JP2022039221A - Hydraulic press, control device for hydraulic press and program - Google Patents

Abstract

To provide a hydraulic press capable of performing molding with high accuracy, a control device and a program.SOLUTION: A hydraulic press includes a first slide (12A) for applying a load to a work-piece, a first hydraulic circuit (13A) for driving the first slide, a first hydraulic pump (21A) for applying hydraulic pressure to the first hydraulic circuit, a first position sensor (18A) for detecting the position of the first slide, a position calculation part (31) for calculating a target position in each time of the first slide corresponding to a target movement condition on the basis of the target movement condition of the first slide, and a control part (32) for controlling a drive amount of the first hydraulic pump (21A) on the basis of difference between a detection position (PV) of the first slide detected by the first position sensor and a target position (SV) in each time of the first slide.SELECTED DRAWING: Figure 2

Description

The present invention relates to a hydraulic press, a control device and a program for the hydraulic press.

Patent Document 1 describes a mechanical servo press that moves a slide to the bottom dead center with high accuracy. In a mechanical servo press, the power of the servo motor is transmitted to the slide via a link mechanism.

Japanese Unexamined Patent Publication No. 2000-176699

In recent years, hydraulic presses that control the position, speed, load, etc. of a slide by controlling the drive amount of a hydraulic pump with a servomotor have been put into practical use. By using hydraulic pressure, it is possible to obtain a large slide load at low cost. On the other hand, the responsiveness of the action of pumping the hydraulic oil by the hydraulic pump is not high, and in addition, the hydraulic oil has compressibility. Therefore, in the hydraulic press that controls the drive amount of the hydraulic pump, there is a problem that it is difficult to obtain the position accuracy of the slide as compared with the mechanical servo press.

An object of the present invention is to provide a hydraulic press, a control device for the hydraulic press, and a program capable of performing molding with high accuracy.

The hydraulic press according to the present invention is
The first slide that applies a load to the work, and
The first hydraulic circuit that drives the first slide and
A first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit,
The first position sensor that detects the position of the first slide and
Based on the target movement condition of the first slide, a position calculation unit that calculates the target position for each time of the first slide corresponding to the target movement condition, and
A control unit that controls the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
To prepare for.

The hydraulic press control device according to the present invention is
The first slide that applies a load to the work, the first hydraulic circuit that drives the first slide, the first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit, and the first position that detects the position of the first slide. A hydraulic press control device mounted on a hydraulic press equipped with a sensor.
Based on the target movement condition of the first slide, a position calculation unit that calculates the target position for each time of the first slide corresponding to the target movement condition, and
A control unit that controls the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
To prepare for.

The program according to the present invention
The first slide that applies a load to the work, the first hydraulic circuit that drives the first slide, the first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit, and the first position that detects the position of the first slide. A program executed by a computer mounted on a hydraulic press equipped with a sensor.
To the computer
Based on the target movement condition of the first slide, a calculation function for calculating the target position for each time of the first slide corresponding to the target movement condition, and
A control function for controlling the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
To realize.

According to the present invention, high-precision molding can be performed in a hydraulic press.

It is a figure which shows the hydraulic press which concerns on Embodiment 1 of this invention. It is a figure which shows the control structure of the hydraulic press which concerns on Embodiment 1 of this invention. It is a timing chart which shows an example of the target position for each time of a slide calculated by a position calculation unit. It is a timing chart which expanded the speed change section C1 of FIG. It is a figure explaining the strain rate of a work. It is a block diagram which shows an example of the arithmetic function composition included in a control part. It is a figure which shows the hydraulic press which concerns on Embodiment 2 of this invention. It is a figure which shows the control structure of the hydraulic press which concerns on Embodiment 2 of this invention. It is a figure explaining the operation of the 2nd slide, (A) shows the work in the middle of molding and the mold, (B) shows the work after molding.

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a hydraulic press according to the first embodiment of the present invention. FIG. 2 is a diagram showing a control configuration of a hydraulic press according to the first embodiment of the present invention. Hereinafter, the direction in which the load is applied to the slide 12A will be described as downward. It should be noted that the explanatory direction does not have to coincide with the direction when the hydraulic press 1A is used.

