A flexible sample clamping device and method for measuring Vickers hardness

Abstract

The present invention relates to the technical field of Vickers hardness measurement clamping devices, and in particular to a flexible sample clamping device and method for measuring Vickers hardness. By providing a bottom flexible clamp and a lateral flexible clamp, the portion of each clamp in contact with the sample can be flexibly deformed and thus can adapt to the contour of the sample. The present invention provides a clamping device in each flexible clamp, which can tighten the internal movable components of each flexible clamp after adapting to the sample shape, thereby making each flexible clamp itself a rigid whole that can adapt to the sample shape and provide rigid support for the positioning of the sample. By providing a self-locking stud bolt and a slider, the lateral clamp after being transformed into a rigid component can move inward under the drive of the slider to achieve clamping of the sample, so that the sample is clamped and fixed on the device, and finally the Vickers hardness measurement of the special-shaped sample can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of Vickers hardness measurement clamping devices, and in particular to a flexible sample clamping device and method for measuring Vickers hardness. Background Art

[0002] Hardness is a mechanical property that measures the degree of hardness or softness of a material. It is defined as the material's resistance to surface indentation (or notching) under given load conditions. Among static hardness determination methods, the Vickers hardness test is the most accurate. This method covers a wide hardness range and can measure the hardness of the vast majority of currently used metal materials.

[0003] During the Vickers hardness measurement process, the specimen should be firmly placed on a rigid support table to ensure that the specimen does not move during the hardness measurement. Therefore, a corresponding clamping device is required to obtain an accurate Vickers hardness value under the same load conditions. For specimens with relatively regular shapes, conventional clamping devices can ensure stable test results. However, for irregularly shaped specimens, appropriate cutting, replacement of the corresponding clamping device, or inlaying of the specimen are usually required to ensure accurate test results, which is relatively cumbersome. Therefore, a flexible specimen clamping device for measuring Vickers hardness is urgently needed to achieve stable clamping of irregularly shaped specimens.

[0004] CN202020848893.6 discloses "a clamping device for a microhardness tester", including a clamping body, a first clamping platform and a second clamping platform. Positioning holes are provided on the top surface of the clamping body. The first clamping platform is fixed to the middle of the top of the clamping body. There are two second clamping platforms in total. The second clamping platforms are respectively fixed on both sides of the top of the clamping body. The second clamping platforms are respectively installed on the outside of both sides of the first clamping platform. The first clamping platform includes a screw lifting platform. A rotating nut is provided on the outer side of the screw lifting platform. A limiting block is provided inside the bottom end of the rotating nut. The outer surface of the limiting block is provided with serrations. Sheet-shaped pressure plates are provided at both ends of the top of the rotating nut.

[0005] CN201120169008.2 discloses "a Vickers microhardness tester sample clamping device", which includes a screw with a rotating handle arranged on the base, symmetrical clamping blocks respectively cooperate with the screw through their respective horizontal screw holes, and the screw drives the symmetrical clamping blocks to move toward each other, and symmetrical dovetail grooves are respectively provided on the upper part of the inner side surfaces of the symmetrical clamping blocks, and a replaceable clamping head device is installed through the dovetail grooves. The structure of the replaceable clamping head device is a clamping head bracket composed of a dovetail-shaped slider, and a pillar perpendicular to the outer side surface of the clamping head bracket is fixed to its outer side surface, and a special clamping head is provided at the outer end of the pillar, and the clamping head bracket is movably engaged with the dovetail groove.

[0006] CN202023278916.3 discloses "a specimen clamping device for metal Vickers hardness testing", including a base, a fastening block and a sliding block that are sequentially clamped in the groove cavity of the base; a rectangular groove is processed in the middle part of the base, and along the length direction of the groove, two left and right guide grooves symmetrically distributed with the base axis are formed in the groove through left and right bosses arranged near both sides of the groove, and the groove walls at the front and rear ends of the groove are processed with left and right through holes for passing through the screw-type rotating shaft, and the left and right through holes located on the groove wall at one end are internal threaded holes; the fastening block and the sliding block are both rectangular blocks with an inverted concave structure in cross section, and left and right through holes for passing through the screw-type rotating shaft are processed on the fastening block and the sliding block body, and the left and right through holes located on the fastening block are internal threaded holes; the fastening block and the sliding block are sequentially clamped in the rectangular groove of the base, and are respectively matched with the left and right guide grooves of the base through guide flanges extending vertically downward at the left and right ends of the bottom.

