TWI411526B - Stamping machine and control method thereof - Google Patents

Abstract

A press machine includes a selection mechanism (13) that is installed on a power transmission line from a servo-motor (7) to a slide (5) and selectively changed between a power transmission state in which the power from the servo-motor (7) is transmitted to the slide (5) and a non-power transmission state in which the power from the servo-motor (7) is not transmitted to the slide (5). The press machine further includes a slide holding mechanism (15) selectively changed between a slide non-holding state in which the lifting motion of the slide (5) is not restricted and a slide holding state in which the lifting motion of the slide (5) is restricted. A control device (11) changes the slide holding mechanism (15) to the slide holding state after stopping the slide (5) by controlling the angle of the rotation of the servo-motor (7), and then changes the selection mechanism (13) to the power non-transmission state.

Description

Stamping machine and control method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a press machine, and more particularly to a press machine that uses a servo control to raise and lower a slider to stop.

The press machine has an upper mold and a lower mold, and is clamped by clamping the workpiece in the up and down direction; the slider is fixed with an upper mold to move up and down; the drive motor is used to make the slider The lifting mechanism and the changing mechanism convert the rotational motion of the driving motor into a lifting motion and transmit it to the slider.

In the operation of the press machine, the workpiece (sheet, etc.) that has been press-formed is taken out from between the upper mold and the lower mold, and the sheet before the press working is carried between the upper mold and the lower mold. Therefore, each time a piece of the plate is formed, the slider is repeatedly lifted and stopped, and the slider is lowered again after the loading of the plate is completed. The lowering, rising, and stopping of the slider are performed every cycle, so switching from stop to fall and from up to stop can be performed in a short time.

Therefore, servo control can be used for control. In the press machine using the servo control, since the slider acceleration/deceleration can be stopped by the servo control of the servo motor rotation angle, the switching of the slider movement from the stop to the stop and from the stop to the fall can be performed in a short time. A press machine using the servo control described above is described, for example, in Patent Document 1 below.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-271070

In general, the stamping machine will be equipped to resist gravity and support slippage. Block balancer (Counter Balance). In this case, the slider has two forces: the force pulled downward by its own weight, and the force lifted up by the balancing device, but the two usually do not balance. Therefore, in a press machine using servo control, in order to keep the slider in the stop position, it is necessary to generate a torque in the servo motor. Therefore, a current flows in the servo motor to generate heat, thereby causing waste of energy.

Further, while the slider is stopped, the servo motor is controlled such that the rotation angle of the servo motor coincides with the constant rotation angle corresponding to the stop position of the slider, but the servo motor will be slightly different due to a certain difference between the rotation angle and the detection angle value. Repeat the tiny positive and negative movements. Therefore, in the power transmission path from the servo motor to the slider, the power transmission mechanism may be deteriorated due to repeated contact between the gears.

The waste of energy and the deterioration of the power transmission mechanism are particularly noticeable when the slider stops for a long time. For example, when the plate is moved between the dies by a manual or low-speed conveying device, the slider stop time becomes longer, and the waste of energy and the deterioration of the power transmission mechanism are more conspicuous.

Accordingly, it is an object of the present invention to provide a press machine which can reduce power consumption when a punching machine using a servo motor is in a stopped state, and can prevent repeated repetition of gears due to a slight forward and reverse movement of the servo motor. Contact with the tooth surface causes deterioration of the power transmission mechanism.

In order to achieve the above object, the present invention provides a press machine having an upper mold and a lower mold for clamping a workpiece in a vertical direction for punching, and a slider for fixing a lower mold to perform a lifting movement; a motor for moving the slider up and down; and a changing mechanism for converting a rotary motion of the servo motor into a lifting motion and transmitting the same to the slider; the pressing device having: a control device for imparting a desired The command rotation angle value of the slider movement mode of the slider movement is compared with the detection value of the rotation angle of the servo motor, and the rotation angle of the servo motor is controlled in accordance with the command rotation angle value; the switching mechanism is set to the slave servo The horse reaches the power transmission path of the slider, and selectively switches: a power transmission state in which the power from the servo motor is transmitted to the slider, and a power non-transmission state in which the power from the servo motor is not transmitted to the slider; and the slider The holding mechanism is selectively switched: a non-holding state in which the lifting movement of the slider is unrestricted, and a slider holding state in which the lifting movement of the slider is restricted; and the control device is provided by a servo motor After the rotation angle is controlled to stop the slider, the slider holding mechanism is switched to the slider holding state, and then the switching mechanism is caused In other non-powered convey status.

