A device and method for real-time detection of deep hole roundness and surface morphology

Abstract

This invention provides a real-time detection device and method for the roundness and surface morphology of deep holes, belonging to the technical field of deep hole detection. The aforementioned real-time detection device integrates mechanics, electronics, and optics, featuring a simple structure, low cost, and ease of use. It can completely replicate the information of the inner wall of the deep hole onto a data processing system using a CCD camera. By comparing aperture I with an ideal circular outline, the roundness is calculated using the least squares method. The surface morphology is analyzed by examining the changes in image intensity information obtained from the halo formed by apertures I and II, allowing for the extraction of information about local discontinuities, such as cracks and holes. The use of a pulse positioning sensor and a photoelectric encoder enables detection at any position on the hole wall, significantly improving the precision of roundness and surface morphology detection for deep hole parts, representing a major breakthrough in deep hole detection technology.

Description

Technical Field

[0001] This invention belongs to the technical field of deep hole detection, and specifically discloses a device and method for real-time detection of deep hole roundness and surface morphology. Background Technology

[0002] With the rapid development of modern science and technology and modern industry, deep-hole parts, such as hollow axles, cylinders, hydraulic cylinders, and artillery barrels, have wide and important applications in the automotive and defense industries. Deep hole machining is one of the most challenging aspects of mechanical manufacturing. Due to tool deflection and vibration, ensuring straightness, cylindricity, and internal diameter tolerances is extremely difficult. Furthermore, deep-hole parts are often used in shaft-hole mating applications, typically facing severe wear, vibration, and thermal environments. Therefore, their inner walls are prone to cracks and other defects, further affecting the sealing and motion performance of the components. Thus, the detection of shape errors, dimensional errors, and defects on the inner surface of deep holes is of great significance for the quality control and fault diagnosis of these parts.

[0003] In certain fields, mechanical systems place higher demands on the precision of deep-hole parts. The shape and position errors of mechanical parts largely reflect their machining accuracy. Roundness error, in particular, refers to the variation of the actual circle of any cross-section of a measured cylindrical surface relative to the ideal circle, and it serves as the basis for evaluating many other form and position errors. For rotating parts or their rotating surfaces, there are numerous and highly accurate methods for measuring the outer diameter, while high-precision methods for measuring the hole diameter are relatively few, especially in the surface inspection of deep-hole parts, where traditional measurement methods and instruments are significantly limited. Although many sensors now enable non-contact measurement with high accuracy, such as roundness detection methods based on laser displacement sensors and fiber optic sensors that utilize part rotation or sensor rotation, most of these methods involve large amounts of data, are overly complex, and are prone to various minute errors, which greatly reduce the accuracy of the measurement.

[0004] Currently, in deep hole inspection, defects within the hole wall can significantly affect the accuracy of roundness detection. Detecting both defects and roundness within the hole wall can extend the lifespan of deep hole components and greatly reduce roundness errors, thus improving inspection accuracy. Therefore, researching a detection device capable of simultaneously detecting the roundness and surface morphology of deep holes is of paramount importance. Summary of the Invention

[0005] This invention provides a device and method for real-time detection of roundness and surface morphology of deep holes, in order to solve the technical problem that it is difficult to detect roundness and defects simultaneously in deep hole detection.

[0006] This invention provides a real-time detection device for the roundness and surface morphology of deep holes, comprising a centering mechanism, a detection mechanism, a linear drive mechanism, and a data processing system. The detection mechanism includes a transparent tube, a laser emitter, a halo generator, a diffuser, a lens, a projection screen, and a CCD camera. The laser emitter, halo generator, diffuser, lens, projection screen, and CCD camera are installed inside the transparent tube, and their centers are all located on the central axis of the transparent tube. An ideal circular outline is drawn on the projection screen. The halo generator includes a negative lens, a positive lens, a circular slit, and a conical reflector. The light emitted by the laser emitter is collimated and expanded by the negative and positive lenses, passes through the circular slit, and is incident on the conical reflector. Part of the reflected light is projected onto the inner wall of the deep hole to form an aperture I, and part passes through the diffuser. Aperture II is formed on the inner wall of the deep hole. Aperture I and Aperture II are reflected by the inner wall of the deep hole to a lens, which focuses them onto a projection screen. The projection screen transmits aperture I, aperture II, and the ideal circular profile to a CCD camera. The CCD camera converts the optical image into a digital signal and transmits it to the data processing system. The data processing system is used to compare and analyze the ideal circular profile with aperture I, calculate the roundness error, perform image processing, roundness fitting, and intensity information extraction on the halo formed by aperture I and aperture II, analyze the light intensity value of the halo, and extract information about local discontinuities. A centering mechanism is installed at both ends of the transparent tube to make the central axis of the transparent tube coincide with the axis of the deep hole. A linear drive mechanism is used to drive the centering mechanism and the detection mechanism to move linearly along the axis of the deep hole.

