JPH07117394B2 - Sheet metal processing inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic device for inspecting a working state in sheet metal working such as a turret punch press (TPP) and a laser working machine.

[0002]

2. Description of the Related Art Conventionally, as a method of inspecting a product in the sheet metal industry, visual inspection, measurement inspection by a scale,
Measurement inspection with calipers, measurement inspection with height gauge,
The method used was a score measurement test, protractor measurement test, etc.

[0003]

In the case of dimension inspection for shearing cutting, etc., measurement inspection by a scale,
It can be easily inspected using inspection methods such as caliper measurement and score measurement.
In the case of P) and processing by a laser processing machine, the diameter of the processed hole is large and small, and the shape of the hole is circular, triangular,
Various shapes such as polygon, ellipse, rectangle, etc., and there are many holes to be machined per one work piece, such as several thousand to 10,000 pieces, so that the conventional manual inspection method requires a long time. There was a problem. In some cases, only one or two sheets can be inspected per day.

Particularly in the case of such a work, oversight of inspection is likely to increase. If processing defects are found in the early stage of inspection, concentration can be maintained, but if no processing defects are found in the first 30%,
It is easy to overlook the remaining parts, and it is easy to overlook the defects.

As described above, the manual inspection method has a problem in that it takes time and its reliability is low. Even if a processing defect is first detected, the processing process must be stopped while the defective portion is corrected. For example, a TTP device that costs about 100 to 250 yen per minute can be used for half a day. There was a problem that stopping for a day or so would be a big loss.

On the other hand, if processing of a large number of works is advanced without waiting for the inspection result, a large number of defective products will be generated at the time when the inspection result becomes defective. In addition, the sheet metal processing method has improved the efficiency, reliability, and accuracy of the processing by computerization of CAD, CAM, etc., but just because one piece is processed appropriately, However, this does not guarantee proper processing.

This is due to selection of machining programs, setting mistakes, work setting position mistakes, mold size errors, mold station setting errors, mold clearance errors, hardware program specification errors, etc. There is a risk that processing defects will occur due to various factors. Visual inspection may be effective for such defects. Incidentally, in recent years, the technique of applying the image processing technique to the inspection is disclosed in Japanese Utility Model Laid-Open No. 3-6505 and Japanese Patent Laid-Open No. 61-10.
It is disclosed in Japanese Patent No. 2507. The former is a camera
This is a technique for measuring the position of a hole or the like of a sheet metal product by taking an image while moving the sheet metal product from one end to the other end. The latter uses a one-dimensional camera that uses a CCD line sensor. The lower part of the line sensor is moved in small steps, the position of the imaged data is grasped according to the timing, and the image of the processed product is displayed on the memory. This is a technology for determining the quality by comparing with the image of the reference product that is generated and input separately. However, the former is to measure the position of the detected hole by grasping the amount of movement of the camera by multiplying the pulse of the stepping motor, and the processing is slow because an image of a wide area cannot be captured at one time. There is a problem. Further, even if the camera is a two-dimensional camera capable of capturing a wide area, since the illumination device is illumination from the side of the optical axis of the camera, there is a problem that the brightness is not uniform in the visual field. Further, although the number and position of holes and the size thereof can be measured, a technique capable of measuring the shape of a sheet metal is not disclosed. Even if the image processing capable of measuring the shape of the sheet metal is provided, it takes time to take an image of the sheet metal while moving the camera and measure the shape of the sheet metal. Therefore, there is a problem that rapid processing is difficult. there were. Although the latter can be compared with the image of the reference product, since it uses a one-dimensional camera with a CCD line sensor, it cannot capture an image of a wide area at the same time as in the former. There is a problem that is slow.
In addition, since a large amount of arithmetic processing is required to measure the shape of the sheet metal, there is a problem that rapid processing is difficult.

Therefore, it is an object of the present invention to provide an apparatus capable of efficiently inspecting the state of a sheet metal with a camera and an image processing apparatus.

[0009]

That is, in the present invention, a two-dimensional camera for photographing a sheet-metal processed work,
The light emitter is arranged in an annular shape around the optical axis of the two-dimensional camera.
Illumination device, distance changing means for changing the distance between the two-dimensional camera and the work, camera moving means for changing the imaging area of the two-dimensional camera, and work moving means for changing the position of the work. Imaging data of the two-dimensional camera
First stage image processing hand to obtain the number of processed holes from the workpiece
And the number of processed holes obtained in the image processing means in the first step
And a predetermined reference number to compare the sheet metal for the work.
First stage determination means for determining quality of processing, and first stage
For workpieces judged to be non-defective by the judgment means of
Workpiece shape data from the image data of the two-dimensional camera
Second stage image processing means for obtaining and second stage image processing means
Work shape data obtained in the step and a predetermined reference shape data
And the quality of sheet metal processing for the workpiece.
A means for providing a second-stage judging means for judging, the focus of the camera, the distance changing means, the camera moving means, and the control means for controlling the work moving means is provided.

