A vertical detection method for curvature of optical fiber preform and a special detection device thereof

Abstract

The present invention provides a vertical detection method for the curvature of an optical fiber preform, which can solve the problem of low detection accuracy of the existing horizontal detection method. The preform is firstly set upright on a test tower; a visual detection mechanism scans the preform from one end to the other end along the axial direction of the preform, and the center point of the preform obtained at each scanning position is recorded as a test point; the two test points at the first and last ends of the scan are connected into a test straight line, and the vertical orthogonal distances from all other test points to the test straight line are calculated, and the maximum distance value obtained therein is recorded as N1; the preform is rotated around the axial direction by a certain angle in sequence, and the above steps are repeated to obtain s maximum distance values, which are recorded as N2, N3...Ns in sequence; the sizes of N1, N2, N3...Ns are compared, and the maximum value thereof is recorded as Nmax, which is the maximum curvature value of the preform; according to the testable length L of the preform, the curvature of the preform is obtained = Nmax / L.

Description

Technical Field

[0001] The invention relates to the field of processing and detecting optical fiber preforms, and in particular to a vertical detection method for the curvature of an optical fiber preform and a special detection device thereof. Background Art

[0002] In this field, the curvature of the rod body of the optical fiber preform is an important parameter for quality control of the optical fiber preform; the existing preform curvature test adopts a horizontal detection method, which is to place the preform to be tested horizontally on a detection bracket, drive the preform to rotate and simultaneously contact the dial indicator contact with the detection surface of the preform, record the count of the dial indicator during the preform rotation, and half of the difference f between the maximum count and the minimum count is the curvature value N of the preform at this cross-sectional position. According to this step, the curvature values ​​at multiple cross-sectional positions of the preform are detected and the maximum value N is taken. max , and then according to the length L of the preform to be tested, the curvature of the preform can be obtained. However, in the existing horizontal detection method, due to the influence of its own weight, when the preform lies horizontally on the detection bracket, the preform itself is bent, which will inevitably affect the detection accuracy of the curvature of the preform; in addition, the detection accuracy of the existing detection method is often affected by the non-roundness of the optical fiber preform itself; therefore, the existing method cannot meet the detection accuracy requirements. Summary of the invention

[0003] In view of the above problems, the present invention provides a vertical detection method for the curvature of an optical fiber preform, which can solve the problem that the existing horizontal detection method is affected by the bending of the preform itself due to its own weight, thereby affecting the detection accuracy, and can also solve the problem that the existing method is affected by the non-circularity of the outer circumference of the optical fiber preform itself and has low accuracy. To this end, the present invention also provides a dedicated detection device.

[0004] A vertical detection method for curvature of an optical fiber preform, characterized in that it comprises the following steps:

[0005] Step (1), placing the preform rod upright on a test tower;

[0006] Step (2), the visual inspection mechanism scans the preform rod from one end to the other end along the axial direction of the preform rod, and records the center point of the preform rod obtained at each scanning position as a test point, wherein the test points at the scanning head end and the scanning tail end are recorded as end test points, and all test points between the two end test points are recorded as middle test points;

[0007] Step (3), connecting the two end test points into a test straight line, drawing an orthogonal line perpendicular to the test straight line through each of the intermediate test points and calculating the distance between the intermediate test point and the foot of the perpendicular, and recording the maximum distance value obtained as N1;

[0008] Step (4), rotating the preform rod s times around the axis and each rotation angle is 180° / s, and after each rotation, steps (1) to (3) are repeated to obtain s maximum distance values, which are recorded as N2, N3, ..., Ns in sequence;

[0009] Step (5), comparing the values ​​of N1, N2, N3, ..., Ns, taking the maximum value thereof as Nmax, which is the maximum bending value of the preform;

[0010] Step (6), based on the testable length L of the preform rod, the curvature of the preform rod is obtained as Nmax / L.

[0011] Furthermore, the visual inspection mechanism includes a laser scanning diameter gauge and a visual camera assembly, wherein the laser scanning diameter gauge detects the diameter D of the optical fiber preform at each scanning position, and the visual camera assembly takes a picture of the optical fiber preform at the scanning position, and determines the center point of the optical fiber preform at the scanning position based on the measured diameter D of the optical fiber preform at each scanning position and the photographic image information of the scanning position.

[0012] Furthermore, in step (2), the visual inspection mechanism scans along the axial direction of the preform from one end to the other end at an equal interval x, with an interval of 0 <x≤L / 2。

[0013] Furthermore, all the test points obtained in step (2) are first merged into a curve from the head end to the tail end, and then step (3) is performed.