As shown in FIG. 1, the hydraulic press 1A of the first embodiment has a bed 11 that supports the lower mold D2, a slide 12A that supports the upper mold D1, and a hydraulic cylinder that lowers the slide 12A by the pressure of hydraulic oil. The hydraulic circuit 13A including the above, a hydraulic pump 21A for applying pressure to the hydraulic oil, a servo motor 23A for driving the hydraulic pump 21A, and a position sensor 18A for detecting the descending position of the slide 12A are provided. The hydraulic press 1A further includes a crown 16 that supports the hydraulic circuit 13A, and an upright 14 and a tie rod 15 that connect the crown 16 and the bed 11. The slide 12A is guided to the upright 14 so as to be able to move up and down. The position sensor 18A is, for example, a linear sensor and is fixed to the upright 14. Of the above components, slide 12A corresponds to an example of the first slide according to the present invention. The hydraulic circuit 13A corresponds to an example of the first hydraulic circuit according to the present invention. The hydraulic pump 21A corresponds to an example of the first hydraulic pump according to the present invention. The position sensor 18A corresponds to an example of the first position sensor according to the present invention.

The hydraulic press 1A further receives the detection output of the position sensor 18A and outputs a signal of the operation amount MV for driving the hydraulic pump 21A, and responds to the signal of the operation amount MV from the control device 30. A drive circuit 41 for driving the hydraulic pump 21A is provided. The drive of the hydraulic pump 21A may be paraphrased as the drive of the servo motor 23A. The control device 30 is a computer, and is a CPU (Central Processing Unit) 30A, a storage device 30B storing a program P30 executed by the CPU, an interface 30C that mediates a signal between the CPU 30A and an external device, a touch panel, and the like. It is provided with a user interface 30D for inputting / outputting information to / from the user. In the control device 30, the CPU 30A executes the program P30 to realize a plurality of functional modules by software. The control device 30 can be retrofitted to the main body of the hydraulic press 1A.

As shown in FIG. 2, the plurality of functional modules realized by the control device 30 include an input function unit 33 for inputting a target movement condition of the slide 12A by a user operation, and a slide based on the input target movement condition. The hydraulic pump 21A is based on the difference between the position calculation unit 31 that calculates the target position SV for each time of 12A, the detection position PV of the slide 12A detected by the position sensor 18A, and the calculated target position SV for each time. A control unit 32 for calculating the operation amount MV is provided. The target movement condition is not configured to be input by the user, but may be configured to be possessed by the control device 30 in advance.

FIG. 3 is a timing chart showing an example of the target position for each time of the slide. FIG. 4 is an enlarged timing chart of the speed change section C1 of FIG. FIG. 5 is a diagram illustrating a strain rate of the work. Here, FIGS. 3 and 4 will be described as a timing chart showing the actual moving position of the slide 12A. In FIGS. 3 and 4, the pressurization start position of the slide 12A at which the upper die D1 starts to apply a load to the work is referred to as “Ps”, and the pressurization end position where the slide 12A drops most in the work forming process is referred to as “Pe”. ..

The target movement conditions of the slide 12A input from the input function unit 33 can include various conditions such as the target movement conditions of the following first to fifth examples.
1st example: 1 target movement speed and 1 target arrival position 2nd example: 1st target movement speed, 1st target arrival position, 2nd target movement speed, and 2nd target arrival position 3rd example: 1st to nth (n is an integer of 3 or more) target moving speed, and 1st to nth target arrival position 4th example: In addition to the 1st to 3rd examples 5th example of the division parameter of the speed change section ... Target strain rate of the work

In the target movement condition of the first example, the target movement speed is, as shown in FIG. 3, the descent of the slide 12A from the pressurization start position Ps (or a position above it) to the vicinity of the pressurization end position Pe. It means the target value of the speed V1. Further, the target arrival position means the target value of the pressurization end position Pe.

In the target movement condition of the second example, the first target movement speed and the first target arrival position are the target values of the descending speed of the slide 12A to an arbitrary intermediate position between the pressurization start position Ps and the pressurization end position Pe. And the target value at the intermediate position, respectively. Further, the second target moving speed and the second target reaching position mean the target value of the descending speed of the slide 12A from the intermediate position to the vicinity of the pressurization end position Pe and the target value of the pressurization end position Pe. do. In other words, the target movement condition of the second example specifies the target value of the descending speed of the slide 12A in two sections obtained by dividing the area from the pressurization start position Ps to the vicinity of the pressurization end position Pe into two at arbitrary positions. It is a target movement condition.

As for the target movement condition of the third example, while the second example was able to specify the target value of the descending speed of the slide 12A in the two sections, any plurality of objects from the pressurization start position Ps to the pressurization end position Pe could be specified. It is a target movement condition for designating the target value of the descending speed of the slide 12A of each divided section divided into three or more at the position.

