Production system

Abstract

A flexible production system (10) for sequentially processing a plurality of types of mixed workpieces (W) comprises: a machine tool (32); a pallet stocker (12) for storing workpieces (W) before and after processing by the machine tool (32); a conveyance system (14) for supplying the workpieces (W) from the pallet stocker (12) to the machine tool (32) and returning the processed workpieces (W) to the pallet stocker (12); a remaining production capacity tabulating unit (116) that calculates a remaining processing time (RW) that totals the planned processing time which is the time required for processing the workpieces (W) stored in the pallet stocker (12); a remaining production capacity recording unit (118) that stores the calculated remaining processing time (RW) together with the time; and a remaining production capacity display unit (100) that displays the remaining processing time (RW) along a time series.

Description

Production System

[0001] The present invention relates to a production system.

[0002] In a production system, since a large number of workpieces are continuously handled, production management is necessary for efficient processing. For this reason, for example, Patent Document 1 discloses a production management system that calculates a material requirements plan based on input information including product item information and configuration information, product production plans, and parts inventory information, and obtains output information including order information and demand information. This makes it possible to quickly calculate parts procurement orders based on the input information, and to evaluate and store the calculated output information.

[0003] However, such known production management systems are primarily intended to manage the inventory and order quantities of the same parts, so if production management is to be performed for a variety of workpieces with different processing times, for example, production management must be performed for each type of workpiece, making it difficult to grasp the overall inventory situation. Alternatively, if multiple types of workpieces with different processing times are forcibly mixed and managed by inventory number, some workpieces may not be able to be processed quickly enough, resulting in a surplus in inventory, or for other workpieces, a situation may arise where inventory is depleted despite available machine tools, and production management may not go smoothly.

[0004] Japanese Patent Application Publication No. 9-38848

[0005] SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a production system that can display and easily manage the remaining machining times of a variety of workpieces having different machining times.

[0006] According to one aspect of the present invention, there is provided a flexible manufacturing system for sequentially processing a mixture of multiple types of workpieces, comprising: a machine tool for processing the workpieces; a pallet stocker for storing the workpieces before and after they are processed by the machine tool; a workpiece supply device for supplying the workpieces from the pallet stocker to the machine tool and returning the processed workpieces to the pallet stocker; a calculation unit for calculating the remaining processing time, which is the total of the planned processing times required to process each of the workpieces stored in the pallet stocker; a memory unit for storing the calculated remaining processing time together with the time at which it was calculated; and a display device for displaying the remaining processing time in chronological order.

[0007] According to one aspect of the present invention, a flexible manufacturing system includes a machine tool, a pallet stocker for storing workpieces before and after machining by the machine tool, and a workpiece supply device for supplying workpieces from the pallet stocker to the machine tool and returning processed workpieces to the pallet stocker. This allows sequential machining of multiple types of workpieces. The system also includes a calculation unit for calculating the remaining machining time, which is the sum of the planned machining times required to process each workpiece waiting in the pallet stocker, and a storage unit for storing the calculated remaining machining time along with the time. This allows the system to calculate and store the remaining machining time, which is the sum of the planned machining times for each workpiece. The system also includes a display unit that displays the remaining machining time in chronological order. This allows changes in the situation, such as the depletion and surplus of the remaining machining time, to be visualized over time, allowing trends to be grasped. This allows operators to easily manage situations where production is stalled or potentially depleted, even when a variety of workpieces with different machining times are mixed, based on the display of the remaining machining time.

[0008] Fig. 1 shows a plan view of a flexible manufacturing system according to an embodiment. Fig. 2 shows a side view of a pallet stocker according to an embodiment. Fig. 3 shows a block diagram of a flexible manufacturing system according to an embodiment. Fig. 4 shows an example of a display of the remaining processing time according to an embodiment. Fig. 5 shows an example of a display of the remaining processing time according to a modified example of the flexible manufacturing system.

[0009] A flexible manufacturing system according to an embodiment will be described below with reference to the accompanying drawings. Similar or corresponding elements are designated by the same reference numerals, and duplicated explanations will be omitted. For ease of understanding, the scale of the drawings may be changed.

