JP5686509B2 - Transfer press molding equipment - Google Patents

Description

The present invention relates to a transfer Puresu molding apparatus, in particular, ferrous, non-ferrous, and the time of press-molding the various metal materials of the laminate or the like, the suppression of molding defects phenomena, inhibition of production defect occurs, the operation energy during production The present invention relates to a technique suitable for saving and the like.

Metallic press molding is widely used for manufacturing automobiles, industrial machines, electrical equipment, transportation equipment, and the like because it is highly productive and can be processed with high precision. Technique called transfer Puresu molding Among these is high particularly productive, now being applied to a number of parts production. In recent years, in the automotive field, complex press molding has been required for front side members, rear side members, lockers, pillars, etc., in order to achieve both collision safety and weight reduction leading to CO ₂ emission reduction. to the component there is an increasing attempt to apply the high strength steel sheet, a further improved accuracy of the transfer Puresu molding apparatus used in these molding, productivity improvement has been desired.

Technology Transfer Puresu molding, for example, disclosed in Patent Document 1. The transfer Puresu molding of the products manufactured in multiple steps, and contact between the several sets of independent molds for processing each step, from the die of the previous step to mold the next step It is an automatic processing method that uses a transfer device that delivers processed products together.

In transfer Puresu molding, while performing sequential what step of secondary processing simultaneously go machining process continuously is advanced until the product after the final step way at all by not requiring human intervention is taken out. At that time, if the press processing conditions in each mold are constant over time, the shape, thickness, and surface state of the molded product after pressing are constant. The press working conditions in each mold fluctuate, and this may cause sudden failure of the press-formed product such as cracks and wrinkles, and variations in dimensional accuracy.

In transfer Puresu molding, high productivity since it will automatically and continuously machining process is advanced as described above, when there is a high productivity because, variable condition occurs, the number of defective products due to this Increases compared to a normal press. The occurrence of inferior goods due to this change in conditions becomes prominent particularly in the case of press forming of the above-described high-strength steel sheet.

Until now, however, the correction of this condition variation has to be performed after the product is taken out after the final process and the occurrence of defective products or the like is confirmed. Therefore, highly accurate production can transfer Puresu molding apparatus has been awaited by rapid correction of this condition change.
(Suppression of production defects)
Further, in the conventional transfer Puresu forming apparatus automatically and due to the continuously the processing step will proceed, even defective occurs, the contaminating its discovery in normal component becomes difficult However, there is a problem that the process in which the defective product is generated is not clarified and the countermeasure is difficult.

Furthermore, in the conventional transfer Puresu molding apparatus also defective occurs, in order to become processed in a subsequent step as with normal parts, it would pressed in a subsequent step the defectives example overlapping wrinkles occurred In some cases, the mold is damaged, and a defective part having a crack is trimmed in a subsequent process, so that trim waste cannot be discharged well and is clogged.

When these production failures occur, a great deal of time and effort are required for countermeasures and recovery. Therefore, these production defect occurrence transfer Puresu molding apparatus capable of suppressing has been awaited.
(Saving operating energy during production)
Further, in the conventional transfer Puresu molding apparatus also defective occurs, resulting in processed in a subsequent step as with normal parts. Against defective, is subjected to processing similar to the normal components, operating energy transfer Puresu molding apparatus, in particular power, hydraulic, nothing but the fact that wasting air pressure and the like It was a problem from the viewpoint of energy saving and CO ₂ emission reduction. These were transfer Puresu molding apparatus capable of suppressing unnecessary consumption of operation energy has been awaited.

JP 2007-144495 A

The present invention, taking advantage of high productivity of the transfer Puresu molding apparatus, the mold of the press molding conditions quickly and can also vary, and by properly corrected, defective products generated during the machining providing a transfer Puresu molding apparatus which can be much more reduced compared to the number in the conventional apparatus, further inhibiting the production defect occurrence, to provide a transfer Puresu molding apparatus capable operating energy savings during production Is an issue.

The present invention has been made in order to solve the above-mentioned problems, and the gist thereof is the following contents as described in the scope of claims.
(1) A plurality of molds for forming a workpiece by relative movement of a punch and a die, and a workpiece conveying device for conveying the workpiece between the plurality of molds, the plurality The first press mold is a first press mold for forming a workpiece in succession when at least one of the punch and the die is a measurement target mold. Strain measuring means installed inside the measurement target mold and measuring the elastic strain generated in the measurement target mold according to the stroke during press molding, and when the elastic strain exceeds a predetermined range or a predetermined range A molding abnormality prediction means for predicting a molding abnormality when it falls below, and a second mold that is placed after the first mold and corrects the shape of the workpiece is a prediction result of the molding abnormality. Based on the above, at least one kind of press load and molding speed Transfer press molding apparatus characterized by comprising control means for controlling the.
(2) Further, the first mold has at least one of a pad and a crease presser mold interlocked with the relative movement of the punch and the die. Transfer press molding equipment.
(3) The transfer press molding apparatus according to (1) or (2), wherein the strain measuring means is a piezoelectric element or a strain gauge.

According to the present invention, even if the press molding conditions of each mold fluctuate, this can be corrected promptly and appropriately, so that the number of defective products generated during processing is far greater than that of conventional devices. after which it is possible to provide a transfer Puresu forming apparatus which can reduce the suppression of the production defect occurrence, such as it can provide a transfer Puresu forming apparatus can be operated energy savings during production, significant on useful industrial There is an effect.

