Plate processing machine and plate processing method

Abstract

To provide a plate material processing machine which suppresses occurrence of plate materials that cannot obtain desired processing dimensions.SOLUTION: A plate material processing machine 10 comprises: at least three or more clamps 12 comprising one end side clamp (first clamp 12a) arranged on one end side in an X axis direction and the other end side clamp (third clamp 12c) arranged on the other end side in the X axis direction, which are installed on a carriage 11 along the X axis direction and respectively grip an end Wa of a plate material W as a work-piece, and an inter-arrangement clamp (second clamp 12b) arranged between the one end side clamp and the other end side clamp; a plurality of sensors 14 which detect a gripping state of the plate material W by the clamp 12; and a control part 15 which does not start processing for the plate material W when it is determined that there is the plate material W at a normal gripping position with regard to only the one end side clamp and the inter-arrangement clamp on the basis of outputs of the plurality of sensors 14.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a plate processing machine and a plate processing method. [Background technology]

[0002] In conventional plate processing machines such as punch presses, a plate as a workpiece is gripped by multiple clamps and moved to a processing position. When a plate whose main plane is parallel to the XY plane and long in the X-axis direction is the workpiece, the plate may have a camber that is convex in either the positive or negative direction of the Y-axis. This camber causes the plate to become misaligned with the X-axis when held by the clamps. If the misalignment is significant, it becomes difficult to maintain high accuracy in the dimensions of hole formation positions and other measurements relative to the edge of the plate in the Y-axis direction, i.e., to minimize variations in accuracy. In response to this, Patent Document 1 discloses a technology related to a plate processing machine in which a plate is pressed against clamps during re-gripping to prevent misalignment of the plate from becoming misaligned with the X-axis when the plate is long in the X-axis direction and has a convex camber toward the clamp. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-176574 Summary of the Invention [Problem to be solved by the invention]

[0004] In the plate processing machine disclosed in Patent Document 1, even if the plate is pressed toward the clamps each time it is re-clamped, it may be difficult to prevent the plate from becoming misaligned with the X axis, for example, when the distance between adjacent clamps in the X axis direction is short. In other words, in such a plate processing machine, even if the specific operation of pressing the plate toward the clamps is performed, the plate may move to the processing step with the plate still misaligned with the X axis, and as a result, the desired processing dimensions may not be obtained. [Means for solving the problem]

[0005] A plate processing machine according to one aspect of the present invention includes a carriage that moves in the X-axis direction and the Y-axis direction relative to a processing position, at least three clamps that are installed on the carriage along the X-axis direction and grip each end of a plate material as a workpiece, the three clamps being one end clamps arranged on one end side of the X-axis direction, an other end clamps arranged on the other end side of the X-axis direction, and an inter-array clamp arranged between the one end clamps and the other end clamps, a plurality of sensors that are installed on each of the clamps and detect the gripping state of the plate material by the clamps, and based on the outputs of the plurality of sensors, When it is determined that the plate material is in a normal gripping position only with respect to the one end clamp and the inter-array clamp, the processing of the plate material is not started, and a control unit that starts processing the plate material when it is determined that the plate material is in a normal gripping position only for the one end clamp and the other end clamp.

[0006] A plate processing method according to one aspect of the present invention includes a step of determining whether the plate is in a normal gripping position in each of at least three clamps installed along the X-axis direction on a carriage that moves in the X-axis direction and the Y-axis direction relative to a processing position when the plate is gripped at an end portion thereof by at least three clamps; when it is determined that the plate material is in a normal gripping position only for the one-end clamp disposed at one end in the X-axis direction and the inter-array clamp disposed between the one-end clamp and the other-end clamp disposed at the other end in the X-axis direction, it is determined not to start a processing process for the plate material; and a step of deciding to start a processing process for the plate material when it is determined that the plate material is in a normal gripping position only for the one-end clamp located at one end in the X-axis direction and the other-end clamp located at the other end in the X-axis direction.

[0007] In the above-described plate processing machine or plate processing method, when the control unit determines that the plate is in the correct gripping position only with respect to the one-end clamp and the inter-array clamp, it recognizes that the plate has warped in a convex shape toward the clamped side in the Y-axis direction. Thereafter, the control unit does not start processing the plate having such warpage, thereby avoiding a situation in which the desired processing dimensions cannot be obtained in the plate. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a plate processing machine and a plate processing method that suppress the occurrence of plate materials that do not have the desired processing dimensions. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic plan view showing the configuration of a plate processing machine 10 according to this embodiment. [Figure 2] FIG. 2 is a partially enlarged view of the installation portion of the clamp 12 shown in FIG. [Figure 3] FIG. 3 is a flowchart showing the plate material processing steps according to this embodiment. [Figure 4] FIG. 4 is a schematic plan view illustrating the relationship between three gripping patterns and the warpage of the plate material W corresponding to each gripping pattern. [Figure 5] Figure 5 is a schematic plan view showing the state in which, after step S107, the second clamp 12b is moved in a direction away from the plate material W, and the end Wa of the plate material W is pressed against the abutment portion 62 provided on each clamp 12. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a plate processing machine and a plate processing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same parts are given the same reference numerals, and further description will be omitted. In this embodiment, the X-axis direction and the Y-axis direction are defined as two axial directions that are orthogonal to each other on a horizontal plane.

