CN205333535U - Metal strainometer defect automatic check out system - Google Patents

Abstract

The utility model discloses an automatic detection system for metal strain gauge defects, which belongs to a strain gauge detection device. The system includes a feeding leveling mechanism, a visual detection mechanism, a laser marking mechanism, a waste product marking mechanism and a manipulator assembly. The above-mentioned feeding leveling mechanism, visual inspection mechanism, laser coding mechanism and waste labeling mechanism are respectively installed on the feeding station, visual inspection station, coding station and waste labeling station under the manipulator assembly; the visual inspection mechanism, Both the laser marking mechanism and the waste labeling mechanism are connected to the control system; through multiple stations in the system, the strain gauges are loaded, visually inspected, laser coded, and waste marked in sequence. The visual inspection mechanism passes a unified image recognition standard The strain gauges on the workstation are tested, and the waste marking system sprays marks on the unqualified strain gauges, which effectively avoids the occurrence of missed inspections, improves the efficiency of strain gauge detection, and reduces labor intensity.

Description

An automatic detection system for metal strain gauge defects

technical field

The utility model relates to a strain gauge detection device, more specifically, the utility model mainly relates to a metal strain gauge defect automatic detection system.

Background technique

Resistance strain gauge (Resistance strain gauge) is a kind of transducer (also known as resistance strain gauge) that can convert the strain on engineering components, that is, the size change into resistance change, referred to as strain gauge for short. Generally, it is composed of sensitive grid, lead wire, adhesive, substrate and cover layer. The finished strain gauge is a sandwich structure, which is composed of base material, metal foil and cladding material; the specifications and shapes of the strain gauge products are different, and the grids are arranged horizontally, vertically, 45 degrees obliquely and circularly, etc. There are uniaxial, Divided into biaxial and triaxial, the internal structure of the strain gauge is very small. Generally, the grid width is 25-40 μm, and the grid spacing is 40-60 μm. Most strain gauge products are small in size, generally less than 10mm in length and width, and some special products have longer grids, which can reach 10mm.

Automatic Optical Inspection (Automatic Optical Inspection - AOI). It is a new type of testing technology that has only emerged in recent years. It has developed rapidly and was first applied to the detection of integrated circuits. At present, many manufacturers have launched AOI testing equipment with different performances for different purposes. In terms of use, AOI has the following two main purposes: final quality and process tracking (Processtracking).

Due to the characteristics of high reliability, high precision, high efficiency and easy operation, AOI machine vision inspection equipment has developed rapidly in PCB (printed circuit board: Printed Circuit Board), SMT (surface mount technology: Surface Mounted Technology) and other industries. The minimum resolution that the equipment can detect is generally 0.1mm, and the world-leading Israeli Opal UltraDiscovery series products can reach 7μm.

At present, the traditional quality inspection of strain gauges is all done manually. The entire strain gauge is magnified by 20 times, illuminated by backlight, and manually inspected to judge the defects of the strain gauge. This operation method has the following problems: one is that due to manual operation, the judgment standards cannot be unified, and it is easy to miss inspection; Occupational diseases, such as lumbar spine, cervical spine, eyes, etc. Therefore, it is necessary to study and improve the strain gauge detection system.

Utility model content

One of the purposes of this utility model is to provide an automatic detection system for metal strain gauge defects in view of the above-mentioned deficiencies, in order to solve the problem that the judging criteria for the appearance of strain gauge quality by manual visual inspection in the prior art cannot be unified, easy to miss inspection, and manual labor. High strength, low detection efficiency and other technical problems.

In order to solve the above-mentioned technical problems, the utility model adopts the following technical solutions:

