Friction force measuring device for granular mixtures

Abstract

The invention relates to a granular mixture friction force measuring device. Comprising a base, a containing cylinder is used for containing to-be-detected granular mixtures, the containing cylinder is detachably installed on the base, and the axis of the containing cylinder is vertically arranged; the experiment arm is L-shaped, the lower end of the experiment arm is fixed on the base, the horizontal section of the upper end of the experiment arm extends above the accommodating cylinder, and the horizontal section is provided with a mounting hole with a vertical axis; the extrusion mechanism is mounted on the horizontal section and comprises a telescopic rod, the telescopic rod coaxially penetrates through the mounting hole and extends downwards, and a mounting sleeve with an opening in the lower end is arranged at the lower end of the telescopic rod; the rotating mechanism comprises a gear motor, the gear motor is mounted in a lower end opening of the mounting sleeve, an output shaft of the gear motor extends downwards and is connected with a torque sensor, and the lower end of the torque sensor is connected with a first connector; the friction disc is located over the containing cylinder and comprises a disc body, a friction layer is arranged on the lower portion of the disc body, a second connector is arranged in the center of the upper portion of the disc body, and a rotation stopping matching structure matched with the first connector in an inserted mode is arranged between the first connector and the second connector.

Description

Technical Field

[0001] This invention relates to a device for measuring the frictional force of granular materials. Background Technology

[0002] The measurement of friction between granular materials (internal friction) and friction between granular materials and containers (wall friction) is a core foundational task in granular mechanics. Its significance extends across multiple fields, including engineering design, production process optimization, equipment development, and safety control, directly determining the feasibility, economy, and safety of related technical solutions. Taking grain as an example, to achieve discrete element method (DEM) simulation analysis of wheat seed particles, it is necessary to understand the static and dynamic friction coefficients between wheat grains. Similarly, for the design of grain conveying equipment, such as conveyors and vibrating screens, it is also necessary to understand the friction coefficient between the grain and the equipment surface. Summary of the Invention

[0003] Based on this, the present invention provides a granular friction force measuring device, which can measure the friction force and friction coefficient between different types of granular materials, as well as between dissimilar types of granular materials, and also between granular materials and contact materials.

[0004] The technical solution of the present invention is as follows: The granular friction force measuring device includes: Base; The container is used to hold the particulate matter to be tested. The container can be detachably installed on the base, and the axis of the container is set vertically. The experimental arm is L-shaped, with its lower end fixed to the base and its upper horizontal section extending above the receiving cylinder. The horizontal section has a mounting hole with a vertically aligned axis. The extrusion mechanism, installed on the horizontal section, includes a telescopic rod that extends downward coaxially through a mounting hole, and the lower end of the telescopic rod has a mounting sleeve with a lower end opening. The rotating mechanism includes a geared motor, which is installed in the lower opening of the mounting sleeve. The output shaft of the geared motor extends downward and is connected to a torque sensor. The lower end of the torque sensor is connected to a first connector. The friction disc, located directly above the receiving cylinder, includes a disc body, a friction layer at the bottom of the disc body, and a second connector at the center of the upper part of the disc body. The first and second connectors are provided with an anti-rotation fit structure that is mutually inserted and engaged.

[0005] Based on the above scheme, further improvements are made as follows: the anti-rotation fit structure includes a non-rotating convex post and a groove.

[0006] Based on the above solution, the following improvements are made: a permanent magnet portion is provided on the first connector and / or the second connector so that the two are attracted to each other by magnetic force.

[0007] Based on the above solution, the following improvements are made: the first connector includes a mounting plate and the protrusion located in the middle of the mounting plate, and the permanent magnets are evenly distributed on the lower surface of the mounting plate.

[0008] Based on the above scheme, the following improvements are made: the friction layer is formed by bonding granular materials together with a colloid.

[0009] Based on the above scheme, the following improvements are made: the granules used in the friction layer are of different or the same type as the granules to be tested in the container.