[0007] The above-mentioned clamping device has the following disadvantages: poor clamping effect for special-shaped specimens and poor stability during the test, which in turn affects the final test results. Summary of the Invention

[0008] In order to overcome the shortcomings of the existing technology, a flexible sample clamping device and method for measuring Vickers hardness are provided, which has good clamping effect on special-shaped samples, strong stability during the test process, and ensures the final test results.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A flexible sample clamping device for measuring Vickers hardness includes a base plate, a bottom clamp, a lateral clamp, a first slider, and a second slider; the bottom clamp is fixed to the base plate, and two lateral clamps are respectively fixed to the first slider and the second slider, the first slider and the second slider are slidably connected to the base plate, and the bottom clamp is located between the first slider and the second slider; the bottom clamp is provided with an elastic support component for flexibly supporting the sample, and the two lateral clamps are provided with elastic clamping components for flexibly clamping the sample.

[0011] As a further improvement of the present invention, the lateral clamp includes an upper shell, a lower shell, a sliding column and a sliding pin; the upper shell and the lower shell have the same structure and are symmetrically arranged, the sliding column and the sliding pin are installed between the upper and lower shells, a spring is provided on the sliding column, and the sliding column is slidingly connected to the upper and lower shells; the sliding pin is slidingly connected to the upper and lower shells, one end of the sliding pin rests on the sliding column, and the other end extends out of the upper and lower shells.

[0012] As a further improvement of the present invention, the lower shell is provided with a first slide groove, a second slide groove and a third slide groove, the first slide groove is located on one side of the lower shell, the third slide groove is located on the other side of the lower shell, and the third slide groove is connected to the second slide groove; a first groove is provided on one side of the second slide groove that crosses the third slide groove, the second slide groove is provided with an installation groove, and a second groove is provided perpendicular to the installation groove; the internal structure of the upper shell is completely symmetrical with the lower shell.

[0013] As a further improvement of the present invention, the cross section of the first chute corresponds to the sliding column, and one end of the sliding column is slidingly connected to the first chute; the cross section of the third chute corresponds to the sliding pin, and the sliding pin is slidingly connected to the third chute.

[0014] As a further improvement of the present invention, a limiting rod is provided inside the first groove, and two symmetrically distributed limiting grooves are provided on one side of the sliding pin. The limiting rod is slidably connected in the limiting groove, and the other end of the sliding column is pressed against one end of the sliding pin under the action of the spring.

[0015] As a further improvement of the present invention, a pressure block is slidably connected in the second sliding groove, and the side of the pressure block close to the sliding pin is an arc-shaped concave surface. A square nut is inserted in the installation groove, and a second fastening bolt is threadedly connected to the middle of the nut, and the second fastening bolt is passed through the second groove.

[0016] As a further improvement of the present invention, the internal structure of the bottom clamp is the same as that of the lateral clamp, and a first fastening bolt is provided on the side of the bottom clamp.

[0017] As a further improvement of the present invention, the base plate is provided with a fixed block, which is threadedly connected to a double-headed screw; the threads on both sides of the double-headed screw are threaded in opposite directions. The two sides of the double-headed screw are respectively threadedly connected to the first slider and the second slider to form a transmission fit, and a handle is fixed to one end of the double-headed screw.

