Visual detection method for cross-flow fan blade

Abstract

The invention discloses a cross-flow fan visual detection method which comprises the steps that a cross-flow fan is fed to a detection station, the cross-flow fan is positioned and clamped, a visual detection device is arranged on the detection station, and the visual detection device comprises a detection camera, a coaxial light source and a back side light source; the coaxial light source and the back side light source are arranged on the upper front side and the upper rear side of the cross-flow fan correspondingly, and the coaxial light source irradiates the upper front side of the cross-flow fan. Driving the cross-flow fan blade to rotate and detecting the rotation angle, and shooting the rotating cross-flow fan blade by the detection camera so as to obtain images at different rotation angles. The coaxial light source and the back side light source illuminate the upper side of the cross-flow fan downwards on the front upper side and the rear upper side of the cross-flow fan, the detection camera shoots the cross-flow fan obliquely on the front upper side of the cross-flow fan, a good light environment can be obtained, the detection precision is improved, automatic visual detection of the cross-flow fan is achieved, the shooting effect is good, and the detection efficiency is improved. And the structure is simple.

Description

Technical Field

[0001] This invention relates to the field of cross-flow fan blade manufacturing technology, and in particular to a visual inspection method for cross-flow fan blades. Background Technology

[0002] Cross-flow fan blades are core components for generating airflow in air conditioners, household fans, and other appliances. During the production process, cross-flow fan blades need to be inspected to ensure quality. Visual inspection is one such inspection, which involves checking the blades for defects such as dents or misalignment.

[0003] Currently, the main method for inspecting the appearance of cross-flow fan blades is to manually pick up the products for visual inspection, which is inefficient, labor-intensive, and prone to missed or incorrect inspections. Other methods use vision cameras for inspection, but the inspection results are not good enough and the inspection methods and structures are more complex. Summary of the Invention

[0004] The main objective of this invention is to propose a visual inspection method for cross-flow fan blades, aiming to solve the technical problems of low efficiency, high labor costs, and easy omissions and errors in the existing technology that relies on manual visual inspection, as well as the complex inspection methods and structures of visual camera inspection.

[0005] To achieve the above objectives, this invention proposes a visual inspection method for cross-flow fan blades, comprising: The cross-flow fan blade to be inspected is loaded into the inspection station, and positioned and clamped. The inspection station is equipped with a vision inspection device, which includes an inspection camera, a coaxial light source, and a back-side light source. The coaxial light source and the back-side light source are respectively located on the upper front side and the upper rear side of the cross-flow fan blade. The coaxial light source illuminates the upper front side of the cross-flow fan blade, and the back-side light source illuminates the upper rear side of the cross-flow fan blade. The inspection camera is located in front of the coaxial light source and is coaxially arranged with the coaxial light source. The cross-flow fan blades are rotated and the rotation angle is detected. The detection camera takes pictures of the rotating cross-flow fan blades to obtain images at different rotation angles.

[0006] The cross-flow fan blade to be inspected is loaded, positioned, and clamped at the inspection station. During inspection, the cross-flow fan blade rotates. A visual inspection device is installed at the inspection station. A coaxial light source and a back-side light source illuminate the upper side of the cross-flow fan blade from the upper front and upper rear sides, respectively. The inspection camera is tilted at the upper front side of the cross-flow fan blade to take pictures, which can obtain a better lighting environment and improve the inspection accuracy. Moreover, when the cross-flow fan blade is loaded, the inspection camera, coaxial light source, and back-side light source do not need to move upward to avoid a misalignment position, thus realizing automatic visual inspection of the cross-flow fan blade with good imaging effect and simple structure.

[0007] Preferably, the angle between the shooting direction of the detection camera and the illumination direction of the back-side light source is 90-120 degrees. At this angle, the light from the back-side light source and the light from the coaxial light source together create a better lighting effect in the shooting area, which can more effectively highlight defects on the blades and improve detection accuracy. In addition, at this angle, the illumination range can be adapted to the detection of cross-flow fan blades of different diameters.

[0008] Preferably, the position of the detection camera can be adjusted to be closer to or further away from the cross-flow fan blades. After manually adjusting the camera's focus, when it is necessary to switch between different specifications of cross-flow fan blades, the distance between the detection camera and the cross-flow fan blades can be adjusted to adjust the image clarity, facilitating the switching between different products.

[0009] Preferably, the visual inspection includes blade defect detection and overall length detection; The blade defect detection includes acquiring images of the cross-flow fan blade at multiple positions along its length corresponding to different rotation angles, and analyzing whether there are defect features in the images; The overall length detection includes acquiring images of the end plates at both ends of the cross-flow fan blade, and determining the distance between the two end plates based on the position of the end plates in the images to obtain the overall length of the cross-flow fan blade.