[0007] Furthermore, the centering mechanism includes a centering seat, a mounting shaft, a positioning body, an elastic element, a sliding body, a compression spring, and a knob; the first end face of the centering seat is connected to the end of the transparent tube, and its center is located on the central axis of the transparent tube; the mounting shaft is fixed to the second end face of the centering seat and is coaxially arranged with the centering seat; the positioning body is sleeved on the mounting shaft, its first end face is in contact with the second end face of the centering seat, and the second end face is provided with a wedge-shaped groove; the positioning body is made of elastic material and has multiple protruding elastic elements arranged circumferentially; the sliding body includes a sliding sleeve, a guide ring, and a wedge-shaped slider. The slider is slidably mounted on the mounting shaft; the first end face of the wedge slider is a wedge-shaped surface, and the second end face is an annular surface. The first end face is inserted into the wedge groove of the positioning body; the first end face of the guide ring is connected to the second end face of the wedge slider; the sliding sleeve is mounted on the guide ring; the compression spring and the knob are mounted on the mounting shaft. The compression spring is located in the annular space formed by the mounting shaft, the sliding sleeve, the guide ring, and the knob. The two ends of the compression spring abut against the guide ring and the knob; the knob is used to push the slider along the mounting shaft to squeeze the positioning body and the elastic element, so that the elastic element expands radially and contacts the inner wall of the deep hole.

[0008] Furthermore, the knob is connected to the mounting shaft via a threaded connection.

[0009] Furthermore, the linear drive mechanism includes a lead screw, a nut, a motor, and a fixed bracket; the nut is rotatably mounted on the fixed bracket and is driven to rotate by the motor; the lead screw passes through the nut to form a lead screw-nut pair, and its end is connected to the knob of the single-sided centering mechanism, with the lead screw and the centering mechanism being coaxially arranged.

[0010] Furthermore, balls are rotatably mounted within the helical raceway of the nut.

[0011] Furthermore, the lead screw is equipped with scale values.

[0012] Furthermore, the motor is equipped with a photoelectric encoder for acquiring motor rotation data, and the photoelectric encoder is connected to the data processing system.

[0013] Furthermore, a pulse positioning sensor is installed on the transparent tube, and the pulse positioning sensor is connected to the data processing system.

[0014] Furthermore, the CCD camera lens uses a conical lens.

[0015] The present invention also provides a method for real-time detection of the roundness and surface morphology of deep holes. The deep hole part is fixed in a horizontal position, and then the detection mechanism in the above-mentioned real-time detection device for the roundness and surface morphology of deep holes is placed inside the deep hole part. The centering mechanism and the detection mechanism are driven by a linear drive mechanism to move linearly along the axis of the deep hole.

[0016] The present invention has the following beneficial effects:

[0017] The aforementioned real-time detection device for deep hole roundness and surface morphology integrates mechanics, electronics, and optics. It features a simple structure, low cost, and ease of use. It can completely replicate the information of the deep hole's inner wall onto a data processing system using a CCD camera. By comparing aperture I with an ideal circular outline, the roundness is calculated using the least squares method. The surface morphology is analyzed by examining the changes in image intensity information obtained from the halo formed by apertures I and II, allowing for the extraction of information about local discontinuities, such as cracks and holes. The use of a pulse positioning sensor and a photoelectric encoder enables detection at any position on the hole wall, significantly enhancing the precision of roundness and surface morphology detection for deep hole parts and representing a major breakthrough in deep hole detection technology. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of a device for real-time detection of deep hole roundness and surface morphology.