The utility model provides an automatic detection system for metal strain gauge defects. The system includes a feeding leveling mechanism, a visual inspection mechanism, a laser marking mechanism, a waste product marking mechanism and a manipulator assembly. The detection mechanism, the laser coding mechanism and the waste labeling mechanism are respectively installed on the feeding station, the visual inspection station, the coding station and the waste labeling station under the manipulator assembly; the visual detection mechanism, the laser coding mechanism and the The waste labeling mechanisms are all connected to the control system; the feeding leveling mechanism includes a station platform, and a clamping template is placed on the station platform, and a clamping platform is provided on the top of the clamping template, and the clamping platform The upper part is also provided with an electrostatic generator, and a scraper is also installed near the electrostatic generator; the visual detection mechanism includes an image acquisition device and a first two-dimensional servo platform, and the image acquisition device is installed on the first two-dimensional servo platform. Above the platform, the image acquisition device is also connected to the detection system, which is used to identify the defect of the strain gauge in the current image collected by the image acquisition device by the detection system, and record the unqualified strain gauge coordinate information, and transmit it to the control system; the laser marking mechanism includes a laser marking head and a second two-dimensional servo platform, and a clamping table fixing device is installed on the second two-dimensional servo platform for clamping on the second two-dimensional servo platform The strain gage is fixed by a fixing device, and the unique serial number is sprayed on the strain gage by the laser marking head; the waste marking mechanism includes a marking device and a third two-dimensional platform, and the third two-dimensional platform is also installed The clamping table fixing device is used to fix the strain gauge by the clamping table fixing device on the third two-dimensional platform, and the labeling device is installed on the labeling lifting device; it is used for the waste product labeling mechanism to obtain and identify unqualified items from the control system. The coordinate information of the strain gauge is used to mark the waste product of the corresponding strain gauge through the marking device.

As a preference, the further technical solution is: the system also includes a blanking mechanism, which corresponds to the blanking station below the manipulator assembly; the blanking mechanism includes at least a static eliminator for The static electricity of the strain gage installed on the upper part of the clamping table is eliminated by the static eliminator.

A further technical solution is: the manipulator assembly is also connected to the control system, and the clamping table used for carrying and installing the strain gauge by the manipulator passes through each station in turn; and the control system unifies the actions of each manipulator in the manipulator assembly. Coordination and control.

A further technical solution is: the four corners of the clamping template in the feeding leveling mechanism are engraved with cross stars corresponding to the crosses at the four corners of the strain gauge, for the alignment light at the bottom of the clamping template from the cross star pass through, and align with the alignment cross stars at the four corners of the strain gauge on the clamping platform to play the role of strain gauge positioning; the vertical and horizontal directions of the station platform and the clamping template are respectively aligned with the X, Y directions are parallel.

A further technical solution is: the visual detection mechanism is also provided with a transmission light source, and the detection system is integrated in the control system, which is used to control the movement of the first two-dimensional servo platform and the image of the image acquisition device by the control system Acquisition, and then acquire images for defect identification.

A further technical solution is: the control system includes an industrial computer, two programmable controllers are respectively connected to the industrial computer, and one of the programmable controllers is used to control the first two-dimensional servo platform, the second two-dimensional The two-dimensional moving positions of the servo platform and the third two-dimensional servo platform; the other programmable controller is used to control the action of the manipulator assembly and the laser marking mechanism; the visual detection mechanism and the waste product labeling mechanism are respectively connected to the industrial computer, It is used to collect the image of the strain gauge on the visual inspection station by the visual inspection mechanism, and transmit it to the inspection system inside the industrial computer for defect judgment, and then the waste labeling mechanism obtains the coordinates of the strain gauge whose defect judgment result is yes from the interior of the industrial computer. Mark waste.

A further technical solution is: the labeling device in the waste product labeling mechanism is a glue dispenser, which is used to apply quick-drying glue on the solder terminals of the waste strain gauges for labeling by the glue dispenser.

Compared with the prior art, one of the beneficial effects of the utility model is: through multiple stations in the system, the strain gauges are sequentially loaded, visually inspected, laser coded and waste product marked, and the mechanism on each station executes The timing of the corresponding actions is uniformly coordinated and controlled by the control system. The visual inspection mechanism detects the strain gauges on the station through a unified image recognition standard, which effectively avoids the occurrence of missed inspections and improves the efficiency of strain gauge detection; and During the operation of the system, manual labor does not need to participate in the operation of visual recognition and waste labeling, which reduces the labor intensity; at the same time, the structure of the automatic detection system for metal strain gauge defects provided by the utility model is simple, and the strain gauges of various specifications can be adjusted through program adjustment. Automatic waste detection, wide range of applications.

