JP4332788B2 - Foreign matter inspection device - Google Patents

Description

  The present invention relates to a foreign matter inspection apparatus for inspecting foreign matter contained in an inspection object.

  Conventionally, in the case of an inspected object having a fluid flow path inside, such as an injector for ejecting fluid, inspection of foreign matters remaining inside is an important process. In the case of an injector, if foreign matter remains in the interior, the foreign matter may get caught in the gap between the components, and as a result, the foreign matter may adhere to the malfunction or the valve portion, resulting in a decrease in valve density when the valve is closed. Therefore, it is necessary to inspect the foreign matters remaining inside the inspection object with high accuracy (see, for example, Patent Document 1).

  When inspecting the inspection object as described above, a filter is installed at one end of the inspection object, and a cleaning fluid is poured from the other end. And the foreign material adhering to a to-be-inspected object is collected by filtering the washing | cleaning fluid which passed the to-be-inspected object with filtration means, such as a filter paper, for example. Furthermore, by observing the collected filtering means, the type and quantity of the collected foreign matter are detected.

JP 2002-192091 A

  However, the inspection object is washed for each processing step, and foreign matter is collected by the filtering means. Therefore, the filtering means such as filter paper to be inspected becomes enormous, and there is a problem that the inspection takes a long time when the operator sequentially compares each image with the reference value. In addition, when an abnormality occurs in a certain processing step, it is necessary to find out the filtering means corresponding to the abnormality from the stored filtering means such as filter paper in order to confirm the same symptom that has occurred in the past. Therefore, there is a problem that it takes a long time to identify the cause of the abnormality in the processing process.

  Therefore, an object of the present invention is to provide a foreign substance inspection apparatus in which the cause of an abnormality can be specified easily and with high accuracy in a short time.

In the invention according to any one of claims 1 to 3 , the filtering means is inputted as an image, and the foreign matter detecting means detects data relating to the foreign matter from the inputted image. Examples of the foreign matter data include the type, quantity, or size of the foreign matter. The process specifying means compares the data regarding the detected foreign matter with the reference value recorded in the second recording means. When it is determined that the foreign matter is mixed in the inspection object in any of the plurality of processing steps, it is specified in which of the plurality of processing steps the foreign matter is mixed. That is, input of an image, detection of data related to a foreign object by processing the input image, and identification of a processing process in which an abnormality has occurred from the data related to the detected foreign object are executed as a series of flows. Therefore, it is possible to identify a processing process in which an abnormality has occurred in a short time and with high accuracy. Further, data relating to the detected foreign matter is stored in the first recording means. Therefore, recorded data of similar symptoms that have occurred in the past are retrieved from the data relating to the detected foreign matter. Therefore, the cause can be easily identified as to which of the plurality of processing steps is abnormal.

In the invention described in claim 1 , the reference data has, as a reference value, the number of foreign matters allowed in each processing step for each type of foreign matter. That is, the reference data includes map data of the type of foreign matter, the processing process, and the number of allowable foreign matters. As a result, it is possible to identify a processing step in which an abnormality has occurred in a short time with high accuracy.
In the invention according to claim 2 , the foreign matter generated from the inspection object is detected by separating it into at least a metal and a non-metal. Metal and non-metal have different light reflectivities. For example, a metal is bright because it easily reflects light, and a non-metal is dark because it easily absorbs light. Therefore, the foreign matter is separated into at least a metal and a nonmetal from the brightness of the image input through the filtering means.

In the invention of claim 3 , the filtering means is photographed by the image input means. The photographed image is composed of a plurality of pixels. Therefore, each pixel constituting the photographed image has a predetermined gradation value. For example, since the brightness differs between metal and non-metal, the type of foreign matter can be specified by the gradation value of each pixel. Therefore, it is possible to specify the type of foreign matter and the processing process in which the foreign matter is mixed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the foreign substance inspection apparatus according to an embodiment of the present invention is a foreign substance inspection apparatus 10 that is a computer and includes an input unit 11 such as a keyboard and a mouse, a computer main body 20, and a display 12 as display means. ing. In the foreign matter inspection apparatus 10 according to the present embodiment, an injector that injects fuel into, for example, intake air sucked into an engine is applied as an inspection object. The injector is assembled in a plurality of processing steps and cleaned each time each processing step is performed. The injector is cleaned with a cleaning fluid. The injector is cleaned, for example, by pouring or spraying a cleaning fluid. The cleaning fluid that has passed through the injector is filtered by a filter 13 as a filtering means. Thereby, the foreign matter adhering to the injector or generated from the injector is collected by the filter 13.

