Clamping device and grinding device for cement standard sample for mechanical property test

Abstract

The utility model provides a clamping device and a grinding device for a cement standard sample for mechanical property testing. The grinding device is composed of a supporting frame, a grinding assembly and the clamping device. The clamping device is composed of a clamping device, a base matched with the clamping device in a meshed mode and a transmission device. The clamping device is composed of a shell, a clamping rod and connecting rods, the clamping rod comprises clamping heads and a toothed plate, and every two adjacent clamping heads are hinged through a pair of connecting rods. The toothed plate penetrates through the shell to be meshed with a gear at one end of the transmission rod and is further connected with a gear in the base through the transmission rod. The grinding assembly is connected with a built-in power source; the grinding assembly comprises a fixing block and a grinding wheel, the grinding wheel is controlled to operate through a switch, and the grinding size is controlled through a rotary knob. And the fixed block is meshed and fixed with the support frame through the fixed gear and is driven by the transmission belt to translate. According to the grinding device, through cooperation of the clamping and fixing device and the grinding assembly, mechanical grinding of the sample is achieved on the premise that it is guaranteed that the upper face and the lower face of the sample are parallel and coaxial, and the grinding device has important practical application value.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical device technology, and relates to a clamping device and a grinding device for cement standard samples used for mechanical property testing. Background Technology

[0002] Cement is a core material in the construction industry, and its mechanical properties directly affect the strength, stability, and durability of concrete structures. Therefore, accurately assessing the mechanical properties of cement (such as compressive strength, tensile strength, and Poisson's ratio) is a crucial step in ensuring project quality. To obtain reliable mechanical property data, cement sample preparation must strictly adhere to standardized testing methods, including sample fabrication, curing, and surface treatment. However, during demolding and curing, the shrinkage of the cement material itself and unavoidable impacts often lead to uneven surfaces and cracks on the cement sample surface. These uneven surfaces severely affect the accuracy of mechanical property testing; especially in compressive and tensile tests, the smoothness of the sample surface directly affects the uniformity of applied loads and the repeatability of test data.

[0003] To address the aforementioned issues, a grinding process is commonly used to effectively remove irregular shapes, bubbles, cracks, and other defects from the surface of cement samples, ensuring a smooth and flat surface to provide a standardized testing surface. This treatment ensures the accuracy and reliability of mechanical property test results. Furthermore, the grinding process eliminates localized stress concentration effects caused by surface roughness, reducing testing errors and ensuring that test results accurately reflect the inherent properties of cement. With the increasing demands on cement performance in construction projects, the grinding process has become an indispensable step in cement sample preparation, widely used in cement quality control, standardized testing, and scientific research experiments. Therefore, grinding standard cement samples is a crucial step in cement mechanical property testing.

[0004] Currently, in practice, grinding standard cement samples is often done manually with sandpaper, which is very time-consuming and labor-intensive. Furthermore, many types of cement have significant shrinkage volumes, and the cement dust generated during grinding and smoothing can pose health risks. Most importantly, manual grinding makes it difficult to ensure the upper and lower surfaces are parallel, causing the sample to be subjected to forces not along a single axis during compressive strength testing, thus artificially influencing the calculation of mechanical parameters. Therefore, designing a small device for grinding samples is essential. However, no relevant reports have been found to date. Utility Model Content

[0005] To address the current limitations of grinding cement standard samples in existing technologies, this invention provides a grinding device for cement standard samples used in mechanical property testing. This grinding device, through the cooperation of a clamping and fixing device and a grinding assembly, achieves mechanized grinding of the sample while ensuring the parallelism and coaxiality of the upper and lower surfaces. Furthermore, it is simple to operate and allows for controllable grinding height, solving the technical problems existing in the grinding of cement standard samples in the prior art and possessing significant practical application value.

