JP3939006B2 - Control device for linear motor press machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a linear motor press machine that performs press processing by reciprocating a slide by a linear motor.
[0002]
[Prior art]
There are various types of pressing, such as shearing, drawing, bending, and compression. Depending on the type of pressing, or depending on the material and shape of the workpiece, sliding or pressing It is desirable to change the slide speed at each movement position of the mold.
[0003]
For this reason, conventionally, a knuckle press that can reduce the sliding speed near the bottom dead center and enable coining, a friction press that allows variable stroke length and impact strength by operating the handle, or when not working Link presses with a high slide speed and a low slide speed during processing are manufactured and used.
[0004]
However, most of these various press machines are dedicated machines that are manufactured to perform predetermined press processing, so various press stroke curves can be easily changed with a single press machine. There is a demand for a press that can be realized by the above operation. Therefore, in recent years, a press machine having a structure in which a slide is reciprocated by a linear motor has been developed as a press machine that can arbitrarily and easily change a slide speed at each movement position of the slide.
[0005]
[Problems to be solved by the invention]
In this linear motor drive type press, a plurality of linear motors are arranged along the moving direction of the slide in order to obtain a desired thrust. It is guided so as to be slidable. For this reason, when simply pressing and controlling a plurality of linear motors to reciprocate the slide, if an eccentric load is applied to the slide due to uneven friction generated between the press die and the workpiece, etc. The problem is that the slide is likely to be inclined, and good press working cannot be performed.
[0006]
The present invention has been made in view of the above points, and even a press machine driven by a plurality of linear motors does not cause an inclination of a slide due to an eccentric load and can perform a good press process. It aims at providing the control apparatus of a motor press machine.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the control device for a linear motor press machine according to the present invention is configured such that the slide is reciprocally movable with respect to the main body frame, and a plurality of linear motors are moved in the slide direction in order to reciprocate the slide. In the control device of the linear motor press machine mounted toward the head , the moving frame is disposed in the main body frame so as to be able to reciprocate together with the plurality of guide posts, the slide is fixed on the guide post, and the slide guide post is fixed. A plurality of linear scales near the position and corresponding to each linear motor are mounted between the body frame and the body frame so as to detect the slide movement position and output the position detection signal. They are arranged a plurality of linear motors in the vicinity of the guide post, a unit based on the stroke curve chart when the slide is moved Pattern data storage means for sequentially storing position data and speed data created for each interval; during operation, position data and speed data are sequentially read from the pattern data storage means, and the position indicated by the position data is used as the target position for the speed data and control means for driving and controlling the linear motor at the speed indicated by, calculating a difference between the position detection data from the position detection data and other Riniasuke Le from advance one linear scale that is determined, the other based on the difference Correction means for correcting so as to reduce the difference between the position data and the speed data for the linear motor corresponding to the linear scale.
[0008]
[Operation and effect of the invention]
In the press machine having such a configuration, first, the stroke curve (pattern) of the slide of the press work to be performed on the stroke curve diagram in which the vertical axis represents the displacement amount (position) of the slide and the horizontal axis represents time. Enter.
[0009]
Next, from this stroke curve diagram, position data for each unit time, and speed data obtained from the time and displacement amount up to that time, are taken out in order, along with the line number, these position data and speed data are converted into position command values. And the speed command value are sequentially stored in the pattern data storage means.
[0010]
During operation, the position data and speed data for each time point are read in order from the pattern data, and the speed command value is output to the driver of the linear motor. The driver drives the linear motor according to the speed command value. Control. Thus, as a target value a slide of a press machine command position at a controlled rate, that is to move to the programmed pattern as previously specified, fixed to the slide the upper die is aligned with the lower mold on the body frame Then, press working is performed.
