used for bending. In this way, in the bending blade switching mechanism 70, the preliminary bending blade 2 is moved by expanding and contracting the switching cylinder 76.
It is possible to move 0B between the processing position where the main bending blade 20A is positioned below the main bending blade 20A and the retracted position where the main bending blade 20A is retracted from below, whereby switching between pre-bending and main bending is performed. It has become so. In the state where the preliminary bending blade 20B is located at the processing position, the preliminary bending blade 20B preliminarily bends the edge W2a of the work W, and when the preliminary bending blade 20B is located at the retracted position, the main bending blade 20B is located. The main bending of the edge W2a of the work W is performed by 20A. A stopper 79 is attached to the upper surface of the movable holder 73, and a stopper 78 is attached to the lower surface of the fixed holder 77a. When the movable holder 73 moves to the processing position by the extension operation of the switching cylinder 76, the stopper 79 contacts the stopper 78 from below, thereby positioning the movable holder 73 and adding it to the preliminary bending blade 20B. Bending force (reaction force of pressing force against the edge W2a of the work W)
Can be received.

According to the bending apparatus H of the present embodiment configured as described above, the actual hemming is performed as follows. In FIG. 1, the lifter 3 is lifted to a position higher than the upper surface of the lower mold 2, while the work W is clamped by the work transfer jig 5 and is transferred above the lifter 3 by the operation of the robot hand R. . After that, the clamp hanger of the work transfer jig 5 is retracted to the unclamp side and transferred onto the lifter 3.
The lifter 3 that has received the work W descends thereafter, and the work W is transferred onto the lower die 2 during the descending stage. After the work W is transferred onto the lower mold 2 in this way, the work transfer jig 5 is further lowered by the operation of the robot hand R, and the work holding blocks 5b to 5b are brought into contact with the work W. In this contact state, the work W is immovably pressed and fixed onto the lower mold 2 by the operating force of the robot hand R. Further, in this fixed state, the positioning pin 6 is inserted into the reference hole (not shown) of the inner panel W1 and the work W is positioned with respect to the lower die 2. This positioning state is maintained until the hemming process is completed. At this stage, the edge portion W2a of the outer panel W2 is bent by about 90 ° by the flange stand-up process performed in advance.
Next, three processing units 1 installed around the lower mold 2
Hemming processing by 0 to 10 is performed in synchronization. This hemming process is performed in two stages. First, the flanged edge W2a is folded back about 45 times.
Preliminary bending is performed to bend the edge W2a up to about 0 °, and then main bending is performed to completely bend the edge W2a to the folded state. First, preliminary bending is performed.
As shown in FIG. 8, the switching cylinder 76 of the bending blade switching mechanism 70 operates in the extending direction, and the preliminary bending blade 20B moves to a working position substantially directly below the main bending blade 20A.

FIG. 11 shows a control flow of the electric motor 41a. In this control flow, in step 1 (working waiting state), the "position command confirmation hold" signal is output from the control device and the electric motor 41a is stopped at the original position. Therefore, the preliminary bending blade 20B and the main bending blade 20B are stopped. 20A is located at a predetermined standby position. In step 2 (preliminary bending work start), a "motor rotation command" signal and a "speed command" signal are output from the control device to start the electric motor 41a in a predetermined rotation direction at a predetermined rotation speed. Thus, the electric motor 41 of the electric drive device 41
a starts, and the screw shaft 44 rotates to the machining side (screw shaft 44
Is rotated to the right if it is a right-hand screw), so that the nut 43 causes the screw shaft tip side (right side in FIG. 5, hereinafter referred to as processing side).
Move to. When the nut 43 moves to the processing side, the connecting shaft 32 of the toggle mechanism 31 is pushed to the processing side, and the toggle links 33 and 34 rotate about the connecting shaft 32, whereby the toggle mechanism 31 extends. . When the toggle mechanism 31 moves in the extension direction, the parallel link mechanism 12 tilts in the counterclockwise direction in the drawing, whereby the pre-bending blade 20
B descends toward the lower mold 2. The preliminary bending blade 20B descends and is pressed against the edge W2a of the work W, whereby the edge W2a is bent (preliminary bending) in the folding direction. The appearance of the processing unit 10 at this stage is shown in FIGS. 5 and 6. Also, by operating the toggle mechanism 31 in the extension direction,
In synchronization with the pre-bending process, the receiving arm 21 rotates in the clockwise direction in the figure with the shaft 22 as a fulcrum, whereby the pressure plate 23 attached to the tip of the receiving arm 21 is directed upward on the lower surface of the lower mold 2. The pre-bending pressing force is offset by the force. Since the pre-bending process is performed while the lower die 2 is supported by the receiving arm 21 from below as described above, the rigidity of the lower die 2 itself is not required so much. The descending end of the pre-bending blade 20B is controlled by appropriately controlling (pulse control) the rotation speed (output pulse) of the electric motor 41a by the control device. In this way, the cumulative number of rotations of the electric motor 41a is confirmed, and when the number of rotations reaches a preset number of rotations, a "motor rotation position confirmation command" signal is output from the control device, whereby the electric motor 41a is temporarily stopped ( Step 3 (preliminary bending work completed)). Subsequently, a "motor rotation command" signal and a "speed command" signal are output from the control device, and the electric motor 41a starts rotating in the reverse direction at a predetermined rotation speed, whereby the preliminary bending blade 20B is returned upward ( Step 4 (return to standby position)).

