Pallet Work Storage System

Abstract

To provide a system capable of correctly storing pallet works in storage positions allocated according to the storage arrangement pattern of a work storage shelf. [Solution] In a pallet work storage system equipped with a storage shelf (11) and an automatic pallet exchanger, pallet storage jigs (20) are fixed to each shelf (14) provided on the storage shelf so that the longitudinal spacing can be changed, a wireless recording medium is attached to each pallet and work information including a storage arrangement pattern set according to the type of work fixed to the pallet is stored in advance, and immediately after the transportation of each pallet work from the setup table to the storage shelf begins, the storage control device reads the wireless recording medium and moves the pallet work by the automatic pallet exchanger so that it passes through a data read position by the equipment, and based on the read work information, commands the automatic pallet exchanger to store the pallet work in the storage position indicated by the address assigned to the pallet work being transported.

Description

[Technical Field]

[0001] The present invention relates to a pallet work storage system that includes a storage shelf for storing multiple pallet workpieces in a workpiece storage section adjacent to the machining section of a machine tool, and an automatic pallet exchange device for storing each pallet workpiece in a pre-assigned storage position on the storage shelf. More specifically, the present invention relates to a storage system in which the storage layout pattern of the storage shelf can be changed according to the type of workpiece, and which can store the pallet workpiece correctly with high precision in the assigned storage position according to the changed storage layout pattern. [Background technology]

[0002] Machining centers are equipped with computerized numerical control (CNC) devices, and the machining section of the machine tool automatically performs cutting processing on workpieces according to a preset NC machining program using numerical control from the CNC device. At the same time, an automatic tool changer is also driven and controlled, and a specified tool is appropriately changed in conjunction with the cutting process. In such automatic operation, the loading and unloading of workpieces and the removal of machined workpieces are also automated by the automatic work changer and automatic pallet changer.

[0003] The workpieces to be machined are usually handled in pallet units, with each pallet workpiece fixed to a pallet of a size corresponding to the workpiece on a setup table located in a corner of a storage shelf.When machining is carried out continuously for long periods of time while changing a large number of pallet workpieces like this, in order to improve the efficiency of the work, a storage shelf that can store multiple pallet workpieces in advance is installed next to the machining section of the machine tool.

[0004] In this storage shelf, each shelf is set up as a preparatory step before the execution of a predetermined continuous processing process, and then, as a preparatory step immediately before that, multiple pallet workpieces to be processed are stored in the storage positions of each shelf. Then, the continuous processing process begins with all unmachined workpieces stored in the storage shelf.

[0005] While continuous machining processes are being carried out by automatic operation of the machine tool, the automatic pallet changer responds to pallet change commands incorporated into the NC machining program by using its robot arm to remove pallet workpieces from the storage shelf at storage position addresses called up in the order according to a preset transport program and carry them into the machining area, and then removes the pallet workpieces from the machining area after machining and returns them to the storage shelf.

[0006] Storage shelves typically have multiple shelves arranged in parallel, one above the other, on which pallet workpieces are placed. However, if the shape and size of the target product change, the size of the workpieces to be processed will also change. For this reason, it is desirable for the storage shelf to be able to change its storage configuration depending on the size of the target workpieces for each processing step for workpieces of different sizes.

[0007] Patent document 1 discloses a work storage device provided on a machine tool in which at least some of the shelves arranged in multiple tiers on multiple vertically extending supports are removable, and the size of the storage space can be changed by moving the mounting positions of the removable shelves vertically. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-280042 Summary of the Invention [Problem to be solved by the invention]

[0009] In conventional storage systems, where the shelf mounting position can be moved vertically, the spacing between the upper and lower shelves can be changed, making it possible to change the storage layout pattern to match the height of the target work. However, since changes in the size of the target work often involve changes not only in height but also in width, depending on the structure of the storage space, it may become necessary to change the horizontal width as well.

[0010] On the other hand, the most efficient storage configuration for a storage shelf is one in which each shelf is a long, narrow rectangle that can hold multiple pallet workpieces, and these shelves are arranged in parallel in multiple levels vertically. In this case, the internal storage space can be made roughly rectangular, and the storage shelf itself can be made roughly cabinet-shaped, allowing for efficient use of the occupied space.

[0011] In the case of such storage shelves, it is desirable not only to be able to change the vertical storage spacing in accordance with the height of the work by moving the mounting position of the shelves up and down as in the past, but also to be able to change the horizontal storage spacing of the pallet work on each shelf in accordance with changes in the width dimension of the target work.

[0012] The storage space disclosed in Patent Document 1 is configured so that one workpiece can be placed on one shelf, and while each shelf can accommodate workpieces of various widths as long as it has a certain width, it does not consider the placement of multiple workpieces. This is because in Patent Document 1, the shelves are moved using a work exchange device to change the vertical mounting position of the shelves. Therefore, the number of works that can be stored in the work storage device is limited to the maximum number of shelves in the vertical direction, and the number in the horizontal direction cannot be increased, so efficiency improvements such as storing more workpieces cannot be expected.

[0013] On the other hand, actual workpieces are handled as a single unit, each fixed to a pallet, and are stored and transported in pallet units. Therefore, in storage shelves, pallet storage jigs adapted to the shape of the target pallet are attached at predetermined positions on each shelf so that each pallet workpiece can be removably and stably stored in the storage shelf via the pallet. This pallet storage jig has a width corresponding to the size of the target workpiece and has a pallet receiving portion on which the pallet is removably seated.

[0014] Specifically, the pallet has a disk-shaped table portion on the top surface of which the workpiece is fixed, and a pull bolt protruding downward from the center of the back surface of the table. On the other hand, the pallet storage jig has a fixed plate portion that has a width roughly equal to the width of the target workpiece and is fixed to a shelf board, and a cylindrical pallet receiving portion protruding from the top surface of the fixed plate portion, the upper part of which forms a dish-shaped seat that fits into the lower part of the table portion.

[0015] A groove is formed in the center of this seating section in the diameter direction to receive the pull bolt when the table section is seated. By inserting the pull bolt into this groove and seating the lower part of the table section of the pallet on the seating section, the pallet workpieces are removably stored in the pallet storage jig. Therefore, each pallet workpiece is efficiently stored on the shelf boards in a stable state with appropriate spacing via the pallet storage jig.

[0016] Furthermore, when removing pallet workpieces from the pallet storage jig at each storage position, the automatic workpiece exchange device has the hand at the tip of its robot arm grasp the table portion of the pallet from both sides, and while slightly lifting it vertically from the pallet receiving portion, remove it horizontally until the pull bolts are completely removed from the grooves. The pallet workpieces thus released from the pallet storage jig can then be moved in any direction.

[0017] Typically, the pallet storage jig is also removably fixed to each shelf in advance. The fixing positions are determined so as to have intervals set according to the storage positions of the multiple pallet workpieces. The fixing method is generally to fit protrusions formed on the underside of the pallet storage jig into through holes formed in the shelf at each set position, and then screw the bottom of the pallet storage jig to the shelf.

[0018] Therefore, if the workpieces are changed to ones with different width dimensions and the workpiece storage intervals on the shelves that determine the storage positions are also changed, the fixed positions and number of fixations on the shelves of the pallet storage jig will also change depending on the changed storage positions and number of workpieces on the pallet.In other words, the positions and number of through holes formed in the shelves as fixing positions for the pallet storage jig must be changed.

[0019] Therefore, it is necessary to prepare in advance a plurality of types of shelf groups with the through holes at various fixed intervals in the horizontal direction corresponding to the storage arrangement pattern for each type of workpiece. Therefore, in the preparation work before executing the continuous processing process, first, a shelf group corresponding to the width dimension of the target workpieces for that processing process must be selected from each shelf group and replaced with the shelf group in the storage shelf.

[0020] In practice, the existing shelf group must be removed, and then the protrusions of the pallet storage jig must be fitted into the through-holes of each newly selected shelf group and screwed into place. Then, each shelf with the pallet storage jig attached must be installed in the storage shelf at a mounting position that corresponds to the desired vertical spacing. Thus, when changing the horizontal spacing of the storage shelf to change the storage arrangement pattern, the preparation work is complicated and takes a lot of time and effort.

[0021] Furthermore, preparing multiple shelves of different types not only increases the number of manufacturing processes, but also requires space to store unused shelf types, which increases costs. Therefore, even if the actual continuous processing process itself is made more efficient, considering the costs associated with the complicated preparation work and storage, adapting storage shelves to different storage arrangement patterns may end up being inefficient when viewed from the overall process of creating the desired product.

[0022] When the storage spacing is changed both vertically and horizontally as described above, the storage positions within the storage shelf will be significantly different from before the change, resulting in a different storage arrangement pattern. In other words, each storage position in the coordinate system within the same storage shelf must be changed, and the address numbers indicating each storage position must also be changed. The addresses used here indicate each storage position within the storage shelf and are expressed, for example, as a combination of the shelf level number in the vertical direction of the shelf and the column number in the horizontal direction (longitudinal direction) of each shelf. In this case, each address can be linked to a coordinate position in the coordinate system of the automatic pallet exchanger for positioning the hand unit.

