Mold changing device

Abstract

To achieve both of stability of a conveyance operation of a mold stocker and reduction of a change time of a mold.SOLUTION: A mold change device 5 comprises: a lower mold station 80 which takes out a lower mold stocker 65 being a target from the plurality of lower mold stockers 65 and conveys the lower mold stocker 65 to a lower mold change position set on the lateral side of a lower mold holder 18; and a control device 100 which controls the operation of the lower mold station 80. The lower mold station 80 comprises: a stocker support part 85; an air cylinder 86 which moves up and down the stocker support part 85; an air adjustment unit 87 which adjusts an amount of the air exhausted from the air cylinder 86; and a sensor part 865 which detects a stroke position of an operation rod 861 of the air cylinder 86. The control device 100 controls the air adjustment unit 87 on the basis of the stroke position, and controls the moving-up / down speed of the stocker support part 85.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a mold changing device.

Background Art

[0002] There is a known technique for automatically changing a mold between a bending machine such as a press brake and a mold storage device installed on the side of the bending machine using a mold changing device. For example, Patent Document 1 discloses a mold station that conveys a mold stocker that stores a mold such as a die in a mold storage device to a mold changing position set on the side of a mold holder of a press brake.

[0003] The mold station includes a stocker support portion that supports the mold stocker and a drive mechanism that moves the stocker support portion in the vertical and front-rear directions. By moving the stocker support portion, the mold stocker can be taken out or the taken-out mold stocker can be conveyed to the mold changing position. For example, an air cylinder is used for the vertical movement of the stocker support portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Normally, the operating rod of an air cylinder moves at a constant speed over the entire stroke length. When the moving speed of the operating rod is too fast, the impact when transferring the mold stocker becomes large, generating a large noise, or causing a displacement or dropping of the mold held by the mold stocker. On the other hand, when the operating speed of the operating rod is slowed down, the time required for mold changing becomes long.

Means for Solving the Problems

[0006] One aspect of the present invention relates to a mold exchange device that exchanges a mold between a mold storage device provided with a plurality of mold stockers for holding molds and a mold holder for mounting molds on a table of a bending machine, comprising: a mold station that takes out a target mold stocker from a plurality of mold stockers arranged in the rearward direction and transports the mold stocker to a mold exchange position set to the side of the mold holder; and a control device that controls the operation of the mold station, wherein the mold station has a stocker support part that supports the mold stocker from below, an air cylinder that moves an operating rod connected to the stocker support part in the vertical direction to raise and lower the stocker support part, an air adjustment unit that adjusts the amount of air exhausted from the air cylinder and the amount of air supplied to the air cylinder, and a sensor part that detects the stroke position of the operating rod, and the control device controls the air adjustment unit based on the stroke position to control the raising and lowering speed of the stocker support part.

[0007] According to one aspect of the present invention, the lifting speed can be switched according to the position of the stocker support. Low-speed lifting suppresses the impact on the mold stocker and also suppresses displacement or dropping of the mold held by the mold stocker. This provides the advantage of stable transport operation of the mold stocker. On the other hand, high-speed lifting allows the mold stocker to be transported quickly, thus providing the advantage of shortening the mold changeover time. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to achieve both stable transport operation of the mold stocker and reduced mold changeover time. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic front view showing the configuration of a bending system including a die changing device according to this embodiment. [Figure 2] Figure 2 is a perspective view showing the main parts of the mold housing device. [Figure 3] Figure 3 is a side view showing the main parts of the mold housing device. [Figure 4] Figure 4 is a front view showing the lower mold station. [Figure 5] Figure 5 is an explanatory diagram showing the configuration of the air adjustment unit. [Figure 6A] Figure 6A is an explanatory diagram showing the operation of the air adjustment unit during high-speed ascent. [Figure 6B] Figure 6B is an explanatory diagram showing the operation of the air adjustment unit during low-speed ascent. [Figure 6C] Figure 6C is an explanatory diagram showing the operation of the air adjustment unit during high-speed descent. [Figure 6D] Figure 6D is an explanatory diagram showing the operation of the air adjustment unit during low-speed descent. [Figure 7] Figure 7 is an explanatory diagram illustrating the operational concept of the lower mold station. [Modes for carrying out the invention]

[0010] The mold changing device according to this embodiment will be described below with reference to the drawings.

[0011] Figure 1 is a schematic front view showing the configuration of a bending system including a die changing device 5 according to this embodiment. In the following description, the directions will be defined as left-right direction, front-back direction, and up-down direction. The left-right direction and front-back direction correspond to two orthogonal directions in the horizontal direction, and the up-down direction corresponds to the vertical direction. In Figure 1, the front side of the paper corresponds to the front direction, and the back side of the paper corresponds to the rear direction. However, these directions are used only for convenience in explaining the configuration of the bending machine.

