JP3494573B2 - Inspection device for sheet surface - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet surface inspecting device which closely adheres to a mating member and exerts a sealing action.
The present invention relates to an inspection device for determining the presence / absence of “defect”).

[0002]

2. Description of the Related Art As a conventional seat surface of this type, a seat surface for an injector (fuel injection valve) of a vehicle engine can be mentioned. FIG. 4 shows the case of a so-called in-cylinder injection type engine, but as shown in this figure, in the in-cylinder injection type engine, since the fuel is directly injected into the combustion chamber 1, the injector 2 burns its tip. It is inserted into a mounting hole 4 penetrating the cylinder head 3 and is fixed by a holder 5 while facing the inside of the chamber 1. The seat surface F is formed in the mounting hole 4 so as to have a ring shape having a predetermined width, and the tip of the injector 2 is in contact with the corrugated washer 6.

With this corrugated washer 6, the combustion chamber 1
However, since the high-temperature and high-pressure combustion gas needs to be sealed, the sheet surface F of the cylinder head 3 with which the corrugated washer 6 is in close contact with the corrugated washer 6 as much as possible to prevent defects such as burrows and scratches. Must be avoided. If a defect exceeding a predetermined size occurs, the corrugated washer 6 is insufficiently adhered and the possibility of gas leakage increases. Therefore,
Conventionally, the sheet surface F is visually inspected after the cylinder head 3 is processed.

[0004]

However, the visual inspection is unreliable due to human error or the like, and when a defect is overlooked, the engine with the cylinder head 3 assembled becomes a defective product. Because it ends up, the loss is large. Therefore, assuming that defects are overlooked from the inspection, it is necessary to apply resin coating to all the sheet surfaces F in order to fill those defects. In other words, since an originally unnecessary process is added, the number of manufacturing processes of the cylinder head 3 is increased, which in turn causes a rise in manufacturing cost.

An object of the present invention is to provide a sheet surface inspection apparatus capable of reducing the manufacturing cost by omitting a post-process such as resin coating by reliably determining the presence or absence of a defect on the sheet surface. It is in.

[0006]

To achieve the above object Means for Solving the Problems], the inspection device for a seat surface of the present invention of claim 1, wherein
Image of the sheet surface to be inspected and captured as image information.
The image capturing means to be loaded and the image information captured by the image capturing means
Based on the determination means for determining the presence or absence of defects on the sheet surface
On the seat surface by the area setting means of the judging means.
Covers the entire area where the presence or absence of defects should be judged, and
Two, which do not deviate from the seat surface and overlap each other.
The number of inspection areas is set, and the image is
Predetermined scanning of pixels in each inspection area, obtained from information
Since the defect is detected from the gradation change in the direction,
Further, in the invention of claim 2, the judging means further comprises grouping means.
To prepare multiple inspection areas from the image information
The change in gradation of pixels in each inspection area is detected in the same scanning direction.
The gradation change detecting means divides the groups into groups to be output.
For each group, check each of the inspection areas that belong to each group.
Detects the gradation change of the pixel in the predetermined scanning direction for each set
Since defect detection is sequentially performed by using the method described above, there is no risk of human error such as visual inspection.

Further, the sheet surface of the present invention according to claim 3 is
According to the inspection device, the imaging means can
Injector seat surface formed on the cylinder head
Is captured and captured as image information, and based on that image information
Based on the pixel change situation, the defect on the sheet surface is judged based on
Since this is done, there is no risk of human error such as visual inspection, and it is possible to omit post-processing such as resin coating that assumes the case where a defect leaks from inspection.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the present invention is embodied in an apparatus for inspecting a seat surface for an injector formed in a cylinder head of a cylinder injection engine will be described below. The sheet surface F that is the target of the inspection apparatus of this embodiment is exactly the same as that described with reference to FIG. 4 in the related art. Therefore, the description of the shape, the mounting state of the injector 2 and the like will be omitted, and the inspection device itself will be mainly described.

The inspection apparatus of the present embodiment takes in the sheet surface F as image information and determines the presence or absence of defects such as burrows and scratches by utilizing image measurement technology. As shown in Figure 1,
At the time of inspection, the cylinder head 3 is in a single state in which the grinding process of the surface of the sheet surface F has already been completed, and the injector or the like has not been mounted yet. The cylinder head 3
It is positioned on the transport path 11 by using a knock pin hole or the like, and is transported in a direction orthogonal to the paper surface in FIG.