[0011] 1 is a schematic plan view showing the configuration of a plate processing machine 10 according to this embodiment. The plate processing machine 10 may be, for example, a punch press that performs punch hole processing at set positions on a workpiece.

[0012] The plate material processing machine 10 comprises a carriage 11 that moves in the X-axis and Y-axis directions relative to the processing position PP; at least three clamps 12 that are installed on the carriage 11 along the X-axis direction and each grip an end Wa of a plate material W as a workpiece, including a one-end clamp arranged at one end side in the X-axis direction, an other-end clamp arranged at the other end side in the X-axis direction, and an inter-array clamp arranged between the one-end clamp and the other-end clamp; a plurality of sensors 14 installed on each of the clamps 12 and that detect the gripping state of the plate material W in the clamps 12; and a control unit 15 that does not start processing the plate material W when it determines, based on the output of the plurality of sensors 14, that the plate material W is in a normal gripping position only for the one-end clamp and the inter-array clamp.

[0013] Here, the plate material W assumed as the workpiece in this embodiment is a long sheet metal. For example, the plate material W may be a color steel plate having a length L of about 4000 mm, a width of about 100 mm in the main plane, and a thickness of about 0.8 mm. In FIG. 1 and the following FIG. 2, the plate material W is schematically indicated by a two-dot chain line.

[0014] The carriage 11 is included in a positioning unit 20 that positions the plate material W in the X-axis and Y-axis directions. The positioning unit 20 includes, for example, a carriage base 21, an X-axis drive mechanism 22, and a Y-axis drive mechanism 23. The carriage base 21 is a member whose longitudinal direction is the X-axis direction, and supports the carriage 11 so that it can move freely along the X-axis direction.

[0015] The X-axis drive mechanism 22 is a drive mechanism for moving the carriage 11 along the X-axis direction. The X-axis drive mechanism 22 includes an X-axis motor 24 installed on one end side of the carriage base 21, an X-axis ball screw 25 extending in the X-axis direction and rotated by the output of the X-axis motor 24, and a nut member 26 engaged with the X-axis ball screw 25 and fixed to the carriage 11.

[0016] The Y-axis drive mechanism 23 is a drive mechanism for moving the carriage base 21 along the Y-axis direction. The Y-axis drive mechanism 23 includes a Y-axis motor 27 installed on the main body frame 16, a Y-axis ball screw 28 that extends in the Y-axis direction and rotates by the output of the Y-axis motor 27, and a nut member 29 that engages with the Y-axis ball screw 28 and is fixed to the carriage base 21.

[0017] In connection with the installation of the carriage base 21, the plate processing machine 10 also includes a main body frame 16, a table unit 30, a processing unit 40, and a pair of plate holding units 50. The main body frame 16 supports the positioning unit 20, the table unit 30, the processing unit 40, and the plate holding units 50.

[0018] The table unit 30 supports the plate material W on the pass line (support height position or conveying height position). The table unit 30 includes, for example, a center fixed table 31, a pair of movable tables 32, and a pair of side fixed tables 33. The center fixed table 31 is fixed to the main body frame 16. The movable table 32 is connected to the carriage base 21 and is movable in the Y-axis direction integrally with the carriage base 21. Each side fixed table 33 is installed on one of the pair of movable tables 32 along the X-axis direction.

[0019] One of the side fixed tables 33 is provided with a locating pin 34 used when setting the plate material W at the origin position in the X-axis direction. The locating pin 34 is installed on one of the side fixed tables 33 in the end region closest to the plate material W loading section in the X-axis direction. The locating pin 34 has an abutment surface 34a against which an end Wb on one end side in the X-axis direction of the plate material W abuts when setting the plate material W at the origin position in the X-axis direction for origin positioning (see FIG. 2). The abutment surface 34a is parallel to the Y-axis direction and is located at the origin position in the X-axis direction.

[0020] The machining unit 40 performs various machining operations, such as punching holes, on the sheet material W transported along the pass line. The machining unit 40 includes, for example, an upper turret 41 and a lower turret (not shown) that vertically faces the upper turret 41. The upper turret 41 is rotatably fixed to the upper part of the main frame 16 and holds a plurality of punch dies 42. The lower turret is rotatably fixed to the lower part of the main frame 16 and holds a plurality of die dies. Any punch dies 42 and any die dies are appropriately indexed to a machining position PP by rotation of the upper turret 41 and the lower turret. Furthermore, the machining unit 40 includes, for example, a striker (not shown) that presses the punch dies 42 indexed to the machining position PP from above toward the die dies below.

