The present invention relates to a method for manufacturing a press-molded product and a press line.
Background technology
[0002]
In press molding, there is a technology to improve the dimensional accuracy of press molded products by making a part of the mold movable. For example, Japanese Patent No. 6179696 (Patent Document 1) discloses a press device including a die provided with a die pad and a punch arranged opposite to the die and provided with an inner pad. There is.
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent No. 6179696
Outline of the invention
Problems to be solved by the invention
[0004]
In press molding, all plate materials in the same production lot are press molded under preset press conditions. That is, if the deviation of the shape of the first press-molded product from the target shape is within the tolerance, the subsequent press molding is also performed under the same press conditions as the press conditions of the first press-molded product.
[0005]
The inventors have found that when the characteristics of a plurality of plate materials vary, even if the shape of the press-molded product first press-molded is the desired shape, the press-molded product to be press-molded later does not have the desired shape. I noticed that there is.
[0006]
Therefore, an object of the present invention is to provide a method for manufacturing a press-molded product and a press line that can reduce deviations or variations in the shapes of a plurality of press-molded products from the target shape.
Means to solve problems
[0007]
The method for producing a press-molded product according to an embodiment of the present invention is to obtain the plate thickness of one or a plurality of plate materials to be pressed individually for each plate material, and to obtain a die, a punch, and both the die and the punch. It includes press-molding the plate material into a press-molded product by a movable die whose relative position can be changed with respect to the above. In the press molding, the initial position of the movable die with respect to the die or the punch is controlled based on the plate thickness of the plate material.
The invention's effect
[0008]
According to the embodiment of the present invention, it is possible to reduce the deviation or variation of the shapes of a plurality of press-molded products from the target shape.
A brief description of the drawing
[0009]
[Fig. 1] Fig. 1 is a diagram showing a configuration example of a press line in the present embodiment.
FIG. 2 is a perspective view showing a configuration example of a press device having a movable die.
[Fig. 3A] It is a figure which shows the arrangement example of a punch and a plate material.
[Fig. 3B] Fig. 3B is a diagram showing a measurement position of a plate thickness and an arrangement example of an inner pad on a punch side when a plate material includes a thick portion and a thin portion.
FIG. 4A is a diagram showing an example of press molding.
[FIG. 4B] FIG. 4B is a diagram showing an example of press molding.
[Fig. 4C] It is a figure which shows the example of press molding.
[Fig. 4D] It is a figure which shows the example of press molding.
FIG. 5 is a cross-sectional view showing an example of a press-molded product.
[Fig. 6] Fig. 6 is a flow chart showing an operation example of the controller.
[Fig. 7] Fig. 7 is a graph showing an example of the correlation between the amount of protrusion of a moving part and the shape of a press-molded product.
[Fig. 8] Fig. 8 is a graph showing an example of the relationship between the appropriate protrusion amount of a movable part and the plate thickness.
FIG. 9 is a graph showing the plate thickness, the amount of protrusion, and the position accuracy of the flange when feedforward control based on the plate thickness is not performed.
FIG. 10 is a graph showing the plate thickness, the amount of protrusion, and the position accuracy of the flange when feedforward control is performed based on the plate thickness.
Embodiment for carrying out the invention
[0010]
The inventors recognized that when the plate thicknesses of a plurality of plate materials are slightly different, the shapes of a plurality of press-molded products formed by press-molding the plurality of plate materials may also be slightly different. Therefore, we investigated a method to suppress the variation in the shape of the press-molded product due to the variation in the plate thickness of a plurality of plate materials. As a result of diligent studies, we came up with the idea that by controlling the relative position of the movable die with respect to the die or punch based on the plate thickness, it is possible to suppress variations in the shape of the press-molded product due to variations in plate thickness. .. Based on this finding, we came up with the following embodiments.
[0011]
(Method 1)
The method for producing a press-molded product according to an embodiment of the present invention is to obtain the plate thickness of one or a plurality of plate materials to be pressed individually for each plate material, and to obtain a die, a punch, and both the die and the punch. It includes press-molding the plate material into a press-molded product by a movable die whose relative position can be changed with respect to the above. In the press molding, the initial position of the movable die with respect to the die or the punch is controlled based on the plate thickness of the plate material.
[0012]
According to the above manufacturing method, the initial position of the movable die at the time of press molding with respect to the die or punch is controlled according to the plate thickness of the plate material. By controlling this initial position, the shape of the press-molded product is adjusted according to the plate thickness of the plate material. Therefore, it is possible to suppress deviation or variation in the shape of the plurality of press-molded products from the target shape due to the variation in the plate thickness of the plurality of plate materials. The plate material to be pressed may be, for example, a blank which is a flat plate, or an intermediate molded product obtained by molding the blank.
[0013]
As an example, the punch includes a convex portion that protrudes toward the die. The die includes a recess corresponding to the protrusion of the punch. The movable die is provided, for example, in at least one of the convex portion of the punch and the concave portion of the die. The first inner pad, which is an example of the movable mold, is provided on the top of the convex portion of the punch. The first inner pad is provided so as to be able to project from the top of the punch toward the die and to be housed in the top of the punch. A die pad, which is an example of a movable mold, is provided at the bottom of a recess of the die. The die pad is provided so as to project from the bottom of the recess of the die toward the punch.
[0014]
The initial position of the movable die is the relative position of the movable die with respect to the die or punch at the initial stage of each of the plurality of press moldings. In each press molding, the press molding is performed by bringing the die and the punch relatively close to each other from the state where the movable die at the initial position is in contact with the plate material. The initial position of the movable mold is the position of the movable mold before the operation of bringing the die and the punch relatively close to each other.
[0015]
For example, the movable die may come into contact with a portion of the press-molded product (finished product) during press molding. In this case, the movable die controls the shape of the press-molded product (finished product). The initial position of the movable die can control the delicate shape of the product part of the press-molded product.
[0016]
The movable die may move relative to the die or punch during one press molding. Examples of possible dies of this type include punch pads (inner pads), die pads, blank holders, and the like. Alternatively, the movable die may be one in which the relative position with respect to the die or punch is fixed during one press molding. That is, the movable die may be one that does not move (do not operate) with respect to the die or punch during one press molding. It should be noted that one press molding is a press molding performed by a set of a set of a die, a punch and a movable die in order to make one press-molded product.
[0017]
(Method 2)
In the above method 1, the press molding may include continuously press molding a plurality of plate materials. In at least one of a plurality of continuous press moldings, the initial position of the movable die with respect to the die or the punch may be controlled based on the plate thickness of the plate material. As a result, in a plurality of press-molded products produced by a plurality of continuous press moldings, it is possible to suppress variations in the shape of the press-molded products due to variations in plate thickness.
[0018]
(Method 3)
In the above method 1 or 2, the acquisition of the plate thickness may include acquiring the plate thickness at a plurality of positions of one plate material. In the press molding of the one plate thickness, the initial position of the movable die with respect to the die or the punch may be controlled based on the plate thickness at a plurality of positions of the one plate material. Thereby, the difference in the plate thickness in one plate material can be reflected in the initial position of the movable mold. Therefore, it is possible to suppress deviation and variation from the target shape of the press-molded product due to the difference in plate thickness in one plate.
[0019]
(Method 4)
In the above method 3, the movable mold may include a plurality of movable mold portions whose positions can be changed independently of each other. The acquisition of the plate thickness may include acquiring the plate thickness at a plurality of positions corresponding to the plurality of movable mold portions of one plate material. In the press molding of the one plate thickness, the initial position of each of the plurality of movable dies may be controlled based on the plate thickness of the corresponding position among the plurality of positions of the one plate material. good. Thereby, the initial position of the movable mold portion corresponding to the position where the plate thickness is acquired can be controlled based on the plate thickness. Therefore, the difference in plate thickness in one plate can be reflected in the movable mold more finely.