[0010]

SUMMARY OF] According to the present invention took the means, when taking a sheet metal machined workpiece 2-dimensional camera, the distance changing means to change the distance between the camera and the workpiece, the workpiece with a desired size To shoot a large area of . Further, when changing the photographing position of the work, the camera moving means moves the camera side and the work moving means also moves the work side. Therefore, the work can be moved to a desired image pickup area in a short time to take an image.

From the data thus photographed, the first stage
Obtain the number of processed holes in the work by the image processing means on the floor,
The judging means of the first stage compares it with a predetermined reference number.
The quality of sheet metal processing for the workpiece.
Immediately judge defective work pieces that do not have the same number of machined holes
it can. Second stage for work that passed this judgment
The second image processing means obtains the work shape data,
Compared with predetermined reference shape data by step judgment means
Then, the quality of the sheet metal working for the work is determined.
In this way, the processed holes that can be judged by simple image processing
Judgment of the number of coincidences and judgment of shapes that require complicated image processing
And are processed separately, enabling efficient determination.
ing. Also, by providing an annular illumination device,
Thus, the brightness within the field of view becomes uniform.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sheet metal working inspection apparatus of the present invention will be described below in detail with reference to the drawings. In the drawing, 1 is a storage section,
2 is a cutting processing part, 3 is a sheet metal processing part by TPP press,
4 is a sheet metal inspection part, 5 is a bending part, 6 is a welding part, and 7 is a delivery part.

FIG. 2 shows the details of the sheet metal inspection section 4. 1
Reference numeral 0 is a sheet-worked work, 11 is a camera for photographing the work 10, 12 is a uniaxial table for moving the supported camera 11 in the Z-axis direction, and 13 is an XY provided with the uniaxial table 12. A table 14 is an XY table which moves the set work 10 in the XY axis directions in a horizontal plane. The camera 11 corresponds to a two-dimensional camera.
The uniaxial table 12 corresponds to distance changing means, the XY table 13 corresponds to camera moving means, and the XY table 14 corresponds to work moving means.

The image pickup data of the camera 11 is inputted to the image processing device 15 as a judging means. The camera 1
The focus of 1, the uniaxial table 12, the XY table 13, and the XY table 14 are controlled by the control unit 16. And to get uniform lighting, do
A nut-shaped fluorescent tube 17 was arranged around the camera. This power
The melah corresponds to the illumination device arranged in an annular shape. At this time, the illumination device may be controlled in order to compensate for the change in the brightness of the image due to the elevation of the camera.

In the image processing device 15, the image pickup data is A / D converted, and preprocessing such as correction of brightness due to position and illumination, differentiation processing, binarization processing, expansion processing, thinning processing, pattern matching. Shape data such as the shape of the workpiece 10 and the position, size, and size of the machined hole are obtained by image processing such as standardization processing by. Therefore, as shown in FIG.
As shown in the image,
First-stage image processing circuit 15A for obtaining the number of
The number of processed holes obtained in the image processing circuit 15A of
Comparing with the reference number, it is good for sheet metal processing for the work.
The determination circuit 15B of the first stage for determining the
For the work judged to be non-defective by the judgment circuit 15B
To obtain the work shape data from the image data of the camera.
Second stage image processing circuit 15C and second stage image processing circuit
Workpiece shape data obtained in the logic circuit 15C and a predetermined base
Compare the quasi-shape data and add sheet metal to the work.
Comparing with the second stage judgment circuit 15D for judging the quality of work
And a judgment display device 15E for displaying the judgment result of the quality.
I have it.

This shape data is compared with separately designated reference data, and if they match, it is judged as a good product, and if they do not match, it is judged as a defective product. At this time, as shown in the flowchart of FIG. 3, first, the machined hole in the step 1
Read the number and match / mismatch the number of holes in step 2.
Comparing the results, the inconsistent work is judged as a defective product and processed.
If the number of holes is the same, in step 3
Read the position, size, etc. of the processed hole, and go to step 4
Comparing the position and size of the machined hole Te, determines should match the defective determines that good if they match. like this
In addition, the number of processed holes that can be easily image processed is read and the image processing is performed.
Reading of shape data such as the position and size of a complicated machining hole
Since it is separated from the processing, it is preferable in terms of processing speed and efficient processing . In the flow chart of FIG.
Step 1 corresponds to the image processing means of the first stage,
2 corresponds to the judging means of the first stage, and step 3 is the second stage.
Corresponding to the image processing means on the floor, step 4 is the second stage judgment.
It corresponds to a fixed measure.

