High-precision optical detection device and method for deep hole internal detection

Abstract

The invention belongs to the technical field of deep hole measurement, and provides a high-precision optical detection device and method for deep hole internal detection, the device comprises a measurement probe and a calculation unit, the measurement probe is integrated with a laser transmitter, an optical system assembly, a reflector mechanism, a receiving lens module and a linear array CCD sensor; during measurement, a measuring probe is adapted according to a nominal aperture, and a push rod extends into a deep hole in a probing manner for measurement, and the method comprises the following steps: laser transmitters which are coaxially arranged in parallel vertically emit laser beams which are converged and collimated by an optical system assembly to the inner wall of the deep hole to be measured through a reflector mechanism, and the laser beams are focused through a receiving lens module after being subjected to diffuse reflection of the hole wall; and finally, the calculation unit calculates the aperture size by using the similar triangle principle. The device is compact in structure, high in anti-interference performance, wide in measuring range coverage range and capable of achieving non-contact micrometer-level real-time measurement of large-hole-depth through hole and blind hole parts.

Description

Technical Field

[0001] This invention belongs to the field of deep hole measurement technology, specifically relating to a high-precision optical inspection device and method for deep hole internal inspection. Background Technology

[0002] With the continuous advancement of industrial manufacturing technology, the requirements for product precision are becoming increasingly stringent. Among numerous precision parts, deep-hole parts have attracted much attention due to their complex machining process and stringent dimensional requirements. The machining and measurement of deep holes has always been one of the challenges in the field of mechanical manufacturing. The measurement of large and deep holes is far more difficult than that of shallow holes. This is not only because large and deep holes have small diameters and large depths, but also because the limitations of light and space inside them make traditional measurement methods difficult to implement.

[0003] Currently, deep hole measurements are generally performed using pedestal-mounted aperture gauges based on pneumatic, optical, or electric principles. However, while these instruments offer high accuracy, they suffer from complex structures, are highly susceptible to temperature variations, have low measurement efficiency, and incur high manufacturing and maintenance costs, making them unsuitable for outdoor environments and large-scale measurement tasks. Therefore, designing a compact, interference-resistant device and method capable of real-time and accurate measurement of both large and deep holes is of paramount importance.

[0004] Some existing technologies use a ring laser emitter to emit a ring laser beam. After being reflected by a rotating mirror, the laser beam first converges to a point and then diverges before being projected onto the inner wall of the deep hole to be measured, ultimately forming a ring-shaped aperture. An endoscope then captures an image of this ring-shaped aperture, and the point cloud coordinates of the deep hole in the workpiece are obtained through analytical calculations of the captured image. This invention converts changes in aperture into changes in spot size, allowing for the acquisition of edge information for the entire cross-section in a single image, significantly improving detection efficiency. However, the ring laser is susceptible to scattering during transmission, leading to blurred image edges and affecting measurement accuracy. Furthermore, point cloud calculations are required for each cross-section image, resulting in high data processing complexity.

[0005] Other existing technologies use a structure of a light-blocking plate and a light-transmitting plate to achieve pinhole imaging of the inner wall of a deep hole. The image is then displayed on a screen to observe the morphology of the inner wall and the width of the imaged light spot. Based on the image's spot width, precise values ​​for various parameters of the workpiece, such as the hole diameter, roundness, and cylindricity, are calculated. However, because this device relies on pinhole imaging, it requires a large-area illumination from the light source and that the diameters of the light-blocking and light-transmitting plates be very close to the diameter of the deep hole being measured. This significantly limits the device's measurement range, and the large-area illumination of the light source is highly susceptible to interference from external light.

[0006] In some existing technologies, measurements can be completed simply by inserting a reflector into a narrow space within the range where the device can receive the reflected light. This method solves the problem that most direct-fire laser triangulation devices cannot be inserted into narrow holes for measurement. However, the reflector in this device is separate from the other structures of the sensor, and only the reflector can be inserted into the hole during measurement. In addition, the sensor has a limited range, thus limiting the depth of deep holes that this device can measure.

