A device for detecting the hardness of a firebrick blank

Abstract

The present application relates to the technical field of firebrick green strength detection, and particularly relates to a firebrick green strength detection device, a pressure measuring head is inserted into the bottom end of a cylinder frame, a movable frame is slidably connected with a plug rod at the bottom end, the bottom end of the plug rod is fixedly connected with a pre-pressing ring, a connecting piece is arranged at the upper end of the pre-pressing ring, a groove seat is arranged at the bottom end of the movable frame, a second pressure sensor is arranged in the groove seat, and the upper end of the connecting piece is in contact with the second pressure sensor. The pre-pressing ring is first in contact with the surface of the firebrick green, and the annular end face of the pre-pressing ring uniformly acts on the surrounding area of the test point, so that the loose and fragile firebrick green surface particles are smoothly pre-compacted, the local stress concentration and particle dispersion phenomenon caused by the loose structure of the material surface are effectively eliminated, the influence of the test point and the surrounding loose material is isolated, the data fluctuation caused by the edge effect and the initial cracking is avoided, and the detection accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of refractory brick blank hardness testing technology, and in particular to a refractory brick blank hardness testing device. Background Technology

[0002] The main purpose of hardness testing is to evaluate the mechanical properties and resistance to external damage of refractory bricks, thereby determining whether they meet the requirements for production and use. At the same time, hardness is one of the important indicators of refractory brick performance, reflecting the compressive strength, abrasion resistance and other mechanical properties of refractory bricks, which directly affect the service life and stability of refractory bricks.

[0003] The existing process for testing the hardness of refractory brick blanks involves pressing an indenter of a specific shape and material into the surface of the blank with a constant force, measuring the depth of indentation or the force required to maintain that depth. However, the contact between the indenter and the refractory brick blank is an impact-type contact. Since the refractory brick blank remains porous and loose after drying, the bonding force between its surface particles is weak and its mechanical continuity is poor. When the indenter directly contacts the surface of the blank, an impact-type contact state is formed. This contact method easily induces the propagation of microcracks, local particle peeling, or surface fragmentation around the indentation, especially forming obvious chipping and collapse at the edge of the indentation, fundamentally interfering with the accuracy of hardness measurement and thus reducing the precision of the test. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as inducing microcrack propagation, local particle peeling, or surface fragmentation around the indentation, especially forming obvious chipping and collapse at the edge of the indentation, which fundamentally interferes with the accuracy of hardness measurement and thus reduces the precision of detection. Therefore, this invention proposes a hardness testing device for refractory brick blanks.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A device for testing the hardness of refractory brick blanks is designed, comprising a base frame, a sliding frame at the upper end of the base frame, a movable frame slidably connected to the sliding frame, a cylindrical frame slidably connected inside the movable frame, a pressure measuring head inserted into the bottom end of the cylindrical frame, a first pressure sensor for detecting pressure between the cylindrical frame and the pressure measuring head, an insertion rod slidably connected to the bottom end of the movable frame, a pre-compression ring fixedly connected to the bottom end of the insertion rod, a connector at the upper end of the pre-compression ring, a groove seat installed at the bottom end of the movable frame, a second pressure sensor disposed within the groove seat, and the upper end of the connector contacting the second pressure sensor.

[0007] Preferably, the upper end of the base frame is provided with a limiting mechanism for fixing the refractory brick blank. The limiting mechanism includes a movable platform, which is slidably connected to the base frame. The base frame is provided with a telescopic cylinder for driving the movable platform to move horizontally.

[0008] Preferably, mounting plates are provided on both sides of the upper end of the movable platform, and a compression cylinder is installed on one side of each of the two mounting plates, and a clamping plate is installed on the telescopic end of each compression cylinder.

[0009] Preferably, a collection box is inserted into the base frame, and the collection box is located below the movable platform.

