Mold changing device and mold changing method

Abstract

To prevent a mold or the like from being broken when replacing the mold.SOLUTION: A mold replacement device 200 replaces a mold 10 for a press machine 100 that press-processes a work-piece W with the mold 10 (an upper mold 13) held on a holder 12. The mold replacement device 200 comprises: a gripper 210 that grips the mold 10; a control part 220 that moves the gripper 210 in a second direction that is opposite to a first direction which is a direction in which the mold 10 is inserted into the holder 12, with the mold 10 inserted into the holder 12 and with the mold 10 gripped with the gripper 210; a detecting part 230 that detects a load amount representing a degree of loads in the first direction acting on the gripper 210; and a determining part 240 that determines a holding situation of the mold 10 by the holder 12, on the basis of the load amount.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a mold changing device and a mold changing method. [Background technology]

[0002] Conventionally, press machines are known that clamp a workpiece between dies and perform press working such as forming on the workpiece. One such press machine is a press brake (bending machine) that performs bending on the workpiece. In a press brake, the arrangement and type of dies (one or both of an upper die and a lower die) may be changed in order to perform bending on the workpiece. The arrangement and type of dies for the press brake are changed by a die changing device. Patent Document 1 discloses a manipulator as a die changing device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5252837 Summary of the Invention [Problem to be solved by the invention]

[0004] In a press brake, a die is held by a holder provided on the ram. In some press brakes, a clamp is provided to fix the die to the holder when changing the die using a die changing device. However, if the clamp is not driven properly, it may cause damage to the die or the die changing device.

[0005] The present invention provides a mold changing device and a mold changing method that can prevent damage to molds, etc. when changing molds. [Means for solving the problem]

[0006] A die changing device according to one aspect of the present invention is a die changing device that changes dies for a press machine that presses a workpiece using dies held in a holder, and is equipped with a gripper that grips the die, a control unit that moves the gripper in a second direction that is opposite to the first direction that is the direction when the die is inserted into the holder when the die is inserted into the holder and when the die is gripped by the gripper, a detection unit that detects a load amount that represents the degree of load on the gripper in the first direction, and a determination unit that determines the holding status of the die by the holder based on the load amount. A die changing device according to one aspect of the present invention is a die changing device that changes dies for a press machine that presses a workpiece using dies held in a holder, and is equipped with a gripper that holds the die, a control unit that moves the gripper in a second direction that is opposite to the first direction in which the die is inserted into the holder when the die is inserted into the holder and when the die is held by the gripper, a detection unit that detects a load amount that represents the degree of load on the gripper in the first direction, and a judgment unit that judges the holding status of the die by the holder based on the load amount, wherein the control unit moves the gripper in the second direction after the holder has performed the operation of holding the die, and the judgment unit judges that the holder is not holding the die normally if the load amount is less than a predetermined threshold. A die changing device according to one aspect of the present invention is a die changing device that changes dies for a press machine that presses a workpiece using dies held in a holder, and is equipped with a gripper that grips the die, a control unit that moves the gripper in a second direction that is opposite to the first direction that is the direction when the die is inserted into the holder when the die is inserted into the holder and when the die is gripped by the gripper, a detection unit that detects a load amount that represents the degree of load on the gripper in the first direction, and a judgment unit that judges the holding status of the die by the holder based on the load amount, wherein the control unit moves the gripper in the second direction after the holder has performed an operation to release the die, and the judgment unit judges that the release of the die by the holder is abnormal if the load amount is greater than or equal to a predetermined threshold.

[0007] A die changing method according to one aspect of the present invention is a die changing method in a die changing device that changes dies for a press machine that presses a workpiece using dies held in a holder, and the die changing device is equipped with a gripper that grips the die, and includes: moving the gripper in a second direction that is opposite to a first direction that is the direction when the die is inserted into the holder and when the die is gripped by the gripper; detecting a load amount that represents the degree of load on the gripper in the first direction; and determining the holding status of the die by the holder based on the load amount. A die changing method according to one embodiment of the present invention is a die changing method in a die changing device that changes a die for a press machine that presses a workpiece using a die held in a holder, wherein the die changing device is provided with a gripper that grips the die, and includes the steps of: moving the gripper in a second direction that is opposite to the first direction in which the die was inserted into the holder when the die is inserted into the holder and when the die is gripped by the gripper; detecting a load amount that represents the degree of load on the gripper in the first direction; and determining the holding status of the die by the holder based on the load amount; wherein, in moving the gripper, the gripper is moved in the second direction after the holder has performed the operation of holding the die; and, in determining the holding status of the die by the holder, if the load amount is less than a predetermined threshold, determining that the holder is not holding the die normally. A die changing method according to one embodiment of the present invention is a die changing method in a die changing device that changes dies for a press machine that presses a workpiece using dies held in a holder, and the die changing device is equipped with a gripper that grips the die, and includes the steps of: moving the gripper in a second direction that is opposite to the first direction in which the die was inserted into the holder when the die is inserted into the holder and when the die is gripped by the gripper; detecting a load amount that represents the degree of load on the gripper in the first direction; and determining the holding status of the die by the holder based on the load amount; in moving the gripper, the gripper is moved in the second direction after the holder performs an operation to release the die, and in determining the holding status of the die by the holder, if the load amount is greater than or equal to a predetermined threshold value, determining that the release of the die by the holder is not normal. [Effects of the Invention]

[0008] According to the mold changing device and mold changing method of the present invention, it is possible to recognize in advance whether the mold holding status by the holder is normal, which prevents the mold from being forcibly removed from the holder while it is holding the mold, or from releasing the grip of the mold when the holder is no longer able to hold the mold, thereby preventing damage to the mold or the mold changing device (the gripper of the mold changing device) when the mold is being changed.