In the target movement condition of the fourth example, the deflection parameter means the target value of the parameter indicating the speed change of the slide 12A. As shown in FIG. 4, the descending speed of the slide 12A is set to gradually decrease in the speed changing section C1, and the speed of the descending speed can be changed by the deflection parameter. The eccentricity parameter may include a target value at the position where the velocity begins to decrease.

In the target movement condition of the fifth example, the target strain rate indicates a target value of the strain rate ε'= V / (Ly) = V / z of the work W (see FIG. 5). Here, V is the descending speed of the slide 12A (that is, the descending speed of the upper mold D1), L is the vertical dimension of the work W before molding, y is the amount of decrease in the vertical dimension of the work W during molding, and z is during molding. It is the vertical dimension of the work W of. FIG. 5 shows an example in which the work W is deformed by receiving a load between the upper mold D1 supported by the slide 12A and the lower mold D2 supported by the bed 11. Step J1 shows before deformation, and step J2 shows during deformation. When the strain rate is constant, the descending speed V of the slide 12A is determined as V = ε'(Ly) = ε'xz based on the strain rate ε'. That is, the descending speed V decreases as the position of the slide 12A becomes lower. In the target movement condition of the fifth example, one target value may be specified for the target strain rate in the entire section from the pressurization start position Ps to the pressurization end position Pe, or the second example and the second example. As in the target movement conditions of the three examples, the target value may be specified in any one or a plurality of sections among the sections divided into a plurality of sections from the pressurization start position Ps to the pressurization end position Pe. Further, among the plurality of sections, a target movement speed may be specified for any section, and a target strain rate may be specified for any other section.

The input function unit 33 may be configured so that the user can input the target movement condition via the user interface 30D such as a touch panel, or can read a portable storage device (memory card or the like) in which the target movement condition is written. The input method is not particularly limited, for example, the target movement condition may be input in. The input function unit 33 may hold a plurality of patterns of target movement conditions in advance, and the user may select one of the target movement conditions to input the selected target movement conditions.

The position calculation unit 31 calculates the target position of the slide 12A for each time corresponding to the target movement condition based on the target movement condition input from the input function unit 33. For example, when the target movement condition (target movement speed and target arrival position) of the first example is input from the input function unit 33, the position calculation unit 31 performs slide 12A as shown in the time charts of FIGS. 3 and 4. Calculate the target position for each hour. The target moving speed corresponds to the speed V1 of the time chart, and the target reaching position corresponds to the pressurization end position Pe. If the input target movement condition does not include the deflection parameter of the fourth example, the position calculation unit 31 performs the default deflection as shown by the chart line of the default deflection parameter “1.0”. Calculate the target position for each added time. Further, when the input target movement condition includes the deflection parameter of the fourth example, the position calculation is performed as shown in the chart line corresponding to the input deflection parameter among the plurality of chart lines in FIG. The unit 31 calculates the target position for each time with the specified deflection added.

Further, when the target movement condition (target strain rate of the work) of the fifth example is input from the input function unit 33, the position calculation unit 31 determines the slide 12A so that the strain rate of the work becomes the target strain rate. Calculate the target position for each hour. In the case of the work W and the mold (D1 and D2) as shown in FIG. 5, the position calculation unit 31 increases the decrease amount y in the vertical dimension of the work W in FIG. 5, that is, the lowering amount y of the slide 12A. The target position for each time when the descending speed V of the slide 12A decreases in proportion to the vertical dimension z of the work W being formed is calculated.

As described above, the position calculation unit 31 calculates the target position of the slide 12A for each time corresponding to the target movement condition, but "corresponding to the target movement condition" means that the target movement condition is strictly satisfied. Not limited. "Corresponding to the target movement condition" is a concept including a thing that almost satisfies the target movement condition after a predetermined correction is applied, for example, a speed division is added in a speed change section. The position calculation unit 31 may calculate the target position for each time of the entire section in advance and hold the calculation result before the molding step in which the slide 12A actually moves, or the slide 12A during the molding step. The target position of slide 12A at one or more control cycle destinations may be calculated in parallel with the movement of. The control cycle means the cycle period of the position control process of the slide 12A by the control unit 32.

FIG. 6 is a diagram showing an example of a calculation function configuration included in the control unit.