Is a diagram illustrating an example of a configuration related transfer Puresu forming apparatus according to (1). Is a diagram illustrating an example of a configuration related transfer Puresu forming apparatus according to (1). It relates transfer Puresu forming apparatus according to (1), is a diagram showing an example of a desired installation position of strain measurement means 702. Relates transfer Puresu molding apparatus of (1) is a diagram showing an example of a desired installation position of strain measurement means 702. It relates transfer Puresu forming apparatus according to (1) shows an example of a specific configuration of the strain measuring means 702. It is a figure which shows the molding defect determination method as described in (1). It is a figure which shows the flowchart regarding the control method of the press load and forming speed as described in (1). Is a diagram illustrating an example of a configuration related transfer Puresu forming apparatus according to (2). FIG. 3 is a diagram showing the shape of a press part molded in Example 1. In transfer Puresu forming apparatus fabricated in Example 1, indicating the installation position of strain measurement means 702 In transfer Puresu forming apparatus fabricated in Example 1, showing the molding defect determination method. It is a figure which shows the shape of the press component shape | molded in Example 2. FIG. In transfer Puresu forming apparatus fabricated in Example 2, a diagram illustrating the installation position of strain measurement means 702. In transfer Puresu forming apparatus fabricated in Example 2, showing the molding defect determination method.

Hereinafter, with reference to the accompanying drawings, it will be described with reference to various embodiments of the transfer Puresu molding apparatus according to the present invention.

First, the invention described in (1) and (3) will be described. An example of the transfer Puresu molding apparatus according to the present invention shown in FIG.

Figure 1 is a view of the transfer Puresu molding apparatus according to the present invention from the side. Transfer Puresu molding apparatus of Figure 1 includes a punch 101 to 104 and the die 201-204. The punch 101 and the die 201, the punch 102 and the die 202, the punch 103 and the die 203, and the punch 104 and the die 204 constitute a mold for forming the workpieces 501 to 504 by relative movement. That is, FIG. 1 has a four-step mold. The punch 101 and the die 201 are molds for performing press molding in the first step, particularly form molding, and are used for processing the workpiece 501. The workpiece 501 is processed while being positioned by a nest guide 901 or other positioning means (not shown).

  The punch 102 and the die 202 are molds for performing press molding in the second process, particularly form molding, and are used to rework the workpiece 501 molded by the press molding in the first process. The workpiece 502 is processed while being positioned by a nest guide 901 or other positioning means (not shown).

  The punch 103 and the die 203 are molds that perform press molding in the third step, particularly trim molding, and are used to rework the workpiece 502 formed by the press molding in the second step. The workpiece 502 is processed while being positioned by positioning means (not shown).

  The punch 104 and the die 204 are molds that perform press molding in the fourth step, particularly, re-striking, and are used to rework the workpiece 503 formed by the press molding in the third step. . The workpiece 502 is processed while being positioned by positioning means (not shown).

It is shown a mold of 4 steps as an example in FIG. 1, if the transfer Puresu molding apparatus having two or more steps of the mold, the present invention is applicable.

Also, transfer Puresu molding apparatus of FIG. 1 includes a workpiece transport device 601, 603, the workpiece transfer apparatus 602 which does not appear in Figure 1. These workpiece conveying apparatuses will be described in detail with reference to FIG.

Figure 2 is a view of the transfer Puresu molding apparatus according to the present invention from the upper surface. The workpiece conveying device 601 conveys a sheet-like workpiece separated from a stack by a stacker (not shown) or a sheet-like workpiece separated from a coil by a shearing facility (not shown) until just before the first step. It is a device to do. This is conveyed by the workpiece transport device 601, the first step th workpiece waiting to be fed to the mold transfer Puresu molding apparatus is workpiece 500. The workpiece conveying apparatus 602 is an apparatus for conveying a workpiece between the above-described molds.

  The workpiece conveying device 602 shown in FIG. 2 is composed of two finger rails 604 in total, one on the left and right when viewed in the product feed direction, and a total of ten fingers 605, five on each finger rail. Yes.

  The finger 605 has a function of grasping (clamping) a workpiece located in the workpiece conveyance device 601 or each process die, and releasing (unclamping) after being conveyed to the next process. The finger 605 has a claw-like shape and realizes the above function by hooking the workpiece, and the finger 605 grips the workpiece by driving with a driving force such as air pressure or an electromagnetic motor. There is. In the case of the driving type, the driving timing is adjusted to synchronize with the operation of the finger rail 604 and each process mold.

  The finger 605 is fixed to the finger rail 604. The fixing position of the finger 605 is the function described above when the finger rail 604 is operated, that is, the function of grasping the workpiece and releasing it after being transported to the next process. It is attached after adjusting so that it is not hindered.

  The finger rail 604 has a function of conveying the workpiece located in the workpiece conveying apparatus 601 or each process die to the next process using the above-described finger 605. The operation is composed of four types of operations of clamping, advance, unclamping, and returning. By repeating these four types of operations in order, the function of conveying the workpiece is realized.

  The operation of the clamp is an operation in which the finger rail 604 located on the upper side in FIG. 2 moves downward and the finger rail located on the lower side moves upward to bring the above-described finger 605 closer to or close to the workpiece. . After this operation, finger 605 grips the workpiece. The advance operation is an operation in which the workpiece is moved in the feeding direction in FIG. 2 while being gripped by the fingers 605, and all the workpieces in each process die are conveyed to the next process. After this operation, finger 605 releases the workpiece.

  The unclamping operation is an operation in which the finger rail 604 located on the upper side in FIG. 2 moves upward, the finger rail located on the lower side moves downward, and the finger 605 separated from the workpiece is moved away from the workpiece. . The return operation is an operation that moves in the direction opposite to the feed direction in FIG. 2 and prepares for the next clamp operation.

Workpiece transport device 603 is a device for conveying the workpiece which has been molded in the final step mold transfer Puresu molding apparatus, to another step such as welding and assembly. The workpiece 505 is a workpiece that is about to be transported to another process by the workpiece transport device 603.

Also, transfer Puresu molding apparatus of FIG. 1, a first mold, a punch 102, selects a mold for molding the workpiece 502 by the relative movement of the die 202, further selected die 202 as measured mold The strain measuring means 702 is installed inside the die 202.

  The workpiece 502 is pressed against the punch 102 by the die 202 and formed into a predetermined shape. At this time, a strain measuring means 702 described below is installed in the vicinity of the curved convex shape formed on the surface of the punch 102 or the die 202 and inside the mold, and by monitoring the amount of the strain, cracks and wrinkles, We have found that it is possible to determine molding anomalies such as springback or mold anomalies such as mold galling.

