Universal testing machine with levelling device
By combining the spherical balance body with the spherical groove and matching the positioning protrusion groove, automatic leveling of the concrete core sample surface is achieved, solving the problem of uneven pressure distribution in traditional testing machines, improving testing accuracy and reducing costs, and making it suitable for small and medium-sized testing institutions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 佛山市建筑工程质量检测站
- Filing Date
- 2025-06-09
- Publication Date
- 2026-06-02
AI Technical Summary
When testing concrete core samples, traditional universal testing machines suffer from uneven pressure distribution due to the uneven surface of the core samples, resulting in large deviations in test results. Existing high-end testing machines are expensive and complex to maintain, making them difficult to promote in small and medium-sized testing institutions.
The design employs a combination of a spherical balancing body at the bottom of the top mold and a spherical groove at the top of the bottom mold. By utilizing the adaptive characteristics of spherical contact, the top mold can rotate and level according to the surface shape of the core sample with multiple degrees of freedom. Combined with the geometric matching of the positioning protrusion and the groove, a purely mechanical dynamic pressure homogenization is achieved.
It improves the accuracy of concrete core sample strength testing, reduces testing costs, is suitable for small and medium-sized testing institutions, provides efficient and accurate test results, and reduces the need for manual adjustment and maintenance complexity.
Smart Images
Figure CN224317429U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of universal testing machine technology, and in particular to a universal testing machine with a leveling device. Background Technology
[0002] In the quality inspection of building engineering, the compressive strength of concrete core samples is an important indicator for assessing structural safety. When conducting pressure tests on core samples, the core sample is placed on the testing platform of a traditional universal testing machine, with the core sample positioned between the platform and the indenter. The traditional universal testing machine applies pressure directly to the core sample by driving the indenter towards the platform, thus compressing the core sample between the indenter and the platform. However, if the surface of the core sample is uneven, it will lead to uneven pressure distribution and significant deviations in the test results.
[0003] Currently, testing institutions typically pre-process concrete core samples by manually grinding or filling them with core samples. However, this method is inefficient and difficult to guarantee accuracy. In recent years, some high-end testing machines have attempted to integrate hydraulic leveling systems, but these methods are costly and complex to maintain, making them difficult to promote in small and medium-sized testing institutions. Utility Model Content
[0004] To improve the accuracy of concrete core sample strength testing and reduce testing costs, this application provides a universal testing machine with a leveling device.
[0005] This application provides a universal testing machine with a leveling device, which adopts the following technical solution:
[0006] A universal testing machine with a leveling device includes:
[0007] The testing machine body includes the pressure head and platform;
[0008] The top formwork is used to place the concrete core sample, and a balancing body is connected to the bottom. The balancing body is spherical.
[0009] The bottom mold has a cylindrical platform connected to its top. The top wall of the cylindrical platform has a spherical groove that matches the balancing body. The balancing body fits into the groove wall of the spherical groove, and there is a gap between the top wall of the bottom mold and the bottom wall of the top mold.
[0010] By adopting the above technical solution, the design of the spherical balancing body at the bottom of the top mold and the spherical groove at the top of the bottom mold utilizes the adaptive characteristics of spherical contact during the compression process. This allows the top mold to rotate and level with multiple degrees of freedom according to the surface shape of the core sample. When the pressure head presses down, the unbalanced pressure causes the balancing body to slide and rotate along the spherical groove, driving the top mold to automatically adjust its tilt angle. This ensures that the upper and lower end faces of the core sample form full-area contact with the pressure head and the top mold, reducing the possibility of local stress concentration caused by surface unevenness. This mechanical leveling structure replaces manual pretreatment and complex hydraulic systems. Through pure mechanical cooperation, it achieves dynamic pressure homogenization, ensuring testing accuracy while possessing the technical advantages of simple and reliable structure and low maintenance cost. It is especially suitable for small and medium-sized testing institutions to carry out efficient and accurate concrete strength testing, thereby improving the accuracy of concrete core sample strength testing while reducing testing costs.