[0010] Based on the above scheme, the following improvements are made: the friction layer is a corrugated steel plate, a concrete plate, or a polypropylene plate.

[0011] Based on the above scheme, the following improvements are made: a frustum is provided on the base, the outer diameter of the frustum is the same as the inner diameter of the receiving cylinder, the receiving cylinder is a cylindrical structure with both ends through, and the receiving cylinder and the frustum are provided with corresponding threaded holes, and the two are detachably connected by fastening bolts.

[0012] Based on the above scheme, the following improvements are made: a pressure sensor is connected in series on the telescopic rod of the extrusion mechanism.

[0013] Based on the above scheme, the following improvements are made: the cross-sections of both the protruding column and the groove are cross-shaped.

[0014] The beneficial effects of this application are as follows: When using the granular friction force measuring device, a container is installed on a base, and an appropriate amount of the granular material to be measured, such as corn kernels, is added to the container. When it is necessary to measure the friction force between the same type of granular material, a friction disc with a friction layer made of corn kernels is used. The second connector of the friction disc is connected to the first connector at the lower end of the torque sensor through an anti-rotation fit structure. The extrusion mechanism is activated, and the telescopic rod extends, driving the rotating mechanism and the friction disc into the container, bringing the friction layer into contact with the granular material to be measured. After applying a set pressure, the extrusion mechanism is closed, and then the rotating mechanism is activated. Its reduction motor starts, driving the torque sensor to rotate, which in turn drives the first connector to rotate. The first connector, through the anti-rotation fit structure, drives the second connector to rotate, which in turn drives the friction disc to rotate. During this process, the torque sensor reading is recorded in real time. The reduction motor starts at an extremely low speed to facilitate the measurement of the maximum static friction force. When the reduction motor just starts and the friction disc has not yet rotated, the torque... The sensor's torque value increases linearly. When it reaches its maximum point, the interlocking between particles is suddenly disrupted, and the friction disc begins to slide. This maximum point corresponds to the maximum static friction force, from which the static friction coefficient can be calculated. Then, once the speed of the reduction motor becomes constant, the torque sensor reading remains constant, corresponding to the dynamic friction force. The dynamic friction coefficient can then be calculated. This completes the measurement of static and dynamic friction forces between the same type of granular material. By changing the type of granular material in the container and on the friction layer, the friction force between various different granular materials can be measured. By changing the friction layer to materials such as steel plates, concrete slabs, or polypropylene plates, the friction force between the granular material and the contact materials of the container or other equipment can be measured. When measuring the friction force at different depths of the granular material, since different depths correspond to different pressures, the extrusion pressure of the extrusion mechanism can be changed to simulate the measurement of friction forces at different depths. Therefore, the granular friction force measuring device of this application is not only simple in structure and convenient and quick to operate, but also has a huge measuring capacity. It can measure the dynamic and static friction force of the same type of granular material, different granular materials, granular materials in contact with other materials, and the above scenarios under different depth conditions and pressures, and calculate the corresponding friction coefficient. It has a very powerful function and strong applicability. Attached Figure Description

[0015] Figure 1 This is a front view of the internal structure of a specific embodiment of the particle friction force measuring device of the present invention; Figure 2 This is a bottom view of the first connector; Figure 3 This is a top view of the second connector; Figure 4 This is a cross-sectional view of the friction disk; In the figure: 1-base, 11-frustum, 2-receiving cylinder, 21-fastening bolt, 3-experimental arm, 31-horizontal section, 311-mounting hole, 4-compression mechanism, 41-telescopic rod, 42-mounting sleeve, 5-rotation mechanism, 51-gear motor, 52-torque sensor, 53-first connector, 531-protrusion, 532-permanent magnet part, 6-friction disc, 61-disc body, 62-friction layer, 63-second connector, 631-groove, 7-granular material. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0018] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0020] A specific embodiment of the granular friction force measuring device of the present invention is as follows: Figure 1-4 As shown, the granular friction force measuring device includes a base 1, a container 2, an experimental arm 3, a squeezing mechanism 4, a rotating mechanism 5, and a friction disk 6.