[0020]
(Method 5)
In any of the above methods 1 to 4, in the press molding, the die may slide with the portion where the plate thickness of the plate material is measured. The inventors have found that the thickness of the portion of the plate that slides with the die during press molding tends to affect the shape of the press-molded product. In the above method 2, the plate thickness of the portion of the plate material that slides on the die can be measured, and the initial position of the movable mold can be controlled based on the measured plate thickness. As a result, the initial position of the movable die is controlled based on the plate thickness of the portion that easily affects the shape of the press-molded product. Therefore, it is possible to further suppress variations in the shapes of a plurality of press-molded products.
[0021]
(Method 6)
In the above method 5, the movable mold may include a first inner pad provided at the top of the punch. In the press molding, there may be a portion where the plate thickness of the plate material is measured, which is perpendicular to the ridgeline of the punch shoulder of the punch and in the cross section including the first inner pad.
[0022]
According to the above method 5, the allowance from the punch of the first inner pad can be controlled based on the plate thickness of the plate material portion that is more likely to affect the shape of the press-molded product. Therefore, it is possible to further suppress variations in the shapes of a plurality of press-molded products.
[0023]
(Method 7)
In the above method 5, the movable mold may include a first inner pad and a second inner pad provided on the top of the punch. The plate material may be a differential thickness metal plate provided with a thick portion and a thin portion having a thickness thinner than the thick portion. The acquisition of the plate thickness of the plate material may include the acquisition of the plate thickness of the thick portion and the plate thickness of the thin portion. In the press molding, there is a portion perpendicular to the ridgeline of the punch shoulder of the punch and in the cross section including the first inner pad, the plate thickness of the thick portion is obtained, and in the press molding, the punch shoulder is obtained. In the cross section including the second inner pad, which is perpendicular to the ridgeline of the above, there may be a portion where the plate thickness of the thin-walled portion is obtained. In this case, in the press molding, the initial position of the first inner pad with respect to the punch is controlled based on the plate thickness of the thick portion, and the punch of the second inner pad is controlled based on the plate thickness of the thin portion. The initial position with respect to can be controlled.
[0024]
According to the above method 4, in the press molding of a plate material having a thick portion and a thin wall portion, the first inner pad and the second inner pad are based on the plate thickness of the plate material portion which is more likely to affect the shape of the press-molded product. The initial position with respect to the punch can be controlled.
[0025]
(Method 8)
In the above method 5, the movable mold may include a first inner pad and a second inner pad provided on the top of the punch. The plate material may include a high-strength portion and a low-strength portion having a lower strength than the high-strength portion. The acquisition of the plate thickness of the plate material may include the acquisition of the plate thickness of the high-strength portion and the plate thickness of the low-strength portion. In the press molding, there is a portion perpendicular to the ridgeline of the punch shoulder of the punch and in the cross section including the first inner pad, where the plate thickness of the high-strength portion is obtained, and in the press molding, the punch shoulder is obtained. There may be a portion where the plate thickness of the low-strength portion is obtained in the cross section including the second inner pad, which is perpendicular to the ridgeline of the above. In this case, in the press molding, the initial position of the first inner pad with respect to the punch is based on the plate thickness of the high-strength portion. The initial position of the second inner pad with respect to the punch can be controlled based on the plate thickness of the low-strength portion.
[0026]
According to the above method 5, in the press molding of a plate material having a high-strength portion and a low-strength portion, the first inner pad and the second inner pad are based on the plate thickness of the plate material portion that is more likely to affect the shape of the press-molded product. You can control the initial position of the punch with respect to the punch.
[0027]
(Method 9)
In any of the above methods 1 to 8, in the press molding, the die and the punch are relatively close to each other in a state where the relative position of the movable die with respect to the die or the punch is fixed at the initial position. A first press step of press-molding the plate material and a second press step of press-molding the plate material by bringing the die and the punch relatively close to each other while accommodating the movable die in the die or the punch. It may be included. In the press molding, the initial position of the movable die may be controlled based on the plate thickness of the plate material.
[0028]
The inventors have fixed the position of the movable die relative to the die or the punch to the initial position, and the initial position of the movable die in the first pressing step of pressing the plate material with the die and the punch relatively close to each other. However, it was found that the shape of the press-molded product had more influence. In the above method 9, the initial position of the movable die in the first pressing step can be controlled according to the plate thickness of the plate material. This makes it possible to further suppress variations in the shapes of a plurality of press-molded products.
[0029]
In the above method 9, in at least one of the first pressing step and the second pressing step, the die may be slid with the portion where the plate thickness of the plate material is acquired. As a result, the initial position of the movable die is controlled based on the plate thickness of the portion that easily affects the shape of the press-molded product.
[0030]
In any of the above methods 1 to 9, the initial position of the movable die controlled based on the plate thickness of the plate material is, for example, the punch of the first inner pad and / or the second inner pad provided at the top of the punch. It may be used as a payout from. This allowance may be, for example, the amount of protrusion of the first inner pad and / or the second inner pad with respect to the punch. As a result, it is possible to efficiently suppress variations in the shapes of a plurality of press-molded products.
[0031]
(Method 10)
In any of the above methods 1 to 9, the tensile strength of the portion having the highest strength in the plate material may be 980 MPa or more. It has been found by the inventors that when the plate material has a high strength of 980 MPa or more, the variation in the plate thickness may be larger than in the case of a low strength. By applying any of the above methods 1 to 9 to a plate material having a strength of 980 MPa or more, it is possible to suppress deviation or variation from the target shape of the press-molded product in press molding of such a high-strength plate material. .. The plate material can be a metal plate. As an example, the plate material may be a steel plate.
[0032]
In another method of manufacturing a press-molded product according to another embodiment of the present invention, the plate material is pressed into the press-molded product by measuring the plate thickness of the plate material to be pressed and by punching a die and a punch provided with a first inner pad on the top. Including molding. In the press molding, the allowance for ejecting the first inner pad from the punch is controlled based on the plate thickness of the plate material.
[0033]
(Structure 1)
The press line in the embodiment of the present invention is for a plate thickness acquisition device that individually acquires the plate thickness of one or a plurality of plate materials to be pressed for each plate material, and for both a die, a punch, the punch, and the die. It includes a press device having a movable mold that can be moved relative to each other, and a controller that controls the press device. In the press molding of the plate material by the die, the punch and the mold, the controller is an initial position of the movable mold with respect to the die or the punch based on the plate thickness of the plate material acquired by the plate thickness acquisition device. To control.
[0034]
According to the above configuration 1, the initial position of the movable die with respect to the die or punch at the time of press forming of each plate material is controlled according to the plate thickness of each plate material. By controlling this initial position, the shape of the press-molded product is adjusted according to the plate thickness of the plate material. Therefore, it is possible to suppress deviation or variation in the shape of the plurality of press-molded products from the target shape due to the variation in the plate thickness of the plurality of plate materials.
[0035]
(Structure 2)
In the above configuration 1, the plate thickness acquisition unit may be a plate thickness measuring device for measuring the plate thickness of the plate material. As a result, it is possible to efficiently obtain the individual plate thickness of the plate material to be pressed.
[0036]
(Structure 3)
In the above configuration 2, the plate thickness measuring point by the plate thickness measuring device may be perpendicular to the ridgeline of the punch shoulder of the punch and may be in the plane including the movable die. This makes it possible to control the initial position of the movable mold corresponding to the location where the plate thickness is measured.