[0007] In summary, although the above designs have greatly expanded the deep hole detection device, none of them can meet the requirements of high-precision real-time measurement under large hole depth conditions, as well as the universal detection requirements of compatible through holes and blind holes. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a high-precision optical inspection device and method for deep hole internal inspection, thereby resolving the issues in the prior art. The technical solution adopted by this invention is as follows: A high-precision optical inspection device for deep hole inspection includes: a measuring probe and a computing unit; the measuring probe is placed inside the deep hole of the workpiece to be measured during measurement. The measurement probe includes a laser emitter, optical system components, a reflector mechanism, a receiving lens module, and a linear CCD sensor; The optical system component is installed at the emitting end of the laser emitter. The laser beam emitted by the laser emitter is focused and collimated by the optical system component and then illuminates the reflector mechanism. The reflector mechanism is used to reflect the laser beam onto the inner wall of the deep hole of the workpiece to be measured, and the laser beam forms a reflected beam on the inner wall of the deep hole of the workpiece to be measured. The receiving lens module is used to receive the reflected beam and focus it onto the linear CCD sensor. The calculation unit is used to calculate the diameter of the deep hole in the workpiece to be tested based on the data from the linear CCD sensor.

[0009] Furthermore, the laser emitter, optical system components, reflector mechanism, receiving lens module, and linear CCD sensor are mounted on the housing body, and a transmission line is fixedly connected to the tail of the housing body, the transmission line being connected to the laser emitter.

[0010] Furthermore, the optical system components include a pinhole grating, a condenser lens, and a collimating lens arranged sequentially along the optical path transmission direction.

[0011] Furthermore, the reflector mechanism includes a reflector, a support plate, a universal joint, a gear set, a gear adjusting rod, a lead screw, a sliding column, and a locking plate; The reflector is fixed to the support plate, and three universal joints are installed at the bottom of the support plate. One of the universal joints is positioned lower and is fixedly connected to a sliding column by screws. The sliding column is movably connected to the clamping plate. The other two universal joints are positioned higher and are fixedly connected to corresponding lead screws by screws. The two lead screws pass through the clamping plate. The gear set includes a sun gear and planet gears; the sun gear is fixedly connected to the gear adjusting rod; the clamping plate is provided with a hole for the sun gear to pass through, so that the sun gear is located above or below the clamping plate; there are three planet gears, two of which are rotatably disposed on the bottom surface of the clamping plate and threaded onto two lead screws, and the other planet gear is rotatably disposed on the top surface of the clamping plate and threaded onto one of the lead screws; When the gear adjusting rod is in the lower position and rotates, it drives the sun gear to rotate, which in turn drives the two planetary gears to rotate, causing the two lead screws to produce radial displacement and push the sliding column to move back and forth, so as to realize the rotation of the reflector around the X direction; when the gear adjusting rod is raised to the upper position and rotates, it will drive the planetary gear on the upper side to rotate, which in turn drives the matching lead screw to move independently, so as to make the reflector rotate around the Y direction.

[0012] Furthermore, the card plate is mounted on the housing body by screws.

[0013] Furthermore, the receiving lens module includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a grating STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging surface IMA arranged sequentially along the optical path transmission direction. The first lens L1 has positive optical power, and the object side S1 of the first lens L1 is convex and the image side S2 is concave. The second lens L2 has positive optical power, and the object side S3 of the second lens L2 is convex, while the image side S4 is concave. The third lens L3 has positive optical power, the object side S5 of the third lens L3 is convex, the image side S6 is flat, and it is cemented with the fourth lens L4. The fourth lens L4 has negative optical power, and the image-side surface S7 of the fourth lens L4 is concave. The fifth lens L5 has negative optical power. The object side S8 of the fifth lens L5 is concave, and the image side S9 is flat. It is cemented with the sixth lens L6. The sixth lens L6 has positive optical power, and the image-side surface S10 of the sixth lens L6 is convex. The seventh lens L7 has positive optical power, and both the object side S11 and the image side S12 of the seventh lens L7 are convex surfaces.

[0014] Furthermore, the linear CCD sensor includes at least three rows of photosensitive units arranged sequentially. When the reflected laser beam is projected onto the linear CCD sensor, the photosensitive unit at the corresponding position transmits information to the shift register via the transfer grid. Then, the shift register transmits the information of the position of the light spot outward. After processing, the center position information of the light spot generated on the inner wall of the deep hole of the workpiece to be measured is obtained. Finally, based on the accurate distance value of the center position of the light spot from the reference origin, the value of the distance between the inner wall of the deep hole of the workpiece to be measured and the central axis is quickly calculated, which is used as the diameter of the deep hole of the workpiece to be measured.

[0015] A high-precision optical inspection method for deep hole internal inspection includes the following steps: Step 1: Place the measuring probe into the deep hole of the workpiece to be measured, rotate it around its own axis for one revolution to collect initial measurement information of the current cross section from multiple angles, and adjust the posture and position of the measuring probe synchronously based on the initial measurement information of multiple angles so that the central axis of the laser emitter coincides with the central axis of the deep hole of the workpiece to be measured, thus completing optical alignment; Step 2: Using a measurement probe that has already achieved optical alignment, acquire the laser beam spot position information in real time, extract the pixel offset of the spot center relative to the reference origin of the linear CCD sensor, and convert it into the actual physical distance. ; Step 3: Based on physical distance The hole diameter D at this cross-section of the deep hole in the workpiece under test is calculated. Step 4: Move the measuring probe axially by pushing the push rod, and repeat steps 2 to 3 to obtain the hole diameter of the deep hole cross section at different depths of the workpiece to be measured.