[0010] FIG. 1 shows a schematic plan view of a flexible manufacturing system 10 (hereinafter referred to as the "production system 10") for producing and processing a variety of workpieces. FIG. 2 shows a schematic side view of a pallet stocker (storage shelf) 12. The production system 10 includes pallets P on which workpieces W are attached, and the pallet stocker 12 configured as a storage shelf for storing individual pallets P. As shown in FIG. 2, the pallet stocker 12 has multiple stock areas S of different heights for storing pallets P, and each stock area S has a pair of legs Sa for supporting the pallet P. The pallet stocker 12 is electrically connected to a production system controller 110 (see FIG. 1) for managing and controlling the processing process, and is configured to communicate information about the type and number of workpieces W stored in the pallet stocker 12 with the production system controller 110.

[0011] As shown in Figure 1, the production system 10 is provided with one or more (two in Figure 1) machining centers 26A, 26B equipped with machine tools 32 for machining workpieces W. The production system 10 also includes workpiece setup devices 34A, 34B (hereinafter referred to as "setup devices 34A, 34B") that allow an operator to attach or remove workpieces W to or from a pallet P. The setup devices 34A, 34B are electrically connected to the production system control device 110 and are configured to be able to communicate with the production system control device 110 information about the type and number of workpieces W that have been set up on the pallet P by the setup devices 34A, 34B.

[0012] The production system 10 includes a conveying system 14 as a workpiece supply device for transporting a pallet P on which a workpiece W is attached so that the workpiece W can be transferred between a pallet stocker 12, machining centers 26A, 26B, and one or more setup devices 34A, 34B.

[0013] The conveyance system 14 includes a conveyance device 18, which includes a carriage 16 for horizontally moving a pallet P, a lifting device 20 and a loading platform 22 for vertically moving the pallet P, and a slide device 24 for moving the pallet P to the loading platform 22. The carriage 16 is configured to run on rails R installed horizontally to move workpieces W between the pallet stocker 12, machining centers 26A, 26B, and setup devices 34A, 34B. The lifting device 20 is configured to be movable up and down by a motor M such as a servo motor, and can move the loading platform 22 connected to the lifting device 20 in the vertical direction. Here, the axial direction parallel to the direction in which the carriage 16 moves is defined as the X-axis direction. Furthermore, the horizontal direction perpendicular to the X-axis direction is defined as the Z-axis direction. Furthermore, the direction parallel to the vertical direction in which the lifting device 20 moves up and down is defined as the Y-axis direction. In this embodiment, the transport device 18 will be described, but the transport device 18 may be in the form of a so-called stacker crane instead of the device shown in FIG. 2 as long as it is capable of transporting the pallet P.

[0014] The slide device 24 is disposed on the loading platform 22 and has one or more slide members that move in the Z-axis direction relative to the loading platform 22 and forks (neither of which is shown) that can engage with the pallet P. Therefore, the slide device 24 can access the machining centers 26A, 26B, the pallet stocker 12, and the setup devices 34A, 34B via the slide members in order to transfer the pallet P on which the workpiece W is attached.

[0015] The conveying system 14 is electrically connected to the production system control device 110 and is configured to transfer workpieces W between the pallet stocker 12, machining centers 26A, 26B, and one or more setup devices 34A, 34B in response to commands from the production system control device 110.

[0016] As shown in FIG. 1 , machining centers 26A, 26B are configured to enable exchange of a pallet P with a workpiece W to be machined and a pallet P with a machined workpiece W between a pallet P mounted in a machining area where machine tool 32 performs machining and a pallet P waiting at a pallet standby position 36 (hereinafter referred to as "standby position 36"). Workpieces W are mounted on pallets P manually or automatically by an operator using setup devices 34A, 34B. Pallets P with workpieces W mounted thereon are automatically transported by transport system 14 between setup devices 34A, 34B, the standby position of pallet changer PC, and pallet stocker 12. Furthermore, machining centers 26A, 26B are equipped with an NC control device 28 for controlling NC machining of machine tool 32 and a tool magazine 30 for storing tools (not shown) to be attached to spindle 33 of machine tool 32. The production system 10 also includes a peripheral device 38 for carrying out pre-processing and post-processing of the machining by the machine tool 32, such as deburring and cleaning (see FIG. 3).