[0009] In the mold changing device of the above aspect, the control unit may move the gripper in the second direction after the holder has performed the operation of holding the mold, and the determination unit may determine that the holder is not holding the mold properly if the load amount is less than a predetermined threshold. According to this aspect, it is possible to recognize that the holder is not holding the mold properly and prevent the mold from falling due to the gripper releasing its grip on the mold. Furthermore, the mold changing device of the above aspect may include a notification unit that notifies the holder that the holding status is not normal when it is determined that the holder is not holding the mold properly. According to this aspect, the notification unit immediately notifies the holder that the holder is not holding the mold properly, thereby shortening the time during which the press machine stops pressing. Furthermore, in the mold changing device of the above aspect, the determination unit may determine that the holder is holding the mold properly if the load amount is equal to or greater than a predetermined threshold, and the control unit may move the gripper in the first direction by the same amount as when the holder moved the gripper in the second direction when it is determined that the holder is holding the mold properly. According to this aspect, the gripper is moved in the first direction by the same amount as when the gripper was moved in the second direction while the holder was holding the die normally. This prevents damage to the gripper and the die when the gripper releases the die. In the die exchange device of the above aspect, the control unit may move the gripper in the second direction after the holder has performed the die release operation, and the determination unit may determine that the holder has not properly released the die if the load amount is equal to or greater than a predetermined threshold. This aspect recognizes that the holder has not properly released the die, preventing damage to the die and the gripper due to forcibly removing the die held by the holder. Furthermore, the die exchange device of the above aspect may include a notification unit that, when it is determined that the holder has not properly released the die, notifies the user that the holding condition is abnormal. This aspect immediately notifies the user that the holder is not properly holding the die, thereby reducing the amount of time that the press machine is stopped from performing press processing.Furthermore, in the mold changing device of the above aspect, if the control unit determines that the holder has not released the mold normally, the control unit may move the gripper in the first direction by the same amount as when the gripper was moved in the second direction. According to this aspect, the control unit moves the gripper in the first direction by the same amount as when the gripper was moved in the second direction when the holder had not released the mold. This prevents the mold held in the holder from being forcibly removed, and allows the device to quickly proceed to an operation to improve the holding situation, such as retrying the holder's release operation of the mold. Furthermore, in the mold changing device of the above aspect, the determination unit may determine that the holder has released the mold normally if the load amount is less than a predetermined threshold. According to this aspect, it is possible to recognize that the holder has reliably released the mold, allowing the device to quickly proceed to the next operation. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of a press machine and a die changing device according to an embodiment. FIG. [Figure 2] 3A and 3B are diagrams illustrating the respective parts of the mold exchange device and the upper mold according to the embodiment. [Figure 3] 10A and 10B are diagrams illustrating an example of driving a safety member of an upper die according to the embodiment. [Figure 4] 10A and 10B are diagrams illustrating gripping of an upper mold by a mold exchange device according to an embodiment. [Figure 5] 10A and 10B are diagrams illustrating gripping of an upper mold by a mold exchange device according to an embodiment. [Figure 6] FIG. 2 is a block diagram showing an example of a functional configuration of the mold changing device according to the embodiment. [Figure 7] 10 is a flowchart illustrating an example of the flow of a mold replacement process according to the embodiment. [Figure 8] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 9] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 10] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 11] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 12] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 13] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 14] 10A to 10C are diagrams illustrating an example of an operation transition when checking whether the upper mold according to the embodiment is normally held by the holder. [Figure 15] 10 is a flowchart illustrating an example of the flow of a mold replacement process according to the embodiment. [Figure 16] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 17] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 18] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 19] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 20] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 21] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 22] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 23] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. [Figure 24] 10A and 10B are diagrams illustrating an example of an operation when checking whether the upper die according to the embodiment is normally released from the holder. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. The present invention is not limited to the embodiments described below. In the drawings, the scale may be appropriately changed, such as by partially enlarging, reducing, or emphasizing the drawings, in order to explain the embodiments. Furthermore, in the drawings, directions in the drawings may be explained using an XYZ Cartesian coordinate system. In the XYZ Cartesian coordinate system, the horizontal direction is defined as the X direction and the Y direction, and the vertical direction is defined as the Z direction. In the explanation, the X direction, the Y direction, and the Z direction will be explained assuming that the direction indicated by the arrow in the drawing is the + direction, and the direction opposite to the arrow direction is the - direction.

[0012] FIG. 1 is a diagram showing an example of a press machine and a die changing device according to an embodiment. In one aspect, the press machine 100 is a press brake (bending machine) capable of bending a workpiece W. In this embodiment, a press brake may be used as an example of the press machine 100. Note that the press machine 100 may also be a press machine capable of blanking (punching) or forming the workpiece W. The press machine 100 presses the workpiece W using a die 10 (upper die 13) held by a holder 12.

[0013] The die exchange device 200 exchanges the die 10 (upper die 13) for the press machine 100. The die 10 (upper die 13) used for the exchange is stored in the stocker 4. The stocker 4 has a storage section 43. The storage section 43 has a holding section 43a that holds the die 10 (upper die 13). Note that the holding section 43a is not limited to a configuration that holds the die 10 (upper die 13) in a suspended state, and may be configured to be placed on a table, for example. The die exchange device 200 is a manipulator that includes a gripper 210 (see FIG. 2, etc.) that grips the die 10 (upper die 13) and is movable between the stocker 4 and the press machine 100. The die exchange device 200 according to this embodiment is characterized mainly by the processes when the die 10 (upper die 13) is inserted into the holder 12 and when the die 10 (upper die 13) is removed from the holder 12.

[0014] When the mold 10 (upper mold 13) is inserted into the holder 12 and gripped by the gripper 210, the mold exchange device 200 moves the gripper 210 in a second direction that is opposite to a first direction that is the direction when the mold 10 (upper mold 13) is inserted into the holder 12. In FIG. 1, the first direction is the +Z direction, and the second direction is the -Z direction. The mold exchange device 200 detects a load amount that indicates the degree of load applied to the gripper 210 in the first direction. Based on the detected load amount, the mold exchange device 200 determines the holding status of the mold 10 (upper mold 13) by the holder 12.

[0015] The determination of the holding status is performed to confirm whether the mold 10 (upper mold 13) is normally held (fixed) by the holder 12. That is, after the operation of holding the mold 10 (upper mold 13) by the holder 12 is performed, the mold exchanging device 200 moves the gripper 210 in the second direction, and if the amount of load applied to the gripper 210 in the first direction is less than a predetermined threshold, determines that the mold 10 (upper mold 13) is not normally held by the holder 12.