[0014] The present invention also provides a special detection device for the curvature of an optical fiber preform, which is characterized in that: it comprises

[0015] A test tower arranged vertically;

[0016] A clamp mechanism, used for vertically clamping the preform to be tested on the test tower;

[0017] A lifting mechanism, used to control the vertical lifting and lowering movement of the visual inspection mechanism so that the visual inspection mechanism can scan and inspect the curvature of the preform to be inspected clamped by the clamp mechanism;

[0018] A servo rotation control mechanism, used to control the axial rotation of the preform to be inspected;

[0019] And a control center, the visual detection mechanism, the lifting mechanism, and the servo rotation control mechanism are electrically connected to the control center.

[0020] Furthermore, the clamp mechanism includes an upper jacket and a lower clamp, the test tower is provided with an upper bracket and a lower bracket, the servo rotation control mechanism and the upper jacket are both provided on the upper bracket, and the power output end of the servo rotation control mechanism is axially connected to the upper jacket, the lower clamp can be opened and closed on the lower bracket, the clamping center of the upper jacket is concentrically arranged with the clamping center of the lower clamp, the visual inspection mechanism is installed on the test tower through the lifting mechanism and can be vertically lifted and lowered between the upper bracket and the lower bracket under the drive of the lifting mechanism, and the top and bottom ends of the preform rod to be inspected can be clamped by the upper jacket and the lower clamp respectively.

[0021] Furthermore, the lifting mechanism includes a lifting base plate and a first lifting servo power assembly, the visual inspection mechanism is fixedly mounted on the lifting base plate, lifting guide rails are respectively installed on the two side columns of the test tower, the lateral sides of the lifting base plate are respectively slidably connected to the lifting guide rails, and the test tower is also provided with a vertically extending lifting transmission rack, the first lifting servo power assembly is installed on the lifting base plate, and a first driving gear is installed on the power output end of the first lifting servo power assembly, the first driving gear is meshed and transmission-connected with the lifting transmission rack, and the first lifting servo power assembly is electrically connected to the control center.

[0022] Furthermore, the upper bracket includes an upper base plate, the lateral sides of which are slidably connected to the lifting guide rails, and a second lifting servo power assembly is also provided on the upper base plate. A second driving gear is installed on the power output end of the second lifting servo assembly, and the second driving gear is meshed and transmission-connected with the lifting transmission rack, and the second lifting servo power assembly is electrically connected to the control center.

[0023] Furthermore, the upper bracket also includes a support base vertically connected to the upper base plate, the servo rotation control mechanism is vertically arranged on the support base and the power output end of the servo rotation control mechanism passes through the base plate of the support base and is axially connected to the upper sleeve; the servo rotation control mechanism includes a rotation servo power assembly and a transmission assembly, the transmission assembly includes a rotating shaft and a rotating seat, the rotating seat is vertically installed on the support base, the rotation servo power assembly is arranged on the rotating seat through a mounting seat, the mounting seat and the rotating seat both have a hollow inner cavity and the two hollow inner cavities are vertically connected, the rotating shaft passes through the hollow inner cavity of the rotating seat and its top end extends into the hollow inner cavity of the mounting seat, is axially connected to the power output end of the rotation servo power assembly through a coupling, and the bottom end passes through the support base and is connected to the upper jacket.

[0024] Furthermore, a weighing assembly is arranged between the rotating seat and the supporting seat, and the weighing assembly includes a weighing transition plate and a weighing sensor. The weighing transition plate is supported between the top surface of the supporting seat and the bottom surface of the rotating seat, and the weighing sensor is arranged on the outer peripheral side of the rotating axis within the internal space formed by the top surface of the supporting seat, the bottom surface of the rotating seat, and the weighing transition plate. The weighing sensor is electrically connected to the control center.

[0025] In a further solution, the bottom end of the rotating shaft is axially connected to the upper jacket via a floating connection assembly, and the floating connection assembly includes a floating joint and a transition shaft. The transition shaft is fixed to the bottom end surface of the rotating shaft, and the transition shaft is axially connected to the upper jacket via the floating joint.

[0026] Furthermore, the visual inspection mechanism includes a laser scanning diameter gauge and a visual camera assembly, and the laser scanning diameter measurement and visual camera assembly are both electrically connected to the control center. The visual camera assembly is installed on the lifting base plate through a first inspection base, and the laser scanning diameter gauge is installed on the lifting base plate through a second inspection base, and the laser scanning diameter gauge is located below the visual camera assembly.