[0017] As shown in FIG. 3 , the production system control device 110 is configured to detect the inventory status of workpieces W in the pallet stocker 12 and the machining and processing status of the workpieces W in the machining centers 26A, 26B and setup devices 34A, 34B, and then control these. To this end, the production system control device 110 includes a process information recording unit 112 that records the status of the workpieces W and determines the work content to be instructed to the pallet stocker 12, the machining centers 26A, 26B, and the setup devices 34A, 34B, and a work command unit 114 that transmits commands from the process information recording unit 112 to the control devices 35, 28, 39 of these devices. This allows the production system control device 110 to operate the conveyance system 14 and load or unload the workpieces W from the pallet stocker 12 in accordance with the machining status of the workpieces W. Furthermore, the production system control device 110 can instruct the machining centers 26A, 26B on the next machining operation to be performed in accordance with the machining status of the workpieces W.

[0018] Specifically, the process information recording unit 112 determines the next work content (work command) to be instructed to each device according to the inventory status and processing status of the workpiece W, and transmits this to the work command unit 114 (F10 in the figure). Upon receiving the work command from the process information recording unit 112, the work command unit 114 transmits the work command to the control device 35 of the setup devices 34A, 34B, the NC control device 28 of the machine tool 32, and the control device 39 of the peripheral device 38 (F20 in the figure). The work command unit 114 is configured to receive work completion signals from the setup devices 34A, 34B, the machine tool 32, and the peripheral device 38 when the instructed process (work) is completed, and transmits this to the process information recording unit 112.

[0019] Furthermore, the production system control device 110 is configured to calculate the remaining machining time RW for various types of workpieces W with different machining times and display the calculated remaining machining time RW. To this end, the production system control device 110 has a remaining production capacity calculation unit 116 as a calculation unit that calculates the remaining machining time RW (see FIG. 4) by adding up the planned machining times, which are the times required to machine each workpiece W stored unmachined in the pallet stocker 12. The production system control device 110 also has a remaining production capacity recording unit 118 as a storage unit that stores the calculated remaining machining time RW and the time at which it was calculated. Furthermore, the production system control device 110 has a remaining production capacity display unit 100 as a display device that displays the remaining machining time RW in chronological order. In the following description, the remaining production capacity display unit 100 will be described as a display device incorporated into the production system control device 110. However, the remaining production capacity display unit 100 may be a display screen of a mobile terminal carried by an operator, a screen on a machine tool control panel, or a screen on a computer used for process control. In this embodiment, each workpiece W stored unmachined in the pallet stocker 12 used in calculating the remaining machining time RW is a workpiece W for which it is known that setup has been completed by receiving a work completion signal from the setup devices 34A, 34B. Each workpiece W for which setup work has been completed is used to calculate the remaining machining time RW, and the total time is calculated. Furthermore, when a work completion signal is received from the machine tool 32, the workpiece W for which the work completion signal was received is determined to have been completed, and is excluded from the workpieces W stored unmachined. The time required for machining a workpiece W for which machining has been completed, which is preset, is subtracted from the remaining machining time RW.

[0020] The remaining production capacity tallying unit 116 acquires information about the work instructed by the work command unit 114 (such as the work content, whether the work has been completed, the time required for processing, and whether any problems have occurred) from the work command unit 114 (F30 in the figure), and also acquires process information such as the standard processing time (standard processing time) for the instructed work and the planned processing of the workpieces W waiting in the pallet stocker 12 from the process information recording unit 112 (F40 in the figure). Therefore, based on the information acquired from the work command unit 114 and the process information recording unit 112, the remaining production capacity tallying unit 116 can tally up the planned processing time, which is the time required for processing, for each planned processing, and calculate the remaining processing time RW. The calculated remaining processing time RW (the tallying result of the remaining production capacity) is stored (recorded) in the remaining production capacity recording unit 118 together with the time of calculation (F50 in the figure). Furthermore, the calculated remaining processing time RW can be displayed in chronological order along the processing time on the remaining production capacity display unit 100 so that the operator can grasp it (F60 in the drawing).

