An indenter
By using a novel displacement measurement structure in the indenter, the grating connecting rod is rigidly connected to the indenter assembly, and the actual displacement of the indenter on the object under test is directly measured. This solves the measurement error problem caused by elastic deformation under high load in macroscopic indentation testers, and achieves higher precision in indentation depth and mechanical performance parameters.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU JIELI INSTRUMENT CO LTD
- Filing Date
- 2025-06-19
- Publication Date
- 2026-07-31
AI Technical Summary
Existing macro indentation testers cannot effectively eliminate measurement errors caused by elastic deformation of the machine system under high loads, affecting the accuracy of indentation depth and mechanical property parameters.
An indenter is used, which uses a synchronous translation design of the first and second movable units, combined with a rigid connection between the grating link and the indenter assembly, to directly measure the actual displacement of the indenter on the object to be measured, avoiding the elastic deformation path of the pressure sensor, and using a grating ruler to obtain the indentation depth.
It significantly reduces the impact of system flexibility on measurement results, improves the accuracy and reliability of indentation depth and mechanical property parameters, and significantly enhances accuracy, especially in the testing of high-load and high-hardness materials.
Smart Images
Figure CN224581316U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of indentation instrument technology, and in particular relates to an indentation instrument. Background Technology
[0002] In the fields of materials engineering and quality control, macroscopic indentation testing (such as tensile strength and yield strength tests, or tests used to evaluate material plasticity and elastic modulus) is a core method for obtaining large-scale material mechanical properties. This type of testing typically applies high loads (tens to thousands of Newtons) by pressing an indenter into the material surface, and requires precise measurement of the indentation depth or residual indentation size to calculate performance parameters. The accuracy of indentation depth / size measurement directly determines the reliability of key indicators such as tensile strength, yield strength, and elastic modulus.
[0003] However, existing macroindentation testing instruments face a significant challenge: the elastic deformation of the machine system under high loads. During loading, the enormous force not only deforms the sample but also inevitably leads to considerable elastic deformation (system flexibility) in key load-bearing components such as the frame, loading shaft, and worktable of the testing instrument itself. This deformation is superimposed on the total displacement measured by the sensor, causing the recorded indenter displacement (apparent displacement) to be significantly greater than the actual displacement at the indenter-material contact point. For applications involving high-hardness materials or requiring precise depth measurements (such as calculating elastic recovery), this error severely distorts the load-displacement curve, thereby significantly reducing the accuracy of results such as hardness and modulus.
[0004] Traditional solutions primarily rely on empirical formulas or calibrations for correction after the fact. These methods not only increase operational complexity, but their accuracy is also limited by calibration conditions, material properties, and model assumptions, failing to eliminate system deformation interference at the source of measurement.
[0005] Therefore, there is an urgent need for an innovative structure that can directly avoid or significantly reduce the influence of machine elastic deformation during the measurement process. Utility Model Content
[0006] In order to overcome the shortcomings of the prior art, this utility model provides an indenter that eliminates the error introduced by the elastic deformation of the pressure sensor and can directly measure the actual displacement of the indenter assembly on the object to be measured.
[0007] The technical solution adopted by this utility model to solve its technical problem is: an indentation instrument, comprising:
[0008] Drive unit;
[0009] The first active unit includes at least a pressure head assembly and at least a measuring element that is rigidly connected to the pressure head assembly.
[0010] The second active unit includes at least a pressure sensor. The structure of the second active unit is fixedly connected to the pressure head assembly through the pressure sensor, and the structure of the second active unit is movably connected to the measuring element.
[0011] Before the pressure head assembly contacts the object to be measured, the drive unit drives the first movable unit and the second movable unit to translate synchronously;
[0012] After the indenter assembly contacts the object to be measured, the first movable unit and the second movable unit generate relative displacement under the drive of the drive unit, and the measuring element is used to obtain the indentation depth of the indenter assembly relative to the object to be measured.
[0013] Furthermore, the second active unit includes at least an active arm connected to the drive unit, a guide rail disposed on the active arm, and a sliding member movably connected to the guide rail. The active arm is connected to a pressure sensor, and the sliding member is connected to a measuring element.
[0014] Before the pressure head assembly contacts the object to be measured, the drive unit drives the movable arm to translate, and the first movable unit and the second movable unit translate synchronously.
[0015] After the pressure head assembly contacts the object to be measured, the drive unit drives the movable arm to continue to translate, and the measuring component translates along the guide rail with the sliding component, and the first movable unit and the second movable unit generate relative displacement.
[0016] Furthermore, the measuring component includes a grating link, a grating ruler disposed on the grating link, a grating link fixing ring connected to the pressure head assembly, and a grating reading head.