[0021] The base 1 is a rectangular steel platform with a frustum 11 on its upper part and an L-shaped test arm on its left side. The outer diameter of the frustum 11 is the same as the inner diameter of the receiving cylinder 2. The receiving cylinder 2 is a cylindrical structure with both ends extending through it. The receiving cylinder 2 and the frustum 11 have corresponding threaded holes at their fitting points, and the two are detachably connected by fastening bolts 21. The receiving cylinder 2 is used to contain the granular material to be tested. The receiving cylinder 2 is detachably mounted on the base 1, and its axis is vertically oriented.

[0022] The experimental arm 3 is L-shaped and made of steel. It has stiffening plates at the corners and is fixed to the base 1 at the lower end. The horizontal section 31 at the upper end extends to the top of the receiving cylinder 2. The horizontal section 31 has a vertically oriented mounting hole 311.

[0023] The extrusion mechanism 4 is mounted on the horizontal section 31 and includes a telescopic rod 41. The telescopic rod 41 extends downward coaxially through the mounting hole 311, and its lower end has a mounting sleeve 42 with an opening at the bottom. The extrusion mechanism 4 can be an electric push rod. A pressure sensor is connected in series with the telescopic rod 41 of the extrusion mechanism 4 to detect the actual pressure of the telescopic rod 41.

[0024] The rotating mechanism 5 includes a geared motor 51, which is installed in the lower opening of the mounting sleeve 42. The output shaft of the geared motor 51 extends downward and is connected to a torque sensor 52. The lower end of the torque sensor 52 is connected to a first connector 53.

[0025] The friction disc 6 is located directly above the receiving cylinder 2 and includes a disc body 61. A friction layer 62 is provided at the lower part of the disc body 61, and a second connector 63 is located at the center of the upper part of the disc body 61. A non-rotating anti-rotation fit structure is provided between the first connector 53 and the second connector 63, allowing them to interlock. The anti-rotation fit structure includes a non-rotating protrusion 531 and a groove 631. Both the protrusion 531 and the groove 631 have a cross-shaped cross-section. Other anti-rotation structures, such as splines, can also be used. A permanent magnet portion 532 is provided on the first connector 53, allowing the first connector 53 and the second connector 63 to be attracted to each other by magnetic force. The first connector 53 includes a mounting disc and a protrusion 531 located in the center of the mounting disc. The permanent magnet portions 532 are evenly distributed on the lower surface of the mounting disc. The friction layer 62 is formed by bonding granular material with a colloid. The granular material used in the friction layer 62 is of a different or the same type as the granular material to be tested in the receiving cylinder 2. In other embodiments, the friction layer 62 is a corrugated steel plate, a concrete plate, or a polypropylene plate.

