JP2003340538A - Work transfer apparatus and control method for pressing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-size and inexpensive work transfer apparatus and a control method therefor which can reliably prevent interference of a mold with a feed bar 1 upon electric power failure. <P>SOLUTION: In this work transfer apparatus for a pressing machine, a feed bar 1 is driven using servo motors 12C, 12L, 12F as a drive source to transfer a work to a plurality of working stations successively. Power failure backup devices 14C, 14L for supplying electric power upon electric power failure are provided only in the servo motors 12C, 12L for driving a clamp shaft and/or a lift shaft. <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 work transfer device of a press machine for sequentially transferring a work to a plurality of processing stations by driving a pair of feed bars arranged in the transfer direction by a servo motor.

[0002]

2. Description of the Related Art Conventionally, a work transfer device (transfer feeder) for automatically loading and unloading a work to and from a plurality of processing stations in synchronization with a crankshaft rotation angle of a press machine (transfer press) having a plurality of processing stations. Simultaneously controls a pair of feed bars movable in two-dimensional or three-dimensional directions to grip and convey a work. This synchronous control with respect to the crankshaft rotation angle is performed by the shafts of the pair of feed bars (for example, 3
In the case of dimensional motion, the electric synchronous type is widely used to control the servo motor provided corresponding to each axis so that the motion of the feed axis, lift axis, clamp axis) moves according to the preset motion curve. Has been done.

In such a system, when a power failure occurs, the feed bar of the work transfer device immediately stops by regeneratively braking the servo motor, but the press slide of the press machine has a large inertial force. It will stop slipping. For this reason, the crankshaft rotation angle and the motion of the feed bar are out of synchronization, and the mold and the feed bar interfere with each other, which may damage the mold or damage the feed bar. A system as shown in FIG. 7 is adopted in order to prevent the synchronization deviation when the power failure occurs.

That is, the controller 50 controls the crankshaft rotation angle signal θ from the crankshaft rotation angle detector 15.
By inputting a control command for each of the lift, clamp and feed axes based on the motion curve data stored in the controller 50, the servo amplifier 11L for controlling the lift axis, and the servo amplifier 1 for controlling the clamp axis.
1C and the servo amplifier 11F for controlling the feed axis, respectively. Each servo amplifier 11L, 11C, 11
F converts the electric power supplied from the power supply power source 13 such as AC400V into a drive electric power signal according to the control command, and supplies it to the lift servo motor 12L, the clamp servo motor 12C, and the feed servo motor 12F, respectively. Output.

Corresponding to each servo amplifier 11L, 11C, 11F, power failure backup device 54L, 54C, 54
F is provided. Each blackout backup device 54L,
54C and 54F are provided with capacitors as means for storing the electric power supplied from the power supply source 13, and the stored electric power is supplied to the corresponding servo amplifiers 11L, 11C,
It is connected so that it can be supplied to 11F. When the power failure detector 16 detects a power failure, the controller 50 switches the power failure backup devices 54L, 54C, 54F to store the stored power in the servo amplifiers 11L, 11C, 1
In addition to being supplied to 1F, a control command for synchronizing the feed bar with the crankshaft rotation angle θ of the press machine that stops sliding is output to each servo amplifier 11L, 11C, 11F and supplied from each power failure backup device 54L, 54C, 54F. Power of each servo motor 12L, 12C, 12
Stop while driving F.

According to the above construction, even when a power failure occurs, the feed bar of the work transfer device uses the power supplied from the power failure backup devices 54L, 54C and 54F for the lift, clamp and feed axes. The respective servo motors 12L, 12C, 12F are stopped while being driven in synchronization with the crankshaft rotation angle θ of the press machine.
Therefore, it is possible to prevent interference between the die and the feed bar when the press machine and the work transfer device stop due to a power failure. In addition, power failure backup devices 54L and 54 are provided for each axis.
Instead of providing C and 54F, one power failure backup device having a capacity equal to the total capacity of these is provided,
Even if the power is supplied to each of the servo amplifiers 11L, 11C, and 11F, the same effect can be obtained.