Further, in order to achieve the above object, the present invention provides a control method for a press machine having an upper mold and a lower mold, which are clamped in a vertical direction to press the workpiece, and the slider is fixed on the lower surface. a lifting motion of the mold; a servo motor for lifting the slider; and a changing mechanism for converting the rotational motion of the servo motor into a lifting motion and transmitting to the slider; the control method having the following features: The switching mechanism for switching between the two states is provided in a power transmission path from the servo motor to the slider: a power transmission state in which power from the servo motor is transmitted to the slider, and power that does not transmit power from the servo motor to the slider Non-communicating state; setting a slider holding mechanism that selectively switches the following two states: a non-retaining state in which the lifting movement of the slider is unrestricted, and a slider holding state in which the lifting movement of the slider is restricted; a rotation angle value according to an instruction to impart a desired slider movement mode, Comparing with the detected value of the rotation angle of the servo motor, the rotation angle of the servo motor is controlled in accordance with the command rotation angle value, whereby the slider is lowered and pressed, and then the slider is raised and stopped at the target stop position; After the slider stops at the target stop position, the slider holding mechanism is switched to the slider holding state; and after the slider holding mechanism is switched to the slider holding state, the switching mechanism is switched to power non-communication status.

In the above-described press machine and control method therefor, after the slider is stopped by the rotation angle control of the servo motor, the slider holding mechanism is switched to the slider holding state, and then the switching mechanism is powered Non-communicating status. Therefore, in the stopped state of the slider, since the slider is held by the slider holding mechanism, there is no need to supply current to the servo motor to keep the slider in the stop position, and since the servo motor and the slider are separated into power Since the state is transmitted, the torque required for the forward and reverse rotation of the servo motor is reduced, and as a result, the current supplied to the servo motor can be made small. Therefore, the power consumption in the stop of the slider can be lowered.

Further, in the stop of the slider, since the slight repeated forward/reverse motion of the servo motor is not transmitted to the power transmission path from the position where the power transmission from the servo motor 7 is separated to the slider by the switching mechanism, There is no slight repetitive motion in this power transmission path. Therefore, it is possible to prevent the power transmission path from being deteriorated due to repeated contact with the tooth surface or the like between the gears.

Therefore, in the stop of the slider, the power consumption can be reduced and the deterioration of the power transmission mechanism caused by the meshing portion between the gears repeatedly contacting the tooth surface due to the forward and reverse movement of the servo motor can be prevented.

In addition, the above-described press machine and its control method also have the following advantages: (1) The slider holding mechanism can be utilized even when the slider is stopped, even if the power is not transmitted from the servo motor to the slider. Keep the slider in the stop position.

(2) Since the slider holding mechanism is actuated to the stopped slider, friction and heat due to the braking action do not occur between the slider holding mechanism and the power transmission mechanism at the start of the operation. Further, during the slider holding period, since the slight forward/reverse movement of the servo motor is not transmitted to the slider, friction and heat generation do not occur between the slider holding mechanism and the power transmission mechanism during this period.

(3) Similarly to the press machine using the conventional servo control, since the slider movement is controlled by the servo control, the movement of the slider from the rise to the stop and from the stop to the fall can be performed in a short time.

(4) The energy can be regenerated by changing the supply power to the servo motor in the deceleration of the slider, and the energy use efficiency is improved.