[0023] The automatic pallet changer transports pallet workpieces by taking them out and returning them to their storage positions on the actual coordinates indicated by the addresses in the order of predetermined addresses in accordance with a transport program corresponding to a specified storage arrangement pattern. Therefore, if the storage arrangement pattern is changed, the transport program must also be changed accordingly.

[0024] Typically, if the desired product form differs, the type of workpiece used as material will also differ, and NC machining programs will be prepared to execute the machining processes required to achieve that desired product. Furthermore, if there are no changes to the storage layout pattern on the storage shelf, the transport program itself, which is linked to the NC machining program and sets the order in which workpieces are loaded onto the pallet, does not need to be changed, and the same program can be used. However, if the storage layout pattern differs depending on the type of workpiece, a separate transport program is required to accommodate each different storage layout pattern, and the transport program will need to be changed as the storage layout pattern changes.

[0025] However, such changes to the transport program can be made in conjunction with changes to the NC machining program.The automatic pallet changer is driven in accordance with the transport program changed to suit the storage arrangement pattern of the storage shelf corresponding to the type of workpiece, so that it is linked to the NC machining program changed according to the type of workpiece.Therefore, the work of transporting pallet workpieces from each storage position by the automatic pallet changer and changing them in the machining section can be smoothly and sequentially carried out in conjunction with the continuous machining process.

[0026] However, this kind of good continuous supply of pallet workpieces to the processing section can only be achieved if pallet workpieces are stored correctly in all storage positions in the changed storage layout pattern. This is because if all pallet workpieces are not stored in the correct storage positions, there is a risk that the continuous supply of pallet workpieces from each storage position to the processing section will be interrupted during the subsequent continuous processing steps.

[0027] In particular, if the workpieces stored in a storage shelf are not all of the same shape, a mix-up of the pallet workpieces to be transported can delay workpiece exchange and require the machining process to be stopped. This can occur when workpieces of different sizes are stored in the same storage shelf, for example, when two different machining processes are carried out consecutively on small numbers of workpieces of two different sizes. In this case, the storage arrangement pattern becomes a special one in which two types of storage areas with different vertical storage spacing and / or fixed horizontal spacing are included within the same storage shelf.

[0028] For this reason, it is conceivable that a relatively small workpiece may be mistakenly stored in a storage location with a relatively large storage space instead of in its assigned storage location. In this case, the automatic pallet changer will transport the pallet workpiece that was in the storage location where the type of workpiece corresponding to the currently executed machining process should have been stored in accordance with the transport program corresponding to the set storage layout pattern to the machining section, but since it is the wrong type and size of pallet workpiece, the correct machining process cannot be continued.

[0029] To avoid this, in the preparation process immediately before the processing process, it is necessary to check whether all pallet work stored in the storage shelf has been stored in the correct storage position with an appropriate storage space, and if it is found that it has been stored in the wrong storage position, it must be stored again. Also, if, during the storage process, the storage position where the pallet work is being stored and transported is an incorrect position with a storage space that is too small to fit the pallet work, the storage process must be stopped, the incorrect transport state must be corrected, and the pallet work must be transported again.

[0030] Furthermore, when the type of workpiece changes, the transport program must also be changed to a storage arrangement pattern that is appropriate for that workpiece.However, if this change is not appropriate, the storage arrangement pattern used to control the drive of the automatic pallet exchanger will differ from the storage arrangement pattern of the actual storage shelf.In this case, during the storage process of the preparation process, the pallet workpieces will be transported to a position that is different from the actual storage position.As a result, the worker will only notice the mistake when it actually occurs, stop the storage process, correct the original misaligned transport state, and then change the transport program to the correct storage arrangement pattern.

[0031] As described above, the re-storing and re-transporting tasks require manual intervention, which causes delays in the automated parts of the storage process. If the storage process is delayed in this way, the entire preparation process will take longer, and the transition to the subsequent continuous processing process will not proceed smoothly as planned. This will result in a decrease in the efficiency of the entire manufacturing process of the target product due to workpiece cutting.

[0032] Therefore, in a storage shelf whose storage arrangement pattern can be changed as the type of workpiece changes, a system is desired that can always store pallet workpieces correctly with high precision in each storage position that makes up the pattern, no matter what the storage arrangement pattern is changed to.However, no pallet workpiece storage system with an automatic pallet changer that can respond efficiently with high precision when the storage arrangement pattern on the storage shelf is changed as the type of workpiece changes has been realized.

[0033] In view of the above problems, the object of the present invention is to provide a pallet work storage system in which the storage arrangement pattern of pallet work on a storage shelf can be easily changed in accordance with the type of work of different sizes, and in which the storage of pallet work in a predetermined storage position on a storage shelf by an automatic pallet changer can always accommodate a changed storage arrangement pattern, and can be executed correctly, highly accurately, and efficiently regardless of the type of storage arrangement pattern. [Means for solving the problem]

[0034] The present invention provides a pallet work storage system attached to a machine tool that is numerically controlled by a computer numerical control device, a work storage section installed adjacent to the machining section of the machine tool; and a setup table provided at one end of the work storage section, for loading and unloading workpieces one by one from the outside, and for fixing the workpieces to corresponding pallets to form an integrated pallet workpiece; The work storage section includes a storage shelf that is installed in an area facing the processing section and stores a plurality of the pallet workpieces on a plurality of shelves, and an automatic pallet exchange device that transports the pallet workpieces between the setup table and the storage shelf and between the storage shelf and the processing section, The storage shelf is provided with removable shelves so that the vertical mounting intervals can be changed, and an opening is provided in a rear wall portion facing the processing section across the automatic pallet changer, through which the shelf can be directly taken in and out from the outside and attached and detached, and an access door is provided to close the opening in an openable and closable manner, A pallet storage jig, in which the pallet workpieces are removably stored, is fixed to each of the shelves in a replaceable manner so that the longitudinal spacing of the shelf can be changed. Each of the pallets is fitted with a wireless recording medium on which various data is stored, and work information relating to the type of work fixed to the pallet is stored in advance in this wireless recording medium, and the work information includes at least a storage arrangement pattern within the storage shelf that is set in advance corresponding to the type of work, and an address that indicates a storage position assigned to each pallet work in the storage arrangement pattern, The system is further equipped with a reading device that reads the work information from the wireless recording medium by wireless communication, and a storage control device that controls the automatic pallet exchange device to transport the pallet work based on the work information read by the reading device, The storage control device is characterized in that, immediately after the transportation of each pallet work from the setup table to the storage shelf begins, the automatic pallet exchange device moves the pallet work so that the wireless recording medium passes through a predetermined data reading position by the reading device, and the reading device reads the work information from the wireless recording medium, and based on the work information read, issues a work instruction to the automatic pallet exchange device to store the pallet work being transported in the storage position indicated by the address assigned to the pallet work.

[0035] In the pallet work storage system of the present invention having the above-mentioned configuration, multiple pallet workpieces are stored on a storage shelf in the work storage section using multiple detachably attached shelves. The vertical spacing of the shelf mounting positions can be changed, and the longitudinal spacing of the pallet storage jigs on each shelf can also be changed. This allows the storage arrangement pattern within the storage shelf to be changed according to the height and width dimensions of the workpieces to be processed. Note that the height dimension of the target workpieces, which determines the vertical spacing of the shelf boards, must take into account the height of the pallet to which the workpieces are fixed, so it is essentially the height of the pallet workpieces.

[0036] In general, machining center machine tools have an exterior cover that functions as a splash guard around the machining area, including the automatic tool changer, and this exterior cover forms the outer wall.Usually, a control panel for a computer numerically controlled (hereinafter also referred to as a CNC device) is installed on the side of the exterior cover, and the continuous machining process of the workpiece is carried out automatically according to a predetermined NC machining program through numerical control by this CNC device.

[0037] Furthermore, a window is provided on this outer wall for supplying and unloading pallet workpieces to and from the processing section. This window is equipped with an opening / closing shutter that opens and closes in conjunction with the processing process. In other words, it is closed during processing, and is opened after processing is completed and before the start of the next processing step to supply and unload pallet workpieces.

[0038] On the other hand, the work storage compartment in the present invention is also surrounded by a similar exterior cover to form an outer wall. This work storage compartment needs to be adjacent to the machining compartment so that pallet workpieces can be moved in and out of the machining compartment of the machine tool using an automatic pallet changer. In other words, when it is installed next to the machine tool, a window needs to be provided in the outer wall of the work storage compartment that contacts the window on the machining compartment side so that it can communicate with the window on the machining compartment side.

[0039] The pallet workpiece storage system of the present invention can store multiple workpieces and is suitable for use with machine tools that perform continuous machining processes in mass production. Therefore, its configuration can be designed in advance so that when installed next to the target machine tool, the window on the workpiece storage compartment can communicate with the window on the machining compartment of the machine tool.

[0040] In a pallet workpiece storage system with the above configuration, multiple workpieces to be processed are stored in a storage shelf during a preparation process immediately before the execution of consecutive machining processes in a machine tool. In this storage process, each workpiece is first fixed to a corresponding pallet on a setup table to form an integrated pallet workpiece. Each pallet workpiece is transported sequentially from the setup table to the storage shelf by an automatic pallet changer, and stored so as to fill each storage position.