[0016] Furthermore, the calculation process in step three includes: Let A be the contact point between the laser beam and the inner wall of the deep hole in the workpiece under test, B be the contact point between the laser beam and the inner wall of the deep hole in the standard workpiece, O be the intersection point of the diffusely reflected laser beam (reflected from the hole wall) and the center of the main plane of the receiving lens module, and let denot the contact point between the diffusely reflected laser beam from the inner wall of the deep hole in the workpiece under test and the linear CCD sensor. The contact point between the laser beam reflected from the inner wall of the deep hole of the standard workpiece and the linear CCD sensor is denoted as... Point A is on line segment The projection of the point is point C. Point on line segment The projection on is a point The distance from the inner wall of the deep hole of the standard workpiece to the center of the horizontal laser beam is set as follows: The distance between A and B is The distance between BO is , The distance between them is , The relative distance between them is The angle between the diffusely reflected laser beam from the inner wall of the deep hole of the standard workpiece and the receiving plane of the linear CCD sensor is... The angle between the specularly reflected laser beam and the diffusely reflected laser beam from the inner wall of the deep hole of the standard workpiece is... ; according to Value calculated The value is then used to obtain the diameter D of the deep hole in the workpiece to be measured. The calculation process is as follows: Depend on We can obtain: ; The geometric relation is: , , , , , ; Substituting the geometric relation into equation (1) and simplifying, we get: ; Radius of the deep hole in the workpiece to be measured For the radius of the deep hole of the standard workpiece minus Then we have: ; When the inner wall of the deep hole in the workpiece to be tested is higher than that in the standard workpiece, the radius of the deep hole in the workpiece to be tested... for: ; The radius of the deep hole in the workpiece to be measured is: ; The diameter of the deep hole in the workpiece to be tested is: ; When the diameter of the deep hole in the workpiece to be tested is larger than the diameter of the deep hole in the standard workpiece, the formula (6) The symbol is , The symbol is When the diameter of the deep hole in the workpiece to be tested is smaller than the diameter of the deep hole in the standard workpiece, the formula (6) is as follows: The symbol is , The symbol is .

[0017] The present invention has the following beneficial effects: This invention uses an optical system to converge and collimate the laser beam output from a laser emitter. The beam is then redirected by a reflector mechanism to directly illuminate the inner wall of a deep hole in the workpiece. The diffusely reflected laser beam is focused by a receiving lens module onto a linear CCD sensor, and finally, the aperture size is calculated by a computing unit. The optical system improves the laser beam's directionality and signal-to-noise ratio through pre-collimation and filtering. The reflector mechanism employs dual-degree-of-freedom precision adjustment to compensate for assembly errors and ensure laser beam perpendicularity, while simultaneously ensuring the laser emitter is coaxially and parallelly arranged to reduce the device's radial dimensions. The receiving lens module efficiently converges the diffusely reflected laser beam, combined with… The linear CCD sensor reduces the amount of data processed while maintaining a high signal-to-noise ratio, laying the foundation for real-time, high-precision aperture calculation using triangulation. The CCD plate adjustment rod allows for fine-tuning of the linear CCD sensor's imaging surface, satisfying optimal imaging conditions where the vertical laser beam axis, the principal plane of the receiving lens module, and the imaging surface are conjugate, maximizing sensor resolution and improving detection sensitivity. The integrated design of the housing allows for the assembly of components such as the push rod, balancing compactness with the need for deep hole penetration of various sizes. Furthermore, the stepped range series of measurement probes broadens the measurement range while ensuring detection accuracy and sensitivity within each sub-range. In summary, this invention, through innovative design of optical modules and mechanical structures, achieves non-contact, real-time, high-precision measurement of large-diameter deep holes and blind holes, with detection accuracy reaching the micrometer level. This device features a compact structure, adjustable range, and strong anti-interference capabilities, effectively solving the problems of low accuracy, poor adaptability, and low efficiency in traditional deep hole detection, and has significant application value in the fields of precision manufacturing and testing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the optical system components in this invention; Figure 3 This is a schematic diagram of the reflector mechanism in this invention; Figure 4 This is a schematic diagram of the receiving lens module in this invention; Figure 5 This is a schematic diagram of the main body of the shell in this invention; Figure 6 This is a schematic diagram illustrating the measurement principle of the present invention; Figure 7 This is a schematic diagram of the linear CCD sensor structure in this invention; Explanation of reference numerals in the attached drawings: 1. Push rod; 2. Transmission line; 3. Laser emitter; 4. Optical system components: 401. Pinhole grating; 402. Condensing lens; 403. Collimating lens; 5. Reflector mechanism: 501. Reflector; 502. Support plate; 503. Universal joint; 504. Gear set; 505. Gear adjusting rod; 506. Lead screw; 507. Sliding column; 508. Screw; 509. Clamping plate; 6. Upper end cover of the housing; 7. Retaining ring; 8. Receiving lens module: L1. First lens; L2. Second lens; L3. Third lens; L4. Fourth lens; STO. Aperture; L5, Fifth Lens; L6, Sixth Lens; L7, Seventh Lens; IMA, Imaging Surface; 9, Linear CCD Sensor: 901, Transfer Grid; 902, Shift Register; 903, Photosensitive Unit; 10, Right End Cover; 11, CCD Plate Adjustment Rod; 12, Housing Body: 1201, Left End Cylindrical Thread; 1202, Horizontal Threaded Hole; 1203, Slide Groove; 1204, Groove; 1205, Radial Hole; 1206, Axial Groove; 1207, Through Radial Hole; 1208, Right End Cylindrical Thread; 13, Deep Hole of the Workpiece to be Measured; 14, Deep Hole of the Standard Workpiece. Detailed Implementation