According to the above, the present invention can reduce the power consumption by using a servo-controlled press machine, and can prevent the power transmission mechanism from being repeatedly contacted between the gears due to the slight forward and reverse movement of the servo motor. deterioration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a structural view of a press machine according to an embodiment of the present invention. As shown in Fig. 1, the press machine 10 includes an upper mold 3a and a lower mold 3b, and presses the workpiece 1 in the vertical direction, and the slider 5 has the upper mold 3a fixed thereto. The lifting motion; the servo motor 7 is for raising and lowering the slider 5; and the changing mechanism 9 converts the rotational motion of the servo motor into a lifting motion and transmits it to the slider 5.

The press machine 10 is provided with a control device 11, a switching mechanism 13, and a slider holding mechanism 15.

The control device 11 compares the command rotation angle value with the detection value of the rotation angle of the servo motor 7 in accordance with the preset slider operation mode, and controls the rotation angle of the servo motor 7 so as to follow the command rotation angle value.

The switching mechanism 13 is provided in a power transmission path from the servo motor 7 to the slider 5, and has a structure for selectively switching between two states in which the power from the servo motor 7 is transmitted to the slider 5 and the power transmission state is not caused. The power from the servo motor 7 is transmitted to the power non-conveying state of the slider 5. The switching mechanism 13 is switched to the power non-conveying state by the control device 11 after the slider 5 is stopped by the control of the rotation angle of the servo motor 7.

As a mechanism for operating the switching mechanism 13 to a position corresponding to the power transmission state and a position corresponding to the power non-transmission state, a mechanism for directly operating the switching mechanism 13 by a solenoid driven by electromagnetic force, or A mechanism for controlling the oil pressure or the air pressure by an electromagnetic coil driven by an electromagnetic force and operating the switching mechanism 13 by a hydraulic cylinder or a pneumatic cylinder.

In the example of Fig. 1, the switching mechanism 13 is a clutch. The clutch can use a dry or wet structure that transmits power by the friction between the friction plates. Build, or use the meshing of the mechanism to convey the structure of the power.

The slider holding mechanism 15 has a structure that is selectively switched to a non-holding state in which the lifting movement of the slider 5 is not restricted, and a slider holding state in which the lifting movement of the slider 5 is restricted. The slider holding mechanism 15 is driven to the slider holding state by the control device 11 after the slider movement is stopped and the switching mechanism 13 is switched to the power non-conveying state.

As a mechanism for operating the slider holding mechanism 15 to the non-holding state and the slider holding state, a mechanism for directly moving the slider holding mechanism 15 by an electromagnetic coil driven by an electromagnetic force or an electromagnetic body driven by an electromagnetic force can be used. The coil controls the oil pressure or the air pressure, and the mechanism that moves the slider holding mechanism 15 by the hydraulic cylinder or the pneumatic cylinder.

In the example of Fig. 1, the slider holding mechanism 15 is a mechanical brake. As the mechanical brake, a disc brake that presses the friction pad to the brake disc, or a brake that tightens the drum with the brake band can be used.

Next, the configuration of the control device 11 will be described in detail. The control device 11 includes a press machine controller 11a, a servo controller 11b, and a motor drive amplifier 11c.

The press machine controller 11a outputs a command rotation angle value in accordance with a preset slider operation mode. The slider operation mode sets the command rotation angle value (corresponding to the slider position) corresponding to the time, and the press machine controller 11a outputs the command rotation angle value of the servo motor 7 corresponding to the time point according to the slider operation mode at each time point. . In the press controller, the detected rotation angle value is input from the motor rotation angle encoder 17 that detects the rotation angle of the servo motor 7.

The press machine controller 11a outputs a clutch connection command to the clutch 13, so that the output shaft of the servo motor 7 is connected to the input shaft of the speed reducer 21 to be described later, the clutch 13 is in the power transmission state, and the clutch release command is output to the clutch 13. The clutch 13 is brought into a power non-conveying state by separating the output shaft of the servo motor 7 from the input shaft of the speed reducer 21.

