A coaxial relationship quick detection fixture based on photosensitive material and its detection method

Abstract

The invention discloses a coaxial relationship rapid inspection tool based on photosensitive materials and an inspection method thereof, which detects the coaxiality of two through holes on the same workpiece to be inspected. An image processing unit and a control unit are installed on the outside of a light shielding box, and a light source, a camera, a sensor and a cylinder are installed in the light shielding box. A photosensitive plate coated with photosensitive resin is placed between the two holes, and both sides are irradiated by the light source. By calculating the coordinates of the center of a circular pattern formed on the photosensitive plate, the coaxial relationship between the two holes can be accurately obtained, and the cylinder output rod is controlled to extend outward to remove the workpiece to be inspected whose coaxial relationship does not meet the requirements. When the coaxial relationship meets the tolerance requirements, the workpiece to be inspected is rotated to a vertical state and falls from a bottom plate outlet into a genuine product bin under the action of gravity. From the workpiece to be inspected entering the light shielding box to detecting the workpiece to be inspected and removing defective products can all be completed automatically, thereby realizing rapid detection of the coaxial relationship of the workpiece to be inspected and improving detection efficiency and detection accuracy.

Description

Technical Field

[0001] The invention belongs to the field of detection technology and relates to a detection tool for coaxial relationship, which detects the coaxiality of two through holes on the same workpiece to be detected. Background Art

[0002] Coaxiality refers to the maximum allowable variation of the center axis of the actual hole being measured relative to the reference axis, which is reflected in the non-concentricity of the center of the circle on the cross section. Various precision parts often involve coaxial holes and related assemblies during operation and installation. The coaxial relationship has a great impact on the quality, work efficiency and service life of products and projects. If the coaxiality deviation between the shaft and the hole is too large, the parts that match the shaft and the hole will deform and get stuck, and even break under high-speed operation conditions. It will also increase friction during the transmission process, affect the use and life of the parts, and cause increased vibration and noise of the entire machine.

[0003] The traditional coaxial relationship detection method requires the production of a standard detection pin shaft and a dial indicator for detection. When detecting the coaxial relationship, the positioning reference needs to be changed many times, resulting in large positioning errors. In addition, for different workpieces, due to different apertures, special detection pin shafts are required, which has a narrow application range. At the same time, the dial indicator is manually operated and read by the measurement personnel, which is inefficient and has large measurement errors. In addition, if the aperture is too small, it is very difficult to detect the coaxial relationship. Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the existing coaxial relationship detection, and to provide a coaxial relationship rapid detection fixture based on photosensitive materials and a detection method thereof, which can realize efficient, automatic and accurate detection of the coaxial relationship of workpieces.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the coaxial relationship rapid inspection fixture based on photosensitive materials of the present invention is: the top plate of the light-shielding box is provided with an inlet, and an outlet is respectively provided at the bottom plate and the left side plate, a defective product bin is placed at the lower left side of the outside, a defective product bin is placed directly below the outlet of the left side plate, and a genuine product bin is placed directly below the outlet of the bottom plate, a first conveyor belt and a second conveyor belt are arranged in parallel with each other and spaced apart from each other on the left and the right in the light-shielding box, the output shaft of the first servo motor arranged horizontally in front and behind is coaxially fixedly connected to the first conveyor belt driving shaft, the lower end of the first conveyor belt is wound around the first conveyor belt driving shaft, and the upper end The belt is wound around the driven shaft of the first conveyor belt; the output shaft of the second servo motor arranged horizontally in front and back is coaxially fixedly connected to the driving shaft of the second conveyor belt; the lower end of the second conveyor belt is wound around the driving shaft of the second conveyor belt, and the upper end is wound around the driven shaft of the second conveyor belt; a photosensitive plate is fixedly connected to the middle of the outer surface of the second conveyor belt, and the photosensitive plate is perpendicular to the outer surface of the second conveyor belt; a number of U-shaped support plates for supporting the workpiece to be inspected are fixedly connected at equal intervals around the outer surface of the first conveyor belt, and the two side plates of the U-shaped plate are arranged in front and back, and the support plate is perpendicular to the outer surface of the first conveyor belt. The two shaft holes of the workpiece to be inspected are They are respectively located on the U-shaped two side plates of the support plate, the photosensitive plate extends to the right side in the middle of the U-shaped opening, blocking the two shaft holes, and the two shaft holes are at equal front-to-back distances from the photosensitive plate; a common through hole is opened at the U-shaped bottom of each support plate and the connection with the first conveyor belt, and a cylinder is arranged at the same height as the outlet at the left side plate, and the output rod of the cylinder faces the outlet at the left side plate; a first light source is arranged on the front side plate inside the light-shielding box, a first camera is arranged just above the first light source, and a second light source is arranged on the rear side plate inside the light-shielding box, the first light source and the second light source are symmetrical about the photosensitive plate, and the first camera and the second camera are symmetrical about the photosensitive plate; a first position sensor is arranged at the same height as the first light source and the second light source, and a second position sensor is arranged at the outlet position of the left side plate; the first camera and the second camera are connected to the image processing unit via signal lines, the output end of the image processing unit is connected to the control unit via signal lines, and the first servo motor, the second servo motor, the cylinder, the first position sensor, the second position sensor, the first light source, and the second light source are connected to the control unit via corresponding signal lines or control lines.