[0011] Optionally, the top of the platform is provided with a positioning protrusion, and the bottom of the bottom mold is provided with a positioning groove that matches the positioning protrusion, with the positioning protrusion inserted into the positioning groove.
[0012] By adopting the above technical solution, when the operator places the bottom mold on the platform, the cylindrical platform at the top of the bottom mold can be automatically aligned with the axis of the pressure head through the geometric matching of the positioning protrusion and the positioning groove without manual adjustment. When the positioning protrusion is fully embedded in the positioning groove, the horizontal degree of freedom of the bottom mold is completely constrained, so that the cylindrical platform is always directly below the pressure head, reducing the possibility of cumulative errors caused by manual visual alignment, and providing a highly repeatable benchmark condition for concrete compressive strength testing.
[0013] Optionally, the top wall area of the bottom mold is larger than the bottom wall area of the frustum, and the frustum is located at the center of the bottom mold.
[0014] By adopting the above technical solution, the extended design of the top wall of the bottom mold forms a wide annular bearing surface, which enables the bottom of the frustum to obtain a uniformly distributed supporting reaction force, reducing the possibility of the frustum deflection or shaking during the test.
[0015] Optionally, the bottom wall of the spherical groove may have a circular groove.
[0016] By adopting the above technical solution, the circular groove can collect abrasive particles, and the slope of the spherical groove can achieve self-cleaning.
[0017] Optionally, the axis of the circular groove is collinear with the axis of the truncated cylinder.
[0018] By adopting the above technical solution, wear particles can enter the circular groove accurately and quickly, thereby improving the sliding and rotational stability of the balancing component.
[0019] Optionally, the bottom wall of the balancing component is provided with a circular groove, the axis of which is collinear with the axis of the circular groove.
[0020] By adopting the above technical solution, when the core sample is compressed, the collinear axes of the circular groove at the bottom of the balance component, the circular groove of the spherical groove, and the cylindrical platform form a self-centering transmission chain, which transforms the unbalanced torque into axial rotation with reduced radial offset, improves the stability of the sliding rotation of the balance component, and thus improves the accuracy of the test.
[0021] Optionally, the top mold is rectangular, and the top wall of the top mold has two intersecting diagonals.
[0022] By adopting the above technical solution, the two diagonals form a visual reference line. The operator can visually align the core sample axis with the intersection of the diagonals to achieve rapid centering. During the pressure process, the diagonal grooves guide the load on the core sample to extend along the extension direction of the diagonals, reducing the possibility of stress concentration causing the core sample to be eccentrically compressed.
[0023] Optionally, the top wall of the top mold is provided with a positioning ring, the center of which coincides with the intersection of the two diagonals.
[0024] By adopting the above technical solution, the positioning ring and the diagonal form a dual guarantee of "mechanical limit + visual calibration", which further improves the accuracy of core sample placement.
[0025] In summary, this application includes at least one of the following beneficial technical effects:
[0026] 1. The design of the spherical balancing body at the bottom of the top mold and the spherical groove at the top of the bottom mold utilizes the adaptive characteristics of spherical contact during the compression process. This allows the top mold to rotate and level with multiple degrees of freedom according to the surface shape of the core sample. When the pressure head presses down, the unbalanced pressure causes the balancing body to slide and rotate along the spherical groove, which drives the top mold to automatically adjust its tilt angle. This ensures that the upper and lower end faces of the core sample form full-area contact with the pressure head and the top mold, reducing the possibility of local stress concentration caused by uneven surfaces. This mechanical leveling structure replaces manual pretreatment and complex hydraulic systems. Through pure mechanical cooperation, it achieves dynamic pressure homogenization, ensuring testing accuracy while having the technical advantages of simple and reliable structure and low maintenance cost. It is especially suitable for small and medium-sized testing institutions to carry out efficient and accurate concrete strength testing, thereby improving the accuracy of concrete core sample strength testing while reducing testing costs.
[0027] 2. When the operator places the bottom mold on the platform, the cylindrical platform at the top of the bottom mold will automatically align with the axis of the pressure head through the geometric matching of the positioning protrusion and the positioning groove without manual adjustment. When the positioning protrusion is fully embedded in the positioning groove, the horizontal degree of freedom of the bottom mold is fully constrained, so that the cylindrical platform is always directly below the pressure head, reducing the possibility of cumulative error caused by manual visual alignment, and providing a highly repeatable benchmark condition for concrete compressive strength testing.
