JP2012011449A - Press machine and controlling method of press machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a servo press machine which can control acceleration and deceleration in response to a rotation speed and output torque characteristics of a servo motor by previously specifying operation corresponding to a production purpose of a user.SOLUTION: Either operation mode is set out of an operation priority mode which is an operation mode of a rotation speed for starting field weakening control, a customer priority mode which is an operation mode of a lower rotation speed than the operation priority mode, and a production priority mode which is an operation mode of a higher rotation speed than the operation priority mode. Depending on the set operation mode, servo control on the servo motor is set by servo parameters including a maximum non-machining speed, an acceleration and deceleration time constant, and an acceleration and deceleration termination rounding constant. In the customer priority mode, the acceleration and deceleration time constant is reduced, and a change of the acceleration and deceleration is increased. In the production priority mode, the acceleration and deceleration time constant is increased and the change of the acceleration and deceleration is reduced.

Description

  The present invention relates to a press machine and a control method of the press machine, and in particular, when performing servo control of a press machine that drives a crankshaft by a servomotor to move a slide up and down, it is optimal for a production purpose. The present invention relates to a press machine suitable for giving various parameters and a control method of the press machine

  The servo press machine is a device that performs motion control with a servo mechanism, and can control the position, speed, and energy at the time of machining freely and with high precision, and it enables high productivity, low noise, energy saving, etc. Has characteristics.

  As an acceleration / deceleration control method of this servo control, the conventional technique is a method in which the acceleration of the motor is made constant even when the SPM (Strokes Per Minute) of the press operation set by the press operator changes. It is common. This acceleration is obtained from the acceleration / deceleration time of the servo motor with respect to the maximum press non-working speed calculated from the maximum motor speed and the gear ratio.

  Patent Document 1 discloses a servo press machine that performs servo control using a servo parameter table that defines an acceleration / deceleration time constant corresponding to the length of a stroke.

  Patent Document 2 discloses a punch press that determines an acceleration / deceleration time constant for controlling the ram speed according to the distance and movement time of a plate material.

JP 2000-263299 A JP 2001-198632 A

  In general, when controlling a servo motor of a press machine, if it is desired to process with high productivity as much as possible, it is designated by an operation motion that causes the servo motor to continuously operate at the highest speed without specifying a shift. In particular, when controlling a servo press machine, a setting with higher productivity than other motions can be performed during a pendulum machining operation (pendulum motion). Therefore, especially in the case of pendulum motion, the non-processing speed is set to the maximum non-processing speed in order to shorten the time other than the pressure processing operation in order to obtain higher productivity. However, there is a strong demand for setting the minimum required distance.

  On the other hand, in the pendulum motion, after the deceleration operation of the servo motor at the end of the slide stroke, the motor turning direction is switched and the acceleration operation is performed. Therefore, an acceleration / deceleration operation time and an acceleration / deceleration distance corresponding to the target SPM are required. For this reason, if the slide stroke necessary for the acceleration / deceleration operation at the end of the pendulum operation is not set at the setting stage of the press operation motion, the motion setting is defective. The servo parameters in the acceleration / deceleration operation at this time are calculated in the worst case based on the motor output torque at the maximum motor speed determined for each press model.

  Also, when performing acceleration / deceleration in the molding process area, the acceleration / deceleration operation is calculated in the worst case based on the motor output torque at the maximum motor speed determined for each press model. In the acceleration / deceleration operation, an excessive acceleration / deceleration time is consumed, which leads to a decrease in productivity, and there is a problem that the productivity of this motor cannot be reduced by reducing the excess acceleration / deceleration time.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to specify operation in advance according to the production purpose of the user and to accelerate / decelerate according to the rotation speed and output torque characteristics of the servo motor. The purpose of this is to provide a highly productive servo press machine.