[0007]

However, the above-mentioned prior art has the following problems. That is, since it is a system that backs up all the lift, clamp, and feed axes, power outage backup devices 54L, 54C, and 54F are required to have a large capacity, resulting in a large installation space and high cost.

The present invention has been made in view of the above problems, and provides a small and inexpensive work transfer device capable of reliably preventing interference between a die and a feed bar at the time of power failure, and a control method thereof. Is intended.

[0009]

In order to achieve the above object, the first invention is to drive a feed bar using a servo motor as a drive source to sequentially convey a work to a plurality of processing stations. A work transfer device of a press machine is characterized by including a power failure backup device that supplies power to a servomotor that drives a clamp shaft and / or a lift shaft when a power failure occurs. A second invention, which is a control method of the first invention, is a method for controlling a work transfer device of a press machine, which drives a feed bar using a servo motor as a drive source to sequentially transfer a work to a plurality of processing stations. At the time of a power failure, only the servomotor that drives the clamp axis and / or the lift axis is driven by the power supplied from the power failure backup device.

According to the above construction, even if a power failure occurs, the servomotor for the clamp shaft and / or the lift shaft is driven by the power supplied from the power failure backup device, and the feed bar is used as a mold. Can be retracted to a position where it does not interfere. Therefore, it is possible to prevent interference between the die and the feed bar when the press machine and the work transfer device stop due to a power failure. Also, of the lift, clamp, and feed axes, there is no need for a backup for the feed axis, which has a large stroke and requires a large capacity. Therefore, the capacity of the power failure backup device can be small, and it is compact and space-saving. An inexpensive work transfer device can be obtained.

In the present invention, it is preferable to drive only the unclamping motion of the clamp shaft and / or the down motion of the lift shaft during a power failure. By doing so, the power from the power failure backup device is supplied only to the drive to the position where the feed bar and the mold do not interfere with each other, that is, the drive in the direction necessary to prevent the interference. It is possible to prevent unnecessary movement of the feed bar against a power failure when there is no fear of

Further, in the present invention, it is preferable that the crankshaft rotation angle of the press machine is detected and the servomotor is driven when the crankshaft rotation angle is within a predetermined range during a power failure. By doing so, power is supplied from the power failure backup device to drive the feed bar only at the crankshaft rotation position where the feed bar and the mold may interfere, so there is a risk of interference between the feed bar and the mold. It is possible to prevent unnecessary movement of the feed bar at a crankshaft rotation position where there is no.

Further, in the present invention, it is preferable that the crankshaft rotation angle of the press machine is detected and the servomotor is driven in synchronization with the crankshaft rotation angle when a power failure occurs. As a result, the same control as the synchronous control with the crankshaft rotation angle during normal operation is performed at the time of power failure, so that the control becomes easy.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Embodiments will be described below with reference to the drawings. FIG. 1 shows a feed bar 1 of a work transfer device.
FIG. The feed bar 1 is composed of a pair of bars 1a and 1b facing each other, and fingers 2a, 2b and 2c for clamping a work carried in and out of the press machine are provided on inner surfaces of the bars 1a and 1b which face each other. It is installed. The bars 1a and 1b can be moved in the directions of three axes orthogonal to each other by a servo motor, which will be described later. The three axes are the feed axes which are the directions in which the bars 1a and 1b are directed and which are the conveyance direction of the work, The clamp shaft is a direction in which the bars 1a and 1b are opened and closed, and the vertical lift shaft.

In FIG. 1, the moving directions of the feed shaft, the clamp shaft and the lift shaft are indicated by F, C and L, respectively. Here, an example in which the feed bar 1 moves three-dimensionally (three-dimensional motion) is shown, and advance movement F1 → down movement L1 → unclamp movement C1 → return movement F2 → clamp movement C2 → lift movement L2. → It is designed to move sequentially like the advance movement F1. This movement pattern is based on a motion curve that will be described later and is set in advance.