The control unit 32 has a detection position PV and a target position of each control cycle based on the detection position PV of the slide 12A sent from the position sensor 18A and the time-wise target position SV of the slide 12A calculated by the position calculation unit 31. Feedback control is performed so that the difference from the SV becomes small. Alternatively, both fordback control and feedforward control are performed. Then, as a result of the above control, the control unit 32 calculates the operation amount MV for driving and controlling the hydraulic pump 21A. The control unit 32 repeatedly executes the above control and calculation in real time every predetermined control cycle (for example, 1 msec).

More specifically, as shown in FIG. 6, the control unit 32 includes a subtractor 321, a transmission block 322, 323, an adder 324, a gain block 325, and an integrator 326. The subtractor 321 calculates the difference EV _n between the detection position PV _n of the slide 12A of the current control cycle input from the position sensor 18A and the target position SV _n of the current control cycle calculated by the position calculation unit 31. The transfer block 322 applies the transfer function "1 + 1 / (Ti · s)" to the difference EV _n and outputs the value after application. The transfer block 323 applies the transfer function "Td · s / (1 + Td · Kd · s)" to the detection position PV _n , and outputs the value after application. The adder 324 adds the outputs of the transmission blocks 322 and 323. The gain block 325 exerts a proportional gain Kp on the output of the adder 324 and outputs the manipulated variable difference ΔMV from the previous control cycle. The integrator 326 integrates the operation amount difference ΔMV and outputs the operation amount MV for driving and controlling the hydraulic pump 21A. Here, Ti is the integration time, Td is the differential time, Kd is the differential gain, s is the Laplace operator, and the subscript n is the nth control cycle. With the calculation function configuration as described above, the operation amount MV for quickly reducing the difference EV _n is calculated by PID (Proportional-Integral-Differential) control. The control unit 32 repeats the above calculation process in real time and every predetermined control cycle.

As a result of the calculation process of the control unit 32 as described above, the operation amount MV is sent to the drive circuit 41 for each control cycle, and the drive circuit 41 drives the hydraulic pump 21A according to the input operation amount MV. Specifically, the drive circuit 41 drives the servomotor 23A so that the operation amount MV matches the rotation speed of the servomotor 23A. By such drive control, the slide 12A moves so that the position at each time point matches the target position SV for each time calculated by the position calculation unit 31, and the slide 12A moves according to the target movement condition input by the user. Is realized.

As shown in FIG. 2, the control unit 32 may input the value of the stop position of the slide 12A (for example, the target arrival position of the target movement condition of the first example) from the input function unit 33. In this case, the control unit 32 may perform a stop determination of the slide 12A when the position of the slide 12A moves to the stop position, and shift to a process of stopping the movement control of the slide 12A.

Here, as a comparative example, a speed control method for moving the slide so that the descending speed of the slide matches the target speed will be examined. In the speed control method, for example, if a speed shift occurs at the initial stage of descent of the slide, even if the speed shift is eliminated by the subsequent speed control, the slide position shift based on the speed shift (with the planned position at a certain timing). The deviation from the actual position) remains unresolved. In order to eliminate such a positional deviation, it is necessary to control the slide speed to increase or decrease, but in the speed control method, the control works to match the slide speed with the target speed, so the position as described above. The speed cannot be increased or decreased to eliminate the deviation.

On the other hand, according to the drive control of the slide 12A of the present embodiment, the slide 12A moves so as to follow the target position SV for each time. Therefore, for example, even if the position of the slide 12A is displaced at the initial stage of descending the slide 12A, the descending speed of the slide 12A is increased or decreased thereafter, and the displacement of the slide 12A is eliminated. Therefore, it is possible to prevent the misalignment of the slide 12A at the initial stage of descent from being eliminated and remaining continuously during the subsequent movement of the slide 12A. Therefore, according to the control of the present embodiment, the movement of the slide 12A is less likely to be disturbed, and the movement of the slide 12A can be realized with high accuracy. Therefore, a highly accurate molding process can be realized.

Further, in the above-mentioned comparative example (speed control method), when the slide is moved in the low speed region in the vicinity of the pressurization end position Pe, there arises a problem that the resolution of the slide speed control in the low speed region is insufficient. For example, the moving speed of the slide is calculated by the change ΔY of the position of the slide during the calculation period ΔT. Assuming that the calculation cycle is 1 [msec] and the resolution of the slide position (minimum unit of the position sensor) is 1 [μm], the resolution of the calculated velocity ΔY / ΔT is 1 [mm / sec]. In this case, speed control of less than 1 [mm / sec] cannot be performed, and even if speed control of several [mm / sec] is performed, the ratio of deviation to the target speed becomes large, and the speed is highly accurate due to feedback control. It becomes difficult to control. The problem of reduced accuracy due to such insufficient resolution also arises when it is desired to control the strain rate of the work in the low speed range.