[0016] The determination of the holding status is also performed to confirm whether the mold 10 (upper mold 13) has been normally released from the holder 12. That is, after the holder 12 has performed an operation to release the mold 10 (upper mold 13), the mold exchanging device 200 moves the gripper 210 in the second direction, and if the amount of load on the gripper 210 in the first direction is equal to or greater than a predetermined threshold, determines that the release of the mold 10 (upper mold 13) by the holder 12 has not been normal. Details of the processing in the mold exchanging device 200 will be described later.

[0017] The press machine 100 includes a processing machine body 2. The front side of the processing machine body 2 is a workspace for an operator. The operator places the workpiece W in a predetermined position from the front side of the processing machine body 2 and sandwiches the workpiece W between an upper mold 13 and a lower mold 6, which serve as dies 10, thereby bending the workpiece W. The processing machine body 2 includes a main body frame 5, a table 7, side covers 8 and 9, a ram 11, a drive unit 14, a display device 33, and an operation unit 34.

[0018] The main body frame 5 forms the outer shell of the press machine 100. The table 7 is attached to the front side (front surface) of the main body frame 5 and fixes the lower die 6. The lower die 6 is a fixed (lower) die supported on the upper surface of the table 7 and is formed long in the left-right direction (X direction). The lower die 6 has, for example, a V-shaped recess (not shown) on the upper surface for bending the workpiece W. The recess is formed long in the left-right direction. Note that while FIG. 1 shows the lower die 6 as an integrated die extending in the left-right direction, this configuration is not limiting. For example, a configuration in which separate dies are arranged side by side in the left-right direction (X direction in FIG. 1) is also possible. The table 7 is also provided with a positioning portion 7a for abutting the workpiece W in the +Y direction to position it. Note that the positioning portion 7a may be provided on the main body frame 5 instead of the table 7.

[0019] The side covers 8 and 9 are provided on the upper left and right sides of the main frame 5. The side covers 8 and 9 are arranged to cover the upper left and right sides of the ram 11. The main frame 5 is provided with a guide portion (not shown) that guides the ram 11 in the up and down direction. The drive unit 14 is supported on the main frame 5 by a support frame (not shown) or the like. The drive unit 14 moves (lifts and lowers) the ram 11 in the Z direction. The drive unit 14 may be a mechanism that lifts and lowers the ram 11 by rotating a ball screw or a nut using an electric motor or the like. Alternatively, the drive unit 14 may be a mechanism that lifts and lowers the ram 11 using a hydraulic cylinder device or a pneumatic cylinder device.

[0020] The ram 11 is supported by a guide portion (not shown) of the main frame 5 so as to be able to move up and down on the main frame 5. For example, a pair of rollers is provided on both the left and right ends of the ram 11, and the pair of rollers is arranged sandwiching a bracket (a guide portion (not shown)) provided on the main frame 5. The ram 11 is, for example, a plate-shaped member made of metal or the like, and has a weight of several tens to several hundred kilograms. The ram 11 is connected to a part of the drive unit 14 and is arranged in a state where it is suspended by the drive unit 14. The ram 11 moves up and down when driven by the drive unit 14, and moves toward or away from the lower mold 6 on the table 7.

[0021] A holder (upper die holder) 12 is attached below the ram 11. The holder 12 is arranged along the left-right direction (X direction) and can hold an upper die 13. For example, when bending a workpiece W, the holder 12 holds an upper die 13 appropriate for each step of the bending process. The upper die 13 is replaced by a die replacement device 200. The holder 12 holds the upper die 13 by driving a clamp member 12a (see FIG. 8, etc.) using a clamp drive unit 50 (see FIG. 8, etc.). In this embodiment, an example is given in which the holder 12 holds the upper die 13 by using a safety member 13f (see FIG. 3, etc.) provided on the upper die 13 in addition to driving the clamp member 12a. The configuration in which the holder 12 holds the upper die 13 will be described later.

[0022] The display device 33 is a display that displays and outputs various information such as the operating status and operating conditions of the processing machine main body 2, and the processing conditions of the workpiece W. The display device 33 is capable of displaying the shape of the workpiece W, etc. The operation unit 34 is equipped with input devices such as a keyboard and a mouse. Note that a touch panel provided on the display device 33 may be used as the operation unit 34. In this case, the operation unit 34 is provided integrally with the display device 33. The touch panel provided on the display device 33 may also be equipped with a keyboard, etc.

[0023] FIG. 2 is a diagram illustrating each component of the mold changing device and the upper mold according to the embodiment. As shown in FIG. 2, the mold changing device 200 includes a gripper 210 including a gripper box 211, a cone 212, a tip 213, an air connection 214, and an air flow path 215. The air connection 214 is disposed at a predetermined position in the gripper box 211 and is connected via a pipe or the like to an air supply unit (not shown) that supplies air Ai. This allows the gripper 210 to supply air Ai supplied from the air supply unit to the air flow path 215 disposed in the cone 212 and the tip 213 via the air connection 214. Note that the air supply unit does not always supply air Ai. The air supply unit does not supply air Ai in the state shown in FIG. 2 (at least when the mold changing device 200 and the upper mold 13 are separated). The timing at which the air supply unit supplies air Ai will be described later.

[0024] The upper die 13 has a through hole 13a, a groove 13b, a base 13c, a cutting edge 13d, an air passage 13e, and a safety member 13f. The through hole 13a allows the tip 213 of the gripper 210 to be inserted. The groove 13b is used to fix the upper die 13 with a clamp member 12a disposed on the holder 12. The base 13c is the portion of the upper die 13 that is held by the holder 12. The cutting edge 13d faces a recess (not shown) in the lower die 6 as the lower end of the upper die 13 when the upper die 13 is held by the holder 12. As a result, in the press machine 100, the upper die 13 moves toward the lower die 6 as the ram 11 moves. Until the upper die 13 reaches, for example, its lowest point, the workpiece W is sandwiched between the upper die 13 and the lower die 6, thereby bending the workpiece W. The bending angle of the workpiece W can be changed by the amount of descent of the upper die 13. The air flow path 13e is a flow path for air Ai within the upper die 13. The safety member 13f is used to hold the upper die 13 by the holder 12. When the safety member 13f is not receiving a supply of air Ai, it is biased by a biasing means (for example, a biasing spring, etc.) and is in a state where it protrudes from the upper die 13. The safety member 13f in a state where it protrudes from the upper die 13 is used to hold the upper die 13 by the holder 12.

