JP2006346742A - Press forming apparatus and method for controlling it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a press forming apparatus and a control method of it by which friction which is generated between a blank material and a die is reduced and a desired formed article is obtained. <P>SOLUTION: This press forming apparatus is provided with a sensor group by which the deformation of a prescribed portion of a blank material is measured at real time in press forming, a part for imparting blank holding force, a part for imparting displacement to a punch, a determination part for determining whether the state of the generation of wrinkles is good or not (a case where the wrinkles are not generated is good and the other case is no-good) on the basis of the data of measured values by the sensor group and a control part for controlling a means for imparting the blank holding force and a means for imparting the displacement to the punch so that forming is progressed by sufficiently reducing the blank holding force loaded on the blank material and also lowering a punch when the result of the determination of the generated state of the wrinkles is good and, otherwise, the generated wrinkles are eliminated by loading sufficient blank holding force after sufficiently lowering the punching speed and, after that, the forming stage is progressed by lowering the punch again. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a press apparatus capable of controlling wrinkle restraining force and press motion in a thin plate press forming apparatus, and a control method for the wrinkle restraining force and press motion.

  In press working, improving the friction between the blank and the tool is indispensable for improving formability. Therefore, while lubricant is one of the most important factors governing moldability, water and organic solvents are used to remove the lubricant after molding, and environmental pollution is a serious problem as industrial waste. It has become. From such a background, the realization of non-lubricating processing is required especially in the press forming of plate material, but the friction state between the blank material and the tool deteriorates with no lubrication, and the inflow of the blank material into the die is caused. It becomes the main factor to prevent. For this reason, the deterioration of the lubrication state has a problem of causing a reduction in moldability.

  In the conventional technique, there is a press forming technique in which frictional force is reduced by using ultrasonic vibration, but high cost is required to introduce the ultrasonic vibration adding device. For this reason, it is difficult to apply to various shapes and moldings for large parts.

  As another conventional technique, there is a technique in which a special coating having excellent lubricity such as a DLC film is applied to the die surface to achieve no lubrication. However, the coating is expensive, and there are many technical problems to be solved for application to the molding of various shapes and large parts. Further, depending on the type of blank material, there may be a problem in the durability of the coating.

  In addition, a technique for reducing the apparent frictional force by adding low-frequency vibration to the wrinkle restraining force has been developed, but there are many technical problems in application to non-lubrication.

  One of the molding conditions that influences press formability is the ability to suppress wrinkles, but these are conventionally determined by trial and error based on the experience and intuition of skilled engineers, and process design takes a lot of time. Was. In particular, the above points are problematic in non-axisymmetric press-molded products such as automobile body panel parts.

  In the microforming region, the influence of the dimensional effect cannot be ignored as the material size is reduced, and the friction force generated between the blank and the die increases compared to the case of the normal size, and the blank material is applied to the die. Prevents inflow and causes deterioration of workability. For this reason, a method for reducing the amount of friction has been required.

  The present invention has been made to solve the above-described problems in press molding, and its purpose is to reduce the frictional force without depending on the lubricant, and to obtain a desired molded product without being an expert. An object of the present invention is to provide a press molding apparatus that can be obtained and a control method thereof.

In order to achieve the above object, in the press molding apparatus according to claim 1,
A blank for plastically deforming a blank material to be processed into a desired shape, a punch for imparting deformation to the blank material, and wrinkle suppression in a direction perpendicular to the plate surface of the flange portion of the blank material A blank holder that presses and restrains the blank material against the die by applying force, storage means for storing press control basic data including an allowable wrinkle generation amount, a maximum punch speed value, and a minimum punch speed value;
Punch displacement imparting means capable of changing the punch speed during actual machining;
Wrinkle restraining force imparting means for imparting wrinkle restraining force to the blank holder during actual processing;
Measuring means for measuring a deformation amount of the predetermined portion of the blank material during actual processing;
While measuring the deformation amount of the predetermined portion of the blank material as actual measurement data using the measuring unit at the time of actual machining, the allowable wrinkle generation amount is read from the storage unit, and the read allowable wrinkle generation amount and the actual measurement data are read out The wrinkle generation amount real-time evaluation data calculated by comparing the above and the wrinkle generation state of the blank material based on the calculated evaluation data (good if no wrinkle is generated, otherwise A determination means for determining
If the result of the judgment means is negative at the time of actual machining, the first step of reducing the punching speed to the minimum punching speed, sufficient wrinkle suppression force until the judgment means judges that the wrinkle occurrence state is good Wrinkle erasing means for sequentially executing a second step of erasing wrinkles generated in the blank material and a third step of loading a sufficiently low wrinkle restraining force again,
When the result by the determination means is good during actual machining, a sufficiently low wrinkle restraining force is applied and the punch speed is increased to the maximum punch speed value. Achieved by a press forming apparatus comprising a control means for controlling the wrinkle restraining force applying means and the punch displacement applying means so as to erase wrinkles generated in the blank material based on the wrinkle erasing means. Is done.
It is desirable to set 0 to the minimum punch speed value included in the press control basic data and stop the punch during the wrinkle erasing process.