[0006] The technical solution adopted by the detection method of the coaxial relationship rapid detection fixture based on photosensitive materials includes the following steps:

[0007] Step A: The control unit controls the first servo motor and the second servo motor to work simultaneously, so that the movement directions of the first conveyor belt and the second conveyor belt are opposite, the support plate moves with the first conveyor belt, and the photosensitive plate rotates with the second conveyor belt;

[0008] Step B: placing the workpiece to be inspected on the uppermost support plate from the inlet, and the first conveyor belt drives the workpiece to be inspected near the photosensitive plate to move downward, and when the first position sensor detects that the two axial holes of the workpiece to be inspected are at the same height as the first light source and the second light source, the control unit controls the first servo motor and the second servo motor to stop working;

[0009] Step C: The control unit controls the first light source to illuminate the front axial hole of the two axial holes from the front side of the workpiece to be inspected, and the second light source to illuminate the rear axial hole from the rear side, so that a circular pattern is formed on the front and rear surfaces of the photosensitive plate respectively;

[0010] Step D: The control unit controls the first camera to shoot the circular pattern on the front surface of the photosensitive board, and the second camera to shoot the circular pattern on the rear surface of the photosensitive board. The image processing unit calculates the center coordinates of the two circles and determines whether the coaxial relationship of the two circles meets the tolerance requirements:

[0011] Step E: The control unit controls the first servo motor and the second servo motor to work again. When the coaxial relationship determined by the control unit does not meet the tolerance requirements and the second position sensor detects that the workpiece to be inspected moves to the same height as the exit at the left side plate of the light shielding box, the first servo motor and the second servo motor stop working, and the control unit controls the output rod of the cylinder to push the workpiece to be inspected to the left through the common through hole and make it fall into the defective bin; conversely, when the coaxial relationship meets the tolerance requirements, the support plate on which the workpiece to be inspected is placed rotates to a vertical state, and the workpiece to be inspected falls from the bottom plate exit into the genuine bin under the action of gravity.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The inspection tool of the present invention utilizes the principle that photosensitive resin will immediately cause polymerization reaction when irradiated by light source. A photosensitive plate coated with photosensitive resin is placed between two holes, and both sides are irradiated by light source. By calculating the coordinates of the center of the circular pattern formed on the photosensitive plate, the coaxial relationship between the two holes can be accurately obtained, which greatly improves the detection efficiency and detection accuracy.

[0014] 2. The inspection tool of the present invention has a wide application range and is suitable for the coaxial relationship inspection of various workpieces to be inspected relative to two through holes, and is highly practical in actual use.

[0015] 3. An image processing unit and a control unit are installed on the outside of the light shielding box in the inspection fixture of the present invention, and a light source, a camera, a sensor and a cylinder are installed in the light shielding box. The control unit controls the cylinder to start working through the data of the coaxial relationship of the workpiece to be inspected fed back by the image processing unit, and the cylinder output rod extends outward to remove the workpiece to be inspected whose coaxial relationship does not meet the requirements. The detection method has a high degree of automation, and all the steps from the workpiece to be inspected entering the light shielding box to the detection of the workpiece to be inspected and the removal of defective products can be completed automatically, thereby realizing rapid detection of the coaxial relationship of the workpiece to be inspected, improving detection efficiency, reducing the labor intensity of operators, and reducing operating errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0017] Figure 1 A three-dimensional image of the workpiece to be inspected;

[0018] Figure 2 This is an axonometric diagram of the appearance structure of a coaxial relationship quick detection fixture based on photosensitive materials of the present invention;

[0019] Figure 3 for Figure 2 A front cross-sectional view of

[0020] Figure 4 for Figure 3 Schematic diagram of the cross section along the AA direction;

[0021] Figure 5 for Figure 4 Schematic diagram of the cross section along the BB direction;