[0018] A method for measuring Vickers hardness comprises the following steps:

[0019] Step 1) According to the provisions of standard GB / T4340, the part of the special-shaped specimen to be tested is first polished to obtain a flat, smooth, and dirt-free test surface;

[0020] Step 2) Place the specimen on top of the bottom fixture's sliding pins, with the test surface facing upward. Press a smooth, flat metal plate against the specimen's test surface, aligning the test surface with the smooth bottom surface of the metal plate. Press the plate downward until the bottom surfaces of both ends of the plate align with the top surface of the upper shell of the side fixture, causing some of the sliding pins on the bottom fixture to move downward. The internal spring and slide rod force the top of the sliding pins to press tightly against the specimen's bottom surface. The distance that the sliding pins can move will vary depending on the specimen's shape.

[0021] Step 3) The handle is then rotated to rotate the double-headed screw, and the first and second sliders drive the lateral clamps toward the center, causing the sliding pin to overcome the elastic force of the spring after contacting the edge of the specimen and slide into the third sliding groove. This allows the front end of the sliding pin to tightly contact the two sides of the specimen as the specimen shape changes. The first and second fastening bolts are then tightened to fix the position of the sliding pin in a state that adapts to the specimen shape, thereby forming a rigid connection with the clamp.

[0022] Step 4) Continue to rotate the handle so that the two side clamps are clamped towards the middle, finally fixing the sample. Remove the upper metal plate and place the device on the Vickers hardness measurement platform to start the Vickers hardness measurement:

[0023] Step 5) After the test is completed, the sample can be removed by rotating the handle in the opposite direction, and the first and second fastening bolts can be loosened to restore the flexibility of each clamp for the next use.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention provides a bottom flexible clamp and a lateral flexible clamp so that the portion of each clamp in contact with the sample can be flexibly deformed and thus can adapt to the contour of the sample.

[0026] 2. The present invention provides a clamping device in each flexible clamp, which enables each flexible clamp to tighten its internal movable components after adapting to the shape of the sample, thereby making each flexible clamp itself a rigid whole that can adapt to the shape of the sample and provide rigid support for the positioning of the sample.

[0027] 3. The present invention provides a self-locking stud bolt and a slider, so that the lateral clamp, after being transformed into a rigid component, can move inward under the drive of the slider to clamp the sample, so that the sample is clamped and fixed on the device, and finally the Vickers hardness measurement of the special-shaped sample can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the three-dimensional explosion structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the three-dimensional explosion structure of the lateral clamp of the present invention;

[0031] Figure 4 This is a schematic diagram of the lower shell structure of the lateral clamp of the present invention;

[0032] Figure 5 This is a schematic diagram of the three-dimensional structure of the sliding pin of the present invention;

[0033] Figure 6 It is a schematic diagram of the three-dimensional structure of the sliding column of the present invention.

[0034] In the figure: 1-base plate, 2-first slider, 3-bottom clamp, 4-first fastening bolt, 5-second slider, 6-stud screw, 7-upper shell, 8-sliding pin, 9-fixing block, 10-handle, 11-second fastening bolt, 12-square nut, 13-pressing block, 14-limiting rod, 15-sliding column, 16-lower shell, 17-first slide groove, 18-mounting groove, 19-second slide groove, 20-first groove, 21-third slide groove, 22-second groove, 23-limiting groove, 24-spring. DETAILED DESCRIPTION

[0035] The present invention discloses a flexible specimen clamping device and method for measuring Vickers hardness. Those skilled in the art may refer to the contents of this document and appropriately improve the process parameters to achieve the desired results. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0036] like Figures 1 to 6 As shown, a flexible specimen clamping device for measuring Vickers hardness comprises a base plate 1, a bottom clamp 3 capable of flexible support is provided above the middle of the base plate 1, a first slider 2 and a second slider 5 are slidably connected to the left and right sides of the base plate 1, and a lateral clamp capable of flexible clamping is fixed to the top of each of the first slider 2 and the second slider 5. The bottom clamp 3 is located between the two lateral clamps.

[0037] The lateral clamp includes an upper shell 7 and a lower shell 16. A plurality of sliding posts 15 and a plurality of sliding pins 8 are slidably connected on the left and right sides of the upper shell 7 and the lower shell 16 respectively. A spring 24 is sleeved on the sliding post 15, and the spring 24 is elastically connected between the sliding post 15 and the upper shell 7 and the lower shell 16.

