A micro-prism mold processing tool angle precision measuring device and method

Abstract

The present application relates to the field of ultra-precision machining and micro-nano optical detection technology, and particularly relates to a micro-prism mold machining tool angle precision measurement device and method. The structure comprises a laser emission module, a cubic beam splitter, a beam deflector, a reflecting element, an imaging detector, an image processing system, a mounting clamp with a six-dimensional adjustment mechanism, and a data processing unit. The cubic beam splitter divides two parallel light beams, which are respectively irradiated to two measured blade surfaces of the tool through a rotating double optical wedge beam deflector. The present application synchronously measures the two blade surfaces of the tool through two light beams, avoids the repeated clamping error introduced by the traditional separate clamping and separate measurement method, and thus improves the measurement repeatability. The rotating double optical wedge beam lever is used to realize high-precision light beam regulation and control, and the tool angle measurement precision reaches ±0.01°. The present application can detect small tools with a size of ≤5mm and opaque infrared optical elements, has a low cost, and is suitable for on-site tool quality control in a workshop.

Description

Technical Field

[0001] This invention relates to the fields of ultra-precision machining and micro-nano optical detection technology, and in particular to a device and method for precision measuring the angle of cutting tools used in the machining of micro-pyramidal molds. Background Technology

[0002] In the ultra-precision machining industry, diamond tools are widely used in the processing and manufacturing of optical components, semiconductor devices, and micro / nano structure molds. The measurement accuracy of the tool's cutting edge angle and edge posture directly determines the surface quality and geometric dimensional accuracy of the workpiece being machined. In micro / nano machining scenarios, the control of the tool's cutting edge angle and axis offset angle needs to reach an accuracy level of 0.01° (36 arcseconds).

[0003] Currently, the mainstream methods used in the industry for tool cutting edge angle detection mainly include three types: ultra-depth-of-field image measurement, absolute goniometer, and traditional laser autocollimation comparison goniometer. However, all of them have technical shortcomings that are difficult to overcome.

[0004] The super depth-of-field image measurement method relies on microscope imaging and manual interpretation of the cutting edge boundary. It is simple to operate, but it is affected by optical resolution, environmental vibration, and the tilt of the surface being measured. The measurement accuracy is only about 0.10°, which is difficult to meet the sub-angle grading detection requirements in some high-precision tool inspection scenarios. At the same time, manual interpretation will introduce subjective errors and the measurement repeatability is poor.

[0005] The absolute goniometer employs a self-collimation detection mode with a fixed beam and a rotating component under test, relying on a rotary table encoder to acquire the angle. For detecting the cutting edge of micro-tools, repeated multi-dimensional adjustments to the workpiece's posture are necessary to ensure complete illumination of the cutting surface by the light spot. This method offers high measurement accuracy, but the equipment is relatively expensive and the debugging process is complex.

[0006] Autocollimation-based angle measurement devices represent an important development direction for angle detection. Chinese Invention Patent Application No. 202010045377.4 discloses a micro-angle detection device and method based on an autocollimator. This scheme adds a wedge mirror assembly to the autocollimator, enabling the detection of minute angle deviations. However, this scheme still has inherent limitations: the device uses a single-optical-path structure, requiring separate clamping and measurement of both cutting edges when measuring the tool's apex angle, introducing additional clamping posture errors; it only uses a single wedge mirror and lacks a high-sensitivity beam fine-tuning mechanism, resulting in limited beam angle control accuracy; this device is mainly designed for ordinary reflective workpieces and is not suitable for detecting micro-tools ≤5mm in size or opaque infrared optical elements such as germanium, silicon, and zinc selenide.

[0007] In addition, some commercial autocollimation comparative angle measurement devices are mainly designed for large transparent optical components, and their adaptability to smaller or opaque workpieces is limited. As ultra-precision machining evolves towards nanometer-level precision, tool cutting angle errors need to be controlled within 0.01°. Existing detection solutions cannot simultaneously achieve measurement accuracy, detection efficiency, and adaptability to small opaque workpieces. Some high-precision equipment is also too expensive and unsuitable for on-site quality control in the workshop.

[0008] Therefore, there is an urgent need for a precision measuring device and method for the cutting tool angle in micro-pyramidal mold processing that can detect the angle height of the cutting edge of tiny opaque workpieces. Summary of the Invention