[0019] The following will be described in conjunction with embodiments of the present invention. Figures 1-7 The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0020] like Figure 1 As shown, the present invention provides a high-precision optical inspection device for deep hole inspection, comprising: a measuring probe and a computing unit; the measuring probe is placed inside the deep hole 13 of the workpiece to be measured during measurement; The measurement probe includes a laser emitter 3, an optical system component 4, a reflector mechanism 5, a receiving lens module 8, and a linear CCD sensor 9; The laser emitter 3 is equipped with the optical system component 4 at its emitting end. The laser beam emitted by the laser emitter 3 is focused and collimated by the optical system component 4 and then illuminates the reflector mechanism 5. The reflector mechanism 5 is used to reflect the laser beam onto the inner wall surface of the deep hole 13 of the workpiece to be measured, and the laser beam forms a reflected beam on the inner wall surface of the deep hole 13 of the workpiece to be measured. The receiving lens module 8 is used to receive the reflected beam and focus it onto the linear CCD sensor 9. The push rod 1 is fixed to the measuring probe by a thread and is used to send the measuring probe into the deep hole 13 of the workpiece to be measured; The transmission line 2 is used to control the opening and closing of the laser emitter 3 and to transmit the data collected by the linear CCD sensor 9; the laser emitter 3 is threadedly mounted to the housing body 12, and its optical axis is parallel to the central axis of the housing body 12; the optical system component 4 is fixed to the light-emitting end of the laser emitter 3 and is used to converge and collimate the laser beam; the reflector mechanism 5 is fixed to the housing body 12 and is used to vertically reflect the incident laser beam to the inner wall of the deep hole 13 of the workpiece to be measured; the receiving lens module 8 is mounted to the upper end cover 6 of the housing through the retaining ring 7, and the upper end cover 6 of the housing is threadedly connected and fixed to the housing body 12 through the right end cover 10; the linear CCD sensor 9 is fixedly mounted on the housing body 12 by means of the CCD plate adjustment rod 11. During measurement, the laser beam emitted by the laser emitter 3 is converged and collimated by the optical system component 4, and then transmitted horizontally along the central axis of the deep hole 13 of the workpiece to be measured to the reflector mechanism 5. After being reflected by the reflector mechanism 5, the laser beam is vertically irradiated to the inner wall of the deep hole 13 of the workpiece to be measured. After being reflected by the inner wall of the deep hole 13 of the workpiece to be measured, the laser beam is focused by the receiving lens module 8 and finally received by the linear CCD sensor 9. The calculation unit is used to calculate the diameter of the deep hole 13 in the workpiece to be measured based on the information transmitted from the linear array CCD sensor 9 in the measuring probe.

