Press equipment

Abstract

To provide a press device which enables more precise processing.SOLUTION: A press device (1) includes a slide (12), a plurality of driving parts (13a to 13c) for applying a load to the slide, and a control part (31) for determining a correction value of a moving amount of the slide. The correction value is changed depending on which of the plurality of driving parts is driven.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a press apparatus. [Background technology]

[0002] Patent Document 1 discloses that in a press machine, the amount of movement of a slide is corrected in accordance with the extension of the side frame (tie rod and upright). This correction can improve the accuracy of press working. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-022610 Summary of the Invention [Problem to be solved by the invention]

[0004] In a press device, when a large load is applied to the slide, deflection may occur in components other than the side frame.

[0005] An object of the present invention is to provide a press device that can further improve processing accuracy. [Means for solving the problem]

[0006] The press device according to the present invention comprises: Slides and a plurality of drive units that apply loads to the slide; a control unit that calculates a correction value for the amount of movement of the slide, The correction value changes depending on which of the plurality of driving units is driving. [Effects of the Invention]

[0007] According to the present invention, more precise machining can be achieved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a press device according to an embodiment of the present invention; [Figure 2] FIG. 10 is a front view illustrating deflection of the press device. [Figure 3] FIG. 10 is an explanatory diagram showing a breakdown of deflection that affects forming accuracy. [Figure 4] 10 is a graph illustrating the relationship between a selection pattern of a plurality of drive units and the amount of deflection of a slide. [Figure 5] 10 is a graph illustrating the relationship between the mold size and the amount of deflection of the slide and the lower frame. [Figure 6] 10 is an example of a data set prepared for deriving a deflection calculation formula. [Figure 7] 10 is a flowchart showing a press process executed by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing a press apparatus according to an embodiment of the present invention. The press apparatus 1 of this embodiment is an apparatus for clamping a workpiece such as a metal between dies 80 (a lower die 81 and an upper die 82) and applying a load to form the workpiece.

[0010] The press device 1 includes a lower frame 11, a slide 12 that moves up and down, a plurality of drive units 13a to 13c that apply load to the slide 12, an upper frame 14 that supports the plurality of drive units 13a to 13c, a side frame 15 that fastens the upper frame 14 and the lower frame 11, and a return cylinder 17 that pushes the slide 12 back upward.

[0011] The lower frame 11 is specifically a bed and a bolster. The upper frame 14 is specifically a crown. The side frames 15 are specifically uprights including tie rods that fasten the bed and the crown. The slide 12 is guided by the side frames 15 (uprights) so that it can move up and down. The side frames 15 are four support columns arranged front to back, left to right, but the number is not limited to four, and the shape is not limited to columnar, and may be wall-shaped.

[0012] A lower mold 81 is fixed to the lower frame 11. An upper mold 82 is fixed to the slide 12. When the slide 12 descends, the workpiece is sandwiched between the lower mold 81 and the upper mold 82, and when the drive units 13a to 13c press the slide 12, a load is applied to the workpiece, and the workpiece is molded to fit the cavity of the mold 80. Hereinafter, the distance between the lower mold 81 and the upper mold 82 will be referred to as the "mold distance." The lower mold 81 and the upper mold 82 have a point where they can come into contact when they are brought close to each other without sandwiching the workpiece, and the mold distance means the vertical distance at that point.

[0013] Each of the driving units 13a to 13c is, for example, a hydraulic driving mechanism (such as a ram cylinder), but the driving units 13a to 13c are not limited to such a driving mechanism and may be, for example, a mechanical driving mechanism that applies a load using the driving force of a servo motor, or may be a configuration in which a hydraulic driving mechanism and a mechanical driving mechanism are mixed.

[0014] The press device 1 further includes a position sensor 21 that measures the position of the slide 12, a temperature sensor 22 that measures the temperature of the die 80, and a load sensor 23 that measures the load applied to the die 80.

[0015] The position sensor 21 measures the relative position of the press apparatus 1. Specifically, the position sensor 21 is a linear encoder provided on the side frame 15 (upright) and the side of the slide 12, and measures the relative position (relative position in the up-down direction) of the side of the slide 12 with respect to the side frame 15 (upright). Because a large amount of lubricating oil adheres to the periphery of the die 80, by arranging the position sensor 21 as described above, the position of the slide 12, and therefore the position of the upper die 82, can be measured without being significantly affected by the lubricating oil.