[0025] 3 is a diagram showing an example of driving the safety member of the upper mold according to the embodiment. As shown in FIG. 3, the mold exchange device 200 moves from the state shown in FIG. 2 toward the upper mold 13 (for example, the +Y direction in FIG. 3) and inserts the tip portion 213 into the through-hole 13a of the upper mold 13. Here, the mold exchange device 200 inserts the tip portion 213 into the through-hole 13a of the upper mold 13 to a position where air Ai can flow through both the air flow path 215 and the air flow path 13e. Then, the mold exchange device 200 supplies air Ai from the air supply unit to the air flow path 215 and the air flow path 13e via the air connection unit 214. The air Ai is mainly supplied when the upper mold 13 is held by the holder 12 or when the upper mold 13 is released from the holder 12. As a result, the safety member 13f is driven by the supply of air Ai, which relieves the biasing force of the biasing means, and is drawn into the interior of the upper mold 13.

[0026] 4 and 5 are diagrams illustrating gripping of the upper mold by the mold exchanging device according to the embodiment. As shown in FIG. 4, the mold exchanging device 200 further includes a ball 216 and a ball driving unit 217. Two or more balls 216 are arranged at predetermined positions of the tip portion 213 to be inserted into the through hole 13a. The ball driving unit 217 drives the ball 216 to protrude from the tip portion 213 or to sink (retract) into the tip portion 213. The ball driving unit 217 sinks the ball 216 into the tip portion 213 at least when the tip portion 213 is not inserted into the through hole 13a. The upper mold 13 further includes a ball groove 13g inside (a part of the through hole 13a) that is large enough to fit the ball 216 therein.

[0027] As shown in FIG. 5, the mold exchange device 200 moves from the state shown in FIG. 4 toward the upper mold 13 (for example, the +Y direction in FIG. 5) and inserts the tip portion 213 into the through hole 13a of the upper mold 13. Here, the mold exchange device 200 inserts the tip portion 213 into the through hole 13a of the upper mold 13 to a position where the protruding ball 216 can fit into the ball groove 13g when the ball 216 is protruded. Then, the mold exchange device 200 drives the ball 216 using the ball drive unit 217 to protrude from the tip portion 213, thereby fitting the ball 216 into the ball groove 13g. In this way, the mold exchange device 200 realizes gripping of the upper mold 13 by the gripper 210. Note that the ball groove 13g may not be provided, and gripping of the upper mold 13 by the gripper 210 may be realized by pressing the protruding ball 216 against the inner wall of the through hole 13a. As a result, the mold exchanging device 200 can carry out transportation while holding the upper mold 13.

[0028] 6 is a block diagram showing an example of the functional configuration of a mold exchange device according to an embodiment. As shown in FIG. 6, the mold exchange device 200 includes a control unit 220, a detection unit 230, a determination unit 240, and a notification unit 250. The control unit 220 comprehensively controls the operation of the mold exchange device 200 and controls the movement of the mold exchange device 200 and the operation of the gripper 210 (for example, operation based on a motor, etc.). When the upper mold 13 is inserted into the holder 12 and when the upper mold 13 is gripped by the gripper 210, the control unit 220 moves the gripper 210 in a second direction that is the opposite direction to the first direction that is the direction when the upper mold 13 is inserted into the holder 12.

[0029] Here, the state in which the upper die 13 is inserted into the holder 12 and the state in which the upper die 13 is gripped by the gripper 210 refers to a state after the operation of inserting the upper die 13 into the holder 12 and holding the upper die 13 by the holder 12 has been performed. In other words, this is a case in which it is confirmed whether the upper die 13 is properly held by the holder 12. Alternatively, the state in which the upper die 13 is inserted into the holder 12 and the state in which the upper die 13 is gripped by the gripper 210 refers to a state after the operation of inserting the tip portion 213 of the gripper 210 into the through-hole 13a and releasing the upper die 13 by the holder 12 has been performed. In other words, this is a case in which it is confirmed whether the upper die 13 is properly released from the holder 12. In this state, the control unit 220 moves the gripper 210 in a second direction that is opposite to the first direction that is the direction when the upper die 13 is inserted into the holder 12. The movement of the gripper 210 in the second direction is an amount that does not damage the gripper 210 gripping the upper die 13, assuming that the upper die 13 is fixed to the holder 12. In FIG. 1, the first direction is the +Z direction, and the second direction is the -Z direction.

[0030] The detection unit 230 detects the amount of load that indicates the degree of load in the first direction that is applied to the gripper 210. Specifically, when the control unit 220 moves the gripper 210 in the second direction, the detection unit 230 detects the amount of load in the first direction that is applied to the gripper 210 from the electric energy of a motor or the like that operates the gripper 210. For example, the detection unit 230 stores in advance the electric energy of a motor or the like when the gripper 210 grips the upper mold 13 that is not held by the holder 12 and moves in the second direction, and detects the amount of load from the difference between this amount and the electric energy of the motor or the like.

[0031] The determination unit 240 determines the holding status of the upper mold 13 by the holder 12 based on the load amount. As described above, the determination of the holding status is performed to confirm whether the upper mold 13 is held properly by the holder 12. Alternatively, the determination of the holding status is performed to confirm whether the upper mold 13 is released properly from the holder 12. First, a case of confirming whether the upper mold 13 is held properly by the holder 12 will be described. Specifically, if the load amount detected by the detection unit 230 is less than a predetermined threshold, the determination unit 240 determines that the upper mold 13 is not being held properly by the holder 12. That is, if the upper mold 13 is held properly by the holder 12, a load of a certain level or more is applied, so the determination unit 240 determines that the upper mold 13 is not being held properly by the holder 12 if the load amount is less than the predetermined threshold. On the other hand, if the load amount detected by the detection unit 230 is equal to or greater than the predetermined threshold, the determination unit 240 determines that the upper mold 13 is being held properly by the holder 12. Here, when the determination unit 240 determines that the holder 12 is holding the upper mold 13 normally, the control unit 220 moves the gripper 210 in the first direction by the amount of movement when the gripper 210 was moved in the second direction. That is, the control unit 220 moves the gripper 210 in the second direction to determine the holding status, and if the holder 12 is holding the upper mold 13 normally, the control unit 220 moves the gripper 210 in the first direction by the amount of movement when the gripper 210 was moved in the second direction, thereby returning the upper mold 13 to its original position (the position before movement). Then, the control unit 220 controls to remove the gripper 210 from the through-hole 13a.

