Device for grinding and polishing side surface of plate-shaped tensile sample

Abstract

The invention relates to the field of plate-shaped tensile mechanical test experiments, in particular to a device for grinding and polishing the side surface of a plate-shaped tensile sample. A Y-axis guide rail and a Z-axis guide rail of the device are assembled on a base, an X-axis guide rail is assembled on a Y-axis guide rail sliding block on the Y-axis guide rail, a sample to be polished is arranged on an X-axis guide rail sliding block on the X-axis guide rail, a spindle motor used for installing a polishing head is assembled on a Z-axis guide rail sliding block on the Z-axis guide rail, and an XYZ three-axis movement system is formed. The X-axis guide rail, the Y-axis guide rail and the Z-axis guide rail are provided with corresponding servo motors respectively, and free movement of the X axis, the Y axis and the Z axis is achieved. The automatic grinding device is simple in structure and convenient to operate, solves the problems that after the plate-shaped tensile sample is subjected to wire cut electrical discharge machining, the manual grinding size precision of the side surface is not enough, and the roughness cannot meet the test standard, achieves the automatic grinding effect, and improves the experimental test precision of the plate-shaped mechanical tensile sample.

Description

Technical Field

[0001] The invention relates to the field of plate-shaped tensile mechanics testing experiments, in particular to a device for grinding and polishing the side surface of a plate-shaped tensile specimen. Background Art

[0002] Plate tensile specimens are a commonly used method for testing the mechanical properties of metals. They are used to determine the deformation and strength of materials under tensile stress and are often used for quality control and research of metal materials. When preparing plate tensile specimens, the influence of specifications and processing technology must be considered to ensure the quality and reliability of the specimens.

[0003] According to GB / T 228-2021 "Tension Tests on Metallic Materials," the original cross-sectional area of ​​plate tensile specimens should be calculated based on the measured specimen dimensions. The original cross-sectional area should be determined with an accuracy of ±2%. When the error is primarily due to the specimen thickness, the width measurement error should not exceed ±0.2%. To reduce the uncertainty of the test measurement results, it is recommended that the original cross-sectional area be accurate to or better than ±1%. The specimen's transverse dimensional tolerance should meet ±0.02 to 0.1 mm, depending on the lateral dimensional ratio. The specimen's transverse shape tolerance should meet 0.03 to 0.05 mm, depending on the lateral dimensional ratio (see Table G.4, Transverse Dimensional Tolerances of Specimens, GB / T 228-2021 "Tension Tests on Metallic Materials" for details). Specimen preparation should not affect its mechanical properties. Materials exhibiting significant work hardening are typically processed by milling or grinding (see E.4, Preparation of Specimens, GB / T 228-2021 "Tension Tests on Metallic Materials" for details).

[0004] With the development of metal materials science and technology, more and more high-performance materials have been developed. However, due to the limitations of traditional physical cutting methods such as milling and grinding, such as tool strength, wear resistance, and processing costs, more and more researchers are choosing wire-cutting (EDM), a method of high-temperature vaporization of local metals, to process plate tensile specimens. Its advantages are: regardless of the strength and hardness of the material being processed, it can be processed as long as it is conductive, and the processing dimensions are precise and the cost is low. However, its disadvantages are: after processing, a thin high-temperature oxide layer and heat-affected zone will appear on the surface of the specimen. The structural properties of the oxide layer material are different from those of the test material, and the oxide layer needs to be polished off before testing to ensure the accuracy of the test data. The grinding of plate tensile specimens is divided into upper and lower surfaces and side surfaces. The upper and lower surfaces are both flat structures and can be quickly processed using milling machines or surface grinders. The transition arcs and parallel sections on both sides of the surface also need to be polished, requiring contour grinding. Currently, there is a lack of such contouring equipment in the field, and various research institutions use manual grinding to process the side surfaces of plate tensile specimens.

