Vertical surface roughness probe and surface roughness instrument

Abstract

The present invention discloses a vertical surface roughness probe and a surface roughness meter. The vertical surface roughness probe includes a fixed frame, a movable frame, a displacement measurement module, a stylus bar, a stylus, and a guiding device. The movable frame is vertically slidably connected to the fixed frame. A stylus bar is provided on the movable frame. A guiding device is provided on the bottom plate of the movable frame. The guiding device can be used to vertically guide the stylus bar to prevent the stylus bar from swinging. A stylus is fixedly provided at the bottom end of the stylus bar. The stylus bar passes through the guiding device, and the stylus penetrates through the bottom plate of the movable frame. The displacement measurement module is used to measure the moving distance of the stylus bar in the vertical direction; the surface roughness meter includes a frame body, a moving device, and the above-mentioned vertical surface roughness probe. In the present invention, under the action of the guiding device, the stylus and the stylus bar are always perpendicular to the surface of the workpiece during the measurement process, with simple operation and high measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of measuring devices, and particularly to a vertical surface roughness probe and a surface roughness meter. Background Art

[0002] Surface roughness is a technical index used to describe the microscopic geometric shape error of parts, and is also an important method for evaluating machining processes. In manufacturing fields such as precision machinery, instruments, and ultra-precision machining, surface roughness is an important parameter, and the research on its measurement theory and the development of measurement instruments have always been the key concerns of people.

[0003] In the prior art, a lever-type stylus roughness measuring instrument is generally used. The measurement principle is that after the stylus moves relative to the surface of the workpiece to be measured, the stylus fluctuates vertically with the surface undulation of the workpiece to be measured, and then a sensor is used to measure this small undulation. After signal processing, the surface information of the workpiece to be measured is finally obtained. However, due to the measurement structure characteristics of the lever stylus roughness measuring instrument, there is an inevitable cosine error when measuring the surface height undulation change, which ultimately affects the overall accuracy of the roughness measuring instrument. Although this systematic error can be compensated by some means such as an angle sensor, in the field of nano-measurement, this is still an inevitable error, and it will introduce more uncertainties when evaluating the overall uncertainty of the instrument, and the system noise is also relatively large. Summary of the Invention

[0004] The purpose of the present invention is to provide a vertical surface roughness probe and a surface roughness meter to solve the problems existing in the above prior art, and to make the device easy to operate and highly accurate in measurement.

[0005] To achieve the above purpose, the present invention provides the following solution:

[0006] The present invention provides a vertical surface roughness probe, which includes a fixed frame, a moving frame, a displacement measurement module, a stylus rod, a stylus, and a guiding device. The moving frame is vertically slidably connected to the fixed frame. The moving frame includes a top plate, a vertical plate, and a bottom plate. The two ends of the vertical plate are respectively fixedly connected to the top plate and the bottom plate. The top end of the stylus rod is elastically connected to the top plate. The guiding device is arranged on the bottom plate, and the guiding device can be used to vertically guide the stylus rod to prevent the stylus rod from swinging. The bottom end of the stylus rod is fixedly provided with the stylus. The stylus rod passes through the guiding device, and the stylus penetrates through the bottom plate. The displacement measurement module is used to measure the moving distance of the stylus rod in the vertical direction.

[0007] Preferably, the displacement measurement module includes a reflection part and a laser interferometer. The reflection part is a silver-plated layer fixedly arranged at the top end of the needle rod. The reflection part is perpendicular to the central axis of the needle rod, and the optical path center of the laser interferometer coincides with the central axis of the needle rod.

[0008] Preferably, the guiding device includes a vertical reference module. A plurality of guiding hemispheres are arranged on the needle rod in the circumferential direction. The vertical reference module includes a plurality of sliders. The number of the sliders is the same as that of the guiding hemispheres. The inner wall of each slider is provided with a V-shaped groove. Both side walls of each V-shaped groove are in point contact with one guiding hemisphere. At least one positioning pin is arranged on the bottom plate of the moving frame, and at least one slider is provided with a positioning hole and the positioning pin can extend into the positioning hole.

[0009] Preferably, a diaphragm is fixedly arranged on the bottom surface of the top plate, and the top end of the needle rod is bonded to the center of the diaphragm through an epoxy resin thin layer.

[0010] Preferably, it includes a pressure control module. The pressure control module includes a distance adjusting device and a pressure sensor. The distance adjusting device is fixedly arranged on the fixed frame. The distance adjusting device is arranged vertically. The distance adjusting device adjusts the distance between the stylus and the surface of the workpiece to be measured by finely adjusting the moving frame in the vertical direction. The bottom end of the distance adjusting device abuts against the upper surface of the top plate. The pressure sensor is arranged below the product to be measured for monitoring the pressure received by the sample to be measured.