On the other hand, in the case of the drive control of the slide 12A of the first embodiment, if the resolution of the position of the slide 12A is 1 [μm], the position of the slide 12A can be controlled by the resolution. Therefore, even if the speed of the slide 12A is in the low speed range, the slide 12A can be moved with high accuracy. Therefore, control such as moving the slide 12A in the vicinity of the pressurization end position Pe in a low speed range to reach the pressurization end position Pe can be stably executed with high accuracy, whereby a highly accurate molding process can be performed. Can be realized. Further, even when the strain rate of the work is controlled, high-precision control in a low speed range becomes possible for the same reason.

As described above, according to the hydraulic press 1A of the first embodiment, the position calculation unit 31 calculates the target position SV for each time of the slide 12A based on the target movement condition, and the control unit 32 calculates the target position SV and the slide 12A. The drive amount of the hydraulic pump 21A is controlled based on the difference from the detection position PV of. Therefore, as described above, the slide 12A can be moved with high accuracy as compared with the speed control method for adjusting the speed of the slide 12A to the target value, whereby high quality molding processing can be realized. Further, if the target movement condition is specified, the position calculation unit 31 calculates the target position SV for each time of the slide 12A corresponding to the target movement condition, so that the complexity of inputting the control data for moving the slide 12A is reduced. can.

Further, according to the hydraulic press 1A of the first embodiment, when the target moving speed and the target reaching position of the slide 12A are specified as the target moving conditions, the position calculation unit 31 moves the slide 12A at the target moving speed. The hourly target position of the slide 12A is calculated so as to gradually decrease (gradually decrease) the descending speed and move to the target arrival position. Therefore, by inputting a small amount of control data (target movement speed and target arrival position), the slide 12A descends at a constant speed, and movement to stably reach the target arrival position can be realized.

In the press process, the moving speed of the slide 12A when the work is deformed by applying a load and the lowering end position (pressurization end position Pe) of the slide 12A at which the deformation of the work ends are the moving conditions of the slide 12A. Often specified from. If there is no ingenuity for such a movement condition, the speed of the slide 12A is controlled by the speed control method according to the designation of the movement speed, and then the control method is changed to the position control method, and the descent end position is changed. It is assumed that a control method such as controlling the stop position of the slide 12A is adopted according to the designation of. However, in the control method of switching from the speed control method to the position control method on the way in this way, the control is liable to be disturbed when the control method is switched. On the other hand, according to the hydraulic press 1A of the first embodiment, even when both the speed (speed from the initial processing to the end of processing) and the position (processing end position) of the slide 12A are specified, the speed is increased. The designation is converted into a target position designation for each hour, so that both the speed designation and the position designation are achieved by the position control of the slide 12A. Therefore, the control method does not switch from the speed control to the position control in the middle, and high-precision control with less disturbance from the start to the end of molding becomes possible.

Further, according to the hydraulic press 1A of the first embodiment, when the target strain rate of the work is specified as the target movement condition, the position calculation unit 31 determines the time of the slide 12A so that the strain rate of the work becomes the target strain rate. Calculate the target position for each. Then, by controlling the drive of the slide 12A according to the target position, it is possible to realize a molding process in which the strain rate of the work is controlled with high accuracy. Further, according to the above configuration, it is possible to realize a molding process in which the strain rate of the work is specified by inputting a simple target movement condition.

(Embodiment 2)
FIG. 7 is a diagram showing a hydraulic press according to the second embodiment of the present invention. FIG. 8 is a diagram showing a control configuration of the hydraulic press of the second embodiment. 9A and 9B are views for explaining the operation of the second slide, where FIG. 9A shows a work in the middle of molding and a mold, and FIG. 9B shows a work after molding.

The hydraulic press 1B of the second embodiment includes a second slide 12B, a second hydraulic circuit 13B having a piston cylinder, a second hydraulic pump 21B, and a second hydraulic pump 21B in addition to the components of the hydraulic press 1A of the first embodiment. It includes a second servomotor 23B to be driven and a second position sensor 18B such as a linear sensor. The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The components corresponding to the slide 12A, the hydraulic circuit 13A, the hydraulic pump 21A, the servomotor 23A and the position sensor 18A of the first embodiment are the first slide 12A, the first hydraulic circuit 13A, the first hydraulic pump 21A, and the first servomotor. It is referred to as 23A and the first position sensor 18A.