[0010] Preferably, it further includes an air curtain mechanism for preventing dust and debris from accumulating on the inner wall of the pre-compression ring. The air curtain mechanism includes a micro air pump, which is fixedly connected to the slide frame. The air outlet of the micro air pump is connected to a first metal pipe, one end of which is connected to a flexible hose. A chamber is formed inside the pre-compression ring. A plurality of micro air holes are evenly spaced along the axial direction on the inner wall of the pre-compression ring. Each micro air hole is connected to the chamber. A connector is connected to the upper end of the chamber. The connector is connected to the flexible hose. A fixing plate is provided at the upper end of the pre-compression ring for fixing the flexible hose close to the pre-compression ring.

[0011] Preferably, a connecting plate is fixedly connected to the slide rail frame, and two clamping wheels are provided on the connecting plate, through which the flexible hose passes.

[0012] Preferably, a movable seat is slidably connected to the connecting plate, a wire fixing sleeve is provided on the movable seat, the wire fixing sleeve is fixedly connected to the flexible hose, and a spring is installed at the upper end of the movable seat, one end of the spring is fixedly connected to the slide rail frame.

[0013] Preferably, the air inlet of the micro air pump is connected to a second metal tube, one end of which is connected to a hollow shell, and a plurality of filter screens are evenly distributed on the hollow shell along the axis.

[0014] Preferably, it further includes a pressure equalization mechanism, which includes a circular ring plate fixedly connected to the chamber. The circular ring plate divides the chamber into a first buffer chamber and a second buffer chamber. A plurality of first exhaust pipes are evenly spaced along the axial direction on the circular ring plate. A hollow ring is provided in the first buffer chamber. The upper end of the hollow ring is connected to a connector. A plurality of second exhaust pipes are evenly spaced along the tangential direction on the outer wall of the hollow ring.

[0015] Preferably, the connector is equipped with a pressure reducing valve.

[0016] The present invention provides a refractory brick blank hardness testing device, which has the following advantages:

[0017] The pre-compression ring first contacts the surface of the refractory brick blank, and its annular end face acts evenly on the surrounding area of ​​the test point, thereby steadily pre-compacting the particles on the surface of the loose and fragile refractory brick blank. This effectively eliminates the local stress concentration and particle dispersion caused by the loose structure of the material surface, isolates the test point from the influence of the surrounding loose material, avoids data fluctuations caused by edge effects and initial cracking, and improves the accuracy of the test. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a refractory brick blank hardness testing device proposed in this invention. Figure 1 ;

[0019] Figure 2 This is a schematic diagram of the structure of a refractory brick blank hardness testing device proposed in this invention. Figure 2 ;

[0020] Figure 3 for Figure 2 A magnified structural diagram of part A above;

[0021] Figure 4 This is a schematic diagram of the connection between the slide frame and the air curtain mechanism in the refractory brick blank hardness testing device proposed in this invention;

[0022] Figure 5 This is a schematic diagram of the connection between the pre-compression ring and the pressure equalization mechanism in a refractory brick blank hardness testing device proposed in this invention;

[0023] Figure 6 This is a cross-sectional view of the connection between the pre-compression ring and the pressure equalization mechanism in a refractory brick blank hardness testing device proposed in this invention.

[0024] Figure 7 For the present invention Figure 6 A magnified schematic diagram of the structure at point B above.

