JP6359833B2 - Production system - Google Patents

Description

  The present invention relates to a production system capable of controlling a production ratio between varieties in, for example, a mixed variety line production system. The workpiece processed in this production system may be a product (finished product) or a part (unfinished product). In addition, “processing” in this production system includes not only processing for applying some processing / deformation to a material, such as cutting processing, but also processing related to overall production such as assembly and assembly of parts.

  For example, in a vehicle assembly line in a factory, a process from a process for producing various parts to a process for assembling various produced parts integrally is continuously performed in a series of conveyance paths. In addition, a necessary quantity of necessary parts is supplied to each process of the vehicle assembly line (see Patent Document 1).

  In the production system found in such a vehicle assembly line, a plurality of processing lines constituting a series of conveyance paths are alternately provided in series with stock sections for storing (stocking) workpieces. Therefore, when paying attention to a certain processing line, as shown in FIG. 3, a plurality of types (here, four types) of workpieces W1 to W4 (in this case, no matter what type) are provided on the upstream side and the downstream side of the processing line 3. The front stock part 1 and the rear stock part 2 for storing the work W) so as to be able to be carried out by type are arranged.

In the conventional production system, the ratio of the production quantity of the various workpieces W is equalized in order to equalize the production volume of the multiple types of workpieces W while maintaining the production ratio between the workpiece W types in accordance with the production plan. The various workpieces W1 to W4 are sequentially unloaded from the front stock unit 1 toward the processing line 3 in the unloading order obtained by the leveling calculation based on the above. As shown in FIG. 3, this carry-out order instruction is performed by sending a carry-out instruction signal from the ratio board 51 to the front stock board 4, and the carry-out instruction signal from the ratio board 51 is calculated in advance by the ratio board 51 ( This corresponds to the unloading order obtained by leveling calculation.

  Further, in the conventional production system, in order to prevent the occurrence of problems and accidents due to the number of workpieces W carried into the rear stock unit 2 exceeding the storage limit of the rear stock unit 2, FIG. As shown, limit switches 52 and 53 are provided at each position for detecting excessive storage of the work W in the rear stock unit 2 in two stages, and the ratio change limit switch 52 detects the first stage of excessive storage of the work W. Then, a ratio change signal for reducing the production ratio of the work W is sent from the rear stock board 5 to the ratio board 51, and when the over-pool detection limit switch 53 detects the second stage of excessive storage of a work W, the work is detected. A stop signal for instructing to stop the unloading of W is sent from the rear stock board 5 to the ratio board 51.

Japanese Patent No. 4119588

  However, in the above conventional production system, it is not possible to detect the storage shortage of the work in the rear stock part, and in some cases, there is a risk of adverse effects such as delay of progress or stagnation in the subsequent process of the rear stock part.

  The present invention has been made in consideration of the above-described matters, and an object of the present invention is to provide a production system capable of eliminating the shortage of workpiece storage in the rear stock section.

  In order to achieve the above object, a production system according to the present invention includes a front stock portion and a rear stock portion that store a plurality of types of workpieces so that they can be carried out by type, and the plurality of types of workpieces are separated from the front stock portion. After being unloaded and processed in the processing section, the production system is mixed and flows so as to reach the rear stock section, and the number of workpieces loaded from the processing section toward the rear stock section The comparison means for comparing the number of workpieces carried out from the rear stock section, which is the number of workpieces carried out from the rear stock section, according to the type of workpiece, and the order in which workpieces are unloaded from the front stock section based on the result of comparison by the comparison means Unloading order determining means for determining a workpiece, and the unloading order determining means performs a leveling calculation based on a production ratio of a plurality of types of workpieces during the basic unloading sequence of the workpieces. If the value of subtracting the number of the rear stock carried out from the number of the rear stock carried in any work is less than the set range when the free seat is interrupted at an arbitrary ratio, the work is regarded as a storage shortage work The unreserved seat is used as a seat for the under-stored work, and when the under-stored work does not exist, the unloading order is determined by skipping the free seat. Item 1).

  In the production system, the carry-out order determination unit may be configured to be able to make a reservation designation of the change timing of the carry-out order that accompanies a change in the production ratio of a plurality of types of workpieces.