[0038] In order to enable the lateral clamp to automatically adapt to the side contour of the special-shaped specimen, a first slide groove 17 is integrally formed on the left side of the top of the lower shell 16. Its cross-sectional shape is a semicircular shape corresponding to the slide post 15. The slide post 15 is slidably connected to the first slide groove 17. The slide post 15 is stepped, and its head diameter is smaller than the diameter of the sliding pin 8, and the rod diameter is smaller than its head diameter. The spring 24 is sleeved on the rod of the slide post 15, and the rod of the slide post 15 is slidably connected to the first slide groove 17. The spring 24 is elastically connected between the head of the slide post 15 and the right end face of the first slide groove 17.

[0039] A third slide groove 21 is integrally formed on the top right side of the lower shell 16, and its cross-section is a bar. The sliding pin 8 is slidably connected to the third slide groove 21. The number of sliding pins 8 is the same as the number of sliding columns 15. The right end of the sliding column 15 is pressed against the left end of the sliding pin 8 under the action of the spring 24. The internal structure of the upper shell 7 is exactly the same as that of the lower shell 16, and is symmetrical up and down.

[0040] By providing the sliding pin 8, the sliding column 15 and the spring 24, the sliding pin 8 can overcome the elastic force of the spring 24 under the action of an external force and slide into the third sliding groove 21. As a result, the end of each sliding pin 8 can be pressed against different positions on the side of the specimen under the action of the spring 24, so that the lateral clamp automatically adapts to the side contour of the specimen.

[0041] To ensure the position of the slide pin 8 after adjusting to the specimen's shape, a second slide slot 19 is integrally formed on the lower right side of the third slide slot 21. A pressure block 13 is slidably connected within the second slide slot 19. A mounting slot 18 is integrally formed below the second slide slot 19, and a second groove 22 is integrally formed perpendicular to the mounting slot 18. A square nut 12 is inserted into the mounting slot 18, and a second fastening bolt 11 is threadedly connected to the center of the mounting slot 18. The second fastening bolt 11 is inserted into the second groove 22.

[0042] By providing a square nut 12 inserted into the mounting groove 18, a second fastening bolt 11 threadedly connected to the square nut 12 and a pressure block 13 slidably connected to the second slide groove 19, the pressure block 13 can be pushed toward the third slide groove 21 by the head of the second fastening bolt 11 moving inward, thereby pressing the sliding pin 8 in the third slide groove 21. Under the action of friction, the position of each sliding pin 8 is fixed, thereby realizing that each sliding pin 8 forms a rigid whole with the upper shell 7 and the lower shell 16.

[0043] In order to prevent the sliding pin 8 from escaping from the third sliding groove 21 when it is not tightened and fixed, a first groove 20 is integrally formed on the left side of the second sliding groove 19, and a limiting rod 14 is arranged inside the first groove 20; two symmetrically distributed limiting grooves 23 are integrally formed on the left side of the sliding pin 8, and the limiting rod 14 is slidably connected to the limiting groove 23, so that the sliding range of the sliding pin 8 is limited to a range equal to the length of the limiting groove 23, thereby preventing the sliding pin 8 from escaping from the third sliding groove 21 when it is not tightened.

[0044] In order to achieve flexible support for the bottom of the special-shaped specimen and enable the flexible support at the bottom to become rigid support after adjusting the position of the specimen, the internal structure of the bottom clamp 3 is similar to that of the lateral clamp, and its working principle is the same as that of the lateral clamp. The side of the bottom clamp 3 is rotatably connected with a first fastening bolt 4.