The feed bar 1 is arranged, for example, in front of and behind a mold installed in a press machine (not shown) (on the front and rear of the press machine), and is driven in conjunction with the operation of the press machine. It That is, the relationship between the crankshaft rotation angle θ of the press machine and the position of the feed bar 1 in each axial direction is set in advance as a motion curve as shown in FIG. 2 (the dotted line is the lift axis motion curve,
The one-dot chain line is the clamp axis motion curve, the two-dot chain line is the feed axis motion curve, and the solid line is the press slide motion curve. Based on this motion curve, the feed bar 1 is synchronized with the crankshaft rotation angle θ in each axis direction. Positioning is controlled.

As shown in FIG. 3, the controller 10 is connected to a servo amplifier 11L for controlling the lift axis, a servo amplifier 11C for controlling the clamp axis, and a servo amplifier 11F for controlling the feed axis, and each servo amplifier is connected. A lift servomotor 12L, a clamp servomotor 12C, and a feed servomotor 12F are connected to 11L, 11C, and 11F, respectively. In addition, a power supply power supply 13 such as AC 400V for supplying drive power to each servo motor 12L, 12C, 12F is connected to each servo amplifier 11L, 11C, 11F.

The lift shaft servo amplifier 11L and the clamp shaft servo amplifier 11C are provided with power failure backup devices 14L and 14C, respectively. Each power failure backup device 14L, 14C is a power supply 13
A capacitor is provided as a means for storing the electric power supplied from the controller 10, and the stored electric power can be supplied to the servo amplifiers 11L and 11C for the lift shaft and the clamp shaft by the switching signal output from the controller 10. , And are connected to the servo amplifiers 11L and 11C, respectively. A crankshaft rotation angle detector 15 that detects a crankshaft rotation angle θ of the press machine and a power failure detector 16 that detects a power failure are connected to the controller 10. The controller 10 is connected to an uninterruptible power supply (not shown) that supplies control power even when a power failure occurs.

During normal operation, the controller 10 receives the crankshaft rotation angle signal θ from the crankshaft rotation angle detector 15 and lifts the lift based on the motion curve data stored in the controller 10 as shown in FIG. , Control commands for each axis of clamp and feed,
It outputs to each servo amplifier 11L, 11C, 11F. Each of the servo amplifiers 11L, 11C, 11F converts the electric power supplied from the power supply power source 13 into a drive power signal according to the control command, and each servo motor 12L, 12C, 1F.
By outputting each to 2F, the work transfer device can be driven in synchronization with the crankshaft rotation angle θ of the press machine.

Next, the control when a power failure occurs will be described with reference to FIG.
Will be explained. The controller 10 performs step S1
At, the power failure signal from the power failure detector 16 is confirmed, and if there is no power failure, the control returns to the normal synchronous control of the work transfer device for the crankshaft rotation angle θ. When the power failure signal is input in step S1, the controller 10 operates in step S2.
Proceed to. The power failure signal is also input to the control device of the press machine, the press machine is switched to the emergency stop mode, and the press slide is stopped by regenerative braking or mechanical brake (non-excitation type). At this time, since the press slide has an extremely large inertial force, it does not stop immediately but stops while sliding.

In step S2, the controller 10 determines whether or not the crankshaft rotation angle θ is within a predetermined range (θ1 to θ2), and if it is within the predetermined range, step S3.
I will proceed. Here, when the press machine and the work transfer device are out of synchronization with each other, the interference between the die and the feed bar 1 occurs in the region where the press slide descends from the top dead center to the bottom dead center. The predetermined range (θ1 to θ2) requires control for interference prevention in consideration of the shapes of the fingers 2a, 2b, 2c of the feed bar 1 and the die and the coasting distance until the press slide stops. As the crankshaft rotation position, for example, crankshaft rotation angles θ1 to θ shown in FIG.
The range of 2 is set. The predetermined range θ1 to θ
2 is shown in the movement pattern diagram of the feed bar 1 as shown in FIG.
As shown in (1), it corresponds to the middle (θ1) of the advance movement F1 to the initial (θ2) of the return movement F2.