[0016] The position sensor 21 is not limited to the above configuration, and may have any configuration as long as it can measure the relative position of a predetermined portion of the slide 12. The predetermined portion of the slide 12 to be measured may be a side portion of the slide 12 or a central portion of the slide 12.

[0017] The temperature sensor 22 includes two temperature sensors 22a and 22b that separately measure the temperature of the lower die 81 and the temperature of the upper die 82. As the temperature sensor 22, a remote-type thermometer (e.g., a radiation thermometer) that can measure the temperature at a distance from the object to be measured is used. When hot forming (e.g., hot forging) or warm forming (e.g., warm forging) is performed, the area around the die 80 becomes hot, and a large amount of lubricating oil adheres to the area around the die 80. Therefore, by using a remote-type thermometer, it is easy to secure a mounting location for the temperature sensor 22.

[0018] The load sensor 23 is a sensor that converts the detected deflection into a load, for example, by detecting a deflection of a part of the side frame 15. The load sensor 23 may be of any type as long as it can detect the load applied to the mold 80.

[0019] The press 1 further includes a control unit 31 that controls the drive units 13a to 13c, a display unit 32 that displays information about the press 1, and a display unit 33 that allows an operator to input information.

[0020] The control unit 31 can control at least the start and stop of driving of the drive units 13a to 13c by controlling the hydraulic circuit (for example, its control valve). The control unit 31 may also be configured to be able to control the pressure (load) of the drive units 13a to 13c. The above-mentioned hydraulic circuit is a circuit that supplies hydraulic pressure to the drive units 13a to 13c when the drive units 13a to 13c are hydraulic drive mechanisms. When the drive units 13a to 13c are mechanical drive mechanisms having servo motors, the control unit 31 is configured to perform the above-mentioned control by electrically controlling the servo motors.

[0021] The outputs of the position sensor 21 and the temperature sensor 22 are sent to the control unit 31. Information input via the input unit 33 is sent to the control unit 31. The control unit 31 is a computer that performs control operations based on a control program.

[0022] The display unit 32 is capable of displaying images or characters, and displays the stroke (amount of movement) of the slide 12. Here, the stroke represents the above-mentioned inter-die distance. In other words, the stroke represents the position of the slide 12, with the position where the lower die 81 and the upper die 82 are slightly in contact being the zero point. The display unit 32 displays the stroke of the slide 12 calculated by the control unit 31.

[0023] The input unit 33 is a keyboard, a mouse, a touch panel, or the like, and the operator can input the size of the mold 80 via the input unit 33. The information input from the input unit 33 is sent to the control unit 31. The mold 80 size that can be input includes at least the width and length (depth) of the lower mold 81 and the width and length (depth) of the upper mold 82. Furthermore, the mold 80 size that can be input may also include the height of the lower mold 81 and the height of the upper mold 82.

[0024] <Press equipment deflection> Fig. 2 is a front view illustrating the deflection of the press device, and Fig. 3 is an explanatory diagram showing the breakdown of the deflection that affects the forming accuracy.

[0025] When one or more of the drive units 13a to 13c are driven and a load is applied to the workpiece between the lower die 81 and the upper die 82, a reaction force causes deflection in each part of the press device 1. The deflection includes an extension of the side frame 15 in the vertical direction (deflection amount δ1), an arc-shaped deflection in which the center of the lower frame 11 becomes lower (deflection amount δ2), an arc-shaped deflection in which the center of the slide 12 becomes higher (deflection amount δ3), a deflection in which the lower die 81 is compressed in the vertical direction (deflection amount δ4), and a deflection in which the upper die 82 is compressed in the vertical direction (deflection amount δ5).

[0026] Furthermore, when the die 80 is heated during hot forming or warm forming, the die 80 expands in the vertical direction due to thermal expansion (deflection amount δ6).

[0027] Here, we will first explain the control when the above-mentioned deflection does not occur. When deflection does not occur, the stroke amount of slide 12 obtained from the output of position sensor 21 matches the distance between the dies. Therefore, for example, if a press molding of a specified thickness is achieved when the distance between the dies is 5 mm, stopping slide 12 when the stroke obtained from the output of position sensor 21 is 5 mm will stop slide 12 when the distance between the dies is 5 mm, and a molded product of the specified thickness will be obtained.

[0028] Next, a case where deflection occurs will be described. When the deflection shown in Figures 2 and 3 occurs, a deviation corresponding to the deflection occurs between the stroke measured by the position sensor 21 and the mold-to-mold distance. The amount of deviation is the sum of the above deflection amounts δ1 to δ6 converted into the amount of deviation in the mold-to-mold distance.