[0037]
(Structure 4)
The press line in the embodiment of the present invention includes a die, a punch, a press device provided with a movable mold that can move relative to both the die and the punch, a plate thickness measuring device, and the plate thickness measurement. It includes a transport device capable of transporting a plate material to be pressed from the device to the press device, and a plate thickness measuring device and a controller connected to the press device. The movable mold and the plate thickness measuring device are arranged on a line parallel to the transport direction of the transport device.
[0038]
In the above configuration 4, the movable mold and the plate thickness measuring device are arranged on a line parallel to the transport direction, that is, the position of the plate material measured by the plate thickness measuring device and the movable mold. It means that they are lined up on a line parallel to the transport direction. With this configuration, it is possible to measure the plate thickness in the region of the plate material extending in the transport direction from the portion of the plate material in contact with the movable die in the press molding by the press device. Since the controller is connected to the plate thickness measuring device and the press device, the plate thickness measured by the plate thickness measuring device can be used to control the initial position of the movable die with respect to the die or punch in the press forming of the press device. The initial position of the movable die in press molding can be controlled based on the plate thickness of the plate material that tends to affect the shape of the press-molded product. Therefore, it is possible to suppress deviation or variation in the shape of the plurality of press-molded products from the target shape due to the variation in the plate thickness of the plurality of plate materials.
[0039]
The plate thickness measuring device is configured to be able to measure the plate thickness of the plate material transported upstream of the press device. The controller controls the initial position of the movable die with respect to the die or punch when the plate material is press-molded based on the plate material thickness measured by the plate thickness measuring device. For example, the controller sets the initial position when the plate material is press-formed by bringing the die and the punch relatively close to each other with the position (for example, the amount of protrusion) relative to the die or punch of the movable die fixed at the initial position. , May be determined based on the plate thickness.
[0040]
The controller may have a processor and a storage device. The processor executes the program stored in the storage device. The program is a program that causes the processor to execute a process of controlling the initial position of the movable die with respect to the die or punch when the plate material is press-formed based on the plate material thickness measured by the plate thickness measuring device. May be good.
[0041]
(Structure 5)
In the above configuration 4, the plate thickness measuring device may be capable of measuring the plate thickness at the first location and the second location. The movable mold may include a first inner pad and a second inner pad provided on the top of the punch. The first inner pad and the first portion may be arranged on a line parallel to the transport direction of the transport device. The second inner pad and the second portion may be arranged on a line parallel to the transport direction of the transport device.
[0042]
In the above configuration 5, the first portion and the first inner pad of the plate material measured by the plurality of plate thickness measuring devices are arranged on a line parallel to the transport direction, and the second portion and the second inner pad are aligned in the transport direction. Line up on parallel lines. This makes it possible to control the first inner pad and the second inner pad corresponding to each of the measurement positions of the plurality of plate materials according to the plate thickness of each measurement position.
[0043]
[Embodiment]
(Press line)
FIG. 1 is a diagram showing a configuration example of the press line 100 in this embodiment. The press line 100 shown in FIG. 1 includes a transfer device 4, an intermediate forming press device 3, a press device 5, a plate thickness measuring device 10, and a controller 11. The plate thickness measuring device 10 is arranged upstream of the press device 5. The plate thickness measuring device 10 measures the plate thickness of the plate material B to be pressed by the press device 5. The transport device 4 transports the blank A to the intermediate forming press device 3. Further, the transport device 4 transports the plate material B from the plate thickness measuring device 10 to the press device 5. That is, the transport device 4 transports the plate material from the position where the plate thickness measuring device 10 measures the plate thickness of the plate material to the press device 5.
[0044]
The transport device 4 may be, for example, a conveyor having a transport path leading to the press device 5. In this case, the transport path of the transport device 4 is arranged so as to pass through the measurement area of ​​the plate thickness measuring device 10. The transport device 4 is not limited to the conveyor. For example, the transfer device 4 may be a manipulator composed of an articulated robot. In this case, the manipulator conveys the plate material placed on the material table or the mold placed upstream of the press device 5 to the press device 5. The plate thickness measuring device 10 is arranged so that the plate thickness of the plate material being conveyed can be measured on the material table or by a manipulator. The transport device 4 may be an unmanned operation or a manned operation forklift.
[0045]
The place where the plate thickness measuring device 10 measures the plate thickness of the plate material 1 is not limited to the example shown in FIG. The plate thickness measuring device 10 measures the plate thickness of the plate material before being press-molded by the press device 5. For example, in addition to the transfer device 4, the plate thickness of the plate material may be measured by the intermediate forming press device 3 or the press device 5.
[0046]
The press device 5 press-molds the plate material B into a press-molded product C. The press device 5 has a die 6, a punch 7, a die side pad 8, and a punch side inner pad 9 as a die. The die-side pad 8 and the punch-side inner pad 9 can change their relative positions with respect to both the die 6 and the punch 7. The press device 5 arranges the plate material B between the die 6 and the punch 7, and presses the plate material B from both the die 6 and the punch 7 to press-mold the plate material B.
[0047]
Specifically, the press device 5 press-molds the plate material B between the die 6 and the punch 7 while pushing the punch 7 inside the die 6 by the relative movement of the die 6 and the punch 7. In the press molding process for making one press-molded product, the punch-side inner pad 9 is in contact with the plate material B, and the relative position between the punch-side inner pad and the punch 7 is fixed at the set position (initial position). A step (first press step) of pushing the plate material B by the die 6 and the punch 7 by bringing the die 6 and the punch 7 relatively close to each other is included. Further, this press forming step includes a step (second pressing step) of press forming the plate material by bringing the die 6 and the punch 7 relatively close to each other while accommodating the punch side inner pad 9 in the punch 7.
[0048]
The plate thickness measuring device 10 measures the plate thickness of the plate material to be pressed. The plate material to be pressed is, for example, a blank before press molding by the press device 5, or an intermediate molded product. FIG. 1 shows an example of measuring the plate thickness of the intermediate molded product B. In FIG. 1, for example, the intermediate forming press device 3 may be omitted. In this case, the plate thickness measuring device 10 measures the plate thickness of the blank A.
[0049]
The plate thickness measuring device 10 may be configured to measure the plate thickness of the plate material from the side surface of the plate material by using an optical sensor, for example. Further, the plate thickness measuring device 10 may be configured to measure the plate thickness of the plate material, for example, by measuring the shape of the plate material from both the front and back surfaces of the laser displacement meter. The plate thickness measuring device 10 may measure, for example, the thickness of the surface of the plate material in the normal direction as the plate thickness of the plate material. Measurement mode of the plate thickness measuring device 10 Is not limited to a specific one. In addition to the above example, for example, the plate thickness can be indirectly measured by measuring the distance from the eddy current meter from both the front and back surfaces of the plate material.
[0050]
The controller 11 is connected to the press device 5 and the plate thickness measuring device 10. Here, the connection between the controller 11 and the press device 5 and the plate thickness measuring device 10 may be wired or wireless. The controller 11 can communicate with the press device 5 and the plate thickness measuring device 10. The controller 11 may be built in the press device 5 or the plate thickness measuring device 10, or may be an independent device.
[0051]
The controller 11 can be configured by, for example, a computer including a processor 11a and a storage device 11b (memory). The processor 11a can realize the following functions of the controller 11 by executing the program stored in the storage device 11b. The controller 11 controls the relative positions of the die-side pad 8 and the punch-side inner pad 9 with respect to the die 6 or the punch 7 in press forming by using the data regarding the plate thickness of the plate material measured by the plate thickness measuring device 10. Specifically, the controller 11 sets the relative position of the die side pad 8 and the punch side inner pad 9 with respect to the die 6 or the punch 7 based on the data regarding the plate thickness of the plate material measured by the plate thickness measuring device 10.