[0005] There are two problems in manually processing plate tensile specimens: First, in GB / T228 2021 "Tensile Test of Metal Materials", the original cross-sectional area is determined: when measuring the cross-sectional area of ​​the specimen, measurements are performed at least at three different positions in the parallel length area of ​​the specimen. Different people have different experiences and feels in manually polishing plate tensile specimens, resulting in the parallel section size tolerance and form and position tolerance of the processed plate tensile specimen test exceeding the tolerance, and the processed side surface is not perpendicular to the upper and lower surfaces, and some side surfaces are arc-shaped. The measured cross-sectional area has a large error from the actual cross-sectional area, which affects the experimental results; second, the transition arc and the parallel section should be tangent at the intersection. Due to the force control of manual polishing, transition polishing often occurs here, resulting in over-cutting or arc size deformation, asymmetry of the left and right arcs, etc., which causes the specimen to tilt and slip during the mounting test, affecting the experimental results. Summary of the Invention

[0006] The purpose of the present invention is to provide a device for grinding and polishing the side surface of a plate-shaped tensile specimen, so as to solve the problems that conventional manual grinding cannot ensure the uniform width of the parallel section of the specimen, the smooth transition of the arc section, and the surface roughness does not meet the standards, and realize automatic grinding of the side surface of the plate-shaped tensile specimen after clamping.

[0007] The technical solution of the present invention is:

[0008] A device for grinding and polishing the side surface of a plate-shaped tensile specimen, wherein a Y-axis guide rail and a Z-axis guide rail are assembled on a base, an X-axis guide rail is assembled on a Y-axis guide rail slider on the Y-axis guide rail, a specimen to be ground is set on the X-axis guide rail slider on the X-axis guide rail, and a spindle motor for mounting a grinding head is assembled on the Z-axis guide rail slider on the Z-axis guide rail, forming an XYZ three-axis motion system.

[0009] The device for grinding and polishing the side surface of a plate-shaped tensile specimen is characterized in that the X-axis guide rail and the Y-axis guide rail are stacked, the Y-axis guide rail slider is installed on the top of the Y-axis guide rail and is in sliding cooperation with the Y-axis guide rail, the X-axis guide rail is assembled on the Y-axis guide rail slider, the Y-axis guide rail servo motor is connected to the Y-axis guide rail slider, and drives the Y-axis guide rail slider to move horizontally along the Y-axis guide rail; the X-axis guide rail slider is installed on the top of the X-axis guide rail and is in sliding cooperation with the X-axis guide rail, a vise is installed on the top of the X-axis guide rail slider, the specimen to be ground is set on the vise, the X-axis servo motor is connected to the X-axis guide rail slider, and drives the X-axis guide rail slider to move horizontally along the X-axis guide rail; the Z-axis guide rail slider is installed on one side of the Z-axis guide rail and is in sliding cooperation with the Z-axis guide rail, the Z-axis guide servo motor is connected to the Z-axis guide rail slider, and drives the Z-axis guide rail slider to move vertically along the Z-axis guide rail.

[0010] The device for grinding and polishing the side surface of a plate-shaped tensile specimen is characterized in that the spindle motor frame is assembled on the Z-axis guide rail slider through an L-shaped adapter block B, the spindle motor is installed on the spindle motor frame, and the spindle motor and the spindle motor frame are locked by bolts after clamping, and the spindle motor is perpendicular to the YZ plane.

[0011] In the device for grinding and polishing the side surface of a plate-shaped tensile specimen, an L-shaped adapter block A is provided on the other side of the Z-axis guide rail, and the L-shaped adapter block A is respectively connected to the Z-axis guide rail and the base to further tighten the Z-axis guide rail.

[0012] The device for grinding and polishing the side surface of a plate-shaped tensile specimen has a Y-axis guide rail assembled on the base through a trapezoidal groove of the base, and a Z-axis guide rail is independently placed vertically and assembled on the base through a trapezoidal groove of the base. There is a certain distance between the Z-axis guide rail and the X-axis guide rail and the Y-axis guide rail.

[0013] In the device for grinding and polishing the side surface of a plate-shaped tensile specimen, the vise is perpendicular to the YZ plane, and the jaws of the vise are parallel to the X-axis guide rail.

[0014] In the device for grinding and polishing the side surface of a plate-shaped tensile specimen, a grinding head is installed on the rotating end spindle of the spindle motor, and the grinding head and the spindle motor are clamped by an ER chuck.

[0015] The device for grinding and polishing the side surface of a plate-shaped tensile specimen is equipped with limiters on the sides of the X-axis guide rail, the Y-axis guide rail, and the Z-axis guide rail. The limiters correspond to the corresponding guide rail sliders, so that the guide rail sliders reciprocate along the corresponding guide rails.