[0029] Of the deflections of the above-mentioned parts, the deflection amount δ6 due to thermal expansion of the mold 80 changes depending on the heat of the mold 80. In addition, the deflection amounts δ4 and δ5 due to compression of the mold 80 and the deflection amounts δ1, δ2, and δ3 of the side frame 15, the lower frame 11, and the slide 12 change depending on the load applied to the workpiece.

[0030] Furthermore, the deflection amounts δ2 and δ3 of the lower frame 11 and the slide 12 also change depending on other conditions, as shown in FIGS.

[0031] FIG. 4 is a graph illustrating the relationship between the selection pattern of the multiple drive units and the amount of deflection of the slide. The "selection pattern" of the multiple drive units 13a-13c refers to the pattern in which one of the multiple drive units 13a-13c is driven. In FIG. 4, the graph line for "one selection pattern" indicates a pattern in which one central drive unit 13b is driven, the graph line for "two selection patterns" indicates a pattern in which two drive units 13a and 13c on the left and right are driven, and the graph line for "three selection patterns" indicates a pattern in which three drive units 13a-13c are driven. As described above, when the selection pattern differs, the maximum load also differs depending on the number of drive units 13a-13c that are driven.

[0032] The amount of deflection in Fig. 4 changes (for example, is proportional to) the load. Furthermore, even if the load is the same, the amount of deflection in Fig. 4 takes different values ​​depending on the selected pattern of the drive units 13a to 13c. This is because the mold 80 is located at the center of the underside of the slide 12, and therefore when pressure is applied to the center of the slide 12, the effect of bending the slide 12 into an arc is reduced, whereas when pressure is applied to the edge of the slide 12, the effect of bending the slide 12 into an arc is increased.

[0033] FIG. 5 is a graph illustrating the relationship between die size and the amount of deflection of the slide and lower frame. The graph lines labeled "Dies 1-3" in FIG. 5 represent the characteristic lines when three dies 80 of different sizes are set in the press apparatus 1. The amount of deflection in FIG. 5 varies depending on the load (e.g., proportionally), but even when the load is the same, it also takes on different values ​​depending on the size of the die 80. This is because the range over which the lower frame 11 and slide 12 receive a reaction force from the die 80 varies depending on the size of the die 80, and the effect of the lower frame 11 and slide 12 bending in an arc varies depending on the size of that range. The size of the die 80 that affects the amount of deflection in FIG. 5 is mainly width and length (depth), but height may also have an effect.

[0034] <Deflection calculation formula> The relationship between the selection pattern of the drivers 13a to 13c and the amount of deflection shown in Fig. 4 is a characteristic when the size of the die 80 is fixed, and if the size of the die 80 changes, the characteristic shown in Fig. 4 also changes. Furthermore, the relationship between the die size and the amount of deflection shown in Fig. 5 is a characteristic when the selection pattern of the drivers 13a to 13c is fixed, and if the selection pattern of the drivers 13a to 13c changes, the characteristic shown in Fig. 5 also changes. In other words, if the selection pattern of the drivers 13a to 13c is not fixed and the size of the die 80 is not fixed, the amount of deflection of the press apparatus 1 changes depending on these multiple parameters.

[0035] The control unit 31 has the following calculation formula (1) in advance to calculate the overall deflection ΔX of the press device 1, which changes depending on the above-mentioned multiple parameters. The overall deflection ΔX corresponds to the amount converted into the deviation amount of the distance between the dies.

number

[0036] Formula (1) takes n, A, B, H, W, and ΔT as input parameters and outputs the overall deflection amount ΔX (the overall change in the distance between the dies due to deflection). The deflection amount ΔX corresponds to the correction value for the movement amount of the slide 12.

[0037] The control unit 31 may have a data table showing the relationship between the above input parameters and the overall amount of deflection ΔX, instead of the calculation formula (1).

[0038] <Example of formula derivation> Next, an example of deriving each coefficient in formula (1) will be described. Coefficients a1 to a3, b1 to b3, c1 to c3, d1 to d3, and e1 to e3 can be derived from multiple measured values ​​or multiple analytical values ​​by regression analysis (specifically, a statistical regression analysis method such as multiple regression analysis).