In the hydraulic press 1B of the second embodiment, the hydraulic oil pressurized by the first hydraulic pump 21A is supplied to the first hydraulic circuit 13A, whereby the first slide 12A is lowered and the first position sensor 18A is the first. The position of the slide 12A is detected. On the other hand, the hydraulic oil pressurized by the second hydraulic pump 21B is supplied to the second hydraulic circuit 13B including the piston cylinder, whereby the second slide 12B rises and the second position sensor 18B moves to the second slide 12B. Detect the position.

The second slide 12B and the second hydraulic circuit 13B are arranged in the bed 11, for example, and as shown in FIG. 9A, the lower punch D13, which is a part of the lower mold D12, is raised to the work W. A separate load is applied. That is, the tip portion of the lower punch D13 can be moved forward and backward in the cavity formed between the upper mold D11 and the lower mold D12. The arrangement and operation of the second slide 12B and the second hydraulic circuit 13B are not limited to the above example, and for example, the second slide 12B and the second hydraulic circuit 13B separately move a part of the upper mold D11. It may be configured, or it may be configured to move the entire lower mold D12 up and down.

In the control device 30, the CPU 30A executes the program P30 to realize a plurality of functional modules by software. As shown in FIG. 8, the plurality of functional modules have the input function unit 33B into which the target movement condition of the first slide 12A and the target movement condition of the second slide 12B are input, and the target movement condition of the first slide 12A. Based on this, the first position calculation unit 31 that calculates the target position SVa of the first slide 12A for each time, the detection position PVa of the first slide 12A detected by the first position sensor 18A, and the above-calculated target for each time. A first control unit 32 that calculates an operation amount MVa for driving and controlling the first hydraulic pump 21A based on the difference from the position SVa is included. The same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

Further, the plurality of functional modules are detected by the second position calculation unit 36 that calculates the target position SVb for each time of the second slide 12B based on the target movement condition of the second slide 12B, and the second position sensor 18B. The second control unit 37 calculates the operation amount MVb for driving and controlling the second hydraulic pump 21B based on the difference between the detected position PVb of the second slide 12B and the calculated target position SVb for each time. included. The operation amount MVb is sent to the drive circuit 42 of the second servomotor 23B, and the drive circuit 42 drives the second servomotor 23B at a rotation speed corresponding to the operation amount MVb. Among the above components, the first position calculation unit 31 and the second position calculation unit 36 correspond to an example of the position calculation unit according to the present invention. The first control unit 32 and the second control unit 37 correspond to an example of the control unit according to the present invention.

The target movement condition of the first slide 12A is input to the input function unit 33B in the same manner as the input function unit 33 of the first embodiment. Further, the target movement condition of the second slide 12B is input to the input function unit 33B in the same manner as the target movement condition of the first slide 12A. Further, a synchronization condition indicating how the target movement condition of the first slide 12A and the target movement condition of the second slide 12B are synchronized is input to the input function unit 33B. The synchronization condition indicates, for example, a condition that the timing at which the second slide 12B moves and the timing at which the first slide 12A moves are synchronized. The target movement conditions and synchronization conditions of the first slide 12A and the second slide 12B are input by the user, for example, via the user interface 30D.

The second position calculation unit 36 calculates the target position for each time of the second slide 12B corresponding to the target movement condition of the second slide 12B, similarly to the first position calculation unit 31. However, when the target strain rate of the work is included in the target movement condition, the strain rate of the work when the movement of the first slide 12A and the movement of the second slide 12B are combined matches the target strain rate. In addition, the target position for each time of the second slide 12B is calculated according to the target position for each time of the first slide 12A.

The second control unit 37 has the detection position PVb of the second slide 12B sent from the second position sensor 18B and the second position calculation unit 36 in the same manner as the process performed by the first control unit 32 for the first slide 12A. The target position SVb of the second slide 12B calculated by is input. Then, the second control unit 37 controls the drive amount of the second hydraulic pump 21B by performing feedback control or both feedback control and feedforward control so that the difference between the detection position PVb and the target position SVb becomes small. do. The second control unit 37 repeats the above control process in real time and in synchronization with the control process of the first control unit 32 at predetermined control cycles.