[0011]
At this time, the correction means calculates a difference between the position detection data from the position detection data and other Riniasuke Le from advance one linear scale which is determined, as the difference is reduced, the other Corrects the position data and speed data for the linear motor corresponding to the linear scale. Then, the control means outputs a speed command value of the corrected speed data, and drives and controls another linear motor using the corrected position command value as a target position.
[0012]
In this way, each linear motor is driven and controlled so that the position detection value from the linear scale corresponding to each predetermined motor is the same, and therefore, there is no problem occurring between the press die and the workpiece. Even when an eccentric load is applied to the slide during press processing due to uniform friction or the like, the slide is prevented from tilting, and good press processing can be performed.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the press, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is a plan view thereof. Reference numeral 1 denotes a main body frame of the press machine. Four thrust bearings 6 are provided on the inner bottom of the main body frame 1 and four thrust bearings 7 are provided on the upper part, and four guide posts 3 can be moved up and down there. Supported by Each of the four guide posts 3 is fixed to the vertically moving frame 5 in the main body frame 1.
[0014]
The bolster 2 is fixed to the upper part of the main body frame 1, and the slide 4 is fixed horizontally to the tips of the four guide posts 3 protruding upward from the main body frame 1 and the bolster 2. In the main body frame 1, four linear motors 8 to 11 are arranged to drive the vertical movement frame 5, the guide post 3, and the slide 4 up and down. Similar to a normal press, a lower die (not shown) is fixed on the bolster 2, and the upper die is fixed to the lower surface of the slide 4.
[0015]
The four linear motors 8 to 11 are respectively arranged in the vertical direction on the side of the vertical movement frame 5 inside the main body frame 1, and the coil sliders (stators) 8 a to 11 a of the respective linear motors 8 to 11 are used as the main body frame. The magnet plates (movers) 8b to 11b of the linear motors 8 to 11 are fixed to the vertical movement frame 5 side.
[0016]
Further, four linear scales 12 to 15 are disposed in the vicinity of the guide post 3 on the side of the slide 4 in correspondence with the linear motors 8 to 11. The stators 12 a to 15 a of the linear scales 12 to 15 are attached to the upper part of the main body frame 1 via brackets, and the movers 12 b to 15 b are attached to the vicinity of the guide post 3 on the side of the slide 4. The linear scale 12 to 15 as a position detector for detecting the position of the slide 4, for example, those of the absolute-type is used, the position data of the absolute position location is output.
[0017]
In the press machine having such a structure, the vertical movement frame 5, the guide post 3, and the slide 4 are driven up and down based on the controlled position data and speed data by the reciprocating drive of the linear motors 8 to 11, and the linear scale The current position data output from 12 to 15 is fed back and used for highly accurate control.
[0018]
FIG. 4 shows a connection state of the control unit 20 of the press machine and a linear motor connected thereto. The control unit 20 is configured with the CPU 21 as a main part, and controls the entire operation of the press machine based on program data stored in advance in a fixed memory. The control unit 20 is provided with a temporary memory 22 that can be read and written at any time, a display 23, and switches 24 for inputting or operating various setting values. The memory 22 stores previously written pattern data of the press operation program. Further, the memory 22 is provided with a memory area for storing the stroke length, SPM value (number of strokes per minute), die height set value, number of press settings, etc. that have been set and input. The set stroke length, SPM value (number of strokes per minute), die height set value, number of press settings, etc. are displayed on the display 23 that displays the setting screen.
[0019]
The linear scales 12 to 15 are connected to an interface circuit in the control unit 20 and send readings of the respective linear scales 12 to 15, that is, position detection data of the slide 4 to the control unit 20. Drivers 16 to 19 are connected to the four linear motors 8 to 11, respectively, and the drivers 16 to 19 are connected to an interface circuit in the control unit 20. As the linear motors 8 to 11, for example, an AC servo motor (synchronous motor) type with a large thrust is used, and the drivers 16 to 19 have, for example, a converter and an inverter for PWM control. The linear motors 8 to 11 are driven by controlling the current value supplied to the motor according to the output command value.