[0039] First, an example of deriving the coefficients "a1, b1, c1, d1, e1" in equation (2-1) through regression analysis is shown. To perform this regression analysis, a data set is prepared that shows the actual measured values ​​or analytical values ​​of the overall deflection amount ΔX when the mold width A, mold length B, mold height H, and load W are changed to multiple values. However, the selected pattern of the drive units 13a to 13c is set to one center one, and the temperature of the mold 80 is set to the reference temperature. A numerical analysis method such as FEM (Finite Element Method) analysis can be applied to obtain the deflection amount ΔX as an analytical value. When the temperature is set to the reference temperature, "-H × α × ΔT" in equation (2-1) becomes zero.

[0040] FIG. 6 is an example of a data set for deriving the calculation formula. As shown in FIG. 6, it is preferable that the data set 41 has each parameter distributed with little bias. Data set 41 includes the deflection amount ΔX that occurs when three loads W are set (10 MN, 20 MN, and 30 MN); three die widths A are set (500 mm, 800 mm, and 1200 mm); three die lengths B are set (300 mm, 400 mm, and 500 mm); and three die heights H are set (200 mm, 250 mm, and 300 mm). Because the amount of data is enormous, some of the data is omitted in FIG. 6, and only the data for a die height H of 200 mm is shown.

[0041] In the regression equation, as shown in equation (2-1), for the terms including variables A and B, a term inversely proportional to variables A and B is used. This is because the larger the mold width A and mold length B, the smaller the deflection. In the regression equation, for the terms including variable H, a term proportional to variable H is used. This is because the larger the mold height H, the greater the amount of deflection according to the load. Then, by performing multiple regression analysis using the above data set and the regression equation, the coefficients "a1, b1, c1, d1, e1" can be derived.

[0042] The same applies when deriving the coefficients "a2, b2, c2, d2, e2" in equation (2-2) through regression analysis. In this case, the selection pattern for the actuators 13a to 13c is set to two, left and right, and a data set is prepared under similar conditions. In this case, since the maximum load is greater than when there is one actuator, it is advisable to prepare a data set with values ​​corresponding to the maximum load, such as three loads W: 20 MN, 40 MN, and 60 MN. Then, by performing a similar multiple regression analysis, the coefficients "a2, b2, c2, d2, e2" can be derived. Similarly, when the selection pattern for the actuators 13a to 13c is three, the coefficients "a3, b3, c3, d3, e3" in equation (2-3) can be derived using a similar method.

[0043] The above-described regression equation is merely an example. The regression equation may include terms that are more suited to the characteristics, or a simplified regression equation may be applied by omitting terms that do not have a significant effect.

[0044] Next, the coefficient α will be explained. "-H×α×ΔT" in the formulas (2-1) to (2-3) is a correction term for deflection due to temperature. The coefficient α is the thermal expansion coefficient of the material that constitutes the mold 80. When the mold 80 becomes hot due to preheating in advance during hot forming or warm forming, the height of the mold 80 increases due to thermal expansion, reducing the distance between the molds. This deflection (the amount of reduction in the distance between the molds) is calculated as ΔX S The deflection ΔX Sis substantially independent of the mold width A, mold length B, and the selected pattern of the drive units 13a to 13c, and is substantially determined by the mold height H, the temperature change ΔT (operating temperature - reference temperature: room temperature), and the thermal expansion coefficient α. Therefore, if the mold height after the temperature rise is denoted as H2, the mold height before the temperature rise (= reference temperature) as H1 (= H), and the change in mold height as ΔH, then it can be expressed as in the following formula (3). ΔX S = ΔH = -(H2-H1) = -H1×α×ΔT …(3) Therefore, the correction terms for the deflection due to temperature in the formulas (2-1) to (2-3) are as described above.

[0045] The deflection amount ΔX is determined as a correction value for the movement amount of the slide 12. The deflection amount ΔX changes based on the selection pattern of the multiple drive units 13a to 13c, as well as the size and temperature of the mold 80, and represents the actual deflection amount with high precision. Therefore, by correcting the movement amount of the slide 12 using the deflection amount ΔX, more precise press working is possible.

[0046] <Example of operation> Next, the operation of the press apparatus 1 will be described. FIG. 7 is a flowchart of the press process executed by the control unit. The program for the press process is stored in the memory unit 31a of the control unit 31. When the press process is started, before the start of the press operation, the control unit 31 performs an input process for initial data (step S1). The initial data includes the size (width, length, height) of the mold 80, the selection pattern of the drive units 13a to 13c, and the required value of the mold-to-mold distance at the completion of molding. This initial data may be input by an operator via the input unit 33, or the size of the mold 80 may be automatically measured by the control unit 31 using a digital camera or the like. The selection pattern of the drive units 13a to 13c and the required value of the mold-to-mold distance at the completion of molding may also be input by the operator, or may be automatically selected by the control unit 31 using artificial intelligence or the like, or default values ​​may be set.