[0016] The device for grinding and polishing the side surface of a plate-shaped tensile specimen is equipped with an industrial control computer. The X-axis servo motor, Y-axis guide rail servo motor, and Z-axis guide rail servo motor are respectively connected to the industrial control computer. The X-axis servo motor, Y-axis guide rail servo motor, and Z-axis guide rail servo motor are respectively equipped with torque sensors.

[0017] The device for grinding and polishing the side surface of a plate-shaped tensile specimen has mechanical sensors installed directly below the vise and on the side of the jaws. The mechanical sensors are connected to the signal input end of an industrial control computer. The signals are transmitted to the industrial control computer in real time through the mechanical sensors, and the industrial control computer then adjusts the servo motor to achieve automatic grinding.

[0018] The design concept of the present invention is:

[0019] Compared with traditional manual grinding, which cannot control the dimensional accuracy of the side surface and cannot ensure that the side surface is perpendicular to the plane after manual grinding, the device of the present invention perfectly solves this difficulty. While being able to control the dimensional accuracy of the side surface, it can also perform all-round grinding on the arc of the side surface, perfectly removing the high-temperature oxide layer and cutting texture generated after the sample is cut by the electric spark wire cutting machine, making the experimental data more accurate. In addition, the device of the present invention has two sets of grinding control systems. When the parameters of the side surface contour line of the sample to be ground are unclear, the built-in mechanical sensor and servo motor feedback signal of the equipment can be relied on, and the industrial control computer can further perform real-time data analysis and processing, so that the grinding head can move along the outer contour of the plate-shaped tensile sample, thereby achieving an automatic contour grinding effect. When the contour line value of the side surface of the sample to be ground is known, after the contour line value is input into the industrial control computer, the spindle moves along this route, and automatic grinding can be achieved.

[0020] The advantages and beneficial effects of the present invention are:

[0021] 1. The present invention has a simple structure and is easy to operate. It solves the problem that the manual grinding of the side surface of the plate-shaped tensile specimen after electric spark wire cutting processing has insufficient dimensional accuracy and roughness that does not meet the test standards. It achieves the effect of automatic grinding and improves the experimental test accuracy of the plate-shaped mechanical tensile specimen.

[0022] 2. The present invention can realize automatic control of the grinding motion trajectory, so that after the plate-shaped tensile specimen is ground, the side surface of the parallel section has low roughness and uniform width, the arc section size conforms to the drawing, the transition is smooth, and the side surface roughness meets the test requirements.

[0023] 3. In the present invention, the Y-axis guide and the Z-axis guide are assembled on the base, the X-axis guide is assembled on the Y-axis guide slider on the Y-axis guide, the sample to be polished is set on the X-axis guide slider on the X-axis guide, the spindle motor for installing the polishing head is assembled on the Z-axis guide slider on the Z-axis guide, and the X-axis guide, Y-axis guide, and Z-axis guide are respectively equipped with corresponding servo motors, so that free movement of the XYZ three axes can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention.

[0025] In the figure, 1. Z-axis guide servo motor; 2. L-shaped adapter block A; 3. Industrial computer; 4. ER chuck; 5. Grinding head; 6. Vise; 7. X-axis guide slider; 8. Y-axis guide servo motor; 9. X-axis guide; 10. Y-axis guide slider; 11. Limiter; 12. Y-axis guide; 13. X-axis servo motor; 14. Base; 15. Specimen to be ground; 16. Z-axis guide; 17. Z-axis guide slider; 18. L-shaped adapter block B; 19. Spindle motor frame; 20. Spindle motor. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, the present invention proposes a device for automatic grinding of the side surface of a plate-shaped stretching machine, which mainly includes: guide rails (X-axis guide rail 9, Y-axis guide rail 12, Z-axis guide rail 16), servo motors (X-axis servo motor 13, Y-axis guide rail servo motor 8, Z-axis guide rail servo motor 1), spindle motor 20, vise 6, etc. The specific structure is as follows:

[0027] The X-axis guide rail 9 and the Y-axis guide rail 12 are stacked and placed. The Y-axis guide rail 12 is assembled to the base 14 through the trapezoidal groove of the base 14. The Y-axis guide rail slider 10 is mounted on the top of the Y-axis guide rail 12 and slides with the Y-axis guide rail 12. The X-axis guide rail 9 is assembled on the Y-axis guide rail slider 10. The Y-axis guide rail servo motor 8 is connected to the Y-axis guide rail slider 10 via a ball screw, driving the Y-axis guide rail slider 10 to move horizontally along the Y-axis guide rail 12. The Y-axis guide rail 12 has a supporting and guiding function. The X-axis guide rail slider 7 is mounted on the top of the X-axis guide rail 9 and slides with the X-axis guide rail 9. A vise 6 is installed on the top of the X-axis guide rail slider 7. The vise 6 is perpendicular to the YZ plane, and the jaws of the vise 6 are parallel to the X-axis guide rail 9. The sample 15 to be polished is set on the vise 6. The X-axis servo motor 13 is connected to the X-axis guide rail slider 7 via a ball screw, driving the X-axis guide rail slider 7 to move horizontally along the X-axis guide rail 9.

[0028] The Z-axis guide rail 16 is independently placed vertically and assembled to the base 14 through the trapezoidal groove of the base 14. The Z-axis guide rail 16 is at a certain distance from the X-axis guide rail 9 and the Y-axis guide rail 12. The Z-axis guide rail slider 17 is installed on one side of the Z-axis guide rail 16 and is in sliding cooperation with the Z-axis guide rail 16. The Z-axis guide rail servo motor 1 is connected to the Z-axis guide rail slider 17 through a ball screw, driving the Z-axis guide rail slider 17 to move vertically along the Z-axis guide rail 16. The spindle motor frame 19 is assembled to the Z-axis guide rail slider 17 through the L-shaped adapter block B18. The spindle motor 20 is installed on the spindle motor frame 19. The spindle motor 20 and the spindle motor frame 19 are locked with bolts after clamping to further ensure the operating stability of the spindle at the rotating end of the spindle motor 20. The spindle motor 20 is perpendicular to the YZ plane. An L-shaped adapter block A2 is provided on the other side of the Z-axis guide rail 16 . The L-shaped adapter block A2 is connected to the Z-axis guide rail 16 and the base 14 respectively, further tightening the Z-axis guide rail 16 to make the structure more stable.

[0029] The grinding head 5 is installed on the main shaft of the rotating end of the spindle motor 20. The grinding head 5 and the spindle motor 20 are clamped by the ER chuck 4 (the ER chuck is a spring chuck developed by the Swiss company Rego-Fix). When the servo motor is in a high-speed rotating motion state, its circular runout can be guaranteed to achieve high-precision matching. After the corresponding guide rail slider is installed on the guide rail, the surfaces of the guide rail and the guide rail slider can be tightly fitted to ensure accuracy. The sides of the X-axis guide rail 9, the Y-axis guide rail 12, and the Z-axis guide rail 16 are all equipped with limiters 11. The limiters 11 correspond to the corresponding guide rail sliders, so that the guide rail sliders can reciprocate along the corresponding guide rails and avoid overtravel of the equipment. The X-axis servo motor 13, the Y-axis guide rail servo motor 8, and the Z-axis guide rail servo motor 1 are respectively equipped with torque sensors. When the spindle motor 20 grinds the sample to be ground 15 through the grinding head 5, the feed amount can be controlled more accurately.

[0030] The device of the present invention is equipped with an industrial control computer 3 for intelligent control. The servo motors for the X-axis guide rail 9, Y-axis guide rail 12, and Z-axis guide rail 16 are each connected to the industrial control computer 3, enabling the device to operate with high precision and a large load capacity. Two sets of force sensors are installed directly below the vise 6 and to the sides of the jaws. The force sensors are connected to the signal input terminals of the industrial control computer 3. The force sensors transmit signals to the industrial control computer 3 in real time, which then adjusts the servo motors to achieve automatic grinding.

[0031] During operation, a specimen 15 (e.g., a plate-shaped tensile specimen) is clamped to a vise 6. The contour of the side surface of the specimen 15 is input via the industrial control computer 3, and the device automatically operates. The Y-axis guide rails 12 and Z-axis guide rails 16, driven by their corresponding servo motors, begin to move along their routes. Once the spindle motor 20 is running, the grinding head 5 automatically grinds the side surface of the specimen 15. During the grinding process, the X-axis servo motor 13 reciprocates to prevent the grinding head 5 from being in constant line contact with the side surface of the specimen 15, which could cause local damage to the grinding head 5 and reduce accuracy.