[0020]
The control unit 20 serving as the control unit and the correction unit outputs the position command value and the speed command value to the drivers 16 to 19 of the respective linear motors based on the position data and the speed data sequentially read from the memory 22, for example, The linear motor 8 is a specific motor, and the position detection value S ₁ from the linear scale 12 corresponding thereto and the position detection values S ₂ , S ₃ , S ₄ from the linear scales 13 to 15 corresponding to the other linear motors 9 to 11. If a difference occurs between the position command value and the speed command value for the other linear motors 9 to 11 based on the difference, a predetermined arithmetic expression is used to reduce the difference. Take control.
[0021]
Next, the operation of the linear motor press machine having the above configuration will be described. First, the pattern data of the press operation program is written in the memory 22 in advance prior to the operation of the press machine.
[0022]
This pattern data is created from a stroke diagram as shown in FIG. 5, and the stroke diagram is created in an arbitrary shape by taking time on the horizontal axis and the displacement (position) of the slide 4 on the vertical axis. The stroke curve diagram of FIG. 5 shows various patterns when the SPM value (number of strokes per minute) is 100, that is, the time of one stroke is 600 milliseconds, and the stroke length is 30 mm. The stroke length can be arbitrarily determined.
[0023]
From this stroke curve diagram, position data for every unit time (for example, every 10 milliseconds when one stroke is divided into 60) and speed data obtained from the time and displacement until that time are taken, and for each line number, These position data and speed data are created as position command values and speed command values, and program pattern data is completed. Such pattern data, that is, position command values and speed command values for each unit time are stored in the memory. 22 is stored.
[0024]
Next, on the control unit 20 of the press machine, the actual press working operation is set as shown in the flowchart of FIG. That is, the operator first displays a setting screen on the display 23 (step 100) and operates the switches 24 to set and input a stroke pattern number, a stroke length, an SPM value, a die height, and the like (step 110). Then, the CPU 21 of the control unit 20 reads the program pattern data having the designated pattern number from the memory 22, and the data is, for example, an SPM value 100 (the number of strokes per minute is 100, as described above, every 10 milliseconds. If the set SPM value is 80, for example, each speed data is multiplied by a coefficient of 0.8, the speed data is rewritten (step 120), and the setting is completed. To do.
[0025]
Then, when the screen of the display 23 is switched to the operation screen and the operation switch is turned on, the press enters the operation, and as shown in FIG. 7, the CPU 20 sequentially selects each time point from the program pattern data in the memory 22. Each position data and speed data are read (step 200), and a speed command value is output to the drivers 16 to 19 of each linear motor (step 210). The drivers 16 to 19 output, for example, PWM controlled currents to the linear motors 8 to 11 in accordance with the speed command values, so that the magnet plates (movers) 8b to 11b of the linear motors 8 to 11 are operated. Driven, the vertical movement frame 5, the guide post 3, and the slide 4 are controlled so as to descend at the command speed with the position command value of the position data as a target value.
[0026]
The movement distance (movement position) is detected by each of the linear scales 12 to 15, and their position detection signals are sent to the control unit 20, and the CPU 21 detects their position detection values S ₁ , S ₂ , S ₃ , S _4. (Step 220).
[0027]
Next, at step 230, CPU 21 is a position detection value S ₂ of the position detection values S ₁ and another linear scale 13 to 15 of the linear scale 12 corresponding to the linear motor 8 to a predetermined, S _3, and S ₄ comparing, if there is a difference therebetween, the flow proceeds to step 235, the difference as the difference _{S 1 -S 2 = D 2,} S 1 -S 3 = D 3, S 1 -S 4 = D 4 The correction values D ₂ , D ₃ and D ₄ are calculated.