[0047] The required mold distance at the end of molding is related to the thickness of the molded product. By setting this required value large, pressurization will end when the mold distance is large, resulting in a thick molded product. By setting this required value small, pressurization will end when the mold distance is small, resulting in a thin molded product.

[0048] After the initial data is input, the control unit 31 then waits until a command to start pressing is received (step S2). During this time, the operator preheats the mold 80 if necessary, and sets the material to be processed in the mold 80. Then, when a command to start pressing is received, the control unit 31 reads the measured values ​​of the position sensor 21, temperature sensor 22, and load sensor 23 of the slide 12 (step S3), while driving the selected drive units 13a to 13c (step S4), and executes a loop process to lower the slide 12.

[0049] During the loop processing, the control unit 31 calculates the deflection amount ΔX using the above-mentioned calculation formula (1) (step S5), calculates the actual stroke amount of the slide 12 from the measurement value of the position sensor 21 and the calculated deflection amount ΔX (step S6), and displays the stroke amount on the display unit 32 (step S7). The stroke amount represents the actual mold-to-mold distance with high accuracy.

[0050] Furthermore, during the loop processing, the control unit 31 determines whether the stroke amount has reached the required die-to-die distance (step S8), and if it is determined that it has reached the required distance, stops the descent of the slide 12 (step S9), performs processing at the end of pressurization if necessary (step S10), and then raises the slide 12 (step S11), completing one press processing cycle.

[0051] The stroke amount of the slide 12 used in the determination in step S7 is a value that matches with high precision the actual inter-die distance that reflects the effects of deflection of the lower frame 11, slide 12, side frame 15, and die 80 of the press device 1. Therefore, by performing the above-described press process, the descent of the slide 12 is stopped at an inter-die distance that is closer to the required value, allowing for the production of a more precisely molded product.

[0052] As described above, the press apparatus 1 of this embodiment includes the slide 12, the plurality of drive units 13a to 13c that apply a load to the slide 12, and the control unit 31 that controls the amount of movement of the slide 12. According to this configuration, the control unit 31 controls the slide 12 to move down to a predetermined position, thereby realizing a press process that forms the workpiece.

[0053] Furthermore, the control unit 31 calculates a correction value (deflection amount ΔX) for the movement amount of the slide 12 and corrects the movement amount of the slide 12 using this correction value. The correction value varies based on the selection pattern of the multiple drive units 13a-13c (which of the multiple drive units 13a-13c is driven). In a press apparatus 1 having multiple drive units 13a-13c, one or more of which are selected and driven, the degree of deflection of the slide 12 and the upper frame 14 during press operation varies depending on the selection pattern of the drive units 13a-13c. Therefore, by adopting the correction value described above, an appropriate correction value can be applied according to the selection pattern of the drive units 13a-13c. Therefore, it is possible to prevent the actual die-to-die distance from deviating from the controlled die-to-die distance due to deflection of the press apparatus 1, enabling precise press molding.

[0054] Furthermore, according to the press apparatus 1 of this embodiment, the above-mentioned correction value (deflection amount ΔX) also changes based on the size of the die 80. In a press apparatus 1 that is wide or deep, the degree of deflection of the slide 12 and the lower frame 11 during pressing operation changes depending on the size of the die 80. Therefore, by using the above-mentioned correction value, it is possible to apply an appropriate correction value according to the size of the die 80. Therefore, it is possible to prevent the actual die-to-die distance from deviating from the controlled die-to-die distance due to deflection of the press apparatus 1, enabling precise press molding.

[0055] Furthermore, according to the press apparatus 1 of this embodiment, the above-mentioned correction value (deflection amount ΔX) also changes based on the temperature of the die 80. By using such a correction value, even when the die 80 thermally expands during hot forming or warm forming, an appropriate correction value corresponding to the thermal expansion can be applied. Therefore, it is possible to prevent the actual die-to-die distance from deviating from the controlled die-to-die distance due to deflection of the press apparatus 1 including the die 80, thereby enabling precise press forming.

[0056] Furthermore, the press apparatus 1 of this embodiment is provided with temperature sensors 22a and 22b that measure the temperature of the die 80 and send information about the measured temperature to the control unit 31. Therefore, the control unit 31 can determine a correction value for the amount of movement of the slide 12 (amount of deflection ΔX) based on the temperature information sent from the temperature sensors 22a and 22b.