[0025] In the diagram: 1. Base frame; 2. Slide rail frame; 3. Movable frame; 4. Lifting platform; 5. Limiting mechanism; 6. Cylindrical frame; 7. Electric telescopic rod; 8. Displacement sensor; 9. Pressure measuring head; 10. First pressure sensor; 11. Insert rod; 12. Preload ring; 13. Connecting piece; 14. Groove seat; 15. Second pressure sensor; 16. Bolt limiting piece; 17. Air curtain mechanism; 18. Pressure equalization mechanism; 51. Movable platform; 52. Telescopic cylinder; 53. Mounting plate; 54. Extrusion cylinder; 55. Clamping plate; 56. Collection box; 171. Miniature air pump; 172. First metal tube; 173. Hose; 174. Chamber; 175. Micro-vent; 176. Connector; 177. Wire fixing plate; 178. Connecting plate; 179. Wire clamping wheel; 1710. Second metal tube; 1711. Hollow shell; 1712. Filter screen; 1713. Movable seat; 1714. Wire fixing sleeve; 1715. Spring; 181. Circular plate; 182. First buffer chamber; 183. Second buffer chamber; 184. First exhaust pipe; 185. Hollow circular ring; 186. Second exhaust pipe; 187. Pressure reducing and constant pressure valve. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0027] Example 1: Refer to Figures 1-3 A refractory brick blank hardness testing device includes a base frame 1, a sliding frame 2 at the upper end of the base frame 1, a movable frame 3 slidably connected to the sliding frame 2, a lifting mechanism 4 on the sliding frame 2 for moving the movable frame 3 vertically, a cylindrical frame 6 slidably connected inside the movable frame 3, an electric telescopic rod 7 at the upper end of the movable frame 3 for moving the cylindrical frame 6 vertically, a displacement sensor 8 on the cylindrical frame 6 for detecting the moving distance, a pressure measuring head 9 inserted into the bottom end of the cylindrical frame 6, and a space between the cylindrical frame 6 and the pressure measuring head 9. A first pressure sensor 10 is used to detect pressure. A rod 11 is slidably connected to the bottom end of the movable frame 3. A pre-pressure ring 12 is fixedly connected to the bottom end of the rod 11. The pressure measuring head 9 passes through the pressure measuring head 9 during movement. A connector 13 is provided at the upper end of the pre-pressure ring 12. A groove seat 14 is installed at the bottom end of the movable frame 3. A bolt limiting member 16 is provided on the groove seat 14 to prevent the connector 13 from falling downward. A second pressure sensor 15 is provided in the groove seat 14. The upper end of the connector 13 is in contact with the second pressure sensor 15.

[0028] Reference Figures 1-2The upper end of the base frame 1 is provided with a limiting mechanism 5 for fixing the refractory brick blank. The limiting mechanism 5 includes a movable platform 51, which is slidably connected to the base frame 1. The base frame 1 is provided with a telescopic cylinder 52 for driving the movable platform 51 to move horizontally. The upper ends of the movable platform 51 are provided with mounting plates 53 on both sides. Each mounting plate 53 is equipped with a compression cylinder 54 on one side opposite to the other. Each compression cylinder 54 is equipped with a clamping plate 55 at its telescopic end. A collection box 56 is inserted into the base frame 1 and is located below the movable platform 51.

[0029] Working principle:

[0030] During testing, the refractory brick blank is placed on the upper end of the movable table 51. After the two extrusion cylinders 54 are started, they drive the clamping plates 55 to move, so that the two clamping plates 55 move towards each other. After the two clamping plates 55 move towards each other for a certain distance, they contact the refractory brick blank and clamp and fix it. After the telescopic cylinder 52 is started, it drives the movable table 51 to move. The movable table 51 drives the refractory brick blank to move, so that the refractory brick blank moves to the lower part of the pre-compression ring 12. The position of the refractory brick blank is changed as needed, thereby changing the testing position of the upper end of the refractory brick blank.

[0031] After the elevator 4 starts, it drives the movable frame 3 to move downward. The movable frame 3 drives the groove seat 14 to move downward. The groove seat 14 drives the pre-compression ring 12 to move through the connector 13. After the pre-compression ring 12 moves downward a certain distance, it contacts the upper end of the refractory brick blank. After the pre-compression ring 12 continues to move downward, it squeezes the upper end of the refractory brick blank. The reaction force generated by the squeezing pushes the connector 13 upward. After the connector 13 moves upward, it squeezes the second pressure sensor 15. When the pressure value detected by the second pressure sensor 15 reaches the set value, the elevator 4 stops driving the movable frame 3 to move downward. At this time, the pre-compression ring 12 is in a squeezing state with the outer side of the detection area at the upper end of the refractory brick blank, compacting the outer side of the detection area at the upper end of the refractory brick blank.