  In order to determine molding abnormalities such as cracks, wrinkles, and springbacks effectively, the installation position of the strain measuring means 702 is important. A desirable installation position of the strain measuring means 702 is shown in FIGS.

  FIG. 3 shows the case where the die 202 is installed on the press machine slide, and FIG. 4 shows the case where the punch 102 is installed on the press machine slide. In either case, the installation position of the strain measuring means 702 is When the punch 102 and the die 202 are used as the measurement target mold, when the measurement target mold, that is, the punch 102 and the die 202 are at the bottom dead center position, the pressing direction is more than the die shoulder R stop on the material outflow side. It shall be located on the side.

This is because the breakage of the mold caused by the installation of the strain measuring means 702 to first, is because to avoid damage. In particular the die 202, the strain measuring means 702 is not positioned in the press direction than the die shoulder R blind material outlet side, the risk of insufficient dimensional accuracy in drilling for mounting the strain measuring means 702 Expensive . In general, drilling is used for drilling for mounting the strain measuring means 702, the less meat in between the time the hole for mounting the strain measuring means 702 and the die 202 surface, the insufficient rigidity of the drill, would bent drill the small direction of meat, the problem of insufficient dimensional accuracy is likely to occur. When this problem occurs, the feature size becomes direction meat is less than the specified size, i.e. in the direction in which the increased danger of breakage, in order to avoid this problem occurs, the strain measurement means 702 of the material outlet It is desirable to be located on the press direction side from the die shoulder R stop on the side .
The crack or the like occurs in the heat treatment, a high probability of occurrence of machining failure other than drilling. Even as the hole machining and heat treatment is successful, there is a high risk of corruption in the midst of repeated use of the mold by insufficient strength.
Next, FIGS. 5a and 5b are diagrams showing a specific configuration example of the strain measuring means 702 described above. As an example of the installation method of the strain measuring means 702, as shown in the schematic diagram of FIG. 5a, a hole that does not penetrate the die 202 is made and a female screw is cut, and a strain sensor 902 shown in FIG. 5b is inserted in the bottom of the hole. There is a method of press-fitting by applying axial force with a plug. As the strain sensor 902, use of a strain gauge, a piezoelectric element, an FBG sensor using an optical fiber, or the like is conceivable. In this case, if a piezoelectric element or a strain gauge is used, the frequency response characteristic can be reduced while suppressing the construction cost. Highly favorable measurement is possible.

Also, transfer Puresu molding apparatus of FIG. 1 predicts a molding abnormality is press load, the control means 803 and control means 804 for controlling at least one or more kinds of forming speed installed. When the elastic strain measured by the strain measuring unit 702 exceeds a predetermined range or falls below the predetermined range, the control unit 803 predicts a molding abnormality, and presses the mold in the third step, Control at least one of the molding speeds.

  When the elastic strain measured by the strain measuring unit 702 exceeds a predetermined range or falls below the predetermined range, the control unit 804 predicts a molding abnormality, and presses the mold in the third step, Control at least one of the molding speeds.

  A method for predicting molding abnormality by the control means 803 or 804 will be described with reference to FIG. FIG. 6 is a graph showing the result of strain measurement by the strain measuring means 702. The horizontal axis is the forming stroke S. The press slide position at the start of forming the workpiece 502 is Sstart, and the press slide at the end of forming the workpiece 502 after reaching the forming bottom dead center. The position is Send. The vertical axis represents the amount of strain. Here, the amount of strain represents the compressive strain as a positive value.

  The dotted lines G1 and G2 in the figure represent the upper and lower limits of the predetermined strain amount range, respectively. Here, a method for determining the upper limit and the lower limit of the predetermined strain amount range will be described. Perform press forming a plurality of times, and collect the amount of strain during press forming without any abnormality in the molded product. The strain amount obtained by collecting 10 or more strain amounts during press forming without abnormality and averaging them is defined as an average strain amount for determining molding abnormality.

  In addition, in the multiple press forming described above, the amount of strain at the time of press forming in which there is an abnormality in the molded product is collected, and the amount of strain exceeding 10 times of the average strain amount is collected and averaged. Is the upper limit of the predetermined strain range.

  In addition, in the multiple press forming described above, the amount of strain at the time of press forming in which there is an abnormality in the molded product is collected, and the strain amount that is averaged by collecting 10 or more strain amounts below the average strain amount. Is the lower limit of the predetermined strain range.

  FIG. 6 shows, as an example, three strain measurement results: strain measurement result 1), strain measurement result 2), and strain measurement result 3). Of these, strain measurement result 1 ) Is within the predetermined strain range, it is determined that there is no problem in molding. On the other hand, since the strain amount measurement result 2) has a portion exceeding the upper limit of the strain amount predetermined range, it is determined that the molding is abnormal. In addition, since the strain amount measurement result 3) has a portion below the lower limit of the strain amount predetermined range, it is determined that the molding is abnormal. As described above, the molding abnormality of the press-formed product is determined.

In particular, the region forming stroke S is equal to or more than 50% of the Send, i.e. in the latter molding, if there is a portion where the strain amount measuring result is below the lower limit of the strain amount predetermined range (for 3), cracks press-or It is determined that necking has occurred .
In particular, the region forming stroke S is equal to or less than 50% of the Send, i.e. in the first half mold (in the case of 2) If there is a portion where the strain amount measuring result exceeds the upper limit of the strain amount predetermined range, spring back to press- Alternatively, it is determined that an inflow amount abnormality has occurred .
In particular, it determines a region forming stroke S is equal to or more than 50% of the Send, i.e. in the latter molding, if there is a portion exceeding the upper limit of the strain amount measuring result strain amount predetermined range, the wrinkle is generated in the press-molded article .
Next, a method for controlling the press load and molding speed of the mold for each molding abnormality predicted by the control means 803 or 804 will be described with reference to the flowchart shown in FIG.

