Tempered glass waveform degree detection device and detection method thereof

Abstract

The invention discloses a tempered glass waveform degree detection device which comprises a conveying device, a light source and an area array CCD camera, the light source and the area array CCD camera are sequentially arranged along the conveying path of the conveying device, and the conveying device is used for conveying tempered glass to be detected through conveying rollers; the light source is located above the conveying device, and a row of round holes evenly distributed at intervals are formed in the bottom of the light source. The light source is used for providing illumination for tempered glass to be detected and forming a round bright spot image on the tempered glass to be detected; the area array CCD camera is located above the conveying device and is used for collecting a round bright spot image on the tempered glass to be detected and recording the deviation change form of the position of the round bright spot; the light source and the area array CCD camera are located on the left side and the right side of tempered glass to be detected respectively. The invention further discloses a detection method of the tempered glass waveform degree detection device. According to the invention, the waveform degree of the toughened glass is detected through a non-contact detection method, the detection precision is high, and the detection result is accurate and reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of glass detection, and in particular relates to a tempered glass waveform detection device and a detection method thereof. Background Art

[0002] At present, with the wide application of tempered glass in the construction, automobile, furniture, decoration, home appliances and other industries as well as in daily life, the market demand for tempered glass is increasing, and the requirements for the quality of tempered glass are becoming more and more stringent. During the production process of tempered glass, due to the uneven temperature control in the heat treatment step, the thickness tolerance of the original glass and the influence of the equipment roller, the final product will have local bending, also known as local wave. This defect will cause the glass to have an uneven appearance and optical distortion, affecting the overall quality of the tempered glass. In order to produce tempered glass products with excellent wave degree, in addition to controlling the wave through process control, monitoring and measuring the wave is also an important control method.

[0003] Article 5.4 of the national standard "Safety Glass for Buildings Part 2: Tempered Glass" GB 15763.2-2005 clearly stipulates: "The curvature of flat tempered glass should not exceed 0.3% when it is bowed and should not exceed 0.2% when it is wavy." Article 6.4 of the standard clearly states the curvature measurement method as follows: "Put the sample at room temperature for more than 4 hours, stand it vertically during measurement, and place two pads at 1 / 4 of the length below its long side... When measuring local waveforms, use a ruler or metal wire to measure along the 25mm direction parallel to the edge of the glass, with a measuring length of 300mm. Use a feeler gauge to measure the height of the trough or peak, and divide it by 300mm to express the curvature of the waveform as a percentage."

[0004] The existing measurement methods use rulers and feeler gauges, which have high requirements for operators and are greatly affected by subjective factors. The testers have inconsistent understandings of the test standards, resulting in differences in measurement results and inability to achieve unified standards. Manual inspections can easily miss areas with smaller waveforms, resulting in missed inspections, poor detection results, and a large workload. Contact measurements can easily damage the surface of tempered glass. In the existing technology, most tests are conducted on the size of the waveform in the flow direction of the glass, while the size of the waveform in the direction perpendicular to the flow is ignored. Since the bending direction and size of the waveform of tempered glass are complex and changeable, it is difficult to measure accurately. Summary of the invention

[0005] In order to solve the above problems, the object of the present invention is to provide a tempered glass corrugation detection device and a detection method thereof.

[0006] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0007] A tempered glass corrugation detection device comprises a conveying device, a light source and an array CCD camera sequentially arranged along a conveying path of the conveying device, wherein:

[0008] The conveying device is used to convey the tempered glass to be inspected through a conveying roller;

[0009] The light source is located above the conveying device, with an angle of 45° with the plane of the tempered glass to be inspected, and a row of circular holes evenly spaced are provided at the bottom of the light source; the light source is used to provide illumination for the tempered glass to be inspected, and form a circular bright spot image on the tempered glass to be inspected;

[0010] The area array CCD camera is located above the conveying device, with an angle of 45° with the plane of the tempered glass to be tested, and is used to collect the circular bright spot image on the tempered glass to be tested and record the offset change of the position of the circular bright spot;

[0011] The light source and the area array CCD camera are respectively located on the left and right sides of the tempered glass to be detected.

[0012] Furthermore, the length of the light source and the number of circular holes provided at the bottom of the light source match the width of the transmission roller.