Description of drawings

Fig. 1 is a schematic diagram of the system structure for illustrating an embodiment of the present invention;

Fig. 2 is the structural block diagram of the control system for illustrating an embodiment of the present utility model;

In the figure, 1 is the feeding leveling mechanism, 2 is the visual inspection mechanism, 21 is the transmission light source, 3 is the laser coding mechanism, 4 is the waste labeling mechanism, 5 is the manipulator assembly, Ⅰ is the feeding station, and Ⅱ is the visual inspection Station, III is coding station, IV is marking station of waste products, and V is blanking station.

detailed description

Below in conjunction with accompanying drawing, the utility model is further elaborated.

Referring to Fig. 1, an embodiment of the present invention is an automatic detection system for metal strain gauge defects, which includes a feeding leveling mechanism 1, a visual inspection mechanism 2, a laser marking mechanism 3, a waste marking mechanism 4 and a manipulator Component 5, the aforementioned feeding leveling mechanism 1, visual inspection mechanism 2, laser marking mechanism 3 and waste marking mechanism 4 are respectively installed at the loading station I, visual inspection station II, and coding station below the manipulator assembly 5 Ⅲ and waste product labeling station Ⅳ; and the above-mentioned visual inspection mechanism 2, laser marking mechanism 3 and waste product labeling mechanism 4 need to be connected to the control system;

More specifically, the feeding leveling mechanism 1 includes a station platform on which a clamping template is placed, and a clamping platform is provided on the upper part of the clamping template, and a clamping platform is also provided on the upper part of the clamping platform. An electrostatic generator, a scraping brush matched with it is also installed near the electrostatic generator;

Preferably, the four corners of the clamping template in the feeding leveling mechanism 1 are engraved with cross stars corresponding to the crosses at the four corners of the strain gauge, for the alignment light at the bottom of the clamping template to pass through the cross star, and Aligning the alignment cross stars at the four corners of the strain gauge on the clamping platform plays the role of strain gauge positioning; the vertical and horizontal directions of the station platform and the clamping template are respectively parallel to the X and Y directions of the first two-dimensional servo platform;

As mentioned above, the top of the clamping template is the clamping table, which is made of optical glass material, and the strain gauge to be tested is placed on the clamping table, and the cross beams at the four corners of the clamping template and the crosses at the four corners of the strain gauge are aligned with each other. The bit mark ensures that the vertical and horizontal directions of the strain are parallel to the X and Y directions of the servo platform.

Use the plasma physical vapor deposition method to coat a layer of DLC diamond-like film on the surface of the optical glass material to enhance its anti-friction and wear performance and prolong its service life; the static electricity generator excites static electricity to the strain gauge, so that the strain gauge is adsorbed on the clamping table , the scraper brushes from one side of the strain gauge to the other side, so that the strain gauge is smoothly and stably adsorbed to the clamping table; after the clamping is completed, the manipulator moves the clamping table to the visual inspection station II, and enters the next process.

On the other hand, as shown in Figure 1, in order to improve the working efficiency of the equipment, two or four feeding stations can be used in the design.

The above-mentioned visual detection mechanism 2 includes an image acquisition device (such as a camera or a camera) and a first two-dimensional servo platform, the image acquisition device is installed above the first two-dimensional servo platform, and the image acquisition device is also connected to the detection system, It is used for the detection system to identify the defect of the strain gauge in the current image collected by the image acquisition device, and record the coordinate information of the unqualified strain gauge, and transmit it to the control system;

In order to improve the clarity of the photographed pictures and reduce the error of defect recognition, it is preferable to add a light source in the above-mentioned visual detection mechanism 2, and the detection system can also be integrated in the control system, which is used to control the first two-dimensional servo platform by the control system. Motion and image acquisition device for image acquisition, and then acquire images for defect judgment.

In view of the particularity of the material of the strain gauge to be tested, the transmission light source is selected. The following two points should be paid attention to in the selection of the light source: one is to prevent damage to the strain gauge, and a cold light source with a color temperature of 5500K is used; the other is that the brightness and filter color of the light source are adjustable. This allows for a clear shot of the strain gage foil pattern and eliminates background noise.

The size of the flexible strain gauge substrate is 120×120mm, and the detection accuracy is required to reach 1 μm. This requires the number of pixels to reach 120,000×120,000, or 14.4 billion. The photographing and defect analysis are completed by photographing the strain gauge unit one by one.

