JP2851653B2 - Control method of motor press machine - Google Patents

Description

The present invention relates to a method for controlling a motor press.

(Prior Art) In a punching process of a lead frame, a forming process of a lead, and the like, a press machine using hydraulic pressure has been frequently used because a constant pressing force can be easily and stably obtained. However, these hydraulic presses have recently been processed by motor presses due to the problem of becoming a source of contamination such as dust and oil.

Conventional motor press machines rotate the drive motor in one direction to repeatedly press.Adjustment of the press force is also about adjusting the press ram, so fine adjustments can not be made and there are many variations in press force, It is unsuitable for use in fine processing such as lead frames.

In view of this, the present applicant has developed a motor press that uses a motor by rotating the motor forward and backward as a press that is a motor press and that can perform high-precision press working. In this motor press machine, a press ram is connected to a motor that rotates forward and backward, and the amount of movement of the press ram is regulated by the amount of rotation of the motor, thereby enabling stable press working.

(Problems to be Solved by the Invention) By the way, in the actual press work, since various kinds of products must be handled and various work operations must be performed, even if the same press machine is used, each work operation is performed. It is common practice to replace and attach a press die suitable for the work, and therefore, when the press die is replaced, setting work such as setting a press load each time is essential.

In press working, when the press mold is pressed, the pressurized body also bends, and the reaction force is applied to the workpiece.If the rigidity of the pressurized body is different or the press mold is different, the same product can be obtained. There is a problem that it disappears. This is due to the fact that the same processing conditions are not set just by making the physical parameters the same, such as matching the protruding length of the press ram. In order to obtain the optimum value, a method of matching the press loads actually applied to the workpiece is optimal. In fact, a constant product can be obtained by keeping the pressing load applied to the workpiece constant.

Also, as described above, recently, there are many types of press dies due to handling various products, and there is a press load value most suitable for each processing operation. Therefore, when the press die is replaced and mounted, setting must be performed in accordance with individual processing conditions, and handling must be extremely complicated in a normal setting method.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to set a press die in a motor press machine, prior to a normal continuous press working, and to use a motor press machine. It is an object of the present invention to provide a control method for a motor press machine which can set the optimum press load value and make setting work extremely easy.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

That is, a press ram is driven by a forward / reverse rotating motor, and in a method of controlling a motor press machine that controls the amount of rotation of the motor to control the amount of the press ram entering and exiting from a press head. A load cell for detecting a press load when an object is pressed is provided, and prior to a normal continuous press operation, when a press die is set in the motor press machine, an optimum press load value of the press die is set. Entering and storing identification data for the control unit, the control unit activates the motor to press-work a plurality of workpieces on a trial basis,
While detecting the press load value at the time of test press working by the load cell, an encoder signal when the motor is rotated up to the optimal press load value stored in advance is sampled to calculate an average value, and the average of the encoder signal is calculated. A value is set as a control pulse value of the motor, and a normal continuous press working operation is performed while controlling the number of rotations of the motor based on the control pulse value by the control unit.

According to the control method of the motor press machine, prior to a normal continuous press working operation, when a press mold is set in the motor press machine, identification data relating to an optimum press load value of the press mold is controlled by the control unit. And memorize it.
The control unit executes a bottom dead center setting program, starts the motor, press-workes a plurality of workpieces on a trial basis, and stores in advance while detecting a press load value at the time of test press working by the load cell. Since the average value is calculated by sampling the encoder signal when the motor is rotated up to the optimum press load value, and the average value of the encoder signal is set as the control pulse value of the motor, the press die Setting work of the optimal press load value can be performed very easily.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a motor press controlled by a control method for a motor press according to the present invention. This motor press machine has a press ram 12
Is supported, one end of a connecting rod 14 is axially mounted on the upper end of the press ram 12, and the other end of the connecting rod 14 is axially mounted on a side surface of the sector gear 16.
The sector gear 16 is a sector-shaped gear having a substantially 1/4 circle shape, and a pinion gear 18 meshes with the sector gear 16. The pinion gear 18 is connected to the main body 10 via a pulley provided on the side of the main body 10.
It is connected to a motor 20 fixed to the outer side surface of 10. motor
Reference numeral 20 denotes a servomotor whose rotation amount of the output shaft is controlled by the number of input pulses.