[0021] When processing the workpiece W, the workpiece holding unit 50 presses and holds the workpiece W against the center fixed table 31 so that it cannot move in the X-axis and Y-axis directions. In this embodiment, two workpiece holding units 50 are installed side by side in the X-axis direction. Each workpiece holding unit 50 includes, for example, a holding pad 52 that moves vertically by a cylinder 51 fixed to the main frame 16, and a support pad (not shown) that faces the holding pad 52 in the vertical direction. The workpiece holding unit 50 restricts the movement of the workpiece W by sandwiching the workpiece W between the holding pad 52 and the support pad.

[0022] Regarding at least three clamps 12, in this embodiment, it is assumed that three clamps 12, namely, a first clamp 12a, a second clamp 12b, and a third clamp 12c, are installed on the carriage 11. The first clamp 12a, the second clamp 12b, and the third clamp 12c are arranged in order from one end of the carriage 11 in the X-axis direction. In this case, the first clamp 12a is a "one-end clamp" arranged at one end in the X-axis direction. The third clamp 12c is an "other-end clamp" arranged at the other end in the X-axis direction. The second clamp 12b is an "inter-array clamp" arranged between the first clamp 12a and the third clamp 12c.

[0023] 2 is a partially enlarged view of an installation portion of the clamp 12 shown in FIG. 1. Each clamp 12 has an upper clamp claw 60 and a lower clamp claw 61. The upper clamp claw 60 and the lower clamp claw 61 grip and release the end Wa of the plate material W that faces the carriage 11 in the Y-axis direction by opening and closing the tip end portion on the side opposite to the side connected to the carriage base 21 in the Y-axis direction. Each clamp 12 also has an abutting portion 62 against which the end Wa of the plate material W abuts when setting the plate material W at the origin position in the Y-axis direction for origin positioning. Each clamp 12 is connected to the carriage 11 via a clamp base 63.

[0024] In this embodiment, the position of each clamp 12 is defined based on the end portion Wb on one end side where the plate material W with a length L in the X-axis direction is gripped by each clamp 12 and abuts against the abutting surface 34a of the locating pin 34 when the plate material W is carried in. The clamp position is taken as the center of the width of each clamp 12 in the X-axis direction. The first clamp 12a is located at a position with a length L1 in the X-axis direction from the end portion Wb. The second clamp 12b is located at a position with a length L2 in the X-axis direction from the end portion Wb. Also, the third clamp 12c is located at a position with a length L3 in the X-axis direction from the end portion Wb. That is, there is a relationship of L1 < L2 < L3 among the lengths L1 to L3. By changing the positions of the respective clamps 12 along the X-axis direction on the carriage 11, the lengths L1 to L3 that define the positions of the respective clamps 12 can be adjusted as appropriate.

[0025] Since the clamp driving unit 13 moves only the inter-array clamps along the Y-axis direction, in this embodiment, it is installed only for the second clamp 12b. In this embodiment, the clamp driving unit 13 integrally moves the second clamp 12b by moving the clamp base 63 connecting the second clamp 12b in the Y-axis direction. The driving mechanism employed as the clamp driving unit 13 is not particularly limited as long as it can move the inter-array clamps along at least the Y-axis direction. For example, a motor may be used, or a hydraulic or pneumatic cylinder may be used.

[0026] Since the sensors 14 are installed on each of the clamps 12, there are three sensors in this embodiment. The first sensor 14a is installed on the first clamp 12a. The second sensor 14b is installed on the second clamp 12b. Also, the third sensor 14c is installed on the third clamp 12c. In this embodiment, each sensor 14 is attached to the corresponding clamp 12. However, instead of attaching the sensor 14 to the clamp 12, it may be attached to, for example, the corresponding clamp base 63 or the carriage 11.

[0027] Furthermore, the sensor 14 detecting the gripping state of the workpiece W by the clamp 12 means that the sensor 14 detects whether the clamp 12 is gripping the end Wa of the workpiece W at a preset normal gripping position. Here, when the workpiece W is not gripped at the normal gripping position, it is assumed that the end Wa of the workpiece W is not gripped, or that the end Wa of the workpiece W is gripped but not in a state sufficient to maintain stability, for example.

[0028] In this embodiment, the sensor 14 is a butting sensor that turns on its output when it butts against the plate material W when the plate material W is in the normal gripping position. The butting sensor is attached to the clamp 12 in a position such that when the plate material W is gripped by the clamp 12, the detection end faces the end Wa of the plate material W and can be displaced along the Y-axis direction.