[0009] Therefore, in view of the above problems, the present invention proposes a precision measuring device and method for the cutting tool angle in micro pyramid mold processing, which solves the technical problems of low cutting tool angle measurement accuracy, poor efficiency, limited applicable workpieces, and high cost.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: including a laser emitting module for outputting a parallel beam with high collimation, the laser emitting module comprising a single-mode semiconductor laser and a collimating objective lens, the diameter of the parallel beam output by the laser emitting module being less than 1 mm, and the spot diameter of the beam when incident on the cutting edge of the tool being smaller than the cutting edge size; A cubic beam splitter is disposed in the output optical path of the laser emitting module to split the incident beam into a first beam and a second beam, the first beam and the second beam being parallel to each other. This device includes two optical path configurations: the first configuration uses a right-angle reflecting prism, which is placed in the transmission optical path of the cubic beam splitter to deflect the transmitted beam of the cubic beam splitter by 90°, so that the transmitted beam and the reflected beam of the cubic beam splitter are parallel to each other; the second configuration does not use a right-angle reflecting prism, and achieves the parallelism of the first beam and the second beam by using a cubic beam splitter in conjunction with a subsequent reflected optical path. The first beam deflector and the second beam deflector are respectively disposed on the optical paths of the first beam and the second beam. Both the first beam deflector and the second beam deflector adopt a rotating double optical wedge structure and are each equipped with a precision angular displacement micrometer. The first reflective element and the second reflective element are respectively arranged for two optical paths, and are used to guide the beams emitted by the first beam deflector and the second beam deflector to the first test surface and the second test surface of the tool under test, respectively. An imaging detector is disposed on the reflected light path of the first and second test surfaces to receive the reflected light from the first and second test surfaces and form a light spot image. An image processing system, electrically connected to the imaging detector, is used to process the light spot image and display the light spot position information; The mounting fixture is used to mount and fix the tool to be tested or the standard angle gauge block. The mounting fixture is equipped with a six-dimensional adjustment mechanism. The data processing unit is used to calculate the cutting angle of the tool under test based on the spot position information of the imaging detector; The tool angle is precisely measured by comparing the difference in the position of the light spot caused by the tool under test and the standard angle gauge block.

[0011] Furthermore, the rotating double optical wedge structure includes a first optical wedge and a second optical wedge. Both the first and second optical wedges have a wedge angle of α and a refractive index of n. The two optical wedges rotate relative to each other at the same speed but in opposite directions. With the relative rotation angle relative to the zero reference position as ψ, the total deflection angle δ after beam transmission is calculated using the following formula: ;

[0012] When the main cross sections of the first and second optical wedges are in the same direction, the thick side is located on the right side, and the relative rotation angle ψ=0°, the beam deflects to the right to the maximum value. When the cross-sections of the first and second optical wedges are opposite to each other and the relative rotation angle ψ = 90°, the beam deflection angle is equal to 0. When the main cross-sections of the first and second optical wedges are in the same direction and the thick side is on the left, the beam deflects to the left to its maximum value when the relative rotation angle ψ = 180°.

[0013] Furthermore, the first beam deflector and the second beam deflector output a small beam deflection angle change through a large relative rotation angle change, so that after the detection beam is incident on the side of the test surface, the reflected light from the test surface can return along the incident light path and be imaged at the center of the imaging detector after being transmitted through the detection system.

[0014] Furthermore, by adjusting the deflection angles of the first and second reflective elements, a wide range of control over the incident beam deflection angle can be achieved to adapt to the measurement requirements of tools at different angles, so that the laser beam is perpendicularly incident on the surface to be measured and the reflected beam is imaged at the center of the imaging detector.

[0015] Furthermore, the imaging detector is a CCD or CMOS imaging sensor.

[0016] Furthermore, the parameter configuration of the precision angular displacement micrometer, single-mode semiconductor laser, collimating objective lens, and imaging detector enables the device to achieve a beam deflection accuracy of ±0.005° and a knife angle measurement accuracy of ±0.01°.

[0017] Furthermore, the six-dimensional adjustment mechanism of the mounting fixture includes three translational degrees of freedom along the X, Y, and Z axes and three rotational degrees of freedom φx, φy, and φz about the X, Y, and Z axes, which are used to adjust the posture of the tool to be tested.

[0018] Furthermore, the laser emission module output beam spot size, imaging detector resolution, and mounting fixture adjustment capability are combined to enable the device to detect workpieces with a minimum size of 1.2mm and adapt to the detection of micro-tools with a size ≤5mm.