[0022] In the figure: 1-light shielding box; 2-magnet; 3-first servo motor; 4-first servo motor mounting plate; 5-iron block; 6-second servo motor mounting plate; 7-second servo motor; 8-first light shielding cloth; 9-second conveyor belt driven shaft; 10-photosensitive plate; 11-second conveyor belt; 12-second conveyor belt driving shaft; 13-second light shielding cloth; 14-defective product warehouse; 15-authentic product warehouse; 16-third light shielding cloth; 17-first conveyor belt driving shaft; 18-cylinder mounting plate; 19-cylinder; 20-support plate; 21-first conveyor belt; 22-driven shaft of the first conveyor belt; 23-workpiece to be inspected; 24-second camera; 25-first camera; 26-second light source; 27-first light source; 28-first position sensor; 29-second position sensor; 30-image processing unit; 31-control unit; 801-front unit of the first shading cloth; 802-rear unit of the first shading cloth; 1301-upper unit of the second shading cloth; 1302-lower unit of the second shading cloth; 2301-rear side panel; 2302-front side panel; 2303-rear axle hole; 2304-front axle hole. DETAILED DESCRIPTION

[0023] See also Figure 1 The overall structure of the workpiece 23 to be inspected is usually U-shaped. Figure 1 Take the wheel fork as an example of the workpiece 23 to be inspected. The U-shaped rear side plate 2301 and the front side plate 2302 of the workpiece 23 to be inspected are parallel, and each of the rear side plate 2301 and the front side plate 2302 has an axle hole, namely the rear axle hole 2303 and the front axle hole 2304. The present invention is to detect the coaxiality of the rear axle hole 2303 and the front axle hole 2304.

[0024] See also Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the present invention is a coaxial relationship fast inspection fixture based on photosensitive materials, which has a light shielding box 1, and the interior of the light shielding box 1 is a dark room. A defective bin 14 is placed at the lower left side of the exterior of the light shielding box 1, and a genuine bin 15 is placed at the lower left side of the exterior of the light shielding box 1. A workpiece 23 to be inspected that passes the inspection falls from the light shielding box 1 and enters the genuine bin 15, and a workpiece 23 to be inspected that fails the inspection is pushed out of the light shielding box 1 and falls into the defective bin 14.

[0025] The top plate of the shading box 1 is provided with an inlet, and the bottom plate and the left side plate are provided with an outlet respectively. The inlet and the two outlets are shielded from light by shading cloth. The genuine product bin 15 is placed directly below the bottom outlet, and the defective product bin 14 is placed directly below the outlet on the left side plate. Each shading cloth is divided into two pieces, one piece is equipped with a magnet 2, and the other piece is equipped with an iron block 5. When the shading cloth blocks the inlet or outlet, the magnet 2 and the iron block 5 attract each other, so that the shading cloth blocks the light. When the inlet and outlet are opened, the magnet 2 and the iron block 5 are temporarily separated. Specifically, the first shading cloth 8 is connected at the inlet, and the first shading cloth 8 is divided into a first shading cloth front monomer 801 fixedly connected to the shading box 1 and a first shading cloth rear monomer 802. The second shading cloth 13 is connected at the outlet of the left side plate, and the second shading cloth 13 is divided into a second shading cloth upper monomer 1301 fixedly connected to the shading box 1 and a second shading cloth lower monomer 1302. Several magnets 2 are fixed to the side edges of the first shading cloth front monomer 801 and the second shading cloth upper monomer 1301, and several iron blocks 5 are fixed to the side edges of the first shading cloth rear monomer 802 and the second shading cloth lower monomer 1302. A third shading cloth 16 is arranged at the bottom outlet, and the structure of the third shading cloth 16 is the same as that of the first shading cloth 8.

[0026] When the workpiece 23 to be inspected is placed into the light shielding box 1 through the top entrance, the left monomer 801 of the first light shielding cloth and the right monomer 802 of the first light shielding cloth are manually separated. After the workpiece 23 to be inspected is placed, the magnet 2 and the iron block 5 on the first light shielding cloth 8 attract each other so that the side edges of the front monomer 801 of the first light shielding cloth and the rear monomer 802 of the first light shielding cloth are in contact, so that the top entrance of the light shielding box 1 is restored to a closed state. When the workpiece 23 to be inspected that does not meet the coaxial relationship requirements passes through the left side plate exit, the upper monomer 1301 of the second light shielding cloth and the lower monomer 1302 of the second light shielding cloth are separated. After the workpiece 23 to be inspected passes through, the magnet 2 and the iron block 5 on the second light shielding cloth 13 attract each other so that the side edges of the upper monomer 1301 of the second light shielding cloth and the lower monomer 1302 of the second light shielding cloth are in contact, so that the left side plate exit is restored to a closed state. Similarly, after the workpiece 23 to be inspected that meets the coaxial relationship requirements passes through the bottom exit, the magnet 2 and the iron block 5 on the third light shielding cloth 16 attract each other so that the bottom exit is restored to a closed state.