[0020] Figure 2 Optical path diagram of a real-time detection device for deep hole roundness and surface morphology;

[0021] Figure 3 This is a schematic diagram of the centering mechanism;

[0022] In the diagram: 1-Laser emitter; 2-Halo generator; 2.1-Negative lens; 2.2-Positive lens; 2.3-Circular slit; 2.4-Conical mirror; 3-Diffuser; 4-Lens; 5-Projection screen; 6-CCD camera; 7-Centering seat; 8-Positioning body; 9-Elastic element; 10-Slider; 10.1-Sliding sleeve; 10.2-Guide ring; 10.3-Wedge slider; 11-Compression spring; 12-Knob; 13-Lead screw; 14-Nut; 15-Motor; 16-Fixed bracket; 17-Pulse positioning sensor; 18-Computer; 19-Ball bearing; 20-Mounting shaft; 100-Deep hole inner wall; 101-Aperture I; 102-Aperture II; 103-Halo. Detailed Implementation

[0023] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1

[0025] This embodiment provides a real-time detection device for the roundness and surface morphology of deep holes, including a centering mechanism, a detection mechanism, a linear drive mechanism, and a data processing system.

[0026] The testing mechanism includes a transparent tube, a laser emitter 1 (using a laser diode), a halo generator 2, a diffuser 3, a lens 4, a projection screen 5, and a CCD camera 6. The laser emitter 1, halo generator 2, diffuser 3, lens 4, projection screen 5, and CCD camera 6 are installed inside the transparent tube, with their centers all located on the central axis of the transparent tube. An ideal circular outline is drawn on the projection screen 5. The halo generator 2 includes a negative lens 2.1, a positive lens 2.2, a circular slit 2.3, and a conical reflector 2.4. The light emitted by the laser emitter 1 is collimated and expanded by the negative lens 2.1 and the positive lens 2.2, passes through the circular slit 2.3, and is incident on the conical reflector 2.4. Part of the reflected light is projected onto the inner wall of the deep hole to form an aperture I101, and part of it passes through the diffuser 3 onto the inner wall of the deep hole. Aperture II 102 is formed. Aperture I 101 and aperture II 102 are reflected by the inner wall of the deep hole to the lens, which focuses them onto the projection screen 5. The projection screen 5 transmits aperture I 101, aperture II 102 and the ideal circular profile to the CCD camera 6. The CCD camera 6 converts the optical image into a digital signal and transmits it to the data processing system. The data processing system is used to compare and analyze the ideal circular profile with aperture I 101, calculate the roundness error using the least squares method, and perform image processing, roundness fitting and intensity information extraction on the ring 103 formed by aperture I 101 and aperture II 102. The morphological information of the inner surface of the hole contained in the ring pattern is then revealed. The light intensity value of the ring 103 is analyzed to extract information about local discontinuities, such as cracks and holes.

[0027] Furthermore, the CCD camera 6 lens uses a conical lens, which can improve the size of the effective area and radial resolution on the camera sensor, and reduce the dead area.

[0028] The centering mechanism is installed at both ends of the transparent tube and keeps in contact with the inner wall of the deep hole to adapt to changes in the diameter of the deep hole. It is used to make the central axis of the transparent tube coincide with the axis of the deep hole and eliminate the deviation caused by axis offset during the detection process. The centering mechanism includes a centering seat 7, a mounting shaft 20, a positioning body 8, an elastic element 9, a slider 10, a compression spring 11, and a knob 12. The first end face of the centering seat 7 is connected to the end of the transparent tube, and its center is located on the central axis of the transparent tube. The mounting shaft 20 is fixed to the second end face of the centering seat 7 and is coaxially arranged with the centering seat 7. The positioning body 8 is sleeved on the mounting shaft 20, and its first end face is in contact with the second end face of the centering seat 7. The second end face is provided with a wedge-shaped groove. The positioning body 8 is made of elastic material and has multiple protruding elastic elements 9 arranged circumferentially. The slider 10 includes a sliding sleeve 10.1, a guide ring 10.2, and a wedge-shaped slider 10.3. The guide ring 10.2 and the wedge-shaped slider 10.3 are slidably sleeved on the mounting shaft 20. The first end face of the wedge-shaped slider 10.3 is a wedge-shaped surface, and the second end face is an annular surface. The first end face is inserted into the... The guide ring 10.2 is located in the wedge-shaped groove of the positioning body 8. The first end face of the guide ring 10.2 is connected to the second end face of the wedge-shaped slider 10.3. The sliding sleeve 10.1 is sleeved on the guide ring 10.2. The compression spring 11 and the knob 12 are sleeved on the mounting shaft 20. The compression spring 11 is located in the annular space formed by the mounting shaft 20, the sliding sleeve 10.1, the guide ring 10.2 and the knob 12. The two ends of the compression spring 11 abut against the guide ring 10.2 and the knob 12. The knob 12 is used to push the slider 10 along the mounting shaft 20 to squeeze the positioning body 8 and the elastic element 9, so that the elastic element 9 expands radially and contacts the inner wall of the deep hole. This achieves the purpose of using the inner wall surface of the deep hole as its positioning reference, automatic centering and support of the deep hole detection mechanism. The elastic element 9 is in sliding contact with the inner wall of the deep hole, which helps to reduce the friction during travel and improve the detection accuracy.