[0019] A method for precise measurement of the angle of a cutting tool in the machining of a micro pyramidal mold includes a system calibration step and a tool measurement step. The system calibration step uses a standard angle gauge block to complete the device calibration. This standard angle gauge block enables the first and second beam deflectors to achieve self-collimation aiming without large-angle rotation. The step includes the following steps: S101: Fix the standard angle block to the mounting fixture; adjust the rotation angle of the first and second reflective elements, and adjust the XYZ adjustment knob of the mounting fixture so that the incident beam illuminates the center of the surface to be measured of the standard angle block. The beam reflected from the surface to be measured of the standard angle block forms an image on the imaging detector, and the light spot can be moved to the center of the imaging detector by adjusting the beam deflector. S102: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture so that the centers of the reflected light spots on the left and right sides of the standard angle block fall on the horizontal central axis of the imaging detector. S103: Adjust the precision angular displacement micrometer of the first beam deflector to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the left side of the test surface coincides with the center of the imaging detector, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position. a1 ; S104: Adjust the precision angular displacement micrometer of the second beam deflector to change the relative rotation angle of the double optical wedges, so that the center of the reflected light spot on the right side of the test surface coincides with the center of the imaging detector, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position. b1 ; S105: Complete the calibration of the precision comparison and measurement device for tool angles; The measurement steps for the tool under test include the following steps: S201: Remove the standard angle gauge block and fix the tool to be tested onto the mounting fixture on the six-dimensional adjustment platform; adjust the XYZ adjustment knob of the mounting fixture so that the two incident beams illuminate the centers of the two cutting surfaces of the tool to be tested respectively. S202: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture so that the centers of the reflected light spots on the left and right cutting surfaces of the tool under test fall on the horizontal central axis of the imaging detector. S203: When the left test surface of the tool under test has an angular deviation Δ relative to the left side of the calibration standard gauge block. a The right test surface of the tool under test has an angular deviation Δ relative to the right side of the calibration standard gauge block. b Angle deviation causes the reflected beam to deflect, and the light spot deviates from the center of the imaging detector; S204: Adjust the micrometer of the precision angular displacement of the first beam deflector to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the left side of the test blade returns to the center of the imaging detector, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position at this time. a2 ; angular deviation Δ a Satisfying the formula: ; S205: Adjust the precision angular displacement micrometer of the second beam deflector to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the right side of the test edge returns to the center of the imaging detector, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position at this time. b2 ; angular deviation Δ b Satisfying the formula: ; S206: The nominal angle β and angle deviation Δ are determined according to the calibration standard angle gauge block. a Δ b The actual tool angle θ of the tool under test is calculated using the following formula: .

[0020] Furthermore, a standard angle gauge block with an angle similar to that of the tool under test is selected for calibration, so that the rotating double-wedge beam deflector can complete self-collimation aiming without large-angle rotation.

[0021] By adopting the aforementioned technical solution, the beneficial effects of the present invention are: This invention achieves synchronous measurement of both sides of the cutting edge by setting up a laser emission module, a cubic beam splitter, and a right-angle reflecting prism to form a dual-beam symmetrical optical path. This avoids the clamping posture error introduced by the traditional single-beam scheme which requires clamping and measuring in multiple steps, and significantly improves measurement efficiency and repeatability. This invention can optionally be configured with a right-angle reflecting prism, or the right-angle reflecting prism can be omitted, and two parallel beam outputs can be achieved through other optical path arrangements, providing two optical path configurations to adapt to different overall structure and assembly space requirements; Furthermore, by employing a rotating double-wedge beam deflector containing a precision angular displacement micrometer, and utilizing the principle of double-wedge angular displacement levers—that is, when the double wedges rotate in opposite directions and generate a large relative rotation angle change, only a small beam deflection angle change occurs—the sensitivity and accuracy of beam deflection adjustment are significantly improved. This allows the device to achieve a beam deflection accuracy of ±0.005° and a knife angle measurement accuracy of ±0.01°, which is more than 10 times higher than the existing 0.10° measurement accuracy. Furthermore, by adjusting the deflection angles of the first and second reflective elements, a wide range of control over the incident beam deflection angle can be achieved. Calibration can be completed with standard angle gauge blocks of different specifications, which can adapt to the measurement needs of tools at different angles and achieve high-precision comparative measurement within a large angle range. This breaks through the limitation of traditional laser autocollimating goniometers that can only measure small-angle transparent optical elements. Furthermore, by combining the laser emission module's output beam spot size, the imaging detector's resolution, and the mounting fixture's adjustment capabilities, the device can detect workpieces as small as 1.2mm in size. It is suitable for detecting micro-tools with dimensions ≤5mm and opaque infrared optical components such as germanium, silicon, and zinc selenide. Compared to traditional commercial autocollimation comparative goniometers, which are only suitable for transparent optical components with dimensions ≥10mm, the device's applicability is significantly expanded. At the same time, the cost of the laser comparative goniometer-based device is several times lower than that of the laser autocollimation goniometer, making it suitable for quality control during product manufacturing processes in tool manufacturing workshops. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the precision measuring device for the cutting tool angle in the micro-pyramidal mold processing according to Embodiment 1 of the present invention (equipped with a right-angle reflecting prism). Figure 2 This is a schematic diagram of the precision measuring device for the cutting tool angle in the micro-pyramidal mold processing of Embodiment 2 of the present invention (without a right-angle reflecting prism). Figure 3 This is a schematic diagram of how the rotating double optical wedges of the present invention adjust the beam deflection angle by changing their relative rotation angle. Figure 1 ; Figure 4 This is a schematic diagram of how the rotating double optical wedges of the present invention adjust the beam deflection angle by changing their relative rotation angle. Figure 2 ; Figure 5 This is the present invention. Figure 4 Enlarged structural diagram of A in the middle; Figure 6 This is the present invention. Figure 4 Enlarged structural diagram of B in the middle; Figure 7 This is a schematic diagram of the deflection of the reflected light path when there is an angular deviation between the workpiece to be tested and the standard gauge block in Embodiment 1 of the present invention; Figure 8A schematic diagram of the reflected light path deflection when there is an angular deviation between the workpiece to be tested and the standard gauge block in Embodiment 2 of the present invention; In the figure: 1-Laser emitting module, 2-cubic beam splitter, 3-right-angle reflecting prism, 4a-first beam deflector, 4b-second beam deflector, 5a-first reflecting element, 5b-second reflecting element, 6-imaging detector, 7-image processing system, 8-mounting fixture, 9-data processing unit. Detailed Implementation