[0057] Furthermore, according to the press apparatus 1 of this embodiment, the control unit 31 has a calculation formula or a data table that receives at least the load W (load value) as an input and outputs a correction value (deflection amount ΔX) for the amount of movement of the slide 12. The calculation formula or data table outputs a correction value that reflects the deflection of the lower mold 81, the deflection of the upper mold 82, the deflection of the lower frame 11, the deflection of the slide 12, the elongation of the side frame 15, and the thermal expansion of the mold 80. Therefore, the control unit 31 can obtain an appropriate correction value through calculation processing that imposes a low load, thereby achieving precise press forming.

[0058] Furthermore, according to the press apparatus 1 of this embodiment, the above-described calculation formula or data table receives as input information (selection pattern) indicating which of the multiple drive units 13a to 13c is being driven, the size of the die 80, and the temperature of the die 80, and outputs a correction value (deflection amount ΔX) for the amount of movement of the slide 12. Therefore, the control unit 31 can obtain an appropriate correction value according to the selection pattern of the multiple drive units 13a to 13c, the size of the die 80, and the temperature of the die 80 through calculation processing with a low load, thereby achieving precise press molding.

[0059] Furthermore, the press device 1 of this embodiment is provided with a position sensor 21 that measures the position of the slide 12, and the stop position of the slide 12 during the press operation is controlled based on the measurement value of the position sensor 21 and the above-mentioned correction value (deflection amount ΔX). Therefore, the accuracy of the distance between the dies at the end of press molding is improved, and a precise thickness of the molded product can be achieved.

[0060] Furthermore, the press apparatus 1 of this embodiment is further provided with a display unit 32 that displays the corrected movement amount (stroke amount) of the slide 12. Therefore, the operator can accurately recognize the stroke amount of the slide 12 from the display, and a press process that is easy for the operator to understand can be realized.

[0061] The above describes an embodiment of the present invention. However, the above embodiment is merely an example of a press apparatus according to the present disclosure. For example, the press apparatus 1 has multiple drive units 13a-13c, and one of the drive units can be selected. However, the press apparatus 1 may have a single drive unit or a single drive unit selection pattern. In this case, the correction value (deflection amount ΔX) calculated by the control unit 31 may vary based on the size of the mold 80, the temperature of the mold 80, or both, rather than based on the selection pattern of the drive units 13a-13c. Furthermore, in the above embodiment, the size of the mold 80 includes the height of the mold 80. However, the height may be omitted because the effect of height is relatively small. Furthermore, in the above embodiment, three drive units 13a-13c are shown aligned horizontally. However, the number and arrangement of the drive units can be varied. Furthermore, the drive units are not limited to hydraulic ram cylinders; other hydraulic drive units or mechanical drive units may be used. In addition, the details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0062] 1 Press equipment 11 Lower frame 12 slides 13a~13c Drive unit 14 Upper frame 15 Side frame 21 Position Sensor 22, 22a, 22b temperature sensors 23 Load sensor 31 Control Unit 31a Storage section 32 Display section 33 Input section 41 datasets 80 molds 81 Lower mold 82 Upper mold

Claims

1. Slides and a plurality of drive units that apply loads to the slide; a control unit that calculates a correction value for the amount of movement of the slide, The correction value changes depending on which of the plurality of driving units is driving. Press equipment.

2. The correction value further varies depending on the size of the mold. The press device according to claim 1.

3. An input unit that acquires the size of the mold and sends information about the size to the control unit. The press device according to claim 2.

4. The correction value further varies depending on the temperature of the mold. The press device according to claim 1.

5. Further provided is a temperature sensor that measures the temperature of the mold and sends information about the temperature to the control unit. The press device according to claim 4.

6. the control unit has a calculation formula or a data table that receives at least a load value as an input and outputs a correction value for the movement amount, the calculation formula or the data table outputs a correction value for the movement amount that reflects any one or more of the deflection of the lower mold, the deflection of the upper mold, the deflection of the lower frame that supports the lower mold, the deflection of the slide, the extension of the side frame, and the thermal expansion of the mold. The press device according to claim 1.

7. the calculation formula or the data table receives as input, in addition to the load value, information indicating which of the plurality of driving units is driving, the size of the mold, and the temperature of the mold, and outputs a correction value for the movement amount. The press device according to claim 6.

8. a position sensor for measuring the position of the slide; a stop position of the slide during a pressing operation is controlled based on the measurement value of the position sensor and the correction value; The press device according to claim 1.

9. further comprising a display unit that displays the corrected movement amount; The press device according to claim 1.

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