The utility model is aimed at common strain gauge samples on the market. The single-chip detection area size of the strain gauge is 7.5mm×8mm. According to the requirement of 1μm resolution, the resolution of the camera needs to meet:

Horizontal pixel: X=W/1=7500/1=7500(pix)

Vertical pixel: Y=L/1=8000/1=8000(pix)

It's also beyond what camera hardware can achieve. In order to solve the hardware limitation, in this embodiment of the utility model, a 16K line scan camera is selected to meet the project requirements. The number of pixels of the camera: 16384Pix, pixel size: 3.5μm, line frequency: 72KHz.

The photosensitive area size of the camera: S=pixel size×resolution=3.5μm×16384=57.344mm, according to the scan width of 8mm, the magnification ratio of 57.344÷8≈7 times can be selected. If a magnification of 3.5 times is selected, the imaging area is 8×3.5=28mm, which is located in the very center of the CCD.

Software processing is calculated with a sub-pixel magnification of 3 times:

Imaging accuracy = 3.5μm/(3.5×3) = 0.33μm

According to the magnification of 3.5 times, there are a total of 7.5mm×3.5÷3.5μm=7500 pixels in the length direction of the monolithic strain gauge, and the scanning time required for the monolithic strain gauge is:

t＝7500÷72kHz≈0.1 second

The first two-dimensional servo platform mentioned above drives the strain gauge to be tested to move in a zigzag along the X and Y directions. One movement of the servo platform can take pictures of all the strain gauges in this direction, and all the strain gauges on a substrate (120×120mm ² ) can be inspected with only a few back and forth movements.

The servo platform is composed of a servo motor, a driver, a motion controller and a high-precision ball screw with an accuracy of 1 μm. In order to cooperate with the camera's photographing speed, the platform movement speed matches the camera's photographing speed.

The software design of the inspection system provides functions such as standard sample entry, defect specification entry, waste judgment standard entry, real-time display of inspection screens, inspection result recording and output, defect statistics, and system management.

The XCaliper visual development system is used to analyze the image by using two algorithms of difference method and vectorization method to find various defects contained in the picture, and judge whether the product is qualified according to the qualified product judgment standard.

After the visual inspection is completed, the manipulator moves the clamping table to the laser marking station.

The above-mentioned laser coding mechanism 3 includes a laser marking head and a second two-dimensional servo platform, and the second two-dimensional servo platform is equipped with a clamping table fixing device for being fixed by the clamping table on the second two-dimensional servo platform. The device fixes the strain gauge, and the unique serial number is printed on the strain gauge by laser marking;

The waste product labeling mechanism 4 above includes a labeling device and a third two-dimensional platform, and the clamping platform fixing device is installed on the third two-dimensional platform, and is used to fix the strain by the clamping platform fixing device on the third two-dimensional servo platform. The labeling device is installed on the labeling lifting device; it is used to obtain the unqualified strain gauge coordinate information from the control system by the waste labeling mechanism 4, and carry out waste labeling on the corresponding strain gauge through the labeling device. After the labeling is completed, the manipulator Move the clamping table to the unloading station.

Preferably, the labeling device in the waste product labeling mechanism 4 is a glue dispenser, which is used to apply quick-drying glue on the solder terminals of the waste strain gauge by the glue dispenser for labeling.

As mentioned above, each mechanism in the above-mentioned embodiment is controlled by the control system. In this embodiment, the system structure adopted by the inventor is shown in Figure 2. The control system includes an industrial computer, and the industrial computer is respectively Two programmable controllers are connected, one of which is respectively connected to the first two-dimensional servo platform, the second two-dimensional servo platform and the third two-dimensional servo platform to control the first two-dimensional servo platform, the second two-dimensional servo platform The two-dimensional moving positions of the second two-dimensional servo platform and the third two-dimensional servo platform; the other programmable controller is respectively connected to the manipulator assembly and the laser marking mechanism 3 for controlling the manipulator assembly 5 and the laser marking mechanism 3 Actions;

In addition, the visual detection mechanism 2 and waste labeling mechanism 4 mentioned in the above embodiment are respectively connected to the industrial computer for the visual detection mechanism 2 to collect the image of the strain gauge on the visual detection station II and transmit it to the internal detection of the industrial computer. The system performs defect judgment, and then the waste product labeling mechanism 4 obtains the coordinates of the strain gauges whose defect judgment result is yes from the inside of the industrial computer, and performs waste product labeling.