After the preliminary bending blade 20B is returned to the standby position in this way, the main bending process is performed. The set state of the work W is maintained as it is. First, the switching cylinder 76 of the bending blade switching mechanism 70 is operated in the contracting direction as shown in FIG. As a result, the preliminary bending blade 20B moves to the retracted position. This state is also shown in FIG. Further, the control device executes Step 5 (workpiece waiting) to confirm the original position state of the electric motor 41a. Next, step 6 (starting the main bending process) is executed, and the "motor rotation command" signal and the "speed command" signal are output from the control device, whereby the electric motor 41a is output.
Is activated and the nut 43 moves to the machining side again, thereby operating the toggle mechanism 31 in the extension direction. Then, as shown in FIG. 9 and FIG.
Tilts counterclockwise in the figure, whereby the main bending blade 20A descends toward the edge W2a of the work W.
At this stage, since the preliminary bending blade 20B is located at the retracted position, it does not contact the edge W2a of the work W.
After the main bending blade 20A comes into contact with the edge W2a, the pre-bent edge W2a is further bent by further descending. Also in this stage of the main bending, the toggle mechanism 31 operates in the extension direction, so that the receiving arm 21
Rotates in the clockwise direction in the drawing with the shaft 22 as a fulcrum, and its tip (pressurizing plate 23) is pressed against the lower surface of the lower die 2 by an upward force, whereby the lower die 2 receives the receiving arm 2
The main bending process is carried out by the state of being supported from below by 1.

At the lower end of the main bending blade 20A in the main bending process, the rotation speed of the electric motor 41a is appropriately controlled, and the pressing force of the main bending blade 20A is appropriately controlled by the load detection sensor 41b. Regulated.
That is, in the control device, step 7 (main bending is completed)
Is executed, the “motor rotation position confirmation command” signal and the “motor load confirmation command” signal are output, and the electric motor 41
The cumulative rotation speed and output torque of a are detected, and the pressing operation of the main bending blade 20A is continued until these values reach preset values. When it is confirmed that the cumulative number of rotations and the output torque of the electric motor 41a have reached the set values, step 8 (return to the standby position) is executed and the "motor rotation command" signal and the "speed command" signal are sent from the control device. This is output, whereby the electric motor 41a is reversely rotated at a predetermined rotation speed and the bending blade 20A is raised. Note that the moving end of the toggle mechanism 31 is also restricted by the extension of the toggle mechanism 31 and the contact of the convex portion 55 of the lower toggle link 34 with the side portion of the concave portion 54 of the upper toggle link 33. The lower end of the main bending blade 20A is restricted. The positions and the like of the convex portions 55 and the concave portions 54 are set so as to function when the main bending blade 20A further descends from the descending end of the main bending blade 20A set by the control device. Therefore, for example, when the electric motor 41a is activated and the main bending blade 20A is lowered in a state where the work W is not set on the lower die 2, damage to the parallel link mechanism 12, the toggle mechanism 31, etc. is prevented. . In this way, when the main bending blade 20A reaches the descending end and the main bending process is completed,
The electric motor 41c reversely rotates and the nut 43 moves leftward in FIG. 9, whereby the parallel link mechanism 12 tilts clockwise in the drawing and the main bending blade 20A rises. As described above, the processing unit 10 returns to the original position shown in FIG. When a series of hemming processing by the processing units 10 to 10 is completed as described above, the robot hand R
Operation, the work transfer jig 5 is moved upward, the pressed state of the work W is released, and the work W is taken out further. The work W taken out upward is transferred to the work transfer jig 5
The robot R is carried out by the operation of the robot R and is transported to a predetermined machined work storage location.