[0021] like Figure 2 As shown, the optical system component 4 includes, in sequence along the optical path transmission direction, a pinhole grating 401, a condenser lens 402, and a collimating lens 403. The pinhole grating 401 is disposed at the light-emitting end of the laser emitter 3 and is used to perform spatial filtering on the emitted laser beam, filter out stray light, and limit the effective beam aperture. The condenser lens 402 is located behind the pinhole grating 401 and is used to converge the filtered laser beam. The collimating lens 403 is placed near the image-side focal point of the condenser lens 402 and is used to convert the converged laser beam from the condenser lens 402 into a parallel collimated laser beam that propagates along the central axis of the deep hole 13 of the workpiece to be measured, thereby improving the directionality of the laser beam and the stability of the ranging.

[0022] like Figure 3 As shown, the reflector mechanism 5 includes a reflector 501, a support plate 502, a universal joint 503, a gear set 504, a gear adjusting rod 505, a lead screw 506, a sliding column 507, and a clamping plate 509. The reflector 501 is fixed to the support plate 502. Three universal joints 503 are installed at the bottom of the support plate 502. One of the universal joints 503 is positioned lower and is fixedly connected to the slide column 507 by a screw 508. The slide column 507 is movably connected to the clamping plate 509. The other two universal joints 503 are positioned higher and are fixedly connected to the corresponding lead screws 506 by screws 508 respectively. The two lead screws 506 pass through the clamping plate 509 respectively. The gear set 504 includes a sun gear and planet gears; the sun gear is fixedly connected to the gear adjusting rod 505; the clamping plate 509 is provided with a hole for the sun gear to pass through, so that the sun gear is located above or below the clamping plate 509; three planet gears are provided, two of which are rotatably disposed on the bottom surface of the clamping plate 509 and threaded onto two lead screws 506, and the other planet gear is rotatably disposed on the top surface of the clamping plate 509 and threaded onto one of the lead screws 506; When the gear adjusting rod 505 is in the lower position and rotates, it drives the sun gear to rotate, which in turn drives the two planetary gears to rotate, causing the two lead screws 506 to generate radial displacement and push the sliding column 507 to move back and forth, so that the reflector 501 rotates around the X direction; when the gear adjusting rod 505 is raised to the upper position and rotates, it will drive the planetary gear 504 on the upper side to rotate, which in turn drives the matching lead screw 506 to move independently, so that the reflector 501 rotates around the Y direction.

[0023] like Figure 4 As shown, the receiving lens module 8 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a grating STO, a fifth lens L5, a sixth lens L6, a seventh lens L7, and an imaging plane IMA; wherein, the first lens L1 has positive optical power, the object-side surface S1 is convex, and the image-side surface S2 is concave; the second lens L2 has positive optical power, the object-side surface S3 is convex, and the image-side surface S4 is concave; the third lens L3 has positive optical power, the object-side surface S5 is convex, and the image-side surface S6 is flat, and is connected to the fourth lens L1. 4. Cementing; The fourth lens L4 has negative optical power, and its image-side surface S7 is concave; The fifth lens L5 has negative optical power, its object-side surface S8 is concave, and its image-side surface S9 is flat, and is cemented with the sixth lens L6; The sixth lens L6 has positive optical power, and its image-side surface S10 is convex; The seventh lens L7 has positive optical power, and both its object-side surface S11 and image-side surface S12 are convex; The receiving lens module 8 uses the different refractive abilities of different lenses to focus and transmit the laser beam, improving the intensity of the received light spot and the accuracy of the system. The relevant parameters of the receiving lens module 8 are shown in the table below:

[0024] like Figure 5As shown, the housing body 12 includes several functional structures. The left end cylindrical thread 1201 is used to achieve a rigid connection with the push rod 1; the horizontal threaded hole 1202 is used for the coaxial installation of the laser emitter 3; the slide groove 1203 is used to guide and limit the movement trajectory of the slide column 507; the groove 1204 is used to accommodate the gear set 504, and the radial hole 1205 in the groove 1204 is used to support and constrain the lead screw 506 and the gear adjusting rod 505; the axial groove 1206 arranged along the axial direction is used to install the linear array CCD sensor 9; the right end is provided with a through radial hole 1207 for supporting the CCD plate adjusting rod 11; the right end cylindrical thread 1208 is used to achieve a fixed connection between the upper end cover 6 of the housing and the housing body 12 by threading with the right end cover 10.

[0025] like Figure 6 As shown, the extensions of the vertical laser beam axis reflected by the reflector mechanism 5, the main plane of the receiving lens module 8, and the imaging plane of the linear CCD sensor 9 intersect at a point, which is used to make the laser beam spot form an optimal image on the linear CCD sensor 9, thereby improving the detection accuracy.

[0026] Furthermore, the diameter of the standard workpiece deep hole 14 is equal to the nominal diameter of the workpiece deep hole 13 to be tested.