The hourly target position of the first slide 12A calculated by the first position calculation unit 31 and the second position calculation unit 36 and the hourly target position of the second slide 12B are input via the input function unit 33B. It is calculated to meet the synchronized synchronization conditions. Therefore, the first control unit 32 and the second control unit 37 synchronize the control timing and execute the above control process in the same control cycle, thereby corresponding to each target movement condition and the synchronization condition. The movement of the first slide 12A and the second slide 12B satisfying the above conditions is realized.

As an example of the detailed calculation function of the second control unit 37, the same configuration as the detailed calculation function of the first control unit 32 shown in FIG. 6 can be applied.

As shown in FIG. 8, the input function unit 33B may input the value of the stop position of the second slide 12B to the second control unit 37. In this case, the second control unit 37 determines the stop of the second slide 12B when the position of the second slide 12B moves to the stop position, and shifts to the process of stopping the movement control of the second slide 12B. May be good.

According to the hydraulic press 1B of the second embodiment, the target position of the first slide 12A and the second slide 12B for each time is calculated based on the target movement condition of the first slide 12A and the target movement condition of the second slide 12B. Ru. Then, the positions of the first slide 12A and the second slide 12B are controlled so that the detected position coincides with the target position for each time. Therefore, as shown in FIG. 9A, the forming of the work W ends from the pressurizing start position where the upper mold D11 and the lower mold D12 apply a load to the work W and the work W starts to deform. The upper mold D11 moves to the pressurization end position with high accuracy so as to meet the target movement condition. Similarly, the lower punch D13 moves with high accuracy so as to meet the target movement condition until the lower punch D13 applies a load to the work W and rises to the pressurization end position. Further, since the position control of the first slide 12A and the position control of the second slide 12B are performed in synchronization, the mutual positional relationship between the upper mold D11 and the lower punch D13 is shown by the respective target movement conditions. Matches the positional relationship with high accuracy.

In the molding of the work W as shown in FIG. 9, it may be required that the flow of the material of each part of the work W when the work W is deformed becomes the target flow. In this case, it becomes necessary to control the mutual positional relationship between the upper die D11 and the lower punch D13 so that the target material flow can be obtained. According to the hydraulic press 1B of the second embodiment, the above-mentioned request can be met by the position control of the first slide 12A and the second slide 12B described above.

As described above, according to the hydraulic press 1B of the second embodiment, the high-precision movement of the first slide 12A and the high-precision movement in the low speed range are realized as in the hydraulic press 1A of the first embodiment. Further, according to the hydraulic press 1B of the second embodiment, since the same movement control as that of the first slide 12A is performed for the second slide 12B, the movement of the second slide 12B is also performed with high accuracy. , Highly accurate movement in the low speed range is realized. Further, since the movement of the first slide 12A and the second slide 12B is performed by the position control, the movement position of the first slide 12A and the movement position of the second slide 12B must be aligned at any timing. After that, the movement of the first slide 12A and the movement of the second slide 12B are less likely to be out of sync. Therefore, a pressing operation in which the correlation positions of the first slide 12A and the second slide 12B are controlled with high accuracy can be obtained. Therefore, high quality press molding can be realized.

Further, also in the hydraulic press 1B of the second embodiment, when the target moving speed and the target reaching position of the second slide 12B are specified as the target moving conditions, the second position calculation unit 36 moves the second slide 12B to the target. The hourly target position of the second slide 12B is calculated so as to increase at a speed and gradually decrease (gradually decrease) the ascending speed to move to the target arrival position. Therefore, by inputting a small amount of control data (target movement speed and target arrival position), it is possible to realize a movement that stably reaches the target arrival position after the second slide 12B rises at a constant speed.

Further, according to the hydraulic press 1B of the second embodiment, when the target strain rate of the work is specified as the target movement condition, the strain rate of the work is the target strain of the first position calculation unit 31 and the second position calculation unit 36. The target positions of the first slide 12A and the second slide 12B for each time are calculated so as to be the speed. Then, by performing drive control of the first slide 12A and the second slide 12B according to the target position, it is possible to realize a molding process in which the strain rate of the work is controlled with high accuracy. Further, according to the above configuration, it is possible to realize a molding process in which the strain rate of the work is specified by inputting a simple target movement condition.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the configuration for controlling the drive amount of the hydraulic pump is shown by software, but these may be configured by hardware. Further, although an example in which a servomotor is applied as a motor for driving the hydraulic pump 21A, the first hydraulic pump 21A, and the second hydraulic pump 21B is shown, a motor other than the servomotor such as a motor whose driving force can be variably controlled is applied. May be done. Further, in the above embodiment, the control device 30 is provided with the functions of the control unit 32, the position calculation unit 31, the first control unit 32, the first position calculation unit 31, the second control unit 37, and the second position calculation unit 36. An example is shown in which the program (P30) to be realized is stored in the storage device 30B of the control device 30. However, the above program may be stored in a portable recording medium such as an optical disk or an IC (Integrated Circuit) memory, and a configuration may be adopted in which the program is read by a control device (computer) 30 and executed. In addition, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