[0012] The die changing device 5 is a die changing device 5 that exchanges the lower die 2 between a die storage device 6 which is provided with a plurality of lower die stockers 65 that hold the lower die 2 and a lower die holder 18 for mounting the lower die 2 on the lower table 12 of the bending machine 1. The device 5 includes a lower die station 80 which takes out the target lower die stocker 65 from among a plurality of lower die stockers 65 arranged in the front-rear direction and transports the lower die stocker 65 to a lower die changing position set to the side of the lower die holder 18, and a control device 100 which controls the operation of the lower die station 80. The lower mold station 80 includes a stocker support section 85 that supports the lower mold stocker 65 from below, an air cylinder 86 that moves an operating rod 861 connected to the stocker support section 85 vertically to raise and lower the stocker support section 85, an air adjustment unit 87 that adjusts the amount of air exhausted from the air cylinder 86 and the amount of air supplied to the air cylinder 86, and a sensor section 865 that detects the stroke position of the operating rod 861. The control device 100 controls the air adjustment unit 87 based on the stroke position to control the raising and lowering speed of the stocker support section 85.

[0013] Next, the details of the bending system will be described. The bending system comprises a bending machine 1, a die changing device 5, and a die storage device 6.

[0014] The bending machine 1 is, for example, a press brake, and is a machine that performs bending on a sheet metal workpiece W through the cooperation of a lower die 2 and an upper die 4.

[0015] The bending machine 1 comprises a pair of side plates 10, a lower table 12, an upper table 14, and a table drive mechanism 16.

[0016] A pair of side plates 10 are arranged at a distance in the left - right direction. At the lower part of the pair of side plates 10, a lower table 12 extending in the left - right direction is provided, and at the upper part of the pair of side plates 10, an upper table 14 extending in the left - right direction is provided. The upper table 14 is configured to be movable in the up - down direction. At the upper part of each side plate 10, a table drive mechanism 16 for moving the upper table 14 in the up - down direction is provided. The table drive mechanism 16 is, for example, a hydraulic cylinder, but it may also be a servo motor or the like. The upper table 14 only needs to be relatively movable with respect to the lower table 12, and the bending machine 1 may be configured to move the lower table 12 in the up - down direction with the upper table 14 fixed.

[0017] On the upper side of the lower table 12, a lower die holder 18 for detachably holding a lower die 2 such as a die is provided. In the lower die holder 18, a holder groove for inserting the shank portion (base portion) of the lower die 2 is formed along the left - right direction. The lower die holder 18 has a clamping mechanism for fixing the lower die 2.

[0018] On the lower side of the upper table 14, an upper die holder 20 for detachably holding an upper die 4 such as a punch is provided. In the upper die holder 20, a holder groove for inserting the shank portion (base portion) of the upper die 4 is formed along the left - right direction. The upper die holder 20 has a clamping mechanism for fixing the upper die 4.

[0019] On the right side of the bending machine 1, a die storage device 6 is provided adjacent thereto. The die storage device 6 stores a plurality of lower dies 2 and a plurality of upper dies 4.

[0020] FIG. 2 is a perspective view showing a main part of the die storage device 6. FIG. 3 is a side view showing a main part of the die storage device 6. The die storage device 6 includes a main body frame 60, a plurality of lower die stockers 65, and a plurality of upper die stockers 67.

[0021] The main frame 60 comprises a pair of base frames 60a extending in the front-to-back direction, and four support columns 60b that stand upright relative to the base frames 60a.

[0022] Multiple lower die stockers 65 are arranged from front to back along a lower support frame 61 that extends in the front-to-back direction and is provided on the main frame 60. The lower support frame 61 is provided with multiple lower die stocker storage sections (not shown) that support each of the multiple lower die stockers 65. Both ends of the lower die stockers 65 are detachably supported by the lower die stocker storage sections.

[0023] Each lower die stocker 65 extends in the left-right direction and holds one or more lower dies 2. Each lower die stocker 65 holds the lower die 2 in a position where the tip (cutting edge) of the lower die 2 is facing upward. Each lower die stocker 65 can be removed from the lower die stocker storage unit by lifting it upward.

[0024] In addition to the lower die 2 used directly for bending, the lower die stocker 65 can also store cleaning jigs and calibration jigs. The cleaning jig is used to clean the lower die holder 18 by moving along the holder groove of the lower die holder 18. The calibration jig, on the other hand, is used to correct the measurement value of the contact-type angle sensor that measures the bending angle of the workpiece W, and is used by being attached to the lower die holder 18. Since these jigs are used infrequently, it is preferable that they be stored in the rearmost lower die stocker 65 among the multiple lower die stockers 65.

[0025] Multiple upper mold stockers 67 are arranged from front to back along an upper support frame 62 that extends in the front-to-back direction and is provided on the main frame 60. The upper support frame 62 is provided with multiple upper mold stocker storage sections (not shown) that support each of the multiple upper mold stockers 67. Both ends of the upper mold stockers 67 are detachably supported by the upper mold stocker storage sections.

[0026] Each upper die stocker 67 extends in the left-right direction and holds one or more upper dies 4. Each upper die stocker 67 holds the upper die 4 in a position where the tip (cutting edge) of the upper die 4 is facing downward. Each upper die stocker 67 can be removed from the upper die stocker storage unit by lifting it upward.

[0027] The mold changing device 5 exchanges the lower mold 2 between the mold storage device 6 and the lower mold holder 18, and also exchanges the upper mold 4 between the mold storage device 6 and the upper mold holder 20. The mold changing device 5 includes a lower mold station 80 and an upper mold station 90. Note that the upper mold station 90 is omitted in Figures 2 and 3.

[0028] The lower mold station 80 is located in the space below the mold storage device 6, below the multiple lower mold stockers 65. The lower mold station 80 is mounted on a lower station frame 63 that extends in the front-rear direction and is located below the main frame 60.