When imaging a machined hole having a small diameter, the uniaxial table 12 brings the camera 11 closer to a predetermined distance from the work 10 by a close-up photographing command from the control unit 16. At the same time, a focus adjustment command from the control unit 16 is used to focus on the predetermined distance. In this way, by changing the position of the camera, it is possible to obtain more accurate image data than the method using the zoom lens.

Further, since it is inappropriate to fit the detailed whole image of the workpiece 10 in the frame of the camera, the cameras are sequentially moved from the reference origin position in a predetermined inspection order while the inspection object is inspected. Photograph the processed holes in sequence.
At this time, if the horizontal position of the camera is fixed and only the work is moved, it takes a long time to move,
By moving the camera on the XY table 13, the X-
By moving the work on the Y table 14, it is possible to obtain the entire imaging data of the work in an extremely short time. At this time, the XY table 13 and the X-Y table
The operation amount of the Y table 14 is controlled by a control pulse based on the movement amount calculated by the control unit 16. A limiter for the movement range is provided to prevent deviation from the control range.

Regarding the input of the reference data, if it is directly input from the keyboard, there is a problem in time and reliability, so it is preferable to input the reference data by using a recorded storage medium. As such a storage medium, a magnetic disk, a magnetic tape, a paper tape, or the like, on which data obtained by converting the processing data used in the sheet metal processing section into reference data for inspection is recorded, is preferable. For example, in the machining data, the order of punching is intentionally changed in order to suppress the occurrence of distortion of the work. Therefore, the inspection data may be converted so that the inspection of adjacent positions is performed continuously. It's good.

The number of pixels on one screen is 510 × 39.
When set to 0, the visual field when the measurement resolution is 0.01 mm is approximately 5 mm × 3 mm, the visual field when the measurement resolution is 0.10 mm is approximately 51 mm × 39 mm, and the measurement resolution is 1.
The field of view at 00 mm is about 510 mm × 390 mm. In this way, the field of view is wider than that of line sensors.
Therefore, the work can be determined in a short time.

As soon as a defective portion is found in the work, the sheet metal processing by the sheet metal processing section 3 is temporarily stopped,
Prevent a large number of defective products.

When the work is photographed, a plurality of cameras may share the images, and the work may be electrically combined into one image data. Further, when it is necessary to photograph a three-dimensional work, it is preferable to provide a rotation function in addition to the XY table 14.

[0023]

As described above, according to the sheet metal processing inspection device of the present invention, the image pickup data of the sheet-metal processed work can be used as the first data.
The quality of the sheet metal processing is judged by analyzing the image processing of the second stage and the second stage and comparing it with the reference data, so even in the case of complex sheet metal processing inspection, it is very reliable in a short time. Since it can be inspected by the property, it is possible to improve the efficiency of the sheet metal processing and inspection configuration without stopping the flow of the entire processing process and generating a large number of defective products. In addition, the lighting device
Since it has an annular shape, uniform illumination is obtained and accurate image processing is performed.
Can be done.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a processing system including the present invention.

FIG. 2 is a configuration diagram of a sheet metal processing inspection apparatus of the present embodiment.

FIG. 3 is a schematic flowchart of an inspection method.

[Figure 4] It is a block diagram of a main part.

[Explanation of symbols]

10 Work 11 Two-dimensional Camera 12 Distance Change Means (1 Axis Table) 13 Camera Moving Means (XY Table) 14 Work Moving Means (XY Table) 15A First Stage Image Processing Means (Image Processing Device) 15B No. 1-stage determination means (image processing apparatus) 15C 1st-stage image processing means (image processing apparatus) 15D 1st-stage determination means (image processing apparatus) 16 Control means (control unit) 17 Lighting device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References: Kaihei 3-6505 (JP, U) JP 61-102507 (JP, A) JP 62-263834 (JP, A) JP Kohei 4- 52645 (JP, Y2)

Claims (1)

[Claims] 1. A two-dimensional mosquito <br/> camera for photographing a sheet metal machined workpiece, light emitters is arranged in an annular shape around the optical axis of the two-dimensional camera
Illumination device, distance changing means for changing the distance between the two-dimensional camera and the work, camera moving means for changing the imaging area of the two-dimensional camera, work moving means for changing the position of the work, The number of machined holes in the workpiece from the image data of the two-dimensional camera
An image processing unit of the first stage to obtain, the number of processing hole obtained in the image processing means in the first stage a predetermined
The first step of judging the quality of sheet metal processing for the workpiece by comparing with the reference number of
And the work judged to be non-defective by the judgment means of
In contrast, the shape of the work from the image data of the two-dimensional camera
An image processing unit of the second step of obtaining data, workpiece shape data obtained in the image processing unit of the second stage
And the predetermined reference shape data to compare the workpiece.
And a control means for controlling the focus of the camera, the distance changing means, the camera moving means, and the work moving means. Characteristic sheet metal processing inspection device.