  In the flowchart shown in FIG. 7, determination operation 820: start of press molding? , Processing operation 821: measurement of mold strain amount, determination operation 822: press forming completed? , Judgment operation 823: Cracking or necking occurred? , Processing operation 824: command 01 to each control means, determination operation 825: springback, inflow amount abnormality occurred? , Processing operation 826: command 02 to each control means, determination operation 827: wrinkle generated? , Processing operation 828: command 03 to various control means, processing operation 829: command 04 to various control means are performed. Hereinafter, assuming each operation performed when the N-th workpiece is formed during continuous production, each operation will be described in turn.

  Judgment operation 820: Press molding started? Then, it is determined whether press molding has been started. Here, it is determined that the press molding has started when the press machine slide that has been waiting at the standby position starts operating and the operation progresses to the die touch position of the upper and lower molds.

  When the work material is set at a fixed position of the lower die, when the slide moves to the die touch position of the upper and lower dies, the work material is sandwiched between the upper and lower dies, and molding is started.

  When the workpiece is not put into the lower mold, the molding of the workpiece is not started even if the slide moves to the mold touch position of the upper and lower molds. In addition, even when the workpiece has been thrown away from the fixed position of the lower mold, the operation progresses to the mold touch position of the upper and lower molds and the molding start of the workpiece may not be synchronized. Conceivable. Even in such a case, in the present invention, when the press slide moves to the die touch position of the upper and lower molds, press molding is all started. = YES is processed.

  One of the methods for determining whether or not the slide has started to move to the die touch position of the upper and lower molds is one of the press machine crank angle corresponding to the mold touch position of the upper and lower molds, or the press machine slide position. A method may be considered in which when a slide reaches the position, a relay or the like is driven to generate a signal, and when the signal is received, it is determined that press forming has started.

  Also, a method of determining the start of press molding by monitoring the signal output from the strain amount measuring means installed in the measurement target mold and corresponding to the mold touch position of the upper and lower molds when the output rises to a predetermined value. There is also.

  Press forming started? If NO is determined, is the determination operation 820 started press forming? The determination wait is continued until = YES.

  Processing operation 821: In the measurement of the mold strain amount, the strain amount of the mold is measured by a strain amount measuring means installed in the measurement target mold, for example, a strain gauge, a piezoelectric element, an FBG sensor using an optical fiber, or the like. .

  Judgment operation 822: Press forming completed? Then, it is determined whether or not press molding has been completed. Here, it is determined that the press molding is completed when the press machine slide reaches the molding bottom dead center position.

  As a method of determining the end of press molding, when the press machine crank angle reaches 180 degrees which is a general molding bottom dead center position, or the press machine slide position at the molding bottom dead center position is obtained in advance, and the position For example, when a slide arrives, a relay or the like is driven to generate a signal, and when the generation signal is received, it is possible to determine that press forming has ended.

  Alternatively, there is a method using information on molding speed measured separately. In this method, it is known that the press machine slide operates according to a sine curve, and if the molding speed at the start of press molding is known, the time at which press molding ends can be easily calculated. It is determined that the press forming is completed when the time when the press forming ends is reached. End of press molding? If NO is determined, is the determination operation 822 completed press forming? Processing operation 821 is repeated until = YES.

  Regarding the repeated cycles of the processing operation 821, defects such as cracks during press forming are generally a phenomenon that occurs in an extremely short time of about several ms, and therefore the repeated cycles are repeated at intervals of several ms or less. Is desirable. If there is no problem in the processing capability of the measuring device, it is desirable to measure at a sampling rate of 1 KHz or more.

  Judgment operation 823: Cracking or necking occurred? Then, as a result of determining the mold strain amount previously measured by the processing operation 821 based on the above-described determination method, the subsequent processing is distinguished depending on whether cracking or necking has occurred.

  In the case of press molding in which cracking and necking have occurred, the process proceeds to processing operation 824. If it is not press molding in which neither cracking nor necking has occurred, the process proceeds to determination operation 825.

  Judgment operation 825: Springback, inflow amount abnormality occurred? Then, as a result of determining the mold strain amount previously measured by the processing operation 821 based on the above-described determination method, the subsequent processing is distinguished depending on whether or not the springback or inflow amount abnormality has occurred. In the case of press forming in which spring back and inflow amount abnormality are occurring, the process proceeds to processing operation 826. If it is not press forming in which no springback or inflow amount abnormality has occurred, the process proceeds to determination operation 827.

  Judgment operation 827: Wrinkle generated? Then, as a result of determining the mold strain amount previously measured by the processing operation 821 based on the above-described determination method, the subsequent processing is distinguished depending on whether or not wrinkles are generated.

  In the case of press forming in which wrinkles are generated, the process proceeds to processing operation 828. If it is not press forming in which wrinkles are not generated, the process proceeds to processing operation 829.

  In the processing operation 824, when the Nth workpiece is formed during continuous production, it is determined that cracking or necking has occurred in the second step of forming the strain measuring means 702. In this case, the following commands are issued to each control means.

  The control unit 803 and the control unit 804 are instructed to set the molding speed of the Nth workpiece to zero. That is, the N-th workpiece is processed by the workpiece conveying device 602 on the third-step mold in which the control unit 803 is installed and the fourth-step mold in which the control unit 804 is installed. However, if it is determined that the Nth workpiece is cracked and necking has occurred in the molding of the second step, the molds of the third and fourth steps are activated. The Nth workpiece is not subjected to molding. By performing this processing operation 824, the following effects occur.

  First, since the Nth workpiece that has cracked does not undergo molding in the second and subsequent steps, the shape differs significantly from normal components that have undergone molding in all four steps, and can be mixed into normal components. The properties are extremely reduced. Even if it is mixed, it can be easily discovered because the shape is greatly different.

  In addition, since the N-th workpiece that has cracked is not subjected to molding after the second step, it becomes clear that the abnormal process in which the crack has occurred is the second step, and to avoid cracking. It is easy to examine measures.

  In addition, if trim processing in the third step is performed on the work material that has cracked, the trimmed waste part, that is, the shape of the trim scrap, is significantly different from that of a normal part. However, there was a problem that the shooter was clogged because it could not be discharged well.

  Since the N-th workpiece that has cracked is not subjected to the molding in the third step, it is possible to avoid troubles such as the above-described defective discharge of trim debris.