[0045] In order to allow the lateral clamps on both sides to move toward the center after adapting to the specimen's shape and being tightened into rigid parts, thereby achieving clamping and fixing the specimen, a fixing block 9 is fixed in the middle of the base plate 1. A double-headed screw 6 is rotatably connected to the fixing block 9. The double-headed screw 6 is symmetrical about the middle rotating portion, and the threads on both sides rotate in opposite directions. The middle portion is rotatably connected to the fixing block. Limiting rings are integrally formed on both sides of the middle portion of the double-headed screw 6. The outer diameter of the limiting ring is larger than the diameter of the middle rotating portion of the double-headed screw, which can fix the axial position between the double-headed screw 6 and the fixing block 9 without affecting their relative rotation. The double-headed screw 6 forms a transmission connection with the first slider 2 and the second slider 5 through threads. A handle 10 is fixed to the right end. The screw pair between the double-headed screw 6 and the first slider 2 and the second slider 5 can self-lock in the reverse stroke.

[0046] In order to facilitate the positioning of the sample during installation, the bottom plate 1 of the device is parallel to the top surface of the upper shell 7 of the lateral clamp after assembly.

[0047] A method for measuring Vickers hardness comprises the following steps:

[0048] 1. According to the method specified in the standard GB / T4340, when using this embodiment, the part of the special-shaped specimen to be tested is first ground and polished to obtain a flat, smooth, and dirt-free test surface.

[0049] 2. Place the specimen on the top of the sliding pin 8 of the bottom fixture 3 with the test surface facing upward. Press a flat and smooth metal plate on the test surface of the specimen so that the test surface and the smooth bottom surface of the metal plate coincide with each other. Press the metal plate downward so that the bottom surfaces at both ends of the metal plate are close to the top surface of the upper shell 7 of the lateral fixture. This causes part of the sliding pin 8 on the bottom fixture 3 to move downward. Under the action of the internal spring 24 and the slide rod 15, the top of the sliding pin 8 is tightly pressed against the bottom plane of the specimen. The distance that the sliding pin 8 can move in different positions will vary depending on the shape of the specimen.

[0050] 3. Then, the handle 10 is rotated to rotate the double-headed screw 6. The first slider 2 and the second slider 5 drive the lateral clamp to move toward the middle, so that the sliding pin 8 overcomes the elastic force of the spring 24 after supporting the edge of the specimen and slides into the third sliding groove 21. As a result, the front end of the sliding pin 8 can tightly press against both sides of the specimen as the shape of the specimen changes. Then, the first fastening bolt 4 and the second fastening bolt 11 are tightened, so that the position of the sliding pin 8 is fixed in a state that adapts to the shape of the specimen, thereby forming a rigid connection with the clamp.

[0051] 4. Continue to rotate the handle 10 so that the two sides of the clamp are clamped towards the middle, and finally the sample is fixed. Remove the upper metal plate and place the device on the Vickers hardness measurement platform to start the Vickers hardness measurement.

[0052] 5. After the test is completed, simply rotate the handle 10 in the opposite direction to remove the sample, and loosen the first fastening bolt 4 and the second fastening bolt 11 to restore the flexible state of each clamp for the next use.

[0053] The present invention provides a bottom flexible clamp and a lateral flexible clamp so that the portion of each clamp in contact with the sample can be flexibly deformed and thus can adapt to the contour of the sample. The present invention provides a clamping device in each flexible clamp so that each flexible clamp can tighten its internal movable components after adapting to the sample shape, thereby making each flexible clamp itself a rigid entity that can adapt to the sample shape and provide rigid support for the positioning of the sample. The present invention provides a self-locking stud bolt 6 and a slider so that the lateral clamp, after being transformed into a rigid component, can move inward under the drive of the slider to achieve clamping of the sample, thereby clamping the sample and fixing it on the device, and finally achieving Vickers hardness measurement of special-shaped samples.

[0054] The present invention realizes stable clamping of special-shaped specimens, thereby ensuring the final test results.