[0029] The control unit 15 controls the operation of the plate processing machine 10 based on input instructions from an operator and processing programs. The control unit 15 may be a computer equipped with a CPU, an information storage device, etc. The plate processing machine 10 may also be equipped with an input / output device 17 equipped with an NC screen such as a touch panel, and an alarm device 18 that emits an alarm sound or light to the outside. In this case, the control unit 15 is electrically connected to the input / output device 17 and the alarm device 18.

[0030] The control unit 15 is also connected to each component related to the drive system and measurement system included in the plate processing machine 10, and can execute the plate processing step (plate processing method) according to this embodiment. For example, the control unit 15 is electrically connected to the first sensor 14a, the second sensor 14b, and the third sensor 14c, and can receive outputs from each of the sensors 14. The control unit 15 is also electrically connected to the clamp drive unit 13, and can send drive commands to the clamp drive unit 13.

[0031] Next, the operation of the plate processing machine 10 including the plate processing step according to this embodiment will be described.

[0032] FIG. 3 is a flowchart showing a plate material processing step according to the present embodiment. When the plate material processing step is started in the plate material processing machine 10, as the origin positioning of the plate material W, the plate material W is set on the three clamps 12 of the first clamp 12a to the third clamp 12c (step S101). Here, the plate material W may be manually set on each clamp 12 by an operator, or may be automatically conveyed from the outside of the plate material processing machine 10 using a conveying mechanism or the like not shown in the figure and automatically set on the three clamps 12. At this time, the control unit 15 drives the Y-axis motor 27 to move the carriage base 21, or drives the X-axis motor 24 to move the carriage 11, so as to position the carriage 11 on the origin position side in advance. Next, with the posture of the plate material W in the thickness direction being approximately vertical, the end Wa of the plate material W is abutted against the abutting portion 62 provided on each clamp 12. On the other hand, the end Wb of the plate material W is abutted against the abutting surface 34a provided on the locating pin 34. After these abutments are completed, the control unit 15 causes each clamp 12 to grip the plate material W.

[0033] Next, the control unit 15 determines whether the length L of the plate material W in the X-axis direction is longer than a preset length L3 as the length from the end Wb to the third clamp 12c (step S102). Here, the control unit 15 may obtain the value of the length L of the plate material W by referring to a processing program stored in advance.

[0034] If the control unit 15 determines in step S102 that the length L of the plate material W is shorter than the length L3 related to the third clamp 12c (NO), it determines the current position of the plate material W as the origin position, and then starts the processing (step S103). The case where the length L is shorter than the length L3 (L < L3) is the case where the plate material W is gripped only by the two clamps 12 of the first clamp 12a and the second clamp 12b. In this case, even if a warp (camber) as exemplified below occurs in the plate material W, the warp amount is considered to be within an allowable range that can maintain the dimensional accuracy during the processing. The processing steps according to step S103 will be described in detail below.

[0035] On the other hand, if the control unit 15 determines in step S102 that the length L of the workpiece W is longer than the length L3 of the third clamp 12c (YES), it then causes each sensor 14 to detect the state of gripping of the workpiece W by each clamp 12 (step S104). A case where the length L is longer than the length L3 (L>L3) is when the workpiece W is gripped by three clamps 12, the first clamp 12a to the third clamp 12c.

[0036] Next, the control unit 15 determines which of the following three preset gripping patterns the gripping pattern corresponds to, based on each of the detection results acquired in step S104 (step S105).

[0037] 4 is a schematic plan view illustrating the relationship between three gripping patterns and the corresponding warpage of the plate material W. Here, warpage of the plate material W refers to deformation of the plate material W that convexly extends in either direction along the Y-axis when the thickness direction of the plate material W is set vertically and the longitudinal direction of the plate material W is roughly parallel to the X-axis. Table 1 shows the output of each sensor 14 for each clamp 12 corresponding to each gripping pattern.

[0038] [Table 1]

[0039] FIG. 4(a) illustrates a case where the gripping pattern is the first pattern shown in Table 1. When the gripping pattern is the first pattern, the workpiece W is not warped and the end portion Wa of the workpiece W is parallel to the X-axis, so the workpiece W may be subsequently processed. However, the absence of warping in the workpiece W does not necessarily mean that the workpiece W is completely warped, but rather means that the outputs of all sensors 14 are ON in step S104. When the outputs of all sensors 14 are ON, the workpiece W is gripped in the correct gripping positions by all of the clamps 12, which are positioned differently in the X-axis direction. Therefore, the workpiece W is generally considered to be free of warping. In other words, the control unit 15 can determine that the gripping pattern is the first pattern based on the detection result that the outputs of all sensors 14, the first sensor 14a to the third sensor 14c, are ON.