Simultaneously for the convenience of blanking, a blanking mechanism can also be added in the system, which corresponds to the blanking station below the manipulator assembly 5; the blanking mechanism at least includes a static eliminator for eliminating static electricity by the static eliminator. Static electricity of the strain gauge installed on the upper part of the clamping table.

As mentioned above, each mechanism in the system is controlled by the control system. In order to make all the mechanisms in the system coordinated and controlled by the control system, the above-mentioned manipulator assembly 5 can also be connected to the control system. The manipulator transports and installs the clamping table of the strain gauge through each station in turn; and the control system coordinates and controls the actions of each manipulator in the manipulator assembly 5;

The main functions of the metal strain gauge defect automatic detection system in the above-mentioned embodiments of the utility model are as follows:

1. The equipment can adapt to the quality inspection of strain gauge products of various specifications and models;

2. The detection speed is fast, and the shooting speed of the selected camera reaches 72kHz, and the time required for scanning a single strain gauge is t≈0.1 seconds; the shooting time for the entire strain gauge is less than 20 seconds;

3. The judgment and analysis are accurate, the camera resolution is 16k, two-line scanning, the precision is 0.2-0.3μm;

4. Using the principle of electrostatic adsorption, the strain gauge is fully and evenly contacted with the clamping table platform, which ensures the flatness and flatness of the strain gauge, and ensures the clarity of the photo within the small depth of field of the high-pixel camera;

5. The encoder is used to correlate the movement distance of the servo platform with the photographing frequency, which avoids the influence caused by the uneven mechanical movement and the mismatch of scanning, and makes the detection result more reliable;

6. The laser marking system enables the system to establish traceability, avoid mixing and wrong materials, and provide convenience for the integration of the system and other processes in the future.

Based on the automatic detection system for metal strain gauge defects in the above-mentioned embodiments, the inventor carried out a specific test. In the test, the same strain gauge was photographed multiple times, and the photos taken each time were analyzed, and the results obtained were exactly the same, with 20 times magnification. Under normal circumstances, the defective software that is visible to the naked eye can be found out.

In the implementation of the case, through the precise calibration of the servo platform, the corresponding relationship between pixels and sizes can be established, so that the size of the defect can be strictly judged. Combined with the qualified product judgment standard, the system can quickly judge whether the strain gauge is qualified.

In addition, it should be noted that the material feeding leveling mechanism 1, visual inspection mechanism 2, laser marking mechanism 3, waste labeling mechanism 4, and manipulator assembly 5 mentioned in this equipment can all use existing technologies with the same functions. Components, the purpose of this utility model is not the mechanism itself of the aforementioned components, so the structure and function realization principle of the aforementioned mechanism will not be described in detail. Refer to the prior art implementation.

In addition to the above, it also needs to be explained that "one embodiment", "another embodiment", "embodiment" and the like mentioned in this specification refer to specific features, structures or Features are included in at least one embodiment generally described in this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure or characteristic is described in combination with any embodiment, it should be claimed that realizing such feature, structure or characteristic in combination with other embodiments also falls within the scope of the present invention.

Although the invention has been described herein with reference to a number of illustrative embodiments of the invention, it should be understood that many other modifications and implementations can be devised by those skilled in the art which will fall within the scope of this application. within the scope and spirit of the principles disclosed. More specifically, within the scope of the disclosure, drawings and claims of the present application, various modifications and improvements can be made to the components and/or layout of the subject combination layout. In addition to modifications and improvements in component parts and/or layout, other uses will be apparent to those skilled in the art.

Claims (7)