[0027] Furthermore, the visual camera assembly includes a camera, a lens, a detection light source and a protective cover, the protective cover is fixed on the first detection base, the camera, lens, and detection light source are arranged along a horizontal straight line, and the detection light source and lens are arranged in the protective cover.

[0028] According to a further preferred solution, the visual camera assembly also includes a movable protective cover, which is sleeved on the outside of the protective cover, a transverse horizontal cylinder is provided on the first detection base, a transverse horizontal guide rail is provided on the protective cover, the mobile protective cover is slidably connected to the transverse horizontal guide rail, the guide rod end of the transverse horizontal cylinder is connected to the guide rod connecting piece through a centering joint, the guide rod connecting piece is fixedly mounted on the mobile protective cover, a U-shaped cavity extending horizontally along the transverse direction is provided on the top plate of the mobile protective cover, and the transverse horizontal cylinder is electrically connected to the control center.

[0029] According to a further solution, an anti-collision sensor is arranged on the top of the lifting base plate, and an anti-collision limit plate and a limit switch are arranged on the bottom of the upper base plate corresponding to the position of the anti-collision sensor, and the anti-collision sensor and the limit switch are electrically connected to the control center.

[0030] A further preferred solution is that a tank chain upper fixing plate and a tank chain lower fixing plate are respectively installed on the same lateral side of the upper base plate and the lifting base plate, and the tank chain upper fixing plate and the tank chain lower fixing plate are respectively connected to the two ends of the tank chain.

[0031] Furthermore, the lower clamp includes a clamp base plate, a pneumatic drive mechanism and two clamping blocks. The clamp base plate is fixedly mounted on the test tower and is located below the two lifting guide rails. The pneumatic drive mechanism is installed on the clamp base plate. The pneumatic drive mechanism is electrically connected to the control center. Both clamping blocks have a clamping portion for clamping the preform rod. The pneumatic drive mechanism is a bidirectional double-rod cylinder. The two clamping blocks are respectively connected to the two guide rod end plates of the bidirectional double-rod cylinder, and the clamping portions of the two clamping blocks are symmetrical and arranged facing each other.

[0032] The beneficial effect of the vertical detection method of the curvature of the optical fiber preform of the present invention is that: the optical fiber preform is vertically erected on the test tower and the optical fiber preform is always kept in an upright state during the entire detection process, thereby effectively avoiding the problem that the optical fiber preform is slightly bent due to its own weight and thus affects the accuracy of curvature detection in the existing horizontal detection method; at the same time, it adopts a visual detection mechanism, especially a combination of a laser scanning diameter gauge and a visual camera component to perform curvature detection, so it can effectively avoid the problem that the detection accuracy is affected by the non-roundness of the outer circle of the optical fiber preform itself in the existing method. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the main structure of a vertical detection device for the curvature of an optical fiber preform in the present invention;

[0034] Figure 2 It is a schematic side view of the structure of a vertical detection device for the curvature of an optical fiber preform in the present invention;

[0035] Figure 3 It is a schematic diagram of the main view assembly structure of the upper bracket, the upper jacket installed on the upper bracket, and the servo rotation control mechanism in the special detection device of the present invention;

[0036] Figure 4 for Figure 3 AA structural diagram;

[0037] Figure 5 for Figure 3 A side view schematic diagram of the structure;

[0038] Figure 6 for Figure 3 Schematic diagram of the three-dimensional structure;

[0039] Figure 7 It is a schematic diagram of the main view assembly structure of the lower bracket and the visual inspection mechanism installed on the lower bracket in the special inspection device of the present invention;

[0040] Figure 8 for Figure 7 A schematic diagram of the structure viewed from above;

[0041] Fig. 9 for Figure 7 A schematic diagram of a three-dimensional structure in a first viewing direction;

[0042] Fig.10 for Figure 7 A schematic diagram of a three-dimensional structure in a second viewing direction;

[0043] Fig.11 It is a schematic diagram of the structure of the lower clamp in the special detection device of the present invention from a top view;

[0044] Fig.12 for Fig.11 Schematic diagram of the three-dimensional structure.