[0040] FIG. 4(b) illustrates the case where the gripping pattern is the second pattern. When the gripping pattern is the second pattern, the workpiece W has a convex warp toward the side where the processing position PP is set in the Y-axis direction. Hereinafter, the convex shape toward the side where the processing position PP is set in the Y-axis direction as shown in FIG. 4(b) is referred to as the "first convex shape." When the workpiece W has a first convex warp, only the clamps 12 arranged at both ends in the X-axis direction, i.e., the first clamp 12a, which is the one-end clamp, and the third clamp 12c, which is the other-end clamp, grip the workpiece W at their normal gripping positions. On the other hand, the distance c1 between the abutment portion 62 of the second clamp 12b, which is the inter-array clamp, and the end Wa of the workpiece W becomes large, and the second clamp 12b cannot grip the workpiece W at its normal gripping position. In this case, the outputs of the first sensor 14a and the third sensor 14c are ON, but the output of the second sensor 14b is OFF. In other words, the control unit 15 can determine that the gripping pattern is the second pattern based on the detection result that the outputs of the first sensor 14a and the third sensor 14c are ON and the output of the second sensor 14b is OFF.

[0041] FIG. 4(c) illustrates a case where the gripping pattern is the third pattern. When the gripping pattern is the third pattern, the workpiece W has a warp that is convex toward the side where the clamp 12 is installed in the Y-axis direction. Hereinafter, the convex shape toward the side where the clamp 12 is installed in the Y-axis direction as shown in FIG. 4(c) is referred to as the "second convex shape." When the workpiece W has a warp of the second convex shape, only the first clamp 12a, which is the one-end clamp, and the second clamp 12b, which is the inter-array clamp, grip the workpiece W in the correct gripping position. On the other hand, the distance c2 between the abutment portion 62 of the third clamp 12c, which is the other-end clamp, and the end Wa of the workpiece W becomes large, and the third clamp 12c cannot grip the workpiece W in the correct gripping position. In this case, the outputs of the first sensor 14a and the second sensor 14b are ON, but the output of the third sensor 14c is OFF. In other words, the control unit 15 can determine that the gripping pattern is the third pattern based on the detection result that the outputs of the first sensor 14a and the second sensor 14b are ON and the output of the third sensor 14c is OFF.

[0042] Here, as shown in FIG. 4(b), when the workpiece W has a first convex warp, only the first clamp 12a and the third clamp 12c grip the workpiece W in their normal gripping positions. The third clamp 12c is the clamp located at the other end of the clamps 12, the farthest from the first clamp 12a (length L3; see FIG. 2). In other words, when the workpiece W has a first convex warp, only the first clamp 12a and the third clamp 12c, which are spaced the widest apart from each other, grip the workpiece W. This minimizes overall misalignment of the workpiece W from being parallel to the X-axis. Therefore, when the workpiece W has a first convex warp, i.e., when the gripping pattern is the second pattern, processing such as punching holes may be continued. Similarly, when the gripping pattern is the first pattern, the workpiece W is considered to have almost no warp, and processing such as punching holes may be continued.

[0043] On the other hand, when the workpiece W has a second convex warp, only the first clamp 12a and the second clamp 12b grip the workpiece W in their normal gripping positions. The second clamp 12b is an inter-array clamp positioned at a length L2 (see FIG. 2) that is shorter than the length L3 to the third clamp 12c, relative to the first clamp 12a, which is the one-end clamp. In other words, when the workpiece W has a second convex warp, only the first clamp 12a and the second clamp 12b, which are spaced relatively close to each other, grip the workpiece W. Therefore, when the workpiece W has a second convex warp, the workpiece W becomes more misaligned with the X-axis as it moves from the end Wb toward the end Wc opposite the end Wb, compared to when the workpiece W has a first convex warp. Therefore, when the workpiece W has a second convex warp, i.e., when the gripping pattern is the third pattern, it is not desirable to continue processing.

[0044] Based on the definition of the gripping pattern as described above, if the control unit 15 determines in step S105 that the identified gripping pattern corresponds to the first pattern or the second pattern, the process proceeds to step S103.

[0045] On the other hand, when the control unit 15 determines in step S105 that the identified gripping pattern corresponds to the third pattern, it does not proceed to the processing step related to step S103, i.e., it does not start processing the workpiece W. Specifically, the control unit 15 determines not to start the processing step related to the workpiece W, and displays, for example, on the NC screen of the input / output device 17, that the processing step related to step S103 has not been started (step S106). After step S106, the control unit 15 proceeds to step S107.

[0046] Next, the control unit 15 releases all the clamps 12 to release the grip of the plate material W (step S107). After step S107, the control unit 15 proceeds to step S108.