[0029] The lower mold station 80 selects the target lower mold stocker 65 from among a plurality of lower mold stockers 65. The lower mold station 80 can position the selected lower mold stocker 65 at a predetermined lower mold replacement position by moving it in the vertical and horizontal directions. The lower mold replacement position is set to a position adjacent to the right side of the lower mold holder 18.

[0030] The upper mold station 90 is located in the upper space of the mold storage device 6, above the multiple upper mold stockers 67. The upper mold station 90 is supported by an upper station frame 64 that extends in the front-to-back direction and is positioned above the main frame 60.

[0031] The upper mold station 90 selects the target upper mold stocker 67 from among a plurality of upper mold stockers 67. The upper mold station 90 can position the selected upper mold stocker 67 at a predetermined upper mold replacement position by moving it in the vertical and horizontal directions. The upper mold replacement position is set to a position adjacent to the right side of the upper mold holder 20.

[0032] As shown in Figure 1, the mold changing device 5 further comprises left and right lower mold changing units 55L and 55R, left and right upper mold changing units 56L and 56R, a lower guide 57, and an upper guide 58.

[0033] The left and right lower die exchange units 55L and 55R position the lower die 2 relative to the lower die holder 18. Specifically, the left and right lower die exchange units 55L and 55R move the lower die 2 from the lower die stocker 65 (omitted in Figure 1), which is positioned at the lower die exchange position, to the lower die holder 18, and position the lower die 2 relative to the lower die holder 18. The left and right lower die exchange units 55L and 55R are located on the rear side of the lower table 12.

[0034] The lower guide 57 is fixed to the rear side of the lower table 12. The lower guide 57 extends laterally along the lower mold holder 18. The left and right ends of the lower guide 57 extend laterally beyond the lower mold holder 18.

[0035] The left and right upper mold exchange units 56L and 56R position the upper mold 4 relative to the upper mold holder 20. Specifically, the left and right upper mold exchange units 56L and 56R move the upper mold 4 from the upper mold stocker 67 (omitted in Figure 1), which is positioned at the upper mold exchange position, to the upper mold holder 20, and position the upper mold 4 relative to the upper mold holder 20. The left and right upper mold exchange units 56L and 56R are located on the rear side of the upper table 14.

[0036] The upper guide 58 is fixed to the rear side of the upper table 14. The upper guide 58 extends laterally along the upper mold holder 20. The left and right ends of the upper guide 58 extend laterally beyond the upper mold holder 20.

[0037] The bending machine 1 has a control device 100. The control device 100 is a device that controls the operation of the bending machine 1 and the die changing device 5. The control device 100 is a computer, such as an NC (Numerical Control) device. The computer mainly consists of a hardware processor such as a CPU (Central Processing Unit), memory, and various interfaces. The memory and various interfaces are connected to the hardware processor via a bus.

[0038] The computer has a predetermined computer program installed. The hardware processor executes the computer program, thereby enabling the computer to perform multiple functions provided by the control unit 100.

[0039] The lower mold station 80, one of the features of this embodiment, will now be described with reference to Figure 4. The lower mold station 80 comprises a base portion 81, a pair of guide portions 82, a pair of rods 83, a stocker support portion 85, an air cylinder 86, and an air adjustment unit 87 (not shown in Figure 4), which will be described later.

[0040] Furthermore, the lower mold station 80 is equipped with actuators such as servo motors that move the lower mold station 80 in the forward and backward direction along the lower station frame 63 (see Figure 2).

[0041] The base portion 81 is a member to which a pair of guide portions 82 and an air cylinder 86 are attached. The pair of guide portions 82 are arranged on the base portion 81, spaced apart in the left-right direction. A pair of rods 83 are inserted into the pair of guide portions 82 so as to move along the vertical direction. The pair of rods 83 can move in the vertical direction by being guided by the pair of guide portions 82. The upper end of each rod 83 supports the stocker support portion 85 from below.

[0042] The stocker support section 85 supports the lower mold stocker 65 from below. The stocker support section 85 extends in the left-right direction and is set to a size sufficient to stably support the lower mold stocker 65.

[0043] The air cylinder 86 is an actuator that raises and lowers the stocker support 85. The air cylinder 86 is fixed to the base 81 so as to be aligned in the vertical direction and is positioned between a pair of guide parts 82.

[0044] The air cylinder 86 comprises a cylinder body 860 and an operating rod 861. The cylinder body 860 includes a head-side port for supplying and exhausting air, and a rod-side port for supplying and exhausting air. The operating rod 861 extends upward from the upper end of the cylinder body 860 and moves vertically along the cylinder body 860. The upper end of the operating rod 861 is connected to a stocker support 85.

[0045] The air cylinder 86 moves the operating rod 861 vertically in response to the air supplied from the air adjustment unit 87 (not shown in Figure 4). For example, when air is supplied to the head-side port and exhausted from the rod-side port, the operating rod 861 moves upward. This causes the stocker support 85 and the lower mold stocker 65 supported by it to rise. On the other hand, when air is supplied to the rod-side port and exhausted from the head-side port, the operating rod 861 moves downward. This causes the stocker support 85 and the lower mold stocker 65 supported by it to descend.

[0046] In this embodiment, the movement speed of the operating rod 861 is not constant throughout the entire stroke, but is changed based on the vertical position of the stocker support 85. The vertical position of the stocker support 85 is determined by the stroke position of the operating rod 861.