[0032] Next, a case will be described in which it is confirmed whether the upper mold 13 has been normally released from the holder 12. Specifically, when the load amount detected by the detection unit 230 is equal to or greater than a predetermined threshold, the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal. That is, if the upper mold 13 has been normally released from the holder 12, a load of a certain level or more is not applied, and therefore, when the load amount is equal to or greater than the predetermined threshold, the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal. Here, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal, the control unit 220 moves the gripper 210 in the first direction by the same amount as when the gripper 210 was moved in the second direction. That is, the control unit 220 moves the gripper 210 in the second direction to determine the holding state, and if the release of the upper mold 13 by the holder 12 is not normal, the control unit 220 moves the gripper 210 in the first direction by the same amount as when the gripper 210 was moved in the second direction, thereby returning the upper mold 13 to its original position (the position before the movement). On the other hand, the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal. When the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal, the control unit 220 controls the mold exchange device 200 to continue conveying the upper mold 13.

[0033] When it is determined that the holder 12 is not holding the upper mold 13 normally, the notification unit 250 notifies that the holding situation is not normal. Specifically, when the determination unit 240 determines that the holder 12 is not holding the upper mold 13 normally in determining whether the holder 12 is holding the upper mold 13 normally, the notification unit 250 transmits information including the fact that the holding situation is not normal to a predetermined device. Note that the notification by the notification unit 250 only needs to notify a user such as an operator or a manager, and may, for example, output a sound or a light. When the holding situation is not normal, the control unit 220 may stop the operation of the mold exchange device 200 or may retry control to have the holder 12 hold the upper mold 13.

[0034] Furthermore, when it is determined that the release of the upper mold 13 by the holder 12 is not normal, the notification unit 250 notifies that the holding condition is not normal. Specifically, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal in determining the holding condition to confirm whether the upper mold 13 has been released normally from the holder 12, the notification unit 250 transmits information including the fact that the holding condition is not normal to a predetermined device. Note that the notification by the notification unit 250 may be any notification to a user such as an operator or a manager, and may be, for example, an output of sound or light. When the holding condition is not normal, the control unit 220 may stop the operation of the mold exchange device 200 or may retry control to release the upper mold 13 from the holder 12 (driving the clamp member 12a and driving the safety member 13f).

[0035] Fig. 7 is a flowchart showing an example of the flow of the mold replacement process according to the embodiment. Fig. 7 explains the flow of the mold replacement process when checking whether the upper mold 13 is properly held by the holder 12. In the following explanation of Fig. 7, Figs. 8 to 14 are also used as appropriate. Figs. 8 to 14 are diagrams showing an example of the operation transition when checking whether the upper mold according to the embodiment is properly held by the holder. In Figs. 8 to 14, two or more balls 216 are represented by a single oval, and a state in which they are protruding from the tip 213 is represented by a texture, and a state in which they are buried in the tip 213 is represented by no texture.

[0036] As shown in FIG. 8 , the holder 12 has a clamp member 12a that holds (fixes) the upper mold 13 and a groove 12b into which a safety member 13f of the upper mold 13 fits. The mold exchange device 200, under the control of the control unit 220, inserts the tip 213 of the gripper 210 into the through-hole 13a, and, under the control of the ball drive unit 217, causes the ball 216 to protrude from the tip 213, thereby gripping the upper mold 13. Then, under the control of the control unit 220, the mold exchange device 200 supplies air Ai from the air supply unit via the air connection unit 214 to the air flow path 215 and the air flow path 13e, thereby drawing the safety member 13f into the interior of the upper mold 13 and inserting the upper mold 13 into the holder 12. A first direction, which is the direction when the upper mold 13 is inserted into the holder 12, is defined as the +Z direction. The mold exchange device 200 can control whether a portion of the gripper 210 including the cone 212 and the tip 213 is fixed or not fixed relative to the gripper box 211. When the portion is not fixed, the portion can hang down in a circumferential direction about the direction in which the tip 213 is inserted into the through-hole 13a (the Y direction in FIG. 8). When the mold exchange device 200 inserts the gripped upper mold 13 into the holder 12, the mold exchange device 200 fixes the portion of the gripper 210 including the cone 212 and the tip 213 (hereinafter, sometimes referred to as a tip lock state). Next, as shown in FIG. 9, the mold exchange device 200 stops the supply of air Ai from the air supply unit under the control of the control unit 220, causes the safety member 13f to protrude from the upper mold 13, and inserts the safety member 13f into the groove 12b.

[0037] 8 and 9, the control unit 220 moves the gripper 210 in the second direction as shown in FIG. 7 (step S101). Specifically, the control unit 220 moves the gripper 210 in the second direction (e.g., −Z direction) that is the opposite direction to the first direction (e.g., +Z direction) that is the direction when the upper mold 13 is inserted into the holder 12 after the state shown in FIG. 8 and 9 (see FIG. 10). At this time, the detection unit 230 detects the amount of load applied to the gripper 210 in the first direction (step S102). Specifically, when the gripper 210 is moved in the second direction by the control unit 220, the detection unit 230 detects the amount of load applied to the gripper 210 in the first direction from the electric energy of a motor or the like that operates the gripper 210.

[0038] The determination unit 240 determines the holding status of the upper mold 13 by the holder 12 based on whether the load amount is less than a predetermined threshold (step S103). Specifically, when the load amount detected by the detection unit 230 is less than the predetermined threshold, the determination unit 240 determines that the holder 12 is not holding the upper mold 13 normally (step S103: YES). When the determination unit 240 determines that the holder 12 is not holding the upper mold 13 normally, the control unit 220 and the notification unit 250 execute an operation in the event of an abnormality (step S104). Specifically, when the determination unit 240 determines that the holder 12 is not holding the upper mold 13 normally, the notification unit 250 transmits information including the fact that the holding status is not normal to a predetermined device. Furthermore, when the determination unit 240 determines that the holder 12 is not holding the upper mold 13 normally, the control unit 220 stops the operation of the mold exchange device 200. Furthermore, when the determining unit 240 determines that the holder 12 is not holding the upper die 13 normally, the control unit 220 may try again to control the holder 12 to hold the upper die 13 .