[0027] The attraction between the magnet 2 and the iron block 5 is smaller than the weight of the workpiece 23 to be inspected. Thus, when the workpiece 23 to be inspected falls, the magnet 2 and the iron block 5 on the third shading cloth 16 at the bottom outlet are separated under the gravity of the workpiece 23 to be inspected.

[0028] In the light shielding box 1, a first conveyor belt 21 and a second conveyor belt 11 are provided in parallel with each other, and the second conveyor belt 11 and the first conveyor belt 21 are arranged on the left and the right with an interval therebetween.

[0029] The lower end of the first conveyor belt 21 is wound around the first conveyor belt driving shaft 17, and the upper end of the first conveyor belt 21 is wound around the first conveyor belt driven shaft 22. The lower end of the second conveyor belt 11 is wound around the second conveyor belt driving shaft 12, and the upper end of the second conveyor belt 11 is wound around the second conveyor belt driven shaft 9.

[0030] The four shafts, namely, the first conveyor belt driving shaft 17, the first conveyor belt driven shaft 22, the second conveyor belt driving shaft 12 and the second conveyor belt driven shaft 9, are all arranged horizontally in the front-to-back direction and are connected to the front and rear side plates of the light-shielding box 1 through bearings. One end of the first conveyor belt driving shaft 17 extends out of the side plate of the light-shielding box 1 and is coaxially fixedly connected to the output shaft of the first servo motor 3 arranged horizontally in the front-to-back direction. One end of the second conveyor belt driving shaft 12 extends out of the side plate of the light-shielding box 1 and is coaxially fixedly connected to the output shaft of the second servo motor 7 arranged horizontally in the front-to-back direction. The first servo motor 3 drives the first conveyor belt driving shaft 17 to rotate, and the second servo motor 7 drives the second conveyor belt driving shaft 12 to rotate. The motor housing of the first servo motor 3 is fixedly connected to the outer surface of the side plate of the light-shielding box 1 through the first servo motor mounting plate 4, and the motor housing of the second servo motor 7 is fixedly connected to the outer surface of the side plate of the light-shielding box 1 through the second servo motor mounting plate 6. Figure 2It is shown that the front ends of the first conveyor belt driving shaft 17 and the second conveyor belt driving shaft 12 extend out of the front side plate of the light shielding box 1 and are respectively fixedly connected to the first servo motor 3 and the second servo motor 7, and the first servo motor mounting plate 4 and the second servo motor mounting plate 6 are fixedly connected to the outer surface of the front side plate of the light shielding box 1.

[0031] The first conveyor belt 21 and the second conveyor belt 11 move in opposite directions. The first conveyor belt 21 drives the workpiece 23 to move downward, and the second conveyor belt 11 drives the photosensitive plate 10 to move upward on the side adjacent to the workpiece 23 to move upward.

[0032] A photosensitive plate 10 is fixedly connected to the middle of the outer surface of the second conveyor belt 11 in the front-to-back direction. The photosensitive plate 10 is a closed ellipse, which goes around the second conveyor belt 11, fits with the outer surface of the second conveyor belt 11, and is perpendicular to the outer surface of the second conveyor belt 11 and rotates synchronously with the second conveyor belt 11.

[0033] A plurality of support plates 20 are fixedly connected at equal intervals around the outer surface of the first conveyor belt 21, and the support plates 20 are perpendicular to the outer surface of the first conveyor belt 21. The support plate 20 is U-shaped, and the U-shaped bottom of the support plate 20 is fixedly connected to the first conveyor belt 21. The support plate 20 is used to support the U-shaped workpiece 23 to be inspected, and the workpiece 23 to be inspected is placed horizontally on the support plate 20. The two side plates of the U-shaped support plate 20 are arranged front and back, and the two side plates just support the front side plate 2302 and the rear side plate 2301 of the workpiece 23 to be inspected, that is, the front side plate 2302 and the rear side plate 2301 are located directly above the two side plates of the U-shaped support plate 20. The two side edges of the U-shaped support plate 20 are preferably made into an L shape, so that the workpiece 23 to be inspected can be positioned. When the support plate 20 faces the second conveyor belt 11 and the photosensitive plate 10, it is just in a horizontal state, and at this time, the U-shaped openings of the support plate 20 and the workpiece 23 to be inspected face the second conveyor belt 11 and the photosensitive plate 10. The photosensitive plate 10 extends to the right in the middle of the U-shaped opening, shielding the workpiece 23 to be inspected in the front-to-back direction. The front and rear axle holes 2304 and 2303 are at equal distances from the photosensitive plate 10 .

[0034] The thickness of the photosensitive plate 10 in the front-to-back direction is much smaller than the front-to-back distance of the U-shaped opening of the workpiece 23 to be inspected, and the width of the photosensitive plate 10 in the left-to-right direction is sufficient to cover the front shaft hole 2304 and the rear shaft hole 2303. Photosensitive resin is coated on the front and rear surfaces of the photosensitive plate 10, so that it will immediately cause a polymerization reaction under the irradiation of light, and the photosensitive resin in the dark will remain in its original state.