A CCD as an image pickup means is provided on the transport path 11.
12 is arranged toward the seat surface F of the cylinder head 3, and its imaging area is set so that the entire seat surface F can be imaged. The CCD 12 has a monitor device 13
The processing device 14 as the dimension estimating means and the determining means is connected via the. The monitor device 13 and the processing device 14 have the same configurations as those used for general image measurement and image recognition, and the image information captured by the CCD 12 is input to the processing device 14 and processed. ,
The image information of the imaged sheet surface F (shown in FIG. 2) or the image information regarding the determination result of the presence or absence of a defect (shown in FIG. 3) is displayed on the monitor device 13.

Next, a procedure for inspecting the sheet surface F using the inspecting apparatus configured as described above will be described. As described in the related art, when the sheet surface F has a defect exceeding a predetermined size, it is considered to be defective. The cylinder head 3 is conveyed by the conveyance path 11, and when the sheet surface F thereof enters the image pickup area corresponding to the CCD 12, the cylinder head 3 is temporarily stopped and the CCD 12 performs an image pickup process. For example, 4
In the case of the cylinder head 3 of the cylinder, the conveyance is stopped at each of the four sheet surfaces F, and images are taken. The image pickup processing by the CCD 12 is 0.04 mm between scanning lines.
Done in. The obtained image information is input to the processing device 14 via the monitor device 13, and analog signal processing such as amplification, contour correction, shading correction, digital conversion, noise removal is performed in the same way as a general signal processing procedure in the processing device 14. , Digital signal processing such as distortion correction is performed and sequentially stored in a built-in memory.

In parallel with this, the processing apparatus 1 sequentially reads the stored image information of each sheet surface F from the memory,
Determine the presence or absence of defects. Here, as shown in FIG. 2, on the seat surface F, the corrugated washer 6 is actually
The tip of the injector 2 comes into close contact with the via 2 (shown in FIG. 4) in a ring-shaped region with a width of about 0.5 mm indicated by hatching. Therefore, it is in this area that the presence or absence of defects becomes a problem, and eight rectangular inspection areas E1 to E8 that overlap each other so as to cover the entire area.
E8 is preset. Then, the presence or absence of a defect is determined for each of the inspection areas E1 to E8 as described below. The reason that the inspection areas E1 to E8 do not protrude from the sheet surface F is to prevent erroneous determination of the outer and inner edge portions as defects.

First, in the scanning area E1, the gradation change in the S1 direction of each pixel is sequentially determined. If there is a defect, as shown in FIG. 3, the gradation of the pixel suddenly changes to the dark side corresponding to the dimension of the defect G in the S1 direction. Therefore, a range in which the gradation exceeds a preset threshold Lx is obtained, The range is the defect S1
It is estimated to be the dimension in the direction. Similarly, within the scanning region E2, the gradation change of each pixel in the S1 direction is determined, and then,
In the scanning area E3 and the scanning area E4, the gradation change in the S1 direction is determined.

Further, in the scanning regions E1 to E4, it is determined whether the gradation changes in the S2 direction orthogonal to S1.
That is, as described above, the scanning line interval at the time of imaging is 0.04.
Since it is mm, when a narrow scratch having a width smaller than that is present in the S1 direction, it is overlooked even if the apparent length exceeds 0.2 mm. Therefore, the determination is made again from the orthogonal S2 direction.

After that, in the scanning areas E5 to E8, the gradation change of each pixel in the S3 direction forming 45 degrees with respect to S1 and S2 is determined, and in the scanning areas E5 to E8, S3 is also determined. The change in gradation in the S4 direction orthogonal to is determined. This completes the defect determination processing based on the image information. When the presence of defects exceeding 0.2 mm is not estimated in all of the determination processes, a non-defective product is determined. When the presence of defects exceeding 0.2 mm is estimated in any of the determination processes, defective product determination is performed. Give it down. Then, for example, the cylinder head 3 having the seat surface F that has been determined as a defective product
It is only necessary to take a countermeasure such as sorting only the other one from the transport path 11.

As described above, in the inspection device of this embodiment,
The sheet surface F is captured as image information, and the presence or absence of a defect is determined by using an image measurement technique. Therefore, there is no possibility of human error such as the conventional visual inspection, and the quality of the sheet surface F can be judged with extremely high reliability. As a result, it is possible to reduce the number of manufacturing steps by omitting the resin coating on the seat surface F, which has been conventionally performed.
Therefore, the manufacturing cost of the cylinder head 3 can be significantly reduced.