[0045] Reference numerals:

[0046] 10-test tower, 11-upper bracket, 111-upper base plate, 112-support base, 12-lower bracket;

[0047] 21-upper clamp, 22-lower clamp, 221-pneumatic drive mechanism, 222a-clamping block, 222b-clamping block, 223-clamping part, 224-clamping bottom plate, 23-floating joint, 24-transition shaft;

[0048] 31-lifting base plate, 32-first lifting servo power assembly, 321-first lifting servo motor, 322-first reducer, 33-lifting guide rail, 34-lifting transmission rack, 35-first driving gear, 36-second lifting servo power assembly, 361-second lifting servo motor, 362-second reducer, 37-second driving gear, 38-anti-collision sensor, 39-anti-collision transition plate, 310-anti-collision limit plate, 311-limit switch, 312-tank chain upper fixing plate, 313-tank chain lower fixing plate, 314-tank chain;

[0049] 40- visual inspection mechanism, 41- laser scanning diameter gauge, 421- camera, 422- lens, 423- protective cover, 424- movable protective cover, 424a- U-shaped cavity, 425- transverse horizontal cylinder, 426- transverse horizontal guide rail, 427- centering joint, 428- guide rod connector, 43- first inspection base, 44- second inspection base;

[0050] 50-servo rotation control mechanism, 51-rotation servo power assembly, 511-mounting seat, 512-rotation servo motor, 513-third speed reducer, 52-transmission assembly, 521-rotation shaft, 522-rotation seat, 523-coupling, 524-bearing, 53-weighing assembly, 531-weighing transition plate, 532-weighing sensor;

[0051] 60 - Optical fiber preform to be detected. Specific implementation manner

[0052] A vertical detection method for the curvature of an optical fiber preform provided by the present invention includes the following steps:

[0053] Step (1), vertically arrange the preform on the test tower.

[0054] Step (2), the visual detection mechanism scans the preform along the axial direction of the preform from one end to the other end, and records the center point of the preform obtained at each scanning position as a test point, where the test points at the scanning start end and the scanning end are recorded as end test points, and all the test points between the two end test points are recorded as intermediate test points.

[0055] Step (3), connect the two end test points into a test straight line, draw an orthogonal line perpendicular to the test straight line through each intermediate test point and calculate the distance between the intermediate test point and the foot of the perpendicular, and record the maximum distance value obtained as N1.

[0056] Step (4), rotate the preform around the axial direction s times in the same direction, each time the rotation angle is 180° / s, and after each rotation, repeat steps (1) to (3) and obtain s maximum distance values, which are recorded as N2, N3... Ns in sequence.

[0057] Step (5), compare the magnitudes of N1, N2, N3... Ns, and take the maximum value among them as Nmax, which is the maximum bending value of the preform.

[0058] Step (6), according to the testable length L of the preform, obtain the curvature of the preform = Nmax / L.

[0059] The visual detection mechanism includes a laser scanning diameter gauge and a visual camera assembly. In the above step (2), the laser scanning diameter gauge detects the diameter D of the optical fiber preform at each scanning position, and at the same time the visual camera assembly takes a picture of the optical fiber preform at this scanning position, and determines the center point position (i.e., the test point position) of the optical fiber preform at the scanning position according to the measured diameter D of the optical fiber preform at each scanning position and the picture information at this scanning position.

[0060] In the above step (2), the visual detection mechanism scans along the axial direction of the preform at equal intervals x from one end to the other end, where 0 < x ≤ L / 2; in the actual detection process, the interval x is determined according to the length of the optical fiber preform, and the smaller the interval x, the higher the detection accuracy, but if the interval x is too small, it will also affect the detection efficiency, so it is particularly important to set a reasonable interval x; usually, the interval x is 90 mm or 100 mm.

[0061] According to a further preferred technical solution, the test points obtained in step (2) are firstly merged into a curve from the head end to the tail end, and then step (3) is performed.

[0062] In view of the above-mentioned optical fiber preform curvature detection method of the present invention, the present invention also provides an optical fiber preform curvature detection device. The following specifically describes the special detection device of the present invention in conjunction with the accompanying drawings, which includes:

[0063] A test tower 10 arranged vertically upright;

[0064] A clamp mechanism, used to clamp the preform to be tested vertically and upright on the test tower 10;

[0065] A lifting mechanism, used to control the vertical lifting and lowering movement of the visual inspection mechanism 40 so that the visual inspection mechanism 40 can scan and inspect the curvature of the preform to be inspected clamped by the clamp mechanism;

[0066] A servo rotation control mechanism 50, used to control the axial rotation of the preform to be inspected;

[0067] As well as a control center, the visual inspection mechanism 40, the lifting mechanism, and the servo rotation control mechanism 50 are electrically connected to the control center.