The bending apparatus H of this embodiment described above
According to this, the electric drive device 41 mainly including the electric motor 41a is used instead of the conventional hydraulic cylinder as the drive source for applying the pressing force to the work W to the main bending blade 20A and the preliminary bending blade 20B. Therefore, hydraulic piping is not required when using a hydraulic cylinder, which not only makes it possible to reduce the installation space of the bending apparatus H, but also eliminates troubles such as oil leaks, which greatly reduces the time and effort required for maintenance. Can be omitted. Further, since the electric motor 41a only needs to be driven at the stage of vertically moving the main bending blade 20A or the preliminary bending blade 20B, the hydraulic oil feeding device can be used even in the standby state (the stage of not vertically moving the bending blade) as in the conventional case. Power consumption can be greatly reduced compared to the hydraulic cylinder system that requires the operation of the (energy efficiency improvement). Furthermore, since the hydraulic oil feeder, which has conventionally been a noise source, is not used, the working environment can be improved.
Further, it is possible to solve the problem of environmental pollution caused by the disposal of used hydraulic oil when a hydraulic cylinder is used. Further, in the main bending process, the control device controls the rotation speed and output torque of the electric motor 41a,
Since the position and pressing force of the main bending blade 20A with respect to the edge W2a of the work W are appropriately controlled, the bending can be performed more reliably.

Further, a pre-bending blade 20B for pre-bending
Since the main bending blade 20A for the main bending and the main bending blade 20A for the main bending are separately prepared and dedicated for each processing, it is possible to prevent a decrease in the processing accuracy of the other when exchanging one or grinding for maintenance. it can. That is, as disclosed in Japanese Patent Laid-Open No. 2000-343156, in the case where the bending blade for pre-bending and the bending blade for main bending are integrally formed, although the parts used for bending are different, , If one of the bending blades is ground for maintenance, etc., the positional relationship between the cutting edge of one bending blade and the cutting edge of the other bending blade will change, and as a result, it will be This causes a problem that the bending accuracy is lowered. In this respect, according to the bending apparatus H of the illustrated embodiment, since the main bending blade 20A and the preliminary bending blade 20B are prepared separately, such a problem does not occur.

In the bending apparatus H according to this embodiment, the main bending blade 20A and the preliminary bending blade 20B are supported by the lower die 2 by the receiving arm 21 during the preliminary bending processing and the main bending processing. Since the hemming process is performed by pressing, the pressing force (upper pressing force) by the main bending blade 20A and the preliminary bending blade 20B can be offset by the pressing force (lower pressing force) from below by the arm 21. Therefore, even if the lower mold 2 is formed thin and is supported by about four supporting legs 2a to 2a, the lower mold 2 is prevented from being bent by the upper pressing force,
A predetermined processing accuracy can be secured. As a result, the lower die 2 can be made thinner and lighter, and the base 1 supporting the lower die 2 can be made smaller and lighter, which in turn makes it possible to reduce the weight of the bending apparatus H as a whole. It is possible to improve the handling of the apparatus H for transportation and installation work. Further, the downsizing of the lower die 2 leads to downsizing of the die required for producing the lower die 2, and as a result, die cost, material cost, etc. are reduced, and the production cost can be reduced. Also, toggle mechanism 3
By connecting the parallel link mechanism 12 to one end of 1 and the receiving arm 21 to the other end, the hemming operation by the main bending blade 20A and the preliminary bending blade 20B and the pressing operation from below the lower mold 2 are performed. Can be performed by one electric drive device 41 that drives the toggle mechanism 31. Therefore, the number of driving devices is small, and since the driving force can be amplified by the toggle mechanism 31, the electric driving device 41 can be made compact (small in diameter). Moreover, since the electric drive device 41 is arranged in the lower space of the lower die 2, the entire processing unit 10 can be moved closer to the lower die 2 side, and the entire bending device H can be made compact. You can

Various modifications can be made to the embodiment described above. For example, in the electric drive device 41,
Although a screw shaft device having a screw shaft 44 and a nut 43 meshing with the screw shaft 44 is illustrated as a mechanism for converting the rotational output of the electric motor 41a into a linear motion, instead of this, for example, a crank mechanism, a rack and pinion mechanism, and various other types. It is possible to utilize various motion conversion mechanisms. Also, a so-called linear motor that directly outputs a linear motion can be used as an electric drive device, and in this case as well, the same operational effects as described above can be obtained. Further, the switching cylinder 76 in the bending blade switching mechanism 70 may be replaced with an electric motor. Further, instead of the parallel link mechanism 12, a simple four-joint link mechanism (link mechanism that does not move the bending blade in parallel) may be used. The movement postures and movement loci of the bending blades 20A and 20B can be arbitrarily set by appropriately setting the interaxial distance of each link and the like in advance. Further, the configuration in which the output torque of the electric motor 41a is controlled to regulate the descending end of the main bending blade 20A is illustrated only in the main bending process, but the electric motor 4 is also used in the preliminary bending process.
In addition to the control of the position of the preliminary bending blade 20B based on the rotation speed of 1a, the pressing force of the preliminary bending blade 20B based on the output torque of the electric motor 41a is controlled, thereby controlling the descending end of the preliminary bending blade 20B. Good. further,
In the preliminary bending process and the main bending process, the electric motor 4
Control only the number of revolutions of 1a, or the electric motor 41a
It is also possible to control only the output torque of the above and regulate the descending ends of the main bending blade 20A and the preliminary bending blade 20B.