1A, 1B Hydraulic press 12A slide, 1st slide 12B 2nd slide 13A Hydraulic circuit, 1st hydraulic circuit 13B 2nd hydraulic circuit 18A Position sensor, 1st position sensor 18B 2nd position sensor 21A Hydraulic pump, 1st hydraulic pump 21B 2nd hydraulic pump 23A Servo motor, 1st servo motor 23B 2nd servo motor 30 Control device P30 Program 31 Position calculation unit, 1st position calculation unit 32 Control unit, 1st control unit 33, 33B Input function unit 36 2nd position Calculation unit 37 Second control unit SV, SVa, SVb Target position for each time PV, PVa, PVb Detection position MV, MVa, MVb Operation amount D1, D11 Upper mold D2, D12 Lower mold D13 Lower punch W work

Claims (8)

The first slide that applies a load to the work, and
The first hydraulic circuit that drives the first slide and
A first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit,
The first position sensor that detects the position of the first slide and
Based on the target movement condition of the first slide, a position calculation unit that calculates the target position for each time of the first slide corresponding to the target movement condition, and
A control unit that controls the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
A hydraulic press equipped with. The target movement condition of the first slide includes the target movement speed of the first slide and the target arrival position of the first slide.
The position calculation unit gradually decreases the speed of the first slide from the target movement speed of the first slide, and moves the first slide to the target arrival position for each time of the first slide. Calculate the target position,
The hydraulic press according to claim 1. The target movement condition of the first slide includes the target strain rate of the work.
The position calculation unit calculates the target position of the first slide for each time so that the speed at which the first slide pressurizes the work becomes the target strain rate.
The hydraulic press according to claim 1 or 2. The second slide that applies a load to the work, and
The second hydraulic circuit that drives the second slide and
A second hydraulic pump that applies hydraulic pressure to the second hydraulic circuit,
A second position sensor that detects the position of the second slide, and
Equipped with
The position calculation unit further calculates the target position for each time of the second slide based on the target movement condition of the second slide.
The control unit further determines the driving amount of the second hydraulic pump based on the difference between the detection position of the second slide detected by the second position sensor and the target position of the second slide for each time. Control,
The hydraulic press according to any one of claims 1 to 3. The target movement condition of the second slide includes the target movement speed of the second slide and the target arrival position of the second slide.
The position calculation unit gradually decreases the speed of the second slide from the target moving speed of the second slide and moves to the target reaching position of the second slide for each time of the second slide. Calculate the target position,
The hydraulic press according to claim 4. The target movement conditions of the first slide and the second slide include the target strain rate of the work.
The position calculation unit has a target position for each time of the first slide and each time of the second slide so that the speed at which the first slide and the second slide pressurize the work becomes the target strain rate. Calculate with the target position of
The hydraulic press according to claim 4 or 5. The first slide that applies a load to the work, the first hydraulic circuit that drives the first slide, the first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit, and the first position that detects the position of the first slide. A hydraulic press control device mounted on a hydraulic press equipped with a sensor.
Based on the target movement condition of the first slide, a position calculation unit that calculates the target position for each time of the first slide corresponding to the target movement condition, and
A control unit that controls the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
Hydraulic press control device. The first slide that applies a load to the work, the first hydraulic circuit that drives the first slide, the first hydraulic pump that applies hydraulic pressure to the first hydraulic circuit, and the first position that detects the position of the first slide. A program executed by a computer mounted on a hydraulic press equipped with a sensor.
To the computer
Based on the target movement condition of the first slide, a calculation function for calculating the target position for each time of the first slide corresponding to the target movement condition, and
A control function for controlling the drive amount of the first hydraulic pump based on the difference between the detection position of the first slide detected by the first position sensor and the target position of the first slide for each time.
A program that realizes.

Images