[0039] On the other hand, when the load amount detected by the detection unit 230 is equal to or greater than the predetermined threshold, the determination unit 240 determines that the holder 12 is holding the upper mold 13 normally (step S103: NO). When the determination unit 240 determines that the holder 12 is holding the upper mold 13 normally, the control unit 220 executes a normal operation (step S105). Specifically, when the determination unit 240 determines that the holder 12 is holding the upper mold 13 normally, the control unit 220 performs control to move the gripper 210 in the first direction by the same amount as when the gripper 210 was moved in the second direction, and return the upper mold 13 to its original position (the position before movement).

[0040] When it is determined that the holder 12 is holding the upper mold 13 normally, the mold exchange device 200 releases the tip lock state as shown in FIG. 11. In FIG. 11, the state in which the tip lock state is released is represented by a bidirectional block arrow. Then, as shown in FIG. 12, the mold exchange device 200 sinks the ball 216 into the tip portion 213 under the control of the ball drive unit 217. Next, as shown in FIG. 13, the mold exchange device 200 removes the tip portion 213 of the gripper 210 from the through hole 13a under the control of the control unit 220. Furthermore, the mold exchange device 200 repeatedly performs the above process for the upper mold 13 (the next upper mold 13, and each of the multiple upper molds 13) to be held by the holder 12. 14, the clamp driving unit 50 drives the clamp member 12a to insert the clamp member 12a into the groove 13b (if there are multiple upper dies 13, into all of the grooves 13b of the multiple upper dies 13). This achieves the fixation of the upper die 13 by the holder 12. Note that the operation of driving the clamp member 12a to insert it into the groove 13b may be performed at the same time as inserting the safety member 13f into the groove 12b when only one upper die 13 is to be held by the holder 12 or when the last upper die 13 of the multiple upper dies 13 is to be held by the holder 12.

[0041] Fig. 15 is a flowchart showing an example of the flow of the mold replacement process according to the embodiment. Fig. 15 explains the flow of the mold replacement process when checking whether the upper mold 13 has been properly released from the holder 12. In the following explanation of Fig. 15, Figs. 16 to 24 will also be used as appropriate. Figs. 16 to 24 are diagrams showing an example of the operation when checking whether the upper mold according to the embodiment has been properly released from the holder. In Figs. 16 to 24, two or more balls 216 are indicated by a single oval, and a state in which they are protruding from the tip 213 is indicated by texture, and a state in which they are sunk into the tip 213 is indicated by no texture.

[0042] As shown in FIG. 16, the holder 12 has a clamp member 12a that holds (fixes) the upper mold 13 and a groove 12b into which a safety member 13f of the upper mold 13 fits. Also, in FIG. 16, the clamp member 12a is driven by the clamp driving unit 50, and the clamp member 12a is inserted into the groove 13b, and the safety member 13f is inserted into the groove 12b, thereby holding (fixing) the upper mold 13. Additionally, the mold exchanging device 200 is in a state in which the ball 216 is embedded in the tip portion 213 and in a tip-locked state. Then, as shown in FIGS. 17 and 18, the mold exchanging device 200 releases the tip-locked state and moves in a direction (e.g., the +Y direction) for inserting the tip portion 213 into the through-hole 13a, thereby inserting the tip portion 213 into the through-hole 13a. Next, as shown in FIG. 19, the mold exchanging device 200 causes the ball 216 to protrude from the tip end portion 213 under the control of the ball driving unit 217, thereby gripping the upper mold 13.

[0043] 20, under the control of the control unit 220, the mold exchanging device 200 supplies air Ai from the air supply unit to the air flow path 215 and the air flow path 13e via the air connection unit 214, thereby retracting the safety member 13f into the interior of the upper mold 13. Then, as shown in FIGS. 21 and 22, the mold exchanging device 200 is set to a tip-lock state, and the clamp driving unit 50 drives the clamp member 12a to release the clamp member 12a from the groove portion 13b.

[0044] 16 to 22, the control unit 220 moves the gripper 210 in the second direction as shown in FIG. 15 (step S201). Specifically, the control unit 220 moves the gripper 210 in the second direction (e.g., −Z direction) that is the opposite direction to the first direction (e.g., +Z direction) that is the direction when the upper mold 13 is inserted into the holder 12 after the state shown in FIGS. 16 to 22 (see FIG. 23). At this time, the detection unit 230 detects the amount of load applied to the gripper 210 in the first direction (step S202). Specifically, when the gripper 210 is moved in the second direction by the control unit 220, the detection unit 230 detects the amount of load applied to the gripper 210 in the first direction from the electric energy of a motor or the like that operates the gripper 210.

[0045] The determination unit 240 determines the holding status of the upper mold 13 by the holder 12 based on whether the load amount is equal to or greater than a predetermined threshold (step S203). Specifically, when the load amount detected by the detection unit 230 is equal to or greater than a predetermined threshold, the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is abnormal (step S203: YES). When the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is abnormal, the control unit 220 and the notification unit 250 perform an operation in the event of an abnormality (step S204). Specifically, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is abnormal, the notification unit 250 transmits information including the fact that the holding status is abnormal to a predetermined device. Furthermore, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal, the control unit 220 performs control to move the gripper 210 in the first direction by the same amount as when the gripper 210 was moved in the second direction, and return the upper mold 13 to its original position (the position before the movement). Furthermore, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is not normal, the control unit 220 may again attempt control to retract the clamp member 12a into the holder 12 by the clamp drive unit 50 or retract the safety member 13f into the upper mold 13 by supplying air Ai.

[0046] On the other hand, when the load amount detected by the detection unit 230 is less than the predetermined threshold, the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal (step S203: NO). When the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal, the control unit 220 executes a normal operation (step S205). Specifically, when the determination unit 240 determines that the release of the upper mold 13 by the holder 12 is normal, the control unit 220 performs control to continue the conveyance of the upper mold 13 by the mold exchange device 200. For example, as shown in FIG. 24 , under the control of the control unit 220, the mold exchange device 200 further moves the held upper mold 13 in the second direction (e.g., the −Z direction) to completely remove the upper mold 13 from the holder 12 and convey the upper mold 13 to the stocker 4 or the like.