[0052]
Here, the relative position set by the controller 11 is, for example, when the die 6 and the punch 7 are relatively close to each other and press-molded with the allowance from the punch 7 of the punch side inner pad 9 fixed to the set amount. It can be the above-mentioned set amount (that is, the initial position) of (the above-mentioned first press step). That is, the set amount in this first press process is controlled by the controller 11.
[0053]
The controller 11 uses, for example, correspondence data indicating the correspondence between the plate thickness recorded in advance in the storage device 11b and the initial position with respect to the die or punch of the movable die (for example, the allowance from the punch of the punch side inner pad). Therefore, it is possible to determine the control of the initial position of the movable die (the allowance from the punch of the inner pad on the punch side) according to the measured plate thickness. The corresponding data is data showing the correspondence relationship between the initial position of the movable die (the allowance of the punch side inner pad 9 from the punch 7) at the time of press molding (for example, in the first press process) and the plate thickness of the plate material. Is. Specifically, the corresponding data includes a value indicating the plate thickness of the plate material obtained by measurement and a value for controlling the initial position of the movable die in press forming (the allowance of the punch side inner pad 9 from the punch 7). It may be data showing the correspondence between. The data format of the corresponding data is not particularly limited. The corresponding data may be data (for example, table data, map data, etc.) that associates a value indicating the plate thickness of the plate material with a value for controlling the movable die (punch side inner pad 9). Alternatively, the corresponding data shows the processing procedure of the processor that calculates the value for controlling the initial position of the movable die (the allowance from the punch of the inner pad on the punch side) by using the value indicating the plate thickness of the plate material. It may be data (eg, a function, a program or parameters thereof, etc.). Corresponding data is based on, for example, the plate thicknesses of a plurality of plate materials measured in the past, the initial position of the movable die when those plates are press-molded, and the shape of the press-molded product obtained by press molding. , Can be created.
[0054]
For example, the controller 11 acquires data indicating the plate thickness of the plate material from the plate thickness measuring device 10. The controller 11 uses the corresponding data to convert a value indicating the plate thickness of the plate material into a control value indicating the initial position (the allowance of the punch side inner pad 9 from the punch 7) with respect to the die or punch of the movable die. .. The controller 11 controls the press device 5 so that the initial position of the movable die at the time of press molding (the allowance for ejecting the inner pad 9 on the punch side from the punch 7) becomes the allowance indicated by the control value.
[0055]
The press device 5 repeatedly press-molds a plurality of plate materials B included in a production lot, for example, to manufacture a plurality of press-molded products. In the press molding of each of the plurality of plate materials, the controller 11 may set the initial position of the movable die (the allowance of the punch side inner pad 9 from the punch 7). The controller 11 uses data indicating the plate thickness of the plate material B to set the initial position of the movable die (the allowance of the punch side inner pad 9 from the punch 7) in the press forming of one plate material B. .. This enables feedforward control of the initial position of the movable die (the allowance of the punch side inner pad 9 from the punch 7) according to the plate thickness of the plate material.
[0056]
(Configuration example of press device and plate thickness measuring device)
FIG. 2 is a perspective view showing a configuration example of a press device 5 having a movable die. In the example shown in FIG. 2, the movable mold has a die 6 having a concave portion, a punch 7 having a convex portion corresponding to the concave portion of the die 6, and a die side that is relatively movable with respect to the die 6 and the punch 7. The pad 8 and the punch side inner pad 9 are included. The die-side pad 8 forms a part of the recess of the die 6 and can protrude toward the punch 7 with respect to the recess of the die 6. The punch-side inner pad 9 forms a part of the convex portion of the punch 7 and can project to the die 6 side with respect to the convex portion of the punch 7.
[0057]
The plate material B is conveyed between the die 6 and the punch 7. The transport direction F of the plate material B is substantially perpendicular to the extending direction of the ridge line 7b of the convex portion of the punch 7. The ridge line 7b of the convex portion of the punch 7 comes into contact with the plate material B during press forming. The ridge line 7b of the convex portion of the punch 7 is the ridge line of the punch shoulder. In the example shown in FIG. 2, a plurality of punch-side inner pads 9 are provided. The plurality of punch-side inner pads 9 are arranged at intervals from each other in a direction perpendicular to the transport direction of the plate material. In other words, the plurality of punch-side inner pads 9 are arranged at intervals from each other in the extending direction of the ridge line 7b of the convex portion of the punch 7. The direction of the ridge line 9b of the punch-side inner pad 9 is the same as the direction of the ridge line 7b of the convex portion of the punch 7. In this example, the punch-side inner pad 9 is provided not entirely in the direction perpendicular to the transport direction of the punch 7, but is provided in a part thereof. Any two of the plurality of punch-side inner pads 9 are examples of the first inner pad and the second inner pad. Further, the first inner pad and the second inner pad are examples of a plurality of movable mold portions.
[0058]
A plurality of die side pads 8 are provided. The plurality of die-side pads 8 are provided at positions corresponding to the plurality of punch-side inner pads 9. The plurality of die-side pads 8 are arranged at intervals from each other in a direction perpendicular to the transport direction of the plate material. The die-side pad 8 is provided on a part of the die 6 in a direction perpendicular to the transport direction, not the whole.
[0059]
In the example shown in FIG. 2, the punch side inner pad 9 and the plate thickness measuring device 10 are arranged on the line L1 parallel to the transfer direction F of the plate material. That is, the measurement position P of the plate thickness measuring device 10 and the punch side inner pad 9 are arranged on the line L1 parallel to the transport direction F. FIG. 3A is a diagram showing an arrangement example of the punch 7 and the plate material B as viewed from above. As shown in FIG. 3A, the measurement position P of the plate thickness measuring device 10 is arranged in a region extending upstream of the punch side inner pad 9 in the transport direction. In other words, the movable portion (punch side inner pad) 9 and the plate thickness measuring position P of the plate material B are lined up in the direction in which the plate material is drawn into the movable mold.
[0060]
In the configuration shown in FIG. 2, there is a portion where the plate thickness of the plate material B is measured in the cross section including each of the punch side inner pads 9 which is perpendicular to the ridge line 7b of the punch shoulder of the punch 7. The ridgeline 7b of the punch shoulder of the punch 7 is a ridgeline formed by the punch shoulders in contact with the plate material during pressing. In the example shown in FIG. 2, the ridge line 7b of the punch shoulder of the punch 7 extends in the transport direction of the plate material B. The extending direction of the ridge line 7b of the punch shoulder is substantially parallel to the extending direction of the ridge line of the die shoulder (edge ​​of the concave portion of the die) of the die 6. In the following description, the cross section perpendicular to the ridgeline 7b of the punch shoulder may be replaced with the cross section perpendicular to the ridgeline of the die shoulder.
[0061]
In the example shown in FIG. 2, a plurality of plate thickness measuring devices 10 corresponding to a plurality of punch-side inner pads 9 are provided. The plate thickness measuring points by the plurality of punch-side inner pads 9 and the plurality of plate thickness measuring devices 10 are arranged side by side on the line L1 parallel to the transport direction. In the example shown in FIG. 2, the plate thickness measuring points of the plate thickness measuring device 10 corresponding to all of the plurality of punch-side inner pads 9 are provided. The number of punch-side inner pads 9 and the number of plate thickness measuring points of the plate thickness measuring device 10 do not have to be the same. A plate thickness measuring point of the plate thickness measuring device 10 may be provided corresponding to a part of a plurality of punch-side inner pads 9. Further, one plate thickness measuring device 10 may be configured to measure the plate thickness at a plurality of locations.