[0027] Furthermore, the detection probe adopts a stepped range design scheme, which divides the entire measurement aperture range into multiple continuous sub-ranges. Each sub-range corresponds to a probe module with a specific reference radius. The probe modules are consistent in structure and have the same type of components. Only the reference radius is adapted to its respective range. In actual measurement, the probe with the corresponding range is selected for matching measurement based on the nominal aperture of the deep hole 13 of the workpiece to be measured, thereby achieving high-precision detection within the entire range.

[0028] like Figure 7 As shown, the linear CCD sensor 9 includes at least three rows of photosensitive units 903 arranged sequentially. When the diffuse laser beam is projected onto the linear CCD sensor 9, the photosensitive unit 903 at the corresponding position transmits information to the shift register 902 via the transfer grid 901. Then, the shift register 902 transmits the information of the position of the light spot outward. After processing, the center position information of the light spot generated on the inner wall of the deep hole 13 of the workpiece to be measured is obtained. Finally, based on the accurate distance value of the center position of the light spot from the reference origin, the value of the distance between the inner wall of the deep hole 13 of the workpiece to be measured and the central axis is quickly calculated, that is, the diameter of the deep hole 13 of the workpiece to be measured.

[0029] This invention provides a high-precision optical inspection method for deep hole internal inspection, comprising the following steps: Step 1: Place the measuring probe into the deep hole 13 of the workpiece to be measured, rotate it around its own axis to collect initial measurement information of the current cross section from multiple angles, and adjust the posture and position of the measuring probe synchronously based on the information so that the central axis of the laser emitter 3 coincides with the central axis of the deep hole 13 of the workpiece to be measured, thus completing the optical alignment. Step 2: Using the optically aligned measurement probe, acquire the laser beam spot position information in real time, extract the pixel offset of the spot center relative to the reference origin of the linear CCD sensor 9, and convert it into the actual physical distance. ; Step 3: Based on physical distance The hole diameter D at the cross section of the deep hole 13 in the workpiece under test is calculated. Step 4: Push the measuring probe axially using push rod 1, and repeat steps 2 to 3 to obtain the hole diameter of the deep hole 13 at different depths of the workpiece to be measured.

[0030] In step three, assuming the contact point between the laser beam and the inner wall of the deep hole 13 of the workpiece under test is A, the contact point between the laser beam and the inner wall of the deep hole 14 of the standard workpiece is B, the intersection point of the diffusely reflected laser beam reflected from the hole wall and the center of the main plane of the receiving lens module 8 is O, and the contact point between the diffusely reflected laser beam from the inner wall of the deep hole 13 of the workpiece under test and the linear CCD sensor 9 is denoted as... The contact point between the laser beam reflected from the inner wall of the deep hole 14 of the standard workpiece and the linear CCD sensor 9 is denoted as... Point A is on line segment The projection of the point is point C. Point on line segment The projection on is a point Assume the distance from the inner wall of the 14-inch deep hole in the standard workpiece to the center of the horizontal laser beam is... The distance between A and B is The distance between BO is , The distance between them is , The relative distance between them is The angle between the diffusely reflected laser beam from the inner wall of the deep hole 14 of the standard workpiece and the receiving plane of the linear CCD sensor 9 is... The angle between the specularly reflected laser beam and the diffusely reflected laser beam from the inner wall of the deep hole 14 of the standard workpiece is... During the testing process, according to The value can be calculated. The value is then used to obtain the hole diameter D of the deep hole 13 in the workpiece to be measured. The specific calculation principle is as follows: Depend on We can obtain: ; Based on the diagram, the geometric relationship can be obtained: , , , , , .

[0031] Substituting the above geometric relationship into equation (1) and simplifying, we get: ; Radius of the deep hole 13 in the workpiece to be measured For standard workpieces, the deep hole radius is 14. minus Then we have: ; Since the above calculations are based on the premise that the inner wall of the deep hole 13 of the workpiece being tested is lower than the inner wall of the deep hole 14 of the standard workpiece, the radius of the deep hole 13 of the workpiece being tested can be obtained similarly if the inner wall of the deep hole 13 of the workpiece being tested is higher than the inner wall of the deep hole 14 of the standard workpiece. for: ; In summary, the radius of the 13-meter deep hole in the workpiece to be tested is: ; The diameter of the 13-hole deep hole in the workpiece to be tested is: ; When the diameter of the deep hole 13 in the workpiece to be tested is larger than the diameter of the deep hole 14 in the standard workpiece, the formula (6) The symbol is , The symbol is When the diameter of the deep hole 13 in the workpiece to be tested is smaller than the diameter of the deep hole 14 in the standard workpiece, the formula (6) The symbol is , The symbol is .