Further, the pressing operation of the receiving arm 21 from below the lower mold 2 may be omitted. Therefore, the receiving arm 21 and the toggle mechanism 31 can be omitted. On the other hand, as a drive source for pressing the receiving arm 21 to the lower mold, an actuator (cylinder, electric motor, etc.) different from the drive source (electric drive device 41) for pressing the bending blades 20A, 20B is used. It may be configured. Further, the preliminary bending process and the main bending process may be performed by individual dedicated processing units. Further, although the configuration in which the work W is carried in and out and carried to and from the lower mold 2 by using the robot hand R is illustrated, the robot hand R as the carrying device is not necessarily indispensable for carrying out the present invention. When the work W is carried in and out of the lower mold 2 and conveyed by hand, the load can be omitted. Further, the work W is not limited to the door panel of an automobile, but can be applied to other so-called engine hood panels, trunk lids and other automobile panel components, or panel components other than automobiles. Moreover, it is not limited to the hemming process, and only 1
It goes without saying that the same can be applied to the case where the edge portions of the steel plates are bent in a folded shape.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of the present invention, and is a front view of an entire bending apparatus.

FIG. 2 is a front view showing a preliminary bending process using a preliminary bending blade.

FIG. 3 is a front view showing a main bending process using a main bending blade.

FIG. 4 is a side view of the processing unit according to the embodiment of the present invention. This figure shows the standby state.

FIG. 5 is a side view of the processing unit during pre-bending.

FIG. 6 is a schematic diagram of a pre-bending operation.

FIG. 7 is a side view of a bending blade switching mechanism. This figure shows
It shows the standby state.

FIG. 8 is a side view of a bending blade switching mechanism. This figure shows
The state where the preliminary bending blade has moved to the processing position is shown.

FIG. 9 is a side view of the processing unit during the main bending process.

FIG. 10 is a schematic diagram of a main bending operation.

FIG. 11 is a diagram showing a control flow of the electric motor.

[Explanation of symbols]

H ... Bending machine 2 ... Lower mold 5 ... Work transfer jig 10 ... Processing unit 11 ... Unit bracket 12 ... Parallel link mechanism 20A ... main bending blade, 20B ... preliminary bending blade 21 ... Receiving arm 31 ... Toggle mechanism 41 ... Electric drive device, 41a ... Electric motor 44 ... Screw shaft 70 ... Bending blade switching mechanism W ... Work, W2a ... Edge R ... Robot hand

Claims (7)

[Claims] 1. A bending apparatus for pressing a bending blade against an edge of a work to bend the edge, wherein the bending blade is moved by using an electric drive device having an electric motor as a drive source. Bending device configured to press against the edge of. 2. The bending apparatus according to claim 1, wherein
A control device for controlling the rotation speed and the output torque of the electric motor is provided, and the position of the bending blade is controlled on the basis of the rotation speed, and the pressing force of the bending blade on the edge portion of the workpiece based on the output torque. Bending device configured to control. 3. The bending apparatus according to claim 1, wherein the bending blade is provided so as to be movable back and forth with respect to the edge of the work through a parallel link mechanism, and the parallel link mechanism is driven by an electric drive device. A bending apparatus configured to be operated to press the bending blade against the edge of the work. 4. The bending apparatus according to any one of claims 1 to 3, further comprising a lower die for mounting an edge of a work, when a bending blade is pressed against the edge of the work. A bending apparatus having a pressing force receiving device for receiving a pressing force applied to the lower die in a bending direction. 5. The bending apparatus according to claim 4, wherein:
The pressing force receiving device is a bending device including a receiving arm that is pressed in the anti-bending direction with respect to the lower die in conjunction with the movement of the bending blade in the bending direction. 6. The bending apparatus according to claim 1, wherein the bending blade includes a pre-bending blade that pre-bends the edge of the work, and a main bending blade that main-bends at an angle larger than the pre-bending. The preliminary bending blade and the main bending blade are provided so as to be movable relative to each other, and the preliminary bending blade and / or the main bending blade are relatively moved in accordance with the preliminary bending step or the main bending step, and the preliminary bending blade is provided. Alternatively, a bending apparatus configured to select and use the main bending blade. 7. The bending apparatus according to claim 6, wherein:
A control device for controlling the rotation speed and the output torque of the electric motor is provided, and in the preliminary bending step, the position of the preliminary bending blade with respect to the edge portion of the work is controlled based on the rotation speed. A bending apparatus configured to control the position of the main bending blade based on the output torque and the position and pressing force of the main bending blade with respect to the edge portion of the work based on the output torque.