[0017] Furthermore, the drive unit includes a motor, a lead screw connected to the motor output shaft, and an adapter connected to the lead screw, which is connected to the movable arm.
[0018] Furthermore, the pressure sensor, movable arm, lead screw, and pressure head assembly are arranged concentrically and coaxially.
[0019] Furthermore, the guide rail extends vertically to the outer side of the movable arm. This invention proposes a novel displacement measurement structure for a macroscopic indentation tester. Through a unique design and sensor arrangement, this structure brings the displacement measurement reference as close as possible to the indenter-sample contact area, or effectively isolates the deformation path of the main load-bearing frame, thereby directly acquiring a displacement signal closer to the true contact depth. This significantly reduces the inherent influence of system flexibility on the final result, achieving higher accuracy indentation depth data and more reliable mechanical property parameters without complex post-processing corrections, especially improving accuracy in testing high-load, high-hardness materials.
[0020] The beneficial effects of this utility model are as follows: By utilizing the partial fixed assembly and partial movable assembly of the first and second movable units, the synchronous movement of the grating connecting rod and the indenter is achieved. Furthermore, the grating connecting rod with the grating ruler is directly and rigidly connected to the indenter assembly, which allows the measuring point of the grating ruler to avoid the elastic deformation path of the pressure sensor. The displacement of the grating connecting rod is not affected by the elastic deformation of the pressure sensor, thus eliminating the error introduced by the elastic deformation of the pressure sensor. The true displacement of the indenter on the object to be measured can be directly measured, that is, the indentation depth can be directly obtained. This fundamentally eliminates the interference of the elastic deformation of the pressure sensor itself on the depth measurement results, and significantly improves the accuracy and reliability of the indentation depth and the mechanical property parameters (such as tensile yield strength and elastic modulus) calculated therefrom. Attached Figure Description
[0021] Figure 1 The three-dimensional indentation instrument provided by this utility model Figure 1 .
[0022] Figure 2 The three-dimensional indentation instrument provided by this utility model Figure 2 .
[0023] Figure 3 The partial three-dimensional structure of the indentation instrument provided by this utility model Figure 1 .
[0024] Figure 4 The partial three-dimensional structure of the indentation instrument provided by this utility model Figure 2 .
[0025] Figure 5 The partial three-dimensional structure of the indentation instrument provided by this utility model Figure 3 .
[0026] Figure 6 This is a cross-sectional view of the indentation instrument provided by this utility model.
[0027] Figure 7 Schematic diagram of the exploded structure of the indenter provided by this utility model Figure 1 .
[0028] Figure 8 Schematic diagram of the exploded structure of the indenter provided by this utility model Figure 2 .
[0029] Among them, 1-first active unit, 11-pressure head assembly, 111-pressure head, 112-pressure head connector, 12-measuring component, 121-grating connecting rod, 123-grating connecting rod fixing ring, 124-grating reading head, 2-second active unit, 21-active arm, 22-guide rail, 23-sliding component, 3-drive unit, 31-motor, 32-lead screw, 33-adapter, 34-coupling, 35-bearing, 36-motor bearing seat, 4-pressure sensor, 41-pressure sensor adapter, 51-inner frame, 52-outer shell. Detailed Implementation
[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.
[0031] like Figure 1 , Figure 2 As shown, an indenter includes a drive unit 3, a first movable unit 1, a second movable unit 2, an inner frame 51, and a housing 52. The first movable unit 1 includes at least an indenter assembly 11 and a measuring element 12, at least a portion of the measuring element 12 being rigidly connected to the indenter assembly 11. The second movable unit 2 includes at least a pressure sensor 4, and a portion of the second movable unit 2 is fixedly connected to the indenter assembly 11 via the pressure sensor 4, while a portion of its structure is movably connected to the measuring element 12. In other words, the first movable unit 1 and the second movable unit 2 are movably connected via the measuring element 12. The aforementioned portion of the structure of the first movable unit 1 and all of the structure of the second movable unit 2 are located inside the housing 52.
[0032] Before the pressure head assembly 11 contacts the object to be measured, the drive unit 3 drives the first movable unit 1 and the second movable unit 2 to move synchronously. After the pressure head assembly 11 contacts the object to be measured, under the drive of the drive unit 3 and simultaneously under the pressure of the object to be measured, the first movable unit 1 and the second movable unit 2 generate relative displacement. The measuring element 12 is used to obtain the indentation depth of the pressure head assembly 12 relative to the object to be measured.