[0023] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Example 1

[0024] refer to Figure 1 This embodiment provides a precision measuring device for the angle of cutting tools used in the processing of micro-pyramidal molds, the structure of which includes: Laser emitting module 1 is used to output a parallel beam with high collimation. Laser emitting module 1 includes a single-mode semiconductor laser and a collimating objective lens. The diameter of the parallel beam output by laser emitting module 1 is less than 1 mm, and the diameter of the spot when the beam is incident on the cutting edge of the tool is smaller than the size of the cutting edge of the tool. A cubic beam splitter 2 is installed on the output optical path of the laser emitting module 1 to split the incident beam into an orthogonal first beam and a second beam. A right-angle reflecting prism 3 is set in the transmission light path of the cubic beam splitter 2 to deflect the transmitted beam of the cubic beam splitter 2 by 90° so that the transmitted beam and the reflected beam of the cubic beam splitter 2 are parallel to each other. The first beam deflector 4a and the second beam deflector 4b are respectively disposed on the optical paths of the first beam and the second beam. Both the first beam deflector 4a and the second beam deflector 4b adopt a rotating double optical wedge structure and are each equipped with a precision angular displacement micrometer. The first reflective element 5a and the second reflective element 5b are respectively set to correspond to two optical paths, and are used to guide the beams emitted by the first beam deflector 4a and the second beam deflector 4b to the first test surface and the second test surface of the tool under test, respectively. Imaging detector 6 is disposed on the reflected light path of the first test surface and the second test surface, and is used to receive the reflected light from the first test surface and the second test surface and form a light spot image; Image processing system 7, electrically connected to imaging detector 6, is used to process spot images and display spot position information; Mounting fixture 8 is used to mount and fix the tool to be tested or the standard angle gauge block. Mounting fixture 8 is equipped with a six-dimensional adjustment mechanism. Data processing unit 9 is used to calculate the cutting angle of the tool under test based on the spot position information of imaging detector 6; Among them, the tool angle is precisely measured by comparing the difference in the position of the light spot caused by the tool under test and the standard angle gauge block.

[0025] The rotating double optical wedge structure includes a first optical wedge and a second optical wedge. Both the first and second optical wedges have a wedge angle of α and a refractive index of n. The two wedges rotate relative to each other at the same speed but in opposite directions. With the relative rotation angle relative to the zero reference position as ψ, the total deflection angle δ after beam transmission is calculated using the following formula: ;

[0026] When the main cross sections of the first and second optical wedges are in the same direction, the thick side is located on the right side, and the relative rotation angle ψ=0°, the beam deflects to the right to the maximum value. When the cross-sections of the first and second optical wedges are opposite to each other and the relative rotation angle ψ = 90°, the beam deflection angle is equal to 0. When the main cross-sections of the first and second optical wedges are in the same direction and the thick side is on the left, the beam deflects to the left to its maximum value when the relative rotation angle ψ = 180°.

[0027] The first beam deflector 4a and the second beam deflector 4b output a small beam deflection angle change through a large relative rotation angle change, so that after the detection beam is incident on the side of the test surface, the reflected light from the test surface can return along the incident light path and be imaged at the center of the imaging detector 6 after being transmitted through the detection system.

[0028] By adjusting the deflection angles of the first reflective element 5a and the second reflective element 5b, a wide range of control over the incident beam deflection angle can be achieved to adapt to the measurement requirements of tools at different angles, so that the laser beam is reflected after being perpendicularly incident on the surface to be measured and imaged at the center of the imaging detector 6.

[0029] The imaging detector 6 is a CCD or CMOS imaging sensor.

[0030] The parameter configuration of the precision angular displacement micrometer, single-mode semiconductor laser, collimating objective lens, and imaging detector 6 enables the device to achieve a beam deflection accuracy of ±0.005° and a knife angle measurement accuracy of ±0.01°.

[0031] The six-dimensional adjustment mechanism of the mounting fixture 8 includes three translational degrees of freedom along the X, Y, and Z axes and three rotational degrees of freedom φx, φy, and φz about the X, Y, and Z axes, which are used to adjust the posture of the tool under test.

[0032] With the laser emission module 1 output beam spot size, imaging detector 6 resolution and mounting fixture 8 adjustment capability combined, the device can detect workpieces with a minimum size of 1.2mm and is suitable for detecting micro-tools with a size ≤5mm. Example 2

[0033] Reference manual attached Figure 2 The difference between this embodiment and embodiment one is that: this embodiment does not set the right-angle reflecting prism 3; after the cubic beam splitter 2 is emitted, the first beam and the second beam that are parallel to each other are directly obtained through the layout of the optical path reflecting elements. The structure, parameters, working principle and measurement method of the other devices are consistent with those of embodiment one.