In addition, a rod cell 28 is installed between the tie rod 26 and the top base 24 on the tie rod 26 connecting the bottom base 22 and the top base 24. The load cell 28 detects the pressing force when the press ram 12 presses the press die as a press load on the workpiece. There is no limitation between the base 24 and the tie rod 26.

In the motor press described above, the pinion gear 18 and the sector gear 16 meshing with the pinion gear 18 rotate forward and reverse with the forward and reverse rotation of the motor 20, and the press ram 12 moves up and down via the connecting rod 14. Whereas the conventional motor press machine only rotates the motor in one direction, the motor press machine of the present embodiment sets the amount of movement of the press ram 12 by rotating the motor 20 in the forward and reverse directions, that is, arbitrarily sets the press load. can do.

Since the movement amount of the press ram 12 is determined by the rotation angle of the sector gear 16, the rotation angle of the sector gear 16 is
By setting accurately by 20, the pushing position of the press ram 12 can always be set to a constant height position. In the embodiment, the output shaft of the motor makes one rotation (360 °) with the number of encoder pulses of 6000. Therefore, by setting the number of control pulses as appropriate, it is possible to set with extremely high accuracy.

Since the press ram 12 is pushed in connection with the sector gear 16, the pressing force applied to the workpiece varies depending on the position of the sector gear 16 during pressing. FIG. 2 schematically shows the position of the sector gear 16 at the time of machining. FIG. 2 (a) shows a state in which the press ram 12 is almost pressed at the bottom dead center, and FIG. 2 (b) shows a bottom dead center. It is in the state of being pressed somewhat above the point.

When the sector gear 16 approaches the bottom dead center, the sector gear
The amount of linear movement of the press ram 12 is extremely small compared to the amount of rotation of 16. For example, when the rotation angle of the sector gear 16 is about 0.1 ° near the bottom dead center, the vertical movement of the press ram 12 is about 0.0001. From this, it can be seen that the fine adjustment of the press shut height can be performed at an ultra-high resolution, and high-precision processing becomes possible.

Further, as the sector gear 16 approaches the bottom dead center, an extremely large press load is applied. The following shows an example of how the press load changes when the crank angle from the bottom dead center is changed. Four types of press force of the press drive section are shown: 1.2 tons (A), 1.8 tons (B), 2.1 tons (C), and 2.8 tons (D).

Crank angle ABCD 0 Infinity 〃 〃 〃 1 12.50 18.00 21.00 28.73 2 6.25 9.00 10.50 14.36 3 4.16 6.00 7.00 9.58 5 2.50 3.60 4.20 5.75 10 1.25 1.80 2.11 2.88 15 0.84 1.21 1.41 1.93 30 0.43 0.62 0.73 1.00 As described above, since the press load varies depending on the crank angle in the press working, the press load can be easily changed according to the content of the working operation. Since the press force applied to the workpiece varies depending on the crank angle, it is necessary to adjust the press load using an adjust washer 32 or the like in accordance with the content of the press work so as to obtain an appropriate press load. .

In this embodiment, the following control method is adopted as a control method of the motor press machine so that various processing operations can be easily performed.

That is, a press die designed in advance according to the work content is provided for the processing operation, and the individual press die is supplied with the optimum press load value when using the press die. . Here, the press die is provided with an identification mechanism for identifying the type of the press die. The identification mechanism may be based on the pin arrangement of the connector part of the press die or the bar code.

Further, data of a plurality of types of press dies to be attached to the motor press and used is input to the motor press, and stored in the control unit. That is, the optimum press load value of the press die together with the identification data of the press die, for example, the press die A
Data such as 800 kgf and 400 kgf for the press die B are registered in advance.

With the above configuration, when the press die is attached to the motor press, the motor press automatically identifies the press die and loads the control unit with the optimum press load value for the press die. As a result, the motor press is automatically set to an initial state in which processing is started using the press die.

From this setting state, the motor press executes the bottom dead center setting program for performing continuous machining,
Proceed to the actual machining operation. Hereinafter, this method will be described with reference to the block diagram shown in FIG.

In the figure, reference numerals 40 and 41 denote load cells for detecting a press load on the workpiece. The output of the load cell 40 is input to the bottom dead center setting system, and the output of the load cell 41 is input to the emergency stop unit 42. The emergency stop section 42 limits the upper limit of the press load so that an excessive press load is not applied to the press die and the motor press machine main body. Automatically stop press ram descent when it reaches.