[0013] Furthermore, the diameter of the circular hole at the bottom of the light source is 25-30 mm, the distance between the centers of two adjacent circular holes is 35-45 mm, and the distance between two adjacent circular holes is 10-15 mm.

[0014] A detection method for a tempered glass corrugation detection device comprises the following steps:

[0015] S1. Place the tempered glass to be tested on the multiple conveying rollers of the conveying device, and convey it from left to right under the action of the conveying device; divide the tempered glass to be tested into several sections along the length direction according to the diameter of the circular hole opened at the bottom of the light source;

[0016] S2, the first section of the tempered glass to be tested arrives at the testing position, and multiple light beams emitted by the light source through a row of circular holes at the bottom are used as incident light. The incident light covers the width range of the tempered glass to be tested, and multiple light beams are incident from the air at 45° to M1 to M2 on the upper surface of the tempered glass to be tested. k The reflection occurs at the point, and multiple reflected lights are imaged on the chip of the area array CCD camera m1~m k After the incident light source is refracted by the upper surface of the tempered glass to be tested, multiple refracted lights intersect with the lower surface of the tempered glass to be tested at points N1 to N k Points are reflected by the lower surface of the tempered glass to be tested and refracted by the upper surface, and finally imaged on q1~q on the chip of the area array CCD camera. k point;

[0017] According to the Fresnel formula and geometric relationship, the relationship between the thickness d of the tempered glass to be tested and the center distance l on the area array CCD camera is obtained as follows:

[0018]

[0019] Where u is the object distance of the imaging system; f is the focal length of the imaging lens; n1 is the refractive index of air; n2 is the refractive index of the tempered glass to be tested; d is the thickness of the tempered glass to be tested, d includes d1~d k ; l includes l1~l k , l1~l k They are m1~m on the area array CCD camera respectively. k Points and corresponding q1~q k The distance between the points, i.e. l1 = m1-q1, l2 = m2-q2, ..., l k =m k -q k , represents the distance between the centers of two circles after each light beam of the light source is reflected by the upper and lower surfaces of the tempered glass to be detected; k represents the number of circular holes on the light source, and the number is related to the width of the conveyor roller;

[0020] The thickness change formula is:

[0021] Δd=d i -d α

[0022] Among them, d i Refers to the actual tempered glass thickness at the i-th position to be tested; d α is the theoretical thickness of the tempered glass to be tested, d α is a known value;

[0023] S3, by recording the degree of deviation of the central feature points of the reflected light spots on the upper and lower surfaces of the tempered glass to be tested, the relationship between the two center distances representing the degree of deviation and the thickness of the tempered glass to be tested is calculated, that is, the change in the center distance between the two points reflects the change in the thickness of the glass at the corresponding position, and the depth change of the waveform of the first section of the tempered glass to be tested is directly detected through the thickness change;

[0024] S4. Repeat the operations of steps S2 to S3 for several times, and directly detect the depth change of the waveform of the second section to the last section of the tempered glass to be tested through the thickness change.

[0025] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages:

[0026] The tempered glass corrugation detection device has a simple structure, is easy to operate, is not easily affected by ambient light, detects the corrugation of the tempered glass by a non-contact detection method, has high detection accuracy, good practicability, and accurate and reliable detection results, and has good promotion and application value.

[0027] The detection method of the tempered glass corrugation detection device measures the corrugation of the tempered glass in a vertical flow direction in a non-contact manner; uses the optical reflection of a light source on the tempered glass surface to calculate the relationship between the offset degree of the center distance of two circular light spots and the thickness; reflects the regularity between the corrugations of the corresponding positions of the tempered glass through the thickness change of each area on the tempered glass surface, and presents a waveform curve of the entire tempered glass surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of a device for detecting the corrugation of tempered glass according to the present invention;

[0029] Figure 2 It is a working principle diagram of the tempered glass waveform detection device of the present invention;

[0030] Figure 3 It is a diagram of the center distance taken by the area array CCD camera in one embodiment of the tempered glass waveform detection device of the present invention;

[0031] In the figure: 1 - light source; 2 - area array CCD camera; 3 - tempered glass to be tested; 4 - conveyor roller; 5 - circular hole. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0033] like Figure 1 , 2 As shown in , 3, the tempered glass waveform detection device comprises a conveying device, a light source 1 and an array CCD camera 2 which are sequentially arranged along the conveying path of the conveying device, wherein:

[0034] The conveying device is used to convey the tempered glass 3 to be inspected through the conveying roller 4;

[0035] The light source 1 is located above the conveying device, with an angle of 45° with the plane of the tempered glass 3 to be detected, and a row of circular holes 5 with uniform spacing are provided at the bottom of the light source; the light source is used to provide illumination for the tempered glass to be detected, and form a circular bright spot image on the tempered glass to be detected;

[0036] The area array CCD camera 2 is located above the conveying device, with an angle of 45° with the plane of the tempered glass 3 to be detected, and is used to collect the circular bright spot image on the tempered glass to be detected and record the displacement change of the position of the circular bright spot;

[0037] The light source and the area array CCD camera are respectively located on the left and right sides of the tempered glass to be detected.

[0038] The length of the light source and the number of circular holes provided at the bottom of the light source match the width of the transmission roller.

[0039] Preferably, the diameter of the circular hole at the bottom of the light source is 25-30 mm, the distance between the centers of two adjacent circular holes is 35-45 mm, and the distance between two adjacent circular holes is 10-15 mm.

[0040] The above-mentioned detection method of the tempered glass corrugation detection device comprises the following steps:

[0041] S1, placing the tempered glass 3 to be tested on the multiple conveying rollers 4 of the conveying device, and conveying it along the conveying direction at a certain speed under the action of the conveying device; dividing the tempered glass to be tested into several sections along the length direction according to the diameter of the circular hole 5 opened at the bottom of the light source 1;

[0042] S2, the first section of the tempered glass to be tested arrives at the testing position, and multiple light beams emitted by the light source through a row of circular holes at the bottom are used as incident light. The incident light covers the width range of the tempered glass to be tested, and multiple light beams are incident from the air at 45° to M1 to M2 on the upper surface of the tempered glass to be tested. k The reflection occurs at the point, and multiple reflected lights are imaged on the chip m1~m k After the incident light source is refracted by the upper surface of the tempered glass to be tested, multiple refracted lights intersect with the lower surface of the tempered glass to be tested at points N1 to N k Points are reflected by the lower surface of the tempered glass to be tested and refracted by the upper surface, and finally imaged on q1~q on the chip of the area array CCD camera. k point;

[0043] According to the Fresnel formula and geometric relationship, the relationship between the thickness d of the tempered glass to be tested and the center distance l on the area array CCD camera is obtained as follows:

[0044]

[0045] Where u is the object distance of the imaging system; f is the focal length of the imaging lens; n1 is the refractive index of air; n2 is the refractive index of the tempered glass to be tested; d is the thickness of the tempered glass to be tested, d includes d1~d k ; l includes l1~l k , l1~l k They are m1~m on the area array CCD camera respectively. k Points and corresponding q1~q kThe distance between the points, i.e. l1 = m1-q1, l2 = m2-q2, ..., l k =m k -q k , represents the distance between the centers of two circles after each light beam of the light source is reflected by the upper and lower surfaces of the tempered glass to be detected; k represents the number of circular holes on the light source, and the number is related to the width of the conveyor roller;

[0046] Specifically:

[0047]

[0048] The thickness change formula is:

[0049] Δd=d i -d α

[0050] Among them, d i Refers to the actual glass thickness at the i-th position to be detected; d α is the theoretical thickness of the glass to be tested, d α is known data, generally provided by glass manufacturers. For example, if the theoretical thickness of the glass to be tested is 5 mm, then d α =5mm;

[0051] S3, by recording the degree of deviation of the central feature points of the reflected light spots on the upper and lower surfaces of the tempered glass to be tested, the relationship between the two center distances representing the degree of deviation and the thickness of the tempered glass to be tested is calculated, that is, the change in the center distance between the two points reflects the change in the thickness of the glass at the corresponding position, and the depth change of the waveform of the first section of the tempered glass to be tested is directly detected through the thickness change;

[0052] S4. Repeat the operations of steps S2 to S3 for several times, and directly detect the depth change of the waveform of the second section to the last section of the tempered glass to be tested through the thickness change.

[0053] The detection method of the tempered glass waveform detection device of the present invention is as follows: as the tempered glass to be detected moves on the multiple conveying rollers of the conveying device, the area array CCD camera starts the image shooting function at a preset interval time, collects the circular bright spot image on the tempered glass to be detected, and records the offset change form of the position of the circular bright spot.