[0032] Therefore, by measuring the distance between the inner wall of the deep hole 13 of the workpiece under test and the inner wall of the deep hole 14 of the standard workpiece, the center of the light spot projected on the linear CCD sensor 9 is obtained. The diameter of the deep hole 13 of the workpiece to be tested can be calculated according to formula (6).

[0033] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, alterations, or substitutions made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-precision optical inspection device for deep hole internal inspection, characterized in that, include: Measurement probe and computing unit; the measurement probe is placed inside the deep hole (13) of the workpiece to be measured during measurement; The measurement probe includes a laser emitter (3), an optical system assembly (4), a reflector mechanism (5), a receiving lens module (8), and a linear CCD sensor (9). The laser emitter (3) has the optical system component (4) installed at its emitting end. The laser beam emitted by the laser emitter (3) is focused and collimated by the optical system component (4) and irradiates the reflector mechanism (5). The reflector mechanism (5) is used to reflect the laser beam onto the inner wall of the deep hole (13) of the workpiece to be tested. The laser beam forms a reflected beam on the inner wall of the deep hole (13) of the workpiece to be tested. The receiving lens module (8) is used to receive the reflected beam and focus it onto the linear CCD sensor (9). The calculation unit is used to calculate the diameter of the deep hole (13) of the workpiece to be tested based on the data from the linear CCD sensor (9).

2. The high-precision optical inspection device for deep hole internal inspection according to claim 1, characterized in that, The laser emitter (3), optical system components (4), reflector mechanism (5), receiving lens module (8) and linear CCD sensor (9) are mounted on the housing body (12), and the tail of the housing body (12) is fixedly connected to the transmission line (2), which is connected to the laser emitter (3).

3. The high-precision optical inspection device for deep hole internal inspection according to claim 1, characterized in that, The optical system component (4) includes a pinhole grating (401), a condenser lens (402), and a collimating lens (403) arranged sequentially along the optical path transmission direction.

4. A high-precision optical inspection device for deep hole internal inspection according to claim 1, characterized in that, The reflector mechanism (5) includes a reflector (501), a support plate (502), a universal joint (503), a gear set (504), a gear adjusting rod (505), a lead screw (506), a sliding column (507), and a clamping plate (509). The reflector (501) is fixed on the support plate (502). Three universal joints (503) are installed at the bottom of the support plate (502). One of the universal joints (503) is positioned lower and is fixedly connected to the slide column (507) by a screw (508). The slide column (507) is movably connected to the clamping plate (509). The other two universal joints (503) are positioned higher and are fixedly connected to the corresponding lead screws (506) by screws (508). The two lead screws (506) pass through the clamping plate (509). The gear set (504) includes a sun gear and planet gears; the sun gear is fixedly connected to the gear adjusting rod (505); the clamping plate (509) is provided with a hole for the sun gear to pass through, so that the sun gear is located above or below the clamping plate (509); there are three planet gears, two of which are rotatably disposed on the bottom surface of the clamping plate (509) and threaded onto two lead screws (506), and the other planet gear is rotatably disposed on the top surface of the clamping plate (509) and threaded onto one of the lead screws (506); When the gear adjusting rod (505) is in the lower position and rotates, it drives the sun gear to rotate, which in turn drives the two planetary gears to rotate, causing the two lead screws (506) to generate radial displacement and push the slide column (507) to move back and forth, so that the reflector (501) rotates around the X direction; when the gear adjusting rod (505) is raised to the upper end and rotates, it will drive the planetary gear (504) on the upper side to rotate, which in turn drives the matching lead screw (506) to move independently, so that the reflector (501) rotates around the Y direction.

5. A high-precision optical inspection device for deep hole internal inspection according to claim 4, characterized in that, The card plate (509) is mounted on the housing body (12) by screws (508).

6. A high-precision optical inspection device for deep hole internal inspection according to claim 1, characterized in that, The receiving lens module (8) includes a first lens (L1), a second lens (L2), a third lens (L3), a fourth lens (L4), a grating (STO), a fifth lens (L5), a sixth lens (L6), a seventh lens (L7), and an imaging surface (IMA) arranged sequentially along the optical path transmission direction. The first lens (L1) has positive optical power, and the object side (S1) of the first lens (L1) is convex and the image side (S2) is concave. The second lens (L2) has positive optical power, and the object side (S3) of the second lens (L2) is convex and the image side (S4) is concave. The third lens (L3) has positive optical power. The object side (S5) of the third lens (L3) is convex, and the image side (S6) is flat. It is cemented with the fourth lens (L4). The fourth lens (L4) has negative optical power, and the image-side surface (S7) of the fourth lens (L4) is concave. The fifth lens (L5) has negative optical power. The object side (S8) of the fifth lens (L5) is concave, and the image side (S9) is flat. It is cemented with the sixth lens (L6). The sixth lens (L6) has positive optical power, and the image-side surface (S10) of the sixth lens (L6) is convex. The seventh lens (L7) has positive optical power, and both the object side (S11) and the image side (S12) of the seventh lens (L7) are convex.