[0041] In the present invention, a wireless recording medium for storing various data is attached to each pallet on which workpieces are integrated on the setup table. This wireless recording medium stores workpiece information including the type of workpiece to be fixed and a storage arrangement pattern selected and registered in accordance with the size dimensions of that type of workpiece.

[0042] In the present invention, the storage arrangement pattern is determined by the number of rows and columns in the storage shelf, determined by the vertical spacing between storage units and the horizontal spacing between storage units. Therefore, multiple storage arrangement patterns are prepared in advance for different types of workpieces, with different vertical and horizontal spacing between storage units corresponding to the different sizes of the workpieces. In each storage arrangement pattern, an address is assigned to each storage position that makes up the pattern.

[0043] Therefore, a storage arrangement pattern suited to the type of workpiece to be fixed is selected and stored as workpiece information in each wireless recording medium of each pallet, and the address of each storage position in that storage arrangement pattern is assigned to each pallet. That is, the address assigned to each pallet is also assigned to the workpiece fixed to that pallet, and that address, along with the storage arrangement pattern, is stored as workpiece information in the wireless recording medium. Each address is linked to a coordinate position in the coordinate system of the automatic pallet changer for positioning the hand unit. Therefore, each pallet workpiece has an address that indicates a unique storage position. The automatic pallet changer can then determine the actual storage position of the pallet workpiece to be transported in the storage shelf based on that address.

[0044] In the present invention, each time a pallet workpiece is transported from the setup table to the storage shelf, the automatic pallet exchanger controlled by the storage control device causes the wireless recording medium of each pallet to pass through a predetermined data read position for the reading device immediately after the start of transport. Then, at this data read position, workpiece information for the pallet workpiece being transported is read from the wireless recording medium. The location of the reading device is not particularly limited, as long as it is located within the work storage section and does not interfere with the transport of the pallet workpiece between the storage shelf and the processing section by the automatic pallet workpiece exchanger. It is also desirable for the reading device to be located in a position that allows the pallet workpiece to pass through the data read position as efficiently as possible without significantly deviating from the transport path from the setup table to the storage shelf.

[0045] The workpiece information read by the reading device contains a storage arrangement pattern selected and registered according to the type of workpiece, and an address indicating a unique storage position assigned to the pallet workpiece in that storage arrangement pattern, which is then read by the storage control device. The storage control device then causes the automatic pallet exchanger to store the pallet workpiece in the storage position corresponding to the address in the read storage arrangement pattern. This prevents the automatic pallet exchanger from carrying out a storage process using an incorrect storage arrangement pattern without the changed storage arrangement pattern in the actual storage shelf being reflected in the automatic pallet exchanger. The automatic pallet exchanger then correctly stores the pallet workpieces corresponding to each of the storage positions in the storage shelf based on each address in the correctly changed storage arrangement pattern, preventing incorrect storage positions or duplication.

[0046] As described above, in the present invention, even if the type of workpiece to be used in a new consecutive machining process is changed from the workpiece used in the previous machining process, the storage arrangement pattern on the storage shelf is also changed according to the size of the new type of workpiece. Furthermore, since the storage of the pallet workpieces on the storage shelf is performed after reading out the storage arrangement pattern and the unique address assigned to that pallet workpiece in that storage arrangement pattern, there is no risk of delays in the transport process due to incorrect storage positions midway, and the preparation process for storing the workpieces can be completed efficiently.

[0047] Furthermore, in continuous machining processes using automatically operated machine tools according to a predetermined NC machining program, the automatic pallet exchanger is also driven and controlled by a transport program incorporated into the NC machining program. That is, in the order of the addresses of each storage position in the storage layout pattern set in the transport program, pallet workpieces are taken out of the storage shelf and supplied to a predetermined position in the machining area, and after machining, the pallet workpieces are transported out of the machining area and returned to the storage position at the predetermined address in the storage shelf. This supply and removal of pallet workpieces is performed continuously at a timing linked to the machining process for each workpiece, but because the pallet workpiece storage system of the present invention stores pallet workpieces correctly in all storage positions in advance, smooth transport and machining processes are completed for all workpieces.

[0048] In addition, in this invention, shelves can be directly inserted and removed from the storage shelf from the outside through an access door on the rear wall of the storage shelf. Because the shelves are also removable, the vertical mounting position of each shelf can be easily changed whenever the storage arrangement is changed. In this case, the number of shelves mounted on the storage shelf may need to be changed in accordance with changes in the vertical spacing, but this number can be easily adjusted. Furthermore, even if there are only a few extra shelves after the change, it will only take up a small amount of storage space.

[0049] Furthermore, in the present invention, the storage position of each shelf in the longitudinal direction can be changed by simply removing the pallet storage jig already fixed to the same shelf and re-fixing the pallet storage jig corresponding to the new pallet work at the spacing position set for it. This pallet storage jig position change can also be performed directly on each shelf inside the storage shelf through the opening. Of course, this change can also be performed on a shelf that has been removed through the opening, so an efficient work procedure can be selected and performed as needed.

[0050] Furthermore, because the shelf's longitudinal storage position can be changed by changing the pallet storage jig attached to the same shelf and its fixed position, there is no need to prepare multiple shelf groups with different fixed position intervals for the pallet storage jig. Furthermore, there is no need to replace the entire shelf group when changing the work type. This saves space and effort for storing a large number of unused shelf groups.

[0051] In addition, when returning each pallet workpiece from the processing section to the storage shelf after processing by the automatic pallet changer in the continuous processing process, it is possible to set the transport program so that the wireless storage medium is routed to the data read position by the reading device. In this case, the address assigned to the pallet workpiece to be returned can be read again before it is returned to the specified storage position.

[0052] In this way, even when returning the pallet workpieces to the storage location indicated by the read address, the automatic pallet changer can correctly store the pallet workpieces in the storage location indicated by the read address. Therefore, by reading the address during the return storage, delays in the transport process due to an incorrect return location can be avoided, which contributes to the overall efficiency of the continuous processing process after the workpiece type is changed.

[0053] Furthermore, in addition to the storage arrangement pattern, the workpiece information can also include the NC machining program number set for the type of workpiece and offset information for the workpiece and tool. In this case, by reading this information on the machine tool just before starting to process the workpiece, it is possible to confirm whether it matches the NC machining program and offset set for the workpiece in advance, and whether the correct storage arrangement pattern is reflected in the transfer program. This ensures that there is no risk of machining the wrong type of workpiece, for example. As a result, there is no risk of unnecessary work stopping the continuous machining process, such as removing and replacing the incorrect workpiece, and the entire process can be completed smoothly.

[0054] Furthermore, the wireless recording medium attached to the pallet used in the present invention, the reading device that reads information from this wireless recording medium, and the storage control device that controls the automatic pallet exchange device based on the read information can be any existing system that is easily available.

[0055] For example, a so-called RFID (Radio Frequency Identification) system is a suitable example. An RFID system is an individual recognition system that reads and writes information from an ID tag in a contactless manner via radio or electromagnetic waves. In this case, the ID tag serving as a wireless recording medium (data carrier) is an RF tag, and data such as information about various objects and work instructions is stored in it. Therefore, when an RFID system is employed in the present invention, an RF tag is attached to the pallet, and a read / write head that wirelessly communicates with the RF tag to read and rewrite data is fixed to, for example, an automatic pallet exchanger in the work storage compartment or in its vicinity.

[0056] Furthermore, the storage control device of the present invention may be an ID controller or the like that instructs automatic work based on information from an RF tag read via a read / write head. This ID controller may be, for example, a programmable logic controller (PLC) or another personal computer. It may also be connected to a higher-level device. Therefore, the storage control device of the present invention may be configured to be installed in a workpiece storage section independent of the machine tool, or may be configured to be linked to the control unit of a CNC device. The higher-level device may also be the control unit of a CNC device.

[0057] Furthermore, the storage shelf of the present invention and the configuration for mounting shelves therein in a manner that allows the shelves to be adjusted in the vertical direction are not particularly limited, but a configuration that minimizes the space occupied by the shelf, allows for efficient storage, and allows for easy installation of openings and access doors is desirable. Therefore, the storage shelf has a generally housing-like shape and includes a pair of opposing support walls, and the pair of support walls are provided with support members at a plurality of predetermined equally spaced positions in the vertical direction on the opposing wall surfaces, detachably supporting both ends of the generally rectangular shelf members. In this configuration, by appropriately selecting the spacing of the support members, the mounting positions of the multiple shelves in the vertical direction can be adjusted according to the height of the target workpieces.

[0058] The support parts that support both ends of the shelf boards can be configured in a variety of ways as long as they can removably hold each shelf board in its horizontal position. However, it is desirable that the support parts themselves be easily formed and that the shelf boards can be easily attached and detached to and from the support parts.

[0059] For example, a configuration in which slits are provided at the same height on the opposing inner wall surfaces of a pair of support walls, and protrusions that are removably inserted into the pair of slits extend along both short sides of the shelf board. Another simple configuration is one in which grooves are formed on the opposing inner wall surfaces into which the ends of both short sides of the shelf board are supported by sliding them horizontally.