[0062]
For example, when the plate material is a differential thickness metal plate having a thick portion and a thin portion, the plate thickness measuring device 10 may be configured to measure the plate thickness of each of the thick portion and the thin portion. In this case, even if the cross section is perpendicular to the ridge line 7b of the punch shoulder and includes each of the plurality of punch-side inner pads 9, there may be a thick-walled plate thickness measuring point and a thin-walled plate thickness measuring point. good. For example, in the configuration shown in FIG. 2, a plurality of plate thickness measuring devices 10 may include one that measures a thick portion and one that measures a thin portion.
[0063]
Further, a measurement in a thick portion of the plate material B is performed in a cross section perpendicular to the ridge line 7b of the punch shoulder, including a part of the punch side inner pads 9 (an example of the first inner pad) among the plurality of punch side inner pads 9. There is a portion, and the punch side inner pad 9 (an example of the second inner pad) of some other punch side inner pads 9 among the plurality of punch side inner pads 9 is included, and the thin wall of the plate material B is included in the cross section perpendicular to the ridge line 7b of the punch shoulder. There may be a measurement point in the section.
[0064]
FIG. 3B is a diagram showing a measurement position of the plate thickness when the plate material B includes the thick portion R1 and the thin portion R2, and an arrangement example seen from above of the punch side inner pad 9. In the plate material B of FIG. 3B, the region of the thick portion R1 is indicated by dots. In the example shown in FIG. 3B, the plate thickness measurement position P2 of the thick portion R1 of the plate material B and one punch side inner pad 92 are arranged in the transport direction F of the plate material B, and the plate thickness measurement position of the thin wall portion R2 of the plate material B. P1 and P3 and the other punch-side inner pads 91 and 93 are arranged in the transport direction F of the plate material B. In this case, the controller 11 controls the allowance (initial position) of the punch side inner pad 92 from the punch 7 based on the plate thickness measured at the measurement position P2 of the thick portion R1. Further, the controller 11 controls the allowance (initial position) from the punch 7 of each of the punch side inner pads 91 and 93 based on the plate thickness measured at the measurement positions P1 and P3 of the thin wall portion R2. Thereby, the allowance (initial position) from the punch 7 of the punch side inner pads 91 to 93 suitable for both the thick portion R1 and the thin portion R2 can be set.
[0065]
Further, for example, when the plate material is a metal plate having a high-strength portion and a low-strength portion, the plate thickness measuring device 10 may be configured to measure the plate thickness of each of the high-strength portion and the low-strength portion. In this case, the punch side inner pad 9 may be included, and the plate thickness measuring portion of the high-strength portion and the plate thickness measuring portion of the low-strength portion may be configured in the cross section perpendicular to the ridge line 7b of the punch shoulder. For example, in the configuration shown in FIG. 2, a plurality of plate thickness measuring devices 10 may include one that measures a high-strength portion and one that measures a low-strength portion. The metal plate having the high-strength portion and the low-strength portion may be, for example, a tailored blank material or a partially hardened steel plate.
[0066]
Further, a measurement in a high-strength portion of the plate material B is performed in a cross section perpendicular to the ridge line 7b of the punch shoulder, including a part of the punch side inner pads 9 (an example of the first inner pad) among the plurality of punch side inner pads 9. There is a portion, and the punch side inner pad 9 (an example of the second inner pad) of some other punch side inner pads 9 among the plurality of punch side inner pads 9 is included, and the plate material B is lowered in the cross section perpendicular to the ridge line 7b of the punch shoulder. There may be a measurement point in the strength section.
[0067]
The measurement position of the plate thickness when the plate material B contains a high-strength part and a low-strength part, and the panel The arrangement of the inner pad 9 on the inch side as viewed from above may be the same as that in FIG. 3B in which R1 is replaced with a high-strength portion and R2 is replaced with a low-strength portion. In this case, the plate thickness measurement position P2 of the high-strength portion R1 of the plate material B and one punch-side inner pad 92 are arranged in the transport direction F of the plate material B, and the plate thickness measurement positions P1 and P3 of the low-strength portion R2 of the plate material B are arranged. And the other punch side inner pads 91 and 93 are lined up in the transport direction F of the plate material B. In this case, the controller 11 controls the allowance (initial position) of the punch-side inner pad 92 from the punch 7 based on the plate thickness measured at the measurement position P2 of the high-strength portion R1. Further, the controller 11 controls the allowance (initial position) from the punch 7 of each of the punch side inner pads 91 and 93 based on the plate thickness measured at the measurement positions P1 and P3 of the low-strength portion R2. Thereby, the allowance (initial position) from the punch 7 of the punch side inner pads 91 to 93 suitable for both the high-strength portion R1 and the low-strength portion R2 can be set.
[0068]
(Example of press molding)
Next, an example of press molding using a movable part will be described. 4A to 4D are views showing an example of press molding. Here, as an example, a press forming example using a press device provided with the punch side inner pad 9 as the first inner pad and the second inner pad will be described. In the example shown in FIGS. 4A to 4D, the die side pad 8 is arranged inside the die 6 and can move in the pressurizing direction of the plate material. Here, the pressurizing direction of the plate material is the direction of relative movement of the die 6 with respect to the punch 7. The punch-side inner pad 9 is arranged so as to project outward from the pressure surface 7a of the punch 7, and can be pushed to the same height as the pressure surface 7a of the punch 7.
[0069]
Specifically, the die 6 has a recess 6a corresponding to the shape of the press-molded product inside. The punch 7 has a convex portion having a shape corresponding to the concave portion 6a of the die 6. The upper surface of this convex portion serves as a pressure surface 7a that pressurizes the plate material B. The punch-side inner pad 9 is movable in the vertical direction (pressurizing direction) with respect to the punch 7 via, for example, a gas spring 9s or an elevating mechanism such as a cushion mechanism of a press machine. The die-side pad 8 is installed on the slide 6d of the press device via, for example, an elevating mechanism such as a gas spring 8s. A die 6 is fixed to the slide 6d. The die-side pad 8 can move in the vertical direction together with the slide 6d. The distance between the die side pad 8 and the slide 6d can be expanded and contracted by the gas spring 8s. A hole (not shown) for passing the elevating mechanism is provided on the bottom surface of the recess 6a of the die 6. The punch-side inner pad 9 is arranged inside a recess formed in the pressurizing surface 7a of the punch 7. Further, the punch-side inner pad 9 is urged upward by a gas spring 9s arranged inside the recess. Due to the urging of the gas spring 9s, the upper surface of the inner pad 9 on the punch side is in a state of protruding outward from the pressure surface 7a of the punch 7. The distance between the punch 7 and the punch-side inner pad 9 changes due to the expansion and contraction of the gas spring 9s.
[0070]
The die side pad 8 and the punch side inner pad 9 can move relative to the die 6 or the punch 7 in a state of being pressed against the plate material B. For example, the die 6 can be brought closer to the punch 7 while the die-side pad 8 and the punch-side inner pad 9 stand still with the plate material B sandwiched between them. When the die side pad 8 and the punch side inner pad 9 sandwiching the plate material B are stationary while the slide 6d, that is, the die 6 moves closer to the punch 7, the gas spring 8s (elevation mechanism) of the die side pad 8 is used. Shrinks. While the die 6 moves closer to the punch 7, the gas spring 8s (elevating mechanism) of the die side pad 8 does not expand or contract when the die side pad 8 moves closer to the punch 7.