7. A high-precision optical inspection device for deep hole internal inspection according to claim 1, characterized in that, The linear CCD sensor (9) includes at least three rows of photosensitive units (903) arranged one by one. When the reflected laser beam is projected onto the linear CCD sensor (9), the photosensitive unit (903) at the corresponding position transmits information to the shift register (902) through the transfer grid (901). Then, the shift register (902) transmits the information of the position of the light spot to the outside. After processing, the center position information of the light spot generated by the inner wall of the deep hole (13) of the workpiece to be tested is obtained. Finally, based on the accurate distance value of the center position of the light spot from the reference origin, the value of the distance between the inner wall of the deep hole (13) of the workpiece to be tested and the central axis is quickly calculated, which is used as the hole diameter of the deep hole (13) of the workpiece to be tested.

8. A high-precision optical inspection method for deep hole internal inspection, characterized in that, Includes the following steps: Step 1: Place the measuring probe into the deep hole (13) of the workpiece to be measured, rotate it around its own axis to collect the initial measurement information of the current cross section from multiple angles, and adjust the posture and position of the measuring probe synchronously based on the initial measurement information of multiple angles so that the central axis of the laser emitter (3) coincides with the central axis of the deep hole (13) of the workpiece to be measured, and complete the optical alignment. Step 2: Using the measurement probe that has completed optical alignment, the position information of the laser beam spot is acquired in real time. The pixel offset of the spot center relative to the reference origin of the linear CCD sensor (9) is extracted and converted into the actual physical distance. ; Step 3: Based on physical distance The hole diameter D at the cross section of the deep hole (13) of the workpiece under test is calculated. Step 4: Push the measuring probe axially by pushing the push rod, and repeat steps 2 to 3 to obtain the hole diameter of the deep hole (13) of the workpiece under test at different depths.

9. A high-precision optical inspection method for deep hole internal inspection according to claim 8, characterized in that, The calculation process in step three includes: Let A be the contact point between the laser beam and the inner wall of the deep hole (13) of the workpiece under test, B be the contact point between the laser beam and the inner wall of the deep hole (14) of the standard workpiece, O be the intersection point of the diffusely reflected laser beam reflected from the hole wall and the center of the main plane of the receiving lens module (8), and let O be the contact point between the diffusely reflected laser beam from the inner wall of the deep hole (13) of the workpiece under test and the linear CCD sensor (9). The contact point between the laser beam reflected from the inner wall of the deep hole (14) of the standard workpiece and the linear CCD sensor (9) is denoted as... Point A is on line segment The projection of the point is point C. Point on line segment The projection on is a point The distance from the inner wall of the deep hole (14) of the standard workpiece to the center of the horizontal laser beam is set as follows: The distance between A and B is The distance between BO is , The distance between them is , The relative distance between them is The angle between the diffusely reflected laser beam from the inner wall of the deep hole (14) of the standard workpiece and the receiving plane of the linear CCD sensor (9) is... The angle between the specularly reflected laser beam and the diffusely reflected laser beam inside the deep hole (14) of the standard workpiece is... ; according to Value calculated The value is then used to obtain the hole diameter D of the deep hole (13) of the workpiece to be measured. The calculation process is as follows: Depend on We can obtain: ； The geometric relation is: , , , , , ; Substituting the geometric relation into equation (1) and simplifying, we get: ； Radius of the deep hole (13) of the workpiece to be measured Radius of the deep hole (14) of the standard workpiece minus Then we have: ； When the inner wall of the deep hole (13) of the workpiece to be tested is higher than the inner wall of the deep hole (14) of the standard workpiece, the radius of the deep hole (13) of the workpiece to be tested... for: ； The radius of the deep hole (13) in the workpiece to be tested is: ； The diameter of the deep hole (13) in the workpiece to be tested is: ； When the diameter of the deep hole (13) of the workpiece to be tested is larger than the diameter of the deep hole (14) of the standard workpiece, the formula (6) The symbol is , The symbol is When the diameter of the deep hole (13) of the workpiece to be tested is smaller than the diameter of the deep hole (14) of the standard workpiece, the formula (6) The symbol is , The symbol is .

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