[0068] The clamp mechanism includes an upper jacket 21 and a lower clamp 22. The test tower 10 is provided with an upper bracket 11 and a lower bracket 12. The servo rotation control mechanism 50 and the upper jacket 21 are both provided on the upper bracket 11, and the power output end of the servo rotation control mechanism 50 is axially connected to the upper jacket 21. The lower clamp 22 can be opened and closed on the lower bracket 12. The clamping center of the upper jacket 21 is concentrically arranged with the clamping center of the lower clamp 22. The visual inspection mechanism 40 is installed on the test tower 10 through a lifting mechanism and can be vertically lifted and moved between the upper bracket 11 and the lower bracket 12. The top and bottom ends of the preform to be inspected can be clamped by the upper jacket 21 and the lower clamp 12 respectively. The clamp in the device of the present invention The tool mechanism adopts an integral upper jacket 21 structure and an openable and closable split lower clamp 22 structure, so that when the optical fiber preform needs to be axially rotated during the detection process, the openable and closable split lower clamp 22 can loosen the lower end of the optical fiber preform, and the servo rotation control mechanism 50 can directly drive the optical fiber preform to rotate through the upper jacket 21. After the optical fiber preform is rotated into place, the lower clamp 22 clamps its lower end again, that is, the visual inspection mechanism 40 can immediately perform the next round of visual scanning inspection on the optical fiber preform; such a setting can improve the detection speed on the one hand, and on the other hand, it can avoid the clamping positioning error caused by the need for secondary clamping of both ends of the optical fiber preform after rotation, and ensure the detection accuracy.

[0069] The lifting mechanism includes a lifting base plate 31 and a first lifting servo power assembly 32. The visual inspection mechanism 40 is installed on the lifting base plate 31. In this embodiment, the first lifting servo power assembly 32 includes a first lifting servo motor 321 and a first reducer 322. The visual inspection mechanism 40 is fixed on the lifting base plate 31. The columns on both sides of the test tower 10 are respectively installed with lifting guide rails 33. The lateral sides of the lifting base plate 31 are respectively slidably connected to the lifting guide rails 33. The test tower 10 is also provided with a vertically extending lifting transmission rack 34. The first reducer 322 of the first lifting servo power assembly 32 is installed on the lifting base plate 31. The power output end of the servo motor 321 is axially connected to the power input end of the first reducer 322. The power output end of the first reducer 322 passes through the lifting base plate 31 and is then installed with the first drive gear 35. The first drive gear 35 is meshed and connected to the lifting transmission rack 34. The first lifting servo power assembly 32 is electrically connected to the control center. Thus, the control center can control the action of the first lifting servo power assembly 32, so that the first lifting servo power assembly 32 drives the first drive gear 35 to move up and down along the lifting transmission rack 34, thereby driving the lifting base plate 31 on which the visual inspection mechanism 40 is installed to move vertically along the lifting guide rail 33.

[0070] The upper bracket 11 includes an upper base plate 111, and the lateral sides of the upper base plate 111 are slidably connected to the lifting guide rails 33. The upper base plate 111 is also provided with a second lifting servo power assembly 36. In this embodiment, the second lifting servo power assembly 36 includes a second lifting servo motor 361 and a second reducer 362. The power output end of the second lifting servo motor 361 is axially connected to the power input end of the second reducer 362. The second reducer 362 is installed on the upper base plate 111, and the power output end of the second reducer 362 passes through the upper base plate 111 and is then installed with a second driving gear 37. The second driving gear 37 is meshed and connected with the lifting transmission rack 34, and the second lifting servo power assembly 36 is electrically connected with the control center; therefore, under the driving and transmission action of the second lifting servo power assembly 36 and the second driving gear and the lifting transmission rack 34, the upper bracket 11 and the servo rotation control mechanism and the upper jacket 21 arranged on the upper bracket 11 can be moved vertically and linearly along the lifting guide rail 33 on the test tower 10 as a whole, so as to adapt to the detection and clamping requirements of optical fiber preform rods of different lengths, thereby greatly improving the versatility of the detection device of the present invention.

[0071] The upper bracket 11 also includes a support base 112 vertically connected to the upper base plate 111. Figure 4The servo rotation control mechanism 50 is vertically arranged on the support seat 112, and the power output end of the servo rotation control mechanism 50 passes through the bottom plate of the support seat 112 and is axially connected to the upper jacket 21; the servo rotation control mechanism 50 includes a rotation servo power assembly 51 and a transmission assembly 52, the transmission assembly 52 includes a rotating shaft 521 and a rotating seat 522, the rotating seat 522 is vertically installed on the support seat 112, the rotation servo power assembly 51 is arranged on the rotating seat 522 through the mounting seat 511, the mounting seat 511 and the rotating seat 522 both have a hollow inner cavity and the two hollow inner cavities are vertically connected, the rotating shaft 521 passes through the hollow inner cavity of the rotating seat 522 and its top end extends into the hollow inner cavity of the mounting seat 511, and is axially connected to the power output end of the rotation servo power assembly 51 through a coupling 523, and the bottom end passes through the support seat 112 and is connected to the upper jacket 21; in this embodiment, the rotation servo power assembly 51 includes a rotation servo motor 512 and a third reducer 513; Figure 4 In the embodiment, the rotating shaft 521 is rotatably supported in the hollow inner cavity of the rotating seat 522 through the bearing 524.