[0006] The technical solution of this utility model:

[0007] A clamping device for fixing cement standard samples, comprising a clamp, a base meshing with the clamp, and a transmission device. The clamp consists of a housing, n clamping rods, and n pairs of connecting rods. Each clamping rod includes an arc-shaped clamping head and a toothed plate fixedly connected to it. Adjacent clamping heads are hinged together by a pair of connecting rods. The transmission device includes a transmission rod assembly consisting of a transmission rod and gears at both ends of the transmission rod, an internal gear in the base, and a base knob. The internal gear in the base rotates coaxially with the base knob. The base includes a base support and a detachable fixing component that matches the support. Each toothed plate penetrates the housing and meshes with a gear at one end of the transmission rod. The gear at the end of the transmission rod away from the toothed plate meshes with the internal gear in the base. A base slot I is provided at the end of the housing away from the clamping rod, and a base slot II is provided between the clamp and the base knob. The base slot II is coaxial with the base knob. The fixing component has teeth that match the base slots I and II. The housing of the clamp is fixed to the base through the base slot I, and the clamping rod is fixed to the base through the base slot II.

[0008] Preferably, each pair of connecting rods is hinged at the end away from the clamping rod, and the hinge point is fixedly connected to the housing; n=3.

[0009] Preferably, the connecting rod is elastically connected to the clamping head via a spring.

[0010] A grinding device for cement standard samples used in mechanical property testing, comprising a support frame, a grinding assembly mounted on the support frame, and a clamping device as described above. The grinding assembly is connected to a built-in power source, which is controlled by a switch mounted on the grinding assembly. The grinding assembly includes a fixed block and a grinding wheel mounted on the fixed block. The grinding wheel is controlled by a switch, and the grinding dimension is controlled by a knob. The fixed block is fixed to the support frame via a fixed gear. A drive belt is mounted on the support frame, and the surface of the drive belt has a toothed structure that meshes with the fixed gear. The drive belt is controlled by a power source.

[0011] The beneficial effects of this utility model are:

[0012] (1) The clamping device for fixing cement standard specimens described in this application can fix the cement standard specimens in the arc-shaped slots formed by the three clamping heads, thereby ensuring that the grinding direction of the upper and lower surfaces of the cylindrical specimens is perpendicular to the axis of the cylinder; thus ensuring that the specimens are subjected to force on a plane during testing, avoiding excessive local stress caused by single-point contact, and improving the accuracy of the test results.

[0013] (2) The grinding device for cement standard specimens for mechanical property testing described in this application achieves the grinding of the surface of cement specimen standard parts by means of the cooperation of clamping device and grinding component and the automatic forward movement of grinding wheel, saving labor and time costs and having important practical application value.

[0014] (3) The clamping device for fixing cement standard samples described in this application is ingeniously designed with a hinged combination of clamping rod and connecting rod, which realizes the flexibility and adjustability of the clamping range and has a wide range of applications. Attached Figure Description

[0015] Appendix Figure 1 This is one of the structural schematic diagrams of the specimen grinding device described in Embodiment 3 of this application;

[0016] Appendix Figure 2 This is one of the structural schematic diagrams of the clamping device described in Embodiment 1 of this application;

[0017] Appendix Figure 3 This is a second schematic diagram of the clamping device described in Embodiment 1 of this application;

[0018] Appendix Figure 4 This is a schematic diagram of the transmission device in the clamping device described in Embodiment 1 of this application;

[0019] Appendix Figure 5 This is one of the partial structural schematic diagrams of the clamping device described in Embodiment 2 of this application;

[0020] Appendix Figure 6 This is a second partial structural schematic diagram of the clamping device described in Embodiment 2 of this application;

[0021] Appendix Figure 7 This is a schematic diagram of the grinding device (excluding the clamping device) described in Embodiment 3 of this application;

[0022] Appendix Figure 8 This is a schematic diagram of the transmission belt structure in the grinding device described in Embodiment 3 of this application;

[0023] Appendix Figure 9 This is one of the structural schematic diagrams of the grinding device described in Embodiment 3 of this application;

[0024] Appendix Figure 10 This is a second schematic diagram of the grinding device of the grinding apparatus described in Embodiment 3 of this application;

[0025] Among them: 1. Clamp, 2. (Clamp) housing, 3. Clamping rod, 3-1. Clamping head, 3-2. Toothed plate, 4. Connecting rod, 5. Transmission rod, 6. Internal gear of base, 7. Base slot I, 8. Base slot II, 9. Base knob, 10. Support frame, 11. (Built-in power source) switch, 12. Fixing block, 13. Grinding wheel, 14. Support seat (14), 15. Fixing component, 16. Transmission belt, 17. Fixed gear, 18. Toothed structure, 19. (Grinding wheel) knob, 20-1. Hinge shaft, 20-2. Hinge base, 21. Hinge groove. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments.