In the press apparatus according to claim 2, it is desirable that the measuring means measures the displacement of the blank holder as the amount of deformation of the blank material. When the blank holder is a split type, the displacement of each of the divided blank holders may be measured.

  The press forming apparatus according to claim 3 does not include the measuring means and the wrinkle occurrence state determining means provided in the press forming apparatus according to claim 1, and includes a wrinkle restraining force applying means and a punch displacement applying means. The press molding apparatus is characterized by being controlled by open loop control. Compared with the press apparatus according to claim 1, a simple control system is used. In particular, it may be used for microforming, in which it is difficult to control the wrinkle restraining force minutely and with high accuracy.

  In the press molding apparatus according to claim 4, the blank holder is a split type, and the blank holder is arranged only in a portion where wrinkle is prominent, and the necessary wrinkle restraining force is divided and loaded, and other portions With regard to, the wrinkle restraining force applied to the part can be sufficiently lowered even when the blank holder is not arranged or arranged, and it is preferable to use it for press molding of a non-axisymmetric part.

In the invention according to claim 5, at the time of actual processing in which the punch is lowered and the forming is advanced in a state where a sufficiently low wrinkle suppressing force is applied to the blank material, the measuring means is used in the flange portion of the blank material. The displacement of the predetermined portion in the direction perpendicular to the plate surface is measured in real time, and the quality of the wrinkle occurrence state is judged by comparing this measurement data with the allowable wrinkle generation amount read from the storage means. If it is determined that the wrinkle generation state is good, the molding process is continued until the result of the determination of the wrinkle generation state is negative. If the determination is negative, the punch speed is set to the minimum punch speed value. Then, the wrinkle restraining force is increased until it is determined that the wrinkle generation state is good. Then, if it is determined to be good, after reducing the wrinkle restraining force, the wrinkle is generated so that the maximum punch speed is increased again to the maximum punch speed value and molding is resumed. Based on the determination of the state, the wrinkle restraining force applying means and the punch displacement applying means are feedback-controlled.
According to the present invention, in the molding process, the molding can be performed in a state in which almost no wrinkle restraining force is applied at all times, so that it can be processed with a low frictional force generated between the blank material and the die. In addition, even when wrinkles occur, wrinkles are erased in a state where molding is temporarily interrupted, so that molding defects associated with wrinkle generation do not occur.

In the invention according to claim 6, at the time of actual processing in which the punch is lowered and the forming is advanced in a state in which a sufficiently low wrinkle suppressing force is applied to the blank material, the measuring means is used in the flange portion of the blank material. The displacement in the vertical direction of the plate surface of the predetermined part is measured in real time, the measured data is compared with the allowable wrinkle generation amount read from the storage means, and the quality of the wrinkle generation state is determined for each part corresponding to the divided blank holder. Judging. If it is determined that the wrinkle generation state is good, the molding process is continued until the result of determination of the wrinkle generation state is negative again. If the determination is negative, the punching speed is reduced. The wrinkle restraining force is increased until the wrinkle generation state is determined to be good in the blank holder at the site determined to be NO. Then, if it is determined to be good, after reducing the wrinkle restraining force, the wrinkle is generated so that the maximum punch speed is increased again to the maximum punch speed value and molding is resumed. Based on the determination of the state, the wrinkle restraining force applying means and the punch displacement applying means are feedback-controlled.
In the molding process, molding can always be performed with no wrinkle restraining force applied, and even when wrinkles occur, wrinkle restraining force is applied only to the parts that are necessary, so wrinkle generation behavior is Even molding with a complicated non-axisymmetric shape does not cause molding defects due to wrinkling.