[0026] When using the granular friction force measuring device, the receiving cylinder 2 is installed on the base 1, and an appropriate amount of the granular material to be tested, such as corn kernels, is added to the receiving cylinder 2. When it is necessary to measure the friction force between the same type of granular material, a friction disc 6, whose friction layer 62 is made of corn kernels, is used. The second connector 63 of the friction disc 6 is connected to the first connector 53 at the lower end of the torque sensor 52 through an anti-rotation fit structure. The extrusion mechanism 4 is started, and the telescopic rod 41 extends, driving the rotating mechanism 5 and the friction disc 6 to extend into the receiving cylinder 2 and make the friction layer 62 contact the granular material to be tested. After applying the set pressure, the extrusion mechanism 4 is closed, and then the rotating mechanism 5 is started. After its reduction motor 51 starts, it drives the torque sensor 52 to rotate, which in turn drives the first connector 53 to rotate. The first connector 53 drives the second connector 63 to rotate through the anti-rotation fit structure, which in turn drives the friction disc 6 to rotate. During this process, the reading of the torque sensor 52 is recorded in real time. The reduction motor 51 starts at a very low speed to facilitate the measurement of the maximum static friction force. The friction disc 6 rotates as soon as the reduction motor 51 starts. Before the friction disc 6 rotates, the torque value of the torque sensor 52 rises linearly. When it reaches its highest point, the interlocking between particles is suddenly disrupted, and the friction disc 6 begins to slide. This highest point corresponds to the maximum value of static friction, and the static friction coefficient can be calculated. After the speed range of the reduction motor 51 becomes constant, the reading of the torque sensor 52 becomes constant, and this value corresponds to the dynamic friction. The dynamic friction coefficient can be calculated. Thus, the measurement of static and dynamic friction between the same type of granules is completed. By changing the type of granules on the container cylinder 2 and the friction layer 62, the friction between various different granules can be measured. By changing the friction layer 62 to a material such as a steel plate, concrete slab, or polypropylene plate, the friction between the granules and the contact material of the container or other equipment can be measured. When it is necessary to measure the friction at different depths of the granules, since the pressure at different depths is different, the extrusion pressure of the extrusion mechanism 4 can be changed to simulate the measurement of friction at different depths. Therefore, the granular friction force measuring device of this application is not only simple in structure and convenient and quick to operate, but also has a huge measuring capacity. It can measure the dynamic and static friction force of the same type of granular material, different granular materials, granular materials in contact with other materials, and the above scenarios under different depth conditions and pressures, and calculate the corresponding friction coefficient. It has a very powerful function and strong applicability.

[0027] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A device for measuring the frictional force of granular materials, characterized in that, include: Base; The container is used to hold the particulate matter to be tested. The container can be detachably installed on the base, and the axis of the container is set vertically. The experimental arm is L-shaped, with its lower end fixed to the base and its upper horizontal section extending above the receiving cylinder. The horizontal section has a mounting hole with a vertically aligned axis. The extrusion mechanism, installed on the horizontal section, includes a telescopic rod that extends downward coaxially through a mounting hole, and the lower end of the telescopic rod has a mounting sleeve with a lower end opening. The rotating mechanism includes a geared motor, which is installed in the lower opening of the mounting sleeve. The output shaft of the geared motor extends downward and is connected to a torque sensor. The lower end of the torque sensor is connected to a first connector. The friction disc, located directly above the receiving cylinder, includes a disc body, a friction layer at the bottom of the disc body, and a second connector at the center of the upper part of the disc body. The first and second connectors are provided with an anti-rotation fit structure that is mutually inserted and engaged.

2. The granular friction force measuring device according to claim 1, characterized in that, The anti-rotation fit structure includes a non-rotating protrusion and a groove.

3. The granular friction force measuring device according to claim 2, characterized in that, The first connector and / or the second connector are provided with permanent magnets so that the two are attracted to each other by magnetic force.

4. The granular friction force measuring device according to claim 3, characterized in that, The first connector includes a mounting plate and the protrusion located in the middle of the mounting plate, and the permanent magnets are evenly distributed on the lower surface of the mounting plate.

5. The granular friction force measuring device according to claim 1, characterized in that, The friction layer is formed by bonding granular materials together with a colloid.

6. The granular friction force measuring device according to claim 5, characterized in that, The granules used in the friction layer are of a different type or the same type as the granules to be tested in the container.

7. The granular friction force measuring device according to claim 1, characterized in that, The friction layer is a corrugated steel plate, a concrete slab, or a polypropylene plate.

8. The granular friction force measuring device according to claim 1, characterized in that, The base is equipped with a frustum, the outer diameter of which is the same as the inner diameter of the receiving cylinder. The receiving cylinder is a cylindrical structure with both ends through it. The receiving cylinder and the frustum are fitted with corresponding threaded holes, and the two can be detachably connected by fastening bolts.

9. The granular friction force measuring device according to claim 1, characterized in that, A pressure sensor is connected in series on the telescopic rod of the extrusion mechanism.

10. The granular friction force measuring device according to claim 1, characterized in that, Both the protruding post and the groove have a cross-shaped cross-section.

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