[0034] The laser emitting module 1 outputs a beam that is incident on the cubic beam splitter 2. The cubic beam splitter 2 splits the first beam and the second beam. After subsequent optical path elements are arranged, the first beam and the second beam are made parallel to each other. The two beams enter the first beam deflector 4a and the second beam deflector 4b respectively. Then, they are projected onto the two cutting surfaces of the tool under test through the first reflector 5a and the second reflector 5b. The light reflected back from the cutting surfaces under test returns to the imaging detector 6 to complete the spot acquisition.

[0035] This embodiment can also achieve synchronous acquisition of the cutting surfaces on both sides of the tool, realize precise comparison and measurement of the tool angle, and the device beam deflection accuracy, tool angle measurement accuracy, and detectable workpiece size range are the same as in embodiment 1. Example 3

[0036] Reference manual attached Figures 1-8 A method for precise measurement of the angle of a cutting tool in the machining of a micro pyramid mold, comprising a system calibration step and a tool measurement step; The system calibration procedure uses a standard angle gauge block to complete the device calibration. This standard angle gauge block enables the first beam deflector 4a and the second beam deflector 4b to achieve self-collimation aiming without large-angle rotation. The procedure includes the following steps: S101: Fix the standard angle gauge block to the mounting fixture 8; adjust the rotation angle of the first reflective element 5a and the second reflective element 5b, and adjust the XYZ adjustment knob of the mounting fixture so that the incident beam illuminates the center of the standard angle gauge block to be measured. The beam reflected from the standard angle gauge block to be measured is imaged on the imaging detector 6, and the light spot can be moved to the center of the imaging detector 6 by adjusting the beam deflector. S102: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture so that the centers of the reflected light spots on the two test surfaces of the standard angle block fall on the horizontal central axis of the imaging detector 6. S103: Adjust the precision angular displacement micrometer of the first beam deflector 4a to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the left side of the test surface coincides with the center of the imaging detector 6, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position. a1 ; S104: Adjust the precision angular displacement micrometer of the second beam deflector 4b to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the right side of the test surface coincides with the center of the imaging detector 6, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position. b1 ; S105: Complete the calibration of the precision comparison and measurement device for tool angles; The measurement steps for the tool under test include the following steps: S201: Remove the standard angle gauge block and fix the tool to be tested on the mounting fixture 8 on the six-dimensional adjustment platform; adjust the XYZ adjustment knob of the mounting fixture 8 so that the two incident beams illuminate the center of the two cutting surfaces of the tool to be tested respectively. S202: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture 8 so that the centers of the reflected light spots on the left and right cutting surfaces of the tool under test fall on the horizontal central axis of the imaging detector 6. S203: When the left test surface of the tool under test has an angular deviation Δ relative to the left side of the calibration standard gauge block. a The right test surface of the tool under test has an angular deviation Δ relative to the right side of the calibration standard gauge block. b The angular deviation caused the reflected beam to deflect, and the light spot deviated from the center of the imaging detector 6; S204: Adjust the micrometer of the precision angular displacement of the first beam deflector 4a to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the left side of the test blade returns to the center of the imaging detector 6, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position at this time. a2 ; angular deviation Δ a Satisfying the formula: ; S205: Adjust the precision angular displacement micrometer of the second beam deflector 4b to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the right side of the test blade returns to the center of the imaging detector 6, and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position at this time. b2 ; angular deviation Δ b Satisfying the formula: ; S206: The nominal angle β and angle deviation Δ are determined according to the calibration standard angle gauge block. a Δ b The actual tool angle θ of the tool under test is calculated using the following formula: .

[0037] A standard angle gauge block with an angle similar to that of the tool to be tested is selected for calibration, so that the rotating double optical wedge beam deflector can complete self-collimation aiming without large-angle rotation.

[0038] Furthermore, the single-mode semiconductor laser in the aforementioned laser emission module 1 outputs unpolarized monochromatic light, which, after being collimated by the collimating objective lens, forms a highly collimated and stable parallel beam with a diameter of less than 1 mm. The focal length of the collimating objective lens is matched with the output spot of the laser, ensuring that the spot diameter when the beam is incident on the cutting edge is smaller than the cutting edge size. The operating wavelength of the laser can be selected according to the detection requirements and the material properties of the component under test.

[0039] The aforementioned cubic beam splitter 2 divides the incident beam into two orthogonal beams. The splitting ratio is determined based on the energy requirements of the two optical paths, preferably 50:50. The right-angle reflecting prism 3 deflects the transmitted beam of the cubic beam splitter 2 by 90°, making it parallel to the reflected beam of the cubic beam splitter 2. This ensures that the two beams are symmetrically distributed when incident on the tool and provides a stable incident angle for the beam deflector.

[0040] The first beam deflector 4a and the second beam deflector 4b described above, in their rotating double-wedge structure, are made of K9 optical glass or fused silica material. The wedge angle α and refractive index n are determined according to the measurement accuracy requirements and the beam wavelength. The two wedges rotate relative to each other at the same speed but in opposite directions, and the relative rotation angle is read by a precision angular displacement micrometer. Utilizing the angular displacement optical lever principle of the rotating double wedges, that is, when the first and second wedges rotate towards each other and produce a large relative rotation angle change, only a small beam deflection angle change is produced, thereby improving the sensitivity of the aiming beam deflection adjustment.