  In the invention according to claim 8, the punching speed is set to the minimum punching speed at a predetermined timing at the time of actual processing in which the punch is lowered and forming is performed with a sufficiently low wrinkle restraining force applied to the blank material. A wrinkle erasing process is performed in which the first step of reducing the wrinkle is increased, the second step of increasing the wrinkle suppression force to erase the wrinkles generated in the blank material, and the third step of loading a sufficiently low wrinkle suppression force again. Then, the wrinkle restraining force applying means and the punch displacement imparting means are controlled in an open loop so that the punch is lowered and molding is continued in a state where a sufficiently low wrinkle restraining force is applied to the blank material.

  According to the present invention, the frictional force between the blank material and the die can be reduced without using a special technique such as a high-cost ultrasonic device or a mold coating technique, and non-lubrication press molding is realized. At the same time, it is possible to expect an improvement in the mold life by reducing the frictional force between the blank material and the die. In particular, in application to microforming where reduction of the frictional force between the blank material and the die is a big problem, improvement in formability can be expected. Similarly, in the drawing of ultrathin plates and foil materials, flange wrinkles are likely to occur, and it is strongly required to appropriately control the wrinkle suppressing force that suppresses the generation of wrinkles. There is no need for control, and at the same time, improvement in formability with wrinkle elimination can be expected. Furthermore, press molding based on appropriate wrinkle restraining force and press motion control can be carried out even if not skilled. In particular, by using a split blank holder, it can be applied to non-axisymmetric molding, so that a large ripple effect can be expected.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a conceptual diagram showing a main part of a press molding apparatus according to the present invention. In the drawing, the blank material 4 ′ before molding is shown on the left side, and the blank material 4 being molded is shown on the right side. The press forming apparatus includes an actuator group including a die 3, a blank holder 2, a punch 1, a punch displacement applying portion (not shown), and a wrinkle restraining force applying portion (not shown), and wrinkle generation. A quantity detection sensor group (not shown) and a control unit (not shown) are provided. Further, the wrinkle restraining force applying means and the punch displacement applying means include those using a cylinder actuator such as an air cylinder or a hydraulic cylinder. The sensor group can measure the displacement of a non-contact displacement sensor such as a laser displacement sensor in addition to a mechanical displacement sensor using a contactor.

  FIG. 2 is a conceptual diagram showing a main part of a press apparatus using a split-type blank holder for non-axisymmetric press forming. A plurality of the split type blank holders 6 are arranged in the flange portion, and are divided in the inflow direction of the blank material and the direction perpendicular thereto. The blank holder is not arranged for the portion where the possibility of wrinkle generation is low, and the wrinkle restraining force is applied only to the necessary portion.

  FIG. 3 is a diagram showing the displacement (BHD) of the blank holder caused by wrinkling of the blank material. The wrinkle generation amount of the flange portion of the blank material can be obtained by measuring the displacement of the blank holder.

<Determination of wrinkle occurrence state>
The determination of the wrinkle occurrence state is performed based on the measurement data of the wrinkle height at the blank end. In this embodiment, the amount of wrinkle generated at the flange end of the blank material is substituted by blank holder displacement (BHD), and in each molding stage, it is acceptable to compare BHD with two types of allowable values described below. To be judged.
As the two types of allowable values, the maximum allowable wrinkle generation amount (UPT) and the minimum allowable wrinkle generation amount (LPT) can each be a constant value. Can also be used.

Number 001

UPT = A ₁ + A ₂ × ΔDR ^*

002

LOT = B ₁ + B ₂ × ΔDR ^*
Here, A ₁ and A ₂ and B ₁ and B ₂ are constant values, and are selected so that UPT> LOT. ΔDR ^* represents the degree of processing based on the blank diameter reduction rate, and is given by the following equation.