[0027] Example 1: Clamping device for fixing cement standard specimens

[0028] The clamping device consists of a clamp 1, a base that meshes with the clamp 1, and a transmission device. The clamp 1 comprises a housing 2, three clamping rods 3, and three pairs of connecting rods 4. Each clamping rod includes an arc-shaped clamping head 3-1 and a toothed plate 3-2 fixedly connected to it. Adjacent clamping heads 3-1 are hinged together by a pair of connecting rods 4. The transmission device includes a transmission rod 5, an internal gear 6 in the base, and a base knob 9. The internal gear 6 rotates coaxially with the base knob 9. The base includes a base support 14 and a detachable fixing element 15 that matches the support 14. Each toothed plate 3-2 penetrates the housing 2 and meshes with a gear at one end of the transmission rod 5; the gear at the end of the transmission rod 5 away from the toothed plate 3-2 meshes with the internal gear 6 in the base. A base slot I 7 is provided at the end of the housing 2 away from the clamping rods 3, and a base slot II 8 is provided between the clamp 1 and the base knob 9. The base slot II 8 is coaxial with the base knob 9. The fixing member 15 is provided with teeth that match the base slot I 7 and the base slot II 8. The housing 2 of the clamp 1 is fixed to the base through the base slot I 7, and the clamping rod 3 is fixed to the base through the base slot II 8.

[0029] Example 2: Example 1: Clamping device for fixing cement standard specimens

[0030] Unlike Embodiment 1, the hinge point at the end of each pair of connecting rods 4 away from the clamping rod 3 is fixedly connected to the housing 2. The connecting rod 4 is elastically connected to the clamping head 3-1 via a spring. Specifically, the hinge structure connecting the clamping head 3-1 and the connecting rod 4 consists of a hinge shaft 20-1 and a hinge base 20-2 fixedly connected to it. The clamping head 3-1 has a hinge groove 21 inside that matches the hinge base 20-2, enabling the hinge base 20-2 to reciprocate within the hinge groove 21. Simultaneously, the hinge base 20-2 is connected to the clamping head 3-1 via a spring. When the hinge base 20-2 moves away from the clamping head 3-1, the spring provides tension, causing the hinge base 20-2 to return to the end of the hinge groove 21 near the clamping head.

[0031] Example 3: Grinding device for cement standard specimens used for mechanical property testing

[0032] The grinding device consists of a support frame 10 and a grinding assembly and a clamping device mounted on the support frame 10. The grinding assembly is connected to a built-in power source 11. The grinding assembly includes a fixing block 12 and a grinding wheel 13 mounted on the fixing block 12. The grinding wheel 13 is controlled to operate by the built-in power source 11. The fixing block 12 is fixed to the support frame 10 by a fixing gear 17. A transmission belt 16 is mounted on the support frame 10. The surface of the transmission belt 16 has a toothed structure 18 that meshes with the fixing gear 17. The transmission belt 16 is controlled to operate by a power source.

[0033] The clamping device is fixedly connected to the support frame 10 via a base. The structure of the clamping device is detailed in Embodiment 1.

[0034] Example 4: Grinding device for cement standard specimens used for mechanical property testing

[0035] The grinding device consists of a support frame 10 and a grinding assembly and a clamping device mounted on the support frame 10. The grinding assembly is connected to a built-in power source 11. The grinding assembly includes a fixing block 12 and a grinding wheel 13 mounted on the fixing block 12. The grinding wheel 13 is controlled to operate by the built-in power source 11. The fixing block 12 is fixed to the support frame 10 by a fixing gear 17. A transmission belt 16 is mounted on the support frame 10. The surface of the transmission belt 16 has a toothed structure 18 that meshes with the fixing gear 17. The transmission belt 16 is controlled to operate by a power source.