  When the production system according to the present invention is switched to the post-replenishment mode, the number of workpieces to be unloaded from the front stock section is limited so that the number of workpieces to be unloaded from the front stock section does not exceed the number of the rear stock unloaded after the switching time. (Claim 3).

  In this invention, the production system which can eliminate the storage shortage of the workpiece | work in a back stock part is obtained.

  That is, in the production system of the invention according to each claim of the present application, the comparison means compares the number of the rear stock carried in and the number of the rear stock carried out so as to increase the carry-out ratio of the small number of workpieces stored in the rear stock section. In addition, since the unloading order determining means determines the unloading order of the workpieces, the storage shortage of the workpieces in the rear stock unit can be eliminated.

  In the production system according to the second aspect, the change of the production ratio between the workpiece types can be automatically switched at a desired timing, and the convenience can be improved.

  In the production system of the invention according to claim 3, it is possible to limit the maximum number of workpieces stored in the machining section and the rear stock section, and it is also possible to always grasp the number of workpieces.

It is explanatory drawing which shows roughly the structure of the production system which concerns on one embodiment of this invention. (A) And (B) is explanatory drawing which shows roughly the structure of the process of determining the carrying-out order of a workpiece | work, and the leveling table created in the process. It is explanatory drawing which shows the structure of the conventional production system roughly.

  Embodiments of the present invention will be described below with reference to the drawings.

  The production system according to the present embodiment shown in FIG. 1 has the same basic configuration as that of the conventional production system shown in FIG. 3, and therefore, the same parts are denoted by the same reference numerals and redundant description is omitted here. To do.

  In the production system shown in FIG. 1, plural types (four types in the illustrated example) of works W1 to W4 can be carried out from the front stock unit 1 by type. More specifically, the front stock section 1 is provided with a plurality (four in the illustrated example) of front stock lines 1a to 1d corresponding to a plurality of types of workpieces W, and a plurality of types of workpieces are provided on each of the front stock lines 1a to 1d. W1 to W4 are stored by type.

  At the downstream part of each front stock line 1a to 1d, a dam-like stopper 6 that can be freely protruded and retracted is provided. An example of the processing section) is sent to 3.

  The workpiece W that has reached the processing line 3 is sent so as to be carried into the rear stock unit 2 after passing through the processing device 9 and the inspection / sorting device 10 in order by the conveyor 8. Here, the processing apparatus 9 performs predetermined processing on the workpiece W. The inspection / distribution device 10 performs inspection of the processed workpiece W and distribution based on the result, so that the workpiece W having an abnormality in the inspection result is ejected to the inappropriate product line (NG line) 11. It is configured.

  The workpiece W reaching the rear stock unit 2 is stored in any one of the plurality of rear stock lines 2a to 2d. That is, the rear stock unit 2 is provided with a plurality (four in the illustrated example) of rear stock lines 2a to 2d corresponding to a plurality of types of workpieces W, and each of the rear stock lines 2a to 2d has a plurality of types of workpieces. W1 to W4 are stored by type, and the workpieces W1 to W4 can be carried out from the rear stock unit 2 by type. The rear stock lines 2a to 2d are provided with stoppers 6 in the same manner as the front stock lines 1a to 1d, and the stoppers 6 of the rear stock lines 2a to 2d operate according to instructions from the rear stock board 5. .

  In the present production system in which the work W flows as described above, the carry-out order of the plurality of types of work W carried out from the front stock unit 1 toward the processing line 3 is determined by the ratio board (an example of the carry-out order determination means) 12. When the front stock board 4 which has received the carry-out instruction signal 12a from the ratio board 12 operates the predetermined stopper 6, the work W which has been ordered is carried out from the front stock part 1, and a plurality of kinds of work W mixes and flows. Further, with the completion of the unloading of the workpiece W, the unloading completion signal 4a is transmitted from the previous stock panel 4 to the ratio panel 12.

  Next, a method for determining the order of unloading the workpieces W from the front stock unit 1 in the ratio board 12 will be described. For the sake of simplicity, the following description will be limited to two types of workpieces W1 and W2.