[0060] In either case, it is desirable to screw both ends of the shelf board to the inner wall surface of the support wall while the shelf board is supported to keep the shelf board in a more stable state. In this case, for example, a side flange portion can be provided on the short side of each shelf board, and screw holes can be drilled at the positions where these flange portions overlap with the inner wall surface of the support wall that abuts on the shelf board when it is supported.

[0061] Furthermore, when the automatic pallet changer attempts to store each pallet workpiece in a target storage position within the storage shelf, for example, if the adjacent storage positions are very close, it is possible that the automatic pallet changer may attempt to store the pallet workpiece in the wrong storage position. In this case, there is a risk of collision with pallet workpieces already stored in that storage position. Therefore, it is preferable to provide a means for checking whether pallet workpieces are already stored in the target storage position just before finally storing the pallet workpieces.

[0062] Therefore, in the pallet work storage system of the present invention, the pallet storage jig is equipped with a detector that outputs a detection (ON) signal when the pallet is seated in the pallet receiving portion, and the storage control device determines, based on the signal from the detector, whether another pallet work is stored in the pallet storage jig at the target storage position where the automatic pallet exchange device is attempting to store the pallet work.

[0063] Therefore, just before storing the pallet workpieces in a specified storage position on the storage shelf, the storage control device can check the signal from the detector of the pallet storage jig at that storage position, and if there is no ON signal from the detector, it can determine that no other pallet workpieces are present there and that there is no problem with the storage position.In this case, the storage control device can have the automatic pallet exchanger complete the storage operation.

[0064] Furthermore, if an ON signal is output from the detector of the pallet storage jig at the storage position, it means that another pallet workpiece has already been stored in that pallet storage jig, and the storage control device determines that the storage position is not the storage destination for the pallet workpiece currently being stored.The address indicating the storage position of the pallet workpiece can then be confirmed again, and the automatic pallet exchange device can be made to transport it to the correct storage position.As a result, incorrect storage positions are avoided.

[0065] The pallet and pallet storage jig configurations of the present invention can be the same as those of the conventional pallet and pallet storage jig. This allows existing pallets and pallet storage jigs to be used without the need to manufacture new, special pallets and pallet storage jigs. Therefore, it is sufficient to have a structure on the shelf side that allows the pallet storage jig to be fixed in a replaceable and repositionable manner.

[0066] The detector of the present invention is preferably one that is simpler, smaller, and lower cost, and although mechanical switches such as limit switches and microswitches can be used, it is more preferable to use a contact-type position detection switch. For example, a contact-type detection switch that operates without mechanical contact with a moving part, such as a proximity switch, can detect the approach or presence of an object without directly contacting the object, and since it does not require contact with the object, it is less likely to be damaged and has a longer lifespan than a mechanical switch, making it preferable.

[0067] Furthermore, when a detector such as the proximity switch is installed on a pallet storage jig, it is sufficient to install it in an existing configuration by creating an installation space at a position where it can detect a part of the pallet. In this case, it is simple to detect the pull bolt on the pallet. That is, the pallet has a roughly disk-shaped table on whose upper surface the workpiece is fixed and a pull bolt protruding downward from the center of the underside of the table. The pallet storage jig has a cylindrical pallet holder with a dish-shaped seat at its upper end into which the lower part of the table fits. The pallet holder has a groove formed in the center of the seat that receives the pull bolt when the table is seated, and a notch in the cylindrical side and the side of the groove that communicate with each other. The detector is inserted into the notch to detect the pull bolt received in the groove.

[0068]

[0013] Note that the shelf plate in the present invention is one to which the pallet storage jig equipped with the above-mentioned detector is detachably fixed, and it is desirable that the interval between the fixed positions be easily adjustable. Specifically, the pallet storage jig has a fixing plate portion having a width corresponding to the maximum horizontal width of the workpieces to be stored, which is detachably fixed to the shelf plate and from which the pallet receiving portion protrudes on its upper surface, the pallet receiving portion having a convex portion at the center of its bottom surface that penetrates the fixing plate portion and protrudes downward, the shelf plate has fixing portions of the pallet storage jig provided at a plurality of predetermined different equally spaced positions, and the fixing portions have through holes on their upper surface through which the convex portions of the pallet receiving portion can be inserted and removed, and screw holes at a plurality of locations around each through hole for screwing the bottom surface of the fixing plate portion with the convex portions inserted into the through holes.

[0069] With the shelf configuration described above, the preparation process involves first selecting a pallet storage jig with a fixing plate whose width corresponds to the maximum horizontal width of the target workpieces. Then, the pallet storage jig is fixed to each shelf by selecting through-holes formed at longitudinal intervals on the shelf that correspond to the storage arrangement pattern suited to the target workpieces. The protrusions projecting downward from the center of the bottom surface of the packet receiving section are inserted into the selected through-holes, and the bottom surface of the fixing plate is screwed into the screw holes around the through-holes, thereby fixing the pallet storage jig to the shelf at the desired fixed interval.

[0070] The present invention is intended for continuous machining of multiple workpieces, and the storage arrangement pattern can be changed to accommodate different workpiece sizes. Therefore, different types of fixing plate widths are prepared so that a pallet storage jig with a fixing plate width corresponding to the maximum width of the workpieces can be selected. However, the range of workpiece sizes that can be changed is within the range of sizes that can be stored on the storage shelf, so there is no need to set a very large range.

[0071] In practice, two types of pallets, one small and one large, are sufficient within the range that can be stored on the storage shelf. Of course, it is also possible to prepare pallet storage jigs with more specific variations in the width of the fixing plate part. Furthermore, it is efficient to use pallets of the same shape that can accommodate all work sizes expected within the range of sizes that can be stored on the storage shelf. In this case, the pallet receiving parts that are combined with fixing plate parts of different widths can be one type of common size.

[0072] Therefore, the actual change of the storage arrangement pattern applied to the target workpieces can be completed simply by selecting a set of support parts formed on the opposing wall surfaces of a pair of support columns of the storage shelf that matches the vertical spacing position that will form the storage arrangement pattern, and supporting the required number of shelf boards with pallet storage jigs fixed at the desired fixed spacing as described above between the selected support parts through openings provided in the rear wall of the storage shelf.In addition, in the present invention, it is also possible to support all the required shelf boards on the specified support parts, and then fix the pallet storage jigs to each shelf board through the openings.

[0073] The detector of the present invention is preferably one that is simpler, smaller, and lower cost, and although mechanical switches such as limit switches and microswitches can be used, it is more preferable to use a contact-type position detection switch. For example, a contact-type detection switch that operates without mechanical contact with a moving part, such as a proximity switch, can detect the approach or presence of an object without directly contacting the object, and since it does not require contact with the object, it is less likely to be damaged and has a longer lifespan than a mechanical switch, making it preferable.

[0074] The detector for the pallet and pallet receiver configured as above can be configured by inserting a proximity switch into the notch in the groove and positioning it near the surface of the pull bolt if one is present. When the proximity switch detects the presence of a pull bolt, a detection signal is sent to the storage control device, which determines whether the pull bolt, i.e., the pallet work, is present.

[0075] Therefore, immediately after starting storage and transport, the storage control device reads the work information stored in the wireless storage medium of the target pallet work using a readout device, and then has the automatic pallet exchanger transport the pallet work to the storage position of the read address, but when the hand unit reaches a position directly in front of that storage position, it is set up to determine whether or not a pallet work is present by checking whether or not there is a detection signal from the proximity switch (detector).If there is no detection signal, the storage control device determines that there is no pull bolt, i.e., no other pallet work, present in that storage position and that the storage position is correct, and then has the automatic pallet exchanger complete the final storage operation. [Effects of the Invention]

[0076] As described above, according to the pallet work storage system of the present invention, in the preparation process before the execution of the continuous machining process, the storage arrangement pattern of the storage shelf can be easily changed in accordance with changes in the size of the target workpieces, and since the changed storage arrangement pattern and the addresses indicating the storage positions assigned to the pallet workpiece among the storage positions in the storage arrangement pattern are stored in a wireless recording medium attached to the pallet on which the workpieces are fixed, the effect is that, regardless of the storage arrangement pattern, the panel workpiece can be stored correctly in the assigned storage position after reading out the storage arrangement pattern and address. Therefore, according to the present invention, in the actual continuous machining process, all of the pallet workpieces that have already been stored in the correct storage positions in the storage shelf are each supplied to the machining section without error or delay and returned to the correct storage position after machining, so that each transport process of all of the pallet workpieces is always carried out correctly and smoothly, thereby further improving the efficiency of the entire machining process. [Brief explanation of the drawings]