[0032] After the electric telescopic rod 7 is started, it drives the cylindrical frame 6 to move downward. Under the guidance of the movable frame 3, the cylindrical frame 6 moves smoothly. The cylindrical frame 6 drives the pressure measuring head 9 to move. The pressure measuring head 9 moves downward a certain distance, passes through the pre-compression ring 12, and contacts the upper end of the refractory brick blank. At this time, the displacement sensor 8 starts to detect the downward movement distance of the pressure measuring head 9. After the pressure measuring head 9 continues to move downward, it squeezes the refractory brick blank. The reaction force generated by the squeezing pushes the pressure measuring head 9 upward. The pressure measuring head 9 squeezes the first pressure sensor 10 upward. When the pressure value detected by the first pressure sensor 10 reaches the set value, the electric telescopic rod 7 stops driving the cylindrical frame 6 to move downward. After the pressure measuring head 9 squeezes the refractory brick blank for a set time, the electric telescopic rod 7 drives the cylindrical frame 6 to move upward and reset. The hardness of the refractory brick blank is obtained according to the data detected by the displacement sensor 8 and the first pressure sensor 10.

[0033] When testing the hardness of refractory brick blanks, the pre-compression ring 12 first contacts the surface of the refractory brick blank, and its annular end face acts evenly on the area around the test point, thereby smoothly pre-compacting the loose and fragile surface particles of the refractory brick blank. A dense annular support base is formed around the test point, which effectively eliminates the local stress concentration and particle dispersion caused by the loose structure of the material surface. The pressure head 9 then passes through the central guide hole of the pre-compression ring 12 and vertically reaches and acts on the pre-compressed measurement area. Since the surface of the measurement area has been pre-compressed, the pressure head 9 isolates the test point from the influence of the surrounding loose material during the contact and pressing process, avoiding data fluctuations caused by edge effects and initial cracking, and improving the accuracy of the test.

[0034] Example 2: During the testing process, the pressure probe 9 passes through the pre-compression ring 12 and contacts the upper end of the refractory brick blank. Dust on the upper end of the refractory brick blank easily accumulates on the inner ring wall of the pre-compression ring 12, thereby increasing the resistance to movement of the pressure probe 9 or causing it to jam. (Refer to...) Figures 4-6 As another preferred embodiment of the present invention, based on embodiment 1, it further includes an air curtain mechanism 17 for preventing dust and debris from accumulating on the inner ring wall of the pre-compression ring 12. The air curtain mechanism 17 includes a micro air pump 171, which is fixedly connected to the slide frame 2. The outlet of the micro air pump 171 is connected to a first metal pipe 172, and one end of the first metal pipe 172 is connected to a flexible hose 173. A chamber 174 is formed inside the pre-compression ring 12. A plurality of micro air holes 175 are evenly spaced along the axial direction on the inner ring wall of the pre-compression ring 12. Each micro air hole 175 is connected to the chamber 174. The upper end of the chamber 174 is connected to a connector 176, which is connected to the flexible hose 173. The upper end of the pre-compression ring 12 is provided with a means for controlling the accumulation of dust and debris near the pre-compression ring. The hose 173 of ring 12 is fixed to a wire fixing plate 177. A connecting plate 178 is fixedly connected to the slide frame 2. The connecting plate 178 is provided with two wire clamping wheels 179. The hose 173 passes through the two wire clamping wheels 179. A movable seat 1713 is slidably connected to the connecting plate 178. A wire fixing sleeve 1714 is provided on the movable seat 1713. The wire fixing sleeve 1714 is fixedly connected to the hose 173. A spring 1715 is installed at the upper end of the movable seat 1713. One end of the spring 1715 is fixedly connected to the slide frame 2. The air inlet of the micro air pump 171 is connected to a second metal pipe 1710. One end of the second metal pipe 1710 is connected to a hollow shell 1711. Several filter screens 1712 are evenly distributed on the hollow shell 1711 along the axis.

[0035] Working principle:

[0036] During the vertical movement of the pressure measuring head 9, the micro air pump 171 is powered on and started, allowing air to pass through the filter screen 1712 and enter the hollow shell 1711. The filter screen 1712 filters the air entering the hollow shell 1711 to prevent dust and debris from entering. The air in the hollow shell 1711 passes through the second metal tube 1710 and then enters the first metal tube 172. The air in the first metal tube 172 is introduced into the flexible tube 173. The air in the flexible tube 173 passes through the connector 176 and then enters the chamber 174. The air in the chamber 174 is released from several micro air holes 175. The air released from the several micro air holes 175 forms an air curtain on the inner ring wall of the pre-pressure ring 12, protecting the inner ring wall of the pre-pressure ring 12 and preventing dust from accumulating on the inner ring wall. This ensures that the pressure measuring head 9 can pass through the pre-pressure ring 12 smoothly and that the movement of the pressure measuring head 9 is unobstructed.