[0021] The production system control device 110 also has an equipment operation information collection unit 122 for sequentially acquiring information (equipment operation information) about the operating status of the operating pallet stocker 12, machining centers 26A, 26B, and setup devices 34A, 34B (F70 in the figure). The actual operating status specifically refers to a state in which machining is being performed (in machining), a standby state before machining begins or after machining is completed (standby), and a state in which an alarm has been issued due to a malfunction of the machine tool 32. Furthermore, the production system control device 110 has an equipment operation information recording unit 120 for recording the acquired equipment operation information. The sequentially acquired operating status can be displayed in chronological order according to the machining time on the remaining production capacity display unit 100.

[0022] Furthermore, the production system control device 110 has a factory calendar recording unit 124 that records the factory calendar of the factory where the production system 10 is installed, i.e., a calendar indicating whether the factory is operating or not. The production system control device 110 also has a worker calendar recording unit 126 that records a calendar indicating the operator's work schedule. Therefore, the remaining production capacity display unit 100 can display the factory calendar (F80 in the figure) and worker calendar (F90 in the figure) together with the remaining processing time RW and the time series of the operating status.

[0023] The effects of the production system 10 according to this embodiment will be described below through an explanation of a display example of the remaining production capacity display unit 100 shown in FIG.

[0024] In the example display shown in FIG. 4 , the middle section of the display shows a time series of changes in the remaining machining time RW, with time on the horizontal axis. The System Load Timeline display in the middle section shows the time change in the level of the remaining machining time RW for the entire production system 10. In this example display, it can be seen that the level of the remaining machining time RW increases as time passes, that is, although setup has been completed, many workpieces W waiting to be machined remain in the pallet stocker 12, resulting in a surplus. The middle section also shows a time series graph of the remaining machining time RW, with the remaining machining time RW at each time on the vertical axis. In this way, by graphically visualizing the remaining machining time RW, which is the sum of the respective scheduled machining times for the workpieces W waiting to be machined, the relationship between the remaining machining time RW and the operating hours of the machine tool 32 can be easily understood. This allows the operator to easily perform production management such as inventory management of the work W and processing management of the machine tool 32, while suppressing or preventing the work W waiting to be processed from waiting longer than necessary in the production system 10 and becoming redundant, or the work W waiting to be processed from running out in the production system 10.

[0025] Furthermore, the lower part of the display shown in Fig. 4 uses a Gantt chart to display the operating status of the machine tools 32 in chronological order. In this example display, the operating status of four machine tools 32 (SP-3165, SP-1850, SP-2277, and SP-3241) that each machine a plurality of types of workpieces W is displayed in chronological order. Here, the operating status displayed is whether the machine tool 32 is currently machining ("running" in the figure) or whether the machine tool 32 is currently waiting (waiting to machine) before machining. Also, the operating status displayed is whether an alarm has occurred ("alarm" in the figure), i.e., whether a warning has been issued, indicating that a problem has occurred with the machine tool 32. Furthermore, the display is configured to be able to display a single block ("single_block" in the figure) that stops the machine tool 32 for each block of the NC program, and an optional stop ("op_stop" in the figure) that stops the machine tool 32 at any timing, which are operations used by the operator to debug the NC program of the machine tool 32 or to temporarily suspend the machine tool 32 when measuring the workpiece W on the machine during machining. This makes it easy to grasp the relationship between the remaining machining time RW and the operating status of the machine tool 32. This makes it easy to take measures (production management), such as increasing the remaining machining time RW, i.e., increasing the inventory of workpieces W, if the machine tool 32 is often in standby mode, or identifying the cause of the alarm and performing maintenance on the machine tool 32 if the machine tool is often in warning mode.

[0026] 4, various types of workpieces W are mixed, and the multiple (four in this example) machine tools do not all have the same specifications, so not all machine tools are configured to perform the same machining. For this reason, as with one machine tool (SP-3165) in the figure, a standby state may occur despite a large amount of remaining machining time RW. According to the production system 10 of this embodiment, the relationship between the remaining machining time RW and the operating status of the machine tool 32 can be visualized and easily understood, making it easy to manage production by, for example, revising the machining content or the machine tools to be installed.