  In addition, when the fourth step of re-striking is performed on a work piece in which cracks have occurred, there is a problem in that the mold is damaged by burrs or the like generated in the crack portion of the work piece. Since the Nth workpiece to be cracked is not subjected to the molding in the fourth step, it is possible to avoid the trouble that the mold is damaged as described above.

Further, since N-th workpiece cracking occurs not subjected to molding in the second step and subsequent, operation energy transfer Puresu molding apparatus, that in particular to save power consumption, hydraulic, air pressure, etc. Can do.

  Processing operation 826 is that when forming the Nth workpiece during continuous production, spring back and inflow amount abnormality have occurred in the second step molding in which the strain measuring means 702 is installed. If it is determined, the following command is issued to each control means. The control unit 803 is not instructed to change molding conditions or the like. The control unit 804 is instructed to increase the molding load of the Nth workpiece by 10%.

  That is, when the N-th workpiece is transported by the workpiece transport device 602 to the third-step mold in which the control means 803 is installed, the N-th workpiece is formed in the second-step molding. Even if it is determined that a springback or inflow amount abnormality has occurred in the workpiece, the mold in the third step performs normal trim molding.

  Further, when the N-th workpiece is transported by the workpiece transport device 602 to the fourth-step mold in which the control means 804 is installed, the N-th workpiece is formed in the second-step molding. If it is determined that a springback or inflow abnormality has occurred in the workpiece, a command is given to increase the forming load by 10%. By performing this processing operation 826, the following effects occur.

  By increasing the forming load by 10%, the N-th workpiece that has a springback and is inferior in shape freezing is applied in the thickness direction of the product curved part such as the punch shoulder or in the in-plane direction of the product web surface. The applied compressive residual stress is increased, whereby the shape can be corrected.

  When the processing operation 828 determines that wrinkles are generated in the second step of forming the strain measuring means 702 when forming the Nth workpiece during continuous production, The following commands are given to each control means.

  The control unit 803 and the control unit 804 are instructed to set the molding speed of the Nth workpiece to zero. That is, the N-th workpiece is processed by the workpiece conveying device 602 on the third-step mold in which the control unit 803 is installed and the fourth-step mold in which the control unit 804 is installed. However, if it is determined that wrinkles are generated in the Nth workpiece in the molding of the second process, the molds of the third and fourth processes do not operate. The first workpiece is not molded. By performing this processing operation 828, the following effects occur.

  First, because the Nth workpiece that has been wrinkled does not undergo molding in the second and subsequent steps, the shape is significantly different from normal components that have undergone molding in all four steps and can be mixed into normal components. The properties are extremely reduced. Even if it is mixed, it can be easily discovered because the shape is greatly different.

  In addition, since the N-th workpiece with wrinkles is not subjected to molding after the second step, it is clear that the abnormal step in which wrinkles have occurred is the second step, so as to avoid wrinkles. It is easy to examine measures.

  In addition, when trimming in the third step is performed on the work material in which wrinkles are generated, the trimmed waste part, that is, the shape of the trim waste is greatly different from that of a normal part. However, there was a problem that the shooter was clogged because it could not be discharged well. Since the Nth work material in which wrinkles are generated does not receive the molding in the third step, it is possible to avoid troubles such as the above-described defective discharge of trim debris.

  Further, when the fourth step of re-striking is performed on the workpiece on which wrinkles are generated, there is a problem that the mold is damaged by the wrinkles of the workpiece. Since the Nth work material in which wrinkles are generated is not subjected to the molding in the fourth step, it is possible to avoid the trouble that the mold is damaged as described above.

Further, since wrinkles N th workpiece generated do not undergo the forming of the second step and subsequent, operation energy transfer Puresu molding apparatus, that in particular to save power consumption, hydraulic, air pressure, etc. Can do.

The processing operation 829 is a process in the case where it is determined that there is no molding defect in any of the determination operation 823, the determination operation 825, and the determination operation 827, and the control unit 803 and the control unit 804 change the molding conditions and the like. No order is given.
(Immediate)
Hereinafter, the present invention is the suppression of molding defects phenomena during press molding using a transfer Puresu forming apparatus, the suppression of the production defect occurs, the operation energy savings during production, it is a preferred technique etc, other methods Compared with

  As a means for determining the occurrence of molding defect phenomena such as cracks, wrinkles, and springback, not only the technique using the strain measuring means 702 of the present invention, but also photographing a workpiece with various imaging devices such as a high-speed camera and an infrared camera. It is possible to use a technique such as.

  If a technique for photographing a workpiece using various imaging devices is used as, for example, an alternative technique of the strain measuring means 702 in FIG. 1 of the present invention, the various imaging devices are configured to move the workpiece by relative movement of the die 202 and the punch 102. Imaging is impossible only after the die 202 is raised after the processing is completed and the workpiece enters the field of view of various imaging devices.

However, in many of the transfer Puresu molding apparatus is clamped by a workpiece transport device 602 before the workpiece enters the field of view of the imaging device, thereby being transported to the next step. The middle line of the transfer Puresu molding apparatus continues movement always workpiece, it is hardly to be stationary. Even if you try to shoot a workpiece that does not remain stationary with various imaging devices, it is difficult to focus, and it is difficult to recognize the workpiece that has entered the field of view, that is, to recognize the outer shape of the workpiece. There is a problem, the workpiece captured in the middle line of the transfer Puresu molding apparatus was not possible.

As described in the present invention, the transfer Puresu I palm cracking in the middle line of the molding device, to determine the occurrence of molding defects phenomena such springback, the control means 803 further halfway line, forming speed and molding using the control means 804 By controlling the molding conditions such as the load, in order to obtain the effects of suppressing the defective shape phenomenon, suppressing the production failure, and saving the operating energy during production, from the start of press molding as described in the flowchart of FIG. A means capable of performing measurement before the end of press forming is indispensable, and the strain measuring means 702 is a very suitable means as the means.

For these reasons, the present invention is the suppression of molding defects phenomena during press molding using a transfer Puresu molding apparatus, production defect occurrence suppression, operating energy savings in production, a preferred technique like.