  In this production system, the ratio board 12 executes a leveling program in order to equalize the production amount of a plurality of types of workpieces W while maintaining the production ratio between the types of workpieces W based on the production plan. The basic unloading order of the workpieces W from the front stock unit 1 is determined (step S1) (see FIG. 2A). At this time, the ratio board 12 causes free seats to be interrupted at an arbitrary rate during the basic carry-out order.

  More specifically, as shown in FIG. 2B, the leveling table (instruction table) formed by executing the leveling program is provided with a predetermined number of top seats 12b, and most of the top seats 12b are provided. Is a work W obtained by leveling calculation based on a predetermined ratio of the production quantity of each work W (“1” or “2” in the illustrated example) indicating any one of the work Ws. Assigned according to the unloading order. The remaining top seats 12b are free seats provided at a constant rate (20% in this example), and information indicating that each free seat present at this fixed interval is a free seat (in the illustrated example). “100”) is assigned. The unreserved seat is a top seat 12b used for correcting the work W carry-out order for the purpose of eliminating the storage shortage of the work W in the rear stock unit 2.

  On the other hand, in the present embodiment, it is monitored by the ratio changing panel 13 whether or not the storage of the work W in the rear stock unit 2 has occurred to the extent that the correction of the work W unloading order is necessary (step S2). (See FIGS. 1 and 2A). Here, the ratio changing board 13 determines the number of workpieces W carried from the processing line 3 toward the rear stock unit 2 and the number of workpieces W carried out from the rear stock unit 2 as the number of workpieces W carried out from the rear stock unit 2. It functions as a comparison means for comparing by type of workpiece W.

  Specifically, each time the inspection control panel 14 that controls the inspection / distribution apparatus 10 sends out the workpiece W that has been judged to be normal to the rear stock unit 2, the type information of the workpiece W that has been sent out is included. A production result signal 14 a is output from the inspection control panel 14 to the ratio change panel 13. The ratio changing panel 13 that has received the production result signal 14 a outputs the production result reception completion signal 13 a to the inspection control panel 14. As a method for specifying the workpiece W type information included in the production result signal 14a on the inspection control panel 14, for example, each workpiece W is provided with identification means such as an ID tag or a bar code, and the inspection control panel It is conceivable that 14 reads the product type information of the workpiece W from the identification means.

  Further, every time the rear stock disk 5 that controls each stopper 6 of the rear stock portion 2 carries the workpiece W from the rear stock portion 2 toward the subsequent process (actuates the stopper 6), A shipping record signal 5 a including product type information is output from the rear stock board 5 to the ratio change board 13. Then, the ratio changing board 13 that has received the shipment record signal 5 a outputs a shipment record reception completion signal 13 b to the rear stock board 5. As a method for specifying the workpiece W type information included in the shipment result signal 5a in the rear stock board 5, for example, a command for operating the stoppers 6 of the rear stock lines 2a to 2d for storing the workpieces W by type. It is conceivable to associate the type of each workpiece W with each other.

  The ratio changing panel 13 that has received the production record signal 14a and the shipment record signal 5a as described above compares the number of the rear stock carried in and the number of the subsequent stock carried out according to the type of the workpiece W based on both signals 14a and 5a. If the value obtained by subtracting the number of post-stock carry-outs from the post-stock carry-in number of any work W falls below the set range, the work W is regarded as an under-stored work, and the product information of this under-stored work is included. The ratio change signal 13c is output to the ratio board 12 (step S3) (see FIG. 2A).

  Here, priority is set in advance for all the workpieces W so that no trouble occurs when a plurality of under-stored workpieces occur at the same time, and when a plurality of under-stored workpieces occur at the same time. The ratio changing panel 13 is configured so that the work W having the highest priority among them is an under-storage work. Such superiority or inferiority between the workpieces W may be provided on the ratio plate 12.