[0072] Furthermore, a weighing assembly 53 is also provided between the rotating seat 522 and the supporting seat 112, and the weighing assembly 53 includes a weighing transition plate 531 and a weighing sensor 532. The weighing transition plate 531 is supported between the top surface of the supporting seat 112 and the bottom surface of the rotating seat 522, and a weighing sensor 532 is provided on the outer peripheral side of the rotating shaft 521 located in the internal space formed by the top surface of the supporting seat 112, the bottom surface of the rotating seat 522, and the weighing transition plate 531; in this embodiment, four weighing sensors 532 are provided, and the four weighing sensors 532 are symmetrically arranged around the rotating shaft 521 in pairs. When the optical fiber preform is clamped on the test tower 10 by the upper sleeve 21 and the lower clamp 22, the force test analysis of the four weighing sensors 532 can quantitatively reflect whether the clamping of the optical fiber preform is stable and reliable, and thereby adjust the reliable clamping of the optical fiber preform, which can further ensure the accuracy of curvature detection.

[0073] In a further solution, the bottom end of the rotating shaft 521 is axially connected to the upper jacket 21 via a floating connection assembly, the floating connection assembly includes a floating joint 23 and a transition shaft 24, the transition shaft 24 is fixed to the bottom end surface of the rotating shaft 521, and the transition shaft 24 is axially connected to the upper jacket 21 via the floating joint 23; during the process of clamping the optical fiber preform to the test tower 10, the floating connection assembly can play a role in axial fine-tuning of the optical fiber preform, further ensuring the reliable clamping of the preform and ensuring the detection accuracy.

[0074] The visual inspection mechanism 40 includes a laser scanning diameter gauge 41 and a visual camera assembly. The visual camera assembly is installed on the lifting base plate 31 through a first inspection base 43. The laser scanning diameter gauge 41 is installed on the lifting base plate 31 through a second inspection base 44, and the laser scanning diameter gauge 41 is located below the visual camera assembly.

[0075] Among them, the visual camera assembly includes a camera 421, a lens 422, a detection light source and a protective cover 423. The protective cover 423 is fixed on the first detection base 43. The camera 421, the lens 422, and the detection light source are arranged along a horizontal straight line, and the detection light source and the lens 422 are arranged in the protective cover 423 (the detection light source is not shown in the accompanying drawings because it is blocked by the protective cover 423).

[0076] In a further preferred solution, the visual camera assembly also includes a mobile protective cover 424, which is sleeved on the outer side of the protective cover 423, a transverse horizontal cylinder 425 is provided on the first detection base 43, a transverse horizontal guide rail 426 is provided on the protective cover 423, the mobile protective cover 424 is slidably connected to the transverse horizontal guide rail 426, the guide rod end of the transverse horizontal cylinder 425 is connected to the guide rod connector 428 through a centering joint 427, the guide rod connector 428 is fixedly mounted on the mobile protective cover 424, the transverse horizontal cylinder 425 is electrically connected to the control center, and the mobile protective cover 424 A U-shaped cavity 424a extending horizontally in the transverse direction is provided on the top plate; after the optical fiber preform 60 to be detected is clamped to the test tower 10, the optical fiber preform to be detected should be in a state of penetrating the U-shaped cavity 424a of the movable protective cover 424, and the control center can control the movement of the transverse horizontal cylinder 425, so that the transverse horizontal cylinder 425 can drive the movable protective cover 424 to move horizontally along the transverse horizontal guide rail 426, so that the movable protective cover 424 can limit the optical fiber preform 60 to be detected to the effective shooting and framing range of the visual camera assembly and ensure that the light source is not affected by the external environment, thereby ensuring the detection accuracy.