[0041] The first reflecting element 5a and the second reflecting element 5b mentioned above are high-reflectivity plane mirrors, mounted on a rotatable adjustment base. By rotating the mirror angle, coarse adjustment of the entire optical path is achieved, and precise adjustment of the optical path is completed in conjunction with a rotating double-wedge beam deflector, ensuring that after the laser beam is perpendicularly incident on the surface to be measured, the reflected beam is imaged at the center of the imaging detector 6. The adjustment range of the mirrors is determined according to the measurement angle range, adapting to the measurement needs of tools at different angles.

[0042] The aforementioned imaging detector 6 employs a large-area, high-resolution CCD or CMOS imaging sensor to acquire the position of the reflected light spot on the surface under test in real time. The image processing system 7 processes and calculates the light spot image acquired by the imaging detector 6, displays the light spot image and position offset information, and transmits the light spot position data to the data processing unit 9. The data processing unit 9 calculates the angular deviation of the surface under test according to the double-wedge deflection angle formula based on the light spot position information and the relative rotation angle data of the double-wedge, and then calculates the actual cutting angle of the tool under test.

[0043] In the six-dimensional adjustment mechanism of the aforementioned mounting fixture 8, the three translational degrees of freedom along the X, Y, and Z axes are used to adjust the spatial position of the tool under test, and the three rotational degrees of freedom φx, φy, and φz around the X, Y, and Z axes are used to adjust the pitch attitude of the tool under test, ensuring that both test surfaces are perpendicular to the dual-beam optical axis plane. Each adjustment axis is equipped with a precision micrometer, enabling micrometer-level translational adjustment and arcsecond-level rotational adjustment.

[0044] This invention employs a comparative measurement method to achieve precise measurement of tool angles. During calibration, a standard angle gauge block with an angle close to that of the tool under test is selected, allowing the rotating double-wedge beam deflector to achieve self-collimation aiming without large-angle rotation. During measurement, if there is an angular deviation between the cutting surface of the tool under test and the standard gauge block, the reflected light spot will deviate from the center of the imaging detector 6. By adjusting the relative rotation angle of the double-wedge, the light spot is brought back to the center. The angle deviation is calculated from the change in the relative rotation angle according to the double-wedge deflection angle formula, thereby obtaining the actual tool angle of the tool under test. The parameter configuration of the aforementioned precision angular displacement micrometer, single-mode semiconductor laser, collimating objective lens, and imaging detector 6 enables the device to achieve a beam deflection accuracy of ±0.005° and a tool angle measurement accuracy of ±0.01°, meeting the high-precision requirements of ultra-precision machining of optical micro-pyramidal master molds.

[0045] With the laser emission module 1 output beam spot size, imaging detector 6 resolution and mounting fixture 8 adjustment capability combined, the device can detect workpieces as small as 1.2mm in size, and is suitable for detecting micro-tools with a size ≤5mm. It is applicable to high-precision detection scenarios of cutting edge angles of diamond tools, metal tools and opaque infrared optical elements such as germanium, silicon, and zinc selenide.

[0046] In other embodiments, the optical wedge material can also be infrared optical materials such as calcium fluoride and zinc selenide to adapt to the detection requirements of different wavelengths; the imaging detector 6 can also use other types of optoelectronic components, as long as they can acquire the position of the reflected light spot on the surface under test in real time. The specific models of the above-mentioned optical components are conventional choices in the art and can be purchased commercially, and will not be described in detail here.

[0047] The working principle of this invention is as follows: The parallel beam output from the laser emitting module 1 is split into two orthogonal beams by the cubic beam splitter 2. The transmitted beam is deflected by 90° by the right-angle reflecting prism 3 and becomes parallel to the reflected beam. The two beams are precisely adjusted for beam deflection angle by the first beam deflector 4a and the second beam deflector 4b, respectively, and then guided to the two cutting surfaces of the tool under test by the first reflecting element 5a and the second reflecting element 5b. After the beam is perpendicularly incident on the surface under test, the reflected beam returns along the original path and is imaged on the imaging detector 6 after being transmitted through the optical path system. If the angle of the surface under test changes, the position of the reflected spot will shift. By adjusting the relative rotation angle of the two optical wedges to bring the spot back to the center of the imaging detector 6, the angular deviation of the surface under test can be calculated from the relative rotation angle of the two optical wedges.

[0048] To further verify the feasibility of this measuring device and method: Taking a commonly used cutting tool with a nominal value of 70.53° as an example, this embodiment uses a standard angle gauge block with a nominal angle of 71° for calibration.

[0049] (1) Before testing, install a 71° standard angle block, adjust the angle between the laser reflector and the vertical optical axis to around 27.25° and fix it so that the reflected beams from the two test surfaces of the standard angle block enter the imaging detector for imaging.