[0047] As described above, according to the mold exchanging device 200 of the embodiment, after the operation of holding the upper die 13 by the holder 12 is performed, the holding status of the upper die 13 by the holder 12 is determined based on the amount of load applied to the gripper 210 when the gripper 210 is moved in the second direction, thereby preventing the gripper 210 from releasing the upper die 13 even when the upper die 13 is not being held by the holder 12 and preventing damage to the upper die 13 due to dropping the upper die 13. Furthermore, according to the mold exchanging device 200 of the embodiment, after the operation of releasing the upper die 13 by the holder 12 is performed, the holding status of the upper die 13 by the holder 12 is determined based on the amount of load applied to the gripper 210 when the gripper 210 is moved in the second direction, thereby preventing damage to the upper die 13 and the gripper 210 due to forcibly removing the upper die 13 from the holder 12 that is holding the upper die 13. Furthermore, according to the die changing device 200 of the embodiment, an abnormal holding state of the upper die 13 by the holder 12 is notified, thereby shortening the time during which the press working by the press machine 100 is stopped. Furthermore, according to the die changing device 200 of the embodiment, when the holding state of the upper die 13 by the holder 12 is normal, the gripper 210 is moved in the first direction by the amount of movement of the gripper 210 in the second direction performed to confirm that the holding of the upper die 13 by the holder 12 is normal, thereby preventing damage to the gripper 210 and the upper die 13 when the grip of the upper die 13 by the gripper 210 is released. Furthermore, according to the mold exchange device 200 of the embodiment, when the release of the upper mold 13 by the holder 12 is not normal, the gripper 210 is moved in the first direction by the same amount as the movement of the gripper 210 in the second direction performed to confirm that the release of the upper mold 13 by the holder 12 is normal. This prevents the upper mold 13 held by the holder 12 from being forcibly removed, and allows for quick transition to an operation to improve the holding situation, such as retrying the release operation of the upper mold 13 by the holder 12.Furthermore, according to the mold exchange device 200 of the embodiment, in order to confirm the release of the upper mold 13 by the holder 12, if the load amount on the gripper 210 is less than a predetermined threshold, it is determined that the release of the upper mold 13 by the holder 12 is normal, so it is possible to recognize that the release of the upper mold 13 by the holder 12 is being carried out reliably, and to quickly move on to the next operation.

[0048] Although the embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above-described embodiments. Furthermore, forms incorporating such modifications or improvements are also included within the technical scope of the present invention. One or more of the requirements described in the above-described embodiments may be omitted. Furthermore, the requirements described in the above-described embodiments may be combined as appropriate. Furthermore, to the extent permitted by law, the disclosures of all documents cited in the above-described embodiments are incorporated by reference into this description.

[0049] In the above-described embodiment, the die exchange device 200 has been described, which prevents damage to the upper die 13 and the gripper 210 when the upper die 13 is exchanged. However, this embodiment is not limited thereto and can be similarly applied to the exchange of the lower die 6 (see FIG. 1 ). The die exchange device 200 exchanges the lower die 6 fixed to the table 7 of the press machine 100 (e.g., a lower die support member serving as a holder provided on the table 7 side). The lower die 6 used for the exchange may be stored in the stocker 4. The lower die 6 has a different shape from the upper die 13, such as having a recess for clamping the workpiece W between the upper die 13 and the lower die 6. However, like the upper die 13, the lower die 6 has a through-hole into which the tip 213 of the gripper 210 can be inserted and a groove for fixing the lower die 6 by driving a clamp member provided on the lower die support member on the table 7 side. Furthermore, the lower die 6 does not necessarily have a member corresponding to the safety member 13f provided on the upper die 13. The mold exchanging device 200 grasps and transports the lower mold 6 in the same manner as the above-described grasping of the upper mold 13.

[0050] The mold exchanging device 200, in a state where the lower mold 6 is inserted into the lower mold support member on the table 7 side and the gripper 210 is gripping the lower mold 6, moves the gripper 210 in a second direction, which is a direction opposite to a first direction, which is a direction when the lower mold 6 is inserted into the lower mold support member on the table 7 side. Here, the state where the lower mold 6 is inserted into the lower mold support member on the table 7 side and the state where the lower mold 6 is gripped by the gripper 210 refers to a state after an operation of inserting the lower mold 6 into the lower mold support member on the table 7 side and holding the lower mold 6 by the lower mold support member is performed. In other words, this is a case where it is confirmed whether the lower mold 6 is properly held (fixed) by the lower mold support member. Alternatively, the state where the lower mold 6 is inserted into the lower mold support member on the table 7 side and the state where the lower mold 6 is gripped by the gripper 210 refers to a state after an operation of inserting the tip 213 of the gripper 210 into the through-hole of the lower mold 6 and releasing the lower mold 6 by the lower mold support member is performed. That is, this is the case where it is necessary to check whether the lower mold 6 has been released normally from the lower mold support member. In this state, the mold exchanging device 200 (controller 220) moves the gripper 210 in a second direction, which is the opposite direction to the first direction, which is the direction when the lower mold 6 is inserted into the lower mold support member on the table 7 side. In FIG. 1, the first direction is the -Z direction, and the second direction is the +Z direction.

[0051] Thereafter, the mold exchange device 200 detects the amount of load applied to the gripper 210 in the first direction (here, the -Z direction) using the detection unit 230, and determines the holding status of the lower mold 6 by the lower mold support member using the determination unit 240. For example, when checking whether the lower mold 6 is properly held by the lower mold support member, the mold exchange device 200 determines that the lower mold 6 is not being held properly by the lower mold support member if the amount of load detected by the detection unit 230 is less than a predetermined threshold. Furthermore, when checking whether the lower mold 6 is properly released from the lower mold support member, the mold exchange device 200 determines that the release of the lower mold 6 by the lower mold support member is not properly if the amount of load detected by the detection unit 230 is equal to or greater than a predetermined threshold. In addition to these, the processes performed by the mold exchange device 200 (the control unit 220, the detection unit 230, the determination unit 240, and the notification unit 250) are the same as the processes performed when replacing the upper mold 13.