  In the press machine that drives the slide by the servo motor of the present invention, the operation priority mode that is the operation mode of the rotational speed at which the field-weakening control is started, the customer priority mode that is the operation mode of the lower rotational speed, the higher rotational speed One of the production priority modes, which are operation modes, is set.

  When the customer priority mode is set, the maximum non-machining speed is input to the press user.

  Then, in accordance with the set operation mode, the servo motor is set to perform servo control with the servo parameters including the maximum non-machining speed, the acceleration / deceleration time constant, and the acceleration / deceleration terminal rounding constant.

  In the customer priority mode, which is an operation mode with a small number of revolutions, the acceleration / deceleration time constant is reduced and the change in acceleration / deceleration is increased. And reduce the acceleration / deceleration change.

  As a result, it is possible to specify the operation according to the production purpose of the press user in advance, and the optimum servo parameters are set according to the characteristics of the rotational speed of the servo motor and the output torque.

  According to the present invention, a high-productivity servo press machine can be realized by performing operation designation in accordance with the production purpose of the user in advance and controlling acceleration / deceleration according to the rotation speed and output torque characteristics of the servo motor. Can be provided.

1 is a perspective view of a servo press machine according to an embodiment of the present invention. It is the schematic of the structure of the servo press machine which concerns on one Embodiment of this invention. It is a related figure of a servo motor rotation speed and output torque. It is a figure showing the relation between time and slide speed in order to explain acceleration / deceleration operation. It is a figure which shows the example of the servo parameter for every mode. It is a figure which shows an example of a control action setting screen. It is a flowchart which shows operation | movement of the control part 32 when setting control action.

  Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. 1 to 7.

First, a servo press machine according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a perspective view of a servo press machine according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of a configuration of a servo press machine according to an embodiment of the present invention.

  In the present embodiment, as an example of a servo press machine, a description will be given by taking a crank press, which is a press in which a mechanism / form for moving a slide is a crank mechanism, as an example.

  As shown in FIG. 2, the crank press drives a servo motor 10 that performs servo control as power, rotates the motor shaft 11, and rotates the motor shaft gear 12 in mesh with the main gear 20. A crankshaft 21 is attached to the center of the main gear 20, and converts the rotational movement of the main gear 20 into up and down movement. Thereby, the connecting rod 22 and the slide 23 attached to the crankshaft 21 move up and down. An upper mold 24 a is attached to the slide 23, and a lower mold 24 b is mounted on the bolster 25, which is a stationary base, and the upper mold 24 a and the lower mold 24 are lowered by lowering the slide 23. A molded part is sandwiched between the molds 24b and pressed.

  When the servo motor 10 rotates, the encoder 13 feeds back the rotation direction and rotation amount to the servo controller 15. The servo controller 15 has a function of performing servo control in accordance with a given servo parameter 41 and gives a control signal to the driver 14. The driver 14 converts the input signal into a current value and supplies it to the servo motor 10.

  The servo parameter 41 given to the servo controller 15 is set according to the designation of the operation panel 31 and the one stored in the servo parameter storage unit 40 is given.

  The control unit 32 and the servo parameter storage unit 40 are stored in the control panel 30 shown in FIG.

Next, the operation of the servo press machine according to the embodiment of the present invention will be described with reference to FIGS.
FIG. 3 is a diagram showing the relationship between the servo motor speed and the output torque.
FIG. 4 is a diagram showing the relationship between time and slide speed in order to explain the acceleration / deceleration operation.
FIG. 5 is a diagram showing examples of servo parameters for each mode.

  Acceleration / deceleration operating conditions are an important factor for increasing the productivity of servo presses, and it is necessary to set the acceleration / deceleration time as short as possible. The factor that determines the acceleration / deceleration time is the motor torque value of the servo motor 10. Therefore, in this embodiment, paying attention to the rotation speed and output torque characteristics of the servo motor, the motor rotation speed is divided into three operation modes of production priority designation, operation priority designation, and customer priority designation for the production purpose of the press user. It is designed to be able to specify the combined operation in advance.