Further, the press machine controller 11a also outputs a brake actuation command to the brake 15 to actuate the brake 15 to a position where the slider 5 is held at the stop position, and outputs a brake non-actuation command to the brake 15 to actuate the brake 15 to prevent the slider 5 from being obstructed. The location of the movement.

Further, the press machine controller 11a may be configured using a relay circuit, a digital logic circuit, or a programmable logic controller (PLC).

The servo controller 11b compares the detected rotation angle of the servo motor 7 from the motor rotation angle encoder 17 with the command rotation angle value from the press machine controller 11a, and outputs the rotation angle of the servo motor 7 in accordance with the command rotation angle value. The instruction value.

The control method of the servo controller 11b can be configured by combining feedback control in which feedforward control is combined to PI (proportional-integral), PID (proportional-integral-derivative), IPD (integral-proportional-differential), and the like as needed.

The motor drive amplifier 11c is electrically connected to the servo motor 7, and changes the current and voltage supplied to the servo motor 7, whereby the torque and the number of revolutions of the servo motor 7 can be changed. The motor drive amplifier 11c receives a command value from the servo controller 11b, and supplies a current and a voltage according to the command value to the servo motor 7, whereby the slider 5 is moved in accordance with the slider operation mode.

Regarding the motor drive amplifier 11c, a pulse width modulation (PWM) using a power metal oxide semiconductor field effect transistor (POWER MOSFET) or an insulated gate bipolar transistor (IGBT) can be used when the AC servo motor is used. In the case of a converter, a chopper method using a thyristor Thyristor Leonard system or an insulated gate bipolar transistor can be used when a DC servo motor is used. Further, the motor drive amplifier 11c is configured to regenerate energy like a four-quadrant control inverter, whereby the kinetic energy is converted into electric energy and recovered when the servo motor 7 is decelerated, and energy loss can be reduced.

Further, the servo motor 7 can use an induction motor, a synchronous motor, a direct current motor, or the like.

The motor rotation angle encoder 17 can use an optical encoder or a resolver.

Further, in the example of Fig. 1, a crankshaft rotation angle encoder 19 for detecting the rotation angle of the crankshaft 9a to be described later is provided, and the rotation angle of the detected crankshaft from the crankshaft rotation angle encoder 19 is input to the press machine control. 11a. Since the size and shape of the crankshaft 9a and the connecting rod 9b are known, the crankshaft rotation angle and the slider height can be mutually converted by calculation. Therefore, the crankshaft rotation angle input to the press machine controller 11a can be used for the operation confirmation. The crankshaft rotation angle encoder 19 can use an optical encoder or a resolver.

Next, the configuration of the other portions of the press machine 10 will be described.

The rotation of the servo motor 7 is transmitted to the reducer via the clutch 13 twenty one. The rotation is decelerated by the speed reducer 21, and the crankshaft 9a is rotated by the output of the speed reducer 21. The crankshaft 9a and the slider 5 are mechanically coupled by the connecting rod 9b, and the crankshaft 9a rotates, and the slider 5 moves up and down. Further, the speed reducer 21 can use, for example, a mechanism that meshes a spur gear or a bevel gear having a different number of teeth.

The lower mold 3b is attached to a bolster 23. At the time of press working, the load acting on the upper mold 3a is supported by the upper portion of the frame 25 via the slider 5, the connecting rod 9b, and the crank shaft 9a, and the load acting on the lower mold 3b is supported by the lower portion of the frame 25 via the carrier plate 23. . The workpiece 1 to be subjected to press forming is inserted between the upper mold 3a and the lower mold 3b, and the slider 5 is lowered, and the workpiece 1 comes into contact with the upper mold 3a and the lower mold 3b, from the upper mold 3a and the lower mold 3a. The mold 3b applies a press forming force to the workpiece 1 .

Further, a balancing device 27 is provided in order to support the weight of the slider 5 and the upper mold 3a. As shown in Fig. 1, the mechanism of the balancer 27 can be an air balance device or the like that pushes up the piston 27a by compressed air in the cylinder.