Number 003

ΔDR ^* = (Dp−2 × r) / Dp
Here, Dp is the punch diameter, and r is the blank end radius.
In the molding process, the wrinkle generation state is judged

Number 004

BHD ≦ UPT
Good when meeting,

005

BHD> UPT
It is determined that the condition is satisfied. In the wrinkle erasing process,

006

BHD ≦ LOT
Good when meeting,

Number 007

BHD> LOT
It is determined that the condition is satisfied.

<Outline of control>
A specific method for controlling the pressing apparatus corresponds to executing the following six-stage operation.
As a first step, the quality of the wrinkle generation state is determined in real time based on the measurement data of the wrinkle generation amount obtained by measuring the displacement amount (BHD) of the blank holder in real time. As a second step, as a result of the judgment on the wrinkle generation state during the molding process, the molding process is continued while it is good. Reduce. In the wrinkle erasing step in the third stage, after sufficiently reducing the punching speed, the wrinkle restraining force control means is controlled to increase the wrinkle restraining force while it is determined that the wrinkle occurrence state is negative. If it is determined that the wrinkle generation state is good, the wrinkle restraining force is reduced.
As a fourth stage, the punching speed is increased again and the molding process is restarted.
As the fifth stage, the operations from the first stage to the fourth stage are repeated until the molding is completed.

  An outline of the above press apparatus control method will be described with reference to FIG. 4 showing deep drawing. The deep drawing process is performed when the possibility of wrinkling and its growth is low, as shown in FIG. On the other hand, as shown in (b), if the wrinkle generation state is more than allowable, the punch is controlled to stop as shown in (c) and the drawing process is stopped to eliminate the wrinkle, and the BHF is loaded. Is done. In this wrinkle erasing step, an increase in punch load can be avoided. In the stage (d), when the wrinkles are sufficiently erased, the BHF is unloaded, and as shown in (e), the punch starts to descend again and the molding process is continued.

  The principle of the control method in the present invention is to load the wrinkle restraining force only when necessary. That is, the wrinkle restraining force is applied to the blank material in order to eliminate the wrinkle when it occurs at the flange end. At the same time, the punch is stopped and drawing is interrupted. During molding, by using a force that does not impose a wrinkle restraining force or is sufficiently small, the molding can be performed with a small frictional force between the blank material and the die. Further, when wrinkles are generated, wrinkle growth is completely suppressed by setting the punching speed sufficiently low, and wrinkles can be reliably erased by applying a wrinkle suppressing force in this state. Therefore, an increase in frictional force accompanying an increase in wrinkle restraining force can be reduced.

<Flow of wrinkle occurrence state determination processing>
FIG. 5 shows a flowchart of wrinkle occurrence state determination processing for controlling the control means in the press molding apparatus of the present embodiment.
In order to measure the deformation amount of the predetermined portion of the blank material using the measuring means, the blank holder displacement amount (BHD) is acquired (ST100). Then, it is determined whether the press apparatus state at that time is a forming process or a wrinkle erasing process (ST101). If it is a molding process, UPT is read from parameter press control basic data and set in parameter T (ST102). If it is a wrinkle erasing process, the LOT is read from the press control basic data and set in the parameter T (ST103).
Thereafter, the obtained BHD and T are compared in magnitude, and if the relationship of BHD <T is established, it is determined that the wrinkle occurrence state is good (ST105). (ST106).

<Flow of wrinkle erasing process>
FIG. 6 shows a flowchart showing a process of a wrinkle erasing process for erasing wrinkles of the blank material in the press molding apparatus of the present embodiment.
When the wrinkle erasing process starts, the punching speed is first reduced (ST110), and it is determined whether the speed is sufficiently reduced (ST111). This determination can be made, for example, by storing the minimum punch speed in the storage means and comparing the speed value with the actual punch speed at the time of determination.
After the punching speed is sufficiently decelerated, the wrinkle restraining force applied to the blank is increased by an increment ΔBHF by the wrinkle restraining force applying means (ST112).
The wrinkle occurrence state is determined (ST130), and the process shown in ST112 is repeated until it is determined to be good, and the wrinkle suppressing force is increased.
If it is determined that the wrinkle generation state is good, the wrinkle restraining force is decreased (ST114), the punching speed is increased again (ST115), and the molding process is restarted.