[0028] 3. The two diagonals form a visual reference line. The operator can visually align the core sample axis with the intersection of the diagonals to achieve rapid centering. During the pressure process, the diagonal grooves guide the load on the core sample to extend along the diagonal extension direction, reducing the possibility of stress concentration causing the core sample to be eccentrically compressed. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the overall structure in an embodiment of this application.
[0030] Figure 2 This is a schematic diagram showing the position of the spherical groove in an embodiment of this application.
[0031] Figure 3 This is a schematic diagram of the diagonal position in an embodiment of this application.
[0032] Explanation of reference numerals in the attached figures:
[0033] 1. Testing machine body; 11. Indenter; 12. Platform; 2. Top mold; 21. Diagonal; 22. Positioning ring; 3. Bottom mold; 4. Balance body; 41. Circular groove; 6. Cylindrical platform; 61. Spherical groove; 611. Circular groove; 7. Positioning protrusion. Detailed Implementation
[0034] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.
[0035] This application discloses a universal testing machine with a leveling device.
[0036] Reference Figure 1 and Figure 2 A universal testing machine with a leveling device includes a testing machine body 1, a top mold 2, and a bottom mold 3. The testing machine body 1 includes a pressure head 11 and a platform 12. The pressure head 11 is raised and lowered on the top of the platform 12. The top mold 2 is cuboid in shape and is used to place concrete core samples. A balance body 4 is fixedly connected to the bottom wall of the top mold 2. The balance body 4 is spherical. A cylindrical platform 6 is fixedly connected to the top wall of the bottom mold 3. The top wall of the cylindrical platform 6 has a spherical groove 61 that matches the balance body 4. The outer wall of the balance body 4 fits against the groove wall of the spherical groove 61. There is a gap between the top wall of the bottom mold 3 and the bottom wall of the top mold 2 to facilitate the sliding and rotation of the balance body 4. The top mold 2, the bottom mold 3, and the balance body are all made of high-strength materials, such as high-strength aluminum alloy or stainless steel.
[0037] When testing the core sample, the balancer is placed in the spherical groove 61, and then the core sample is placed on the top wall of the top mold 2. The pressure head 11 is driven to descend, so that the core sample is clamped between the pressure head 11 and the top mold 2. During the pressure process, the balancer 4 can freely adjust its angle in the spherical groove 61, so that the pressure is evenly distributed and the test accuracy is improved.
[0038] Reference Figure 2 and Figure 3 The top wall of the top mold 2 is provided with two intersecting diagonals 21, and the top wall of the top mold 2 is provided with a positioning ring 22. In this embodiment, the positioning ring 22 is a pictorial mark. The positioning ring 22 is set at the center of the top wall. The center of the positioning ring 22 coincides with the intersection of the two diagonals 21, which improves the placement efficiency of the core sample and thus improves the testing speed of the core sample.
[0039] Furthermore, the diagonal line 21 is imprinted on the top wall of the top mold 2, so that the diagonal line 21 is recessed on the top wall of the top mold 2. During the pressure bearing process, the groove of the diagonal line 21 guides the stress load of the core sample to extend along the extension direction of the diagonal line 21, reducing the possibility of stress concentration causing the core sample to crack.
[0040] The radius of curvature of the spherical groove 61 is the same as the radius of the sphere of the balance body 4, allowing them to fit tightly together. The depth is about nine-tenths of the height of the balance body 4, creating a gap between the top wall of the cylindrical platform 6 and the bottom wall of the top mold 2. The center of the sphere of the balance body 4 is located at the top of the bottom wall of the top mold 2, making the balance body 4 smaller than the volume of a hemisphere, thus improving the sliding and rotational stability of the balance body 4 within the spherical groove 61. A circular groove 611 is formed on the bottom wall of the spherical groove 61, with the axis of the circular groove 611 collinear with the axis of the cylindrical platform 6. A circular groove 41 is formed on the bottom wall of the balance body 4, with the axis of the circular groove 41 collinear with the axis of the circular groove 611, thus improving the leveling sensitivity.