  In the ratio board 12 that receives the ratio change signal 13c from the ratio change board 13, the information on the free seat is rewritten to information indicating any one of the workpieces W according to the ratio change signal 13c, and the carry-out instruction code 15 is created. A carry-out instruction is issued according to the code 15 (a carry-out instruction signal 12a is output) (step S4) (see FIG. 2A). If there is no under-stored work, the ratio change signal 13c is not sent from the ratio change board 13 to the ratio board 12, and the ratio board 12 skips the free seat and creates the carry-out instruction code 15 (determines the carry-out order). )

Here, there is a time lag between the detection of the under-stored work in the ratio change panel 13 and the actual supply of the same kind of work W as the under-stored work to the rear stock unit 2, but the production of the under-stored work By setting unreserved seats for temporarily increasing the ratio at a rate (interval) according to the time lag, an excessively large number of workpieces W determined to be under-stored workpieces are unnecessarily carried out from the front stock unit 1. Can be prevented.

  In addition, as described above, the ratio changing panel 13 compares the number of post-stock carry-in and the number of post-stock carry-out according to the type of workpiece W based on the production result signal 14a and the shipment result signal 5a. The number of workpieces W stored in the downstream side of the inspection / sorting device 10 in the line 3 and the rear stock unit 2 can be grasped by type. Therefore, the work W in the rear stock unit 2 can be provided on the basis of the production record signal 14a and the shipment record signal 5a without providing devices such as the two types of limit switches 52 and 53 as in the conventional production system shown in FIG. In this way, when excessive storage of the workpiece W is detected in this way, it can be configured to stop carrying out the workpiece W from the front stock unit 1. With this configuration, it is not necessary to install devices such as limit switches 52 and 53. Therefore, a great amount of time and cost required for this installation can be reduced, and work can be performed in accordance with changes in the production plan. Even when the production ratio of W is changed, it is possible to easily cope with the change, and troublesome work such as changing the limit switches 52 and 53 to another position becomes unnecessary.

  By the way, in the ratio board 51 used in the conventional production system shown in FIG. 3, when an input for changing the production ratio is performed, a calculation based on the new ratio is immediately performed and a leveling table (instruction table) is obtained. And an instruction to carry out the workpiece W based on the new leveling table is issued. Therefore, the operator needs to wait in front of the ratio board 51 and input a new production ratio to the ratio board 51 in accordance with the timing for switching the production ratio.

  Therefore, in this production system, the ratio board 12 is provided with a leveling reservation function, and it is possible to make a reservation designation of the timing of changing the work W carry-out order from the previous stock unit 1 in accordance with the change in the production ratio of multiple types of work W It is said. Specifically, when the number of workpieces W to be carried out before the production ratio is changed is set as a reservation count on the ratio board 12, the ratio board 12 automatically calculates based on the new production ratio after the number of works W is carried out. And the workpiece W is unloaded from the front stock unit 1 in a new unloading order. The counting for this may be performed in any of the front stock board 4, the rear stock board 5, the ratio board 12, and the ratio change board 13.

  For example, if 60 workpieces W are stored in the processing line 3 and the rear stock unit 2 in total and the reservation count is set to 40, 100 units are counted downstream from the rear stock unit 2 from that point in time. When the workpiece W is unloaded, the ratio plate 12 is switched to unload the workpiece W from the front stock unit 1 in accordance with the unloading sequence determined based on the new production ratio. Then, during the period from when the reservation count is set to when the ratio board 12 is switched as described above, even if the ratio change signal 13 c is output from the ratio change board 13 to the ratio board 12, the ratio board 12 does not change the ratio change signal 13 c. And the work W is unloaded from the front stock unit 1 in the unloading order in which free seats are skipped. With such a configuration, it is possible to prevent excessive storage (excess inventory) or shortage of workpieces W in the rear stock unit 2, and it is possible to appropriately maintain the number of workpieces W in each of the rear stock lines 2a to 2d. .

  Further, the production tact in the present production system is not uniform throughout, and the timing at which the workpiece W is carried out from the rear stock unit 2 and the timing at which the ratio board 12 outputs the carry-out instruction signal 12a to the front stock unit 1 are different. Then, if the former timing is always earlier, the tendency of the work W to be insufficient in the rear stock part 2 becomes stronger, and if the latter timing is always earlier, the tendency of the work W to accumulate in the rear stock part 2 becomes stronger.

  Therefore, when the production system has a post-replenishment function, and the production system is switched to the post-replenishment mode that exhibits the post-replenishment function, the number of workpieces W to be carried out from the front stock unit 1 after this switching time. The front stock carry-out number is limited so as not to exceed the rear stock carry-out number.