[0028]
Next, in step 240, reads the next position data and velocity data from the pattern data memory 22, the next step 250, corrects the command value of the linear motor 9 to 11 except linear A motor 8 is a specific motor . That is, for the speed command values K ₂ , K ₃ , K ₄ and the position command values R ₂ , R ₃ , R ₄ for the other linear motors 9 to 11, the correction values D ₂ , D ₃ , According to D ₄ , correction is performed using an arithmetic expression such that K ₂ + F · D ₂ = K ₂ , K ₃ + F · D ₃ = K ₃ , and K ₄ + F · D ₄ = K ₄ . Here, F is a coefficient. Further, the position command values R ₂ , R ₃ , and R ₄ are corrected using arithmetic expressions of R ₂ + D ₂ = R ₂ , R ₃ + D ₃ = R ₃ , and R ₄ + D ₄ = R ₄ .
[0029]
Then, the process returns to step 210 again, and the corrected speed command values K ₂ , K ₃ , K ₄ are output to the drivers 17 to 19 of the respective linear motors, and the positions of the linear scales 13 to 15 corresponding to the respective linear motors 9 to 11 are output. The linear motors 9 to 11 are controlled and driven so that the detection signals become the position command values R ₂ , R ₃ and R ₄ . Speed command value is not corrected for linear A motor 8 which is predetermined is outputted to the driver 16, it is driven and controlled. If it is determined in step 230 that the position detection values S ₂ , S ₃ , S _{4 of} the linear scales 13 to 15 corresponding to other motors are the same as the position detection value S ₁ of the linear scale 12 of the specific motor, Returning to step 200 again without performing correction, the next speed data and position data are read, and the linear motors 8 to 11 are driven and controlled in the same manner as described above.
[0030]
As described above, the linear motors 8 to 11 are driven and controlled, whereby the slide 4 and the upper die of the press machine move (up and down) in accordance with a program pattern designated in advance, and press working is performed. At this time, the linear motors 8 to 11 are driven and controlled so that the position detection values from the linear scales 12 to 15 corresponding to the respective motors are the same, so that an eccentric load is applied to the slide 4 during press working. Even in such a case, it is possible to prevent the slide 4 from inclining and to perform good pressing.
[0031]
In the above embodiment, four linear motors are used. However, two or more linear motors can be used. Further, the linear scale as the position detector can use another encoder or the like.
[Brief description of the drawings]
FIG. 1 is a perspective view of a press machine showing an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the press.
FIG. 3 is a plan view of the press.
FIG. 4 is a block diagram of a control unit including a linear motor and a linear scale.
FIG. 5 is a process curve diagram of a program pattern for press working.
FIG. 6 is a flowchart showing a setting operation.
7 is a driving control process shown to the flowchart.
[Explanation of symbols]
1-body frame 4-slides 8-11-linear motors 12-15-linear scale 20-control unit 21-CPU
22-memory

Claims (1)

In a control device of a linear motor press machine in which a slide is disposed so as to be capable of reciprocating with respect to a main body frame, and a plurality of linear motors are mounted in the direction of movement of the slide to reciprocate the slide.
A moving frame is disposed in the main body frame so as to be able to reciprocate together with a plurality of guide posts, and the slide is fixed on the guide posts, corresponding to each linear motor near the fixed position of the guide posts on the slide. A plurality of linear scales are mounted between the main body frame and the guide post between the main body frame and the moving frame so as to detect the moving position of the slide and output a position detection signal. Each of the plurality of linear motors is arranged in the vicinity,
Pattern data storage means for sequentially storing position data and speed data created per unit time based on a stroke curve diagram when the slide moves;
During operation, position data and speed data are sequentially read from the pattern data storage means, and a control means for driving and controlling the linear motor at a speed indicated by the speed data with a position indicated by the position data as a target position;
Calculating a difference between the position detection data from the position detection data and other Riniasuke Le from advance one said linear scale of which is determined, said linear motor corresponding to the another linear scale based on the difference Correction means for correcting so as to reduce the difference between the position data and the speed data;
A control apparatus for a linear motor press machine.

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