[0050] (2) Adjust the pitch adjustment knob of the mounting fixture to adjust the pitch attitude of the standard angle gauge block so that the reflected beams from both test surfaces are imaged on the horizontal central axis of the detector. Then, adjust the relative rotation angle of the rotating double-wedge deflectors on the two optical paths so that the reflected beams from both test surfaces are imaged at the center of the imaging detector. Record the relative rotation angle value ψ of the two rotating double-wedge deflectors at this time. a1 and ψ b1 .

[0051] (3) Remove the 71° standard angle block, install and fix the tool to be tested, and adjust the pitch adjustment knob of the mounting fixture to adjust the pitch attitude of the tool to be tested so that the reflected beams of the two surfaces to be tested are imaged on the horizontal central axis of the detector.

[0052] (4) Adjust the relative rotation angle of the rotating double-wedge deflectors on the two optical paths respectively, so that the reflected beams from the two surfaces under test are imaged at the center of the imaging detector. Record the relative rotation angle value ψ of the two rotating double-wedge deflectors at this time. a2 and ψ b2 .

[0053] (5) According to the double wedge deflection angle formula, the relative rotation angle ψ a1 ψ a2 Calculate the angular deviation Δ of the left side of the surface to be measured. a Due to the relative rotation angle ψ b1ψ b2 Calculate the angular deviation Δ of the right side of the surface to be measured. b Then, the actual cutting angle of the tool under test is calculated: θ = 71° - Δ a -Δ b .

[0054] Furthermore, the measurement angle range of this invention is not limited to small angles; devices with different angle measurement ranges can be designed as needed. By adjusting the deflection angle of the laser reflector, a wide range of control over the incident beam deflection angle can be achieved, thereby adapting to various measurement angle requirements. Calibration can be completed with standard angle gauge blocks of different specifications, ultimately achieving high-precision comparative measurement within a large angle range. In addition, the device structure of this invention is also applicable to the edge angle detection of opaque infrared optical elements such as germanium, silicon, and zinc selenide; only the optical wedge material needs to be replaced with an optical material adapted to the corresponding wavelength band.

[0055] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A precision measuring device for the angle of cutting tools used in the machining of micro-pyramidal molds, characterized in that, include: A laser emitting module (1) is used to output a parallel beam with high collimation. The laser emitting module (1) includes a single-mode semiconductor laser and a collimating objective lens. The diameter of the parallel beam output by the laser emitting module (1) is less than 1 mm, and the diameter of the spot when the beam is incident on the cutting edge of the tool is smaller than the size of the cutting edge. A cubic beam splitter (2) is disposed on the outgoing optical path of the laser emitting module (1) to split the incident beam into a first beam and a second beam, wherein the first beam and the second beam are parallel to each other. The first beam deflector (4a) and the second beam deflector (4b) are respectively disposed on the optical paths of the first beam and the second beam. The first beam deflector (4a) and the second beam deflector (4b) both adopt a rotating double optical wedge structure and are each equipped with a precision angular displacement micrometer. The first reflective element (5a) and the second reflective element (5b) are respectively set to correspond to two optical paths, and are used to guide the beams emitted by the first beam deflector (4a) and the second beam deflector (4b) to the first test surface and the second test surface of the tool under test, respectively. An imaging detector (6) is disposed on the reflected light path of the first test surface and the second test surface, and is used to receive the reflected light from the first test surface and the second test surface and form a light spot image. The image processing system (7) is electrically connected to the imaging detector (6) and is used to process the spot image and display the spot position information; The mounting fixture (8) is used to install and fix the tool to be tested or the standard angle gauge block. The mounting fixture (8) is equipped with a six-dimensional adjustment mechanism. The data processing unit (9) is used to calculate the blade angle of the tool under test based on the spot position information of the imaging detector (6); The tool angle is precisely measured by comparing the difference in the position of the light spot caused by the tool under test and the standard angle gauge block.

2. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: It also includes a right-angle reflecting prism (3); the right-angle reflecting prism (3) is disposed on the transmission light path of the cubic beam splitter (2) to deflect the transmitted beam of the cubic beam splitter (2) by 90° so that the transmitted beam and the reflected beam of the cubic beam splitter (2) are parallel to each other.

3. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: The rotating double optical wedge structure includes a first optical wedge and a second optical wedge. Both the first and second optical wedges have a wedge angle of α and a refractive index of n. The two wedges rotate relative to each other with the same angular velocity but opposite rotational directions. Taking the relative rotation angle relative to the zero reference position as ψ, the total deflection angle δ after beam transmission is calculated using the following formula: ； When the main cross sections of the first and second optical wedges are in the same direction, the thick side is located on the right side, and the relative rotation angle ψ=0°, the beam deflects to the right to the maximum value. When the cross-sections of the first and second optical wedges are opposite to each other and the relative rotation angle ψ = 90°, the beam deflection angle is equal to 0. When the main cross-sections of the first and second optical wedges are in the same direction and the thick side is on the left, the beam deflects to the left to its maximum value when the relative rotation angle ψ = 180°.

4. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 3, characterized in that: The first beam deflector (4a) and the second beam deflector (4b) output a small beam deflection angle change through a large relative rotation angle change, so that after the detection beam is incident on the side of the test surface, the reflected light from the test surface can return along the incident light path and be imaged at the center of the imaging detector (6) after being transmitted through the detection system.

5. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: By adjusting the deflection angles of the first reflective element (5a) and the second reflective element (5b), a wide range of control over the incident beam deflection angle can be achieved to adapt to the measurement requirements of different angles of the tool, so that the laser beam is perpendicularly incident on the surface to be measured and the reflected beam is imaged at the center of the imaging detector (6).

6. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: The imaging detector (6) is a CCD or CMOS imaging sensor.

7. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: The parameter configuration of the precision angular displacement micrometer, single-mode semiconductor laser, collimating objective lens and imaging detector (6) enables the device to achieve a beam deflection accuracy of ±0.005° and a knife angle measurement accuracy of ±0.01°.

8. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: The six-dimensional adjustment mechanism of the mounting fixture (8) includes three translational degrees of freedom along the X, Y, and Z axes and three rotational degrees of freedom (φx, φy, φz) around the X, Y, and Z axes, which are used to adjust the posture of the tool to be tested.

9. The precision measuring device for the angle of the micro-pyramidal mold processing tool according to claim 1, characterized in that: The laser emission module (1) outputs a beam spot size, the imaging detector (6) has a resolution that is matched with the adjustment capability of the mounting fixture (8). The device can detect workpieces with a minimum size of 1.2mm and is suitable for detecting micro-tools with a size of ≤5mm.

10. A method for precisely measuring the angle of a cutting tool in the machining of a micro-pyramidal mold, characterized in that, The micro-pyramidal mold machining tool angle precision measuring device according to claim 1 includes a system calibration step and a tool measurement step; The system calibration step uses a standard angle gauge block to complete the device calibration. This standard angle gauge block enables the first beam deflector (4a) and the second beam deflector (4b) to complete autocollimation aiming without large-angle rotation. The steps include the following: S101: Fix the standard angle gauge block to the mounting fixture (8); adjust the rotation angle of the first reflective element (5a) and the second reflective element (5b), adjust the XYZ adjustment knob of the mounting fixture, so that the incident beam illuminates the center of the standard angle gauge block to be measured, the beam reflected from the standard angle gauge block to be measured is imaged on the imaging detector (6), and the light spot can be moved to the center of the imaging detector (6) by adjusting the beam deflector. S102: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture so that the center of the reflected light spot on the left and right sides of the standard angle gauge block falls on the horizontal central axis of the imaging detector (6); S103: Adjust the precision angular displacement micrometer of the first beam deflector (4a) to change the relative rotation angle of the double optical wedges, so that the center of the reflected light spot on the left side of the test surface coincides with the center of the imaging detector (6), and record the rotation angle ψ of the main section of the single optical wedge relative to the reference zero position. a1 ; S104: Adjust the precision angular displacement micrometer of the second beam deflector (4b) to change the relative rotation angle of the double optical wedges, so that the center of the reflected light spot on the right side of the test surface coincides with the center of the imaging detector (6), and record the rotation angle ψ of the main section of the single optical wedge relative to the reference zero position. b1 ; S105: Complete the calibration of the precision comparison and measurement device for tool angles; The measurement steps for the tool under test include the following steps: S201: Remove the standard angle gauge block and fix the tool to be tested on the mounting fixture (8) on the six-dimensional adjustment platform; adjust the XYZ adjustment knob of the mounting fixture (8) so that the two incident beams respectively illuminate the center of the two cutting surfaces of the tool to be tested; S202: Adjust the φx, φy, and φz adjustment knobs of the mounting fixture (8) so that the center of the reflected light spot on both the left and right sides of the cutting edge to be tested falls on the horizontal central axis of the imaging detector (6); S203: When the left test surface of the tool under test has an angular deviation Δ relative to the left side of the calibration standard gauge block. a The right test surface of the tool under test has an angular deviation Δ relative to the right side of the calibration standard gauge block. b The angle deviation causes the reflected beam to deflect, and the light spot deviates from the center of the imaging detector (6); S204: Adjust the precision angular displacement micrometer of the first beam deflector (4a) to change the relative rotation angle of the two optical wedges, so that the center of the reflected light spot on the left side of the blade to be measured returns to the center of the imaging detector (6), and record the rotation angle ψ of the main section of a single optical wedge relative to the reference zero position at this time. a2 ; angular deviation Δ a Satisfying the formula: ； S205: Adjust the precision angular displacement micrometer of the second beam deflector (4b) to change the relative rotation angle of the double wedges, so that the center of the reflected light spot on the right side of the blade surface to be measured returns to the center of the imaging detector (6), and record the rotation angle ψ of the main section of a single wedge relative to the reference zero position at this time. b2 ; angular deviation Δ b Satisfying the formula: ； S206: The nominal angle β and angle deviation Δ are determined according to the calibration standard angle gauge block. a Δ b The actual tool angle θ of the tool under test is calculated using the following formula: .

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