[0011] Preferably, the elastic connecting member is a spring. The spring is in a stretched state. Each spring is arranged vertically and each spring is symmetrically arranged with respect to the distance adjusting device.

[0012] Preferably, the distance adjusting device is a depth micrometer. The micrometer screw of the depth micrometer abuts against the top plate, and the frame of the depth micrometer is fixedly connected to the fixed frame.

[0013] Preferably, a connecting block is arranged on the upper surface of the top plate, and the micrometer screw of the depth micrometer abuts against the connecting block.

[0014] Preferably, each slider is provided with a sliding groove, and a sliding bar is arranged between two adjacent sliders. One end of the sliding bar is fixedly connected to one slider, and the other end of the sliding bar is slidably connected to another sliding groove. The outer side wall of each slider is a curved surface and has the same radius of curvature. By moving the sliding bar along the sliding groove, the slider without the positioning hole can be moved along the radial direction of the needle rod.

[0015] The present invention also provides a surface roughness meter, which includes a frame body, a moving device, and the vertical surface roughness probe according to any one of the above, wherein the fixing frame is connected to the frame body, the moving device is fixedly arranged on the frame body, and the moving device can drive the fixing frame to move horizontally.

[0016] The present invention has achieved the following technical effects compared with the prior art:

[0017] The present invention provides a vertical surface roughness probe and a surface roughness meter, which are provided with a fixing frame, a moving frame, a needle rod, a stylus, and a guiding device. The moving frame is vertically slidably connected to the fixing frame. When measuring the surface roughness of a workpiece to be measured, the height of the moving frame can be adjusted up and down according to the size of the workpiece to be measured. After the adjustment is in place and the relative position of the moving frame and the fixing frame is fixed, the measurement can be started. The operation is simple. The top end of the needle rod is elastically connected to the top plate. The surface roughness of the workpiece to be measured is calculated by measuring the distance of the up and down movement of the needle rod. The guiding device can be used to vertically guide the needle rod to prevent the needle rod from swinging, so that during the measurement, the needle rod and the stylus are always vertically arranged. Macroscopically, it is perpendicular to the detection surface of the horizontally arranged workpiece to be measured, with a low noise level and high measurement accuracy; the moving device on the surface roughness meter moves the fixing frame horizontally, and stops moving and returns to the original position after moving to a set distance. The operation is simple and the measurement accuracy is high.

[0018] Further, the displacement measurement module includes a reflection part and a laser interferometer. The reflection part is a silver-plated layer fixedly arranged at the top end of the needle rod. The reflection part is perpendicular to the center line of the needle rod. The optical path center of the laser interferometer coincides with the center line of the needle rod. The laser interferometer not only has high measurement accuracy but also fast measurement speed, and can quickly give the roughness measurement result in cooperation with the calculation software.

[0019] Further, the guiding device includes a vertical reference module. A plurality of guiding hemispheres are arranged on the needle rod along the circumferential direction. The vertical reference module includes a plurality of sliders. The number of sliders is the same as the number of guiding hemispheres. The inner wall of each slider is provided with a V-shaped groove. Both side walls of each V-shaped groove are in point contact with a guiding hemisphere. The point contact has small friction, so that each slider basically does not hinder the up and down movement of the needle rod, ensuring the measurement accuracy. At least one positioning pin is arranged on the bottom plate of the moving frame, and at least one positioning hole is arranged on one slider and the positioning pin can extend into the positioning hole, so that the positions of the sliders can be fixed, and even after disassembly and reassembly, it can be ensured that the needle rod is perpendicular to the bottom plate of the moving frame.

[0020] Further, a diaphragm is fixedly arranged on the bottom surface of the top plate. The top end of the needle rod is bonded to the center of the diaphragm through an epoxy resin thin layer. The needle rod is connected to the moving frame through the diaphragm and epoxy resin is used as the adhesive. The epoxy resin has strong adhesion, is not easily deformed due to temperature change, and does not affect light transmission.