  A camera 21 is connected to the computer main body 20 of the foreign object inspection apparatus 10 as image input means. The camera 21 has an imaging unit composed of a plurality of imaging elements such as a CCD (Charge Coupled Device). The filter 13 that collects the foreign matter generated from the injector is photographed by the camera 21. The captured image is input to the computer main body 20 as an electrical signal.

  The computer main body 20 includes a CPU 22, a storage unit 30, and a processing unit 40. The storage unit 30 constitutes a first storage unit and a second storage unit, and includes a hard disk drive (HDD) 31, a RAM (Random Access Memory) 32, and a ROM (Read Only Memory) 33. The HDD 31 stores a foreign substance inspection program that is software for causing a computer to function as the foreign substance inspection apparatus 10. Further, reference data is recorded in the HDD 31. The RAM 32 temporarily stores various types of data processed by the processing unit 40 and processed data. The ROM 33 stores computer programs for controlling the processing unit 40 and each unit of the foreign matter inspection apparatus 10. CPU22 controls each part of the foreign material inspection apparatus 10 according to a foreign material inspection program.

  The processing unit 40 includes an image processing unit 41, a foreign object detection unit 42, and a process specifying unit 43. The image processing unit 41 processes an image input from the camera 21. The image input from the camera 21 is composed of a plurality of pixels corresponding to a plurality of imaging elements of the imaging unit. The plurality of pixels constituting the image each have an electrical signal corresponding to the brightness of the input image. In the image processing unit 41, digital image data is created from an electrical signal for each pixel constituting the image input from the camera 21. For example, when generating 8-bit image data, each pixel constituting the image has a gradation value of 0 to 255.

  The foreign matter detection unit 42 detects the type and quantity of foreign matter from the image data created by the image processing unit 41. The foreign matters filtered by the filter 13 include, for example, metallic foreign matters and non-metallic foreign matters. The metal foreign matter is, for example, burrs generated in the body or the like forming the injector, or wear powder generated by contact between members. Further, the non-metallic foreign matter is, for example, dust or dust floating in a facility where each processing step is performed. Metal foreign objects are more likely to reflect light than non-metallic foreign objects. Therefore, when the filter 13 is photographed with the camera 21, the metal foreign matter becomes brighter than other foreign matters. On the other hand, even if it is a metal foreign material, for example, oxidized metal is difficult to reflect light. Therefore, when the filter 13 is photographed by the camera 21, the metal foreign matter includes a relatively dark metal oxide. Non-metallic foreign matter is less likely to reflect light than metallic foreign matter. In addition, non-metallic foreign matter includes transparent foreign matter that hardly reflects light. That is, the brightness of a foreign object varies depending on the type when it is captured in an image. Thus, the foreign object detection unit 42 identifies the type of foreign object from the gradation value of each pixel constituting the image data.

  The pixels constituting the image data are sufficiently small compared to the size of the foreign matter. For this reason, the foreign matter forms a group of a plurality of pixels having approximate gradation values in the image. By detecting the number of groups of pixels, the number of specific types of foreign matters is detected. Further, the size of the foreign matter is detected by detecting the number of pixels that form this group of pixels. Thus, the foreign object detector 42 detects the size of the foreign object in addition to the type and quantity of the foreign object.

  The process specifying unit 43 specifies in which of the injector processing steps the foreign matter is generated from the type and quantity of the foreign matter detected by the foreign matter detection unit 42 and the reference data recorded in the HDD 31. The reference data is data in which, for example, as shown in FIG. 2, the number of foreign matters allowed for each processing step is set as a reference value for each type of foreign matter. For example, in the processing step A, the allowable number of foreign substances A is 10, and the allowable number of foreign substances C is one. At this time, when the number of foreign matters in a certain processing step is larger than the reference value set in the reference data, the step specifying unit 43 specifies that foreign matters are mixed in the processing step. In the reference data shown in FIG. 2, the molding process, the assembly process, and the inspection process are further divided into three element processes, and reference values for the foreign matter A, the foreign matter B, and the foreign matter C are set for each of the elementary steps. Yes. However, the number of processing steps, the element steps constituting each processing step, the type of foreign matter, and the like can be arbitrarily changed according to the applied steps.