[0071]
In the press device 5, the punch side inner pad 9 and the die side pad 8 are pressed against the plate material B in a state where the punch side inner pad 9 is projected outward from the pressurizing surface 7a of the punch 7, and the die 6 and the punch 7 are pressed. And are relatively close to each other, and the plate material B is press-molded. At the bottom dead center of molding, the plate material B is press-molded until the inner pad 9 on the punch side becomes the same height as the pressure surface 7a of the punch 7.
[0072]
More specifically, first, as shown in FIG. 4A, the die side pad 8 is pressed against the plate material B in a state where the punch side inner pad 9 is projected outward from the pressure surface 7a of the punch 7 while the die is pressed. By lowering the die 6 and the die side pad 8, the plate material B is press-formed between the die 6 and the punch 7. At this time, the relative position of the punch-side inner pad 9 with respect to the punch 7, that is, the height (protrusion amount) H of the upper surface of the punch-side inner pad 9 with respect to the pressure surface 7a of the punch 7 is fixed to a set value (value at the initial position). .. The protrusion amount H is set based on the plate thickness measured at the measurement position P of the plate material B. In the plate material B to be formed, slack Ba is generated in the plate material B according to the height (projection amount) H of the upper surface of the punch side inner pad 9 with respect to the pressure surface 7a of the punch 7. Then, from this state, as shown in FIG. 4B, the press molding is continued by lowering the die 6 while controlling the slack Ba of the plate material B to a predetermined amount. As shown in FIG. 4C, the die 6 is lowered to H before the bottom dead center of molding (position at a distance H from the bottom dead center of molding). At this time, the die 6 is lowered while the pressurizing mechanism of the die side pad 8 is contracted.
[0073]
In the steps shown in FIGS. 4A to 4C, the die 6 and the punch 7 are relatively close to each other in a state where the protrusion allowance of the punch 7 from the punch side inner pad 9, that is, the protrusion amount H is fixed to the set value. From the stage shown in FIG. 4C, that is, the stage in which the die-side pad 8 is completely retracted by being bottomed out with respect to the die 6 (the stage in front of the molding bottom dead center by the amount of protrusion H), the punch-side inner pad 9 The distance between the upper surface of the punch 7 and the pressure surface 7a of the punch 7 begins to shrink. From the stage of FIG. 4C to the stage of FIG. 4D, the relative position of the punch 7 with respect to the punch-side inner pad 9 changes. As shown in FIG. 4D, the plate material B is press-formed until the upper surface of the punch-side inner pad 9 has the same height as the pressure surface 7a of the punch 7. At this time, the slack Ba formed in the plate material B flows out toward the vertical wall portion between the punch 7 and the die 6 while receiving the in-plane compressive stress. Thereby, a press-molded product having a hat-shaped cross-sectional shape can be obtained.
[0074]
In the examples shown in FIGS. 4A to 4D, the bending region that contributes to the inward direction, that is, the spring go, is expanded by crushing the slack Ba formed in the plate material B and letting it flow out toward the vertical wall portion. As a result, it is possible to balance the spring back and the spring go of the work material to be press-molded. As a result, it is possible to reduce the shape defect of the vertical wall.
[0075]
Further, in the press forming process from FIG. 4A to FIG. 4D, the outer portion Bb of the plate material B sandwiched between the die side pad 8 and the punch side inner pad 9 slides with the die 6 and the punch 7. Be pressed. It is preferable that the portion Bb of the plate material that slides with the die 6 or the punch 7 in this press molding includes the position P whose plate thickness is measured by the plate thickness measuring device 10. In other words, at the time of press molding, it is preferable that the plate thickness of the plate material is measured at a point perpendicular to the ridge line of the movable die in contact with the plate material and within the cross section including the ridge line. This is because the plate thickness of the portion affected by the shape of the press-molded product is measured.
[0076]
In the above example, in the press forming on one plate material B, the die 6 is relatively close to the punch 7 in a state where the allowance from the punch 7 of the punch side inner pad 9 is fixed (the state of the initial press setting). A step of press-molding the plate material B and a step of press-molding the plate material B by changing the ejection allowance of the punch-side inner pad 9 from the punch 7 and bringing the die 6 relatively close to the punch 7. The protrusion allowance of the punch-side inner pad 9 from the punch 7 in the initial setting of the press, that is, the protrusion amount H of the punch-side inner pad 9, is controlled by the controller 11. The protrusion amount H is an example of a set amount (initial position of the movable die) of the punch 7 of the punch side inner pad.
[0077]
The controller 11 determines the protrusion amount H of the punch side inner pad 9 based on the plate thickness measured at the measurement position P of the plate material B. In the example shown in FIGS. 4A to 4D, the measurement position P is included in the cross section including the ridge line 9b in contact with the plate material B of the punch side inner pad 9 and perpendicular to the ridge line 9b. Thereby, the protrusion amount H of the punch side inner pad 9 can be controlled according to the plate thickness of the portion of the plate material B which tends to affect the shape of the press-molded product.
[0078]
Note that press molding using a movable part is not limited to the above example. For example, in the press device, either the die side pad 8 or the punch side inner pad 9 can be omitted. Further, the above example is an example of press-molding a plate material B as an intermediate material which has been previously bent-molded, but the press apparatus may be one that press-molds a flat plate that has not been bent-molded.
[0079]
Generally, in bending molding, the die side pad is often set to prevent misalignment of the plate material with respect to the punch side inner pad. In other words, the die-side pad may be omitted in a shape that does not easily shift. Even in the molding examples shown in FIGS. 4A to 4D, the die side pad 8 may be omitted. In the molding examples shown in FIGS. 4A to 4D, when the die side pad 8 is omitted, the portion corresponding to the die side pad 8 is stored in the recessed portion of the die 6 from the initial stage of molding to the stage shown in FIG. 4C. It becomes a state of being integrated with the die in the state where it is done. From the initial stage of molding to the stage shown in FIG. 4C, the central portion of the plate material B in the cross-sectional width direction is press-molded in a state of being lifted from the lower side by the punch-side inner pad 9 as in the case of having the die-side pad 8. Goes forward. After the step shown in FIG. 4C, the punch-side inner pad 9 is pushed downward by the die 6 to lower, and press forming is completed in the same manner as in FIG. 4D.
[0080] [0080]
(Example of press-molded product)
FIG. 5 is a cross-sectional view showing an example of a press-molded product. The press-molded product 12 shown in FIG. 5 is obtained, for example, by press-molding shown in FIGS. 4A to 4D. The press-molded product 12 has a hat-shaped cross section. The press-molded product 12 is a long member whose longitudinal direction is perpendicular to the cross section shown in FIG. A top plate 12A extending in the width direction of the press-molded product 12 and a pair of ridge line portions 12B adjacent to both ends in the width direction of the top plate 12A are included. Further, the press-molded product 12 includes a pair of vertical walls 12C extending from the ridge line portion 12B to the back surface side (one side in the plate thickness direction) of the top plate 12A, and a pair adjacent to the tips (lower ends) of the pair of vertical walls 12C. Includes the ridgeline portion 12D of. Further, the press-molded product 12 includes a pair of flanges 12E extending from the pair of ridge line portions 12D to both sides of the top plate 12A in the width direction. The angle θ2 formed by the top plate 12A and the vertical wall 12C is 90 deg. Not limited to the case of. The angle θ2 is 90 to 125 deg. Can be exemplified. In the strong machining in this range, problems such as springback become apparent, so that the feedback control becomes effective. The angle θ2 is 90 deg. If the angle is less than that, it may interfere with removing the press-molded product from the mold.