[0027] The production system 10 according to this embodiment includes a machine tool 32, a pallet stocker 12 for storing workpieces W before and after machining by the machine tool 32, and a transport system 14 for supplying workpieces W from the pallet stocker 12 to the machine tool 32 and returning machined workpieces W to the pallet stocker 12, thereby enabling sequential machining of multiple types of mixed workpieces W. The system also includes a remaining production capacity calculation unit 116 that calculates the remaining machining time RW, which is the total planned machining time required to machine each workpiece W waiting in the pallet stocker 12, and a remaining production capacity recording unit 118 that stores the calculated remaining machining time RW along with the time. This allows the remaining machining time RW, which is the total planned machining time for each workpiece W, to be calculated and stored. The system also includes a remaining production capacity display unit 100 that displays the remaining machining time RW over time. This allows changes in the status, such as depletion and surplus of the remaining machining time RW, to be visualized over time, allowing trends to be grasped. This allows the remaining machining time RW of various types of workpieces W with different machining times to be displayed and easily managed.

[0028] According to the production system 10 of this embodiment, the production system 10 includes setup devices 34A, 34B and a standby position 36. The remaining processing time RW can be visualized in the remaining production capacity display unit 100, so the operator can easily determine, via the setup devices 34A, 34B and the standby position 36, whether to input a workpiece W to increase the remaining processing time RW or to retrieve a workpiece W to decrease the remaining processing time RW. This facilitates production management.

[0029] As explained above, the production system 10 according to this embodiment displays the remaining machining time RW of various types of workpieces W with different machining times, making it easy to manage.

[0030] (Modification) Furthermore, the effects of a modification of the remaining production capacity display unit 100 will be described below through an explanation of a display example of the remaining production capacity display unit 100 shown in Fig. 5. Elements similar to or corresponding to those in this embodiment are given the same reference numerals, and duplicate explanations will be omitted.

[0031] In the display example shown in FIG. 5 , the upper part of the display shows a time series graph of the remaining processing time RW, with the vertical axis representing the remaining processing time RW at each time (solid line in the figure). Here, the remaining processing time RW represents the sum of the planned processing time for workpieces W that have been set up and are waiting to be processed and the processing time for workpieces W that are currently being processed. When multiple processes are performed in one setup, the planned processing time for all processes is added together. Furthermore, the planned processing time for workpieces W that have started to be processed is excluded from the remaining processing time RW. In addition to this, a time series graph (dashed line in the figure) is shown with the vertical axis representing the sum of the remaining planned processing time for workpieces W that are currently being processed. Here, the remaining planned processing time for the workpiece W is added when processing starts and subtracted according to the progress of processing. Also shown is a time series graph (dashed line in the figure) with the vertical axis representing the sum of the planned processing time for workpieces W that have been set up but are intentionally put on hold by the operator and are waiting to be processed (dash line in the figure). Here, the planned processing time of the waiting workpiece W is added, and is subtracted when the waiting state is released and processing begins. Therefore, the planned processing time of the workpiece W being processed and the planned processing time of the waiting workpiece W in the remaining processing time RW can be visualized, and the planned processing time of the workpiece W actually stored in the pallet stocker 12 can be clarified. This makes it easy to perform production management of the workpiece W, such as inventory management and processing adjustment.

[0032] Furthermore, the lower part of the display uses a Gantt chart to chronologically display the operating status of the machine tool 32. In this example display, the operating status of two machine tools 32 (MC1, MC2) that machine multiple types of workpieces W is displayed chronologically. Here, the operating status is displayed as "In cycle" (in the figure), in which the machine tool 32 is currently machining, and "Idle" (in the figure), in which the machine tool 32 is currently waiting (waiting to machine). The operating status is also displayed as "Alarm," indicating the occurrence of an alarm, i.e., when a problem occurs with the machine tool 32. This allows the user to easily grasp the relationship between the remaining machining time RW and the operating status of the machine tool 32. For example, if the machine tool 32 is frequently in the standby state, the user can easily take measures (production management), such as increasing the remaining machining time RW, i.e., increasing the inventory of workpieces W; if the machine tool 32 is frequently in the alert state, the user can easily identify the cause of the alarm and perform maintenance on the machine tool 32.