  In general, the output torque of the servo motor 10 is maximum when the motor is stopped, and gradually decreases as the rotational speed increases. In particular, there is a rotation speed at which the motor rotation speed rises and the current supply motor torque greatly decreases due to voltage generation inside the motor, but weakening field control is activated at this motor rotation speed to reduce the motor output torque, Get the maximum motor speed. Field weakening control is control that suppresses the current that flows through the field of the motor in order to weaken the back electromotive force.

  The motor speed at the start of control for enabling this field weakening control is set as “operation priority speed”, and the maximum motor speed, that is, the production priority speed is obtained by field weakening control.

  The limit motor rotational speed at which the motor torque starts to greatly decrease is defined as “operation priority rotational speed”. The maximum motor rotation speed for each press model is set as “production priority rotation speed”, and for example, 50% of this “production priority rotation speed” is set as the initial value of “customer priority rotation speed”.

  The servo parameters can be specified by the user as the operation modes of “operation priority mode”, “production priority mode”, and “customer priority mode” at each rotation speed.

  For example, as shown in FIG. 5, the acceleration / deceleration time constant of the servo parameter and the acceleration / deceleration terminal rounding constant are taken. Here, each mode is determined by the maximum non-machining speed. The acceleration / deceleration time constant is the time for the non-machining speed to change from the lowest speed to the highest speed. Here, the minimum speed is set to 0 SPM, and the maximum speed is set to 80 SPM, which is the maximum non-machining speed when production is prioritized. The acceleration / deceleration end rounding constant is a time during which a certain amount of fluctuation of the press machine due to acceleration / deceleration can be absorbed. Note that the maximum non-machining speed originally means the speed when the slide is not machined, but here, it is expressed in units of SPM representing the production amount.

  Customer priority when the maximum non-machining speed is specified at 60 SPM, the acceleration / deceleration time constant is 120 mS, the acceleration / deceleration end rounding constant is 50 mS, and the maximum non-machining speed is specified at 40 SPM. The acceleration / deceleration time constant and acceleration / deceleration end rounding constant are as follows.

Constant calculation coefficient Y = 40 [spm] ÷ 60 [spm]
Acceleration / deceleration time constant 120 [mS] x Y = 80 [msec]
Acceleration / deceleration end rounding constant 50 [mS] × Y = 33 [msec]
That is, it is determined so as to be proportional to the maximum non-machining speed of operation priority. This servo parameter is merely an example, and in practice, an optimum value adapted to the characteristics of each press machine is obtained.

  The acceleration / deceleration time constant is as shown in FIG. Since the acceleration / deceleration time constant is the change time when changing from 0 SPM to 80 SPM, the inclination of acceleration / deceleration at the time of production priority is 80/160 = 0.50, and the inclination of acceleration / deceleration at the time of operation priority is 80 / 120≈0.67 (note that the non-machining speed change when the operation is prioritized is 0 to 60 SPM), and the acceleration / deceleration slope when the customer is prioritized is 80/80 = 1. 0 (note that the change in the non-machining speed when the customer is given priority is 0 to 40 SPM).

FIG. 4 shows the relationship between the slide speed and acceleration / deceleration. The time required to change from the maximum speed to the minimum speed is the acceleration / deceleration time constant. Conventionally, as indicated by δ ₀ in FIG. 4A, the acceleration / deceleration rate is constant regardless of the motor speed. In the present embodiment, as shown by δ in FIG. 4B, the acceleration / deceleration rate in each mode is made variable.

  The values of these servo parameters are set so as to be optimal parameters according to the characteristics of the rotation speed and output torque of the servo motor. Therefore, when the maximum non-machining speed is high, the acceleration / deceleration time constant is large (acceleration / deceleration time constant). When the maximum non-machining speed is slow, the acceleration / deceleration time constant is set to a small value (the acceleration / deceleration change is large), so that the production can be performed with the motion that increases the number of production.