The control method of the press machine 10 having the above configuration will be described below. Fig. 2 is a flow chart showing a control method of the press machine 10.

In step S1, the slider 5 is in a stopped state, and the press start preparation is performed. The press machine controller 11a of the control device 11 outputs a power transmission command to the switching mechanism 13 (the clutch in Fig. 1) that does not transmit the power from the servo motor 7 to the slider 5, and causes the switching mechanism. 13 switches to the power transmission state. Then, the press machine controller 11a outputs a hold release command to the slider holding mechanism 15 (the brake in FIG. 1) in the above-described slider holding state, and causes the slider holding mechanism 15 to switch to Non-holding state. Further, in step S1, the control device 11 continues the servo control for maintaining the servo motor 7 at a constant rotation angle.

In step S2, the slider 5 is lifted and lowered and pressed. The control device 11 lowers the slider 5 to perform press working of the workpiece 1, and again raises the slider 5 to stop the control at the target stop position. In this case, as described above, the press machine controller 11a of the control device 11 outputs a command rotation angle value in accordance with a preset slider operation mode, and the motor rotation angle encoder 17 outputs the detected rotation angle value of the servo motor 7. The servo controller 11b of the control device 11 compares the command rotation angle value with the detected rotation angle value to control the rotation angle of the servo motor 7 via the motor drive amplifier 11c in accordance with the command rotation angle value. During this period, the vertical movement of the slider 5 and the acceleration/deceleration are performed by the servo motor 7. Therefore, energy can be reduced by using the motor drive amplifier 11c capable of regenerating electric power when the servo motor 7 is decelerated, thereby reducing energy loss.

In order to maintain the slider 5 in the stop position, the press machine controller 11a outputs a certain command angle value corresponding to the slider stop position, and the servo controller 11b performs the rotation angle of the servo motor 7 and the predetermined command angle value. Consistent control. Thereby, the slider 5 is held at the target stop position.

Further, the target stop position is the position where the crank shaft 9a and the connecting rod 9b are at the highest position, that is, the top dead center of the slider 5, and may be other positions.

In step S3, after the slider 5 is stopped at the target stop position as described above, the press machine controller 11a outputs a slider holding instruction to the slider holding mechanism 15 to cause the slider holding mechanism 15 (in the example of Fig. 1 Brake) moves to the slider hold state. Thereby, the slider 5 is held at the target stop position.

Next, in step S4, the press machine controller 11a outputs a power non-delivery command (clutch split command) to the switching mechanism 13 (in the case of the clutch in the first figure), and causes the switching mechanism 13 to switch to the power non-conveying state (clutch separation) status). Thereby, in a state where the driving force of the servo motor 7 is not transmitted to the slider 5, the slider 5 is held at the target stop position by the slider holding force of the slider holding mechanism 15. Therefore, since the servo motor 7 is in a state in which only the servo motor 7 itself is driven, the slight forward/reverse motion by the servo control is repeatedly performed due to a slight difference between the command rotation angle value and the detection angle value. Only a small torque is produced. As a result, the current flowing through the servo motor 7 and the motor drive amplifier 11c becomes small.

In the slider stop state of step S4, the workpiece 1 that has been subjected to the press working is removed by a manual operation or an automatic conveying device, and the new workpiece 1 is placed on the lower mold 3b. After that, it returns to step S1. The stamping process is repeated as described above.

Further, during the above-described press working, the crankshaft rotation angle detected by the crankshaft rotation angle encoder 19 is input to the press machine controller 11a for confirmation of the operation. That is, when the switching mechanism 13 is in the power transmission state, the rotation angle of the servo motor 7 and the family rotation angle of the crankshaft 9a should be changed at the same ratio as the reduction ratio of the reduction gear 21, so that the press machine controller 11a is used comparatively. The rotation angle detected by the motor rotation angle encoder 17 and the rotation angle detected by the crankshaft rotation angle encoder 19 are determined to be abnormal if they are not changed at the same ratio as the reduction ratio of the speed reducer 21. When the slider holding mechanism 15 is in the state of the slider holding position, the crank shaft 9a should not rotate, so the stamping machine controller 11a checks Whether the crankshaft rotation angle has not changed, and if it is changed, it is judged to be abnormal. When it is determined that the abnormality is determined, the command rotation angle value is kept constant, the servo motor 7 is stopped, the switching mechanism 13 (clutch) is in the power non-transmission state, and the slider holding mechanism 15 (brake) is set as the slider. A state in which the power is supplied to the motor drive amplifier 11c (not shown) or the like, or a combination of these operations.