[0036] The clamping device is detachably connected to the support frame 10 via a base. The structure of the clamping device is detailed in Embodiment 2.

[0037] Example 5: Operation of the grinding device

[0038] First, place the cured standard specimen into the clamp 1. Rotate the base knob 9 to cause the internal gear 6 of the coaxial base to drive the clamping rod 3 and the connected rod 4 via the transmission rod 5 to adjust the clamping size until the cement standard specimen is locked. Then, engage the base slot I 7 and base slot II 8 of the clamping device with the meshing teeth on the fixing part 15 to achieve double fixation of the housing 2 and the clamping rod 3. After the specimen is fixed, turn on the power. The rotation of the transmission belt 16 drives the grinding assembly to move horizontally until the grinding wheel 13 contacts the specimen, then turn off the power. Twist the knob 19 on the grinding assembly to adjust the length to be smoothed. Turn on the switch 11 to run the grinding wheel 13 through the built-in power source. Then turn on the power to move the grinding device forward to perform the smoothing work. After one end of the specimen is basically flat, release the specimen from the clamp 1 and repeat the above process to smooth the other end of the specimen. The grinding device significantly improves the grinding speed compared to manual grinding, and can quickly grind away more than one centimeter of cement block samples after normal mixing ratio of G-grade cement ash and curing for 48 hours within one minute.

Claims

1. A clamping device for a cement standard test specimen for mechanical property testing, characterized in that: The clamping device is composed of a clamping device (1), a base matched with the clamping device and a transmission device; the clamping device (1) is composed of a shell (2), n clamping rods (3) and n pairs of connecting rods (4), the clamping rod includes a circular arc clamping head (3-1) and a tooth plate (3-2) fixedly connected with the clamping head; the transmission device includes a transmission rod assembly composed of a transmission rod (5) and gears at both ends of the transmission rod, a base internal gear (6) and a base knob (9); the base internal gear (6) rotates coaxially with the base knob (9); the clamping heads (3-1) are hingedly connected through a pair of connecting rods (4) between adjacent clamping heads; each tooth plate (3-2) is connected with the gear at one end of the transmission rod (5) through the shell (2); the gear at the end of the transmission rod (5) away from the tooth plate (3-2) is connected with the base internal gear (6).

2. The apparatus of claim 1, wherein: The shell (2) is provided with a base clamping groove I (7) at the end away from the clamping rod (3), a base clamping groove II (8) is arranged between the clamping device (1) and the base knob (9), and the base clamping groove II (8) is coaxial with the base knob (9); the shell (2) of the clamping device (1) is fixedly connected with the base through the base clamping groove I (7), and the clamping rod (3) is fixedly connected with the base through the base clamping groove II (8).

3. The apparatus of claim 2, wherein: The hinge points of the connecting rods (4) away from the clamping rods (3) are fixedly connected with the shell (2); n=3.

4. A cement standard sample holder according to any one of claims 1-3, characterized in that: The connecting rod (4) is elastically connected with the clamping head (3-1) through a spring.

5. The apparatus of claim 4, wherein: The base includes a base support seat (14) and a detachable fixing piece (15) matched with the support seat.

6. The apparatus of claim 5, wherein: The fixing piece (15) is provided with meshing teeth matched with the base clamping groove I (7) and the base clamping groove II (8).

7. A device for grinding down a cement standard test specimen for mechanical property testing, characterised in that: The grinding device is composed of a support frame (10), a grinding assembly arranged on the support frame (10) and the clamping device according to any one of claims 1-5; the grinding device is connected with an internal power source.

8. The apparatus of claim 7, wherein: The grinding assembly includes a fixed block (12) and a grinding wheel (13) arranged on the fixed block (12), the grinding wheel (13) is controlled to operate through the internal power source; the fixed block (12) is fixedly connected with the support frame (10) through a fixed gear (17).

9. The apparatus of claim 7, wherein: The support frame (10) is provided with a transmission belt (16), the surface of the transmission belt (16) is a toothed structure (18) matched with the fixed gear (17), and the transmission belt (16) is controlled to operate through a power source.

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