  Next, the invention described in (2) will be described with reference to FIG. In FIG. 8, a wrinkle pressing mold 301, a wrinkle pressing mold 302, a pad 402, and a pad 403 are added to FIG. About the point other than this, it is the structure similar to FIG. 1 regarding the invention as described in (1).

  Based on the above-mentioned invention, the press molding apparatus shown in FIG.

  Table 1 shows the characteristics of the steel sheet used as the workpiece. A steel plate having a plate thickness of 1.8 mm and a tensile strength of 590 MPa was used.

試作したトランスファープレス成形装置を用いて成形した部品形状を図９に示す。本部材は図９断面図Ａ−Ａに示すようなハット状断面を有する部品である。

The molded part shape with a transfer Puresu molding apparatus prototype shown in Fig. This member is a component having a hat-shaped cross section as shown in FIG.

  In this molding, both punches and dies were selected as measurement target molds, and two strain measuring means 702 were installed, one for the punch 102 and one for the die 202, as shown in FIG.

  Both of the two strain measuring means 702 were installed so as to be located on the pressing direction side indicated by the arrow from the die shoulder R stop on the material outflow side when the punch 102 and the die 202 were at the bottom dead center position. .

  As shown in FIG. 5a, the strain measuring means 702 has a hole that does not penetrate the die and cuts an internal thread, and a strain sensor 902 as shown in FIG. A method of press-fitting with force was used.

  A piezoelectric element sensor was used as the strain sensor 902. The direction of compression / tensile strain measured by the piezoelectric element sensor was the same as the press direction.

  The amount of strain measured by the strain measuring means 702 installed as described above is plotted in the graph shown in FIG. Then, the mold abnormality or the molding abnormality is determined depending on whether or not the strain amount is within a predetermined range (a range between the upper limit G1 and the lower limit G2) already shown in FIG. .

  In this molded member, the stroke when the molding of the workpiece 502 is started is 0 mm, and the stroke when the molding is completed is 105 mm. The average strain amount G3 for determining the molding abnormality shown in the figure is the strain measuring means 702 in 75 press moldings in which the molded product is confirmed to be normal by first performing 100 press moldings. This is obtained by averaging the strain amount obtained by the above.

  In addition, in the above-described 100 times of press forming, the amount of strain at the time of press forming having an abnormality in the molded product was collected, and 11 pieces of strain amount data exceeding the average strain amount were obtained. The strain amount converted into the upper limit G1 of the strain amount predetermined range. The upper limit of the predetermined strain amount range was almost equal to the average strain amount G3 plus 100 με over the entire stroke range.

  In addition, in the above-described 100 times of press forming, the amount of strain at the time of press forming in which there is an abnormality in the molded product was collected, and 14 pieces of strain amount data below the average strain amount G3 were obtained. The strain amount averaged was taken as the lower limit G2 of the strain amount predetermined range. The lower limit G2 of the predetermined strain amount range was almost equal to the average strain amount G3 obtained by subtracting 80 με over the entire stroke range.

Table 2 and Table 3 shows the press-molded test results using the transfer Puresu forming apparatus fabricated as the invention example 1.

表２には、割れやスプリングバックなどの製品異常を検出するために行った製品検査結果と、ダイ２０２に設置した歪測定手段７０２により得られたひずみ量による製品異常判定結果を示している。歪測定手段７０２によって、異常率６．２３％のうち、異常判定率６．２０％の異常を判定することができた。また、異常過検知率は０．２６％、異常見逃し率は０．０４％であった。

Table 2 shows the result of product inspection performed to detect product abnormalities such as cracks and springback, and the result of product abnormality determination based on the amount of strain obtained by the strain measuring means 702 installed on the die 202. The strain measuring means 702 was able to determine an abnormality with an abnormality determination rate of 6.20% out of an abnormality rate of 6.23%. The abnormal overdetection rate was 0.26%, and the abnormal oversight rate was 0.04%.

表３にも、上述と同様に、割れやしわなどの製品異常を検出するために行った製品検査結果と、ポンチ１０２に設置した歪測定手段７０２により得られたひずみ量による製品異常判定結果を示している。歪測定手段７０２によって、異常率５．６５％のうち、異常判定率５．５４％の異常を判定することができた。また、異常過検知率は０．９２％、異常見逃し率は０．１１％であった。

Similarly to the above, Table 3 also shows the results of product inspections performed to detect product abnormalities such as cracks and wrinkles, and the product abnormality determination results based on the strain amount obtained by the strain measuring means 702 installed in the punch 102. Show. The strain measuring means 702 was able to determine an abnormality with an abnormality determination rate of 5.54% out of an abnormality rate of 5.65%. The abnormal overdetection rate was 0.92%, and the abnormal oversight rate was 0.11%.

  In the press molding of Example 1 of the present invention, the parts having molding defects such as cracks, wrinkles, and necking are not molded after the second process, so the shape is larger than the normal parts subjected to all the moldings in the fourth process. Unlikely, the possibility of mixing in normal parts is extremely reduced.

  In the press molding not using the present invention, the ratio of the part in which the molding defect occurred to the normal part was 335 ppm, but in the press molding of the present invention example 1, the part in which the molding defect has occurred is greatly different in shape and easy. As a result, it was not possible to mix in normal parts. It was also possible to clarify that the process in which molding defects occurred was the second process.

  In press molding that does not use the present invention, when trim molding in the third step is performed on a part in which molding defects such as cracks and wrinkles have occurred, the trimmed and discarded part, that is, the shape of the trim scraps is normal part. Since it was very different from the case, there was a problem that trim waste could not be discharged well and the shooter was clogged. In the press molding of Example 1 of the present invention, a part in which a molding defect has occurred is not subjected to the molding in the third step, so that it is possible to avoid troubles such as the above-described defective trim dust discharge.

  In the press molding not using the present invention, the ratio of clogging the shooter due to trim molding of the part in which molding failure occurred in the third step was 221 ppm. Since the defective part is not subjected to the molding in the third step, troubles such as defective trim dust discharge did not occur.