[0029] Furthermore, the knob 12 is connected to the mounting shaft 20 by a thread. The axial force generated by the compression spring 11 can be controlled by the screw depth of the knob 12, thereby improving the centering accuracy.

[0030] The linear drive mechanism is used to drive the centering mechanism and the detection mechanism to move linearly along the axis of the deep hole. The linear drive mechanism includes a lead screw 13, a nut 14, a motor 15, and a fixed bracket 16. The nut 14 is rotatably mounted on the fixed bracket 16 to prevent misalignment and is driven to rotate by the motor 15. The lead screw 13 passes through the nut 14 to form a lead screw-nut pair, and its end is rigidly connected to the knob 12 of the single-sided centering mechanism. The lead screw 13 is coaxially arranged with the centering mechanism. The rotation of the motor 15 drives the nut 14 to rotate, which in turn drives the lead screw 13 to move linearly. The forward and reverse rotation of the motor 15 controls the reciprocating detection of the detection mechanism within the hole.

[0031] Furthermore, a ball bearing 19 is rotatably mounted inside the spiral raceway of the nut 14, forming a ball screw with the lead screw 13.

[0032] Furthermore, the lead screw 13 is equipped with a scale. The scale value allows for a clearer understanding of the position and displacement of the detection mechanism within the hole.

[0033] Furthermore, the motor 15 is equipped with a photoelectric encoder for acquiring rotation data of the motor 15, and the photoelectric encoder is connected to the data processing system.

[0034] Furthermore, a pulse positioning sensor 17 is installed on the transparent tube. The pulse positioning sensor 17 is connected to the data processing system and can detect the position information of the detection mechanism inside the hole.

[0035] Specifically, the data processing system includes a computer 18 and data cables.

[0036] Example 2

[0037] This embodiment provides a method for real-time detection of the roundness and surface morphology of deep holes. The deep hole part is fixed in a horizontal position, and then the detection mechanism in the above-mentioned real-time detection device for the roundness and surface morphology of deep holes is placed inside the deep hole part. The centering mechanism and the detection mechanism are driven by a linear drive mechanism to move linearly along the axis of the deep hole.

[0038] The detection mechanism moves along the axis of the deep hole. The photoelectric encoder detects the rotation parameters of the motor 15, and the feed distance of the detection mechanism is determined by the scale on the lead screw 13. The projection position of the light ring on the inner wall of the deep hole can be obtained by the position of the pulse positioning sensor 17 and the refractive index of the light ring generator 2. The motor 15 is controlled to make the lead screw 13 drive the detection mechanism. Through the cooperation between the photoelectric encoder and the pulse positioning sensor 17, the roundness of any cross section inside the hole can be detected, and multiple sets of data can be measured to achieve full-range detection of the deep hole.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time detection device for the roundness and surface morphology of deep holes, characterized in that, This includes a centering mechanism, a detection mechanism, a linear drive mechanism, and a data processing system; The detection mechanism includes a transparent tube, a laser emitter, a halo generator, a diffuser, a lens, a projection screen, and a CCD camera; The laser emitter, halo generator, diffuser, lens, projection screen and CCD camera are installed inside the transparent tube, and their centers are all located on the central axis of the transparent tube. An ideal circular outline is drawn on the projection screen; The halo generator includes a negative lens, a positive lens, a circular slit, and a conical reflector; The light emitted by the laser emitter is collimated and expanded by the negative and positive lenses, passes through the circular slit, and is incident on the conical mirror. Part of the reflected light is projected onto the inner wall of the deep hole to form aperture I, and part of the light passes through the diffuser to form aperture II on the inner wall of the deep hole. Aperture I and aperture II are reflected by the inner wall of the deep hole to the lens, which focuses the light onto the projection screen. The projection screen transmits aperture I, aperture II, and the ideal circular outline to the CCD camera. The CCD camera converts the optical image into a digital signal and transmits it to the data processing system. The data processing system is used to compare and analyze the ideal circular profile with aperture I, calculate the roundness error, perform image processing, roundness fitting and intensity information extraction on the halo formed by aperture I and aperture II, analyze the light intensity value of the halo, and extract information about local discontinuities. The centering mechanism is installed at both ends of the transparent tube to make the central axis of the transparent tube coincide with the axis of the deep hole; The linear drive mechanism is used to drive the centering mechanism and the detection mechanism to move linearly along the axis of the deep hole.