[0077] [Figure 1] 1 is a schematic perspective view of the overall configuration of a machining center equipped with a pallet workpiece storage system according to an embodiment of the present invention, viewed from the storage shelf side with the access door omitted. FIG. [Figure 2] 2 is a schematic plan view showing the inside of a workpiece storage section and a machining section of the machining center of FIG. 1, omitting the automatic pallet changer. FIG. [Figure 3] 3 is a plan view of the workpiece storage section of FIG. 2 viewed from above with an automatic pallet changer disposed therein. [Figure 4] FIG. 4 is a perspective view showing a schematic configuration of the automatic pallet exchanger of FIG. 3. [Figure 5] 5 is a side view showing the configuration of a read / write head provided in the automatic pallet exchanger of FIG. 4 and a pallet being transported by a hand unit to a data reading position by the read / write head. [Figure 6] 6 is a schematic plan view of the read / write head and pallet of FIG. 5 as viewed from above. [Figure 7] 2 is a perspective view showing a schematic configuration of a shelf board attached to the storage shelf of FIG. 1. FIG. [Figure 8] 8 is a perspective view showing a schematic configuration of a pallet storage jig fixed to the shelf board of FIG. 7. [Figure 9] 9 is a plan view showing a state in which the pallet storage jig of FIG. 8 is fixed to the shelf board of FIG. 7. FIG. [Figure 10] 10 is a cross-sectional view taken along line AA of the pallet storage jig of FIG. 9 fixed to a shelf board. [Figure 11] 10 is a plan view showing a state in which a pallet storage jig having a fixing plate portion with a width different from that of FIG. 9 is fixed to the shelf board of FIG. 7. [Figure 12] FIG. 2 is a schematic diagram showing a storage arrangement pattern of five rows and four columns in the storage shelf of FIG. 1, and is a rear view omitting the outer wall including the access door. [Figure 13] FIG. 2 is a schematic diagram showing a storage arrangement pattern of five rows and three columns in the storage shelf of FIG. 1, and is a rear view omitting the outer wall including the access door. [Figure 14] FIG. 2 is a schematic diagram showing a storage arrangement pattern of four rows and three columns in the storage shelf of FIG. 1, and is a rear view omitting the outer wall including the access door. [Figure 15] FIG. 2 is a schematic diagram showing a storage arrangement pattern of three columns and three rows in the storage shelf of FIG. 1, and is a rear view omitting the outer wall including the access door. [Figure 16] FIG. 2 is a schematic diagram showing a storage arrangement pattern in which different vertical spacings and different horizontal spacings are mixed in the storage shelf of FIG. 1, and is a rear view omitting the outer wall including the access door. [Figure 17] FIG. 2 is a block diagram showing the correlation between the main parts of the pallet work storage system of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0078] An embodiment of the pallet work storage system according to the present invention will be described below with reference to Figures 1 to 3, in which the system is attached to a machine tool and forms part of a machining center. Figure 1 is a schematic perspective view of the overall configuration of a machining center 1 equipped with a pallet work storage system 2 according to the embodiment, viewed from the storage shelf 11 side with the access door omitted. Figure 2 is a schematic plan view showing the interior of the work storage compartment 10 and machining compartment 40 with the automatic pallet changer omitted. Figure 3 is a plan view of the work storage compartment 10 of Figure 2, viewed from above with the automatic pallet changer 30 installed.

[0079] The pallet workpiece storage system 2 according to this embodiment is installed alongside an existing machine tool 3 that is numerically controlled by a computer numerical control device (CNC device) 4, and the entire machine tool 3, including a machining section 40 equipped with an automatic tool changer 41, is enclosed by an exterior cover 5. An operation panel CP of the CNC device 4 is installed on the side of this exterior cover 5.

[0080] The pallet workpiece storage system 2 according to this embodiment is mainly configured in a workpiece storage section 10 adjacent to a machining section 40, and this workpiece storage section 10 is also surrounded by an exterior cover 6. By connecting this exterior cover 6 to an exterior cover 5 that surrounds the machining section 40, the workpiece storage section 10 and the machine tool 3 are essentially connected integrally.

[0081] The workpiece storage section 10 is also equipped with a storage shelf 11 that stores a plurality of pallet workpieces PW, and an automatic pallet changer 30 that transports the pallet workpieces PW between the storage shelf 11 and the machining section 40. The control section 50 of the CNC device 4 automatically operates the machine tool 3 in conjunction with the automatic tool changer 41 to execute successive machining processes based on tool information T and various NC machining programs 52 stored in a memory section 51, and a transport program 53 is incorporated into the NC machining program 52. The automatic pallet changer 30 is driven and controlled in accordance with the transport program 53, so that the pallet workpieces PW are exchanged at appropriate times for the machining table 42 in the machining section 40 in conjunction with the start and end of each machining process.

[0082] 4, this automatic pallet changer 30 transports pallet workpieces PW between the storage shelf 11 and the machining section 40 by a robot arm 36. For this reason, in the area where the outer wall consisting of the exterior cover 5 surrounding the machining section 40 and the outer wall consisting of the exterior cover 6 surrounding the workpiece storage section 10 meet, windows (7, 43) are formed that communicate with each other so that the robot arm 36, which grasps the pallet workpiece PW with a hand portion 37 at the tip, can move the pallet workpiece PW in and out between the two sections (10, 40). The window 43 of the machining section 40 is provided with an opening / closing shutter 44 that closes the window 43 during the machining process.

[0083] Furthermore, in the workpiece storage compartment 10 of this embodiment, a setup table 18 is provided on one end thereof, and a storage shelf 11 having a generally cabinet shape is provided in an area facing the machining compartment 40 with the automatic pallet changer 30 in between. The setup table 18 is formed as a generally cylindrical compartment that communicates with the workpiece storage compartment 10, and is surrounded by a semi-cylindrical door 19 that can be opened and closed. This door 19 is opened when the automatic pallet changer 30 is stopped.

[0084] As a preparation step immediately before the execution of a continuous machining process by the machine tool 3, predetermined workpieces W are stored one by one in the storage shelf 11 from outside via the setup table 18. At that time, each workpiece W is fixed to a pallet P corresponding to its type and size on the setup table 18 by bolts or the like. After the door 19 is closed, the workpiece W is stored in a predetermined storage position in the storage shelf 11 by the robot arm 36 of the automatic pallet changer 30 in the form of a pallet workpiece PW fixed integrally to the pallet P.

[0085] In the automatic pallet changer 30 of this embodiment, its base 31 is installed on the floor surface of the workpiece storage section 10, and a vertically extending column 33 is erected on the base 31 via a column support base 32. In addition, a base guide rail 31G is provided on the base 31, and is provided parallel to the longitudinal sides of the shelves 14 of the storage shelf 11. The rotational motion of the horizontal drive motor M1 is transmitted as linear motion via a ball screw mechanism to the column support base 32, which is slidably fitted into the base guide rail 31G, so that the column 33 can move horizontally left and right together with the column support base 32 along the base guide rail 31G.

[0086] Additionally, an upper guide rail 34G is provided above the workpiece storage compartment 10, extending parallel to the long side of the shelf 14. The upper end of a support column 33 is supported by an upper support portion 34 slidably fitted to the upper guide rail 34G. Therefore, the support column 33 is capable of stable horizontal movement with its upper and lower ends supported between the upper guide rail 34G and the base guide rail 31G. A vertically extending lift guide rail 33G is formed on the support column 33. A robot arm 36, which holds a pallet P with a hand portion 37 at its tip, is connected to the support column 33 via an arm support portion 35 slidably fitted to the lift guide rail 33G. The rotational motion of the lift drive motor M2 is transmitted as vertical linear motion to the arm support portion 35 via a ball screw mechanism, causing the arm support portion 35 to move vertically along the lift guide rail 33G, thereby lifting and lowering the robot arm 36.

[0087] The robot arm 36 is supported slidably along slide guides 35S of the arm support section 35. The rotational motion of the extension motor M3 is transmitted as linear motion to the robot arm 36 via gears, causing the robot arm 36 to extend and retract in the front-to-rear direction perpendicular to the support column 33 along the slide guides 35S of the arm support section 35. The support column 33 is rotatably supported about its vertical central axis by the upper support section 34 and the support column base 32, and the rotational motion of the rotation drive motor M4 is transmitted to the support column 33 to rotate the arm support section 35 and the robot arm 36. As a result, the arm support section 35 and the robot arm 36 supported by the support column 33 are rotated about the vertical central axis of the support column 33.

[0088] In the automatic pallet changer 30 having the above configuration, the drive motors are driven and controlled so that the robot arm 36 moves up and down, moves left and right horizontally, turns, and moves back and forth along a predetermined course. In the preparation process, the robot arm 36 moves so as to sequentially store the pallet workpieces PW from the setup table 18 to the desired storage positions in the storage shelf 11. In the continuous processing process, the robot arm 36 supplies the pallet workpieces PW stored in each storage position in the storage shelf 11 to the processing table 42 in the processing section 40 in a predetermined order, and moves so as to return the processed pallet workpieces PW from the processing table 42 to the desired storage position in the storage shelf 11.

[0089] The pallet P in this embodiment has the same basic configuration as a conventional pallet. Specifically, as shown in Fig. 5, it is primarily composed of a disk-shaped table portion Pt, to whose upper surface the workpiece W is fixed, and a pull bolt Pb protruding downward from the center of the back surface of the table portion Pt. The table portion Pt is composed of an upper portion te with a relatively large outer diameter and a lower portion tr with a relatively small outer diameter, and when this lower portion tr is seated on the seating portion of the pallet storage jig 20 described below, a releasable storage state of the pallet workpiece PW is achieved.