  In press molding that does not use the present invention, if the re-striking process in the fourth step is performed on a part in which molding defects such as cracks and wrinkles have occurred, the mold may be damaged by burrs or wrinkles generated in the cracked part of the part. There was a problem of doing. In the press molding of Example 1 of the present invention, a part in which molding failure has occurred is not subjected to the molding in the fourth step, so that it is possible to avoid the trouble that the mold is damaged as described above.

  In the press molding not using the present invention, the ratio of damage to the mold due to the rest-like molding of the part in which molding failure occurred in the fourth step was 75 ppm. Then, since the part in which the molding defect occurred was not subjected to the molding in the fourth step, troubles such as damage to the mold did not occur.

In press molding that does not use the present invention, molding is performed in all steps even on parts that have undergone molding defects such as cracks, wrinkles, and necking. However, the press molding of Example 1 of the present invention has molding defects such as cracks, wrinkles, and necking. since the generated parts not subjected to molding in the second step and subsequent, operation energy transfer Puresu molding apparatus, in particular it is possible to save power consumption, hydraulic, air pressure, etc..

  As shown in Tables 2 and 3, in Example 1 of the present invention, the occurrence rate of cracks, wrinkles, and necking is 6.7%, and these parts are not subjected to the molding after the second step, so the power consumption Both the hydraulic pressure and the air pressure can save 3.5% of energy consumption.

  In Example 1 of the present invention, by increasing the molding load by 10% at the time of molding in the fourth process mold for parts with molding defects such as springback and inflow abnormality, the thickness direction of the curved part of the product such as punch shoulder Alternatively, the compressive residual stress applied in the in-plane direction of the product web surface can be increased, thereby correcting the shape.

In press molding without using the present invention, the ratio of occurrence of molding defects such as springback and inflow abnormality was 5.1%. As shown in Tables 2 and 3, 5.1% of molding defects such as springback and inflow amount abnormality were detected in Example 1 of the present invention, but these parts were molded at the time of molding in the fourth step mold. Since the shape could be corrected by increasing the load by 10%, these 5.1% parts could also be used as normal products. That is, in the exit side of the transfer Puresu molding apparatus could be as a result spring-back, the incidence of defective molding such as flow rate abnormality to zero.

  Based on the above-mentioned invention, the press molding apparatus shown in FIG.

  The characteristics of the steel sheet used as the workpiece in Table 1 are the same as those shown in Table 1. A steel plate having a plate thickness of 1.8 mm and a tensile strength of 590 MPa was used.

The molded part shape with a transfer Puresu molding apparatus prototype shown in Figure 12. This member is a drawn part having a cross section as shown in FIG. 12 cross sectional view AA or cross section BB.

  In this molding, both punches and dies were selected as the measurement target molds, and two strain measuring means 702 were installed, one for the punch 102 and one for the die 202, as shown in FIG.

  Both of the two strain measuring means 702 were installed so as to be located on the pressing direction side indicated by the arrow from the die shoulder R stop on the material outflow side when the punch 102 and the die 202 were at the bottom dead center position. .

  As shown in FIG. 5a, the strain measuring means 702 has a hole that does not penetrate the die and cuts an internal thread, and a strain sensor 902 as shown in FIG. A method of press-fitting with force was used.

  A piezoelectric element sensor was used as the strain sensor 902. The direction of compression / tensile strain measured by the piezoelectric element sensor was the same as the press direction.

  The amount of strain measured by the strain measuring means 702 installed as described above is plotted in the graph shown in FIG. Then, the mold abnormality and the molding abnormality are determined depending on whether or not they are within the predetermined strain amount range (a range between the upper limit G4 and the lower limit G5) for determining the molding abnormality already shown in FIG. .

  In this molded member, the stroke when the molding of the workpiece 502 is started is 0 mm, and the stroke when the molding is completed is 105 mm. The average strain amount G6 for determining the molding abnormality shown in the figure is the strain measuring means 702 in the 75 press moldings in which 100 times of press molding is first performed and it is confirmed that there is no abnormality in the molded product. This is obtained by averaging the strain amount obtained by the above.

  In addition, in the above-described 100 times of press forming, the amount of strain at the time of press forming having an abnormality in the molded product was collected, and 11 pieces of strain amount data exceeding the average strain amount were obtained. The strain amount converted into the upper limit G4 of the strain amount predetermined range. The upper limit of the predetermined strain amount range was almost equal to the average strain amount G6 plus 100 με over the entire stroke range.

  In addition, in the above-described 100 times of press forming, the amount of strain at the time of press forming having an abnormality in the molded product was collected, and 14 pieces of strain amount data below the average strain amount G6 were obtained. The strain amount averaged was taken as the lower limit G5 of the strain amount predetermined range. The lower limit G5 of the predetermined strain amount range was almost equal to the average strain amount G6 obtained by subtracting 80 με over the entire stroke range.

Table 4 and Table 5 shows the press-molded test results using the transfer Puresu forming apparatus fabricated as Example 2 of the present invention.

表４には、割れやスプリングバックなどの製品異常を検出するために行った製品検査結果と、ダイ２０２に設置した歪測定手段７０２により得られたひずみ量による製品異常判定結果を示している。歪測定手段７０２によって、異常率６．２３％のうち、異常判定率６．２３％の異常を判定することができた。また、異常過検知率は０．０３％、異常見逃し率は０．００％であった。

Table 4 shows the result of product inspection performed to detect product abnormality such as cracks and springback, and the result of product abnormality determination based on the amount of strain obtained by the strain measuring means 702 installed on the die 202. The strain measuring means 702 was able to determine an abnormality with an abnormality determination rate of 6.23% out of the abnormality rate of 6.23%. The abnormal overdetection rate was 0.03%, and the abnormal oversight rate was 0.00%.