[0021] Further, the pressure control module includes a distance adjustment device and a pressure sensor. The distance adjustment device is vertically arranged. The distance adjustment device adjusts the distance between the stylus and the surface of the workpiece to be measured by finely adjusting the moving frame in the vertical direction. The bottom end of the distance adjustment device abuts against the upper surface of the top plate. The pressure sensor is arranged below the product to be measured to monitor the pressure exerted on the sample to be measured. When measuring the roughness of a workpiece with a relatively soft surface material, if the pressure received is too large, it is easily scratched. The distance adjustment device can finely adjust the distance between the stylus and the workpiece surface according to the pressure value indicated by the pressure sensor, change the elastic deformation amount of the connection structure between the stylus rod and the top plate, adjust the pressure received by the workpiece, and prevent scratching.

[0022] Further, the elastic connecting member is a spring. The spring is in a stretched state. Each spring is vertically arranged and each spring is symmetrically arranged with respect to the distance adjustment device. The spring has strong elastic deformation ability and low price, and moreover, each spring is symmetrically arranged, and the force application points are evenly distributed, which can ensure the stability and balance of the moving frame.

[0023] Further, the distance adjustment device is a depth micrometer. The micrometer screw of the depth micrometer abuts against the top plate. The frame of the depth micrometer is fixedly connected to the fixed frame. The depth micrometer is a common detection tool, which is convenient and easy to obtain. Moreover, because the pressure on the workpiece surface is very small, a slight adjustment may exceed the range. The depth micrometer has high adjustment accuracy and can quickly adjust the pressure received by the workpiece surface to the specified range without repeated adjustment.

[0024] Further, a connecting block is provided on the upper surface of the top plate. The micrometer screw of the depth micrometer abuts against the connecting block. The micrometer screw does not directly contact the moving frame. The micrometer screw and the connecting block rub against each other. The texture of the connecting block is relatively soft. After the connecting block is worn beyond the limit, the connecting block can be replaced.

[0025] Further, sliding grooves are provided on each slider. A sliding bar is provided between two adjacent sliders. Among two adjacent sliders, one end of the sliding bar is fixedly connected to one slider, and the other end of the sliding bar is slidably connected to another sliding groove. The outer side walls of each slider are all curved surfaces and have the same radius of curvature. When it is necessary to disassemble and assemble the stylus rod or manually adjust the position of the stylus rod, by moving the sliding bar along the sliding groove, the slider without a positioning hole can be moved radially along the stylus rod, which is convenient for operating the stylus rod. After completion, the above-mentioned slider can be pushed back to its original position. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Schematic diagram of the structure of the vertical surface roughness probe provided for Example 1;

[0028] Figure 2 Schematic diagram of the structure of the needle rod and the stylus provided for Example 1;

[0029] Figure 3 Schematic diagram of the structure of the vertical reference device provided for Example 1.

[0030] In the figure: 1 - fixing frame; 2 - moving frame; 3 - needle rod; 4 - stylus; 5 - vertical reference module; 6 - laser interferometer; 7 - guiding hemisphere; 8 - V-shaped groove; 9 - diaphragm; 10 - depth micrometer; 11 - connecting block; 12 - positioning hole; 13 - sliding groove; 14 - sliding bar. Specific embodiments

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] The purpose of the present invention is to provide a vertical surface roughness probe and a surface roughness instrument to solve the problems existing in the prior art and make the device easy to operate and highly accurate in measurement.

[0033] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] This example provides a vertical surface roughness probe, as Figures 1 to 3As shown, in this embodiment, the vertical surface roughness probe includes a fixed frame 1, a moving frame 2, a displacement measurement module, a stylus rod 3, a stylus 4 and a guiding device. The moving frame 2 is vertically slidably connected to the fixed frame 1. When measuring the surface roughness of a workpiece to be measured, the height of the moving frame 2 can be adjusted up and down according to the size of the workpiece to be measured. After the adjustment is in place and the relative position of the moving frame 2 and the fixed frame 1 is fixed, the measurement can be started. The operation is simple. The moving frame 2 includes a top plate, a vertical plate and a bottom plate. The two ends of the vertical plate are respectively fixedly connected to the top plate and the bottom plate. The top end of the stylus rod 3 is elastically connected to the top plate. The surface roughness of the workpiece to be measured is calculated by measuring the distance of the up and down movement of the stylus rod 3. A guiding device is provided on the bottom plate. The guiding device can be used to vertically guide the stylus rod to prevent the stylus rod 3 from swinging, so that during the measurement, the stylus rod 3 and the stylus 4 are always perpendicular to the surface of the workpiece to be measured macroscopically, improving the measurement accuracy. The bottom end of the stylus rod 3 is fixedly provided with a stylus 4. The stylus rod 3 passes through the guiding device, and the stylus 4 penetrates the bottom plate. The displacement measurement module 5 is used to measure the moving distance of the stylus rod 3 in the vertical direction.