[0055] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A flexible sample clamping device for measuring Vickers hardness, characterized in that: The apparatus comprises a bottom plate, a bottom clamp, a lateral clamp, a first slider, and a second slider; the bottom clamp is fixed to the bottom plate, the two lateral clamps are fixed to the first slider and the second slider respectively, the first slider and the second slider are slidably connected to the bottom plate, and the bottom clamp is located between the first slider and the second slider; the bottom clamp is provided with an elastic support component to flexibly support the sample, and the two lateral clamps are provided with elastic clamping components to flexibly clamp the sample; The lateral clamp includes an upper shell, a lower shell, a sliding post and a sliding pin; the upper shell and the lower shell have the same structure and are symmetrically arranged, the sliding post and the sliding pin are installed between the upper and lower shells, a spring is sleeved on the sliding post, and the sliding post is slidably connected to the upper and lower shells; the sliding pin is slidably connected to the upper and lower shells, one end of the sliding pin abuts against the sliding post, and the other end extends out of the upper and lower shells; The lower shell is provided with a first slide groove, a second slide groove and a third slide groove. The first slide groove is located on one side of the lower shell, and the third slide groove is located on the other side of the lower shell. The third slide groove is connected to the second slide groove. A first groove is provided on one side of the second slide groove and crosses the third slide groove. The second slide groove is provided with a mounting groove, and a second groove is provided perpendicular to the mounting groove. The internal structure of the upper shell is completely symmetrical with the lower shell. The cross section of the first chute corresponds to that of the sliding post, and one end of the sliding post is slidably connected to the first chute; the cross section of the third chute corresponds to that of the sliding pin, and the sliding pin is slidably connected to the third chute; A pressure block is slidably connected in the second sliding groove, and the side of the pressure block close to the sliding pin is an arc-shaped concave surface. A square nut is inserted in the installation groove, and a second fastening bolt is threadedly connected to the middle of the nut. The second fastening bolt is inserted into the second groove.

2. A flexible sample clamping device for measuring Vickers hardness according to claim 1, characterized in that: A limiting rod is provided inside the first groove, and two symmetrically distributed limiting grooves are provided on one side of the sliding pin. The limiting rod is slidably connected in the limiting groove, and the other end of the sliding column is pressed against one end of the sliding pin under the action of the spring.

3. The flexible sample clamping device for measuring Vickers hardness according to claim 1, characterized in that: The internal structure of the bottom clamp is the same as that of the lateral clamp, and a first fastening bolt is provided on the side of the bottom clamp.

4. The flexible sample clamping device for measuring Vickers hardness according to claim 1, characterized in that: The bottom plate is provided with a fixed block, which is threadedly connected to the double-headed screw; the threads on both sides of the double-headed screw rotate in opposite directions; the two sides of the double-headed screw are respectively threadedly connected to the first slider and the second slider to form a transmission fit, and a rotating handle is fixed to one end of the double-headed screw.

5. A method for measuring Vickers hardness using a flexible sample clamping device according to any one of claims 1 to 4, characterized in that: The specific steps include: Step 1) According to the provisions of GB / T4340, the part of the special-shaped specimen to be tested is first polished to obtain a flat, smooth, and dirt-free test surface; Step 2) Place the specimen on top of the bottom fixture's sliding pins, with the test surface facing upward. Press a smooth, flat metal plate against the specimen's test surface, aligning the test surface with the smooth bottom of the metal plate. Press the plate downward until the bottom surfaces of both ends of the plate align with the top surface of the upper shell of the side fixture. This causes some of the sliding pins on the bottom fixture to move downward, and the internal spring and slide rod force the top of the sliding pins to press tightly against the specimen's bottom surface. The distance that the sliding pins can move will vary depending on the specimen's shape. Step 3) The handle is then rotated to rotate the double-headed screw, causing the first and second sliders to move the lateral clamp toward the center. This causes the sliding pin to press against the edge of the specimen, overcoming the elastic force of the spring and sliding into the third sliding groove. This allows the front end of the sliding pin to tightly press against both sides of the specimen as the specimen shape changes. The first and second fastening bolts are then tightened to secure the sliding pin in a position that conforms to the specimen shape, thereby forming a rigid connection with the clamp. Step 4) Continue to rotate the handle to tighten the two side clamps toward the center, finally securing the specimen. Remove the upper metal plate and place the device on the Vickers hardness measurement platform to begin the Vickers hardness measurement: Step 5) After the test is completed, rotate the handle in the opposite direction to remove the specimen. Loosen the first and second fastening bolts to restore the clamps to a flexible state for the next use.

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