<Flow of overall control operation>
FIG. 7 shows a flowchart of overall control in the press molding apparatus of the present embodiment.
In the case of processing a blank material as shown in FIG. 1 using this embodiment, first, the blank material is placed at a predetermined position on the die, and the blank material is restrained by applying a wrinkle suppressing force. (ST120). If there is a molding start instruction input to the press device (ST122), the control unit starts real-time measurement of the sensor group belonging to the measurement unit that measures the deformation amount of the predetermined part of the blank material (ST123), and real-time measurement. Judgment of the wrinkle occurrence state is started based on the data, and the minimum wrinkle suppressing force value is read from the storage unit (ST124), and the punching speed is increased to start molding (ST126). After the start of molding, a wrinkle erasing process is performed based on the determination result of the wrinkle occurrence state, and the processes of ST127 to ST129 are repeated until the molding is completed.

  FIG. 8 shows a functional block diagram of a configuration for controlling the press molding apparatus based on the principle described above. The press molding apparatus according to the present embodiment includes an actuator group 60 that drives various parts, a control unit 50, and a storage unit 40. The control unit 50 and the storage unit 40 are implemented in a computer system.

  The press forming apparatus in the present embodiment is a micro forming press apparatus having a micro forming mold used for forming a micro dimension product in addition to a mold intended for general macro scale forming. It is included as one of the embodiments of the present invention. In microforming press devices, the required amount of wrinkle restraining force is very small, and it is generally difficult to introduce wrinkle restraining force imparting means that directly controls the force. As the wrinkle restraining force means, a means that indirectly applies the wrinkle restraining force as a result of the displacement control mechanism may be used.

なお本発明による制御方法は成形中期に対して適用した。
しわ抑え力（ＢＨＦ）及びパンチ速度（ＳＰＤ）の制御値の履歴を図９に示す。制御アルゴリズムが適切に作動していることがＢＨＤ、ＢＨＦとＳＰＤの挙動より確認することができる。
また、しわ抑え力及びパンチ荷重の履歴を図１０（ａ）及び（ｂ）のグラフに示す。しわ抑え力の急激な増減は、この間にしわ消去工程が行われていることを示している。
同グラフ中の最大パンチ荷重を比較すると最大で５％程度低下していることがわかる。When the blank material is deformed by controlling the wrinkle restraining force and the press motion as described above using the press apparatus as shown in FIG. 1 (Example), the constant wrinkle restraining force and the constant punch without controlling. The case where the blank was deformed at a speed (comparative example) was compared using an elastoplastic finite element simulation. The blank material was assumed to be a mild steel plate having a thickness of 0.5 mm, and a forming simulation was performed under a drawing ratio of 2.06. The tool dimensions used are as shown in the table below.

The control method according to the present invention was applied to the middle stage of molding.
FIG. 9 shows a history of control values for the wrinkle restraining force (BHF) and the punch speed (SPD). It can be confirmed from the behavior of BHD, BHF and SPD that the control algorithm is operating properly.
In addition, the history of wrinkle restraining force and punch load is shown in the graphs of FIGS. The rapid increase / decrease of the wrinkle restraining force indicates that the wrinkle erasing process is being performed during this time.
Comparing the maximum punch load in the graph, it can be seen that the maximum drop is about 5%.

なお、σ_ｍは静水圧応力、σ_ｅｑは相当応力、ε_ｅｑは相当ひずみ、ε_ｅｑｆは破壊時の相当ひずみである。
図１１に示すように、制御を適用した場合には、ダメージ値の低下が確認できる。すなわち、成形性の向上に対する効果が確認できる。Processing Limit FIG. 11 shows results of calculating and comparing the ductile fracture damage values according to the Oyane ductile fracture condition formula.
Here, the following formula is used as a ductile fracture condition formula of Oyane, and the time when I = 1 is treated as a fracture in the simulation.

Σ _m is the hydrostatic stress, σ _eq is the equivalent stress, ε _eq is the equivalent strain, and ε _eqf is the equivalent strain at the time of fracture.
As shown in FIG. 11, when the control is applied, a decrease in the damage value can be confirmed. That is, the effect on the improvement of moldability can be confirmed.