[0047] Figure 5 is a schematic plan view showing the state in which, after step S107, the second clamp 12b is moved in a direction away from the plate material W, and the end Wa of the plate material W is pressed against the abutment portion 62 provided on each clamp 12.

[0048] Next, the control unit 15 drives the clamp driving unit 13 to move the second clamp 12b, which is the inter-array clamp, in a direction away from the plate material W (step S108). FIG. 5(a) corresponds to the operation in step S108 and shows a state in which the second clamp 12b, which was in the state shown in FIG. 4(c), has moved in a direction away from the plate material W. Here, the movement amount of the second clamp 12b is set at least to an extent that the end Wa of the plate material W does not come into contact with the abutment portion 62 of the second clamp 12b even when the end Wa is abutted against each abutment portion 62 in the next step S109.

[0049] Next, the workpiece W is again set in the three clamps 12, the first clamp 12a to the third clamp 12c (step S109). FIG. 5(b) corresponds to the operation in step S109 and shows a state in which the end Wa of the workpiece W is pressed against the abutment portion 62 of each clamp 12 in the state shown in FIG. 5(a). The procedure for setting the workpiece W in step S109 is the same as the procedure in step S101. For example, the workpiece W may be manually set in each clamp 12 by an operator who checks the display on the NC screen in step S106, or may be automatically set in the three clamps 12 using a conveying mechanism (not shown) or the like in response to an instruction from the control unit 15. Finally, the control unit 15 causes each clamp 12 to grip the workpiece W.

[0050] Next, the control unit 15 causes each sensor 14 to detect the state of gripping of the plate material W by the corresponding clamp 12, similar to step S104 (step S110).

[0051] Next, similarly to step S105, the control unit 15 determines which of the three preset gripping patterns the gripping pattern corresponds to based on each detection result acquired in step S110 (step S111).

[0052] If the control unit 15 determines in step S111 that the identified gripping pattern corresponds to the first pattern or the second pattern, the process then proceeds to a processing step in step S103.

[0053] The processing step in step S103 is a step of actually performing punch hole processing and the like at desired positions in the plate material W. In step S103, the control unit 15 moves the carriage 11 to position the plate material W with respect to the processing position PP, while causing the punch tool 42 indexed to the processing position PP to strike the die tool below. This allows the plate material processing machine 10 to perform punch hole processing at desired positions in the plate material W. Then, after the processing step is completed, the control unit 15 ends the series of plate material processing steps.

[0054] On the other hand, if the control unit 15 determines in step S111 that the identified gripping pattern corresponds to the third pattern, it then displays on the NC screen of the input / output device 17 that the process has not proceeded to the processing step related to step S103 (step S112). In this case, the warp of the plate material W is so large that it is difficult to prevent the plate material W from becoming misaligned with the X-axis simply by changing the gripping position of the plate material W. Therefore, after step S112, the control unit 15 issues an alarm to the plate material processing machine 10 (step S113), and then ends the series of plate material processing steps. Note that in step S113, the control unit 15 may cause the alarm device 18 to emit an alarm sound or light to warn the operator that it is not desirable to continue processing the plate material W currently being processed.

[0055] Next, the effects of the plate processing machine 10 and plate processing method according to this embodiment will be described.

[0056] First, the plate material processing machine 10 has at least three clamps: one-end clamps arranged at one end in the X-axis direction, another-end clamps arranged at the other end in the X-axis direction, and an inter-array clamp arranged between the one-end clamp and the other-end clamp. The plate material processing machine 10 also has a plurality of sensors 14 that detect the gripping state of the plate material W in the clamps 12. When the control unit 15 determines, based on the outputs of the plurality of sensors 14, that the plate material W is in a normal gripping position only for the one-end clamp and the inter-array clamp, it does not start processing the plate material W.

[0057] The plate material processing method according to this embodiment also includes a step (step S105) of determining whether the plate material W is in a normal gripping position in at least three or more clamps 12. The plate material processing method also includes a step (step S106) of deciding not to start a processing process for the plate material W when it is determined that the plate material W is in a normal gripping position only in the one-end clamps and the inter-array clamps among the at least three or more clamps 12.

[0058] In the above example where there are three clamps 12, the first clamp 12a corresponds to the one end clamp, the second clamp 12b corresponds to the inter-array clamp, and the third clamp 12c corresponds to the other end clamp.

[0059] When a workpiece W is elongated in the X-axis direction and its main plane is parallel to the XY plane when held by the clamps 12, the workpiece W may have a warp that is convex in either the positive or negative direction of the Y-axis. First, when the workpiece W has a first convex warp as shown in FIG. 4(b), only the one-end clamp (first clamp 12a) and the other-end clamp (third clamp 12c) hold the workpiece W in their normal holding positions. The other-end clamp is the clamp that is located farthest from the one-end clamp among the at least three clamps 12. In other words, when the workpiece W has a first convex warp, the workpiece W can be held only by the one-end clamp and the other-end clamp, which are spaced the widest apart from each other. Therefore, even if warping occurs in the plate material W, the overall deviation of the plate material W from being parallel to the X-axis can be kept small, so processing such as punching holes can be continued, just as in the case where it is determined that no warping has occurred in the plate material W.