In the press machine 10 and the control method according to the embodiment of the present invention, the slider 5 is stopped by controlling the rotation angle of the servo motor 7, and then the slider holding mechanism 15 is operated to the slider holding state, and then the switching is performed. The mechanism 13 becomes a power non-transmission state. Therefore, in the stopped state of the slider 5, the slider 5 is held by the slider holding mechanism 15, so that it is not necessary to supply a current for holding the slider 5 at the stop position to the servo motor 7, and the servo motor 7 and the slider 5 are separated into a power non-transmission state, and the torque required for the forward and reverse rotation of the servo motor 7 is thus small, and as a result, the current supplied to the servo motor 7 can be made small. Therefore, the power consumption in the stop of the slider can be reduced.

Further, during the stop of the slider, the slight repeated forward/reverse motion of the servo motor 7 is not transmitted to the power transmission path from the position where the power transmission from the servo motor 7 is separated by the switching mechanism 13 to the slider 5. Therefore, there is no slight repetitive motion in the power transmission path. Therefore, it is possible to prevent the power transmission path from being deteriorated due to repeated contact with the tooth surface or the like between the gears.

Therefore, in the stop of the slider, the power consumption can be reduced and the deterioration of the power transmission mechanism caused by the meshing portion between the gears repeatedly contacting the tooth surface due to the forward and reverse movement of the servo motor 7 can be prevented.

Further, the above-described press machine 10 and its control method also have the following advantages: (1) In the stop of the slider, even if the power is not transmitted from the servo motor 7 to the slider 5, the two can be separated. The block holding mechanism 15 holds the slider 5 in the stop position.

(2) Since the slider holding mechanism 15 is actuated to the slider 5 that is being stopped, the friction between the slider holding mechanism 15 and the power transmission mechanism does not occur due to the braking action at the start of the operation. . Further, during the slider holding period, since the minute forward and reverse movement of the servo motor 7 is not transmitted to the slider 5, friction between the slider holding mechanism 15 and the power transmission mechanism does not occur during this period. heat.

(3) Similarly to the press machine using the conventional servo control, since the slider movement is controlled by the servo control, the movement of the slider from the rise to the stop and the stop to the fall can be performed in a short time.

(4) The energy can be regenerated by changing the supply power of the servo motor 7 in the deceleration of the slider, and the energy use efficiency is improved.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

For example, in the example of Fig. 1, the clutch 13 and the mechanical brake 15 are provided on the high speed shaft side of the speed reducer 21, that is, the structure is provided between the servo motor 7 and the speed reducer 21, but may be A configuration is adopted in which both the clutch 13 and the mechanical brake 15 are provided on the low speed shaft side of the speed reducer 21, that is, between the speed reducer 21 and the connecting rod 9b; or the clutch 13 is set at the high speed of the speed reducer 21. Shaft side, while the machine The brake 15 is provided on the low speed shaft side of the speed reducer 21.

Further, although the shifting mechanism 9 is constituted by the crankshaft 9a and the connecting rod 9b, a shifting mechanism that converts the rotational motion into a lifting motion by a link type, a toggle type, or a crankless type other than the crank shaft type may be used.

In the example of Fig. 1, the mechanism for supporting the slider 5 at one point is used, but a mechanism of supporting at two points, supporting at four points, and supporting at a plurality of points may be used.