Next, the operation of the foreign matter inspection apparatus having the above configuration will be described with reference to FIG.
(Foreign matter collection)
The injector is cleaned for each processing step during assembly. Here, the processing steps include, for example, a processing step for performing processing by cutting or polishing a metal member, an assembling step for assembling each member, and an inspection step for inspecting the final injector performance. Therefore, for example, the injector is subjected to the first cleaning in the processing step, the second cleaning is performed in the assembly step, and the third cleaning is performed in the inspection step. The processing process is not limited to the above-described processing process, assembly process, and inspection process, and may include other processes.

  The injector is cleaned with a cleaning fluid such as water or a solvent. At this time, the cleaning fluid that has passed through the injector is filtered by the filter 13. By filtering the cleaning fluid with the filter 13, foreign matter generated from the injector and removed by the cleaning fluid is collected by the filter 13 (S101). The foreign matter collected by the filter 13 has different characteristics for each processing step. For example, in the processing step, metal members are mainly cut or polished, so that the generated foreign matter is mainly metal. The foreign object inspection may be a whole inspection for all of the manufactured injectors, or a sampling inspection for any of the manufactured injectors.

(Input image)
When the collection of the foreign matter by the filter 13 is completed, the filter 13 that has filtered the foreign matter is transferred to the foreign matter inspection apparatus 10 (S102). In the foreign matter inspection apparatus 10, the filter 13 is photographed using the camera 21. The captured image of the filter 13 is input to the computer main body 20 as an electrical signal (S103). The image processing unit 41 of the computer main body 20 generates digital image data from the electric signal input from the camera 21. Then, image processing is performed on the digital image data by a predetermined algorithm (S104). The image processing unit 41 converts the input electric signal into a gradation value for each pixel constituting the image, and generates image data. The generated image data is temporarily stored in the RAM 32 of the storage unit 30 and an image based on the image data is displayed on the display 12.

(Detection of foreign matter)
When the input of the image is completed, the foreign object detection unit 42 detects the type and quantity of the foreign object from the generated image data (S105). The foreign object detection unit 42 detects the type, quantity and size of the foreign object from the gradation value for each pixel constituting the image data. The foreign object detection unit 42 may be configured to detect either the type, quantity, or size of a foreign object, or two or more elements among these as data related to the foreign object. As described above, the captured image of the filter 13 includes the background indicating the filter 13 itself and various foreign matters collected by the filter 13. The background filter 13 itself has a substantially uniform gradation value, and is contained most in the image. For this reason, the foreign object detection unit 42 determines that the gradation value that is most contained in the image data is the background filter itself. On the other hand, the foreign substance has a different reflectance, that is, a gradation value for each type. Therefore, the foreign matter detection unit 42 determines the type of foreign matter from the gradation value for each pixel in the captured image of the filter 13. For example, a pixel having a small gradation value is determined to be a non-metallic foreign matter having a low reflectance, and a pixel having a large gradation value is determined to be a metallic foreign matter having a high reflectance. In addition, the tone value has a predetermined distribution according to the type of foreign matter. Therefore, the type of foreign matter is determined for each gradation value having a size in a predetermined range. In the foreign matter detection unit 42, in addition to metal and nonmetal, an oxidized metal having a low reflectance, a transparent nonmetal, or the like is determined. In addition, the number of foreign objects is detected from the number of pixels composed of a plurality of pixels corresponding to the foreign objects. Further, the size of the foreign matter is detected from the number of pixels constituting the group.

(Data accumulation)
When the detection of the foreign matter is completed, the recording data including the processing process of the inspected filter 13, the sampling number of the injector, the type and quantity of the detected foreign matter, and the image data of the photographed filter 13 are stored in the HDD 31. (S106). By storing the recording data in the HDD 31, a change in the occurrence of foreign matter due to the progress of the processing process is detected.

(Judgment of presence or absence of abnormality)
The process specifying unit 43 compares the record data stored in the HDD 31 with the reference data recorded in the HDD 31 (S107), and determines whether an abnormality has occurred in the processing process (S108). At this time, if the quantity for each type of foreign matter in the recorded data is below the reference value set in the reference data, the process specifying unit 43 determines that no abnormality has occurred in the processing process that is the transfer source of the filter 13. To do. Then, the photographed foreign matter inspection of the filter 13 is finished, and the next foreign matter inspection of the filter 13 is started.

