JP2733926B2 - Production ratio control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production ratio control device in a production line such as a vehicle, and more particularly to an improvement in a function of changing the production ratio. 2. Description of the Related Art In a production line such as a vehicle, a plurality of types of workpieces often need to be processed on the same line. In such a case, it is necessary to sequentially input the respective workpieces at an appropriate ratio without bias, for example, due to supply of parts to the production line. For this reason, a production ratio control device 10 as shown in FIG. 6 has been conventionally used. This production ratio control device 10 includes an input interface 1
2, Supply work operation control unit 14, Output interface 1
6. It consists of a supply order data memory 18. The input interface 12 supplies the post-process stock conveyor stock amount detection signal a to the supply work calculation control unit 14 for stocking the work that has been processed in the target processing process. The supply work operation control unit 14 includes a supply order data memory 18
The work to be processed next is determined based on the stock amount of the post-process stock conveyor based on the coded work supply sequence data and the signal a stored in. Then, the result is output as the input instruction signal b via the output interface 16. Here, the coded work supply sequence data stored in the supply sequence data memory 18 is as shown in FIG. Thus, the coded work supply sequence data consists of three digits. The coded work supply sequence data includes information on the type of work and whether the work is a free seat. The type of the work is represented by a number corresponding thereto, and whether or not the work is a free seat is represented by whether or not 100 is added. [Problems to be Solved by the Invention] Such a conventional production ratio control device 10 does not have a function of automatically changing the production ratio. Therefore, when changing the ratio, the operator had to do this. Therefore, there were the following problems. (A) The ratio change must be performed at the time when the ratio change is required in the processing step. For this reason, there is a restriction on the time for starting the work, and the burden on the worker is large. (B) The operator must constantly monitor the timing of the change of the ratio, which is burdensome. (C) Since the operator changes the ratio, it is difficult to finely set the timing of the ratio change. In order to solve these problems, it is conceivable to use a communication line and change the ratio by a higher-level control device such as a host computer. However, such a method has a problem that the communication line must be provided and the cost is high, and there is a large risk in the event that the host control device fails. Incidentally, such a production ratio control device is disclosed in Japanese Patent Application Laid-Open No. 61-2652.
No. 51, JP-A-61-265252. The present invention has been made in order to solve such a problem. Since the ratio is automatically changed, the timing of the change is not required to be monitored, and a host computer is not used. It is an object to provide a production ratio control device that can be avoided. [Means for Solving the Problems] The present invention relates to a supply sequence data buffer for storing new supply sequence data in a production ratio control device for controlling the input of a work in accordance with supply sequence data stored in a supply sequence data memory. And a change timing counter unit that counts the number of work input instructions based on the number of work inputs and counts the number of work input instructions based on this work input number, and changes the number of work input instructions. A data transfer unit for supplying the supply sequence data stored in the supply sequence data buffer to the supply sequence data memory when the number of workpieces to be supplied defining the timing is reached, and set when a ratio change is instructed; Reset when data is transferred by the data transfer unit and change A flag storage unit for storing a flag indicating whether or not to count the number of workpieces input in order to measure the change timing in the timing counter unit, and instructing the change timing at an arbitrary timing to change the production ratio Is performed. [Operation] The production ratio control device of the present invention controls the input of the work in accordance with the supply order data stored in the supply order data memory therein. When the supply order data stored in the supply order data memory is changed, first, the changed supply order data is written to the supply order data buffer. Then, the change timing counter section stores the input number of workpieces as the change timing. The change timing is detected by counting the input of the work, and the work supply sequence data is transferred from the supply sequence data buffer to the supply sequence data memory accordingly.
Therefore, the work supply order data can be changed at a timing according to the change timing. Further, since the count of the input workpieces in the change timing counter section can be controlled by the flag, the count of the change timing can be reliably controlled. Embodiment A production ratio control device according to a position embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the production ratio control device 10 receives a signal a about the stock amount in the post-process stock and outputs a signal b about the work input similarly to the device of FIG. And an input interface similar to that of FIG.
12, Supply work calculation control unit 14, Output interface 1
6. It has a supply order data memory 18. Then, in the production ratio control device 10 in this embodiment, the supply order data buffer 20, the change timing counter unit 22,
It has a data transfer unit 24. Note that a programmable controller is used for such a production ratio control device 10. Here, the production ratio control device 10 in this example
It is used for controlling a production line as shown in the figure. In FIG. 2, workpieces to be machined are stocked in the front stock 30 classified according to vehicle type. These workpieces are processed by the front stock stopper 32 in the machining process.
It is sequentially supplied to 34. Finished workpieces are sorted by vehicle type by the rear stock stopper 36 and stored in the post-process stock.