[0047] The air cylinder 86 is provided with a sensor unit 865 for detecting the stroke position of the operating rod 861. The sensor unit 865 consists of first to fourth switches 865a to 865d that detect the base end (piston) of the operating rod 861. The first to fourth switches 865a to 865d are mounted on the outer circumferential surface of the cylinder body 860. The first to fourth switches 865a to 865d are arranged from top to bottom in the order of first switch 865a, second switch 865b, third switch 865c, and fourth switch 865d.

[0048] Figure 5 is an explanatory diagram showing the configuration of the air adjustment unit. The air adjustment unit 87 adjusts the amount of air exhausted from the head-side port 862 of the cylinder body 860 and the amount of air exhausted from the rod-side port 863 of the cylinder body 860. By adjusting the amount of air, the air adjustment unit 87 adjusts the movement speed of the operating rod 861, that is, the lifting and lowering speed of the stocker support part 85.

[0049] The air adjustment unit 87 includes an upward command valve 870, a downward command valve 871, an upward speed switching valve 872, a downward speed switching valve 873, an upward high-speed controller 874, an upward low-speed controller 875, and a downward low-speed controller 876.

[0050] The upward command valve 870 and the downward command valve 871 are valves for switching the airflow between the upward and downward sides. The upward speed switching valve 872 is a valve that switches the airflow between the upward high-speed controller 874 and the upward low-speed controller 875. The downward speed switching valve 873 is a valve that switches the airflow between the downward low-speed controller 876 and a circuit that bypasses it. The upward high-speed controller 874, the upward low-speed controller 875, and the downward low-speed controller 876 are throttle valves that control the amount of air exhausted from the air cylinder 86.

[0051] Figure 6A is an explanatory diagram showing the operation of the air adjustment unit 87 during high-speed upward movement. In the case of high-speed upward movement in which the stocker support section 85 is raised at high speed, the upward command valve 870, the upward speed switching valve 872, and the downward speed switching valve 873 are turned ON, and the downward command valve 871 is turned OFF. At this time, air from the air supply source is supplied to the head-side port 862 via the upward command valve 870 and the downward speed switching valve 873. Air from the rod-side port 863 is exhausted via the upward speed switching valve 872, the high-speed upward speed controller 874, and the downward command valve 871.

[0052] The air exhausted from the rod-side port 863 flows to the high-speed ascent controller 874 when the ascent speed switching valve 872 is turned on, bypassing the low-speed ascent controller 875. By bypassing the low-speed ascent controller 875, the amount of exhausted air is relatively increased. This allows the operating rod 861 to move upward at high speed, that is, the stocker support section 85 to be raised at high speed. Note that "high speed" refers to a speed that is relatively fast compared to the "low speed" in the "low-speed ascent operation" described later.

[0053] Figure 6B is an explanatory diagram showing the operation of the air adjustment unit 87 during low-speed upward operation. In low-speed upward operation, when the stocker support section 85 is raised at a low speed, the upward command valve 870 and the downward speed switching valve 873 are turned ON, and the downward command valve 871 and the upward speed switching valve 872 are turned OFF. At this time, air from the air supply source is supplied to the head-side port 862 via the upward command valve 870 and the downward speed switching valve 873. Air from the rod-side port 863 is exhausted via the upward speed switching valve 872, the low-speed upward speed controller 875, and the downward command valve 871.

[0054] The air exhausted from the rod-side port 863 flows to the low-speed upward controller 875 when the upward speed switching valve 872 is turned off. Passing through the low-speed upward controller 875 reduces the amount of air exhausted. This allows the operating rod 861 to move upward at a slow speed, that is, the stocker support section 85 to be raised at a slow speed. Note that "low speed" refers to a speed that is relatively slow compared to "high speed" in "high-speed upward operation".

[0055] As shown in Figures 6A and 6B, during ascent, the air path from the ascent command valve 870 to the descent speed switching valve 873 is designed so that it does not pass through the speed controller. This prevents the throttle effect of the speed controller from occurring. Also, as shown in Figure 6A, during high ascent, the air exhausted from the rod-side port 863 passes through the high-speed ascent speed controller 874. This helps to mitigate the impact of the air when switching speeds.

[0056] Figure 6C is an explanatory diagram showing the operation of the air adjustment unit 87 during high-speed descent. In the case of high-speed descent operation in which the stocker support section 85 is lowered at high speed, the descent command valve 871, the ascending speed switching valve 872, and the descent speed switching valve 873 are turned ON, and the ascending command valve 870 is turned OFF. At this time, air from the air supply source is supplied to the rod-side port 863 via the descent command valve 871, the ascending high-speed controller 874, and the ascending speed switching valve 872. Air from the head-side port 862 is exhausted via the descent speed switching valve 873 and the ascending command valve 870.

[0057] The air exhausted from the head-side port 862 bypasses the low-speed descent controller 876 when the descent speed switching valve 873 is turned on. By bypassing the low-speed descent controller 876, the amount of exhausted air is relatively increased. This allows the operating rod 861 to move downward at high speed, that is, the stocker support section 85 to descend at high speed. Note that "high speed" refers to a speed that is relatively fast compared to the "low speed" in the "low-speed descent operation" described later.