[0077] In addition, an anti-collision sensor 38 is arranged on the top of the lifting base plate 31 through an anti-collision transition plate 39, and an anti-collision limit plate 310 and a limit switch 311 are arranged at the bottom of the upper base plate 111 corresponding to the position of the anti-collision sensor 38, and the anti-collision sensor 38 and the limit switch 311 are electrically connected to the control center; the setting of the anti-collision sensor 38 and the limit switch 311 can effectively prevent the visual inspection mechanism 40 from colliding with the upper bracket 11 during the vertical lifting movement driven by the first lifting servo power assembly 32, thereby avoiding damage to the high-precision visual inspection mechanism 50 due to collision impact, and effectively ensuring reliable detection of optical fiber preform rods.

[0078] In addition, a tank chain upper fixing plate 312 and a tank chain lower fixing plate 313 are respectively installed on the same lateral side of the upper base plate 111 and the lifting base plate 31, and the tank chain upper fixing plate 312 and the tank chain lower fixing plate 313 are respectively connected to the two ends of the tank chain 314; this arrangement can ensure the stability of the vertical lifting and moving of the visual inspection mechanism 40 driven by the lifting mechanism, thereby ensuring the inspection accuracy.

[0079] The lower fixture 22 includes a fixture base plate 224, a pneumatic drive mechanism and two clamping blocks 222a and 222b. The fixture base plate 224 is fixedly mounted on the test tower 10 and is located at the central position below the two lifting guide rails. The pneumatic drive mechanism is installed on the fixture base plate 224. The two clamping blocks 222a and 222b both have a clamping portion 223 for clamping the preform. The pneumatic drive mechanism is a bidirectional double-rod cylinder 221. The two clamping blocks 222a and 222b are respectively connected to the two guide rod end plates of the bidirectional double-rod cylinder 221, and the clamping portions 223 of the two clamping blocks 222a and 222b are symmetrical and arranged facing each other. The bidirectional double-rod cylinder 221 is electrically connected to the control center. Therefore, the bidirectional double-rod cylinder 221 can drive the two clamping blocks 222a and 222b to move toward or away from each other at the same time, thereby clamping or releasing the lower end of the optical fiber preform.

[0080] The above detailed description of the specific implementation of the present invention is only a preferred implementation of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A special detection device for a vertical detection method of curvature of an optical fiber preform, characterized in that: It includes a test tower arranged vertically upright; A clamp mechanism, used for vertically clamping the preform to be tested on the test tower; A lifting mechanism, used to control the vertical lifting and lowering movement of the visual inspection mechanism so that the visual inspection mechanism can scan and inspect the curvature of the preform to be inspected clamped by the clamp mechanism; A servo rotation control mechanism, used to control the axial rotation of the preform to be inspected; and a control center, the visual detection mechanism, the lifting mechanism, and the servo rotation control mechanism being electrically connected to the control center; The visual inspection mechanism includes a laser scanning diameter gauge and a visual camera assembly, wherein the laser scanning diameter gauge is used to detect the diameter D of the optical fiber preform at each scanning position, and the visual camera assembly takes a picture of the optical fiber preform at the scanning position; The clamp mechanism includes an upper jacket and a lower clamp, an upper bracket and a lower bracket are arranged on the test tower, the servo rotation control mechanism and the upper jacket are both arranged on the upper bracket, and the power output end of the servo rotation control mechanism is axially connected to the upper jacket, the lower clamp can be opened and closed on the lower bracket, the clamping center of the upper jacket is concentrically arranged with the clamping center of the lower clamp, the visual inspection mechanism is installed on the test tower through the lifting mechanism and can be vertically lifted and moved between the upper bracket and the lower bracket under the drive of the lifting mechanism, and the top and bottom ends of the preform rod to be inspected can be clamped by the upper jacket and the lower clamp respectively.

2. The dedicated detection device according to claim 1, characterized in that: The lifting mechanism includes a lifting base plate and a first lifting servo power assembly, the visual inspection mechanism is fixedly mounted on the lifting base plate, lifting guide rails are respectively installed on the two side columns of the test tower, the lateral sides of the lifting base plate are respectively slidably connected to the lifting guide rails, and a vertically extending lifting transmission rack is also provided on the test tower, the first lifting servo power assembly is installed on the lifting base plate, and a first driving gear is installed on the power output end of the first lifting servo power assembly, the first driving gear is meshed and transmission-connected with the lifting transmission rack, and the first lifting servo power assembly is electrically connected to the control center.

3. The dedicated detection device according to claim 2, characterized in that: The upper bracket includes an upper base plate, and the lateral sides of the upper base plate are slidably connected to the lifting guide rails. A second lifting servo power assembly is also arranged on the upper base plate. A second driving gear is installed on the power output end of the second lifting servo assembly. The second driving gear is meshed and transmission-connected with the lifting transmission rack. The second lifting servo power assembly is electrically connected to the control center.