1. An automatic detection system for metal strain gauge defects, characterized in that: the system includes a feeding leveling mechanism (1), a visual inspection mechanism (2), a laser coding mechanism (3), and a waste product labeling mechanism (4) With the manipulator assembly (5), the feeding leveling mechanism (1), the visual inspection mechanism (2), the laser coding mechanism (3) and the waste labeling mechanism (4) are respectively installed on the feeding material below the manipulator assembly (5). Station (Ⅰ), visual inspection station (II), coding station (Ⅲ) and waste labeling station (IV); the visual inspection mechanism (2), laser coding mechanism (3) and waste labeling Mechanisms (4) are all connected to the control system; The feeding leveling mechanism (1) includes a station platform on which a clamping template is placed, a clamping platform is provided on the upper part of the clamping template, and an electrostatic generator is also provided on the upper part of the clamping platform. device, a scraper is also installed near the electrostatic generator; The visual detection mechanism (2) includes an image acquisition device and a first two-dimensional servo platform, the image acquisition device is installed above the first two-dimensional servo platform, and the image acquisition device is also connected to a detection system for The detection system identifies the defects of the strain gauges in the current image collected by the image acquisition device, records the coordinate information of the unqualified strain gauges, and transmits them to the control system; The laser coding mechanism (3) includes a laser marking head and a second two-dimensional servo platform, and a clamping table fixing device is installed on the second two-dimensional servo platform, which is used for loading and unloading on the second two-dimensional servo platform. The clamping table fixing device fixes the strain gauge, and the unique serial number is sprayed on the strain gauge by the laser marking head; The waste labeling mechanism (4) includes a labeling device and a third two-dimensional platform, and a clamping platform fixing device is also installed on the third two-dimensional platform, for the clamping platform fixing device on the third two-dimensional platform The strain gauge is fixed, and the labeling device is installed on the labeling lifting device; it is used for the waste labeling mechanism (4) to obtain the unqualified strain gauge coordinate information from the control system, and to mark the corresponding strain gauge as waste through the labeling device. 2. The metal strain gauge defect automatic detection system according to claim 1, characterized in that: said system also includes a blanking mechanism, said blanking mechanism and the blanking station ( V) Corresponding; the blanking mechanism includes at least a static eliminator, which is used to eliminate the static electricity of the strain gauge installed on the upper part of the clamping table by the static eliminator. 3. The automatic detection system for metal strain gauge defects according to claim 1, characterized in that: the manipulator assembly (5) is also connected to the control system, and the clamping platform for carrying and installing the strain gauge by the manipulator passes through each station; and the control system coordinates and controls the actions of each manipulator in the manipulator assembly (5). 4. The automatic detection system for metal strain gauge defects according to any one of claims 1 to 3, characterized in that: the four corners of the clamping template in the described feeding leveling mechanism (1) are engraved with crosses at the four corners of the strain gauge The corresponding cross star is used to pass through the cross star by the alignment light at the bottom of the clamping template, and align with the alignment cross star at the four corners of the strain gauge on the clamping table to play the role of strain gauge positioning; The vertical and horizontal directions of the station platform and the clamping template are respectively parallel to the X and Y directions of the first two-dimensional servo platform. 5. The metal strain gauge defect automatic detection system according to any one of claims 1 to 3, characterized in that: the visual detection mechanism (2) is also provided with a transmission light source (21), and the detection system is integrated In the control system, the control system is used to control the movement of the first two-dimensional servo platform and the image acquisition of the image acquisition device, and then acquire images for defect identification. 6. The metal strain gauge defect automatic detection system according to any one of claims 1 to 3, characterized in that: the control system includes an industrial computer, and the industrial computer is respectively connected to two programmable controllers, and the One of the programmable controllers is respectively connected to the first two-dimensional servo platform, the second two-dimensional servo platform and the third two-dimensional servo platform, and is used to control the first two-dimensional servo platform, the second two-dimensional servo platform and the third two-dimensional servo platform. The two-dimensional mobile position of the three-dimensional servo platform; the other programmable controller is respectively connected to the manipulator assembly (5) and the laser marking mechanism (3), for controlling the manipulator assembly (5) and the laser marking mechanism (3) Actions; The visual detection mechanism (2) and the waste labeling mechanism (4) are connected to the industrial computer respectively, and are used for collecting the image of the strain gauge on the visual detection station (II) by the visual detection mechanism (2), and transmitting it to the internal computer of the industrial computer. The detection system performs defect judgment, and then the waste product labeling mechanism (4) obtains the coordinates of the strain gauges whose defect judgment result is yes from inside the industrial computer, and performs waste product labeling. 7. The metal strain gauge defect automatic detection system according to any one of claims 1 to 3, characterized in that: the labeling device in the waste product labeling mechanism (4) is a glue dispenser, which is used for dispensing by the glue dispenser Coat quick-drying glue on the solder terminals of waste strain gauges for marking.