[0035] The left-right distance between the first conveyor belt 21 and the second conveyor belt 11 is greater than the left-right length of the workpiece 23 to be inspected after being placed, so that the workpiece 23 to be inspected does not interfere with the second conveyor belt 11.

[0036] Each support plate 20 has a common through hole at its U-shaped bottom and at the connection with the first conveyor belt 21. A cylinder 19 is provided inside the first conveyor belt 21 and at the same height as the left side plate outlet of the light shielding box 1. The cylinder body of the cylinder 19 is fixed on the cylinder mounting plate 18, which is fixed on the rear side plate inside the light shielding box 1. The cylinder 19 is at the same height as the left side plate outlet of the light shielding box 1. The output rod of the cylinder 19 faces the middle of the left side plate outlet of the light shielding box 1. When the common through hole on the support plate 20 and the first conveyor belt 21 moves to the same height as the output rod of the cylinder 19, the output rod of the cylinder 19 moves to the left and extends out of the common through hole, pushing the unqualified workpiece 23 to be inspected on the support plate 20 to the left side plate outlet of the light shielding box 1, so as to remove the workpiece 23 to be inspected whose coaxial relationship does not meet the requirements. The output rod of the cylinder 19 is spaced from the inner surface of the first conveyor belt 21 in the retracted state, and does not affect the movement of the first conveyor belt 21.

[0037] A first light source 27 is arranged on the front side plate inside the light shielding box 1, and a first camera 25 is arranged at a certain distance above the first light source 27. A second light source 26 is arranged at a corresponding position at the same height opposite to the first light source 27 on the rear side plate inside the light shielding box 1. The positions of the first light source 27 and the second light source 26 are opposite to the front axle hole 2304 and the rear axle hole 2303 of the workpiece 23 to be inspected. A second camera 24 is arranged on the rear side plate inside the light shielding box 1 at the same height opposite to the first camera 25, and a first position sensor 28 is arranged at the same height as the first light source 27 and the second light source 26. A second position sensor 29 is arranged at the exit position of the left side plate of the light shielding box 1.

[0038] The vertical distance between the two upper and lower adjacent support plates 20 on the first conveyor belt 21 is greater than the distance between the first light source 27 and the first camera 25 or greater than the vertical distance between the second light source 26 and the second camera 24. When the two sides of the U-shape of the support plate 20 are L-shaped, the support plate 20 can position the workpiece 23 to be inspected. The upper ends of the two sides are lower than the lowest ends of the front axle hole 2304 and the rear axle hole 2303 of the workpiece 23 to be inspected, ensuring that the support plate 20 does not block the light emitted by the first light source 27 from passing through the front axle hole 2304 of the workpiece 23 to be inspected, and the light emitted by the second light source 26 from passing through the rear axle hole 2303.

[0039] The vertical distance between the first light source 27 and the first camera 25 is greater than the vertical height of the rear side plate 2301 or the front side plate 2302 of the workpiece 23 to be inspected, and the second camera 24 and the second light source 26 are on the same straight line in the vertical direction. The vertical distance between the second light source 26 and the second camera 24 is equal to the vertical distance between the first light source 27 and the first camera 25. The first light source 27 and the second light source 26 are at the same height and are arranged symmetrically front and back about the photosensitive board 10, and the first camera 25 and the second camera 24 are at the same height and are arranged symmetrically front and back about the photosensitive board 10. Both the first light source 27 and the second light source 26 are linear lights, and the luminous range is slightly larger than the area of ​​the rear axle hole 2303 or the front axle hole 2304 of the workpiece 23 to be inspected. The first light source 27 passes through the front axle hole 2304 from the front and illuminates the front surface of the photosensitive board 10, and the second light source 26 passes through the rear axle hole 2303 from the back and illuminates the rear surface of the photosensitive board 10, and two circular patterns are formed in the areas illuminated by light on the front and rear surfaces of the photosensitive board 10.

[0040] The first camera 25 and the second camera 24 are connected to the image processing unit 30 via signal lines, and the output end of the image processing unit 30 is connected to the control unit 31 via signal lines. The first servo motor 3, the second servo motor 7, the cylinder 19, the first position sensor 28, the second position sensor 29, the first light source 27, and the second light source 26 are connected to the control unit 31 via corresponding signal lines or control lines. The image processing unit 30 and the control unit 31 are arranged outside the light shielding box 1.