It is principal part sectional drawing of the press molding apparatus which is 1st Embodiment of this invention. It is principal part sectional drawing of the press installation for press molding of a non-axisymmetric shape among embodiment of this invention. It is a figure explaining the measurement site | part used for a mode that wrinkles generate | occur | produce, and judgment of a wrinkle generation | occurrence | production state. It is a figure explaining the outline | summary of the press apparatus control method of this invention. It is a flowchart which shows the flow of judgment of a wrinkle occurrence state. It is a flowchart explaining the flow of a process in a wrinkle elimination process. It is a flowchart which shows an example of the operation | movement in this Embodiment. It is a block diagram which shows an example of this Embodiment. It is a history of punch load and wrinkle restraining force in an example of this embodiment. It is a graph which shows the history of operation in an example of this embodiment. It is a graph which shows the log | history of the ductile fracture damage value in an example of this Embodiment.

Explanation of symbols

1 Punch 2 Blank holder 3 Die 4 Blank material forming)
5 Wrinkle suppression imparting means connecting part 4 'Blank material (initial)

Claims (8)

A blank for plastically deforming a blank material to be processed into a desired shape, a punch for imparting deformation to the blank material, and wrinkle suppression in a direction perpendicular to the plate surface of the flange portion of the blank material A blank holder that presses and restrains the blank material against the die by applying force, storage means for storing press control basic data including an allowable wrinkle generation amount, a maximum punch speed value, and a minimum punch speed value;
Punch displacement imparting means capable of changing the punch speed during actual machining;
Wrinkle restraining force imparting means for imparting wrinkle restraining force to the blank holder during actual processing;
Measuring means for measuring a deformation amount of the predetermined portion of the blank material during actual processing;
While measuring the deformation amount of the predetermined portion of the blank material as actual measurement data using the measuring unit at the time of actual machining, the allowable wrinkle generation amount is read from the storage unit, and the read allowable wrinkle generation amount and the actual measurement data are read out The wrinkle generation amount real-time evaluation data calculated by comparing the above and the wrinkle generation state of the blank material based on the calculated evaluation data (good if no wrinkle is generated, otherwise A determination means for determining
If the result of the judgment means is negative at the time of actual machining, the first step of reducing the punching speed to the minimum punching speed, sufficient wrinkle suppression force until the judgment means judges that the wrinkle occurrence state is good Wrinkle erasing means for sequentially executing a second step of erasing wrinkles generated in the blank material and a third step of loading a sufficiently low wrinkle restraining force again,
When the result by the determination means is good during actual machining, a sufficiently low wrinkle restraining force is applied and the punch speed is increased to the maximum punch speed value. A press forming apparatus comprising: a control unit that controls the wrinkle suppressing force applying unit and the punch displacement applying unit so as to erase wrinkles generated in the blank material based on the wrinkle erasing unit. 2. The press forming apparatus according to claim 1, wherein the measuring unit measures a displacement amount in a direction perpendicular to the plate surface at least one of wrinkle-prone portions at a flange end portion of the blank material. . A blank for plastically deforming a blank material to be processed into a desired shape, a punch for imparting deformation to the blank material, and wrinkle suppression in a direction perpendicular to the plate surface of the flange portion of the blank material A blank holder for applying a force to restrain the blank material against the die, and a storage means for storing press control basic data including a maximum punch speed value and a minimum punch speed value;
Punch displacement imparting means capable of changing the punch speed during actual machining;
Wrinkle restraining force imparting means for imparting wrinkle restraining force to the blank holder during actual processing;
At a predetermined timing during actual machining, a first step for reducing the punching speed to the minimum punching speed, a second step for increasing wrinkle restraining force and erasing wrinkles generated in the blank material, and a sufficiently low wrinkling restraining force again. Wrinkle erasing means for sequentially executing a third step of loading
During actual machining, a sufficiently low wrinkle restraining force is applied and the punch speed is increased to the maximum punch speed value, while the wrinkles generated in the blank material are erased based on the wrinkle erasing means at a predetermined timing. And a control means for controlling the wrinkle restraining force applying means and the punch displacement applying means in an open loop. The said blank holder is a split-type blank holder arrange | positioned according to the site | part which generation | occurrence | production of a wrinkle is remarkable in the said blank material, The press molding apparatus in any one of Claims 1-3 characterized by the above-mentioned. A first stage of placing a blank material on a die and loading the blank holder with a sufficiently low wrinkle restraining force so that the blank material is restrained by the mold;