[0081]
In the press-molded product 12, for example, the angle θ1 formed by the top plate 12A and the flange 12E may be measured. In this example, each θ1 formed by the top plate 12A and the flange 12E has a predetermined reference value θc indicating a desired shape, in this case 0 deg. If it is larger (θ1> θc = 0deg.), It becomes a springback, and if θ1 is smaller than the reference value θc (θ1 <θc = 0deg.), It becomes a spring go. The value indicating the degree of spring back or spring go is not limited to the angle θ1 in the above example. For example, the angle θ2 formed by the top plate 12A and the flange 12E, or the vertical height difference T1 of the bottom surface of the flange 12E may be measured as a value indicating the degree of springback or spring go.
[0082]
(Operation example)
FIG. 6 shows the controller in this embodiment. It is a flow chart which shows the operation example of a trawler 11. In the example shown in FIG. 6, first, the controller 11 initially sets the press conditions (S1). Press conditions include, for example, the relative position of the moving part with respect to the die or punch. As an example, the initial value of the protrusion amount H of the punch side inner pad 9 is set. The pressing conditions are not limited to the relative positions of the moving parts.
[0083]
The controller 11 acquires the corresponding data obtained in advance (S2). For example, the controller 11 determines the corresponding data to be used for the feedback process and makes it accessible. For example, the corresponding data used for processing is extracted from the data previously recorded in the recording medium (internal or external storage device built in the controller 11) accessible to the computer of the controller 11 and stored in the memory (storage device 11b). do. Corresponding data is created in advance before press molding and recorded in a storage medium accessible to the controller 11.
[0084]
Here, an example of corresponding data will be described. FIG. 7 is a graph showing an example of the relationship between the shape of the press-molded product and the protrusion amount H of the punch-side inner pad 9. The graph shown in FIG. 7 shows the relationship between the protrusion amount H of the punch-side inner pad 9 and the springback / spring go. The angle difference on the vertical axis of the graph is the angle θ1 and the reference value θc formed by the top plate 12A and the flange 12E of the press-molded product 12 shown in FIG. 5, in this case 0deg. The difference from (θ1-θc (here, θc = 0deg.)) Is shown. The reference value θc is the angle formed by the top plate and the flange 12E when there is no spring back and spring go. If the angle difference is positive, it is spring back, and if the angle difference is negative, it is spring go. In the relationship shown in the graph shown in FIG. 7, the appropriate value Ha of the protrusion amount of the punch side inner pad is the protrusion amount when the angle difference becomes 0.
[0085]
FIG. 8 is a graph showing an example of the relationship between the appropriate protrusion amount and the plate thickness of the plate material. The vertical axis of the graph shown in FIG. 8 shows the protrusion amount of the punch side inner pad when the angle difference (θ1-θc) becomes 0, that is, when there is no spring bag and spring go. As shown in FIG. 8, the inventor has found that the plate thickness of the plate material and the appropriate protrusion amount of the punch-side inner pad are correlated with each other. The controller 11 can determine an appropriate protrusion amount based on the measured plate thickness of the plate material by using the corresponding data showing such a correlation. For example, the formula representing the line of the graph shown in FIG. 8 or the data showing each plot in the graph can be used as the corresponding data.
[0086]
In S3 of FIG. 6, the plate thickness measuring device 10 next measures the plate thickness of the plate material B to be conveyed to the movable mold. The controller 11 acquires the measurement result of the plate thickness of the plate material from the plate thickness measuring device 10. As an example, as shown in FIG. 2, the plate thickness is measured at the measurement position P of the plate material B upstream in the transport direction of each punch-side inner pad 9.
[0087]
The controller 11 sets the relative position (initial position) of the punch side inner pad 9 with respect to the punch, for example, the protrusion amount H, based on the plate thickness of the plate material measured in S3 (S4). The controller 11 controls the press device 5 to control the protrusion amount H of the punch side inner pad 9 with respect to the punch 7 to a value set based on the plate thickness. The controller 11 executes press molding while controlling the protrusion amount H (S5). In S5, press forming is executed on the plate material whose plate thickness has been measured in S3 with the protrusion allowance (protrusion amount H) of the punch side inner pad 9 set in S4.
[0088]
The processing of S3 to S5 in FIG. 6 is repeated for a plurality of plate materials contained in one production lot. This enables feedforward control based on the plate thickness of the plate material in each of the press forming of one production lot.
[0089]
(Example of plate material)
The material of the plate material to which the present invention can be applied is not particularly limited. As the material of the plate material, for example, a thin plate of 980 MPa class high strength steel sheets (High Tensile Strength Steel Sheets) may be used. In recent years, in order to reduce the weight of press-molded products, the strength of press-molded products has been increasing. In line with this, the strength of press-molded materials is increasing. As the strength of the material increases, it becomes difficult to press-mold it into a desired shape. For example, spring packs generally become more intense as the material becomes stronger. According to the above embodiment, even when a plate material having a tensile strength of 980 MPa or more is used, it is possible to reduce the deviation or variation of the shapes of the plurality of press-molded products from the target shape.
[0090]
Further, in general, for example, between a steel sheet having a tensile strength of 270 MPa class and a steel sheet having a tensile strength of 1.2 GPa class, the variation in plate thickness tends to be larger in the steel sheet having a tensile strength of 1.2 GPa class. If the plate thickness varies widely, the mold shape is adjusted, and even if the shape of the press-molded product that was press-molded at the beginning of the production lot is the desired shape, the press-molded product that is press-molded later in the production lot is also available. There is a high possibility that the desired shape will not be obtained. According to the above embodiment, even when a plate material having a tensile strength of 980 MPa or more, which has a relatively large variation in material characteristics as compared with a low-strength steel plate, is used, the relative position of the movable portion based on the plate thickness. By the feedforward control of, the variation in the shape of a plurality of press-molded products can be reduced.
[0091]
(Example)
FIG. 9 is a histogram showing the result of measuring the position accuracy of the flange when the protrusion amount H of the punch side inner pad 9 is not feedforward controlled based on the plate thickness of the plate material. FIG. 10 is a histogram showing the result of measuring the position accuracy of the flange when the protrusion amount H of the punch side inner pad 9 is feedforward controlled based on the plate thickness of the plate material. In FIGS. 9 and 10, the upper histogram shows the distribution of the plate thickness of the plate material contained in one test lot. The plate thickness of the plate material is randomly changed for each shot of press molding within a range of about 0.1 mm. The lower histogram shows the distribution of flange accuracy in one test lot. The flange position accuracy is the height difference of the flange (corresponding to T1 shown in FIG. 5). For the flange position accuracy, the target reference position is 0.0. As the material of the plate material, a steel plate having a tensile strength of 1180 MPa was used.
[0092]
In the results shown in FIG. 9, when the plate thickness of the plate material varied in the range of about 0.1 mm, the standard deviation of the flange position accuracy was 0.25 mm. On the other hand, in the result shown in FIG. 10, when the plate thickness of the plate material varies in the range of about 0.1 mm, the standard deviation of the position accuracy of the flange is 0.11 mm. Further, the average value of the flange position accuracy was about 0.01 mm in each case. From these results, it is possible to suppress deviation and variation of the shape of the press-molded product from the target shape by performing feedforward control that controls the protrusion amount H of the punch-side inner pad 9 based on the plate thickness of the plate material. all right.
[0093]
Although one embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and the above-mentioned embodiment can be appropriately modified and carried out within a range not deviating from the gist thereof.