[0033] Furthermore, the upper display shows the appropriate value of the remaining processing time RW with a dotted line. This makes it possible to visualize whether the remaining processing time RW is in excess or insufficient compared to the appropriate value. This makes it easy to manage the production of the workpiece W, such as inventory management and processing adjustment.

[0034] Furthermore, the upper display can use colors, patterns, etc. to distinguish between manned time periods when an operator is present within the production system 10 and unmanned time periods when an operator is outside the production system 10, i.e., when no operator is present within the production system 10. Therefore, for example, during automatic operation at night when no operator is present, it is possible to predict the possibility that the remaining inventory will become zero and adjust the inventory amount.

[0035] Furthermore, according to the production system 10 of the modified example, when the remaining processing time RW becomes zero for a predetermined time, the remaining production capacity display unit 100 is configured to display a first warning, a Starvation warning. Furthermore, even when the remaining processing time RW is not zero, when the remaining processing time RW does not change for a predetermined time, the remaining production capacity display unit 100 is configured to display a second warning, a Stagnation warning. Therefore, when the Starvation warning is displayed, the operator can easily understand that inventory is depleted, and when the Stagnation warning is displayed, processing by the machine tool 32 is stagnating and some kind of trouble is occurring. This allows the operator to avoid excess inventory due to too many pallets waiting to be processed and to easily determine the timing to input material for the workpieces W in order to efficiently operate the production system.

[0036] As explained above, the production system 10 according to the modified example can easily manage the remaining machining time RW of various types of workpieces W having different machining times by displaying them.

[0037] Although the embodiment of the production system 10 has been described above, the present invention is not limited to the above embodiment. In addition to the above, it is believed that a person skilled in the art would understand that various modifications of the above embodiment are possible.

[0038] REFERENCE SIGNS LIST 10 Flexible manufacturing system (manufacturing system) 12 Pallet stocker 14 Conveyor system (workpiece supply device) 32 Machine tool 34A Workpiece setup device (setup device) 34B Workpiece setup device (setup device) 100 Remaining production capacity display unit (display device) 116 Remaining production capacity aggregation unit (calculation unit) 118 Remaining production capacity recording unit (storage unit) W Work (workpiece)

Claims

1. A flexible manufacturing system for sequentially processing a mixture of multiple types of workpieces, comprising: a machine tool for processing the workpieces; a pallet stocker for storing the workpieces before they are processed by the machine tool and the workpieces after they have been processed by the machine tool; a workpiece supplying device for supplying the workpieces from the pallet stocker to the machine tool and returning the processed workpieces to the pallet stocker; a calculation unit for calculating the remaining processing time, which is the total of the planned processing time, which is the time required to process each of the workpieces stored in the pallet stocker; a memory unit for storing the calculated remaining processing time together with the time when it was calculated; and a display device for displaying the remaining processing time in chronological order.

2. A flexible manufacturing system according to claim 1, further comprising: displaying the operating status of said machine tool together with said remaining machining time in said pallet stocker at each of said calculated times.

3. A flexible manufacturing system according to claim 2, wherein the remaining machining time is displayed using a graph, and the operating status of the machine tool is displayed using a Gantt chart.

4. The flexible manufacturing system according to claim 2, wherein the operating status of the machine tool includes: machining, waiting, and warning.

5. The flexible manufacturing system according to claim 2, wherein the operating status of the machine tool is displayed separately for manned time periods when an operator is present and unmanned time periods when the operator is not present.

6. The flexible manufacturing system according to claim 1, further comprising a workpiece setup device.

7. A flexible manufacturing system as claimed in claim 1, which, if the remaining machining time remains at zero for a predetermined period of time, displays a warning indicating that there is a shortage of unmachined workpieces in the pallet stocker, and, if the remaining machining time remains other than zero and does not fluctuate for a predetermined period of time, displays a warning indicating that machining is stagnating.

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