[0060] However, when the plate material W has a second convex warp as shown in FIG. 4(c), only the one-end clamp (first clamp 12a) and the inter-array clamp (second clamp 12b) hold the plate material W in the correct holding positions. The inter-array clamp is a clamp among the at least three clamps 12 that is positioned at a position shorter than the distance to the other-end clamp when the one-end clamp is used as a reference. In other words, when the plate material W has a second convex warp, the plate material W is held only by the one-end clamp and the inter-array clamp, which are spaced relatively close to each other. Therefore, when the plate material W has a second convex warp, the deviation of the plate material W from being parallel to the X-axis increases from the end Wb toward the end Wc opposite the end Wb, compared to when the plate material W has a first convex warp. For this reason, when a second convex warp occurs in the plate material W, it becomes difficult to maintain with high precision the dimensions of the hole formation position, etc., based on the end Wa in the Y-axis direction, and it may not be desirable to continue processing.

[0061] In contrast, in the plate material processing machine 10 and plate material processing method according to this embodiment, when the plate material W is set in the clamps 12, the control unit 15 determines whether the plate material W is in the correct gripping positions in at least three or more clamps 12. Here, if the control unit 15 determines that the plate material W is in the correct gripping positions only in the one-end clamps and the inter-array clamps, it can recognize that warpage of the second convex shape has occurred in the plate material W. Then, if the control unit 15 determines that the plate material W is in the correct gripping positions only in the one-end clamps and the inter-array clamps, it does not start the processing process for the plate material W that has warpage of the second convex shape. Therefore, the plate material processing machine 10 and the plate material processing method according to this embodiment can prevent a situation in which the desired processing dimensions cannot be obtained from the plate material W.

[0062] As described above, according to the present embodiment, it is possible to provide a plate material processing machine 10 and a plate material processing method that suppress the occurrence of plate materials W that do not have the desired processing dimensions. By employing such a plate material processing machine 10 and plate material processing method, it becomes easier to maintain with high precision the dimensions of hole formation positions and the like relative to the end Wa of the plate material W in the Y-axis direction, in other words, it becomes easier to minimize variations in precision.

[0063] The plate material processing machine 10 may also include a clamp driving unit 13 that is installed on the carriage 11 and moves the inter-array clamp along the Y-axis direction. When the control unit 15 determines not to start processing the plate material W, it may drive the clamp driving unit 13 to move the inter-array clamp in a direction away from the plate material W.

[0064] In addition, the plate material processing method according to this embodiment may include a step (step S108) of moving the inter-array clamp in a direction away from the plate material W when it is decided not to start the processing process (step S103) on the plate material W.

[0065] When the control unit 15 determines that only the one-end clamps and the inter-array clamps are in the correct gripping positions for the workpiece W, it drives the clamp driver 13 to move the inter-array clamp away from the workpiece W, as shown in FIG. 5(a), before proceeding to processing. Then, when the workpiece W is reset in the clamps 12, only the one-end clamps and the other-end clamps grip the workpiece W in the correct gripping positions, as shown in FIG. 5(b). In other words, even if the workpiece W has warped in the second convex shape, the workpiece W can be gripped only by the one-end clamps and the other-end clamps 12, which ensure the widest spacing between the clamps 12, as in the case where the workpiece W has warped in the first convex shape. As a result, the overall deviation of the workpiece W from being parallel to the X-axis can be minimized.

[0066] According to the plate processing machine 10 and plate processing method, it is possible to prevent the plate W from becoming misaligned with the X axis.

[0067] In addition, in the plate processing machine 10, when the plate material W is pressed against the clamp 12 after the inter-array clamp has been moved in a direction away from the plate material W, the control unit 15 may again determine whether the plate material W is in a normal gripping position based on the output of the multiple sensors 14.

[0068] This determination corresponds to step S111 in the plate material processing step shown in Fig. 3. If it is determined that the gripping pattern is still the third pattern after the plate material W is reset in the clamps 12 (step S109), this means that a very large warp has occurred in the plate material W. Therefore, in the plate material processing machine 10, by determining again whether the plate material W is in a normal gripping position after the plate material W is reset in the clamps 12, it is possible to avoid in advance unnecessary processing of the plate material W that may ultimately be determined to be defective.

[0069] Furthermore, in the plate material processing machine 10, the sensor 14 may be a bumping sensor whose output is turned on when the sensor 14 bumps against the plate material W when the plate material W is in the normal gripping position.