[0036] Further, the displacement measurement module includes a reflection part and a laser interferometer 6. The reflection part is a silver-plated layer fixedly provided at the top end of the stylus rod 3. The reflection part is perpendicularly arranged with the center line of the stylus rod 3. The optical path center of the laser interferometer 6 coincides with the center line of the stylus rod 3. The laser interferometer emits a ray, and the ray is reflected after reaching the reflection part and received by the receiving device. The laser interferometer 6 not only has high measurement accuracy and fast measurement speed, but also can quickly give the roughness measurement result in cooperation with the calculation software.

[0037] Further, the guiding device includes a vertical reference module 5. A plurality of guiding hemispheres 7 are arranged on the stylus rod 3 along the circumferential direction. The vertical reference module 5 includes a plurality of sliders. The number of sliders is the same as the number of guiding hemispheres 7. The inner wall of each slider is provided with a V-shaped groove 8. Both side walls of each V-shaped groove 8 are in point contact with a guiding hemisphere 7. The point contact has small friction, so that each slider basically does not hinder the up and down movement of the stylus rod 3, ensuring the measurement accuracy. At least one positioning pin is provided on the bottom plate of the moving frame 2. At least one positioning hole 12 is provided on one slider and the positioning pin can extend into the positioning hole 12, so that the positions of the sliders can be fixed, and even if disassembled and reassembled, it can be ensured that the stylus rod 3 is perpendicular to the bottom plate of the moving frame 2.

[0038] Further, a diaphragm 9 is fixedly provided on the bottom surface of the top plate. The top end of the stylus rod 3 and the center of the diaphragm 9 are bonded by an epoxy resin thin layer. The stylus rod 3 and the moving frame 2 are connected through the diaphragm and epoxy resin is used as the adhesive. The epoxy resin has strong adhesion, is not easily deformed due to temperature change, and does not affect light transmission.

[0039] Further, it includes a pressure control module. The pressure control module includes a distance adjustment device and a pressure sensor. The distance adjustment device is fixedly arranged on the fixing frame 1. The distance adjustment device is arranged vertically. The distance adjustment device finely adjusts the moving frame 2 to adjust the distance between the stylus 4 and the surface of the workpiece to be measured. The bottom end of the distance adjustment device abuts against the upper surface of the top plate. The pressure sensor is arranged below the product to be measured to monitor the pressure received by the sample to be measured. When measuring the roughness of a workpiece with a relatively soft surface material, if the pressure received is too large, it is easily scratched. The distance adjustment device can finely adjust the distance between the stylus 4 and the workpiece surface according to the pressure value indicated by the pressure sensor, change the elastic deformation amount of the connection structure between the needle bar 3 and the top plate, adjust the pressure received by the workpiece, and prevent scratching.

[0040] Further, the elastic connecting member is a spring. The spring is in a stretched state. Each spring is arranged vertically and each spring is symmetrically arranged with respect to the distance adjustment device. The spring has strong elastic deformation ability and low price. Moreover, each spring is symmetrically arranged and the stress points are evenly distributed, which can ensure the stability and balance of the moving frame.

[0041] Further, the distance adjustment device is a depth micrometer 10. The micrometer screw of the depth micrometer 10 abuts against the top plate. The frame of the depth micrometer is fixedly connected to the fixing frame 1. The depth micrometer 10 is a common detection tool, which is convenient and easy to obtain. Moreover, because the pressure on the workpiece surface is very small, only 0.75 mN to 1 mN, a slight adjustment may exceed the range. The adjustment accuracy of the depth micrometer 10 is high, which is convenient to quickly adjust the pressure received by the workpiece surface to the specified range without repeated adjustment, and the adjustment efficiency is high.

[0042] Further, a connecting block 11 is provided on the upper surface of the top plate. The micrometer screw of the depth micrometer abuts against the connecting block 11. The micrometer screw does not directly contact the moving frame 2. The micrometer screw and the connecting block 11 rub against each other. The texture of the connecting block 11 is relatively soft. After the connecting block 11 is worn out beyond the limit, the connecting block 11 can be replaced.

[0043] Further, sliding grooves 13 are provided on each slider. A sliding bar 14 is provided between two adjacent sliders. One end of the sliding bar 14 is fixedly connected to one slider, and the other end of the sliding bar 14 is slidably connected to another sliding groove 13. The outer side walls of each slider are all curved surfaces and have the same radius of curvature. When it is necessary to disassemble and assemble the needle bar 3 or manually adjust the position of the needle bar 3, the slider without the positioning hole 12 is moved radially along the needle bar 3 by moving the sliding bar 14 along the sliding groove 13, which is convenient for operating the needle bar 3. After completion, the above-mentioned slider is pushed back to its original position.