[0037] When the pre-compression ring 12 moves downward, it drives the wire fixing plate 177 to move. The wire fixing plate 177 drives the bottom of the hose 173 to move, so that the connection between the hose 173 and the connector 176 will not be pulled, thus not affecting the pressure detection of the second pressure sensor 15. After the pre-compression ring 12 moves downward a certain distance, the wire fixing plate 177 pulls the hose 173 downward, so that the upper part of the hose 173 passes between the two clamping wheels 179. The hose between the wire fixing plate 177 and the clamping wheels 179 is in a straight state, avoiding bending of the hose between the wire fixing plate 177 and the clamping wheels 179, so that it will not contact the upper end of the refractory brick blank under its own weight.

[0038] After the upper part of the flexible hose 173 moves downward a certain distance, it pulls the fixed wire sleeve 1714. The fixed wire sleeve 1714 pulls the movable seat 1713 downward. After the movable seat 1713 moves downward, it pulls the spring 1715. The spring 1715 generates elastic force after being pulled. When the pre-compression ring 12 moves upward to reset at the end of the test, the elastic force generated by the spring 1715 drives the movable seat 1713 to move upward to reset. When the movable seat 1713 moves upward to reset, it pulls the flexible hose 173, so that the bottom of the flexible hose 173 passes between the two clamping wheels 179, ensuring that the flexible hose 173 between the fixed wire plate 177 and the clamping wheels 179 is not too long and will bend, thus preventing it from contacting the upper end of the refractory brick blank.

[0039] Example 3: When gas is introduced into the chamber 174, it is introduced individually through the connector 176, resulting in large changes in gas pressure. This leads to uneven gas release from the numerous micro-pores 175, resulting in an uneven annular air curtain. This generates a lateral, uneven aerodynamic pressure on the pressure measuring head 9, which is easily detected and captured by the displacement sensor 8, introducing noise and reducing the accuracy of the detection. (Refer to...) Figures 5-7As another preferred embodiment of the present invention, based on embodiment 2, it further includes a pressure equalization mechanism 18. The pressure equalization mechanism 18 includes a circular ring plate 181, which is fixedly connected to the chamber 174. The circular ring plate 181 divides the chamber 174 into a first buffer chamber 182 and a second buffer chamber 183. A plurality of first exhaust pipes 184 are evenly spaced along the axial direction on the circular ring plate 181. A hollow ring 185 is provided in the first buffer chamber 182. The upper end of the hollow ring 185 is connected to a connector 176. A plurality of second exhaust pipes 186 are evenly spaced along the tangential direction on the outer wall of the hollow ring 185. A pressure reducing and constant pressure valve 187 is provided on the connector 176.

[0040] Working principle:

[0041] When gas passes through connector 176, its pressure is regulated by pressure reducing valve 187. The regulated gas is then introduced into hollow ring 185, where it is buffered before being released from several second exhaust pipes 186. This forces the airflow to rotate tangentially along the ring, forming a stable vortex. The vortex then enters the second buffer chamber 183, from which it enters the first buffer chamber 182 through several first exhaust pipes 184. Finally, the gas is released from the micro-pores 175. After pressure regulation by pressure reducing valve 187 and buffering and decelerating by hollow ring 185, the buffered gas enters the first buffer chamber 182 through several first exhaust pipes 184. This ensures that the gas released from the micro-pores 175 is uniform and does not generate uneven pneumatic pressure on the pressure measuring head 9, thus maintaining the accuracy of the detection.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for testing the hardness of refractory brick blanks, comprising a base frame (1), wherein a sliding frame (2) is provided at the upper end of the base frame (1), and a movable frame (3) is slidably connected to the sliding frame (2), characterized in that, in: A cylindrical frame (6) is slidably connected inside the movable frame (3). A pressure measuring head (9) is inserted into the bottom end of the cylindrical frame (6). A first pressure sensor (10) for detecting pressure is provided between the cylindrical frame (6) and the pressure measuring head (9). A plug rod (11) is slidably connected to the bottom end of the movable frame (3). A pre-pressure ring (12) is fixedly connected to the bottom end of the plug rod (11). A connector (13) is provided at the upper end of the pre-pressure ring (12). A groove seat (14) is installed at the bottom end of the movable frame (3). A second pressure sensor (15) is provided inside the groove seat (14). The upper end of the connector (13) is in contact with the second pressure sensor (15).