[0070] According to the plate processing machine 10, the control unit 15 can recognize that the plate W is in a normal gripping position with a simple configuration and simple control.

[0071] Although the above description has been given as an example of the case where there are three clamps 12, there may be four or more clamps 12. For example, if there are four clamps 12, there will be two inter-array clamps, and a clamp driver 13 will be installed for each of the two inter-array clamps, and they will be controlled by the controller 15.

[0072] 3, the plate material processing step ends immediately after the processing step (step S103). However, when the plate material W is long as assumed in this embodiment, the plate material processing step may include a re-clamping step, in which the clamps 12 re-clamp the plate material W after the first processing step is completed, and then the second processing step may be performed.

[0073] In the plate processing process shown in FIG. 3 , after step S105, the control unit 15 displays on the NC screen of the input / output device 17 in step S106 that the process has not yet proceeded to the processing step related to step S103. In response to this, the control unit 15 may further display in step S106 a message prompting the operator to reset the plate W so that the gripping pattern changes from the third pattern to the second pattern. Alternatively, resetting the plate W to change the gripping pattern from the third pattern to the second pattern may be performed automatically using a conveying mechanism (not shown). Here, the method of changing the gripping pattern from the third pattern to the second pattern may involve, for example, symmetrically flipping the plate W around the X-axis after releasing the clamp in step S107, or rotating the plate W 180 degrees on a horizontal plane. After changing the gripping pattern in this way, the process proceeds to step S109.

[0074] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0075] 10 Plate processing machine 11 Carriage 12 Clamp 12a First clamp 12b Second clamp 12c Third Clamp 13 Clamp drive unit 14 sensors 14a First Sensor 14b Second Sensor 14c Third Sensor 15 Control Unit PP processing position W plate material Wa end

Claims

1. a carriage that moves in the X-axis direction and the Y-axis direction relative to the processing position; at least three clamps, each clamping an end of a plate material as a workpiece along the X-axis direction, including one-end clamps arranged at one end of the X-axis direction, another-end clamps arranged at the other end of the X-axis direction, and an inter-array clamp arranged between the one-end clamps and the other-end clamps; a plurality of sensors installed in each of the clamps to detect the state of gripping of the plate material by the clamps; Based on the outputs of the plurality of sensors, a control unit that does not start processing the plate material when it is determined that the plate material is in a normal gripping position only for the one end side clamp and the inter-array clamp, and starts processing the plate material when it is determined that the plate material is in a normal gripping position only for the one end side clamp and the other end side clamp.

2. a carriage that moves in the X-axis direction and the Y-axis direction relative to the processing position; at least three clamps, each clamping an end of a plate material as a workpiece along the X-axis direction, including one-end clamps arranged at one end of the X-axis direction, another-end clamps arranged at the other end of the X-axis direction, and an inter-array clamp arranged between the one-end clamps and the other-end clamps; a plurality of sensors installed in each of the clamps to detect the state of gripping of the plate material by the clamps; a control unit that does not start processing the plate material when it is determined that the plate material is in a normal gripping position only for the one-end clamps and the inter-array clamps based on outputs of the plurality of sensors; a clamp drive unit that is installed on the carriage and moves the inter-array clamp along the Y-axis direction, When the control unit determines not to start processing the plate material, the control unit drives the clamp drive unit to move the inter-array clamps in a direction away from the plate material.

3. a step of determining whether the plate material is in a normal gripping position in each of at least three clamps installed along the X-axis direction on a carriage that moves in the X-axis direction and the Y-axis direction relative to a processing position when the plate material is gripped at an end portion thereof by each of the at least three clamps; Among the at least three or more clamps, a step of deciding not to start a processing process for the plate material when it is determined that the plate material is in a normal gripping position only for the one-end clamp arranged at one end in the X-axis direction and the inter-array clamp arranged between the one-end clamp and the other-end clamp arranged at the other end in the X-axis direction, and a step of deciding to start a processing process for the plate material when it is determined that the plate material is in a normal gripping position only for the one-end clamp arranged at one end in the X-axis direction and the other-end clamp arranged at the other end in the X-axis direction.

4. a step of determining whether the plate material is in a normal gripping position in each of at least three clamps installed along the X-axis direction on a carriage that moves in the X-axis direction and the Y-axis direction relative to a processing position when the plate material is gripped at an end portion thereof by each of the at least three clamps; a step of deciding not to start a processing step for the plate material when it is determined that the plate material is in a normal gripping position only for one end clamp arranged at one end in the X-axis direction and an inter-array clamp arranged between the one end clamp and the other end clamp arranged at the other end in the X-axis direction among the at least three or more clamps; and if it is determined not to start a processing step on the plate material, moving the inter-array clamp in a direction away from the plate material.

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