[0052] As described above, according to the mold exchanging device 200 of the embodiment, after the operation of holding the lower die 6 by the lower die support member is performed, the holding status of the lower die 6 by the lower die support member is determined based on the amount of load in the first direction (here, the −Z direction) on the gripper 210 when the gripper 210 is moved in the second direction (here, the +Z direction). This prevents the gripper 210 from releasing the lower die 6 even when the lower die 6 is not being held by the lower die support member, thereby preventing damage to the lower die 6 caused by processing by the press machine 100 being performed in a situation where the lower die 6 is not being held by the lower die support member. Similarly, according to the mold exchanging device 200, after the operation of releasing the lower die 6 by the lower die support member is performed, the holding status of the lower die 6 by the lower die support member is determined based on the amount of load in the first direction (here, the −Z direction) on the gripper 210 when the gripper 210 is moved in the second direction (here, the +Z direction). This prevents damage to the lower die 6 and the gripper 210 caused by forcibly removing the lower die 6 from the lower die support member that is holding the lower die 6. [Explanation of symbols]

[0053] 2...Processing machine body 4. Stocker 5. Main frame 6...Lower mold 7. Table 7a Positioning part 8,9 Side cover 10. Mold 11. Ram 12 Holder 12a Clamping member 12b...Groove 13...upper mold 13a...Through hole 13b...Groove 13c...Base 13d Cutting edge 13e Air flow path 13f Safety parts 13g Ball groove 14. Drive unit 33...Display device 34...Operation unit 43...Storage Department 43a...Holding part 50 Clamp drive unit 100···Press machine 200···Mold change device 210 Gripper 211 Gripper box 212... Cone 213...Tip 214···Air connection 215 Air flow path 216···Ball 217 Ball drive unit 220 Control unit 230...Detection unit 240...Judgment section 250···Information Department Ai...Air W...Work

Claims

1. A die changing device for changing dies for a press machine that presses a workpiece using dies held by a holder, a gripper that grips the mold; a control unit that moves the gripper in a second direction that is opposite to a first direction that is the direction when the mold is inserted into the holder, when the mold is inserted into the holder and when the mold is gripped by the gripper; a detection unit that detects a load amount that indicates the degree of the load applied to the gripper in the first direction; a determination unit that determines a holding state of the mold by the holder based on the load amount; Equipped with the control unit moves the gripper in the second direction after the holder has performed an operation of holding the mold, The determination unit determines that the holder is not holding the die normally when the load amount is less than a predetermined threshold.

2. The mold changing device according to claim 1 , further comprising an alarm unit that, when it is determined that the mold is not being held normally by the holder, notifies the user that the holding state is not normal.

3. the determination unit determines that the mold is normally held by the holder when the load amount is equal to or greater than the predetermined threshold value; 3. The mold exchange device according to claim 1, wherein the control unit, when it is determined that the mold is being held normally by the holder, moves the gripper in the first direction by the same amount as when the gripper was moved in the second direction.

4. the control unit moves the gripper in the second direction after the holder has performed an operation of releasing the mold, The mold changing device according to claim 1 , wherein the determining unit determines that the release of the mold by the holder is abnormal when the load amount is equal to or greater than a predetermined threshold value.

5. The mold changing device according to claim 4 , further comprising a notification unit that notifies the user that the holding state is not normal when it is determined that the release of the mold by the holder is not normal.

6. 6. The mold exchange device according to claim 4, wherein the control unit, when it is determined that the release of the mold by the holder is not normal, moves the gripper in the first direction by the same amount as when the gripper was moved in the second direction.

7. The mold changing device according to claim 4 , wherein the determining unit determines that the release of the mold by the holder is normal when the load amount is less than the predetermined threshold value.

8. A die changing device for changing dies for a press machine that presses a workpiece with a die held in a holder, comprising: a gripper that grips the mold; a control unit that moves the gripper in a second direction that is opposite to a first direction that is the direction when the mold is inserted into the holder, when the mold is inserted into the holder and when the mold is gripped by the gripper; a detection unit that detects a load amount that indicates the degree of the load applied to the gripper in the first direction; a determination unit that determines a holding state of the mold by the holder based on the load amount; Equipped with the control unit moves the gripper in the second direction after the holder has performed an operation of releasing the mold, The determination unit determines that the release of the die by the holder is abnormal when the load amount is equal to or greater than a predetermined threshold.

9. A mold exchange device as described in Claim 8, which is provided with an alarm unit that alerts that the holding status is not normal when it is determined that the release of the mold by the holder is not normal.

10. A mold exchange device as described in claim 8 or claim 9, wherein the control unit, when it determines that the release of the mold by the holder is not normal, moves the gripper in the first direction by the same amount as when the gripper was moved in the second direction.

11. A mold exchange device as described in any one of claims 8 to 10, wherein the judgment unit judges that the release of the mold by the holder is normal when the load amount is less than the predetermined threshold value.

12. 1. A die changing method in a die changing device for changing a die for a press machine that presses a workpiece using a die held by a holder, comprising: the mold changing device includes a gripper that grips the mold, In a state where the mold is inserted into the holder and in a state where the mold is gripped by the gripper, moving the gripper in a second direction that is a direction opposite to a first direction that is a direction when the mold is inserted into the holder; detecting a load amount representing a degree of load applied to the gripper in the first direction; determining a holding state of the mold by the holder based on the load amount; Including, In the movement of the gripper, after the operation of holding the mold by the holder is performed, the gripper is moved in the second direction; In the determination of the holding status of the mold by the holder, if the load amount is less than a predetermined threshold, it is determined that the mold is not being held normally by the holder.

13. A die changing method in a die changing device for changing a die for a press machine that presses a workpiece with a die held in a holder, comprising: the mold changing device includes a gripper that grips the mold, In a state where the mold is inserted into the holder and in a state where the mold is gripped by the gripper, moving the gripper in a second direction that is a direction opposite to a first direction that is a direction when the mold is inserted into the holder; detecting a load amount representing a degree of load applied to the gripper in the first direction; determining a holding state of the mold by the holder based on the load amount; Including, In the movement of the gripper, after the holder performs an operation of releasing the die, the gripper is moved in the second direction; In the determination of the holding state of the die by the holder, if the load amount is equal to or greater than a predetermined threshold, it is determined that the release of the die by the holder is not normal.

Images