[0058] Figure 6D is an explanatory diagram showing the operation of the air adjustment unit 87 during low-speed descent. In low-speed descent operation, when the stocker support section 85 is lowered at a low speed, the descent command valve 871 and the ascending speed switching valve 872 are turned ON, and the ascending command valve 870 and the descent speed switching valve 873 are turned OFF. At this time, air from the air supply source is supplied to the rod-side port 863 via the descent command valve 871, the ascending speed controller 874, and the ascending speed switching valve 872. Air from the head-side port 862 is exhausted via the descent speed switching valve 873, the descending speed controller 876, and the ascending command valve 870.

[0059] In this way, the air exhausted from the head-side port 862 flows to the low-speed descent controller 876 when the descent speed switching valve 873 is turned off. By passing through the low-speed descent controller 876, the amount of air exhausted is relatively reduced. This allows the operating rod 861 to move downward at a slow speed, that is, the stocker support section 85 to descend at a slow speed. Note that "low speed" refers to a speed that is relatively slow compared to "high speed" in "high-speed descent operation".

[0060] As shown in Figures 6C and 6D, during descent, the path from the descent command valve 871 to the ascending speed switching valve 872 is designed so that air does not substantially pass through the ascending high-speed controller 874. This prevents the throttle valve of the ascending high-speed controller 874 from having any effect.

[0061] Figure 7 is an explanatory diagram illustrating the operational concept of the lower mold station. The operation of the lower mold station 80, that is, the transport operation of the lower mold stocker 65, will be described below. This operation is performed by the lower mold station 80 under the control of the control device 100.

[0062] As shown in Figure 7, in the mold storage device 6, multiple lower mold stockers 65 are arranged adjacent to each other in the front-to-back direction. At this time, each lower mold stocker 65 is positioned close to one of the lower mold stockers 65 on the front side or rear side, but at a certain distance from the other lower mold stocker 65. This ensures a space (hereinafter referred to as the "stocker space") between adjacent lower mold stockers 65. By utilizing this stocker space, the lower mold station 80 can transport the lower mold stockers 65 in the vertical direction.

[0063] First, we will explain the operation of transporting the lower mold stocker 65, which is supported by the lower mold stocker storage unit, to the mold change position. Here, the storage position in which the lower mold stocker storage unit supports the lower mold stocker 65 is defined as the home position P0 and used as the reference for the vertical position. Initially, the stocker support unit 85 of the lower mold station 80 is assumed to be at a position below the mold change position, for example, at the lower limit position P4. This lower limit position P4 is the position in which the descent of the stocker support unit 85 is stopped, and is set, for example, at a position 225 mm below the home position P0. Note that the lower limit position P4 is also the position corresponding to the lower end of the stroke of the operating rod 861.

[0064] The control device 100 moves the stocker support unit 85 in the rearward direction. When the stocker support unit 85 reaches a position below the lower mold stocker 65 to be transported, the control device 100 stops the stocker support unit 85. Next, the control device 100 raises the stocker support unit 85. When the stocker support unit 85 passes the home position P0, the stocker support unit 85 lifts the lower mold stocker 65 upward. As a result, the lower mold stocker 65 moves upward and is removed from the lower mold stocker storage unit.

[0065] When the stocker support 85 reaches the upper limit position P1, the control device 100 stops the stocker support 85. The upper limit position P1 is the position where the upward movement of the stocker support 85 is stopped, and is set, for example, 145 mm upward from the home position P0. The upper limit position P1 is also the position corresponding to the upper end of the stroke of the operating rod 861, and also the position corresponding to the lower mold exchange position (pass line).

[0066] Next, the control device 100 moves the stocker support 85 forward or backward. When the stocker support 85 reaches an upper position in the stocker space between it and the adjacent lower mold stocker 65, the control device 100 stops the stocker support 85. Then, the control device 100 lowers the stocker support 85. When the stocker support 85 reaches the lower limit position P4, the control device 100 stops the stocker support 85.

[0067] The control device 100 moves the stocker support 85 forward. When the stocker support 85 reaches below the lower mold exchange position, the control device 100 stops the stocker support 85. Next, the control device 100 raises the stocker support 85. When the stocker support 85 reaches the mold exchange position (upper limit position P1), the control device 100 stops the stocker support 85.

[0068] The operation of transporting the lower mold stocker 65, which is located at the mold exchange position, to the lower mold stocker storage section is the reverse of the series of operations described above. Therefore, a detailed explanation will be omitted.

[0069] During this series of movements of the stocker support section 85, the control device 100 controls the speed of the lifting and lowering operation of the stocker support section 85. Specifically, the control device 100 controls the lifting and lowering speed of the stocker support section 85 by controlling the air adjustment unit 87 based on the stroke position detected by each switch 865a to 865d.

[0070] Here, the stroke position detected by the first switch 865a corresponds to the upper limit position P1 of the stocker support 85. The stroke position detected by the second switch 865b corresponds to the upper speed switching position P2 of the stocker support 85. The upper speed switching position P2 is set between the home position P0 and the upper limit position P1, for example, at a position 100 mm upward from the home position P0. The stroke position detected by the third switch 865c corresponds to the lower speed switching position P3 of the stocker support 85. The lower speed switching position P3 is set between the home position P0 and the lower limit position P4, for example, at a position 50 mm downward from the home position P0. The stroke position detected by the fourth switch 865d corresponds to the lower limit position P4 of the stocker support 85.