[0054] The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Without departing from the spirit and scope of the present invention, all equivalent changes and modifications made within the scope of the patent application of the present invention shall fall within the scope of patent protection of the present invention.

Claims

1. A tempered glass corrugation detection device, Its characteristics are: It includes a conveying device, a light source and a surface array CCD camera arranged in sequence along the conveying path of the conveying device, wherein: The conveying device is used to convey the tempered glass to be inspected through a conveying roller; The light source is located above the conveying device, with an angle of 45° with the plane of the tempered glass to be inspected, and a row of circular holes evenly spaced are provided at the bottom of the light source; the light source is used to provide illumination for the tempered glass to be inspected, and form a circular bright spot image on the tempered glass to be inspected; The area array CCD camera is located above the conveying device, with an angle of 45° with the plane of the tempered glass to be tested, and is used to collect the circular bright spot image on the tempered glass to be tested and record the offset change of the position of the circular bright spot; The light source and the area array CCD camera are respectively located on the left and right sides of the tempered glass to be detected.

2. The tempered glass corrugation detection device according to claim 1, Its characteristics are: The length of the light source and the number of circular holes opened at the bottom of the light source match the width of the transmission roller.

3. The tempered glass corrugation detection device according to claim 1 or 2, Its characteristics are: The diameter of the circular hole at the bottom of the light source is 25-30 mm, the distance between the centers of two adjacent circular holes is 35-45 mm, and the distance between two adjacent circular holes is 10-15 mm.

4. A detection method for the tempered glass corrugation detection device according to any one of claims 1 to 3, Its characteristics are: It includes the following steps: S1. Place the tempered glass to be tested on the multiple conveying rollers of the conveying device, and convey it from left to right under the action of the conveying device; divide the tempered glass to be tested into several sections along the length direction according to the diameter of the circular hole opened at the bottom of the light source; S2. The first section of the tempered glass to be tested arrives at the testing position. The light source emits multiple light beams through a row of circular holes at the bottom as incident light. The incident light covers the width range of the tempered glass to be tested. Multiple light beams are incident from the air at 45° to the M on the upper surface of the tempered glass to be tested. 1 ~M k The points are reflected, and multiple reflected lights are imaged on the chip of the area array CCD camera. 1 ~m k After the incident light source is refracted by the upper surface of the tempered glass to be tested, multiple refracted lights intersect with the lower surface of the tempered glass to be tested at point N 1 ~N k The point is reflected by the lower surface of the tempered glass to be tested and refracted by the upper surface, and finally imaged on the chip of the area array CCD camera. 1 ~q k point; According to the Fresnel formula and geometric relationship, the relationship between the thickness d of the tempered glass to be tested and the center distance l on the area array CCD camera is obtained as follows: Where u is the object distance of the imaging system; f is the focal length of the imaging lens; n 1 is the refractive index of air; n 2 is the refractive index of the tempered glass to be tested; d is the thickness of the tempered glass to be tested, d includes d 1 ~d k ; l includes l 1 ~l k , l 1 ~l k are m on the area array CCD camera 1 ~m k Points and corresponding q 1 ~q k The distance between the points, i.e. l 1 =m 1 -q 1 , l 2 =m 2 -q 2 ,......,l k =m k -q k , represents the distance between the centers of two circles after each light beam of the light source is reflected by the upper and lower surfaces of the tempered glass to be detected; k represents the number of circular holes on the light source, and the number is related to the width of the conveyor roller; The thickness change formula is: Δd=d i -d α Among them, d i Refers to the actual tempered glass thickness at the i-th position to be tested; d α is the theoretical thickness of the tempered glass to be tested, d α is a known value; S3, by recording the degree of deviation of the central feature points of the reflected light spots on the upper and lower surfaces of the tempered glass to be tested, the relationship between the two center distances representing the degree of deviation and the thickness of the tempered glass to be tested is calculated, that is, the change in the center distance between the two points reflects the change in the thickness of the glass at the corresponding position, and the depth change of the waveform of the first section of the tempered glass to be tested is directly detected through the thickness change; S4. Repeat the operations of steps S2 to S3 for several times, and directly detect the depth change of the waveform of the second section to the last section of the tempered glass to be tested through the thickness change.

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