2. The refractory brick blank hardness testing device according to claim 1, characterized in that, The upper end of the base frame (1) is provided with a limiting mechanism (5) for fixing the refractory brick blank. The limiting mechanism (5) includes a movable platform (51), which is slidably connected to the base frame (1). The base frame (1) is provided with a telescopic cylinder (52) for driving the movable platform (51) to move horizontally.

3. The refractory brick blank hardness testing device according to claim 2, characterized in that, The upper sides of the movable platform (51) are provided with mounting plates (53), and each of the two mounting plates (53) is equipped with a compression cylinder (54) on the opposite side. Each compression cylinder (54) is equipped with a clamping plate (55) at its telescopic end.

4. The refractory brick blank hardness testing device according to claim 3, characterized in that, A collection box (56) is inserted into the base frame (1), and the collection box (56) is located below the movable platform (51).

5. The refractory brick blank hardness testing device according to claim 1, characterized in that, It also includes an air curtain mechanism (17) for preventing dust and debris from accumulating on the inner ring wall of the pre-compression ring (12). The air curtain mechanism (17) includes a miniature air pump (171), which is fixedly connected to the slide frame (2). The outlet of the miniature air pump (171) is connected to a first metal pipe (172), and one end of the first metal pipe (172) is connected to a flexible hose (173). A chamber (173) is formed inside the pre-compression ring (12). 4) The inner ring wall of the pre-compression ring (12) is provided with a number of micro air holes (175) at equal intervals along the axis. Each micro air hole (175) is connected to a chamber (174). The upper end of the chamber (174) is connected to a connector (176). The connector (176) is connected to a hose (173). The upper end of the pre-compression ring (12) is provided with a fixing plate (177) for fixing the hose (173) close to the pre-compression ring (12).

6. The refractory brick blank hardness testing device according to claim 5, characterized in that, A connecting plate (178) is fixedly connected to the slide frame (2), and two wire clamping wheels (179) are provided on the connecting plate (178). The hose (173) passes between the two wire clamping wheels (179).

7. The refractory brick blank hardness testing device according to claim 6, characterized in that, A movable seat (1713) is slidably connected to the connecting plate (178). A wire fixing sleeve (1714) is provided on the movable seat (1713). The wire fixing sleeve (1714) is fixedly connected to the flexible hose (173). A spring (1715) is installed at the upper end of the movable seat (1713). One end of the spring (1715) is fixedly connected to the slide frame (2).

8. The refractory brick blank hardness testing device according to claim 7, characterized in that, The air inlet of the micro air pump (171) is connected to a second metal pipe (1710), one end of the second metal pipe (1710) is connected to a hollow shell (1711), and a number of filter screens (1712) are evenly distributed on the hollow shell (1711) along the axis.

9. The refractory brick blank hardness testing device according to claim 8, characterized in that, It also includes a pressure equalization mechanism (18), which includes a ring plate (181) fixedly connected to the chamber (174). The ring plate (181) divides the chamber (174) into a first buffer chamber (182) and a second buffer chamber (183). A plurality of first exhaust pipes (184) are evenly spaced along the axis on the ring plate (181). A hollow ring (185) is provided in the first buffer chamber (182). The upper end of the hollow ring (185) is connected to a connector (176). A plurality of second exhaust pipes (186) are evenly spaced along the tangential direction on the outer wall of the hollow ring (185).

10. The refractory brick blank hardness testing device according to claim 9, characterized in that, The connector (176) is equipped with a pressure reducing valve (187).

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