[0071] First, we will explain the operation of transporting the lower mold stocker 65, which is stored in the mold storage device 6, to the mold exchange position.

[0072] When removing the lower mold stocker 65, the stocker support section 85 is located below the lower mold stocker 65. The control device 100 raises the stocker support section 85 from the lower limit position P4. At this time, the control device 100 raises the stocker support section 85 at high speed. When the control device 100 determines, via the third switch 865c, that the stocker support section 85 has reached the lower speed switching position P3, it controls the air adjustment unit 87 to switch the speed. Then, the control device 100 raises the stocker support section 85 at a low speed. Therefore, from the lower speed switching position P3 to the upper limit position P1, the stocker support section 85 rises at a low speed.

[0073] Once the stocker support section 85 reaches the upper limit position P1, it moves in the front-rear direction to reach an upper position of the stocker space, and then descends. At this time, the control device 100 causes the stocker support section 85 to descend at high speed from the upper limit position P1 to the lower limit position P4.

[0074] Once the stocker support 85 reaches the lower limit position P4, it moves forward to reach below the mold exchange position, and then rises. At this time, the control device 100 raises the stocker support 85 at high speed from the lower limit position P4 to the lower speed switching position P3, similar to when removing the lower mold stocker 65. The control device 100 changes the speed at the lower speed switching position P3 and raises the stocker support 85 at a low speed from the lower speed switching position P3 to the upper limit position P1.

[0075] Next, we will explain the operation of transporting the lower mold stocker 65, which is located at the mold exchange position, to the lower mold stocker storage section of the mold storage device 6.

[0076] The control device 100 rapidly lowers the stocker support section 85 from the mold exchange position (upper limit position P1) to the lower limit position P4.

[0077] When the stocker support section 85 reaches the lower limit position P4, it moves backward and reaches the lower position of the stocker space, after which it rises. At this time, the control device 100 raises the stocker support section 85 at high speed. When the control device 100 determines that the stocker support section 85 has reached the upper speed switching position P2 by the second switch 865b, it controls the air adjustment unit 87 to switch the speed. Then, the control device 100 raises the stocker support section 85 at a low speed. Therefore, between the upper speed switching position P2 and the upper limit position P1, the stocker support section 85 rises at a low speed.

[0078] When the stocker support section 85 reaches the upper limit position P1, it moves in the front-rear direction to reach the position above the lower mold stocker storage section, and then descends. At this time, the control device 100 lowers the stocker support section 85 at a low speed. When the control device 100 determines, via the third switch 865c, that the stocker support section 85 has reached the lower speed switching position P3, it controls the air adjustment unit 87 to switch the speed. Then, the control device 100 lowers the stocker support section 85 at high speed. Therefore, the stocker support section 85 descends at high speed from the lower speed switching position P3 to the lower limit position P4.

[0079] In this manner, the control device 100 moves the stocker support unit 85 vertically and longitudinally to transport the lower mold stocker 65 located in the lower mold stocker storage unit to the lower mold replacement position, or to transport the lower mold stocker 65 located in the lower mold storage position to the lower mold stocker storage unit. At this time, the control device 100 controls the lifting and lowering speed of the stocker support unit 85 by controlling the air adjustment unit 87 based on the stroke position of the operating rod 861.

[0080] With this configuration, the lifting speed can be switched according to the position of the stocker support 85. At low lifting speeds, displacement or dropping of the lower mold 2 held by the lower mold stocker 65 can be suppressed, resulting in the advantage of stable transport operation of the lower mold stocker 65. On the other hand, at high lifting speeds, the lower mold stocker 65 can be transported quickly, resulting in the advantage of shortening the replacement time for the lower mold 2. This makes it possible to achieve both stable transport operation of the lower mold stocker 65 and shortened replacement time for the lower mold 2.

[0081] In this embodiment, the lower mold stocker 65 is supported by the lower mold stocker storage section within the mold storage device 6. When the lower mold stocker 65 is removed from the lower mold stocker storage section by raising the stocker support section 85 from a position below the lower mold stocker 65, the control device 100 raises the stocker support section 85 at high speed (an example of a first speed) to a lower speed switching position P3 (an example of a first speed switching position) which is below the storage position (home position P0) where the lower mold stocker storage section supports the lower mold stocker 65. From the lower speed switching position P3, the control device 100 raises the stocker support section 85 at low speed (a speed slower than the first speed) to an upper limit position P1 where the raising of the stocker support section 85 is stopped.

[0082] With this configuration, when passing the home position P0, the stocker support section 85 rises at a low speed, which mitigates the impact when the stocker support section 85 lifts the lower mold stocker 65. This suppresses the generation of impact noise. In addition, the impact on the lower mold 2 held by the lower mold stocker 65 is also mitigated, which suppresses displacement or dropping of the lower mold 2. On the other hand, it rises at high speed until it reaches the lower speed switching position P3, allowing the lower mold stocker 65 to be transported quickly. This makes it possible to achieve both stable transport operation of the lower mold stocker 65 and a reduction in the replacement time of the lower mold 2.