Next, the mode specification of the press user will be described with reference to FIGS.
FIG. 6 is a diagram illustrating an example of the control operation setting screen.
FIG. 7 is a flowchart showing the operation of the control unit 32 when the control operation is set.

  The press user is given by the control operation setting screen displayed on the operation panel 31 shown in FIG. For example, in the “customer priority mode”, the “customer priority” portion is touched with the touch panel. In the “production priority mode” and “operation priority mode”, the maximum non-machining speed is fixed, but the maximum non-machining speed can be designated only when the “customer priority mode” is selected.

  When the control operation screen is selected and the customer-priority maximum non-machining speed is changed (S10), a numerical value is set (S20), servo parameters relating to acceleration / deceleration are calculated (S21), and the calculated conditions are stored. (S30), transferred, and stored in the servo parameter storage unit 40 (S40).

  When a mode is designated, the selected modes of production priority (S11), operation priority (S12), and customer priority (S13) are stored as setting conditions (S30), transferred, and stored as servo parameters. Stored in the unit 40 (S40).

  As described above, according to the present embodiment, the press user selects the acceleration switching parameter, and the productivity is highest with respect to the press speed used by the press user without being aware of the motor characteristics. The optimum press acceleration / deceleration parameters can be determined. As a result, the acceleration / deceleration time constant, which has conventionally been determined based on the state where the motor speed is the fastest, becomes a variable value with respect to the press speed. As a result, when the press speed is set at a low speed, the acceleration / deceleration speed increases and the production number increases. Furthermore, since it is possible to perform a large speed change operation in a short section, which has been conventionally determined that the operation cannot be performed due to a lack of the adjustment region, it is possible to set more flexible machining conditions.

  In particular, in the pendulum motion, it was possible to set the turn-up point to a higher position due to the lack of acceleration / deceleration area in the past, but it became possible to set it to a lower position, reducing the amount of unnecessary movement. This not only increases the number of production, but also leads to suppression of energy consumption by reducing unnecessary movement sections for unnecessary acceleration / deceleration operations.

  DESCRIPTION OF SYMBOLS 10 ... Servo motor, 11 ... Motor shaft, 12 ... Motor shaft gear, 13 ... Encoder, 14 ... Driver, 15 ... Servo controller, 20 ... Main gear, 21 ... Clan, 22 ... Connecting rod, 23 ... Slide, 24a ... Upper metal Mold, 24b ... Lower mold, 25 ... Bolster, 30 ... Control panel, 31 ... Operation panel, 32 ... Control part, 40 ... Servo parameter storage part, 41 ... Servo parameter.

Claims (5)

In a press machine that drives a slide by a servo motor,
Set the operation mode according to the rotation speed of the servo motor,
A press machine that performs servo control of the servo motor according to a servo parameter based on the operation mode.   The press machine according to claim 1, wherein the servo parameters are a maximum non-machining speed, an acceleration / deceleration time constant, and an acceleration / deceleration end rounding constant.   2. The press machine according to claim 1, wherein the operation mode is classified according to a rotation speed at which field-weakening control is started for the servo motor.   2. The press machine according to claim 1, wherein the acceleration time constant is reduced when the rotation speed of the servo motor is small, and the acceleration time constant is increased when the rotation speed of the servo motor is large. In the control method of the press machine that drives the slide by the servo motor,
The operation priority mode that is the operation mode of the rotational speed at which the field-weakening control is started, the customer priority mode that is the operation mode of the lower rotational speed, or the production priority mode that is the operation mode of the higher rotational speed is selected. Steps to set,
A procedure for inputting a maximum non-machining speed when the customer priority mode is set;
According to a set operation mode, and a procedure for setting the servo motor to perform servo control by a servo parameter including a maximum non-machining speed, an acceleration / deceleration time constant, and an acceleration / deceleration end rounding constant. A control method for a press machine.

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