Although the first figure shows the structure of one servo motor 7, a plurality of servo motors 7 may be used. When the configuration in which the plurality of servomotors 7 drive one crankshaft 9a is provided, only one set of the clutches 13, the mechanical brakes 15 may be provided between the plurality of servomotors 7 and the crankshafts 9a, or the servomotors 7 may be provided. A clutch 13 and a mechanical brake 15 are provided for each servo motor 7 between the crankshafts 9a. When the plurality of servomotors 7 are configured to drive the independent crankshafts 9a, the clutches 13 and the mechanical brakes 15 may be provided for each of the servomotors 7. ..

In the example of Fig. 1, the detecting means of the rotation angle of the servo motor 7 is the motor rotation angle encoder 17, but other detecting means may be used.

For example, in a state in which the clutch 13 is connected, the crankshaft rotation angle detected by the crankshaft rotation angle encoder 19 may be used instead of the motor rotation angle detected by the motor rotation angle encoder 17, by the servo controller 11b. The servo control of the servo motor 7 is performed.

Further, an inductor such as an optical scale that directly detects the position of the slider 5 may be provided, and the slider position detection value from the sensor may be used for the rotation angle control of the servo motor 7 by the servo controller 11b. At this time, the slider position can also be changed to the rotation angle of the servo motor 7, or the servo motor 7 can be used. The rotation angle is changed to the slider position, and the rotation angle control of the servo motor 7 is performed. The slider position detection value from the sensor may be used instead of the crankshaft rotation angle detected by the crankshaft rotation angle encoder 19 to confirm the progress of the operation.

Further, in the example of Fig. 1, the slider holding mechanism 15 is a mechanical brake, but may be another suitable mechanism for holding the slider 5 at the stop position. For example, the slider holding mechanism 15 may have the configuration shown in FIG. The slider holding mechanism 15 shown in FIG. 3 includes a gear 15a that is provided in the middle of the power transmission path for transmitting power from the servo motor 7 to the slider 5, and a snap fit that can be engaged with the teeth of the gear 15a. The engaging member 15b that moves between the position and the non-fastening position that is not engaged with the teeth of the gear 15a is held by the slider that restricts the lifting movement of the slider 5 when the engaging member 15b is in the engaged position. In the state, when the engaging member 15b is in the non-fastening position, it becomes a non-holding state in which the lifting movement of the slider 5 is not restricted.

In the example of Fig. 1, the predetermined slider operation mode is a "slider operation mode for imparting a desired slider motion" controlled by the rotation angle of the servo motor 7, but the present invention is not limited thereto. . In other words, the slider operation mode can be changed in accordance with various conditions such as the progress of the press working of the workpiece or the operation of the conveyance device of the workpiece. For example, the deformation state of the panel member can be detected at any time during press forming, and the slider operation mode can be changed according to the situation. At this time, the changed slider operation mode may be referred to as "the slider operation mode for giving the desired slider motion".

1‧‧‧Processed materials

3a‧‧‧Upper mold

3b‧‧‧ Lower mold

5‧‧‧ Slider

7‧‧‧Servo motor

9‧‧‧Transformation agency

9a‧‧‧ crankshaft

9b‧‧‧ Connecting rod

10‧‧‧ Stamping machine

11‧‧‧Control device

11a‧‧‧Stamping machine controller

11b‧‧‧Servo controller

11c‧‧‧Motor Drive Amplifier

13‧‧‧Clutch (switching mechanism)

15‧‧‧Brake (slider retention mechanism)

15a‧‧‧ gear

15b‧‧‧fastening components

17‧‧‧Motor Rotary Angle Encoder

19‧‧‧Crankshaft Rotation Angle Encoder

21‧‧‧Reducer

23‧‧‧ board

25‧‧‧ frame

27‧‧‧ balancing device

27a‧‧‧Piston

Fig. 1 is a structural view of a press machine according to an embodiment of the present invention.

Fig. 2 is a flow chart showing a method of controlling a press machine according to an embodiment of the present invention.

Fig. 3 is a view showing another configuration example of the slider holding mechanism.