[0083] In this embodiment, when lowering the stocker support portion 85 from an upper position above the lower mold stocker storage portion provided in the mold storage device 6 to store the lower mold stocker 65 in the lower mold stocker storage portion, the control device 100 lowers the stocker support portion 85 at a low speed (an example of the second speed) to a lower speed switching position P3 (an example of the second speed switching position) which is below the storage position (home position P0) where the lower mold stocker storage portion supports the lower mold stocker 65, and then lowers the stocker support portion 85 at a high speed (a speed faster than the second speed) from the lower speed switching position P3 to a lower limit position P4 where the descent of the stocker support portion 85 stops.

[0084] With this configuration, when passing the home position P0, the stocker support section 85 descends at a low speed, which mitigates the impact when storing the lower mold stocker 65 into the lower mold stocker storage section. This suppresses the generation of impact noise. Furthermore, the impact on the lower mold 2 held by the lower mold stocker 65 is also mitigated, which suppresses displacement or dropping of the lower mold 2. On the other hand, after passing the lower speed switching position P3, it descends at high speed, allowing the lower mold stocker 65 to be transported quickly. This makes it possible to achieve both stable transport operation of the lower mold stocker 65 and a reduction in the replacement time of the lower mold 2.

[0085] In this embodiment, when raising the stocker support 85 from a position below the lower mold exchange position to position the lower mold stocker 65 to the lower mold exchange position, the control device 100 raises the stocker support 85 at high speed (an example of the first speed) to a lower speed switching position P3 (an example of the third speed switching position) which is below the lower mold exchange position, and then raises the stocker support 85 at low speed (a speed slower than the first speed) from the lower speed switching position P3 to the mold exchange position (upper limit position P1).

[0086] With this configuration, when reaching the lower mold exchange position, the stocker support 85 rises at a low speed, thus mitigating the impact when positioning the lower mold stocker 65 to the lower mold exchange position. The lower mold holder 18 side has a positioning component for positioning the lower mold stocker 65. Therefore, the impact when positioning the lower mold stocker 65 to the lower mold exchange position can be mitigated. This suppresses the generation of impact noise. In addition, by appropriately decelerating the stocker support 85, the lower mold stocker 65 can be smoothly transferred to the lower mold holder 18 side. The impact on the lower mold 2 held by the lower mold stocker 65 is also mitigated, so displacement or dropping of the lower mold 2 can be suppressed. In particular, since the lower mold 2 that has been transported to the lower mold exchange position is held by the lower mold exchange units 55L and 55R, the occurrence of displacement of the lower mold 2 is suppressed, and the lower mold exchange units 55L and 55R can reliably hold the lower mold 2. On the other hand, since it rises at high speed until it passes the lower speed switching position P3, the lower mold stocker 65 can be transported quickly. This makes it possible to achieve both stable transport operation of the lower mold stocker 65 and a reduction in the replacement time of the lower mold 2.

[0087] As shown in Figure 4, the lower mold stocker 65 is equipped with a restricting member 650 that restricts the positional displacement of the lower mold 2 held on the lower mold stocker 65. Except at the mold change position, the restricting member 650 is in operation, so the occurrence of positional displacement of the lower mold 2 is suppressed during the transport operation of the lower mold stocker 65.

[0088] In this embodiment, when raising the stocker support 85 from a position below the stocker space provided on the front or rear side of the lower mold stocker 65 to an upper limit position P1 where the raising of the stocker support 85 is stopped, the control device 100 raises the stocker support 85 at high speed (first speed) to an upper speed switching position P2 (an example of a fourth speed switching position) which is below the upper limit position P1, and then raises the stocker support 85 at low speed (a speed slower than the first speed) from the upper speed switching position P2 to the upper limit position P1.

[0089] With this configuration, when the lower die stocker 65 reaches the upper limit position P1, the stocker support 85 rises at a low speed, which mitigates the impact when the lower die stocker 65 reaches the upper limit position P1. This prevents the lower die 2 from bouncing up due to inertia, causing it to shift position or fall from the lower die stocker 65. On the other hand, it rises at high speed until it passes the upper speed switching position P2, allowing the lower die stocker 65 to be transported quickly. This makes it possible to achieve both stable transport operation of the lower die stocker 65 and a reduction in the replacement time of the lower die 2.

[0090] In this embodiment, when lowering the lower mold stocker 65 from the lower mold exchange position, the control device 100 lowers the stocker support portion 85 at a constant speed without switching to a lower speed.

[0091] With this configuration, the speed is not switched to the low-speed side between the lower mold replacement position and the lower limit position P4. This makes it possible to shorten the replacement time for the lower mold 2.

[0092] In this embodiment, when lowering the stocker support portion 85 from an upper position of the stocker space portion provided on the front or rear side of the lower mold stocker 65 to the lower limit position P4 where the descent of the stocker support portion 85 stops, the control device 100 lowers the stocker support portion 85 at a constant speed without switching to a lower speed.

[0093] With this configuration, the speed is not switched to the low-speed side between the upper position of the stocker space and the lower limit position P4. This makes it possible to shorten the replacement time of the lower mold 2.

[0094] In the embodiment described above, a speed controller was used as part of the air adjustment unit 87. However, the method for adjusting the amount of air is not limited to this, and a fixed throttle or regulator may also be used.

[0095] Furthermore, in the embodiment described above, the lower speed switching position P3 was used as an example for the first speed switching position, the second speed switching position, and the third speed switching position. However, the first speed switching position, the second speed switching position, and the third speed switching position do not need to be the same position, and may be set to different positions.