[0033] Specifically, such as Figures 3-8As shown, the second active unit 2 includes at least an active arm 21 connected to the drive unit 3, a guide rail 22 disposed on the active arm 21, and a slider 23 movably connected to the guide rail 22. The guide rail 22 extends vertically and is disposed on the outer side of the active arm 21. Specifically, a mounting groove adapted to the guide rail 22 is carved into the outer side of the active arm 21, so that when the measuring component 12 is movably assembled on the guide rail 22 via the slider 23, the outer wall of the measuring component 12 can slide against the outer side of the active arm 21, and its mating structure is more stable. The active arm 21 is connected to the pressure sensor 4. Specifically, the active arm 21 and the pressure sensor 4 are fixedly assembled. The slider 23 is connected to the measuring component 12, so that the measuring component 12 can slide up and down along the guide rail 22 with the slider 23.
[0034] Before the pressure head assembly 11 contacts the object to be measured, the drive unit 3 drives the movable arm 21 to translate, and the first movable unit 1 and the second movable unit 2 translate synchronously. After the pressure head assembly 11 contacts the object to be measured, the drive unit 3 drives the movable arm 21 to continue translating. The pressure head assembly 11 is blocked by the object to be measured, and thus, under the action of the pressure head assembly 11 and the drive arm 21, the pressure head assembly 11 and the pressure sensor 4 deform. The movable arm 21 continues to move downward, but the lower end of the measuring element 12 is fixedly assembled with the pressure head assembly 11 and cannot move downward further. At this time, the upper end of the measuring element 12 moves upward along the guide rail 22 with the sliding element 23, and the first movable unit 1 and the second movable unit 2 generate relative displacement.
[0035] In this embodiment, the measuring element 12 includes a grating connecting rod 121, a grating ruler (not shown) disposed on the grating connecting rod 121, a grating connecting rod fixing ring 123 connected to the indenter assembly 11, and a grating reading head 124. The lower end of the grating connecting rod 121 is fixedly assembled with the grating connecting rod fixing ring 123, and the grating connecting rod fixing ring 123 is fixedly assembled with the indenter assembly 11. The grating connecting rod 121 extends vertically upward, and its upper end is assembled and connected with the sliding member 23. The grating reading head 124 is assembled and connected with the inner frame 51 of the indenter. Of course, in other embodiments, the measuring element 12 can also be a magnetostrictive displacement sensor, a laser displacement sensor, an LVDT displacement sensor, etc., and there is no specific limitation.
[0036] The drive unit 3 includes a motor 31, a lead screw 32 connected to the output shaft of the motor 31, and an adapter 33 connected to the lead screw 32. The adapter 33 is connected to the movable arm 21. More specifically, the movable arm 21 is connected to the adapter 33, which is connected to the lead screw 32 via its internal thread. The motor 31 is connected to the lead screw 32 via a coupling 34, and the motor 31 is also connected to a motor bearing housing 36, which is assembled with the lead screw 32 via a bearing 35.
[0037] The pressure head assembly 11 includes a pressure head 111 and a pressure head connector 112. The pressure head connector 112 is assembled and connected to the grating connecting rod fixing ring 123 and is fixedly assembled to the pressure sensor 4. The pressure sensor 4 is an existing SBT630 type pressure sensor, which is fixedly assembled to the movable arm 21 through a pressure sensor adapter 41. The pressure sensor 4, movable arm 21, lead screw 32, and pressure head assembly 11 are arranged concentrically and coaxially.
[0038] The working process of this utility model is as follows: During the test, under no-load conditions, the output shaft of the motor 31 rotates, which drives the lead screw 32 to rotate together through the coupling 34. The adapter 33 moves downward linearly under the rotation of the lead screw 32, thereby generating a downward force. The adapter 33 drives the first movable unit 1 and the second movable unit 2 to move downward synchronously. That is, the adapter 33 drives the movable arm 21, pressure sensor 4, pressure sensor adapter 41, pressure head 111 and pressure head connector 112 of the pressure head assembly 11, grating connecting rod 121, grating connecting rod fixing ring 123, sliding member 23, and guide rail 22 to move downward together without relative displacement.
[0039] When the pressure head 111 moves downward and touches the test sample, the pressure head 111, the pressure head connector 112, and the grating connecting rod 121 rigidly connected to it are subjected to an upward reaction force. The pressure head connector 112 of the pressure head assembly 11 and the pressure sensor 4 are deformed due to the force. The pressure sensor 4 undergoes a large deformation. As the adapter 33 drives the above-mentioned movable arm 21, pressure sensor 4, pressure sensor adapter 41, pressure head 111 and pressure head connector 112 of the pressure head assembly 11, grating connecting rod 121, grating connecting rod fixing ring 123, sliding member 23, and guide rail 22 to continue to move downward, it attempts to increase the load. At this time, the pressure sensor 4, which is elastic, is subjected to an increasing force, and its elastic deformation is also increasing.