2. The real-time detection device for deep hole roundness and surface morphology according to claim 1, characterized in that, The centering mechanism includes a centering seat, a mounting shaft, a positioning body, an elastic element, a sliding body, a compression spring, and a knob; The first end face of the centering seat is connected to the end of the transparent tube, and its center is located on the central axis of the transparent tube; The mounting shaft is fixed to the second end face of the centering seat and is coaxially arranged with the centering seat. The positioning body is sleeved on the mounting shaft, with its first end face connected to the second end face of the centering seat. The second end face is provided with a wedge-shaped groove. The positioning body is made of elastic material and has multiple protruding elastic elements arranged circumferentially. The sliding body includes a sliding sleeve, a guide ring, and a wedge-shaped slider, with the guide ring and wedge-shaped slider slidably mounted on the mounting shaft; The first end face of the wedge-shaped slider is a wedge-shaped surface, and the second end face is an annular surface. The first end face is inserted into the wedge-shaped groove of the positioning body. The first end face of the guide ring is in contact with the second end face of the wedge-shaped slider; The sliding sleeve is fitted onto the guide ring; The compression spring and the knob are sleeved on the mounting shaft. The compression spring is located in the annular space formed by the mounting shaft, the sliding sleeve, the guide ring and the knob. The two ends of the compression spring abut against the guide ring and the knob. The knob is used to push the sliding body along the mounting axis to squeeze the positioning body and the elastic element, so that the elastic element expands radially and contacts the inner wall of the deep hole.

3. The real-time detection device for deep hole roundness and surface morphology according to claim 2, characterized in that, The knob is connected to the mounting shaft by a thread.

4. The real-time detection device for deep hole roundness and surface morphology according to claim 3, characterized in that, The linear drive mechanism includes a lead screw, a nut, a motor, and a fixed bracket; The nut is rotatably mounted on a fixed bracket and is driven to rotate by a motor. The lead screw passes through the nut to form a lead screw and nut pair, and its end is connected to the knob of the single-sided centering mechanism. The lead screw and the centering mechanism are coaxially arranged.

5. The real-time detection device for deep hole roundness and surface morphology according to claim 4, characterized in that, Ball bearings are rotatably mounted inside the spiral raceway of the nut.

6. The real-time detection device for deep hole roundness and surface morphology according to claim 4 or 5, characterized in that, The lead screw has a scale value.

7. The real-time detection device for deep hole roundness and surface morphology according to claim 6, characterized in that, The motor is equipped with a photoelectric encoder for acquiring motor rotation data, and the photoelectric encoder is connected to the data processing system.

8. The real-time detection device for deep hole roundness and surface morphology according to claim 7, characterized in that, A pulse positioning sensor is installed on the transparent tube, and the pulse positioning sensor is connected to the data processing system.

9. The real-time detection device for deep hole roundness and surface morphology according to claim 8, characterized in that, CCD camera lenses use conical lenses.

10. A method for real-time detection of the roundness and surface morphology of deep holes, characterized in that, The deep hole part is fixed in a horizontal position, and then the detection mechanism in the real-time detection device for the roundness and surface morphology of the deep hole as described in any one of claims 1-9 is placed inside the deep hole part. The centering mechanism and the detection mechanism are driven by the linear drive mechanism to move linearly along the axis of the deep hole.

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