[0090] In this embodiment, the hand unit 37 of the automatic pallet changer 30 is in the shape of a two-pronged fork, and engagement portions tg are formed on the outer circumferential surface of the upper part te of the table part Pt, with the tips of the two forks being inserted from both sides below the upper part te to engage with it. By engaging with these engagement portions tg, the hand unit 37 grasps the pallet P so that it can be lifted.

[0091] The storage shelf 11 in this embodiment has a pair of support walls 12 installed opposite each other on both sides, between which a plurality of rectangular shelf boards 14 are supported in a horizontal manner in the longitudinal direction. A plurality of pallet workpieces PW are stored in the storage shelf 11 by storing a plurality of pieces of pallet workpieces PW in the longitudinal direction of these shelf boards 14. The storage shelf 11 in this embodiment has an opening 8 in the outer wall on the rear side, and is fitted with double-door access doors (9a, 9b) that can be opened and closed to cover this opening 8.

[0092] As shown in Figure 1, opening 8 with access doors (9a, 9b) (not shown) open exposes the entire storage area on the back side of storage shelf 11. Normally, after processing of all workpieces W on storage shelf 11 is completed, each pallet workpiece PW is transported to setup table 18 by automatic pallet changer 30, and doors 19 are opened to remove and collect them one by one to the outside, but by opening these access doors (9a, 9b), all of the processed pallet workpieces PW can be removed in one go from opening 8 in a short time.

[0093] Furthermore, in this embodiment, each shelf board 14 is detachable from the pair of support walls 12, and its mounting position in the vertical direction can be changed, so that when the type of workpiece W to be processed is changed and its height size is changed, the vertical spacing of the shelf boards 14 can be adapted to the height of the workpiece W. The shelf boards 14 can be easily attached and detached to and from the pair of support walls 12, and their mounting positions can also be changed, via this opening 8. The access doors (9a, 9b) are opened by pressing a door open button B located in the end region of the rear outer wall, but for safety reasons, they are set so that they will not open even if the door open button B is pressed while the automatic pallet changer 30 is operating.

[0094] In this embodiment, slit holes 13 are used as support parts for horizontally supporting each shelf board 14 between a pair of support walls 12. Pairs of two slit holes 13 are formed in the horizontal direction on the opposing inner wall surfaces of the pair of support walls 12 at the same height position on the inner wall surfaces. In addition, as shown in Figure 6, each shelf board 14 has two extending protrusions 16 on both short sides that are removably inserted into the corresponding pairs of slit holes 13. These slit holes 13 and protrusions 16 make it easy to attach and detach the shelf board 14 to and from the pair of support walls 12.

[0095] Furthermore, as shown in the perspective view of FIG. 7 , the shelf 14 in this embodiment has a double-layered structure in which an upper plate 14a and a lower plate 14b are stacked together. The protruding piece 16 is provided as an extension of the upper plate 14a. The lower plate 14b has a fringe portion that extends along the entire periphery. The fringe portions 17 on the shorter sides of the shelf 14 abut against the inner wall surfaces of the support walls 12 when the protruding piece portions 16 are inserted into the corresponding slit holes 13 and the shelf 14 is supported horizontally between the pair of support walls 12. Therefore, in this embodiment, screw holes (N1, n1) are provided in the abutting fringe portions 17 of the shelf 14 and the inner wall surfaces of the support walls 12 so that the two can be screwed together. This screw fastening more reliably supports the shelf 14 between the pair of support walls 12.

[0096] The support portions for the shelves 14, which are formed by the slit holes 13, are provided at a plurality of different equally spaced positions so that the mounting intervals of the shelves 14 can be changed in the vertical direction of the pair of support walls 12. In this embodiment, as shown in Fig. 1, pairs of slit holes 13 serving as support portions are formed at height positions (Ah, Bh, Ch, Dh, Eh, Fh, Gh, Hh, Ih, Jh) that allow the vertical arrangement of the shelves 14 in the storage shelf 11 to be mutually changed into three different shelf arrangement patterns: five shelves in five rows, four shelves in four rows, and three shelves in three rows.

[0097] Among these height positions, if groups of pairs of slit holes 13 at five equally spaced positions (Ah, Dh, Fh, Ih, Jh) are selected and shelves 14 are attached to a pair of support walls 12, respectively, the shelf arrangement pattern of the storage shelf 11 will be five tiers with the smallest vertical spacing of the three types, as shown in Figures 12 and 13. If another group of pairs of slit holes 13 at four equally spaced positions (Bh, Eh, Hh, Jh) is selected and shelves 14 are attached to each, then four tiers will be created with a larger vertical spacing than the five tiers mentioned above, as shown in Figure 14. If yet another group of pairs of slit holes 13 at three equally spaced positions (Ch, Gh, Jh) is selected and shelves 14 are attached to each, then the shelf arrangement pattern will be three tiers with the largest vertical spacing of the three types, as shown in Figure 15.

[0098] Therefore, even if the type of workpiece W to be processed is changed and the height of the pallet workpiece PW to be stored is changed, the shelf arrangement pattern can be easily changed to one with vertical spacing suitable for the changed height of the pallet workpiece PW by simply changing the group of pairs of slit holes 13 at the height position that supports the shelf boards 14 to an appropriate one and reattaching the shelf boards 14.

[0099] Furthermore, in this embodiment, pallet storage jigs 20 for storing pallets P with workpieces W fixed thereto are removably fixed at predetermined intervals along the longitudinal direction of the shelf board 14 on the upper surface of the table portion Pt. Therefore, pallet workpieces PW are stored on the shelf board 14 via the pallet storage jigs 20. Essentially, through holes 15 that serve as fixing portions for the pallet storage jig 20 are formed at predetermined positions in the upper plate 14a of the shelf board 14, and the pallet storage jig 20 is attached via the through holes 15.

[0100] Fig. 8 is a schematic perspective view showing the configuration of the pallet storage jig 20, and Fig. 9 is a plan view showing the pallet storage jig 20 fixed to the shelf board 14 of Fig. 7. Fig. 10 is a cross-sectional view taken along line AA of the pallet storage jig 20 of Fig. 9 fixed to the shelf board 14. As shown in Figs. 8 and 10, the pallet storage jig 20 includes a fixed plate portion 21 that is detachably fixed to the upper plate 14a of the shelf board 14, and a cylindrical pallet receiving portion 22 that protrudes from the upper surface of the fixed plate portion 21. A dish-shaped seating portion 23 is provided at the top of the pallet receiving portion 22 into which the lower part tr of the table portion Pt of the pallet P fits and is seated. A groove 24 is formed in the center of the seating portion 23 in the diameter direction, and the groove 24 receives the pull bolt Pb when the lower part tr of the pallet P is seated thereon.

[0101] Furthermore, a protrusion 26 that penetrates the fixing plate 21 and protrudes downward is provided in the center of the bottom surface of the pallet receiving portion 22. With this protrusion 26 inserted into the through-hole 15 formed in the upper plate 14a of the shelf board 14, the bottom surface of the fixing plate 21 is screwed to the upper plate 14a using the screw holes N2 around the through-hole 15, thereby fixing the pallet storage jig 20 to the shelf board 14.

[0102] By providing these through holes 15 as fixing portions at a plurality of different predetermined equally spaced positions in the longitudinal direction of the shelf board 14, the fixing position of the pallet storage jig 20 can be changed to different intervals, that is, the storage position of the pallet workpiece PW can be changed to different intervals. As a result, when the type of workpiece W to be processed is changed and its maximum width is changed, the storage interval in the left-right horizontal direction of the shelf board 14 can be adapted to the maximum width of the workpiece W.

[0103] In this embodiment, as shown in Figure 7, through holes 15 serving as fixing portions for pallet storage jigs in the horizontal (longitudinal) direction of each shelf 14 are formed at five horizontal fixing positions (As, Bs, Cs, Ds, Es) on the upper plate 14a. These five horizontal fixing positions (As, Bs, Cs, Ds, Es) provide two different types of equally spaced positions: four equally spaced positions (As, Bs, Ds, Es) with relatively small horizontal spacing, and three equally spaced positions (As, Cs, Es) with relatively large horizontal spacing. This provides two different types of spacing between fixing positions for pallet storage jigs in the longitudinal direction of each shelf 14, and two selectable and changeable horizontal arrangement patterns for pallet workpieces.

[0104] That is, if four of the through holes 15 at equally spaced positions (As, Bs, Cs, Ds, Es) are selected from the five horizontal fixing positions (As, Bs, Cs, Ds, Es) and a pallet storage jig 20 is fixed to each of them, an arrangement of four pallet storage jigs 20 with smaller spacing between adjacent pallet storage jigs 20 will result in a four-row arrangement pattern of pallet workpieces W for the entire storage shelf 11 as shown in FIG. 12. Furthermore, if three of the through holes 15 at equally spaced positions (As, Cs, Es) are selected and a pallet storage jig 20' is fixed to each of them, an arrangement of three pallet storage jigs 20' with larger spacing between adjacent pallet storage jigs 20' will result in a three-row arrangement pattern of pallet workpieces W for the entire storage shelf 11 as shown in FIG. 13 to FIG. 15.