[0094]
For example, in the above embodiment, the movable die that controls the initial position based on the plate thickness is the inner pad of the punch, but the initial position of the die side pad provided on the die with respect to the die is controlled based on the plate thickness. May be done.
[0095]
In the above embodiment, as an example of measuring at a plurality of points on one plate, the plate thickness of the thick portion and the thin portion of one plate, or the region of the high strength portion and the low strength portion of one plate. Is being measured. The measurement of the plate thickness at a plurality of points on one plate is not limited to the above example. For example, the plate thickness of a plurality of points in the measurement target region of the plate material may be measured, and a value based on the plate thickness of the plurality of locations (for example, an average value) may be used as the plate thickness of the measurement target region.
[0096]
In the above embodiment, the plate thickness acquisition device for acquiring the plate thickness is a plate thickness measuring device. The plate thickness acquisition device may be an apparatus for acquiring data indicating the plate thickness of each of the plurality of plate materials B to be pressed. For example, when the plate thickness measuring device is located at a remote location, the plate thickness acquiring device may be configured to receive data indicating the plate thickness from the plate thickness measuring device or another communication device. The plate thickness acquisition device may be included in the controller. That is, the controller may be configured to acquire the plate thickness from an external device. The data indicating the plate thickness of each plate material is preferably the data of the measured value of the plate thickness, but the data indicating the plate thickness is not limited to the data of the actually measured value.
Description of the sign
[0097]
4: Conveyor device
5: Press equipment
6: Die
7: Punch
8: Die side pad
9: Punch side inner pad (1st inner pad, 2nd inner pad)
10: Plate thickness measuring device
11: Controller
12: Press molded product
The scope of the claims
[Claim 1]
Obtaining the plate thickness of one or more press target plates individually for each plate,
Includes press-molding the plate into a press-molded product with a die, a punch, and a movable die whose relative position can be changed with respect to both the die and the punch.
In the press molding, a method for manufacturing a press-molded product that controls the initial position of the movable die with respect to the die or the punch based on the plate thickness of the plate material.
[Claim 2]
The press molding includes continuous press molding of a plurality of plate materials.
The method for manufacturing a press-molded product according to claim 1, wherein the initial position of the movable die with respect to the die or the punch is controlled based on the plate thickness of the plate material in at least one of a plurality of continuous press moldings.
[Claim 3]
The acquisition of the plate thickness includes acquiring the plate thickness at a plurality of positions of one plate material.
The first or second aspect of the present invention, wherein in the press molding of the one plate thickness, the initial position of the movable die with respect to the die or the punch is controlled based on the plate thickness at a plurality of positions of the one plate material. How to manufacture press-molded products.
[Claim 4]
The movable mold includes a plurality of movable mold portions whose positions can be changed independently of each other.
The acquisition of the plate thickness includes acquiring the plate thickness at a plurality of positions corresponding to the plurality of movable mold portions of one plate material.
In the press molding of the one plate thickness, the initial position of each of the plurality of movable mold portions is controlled based on the plate thickness of the corresponding position among the plurality of positions of the one plate material. Item 3. The method for manufacturing a press-molded product according to Item 3.
[Claim 5]
The method for manufacturing a press-molded product according to any one of claims 1 to 4, wherein in the press molding, the portion where the plate thickness of the plate material is measured and the die slide.
[Claim 6]
The movable mold includes a first inner pad provided at the top of the punch.
The press-molded product according to claim 5, wherein in the press-molding, there is a portion where the plate thickness of the plate material is measured in a cross section perpendicular to the ridgeline of the punch shoulder of the punch and including the first inner pad. Production method.
[Claim 7]
The movable mold includes a first inner pad and a second inner pad provided on the top of the punch.
The plate material is a differential thickness metal plate having a thick portion and a thin portion thinner than the thick portion.
Acquisition of the plate thickness of the plate material includes acquisition of the plate thickness of the thick portion and the plate thickness of the thin portion.
In the press molding, there is a portion where the plate thickness of the thick portion is obtained in the cross section including the first inner pad, which is perpendicular to the ridgeline of the punch shoulder of the punch.
In the press molding, there is a portion where the plate thickness of the thin wall portion is obtained in the cross section perpendicular to the ridgeline of the punch shoulder and including the second inner pad.
In the press molding, the initial position of the first inner pad with respect to the punch is controlled based on the plate thickness of the thick portion, and the initial position of the second inner pad with respect to the punch is controlled based on the plate thickness of the thin portion. To control,
The fifth aspect of the present invention.Manufacturing method for press-molded products.
[Claim 8]
The movable mold includes a first inner pad and a second inner pad provided on the top of the punch.
The plate material includes a high-strength portion and a low-strength portion having a lower strength than the high-strength portion.
Acquisition of the plate thickness of the plate material includes acquisition of the plate thickness of the high-strength portion and the plate thickness of the low-strength portion.
The punch is equipped with a second inner pad,
In the press molding, there is a portion where the plate thickness of the high-strength portion is obtained in the cross section including the first inner pad, which is perpendicular to the ridgeline of the punch shoulder of the punch.
In the press molding, there is a portion perpendicular to the ridgeline of the punch shoulder and in the cross section including the second inner pad, where the plate thickness of the low-strength portion is obtained.
In the press molding, the initial position of the first inner pad with respect to the punch is controlled based on the plate thickness of the high-strength portion, and the initial position of the second inner pad with respect to the punch is controlled based on the plate thickness of the low-strength portion. Control the position value,
The method for manufacturing a press-molded product according to claim 5.
[Claim 9]
The press molding is
The first press step of press-molding the plate material by bringing the die and the punch relatively close to each other while the relative position of the movable die with respect to the die or the punch is fixed to the initial position.
Includes a second press step of press-molding the plate material by bringing the die and the punch relatively close to each other while accommodating the movable die in the die or the punch.
The method for manufacturing a press-molded product according to any one of claims 1 to 8, wherein in the press molding, the initial position of the movable die is controlled based on the plate thickness of the plate material.
[Claim 10]
The method for manufacturing a press-molded product according to any one of claims 1 to 9, wherein the tensile strength of the portion having the highest strength in the plate material is 980 MPa or more.
[Claim 11]
A plate thickness acquisition device that individually acquires the plate thickness of one or more press target plates for each plate material,
A press device equipped with a die, a punch, and a movable die that can move relative to both the punch and the die,
Equipped with a controller to control the press device
In the press molding of the plate material by the die, the punch, and the movable die, the controller performs an initial stage with respect to the die or the punch of the movable die based on the plate thickness of the plate material acquired by the plate thickness acquisition device. A press line that controls the position.
[Claim 12]
The press line according to claim 11, wherein the plate thickness acquisition unit is a plate thickness measuring device for measuring the plate thickness of the plate material.
[Claim 13]
The press line according to claim 12, wherein the plate thickness measuring point by the plate thickness measuring device is perpendicular to the ridgeline of the punch shoulder of the punch and is in the plane including the movable die.
[Claim 14]
Further equipped with a transport device capable of transporting the plate material to be pressed from the plate thickness measuring device to the press device.
The press line according to claim 12 or 13, wherein the movable die and the plate thickness measuring device are arranged on a line parallel to the transport direction of the transport device.
[Claim 15]
The plate thickness measuring device can measure the plate thickness at the first location and the second location.
The movable mold includes a first inner pad and a second inner pad provided on the top of the punch.
The first inner pad and the first portion are arranged on a line parallel to the transport direction of the transport device.
The press line according to claim 14, wherein the second inner pad and the second portion are arranged on a line parallel to the transport direction of the transport device.