The bottom dead center setting system 44 includes a reading unit 46 for bottom dead center detection data associated with the press die such as an identification number of the press die and a set press load value, an encoder signal input unit 48 of a motor at the time of sampling, And a statistical processing unit 50 for encoder signals.

At the time of setting the bottom dead center, the work is actually pressed a plurality of times, and the average value is set by sampling the encoder signal of the motor (specifying the amount of movement of the press ram) at that time. At the time of this sampling, the press ram descends until the press load value reaches a preset press load value, and when the press load reaches the press load set value, the encoder signal is transmitted to the encoder signal input section 48.
Read by. When the press load set value is reached,
The descent of the press ram is stopped. When the bottom dead center is set, the press ram is stopped without deceleration, and the motor is rotated at an extremely low speed so that the press ram does not overrun. As a result, an accurate control value (number of pulses) is set.

52, 54, 56, and 58 are control mechanisms of the motor press at the time of setting the bottom dead center, and 25 is the optimal press load value and load cell 40.
The stop unit inputs a stop signal to the stop unit 54 when the press load value for the workpiece matches the press load set value set as the optimum value.
54 is controlled by a stop timer 56 to stop the press ram for a certain period of time, and after a lapse of a certain period of time, the press ram is turned upside down by an ascent unit 58.

After the sampling is performed a plurality of times as described above, the average value of the encoder signal of the motor is obtained in the statistical processing unit 50, and the average value is set as the pulse value for controlling the motor during the normal machining operation. Even in the case of the same press load setting value, in actual machining, since there is a slight variation in the encoder signal of the motor, the average value of these is set as the control value (number of pulses) in the actual machining operation.

Reference numeral 43 denotes a press load range setting unit for designating a permissible range of a change in the press load value for the processing operation with respect to the press load set value. For example, when the pressing load is out of the range, it becomes easy to indicate that a product defect occurs.

In the case of a bending press die, it is checked whether a product formed by sampling is formed into a predetermined shape by inspection. Even when using the same type of press die, there is a tolerance in the processing accuracy of the die, and the thickness of the workpiece may vary slightly depending on the lot. This is because the press load value set in the above may not be formed into a predetermined shape.

If the predetermined molded shape has not been obtained, a correction signal is externally input from the external correction unit 60 to the servo control unit 62 to correct the press load value, and the sampling operation is performed again. When a normal molded shape is obtained by performing such sampling, the control value at that time is finally set as the control value of the normal machining operation. The control value is input to the servo control unit 62, and the setting for starting the normal machining operation is completed by switching to the position control of the press ram by the servo motor.

At the time of the above-mentioned sampling, it is also possible to make the motor press machine linked to the machine for inspecting the processed product and to correct the motor press machine based on the command of the inspection result from the machine.

Reference numerals 64, 66, and 68 denote control mechanisms of the motor press during a normal machining operation. The servomotor is controlled by the stop unit 64, the stop timer 66, and the ascending unit 68 to perform press working. In this normal machining operation, the machining speed is set to be higher than in the case of the above-described bottom dead center setting system. This is because the number of palaces for controlling the motor is determined by the above-described bottom dead center setting system, so that the motor press machine may be operated according to the control value. Since the press ram is controlled to be pressed by a pulse-controlled motor, the press ram can always be pressed with a constant press load, thereby enabling high-precision processing to be performed without variation in products.

As described above, even if the products are of the same type, there is a slight difference between lots. Therefore, when the lot changes during operation or when using a spare press die, the above bottom dead center setting program In order to shift to the normal machining operation.

Thus, in the actual work, it is necessary to reset the setting as appropriate, but in the case of this apparatus, the standard press load value of the press die is automatically set by attaching the press die to the motor press machine. Since the bottom dead center setting system can be operated, the setting of the apparatus can be made extremely easy, and even when different types of press dies are replaced and mounted, the setting can be made very easily.