[0040] It should be noted that the grating connecting rod fixing ring 123, grating connecting rod 121, and sliding member 23 are not affected by the loading force during the loading process, so they will not deform. The pressure sensor 4 and pressure sensor adapter 41 both have elastic deformation under stress, with the pressure sensor 4 exhibiting larger elastic deformation.
[0041] The adapter 33, movable arm 21, guide rail 22, pressure sensor adapter 41, and pressure sensor 4 will continue to move downwards, and the amount of downward movement is defined as D. AThe pressure head connector 112, pressure head 111, grating rod fixing ring 123, grating rod 121, and sliding member 23 are hindered by the reaction force of the test sample, and their downward movement is less than that of the aforementioned adapter 33, movable arm 21, guide rail 22, pressure sensor adapter 41, and pressure sensor 4. That is, relative displacement occurs between the pressure head connector 112, pressure head 111, grating rod fixing ring 123, grating rod 121, and sliding member 23 and the adapter 33, movable arm 21, guide rail 22, pressure sensor adapter 41, and pressure sensor 4. The displacement of the pressure head connector 112, pressure head 111, grating rod fixing ring 123, grating rod 121, and sliding member 23 is the actual indentation depth of the test sample, defined as h. true The displacement generated by the adapter 33, movable arm 21, guide rail 22, pressure sensor adapter 41, and pressure sensor 4 is the deformation of pressure sensor 4 (defined as δ). sensor ) and the indentation depth h of the test sample true The sum, i.e. D A =δ sensor +h true Since the grating reading head 124 measures the displacement of the grating link 121, the measured displacement result only includes the pressure depth h of the test sample. true The indenter avoids the influence of the loading force on the measurement, that is, it effectively eliminates the influence of the indentation depth of the test sample mainly caused by the deformation of the pressure sensor 4.
[0042] The above specific embodiments are used to explain and illustrate the present utility model, and are not intended to limit the present utility model. Any modifications and changes made to the present utility model within the spirit and scope of the claims shall fall within the protection scope of the present utility model.
Claims
1. An indenter, characterized in that include: Drive unit (3); The first active unit (1) includes at least a pressure head assembly (11) and a measuring element (12) that is at least partially rigidly connected to the pressure head assembly (11). The second active unit (2) includes at least a pressure sensor (4). Part of the structure of the second active unit (2) is fixedly connected to the pressure head assembly (11) through the pressure sensor (4), and part of the structure of the second active unit (2) is movably connected to the measuring element (12). Before the pressure head assembly (11) contacts the object to be tested, the driving unit (3) drives the first active unit (1) and the second active unit (2) to move synchronously. After the pressure head assembly (11) contacts the object to be tested, the first active unit (1) and the second active unit (2) generate relative displacement under the drive of the drive unit (3), and the measuring element (12) is used to obtain the indentation depth of the pressure head assembly (11) relative to the object to be tested.
2. The indentation apparatus according to claim 1, characterized in that: The second active unit (2) includes at least an active arm (21) connected to the drive unit (3), a guide rail (22) provided on the active arm (21), and a sliding member (23) movably connected to the guide rail (22). The active arm (21) is connected to the pressure sensor (4), and the sliding member (23) is connected to the measuring member (12). Before the pressure head assembly (11) contacts the object to be tested, the drive unit (3) drives the movable arm (21) to translate, and the first movable unit (1) and the second movable unit (2) translate synchronously; After the pressure head assembly (11) contacts the object to be measured, the driving unit (3) drives the movable arm (21) to continue to translate, and the measuring component (12) translates along the guide rail (22) with the sliding component (23), and the first movable unit (1) and the second movable unit (2) generate relative displacement.
3. The indenter according to claim 1, characterized in that: The measuring component (12) includes a grating link (121), a grating ruler disposed on the grating link (121), a grating link fixing ring (123) connected to the pressure head assembly (11), and a grating reading head (124).
4. The indenter according to claim 2, characterized in that: The drive unit (3) includes a motor (31), a lead screw (32) connected to the output shaft of the motor (31), and an adapter (33) connected to the lead screw (32), which is connected to the movable arm (21).
5. The indenter according to claim 4, characterized in that: The pressure sensor (4), movable arm (21), lead screw (32), and pressure head assembly (11) are arranged concentrically and coaxially.
6. The indentation apparatus according to claim 2, characterized in that: The guide rail (22) extends vertically on the outer side of the movable arm (21).