Specifically, when the present production system is switched to the post-replenishment mode, the ratio changing board 13 transfers the shipment result signal 5a received from the rear stock board 5. Each time the ratio board 12 receives the shipment result signal 5a from the ratio change board 13, it counts one in-process number, and outputs the carry-out instruction signal 12a to the previous stock board 4 by the number of in-process counts. Therefore, the ratio Release 12 which outputs the widget count fraction unloading instruction signal 12 a is newly unless receiving the shipments signal 5a, rather than to output a new unloading instruction signal 12 a before the stock panel 4, The workpiece W is not carried out from the front stock unit 1. Note that switching to the post-replenishment mode can be performed on the ratio board 12 or the ratio change board 13, for example.

  In the production system configured as described above, the number of workpieces W can be always grasped while limiting the maximum number of workpieces W to be stored in the processing line 3 and the rear stock unit 2.

  In addition, this invention is not limited to said embodiment at all, Of course, it can change and implement variously in the range which does not deviate from the summary of this invention. For example, the following modifications can be given.

  In the above-described embodiment, the front stock board 4, the rear stock board 5, the ratio board 12, and the ratio change board 13 are provided in such a manner that signals are exchanged between them, and the stopper 6 is controlled. Instead, for example, the stopper 6 and the like may be collectively controlled by a single programmable controller or the like.

  In the above-described embodiment, the countermeasure for the case where a plurality of under-stored works occur at the same time is performed only by setting priorities for all the works W in advance. When multiple under-stored workpieces occur at a given time, among the multiple under-stored workpieces, the work W having the largest lower width of the rear stock carry-in number relative to the rear stock carry-out number is given priority, and the lower turn width is maximized. When there are a plurality of workpieces W, the under-stored workpieces may be determined according to the priority order.

  Needless to say, the above modifications may be combined as appropriate.

1 front stock section 1a front stock line 1b front stock line 1c front stock line 1d front stock line 2 rear stock section 2a rear stock line 2b rear stock line 2c rear stock line 2d rear stock line 3 processing line (example of processing section)
4 Front stock panel 4a Unloading completion signal 5 Rear stock panel 5a Shipping result signal 6 Stopper 8 Conveyor 9 Processing device 10 Inspection / sorting device 11 Improper product line 12 Ratio panel 12a Unloading instruction signal 12b Top seat 13 Ratio change panel 13a Receiving production results Completion signal 13b Shipment result receipt completion signal 13c Ratio change signal 14 Inspection control panel 14a Production result signal 15 Unload instruction code 51 Ratio panel 52 Ratio change limit switch 53 Overpool detection limit switch W Work W1 Work W2 Work W3 Work W4 Work

Claims (3)

It comprises a front stock portion and a rear stock portion for storing a plurality of types of workpieces so that they can be carried out by type, and the plurality of types of workpieces are unloaded from the front stock portion and processed by the processing portion, and then the rear stock portion. A production system that flows in a mixed manner,
Comparing means for comparing the number of workpieces that are transferred from the processing unit to the rear stock unit, and the number of workpieces that are transferred from the rear stock unit, and the number of workpieces that are transferred from the rear stock unit according to the type of workpiece,
Based on the result of the comparison by the comparison means, comprising unloading order determining means for determining the unloading order of workpieces from the previous stock unit ,
The unloading order determining means interrupts a free seat at an arbitrary rate during the basic unloading order of the workpieces obtained by executing the leveling calculation based on the production ratio of a plurality of types of workpieces. When the value obtained by subtracting the number of the rear stock carried out from the number of the rear stock carried is equal to or less than the set range, the workpiece is set as an understored work, the free seat is set as the seat of the understored work, and the understored work is The production system is configured to determine the carry-out order by skipping the unreserved seat when it does not exist . The production system according to claim 1, wherein the carry-out order determination unit is configured to be able to make a reservation designation of the timing of changing the carry-out order in accordance with a change in the production ratio of a plurality of types of workpieces . When the mode is switched to the post-replenishment mode, the number of workpieces to be carried out from the front stock section is limited so that the number of workpieces to be carried out from the front stock section does not exceed the number of the rear stock carried out after the switching point. The production system according to claim 1 or 2.