4. The dedicated detection device according to claim 3, characterized in that: The upper bracket also includes a support base vertically connected to the upper base plate, the servo rotation control mechanism is vertically arranged on the support base and the power output end of the servo rotation control mechanism passes through the base plate of the support base and is axially connected to the upper sleeve; the servo rotation control mechanism includes a rotation servo power assembly and a transmission assembly, the transmission assembly includes a rotating shaft and a rotating seat, the rotating seat is vertically installed on the support base, the rotation servo power assembly is arranged on the rotating seat through a mounting seat, the mounting seat and the rotating seat both have a hollow inner cavity and the two hollow inner cavities are vertically connected, the rotating shaft passes through the hollow inner cavity of the rotating seat and its top end extends into the hollow inner cavity of the mounting seat, is axially connected to the power output end of the rotation servo power assembly through a coupling, and the bottom end passes through the support base and is connected to the upper jacket.

5. The dedicated detection device according to claim 4, characterized in that: A weighing assembly is also arranged between the rotating seat and the supporting seat, and the weighing assembly includes a weighing transition plate and a weighing sensor. The weighing transition plate is supported between the top surface of the supporting seat and the bottom surface of the rotating seat, and the weighing sensor is arranged on the outer peripheral side of the rotating shaft in the internal space formed by the top surface of the supporting seat, the bottom surface of the rotating seat, and the weighing transition plate. The weighing sensor is electrically connected to the control center.

6. The dedicated detection device according to claim 4, characterized in that: The bottom end of the rotating shaft is axially connected to the upper jacket via a floating connection assembly, and the floating connection assembly includes a floating joint and a transition shaft. The transition shaft is fixed to the bottom end surface of the rotating shaft, and the transition shaft is axially connected to the upper jacket via the floating joint.

7. The dedicated detection device according to claim 3, characterized in that: The visual inspection mechanism includes a laser scanning diameter gauge and a visual camera assembly, both of which are electrically connected to the control center. The visual camera assembly is installed on the lifting base plate through a first inspection base, and the laser scanning diameter gauge is installed on the lifting base plate through a second inspection base, and the laser scanning diameter gauge is located below the visual camera assembly.

8. The dedicated detection device according to claim 7, characterized in that: The visual camera assembly includes a camera, a lens, a detection light source and a protective cover, wherein the protective cover is fixed on the first detection base, and the camera, the lens, and the detection light source are arranged along a horizontal straight line, and the detection light source and the lens are arranged in the protective cover.

9. The dedicated detection device according to claim 7, characterized in that: The visual camera assembly also includes a movable protective cover, which is sleeved on the outer side of the protective cover. A transverse horizontal cylinder is provided on the first detection base, and a transverse horizontal guide rail is provided on the protective cover. The movable protective cover is slidably connected to the transverse horizontal guide rail. The guide rod end of the transverse horizontal cylinder is connected to the guide rod connector through a centering joint, and the guide rod connector is fixed on the movable protective cover. A U-shaped cavity extending horizontally in the transverse direction is provided on the top plate of the movable protective cover, and the transverse horizontal cylinder is electrically connected to the control center.

10. The dedicated detection device according to claim 7, characterized in that: An anti-collision sensor is arranged on the top of the lifting base plate, and an anti-collision limit plate and a limit switch are arranged on the bottom of the upper base plate corresponding to the position of the anti-collision sensor, and the anti-collision sensor and the limit switch are electrically connected to the control center; an upper fixing plate of a tank chain and a lower fixing plate of a tank chain are respectively installed on the same lateral side of the upper base plate and the lifting base plate, and the upper fixing plate of the tank chain and the lower fixing plate of the tank chain are respectively connected to the two ends of the tank chain.

11. The dedicated detection device according to claim 2, characterized in that: The lower clamp includes a clamp base plate, a pneumatic drive mechanism and two clamping blocks. The clamp base plate is fixedly mounted on the test tower and is located below the two lifting guide rails. The pneumatic drive mechanism is installed on the clamp base plate. The pneumatic drive mechanism is electrically connected to the control center. Both clamping blocks have a clamping portion for clamping the preform rod. The pneumatic drive mechanism is a bidirectional double-rod cylinder. The two clamping blocks are respectively connected to the two guide rod end plates of the bidirectional double-rod cylinder, and the clamping portions of the two clamping blocks are symmetrical and arranged facing each other.

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