[0041] Furthermore, the diameter of the circular groove 611 is larger than that of the circular groove 41, which facilitates the accurate and rapid entry of wear particles into the circular groove.
[0042] The bottom mold 3 and the top mold 2 are rectangular parallelepipeds. The area of the top wall of the bottom mold 3 is larger than the area of the bottom wall of the frustum, and the frustum is located at the center of the bottom mold 3.
[0043] In this example, a lubricating layer can be added to the spherical groove 61 of the bottom mold 3 to reduce the friction between the balance body 4 and the spherical groove 61 and improve the leveling sensitivity. The lubricating layer can be a solid lubricant coating or a liquid lubricant filling.
[0044] The top wall of platform 12 is fixedly connected with a positioning protrusion 7, which is in the shape of a cuboid. The bottom wall of the bottom mold 3 is provided with a positioning groove that matches the positioning protrusion 7. The positioning protrusion 7 is inserted into the positioning groove to ensure that the relative position of the bottom mold 3 and platform 12 is fixed and to avoid displacement.
[0045] The implementation principle of a universal testing machine with a leveling device in this application embodiment is as follows: First, the balance body 4 of the top mold 2 is placed into the spherical groove 61 of the bottom mold 3. Then, the core sample is placed on the top mold 2 to ensure that the core sample is in full contact with the top wall of the top mold 2. Subsequently, the top mold 2 with the core sample and the bottom mold 3 are moved to the platform 12. The bottom mold 3 is installed on the positioning protrusion 7 of the platform 12 through the positioning groove. The testing machine is started, and the pressure head 11 moves downward to apply pressure to the core sample. When the pressure head 11 applies pressure to the core sample, the balance body 4 can freely adjust its angle in the spherical groove 61 to adapt to the uneven surface of the core sample, thereby achieving automatic leveling. The pressure can be evenly distributed on the surface of the core sample, improving the accuracy and reliability of the test results.
[0046] The above are all preferred embodiments of this application. These embodiments are merely explanations of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of this application should be covered within the scope of protection of this application.
Claims
1. A universal testing machine with levelling device, characterised in that, include: The testing machine body (1) includes a pressure head (11) and a platform (12); The top mold (2) is used to place the concrete core sample, and the bottom is connected to the balance body (4), which is spherical. The bottom mold (3) is connected to a cylindrical platform (6) at the top. The top wall of the cylindrical platform (6) is provided with a spherical groove (61) that matches the balance body (4). The balance body (4) fits into the groove wall of the spherical groove (61). There is a gap between the top wall of the bottom mold (3) and the bottom wall of the top mold (2).
2. A universal testing machine with levelling device according to claim 1, characterized in that The platform (12) has a positioning protrusion (7) on the top and a positioning groove matching the positioning protrusion (7) on the bottom of the bottom mold (3). The positioning protrusion (7) is inserted into the positioning groove.
3. The universal testing machine with leveling device according to claim 1, characterized in that, The top wall area of the bottom mold (3) is larger than the bottom wall area of the frustum, and the frustum is located at the center of the bottom mold (3).
4. The universal testing machine with leveling device according to claim 1, characterized in that, The bottom wall of the spherical groove (61) has a circular groove (611).
5. A universal testing machine with a leveling device according to claim 4, characterized in that, The axis of the circular groove (611) is collinear with the axis of the cylindrical platform (6).
6. A universal testing machine with a leveling device according to claim 5, characterized in that, The bottom wall of the balancing component has a circular groove (41), and the axis of the circular groove (41) is collinear with the axis of the circular groove (611).
7. A universal testing machine with a leveling device according to claim 1, characterized in that, The top mold (2) is rectangular, and the top wall of the top mold (2) has two intersecting diagonals (21).
8. A universal testing machine with a leveling device according to claim 7, characterized in that, The top wall of the top mold (2) is provided with a positioning ring (22), and the center of the positioning ring (22) coincides with the intersection of the two diagonals (21).