[0041] See also Figure 1-5 When the coaxial relationship quick inspection fixture based on photosensitive materials described in the present invention is working, in the initial state, the output rod of the cylinder 19 is in a retracted state, the first conveyor belt 21 and the second conveyor belt 11 are both in a stationary state, the corresponding magnets 2 and iron blocks 5 on the first shading cloth 8, the second shading cloth 13 and the third shading cloth 16 are in a mutually attracted state, and the first shading cloth 8, the second shading cloth 13 and the third shading cloth 16 are all in a closed state.

[0042] The control unit 31 controls the first servo motor 3 and the second servo motor 7 to start working at the same time. The first servo motor 3 drives the first conveyor belt driving shaft 17 to rotate and drives the first conveyor belt 21 to rotate around the first conveyor belt driving shaft 17 and the first conveyor belt driven shaft 22. The support plate 20 moves with the first conveyor belt 21. The second servo motor 7 drives the second conveyor belt driving shaft 12 to rotate and drives the second conveyor belt 11 to rotate around the second conveyor belt driving shaft 12 and the second conveyor belt driven shaft 9. The photosensitive plate 10 is located on the second conveyor belt 11 and rotates with the second conveyor belt 11, so that the movement directions of the first conveyor belt 21 and the second conveyor belt 11 are opposite.

[0043] The first shading cloth 8 at the entrance is manually separated to be in an open state. When the first conveyor belt 21 drives the support plate 20 near the photosensitive plate 10 to move to the uppermost end and is in a horizontal state, the workpiece 23 to be inspected is placed on the uppermost support plate 20, so that the front side plate 2302 and the rear side plate 2301 of the workpiece 23 to be inspected are in contact with the two side plates of the support plate 20 without gaps, and the positions of the front shaft hole 2304 and the rear shaft hole 2303 are respectively located on the two side plates of the support plate 20, so that the U-shaped bottom of the workpiece 23 to be inspected is in contact with the U-shaped bottom of the support plate 20, so that the workpiece 23 to be inspected can be positioned. After the workpiece 23 to be inspected is placed, the magnet 2 and the iron block 5 located on the first shading cloth 8 are attracted to each other, and the top entrance of the shading box 1 returns to a closed state.

[0044] The first conveyor belt 21 drives the workpiece 23 to be inspected near the photosensitive plate 10 to move downward. At the same time, the photosensitive plate 10 moves upward on the side near the workpiece 23 to be inspected. When the front axle hole 2304 and the rear axle hole 2303 of the workpiece 23 to be inspected are at the same height as the first light source 27 and the second light source 26, the first position sensor 28 is triggered. The first position sensor 28 detects the position of the workpiece 23 to be inspected and transmits the detection signal to the control unit 31. The control unit 31 controls the first servo motor 3 and the second servo motor 7 to stop working, and the corresponding first conveyor belt 21 and the second conveyor belt 11 both stop working, so that the workpiece 23 to be inspected and the photosensitive plate 10 are in a stationary state.

[0045] Then, the control unit 31 controls the first light source 27 and the second light source 26 to start emitting light. The first light source 27 shines on the front axle hole 2304 from the front side of the workpiece 23 to be inspected, and the second light source 26 shines on the rear axle hole 2303 from the rear side. In this way, light passes through the front axle hole 2304 and the fork rear axle hole 2303 from both sides and shines on the front and back surfaces of the photosensitive plate 10. The photosensitive resin coated on the front and back surfaces of the photosensitive plate 10 will immediately cause a polymerization reaction under the irradiation of the light source, while the photosensitive resin in the dark will remain intact, forming a circular pattern on the front and back surfaces of the photosensitive plate 10.

[0046] The control unit 31 controls the first camera 25 and the second camera 24 to start working at the same time. The first camera 25 photographs the circular pattern on the front surface of the photosensitive plate 10, and the second camera 24 photographs the circular pattern on the rear surface of the photosensitive plate 10, and sends the pattern information to the image processing unit 30. The image processing unit 30 calculates the center coordinates of the two circles, obtains the coaxial relationship between the rear axle hole 2303 and the front axle hole 2304, and determines whether the measured coaxial relationship meets the tolerance requirements.

[0047] When the control unit 31 determines that the coaxial relationship does not meet the tolerance requirement, the control unit 31 controls the first servo motor 3 and the second servo motor 7 to start working at the same time, driving the workpiece 23 to be inspected to move downward and driving the photosensitive plate 10 to rotate. When the workpiece 23 to be inspected and the left side plate outlet of the light shielding box 1 are at the same height, the second position sensor 29 is triggered. The second position sensor 29 detects the position of the workpiece 23 to be inspected and sends a signal to the control unit 31. The control unit 31 issues an instruction to control the first servo motor 3 and the second servo motor 7 to stop working, so that the workpiece 23 to be inspected and the photosensitive plate 10 are both in a static state. Then, the control unit 31 controls the cylinder 19 to start working, and the output rod of the cylinder 19 passes through the common through hole on the support plate 20 and the first conveyor belt 21 to the left, and then pushes the workpiece 23 to be inspected. Under the thrust of the output rod of the cylinder 19, the second light shielding cloth 13 is separated, and the workpiece 23 to be inspected is pushed out through the left side plate outlet of the light shielding box 1 and falls into the defective bin 14. After the workpiece 23 to be inspected is pushed out, the magnet 2 and the iron block 5 on the second shading cloth 13 attract each other, so that the second shading cloth 13 closes the left side plate outlet of the shading box 1 .