[0032] After clamping the specimen to be ground, if the contour parameters of the plate-like tensile specimen are unknown, the device's built-in mechanical sensors and servo motor feedback signals can be used to perform real-time data analysis and processing on the industrial control computer, allowing the grinding head to follow the outer contour of the plate-like tensile specimen, thereby achieving an automatic contour grinding effect. If the contour parameters of the plate-like tensile specimen are known, the parameters of the side contour of the workpiece to be ground can be input on the industrial control computer. The device's spindle will then operate along this path, and the grinding head will grind the side surface of the grinding specimen to achieve an automatic grinding effect. At this time, the built-in mechanical sensors also operate to assist in grinding.

Claims

1. A device for grinding and polishing the side surface of a plate-shaped tensile specimen, characterized in that: The Y-axis guide and the Z-axis guide are assembled on the base, the X-axis guide is assembled on the Y-axis guide slider on the Y-axis guide, the sample to be polished is set on the X-axis guide slider on the X-axis guide, and the spindle motor for installing the polishing head is assembled on the Z-axis guide slider on the Z-axis guide to form an XYZ three-axis motion system.

2. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 1, characterized in that: The X-axis guide rail and the Y-axis guide rail are stacked, the Y-axis guide rail slider is installed on the top of the Y-axis guide rail and is in sliding cooperation with the Y-axis guide rail, the X-axis guide rail is assembled on the Y-axis guide rail slider, the Y-axis guide rail servo motor is connected to the Y-axis guide rail slider, and drives the Y-axis guide rail slider to move horizontally along the Y-axis guide rail; the X-axis guide rail slider is installed on the top of the X-axis guide rail and is in sliding cooperation with the X-axis guide rail, a vise is installed on the top of the X-axis guide rail slider, the sample to be polished is set on the vise, the X-axis servo motor is connected to the X-axis guide rail slider, and drives the X-axis guide rail slider to move horizontally along the X-axis guide rail; the Z-axis guide rail slider is installed on one side of the Z-axis guide rail and is in sliding cooperation with the Z-axis guide rail, the Z-axis guide servo motor is connected to the Z-axis guide rail slider, and drives the Z-axis guide rail slider to move vertically along the Z-axis guide rail.

3. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: The spindle motor frame is assembled on the Z-axis guide rail slider through the L-shaped adapter block B, and the spindle motor is installed on the spindle motor frame. The spindle motor and the spindle motor frame are locked by bolts after clamping, and the spindle motor is perpendicular to the YZ plane.

4. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: An L-shaped adapter block A is arranged on the other side of the Z-axis guide rail, and the L-shaped adapter block A is respectively connected to the Z-axis guide rail and the base to further tighten the Z-axis guide rail.

5. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: The Y-axis guide rail is assembled to the base through the trapezoidal groove of the base, and the Z-axis guide rail is independently placed vertically and assembled to the base through the trapezoidal groove of the base. There is a certain distance between the Z-axis guide rail and the X-axis guide rail and the Y-axis guide rail.

6. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: The vise is perpendicular to the YZ plane, and the jaws of the vise are parallel to the X-axis guide rail.

7. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: A grinding head is installed on the rotating end of the spindle motor, and the grinding head and the spindle motor are clamped by an ER chuck.

8. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: The sides of the X-axis guide rail, the Y-axis guide rail, and the Z-axis guide rail are all equipped with limiters, which correspond to the corresponding guide rail sliders, so that the guide rail sliders can reciprocate along the corresponding guide rails.

9. The device for grinding and polishing the side surface of a plate-shaped tensile specimen according to claim 2, characterized in that: The device is equipped with an industrial control computer, and the X-axis servo motor, the Y-axis guide servo motor, and the Z-axis guide servo motor are respectively connected to the industrial control computer, and the X-axis servo motor, the Y-axis guide servo motor, and the Z-axis guide servo motor are respectively equipped with torque sensors.

10. The device for grinding and polishing the side surface of a plate-shaped tensile test specimen according to claim 9, characterized in that: Mechanical sensors are installed directly below the vise and on the side of the jaws. The mechanical sensors are connected to the signal input terminal of the industrial control computer. The signals are transmitted to the industrial control computer in real time through the mechanical sensors. The industrial control computer then adjusts the servo motor to realize automatic grinding.

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