表５にも、上述と同様に、割れやしわなどの製品異常を検出するために行った製品検査結果と、ポンチ１０２に設置した歪測定手段７０２により得られたひずみ量による製品異常判定結果を示している。歪測定手段７０２によって、異常率５．６５％のうち、異常判定率５．６５％の異常を判定することができた。また、異常過検知率は０．０４％、異常見逃し率は０．００％であった。

Similarly to the above, Table 5 also shows the results of product inspections performed to detect product abnormalities such as cracks and wrinkles, and the product abnormality determination results based on the amount of strain obtained by the strain measuring means 702 installed in the punch 102. Show. The strain measuring means 702 was able to determine an abnormality with an abnormality determination rate of 5.65% out of the abnormality rate of 5.65%. The abnormal overdetection rate was 0.04%, and the abnormal oversight rate was 0.00%.

  In the press molding of Example 2 of the present invention, the parts with molding defects such as cracks, wrinkles, and necking are not molded after the second process, so the shape is larger than the normal parts subjected to all the moldings in the fourth process. Unlikely, the possibility of mixing in normal parts is extremely reduced.

  In the press molding not using the present invention, the ratio of the part in which the molding defect occurred to the normal part was 335 ppm. However, in the press molding of the present invention example 2, the part in which the molding defect has occurred is greatly different in shape and easy. As a result, it was not possible to mix in normal parts.

  It was also possible to clarify that the process in which molding defects occurred was the second process. In press molding that does not use the present invention, when trim molding in the third step is performed on a part in which molding defects such as cracks and wrinkles have occurred, the trimmed and discarded part, that is, the shape of the trim scraps is the normal part. Since it was very different from the case, there was a problem that trim waste could not be discharged well and the shooter was clogged. In the press molding of Example 2 of the present invention, a part in which a molding defect has occurred is not subjected to the molding in the third step, so that it is possible to avoid troubles such as the above-described defective trim dust discharge.

  In the press molding not using the present invention, the ratio of clogging the shooter due to trim molding of the part in which molding failure occurred in the third step was 221 ppm. Since the defective part is not subjected to the molding in the third step, troubles such as defective trim dust discharge did not occur.

  In press molding that does not use the present invention, if the re-striking process in the fourth step is performed on a part in which molding defects such as cracks and wrinkles have occurred, the mold may be damaged by burrs or wrinkles generated in the cracked part of the part. There was a problem of doing. In the press molding of Example 2 of the present invention, since the part in which the molding failure has occurred is not subjected to the molding in the fourth step, it is possible to avoid the trouble that the mold is damaged as described above.

  In the press molding not using the present invention, the ratio of damage to the mold due to the rest-like molding of the part in which molding failure occurred in the fourth step was 75 ppm. Then, since the part in which the molding defect occurred was not subjected to the molding in the fourth step, troubles such as damage to the mold did not occur.

In press molding that does not use the present invention, molding is performed in all steps even on parts that have undergone molding defects such as cracks, wrinkles, and necking. However, the press molding of Example 2 of the present invention has molding defects such as cracks, wrinkles, and necking. since the generated parts not subjected to molding in the second step and subsequent, operation energy transfer Puresu molding apparatus, in particular it is possible to save power consumption, hydraulic, air pressure, etc..

  As shown in Tables 4 and 5, in the present invention example 2, the occurrence rate of cracks, wrinkles and necking is 6.7%, and these parts are not subjected to the molding after the second step. Both the hydraulic pressure and the air pressure can save 3.5% of energy consumption.

  In Example 2 of the present invention, by increasing the molding load by 10% at the time of molding in the fourth process mold for the parts with molding defects such as springback and inflow abnormality, the thickness direction of the curved part of the product such as the punch shoulder is increased. Alternatively, the compressive residual stress applied in the in-plane direction of the product web surface can be increased, thereby correcting the shape.

In press molding without using the present invention, the ratio of occurrence of molding defects such as springback and inflow abnormality was 5.1%. As shown in Tables 4 and 5, 5.1% of molding defects such as springback and inflow abnormality were detected in Example 2 of the present invention, but these parts were molded at the time of molding in the fourth process mold. Since the shape could be corrected by increasing the load by 10%, these 5.1% parts could also be used as normal products. That is, in the exit side of the transfer Puresu molding apparatus could be as a result spring-back, the incidence of defective molding such as flow rate abnormality to zero.

101: punch, first process mold 102: punch, second process mold 103: punch, third process mold 104: punch, fourth process mold 201: die, first process mold 202: die, 2 Process mold 203: Die, 3rd process mold 204: Die, 4th process mold 301: Wrinkle holding mold, 1st process mold 302: Wrinkle holding mold, 2nd process mold 402: Pad, 2nd step mold 403: Pad, 3rd step mold 500: Work material, Before processing 501: Work material, 1st process right before 502: Work material, 2nd process just before 503: Work material, 3 step th processing just before 504: workpiece, 4 step th processing just before 505: workpiece, 4 step th processed-601: workpiece transfer apparatus, the transfer Puresu molding apparatus inlet side 602: workpiece transfer apparatus, the transfer Puresu molding device process between 603: the pressure Material transfer apparatus, the transfer Puresu molding apparatus outlet side 604: finger rail 605: finger 702: strain measuring means, second step first mold 803: control unit, 3 steps th mold 804: control means, 4 step th Mold 901: Nest guide 902: Strain sensor

Claims (3)

A plurality of molds for forming a workpiece by relative movement of a punch and a die, and a workpiece conveying device for conveying the workpiece between the plurality of molds, the plurality of molds A transfer press molding apparatus that sequentially molds the workpiece.
The first mold to be molded first is placed inside the measurement target mold when at least one of the punch and the die is a measurement target mold, and is measured according to the stroke during press molding. A strain measuring means for measuring the elastic strain generated inside the target mold, and a molding abnormality predicting means for predicting a molding abnormality when the elastic strain exceeds a predetermined range or falls below a predetermined range , The second mold that is installed after the first mold and corrects the shape of the workpiece is a control unit that controls at least one of the press load and the molding speed based on the prediction result of the molding abnormality. The transfer press molding apparatus characterized by having.   2. The transfer press molding according to claim 1, wherein the first die has at least one of a pad and a crease presser die that interlock with relative movement of the punch and the die. apparatus.   The transfer press molding apparatus according to claim 1 or 2, wherein the strain measuring means is a piezoelectric element or a strain gauge.

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