By the way, although the above embodiment is embodied as a device for inspecting the seat surface F for the injector formed on the cylinder head 3, the present invention is not limited to this and is not limited to this. Any sheet surface may be used as long as it is a sheet surface that closely adheres to a member and exerts a sealing action and it is necessary to prevent defects such as burrows and scratches.

Further, in the above embodiment, eight rectangular inspection areas E1 to E8 which overlap each other are set so as to cover the ring-shaped sheet surface F without exception, and these areas E1 to E8 are set. The defect size was estimated from the gradation change in two orthogonal directions, and a defect was judged when the size exceeded a predetermined size. However, the inspection procedure is not limited to the above method, and for example, the number and shape of the inspection areas E1 to E8 are changed according to the shape of the sheet surface F, or the gradation change determination direction is set to one direction. Decrease or increase in three or more directions, or make a defect determination immediately when the gradation of a pixel shifts to a dark side beyond a predetermined threshold value without estimating a specific defect size. May be.

[0019]

As described [Effect Invention above in detail, according to the inspection apparatus for a sheet surface of the invention of claim 1, the area setting unit
Therefore, the entire area where the presence or absence of defects on the sheet surface should be judged
Cover and over each other without departing from the seat surface
Tone change detection means by setting multiple inspection areas to be wrapped
The pixels in each inspection area obtained from the image information by
The defect is detected from the gradation change in the predetermined scanning direction.
In addition, according to the seat surface inspection device of the invention of claim 2,
For example, a plurality of inspection areas can be obtained from the image information.
It is necessary to detect the gradation change of pixels in the inspection area in the same scanning direction.
The inspection area belonging to each group is divided into groups.
Each is the floor of the pixel in the predetermined scanning direction for each set.
Since the tone change is detected and the defects are sequentially detected, it is possible to judge the quality of the sheet surface with extremely high reliability without the possibility of human error such as visual inspection.

According to the sheet surface inspection apparatus of the third aspect of the present invention, the sheet surface for the injector is used as the image information, and the defect size is estimated from the image information to determine the quality. There is no risk of human error such as visual inspection, and it is possible to judge the quality of the sheet surface with extremely high reliability. As a result, after resin coating, etc. By omitting steps, the number of manufacturing steps can be reduced, and thus the manufacturing cost of the cylinder head can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a sheet surface inspection apparatus of an embodiment.

FIG. 2 is a front view of a seat ring showing a relationship between inspection areas.

FIG. 3 is an explanatory diagram showing a gradation change of a pixel when a defect occurs.

FIG. 4 is a partial cross-sectional view of a cylinder head showing a relationship between a mounted state of an injector and a seat surface.

[Explanation of symbols]

2 injectors 3 cylinder head 12 CCD (imaging means) 14 Processing device (dimension estimation means, determination means) F seat surface

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-49717 (JP, A) JP-A-7-55723 (JP, A) JP-A-6-300546 (JP, A) JP-A-7- 27714 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 21/84-21/958 G01B 11/00-11/30 G06T 1/00-9/40

Claims (3)

(57) [Claims] 1. An image pickup means for picking up an image of a sheet surface to be inspected and fetched as image information, and a judging means for judging the presence or absence of a defect on the sheet surface based on the image information fetched by the image pickup means. Prepare ,
The determining means covers the entire area where the presence or absence of defects on the sheet surface should be determined.
-Also, overrun each other without departing from the seat surface
Area setting means for setting a plurality of inspection areas to be wrapped, and a position of a pixel in each inspection area obtained from the image information.
Gradation change detection that detects defects from the gradation change in the constant scanning direction
Output means, and the determination means is the inspection area of any one of the gradation change detection means.
Defect is detected from the gradation change in either scanning direction of
The sheet surface inspection apparatus is characterized by determining that there is a defect in the sheet surface when the sheet surface is defective . 2. The determination means is configured to detect the plurality of inspection areas.
Of the pixels in each inspection area, obtained from the image information
A group that divides gradation changes into groups that should be detected in the same scanning direction
And a gradation change detecting means for each group,
Image each area in the specified scanning direction for each group.
Characterized by detecting the gradation change of the element and sequentially detecting defects
The sheet surface inspection device according to claim 1. 3. The image pickup means is for a cylinder injection type engine.
Injector seat surface formed on the cylinder head
An apparatus for inspecting a seat surface according to claim 1, which images
Place