In step S3, the controller 10 outputs a switching signal to each of the power failure backup devices 14L and 14C and sends a control command to the lift shaft and the clamp shaft based on the motion curve data corresponding to the crankshaft rotation angle θ. It outputs to each of the amplifiers 11L and 11C. Also, a regenerative braking command is output to the servo amplifier 11F for the feed axis. As a result, the feed shaft immediately stops and the lift shaft and the clamp shaft cause the servomotors 12L and 12C to rotate the crankshaft rotation angle θ by the power supplied from the power failure backup devices 14L and 14C.
It is driven in synchronization with. Then, the control of step S3 is continued until the press slide is stopped in step S4. If the crankshaft rotation angle θ is out of the predetermined range in step S2, the lift shaft,
Servo amplifiers 11L for clamp axis and feed axis,
Regenerative braking command is output to 11C and 11F. As a result, the feed bar 1 immediately stops regardless of the press slide that stops sliding.

With the above control, as shown in FIG. 5, when a power failure occurs when the crankshaft rotation angle θ is at the position P1 of the advance motion F1 within the predetermined range θ1 to θ2, the controller 10 switches the feed shaft to While stopping by regenerative braking, the lift shaft and the clamp shaft are synchronized with the crankshaft rotation angle θ by the electric power stored in the power failure backup devices 14L and 14C, and the arrow Lp (down movement) in FIG.
It is driven along Cp (unclamping movement) and stopped when the slide of the press slide stops. On the other hand, the crankshaft rotation angle θ is outside the predetermined range θ1 to θ2 at positions P2 and P3.
If a power outage occurs while being in the same position, the controller 10 immediately stops all the lift, clamp, and feed axes at that position by regenerative braking.

According to the above configuration, when a power failure occurs,
Since the lift shaft and the clamp shaft are driven in synchronization with the crankshaft rotation angle θ by the electric power stored in the power outage backup devices 14L and 14C, the interference between the feed bar 1 and the mold can be prevented. In addition, the power failure backup device 14 is installed only on the lift shaft and clamp shaft required to avoid interference.
Since the feed shaft that is equipped with L and 14C and has a large stroke and requires a large capacity does not need a power failure backup device, the capacity of the power failure backup device as a whole can be small, so that the device is small and inexpensive. In addition, since the power is supplied from the power failure backup devices 14L and 14C to drive the lift shaft and the clamp shaft only at the crankshaft rotation position where the feed bar 1 and the mold may interfere with each other,
It is possible to prevent unnecessary movement of the feed bar 1 at a position where there is no risk of interference. In addition, the crankshaft rotation angle θ during a power failure
Since the drive control of the lift shaft and the clamp shaft in synchronism with the above is the same as the synchronous control during the normal operation, the control becomes easy.

It is needless to say that the present invention is not limited to the above embodiment, and changes and modifications can be made within the scope of the present invention. For example, the power failure signal from the power failure detector 16 may be directly input to the power failure backup devices 14L and 14C without passing through the controller 10. Thereby, there is no calculation delay by the controller 10, and the power failure backup device 1 at the time of power failure
It is possible to quickly switch to 4L and 14C.
Further, although the conveyance by the three-dimensional motion by the clamp, the lift and the feed has been described as an example, the present invention may be applied to the horizontal two-dimensional motion by the clamp and the feed. Also in this case, the system for backing up only the clamp shafts necessary for avoiding interference during a power failure makes the power failure backup device small and inexpensive.