[0010] On the one hand, visual inspection can detect defects in the blades, such as dents, scratches, or deformations, through image analysis; on the other hand, cameras located at the left and right ends can detect the ends of the cross-flow fan blades and obtain the distance between the two ends, thereby determining whether the length of the cross-flow fan blades is up to standard.

[0011] Preferably, before loading the cross-flow fan blades to the testing station or before starting the testing, the cross-flow fan blades are rotated and the origin feature position of the cross-flow fan blades is detected at the same time. The origin feature position of the cross-flow fan blades is used to determine the origin of the rotation angle of the cross-flow fan blades during the testing.

[0012] Since the angle and position of the cross-flow fan blades are uncertain during material feeding, after finding the origin, the characteristic position of the origin can be used as the origin of the rotation angle of the cross-flow fan blades to determine the detection values ​​at different rotation angles during subsequent testing.

[0013] Preferably, when a defective cross-flow fan blade is detected, a mark indicating the defect is made on the cross-flow fan blade. Marking the cross-flow fan blade when a defective defect is detected facilitates identification. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] In the attached diagram: 1-Cross-flow fan blade, 21-Detection camera, 22-Coaxial light source, 23-Backside light source.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that if the embodiments of the present invention involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0021] like Figure 1 As shown, a method for detecting a cross-flow fan blade 1 includes the following steps: The cross-flow fan blade 1 to be inspected is loaded into the inspection station, and the cross-flow fan blade 1 is positioned and clamped. The inspection station is equipped with a vision inspection device, which includes an inspection camera 21, a coaxial light source 22 and a back side light source 23. The coaxial light source 22 and the back side light source 23 are respectively located on the upper front side and the upper rear side of the cross-flow fan blade 1. The coaxial light source 22 illuminates the upper front side of the cross-flow fan blade 1, and the back side light source 23 illuminates the upper rear side of the cross-flow fan blade 1. The inspection camera 21 is located in front of the coaxial light source 22, and the inspection center line of the inspection camera 21 is coaxial with the optical axis of the coaxial light source 22. The cross-flow fan blade 1 is rotated and the rotation angle is detected. The detection camera 21 takes pictures of the rotating cross-flow fan blade 1 to obtain images at different rotation angles.

[0022] The cross-flow fan blade 1 to be inspected is loaded onto the inspection station for positioning and clamping. The cross-flow fan blade 1 to be inspected can be a straight blade, a slanted blade, or a similar type. The clamping method can be set according to the shape of the stepper shaft hole of the cross-flow fan blade 1, such as a round hole, a D-shaped hole, or a clamping end shaft. During inspection, the cross-flow fan blade 1 is rotated. A vision inspection device is set up at the inspection station. The coaxial light source 22 and the back-side light source 23 illuminate the upper side of the cross-flow fan blade 1 downwards from the upper front and upper rear sides. The inspection camera 21 is tilted on the upper front side of the cross-flow fan blade 1 to take pictures of it, which can obtain a better lighting environment and improve the inspection accuracy. Moreover, when the cross-flow fan blade 1 is loaded, the inspection camera 21, the coaxial light source 22, and the back-side light source 23 do not need to move upwards to avoid a misalignment position, thereby realizing automatic vision inspection of the cross-flow fan blade 1 with good imaging effect and simple structure.

[0023] In some specific embodiments, the angle between the shooting direction of the detection camera 21 and the illumination direction of the back-side light source 23 is 90-120 degrees. At this angle, the light from the back-side light source 23 and the light from the coaxial light source 22 together create a better lighting effect in the shooting area, which can more effectively highlight defects on the blades and improve detection accuracy. In addition, at this angle, the illumination range can be adapted to the detection of cross-flow fan blades of different diameters.

[0024] In some specific embodiments, the position of the detection camera 21 can be adjusted to be closer to or further away from the cross-flow fan 1. After manually adjusting the camera's focus, when it is necessary to switch between different specifications of the cross-flow fan 1, the distance between the detection camera 21 and the cross-flow fan 1 can be adjusted to adjust the image clarity, facilitating the switching between different products.

[0025] In some specific embodiments, visual inspection includes blade defect detection and overall length detection; Blade defect detection includes acquiring images of the cross-flow fan blade 1 at multiple positions along its length corresponding to different rotation angles, and analyzing whether there are defect features in the images; The overall length detection includes acquiring images of the end plates at both ends of the cross-flow fan blade 1, and determining the distance between the two end plates based on the position of the end plates in the images to obtain the overall length of the cross-flow fan blade 1.

