JPH0695292B2 - Cassette layout optimization method for NC mounter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for optimizing a cassette layout when mounting components on an NC mounting machine.

[Prior Art] NC mounters have come to be used as component mounters that automatically mount components when a large number of printed boards are produced. In this case, the NC mounter sets the mounting components in the cassette in advance, and the head automatically picks up the components based on the instructions from the numerical controller and moves them to the mounting location on the printed circuit board, It is an automatic component mounter configured to be mounted on.

When using this type of NC mounter, shortening the working time is an important issue for cost reduction. At the same time, in order to mount the components effectively, it is necessary to set the mounting order in consideration of parameters such as the height of the components and the mounting speed.

Also, when mounting chip components, there are usually the following rules.

In order to prevent interference between the previously mounted part number and the part number when mounting, mount the part number from the lowest height.

The table moving speed of the mounting machine can be sequentially switched from high speed to low speed, but the reverse is not possible, so mounting is performed from the part with the highest mounting speed (table moving speed).

In addition, there is a rule that the area and weight of the part number are used as parameters.

[Problems to be Solved by the Invention] However, in the conventional cassette layout method, the mounting order parameter is ignored at all, or the cassette layout is fixed according to the mounting order parameter. Therefore, in the case of the same mounting order parameter, there is a problem that the cassette layout has not been optimized so as to minimize the mounting time.

The object of the present invention has been made in view of the above point, and under the following constraint conditions that occur in actual mounting machine operation, according to the mounting order parameter, the same mounting order parameter group part number is mounted. It is an object of the present invention to provide a cassette layout optimization method for an NC mounting machine, which can determine the cassette layout such that the route and the cassette layout are optimized so as to have the minimum mounting time.

(Restriction conditions) It is assumed that the cassette has already been fixed for the part numbers that are used frequently on a daily basis. Therefore, the cassette (called a free cassette) to be allocated according to the mounting order at this time may be discontinuous as shown in FIG. In FIG. 4, hatched circles indicate cassettes whose part numbers are already fixed, and open circles indicate free cassettes.

Some part numbers occupy two or more cassettes instead of one.

[Means for Solving the Problems] FIG. 1 is a principle flow of the cassette layout optimizing method of the present invention.

In order to achieve the above-mentioned object, in the present invention, the cassette is fixed in advance for a specific part number under the constraint conditions,
Also, under the constraint that some parts may occupy more than one cassette, the process of inputting and specifying the mounting order parameters and the part numbers of the parts to be placed are weighted with the mounting order parameters, and mounting is performed. After the process of dividing into order level groups, and tentative allocation from the highest mounting order level to freely assigned free cassettes, the mounting time is the minimum for parts belonging to the same mounting order level group. Thus, the mounting path and the cassette layout are determined at the same time, and the provisionally assigned cassette number is updated to a cassette number determined by the determined cassette layout.

[Embodiment] FIG. 2 is a functional block diagram of an apparatus for carrying out the method of the present invention.

Reference numeral 1 is a component placement data file, which is a file in which data (component placement data) including a part number, an XY coordinate value, and a rotation value for a mounted component is stored.

2 is a standard cassette layout data file, which is a data that describes which cassette is fixed to the part number that the user frequently uses (standard cassette layout data)
Is a file that stores.

An input device 3 specifies a mounting order parameter. The user can specify the mounting speed (S), the height (H) of the component, the area (A), and the weight (W) of the mounting order.

Reference numeral 4 is an optimization processing block. Reference numeral 5 is an optimum path data file, which is a file in which data in which the mounting order is determined so as to minimize the mounting time as a result of optimization is stored.

6 is an optimum cassette layout data file, which is a file that stores cassette layout data optimized according to the mounting order parameters and for the same mounting order parameter group number to minimize the mounting time for the entire group number. is there.

An unprocessed component data file 7 is a file that stores data collected about components that have not been assigned to the cassette by the mounting machine and have overflowed. This data becomes input component placement data in the optimization process of the next stage.