[0048] On the contrary, when the control unit 31 determines that the coaxial relationship meets the tolerance requirements, the control unit 31 issues a command to control the first servo motor 3 and the second servo motor 7 to start working at the same time, the first servo motor 3 drives the first conveyor belt driving shaft 17 to rotate, and the support plate 20 rotates with the first conveyor belt 21, driving the workpiece 23 to be inspected to move downward. When the support plate 20 on which the workpiece 23 to be inspected is placed rotates to a vertical state, the workpiece 23 to be inspected, whose coaxial relationship meets the requirements, separates the third shading cloth 16 under the action of its own gravity, and falls into the genuine warehouse 15 through the bottom outlet of the shading box 1. After the workpiece 23 to be inspected passes through, the magnet 2 and the iron block 5 on the third shading cloth 16 attract each other, so that the bottom outlet of the shading box 1 returns to a closed state.

[0049] The second servo motor 7 continues to drive the second conveyor belt driving shaft 12 to rotate and drives the second conveyor belt 11 to rotate around the second conveyor belt driving shaft 12 and the second conveyor belt driven shaft 9. The photosensitive plate 10 is located on the second conveyor belt 11 and rotates with the second conveyor belt 11. This cycle is repeated to detect the next workpiece 23 to be inspected.

Claims

1. A coaxial relationship quick inspection fixture based on photosensitive materials, wherein the top plate of the light shielding box (1) is provided with an inlet, the bottom plate and the left side plate are provided with an outlet respectively, a defective product bin (14) is placed at the lower left side of the outside, a defective product bin (14) is placed directly below the outlet on the left side plate, and a genuine product bin (15) is placed directly below the outlet on the bottom plate, wherein the features are: A first conveyor belt (21) and a second conveyor belt (11) are provided in the light shielding box (1) and are arranged parallel to each other and spaced apart from each other on the left and the right. The output shaft of a first servo motor (3) arranged horizontally in the front and rear is coaxially fixedly connected to the first conveyor belt driving shaft (17). The lower end of the first conveyor belt (21) is wound around the first conveyor belt driving shaft (17), and the upper end is wound around the first conveyor belt driven shaft (22). The output shaft of a second servo motor (7) arranged horizontally in the front and rear is coaxially fixedly connected to the second conveyor belt driving shaft (12). The lower end of the second conveyor belt (11) is wound around the second conveyor belt driving shaft (12), and the upper end is wound around the second conveyor belt driven shaft (9). The second conveyor belt (11 ) is fixedly connected to a photosensitive plate (10) in the middle of the outer surface of the second conveyor belt (11); the photosensitive plate (10) is perpendicular to the outer surface of the second conveyor belt (11); a plurality of U-shaped support plates (20) for supporting the workpiece to be inspected are fixedly connected at equal intervals around the outer surface of the first conveyor belt (21); the two side plates of the U-shape are arranged front and back, the support plate (20) and the outer surface of the first conveyor belt (21) are perpendicular, the two axial holes of the workpiece to be inspected are respectively located on the two side plates of the U-shape of the support plate (20), the photosensitive plate (10) extends to the right in the middle of the U-shaped opening, covering the two axial holes, and the two axial holes are equidistant from the front to the back of the photosensitive plate (10); each support plate (20) A common through hole is formed at the U-shaped bottom and at the connection with the first conveyor belt (21); a cylinder (19) is arranged at the same height as the outlet at the left side plate, and the output rod of the cylinder (19) faces the outlet at the left side plate; a first light source (27) is arranged on the front side plate inside the light shielding box (1); a first camera (25) is arranged directly above the first light source (27); a second light source (26) is arranged on the rear side plate inside the light shielding box (1); the first light source (27) and the second light source (26) are symmetrical about the photosensitive plate (10); the first camera (25) and the second camera (24) are symmetrical about the photosensitive plate (10); and the first light source (27) and the second light source (26) are symmetrical about the photosensitive plate (10); A first position sensor (28) is arranged at the same height as the first light source (27) and the second light source (26), and a second position sensor (29) is arranged at the exit position of the left side plate; the first camera (25) and the second camera (24) are connected to the image processing unit (30) via signal lines, and the output end of the image processing unit (30) is connected to the control unit (31) via signal lines; the first servo motor (3), the second servo motor (7), the cylinder (19), the first position sensor (28), the second position sensor (29), the first light source (27), and the second light source (26) are connected to the control unit (31) via corresponding signal lines or control lines.