[0096] As described above, embodiments of the present invention have been presented, but the statements and drawings that constitute part of this disclosure should not be understood as limiting the invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure. [Explanation of Symbols]

[0097] 1 Bending machine 2 Lower mold 4 Upper mold 18 Lower mold holder 20 Upper mold holder 5. Mold changing device 55L, 55R Lower mold replacement unit 56L, 56R Upper mold change unit 57 Lower Guide 58 Top Guide 80 Lower mold station 85 Stocker support section 86 Air Cylinder 860 Cylinder body 861 Operating rod 862 Head-side port 863 Rod-side port 865 Sensor Unit 87 Air adjustment unit 870 Raising command valve 871 Downward command valve 872 Ascent speed switching valve 873 Descent speed switching valve 874, 875, 876 Speed ​​Controller 90 Upper mold station 6. Mold storage device 65 Lower mold stocker 67 Upper mold stocker Double job

Claims

1. A mold exchange device that exchanges molds between a mold storage device provided with multiple mold stockers for holding molds and a mold holder for mounting the molds on the table of a bending machine, A mold station that takes a target mold stocker from among the multiple mold stockers arranged in the front-to-back direction and transports the mold stocker to a mold exchange position set to the side of the mold holder, The system includes a control device for controlling the operation of the mold station, The aforementioned mold station is A stocker support section that supports the mold stocker from below, An air cylinder moves an operating rod connected to the stocker support in the vertical direction to raise and lower the stocker support, An air adjustment unit that adjusts the amount of air exhausted from the air cylinder and the amount of air supplied to the air cylinder, It has a sensor unit for detecting the stroke position of the operating rod, The control device is The air adjustment unit is controlled based on the stroke position to control the lifting and lowering speed of the stocker support, When transporting the mold stocker, which is supported by the mold stocker storage section within the mold storage device, to the mold replacement position, When removing the mold stocker from the mold stocker storage section by raising the stocker support from the lower limit position where the stocker support stops descending at a lower position of the mold stocker, The control device is The stocker support is raised at a first speed to a first speed switching position where the mold stocker storage section is below the storage position where the mold stocker supports the mold stocker. From the first speed switching position to the upper limit position where the rise of the stocker support is stopped, the stocker support is raised at a speed slower than the first speed. When lowering the stocker support portion from the upper limit position to the lower limit position, above the stocker space portion provided on the front or rear side of the mold stocker, The control device is The stocker support is lowered at a constant speed without switching to a lower speed. When, at a position below the mold exchange position, the stocker support is raised from the lower limit position to position the mold stocker at the mold exchange position, The control device is The stocker support is raised at the first speed to a third speed switching position located below the mold exchange position. From the third speed switching position to the mold replacement position, the stocker support is raised at a speed slower than the first speed. The first speed switching position and the third speed switching position are set to the same position in the vertical direction. The mold exchange position and the upper limit position are set to the same position in the vertical direction. Mold changing device.

2. The control device is When the stocker support rises from the lower position of the mold stocker to the upper limit position, the stocker support is moved back and forth to the upper position of the stocker space. When the stocker support portion descends to the lower limit position, the stocker support portion is moved back and forth to a position below the mold exchange position. The mold changing device according to claim 1.

3. A mold exchange device that exchanges molds between a mold storage device provided with multiple mold stockers for holding molds and a mold holder for mounting the molds on the table of a bending machine, A mold station that takes a target mold stocker from among the multiple mold stockers arranged in the front-to-back direction and transports the mold stocker to a mold exchange position set to the side of the mold holder, The system includes a control device for controlling the operation of the mold station, The aforementioned mold station is A stocker support section that supports the mold stocker from below, An air cylinder moves an operating rod connected to the stocker support in the vertical direction to raise and lower the stocker support, An air adjustment unit that adjusts the amount of air exhausted from the air cylinder and the amount of air supplied to the air cylinder, It has a sensor unit for detecting the stroke position of the operating rod, The control device is The air adjustment unit is controlled based on the stroke position to control the lifting and lowering speed of the stocker support, When transporting the mold stocker located at the mold exchange position to the mold stocker storage section within the mold storage device, When lowering the mold stocker from the mold exchange position to the lower limit position where the lowering of the stocker support portion stops, The control device is The stocker support is lowered at a constant speed without switching to a lower speed. When the mold stocker storage section is located below the stocker space provided on the front or rear side of the storage position that supports the mold stocker, and the stocker support section is raised from the lower limit position to the upper limit position where the stocker support section stops rising, The control device is The stocker support is raised at the first speed to a fourth speed switching position which is below the upper limit position. The stocker support is raised from the fourth speed switching position to the upper limit position at a speed slower than the first speed. When lowering the stocker support from the upper limit position to store the mold stocker in the mold stocker storage section, The control device is The stocker support is lowered at the second speed to a second speed switching position which is below the aforementioned storage position. The stocker support is lowered from the second speed switching position to the lower limit position at a speed faster than the second speed. The second speed switching position and the fourth speed switching position are set to different positions in the vertical direction. The mold exchange position and the upper limit position are set to the same position in the vertical direction. Mold changing device.

4. The control device is When the stocker support portion descends from the mold exchange position to the lower limit position, the stocker support portion is moved back and forth to a position below the stocker space portion. When the stocker support rises to the upper limit position, the stocker support is moved back and forth to a position above the mold stocker storage section. The mold changing device according to claim 3.

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