The operation of the optimization processing block will be described below with reference to the flowchart of FIG. First, according to the mounting order parameter input from the input device 3, the target part number is weighted, and the part number is classified by the weight.

Next, the standard cassette layout data of the file 2 is referred to, and the cassette number freely assigned this time is determined.

After that, the component placement data read from the file 1 is sorted according to the mounting order parameter. Then, regarding the part number of the component arrangement data, the free cassette is tentatively assigned in descending order of the mounting order parameter level. The part numbers that have not been assigned are output and stored in the unprocessed component file 7.

Next, for the part numbers belonging to the same mounting order level group, the mounting path and the cassette are optimized at the same time. Update free cassette number according to this optimization. This optimization is done for all levels.

The optimized data obtained as described above is the file 6
And is stored as optimum cassette layout data.

The process of simultaneously optimizing the mounting path and the cassette for the part numbers belonging to the same mounting order level group will be described in more detail below.

In this process, the optimum mounting path and cassette are determined simultaneously from the highest mounting order level group.

Some parts may occupy more than one cassette. In this case, allocate two or more free cassettes.

When the cassette width of the part number to be allocated exceeds the width of the array of continuous free cassettes, the part numbers that can be allocated at the same mounting order level are searched and allocation is attempted.

If it is still not possible, as shown in FIG. 5, this cassette is skipped and an attempt is made to assign a part number to the next empty cassette.

In the present invention, it is also possible to remove the constraint condition and optimize it according to the mounting order parameter, and allocate the cassette to the free cassette based on the result. However, in this case, the following problems occur.

If the free cassettes are smaller than the occupied cassette width, they cannot be assigned to the free cassettes.

In the above case, if a free cassette that cannot be allocated is skipped and allocated to a free cassette having a line width that can be allocated, unused cassettes frequently occur.

Since the upper limit of the number of cassettes in one mounting machine is only about 40 to 100, if the number of unused cassettes increases, the number of parts that can be mounted by one mounting machine decreases and two mounting processes are required. In some cases

[Effects of the Invention] As described in detail above, the present invention has the following effects.

The cassette layout follows the mounting order parameters.

It is optimized to minimize the mounting time between the same mounting order parameters.

Therefore, there is an advantage when the mounting order is designated, that is, when the height of the component is designated, for example, it is possible to prevent interference between the component to be mounted later and the component already arranged. Further, there is an effect that the mounting time is minimized for the part numbers of the same mounting order parameter. Further, since the number of cassettes used is also the minimum, the number of parts that can be mounted by one mounting machine is maximized, and the mounting process is less likely to be divided into two.

[Brief description of drawings]

FIG. 1 is a principle flow of a cassette layout optimizing method of the present invention, FIG. 2 is a functional block diagram of an apparatus for carrying out the method of the present invention, and FIG. 3 is a flow chart showing the operation of an optimizing processing block. FIG. 4 is an explanatory diagram for explaining the arrangement of the fixed cassette and the free cassette, and FIG. 5 is an explanatory diagram for explaining the state of assigning a part number to the cassette. 1 ... Parts layout data file, 2 ... Standard cassette layout data file, 3 ... Input device, 4 ... Optimization processing block, 5 ... Optimum path data file, 6 ...
… Optimal cassette layout data file, 7… Unprocessed parts data file.

Claims (1)

[Claims] 1. A method for optimizing a cassette layout when mounting components by an NC mounting machine, wherein a cassette is fixed in advance for a specific part number,
Also, under the constraint that some parts may occupy two or more cassettes, the process of inputting and specifying the mounting order parameters and the part numbers of the parts to be placed are weighted by the mounting order parameters and mounted. After the process of dividing into the order level group and the tentative allocation from the highest mounting order level to the freely assigned cassettes, the mounting time is the minimum for the part numbers belonging to the same mounting order level group. To determine the mounting path and cassette layout at the same time, and to update the temporarily assigned cassette number to a cassette number determined by the determined cassette layout.The cassette layout follows the mounting sequence parameters and the mounting time. The cassette for the NC mounting machine, characterized in that it is determined so that Layouts optimization method.