Stocked at 38. Here, the post-process stock 38 is provided with two limit switches 40 each for detecting the stock amount of the work for each vehicle type. Then, a signal a based on the stock amount by the limit switch is supplied to the production ratio control device 10. Then, the production ratio control device 10 controls the front stock stopper 32 according to the work input instruction signal b, and controls the input of the work into the machining process 34. The supply work calculation control unit 14 of the production ratio control device 10 determines the next input work according to the coded work supply order data stored in the supply order data memory 18. Here, the coded work supply sequence data is the same as that shown in FIG. When the cord is in the unreserved seat as in the conventional example of FIG. 6, the stock amount of the work is checked by the signal a of the limit switch 40 attached to the post-process stock 38, and the stock amount is constant. If it is below, the work input instruction signal b is output. If the stock amount is equal to or more than the predetermined amount, the flow advances to the next frame number without issuing the work input instruction. If the stock amount of the work is a full work, no work input instruction is issued regardless of whether the work is a fixed seat or a free seat. Here, in this embodiment, the production ratio can be automatically changed. Next, this will be described. 3A, 3B, and 3C show examples of allocation of the supply order data memory 18, the supply order data buffer 20, and the change timing counter unit 22 in the registers of the programmable controller. Thus, in the supply order data memory 18 and the supply order data buffer 20, one coded data is allocated to one address. Further, the change timing counter unit 20 is assigned two addresses of an upper numerical value and a lower numerical value for one address of the flag and the count content. Next, a specific procedure for changing the production ratio will be described with reference to FIG. To change the production ratio, first, the coded work supply sequence data after the ratio change is written into the supply sequence data buffer 20 (supply sequence data buffer 20 data input). Next, the number of works to be input is preset in the counter of the change timing counter section 22 and the flag is set to one. This instructs the start of the ratio changing operation. Here, the data writing to the supply order data buffer 20 and the change timing counter unit 22 uses a function of writing data to the register of the programming device of the programmable controller. This completes the setting of the ratio change timing. Next, a flag in the change timing counter unit 22 is checked (flag = 1?). If the flag is not 1, the change operation does not need to be performed, and the process ends (end). If the flag is 1, it is next checked whether the supply work calculation control unit 22 has issued a work input instruction (work input instruction?). Then, when there is a work input instruction by the supply work calculation control unit 14, 1 is subtracted from the count content of the change timing counter unit 22 (change timing counter unit 22 counter 1). In other words, in this embodiment, the number of workpieces input is used as the change timing. If there is no work input instruction,
Since there is no need to change the contents of the change timing counter 22, the contents are not changed. Next, it is determined whether the counter of the change timing counter unit 22 is 0 (counter = 0?). In other words, it can be seen that the count content is decremented by one each time a work is input, and when the count becomes zero, the change timing has come. If the content of the counter is not 0, the subtraction by the work input instruction is repeated again. If the value of the counter is 0, the coded work supply sequence data after the ratio change stored in the supply sequence data buffer 22 is transferred to the supply sequence data memory because the change is performed. The change, that is, the change of the ratio is performed (supply order data buffer → supply order data memory 18 data transfer). Then, the flag of the change timing counter unit 22 is reset to 0, and the process ends. This also inhibits the count operation in the change timing counter unit 22 and the data transfer operation in the data transfer unit 24. Then, the supply work calculation control unit 14
Is to issue a work input instruction in accordance with the changed data transferred from the supply order data buffer 20 to the supply order data memory 18. FIG. 5 is an external perspective view of an example of the production ratio control device of the present invention. As described above, it is preferable to package the device independently so that various displays can be performed. Thus, according to this embodiment, if the coded work supply sequence data after change and the change timing are input at an arbitrary time, the data can be automatically changed at a desired timing. Further, in this embodiment, the system using the fixed seat and the unreserved seat has been described as the process of the supply work calculation control unit 14, but the present invention is not limited to this system, and the work input control by another system may be used. For example, as shown in Japanese Patent Application Laid-Open No. 61-265251, a system having a table of coded work supply sequence data for all frame Nos. Control unit for supply work calculation
14 may be a method of sequentially determining the supply workpieces by calculation. [Effects of the Invention] As described above, according to the production ratio control device of the present invention, the following effects can be obtained. (A) Since all operations for changing the production ratio can be performed in advance, there is no need to perform operations in real time at the timing of changing the ratio, and there is no restriction on the operation execution time. (B) The operator does not need to monitor the ratio change timing. (C) Even if the timing of the ratio change is set in units of one unit, or in units of seconds or minutes, accurate ratio control can be performed, so that fine change timing can be set. (D) Because it can be configured with a programmable controller,
Costs can be kept low. (E) Since the production ratio control device is a stand-alone device formed independently, even if it breaks down, it does not directly affect other devices. (F) Because it can be configured with a programmable controller,
It is not affected by the installation location and is easy to maintain. (G) Since no communication with the host control device is required, the reliability is high.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of an embodiment of a production ratio control device according to the present invention, and FIG. 2 is a schematic configuration diagram of a system using the production ratio control device of the embodiment. FIG. 3 is an explanatory view showing an example of allocation in the register of the embodiment, FIG. 4 is a flowchart for explaining the operation in the embodiment, and FIG. 5 is a production ratio control device according to the embodiment. FIG. 6 is a block diagram showing a configuration of a production ratio control device according to a conventional example, and FIG. 7 is an explanatory diagram showing contents of work supply order data. 10: Production ratio control device, 12: Input interface, 14: Supply work calculation control unit, 16: Output interface, 18: Supply sequence data memory, 20: Supply sequence data buffer, 22: Change timing Counter unit 24: Data transfer unit.

Claims (1)

(57) [Claims] In a production ratio control device that controls the input of workpieces according to the supply sequence data stored in the supply sequence data memory, a supply sequence data buffer that stores new supply sequence data, and the number of workpieces that define the timing for changing the production ratio The change timing counter unit counts the number of work input instructions based on the number of work inputs and counts the timing of the change. A data transfer unit for supplying the supply order data stored in the supply order data buffer to the supply order data memory; set when a change in ratio is instructed, and reset when data transfer is performed by the data transfer unit Change timing in the change timing counter. And a flag storage unit for storing a flag indicating whether or not to count the number of workpieces to be measured in order to measure the number of workpieces, and instructing a change timing at an arbitrary timing to change a production ratio. And production ratio control device.