[0044] Embodiment 2

[0045] This embodiment provides a surface roughness meter. In this embodiment, the surface roughness meter includes a frame body, a moving device, and the vertical surface roughness probe of Embodiment 1. The fixing frame 1 is slidably connected to the frame body. A moving device is fixedly arranged on the frame body. The moving device can drive the fixing frame 1 to slide horizontally, thereby driving the vertical surface roughness probe to move horizontally. And after moving to a set distance, it stops moving and returns to its original position, with simple operation and high measurement accuracy.

[0046] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A vertical surface roughness probe, characterized in that: It includes a fixed frame, a moving frame, a displacement measurement module, a needle rod, a stylus, and a guiding device. The moving frame is vertically slidably connected to the fixed frame. The moving frame includes a top plate, vertical plates, and a bottom plate. The two ends of the vertical plates are respectively fixedly connected to the top plate and the bottom plate. The top end of the needle rod is elastically connected to the lower surface of the top plate. The guiding device is provided on the bottom plate and can be used to vertically guide the needle rod to prevent the needle rod from swinging. The stylus is fixedly provided at the bottom end of the needle rod. The needle rod passes through the guiding device, and the stylus penetrates through the bottom plate. The displacement measurement module is used to measure the moving distance of the needle rod in the vertical direction. The displacement measurement module includes a reflection part and a laser interferometer. The reflection part is a silver-plated layer fixedly provided at the top end of the needle rod, and the reflection part is perpendicularly arranged with respect to the central axis of the needle rod. The optical path center of the laser interferometer coincides with the central axis of the needle rod. The guiding device includes a vertical reference module. A plurality of guiding hemispheres are provided on the needle rod in the circumferential direction. The vertical reference module includes a plurality of sliders. The number of sliders is the same as the number of guiding hemispheres. The inner wall of each slider is provided with a V-shaped groove, and both side walls of each V-shaped groove are in point contact with one guiding hemisphere. At least one positioning pin is provided on the bottom plate of the moving frame, and at least one slider is provided with a positioning hole and the positioning pin can extend into the positioning hole.

2. The vertical surface roughness probe according to claim 1, characterized in that: A diaphragm is fixedly provided on the bottom surface of the top plate, and the top end of the needle rod is adhesively bonded to the center of the diaphragm through an epoxy resin film.

3. The vertical surface roughness probe according to claim 1, wherein: It includes a pressure control module. The pressure control module includes a distance adjusting device and a pressure sensor. The distance adjusting device is fixedly provided on the fixed frame. The distance adjusting device is vertically arranged and adjusts the distance between the stylus and the surface of the workpiece to be measured by finely adjusting the moving frame in the vertical direction. The bottom end of the distance adjusting device abuts against the upper surface of the top plate. The pressure sensor is arranged below the product to be measured to monitor the pressure received by the sample to be measured.

4. The vertical surface roughness probe according to claim 3, characterized in that: The top end of the needle rod is connected to the lower surface of the top plate through an elastic connecting member. The elastic connecting member is a spring. The spring is in a stretched state. Each spring is vertically arranged and each spring is symmetrically arranged with respect to the distance adjusting device.

5. The vertical surface roughness probe according to claim 3, characterized in that: The distance adjusting device is a depth micrometer. The micrometer screw of the depth micrometer abuts against the top plate, and the frame of the depth micrometer is fixedly connected to the fixed frame.

6. The vertical surface roughness probe according to claim 5, characterized in that: A connecting block is provided on the upper surface of the top plate, and the micrometer screw of the depth micrometer abuts against the connecting block.

7. The vertical surface roughness probe according to claim 1, characterized in that: Each slider is provided with a sliding groove. A sliding bar is provided between two adjacent sliders. Among two adjacent sliders, one end of the sliding bar is fixedly connected to one slider, and the other end of the sliding bar is slidably connected to the other sliding groove. The outer side wall of each slider is a curved surface and has the same radius of curvature. By moving the sliding bar along the sliding groove, the slider without the positioning hole can be moved radially along the needle rod.

8. A surface roughness meter, characterized in that: It includes a frame body, a moving device, and the vertical surface roughness probe according to any one of claims 1 to 7. The fixing frame is connected to the frame body, the moving device is fixedly arranged on the frame body, and the moving device can drive the fixing frame to move horizontally.

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