In order to monitor the processing contents during the normal processing operation, the peak value of the press load value is held each time by the peak hold unit 70, the peak value is digitally converted by the A / D conversion unit 72, and the output signal is output. It is input to the determination unit 74. The determination unit 74 determines whether the press load value is within the allowable range of the initially set upper and lower limits of the press load, and the display unit 76 displays the determination result by, for example, LED display. On the other hand, the peak value is input to the data totaling unit 78 and subjected to data processing. The data aggregation results can be used for production management.

In this way, the motor press machine is controlled as a whole, can be used for the production of various types of products easily, can be easily and reliably processed, and can be controlled for production It is.

As described above, the control method of the motor press according to the present invention has been described with respect to the configuration and the control method of the motor press. It is needless to say that various modifications can be made therein.

(Effects of the Invention) According to the control method for a motor press machine according to the present invention, prior to a normal continuous press working operation, when a press mold is set in the motor press machine, an optimal press of the press mold is performed. The identification data relating to the load value is input to and stored in the control unit, and the control unit executes a bottom dead center setting program, starts the motor, press-tests a plurality of workpieces on a trial basis, and loads the load cell. By detecting the press load value at the time of test press working, sampling the encoder signal when the motor is rotated up to the optimal press load value stored in advance and calculating an average value, and calculating the average value of the encoder signal. Since it is set as the control pulse value of the motor, the setting work of the optimum press load value of the press die can be performed very easily. Further, the control unit includes:
Since the normal continuous press working operation is performed while controlling the number of rotations of the motor based on the control pulse value, the working accuracy can be improved.

Also, by setting a permissible range of the press load set value detected by the load cell, and by stopping the press ram descent when the detected press load value reaches the upper limit, especially in the case of a bending mold. Since even the same type of press mold may have different molding shapes, a guide for product defects is set according to the product and advanced quality control is performed by suppressing variations in processing accuracy between products. be able to.

Further, at the time of the test press working, if a predetermined molded shape is not obtained, by performing a sampling operation by correcting the optimum press load value by inputting a correction signal from the external correction unit to the servo control unit, The press load value can be finely adjusted in accordance with the thickness of the workpiece to be formed into a predetermined shape, and the occurrence of defective products can be suppressed and the yield can be improved.

In addition, when the press die is mounted on a motor press to replace it with another press die, the control unit executes a bottom dead center setting program to set an optimum press load value of a control mechanism of the motor press. Since the setting of the optimum press load value can be easily performed even when other types of products are produced, the versatility and convenience of the motor press can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a motor press to which a control method of a motor press according to the present invention is applied, FIG. 2 is an explanatory view showing a use state, and FIG. 3 is a block diagram showing a control method. It is. 10 ... body, 12 ... press ram, 20 ... motor, 28 ...
Mode cell, 30 press die, 40, 41 load cell, 44 bottom dead center setting system, 48 encoder signal input section, 50 statistical processing section, 62 servo control section.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-148498 (JP, A) JP-A-63-180400 (JP, A) JP-A-3-155497 (JP, A) Real-life Sho-62 67695 (JP, U) Japanese Utility Model 63-170097 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B30B 15/14

Claims (3)

(57) [Claims] 1. A control method for a motor press, wherein a press ram is driven by a forward / reverse rotating motor, and the amount of rotation of the motor is controlled to control the amount of the press ram coming in and out of a press head. A load cell for detecting a press load when the workpiece is pressed is provided, and prior to a normal continuous press working operation, when the press mold is set in the motor press machine, the optimal press mold is used. The identification data relating to the press load value is input to and stored in the control unit, and the control unit activates the motor to press-work a plurality of workpieces on a trial basis, and the press load value at the time of test press work by the load cell. Sampling the encoder signal when rotating the motor up to the optimal press load value stored in advance while detecting Is calculated, the average value of the encoder signal is set as a control pulse value of the motor, and a normal continuous press working operation is performed while controlling the number of rotations of the motor based on the control pulse value by the control unit. A method for controlling a motor press machine, characterized in that: 2. An apparatus according to claim 1, wherein a permissible range of the press load value detected by said load cell is set, and when the detected press load value reaches an upper limit, lowering of the press ram is stopped. The control method of the motor press described in the above. 3. In the test press working, if a predetermined formed shape cannot be obtained on the workpiece, a correction signal is inputted from an external correction unit to a servo control unit to correct the optimum press load value. 3. The control method for a motor press according to claim 1, wherein a sampling operation is performed.