A second step of storing press control basic data including an allowable wrinkle generation amount and a maximum punch speed value and a minimum punch speed value;
A third stage in which the punching speed is increased to the maximum punch speed value with respect to the constrained blank material, and the molding proceeds.
The measurement unit is used to acquire the deformation amount of a predetermined portion of the blank as actual measurement data, and the allowable wrinkle generation amount is read from the storage unit, and the read allowable wrinkle generation amount is compared with the actual measurement data. Calculating a wrinkle generation amount real-time evaluation value obtained by the above, and determining the quality of the wrinkle generation state of the blank material based on the calculated evaluation value;
When it is determined that the wrinkle occurrence state is good in the fourth stage, the fifth stage in which molding is performed while maintaining the punch speed at that time or increasing the punch speed to the maximum punch speed value;
If it is determined in the fourth stage that the result is NO, as a wrinkle erasing step, a first step of reducing the punch speed to the minimum punch speed, until the determination means determines that the wrinkle occurrence state is good A sixth step of sequentially executing a second step of erasing wrinkles generated in the blank material by sufficiently increasing the wrinkle restraining force and a third step of loading a sufficiently low wrinkle restraining force again,
A press molding apparatus control method comprising: a seventh stage in which the processes from the third stage to the sixth stage are repeated until molding is completed. A control method of a press molding apparatus provided with a split blank holder,
A first stage in which a blank material is placed on a die and a sufficiently low wrinkle restraining force is applied to each of the blank holders to restrain the blank material to a die and restrained at a predetermined position of the die;
A second step of storing press control basic data including an allowable wrinkle generation amount and a maximum punch speed value and a minimum punch speed value;
A third stage of starting molding by increasing the punch speed to the maximum punch speed value for the constrained blank material;
The measurement unit is used to acquire the deformation amount of a predetermined portion of the blank as actual measurement data, and the allowable wrinkle generation amount is read from the storage unit, and the read allowable wrinkle generation amount is compared with the actual measurement data. Calculating a wrinkle generation amount real-time evaluation value obtained by the above, and determining the quality of the wrinkle generation state of the blank material based on the calculated evaluation value;
When it is determined that the wrinkle occurrence state is good in the fourth stage, the fifth stage in which molding is performed while maintaining the punch speed at that time or increasing the punch speed to the maximum punch speed value;
If it is determined in the fourth stage that the result is NO, as a wrinkle erasing step, a first step of reducing the punch speed to the minimum punch speed, until the determination means determines that the wrinkle occurrence state is good , A second step of sufficiently increasing the wrinkle restraining force only on the blank holder corresponding to the part determined to be no and erasing wrinkles generated in the blank material, a third step of applying a sufficiently low wrinkle restraining force again, The sixth stage of sequentially executing,
A press molding apparatus control method comprising: a seventh stage in which the processes from the third stage to the sixth stage are repeated until molding is completed. The press molding apparatus control method according to claim 5 or 6, wherein the measurement is performed with respect to a displacement amount in a direction perpendicular to a plate surface in a flange portion of the blank material. A first stage of placing the blank material on a die and loading the blank holder with a sufficiently low wrinkle restraining force such that the blank material is restrained by the mold;
A second stage for storing press control basic data including a maximum punch speed value and a minimum punch speed value;
A third stage in which the punching speed is increased to the maximum punch speed value with respect to the constrained blank material, and the molding proceeds.
At a predetermined timing during actual processing, as a wrinkle erasing process, a first step for reducing the punching speed to the minimum punching speed, a second step for increasing the wrinkle restraining force and erasing wrinkles generated in the blank material, again sufficiently A fourth step of sequentially executing a third step of applying a low wrinkle restraining force;
A press molding apparatus control method comprising: a fifth stage in which the third stage and the fourth stage are repeated until molding is completed.

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