1‧‧‧Processed materials

3a‧‧‧Upper mold

3b‧‧‧ Lower mold

5‧‧‧ Slider

7‧‧‧Servo motor

9‧‧‧Transformation agency

9a‧‧‧ crankshaft

9b‧‧‧ Connecting rod

10‧‧‧ Stamping machine

11‧‧‧Control device

11a‧‧‧Stamping machine controller

11b‧‧‧Servo controller

11c‧‧‧Motor Drive Amplifier

13‧‧‧Clutch (switching mechanism)

15‧‧‧Brake (slider retention mechanism)

17‧‧‧Motor Rotary Angle Encoder

19‧‧‧Crankshaft Rotation Angle Encoder

21‧‧‧Reducer

23‧‧‧ board

25‧‧‧ frame

27‧‧‧ balancing device

27a‧‧‧Piston

Claims (2)

A stamping machine having: an upper mold and a lower mold, the workpiece is clamped in the up and down direction for punching; the slider is fixed with an upper mold for lifting movement; the servo motor is used to make the slider And a shifting mechanism that decelerates the rotational motion of the servo motor by a speed reducer and converts the rotational motion into a lifting motion by the crankshaft and transmits the motion to the slider; the punching machine has a control device that is used to The desired rotation angle value of the slider operation mode of the slider movement is compared with the detection value of the rotation angle of the servo motor, and the rotation angle of the servo motor is controlled in accordance with the command rotation angle value; the switching mechanism is set Selectively switching between a power transmission path from the servo motor to the slider: a power transmission state in which power from the servo motor is transmitted to the slider, and a power non-transmission state in which power from the servo motor is not transmitted to the slider; And the slider holding mechanism is selectively switched: an unretained state in which the lifting movement of the slider is unrestricted, and a lifting of the slider a motion-restricted slider holding state; and the control device switches the slider holding mechanism to the slider holding state after the slider is stopped by the rotation angle control of the servo motor, and then switches the switching mechanism The power transmission non-transmission state; when the switching mechanism is in the power transmission state, the control device compares the detected value of the rotation angle of the servo motor with the foregoing The detected value of the rotation angle of the crankshaft is determined to be abnormal when the detected values are not changed by a ratio equivalent to the reduction ratio of the speed reducer; and when the slider holding mechanism is in the slider holding state, When the detected value of the rotation angle of the crankshaft changes, it is determined to be abnormal. A control method for a press machine, the press machine having: an upper mold and a lower mold, the workpiece is clamped in the up and down direction for punching; the slider is fixed with an upper mold to perform lifting movement; the servo motor is And the changing mechanism is configured to reduce the rotational motion of the servo motor by the reducer and convert the rotary motion into a lifting motion by the crankshaft and transmit the motion to the slider; the control method has the following features: The switching mechanism of the following two states is provided in a power transmission path from the servo motor to the slider: the power transmission from the servo motor is transmitted to the power transmission state of the slider, and the power from the servo motor is not transmitted to the slider. a power non-transmission state; a slider holding mechanism that selectively switches the following two states: a non-holding state in which the lifting movement of the slider is unrestricted, and a slider holding state in which the lifting movement of the slider is restricted; According to the command rotation angle value for giving the desired slider movement mode, and the detection value of the rotation angle of the servo motor Comparing, the rotation angle of the servo motor is controlled in accordance with the above-mentioned command rotation angle value, thereby lowering the slider to perform punching, and then raising the slider and stopping at the target stop position; after the slider stops at the target stop position To keep the aforementioned slider The mechanism is switched to the slider holding state; after the slider holding mechanism is switched to the slider holding state, the switching mechanism is switched to a power non-conveying state; and when the switching mechanism is in the power transmitting state, the servo is compared The detected value of the rotation angle of the motor and the detected value of the rotation angle of the crankshaft are determined to be abnormal when the detected values are not changed by a ratio equivalent to the reduction ratio of the speed reducer; and when the slider holding mechanism is When the slider is held, if the detected value of the rotation angle of the crankshaft changes, it is determined to be abnormal.