[0105] If the spacing between adjacent pallet storage jigs on each shelf 14 differs as described above, it is desirable to use a pallet storage jig with fixing plate parts whose widths vary according to the spacing. In other words, by changing the width of the fixing plate parts of the pallet storage jig to correspond to the maximum width of the target workpieces W, the gap between adjacent fixing plate parts can be reduced, resulting in a more stable storage state.

[0106] In this embodiment, when the four-row arrangement pattern with smaller spacing is selected, a pallet storage jig 20 having fixing members 21 with a smaller width that matches that spacing is used, and when the three-row arrangement pattern with larger spacing is selected, a pallet storage jig 20' having fixing members 21' with a larger width that matches that spacing is used. In this embodiment, both pallet storage jigs (20, 20') are combined with pallet receiving portions 22 of a common shape.

[0107] According to the configuration of the storage shelf 11 in this embodiment as described above, the storage position of the pallet work PW can be changed from a storage arrangement pattern of 3 rows and 3 columns, which has the maximum vertical and horizontal spacing and the minimum number of items that can be stored, to a storage arrangement pattern of 5 rows and 4 columns, which has the minimum vertical and horizontal spacing and the maximum number of items that can be stored, and each time the type of work W to be processed is changed, the storage arrangement pattern can be changed to one that is appropriate for the changed height and maximum width size of the work W.

[0108] The types of storage layout patterns that can be selected and changed in the storage shelf 11 are adapted to the types of workpieces that can be machined by the machine tool 3 and stored in the storage shelf 11, and can therefore be determined in advance according to the types of workpieces that are expected. Therefore, once the types of storage layout patterns are determined, it is sufficient to assign addresses to all storage positions in each storage layout pattern.

[0109] Furthermore, the storage arrangement pattern in the storage shelf 11 is not limited to the case where only one type of workpiece of the same shape is stored, as shown in Figures 12 to 15. For example, if two types of products, each differing by a decimal point, are formed from two types of workpieces of different sizes, these two types of workpieces can be stored simultaneously in separate areas in the storage shelf 11. In this case, in each area, the storage arrangement pattern will be such that the vertical storage intervals and the fixed horizontal intervals on each shelf 14 will be different depending on the size of the target workpieces.

[0110] 16, for example, a storage area for relatively small workpieces W is formed in the upper region of the storage shelf 11, and a storage area for relatively large workpieces W is formed in the lower region of the storage shelf 11. Specifically, in the upper region, an arrangement pattern is formed in which the shelf boards 14 are arranged in four rows with relatively small horizontal spacing by fixing pallet storage jigs 20 to four equally spaced positions (As, Bs, Ds, Es) of the through holes 15 in each upper plate 14a, and are attached in two tiers at the top two equally spaced height positions (Ah, Dh) with relatively small vertical horizontal spacing.

[0111] In the lower region, shelves 14 are arranged in three rows with relatively large horizontal spacing by fixing pallet storage jigs 20' equipped with relatively wide fixing plate portions 21' to three equally spaced positions (As, Cs, Es) of the through-holes 15 in each upper plate 14a. These shelves are arranged in two rows at two equally spaced height positions (Gh, Jh) with relatively large vertical spacing. Therefore, this storage arrangement pattern is a combination of two rows and four rows in the upper region and two rows and three rows in the lower region. Furthermore, the combination can be changed by changing the height positions and the fixing positions where the through-holes 15 are formed.

[0112] Meanwhile, in this embodiment, an RF tag m is attached as a wireless storage medium to each pallet P. The RF tag m stores, as work information, the type of work W fixed to the pallet P, a storage arrangement pattern selected based on the work size of that type, and a unique address indicating the storage position assigned to the pallet P among the storage positions in that storage arrangement pattern.

[0113] The automatic pallet exchange device 30 is provided with a read / write head 38 as a reading device that communicates wirelessly with the RF tag m to read and rewrite work information, and a storage control device 39 that reads the work information read by the read / write head 38 and controls the work transport by the automatic pallet exchange device 30, both fixed to the base 31.

[0114] In addition, during the storage and transport of each pallet work PW from the setup table 18 to the storage shelf 11 in the preparation process, the automatic pallet exchange device 30 is set to transport the pallet work PW so that the RF tag m is positioned at the data read position by the read / write head 38 immediately after each transport begins, based on work instructions from the storage control device 39.

[0115] In this embodiment, each pallet receiving portion 22 has cutouts (27, 25) that communicate with the cylindrical side surface and the side surface of the groove portion 24 therein. Proximity switches 28 are inserted into these cutouts (27, 25) from the outside. When the pull bolt Pb of the pallet P is inserted into the groove portion 24 with the lower portion tr of the table portion Pt seated on the seat portion 23, this proximity switch 28 outputs an ON (signal) as a detection signal indicating that the pallet workpiece PW is stored in the pallet storage jig 20.

[0116] The storage control device 39 is set up to detect the presence or absence of an ON signal from the proximity switch 28 of the pallet storage jig 20 at the target storage position where the pallet workpiece PW currently being held by the hand unit 37 of the automatic pallet changer 30 is to be stored, just before the jig is seated on the pallet receiving unit 20, and to determine, based on the detection result, whether the pallet storage jig 20 is empty or has already stored another pallet workpiece PW. In other words, the storage control device 39 detects the ON signal from the proximity switches (28-1, 28-2, 28-3, 28-4, 28-5, ... 28-n) at each address.

[0117] In addition, the storage control device 39 is set to instruct the automatic pallet exchange device 30 to transport the pallet work PW along a route that positions the RF tag m of the pallet P at a data reading position by the read / write head 38 immediately after the start of transporting each pallet work PW from the setup table 18 to the storage shelf 11.

[0118] The storage process in the storage shelf 11 by the pallet work storage system 2 of this embodiment equipped with the above configuration is performed as follows. First, as an initial setting, the workpieces W to be used in the subsequent continuous machining process are determined, and a storage arrangement pattern 54 for the storage shelf 11 corresponding to the size of the workpieces is selected and registered in the memory unit 51 in the control unit 50 of the CNC device 4. In addition, an NC machining program 52 for executing the continuous machining process in conjunction with the automatic tool changer 41 is set in the control unit 50 of the CNC device 4.

[0119] Furthermore, the control unit 50 incorporates into the NC machining program 52 a conveying program 53 in which the order of the pallet workpieces PW is set as the order of addresses indicating their storage positions for the process of supplying the pallet workpieces PW from the storage shelf 11 to the processing table 42 based on the determined storage arrangement pattern 54 and the process of returning the processed pallet workpieces PW from the processing table 42 to the storage shelf 11.

[0120] As an initial preparation step, first prepare the number of shelf boards 14 corresponding to the vertical spacing that constitutes the determined storage arrangement pattern 54 of the storage shelf 11. Then, for each shelf board 14, select fixing positions on each top plate 14a that correspond to the horizontal spacing that constitutes the determined storage arrangement pattern. Then, position a pallet storage jig 20 equipped with fixing plate portions 21 with a width that matches that spacing by inserting their respective protrusions 26 into each through-hole 15 at the selected fixing positions. Finally, screw the fixing plate portions 21 from the backside to the top plate 14a using screw holes N2 formed around each through-hole 15. This allows a predetermined number of pallet storage jigs 20 to be fixed to each shelf board 14 at predetermined intervals.

[0121] A predetermined number of shelf boards 14 with these pallet storage jigs 20 fixed thereto are installed horizontally inside the storage shelf 11 through the opening 8 formed by opening the access doors (9a, 9b) in the rear wall of the storage shelf 11. At this time, from among the pairs of slit holes 13 serving as support parts formed at a plurality of different equally spaced positions on the inner wall surfaces of the pair of support walls 12 facing each other, a group of pairs of slit holes 13 at height positions at intervals in the up and down vertical direction that constitute the previously determined storage arrangement pattern is selected.

[0122] By inserting the protruding pieces 16 extending from both short sides of each shelf 14 into each selected pair of slit holes 13, each shelf 14 is supported horizontally between the pair of support walls 12. In this supported state, fringe portions 17 rising from both short sides of the bottom plate 14b of each shelf 14 abut against the inner wall surfaces of the pair of support walls 12. Therefore, by screwing the fringe portions 17 into the screw holes N1 formed below each slit hole 13, the attachment of each shelf 14 to the storage shelf 11 becomes more secure.

[0123] By following the above procedure, the installation of all shelf boards 14 and the fixing of the pallet storage jigs 20 to each shelf board 14 are completed, and the determined storage arrangement pattern is completed within the storage shelf 11. When the access doors (9a, 9b) are closed with the storage arrangement pattern completed in this way, the automatic pallet changer 30 becomes operable, and the process of storing pallet workpieces PW into the storage shelf 11 can begin, as a preparation process.

[0124] First, since the address of each storage position in the determined storage arrangement pattern has also been determined, that address is assigned to each pallet workpiece PW to be stored in the storage shelf 11. Essentially, by assigning a dedicated address to the pallet P used here, a unique storage position is assigned to the pallet workpiece PW fixed to the pallet P. Each address number is linked to a coordinate position in the coordinate system of the automatic pallet exchange device 30 for positioning the hand unit 37, and the automatic pallet exchange device 30 can transport the pallet workpiece PW to the actual storage position indicated by that address based on this address.