On the other hand, if the quantity for each type of foreign matter in the recorded data exceeds the reference value of the reference data, the process specifying unit 43 determines that foreign matter is mixed in the processing process that is the transfer source of the filter 13 (S109). ). If the process specifying unit 43 determines that an abnormality such as foreign matter is mixed in the processing process that is the transfer source of the filter 13, the display 12 indicates that an abnormality has occurred in the processing process that is the transfer source of the filter 13. Is displayed (S110). Thereby, in the processing step in which an abnormality has occurred, a treatment for eliminating the abnormality is performed. Thereafter, the foreign matter inspection of the photographed filter 13 ends, and the process proceeds to the next foreign matter inspection of the filter 13.
By repeating the above procedure, the foreign matter inspection of the plurality of filters 13 and the identification of the processing process in which an abnormality has occurred are repeatedly executed.

  As mentioned above, according to one Embodiment of this invention demonstrated, the kind and quantity of the foreign material collected by the filter 13 are detected from the image data of the input filter 13. FIG. Then, the type and quantity of the detected foreign matter are compared with the reference value set for each processing step to determine whether a processing step abnormality has occurred and to identify the processing step in which the abnormality has occurred is doing. Input of an image, detection of foreign matter, and presence / absence of an abnormality in a processing process are executed as a series of flows. Therefore, it is possible to identify a processing process in which an abnormality has occurred in a short time and with high accuracy.

  In one embodiment of the present invention, the recording data is stored in the HDD 31. For this reason, when it is determined by the foreign matter inspection of the filter 13 that an abnormality has occurred in the processing process, the record data of similar abnormality that has occurred in the past is retrieved. That is, it is possible to compare the type and quantity of the detected foreign matter with the type and quantity of the foreign matter included in the past recorded data stored in the HDD 31. As a result, it is possible to easily identify what kind of abnormality has occurred in any processing step or what is the cause of the abnormality from the type and quantity of the detected foreign matter. Further, by using the recording data stored in the HDD 31, when a new processing step is added, reference data corresponding to the new processing step can be created from the stored recording data. Further, by accumulating recording data in the HDD 31, it is possible to estimate in advance when an abnormality occurs in each processing step.

  As described above, in the embodiment of the present invention described above, the example in which the injector is applied as the inspection object has been described. However, any inspection object that can be cleaned using a cleaning fluid can be applied without being limited to an injector.

It is a block diagram which shows the foreign material inspection apparatus by one Embodiment of this invention. It is a schematic diagram which shows the reference | standard data applied to the foreign material inspection apparatus by one Embodiment of this invention. It is the schematic which shows the flow of the foreign material inspection method using the foreign material inspection apparatus by one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Foreign substance inspection apparatus, 12 Display (display part), 13 Filter (filtration means), 20 Computer main body, 21 Camera (image input means), 30 Memory | storage part (1st memory | storage means, 2nd memory | storage means), 40 processing part, 41 Image processing unit, 42 Foreign object detection unit, 43 Process identification unit

Claims (3)

A foreign matter inspection apparatus for identifying a processing step in which foreign matter mixed in an inspection object occurs,
An image input means for photographing a filtering means for collecting foreign matter generated from the inspection object;
Processing the image of the filtering means photographed by the image input means, and detecting foreign matter detection data;
First recording means for storing data relating to the foreign matter detected by the foreign matter detection means as recording data;
Second recording means for recording, as reference data, a reference value of data relating to foreign matter mixed in the inspection object in a plurality of processing steps for processing the inspection object;
Data relating to the foreign matter detected by the foreign matter detection means recorded in the first recording means;
Comparing with the reference data recorded in the second recording means and determining that foreign matter has entered the inspection object in any of the plurality of processing steps, foreign matter is mixed in any of the plurality of processing steps. Process identification means for identifying whether or not
When the process specifying unit specifies in which of the plurality of processing steps foreign matter is mixed in the inspection object, the process specifying unit includes a display unit that displays the specified processing step.
The data regarding the foreign matter includes the type of foreign matter and the number of foreign matters for each type,
The reference data includes, as a reference value, the number of foreign substances allowed in each processing step of the plurality of processing steps for each type of foreign matter among the data on the foreign matter detected by the foreign matter detection means,
The process specifying means includes the type of foreign matter detected by the foreign matter detection means and the number of foreign matters for each type, and the number of foreign matters per type allowed for each processing step included in the reference data, The foreign substance inspection apparatus characterized by specifying in which processing step the foreign substance is mixed. The foreign substance detecting means, the foreign substance inspection apparatus according to claim 1, wherein the detecting classified into at least a metal and nonmetal contaminants generated from the object to be inspected. The foreign object detection means includes
Claim 1, characterized in that said from the image of the captured said filter means by the image input unit, detects the tone value of each pixel constituting the image, detects the type of foreign matter in accordance with the gradation value Or the foreign material inspection apparatus of 2 .

Images