At the position of the return movement F2 where the feed bar 1 is farthest from the die (see FIG. 5), the feed bar 1 does not interfere with the die regardless of the feed stroke position. The position of can be considered as the retracted position of the feed bar 1 at the time of power failure. Therefore, as in the above-described embodiment, the lift shaft and the clamp shaft are not driven in synchronization with the crankshaft rotation angle θ when a power failure occurs, but the crankshaft rotation angle θ is changed to the crankshaft rotation angle θ as shown by a dotted arrow A in FIG. The lift shaft and the clamp shaft may be simultaneously driven toward the retracted position (F2) from the position P1 without being synchronized. Furthermore, regardless of the crankshaft rotation position, when power failure occurs, position P in FIG.
From 2, P3, etc., the lift shaft and the clamp shaft are simultaneously retracted without synchronizing with the crankshaft rotation angle θ (F2).
You may control so that it may go to.

Further, the power failure backup devices 14L, 14
Although C has been described as an example in which it is provided for each of the servo amplifiers 11L and 11C, as shown in FIG.
In place of 4L and 14C, a single power failure backup device 24 having a storage capacity equivalent to the total capacity of these is provided, and power is supplied to the lift axis servo amplifier 11L and the clamp axis servo amplifier 11C. Also has the same effect. Of course, also in this case, the power failure signal from the power failure detector 16 may be directly input to the power failure backup device 24 without passing through the controller 20.

As described above, according to the present invention, only the drive shaft necessary for avoiding interference is backed up at the time of power failure (that is, the feed shaft is not backed up).
By using the system, it is possible to reliably prevent interference between the die and the feed bar at the time of power failure, the capacity of the power failure backup device is small, and a small and inexpensive work transfer device can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a feed bar according to an embodiment.

FIG. 2 is a diagram showing a motion curve of a feed bar according to the embodiment.

FIG. 3 is a control block diagram of the work transfer device according to the embodiment.

FIG. 4 is a diagram showing a processing procedure at the time of a power failure according to the embodiment.

FIG. 5 is a movement pattern diagram illustrating an operation according to the embodiment.

FIG. 6 is a control block diagram of another aspect.

FIG. 7 is a control block diagram of a conventional technique.

[Explanation of symbols]

1 ... Feed bar, 10, 20 ... Controller, 11
L, 11C, 11F ... Servo amplifier, 12L, 12C,
12F ... Servo motor, 13 ... Power supply power source, 14L,
14C, 24 ... Blackout backup device, 15 ... Crankshaft rotation angle detector, 16 ... Blackout detector, θ ... Crankshaft rotation angle.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B30B 15/00 B30B 15/00 B

Claims (5)

[Claims] 1. A work transfer device of a press machine, which drives a feed bar (1) by using a servo motor (12C, 12L, 12F) as a drive source to sequentially transfer a work to a plurality of processing stations. Servo motor that drives the lift shaft
A work transfer device for a press machine, which is equipped with a blackout backup device (14C, 14L) that supplies electric power only in the case of (12C, 12L). 2. A method of controlling a work transfer device of a press machine, which drives a feed bar (1) using a servo motor (12C, 12L, 12F) as a drive source to sequentially transfer a work to a plurality of processing stations. A method for controlling a work transfer device, comprising: driving only a servomotor (12C, 12L) that drives a clamp shaft and / or a lift shaft by electric power supplied from a power failure backup device (14C, 14L). 3. The method for controlling a work transfer apparatus according to claim 2, wherein only the unclamping movement (C1) of the clamp shaft and / or the down movement (L1) of the lift shaft is driven during a power failure. Control method for work transfer device. 4. A crankshaft rotation angle (θ) of a press machine is detected, and the crankshaft rotation angle (θ) is within a predetermined range (θ1 to
4. The method of controlling a work transfer device according to claim 2, wherein the servo motor (12C, 12L) is driven in the case of θ2). 5. A crankshaft rotation angle (θ) of a press machine is detected, and the servomotors (12C, 12L) are driven in synchronization with the crankshaft rotation angle (θ) at the time of power failure. The method for controlling the work transfer device according to claim 2, 3, or 4.