2. According to claim 1, a coaxial relationship quick detection fixture based on photosensitive materials is characterized by: A shading cloth is provided at the entrance and exit of the shading box (1), each shading cloth is divided into two pieces, one piece is provided with a magnet (2), and the other piece is provided with an iron block (5), and the magnet (2) and the iron block (5) are attracted to each other so that the shading cloth blocks light.

3. The coaxial relationship quick detection fixture based on photosensitive materials according to claim 2 is characterized by: The attraction force between the magnet (2) and the iron block (5) is smaller than the weight of the workpiece to be inspected.

4. The coaxial relationship quick detection fixture based on photosensitive materials according to claim 1 is characterized by: The motor housing of the first servo motor (3) is fixedly connected to the outer surface of the side plate of the light shielding box (1) via a first servo motor mounting plate (4), and the motor housing of the second servo motor (7) is fixedly connected to the outer surface of the side plate of the light shielding box (1) via a second servo motor mounting plate (6).

5. The coaxial relationship quick detection fixture based on photosensitive material according to claim 1 is characterized by: The thickness of the photosensitive plate (10) in the front-to-back direction is smaller than the front-to-back opening distance of the U-shaped opening of the workpiece (23) to be inspected, and photosensitive resin is coated on both the front and back surfaces of the photosensitive plate (10).

6. The coaxial relationship quick detection fixture based on photosensitive material according to claim 1 is characterized by: The left-right distance between the first conveyor belt (21) and the second conveyor belt (11) is greater than the left-right length of the workpiece (23) to be inspected after it is placed.

7. The coaxial relationship quick detection fixture based on photosensitive material according to claim 1 is characterized by: The vertical distance between two upper and lower adjacent support plates (20) on the first conveyor belt (21) is greater than the distance between the first light source (27) and the first camera (25) or greater than the vertical distance between the second light source (26) and the second camera (24), and the upper ends of the two U-shaped side edges of the support plate (20) are lower than the lowest ends of the two axial holes of the workpiece to be inspected.

8. The coaxial relationship quick detection fixture based on photosensitive material according to claim 1 is characterized by: The U-shaped side plates of the support plate (20) are both L-shaped, supporting the front side plate and the rear side plate of the workpiece to be inspected, and each of the front side plate and the rear side plate of the workpiece to be inspected has an axial hole.

9. A method for detecting a coaxial relationship rapid detection fixture based on photosensitive materials as claimed in claim 1, characterized in that The following steps are involved: Step A: The control unit (31) controls the first servo motor (3) and the second servo motor (7) to work simultaneously, so that the first conveyor belt (21) and the second conveyor belt (11) move in opposite directions, the support plate (20) moves along with the first conveyor belt (21), and the photosensitive plate (10) rotates along with the second conveyor belt (11); Step B: placing the workpiece to be inspected on the uppermost support plate (20) from the entrance, the first conveyor belt (21) drives the workpiece to be inspected near the photosensitive plate (10) to move downward, and when the first position sensor (28) detects that the two axial holes of the workpiece to be inspected are at the same height as the first light source (27) and the second light source (26), the control unit (31) controls the first servo motor (3) and the second servo motor (7) to stop working; Step C: the control unit (31) controls the first light source (27) to illuminate the front axial hole of the two axial holes from the front side of the workpiece to be inspected, and the second light source (26) to illuminate the rear axial hole from the rear side, so that a circular pattern is formed on the front and rear surfaces of the photosensitive plate (10); Step D: The control unit (31) controls the first camera (25) to photograph the circular pattern on the front surface of the photosensitive plate (10), and the second camera (24) to photograph the circular pattern on the rear surface of the photosensitive plate (10). The image processing unit (30) calculates the center coordinates of the two circles and determines whether the coaxial relationship of the two circles meets the tolerance requirement: Step E: The control unit (31) controls the first servo motor (3) and the second servo motor (7) to work again. When the coaxial relationship determined by the control unit (31) does not meet the tolerance requirement, and the second position sensor (29) detects that the workpiece to be inspected moves to the same height as the exit of the left side plate of the light shielding box (1), the first servo motor (3) and the second servo motor (7) stop working, and the control unit (31) controls the output rod of the cylinder (19) to push the workpiece to be inspected to the left through the common through hole and make it fall into the defective bin (14); conversely, when the coaxial relationship meets the tolerance requirement, the support plate (20) on which the workpiece to be inspected is placed rotates to a vertical state, and the workpiece to be inspected falls from the bottom plate exit into the genuine bin (15) under the action of gravity.

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