[0125] Therefore, each RF tag m of the pallets P prepared in the required number for the continuous processing process to be carried out stores work information including a storage arrangement pattern selected to suit the type and size of the work W for that continuous processing process, and an address number indicating one of all storage positions in that storage arrangement pattern.

[0126] In the storage step of the preparation process, the door 19 is opened, the workpiece W is fixed to the pallet P on the setup table 18 and integrated into the pallet workpiece PW, and then the door 19 is closed. When the door 19 is closed, the automatic pallet changer 30 moves the robot arm 36 toward the setup table 18, grasps the pallet P with the hand unit 37, and removes the pallet workpiece W from the setup table 18. Immediately thereafter, the pallet workpiece PW is transported so that the RF tag m on the pallet P is positioned at a data read position by the read / write head 38.

[0127] When the work information is read from the RF tag m at this data reading position, the storage control device 39 continues transporting the pallet work PW to the storage position corresponding to the address assigned to the pallet work PW in the storage arrangement pattern set there, based on the work information read via the read / write head 38.

[0128] Then, when the pallet work PW reaches the front of the pallet storage jig 20 at the target storage position, if an on signal is not detected from the proximity switch 28 of that pallet storage jig 20, the storage control device 39 determines that the target storage position is vacant and there is no problem, and instructs the automatic pallet exchange device 30 to complete the storage of the pallet work PW at that storage position.

[0129] Here, for example, if the horizontal spacing between storage positions is dense and adjacent storage positions are very close to each other, it is possible that the automatic pallet changer 30 will transport the workpiece toward the pallet storage jig 20 next to the original target storage position. In this case, if another pallet workpiece PW has already been stored in the adjacent storage position, an ON signal will be output from the proximity switch 28 of the pallet storage jig 20 there.

[0130] Therefore, when the storage control device 39 detects an ON signal from the proximity switch 28, it determines that the storage position where the pallet workpiece PW is currently being stored is not vacant and is an incorrect storage position.The storage and transport of the pallet workpiece PW is then restarted.At this time, the RF tag m may be returned to the data read position by the read / write head 38, and the address included in the workpiece information may be read again.

[0131] If the pallet workpiece PW being held by the hand unit 37 has correctly reached the front of the pallet storage jig 20 at the target storage position, the automatic pallet changer 30 seats the pallet workpiece PW on the pallet receiver 22. Then, the hand unit 37 is pulled away from the seated pallet P, completing the storage of that pallet workpiece PW. The automatic pallet changer 30 then directs the hand unit 37 toward the setup table 18 to begin grasping and transporting the next pallet workpiece PW. This process is repeated for all pallet workpieces PW to be stored, and the storage process in the preparation process is completed when each workpiece PW is stored in the storage position of its assigned address.

[0132] As described above, in the pallet work storage system 2 of this embodiment, each time each pallet work PW is stored and transported to the storage shelf 11, the storage arrangement pattern and the address number of the storage position assigned to the pallet work PW in that storage arrangement pattern are first read based on the work information read from the RF tag m, so that the work is transported to the correct storage position without being transported to the wrong storage position. Then, by detecting whether or not there is an on signal from the proximity switch 28 just before storage, the correctness of the storage position is determined with high precision and adjusted, so that all pallet work PW are ultimately stored in the correct storage positions without any problems.

[0133] The continuous machining process is carried out after all pallet workpieces PW have been stored in the storage shelf 11. In this continuous machining process, since the storage of pallet workpieces PW in all storage positions within the storage shelf 11 has been completed correctly and without error, the supply of pallet workpieces PW from each storage position to the machining table 42 and the return transport of the pallet workpieces PW from the machining table 42 to each storage position after machining are carried out in order and without delay. This allows for a smooth and efficient continuous machining process. [Explanation of symbols]

[0134] 1: Machining center 2: Pallet work storage system 3: Machine tools 4:CNC equipment CP: Control panel 5,6: Exterior cover 7: Window 8: Opening 9a, 9b: Access doors B: Door open button 10: Work storage section 11: Storage shelf 12: Post wall 13: Slit hole N1, N2, n1: screw holes 14: Shelf 14a: Upper board 14b: Lower board 15:Through hole 16: Convex piece 17: Fringe section 18: Setup table 19: Door 20,20': Pallet storage jig 21,21': Fixed plate part 22: Pallet holder 23: Seating area 24: Groove 25: Notch 26: Convex 27: Notch 28, 28-1, 28-2, 28-3, 28-4, 28-5, 28-n: Proximity switch PW: Pallet Work W: Work P: Palette Pt: Table section te: upper part tr:bottom tg: Engagement part Pb: Pull bolt m:RF tag 30: Automatic pallet changer 31: Foundation 31G: Base guide rail 32: Post support stand 33: Post 33G: Lift guide rail 34: Upper support part 34G: Upper guide rail 35: Arm support 35S: Slide guide 36: Robot arm 37: Hand part M1, M2, M3, M4: Motors 38: Read / write head (reading device) 39: Storage control device 40: Processing area 41: Automatic tool changer 42: Processing table 43: Window 44: Open / close shutter 50: Control unit 51: Storage part T:Tool information 52: NC machining program 53:Transportation Program 54: Storage arrangement pattern

Claims

1. In a pallet work storage system attached to a machine tool that is numerically controlled by a computer numerical control device, a work storage section installed adjacent to the machining section of the machine tool; and a setup table provided at one end of the work storage section, for loading and unloading workpieces one by one from the outside, and for fixing the workpieces to corresponding pallets to form an integrated pallet workpiece; The work storage section includes a storage shelf that is installed in an area facing the processing section and stores a plurality of the pallet workpieces on a plurality of shelves, and an automatic pallet exchange device that transports the pallet workpieces between the setup table and the storage shelf and between the storage shelf and the processing section, The storage shelf is provided with removable shelves so that the vertical mounting intervals can be changed, and an opening is provided in a rear wall portion facing the processing section across the automatic pallet changer, through which the shelf can be directly taken in and out from the outside and attached and detached, and an access door is provided to close the opening in an openable and closable manner, A pallet storage jig, in which the pallet workpieces are removably stored, is fixed to each of the shelves in a replaceable manner so that the longitudinal spacing of the shelf can be changed. Each of the pallets is fitted with a wireless recording medium on which various data is stored, and work information relating to the type of work fixed to the pallet is stored in advance in this wireless recording medium, and the work information includes at least a storage arrangement pattern within the storage shelf that is set in advance corresponding to the type of work, and an address that indicates a storage position assigned to each pallet work in the storage arrangement pattern, The system is further equipped with a reading device that reads the work information from the wireless recording medium by wireless communication, and a storage control device that controls the automatic pallet exchange device to transport the pallet work based on the work information read by the reading device, The storage control device, immediately after the transportation of each pallet work from the setup table to the storage shelf has begun, moves the pallet work to the automatic pallet exchange device so that the wireless recording medium passes through a predetermined data read position by the reading device, causing the reading device to read the work information from the wireless recording medium, and based on the work information read, commands the automatic pallet exchange device to store the pallet work in the storage position indicated by the address assigned to the pallet work being transported. This pallet work storage system is characterized in that

2. The pallet storage jig is equipped with a detector that outputs an ON signal when the pallet workpiece is stored, The pallet work storage system according to claim 1, characterized in that the storage control device determines, based on a signal from the detector, whether another pallet work is stored in the pallet storage jig at the target storage position where the automatic pallet exchange device is attempting to store the pallet work.

3. The pallet has a substantially disk-shaped table portion on the upper surface of which the workpiece is fixed, and has a pull bolt protruding downward from the center of the lower surface of the table portion, the pallet storage jig is provided with a cylindrical pallet receiving portion having a dish-shaped seat portion at its upper portion into which the lower portion of the table portion is fitted, The pallet receiving portion has a groove formed in the center of the seating portion for receiving the pull bolt when the table portion is seated, and has a notch portion in communication with a side surface of the cylindrical shape of the pallet receiving portion and a side surface of the groove, 3. A pallet work storage system according to claim 2, wherein the detector is inserted into the notch and detects the pull bolt received in the groove.

4. The pallet storage jig has a width corresponding to the maximum horizontal width of the workpieces to be stored, is detachably fixed to the shelf board, and includes a fixed plate portion having the pallet receiving portion protruding from an upper surface thereof, The pallet receiving portion has a convex portion at the center of its bottom surface that penetrates the fixing plate portion and protrudes downward, The shelf plate has fixing portions for the pallet storage jig provided at a plurality of different, equally spaced positions determined in advance, and the fixing portions have through holes on the upper surface into which the convex portions of the pallet receiving portion can be inserted and removed, and screw holes at multiple locations around each through hole for screwing the bottom surface of the fixing plate portion when the convex portions are inserted into the through holes.

5. The pallet work storage system according to claim 1, characterized in that the storage shelf has a roughly housing shape and is provided with a pair of supporting walls facing each other, and the pair of supporting walls have support portions that detachably support both ends of the roughly rectangular shelf board at opposing wall positions, and are provided at a plurality of different, equally spaced positions in the vertical direction that are predetermined to be apart from each other.

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