[0026] There are multiple inspection cameras 21 arranged side by side to inspect the entire length range of the cross-flow fan blade 1. On the one hand, visual inspection can detect defects such as dents, scratches or deformations of the blades through image analysis; on the other hand, the cameras located at the left and right ends can detect the ends of the cross-flow fan blade 1 and obtain the distance between the two ends, thereby determining whether the length of the cross-flow fan blade 1 is qualified.

[0027] In some specific embodiments, before the cross-flow fan blade 1 is loaded to the testing station or before the testing begins, the cross-flow fan blade 1 is rotated and the origin feature position of the cross-flow fan blade 1 is detected at the same time. The origin feature position of the cross-flow fan blade 1 is used to determine the origin of the rotation angle of the cross-flow fan blade 1 during the testing.

[0028] The origin feature position of the cross-flow fan blade 1 can be the locking hole on the blade or other feature points. Specifically, the origin detection device can detect the rotating cross-flow fan blade 1 using a laser sensor. When the laser sensor detects the parameters of the origin feature position, the origin feature position of the cross-flow fan blade 1 can be determined. Since the angular position of the cross-flow fan blade 1 is uncertain during material loading, after finding the origin, this origin feature position can be used as the origin of the rotation angle of the cross-flow fan blade 1 to determine the detection values ​​at different rotation angles during subsequent detection.

[0029] In some specific embodiments, when a defective cross-flow fan blade 1 is detected, a mark indicating the defect is made on the cross-flow fan blade 1. Marking the cross-flow fan blade 1 when a defect is detected facilitates identification. The marking can be done using a marking device, specifically, the marking device may include a marking drive unit and a marking element. The marking drive unit can move the marking element closer to or away from the cross-flow fan blade 1. The marking element can be a marker pen or a stamp. When the marking element contacts the cross-flow fan blade 1, it can leave a mark on the end plate of the cross-flow fan blade 1. Alternatively, the marking device can be an inkjet printer or a laser device, which can spray a mark onto the cross-flow fan blade 1 or apply a mark using a laser.

[0030] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A visual inspection method for cross-flow fan blades, characterized in that, Includes the following steps: The cross-flow fan blade (1) to be inspected is loaded into the inspection station, and the cross-flow fan blade (1) is positioned and clamped. A visual inspection device is provided at the inspection station. The visual inspection device includes an inspection camera (21), a coaxial light source (22), and a back side light source (23). The coaxial light source (22) and the back side light source (23) are respectively located on the upper front side and the upper rear side of the cross-flow fan blade (1). The coaxial light source (22) illuminates the upper front side of the cross-flow fan blade (1), and the back side light source (23) illuminates the upper rear side of the cross-flow fan blade (1). The inspection camera (21) is located on the front side of the coaxial light source (22). The inspection camera (21) is coaxially arranged with the coaxial light source (22). The cross-flow fan blade (1) is rotated and the rotation angle is detected. The detection camera (21) takes pictures of the rotating cross-flow fan blade (1) to obtain images at different rotation angles.

2. The visual inspection method for cross-flow fan blades as described in claim 1, characterized in that, The angle between the shooting direction of the detection camera (21) and the illumination direction of the back light source (23) is 90-120 degrees.

3. The visual inspection method for cross-flow fan blades as described in claim 1, characterized in that, The position of the detection camera (21) can be adjusted to be closer to or further away from the cross-flow fan blade (1).

4. The visual inspection method for cross-flow fan blades as described in claim 1, characterized in that, The visual inspection includes blade defect detection and overall length detection; The blade defect detection includes acquiring images of the cross-flow fan blade (1) at multiple positions along its length corresponding to different rotation angles, and analyzing whether there are defect features in the images; The overall length detection includes acquiring images of the end plates at both ends of the cross-flow fan blade (1) and determining the distance between the two end plates based on the position of the end plates in the images to obtain the overall length of the cross-flow fan blade (1).

5. The visual inspection method for cross-flow fan blades as described in claim 1, characterized in that, Before feeding the cross-flow fan blade (1) to the testing station or before starting the testing, rotate the cross-flow fan blade (1) and simultaneously test the origin feature position of the cross-flow fan blade (1). The origin feature position of the cross-flow fan blade (1) is used to determine the origin of the rotation angle of the cross-flow fan blade (1) during the testing.

6. The visual inspection method for cross-flow fan blades as described in claim 1, characterized in that, When a defective cross-flow fan blade (1) is detected, a mark indicating the defect is made on the cross-flow fan blade (1).

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